· 10 years ago · Jun 29, 2016, 02:36 PM
1# WELCOME TO SQUID 3.5.15-20160302-r14000
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
103# TAG: broken_vary_encoding
104# This option is not yet supported by Squid-3.
105#Default:
106# none
107
108# TAG: cache_vary
109# This option is not yet supported by Squid-3.
110#Default:
111# none
112
113# TAG: error_map
114# This option is not yet supported by Squid-3.
115#Default:
116# none
117
118# TAG: external_refresh_check
119# This option is not yet supported by Squid-3.
120#Default:
121# none
122
123# TAG: location_rewrite_program
124# This option is not yet supported by Squid-3.
125#Default:
126# none
127
128# TAG: refresh_stale_hit
129# This option is not yet supported by Squid-3.
130#Default:
131# none
132
133# TAG: hierarchy_stoplist
134# Remove this line. Use always_direct or cache_peer_access ACLs instead if you need to prevent cache_peer use.
135#Default:
136# none
137
138# TAG: log_access
139# Remove this line. Use acls with access_log directives to control access logging
140#Default:
141# none
142
143# TAG: log_icap
144# Remove this line. Use acls with icap_log directives to control icap logging
145#Default:
146# none
147
148# TAG: ignore_ims_on_miss
149# Remove this line. The HTTP/1.1 feature is now configured by 'cache_miss_revalidate'.
150#Default:
151# none
152
153# TAG: chunked_request_body_max_size
154# Remove this line. Squid is now HTTP/1.1 compliant.
155#Default:
156# none
157
158# TAG: dns_v4_fallback
159# Remove this line. Squid performs a 'Happy Eyeballs' algorithm, the 'fallback' algorithm is no longer relevant.
160#Default:
161# none
162
163# TAG: emulate_httpd_log
164# Replace this with an access_log directive using the format 'common' or 'combined'.
165#Default:
166# none
167
168# TAG: forward_log
169# Use a regular access.log with ACL limiting it to MISS events.
170#Default:
171# none
172
173# TAG: ftp_list_width
174# Remove this line. Configure FTP page display using the CSS controls in errorpages.css instead.
175#Default:
176# none
177
178# TAG: ignore_expect_100
179# Remove this line. The HTTP/1.1 feature is now fully supported by default.
180#Default:
181# none
182
183# TAG: log_fqdn
184# Remove this option from your config. To log FQDN use %>A in the log format.
185#Default:
186# none
187
188# TAG: log_ip_on_direct
189# Remove this option from your config. To log server or peer names use %<A in the log format.
190#Default:
191# none
192
193# TAG: maximum_single_addr_tries
194# Replaced by connect_retries. The behaviour has changed, please read the documentation before altering.
195#Default:
196# none
197
198# TAG: referer_log
199# Replace this with an access_log directive using the format 'referrer'.
200#Default:
201# none
202
203# TAG: update_headers
204# Remove this line. The feature is supported by default in storage types where update is implemented.
205#Default:
206# none
207
208# TAG: url_rewrite_concurrency
209# Remove this line. Set the 'concurrency=' option of url_rewrite_children instead.
210#Default:
211# none
212
213# TAG: useragent_log
214# Replace this with an access_log directive using the format 'useragent'.
215#Default:
216# none
217
218# TAG: dns_testnames
219# Remove this line. DNS is no longer tested on startup.
220#Default:
221# none
222
223# TAG: extension_methods
224# Remove this line. All valid methods for HTTP are accepted by default.
225#Default:
226# none
227
228# TAG: zero_buffers
229#Default:
230# none
231
232# TAG: incoming_rate
233#Default:
234# none
235
236# TAG: server_http11
237# Remove this line. HTTP/1.1 is supported by default.
238#Default:
239# none
240
241# TAG: upgrade_http0.9
242# Remove this line. ICY/1.0 streaming protocol is supported by default.
243#Default:
244# none
245
246# TAG: zph_local
247# Alter these entries. Use the qos_flows directive instead.
248#Default:
249# none
250
251# TAG: header_access
252# Since squid-3.0 replace with request_header_access or reply_header_access
253# depending on whether you wish to match client requests or server replies.
254#Default:
255# none
256
257# TAG: httpd_accel_no_pmtu_disc
258# Since squid-3.0 use the 'disable-pmtu-discovery' flag on http_port instead.
259#Default:
260# none
261
262# TAG: wais_relay_host
263# Replace this line with 'cache_peer' configuration.
264#Default:
265# none
266
267# TAG: wais_relay_port
268# Replace this line with 'cache_peer' configuration.
269#Default:
270# none
271
272# OPTIONS FOR SMP
273# -----------------------------------------------------------------------------
274
275# TAG: workers
276# Number of main Squid processes or "workers" to fork and maintain.
277# 0: "no daemon" mode, like running "squid -N ..."
278# 1: "no SMP" mode, start one main Squid process daemon (default)
279# N: start N main Squid process daemons (i.e., SMP mode)
280#
281# In SMP mode, each worker does nearly all what a single Squid daemon
282# does (e.g., listen on http_port and forward HTTP requests).
283#Default:
284# SMP support disabled.
285
286# TAG: cpu_affinity_map
287# Usage: cpu_affinity_map process_numbers=P1,P2,... cores=C1,C2,...
288#
289# Sets 1:1 mapping between Squid processes and CPU cores. For example,
290#
291# cpu_affinity_map process_numbers=1,2,3,4 cores=1,3,5,7
292#
293# affects processes 1 through 4 only and places them on the first
294# four even cores, starting with core #1.
295#
296# CPU cores are numbered starting from 1. Requires support for
297# sched_getaffinity(2) and sched_setaffinity(2) system calls.
298#
299# Multiple cpu_affinity_map options are merged.
300#
301# See also: workers
302#Default:
303# Let operating system decide.
304
305# OPTIONS FOR AUTHENTICATION
306# -----------------------------------------------------------------------------
307
308# TAG: auth_param
309# Note: This option is only available if Squid is rebuilt with the
310# --enable-auth
311#
312# This is used to define parameters for the various authentication
313# schemes supported by Squid.
314#
315# format: auth_param scheme parameter [setting]
316#
317# The order in which authentication schemes are presented to the client is
318# dependent on the order the scheme first appears in config file. IE
319# has a bug (it's not RFC 2617 compliant) in that it will use the basic
320# scheme if basic is the first entry presented, even if more secure
321# schemes are presented. For now use the order in the recommended
322# settings section below. If other browsers have difficulties (don't
323# recognize the schemes offered even if you are using basic) either
324# put basic first, or disable the other schemes (by commenting out their
325# program entry).
326#
327# Once an authentication scheme is fully configured, it can only be
328# shutdown by shutting squid down and restarting. Changes can be made on
329# the fly and activated with a reconfigure. I.E. You can change to a
330# different helper, but not unconfigure the helper completely.
331#
332# Please note that while this directive defines how Squid processes
333# authentication it does not automatically activate authentication.
334# To use authentication you must in addition make use of ACLs based
335# on login name in http_access (proxy_auth, proxy_auth_regex or
336# external with %LOGIN used in the format tag). The browser will be
337# challenged for authentication on the first such acl encountered
338# in http_access processing and will also be re-challenged for new
339# login credentials if the request is being denied by a proxy_auth
340# type acl.
341#
342# WARNING: authentication can't be used in a transparently intercepting
343# proxy as the client then thinks it is talking to an origin server and
344# not the proxy. This is a limitation of bending the TCP/IP protocol to
345# transparently intercepting port 80, not a limitation in Squid.
346# Ports flagged 'transparent', 'intercept', or 'tproxy' have
347# authentication disabled.
348#
349# === Parameters common to all schemes. ===
350#
351# "program" cmdline
352# Specifies the command for the external authenticator.
353#
354# By default, each authentication scheme is not used unless a
355# program is specified.
356#
357# See http://wiki.squid-cache.org/Features/AddonHelpers for
358# more details on helper operations and creating your own.
359#
360# "key_extras" format
361# Specifies a string to be append to request line format for
362# the authentication helper. "Quoted" format values may contain
363# spaces and logformat %macros. In theory, any logformat %macro
364# can be used. In practice, a %macro expands as a dash (-) if
365# the helper request is sent before the required macro
366# information is available to Squid.
367#
368# By default, Squid uses request formats provided in
369# scheme-specific examples below (search for %credentials).
370#
371# The expanded key_extras value is added to the Squid credentials
372# cache and, hence, will affect authentication. It can be used to
373# autenticate different users with identical user names (e.g.,
374# when user authentication depends on http_port).
375#
376# Avoid adding frequently changing information to key_extras. For
377# example, if you add user source IP, and it changes frequently
378# in your environment, then max_user_ip ACL is going to treat
379# every user+IP combination as a unique "user", breaking the ACL
380# and wasting a lot of memory on those user records. It will also
381# force users to authenticate from scratch whenever their IP
382# changes.
383#
384# "realm" string
385# Specifies the protection scope (aka realm name) which is to be
386# reported to the client for the authentication scheme. It is
387# commonly part of the text the user will see when prompted for
388# their username and password.
389#
390# For Basic the default is "Squid proxy-caching web server".
391# For Digest there is no default, this parameter is mandatory.
392# For NTLM and Negotiate this parameter is ignored.
393#
394# "children" numberofchildren [startup=N] [idle=N] [concurrency=N]
395#
396# The maximum number of authenticator processes to spawn. If
397# you start too few Squid will have to wait for them to process
398# a backlog of credential verifications, slowing it down. When
399# password verifications are done via a (slow) network you are
400# likely to need lots of authenticator processes.
401#
402# The startup= and idle= options permit some skew in the exact
403# amount run. A minimum of startup=N will begin during startup
404# and reconfigure. Squid will start more in groups of up to
405# idle=N in an attempt to meet traffic needs and to keep idle=N
406# free above those traffic needs up to the maximum.
407#
408# The concurrency= option sets the number of concurrent requests
409# the helper can process. The default of 0 is used for helpers
410# who only supports one request at a time. Setting this to a
411# number greater than 0 changes the protocol used to include a
412# channel ID field first on the request/response line, allowing
413# multiple requests to be sent to the same helper in parallel
414# without waiting for the response.
415#
416# Concurrency must not be set unless it's known the helper
417# supports the input format with channel-ID fields.
418#
419# NOTE: NTLM and Negotiate schemes do not support concurrency
420# in the Squid code module even though some helpers can.
421#
422#
423#
424# === Example Configuration ===
425#
426# This configuration displays the recommended authentication scheme
427# order from most to least secure with recommended minimum configuration
428# settings for each scheme:
429#
430##auth_param negotiate program <uncomment and complete this line to activate>
431##auth_param negotiate children 20 startup=0 idle=1
432##auth_param negotiate keep_alive on
433##
434##auth_param digest program <uncomment and complete this line to activate>
435##auth_param digest children 20 startup=0 idle=1
436##auth_param digest realm Squid proxy-caching web server
437##auth_param digest nonce_garbage_interval 5 minutes
438##auth_param digest nonce_max_duration 30 minutes
439##auth_param digest nonce_max_count 50
440##
441##auth_param ntlm program <uncomment and complete this line to activate>
442##auth_param ntlm children 20 startup=0 idle=1
443##auth_param ntlm keep_alive on
444##
445##auth_param basic program <uncomment and complete this line>
446##auth_param basic children 5 startup=5 idle=1
447##auth_param basic realm Squid proxy-caching web server
448##auth_param basic credentialsttl 2 hours
449#Default:
450# none
451
452# TAG: authenticate_cache_garbage_interval
453# The time period between garbage collection across the username cache.
454# This is a trade-off between memory utilization (long intervals - say
455# 2 days) and CPU (short intervals - say 1 minute). Only change if you
456# have good reason to.
457#Default:
458# authenticate_cache_garbage_interval 1 hour
459
460# TAG: authenticate_ttl
461# The time a user & their credentials stay in the logged in
462# user cache since their last request. When the garbage
463# interval passes, all user credentials that have passed their
464# TTL are removed from memory.
465#Default:
466# authenticate_ttl 1 hour
467
468# TAG: authenticate_ip_ttl
469# If you use proxy authentication and the 'max_user_ip' ACL,
470# this directive controls how long Squid remembers the IP
471# addresses associated with each user. Use a small value
472# (e.g., 60 seconds) if your users might change addresses
473# quickly, as is the case with dialup. You might be safe
474# using a larger value (e.g., 2 hours) in a corporate LAN
475# environment with relatively static address assignments.
476#Default:
477# authenticate_ip_ttl 1 second
478
479# ACCESS CONTROLS
480# -----------------------------------------------------------------------------
481
482# TAG: external_acl_type
483# This option defines external acl classes using a helper program
484# to look up the status
485#
486# external_acl_type name [options] FORMAT.. /path/to/helper [helper arguments..]
487#
488# Options:
489#
490# ttl=n TTL in seconds for cached results (defaults to 3600
491# for 1 hour)
492#
493# negative_ttl=n
494# TTL for cached negative lookups (default same
495# as ttl)
496#
497# grace=n Percentage remaining of TTL where a refresh of a
498# cached entry should be initiated without needing to
499# wait for a new reply. (default is for no grace period)
500#
501# cache=n The maximum number of entries in the result cache. The
502# default limit is 262144 entries. Each cache entry usually
503# consumes at least 256 bytes. Squid currently does not remove
504# expired cache entries until the limit is reached, so a proxy
505# will sooner or later reach the limit. The expanded FORMAT
506# value is used as the cache key, so if the details in FORMAT
507# are highly variable, a larger cache may be needed to produce
508# reduction in helper load.
509#
510# children-max=n
511# Maximum number of acl helper processes spawned to service
512# external acl lookups of this type. (default 20)
513#
514# children-startup=n
515# Minimum number of acl helper processes to spawn during
516# startup and reconfigure to service external acl lookups
517# of this type. (default 0)
518#
519# children-idle=n
520# Number of acl helper processes to keep ahead of traffic
521# loads. Squid will spawn this many at once whenever load
522# rises above the capabilities of existing processes.
523# Up to the value of children-max. (default 1)
524#
525# concurrency=n concurrency level per process. Only used with helpers
526# capable of processing more than one query at a time.
527#
528# protocol=2.5 Compatibility mode for Squid-2.5 external acl helpers.
529#
530# ipv4 / ipv6 IP protocol used to communicate with this helper.
531# The default is to auto-detect IPv6 and use it when available.
532#
533#
534# FORMAT specifications
535#
536# %LOGIN Authenticated user login name
537# %un A user name. Expands to the first available name
538# from the following list of information sources:
539# - authenticated user name, like %ul or %LOGIN
540# - user name sent by an external ACL, like %EXT_USER
541# - SSL client name, like %us in logformat
542# - ident user name, like %ui in logformat
543# %EXT_USER Username from previous external acl
544# %EXT_LOG Log details from previous external acl
545# %EXT_TAG Tag from previous external acl
546# %IDENT Ident user name
547# %SRC Client IP
548# %SRCPORT Client source port
549# %URI Requested URI
550# %DST Requested host
551# %PROTO Requested URL scheme
552# %PORT Requested port
553# %PATH Requested URL path
554# %METHOD Request method
555# %MYADDR Squid interface address
556# %MYPORT Squid http_port number
557# %PATH Requested URL-path (including query-string if any)
558# %USER_CERT SSL User certificate in PEM format
559# %USER_CERTCHAIN SSL User certificate chain in PEM format
560# %USER_CERT_xx SSL User certificate subject attribute xx
561# %USER_CA_CERT_xx SSL User certificate issuer attribute xx
562# %ssl::>sni SSL client SNI sent to Squid
563# %ssl::<cert_subject SSL server certificate DN
564# %ssl::<cert_issuer SSL server certificate issuer DN
565#
566# %>{Header} HTTP request header "Header"
567# %>{Hdr:member}
568# HTTP request header "Hdr" list member "member"
569# %>{Hdr:;member}
570# HTTP request header list member using ; as
571# list separator. ; can be any non-alphanumeric
572# character.
573#
574# %<{Header} HTTP reply header "Header"
575# %<{Hdr:member}
576# HTTP reply header "Hdr" list member "member"
577# %<{Hdr:;member}
578# HTTP reply header list member using ; as
579# list separator. ; can be any non-alphanumeric
580# character.
581#
582# %ACL The name of the ACL being tested.
583# %DATA The ACL arguments. If not used then any arguments
584# is automatically added at the end of the line
585# sent to the helper.
586# NOTE: this will encode the arguments as one token,
587# whereas the default will pass each separately.
588#
589# %% The percent sign. Useful for helpers which need
590# an unchanging input format.
591#
592#
593# General request syntax:
594#
595# [channel-ID] FORMAT-values [acl-values ...]
596#
597#
598# FORMAT-values consists of transaction details expanded with
599# whitespace separation per the config file FORMAT specification
600# using the FORMAT macros listed above.
601#
602# acl-values consists of any string specified in the referencing
603# config 'acl ... external' line. see the "acl external" directive.
604#
605# Request values sent to the helper are URL escaped to protect
606# each value in requests against whitespaces.
607#
608# If using protocol=2.5 then the request sent to the helper is not
609# URL escaped to protect against whitespace.
610#
611# NOTE: protocol=3.0 is deprecated as no longer necessary.
612#
613# When using the concurrency= option the protocol is changed by
614# introducing a query channel tag in front of the request/response.
615# The query channel tag is a number between 0 and concurrency-1.
616# This value must be echoed back unchanged to Squid as the first part
617# of the response relating to its request.
618#
619#
620# The helper receives lines expanded per the above format specification
621# and for each input line returns 1 line starting with OK/ERR/BH result
622# code and optionally followed by additional keywords with more details.
623#
624#
625# General result syntax:
626#
627# [channel-ID] result keyword=value ...
628#
629# Result consists of one of the codes:
630#
631# OK
632# the ACL test produced a match.
633#
634# ERR
635# the ACL test does not produce a match.
636#
637# BH
638# An internal error occurred in the helper, preventing
639# a result being identified.
640#
641# The meaning of 'a match' is determined by your squid.conf
642# access control configuration. See the Squid wiki for details.
643#
644# Defined keywords:
645#
646# user= The users name (login)
647#
648# password= The users password (for login= cache_peer option)
649#
650# message= Message describing the reason for this response.
651# Available as %o in error pages.
652# Useful on (ERR and BH results).
653#
654# tag= Apply a tag to a request. Only sets a tag once,
655# does not alter existing tags.
656#
657# log= String to be logged in access.log. Available as
658# %ea in logformat specifications.
659#
660# clt_conn_tag= Associates a TAG with the client TCP connection.
661# Please see url_rewrite_program related documentation
662# for this kv-pair.
663#
664# Any keywords may be sent on any response whether OK, ERR or BH.
665#
666# All response keyword values need to be a single token with URL
667# escaping, or enclosed in double quotes (") and escaped using \ on
668# any double quotes or \ characters within the value. The wrapping
669# double quotes are removed before the value is interpreted by Squid.
670# \r and \n are also replace by CR and LF.
671#
672# Some example key values:
673#
674# user=John%20Smith
675# user="John Smith"
676# user="J. \"Bob\" Smith"
677#Default:
678# none
679
680# TAG: acl
681# Defining an Access List
682#
683# Every access list definition must begin with an aclname and acltype,
684# followed by either type-specific arguments or a quoted filename that
685# they are read from.
686#
687# acl aclname acltype argument ...
688# acl aclname acltype "file" ...
689#
690# When using "file", the file should contain one item per line.
691#
692# Some acl types supports options which changes their default behaviour.
693# The available options are:
694#
695# -i,+i By default, regular expressions are CASE-SENSITIVE. To make them
696# case-insensitive, use the -i option. To return case-sensitive
697# use the +i option between patterns, or make a new ACL line
698# without -i.
699#
700# -n Disable lookups and address type conversions. If lookup or
701# conversion is required because the parameter type (IP or
702# domain name) does not match the message address type (domain
703# name or IP), then the ACL would immediately declare a mismatch
704# without any warnings or lookups.
705#
706# -- Used to stop processing all options, in the case the first acl
707# value has '-' character as first character (for example the '-'
708# is a valid domain name)
709#
710# Some acl types require suspending the current request in order
711# to access some external data source.
712# Those which do are marked with the tag [slow], those which
713# don't are marked as [fast].
714# See http://wiki.squid-cache.org/SquidFaq/SquidAcl
715# for further information
716#
717# ***** ACL TYPES AVAILABLE *****
718#
719# acl aclname src ip-address/mask ... # clients IP address [fast]
720# acl aclname src addr1-addr2/mask ... # range of addresses [fast]
721# acl aclname dst [-n] ip-address/mask ... # URL host's IP address [slow]
722# acl aclname localip ip-address/mask ... # IP address the client connected to [fast]
723#
724# acl aclname arp mac-address ... (xx:xx:xx:xx:xx:xx notation)
725# # [fast]
726# # The 'arp' ACL code is not portable to all operating systems.
727# # It works on Linux, Solaris, Windows, FreeBSD, and some other
728# # BSD variants.
729# #
730# # NOTE: Squid can only determine the MAC/EUI address for IPv4
731# # clients that are on the same subnet. If the client is on a
732# # different subnet, then Squid cannot find out its address.
733# #
734# # NOTE 2: IPv6 protocol does not contain ARP. MAC/EUI is either
735# # encoded directly in the IPv6 address or not available.
736#
737# acl aclname srcdomain .foo.com ...
738# # reverse lookup, from client IP [slow]
739# acl aclname dstdomain [-n] .foo.com ...
740# # Destination server from URL [fast]
741# acl aclname srcdom_regex [-i] \.foo\.com ...
742# # regex matching client name [slow]
743# acl aclname dstdom_regex [-n] [-i] \.foo\.com ...
744# # regex matching server [fast]
745# #
746# # For dstdomain and dstdom_regex a reverse lookup is tried if a IP
747# # based URL is used and no match is found. The name "none" is used
748# # if the reverse lookup fails.
749#
750# acl aclname src_as number ...
751# acl aclname dst_as number ...
752# # [fast]
753# # Except for access control, AS numbers can be used for
754# # routing of requests to specific caches. Here's an
755# # example for routing all requests for AS#1241 and only
756# # those to mycache.mydomain.net:
757# # acl asexample dst_as 1241
758# # cache_peer_access mycache.mydomain.net allow asexample
759# # cache_peer_access mycache_mydomain.net deny all
760#
761# acl aclname peername myPeer ...
762# # [fast]
763# # match against a named cache_peer entry
764# # set unique name= on cache_peer lines for reliable use.
765#
766# acl aclname time [day-abbrevs] [h1:m1-h2:m2]
767# # [fast]
768# # day-abbrevs:
769# # S - Sunday
770# # M - Monday
771# # T - Tuesday
772# # W - Wednesday
773# # H - Thursday
774# # F - Friday
775# # A - Saturday
776# # h1:m1 must be less than h2:m2
777#
778# acl aclname url_regex [-i] ^http:// ...
779# # regex matching on whole URL [fast]
780# acl aclname urllogin [-i] [^a-zA-Z0-9] ...
781# # regex matching on URL login field
782# acl aclname urlpath_regex [-i] \.gif$ ...
783# # regex matching on URL path [fast]
784#
785# acl aclname port 80 70 21 0-1024... # destination TCP port [fast]
786# # ranges are alloed
787# acl aclname localport 3128 ... # TCP port the client connected to [fast]
788# # NP: for interception mode this is usually '80'
789#
790# acl aclname myportname 3128 ... # *_port name [fast]
791#
792# acl aclname proto HTTP FTP ... # request protocol [fast]
793#
794# acl aclname method GET POST ... # HTTP request method [fast]
795#
796# acl aclname http_status 200 301 500- 400-403 ...
797# # status code in reply [fast]
798#
799# acl aclname browser [-i] regexp ...
800# # pattern match on User-Agent header (see also req_header below) [fast]
801#
802# acl aclname referer_regex [-i] regexp ...
803# # pattern match on Referer header [fast]
804# # Referer is highly unreliable, so use with care
805#
806# acl aclname ident username ...
807# acl aclname ident_regex [-i] pattern ...
808# # string match on ident output [slow]
809# # use REQUIRED to accept any non-null ident.
810#
811# acl aclname proxy_auth [-i] username ...
812# acl aclname proxy_auth_regex [-i] pattern ...
813# # perform http authentication challenge to the client and match against
814# # supplied credentials [slow]
815# #
816# # takes a list of allowed usernames.
817# # use REQUIRED to accept any valid username.
818# #
819# # Will use proxy authentication in forward-proxy scenarios, and plain
820# # http authenticaiton in reverse-proxy scenarios
821# #
822# # NOTE: when a Proxy-Authentication header is sent but it is not
823# # needed during ACL checking the username is NOT logged
824# # in access.log.
825# #
826# # NOTE: proxy_auth requires a EXTERNAL authentication program
827# # to check username/password combinations (see
828# # auth_param directive).
829# #
830# # NOTE: proxy_auth can't be used in a transparent/intercepting proxy
831# # as the browser needs to be configured for using a proxy in order
832# # to respond to proxy authentication.
833#
834# acl aclname snmp_community string ...
835# # A community string to limit access to your SNMP Agent [fast]
836# # Example:
837# #
838# # acl snmppublic snmp_community public
839#
840# acl aclname maxconn number
841# # This will be matched when the client's IP address has
842# # more than <number> TCP connections established. [fast]
843# # NOTE: This only measures direct TCP links so X-Forwarded-For
844# # indirect clients are not counted.
845#
846# acl aclname max_user_ip [-s] number
847# # This will be matched when the user attempts to log in from more
848# # than <number> different ip addresses. The authenticate_ip_ttl
849# # parameter controls the timeout on the ip entries. [fast]
850# # If -s is specified the limit is strict, denying browsing
851# # from any further IP addresses until the ttl has expired. Without
852# # -s Squid will just annoy the user by "randomly" denying requests.
853# # (the counter is reset each time the limit is reached and a
854# # request is denied)
855# # NOTE: in acceleration mode or where there is mesh of child proxies,
856# # clients may appear to come from multiple addresses if they are
857# # going through proxy farms, so a limit of 1 may cause user problems.
858#
859# acl aclname random probability
860# # Pseudo-randomly match requests. Based on the probability given.
861# # Probability may be written as a decimal (0.333), fraction (1/3)
862# # or ratio of matches:non-matches (3:5).
863#
864# acl aclname req_mime_type [-i] mime-type ...
865# # regex match against the mime type of the request generated
866# # by the client. Can be used to detect file upload or some
867# # types HTTP tunneling requests [fast]
868# # NOTE: This does NOT match the reply. You cannot use this
869# # to match the returned file type.
870#
871# acl aclname req_header header-name [-i] any\.regex\.here
872# # regex match against any of the known request headers. May be
873# # thought of as a superset of "browser", "referer" and "mime-type"
874# # ACL [fast]
875#
876# acl aclname rep_mime_type [-i] mime-type ...
877# # regex match against the mime type of the reply received by
878# # squid. Can be used to detect file download or some
879# # types HTTP tunneling requests. [fast]
880# # NOTE: This has no effect in http_access rules. It only has
881# # effect in rules that affect the reply data stream such as
882# # http_reply_access.
883#
884# acl aclname rep_header header-name [-i] any\.regex\.here
885# # regex match against any of the known reply headers. May be
886# # thought of as a superset of "browser", "referer" and "mime-type"
887# # ACLs [fast]
888#
889# acl aclname external class_name [arguments...]
890# # external ACL lookup via a helper class defined by the
891# # external_acl_type directive [slow]
892#
893# acl aclname user_cert attribute values...
894# # match against attributes in a user SSL certificate
895# # attribute is one of DN/C/O/CN/L/ST or a numerical OID [fast]
896#
897# acl aclname ca_cert attribute values...
898# # match against attributes a users issuing CA SSL certificate
899# # attribute is one of DN/C/O/CN/L/ST or a numerical OID [fast]
900#
901# acl aclname ext_user username ...
902# acl aclname ext_user_regex [-i] pattern ...
903# # string match on username returned by external acl helper [slow]
904# # use REQUIRED to accept any non-null user name.
905#
906# acl aclname tag tagvalue ...
907# # string match on tag returned by external acl helper [fast]
908# # DEPRECATED. Only the first tag will match with this ACL.
909# # Use the 'note' ACL instead for handling multiple tag values.
910#
911# acl aclname hier_code codename ...
912# # string match against squid hierarchy code(s); [fast]
913# # e.g., DIRECT, PARENT_HIT, NONE, etc.
914# #
915# # NOTE: This has no effect in http_access rules. It only has
916# # effect in rules that affect the reply data stream such as
917# # http_reply_access.
918#
919# acl aclname note name [value ...]
920# # match transaction annotation [fast]
921# # Without values, matches any annotation with a given name.
922# # With value(s), matches any annotation with a given name that
923# # also has one of the given values.
924# # Names and values are compared using a string equality test.
925# # Annotation sources include note and adaptation_meta directives
926# # as well as helper and eCAP responses.
927#
928# acl aclname adaptation_service service ...
929# # Matches the name of any icap_service, ecap_service,
930# # adaptation_service_set, or adaptation_service_chain that Squid
931# # has used (or attempted to use) for the master transaction.
932# # This ACL must be defined after the corresponding adaptation
933# # service is named in squid.conf. This ACL is usable with
934# # adaptation_meta because it starts matching immediately after
935# # the service has been selected for adaptation.
936#
937# acl aclname ssl_error errorname
938# # match against SSL certificate validation error [fast]
939# #
940# # For valid error names see in /usr/share/squid/errors/templates/error-details.txt
941# # template file.
942# #
943# # The following can be used as shortcuts for certificate properties:
944# # [ssl::]certHasExpired: the "not after" field is in the past
945# # [ssl::]certNotYetValid: the "not before" field is in the future
946# # [ssl::]certUntrusted: The certificate issuer is not to be trusted.
947# # [ssl::]certSelfSigned: The certificate is self signed.
948# # [ssl::]certDomainMismatch: The certificate CN domain does not
949# # match the name the name of the host we are connecting to.
950# #
951# # The ssl::certHasExpired, ssl::certNotYetValid, ssl::certDomainMismatch,
952# # ssl::certUntrusted, and ssl::certSelfSigned can also be used as
953# # predefined ACLs, just like the 'all' ACL.
954# #
955# # NOTE: The ssl_error ACL is only supported with sslproxy_cert_error,
956# # sslproxy_cert_sign, and sslproxy_cert_adapt options.
957#
958# acl aclname server_cert_fingerprint [-sha1] fingerprint
959# # match against server SSL certificate fingerprint [fast]
960# #
961# # The fingerprint is the digest of the DER encoded version
962# # of the whole certificate. The user should use the form: XX:XX:...
963# # Optional argument specifies the digest algorithm to use.
964# # The SHA1 digest algorithm is the default and is currently
965# # the only algorithm supported (-sha1).
966#
967# acl aclname at_step step
968# # match against the current step during ssl_bump evaluation [fast]
969# # Never matches and should not be used outside the ssl_bump context.
970# #
971# # At each SslBump step, Squid evaluates ssl_bump directives to find
972# # the next bumping action (e.g., peek or splice). Valid SslBump step
973# # values and the corresponding ssl_bump evaluation moments are:
974# # SslBump1: After getting TCP-level and HTTP CONNECT info.
975# # SslBump2: After getting SSL Client Hello info.
976# # SslBump3: After getting SSL Server Hello info.
977#
978# acl aclname ssl::server_name .foo.com ...
979# # matches server name obtained from various sources [fast]
980# #
981# # The server name is obtained during Ssl-Bump steps from such sources
982# # as CONNECT request URI, client SNI, and SSL server certificate CN.
983# # During each Ssl-Bump step, Squid may improve its understanding of a
984# # "true server name". Unlike dstdomain, this ACL does not perform
985# # DNS lookups.
986#
987# acl aclname ssl::server_name_regex [-i] \.foo\.com ...
988# # regex matches server name obtained from various sources [fast]
989# acl aclname any-of acl1 acl2 ...
990# # match any one of the acls [fast or slow]
991# # The first matching ACL stops further ACL evaluation.
992# #
993# # ACLs from multiple any-of lines with the same name are ORed.
994# # For example, A = (a1 or a2) or (a3 or a4) can be written as
995# # acl A any-of a1 a2
996# # acl A any-of a3 a4
997# #
998# # This group ACL is fast if all evaluated ACLs in the group are fast
999# # and slow otherwise.
1000#
1001# acl aclname all-of acl1 acl2 ...
1002# # match all of the acls [fast or slow]
1003# # The first mismatching ACL stops further ACL evaluation.
1004# #
1005# # ACLs from multiple all-of lines with the same name are ORed.
1006# # For example, B = (b1 and b2) or (b3 and b4) can be written as
1007# # acl B all-of b1 b2
1008# # acl B all-of b3 b4
1009# #
1010# # This group ACL is fast if all evaluated ACLs in the group are fast
1011# # and slow otherwise.
1012#
1013# Examples:
1014# acl macaddress arp 09:00:2b:23:45:67
1015# acl myexample dst_as 1241
1016# acl password proxy_auth REQUIRED
1017# acl fileupload req_mime_type -i ^multipart/form-data$
1018# acl javascript rep_mime_type -i ^application/x-javascript$
1019#
1020#Default:
1021# ACLs all, manager, localhost, and to_localhost are predefined.
1022#
1023#
1024# Recommended minimum configuration:
1025#
1026
1027# Example rule allowing access from your local networks.
1028# Adapt to list your (internal) IP networks from where browsing
1029# should be allowed
1030acl localnet src 10.0.0.0/8 # RFC1918 possible internal network
1031acl localnet src 172.16.0.0/12 # RFC1918 possible internal network
1032acl localnet src 192.168.0.0/16 # RFC1918 possible internal network
1033acl localnet src fc00::/7 # RFC 4193 local private network range
1034acl localnet src fe80::/10 # RFC 4291 link-local (directly plugged) machines
1035
1036acl SSL_ports port 443
1037acl Safe_ports port 80 # http
1038acl Safe_ports port 21 # ftp
1039acl Safe_ports port 443 # https
1040acl Safe_ports port 70 # gopher
1041acl Safe_ports port 210 # wais
1042acl Safe_ports port 1025-65535 # unregistered ports
1043acl Safe_ports port 280 # http-mgmt
1044acl Safe_ports port 488 # gss-http
1045acl Safe_ports port 591 # filemaker
1046acl Safe_ports port 777 # multiling http
1047acl CONNECT method CONNECT
1048
1049# TAG: proxy_protocol_access
1050# Determine which client proxies can be trusted to provide correct
1051# information regarding real client IP address using PROXY protocol.
1052#
1053# Requests may pass through a chain of several other proxies
1054# before reaching us. The original source details may by sent in:
1055# * HTTP message Forwarded header, or
1056# * HTTP message X-Forwarded-For header, or
1057# * PROXY protocol connection header.
1058#
1059# This directive is solely for validating new PROXY protocol
1060# connections received from a port flagged with require-proxy-header.
1061# It is checked only once after TCP connection setup.
1062#
1063# A deny match results in TCP connection closure.
1064#
1065# An allow match is required for Squid to permit the corresponding
1066# TCP connection, before Squid even looks for HTTP request headers.
1067# If there is an allow match, Squid starts using PROXY header information
1068# to determine the source address of the connection for all future ACL
1069# checks, logging, etc.
1070#
1071# SECURITY CONSIDERATIONS:
1072#
1073# Any host from which we accept client IP details can place
1074# incorrect information in the relevant header, and Squid
1075# will use the incorrect information as if it were the
1076# source address of the request. This may enable remote
1077# hosts to bypass any access control restrictions that are
1078# based on the client's source addresses.
1079#
1080# This clause only supports fast acl types.
1081# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1082#Default:
1083# all TCP connections to ports with require-proxy-header will be denied
1084
1085# TAG: follow_x_forwarded_for
1086# Determine which client proxies can be trusted to provide correct
1087# information regarding real client IP address.
1088#
1089# Requests may pass through a chain of several other proxies
1090# before reaching us. The original source details may by sent in:
1091# * HTTP message Forwarded header, or
1092# * HTTP message X-Forwarded-For header, or
1093# * PROXY protocol connection header.
1094#
1095# PROXY protocol connections are controlled by the proxy_protocol_access
1096# directive which is checked before this.
1097#
1098# If a request reaches us from a source that is allowed by this
1099# directive, then we trust the information it provides regarding
1100# the IP of the client it received from (if any).
1101#
1102# For the purpose of ACLs used in this directive the src ACL type always
1103# matches the address we are testing and srcdomain matches its rDNS.
1104#
1105# On each HTTP request Squid checks for X-Forwarded-For header fields.
1106# If found the header values are iterated in reverse order and an allow
1107# match is required for Squid to continue on to the next value.
1108# The verification ends when a value receives a deny match, cannot be
1109# tested, or there are no more values to test.
1110# NOTE: Squid does not yet follow the Forwarded HTTP header.
1111#
1112# The end result of this process is an IP address that we will
1113# refer to as the indirect client address. This address may
1114# be treated as the client address for access control, ICAP, delay
1115# pools and logging, depending on the acl_uses_indirect_client,
1116# icap_uses_indirect_client, delay_pool_uses_indirect_client,
1117# log_uses_indirect_client and tproxy_uses_indirect_client options.
1118#
1119# This clause only supports fast acl types.
1120# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1121#
1122# SECURITY CONSIDERATIONS:
1123#
1124# Any host from which we accept client IP details can place
1125# incorrect information in the relevant header, and Squid
1126# will use the incorrect information as if it were the
1127# source address of the request. This may enable remote
1128# hosts to bypass any access control restrictions that are
1129# based on the client's source addresses.
1130#
1131# For example:
1132#
1133# acl localhost src 127.0.0.1
1134# acl my_other_proxy srcdomain .proxy.example.com
1135# follow_x_forwarded_for allow localhost
1136# follow_x_forwarded_for allow my_other_proxy
1137#Default:
1138# X-Forwarded-For header will be ignored.
1139
1140# TAG: acl_uses_indirect_client on|off
1141# Controls whether the indirect client address
1142# (see follow_x_forwarded_for) is used instead of the
1143# direct client address in acl matching.
1144#
1145# NOTE: maxconn ACL considers direct TCP links and indirect
1146# clients will always have zero. So no match.
1147#Default:
1148# acl_uses_indirect_client on
1149
1150# TAG: delay_pool_uses_indirect_client on|off
1151# Note: This option is only available if Squid is rebuilt with the
1152# --enable-follow-x-forwarded-for and --enable-delay-pools
1153#
1154# Controls whether the indirect client address
1155# (see follow_x_forwarded_for) is used instead of the
1156# direct client address in delay pools.
1157#Default:
1158# delay_pool_uses_indirect_client on
1159
1160# TAG: log_uses_indirect_client on|off
1161# Controls whether the indirect client address
1162# (see follow_x_forwarded_for) is used instead of the
1163# direct client address in the access log.
1164#Default:
1165# log_uses_indirect_client on
1166
1167# TAG: tproxy_uses_indirect_client on|off
1168# Controls whether the indirect client address
1169# (see follow_x_forwarded_for) is used instead of the
1170# direct client address when spoofing the outgoing client.
1171#
1172# This has no effect on requests arriving in non-tproxy
1173# mode ports.
1174#
1175# SECURITY WARNING: Usage of this option is dangerous
1176# and should not be used trivially. Correct configuration
1177# of follow_x_forwarded_for with a limited set of trusted
1178# sources is required to prevent abuse of your proxy.
1179#Default:
1180# tproxy_uses_indirect_client off
1181
1182# TAG: spoof_client_ip
1183# Control client IP address spoofing of TPROXY traffic based on
1184# defined access lists.
1185#
1186# spoof_client_ip allow|deny [!]aclname ...
1187#
1188# If there are no "spoof_client_ip" lines present, the default
1189# is to "allow" spoofing of any suitable request.
1190#
1191# Note that the cache_peer "no-tproxy" option overrides this ACL.
1192#
1193# This clause supports fast acl types.
1194# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1195#Default:
1196# Allow spoofing on all TPROXY traffic.
1197
1198# TAG: http_access
1199# Allowing or Denying access based on defined access lists
1200#
1201# To allow or deny a message received on an HTTP, HTTPS, or FTP port:
1202# http_access allow|deny [!]aclname ...
1203#
1204# NOTE on default values:
1205#
1206# If there are no "access" lines present, the default is to deny
1207# the request.
1208#
1209# If none of the "access" lines cause a match, the default is the
1210# opposite of the last line in the list. If the last line was
1211# deny, the default is allow. Conversely, if the last line
1212# is allow, the default will be deny. For these reasons, it is a
1213# good idea to have an "deny all" entry at the end of your access
1214# lists to avoid potential confusion.
1215#
1216# This clause supports both fast and slow acl types.
1217# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1218#
1219#Default:
1220# Deny, unless rules exist in squid.conf.
1221#
1222
1223#
1224# Recommended minimum Access Permission configuration:
1225#
1226# Deny requests to certain unsafe ports
1227http_access deny !Safe_ports
1228
1229# Deny CONNECT to other than secure SSL ports
1230http_access deny CONNECT !SSL_ports
1231
1232# Only allow cachemgr access from localhost
1233http_access allow localhost manager
1234http_access deny manager
1235
1236# We strongly recommend the following be uncommented to protect innocent
1237# web applications running on the proxy server who think the only
1238# one who can access services on "localhost" is a local user
1239#http_access deny to_localhost
1240
1241#
1242# INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS
1243#
1244
1245# Example rule allowing access from your local networks.
1246# Adapt localnet in the ACL section to list your (internal) IP networks
1247# from where browsing should be allowed
1248http_access allow localnet
1249http_access allow localhost
1250
1251# And finally deny all other access to this proxy
1252http_access deny all
1253
1254# TAG: adapted_http_access
1255# Allowing or Denying access based on defined access lists
1256#
1257# Essentially identical to http_access, but runs after redirectors
1258# and ICAP/eCAP adaptation. Allowing access control based on their
1259# output.
1260#
1261# If not set then only http_access is used.
1262#Default:
1263# Allow, unless rules exist in squid.conf.
1264
1265# TAG: http_reply_access
1266# Allow replies to client requests. This is complementary to http_access.
1267#
1268# http_reply_access allow|deny [!] aclname ...
1269#
1270# NOTE: if there are no access lines present, the default is to allow
1271# all replies.
1272#
1273# If none of the access lines cause a match the opposite of the
1274# last line will apply. Thus it is good practice to end the rules
1275# with an "allow all" or "deny all" entry.
1276#
1277# This clause supports both fast and slow acl types.
1278# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1279#Default:
1280# Allow, unless rules exist in squid.conf.
1281
1282# TAG: icp_access
1283# Allowing or Denying access to the ICP port based on defined
1284# access lists
1285#
1286# icp_access allow|deny [!]aclname ...
1287#
1288# NOTE: The default if no icp_access lines are present is to
1289# deny all traffic. This default may cause problems with peers
1290# using ICP.
1291#
1292# This clause only supports fast acl types.
1293# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1294#
1295## Allow ICP queries from local networks only
1296##icp_access allow localnet
1297##icp_access deny all
1298#Default:
1299# Deny, unless rules exist in squid.conf.
1300
1301# TAG: htcp_access
1302# Allowing or Denying access to the HTCP port based on defined
1303# access lists
1304#
1305# htcp_access allow|deny [!]aclname ...
1306#
1307# See also htcp_clr_access for details on access control for
1308# cache purge (CLR) HTCP messages.
1309#
1310# NOTE: The default if no htcp_access lines are present is to
1311# deny all traffic. This default may cause problems with peers
1312# using the htcp option.
1313#
1314# This clause only supports fast acl types.
1315# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1316#
1317## Allow HTCP queries from local networks only
1318##htcp_access allow localnet
1319##htcp_access deny all
1320#Default:
1321# Deny, unless rules exist in squid.conf.
1322
1323# TAG: htcp_clr_access
1324# Allowing or Denying access to purge content using HTCP based
1325# on defined access lists.
1326# See htcp_access for details on general HTCP access control.
1327#
1328# htcp_clr_access allow|deny [!]aclname ...
1329#
1330# This clause only supports fast acl types.
1331# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1332#
1333## Allow HTCP CLR requests from trusted peers
1334#acl htcp_clr_peer src 192.0.2.2 2001:DB8::2
1335#htcp_clr_access allow htcp_clr_peer
1336#htcp_clr_access deny all
1337#Default:
1338# Deny, unless rules exist in squid.conf.
1339
1340# TAG: miss_access
1341# Determines whether network access is permitted when satisfying a request.
1342#
1343# For example;
1344# to force your neighbors to use you as a sibling instead of
1345# a parent.
1346#
1347# acl localclients src 192.0.2.0/24 2001:DB8::a:0/64
1348# miss_access deny !localclients
1349# miss_access allow all
1350#
1351# This means only your local clients are allowed to fetch relayed/MISS
1352# replies from the network and all other clients can only fetch cached
1353# objects (HITs).
1354#
1355# The default for this setting allows all clients who passed the
1356# http_access rules to relay via this proxy.
1357#
1358# This clause only supports fast acl types.
1359# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1360#Default:
1361# Allow, unless rules exist in squid.conf.
1362
1363# TAG: ident_lookup_access
1364# A list of ACL elements which, if matched, cause an ident
1365# (RFC 931) lookup to be performed for this request. For
1366# example, you might choose to always perform ident lookups
1367# for your main multi-user Unix boxes, but not for your Macs
1368# and PCs. By default, ident lookups are not performed for
1369# any requests.
1370#
1371# To enable ident lookups for specific client addresses, you
1372# can follow this example:
1373#
1374# acl ident_aware_hosts src 198.168.1.0/24
1375# ident_lookup_access allow ident_aware_hosts
1376# ident_lookup_access deny all
1377#
1378# Only src type ACL checks are fully supported. A srcdomain
1379# ACL might work at times, but it will not always provide
1380# the correct result.
1381#
1382# This clause only supports fast acl types.
1383# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1384#Default:
1385# Unless rules exist in squid.conf, IDENT is not fetched.
1386
1387# TAG: reply_body_max_size size [acl acl...]
1388# This option specifies the maximum size of a reply body. It can be
1389# used to prevent users from downloading very large files, such as
1390# MP3's and movies. When the reply headers are received, the
1391# reply_body_max_size lines are processed, and the first line where
1392# all (if any) listed ACLs are true is used as the maximum body size
1393# for this reply.
1394#
1395# This size is checked twice. First when we get the reply headers,
1396# we check the content-length value. If the content length value exists
1397# and is larger than the allowed size, the request is denied and the
1398# user receives an error message that says "the request or reply
1399# is too large." If there is no content-length, and the reply
1400# size exceeds this limit, the client's connection is just closed
1401# and they will receive a partial reply.
1402#
1403# WARNING: downstream caches probably can not detect a partial reply
1404# if there is no content-length header, so they will cache
1405# partial responses and give them out as hits. You should NOT
1406# use this option if you have downstream caches.
1407#
1408# WARNING: A maximum size smaller than the size of squid's error messages
1409# will cause an infinite loop and crash squid. Ensure that the smallest
1410# non-zero value you use is greater that the maximum header size plus
1411# the size of your largest error page.
1412#
1413# If you set this parameter none (the default), there will be
1414# no limit imposed.
1415#
1416# Configuration Format is:
1417# reply_body_max_size SIZE UNITS [acl ...]
1418# ie.
1419# reply_body_max_size 10 MB
1420#
1421#Default:
1422# No limit is applied.
1423
1424# NETWORK OPTIONS
1425# -----------------------------------------------------------------------------
1426
1427# TAG: http_port
1428# Usage: port [mode] [options]
1429# hostname:port [mode] [options]
1430# 1.2.3.4:port [mode] [options]
1431#
1432# The socket addresses where Squid will listen for HTTP client
1433# requests. You may specify multiple socket addresses.
1434# There are three forms: port alone, hostname with port, and
1435# IP address with port. If you specify a hostname or IP
1436# address, Squid binds the socket to that specific
1437# address. Most likely, you do not need to bind to a specific
1438# address, so you can use the port number alone.
1439#
1440# If you are running Squid in accelerator mode, you
1441# probably want to listen on port 80 also, or instead.
1442#
1443# The -a command line option may be used to specify additional
1444# port(s) where Squid listens for proxy request. Such ports will
1445# be plain proxy ports with no options.
1446#
1447# You may specify multiple socket addresses on multiple lines.
1448#
1449# Modes:
1450#
1451# intercept Support for IP-Layer NAT interception delivering
1452# traffic to this Squid port.
1453# NP: disables authentication on the port.
1454#
1455# tproxy Support Linux TPROXY (or BSD divert-to) with spoofing
1456# of outgoing connections using the client IP address.
1457# NP: disables authentication on the port.
1458#
1459# accel Accelerator / reverse proxy mode
1460#
1461# ssl-bump For each CONNECT request allowed by ssl_bump ACLs,
1462# establish secure connection with the client and with
1463# the server, decrypt HTTPS messages as they pass through
1464# Squid, and treat them as unencrypted HTTP messages,
1465# becoming the man-in-the-middle.
1466#
1467# The ssl_bump option is required to fully enable
1468# bumping of CONNECT requests.
1469#
1470# Omitting the mode flag causes default forward proxy mode to be used.
1471#
1472#
1473# Accelerator Mode Options:
1474#
1475# defaultsite=domainname
1476# What to use for the Host: header if it is not present
1477# in a request. Determines what site (not origin server)
1478# accelerators should consider the default.
1479#
1480# no-vhost Disable using HTTP/1.1 Host header for virtual domain support.
1481#
1482# protocol= Protocol to reconstruct accelerated and intercepted
1483# requests with. Defaults to HTTP/1.1 for http_port and
1484# HTTPS/1.1 for https_port.
1485# When an unsupported value is configured Squid will
1486# produce a FATAL error.
1487# Values: HTTP or HTTP/1.1, HTTPS or HTTPS/1.1
1488#
1489# vport Virtual host port support. Using the http_port number
1490# instead of the port passed on Host: headers.
1491#
1492# vport=NN Virtual host port support. Using the specified port
1493# number instead of the port passed on Host: headers.
1494#
1495# act-as-origin
1496# Act as if this Squid is the origin server.
1497# This currently means generate new Date: and Expires:
1498# headers on HIT instead of adding Age:.
1499#
1500# ignore-cc Ignore request Cache-Control headers.
1501#
1502# WARNING: This option violates HTTP specifications if
1503# used in non-accelerator setups.
1504#
1505# allow-direct Allow direct forwarding in accelerator mode. Normally
1506# accelerated requests are denied direct forwarding as if
1507# never_direct was used.
1508#
1509# WARNING: this option opens accelerator mode to security
1510# vulnerabilities usually only affecting in interception
1511# mode. Make sure to protect forwarding with suitable
1512# http_access rules when using this.
1513#
1514#
1515# SSL Bump Mode Options:
1516# In addition to these options ssl-bump requires TLS/SSL options.
1517#
1518# generate-host-certificates[=<on|off>]
1519# Dynamically create SSL server certificates for the
1520# destination hosts of bumped CONNECT requests.When
1521# enabled, the cert and key options are used to sign
1522# generated certificates. Otherwise generated
1523# certificate will be selfsigned.
1524# If there is a CA certificate lifetime of the generated
1525# certificate equals lifetime of the CA certificate. If
1526# generated certificate is selfsigned lifetime is three
1527# years.
1528# This option is enabled by default when ssl-bump is used.
1529# See the ssl-bump option above for more information.
1530#
1531# dynamic_cert_mem_cache_size=SIZE
1532# Approximate total RAM size spent on cached generated
1533# certificates. If set to zero, caching is disabled. The
1534# default value is 4MB.
1535#
1536# TLS / SSL Options:
1537#
1538# cert= Path to SSL certificate (PEM format).
1539#
1540# key= Path to SSL private key file (PEM format)
1541# if not specified, the certificate file is
1542# assumed to be a combined certificate and
1543# key file.
1544#
1545# version= The version of SSL/TLS supported
1546# 1 automatic (default)
1547# 2 SSLv2 only
1548# 3 SSLv3 only
1549# 4 TLSv1.0 only
1550# 5 TLSv1.1 only
1551# 6 TLSv1.2 only
1552#
1553# cipher= Colon separated list of supported ciphers.
1554# NOTE: some ciphers such as EDH ciphers depend on
1555# additional settings. If those settings are
1556# omitted the ciphers may be silently ignored
1557# by the OpenSSL library.
1558#
1559# options= Various SSL implementation options. The most important
1560# being:
1561# NO_SSLv2 Disallow the use of SSLv2
1562# NO_SSLv3 Disallow the use of SSLv3
1563# NO_TLSv1 Disallow the use of TLSv1.0
1564# NO_TLSv1_1 Disallow the use of TLSv1.1
1565# NO_TLSv1_2 Disallow the use of TLSv1.2
1566# SINGLE_DH_USE Always create a new key when using
1567# temporary/ephemeral DH key exchanges
1568# NO_TICKET Disables TLS tickets extension
1569#
1570# SINGLE_ECDH_USE
1571# Enable ephemeral ECDH key exchange.
1572# The adopted curve should be specified
1573# using the tls-dh option.
1574#
1575# ALL Enable various bug workarounds
1576# suggested as "harmless" by OpenSSL
1577# Be warned that this reduces SSL/TLS
1578# strength to some attacks.
1579# See OpenSSL SSL_CTX_set_options documentation for a
1580# complete list of options.
1581#
1582# clientca= File containing the list of CAs to use when
1583# requesting a client certificate.
1584#
1585# cafile= File containing additional CA certificates to
1586# use when verifying client certificates. If unset
1587# clientca will be used.
1588#
1589# capath= Directory containing additional CA certificates
1590# and CRL lists to use when verifying client certificates.
1591#
1592# crlfile= File of additional CRL lists to use when verifying
1593# the client certificate, in addition to CRLs stored in
1594# the capath. Implies VERIFY_CRL flag below.
1595#
1596# tls-dh=[curve:]file
1597# File containing DH parameters for temporary/ephemeral DH key
1598# exchanges, optionally prefixed by a curve for ephemeral ECDH
1599# key exchanges.
1600# See OpenSSL documentation for details on how to create the
1601# DH parameter file. Supported curves for ECDH can be listed
1602# using the "openssl ecparam -list_curves" command.
1603# WARNING: EDH and EECDH ciphers will be silently disabled if
1604# this option is not set.
1605#
1606# sslflags= Various flags modifying the use of SSL:
1607# DELAYED_AUTH
1608# Don't request client certificates
1609# immediately, but wait until acl processing
1610# requires a certificate (not yet implemented).
1611# NO_DEFAULT_CA
1612# Don't use the default CA lists built in
1613# to OpenSSL.
1614# NO_SESSION_REUSE
1615# Don't allow for session reuse. Each connection
1616# will result in a new SSL session.
1617# VERIFY_CRL
1618# Verify CRL lists when accepting client
1619# certificates.
1620# VERIFY_CRL_ALL
1621# Verify CRL lists for all certificates in the
1622# client certificate chain.
1623#
1624# sslcontext= SSL session ID context identifier.
1625#
1626# Other Options:
1627#
1628# connection-auth[=on|off]
1629# use connection-auth=off to tell Squid to prevent
1630# forwarding Microsoft connection oriented authentication
1631# (NTLM, Negotiate and Kerberos)
1632#
1633# disable-pmtu-discovery=
1634# Control Path-MTU discovery usage:
1635# off lets OS decide on what to do (default).
1636# transparent disable PMTU discovery when transparent
1637# support is enabled.
1638# always disable always PMTU discovery.
1639#
1640# In many setups of transparently intercepting proxies
1641# Path-MTU discovery can not work on traffic towards the
1642# clients. This is the case when the intercepting device
1643# does not fully track connections and fails to forward
1644# ICMP must fragment messages to the cache server. If you
1645# have such setup and experience that certain clients
1646# sporadically hang or never complete requests set
1647# disable-pmtu-discovery option to 'transparent'.
1648#
1649# name= Specifies a internal name for the port. Defaults to
1650# the port specification (port or addr:port)
1651#
1652# tcpkeepalive[=idle,interval,timeout]
1653# Enable TCP keepalive probes of idle connections.
1654# In seconds; idle is the initial time before TCP starts
1655# probing the connection, interval how often to probe, and
1656# timeout the time before giving up.
1657#
1658# require-proxy-header
1659# Require PROXY protocol version 1 or 2 connections.
1660# The proxy_protocol_access is required to whitelist
1661# downstream proxies which can be trusted.
1662#
1663# If you run Squid on a dual-homed machine with an internal
1664# and an external interface we recommend you to specify the
1665# internal address:port in http_port. This way Squid will only be
1666# visible on the internal address.
1667#
1668#
1669
1670# Squid normally listens to port 3128
1671http_port 3128
1672
1673# TAG: https_port
1674# Usage: [ip:]port cert=certificate.pem [key=key.pem] [mode] [options...]
1675#
1676# The socket address where Squid will listen for client requests made
1677# over TLS or SSL connections. Commonly referred to as HTTPS.
1678#
1679# This is most useful for situations where you are running squid in
1680# accelerator mode and you want to do the SSL work at the accelerator level.
1681#
1682# You may specify multiple socket addresses on multiple lines,
1683# each with their own SSL certificate and/or options.
1684#
1685# Modes:
1686#
1687# accel Accelerator / reverse proxy mode
1688#
1689# intercept Support for IP-Layer interception of
1690# outgoing requests without browser settings.
1691# NP: disables authentication and IPv6 on the port.
1692#
1693# tproxy Support Linux TPROXY for spoofing outgoing
1694# connections using the client IP address.
1695# NP: disables authentication and maybe IPv6 on the port.
1696#
1697# ssl-bump For each intercepted connection allowed by ssl_bump
1698# ACLs, establish a secure connection with the client and with
1699# the server, decrypt HTTPS messages as they pass through
1700# Squid, and treat them as unencrypted HTTP messages,
1701# becoming the man-in-the-middle.
1702#
1703# An "ssl_bump server-first" match is required to
1704# fully enable bumping of intercepted SSL connections.
1705#
1706# Requires tproxy or intercept.
1707#
1708# Omitting the mode flag causes default forward proxy mode to be used.
1709#
1710#
1711# See http_port for a list of generic options
1712#
1713#
1714# SSL Options:
1715#
1716# cert= Path to SSL certificate (PEM format).
1717#
1718# key= Path to SSL private key file (PEM format)
1719# if not specified, the certificate file is
1720# assumed to be a combined certificate and
1721# key file.
1722#
1723# version= The version of SSL/TLS supported
1724# 1 automatic (default)
1725# 2 SSLv2 only
1726# 3 SSLv3 only
1727# 4 TLSv1 only
1728#
1729# cipher= Colon separated list of supported ciphers.
1730#
1731# options= Various SSL engine options. The most important
1732# being:
1733# NO_SSLv2 Disallow the use of SSLv2
1734# NO_SSLv3 Disallow the use of SSLv3
1735# NO_TLSv1 Disallow the use of TLSv1
1736#
1737# SINGLE_DH_USE Always create a new key when using
1738# temporary/ephemeral DH key exchanges
1739#
1740# SINGLE_ECDH_USE
1741# Enable ephemeral ECDH key exchange.
1742# The adopted curve should be specified
1743# using the tls-dh option.
1744#
1745# See src/ssl_support.c or OpenSSL SSL_CTX_set_options
1746# documentation for a complete list of options.
1747#
1748# clientca= File containing the list of CAs to use when
1749# requesting a client certificate.
1750#
1751# cafile= File containing additional CA certificates to
1752# use when verifying client certificates. If unset
1753# clientca will be used.
1754#
1755# capath= Directory containing additional CA certificates
1756# and CRL lists to use when verifying client certificates.
1757#
1758# crlfile= File of additional CRL lists to use when verifying
1759# the client certificate, in addition to CRLs stored in
1760# the capath. Implies VERIFY_CRL flag below.
1761#
1762# tls-dh=[curve:]file
1763# File containing DH parameters for temporary/ephemeral DH key
1764# exchanges, optionally prefixed by a curve for ephemeral ECDH
1765# key exchanges.
1766#
1767# sslflags= Various flags modifying the use of SSL:
1768# DELAYED_AUTH
1769# Don't request client certificates
1770# immediately, but wait until acl processing
1771# requires a certificate (not yet implemented).
1772# NO_DEFAULT_CA
1773# Don't use the default CA lists built in
1774# to OpenSSL.
1775# NO_SESSION_REUSE
1776# Don't allow for session reuse. Each connection
1777# will result in a new SSL session.
1778# VERIFY_CRL
1779# Verify CRL lists when accepting client
1780# certificates.
1781# VERIFY_CRL_ALL
1782# Verify CRL lists for all certificates in the
1783# client certificate chain.
1784#
1785# sslcontext= SSL session ID context identifier.
1786#
1787# generate-host-certificates[=<on|off>]
1788# Dynamically create SSL server certificates for the
1789# destination hosts of bumped SSL requests.When
1790# enabled, the cert and key options are used to sign
1791# generated certificates. Otherwise generated
1792# certificate will be selfsigned.
1793# If there is CA certificate life time of generated
1794# certificate equals lifetime of CA certificate. If
1795# generated certificate is selfsigned lifetime is three
1796# years.
1797# This option is enabled by default when SslBump is used.
1798# See the sslBump option above for more information.
1799#
1800# dynamic_cert_mem_cache_size=SIZE
1801# Approximate total RAM size spent on cached generated
1802# certificates. If set to zero, caching is disabled. The
1803# default value is 4MB.
1804#
1805# See http_port for a list of available options.
1806#Default:
1807# none
1808
1809# TAG: ftp_port
1810# Enables Native FTP proxy by specifying the socket address where Squid
1811# listens for FTP client requests. See http_port directive for various
1812# ways to specify the listening address and mode.
1813#
1814# Usage: ftp_port address [mode] [options]
1815#
1816# WARNING: This is a new, experimental, complex feature that has seen
1817# limited production exposure. Some Squid modules (e.g., caching) do not
1818# currently work with native FTP proxying, and many features have not
1819# even been tested for compatibility. Test well before deploying!
1820#
1821# Native FTP proxying differs substantially from proxying HTTP requests
1822# with ftp:// URIs because Squid works as an FTP server and receives
1823# actual FTP commands (rather than HTTP requests with FTP URLs).
1824#
1825# Native FTP commands accepted at ftp_port are internally converted or
1826# wrapped into HTTP-like messages. The same happens to Native FTP
1827# responses received from FTP origin servers. Those HTTP-like messages
1828# are shoveled through regular access control and adaptation layers
1829# between the FTP client and the FTP origin server. This allows Squid to
1830# examine, adapt, block, and log FTP exchanges. Squid reuses most HTTP
1831# mechanisms when shoveling wrapped FTP messages. For example,
1832# http_access and adaptation_access directives are used.
1833#
1834# Modes:
1835#
1836# intercept Same as http_port intercept. The FTP origin address is
1837# determined based on the intended destination of the
1838# intercepted connection.
1839#
1840# tproxy Support Linux TPROXY for spoofing outgoing
1841# connections using the client IP address.
1842# NP: disables authentication and maybe IPv6 on the port.
1843#
1844# By default (i.e., without an explicit mode option), Squid extracts the
1845# FTP origin address from the login@origin parameter of the FTP USER
1846# command. Many popular FTP clients support such native FTP proxying.
1847#
1848# Options:
1849#
1850# name=token Specifies an internal name for the port. Defaults to
1851# the port address. Usable with myportname ACL.
1852#
1853# ftp-track-dirs
1854# Enables tracking of FTP directories by injecting extra
1855# PWD commands and adjusting Request-URI (in wrapping
1856# HTTP requests) to reflect the current FTP server
1857# directory. Tracking is disabled by default.
1858#
1859# protocol=FTP Protocol to reconstruct accelerated and intercepted
1860# requests with. Defaults to FTP. No other accepted
1861# values have been tested with. An unsupported value
1862# results in a FATAL error. Accepted values are FTP,
1863# HTTP (or HTTP/1.1), and HTTPS (or HTTPS/1.1).
1864#
1865# Other http_port modes and options that are not specific to HTTP and
1866# HTTPS may also work.
1867#Default:
1868# none
1869
1870# TAG: tcp_outgoing_tos
1871# Allows you to select a TOS/Diffserv value for packets outgoing
1872# on the server side, based on an ACL.
1873#
1874# tcp_outgoing_tos ds-field [!]aclname ...
1875#
1876# Example where normal_service_net uses the TOS value 0x00
1877# and good_service_net uses 0x20
1878#
1879# acl normal_service_net src 10.0.0.0/24
1880# acl good_service_net src 10.0.1.0/24
1881# tcp_outgoing_tos 0x00 normal_service_net
1882# tcp_outgoing_tos 0x20 good_service_net
1883#
1884# TOS/DSCP values really only have local significance - so you should
1885# know what you're specifying. For more information, see RFC2474,
1886# RFC2475, and RFC3260.
1887#
1888# The TOS/DSCP byte must be exactly that - a octet value 0 - 255, or
1889# "default" to use whatever default your host has.
1890# Note that only multiples of 4 are usable as the two rightmost bits have
1891# been redefined for use by ECN (RFC 3168 section 23.1).
1892# The squid parser will enforce this by masking away the ECN bits.
1893#
1894# Processing proceeds in the order specified, and stops at first fully
1895# matching line.
1896#
1897# Only fast ACLs are supported.
1898#Default:
1899# none
1900
1901# TAG: clientside_tos
1902# Allows you to select a TOS/DSCP value for packets being transmitted
1903# on the client-side, based on an ACL.
1904#
1905# clientside_tos ds-field [!]aclname ...
1906#
1907# Example where normal_service_net uses the TOS value 0x00
1908# and good_service_net uses 0x20
1909#
1910# acl normal_service_net src 10.0.0.0/24
1911# acl good_service_net src 10.0.1.0/24
1912# clientside_tos 0x00 normal_service_net
1913# clientside_tos 0x20 good_service_net
1914#
1915# Note: This feature is incompatible with qos_flows. Any TOS values set here
1916# will be overwritten by TOS values in qos_flows.
1917#
1918# The TOS/DSCP byte must be exactly that - a octet value 0 - 255, or
1919# "default" to use whatever default your host has.
1920# Note that only multiples of 4 are usable as the two rightmost bits have
1921# been redefined for use by ECN (RFC 3168 section 23.1).
1922# The squid parser will enforce this by masking away the ECN bits.
1923#
1924#Default:
1925# none
1926
1927# TAG: tcp_outgoing_mark
1928# Note: This option is only available if Squid is rebuilt with the
1929# Packet MARK (Linux)
1930#
1931# Allows you to apply a Netfilter mark value to outgoing packets
1932# on the server side, based on an ACL.
1933#
1934# tcp_outgoing_mark mark-value [!]aclname ...
1935#
1936# Example where normal_service_net uses the mark value 0x00
1937# and good_service_net uses 0x20
1938#
1939# acl normal_service_net src 10.0.0.0/24
1940# acl good_service_net src 10.0.1.0/24
1941# tcp_outgoing_mark 0x00 normal_service_net
1942# tcp_outgoing_mark 0x20 good_service_net
1943#
1944# Only fast ACLs are supported.
1945#Default:
1946# none
1947
1948# TAG: clientside_mark
1949# Note: This option is only available if Squid is rebuilt with the
1950# Packet MARK (Linux)
1951#
1952# Allows you to apply a Netfilter mark value to packets being transmitted
1953# on the client-side, based on an ACL.
1954#
1955# clientside_mark mark-value [!]aclname ...
1956#
1957# Example where normal_service_net uses the mark value 0x00
1958# and good_service_net uses 0x20
1959#
1960# acl normal_service_net src 10.0.0.0/24
1961# acl good_service_net src 10.0.1.0/24
1962# clientside_mark 0x00 normal_service_net
1963# clientside_mark 0x20 good_service_net
1964#
1965# Note: This feature is incompatible with qos_flows. Any mark values set here
1966# will be overwritten by mark values in qos_flows.
1967#Default:
1968# none
1969
1970# TAG: qos_flows
1971# Allows you to select a TOS/DSCP value to mark outgoing
1972# connections to the client, based on where the reply was sourced.
1973# For platforms using netfilter, allows you to set a netfilter mark
1974# value instead of, or in addition to, a TOS value.
1975#
1976# By default this functionality is disabled. To enable it with the default
1977# settings simply use "qos_flows mark" or "qos_flows tos". Default
1978# settings will result in the netfilter mark or TOS value being copied
1979# from the upstream connection to the client. Note that it is the connection
1980# CONNMARK value not the packet MARK value that is copied.
1981#
1982# It is not currently possible to copy the mark or TOS value from the
1983# client to the upstream connection request.
1984#
1985# TOS values really only have local significance - so you should
1986# know what you're specifying. For more information, see RFC2474,
1987# RFC2475, and RFC3260.
1988#
1989# The TOS/DSCP byte must be exactly that - a octet value 0 - 255.
1990# Note that only multiples of 4 are usable as the two rightmost bits have
1991# been redefined for use by ECN (RFC 3168 section 23.1).
1992# The squid parser will enforce this by masking away the ECN bits.
1993#
1994# Mark values can be any unsigned 32-bit integer value.
1995#
1996# This setting is configured by setting the following values:
1997#
1998# tos|mark Whether to set TOS or netfilter mark values
1999#
2000# local-hit=0xFF Value to mark local cache hits.
2001#
2002# sibling-hit=0xFF Value to mark hits from sibling peers.
2003#
2004# parent-hit=0xFF Value to mark hits from parent peers.
2005#
2006# miss=0xFF[/mask] Value to mark cache misses. Takes precedence
2007# over the preserve-miss feature (see below), unless
2008# mask is specified, in which case only the bits
2009# specified in the mask are written.
2010#
2011# The TOS variant of the following features are only possible on Linux
2012# and require your kernel to be patched with the TOS preserving ZPH
2013# patch, available from http://zph.bratcheda.org
2014# No patch is needed to preserve the netfilter mark, which will work
2015# with all variants of netfilter.
2016#
2017# disable-preserve-miss
2018# This option disables the preservation of the TOS or netfilter
2019# mark. By default, the existing TOS or netfilter mark value of
2020# the response coming from the remote server will be retained
2021# and masked with miss-mark.
2022# NOTE: in the case of a netfilter mark, the mark must be set on
2023# the connection (using the CONNMARK target) not on the packet
2024# (MARK target).
2025#
2026# miss-mask=0xFF
2027# Allows you to mask certain bits in the TOS or mark value
2028# received from the remote server, before copying the value to
2029# the TOS sent towards clients.
2030# Default for tos: 0xFF (TOS from server is not changed).
2031# Default for mark: 0xFFFFFFFF (mark from server is not changed).
2032#
2033# All of these features require the --enable-zph-qos compilation flag
2034# (enabled by default). Netfilter marking also requires the
2035# libnetfilter_conntrack libraries (--with-netfilter-conntrack) and
2036# libcap 2.09+ (--with-libcap).
2037#
2038#Default:
2039# none
2040
2041# TAG: tcp_outgoing_address
2042# Allows you to map requests to different outgoing IP addresses
2043# based on the username or source address of the user making
2044# the request.
2045#
2046# tcp_outgoing_address ipaddr [[!]aclname] ...
2047#
2048# For example;
2049# Forwarding clients with dedicated IPs for certain subnets.
2050#
2051# acl normal_service_net src 10.0.0.0/24
2052# acl good_service_net src 10.0.2.0/24
2053#
2054# tcp_outgoing_address 2001:db8::c001 good_service_net
2055# tcp_outgoing_address 10.1.0.2 good_service_net
2056#
2057# tcp_outgoing_address 2001:db8::beef normal_service_net
2058# tcp_outgoing_address 10.1.0.1 normal_service_net
2059#
2060# tcp_outgoing_address 2001:db8::1
2061# tcp_outgoing_address 10.1.0.3
2062#
2063# Processing proceeds in the order specified, and stops at first fully
2064# matching line.
2065#
2066# Squid will add an implicit IP version test to each line.
2067# Requests going to IPv4 websites will use the outgoing 10.1.0.* addresses.
2068# Requests going to IPv6 websites will use the outgoing 2001:db8:* addresses.
2069#
2070#
2071# NOTE: The use of this directive using client dependent ACLs is
2072# incompatible with the use of server side persistent connections. To
2073# ensure correct results it is best to set server_persistent_connections
2074# to off when using this directive in such configurations.
2075#
2076# NOTE: The use of this directive to set a local IP on outgoing TCP links
2077# is incompatible with using TPROXY to set client IP out outbound TCP links.
2078# When needing to contact peers use the no-tproxy cache_peer option and the
2079# client_dst_passthru directive re-enable normal forwarding such as this.
2080#
2081#Default:
2082# Address selection is performed by the operating system.
2083
2084# TAG: host_verify_strict
2085# Regardless of this option setting, when dealing with intercepted
2086# traffic, Squid always verifies that the destination IP address matches
2087# the Host header domain or IP (called 'authority form URL').
2088#
2089# This enforcement is performed to satisfy a MUST-level requirement in
2090# RFC 2616 section 14.23: "The Host field value MUST represent the naming
2091# authority of the origin server or gateway given by the original URL".
2092#
2093# When set to ON:
2094# Squid always responds with an HTTP 409 (Conflict) error
2095# page and logs a security warning if there is no match.
2096#
2097# Squid verifies that the destination IP address matches
2098# the Host header for forward-proxy and reverse-proxy traffic
2099# as well. For those traffic types, Squid also enables the
2100# following checks, comparing the corresponding Host header
2101# and Request-URI components:
2102#
2103# * The host names (domain or IP) must be identical,
2104# but valueless or missing Host header disables all checks.
2105# For the two host names to match, both must be either IP
2106# or FQDN.
2107#
2108# * Port numbers must be identical, but if a port is missing
2109# the scheme-default port is assumed.
2110#
2111#
2112# When set to OFF (the default):
2113# Squid allows suspicious requests to continue but logs a
2114# security warning and blocks caching of the response.
2115#
2116# * Forward-proxy traffic is not checked at all.
2117#
2118# * Reverse-proxy traffic is not checked at all.
2119#
2120# * Intercepted traffic which passes verification is handled
2121# according to client_dst_passthru.
2122#
2123# * Intercepted requests which fail verification are sent
2124# to the client original destination instead of DIRECT.
2125# This overrides 'client_dst_passthru off'.
2126#
2127# For now suspicious intercepted CONNECT requests are always
2128# responded to with an HTTP 409 (Conflict) error page.
2129#
2130#
2131# SECURITY NOTE:
2132#
2133# As described in CVE-2009-0801 when the Host: header alone is used
2134# to determine the destination of a request it becomes trivial for
2135# malicious scripts on remote websites to bypass browser same-origin
2136# security policy and sandboxing protections.
2137#
2138# The cause of this is that such applets are allowed to perform their
2139# own HTTP stack, in which case the same-origin policy of the browser
2140# sandbox only verifies that the applet tries to contact the same IP
2141# as from where it was loaded at the IP level. The Host: header may
2142# be different from the connected IP and approved origin.
2143#
2144#Default:
2145# host_verify_strict off
2146
2147# TAG: client_dst_passthru
2148# With NAT or TPROXY intercepted traffic Squid may pass the request
2149# directly to the original client destination IP or seek a faster
2150# source using the HTTP Host header.
2151#
2152# Using Host to locate alternative servers can provide faster
2153# connectivity with a range of failure recovery options.
2154# But can also lead to connectivity trouble when the client and
2155# server are attempting stateful interactions unaware of the proxy.
2156#
2157# This option (on by default) prevents alternative DNS entries being
2158# located to send intercepted traffic DIRECT to an origin server.
2159# The clients original destination IP and port will be used instead.
2160#
2161# Regardless of this option setting, when dealing with intercepted
2162# traffic Squid will verify the Host: header and any traffic which
2163# fails Host verification will be treated as if this option were ON.
2164#
2165# see host_verify_strict for details on the verification process.
2166#Default:
2167# client_dst_passthru on
2168
2169# SSL OPTIONS
2170# -----------------------------------------------------------------------------
2171
2172# TAG: ssl_unclean_shutdown
2173# Some browsers (especially MSIE) bugs out on SSL shutdown
2174# messages.
2175#Default:
2176# ssl_unclean_shutdown off
2177
2178# TAG: ssl_engine
2179# The OpenSSL engine to use. You will need to set this if you
2180# would like to use hardware SSL acceleration for example.
2181#Default:
2182# none
2183
2184# TAG: sslproxy_client_certificate
2185# Client SSL Certificate to use when proxying https:// URLs
2186#Default:
2187# none
2188
2189# TAG: sslproxy_client_key
2190# Client SSL Key to use when proxying https:// URLs
2191#Default:
2192# none
2193
2194# TAG: sslproxy_version
2195# SSL version level to use when proxying https:// URLs
2196#
2197# The versions of SSL/TLS supported:
2198#
2199# 1 automatic (default)
2200# 2 SSLv2 only
2201# 3 SSLv3 only
2202# 4 TLSv1.0 only
2203# 5 TLSv1.1 only
2204# 6 TLSv1.2 only
2205#Default:
2206# automatic SSL/TLS version negotiation
2207
2208# TAG: sslproxy_options
2209# Colon (:) or comma (,) separated list of SSL implementation options
2210# to use when proxying https:// URLs
2211#
2212# The most important being:
2213#
2214# NO_SSLv2 Disallow the use of SSLv2
2215# NO_SSLv3 Disallow the use of SSLv3
2216# NO_TLSv1 Disallow the use of TLSv1.0
2217# NO_TLSv1_1 Disallow the use of TLSv1.1
2218# NO_TLSv1_2 Disallow the use of TLSv1.2
2219# SINGLE_DH_USE
2220# Always create a new key when using temporary/ephemeral
2221# DH key exchanges
2222# SSL_OP_NO_TICKET
2223# Disable use of RFC5077 session tickets. Some servers
2224# may have problems understanding the TLS extension due
2225# to ambiguous specification in RFC4507.
2226# ALL Enable various bug workarounds suggested as "harmless"
2227# by OpenSSL. Be warned that this may reduce SSL/TLS
2228# strength to some attacks.
2229#
2230# See the OpenSSL SSL_CTX_set_options documentation for a
2231# complete list of possible options.
2232#
2233# WARNING: This directive takes a single token. If a space is used
2234# the value(s) after that space are SILENTLY IGNORED.
2235#Default:
2236# none
2237
2238# TAG: sslproxy_cipher
2239# SSL cipher list to use when proxying https:// URLs
2240#
2241# Colon separated list of supported ciphers.
2242#Default:
2243# none
2244
2245# TAG: sslproxy_cafile
2246# file containing CA certificates to use when verifying server
2247# certificates while proxying https:// URLs
2248#Default:
2249# none
2250
2251# TAG: sslproxy_capath
2252# directory containing CA certificates to use when verifying
2253# server certificates while proxying https:// URLs
2254#Default:
2255# none
2256
2257# TAG: sslproxy_session_ttl
2258# Sets the timeout value for SSL sessions
2259#Default:
2260# sslproxy_session_ttl 300
2261
2262# TAG: sslproxy_session_cache_size
2263# Sets the cache size to use for ssl session
2264#Default:
2265# sslproxy_session_cache_size 2 MB
2266
2267# TAG: sslproxy_foreign_intermediate_certs
2268# Many origin servers fail to send their full server certificate
2269# chain for verification, assuming the client already has or can
2270# easily locate any missing intermediate certificates.
2271#
2272# Squid uses the certificates from the specified file to fill in
2273# these missing chains when trying to validate origin server
2274# certificate chains.
2275#
2276# The file is expected to contain zero or more PEM-encoded
2277# intermediate certificates. These certificates are not treated
2278# as trusted root certificates, and any self-signed certificate in
2279# this file will be ignored.
2280#Default:
2281# none
2282
2283# TAG: sslproxy_cert_sign_hash
2284# Sets the hashing algorithm to use when signing generated certificates.
2285# Valid algorithm names depend on the OpenSSL library used. The following
2286# names are usually available: sha1, sha256, sha512, and md5. Please see
2287# your OpenSSL library manual for the available hashes. By default, Squids
2288# that support this option use sha256 hashes.
2289#
2290# Squid does not forcefully purge cached certificates that were generated
2291# with an algorithm other than the currently configured one. They remain
2292# in the cache, subject to the regular cache eviction policy, and become
2293# useful if the algorithm changes again.
2294#Default:
2295# none
2296
2297# TAG: ssl_bump
2298# This option is consulted when a CONNECT request is received on
2299# an http_port (or a new connection is intercepted at an
2300# https_port), provided that port was configured with an ssl-bump
2301# flag. The subsequent data on the connection is either treated as
2302# HTTPS and decrypted OR tunneled at TCP level without decryption,
2303# depending on the first matching bumping "action".
2304#
2305# ssl_bump <action> [!]acl ...
2306#
2307# The following bumping actions are currently supported:
2308#
2309# splice
2310# Become a TCP tunnel without decrypting proxied traffic.
2311# This is the default action.
2312#
2313# bump
2314# Establish a secure connection with the server and, using a
2315# mimicked server certificate, with the client.
2316#
2317# peek
2318# Receive client (step SslBump1) or server (step SslBump2)
2319# certificate while preserving the possibility of splicing the
2320# connection. Peeking at the server certificate (during step 2)
2321# usually precludes bumping of the connection at step 3.
2322#
2323# stare
2324# Receive client (step SslBump1) or server (step SslBump2)
2325# certificate while preserving the possibility of bumping the
2326# connection. Staring at the server certificate (during step 2)
2327# usually precludes splicing of the connection at step 3.
2328#
2329# terminate
2330# Close client and server connections.
2331#
2332# Backward compatibility actions available at step SslBump1:
2333#
2334# client-first
2335# Bump the connection. Establish a secure connection with the
2336# client first, then connect to the server. This old mode does
2337# not allow Squid to mimic server SSL certificate and does not
2338# work with intercepted SSL connections.
2339#
2340# server-first
2341# Bump the connection. Establish a secure connection with the
2342# server first, then establish a secure connection with the
2343# client, using a mimicked server certificate. Works with both
2344# CONNECT requests and intercepted SSL connections, but does
2345# not allow to make decisions based on SSL handshake info.
2346#
2347# peek-and-splice
2348# Decide whether to bump or splice the connection based on
2349# client-to-squid and server-to-squid SSL hello messages.
2350# XXX: Remove.
2351#
2352# none
2353# Same as the "splice" action.
2354#
2355# All ssl_bump rules are evaluated at each of the supported bumping
2356# steps. Rules with actions that are impossible at the current step are
2357# ignored. The first matching ssl_bump action wins and is applied at the
2358# end of the current step. If no rules match, the splice action is used.
2359# See the at_step ACL for a list of the supported SslBump steps.
2360#
2361# This clause supports both fast and slow acl types.
2362# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
2363#
2364# See also: http_port ssl-bump, https_port ssl-bump, and acl at_step.
2365#
2366#
2367# # Example: Bump all TLS connections except those originating from
2368# # localhost or those going to example.com.
2369#
2370# acl broken_sites ssl::server_name .example.com
2371# ssl_bump splice localhost
2372# ssl_bump splice broken_sites
2373# ssl_bump bump all
2374#Default:
2375# Become a TCP tunnel without decrypting proxied traffic.
2376
2377# TAG: sslproxy_flags
2378# Various flags modifying the use of SSL while proxying https:// URLs:
2379# DONT_VERIFY_PEER Accept certificates that fail verification.
2380# For refined control, see sslproxy_cert_error.
2381# NO_DEFAULT_CA Don't use the default CA list built in
2382# to OpenSSL.
2383#Default:
2384# none
2385
2386# TAG: sslproxy_cert_error
2387# Use this ACL to bypass server certificate validation errors.
2388#
2389# For example, the following lines will bypass all validation errors
2390# when talking to servers for example.com. All other
2391# validation errors will result in ERR_SECURE_CONNECT_FAIL error.
2392#
2393# acl BrokenButTrustedServers dstdomain example.com
2394# sslproxy_cert_error allow BrokenButTrustedServers
2395# sslproxy_cert_error deny all
2396#
2397# This clause only supports fast acl types.
2398# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
2399# Using slow acl types may result in server crashes
2400#
2401# Without this option, all server certificate validation errors
2402# terminate the transaction to protect Squid and the client.
2403#
2404# SQUID_X509_V_ERR_INFINITE_VALIDATION error cannot be bypassed
2405# but should not happen unless your OpenSSL library is buggy.
2406#
2407# SECURITY WARNING:
2408# Bypassing validation errors is dangerous because an
2409# error usually implies that the server cannot be trusted
2410# and the connection may be insecure.
2411#
2412# See also: sslproxy_flags and DONT_VERIFY_PEER.
2413#Default:
2414# Server certificate errors terminate the transaction.
2415
2416# TAG: sslproxy_cert_sign
2417#
2418# sslproxy_cert_sign <signing algorithm> acl ...
2419#
2420# The following certificate signing algorithms are supported:
2421#
2422# signTrusted
2423# Sign using the configured CA certificate which is usually
2424# placed in and trusted by end-user browsers. This is the
2425# default for trusted origin server certificates.
2426#
2427# signUntrusted
2428# Sign to guarantee an X509_V_ERR_CERT_UNTRUSTED browser error.
2429# This is the default for untrusted origin server certificates
2430# that are not self-signed (see ssl::certUntrusted).
2431#
2432# signSelf
2433# Sign using a self-signed certificate with the right CN to
2434# generate a X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT error in the
2435# browser. This is the default for self-signed origin server
2436# certificates (see ssl::certSelfSigned).
2437#
2438# This clause only supports fast acl types.
2439#
2440# When sslproxy_cert_sign acl(s) match, Squid uses the corresponding
2441# signing algorithm to generate the certificate and ignores all
2442# subsequent sslproxy_cert_sign options (the first match wins). If no
2443# acl(s) match, the default signing algorithm is determined by errors
2444# detected when obtaining and validating the origin server certificate.
2445#
2446# WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can
2447# be used with sslproxy_cert_adapt, but if and only if Squid is bumping a
2448# CONNECT request that carries a domain name. In all other cases (CONNECT
2449# to an IP address or an intercepted SSL connection), Squid cannot detect
2450# the domain mismatch at certificate generation time when
2451# bump-server-first is used.
2452#Default:
2453# none
2454
2455# TAG: sslproxy_cert_adapt
2456#
2457# sslproxy_cert_adapt <adaptation algorithm> acl ...
2458#
2459# The following certificate adaptation algorithms are supported:
2460#
2461# setValidAfter
2462# Sets the "Not After" property to the "Not After" property of
2463# the CA certificate used to sign generated certificates.
2464#
2465# setValidBefore
2466# Sets the "Not Before" property to the "Not Before" property of
2467# the CA certificate used to sign generated certificates.
2468#
2469# setCommonName or setCommonName{CN}
2470# Sets Subject.CN property to the host name specified as a
2471# CN parameter or, if no explicit CN parameter was specified,
2472# extracted from the CONNECT request. It is a misconfiguration
2473# to use setCommonName without an explicit parameter for
2474# intercepted or tproxied SSL connections.
2475#
2476# This clause only supports fast acl types.
2477#
2478# Squid first groups sslproxy_cert_adapt options by adaptation algorithm.
2479# Within a group, when sslproxy_cert_adapt acl(s) match, Squid uses the
2480# corresponding adaptation algorithm to generate the certificate and
2481# ignores all subsequent sslproxy_cert_adapt options in that algorithm's
2482# group (i.e., the first match wins within each algorithm group). If no
2483# acl(s) match, the default mimicking action takes place.
2484#
2485# WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can
2486# be used with sslproxy_cert_adapt, but if and only if Squid is bumping a
2487# CONNECT request that carries a domain name. In all other cases (CONNECT
2488# to an IP address or an intercepted SSL connection), Squid cannot detect
2489# the domain mismatch at certificate generation time when
2490# bump-server-first is used.
2491#Default:
2492# none
2493
2494# TAG: sslpassword_program
2495# Specify a program used for entering SSL key passphrases
2496# when using encrypted SSL certificate keys. If not specified
2497# keys must either be unencrypted, or Squid started with the -N
2498# option to allow it to query interactively for the passphrase.
2499#
2500# The key file name is given as argument to the program allowing
2501# selection of the right password if you have multiple encrypted
2502# keys.
2503#Default:
2504# none
2505
2506# OPTIONS RELATING TO EXTERNAL SSL_CRTD
2507# -----------------------------------------------------------------------------
2508
2509# TAG: sslcrtd_program
2510# Specify the location and options of the executable for ssl_crtd process.
2511# /usr/lib/squid/ssl_crtd program requires -s and -M parameters
2512# For more information use:
2513# /usr/lib/squid/ssl_crtd -h
2514#Default:
2515# sslcrtd_program /usr/lib/squid/ssl_crtd -s /var/lib/ssl_db -M 4MB
2516
2517# TAG: sslcrtd_children
2518# The maximum number of processes spawn to service ssl server.
2519# The maximum this may be safely set to is 32.
2520#
2521# The startup= and idle= options allow some measure of skew in your
2522# tuning.
2523#
2524# startup=N
2525#
2526# Sets the minimum number of processes to spawn when Squid
2527# starts or reconfigures. When set to zero the first request will
2528# cause spawning of the first child process to handle it.
2529#
2530# Starting too few children temporary slows Squid under load while it
2531# tries to spawn enough additional processes to cope with traffic.
2532#
2533# idle=N
2534#
2535# Sets a minimum of how many processes Squid is to try and keep available
2536# at all times. When traffic begins to rise above what the existing
2537# processes can handle this many more will be spawned up to the maximum
2538# configured. A minimum setting of 1 is required.
2539#
2540# You must have at least one ssl_crtd process.
2541#Default:
2542# sslcrtd_children 32 startup=5 idle=1
2543
2544# TAG: sslcrtvalidator_program
2545# Specify the location and options of the executable for ssl_crt_validator
2546# process.
2547#
2548# Usage: sslcrtvalidator_program [ttl=n] [cache=n] path ...
2549#
2550# Options:
2551# ttl=n TTL in seconds for cached results. The default is 60 secs
2552# cache=n limit the result cache size. The default value is 2048
2553#Default:
2554# none
2555
2556# TAG: sslcrtvalidator_children
2557# The maximum number of processes spawn to service SSL server.
2558# The maximum this may be safely set to is 32.
2559#
2560# The startup= and idle= options allow some measure of skew in your
2561# tuning.
2562#
2563# startup=N
2564#
2565# Sets the minimum number of processes to spawn when Squid
2566# starts or reconfigures. When set to zero the first request will
2567# cause spawning of the first child process to handle it.
2568#
2569# Starting too few children temporary slows Squid under load while it
2570# tries to spawn enough additional processes to cope with traffic.
2571#
2572# idle=N
2573#
2574# Sets a minimum of how many processes Squid is to try and keep available
2575# at all times. When traffic begins to rise above what the existing
2576# processes can handle this many more will be spawned up to the maximum
2577# configured. A minimum setting of 1 is required.
2578#
2579# concurrency=
2580#
2581# The number of requests each certificate validator helper can handle in
2582# parallel. A value of 0 indicates the certficate validator does not
2583# support concurrency. Defaults to 1.
2584#
2585# When this directive is set to a value >= 1 then the protocol
2586# used to communicate with the helper is modified to include
2587# a request ID in front of the request/response. The request
2588# ID from the request must be echoed back with the response
2589# to that request.
2590#
2591# You must have at least one ssl_crt_validator process.
2592#Default:
2593# sslcrtvalidator_children 32 startup=5 idle=1 concurrency=1
2594
2595# OPTIONS WHICH AFFECT THE NEIGHBOR SELECTION ALGORITHM
2596# -----------------------------------------------------------------------------
2597
2598# TAG: cache_peer
2599# To specify other caches in a hierarchy, use the format:
2600#
2601# cache_peer hostname type http-port icp-port [options]
2602#
2603# For example,
2604#
2605# # proxy icp
2606# # hostname type port port options
2607# # -------------------- -------- ----- ----- -----------
2608# cache_peer parent.foo.net parent 3128 3130 default
2609# cache_peer sib1.foo.net sibling 3128 3130 proxy-only
2610# cache_peer sib2.foo.net sibling 3128 3130 proxy-only
2611# cache_peer example.com parent 80 0 default
2612# cache_peer cdn.example.com sibling 3128 0
2613#
2614# type: either 'parent', 'sibling', or 'multicast'.
2615#
2616# proxy-port: The port number where the peer accept HTTP requests.
2617# For other Squid proxies this is usually 3128
2618# For web servers this is usually 80
2619#
2620# icp-port: Used for querying neighbor caches about objects.
2621# Set to 0 if the peer does not support ICP or HTCP.
2622# See ICP and HTCP options below for additional details.
2623#
2624#
2625# ==== ICP OPTIONS ====
2626#
2627# You MUST also set icp_port and icp_access explicitly when using these options.
2628# The defaults will prevent peer traffic using ICP.
2629#
2630#
2631# no-query Disable ICP queries to this neighbor.
2632#
2633# multicast-responder
2634# Indicates the named peer is a member of a multicast group.
2635# ICP queries will not be sent directly to the peer, but ICP
2636# replies will be accepted from it.
2637#
2638# closest-only Indicates that, for ICP_OP_MISS replies, we'll only forward
2639# CLOSEST_PARENT_MISSes and never FIRST_PARENT_MISSes.
2640#
2641# background-ping
2642# To only send ICP queries to this neighbor infrequently.
2643# This is used to keep the neighbor round trip time updated
2644# and is usually used in conjunction with weighted-round-robin.
2645#
2646#
2647# ==== HTCP OPTIONS ====
2648#
2649# You MUST also set htcp_port and htcp_access explicitly when using these options.
2650# The defaults will prevent peer traffic using HTCP.
2651#
2652#
2653# htcp Send HTCP, instead of ICP, queries to the neighbor.
2654# You probably also want to set the "icp-port" to 4827
2655# instead of 3130. This directive accepts a comma separated
2656# list of options described below.
2657#
2658# htcp=oldsquid Send HTCP to old Squid versions (2.5 or earlier).
2659#
2660# htcp=no-clr Send HTCP to the neighbor but without
2661# sending any CLR requests. This cannot be used with
2662# only-clr.
2663#
2664# htcp=only-clr Send HTCP to the neighbor but ONLY CLR requests.
2665# This cannot be used with no-clr.
2666#
2667# htcp=no-purge-clr
2668# Send HTCP to the neighbor including CLRs but only when
2669# they do not result from PURGE requests.
2670#
2671# htcp=forward-clr
2672# Forward any HTCP CLR requests this proxy receives to the peer.
2673#
2674#
2675# ==== PEER SELECTION METHODS ====
2676#
2677# The default peer selection method is ICP, with the first responding peer
2678# being used as source. These options can be used for better load balancing.
2679#
2680#
2681# default This is a parent cache which can be used as a "last-resort"
2682# if a peer cannot be located by any of the peer-selection methods.
2683# If specified more than once, only the first is used.
2684#
2685# round-robin Load-Balance parents which should be used in a round-robin
2686# fashion in the absence of any ICP queries.
2687# weight=N can be used to add bias.
2688#
2689# weighted-round-robin
2690# Load-Balance parents which should be used in a round-robin
2691# fashion with the frequency of each parent being based on the
2692# round trip time. Closer parents are used more often.
2693# Usually used for background-ping parents.
2694# weight=N can be used to add bias.
2695#
2696# carp Load-Balance parents which should be used as a CARP array.
2697# The requests will be distributed among the parents based on the
2698# CARP load balancing hash function based on their weight.
2699#
2700# userhash Load-balance parents based on the client proxy_auth or ident username.
2701#
2702# sourcehash Load-balance parents based on the client source IP.
2703#
2704# multicast-siblings
2705# To be used only for cache peers of type "multicast".
2706# ALL members of this multicast group have "sibling"
2707# relationship with it, not "parent". This is to a multicast
2708# group when the requested object would be fetched only from
2709# a "parent" cache, anyway. It's useful, e.g., when
2710# configuring a pool of redundant Squid proxies, being
2711# members of the same multicast group.
2712#
2713#
2714# ==== PEER SELECTION OPTIONS ====
2715#
2716# weight=N use to affect the selection of a peer during any weighted
2717# peer-selection mechanisms.
2718# The weight must be an integer; default is 1,
2719# larger weights are favored more.
2720# This option does not affect parent selection if a peering
2721# protocol is not in use.
2722#
2723# basetime=N Specify a base amount to be subtracted from round trip
2724# times of parents.
2725# It is subtracted before division by weight in calculating
2726# which parent to fectch from. If the rtt is less than the
2727# base time the rtt is set to a minimal value.
2728#
2729# ttl=N Specify a TTL to use when sending multicast ICP queries
2730# to this address.
2731# Only useful when sending to a multicast group.
2732# Because we don't accept ICP replies from random
2733# hosts, you must configure other group members as
2734# peers with the 'multicast-responder' option.
2735#
2736# no-delay To prevent access to this neighbor from influencing the
2737# delay pools.
2738#
2739# digest-url=URL Tell Squid to fetch the cache digest (if digests are
2740# enabled) for this host from the specified URL rather
2741# than the Squid default location.
2742#
2743#
2744# ==== CARP OPTIONS ====
2745#
2746# carp-key=key-specification
2747# use a different key than the full URL to hash against the peer.
2748# the key-specification is a comma-separated list of the keywords
2749# scheme, host, port, path, params
2750# Order is not important.
2751#
2752# ==== ACCELERATOR / REVERSE-PROXY OPTIONS ====
2753#
2754# originserver Causes this parent to be contacted as an origin server.
2755# Meant to be used in accelerator setups when the peer
2756# is a web server.
2757#
2758# forceddomain=name
2759# Set the Host header of requests forwarded to this peer.
2760# Useful in accelerator setups where the server (peer)
2761# expects a certain domain name but clients may request
2762# others. ie example.com or www.example.com
2763#
2764# no-digest Disable request of cache digests.
2765#
2766# no-netdb-exchange
2767# Disables requesting ICMP RTT database (NetDB).
2768#
2769#
2770# ==== AUTHENTICATION OPTIONS ====
2771#
2772# login=user:password
2773# If this is a personal/workgroup proxy and your parent
2774# requires proxy authentication.
2775#
2776# Note: The string can include URL escapes (i.e. %20 for
2777# spaces). This also means % must be written as %%.
2778#
2779# login=PASSTHRU
2780# Send login details received from client to this peer.
2781# Both Proxy- and WWW-Authorization headers are passed
2782# without alteration to the peer.
2783# Authentication is not required by Squid for this to work.
2784#
2785# Note: This will pass any form of authentication but
2786# only Basic auth will work through a proxy unless the
2787# connection-auth options are also used.
2788#
2789# login=PASS Send login details received from client to this peer.
2790# Authentication is not required by this option.
2791#
2792# If there are no client-provided authentication headers
2793# to pass on, but username and password are available
2794# from an external ACL user= and password= result tags
2795# they may be sent instead.
2796#
2797# Note: To combine this with proxy_auth both proxies must
2798# share the same user database as HTTP only allows for
2799# a single login (one for proxy, one for origin server).
2800# Also be warned this will expose your users proxy
2801# password to the peer. USE WITH CAUTION
2802#
2803# login=*:password
2804# Send the username to the upstream cache, but with a
2805# fixed password. This is meant to be used when the peer
2806# is in another administrative domain, but it is still
2807# needed to identify each user.
2808# The star can optionally be followed by some extra
2809# information which is added to the username. This can
2810# be used to identify this proxy to the peer, similar to
2811# the login=username:password option above.
2812#
2813# login=NEGOTIATE
2814# If this is a personal/workgroup proxy and your parent
2815# requires a secure proxy authentication.
2816# The first principal from the default keytab or defined by
2817# the environment variable KRB5_KTNAME will be used.
2818#
2819# WARNING: The connection may transmit requests from multiple
2820# clients. Negotiate often assumes end-to-end authentication
2821# and a single-client. Which is not strictly true here.
2822#
2823# login=NEGOTIATE:principal_name
2824# If this is a personal/workgroup proxy and your parent
2825# requires a secure proxy authentication.
2826# The principal principal_name from the default keytab or
2827# defined by the environment variable KRB5_KTNAME will be
2828# used.
2829#
2830# WARNING: The connection may transmit requests from multiple
2831# clients. Negotiate often assumes end-to-end authentication
2832# and a single-client. Which is not strictly true here.
2833#
2834# connection-auth=on|off
2835# Tell Squid that this peer does or not support Microsoft
2836# connection oriented authentication, and any such
2837# challenges received from there should be ignored.
2838# Default is auto to automatically determine the status
2839# of the peer.
2840#
2841#
2842# ==== SSL / HTTPS / TLS OPTIONS ====
2843#
2844# ssl Encrypt connections to this peer with SSL/TLS.
2845#
2846# sslcert=/path/to/ssl/certificate
2847# A client SSL certificate to use when connecting to
2848# this peer.
2849#
2850# sslkey=/path/to/ssl/key
2851# The private SSL key corresponding to sslcert above.
2852# If 'sslkey' is not specified 'sslcert' is assumed to
2853# reference a combined file containing both the
2854# certificate and the key.
2855#
2856# sslversion=1|2|3|4|5|6
2857# The SSL version to use when connecting to this peer
2858# 1 = automatic (default)
2859# 2 = SSL v2 only
2860# 3 = SSL v3 only
2861# 4 = TLS v1.0 only
2862# 5 = TLS v1.1 only
2863# 6 = TLS v1.2 only
2864#
2865# sslcipher=... The list of valid SSL ciphers to use when connecting
2866# to this peer.
2867#
2868# ssloptions=... Specify various SSL implementation options:
2869#
2870# NO_SSLv2 Disallow the use of SSLv2
2871# NO_SSLv3 Disallow the use of SSLv3
2872# NO_TLSv1 Disallow the use of TLSv1.0
2873# NO_TLSv1_1 Disallow the use of TLSv1.1
2874# NO_TLSv1_2 Disallow the use of TLSv1.2
2875# SINGLE_DH_USE
2876# Always create a new key when using
2877# temporary/ephemeral DH key exchanges
2878# ALL Enable various bug workarounds
2879# suggested as "harmless" by OpenSSL
2880# Be warned that this reduces SSL/TLS
2881# strength to some attacks.
2882#
2883# See the OpenSSL SSL_CTX_set_options documentation for a
2884# more complete list.
2885#
2886# sslcafile=... A file containing additional CA certificates to use
2887# when verifying the peer certificate.
2888#
2889# sslcapath=... A directory containing additional CA certificates to
2890# use when verifying the peer certificate.
2891#
2892# sslcrlfile=... A certificate revocation list file to use when
2893# verifying the peer certificate.
2894#
2895# sslflags=... Specify various flags modifying the SSL implementation:
2896#
2897# DONT_VERIFY_PEER
2898# Accept certificates even if they fail to
2899# verify.
2900# NO_DEFAULT_CA
2901# Don't use the default CA list built in
2902# to OpenSSL.
2903# DONT_VERIFY_DOMAIN
2904# Don't verify the peer certificate
2905# matches the server name
2906#
2907# ssldomain= The peer name as advertised in it's certificate.
2908# Used for verifying the correctness of the received peer
2909# certificate. If not specified the peer hostname will be
2910# used.
2911#
2912# front-end-https
2913# Enable the "Front-End-Https: On" header needed when
2914# using Squid as a SSL frontend in front of Microsoft OWA.
2915# See MS KB document Q307347 for details on this header.
2916# If set to auto the header will only be added if the
2917# request is forwarded as a https:// URL.
2918#
2919#
2920# ==== GENERAL OPTIONS ====
2921#
2922# connect-timeout=N
2923# A peer-specific connect timeout.
2924# Also see the peer_connect_timeout directive.
2925#
2926# connect-fail-limit=N
2927# How many times connecting to a peer must fail before
2928# it is marked as down. Standby connection failures
2929# count towards this limit. Default is 10.
2930#
2931# allow-miss Disable Squid's use of only-if-cached when forwarding
2932# requests to siblings. This is primarily useful when
2933# icp_hit_stale is used by the sibling. Excessive use
2934# of this option may result in forwarding loops. One way
2935# to prevent peering loops when using this option, is to
2936# deny cache peer usage on requests from a peer:
2937# acl fromPeer ...
2938# cache_peer_access peerName deny fromPeer
2939#
2940# max-conn=N Limit the number of concurrent connections the Squid
2941# may open to this peer, including already opened idle
2942# and standby connections. There is no peer-specific
2943# connection limit by default.
2944#
2945# A peer exceeding the limit is not used for new
2946# requests unless a standby connection is available.
2947#
2948# max-conn currently works poorly with idle persistent
2949# connections: When a peer reaches its max-conn limit,
2950# and there are idle persistent connections to the peer,
2951# the peer may not be selected because the limiting code
2952# does not know whether Squid can reuse those idle
2953# connections.
2954#
2955# standby=N Maintain a pool of N "hot standby" connections to an
2956# UP peer, available for requests when no idle
2957# persistent connection is available (or safe) to use.
2958# By default and with zero N, no such pool is maintained.
2959# N must not exceed the max-conn limit (if any).
2960#
2961# At start or after reconfiguration, Squid opens new TCP
2962# standby connections until there are N connections
2963# available and then replenishes the standby pool as
2964# opened connections are used up for requests. A used
2965# connection never goes back to the standby pool, but
2966# may go to the regular idle persistent connection pool
2967# shared by all peers and origin servers.
2968#
2969# Squid never opens multiple new standby connections
2970# concurrently. This one-at-a-time approach minimizes
2971# flooding-like effect on peers. Furthermore, just a few
2972# standby connections should be sufficient in most cases
2973# to supply most new requests with a ready-to-use
2974# connection.
2975#
2976# Standby connections obey server_idle_pconn_timeout.
2977# For the feature to work as intended, the peer must be
2978# configured to accept and keep them open longer than
2979# the idle timeout at the connecting Squid, to minimize
2980# race conditions typical to idle used persistent
2981# connections. Default request_timeout and
2982# server_idle_pconn_timeout values ensure such a
2983# configuration.
2984#
2985# name=xxx Unique name for the peer.
2986# Required if you have multiple peers on the same host
2987# but different ports.
2988# This name can be used in cache_peer_access and similar
2989# directives to identify the peer.
2990# Can be used by outgoing access controls through the
2991# peername ACL type.
2992#
2993# no-tproxy Do not use the client-spoof TPROXY support when forwarding
2994# requests to this peer. Use normal address selection instead.
2995# This overrides the spoof_client_ip ACL.
2996#
2997# proxy-only objects fetched from the peer will not be stored locally.
2998#
2999#Default:
3000# none
3001
3002# TAG: cache_peer_domain
3003# Use to limit the domains for which a neighbor cache will be
3004# queried.
3005#
3006# Usage:
3007# cache_peer_domain cache-host domain [domain ...]
3008# cache_peer_domain cache-host !domain
3009#
3010# For example, specifying
3011#
3012# cache_peer_domain parent.foo.net .edu
3013#
3014# has the effect such that UDP query packets are sent to
3015# 'bigserver' only when the requested object exists on a
3016# server in the .edu domain. Prefixing the domainname
3017# with '!' means the cache will be queried for objects
3018# NOT in that domain.
3019#
3020# NOTE: * Any number of domains may be given for a cache-host,
3021# either on the same or separate lines.
3022# * When multiple domains are given for a particular
3023# cache-host, the first matched domain is applied.
3024# * Cache hosts with no domain restrictions are queried
3025# for all requests.
3026# * There are no defaults.
3027# * There is also a 'cache_peer_access' tag in the ACL
3028# section.
3029#Default:
3030# none
3031
3032# TAG: cache_peer_access
3033# Restricts usage of cache_peer proxies.
3034#
3035# Usage:
3036# cache_peer_access peer-name allow|deny [!]aclname ...
3037#
3038# For the required peer-name parameter, use either the value of the
3039# cache_peer name=value parameter or, if name=value is missing, the
3040# cache_peer hostname parameter.
3041#
3042# This directive narrows down the selection of peering candidates, but
3043# does not determine the order in which the selected candidates are
3044# contacted. That order is determined by the peer selection algorithms
3045# (see PEER SELECTION sections in the cache_peer documentation).
3046#
3047# If a deny rule matches, the corresponding peer will not be contacted
3048# for the current transaction -- Squid will not send ICP queries and
3049# will not forward HTTP requests to that peer. An allow match leaves
3050# the corresponding peer in the selection. The first match for a given
3051# peer wins for that peer.
3052#
3053# The relative order of cache_peer_access directives for the same peer
3054# matters. The relative order of any two cache_peer_access directives
3055# for different peers does not matter. To ease interpretation, it is a
3056# good idea to group cache_peer_access directives for the same peer
3057# together.
3058#
3059# A single cache_peer_access directive may be evaluated multiple times
3060# for a given transaction because individual peer selection algorithms
3061# may check it independently from each other. These redundant checks
3062# may be optimized away in future Squid versions.
3063#
3064# This clause only supports fast acl types.
3065# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
3066#Default:
3067# No peer usage restrictions.
3068
3069# TAG: neighbor_type_domain
3070# Modify the cache_peer neighbor type when passing requests
3071# about specific domains to the peer.
3072#
3073# Usage:
3074# neighbor_type_domain neighbor parent|sibling domain domain ...
3075#
3076# For example:
3077# cache_peer foo.example.com parent 3128 3130
3078# neighbor_type_domain foo.example.com sibling .au .de
3079#
3080# The above configuration treats all requests to foo.example.com as a
3081# parent proxy unless the request is for a .au or .de ccTLD domain name.
3082#Default:
3083# The peer type from cache_peer directive is used for all requests to that peer.
3084
3085# TAG: dead_peer_timeout (seconds)
3086# This controls how long Squid waits to declare a peer cache
3087# as "dead." If there are no ICP replies received in this
3088# amount of time, Squid will declare the peer dead and not
3089# expect to receive any further ICP replies. However, it
3090# continues to send ICP queries, and will mark the peer as
3091# alive upon receipt of the first subsequent ICP reply.
3092#
3093# This timeout also affects when Squid expects to receive ICP
3094# replies from peers. If more than 'dead_peer' seconds have
3095# passed since the last ICP reply was received, Squid will not
3096# expect to receive an ICP reply on the next query. Thus, if
3097# your time between requests is greater than this timeout, you
3098# will see a lot of requests sent DIRECT to origin servers
3099# instead of to your parents.
3100#Default:
3101# dead_peer_timeout 10 seconds
3102
3103# TAG: forward_max_tries
3104# Controls how many different forward paths Squid will try
3105# before giving up. See also forward_timeout.
3106#
3107# NOTE: connect_retries (default: none) can make each of these
3108# possible forwarding paths be tried multiple times.
3109#Default:
3110# forward_max_tries 25
3111
3112# MEMORY CACHE OPTIONS
3113# -----------------------------------------------------------------------------
3114
3115# TAG: cache_mem (bytes)
3116# NOTE: THIS PARAMETER DOES NOT SPECIFY THE MAXIMUM PROCESS SIZE.
3117# IT ONLY PLACES A LIMIT ON HOW MUCH ADDITIONAL MEMORY SQUID WILL
3118# USE AS A MEMORY CACHE OF OBJECTS. SQUID USES MEMORY FOR OTHER
3119# THINGS AS WELL. SEE THE SQUID FAQ SECTION 8 FOR DETAILS.
3120#
3121# 'cache_mem' specifies the ideal amount of memory to be used
3122# for:
3123# * In-Transit objects
3124# * Hot Objects
3125# * Negative-Cached objects
3126#
3127# Data for these objects are stored in 4 KB blocks. This
3128# parameter specifies the ideal upper limit on the total size of
3129# 4 KB blocks allocated. In-Transit objects take the highest
3130# priority.
3131#
3132# In-transit objects have priority over the others. When
3133# additional space is needed for incoming data, negative-cached
3134# and hot objects will be released. In other words, the
3135# negative-cached and hot objects will fill up any unused space
3136# not needed for in-transit objects.
3137#
3138# If circumstances require, this limit will be exceeded.
3139# Specifically, if your incoming request rate requires more than
3140# 'cache_mem' of memory to hold in-transit objects, Squid will
3141# exceed this limit to satisfy the new requests. When the load
3142# decreases, blocks will be freed until the high-water mark is
3143# reached. Thereafter, blocks will be used to store hot
3144# objects.
3145#
3146# If shared memory caching is enabled, Squid does not use the shared
3147# cache space for in-transit objects, but they still consume as much
3148# local memory as they need. For more details about the shared memory
3149# cache, see memory_cache_shared.
3150#Default:
3151# cache_mem 256 MB
3152
3153# TAG: maximum_object_size_in_memory (bytes)
3154# Objects greater than this size will not be attempted to kept in
3155# the memory cache. This should be set high enough to keep objects
3156# accessed frequently in memory to improve performance whilst low
3157# enough to keep larger objects from hoarding cache_mem.
3158#Default:
3159# maximum_object_size_in_memory 512 KB
3160
3161# TAG: memory_cache_shared on|off
3162# Controls whether the memory cache is shared among SMP workers.
3163#
3164# The shared memory cache is meant to occupy cache_mem bytes and replace
3165# the non-shared memory cache, although some entities may still be
3166# cached locally by workers for now (e.g., internal and in-transit
3167# objects may be served from a local memory cache even if shared memory
3168# caching is enabled).
3169#
3170# By default, the memory cache is shared if and only if all of the
3171# following conditions are satisfied: Squid runs in SMP mode with
3172# multiple workers, cache_mem is positive, and Squid environment
3173# supports required IPC primitives (e.g., POSIX shared memory segments
3174# and GCC-style atomic operations).
3175#
3176# To avoid blocking locks, shared memory uses opportunistic algorithms
3177# that do not guarantee that every cachable entity that could have been
3178# shared among SMP workers will actually be shared.
3179#
3180# Currently, entities exceeding 32KB in size cannot be shared.
3181#Default:
3182# "on" where supported if doing memory caching with multiple SMP workers.
3183
3184# TAG: memory_cache_mode
3185# Controls which objects to keep in the memory cache (cache_mem)
3186#
3187# always Keep most recently fetched objects in memory (default)
3188#
3189# disk Only disk cache hits are kept in memory, which means
3190# an object must first be cached on disk and then hit
3191# a second time before cached in memory.
3192#
3193# network Only objects fetched from network is kept in memory
3194#Default:
3195# Keep the most recently fetched objects in memory
3196
3197# TAG: memory_replacement_policy
3198# The memory replacement policy parameter determines which
3199# objects are purged from memory when memory space is needed.
3200#
3201# See cache_replacement_policy for details on algorithms.
3202#Default:
3203# memory_replacement_policy lru
3204
3205# DISK CACHE OPTIONS
3206# -----------------------------------------------------------------------------
3207
3208# TAG: cache_replacement_policy
3209# The cache replacement policy parameter determines which
3210# objects are evicted (replaced) when disk space is needed.
3211#
3212# lru : Squid's original list based LRU policy
3213# heap GDSF : Greedy-Dual Size Frequency
3214# heap LFUDA: Least Frequently Used with Dynamic Aging
3215# heap LRU : LRU policy implemented using a heap
3216#
3217# Applies to any cache_dir lines listed below this directive.
3218#
3219# The LRU policies keeps recently referenced objects.
3220#
3221# The heap GDSF policy optimizes object hit rate by keeping smaller
3222# popular objects in cache so it has a better chance of getting a
3223# hit. It achieves a lower byte hit rate than LFUDA though since
3224# it evicts larger (possibly popular) objects.
3225#
3226# The heap LFUDA policy keeps popular objects in cache regardless of
3227# their size and thus optimizes byte hit rate at the expense of
3228# hit rate since one large, popular object will prevent many
3229# smaller, slightly less popular objects from being cached.
3230#
3231# Both policies utilize a dynamic aging mechanism that prevents
3232# cache pollution that can otherwise occur with frequency-based
3233# replacement policies.
3234#
3235# NOTE: if using the LFUDA replacement policy you should increase
3236# the value of maximum_object_size above its default of 4 MB to
3237# to maximize the potential byte hit rate improvement of LFUDA.
3238#
3239# For more information about the GDSF and LFUDA cache replacement
3240# policies see http://www.hpl.hp.com/techreports/1999/HPL-1999-69.html
3241# and http://fog.hpl.external.hp.com/techreports/98/HPL-98-173.html.
3242#Default:
3243# cache_replacement_policy lru
3244
3245# TAG: minimum_object_size (bytes)
3246# Objects smaller than this size will NOT be saved on disk. The
3247# value is specified in bytes, and the default is 0 KB, which
3248# means all responses can be stored.
3249#Default:
3250# no limit
3251
3252# TAG: maximum_object_size (bytes)
3253# Set the default value for max-size parameter on any cache_dir.
3254# The value is specified in bytes, and the default is 4 MB.
3255#
3256# If you wish to get a high BYTES hit ratio, you should probably
3257# increase this (one 32 MB object hit counts for 3200 10KB
3258# hits).
3259#
3260# If you wish to increase hit ratio more than you want to
3261# save bandwidth you should leave this low.
3262#
3263# NOTE: if using the LFUDA replacement policy you should increase
3264# this value to maximize the byte hit rate improvement of LFUDA!
3265# See cache_replacement_policy for a discussion of this policy.
3266#Default:
3267# maximum_object_size 4 MB
3268
3269# TAG: cache_dir
3270# Format:
3271# cache_dir Type Directory-Name Fs-specific-data [options]
3272#
3273# You can specify multiple cache_dir lines to spread the
3274# cache among different disk partitions.
3275#
3276# Type specifies the kind of storage system to use. Only "ufs"
3277# is built by default. To enable any of the other storage systems
3278# see the --enable-storeio configure option.
3279#
3280# 'Directory' is a top-level directory where cache swap
3281# files will be stored. If you want to use an entire disk
3282# for caching, this can be the mount-point directory.
3283# The directory must exist and be writable by the Squid
3284# process. Squid will NOT create this directory for you.
3285#
3286# In SMP configurations, cache_dir must not precede the workers option
3287# and should use configuration macros or conditionals to give each
3288# worker interested in disk caching a dedicated cache directory.
3289#
3290#
3291# ==== The ufs store type ====
3292#
3293# "ufs" is the old well-known Squid storage format that has always
3294# been there.
3295#
3296# Usage:
3297# cache_dir ufs Directory-Name Mbytes L1 L2 [options]
3298#
3299# 'Mbytes' is the amount of disk space (MB) to use under this
3300# directory. The default is 100 MB. Change this to suit your
3301# configuration. Do NOT put the size of your disk drive here.
3302# Instead, if you want Squid to use the entire disk drive,
3303# subtract 20% and use that value.
3304#
3305# 'L1' is the number of first-level subdirectories which
3306# will be created under the 'Directory'. The default is 16.
3307#
3308# 'L2' is the number of second-level subdirectories which
3309# will be created under each first-level directory. The default
3310# is 256.
3311#
3312#
3313# ==== The aufs store type ====
3314#
3315# "aufs" uses the same storage format as "ufs", utilizing
3316# POSIX-threads to avoid blocking the main Squid process on
3317# disk-I/O. This was formerly known in Squid as async-io.
3318#
3319# Usage:
3320# cache_dir aufs Directory-Name Mbytes L1 L2 [options]
3321#
3322# see argument descriptions under ufs above
3323#
3324#
3325# ==== The diskd store type ====
3326#
3327# "diskd" uses the same storage format as "ufs", utilizing a
3328# separate process to avoid blocking the main Squid process on
3329# disk-I/O.
3330#
3331# Usage:
3332# cache_dir diskd Directory-Name Mbytes L1 L2 [options] [Q1=n] [Q2=n]
3333#
3334# see argument descriptions under ufs above
3335#
3336# Q1 specifies the number of unacknowledged I/O requests when Squid
3337# stops opening new files. If this many messages are in the queues,
3338# Squid won't open new files. Default is 64
3339#
3340# Q2 specifies the number of unacknowledged messages when Squid
3341# starts blocking. If this many messages are in the queues,
3342# Squid blocks until it receives some replies. Default is 72
3343#
3344# When Q1 < Q2 (the default), the cache directory is optimized
3345# for lower response time at the expense of a decrease in hit
3346# ratio. If Q1 > Q2, the cache directory is optimized for
3347# higher hit ratio at the expense of an increase in response
3348# time.
3349#
3350#
3351# ==== The rock store type ====
3352#
3353# Usage:
3354# cache_dir rock Directory-Name Mbytes [options]
3355#
3356# The Rock Store type is a database-style storage. All cached
3357# entries are stored in a "database" file, using fixed-size slots.
3358# A single entry occupies one or more slots.
3359#
3360# If possible, Squid using Rock Store creates a dedicated kid
3361# process called "disker" to avoid blocking Squid worker(s) on disk
3362# I/O. One disker kid is created for each rock cache_dir. Diskers
3363# are created only when Squid, running in daemon mode, has support
3364# for the IpcIo disk I/O module.
3365#
3366# swap-timeout=msec: Squid will not start writing a miss to or
3367# reading a hit from disk if it estimates that the swap operation
3368# will take more than the specified number of milliseconds. By
3369# default and when set to zero, disables the disk I/O time limit
3370# enforcement. Ignored when using blocking I/O module because
3371# blocking synchronous I/O does not allow Squid to estimate the
3372# expected swap wait time.
3373#
3374# max-swap-rate=swaps/sec: Artificially limits disk access using
3375# the specified I/O rate limit. Swap out requests that
3376# would cause the average I/O rate to exceed the limit are
3377# delayed. Individual swap in requests (i.e., hits or reads) are
3378# not delayed, but they do contribute to measured swap rate and
3379# since they are placed in the same FIFO queue as swap out
3380# requests, they may wait longer if max-swap-rate is smaller.
3381# This is necessary on file systems that buffer "too
3382# many" writes and then start blocking Squid and other processes
3383# while committing those writes to disk. Usually used together
3384# with swap-timeout to avoid excessive delays and queue overflows
3385# when disk demand exceeds available disk "bandwidth". By default
3386# and when set to zero, disables the disk I/O rate limit
3387# enforcement. Currently supported by IpcIo module only.
3388#
3389# slot-size=bytes: The size of a database "record" used for
3390# storing cached responses. A cached response occupies at least
3391# one slot and all database I/O is done using individual slots so
3392# increasing this parameter leads to more disk space waste while
3393# decreasing it leads to more disk I/O overheads. Should be a
3394# multiple of your operating system I/O page size. Defaults to
3395# 16KBytes. A housekeeping header is stored with each slot and
3396# smaller slot-sizes will be rejected. The header is smaller than
3397# 100 bytes.
3398#
3399#
3400# ==== COMMON OPTIONS ====
3401#
3402# no-store no new objects should be stored to this cache_dir.
3403#
3404# min-size=n the minimum object size in bytes this cache_dir
3405# will accept. It's used to restrict a cache_dir
3406# to only store large objects (e.g. AUFS) while
3407# other stores are optimized for smaller objects
3408# (e.g. Rock).
3409# Defaults to 0.
3410#
3411# max-size=n the maximum object size in bytes this cache_dir
3412# supports.
3413# The value in maximum_object_size directive sets
3414# the default unless more specific details are
3415# available (ie a small store capacity).
3416#
3417# Note: To make optimal use of the max-size limits you should order
3418# the cache_dir lines with the smallest max-size value first.
3419#
3420#Default:
3421# No disk cache. Store cache ojects only in memory.
3422#
3423
3424# Uncomment and adjust the following to add a disk cache directory.
3425#cache_dir ufs /var/cache/squid 100 16 256
3426
3427# TAG: store_dir_select_algorithm
3428# How Squid selects which cache_dir to use when the response
3429# object will fit into more than one.
3430#
3431# Regardless of which algorithm is used the cache_dir min-size
3432# and max-size parameters are obeyed. As such they can affect
3433# the selection algorithm by limiting the set of considered
3434# cache_dir.
3435#
3436# Algorithms:
3437#
3438# least-load
3439#
3440# This algorithm is suited to caches with similar cache_dir
3441# sizes and disk speeds.
3442#
3443# The disk with the least I/O pending is selected.
3444# When there are multiple disks with the same I/O load ranking
3445# the cache_dir with most available capacity is selected.
3446#
3447# When a mix of cache_dir sizes are configured the faster disks
3448# have a naturally lower I/O loading and larger disks have more
3449# capacity. So space used to store objects and data throughput
3450# may be very unbalanced towards larger disks.
3451#
3452#
3453# round-robin
3454#
3455# This algorithm is suited to caches with unequal cache_dir
3456# disk sizes.
3457#
3458# Each cache_dir is selected in a rotation. The next suitable
3459# cache_dir is used.
3460#
3461# Available cache_dir capacity is only considered in relation
3462# to whether the object will fit and meets the min-size and
3463# max-size parameters.
3464#
3465# Disk I/O loading is only considered to prevent overload on slow
3466# disks. This algorithm does not spread objects by size, so any
3467# I/O loading per-disk may appear very unbalanced and volatile.
3468#
3469# If several cache_dirs use similar min-size, max-size, or other
3470# limits to to reject certain responses, then do not group such
3471# cache_dir lines together, to avoid round-robin selection bias
3472# towards the first cache_dir after the group. Instead, interleave
3473# cache_dir lines from different groups. For example:
3474#
3475# store_dir_select_algorithm round-robin
3476# cache_dir rock /hdd1 ... min-size=100000
3477# cache_dir rock /ssd1 ... max-size=99999
3478# cache_dir rock /hdd2 ... min-size=100000
3479# cache_dir rock /ssd2 ... max-size=99999
3480# cache_dir rock /hdd3 ... min-size=100000
3481# cache_dir rock /ssd3 ... max-size=99999
3482#Default:
3483# store_dir_select_algorithm least-load
3484
3485# TAG: max_open_disk_fds
3486# To avoid having disk as the I/O bottleneck Squid can optionally
3487# bypass the on-disk cache if more than this amount of disk file
3488# descriptors are open.
3489#
3490# A value of 0 indicates no limit.
3491#Default:
3492# no limit
3493
3494# TAG: cache_swap_low (percent, 0-100)
3495# The low-water mark for AUFS/UFS/diskd cache object eviction by
3496# the cache_replacement_policy algorithm.
3497#
3498# Removal begins when the swap (disk) usage of a cache_dir is
3499# above this low-water mark and attempts to maintain utilization
3500# near the low-water mark.
3501#
3502# As swap utilization increases towards the high-water mark set
3503# by cache_swap_high object eviction becomes more agressive.
3504#
3505# The value difference in percentages between low- and high-water
3506# marks represent an eviction rate of 300 objects per second and
3507# the rate continues to scale in agressiveness by multiples of
3508# this above the high-water mark.
3509#
3510# Defaults are 90% and 95%. If you have a large cache, 5% could be
3511# hundreds of MB. If this is the case you may wish to set these
3512# numbers closer together.
3513#
3514# See also cache_swap_high and cache_replacement_policy
3515#Default:
3516# cache_swap_low 90
3517
3518# TAG: cache_swap_high (percent, 0-100)
3519# The high-water mark for AUFS/UFS/diskd cache object eviction by
3520# the cache_replacement_policy algorithm.
3521#
3522# Removal begins when the swap (disk) usage of a cache_dir is
3523# above the low-water mark set by cache_swap_low and attempts to
3524# maintain utilization near the low-water mark.
3525#
3526# As swap utilization increases towards this high-water mark object
3527# eviction becomes more agressive.
3528#
3529# The value difference in percentages between low- and high-water
3530# marks represent an eviction rate of 300 objects per second and
3531# the rate continues to scale in agressiveness by multiples of
3532# this above the high-water mark.
3533#
3534# Defaults are 90% and 95%. If you have a large cache, 5% could be
3535# hundreds of MB. If this is the case you may wish to set these
3536# numbers closer together.
3537#
3538# See also cache_swap_low and cache_replacement_policy
3539#Default:
3540# cache_swap_high 95
3541
3542# LOGFILE OPTIONS
3543# -----------------------------------------------------------------------------
3544
3545# TAG: logformat
3546# Usage:
3547#
3548# logformat <name> <format specification>
3549#
3550# Defines an access log format.
3551#
3552# The <format specification> is a string with embedded % format codes
3553#
3554# % format codes all follow the same basic structure where all but
3555# the formatcode is optional. Output strings are automatically escaped
3556# as required according to their context and the output format
3557# modifiers are usually not needed, but can be specified if an explicit
3558# output format is desired.
3559#
3560# % ["|[|'|#] [-] [[0]width] [{argument}] formatcode
3561#
3562# " output in quoted string format
3563# [ output in squid text log format as used by log_mime_hdrs
3564# # output in URL quoted format
3565# ' output as-is
3566#
3567# - left aligned
3568#
3569# width minimum and/or maximum field width:
3570# [width_min][.width_max]
3571# When minimum starts with 0, the field is zero-padded.
3572# String values exceeding maximum width are truncated.
3573#
3574# {arg} argument such as header name etc
3575#
3576# Format codes:
3577#
3578# % a literal % character
3579# sn Unique sequence number per log line entry
3580# err_code The ID of an error response served by Squid or
3581# a similar internal error identifier.
3582# err_detail Additional err_code-dependent error information.
3583# note The annotation specified by the argument. Also
3584# logs the adaptation meta headers set by the
3585# adaptation_meta configuration parameter.
3586# If no argument given all annotations logged.
3587# The argument may include a separator to use with
3588# annotation values:
3589# name[:separator]
3590# By default, multiple note values are separated with ","
3591# and multiple notes are separated with "\r\n".
3592# When logging named notes with %{name}note, the
3593# explicitly configured separator is used between note
3594# values. When logging all notes with %note, the
3595# explicitly configured separator is used between
3596# individual notes. There is currently no way to
3597# specify both value and notes separators when logging
3598# all notes with %note.
3599#
3600# Connection related format codes:
3601#
3602# >a Client source IP address
3603# >A Client FQDN
3604# >p Client source port
3605# >eui Client source EUI (MAC address, EUI-48 or EUI-64 identifier)
3606# >la Local IP address the client connected to
3607# >lp Local port number the client connected to
3608# >qos Client connection TOS/DSCP value set by Squid
3609# >nfmark Client connection netfilter mark set by Squid
3610#
3611# la Local listening IP address the client connection was connected to.
3612# lp Local listening port number the client connection was connected to.
3613#
3614# <a Server IP address of the last server or peer connection
3615# <A Server FQDN or peer name
3616# <p Server port number of the last server or peer connection
3617# <la Local IP address of the last server or peer connection
3618# <lp Local port number of the last server or peer connection
3619# <qos Server connection TOS/DSCP value set by Squid
3620# <nfmark Server connection netfilter mark set by Squid
3621#
3622# Time related format codes:
3623#
3624# ts Seconds since epoch
3625# tu subsecond time (milliseconds)
3626# tl Local time. Optional strftime format argument
3627# default %d/%b/%Y:%H:%M:%S %z
3628# tg GMT time. Optional strftime format argument
3629# default %d/%b/%Y:%H:%M:%S %z
3630# tr Response time (milliseconds)
3631# dt Total time spent making DNS lookups (milliseconds)
3632# tS Approximate master transaction start time in
3633# <full seconds since epoch>.<fractional seconds> format.
3634# Currently, Squid considers the master transaction
3635# started when a complete HTTP request header initiating
3636# the transaction is received from the client. This is
3637# the same value that Squid uses to calculate transaction
3638# response time when logging %tr to access.log. Currently,
3639# Squid uses millisecond resolution for %tS values,
3640# similar to the default access.log "current time" field
3641# (%ts.%03tu).
3642#
3643# Access Control related format codes:
3644#
3645# et Tag returned by external acl
3646# ea Log string returned by external acl
3647# un User name (any available)
3648# ul User name from authentication
3649# ue User name from external acl helper
3650# ui User name from ident
3651# un A user name. Expands to the first available name
3652# from the following list of information sources:
3653# - authenticated user name, like %ul
3654# - user name supplied by an external ACL, like %ue
3655# - SSL client name, like %us
3656# - ident user name, like %ui
3657# credentials Client credentials. The exact meaning depends on
3658# the authentication scheme: For Basic authentication,
3659# it is the password; for Digest, the realm sent by the
3660# client; for NTLM and Negotiate, the client challenge
3661# or client credentials prefixed with "YR " or "KK ".
3662#
3663# HTTP related format codes:
3664#
3665# REQUEST
3666#
3667# [http::]rm Request method (GET/POST etc)
3668# [http::]>rm Request method from client
3669# [http::]<rm Request method sent to server or peer
3670# [http::]ru Request URL from client (historic, filtered for logging)
3671# [http::]>ru Request URL from client
3672# [http::]<ru Request URL sent to server or peer
3673# [http::]>rs Request URL scheme from client
3674# [http::]<rs Request URL scheme sent to server or peer
3675# [http::]>rd Request URL domain from client
3676# [http::]<rd Request URL domain sent to server or peer
3677# [http::]>rP Request URL port from client
3678# [http::]<rP Request URL port sent to server or peer
3679# [http::]rp Request URL path excluding hostname
3680# [http::]>rp Request URL path excluding hostname from client
3681# [http::]<rp Request URL path excluding hostname sent to server or peer
3682# [http::]rv Request protocol version
3683# [http::]>rv Request protocol version from client
3684# [http::]<rv Request protocol version sent to server or peer
3685#
3686# [http::]>h Original received request header.
3687# Usually differs from the request header sent by
3688# Squid, although most fields are often preserved.
3689# Accepts optional header field name/value filter
3690# argument using name[:[separator]element] format.
3691# [http::]>ha Received request header after adaptation and
3692# redirection (pre-cache REQMOD vectoring point).
3693# Usually differs from the request header sent by
3694# Squid, although most fields are often preserved.
3695# Optional header name argument as for >h
3696#
3697#
3698# RESPONSE
3699#
3700# [http::]<Hs HTTP status code received from the next hop
3701# [http::]>Hs HTTP status code sent to the client
3702#
3703# [http::]<h Reply header. Optional header name argument
3704# as for >h
3705#
3706# [http::]mt MIME content type
3707#
3708#
3709# SIZE COUNTERS
3710#
3711# [http::]st Total size of request + reply traffic with client
3712# [http::]>st Total size of request received from client.
3713# Excluding chunked encoding bytes.
3714# [http::]<st Total size of reply sent to client (after adaptation)
3715#
3716# [http::]>sh Size of request headers received from client
3717# [http::]<sh Size of reply headers sent to client (after adaptation)
3718#
3719# [http::]<sH Reply high offset sent
3720# [http::]<sS Upstream object size
3721#
3722# [http::]<bs Number of HTTP-equivalent message body bytes
3723# received from the next hop, excluding chunked
3724# transfer encoding and control messages.
3725# Generated FTP/Gopher listings are treated as
3726# received bodies.
3727#
3728#
3729# TIMING
3730#
3731# [http::]<pt Peer response time in milliseconds. The timer starts
3732# when the last request byte is sent to the next hop
3733# and stops when the last response byte is received.
3734# [http::]<tt Total time in milliseconds. The timer
3735# starts with the first connect request (or write I/O)
3736# sent to the first selected peer. The timer stops
3737# with the last I/O with the last peer.
3738#
3739# Squid handling related format codes:
3740#
3741# Ss Squid request status (TCP_MISS etc)
3742# Sh Squid hierarchy status (DEFAULT_PARENT etc)
3743#
3744# SSL-related format codes:
3745#
3746# ssl::bump_mode SslBump decision for the transaction:
3747#
3748# For CONNECT requests that initiated bumping of
3749# a connection and for any request received on
3750# an already bumped connection, Squid logs the
3751# corresponding SslBump mode ("server-first" or
3752# "client-first"). See the ssl_bump option for
3753# more information about these modes.
3754#
3755# A "none" token is logged for requests that
3756# triggered "ssl_bump" ACL evaluation matching
3757# either a "none" rule or no rules at all.
3758#
3759# In all other cases, a single dash ("-") is
3760# logged.
3761#
3762# ssl::>sni SSL client SNI sent to Squid. Available only
3763# after the peek, stare, or splice SSL bumping
3764# actions.
3765#
3766# If ICAP is enabled, the following code becomes available (as
3767# well as ICAP log codes documented with the icap_log option):
3768#
3769# icap::tt Total ICAP processing time for the HTTP
3770# transaction. The timer ticks when ICAP
3771# ACLs are checked and when ICAP
3772# transaction is in progress.
3773#
3774# If adaptation is enabled the following three codes become available:
3775#
3776# adapt::<last_h The header of the last ICAP response or
3777# meta-information from the last eCAP
3778# transaction related to the HTTP transaction.
3779# Like <h, accepts an optional header name
3780# argument.
3781#
3782# adapt::sum_trs Summed adaptation transaction response
3783# times recorded as a comma-separated list in
3784# the order of transaction start time. Each time
3785# value is recorded as an integer number,
3786# representing response time of one or more
3787# adaptation (ICAP or eCAP) transaction in
3788# milliseconds. When a failed transaction is
3789# being retried or repeated, its time is not
3790# logged individually but added to the
3791# replacement (next) transaction. See also:
3792# adapt::all_trs.
3793#
3794# adapt::all_trs All adaptation transaction response times.
3795# Same as adaptation_strs but response times of
3796# individual transactions are never added
3797# together. Instead, all transaction response
3798# times are recorded individually.
3799#
3800# You can prefix adapt::*_trs format codes with adaptation
3801# service name in curly braces to record response time(s) specific
3802# to that service. For example: %{my_service}adapt::sum_trs
3803#
3804# If SSL is enabled, the following formating codes become available:
3805#
3806# %ssl::>cert_subject The Subject field of the received client
3807# SSL certificate or a dash ('-') if Squid has
3808# received an invalid/malformed certificate or
3809# no certificate at all. Consider encoding the
3810# logged value because Subject often has spaces.
3811#
3812# %ssl::>cert_issuer The Issuer field of the received client
3813# SSL certificate or a dash ('-') if Squid has
3814# received an invalid/malformed certificate or
3815# no certificate at all. Consider encoding the
3816# logged value because Issuer often has spaces.
3817#
3818# The default formats available (which do not need re-defining) are:
3819#
3820#logformat squid %ts.%03tu %6tr %>a %Ss/%03>Hs %<st %rm %ru %[un %Sh/%<a %mt
3821#logformat common %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st %Ss:%Sh
3822#logformat combined %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st "%{Referer}>h" "%{User-Agent}>h" %Ss:%Sh
3823#logformat referrer %ts.%03tu %>a %{Referer}>h %ru
3824#logformat useragent %>a [%tl] "%{User-Agent}>h"
3825#
3826# NOTE: When the log_mime_hdrs directive is set to ON.
3827# The squid, common and combined formats have a safely encoded copy
3828# of the mime headers appended to each line within a pair of brackets.
3829#
3830# NOTE: The common and combined formats are not quite true to the Apache definition.
3831# The logs from Squid contain an extra status and hierarchy code appended.
3832#
3833#Default:
3834# The format definitions squid, common, combined, referrer, useragent are built in.
3835
3836# TAG: access_log
3837# Configures whether and how Squid logs HTTP and ICP transactions.
3838# If access logging is enabled, a single line is logged for every
3839# matching HTTP or ICP request. The recommended directive formats are:
3840#
3841# access_log <module>:<place> [option ...] [acl acl ...]
3842# access_log none [acl acl ...]
3843#
3844# The following directive format is accepted but may be deprecated:
3845# access_log <module>:<place> [<logformat name> [acl acl ...]]
3846#
3847# In most cases, the first ACL name must not contain the '=' character
3848# and should not be equal to an existing logformat name. You can always
3849# start with an 'all' ACL to work around those restrictions.
3850#
3851# Will log to the specified module:place using the specified format (which
3852# must be defined in a logformat directive) those entries which match
3853# ALL the acl's specified (which must be defined in acl clauses).
3854# If no acl is specified, all requests will be logged to this destination.
3855#
3856# ===== Available options for the recommended directive format =====
3857#
3858# logformat=name Names log line format (either built-in or
3859# defined by a logformat directive). Defaults
3860# to 'squid'.
3861#
3862# buffer-size=64KB Defines approximate buffering limit for log
3863# records (see buffered_logs). Squid should not
3864# keep more than the specified size and, hence,
3865# should flush records before the buffer becomes
3866# full to avoid overflows under normal
3867# conditions (the exact flushing algorithm is
3868# module-dependent though). The on-error option
3869# controls overflow handling.
3870#
3871# on-error=die|drop Defines action on unrecoverable errors. The
3872# 'drop' action ignores (i.e., does not log)
3873# affected log records. The default 'die' action
3874# kills the affected worker. The drop action
3875# support has not been tested for modules other
3876# than tcp.
3877#
3878# ===== Modules Currently available =====
3879#
3880# none Do not log any requests matching these ACL.
3881# Do not specify Place or logformat name.
3882#
3883# stdio Write each log line to disk immediately at the completion of
3884# each request.
3885# Place: the filename and path to be written.
3886#
3887# daemon Very similar to stdio. But instead of writing to disk the log
3888# line is passed to a daemon helper for asychronous handling instead.
3889# Place: varies depending on the daemon.
3890#
3891# log_file_daemon Place: the file name and path to be written.
3892#
3893# syslog To log each request via syslog facility.
3894# Place: The syslog facility and priority level for these entries.
3895# Place Format: facility.priority
3896#
3897# where facility could be any of:
3898# authpriv, daemon, local0 ... local7 or user.
3899#
3900# And priority could be any of:
3901# err, warning, notice, info, debug.
3902#
3903# udp To send each log line as text data to a UDP receiver.
3904# Place: The destination host name or IP and port.
3905# Place Format: //host:port
3906#
3907# tcp To send each log line as text data to a TCP receiver.
3908# Lines may be accumulated before sending (see buffered_logs).
3909# Place: The destination host name or IP and port.
3910# Place Format: //host:port
3911#
3912# Default:
3913# access_log daemon:/var/log/squid/access.log squid
3914#Default:
3915# access_log daemon:/var/log/squid/access.log squid
3916
3917# TAG: icap_log
3918# ICAP log files record ICAP transaction summaries, one line per
3919# transaction.
3920#
3921# The icap_log option format is:
3922# icap_log <filepath> [<logformat name> [acl acl ...]]
3923# icap_log none [acl acl ...]]
3924#
3925# Please see access_log option documentation for details. The two
3926# kinds of logs share the overall configuration approach and many
3927# features.
3928#
3929# ICAP processing of a single HTTP message or transaction may
3930# require multiple ICAP transactions. In such cases, multiple
3931# ICAP transaction log lines will correspond to a single access
3932# log line.
3933#
3934# ICAP log uses logformat codes that make sense for an ICAP
3935# transaction. Header-related codes are applied to the HTTP header
3936# embedded in an ICAP server response, with the following caveats:
3937# For REQMOD, there is no HTTP response header unless the ICAP
3938# server performed request satisfaction. For RESPMOD, the HTTP
3939# request header is the header sent to the ICAP server. For
3940# OPTIONS, there are no HTTP headers.
3941#
3942# The following format codes are also available for ICAP logs:
3943#
3944# icap::<A ICAP server IP address. Similar to <A.
3945#
3946# icap::<service_name ICAP service name from the icap_service
3947# option in Squid configuration file.
3948#
3949# icap::ru ICAP Request-URI. Similar to ru.
3950#
3951# icap::rm ICAP request method (REQMOD, RESPMOD, or
3952# OPTIONS). Similar to existing rm.
3953#
3954# icap::>st Bytes sent to the ICAP server (TCP payload
3955# only; i.e., what Squid writes to the socket).
3956#
3957# icap::<st Bytes received from the ICAP server (TCP
3958# payload only; i.e., what Squid reads from
3959# the socket).
3960#
3961# icap::<bs Number of message body bytes received from the
3962# ICAP server. ICAP message body, if any, usually
3963# includes encapsulated HTTP message headers and
3964# possibly encapsulated HTTP message body. The
3965# HTTP body part is dechunked before its size is
3966# computed.
3967#
3968# icap::tr Transaction response time (in
3969# milliseconds). The timer starts when
3970# the ICAP transaction is created and
3971# stops when the transaction is completed.
3972# Similar to tr.
3973#
3974# icap::tio Transaction I/O time (in milliseconds). The
3975# timer starts when the first ICAP request
3976# byte is scheduled for sending. The timers
3977# stops when the last byte of the ICAP response
3978# is received.
3979#
3980# icap::to Transaction outcome: ICAP_ERR* for all
3981# transaction errors, ICAP_OPT for OPTION
3982# transactions, ICAP_ECHO for 204
3983# responses, ICAP_MOD for message
3984# modification, and ICAP_SAT for request
3985# satisfaction. Similar to Ss.
3986#
3987# icap::Hs ICAP response status code. Similar to Hs.
3988#
3989# icap::>h ICAP request header(s). Similar to >h.
3990#
3991# icap::<h ICAP response header(s). Similar to <h.
3992#
3993# The default ICAP log format, which can be used without an explicit
3994# definition, is called icap_squid:
3995#
3996#logformat icap_squid %ts.%03tu %6icap::tr %>a %icap::to/%03icap::Hs %icap::<size %icap::rm %icap::ru% %un -/%icap::<A -
3997#
3998# See also: logformat, log_icap, and %adapt::<last_h
3999#Default:
4000# none
4001
4002# TAG: logfile_daemon
4003# Specify the path to the logfile-writing daemon. This daemon is
4004# used to write the access and store logs, if configured.
4005#
4006# Squid sends a number of commands to the log daemon:
4007# L<data>\n - logfile data
4008# R\n - rotate file
4009# T\n - truncate file
4010# O\n - reopen file
4011# F\n - flush file
4012# r<n>\n - set rotate count to <n>
4013# b<n>\n - 1 = buffer output, 0 = don't buffer output
4014#
4015# No responses is expected.
4016#Default:
4017# logfile_daemon /usr/lib/squid/log_file_daemon
4018
4019# TAG: stats_collection allow|deny acl acl...
4020# This options allows you to control which requests gets accounted
4021# in performance counters.
4022#
4023# This clause only supports fast acl types.
4024# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4025#Default:
4026# Allow logging for all transactions.
4027
4028# TAG: cache_store_log
4029# Logs the activities of the storage manager. Shows which
4030# objects are ejected from the cache, and which objects are
4031# saved and for how long.
4032# There are not really utilities to analyze this data, so you can safely
4033# disable it (the default).
4034#
4035# Store log uses modular logging outputs. See access_log for the list
4036# of modules supported.
4037#
4038# Example:
4039# cache_store_log stdio:/var/log/squid/store.log
4040# cache_store_log daemon:/var/log/squid/store.log
4041#Default:
4042# none
4043
4044# TAG: cache_swap_state
4045# Location for the cache "swap.state" file. This index file holds
4046# the metadata of objects saved on disk. It is used to rebuild
4047# the cache during startup. Normally this file resides in each
4048# 'cache_dir' directory, but you may specify an alternate
4049# pathname here. Note you must give a full filename, not just
4050# a directory. Since this is the index for the whole object
4051# list you CANNOT periodically rotate it!
4052#
4053# If %s can be used in the file name it will be replaced with a
4054# a representation of the cache_dir name where each / is replaced
4055# with '.'. This is needed to allow adding/removing cache_dir
4056# lines when cache_swap_log is being used.
4057#
4058# If have more than one 'cache_dir', and %s is not used in the name
4059# these swap logs will have names such as:
4060#
4061# cache_swap_log.00
4062# cache_swap_log.01
4063# cache_swap_log.02
4064#
4065# The numbered extension (which is added automatically)
4066# corresponds to the order of the 'cache_dir' lines in this
4067# configuration file. If you change the order of the 'cache_dir'
4068# lines in this file, these index files will NOT correspond to
4069# the correct 'cache_dir' entry (unless you manually rename
4070# them). We recommend you do NOT use this option. It is
4071# better to keep these index files in each 'cache_dir' directory.
4072#Default:
4073# Store the journal inside its cache_dir
4074
4075# TAG: logfile_rotate
4076# Specifies the number of logfile rotations to make when you
4077# type 'squid -k rotate'. The default is 10, which will rotate
4078# with extensions 0 through 9. Setting logfile_rotate to 0 will
4079# disable the file name rotation, but the logfiles are still closed
4080# and re-opened. This will enable you to rename the logfiles
4081# yourself just before sending the rotate signal.
4082#
4083# Note, the 'squid -k rotate' command normally sends a USR1
4084# signal to the running squid process. In certain situations
4085# (e.g. on Linux with Async I/O), USR1 is used for other
4086# purposes, so -k rotate uses another signal. It is best to get
4087# in the habit of using 'squid -k rotate' instead of 'kill -USR1
4088# <pid>'.
4089#
4090# Note, from Squid-3.1 this option is only a default for cache.log,
4091# that log can be rotated separately by using debug_options.
4092#Default:
4093# logfile_rotate 10
4094
4095# TAG: mime_table
4096# Path to Squid's icon configuration file.
4097#
4098# You shouldn't need to change this, but the default file contains
4099# examples and formatting information if you do.
4100#Default:
4101# mime_table /etc/squid/mime.conf
4102
4103# TAG: log_mime_hdrs on|off
4104# The Cache can record both the request and the response MIME
4105# headers for each HTTP transaction. The headers are encoded
4106# safely and will appear as two bracketed fields at the end of
4107# the access log (for either the native or httpd-emulated log
4108# formats). To enable this logging set log_mime_hdrs to 'on'.
4109#Default:
4110# log_mime_hdrs off
4111
4112# TAG: pid_filename
4113# A filename to write the process-id to. To disable, enter "none".
4114#Default:
4115# pid_filename /var/run/squid.pid
4116
4117# TAG: client_netmask
4118# A netmask for client addresses in logfiles and cachemgr output.
4119# Change this to protect the privacy of your cache clients.
4120# A netmask of 255.255.255.0 will log all IP's in that range with
4121# the last digit set to '0'.
4122#Default:
4123# Log full client IP address
4124
4125# TAG: strip_query_terms
4126# By default, Squid strips query terms from requested URLs before
4127# logging. This protects your user's privacy and reduces log size.
4128#
4129# When investigating HIT/MISS or other caching behaviour you
4130# will need to disable this to see the full URL used by Squid.
4131#Default:
4132# strip_query_terms on
4133
4134# TAG: buffered_logs on|off
4135# Whether to write/send access_log records ASAP or accumulate them and
4136# then write/send them in larger chunks. Buffering may improve
4137# performance because it decreases the number of I/Os. However,
4138# buffering increases the delay before log records become available to
4139# the final recipient (e.g., a disk file or logging daemon) and,
4140# hence, increases the risk of log records loss.
4141#
4142# Note that even when buffered_logs are off, Squid may have to buffer
4143# records if it cannot write/send them immediately due to pending I/Os
4144# (e.g., the I/O writing the previous log record) or connectivity loss.
4145#
4146# Currently honored by 'daemon' and 'tcp' access_log modules only.
4147#Default:
4148# buffered_logs off
4149
4150# TAG: netdb_filename
4151# Note: This option is only available if Squid is rebuilt with the
4152# --enable-icmp
4153#
4154# Where Squid stores it's netdb journal.
4155# When enabled this journal preserves netdb state between restarts.
4156#
4157# To disable, enter "none".
4158#Default:
4159# netdb_filename stdio:/var/log/squid/netdb.state
4160
4161# OPTIONS FOR TROUBLESHOOTING
4162# -----------------------------------------------------------------------------
4163
4164# TAG: cache_log
4165# Squid administrative logging file.
4166#
4167# This is where general information about Squid behavior goes. You can
4168# increase the amount of data logged to this file and how often it is
4169# rotated with "debug_options"
4170#Default:
4171# cache_log /var/log/squid/cache.log
4172
4173# TAG: debug_options
4174# Logging options are set as section,level where each source file
4175# is assigned a unique section. Lower levels result in less
4176# output, Full debugging (level 9) can result in a very large
4177# log file, so be careful.
4178#
4179# The magic word "ALL" sets debugging levels for all sections.
4180# The default is to run with "ALL,1" to record important warnings.
4181#
4182# The rotate=N option can be used to keep more or less of these logs
4183# than would otherwise be kept by logfile_rotate.
4184# For most uses a single log should be enough to monitor current
4185# events affecting Squid.
4186#Default:
4187# Log all critical and important messages.
4188
4189# TAG: coredump_dir
4190# By default Squid leaves core files in the directory from where
4191# it was started. If you set 'coredump_dir' to a directory
4192# that exists, Squid will chdir() to that directory at startup
4193# and coredump files will be left there.
4194#
4195#Default:
4196# Use the directory from where Squid was started.
4197#
4198
4199# Leave coredumps in the first cache dir
4200coredump_dir /var/cache/squid
4201
4202# OPTIONS FOR FTP GATEWAYING
4203# -----------------------------------------------------------------------------
4204
4205# TAG: ftp_user
4206# If you want the anonymous login password to be more informative
4207# (and enable the use of picky FTP servers), set this to something
4208# reasonable for your domain, like wwwuser@somewhere.net
4209#
4210# The reason why this is domainless by default is the
4211# request can be made on the behalf of a user in any domain,
4212# depending on how the cache is used.
4213# Some FTP server also validate the email address is valid
4214# (for example perl.com).
4215#Default:
4216# ftp_user Squid@
4217
4218# TAG: ftp_passive
4219# If your firewall does not allow Squid to use passive
4220# connections, turn off this option.
4221#
4222# Use of ftp_epsv_all option requires this to be ON.
4223#Default:
4224# ftp_passive on
4225
4226# TAG: ftp_epsv_all
4227# FTP Protocol extensions permit the use of a special "EPSV ALL" command.
4228#
4229# NATs may be able to put the connection on a "fast path" through the
4230# translator, as the EPRT command will never be used and therefore,
4231# translation of the data portion of the segments will never be needed.
4232#
4233# When a client only expects to do two-way FTP transfers this may be
4234# useful.
4235# If squid finds that it must do a three-way FTP transfer after issuing
4236# an EPSV ALL command, the FTP session will fail.
4237#
4238# If you have any doubts about this option do not use it.
4239# Squid will nicely attempt all other connection methods.
4240#
4241# Requires ftp_passive to be ON (default) for any effect.
4242#Default:
4243# ftp_epsv_all off
4244
4245# TAG: ftp_epsv
4246# FTP Protocol extensions permit the use of a special "EPSV" command.
4247#
4248# NATs may be able to put the connection on a "fast path" through the
4249# translator using EPSV, as the EPRT command will never be used
4250# and therefore, translation of the data portion of the segments
4251# will never be needed.
4252#
4253# EPSV is often required to interoperate with FTP servers on IPv6
4254# networks. On the other hand, it may break some IPv4 servers.
4255#
4256# By default, EPSV may try EPSV with any FTP server. To fine tune
4257# that decision, you may restrict EPSV to certain clients or servers
4258# using ACLs:
4259#
4260# ftp_epsv allow|deny al1 acl2 ...
4261#
4262# WARNING: Disabling EPSV may cause problems with external NAT and IPv6.
4263#
4264# Only fast ACLs are supported.
4265# Requires ftp_passive to be ON (default) for any effect.
4266#Default:
4267# none
4268
4269# TAG: ftp_eprt
4270# FTP Protocol extensions permit the use of a special "EPRT" command.
4271#
4272# This extension provides a protocol neutral alternative to the
4273# IPv4-only PORT command. When supported it enables active FTP data
4274# channels over IPv6 and efficient NAT handling.
4275#
4276# Turning this OFF will prevent EPRT being attempted and will skip
4277# straight to using PORT for IPv4 servers.
4278#
4279# Some devices are known to not handle this extension correctly and
4280# may result in crashes. Devices which suport EPRT enough to fail
4281# cleanly will result in Squid attempting PORT anyway. This directive
4282# should only be disabled when EPRT results in device failures.
4283#
4284# WARNING: Doing so will convert Squid back to the old behavior with all
4285# the related problems with external NAT devices/layers and IPv4-only FTP.
4286#Default:
4287# ftp_eprt on
4288
4289# TAG: ftp_sanitycheck
4290# For security and data integrity reasons Squid by default performs
4291# sanity checks of the addresses of FTP data connections ensure the
4292# data connection is to the requested server. If you need to allow
4293# FTP connections to servers using another IP address for the data
4294# connection turn this off.
4295#Default:
4296# ftp_sanitycheck on
4297
4298# TAG: ftp_telnet_protocol
4299# The FTP protocol is officially defined to use the telnet protocol
4300# as transport channel for the control connection. However, many
4301# implementations are broken and does not respect this aspect of
4302# the FTP protocol.
4303#
4304# If you have trouble accessing files with ASCII code 255 in the
4305# path or similar problems involving this ASCII code you can
4306# try setting this directive to off. If that helps, report to the
4307# operator of the FTP server in question that their FTP server
4308# is broken and does not follow the FTP standard.
4309#Default:
4310# ftp_telnet_protocol on
4311
4312# OPTIONS FOR EXTERNAL SUPPORT PROGRAMS
4313# -----------------------------------------------------------------------------
4314
4315# TAG: diskd_program
4316# Specify the location of the diskd executable.
4317# Note this is only useful if you have compiled in
4318# diskd as one of the store io modules.
4319#Default:
4320# diskd_program /usr/lib/squid/diskd
4321
4322# TAG: unlinkd_program
4323# Specify the location of the executable for file deletion process.
4324#Default:
4325# unlinkd_program /usr/lib/squid/unlinkd
4326
4327# TAG: pinger_program
4328# Note: This option is only available if Squid is rebuilt with the
4329# --enable-icmp
4330#
4331# Specify the location of the executable for the pinger process.
4332#Default:
4333# pinger_program /usr/lib/squid/pinger
4334
4335# TAG: pinger_enable
4336# Note: This option is only available if Squid is rebuilt with the
4337# --enable-icmp
4338#
4339# Control whether the pinger is active at run-time.
4340# Enables turning ICMP pinger on and off with a simple
4341# squid -k reconfigure.
4342#Default:
4343# pinger_enable on
4344
4345# OPTIONS FOR URL REWRITING
4346# -----------------------------------------------------------------------------
4347
4348# TAG: url_rewrite_program
4349# Specify the location of the executable URL rewriter to use.
4350# Since they can perform almost any function there isn't one included.
4351#
4352# For each requested URL, the rewriter will receive on line with the format
4353#
4354# [channel-ID <SP>] URL [<SP> extras]<NL>
4355#
4356# See url_rewrite_extras on how to send "extras" with optional values to
4357# the helper.
4358# After processing the request the helper must reply using the following format:
4359#
4360# [channel-ID <SP>] result [<SP> kv-pairs]
4361#
4362# The result code can be:
4363#
4364# OK status=30N url="..."
4365# Redirect the URL to the one supplied in 'url='.
4366# 'status=' is optional and contains the status code to send
4367# the client in Squids HTTP response. It must be one of the
4368# HTTP redirect status codes: 301, 302, 303, 307, 308.
4369# When no status is given Squid will use 302.
4370#
4371# OK rewrite-url="..."
4372# Rewrite the URL to the one supplied in 'rewrite-url='.
4373# The new URL is fetched directly by Squid and returned to
4374# the client as the response to its request.
4375#
4376# OK
4377# When neither of url= and rewrite-url= are sent Squid does
4378# not change the URL.
4379#
4380# ERR
4381# Do not change the URL.
4382#
4383# BH
4384# An internal error occurred in the helper, preventing
4385# a result being identified. The 'message=' key name is
4386# reserved for delivering a log message.
4387#
4388#
4389# In addition to the above kv-pairs Squid also understands the following
4390# optional kv-pairs received from URL rewriters:
4391# clt_conn_tag=TAG
4392# Associates a TAG with the client TCP connection.
4393# The TAG is treated as a regular annotation but persists across
4394# future requests on the client connection rather than just the
4395# current request. A helper may update the TAG during subsequent
4396# requests be returning a new kv-pair.
4397#
4398# When using the concurrency= option the protocol is changed by
4399# introducing a query channel tag in front of the request/response.
4400# The query channel tag is a number between 0 and concurrency-1.
4401# This value must be echoed back unchanged to Squid as the first part
4402# of the response relating to its request.
4403#
4404# WARNING: URL re-writing ability should be avoided whenever possible.
4405# Use the URL redirect form of response instead.
4406#
4407# Re-write creates a difference in the state held by the client
4408# and server. Possibly causing confusion when the server response
4409# contains snippets of its view state. Embeded URLs, response
4410# and content Location headers, etc. are not re-written by this
4411# interface.
4412#
4413# By default, a URL rewriter is not used.
4414#Default:
4415# none
4416
4417# TAG: url_rewrite_children
4418# The maximum number of redirector processes to spawn. If you limit
4419# it too few Squid will have to wait for them to process a backlog of
4420# URLs, slowing it down. If you allow too many they will use RAM
4421# and other system resources noticably.
4422#
4423# The startup= and idle= options allow some measure of skew in your
4424# tuning.
4425#
4426# startup=
4427#
4428# Sets a minimum of how many processes are to be spawned when Squid
4429# starts or reconfigures. When set to zero the first request will
4430# cause spawning of the first child process to handle it.
4431#
4432# Starting too few will cause an initial slowdown in traffic as Squid
4433# attempts to simultaneously spawn enough processes to cope.
4434#
4435# idle=
4436#
4437# Sets a minimum of how many processes Squid is to try and keep available
4438# at all times. When traffic begins to rise above what the existing
4439# processes can handle this many more will be spawned up to the maximum
4440# configured. A minimum setting of 1 is required.
4441#
4442# concurrency=
4443#
4444# The number of requests each redirector helper can handle in
4445# parallel. Defaults to 0 which indicates the redirector
4446# is a old-style single threaded redirector.
4447#
4448# When this directive is set to a value >= 1 then the protocol
4449# used to communicate with the helper is modified to include
4450# an ID in front of the request/response. The ID from the request
4451# must be echoed back with the response to that request.
4452#Default:
4453# url_rewrite_children 20 startup=0 idle=1 concurrency=0
4454
4455# TAG: url_rewrite_host_header
4456# To preserve same-origin security policies in browsers and
4457# prevent Host: header forgery by redirectors Squid rewrites
4458# any Host: header in redirected requests.
4459#
4460# If you are running an accelerator this may not be a wanted
4461# effect of a redirector. This directive enables you disable
4462# Host: alteration in reverse-proxy traffic.
4463#
4464# WARNING: Entries are cached on the result of the URL rewriting
4465# process, so be careful if you have domain-virtual hosts.
4466#
4467# WARNING: Squid and other software verifies the URL and Host
4468# are matching, so be careful not to relay through other proxies
4469# or inspecting firewalls with this disabled.
4470#Default:
4471# url_rewrite_host_header on
4472
4473# TAG: url_rewrite_access
4474# If defined, this access list specifies which requests are
4475# sent to the redirector processes.
4476#
4477# This clause supports both fast and slow acl types.
4478# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4479#Default:
4480# Allow, unless rules exist in squid.conf.
4481
4482# TAG: url_rewrite_bypass
4483# When this is 'on', a request will not go through the
4484# redirector if all the helpers are busy. If this is 'off'
4485# and the redirector queue grows too large, Squid will exit
4486# with a FATAL error and ask you to increase the number of
4487# redirectors. You should only enable this if the redirectors
4488# are not critical to your caching system. If you use
4489# redirectors for access control, and you enable this option,
4490# users may have access to pages they should not
4491# be allowed to request.
4492#Default:
4493# url_rewrite_bypass off
4494
4495# TAG: url_rewrite_extras
4496# Specifies a string to be append to request line format for the
4497# rewriter helper. "Quoted" format values may contain spaces and
4498# logformat %macros. In theory, any logformat %macro can be used.
4499# In practice, a %macro expands as a dash (-) if the helper request is
4500# sent before the required macro information is available to Squid.
4501#Default:
4502# url_rewrite_extras "%>a/%>A %un %>rm myip=%la myport=%lp"
4503
4504# OPTIONS FOR STORE ID
4505# -----------------------------------------------------------------------------
4506
4507# TAG: store_id_program
4508# Specify the location of the executable StoreID helper to use.
4509# Since they can perform almost any function there isn't one included.
4510#
4511# For each requested URL, the helper will receive one line with the format
4512#
4513# [channel-ID <SP>] URL [<SP> extras]<NL>
4514#
4515#
4516# After processing the request the helper must reply using the following format:
4517#
4518# [channel-ID <SP>] result [<SP> kv-pairs]
4519#
4520# The result code can be:
4521#
4522# OK store-id="..."
4523# Use the StoreID supplied in 'store-id='.
4524#
4525# ERR
4526# The default is to use HTTP request URL as the store ID.
4527#
4528# BH
4529# An internal error occured in the helper, preventing
4530# a result being identified.
4531#
4532# In addition to the above kv-pairs Squid also understands the following
4533# optional kv-pairs received from URL rewriters:
4534# clt_conn_tag=TAG
4535# Associates a TAG with the client TCP connection.
4536# Please see url_rewrite_program related documentation for this
4537# kv-pair
4538#
4539# Helper programs should be prepared to receive and possibly ignore
4540# additional whitespace-separated tokens on each input line.
4541#
4542# When using the concurrency= option the protocol is changed by
4543# introducing a query channel tag in front of the request/response.
4544# The query channel tag is a number between 0 and concurrency-1.
4545# This value must be echoed back unchanged to Squid as the first part
4546# of the response relating to its request.
4547#
4548# NOTE: when using StoreID refresh_pattern will apply to the StoreID
4549# returned from the helper and not the URL.
4550#
4551# WARNING: Wrong StoreID value returned by a careless helper may result
4552# in the wrong cached response returned to the user.
4553#
4554# By default, a StoreID helper is not used.
4555#Default:
4556# none
4557
4558# TAG: store_id_extras
4559# Specifies a string to be append to request line format for the
4560# StoreId helper. "Quoted" format values may contain spaces and
4561# logformat %macros. In theory, any logformat %macro can be used.
4562# In practice, a %macro expands as a dash (-) if the helper request is
4563# sent before the required macro information is available to Squid.
4564#Default:
4565# store_id_extras "%>a/%>A %un %>rm myip=%la myport=%lp"
4566
4567# TAG: store_id_children
4568# The maximum number of StoreID helper processes to spawn. If you limit
4569# it too few Squid will have to wait for them to process a backlog of
4570# requests, slowing it down. If you allow too many they will use RAM
4571# and other system resources noticably.
4572#
4573# The startup= and idle= options allow some measure of skew in your
4574# tuning.
4575#
4576# startup=
4577#
4578# Sets a minimum of how many processes are to be spawned when Squid
4579# starts or reconfigures. When set to zero the first request will
4580# cause spawning of the first child process to handle it.
4581#
4582# Starting too few will cause an initial slowdown in traffic as Squid
4583# attempts to simultaneously spawn enough processes to cope.
4584#
4585# idle=
4586#
4587# Sets a minimum of how many processes Squid is to try and keep available
4588# at all times. When traffic begins to rise above what the existing
4589# processes can handle this many more will be spawned up to the maximum
4590# configured. A minimum setting of 1 is required.
4591#
4592# concurrency=
4593#
4594# The number of requests each storeID helper can handle in
4595# parallel. Defaults to 0 which indicates the helper
4596# is a old-style single threaded program.
4597#
4598# When this directive is set to a value >= 1 then the protocol
4599# used to communicate with the helper is modified to include
4600# an ID in front of the request/response. The ID from the request
4601# must be echoed back with the response to that request.
4602#Default:
4603# store_id_children 20 startup=0 idle=1 concurrency=0
4604
4605# TAG: store_id_access
4606# If defined, this access list specifies which requests are
4607# sent to the StoreID processes. By default all requests
4608# are sent.
4609#
4610# This clause supports both fast and slow acl types.
4611# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4612#Default:
4613# Allow, unless rules exist in squid.conf.
4614
4615# TAG: store_id_bypass
4616# When this is 'on', a request will not go through the
4617# helper if all helpers are busy. If this is 'off'
4618# and the helper queue grows too large, Squid will exit
4619# with a FATAL error and ask you to increase the number of
4620# helpers. You should only enable this if the helperss
4621# are not critical to your caching system. If you use
4622# helpers for critical caching components, and you enable this
4623# option, users may not get objects from cache.
4624#Default:
4625# store_id_bypass on
4626
4627# OPTIONS FOR TUNING THE CACHE
4628# -----------------------------------------------------------------------------
4629
4630# TAG: cache
4631# Requests denied by this directive will not be served from the cache
4632# and their responses will not be stored in the cache. This directive
4633# has no effect on other transactions and on already cached responses.
4634#
4635# This clause supports both fast and slow acl types.
4636# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4637#
4638# This and the two other similar caching directives listed below are
4639# checked at different transaction processing stages, have different
4640# access to response information, affect different cache operations,
4641# and differ in slow ACLs support:
4642#
4643# * cache: Checked before Squid makes a hit/miss determination.
4644# No access to reply information!
4645# Denies both serving a hit and storing a miss.
4646# Supports both fast and slow ACLs.
4647# * send_hit: Checked after a hit was detected.
4648# Has access to reply (hit) information.
4649# Denies serving a hit only.
4650# Supports fast ACLs only.
4651# * store_miss: Checked before storing a cachable miss.
4652# Has access to reply (miss) information.
4653# Denies storing a miss only.
4654# Supports fast ACLs only.
4655#
4656# If you are not sure which of the three directives to use, apply the
4657# following decision logic:
4658#
4659# * If your ACL(s) are of slow type _and_ need response info, redesign.
4660# Squid does not support that particular combination at this time.
4661# Otherwise:
4662# * If your directive ACL(s) are of slow type, use "cache"; and/or
4663# * if your directive ACL(s) need no response info, use "cache".
4664# Otherwise:
4665# * If you do not want the response cached, use store_miss; and/or
4666# * if you do not want a hit on a cached response, use send_hit.
4667#Default:
4668# By default, this directive is unused and has no effect.
4669
4670# TAG: send_hit
4671# Responses denied by this directive will not be served from the cache
4672# (but may still be cached, see store_miss). This directive has no
4673# effect on the responses it allows and on the cached objects.
4674#
4675# Please see the "cache" directive for a summary of differences among
4676# store_miss, send_hit, and cache directives.
4677#
4678# Unlike the "cache" directive, send_hit only supports fast acl
4679# types. See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4680#
4681# For example:
4682#
4683# # apply custom Store ID mapping to some URLs
4684# acl MapMe dstdomain .c.example.com
4685# store_id_program ...
4686# store_id_access allow MapMe
4687#
4688# # but prevent caching of special responses
4689# # such as 302 redirects that cause StoreID loops
4690# acl Ordinary http_status 200-299
4691# store_miss deny MapMe !Ordinary
4692#
4693# # and do not serve any previously stored special responses
4694# # from the cache (in case they were already cached before
4695# # the above store_miss rule was in effect).
4696# send_hit deny MapMe !Ordinary
4697#Default:
4698# By default, this directive is unused and has no effect.
4699
4700# TAG: store_miss
4701# Responses denied by this directive will not be cached (but may still
4702# be served from the cache, see send_hit). This directive has no
4703# effect on the responses it allows and on the already cached responses.
4704#
4705# Please see the "cache" directive for a summary of differences among
4706# store_miss, send_hit, and cache directives. See the
4707# send_hit directive for a usage example.
4708#
4709# Unlike the "cache" directive, store_miss only supports fast acl
4710# types. See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4711#Default:
4712# By default, this directive is unused and has no effect.
4713
4714# TAG: max_stale time-units
4715# This option puts an upper limit on how stale content Squid
4716# will serve from the cache if cache validation fails.
4717# Can be overriden by the refresh_pattern max-stale option.
4718#Default:
4719# max_stale 1 week
4720
4721# TAG: refresh_pattern
4722# usage: refresh_pattern [-i] regex min percent max [options]
4723#
4724# By default, regular expressions are CASE-SENSITIVE. To make
4725# them case-insensitive, use the -i option.
4726#
4727# 'Min' is the time (in minutes) an object without an explicit
4728# expiry time should be considered fresh. The recommended
4729# value is 0, any higher values may cause dynamic applications
4730# to be erroneously cached unless the application designer
4731# has taken the appropriate actions.
4732#
4733# 'Percent' is a percentage of the objects age (time since last
4734# modification age) an object without explicit expiry time
4735# will be considered fresh.
4736#
4737# 'Max' is an upper limit on how long objects without an explicit
4738# expiry time will be considered fresh.
4739#
4740# options: override-expire
4741# override-lastmod
4742# reload-into-ims
4743# ignore-reload
4744# ignore-no-store
4745# ignore-must-revalidate
4746# ignore-private
4747# ignore-auth
4748# max-stale=NN
4749# refresh-ims
4750# store-stale
4751#
4752# override-expire enforces min age even if the server
4753# sent an explicit expiry time (e.g., with the
4754# Expires: header or Cache-Control: max-age). Doing this
4755# VIOLATES the HTTP standard. Enabling this feature
4756# could make you liable for problems which it causes.
4757#
4758# Note: override-expire does not enforce staleness - it only extends
4759# freshness / min. If the server returns a Expires time which
4760# is longer than your max time, Squid will still consider
4761# the object fresh for that period of time.
4762#
4763# override-lastmod enforces min age even on objects
4764# that were modified recently.
4765#
4766# reload-into-ims changes a client no-cache or ``reload''
4767# request for a cached entry into a conditional request using
4768# If-Modified-Since and/or If-None-Match headers, provided the
4769# cached entry has a Last-Modified and/or a strong ETag header.
4770# Doing this VIOLATES the HTTP standard. Enabling this feature
4771# could make you liable for problems which it causes.
4772#
4773# ignore-reload ignores a client no-cache or ``reload''
4774# header. Doing this VIOLATES the HTTP standard. Enabling
4775# this feature could make you liable for problems which
4776# it causes.
4777#
4778# ignore-no-store ignores any ``Cache-control: no-store''
4779# headers received from a server. Doing this VIOLATES
4780# the HTTP standard. Enabling this feature could make you
4781# liable for problems which it causes.
4782#
4783# ignore-must-revalidate ignores any ``Cache-Control: must-revalidate``
4784# headers received from a server. Doing this VIOLATES
4785# the HTTP standard. Enabling this feature could make you
4786# liable for problems which it causes.
4787#
4788# ignore-private ignores any ``Cache-control: private''
4789# headers received from a server. Doing this VIOLATES
4790# the HTTP standard. Enabling this feature could make you
4791# liable for problems which it causes.
4792#
4793# ignore-auth caches responses to requests with authorization,
4794# as if the originserver had sent ``Cache-control: public''
4795# in the response header. Doing this VIOLATES the HTTP standard.
4796# Enabling this feature could make you liable for problems which
4797# it causes.
4798#
4799# refresh-ims causes squid to contact the origin server
4800# when a client issues an If-Modified-Since request. This
4801# ensures that the client will receive an updated version
4802# if one is available.
4803#
4804# store-stale stores responses even if they don't have explicit
4805# freshness or a validator (i.e., Last-Modified or an ETag)
4806# present, or if they're already stale. By default, Squid will
4807# not cache such responses because they usually can't be
4808# reused. Note that such responses will be stale by default.
4809#
4810# max-stale=NN provide a maximum staleness factor. Squid won't
4811# serve objects more stale than this even if it failed to
4812# validate the object. Default: use the max_stale global limit.
4813#
4814# Basically a cached object is:
4815#
4816# FRESH if expire > now, else STALE
4817# STALE if age > max
4818# FRESH if lm-factor < percent, else STALE
4819# FRESH if age < min
4820# else STALE
4821#
4822# The refresh_pattern lines are checked in the order listed here.
4823# The first entry which matches is used. If none of the entries
4824# match the default will be used.
4825#
4826# Note, you must uncomment all the default lines if you want
4827# to change one. The default setting is only active if none is
4828# used.
4829#
4830#
4831
4832#
4833# Add any of your own refresh_pattern entries above these.
4834#
4835refresh_pattern ^ftp: 1440 20% 10080
4836refresh_pattern ^gopher: 1440 0% 1440
4837refresh_pattern -i (/cgi-bin/|\?) 0 0% 0
4838refresh_pattern . 0 20% 4320
4839
4840# TAG: quick_abort_min (KB)
4841#Default:
4842# quick_abort_min 16 KB
4843
4844# TAG: quick_abort_max (KB)
4845#Default:
4846# quick_abort_max 16 KB
4847
4848# TAG: quick_abort_pct (percent)
4849# The cache by default continues downloading aborted requests
4850# which are almost completed (less than 16 KB remaining). This
4851# may be undesirable on slow (e.g. SLIP) links and/or very busy
4852# caches. Impatient users may tie up file descriptors and
4853# bandwidth by repeatedly requesting and immediately aborting
4854# downloads.
4855#
4856# When the user aborts a request, Squid will check the
4857# quick_abort values to the amount of data transferred until
4858# then.
4859#
4860# If the transfer has less than 'quick_abort_min' KB remaining,
4861# it will finish the retrieval.
4862#
4863# If the transfer has more than 'quick_abort_max' KB remaining,
4864# it will abort the retrieval.
4865#
4866# If more than 'quick_abort_pct' of the transfer has completed,
4867# it will finish the retrieval.
4868#
4869# If you do not want any retrieval to continue after the client
4870# has aborted, set both 'quick_abort_min' and 'quick_abort_max'
4871# to '0 KB'.
4872#
4873# If you want retrievals to always continue if they are being
4874# cached set 'quick_abort_min' to '-1 KB'.
4875#Default:
4876# quick_abort_pct 95
4877
4878# TAG: read_ahead_gap buffer-size
4879# The amount of data the cache will buffer ahead of what has been
4880# sent to the client when retrieving an object from another server.
4881#Default:
4882# read_ahead_gap 16 KB
4883
4884# TAG: negative_ttl time-units
4885# Set the Default Time-to-Live (TTL) for failed requests.
4886# Certain types of failures (such as "connection refused" and
4887# "404 Not Found") are able to be negatively-cached for a short time.
4888# Modern web servers should provide Expires: header, however if they
4889# do not this can provide a minimum TTL.
4890# The default is not to cache errors with unknown expiry details.
4891#
4892# Note that this is different from negative caching of DNS lookups.
4893#
4894# WARNING: Doing this VIOLATES the HTTP standard. Enabling
4895# this feature could make you liable for problems which it
4896# causes.
4897#Default:
4898# negative_ttl 0 seconds
4899
4900# TAG: positive_dns_ttl time-units
4901# Upper limit on how long Squid will cache positive DNS responses.
4902# Default is 6 hours (360 minutes). This directive must be set
4903# larger than negative_dns_ttl.
4904#Default:
4905# positive_dns_ttl 6 hours
4906
4907# TAG: negative_dns_ttl time-units
4908# Time-to-Live (TTL) for negative caching of failed DNS lookups.
4909# This also sets the lower cache limit on positive lookups.
4910# Minimum value is 1 second, and it is not recommendable to go
4911# much below 10 seconds.
4912#Default:
4913# negative_dns_ttl 1 minutes
4914
4915# TAG: range_offset_limit size [acl acl...]
4916# usage: (size) [units] [[!]aclname]
4917#
4918# Sets an upper limit on how far (number of bytes) into the file
4919# a Range request may be to cause Squid to prefetch the whole file.
4920# If beyond this limit, Squid forwards the Range request as it is and
4921# the result is NOT cached.
4922#
4923# This is to stop a far ahead range request (lets say start at 17MB)
4924# from making Squid fetch the whole object up to that point before
4925# sending anything to the client.
4926#
4927# Multiple range_offset_limit lines may be specified, and they will
4928# be searched from top to bottom on each request until a match is found.
4929# The first match found will be used. If no line matches a request, the
4930# default limit of 0 bytes will be used.
4931#
4932# 'size' is the limit specified as a number of units.
4933#
4934# 'units' specifies whether to use bytes, KB, MB, etc.
4935# If no units are specified bytes are assumed.
4936#
4937# A size of 0 causes Squid to never fetch more than the
4938# client requested. (default)
4939#
4940# A size of 'none' causes Squid to always fetch the object from the
4941# beginning so it may cache the result. (2.0 style)
4942#
4943# 'aclname' is the name of a defined ACL.
4944#
4945# NP: Using 'none' as the byte value here will override any quick_abort settings
4946# that may otherwise apply to the range request. The range request will
4947# be fully fetched from start to finish regardless of the client
4948# actions. This affects bandwidth usage.
4949#Default:
4950# none
4951
4952# TAG: minimum_expiry_time (seconds)
4953# The minimum caching time according to (Expires - Date)
4954# headers Squid honors if the object can't be revalidated.
4955# The default is 60 seconds.
4956#
4957# In reverse proxy environments it might be desirable to honor
4958# shorter object lifetimes. It is most likely better to make
4959# your server return a meaningful Last-Modified header however.
4960#
4961# In ESI environments where page fragments often have short
4962# lifetimes, this will often be best set to 0.
4963#Default:
4964# minimum_expiry_time 60 seconds
4965
4966# TAG: store_avg_object_size (bytes)
4967# Average object size, used to estimate number of objects your
4968# cache can hold. The default is 13 KB.
4969#
4970# This is used to pre-seed the cache index memory allocation to
4971# reduce expensive reallocate operations while handling clients
4972# traffic. Too-large values may result in memory allocation during
4973# peak traffic, too-small values will result in wasted memory.
4974#
4975# Check the cache manager 'info' report metrics for the real
4976# object sizes seen by your Squid before tuning this.
4977#Default:
4978# store_avg_object_size 13 KB
4979
4980# TAG: store_objects_per_bucket
4981# Target number of objects per bucket in the store hash table.
4982# Lowering this value increases the total number of buckets and
4983# also the storage maintenance rate. The default is 20.
4984#Default:
4985# store_objects_per_bucket 20
4986
4987# HTTP OPTIONS
4988# -----------------------------------------------------------------------------
4989
4990# TAG: request_header_max_size (KB)
4991# This specifies the maximum size for HTTP headers in a request.
4992# Request headers are usually relatively small (about 512 bytes).
4993# Placing a limit on the request header size will catch certain
4994# bugs (for example with persistent connections) and possibly
4995# buffer-overflow or denial-of-service attacks.
4996#Default:
4997# request_header_max_size 64 KB
4998
4999# TAG: reply_header_max_size (KB)
5000# This specifies the maximum size for HTTP headers in a reply.
5001# Reply headers are usually relatively small (about 512 bytes).
5002# Placing a limit on the reply header size will catch certain
5003# bugs (for example with persistent connections) and possibly
5004# buffer-overflow or denial-of-service attacks.
5005#Default:
5006# reply_header_max_size 64 KB
5007
5008# TAG: request_body_max_size (bytes)
5009# This specifies the maximum size for an HTTP request body.
5010# In other words, the maximum size of a PUT/POST request.
5011# A user who attempts to send a request with a body larger
5012# than this limit receives an "Invalid Request" error message.
5013# If you set this parameter to a zero (the default), there will
5014# be no limit imposed.
5015#
5016# See also client_request_buffer_max_size for an alternative
5017# limitation on client uploads which can be configured.
5018#Default:
5019# No limit.
5020
5021# TAG: client_request_buffer_max_size (bytes)
5022# This specifies the maximum buffer size of a client request.
5023# It prevents squid eating too much memory when somebody uploads
5024# a large file.
5025#Default:
5026# client_request_buffer_max_size 512 KB
5027
5028# TAG: broken_posts
5029# A list of ACL elements which, if matched, causes Squid to send
5030# an extra CRLF pair after the body of a PUT/POST request.
5031#
5032# Some HTTP servers has broken implementations of PUT/POST,
5033# and rely on an extra CRLF pair sent by some WWW clients.
5034#
5035# Quote from RFC2616 section 4.1 on this matter:
5036#
5037# Note: certain buggy HTTP/1.0 client implementations generate an
5038# extra CRLF's after a POST request. To restate what is explicitly
5039# forbidden by the BNF, an HTTP/1.1 client must not preface or follow
5040# a request with an extra CRLF.
5041#
5042# This clause only supports fast acl types.
5043# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5044#
5045#Example:
5046# acl buggy_server url_regex ^http://....
5047# broken_posts allow buggy_server
5048#Default:
5049# Obey RFC 2616.
5050
5051# TAG: adaptation_uses_indirect_client on|off
5052# Controls whether the indirect client IP address (instead of the direct
5053# client IP address) is passed to adaptation services.
5054#
5055# See also: follow_x_forwarded_for adaptation_send_client_ip
5056#Default:
5057# adaptation_uses_indirect_client on
5058
5059# TAG: via on|off
5060# If set (default), Squid will include a Via header in requests and
5061# replies as required by RFC2616.
5062#Default:
5063# via on
5064
5065# TAG: ie_refresh on|off
5066# Microsoft Internet Explorer up until version 5.5 Service
5067# Pack 1 has an issue with transparent proxies, wherein it
5068# is impossible to force a refresh. Turning this on provides
5069# a partial fix to the problem, by causing all IMS-REFRESH
5070# requests from older IE versions to check the origin server
5071# for fresh content. This reduces hit ratio by some amount
5072# (~10% in my experience), but allows users to actually get
5073# fresh content when they want it. Note because Squid
5074# cannot tell if the user is using 5.5 or 5.5SP1, the behavior
5075# of 5.5 is unchanged from old versions of Squid (i.e. a
5076# forced refresh is impossible). Newer versions of IE will,
5077# hopefully, continue to have the new behavior and will be
5078# handled based on that assumption. This option defaults to
5079# the old Squid behavior, which is better for hit ratios but
5080# worse for clients using IE, if they need to be able to
5081# force fresh content.
5082#Default:
5083# ie_refresh off
5084
5085# TAG: vary_ignore_expire on|off
5086# Many HTTP servers supporting Vary gives such objects
5087# immediate expiry time with no cache-control header
5088# when requested by a HTTP/1.0 client. This option
5089# enables Squid to ignore such expiry times until
5090# HTTP/1.1 is fully implemented.
5091#
5092# WARNING: If turned on this may eventually cause some
5093# varying objects not intended for caching to get cached.
5094#Default:
5095# vary_ignore_expire off
5096
5097# TAG: request_entities
5098# Squid defaults to deny GET and HEAD requests with request entities,
5099# as the meaning of such requests are undefined in the HTTP standard
5100# even if not explicitly forbidden.
5101#
5102# Set this directive to on if you have clients which insists
5103# on sending request entities in GET or HEAD requests. But be warned
5104# that there is server software (both proxies and web servers) which
5105# can fail to properly process this kind of request which may make you
5106# vulnerable to cache pollution attacks if enabled.
5107#Default:
5108# request_entities off
5109
5110# TAG: request_header_access
5111# Usage: request_header_access header_name allow|deny [!]aclname ...
5112#
5113# WARNING: Doing this VIOLATES the HTTP standard. Enabling
5114# this feature could make you liable for problems which it
5115# causes.
5116#
5117# This option replaces the old 'anonymize_headers' and the
5118# older 'http_anonymizer' option with something that is much
5119# more configurable. A list of ACLs for each header name allows
5120# removal of specific header fields under specific conditions.
5121#
5122# This option only applies to outgoing HTTP request headers (i.e.,
5123# headers sent by Squid to the next HTTP hop such as a cache peer
5124# or an origin server). The option has no effect during cache hit
5125# detection. The equivalent adaptation vectoring point in ICAP
5126# terminology is post-cache REQMOD.
5127#
5128# The option is applied to individual outgoing request header
5129# fields. For each request header field F, Squid uses the first
5130# qualifying sets of request_header_access rules:
5131#
5132# 1. Rules with header_name equal to F's name.
5133# 2. Rules with header_name 'Other', provided F's name is not
5134# on the hard-coded list of commonly used HTTP header names.
5135# 3. Rules with header_name 'All'.
5136#
5137# Within that qualifying rule set, rule ACLs are checked as usual.
5138# If ACLs of an "allow" rule match, the header field is allowed to
5139# go through as is. If ACLs of a "deny" rule match, the header is
5140# removed and request_header_replace is then checked to identify
5141# if the removed header has a replacement. If no rules within the
5142# set have matching ACLs, the header field is left as is.
5143#
5144# For example, to achieve the same behavior as the old
5145# 'http_anonymizer standard' option, you should use:
5146#
5147# request_header_access From deny all
5148# request_header_access Referer deny all
5149# request_header_access User-Agent deny all
5150#
5151# Or, to reproduce the old 'http_anonymizer paranoid' feature
5152# you should use:
5153#
5154# request_header_access Authorization allow all
5155# request_header_access Proxy-Authorization allow all
5156# request_header_access Cache-Control allow all
5157# request_header_access Content-Length allow all
5158# request_header_access Content-Type allow all
5159# request_header_access Date allow all
5160# request_header_access Host allow all
5161# request_header_access If-Modified-Since allow all
5162# request_header_access Pragma allow all
5163# request_header_access Accept allow all
5164# request_header_access Accept-Charset allow all
5165# request_header_access Accept-Encoding allow all
5166# request_header_access Accept-Language allow all
5167# request_header_access Connection allow all
5168# request_header_access All deny all
5169#
5170# HTTP reply headers are controlled with the reply_header_access directive.
5171#
5172# By default, all headers are allowed (no anonymizing is performed).
5173#Default:
5174# No limits.
5175
5176# TAG: reply_header_access
5177# Usage: reply_header_access header_name allow|deny [!]aclname ...
5178#
5179# WARNING: Doing this VIOLATES the HTTP standard. Enabling
5180# this feature could make you liable for problems which it
5181# causes.
5182#
5183# This option only applies to reply headers, i.e., from the
5184# server to the client.
5185#
5186# This is the same as request_header_access, but in the other
5187# direction. Please see request_header_access for detailed
5188# documentation.
5189#
5190# For example, to achieve the same behavior as the old
5191# 'http_anonymizer standard' option, you should use:
5192#
5193# reply_header_access Server deny all
5194# reply_header_access WWW-Authenticate deny all
5195# reply_header_access Link deny all
5196#
5197# Or, to reproduce the old 'http_anonymizer paranoid' feature
5198# you should use:
5199#
5200# reply_header_access Allow allow all
5201# reply_header_access WWW-Authenticate allow all
5202# reply_header_access Proxy-Authenticate allow all
5203# reply_header_access Cache-Control allow all
5204# reply_header_access Content-Encoding allow all
5205# reply_header_access Content-Length allow all
5206# reply_header_access Content-Type allow all
5207# reply_header_access Date allow all
5208# reply_header_access Expires allow all
5209# reply_header_access Last-Modified allow all
5210# reply_header_access Location allow all
5211# reply_header_access Pragma allow all
5212# reply_header_access Content-Language allow all
5213# reply_header_access Retry-After allow all
5214# reply_header_access Title allow all
5215# reply_header_access Content-Disposition allow all
5216# reply_header_access Connection allow all
5217# reply_header_access All deny all
5218#
5219# HTTP request headers are controlled with the request_header_access directive.
5220#
5221# By default, all headers are allowed (no anonymizing is
5222# performed).
5223#Default:
5224# No limits.
5225
5226# TAG: request_header_replace
5227# Usage: request_header_replace header_name message
5228# Example: request_header_replace User-Agent Nutscrape/1.0 (CP/M; 8-bit)
5229#
5230# This option allows you to change the contents of headers
5231# denied with request_header_access above, by replacing them
5232# with some fixed string.
5233#
5234# This only applies to request headers, not reply headers.
5235#
5236# By default, headers are removed if denied.
5237#Default:
5238# none
5239
5240# TAG: reply_header_replace
5241# Usage: reply_header_replace header_name message
5242# Example: reply_header_replace Server Foo/1.0
5243#
5244# This option allows you to change the contents of headers
5245# denied with reply_header_access above, by replacing them
5246# with some fixed string.
5247#
5248# This only applies to reply headers, not request headers.
5249#
5250# By default, headers are removed if denied.
5251#Default:
5252# none
5253
5254# TAG: request_header_add
5255# Usage: request_header_add field-name field-value acl1 [acl2] ...
5256# Example: request_header_add X-Client-CA "CA=%ssl::>cert_issuer" all
5257#
5258# This option adds header fields to outgoing HTTP requests (i.e.,
5259# request headers sent by Squid to the next HTTP hop such as a
5260# cache peer or an origin server). The option has no effect during
5261# cache hit detection. The equivalent adaptation vectoring point
5262# in ICAP terminology is post-cache REQMOD.
5263#
5264# Field-name is a token specifying an HTTP header name. If a
5265# standard HTTP header name is used, Squid does not check whether
5266# the new header conflicts with any existing headers or violates
5267# HTTP rules. If the request to be modified already contains a
5268# field with the same name, the old field is preserved but the
5269# header field values are not merged.
5270#
5271# Field-value is either a token or a quoted string. If quoted
5272# string format is used, then the surrounding quotes are removed
5273# while escape sequences and %macros are processed.
5274#
5275# In theory, all of the logformat codes can be used as %macros.
5276# However, unlike logging (which happens at the very end of
5277# transaction lifetime), the transaction may not yet have enough
5278# information to expand a macro when the new header value is needed.
5279# And some information may already be available to Squid but not yet
5280# committed where the macro expansion code can access it (report
5281# such instances!). The macro will be expanded into a single dash
5282# ('-') in such cases. Not all macros have been tested.
5283#
5284# One or more Squid ACLs may be specified to restrict header
5285# injection to matching requests. As always in squid.conf, all
5286# ACLs in an option ACL list must be satisfied for the insertion
5287# to happen. The request_header_add option supports fast ACLs
5288# only.
5289#Default:
5290# none
5291
5292# TAG: note
5293# This option used to log custom information about the master
5294# transaction. For example, an admin may configure Squid to log
5295# which "user group" the transaction belongs to, where "user group"
5296# will be determined based on a set of ACLs and not [just]
5297# authentication information.
5298# Values of key/value pairs can be logged using %{key}note macros:
5299#
5300# note key value acl ...
5301# logformat myFormat ... %{key}note ...
5302#Default:
5303# none
5304
5305# TAG: relaxed_header_parser on|off|warn
5306# In the default "on" setting Squid accepts certain forms
5307# of non-compliant HTTP messages where it is unambiguous
5308# what the sending application intended even if the message
5309# is not correctly formatted. The messages is then normalized
5310# to the correct form when forwarded by Squid.
5311#
5312# If set to "warn" then a warning will be emitted in cache.log
5313# each time such HTTP error is encountered.
5314#
5315# If set to "off" then such HTTP errors will cause the request
5316# or response to be rejected.
5317#Default:
5318# relaxed_header_parser on
5319
5320# TAG: collapsed_forwarding (on|off)
5321# This option controls whether Squid is allowed to merge multiple
5322# potentially cachable requests for the same URI before Squid knows
5323# whether the response is going to be cachable.
5324#
5325# This feature is disabled by default: Enabling collapsed forwarding
5326# needlessly delays forwarding requests that look cachable (when they are
5327# collapsed) but then need to be forwarded individually anyway because
5328# they end up being for uncachable content. However, in some cases, such
5329# as accelleration of highly cachable content with periodic or groupped
5330# expiration times, the gains from collapsing [large volumes of
5331# simultenous refresh requests] outweigh losses from such delays.
5332#Default:
5333# collapsed_forwarding off
5334
5335# TIMEOUTS
5336# -----------------------------------------------------------------------------
5337
5338# TAG: forward_timeout time-units
5339# This parameter specifies how long Squid should at most attempt in
5340# finding a forwarding path for the request before giving up.
5341#Default:
5342# forward_timeout 4 minutes
5343
5344# TAG: connect_timeout time-units
5345# This parameter specifies how long to wait for the TCP connect to
5346# the requested server or peer to complete before Squid should
5347# attempt to find another path where to forward the request.
5348#Default:
5349# connect_timeout 1 minute
5350
5351# TAG: peer_connect_timeout time-units
5352# This parameter specifies how long to wait for a pending TCP
5353# connection to a peer cache. The default is 30 seconds. You
5354# may also set different timeout values for individual neighbors
5355# with the 'connect-timeout' option on a 'cache_peer' line.
5356#Default:
5357# peer_connect_timeout 30 seconds
5358
5359# TAG: read_timeout time-units
5360# Applied on peer server connections.
5361#
5362# After each successful read(), the timeout will be extended by this
5363# amount. If no data is read again after this amount of time,
5364# the request is aborted and logged with ERR_READ_TIMEOUT.
5365#
5366# The default is 15 minutes.
5367#Default:
5368# read_timeout 15 minutes
5369
5370# TAG: write_timeout time-units
5371# This timeout is tracked for all connections that have data
5372# available for writing and are waiting for the socket to become
5373# ready. After each successful write, the timeout is extended by
5374# the configured amount. If Squid has data to write but the
5375# connection is not ready for the configured duration, the
5376# transaction associated with the connection is terminated. The
5377# default is 15 minutes.
5378#Default:
5379# write_timeout 15 minutes
5380
5381# TAG: request_timeout
5382# How long to wait for complete HTTP request headers after initial
5383# connection establishment.
5384#Default:
5385# request_timeout 5 minutes
5386
5387# TAG: client_idle_pconn_timeout
5388# How long to wait for the next HTTP request on a persistent
5389# client connection after the previous request completes.
5390#Default:
5391# client_idle_pconn_timeout 2 minutes
5392
5393# TAG: ftp_client_idle_timeout
5394# How long to wait for an FTP request on a connection to Squid ftp_port.
5395# Many FTP clients do not deal with idle connection closures well,
5396# necessitating a longer default timeout than client_idle_pconn_timeout
5397# used for incoming HTTP requests.
5398#Default:
5399# ftp_client_idle_timeout 30 minutes
5400
5401# TAG: client_lifetime time-units
5402# The maximum amount of time a client (browser) is allowed to
5403# remain connected to the cache process. This protects the Cache
5404# from having a lot of sockets (and hence file descriptors) tied up
5405# in a CLOSE_WAIT state from remote clients that go away without
5406# properly shutting down (either because of a network failure or
5407# because of a poor client implementation). The default is one
5408# day, 1440 minutes.
5409#
5410# NOTE: The default value is intended to be much larger than any
5411# client would ever need to be connected to your cache. You
5412# should probably change client_lifetime only as a last resort.
5413# If you seem to have many client connections tying up
5414# filedescriptors, we recommend first tuning the read_timeout,
5415# request_timeout, persistent_request_timeout and quick_abort values.
5416#Default:
5417# client_lifetime 1 day
5418
5419# TAG: half_closed_clients
5420# Some clients may shutdown the sending side of their TCP
5421# connections, while leaving their receiving sides open. Sometimes,
5422# Squid can not tell the difference between a half-closed and a
5423# fully-closed TCP connection.
5424#
5425# By default, Squid will immediately close client connections when
5426# read(2) returns "no more data to read."
5427#
5428# Change this option to 'on' and Squid will keep open connections
5429# until a read(2) or write(2) on the socket returns an error.
5430# This may show some benefits for reverse proxies. But if not
5431# it is recommended to leave OFF.
5432#Default:
5433# half_closed_clients off
5434
5435# TAG: server_idle_pconn_timeout
5436# Timeout for idle persistent connections to servers and other
5437# proxies.
5438#Default:
5439# server_idle_pconn_timeout 1 minute
5440
5441# TAG: ident_timeout
5442# Maximum time to wait for IDENT lookups to complete.
5443#
5444# If this is too high, and you enabled IDENT lookups from untrusted
5445# users, you might be susceptible to denial-of-service by having
5446# many ident requests going at once.
5447#Default:
5448# ident_timeout 10 seconds
5449
5450# TAG: shutdown_lifetime time-units
5451# When SIGTERM or SIGHUP is received, the cache is put into
5452# "shutdown pending" mode until all active sockets are closed.
5453# This value is the lifetime to set for all open descriptors
5454# during shutdown mode. Any active clients after this many
5455# seconds will receive a 'timeout' message.
5456#Default:
5457# shutdown_lifetime 30 seconds
5458
5459# ADMINISTRATIVE PARAMETERS
5460# -----------------------------------------------------------------------------
5461
5462# TAG: cache_mgr
5463# Email-address of local cache manager who will receive
5464# mail if the cache dies. The default is "webmaster".
5465#Default:
5466# cache_mgr webmaster
5467
5468# TAG: mail_from
5469# From: email-address for mail sent when the cache dies.
5470# The default is to use 'squid@unique_hostname'.
5471#
5472# See also: unique_hostname directive.
5473#Default:
5474# none
5475
5476# TAG: mail_program
5477# Email program used to send mail if the cache dies.
5478# The default is "mail". The specified program must comply
5479# with the standard Unix mail syntax:
5480# mail-program recipient < mailfile
5481#
5482# Optional command line options can be specified.
5483#Default:
5484# mail_program mail
5485
5486# TAG: cache_effective_user
5487# If you start Squid as root, it will change its effective/real
5488# UID/GID to the user specified below. The default is to change
5489# to UID of proxy.
5490# see also; cache_effective_group
5491#Default:
5492# cache_effective_user proxy
5493
5494# TAG: cache_effective_group
5495# Squid sets the GID to the effective user's default group ID
5496# (taken from the password file) and supplementary group list
5497# from the groups membership.
5498#
5499# If you want Squid to run with a specific GID regardless of
5500# the group memberships of the effective user then set this
5501# to the group (or GID) you want Squid to run as. When set
5502# all other group privileges of the effective user are ignored
5503# and only this GID is effective. If Squid is not started as
5504# root the user starting Squid MUST be member of the specified
5505# group.
5506#
5507# This option is not recommended by the Squid Team.
5508# Our preference is for administrators to configure a secure
5509# user account for squid with UID/GID matching system policies.
5510#Default:
5511# Use system group memberships of the cache_effective_user account
5512
5513# TAG: httpd_suppress_version_string on|off
5514# Suppress Squid version string info in HTTP headers and HTML error pages.
5515#Default:
5516# httpd_suppress_version_string off
5517
5518# TAG: visible_hostname
5519# If you want to present a special hostname in error messages, etc,
5520# define this. Otherwise, the return value of gethostname()
5521# will be used. If you have multiple caches in a cluster and
5522# get errors about IP-forwarding you must set them to have individual
5523# names with this setting.
5524#Default:
5525# Automatically detect the system host name
5526
5527# TAG: unique_hostname
5528# If you want to have multiple machines with the same
5529# 'visible_hostname' you must give each machine a different
5530# 'unique_hostname' so forwarding loops can be detected.
5531#Default:
5532# Copy the value from visible_hostname
5533
5534# TAG: hostname_aliases
5535# A list of other DNS names your cache has.
5536#Default:
5537# none
5538
5539# TAG: umask
5540# Minimum umask which should be enforced while the proxy
5541# is running, in addition to the umask set at startup.
5542#
5543# For a traditional octal representation of umasks, start
5544# your value with 0.
5545#Default:
5546# umask 027
5547
5548# OPTIONS FOR THE CACHE REGISTRATION SERVICE
5549# -----------------------------------------------------------------------------
5550#
5551# This section contains parameters for the (optional) cache
5552# announcement service. This service is provided to help
5553# cache administrators locate one another in order to join or
5554# create cache hierarchies.
5555#
5556# An 'announcement' message is sent (via UDP) to the registration
5557# service by Squid. By default, the announcement message is NOT
5558# SENT unless you enable it with 'announce_period' below.
5559#
5560# The announcement message includes your hostname, plus the
5561# following information from this configuration file:
5562#
5563# http_port
5564# icp_port
5565# cache_mgr
5566#
5567# All current information is processed regularly and made
5568# available on the Web at http://www.ircache.net/Cache/Tracker/.
5569
5570# TAG: announce_period
5571# This is how frequently to send cache announcements.
5572#
5573# To enable announcing your cache, just set an announce period.
5574#
5575# Example:
5576# announce_period 1 day
5577#Default:
5578# Announcement messages disabled.
5579
5580# TAG: announce_host
5581# Set the hostname where announce registration messages will be sent.
5582#
5583# See also announce_port and announce_file
5584#Default:
5585# announce_host tracker.ircache.net
5586
5587# TAG: announce_file
5588# The contents of this file will be included in the announce
5589# registration messages.
5590#Default:
5591# none
5592
5593# TAG: announce_port
5594# Set the port where announce registration messages will be sent.
5595#
5596# See also announce_host and announce_file
5597#Default:
5598# announce_port 3131
5599
5600# HTTPD-ACCELERATOR OPTIONS
5601# -----------------------------------------------------------------------------
5602
5603# TAG: httpd_accel_surrogate_id
5604# Surrogates (http://www.esi.org/architecture_spec_1.0.html)
5605# need an identification token to allow control targeting. Because
5606# a farm of surrogates may all perform the same tasks, they may share
5607# an identification token.
5608#Default:
5609# visible_hostname is used if no specific ID is set.
5610
5611# TAG: http_accel_surrogate_remote on|off
5612# Remote surrogates (such as those in a CDN) honour the header
5613# "Surrogate-Control: no-store-remote".
5614#
5615# Set this to on to have squid behave as a remote surrogate.
5616#Default:
5617# http_accel_surrogate_remote off
5618
5619# TAG: esi_parser libxml2|expat|custom
5620# Note: This option is only available if Squid is rebuilt with the
5621# --enable-esi
5622#
5623# ESI markup is not strictly XML compatible. The custom ESI parser
5624# will give higher performance, but cannot handle non ASCII character
5625# encodings.
5626#Default:
5627# esi_parser custom
5628
5629# DELAY POOL PARAMETERS
5630# -----------------------------------------------------------------------------
5631
5632# TAG: delay_pools
5633# Note: This option is only available if Squid is rebuilt with the
5634# --enable-delay-pools
5635#
5636# This represents the number of delay pools to be used. For example,
5637# if you have one class 2 delay pool and one class 3 delays pool, you
5638# have a total of 2 delay pools.
5639#
5640# See also delay_parameters, delay_class, delay_access for pool
5641# configuration details.
5642#Default:
5643# delay_pools 0
5644
5645# TAG: delay_class
5646# Note: This option is only available if Squid is rebuilt with the
5647# --enable-delay-pools
5648#
5649# This defines the class of each delay pool. There must be exactly one
5650# delay_class line for each delay pool. For example, to define two
5651# delay pools, one of class 2 and one of class 3, the settings above
5652# and here would be:
5653#
5654# Example:
5655# delay_pools 4 # 4 delay pools
5656# delay_class 1 2 # pool 1 is a class 2 pool
5657# delay_class 2 3 # pool 2 is a class 3 pool
5658# delay_class 3 4 # pool 3 is a class 4 pool
5659# delay_class 4 5 # pool 4 is a class 5 pool
5660#
5661# The delay pool classes are:
5662#
5663# class 1 Everything is limited by a single aggregate
5664# bucket.
5665#
5666# class 2 Everything is limited by a single aggregate
5667# bucket as well as an "individual" bucket chosen
5668# from bits 25 through 32 of the IPv4 address.
5669#
5670# class 3 Everything is limited by a single aggregate
5671# bucket as well as a "network" bucket chosen
5672# from bits 17 through 24 of the IP address and a
5673# "individual" bucket chosen from bits 17 through
5674# 32 of the IPv4 address.
5675#
5676# class 4 Everything in a class 3 delay pool, with an
5677# additional limit on a per user basis. This
5678# only takes effect if the username is established
5679# in advance - by forcing authentication in your
5680# http_access rules.
5681#
5682# class 5 Requests are grouped according their tag (see
5683# external_acl's tag= reply).
5684#
5685#
5686# Each pool also requires a delay_parameters directive to configure the pool size
5687# and speed limits used whenever the pool is applied to a request. Along with
5688# a set of delay_access directives to determine when it is used.
5689#
5690# NOTE: If an IP address is a.b.c.d
5691# -> bits 25 through 32 are "d"
5692# -> bits 17 through 24 are "c"
5693# -> bits 17 through 32 are "c * 256 + d"
5694#
5695# NOTE-2: Due to the use of bitmasks in class 2,3,4 pools they only apply to
5696# IPv4 traffic. Class 1 and 5 pools may be used with IPv6 traffic.
5697#
5698# This clause only supports fast acl types.
5699# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5700#
5701# See also delay_parameters and delay_access.
5702#Default:
5703# none
5704
5705# TAG: delay_access
5706# Note: This option is only available if Squid is rebuilt with the
5707# --enable-delay-pools
5708#
5709# This is used to determine which delay pool a request falls into.
5710#
5711# delay_access is sorted per pool and the matching starts with pool 1,
5712# then pool 2, ..., and finally pool N. The first delay pool where the
5713# request is allowed is selected for the request. If it does not allow
5714# the request to any pool then the request is not delayed (default).
5715#
5716# For example, if you want some_big_clients in delay
5717# pool 1 and lotsa_little_clients in delay pool 2:
5718#
5719# delay_access 1 allow some_big_clients
5720# delay_access 1 deny all
5721# delay_access 2 allow lotsa_little_clients
5722# delay_access 2 deny all
5723# delay_access 3 allow authenticated_clients
5724#
5725# See also delay_parameters and delay_class.
5726#
5727#Default:
5728# Deny using the pool, unless allow rules exist in squid.conf for the pool.
5729
5730# TAG: delay_parameters
5731# Note: This option is only available if Squid is rebuilt with the
5732# --enable-delay-pools
5733#
5734# This defines the parameters for a delay pool. Each delay pool has
5735# a number of "buckets" associated with it, as explained in the
5736# description of delay_class.
5737#
5738# For a class 1 delay pool, the syntax is:
5739# delay_class pool 1
5740# delay_parameters pool aggregate
5741#
5742# For a class 2 delay pool:
5743# delay_class pool 2
5744# delay_parameters pool aggregate individual
5745#
5746# For a class 3 delay pool:
5747# delay_class pool 3
5748# delay_parameters pool aggregate network individual
5749#
5750# For a class 4 delay pool:
5751# delay_class pool 4
5752# delay_parameters pool aggregate network individual user
5753#
5754# For a class 5 delay pool:
5755# delay_class pool 5
5756# delay_parameters pool tagrate
5757#
5758# The option variables are:
5759#
5760# pool a pool number - ie, a number between 1 and the
5761# number specified in delay_pools as used in
5762# delay_class lines.
5763#
5764# aggregate the speed limit parameters for the aggregate bucket
5765# (class 1, 2, 3).
5766#
5767# individual the speed limit parameters for the individual
5768# buckets (class 2, 3).
5769#
5770# network the speed limit parameters for the network buckets
5771# (class 3).
5772#
5773# user the speed limit parameters for the user buckets
5774# (class 4).
5775#
5776# tagrate the speed limit parameters for the tag buckets
5777# (class 5).
5778#
5779# A pair of delay parameters is written restore/maximum, where restore is
5780# the number of bytes (not bits - modem and network speeds are usually
5781# quoted in bits) per second placed into the bucket, and maximum is the
5782# maximum number of bytes which can be in the bucket at any time.
5783#
5784# There must be one delay_parameters line for each delay pool.
5785#
5786#
5787# For example, if delay pool number 1 is a class 2 delay pool as in the
5788# above example, and is being used to strictly limit each host to 64Kbit/sec
5789# (plus overheads), with no overall limit, the line is:
5790#
5791# delay_parameters 1 none 8000/8000
5792#
5793# Note that 8 x 8K Byte/sec -> 64K bit/sec.
5794#
5795# Note that the word 'none' is used to represent no limit.
5796#
5797#
5798# And, if delay pool number 2 is a class 3 delay pool as in the above
5799# example, and you want to limit it to a total of 256Kbit/sec (strict limit)
5800# with each 8-bit network permitted 64Kbit/sec (strict limit) and each
5801# individual host permitted 4800bit/sec with a bucket maximum size of 64Kbits
5802# to permit a decent web page to be downloaded at a decent speed
5803# (if the network is not being limited due to overuse) but slow down
5804# large downloads more significantly:
5805#
5806# delay_parameters 2 32000/32000 8000/8000 600/8000
5807#
5808# Note that 8 x 32K Byte/sec -> 256K bit/sec.
5809# 8 x 8K Byte/sec -> 64K bit/sec.
5810# 8 x 600 Byte/sec -> 4800 bit/sec.
5811#
5812#
5813# Finally, for a class 4 delay pool as in the example - each user will
5814# be limited to 128Kbits/sec no matter how many workstations they are logged into.:
5815#
5816# delay_parameters 4 32000/32000 8000/8000 600/64000 16000/16000
5817#
5818#
5819# See also delay_class and delay_access.
5820#
5821#Default:
5822# none
5823
5824# TAG: delay_initial_bucket_level (percent, 0-100)
5825# Note: This option is only available if Squid is rebuilt with the
5826# --enable-delay-pools
5827#
5828# The initial bucket percentage is used to determine how much is put
5829# in each bucket when squid starts, is reconfigured, or first notices
5830# a host accessing it (in class 2 and class 3, individual hosts and
5831# networks only have buckets associated with them once they have been
5832# "seen" by squid).
5833#Default:
5834# delay_initial_bucket_level 50
5835
5836# CLIENT DELAY POOL PARAMETERS
5837# -----------------------------------------------------------------------------
5838
5839# TAG: client_delay_pools
5840# Note: This option is only available if Squid is rebuilt with the
5841# --enable-delay-pools
5842#
5843# This option specifies the number of client delay pools used. It must
5844# preceed other client_delay_* options.
5845#
5846# Example:
5847# client_delay_pools 2
5848#
5849# See also client_delay_parameters and client_delay_access.
5850#Default:
5851# client_delay_pools 0
5852
5853# TAG: client_delay_initial_bucket_level (percent, 0-no_limit)
5854# Note: This option is only available if Squid is rebuilt with the
5855# --enable-delay-pools
5856#
5857# This option determines the initial bucket size as a percentage of
5858# max_bucket_size from client_delay_parameters. Buckets are created
5859# at the time of the "first" connection from the matching IP. Idle
5860# buckets are periodically deleted up.
5861#
5862# You can specify more than 100 percent but note that such "oversized"
5863# buckets are not refilled until their size goes down to max_bucket_size
5864# from client_delay_parameters.
5865#
5866# Example:
5867# client_delay_initial_bucket_level 50
5868#Default:
5869# client_delay_initial_bucket_level 50
5870
5871# TAG: client_delay_parameters
5872# Note: This option is only available if Squid is rebuilt with the
5873# --enable-delay-pools
5874#
5875#
5876# This option configures client-side bandwidth limits using the
5877# following format:
5878#
5879# client_delay_parameters pool speed_limit max_bucket_size
5880#
5881# pool is an integer ID used for client_delay_access matching.
5882#
5883# speed_limit is bytes added to the bucket per second.
5884#
5885# max_bucket_size is the maximum size of a bucket, enforced after any
5886# speed_limit additions.
5887#
5888# Please see the delay_parameters option for more information and
5889# examples.
5890#
5891# Example:
5892# client_delay_parameters 1 1024 2048
5893# client_delay_parameters 2 51200 16384
5894#
5895# See also client_delay_access.
5896#
5897#Default:
5898# none
5899
5900# TAG: client_delay_access
5901# Note: This option is only available if Squid is rebuilt with the
5902# --enable-delay-pools
5903#
5904# This option determines the client-side delay pool for the
5905# request:
5906#
5907# client_delay_access pool_ID allow|deny acl_name
5908#
5909# All client_delay_access options are checked in their pool ID
5910# order, starting with pool 1. The first checked pool with allowed
5911# request is selected for the request. If no ACL matches or there
5912# are no client_delay_access options, the request bandwidth is not
5913# limited.
5914#
5915# The ACL-selected pool is then used to find the
5916# client_delay_parameters for the request. Client-side pools are
5917# not used to aggregate clients. Clients are always aggregated
5918# based on their source IP addresses (one bucket per source IP).
5919#
5920# This clause only supports fast acl types.
5921# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5922# Additionally, only the client TCP connection details are available.
5923# ACLs testing HTTP properties will not work.
5924#
5925# Please see delay_access for more examples.
5926#
5927# Example:
5928# client_delay_access 1 allow low_rate_network
5929# client_delay_access 2 allow vips_network
5930#
5931#
5932# See also client_delay_parameters and client_delay_pools.
5933#Default:
5934# Deny use of the pool, unless allow rules exist in squid.conf for the pool.
5935
5936# WCCPv1 AND WCCPv2 CONFIGURATION OPTIONS
5937# -----------------------------------------------------------------------------
5938
5939# TAG: wccp_router
5940# Use this option to define your WCCP ``home'' router for
5941# Squid.
5942#
5943# wccp_router supports a single WCCP(v1) router
5944#
5945# wccp2_router supports multiple WCCPv2 routers
5946#
5947# only one of the two may be used at the same time and defines
5948# which version of WCCP to use.
5949#Default:
5950# WCCP disabled.
5951
5952# TAG: wccp2_router
5953# Use this option to define your WCCP ``home'' router for
5954# Squid.
5955#
5956# wccp_router supports a single WCCP(v1) router
5957#
5958# wccp2_router supports multiple WCCPv2 routers
5959#
5960# only one of the two may be used at the same time and defines
5961# which version of WCCP to use.
5962#Default:
5963# WCCPv2 disabled.
5964
5965# TAG: wccp_version
5966# This directive is only relevant if you need to set up WCCP(v1)
5967# to some very old and end-of-life Cisco routers. In all other
5968# setups it must be left unset or at the default setting.
5969# It defines an internal version in the WCCP(v1) protocol,
5970# with version 4 being the officially documented protocol.
5971#
5972# According to some users, Cisco IOS 11.2 and earlier only
5973# support WCCP version 3. If you're using that or an earlier
5974# version of IOS, you may need to change this value to 3, otherwise
5975# do not specify this parameter.
5976#Default:
5977# wccp_version 4
5978
5979# TAG: wccp2_rebuild_wait
5980# If this is enabled Squid will wait for the cache dir rebuild to finish
5981# before sending the first wccp2 HereIAm packet
5982#Default:
5983# wccp2_rebuild_wait on
5984
5985# TAG: wccp2_forwarding_method
5986# WCCP2 allows the setting of forwarding methods between the
5987# router/switch and the cache. Valid values are as follows:
5988#
5989# gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
5990# l2 - L2 redirect (forward the packet using Layer 2/MAC rewriting)
5991#
5992# Currently (as of IOS 12.4) cisco routers only support GRE.
5993# Cisco switches only support the L2 redirect assignment method.
5994#Default:
5995# wccp2_forwarding_method gre
5996
5997# TAG: wccp2_return_method
5998# WCCP2 allows the setting of return methods between the
5999# router/switch and the cache for packets that the cache
6000# decides not to handle. Valid values are as follows:
6001#
6002# gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
6003# l2 - L2 redirect (forward the packet using Layer 2/MAC rewriting)
6004#
6005# Currently (as of IOS 12.4) cisco routers only support GRE.
6006# Cisco switches only support the L2 redirect assignment.
6007#
6008# If the "ip wccp redirect exclude in" command has been
6009# enabled on the cache interface, then it is still safe for
6010# the proxy server to use a l2 redirect method even if this
6011# option is set to GRE.
6012#Default:
6013# wccp2_return_method gre
6014
6015# TAG: wccp2_assignment_method
6016# WCCP2 allows the setting of methods to assign the WCCP hash
6017# Valid values are as follows:
6018#
6019# hash - Hash assignment
6020# mask - Mask assignment
6021#
6022# As a general rule, cisco routers support the hash assignment method
6023# and cisco switches support the mask assignment method.
6024#Default:
6025# wccp2_assignment_method hash
6026
6027# TAG: wccp2_service
6028# WCCP2 allows for multiple traffic services. There are two
6029# types: "standard" and "dynamic". The standard type defines
6030# one service id - http (id 0). The dynamic service ids can be from
6031# 51 to 255 inclusive. In order to use a dynamic service id
6032# one must define the type of traffic to be redirected; this is done
6033# using the wccp2_service_info option.
6034#
6035# The "standard" type does not require a wccp2_service_info option,
6036# just specifying the service id will suffice.
6037#
6038# MD5 service authentication can be enabled by adding
6039# "password=<password>" to the end of this service declaration.
6040#
6041# Examples:
6042#
6043# wccp2_service standard 0 # for the 'web-cache' standard service
6044# wccp2_service dynamic 80 # a dynamic service type which will be
6045# # fleshed out with subsequent options.
6046# wccp2_service standard 0 password=foo
6047#Default:
6048# Use the 'web-cache' standard service.
6049
6050# TAG: wccp2_service_info
6051# Dynamic WCCPv2 services require further information to define the
6052# traffic you wish to have diverted.
6053#
6054# The format is:
6055#
6056# wccp2_service_info <id> protocol=<protocol> flags=<flag>,<flag>..
6057# priority=<priority> ports=<port>,<port>..
6058#
6059# The relevant WCCPv2 flags:
6060# + src_ip_hash, dst_ip_hash
6061# + source_port_hash, dst_port_hash
6062# + src_ip_alt_hash, dst_ip_alt_hash
6063# + src_port_alt_hash, dst_port_alt_hash
6064# + ports_source
6065#
6066# The port list can be one to eight entries.
6067#
6068# Example:
6069#
6070# wccp2_service_info 80 protocol=tcp flags=src_ip_hash,ports_source
6071# priority=240 ports=80
6072#
6073# Note: the service id must have been defined by a previous
6074# 'wccp2_service dynamic <id>' entry.
6075#Default:
6076# none
6077
6078# TAG: wccp2_weight
6079# Each cache server gets assigned a set of the destination
6080# hash proportional to their weight.
6081#Default:
6082# wccp2_weight 10000
6083
6084# TAG: wccp_address
6085# Use this option if you require WCCPv2 to use a specific
6086# interface address.
6087#
6088# The default behavior is to not bind to any specific address.
6089#Default:
6090# Address selected by the operating system.
6091
6092# TAG: wccp2_address
6093# Use this option if you require WCCP to use a specific
6094# interface address.
6095#
6096# The default behavior is to not bind to any specific address.
6097#Default:
6098# Address selected by the operating system.
6099
6100# PERSISTENT CONNECTION HANDLING
6101# -----------------------------------------------------------------------------
6102#
6103# Also see "pconn_timeout" in the TIMEOUTS section
6104
6105# TAG: client_persistent_connections
6106# Persistent connection support for clients.
6107# Squid uses persistent connections (when allowed). You can use
6108# this option to disable persistent connections with clients.
6109#Default:
6110# client_persistent_connections on
6111
6112# TAG: server_persistent_connections
6113# Persistent connection support for servers.
6114# Squid uses persistent connections (when allowed). You can use
6115# this option to disable persistent connections with servers.
6116#Default:
6117# server_persistent_connections on
6118
6119# TAG: persistent_connection_after_error
6120# With this directive the use of persistent connections after
6121# HTTP errors can be disabled. Useful if you have clients
6122# who fail to handle errors on persistent connections proper.
6123#Default:
6124# persistent_connection_after_error on
6125
6126# TAG: detect_broken_pconn
6127# Some servers have been found to incorrectly signal the use
6128# of HTTP/1.0 persistent connections even on replies not
6129# compatible, causing significant delays. This server problem
6130# has mostly been seen on redirects.
6131#
6132# By enabling this directive Squid attempts to detect such
6133# broken replies and automatically assume the reply is finished
6134# after 10 seconds timeout.
6135#Default:
6136# detect_broken_pconn off
6137
6138# CACHE DIGEST OPTIONS
6139# -----------------------------------------------------------------------------
6140
6141# TAG: digest_generation
6142# Note: This option is only available if Squid is rebuilt with the
6143# --enable-cache-digests
6144#
6145# This controls whether the server will generate a Cache Digest
6146# of its contents. By default, Cache Digest generation is
6147# enabled if Squid is compiled with --enable-cache-digests defined.
6148#Default:
6149# digest_generation on
6150
6151# TAG: digest_bits_per_entry
6152# Note: This option is only available if Squid is rebuilt with the
6153# --enable-cache-digests
6154#
6155# This is the number of bits of the server's Cache Digest which
6156# will be associated with the Digest entry for a given HTTP
6157# Method and URL (public key) combination. The default is 5.
6158#Default:
6159# digest_bits_per_entry 5
6160
6161# TAG: digest_rebuild_period (seconds)
6162# Note: This option is only available if Squid is rebuilt with the
6163# --enable-cache-digests
6164#
6165# This is the wait time between Cache Digest rebuilds.
6166#Default:
6167# digest_rebuild_period 1 hour
6168
6169# TAG: digest_rewrite_period (seconds)
6170# Note: This option is only available if Squid is rebuilt with the
6171# --enable-cache-digests
6172#
6173# This is the wait time between Cache Digest writes to
6174# disk.
6175#Default:
6176# digest_rewrite_period 1 hour
6177
6178# TAG: digest_swapout_chunk_size (bytes)
6179# Note: This option is only available if Squid is rebuilt with the
6180# --enable-cache-digests
6181#
6182# This is the number of bytes of the Cache Digest to write to
6183# disk at a time. It defaults to 4096 bytes (4KB), the Squid
6184# default swap page.
6185#Default:
6186# digest_swapout_chunk_size 4096 bytes
6187
6188# TAG: digest_rebuild_chunk_percentage (percent, 0-100)
6189# Note: This option is only available if Squid is rebuilt with the
6190# --enable-cache-digests
6191#
6192# This is the percentage of the Cache Digest to be scanned at a
6193# time. By default it is set to 10% of the Cache Digest.
6194#Default:
6195# digest_rebuild_chunk_percentage 10
6196
6197# SNMP OPTIONS
6198# -----------------------------------------------------------------------------
6199
6200# TAG: snmp_port
6201# The port number where Squid listens for SNMP requests. To enable
6202# SNMP support set this to a suitable port number. Port number
6203# 3401 is often used for the Squid SNMP agent. By default it's
6204# set to "0" (disabled)
6205#
6206# Example:
6207# snmp_port 3401
6208#Default:
6209# SNMP disabled.
6210
6211# TAG: snmp_access
6212# Allowing or denying access to the SNMP port.
6213#
6214# All access to the agent is denied by default.
6215# usage:
6216#
6217# snmp_access allow|deny [!]aclname ...
6218#
6219# This clause only supports fast acl types.
6220# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
6221#
6222#Example:
6223# snmp_access allow snmppublic localhost
6224# snmp_access deny all
6225#Default:
6226# Deny, unless rules exist in squid.conf.
6227
6228# TAG: snmp_incoming_address
6229# Just like 'udp_incoming_address', but for the SNMP port.
6230#
6231# snmp_incoming_address is used for the SNMP socket receiving
6232# messages from SNMP agents.
6233#
6234# The default snmp_incoming_address is to listen on all
6235# available network interfaces.
6236#Default:
6237# Accept SNMP packets from all machine interfaces.
6238
6239# TAG: snmp_outgoing_address
6240# Just like 'udp_outgoing_address', but for the SNMP port.
6241#
6242# snmp_outgoing_address is used for SNMP packets returned to SNMP
6243# agents.
6244#
6245# If snmp_outgoing_address is not set it will use the same socket
6246# as snmp_incoming_address. Only change this if you want to have
6247# SNMP replies sent using another address than where this Squid
6248# listens for SNMP queries.
6249#
6250# NOTE, snmp_incoming_address and snmp_outgoing_address can not have
6251# the same value since they both use the same port.
6252#Default:
6253# Use snmp_incoming_address or an address selected by the operating system.
6254
6255# ICP OPTIONS
6256# -----------------------------------------------------------------------------
6257
6258# TAG: icp_port
6259# The port number where Squid sends and receives ICP queries to
6260# and from neighbor caches. The standard UDP port for ICP is 3130.
6261#
6262# Example:
6263# icp_port 3130
6264#Default:
6265# ICP disabled.
6266
6267# TAG: htcp_port
6268# The port number where Squid sends and receives HTCP queries to
6269# and from neighbor caches. To turn it on you want to set it to
6270# 4827.
6271#
6272# Example:
6273# htcp_port 4827
6274#Default:
6275# HTCP disabled.
6276
6277# TAG: log_icp_queries on|off
6278# If set, ICP queries are logged to access.log. You may wish
6279# do disable this if your ICP load is VERY high to speed things
6280# up or to simplify log analysis.
6281#Default:
6282# log_icp_queries on
6283
6284# TAG: udp_incoming_address
6285# udp_incoming_address is used for UDP packets received from other
6286# caches.
6287#
6288# The default behavior is to not bind to any specific address.
6289#
6290# Only change this if you want to have all UDP queries received on
6291# a specific interface/address.
6292#
6293# NOTE: udp_incoming_address is used by the ICP, HTCP, and DNS
6294# modules. Altering it will affect all of them in the same manner.
6295#
6296# see also; udp_outgoing_address
6297#
6298# NOTE, udp_incoming_address and udp_outgoing_address can not
6299# have the same value since they both use the same port.
6300#Default:
6301# Accept packets from all machine interfaces.
6302
6303# TAG: udp_outgoing_address
6304# udp_outgoing_address is used for UDP packets sent out to other
6305# caches.
6306#
6307# The default behavior is to not bind to any specific address.
6308#
6309# Instead it will use the same socket as udp_incoming_address.
6310# Only change this if you want to have UDP queries sent using another
6311# address than where this Squid listens for UDP queries from other
6312# caches.
6313#
6314# NOTE: udp_outgoing_address is used by the ICP, HTCP, and DNS
6315# modules. Altering it will affect all of them in the same manner.
6316#
6317# see also; udp_incoming_address
6318#
6319# NOTE, udp_incoming_address and udp_outgoing_address can not
6320# have the same value since they both use the same port.
6321#Default:
6322# Use udp_incoming_address or an address selected by the operating system.
6323
6324# TAG: icp_hit_stale on|off
6325# If you want to return ICP_HIT for stale cache objects, set this
6326# option to 'on'. If you have sibling relationships with caches
6327# in other administrative domains, this should be 'off'. If you only
6328# have sibling relationships with caches under your control,
6329# it is probably okay to set this to 'on'.
6330# If set to 'on', your siblings should use the option "allow-miss"
6331# on their cache_peer lines for connecting to you.
6332#Default:
6333# icp_hit_stale off
6334
6335# TAG: minimum_direct_hops
6336# If using the ICMP pinging stuff, do direct fetches for sites
6337# which are no more than this many hops away.
6338#Default:
6339# minimum_direct_hops 4
6340
6341# TAG: minimum_direct_rtt (msec)
6342# If using the ICMP pinging stuff, do direct fetches for sites
6343# which are no more than this many rtt milliseconds away.
6344#Default:
6345# minimum_direct_rtt 400
6346
6347# TAG: netdb_low
6348# The low water mark for the ICMP measurement database.
6349#
6350# Note: high watermark controlled by netdb_high directive.
6351#
6352# These watermarks are counts, not percents. The defaults are
6353# (low) 900 and (high) 1000. When the high water mark is
6354# reached, database entries will be deleted until the low
6355# mark is reached.
6356#Default:
6357# netdb_low 900
6358
6359# TAG: netdb_high
6360# The high water mark for the ICMP measurement database.
6361#
6362# Note: low watermark controlled by netdb_low directive.
6363#
6364# These watermarks are counts, not percents. The defaults are
6365# (low) 900 and (high) 1000. When the high water mark is
6366# reached, database entries will be deleted until the low
6367# mark is reached.
6368#Default:
6369# netdb_high 1000
6370
6371# TAG: netdb_ping_period
6372# The minimum period for measuring a site. There will be at
6373# least this much delay between successive pings to the same
6374# network. The default is five minutes.
6375#Default:
6376# netdb_ping_period 5 minutes
6377
6378# TAG: query_icmp on|off
6379# If you want to ask your peers to include ICMP data in their ICP
6380# replies, enable this option.
6381#
6382# If your peer has configured Squid (during compilation) with
6383# '--enable-icmp' that peer will send ICMP pings to origin server
6384# sites of the URLs it receives. If you enable this option the
6385# ICP replies from that peer will include the ICMP data (if available).
6386# Then, when choosing a parent cache, Squid will choose the parent with
6387# the minimal RTT to the origin server. When this happens, the
6388# hierarchy field of the access.log will be
6389# "CLOSEST_PARENT_MISS". This option is off by default.
6390#Default:
6391# query_icmp off
6392
6393# TAG: test_reachability on|off
6394# When this is 'on', ICP MISS replies will be ICP_MISS_NOFETCH
6395# instead of ICP_MISS if the target host is NOT in the ICMP
6396# database, or has a zero RTT.
6397#Default:
6398# test_reachability off
6399
6400# TAG: icp_query_timeout (msec)
6401# Normally Squid will automatically determine an optimal ICP
6402# query timeout value based on the round-trip-time of recent ICP
6403# queries. If you want to override the value determined by
6404# Squid, set this 'icp_query_timeout' to a non-zero value. This
6405# value is specified in MILLISECONDS, so, to use a 2-second
6406# timeout (the old default), you would write:
6407#
6408# icp_query_timeout 2000
6409#Default:
6410# Dynamic detection.
6411
6412# TAG: maximum_icp_query_timeout (msec)
6413# Normally the ICP query timeout is determined dynamically. But
6414# sometimes it can lead to very large values (say 5 seconds).
6415# Use this option to put an upper limit on the dynamic timeout
6416# value. Do NOT use this option to always use a fixed (instead
6417# of a dynamic) timeout value. To set a fixed timeout see the
6418# 'icp_query_timeout' directive.
6419#Default:
6420# maximum_icp_query_timeout 2000
6421
6422# TAG: minimum_icp_query_timeout (msec)
6423# Normally the ICP query timeout is determined dynamically. But
6424# sometimes it can lead to very small timeouts, even lower than
6425# the normal latency variance on your link due to traffic.
6426# Use this option to put an lower limit on the dynamic timeout
6427# value. Do NOT use this option to always use a fixed (instead
6428# of a dynamic) timeout value. To set a fixed timeout see the
6429# 'icp_query_timeout' directive.
6430#Default:
6431# minimum_icp_query_timeout 5
6432
6433# TAG: background_ping_rate time-units
6434# Controls how often the ICP pings are sent to siblings that
6435# have background-ping set.
6436#Default:
6437# background_ping_rate 10 seconds
6438
6439# MULTICAST ICP OPTIONS
6440# -----------------------------------------------------------------------------
6441
6442# TAG: mcast_groups
6443# This tag specifies a list of multicast groups which your server
6444# should join to receive multicasted ICP queries.
6445#
6446# NOTE! Be very careful what you put here! Be sure you
6447# understand the difference between an ICP _query_ and an ICP
6448# _reply_. This option is to be set only if you want to RECEIVE
6449# multicast queries. Do NOT set this option to SEND multicast
6450# ICP (use cache_peer for that). ICP replies are always sent via
6451# unicast, so this option does not affect whether or not you will
6452# receive replies from multicast group members.
6453#
6454# You must be very careful to NOT use a multicast address which
6455# is already in use by another group of caches.
6456#
6457# If you are unsure about multicast, please read the Multicast
6458# chapter in the Squid FAQ (http://www.squid-cache.org/FAQ/).
6459#
6460# Usage: mcast_groups 239.128.16.128 224.0.1.20
6461#
6462# By default, Squid doesn't listen on any multicast groups.
6463#Default:
6464# none
6465
6466# TAG: mcast_miss_addr
6467# Note: This option is only available if Squid is rebuilt with the
6468# -DMULTICAST_MISS_STREAM define
6469#
6470# If you enable this option, every "cache miss" URL will
6471# be sent out on the specified multicast address.
6472#
6473# Do not enable this option unless you are are absolutely
6474# certain you understand what you are doing.
6475#Default:
6476# disabled.
6477
6478# TAG: mcast_miss_ttl
6479# Note: This option is only available if Squid is rebuilt with the
6480# -DMULTICAST_MISS_STREAM define
6481#
6482# This is the time-to-live value for packets multicasted
6483# when multicasting off cache miss URLs is enabled. By
6484# default this is set to 'site scope', i.e. 16.
6485#Default:
6486# mcast_miss_ttl 16
6487
6488# TAG: mcast_miss_port
6489# Note: This option is only available if Squid is rebuilt with the
6490# -DMULTICAST_MISS_STREAM define
6491#
6492# This is the port number to be used in conjunction with
6493# 'mcast_miss_addr'.
6494#Default:
6495# mcast_miss_port 3135
6496
6497# TAG: mcast_miss_encode_key
6498# Note: This option is only available if Squid is rebuilt with the
6499# -DMULTICAST_MISS_STREAM define
6500#
6501# The URLs that are sent in the multicast miss stream are
6502# encrypted. This is the encryption key.
6503#Default:
6504# mcast_miss_encode_key XXXXXXXXXXXXXXXX
6505
6506# TAG: mcast_icp_query_timeout (msec)
6507# For multicast peers, Squid regularly sends out ICP "probes" to
6508# count how many other peers are listening on the given multicast
6509# address. This value specifies how long Squid should wait to
6510# count all the replies. The default is 2000 msec, or 2
6511# seconds.
6512#Default:
6513# mcast_icp_query_timeout 2000
6514
6515# INTERNAL ICON OPTIONS
6516# -----------------------------------------------------------------------------
6517
6518# TAG: icon_directory
6519# Where the icons are stored. These are normally kept in
6520# /usr/share/squid/icons
6521#Default:
6522# icon_directory /usr/share/squid/icons
6523
6524# TAG: global_internal_static
6525# This directive controls is Squid should intercept all requests for
6526# /squid-internal-static/ no matter which host the URL is requesting
6527# (default on setting), or if nothing special should be done for
6528# such URLs (off setting). The purpose of this directive is to make
6529# icons etc work better in complex cache hierarchies where it may
6530# not always be possible for all corners in the cache mesh to reach
6531# the server generating a directory listing.
6532#Default:
6533# global_internal_static on
6534
6535# TAG: short_icon_urls
6536# If this is enabled Squid will use short URLs for icons.
6537# If disabled it will revert to the old behavior of including
6538# it's own name and port in the URL.
6539#
6540# If you run a complex cache hierarchy with a mix of Squid and
6541# other proxies you may need to disable this directive.
6542#Default:
6543# short_icon_urls on
6544
6545# ERROR PAGE OPTIONS
6546# -----------------------------------------------------------------------------
6547
6548# TAG: error_directory
6549# If you wish to create your own versions of the default
6550# error files to customize them to suit your company copy
6551# the error/template files to another directory and point
6552# this tag at them.
6553#
6554# WARNING: This option will disable multi-language support
6555# on error pages if used.
6556#
6557# The squid developers are interested in making squid available in
6558# a wide variety of languages. If you are making translations for a
6559# language that Squid does not currently provide please consider
6560# contributing your translation back to the project.
6561# http://wiki.squid-cache.org/Translations
6562#
6563# The squid developers working on translations are happy to supply drop-in
6564# translated error files in exchange for any new language contributions.
6565#Default:
6566# Send error pages in the clients preferred language
6567
6568# TAG: error_default_language
6569# Set the default language which squid will send error pages in
6570# if no existing translation matches the clients language
6571# preferences.
6572#
6573# If unset (default) generic English will be used.
6574#
6575# The squid developers are interested in making squid available in
6576# a wide variety of languages. If you are interested in making
6577# translations for any language see the squid wiki for details.
6578# http://wiki.squid-cache.org/Translations
6579#Default:
6580# Generate English language pages.
6581
6582# TAG: error_log_languages
6583# Log to cache.log what languages users are attempting to
6584# auto-negotiate for translations.
6585#
6586# Successful negotiations are not logged. Only failures
6587# have meaning to indicate that Squid may need an upgrade
6588# of its error page translations.
6589#Default:
6590# error_log_languages on
6591
6592# TAG: err_page_stylesheet
6593# CSS Stylesheet to pattern the display of Squid default error pages.
6594#
6595# For information on CSS see http://www.w3.org/Style/CSS/
6596#Default:
6597# err_page_stylesheet /etc/squid/errorpage.css
6598
6599# TAG: err_html_text
6600# HTML text to include in error messages. Make this a "mailto"
6601# URL to your admin address, or maybe just a link to your
6602# organizations Web page.
6603#
6604# To include this in your error messages, you must rewrite
6605# the error template files (found in the "errors" directory).
6606# Wherever you want the 'err_html_text' line to appear,
6607# insert a %L tag in the error template file.
6608#Default:
6609# none
6610
6611# TAG: email_err_data on|off
6612# If enabled, information about the occurred error will be
6613# included in the mailto links of the ERR pages (if %W is set)
6614# so that the email body contains the data.
6615# Syntax is <A HREF="mailto:%w%W">%w</A>
6616#Default:
6617# email_err_data on
6618
6619# TAG: deny_info
6620# Usage: deny_info err_page_name acl
6621# or deny_info http://... acl
6622# or deny_info TCP_RESET acl
6623#
6624# This can be used to return a ERR_ page for requests which
6625# do not pass the 'http_access' rules. Squid remembers the last
6626# acl it evaluated in http_access, and if a 'deny_info' line exists
6627# for that ACL Squid returns a corresponding error page.
6628#
6629# The acl is typically the last acl on the http_access deny line which
6630# denied access. The exceptions to this rule are:
6631# - When Squid needs to request authentication credentials. It's then
6632# the first authentication related acl encountered
6633# - When none of the http_access lines matches. It's then the last
6634# acl processed on the last http_access line.
6635# - When the decision to deny access was made by an adaptation service,
6636# the acl name is the corresponding eCAP or ICAP service_name.
6637#
6638# NP: If providing your own custom error pages with error_directory
6639# you may also specify them by your custom file name:
6640# Example: deny_info ERR_CUSTOM_ACCESS_DENIED bad_guys
6641#
6642# By defaut Squid will send "403 Forbidden". A different 4xx or 5xx
6643# may be specified by prefixing the file name with the code and a colon.
6644# e.g. 404:ERR_CUSTOM_ACCESS_DENIED
6645#
6646# Alternatively you can tell Squid to reset the TCP connection
6647# by specifying TCP_RESET.
6648#
6649# Or you can specify an error URL or URL pattern. The browsers will
6650# get redirected to the specified URL after formatting tags have
6651# been replaced. Redirect will be done with 302 or 307 according to
6652# HTTP/1.1 specs. A different 3xx code may be specified by prefixing
6653# the URL. e.g. 303:http://example.com/
6654#
6655# URL FORMAT TAGS:
6656# %a - username (if available. Password NOT included)
6657# %B - FTP path URL
6658# %e - Error number
6659# %E - Error description
6660# %h - Squid hostname
6661# %H - Request domain name
6662# %i - Client IP Address
6663# %M - Request Method
6664# %o - Message result from external ACL helper
6665# %p - Request Port number
6666# %P - Request Protocol name
6667# %R - Request URL path
6668# %T - Timestamp in RFC 1123 format
6669# %U - Full canonical URL from client
6670# (HTTPS URLs terminate with *)
6671# %u - Full canonical URL from client
6672# %w - Admin email from squid.conf
6673# %x - Error name
6674# %% - Literal percent (%) code
6675#
6676#Default:
6677# none
6678
6679# OPTIONS INFLUENCING REQUEST FORWARDING
6680# -----------------------------------------------------------------------------
6681
6682# TAG: nonhierarchical_direct
6683# By default, Squid will send any non-hierarchical requests
6684# (not cacheable request type) direct to origin servers.
6685#
6686# When this is set to "off", Squid will prefer to send these
6687# requests to parents.
6688#
6689# Note that in most configurations, by turning this off you will only
6690# add latency to these request without any improvement in global hit
6691# ratio.
6692#
6693# This option only sets a preference. If the parent is unavailable a
6694# direct connection to the origin server may still be attempted. To
6695# completely prevent direct connections use never_direct.
6696#Default:
6697# nonhierarchical_direct on
6698
6699# TAG: prefer_direct
6700# Normally Squid tries to use parents for most requests. If you for some
6701# reason like it to first try going direct and only use a parent if
6702# going direct fails set this to on.
6703#
6704# By combining nonhierarchical_direct off and prefer_direct on you
6705# can set up Squid to use a parent as a backup path if going direct
6706# fails.
6707#
6708# Note: If you want Squid to use parents for all requests see
6709# the never_direct directive. prefer_direct only modifies how Squid
6710# acts on cacheable requests.
6711#Default:
6712# prefer_direct off
6713
6714# TAG: cache_miss_revalidate on|off
6715# RFC 7232 defines a conditional request mechanism to prevent
6716# response objects being unnecessarily transferred over the network.
6717# If that mechanism is used by the client and a cache MISS occurs
6718# it can prevent new cache entries being created.
6719#
6720# This option determines whether Squid on cache MISS will pass the
6721# client revalidation request to the server or tries to fetch new
6722# content for caching. It can be useful while the cache is mostly
6723# empty to more quickly have the cache populated by generating
6724# non-conditional GETs.
6725#
6726# When set to 'on' (default), Squid will pass all client If-* headers
6727# to the server. This permits server responses without a cacheable
6728# payload to be delivered and on MISS no new cache entry is created.
6729#
6730# When set to 'off' and if the request is cacheable, Squid will
6731# remove the clients If-Modified-Since and If-None-Match headers from
6732# the request sent to the server. This requests a 200 status response
6733# from the server to create a new cache entry with.
6734#Default:
6735# cache_miss_revalidate on
6736
6737# TAG: always_direct
6738# Usage: always_direct allow|deny [!]aclname ...
6739#
6740# Here you can use ACL elements to specify requests which should
6741# ALWAYS be forwarded by Squid to the origin servers without using
6742# any peers. For example, to always directly forward requests for
6743# local servers ignoring any parents or siblings you may have use
6744# something like:
6745#
6746# acl local-servers dstdomain my.domain.net
6747# always_direct allow local-servers
6748#
6749# To always forward FTP requests directly, use
6750#
6751# acl FTP proto FTP
6752# always_direct allow FTP
6753#
6754# NOTE: There is a similar, but opposite option named
6755# 'never_direct'. You need to be aware that "always_direct deny
6756# foo" is NOT the same thing as "never_direct allow foo". You
6757# may need to use a deny rule to exclude a more-specific case of
6758# some other rule. Example:
6759#
6760# acl local-external dstdomain external.foo.net
6761# acl local-servers dstdomain .foo.net
6762# always_direct deny local-external
6763# always_direct allow local-servers
6764#
6765# NOTE: If your goal is to make the client forward the request
6766# directly to the origin server bypassing Squid then this needs
6767# to be done in the client configuration. Squid configuration
6768# can only tell Squid how Squid should fetch the object.
6769#
6770# NOTE: This directive is not related to caching. The replies
6771# is cached as usual even if you use always_direct. To not cache
6772# the replies see the 'cache' directive.
6773#
6774# This clause supports both fast and slow acl types.
6775# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
6776#Default:
6777# Prevent any cache_peer being used for this request.
6778
6779# TAG: never_direct
6780# Usage: never_direct allow|deny [!]aclname ...
6781#
6782# never_direct is the opposite of always_direct. Please read
6783# the description for always_direct if you have not already.
6784#
6785# With 'never_direct' you can use ACL elements to specify
6786# requests which should NEVER be forwarded directly to origin
6787# servers. For example, to force the use of a proxy for all
6788# requests, except those in your local domain use something like:
6789#
6790# acl local-servers dstdomain .foo.net
6791# never_direct deny local-servers
6792# never_direct allow all
6793#
6794# or if Squid is inside a firewall and there are local intranet
6795# servers inside the firewall use something like:
6796#
6797# acl local-intranet dstdomain .foo.net
6798# acl local-external dstdomain external.foo.net
6799# always_direct deny local-external
6800# always_direct allow local-intranet
6801# never_direct allow all
6802#
6803# This clause supports both fast and slow acl types.
6804# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
6805#Default:
6806# Allow DNS results to be used for this request.
6807
6808# ADVANCED NETWORKING OPTIONS
6809# -----------------------------------------------------------------------------
6810
6811# TAG: incoming_udp_average
6812# Heavy voodoo here. I can't even believe you are reading this.
6813# Are you crazy? Don't even think about adjusting these unless
6814# you understand the algorithms in comm_select.c first!
6815#Default:
6816# incoming_udp_average 6
6817
6818# TAG: incoming_tcp_average
6819# Heavy voodoo here. I can't even believe you are reading this.
6820# Are you crazy? Don't even think about adjusting these unless
6821# you understand the algorithms in comm_select.c first!
6822#Default:
6823# incoming_tcp_average 4
6824
6825# TAG: incoming_dns_average
6826# Heavy voodoo here. I can't even believe you are reading this.
6827# Are you crazy? Don't even think about adjusting these unless
6828# you understand the algorithms in comm_select.c first!
6829#Default:
6830# incoming_dns_average 4
6831
6832# TAG: min_udp_poll_cnt
6833# Heavy voodoo here. I can't even believe you are reading this.
6834# Are you crazy? Don't even think about adjusting these unless
6835# you understand the algorithms in comm_select.c first!
6836#Default:
6837# min_udp_poll_cnt 8
6838
6839# TAG: min_dns_poll_cnt
6840# Heavy voodoo here. I can't even believe you are reading this.
6841# Are you crazy? Don't even think about adjusting these unless
6842# you understand the algorithms in comm_select.c first!
6843#Default:
6844# min_dns_poll_cnt 8
6845
6846# TAG: min_tcp_poll_cnt
6847# Heavy voodoo here. I can't even believe you are reading this.
6848# Are you crazy? Don't even think about adjusting these unless
6849# you understand the algorithms in comm_select.c first!
6850#Default:
6851# min_tcp_poll_cnt 8
6852
6853# TAG: accept_filter
6854# FreeBSD:
6855#
6856# The name of an accept(2) filter to install on Squid's
6857# listen socket(s). This feature is perhaps specific to
6858# FreeBSD and requires support in the kernel.
6859#
6860# The 'httpready' filter delays delivering new connections
6861# to Squid until a full HTTP request has been received.
6862# See the accf_http(9) man page for details.
6863#
6864# The 'dataready' filter delays delivering new connections
6865# to Squid until there is some data to process.
6866# See the accf_dataready(9) man page for details.
6867#
6868# Linux:
6869#
6870# The 'data' filter delays delivering of new connections
6871# to Squid until there is some data to process by TCP_ACCEPT_DEFER.
6872# You may optionally specify a number of seconds to wait by
6873# 'data=N' where N is the number of seconds. Defaults to 30
6874# if not specified. See the tcp(7) man page for details.
6875#EXAMPLE:
6876## FreeBSD
6877#accept_filter httpready
6878## Linux
6879#accept_filter data
6880#Default:
6881# none
6882
6883# TAG: client_ip_max_connections
6884# Set an absolute limit on the number of connections a single
6885# client IP can use. Any more than this and Squid will begin to drop
6886# new connections from the client until it closes some links.
6887#
6888# Note that this is a global limit. It affects all HTTP, HTCP, Gopher and FTP
6889# connections from the client. For finer control use the ACL access controls.
6890#
6891# Requires client_db to be enabled (the default).
6892#
6893# WARNING: This may noticably slow down traffic received via external proxies
6894# or NAT devices and cause them to rebound error messages back to their clients.
6895#Default:
6896# No limit.
6897
6898# TAG: tcp_recv_bufsize (bytes)
6899# Size of receive buffer to set for TCP sockets. Probably just
6900# as easy to change your kernel's default.
6901# Omit from squid.conf to use the default buffer size.
6902#Default:
6903# Use operating system TCP defaults.
6904
6905# ICAP OPTIONS
6906# -----------------------------------------------------------------------------
6907
6908# TAG: icap_enable on|off
6909# If you want to enable the ICAP module support, set this to on.
6910#Default:
6911# icap_enable off
6912
6913# TAG: icap_connect_timeout
6914# This parameter specifies how long to wait for the TCP connect to
6915# the requested ICAP server to complete before giving up and either
6916# terminating the HTTP transaction or bypassing the failure.
6917#
6918# The default for optional services is peer_connect_timeout.
6919# The default for essential services is connect_timeout.
6920# If this option is explicitly set, its value applies to all services.
6921#Default:
6922# none
6923
6924# TAG: icap_io_timeout time-units
6925# This parameter specifies how long to wait for an I/O activity on
6926# an established, active ICAP connection before giving up and
6927# either terminating the HTTP transaction or bypassing the
6928# failure.
6929#Default:
6930# Use read_timeout.
6931
6932# TAG: icap_service_failure_limit limit [in memory-depth time-units]
6933# The limit specifies the number of failures that Squid tolerates
6934# when establishing a new TCP connection with an ICAP service. If
6935# the number of failures exceeds the limit, the ICAP service is
6936# not used for new ICAP requests until it is time to refresh its
6937# OPTIONS.
6938#
6939# A negative value disables the limit. Without the limit, an ICAP
6940# service will not be considered down due to connectivity failures
6941# between ICAP OPTIONS requests.
6942#
6943# Squid forgets ICAP service failures older than the specified
6944# value of memory-depth. The memory fading algorithm
6945# is approximate because Squid does not remember individual
6946# errors but groups them instead, splitting the option
6947# value into ten time slots of equal length.
6948#
6949# When memory-depth is 0 and by default this option has no
6950# effect on service failure expiration.
6951#
6952# Squid always forgets failures when updating service settings
6953# using an ICAP OPTIONS transaction, regardless of this option
6954# setting.
6955#
6956# For example,
6957# # suspend service usage after 10 failures in 5 seconds:
6958# icap_service_failure_limit 10 in 5 seconds
6959#Default:
6960# icap_service_failure_limit 10
6961
6962# TAG: icap_service_revival_delay
6963# The delay specifies the number of seconds to wait after an ICAP
6964# OPTIONS request failure before requesting the options again. The
6965# failed ICAP service is considered "down" until fresh OPTIONS are
6966# fetched.
6967#
6968# The actual delay cannot be smaller than the hardcoded minimum
6969# delay of 30 seconds.
6970#Default:
6971# icap_service_revival_delay 180
6972
6973# TAG: icap_preview_enable on|off
6974# The ICAP Preview feature allows the ICAP server to handle the
6975# HTTP message by looking only at the beginning of the message body
6976# or even without receiving the body at all. In some environments,
6977# previews greatly speedup ICAP processing.
6978#
6979# During an ICAP OPTIONS transaction, the server may tell Squid what
6980# HTTP messages should be previewed and how big the preview should be.
6981# Squid will not use Preview if the server did not request one.
6982#
6983# To disable ICAP Preview for all ICAP services, regardless of
6984# individual ICAP server OPTIONS responses, set this option to "off".
6985#Example:
6986#icap_preview_enable off
6987#Default:
6988# icap_preview_enable on
6989
6990# TAG: icap_preview_size
6991# The default size of preview data to be sent to the ICAP server.
6992# This value might be overwritten on a per server basis by OPTIONS requests.
6993#Default:
6994# No preview sent.
6995
6996# TAG: icap_206_enable on|off
6997# 206 (Partial Content) responses is an ICAP extension that allows the
6998# ICAP agents to optionally combine adapted and original HTTP message
6999# content. The decision to combine is postponed until the end of the
7000# ICAP response. Squid supports Partial Content extension by default.
7001#
7002# Activation of the Partial Content extension is negotiated with each
7003# ICAP service during OPTIONS exchange. Most ICAP servers should handle
7004# negotation correctly even if they do not support the extension, but
7005# some might fail. To disable Partial Content support for all ICAP
7006# services and to avoid any negotiation, set this option to "off".
7007#
7008# Example:
7009# icap_206_enable off
7010#Default:
7011# icap_206_enable on
7012
7013# TAG: icap_default_options_ttl
7014# The default TTL value for ICAP OPTIONS responses that don't have
7015# an Options-TTL header.
7016#Default:
7017# icap_default_options_ttl 60
7018
7019# TAG: icap_persistent_connections on|off
7020# Whether or not Squid should use persistent connections to
7021# an ICAP server.
7022#Default:
7023# icap_persistent_connections on
7024
7025# TAG: adaptation_send_client_ip on|off
7026# If enabled, Squid shares HTTP client IP information with adaptation
7027# services. For ICAP, Squid adds the X-Client-IP header to ICAP requests.
7028# For eCAP, Squid sets the libecap::metaClientIp transaction option.
7029#
7030# See also: adaptation_uses_indirect_client
7031#Default:
7032# adaptation_send_client_ip off
7033
7034# TAG: adaptation_send_username on|off
7035# This sends authenticated HTTP client username (if available) to
7036# the adaptation service.
7037#
7038# For ICAP, the username value is encoded based on the
7039# icap_client_username_encode option and is sent using the header
7040# specified by the icap_client_username_header option.
7041#Default:
7042# adaptation_send_username off
7043
7044# TAG: icap_client_username_header
7045# ICAP request header name to use for adaptation_send_username.
7046#Default:
7047# icap_client_username_header X-Client-Username
7048
7049# TAG: icap_client_username_encode on|off
7050# Whether to base64 encode the authenticated client username.
7051#Default:
7052# icap_client_username_encode off
7053
7054# TAG: icap_service
7055# Defines a single ICAP service using the following format:
7056#
7057# icap_service id vectoring_point uri [option ...]
7058#
7059# id: ID
7060# an opaque identifier or name which is used to direct traffic to
7061# this specific service. Must be unique among all adaptation
7062# services in squid.conf.
7063#
7064# vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
7065# This specifies at which point of transaction processing the
7066# ICAP service should be activated. *_postcache vectoring points
7067# are not yet supported.
7068#
7069# uri: icap://servername:port/servicepath
7070# ICAP server and service location.
7071#
7072# ICAP does not allow a single service to handle both REQMOD and RESPMOD
7073# transactions. Squid does not enforce that requirement. You can specify
7074# services with the same service_url and different vectoring_points. You
7075# can even specify multiple identical services as long as their
7076# service_names differ.
7077#
7078# To activate a service, use the adaptation_access directive. To group
7079# services, use adaptation_service_chain and adaptation_service_set.
7080#
7081# Service options are separated by white space. ICAP services support
7082# the following name=value options:
7083#
7084# bypass=on|off|1|0
7085# If set to 'on' or '1', the ICAP service is treated as
7086# optional. If the service cannot be reached or malfunctions,
7087# Squid will try to ignore any errors and process the message as
7088# if the service was not enabled. No all ICAP errors can be
7089# bypassed. If set to 0, the ICAP service is treated as
7090# essential and all ICAP errors will result in an error page
7091# returned to the HTTP client.
7092#
7093# Bypass is off by default: services are treated as essential.
7094#
7095# routing=on|off|1|0
7096# If set to 'on' or '1', the ICAP service is allowed to
7097# dynamically change the current message adaptation plan by
7098# returning a chain of services to be used next. The services
7099# are specified using the X-Next-Services ICAP response header
7100# value, formatted as a comma-separated list of service names.
7101# Each named service should be configured in squid.conf. Other
7102# services are ignored. An empty X-Next-Services value results
7103# in an empty plan which ends the current adaptation.
7104#
7105# Dynamic adaptation plan may cross or cover multiple supported
7106# vectoring points in their natural processing order.
7107#
7108# Routing is not allowed by default: the ICAP X-Next-Services
7109# response header is ignored.
7110#
7111# ipv6=on|off
7112# Only has effect on split-stack systems. The default on those systems
7113# is to use IPv4-only connections. When set to 'on' this option will
7114# make Squid use IPv6-only connections to contact this ICAP service.
7115#
7116# on-overload=block|bypass|wait|force
7117# If the service Max-Connections limit has been reached, do
7118# one of the following for each new ICAP transaction:
7119# * block: send an HTTP error response to the client
7120# * bypass: ignore the "over-connected" ICAP service
7121# * wait: wait (in a FIFO queue) for an ICAP connection slot
7122# * force: proceed, ignoring the Max-Connections limit
7123#
7124# In SMP mode with N workers, each worker assumes the service
7125# connection limit is Max-Connections/N, even though not all
7126# workers may use a given service.
7127#
7128# The default value is "bypass" if service is bypassable,
7129# otherwise it is set to "wait".
7130#
7131#
7132# max-conn=number
7133# Use the given number as the Max-Connections limit, regardless
7134# of the Max-Connections value given by the service, if any.
7135#
7136# Older icap_service format without optional named parameters is
7137# deprecated but supported for backward compatibility.
7138#
7139#Example:
7140#icap_service svcBlocker reqmod_precache icap://icap1.mydomain.net:1344/reqmod bypass=0
7141#icap_service svcLogger reqmod_precache icap://icap2.mydomain.net:1344/respmod routing=on
7142#Default:
7143# none
7144
7145# TAG: icap_class
7146# This deprecated option was documented to define an ICAP service
7147# chain, even though it actually defined a set of similar, redundant
7148# services, and the chains were not supported.
7149#
7150# To define a set of redundant services, please use the
7151# adaptation_service_set directive. For service chains, use
7152# adaptation_service_chain.
7153#Default:
7154# none
7155
7156# TAG: icap_access
7157# This option is deprecated. Please use adaptation_access, which
7158# has the same ICAP functionality, but comes with better
7159# documentation, and eCAP support.
7160#Default:
7161# none
7162
7163# eCAP OPTIONS
7164# -----------------------------------------------------------------------------
7165
7166# TAG: ecap_enable on|off
7167# Controls whether eCAP support is enabled.
7168#Default:
7169# ecap_enable off
7170
7171# TAG: ecap_service
7172# Defines a single eCAP service
7173#
7174# ecap_service id vectoring_point uri [option ...]
7175#
7176# id: ID
7177# an opaque identifier or name which is used to direct traffic to
7178# this specific service. Must be unique among all adaptation
7179# services in squid.conf.
7180#
7181# vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
7182# This specifies at which point of transaction processing the
7183# eCAP service should be activated. *_postcache vectoring points
7184# are not yet supported.
7185#
7186# uri: ecap://vendor/service_name?custom&cgi=style¶meters=optional
7187# Squid uses the eCAP service URI to match this configuration
7188# line with one of the dynamically loaded services. Each loaded
7189# eCAP service must have a unique URI. Obtain the right URI from
7190# the service provider.
7191#
7192# To activate a service, use the adaptation_access directive. To group
7193# services, use adaptation_service_chain and adaptation_service_set.
7194#
7195# Service options are separated by white space. eCAP services support
7196# the following name=value options:
7197#
7198# bypass=on|off|1|0
7199# If set to 'on' or '1', the eCAP service is treated as optional.
7200# If the service cannot be reached or malfunctions, Squid will try
7201# to ignore any errors and process the message as if the service
7202# was not enabled. No all eCAP errors can be bypassed.
7203# If set to 'off' or '0', the eCAP service is treated as essential
7204# and all eCAP errors will result in an error page returned to the
7205# HTTP client.
7206#
7207# Bypass is off by default: services are treated as essential.
7208#
7209# routing=on|off|1|0
7210# If set to 'on' or '1', the eCAP service is allowed to
7211# dynamically change the current message adaptation plan by
7212# returning a chain of services to be used next.
7213#
7214# Dynamic adaptation plan may cross or cover multiple supported
7215# vectoring points in their natural processing order.
7216#
7217# Routing is not allowed by default.
7218#
7219# Older ecap_service format without optional named parameters is
7220# deprecated but supported for backward compatibility.
7221#
7222#
7223#Example:
7224#ecap_service s1 reqmod_precache ecap://filters.R.us/leakDetector?on_error=block bypass=off
7225#ecap_service s2 respmod_precache ecap://filters.R.us/virusFilter config=/etc/vf.cfg bypass=on
7226#Default:
7227# none
7228
7229# TAG: loadable_modules
7230# Instructs Squid to load the specified dynamic module(s) or activate
7231# preloaded module(s).
7232#Example:
7233#loadable_modules /usr/lib/MinimalAdapter.so
7234#Default:
7235# none
7236
7237# MESSAGE ADAPTATION OPTIONS
7238# -----------------------------------------------------------------------------
7239
7240# TAG: adaptation_service_set
7241#
7242# Configures an ordered set of similar, redundant services. This is
7243# useful when hot standby or backup adaptation servers are available.
7244#
7245# adaptation_service_set set_name service_name1 service_name2 ...
7246#
7247# The named services are used in the set declaration order. The first
7248# applicable adaptation service from the set is used first. The next
7249# applicable service is tried if and only if the transaction with the
7250# previous service fails and the message waiting to be adapted is still
7251# intact.
7252#
7253# When adaptation starts, broken services are ignored as if they were
7254# not a part of the set. A broken service is a down optional service.
7255#
7256# The services in a set must be attached to the same vectoring point
7257# (e.g., pre-cache) and use the same adaptation method (e.g., REQMOD).
7258#
7259# If all services in a set are optional then adaptation failures are
7260# bypassable. If all services in the set are essential, then a
7261# transaction failure with one service may still be retried using
7262# another service from the set, but when all services fail, the master
7263# transaction fails as well.
7264#
7265# A set may contain a mix of optional and essential services, but that
7266# is likely to lead to surprising results because broken services become
7267# ignored (see above), making previously bypassable failures fatal.
7268# Technically, it is the bypassability of the last failed service that
7269# matters.
7270#
7271# See also: adaptation_access adaptation_service_chain
7272#
7273#Example:
7274#adaptation_service_set svcBlocker urlFilterPrimary urlFilterBackup
7275#adaptation service_set svcLogger loggerLocal loggerRemote
7276#Default:
7277# none
7278
7279# TAG: adaptation_service_chain
7280#
7281# Configures a list of complementary services that will be applied
7282# one-by-one, forming an adaptation chain or pipeline. This is useful
7283# when Squid must perform different adaptations on the same message.
7284#
7285# adaptation_service_chain chain_name service_name1 svc_name2 ...
7286#
7287# The named services are used in the chain declaration order. The first
7288# applicable adaptation service from the chain is used first. The next
7289# applicable service is applied to the successful adaptation results of
7290# the previous service in the chain.
7291#
7292# When adaptation starts, broken services are ignored as if they were
7293# not a part of the chain. A broken service is a down optional service.
7294#
7295# Request satisfaction terminates the adaptation chain because Squid
7296# does not currently allow declaration of RESPMOD services at the
7297# "reqmod_precache" vectoring point (see icap_service or ecap_service).
7298#
7299# The services in a chain must be attached to the same vectoring point
7300# (e.g., pre-cache) and use the same adaptation method (e.g., REQMOD).
7301#
7302# A chain may contain a mix of optional and essential services. If an
7303# essential adaptation fails (or the failure cannot be bypassed for
7304# other reasons), the master transaction fails. Otherwise, the failure
7305# is bypassed as if the failed adaptation service was not in the chain.
7306#
7307# See also: adaptation_access adaptation_service_set
7308#
7309#Example:
7310#adaptation_service_chain svcRequest requestLogger urlFilter leakDetector
7311#Default:
7312# none
7313
7314# TAG: adaptation_access
7315# Sends an HTTP transaction to an ICAP or eCAP adaptation service.
7316#
7317# adaptation_access service_name allow|deny [!]aclname...
7318# adaptation_access set_name allow|deny [!]aclname...
7319#
7320# At each supported vectoring point, the adaptation_access
7321# statements are processed in the order they appear in this
7322# configuration file. Statements pointing to the following services
7323# are ignored (i.e., skipped without checking their ACL):
7324#
7325# - services serving different vectoring points
7326# - "broken-but-bypassable" services
7327# - "up" services configured to ignore such transactions
7328# (e.g., based on the ICAP Transfer-Ignore header).
7329#
7330# When a set_name is used, all services in the set are checked
7331# using the same rules, to find the first applicable one. See
7332# adaptation_service_set for details.
7333#
7334# If an access list is checked and there is a match, the
7335# processing stops: For an "allow" rule, the corresponding
7336# adaptation service is used for the transaction. For a "deny"
7337# rule, no adaptation service is activated.
7338#
7339# It is currently not possible to apply more than one adaptation
7340# service at the same vectoring point to the same HTTP transaction.
7341#
7342# See also: icap_service and ecap_service
7343#
7344#Example:
7345#adaptation_access service_1 allow all
7346#Default:
7347# Allow, unless rules exist in squid.conf.
7348
7349# TAG: adaptation_service_iteration_limit
7350# Limits the number of iterations allowed when applying adaptation
7351# services to a message. If your longest adaptation set or chain
7352# may have more than 16 services, increase the limit beyond its
7353# default value of 16. If detecting infinite iteration loops sooner
7354# is critical, make the iteration limit match the actual number
7355# of services in your longest adaptation set or chain.
7356#
7357# Infinite adaptation loops are most likely with routing services.
7358#
7359# See also: icap_service routing=1
7360#Default:
7361# adaptation_service_iteration_limit 16
7362
7363# TAG: adaptation_masterx_shared_names
7364# For each master transaction (i.e., the HTTP request and response
7365# sequence, including all related ICAP and eCAP exchanges), Squid
7366# maintains a table of metadata. The table entries are (name, value)
7367# pairs shared among eCAP and ICAP exchanges. The table is destroyed
7368# with the master transaction.
7369#
7370# This option specifies the table entry names that Squid must accept
7371# from and forward to the adaptation transactions.
7372#
7373# An ICAP REQMOD or RESPMOD transaction may set an entry in the
7374# shared table by returning an ICAP header field with a name
7375# specified in adaptation_masterx_shared_names.
7376#
7377# An eCAP REQMOD or RESPMOD transaction may set an entry in the
7378# shared table by implementing the libecap::visitEachOption() API
7379# to provide an option with a name specified in
7380# adaptation_masterx_shared_names.
7381#
7382# Squid will store and forward the set entry to subsequent adaptation
7383# transactions within the same master transaction scope.
7384#
7385# Only one shared entry name is supported at this time.
7386#
7387#Example:
7388## share authentication information among ICAP services
7389#adaptation_masterx_shared_names X-Subscriber-ID
7390#Default:
7391# none
7392
7393# TAG: adaptation_meta
7394# This option allows Squid administrator to add custom ICAP request
7395# headers or eCAP options to Squid ICAP requests or eCAP transactions.
7396# Use it to pass custom authentication tokens and other
7397# transaction-state related meta information to an ICAP/eCAP service.
7398#
7399# The addition of a meta header is ACL-driven:
7400# adaptation_meta name value [!]aclname ...
7401#
7402# Processing for a given header name stops after the first ACL list match.
7403# Thus, it is impossible to add two headers with the same name. If no ACL
7404# lists match for a given header name, no such header is added. For
7405# example:
7406#
7407# # do not debug transactions except for those that need debugging
7408# adaptation_meta X-Debug 1 needs_debugging
7409#
7410# # log all transactions except for those that must remain secret
7411# adaptation_meta X-Log 1 !keep_secret
7412#
7413# # mark transactions from users in the "G 1" group
7414# adaptation_meta X-Authenticated-Groups "G 1" authed_as_G1
7415#
7416# The "value" parameter may be a regular squid.conf token or a "double
7417# quoted string". Within the quoted string, use backslash (\) to escape
7418# any character, which is currently only useful for escaping backslashes
7419# and double quotes. For example,
7420# "this string has one backslash (\\) and two \"quotes\""
7421#
7422# Used adaptation_meta header values may be logged via %note
7423# logformat code. If multiple adaptation_meta headers with the same name
7424# are used during master transaction lifetime, the header values are
7425# logged in the order they were used and duplicate values are ignored
7426# (only the first repeated value will be logged).
7427#Default:
7428# none
7429
7430# TAG: icap_retry
7431# This ACL determines which retriable ICAP transactions are
7432# retried. Transactions that received a complete ICAP response
7433# and did not have to consume or produce HTTP bodies to receive
7434# that response are usually retriable.
7435#
7436# icap_retry allow|deny [!]aclname ...
7437#
7438# Squid automatically retries some ICAP I/O timeouts and errors
7439# due to persistent connection race conditions.
7440#
7441# See also: icap_retry_limit
7442#Default:
7443# icap_retry deny all
7444
7445# TAG: icap_retry_limit
7446# Limits the number of retries allowed.
7447#
7448# Communication errors due to persistent connection race
7449# conditions are unavoidable, automatically retried, and do not
7450# count against this limit.
7451#
7452# See also: icap_retry
7453#Default:
7454# No retries are allowed.
7455
7456# DNS OPTIONS
7457# -----------------------------------------------------------------------------
7458
7459# TAG: check_hostnames
7460# For security and stability reasons Squid can check
7461# hostnames for Internet standard RFC compliance. If you want
7462# Squid to perform these checks turn this directive on.
7463#Default:
7464# check_hostnames off
7465
7466# TAG: allow_underscore
7467# Underscore characters is not strictly allowed in Internet hostnames
7468# but nevertheless used by many sites. Set this to off if you want
7469# Squid to be strict about the standard.
7470# This check is performed only when check_hostnames is set to on.
7471#Default:
7472# allow_underscore on
7473
7474# TAG: dns_retransmit_interval
7475# Initial retransmit interval for DNS queries. The interval is
7476# doubled each time all configured DNS servers have been tried.
7477#Default:
7478# dns_retransmit_interval 5 seconds
7479
7480# TAG: dns_timeout
7481# DNS Query timeout. If no response is received to a DNS query
7482# within this time all DNS servers for the queried domain
7483# are assumed to be unavailable.
7484#Default:
7485# dns_timeout 30 seconds
7486
7487# TAG: dns_packet_max
7488# Maximum number of bytes packet size to advertise via EDNS.
7489# Set to "none" to disable EDNS large packet support.
7490#
7491# For legacy reasons DNS UDP replies will default to 512 bytes which
7492# is too small for many responses. EDNS provides a means for Squid to
7493# negotiate receiving larger responses back immediately without having
7494# to failover with repeat requests. Responses larger than this limit
7495# will retain the old behaviour of failover to TCP DNS.
7496#
7497# Squid has no real fixed limit internally, but allowing packet sizes
7498# over 1500 bytes requires network jumbogram support and is usually not
7499# necessary.
7500#
7501# WARNING: The RFC also indicates that some older resolvers will reply
7502# with failure of the whole request if the extension is added. Some
7503# resolvers have already been identified which will reply with mangled
7504# EDNS response on occasion. Usually in response to many-KB jumbogram
7505# sizes being advertised by Squid.
7506# Squid will currently treat these both as an unable-to-resolve domain
7507# even if it would be resolvable without EDNS.
7508#Default:
7509# EDNS disabled
7510
7511# TAG: dns_defnames on|off
7512# Normally the RES_DEFNAMES resolver option is disabled
7513# (see res_init(3)). This prevents caches in a hierarchy
7514# from interpreting single-component hostnames locally. To allow
7515# Squid to handle single-component names, enable this option.
7516#Default:
7517# Search for single-label domain names is disabled.
7518
7519# TAG: dns_multicast_local on|off
7520# When set to on, Squid sends multicast DNS lookups on the local
7521# network for domains ending in .local and .arpa.
7522# This enables local servers and devices to be contacted in an
7523# ad-hoc or zero-configuration network environment.
7524#Default:
7525# Search for .local and .arpa names is disabled.
7526
7527# TAG: dns_nameservers
7528# Use this if you want to specify a list of DNS name servers
7529# (IP addresses) to use instead of those given in your
7530# /etc/resolv.conf file.
7531#
7532# On Windows platforms, if no value is specified here or in
7533# the /etc/resolv.conf file, the list of DNS name servers are
7534# taken from the Windows registry, both static and dynamic DHCP
7535# configurations are supported.
7536#
7537# Example: dns_nameservers 10.0.0.1 192.172.0.4
7538#Default:
7539# Use operating system definitions
7540
7541# TAG: hosts_file
7542# Location of the host-local IP name-address associations
7543# database. Most Operating Systems have such a file on different
7544# default locations:
7545# - Un*X & Linux: /etc/hosts
7546# - Windows NT/2000: %SystemRoot%\system32\drivers\etc\hosts
7547# (%SystemRoot% value install default is c:\winnt)
7548# - Windows XP/2003: %SystemRoot%\system32\drivers\etc\hosts
7549# (%SystemRoot% value install default is c:\windows)
7550# - Windows 9x/Me: %windir%\hosts
7551# (%windir% value is usually c:\windows)
7552# - Cygwin: /etc/hosts
7553#
7554# The file contains newline-separated definitions, in the
7555# form ip_address_in_dotted_form name [name ...] names are
7556# whitespace-separated. Lines beginning with an hash (#)
7557# character are comments.
7558#
7559# The file is checked at startup and upon configuration.
7560# If set to 'none', it won't be checked.
7561# If append_domain is used, that domain will be added to
7562# domain-local (i.e. not containing any dot character) host
7563# definitions.
7564#Default:
7565# hosts_file /etc/hosts
7566
7567# TAG: append_domain
7568# Appends local domain name to hostnames without any dots in
7569# them. append_domain must begin with a period.
7570#
7571# Be warned there are now Internet names with no dots in
7572# them using only top-domain names, so setting this may
7573# cause some Internet sites to become unavailable.
7574#
7575#Example:
7576# append_domain .yourdomain.com
7577#Default:
7578# Use operating system definitions
7579
7580# TAG: ignore_unknown_nameservers
7581# By default Squid checks that DNS responses are received
7582# from the same IP addresses they are sent to. If they
7583# don't match, Squid ignores the response and writes a warning
7584# message to cache.log. You can allow responses from unknown
7585# nameservers by setting this option to 'off'.
7586#Default:
7587# ignore_unknown_nameservers on
7588
7589# TAG: dns_v4_first
7590# With the IPv6 Internet being as fast or faster than IPv4 Internet
7591# for most networks Squid prefers to contact websites over IPv6.
7592#
7593# This option reverses the order of preference to make Squid contact
7594# dual-stack websites over IPv4 first. Squid will still perform both
7595# IPv6 and IPv4 DNS lookups before connecting.
7596#
7597# WARNING:
7598# This option will restrict the situations under which IPv6
7599# connectivity is used (and tested). Hiding network problems
7600# which would otherwise be detected and warned about.
7601#Default:
7602# dns_v4_first off
7603
7604# TAG: ipcache_size (number of entries)
7605# Maximum number of DNS IP cache entries.
7606#Default:
7607# ipcache_size 1024
7608
7609# TAG: ipcache_low (percent)
7610#Default:
7611# ipcache_low 90
7612
7613# TAG: ipcache_high (percent)
7614# The size, low-, and high-water marks for the IP cache.
7615#Default:
7616# ipcache_high 95
7617
7618# TAG: fqdncache_size (number of entries)
7619# Maximum number of FQDN cache entries.
7620#Default:
7621# fqdncache_size 1024
7622
7623# MISCELLANEOUS
7624# -----------------------------------------------------------------------------
7625
7626# TAG: configuration_includes_quoted_values on|off
7627# If set, Squid will recognize each "quoted string" after a configuration
7628# directive as a single parameter. The quotes are stripped before the
7629# parameter value is interpreted or used.
7630# See "Values with spaces, quotes, and other special characters"
7631# section for more details.
7632#Default:
7633# configuration_includes_quoted_values off
7634
7635# TAG: memory_pools on|off
7636# If set, Squid will keep pools of allocated (but unused) memory
7637# available for future use. If memory is a premium on your
7638# system and you believe your malloc library outperforms Squid
7639# routines, disable this.
7640#Default:
7641# memory_pools on
7642
7643# TAG: memory_pools_limit (bytes)
7644# Used only with memory_pools on:
7645# memory_pools_limit 50 MB
7646#
7647# If set to a non-zero value, Squid will keep at most the specified
7648# limit of allocated (but unused) memory in memory pools. All free()
7649# requests that exceed this limit will be handled by your malloc
7650# library. Squid does not pre-allocate any memory, just safe-keeps
7651# objects that otherwise would be free()d. Thus, it is safe to set
7652# memory_pools_limit to a reasonably high value even if your
7653# configuration will use less memory.
7654#
7655# If set to none, Squid will keep all memory it can. That is, there
7656# will be no limit on the total amount of memory used for safe-keeping.
7657#
7658# To disable memory allocation optimization, do not set
7659# memory_pools_limit to 0 or none. Set memory_pools to "off" instead.
7660#
7661# An overhead for maintaining memory pools is not taken into account
7662# when the limit is checked. This overhead is close to four bytes per
7663# object kept. However, pools may actually _save_ memory because of
7664# reduced memory thrashing in your malloc library.
7665#Default:
7666# memory_pools_limit 5 MB
7667
7668# TAG: forwarded_for on|off|transparent|truncate|delete
7669# If set to "on", Squid will append your client's IP address
7670# in the HTTP requests it forwards. By default it looks like:
7671#
7672# X-Forwarded-For: 192.1.2.3
7673#
7674# If set to "off", it will appear as
7675#
7676# X-Forwarded-For: unknown
7677#
7678# If set to "transparent", Squid will not alter the
7679# X-Forwarded-For header in any way.
7680#
7681# If set to "delete", Squid will delete the entire
7682# X-Forwarded-For header.
7683#
7684# If set to "truncate", Squid will remove all existing
7685# X-Forwarded-For entries, and place the client IP as the sole entry.
7686#Default:
7687# forwarded_for on
7688
7689# TAG: cachemgr_passwd
7690# Specify passwords for cachemgr operations.
7691#
7692# Usage: cachemgr_passwd password action action ...
7693#
7694# Some valid actions are (see cache manager menu for a full list):
7695# 5min
7696# 60min
7697# asndb
7698# authenticator
7699# cbdata
7700# client_list
7701# comm_incoming
7702# config *
7703# counters
7704# delay
7705# digest_stats
7706# dns
7707# events
7708# filedescriptors
7709# fqdncache
7710# histograms
7711# http_headers
7712# info
7713# io
7714# ipcache
7715# mem
7716# menu
7717# netdb
7718# non_peers
7719# objects
7720# offline_toggle *
7721# pconn
7722# peer_select
7723# reconfigure *
7724# redirector
7725# refresh
7726# server_list
7727# shutdown *
7728# store_digest
7729# storedir
7730# utilization
7731# via_headers
7732# vm_objects
7733#
7734# * Indicates actions which will not be performed without a
7735# valid password, others can be performed if not listed here.
7736#
7737# To disable an action, set the password to "disable".
7738# To allow performing an action without a password, set the
7739# password to "none".
7740#
7741# Use the keyword "all" to set the same password for all actions.
7742#
7743#Example:
7744# cachemgr_passwd secret shutdown
7745# cachemgr_passwd lesssssssecret info stats/objects
7746# cachemgr_passwd disable all
7747#Default:
7748# No password. Actions which require password are denied.
7749
7750# TAG: client_db on|off
7751# If you want to disable collecting per-client statistics,
7752# turn off client_db here.
7753#Default:
7754# client_db on
7755
7756# TAG: refresh_all_ims on|off
7757# When you enable this option, squid will always check
7758# the origin server for an update when a client sends an
7759# If-Modified-Since request. Many browsers use IMS
7760# requests when the user requests a reload, and this
7761# ensures those clients receive the latest version.
7762#
7763# By default (off), squid may return a Not Modified response
7764# based on the age of the cached version.
7765#Default:
7766# refresh_all_ims off
7767
7768# TAG: reload_into_ims on|off
7769# When you enable this option, client no-cache or ``reload''
7770# requests will be changed to If-Modified-Since requests.
7771# Doing this VIOLATES the HTTP standard. Enabling this
7772# feature could make you liable for problems which it
7773# causes.
7774#
7775# see also refresh_pattern for a more selective approach.
7776#Default:
7777# reload_into_ims off
7778
7779# TAG: connect_retries
7780# This sets the maximum number of connection attempts made for each
7781# TCP connection. The connect_retries attempts must all still
7782# complete within the connection timeout period.
7783#
7784# The default is not to re-try if the first connection attempt fails.
7785# The (not recommended) maximum is 10 tries.
7786#
7787# A warning message will be generated if it is set to a too-high
7788# value and the configured value will be over-ridden.
7789#
7790# Note: These re-tries are in addition to forward_max_tries
7791# which limit how many different addresses may be tried to find
7792# a useful server.
7793#Default:
7794# Do not retry failed connections.
7795
7796# TAG: retry_on_error
7797# If set to ON Squid will automatically retry requests when
7798# receiving an error response with status 403 (Forbidden),
7799# 500 (Internal Error), 501 or 503 (Service not available).
7800# Status 502 and 504 (Gateway errors) are always retried.
7801#
7802# This is mainly useful if you are in a complex cache hierarchy to
7803# work around access control errors.
7804#
7805# NOTE: This retry will attempt to find another working destination.
7806# Which is different from the server which just failed.
7807#Default:
7808# retry_on_error off
7809
7810# TAG: as_whois_server
7811# WHOIS server to query for AS numbers. NOTE: AS numbers are
7812# queried only when Squid starts up, not for every request.
7813#Default:
7814# as_whois_server whois.ra.net
7815
7816# TAG: offline_mode
7817# Enable this option and Squid will never try to validate cached
7818# objects.
7819#Default:
7820# offline_mode off
7821
7822# TAG: uri_whitespace
7823# What to do with requests that have whitespace characters in the
7824# URI. Options:
7825#
7826# strip: The whitespace characters are stripped out of the URL.
7827# This is the behavior recommended by RFC2396 and RFC3986
7828# for tolerant handling of generic URI.
7829# NOTE: This is one difference between generic URI and HTTP URLs.
7830#
7831# deny: The request is denied. The user receives an "Invalid
7832# Request" message.
7833# This is the behaviour recommended by RFC2616 for safe
7834# handling of HTTP request URL.
7835#
7836# allow: The request is allowed and the URI is not changed. The
7837# whitespace characters remain in the URI. Note the
7838# whitespace is passed to redirector processes if they
7839# are in use.
7840# Note this may be considered a violation of RFC2616
7841# request parsing where whitespace is prohibited in the
7842# URL field.
7843#
7844# encode: The request is allowed and the whitespace characters are
7845# encoded according to RFC1738.
7846#
7847# chop: The request is allowed and the URI is chopped at the
7848# first whitespace.
7849#
7850#
7851# NOTE the current Squid implementation of encode and chop violates
7852# RFC2616 by not using a 301 redirect after altering the URL.
7853#Default:
7854# uri_whitespace strip
7855
7856# TAG: chroot
7857# Specifies a directory where Squid should do a chroot() while
7858# initializing. This also causes Squid to fully drop root
7859# privileges after initializing. This means, for example, if you
7860# use a HTTP port less than 1024 and try to reconfigure, you may
7861# get an error saying that Squid can not open the port.
7862#Default:
7863# none
7864
7865# TAG: balance_on_multiple_ip
7866# Modern IP resolvers in squid sort lookup results by preferred access.
7867# By default squid will use these IP in order and only rotates to
7868# the next listed when the most preffered fails.
7869#
7870# Some load balancing servers based on round robin DNS have been
7871# found not to preserve user session state across requests
7872# to different IP addresses.
7873#
7874# Enabling this directive Squid rotates IP's per request.
7875#Default:
7876# balance_on_multiple_ip off
7877
7878# TAG: pipeline_prefetch
7879# HTTP clients may send a pipeline of 1+N requests to Squid using a
7880# single connection, without waiting for Squid to respond to the first
7881# of those requests. This option limits the number of concurrent
7882# requests Squid will try to handle in parallel. If set to N, Squid
7883# will try to receive and process up to 1+N requests on the same
7884# connection concurrently.
7885#
7886# Defaults to 0 (off) for bandwidth management and access logging
7887# reasons.
7888#
7889# NOTE: pipelining requires persistent connections to clients.
7890#
7891# WARNING: pipelining breaks NTLM and Negotiate/Kerberos authentication.
7892#Default:
7893# Do not pre-parse pipelined requests.
7894
7895# TAG: high_response_time_warning (msec)
7896# If the one-minute median response time exceeds this value,
7897# Squid prints a WARNING with debug level 0 to get the
7898# administrators attention. The value is in milliseconds.
7899#Default:
7900# disabled.
7901
7902# TAG: high_page_fault_warning
7903# If the one-minute average page fault rate exceeds this
7904# value, Squid prints a WARNING with debug level 0 to get
7905# the administrators attention. The value is in page faults
7906# per second.
7907#Default:
7908# disabled.
7909
7910# TAG: high_memory_warning
7911# Note: This option is only available if Squid is rebuilt with the
7912# GNU Malloc with mstats()
7913#
7914# If the memory usage (as determined by gnumalloc, if available and used)
7915# exceeds this amount, Squid prints a WARNING with debug level 0 to get
7916# the administrators attention.
7917#Default:
7918# disabled.
7919
7920# TAG: sleep_after_fork (microseconds)
7921# When this is set to a non-zero value, the main Squid process
7922# sleeps the specified number of microseconds after a fork()
7923# system call. This sleep may help the situation where your
7924# system reports fork() failures due to lack of (virtual)
7925# memory. Note, however, if you have a lot of child
7926# processes, these sleep delays will add up and your
7927# Squid will not service requests for some amount of time
7928# until all the child processes have been started.
7929# On Windows value less then 1000 (1 milliseconds) are
7930# rounded to 1000.
7931#Default:
7932# sleep_after_fork 0
7933
7934# TAG: windows_ipaddrchangemonitor on|off
7935# Note: This option is only available if Squid is rebuilt with the
7936# MS Windows
7937#
7938# On Windows Squid by default will monitor IP address changes and will
7939# reconfigure itself after any detected event. This is very useful for
7940# proxies connected to internet with dial-up interfaces.
7941# In some cases (a Proxy server acting as VPN gateway is one) it could be
7942# desiderable to disable this behaviour setting this to 'off'.
7943# Note: after changing this, Squid service must be restarted.
7944#Default:
7945# windows_ipaddrchangemonitor on
7946
7947# TAG: eui_lookup
7948# Whether to lookup the EUI or MAC address of a connected client.
7949#Default:
7950# eui_lookup on
7951
7952# TAG: max_filedescriptors
7953# Reduce the maximum number of filedescriptors supported below
7954# the usual operating system defaults.
7955#
7956# Remove from squid.conf to inherit the current ulimit setting.
7957#
7958# Note: Changing this requires a restart of Squid. Also
7959# not all I/O types supports large values (eg on Windows).
7960#Default:
7961# Use operating system limits set by ulimit.