· 6 years ago · Nov 01, 2019, 12:40 PM
1# WELCOME TO SQUID 4.6
2# ----------------------------
3#
4# This is the documentation for the Squid configuration file.
5# This documentation can also be found online at:
6# http://www.squid-cache.org/Doc/config/
7#
8# You may wish to look at the Squid home page and wiki for the
9# FAQ and other documentation:
10# http://www.squid-cache.org/
11# http://wiki.squid-cache.org/SquidFaq
12# http://wiki.squid-cache.org/ConfigExamples
13#
14# This documentation shows what the defaults for various directives
15# happen to be. If you don't need to change the default, you should
16# leave the line out of your squid.conf in most cases.
17#
18# In some cases "none" refers to no default setting at all,
19# while in other cases it refers to the value of the option
20# - the comments for that keyword indicate if this is the case.
21#
22
23# Configuration options can be included using the "include" directive.
24# Include takes a list of files to include. Quoting and wildcards are
25# supported.
26#
27# For example,
28#
29# include /path/to/included/file/squid.acl.config
30#
31# Includes can be nested up to a hard-coded depth of 16 levels.
32# This arbitrary restriction is to prevent recursive include references
33# from causing Squid entering an infinite loop whilst trying to load
34# configuration files.
35#
36# Values with byte units
37#
38# Squid accepts size units on some size related directives. All
39# such directives are documented with a default value displaying
40# a unit.
41#
42# Units accepted by Squid are:
43# bytes - byte
44# KB - Kilobyte (1024 bytes)
45# MB - Megabyte
46# GB - Gigabyte
47#
48# Values with spaces, quotes, and other special characters
49#
50# Squid supports directive parameters with spaces, quotes, and other
51# special characters. Surround such parameters with "double quotes". Use
52# the configuration_includes_quoted_values directive to enable or
53# disable that support.
54#
55# Squid supports reading configuration option parameters from external
56# files using the syntax:
57# parameters("/path/filename")
58# For example:
59# acl whitelist dstdomain parameters("/etc/squid/whitelist.txt")
60#
61# Conditional configuration
62#
63# If-statements can be used to make configuration directives
64# depend on conditions:
65#
66# if <CONDITION>
67# ... regular configuration directives ...
68# [else
69# ... regular configuration directives ...]
70# endif
71#
72# The else part is optional. The keywords "if", "else", and "endif"
73# must be typed on their own lines, as if they were regular
74# configuration directives.
75#
76# NOTE: An else-if condition is not supported.
77#
78# These individual conditions types are supported:
79#
80# true
81# Always evaluates to true.
82# false
83# Always evaluates to false.
84# <integer> = <integer>
85# Equality comparison of two integer numbers.
86#
87#
88# SMP-Related Macros
89#
90# The following SMP-related preprocessor macros can be used.
91#
92# ${process_name} expands to the current Squid process "name"
93# (e.g., squid1, squid2, or cache1).
94#
95# ${process_number} expands to the current Squid process
96# identifier, which is an integer number (e.g., 1, 2, 3) unique
97# across all Squid processes of the current service instance.
98#
99# ${service_name} expands into the current Squid service instance
100# name identifier which is provided by -n on the command line.
101#
102# Logformat Macros
103#
104# Logformat macros can be used in many places outside of the logformat
105# directive. In theory, all of the logformat codes can be used as %macros,
106# where they are supported. In practice, a %macro expands as a dash (-) when
107# the transaction does not yet have enough information and a value is needed.
108#
109# There is no definitive list of what tokens are available at the various
110# stages of the transaction.
111#
112# And some information may already be available to Squid but not yet
113# committed where the macro expansion code can access it (report
114# such instances!). The macro will be expanded into a single dash
115# ('-') in such cases. Not all macros have been tested.
116#
117
118# TAG: broken_vary_encoding
119# This option is not yet supported by Squid-3.
120#Default:
121# none
122
123# TAG: cache_vary
124# This option is not yet supported by Squid-3.
125#Default:
126# none
127
128# TAG: error_map
129# This option is not yet supported by Squid-3.
130#Default:
131# none
132
133# TAG: external_refresh_check
134# This option is not yet supported by Squid-3.
135#Default:
136# none
137
138# TAG: location_rewrite_program
139# This option is not yet supported by Squid-3.
140#Default:
141# none
142
143# TAG: refresh_stale_hit
144# This option is not yet supported by Squid-3.
145#Default:
146# none
147
148# TAG: cache_peer_domain
149# Replace with dstdomain ACLs and cache_peer_access.
150#Default:
151# none
152
153# TAG: ie_refresh
154# Remove this line. The behaviour enabled by this is no longer needed.
155#Default:
156# none
157
158# TAG: sslproxy_cafile
159# Remove this line. Use tls_outgoing_options cafile= instead.
160#Default:
161# none
162
163# TAG: sslproxy_capath
164# Remove this line. Use tls_outgoing_options capath= instead.
165#Default:
166# none
167
168# TAG: sslproxy_cipher
169# Remove this line. Use tls_outgoing_options cipher= instead.
170#Default:
171# none
172
173# TAG: sslproxy_client_certificate
174# Remove this line. Use tls_outgoing_options cert= instead.
175#Default:
176# none
177
178# TAG: sslproxy_client_key
179# Remove this line. Use tls_outgoing_options key= instead.
180#Default:
181# none
182
183# TAG: sslproxy_flags
184# Remove this line. Use tls_outgoing_options flags= instead.
185#Default:
186# none
187
188# TAG: sslproxy_options
189# Remove this line. Use tls_outgoing_options options= instead.
190#Default:
191# none
192
193# TAG: sslproxy_version
194# Remove this line. Use tls_outgoing_options options= instead.
195#Default:
196# none
197
198# TAG: hierarchy_stoplist
199# Remove this line. Use always_direct or cache_peer_access ACLs instead if you need to prevent cache_peer use.
200#Default:
201# none
202
203# TAG: log_access
204# Remove this line. Use acls with access_log directives to control access logging
205#Default:
206# none
207
208# TAG: log_icap
209# Remove this line. Use acls with icap_log directives to control icap logging
210#Default:
211# none
212
213# TAG: ignore_ims_on_miss
214# Remove this line. The HTTP/1.1 feature is now configured by 'cache_miss_revalidate'.
215#Default:
216# none
217
218# TAG: balance_on_multiple_ip
219# Remove this line. Squid performs a 'Happy Eyeballs' algorithm, this multiple-IP algorithm is not longer relevant.
220#Default:
221# none
222
223# TAG: chunked_request_body_max_size
224# Remove this line. Squid is now HTTP/1.1 compliant.
225#Default:
226# none
227
228# TAG: dns_v4_fallback
229# Remove this line. Squid performs a 'Happy Eyeballs' algorithm, the 'fallback' algorithm is no longer relevant.
230#Default:
231# none
232
233# TAG: emulate_httpd_log
234# Replace this with an access_log directive using the format 'common' or 'combined'.
235#Default:
236# none
237
238# TAG: forward_log
239# Use a regular access.log with ACL limiting it to MISS events.
240#Default:
241# none
242
243# TAG: ftp_list_width
244# Remove this line. Configure FTP page display using the CSS controls in errorpages.css instead.
245#Default:
246# none
247
248# TAG: ignore_expect_100
249# Remove this line. The HTTP/1.1 feature is now fully supported by default.
250#Default:
251# none
252
253# TAG: log_fqdn
254# Remove this option from your config. To log FQDN use %>A in the log format.
255#Default:
256# none
257
258# TAG: log_ip_on_direct
259# Remove this option from your config. To log server or peer names use %<A in the log format.
260#Default:
261# none
262
263# TAG: maximum_single_addr_tries
264# Replaced by connect_retries. The behaviour has changed, please read the documentation before altering.
265#Default:
266# none
267
268# TAG: referer_log
269# Replace this with an access_log directive using the format 'referrer'.
270#Default:
271# none
272
273# TAG: update_headers
274# Remove this line. The feature is supported by default in storage types where update is implemented.
275#Default:
276# none
277
278# TAG: url_rewrite_concurrency
279# Remove this line. Set the 'concurrency=' option of url_rewrite_children instead.
280#Default:
281# none
282
283# TAG: useragent_log
284# Replace this with an access_log directive using the format 'useragent'.
285#Default:
286# none
287
288# TAG: dns_testnames
289# Remove this line. DNS is no longer tested on startup.
290#Default:
291# none
292
293# TAG: extension_methods
294# Remove this line. All valid methods for HTTP are accepted by default.
295#Default:
296# none
297
298# TAG: zero_buffers
299#Default:
300# none
301
302# TAG: incoming_rate
303#Default:
304# none
305
306# TAG: server_http11
307# Remove this line. HTTP/1.1 is supported by default.
308#Default:
309# none
310
311# TAG: upgrade_http0.9
312# Remove this line. ICY/1.0 streaming protocol is supported by default.
313#Default:
314# none
315
316# TAG: zph_local
317# Alter these entries. Use the qos_flows directive instead.
318#Default:
319# none
320
321# TAG: header_access
322# Since squid-3.0 replace with request_header_access or reply_header_access
323# depending on whether you wish to match client requests or server replies.
324#Default:
325# none
326
327# TAG: httpd_accel_no_pmtu_disc
328# Since squid-3.0 use the 'disable-pmtu-discovery' flag on http_port instead.
329#Default:
330# none
331
332# TAG: wais_relay_host
333# Replace this line with 'cache_peer' configuration.
334#Default:
335# none
336
337# TAG: wais_relay_port
338# Replace this line with 'cache_peer' configuration.
339#Default:
340# none
341
342# OPTIONS FOR SMP
343# -----------------------------------------------------------------------------
344
345# TAG: workers
346# Number of main Squid processes or "workers" to fork and maintain.
347# 0: "no daemon" mode, like running "squid -N ..."
348# 1: "no SMP" mode, start one main Squid process daemon (default)
349# N: start N main Squid process daemons (i.e., SMP mode)
350#
351# In SMP mode, each worker does nearly all what a single Squid daemon
352# does (e.g., listen on http_port and forward HTTP requests).
353#Default:
354# SMP support disabled.
355
356# TAG: cpu_affinity_map
357# Usage: cpu_affinity_map process_numbers=P1,P2,... cores=C1,C2,...
358#
359# Sets 1:1 mapping between Squid processes and CPU cores. For example,
360#
361# cpu_affinity_map process_numbers=1,2,3,4 cores=1,3,5,7
362#
363# affects processes 1 through 4 only and places them on the first
364# four even cores, starting with core #1.
365#
366# CPU cores are numbered starting from 1. Requires support for
367# sched_getaffinity(2) and sched_setaffinity(2) system calls.
368#
369# Multiple cpu_affinity_map options are merged.
370#
371# See also: workers
372#Default:
373# Let operating system decide.
374
375# TAG: shared_memory_locking on|off
376# Whether to ensure that all required shared memory is available by
377# "locking" that shared memory into RAM when Squid starts. The
378# alternative is faster startup time followed by slightly slower
379# performance and, if not enough RAM is actually available during
380# runtime, mysterious crashes.
381#
382# SMP Squid uses many shared memory segments. These segments are
383# brought into Squid memory space using an mmap(2) system call. During
384# Squid startup, the mmap() call often succeeds regardless of whether
385# the system has enough RAM. In general, Squid cannot tell whether the
386# kernel applies this "optimistic" memory allocation policy (but
387# popular modern kernels usually use it).
388#
389# Later, if Squid attempts to actually access the mapped memory
390# regions beyond what the kernel is willing to allocate, the
391# "optimistic" kernel simply kills Squid kid with a SIGBUS signal.
392# Some of the memory limits enforced by the kernel are currently
393# poorly understood: We do not know how to detect and check them. This
394# option ensures that the mapped memory will be available.
395#
396# This option may have a positive performance side-effect: Locking
397# memory at start avoids runtime paging I/O. Paging slows Squid down.
398#
399# Locking memory may require a large enough RLIMIT_MEMLOCK OS limit,
400# CAP_IPC_LOCK capability, or equivalent.
401#Default:
402# shared_memory_locking off
403
404# TAG: hopeless_kid_revival_delay time-units
405# Normally, when a kid process dies, Squid immediately restarts the
406# kid. A kid experiencing frequent deaths is marked as "hopeless" for
407# the duration specified by this directive. Hopeless kids are not
408# automatically restarted.
409#
410# Currently, zero values are not supported because they result in
411# misconfigured SMP Squid instances running forever, endlessly
412# restarting each dying kid. To effectively disable hopeless kids
413# revival, set the delay to a huge value (e.g., 1 year).
414#
415# Reconfiguration also clears all hopeless kids designations, allowing
416# for manual revival of hopeless kids.
417#Default:
418# hopeless_kid_revival_delay 1 hour
419
420# OPTIONS FOR AUTHENTICATION
421# -----------------------------------------------------------------------------
422
423# TAG: auth_param
424# This is used to define parameters for the various authentication
425# schemes supported by Squid.
426#
427# format: auth_param scheme parameter [setting]
428#
429# The order in which authentication schemes are presented to the client is
430# dependent on the order the scheme first appears in config file. IE
431# has a bug (it's not RFC 2617 compliant) in that it will use the basic
432# scheme if basic is the first entry presented, even if more secure
433# schemes are presented. For now use the order in the recommended
434# settings section below. If other browsers have difficulties (don't
435# recognize the schemes offered even if you are using basic) either
436# put basic first, or disable the other schemes (by commenting out their
437# program entry).
438#
439# Once an authentication scheme is fully configured, it can only be
440# shutdown by shutting squid down and restarting. Changes can be made on
441# the fly and activated with a reconfigure. I.E. You can change to a
442# different helper, but not unconfigure the helper completely.
443#
444# Please note that while this directive defines how Squid processes
445# authentication it does not automatically activate authentication.
446# To use authentication you must in addition make use of ACLs based
447# on login name in http_access (proxy_auth, proxy_auth_regex or
448# external with %LOGIN used in the format tag). The browser will be
449# challenged for authentication on the first such acl encountered
450# in http_access processing and will also be re-challenged for new
451# login credentials if the request is being denied by a proxy_auth
452# type acl.
453#
454# WARNING: authentication can't be used in a transparently intercepting
455# proxy as the client then thinks it is talking to an origin server and
456# not the proxy. This is a limitation of bending the TCP/IP protocol to
457# transparently intercepting port 80, not a limitation in Squid.
458# Ports flagged 'transparent', 'intercept', or 'tproxy' have
459# authentication disabled.
460#
461# === Parameters common to all schemes. ===
462#
463# "program" cmdline
464# Specifies the command for the external authenticator.
465#
466# By default, each authentication scheme is not used unless a
467# program is specified.
468#
469# See http://wiki.squid-cache.org/Features/AddonHelpers for
470# more details on helper operations and creating your own.
471#
472# "key_extras" format
473# Specifies a string to be append to request line format for
474# the authentication helper. "Quoted" format values may contain
475# spaces and logformat %macros. In theory, any logformat %macro
476# can be used. In practice, a %macro expands as a dash (-) if
477# the helper request is sent before the required macro
478# information is available to Squid.
479#
480# By default, Squid uses request formats provided in
481# scheme-specific examples below (search for %credentials).
482#
483# The expanded key_extras value is added to the Squid credentials
484# cache and, hence, will affect authentication. It can be used to
485# autenticate different users with identical user names (e.g.,
486# when user authentication depends on http_port).
487#
488# Avoid adding frequently changing information to key_extras. For
489# example, if you add user source IP, and it changes frequently
490# in your environment, then max_user_ip ACL is going to treat
491# every user+IP combination as a unique "user", breaking the ACL
492# and wasting a lot of memory on those user records. It will also
493# force users to authenticate from scratch whenever their IP
494# changes.
495#
496# "realm" string
497# Specifies the protection scope (aka realm name) which is to be
498# reported to the client for the authentication scheme. It is
499# commonly part of the text the user will see when prompted for
500# their username and password.
501#
502# For Basic the default is "Squid proxy-caching web server".
503# For Digest there is no default, this parameter is mandatory.
504# For NTLM and Negotiate this parameter is ignored.
505#
506# "children" numberofchildren [startup=N] [idle=N] [concurrency=N]
507# [queue-size=N] [on-persistent-overload=action]
508#
509# The maximum number of authenticator processes to spawn. If
510# you start too few Squid will have to wait for them to process
511# a backlog of credential verifications, slowing it down. When
512# password verifications are done via a (slow) network you are
513# likely to need lots of authenticator processes.
514#
515# The startup= and idle= options permit some skew in the exact
516# amount run. A minimum of startup=N will begin during startup
517# and reconfigure. Squid will start more in groups of up to
518# idle=N in an attempt to meet traffic needs and to keep idle=N
519# free above those traffic needs up to the maximum.
520#
521# The concurrency= option sets the number of concurrent requests
522# the helper can process. The default of 0 is used for helpers
523# who only supports one request at a time. Setting this to a
524# number greater than 0 changes the protocol used to include a
525# channel ID field first on the request/response line, allowing
526# multiple requests to be sent to the same helper in parallel
527# without waiting for the response.
528#
529# Concurrency must not be set unless it's known the helper
530# supports the input format with channel-ID fields.
531#
532# The queue-size option sets the maximum number of queued
533# requests. A request is queued when no existing child can
534# accept it due to concurrency limit and no new child can be
535# started due to numberofchildren limit. The default maximum is
536# 2*numberofchildren. Squid is allowed to temporarily exceed the
537# configured maximum, marking the affected helper as
538# "overloaded". If the helper overload lasts more than 3
539# minutes, the action prescribed by the on-persistent-overload
540# option applies.
541#
542# The on-persistent-overload=action option specifies Squid
543# reaction to a new helper request arriving when the helper
544# has been overloaded for more that 3 minutes already. The number
545# of queued requests determines whether the helper is overloaded
546# (see the queue-size option).
547#
548# Two actions are supported:
549#
550# die Squid worker quits. This is the default behavior.
551#
552# ERR Squid treats the helper request as if it was
553# immediately submitted, and the helper immediately
554# replied with an ERR response. This action has no effect
555# on the already queued and in-progress helper requests.
556#
557# NOTE: NTLM and Negotiate schemes do not support concurrency
558# in the Squid code module even though some helpers can.
559#
560#
561#
562# === Example Configuration ===
563#
564# This configuration displays the recommended authentication scheme
565# order from most to least secure with recommended minimum configuration
566# settings for each scheme:
567#
568##auth_param negotiate program <uncomment and complete this line to activate>
569##auth_param negotiate children 20 startup=0 idle=1
570##auth_param negotiate keep_alive on
571##
572##auth_param digest program <uncomment and complete this line to activate>
573##auth_param digest children 20 startup=0 idle=1
574##auth_param digest realm Squid proxy-caching web server
575##auth_param digest nonce_garbage_interval 5 minutes
576##auth_param digest nonce_max_duration 30 minutes
577##auth_param digest nonce_max_count 50
578##
579##auth_param ntlm program <uncomment and complete this line to activate>
580##auth_param ntlm children 20 startup=0 idle=1
581##auth_param ntlm keep_alive on
582##
583##auth_param basic program <uncomment and complete this line>
584##auth_param basic children 5 startup=5 idle=1
585##auth_param basic realm Squid proxy-caching web server
586##auth_param basic credentialsttl 2 hours
587#Default:
588# none
589
590# TAG: authenticate_cache_garbage_interval
591# The time period between garbage collection across the username cache.
592# This is a trade-off between memory utilization (long intervals - say
593# 2 days) and CPU (short intervals - say 1 minute). Only change if you
594# have good reason to.
595#Default:
596# authenticate_cache_garbage_interval 1 hour
597
598# TAG: authenticate_ttl
599# The time a user & their credentials stay in the logged in
600# user cache since their last request. When the garbage
601# interval passes, all user credentials that have passed their
602# TTL are removed from memory.
603#Default:
604# authenticate_ttl 1 hour
605
606# TAG: authenticate_ip_ttl
607# If you use proxy authentication and the 'max_user_ip' ACL,
608# this directive controls how long Squid remembers the IP
609# addresses associated with each user. Use a small value
610# (e.g., 60 seconds) if your users might change addresses
611# quickly, as is the case with dialup. You might be safe
612# using a larger value (e.g., 2 hours) in a corporate LAN
613# environment with relatively static address assignments.
614#Default:
615# authenticate_ip_ttl 1 second
616
617# ACCESS CONTROLS
618# -----------------------------------------------------------------------------
619
620# TAG: external_acl_type
621# This option defines external acl classes using a helper program
622# to look up the status
623#
624# external_acl_type name [options] FORMAT /path/to/helper [helper arguments]
625#
626# Options:
627#
628# ttl=n TTL in seconds for cached results (defaults to 3600
629# for 1 hour)
630#
631# negative_ttl=n
632# TTL for cached negative lookups (default same
633# as ttl)
634#
635# grace=n Percentage remaining of TTL where a refresh of a
636# cached entry should be initiated without needing to
637# wait for a new reply. (default is for no grace period)
638#
639# cache=n The maximum number of entries in the result cache. The
640# default limit is 262144 entries. Each cache entry usually
641# consumes at least 256 bytes. Squid currently does not remove
642# expired cache entries until the limit is reached, so a proxy
643# will sooner or later reach the limit. The expanded FORMAT
644# value is used as the cache key, so if the details in FORMAT
645# are highly variable, a larger cache may be needed to produce
646# reduction in helper load.
647#
648# children-max=n
649# Maximum number of acl helper processes spawned to service
650# external acl lookups of this type. (default 5)
651#
652# children-startup=n
653# Minimum number of acl helper processes to spawn during
654# startup and reconfigure to service external acl lookups
655# of this type. (default 0)
656#
657# children-idle=n
658# Number of acl helper processes to keep ahead of traffic
659# loads. Squid will spawn this many at once whenever load
660# rises above the capabilities of existing processes.
661# Up to the value of children-max. (default 1)
662#
663# concurrency=n concurrency level per process. Only used with helpers
664# capable of processing more than one query at a time.
665#
666# queue-size=N The queue-size option sets the maximum number of
667# queued requests. A request is queued when no existing
668# helper can accept it due to concurrency limit and no
669# new helper can be started due to children-max limit.
670# If the queued requests exceed queue size, the acl is
671# ignored. The default value is set to 2*children-max.
672#
673# protocol=2.5 Compatibility mode for Squid-2.5 external acl helpers.
674#
675# ipv4 / ipv6 IP protocol used to communicate with this helper.
676# The default is to auto-detect IPv6 and use it when available.
677#
678#
679# FORMAT is a series of %macro codes. See logformat directive for a full list
680# of the accepted codes. Although note that at the time of any external ACL
681# being tested data may not be available and thus some %macro expand to '-'.
682#
683# In addition to the logformat codes; when processing external ACLs these
684# additional macros are made available:
685#
686# %ACL The name of the ACL being tested.
687#
688# %DATA The ACL arguments specified in the referencing config
689# 'acl ... external' line, separated by spaces (an
690# "argument string"). see acl external.
691#
692# If there are no ACL arguments %DATA expands to '-'.
693#
694# If you do not specify a DATA macro inside FORMAT,
695# Squid automatically appends %DATA to your FORMAT.
696# Note that Squid-3.x may expand %DATA to whitespace
697# or nothing in this case.
698#
699# By default, Squid applies URL-encoding to each ACL
700# argument inside the argument string. If an explicit
701# encoding modifier is used (e.g., %#DATA), then Squid
702# encodes the whole argument string as a single token
703# (e.g., with %#DATA, spaces between arguments become
704# %20).
705#
706# If SSL is enabled, the following formating codes become available:
707#
708# %USER_CERT SSL User certificate in PEM format
709# %USER_CERTCHAIN SSL User certificate chain in PEM format
710# %USER_CERT_xx SSL User certificate subject attribute xx
711# %USER_CA_CERT_xx SSL User certificate issuer attribute xx
712#
713#
714# NOTE: all other format codes accepted by older Squid versions
715# are deprecated.
716#
717#
718# General request syntax:
719#
720# [channel-ID] FORMAT-values
721#
722#
723# FORMAT-values consists of transaction details expanded with
724# whitespace separation per the config file FORMAT specification
725# using the FORMAT macros listed above.
726#
727# Request values sent to the helper are URL escaped to protect
728# each value in requests against whitespaces.
729#
730# If using protocol=2.5 then the request sent to the helper is not
731# URL escaped to protect against whitespace.
732#
733# NOTE: protocol=3.0 is deprecated as no longer necessary.
734#
735# When using the concurrency= option the protocol is changed by
736# introducing a query channel tag in front of the request/response.
737# The query channel tag is a number between 0 and concurrency-1.
738# This value must be echoed back unchanged to Squid as the first part
739# of the response relating to its request.
740#
741#
742# The helper receives lines expanded per the above format specification
743# and for each input line returns 1 line starting with OK/ERR/BH result
744# code and optionally followed by additional keywords with more details.
745#
746#
747# General result syntax:
748#
749# [channel-ID] result keyword=value ...
750#
751# Result consists of one of the codes:
752#
753# OK
754# the ACL test produced a match.
755#
756# ERR
757# the ACL test does not produce a match.
758#
759# BH
760# An internal error occurred in the helper, preventing
761# a result being identified.
762#
763# The meaning of 'a match' is determined by your squid.conf
764# access control configuration. See the Squid wiki for details.
765#
766# Defined keywords:
767#
768# user= The users name (login)
769#
770# password= The users password (for login= cache_peer option)
771#
772# message= Message describing the reason for this response.
773# Available as %o in error pages.
774# Useful on (ERR and BH results).
775#
776# tag= Apply a tag to a request. Only sets a tag once,
777# does not alter existing tags.
778#
779# log= String to be logged in access.log. Available as
780# %ea in logformat specifications.
781#
782# clt_conn_tag= Associates a TAG with the client TCP connection.
783# Please see url_rewrite_program related documentation
784# for this kv-pair.
785#
786# Any keywords may be sent on any response whether OK, ERR or BH.
787#
788# All response keyword values need to be a single token with URL
789# escaping, or enclosed in double quotes (") and escaped using \ on
790# any double quotes or \ characters within the value. The wrapping
791# double quotes are removed before the value is interpreted by Squid.
792# \r and \n are also replace by CR and LF.
793#
794# Some example key values:
795#
796# user=John%20Smith
797# user="John Smith"
798# user="J. \"Bob\" Smith"
799#Default:
800# none
801
802# TAG: acl
803# Defining an Access List
804#
805# Every access list definition must begin with an aclname and acltype,
806# followed by either type-specific arguments or a quoted filename that
807# they are read from.
808#
809# acl aclname acltype argument ...
810# acl aclname acltype "file" ...
811#
812# When using "file", the file should contain one item per line.
813#
814#
815# ACL Options
816#
817# Some acl types supports options which changes their default behaviour:
818#
819# -i,+i By default, regular expressions are CASE-SENSITIVE. To make them
820# case-insensitive, use the -i option. To return case-sensitive
821# use the +i option between patterns, or make a new ACL line
822# without -i.
823#
824# -n Disable lookups and address type conversions. If lookup or
825# conversion is required because the parameter type (IP or
826# domain name) does not match the message address type (domain
827# name or IP), then the ACL would immediately declare a mismatch
828# without any warnings or lookups.
829#
830# -m[=delimiters]
831# Perform a list membership test, interpreting values as
832# comma-separated token lists and matching against individual
833# tokens instead of whole values.
834# The optional "delimiters" parameter specifies one or more
835# alternative non-alphanumeric delimiter characters.
836# non-alphanumeric delimiter characters.
837#
838# -- Used to stop processing all options, in the case the first acl
839# value has '-' character as first character (for example the '-'
840# is a valid domain name)
841#
842# Some acl types require suspending the current request in order
843# to access some external data source.
844# Those which do are marked with the tag [slow], those which
845# don't are marked as [fast].
846# See http://wiki.squid-cache.org/SquidFaq/SquidAcl
847# for further information
848#
849# ***** ACL TYPES AVAILABLE *****
850#
851# acl aclname src ip-address/mask ... # clients IP address [fast]
852# acl aclname src addr1-addr2/mask ... # range of addresses [fast]
853# acl aclname dst [-n] ip-address/mask ... # URL host's IP address [slow]
854# acl aclname localip ip-address/mask ... # IP address the client connected to [fast]
855#
856#if USE_SQUID_EUI
857# acl aclname arp mac-address ...
858# acl aclname eui64 eui64-address ...
859# # [fast]
860# # MAC (EUI-48) and EUI-64 addresses use xx:xx:xx:xx:xx:xx notation.
861# #
862# # The 'arp' ACL code is not portable to all operating systems.
863# # It works on Linux, Solaris, Windows, FreeBSD, and some other
864# # BSD variants.
865# #
866# # The eui_lookup directive is required to be 'on' (the default)
867# # and Squid built with --enable-eui for MAC/EUI addresses to be
868# # available for this ACL.
869# #
870# # Squid can only determine the MAC/EUI address for IPv4
871# # clients that are on the same subnet. If the client is on a
872# # different subnet, then Squid cannot find out its address.
873# #
874# # IPv6 protocol does not contain ARP. MAC/EUI is either
875# # encoded directly in the IPv6 address or not available.
876#endif
877# acl aclname clientside_mark mark[/mask] ...
878# # matches CONNMARK of an accepted connection [fast]
879# #
880# # mark and mask are unsigned integers (hex, octal, or decimal).
881# # If multiple marks are given, then the ACL matches if at least
882# # one mark matches.
883# #
884# # Uses netfilter-conntrack library.
885# # Requires building Squid with --enable-linux-netfilter.
886# #
887# # The client, various intermediaries, and Squid itself may set
888# # CONNMARK at various times. The last CONNMARK set wins. This ACL
889# # checks the mark present on an accepted connection or set by
890# # Squid afterwards, depending on the ACL check timing. This ACL
891# # effectively ignores any mark set by other agents after Squid has
892# # accepted the connection.
893#
894# acl aclname srcdomain .foo.com ...
895# # reverse lookup, from client IP [slow]
896# acl aclname dstdomain [-n] .foo.com ...
897# # Destination server from URL [fast]
898# acl aclname srcdom_regex [-i] \.foo\.com ...
899# # regex matching client name [slow]
900# acl aclname dstdom_regex [-n] [-i] \.foo\.com ...
901# # regex matching server [fast]
902# #
903# # For dstdomain and dstdom_regex a reverse lookup is tried if a IP
904# # based URL is used and no match is found. The name "none" is used
905# # if the reverse lookup fails.
906#
907# acl aclname src_as number ...
908# acl aclname dst_as number ...
909# # [fast]
910# # Except for access control, AS numbers can be used for
911# # routing of requests to specific caches. Here's an
912# # example for routing all requests for AS#1241 and only
913# # those to mycache.mydomain.net:
914# # acl asexample dst_as 1241
915# # cache_peer_access mycache.mydomain.net allow asexample
916# # cache_peer_access mycache_mydomain.net deny all
917#
918# acl aclname peername myPeer ...
919# acl aclname peername_regex [-i] regex-pattern ...
920# # [fast]
921# # match against a named cache_peer entry
922# # set unique name= on cache_peer lines for reliable use.
923#
924# acl aclname time [day-abbrevs] [h1:m1-h2:m2]
925# # [fast]
926# # day-abbrevs:
927# # S - Sunday
928# # M - Monday
929# # T - Tuesday
930# # W - Wednesday
931# # H - Thursday
932# # F - Friday
933# # A - Saturday
934# # h1:m1 must be less than h2:m2
935#
936# acl aclname url_regex [-i] ^http:// ...
937# # regex matching on whole URL [fast]
938# acl aclname urllogin [-i] [^a-zA-Z0-9] ...
939# # regex matching on URL login field
940# acl aclname urlpath_regex [-i] \.gif$ ...
941# # regex matching on URL path [fast]
942#
943# acl aclname port 80 70 21 0-1024... # destination TCP port [fast]
944# # ranges are alloed
945# acl aclname localport 3128 ... # TCP port the client connected to [fast]
946# # NP: for interception mode this is usually '80'
947#
948# acl aclname myportname 3128 ... # *_port name [fast]
949#
950# acl aclname proto HTTP FTP ... # request protocol [fast]
951#
952# acl aclname method GET POST ... # HTTP request method [fast]
953#
954# acl aclname http_status 200 301 500- 400-403 ...
955# # status code in reply [fast]
956#
957# acl aclname browser [-i] regexp ...
958# # pattern match on User-Agent header (see also req_header below) [fast]
959#
960# acl aclname referer_regex [-i] regexp ...
961# # pattern match on Referer header [fast]
962# # Referer is highly unreliable, so use with care
963#
964# acl aclname ident [-i] username ...
965# acl aclname ident_regex [-i] pattern ...
966# # string match on ident output [slow]
967# # use REQUIRED to accept any non-null ident.
968#
969# acl aclname proxy_auth [-i] username ...
970# acl aclname proxy_auth_regex [-i] pattern ...
971# # perform http authentication challenge to the client and match against
972# # supplied credentials [slow]
973# #
974# # takes a list of allowed usernames.
975# # use REQUIRED to accept any valid username.
976# #
977# # Will use proxy authentication in forward-proxy scenarios, and plain
978# # http authenticaiton in reverse-proxy scenarios
979# #
980# # NOTE: when a Proxy-Authentication header is sent but it is not
981# # needed during ACL checking the username is NOT logged
982# # in access.log.
983# #
984# # NOTE: proxy_auth requires a EXTERNAL authentication program
985# # to check username/password combinations (see
986# # auth_param directive).
987# #
988# # NOTE: proxy_auth can't be used in a transparent/intercepting proxy
989# # as the browser needs to be configured for using a proxy in order
990# # to respond to proxy authentication.
991#
992# acl aclname snmp_community string ...
993# # A community string to limit access to your SNMP Agent [fast]
994# # Example:
995# #
996# # acl snmppublic snmp_community public
997#
998# acl aclname maxconn number
999# # This will be matched when the client's IP address has
1000# # more than <number> TCP connections established. [fast]
1001# # NOTE: This only measures direct TCP links so X-Forwarded-For
1002# # indirect clients are not counted.
1003#
1004# acl aclname max_user_ip [-s] number
1005# # This will be matched when the user attempts to log in from more
1006# # than <number> different ip addresses. The authenticate_ip_ttl
1007# # parameter controls the timeout on the ip entries. [fast]
1008# # If -s is specified the limit is strict, denying browsing
1009# # from any further IP addresses until the ttl has expired. Without
1010# # -s Squid will just annoy the user by "randomly" denying requests.
1011# # (the counter is reset each time the limit is reached and a
1012# # request is denied)
1013# # NOTE: in acceleration mode or where there is mesh of child proxies,
1014# # clients may appear to come from multiple addresses if they are
1015# # going through proxy farms, so a limit of 1 may cause user problems.
1016#
1017# acl aclname random probability
1018# # Pseudo-randomly match requests. Based on the probability given.
1019# # Probability may be written as a decimal (0.333), fraction (1/3)
1020# # or ratio of matches:non-matches (3:5).
1021#
1022# acl aclname req_mime_type [-i] mime-type ...
1023# # regex match against the mime type of the request generated
1024# # by the client. Can be used to detect file upload or some
1025# # types HTTP tunneling requests [fast]
1026# # NOTE: This does NOT match the reply. You cannot use this
1027# # to match the returned file type.
1028#
1029# acl aclname req_header header-name [-i] any\.regex\.here
1030# # regex match against any of the known request headers. May be
1031# # thought of as a superset of "browser", "referer" and "mime-type"
1032# # ACL [fast]
1033#
1034# acl aclname rep_mime_type [-i] mime-type ...
1035# # regex match against the mime type of the reply received by
1036# # squid. Can be used to detect file download or some
1037# # types HTTP tunneling requests. [fast]
1038# # NOTE: This has no effect in http_access rules. It only has
1039# # effect in rules that affect the reply data stream such as
1040# # http_reply_access.
1041#
1042# acl aclname rep_header header-name [-i] any\.regex\.here
1043# # regex match against any of the known reply headers. May be
1044# # thought of as a superset of "browser", "referer" and "mime-type"
1045# # ACLs [fast]
1046#
1047# acl aclname external class_name [arguments...]
1048# # external ACL lookup via a helper class defined by the
1049# # external_acl_type directive [slow]
1050#
1051# acl aclname user_cert attribute values...
1052# # match against attributes in a user SSL certificate
1053# # attribute is one of DN/C/O/CN/L/ST or a numerical OID [fast]
1054#
1055# acl aclname ca_cert attribute values...
1056# # match against attributes a users issuing CA SSL certificate
1057# # attribute is one of DN/C/O/CN/L/ST or a numerical OID [fast]
1058#
1059# acl aclname ext_user [-i] username ...
1060# acl aclname ext_user_regex [-i] pattern ...
1061# # string match on username returned by external acl helper [slow]
1062# # use REQUIRED to accept any non-null user name.
1063#
1064# acl aclname tag tagvalue ...
1065# # string match on tag returned by external acl helper [fast]
1066# # DEPRECATED. Only the first tag will match with this ACL.
1067# # Use the 'note' ACL instead for handling multiple tag values.
1068#
1069# acl aclname hier_code codename ...
1070# # string match against squid hierarchy code(s); [fast]
1071# # e.g., DIRECT, PARENT_HIT, NONE, etc.
1072# #
1073# # NOTE: This has no effect in http_access rules. It only has
1074# # effect in rules that affect the reply data stream such as
1075# # http_reply_access.
1076#
1077# acl aclname note [-m[=delimiters]] name [value ...]
1078# # match transaction annotation [fast]
1079# # Without values, matches any annotation with a given name.
1080# # With value(s), matches any annotation with a given name that
1081# # also has one of the given values.
1082# # If the -m flag is used, then the value of the named
1083# # annotation is interpreted as a list of tokens, and the ACL
1084# # matches individual name=token pairs rather than whole
1085# # name=value pairs. See "ACL Options" above for more info.
1086# # Annotation sources include note and adaptation_meta directives
1087# # as well as helper and eCAP responses.
1088#
1089# acl aclname adaptation_service service ...
1090# # Matches the name of any icap_service, ecap_service,
1091# # adaptation_service_set, or adaptation_service_chain that Squid
1092# # has used (or attempted to use) for the master transaction.
1093# # This ACL must be defined after the corresponding adaptation
1094# # service is named in squid.conf. This ACL is usable with
1095# # adaptation_meta because it starts matching immediately after
1096# # the service has been selected for adaptation.
1097#
1098# acl aclname transaction_initiator initiator ...
1099# # Matches transaction's initiator [fast]
1100# #
1101# # Supported initiators are:
1102# # esi: matches transactions fetching ESI resources
1103# # certificate-fetching: matches transactions fetching
1104# # a missing intermediate TLS certificate
1105# # cache-digest: matches transactions fetching Cache Digests
1106# # from a cache_peer
1107# # htcp: matches HTCP requests from peers
1108# # icp: matches ICP requests to peers
1109# # icmp: matches ICMP RTT database (NetDB) requests to peers
1110# # asn: matches asns db requests
1111# # internal: matches any of the above
1112# # client: matches transactions containing an HTTP or FTP
1113# # client request received at a Squid *_port
1114# # all: matches any transaction, including internal transactions
1115# # without a configurable initiator and hopefully rare
1116# # transactions without a known-to-Squid initiator
1117# #
1118# # Multiple initiators are ORed.
1119#
1120# acl aclname has component
1121# # matches a transaction "component" [fast]
1122# #
1123# # Supported transaction components are:
1124# # request: transaction has a request header (at least)
1125# # response: transaction has a response header (at least)
1126# # ALE: transaction has an internally-generated Access Log Entry
1127# # structure; bugs notwithstanding, all transaction have it
1128# #
1129# # For example, the following configuration helps when dealing with HTTP
1130# # clients that close connections without sending a request header:
1131# #
1132# # acl hasRequest has request
1133# # acl logMe note important_transaction
1134# # # avoid "logMe ACL is used in context without an HTTP request" warnings
1135# # access_log ... logformat=detailed hasRequest logMe
1136# # # log request-less transactions, instead of ignoring them
1137# # access_log ... logformat=brief !hasRequest
1138# #
1139# # Multiple components are not supported for one "acl" rule, but
1140# # can be specified (and are ORed) using multiple same-name rules:
1141# #
1142# # # OK, this strange logging daemon needs request or response,
1143# # # but can work without either a request or a response:
1144# # acl hasWhatMyLoggingDaemonNeeds has request
1145# # acl hasWhatMyLoggingDaemonNeeds has response
1146#
1147# acl aclname any-of acl1 acl2 ...
1148# # match any one of the acls [fast or slow]
1149# # The first matching ACL stops further ACL evaluation.
1150# #
1151# # ACLs from multiple any-of lines with the same name are ORed.
1152# # For example, A = (a1 or a2) or (a3 or a4) can be written as
1153# # acl A any-of a1 a2
1154# # acl A any-of a3 a4
1155# #
1156# # This group ACL is fast if all evaluated ACLs in the group are fast
1157# # and slow otherwise.
1158#
1159# acl aclname all-of acl1 acl2 ...
1160# # match all of the acls [fast or slow]
1161# # The first mismatching ACL stops further ACL evaluation.
1162# #
1163# # ACLs from multiple all-of lines with the same name are ORed.
1164# # For example, B = (b1 and b2) or (b3 and b4) can be written as
1165# # acl B all-of b1 b2
1166# # acl B all-of b3 b4
1167# #
1168# # This group ACL is fast if all evaluated ACLs in the group are fast
1169# # and slow otherwise.
1170#
1171# Examples:
1172# acl macaddress arp 09:00:2b:23:45:67
1173# acl myexample dst_as 1241
1174# acl password proxy_auth REQUIRED
1175# acl fileupload req_mime_type -i ^multipart/form-data$
1176# acl javascript rep_mime_type -i ^application/x-javascript$
1177#
1178#Default:
1179# ACLs all, manager, localhost, and to_localhost are predefined.
1180#
1181#
1182# Recommended minimum configuration:
1183#
1184
1185# Example rule allowing access from your local networks.
1186# Adapt to list your (internal) IP networks from where browsing
1187# should be allowed
1188acl localnet src 0.0.0.1-0.255.255.255 # RFC 1122 "this" network (LAN)
1189acl localnet src 10.0.0.0/8 # RFC 1918 local private network (LAN)
1190acl localnet src 100.64.0.0/10 # RFC 6598 shared address space (CGN)
1191acl localnet src 169.254.0.0/16 # RFC 3927 link-local (directly plugged) machines
1192acl localnet src 172.16.0.0/12 # RFC 1918 local private network (LAN)
1193acl localnet src 192.168.0.0/16 # RFC 1918 local private network (LAN)
1194acl localnet src fc00::/7 # RFC 4193 local private network range
1195acl localnet src fe80::/10 # RFC 4291 link-local (directly plugged) machines
1196
1197acl SSL_ports port 443
1198acl Safe_ports port 80 # http
1199acl Safe_ports port 21 # ftp
1200acl Safe_ports port 443 # https
1201acl Safe_ports port 70 # gopher
1202acl Safe_ports port 210 # wais
1203acl Safe_ports port 1025-65535 # unregistered ports
1204acl Safe_ports port 280 # http-mgmt
1205acl Safe_ports port 488 # gss-http
1206acl Safe_ports port 591 # filemaker
1207acl Safe_ports port 777 # multiling http
1208acl CONNECT method CONNECT
1209
1210# TAG: proxy_protocol_access
1211# Determine which client proxies can be trusted to provide correct
1212# information regarding real client IP address using PROXY protocol.
1213#
1214# Requests may pass through a chain of several other proxies
1215# before reaching us. The original source details may by sent in:
1216# * HTTP message Forwarded header, or
1217# * HTTP message X-Forwarded-For header, or
1218# * PROXY protocol connection header.
1219#
1220# This directive is solely for validating new PROXY protocol
1221# connections received from a port flagged with require-proxy-header.
1222# It is checked only once after TCP connection setup.
1223#
1224# A deny match results in TCP connection closure.
1225#
1226# An allow match is required for Squid to permit the corresponding
1227# TCP connection, before Squid even looks for HTTP request headers.
1228# If there is an allow match, Squid starts using PROXY header information
1229# to determine the source address of the connection for all future ACL
1230# checks, logging, etc.
1231#
1232# SECURITY CONSIDERATIONS:
1233#
1234# Any host from which we accept client IP details can place
1235# incorrect information in the relevant header, and Squid
1236# will use the incorrect information as if it were the
1237# source address of the request. This may enable remote
1238# hosts to bypass any access control restrictions that are
1239# based on the client's source addresses.
1240#
1241# This clause only supports fast acl types.
1242# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1243#Default:
1244# all TCP connections to ports with require-proxy-header will be denied
1245
1246# TAG: follow_x_forwarded_for
1247# Determine which client proxies can be trusted to provide correct
1248# information regarding real client IP address.
1249#
1250# Requests may pass through a chain of several other proxies
1251# before reaching us. The original source details may by sent in:
1252# * HTTP message Forwarded header, or
1253# * HTTP message X-Forwarded-For header, or
1254# * PROXY protocol connection header.
1255#
1256# PROXY protocol connections are controlled by the proxy_protocol_access
1257# directive which is checked before this.
1258#
1259# If a request reaches us from a source that is allowed by this
1260# directive, then we trust the information it provides regarding
1261# the IP of the client it received from (if any).
1262#
1263# For the purpose of ACLs used in this directive the src ACL type always
1264# matches the address we are testing and srcdomain matches its rDNS.
1265#
1266# On each HTTP request Squid checks for X-Forwarded-For header fields.
1267# If found the header values are iterated in reverse order and an allow
1268# match is required for Squid to continue on to the next value.
1269# The verification ends when a value receives a deny match, cannot be
1270# tested, or there are no more values to test.
1271# NOTE: Squid does not yet follow the Forwarded HTTP header.
1272#
1273# The end result of this process is an IP address that we will
1274# refer to as the indirect client address. This address may
1275# be treated as the client address for access control, ICAP, delay
1276# pools and logging, depending on the acl_uses_indirect_client,
1277# icap_uses_indirect_client, delay_pool_uses_indirect_client,
1278# log_uses_indirect_client and tproxy_uses_indirect_client options.
1279#
1280# This clause only supports fast acl types.
1281# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1282#
1283# SECURITY CONSIDERATIONS:
1284#
1285# Any host from which we accept client IP details can place
1286# incorrect information in the relevant header, and Squid
1287# will use the incorrect information as if it were the
1288# source address of the request. This may enable remote
1289# hosts to bypass any access control restrictions that are
1290# based on the client's source addresses.
1291#
1292# For example:
1293#
1294# acl localhost src 127.0.0.1
1295# acl my_other_proxy srcdomain .proxy.example.com
1296# follow_x_forwarded_for allow localhost
1297# follow_x_forwarded_for allow my_other_proxy
1298#Default:
1299# X-Forwarded-For header will be ignored.
1300
1301# TAG: acl_uses_indirect_client on|off
1302# Controls whether the indirect client address
1303# (see follow_x_forwarded_for) is used instead of the
1304# direct client address in acl matching.
1305#
1306# NOTE: maxconn ACL considers direct TCP links and indirect
1307# clients will always have zero. So no match.
1308#Default:
1309# acl_uses_indirect_client on
1310
1311# TAG: delay_pool_uses_indirect_client on|off
1312# Controls whether the indirect client address
1313# (see follow_x_forwarded_for) is used instead of the
1314# direct client address in delay pools.
1315#Default:
1316# delay_pool_uses_indirect_client on
1317
1318# TAG: log_uses_indirect_client on|off
1319# Controls whether the indirect client address
1320# (see follow_x_forwarded_for) is used instead of the
1321# direct client address in the access log.
1322#Default:
1323# log_uses_indirect_client on
1324
1325# TAG: tproxy_uses_indirect_client on|off
1326# Controls whether the indirect client address
1327# (see follow_x_forwarded_for) is used instead of the
1328# direct client address when spoofing the outgoing client.
1329#
1330# This has no effect on requests arriving in non-tproxy
1331# mode ports.
1332#
1333# SECURITY WARNING: Usage of this option is dangerous
1334# and should not be used trivially. Correct configuration
1335# of follow_x_forwarded_for with a limited set of trusted
1336# sources is required to prevent abuse of your proxy.
1337#Default:
1338# tproxy_uses_indirect_client off
1339
1340# TAG: spoof_client_ip
1341# Control client IP address spoofing of TPROXY traffic based on
1342# defined access lists.
1343#
1344# spoof_client_ip allow|deny [!]aclname ...
1345#
1346# If there are no "spoof_client_ip" lines present, the default
1347# is to "allow" spoofing of any suitable request.
1348#
1349# Note that the cache_peer "no-tproxy" option overrides this ACL.
1350#
1351# This clause supports fast acl types.
1352# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1353#Default:
1354# Allow spoofing on all TPROXY traffic.
1355
1356# TAG: http_access
1357# Allowing or Denying access based on defined access lists
1358#
1359# To allow or deny a message received on an HTTP, HTTPS, or FTP port:
1360# http_access allow|deny [!]aclname ...
1361#
1362# NOTE on default values:
1363#
1364# If there are no "access" lines present, the default is to deny
1365# the request.
1366#
1367# If none of the "access" lines cause a match, the default is the
1368# opposite of the last line in the list. If the last line was
1369# deny, the default is allow. Conversely, if the last line
1370# is allow, the default will be deny. For these reasons, it is a
1371# good idea to have an "deny all" entry at the end of your access
1372# lists to avoid potential confusion.
1373#
1374# This clause supports both fast and slow acl types.
1375# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1376#
1377#Default:
1378# Deny, unless rules exist in squid.conf.
1379#
1380
1381#
1382# Recommended minimum Access Permission configuration:
1383#
1384# Deny requests to certain unsafe ports
1385http_access deny !Safe_ports
1386
1387# Deny CONNECT to other than secure SSL ports
1388http_access deny CONNECT !SSL_ports
1389
1390# Only allow cachemgr access from localhost
1391http_access allow localhost manager
1392http_access deny manager
1393
1394# We strongly recommend the following be uncommented to protect innocent
1395# web applications running on the proxy server who think the only
1396# one who can access services on "localhost" is a local user
1397#http_access deny to_localhost
1398
1399#
1400# INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS
1401#
1402include /etc/squid/conf.d/*
1403
1404# Example rule allowing access from your local networks.
1405# Adapt localnet in the ACL section to list your (internal) IP networks
1406# from where browsing should be allowed
1407#http_access allow localnet
1408http_access allow localhost
1409
1410# And finally deny all other access to this proxy
1411http_access deny all
1412
1413# TAG: adapted_http_access
1414# Allowing or Denying access based on defined access lists
1415#
1416# Essentially identical to http_access, but runs after redirectors
1417# and ICAP/eCAP adaptation. Allowing access control based on their
1418# output.
1419#
1420# If not set then only http_access is used.
1421#Default:
1422# Allow, unless rules exist in squid.conf.
1423
1424# TAG: http_reply_access
1425# Allow replies to client requests. This is complementary to http_access.
1426#
1427# http_reply_access allow|deny [!] aclname ...
1428#
1429# NOTE: if there are no access lines present, the default is to allow
1430# all replies.
1431#
1432# If none of the access lines cause a match the opposite of the
1433# last line will apply. Thus it is good practice to end the rules
1434# with an "allow all" or "deny all" entry.
1435#
1436# This clause supports both fast and slow acl types.
1437# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1438#Default:
1439# Allow, unless rules exist in squid.conf.
1440
1441# TAG: icp_access
1442# Allowing or Denying access to the ICP port based on defined
1443# access lists
1444#
1445# icp_access allow|deny [!]aclname ...
1446#
1447# NOTE: The default if no icp_access lines are present is to
1448# deny all traffic. This default may cause problems with peers
1449# using ICP.
1450#
1451# This clause only supports fast acl types.
1452# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1453#
1454## Allow ICP queries from local networks only
1455##icp_access allow localnet
1456##icp_access deny all
1457#Default:
1458# Deny, unless rules exist in squid.conf.
1459
1460# TAG: htcp_access
1461# Allowing or Denying access to the HTCP port based on defined
1462# access lists
1463#
1464# htcp_access allow|deny [!]aclname ...
1465#
1466# See also htcp_clr_access for details on access control for
1467# cache purge (CLR) HTCP messages.
1468#
1469# NOTE: The default if no htcp_access lines are present is to
1470# deny all traffic. This default may cause problems with peers
1471# using the htcp option.
1472#
1473# This clause only supports fast acl types.
1474# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1475#
1476## Allow HTCP queries from local networks only
1477##htcp_access allow localnet
1478##htcp_access deny all
1479#Default:
1480# Deny, unless rules exist in squid.conf.
1481
1482# TAG: htcp_clr_access
1483# Allowing or Denying access to purge content using HTCP based
1484# on defined access lists.
1485# See htcp_access for details on general HTCP access control.
1486#
1487# htcp_clr_access allow|deny [!]aclname ...
1488#
1489# This clause only supports fast acl types.
1490# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1491#
1492## Allow HTCP CLR requests from trusted peers
1493#acl htcp_clr_peer src 192.0.2.2 2001:DB8::2
1494#htcp_clr_access allow htcp_clr_peer
1495#htcp_clr_access deny all
1496#Default:
1497# Deny, unless rules exist in squid.conf.
1498
1499# TAG: miss_access
1500# Determines whether network access is permitted when satisfying a request.
1501#
1502# For example;
1503# to force your neighbors to use you as a sibling instead of
1504# a parent.
1505#
1506# acl localclients src 192.0.2.0/24 2001:DB8::a:0/64
1507# miss_access deny !localclients
1508# miss_access allow all
1509#
1510# This means only your local clients are allowed to fetch relayed/MISS
1511# replies from the network and all other clients can only fetch cached
1512# objects (HITs).
1513#
1514# The default for this setting allows all clients who passed the
1515# http_access rules to relay via this proxy.
1516#
1517# This clause only supports fast acl types.
1518# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1519#Default:
1520# Allow, unless rules exist in squid.conf.
1521
1522# TAG: ident_lookup_access
1523# A list of ACL elements which, if matched, cause an ident
1524# (RFC 931) lookup to be performed for this request. For
1525# example, you might choose to always perform ident lookups
1526# for your main multi-user Unix boxes, but not for your Macs
1527# and PCs. By default, ident lookups are not performed for
1528# any requests.
1529#
1530# To enable ident lookups for specific client addresses, you
1531# can follow this example:
1532#
1533# acl ident_aware_hosts src 198.168.1.0/24
1534# ident_lookup_access allow ident_aware_hosts
1535# ident_lookup_access deny all
1536#
1537# Only src type ACL checks are fully supported. A srcdomain
1538# ACL might work at times, but it will not always provide
1539# the correct result.
1540#
1541# This clause only supports fast acl types.
1542# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1543#Default:
1544# Unless rules exist in squid.conf, IDENT is not fetched.
1545
1546# TAG: reply_body_max_size size [acl acl...]
1547# This option specifies the maximum size of a reply body. It can be
1548# used to prevent users from downloading very large files, such as
1549# MP3's and movies. When the reply headers are received, the
1550# reply_body_max_size lines are processed, and the first line where
1551# all (if any) listed ACLs are true is used as the maximum body size
1552# for this reply.
1553#
1554# This size is checked twice. First when we get the reply headers,
1555# we check the content-length value. If the content length value exists
1556# and is larger than the allowed size, the request is denied and the
1557# user receives an error message that says "the request or reply
1558# is too large." If there is no content-length, and the reply
1559# size exceeds this limit, the client's connection is just closed
1560# and they will receive a partial reply.
1561#
1562# WARNING: downstream caches probably can not detect a partial reply
1563# if there is no content-length header, so they will cache
1564# partial responses and give them out as hits. You should NOT
1565# use this option if you have downstream caches.
1566#
1567# WARNING: A maximum size smaller than the size of squid's error messages
1568# will cause an infinite loop and crash squid. Ensure that the smallest
1569# non-zero value you use is greater that the maximum header size plus
1570# the size of your largest error page.
1571#
1572# If you set this parameter none (the default), there will be
1573# no limit imposed.
1574#
1575# Configuration Format is:
1576# reply_body_max_size SIZE UNITS [acl ...]
1577# ie.
1578# reply_body_max_size 10 MB
1579#
1580#Default:
1581# No limit is applied.
1582
1583# TAG: on_unsupported_protocol
1584# Determines Squid behavior when encountering strange requests at the
1585# beginning of an accepted TCP connection or the beginning of a bumped
1586# CONNECT tunnel. Controlling Squid reaction to unexpected traffic is
1587# especially useful in interception environments where Squid is likely
1588# to see connections for unsupported protocols that Squid should either
1589# terminate or tunnel at TCP level.
1590#
1591# on_unsupported_protocol <action> [!]acl ...
1592#
1593# The first matching action wins. Only fast ACLs are supported.
1594#
1595# Supported actions are:
1596#
1597# tunnel: Establish a TCP connection with the intended server and
1598# blindly shovel TCP packets between the client and server.
1599#
1600# respond: Respond with an error message, using the transfer protocol
1601# for the Squid port that received the request (e.g., HTTP
1602# for connections intercepted at the http_port). This is the
1603# default.
1604#
1605# Squid expects the following traffic patterns:
1606#
1607# http_port: a plain HTTP request
1608# https_port: SSL/TLS handshake followed by an [encrypted] HTTP request
1609# ftp_port: a plain FTP command (no on_unsupported_protocol support yet!)
1610# CONNECT tunnel on http_port: same as https_port
1611# CONNECT tunnel on https_port: same as https_port
1612#
1613# Currently, this directive has effect on intercepted connections and
1614# bumped tunnels only. Other cases are not supported because Squid
1615# cannot know the intended destination of other traffic.
1616#
1617# For example:
1618# # define what Squid errors indicate receiving non-HTTP traffic:
1619# acl foreignProtocol squid_error ERR_PROTOCOL_UNKNOWN ERR_TOO_BIG
1620# # define what Squid errors indicate receiving nothing:
1621# acl serverTalksFirstProtocol squid_error ERR_REQUEST_START_TIMEOUT
1622# # tunnel everything that does not look like HTTP:
1623# on_unsupported_protocol tunnel foreignProtocol
1624# # tunnel if we think the client waits for the server to talk first:
1625# on_unsupported_protocol tunnel serverTalksFirstProtocol
1626# # in all other error cases, just send an HTTP "error page" response:
1627# on_unsupported_protocol respond all
1628#
1629# See also: squid_error ACL
1630#Default:
1631# Respond with an error message to unidentifiable traffic
1632
1633# NETWORK OPTIONS
1634# -----------------------------------------------------------------------------
1635
1636# TAG: http_port
1637# Usage: port [mode] [options]
1638# hostname:port [mode] [options]
1639# 1.2.3.4:port [mode] [options]
1640#
1641# The socket addresses where Squid will listen for HTTP client
1642# requests. You may specify multiple socket addresses.
1643# There are three forms: port alone, hostname with port, and
1644# IP address with port. If you specify a hostname or IP
1645# address, Squid binds the socket to that specific
1646# address. Most likely, you do not need to bind to a specific
1647# address, so you can use the port number alone.
1648#
1649# If you are running Squid in accelerator mode, you
1650# probably want to listen on port 80 also, or instead.
1651#
1652# The -a command line option may be used to specify additional
1653# port(s) where Squid listens for proxy request. Such ports will
1654# be plain proxy ports with no options.
1655#
1656# You may specify multiple socket addresses on multiple lines.
1657#
1658# Modes:
1659#
1660# intercept Support for IP-Layer NAT interception delivering
1661# traffic to this Squid port.
1662# NP: disables authentication on the port.
1663#
1664# tproxy Support Linux TPROXY (or BSD divert-to) with spoofing
1665# of outgoing connections using the client IP address.
1666# NP: disables authentication on the port.
1667#
1668# accel Accelerator / reverse proxy mode
1669#
1670# ssl-bump For each CONNECT request allowed by ssl_bump ACLs,
1671# establish secure connection with the client and with
1672# the server, decrypt HTTPS messages as they pass through
1673# Squid, and treat them as unencrypted HTTP messages,
1674# becoming the man-in-the-middle.
1675#
1676# The ssl_bump option is required to fully enable
1677# bumping of CONNECT requests.
1678#
1679# Omitting the mode flag causes default forward proxy mode to be used.
1680#
1681#
1682# Accelerator Mode Options:
1683#
1684# defaultsite=domainname
1685# What to use for the Host: header if it is not present
1686# in a request. Determines what site (not origin server)
1687# accelerators should consider the default.
1688#
1689# no-vhost Disable using HTTP/1.1 Host header for virtual domain support.
1690#
1691# protocol= Protocol to reconstruct accelerated and intercepted
1692# requests with. Defaults to HTTP/1.1 for http_port and
1693# HTTPS/1.1 for https_port.
1694# When an unsupported value is configured Squid will
1695# produce a FATAL error.
1696# Values: HTTP or HTTP/1.1, HTTPS or HTTPS/1.1
1697#
1698# vport Virtual host port support. Using the http_port number
1699# instead of the port passed on Host: headers.
1700#
1701# vport=NN Virtual host port support. Using the specified port
1702# number instead of the port passed on Host: headers.
1703#
1704# act-as-origin
1705# Act as if this Squid is the origin server.
1706# This currently means generate new Date: and Expires:
1707# headers on HIT instead of adding Age:.
1708#
1709# ignore-cc Ignore request Cache-Control headers.
1710#
1711# WARNING: This option violates HTTP specifications if
1712# used in non-accelerator setups.
1713#
1714# allow-direct Allow direct forwarding in accelerator mode. Normally
1715# accelerated requests are denied direct forwarding as if
1716# never_direct was used.
1717#
1718# WARNING: this option opens accelerator mode to security
1719# vulnerabilities usually only affecting in interception
1720# mode. Make sure to protect forwarding with suitable
1721# http_access rules when using this.
1722#
1723#
1724# SSL Bump Mode Options:
1725# In addition to these options ssl-bump requires TLS/SSL options.
1726#
1727# generate-host-certificates[=<on|off>]
1728# Dynamically create SSL server certificates for the
1729# destination hosts of bumped CONNECT requests.When
1730# enabled, the cert and key options are used to sign
1731# generated certificates. Otherwise generated
1732# certificate will be selfsigned.
1733# If there is a CA certificate lifetime of the generated
1734# certificate equals lifetime of the CA certificate. If
1735# generated certificate is selfsigned lifetime is three
1736# years.
1737# This option is enabled by default when ssl-bump is used.
1738# See the ssl-bump option above for more information.
1739#
1740# dynamic_cert_mem_cache_size=SIZE
1741# Approximate total RAM size spent on cached generated
1742# certificates. If set to zero, caching is disabled. The
1743# default value is 4MB.
1744#
1745# TLS / SSL Options:
1746#
1747# tls-cert= Path to file containing an X.509 certificate (PEM format)
1748# to be used in the TLS handshake ServerHello.
1749#
1750# If this certificate is constrained by KeyUsage TLS
1751# feature it must allow HTTP server usage, along with
1752# any additional restrictions imposed by your choice
1753# of options= settings.
1754#
1755# When OpenSSL is used this file may also contain a
1756# chain of intermediate CA certificates to send in the
1757# TLS handshake.
1758#
1759# When GnuTLS is used this option (and any paired
1760# tls-key= option) may be repeated to load multiple
1761# certificates for different domains.
1762#
1763# Also, when generate-host-certificates=on is configured
1764# the first tls-cert= option must be a CA certificate
1765# capable of signing the automatically generated
1766# certificates.
1767#
1768# tls-key= Path to a file containing private key file (PEM format)
1769# for the previous tls-cert= option.
1770#
1771# If tls-key= is not specified tls-cert= is assumed to
1772# reference a PEM file containing both the certificate
1773# and private key.
1774#
1775# cipher= Colon separated list of supported ciphers.
1776# NOTE: some ciphers such as EDH ciphers depend on
1777# additional settings. If those settings are
1778# omitted the ciphers may be silently ignored
1779# by the OpenSSL library.
1780#
1781# options= Various SSL implementation options. The most important
1782# being:
1783#
1784# NO_SSLv3 Disallow the use of SSLv3
1785#
1786# NO_TLSv1 Disallow the use of TLSv1.0
1787#
1788# NO_TLSv1_1 Disallow the use of TLSv1.1
1789#
1790# NO_TLSv1_2 Disallow the use of TLSv1.2
1791#
1792# SINGLE_DH_USE
1793# Always create a new key when using
1794# temporary/ephemeral DH key exchanges
1795#
1796# SINGLE_ECDH_USE
1797# Enable ephemeral ECDH key exchange.
1798# The adopted curve should be specified
1799# using the tls-dh option.
1800#
1801# NO_TICKET
1802# Disable use of RFC5077 session tickets.
1803# Some servers may have problems
1804# understanding the TLS extension due
1805# to ambiguous specification in RFC4507.
1806#
1807# ALL Enable various bug workarounds
1808# suggested as "harmless" by OpenSSL
1809# Be warned that this reduces SSL/TLS
1810# strength to some attacks.
1811#
1812# See the OpenSSL SSL_CTX_set_options documentation for a
1813# more complete list.
1814#
1815# clientca= File containing the list of CAs to use when
1816# requesting a client certificate.
1817#
1818# tls-cafile= PEM file containing CA certificates to use when verifying
1819# client certificates. If not configured clientca will be
1820# used. May be repeated to load multiple files.
1821#
1822# capath= Directory containing additional CA certificates
1823# and CRL lists to use when verifying client certificates.
1824# Requires OpenSSL or LibreSSL.
1825#
1826# crlfile= File of additional CRL lists to use when verifying
1827# the client certificate, in addition to CRLs stored in
1828# the capath. Implies VERIFY_CRL flag below.
1829#
1830# tls-dh=[curve:]file
1831# File containing DH parameters for temporary/ephemeral DH key
1832# exchanges, optionally prefixed by a curve for ephemeral ECDH
1833# key exchanges.
1834# See OpenSSL documentation for details on how to create the
1835# DH parameter file. Supported curves for ECDH can be listed
1836# using the "openssl ecparam -list_curves" command.
1837# WARNING: EDH and EECDH ciphers will be silently disabled if
1838# this option is not set.
1839#
1840# sslflags= Various flags modifying the use of SSL:
1841# DELAYED_AUTH
1842# Don't request client certificates
1843# immediately, but wait until acl processing
1844# requires a certificate (not yet implemented).
1845# NO_SESSION_REUSE
1846# Don't allow for session reuse. Each connection
1847# will result in a new SSL session.
1848# VERIFY_CRL
1849# Verify CRL lists when accepting client
1850# certificates.
1851# VERIFY_CRL_ALL
1852# Verify CRL lists for all certificates in the
1853# client certificate chain.
1854#
1855# tls-default-ca[=off]
1856# Whether to use the system Trusted CAs. Default is OFF.
1857#
1858# tls-no-npn Do not use the TLS NPN extension to advertise HTTP/1.1.
1859#
1860# sslcontext= SSL session ID context identifier.
1861#
1862# Other Options:
1863#
1864# connection-auth[=on|off]
1865# use connection-auth=off to tell Squid to prevent
1866# forwarding Microsoft connection oriented authentication
1867# (NTLM, Negotiate and Kerberos)
1868#
1869# disable-pmtu-discovery=
1870# Control Path-MTU discovery usage:
1871# off lets OS decide on what to do (default).
1872# transparent disable PMTU discovery when transparent
1873# support is enabled.
1874# always disable always PMTU discovery.
1875#
1876# In many setups of transparently intercepting proxies
1877# Path-MTU discovery can not work on traffic towards the
1878# clients. This is the case when the intercepting device
1879# does not fully track connections and fails to forward
1880# ICMP must fragment messages to the cache server. If you
1881# have such setup and experience that certain clients
1882# sporadically hang or never complete requests set
1883# disable-pmtu-discovery option to 'transparent'.
1884#
1885# name= Specifies a internal name for the port. Defaults to
1886# the port specification (port or addr:port)
1887#
1888# tcpkeepalive[=idle,interval,timeout]
1889# Enable TCP keepalive probes of idle connections.
1890# In seconds; idle is the initial time before TCP starts
1891# probing the connection, interval how often to probe, and
1892# timeout the time before giving up.
1893#
1894# require-proxy-header
1895# Require PROXY protocol version 1 or 2 connections.
1896# The proxy_protocol_access is required to whitelist
1897# downstream proxies which can be trusted.
1898#
1899# If you run Squid on a dual-homed machine with an internal
1900# and an external interface we recommend you to specify the
1901# internal address:port in http_port. This way Squid will only be
1902# visible on the internal address.
1903#
1904#
1905
1906# Squid normally listens to port 3128
1907http_port 3128
1908
1909# TAG: https_port
1910# Usage: [ip:]port [mode] tls-cert=certificate.pem [options]
1911#
1912# The socket address where Squid will listen for client requests made
1913# over TLS or SSL connections. Commonly referred to as HTTPS.
1914#
1915# This is most useful for situations where you are running squid in
1916# accelerator mode and you want to do the TLS work at the accelerator
1917# level.
1918#
1919# You may specify multiple socket addresses on multiple lines,
1920# each with their own certificate and/or options.
1921#
1922# The tls-cert= option is mandatory on HTTPS ports.
1923#
1924# See http_port for a list of modes and options.
1925#Default:
1926# none
1927
1928# TAG: ftp_port
1929# Enables Native FTP proxy by specifying the socket address where Squid
1930# listens for FTP client requests. See http_port directive for various
1931# ways to specify the listening address and mode.
1932#
1933# Usage: ftp_port address [mode] [options]
1934#
1935# WARNING: This is a new, experimental, complex feature that has seen
1936# limited production exposure. Some Squid modules (e.g., caching) do not
1937# currently work with native FTP proxying, and many features have not
1938# even been tested for compatibility. Test well before deploying!
1939#
1940# Native FTP proxying differs substantially from proxying HTTP requests
1941# with ftp:// URIs because Squid works as an FTP server and receives
1942# actual FTP commands (rather than HTTP requests with FTP URLs).
1943#
1944# Native FTP commands accepted at ftp_port are internally converted or
1945# wrapped into HTTP-like messages. The same happens to Native FTP
1946# responses received from FTP origin servers. Those HTTP-like messages
1947# are shoveled through regular access control and adaptation layers
1948# between the FTP client and the FTP origin server. This allows Squid to
1949# examine, adapt, block, and log FTP exchanges. Squid reuses most HTTP
1950# mechanisms when shoveling wrapped FTP messages. For example,
1951# http_access and adaptation_access directives are used.
1952#
1953# Modes:
1954#
1955# intercept Same as http_port intercept. The FTP origin address is
1956# determined based on the intended destination of the
1957# intercepted connection.
1958#
1959# tproxy Support Linux TPROXY for spoofing outgoing
1960# connections using the client IP address.
1961# NP: disables authentication and maybe IPv6 on the port.
1962#
1963# By default (i.e., without an explicit mode option), Squid extracts the
1964# FTP origin address from the login@origin parameter of the FTP USER
1965# command. Many popular FTP clients support such native FTP proxying.
1966#
1967# Options:
1968#
1969# name=token Specifies an internal name for the port. Defaults to
1970# the port address. Usable with myportname ACL.
1971#
1972# ftp-track-dirs
1973# Enables tracking of FTP directories by injecting extra
1974# PWD commands and adjusting Request-URI (in wrapping
1975# HTTP requests) to reflect the current FTP server
1976# directory. Tracking is disabled by default.
1977#
1978# protocol=FTP Protocol to reconstruct accelerated and intercepted
1979# requests with. Defaults to FTP. No other accepted
1980# values have been tested with. An unsupported value
1981# results in a FATAL error. Accepted values are FTP,
1982# HTTP (or HTTP/1.1), and HTTPS (or HTTPS/1.1).
1983#
1984# Other http_port modes and options that are not specific to HTTP and
1985# HTTPS may also work.
1986#Default:
1987# none
1988
1989# TAG: tcp_outgoing_tos
1990# Allows you to select a TOS/Diffserv value for packets outgoing
1991# on the server side, based on an ACL.
1992#
1993# tcp_outgoing_tos ds-field [!]aclname ...
1994#
1995# Example where normal_service_net uses the TOS value 0x00
1996# and good_service_net uses 0x20
1997#
1998# acl normal_service_net src 10.0.0.0/24
1999# acl good_service_net src 10.0.1.0/24
2000# tcp_outgoing_tos 0x00 normal_service_net
2001# tcp_outgoing_tos 0x20 good_service_net
2002#
2003# TOS/DSCP values really only have local significance - so you should
2004# know what you're specifying. For more information, see RFC2474,
2005# RFC2475, and RFC3260.
2006#
2007# The TOS/DSCP byte must be exactly that - a octet value 0 - 255, or
2008# "default" to use whatever default your host has.
2009# Note that only multiples of 4 are usable as the two rightmost bits have
2010# been redefined for use by ECN (RFC 3168 section 23.1).
2011# The squid parser will enforce this by masking away the ECN bits.
2012#
2013# Processing proceeds in the order specified, and stops at first fully
2014# matching line.
2015#
2016# Only fast ACLs are supported.
2017#Default:
2018# none
2019
2020# TAG: clientside_tos
2021# Allows you to select a TOS/DSCP value for packets being transmitted
2022# on the client-side, based on an ACL.
2023#
2024# clientside_tos ds-field [!]aclname ...
2025#
2026# Example where normal_service_net uses the TOS value 0x00
2027# and good_service_net uses 0x20
2028#
2029# acl normal_service_net src 10.0.0.0/24
2030# acl good_service_net src 10.0.1.0/24
2031# clientside_tos 0x00 normal_service_net
2032# clientside_tos 0x20 good_service_net
2033#
2034# Note: This feature is incompatible with qos_flows. Any TOS values set here
2035# will be overwritten by TOS values in qos_flows.
2036#
2037# The TOS/DSCP byte must be exactly that - a octet value 0 - 255, or
2038# "default" to use whatever default your host has.
2039# Note that only multiples of 4 are usable as the two rightmost bits have
2040# been redefined for use by ECN (RFC 3168 section 23.1).
2041# The squid parser will enforce this by masking away the ECN bits.
2042#
2043# This clause only supports fast acl types.
2044# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
2045#Default:
2046# none
2047
2048# TAG: tcp_outgoing_mark
2049# Note: This option is only available if Squid is rebuilt with the
2050# Packet MARK (Linux)
2051#
2052# Allows you to apply a Netfilter mark value to outgoing packets
2053# on the server side, based on an ACL.
2054#
2055# tcp_outgoing_mark mark-value [!]aclname ...
2056#
2057# Example where normal_service_net uses the mark value 0x00
2058# and good_service_net uses 0x20
2059#
2060# acl normal_service_net src 10.0.0.0/24
2061# acl good_service_net src 10.0.1.0/24
2062# tcp_outgoing_mark 0x00 normal_service_net
2063# tcp_outgoing_mark 0x20 good_service_net
2064#
2065# Only fast ACLs are supported.
2066#Default:
2067# none
2068
2069# TAG: clientside_mark
2070# Note: This option is only available if Squid is rebuilt with the
2071# Packet MARK (Linux)
2072#
2073# Allows you to apply a Netfilter mark value to packets being transmitted
2074# on the client-side, based on an ACL.
2075#
2076# clientside_mark mark-value [!]aclname ...
2077#
2078# Example where normal_service_net uses the mark value 0x00
2079# and good_service_net uses 0x20
2080#
2081# acl normal_service_net src 10.0.0.0/24
2082# acl good_service_net src 10.0.1.0/24
2083# clientside_mark 0x00 normal_service_net
2084# clientside_mark 0x20 good_service_net
2085#
2086# Note: This feature is incompatible with qos_flows. Any mark values set here
2087# will be overwritten by mark values in qos_flows.
2088#
2089# This clause only supports fast acl types.
2090# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
2091#Default:
2092# none
2093
2094# TAG: qos_flows
2095# Allows you to select a TOS/DSCP value to mark outgoing
2096# connections to the client, based on where the reply was sourced.
2097# For platforms using netfilter, allows you to set a netfilter mark
2098# value instead of, or in addition to, a TOS value.
2099#
2100# By default this functionality is disabled. To enable it with the default
2101# settings simply use "qos_flows mark" or "qos_flows tos". Default
2102# settings will result in the netfilter mark or TOS value being copied
2103# from the upstream connection to the client. Note that it is the connection
2104# CONNMARK value not the packet MARK value that is copied.
2105#
2106# It is not currently possible to copy the mark or TOS value from the
2107# client to the upstream connection request.
2108#
2109# TOS values really only have local significance - so you should
2110# know what you're specifying. For more information, see RFC2474,
2111# RFC2475, and RFC3260.
2112#
2113# The TOS/DSCP byte must be exactly that - a octet value 0 - 255.
2114# Note that only multiples of 4 are usable as the two rightmost bits have
2115# been redefined for use by ECN (RFC 3168 section 23.1).
2116# The squid parser will enforce this by masking away the ECN bits.
2117#
2118# Mark values can be any unsigned 32-bit integer value.
2119#
2120# This setting is configured by setting the following values:
2121#
2122# tos|mark Whether to set TOS or netfilter mark values
2123#
2124# local-hit=0xFF Value to mark local cache hits.
2125#
2126# sibling-hit=0xFF Value to mark hits from sibling peers.
2127#
2128# parent-hit=0xFF Value to mark hits from parent peers.
2129#
2130# miss=0xFF[/mask] Value to mark cache misses. Takes precedence
2131# over the preserve-miss feature (see below), unless
2132# mask is specified, in which case only the bits
2133# specified in the mask are written.
2134#
2135# The TOS variant of the following features are only possible on Linux
2136# and require your kernel to be patched with the TOS preserving ZPH
2137# patch, available from http://zph.bratcheda.org
2138# No patch is needed to preserve the netfilter mark, which will work
2139# with all variants of netfilter.
2140#
2141# disable-preserve-miss
2142# This option disables the preservation of the TOS or netfilter
2143# mark. By default, the existing TOS or netfilter mark value of
2144# the response coming from the remote server will be retained
2145# and masked with miss-mark.
2146# NOTE: in the case of a netfilter mark, the mark must be set on
2147# the connection (using the CONNMARK target) not on the packet
2148# (MARK target).
2149#
2150# miss-mask=0xFF
2151# Allows you to mask certain bits in the TOS or mark value
2152# received from the remote server, before copying the value to
2153# the TOS sent towards clients.
2154# Default for tos: 0xFF (TOS from server is not changed).
2155# Default for mark: 0xFFFFFFFF (mark from server is not changed).
2156#
2157# All of these features require the --enable-zph-qos compilation flag
2158# (enabled by default). Netfilter marking also requires the
2159# libnetfilter_conntrack libraries (--with-netfilter-conntrack) and
2160# libcap 2.09+ (--with-libcap).
2161#
2162#Default:
2163# none
2164
2165# TAG: tcp_outgoing_address
2166# Allows you to map requests to different outgoing IP addresses
2167# based on the username or source address of the user making
2168# the request.
2169#
2170# tcp_outgoing_address ipaddr [[!]aclname] ...
2171#
2172# For example;
2173# Forwarding clients with dedicated IPs for certain subnets.
2174#
2175# acl normal_service_net src 10.0.0.0/24
2176# acl good_service_net src 10.0.2.0/24
2177#
2178# tcp_outgoing_address 2001:db8::c001 good_service_net
2179# tcp_outgoing_address 10.1.0.2 good_service_net
2180#
2181# tcp_outgoing_address 2001:db8::beef normal_service_net
2182# tcp_outgoing_address 10.1.0.1 normal_service_net
2183#
2184# tcp_outgoing_address 2001:db8::1
2185# tcp_outgoing_address 10.1.0.3
2186#
2187# Processing proceeds in the order specified, and stops at first fully
2188# matching line.
2189#
2190# Squid will add an implicit IP version test to each line.
2191# Requests going to IPv4 websites will use the outgoing 10.1.0.* addresses.
2192# Requests going to IPv6 websites will use the outgoing 2001:db8:* addresses.
2193#
2194#
2195# NOTE: The use of this directive using client dependent ACLs is
2196# incompatible with the use of server side persistent connections. To
2197# ensure correct results it is best to set server_persistent_connections
2198# to off when using this directive in such configurations.
2199#
2200# NOTE: The use of this directive to set a local IP on outgoing TCP links
2201# is incompatible with using TPROXY to set client IP out outbound TCP links.
2202# When needing to contact peers use the no-tproxy cache_peer option and the
2203# client_dst_passthru directive re-enable normal forwarding such as this.
2204#
2205# This clause only supports fast acl types.
2206# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
2207#Default:
2208# Address selection is performed by the operating system.
2209
2210# TAG: host_verify_strict
2211# Regardless of this option setting, when dealing with intercepted
2212# traffic, Squid always verifies that the destination IP address matches
2213# the Host header domain or IP (called 'authority form URL').
2214#
2215# This enforcement is performed to satisfy a MUST-level requirement in
2216# RFC 2616 section 14.23: "The Host field value MUST represent the naming
2217# authority of the origin server or gateway given by the original URL".
2218#
2219# When set to ON:
2220# Squid always responds with an HTTP 409 (Conflict) error
2221# page and logs a security warning if there is no match.
2222#
2223# Squid verifies that the destination IP address matches
2224# the Host header for forward-proxy and reverse-proxy traffic
2225# as well. For those traffic types, Squid also enables the
2226# following checks, comparing the corresponding Host header
2227# and Request-URI components:
2228#
2229# * The host names (domain or IP) must be identical,
2230# but valueless or missing Host header disables all checks.
2231# For the two host names to match, both must be either IP
2232# or FQDN.
2233#
2234# * Port numbers must be identical, but if a port is missing
2235# the scheme-default port is assumed.
2236#
2237#
2238# When set to OFF (the default):
2239# Squid allows suspicious requests to continue but logs a
2240# security warning and blocks caching of the response.
2241#
2242# * Forward-proxy traffic is not checked at all.
2243#
2244# * Reverse-proxy traffic is not checked at all.
2245#
2246# * Intercepted traffic which passes verification is handled
2247# according to client_dst_passthru.
2248#
2249# * Intercepted requests which fail verification are sent
2250# to the client original destination instead of DIRECT.
2251# This overrides 'client_dst_passthru off'.
2252#
2253# For now suspicious intercepted CONNECT requests are always
2254# responded to with an HTTP 409 (Conflict) error page.
2255#
2256#
2257# SECURITY NOTE:
2258#
2259# As described in CVE-2009-0801 when the Host: header alone is used
2260# to determine the destination of a request it becomes trivial for
2261# malicious scripts on remote websites to bypass browser same-origin
2262# security policy and sandboxing protections.
2263#
2264# The cause of this is that such applets are allowed to perform their
2265# own HTTP stack, in which case the same-origin policy of the browser
2266# sandbox only verifies that the applet tries to contact the same IP
2267# as from where it was loaded at the IP level. The Host: header may
2268# be different from the connected IP and approved origin.
2269#
2270#Default:
2271# host_verify_strict off
2272
2273# TAG: client_dst_passthru
2274# With NAT or TPROXY intercepted traffic Squid may pass the request
2275# directly to the original client destination IP or seek a faster
2276# source using the HTTP Host header.
2277#
2278# Using Host to locate alternative servers can provide faster
2279# connectivity with a range of failure recovery options.
2280# But can also lead to connectivity trouble when the client and
2281# server are attempting stateful interactions unaware of the proxy.
2282#
2283# This option (on by default) prevents alternative DNS entries being
2284# located to send intercepted traffic DIRECT to an origin server.
2285# The clients original destination IP and port will be used instead.
2286#
2287# Regardless of this option setting, when dealing with intercepted
2288# traffic Squid will verify the Host: header and any traffic which
2289# fails Host verification will be treated as if this option were ON.
2290#
2291# see host_verify_strict for details on the verification process.
2292#Default:
2293# client_dst_passthru on
2294
2295# TLS OPTIONS
2296# -----------------------------------------------------------------------------
2297
2298# TAG: tls_outgoing_options
2299# disable Do not support https:// URLs.
2300#
2301# cert=/path/to/client/certificate
2302# A client X.509 certificate to use when connecting.
2303#
2304# key=/path/to/client/private_key
2305# The private key corresponding to the cert= above.
2306#
2307# If key= is not specified cert= is assumed to
2308# reference a PEM file containing both the certificate
2309# and private key.
2310#
2311# cipher=... The list of valid TLS ciphers to use.
2312#
2313# min-version=1.N
2314# The minimum TLS protocol version to permit.
2315# To control SSLv3 use the options= parameter.
2316# Supported Values: 1.0 (default), 1.1, 1.2
2317#
2318# options=... Specify various TLS/SSL implementation options.
2319#
2320# OpenSSL options most important are:
2321#
2322# NO_SSLv3 Disallow the use of SSLv3
2323#
2324# SINGLE_DH_USE
2325# Always create a new key when using
2326# temporary/ephemeral DH key exchanges
2327#
2328# NO_TICKET
2329# Disable use of RFC5077 session tickets.
2330# Some servers may have problems
2331# understanding the TLS extension due
2332# to ambiguous specification in RFC4507.
2333#
2334# ALL Enable various bug workarounds
2335# suggested as "harmless" by OpenSSL
2336# Be warned that this reduces SSL/TLS
2337# strength to some attacks.
2338#
2339# See the OpenSSL SSL_CTX_set_options documentation
2340# for a more complete list.
2341#
2342# GnuTLS options most important are:
2343#
2344# %NO_TICKETS
2345# Disable use of RFC5077 session tickets.
2346# Some servers may have problems
2347# understanding the TLS extension due
2348# to ambiguous specification in RFC4507.
2349#
2350# See the GnuTLS Priority Strings documentation
2351# for a more complete list.
2352# http://www.gnutls.org/manual/gnutls.html#Priority-Strings
2353#
2354#
2355# cafile= PEM file containing CA certificates to use when verifying
2356# the peer certificate. May be repeated to load multiple files.
2357#
2358# capath= A directory containing additional CA certificates to
2359# use when verifying the peer certificate.
2360# Requires OpenSSL or LibreSSL.
2361#
2362# crlfile=... A certificate revocation list file to use when
2363# verifying the peer certificate.
2364#
2365# flags=... Specify various flags modifying the TLS implementation:
2366#
2367# DONT_VERIFY_PEER
2368# Accept certificates even if they fail to
2369# verify.
2370# DONT_VERIFY_DOMAIN
2371# Don't verify the peer certificate
2372# matches the server name
2373#
2374# default-ca[=off]
2375# Whether to use the system Trusted CAs. Default is ON.
2376#
2377# domain= The peer name as advertised in its certificate.
2378# Used for verifying the correctness of the received peer
2379# certificate. If not specified the peer hostname will be
2380# used.
2381#Default:
2382# tls_outgoing_options min-version=1.0
2383
2384# SSL OPTIONS
2385# -----------------------------------------------------------------------------
2386
2387# TAG: ssl_unclean_shutdown
2388# Note: This option is only available if Squid is rebuilt with the
2389# --with-openssl
2390#
2391# Some browsers (especially MSIE) bugs out on SSL shutdown
2392# messages.
2393#Default:
2394# ssl_unclean_shutdown off
2395
2396# TAG: ssl_engine
2397# Note: This option is only available if Squid is rebuilt with the
2398# --with-openssl
2399#
2400# The OpenSSL engine to use. You will need to set this if you
2401# would like to use hardware SSL acceleration for example.
2402#Default:
2403# none
2404
2405# TAG: sslproxy_session_ttl
2406# Note: This option is only available if Squid is rebuilt with the
2407# --with-openssl
2408#
2409# Sets the timeout value for SSL sessions
2410#Default:
2411# sslproxy_session_ttl 300
2412
2413# TAG: sslproxy_session_cache_size
2414# Note: This option is only available if Squid is rebuilt with the
2415# --with-openssl
2416#
2417# Sets the cache size to use for ssl session
2418#Default:
2419# sslproxy_session_cache_size 2 MB
2420
2421# TAG: sslproxy_foreign_intermediate_certs
2422# Note: This option is only available if Squid is rebuilt with the
2423# --with-openssl
2424#
2425# Many origin servers fail to send their full server certificate
2426# chain for verification, assuming the client already has or can
2427# easily locate any missing intermediate certificates.
2428#
2429# Squid uses the certificates from the specified file to fill in
2430# these missing chains when trying to validate origin server
2431# certificate chains.
2432#
2433# The file is expected to contain zero or more PEM-encoded
2434# intermediate certificates. These certificates are not treated
2435# as trusted root certificates, and any self-signed certificate in
2436# this file will be ignored.
2437#Default:
2438# none
2439
2440# TAG: sslproxy_cert_sign_hash
2441# Note: This option is only available if Squid is rebuilt with the
2442# --with-openssl
2443#
2444# Sets the hashing algorithm to use when signing generated certificates.
2445# Valid algorithm names depend on the OpenSSL library used. The following
2446# names are usually available: sha1, sha256, sha512, and md5. Please see
2447# your OpenSSL library manual for the available hashes. By default, Squids
2448# that support this option use sha256 hashes.
2449#
2450# Squid does not forcefully purge cached certificates that were generated
2451# with an algorithm other than the currently configured one. They remain
2452# in the cache, subject to the regular cache eviction policy, and become
2453# useful if the algorithm changes again.
2454#Default:
2455# none
2456
2457# TAG: ssl_bump
2458# Note: This option is only available if Squid is rebuilt with the
2459# --with-openssl
2460#
2461# This option is consulted when a CONNECT request is received on
2462# an http_port (or a new connection is intercepted at an
2463# https_port), provided that port was configured with an ssl-bump
2464# flag. The subsequent data on the connection is either treated as
2465# HTTPS and decrypted OR tunneled at TCP level without decryption,
2466# depending on the first matching bumping "action".
2467#
2468# ssl_bump <action> [!]acl ...
2469#
2470# The following bumping actions are currently supported:
2471#
2472# splice
2473# Become a TCP tunnel without decrypting proxied traffic.
2474# This is the default action.
2475#
2476# bump
2477# When used on step SslBump1, establishes a secure connection
2478# with the client first, then connect to the server.
2479# When used on step SslBump2 or SslBump3, establishes a secure
2480# connection with the server and, using a mimicked server
2481# certificate, with the client.
2482#
2483# peek
2484# Receive client (step SslBump1) or server (step SslBump2)
2485# certificate while preserving the possibility of splicing the
2486# connection. Peeking at the server certificate (during step 2)
2487# usually precludes bumping of the connection at step 3.
2488#
2489# stare
2490# Receive client (step SslBump1) or server (step SslBump2)
2491# certificate while preserving the possibility of bumping the
2492# connection. Staring at the server certificate (during step 2)
2493# usually precludes splicing of the connection at step 3.
2494#
2495# terminate
2496# Close client and server connections.
2497#
2498# Backward compatibility actions available at step SslBump1:
2499#
2500# client-first
2501# Bump the connection. Establish a secure connection with the
2502# client first, then connect to the server. This old mode does
2503# not allow Squid to mimic server SSL certificate and does not
2504# work with intercepted SSL connections.
2505#
2506# server-first
2507# Bump the connection. Establish a secure connection with the
2508# server first, then establish a secure connection with the
2509# client, using a mimicked server certificate. Works with both
2510# CONNECT requests and intercepted SSL connections, but does
2511# not allow to make decisions based on SSL handshake info.
2512#
2513# peek-and-splice
2514# Decide whether to bump or splice the connection based on
2515# client-to-squid and server-to-squid SSL hello messages.
2516# XXX: Remove.
2517#
2518# none
2519# Same as the "splice" action.
2520#
2521# All ssl_bump rules are evaluated at each of the supported bumping
2522# steps. Rules with actions that are impossible at the current step are
2523# ignored. The first matching ssl_bump action wins and is applied at the
2524# end of the current step. If no rules match, the splice action is used.
2525# See the at_step ACL for a list of the supported SslBump steps.
2526#
2527# This clause supports both fast and slow acl types.
2528# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
2529#
2530# See also: http_port ssl-bump, https_port ssl-bump, and acl at_step.
2531#
2532#
2533# # Example: Bump all TLS connections except those originating from
2534# # localhost or those going to example.com.
2535#
2536# acl broken_sites ssl::server_name .example.com
2537# ssl_bump splice localhost
2538# ssl_bump splice broken_sites
2539# ssl_bump bump all
2540#Default:
2541# Become a TCP tunnel without decrypting proxied traffic.
2542
2543# TAG: sslproxy_cert_error
2544# Note: This option is only available if Squid is rebuilt with the
2545# --with-openssl
2546#
2547# Use this ACL to bypass server certificate validation errors.
2548#
2549# For example, the following lines will bypass all validation errors
2550# when talking to servers for example.com. All other
2551# validation errors will result in ERR_SECURE_CONNECT_FAIL error.
2552#
2553# acl BrokenButTrustedServers dstdomain example.com
2554# sslproxy_cert_error allow BrokenButTrustedServers
2555# sslproxy_cert_error deny all
2556#
2557# This clause only supports fast acl types.
2558# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
2559# Using slow acl types may result in server crashes
2560#
2561# Without this option, all server certificate validation errors
2562# terminate the transaction to protect Squid and the client.
2563#
2564# SQUID_X509_V_ERR_INFINITE_VALIDATION error cannot be bypassed
2565# but should not happen unless your OpenSSL library is buggy.
2566#
2567# SECURITY WARNING:
2568# Bypassing validation errors is dangerous because an
2569# error usually implies that the server cannot be trusted
2570# and the connection may be insecure.
2571#
2572# See also: sslproxy_flags and DONT_VERIFY_PEER.
2573#Default:
2574# Server certificate errors terminate the transaction.
2575
2576# TAG: sslproxy_cert_sign
2577# Note: This option is only available if Squid is rebuilt with the
2578# --with-openssl
2579#
2580#
2581# sslproxy_cert_sign <signing algorithm> acl ...
2582#
2583# The following certificate signing algorithms are supported:
2584#
2585# signTrusted
2586# Sign using the configured CA certificate which is usually
2587# placed in and trusted by end-user browsers. This is the
2588# default for trusted origin server certificates.
2589#
2590# signUntrusted
2591# Sign to guarantee an X509_V_ERR_CERT_UNTRUSTED browser error.
2592# This is the default for untrusted origin server certificates
2593# that are not self-signed (see ssl::certUntrusted).
2594#
2595# signSelf
2596# Sign using a self-signed certificate with the right CN to
2597# generate a X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT error in the
2598# browser. This is the default for self-signed origin server
2599# certificates (see ssl::certSelfSigned).
2600#
2601# This clause only supports fast acl types.
2602#
2603# When sslproxy_cert_sign acl(s) match, Squid uses the corresponding
2604# signing algorithm to generate the certificate and ignores all
2605# subsequent sslproxy_cert_sign options (the first match wins). If no
2606# acl(s) match, the default signing algorithm is determined by errors
2607# detected when obtaining and validating the origin server certificate.
2608#
2609# WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can
2610# be used with sslproxy_cert_adapt, but if and only if Squid is bumping a
2611# CONNECT request that carries a domain name. In all other cases (CONNECT
2612# to an IP address or an intercepted SSL connection), Squid cannot detect
2613# the domain mismatch at certificate generation time when
2614# bump-server-first is used.
2615#Default:
2616# none
2617
2618# TAG: sslproxy_cert_adapt
2619# Note: This option is only available if Squid is rebuilt with the
2620# --with-openssl
2621#
2622#
2623# sslproxy_cert_adapt <adaptation algorithm> acl ...
2624#
2625# The following certificate adaptation algorithms are supported:
2626#
2627# setValidAfter
2628# Sets the "Not After" property to the "Not After" property of
2629# the CA certificate used to sign generated certificates.
2630#
2631# setValidBefore
2632# Sets the "Not Before" property to the "Not Before" property of
2633# the CA certificate used to sign generated certificates.
2634#
2635# setCommonName or setCommonName{CN}
2636# Sets Subject.CN property to the host name specified as a
2637# CN parameter or, if no explicit CN parameter was specified,
2638# extracted from the CONNECT request. It is a misconfiguration
2639# to use setCommonName without an explicit parameter for
2640# intercepted or tproxied SSL connections.
2641#
2642# This clause only supports fast acl types.
2643#
2644# Squid first groups sslproxy_cert_adapt options by adaptation algorithm.
2645# Within a group, when sslproxy_cert_adapt acl(s) match, Squid uses the
2646# corresponding adaptation algorithm to generate the certificate and
2647# ignores all subsequent sslproxy_cert_adapt options in that algorithm's
2648# group (i.e., the first match wins within each algorithm group). If no
2649# acl(s) match, the default mimicking action takes place.
2650#
2651# WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can
2652# be used with sslproxy_cert_adapt, but if and only if Squid is bumping a
2653# CONNECT request that carries a domain name. In all other cases (CONNECT
2654# to an IP address or an intercepted SSL connection), Squid cannot detect
2655# the domain mismatch at certificate generation time when
2656# bump-server-first is used.
2657#Default:
2658# none
2659
2660# TAG: sslpassword_program
2661# Note: This option is only available if Squid is rebuilt with the
2662# --with-openssl
2663#
2664# Specify a program used for entering SSL key passphrases
2665# when using encrypted SSL certificate keys. If not specified
2666# keys must either be unencrypted, or Squid started with the -N
2667# option to allow it to query interactively for the passphrase.
2668#
2669# The key file name is given as argument to the program allowing
2670# selection of the right password if you have multiple encrypted
2671# keys.
2672#Default:
2673# none
2674
2675# OPTIONS RELATING TO EXTERNAL SSL_CRTD
2676# -----------------------------------------------------------------------------
2677
2678# TAG: sslcrtd_program
2679# Note: This option is only available if Squid is rebuilt with the
2680# --enable-ssl-crtd
2681#
2682# Specify the location and options of the executable for certificate
2683# generator.
2684#
2685# /usr/lib/squid/security_file_certgen program can use a disk cache to improve response
2686# times on repeated requests. To enable caching, specify -s and -M
2687# parameters. If those parameters are not given, the program generates
2688# a new certificate on every request.
2689#
2690# For more information use:
2691# /usr/lib/squid/security_file_certgen -h
2692#Default:
2693# sslcrtd_program /usr/lib/squid/security_file_certgen -s /var/spool/squid/ssl_db -M 4MB
2694
2695# TAG: sslcrtd_children
2696# Note: This option is only available if Squid is rebuilt with the
2697# --enable-ssl-crtd
2698#
2699# Specifies the maximum number of certificate generation processes that
2700# Squid may spawn (numberofchildren) and several related options. Using
2701# too few of these helper processes (a.k.a. "helpers") creates request
2702# queues. Using too many helpers wastes your system resources. Squid
2703# does not support spawning more than 32 helpers.
2704#
2705# Usage: numberofchildren [option]...
2706#
2707# The startup= and idle= options allow some measure of skew in your
2708# tuning.
2709#
2710# startup=N
2711#
2712# Sets the minimum number of processes to spawn when Squid
2713# starts or reconfigures. When set to zero the first request will
2714# cause spawning of the first child process to handle it.
2715#
2716# Starting too few children temporary slows Squid under load while it
2717# tries to spawn enough additional processes to cope with traffic.
2718#
2719# idle=N
2720#
2721# Sets a minimum of how many processes Squid is to try and keep available
2722# at all times. When traffic begins to rise above what the existing
2723# processes can handle this many more will be spawned up to the maximum
2724# configured. A minimum setting of 1 is required.
2725#
2726# queue-size=N
2727#
2728# Sets the maximum number of queued requests. A request is queued when
2729# no existing child is idle and no new child can be started due to
2730# numberofchildren limit. If the queued requests exceed queue size for
2731# more than 3 minutes squid aborts its operation. The default value is
2732# set to 2*numberofchildren.
2733#
2734# You must have at least one ssl_crtd process.
2735#Default:
2736# sslcrtd_children 32 startup=5 idle=1
2737
2738# TAG: sslcrtvalidator_program
2739# Note: This option is only available if Squid is rebuilt with the
2740# --with-openssl
2741#
2742# Specify the location and options of the executable for ssl_crt_validator
2743# process.
2744#
2745# Usage: sslcrtvalidator_program [ttl=n] [cache=n] path ...
2746#
2747# Options:
2748# ttl=n TTL in seconds for cached results. The default is 60 secs
2749# cache=n limit the result cache size. The default value is 2048
2750#Default:
2751# none
2752
2753# TAG: sslcrtvalidator_children
2754# Note: This option is only available if Squid is rebuilt with the
2755# --with-openssl
2756#
2757# Specifies the maximum number of certificate validation processes that
2758# Squid may spawn (numberofchildren) and several related options. Using
2759# too few of these helper processes (a.k.a. "helpers") creates request
2760# queues. Using too many helpers wastes your system resources. Squid
2761# does not support spawning more than 32 helpers.
2762#
2763# Usage: numberofchildren [option]...
2764#
2765# The startup= and idle= options allow some measure of skew in your
2766# tuning.
2767#
2768# startup=N
2769#
2770# Sets the minimum number of processes to spawn when Squid
2771# starts or reconfigures. When set to zero the first request will
2772# cause spawning of the first child process to handle it.
2773#
2774# Starting too few children temporary slows Squid under load while it
2775# tries to spawn enough additional processes to cope with traffic.
2776#
2777# idle=N
2778#
2779# Sets a minimum of how many processes Squid is to try and keep available
2780# at all times. When traffic begins to rise above what the existing
2781# processes can handle this many more will be spawned up to the maximum
2782# configured. A minimum setting of 1 is required.
2783#
2784# concurrency=
2785#
2786# The number of requests each certificate validator helper can handle in
2787# parallel. A value of 0 indicates the certficate validator does not
2788# support concurrency. Defaults to 1.
2789#
2790# When this directive is set to a value >= 1 then the protocol
2791# used to communicate with the helper is modified to include
2792# a request ID in front of the request/response. The request
2793# ID from the request must be echoed back with the response
2794# to that request.
2795#
2796# queue-size=N
2797#
2798# Sets the maximum number of queued requests. A request is queued when
2799# no existing child can accept it due to concurrency limit and no new
2800# child can be started due to numberofchildren limit. If the queued
2801# requests exceed queue size for more than 3 minutes squid aborts its
2802# operation. The default value is set to 2*numberofchildren.
2803#
2804# You must have at least one ssl_crt_validator process.
2805#Default:
2806# sslcrtvalidator_children 32 startup=5 idle=1 concurrency=1
2807
2808# OPTIONS WHICH AFFECT THE NEIGHBOR SELECTION ALGORITHM
2809# -----------------------------------------------------------------------------
2810
2811# TAG: cache_peer
2812# To specify other caches in a hierarchy, use the format:
2813#
2814# cache_peer hostname type http-port icp-port [options]
2815#
2816# For example,
2817#
2818# # proxy icp
2819# # hostname type port port options
2820# # -------------------- -------- ----- ----- -----------
2821# cache_peer parent.foo.net parent 3128 3130 default
2822# cache_peer sib1.foo.net sibling 3128 3130 proxy-only
2823# cache_peer sib2.foo.net sibling 3128 3130 proxy-only
2824# cache_peer example.com parent 80 0 default
2825# cache_peer cdn.example.com sibling 3128 0
2826#
2827# type: either 'parent', 'sibling', or 'multicast'.
2828#
2829# proxy-port: The port number where the peer accept HTTP requests.
2830# For other Squid proxies this is usually 3128
2831# For web servers this is usually 80
2832#
2833# icp-port: Used for querying neighbor caches about objects.
2834# Set to 0 if the peer does not support ICP or HTCP.
2835# See ICP and HTCP options below for additional details.
2836#
2837#
2838# ==== ICP OPTIONS ====
2839#
2840# You MUST also set icp_port and icp_access explicitly when using these options.
2841# The defaults will prevent peer traffic using ICP.
2842#
2843#
2844# no-query Disable ICP queries to this neighbor.
2845#
2846# multicast-responder
2847# Indicates the named peer is a member of a multicast group.
2848# ICP queries will not be sent directly to the peer, but ICP
2849# replies will be accepted from it.
2850#
2851# closest-only Indicates that, for ICP_OP_MISS replies, we'll only forward
2852# CLOSEST_PARENT_MISSes and never FIRST_PARENT_MISSes.
2853#
2854# background-ping
2855# To only send ICP queries to this neighbor infrequently.
2856# This is used to keep the neighbor round trip time updated
2857# and is usually used in conjunction with weighted-round-robin.
2858#
2859#
2860# ==== HTCP OPTIONS ====
2861#
2862# You MUST also set htcp_port and htcp_access explicitly when using these options.
2863# The defaults will prevent peer traffic using HTCP.
2864#
2865#
2866# htcp Send HTCP, instead of ICP, queries to the neighbor.
2867# You probably also want to set the "icp-port" to 4827
2868# instead of 3130. This directive accepts a comma separated
2869# list of options described below.
2870#
2871# htcp=oldsquid Send HTCP to old Squid versions (2.5 or earlier).
2872#
2873# htcp=no-clr Send HTCP to the neighbor but without
2874# sending any CLR requests. This cannot be used with
2875# only-clr.
2876#
2877# htcp=only-clr Send HTCP to the neighbor but ONLY CLR requests.
2878# This cannot be used with no-clr.
2879#
2880# htcp=no-purge-clr
2881# Send HTCP to the neighbor including CLRs but only when
2882# they do not result from PURGE requests.
2883#
2884# htcp=forward-clr
2885# Forward any HTCP CLR requests this proxy receives to the peer.
2886#
2887#
2888# ==== PEER SELECTION METHODS ====
2889#
2890# The default peer selection method is ICP, with the first responding peer
2891# being used as source. These options can be used for better load balancing.
2892#
2893#
2894# default This is a parent cache which can be used as a "last-resort"
2895# if a peer cannot be located by any of the peer-selection methods.
2896# If specified more than once, only the first is used.
2897#
2898# round-robin Load-Balance parents which should be used in a round-robin
2899# fashion in the absence of any ICP queries.
2900# weight=N can be used to add bias.
2901#
2902# weighted-round-robin
2903# Load-Balance parents which should be used in a round-robin
2904# fashion with the frequency of each parent being based on the
2905# round trip time. Closer parents are used more often.
2906# Usually used for background-ping parents.
2907# weight=N can be used to add bias.
2908#
2909# carp Load-Balance parents which should be used as a CARP array.
2910# The requests will be distributed among the parents based on the
2911# CARP load balancing hash function based on their weight.
2912#
2913# userhash Load-balance parents based on the client proxy_auth or ident username.
2914#
2915# sourcehash Load-balance parents based on the client source IP.
2916#
2917# multicast-siblings
2918# To be used only for cache peers of type "multicast".
2919# ALL members of this multicast group have "sibling"
2920# relationship with it, not "parent". This is to a multicast
2921# group when the requested object would be fetched only from
2922# a "parent" cache, anyway. It's useful, e.g., when
2923# configuring a pool of redundant Squid proxies, being
2924# members of the same multicast group.
2925#
2926#
2927# ==== PEER SELECTION OPTIONS ====
2928#
2929# weight=N use to affect the selection of a peer during any weighted
2930# peer-selection mechanisms.
2931# The weight must be an integer; default is 1,
2932# larger weights are favored more.
2933# This option does not affect parent selection if a peering
2934# protocol is not in use.
2935#
2936# basetime=N Specify a base amount to be subtracted from round trip
2937# times of parents.
2938# It is subtracted before division by weight in calculating
2939# which parent to fectch from. If the rtt is less than the
2940# base time the rtt is set to a minimal value.
2941#
2942# ttl=N Specify a TTL to use when sending multicast ICP queries
2943# to this address.
2944# Only useful when sending to a multicast group.
2945# Because we don't accept ICP replies from random
2946# hosts, you must configure other group members as
2947# peers with the 'multicast-responder' option.
2948#
2949# no-delay To prevent access to this neighbor from influencing the
2950# delay pools.
2951#
2952# digest-url=URL Tell Squid to fetch the cache digest (if digests are
2953# enabled) for this host from the specified URL rather
2954# than the Squid default location.
2955#
2956#
2957# ==== CARP OPTIONS ====
2958#
2959# carp-key=key-specification
2960# use a different key than the full URL to hash against the peer.
2961# the key-specification is a comma-separated list of the keywords
2962# scheme, host, port, path, params
2963# Order is not important.
2964#
2965# ==== ACCELERATOR / REVERSE-PROXY OPTIONS ====
2966#
2967# originserver Causes this parent to be contacted as an origin server.
2968# Meant to be used in accelerator setups when the peer
2969# is a web server.
2970#
2971# forceddomain=name
2972# Set the Host header of requests forwarded to this peer.
2973# Useful in accelerator setups where the server (peer)
2974# expects a certain domain name but clients may request
2975# others. ie example.com or www.example.com
2976#
2977# no-digest Disable request of cache digests.
2978#
2979# no-netdb-exchange
2980# Disables requesting ICMP RTT database (NetDB).
2981#
2982#
2983# ==== AUTHENTICATION OPTIONS ====
2984#
2985# login=user:password
2986# If this is a personal/workgroup proxy and your parent
2987# requires proxy authentication.
2988#
2989# Note: The string can include URL escapes (i.e. %20 for
2990# spaces). This also means % must be written as %%.
2991#
2992# login=PASSTHRU
2993# Send login details received from client to this peer.
2994# Both Proxy- and WWW-Authorization headers are passed
2995# without alteration to the peer.
2996# Authentication is not required by Squid for this to work.
2997#
2998# Note: This will pass any form of authentication but
2999# only Basic auth will work through a proxy unless the
3000# connection-auth options are also used.
3001#
3002# login=PASS Send login details received from client to this peer.
3003# Authentication is not required by this option.
3004#
3005# If there are no client-provided authentication headers
3006# to pass on, but username and password are available
3007# from an external ACL user= and password= result tags
3008# they may be sent instead.
3009#
3010# Note: To combine this with proxy_auth both proxies must
3011# share the same user database as HTTP only allows for
3012# a single login (one for proxy, one for origin server).
3013# Also be warned this will expose your users proxy
3014# password to the peer. USE WITH CAUTION
3015#
3016# login=*:password
3017# Send the username to the upstream cache, but with a
3018# fixed password. This is meant to be used when the peer
3019# is in another administrative domain, but it is still
3020# needed to identify each user.
3021# The star can optionally be followed by some extra
3022# information which is added to the username. This can
3023# be used to identify this proxy to the peer, similar to
3024# the login=username:password option above.
3025#
3026# login=NEGOTIATE
3027# If this is a personal/workgroup proxy and your parent
3028# requires a secure proxy authentication.
3029# The first principal from the default keytab or defined by
3030# the environment variable KRB5_KTNAME will be used.
3031#
3032# WARNING: The connection may transmit requests from multiple
3033# clients. Negotiate often assumes end-to-end authentication
3034# and a single-client. Which is not strictly true here.
3035#
3036# login=NEGOTIATE:principal_name
3037# If this is a personal/workgroup proxy and your parent
3038# requires a secure proxy authentication.
3039# The principal principal_name from the default keytab or
3040# defined by the environment variable KRB5_KTNAME will be
3041# used.
3042#
3043# WARNING: The connection may transmit requests from multiple
3044# clients. Negotiate often assumes end-to-end authentication
3045# and a single-client. Which is not strictly true here.
3046#
3047# connection-auth=on|off
3048# Tell Squid that this peer does or not support Microsoft
3049# connection oriented authentication, and any such
3050# challenges received from there should be ignored.
3051# Default is auto to automatically determine the status
3052# of the peer.
3053#
3054# auth-no-keytab
3055# Do not use a keytab to authenticate to a peer when
3056# login=NEGOTIATE is specified. Let the GSSAPI
3057# implementation determine which already existing
3058# credentials cache to use instead.
3059#
3060#
3061# ==== SSL / HTTPS / TLS OPTIONS ====
3062#
3063# tls Encrypt connections to this peer with TLS.
3064#
3065# sslcert=/path/to/ssl/certificate
3066# A client X.509 certificate to use when connecting to
3067# this peer.
3068#
3069# sslkey=/path/to/ssl/key
3070# The private key corresponding to sslcert above.
3071#
3072# If sslkey= is not specified sslcert= is assumed to
3073# reference a PEM file containing both the certificate
3074# and private key.
3075#
3076# sslcipher=... The list of valid SSL ciphers to use when connecting
3077# to this peer.
3078#
3079# tls-min-version=1.N
3080# The minimum TLS protocol version to permit. To control
3081# SSLv3 use the tls-options= parameter.
3082# Supported Values: 1.0 (default), 1.1, 1.2
3083#
3084# tls-options=... Specify various TLS implementation options.
3085#
3086# OpenSSL options most important are:
3087#
3088# NO_SSLv3 Disallow the use of SSLv3
3089#
3090# SINGLE_DH_USE
3091# Always create a new key when using
3092# temporary/ephemeral DH key exchanges
3093#
3094# NO_TICKET
3095# Disable use of RFC5077 session tickets.
3096# Some servers may have problems
3097# understanding the TLS extension due
3098# to ambiguous specification in RFC4507.
3099#
3100# ALL Enable various bug workarounds
3101# suggested as "harmless" by OpenSSL
3102# Be warned that this reduces SSL/TLS
3103# strength to some attacks.
3104#
3105# See the OpenSSL SSL_CTX_set_options documentation for a
3106# more complete list.
3107#
3108# GnuTLS options most important are:
3109#
3110# %NO_TICKETS
3111# Disable use of RFC5077 session tickets.
3112# Some servers may have problems
3113# understanding the TLS extension due
3114# to ambiguous specification in RFC4507.
3115#
3116# See the GnuTLS Priority Strings documentation
3117# for a more complete list.
3118# http://www.gnutls.org/manual/gnutls.html#Priority-Strings
3119#
3120# tls-cafile= PEM file containing CA certificates to use when verifying
3121# the peer certificate. May be repeated to load multiple files.
3122#
3123# sslcapath=... A directory containing additional CA certificates to
3124# use when verifying the peer certificate.
3125# Requires OpenSSL or LibreSSL.
3126#
3127# sslcrlfile=... A certificate revocation list file to use when
3128# verifying the peer certificate.
3129#
3130# sslflags=... Specify various flags modifying the SSL implementation:
3131#
3132# DONT_VERIFY_PEER
3133# Accept certificates even if they fail to
3134# verify.
3135#
3136# DONT_VERIFY_DOMAIN
3137# Don't verify the peer certificate
3138# matches the server name
3139#
3140# ssldomain= The peer name as advertised in it's certificate.
3141# Used for verifying the correctness of the received peer
3142# certificate. If not specified the peer hostname will be
3143# used.
3144#
3145# front-end-https[=off|on|auto]
3146# Enable the "Front-End-Https: On" header needed when
3147# using Squid as a SSL frontend in front of Microsoft OWA.
3148# See MS KB document Q307347 for details on this header.
3149# If set to auto the header will only be added if the
3150# request is forwarded as a https:// URL.
3151#
3152# tls-default-ca[=off]
3153# Whether to use the system Trusted CAs. Default is ON.
3154#
3155# tls-no-npn Do not use the TLS NPN extension to advertise HTTP/1.1.
3156#
3157# ==== GENERAL OPTIONS ====
3158#
3159# connect-timeout=N
3160# A peer-specific connect timeout.
3161# Also see the peer_connect_timeout directive.
3162#
3163# connect-fail-limit=N
3164# How many times connecting to a peer must fail before
3165# it is marked as down. Standby connection failures
3166# count towards this limit. Default is 10.
3167#
3168# allow-miss Disable Squid's use of only-if-cached when forwarding
3169# requests to siblings. This is primarily useful when
3170# icp_hit_stale is used by the sibling. Excessive use
3171# of this option may result in forwarding loops. One way
3172# to prevent peering loops when using this option, is to
3173# deny cache peer usage on requests from a peer:
3174# acl fromPeer ...
3175# cache_peer_access peerName deny fromPeer
3176#
3177# max-conn=N Limit the number of concurrent connections the Squid
3178# may open to this peer, including already opened idle
3179# and standby connections. There is no peer-specific
3180# connection limit by default.
3181#
3182# A peer exceeding the limit is not used for new
3183# requests unless a standby connection is available.
3184#
3185# max-conn currently works poorly with idle persistent
3186# connections: When a peer reaches its max-conn limit,
3187# and there are idle persistent connections to the peer,
3188# the peer may not be selected because the limiting code
3189# does not know whether Squid can reuse those idle
3190# connections.
3191#
3192# standby=N Maintain a pool of N "hot standby" connections to an
3193# UP peer, available for requests when no idle
3194# persistent connection is available (or safe) to use.
3195# By default and with zero N, no such pool is maintained.
3196# N must not exceed the max-conn limit (if any).
3197#
3198# At start or after reconfiguration, Squid opens new TCP
3199# standby connections until there are N connections
3200# available and then replenishes the standby pool as
3201# opened connections are used up for requests. A used
3202# connection never goes back to the standby pool, but
3203# may go to the regular idle persistent connection pool
3204# shared by all peers and origin servers.
3205#
3206# Squid never opens multiple new standby connections
3207# concurrently. This one-at-a-time approach minimizes
3208# flooding-like effect on peers. Furthermore, just a few
3209# standby connections should be sufficient in most cases
3210# to supply most new requests with a ready-to-use
3211# connection.
3212#
3213# Standby connections obey server_idle_pconn_timeout.
3214# For the feature to work as intended, the peer must be
3215# configured to accept and keep them open longer than
3216# the idle timeout at the connecting Squid, to minimize
3217# race conditions typical to idle used persistent
3218# connections. Default request_timeout and
3219# server_idle_pconn_timeout values ensure such a
3220# configuration.
3221#
3222# name=xxx Unique name for the peer.
3223# Required if you have multiple peers on the same host
3224# but different ports.
3225# This name can be used in cache_peer_access and similar
3226# directives to identify the peer.
3227# Can be used by outgoing access controls through the
3228# peername ACL type.
3229#
3230# no-tproxy Do not use the client-spoof TPROXY support when forwarding
3231# requests to this peer. Use normal address selection instead.
3232# This overrides the spoof_client_ip ACL.
3233#
3234# proxy-only objects fetched from the peer will not be stored locally.
3235#
3236#Default:
3237# none
3238
3239# TAG: cache_peer_access
3240# Restricts usage of cache_peer proxies.
3241#
3242# Usage:
3243# cache_peer_access peer-name allow|deny [!]aclname ...
3244#
3245# For the required peer-name parameter, use either the value of the
3246# cache_peer name=value parameter or, if name=value is missing, the
3247# cache_peer hostname parameter.
3248#
3249# This directive narrows down the selection of peering candidates, but
3250# does not determine the order in which the selected candidates are
3251# contacted. That order is determined by the peer selection algorithms
3252# (see PEER SELECTION sections in the cache_peer documentation).
3253#
3254# If a deny rule matches, the corresponding peer will not be contacted
3255# for the current transaction -- Squid will not send ICP queries and
3256# will not forward HTTP requests to that peer. An allow match leaves
3257# the corresponding peer in the selection. The first match for a given
3258# peer wins for that peer.
3259#
3260# The relative order of cache_peer_access directives for the same peer
3261# matters. The relative order of any two cache_peer_access directives
3262# for different peers does not matter. To ease interpretation, it is a
3263# good idea to group cache_peer_access directives for the same peer
3264# together.
3265#
3266# A single cache_peer_access directive may be evaluated multiple times
3267# for a given transaction because individual peer selection algorithms
3268# may check it independently from each other. These redundant checks
3269# may be optimized away in future Squid versions.
3270#
3271# This clause only supports fast acl types.
3272# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
3273#
3274#Default:
3275# No peer usage restrictions.
3276
3277# TAG: neighbor_type_domain
3278# Modify the cache_peer neighbor type when passing requests
3279# about specific domains to the peer.
3280#
3281# Usage:
3282# neighbor_type_domain neighbor parent|sibling domain domain ...
3283#
3284# For example:
3285# cache_peer foo.example.com parent 3128 3130
3286# neighbor_type_domain foo.example.com sibling .au .de
3287#
3288# The above configuration treats all requests to foo.example.com as a
3289# parent proxy unless the request is for a .au or .de ccTLD domain name.
3290#Default:
3291# The peer type from cache_peer directive is used for all requests to that peer.
3292
3293# TAG: dead_peer_timeout (seconds)
3294# This controls how long Squid waits to declare a peer cache
3295# as "dead." If there are no ICP replies received in this
3296# amount of time, Squid will declare the peer dead and not
3297# expect to receive any further ICP replies. However, it
3298# continues to send ICP queries, and will mark the peer as
3299# alive upon receipt of the first subsequent ICP reply.
3300#
3301# This timeout also affects when Squid expects to receive ICP
3302# replies from peers. If more than 'dead_peer' seconds have
3303# passed since the last ICP reply was received, Squid will not
3304# expect to receive an ICP reply on the next query. Thus, if
3305# your time between requests is greater than this timeout, you
3306# will see a lot of requests sent DIRECT to origin servers
3307# instead of to your parents.
3308#Default:
3309# dead_peer_timeout 10 seconds
3310
3311# TAG: forward_max_tries
3312# Limits the number of attempts to forward the request.
3313#
3314# For the purpose of this limit, Squid counts all high-level request
3315# forwarding attempts, including any same-destination retries after
3316# certain persistent connection failures and any attempts to use a
3317# different peer. However, low-level connection reopening attempts
3318# (enabled using connect_retries) are not counted.
3319#
3320# See also: forward_timeout and connect_retries.
3321#Default:
3322# forward_max_tries 25
3323
3324# MEMORY CACHE OPTIONS
3325# -----------------------------------------------------------------------------
3326
3327# TAG: cache_mem (bytes)
3328# NOTE: THIS PARAMETER DOES NOT SPECIFY THE MAXIMUM PROCESS SIZE.
3329# IT ONLY PLACES A LIMIT ON HOW MUCH ADDITIONAL MEMORY SQUID WILL
3330# USE AS A MEMORY CACHE OF OBJECTS. SQUID USES MEMORY FOR OTHER
3331# THINGS AS WELL. SEE THE SQUID FAQ SECTION 8 FOR DETAILS.
3332#
3333# 'cache_mem' specifies the ideal amount of memory to be used
3334# for:
3335# * In-Transit objects
3336# * Hot Objects
3337# * Negative-Cached objects
3338#
3339# Data for these objects are stored in 4 KB blocks. This
3340# parameter specifies the ideal upper limit on the total size of
3341# 4 KB blocks allocated. In-Transit objects take the highest
3342# priority.
3343#
3344# In-transit objects have priority over the others. When
3345# additional space is needed for incoming data, negative-cached
3346# and hot objects will be released. In other words, the
3347# negative-cached and hot objects will fill up any unused space
3348# not needed for in-transit objects.
3349#
3350# If circumstances require, this limit will be exceeded.
3351# Specifically, if your incoming request rate requires more than
3352# 'cache_mem' of memory to hold in-transit objects, Squid will
3353# exceed this limit to satisfy the new requests. When the load
3354# decreases, blocks will be freed until the high-water mark is
3355# reached. Thereafter, blocks will be used to store hot
3356# objects.
3357#
3358# If shared memory caching is enabled, Squid does not use the shared
3359# cache space for in-transit objects, but they still consume as much
3360# local memory as they need. For more details about the shared memory
3361# cache, see memory_cache_shared.
3362#Default:
3363# cache_mem 256 MB
3364
3365# TAG: maximum_object_size_in_memory (bytes)
3366# Objects greater than this size will not be attempted to kept in
3367# the memory cache. This should be set high enough to keep objects
3368# accessed frequently in memory to improve performance whilst low
3369# enough to keep larger objects from hoarding cache_mem.
3370#Default:
3371# maximum_object_size_in_memory 512 KB
3372
3373# TAG: memory_cache_shared on|off
3374# Controls whether the memory cache is shared among SMP workers.
3375#
3376# The shared memory cache is meant to occupy cache_mem bytes and replace
3377# the non-shared memory cache, although some entities may still be
3378# cached locally by workers for now (e.g., internal and in-transit
3379# objects may be served from a local memory cache even if shared memory
3380# caching is enabled).
3381#
3382# By default, the memory cache is shared if and only if all of the
3383# following conditions are satisfied: Squid runs in SMP mode with
3384# multiple workers, cache_mem is positive, and Squid environment
3385# supports required IPC primitives (e.g., POSIX shared memory segments
3386# and GCC-style atomic operations).
3387#
3388# To avoid blocking locks, shared memory uses opportunistic algorithms
3389# that do not guarantee that every cachable entity that could have been
3390# shared among SMP workers will actually be shared.
3391#Default:
3392# "on" where supported if doing memory caching with multiple SMP workers.
3393
3394# TAG: memory_cache_mode
3395# Controls which objects to keep in the memory cache (cache_mem)
3396#
3397# always Keep most recently fetched objects in memory (default)
3398#
3399# disk Only disk cache hits are kept in memory, which means
3400# an object must first be cached on disk and then hit
3401# a second time before cached in memory.
3402#
3403# network Only objects fetched from network is kept in memory
3404#Default:
3405# Keep the most recently fetched objects in memory
3406
3407# TAG: memory_replacement_policy
3408# The memory replacement policy parameter determines which
3409# objects are purged from memory when memory space is needed.
3410#
3411# See cache_replacement_policy for details on algorithms.
3412#Default:
3413# memory_replacement_policy lru
3414
3415# DISK CACHE OPTIONS
3416# -----------------------------------------------------------------------------
3417
3418# TAG: cache_replacement_policy
3419# The cache replacement policy parameter determines which
3420# objects are evicted (replaced) when disk space is needed.
3421#
3422# lru : Squid's original list based LRU policy
3423# heap GDSF : Greedy-Dual Size Frequency
3424# heap LFUDA: Least Frequently Used with Dynamic Aging
3425# heap LRU : LRU policy implemented using a heap
3426#
3427# Applies to any cache_dir lines listed below this directive.
3428#
3429# The LRU policies keeps recently referenced objects.
3430#
3431# The heap GDSF policy optimizes object hit rate by keeping smaller
3432# popular objects in cache so it has a better chance of getting a
3433# hit. It achieves a lower byte hit rate than LFUDA though since
3434# it evicts larger (possibly popular) objects.
3435#
3436# The heap LFUDA policy keeps popular objects in cache regardless of
3437# their size and thus optimizes byte hit rate at the expense of
3438# hit rate since one large, popular object will prevent many
3439# smaller, slightly less popular objects from being cached.
3440#
3441# Both policies utilize a dynamic aging mechanism that prevents
3442# cache pollution that can otherwise occur with frequency-based
3443# replacement policies.
3444#
3445# NOTE: if using the LFUDA replacement policy you should increase
3446# the value of maximum_object_size above its default of 4 MB to
3447# to maximize the potential byte hit rate improvement of LFUDA.
3448#
3449# For more information about the GDSF and LFUDA cache replacement
3450# policies see http://www.hpl.hp.com/techreports/1999/HPL-1999-69.html
3451# and http://fog.hpl.external.hp.com/techreports/98/HPL-98-173.html.
3452#Default:
3453# cache_replacement_policy lru
3454
3455# TAG: minimum_object_size (bytes)
3456# Objects smaller than this size will NOT be saved on disk. The
3457# value is specified in bytes, and the default is 0 KB, which
3458# means all responses can be stored.
3459#Default:
3460# no limit
3461
3462# TAG: maximum_object_size (bytes)
3463# Set the default value for max-size parameter on any cache_dir.
3464# The value is specified in bytes, and the default is 4 MB.
3465#
3466# If you wish to get a high BYTES hit ratio, you should probably
3467# increase this (one 32 MB object hit counts for 3200 10KB
3468# hits).
3469#
3470# If you wish to increase hit ratio more than you want to
3471# save bandwidth you should leave this low.
3472#
3473# NOTE: if using the LFUDA replacement policy you should increase
3474# this value to maximize the byte hit rate improvement of LFUDA!
3475# See cache_replacement_policy for a discussion of this policy.
3476#Default:
3477# maximum_object_size 4 MB
3478
3479# TAG: cache_dir
3480# Format:
3481# cache_dir Type Directory-Name Fs-specific-data [options]
3482#
3483# You can specify multiple cache_dir lines to spread the
3484# cache among different disk partitions.
3485#
3486# Type specifies the kind of storage system to use. Only "ufs"
3487# is built by default. To enable any of the other storage systems
3488# see the --enable-storeio configure option.
3489#
3490# 'Directory' is a top-level directory where cache swap
3491# files will be stored. If you want to use an entire disk
3492# for caching, this can be the mount-point directory.
3493# The directory must exist and be writable by the Squid
3494# process. Squid will NOT create this directory for you.
3495#
3496# In SMP configurations, cache_dir must not precede the workers option
3497# and should use configuration macros or conditionals to give each
3498# worker interested in disk caching a dedicated cache directory.
3499#
3500#
3501# ==== The ufs store type ====
3502#
3503# "ufs" is the old well-known Squid storage format that has always
3504# been there.
3505#
3506# Usage:
3507# cache_dir ufs Directory-Name Mbytes L1 L2 [options]
3508#
3509# 'Mbytes' is the amount of disk space (MB) to use under this
3510# directory. The default is 100 MB. Change this to suit your
3511# configuration. Do NOT put the size of your disk drive here.
3512# Instead, if you want Squid to use the entire disk drive,
3513# subtract 20% and use that value.
3514#
3515# 'L1' is the number of first-level subdirectories which
3516# will be created under the 'Directory'. The default is 16.
3517#
3518# 'L2' is the number of second-level subdirectories which
3519# will be created under each first-level directory. The default
3520# is 256.
3521#
3522#
3523# ==== The aufs store type ====
3524#
3525# "aufs" uses the same storage format as "ufs", utilizing
3526# POSIX-threads to avoid blocking the main Squid process on
3527# disk-I/O. This was formerly known in Squid as async-io.
3528#
3529# Usage:
3530# cache_dir aufs Directory-Name Mbytes L1 L2 [options]
3531#
3532# see argument descriptions under ufs above
3533#
3534#
3535# ==== The diskd store type ====
3536#
3537# "diskd" uses the same storage format as "ufs", utilizing a
3538# separate process to avoid blocking the main Squid process on
3539# disk-I/O.
3540#
3541# Usage:
3542# cache_dir diskd Directory-Name Mbytes L1 L2 [options] [Q1=n] [Q2=n]
3543#
3544# see argument descriptions under ufs above
3545#
3546# Q1 specifies the number of unacknowledged I/O requests when Squid
3547# stops opening new files. If this many messages are in the queues,
3548# Squid won't open new files. Default is 64
3549#
3550# Q2 specifies the number of unacknowledged messages when Squid
3551# starts blocking. If this many messages are in the queues,
3552# Squid blocks until it receives some replies. Default is 72
3553#
3554# When Q1 < Q2 (the default), the cache directory is optimized
3555# for lower response time at the expense of a decrease in hit
3556# ratio. If Q1 > Q2, the cache directory is optimized for
3557# higher hit ratio at the expense of an increase in response
3558# time.
3559#
3560#
3561# ==== The rock store type ====
3562#
3563# Usage:
3564# cache_dir rock Directory-Name Mbytes [options]
3565#
3566# The Rock Store type is a database-style storage. All cached
3567# entries are stored in a "database" file, using fixed-size slots.
3568# A single entry occupies one or more slots.
3569#
3570# If possible, Squid using Rock Store creates a dedicated kid
3571# process called "disker" to avoid blocking Squid worker(s) on disk
3572# I/O. One disker kid is created for each rock cache_dir. Diskers
3573# are created only when Squid, running in daemon mode, has support
3574# for the IpcIo disk I/O module.
3575#
3576# swap-timeout=msec: Squid will not start writing a miss to or
3577# reading a hit from disk if it estimates that the swap operation
3578# will take more than the specified number of milliseconds. By
3579# default and when set to zero, disables the disk I/O time limit
3580# enforcement. Ignored when using blocking I/O module because
3581# blocking synchronous I/O does not allow Squid to estimate the
3582# expected swap wait time.
3583#
3584# max-swap-rate=swaps/sec: Artificially limits disk access using
3585# the specified I/O rate limit. Swap out requests that
3586# would cause the average I/O rate to exceed the limit are
3587# delayed. Individual swap in requests (i.e., hits or reads) are
3588# not delayed, but they do contribute to measured swap rate and
3589# since they are placed in the same FIFO queue as swap out
3590# requests, they may wait longer if max-swap-rate is smaller.
3591# This is necessary on file systems that buffer "too
3592# many" writes and then start blocking Squid and other processes
3593# while committing those writes to disk. Usually used together
3594# with swap-timeout to avoid excessive delays and queue overflows
3595# when disk demand exceeds available disk "bandwidth". By default
3596# and when set to zero, disables the disk I/O rate limit
3597# enforcement. Currently supported by IpcIo module only.
3598#
3599# slot-size=bytes: The size of a database "record" used for
3600# storing cached responses. A cached response occupies at least
3601# one slot and all database I/O is done using individual slots so
3602# increasing this parameter leads to more disk space waste while
3603# decreasing it leads to more disk I/O overheads. Should be a
3604# multiple of your operating system I/O page size. Defaults to
3605# 16KBytes. A housekeeping header is stored with each slot and
3606# smaller slot-sizes will be rejected. The header is smaller than
3607# 100 bytes.
3608#
3609#
3610# ==== COMMON OPTIONS ====
3611#
3612# no-store no new objects should be stored to this cache_dir.
3613#
3614# min-size=n the minimum object size in bytes this cache_dir
3615# will accept. It's used to restrict a cache_dir
3616# to only store large objects (e.g. AUFS) while
3617# other stores are optimized for smaller objects
3618# (e.g. Rock).
3619# Defaults to 0.
3620#
3621# max-size=n the maximum object size in bytes this cache_dir
3622# supports.
3623# The value in maximum_object_size directive sets
3624# the default unless more specific details are
3625# available (ie a small store capacity).
3626#
3627# Note: To make optimal use of the max-size limits you should order
3628# the cache_dir lines with the smallest max-size value first.
3629#
3630#Default:
3631# No disk cache. Store cache ojects only in memory.
3632#
3633
3634# Uncomment and adjust the following to add a disk cache directory.
3635#cache_dir ufs /var/spool/squid 100 16 256
3636
3637# TAG: store_dir_select_algorithm
3638# How Squid selects which cache_dir to use when the response
3639# object will fit into more than one.
3640#
3641# Regardless of which algorithm is used the cache_dir min-size
3642# and max-size parameters are obeyed. As such they can affect
3643# the selection algorithm by limiting the set of considered
3644# cache_dir.
3645#
3646# Algorithms:
3647#
3648# least-load
3649#
3650# This algorithm is suited to caches with similar cache_dir
3651# sizes and disk speeds.
3652#
3653# The disk with the least I/O pending is selected.
3654# When there are multiple disks with the same I/O load ranking
3655# the cache_dir with most available capacity is selected.
3656#
3657# When a mix of cache_dir sizes are configured the faster disks
3658# have a naturally lower I/O loading and larger disks have more
3659# capacity. So space used to store objects and data throughput
3660# may be very unbalanced towards larger disks.
3661#
3662#
3663# round-robin
3664#
3665# This algorithm is suited to caches with unequal cache_dir
3666# disk sizes.
3667#
3668# Each cache_dir is selected in a rotation. The next suitable
3669# cache_dir is used.
3670#
3671# Available cache_dir capacity is only considered in relation
3672# to whether the object will fit and meets the min-size and
3673# max-size parameters.
3674#
3675# Disk I/O loading is only considered to prevent overload on slow
3676# disks. This algorithm does not spread objects by size, so any
3677# I/O loading per-disk may appear very unbalanced and volatile.
3678#
3679# If several cache_dirs use similar min-size, max-size, or other
3680# limits to to reject certain responses, then do not group such
3681# cache_dir lines together, to avoid round-robin selection bias
3682# towards the first cache_dir after the group. Instead, interleave
3683# cache_dir lines from different groups. For example:
3684#
3685# store_dir_select_algorithm round-robin
3686# cache_dir rock /hdd1 ... min-size=100000
3687# cache_dir rock /ssd1 ... max-size=99999
3688# cache_dir rock /hdd2 ... min-size=100000
3689# cache_dir rock /ssd2 ... max-size=99999
3690# cache_dir rock /hdd3 ... min-size=100000
3691# cache_dir rock /ssd3 ... max-size=99999
3692#Default:
3693# store_dir_select_algorithm least-load
3694
3695# TAG: max_open_disk_fds
3696# To avoid having disk as the I/O bottleneck Squid can optionally
3697# bypass the on-disk cache if more than this amount of disk file
3698# descriptors are open.
3699#
3700# A value of 0 indicates no limit.
3701#Default:
3702# no limit
3703
3704# TAG: cache_swap_low (percent, 0-100)
3705# The low-water mark for AUFS/UFS/diskd cache object eviction by
3706# the cache_replacement_policy algorithm.
3707#
3708# Removal begins when the swap (disk) usage of a cache_dir is
3709# above this low-water mark and attempts to maintain utilization
3710# near the low-water mark.
3711#
3712# As swap utilization increases towards the high-water mark set
3713# by cache_swap_high object eviction becomes more agressive.
3714#
3715# The value difference in percentages between low- and high-water
3716# marks represent an eviction rate of 300 objects per second and
3717# the rate continues to scale in agressiveness by multiples of
3718# this above the high-water mark.
3719#
3720# Defaults are 90% and 95%. If you have a large cache, 5% could be
3721# hundreds of MB. If this is the case you may wish to set these
3722# numbers closer together.
3723#
3724# See also cache_swap_high and cache_replacement_policy
3725#Default:
3726# cache_swap_low 90
3727
3728# TAG: cache_swap_high (percent, 0-100)
3729# The high-water mark for AUFS/UFS/diskd cache object eviction by
3730# the cache_replacement_policy algorithm.
3731#
3732# Removal begins when the swap (disk) usage of a cache_dir is
3733# above the low-water mark set by cache_swap_low and attempts to
3734# maintain utilization near the low-water mark.
3735#
3736# As swap utilization increases towards this high-water mark object
3737# eviction becomes more agressive.
3738#
3739# The value difference in percentages between low- and high-water
3740# marks represent an eviction rate of 300 objects per second and
3741# the rate continues to scale in agressiveness by multiples of
3742# this above the high-water mark.
3743#
3744# Defaults are 90% and 95%. If you have a large cache, 5% could be
3745# hundreds of MB. If this is the case you may wish to set these
3746# numbers closer together.
3747#
3748# See also cache_swap_low and cache_replacement_policy
3749#Default:
3750# cache_swap_high 95
3751
3752# LOGFILE OPTIONS
3753# -----------------------------------------------------------------------------
3754
3755# TAG: logformat
3756# Usage:
3757#
3758# logformat <name> <format specification>
3759#
3760# Defines an access log format.
3761#
3762# The <format specification> is a string with embedded % format codes
3763#
3764# % format codes all follow the same basic structure where all
3765# components but the formatcode are optional and usually unnecessary,
3766# especially when dealing with common codes.
3767#
3768# % [encoding] [-] [[0]width] [{arg}] formatcode [{arg}]
3769#
3770# encoding escapes or otherwise protects "special" characters:
3771#
3772# " Quoted string encoding where quote(") and
3773# backslash(\) characters are \-escaped while
3774# CR, LF, and TAB characters are encoded as \r,
3775# \n, and \t two-character sequences.
3776#
3777# [ Custom Squid encoding where percent(%), square
3778# brackets([]), backslash(\) and characters with
3779# codes outside of [32,126] range are %-encoded.
3780# SP is not encoded. Used by log_mime_hdrs.
3781#
3782# # URL encoding (a.k.a. percent-encoding) where
3783# all URL unsafe and control characters (per RFC
3784# 1738) are %-encoded.
3785#
3786# / Shell-like encoding where quote(") and
3787# backslash(\) characters are \-escaped while CR
3788# and LF characters are encoded as \r and \n
3789# two-character sequences. Values containing SP
3790# character(s) are surrounded by quotes(").
3791#
3792# ' Raw/as-is encoding with no escaping/quoting.
3793#
3794# Default encoding: When no explicit encoding is
3795# specified, each %code determines its own encoding.
3796# Most %codes use raw/as-is encoding, but some codes use
3797# a so called "pass-through URL encoding" where all URL
3798# unsafe and control characters (per RFC 1738) are
3799# %-encoded, but the percent character(%) is left as is.
3800#
3801# - left aligned
3802#
3803# width minimum and/or maximum field width:
3804# [width_min][.width_max]
3805# When minimum starts with 0, the field is zero-padded.
3806# String values exceeding maximum width are truncated.
3807#
3808# {arg} argument such as header name etc. This field may be
3809# placed before or after the token, but not both at once.
3810#
3811# Format codes:
3812#
3813# % a literal % character
3814# sn Unique sequence number per log line entry
3815# err_code The ID of an error response served by Squid or
3816# a similar internal error identifier.
3817# err_detail Additional err_code-dependent error information.
3818# note The annotation specified by the argument. Also
3819# logs the adaptation meta headers set by the
3820# adaptation_meta configuration parameter.
3821# If no argument given all annotations logged.
3822# The argument may include a separator to use with
3823# annotation values:
3824# name[:separator]
3825# By default, multiple note values are separated with ","
3826# and multiple notes are separated with "\r\n".
3827# When logging named notes with %{name}note, the
3828# explicitly configured separator is used between note
3829# values. When logging all notes with %note, the
3830# explicitly configured separator is used between
3831# individual notes. There is currently no way to
3832# specify both value and notes separators when logging
3833# all notes with %note.
3834#
3835# Connection related format codes:
3836#
3837# >a Client source IP address
3838# >A Client FQDN
3839# >p Client source port
3840# >eui Client source EUI (MAC address, EUI-48 or EUI-64 identifier)
3841# >la Local IP address the client connected to
3842# >lp Local port number the client connected to
3843# >qos Client connection TOS/DSCP value set by Squid
3844# >nfmark Client connection netfilter mark set by Squid
3845#
3846# la Local listening IP address the client connection was connected to.
3847# lp Local listening port number the client connection was connected to.
3848#
3849# <a Server IP address of the last server or peer connection
3850# <A Server FQDN or peer name
3851# <p Server port number of the last server or peer connection
3852# <la Local IP address of the last server or peer connection
3853# <lp Local port number of the last server or peer connection
3854# <qos Server connection TOS/DSCP value set by Squid
3855# <nfmark Server connection netfilter mark set by Squid
3856#
3857# >handshake Raw client handshake
3858# Initial client bytes received by Squid on a newly
3859# accepted TCP connection or inside a just established
3860# CONNECT tunnel. Squid stops accumulating handshake
3861# bytes as soon as the handshake parser succeeds or
3862# fails (determining whether the client is using the
3863# expected protocol).
3864#
3865# For HTTP clients, the handshake is the request line.
3866# For TLS clients, the handshake consists of all TLS
3867# records up to and including the TLS record that
3868# contains the last byte of the first ClientHello
3869# message. For clients using an unsupported protocol,
3870# this field contains the bytes received by Squid at the
3871# time of the handshake parsing failure.
3872#
3873# See the on_unsupported_protocol directive for more
3874# information on Squid handshake traffic expectations.
3875#
3876# Current support is limited to these contexts:
3877# - http_port connections, but only when the
3878# on_unsupported_protocol directive is in use.
3879# - https_port connections (and CONNECT tunnels) that
3880# are subject to the ssl_bump peek or stare action.
3881#
3882# To protect binary handshake data, this field is always
3883# base64-encoded (RFC 4648 Section 4). If logformat
3884# field encoding is configured, that encoding is applied
3885# on top of base64. Otherwise, the computed base64 value
3886# is recorded as is.
3887#
3888# Time related format codes:
3889#
3890# ts Seconds since epoch
3891# tu subsecond time (milliseconds)
3892# tl Local time. Optional strftime format argument
3893# default %d/%b/%Y:%H:%M:%S %z
3894# tg GMT time. Optional strftime format argument
3895# default %d/%b/%Y:%H:%M:%S %z
3896# tr Response time (milliseconds)
3897# dt Total time spent making DNS lookups (milliseconds)
3898# tS Approximate master transaction start time in
3899# <full seconds since epoch>.<fractional seconds> format.
3900# Currently, Squid considers the master transaction
3901# started when a complete HTTP request header initiating
3902# the transaction is received from the client. This is
3903# the same value that Squid uses to calculate transaction
3904# response time when logging %tr to access.log. Currently,
3905# Squid uses millisecond resolution for %tS values,
3906# similar to the default access.log "current time" field
3907# (%ts.%03tu).
3908#
3909# Access Control related format codes:
3910#
3911# et Tag returned by external acl
3912# ea Log string returned by external acl
3913# un User name (any available)
3914# ul User name from authentication
3915# ue User name from external acl helper
3916# ui User name from ident
3917# un A user name. Expands to the first available name
3918# from the following list of information sources:
3919# - authenticated user name, like %ul
3920# - user name supplied by an external ACL, like %ue
3921# - SSL client name, like %us
3922# - ident user name, like %ui
3923# credentials Client credentials. The exact meaning depends on
3924# the authentication scheme: For Basic authentication,
3925# it is the password; for Digest, the realm sent by the
3926# client; for NTLM and Negotiate, the client challenge
3927# or client credentials prefixed with "YR " or "KK ".
3928#
3929# HTTP related format codes:
3930#
3931# REQUEST
3932#
3933# [http::]rm Request method (GET/POST etc)
3934# [http::]>rm Request method from client
3935# [http::]<rm Request method sent to server or peer
3936#
3937# [http::]ru Request URL received (or computed) and sanitized
3938#
3939# Logs request URI received from the client, a
3940# request adaptation service, or a request
3941# redirector (whichever was applied last).
3942#
3943# Computed URLs are URIs of internally generated
3944# requests and various "error:..." URIs.
3945#
3946# Honors strip_query_terms and uri_whitespace.
3947#
3948# This field is not encoded by default. Encoding
3949# this field using variants of %-encoding will
3950# clash with uri_whitespace modifications that
3951# also use %-encoding.
3952#
3953# [http::]>ru Request URL received from the client (or computed)
3954#
3955# Computed URLs are URIs of internally generated
3956# requests and various "error:..." URIs.
3957#
3958# Unlike %ru, this request URI is not affected
3959# by request adaptation, URL rewriting services,
3960# and strip_query_terms.
3961#
3962# Honors uri_whitespace.
3963#
3964# This field is using pass-through URL encoding
3965# by default. Encoding this field using other
3966# variants of %-encoding will clash with
3967# uri_whitespace modifications that also use
3968# %-encoding.
3969#
3970# [http::]<ru Request URL sent to server or peer
3971# [http::]>rs Request URL scheme from client
3972# [http::]<rs Request URL scheme sent to server or peer
3973# [http::]>rd Request URL domain from client
3974# [http::]<rd Request URL domain sent to server or peer
3975# [http::]>rP Request URL port from client
3976# [http::]<rP Request URL port sent to server or peer
3977# [http::]rp Request URL path excluding hostname
3978# [http::]>rp Request URL path excluding hostname from client
3979# [http::]<rp Request URL path excluding hostname sent to server or peer
3980# [http::]rv Request protocol version
3981# [http::]>rv Request protocol version from client
3982# [http::]<rv Request protocol version sent to server or peer
3983#
3984# [http::]>h Original received request header.
3985# Usually differs from the request header sent by
3986# Squid, although most fields are often preserved.
3987# Accepts optional header field name/value filter
3988# argument using name[:[separator]element] format.
3989# [http::]>ha Received request header after adaptation and
3990# redirection (pre-cache REQMOD vectoring point).
3991# Usually differs from the request header sent by
3992# Squid, although most fields are often preserved.
3993# Optional header name argument as for >h
3994#
3995# RESPONSE
3996#
3997# [http::]<Hs HTTP status code received from the next hop
3998# [http::]>Hs HTTP status code sent to the client
3999#
4000# [http::]<h Reply header. Optional header name argument
4001# as for >h
4002#
4003# [http::]mt MIME content type
4004#
4005#
4006# SIZE COUNTERS
4007#
4008# [http::]st Total size of request + reply traffic with client
4009# [http::]>st Total size of request received from client.
4010# Excluding chunked encoding bytes.
4011# [http::]<st Total size of reply sent to client (after adaptation)
4012#
4013# [http::]>sh Size of request headers received from client
4014# [http::]<sh Size of reply headers sent to client (after adaptation)
4015#
4016# [http::]<sH Reply high offset sent
4017# [http::]<sS Upstream object size
4018#
4019# [http::]<bs Number of HTTP-equivalent message body bytes
4020# received from the next hop, excluding chunked
4021# transfer encoding and control messages.
4022# Generated FTP/Gopher listings are treated as
4023# received bodies.
4024#
4025# TIMING
4026#
4027# [http::]<pt Peer response time in milliseconds. The timer starts
4028# when the last request byte is sent to the next hop
4029# and stops when the last response byte is received.
4030# [http::]<tt Total time in milliseconds. The timer
4031# starts with the first connect request (or write I/O)
4032# sent to the first selected peer. The timer stops
4033# with the last I/O with the last peer.
4034#
4035# Squid handling related format codes:
4036#
4037# Ss Squid request status (TCP_MISS etc)
4038# Sh Squid hierarchy status (DEFAULT_PARENT etc)
4039#
4040# SSL-related format codes:
4041#
4042# ssl::bump_mode SslBump decision for the transaction:
4043#
4044# For CONNECT requests that initiated bumping of
4045# a connection and for any request received on
4046# an already bumped connection, Squid logs the
4047# corresponding SslBump mode ("splice", "bump",
4048# "peek", "stare", "terminate", "server-first"
4049# or "client-first"). See the ssl_bump option
4050# for more information about these modes.
4051#
4052# A "none" token is logged for requests that
4053# triggered "ssl_bump" ACL evaluation matching
4054# a "none" rule.
4055#
4056# In all other cases, a single dash ("-") is
4057# logged.
4058#
4059# ssl::>sni SSL client SNI sent to Squid.
4060#
4061# ssl::>cert_subject
4062# The Subject field of the received client
4063# SSL certificate or a dash ('-') if Squid has
4064# received an invalid/malformed certificate or
4065# no certificate at all. Consider encoding the
4066# logged value because Subject often has spaces.
4067#
4068# ssl::>cert_issuer
4069# The Issuer field of the received client
4070# SSL certificate or a dash ('-') if Squid has
4071# received an invalid/malformed certificate or
4072# no certificate at all. Consider encoding the
4073# logged value because Issuer often has spaces.
4074#
4075# ssl::<cert_subject
4076# The Subject field of the received server
4077# TLS certificate or a dash ('-') if this is
4078# not available. Consider encoding the logged
4079# value because Subject often has spaces.
4080#
4081# ssl::<cert_issuer
4082# The Issuer field of the received server
4083# TLS certificate or a dash ('-') if this is
4084# not available. Consider encoding the logged
4085# value because Issuer often has spaces.
4086#
4087# ssl::<cert_errors
4088# The list of certificate validation errors
4089# detected by Squid (including OpenSSL and
4090# certificate validation helper components). The
4091# errors are listed in the discovery order. By
4092# default, the error codes are separated by ':'.
4093# Accepts an optional separator argument.
4094#
4095# %ssl::>negotiated_version The negotiated TLS version of the
4096# client connection.
4097#
4098# %ssl::<negotiated_version The negotiated TLS version of the
4099# last server or peer connection.
4100#
4101# %ssl::>received_hello_version The TLS version of the Hello
4102# message received from TLS client.
4103#
4104# %ssl::<received_hello_version The TLS version of the Hello
4105# message received from TLS server.
4106#
4107# %ssl::>received_supported_version The maximum TLS version
4108# supported by the TLS client.
4109#
4110# %ssl::<received_supported_version The maximum TLS version
4111# supported by the TLS server.
4112#
4113# %ssl::>negotiated_cipher The negotiated cipher of the
4114# client connection.
4115#
4116# %ssl::<negotiated_cipher The negotiated cipher of the
4117# last server or peer connection.
4118#
4119# If ICAP is enabled, the following code becomes available (as
4120# well as ICAP log codes documented with the icap_log option):
4121#
4122# icap::tt Total ICAP processing time for the HTTP
4123# transaction. The timer ticks when ICAP
4124# ACLs are checked and when ICAP
4125# transaction is in progress.
4126#
4127# If adaptation is enabled the following codes become available:
4128#
4129# adapt::<last_h The header of the last ICAP response or
4130# meta-information from the last eCAP
4131# transaction related to the HTTP transaction.
4132# Like <h, accepts an optional header name
4133# argument.
4134#
4135# adapt::sum_trs Summed adaptation transaction response
4136# times recorded as a comma-separated list in
4137# the order of transaction start time. Each time
4138# value is recorded as an integer number,
4139# representing response time of one or more
4140# adaptation (ICAP or eCAP) transaction in
4141# milliseconds. When a failed transaction is
4142# being retried or repeated, its time is not
4143# logged individually but added to the
4144# replacement (next) transaction. See also:
4145# adapt::all_trs.
4146#
4147# adapt::all_trs All adaptation transaction response times.
4148# Same as adaptation_strs but response times of
4149# individual transactions are never added
4150# together. Instead, all transaction response
4151# times are recorded individually.
4152#
4153# You can prefix adapt::*_trs format codes with adaptation
4154# service name in curly braces to record response time(s) specific
4155# to that service. For example: %{my_service}adapt::sum_trs
4156#
4157# The default formats available (which do not need re-defining) are:
4158#
4159#logformat squid %ts.%03tu %6tr %>a %Ss/%03>Hs %<st %rm %ru %[un %Sh/%<a %mt
4160#logformat common %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st %Ss:%Sh
4161#logformat combined %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st "%{Referer}>h" "%{User-Agent}>h" %Ss:%Sh
4162#logformat referrer %ts.%03tu %>a %{Referer}>h %ru
4163#logformat useragent %>a [%tl] "%{User-Agent}>h"
4164#
4165# NOTE: When the log_mime_hdrs directive is set to ON.
4166# The squid, common and combined formats have a safely encoded copy
4167# of the mime headers appended to each line within a pair of brackets.
4168#
4169# NOTE: The common and combined formats are not quite true to the Apache definition.
4170# The logs from Squid contain an extra status and hierarchy code appended.
4171#
4172#Default:
4173# The format definitions squid, common, combined, referrer, useragent are built in.
4174
4175# TAG: access_log
4176# Configures whether and how Squid logs HTTP and ICP transactions.
4177# If access logging is enabled, a single line is logged for every
4178# matching HTTP or ICP request. The recommended directive formats are:
4179#
4180# access_log <module>:<place> [option ...] [acl acl ...]
4181# access_log none [acl acl ...]
4182#
4183# The following directive format is accepted but may be deprecated:
4184# access_log <module>:<place> [<logformat name> [acl acl ...]]
4185#
4186# In most cases, the first ACL name must not contain the '=' character
4187# and should not be equal to an existing logformat name. You can always
4188# start with an 'all' ACL to work around those restrictions.
4189#
4190# Will log to the specified module:place using the specified format (which
4191# must be defined in a logformat directive) those entries which match
4192# ALL the acl's specified (which must be defined in acl clauses).
4193# If no acl is specified, all requests will be logged to this destination.
4194#
4195# ===== Available options for the recommended directive format =====
4196#
4197# logformat=name Names log line format (either built-in or
4198# defined by a logformat directive). Defaults
4199# to 'squid'.
4200#
4201# buffer-size=64KB Defines approximate buffering limit for log
4202# records (see buffered_logs). Squid should not
4203# keep more than the specified size and, hence,
4204# should flush records before the buffer becomes
4205# full to avoid overflows under normal
4206# conditions (the exact flushing algorithm is
4207# module-dependent though). The on-error option
4208# controls overflow handling.
4209#
4210# on-error=die|drop Defines action on unrecoverable errors. The
4211# 'drop' action ignores (i.e., does not log)
4212# affected log records. The default 'die' action
4213# kills the affected worker. The drop action
4214# support has not been tested for modules other
4215# than tcp.
4216#
4217# rotate=N Specifies the number of log file rotations to
4218# make when you run 'squid -k rotate'. The default
4219# is to obey the logfile_rotate directive. Setting
4220# rotate=0 will disable the file name rotation,
4221# but the log files are still closed and re-opened.
4222# This will enable you to rename the logfiles
4223# yourself just before sending the rotate signal.
4224# Only supported by the stdio module.
4225#
4226# ===== Modules Currently available =====
4227#
4228# none Do not log any requests matching these ACL.
4229# Do not specify Place or logformat name.
4230#
4231# stdio Write each log line to disk immediately at the completion of
4232# each request.
4233# Place: the filename and path to be written.
4234#
4235# daemon Very similar to stdio. But instead of writing to disk the log
4236# line is passed to a daemon helper for asychronous handling instead.
4237# Place: varies depending on the daemon.
4238#
4239# log_file_daemon Place: the file name and path to be written.
4240#
4241# syslog To log each request via syslog facility.
4242# Place: The syslog facility and priority level for these entries.
4243# Place Format: facility.priority
4244#
4245# where facility could be any of:
4246# authpriv, daemon, local0 ... local7 or user.
4247#
4248# And priority could be any of:
4249# err, warning, notice, info, debug.
4250#
4251# udp To send each log line as text data to a UDP receiver.
4252# Place: The destination host name or IP and port.
4253# Place Format: //host:port
4254#
4255# tcp To send each log line as text data to a TCP receiver.
4256# Lines may be accumulated before sending (see buffered_logs).
4257# Place: The destination host name or IP and port.
4258# Place Format: //host:port
4259#
4260# Default:
4261# access_log daemon:/var/log/squid/access.log squid
4262#Default:
4263# access_log daemon:/var/log/squid/access.log squid
4264
4265# TAG: icap_log
4266# ICAP log files record ICAP transaction summaries, one line per
4267# transaction.
4268#
4269# The icap_log option format is:
4270# icap_log <filepath> [<logformat name> [acl acl ...]]
4271# icap_log none [acl acl ...]]
4272#
4273# Please see access_log option documentation for details. The two
4274# kinds of logs share the overall configuration approach and many
4275# features.
4276#
4277# ICAP processing of a single HTTP message or transaction may
4278# require multiple ICAP transactions. In such cases, multiple
4279# ICAP transaction log lines will correspond to a single access
4280# log line.
4281#
4282# ICAP log supports many access.log logformat %codes. In ICAP context,
4283# HTTP message-related %codes are applied to the HTTP message embedded
4284# in an ICAP message. Logformat "%http::>..." codes are used for HTTP
4285# messages embedded in ICAP requests while "%http::<..." codes are used
4286# for HTTP messages embedded in ICAP responses. For example:
4287#
4288# http::>h To-be-adapted HTTP message headers sent by Squid to
4289# the ICAP service. For REQMOD transactions, these are
4290# HTTP request headers. For RESPMOD, these are HTTP
4291# response headers, but Squid currently cannot log them
4292# (i.e., %http::>h will expand to "-" for RESPMOD).
4293#
4294# http::<h Adapted HTTP message headers sent by the ICAP
4295# service to Squid (i.e., HTTP request headers in regular
4296# REQMOD; HTTP response headers in RESPMOD and during
4297# request satisfaction in REQMOD).
4298#
4299# ICAP OPTIONS transactions do not embed HTTP messages.
4300#
4301# Several logformat codes below deal with ICAP message bodies. An ICAP
4302# message body, if any, typically includes a complete HTTP message
4303# (required HTTP headers plus optional HTTP message body). When
4304# computing HTTP message body size for these logformat codes, Squid
4305# either includes or excludes chunked encoding overheads; see
4306# code-specific documentation for details.
4307#
4308# For Secure ICAP services, all size-related information is currently
4309# computed before/after TLS encryption/decryption, as if TLS was not
4310# in use at all.
4311#
4312# The following format codes are also available for ICAP logs:
4313#
4314# icap::<A ICAP server IP address. Similar to <A.
4315#
4316# icap::<service_name ICAP service name from the icap_service
4317# option in Squid configuration file.
4318#
4319# icap::ru ICAP Request-URI. Similar to ru.
4320#
4321# icap::rm ICAP request method (REQMOD, RESPMOD, or
4322# OPTIONS). Similar to existing rm.
4323#
4324# icap::>st The total size of the ICAP request sent to the ICAP
4325# server (ICAP headers + ICAP body), including chunking
4326# metadata (if any).
4327#
4328# icap::<st The total size of the ICAP response received from the
4329# ICAP server (ICAP headers + ICAP body), including
4330# chunking metadata (if any).
4331#
4332# icap::<bs The size of the ICAP response body received from the
4333# ICAP server, excluding chunking metadata (if any).
4334#
4335# icap::tr Transaction response time (in
4336# milliseconds). The timer starts when
4337# the ICAP transaction is created and
4338# stops when the transaction is completed.
4339# Similar to tr.
4340#
4341# icap::tio Transaction I/O time (in milliseconds). The
4342# timer starts when the first ICAP request
4343# byte is scheduled for sending. The timers
4344# stops when the last byte of the ICAP response
4345# is received.
4346#
4347# icap::to Transaction outcome: ICAP_ERR* for all
4348# transaction errors, ICAP_OPT for OPTION
4349# transactions, ICAP_ECHO for 204
4350# responses, ICAP_MOD for message
4351# modification, and ICAP_SAT for request
4352# satisfaction. Similar to Ss.
4353#
4354# icap::Hs ICAP response status code. Similar to Hs.
4355#
4356# icap::>h ICAP request header(s). Similar to >h.
4357#
4358# icap::<h ICAP response header(s). Similar to <h.
4359#
4360# The default ICAP log format, which can be used without an explicit
4361# definition, is called icap_squid:
4362#
4363#logformat icap_squid %ts.%03tu %6icap::tr %>A %icap::to/%03icap::Hs %icap::<st %icap::rm %icap::ru %un -/%icap::<A -
4364#
4365# See also: logformat and %adapt::<last_h
4366#Default:
4367# none
4368
4369# TAG: logfile_daemon
4370# Specify the path to the logfile-writing daemon. This daemon is
4371# used to write the access and store logs, if configured.
4372#
4373# Squid sends a number of commands to the log daemon:
4374# L<data>\n - logfile data
4375# R\n - rotate file
4376# T\n - truncate file
4377# O\n - reopen file
4378# F\n - flush file
4379# r<n>\n - set rotate count to <n>
4380# b<n>\n - 1 = buffer output, 0 = don't buffer output
4381#
4382# No responses is expected.
4383#Default:
4384# logfile_daemon /usr/lib/squid/log_file_daemon
4385
4386# TAG: stats_collection allow|deny acl acl...
4387# This options allows you to control which requests gets accounted
4388# in performance counters.
4389#
4390# This clause only supports fast acl types.
4391# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4392#Default:
4393# Allow logging for all transactions.
4394
4395# TAG: cache_store_log
4396# Logs the activities of the storage manager. Shows which
4397# objects are ejected from the cache, and which objects are
4398# saved and for how long.
4399# There are not really utilities to analyze this data, so you can safely
4400# disable it (the default).
4401#
4402# Store log uses modular logging outputs. See access_log for the list
4403# of modules supported.
4404#
4405# Example:
4406# cache_store_log stdio:/var/log/squid/store.log
4407# cache_store_log daemon:/var/log/squid/store.log
4408#Default:
4409# none
4410
4411# TAG: cache_swap_state
4412# Location for the cache "swap.state" file. This index file holds
4413# the metadata of objects saved on disk. It is used to rebuild
4414# the cache during startup. Normally this file resides in each
4415# 'cache_dir' directory, but you may specify an alternate
4416# pathname here. Note you must give a full filename, not just
4417# a directory. Since this is the index for the whole object
4418# list you CANNOT periodically rotate it!
4419#
4420# If %s can be used in the file name it will be replaced with a
4421# a representation of the cache_dir name where each / is replaced
4422# with '.'. This is needed to allow adding/removing cache_dir
4423# lines when cache_swap_log is being used.
4424#
4425# If have more than one 'cache_dir', and %s is not used in the name
4426# these swap logs will have names such as:
4427#
4428# cache_swap_log.00
4429# cache_swap_log.01
4430# cache_swap_log.02
4431#
4432# The numbered extension (which is added automatically)
4433# corresponds to the order of the 'cache_dir' lines in this
4434# configuration file. If you change the order of the 'cache_dir'
4435# lines in this file, these index files will NOT correspond to
4436# the correct 'cache_dir' entry (unless you manually rename
4437# them). We recommend you do NOT use this option. It is
4438# better to keep these index files in each 'cache_dir' directory.
4439#Default:
4440# Store the journal inside its cache_dir
4441
4442# TAG: logfile_rotate
4443# Specifies the default number of logfile rotations to make when you
4444# type 'squid -k rotate'. The default is 10, which will rotate
4445# with extensions 0 through 9. Setting logfile_rotate to 0 will
4446# disable the file name rotation, but the logfiles are still closed
4447# and re-opened. This will enable you to rename the logfiles
4448# yourself just before sending the rotate signal.
4449#
4450# Note, from Squid-3.1 this option is only a default for cache.log,
4451# that log can be rotated separately by using debug_options.
4452#
4453# Note, from Squid-4 this option is only a default for access.log
4454# recorded by stdio: module. Those logs can be rotated separately by
4455# using the rotate=N option on their access_log directive.
4456#
4457# Note, the 'squid -k rotate' command normally sends a USR1
4458# signal to the running squid process. In certain situations
4459# (e.g. on Linux with Async I/O), USR1 is used for other
4460# purposes, so -k rotate uses another signal. It is best to get
4461# in the habit of using 'squid -k rotate' instead of 'kill -USR1
4462# <pid>'.
4463#
4464# Note, for Debian/Linux the default of logfile_rotate is
4465# zero, since it includes external logfile-rotation methods.
4466#Default:
4467# logfile_rotate 0
4468
4469# TAG: mime_table
4470# Path to Squid's icon configuration file.
4471#
4472# You shouldn't need to change this, but the default file contains
4473# examples and formatting information if you do.
4474#Default:
4475# mime_table /usr/share/squid/mime.conf
4476
4477# TAG: log_mime_hdrs on|off
4478# The Cache can record both the request and the response MIME
4479# headers for each HTTP transaction. The headers are encoded
4480# safely and will appear as two bracketed fields at the end of
4481# the access log (for either the native or httpd-emulated log
4482# formats). To enable this logging set log_mime_hdrs to 'on'.
4483#Default:
4484# log_mime_hdrs off
4485
4486# TAG: pid_filename
4487# A filename to write the process-id to. To disable, enter "none".
4488#Default:
4489# pid_filename /var/run/squid.pid
4490
4491# TAG: client_netmask
4492# A netmask for client addresses in logfiles and cachemgr output.
4493# Change this to protect the privacy of your cache clients.
4494# A netmask of 255.255.255.0 will log all IP's in that range with
4495# the last digit set to '0'.
4496#Default:
4497# Log full client IP address
4498
4499# TAG: strip_query_terms
4500# By default, Squid strips query terms from requested URLs before
4501# logging. This protects your user's privacy and reduces log size.
4502#
4503# When investigating HIT/MISS or other caching behaviour you
4504# will need to disable this to see the full URL used by Squid.
4505#Default:
4506# strip_query_terms on
4507
4508# TAG: buffered_logs on|off
4509# Whether to write/send access_log records ASAP or accumulate them and
4510# then write/send them in larger chunks. Buffering may improve
4511# performance because it decreases the number of I/Os. However,
4512# buffering increases the delay before log records become available to
4513# the final recipient (e.g., a disk file or logging daemon) and,
4514# hence, increases the risk of log records loss.
4515#
4516# Note that even when buffered_logs are off, Squid may have to buffer
4517# records if it cannot write/send them immediately due to pending I/Os
4518# (e.g., the I/O writing the previous log record) or connectivity loss.
4519#
4520# Currently honored by 'daemon' and 'tcp' access_log modules only.
4521#Default:
4522# buffered_logs off
4523
4524# TAG: netdb_filename
4525# Where Squid stores it's netdb journal.
4526# When enabled this journal preserves netdb state between restarts.
4527#
4528# To disable, enter "none".
4529#Default:
4530# netdb_filename stdio:/var/spool/squid/netdb.state
4531
4532# OPTIONS FOR TROUBLESHOOTING
4533# -----------------------------------------------------------------------------
4534
4535# TAG: cache_log
4536# Squid administrative logging file.
4537#
4538# This is where general information about Squid behavior goes. You can
4539# increase the amount of data logged to this file and how often it is
4540# rotated with "debug_options"
4541#Default:
4542# cache_log /var/log/squid/cache.log
4543
4544# TAG: debug_options
4545# Logging options are set as section,level where each source file
4546# is assigned a unique section. Lower levels result in less
4547# output, Full debugging (level 9) can result in a very large
4548# log file, so be careful.
4549#
4550# The magic word "ALL" sets debugging levels for all sections.
4551# The default is to run with "ALL,1" to record important warnings.
4552#
4553# The rotate=N option can be used to keep more or less of these logs
4554# than would otherwise be kept by logfile_rotate.
4555# For most uses a single log should be enough to monitor current
4556# events affecting Squid.
4557#Default:
4558# Log all critical and important messages.
4559
4560# TAG: coredump_dir
4561# By default Squid leaves core files in the directory from where
4562# it was started. If you set 'coredump_dir' to a directory
4563# that exists, Squid will chdir() to that directory at startup
4564# and coredump files will be left there.
4565#
4566#Default:
4567# Use the directory from where Squid was started.
4568#
4569
4570# Leave coredumps in the first cache dir
4571coredump_dir /var/spool/squid
4572
4573# OPTIONS FOR FTP GATEWAYING
4574# -----------------------------------------------------------------------------
4575
4576# TAG: ftp_user
4577# If you want the anonymous login password to be more informative
4578# (and enable the use of picky FTP servers), set this to something
4579# reasonable for your domain, like wwwuser@somewhere.net
4580#
4581# The reason why this is domainless by default is the
4582# request can be made on the behalf of a user in any domain,
4583# depending on how the cache is used.
4584# Some FTP server also validate the email address is valid
4585# (for example perl.com).
4586#Default:
4587# ftp_user Squid@
4588
4589# TAG: ftp_passive
4590# If your firewall does not allow Squid to use passive
4591# connections, turn off this option.
4592#
4593# Use of ftp_epsv_all option requires this to be ON.
4594#Default:
4595# ftp_passive on
4596
4597# TAG: ftp_epsv_all
4598# FTP Protocol extensions permit the use of a special "EPSV ALL" command.
4599#
4600# NATs may be able to put the connection on a "fast path" through the
4601# translator, as the EPRT command will never be used and therefore,
4602# translation of the data portion of the segments will never be needed.
4603#
4604# When a client only expects to do two-way FTP transfers this may be
4605# useful.
4606# If squid finds that it must do a three-way FTP transfer after issuing
4607# an EPSV ALL command, the FTP session will fail.
4608#
4609# If you have any doubts about this option do not use it.
4610# Squid will nicely attempt all other connection methods.
4611#
4612# Requires ftp_passive to be ON (default) for any effect.
4613#Default:
4614# ftp_epsv_all off
4615
4616# TAG: ftp_epsv
4617# FTP Protocol extensions permit the use of a special "EPSV" command.
4618#
4619# NATs may be able to put the connection on a "fast path" through the
4620# translator using EPSV, as the EPRT command will never be used
4621# and therefore, translation of the data portion of the segments
4622# will never be needed.
4623#
4624# EPSV is often required to interoperate with FTP servers on IPv6
4625# networks. On the other hand, it may break some IPv4 servers.
4626#
4627# By default, EPSV may try EPSV with any FTP server. To fine tune
4628# that decision, you may restrict EPSV to certain clients or servers
4629# using ACLs:
4630#
4631# ftp_epsv allow|deny al1 acl2 ...
4632#
4633# WARNING: Disabling EPSV may cause problems with external NAT and IPv6.
4634#
4635# Only fast ACLs are supported.
4636# Requires ftp_passive to be ON (default) for any effect.
4637#Default:
4638# none
4639
4640# TAG: ftp_eprt
4641# FTP Protocol extensions permit the use of a special "EPRT" command.
4642#
4643# This extension provides a protocol neutral alternative to the
4644# IPv4-only PORT command. When supported it enables active FTP data
4645# channels over IPv6 and efficient NAT handling.
4646#
4647# Turning this OFF will prevent EPRT being attempted and will skip
4648# straight to using PORT for IPv4 servers.
4649#
4650# Some devices are known to not handle this extension correctly and
4651# may result in crashes. Devices which suport EPRT enough to fail
4652# cleanly will result in Squid attempting PORT anyway. This directive
4653# should only be disabled when EPRT results in device failures.
4654#
4655# WARNING: Doing so will convert Squid back to the old behavior with all
4656# the related problems with external NAT devices/layers and IPv4-only FTP.
4657#Default:
4658# ftp_eprt on
4659
4660# TAG: ftp_sanitycheck
4661# For security and data integrity reasons Squid by default performs
4662# sanity checks of the addresses of FTP data connections ensure the
4663# data connection is to the requested server. If you need to allow
4664# FTP connections to servers using another IP address for the data
4665# connection turn this off.
4666#Default:
4667# ftp_sanitycheck on
4668
4669# TAG: ftp_telnet_protocol
4670# The FTP protocol is officially defined to use the telnet protocol
4671# as transport channel for the control connection. However, many
4672# implementations are broken and does not respect this aspect of
4673# the FTP protocol.
4674#
4675# If you have trouble accessing files with ASCII code 255 in the
4676# path or similar problems involving this ASCII code you can
4677# try setting this directive to off. If that helps, report to the
4678# operator of the FTP server in question that their FTP server
4679# is broken and does not follow the FTP standard.
4680#Default:
4681# ftp_telnet_protocol on
4682
4683# OPTIONS FOR EXTERNAL SUPPORT PROGRAMS
4684# -----------------------------------------------------------------------------
4685
4686# TAG: diskd_program
4687# Specify the location of the diskd executable.
4688# Note this is only useful if you have compiled in
4689# diskd as one of the store io modules.
4690#Default:
4691# diskd_program /usr/lib/squid/diskd
4692
4693# TAG: unlinkd_program
4694# Specify the location of the executable for file deletion process.
4695#Default:
4696# unlinkd_program /usr/lib/squid/unlinkd
4697
4698# TAG: pinger_program
4699# Specify the location of the executable for the pinger process.
4700#Default:
4701# pinger_program /usr/lib/squid/pinger
4702
4703# TAG: pinger_enable
4704# Control whether the pinger is active at run-time.
4705# Enables turning ICMP pinger on and off with a simple
4706# squid -k reconfigure.
4707#Default:
4708# pinger_enable on
4709
4710# OPTIONS FOR URL REWRITING
4711# -----------------------------------------------------------------------------
4712
4713# TAG: url_rewrite_program
4714# Specify the location of the executable URL rewriter to use.
4715# Since they can perform almost any function there isn't one included.
4716#
4717# For each requested URL, the rewriter will receive on line with the format
4718#
4719# [channel-ID <SP>] URL [<SP> extras]<NL>
4720#
4721# See url_rewrite_extras on how to send "extras" with optional values to
4722# the helper.
4723# After processing the request the helper must reply using the following format:
4724#
4725# [channel-ID <SP>] result [<SP> kv-pairs]
4726#
4727# The result code can be:
4728#
4729# OK status=30N url="..."
4730# Redirect the URL to the one supplied in 'url='.
4731# 'status=' is optional and contains the status code to send
4732# the client in Squids HTTP response. It must be one of the
4733# HTTP redirect status codes: 301, 302, 303, 307, 308.
4734# When no status is given Squid will use 302.
4735#
4736# OK rewrite-url="..."
4737# Rewrite the URL to the one supplied in 'rewrite-url='.
4738# The new URL is fetched directly by Squid and returned to
4739# the client as the response to its request.
4740#
4741# OK
4742# When neither of url= and rewrite-url= are sent Squid does
4743# not change the URL.
4744#
4745# ERR
4746# Do not change the URL.
4747#
4748# BH
4749# An internal error occurred in the helper, preventing
4750# a result being identified. The 'message=' key name is
4751# reserved for delivering a log message.
4752#
4753#
4754# In addition to the above kv-pairs Squid also understands the following
4755# optional kv-pairs received from URL rewriters:
4756# clt_conn_tag=TAG
4757# Associates a TAG with the client TCP connection.
4758# The TAG is treated as a regular annotation but persists across
4759# future requests on the client connection rather than just the
4760# current request. A helper may update the TAG during subsequent
4761# requests be returning a new kv-pair.
4762#
4763# When using the concurrency= option the protocol is changed by
4764# introducing a query channel tag in front of the request/response.
4765# The query channel tag is a number between 0 and concurrency-1.
4766# This value must be echoed back unchanged to Squid as the first part
4767# of the response relating to its request.
4768#
4769# WARNING: URL re-writing ability should be avoided whenever possible.
4770# Use the URL redirect form of response instead.
4771#
4772# Re-write creates a difference in the state held by the client
4773# and server. Possibly causing confusion when the server response
4774# contains snippets of its view state. Embeded URLs, response
4775# and content Location headers, etc. are not re-written by this
4776# interface.
4777#
4778# By default, a URL rewriter is not used.
4779#Default:
4780# none
4781
4782# TAG: url_rewrite_children
4783# Specifies the maximum number of redirector processes that Squid may
4784# spawn (numberofchildren) and several related options. Using too few of
4785# these helper processes (a.k.a. "helpers") creates request queues.
4786# Using too many helpers wastes your system resources.
4787#
4788# Usage: numberofchildren [option]...
4789#
4790# The startup= and idle= options allow some measure of skew in your
4791# tuning.
4792#
4793# startup=
4794#
4795# Sets a minimum of how many processes are to be spawned when Squid
4796# starts or reconfigures. When set to zero the first request will
4797# cause spawning of the first child process to handle it.
4798#
4799# Starting too few will cause an initial slowdown in traffic as Squid
4800# attempts to simultaneously spawn enough processes to cope.
4801#
4802# idle=
4803#
4804# Sets a minimum of how many processes Squid is to try and keep available
4805# at all times. When traffic begins to rise above what the existing
4806# processes can handle this many more will be spawned up to the maximum
4807# configured. A minimum setting of 1 is required.
4808#
4809# concurrency=
4810#
4811# The number of requests each redirector helper can handle in
4812# parallel. Defaults to 0 which indicates the redirector
4813# is a old-style single threaded redirector.
4814#
4815# When this directive is set to a value >= 1 then the protocol
4816# used to communicate with the helper is modified to include
4817# an ID in front of the request/response. The ID from the request
4818# must be echoed back with the response to that request.
4819#
4820# queue-size=N
4821#
4822# Sets the maximum number of queued requests. A request is queued when
4823# no existing child can accept it due to concurrency limit and no new
4824# child can be started due to numberofchildren limit. The default
4825# maximum is zero if url_rewrite_bypass is enabled and
4826# 2*numberofchildren otherwise. If the queued requests exceed queue size
4827# and redirector_bypass configuration option is set, then redirector is
4828# bypassed. Otherwise, Squid is allowed to temporarily exceed the
4829# configured maximum, marking the affected helper as "overloaded". If
4830# the helper overload lasts more than 3 minutes, the action prescribed
4831# by the on-persistent-overload option applies.
4832#
4833# on-persistent-overload=action
4834#
4835# Specifies Squid reaction to a new helper request arriving when the helper
4836# has been overloaded for more that 3 minutes already. The number of queued
4837# requests determines whether the helper is overloaded (see the queue-size
4838# option).
4839#
4840# Two actions are supported:
4841#
4842# die Squid worker quits. This is the default behavior.
4843#
4844# ERR Squid treats the helper request as if it was
4845# immediately submitted, and the helper immediately
4846# replied with an ERR response. This action has no effect
4847# on the already queued and in-progress helper requests.
4848#Default:
4849# url_rewrite_children 20 startup=0 idle=1 concurrency=0
4850
4851# TAG: url_rewrite_host_header
4852# To preserve same-origin security policies in browsers and
4853# prevent Host: header forgery by redirectors Squid rewrites
4854# any Host: header in redirected requests.
4855#
4856# If you are running an accelerator this may not be a wanted
4857# effect of a redirector. This directive enables you disable
4858# Host: alteration in reverse-proxy traffic.
4859#
4860# WARNING: Entries are cached on the result of the URL rewriting
4861# process, so be careful if you have domain-virtual hosts.
4862#
4863# WARNING: Squid and other software verifies the URL and Host
4864# are matching, so be careful not to relay through other proxies
4865# or inspecting firewalls with this disabled.
4866#Default:
4867# url_rewrite_host_header on
4868
4869# TAG: url_rewrite_access
4870# If defined, this access list specifies which requests are
4871# sent to the redirector processes.
4872#
4873# This clause supports both fast and slow acl types.
4874# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4875#Default:
4876# Allow, unless rules exist in squid.conf.
4877
4878# TAG: url_rewrite_bypass
4879# When this is 'on', a request will not go through the
4880# redirector if all the helpers are busy. If this is 'off' and the
4881# redirector queue grows too large, the action is prescribed by the
4882# on-persistent-overload option. You should only enable this if the
4883# redirectors are not critical to your caching system. If you use
4884# redirectors for access control, and you enable this option,
4885# users may have access to pages they should not
4886# be allowed to request.
4887#
4888# Enabling this option sets the default url_rewrite_children queue-size
4889# option value to 0.
4890#Default:
4891# url_rewrite_bypass off
4892
4893# TAG: url_rewrite_extras
4894# Specifies a string to be append to request line format for the
4895# rewriter helper. "Quoted" format values may contain spaces and
4896# logformat %macros. In theory, any logformat %macro can be used.
4897# In practice, a %macro expands as a dash (-) if the helper request is
4898# sent before the required macro information is available to Squid.
4899#Default:
4900# url_rewrite_extras "%>a/%>A %un %>rm myip=%la myport=%lp"
4901
4902# TAG: url_rewrite_timeout
4903# Squid times active requests to redirector. The timeout value and Squid
4904# reaction to a timed out request are configurable using the following
4905# format:
4906#
4907# url_rewrite_timeout timeout time-units on_timeout=<action> [response=<quoted-response>]
4908#
4909# supported timeout actions:
4910# fail Squid return a ERR_GATEWAY_FAILURE error page
4911#
4912# bypass Do not re-write the URL
4913#
4914# retry Send the lookup to the helper again
4915#
4916# use_configured_response
4917# Use the <quoted-response> as helper response
4918#Default:
4919# Squid waits for the helper response forever
4920
4921# OPTIONS FOR STORE ID
4922# -----------------------------------------------------------------------------
4923
4924# TAG: store_id_program
4925# Specify the location of the executable StoreID helper to use.
4926# Since they can perform almost any function there isn't one included.
4927#
4928# For each requested URL, the helper will receive one line with the format
4929#
4930# [channel-ID <SP>] URL [<SP> extras]<NL>
4931#
4932#
4933# After processing the request the helper must reply using the following format:
4934#
4935# [channel-ID <SP>] result [<SP> kv-pairs]
4936#
4937# The result code can be:
4938#
4939# OK store-id="..."
4940# Use the StoreID supplied in 'store-id='.
4941#
4942# ERR
4943# The default is to use HTTP request URL as the store ID.
4944#
4945# BH
4946# An internal error occurred in the helper, preventing
4947# a result being identified.
4948#
4949# In addition to the above kv-pairs Squid also understands the following
4950# optional kv-pairs received from URL rewriters:
4951# clt_conn_tag=TAG
4952# Associates a TAG with the client TCP connection.
4953# Please see url_rewrite_program related documentation for this
4954# kv-pair
4955#
4956# Helper programs should be prepared to receive and possibly ignore
4957# additional whitespace-separated tokens on each input line.
4958#
4959# When using the concurrency= option the protocol is changed by
4960# introducing a query channel tag in front of the request/response.
4961# The query channel tag is a number between 0 and concurrency-1.
4962# This value must be echoed back unchanged to Squid as the first part
4963# of the response relating to its request.
4964#
4965# NOTE: when using StoreID refresh_pattern will apply to the StoreID
4966# returned from the helper and not the URL.
4967#
4968# WARNING: Wrong StoreID value returned by a careless helper may result
4969# in the wrong cached response returned to the user.
4970#
4971# By default, a StoreID helper is not used.
4972#Default:
4973# none
4974
4975# TAG: store_id_extras
4976# Specifies a string to be append to request line format for the
4977# StoreId helper. "Quoted" format values may contain spaces and
4978# logformat %macros. In theory, any logformat %macro can be used.
4979# In practice, a %macro expands as a dash (-) if the helper request is
4980# sent before the required macro information is available to Squid.
4981#Default:
4982# store_id_extras "%>a/%>A %un %>rm myip=%la myport=%lp"
4983
4984# TAG: store_id_children
4985# Specifies the maximum number of StoreID helper processes that Squid
4986# may spawn (numberofchildren) and several related options. Using
4987# too few of these helper processes (a.k.a. "helpers") creates request
4988# queues. Using too many helpers wastes your system resources.
4989#
4990# Usage: numberofchildren [option]...
4991#
4992# The startup= and idle= options allow some measure of skew in your
4993# tuning.
4994#
4995# startup=
4996#
4997# Sets a minimum of how many processes are to be spawned when Squid
4998# starts or reconfigures. When set to zero the first request will
4999# cause spawning of the first child process to handle it.
5000#
5001# Starting too few will cause an initial slowdown in traffic as Squid
5002# attempts to simultaneously spawn enough processes to cope.
5003#
5004# idle=
5005#
5006# Sets a minimum of how many processes Squid is to try and keep available
5007# at all times. When traffic begins to rise above what the existing
5008# processes can handle this many more will be spawned up to the maximum
5009# configured. A minimum setting of 1 is required.
5010#
5011# concurrency=
5012#
5013# The number of requests each storeID helper can handle in
5014# parallel. Defaults to 0 which indicates the helper
5015# is a old-style single threaded program.
5016#
5017# When this directive is set to a value >= 1 then the protocol
5018# used to communicate with the helper is modified to include
5019# an ID in front of the request/response. The ID from the request
5020# must be echoed back with the response to that request.
5021#
5022# queue-size=N
5023#
5024# Sets the maximum number of queued requests to N. A request is queued
5025# when no existing child can accept it due to concurrency limit and no
5026# new child can be started due to numberofchildren limit. The default
5027# maximum is 2*numberofchildren. If the queued requests exceed queue
5028# size and redirector_bypass configuration option is set, then
5029# redirector is bypassed. Otherwise, Squid is allowed to temporarily
5030# exceed the configured maximum, marking the affected helper as
5031# "overloaded". If the helper overload lasts more than 3 minutes, the
5032# action prescribed by the on-persistent-overload option applies.
5033#
5034# on-persistent-overload=action
5035#
5036# Specifies Squid reaction to a new helper request arriving when the helper
5037# has been overloaded for more that 3 minutes already. The number of queued
5038# requests determines whether the helper is overloaded (see the queue-size
5039# option).
5040#
5041# Two actions are supported:
5042#
5043# die Squid worker quits. This is the default behavior.
5044#
5045# ERR Squid treats the helper request as if it was
5046# immediately submitted, and the helper immediately
5047# replied with an ERR response. This action has no effect
5048# on the already queued and in-progress helper requests.
5049#Default:
5050# store_id_children 20 startup=0 idle=1 concurrency=0
5051
5052# TAG: store_id_access
5053# If defined, this access list specifies which requests are
5054# sent to the StoreID processes. By default all requests
5055# are sent.
5056#
5057# This clause supports both fast and slow acl types.
5058# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5059#Default:
5060# Allow, unless rules exist in squid.conf.
5061
5062# TAG: store_id_bypass
5063# When this is 'on', a request will not go through the
5064# helper if all helpers are busy. If this is 'off' and the helper
5065# queue grows too large, the action is prescribed by the
5066# on-persistent-overload option. You should only enable this if the
5067# helpers are not critical to your caching system. If you use
5068# helpers for critical caching components, and you enable this
5069# option, users may not get objects from cache.
5070# This options sets default queue-size option of the store_id_children
5071# to 0.
5072#Default:
5073# store_id_bypass on
5074
5075# OPTIONS FOR TUNING THE CACHE
5076# -----------------------------------------------------------------------------
5077
5078# TAG: cache
5079# Requests denied by this directive will not be served from the cache
5080# and their responses will not be stored in the cache. This directive
5081# has no effect on other transactions and on already cached responses.
5082#
5083# This clause supports both fast and slow acl types.
5084# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5085#
5086# This and the two other similar caching directives listed below are
5087# checked at different transaction processing stages, have different
5088# access to response information, affect different cache operations,
5089# and differ in slow ACLs support:
5090#
5091# * cache: Checked before Squid makes a hit/miss determination.
5092# No access to reply information!
5093# Denies both serving a hit and storing a miss.
5094# Supports both fast and slow ACLs.
5095# * send_hit: Checked after a hit was detected.
5096# Has access to reply (hit) information.
5097# Denies serving a hit only.
5098# Supports fast ACLs only.
5099# * store_miss: Checked before storing a cachable miss.
5100# Has access to reply (miss) information.
5101# Denies storing a miss only.
5102# Supports fast ACLs only.
5103#
5104# If you are not sure which of the three directives to use, apply the
5105# following decision logic:
5106#
5107# * If your ACL(s) are of slow type _and_ need response info, redesign.
5108# Squid does not support that particular combination at this time.
5109# Otherwise:
5110# * If your directive ACL(s) are of slow type, use "cache"; and/or
5111# * if your directive ACL(s) need no response info, use "cache".
5112# Otherwise:
5113# * If you do not want the response cached, use store_miss; and/or
5114# * if you do not want a hit on a cached response, use send_hit.
5115#Default:
5116# By default, this directive is unused and has no effect.
5117
5118# TAG: send_hit
5119# Responses denied by this directive will not be served from the cache
5120# (but may still be cached, see store_miss). This directive has no
5121# effect on the responses it allows and on the cached objects.
5122#
5123# Please see the "cache" directive for a summary of differences among
5124# store_miss, send_hit, and cache directives.
5125#
5126# Unlike the "cache" directive, send_hit only supports fast acl
5127# types. See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5128#
5129# For example:
5130#
5131# # apply custom Store ID mapping to some URLs
5132# acl MapMe dstdomain .c.example.com
5133# store_id_program ...
5134# store_id_access allow MapMe
5135#
5136# # but prevent caching of special responses
5137# # such as 302 redirects that cause StoreID loops
5138# acl Ordinary http_status 200-299
5139# store_miss deny MapMe !Ordinary
5140#
5141# # and do not serve any previously stored special responses
5142# # from the cache (in case they were already cached before
5143# # the above store_miss rule was in effect).
5144# send_hit deny MapMe !Ordinary
5145#Default:
5146# By default, this directive is unused and has no effect.
5147
5148# TAG: store_miss
5149# Responses denied by this directive will not be cached (but may still
5150# be served from the cache, see send_hit). This directive has no
5151# effect on the responses it allows and on the already cached responses.
5152#
5153# Please see the "cache" directive for a summary of differences among
5154# store_miss, send_hit, and cache directives. See the
5155# send_hit directive for a usage example.
5156#
5157# Unlike the "cache" directive, store_miss only supports fast acl
5158# types. See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5159#Default:
5160# By default, this directive is unused and has no effect.
5161
5162# TAG: max_stale time-units
5163# This option puts an upper limit on how stale content Squid
5164# will serve from the cache if cache validation fails.
5165# Can be overriden by the refresh_pattern max-stale option.
5166#Default:
5167# max_stale 1 week
5168
5169# TAG: refresh_pattern
5170# usage: refresh_pattern [-i] regex min percent max [options]
5171#
5172# By default, regular expressions are CASE-SENSITIVE. To make
5173# them case-insensitive, use the -i option.
5174#
5175# 'Min' is the time (in minutes) an object without an explicit
5176# expiry time should be considered fresh. The recommended
5177# value is 0, any higher values may cause dynamic applications
5178# to be erroneously cached unless the application designer
5179# has taken the appropriate actions.
5180#
5181# 'Percent' is a percentage of the objects age (time since last
5182# modification age) an object without explicit expiry time
5183# will be considered fresh.
5184#
5185# 'Max' is an upper limit on how long objects without an explicit
5186# expiry time will be considered fresh. The value is also used
5187# to form Cache-Control: max-age header for a request sent from
5188# Squid to origin/parent.
5189#
5190# options: override-expire
5191# override-lastmod
5192# reload-into-ims
5193# ignore-reload
5194# ignore-no-store
5195# ignore-private
5196# max-stale=NN
5197# refresh-ims
5198# store-stale
5199#
5200# override-expire enforces min age even if the server
5201# sent an explicit expiry time (e.g., with the
5202# Expires: header or Cache-Control: max-age). Doing this
5203# VIOLATES the HTTP standard. Enabling this feature
5204# could make you liable for problems which it causes.
5205#
5206# Note: override-expire does not enforce staleness - it only extends
5207# freshness / min. If the server returns a Expires time which
5208# is longer than your max time, Squid will still consider
5209# the object fresh for that period of time.
5210#
5211# override-lastmod enforces min age even on objects
5212# that were modified recently.
5213#
5214# reload-into-ims changes a client no-cache or ``reload''
5215# request for a cached entry into a conditional request using
5216# If-Modified-Since and/or If-None-Match headers, provided the
5217# cached entry has a Last-Modified and/or a strong ETag header.
5218# Doing this VIOLATES the HTTP standard. Enabling this feature
5219# could make you liable for problems which it causes.
5220#
5221# ignore-reload ignores a client no-cache or ``reload''
5222# header. Doing this VIOLATES the HTTP standard. Enabling
5223# this feature could make you liable for problems which
5224# it causes.
5225#
5226# ignore-no-store ignores any ``Cache-control: no-store''
5227# headers received from a server. Doing this VIOLATES
5228# the HTTP standard. Enabling this feature could make you
5229# liable for problems which it causes.
5230#
5231# ignore-private ignores any ``Cache-control: private''
5232# headers received from a server. Doing this VIOLATES
5233# the HTTP standard. Enabling this feature could make you
5234# liable for problems which it causes.
5235#
5236# refresh-ims causes squid to contact the origin server
5237# when a client issues an If-Modified-Since request. This
5238# ensures that the client will receive an updated version
5239# if one is available.
5240#
5241# store-stale stores responses even if they don't have explicit
5242# freshness or a validator (i.e., Last-Modified or an ETag)
5243# present, or if they're already stale. By default, Squid will
5244# not cache such responses because they usually can't be
5245# reused. Note that such responses will be stale by default.
5246#
5247# max-stale=NN provide a maximum staleness factor. Squid won't
5248# serve objects more stale than this even if it failed to
5249# validate the object. Default: use the max_stale global limit.
5250#
5251# Basically a cached object is:
5252#
5253# FRESH if expire > now, else STALE
5254# STALE if age > max
5255# FRESH if lm-factor < percent, else STALE
5256# FRESH if age < min
5257# else STALE
5258#
5259# The refresh_pattern lines are checked in the order listed here.
5260# The first entry which matches is used. If none of the entries
5261# match the default will be used.
5262#
5263# Note, you must uncomment all the default lines if you want
5264# to change one. The default setting is only active if none is
5265# used.
5266#
5267#
5268
5269#
5270# Add any of your own refresh_pattern entries above these.
5271#
5272refresh_pattern ^ftp: 1440 20% 10080
5273refresh_pattern ^gopher: 1440 0% 1440
5274refresh_pattern -i (/cgi-bin/|\?) 0 0% 0
5275refresh_pattern . 0 20% 4320
5276
5277# TAG: quick_abort_min (KB)
5278#Default:
5279# quick_abort_min 16 KB
5280
5281# TAG: quick_abort_max (KB)
5282#Default:
5283# quick_abort_max 16 KB
5284
5285# TAG: quick_abort_pct (percent)
5286# The cache by default continues downloading aborted requests
5287# which are almost completed (less than 16 KB remaining). This
5288# may be undesirable on slow (e.g. SLIP) links and/or very busy
5289# caches. Impatient users may tie up file descriptors and
5290# bandwidth by repeatedly requesting and immediately aborting
5291# downloads.
5292#
5293# When the user aborts a request, Squid will check the
5294# quick_abort values to the amount of data transferred until
5295# then.
5296#
5297# If the transfer has less than 'quick_abort_min' KB remaining,
5298# it will finish the retrieval.
5299#
5300# If the transfer has more than 'quick_abort_max' KB remaining,
5301# it will abort the retrieval.
5302#
5303# If more than 'quick_abort_pct' of the transfer has completed,
5304# it will finish the retrieval.
5305#
5306# If you do not want any retrieval to continue after the client
5307# has aborted, set both 'quick_abort_min' and 'quick_abort_max'
5308# to '0 KB'.
5309#
5310# If you want retrievals to always continue if they are being
5311# cached set 'quick_abort_min' to '-1 KB'.
5312#Default:
5313# quick_abort_pct 95
5314
5315# TAG: read_ahead_gap buffer-size
5316# The amount of data the cache will buffer ahead of what has been
5317# sent to the client when retrieving an object from another server.
5318#Default:
5319# read_ahead_gap 16 KB
5320
5321# TAG: negative_ttl time-units
5322# Set the Default Time-to-Live (TTL) for failed requests.
5323# Certain types of failures (such as "connection refused" and
5324# "404 Not Found") are able to be negatively-cached for a short time.
5325# Modern web servers should provide Expires: header, however if they
5326# do not this can provide a minimum TTL.
5327# The default is not to cache errors with unknown expiry details.
5328#
5329# Note that this is different from negative caching of DNS lookups.
5330#
5331# WARNING: Doing this VIOLATES the HTTP standard. Enabling
5332# this feature could make you liable for problems which it
5333# causes.
5334#Default:
5335# negative_ttl 0 seconds
5336
5337# TAG: positive_dns_ttl time-units
5338# Upper limit on how long Squid will cache positive DNS responses.
5339# Default is 6 hours (360 minutes). This directive must be set
5340# larger than negative_dns_ttl.
5341#Default:
5342# positive_dns_ttl 6 hours
5343
5344# TAG: negative_dns_ttl time-units
5345# Time-to-Live (TTL) for negative caching of failed DNS lookups.
5346# This also sets the lower cache limit on positive lookups.
5347# Minimum value is 1 second, and it is not recommendable to go
5348# much below 10 seconds.
5349#Default:
5350# negative_dns_ttl 1 minutes
5351
5352# TAG: range_offset_limit size [acl acl...]
5353# usage: (size) [units] [[!]aclname]
5354#
5355# Sets an upper limit on how far (number of bytes) into the file
5356# a Range request may be to cause Squid to prefetch the whole file.
5357# If beyond this limit, Squid forwards the Range request as it is and
5358# the result is NOT cached.
5359#
5360# This is to stop a far ahead range request (lets say start at 17MB)
5361# from making Squid fetch the whole object up to that point before
5362# sending anything to the client.
5363#
5364# Multiple range_offset_limit lines may be specified, and they will
5365# be searched from top to bottom on each request until a match is found.
5366# The first match found will be used. If no line matches a request, the
5367# default limit of 0 bytes will be used.
5368#
5369# 'size' is the limit specified as a number of units.
5370#
5371# 'units' specifies whether to use bytes, KB, MB, etc.
5372# If no units are specified bytes are assumed.
5373#
5374# A size of 0 causes Squid to never fetch more than the
5375# client requested. (default)
5376#
5377# A size of 'none' causes Squid to always fetch the object from the
5378# beginning so it may cache the result. (2.0 style)
5379#
5380# 'aclname' is the name of a defined ACL.
5381#
5382# NP: Using 'none' as the byte value here will override any quick_abort settings
5383# that may otherwise apply to the range request. The range request will
5384# be fully fetched from start to finish regardless of the client
5385# actions. This affects bandwidth usage.
5386#Default:
5387# none
5388
5389# TAG: minimum_expiry_time (seconds)
5390# The minimum caching time according to (Expires - Date)
5391# headers Squid honors if the object can't be revalidated.
5392# The default is 60 seconds.
5393#
5394# In reverse proxy environments it might be desirable to honor
5395# shorter object lifetimes. It is most likely better to make
5396# your server return a meaningful Last-Modified header however.
5397#
5398# In ESI environments where page fragments often have short
5399# lifetimes, this will often be best set to 0.
5400#Default:
5401# minimum_expiry_time 60 seconds
5402
5403# TAG: store_avg_object_size (bytes)
5404# Average object size, used to estimate number of objects your
5405# cache can hold. The default is 13 KB.
5406#
5407# This is used to pre-seed the cache index memory allocation to
5408# reduce expensive reallocate operations while handling clients
5409# traffic. Too-large values may result in memory allocation during
5410# peak traffic, too-small values will result in wasted memory.
5411#
5412# Check the cache manager 'info' report metrics for the real
5413# object sizes seen by your Squid before tuning this.
5414#Default:
5415# store_avg_object_size 13 KB
5416
5417# TAG: store_objects_per_bucket
5418# Target number of objects per bucket in the store hash table.
5419# Lowering this value increases the total number of buckets and
5420# also the storage maintenance rate. The default is 20.
5421#Default:
5422# store_objects_per_bucket 20
5423
5424# HTTP OPTIONS
5425# -----------------------------------------------------------------------------
5426
5427# TAG: request_header_max_size (KB)
5428# This specifies the maximum size for HTTP headers in a request.
5429# Request headers are usually relatively small (about 512 bytes).
5430# Placing a limit on the request header size will catch certain
5431# bugs (for example with persistent connections) and possibly
5432# buffer-overflow or denial-of-service attacks.
5433#Default:
5434# request_header_max_size 64 KB
5435
5436# TAG: reply_header_max_size (KB)
5437# This specifies the maximum size for HTTP headers in a reply.
5438# Reply headers are usually relatively small (about 512 bytes).
5439# Placing a limit on the reply header size will catch certain
5440# bugs (for example with persistent connections) and possibly
5441# buffer-overflow or denial-of-service attacks.
5442#Default:
5443# reply_header_max_size 64 KB
5444
5445# TAG: request_body_max_size (bytes)
5446# This specifies the maximum size for an HTTP request body.
5447# In other words, the maximum size of a PUT/POST request.
5448# A user who attempts to send a request with a body larger
5449# than this limit receives an "Invalid Request" error message.
5450# If you set this parameter to a zero (the default), there will
5451# be no limit imposed.
5452#
5453# See also client_request_buffer_max_size for an alternative
5454# limitation on client uploads which can be configured.
5455#Default:
5456# No limit.
5457
5458# TAG: client_request_buffer_max_size (bytes)
5459# This specifies the maximum buffer size of a client request.
5460# It prevents squid eating too much memory when somebody uploads
5461# a large file.
5462#Default:
5463# client_request_buffer_max_size 512 KB
5464
5465# TAG: broken_posts
5466# A list of ACL elements which, if matched, causes Squid to send
5467# an extra CRLF pair after the body of a PUT/POST request.
5468#
5469# Some HTTP servers has broken implementations of PUT/POST,
5470# and rely on an extra CRLF pair sent by some WWW clients.
5471#
5472# Quote from RFC2616 section 4.1 on this matter:
5473#
5474# Note: certain buggy HTTP/1.0 client implementations generate an
5475# extra CRLF's after a POST request. To restate what is explicitly
5476# forbidden by the BNF, an HTTP/1.1 client must not preface or follow
5477# a request with an extra CRLF.
5478#
5479# This clause only supports fast acl types.
5480# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5481#
5482#Example:
5483# acl buggy_server url_regex ^http://....
5484# broken_posts allow buggy_server
5485#Default:
5486# Obey RFC 2616.
5487
5488# TAG: adaptation_uses_indirect_client on|off
5489# Controls whether the indirect client IP address (instead of the direct
5490# client IP address) is passed to adaptation services.
5491#
5492# See also: follow_x_forwarded_for adaptation_send_client_ip
5493#Default:
5494# adaptation_uses_indirect_client on
5495
5496# TAG: via on|off
5497# If set (default), Squid will include a Via header in requests and
5498# replies as required by RFC2616.
5499#Default:
5500# via on
5501
5502# TAG: vary_ignore_expire on|off
5503# Many HTTP servers supporting Vary gives such objects
5504# immediate expiry time with no cache-control header
5505# when requested by a HTTP/1.0 client. This option
5506# enables Squid to ignore such expiry times until
5507# HTTP/1.1 is fully implemented.
5508#
5509# WARNING: If turned on this may eventually cause some
5510# varying objects not intended for caching to get cached.
5511#Default:
5512# vary_ignore_expire off
5513
5514# TAG: request_entities
5515# Squid defaults to deny GET and HEAD requests with request entities,
5516# as the meaning of such requests are undefined in the HTTP standard
5517# even if not explicitly forbidden.
5518#
5519# Set this directive to on if you have clients which insists
5520# on sending request entities in GET or HEAD requests. But be warned
5521# that there is server software (both proxies and web servers) which
5522# can fail to properly process this kind of request which may make you
5523# vulnerable to cache pollution attacks if enabled.
5524#Default:
5525# request_entities off
5526
5527# TAG: request_header_access
5528# Usage: request_header_access header_name allow|deny [!]aclname ...
5529#
5530# WARNING: Doing this VIOLATES the HTTP standard. Enabling
5531# this feature could make you liable for problems which it
5532# causes.
5533#
5534# This option replaces the old 'anonymize_headers' and the
5535# older 'http_anonymizer' option with something that is much
5536# more configurable. A list of ACLs for each header name allows
5537# removal of specific header fields under specific conditions.
5538#
5539# This option only applies to outgoing HTTP request headers (i.e.,
5540# headers sent by Squid to the next HTTP hop such as a cache peer
5541# or an origin server). The option has no effect during cache hit
5542# detection. The equivalent adaptation vectoring point in ICAP
5543# terminology is post-cache REQMOD.
5544#
5545# The option is applied to individual outgoing request header
5546# fields. For each request header field F, Squid uses the first
5547# qualifying sets of request_header_access rules:
5548#
5549# 1. Rules with header_name equal to F's name.
5550# 2. Rules with header_name 'Other', provided F's name is not
5551# on the hard-coded list of commonly used HTTP header names.
5552# 3. Rules with header_name 'All'.
5553#
5554# Within that qualifying rule set, rule ACLs are checked as usual.
5555# If ACLs of an "allow" rule match, the header field is allowed to
5556# go through as is. If ACLs of a "deny" rule match, the header is
5557# removed and request_header_replace is then checked to identify
5558# if the removed header has a replacement. If no rules within the
5559# set have matching ACLs, the header field is left as is.
5560#
5561# For example, to achieve the same behavior as the old
5562# 'http_anonymizer standard' option, you should use:
5563#
5564# request_header_access From deny all
5565# request_header_access Referer deny all
5566# request_header_access User-Agent deny all
5567#
5568# Or, to reproduce the old 'http_anonymizer paranoid' feature
5569# you should use:
5570#
5571# request_header_access Authorization allow all
5572# request_header_access Proxy-Authorization allow all
5573# request_header_access Cache-Control allow all
5574# request_header_access Content-Length allow all
5575# request_header_access Content-Type allow all
5576# request_header_access Date allow all
5577# request_header_access Host allow all
5578# request_header_access If-Modified-Since allow all
5579# request_header_access Pragma allow all
5580# request_header_access Accept allow all
5581# request_header_access Accept-Charset allow all
5582# request_header_access Accept-Encoding allow all
5583# request_header_access Accept-Language allow all
5584# request_header_access Connection allow all
5585# request_header_access All deny all
5586#
5587# HTTP reply headers are controlled with the reply_header_access directive.
5588#
5589# By default, all headers are allowed (no anonymizing is performed).
5590#Default:
5591# No limits.
5592
5593# TAG: reply_header_access
5594# Usage: reply_header_access header_name allow|deny [!]aclname ...
5595#
5596# WARNING: Doing this VIOLATES the HTTP standard. Enabling
5597# this feature could make you liable for problems which it
5598# causes.
5599#
5600# This option only applies to reply headers, i.e., from the
5601# server to the client.
5602#
5603# This is the same as request_header_access, but in the other
5604# direction. Please see request_header_access for detailed
5605# documentation.
5606#
5607# For example, to achieve the same behavior as the old
5608# 'http_anonymizer standard' option, you should use:
5609#
5610# reply_header_access Server deny all
5611# reply_header_access WWW-Authenticate deny all
5612# reply_header_access Link deny all
5613#
5614# Or, to reproduce the old 'http_anonymizer paranoid' feature
5615# you should use:
5616#
5617# reply_header_access Allow allow all
5618# reply_header_access WWW-Authenticate allow all
5619# reply_header_access Proxy-Authenticate allow all
5620# reply_header_access Cache-Control allow all
5621# reply_header_access Content-Encoding allow all
5622# reply_header_access Content-Length allow all
5623# reply_header_access Content-Type allow all
5624# reply_header_access Date allow all
5625# reply_header_access Expires allow all
5626# reply_header_access Last-Modified allow all
5627# reply_header_access Location allow all
5628# reply_header_access Pragma allow all
5629# reply_header_access Content-Language allow all
5630# reply_header_access Retry-After allow all
5631# reply_header_access Title allow all
5632# reply_header_access Content-Disposition allow all
5633# reply_header_access Connection allow all
5634# reply_header_access All deny all
5635#
5636# HTTP request headers are controlled with the request_header_access directive.
5637#
5638# By default, all headers are allowed (no anonymizing is
5639# performed).
5640#Default:
5641# No limits.
5642
5643# TAG: request_header_replace
5644# Usage: request_header_replace header_name message
5645# Example: request_header_replace User-Agent Nutscrape/1.0 (CP/M; 8-bit)
5646#
5647# This option allows you to change the contents of headers
5648# denied with request_header_access above, by replacing them
5649# with some fixed string.
5650#
5651# This only applies to request headers, not reply headers.
5652#
5653# By default, headers are removed if denied.
5654#Default:
5655# none
5656
5657# TAG: reply_header_replace
5658# Usage: reply_header_replace header_name message
5659# Example: reply_header_replace Server Foo/1.0
5660#
5661# This option allows you to change the contents of headers
5662# denied with reply_header_access above, by replacing them
5663# with some fixed string.
5664#
5665# This only applies to reply headers, not request headers.
5666#
5667# By default, headers are removed if denied.
5668#Default:
5669# none
5670
5671# TAG: request_header_add
5672# Usage: request_header_add field-name field-value [ acl ... ]
5673# Example: request_header_add X-Client-CA "CA=%ssl::>cert_issuer" all
5674#
5675# This option adds header fields to outgoing HTTP requests (i.e.,
5676# request headers sent by Squid to the next HTTP hop such as a
5677# cache peer or an origin server). The option has no effect during
5678# cache hit detection. The equivalent adaptation vectoring point
5679# in ICAP terminology is post-cache REQMOD.
5680#
5681# Field-name is a token specifying an HTTP header name. If a
5682# standard HTTP header name is used, Squid does not check whether
5683# the new header conflicts with any existing headers or violates
5684# HTTP rules. If the request to be modified already contains a
5685# field with the same name, the old field is preserved but the
5686# header field values are not merged.
5687#
5688# Field-value is either a token or a quoted string. If quoted
5689# string format is used, then the surrounding quotes are removed
5690# while escape sequences and %macros are processed.
5691#
5692# One or more Squid ACLs may be specified to restrict header
5693# injection to matching requests. As always in squid.conf, all
5694# ACLs in the ACL list must be satisfied for the insertion to
5695# happen. The request_header_add supports fast ACLs only.
5696#
5697# See also: reply_header_add.
5698#Default:
5699# none
5700
5701# TAG: reply_header_add
5702# Usage: reply_header_add field-name field-value [ acl ... ]
5703# Example: reply_header_add X-Client-CA "CA=%ssl::>cert_issuer" all
5704#
5705# This option adds header fields to outgoing HTTP responses (i.e., response
5706# headers delivered by Squid to the client). This option has no effect on
5707# cache hit detection. The equivalent adaptation vectoring point in
5708# ICAP terminology is post-cache RESPMOD. This option does not apply to
5709# successful CONNECT replies.
5710#
5711# Field-name is a token specifying an HTTP header name. If a
5712# standard HTTP header name is used, Squid does not check whether
5713# the new header conflicts with any existing headers or violates
5714# HTTP rules. If the response to be modified already contains a
5715# field with the same name, the old field is preserved but the
5716# header field values are not merged.
5717#
5718# Field-value is either a token or a quoted string. If quoted
5719# string format is used, then the surrounding quotes are removed
5720# while escape sequences and %macros are processed.
5721#
5722# One or more Squid ACLs may be specified to restrict header
5723# injection to matching responses. As always in squid.conf, all
5724# ACLs in the ACL list must be satisfied for the insertion to
5725# happen. The reply_header_add option supports fast ACLs only.
5726#
5727# See also: request_header_add.
5728#Default:
5729# none
5730
5731# TAG: note
5732# This option used to log custom information about the master
5733# transaction. For example, an admin may configure Squid to log
5734# which "user group" the transaction belongs to, where "user group"
5735# will be determined based on a set of ACLs and not [just]
5736# authentication information.
5737# Values of key/value pairs can be logged using %{key}note macros:
5738#
5739# note key value acl ...
5740# logformat myFormat ... %{key}note ...
5741#Default:
5742# none
5743
5744# TAG: relaxed_header_parser on|off|warn
5745# In the default "on" setting Squid accepts certain forms
5746# of non-compliant HTTP messages where it is unambiguous
5747# what the sending application intended even if the message
5748# is not correctly formatted. The messages is then normalized
5749# to the correct form when forwarded by Squid.
5750#
5751# If set to "warn" then a warning will be emitted in cache.log
5752# each time such HTTP error is encountered.
5753#
5754# If set to "off" then such HTTP errors will cause the request
5755# or response to be rejected.
5756#Default:
5757# relaxed_header_parser on
5758
5759# TAG: collapsed_forwarding (on|off)
5760# This option controls whether Squid is allowed to merge multiple
5761# potentially cachable requests for the same URI before Squid knows
5762# whether the response is going to be cachable.
5763#
5764# When enabled, instead of forwarding each concurrent request for
5765# the same URL, Squid just sends the first of them. The other, so
5766# called "collapsed" requests, wait for the response to the first
5767# request and, if it happens to be cachable, use that response.
5768# Here, "concurrent requests" means "received after the first
5769# request headers were parsed and before the corresponding response
5770# headers were parsed".
5771#
5772# This feature is disabled by default: enabling collapsed
5773# forwarding needlessly delays forwarding requests that look
5774# cachable (when they are collapsed) but then need to be forwarded
5775# individually anyway because they end up being for uncachable
5776# content. However, in some cases, such as acceleration of highly
5777# cachable content with periodic or grouped expiration times, the
5778# gains from collapsing [large volumes of simultaneous refresh
5779# requests] outweigh losses from such delays.
5780#
5781# Squid collapses two kinds of requests: regular client requests
5782# received on one of the listening ports and internal "cache
5783# revalidation" requests which are triggered by those regular
5784# requests hitting a stale cached object. Revalidation collapsing
5785# is currently disabled for Squid instances containing SMP-aware
5786# disk or memory caches and for Vary-controlled cached objects.
5787#Default:
5788# collapsed_forwarding off
5789
5790# TAG: collapsed_forwarding_shared_entries_limit (number of entries)
5791# This limits the size of a table used for sharing information
5792# about collapsible entries among SMP workers. Limiting sharing
5793# too much results in cache content duplication and missed
5794# collapsing opportunities. Using excessively large values
5795# wastes shared memory.
5796#
5797# The limit should be significantly larger then the number of
5798# concurrent collapsible entries one wants to share. For a cache
5799# that handles less than 5000 concurrent requests, the default
5800# setting of 16384 should be plenty.
5801#
5802# If the limit is set to zero, it disables sharing of collapsed
5803# forwarding between SMP workers.
5804#Default:
5805# collapsed_forwarding_shared_entries_limit 16384
5806
5807# TIMEOUTS
5808# -----------------------------------------------------------------------------
5809
5810# TAG: forward_timeout time-units
5811# This parameter specifies how long Squid should at most attempt in
5812# finding a forwarding path for the request before giving up.
5813#Default:
5814# forward_timeout 4 minutes
5815
5816# TAG: connect_timeout time-units
5817# This parameter specifies how long to wait for the TCP connect to
5818# the requested server or peer to complete before Squid should
5819# attempt to find another path where to forward the request.
5820#Default:
5821# connect_timeout 1 minute
5822
5823# TAG: peer_connect_timeout time-units
5824# This parameter specifies how long to wait for a pending TCP
5825# connection to a peer cache. The default is 30 seconds. You
5826# may also set different timeout values for individual neighbors
5827# with the 'connect-timeout' option on a 'cache_peer' line.
5828#Default:
5829# peer_connect_timeout 30 seconds
5830
5831# TAG: read_timeout time-units
5832# Applied on peer server connections.
5833#
5834# After each successful read(), the timeout will be extended by this
5835# amount. If no data is read again after this amount of time,
5836# the request is aborted and logged with ERR_READ_TIMEOUT.
5837#
5838# The default is 15 minutes.
5839#Default:
5840# read_timeout 15 minutes
5841
5842# TAG: write_timeout time-units
5843# This timeout is tracked for all connections that have data
5844# available for writing and are waiting for the socket to become
5845# ready. After each successful write, the timeout is extended by
5846# the configured amount. If Squid has data to write but the
5847# connection is not ready for the configured duration, the
5848# transaction associated with the connection is terminated. The
5849# default is 15 minutes.
5850#Default:
5851# write_timeout 15 minutes
5852
5853# TAG: request_timeout
5854# How long to wait for complete HTTP request headers after initial
5855# connection establishment.
5856#Default:
5857# request_timeout 5 minutes
5858
5859# TAG: request_start_timeout
5860# How long to wait for the first request byte after initial
5861# connection establishment.
5862#Default:
5863# request_start_timeout 5 minutes
5864
5865# TAG: client_idle_pconn_timeout
5866# How long to wait for the next HTTP request on a persistent
5867# client connection after the previous request completes.
5868#Default:
5869# client_idle_pconn_timeout 2 minutes
5870
5871# TAG: ftp_client_idle_timeout
5872# How long to wait for an FTP request on a connection to Squid ftp_port.
5873# Many FTP clients do not deal with idle connection closures well,
5874# necessitating a longer default timeout than client_idle_pconn_timeout
5875# used for incoming HTTP requests.
5876#Default:
5877# ftp_client_idle_timeout 30 minutes
5878
5879# TAG: client_lifetime time-units
5880# The maximum amount of time a client (browser) is allowed to
5881# remain connected to the cache process. This protects the Cache
5882# from having a lot of sockets (and hence file descriptors) tied up
5883# in a CLOSE_WAIT state from remote clients that go away without
5884# properly shutting down (either because of a network failure or
5885# because of a poor client implementation). The default is one
5886# day, 1440 minutes.
5887#
5888# NOTE: The default value is intended to be much larger than any
5889# client would ever need to be connected to your cache. You
5890# should probably change client_lifetime only as a last resort.
5891# If you seem to have many client connections tying up
5892# filedescriptors, we recommend first tuning the read_timeout,
5893# request_timeout, persistent_request_timeout and quick_abort values.
5894#Default:
5895# client_lifetime 1 day
5896
5897# TAG: pconn_lifetime time-units
5898# Desired maximum lifetime of a persistent connection.
5899# When set, Squid will close a now-idle persistent connection that
5900# exceeded configured lifetime instead of moving the connection into
5901# the idle connection pool (or equivalent). No effect on ongoing/active
5902# transactions. Connection lifetime is the time period from the
5903# connection acceptance or opening time until "now".
5904#
5905# This limit is useful in environments with long-lived connections
5906# where Squid configuration or environmental factors change during a
5907# single connection lifetime. If unrestricted, some connections may
5908# last for hours and even days, ignoring those changes that should
5909# have affected their behavior or their existence.
5910#
5911# Currently, a new lifetime value supplied via Squid reconfiguration
5912# has no effect on already idle connections unless they become busy.
5913#
5914# When set to '0' this limit is not used.
5915#Default:
5916# pconn_lifetime 0 seconds
5917
5918# TAG: half_closed_clients
5919# Some clients may shutdown the sending side of their TCP
5920# connections, while leaving their receiving sides open. Sometimes,
5921# Squid can not tell the difference between a half-closed and a
5922# fully-closed TCP connection.
5923#
5924# By default, Squid will immediately close client connections when
5925# read(2) returns "no more data to read."
5926#
5927# Change this option to 'on' and Squid will keep open connections
5928# until a read(2) or write(2) on the socket returns an error.
5929# This may show some benefits for reverse proxies. But if not
5930# it is recommended to leave OFF.
5931#Default:
5932# half_closed_clients off
5933
5934# TAG: server_idle_pconn_timeout
5935# Timeout for idle persistent connections to servers and other
5936# proxies.
5937#Default:
5938# server_idle_pconn_timeout 1 minute
5939
5940# TAG: ident_timeout
5941# Maximum time to wait for IDENT lookups to complete.
5942#
5943# If this is too high, and you enabled IDENT lookups from untrusted
5944# users, you might be susceptible to denial-of-service by having
5945# many ident requests going at once.
5946#Default:
5947# ident_timeout 10 seconds
5948
5949# TAG: shutdown_lifetime time-units
5950# When SIGTERM or SIGHUP is received, the cache is put into
5951# "shutdown pending" mode until all active sockets are closed.
5952# This value is the lifetime to set for all open descriptors
5953# during shutdown mode. Any active clients after this many
5954# seconds will receive a 'timeout' message.
5955#Default:
5956# shutdown_lifetime 30 seconds
5957
5958# ADMINISTRATIVE PARAMETERS
5959# -----------------------------------------------------------------------------
5960
5961# TAG: cache_mgr
5962# Email-address of local cache manager who will receive
5963# mail if the cache dies. The default is "webmaster".
5964#Default:
5965# cache_mgr webmaster
5966
5967# TAG: mail_from
5968# From: email-address for mail sent when the cache dies.
5969# The default is to use 'squid@unique_hostname'.
5970#
5971# See also: unique_hostname directive.
5972#Default:
5973# none
5974
5975# TAG: mail_program
5976# Email program used to send mail if the cache dies.
5977# The default is "mail". The specified program must comply
5978# with the standard Unix mail syntax:
5979# mail-program recipient < mailfile
5980#
5981# Optional command line options can be specified.
5982#Default:
5983# mail_program mail
5984
5985# TAG: cache_effective_user
5986# If you start Squid as root, it will change its effective/real
5987# UID/GID to the user specified below. The default is to change
5988# to UID of proxy.
5989# see also; cache_effective_group
5990#Default:
5991# cache_effective_user proxy
5992
5993# TAG: cache_effective_group
5994# Squid sets the GID to the effective user's default group ID
5995# (taken from the password file) and supplementary group list
5996# from the groups membership.
5997#
5998# If you want Squid to run with a specific GID regardless of
5999# the group memberships of the effective user then set this
6000# to the group (or GID) you want Squid to run as. When set
6001# all other group privileges of the effective user are ignored
6002# and only this GID is effective. If Squid is not started as
6003# root the user starting Squid MUST be member of the specified
6004# group.
6005#
6006# This option is not recommended by the Squid Team.
6007# Our preference is for administrators to configure a secure
6008# user account for squid with UID/GID matching system policies.
6009#Default:
6010# Use system group memberships of the cache_effective_user account
6011
6012# TAG: httpd_suppress_version_string on|off
6013# Suppress Squid version string info in HTTP headers and HTML error pages.
6014#Default:
6015# httpd_suppress_version_string off
6016
6017# TAG: visible_hostname
6018# If you want to present a special hostname in error messages, etc,
6019# define this. Otherwise, the return value of gethostname()
6020# will be used. If you have multiple caches in a cluster and
6021# get errors about IP-forwarding you must set them to have individual
6022# names with this setting.
6023#Default:
6024# Automatically detect the system host name
6025
6026# TAG: unique_hostname
6027# If you want to have multiple machines with the same
6028# 'visible_hostname' you must give each machine a different
6029# 'unique_hostname' so forwarding loops can be detected.
6030#Default:
6031# Copy the value from visible_hostname
6032
6033# TAG: hostname_aliases
6034# A list of other DNS names your cache has.
6035#Default:
6036# none
6037
6038# TAG: umask
6039# Minimum umask which should be enforced while the proxy
6040# is running, in addition to the umask set at startup.
6041#
6042# For a traditional octal representation of umasks, start
6043# your value with 0.
6044#Default:
6045# umask 027
6046
6047# OPTIONS FOR THE CACHE REGISTRATION SERVICE
6048# -----------------------------------------------------------------------------
6049#
6050# This section contains parameters for the (optional) cache
6051# announcement service. This service is provided to help
6052# cache administrators locate one another in order to join or
6053# create cache hierarchies.
6054#
6055# An 'announcement' message is sent (via UDP) to the registration
6056# service by Squid. By default, the announcement message is NOT
6057# SENT unless you enable it with 'announce_period' below.
6058#
6059# The announcement message includes your hostname, plus the
6060# following information from this configuration file:
6061#
6062# http_port
6063# icp_port
6064# cache_mgr
6065#
6066# All current information is processed regularly and made
6067# available on the Web at http://www.ircache.net/Cache/Tracker/.
6068
6069# TAG: announce_period
6070# This is how frequently to send cache announcements.
6071#
6072# To enable announcing your cache, just set an announce period.
6073#
6074# Example:
6075# announce_period 1 day
6076#Default:
6077# Announcement messages disabled.
6078
6079# TAG: announce_host
6080# Set the hostname where announce registration messages will be sent.
6081#
6082# See also announce_port and announce_file
6083#Default:
6084# announce_host tracker.ircache.net
6085
6086# TAG: announce_file
6087# The contents of this file will be included in the announce
6088# registration messages.
6089#Default:
6090# none
6091
6092# TAG: announce_port
6093# Set the port where announce registration messages will be sent.
6094#
6095# See also announce_host and announce_file
6096#Default:
6097# announce_port 3131
6098
6099# HTTPD-ACCELERATOR OPTIONS
6100# -----------------------------------------------------------------------------
6101
6102# TAG: httpd_accel_surrogate_id
6103# Surrogates (http://www.esi.org/architecture_spec_1.0.html)
6104# need an identification token to allow control targeting. Because
6105# a farm of surrogates may all perform the same tasks, they may share
6106# an identification token.
6107#Default:
6108# visible_hostname is used if no specific ID is set.
6109
6110# TAG: http_accel_surrogate_remote on|off
6111# Remote surrogates (such as those in a CDN) honour the header
6112# "Surrogate-Control: no-store-remote".
6113#
6114# Set this to on to have squid behave as a remote surrogate.
6115#Default:
6116# http_accel_surrogate_remote off
6117
6118# TAG: esi_parser libxml2|expat
6119# Selects the XML parsing library to use when interpreting responses with
6120# Edge Side Includes.
6121#
6122# To disable ESI handling completely, ./configure Squid with --disable-esi.
6123#Default:
6124# Selects libxml2 if available at ./configure time or libexpat otherwise.
6125
6126# DELAY POOL PARAMETERS
6127# -----------------------------------------------------------------------------
6128
6129# TAG: delay_pools
6130# This represents the number of delay pools to be used. For example,
6131# if you have one class 2 delay pool and one class 3 delays pool, you
6132# have a total of 2 delay pools.
6133#
6134# See also delay_parameters, delay_class, delay_access for pool
6135# configuration details.
6136#Default:
6137# delay_pools 0
6138
6139# TAG: delay_class
6140# This defines the class of each delay pool. There must be exactly one
6141# delay_class line for each delay pool. For example, to define two
6142# delay pools, one of class 2 and one of class 3, the settings above
6143# and here would be:
6144#
6145# Example:
6146# delay_pools 4 # 4 delay pools
6147# delay_class 1 2 # pool 1 is a class 2 pool
6148# delay_class 2 3 # pool 2 is a class 3 pool
6149# delay_class 3 4 # pool 3 is a class 4 pool
6150# delay_class 4 5 # pool 4 is a class 5 pool
6151#
6152# The delay pool classes are:
6153#
6154# class 1 Everything is limited by a single aggregate
6155# bucket.
6156#
6157# class 2 Everything is limited by a single aggregate
6158# bucket as well as an "individual" bucket chosen
6159# from bits 25 through 32 of the IPv4 address.
6160#
6161# class 3 Everything is limited by a single aggregate
6162# bucket as well as a "network" bucket chosen
6163# from bits 17 through 24 of the IP address and a
6164# "individual" bucket chosen from bits 17 through
6165# 32 of the IPv4 address.
6166#
6167# class 4 Everything in a class 3 delay pool, with an
6168# additional limit on a per user basis. This
6169# only takes effect if the username is established
6170# in advance - by forcing authentication in your
6171# http_access rules.
6172#
6173# class 5 Requests are grouped according their tag (see
6174# external_acl's tag= reply).
6175#
6176#
6177# Each pool also requires a delay_parameters directive to configure the pool size
6178# and speed limits used whenever the pool is applied to a request. Along with
6179# a set of delay_access directives to determine when it is used.
6180#
6181# NOTE: If an IP address is a.b.c.d
6182# -> bits 25 through 32 are "d"
6183# -> bits 17 through 24 are "c"
6184# -> bits 17 through 32 are "c * 256 + d"
6185#
6186# NOTE-2: Due to the use of bitmasks in class 2,3,4 pools they only apply to
6187# IPv4 traffic. Class 1 and 5 pools may be used with IPv6 traffic.
6188#
6189# This clause only supports fast acl types.
6190# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
6191#
6192# See also delay_parameters and delay_access.
6193#Default:
6194# none
6195
6196# TAG: delay_access
6197# This is used to determine which delay pool a request falls into.
6198#
6199# delay_access is sorted per pool and the matching starts with pool 1,
6200# then pool 2, ..., and finally pool N. The first delay pool where the
6201# request is allowed is selected for the request. If it does not allow
6202# the request to any pool then the request is not delayed (default).
6203#
6204# For example, if you want some_big_clients in delay
6205# pool 1 and lotsa_little_clients in delay pool 2:
6206#
6207# delay_access 1 allow some_big_clients
6208# delay_access 1 deny all
6209# delay_access 2 allow lotsa_little_clients
6210# delay_access 2 deny all
6211# delay_access 3 allow authenticated_clients
6212#
6213# See also delay_parameters and delay_class.
6214#
6215#Default:
6216# Deny using the pool, unless allow rules exist in squid.conf for the pool.
6217
6218# TAG: delay_parameters
6219# This defines the parameters for a delay pool. Each delay pool has
6220# a number of "buckets" associated with it, as explained in the
6221# description of delay_class.
6222#
6223# For a class 1 delay pool, the syntax is:
6224# delay_class pool 1
6225# delay_parameters pool aggregate
6226#
6227# For a class 2 delay pool:
6228# delay_class pool 2
6229# delay_parameters pool aggregate individual
6230#
6231# For a class 3 delay pool:
6232# delay_class pool 3
6233# delay_parameters pool aggregate network individual
6234#
6235# For a class 4 delay pool:
6236# delay_class pool 4
6237# delay_parameters pool aggregate network individual user
6238#
6239# For a class 5 delay pool:
6240# delay_class pool 5
6241# delay_parameters pool tagrate
6242#
6243# The option variables are:
6244#
6245# pool a pool number - ie, a number between 1 and the
6246# number specified in delay_pools as used in
6247# delay_class lines.
6248#
6249# aggregate the speed limit parameters for the aggregate bucket
6250# (class 1, 2, 3).
6251#
6252# individual the speed limit parameters for the individual
6253# buckets (class 2, 3).
6254#
6255# network the speed limit parameters for the network buckets
6256# (class 3).
6257#
6258# user the speed limit parameters for the user buckets
6259# (class 4).
6260#
6261# tagrate the speed limit parameters for the tag buckets
6262# (class 5).
6263#
6264# A pair of delay parameters is written restore/maximum, where restore is
6265# the number of bytes (not bits - modem and network speeds are usually
6266# quoted in bits) per second placed into the bucket, and maximum is the
6267# maximum number of bytes which can be in the bucket at any time.
6268#
6269# There must be one delay_parameters line for each delay pool.
6270#
6271#
6272# For example, if delay pool number 1 is a class 2 delay pool as in the
6273# above example, and is being used to strictly limit each host to 64Kbit/sec
6274# (plus overheads), with no overall limit, the line is:
6275#
6276# delay_parameters 1 none 8000/8000
6277#
6278# Note that 8 x 8K Byte/sec -> 64K bit/sec.
6279#
6280# Note that the word 'none' is used to represent no limit.
6281#
6282#
6283# And, if delay pool number 2 is a class 3 delay pool as in the above
6284# example, and you want to limit it to a total of 256Kbit/sec (strict limit)
6285# with each 8-bit network permitted 64Kbit/sec (strict limit) and each
6286# individual host permitted 4800bit/sec with a bucket maximum size of 64Kbits
6287# to permit a decent web page to be downloaded at a decent speed
6288# (if the network is not being limited due to overuse) but slow down
6289# large downloads more significantly:
6290#
6291# delay_parameters 2 32000/32000 8000/8000 600/8000
6292#
6293# Note that 8 x 32K Byte/sec -> 256K bit/sec.
6294# 8 x 8K Byte/sec -> 64K bit/sec.
6295# 8 x 600 Byte/sec -> 4800 bit/sec.
6296#
6297#
6298# Finally, for a class 4 delay pool as in the example - each user will
6299# be limited to 128Kbits/sec no matter how many workstations they are logged into.:
6300#
6301# delay_parameters 4 32000/32000 8000/8000 600/64000 16000/16000
6302#
6303#
6304# See also delay_class and delay_access.
6305#
6306#Default:
6307# none
6308
6309# TAG: delay_initial_bucket_level (percent, 0-100)
6310# The initial bucket percentage is used to determine how much is put
6311# in each bucket when squid starts, is reconfigured, or first notices
6312# a host accessing it (in class 2 and class 3, individual hosts and
6313# networks only have buckets associated with them once they have been
6314# "seen" by squid).
6315#Default:
6316# delay_initial_bucket_level 50
6317
6318# CLIENT DELAY POOL PARAMETERS
6319# -----------------------------------------------------------------------------
6320
6321# TAG: client_delay_pools
6322# This option specifies the number of client delay pools used. It must
6323# preceed other client_delay_* options.
6324#
6325# Example:
6326# client_delay_pools 2
6327#
6328# See also client_delay_parameters and client_delay_access.
6329#Default:
6330# client_delay_pools 0
6331
6332# TAG: client_delay_initial_bucket_level (percent, 0-no_limit)
6333# This option determines the initial bucket size as a percentage of
6334# max_bucket_size from client_delay_parameters. Buckets are created
6335# at the time of the "first" connection from the matching IP. Idle
6336# buckets are periodically deleted up.
6337#
6338# You can specify more than 100 percent but note that such "oversized"
6339# buckets are not refilled until their size goes down to max_bucket_size
6340# from client_delay_parameters.
6341#
6342# Example:
6343# client_delay_initial_bucket_level 50
6344#Default:
6345# client_delay_initial_bucket_level 50
6346
6347# TAG: client_delay_parameters
6348#
6349# This option configures client-side bandwidth limits using the
6350# following format:
6351#
6352# client_delay_parameters pool speed_limit max_bucket_size
6353#
6354# pool is an integer ID used for client_delay_access matching.
6355#
6356# speed_limit is bytes added to the bucket per second.
6357#
6358# max_bucket_size is the maximum size of a bucket, enforced after any
6359# speed_limit additions.
6360#
6361# Please see the delay_parameters option for more information and
6362# examples.
6363#
6364# Example:
6365# client_delay_parameters 1 1024 2048
6366# client_delay_parameters 2 51200 16384
6367#
6368# See also client_delay_access.
6369#
6370#Default:
6371# none
6372
6373# TAG: client_delay_access
6374# This option determines the client-side delay pool for the
6375# request:
6376#
6377# client_delay_access pool_ID allow|deny acl_name
6378#
6379# All client_delay_access options are checked in their pool ID
6380# order, starting with pool 1. The first checked pool with allowed
6381# request is selected for the request. If no ACL matches or there
6382# are no client_delay_access options, the request bandwidth is not
6383# limited.
6384#
6385# The ACL-selected pool is then used to find the
6386# client_delay_parameters for the request. Client-side pools are
6387# not used to aggregate clients. Clients are always aggregated
6388# based on their source IP addresses (one bucket per source IP).
6389#
6390# This clause only supports fast acl types.
6391# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
6392# Additionally, only the client TCP connection details are available.
6393# ACLs testing HTTP properties will not work.
6394#
6395# Please see delay_access for more examples.
6396#
6397# Example:
6398# client_delay_access 1 allow low_rate_network
6399# client_delay_access 2 allow vips_network
6400#
6401#
6402# See also client_delay_parameters and client_delay_pools.
6403#Default:
6404# Deny use of the pool, unless allow rules exist in squid.conf for the pool.
6405
6406# WCCPv1 AND WCCPv2 CONFIGURATION OPTIONS
6407# -----------------------------------------------------------------------------
6408
6409# TAG: wccp_router
6410# Use this option to define your WCCP ``home'' router for
6411# Squid.
6412#
6413# wccp_router supports a single WCCP(v1) router
6414#
6415# wccp2_router supports multiple WCCPv2 routers
6416#
6417# only one of the two may be used at the same time and defines
6418# which version of WCCP to use.
6419#Default:
6420# WCCP disabled.
6421
6422# TAG: wccp2_router
6423# Use this option to define your WCCP ``home'' router for
6424# Squid.
6425#
6426# wccp_router supports a single WCCP(v1) router
6427#
6428# wccp2_router supports multiple WCCPv2 routers
6429#
6430# only one of the two may be used at the same time and defines
6431# which version of WCCP to use.
6432#Default:
6433# WCCPv2 disabled.
6434
6435# TAG: wccp_version
6436# This directive is only relevant if you need to set up WCCP(v1)
6437# to some very old and end-of-life Cisco routers. In all other
6438# setups it must be left unset or at the default setting.
6439# It defines an internal version in the WCCP(v1) protocol,
6440# with version 4 being the officially documented protocol.
6441#
6442# According to some users, Cisco IOS 11.2 and earlier only
6443# support WCCP version 3. If you're using that or an earlier
6444# version of IOS, you may need to change this value to 3, otherwise
6445# do not specify this parameter.
6446#Default:
6447# wccp_version 4
6448
6449# TAG: wccp2_rebuild_wait
6450# If this is enabled Squid will wait for the cache dir rebuild to finish
6451# before sending the first wccp2 HereIAm packet
6452#Default:
6453# wccp2_rebuild_wait on
6454
6455# TAG: wccp2_forwarding_method
6456# WCCP2 allows the setting of forwarding methods between the
6457# router/switch and the cache. Valid values are as follows:
6458#
6459# gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
6460# l2 - L2 redirect (forward the packet using Layer 2/MAC rewriting)
6461#
6462# Currently (as of IOS 12.4) cisco routers only support GRE.
6463# Cisco switches only support the L2 redirect assignment method.
6464#Default:
6465# wccp2_forwarding_method gre
6466
6467# TAG: wccp2_return_method
6468# WCCP2 allows the setting of return methods between the
6469# router/switch and the cache for packets that the cache
6470# decides not to handle. Valid values are as follows:
6471#
6472# gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
6473# l2 - L2 redirect (forward the packet using Layer 2/MAC rewriting)
6474#
6475# Currently (as of IOS 12.4) cisco routers only support GRE.
6476# Cisco switches only support the L2 redirect assignment.
6477#
6478# If the "ip wccp redirect exclude in" command has been
6479# enabled on the cache interface, then it is still safe for
6480# the proxy server to use a l2 redirect method even if this
6481# option is set to GRE.
6482#Default:
6483# wccp2_return_method gre
6484
6485# TAG: wccp2_assignment_method
6486# WCCP2 allows the setting of methods to assign the WCCP hash
6487# Valid values are as follows:
6488#
6489# hash - Hash assignment
6490# mask - Mask assignment
6491#
6492# As a general rule, cisco routers support the hash assignment method
6493# and cisco switches support the mask assignment method.
6494#Default:
6495# wccp2_assignment_method hash
6496
6497# TAG: wccp2_service
6498# WCCP2 allows for multiple traffic services. There are two
6499# types: "standard" and "dynamic". The standard type defines
6500# one service id - http (id 0). The dynamic service ids can be from
6501# 51 to 255 inclusive. In order to use a dynamic service id
6502# one must define the type of traffic to be redirected; this is done
6503# using the wccp2_service_info option.
6504#
6505# The "standard" type does not require a wccp2_service_info option,
6506# just specifying the service id will suffice.
6507#
6508# MD5 service authentication can be enabled by adding
6509# "password=<password>" to the end of this service declaration.
6510#
6511# Examples:
6512#
6513# wccp2_service standard 0 # for the 'web-cache' standard service
6514# wccp2_service dynamic 80 # a dynamic service type which will be
6515# # fleshed out with subsequent options.
6516# wccp2_service standard 0 password=foo
6517#Default:
6518# Use the 'web-cache' standard service.
6519
6520# TAG: wccp2_service_info
6521# Dynamic WCCPv2 services require further information to define the
6522# traffic you wish to have diverted.
6523#
6524# The format is:
6525#
6526# wccp2_service_info <id> protocol=<protocol> flags=<flag>,<flag>..
6527# priority=<priority> ports=<port>,<port>..
6528#
6529# The relevant WCCPv2 flags:
6530# + src_ip_hash, dst_ip_hash
6531# + source_port_hash, dst_port_hash
6532# + src_ip_alt_hash, dst_ip_alt_hash
6533# + src_port_alt_hash, dst_port_alt_hash
6534# + ports_source
6535#
6536# The port list can be one to eight entries.
6537#
6538# Example:
6539#
6540# wccp2_service_info 80 protocol=tcp flags=src_ip_hash,ports_source
6541# priority=240 ports=80
6542#
6543# Note: the service id must have been defined by a previous
6544# 'wccp2_service dynamic <id>' entry.
6545#Default:
6546# none
6547
6548# TAG: wccp2_weight
6549# Each cache server gets assigned a set of the destination
6550# hash proportional to their weight.
6551#Default:
6552# wccp2_weight 10000
6553
6554# TAG: wccp_address
6555# Use this option if you require WCCPv2 to use a specific
6556# interface address.
6557#
6558# The default behavior is to not bind to any specific address.
6559#Default:
6560# Address selected by the operating system.
6561
6562# TAG: wccp2_address
6563# Use this option if you require WCCP to use a specific
6564# interface address.
6565#
6566# The default behavior is to not bind to any specific address.
6567#Default:
6568# Address selected by the operating system.
6569
6570# PERSISTENT CONNECTION HANDLING
6571# -----------------------------------------------------------------------------
6572#
6573# Also see "pconn_timeout" in the TIMEOUTS section
6574
6575# TAG: client_persistent_connections
6576# Persistent connection support for clients.
6577# Squid uses persistent connections (when allowed). You can use
6578# this option to disable persistent connections with clients.
6579#Default:
6580# client_persistent_connections on
6581
6582# TAG: server_persistent_connections
6583# Persistent connection support for servers.
6584# Squid uses persistent connections (when allowed). You can use
6585# this option to disable persistent connections with servers.
6586#Default:
6587# server_persistent_connections on
6588
6589# TAG: persistent_connection_after_error
6590# With this directive the use of persistent connections after
6591# HTTP errors can be disabled. Useful if you have clients
6592# who fail to handle errors on persistent connections proper.
6593#Default:
6594# persistent_connection_after_error on
6595
6596# TAG: detect_broken_pconn
6597# Some servers have been found to incorrectly signal the use
6598# of HTTP/1.0 persistent connections even on replies not
6599# compatible, causing significant delays. This server problem
6600# has mostly been seen on redirects.
6601#
6602# By enabling this directive Squid attempts to detect such
6603# broken replies and automatically assume the reply is finished
6604# after 10 seconds timeout.
6605#Default:
6606# detect_broken_pconn off
6607
6608# CACHE DIGEST OPTIONS
6609# -----------------------------------------------------------------------------
6610
6611# TAG: digest_generation
6612# This controls whether the server will generate a Cache Digest
6613# of its contents. By default, Cache Digest generation is
6614# enabled if Squid is compiled with --enable-cache-digests defined.
6615#Default:
6616# digest_generation on
6617
6618# TAG: digest_bits_per_entry
6619# This is the number of bits of the server's Cache Digest which
6620# will be associated with the Digest entry for a given HTTP
6621# Method and URL (public key) combination. The default is 5.
6622#Default:
6623# digest_bits_per_entry 5
6624
6625# TAG: digest_rebuild_period (seconds)
6626# This is the wait time between Cache Digest rebuilds.
6627#Default:
6628# digest_rebuild_period 1 hour
6629
6630# TAG: digest_rewrite_period (seconds)
6631# This is the wait time between Cache Digest writes to
6632# disk.
6633#Default:
6634# digest_rewrite_period 1 hour
6635
6636# TAG: digest_swapout_chunk_size (bytes)
6637# This is the number of bytes of the Cache Digest to write to
6638# disk at a time. It defaults to 4096 bytes (4KB), the Squid
6639# default swap page.
6640#Default:
6641# digest_swapout_chunk_size 4096 bytes
6642
6643# TAG: digest_rebuild_chunk_percentage (percent, 0-100)
6644# This is the percentage of the Cache Digest to be scanned at a
6645# time. By default it is set to 10% of the Cache Digest.
6646#Default:
6647# digest_rebuild_chunk_percentage 10
6648
6649# SNMP OPTIONS
6650# -----------------------------------------------------------------------------
6651
6652# TAG: snmp_port
6653# The port number where Squid listens for SNMP requests. To enable
6654# SNMP support set this to a suitable port number. Port number
6655# 3401 is often used for the Squid SNMP agent. By default it's
6656# set to "0" (disabled)
6657#
6658# Example:
6659# snmp_port 3401
6660#Default:
6661# SNMP disabled.
6662
6663# TAG: snmp_access
6664# Allowing or denying access to the SNMP port.
6665#
6666# All access to the agent is denied by default.
6667# usage:
6668#
6669# snmp_access allow|deny [!]aclname ...
6670#
6671# This clause only supports fast acl types.
6672# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
6673#
6674#Example:
6675# snmp_access allow snmppublic localhost
6676# snmp_access deny all
6677#Default:
6678# Deny, unless rules exist in squid.conf.
6679
6680# TAG: snmp_incoming_address
6681# Just like 'udp_incoming_address', but for the SNMP port.
6682#
6683# snmp_incoming_address is used for the SNMP socket receiving
6684# messages from SNMP agents.
6685#
6686# The default snmp_incoming_address is to listen on all
6687# available network interfaces.
6688#Default:
6689# Accept SNMP packets from all machine interfaces.
6690
6691# TAG: snmp_outgoing_address
6692# Just like 'udp_outgoing_address', but for the SNMP port.
6693#
6694# snmp_outgoing_address is used for SNMP packets returned to SNMP
6695# agents.
6696#
6697# If snmp_outgoing_address is not set it will use the same socket
6698# as snmp_incoming_address. Only change this if you want to have
6699# SNMP replies sent using another address than where this Squid
6700# listens for SNMP queries.
6701#
6702# NOTE, snmp_incoming_address and snmp_outgoing_address can not have
6703# the same value since they both use the same port.
6704#Default:
6705# Use snmp_incoming_address or an address selected by the operating system.
6706
6707# ICP OPTIONS
6708# -----------------------------------------------------------------------------
6709
6710# TAG: icp_port
6711# The port number where Squid sends and receives ICP queries to
6712# and from neighbor caches. The standard UDP port for ICP is 3130.
6713#
6714# Example:
6715# icp_port 3130
6716#Default:
6717# ICP disabled.
6718
6719# TAG: htcp_port
6720# The port number where Squid sends and receives HTCP queries to
6721# and from neighbor caches. To turn it on you want to set it to
6722# 4827.
6723#
6724# Example:
6725# htcp_port 4827
6726#Default:
6727# HTCP disabled.
6728
6729# TAG: log_icp_queries on|off
6730# If set, ICP queries are logged to access.log. You may wish
6731# do disable this if your ICP load is VERY high to speed things
6732# up or to simplify log analysis.
6733#Default:
6734# log_icp_queries on
6735
6736# TAG: udp_incoming_address
6737# udp_incoming_address is used for UDP packets received from other
6738# caches.
6739#
6740# The default behavior is to not bind to any specific address.
6741#
6742# Only change this if you want to have all UDP queries received on
6743# a specific interface/address.
6744#
6745# NOTE: udp_incoming_address is used by the ICP, HTCP, and DNS
6746# modules. Altering it will affect all of them in the same manner.
6747#
6748# see also; udp_outgoing_address
6749#
6750# NOTE, udp_incoming_address and udp_outgoing_address can not
6751# have the same value since they both use the same port.
6752#Default:
6753# Accept packets from all machine interfaces.
6754
6755# TAG: udp_outgoing_address
6756# udp_outgoing_address is used for UDP packets sent out to other
6757# caches.
6758#
6759# The default behavior is to not bind to any specific address.
6760#
6761# Instead it will use the same socket as udp_incoming_address.
6762# Only change this if you want to have UDP queries sent using another
6763# address than where this Squid listens for UDP queries from other
6764# caches.
6765#
6766# NOTE: udp_outgoing_address is used by the ICP, HTCP, and DNS
6767# modules. Altering it will affect all of them in the same manner.
6768#
6769# see also; udp_incoming_address
6770#
6771# NOTE, udp_incoming_address and udp_outgoing_address can not
6772# have the same value since they both use the same port.
6773#Default:
6774# Use udp_incoming_address or an address selected by the operating system.
6775
6776# TAG: icp_hit_stale on|off
6777# If you want to return ICP_HIT for stale cache objects, set this
6778# option to 'on'. If you have sibling relationships with caches
6779# in other administrative domains, this should be 'off'. If you only
6780# have sibling relationships with caches under your control,
6781# it is probably okay to set this to 'on'.
6782# If set to 'on', your siblings should use the option "allow-miss"
6783# on their cache_peer lines for connecting to you.
6784#Default:
6785# icp_hit_stale off
6786
6787# TAG: minimum_direct_hops
6788# If using the ICMP pinging stuff, do direct fetches for sites
6789# which are no more than this many hops away.
6790#Default:
6791# minimum_direct_hops 4
6792
6793# TAG: minimum_direct_rtt (msec)
6794# If using the ICMP pinging stuff, do direct fetches for sites
6795# which are no more than this many rtt milliseconds away.
6796#Default:
6797# minimum_direct_rtt 400
6798
6799# TAG: netdb_low
6800# The low water mark for the ICMP measurement database.
6801#
6802# Note: high watermark controlled by netdb_high directive.
6803#
6804# These watermarks are counts, not percents. The defaults are
6805# (low) 900 and (high) 1000. When the high water mark is
6806# reached, database entries will be deleted until the low
6807# mark is reached.
6808#Default:
6809# netdb_low 900
6810
6811# TAG: netdb_high
6812# The high water mark for the ICMP measurement database.
6813#
6814# Note: low watermark controlled by netdb_low directive.
6815#
6816# These watermarks are counts, not percents. The defaults are
6817# (low) 900 and (high) 1000. When the high water mark is
6818# reached, database entries will be deleted until the low
6819# mark is reached.
6820#Default:
6821# netdb_high 1000
6822
6823# TAG: netdb_ping_period
6824# The minimum period for measuring a site. There will be at
6825# least this much delay between successive pings to the same
6826# network. The default is five minutes.
6827#Default:
6828# netdb_ping_period 5 minutes
6829
6830# TAG: query_icmp on|off
6831# If you want to ask your peers to include ICMP data in their ICP
6832# replies, enable this option.
6833#
6834# If your peer has configured Squid (during compilation) with
6835# '--enable-icmp' that peer will send ICMP pings to origin server
6836# sites of the URLs it receives. If you enable this option the
6837# ICP replies from that peer will include the ICMP data (if available).
6838# Then, when choosing a parent cache, Squid will choose the parent with
6839# the minimal RTT to the origin server. When this happens, the
6840# hierarchy field of the access.log will be
6841# "CLOSEST_PARENT_MISS". This option is off by default.
6842#Default:
6843# query_icmp off
6844
6845# TAG: test_reachability on|off
6846# When this is 'on', ICP MISS replies will be ICP_MISS_NOFETCH
6847# instead of ICP_MISS if the target host is NOT in the ICMP
6848# database, or has a zero RTT.
6849#Default:
6850# test_reachability off
6851
6852# TAG: icp_query_timeout (msec)
6853# Normally Squid will automatically determine an optimal ICP
6854# query timeout value based on the round-trip-time of recent ICP
6855# queries. If you want to override the value determined by
6856# Squid, set this 'icp_query_timeout' to a non-zero value. This
6857# value is specified in MILLISECONDS, so, to use a 2-second
6858# timeout (the old default), you would write:
6859#
6860# icp_query_timeout 2000
6861#Default:
6862# Dynamic detection.
6863
6864# TAG: maximum_icp_query_timeout (msec)
6865# Normally the ICP query timeout is determined dynamically. But
6866# sometimes it can lead to very large values (say 5 seconds).
6867# Use this option to put an upper limit on the dynamic timeout
6868# value. Do NOT use this option to always use a fixed (instead
6869# of a dynamic) timeout value. To set a fixed timeout see the
6870# 'icp_query_timeout' directive.
6871#Default:
6872# maximum_icp_query_timeout 2000
6873
6874# TAG: minimum_icp_query_timeout (msec)
6875# Normally the ICP query timeout is determined dynamically. But
6876# sometimes it can lead to very small timeouts, even lower than
6877# the normal latency variance on your link due to traffic.
6878# Use this option to put an lower limit on the dynamic timeout
6879# value. Do NOT use this option to always use a fixed (instead
6880# of a dynamic) timeout value. To set a fixed timeout see the
6881# 'icp_query_timeout' directive.
6882#Default:
6883# minimum_icp_query_timeout 5
6884
6885# TAG: background_ping_rate time-units
6886# Controls how often the ICP pings are sent to siblings that
6887# have background-ping set.
6888#Default:
6889# background_ping_rate 10 seconds
6890
6891# MULTICAST ICP OPTIONS
6892# -----------------------------------------------------------------------------
6893
6894# TAG: mcast_groups
6895# This tag specifies a list of multicast groups which your server
6896# should join to receive multicasted ICP queries.
6897#
6898# NOTE! Be very careful what you put here! Be sure you
6899# understand the difference between an ICP _query_ and an ICP
6900# _reply_. This option is to be set only if you want to RECEIVE
6901# multicast queries. Do NOT set this option to SEND multicast
6902# ICP (use cache_peer for that). ICP replies are always sent via
6903# unicast, so this option does not affect whether or not you will
6904# receive replies from multicast group members.
6905#
6906# You must be very careful to NOT use a multicast address which
6907# is already in use by another group of caches.
6908#
6909# If you are unsure about multicast, please read the Multicast
6910# chapter in the Squid FAQ (http://www.squid-cache.org/FAQ/).
6911#
6912# Usage: mcast_groups 239.128.16.128 224.0.1.20
6913#
6914# By default, Squid doesn't listen on any multicast groups.
6915#Default:
6916# none
6917
6918# TAG: mcast_miss_addr
6919# Note: This option is only available if Squid is rebuilt with the
6920# -DMULTICAST_MISS_STREAM define
6921#
6922# If you enable this option, every "cache miss" URL will
6923# be sent out on the specified multicast address.
6924#
6925# Do not enable this option unless you are are absolutely
6926# certain you understand what you are doing.
6927#Default:
6928# disabled.
6929
6930# TAG: mcast_miss_ttl
6931# Note: This option is only available if Squid is rebuilt with the
6932# -DMULTICAST_MISS_STREAM define
6933#
6934# This is the time-to-live value for packets multicasted
6935# when multicasting off cache miss URLs is enabled. By
6936# default this is set to 'site scope', i.e. 16.
6937#Default:
6938# mcast_miss_ttl 16
6939
6940# TAG: mcast_miss_port
6941# Note: This option is only available if Squid is rebuilt with the
6942# -DMULTICAST_MISS_STREAM define
6943#
6944# This is the port number to be used in conjunction with
6945# 'mcast_miss_addr'.
6946#Default:
6947# mcast_miss_port 3135
6948
6949# TAG: mcast_miss_encode_key
6950# Note: This option is only available if Squid is rebuilt with the
6951# -DMULTICAST_MISS_STREAM define
6952#
6953# The URLs that are sent in the multicast miss stream are
6954# encrypted. This is the encryption key.
6955#Default:
6956# mcast_miss_encode_key XXXXXXXXXXXXXXXX
6957
6958# TAG: mcast_icp_query_timeout (msec)
6959# For multicast peers, Squid regularly sends out ICP "probes" to
6960# count how many other peers are listening on the given multicast
6961# address. This value specifies how long Squid should wait to
6962# count all the replies. The default is 2000 msec, or 2
6963# seconds.
6964#Default:
6965# mcast_icp_query_timeout 2000
6966
6967# INTERNAL ICON OPTIONS
6968# -----------------------------------------------------------------------------
6969
6970# TAG: icon_directory
6971# Where the icons are stored. These are normally kept in
6972# /usr/share/squid/icons
6973#Default:
6974# icon_directory /usr/share/squid/icons
6975
6976# TAG: global_internal_static
6977# This directive controls is Squid should intercept all requests for
6978# /squid-internal-static/ no matter which host the URL is requesting
6979# (default on setting), or if nothing special should be done for
6980# such URLs (off setting). The purpose of this directive is to make
6981# icons etc work better in complex cache hierarchies where it may
6982# not always be possible for all corners in the cache mesh to reach
6983# the server generating a directory listing.
6984#Default:
6985# global_internal_static on
6986
6987# TAG: short_icon_urls
6988# If this is enabled Squid will use short URLs for icons.
6989# If disabled it will revert to the old behavior of including
6990# it's own name and port in the URL.
6991#
6992# If you run a complex cache hierarchy with a mix of Squid and
6993# other proxies you may need to disable this directive.
6994#Default:
6995# short_icon_urls on
6996
6997# ERROR PAGE OPTIONS
6998# -----------------------------------------------------------------------------
6999
7000# TAG: error_directory
7001# If you wish to create your own versions of the default
7002# error files to customize them to suit your company copy
7003# the error/template files to another directory and point
7004# this tag at them.
7005#
7006# WARNING: This option will disable multi-language support
7007# on error pages if used.
7008#
7009# The squid developers are interested in making squid available in
7010# a wide variety of languages. If you are making translations for a
7011# language that Squid does not currently provide please consider
7012# contributing your translation back to the project.
7013# http://wiki.squid-cache.org/Translations
7014#
7015# The squid developers working on translations are happy to supply drop-in
7016# translated error files in exchange for any new language contributions.
7017#Default:
7018# Send error pages in the clients preferred language
7019
7020# TAG: error_default_language
7021# Set the default language which squid will send error pages in
7022# if no existing translation matches the clients language
7023# preferences.
7024#
7025# If unset (default) generic English will be used.
7026#
7027# The squid developers are interested in making squid available in
7028# a wide variety of languages. If you are interested in making
7029# translations for any language see the squid wiki for details.
7030# http://wiki.squid-cache.org/Translations
7031#Default:
7032# Generate English language pages.
7033
7034# TAG: error_log_languages
7035# Log to cache.log what languages users are attempting to
7036# auto-negotiate for translations.
7037#
7038# Successful negotiations are not logged. Only failures
7039# have meaning to indicate that Squid may need an upgrade
7040# of its error page translations.
7041#Default:
7042# error_log_languages on
7043
7044# TAG: err_page_stylesheet
7045# CSS Stylesheet to pattern the display of Squid default error pages.
7046#
7047# For information on CSS see http://www.w3.org/Style/CSS/
7048#Default:
7049# err_page_stylesheet /etc/squid/errorpage.css
7050
7051# TAG: err_html_text
7052# HTML text to include in error messages. Make this a "mailto"
7053# URL to your admin address, or maybe just a link to your
7054# organizations Web page.
7055#
7056# To include this in your error messages, you must rewrite
7057# the error template files (found in the "errors" directory).
7058# Wherever you want the 'err_html_text' line to appear,
7059# insert a %L tag in the error template file.
7060#Default:
7061# none
7062
7063# TAG: email_err_data on|off
7064# If enabled, information about the occurred error will be
7065# included in the mailto links of the ERR pages (if %W is set)
7066# so that the email body contains the data.
7067# Syntax is <A HREF="mailto:%w%W">%w</A>
7068#Default:
7069# email_err_data on
7070
7071# TAG: deny_info
7072# Usage: deny_info err_page_name acl
7073# or deny_info http://... acl
7074# or deny_info TCP_RESET acl
7075#
7076# This can be used to return a ERR_ page for requests which
7077# do not pass the 'http_access' rules. Squid remembers the last
7078# acl it evaluated in http_access, and if a 'deny_info' line exists
7079# for that ACL Squid returns a corresponding error page.
7080#
7081# The acl is typically the last acl on the http_access deny line which
7082# denied access. The exceptions to this rule are:
7083# - When Squid needs to request authentication credentials. It's then
7084# the first authentication related acl encountered
7085# - When none of the http_access lines matches. It's then the last
7086# acl processed on the last http_access line.
7087# - When the decision to deny access was made by an adaptation service,
7088# the acl name is the corresponding eCAP or ICAP service_name.
7089#
7090# NP: If providing your own custom error pages with error_directory
7091# you may also specify them by your custom file name:
7092# Example: deny_info ERR_CUSTOM_ACCESS_DENIED bad_guys
7093#
7094# By defaut Squid will send "403 Forbidden". A different 4xx or 5xx
7095# may be specified by prefixing the file name with the code and a colon.
7096# e.g. 404:ERR_CUSTOM_ACCESS_DENIED
7097#
7098# Alternatively you can tell Squid to reset the TCP connection
7099# by specifying TCP_RESET.
7100#
7101# Or you can specify an error URL or URL pattern. The browsers will
7102# get redirected to the specified URL after formatting tags have
7103# been replaced. Redirect will be done with 302 or 307 according to
7104# HTTP/1.1 specs. A different 3xx code may be specified by prefixing
7105# the URL. e.g. 303:http://example.com/
7106#
7107# URL FORMAT TAGS:
7108# %a - username (if available. Password NOT included)
7109# %B - FTP path URL
7110# %e - Error number
7111# %E - Error description
7112# %h - Squid hostname
7113# %H - Request domain name
7114# %i - Client IP Address
7115# %M - Request Method
7116# %O - Unescaped message result from external ACL helper
7117# %o - Message result from external ACL helper
7118# %p - Request Port number
7119# %P - Request Protocol name
7120# %R - Request URL path
7121# %T - Timestamp in RFC 1123 format
7122# %U - Full canonical URL from client
7123# (HTTPS URLs terminate with *)
7124# %u - Full canonical URL from client
7125# %w - Admin email from squid.conf
7126# %x - Error name
7127# %% - Literal percent (%) code
7128#
7129#Default:
7130# none
7131
7132# OPTIONS INFLUENCING REQUEST FORWARDING
7133# -----------------------------------------------------------------------------
7134
7135# TAG: nonhierarchical_direct
7136# By default, Squid will send any non-hierarchical requests
7137# (not cacheable request type) direct to origin servers.
7138#
7139# When this is set to "off", Squid will prefer to send these
7140# requests to parents.
7141#
7142# Note that in most configurations, by turning this off you will only
7143# add latency to these request without any improvement in global hit
7144# ratio.
7145#
7146# This option only sets a preference. If the parent is unavailable a
7147# direct connection to the origin server may still be attempted. To
7148# completely prevent direct connections use never_direct.
7149#Default:
7150# nonhierarchical_direct on
7151
7152# TAG: prefer_direct
7153# Normally Squid tries to use parents for most requests. If you for some
7154# reason like it to first try going direct and only use a parent if
7155# going direct fails set this to on.
7156#
7157# By combining nonhierarchical_direct off and prefer_direct on you
7158# can set up Squid to use a parent as a backup path if going direct
7159# fails.
7160#
7161# Note: If you want Squid to use parents for all requests see
7162# the never_direct directive. prefer_direct only modifies how Squid
7163# acts on cacheable requests.
7164#Default:
7165# prefer_direct off
7166
7167# TAG: cache_miss_revalidate on|off
7168# RFC 7232 defines a conditional request mechanism to prevent
7169# response objects being unnecessarily transferred over the network.
7170# If that mechanism is used by the client and a cache MISS occurs
7171# it can prevent new cache entries being created.
7172#
7173# This option determines whether Squid on cache MISS will pass the
7174# client revalidation request to the server or tries to fetch new
7175# content for caching. It can be useful while the cache is mostly
7176# empty to more quickly have the cache populated by generating
7177# non-conditional GETs.
7178#
7179# When set to 'on' (default), Squid will pass all client If-* headers
7180# to the server. This permits server responses without a cacheable
7181# payload to be delivered and on MISS no new cache entry is created.
7182#
7183# When set to 'off' and if the request is cacheable, Squid will
7184# remove the clients If-Modified-Since and If-None-Match headers from
7185# the request sent to the server. This requests a 200 status response
7186# from the server to create a new cache entry with.
7187#Default:
7188# cache_miss_revalidate on
7189
7190# TAG: always_direct
7191# Usage: always_direct allow|deny [!]aclname ...
7192#
7193# Here you can use ACL elements to specify requests which should
7194# ALWAYS be forwarded by Squid to the origin servers without using
7195# any peers. For example, to always directly forward requests for
7196# local servers ignoring any parents or siblings you may have use
7197# something like:
7198#
7199# acl local-servers dstdomain my.domain.net
7200# always_direct allow local-servers
7201#
7202# To always forward FTP requests directly, use
7203#
7204# acl FTP proto FTP
7205# always_direct allow FTP
7206#
7207# NOTE: There is a similar, but opposite option named
7208# 'never_direct'. You need to be aware that "always_direct deny
7209# foo" is NOT the same thing as "never_direct allow foo". You
7210# may need to use a deny rule to exclude a more-specific case of
7211# some other rule. Example:
7212#
7213# acl local-external dstdomain external.foo.net
7214# acl local-servers dstdomain .foo.net
7215# always_direct deny local-external
7216# always_direct allow local-servers
7217#
7218# NOTE: If your goal is to make the client forward the request
7219# directly to the origin server bypassing Squid then this needs
7220# to be done in the client configuration. Squid configuration
7221# can only tell Squid how Squid should fetch the object.
7222#
7223# NOTE: This directive is not related to caching. The replies
7224# is cached as usual even if you use always_direct. To not cache
7225# the replies see the 'cache' directive.
7226#
7227# This clause supports both fast and slow acl types.
7228# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
7229#Default:
7230# Prevent any cache_peer being used for this request.
7231
7232# TAG: never_direct
7233# Usage: never_direct allow|deny [!]aclname ...
7234#
7235# never_direct is the opposite of always_direct. Please read
7236# the description for always_direct if you have not already.
7237#
7238# With 'never_direct' you can use ACL elements to specify
7239# requests which should NEVER be forwarded directly to origin
7240# servers. For example, to force the use of a proxy for all
7241# requests, except those in your local domain use something like:
7242#
7243# acl local-servers dstdomain .foo.net
7244# never_direct deny local-servers
7245# never_direct allow all
7246#
7247# or if Squid is inside a firewall and there are local intranet
7248# servers inside the firewall use something like:
7249#
7250# acl local-intranet dstdomain .foo.net
7251# acl local-external dstdomain external.foo.net
7252# always_direct deny local-external
7253# always_direct allow local-intranet
7254# never_direct allow all
7255#
7256# This clause supports both fast and slow acl types.
7257# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
7258#Default:
7259# Allow DNS results to be used for this request.
7260
7261# ADVANCED NETWORKING OPTIONS
7262# -----------------------------------------------------------------------------
7263
7264# TAG: incoming_udp_average
7265# Heavy voodoo here. I can't even believe you are reading this.
7266# Are you crazy? Don't even think about adjusting these unless
7267# you understand the algorithms in comm_select.c first!
7268#Default:
7269# incoming_udp_average 6
7270
7271# TAG: incoming_tcp_average
7272# Heavy voodoo here. I can't even believe you are reading this.
7273# Are you crazy? Don't even think about adjusting these unless
7274# you understand the algorithms in comm_select.c first!
7275#Default:
7276# incoming_tcp_average 4
7277
7278# TAG: incoming_dns_average
7279# Heavy voodoo here. I can't even believe you are reading this.
7280# Are you crazy? Don't even think about adjusting these unless
7281# you understand the algorithms in comm_select.c first!
7282#Default:
7283# incoming_dns_average 4
7284
7285# TAG: min_udp_poll_cnt
7286# Heavy voodoo here. I can't even believe you are reading this.
7287# Are you crazy? Don't even think about adjusting these unless
7288# you understand the algorithms in comm_select.c first!
7289#Default:
7290# min_udp_poll_cnt 8
7291
7292# TAG: min_dns_poll_cnt
7293# Heavy voodoo here. I can't even believe you are reading this.
7294# Are you crazy? Don't even think about adjusting these unless
7295# you understand the algorithms in comm_select.c first!
7296#Default:
7297# min_dns_poll_cnt 8
7298
7299# TAG: min_tcp_poll_cnt
7300# Heavy voodoo here. I can't even believe you are reading this.
7301# Are you crazy? Don't even think about adjusting these unless
7302# you understand the algorithms in comm_select.c first!
7303#Default:
7304# min_tcp_poll_cnt 8
7305
7306# TAG: accept_filter
7307# FreeBSD:
7308#
7309# The name of an accept(2) filter to install on Squid's
7310# listen socket(s). This feature is perhaps specific to
7311# FreeBSD and requires support in the kernel.
7312#
7313# The 'httpready' filter delays delivering new connections
7314# to Squid until a full HTTP request has been received.
7315# See the accf_http(9) man page for details.
7316#
7317# The 'dataready' filter delays delivering new connections
7318# to Squid until there is some data to process.
7319# See the accf_dataready(9) man page for details.
7320#
7321# Linux:
7322#
7323# The 'data' filter delays delivering of new connections
7324# to Squid until there is some data to process by TCP_ACCEPT_DEFER.
7325# You may optionally specify a number of seconds to wait by
7326# 'data=N' where N is the number of seconds. Defaults to 30
7327# if not specified. See the tcp(7) man page for details.
7328#EXAMPLE:
7329## FreeBSD
7330#accept_filter httpready
7331## Linux
7332#accept_filter data
7333#Default:
7334# none
7335
7336# TAG: client_ip_max_connections
7337# Set an absolute limit on the number of connections a single
7338# client IP can use. Any more than this and Squid will begin to drop
7339# new connections from the client until it closes some links.
7340#
7341# Note that this is a global limit. It affects all HTTP, HTCP, Gopher and FTP
7342# connections from the client. For finer control use the ACL access controls.
7343#
7344# Requires client_db to be enabled (the default).
7345#
7346# WARNING: This may noticably slow down traffic received via external proxies
7347# or NAT devices and cause them to rebound error messages back to their clients.
7348#Default:
7349# No limit.
7350
7351# TAG: tcp_recv_bufsize (bytes)
7352# Size of receive buffer to set for TCP sockets. Probably just
7353# as easy to change your kernel's default.
7354# Omit from squid.conf to use the default buffer size.
7355#Default:
7356# Use operating system TCP defaults.
7357
7358# ICAP OPTIONS
7359# -----------------------------------------------------------------------------
7360
7361# TAG: icap_enable on|off
7362# If you want to enable the ICAP module support, set this to on.
7363#Default:
7364# icap_enable off
7365
7366# TAG: icap_connect_timeout
7367# This parameter specifies how long to wait for the TCP connect to
7368# the requested ICAP server to complete before giving up and either
7369# terminating the HTTP transaction or bypassing the failure.
7370#
7371# The default for optional services is peer_connect_timeout.
7372# The default for essential services is connect_timeout.
7373# If this option is explicitly set, its value applies to all services.
7374#Default:
7375# none
7376
7377# TAG: icap_io_timeout time-units
7378# This parameter specifies how long to wait for an I/O activity on
7379# an established, active ICAP connection before giving up and
7380# either terminating the HTTP transaction or bypassing the
7381# failure.
7382#Default:
7383# Use read_timeout.
7384
7385# TAG: icap_service_failure_limit limit [in memory-depth time-units]
7386# The limit specifies the number of failures that Squid tolerates
7387# when establishing a new TCP connection with an ICAP service. If
7388# the number of failures exceeds the limit, the ICAP service is
7389# not used for new ICAP requests until it is time to refresh its
7390# OPTIONS.
7391#
7392# A negative value disables the limit. Without the limit, an ICAP
7393# service will not be considered down due to connectivity failures
7394# between ICAP OPTIONS requests.
7395#
7396# Squid forgets ICAP service failures older than the specified
7397# value of memory-depth. The memory fading algorithm
7398# is approximate because Squid does not remember individual
7399# errors but groups them instead, splitting the option
7400# value into ten time slots of equal length.
7401#
7402# When memory-depth is 0 and by default this option has no
7403# effect on service failure expiration.
7404#
7405# Squid always forgets failures when updating service settings
7406# using an ICAP OPTIONS transaction, regardless of this option
7407# setting.
7408#
7409# For example,
7410# # suspend service usage after 10 failures in 5 seconds:
7411# icap_service_failure_limit 10 in 5 seconds
7412#Default:
7413# icap_service_failure_limit 10
7414
7415# TAG: icap_service_revival_delay
7416# The delay specifies the number of seconds to wait after an ICAP
7417# OPTIONS request failure before requesting the options again. The
7418# failed ICAP service is considered "down" until fresh OPTIONS are
7419# fetched.
7420#
7421# The actual delay cannot be smaller than the hardcoded minimum
7422# delay of 30 seconds.
7423#Default:
7424# icap_service_revival_delay 180
7425
7426# TAG: icap_preview_enable on|off
7427# The ICAP Preview feature allows the ICAP server to handle the
7428# HTTP message by looking only at the beginning of the message body
7429# or even without receiving the body at all. In some environments,
7430# previews greatly speedup ICAP processing.
7431#
7432# During an ICAP OPTIONS transaction, the server may tell Squid what
7433# HTTP messages should be previewed and how big the preview should be.
7434# Squid will not use Preview if the server did not request one.
7435#
7436# To disable ICAP Preview for all ICAP services, regardless of
7437# individual ICAP server OPTIONS responses, set this option to "off".
7438#Example:
7439#icap_preview_enable off
7440#Default:
7441# icap_preview_enable on
7442
7443# TAG: icap_preview_size
7444# The default size of preview data to be sent to the ICAP server.
7445# This value might be overwritten on a per server basis by OPTIONS requests.
7446#Default:
7447# No preview sent.
7448
7449# TAG: icap_206_enable on|off
7450# 206 (Partial Content) responses is an ICAP extension that allows the
7451# ICAP agents to optionally combine adapted and original HTTP message
7452# content. The decision to combine is postponed until the end of the
7453# ICAP response. Squid supports Partial Content extension by default.
7454#
7455# Activation of the Partial Content extension is negotiated with each
7456# ICAP service during OPTIONS exchange. Most ICAP servers should handle
7457# negotation correctly even if they do not support the extension, but
7458# some might fail. To disable Partial Content support for all ICAP
7459# services and to avoid any negotiation, set this option to "off".
7460#
7461# Example:
7462# icap_206_enable off
7463#Default:
7464# icap_206_enable on
7465
7466# TAG: icap_default_options_ttl
7467# The default TTL value for ICAP OPTIONS responses that don't have
7468# an Options-TTL header.
7469#Default:
7470# icap_default_options_ttl 60
7471
7472# TAG: icap_persistent_connections on|off
7473# Whether or not Squid should use persistent connections to
7474# an ICAP server.
7475#Default:
7476# icap_persistent_connections on
7477
7478# TAG: adaptation_send_client_ip on|off
7479# If enabled, Squid shares HTTP client IP information with adaptation
7480# services. For ICAP, Squid adds the X-Client-IP header to ICAP requests.
7481# For eCAP, Squid sets the libecap::metaClientIp transaction option.
7482#
7483# See also: adaptation_uses_indirect_client
7484#Default:
7485# adaptation_send_client_ip off
7486
7487# TAG: adaptation_send_username on|off
7488# This sends authenticated HTTP client username (if available) to
7489# the adaptation service.
7490#
7491# For ICAP, the username value is encoded based on the
7492# icap_client_username_encode option and is sent using the header
7493# specified by the icap_client_username_header option.
7494#Default:
7495# adaptation_send_username off
7496
7497# TAG: icap_client_username_header
7498# ICAP request header name to use for adaptation_send_username.
7499#Default:
7500# icap_client_username_header X-Client-Username
7501
7502# TAG: icap_client_username_encode on|off
7503# Whether to base64 encode the authenticated client username.
7504#Default:
7505# icap_client_username_encode off
7506
7507# TAG: icap_service
7508# Defines a single ICAP service using the following format:
7509#
7510# icap_service id vectoring_point uri [option ...]
7511#
7512# id: ID
7513# an opaque identifier or name which is used to direct traffic to
7514# this specific service. Must be unique among all adaptation
7515# services in squid.conf.
7516#
7517# vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
7518# This specifies at which point of transaction processing the
7519# ICAP service should be activated. *_postcache vectoring points
7520# are not yet supported.
7521#
7522# uri: icap://servername:port/servicepath
7523# ICAP server and service location.
7524# icaps://servername:port/servicepath
7525# The "icap:" URI scheme is used for traditional ICAP server and
7526# service location (default port is 1344, connections are not
7527# encrypted). The "icaps:" URI scheme is for Secure ICAP
7528# services that use SSL/TLS-encrypted ICAP connections (by
7529# default, on port 11344).
7530#
7531# ICAP does not allow a single service to handle both REQMOD and RESPMOD
7532# transactions. Squid does not enforce that requirement. You can specify
7533# services with the same service_url and different vectoring_points. You
7534# can even specify multiple identical services as long as their
7535# service_names differ.
7536#
7537# To activate a service, use the adaptation_access directive. To group
7538# services, use adaptation_service_chain and adaptation_service_set.
7539#
7540# Service options are separated by white space. ICAP services support
7541# the following name=value options:
7542#
7543# bypass=on|off|1|0
7544# If set to 'on' or '1', the ICAP service is treated as
7545# optional. If the service cannot be reached or malfunctions,
7546# Squid will try to ignore any errors and process the message as
7547# if the service was not enabled. No all ICAP errors can be
7548# bypassed. If set to 0, the ICAP service is treated as
7549# essential and all ICAP errors will result in an error page
7550# returned to the HTTP client.
7551#
7552# Bypass is off by default: services are treated as essential.
7553#
7554# routing=on|off|1|0
7555# If set to 'on' or '1', the ICAP service is allowed to
7556# dynamically change the current message adaptation plan by
7557# returning a chain of services to be used next. The services
7558# are specified using the X-Next-Services ICAP response header
7559# value, formatted as a comma-separated list of service names.
7560# Each named service should be configured in squid.conf. Other
7561# services are ignored. An empty X-Next-Services value results
7562# in an empty plan which ends the current adaptation.
7563#
7564# Dynamic adaptation plan may cross or cover multiple supported
7565# vectoring points in their natural processing order.
7566#
7567# Routing is not allowed by default: the ICAP X-Next-Services
7568# response header is ignored.
7569#
7570# ipv6=on|off
7571# Only has effect on split-stack systems. The default on those systems
7572# is to use IPv4-only connections. When set to 'on' this option will
7573# make Squid use IPv6-only connections to contact this ICAP service.
7574#
7575# on-overload=block|bypass|wait|force
7576# If the service Max-Connections limit has been reached, do
7577# one of the following for each new ICAP transaction:
7578# * block: send an HTTP error response to the client
7579# * bypass: ignore the "over-connected" ICAP service
7580# * wait: wait (in a FIFO queue) for an ICAP connection slot
7581# * force: proceed, ignoring the Max-Connections limit
7582#
7583# In SMP mode with N workers, each worker assumes the service
7584# connection limit is Max-Connections/N, even though not all
7585# workers may use a given service.
7586#
7587# The default value is "bypass" if service is bypassable,
7588# otherwise it is set to "wait".
7589#
7590#
7591# max-conn=number
7592# Use the given number as the Max-Connections limit, regardless
7593# of the Max-Connections value given by the service, if any.
7594#
7595# connection-encryption=on|off
7596# Determines the ICAP service effect on the connections_encrypted
7597# ACL.
7598#
7599# The default is "on" for Secure ICAP services (i.e., those
7600# with the icaps:// service URIs scheme) and "off" for plain ICAP
7601# services.
7602#
7603# Does not affect ICAP connections (e.g., does not turn Secure
7604# ICAP on or off).
7605#
7606# ==== ICAPS / TLS OPTIONS ====
7607#
7608# These options are used for Secure ICAP (icaps://....) services only.
7609#
7610# tls-cert=/path/to/ssl/certificate
7611# A client X.509 certificate to use when connecting to
7612# this ICAP server.
7613#
7614# tls-key=/path/to/ssl/key
7615# The private key corresponding to the previous
7616# tls-cert= option.
7617#
7618# If tls-key= is not specified tls-cert= is assumed to
7619# reference a PEM file containing both the certificate
7620# and private key.
7621#
7622# tls-cipher=... The list of valid TLS/SSL ciphers to use when connecting
7623# to this icap server.
7624#
7625# tls-min-version=1.N
7626# The minimum TLS protocol version to permit. To control
7627# SSLv3 use the tls-options= parameter.
7628# Supported Values: 1.0 (default), 1.1, 1.2
7629#
7630# tls-options=... Specify various OpenSSL library options:
7631#
7632# NO_SSLv3 Disallow the use of SSLv3
7633#
7634# SINGLE_DH_USE
7635# Always create a new key when using
7636# temporary/ephemeral DH key exchanges
7637#
7638# ALL Enable various bug workarounds
7639# suggested as "harmless" by OpenSSL
7640# Be warned that this reduces SSL/TLS
7641# strength to some attacks.
7642#
7643# See the OpenSSL SSL_CTX_set_options documentation for a
7644# more complete list. Options relevant only to SSLv2 are
7645# not supported.
7646#
7647# tls-cafile= PEM file containing CA certificates to use when verifying
7648# the icap server certificate.
7649# Use to specify intermediate CA certificate(s) if not sent
7650# by the server. Or the full CA chain for the server when
7651# using the tls-default-ca=off flag.
7652# May be repeated to load multiple files.
7653#
7654# tls-capath=... A directory containing additional CA certificates to
7655# use when verifying the icap server certificate.
7656# Requires OpenSSL or LibreSSL.
7657#
7658# tls-crlfile=... A certificate revocation list file to use when
7659# verifying the icap server certificate.
7660#
7661# tls-flags=... Specify various flags modifying the Squid TLS implementation:
7662#
7663# DONT_VERIFY_PEER
7664# Accept certificates even if they fail to
7665# verify.
7666# DONT_VERIFY_DOMAIN
7667# Don't verify the icap server certificate
7668# matches the server name
7669#
7670# tls-default-ca[=off]
7671# Whether to use the system Trusted CAs. Default is ON.
7672#
7673# tls-domain= The icap server name as advertised in it's certificate.
7674# Used for verifying the correctness of the received icap
7675# server certificate. If not specified the icap server
7676# hostname extracted from ICAP URI will be used.
7677#
7678# Older icap_service format without optional named parameters is
7679# deprecated but supported for backward compatibility.
7680#
7681#Example:
7682#icap_service svcBlocker reqmod_precache icap://icap1.mydomain.net:1344/reqmod bypass=0
7683#icap_service svcLogger reqmod_precache icaps://icap2.mydomain.net:11344/reqmod routing=on
7684#Default:
7685# none
7686
7687# TAG: icap_class
7688# This deprecated option was documented to define an ICAP service
7689# chain, even though it actually defined a set of similar, redundant
7690# services, and the chains were not supported.
7691#
7692# To define a set of redundant services, please use the
7693# adaptation_service_set directive. For service chains, use
7694# adaptation_service_chain.
7695#Default:
7696# none
7697
7698# TAG: icap_access
7699# This option is deprecated. Please use adaptation_access, which
7700# has the same ICAP functionality, but comes with better
7701# documentation, and eCAP support.
7702#Default:
7703# none
7704
7705# eCAP OPTIONS
7706# -----------------------------------------------------------------------------
7707
7708# TAG: ecap_enable on|off
7709# Controls whether eCAP support is enabled.
7710#Default:
7711# ecap_enable off
7712
7713# TAG: ecap_service
7714# Defines a single eCAP service
7715#
7716# ecap_service id vectoring_point uri [option ...]
7717#
7718# id: ID
7719# an opaque identifier or name which is used to direct traffic to
7720# this specific service. Must be unique among all adaptation
7721# services in squid.conf.
7722#
7723# vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
7724# This specifies at which point of transaction processing the
7725# eCAP service should be activated. *_postcache vectoring points
7726# are not yet supported.
7727#
7728# uri: ecap://vendor/service_name?custom&cgi=style¶meters=optional
7729# Squid uses the eCAP service URI to match this configuration
7730# line with one of the dynamically loaded services. Each loaded
7731# eCAP service must have a unique URI. Obtain the right URI from
7732# the service provider.
7733#
7734# To activate a service, use the adaptation_access directive. To group
7735# services, use adaptation_service_chain and adaptation_service_set.
7736#
7737# Service options are separated by white space. eCAP services support
7738# the following name=value options:
7739#
7740# bypass=on|off|1|0
7741# If set to 'on' or '1', the eCAP service is treated as optional.
7742# If the service cannot be reached or malfunctions, Squid will try
7743# to ignore any errors and process the message as if the service
7744# was not enabled. No all eCAP errors can be bypassed.
7745# If set to 'off' or '0', the eCAP service is treated as essential
7746# and all eCAP errors will result in an error page returned to the
7747# HTTP client.
7748#
7749# Bypass is off by default: services are treated as essential.
7750#
7751# routing=on|off|1|0
7752# If set to 'on' or '1', the eCAP service is allowed to
7753# dynamically change the current message adaptation plan by
7754# returning a chain of services to be used next.
7755#
7756# Dynamic adaptation plan may cross or cover multiple supported
7757# vectoring points in their natural processing order.
7758#
7759# Routing is not allowed by default.
7760#
7761# connection-encryption=on|off
7762# Determines the eCAP service effect on the connections_encrypted
7763# ACL.
7764#
7765# Defaults to "on", which does not taint the master transaction
7766# w.r.t. that ACL.
7767#
7768# Does not affect eCAP API calls.
7769#
7770# Older ecap_service format without optional named parameters is
7771# deprecated but supported for backward compatibility.
7772#
7773#
7774#Example:
7775#ecap_service s1 reqmod_precache ecap://filters.R.us/leakDetector?on_error=block bypass=off
7776#ecap_service s2 respmod_precache ecap://filters.R.us/virusFilter config=/etc/vf.cfg bypass=on
7777#Default:
7778# none
7779
7780# TAG: loadable_modules
7781# Instructs Squid to load the specified dynamic module(s) or activate
7782# preloaded module(s).
7783#Example:
7784#loadable_modules /usr/lib/MinimalAdapter.so
7785#Default:
7786# none
7787
7788# MESSAGE ADAPTATION OPTIONS
7789# -----------------------------------------------------------------------------
7790
7791# TAG: adaptation_service_set
7792#
7793# Configures an ordered set of similar, redundant services. This is
7794# useful when hot standby or backup adaptation servers are available.
7795#
7796# adaptation_service_set set_name service_name1 service_name2 ...
7797#
7798# The named services are used in the set declaration order. The first
7799# applicable adaptation service from the set is used first. The next
7800# applicable service is tried if and only if the transaction with the
7801# previous service fails and the message waiting to be adapted is still
7802# intact.
7803#
7804# When adaptation starts, broken services are ignored as if they were
7805# not a part of the set. A broken service is a down optional service.
7806#
7807# The services in a set must be attached to the same vectoring point
7808# (e.g., pre-cache) and use the same adaptation method (e.g., REQMOD).
7809#
7810# If all services in a set are optional then adaptation failures are
7811# bypassable. If all services in the set are essential, then a
7812# transaction failure with one service may still be retried using
7813# another service from the set, but when all services fail, the master
7814# transaction fails as well.
7815#
7816# A set may contain a mix of optional and essential services, but that
7817# is likely to lead to surprising results because broken services become
7818# ignored (see above), making previously bypassable failures fatal.
7819# Technically, it is the bypassability of the last failed service that
7820# matters.
7821#
7822# See also: adaptation_access adaptation_service_chain
7823#
7824#Example:
7825#adaptation_service_set svcBlocker urlFilterPrimary urlFilterBackup
7826#adaptation service_set svcLogger loggerLocal loggerRemote
7827#Default:
7828# none
7829
7830# TAG: adaptation_service_chain
7831#
7832# Configures a list of complementary services that will be applied
7833# one-by-one, forming an adaptation chain or pipeline. This is useful
7834# when Squid must perform different adaptations on the same message.
7835#
7836# adaptation_service_chain chain_name service_name1 svc_name2 ...
7837#
7838# The named services are used in the chain declaration order. The first
7839# applicable adaptation service from the chain is used first. The next
7840# applicable service is applied to the successful adaptation results of
7841# the previous service in the chain.
7842#
7843# When adaptation starts, broken services are ignored as if they were
7844# not a part of the chain. A broken service is a down optional service.
7845#
7846# Request satisfaction terminates the adaptation chain because Squid
7847# does not currently allow declaration of RESPMOD services at the
7848# "reqmod_precache" vectoring point (see icap_service or ecap_service).
7849#
7850# The services in a chain must be attached to the same vectoring point
7851# (e.g., pre-cache) and use the same adaptation method (e.g., REQMOD).
7852#
7853# A chain may contain a mix of optional and essential services. If an
7854# essential adaptation fails (or the failure cannot be bypassed for
7855# other reasons), the master transaction fails. Otherwise, the failure
7856# is bypassed as if the failed adaptation service was not in the chain.
7857#
7858# See also: adaptation_access adaptation_service_set
7859#
7860#Example:
7861#adaptation_service_chain svcRequest requestLogger urlFilter leakDetector
7862#Default:
7863# none
7864
7865# TAG: adaptation_access
7866# Sends an HTTP transaction to an ICAP or eCAP adaptation service.
7867#
7868# adaptation_access service_name allow|deny [!]aclname...
7869# adaptation_access set_name allow|deny [!]aclname...
7870#
7871# At each supported vectoring point, the adaptation_access
7872# statements are processed in the order they appear in this
7873# configuration file. Statements pointing to the following services
7874# are ignored (i.e., skipped without checking their ACL):
7875#
7876# - services serving different vectoring points
7877# - "broken-but-bypassable" services
7878# - "up" services configured to ignore such transactions
7879# (e.g., based on the ICAP Transfer-Ignore header).
7880#
7881# When a set_name is used, all services in the set are checked
7882# using the same rules, to find the first applicable one. See
7883# adaptation_service_set for details.
7884#
7885# If an access list is checked and there is a match, the
7886# processing stops: For an "allow" rule, the corresponding
7887# adaptation service is used for the transaction. For a "deny"
7888# rule, no adaptation service is activated.
7889#
7890# It is currently not possible to apply more than one adaptation
7891# service at the same vectoring point to the same HTTP transaction.
7892#
7893# See also: icap_service and ecap_service
7894#
7895#Example:
7896#adaptation_access service_1 allow all
7897#Default:
7898# Allow, unless rules exist in squid.conf.
7899
7900# TAG: adaptation_service_iteration_limit
7901# Limits the number of iterations allowed when applying adaptation
7902# services to a message. If your longest adaptation set or chain
7903# may have more than 16 services, increase the limit beyond its
7904# default value of 16. If detecting infinite iteration loops sooner
7905# is critical, make the iteration limit match the actual number
7906# of services in your longest adaptation set or chain.
7907#
7908# Infinite adaptation loops are most likely with routing services.
7909#
7910# See also: icap_service routing=1
7911#Default:
7912# adaptation_service_iteration_limit 16
7913
7914# TAG: adaptation_masterx_shared_names
7915# For each master transaction (i.e., the HTTP request and response
7916# sequence, including all related ICAP and eCAP exchanges), Squid
7917# maintains a table of metadata. The table entries are (name, value)
7918# pairs shared among eCAP and ICAP exchanges. The table is destroyed
7919# with the master transaction.
7920#
7921# This option specifies the table entry names that Squid must accept
7922# from and forward to the adaptation transactions.
7923#
7924# An ICAP REQMOD or RESPMOD transaction may set an entry in the
7925# shared table by returning an ICAP header field with a name
7926# specified in adaptation_masterx_shared_names.
7927#
7928# An eCAP REQMOD or RESPMOD transaction may set an entry in the
7929# shared table by implementing the libecap::visitEachOption() API
7930# to provide an option with a name specified in
7931# adaptation_masterx_shared_names.
7932#
7933# Squid will store and forward the set entry to subsequent adaptation
7934# transactions within the same master transaction scope.
7935#
7936# Only one shared entry name is supported at this time.
7937#
7938#Example:
7939## share authentication information among ICAP services
7940#adaptation_masterx_shared_names X-Subscriber-ID
7941#Default:
7942# none
7943
7944# TAG: adaptation_meta
7945# This option allows Squid administrator to add custom ICAP request
7946# headers or eCAP options to Squid ICAP requests or eCAP transactions.
7947# Use it to pass custom authentication tokens and other
7948# transaction-state related meta information to an ICAP/eCAP service.
7949#
7950# The addition of a meta header is ACL-driven:
7951# adaptation_meta name value [!]aclname ...
7952#
7953# Processing for a given header name stops after the first ACL list match.
7954# Thus, it is impossible to add two headers with the same name. If no ACL
7955# lists match for a given header name, no such header is added. For
7956# example:
7957#
7958# # do not debug transactions except for those that need debugging
7959# adaptation_meta X-Debug 1 needs_debugging
7960#
7961# # log all transactions except for those that must remain secret
7962# adaptation_meta X-Log 1 !keep_secret
7963#
7964# # mark transactions from users in the "G 1" group
7965# adaptation_meta X-Authenticated-Groups "G 1" authed_as_G1
7966#
7967# The "value" parameter may be a regular squid.conf token or a "double
7968# quoted string". Within the quoted string, use backslash (\) to escape
7969# any character, which is currently only useful for escaping backslashes
7970# and double quotes. For example,
7971# "this string has one backslash (\\) and two \"quotes\""
7972#
7973# Used adaptation_meta header values may be logged via %note
7974# logformat code. If multiple adaptation_meta headers with the same name
7975# are used during master transaction lifetime, the header values are
7976# logged in the order they were used and duplicate values are ignored
7977# (only the first repeated value will be logged).
7978#Default:
7979# none
7980
7981# TAG: icap_retry
7982# This ACL determines which retriable ICAP transactions are
7983# retried. Transactions that received a complete ICAP response
7984# and did not have to consume or produce HTTP bodies to receive
7985# that response are usually retriable.
7986#
7987# icap_retry allow|deny [!]aclname ...
7988#
7989# Squid automatically retries some ICAP I/O timeouts and errors
7990# due to persistent connection race conditions.
7991#
7992# See also: icap_retry_limit
7993#Default:
7994# icap_retry deny all
7995
7996# TAG: icap_retry_limit
7997# Limits the number of retries allowed.
7998#
7999# Communication errors due to persistent connection race
8000# conditions are unavoidable, automatically retried, and do not
8001# count against this limit.
8002#
8003# See also: icap_retry
8004#Default:
8005# No retries are allowed.
8006
8007# DNS OPTIONS
8008# -----------------------------------------------------------------------------
8009
8010# TAG: check_hostnames
8011# For security and stability reasons Squid can check
8012# hostnames for Internet standard RFC compliance. If you want
8013# Squid to perform these checks turn this directive on.
8014#Default:
8015# check_hostnames off
8016
8017# TAG: allow_underscore
8018# Underscore characters is not strictly allowed in Internet hostnames
8019# but nevertheless used by many sites. Set this to off if you want
8020# Squid to be strict about the standard.
8021# This check is performed only when check_hostnames is set to on.
8022#Default:
8023# allow_underscore on
8024
8025# TAG: dns_retransmit_interval
8026# Initial retransmit interval for DNS queries. The interval is
8027# doubled each time all configured DNS servers have been tried.
8028#Default:
8029# dns_retransmit_interval 5 seconds
8030
8031# TAG: dns_timeout
8032# DNS Query timeout. If no response is received to a DNS query
8033# within this time all DNS servers for the queried domain
8034# are assumed to be unavailable.
8035#Default:
8036# dns_timeout 30 seconds
8037
8038# TAG: dns_packet_max
8039# Maximum number of bytes packet size to advertise via EDNS.
8040# Set to "none" to disable EDNS large packet support.
8041#
8042# For legacy reasons DNS UDP replies will default to 512 bytes which
8043# is too small for many responses. EDNS provides a means for Squid to
8044# negotiate receiving larger responses back immediately without having
8045# to failover with repeat requests. Responses larger than this limit
8046# will retain the old behaviour of failover to TCP DNS.
8047#
8048# Squid has no real fixed limit internally, but allowing packet sizes
8049# over 1500 bytes requires network jumbogram support and is usually not
8050# necessary.
8051#
8052# WARNING: The RFC also indicates that some older resolvers will reply
8053# with failure of the whole request if the extension is added. Some
8054# resolvers have already been identified which will reply with mangled
8055# EDNS response on occasion. Usually in response to many-KB jumbogram
8056# sizes being advertised by Squid.
8057# Squid will currently treat these both as an unable-to-resolve domain
8058# even if it would be resolvable without EDNS.
8059#Default:
8060# EDNS disabled
8061
8062# TAG: dns_defnames on|off
8063# Normally the RES_DEFNAMES resolver option is disabled
8064# (see res_init(3)). This prevents caches in a hierarchy
8065# from interpreting single-component hostnames locally. To allow
8066# Squid to handle single-component names, enable this option.
8067#Default:
8068# Search for single-label domain names is disabled.
8069
8070# TAG: dns_multicast_local on|off
8071# When set to on, Squid sends multicast DNS lookups on the local
8072# network for domains ending in .local and .arpa.
8073# This enables local servers and devices to be contacted in an
8074# ad-hoc or zero-configuration network environment.
8075#Default:
8076# Search for .local and .arpa names is disabled.
8077
8078# TAG: dns_nameservers
8079# Use this if you want to specify a list of DNS name servers
8080# (IP addresses) to use instead of those given in your
8081# /etc/resolv.conf file.
8082#
8083# On Windows platforms, if no value is specified here or in
8084# the /etc/resolv.conf file, the list of DNS name servers are
8085# taken from the Windows registry, both static and dynamic DHCP
8086# configurations are supported.
8087#
8088# Example: dns_nameservers 10.0.0.1 192.172.0.4
8089#Default:
8090# Use operating system definitions
8091
8092# TAG: hosts_file
8093# Location of the host-local IP name-address associations
8094# database. Most Operating Systems have such a file on different
8095# default locations:
8096# - Un*X & Linux: /etc/hosts
8097# - Windows NT/2000: %SystemRoot%\system32\drivers\etc\hosts
8098# (%SystemRoot% value install default is c:\winnt)
8099# - Windows XP/2003: %SystemRoot%\system32\drivers\etc\hosts
8100# (%SystemRoot% value install default is c:\windows)
8101# - Windows 9x/Me: %windir%\hosts
8102# (%windir% value is usually c:\windows)
8103# - Cygwin: /etc/hosts
8104#
8105# The file contains newline-separated definitions, in the
8106# form ip_address_in_dotted_form name [name ...] names are
8107# whitespace-separated. Lines beginning with an hash (#)
8108# character are comments.
8109#
8110# The file is checked at startup and upon configuration.
8111# If set to 'none', it won't be checked.
8112# If append_domain is used, that domain will be added to
8113# domain-local (i.e. not containing any dot character) host
8114# definitions.
8115#Default:
8116# hosts_file /etc/hosts
8117
8118# TAG: append_domain
8119# Appends local domain name to hostnames without any dots in
8120# them. append_domain must begin with a period.
8121#
8122# Be warned there are now Internet names with no dots in
8123# them using only top-domain names, so setting this may
8124# cause some Internet sites to become unavailable.
8125#
8126#Example:
8127# append_domain .yourdomain.com
8128#Default:
8129# Use operating system definitions
8130
8131# TAG: ignore_unknown_nameservers
8132# By default Squid checks that DNS responses are received
8133# from the same IP addresses they are sent to. If they
8134# don't match, Squid ignores the response and writes a warning
8135# message to cache.log. You can allow responses from unknown
8136# nameservers by setting this option to 'off'.
8137#Default:
8138# ignore_unknown_nameservers on
8139
8140# TAG: dns_v4_first
8141# With the IPv6 Internet being as fast or faster than IPv4 Internet
8142# for most networks Squid prefers to contact websites over IPv6.
8143#
8144# This option reverses the order of preference to make Squid contact
8145# dual-stack websites over IPv4 first. Squid will still perform both
8146# IPv6 and IPv4 DNS lookups before connecting.
8147#
8148# WARNING:
8149# This option will restrict the situations under which IPv6
8150# connectivity is used (and tested), potentially hiding network
8151# problems which would otherwise be detected and warned about.
8152#Default:
8153# dns_v4_first off
8154
8155# TAG: ipcache_size (number of entries)
8156# Maximum number of DNS IP cache entries.
8157#Default:
8158# ipcache_size 1024
8159
8160# TAG: ipcache_low (percent)
8161#Default:
8162# ipcache_low 90
8163
8164# TAG: ipcache_high (percent)
8165# The size, low-, and high-water marks for the IP cache.
8166#Default:
8167# ipcache_high 95
8168
8169# TAG: fqdncache_size (number of entries)
8170# Maximum number of FQDN cache entries.
8171#Default:
8172# fqdncache_size 1024
8173
8174# MISCELLANEOUS
8175# -----------------------------------------------------------------------------
8176
8177# TAG: configuration_includes_quoted_values on|off
8178# If set, Squid will recognize each "quoted string" after a configuration
8179# directive as a single parameter. The quotes are stripped before the
8180# parameter value is interpreted or used.
8181# See "Values with spaces, quotes, and other special characters"
8182# section for more details.
8183#Default:
8184# configuration_includes_quoted_values off
8185
8186# TAG: memory_pools on|off
8187# If set, Squid will keep pools of allocated (but unused) memory
8188# available for future use. If memory is a premium on your
8189# system and you believe your malloc library outperforms Squid
8190# routines, disable this.
8191#Default:
8192# memory_pools on
8193
8194# TAG: memory_pools_limit (bytes)
8195# Used only with memory_pools on:
8196# memory_pools_limit 50 MB
8197#
8198# If set to a non-zero value, Squid will keep at most the specified
8199# limit of allocated (but unused) memory in memory pools. All free()
8200# requests that exceed this limit will be handled by your malloc
8201# library. Squid does not pre-allocate any memory, just safe-keeps
8202# objects that otherwise would be free()d. Thus, it is safe to set
8203# memory_pools_limit to a reasonably high value even if your
8204# configuration will use less memory.
8205#
8206# If set to none, Squid will keep all memory it can. That is, there
8207# will be no limit on the total amount of memory used for safe-keeping.
8208#
8209# To disable memory allocation optimization, do not set
8210# memory_pools_limit to 0 or none. Set memory_pools to "off" instead.
8211#
8212# An overhead for maintaining memory pools is not taken into account
8213# when the limit is checked. This overhead is close to four bytes per
8214# object kept. However, pools may actually _save_ memory because of
8215# reduced memory thrashing in your malloc library.
8216#Default:
8217# memory_pools_limit 5 MB
8218
8219# TAG: forwarded_for on|off|transparent|truncate|delete
8220# If set to "on", Squid will append your client's IP address
8221# in the HTTP requests it forwards. By default it looks like:
8222#
8223# X-Forwarded-For: 192.1.2.3
8224#
8225# If set to "off", it will appear as
8226#
8227# X-Forwarded-For: unknown
8228#
8229# If set to "transparent", Squid will not alter the
8230# X-Forwarded-For header in any way.
8231#
8232# If set to "delete", Squid will delete the entire
8233# X-Forwarded-For header.
8234#
8235# If set to "truncate", Squid will remove all existing
8236# X-Forwarded-For entries, and place the client IP as the sole entry.
8237#Default:
8238# forwarded_for on
8239
8240# TAG: cachemgr_passwd
8241# Specify passwords for cachemgr operations.
8242#
8243# Usage: cachemgr_passwd password action action ...
8244#
8245# Some valid actions are (see cache manager menu for a full list):
8246# 5min
8247# 60min
8248# asndb
8249# authenticator
8250# cbdata
8251# client_list
8252# comm_incoming
8253# config *
8254# counters
8255# delay
8256# digest_stats
8257# dns
8258# events
8259# filedescriptors
8260# fqdncache
8261# histograms
8262# http_headers
8263# info
8264# io
8265# ipcache
8266# mem
8267# menu
8268# netdb
8269# non_peers
8270# objects
8271# offline_toggle *
8272# pconn
8273# peer_select
8274# reconfigure *
8275# redirector
8276# refresh
8277# server_list
8278# shutdown *
8279# store_digest
8280# storedir
8281# utilization
8282# via_headers
8283# vm_objects
8284#
8285# * Indicates actions which will not be performed without a
8286# valid password, others can be performed if not listed here.
8287#
8288# To disable an action, set the password to "disable".
8289# To allow performing an action without a password, set the
8290# password to "none".
8291#
8292# Use the keyword "all" to set the same password for all actions.
8293#
8294#Example:
8295# cachemgr_passwd secret shutdown
8296# cachemgr_passwd lesssssssecret info stats/objects
8297# cachemgr_passwd disable all
8298#Default:
8299# No password. Actions which require password are denied.
8300
8301# TAG: client_db on|off
8302# If you want to disable collecting per-client statistics,
8303# turn off client_db here.
8304#Default:
8305# client_db on
8306
8307# TAG: refresh_all_ims on|off
8308# When you enable this option, squid will always check
8309# the origin server for an update when a client sends an
8310# If-Modified-Since request. Many browsers use IMS
8311# requests when the user requests a reload, and this
8312# ensures those clients receive the latest version.
8313#
8314# By default (off), squid may return a Not Modified response
8315# based on the age of the cached version.
8316#Default:
8317# refresh_all_ims off
8318
8319# TAG: reload_into_ims on|off
8320# When you enable this option, client no-cache or ``reload''
8321# requests will be changed to If-Modified-Since requests.
8322# Doing this VIOLATES the HTTP standard. Enabling this
8323# feature could make you liable for problems which it
8324# causes.
8325#
8326# see also refresh_pattern for a more selective approach.
8327#Default:
8328# reload_into_ims off
8329
8330# TAG: connect_retries
8331# Limits the number of reopening attempts when establishing a single
8332# TCP connection. All these attempts must still complete before the
8333# applicable connection opening timeout expires.
8334#
8335# By default and when connect_retries is set to zero, Squid does not
8336# retry failed connection opening attempts.
8337#
8338# The (not recommended) maximum is 10 tries. An attempt to configure a
8339# higher value results in the value of 10 being used (with a warning).
8340#
8341# Squid may open connections to retry various high-level forwarding
8342# failures. For an outside observer, that activity may look like a
8343# low-level connection reopening attempt, but those high-level retries
8344# are governed by forward_max_tries instead.
8345#
8346# See also: connect_timeout, forward_timeout, icap_connect_timeout,
8347# ident_timeout, and forward_max_tries.
8348#Default:
8349# Do not retry failed connections.
8350
8351# TAG: retry_on_error
8352# If set to ON Squid will automatically retry requests when
8353# receiving an error response with status 403 (Forbidden),
8354# 500 (Internal Error), 501 or 503 (Service not available).
8355# Status 502 and 504 (Gateway errors) are always retried.
8356#
8357# This is mainly useful if you are in a complex cache hierarchy to
8358# work around access control errors.
8359#
8360# NOTE: This retry will attempt to find another working destination.
8361# Which is different from the server which just failed.
8362#Default:
8363# retry_on_error off
8364
8365# TAG: as_whois_server
8366# WHOIS server to query for AS numbers. NOTE: AS numbers are
8367# queried only when Squid starts up, not for every request.
8368#Default:
8369# as_whois_server whois.ra.net
8370
8371# TAG: offline_mode
8372# Enable this option and Squid will never try to validate cached
8373# objects.
8374#Default:
8375# offline_mode off
8376
8377# TAG: uri_whitespace
8378# What to do with requests that have whitespace characters in the
8379# URI. Options:
8380#
8381# strip: The whitespace characters are stripped out of the URL.
8382# This is the behavior recommended by RFC2396 and RFC3986
8383# for tolerant handling of generic URI.
8384# NOTE: This is one difference between generic URI and HTTP URLs.
8385#
8386# deny: The request is denied. The user receives an "Invalid
8387# Request" message.
8388# This is the behaviour recommended by RFC2616 for safe
8389# handling of HTTP request URL.
8390#
8391# allow: The request is allowed and the URI is not changed. The
8392# whitespace characters remain in the URI. Note the
8393# whitespace is passed to redirector processes if they
8394# are in use.
8395# Note this may be considered a violation of RFC2616
8396# request parsing where whitespace is prohibited in the
8397# URL field.
8398#
8399# encode: The request is allowed and the whitespace characters are
8400# encoded according to RFC1738.
8401#
8402# chop: The request is allowed and the URI is chopped at the
8403# first whitespace.
8404#
8405#
8406# NOTE the current Squid implementation of encode and chop violates
8407# RFC2616 by not using a 301 redirect after altering the URL.
8408#Default:
8409# uri_whitespace strip
8410
8411# TAG: chroot
8412# Specifies a directory where Squid should do a chroot() while
8413# initializing. This also causes Squid to fully drop root
8414# privileges after initializing. This means, for example, if you
8415# use a HTTP port less than 1024 and try to reconfigure, you may
8416# get an error saying that Squid can not open the port.
8417#Default:
8418# none
8419
8420# TAG: pipeline_prefetch
8421# HTTP clients may send a pipeline of 1+N requests to Squid using a
8422# single connection, without waiting for Squid to respond to the first
8423# of those requests. This option limits the number of concurrent
8424# requests Squid will try to handle in parallel. If set to N, Squid
8425# will try to receive and process up to 1+N requests on the same
8426# connection concurrently.
8427#
8428# Defaults to 0 (off) for bandwidth management and access logging
8429# reasons.
8430#
8431# NOTE: pipelining requires persistent connections to clients.
8432#
8433# WARNING: pipelining breaks NTLM and Negotiate/Kerberos authentication.
8434#Default:
8435# Do not pre-parse pipelined requests.
8436
8437# TAG: high_response_time_warning (msec)
8438# If the one-minute median response time exceeds this value,
8439# Squid prints a WARNING with debug level 0 to get the
8440# administrators attention. The value is in milliseconds.
8441#Default:
8442# disabled.
8443
8444# TAG: high_page_fault_warning
8445# If the one-minute average page fault rate exceeds this
8446# value, Squid prints a WARNING with debug level 0 to get
8447# the administrators attention. The value is in page faults
8448# per second.
8449#Default:
8450# disabled.
8451
8452# TAG: high_memory_warning
8453# Note: This option is only available if Squid is rebuilt with the
8454# GNU Malloc with mstats()
8455#
8456# If the memory usage (as determined by gnumalloc, if available and used)
8457# exceeds this amount, Squid prints a WARNING with debug level 0 to get
8458# the administrators attention.
8459#Default:
8460# disabled.
8461
8462# TAG: sleep_after_fork (microseconds)
8463# When this is set to a non-zero value, the main Squid process
8464# sleeps the specified number of microseconds after a fork()
8465# system call. This sleep may help the situation where your
8466# system reports fork() failures due to lack of (virtual)
8467# memory. Note, however, if you have a lot of child
8468# processes, these sleep delays will add up and your
8469# Squid will not service requests for some amount of time
8470# until all the child processes have been started.
8471# On Windows value less then 1000 (1 milliseconds) are
8472# rounded to 1000.
8473#Default:
8474# sleep_after_fork 0
8475
8476# TAG: windows_ipaddrchangemonitor on|off
8477# Note: This option is only available if Squid is rebuilt with the
8478# MS Windows
8479#
8480# On Windows Squid by default will monitor IP address changes and will
8481# reconfigure itself after any detected event. This is very useful for
8482# proxies connected to internet with dial-up interfaces.
8483# In some cases (a Proxy server acting as VPN gateway is one) it could be
8484# desiderable to disable this behaviour setting this to 'off'.
8485# Note: after changing this, Squid service must be restarted.
8486#Default:
8487# windows_ipaddrchangemonitor on
8488
8489# TAG: eui_lookup
8490# Whether to lookup the EUI or MAC address of a connected client.
8491#Default:
8492# eui_lookup on
8493
8494# TAG: max_filedescriptors
8495# Reduce the maximum number of filedescriptors supported below
8496# the usual operating system defaults.
8497#
8498# Remove from squid.conf to inherit the current ulimit setting.
8499#
8500# Note: Changing this requires a restart of Squid. Also
8501# not all I/O types supports large values (eg on Windows).
8502#Default:
8503# Use operating system limits set by ulimit.
8504
8505# TAG: force_request_body_continuation
8506# This option controls how Squid handles data upload requests from HTTP
8507# and FTP agents that require a "Please Continue" control message response
8508# to actually send the request body to Squid. It is mostly useful in
8509# adaptation environments.
8510#
8511# When Squid receives an HTTP request with an "Expect: 100-continue"
8512# header or an FTP upload command (e.g., STOR), Squid normally sends the
8513# request headers or FTP command information to an adaptation service (or
8514# peer) and waits for a response. Most adaptation services (and some
8515# broken peers) may not respond to Squid at that stage because they may
8516# decide to wait for the HTTP request body or FTP data transfer. However,
8517# that request body or data transfer may never come because Squid has not
8518# responded with the HTTP 100 or FTP 150 (Please Continue) control message
8519# to the request sender yet!
8520#
8521# An allow match tells Squid to respond with the HTTP 100 or FTP 150
8522# (Please Continue) control message on its own, before forwarding the
8523# request to an adaptation service or peer. Such a response usually forces
8524# the request sender to proceed with sending the body. A deny match tells
8525# Squid to delay that control response until the origin server confirms
8526# that the request body is needed. Delaying is the default behavior.
8527#Default:
8528# Deny, unless rules exist in squid.conf.
8529
8530# TAG: server_pconn_for_nonretriable
8531# This option provides fine-grained control over persistent connection
8532# reuse when forwarding HTTP requests that Squid cannot retry. It is useful
8533# in environments where opening new connections is very expensive
8534# (e.g., all connections are secured with TLS with complex client and server
8535# certificate validation) and race conditions associated with persistent
8536# connections are very rare and/or only cause minor problems.
8537#
8538# HTTP prohibits retrying unsafe and non-idempotent requests (e.g., POST).
8539# Squid limitations also prohibit retrying all requests with bodies (e.g., PUT).
8540# By default, when forwarding such "risky" requests, Squid opens a new
8541# connection to the server or cache_peer, even if there is an idle persistent
8542# connection available. When Squid is configured to risk sending a non-retriable
8543# request on a previously used persistent connection, and the server closes
8544# the connection before seeing that risky request, the user gets an error response
8545# from Squid. In most cases, that error response will be HTTP 502 (Bad Gateway)
8546# with ERR_ZERO_SIZE_OBJECT or ERR_WRITE_ERROR (peer connection reset) error detail.
8547#
8548# If an allow rule matches, Squid reuses an available idle persistent connection
8549# (if any) for the request that Squid cannot retry. If a deny rule matches, then
8550# Squid opens a new connection for the request that Squid cannot retry.
8551#
8552# This option does not affect requests that Squid can retry. They will reuse idle
8553# persistent connections (if any).
8554#
8555# This clause only supports fast acl types.
8556# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
8557#
8558# Example:
8559# acl SpeedIsWorthTheRisk method POST
8560# server_pconn_for_nonretriable allow SpeedIsWorthTheRisk
8561#Default:
8562# Open new connections for forwarding requests Squid cannot retry safely.