· 10 years ago · Aug 17, 2016, 09:46 PM
1# WELCOME TO SQUID 3.3.8
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#
37# Conditional configuration
38#
39# If-statements can be used to make configuration directives
40# depend on conditions:
41#
42# if <CONDITION>
43# ... regular configuration directives ...
44# [else
45# ... regular configuration directives ...]
46# endif
47#
48# The else part is optional. The keywords "if", "else", and "endif"
49# must be typed on their own lines, as if they were regular
50# configuration directives.
51#
52# NOTE: An else-if condition is not supported.
53#
54# These individual conditions types are supported:
55#
56# true
57# Always evaluates to true.
58# false
59# Always evaluates to false.
60# <integer> = <integer>
61# Equality comparison of two integer numbers.
62#
63#
64# SMP-Related Macros
65#
66# The following SMP-related preprocessor macros can be used.
67#
68# ${process_name} expands to the current Squid process "name"
69# (e.g., squid1, squid2, or cache1).
70#
71# ${process_number} expands to the current Squid process
72# identifier, which is an integer number (e.g., 1, 2, 3) unique
73# across all Squid processes.
74
75# TAG: broken_vary_encoding
76# This option is not yet supported by Squid-3.
77#Default:
78# none
79
80# TAG: cache_vary
81# This option is not yet supported by Squid-3.
82#Default:
83# none
84
85# TAG: collapsed_forwarding
86# This option is not yet supported by Squid-3. see http://bugs.squid-cache.org/show_bug.cgi?id=3495
87#Default:
88# none
89
90# TAG: error_map
91# This option is not yet supported by Squid-3.
92#Default:
93# none
94
95# TAG: external_refresh_check
96# This option is not yet supported by Squid-3.
97#Default:
98# none
99
100# TAG: ignore_ims_on_miss
101# This option is not yet supported by Squid-3.
102#Default:
103# none
104
105# TAG: location_rewrite_program
106# This option is not yet supported by Squid-3.
107#Default:
108# none
109
110# TAG: refresh_stale_hit
111# This option is not yet supported by Squid-3.
112#Default:
113# none
114
115# TAG: storeurl_access
116# This option is not yet supported by this version of Squid-3. Please try a later release.
117#Default:
118# none
119
120# TAG: ignore_expect_100
121# Remove this line. The HTTP/1.1 feature is now fully supported by default.
122#Default:
123# none
124
125# TAG: dns_v4_fallback
126# Remove this line. Squid performs a 'Happy Eyeballs' algorithm, the 'fallback' algorithm is no longer relevant.
127#Default:
128# none
129
130# TAG: ftp_list_width
131# Remove this line. Configure FTP page display using the CSS controls in errorpages.css instead.
132#Default:
133# none
134
135# TAG: maximum_single_addr_tries
136# Replaced by connect_retries. The behaviour has changed, please read the documentation before altering.
137#Default:
138# none
139
140# TAG: update_headers
141# Remove this line. The feature is supported by default in storage types where update is implemented.
142#Default:
143# none
144
145# TAG: url_rewrite_concurrency
146# Remove this line. Set the 'concurrency=' option of url_rewrite_children instead.
147#Default:
148# none
149
150# TAG: dns_testnames
151# Remove this line. DNS is no longer tested on startup.
152#Default:
153# none
154
155# TAG: extension_methods
156# Remove this line. All valid methods for HTTP are accepted by default.
157#Default:
158# none
159
160# TAG: zero_buffers
161#Default:
162# none
163
164# TAG: incoming_rate
165#Default:
166# none
167
168# TAG: server_http11
169# Remove this line. HTTP/1.1 is supported by default.
170#Default:
171# none
172
173# TAG: upgrade_http0.9
174# Remove this line. ICY/1.0 streaming protocol is supported by default.
175#Default:
176# none
177
178# TAG: zph_local
179# Alter these entries. Use the qos_flows directive instead.
180#Default:
181# none
182
183# TAG: header_access
184# Since squid-3.0 replace with request_header_access or reply_header_access
185# depending on whether you wish to match client requests or server replies.
186#Default:
187# none
188
189# TAG: httpd_accel_no_pmtu_disc
190# Since squid-3.0 use the 'disable-pmtu-discovery' flag on http_port instead.
191#Default:
192# none
193
194# TAG: wais_relay_host
195# Replace this line with 'cache_peer' configuration.
196#Default:
197# none
198
199# TAG: wais_relay_port
200# Replace this line with 'cache_peer' configuration.
201#Default:
202# none
203
204# OPTIONS FOR AUTHENTICATION
205# -----------------------------------------------------------------------------
206
207# TAG: auth_param
208# This is used to define parameters for the various authentication
209# schemes supported by Squid.
210#
211# format: auth_param scheme parameter [setting]
212#
213# The order in which authentication schemes are presented to the client is
214# dependent on the order the scheme first appears in config file. IE
215# has a bug (it's not RFC 2617 compliant) in that it will use the basic
216# scheme if basic is the first entry presented, even if more secure
217# schemes are presented. For now use the order in the recommended
218# settings section below. If other browsers have difficulties (don't
219# recognize the schemes offered even if you are using basic) either
220# put basic first, or disable the other schemes (by commenting out their
221# program entry).
222#
223# Once an authentication scheme is fully configured, it can only be
224# shutdown by shutting squid down and restarting. Changes can be made on
225# the fly and activated with a reconfigure. I.E. You can change to a
226# different helper, but not unconfigure the helper completely.
227#
228# Please note that while this directive defines how Squid processes
229# authentication it does not automatically activate authentication.
230# To use authentication you must in addition make use of ACLs based
231# on login name in http_access (proxy_auth, proxy_auth_regex or
232# external with %LOGIN used in the format tag). The browser will be
233# challenged for authentication on the first such acl encountered
234# in http_access processing and will also be re-challenged for new
235# login credentials if the request is being denied by a proxy_auth
236# type acl.
237#
238# WARNING: authentication can't be used in a transparently intercepting
239# proxy as the client then thinks it is talking to an origin server and
240# not the proxy. This is a limitation of bending the TCP/IP protocol to
241# transparently intercepting port 80, not a limitation in Squid.
242# Ports flagged 'transparent', 'intercept', or 'tproxy' have
243# authentication disabled.
244#
245# === Parameters for the basic scheme follow. ===
246#
247# "program" cmdline
248# Specify the command for the external authenticator. Such a program
249# reads a line containing "username password" and replies "OK" or
250# "ERR" in an endless loop. "ERR" responses may optionally be followed
251# by a error description available as %m in the returned error page.
252# If you use an authenticator, make sure you have 1 acl of type
253# proxy_auth.
254#
255# By default, the basic authentication scheme is not used unless a
256# program is specified.
257#
258# If you want to use the traditional NCSA proxy authentication, set
259# this line to something like
260#
261# auth_param basic program /usr/lib/squid3/basic_ncsa_auth /usr/etc/passwd
262#
263# "utf8" on|off
264# HTTP uses iso-latin-1 as character set, while some authentication
265# backends such as LDAP expects UTF-8. If this is set to on Squid will
266# translate the HTTP iso-latin-1 charset to UTF-8 before sending the
267# username & password to the helper.
268#
269# "children" numberofchildren [startup=N] [idle=N] [concurrency=N]
270# The maximum number of authenticator processes to spawn. If you start too few
271# Squid will have to wait for them to process a backlog of credential
272# verifications, slowing it down. When password verifications are
273# done via a (slow) network you are likely to need lots of
274# authenticator processes.
275#
276# The startup= and idle= options permit some skew in the exact amount
277# run. A minimum of startup=N will begin during startup and reconfigure.
278# Squid will start more in groups of up to idle=N in an attempt to meet
279# traffic needs and to keep idle=N free above those traffic needs up to
280# the maximum.
281#
282# The concurrency= option sets the number of concurrent requests the
283# helper can process. The default of 0 is used for helpers who only
284# supports one request at a time. Setting this to a number greater than
285# 0 changes the protocol used to include a channel number first on the
286# request/response line, allowing multiple requests to be sent to the
287# same helper in parallel without waiting for the response.
288# Must not be set unless it's known the helper supports this.
289#
290# auth_param basic children 20 startup=0 idle=1
291#
292# "realm" realmstring
293# Specifies the realm name which is to be reported to the
294# client for the basic proxy authentication scheme (part of
295# the text the user will see when prompted their username and
296# password). There is no default.
297# auth_param basic realm Squid proxy-caching web server
298#
299# "credentialsttl" timetolive
300# Specifies how long squid assumes an externally validated
301# username:password pair is valid for - in other words how
302# often the helper program is called for that user. Set this
303# low to force revalidation with short lived passwords. Note
304# setting this high does not impact your susceptibility
305# to replay attacks unless you are using an one-time password
306# system (such as SecureID). If you are using such a system,
307# you will be vulnerable to replay attacks unless you also
308# use the max_user_ip ACL in an http_access rule.
309#
310# "casesensitive" on|off
311# Specifies if usernames are case sensitive. Most user databases are
312# case insensitive allowing the same username to be spelled using both
313# lower and upper case letters, but some are case sensitive. This
314# makes a big difference for user_max_ip ACL processing and similar.
315# auth_param basic casesensitive off
316#
317# === Parameters for the digest scheme follow ===
318#
319# "program" cmdline
320# Specify the command for the external authenticator. Such
321# a program reads a line containing "username":"realm" and
322# replies with the appropriate H(A1) value hex encoded or
323# ERR if the user (or his H(A1) hash) does not exists.
324# See rfc 2616 for the definition of H(A1).
325# "ERR" responses may optionally be followed by a error description
326# available as %m in the returned error page.
327#
328# By default, the digest authentication scheme is not used unless a
329# program is specified.
330#
331# If you want to use a digest authenticator, set this line to
332# something like
333#
334# auth_param digest program /usr/lib/squid3/digest_pw_auth /usr/etc/digpass
335#
336# "utf8" on|off
337# HTTP uses iso-latin-1 as character set, while some authentication
338# backends such as LDAP expects UTF-8. If this is set to on Squid will
339# translate the HTTP iso-latin-1 charset to UTF-8 before sending the
340# username & password to the helper.
341#
342# "children" numberofchildren [startup=N] [idle=N] [concurrency=N]
343# The maximum number of authenticator processes to spawn (default 5).
344# If you start too few Squid will have to wait for them to
345# process a backlog of H(A1) calculations, slowing it down.
346# When the H(A1) calculations are done via a (slow) network
347# you are likely to need lots of authenticator processes.
348#
349# The startup= and idle= options permit some skew in the exact amount
350# run. A minimum of startup=N will begin during startup and reconfigure.
351# Squid will start more in groups of up to idle=N in an attempt to meet
352# traffic needs and to keep idle=N free above those traffic needs up to
353# the maximum.
354#
355# The concurrency= option sets the number of concurrent requests the
356# helper can process. The default of 0 is used for helpers who only
357# supports one request at a time. Setting this to a number greater than
358# 0 changes the protocol used to include a channel number first on the
359# request/response line, allowing multiple requests to be sent to the
360# same helper in parallel without waiting for the response.
361# Must not be set unless it's known the helper supports this.
362#
363# auth_param digest children 20 startup=0 idle=1
364#
365# "realm" realmstring
366# Specifies the realm name which is to be reported to the
367# client for the digest proxy authentication scheme (part of
368# the text the user will see when prompted their username and
369# password). There is no default.
370# auth_param digest realm Squid proxy-caching web server
371#
372# "nonce_garbage_interval" timeinterval
373# Specifies the interval that nonces that have been issued
374# to client_agent's are checked for validity.
375#
376# "nonce_max_duration" timeinterval
377# Specifies the maximum length of time a given nonce will be
378# valid for.
379#
380# "nonce_max_count" number
381# Specifies the maximum number of times a given nonce can be
382# used.
383#
384# "nonce_strictness" on|off
385# Determines if squid requires strict increment-by-1 behavior
386# for nonce counts, or just incrementing (off - for use when
387# user agents generate nonce counts that occasionally miss 1
388# (ie, 1,2,4,6)). Default off.
389#
390# "check_nonce_count" on|off
391# This directive if set to off can disable the nonce count check
392# completely to work around buggy digest qop implementations in
393# certain mainstream browser versions. Default on to check the
394# nonce count to protect from authentication replay attacks.
395#
396# "post_workaround" on|off
397# This is a workaround to certain buggy browsers who sends
398# an incorrect request digest in POST requests when reusing
399# the same nonce as acquired earlier on a GET request.
400#
401# === NTLM scheme options follow ===
402#
403# "program" cmdline
404# Specify the command for the external NTLM authenticator.
405# Such a program reads exchanged NTLMSSP packets with
406# the browser via Squid until authentication is completed.
407# If you use an NTLM authenticator, make sure you have 1 acl
408# of type proxy_auth. By default, the NTLM authenticator_program
409# is not used.
410#
411# NOTE: In Debian the ntlm_auth program is distributed in the winbindd package
412# which is required for this auth scheme to work
413#
414# auth_param ntlm program /usr/bin/ntlm_auth
415#
416# "children" numberofchildren [startup=N] [idle=N]
417# The maximum number of authenticator processes to spawn (default 5).
418# If you start too few Squid will have to wait for them to
419# process a backlog of credential verifications, slowing it
420# down. When credential verifications are done via a (slow)
421# network you are likely to need lots of authenticator
422# processes.
423#
424# The startup= and idle= options permit some skew in the exact amount
425# run. A minimum of startup=N will begin during startup and reconfigure.
426# Squid will start more in groups of up to idle=N in an attempt to meet
427# traffic needs and to keep idle=N free above those traffic needs up to
428# the maximum.
429#
430# auth_param ntlm children 20 startup=0 idle=1
431#
432# "keep_alive" on|off
433# If you experience problems with PUT/POST requests when using the
434# Negotiate authentication scheme then you can try setting this to
435# off. This will cause Squid to forcibly close the connection on
436# the initial requests where the browser asks which schemes are
437# supported by the proxy.
438#
439# auth_param ntlm keep_alive on
440#
441# === Options for configuring the NEGOTIATE auth-scheme follow ===
442#
443# "program" cmdline
444# Specify the command for the external Negotiate authenticator.
445# This protocol is used in Microsoft Active-Directory enabled setups with
446# the Microsoft Internet Explorer or Mozilla Firefox browsers.
447# Its main purpose is to exchange credentials with the Squid proxy
448# using the Kerberos mechanisms.
449# If you use a Negotiate authenticator, make sure you have at least
450# one acl of type proxy_auth active. By default, the negotiate
451# authenticator_program is not used.
452# The only supported program for this role is the ntlm_auth
453# program distributed as part of Samba, version 4 or later.
454#
455# NOTE: In Debian the ntlm_auth program is distributed in the winbindd package
456# which is required for this auth scheme to work
457#
458# auth_param negotiate program /usr/bin/ntlm_auth --helper-protocol=gss-spnego
459#
460# "children" numberofchildren [startup=N] [idle=N]
461# The maximum number of authenticator processes to spawn (default 5).
462# If you start too few Squid will have to wait for them to
463# process a backlog of credential verifications, slowing it
464# down. When credential verifications are done via a (slow)
465# network you are likely to need lots of authenticator
466# processes.
467#
468# The startup= and idle= options permit some skew in the exact amount
469# run. A minimum of startup=N will begin during startup and reconfigure.
470# Squid will start more in groups of up to idle=N in an attempt to meet
471# traffic needs and to keep idle=N free above those traffic needs up to
472# the maximum.
473#
474# auth_param negotiate children 20 startup=0 idle=1
475#
476# "keep_alive" on|off
477# If you experience problems with PUT/POST requests when using the
478# Negotiate authentication scheme then you can try setting this to
479# off. This will cause Squid to forcibly close the connection on
480# the initial requests where the browser asks which schemes are
481# supported by the proxy.
482#
483# auth_param negotiate keep_alive on
484#
485#
486# Examples:
487#
488##Recommended minimum configuration per scheme:
489##auth_param negotiate program <uncomment and complete this line to activate>
490##auth_param negotiate children 20 startup=0 idle=1
491##auth_param negotiate keep_alive on
492##
493##auth_param ntlm program <uncomment and complete this line to activate>
494##auth_param ntlm children 20 startup=0 idle=1
495##auth_param ntlm keep_alive on
496##
497##auth_param digest program <uncomment and complete this line>
498##auth_param digest children 20 startup=0 idle=1
499##auth_param digest realm Squid proxy-caching web server
500##auth_param digest nonce_garbage_interval 5 minutes
501##auth_param digest nonce_max_duration 30 minutes
502##auth_param digest nonce_max_count 50
503##
504##auth_param basic program <uncomment and complete this line>
505##auth_param basic children 5 startup=5 idle=1
506##auth_param basic realm Squid proxy-caching web server
507##auth_param basic credentialsttl 2 hours
508#Default:
509# none
510
511# TAG: authenticate_cache_garbage_interval
512# The time period between garbage collection across the username cache.
513# This is a trade-off between memory utilization (long intervals - say
514# 2 days) and CPU (short intervals - say 1 minute). Only change if you
515# have good reason to.
516#Default:
517# authenticate_cache_garbage_interval 1 hour
518
519# TAG: authenticate_ttl
520# The time a user & their credentials stay in the logged in
521# user cache since their last request. When the garbage
522# interval passes, all user credentials that have passed their
523# TTL are removed from memory.
524#Default:
525# authenticate_ttl 1 hour
526
527# TAG: authenticate_ip_ttl
528# If you use proxy authentication and the 'max_user_ip' ACL,
529# this directive controls how long Squid remembers the IP
530# addresses associated with each user. Use a small value
531# (e.g., 60 seconds) if your users might change addresses
532# quickly, as is the case with dialup. You might be safe
533# using a larger value (e.g., 2 hours) in a corporate LAN
534# environment with relatively static address assignments.
535#Default:
536# authenticate_ip_ttl 0 seconds
537
538# ACCESS CONTROLS
539# -----------------------------------------------------------------------------
540
541# TAG: external_acl_type
542# This option defines external acl classes using a helper program
543# to look up the status
544#
545# external_acl_type name [options] FORMAT.. /path/to/helper [helper arguments..]
546#
547# Options:
548#
549# ttl=n TTL in seconds for cached results (defaults to 3600
550# for 1 hour)
551# negative_ttl=n
552# TTL for cached negative lookups (default same
553# as ttl)
554# children-max=n
555# Maximum number of acl helper processes spawned to service
556# external acl lookups of this type. (default 20)
557# children-startup=n
558# Minimum number of acl helper processes to spawn during
559# startup and reconfigure to service external acl lookups
560# of this type. (default 0)
561# children-idle=n
562# Number of acl helper processes to keep ahead of traffic
563# loads. Squid will spawn this many at once whenever load
564# rises above the capabilities of existing processes.
565# Up to the value of children-max. (default 1)
566# concurrency=n concurrency level per process. Only used with helpers
567# capable of processing more than one query at a time.
568# cache=n limit the result cache size, default is unbounded.
569# grace=n Percentage remaining of TTL where a refresh of a
570# cached entry should be initiated without needing to
571# wait for a new reply. (default is for no grace period)
572# protocol=2.5 Compatibility mode for Squid-2.5 external acl helpers
573# ipv4 / ipv6 IP protocol used to communicate with this helper.
574# The default is to auto-detect IPv6 and use it when available.
575#
576# FORMAT specifications
577#
578# %LOGIN Authenticated user login name
579# %EXT_USER Username from previous external acl
580# %EXT_LOG Log details from previous external acl
581# %EXT_TAG Tag from previous external acl
582# %IDENT Ident user name
583# %SRC Client IP
584# %SRCPORT Client source port
585# %URI Requested URI
586# %DST Requested host
587# %PROTO Requested protocol
588# %PORT Requested port
589# %PATH Requested URL path
590# %METHOD Request method
591# %MYADDR Squid interface address
592# %MYPORT Squid http_port number
593# %PATH Requested URL-path (including query-string if any)
594# %USER_CERT SSL User certificate in PEM format
595# %USER_CERTCHAIN SSL User certificate chain in PEM format
596# %USER_CERT_xx SSL User certificate subject attribute xx
597# %USER_CA_xx SSL User certificate issuer attribute xx
598#
599# %>{Header} HTTP request header "Header"
600# %>{Hdr:member}
601# HTTP request header "Hdr" list member "member"
602# %>{Hdr:;member}
603# HTTP request header list member using ; as
604# list separator. ; can be any non-alphanumeric
605# character.
606#
607# %<{Header} HTTP reply header "Header"
608# %<{Hdr:member}
609# HTTP reply header "Hdr" list member "member"
610# %<{Hdr:;member}
611# HTTP reply header list member using ; as
612# list separator. ; can be any non-alphanumeric
613# character.
614#
615# %ACL The name of the ACL being tested.
616# %DATA The ACL arguments. If not used then any arguments
617# is automatically added at the end of the line
618# sent to the helper.
619# NOTE: this will encode the arguments as one token,
620# whereas the default will pass each separately.
621#
622# %% The percent sign. Useful for helpers which need
623# an unchanging input format.
624#
625# In addition to the above, any string specified in the referencing
626# acl will also be included in the helper request line, after the
627# specified formats (see the "acl external" directive)
628#
629# The helper receives lines per the above format specification,
630# and returns lines starting with OK or ERR indicating the validity
631# of the request and optionally followed by additional keywords with
632# more details.
633#
634# General result syntax:
635#
636# OK/ERR keyword=value ...
637#
638# Defined keywords:
639#
640# user= The users name (login)
641# password= The users password (for login= cache_peer option)
642# message= Message describing the reason. Available as %o
643# in error pages
644# tag= Apply a tag to a request (for both ERR and OK results)
645# Only sets a tag, does not alter existing tags.
646# log= String to be logged in access.log. Available as
647# %ea in logformat specifications
648#
649# If protocol=3.0 (the default) then URL escaping is used to protect
650# each value in both requests and responses.
651#
652# If using protocol=2.5 then all values need to be enclosed in quotes
653# if they may contain whitespace, or the whitespace escaped using \.
654# And quotes or \ characters within the keyword value must be \ escaped.
655#
656# When using the concurrency= option the protocol is changed by
657# introducing a query channel tag infront of the request/response.
658# The query channel tag is a number between 0 and concurrency-1.
659#Default:
660# none
661
662# TAG: acl
663# Defining an Access List
664#
665# Every access list definition must begin with an aclname and acltype,
666# followed by either type-specific arguments or a quoted filename that
667# they are read from.
668#
669# acl aclname acltype argument ...
670# acl aclname acltype "file" ...
671#
672# When using "file", the file should contain one item per line.
673#
674# By default, regular expressions are CASE-SENSITIVE.
675# To make them case-insensitive, use the -i option. To return case-sensitive
676# use the +i option between patterns, or make a new ACL line without -i.
677#
678# Some acl types require suspending the current request in order
679# to access some external data source.
680# Those which do are marked with the tag [slow], those which
681# don't are marked as [fast].
682# See http://wiki.squid-cache.org/SquidFaq/SquidAcl
683# for further information
684#
685# ***** ACL TYPES AVAILABLE *****
686#
687# acl aclname src ip-address/mask ... # clients IP address [fast]
688# acl aclname src addr1-addr2/mask ... # range of addresses [fast]
689# acl aclname dst ip-address/mask ... # URL host's IP address [slow]
690# acl aclname localip ip-address/mask ... # IP address the client connected to [fast]
691#
692# acl aclname arp mac-address ... (xx:xx:xx:xx:xx:xx notation)
693# # The arp ACL requires the special configure option --enable-arp-acl.
694# # Furthermore, the ARP ACL code is not portable to all operating systems.
695# # It works on Linux, Solaris, Windows, FreeBSD, and some
696# # other *BSD variants.
697# # [fast]
698# #
699# # NOTE: Squid can only determine the MAC address for clients that are on
700# # the same subnet. If the client is on a different subnet,
701# # then Squid cannot find out its MAC address.
702#
703# acl aclname srcdomain .foo.com ...
704# # reverse lookup, from client IP [slow]
705# acl aclname dstdomain .foo.com ...
706# # Destination server from URL [fast]
707# acl aclname srcdom_regex [-i] \.foo\.com ...
708# # regex matching client name [slow]
709# acl aclname dstdom_regex [-i] \.foo\.com ...
710# # regex matching server [fast]
711# #
712# # For dstdomain and dstdom_regex a reverse lookup is tried if a IP
713# # based URL is used and no match is found. The name "none" is used
714# # if the reverse lookup fails.
715#
716# acl aclname src_as number ...
717# acl aclname dst_as number ...
718# # [fast]
719# # Except for access control, AS numbers can be used for
720# # routing of requests to specific caches. Here's an
721# # example for routing all requests for AS#1241 and only
722# # those to mycache.mydomain.net:
723# # acl asexample dst_as 1241
724# # cache_peer_access mycache.mydomain.net allow asexample
725# # cache_peer_access mycache_mydomain.net deny all
726#
727# acl aclname peername myPeer ...
728# # [fast]
729# # match against a named cache_peer entry
730# # set unique name= on cache_peer lines for reliable use.
731#
732# acl aclname time [day-abbrevs] [h1:m1-h2:m2]
733# # [fast]
734# # day-abbrevs:
735# # S - Sunday
736# # M - Monday
737# # T - Tuesday
738# # W - Wednesday
739# # H - Thursday
740# # F - Friday
741# # A - Saturday
742# # h1:m1 must be less than h2:m2
743#
744# acl aclname url_regex [-i] ^http:// ...
745# # regex matching on whole URL [fast]
746# acl aclname urllogin [-i] [^a-zA-Z0-9] ...
747# # regex matching on URL login field
748# acl aclname urlpath_regex [-i] \.gif$ ...
749# # regex matching on URL path [fast]
750#
751# acl aclname port 80 70 21 0-1024... # destination TCP port [fast]
752# # ranges are alloed
753# acl aclname localport 3128 ... # TCP port the client connected to [fast]
754# # NP: for interception mode this is usually '80'
755#
756# acl aclname myportname 3128 ... # http(s)_port name [fast]
757#
758# acl aclname proto HTTP FTP ... # request protocol [fast]
759#
760# acl aclname method GET POST ... # HTTP request method [fast]
761#
762# acl aclname http_status 200 301 500- 400-403 ...
763# # status code in reply [fast]
764#
765# acl aclname browser [-i] regexp ...
766# # pattern match on User-Agent header (see also req_header below) [fast]
767#
768# acl aclname referer_regex [-i] regexp ...
769# # pattern match on Referer header [fast]
770# # Referer is highly unreliable, so use with care
771#
772# acl aclname ident username ...
773# acl aclname ident_regex [-i] pattern ...
774# # string match on ident output [slow]
775# # use REQUIRED to accept any non-null ident.
776#
777# acl aclname proxy_auth [-i] username ...
778# acl aclname proxy_auth_regex [-i] pattern ...
779# # perform http authentication challenge to the client and match against
780# # supplied credentials [slow]
781# #
782# # takes a list of allowed usernames.
783# # use REQUIRED to accept any valid username.
784# #
785# # Will use proxy authentication in forward-proxy scenarios, and plain
786# # http authenticaiton in reverse-proxy scenarios
787# #
788# # NOTE: when a Proxy-Authentication header is sent but it is not
789# # needed during ACL checking the username is NOT logged
790# # in access.log.
791# #
792# # NOTE: proxy_auth requires a EXTERNAL authentication program
793# # to check username/password combinations (see
794# # auth_param directive).
795# #
796# # NOTE: proxy_auth can't be used in a transparent/intercepting proxy
797# # as the browser needs to be configured for using a proxy in order
798# # to respond to proxy authentication.
799#
800# acl aclname snmp_community string ...
801# # A community string to limit access to your SNMP Agent [fast]
802# # Example:
803# #
804# # acl snmppublic snmp_community public
805#
806# acl aclname maxconn number
807# # This will be matched when the client's IP address has
808# # more than <number> TCP connections established. [fast]
809# # NOTE: This only measures direct TCP links so X-Forwarded-For
810# # indirect clients are not counted.
811#
812# acl aclname max_user_ip [-s] number
813# # This will be matched when the user attempts to log in from more
814# # than <number> different ip addresses. The authenticate_ip_ttl
815# # parameter controls the timeout on the ip entries. [fast]
816# # If -s is specified the limit is strict, denying browsing
817# # from any further IP addresses until the ttl has expired. Without
818# # -s Squid will just annoy the user by "randomly" denying requests.
819# # (the counter is reset each time the limit is reached and a
820# # request is denied)
821# # NOTE: in acceleration mode or where there is mesh of child proxies,
822# # clients may appear to come from multiple addresses if they are
823# # going through proxy farms, so a limit of 1 may cause user problems.
824#
825# acl aclname random probability
826# # Pseudo-randomly match requests. Based on the probability given.
827# # Probability may be written as a decimal (0.333), fraction (1/3)
828# # or ratio of matches:non-matches (3:5).
829#
830# acl aclname req_mime_type [-i] mime-type ...
831# # regex match against the mime type of the request generated
832# # by the client. Can be used to detect file upload or some
833# # types HTTP tunneling requests [fast]
834# # NOTE: This does NOT match the reply. You cannot use this
835# # to match the returned file type.
836#
837# acl aclname req_header header-name [-i] any\.regex\.here
838# # regex match against any of the known request headers. May be
839# # thought of as a superset of "browser", "referer" and "mime-type"
840# # ACL [fast]
841#
842# acl aclname rep_mime_type [-i] mime-type ...
843# # regex match against the mime type of the reply received by
844# # squid. Can be used to detect file download or some
845# # types HTTP tunneling requests. [fast]
846# # NOTE: This has no effect in http_access rules. It only has
847# # effect in rules that affect the reply data stream such as
848# # http_reply_access.
849#
850# acl aclname rep_header header-name [-i] any\.regex\.here
851# # regex match against any of the known reply headers. May be
852# # thought of as a superset of "browser", "referer" and "mime-type"
853# # ACLs [fast]
854#
855# acl aclname external class_name [arguments...]
856# # external ACL lookup via a helper class defined by the
857# # external_acl_type directive [slow]
858#
859# acl aclname user_cert attribute values...
860# # match against attributes in a user SSL certificate
861# # attribute is one of DN/C/O/CN/L/ST [fast]
862#
863# acl aclname ca_cert attribute values...
864# # match against attributes a users issuing CA SSL certificate
865# # attribute is one of DN/C/O/CN/L/ST [fast]
866#
867# acl aclname ext_user username ...
868# acl aclname ext_user_regex [-i] pattern ...
869# # string match on username returned by external acl helper [slow]
870# # use REQUIRED to accept any non-null user name.
871#
872# acl aclname tag tagvalue ...
873# # string match on tag returned by external acl helper [slow]
874#
875# acl aclname hier_code codename ...
876# # string match against squid hierarchy code(s); [fast]
877# # e.g., DIRECT, PARENT_HIT, NONE, etc.
878# #
879# # NOTE: This has no effect in http_access rules. It only has
880# # effect in rules that affect the reply data stream such as
881# # http_reply_access.
882#
883#
884# Examples:
885# acl macaddress arp 09:00:2b:23:45:67
886# acl myexample dst_as 1241
887# acl password proxy_auth REQUIRED
888# acl fileupload req_mime_type -i ^multipart/form-data$
889# acl javascript rep_mime_type -i ^application/x-javascript$
890#
891#Default:
892# ACLs all, manager, localhost, and to_localhost are predefined.
893#
894#
895# Recommended minimum configuration:
896#
897
898# Example rule allowing access from your local networks.
899# Adapt to list your (internal) IP networks from where browsing
900# should be allowed
901acl localnet src 10.0.0.0/8 # RFC1918 possible internal network
902acl localnet src 172.16.0.0/12 # RFC1918 possible internal network
903acl localnet src 192.168.0.0/16 # RFC1918 possible internal network
904acl localnet src fc00::/7 # RFC 4193 local private network range
905acl localnet src fe80::/10 # RFC 4291 link-local (directly plugged) machines
906
907acl SSL_ports port 443
908acl Safe_ports port 80 # http
909acl Safe_ports port 21 # ftp
910acl Safe_ports port 443 # https
911acl Safe_ports port 70 # gopher
912acl Safe_ports port 210 # wais
913acl Safe_ports port 1025-65535 # unregistered ports
914acl Safe_ports port 280 # http-mgmt
915acl Safe_ports port 488 # gss-http
916acl Safe_ports port 591 # filemaker
917acl Safe_ports port 777 # multiling http
918acl CONNECT method CONNECT
919
920# TAG: follow_x_forwarded_for
921# Allowing or Denying the X-Forwarded-For header to be followed to
922# find the original source of a request.
923#
924# Requests may pass through a chain of several other proxies
925# before reaching us. The X-Forwarded-For header will contain a
926# comma-separated list of the IP addresses in the chain, with the
927# rightmost address being the most recent.
928#
929# If a request reaches us from a source that is allowed by this
930# configuration item, then we consult the X-Forwarded-For header
931# to see where that host received the request from. If the
932# X-Forwarded-For header contains multiple addresses, we continue
933# backtracking until we reach an address for which we are not allowed
934# to follow the X-Forwarded-For header, or until we reach the first
935# address in the list. For the purpose of ACL used in the
936# follow_x_forwarded_for directive the src ACL type always matches
937# the address we are testing and srcdomain matches its rDNS.
938#
939# The end result of this process is an IP address that we will
940# refer to as the indirect client address. This address may
941# be treated as the client address for access control, ICAP, delay
942# pools and logging, depending on the acl_uses_indirect_client,
943# icap_uses_indirect_client, delay_pool_uses_indirect_client,
944# log_uses_indirect_client and tproxy_uses_indirect_client options.
945#
946# This clause only supports fast acl types.
947# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
948#
949# SECURITY CONSIDERATIONS:
950#
951# Any host for which we follow the X-Forwarded-For header
952# can place incorrect information in the header, and Squid
953# will use the incorrect information as if it were the
954# source address of the request. This may enable remote
955# hosts to bypass any access control restrictions that are
956# based on the client's source addresses.
957#
958# For example:
959#
960# acl localhost src 127.0.0.1
961# acl my_other_proxy srcdomain .proxy.example.com
962# follow_x_forwarded_for allow localhost
963# follow_x_forwarded_for allow my_other_proxy
964#Default:
965# X-Forwarded-For header will be ignored.
966
967# TAG: acl_uses_indirect_client on|off
968# Controls whether the indirect client address
969# (see follow_x_forwarded_for) is used instead of the
970# direct client address in acl matching.
971#
972# NOTE: maxconn ACL considers direct TCP links and indirect
973# clients will always have zero. So no match.
974#Default:
975# acl_uses_indirect_client on
976
977# TAG: delay_pool_uses_indirect_client on|off
978# Controls whether the indirect client address
979# (see follow_x_forwarded_for) is used instead of the
980# direct client address in delay pools.
981#Default:
982# delay_pool_uses_indirect_client on
983
984# TAG: log_uses_indirect_client on|off
985# Controls whether the indirect client address
986# (see follow_x_forwarded_for) is used instead of the
987# direct client address in the access log.
988#Default:
989# log_uses_indirect_client on
990
991# TAG: tproxy_uses_indirect_client on|off
992# Controls whether the indirect client address
993# (see follow_x_forwarded_for) is used instead of the
994# direct client address when spoofing the outgoing client.
995#
996# This has no effect on requests arriving in non-tproxy
997# mode ports.
998#
999# SECURITY WARNING: Usage of this option is dangerous
1000# and should not be used trivially. Correct configuration
1001# of follow_x_forewarded_for with a limited set of trusted
1002# sources is required to prevent abuse of your proxy.
1003#Default:
1004# tproxy_uses_indirect_client off
1005
1006# TAG: http_access
1007# Allowing or Denying access based on defined access lists
1008#
1009# Access to the HTTP port:
1010# http_access allow|deny [!]aclname ...
1011#
1012# NOTE on default values:
1013#
1014# If there are no "access" lines present, the default is to deny
1015# the request.
1016#
1017# If none of the "access" lines cause a match, the default is the
1018# opposite of the last line in the list. If the last line was
1019# deny, the default is allow. Conversely, if the last line
1020# is allow, the default will be deny. For these reasons, it is a
1021# good idea to have an "deny all" entry at the end of your access
1022# lists to avoid potential confusion.
1023#
1024# This clause supports both fast and slow acl types.
1025# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1026#
1027#Default:
1028# Deny, unless rules exist in squid.conf.
1029#
1030
1031#
1032# Recommended minimum Access Permission configuration:
1033#
1034# Deny requests to certain unsafe ports
1035http_access deny !Safe_ports
1036
1037# Deny CONNECT to other than secure SSL ports
1038http_access deny CONNECT !SSL_ports
1039
1040# Only allow cachemgr access from localhost
1041http_access allow localhost manager
1042http_access deny manager
1043
1044# We strongly recommend the following be uncommented to protect innocent
1045# web applications running on the proxy server who think the only
1046# one who can access services on "localhost" is a local user
1047#http_access deny to_localhost
1048
1049#
1050# INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS
1051#
1052
1053# Example rule allowing access from your local networks.
1054# Adapt localnet in the ACL section to list your (internal) IP networks
1055# from where browsing should be allowed
1056#http_access allow localnet
1057http_access allow localhost
1058
1059# And finally deny all other access to this proxy
1060http_access allow all
1061
1062# TAG: adapted_http_access
1063# Allowing or Denying access based on defined access lists
1064#
1065# Essentially identical to http_access, but runs after redirectors
1066# and ICAP/eCAP adaptation. Allowing access control based on their
1067# output.
1068#
1069# If not set then only http_access is used.
1070#Default:
1071# Allow, unless rules exist in squid.conf.
1072
1073# TAG: http_reply_access
1074# Allow replies to client requests. This is complementary to http_access.
1075#
1076# http_reply_access allow|deny [!] aclname ...
1077#
1078# NOTE: if there are no access lines present, the default is to allow
1079# all replies.
1080#
1081# If none of the access lines cause a match the opposite of the
1082# last line will apply. Thus it is good practice to end the rules
1083# with an "allow all" or "deny all" entry.
1084#
1085# This clause supports both fast and slow acl types.
1086# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1087#Default:
1088# Allow, unless rules exist in squid.conf.
1089
1090# TAG: icp_access
1091# Allowing or Denying access to the ICP port based on defined
1092# access lists
1093#
1094# icp_access allow|deny [!]aclname ...
1095#
1096# NOTE: The default if no icp_access lines are present is to
1097# deny all traffic. This default may cause problems with peers
1098# using ICP.
1099#
1100# This clause only supports fast acl types.
1101# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1102#
1103## Allow ICP queries from local networks only
1104##icp_access allow localnet
1105##icp_access deny all
1106#Default:
1107# Deny, unless rules exist in squid.conf.
1108
1109# TAG: htcp_access
1110# Allowing or Denying access to the HTCP port based on defined
1111# access lists
1112#
1113# htcp_access allow|deny [!]aclname ...
1114#
1115# See also htcp_clr_access for details on access control for
1116# cache purge (CLR) HTCP messages.
1117#
1118# NOTE: The default if no htcp_access lines are present is to
1119# deny all traffic. This default may cause problems with peers
1120# using the htcp option.
1121#
1122# This clause only supports fast acl types.
1123# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1124#
1125## Allow HTCP queries from local networks only
1126##htcp_access allow localnet
1127##htcp_access deny all
1128#Default:
1129# Deny, unless rules exist in squid.conf.
1130
1131# TAG: htcp_clr_access
1132# Allowing or Denying access to purge content using HTCP based
1133# on defined access lists.
1134# See htcp_access for details on general HTCP access control.
1135#
1136# htcp_clr_access allow|deny [!]aclname ...
1137#
1138# This clause only supports fast acl types.
1139# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1140#
1141## Allow HTCP CLR requests from trusted peers
1142#acl htcp_clr_peer src 192.0.2.2 2001:DB8::2
1143#htcp_clr_access allow htcp_clr_peer
1144#htcp_clr_access deny all
1145#Default:
1146# Deny, unless rules exist in squid.conf.
1147
1148# TAG: miss_access
1149# Determins whether network access is permitted when satisfying a request.
1150#
1151# For example;
1152# to force your neighbors to use you as a sibling instead of
1153# a parent.
1154#
1155# acl localclients src 192.0.2.0/24 2001:DB8::a:0/64
1156# miss_access deny !localclients
1157# miss_access allow all
1158#
1159# This means only your local clients are allowed to fetch relayed/MISS
1160# replies from the network and all other clients can only fetch cached
1161# objects (HITs).
1162#
1163# The default for this setting allows all clients who passed the
1164# http_access rules to relay via this proxy.
1165#
1166# This clause only supports fast acl types.
1167# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1168#Default:
1169# Allow, unless rules exist in squid.conf.
1170
1171# TAG: ident_lookup_access
1172# A list of ACL elements which, if matched, cause an ident
1173# (RFC 931) lookup to be performed for this request. For
1174# example, you might choose to always perform ident lookups
1175# for your main multi-user Unix boxes, but not for your Macs
1176# and PCs. By default, ident lookups are not performed for
1177# any requests.
1178#
1179# To enable ident lookups for specific client addresses, you
1180# can follow this example:
1181#
1182# acl ident_aware_hosts src 198.168.1.0/24
1183# ident_lookup_access allow ident_aware_hosts
1184# ident_lookup_access deny all
1185#
1186# Only src type ACL checks are fully supported. A srcdomain
1187# ACL might work at times, but it will not always provide
1188# the correct result.
1189#
1190# This clause only supports fast acl types.
1191# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1192#Default:
1193# Unless rules exist in squid.conf, IDENT is not fetched.
1194
1195# TAG: reply_body_max_size size [acl acl...]
1196# This option specifies the maximum size of a reply body. It can be
1197# used to prevent users from downloading very large files, such as
1198# MP3's and movies. When the reply headers are received, the
1199# reply_body_max_size lines are processed, and the first line where
1200# all (if any) listed ACLs are true is used as the maximum body size
1201# for this reply.
1202#
1203# This size is checked twice. First when we get the reply headers,
1204# we check the content-length value. If the content length value exists
1205# and is larger than the allowed size, the request is denied and the
1206# user receives an error message that says "the request or reply
1207# is too large." If there is no content-length, and the reply
1208# size exceeds this limit, the client's connection is just closed
1209# and they will receive a partial reply.
1210#
1211# WARNING: downstream caches probably can not detect a partial reply
1212# if there is no content-length header, so they will cache
1213# partial responses and give them out as hits. You should NOT
1214# use this option if you have downstream caches.
1215#
1216# WARNING: A maximum size smaller than the size of squid's error messages
1217# will cause an infinite loop and crash squid. Ensure that the smallest
1218# non-zero value you use is greater that the maximum header size plus
1219# the size of your largest error page.
1220#
1221# If you set this parameter none (the default), there will be
1222# no limit imposed.
1223#
1224# Configuration Format is:
1225# reply_body_max_size SIZE UNITS [acl ...]
1226# ie.
1227# reply_body_max_size 10 MB
1228#
1229#Default:
1230# No limit is applied.
1231
1232# NETWORK OPTIONS
1233# -----------------------------------------------------------------------------
1234
1235# TAG: http_port
1236# Usage: port [mode] [options]
1237# hostname:port [mode] [options]
1238# 1.2.3.4:port [mode] [options]
1239#
1240# The socket addresses where Squid will listen for HTTP client
1241# requests. You may specify multiple socket addresses.
1242# There are three forms: port alone, hostname with port, and
1243# IP address with port. If you specify a hostname or IP
1244# address, Squid binds the socket to that specific
1245# address. Most likely, you do not need to bind to a specific
1246# address, so you can use the port number alone.
1247#
1248# If you are running Squid in accelerator mode, you
1249# probably want to listen on port 80 also, or instead.
1250#
1251# The -a command line option may be used to specify additional
1252# port(s) where Squid listens for proxy request. Such ports will
1253# be plain proxy ports with no options.
1254#
1255# You may specify multiple socket addresses on multiple lines.
1256#
1257# Modes:
1258#
1259# intercept Support for IP-Layer interception of
1260# outgoing requests without browser settings.
1261# NP: disables authentication and IPv6 on the port.
1262#
1263# tproxy Support Linux TPROXY for spoofing outgoing
1264# connections using the client IP address.
1265# NP: disables authentication and maybe IPv6 on the port.
1266#
1267# accel Accelerator / reverse proxy mode
1268#
1269# ssl-bump For each CONNECT request allowed by ssl_bump ACLs,
1270# establish secure connection with the client and with
1271# the server, decrypt HTTPS messages as they pass through
1272# Squid, and treat them as unencrypted HTTP messages,
1273# becoming the man-in-the-middle.
1274#
1275# The ssl_bump option is required to fully enable
1276# bumping of CONNECT requests.
1277#
1278# Omitting the mode flag causes default forward proxy mode to be used.
1279#
1280#
1281# Accelerator Mode Options:
1282#
1283# defaultsite=domainname
1284# What to use for the Host: header if it is not present
1285# in a request. Determines what site (not origin server)
1286# accelerators should consider the default.
1287#
1288# no-vhost Disable using HTTP/1.1 Host header for virtual domain support.
1289#
1290# protocol= Protocol to reconstruct accelerated requests with.
1291# Defaults to http for http_port and https for
1292# https_port
1293#
1294# vport Virtual host port support. Using the http_port number
1295# instead of the port passed on Host: headers.
1296#
1297# vport=NN Virtual host port support. Using the specified port
1298# number instead of the port passed on Host: headers.
1299#
1300# act-as-origin
1301# Act as if this Squid is the origin server.
1302# This currently means generate new Date: and Expires:
1303# headers on HIT instead of adding Age:.
1304#
1305# ignore-cc Ignore request Cache-Control headers.
1306#
1307# WARNING: This option violates HTTP specifications if
1308# used in non-accelerator setups.
1309#
1310# allow-direct Allow direct forwarding in accelerator mode. Normally
1311# accelerated requests are denied direct forwarding as if
1312# never_direct was used.
1313#
1314# WARNING: this option opens accelerator mode to security
1315# vulnerabilities usually only affecting in interception
1316# mode. Make sure to protect forwarding with suitable
1317# http_access rules when using this.
1318#
1319#
1320# SSL Bump Mode Options:
1321# In addition to these options ssl-bump requires TLS/SSL options.
1322#
1323# generate-host-certificates[=<on|off>]
1324# Dynamically create SSL server certificates for the
1325# destination hosts of bumped CONNECT requests.When
1326# enabled, the cert and key options are used to sign
1327# generated certificates. Otherwise generated
1328# certificate will be selfsigned.
1329# If there is a CA certificate lifetime of the generated
1330# certificate equals lifetime of the CA certificate. If
1331# generated certificate is selfsigned lifetime is three
1332# years.
1333# This option is enabled by default when ssl-bump is used.
1334# See the ssl-bump option above for more information.
1335#
1336# dynamic_cert_mem_cache_size=SIZE
1337# Approximate total RAM size spent on cached generated
1338# certificates. If set to zero, caching is disabled. The
1339# default value is 4MB.
1340#
1341# TLS / SSL Options:
1342#
1343# cert= Path to SSL certificate (PEM format).
1344#
1345# key= Path to SSL private key file (PEM format)
1346# if not specified, the certificate file is
1347# assumed to be a combined certificate and
1348# key file.
1349#
1350# version= The version of SSL/TLS supported
1351# 1 automatic (default)
1352# 2 SSLv2 only
1353# 3 SSLv3 only
1354# 4 TLSv1.0 only
1355# 5 TLSv1.1 only
1356# 6 TLSv1.2 only
1357#
1358# cipher= Colon separated list of supported ciphers.
1359# NOTE: some ciphers such as EDH ciphers depend on
1360# additional settings. If those settings are
1361# omitted the ciphers may be silently ignored
1362# by the OpenSSL library.
1363#
1364# options= Various SSL implementation options. The most important
1365# being:
1366# NO_SSLv2 Disallow the use of SSLv2
1367# NO_SSLv3 Disallow the use of SSLv3
1368# NO_TLSv1 Disallow the use of TLSv1.0
1369# NO_TLSv1_1 Disallow the use of TLSv1.1
1370# NO_TLSv1_2 Disallow the use of TLSv1.2
1371# SINGLE_DH_USE Always create a new key when using
1372# temporary/ephemeral DH key exchanges
1373# ALL Enable various bug workarounds
1374# suggested as "harmless" by OpenSSL
1375# Be warned that this reduces SSL/TLS
1376# strength to some attacks.
1377# See OpenSSL SSL_CTX_set_options documentation for a
1378# complete list of options.
1379#
1380# clientca= File containing the list of CAs to use when
1381# requesting a client certificate.
1382#
1383# cafile= File containing additional CA certificates to
1384# use when verifying client certificates. If unset
1385# clientca will be used.
1386#
1387# capath= Directory containing additional CA certificates
1388# and CRL lists to use when verifying client certificates.
1389#
1390# crlfile= File of additional CRL lists to use when verifying
1391# the client certificate, in addition to CRLs stored in
1392# the capath. Implies VERIFY_CRL flag below.
1393#
1394# dhparams= File containing DH parameters for temporary/ephemeral
1395# DH key exchanges. See OpenSSL documentation for details
1396# on how to create this file.
1397# WARNING: EDH ciphers will be silently disabled if this
1398# option is not set.
1399#
1400# sslflags= Various flags modifying the use of SSL:
1401# DELAYED_AUTH
1402# Don't request client certificates
1403# immediately, but wait until acl processing
1404# requires a certificate (not yet implemented).
1405# NO_DEFAULT_CA
1406# Don't use the default CA lists built in
1407# to OpenSSL.
1408# NO_SESSION_REUSE
1409# Don't allow for session reuse. Each connection
1410# will result in a new SSL session.
1411# VERIFY_CRL
1412# Verify CRL lists when accepting client
1413# certificates.
1414# VERIFY_CRL_ALL
1415# Verify CRL lists for all certificates in the
1416# client certificate chain.
1417#
1418# sslcontext= SSL session ID context identifier.
1419#
1420# Other Options:
1421#
1422# connection-auth[=on|off]
1423# use connection-auth=off to tell Squid to prevent
1424# forwarding Microsoft connection oriented authentication
1425# (NTLM, Negotiate and Kerberos)
1426#
1427# disable-pmtu-discovery=
1428# Control Path-MTU discovery usage:
1429# off lets OS decide on what to do (default).
1430# transparent disable PMTU discovery when transparent
1431# support is enabled.
1432# always disable always PMTU discovery.
1433#
1434# In many setups of transparently intercepting proxies
1435# Path-MTU discovery can not work on traffic towards the
1436# clients. This is the case when the intercepting device
1437# does not fully track connections and fails to forward
1438# ICMP must fragment messages to the cache server. If you
1439# have such setup and experience that certain clients
1440# sporadically hang or never complete requests set
1441# disable-pmtu-discovery option to 'transparent'.
1442#
1443# name= Specifies a internal name for the port. Defaults to
1444# the port specification (port or addr:port)
1445#
1446# tcpkeepalive[=idle,interval,timeout]
1447# Enable TCP keepalive probes of idle connections.
1448# In seconds; idle is the initial time before TCP starts
1449# probing the connection, interval how often to probe, and
1450# timeout the time before giving up.
1451#
1452# If you run Squid on a dual-homed machine with an internal
1453# and an external interface we recommend you to specify the
1454# internal address:port in http_port. This way Squid will only be
1455# visible on the internal address.
1456#
1457#
1458
1459# Squid normally listens to port 3128
1460http_port 20897
1461
1462# TAG: https_port
1463# Note: This option is only available if Squid is rebuilt with the
1464# --enable-ssl
1465#
1466# Usage: [ip:]port cert=certificate.pem [key=key.pem] [mode] [options...]
1467#
1468# The socket address where Squid will listen for client requests made
1469# over TLS or SSL connections. Commonly referred to as HTTPS.
1470#
1471# This is most useful for situations where you are running squid in
1472# accelerator mode and you want to do the SSL work at the accelerator level.
1473#
1474# You may specify multiple socket addresses on multiple lines,
1475# each with their own SSL certificate and/or options.
1476#
1477# Modes:
1478#
1479# accel Accelerator / reverse proxy mode
1480#
1481# intercept Support for IP-Layer interception of
1482# outgoing requests without browser settings.
1483# NP: disables authentication and IPv6 on the port.
1484#
1485# tproxy Support Linux TPROXY for spoofing outgoing
1486# connections using the client IP address.
1487# NP: disables authentication and maybe IPv6 on the port.
1488#
1489# ssl-bump For each intercepted connection allowed by ssl_bump
1490# ACLs, establish a secure connection with the client and with
1491# the server, decrypt HTTPS messages as they pass through
1492# Squid, and treat them as unencrypted HTTP messages,
1493# becoming the man-in-the-middle.
1494#
1495# An "ssl_bump server-first" match is required to
1496# fully enable bumping of intercepted SSL connections.
1497#
1498# Requires tproxy or intercept.
1499#
1500# Omitting the mode flag causes default forward proxy mode to be used.
1501#
1502#
1503# See http_port for a list of generic options
1504#
1505#
1506# SSL Options:
1507#
1508# cert= Path to SSL certificate (PEM format).
1509#
1510# key= Path to SSL private key file (PEM format)
1511# if not specified, the certificate file is
1512# assumed to be a combined certificate and
1513# key file.
1514#
1515# version= The version of SSL/TLS supported
1516# 1 automatic (default)
1517# 2 SSLv2 only
1518# 3 SSLv3 only
1519# 4 TLSv1 only
1520#
1521# cipher= Colon separated list of supported ciphers.
1522#
1523# options= Various SSL engine options. The most important
1524# being:
1525# NO_SSLv2 Disallow the use of SSLv2
1526# NO_SSLv3 Disallow the use of SSLv3
1527# NO_TLSv1 Disallow the use of TLSv1
1528# SINGLE_DH_USE Always create a new key when using
1529# temporary/ephemeral DH key exchanges
1530# See src/ssl_support.c or OpenSSL SSL_CTX_set_options
1531# documentation for a complete list of options.
1532#
1533# clientca= File containing the list of CAs to use when
1534# requesting a client certificate.
1535#
1536# cafile= File containing additional CA certificates to
1537# use when verifying client certificates. If unset
1538# clientca will be used.
1539#
1540# capath= Directory containing additional CA certificates
1541# and CRL lists to use when verifying client certificates.
1542#
1543# crlfile= File of additional CRL lists to use when verifying
1544# the client certificate, in addition to CRLs stored in
1545# the capath. Implies VERIFY_CRL flag below.
1546#
1547# dhparams= File containing DH parameters for temporary/ephemeral
1548# DH key exchanges.
1549#
1550# sslflags= Various flags modifying the use of SSL:
1551# DELAYED_AUTH
1552# Don't request client certificates
1553# immediately, but wait until acl processing
1554# requires a certificate (not yet implemented).
1555# NO_DEFAULT_CA
1556# Don't use the default CA lists built in
1557# to OpenSSL.
1558# NO_SESSION_REUSE
1559# Don't allow for session reuse. Each connection
1560# will result in a new SSL session.
1561# VERIFY_CRL
1562# Verify CRL lists when accepting client
1563# certificates.
1564# VERIFY_CRL_ALL
1565# Verify CRL lists for all certificates in the
1566# client certificate chain.
1567#
1568# sslcontext= SSL session ID context identifier.
1569#
1570# generate-host-certificates[=<on|off>]
1571# Dynamically create SSL server certificates for the
1572# destination hosts of bumped SSL requests.When
1573# enabled, the cert and key options are used to sign
1574# generated certificates. Otherwise generated
1575# certificate will be selfsigned.
1576# If there is CA certificate life time of generated
1577# certificate equals lifetime of CA certificate. If
1578# generated certificate is selfsigned lifetime is three
1579# years.
1580# This option is enabled by default when SslBump is used.
1581# See the sslBump option above for more information.
1582#
1583# dynamic_cert_mem_cache_size=SIZE
1584# Approximate total RAM size spent on cached generated
1585# certificates. If set to zero, caching is disabled. The
1586# default value is 4MB.
1587#
1588# See http_port for a list of available options.
1589#Default:
1590# none
1591
1592# TAG: tcp_outgoing_tos
1593# Allows you to select a TOS/Diffserv value for packets outgoing
1594# on the server side, based on an ACL.
1595#
1596# tcp_outgoing_tos ds-field [!]aclname ...
1597#
1598# Example where normal_service_net uses the TOS value 0x00
1599# and good_service_net uses 0x20
1600#
1601# acl normal_service_net src 10.0.0.0/24
1602# acl good_service_net src 10.0.1.0/24
1603# tcp_outgoing_tos 0x00 normal_service_net
1604# tcp_outgoing_tos 0x20 good_service_net
1605#
1606# TOS/DSCP values really only have local significance - so you should
1607# know what you're specifying. For more information, see RFC2474,
1608# RFC2475, and RFC3260.
1609#
1610# The TOS/DSCP byte must be exactly that - a octet value 0 - 255, or
1611# "default" to use whatever default your host has. Note that in
1612# practice often only multiples of 4 is usable as the two rightmost bits
1613# have been redefined for use by ECN (RFC 3168 section 23.1).
1614#
1615# Processing proceeds in the order specified, and stops at first fully
1616# matching line.
1617#Default:
1618# none
1619
1620# TAG: clientside_tos
1621# Allows you to select a TOS/Diffserv value for packets being transmitted
1622# on the client-side, based on an ACL.
1623#
1624# clientside_tos ds-field [!]aclname ...
1625#
1626# Example where normal_service_net uses the TOS value 0x00
1627# and good_service_net uses 0x20
1628#
1629# acl normal_service_net src 10.0.0.0/24
1630# acl good_service_net src 10.0.1.0/24
1631# clientside_tos 0x00 normal_service_net
1632# clientside_tos 0x20 good_service_net
1633#
1634# Note: This feature is incompatible with qos_flows. Any TOS values set here
1635# will be overwritten by TOS values in qos_flows.
1636#Default:
1637# none
1638
1639# TAG: tcp_outgoing_mark
1640# Note: This option is only available if Squid is rebuilt with the
1641# Packet MARK (Linux)
1642#
1643# Allows you to apply a Netfilter mark value to outgoing packets
1644# on the server side, based on an ACL.
1645#
1646# tcp_outgoing_mark mark-value [!]aclname ...
1647#
1648# Example where normal_service_net uses the mark value 0x00
1649# and good_service_net uses 0x20
1650#
1651# acl normal_service_net src 10.0.0.0/24
1652# acl good_service_net src 10.0.1.0/24
1653# tcp_outgoing_mark 0x00 normal_service_net
1654# tcp_outgoing_mark 0x20 good_service_net
1655#Default:
1656# none
1657
1658# TAG: clientside_mark
1659# Note: This option is only available if Squid is rebuilt with the
1660# Packet MARK (Linux)
1661#
1662# Allows you to apply a Netfilter mark value to packets being transmitted
1663# on the client-side, based on an ACL.
1664#
1665# clientside_mark mark-value [!]aclname ...
1666#
1667# Example where normal_service_net uses the mark value 0x00
1668# and good_service_net uses 0x20
1669#
1670# acl normal_service_net src 10.0.0.0/24
1671# acl good_service_net src 10.0.1.0/24
1672# clientside_mark 0x00 normal_service_net
1673# clientside_mark 0x20 good_service_net
1674#
1675# Note: This feature is incompatible with qos_flows. Any mark values set here
1676# will be overwritten by mark values in qos_flows.
1677#Default:
1678# none
1679
1680# TAG: qos_flows
1681# Allows you to select a TOS/DSCP value to mark outgoing
1682# connections with, based on where the reply was sourced. For
1683# platforms using netfilter, allows you to set a netfilter mark
1684# value instead of, or in addition to, a TOS value.
1685#
1686# TOS values really only have local significance - so you should
1687# know what you're specifying. For more information, see RFC2474,
1688# RFC2475, and RFC3260.
1689#
1690# The TOS/DSCP byte must be exactly that - a octet value 0 - 255. Note that
1691# in practice often only multiples of 4 is usable as the two rightmost bits
1692# have been redefined for use by ECN (RFC 3168 section 23.1).
1693#
1694# Mark values can be any unsigned 32-bit integer value.
1695#
1696# This setting is configured by setting the following values:
1697#
1698# tos|mark Whether to set TOS or netfilter mark values
1699#
1700# local-hit=0xFF Value to mark local cache hits.
1701#
1702# sibling-hit=0xFF Value to mark hits from sibling peers.
1703#
1704# parent-hit=0xFF Value to mark hits from parent peers.
1705#
1706# miss=0xFF[/mask] Value to mark cache misses. Takes precedence
1707# over the preserve-miss feature (see below), unless
1708# mask is specified, in which case only the bits
1709# specified in the mask are written.
1710#
1711# The TOS variant of the following features are only possible on Linux
1712# and require your kernel to be patched with the TOS preserving ZPH
1713# patch, available from http://zph.bratcheda.org
1714# No patch is needed to preserve the netfilter mark, which will work
1715# with all variants of netfilter.
1716#
1717# disable-preserve-miss
1718# This option disables the preservation of the TOS or netfilter
1719# mark. By default, the existing TOS or netfilter mark value of
1720# the response coming from the remote server will be retained
1721# and masked with miss-mark.
1722# NOTE: in the case of a netfilter mark, the mark must be set on
1723# the connection (using the CONNMARK target) not on the packet
1724# (MARK target).
1725#
1726# miss-mask=0xFF
1727# Allows you to mask certain bits in the TOS or mark value
1728# received from the remote server, before copying the value to
1729# the TOS sent towards clients.
1730# Default for tos: 0xFF (TOS from server is not changed).
1731# Default for mark: 0xFFFFFFFF (mark from server is not changed).
1732#
1733# All of these features require the --enable-zph-qos compilation flag
1734# (enabled by default). Netfilter marking also requires the
1735# libnetfilter_conntrack libraries (--with-netfilter-conntrack) and
1736# libcap 2.09+ (--with-libcap).
1737#
1738#Default:
1739# none
1740
1741# TAG: tcp_outgoing_address
1742# Allows you to map requests to different outgoing IP addresses
1743# based on the username or source address of the user making
1744# the request.
1745#
1746# tcp_outgoing_address ipaddr [[!]aclname] ...
1747#
1748# For example;
1749# Forwarding clients with dedicated IPs for certain subnets.
1750#
1751# acl normal_service_net src 10.0.0.0/24
1752# acl good_service_net src 10.0.2.0/24
1753#
1754# tcp_outgoing_address 2001:db8::c001 good_service_net
1755# tcp_outgoing_address 10.1.0.2 good_service_net
1756#
1757# tcp_outgoing_address 2001:db8::beef normal_service_net
1758# tcp_outgoing_address 10.1.0.1 normal_service_net
1759#
1760# tcp_outgoing_address 2001:db8::1
1761# tcp_outgoing_address 10.1.0.3
1762#
1763# Processing proceeds in the order specified, and stops at first fully
1764# matching line.
1765#
1766# Squid will add an implicit IP version test to each line.
1767# Requests going to IPv4 websites will use the outgoing 10.1.0.* addresses.
1768# Requests going to IPv6 websites will use the outgoing 2001:db8:* addresses.
1769#
1770#
1771# NOTE: The use of this directive using client dependent ACLs is
1772# incompatible with the use of server side persistent connections. To
1773# ensure correct results it is best to set server_persistent_connections
1774# to off when using this directive in such configurations.
1775#
1776# NOTE: The use of this directive to set a local IP on outgoing TCP links
1777# is incompatible with using TPROXY to set client IP out outbound TCP links.
1778# When needing to contact peers use the no-tproxy cache_peer option and the
1779# client_dst_passthru directive re-enable normal forwarding such as this.
1780#
1781#Default:
1782# Address selection is performed by the operating system.
1783
1784# TAG: host_verify_strict
1785# Regardless of this option setting, when dealing with intercepted
1786# traffic, Squid always verifies that the destination IP address matches
1787# the Host header domain or IP (called 'authority form URL').
1788#
1789# This enforcement is performed to satisfy a MUST-level requirement in
1790# RFC 2616 section 14.23: "The Host field value MUST represent the naming
1791# authority of the origin server or gateway given by the original URL".
1792#
1793# When set to ON:
1794# Squid always responds with an HTTP 409 (Conflict) error
1795# page and logs a security warning if there is no match.
1796#
1797# Squid verifies that the destination IP address matches
1798# the Host header for forward-proxy and reverse-proxy traffic
1799# as well. For those traffic types, Squid also enables the
1800# following checks, comparing the corresponding Host header
1801# and Request-URI components:
1802#
1803# * The host names (domain or IP) must be identical,
1804# but valueless or missing Host header disables all checks.
1805# For the two host names to match, both must be either IP
1806# or FQDN.
1807#
1808# * Port numbers must be identical, but if a port is missing
1809# the scheme-default port is assumed.
1810#
1811#
1812# When set to OFF (the default):
1813# Squid allows suspicious requests to continue but logs a
1814# security warning and blocks caching of the response.
1815#
1816# * Forward-proxy traffic is not checked at all.
1817#
1818# * Reverse-proxy traffic is not checked at all.
1819#
1820# * Intercepted traffic which passes verification is handled
1821# according to client_dst_passthru.
1822#
1823# * Intercepted requests which fail verification are sent
1824# to the client original destination instead of DIRECT.
1825# This overrides 'client_dst_passthru off'.
1826#
1827# For now suspicious intercepted CONNECT requests are always
1828# responded to with an HTTP 409 (Conflict) error page.
1829#
1830#
1831# SECURITY NOTE:
1832#
1833# As described in CVE-2009-0801 when the Host: header alone is used
1834# to determine the destination of a request it becomes trivial for
1835# malicious scripts on remote websites to bypass browser same-origin
1836# security policy and sandboxing protections.
1837#
1838# The cause of this is that such applets are allowed to perform their
1839# own HTTP stack, in which case the same-origin policy of the browser
1840# sandbox only verifies that the applet tries to contact the same IP
1841# as from where it was loaded at the IP level. The Host: header may
1842# be different from the connected IP and approved origin.
1843#
1844#Default:
1845# host_verify_strict off
1846
1847# TAG: client_dst_passthru
1848# With NAT or TPROXY intercepted traffic Squid may pass the request
1849# directly to the original client destination IP or seek a faster
1850# source using the HTTP Host header.
1851#
1852# Using Host to locate alternative servers can provide faster
1853# connectivity with a range of failure recovery options.
1854# But can also lead to connectivity trouble when the client and
1855# server are attempting stateful interactions unaware of the proxy.
1856#
1857# This option (on by default) prevents alternative DNS entries being
1858# located to send intercepted traffic DIRECT to an origin server.
1859# The clients original destination IP and port will be used instead.
1860#
1861# Regardless of this option setting, when dealing with intercepted
1862# traffic Squid will verify the Host: header and any traffic which
1863# fails Host verification will be treated as if this option were ON.
1864#
1865# see host_verify_strict for details on the verification process.
1866#Default:
1867# client_dst_passthru on
1868
1869# SSL OPTIONS
1870# -----------------------------------------------------------------------------
1871
1872# TAG: ssl_unclean_shutdown
1873# Note: This option is only available if Squid is rebuilt with the
1874# --enable-ssl
1875#
1876# Some browsers (especially MSIE) bugs out on SSL shutdown
1877# messages.
1878#Default:
1879# ssl_unclean_shutdown off
1880
1881# TAG: ssl_engine
1882# Note: This option is only available if Squid is rebuilt with the
1883# --enable-ssl
1884#
1885# The OpenSSL engine to use. You will need to set this if you
1886# would like to use hardware SSL acceleration for example.
1887#Default:
1888# none
1889
1890# TAG: sslproxy_client_certificate
1891# Note: This option is only available if Squid is rebuilt with the
1892# --enable-ssl
1893#
1894# Client SSL Certificate to use when proxying https:// URLs
1895#Default:
1896# none
1897
1898# TAG: sslproxy_client_key
1899# Note: This option is only available if Squid is rebuilt with the
1900# --enable-ssl
1901#
1902# Client SSL Key to use when proxying https:// URLs
1903#Default:
1904# none
1905
1906# TAG: sslproxy_version
1907# Note: This option is only available if Squid is rebuilt with the
1908# --enable-ssl
1909#
1910# SSL version level to use when proxying https:// URLs
1911#
1912# The versions of SSL/TLS supported:
1913#
1914# 1 automatic (default)
1915# 2 SSLv2 only
1916# 3 SSLv3 only
1917# 4 TLSv1.0 only
1918# 5 TLSv1.1 only
1919# 6 TLSv1.2 only
1920#Default:
1921# automatic SSL/TLS version negotiation
1922
1923# TAG: sslproxy_options
1924# Note: This option is only available if Squid is rebuilt with the
1925# --enable-ssl
1926#
1927# SSL implementation options to use when proxying https:// URLs
1928#
1929# The most important being:
1930#
1931# NO_SSLv2 Disallow the use of SSLv2
1932# NO_SSLv3 Disallow the use of SSLv3
1933# NO_TLSv1 Disallow the use of TLSv1.0
1934# NO_TLSv1_1 Disallow the use of TLSv1.1
1935# NO_TLSv1_2 Disallow the use of TLSv1.2
1936# SINGLE_DH_USE
1937# Always create a new key when using temporary/ephemeral
1938# DH key exchanges
1939# SSL_OP_NO_TICKET
1940# Disable use of RFC5077 session tickets. Some servers
1941# may have problems understanding the TLS extension due
1942# to ambiguous specification in RFC4507.
1943# ALL Enable various bug workarounds suggested as "harmless"
1944# by OpenSSL. Be warned that this may reduce SSL/TLS
1945# strength to some attacks.
1946#
1947# See the OpenSSL SSL_CTX_set_options documentation for a
1948# complete list of possible options.
1949#Default:
1950# none
1951
1952# TAG: sslproxy_cipher
1953# Note: This option is only available if Squid is rebuilt with the
1954# --enable-ssl
1955#
1956# SSL cipher list to use when proxying https:// URLs
1957#
1958# Colon separated list of supported ciphers.
1959#Default:
1960# none
1961
1962# TAG: sslproxy_cafile
1963# Note: This option is only available if Squid is rebuilt with the
1964# --enable-ssl
1965#
1966# file containing CA certificates to use when verifying server
1967# certificates while proxying https:// URLs
1968#Default:
1969# none
1970
1971# TAG: sslproxy_capath
1972# Note: This option is only available if Squid is rebuilt with the
1973# --enable-ssl
1974#
1975# directory containing CA certificates to use when verifying
1976# server certificates while proxying https:// URLs
1977#Default:
1978# none
1979
1980# TAG: ssl_bump
1981# Note: This option is only available if Squid is rebuilt with the
1982# --enable-ssl
1983#
1984# This option is consulted when a CONNECT request is received on
1985# an http_port (or a new connection is intercepted at an
1986# https_port), provided that port was configured with an ssl-bump
1987# flag. The subsequent data on the connection is either treated as
1988# HTTPS and decrypted OR tunneled at TCP level without decryption,
1989# depending on the first bumping "mode" which ACLs match.
1990#
1991# ssl_bump <mode> [!]acl ...
1992#
1993# The following bumping modes are supported:
1994#
1995# client-first
1996# Allow bumping of the connection. Establish a secure connection
1997# with the client first, then connect to the server. This old mode
1998# does not allow Squid to mimic server SSL certificate and does
1999# not work with intercepted SSL connections.
2000#
2001# server-first
2002# Allow bumping of the connection. Establish a secure connection
2003# with the server first, then establish a secure connection with
2004# the client, using a mimicked server certificate. Works with both
2005# CONNECT requests and intercepted SSL connections.
2006#
2007# none
2008# Become a TCP tunnel without decoding the connection.
2009# Works with both CONNECT requests and intercepted SSL
2010# connections. This is the default behavior when no
2011# ssl_bump option is given or no ssl_bump ACLs match.
2012#
2013# By default, no connections are bumped.
2014#
2015# The first matching ssl_bump option wins. If no ACLs match, the
2016# connection is not bumped. Unlike most allow/deny ACL lists, ssl_bump
2017# does not have an implicit "negate the last given option" rule. You
2018# must make that rule explicit if you convert old ssl_bump allow/deny
2019# rules that rely on such an implicit rule.
2020#
2021# This clause supports both fast and slow acl types.
2022# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
2023#
2024# See also: http_port ssl-bump, https_port ssl-bump
2025#
2026#
2027# # Example: Bump all requests except those originating from
2028# # localhost or those going to example.com.
2029#
2030# acl broken_sites dstdomain .example.com
2031# ssl_bump none localhost
2032# ssl_bump none broken_sites
2033# ssl_bump server-first all
2034#Default:
2035# Does not bump unless rules are present in squid.conf
2036
2037# TAG: sslproxy_flags
2038# Note: This option is only available if Squid is rebuilt with the
2039# --enable-ssl
2040#
2041# Various flags modifying the use of SSL while proxying https:// URLs:
2042# DONT_VERIFY_PEER Accept certificates that fail verification.
2043# For refined control, see sslproxy_cert_error.
2044# NO_DEFAULT_CA Don't use the default CA list built in
2045# to OpenSSL.
2046#Default:
2047# none
2048
2049# TAG: sslproxy_cert_error
2050# Note: This option is only available if Squid is rebuilt with the
2051# --enable-ssl
2052#
2053# Use this ACL to bypass server certificate validation errors.
2054#
2055# For example, the following lines will bypass all validation errors
2056# when talking to servers for example.com. All other
2057# validation errors will result in ERR_SECURE_CONNECT_FAIL error.
2058#
2059# acl BrokenButTrustedServers dstdomain example.com
2060# sslproxy_cert_error allow BrokenButTrustedServers
2061# sslproxy_cert_error deny all
2062#
2063# This clause only supports fast acl types.
2064# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
2065# Using slow acl types may result in server crashes
2066#
2067# Without this option, all server certificate validation errors
2068# terminate the transaction to protect Squid and the client.
2069#
2070# SECURITY WARNING:
2071# Bypassing validation errors is dangerous because an
2072# error usually implies that the server cannot be trusted
2073# and the connection may be insecure.
2074#
2075# See also: sslproxy_flags and DONT_VERIFY_PEER.
2076#Default:
2077# Server certificate errors terminate the transaction.
2078
2079# TAG: sslproxy_cert_sign
2080# Note: This option is only available if Squid is rebuilt with the
2081# --enable-ssl
2082#
2083#
2084# sslproxy_cert_sign <signing algorithm> acl ...
2085#
2086# The following certificate signing algorithms are supported:
2087#
2088# signTrusted
2089# Sign using the configured CA certificate which is usually
2090# placed in and trusted by end-user browsers. This is the
2091# default for trusted origin server certificates.
2092#
2093# signUntrusted
2094# Sign to guarantee an X509_V_ERR_CERT_UNTRUSTED browser error.
2095# This is the default for untrusted origin server certificates
2096# that are not self-signed (see ssl::certUntrusted).
2097#
2098# signSelf
2099# Sign using a self-signed certificate with the right CN to
2100# generate a X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT error in the
2101# browser. This is the default for self-signed origin server
2102# certificates (see ssl::certSelfSigned).
2103#
2104# This clause only supports fast acl types.
2105#
2106# When sslproxy_cert_sign acl(s) match, Squid uses the corresponding
2107# signing algorithm to generate the certificate and ignores all
2108# subsequent sslproxy_cert_sign options (the first match wins). If no
2109# acl(s) match, the default signing algorithm is determined by errors
2110# detected when obtaining and validating the origin server certificate.
2111#
2112# WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can
2113# be used with sslproxy_cert_adapt, but if and only if Squid is bumping a
2114# CONNECT request that carries a domain name. In all other cases (CONNECT
2115# to an IP address or an intercepted SSL connection), Squid cannot detect
2116# the domain mismatch at certificate generation time when
2117# bump-server-first is used.
2118#Default:
2119# none
2120
2121# TAG: sslproxy_cert_adapt
2122# Note: This option is only available if Squid is rebuilt with the
2123# --enable-ssl
2124#
2125#
2126# sslproxy_cert_adapt <adaptation algorithm> acl ...
2127#
2128# The following certificate adaptation algorithms are supported:
2129#
2130# setValidAfter
2131# Sets the "Not After" property to the "Not After" property of
2132# the CA certificate used to sign generated certificates.
2133#
2134# setValidBefore
2135# Sets the "Not Before" property to the "Not Before" property of
2136# the CA certificate used to sign generated certificates.
2137#
2138# setCommonName or setCommonName{CN}
2139# Sets Subject.CN property to the host name specified as a
2140# CN parameter or, if no explicit CN parameter was specified,
2141# extracted from the CONNECT request. It is a misconfiguration
2142# to use setCommonName without an explicit parameter for
2143# intercepted or tproxied SSL connections.
2144#
2145# This clause only supports fast acl types.
2146#
2147# Squid first groups sslproxy_cert_adapt options by adaptation algorithm.
2148# Within a group, when sslproxy_cert_adapt acl(s) match, Squid uses the
2149# corresponding adaptation algorithm to generate the certificate and
2150# ignores all subsequent sslproxy_cert_adapt options in that algorithm's
2151# group (i.e., the first match wins within each algorithm group). If no
2152# acl(s) match, the default mimicking action takes place.
2153#
2154# WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can
2155# be used with sslproxy_cert_adapt, but if and only if Squid is bumping a
2156# CONNECT request that carries a domain name. In all other cases (CONNECT
2157# to an IP address or an intercepted SSL connection), Squid cannot detect
2158# the domain mismatch at certificate generation time when
2159# bump-server-first is used.
2160#Default:
2161# none
2162
2163# TAG: sslpassword_program
2164# Note: This option is only available if Squid is rebuilt with the
2165# --enable-ssl
2166#
2167# Specify a program used for entering SSL key passphrases
2168# when using encrypted SSL certificate keys. If not specified
2169# keys must either be unencrypted, or Squid started with the -N
2170# option to allow it to query interactively for the passphrase.
2171#
2172# The key file name is given as argument to the program allowing
2173# selection of the right password if you have multiple encrypted
2174# keys.
2175#Default:
2176# none
2177
2178# OPTIONS RELATING TO EXTERNAL SSL_CRTD
2179# -----------------------------------------------------------------------------
2180
2181# TAG: sslcrtd_program
2182# Note: This option is only available if Squid is rebuilt with the
2183# --enable-ssl-crtd
2184#
2185# Specify the location and options of the executable for ssl_crtd process.
2186# /usr/lib/squid3/ssl_crtd program requires -s and -M parameters
2187# For more information use:
2188# /usr/lib/squid3/ssl_crtd -h
2189#Default:
2190# sslcrtd_program /usr/lib/squid3/ssl_crtd -s /var/lib/ssl_db -M 4MB
2191
2192# TAG: sslcrtd_children
2193# Note: This option is only available if Squid is rebuilt with the
2194# --enable-ssl-crtd
2195#
2196# The maximum number of processes spawn to service ssl server.
2197# The maximum this may be safely set to is 32.
2198#
2199# The startup= and idle= options allow some measure of skew in your
2200# tuning.
2201#
2202# startup=N
2203#
2204# Sets the minimum number of processes to spawn when Squid
2205# starts or reconfigures. When set to zero the first request will
2206# cause spawning of the first child process to handle it.
2207#
2208# Starting too few children temporary slows Squid under load while it
2209# tries to spawn enough additional processes to cope with traffic.
2210#
2211# idle=N
2212#
2213# Sets a minimum of how many processes Squid is to try and keep available
2214# at all times. When traffic begins to rise above what the existing
2215# processes can handle this many more will be spawned up to the maximum
2216# configured. A minimum setting of 1 is required.
2217#
2218# You must have at least one ssl_crtd process.
2219#Default:
2220# sslcrtd_children 32 startup=5 idle=1
2221
2222# OPTIONS WHICH AFFECT THE NEIGHBOR SELECTION ALGORITHM
2223# -----------------------------------------------------------------------------
2224
2225# TAG: cache_peer
2226# To specify other caches in a hierarchy, use the format:
2227#
2228# cache_peer hostname type http-port icp-port [options]
2229#
2230# For example,
2231#
2232# # proxy icp
2233# # hostname type port port options
2234# # -------------------- -------- ----- ----- -----------
2235# cache_peer parent.foo.net parent 3128 3130 default
2236# cache_peer sib1.foo.net sibling 3128 3130 proxy-only
2237# cache_peer sib2.foo.net sibling 3128 3130 proxy-only
2238# cache_peer example.com parent 80 0 default
2239# cache_peer cdn.example.com sibling 3128 0
2240#
2241# type: either 'parent', 'sibling', or 'multicast'.
2242#
2243# proxy-port: The port number where the peer accept HTTP requests.
2244# For other Squid proxies this is usually 3128
2245# For web servers this is usually 80
2246#
2247# icp-port: Used for querying neighbor caches about objects.
2248# Set to 0 if the peer does not support ICP or HTCP.
2249# See ICP and HTCP options below for additional details.
2250#
2251#
2252# ==== ICP OPTIONS ====
2253#
2254# You MUST also set icp_port and icp_access explicitly when using these options.
2255# The defaults will prevent peer traffic using ICP.
2256#
2257#
2258# no-query Disable ICP queries to this neighbor.
2259#
2260# multicast-responder
2261# Indicates the named peer is a member of a multicast group.
2262# ICP queries will not be sent directly to the peer, but ICP
2263# replies will be accepted from it.
2264#
2265# closest-only Indicates that, for ICP_OP_MISS replies, we'll only forward
2266# CLOSEST_PARENT_MISSes and never FIRST_PARENT_MISSes.
2267#
2268# background-ping
2269# To only send ICP queries to this neighbor infrequently.
2270# This is used to keep the neighbor round trip time updated
2271# and is usually used in conjunction with weighted-round-robin.
2272#
2273#
2274# ==== HTCP OPTIONS ====
2275#
2276# You MUST also set htcp_port and htcp_access explicitly when using these options.
2277# The defaults will prevent peer traffic using HTCP.
2278#
2279#
2280# htcp Send HTCP, instead of ICP, queries to the neighbor.
2281# You probably also want to set the "icp-port" to 4827
2282# instead of 3130. This directive accepts a comma separated
2283# list of options described below.
2284#
2285# htcp=oldsquid Send HTCP to old Squid versions (2.5 or earlier).
2286#
2287# htcp=no-clr Send HTCP to the neighbor but without
2288# sending any CLR requests. This cannot be used with
2289# only-clr.
2290#
2291# htcp=only-clr Send HTCP to the neighbor but ONLY CLR requests.
2292# This cannot be used with no-clr.
2293#
2294# htcp=no-purge-clr
2295# Send HTCP to the neighbor including CLRs but only when
2296# they do not result from PURGE requests.
2297#
2298# htcp=forward-clr
2299# Forward any HTCP CLR requests this proxy receives to the peer.
2300#
2301#
2302# ==== PEER SELECTION METHODS ====
2303#
2304# The default peer selection method is ICP, with the first responding peer
2305# being used as source. These options can be used for better load balancing.
2306#
2307#
2308# default This is a parent cache which can be used as a "last-resort"
2309# if a peer cannot be located by any of the peer-selection methods.
2310# If specified more than once, only the first is used.
2311#
2312# round-robin Load-Balance parents which should be used in a round-robin
2313# fashion in the absence of any ICP queries.
2314# weight=N can be used to add bias.
2315#
2316# weighted-round-robin
2317# Load-Balance parents which should be used in a round-robin
2318# fashion with the frequency of each parent being based on the
2319# round trip time. Closer parents are used more often.
2320# Usually used for background-ping parents.
2321# weight=N can be used to add bias.
2322#
2323# carp Load-Balance parents which should be used as a CARP array.
2324# The requests will be distributed among the parents based on the
2325# CARP load balancing hash function based on their weight.
2326#
2327# userhash Load-balance parents based on the client proxy_auth or ident username.
2328#
2329# sourcehash Load-balance parents based on the client source IP.
2330#
2331# multicast-siblings
2332# To be used only for cache peers of type "multicast".
2333# ALL members of this multicast group have "sibling"
2334# relationship with it, not "parent". This is to a multicast
2335# group when the requested object would be fetched only from
2336# a "parent" cache, anyway. It's useful, e.g., when
2337# configuring a pool of redundant Squid proxies, being
2338# members of the same multicast group.
2339#
2340#
2341# ==== PEER SELECTION OPTIONS ====
2342#
2343# weight=N use to affect the selection of a peer during any weighted
2344# peer-selection mechanisms.
2345# The weight must be an integer; default is 1,
2346# larger weights are favored more.
2347# This option does not affect parent selection if a peering
2348# protocol is not in use.
2349#
2350# basetime=N Specify a base amount to be subtracted from round trip
2351# times of parents.
2352# It is subtracted before division by weight in calculating
2353# which parent to fectch from. If the rtt is less than the
2354# base time the rtt is set to a minimal value.
2355#
2356# ttl=N Specify a TTL to use when sending multicast ICP queries
2357# to this address.
2358# Only useful when sending to a multicast group.
2359# Because we don't accept ICP replies from random
2360# hosts, you must configure other group members as
2361# peers with the 'multicast-responder' option.
2362#
2363# no-delay To prevent access to this neighbor from influencing the
2364# delay pools.
2365#
2366# digest-url=URL Tell Squid to fetch the cache digest (if digests are
2367# enabled) for this host from the specified URL rather
2368# than the Squid default location.
2369#
2370#
2371# ==== CARP OPTIONS ====
2372#
2373# carp-key=key-specification
2374# use a different key than the full URL to hash against the peer.
2375# the key-specification is a comma-separated list of the keywords
2376# scheme, host, port, path, params
2377# Order is not important.
2378#
2379# ==== ACCELERATOR / REVERSE-PROXY OPTIONS ====
2380#
2381# originserver Causes this parent to be contacted as an origin server.
2382# Meant to be used in accelerator setups when the peer
2383# is a web server.
2384#
2385# forceddomain=name
2386# Set the Host header of requests forwarded to this peer.
2387# Useful in accelerator setups where the server (peer)
2388# expects a certain domain name but clients may request
2389# others. ie example.com or www.example.com
2390#
2391# no-digest Disable request of cache digests.
2392#
2393# no-netdb-exchange
2394# Disables requesting ICMP RTT database (NetDB).
2395#
2396#
2397# ==== AUTHENTICATION OPTIONS ====
2398#
2399# login=user:password
2400# If this is a personal/workgroup proxy and your parent
2401# requires proxy authentication.
2402#
2403# Note: The string can include URL escapes (i.e. %20 for
2404# spaces). This also means % must be written as %%.
2405#
2406# login=PASSTHRU
2407# Send login details received from client to this peer.
2408# Both Proxy- and WWW-Authorization headers are passed
2409# without alteration to the peer.
2410# Authentication is not required by Squid for this to work.
2411#
2412# Note: This will pass any form of authentication but
2413# only Basic auth will work through a proxy unless the
2414# connection-auth options are also used.
2415#
2416# login=PASS Send login details received from client to this peer.
2417# Authentication is not required by this option.
2418#
2419# If there are no client-provided authentication headers
2420# to pass on, but username and password are available
2421# from an external ACL user= and password= result tags
2422# they may be sent instead.
2423#
2424# Note: To combine this with proxy_auth both proxies must
2425# share the same user database as HTTP only allows for
2426# a single login (one for proxy, one for origin server).
2427# Also be warned this will expose your users proxy
2428# password to the peer. USE WITH CAUTION
2429#
2430# login=*:password
2431# Send the username to the upstream cache, but with a
2432# fixed password. This is meant to be used when the peer
2433# is in another administrative domain, but it is still
2434# needed to identify each user.
2435# The star can optionally be followed by some extra
2436# information which is added to the username. This can
2437# be used to identify this proxy to the peer, similar to
2438# the login=username:password option above.
2439#
2440# login=NEGOTIATE
2441# If this is a personal/workgroup proxy and your parent
2442# requires a secure proxy authentication.
2443# The first principal from the default keytab or defined by
2444# the environment variable KRB5_KTNAME will be used.
2445#
2446# WARNING: The connection may transmit requests from multiple
2447# clients. Negotiate often assumes end-to-end authentication
2448# and a single-client. Which is not strictly true here.
2449#
2450# login=NEGOTIATE:principal_name
2451# If this is a personal/workgroup proxy and your parent
2452# requires a secure proxy authentication.
2453# The principal principal_name from the default keytab or
2454# defined by the environment variable KRB5_KTNAME will be
2455# used.
2456#
2457# WARNING: The connection may transmit requests from multiple
2458# clients. Negotiate often assumes end-to-end authentication
2459# and a single-client. Which is not strictly true here.
2460#
2461# connection-auth=on|off
2462# Tell Squid that this peer does or not support Microsoft
2463# connection oriented authentication, and any such
2464# challenges received from there should be ignored.
2465# Default is auto to automatically determine the status
2466# of the peer.
2467#
2468#
2469# ==== SSL / HTTPS / TLS OPTIONS ====
2470#
2471# ssl Encrypt connections to this peer with SSL/TLS.
2472#
2473# sslcert=/path/to/ssl/certificate
2474# A client SSL certificate to use when connecting to
2475# this peer.
2476#
2477# sslkey=/path/to/ssl/key
2478# The private SSL key corresponding to sslcert above.
2479# If 'sslkey' is not specified 'sslcert' is assumed to
2480# reference a combined file containing both the
2481# certificate and the key.
2482#
2483# Notes:
2484#
2485# On Debian/Ubuntu systems a default snakeoil certificate is
2486# available in /etc/ss and users can set:
2487#
2488# cert=/etc/ssl/certs/ssl-cert-snakeoil.pem
2489#
2490# and
2491#
2492# key=/etc/ssl/private/ssl-cert-snakeoil.key
2493#
2494# for testing.
2495#
2496# sslversion=1|2|3|4|5|6
2497# The SSL version to use when connecting to this peer
2498# 1 = automatic (default)
2499# 2 = SSL v2 only
2500# 3 = SSL v3 only
2501# 4 = TLS v1.0 only
2502# 5 = TLS v1.1 only
2503# 6 = TLS v1.2 only
2504#
2505# sslcipher=... The list of valid SSL ciphers to use when connecting
2506# to this peer.
2507#
2508# ssloptions=... Specify various SSL implementation options:
2509#
2510# NO_SSLv2 Disallow the use of SSLv2
2511# NO_SSLv3 Disallow the use of SSLv3
2512# NO_TLSv1 Disallow the use of TLSv1.0
2513# NO_TLSv1_1 Disallow the use of TLSv1.1
2514# NO_TLSv1_2 Disallow the use of TLSv1.2
2515# SINGLE_DH_USE
2516# Always create a new key when using
2517# temporary/ephemeral DH key exchanges
2518# ALL Enable various bug workarounds
2519# suggested as "harmless" by OpenSSL
2520# Be warned that this reduces SSL/TLS
2521# strength to some attacks.
2522#
2523# See the OpenSSL SSL_CTX_set_options documentation for a
2524# more complete list.
2525#
2526# sslcafile=... A file containing additional CA certificates to use
2527# when verifying the peer certificate.
2528#
2529# sslcapath=... A directory containing additional CA certificates to
2530# use when verifying the peer certificate.
2531#
2532# sslcrlfile=... A certificate revocation list file to use when
2533# verifying the peer certificate.
2534#
2535# sslflags=... Specify various flags modifying the SSL implementation:
2536#
2537# DONT_VERIFY_PEER
2538# Accept certificates even if they fail to
2539# verify.
2540# NO_DEFAULT_CA
2541# Don't use the default CA list built in
2542# to OpenSSL.
2543# DONT_VERIFY_DOMAIN
2544# Don't verify the peer certificate
2545# matches the server name
2546#
2547# ssldomain= The peer name as advertised in it's certificate.
2548# Used for verifying the correctness of the received peer
2549# certificate. If not specified the peer hostname will be
2550# used.
2551#
2552# front-end-https
2553# Enable the "Front-End-Https: On" header needed when
2554# using Squid as a SSL frontend in front of Microsoft OWA.
2555# See MS KB document Q307347 for details on this header.
2556# If set to auto the header will only be added if the
2557# request is forwarded as a https:// URL.
2558#
2559#
2560# ==== GENERAL OPTIONS ====
2561#
2562# connect-timeout=N
2563# A peer-specific connect timeout.
2564# Also see the peer_connect_timeout directive.
2565#
2566# connect-fail-limit=N
2567# How many times connecting to a peer must fail before
2568# it is marked as down. Default is 10.
2569#
2570# allow-miss Disable Squid's use of only-if-cached when forwarding
2571# requests to siblings. This is primarily useful when
2572# icp_hit_stale is used by the sibling. To extensive use
2573# of this option may result in forwarding loops, and you
2574# should avoid having two-way peerings with this option.
2575# For example to deny peer usage on requests from peer
2576# by denying cache_peer_access if the source is a peer.
2577#
2578# max-conn=N Limit the amount of connections Squid may open to this
2579# peer. see also
2580#
2581# name=xxx Unique name for the peer.
2582# Required if you have multiple peers on the same host
2583# but different ports.
2584# This name can be used in cache_peer_access and similar
2585# directives to dentify the peer.
2586# Can be used by outgoing access controls through the
2587# peername ACL type.
2588#
2589# no-tproxy Do not use the client-spoof TPROXY support when forwarding
2590# requests to this peer. Use normal address selection instead.
2591#
2592# proxy-only objects fetched from the peer will not be stored locally.
2593#
2594#Default:
2595# none
2596
2597# TAG: cache_peer_domain
2598# Use to limit the domains for which a neighbor cache will be
2599# queried.
2600#
2601# Usage:
2602# cache_peer_domain cache-host domain [domain ...]
2603# cache_peer_domain cache-host !domain
2604#
2605# For example, specifying
2606#
2607# cache_peer_domain parent.foo.net .edu
2608#
2609# has the effect such that UDP query packets are sent to
2610# 'bigserver' only when the requested object exists on a
2611# server in the .edu domain. Prefixing the domainname
2612# with '!' means the cache will be queried for objects
2613# NOT in that domain.
2614#
2615# NOTE: * Any number of domains may be given for a cache-host,
2616# either on the same or separate lines.
2617# * When multiple domains are given for a particular
2618# cache-host, the first matched domain is applied.
2619# * Cache hosts with no domain restrictions are queried
2620# for all requests.
2621# * There are no defaults.
2622# * There is also a 'cache_peer_access' tag in the ACL
2623# section.
2624#Default:
2625# none
2626
2627# TAG: cache_peer_access
2628# Similar to 'cache_peer_domain' but provides more flexibility by
2629# using ACL elements.
2630#
2631# Usage:
2632# cache_peer_access cache-host allow|deny [!]aclname ...
2633#
2634# The syntax is identical to 'http_access' and the other lists of
2635# ACL elements. See the comments for 'http_access' below, or
2636# the Squid FAQ (http://wiki.squid-cache.org/SquidFaq/SquidAcl).
2637#Default:
2638# none
2639
2640# TAG: neighbor_type_domain
2641# Modify the cache_peer neighbor type when passing requests
2642# about specific domains to the peer.
2643#
2644# Usage:
2645# neighbor_type_domain neighbor parent|sibling domain domain ...
2646#
2647# For example:
2648# cache_peer foo.example.com parent 3128 3130
2649# neighbor_type_domain foo.example.com sibling .au .de
2650#
2651# The above configuration treats all requests to foo.example.com as a
2652# parent proxy unless the request is for a .au or .de ccTLD domain name.
2653#Default:
2654# The peer type from cache_peer directive is used for all requests to that peer.
2655
2656# TAG: dead_peer_timeout (seconds)
2657# This controls how long Squid waits to declare a peer cache
2658# as "dead." If there are no ICP replies received in this
2659# amount of time, Squid will declare the peer dead and not
2660# expect to receive any further ICP replies. However, it
2661# continues to send ICP queries, and will mark the peer as
2662# alive upon receipt of the first subsequent ICP reply.
2663#
2664# This timeout also affects when Squid expects to receive ICP
2665# replies from peers. If more than 'dead_peer' seconds have
2666# passed since the last ICP reply was received, Squid will not
2667# expect to receive an ICP reply on the next query. Thus, if
2668# your time between requests is greater than this timeout, you
2669# will see a lot of requests sent DIRECT to origin servers
2670# instead of to your parents.
2671#Default:
2672# dead_peer_timeout 10 seconds
2673
2674# TAG: forward_max_tries
2675# Controls how many different forward paths Squid will try
2676# before giving up. See also forward_timeout.
2677#
2678# NOTE: connect_retries (default: none) can make each of these
2679# possible forwarding paths be tried multiple times.
2680#Default:
2681# forward_max_tries 25
2682
2683# TAG: hierarchy_stoplist
2684# A list of words which, if found in a URL, cause the object to
2685# be handled directly by this cache. In other words, use this
2686# to not query neighbor caches for certain objects. You may
2687# list this option multiple times.
2688#
2689# Example:
2690# hierarchy_stoplist cgi-bin ?
2691#
2692# Note: never_direct overrides this option.
2693#Default:
2694# none
2695
2696# MEMORY CACHE OPTIONS
2697# -----------------------------------------------------------------------------
2698
2699# TAG: cache_mem (bytes)
2700# NOTE: THIS PARAMETER DOES NOT SPECIFY THE MAXIMUM PROCESS SIZE.
2701# IT ONLY PLACES A LIMIT ON HOW MUCH ADDITIONAL MEMORY SQUID WILL
2702# USE AS A MEMORY CACHE OF OBJECTS. SQUID USES MEMORY FOR OTHER
2703# THINGS AS WELL. SEE THE SQUID FAQ SECTION 8 FOR DETAILS.
2704#
2705# 'cache_mem' specifies the ideal amount of memory to be used
2706# for:
2707# * In-Transit objects
2708# * Hot Objects
2709# * Negative-Cached objects
2710#
2711# Data for these objects are stored in 4 KB blocks. This
2712# parameter specifies the ideal upper limit on the total size of
2713# 4 KB blocks allocated. In-Transit objects take the highest
2714# priority.
2715#
2716# In-transit objects have priority over the others. When
2717# additional space is needed for incoming data, negative-cached
2718# and hot objects will be released. In other words, the
2719# negative-cached and hot objects will fill up any unused space
2720# not needed for in-transit objects.
2721#
2722# If circumstances require, this limit will be exceeded.
2723# Specifically, if your incoming request rate requires more than
2724# 'cache_mem' of memory to hold in-transit objects, Squid will
2725# exceed this limit to satisfy the new requests. When the load
2726# decreases, blocks will be freed until the high-water mark is
2727# reached. Thereafter, blocks will be used to store hot
2728# objects.
2729#
2730# If shared memory caching is enabled, Squid does not use the shared
2731# cache space for in-transit objects, but they still consume as much
2732# local memory as they need. For more details about the shared memory
2733# cache, see memory_cache_shared.
2734#Default:
2735# cache_mem 256 MB
2736
2737# TAG: maximum_object_size_in_memory (bytes)
2738# Objects greater than this size will not be attempted to kept in
2739# the memory cache. This should be set high enough to keep objects
2740# accessed frequently in memory to improve performance whilst low
2741# enough to keep larger objects from hoarding cache_mem.
2742#Default:
2743# maximum_object_size_in_memory 512 KB
2744
2745# TAG: memory_cache_shared on|off
2746# Controls whether the memory cache is shared among SMP workers.
2747#
2748# The shared memory cache is meant to occupy cache_mem bytes and replace
2749# the non-shared memory cache, although some entities may still be
2750# cached locally by workers for now (e.g., internal and in-transit
2751# objects may be served from a local memory cache even if shared memory
2752# caching is enabled).
2753#
2754# By default, the memory cache is shared if and only if all of the
2755# following conditions are satisfied: Squid runs in SMP mode with
2756# multiple workers, cache_mem is positive, and Squid environment
2757# supports required IPC primitives (e.g., POSIX shared memory segments
2758# and GCC-style atomic operations).
2759#
2760# To avoid blocking locks, shared memory uses opportunistic algorithms
2761# that do not guarantee that every cachable entity that could have been
2762# shared among SMP workers will actually be shared.
2763#
2764# Currently, entities exceeding 32KB in size cannot be shared.
2765#Default:
2766# "on" where supported if doing memory caching with multiple SMP workers.
2767
2768# TAG: memory_cache_mode
2769# Controls which objects to keep in the memory cache (cache_mem)
2770#
2771# always Keep most recently fetched objects in memory (default)
2772#
2773# disk Only disk cache hits are kept in memory, which means
2774# an object must first be cached on disk and then hit
2775# a second time before cached in memory.
2776#
2777# network Only objects fetched from network is kept in memory
2778#Default:
2779# Keep the most recently fetched objects in memory
2780
2781# TAG: memory_replacement_policy
2782# The memory replacement policy parameter determines which
2783# objects are purged from memory when memory space is needed.
2784#
2785# See cache_replacement_policy for details on algorithms.
2786#Default:
2787# memory_replacement_policy lru
2788
2789# DISK CACHE OPTIONS
2790# -----------------------------------------------------------------------------
2791
2792# TAG: cache_replacement_policy
2793# The cache replacement policy parameter determines which
2794# objects are evicted (replaced) when disk space is needed.
2795#
2796# lru : Squid's original list based LRU policy
2797# heap GDSF : Greedy-Dual Size Frequency
2798# heap LFUDA: Least Frequently Used with Dynamic Aging
2799# heap LRU : LRU policy implemented using a heap
2800#
2801# Applies to any cache_dir lines listed below this directive.
2802#
2803# The LRU policies keeps recently referenced objects.
2804#
2805# The heap GDSF policy optimizes object hit rate by keeping smaller
2806# popular objects in cache so it has a better chance of getting a
2807# hit. It achieves a lower byte hit rate than LFUDA though since
2808# it evicts larger (possibly popular) objects.
2809#
2810# The heap LFUDA policy keeps popular objects in cache regardless of
2811# their size and thus optimizes byte hit rate at the expense of
2812# hit rate since one large, popular object will prevent many
2813# smaller, slightly less popular objects from being cached.
2814#
2815# Both policies utilize a dynamic aging mechanism that prevents
2816# cache pollution that can otherwise occur with frequency-based
2817# replacement policies.
2818#
2819# NOTE: if using the LFUDA replacement policy you should increase
2820# the value of maximum_object_size above its default of 4 MB to
2821# to maximize the potential byte hit rate improvement of LFUDA.
2822#
2823# For more information about the GDSF and LFUDA cache replacement
2824# policies see http://www.hpl.hp.com/techreports/1999/HPL-1999-69.html
2825# and http://fog.hpl.external.hp.com/techreports/98/HPL-98-173.html.
2826#Default:
2827# cache_replacement_policy lru
2828
2829# TAG: cache_dir
2830# Format:
2831# cache_dir Type Directory-Name Fs-specific-data [options]
2832#
2833# You can specify multiple cache_dir lines to spread the
2834# cache among different disk partitions.
2835#
2836# Type specifies the kind of storage system to use. Only "ufs"
2837# is built by default. To enable any of the other storage systems
2838# see the --enable-storeio configure option.
2839#
2840# 'Directory' is a top-level directory where cache swap
2841# files will be stored. If you want to use an entire disk
2842# for caching, this can be the mount-point directory.
2843# The directory must exist and be writable by the Squid
2844# process. Squid will NOT create this directory for you.
2845#
2846# In SMP configurations, cache_dir must not precede the workers option
2847# and should use configuration macros or conditionals to give each
2848# worker interested in disk caching a dedicated cache directory.
2849#
2850#
2851# ==== The ufs store type ====
2852#
2853# "ufs" is the old well-known Squid storage format that has always
2854# been there.
2855#
2856# Usage:
2857# cache_dir ufs Directory-Name Mbytes L1 L2 [options]
2858#
2859# 'Mbytes' is the amount of disk space (MB) to use under this
2860# directory. The default is 100 MB. Change this to suit your
2861# configuration. Do NOT put the size of your disk drive here.
2862# Instead, if you want Squid to use the entire disk drive,
2863# subtract 20% and use that value.
2864#
2865# 'L1' is the number of first-level subdirectories which
2866# will be created under the 'Directory'. The default is 16.
2867#
2868# 'L2' is the number of second-level subdirectories which
2869# will be created under each first-level directory. The default
2870# is 256.
2871#
2872#
2873# ==== The aufs store type ====
2874#
2875# "aufs" uses the same storage format as "ufs", utilizing
2876# POSIX-threads to avoid blocking the main Squid process on
2877# disk-I/O. This was formerly known in Squid as async-io.
2878#
2879# Usage:
2880# cache_dir aufs Directory-Name Mbytes L1 L2 [options]
2881#
2882# see argument descriptions under ufs above
2883#
2884#
2885# ==== The diskd store type ====
2886#
2887# "diskd" uses the same storage format as "ufs", utilizing a
2888# separate process to avoid blocking the main Squid process on
2889# disk-I/O.
2890#
2891# Usage:
2892# cache_dir diskd Directory-Name Mbytes L1 L2 [options] [Q1=n] [Q2=n]
2893#
2894# see argument descriptions under ufs above
2895#
2896# Q1 specifies the number of unacknowledged I/O requests when Squid
2897# stops opening new files. If this many messages are in the queues,
2898# Squid won't open new files. Default is 64
2899#
2900# Q2 specifies the number of unacknowledged messages when Squid
2901# starts blocking. If this many messages are in the queues,
2902# Squid blocks until it receives some replies. Default is 72
2903#
2904# When Q1 < Q2 (the default), the cache directory is optimized
2905# for lower response time at the expense of a decrease in hit
2906# ratio. If Q1 > Q2, the cache directory is optimized for
2907# higher hit ratio at the expense of an increase in response
2908# time.
2909#
2910#
2911# ==== The rock store type ====
2912#
2913# Usage:
2914# cache_dir rock Directory-Name Mbytes <max-size=bytes> [options]
2915#
2916# The Rock Store type is a database-style storage. All cached
2917# entries are stored in a "database" file, using fixed-size slots,
2918# one entry per slot. The database size is specified in MB. The
2919# slot size is specified in bytes using the max-size option. See
2920# below for more info on the max-size option.
2921#
2922# If possible, Squid using Rock Store creates a dedicated kid
2923# process called "disker" to avoid blocking Squid worker(s) on disk
2924# I/O. One disker kid is created for each rock cache_dir. Diskers
2925# are created only when Squid, running in daemon mode, has support
2926# for the IpcIo disk I/O module.
2927#
2928# swap-timeout=msec: Squid will not start writing a miss to or
2929# reading a hit from disk if it estimates that the swap operation
2930# will take more than the specified number of milliseconds. By
2931# default and when set to zero, disables the disk I/O time limit
2932# enforcement. Ignored when using blocking I/O module because
2933# blocking synchronous I/O does not allow Squid to estimate the
2934# expected swap wait time.
2935#
2936# max-swap-rate=swaps/sec: Artificially limits disk access using
2937# the specified I/O rate limit. Swap out requests that
2938# would cause the average I/O rate to exceed the limit are
2939# delayed. Individual swap in requests (i.e., hits or reads) are
2940# not delayed, but they do contribute to measured swap rate and
2941# since they are placed in the same FIFO queue as swap out
2942# requests, they may wait longer if max-swap-rate is smaller.
2943# This is necessary on file systems that buffer "too
2944# many" writes and then start blocking Squid and other processes
2945# while committing those writes to disk. Usually used together
2946# with swap-timeout to avoid excessive delays and queue overflows
2947# when disk demand exceeds available disk "bandwidth". By default
2948# and when set to zero, disables the disk I/O rate limit
2949# enforcement. Currently supported by IpcIo module only.
2950#
2951#
2952# ==== The coss store type ====
2953#
2954# NP: COSS filesystem in Squid-3 has been deemed too unstable for
2955# production use and has thus been removed from this release.
2956# We hope that it can be made usable again soon.
2957#
2958# block-size=n defines the "block size" for COSS cache_dir's.
2959# Squid uses file numbers as block numbers. Since file numbers
2960# are limited to 24 bits, the block size determines the maximum
2961# size of the COSS partition. The default is 512 bytes, which
2962# leads to a maximum cache_dir size of 512<<24, or 8 GB. Note
2963# you should not change the coss block size after Squid
2964# has written some objects to the cache_dir.
2965#
2966# The coss file store has changed from 2.5. Now it uses a file
2967# called 'stripe' in the directory names in the config - and
2968# this will be created by squid -z.
2969#
2970#
2971# ==== COMMON OPTIONS ====
2972#
2973# no-store no new objects should be stored to this cache_dir.
2974#
2975# min-size=n the minimum object size in bytes this cache_dir
2976# will accept. It's used to restrict a cache_dir
2977# to only store large objects (e.g. AUFS) while
2978# other stores are optimized for smaller objects
2979# (e.g. COSS).
2980# Defaults to 0.
2981#
2982# max-size=n the maximum object size in bytes this cache_dir
2983# supports.
2984# The value in maximum_object_size directive, sets
2985# a default unless more specific details are available
2986# about the cache_dir (ie a small store capacity).
2987#
2988# Note: To make optimal use of the max-size limits you should order
2989# the cache_dir lines with the smallest max-size value first.
2990#
2991# Note for coss, max-size must be less than COSS_MEMBUF_SZ,
2992# which can be changed with the --with-coss-membuf-size=N configure
2993# option.
2994#
2995#Default:
2996# No disk cache. Store cache ojects only in memory.
2997#
2998
2999# Uncomment and adjust the following to add a disk cache directory.
3000#cache_dir ufs /var/spool/squid3 100 16 256
3001
3002# TAG: store_dir_select_algorithm
3003# How Squid selects which cache_dir to use when the response
3004# object will fit into more than one.
3005#
3006# Regardless of which algorithm is used the cache_dir min-size
3007# and max-size parameters are obeyed. As such they can affect
3008# the selection algorithm by limiting the set of considered
3009# cache_dir.
3010#
3011# Algorithms:
3012#
3013# least-load
3014#
3015# This algorithm is suited to caches with similar cache_dir
3016# sizes and disk speeds.
3017#
3018# The disk with the least I/O pending is selected.
3019# When there are multiple disks with the same I/O load ranking
3020# the cache_dir with most available capacity is selected.
3021#
3022# When a mix of cache_dir sizes are configured the faster disks
3023# have a naturally lower I/O loading and larger disks have more
3024# capacity. So space used to store objects and data throughput
3025# may be very unbalanced towards larger disks.
3026#
3027#
3028# round-robin
3029#
3030# This algorithm is suited to caches with unequal cache_dir
3031# disk sizes.
3032#
3033# Each cache_dir is selected in a rotation. The next suitable
3034# cache_dir is used.
3035#
3036# Available cache_dir capacity is only considered in relation
3037# to whether the object will fit and meets the min-size and
3038# max-size parameters.
3039#
3040# Disk I/O loading is only considered to prevent overload on slow
3041# disks. This algorithm does not spread objects by size, so any
3042# I/O loading per-disk may appear very unbalanced and volatile.
3043#
3044#Default:
3045# store_dir_select_algorithm least-load
3046
3047# TAG: max_open_disk_fds
3048# To avoid having disk as the I/O bottleneck Squid can optionally
3049# bypass the on-disk cache if more than this amount of disk file
3050# descriptors are open.
3051#
3052# A value of 0 indicates no limit.
3053#Default:
3054# no limit
3055
3056# TAG: minimum_object_size (bytes)
3057# Objects smaller than this size will NOT be saved on disk. The
3058# value is specified in bytes, and the default is 0 KB, which
3059# means all responses can be stored.
3060#Default:
3061# no limit
3062
3063# TAG: maximum_object_size (bytes)
3064# The default limit on size of objects stored to disk.
3065# This size is used for cache_dir where max-size is not set.
3066# The value is specified in bytes, and the default is 4 MB.
3067#
3068# If you wish to get a high BYTES hit ratio, you should probably
3069# increase this (one 32 MB object hit counts for 3200 10KB
3070# hits).
3071#
3072# If you wish to increase hit ratio more than you want to
3073# save bandwidth you should leave this low.
3074#
3075# NOTE: if using the LFUDA replacement policy you should increase
3076# this value to maximize the byte hit rate improvement of LFUDA!
3077# See replacement_policy below for a discussion of this policy.
3078#Default:
3079# maximum_object_size 4 MB
3080
3081# TAG: cache_swap_low (percent, 0-100)
3082# The low-water mark for cache object replacement.
3083# Replacement begins when the swap (disk) usage is above the
3084# low-water mark and attempts to maintain utilization near the
3085# low-water mark. As swap utilization gets close to high-water
3086# mark object eviction becomes more aggressive. If utilization is
3087# close to the low-water mark less replacement is done each time.
3088#
3089# Defaults are 90% and 95%. If you have a large cache, 5% could be
3090# hundreds of MB. If this is the case you may wish to set these
3091# numbers closer together.
3092#
3093# See also cache_swap_high
3094#Default:
3095# cache_swap_low 90
3096
3097# TAG: cache_swap_high (percent, 0-100)
3098# The high-water mark for cache object replacement.
3099# Replacement begins when the swap (disk) usage is above the
3100# low-water mark and attempts to maintain utilization near the
3101# low-water mark. As swap utilization gets close to high-water
3102# mark object eviction becomes more aggressive. If utilization is
3103# close to the low-water mark less replacement is done each time.
3104#
3105# Defaults are 90% and 95%. If you have a large cache, 5% could be
3106# hundreds of MB. If this is the case you may wish to set these
3107# numbers closer together.
3108#
3109# See also cache_swap_low
3110#Default:
3111# cache_swap_high 95
3112
3113# LOGFILE OPTIONS
3114# -----------------------------------------------------------------------------
3115
3116# TAG: logformat
3117# Usage:
3118#
3119# logformat <name> <format specification>
3120#
3121# Defines an access log format.
3122#
3123# The <format specification> is a string with embedded % format codes
3124#
3125# % format codes all follow the same basic structure where all but
3126# the formatcode is optional. Output strings are automatically escaped
3127# as required according to their context and the output format
3128# modifiers are usually not needed, but can be specified if an explicit
3129# output format is desired.
3130#
3131# % ["|[|'|#] [-] [[0]width] [{argument}] formatcode
3132#
3133# " output in quoted string format
3134# [ output in squid text log format as used by log_mime_hdrs
3135# # output in URL quoted format
3136# ' output as-is
3137#
3138# - left aligned
3139#
3140# width minimum and/or maximum field width:
3141# [width_min][.width_max]
3142# When minimum starts with 0, the field is zero-padded.
3143# String values exceeding maximum width are truncated.
3144#
3145# {arg} argument such as header name etc
3146#
3147# Format codes:
3148#
3149# % a literal % character
3150# sn Unique sequence number per log line entry
3151# err_code The ID of an error response served by Squid or
3152# a similar internal error identifier.
3153# err_detail Additional err_code-dependent error information.
3154#
3155# Connection related format codes:
3156#
3157# >a Client source IP address
3158# >A Client FQDN
3159# >p Client source port
3160# >eui Client source EUI (MAC address, EUI-48 or EUI-64 identifier)
3161# >la Local IP address the client connected to
3162# >lp Local port number the client connected to
3163#
3164# la Local listening IP address the client connection was connected to.
3165# lp Local listening port number the client connection was connected to.
3166#
3167# <a Server IP address of the last server or peer connection
3168# <A Server FQDN or peer name
3169# <p Server port number of the last server or peer connection
3170# <la Local IP address of the last server or peer connection
3171# <lp Local port number of the last server or peer connection
3172#
3173# Time related format codes:
3174#
3175# ts Seconds since epoch
3176# tu subsecond time (milliseconds)
3177# tl Local time. Optional strftime format argument
3178# default %d/%b/%Y:%H:%M:%S %z
3179# tg GMT time. Optional strftime format argument
3180# default %d/%b/%Y:%H:%M:%S %z
3181# tr Response time (milliseconds)
3182# dt Total time spent making DNS lookups (milliseconds)
3183#
3184# Access Control related format codes:
3185#
3186# et Tag returned by external acl
3187# ea Log string returned by external acl
3188# un User name (any available)
3189# ul User name from authentication
3190# ue User name from external acl helper
3191# ui User name from ident
3192# us User name from SSL
3193#
3194# HTTP related format codes:
3195#
3196# [http::]>h Original received request header.
3197# Usually differs from the request header sent by
3198# Squid, although most fields are often preserved.
3199# Accepts optional header field name/value filter
3200# argument using name[:[separator]element] format.
3201# [http::]>ha Received request header after adaptation and
3202# redirection (pre-cache REQMOD vectoring point).
3203# Usually differs from the request header sent by
3204# Squid, although most fields are often preserved.
3205# Optional header name argument as for >h
3206# [http::]<h Reply header. Optional header name argument
3207# as for >h
3208# [http::]>Hs HTTP status code sent to the client
3209# [http::]<Hs HTTP status code received from the next hop
3210# [http::]<bs Number of HTTP-equivalent message body bytes
3211# received from the next hop, excluding chunked
3212# transfer encoding and control messages.
3213# Generated FTP/Gopher listings are treated as
3214# received bodies.
3215# [http::]mt MIME content type
3216# [http::]rm Request method (GET/POST etc)
3217# [http::]>rm Request method from client
3218# [http::]<rm Request method sent to server or peer
3219# [http::]ru Request URL from client (historic, filtered for logging)
3220# [http::]>ru Request URL from client
3221# [http::]<ru Request URL sent to server or peer
3222# [http::]rp Request URL-Path excluding hostname
3223# [http::]>rp Request URL-Path excluding hostname from client
3224# [http::]<rp Request URL-Path excluding hostname sento to server or peer
3225# [http::]rv Request protocol version
3226# [http::]>rv Request protocol version from client
3227# [http::]<rv Request protocol version sent to server or peer
3228# [http::]<st Sent reply size including HTTP headers
3229# [http::]>st Received request size including HTTP headers. In the
3230# case of chunked requests the chunked encoding metadata
3231# are not included
3232# [http::]>sh Received HTTP request headers size
3233# [http::]<sh Sent HTTP reply headers size
3234# [http::]st Request+Reply size including HTTP headers
3235# [http::]<sH Reply high offset sent
3236# [http::]<sS Upstream object size
3237# [http::]<pt Peer response time in milliseconds. The timer starts
3238# when the last request byte is sent to the next hop
3239# and stops when the last response byte is received.
3240# [http::]<tt Total server-side time in milliseconds. The timer
3241# starts with the first connect request (or write I/O)
3242# sent to the first selected peer. The timer stops
3243# with the last I/O with the last peer.
3244#
3245# Squid handling related format codes:
3246#
3247# Ss Squid request status (TCP_MISS etc)
3248# Sh Squid hierarchy status (DEFAULT_PARENT etc)
3249#
3250# SSL-related format codes:
3251#
3252# ssl::bump_mode SslBump decision for the transaction:
3253#
3254# For CONNECT requests that initiated bumping of
3255# a connection and for any request received on
3256# an already bumped connection, Squid logs the
3257# corresponding SslBump mode ("server-first" or
3258# "client-first"). See the ssl_bump option for
3259# more information about these modes.
3260#
3261# A "none" token is logged for requests that
3262# triggered "ssl_bump" ACL evaluation matching
3263# either a "none" rule or no rules at all.
3264#
3265# In all other cases, a single dash ("-") is
3266# logged.
3267#
3268# If ICAP is enabled, the following code becomes available (as
3269# well as ICAP log codes documented with the icap_log option):
3270#
3271# icap::tt Total ICAP processing time for the HTTP
3272# transaction. The timer ticks when ICAP
3273# ACLs are checked and when ICAP
3274# transaction is in progress.
3275#
3276# If adaptation is enabled the following three codes become available:
3277#
3278# adapt::<last_h The header of the last ICAP response or
3279# meta-information from the last eCAP
3280# transaction related to the HTTP transaction.
3281# Like <h, accepts an optional header name
3282# argument.
3283#
3284# adapt::sum_trs Summed adaptation transaction response
3285# times recorded as a comma-separated list in
3286# the order of transaction start time. Each time
3287# value is recorded as an integer number,
3288# representing response time of one or more
3289# adaptation (ICAP or eCAP) transaction in
3290# milliseconds. When a failed transaction is
3291# being retried or repeated, its time is not
3292# logged individually but added to the
3293# replacement (next) transaction. See also:
3294# adapt::all_trs.
3295#
3296# adapt::all_trs All adaptation transaction response times.
3297# Same as adaptation_strs but response times of
3298# individual transactions are never added
3299# together. Instead, all transaction response
3300# times are recorded individually.
3301#
3302# You can prefix adapt::*_trs format codes with adaptation
3303# service name in curly braces to record response time(s) specific
3304# to that service. For example: %{my_service}adapt::sum_trs
3305#
3306# If SSL is enabled, the following formating codes become available:
3307#
3308# %ssl::>cert_subject The Subject field of the received client
3309# SSL certificate or a dash ('-') if Squid has
3310# received an invalid/malformed certificate or
3311# no certificate at all. Consider encoding the
3312# logged value because Subject often has spaces.
3313#
3314# %ssl::>cert_issuer The Issuer field of the received client
3315# SSL certificate or a dash ('-') if Squid has
3316# received an invalid/malformed certificate or
3317# no certificate at all. Consider encoding the
3318# logged value because Issuer often has spaces.
3319#
3320# The default formats available (which do not need re-defining) are:
3321#
3322#logformat squid %ts.%03tu %6tr %>a %Ss/%03>Hs %<st %rm %ru %[un %Sh/%<a %mt
3323#logformat common %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st %Ss:%Sh
3324#logformat combined %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st "%{Referer}>h" "%{User-Agent}>h" %Ss:%Sh
3325#logformat referrer %ts.%03tu %>a %{Referer}>h %ru
3326#logformat useragent %>a [%tl] "%{User-Agent}>h"
3327#
3328# NOTE: When the log_mime_hdrs directive is set to ON.
3329# The squid, common and combined formats have a safely encoded copy
3330# of the mime headers appended to each line within a pair of brackets.
3331#
3332# NOTE: The common and combined formats are not quite true to the Apache definition.
3333# The logs from Squid contain an extra status and hierarchy code appended.
3334#
3335#Default:
3336# The format definitions squid, common, combined, referrer, useragent are built in.
3337
3338# TAG: access_log
3339# These files log client request activities. Has a line every HTTP or
3340# ICP request. The format is:
3341# access_log <module>:<place> [<logformat name> [acl acl ...]]
3342# access_log none [acl acl ...]]
3343#
3344# Will log to the specified module:place using the specified format (which
3345# must be defined in a logformat directive) those entries which match
3346# ALL the acl's specified (which must be defined in acl clauses).
3347# If no acl is specified, all requests will be logged to this destination.
3348#
3349# ===== Modules Currently available =====
3350#
3351# none Do not log any requests matching these ACL.
3352# Do not specify Place or logformat name.
3353#
3354# stdio Write each log line to disk immediately at the completion of
3355# each request.
3356# Place: the filename and path to be written.
3357#
3358# daemon Very similar to stdio. But instead of writing to disk the log
3359# line is passed to a daemon helper for asychronous handling instead.
3360# Place: varies depending on the daemon.
3361#
3362# log_file_daemon Place: the file name and path to be written.
3363#
3364# syslog To log each request via syslog facility.
3365# Place: The syslog facility and priority level for these entries.
3366# Place Format: facility.priority
3367#
3368# where facility could be any of:
3369# authpriv, daemon, local0 ... local7 or user.
3370#
3371# And priority could be any of:
3372# err, warning, notice, info, debug.
3373#
3374# udp To send each log line as text data to a UDP receiver.
3375# Place: The destination host name or IP and port.
3376# Place Format: //host:port
3377#
3378# tcp To send each log line as text data to a TCP receiver.
3379# Place: The destination host name or IP and port.
3380# Place Format: //host:port
3381#
3382# Default:
3383# access_log daemon:/var/log/squid3/access.log squid
3384#Default:
3385# access_log daemon:/var/log/squid3/access.log squid
3386
3387# TAG: icap_log
3388# ICAP log files record ICAP transaction summaries, one line per
3389# transaction.
3390#
3391# The icap_log option format is:
3392# icap_log <filepath> [<logformat name> [acl acl ...]]
3393# icap_log none [acl acl ...]]
3394#
3395# Please see access_log option documentation for details. The two
3396# kinds of logs share the overall configuration approach and many
3397# features.
3398#
3399# ICAP processing of a single HTTP message or transaction may
3400# require multiple ICAP transactions. In such cases, multiple
3401# ICAP transaction log lines will correspond to a single access
3402# log line.
3403#
3404# ICAP log uses logformat codes that make sense for an ICAP
3405# transaction. Header-related codes are applied to the HTTP header
3406# embedded in an ICAP server response, with the following caveats:
3407# For REQMOD, there is no HTTP response header unless the ICAP
3408# server performed request satisfaction. For RESPMOD, the HTTP
3409# request header is the header sent to the ICAP server. For
3410# OPTIONS, there are no HTTP headers.
3411#
3412# The following format codes are also available for ICAP logs:
3413#
3414# icap::<A ICAP server IP address. Similar to <A.
3415#
3416# icap::<service_name ICAP service name from the icap_service
3417# option in Squid configuration file.
3418#
3419# icap::ru ICAP Request-URI. Similar to ru.
3420#
3421# icap::rm ICAP request method (REQMOD, RESPMOD, or
3422# OPTIONS). Similar to existing rm.
3423#
3424# icap::>st Bytes sent to the ICAP server (TCP payload
3425# only; i.e., what Squid writes to the socket).
3426#
3427# icap::<st Bytes received from the ICAP server (TCP
3428# payload only; i.e., what Squid reads from
3429# the socket).
3430#
3431# icap::<bs Number of message body bytes received from the
3432# ICAP server. ICAP message body, if any, usually
3433# includes encapsulated HTTP message headers and
3434# possibly encapsulated HTTP message body. The
3435# HTTP body part is dechunked before its size is
3436# computed.
3437#
3438# icap::tr Transaction response time (in
3439# milliseconds). The timer starts when
3440# the ICAP transaction is created and
3441# stops when the transaction is completed.
3442# Similar to tr.
3443#
3444# icap::tio Transaction I/O time (in milliseconds). The
3445# timer starts when the first ICAP request
3446# byte is scheduled for sending. The timers
3447# stops when the last byte of the ICAP response
3448# is received.
3449#
3450# icap::to Transaction outcome: ICAP_ERR* for all
3451# transaction errors, ICAP_OPT for OPTION
3452# transactions, ICAP_ECHO for 204
3453# responses, ICAP_MOD for message
3454# modification, and ICAP_SAT for request
3455# satisfaction. Similar to Ss.
3456#
3457# icap::Hs ICAP response status code. Similar to Hs.
3458#
3459# icap::>h ICAP request header(s). Similar to >h.
3460#
3461# icap::<h ICAP response header(s). Similar to <h.
3462#
3463# The default ICAP log format, which can be used without an explicit
3464# definition, is called icap_squid:
3465#
3466#logformat icap_squid %ts.%03tu %6icap::tr %>a %icap::to/%03icap::Hs %icap::<size %icap::rm %icap::ru% %un -/%icap::<A -
3467#
3468# See also: logformat, log_icap, and %adapt::<last_h
3469#Default:
3470# none
3471
3472# TAG: logfile_daemon
3473# Specify the path to the logfile-writing daemon. This daemon is
3474# used to write the access and store logs, if configured.
3475#
3476# Squid sends a number of commands to the log daemon:
3477# L<data>\n - logfile data
3478# R\n - rotate file
3479# T\n - truncate file
3480# O\n - reopen file
3481# F\n - flush file
3482# r<n>\n - set rotate count to <n>
3483# b<n>\n - 1 = buffer output, 0 = don't buffer output
3484#
3485# No responses is expected.
3486#Default:
3487# logfile_daemon /usr/lib/squid3/log_file_daemon
3488
3489# TAG: log_access allow|deny acl acl...
3490# This options allows you to control which requests gets logged
3491# to access.log (see access_log directive). Requests denied for
3492# logging will also not be accounted for in performance counters.
3493#
3494# This clause only supports fast acl types.
3495# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
3496#Default:
3497# Allow logging for all transactions.
3498
3499# TAG: log_icap
3500# This options allows you to control which requests get logged
3501# to icap.log. See the icap_log directive for ICAP log details.
3502#Default:
3503# Allow logging for all ICAP transactions.
3504
3505# TAG: cache_store_log
3506# Logs the activities of the storage manager. Shows which
3507# objects are ejected from the cache, and which objects are
3508# saved and for how long.
3509# There are not really utilities to analyze this data, so you can safely
3510# disable it (the default).
3511#
3512# Store log uses modular logging outputs. See access_log for the list
3513# of modules supported.
3514#
3515# Example:
3516# cache_store_log stdio:/var/log/squid3/store.log
3517# cache_store_log daemon:/var/log/squid3/store.log
3518#Default:
3519# none
3520
3521# TAG: cache_swap_state
3522# Location for the cache "swap.state" file. This index file holds
3523# the metadata of objects saved on disk. It is used to rebuild
3524# the cache during startup. Normally this file resides in each
3525# 'cache_dir' directory, but you may specify an alternate
3526# pathname here. Note you must give a full filename, not just
3527# a directory. Since this is the index for the whole object
3528# list you CANNOT periodically rotate it!
3529#
3530# If %s can be used in the file name it will be replaced with a
3531# a representation of the cache_dir name where each / is replaced
3532# with '.'. This is needed to allow adding/removing cache_dir
3533# lines when cache_swap_log is being used.
3534#
3535# If have more than one 'cache_dir', and %s is not used in the name
3536# these swap logs will have names such as:
3537#
3538# cache_swap_log.00
3539# cache_swap_log.01
3540# cache_swap_log.02
3541#
3542# The numbered extension (which is added automatically)
3543# corresponds to the order of the 'cache_dir' lines in this
3544# configuration file. If you change the order of the 'cache_dir'
3545# lines in this file, these index files will NOT correspond to
3546# the correct 'cache_dir' entry (unless you manually rename
3547# them). We recommend you do NOT use this option. It is
3548# better to keep these index files in each 'cache_dir' directory.
3549#Default:
3550# Store the journal inside its cache_dir
3551
3552# TAG: logfile_rotate
3553# Specifies the number of logfile rotations to make when you
3554# type 'squid -k rotate'. The default is 10, which will rotate
3555# with extensions 0 through 9. Setting logfile_rotate to 0 will
3556# disable the file name rotation, but the logfiles are still closed
3557# and re-opened. This will enable you to rename the logfiles
3558# yourself just before sending the rotate signal.
3559#
3560# Note, the 'squid -k rotate' command normally sends a USR1
3561# signal to the running squid process. In certain situations
3562# (e.g. on Linux with Async I/O), USR1 is used for other
3563# purposes, so -k rotate uses another signal. It is best to get
3564# in the habit of using 'squid -k rotate' instead of 'kill -USR1
3565# <pid>'.
3566#
3567# Note, from Squid-3.1 this option is only a default for cache.log,
3568# that log can be rotated separately by using debug_options.
3569#
3570# Note2, for Debian/Linux the default of logfile_rotate is
3571# zero, since it includes external logfile-rotation methods.
3572#Default:
3573# logfile_rotate 0
3574
3575# TAG: emulate_httpd_log
3576# Replace this with an access_log directive using the format 'common' or 'combined'.
3577#Default:
3578# none
3579
3580# TAG: log_ip_on_direct
3581# Remove this option from your config. To log server or peer names use %<A in the log format.
3582#Default:
3583# none
3584
3585# TAG: mime_table
3586# Path to Squid's icon configuration file.
3587#
3588# You shouldn't need to change this, but the default file contains
3589# examples and formatting information if you do.
3590#Default:
3591# mime_table /usr/share/squid3/mime.conf
3592
3593# TAG: log_mime_hdrs on|off
3594# The Cache can record both the request and the response MIME
3595# headers for each HTTP transaction. The headers are encoded
3596# safely and will appear as two bracketed fields at the end of
3597# the access log (for either the native or httpd-emulated log
3598# formats). To enable this logging set log_mime_hdrs to 'on'.
3599#Default:
3600# log_mime_hdrs off
3601
3602# TAG: useragent_log
3603# Replace this with an access_log directive using the format 'useragent'.
3604#Default:
3605# none
3606
3607# TAG: referer_log
3608# Replace this with an access_log directive using the format 'referrer'.
3609#Default:
3610# none
3611
3612# TAG: pid_filename
3613# A filename to write the process-id to. To disable, enter "none".
3614#Default:
3615# pid_filename /var/run/squid3.pid
3616
3617# TAG: log_fqdn
3618# Remove this option from your config. To log FQDN use %>A in the log format.
3619#Default:
3620# none
3621
3622# TAG: client_netmask
3623# A netmask for client addresses in logfiles and cachemgr output.
3624# Change this to protect the privacy of your cache clients.
3625# A netmask of 255.255.255.0 will log all IP's in that range with
3626# the last digit set to '0'.
3627#Default:
3628# Log full client IP address
3629
3630# TAG: forward_log
3631# Use a regular access.log with ACL limiting it to MISS events.
3632#Default:
3633# none
3634
3635# TAG: strip_query_terms
3636# By default, Squid strips query terms from requested URLs before
3637# logging. This protects your user's privacy and reduces log size.
3638#
3639# When investigating HIT/MISS or other caching behaviour you
3640# will need to disable this to see the full URL used by Squid.
3641#Default:
3642# strip_query_terms on
3643
3644# TAG: buffered_logs on|off
3645# Whether to write/send access_log records ASAP or accumulate them and
3646# then write/send them in larger chunks. Buffering may improve
3647# performance because it decreases the number of I/Os. However,
3648# buffering increases the delay before log records become available to
3649# the final recipient (e.g., a disk file or logging daemon) and,
3650# hence, increases the risk of log records loss.
3651#
3652# Note that even when buffered_logs are off, Squid may have to buffer
3653# records if it cannot write/send them immediately due to pending I/Os
3654# (e.g., the I/O writing the previous log record) or connectivity loss.
3655#
3656# Currently honored by 'daemon' access_log module only.
3657#Default:
3658# buffered_logs off
3659
3660# TAG: netdb_filename
3661# Where Squid stores it's netdb journal.
3662# When enabled this journal preserves netdb state between restarts.
3663#
3664# To disable, enter "none".
3665#Default:
3666# netdb_filename stdio:/var/log/squid3/netdb.state
3667
3668# OPTIONS FOR TROUBLESHOOTING
3669# -----------------------------------------------------------------------------
3670
3671# TAG: cache_log
3672# Squid administrative logging file.
3673#
3674# This is where general information about Squid behavior goes. You can
3675# increase the amount of data logged to this file and how often it is
3676# rotated with "debug_options"
3677#Default:
3678# cache_log /var/log/squid3/cache.log
3679
3680# TAG: debug_options
3681# Logging options are set as section,level where each source file
3682# is assigned a unique section. Lower levels result in less
3683# output, Full debugging (level 9) can result in a very large
3684# log file, so be careful.
3685#
3686# The magic word "ALL" sets debugging levels for all sections.
3687# The default is to run with "ALL,1" to record important warnings.
3688#
3689# The rotate=N option can be used to keep more or less of these logs
3690# than would otherwise be kept by logfile_rotate.
3691# For most uses a single log should be enough to monitor current
3692# events affecting Squid.
3693#Default:
3694# Log all critical and important messages.
3695
3696# TAG: coredump_dir
3697# By default Squid leaves core files in the directory from where
3698# it was started. If you set 'coredump_dir' to a directory
3699# that exists, Squid will chdir() to that directory at startup
3700# and coredump files will be left there.
3701#
3702#Default:
3703# Use the directory from where Squid was started.
3704#
3705
3706# Leave coredumps in the first cache dir
3707coredump_dir /var/spool/squid3
3708
3709# OPTIONS FOR FTP GATEWAYING
3710# -----------------------------------------------------------------------------
3711
3712# TAG: ftp_user
3713# If you want the anonymous login password to be more informative
3714# (and enable the use of picky FTP servers), set this to something
3715# reasonable for your domain, like wwwuser@somewhere.net
3716#
3717# The reason why this is domainless by default is the
3718# request can be made on the behalf of a user in any domain,
3719# depending on how the cache is used.
3720# Some FTP server also validate the email address is valid
3721# (for example perl.com).
3722#Default:
3723# ftp_user Squid@
3724
3725# TAG: ftp_passive
3726# If your firewall does not allow Squid to use passive
3727# connections, turn off this option.
3728#
3729# Use of ftp_epsv_all option requires this to be ON.
3730#Default:
3731# ftp_passive on
3732
3733# TAG: ftp_epsv_all
3734# FTP Protocol extensions permit the use of a special "EPSV ALL" command.
3735#
3736# NATs may be able to put the connection on a "fast path" through the
3737# translator, as the EPRT command will never be used and therefore,
3738# translation of the data portion of the segments will never be needed.
3739#
3740# When a client only expects to do two-way FTP transfers this may be
3741# useful.
3742# If squid finds that it must do a three-way FTP transfer after issuing
3743# an EPSV ALL command, the FTP session will fail.
3744#
3745# If you have any doubts about this option do not use it.
3746# Squid will nicely attempt all other connection methods.
3747#
3748# Requires ftp_passive to be ON (default) for any effect.
3749#Default:
3750# ftp_epsv_all off
3751
3752# TAG: ftp_epsv
3753# FTP Protocol extensions permit the use of a special "EPSV" command.
3754#
3755# NATs may be able to put the connection on a "fast path" through the
3756# translator using EPSV, as the EPRT command will never be used
3757# and therefore, translation of the data portion of the segments
3758# will never be needed.
3759#
3760# Turning this OFF will prevent EPSV being attempted.
3761# WARNING: Doing so will convert Squid back to the old behavior with all
3762# the related problems with external NAT devices/layers.
3763#
3764# Requires ftp_passive to be ON (default) for any effect.
3765#Default:
3766# ftp_epsv on
3767
3768# TAG: ftp_eprt
3769# FTP Protocol extensions permit the use of a special "EPRT" command.
3770#
3771# This extension provides a protocol neutral alternative to the
3772# IPv4-only PORT command. When supported it enables active FTP data
3773# channels over IPv6 and efficient NAT handling.
3774#
3775# Turning this OFF will prevent EPRT being attempted and will skip
3776# straight to using PORT for IPv4 servers.
3777#
3778# Some devices are known to not handle this extension correctly and
3779# may result in crashes. Devices which suport EPRT enough to fail
3780# cleanly will result in Squid attempting PORT anyway. This directive
3781# should only be disabled when EPRT results in device failures.
3782#
3783# WARNING: Doing so will convert Squid back to the old behavior with all
3784# the related problems with external NAT devices/layers and IPv4-only FTP.
3785#Default:
3786# ftp_eprt on
3787
3788# TAG: ftp_sanitycheck
3789# For security and data integrity reasons Squid by default performs
3790# sanity checks of the addresses of FTP data connections ensure the
3791# data connection is to the requested server. If you need to allow
3792# FTP connections to servers using another IP address for the data
3793# connection turn this off.
3794#Default:
3795# ftp_sanitycheck on
3796
3797# TAG: ftp_telnet_protocol
3798# The FTP protocol is officially defined to use the telnet protocol
3799# as transport channel for the control connection. However, many
3800# implementations are broken and does not respect this aspect of
3801# the FTP protocol.
3802#
3803# If you have trouble accessing files with ASCII code 255 in the
3804# path or similar problems involving this ASCII code you can
3805# try setting this directive to off. If that helps, report to the
3806# operator of the FTP server in question that their FTP server
3807# is broken and does not follow the FTP standard.
3808#Default:
3809# ftp_telnet_protocol on
3810
3811# OPTIONS FOR EXTERNAL SUPPORT PROGRAMS
3812# -----------------------------------------------------------------------------
3813
3814# TAG: diskd_program
3815# Specify the location of the diskd executable.
3816# Note this is only useful if you have compiled in
3817# diskd as one of the store io modules.
3818#Default:
3819# diskd_program /usr/lib/squid3/diskd
3820
3821# TAG: unlinkd_program
3822# Specify the location of the executable for file deletion process.
3823#Default:
3824# unlinkd_program /usr/lib/squid3/unlinkd
3825
3826# TAG: pinger_program
3827# Specify the location of the executable for the pinger process.
3828#Default:
3829# pinger_program /usr/lib/squid3/pinger
3830
3831# TAG: pinger_enable
3832# Control whether the pinger is active at run-time.
3833# Enables turning ICMP pinger on and off with a simple
3834# squid -k reconfigure.
3835#Default:
3836# pinger_enable on
3837
3838# OPTIONS FOR URL REWRITING
3839# -----------------------------------------------------------------------------
3840
3841# TAG: url_rewrite_program
3842# Specify the location of the executable URL rewriter to use.
3843# Since they can perform almost any function there isn't one included.
3844#
3845# For each requested URL, the rewriter will receive on line with the format
3846#
3847# URL <SP> client_ip "/" fqdn <SP> user <SP> method [<SP> kvpairs]<NL>
3848#
3849# In the future, the rewriter interface will be extended with
3850# key=value pairs ("kvpairs" shown above). Rewriter programs
3851# should be prepared to receive and possibly ignore additional
3852# whitespace-separated tokens on each input line.
3853#
3854# And the rewriter may return a rewritten URL. The other components of
3855# the request line does not need to be returned (ignored if they are).
3856#
3857# The rewriter can also indicate that a client-side redirect should
3858# be performed to the new URL. This is done by prefixing the returned
3859# URL with "301:" (moved permanently) or 302: (moved temporarily), etc.
3860#
3861# By default, a URL rewriter is not used.
3862#Default:
3863# none
3864
3865# TAG: url_rewrite_children
3866# The maximum number of redirector processes to spawn. If you limit
3867# it too few Squid will have to wait for them to process a backlog of
3868# URLs, slowing it down. If you allow too many they will use RAM
3869# and other system resources noticably.
3870#
3871# The startup= and idle= options allow some measure of skew in your
3872# tuning.
3873#
3874# startup=
3875#
3876# Sets a minimum of how many processes are to be spawned when Squid
3877# starts or reconfigures. When set to zero the first request will
3878# cause spawning of the first child process to handle it.
3879#
3880# Starting too few will cause an initial slowdown in traffic as Squid
3881# attempts to simultaneously spawn enough processes to cope.
3882#
3883# idle=
3884#
3885# Sets a minimum of how many processes Squid is to try and keep available
3886# at all times. When traffic begins to rise above what the existing
3887# processes can handle this many more will be spawned up to the maximum
3888# configured. A minimum setting of 1 is required.
3889#
3890# concurrency=
3891#
3892# The number of requests each redirector helper can handle in
3893# parallel. Defaults to 0 which indicates the redirector
3894# is a old-style single threaded redirector.
3895#
3896# When this directive is set to a value >= 1 then the protocol
3897# used to communicate with the helper is modified to include
3898# a request ID in front of the request/response. The request
3899# ID from the request must be echoed back with the response
3900# to that request.
3901#Default:
3902# url_rewrite_children 20 startup=0 idle=1 concurrency=0
3903
3904# TAG: url_rewrite_host_header
3905# To preserve same-origin security policies in browsers and
3906# prevent Host: header forgery by redirectors Squid rewrites
3907# any Host: header in redirected requests.
3908#
3909# If you are running an accelerator this may not be a wanted
3910# effect of a redirector. This directive enables you disable
3911# Host: alteration in reverse-proxy traffic.
3912#
3913# WARNING: Entries are cached on the result of the URL rewriting
3914# process, so be careful if you have domain-virtual hosts.
3915#
3916# WARNING: Squid and other software verifies the URL and Host
3917# are matching, so be careful not to relay through other proxies
3918# or inspecting firewalls with this disabled.
3919#Default:
3920# url_rewrite_host_header on
3921
3922# TAG: url_rewrite_access
3923# If defined, this access list specifies which requests are
3924# sent to the redirector processes.
3925#
3926# This clause supports both fast and slow acl types.
3927# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
3928#Default:
3929# Allow, unless rules exist in squid.conf.
3930
3931# TAG: url_rewrite_bypass
3932# When this is 'on', a request will not go through the
3933# redirector if all the helpers are busy. If this is 'off'
3934# and the redirector queue grows too large, Squid will exit
3935# with a FATAL error and ask you to increase the number of
3936# redirectors. You should only enable this if the redirectors
3937# are not critical to your caching system. If you use
3938# redirectors for access control, and you enable this option,
3939# users may have access to pages they should not
3940# be allowed to request.
3941#Default:
3942# url_rewrite_bypass off
3943
3944# OPTIONS FOR TUNING THE CACHE
3945# -----------------------------------------------------------------------------
3946
3947# TAG: cache
3948# A list of ACL elements which, if matched and denied, cause the request to
3949# not be satisfied from the cache and the reply to not be cached.
3950# In other words, use this to force certain objects to never be cached.
3951#
3952# You must use the words 'allow' or 'deny' to indicate whether items
3953# matching the ACL should be allowed or denied into the cache.
3954#
3955# This clause supports both fast and slow acl types.
3956# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
3957#Default:
3958# Allow caching, unless rules exist in squid.conf.
3959
3960# TAG: max_stale time-units
3961# This option puts an upper limit on how stale content Squid
3962# will serve from the cache if cache validation fails.
3963# Can be overriden by the refresh_pattern max-stale option.
3964#Default:
3965# max_stale 1 week
3966
3967# TAG: refresh_pattern
3968# usage: refresh_pattern [-i] regex min percent max [options]
3969#
3970# By default, regular expressions are CASE-SENSITIVE. To make
3971# them case-insensitive, use the -i option.
3972#
3973# 'Min' is the time (in minutes) an object without an explicit
3974# expiry time should be considered fresh. The recommended
3975# value is 0, any higher values may cause dynamic applications
3976# to be erroneously cached unless the application designer
3977# has taken the appropriate actions.
3978#
3979# 'Percent' is a percentage of the objects age (time since last
3980# modification age) an object without explicit expiry time
3981# will be considered fresh.
3982#
3983# 'Max' is an upper limit on how long objects without an explicit
3984# expiry time will be considered fresh.
3985#
3986# options: override-expire
3987# override-lastmod
3988# reload-into-ims
3989# ignore-reload
3990# ignore-no-store
3991# ignore-must-revalidate
3992# ignore-private
3993# ignore-auth
3994# max-stale=NN
3995# refresh-ims
3996# store-stale
3997#
3998# override-expire enforces min age even if the server
3999# sent an explicit expiry time (e.g., with the
4000# Expires: header or Cache-Control: max-age). Doing this
4001# VIOLATES the HTTP standard. Enabling this feature
4002# could make you liable for problems which it causes.
4003#
4004# Note: override-expire does not enforce staleness - it only extends
4005# freshness / min. If the server returns a Expires time which
4006# is longer than your max time, Squid will still consider
4007# the object fresh for that period of time.
4008#
4009# override-lastmod enforces min age even on objects
4010# that were modified recently.
4011#
4012# reload-into-ims changes client no-cache or ``reload''
4013# to If-Modified-Since requests. Doing this VIOLATES the
4014# HTTP standard. Enabling this feature could make you
4015# liable for problems which it causes.
4016#
4017# ignore-reload ignores a client no-cache or ``reload''
4018# header. Doing this VIOLATES the HTTP standard. Enabling
4019# this feature could make you liable for problems which
4020# it causes.
4021#
4022# ignore-no-store ignores any ``Cache-control: no-store''
4023# headers received from a server. Doing this VIOLATES
4024# the HTTP standard. Enabling this feature could make you
4025# liable for problems which it causes.
4026#
4027# ignore-must-revalidate ignores any ``Cache-Control: must-revalidate``
4028# headers received from a server. Doing this VIOLATES
4029# the HTTP standard. Enabling this feature could make you
4030# liable for problems which it causes.
4031#
4032# ignore-private ignores any ``Cache-control: private''
4033# headers received from a server. Doing this VIOLATES
4034# the HTTP standard. Enabling this feature could make you
4035# liable for problems which it causes.
4036#
4037# ignore-auth caches responses to requests with authorization,
4038# as if the originserver had sent ``Cache-control: public''
4039# in the response header. Doing this VIOLATES the HTTP standard.
4040# Enabling this feature could make you liable for problems which
4041# it causes.
4042#
4043# refresh-ims causes squid to contact the origin server
4044# when a client issues an If-Modified-Since request. This
4045# ensures that the client will receive an updated version
4046# if one is available.
4047#
4048# store-stale stores responses even if they don't have explicit
4049# freshness or a validator (i.e., Last-Modified or an ETag)
4050# present, or if they're already stale. By default, Squid will
4051# not cache such responses because they usually can't be
4052# reused. Note that such responses will be stale by default.
4053#
4054# max-stale=NN provide a maximum staleness factor. Squid won't
4055# serve objects more stale than this even if it failed to
4056# validate the object. Default: use the max_stale global limit.
4057#
4058# Basically a cached object is:
4059#
4060# FRESH if expires < now, else STALE
4061# STALE if age > max
4062# FRESH if lm-factor < percent, else STALE
4063# FRESH if age < min
4064# else STALE
4065#
4066# The refresh_pattern lines are checked in the order listed here.
4067# The first entry which matches is used. If none of the entries
4068# match the default will be used.
4069#
4070# Note, you must uncomment all the default lines if you want
4071# to change one. The default setting is only active if none is
4072# used.
4073#
4074#
4075
4076#
4077# Add any of your own refresh_pattern entries above these.
4078#
4079refresh_pattern ^ftp: 1440 20% 10080
4080refresh_pattern ^gopher: 1440 0% 1440
4081refresh_pattern -i (/cgi-bin/|\?) 0 0% 0
4082refresh_pattern (Release|Packages(.gz)*)$ 0 20% 2880
4083# example lin deb packages
4084#refresh_pattern (\.deb|\.udeb)$ 129600 100% 129600
4085refresh_pattern . 0 20% 4320
4086
4087# TAG: quick_abort_min (KB)
4088#Default:
4089# quick_abort_min 16 KB
4090
4091# TAG: quick_abort_max (KB)
4092#Default:
4093# quick_abort_max 16 KB
4094
4095# TAG: quick_abort_pct (percent)
4096# The cache by default continues downloading aborted requests
4097# which are almost completed (less than 16 KB remaining). This
4098# may be undesirable on slow (e.g. SLIP) links and/or very busy
4099# caches. Impatient users may tie up file descriptors and
4100# bandwidth by repeatedly requesting and immediately aborting
4101# downloads.
4102#
4103# When the user aborts a request, Squid will check the
4104# quick_abort values to the amount of data transfered until
4105# then.
4106#
4107# If the transfer has less than 'quick_abort_min' KB remaining,
4108# it will finish the retrieval.
4109#
4110# If the transfer has more than 'quick_abort_max' KB remaining,
4111# it will abort the retrieval.
4112#
4113# If more than 'quick_abort_pct' of the transfer has completed,
4114# it will finish the retrieval.
4115#
4116# If you do not want any retrieval to continue after the client
4117# has aborted, set both 'quick_abort_min' and 'quick_abort_max'
4118# to '0 KB'.
4119#
4120# If you want retrievals to always continue if they are being
4121# cached set 'quick_abort_min' to '-1 KB'.
4122#Default:
4123# quick_abort_pct 95
4124
4125# TAG: read_ahead_gap buffer-size
4126# The amount of data the cache will buffer ahead of what has been
4127# sent to the client when retrieving an object from another server.
4128#Default:
4129# read_ahead_gap 16 KB
4130
4131# TAG: negative_ttl time-units
4132# Set the Default Time-to-Live (TTL) for failed requests.
4133# Certain types of failures (such as "connection refused" and
4134# "404 Not Found") are able to be negatively-cached for a short time.
4135# Modern web servers should provide Expires: header, however if they
4136# do not this can provide a minimum TTL.
4137# The default is not to cache errors with unknown expiry details.
4138#
4139# Note that this is different from negative caching of DNS lookups.
4140#
4141# WARNING: Doing this VIOLATES the HTTP standard. Enabling
4142# this feature could make you liable for problems which it
4143# causes.
4144#Default:
4145# negative_ttl 0 seconds
4146
4147# TAG: positive_dns_ttl time-units
4148# Upper limit on how long Squid will cache positive DNS responses.
4149# Default is 6 hours (360 minutes). This directive must be set
4150# larger than negative_dns_ttl.
4151#Default:
4152# positive_dns_ttl 6 hours
4153
4154# TAG: negative_dns_ttl time-units
4155# Time-to-Live (TTL) for negative caching of failed DNS lookups.
4156# This also sets the lower cache limit on positive lookups.
4157# Minimum value is 1 second, and it is not recommendable to go
4158# much below 10 seconds.
4159#Default:
4160# negative_dns_ttl 1 minutes
4161
4162# TAG: range_offset_limit size [acl acl...]
4163# usage: (size) [units] [[!]aclname]
4164#
4165# Sets an upper limit on how far (number of bytes) into the file
4166# a Range request may be to cause Squid to prefetch the whole file.
4167# If beyond this limit, Squid forwards the Range request as it is and
4168# the result is NOT cached.
4169#
4170# This is to stop a far ahead range request (lets say start at 17MB)
4171# from making Squid fetch the whole object up to that point before
4172# sending anything to the client.
4173#
4174# Multiple range_offset_limit lines may be specified, and they will
4175# be searched from top to bottom on each request until a match is found.
4176# The first match found will be used. If no line matches a request, the
4177# default limit of 0 bytes will be used.
4178#
4179# 'size' is the limit specified as a number of units.
4180#
4181# 'units' specifies whether to use bytes, KB, MB, etc.
4182# If no units are specified bytes are assumed.
4183#
4184# A size of 0 causes Squid to never fetch more than the
4185# client requested. (default)
4186#
4187# A size of 'none' causes Squid to always fetch the object from the
4188# beginning so it may cache the result. (2.0 style)
4189#
4190# 'aclname' is the name of a defined ACL.
4191#
4192# NP: Using 'none' as the byte value here will override any quick_abort settings
4193# that may otherwise apply to the range request. The range request will
4194# be fully fetched from start to finish regardless of the client
4195# actions. This affects bandwidth usage.
4196#Default:
4197# none
4198
4199# TAG: minimum_expiry_time (seconds)
4200# The minimum caching time according to (Expires - Date)
4201# headers Squid honors if the object can't be revalidated.
4202# The default is 60 seconds.
4203#
4204# In reverse proxy environments it might be desirable to honor
4205# shorter object lifetimes. It is most likely better to make
4206# your server return a meaningful Last-Modified header however.
4207#
4208# In ESI environments where page fragments often have short
4209# lifetimes, this will often be best set to 0.
4210#Default:
4211# minimum_expiry_time 60 seconds
4212
4213# TAG: store_avg_object_size (bytes)
4214# Average object size, used to estimate number of objects your
4215# cache can hold. The default is 13 KB.
4216#
4217# This is used to pre-seed the cache index memory allocation to
4218# reduce expensive reallocate operations while handling clients
4219# traffic. Too-large values may result in memory allocation during
4220# peak traffic, too-small values will result in wasted memory.
4221#
4222# Check the cache manager 'info' report metrics for the real
4223# object sizes seen by your Squid before tuning this.
4224#Default:
4225# store_avg_object_size 13 KB
4226
4227# TAG: store_objects_per_bucket
4228# Target number of objects per bucket in the store hash table.
4229# Lowering this value increases the total number of buckets and
4230# also the storage maintenance rate. The default is 20.
4231#Default:
4232# store_objects_per_bucket 20
4233
4234# HTTP OPTIONS
4235# -----------------------------------------------------------------------------
4236
4237# TAG: request_header_max_size (KB)
4238# This specifies the maximum size for HTTP headers in a request.
4239# Request headers are usually relatively small (about 512 bytes).
4240# Placing a limit on the request header size will catch certain
4241# bugs (for example with persistent connections) and possibly
4242# buffer-overflow or denial-of-service attacks.
4243#Default:
4244# request_header_max_size 64 KB
4245
4246# TAG: reply_header_max_size (KB)
4247# This specifies the maximum size for HTTP headers in a reply.
4248# Reply headers are usually relatively small (about 512 bytes).
4249# Placing a limit on the reply header size will catch certain
4250# bugs (for example with persistent connections) and possibly
4251# buffer-overflow or denial-of-service attacks.
4252#Default:
4253# reply_header_max_size 64 KB
4254
4255# TAG: request_body_max_size (bytes)
4256# This specifies the maximum size for an HTTP request body.
4257# In other words, the maximum size of a PUT/POST request.
4258# A user who attempts to send a request with a body larger
4259# than this limit receives an "Invalid Request" error message.
4260# If you set this parameter to a zero (the default), there will
4261# be no limit imposed.
4262#
4263# See also client_request_buffer_max_size for an alternative
4264# limitation on client uploads which can be configured.
4265#Default:
4266# No limit.
4267
4268# TAG: client_request_buffer_max_size (bytes)
4269# This specifies the maximum buffer size of a client request.
4270# It prevents squid eating too much memory when somebody uploads
4271# a large file.
4272#Default:
4273# client_request_buffer_max_size 512 KB
4274
4275# TAG: chunked_request_body_max_size (bytes)
4276# A broken or confused HTTP/1.1 client may send a chunked HTTP
4277# request to Squid. Squid does not have full support for that
4278# feature yet. To cope with such requests, Squid buffers the
4279# entire request and then dechunks request body to create a
4280# plain HTTP/1.0 request with a known content length. The plain
4281# request is then used by the rest of Squid code as usual.
4282#
4283# The option value specifies the maximum size of the buffer used
4284# to hold the request before the conversion. If the chunked
4285# request size exceeds the specified limit, the conversion
4286# fails, and the client receives an "unsupported request" error,
4287# as if dechunking was disabled.
4288#
4289# Dechunking is enabled by default. To disable conversion of
4290# chunked requests, set the maximum to zero.
4291#
4292# Request dechunking feature and this option in particular are a
4293# temporary hack. When chunking requests and responses are fully
4294# supported, there will be no need to buffer a chunked request.
4295#Default:
4296# chunked_request_body_max_size 64 KB
4297
4298# TAG: broken_posts
4299# A list of ACL elements which, if matched, causes Squid to send
4300# an extra CRLF pair after the body of a PUT/POST request.
4301#
4302# Some HTTP servers has broken implementations of PUT/POST,
4303# and rely on an extra CRLF pair sent by some WWW clients.
4304#
4305# Quote from RFC2616 section 4.1 on this matter:
4306#
4307# Note: certain buggy HTTP/1.0 client implementations generate an
4308# extra CRLF's after a POST request. To restate what is explicitly
4309# forbidden by the BNF, an HTTP/1.1 client must not preface or follow
4310# a request with an extra CRLF.
4311#
4312# This clause only supports fast acl types.
4313# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4314#
4315#Example:
4316# acl buggy_server url_regex ^http://....
4317# broken_posts allow buggy_server
4318#Default:
4319# Obey RFC 2616.
4320
4321# TAG: adaptation_uses_indirect_client on|off
4322# Controls whether the indirect client IP address (instead of the direct
4323# client IP address) is passed to adaptation services.
4324#
4325# See also: follow_x_forwarded_for adaptation_send_client_ip
4326#Default:
4327# adaptation_uses_indirect_client on
4328
4329# TAG: via on|off
4330# If set (default), Squid will include a Via header in requests and
4331# replies as required by RFC2616.
4332#Default:
4333# via on
4334
4335# TAG: ie_refresh on|off
4336# Microsoft Internet Explorer up until version 5.5 Service
4337# Pack 1 has an issue with transparent proxies, wherein it
4338# is impossible to force a refresh. Turning this on provides
4339# a partial fix to the problem, by causing all IMS-REFRESH
4340# requests from older IE versions to check the origin server
4341# for fresh content. This reduces hit ratio by some amount
4342# (~10% in my experience), but allows users to actually get
4343# fresh content when they want it. Note because Squid
4344# cannot tell if the user is using 5.5 or 5.5SP1, the behavior
4345# of 5.5 is unchanged from old versions of Squid (i.e. a
4346# forced refresh is impossible). Newer versions of IE will,
4347# hopefully, continue to have the new behavior and will be
4348# handled based on that assumption. This option defaults to
4349# the old Squid behavior, which is better for hit ratios but
4350# worse for clients using IE, if they need to be able to
4351# force fresh content.
4352#Default:
4353# ie_refresh off
4354
4355# TAG: vary_ignore_expire on|off
4356# Many HTTP servers supporting Vary gives such objects
4357# immediate expiry time with no cache-control header
4358# when requested by a HTTP/1.0 client. This option
4359# enables Squid to ignore such expiry times until
4360# HTTP/1.1 is fully implemented.
4361#
4362# WARNING: If turned on this may eventually cause some
4363# varying objects not intended for caching to get cached.
4364#Default:
4365# vary_ignore_expire off
4366
4367# TAG: request_entities
4368# Squid defaults to deny GET and HEAD requests with request entities,
4369# as the meaning of such requests are undefined in the HTTP standard
4370# even if not explicitly forbidden.
4371#
4372# Set this directive to on if you have clients which insists
4373# on sending request entities in GET or HEAD requests. But be warned
4374# that there is server software (both proxies and web servers) which
4375# can fail to properly process this kind of request which may make you
4376# vulnerable to cache pollution attacks if enabled.
4377#Default:
4378# request_entities off
4379
4380# TAG: request_header_access
4381# Usage: request_header_access header_name allow|deny [!]aclname ...
4382#
4383# WARNING: Doing this VIOLATES the HTTP standard. Enabling
4384# this feature could make you liable for problems which it
4385# causes.
4386#
4387# This option replaces the old 'anonymize_headers' and the
4388# older 'http_anonymizer' option with something that is much
4389# more configurable. A list of ACLs for each header name allows
4390# removal of specific header fields under specific conditions.
4391#
4392# This option only applies to outgoing HTTP request headers (i.e.,
4393# headers sent by Squid to the next HTTP hop such as a cache peer
4394# or an origin server). The option has no effect during cache hit
4395# detection. The equivalent adaptation vectoring point in ICAP
4396# terminology is post-cache REQMOD.
4397#
4398# The option is applied to individual outgoing request header
4399# fields. For each request header field F, Squid uses the first
4400# qualifying sets of request_header_access rules:
4401#
4402# 1. Rules with header_name equal to F's name.
4403# 2. Rules with header_name 'Other', provided F's name is not
4404# on the hard-coded list of commonly used HTTP header names.
4405# 3. Rules with header_name 'All'.
4406#
4407# Within that qualifying rule set, rule ACLs are checked as usual.
4408# If ACLs of an "allow" rule match, the header field is allowed to
4409# go through as is. If ACLs of a "deny" rule match, the header is
4410# removed and request_header_replace is then checked to identify
4411# if the removed header has a replacement. If no rules within the
4412# set have matching ACLs, the header field is left as is.
4413#
4414# For example, to achieve the same behavior as the old
4415# 'http_anonymizer standard' option, you should use:
4416#
4417# request_header_access From deny all
4418# request_header_access Referer deny all
4419# request_header_access User-Agent deny all
4420#
4421# Or, to reproduce the old 'http_anonymizer paranoid' feature
4422# you should use:
4423#
4424# request_header_access Authorization allow all
4425# request_header_access Proxy-Authorization allow all
4426# request_header_access Cache-Control allow all
4427# request_header_access Content-Length allow all
4428# request_header_access Content-Type allow all
4429# request_header_access Date allow all
4430# request_header_access Host allow all
4431# request_header_access If-Modified-Since allow all
4432# request_header_access Pragma allow all
4433# request_header_access Accept allow all
4434# request_header_access Accept-Charset allow all
4435# request_header_access Accept-Encoding allow all
4436# request_header_access Accept-Language allow all
4437# request_header_access Connection allow all
4438# request_header_access All deny all
4439#
4440# HTTP reply headers are controlled with the reply_header_access directive.
4441#
4442# By default, all headers are allowed (no anonymizing is performed).
4443#Default:
4444# No limits.
4445
4446# TAG: reply_header_access
4447# Usage: reply_header_access header_name allow|deny [!]aclname ...
4448#
4449# WARNING: Doing this VIOLATES the HTTP standard. Enabling
4450# this feature could make you liable for problems which it
4451# causes.
4452#
4453# This option only applies to reply headers, i.e., from the
4454# server to the client.
4455#
4456# This is the same as request_header_access, but in the other
4457# direction. Please see request_header_access for detailed
4458# documentation.
4459#
4460# For example, to achieve the same behavior as the old
4461# 'http_anonymizer standard' option, you should use:
4462#
4463# reply_header_access Server deny all
4464# reply_header_access WWW-Authenticate deny all
4465# reply_header_access Link deny all
4466#
4467# Or, to reproduce the old 'http_anonymizer paranoid' feature
4468# you should use:
4469#
4470# reply_header_access Allow allow all
4471# reply_header_access WWW-Authenticate allow all
4472# reply_header_access Proxy-Authenticate allow all
4473# reply_header_access Cache-Control allow all
4474# reply_header_access Content-Encoding allow all
4475# reply_header_access Content-Length allow all
4476# reply_header_access Content-Type allow all
4477# reply_header_access Date allow all
4478# reply_header_access Expires allow all
4479# reply_header_access Last-Modified allow all
4480# reply_header_access Location allow all
4481# reply_header_access Pragma allow all
4482# reply_header_access Content-Language allow all
4483# reply_header_access Retry-After allow all
4484# reply_header_access Title allow all
4485# reply_header_access Content-Disposition allow all
4486# reply_header_access Connection allow all
4487# reply_header_access All deny all
4488#
4489# HTTP request headers are controlled with the request_header_access directive.
4490#
4491# By default, all headers are allowed (no anonymizing is
4492# performed).
4493#Default:
4494# No limits.
4495
4496# TAG: request_header_replace
4497# Usage: request_header_replace header_name message
4498# Example: request_header_replace User-Agent Nutscrape/1.0 (CP/M; 8-bit)
4499#
4500# This option allows you to change the contents of headers
4501# denied with request_header_access above, by replacing them
4502# with some fixed string.
4503#
4504# This only applies to request headers, not reply headers.
4505#
4506# By default, headers are removed if denied.
4507#Default:
4508# none
4509
4510# TAG: reply_header_replace
4511# Usage: reply_header_replace header_name message
4512# Example: reply_header_replace Server Foo/1.0
4513#
4514# This option allows you to change the contents of headers
4515# denied with reply_header_access above, by replacing them
4516# with some fixed string.
4517#
4518# This only applies to reply headers, not request headers.
4519#
4520# By default, headers are removed if denied.
4521#Default:
4522# none
4523
4524# TAG: request_header_add
4525# Usage: request_header_add field-name field-value acl1 [acl2] ...
4526# Example: request_header_add X-Client-CA "CA=%ssl::>cert_issuer" all
4527#
4528# This option adds header fields to outgoing HTTP requests (i.e.,
4529# request headers sent by Squid to the next HTTP hop such as a
4530# cache peer or an origin server). The option has no effect during
4531# cache hit detection. The equivalent adaptation vectoring point
4532# in ICAP terminology is post-cache REQMOD.
4533#
4534# Field-name is a token specifying an HTTP header name. If a
4535# standard HTTP header name is used, Squid does not check whether
4536# the new header conflicts with any existing headers or violates
4537# HTTP rules. If the request to be modified already contains a
4538# field with the same name, the old field is preserved but the
4539# header field values are not merged.
4540#
4541# Field-value is either a token or a quoted string. If quoted
4542# string format is used, then the surrounding quotes are removed
4543# while escape sequences and %macros are processed.
4544#
4545# In theory, all of the logformat codes can be used as %macros.
4546# However, unlike logging (which happens at the very end of
4547# transaction lifetime), the transaction may not yet have enough
4548# information to expand a macro when the new header value is needed.
4549# And some information may already be available to Squid but not yet
4550# committed where the macro expansion code can access it (report
4551# such instances!). The macro will be expanded into a single dash
4552# ('-') in such cases. Not all macros have been tested.
4553#
4554# One or more Squid ACLs may be specified to restrict header
4555# injection to matching requests. As always in squid.conf, all
4556# ACLs in an option ACL list must be satisfied for the insertion
4557# to happen. The request_header_add option supports fast ACLs
4558# only.
4559#Default:
4560# none
4561
4562# TAG: relaxed_header_parser on|off|warn
4563# In the default "on" setting Squid accepts certain forms
4564# of non-compliant HTTP messages where it is unambiguous
4565# what the sending application intended even if the message
4566# is not correctly formatted. The messages is then normalized
4567# to the correct form when forwarded by Squid.
4568#
4569# If set to "warn" then a warning will be emitted in cache.log
4570# each time such HTTP error is encountered.
4571#
4572# If set to "off" then such HTTP errors will cause the request
4573# or response to be rejected.
4574#Default:
4575# relaxed_header_parser on
4576
4577# TIMEOUTS
4578# -----------------------------------------------------------------------------
4579
4580# TAG: forward_timeout time-units
4581# This parameter specifies how long Squid should at most attempt in
4582# finding a forwarding path for the request before giving up.
4583#Default:
4584# forward_timeout 4 minutes
4585
4586# TAG: connect_timeout time-units
4587# This parameter specifies how long to wait for the TCP connect to
4588# the requested server or peer to complete before Squid should
4589# attempt to find another path where to forward the request.
4590#Default:
4591# connect_timeout 1 minute
4592
4593# TAG: peer_connect_timeout time-units
4594# This parameter specifies how long to wait for a pending TCP
4595# connection to a peer cache. The default is 30 seconds. You
4596# may also set different timeout values for individual neighbors
4597# with the 'connect-timeout' option on a 'cache_peer' line.
4598#Default:
4599# peer_connect_timeout 30 seconds
4600
4601# TAG: read_timeout time-units
4602# The read_timeout is applied on server-side connections. After
4603# each successful read(), the timeout will be extended by this
4604# amount. If no data is read again after this amount of time,
4605# the request is aborted and logged with ERR_READ_TIMEOUT. The
4606# default is 15 minutes.
4607#Default:
4608# read_timeout 15 minutes
4609
4610# TAG: write_timeout time-units
4611# This timeout is tracked for all connections that have data
4612# available for writing and are waiting for the socket to become
4613# ready. After each successful write, the timeout is extended by
4614# the configured amount. If Squid has data to write but the
4615# connection is not ready for the configured duration, the
4616# transaction associated with the connection is terminated. The
4617# default is 15 minutes.
4618#Default:
4619# write_timeout 15 minutes
4620
4621# TAG: request_timeout
4622# How long to wait for complete HTTP request headers after initial
4623# connection establishment.
4624#Default:
4625# request_timeout 5 minutes
4626
4627# TAG: client_idle_pconn_timeout
4628# How long to wait for the next HTTP request on a persistent
4629# client connection after the previous request completes.
4630#Default:
4631# client_idle_pconn_timeout 2 minutes
4632
4633# TAG: client_lifetime time-units
4634# The maximum amount of time a client (browser) is allowed to
4635# remain connected to the cache process. This protects the Cache
4636# from having a lot of sockets (and hence file descriptors) tied up
4637# in a CLOSE_WAIT state from remote clients that go away without
4638# properly shutting down (either because of a network failure or
4639# because of a poor client implementation). The default is one
4640# day, 1440 minutes.
4641#
4642# NOTE: The default value is intended to be much larger than any
4643# client would ever need to be connected to your cache. You
4644# should probably change client_lifetime only as a last resort.
4645# If you seem to have many client connections tying up
4646# filedescriptors, we recommend first tuning the read_timeout,
4647# request_timeout, persistent_request_timeout and quick_abort values.
4648#Default:
4649# client_lifetime 1 day
4650
4651# TAG: half_closed_clients
4652# Some clients may shutdown the sending side of their TCP
4653# connections, while leaving their receiving sides open. Sometimes,
4654# Squid can not tell the difference between a half-closed and a
4655# fully-closed TCP connection.
4656#
4657# By default, Squid will immediately close client connections when
4658# read(2) returns "no more data to read."
4659#
4660# Change this option to 'on' and Squid will keep open connections
4661# until a read(2) or write(2) on the socket returns an error.
4662# This may show some benefits for reverse proxies. But if not
4663# it is recommended to leave OFF.
4664#Default:
4665# half_closed_clients off
4666
4667# TAG: server_idle_pconn_timeout
4668# Timeout for idle persistent connections to servers and other
4669# proxies.
4670#Default:
4671# server_idle_pconn_timeout 1 minute
4672
4673# TAG: ident_timeout
4674# Maximum time to wait for IDENT lookups to complete.
4675#
4676# If this is too high, and you enabled IDENT lookups from untrusted
4677# users, you might be susceptible to denial-of-service by having
4678# many ident requests going at once.
4679#Default:
4680# ident_timeout 10 seconds
4681
4682# TAG: shutdown_lifetime time-units
4683# When SIGTERM or SIGHUP is received, the cache is put into
4684# "shutdown pending" mode until all active sockets are closed.
4685# This value is the lifetime to set for all open descriptors
4686# during shutdown mode. Any active clients after this many
4687# seconds will receive a 'timeout' message.
4688#Default:
4689# shutdown_lifetime 30 seconds
4690
4691# ADMINISTRATIVE PARAMETERS
4692# -----------------------------------------------------------------------------
4693
4694# TAG: cache_mgr
4695# Email-address of local cache manager who will receive
4696# mail if the cache dies. The default is "webmaster".
4697#Default:
4698# cache_mgr webmaster
4699
4700# TAG: mail_from
4701# From: email-address for mail sent when the cache dies.
4702# The default is to use 'squid@unique_hostname'.
4703#
4704# See also: unique_hostname directive.
4705#Default:
4706# none
4707
4708# TAG: mail_program
4709# Email program used to send mail if the cache dies.
4710# The default is "mail". The specified program must comply
4711# with the standard Unix mail syntax:
4712# mail-program recipient < mailfile
4713#
4714# Optional command line options can be specified.
4715#Default:
4716# mail_program mail
4717
4718# TAG: cache_effective_user
4719# If you start Squid as root, it will change its effective/real
4720# UID/GID to the user specified below. The default is to change
4721# to UID of proxy.
4722# see also; cache_effective_group
4723#Default:
4724# cache_effective_user proxy
4725
4726# TAG: cache_effective_group
4727# Squid sets the GID to the effective user's default group ID
4728# (taken from the password file) and supplementary group list
4729# from the groups membership.
4730#
4731# If you want Squid to run with a specific GID regardless of
4732# the group memberships of the effective user then set this
4733# to the group (or GID) you want Squid to run as. When set
4734# all other group privileges of the effective user are ignored
4735# and only this GID is effective. If Squid is not started as
4736# root the user starting Squid MUST be member of the specified
4737# group.
4738#
4739# This option is not recommended by the Squid Team.
4740# Our preference is for administrators to configure a secure
4741# user account for squid with UID/GID matching system policies.
4742#Default:
4743# Use system group memberships of the cache_effective_user account
4744
4745# TAG: httpd_suppress_version_string on|off
4746# Suppress Squid version string info in HTTP headers and HTML error pages.
4747#Default:
4748# httpd_suppress_version_string off
4749
4750# TAG: visible_hostname
4751# If you want to present a special hostname in error messages, etc,
4752# define this. Otherwise, the return value of gethostname()
4753# will be used. If you have multiple caches in a cluster and
4754# get errors about IP-forwarding you must set them to have individual
4755# names with this setting.
4756#Default:
4757# Automatically detect the system host name
4758
4759# TAG: unique_hostname
4760# If you want to have multiple machines with the same
4761# 'visible_hostname' you must give each machine a different
4762# 'unique_hostname' so forwarding loops can be detected.
4763#Default:
4764# Copy the value from visible_hostname
4765
4766# TAG: hostname_aliases
4767# A list of other DNS names your cache has.
4768#Default:
4769# none
4770
4771# TAG: umask
4772# Minimum umask which should be enforced while the proxy
4773# is running, in addition to the umask set at startup.
4774#
4775# For a traditional octal representation of umasks, start
4776# your value with 0.
4777#Default:
4778# umask 027
4779
4780# OPTIONS FOR THE CACHE REGISTRATION SERVICE
4781# -----------------------------------------------------------------------------
4782#
4783# This section contains parameters for the (optional) cache
4784# announcement service. This service is provided to help
4785# cache administrators locate one another in order to join or
4786# create cache hierarchies.
4787#
4788# An 'announcement' message is sent (via UDP) to the registration
4789# service by Squid. By default, the announcement message is NOT
4790# SENT unless you enable it with 'announce_period' below.
4791#
4792# The announcement message includes your hostname, plus the
4793# following information from this configuration file:
4794#
4795# http_port
4796# icp_port
4797# cache_mgr
4798#
4799# All current information is processed regularly and made
4800# available on the Web at http://www.ircache.net/Cache/Tracker/.
4801
4802# TAG: announce_period
4803# This is how frequently to send cache announcements.
4804#
4805# To enable announcing your cache, just set an announce period.
4806#
4807# Example:
4808# announce_period 1 day
4809#Default:
4810# Announcement messages disabled.
4811
4812# TAG: announce_host
4813# Set the hostname where announce registration messages will be sent.
4814#
4815# See also announce_port and announce_file
4816#Default:
4817# announce_host tracker.ircache.net
4818
4819# TAG: announce_file
4820# The contents of this file will be included in the announce
4821# registration messages.
4822#Default:
4823# none
4824
4825# TAG: announce_port
4826# Set the port where announce registration messages will be sent.
4827#
4828# See also announce_host and announce_file
4829#Default:
4830# announce_port 3131
4831
4832# HTTPD-ACCELERATOR OPTIONS
4833# -----------------------------------------------------------------------------
4834
4835# TAG: httpd_accel_surrogate_id
4836# Surrogates (http://www.esi.org/architecture_spec_1.0.html)
4837# need an identification token to allow control targeting. Because
4838# a farm of surrogates may all perform the same tasks, they may share
4839# an identification token.
4840#Default:
4841# visible_hostname is used if no specific ID is set.
4842
4843# TAG: http_accel_surrogate_remote on|off
4844# Remote surrogates (such as those in a CDN) honour the header
4845# "Surrogate-Control: no-store-remote".
4846#
4847# Set this to on to have squid behave as a remote surrogate.
4848#Default:
4849# http_accel_surrogate_remote off
4850
4851# TAG: esi_parser libxml2|expat|custom
4852# ESI markup is not strictly XML compatible. The custom ESI parser
4853# will give higher performance, but cannot handle non ASCII character
4854# encodings.
4855#Default:
4856# esi_parser custom
4857
4858# DELAY POOL PARAMETERS
4859# -----------------------------------------------------------------------------
4860
4861# TAG: delay_pools
4862# This represents the number of delay pools to be used. For example,
4863# if you have one class 2 delay pool and one class 3 delays pool, you
4864# have a total of 2 delay pools.
4865#
4866# See also delay_parameters, delay_class, delay_access for pool
4867# configuration details.
4868#Default:
4869# delay_pools 0
4870
4871# TAG: delay_class
4872# This defines the class of each delay pool. There must be exactly one
4873# delay_class line for each delay pool. For example, to define two
4874# delay pools, one of class 2 and one of class 3, the settings above
4875# and here would be:
4876#
4877# Example:
4878# delay_pools 4 # 4 delay pools
4879# delay_class 1 2 # pool 1 is a class 2 pool
4880# delay_class 2 3 # pool 2 is a class 3 pool
4881# delay_class 3 4 # pool 3 is a class 4 pool
4882# delay_class 4 5 # pool 4 is a class 5 pool
4883#
4884# The delay pool classes are:
4885#
4886# class 1 Everything is limited by a single aggregate
4887# bucket.
4888#
4889# class 2 Everything is limited by a single aggregate
4890# bucket as well as an "individual" bucket chosen
4891# from bits 25 through 32 of the IPv4 address.
4892#
4893# class 3 Everything is limited by a single aggregate
4894# bucket as well as a "network" bucket chosen
4895# from bits 17 through 24 of the IP address and a
4896# "individual" bucket chosen from bits 17 through
4897# 32 of the IPv4 address.
4898#
4899# class 4 Everything in a class 3 delay pool, with an
4900# additional limit on a per user basis. This
4901# only takes effect if the username is established
4902# in advance - by forcing authentication in your
4903# http_access rules.
4904#
4905# class 5 Requests are grouped according their tag (see
4906# external_acl's tag= reply).
4907#
4908#
4909# Each pool also requires a delay_parameters directive to configure the pool size
4910# and speed limits used whenever the pool is applied to a request. Along with
4911# a set of delay_access directives to determine when it is used.
4912#
4913# NOTE: If an IP address is a.b.c.d
4914# -> bits 25 through 32 are "d"
4915# -> bits 17 through 24 are "c"
4916# -> bits 17 through 32 are "c * 256 + d"
4917#
4918# NOTE-2: Due to the use of bitmasks in class 2,3,4 pools they only apply to
4919# IPv4 traffic. Class 1 and 5 pools may be used with IPv6 traffic.
4920#
4921# This clause only supports fast acl types.
4922# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4923#
4924# See also delay_parameters and delay_access.
4925#Default:
4926# none
4927
4928# TAG: delay_access
4929# This is used to determine which delay pool a request falls into.
4930#
4931# delay_access is sorted per pool and the matching starts with pool 1,
4932# then pool 2, ..., and finally pool N. The first delay pool where the
4933# request is allowed is selected for the request. If it does not allow
4934# the request to any pool then the request is not delayed (default).
4935#
4936# For example, if you want some_big_clients in delay
4937# pool 1 and lotsa_little_clients in delay pool 2:
4938#
4939# delay_access 1 allow some_big_clients
4940# delay_access 1 deny all
4941# delay_access 2 allow lotsa_little_clients
4942# delay_access 2 deny all
4943# delay_access 3 allow authenticated_clients
4944#
4945# See also delay_parameters and delay_class.
4946#
4947#Default:
4948# Deny using the pool, unless allow rules exist in squid.conf for the pool.
4949
4950# TAG: delay_parameters
4951# This defines the parameters for a delay pool. Each delay pool has
4952# a number of "buckets" associated with it, as explained in the
4953# description of delay_class.
4954#
4955# For a class 1 delay pool, the syntax is:
4956# delay_pools pool 1
4957# delay_parameters pool aggregate
4958#
4959# For a class 2 delay pool:
4960# delay_pools pool 2
4961# delay_parameters pool aggregate individual
4962#
4963# For a class 3 delay pool:
4964# delay_pools pool 3
4965# delay_parameters pool aggregate network individual
4966#
4967# For a class 4 delay pool:
4968# delay_pools pool 4
4969# delay_parameters pool aggregate network individual user
4970#
4971# For a class 5 delay pool:
4972# delay_pools pool 5
4973# delay_parameters pool tagrate
4974#
4975# The option variables are:
4976#
4977# pool a pool number - ie, a number between 1 and the
4978# number specified in delay_pools as used in
4979# delay_class lines.
4980#
4981# aggregate the speed limit parameters for the aggregate bucket
4982# (class 1, 2, 3).
4983#
4984# individual the speed limit parameters for the individual
4985# buckets (class 2, 3).
4986#
4987# network the speed limit parameters for the network buckets
4988# (class 3).
4989#
4990# user the speed limit parameters for the user buckets
4991# (class 4).
4992#
4993# tagrate the speed limit parameters for the tag buckets
4994# (class 5).
4995#
4996# A pair of delay parameters is written restore/maximum, where restore is
4997# the number of bytes (not bits - modem and network speeds are usually
4998# quoted in bits) per second placed into the bucket, and maximum is the
4999# maximum number of bytes which can be in the bucket at any time.
5000#
5001# There must be one delay_parameters line for each delay pool.
5002#
5003#
5004# For example, if delay pool number 1 is a class 2 delay pool as in the
5005# above example, and is being used to strictly limit each host to 64Kbit/sec
5006# (plus overheads), with no overall limit, the line is:
5007#
5008# delay_parameters 1 -1/-1 8000/8000
5009#
5010# Note that 8 x 8000 KByte/sec -> 64Kbit/sec.
5011#
5012# Note that the figure -1 is used to represent "unlimited".
5013#
5014#
5015# And, if delay pool number 2 is a class 3 delay pool as in the above
5016# example, and you want to limit it to a total of 256Kbit/sec (strict limit)
5017# with each 8-bit network permitted 64Kbit/sec (strict limit) and each
5018# individual host permitted 4800bit/sec with a bucket maximum size of 64Kbits
5019# to permit a decent web page to be downloaded at a decent speed
5020# (if the network is not being limited due to overuse) but slow down
5021# large downloads more significantly:
5022#
5023# delay_parameters 2 32000/32000 8000/8000 600/8000
5024#
5025# Note that 8 x 32000 KByte/sec -> 256Kbit/sec.
5026# 8 x 8000 KByte/sec -> 64Kbit/sec.
5027# 8 x 600 Byte/sec -> 4800bit/sec.
5028#
5029#
5030# Finally, for a class 4 delay pool as in the example - each user will
5031# be limited to 128Kbits/sec no matter how many workstations they are logged into.:
5032#
5033# delay_parameters 4 32000/32000 8000/8000 600/64000 16000/16000
5034#
5035#
5036# See also delay_class and delay_access.
5037#
5038#Default:
5039# none
5040
5041# TAG: delay_initial_bucket_level (percent, 0-100)
5042# The initial bucket percentage is used to determine how much is put
5043# in each bucket when squid starts, is reconfigured, or first notices
5044# a host accessing it (in class 2 and class 3, individual hosts and
5045# networks only have buckets associated with them once they have been
5046# "seen" by squid).
5047#Default:
5048# delay_initial_bucket_level 50
5049
5050# CLIENT DELAY POOL PARAMETERS
5051# -----------------------------------------------------------------------------
5052
5053# TAG: client_delay_pools
5054# This option specifies the number of client delay pools used. It must
5055# preceed other client_delay_* options.
5056#
5057# Example:
5058# client_delay_pools 2
5059#
5060# See also client_delay_parameters and client_delay_access.
5061#Default:
5062# client_delay_pools 0
5063
5064# TAG: client_delay_initial_bucket_level (percent, 0-no_limit)
5065# This option determines the initial bucket size as a percentage of
5066# max_bucket_size from client_delay_parameters. Buckets are created
5067# at the time of the "first" connection from the matching IP. Idle
5068# buckets are periodically deleted up.
5069#
5070# You can specify more than 100 percent but note that such "oversized"
5071# buckets are not refilled until their size goes down to max_bucket_size
5072# from client_delay_parameters.
5073#
5074# Example:
5075# client_delay_initial_bucket_level 50
5076#Default:
5077# client_delay_initial_bucket_level 50
5078
5079# TAG: client_delay_parameters
5080#
5081# This option configures client-side bandwidth limits using the
5082# following format:
5083#
5084# client_delay_parameters pool speed_limit max_bucket_size
5085#
5086# pool is an integer ID used for client_delay_access matching.
5087#
5088# speed_limit is bytes added to the bucket per second.
5089#
5090# max_bucket_size is the maximum size of a bucket, enforced after any
5091# speed_limit additions.
5092#
5093# Please see the delay_parameters option for more information and
5094# examples.
5095#
5096# Example:
5097# client_delay_parameters 1 1024 2048
5098# client_delay_parameters 2 51200 16384
5099#
5100# See also client_delay_access.
5101#
5102#Default:
5103# none
5104
5105# TAG: client_delay_access
5106# This option determines the client-side delay pool for the
5107# request:
5108#
5109# client_delay_access pool_ID allow|deny acl_name
5110#
5111# All client_delay_access options are checked in their pool ID
5112# order, starting with pool 1. The first checked pool with allowed
5113# request is selected for the request. If no ACL matches or there
5114# are no client_delay_access options, the request bandwidth is not
5115# limited.
5116#
5117# The ACL-selected pool is then used to find the
5118# client_delay_parameters for the request. Client-side pools are
5119# not used to aggregate clients. Clients are always aggregated
5120# based on their source IP addresses (one bucket per source IP).
5121#
5122# This clause only supports fast acl types.
5123# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5124# Additionally, only the client TCP connection details are available.
5125# ACLs testing HTTP properties will not work.
5126#
5127# Please see delay_access for more examples.
5128#
5129# Example:
5130# client_delay_access 1 allow low_rate_network
5131# client_delay_access 2 allow vips_network
5132#
5133#
5134# See also client_delay_parameters and client_delay_pools.
5135#Default:
5136# Deny use of the pool, unless allow rules exist in squid.conf for the pool.
5137
5138# WCCPv1 AND WCCPv2 CONFIGURATION OPTIONS
5139# -----------------------------------------------------------------------------
5140
5141# TAG: wccp_router
5142# Use this option to define your WCCP ``home'' router for
5143# Squid.
5144#
5145# wccp_router supports a single WCCP(v1) router
5146#
5147# wccp2_router supports multiple WCCPv2 routers
5148#
5149# only one of the two may be used at the same time and defines
5150# which version of WCCP to use.
5151#Default:
5152# WCCP disabled.
5153
5154# TAG: wccp2_router
5155# Use this option to define your WCCP ``home'' router for
5156# Squid.
5157#
5158# wccp_router supports a single WCCP(v1) router
5159#
5160# wccp2_router supports multiple WCCPv2 routers
5161#
5162# only one of the two may be used at the same time and defines
5163# which version of WCCP to use.
5164#Default:
5165# WCCPv2 disabled.
5166
5167# TAG: wccp_version
5168# This directive is only relevant if you need to set up WCCP(v1)
5169# to some very old and end-of-life Cisco routers. In all other
5170# setups it must be left unset or at the default setting.
5171# It defines an internal version in the WCCP(v1) protocol,
5172# with version 4 being the officially documented protocol.
5173#
5174# According to some users, Cisco IOS 11.2 and earlier only
5175# support WCCP version 3. If you're using that or an earlier
5176# version of IOS, you may need to change this value to 3, otherwise
5177# do not specify this parameter.
5178#Default:
5179# wccp_version 4
5180
5181# TAG: wccp2_rebuild_wait
5182# If this is enabled Squid will wait for the cache dir rebuild to finish
5183# before sending the first wccp2 HereIAm packet
5184#Default:
5185# wccp2_rebuild_wait on
5186
5187# TAG: wccp2_forwarding_method
5188# WCCP2 allows the setting of forwarding methods between the
5189# router/switch and the cache. Valid values are as follows:
5190#
5191# gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
5192# l2 - L2 redirect (forward the packet using Layer 2/MAC rewriting)
5193#
5194# Currently (as of IOS 12.4) cisco routers only support GRE.
5195# Cisco switches only support the L2 redirect assignment method.
5196#Default:
5197# wccp2_forwarding_method gre
5198
5199# TAG: wccp2_return_method
5200# WCCP2 allows the setting of return methods between the
5201# router/switch and the cache for packets that the cache
5202# decides not to handle. Valid values are as follows:
5203#
5204# gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
5205# l2 - L2 redirect (forward the packet using Layer 2/MAC rewriting)
5206#
5207# Currently (as of IOS 12.4) cisco routers only support GRE.
5208# Cisco switches only support the L2 redirect assignment.
5209#
5210# If the "ip wccp redirect exclude in" command has been
5211# enabled on the cache interface, then it is still safe for
5212# the proxy server to use a l2 redirect method even if this
5213# option is set to GRE.
5214#Default:
5215# wccp2_return_method gre
5216
5217# TAG: wccp2_assignment_method
5218# WCCP2 allows the setting of methods to assign the WCCP hash
5219# Valid values are as follows:
5220#
5221# hash - Hash assignment
5222# mask - Mask assignment
5223#
5224# As a general rule, cisco routers support the hash assignment method
5225# and cisco switches support the mask assignment method.
5226#Default:
5227# wccp2_assignment_method hash
5228
5229# TAG: wccp2_service
5230# WCCP2 allows for multiple traffic services. There are two
5231# types: "standard" and "dynamic". The standard type defines
5232# one service id - http (id 0). The dynamic service ids can be from
5233# 51 to 255 inclusive. In order to use a dynamic service id
5234# one must define the type of traffic to be redirected; this is done
5235# using the wccp2_service_info option.
5236#
5237# The "standard" type does not require a wccp2_service_info option,
5238# just specifying the service id will suffice.
5239#
5240# MD5 service authentication can be enabled by adding
5241# "password=<password>" to the end of this service declaration.
5242#
5243# Examples:
5244#
5245# wccp2_service standard 0 # for the 'web-cache' standard service
5246# wccp2_service dynamic 80 # a dynamic service type which will be
5247# # fleshed out with subsequent options.
5248# wccp2_service standard 0 password=foo
5249#Default:
5250# Use the 'web-cache' standard service.
5251
5252# TAG: wccp2_service_info
5253# Dynamic WCCPv2 services require further information to define the
5254# traffic you wish to have diverted.
5255#
5256# The format is:
5257#
5258# wccp2_service_info <id> protocol=<protocol> flags=<flag>,<flag>..
5259# priority=<priority> ports=<port>,<port>..
5260#
5261# The relevant WCCPv2 flags:
5262# + src_ip_hash, dst_ip_hash
5263# + source_port_hash, dst_port_hash
5264# + src_ip_alt_hash, dst_ip_alt_hash
5265# + src_port_alt_hash, dst_port_alt_hash
5266# + ports_source
5267#
5268# The port list can be one to eight entries.
5269#
5270# Example:
5271#
5272# wccp2_service_info 80 protocol=tcp flags=src_ip_hash,ports_source
5273# priority=240 ports=80
5274#
5275# Note: the service id must have been defined by a previous
5276# 'wccp2_service dynamic <id>' entry.
5277#Default:
5278# none
5279
5280# TAG: wccp2_weight
5281# Each cache server gets assigned a set of the destination
5282# hash proportional to their weight.
5283#Default:
5284# wccp2_weight 10000
5285
5286# TAG: wccp_address
5287# Use this option if you require WCCPv2 to use a specific
5288# interface address.
5289#
5290# The default behavior is to not bind to any specific address.
5291#Default:
5292# Address selected by the operating system.
5293
5294# TAG: wccp2_address
5295# Use this option if you require WCCP to use a specific
5296# interface address.
5297#
5298# The default behavior is to not bind to any specific address.
5299#Default:
5300# Address selected by the operating system.
5301
5302# PERSISTENT CONNECTION HANDLING
5303# -----------------------------------------------------------------------------
5304#
5305# Also see "pconn_timeout" in the TIMEOUTS section
5306
5307# TAG: client_persistent_connections
5308# Persistent connection support for clients.
5309# Squid uses persistent connections (when allowed). You can use
5310# this option to disable persistent connections with clients.
5311#Default:
5312# client_persistent_connections on
5313
5314# TAG: server_persistent_connections
5315# Persistent connection support for servers.
5316# Squid uses persistent connections (when allowed). You can use
5317# this option to disable persistent connections with servers.
5318#Default:
5319# server_persistent_connections on
5320
5321# TAG: persistent_connection_after_error
5322# With this directive the use of persistent connections after
5323# HTTP errors can be disabled. Useful if you have clients
5324# who fail to handle errors on persistent connections proper.
5325#Default:
5326# persistent_connection_after_error on
5327
5328# TAG: detect_broken_pconn
5329# Some servers have been found to incorrectly signal the use
5330# of HTTP/1.0 persistent connections even on replies not
5331# compatible, causing significant delays. This server problem
5332# has mostly been seen on redirects.
5333#
5334# By enabling this directive Squid attempts to detect such
5335# broken replies and automatically assume the reply is finished
5336# after 10 seconds timeout.
5337#Default:
5338# detect_broken_pconn off
5339
5340# CACHE DIGEST OPTIONS
5341# -----------------------------------------------------------------------------
5342
5343# TAG: digest_generation
5344# This controls whether the server will generate a Cache Digest
5345# of its contents. By default, Cache Digest generation is
5346# enabled if Squid is compiled with --enable-cache-digests defined.
5347#Default:
5348# digest_generation on
5349
5350# TAG: digest_bits_per_entry
5351# This is the number of bits of the server's Cache Digest which
5352# will be associated with the Digest entry for a given HTTP
5353# Method and URL (public key) combination. The default is 5.
5354#Default:
5355# digest_bits_per_entry 5
5356
5357# TAG: digest_rebuild_period (seconds)
5358# This is the wait time between Cache Digest rebuilds.
5359#Default:
5360# digest_rebuild_period 1 hour
5361
5362# TAG: digest_rewrite_period (seconds)
5363# This is the wait time between Cache Digest writes to
5364# disk.
5365#Default:
5366# digest_rewrite_period 1 hour
5367
5368# TAG: digest_swapout_chunk_size (bytes)
5369# This is the number of bytes of the Cache Digest to write to
5370# disk at a time. It defaults to 4096 bytes (4KB), the Squid
5371# default swap page.
5372#Default:
5373# digest_swapout_chunk_size 4096 bytes
5374
5375# TAG: digest_rebuild_chunk_percentage (percent, 0-100)
5376# This is the percentage of the Cache Digest to be scanned at a
5377# time. By default it is set to 10% of the Cache Digest.
5378#Default:
5379# digest_rebuild_chunk_percentage 10
5380
5381# SNMP OPTIONS
5382# -----------------------------------------------------------------------------
5383
5384# TAG: snmp_port
5385# The port number where Squid listens for SNMP requests. To enable
5386# SNMP support set this to a suitable port number. Port number
5387# 3401 is often used for the Squid SNMP agent. By default it's
5388# set to "0" (disabled)
5389#
5390# Example:
5391# snmp_port 3401
5392#Default:
5393# SNMP disabled.
5394
5395# TAG: snmp_access
5396# Allowing or denying access to the SNMP port.
5397#
5398# All access to the agent is denied by default.
5399# usage:
5400#
5401# snmp_access allow|deny [!]aclname ...
5402#
5403# This clause only supports fast acl types.
5404# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5405#
5406#Example:
5407# snmp_access allow snmppublic localhost
5408# snmp_access deny all
5409#Default:
5410# Deny, unless rules exist in squid.conf.
5411
5412# TAG: snmp_incoming_address
5413# Just like 'udp_incoming_address', but for the SNMP port.
5414#
5415# snmp_incoming_address is used for the SNMP socket receiving
5416# messages from SNMP agents.
5417#
5418# The default snmp_incoming_address is to listen on all
5419# available network interfaces.
5420#Default:
5421# Accept SNMP packets from all machine interfaces.
5422
5423# TAG: snmp_outgoing_address
5424# Just like 'udp_outgoing_address', but for the SNMP port.
5425#
5426# snmp_outgoing_address is used for SNMP packets returned to SNMP
5427# agents.
5428#
5429# If snmp_outgoing_address is not set it will use the same socket
5430# as snmp_incoming_address. Only change this if you want to have
5431# SNMP replies sent using another address than where this Squid
5432# listens for SNMP queries.
5433#
5434# NOTE, snmp_incoming_address and snmp_outgoing_address can not have
5435# the same value since they both use the same port.
5436#Default:
5437# Use snmp_incoming_address or an address selected by the operating system.
5438
5439# ICP OPTIONS
5440# -----------------------------------------------------------------------------
5441
5442# TAG: icp_port
5443# The port number where Squid sends and receives ICP queries to
5444# and from neighbor caches. The standard UDP port for ICP is 3130.
5445#
5446# Example:
5447# icp_port 3130
5448#Default:
5449# ICP disabled.
5450
5451# TAG: htcp_port
5452# The port number where Squid sends and receives HTCP queries to
5453# and from neighbor caches. To turn it on you want to set it to
5454# 4827.
5455#
5456# Example:
5457# htcp_port 4827
5458#Default:
5459# HTCP disabled.
5460
5461# TAG: log_icp_queries on|off
5462# If set, ICP queries are logged to access.log. You may wish
5463# do disable this if your ICP load is VERY high to speed things
5464# up or to simplify log analysis.
5465#Default:
5466# log_icp_queries on
5467
5468# TAG: udp_incoming_address
5469# udp_incoming_address is used for UDP packets received from other
5470# caches.
5471#
5472# The default behavior is to not bind to any specific address.
5473#
5474# Only change this if you want to have all UDP queries received on
5475# a specific interface/address.
5476#
5477# NOTE: udp_incoming_address is used by the ICP, HTCP, and DNS
5478# modules. Altering it will affect all of them in the same manner.
5479#
5480# see also; udp_outgoing_address
5481#
5482# NOTE, udp_incoming_address and udp_outgoing_address can not
5483# have the same value since they both use the same port.
5484#Default:
5485# Accept packets from all machine interfaces.
5486
5487# TAG: udp_outgoing_address
5488# udp_outgoing_address is used for UDP packets sent out to other
5489# caches.
5490#
5491# The default behavior is to not bind to any specific address.
5492#
5493# Instead it will use the same socket as udp_incoming_address.
5494# Only change this if you want to have UDP queries sent using another
5495# address than where this Squid listens for UDP queries from other
5496# caches.
5497#
5498# NOTE: udp_outgoing_address is used by the ICP, HTCP, and DNS
5499# modules. Altering it will affect all of them in the same manner.
5500#
5501# see also; udp_incoming_address
5502#
5503# NOTE, udp_incoming_address and udp_outgoing_address can not
5504# have the same value since they both use the same port.
5505#Default:
5506# Use udp_incoming_address or an address selected by the operating system.
5507
5508# TAG: icp_hit_stale on|off
5509# If you want to return ICP_HIT for stale cache objects, set this
5510# option to 'on'. If you have sibling relationships with caches
5511# in other administrative domains, this should be 'off'. If you only
5512# have sibling relationships with caches under your control,
5513# it is probably okay to set this to 'on'.
5514# If set to 'on', your siblings should use the option "allow-miss"
5515# on their cache_peer lines for connecting to you.
5516#Default:
5517# icp_hit_stale off
5518
5519# TAG: minimum_direct_hops
5520# If using the ICMP pinging stuff, do direct fetches for sites
5521# which are no more than this many hops away.
5522#Default:
5523# minimum_direct_hops 4
5524
5525# TAG: minimum_direct_rtt (msec)
5526# If using the ICMP pinging stuff, do direct fetches for sites
5527# which are no more than this many rtt milliseconds away.
5528#Default:
5529# minimum_direct_rtt 400
5530
5531# TAG: netdb_low
5532# The low water mark for the ICMP measurement database.
5533#
5534# Note: high watermark controlled by netdb_high directive.
5535#
5536# These watermarks are counts, not percents. The defaults are
5537# (low) 900 and (high) 1000. When the high water mark is
5538# reached, database entries will be deleted until the low
5539# mark is reached.
5540#Default:
5541# netdb_low 900
5542
5543# TAG: netdb_high
5544# The high water mark for the ICMP measurement database.
5545#
5546# Note: low watermark controlled by netdb_low directive.
5547#
5548# These watermarks are counts, not percents. The defaults are
5549# (low) 900 and (high) 1000. When the high water mark is
5550# reached, database entries will be deleted until the low
5551# mark is reached.
5552#Default:
5553# netdb_high 1000
5554
5555# TAG: netdb_ping_period
5556# The minimum period for measuring a site. There will be at
5557# least this much delay between successive pings to the same
5558# network. The default is five minutes.
5559#Default:
5560# netdb_ping_period 5 minutes
5561
5562# TAG: query_icmp on|off
5563# If you want to ask your peers to include ICMP data in their ICP
5564# replies, enable this option.
5565#
5566# If your peer has configured Squid (during compilation) with
5567# '--enable-icmp' that peer will send ICMP pings to origin server
5568# sites of the URLs it receives. If you enable this option the
5569# ICP replies from that peer will include the ICMP data (if available).
5570# Then, when choosing a parent cache, Squid will choose the parent with
5571# the minimal RTT to the origin server. When this happens, the
5572# hierarchy field of the access.log will be
5573# "CLOSEST_PARENT_MISS". This option is off by default.
5574#Default:
5575# query_icmp off
5576
5577# TAG: test_reachability on|off
5578# When this is 'on', ICP MISS replies will be ICP_MISS_NOFETCH
5579# instead of ICP_MISS if the target host is NOT in the ICMP
5580# database, or has a zero RTT.
5581#Default:
5582# test_reachability off
5583
5584# TAG: icp_query_timeout (msec)
5585# Normally Squid will automatically determine an optimal ICP
5586# query timeout value based on the round-trip-time of recent ICP
5587# queries. If you want to override the value determined by
5588# Squid, set this 'icp_query_timeout' to a non-zero value. This
5589# value is specified in MILLISECONDS, so, to use a 2-second
5590# timeout (the old default), you would write:
5591#
5592# icp_query_timeout 2000
5593#Default:
5594# Dynamic detection.
5595
5596# TAG: maximum_icp_query_timeout (msec)
5597# Normally the ICP query timeout is determined dynamically. But
5598# sometimes it can lead to very large values (say 5 seconds).
5599# Use this option to put an upper limit on the dynamic timeout
5600# value. Do NOT use this option to always use a fixed (instead
5601# of a dynamic) timeout value. To set a fixed timeout see the
5602# 'icp_query_timeout' directive.
5603#Default:
5604# maximum_icp_query_timeout 2000
5605
5606# TAG: minimum_icp_query_timeout (msec)
5607# Normally the ICP query timeout is determined dynamically. But
5608# sometimes it can lead to very small timeouts, even lower than
5609# the normal latency variance on your link due to traffic.
5610# Use this option to put an lower limit on the dynamic timeout
5611# value. Do NOT use this option to always use a fixed (instead
5612# of a dynamic) timeout value. To set a fixed timeout see the
5613# 'icp_query_timeout' directive.
5614#Default:
5615# minimum_icp_query_timeout 5
5616
5617# TAG: background_ping_rate time-units
5618# Controls how often the ICP pings are sent to siblings that
5619# have background-ping set.
5620#Default:
5621# background_ping_rate 10 seconds
5622
5623# MULTICAST ICP OPTIONS
5624# -----------------------------------------------------------------------------
5625
5626# TAG: mcast_groups
5627# This tag specifies a list of multicast groups which your server
5628# should join to receive multicasted ICP queries.
5629#
5630# NOTE! Be very careful what you put here! Be sure you
5631# understand the difference between an ICP _query_ and an ICP
5632# _reply_. This option is to be set only if you want to RECEIVE
5633# multicast queries. Do NOT set this option to SEND multicast
5634# ICP (use cache_peer for that). ICP replies are always sent via
5635# unicast, so this option does not affect whether or not you will
5636# receive replies from multicast group members.
5637#
5638# You must be very careful to NOT use a multicast address which
5639# is already in use by another group of caches.
5640#
5641# If you are unsure about multicast, please read the Multicast
5642# chapter in the Squid FAQ (http://www.squid-cache.org/FAQ/).
5643#
5644# Usage: mcast_groups 239.128.16.128 224.0.1.20
5645#
5646# By default, Squid doesn't listen on any multicast groups.
5647#Default:
5648# none
5649
5650# TAG: mcast_miss_addr
5651# Note: This option is only available if Squid is rebuilt with the
5652# -DMULTICAST_MISS_STREAM define
5653#
5654# If you enable this option, every "cache miss" URL will
5655# be sent out on the specified multicast address.
5656#
5657# Do not enable this option unless you are are absolutely
5658# certain you understand what you are doing.
5659#Default:
5660# disabled.
5661
5662# TAG: mcast_miss_ttl
5663# Note: This option is only available if Squid is rebuilt with the
5664# -DMULTICAST_MISS_STREAM define
5665#
5666# This is the time-to-live value for packets multicasted
5667# when multicasting off cache miss URLs is enabled. By
5668# default this is set to 'site scope', i.e. 16.
5669#Default:
5670# mcast_miss_ttl 16
5671
5672# TAG: mcast_miss_port
5673# Note: This option is only available if Squid is rebuilt with the
5674# -DMULTICAST_MISS_STREAM define
5675#
5676# This is the port number to be used in conjunction with
5677# 'mcast_miss_addr'.
5678#Default:
5679# mcast_miss_port 3135
5680
5681# TAG: mcast_miss_encode_key
5682# Note: This option is only available if Squid is rebuilt with the
5683# -DMULTICAST_MISS_STREAM define
5684#
5685# The URLs that are sent in the multicast miss stream are
5686# encrypted. This is the encryption key.
5687#Default:
5688# mcast_miss_encode_key XXXXXXXXXXXXXXXX
5689
5690# TAG: mcast_icp_query_timeout (msec)
5691# For multicast peers, Squid regularly sends out ICP "probes" to
5692# count how many other peers are listening on the given multicast
5693# address. This value specifies how long Squid should wait to
5694# count all the replies. The default is 2000 msec, or 2
5695# seconds.
5696#Default:
5697# mcast_icp_query_timeout 2000
5698
5699# INTERNAL ICON OPTIONS
5700# -----------------------------------------------------------------------------
5701
5702# TAG: icon_directory
5703# Where the icons are stored. These are normally kept in
5704# /usr/share/squid3/icons
5705#Default:
5706# icon_directory /usr/share/squid3/icons
5707
5708# TAG: global_internal_static
5709# This directive controls is Squid should intercept all requests for
5710# /squid-internal-static/ no matter which host the URL is requesting
5711# (default on setting), or if nothing special should be done for
5712# such URLs (off setting). The purpose of this directive is to make
5713# icons etc work better in complex cache hierarchies where it may
5714# not always be possible for all corners in the cache mesh to reach
5715# the server generating a directory listing.
5716#Default:
5717# global_internal_static on
5718
5719# TAG: short_icon_urls
5720# If this is enabled Squid will use short URLs for icons.
5721# If disabled it will revert to the old behavior of including
5722# it's own name and port in the URL.
5723#
5724# If you run a complex cache hierarchy with a mix of Squid and
5725# other proxies you may need to disable this directive.
5726#Default:
5727# short_icon_urls on
5728
5729# ERROR PAGE OPTIONS
5730# -----------------------------------------------------------------------------
5731
5732# TAG: error_directory
5733# If you wish to create your own versions of the default
5734# error files to customize them to suit your company copy
5735# the error/template files to another directory and point
5736# this tag at them.
5737#
5738# WARNING: This option will disable multi-language support
5739# on error pages if used.
5740#
5741# The squid developers are interested in making squid available in
5742# a wide variety of languages. If you are making translations for a
5743# language that Squid does not currently provide please consider
5744# contributing your translation back to the project.
5745# http://wiki.squid-cache.org/Translations
5746#
5747# The squid developers working on translations are happy to supply drop-in
5748# translated error files in exchange for any new language contributions.
5749#Default:
5750# Send error pages in the clients preferred language
5751
5752# TAG: error_default_language
5753# Set the default language which squid will send error pages in
5754# if no existing translation matches the clients language
5755# preferences.
5756#
5757# If unset (default) generic English will be used.
5758#
5759# The squid developers are interested in making squid available in
5760# a wide variety of languages. If you are interested in making
5761# translations for any language see the squid wiki for details.
5762# http://wiki.squid-cache.org/Translations
5763#Default:
5764# Generate English language pages.
5765
5766# TAG: error_log_languages
5767# Log to cache.log what languages users are attempting to
5768# auto-negotiate for translations.
5769#
5770# Successful negotiations are not logged. Only failures
5771# have meaning to indicate that Squid may need an upgrade
5772# of its error page translations.
5773#Default:
5774# error_log_languages on
5775
5776# TAG: err_page_stylesheet
5777# CSS Stylesheet to pattern the display of Squid default error pages.
5778#
5779# For information on CSS see http://www.w3.org/Style/CSS/
5780#Default:
5781# err_page_stylesheet /etc/squid3/errorpage.css
5782
5783# TAG: err_html_text
5784# HTML text to include in error messages. Make this a "mailto"
5785# URL to your admin address, or maybe just a link to your
5786# organizations Web page.
5787#
5788# To include this in your error messages, you must rewrite
5789# the error template files (found in the "errors" directory).
5790# Wherever you want the 'err_html_text' line to appear,
5791# insert a %L tag in the error template file.
5792#Default:
5793# none
5794
5795# TAG: email_err_data on|off
5796# If enabled, information about the occurred error will be
5797# included in the mailto links of the ERR pages (if %W is set)
5798# so that the email body contains the data.
5799# Syntax is <A HREF="mailto:%w%W">%w</A>
5800#Default:
5801# email_err_data on
5802
5803# TAG: deny_info
5804# Usage: deny_info err_page_name acl
5805# or deny_info http://... acl
5806# or deny_info TCP_RESET acl
5807#
5808# This can be used to return a ERR_ page for requests which
5809# do not pass the 'http_access' rules. Squid remembers the last
5810# acl it evaluated in http_access, and if a 'deny_info' line exists
5811# for that ACL Squid returns a corresponding error page.
5812#
5813# The acl is typically the last acl on the http_access deny line which
5814# denied access. The exceptions to this rule are:
5815# - When Squid needs to request authentication credentials. It's then
5816# the first authentication related acl encountered
5817# - When none of the http_access lines matches. It's then the last
5818# acl processed on the last http_access line.
5819# - When the decision to deny access was made by an adaptation service,
5820# the acl name is the corresponding eCAP or ICAP service_name.
5821#
5822# NP: If providing your own custom error pages with error_directory
5823# you may also specify them by your custom file name:
5824# Example: deny_info ERR_CUSTOM_ACCESS_DENIED bad_guys
5825#
5826# By defaut Squid will send "403 Forbidden". A different 4xx or 5xx
5827# may be specified by prefixing the file name with the code and a colon.
5828# e.g. 404:ERR_CUSTOM_ACCESS_DENIED
5829#
5830# Alternatively you can tell Squid to reset the TCP connection
5831# by specifying TCP_RESET.
5832#
5833# Or you can specify an error URL or URL pattern. The browsers will
5834# get redirected to the specified URL after formatting tags have
5835# been replaced. Redirect will be done with 302 or 307 according to
5836# HTTP/1.1 specs. A different 3xx code may be specified by prefixing
5837# the URL. e.g. 303:http://example.com/
5838#
5839# URL FORMAT TAGS:
5840# %a - username (if available. Password NOT included)
5841# %B - FTP path URL
5842# %e - Error number
5843# %E - Error description
5844# %h - Squid hostname
5845# %H - Request domain name
5846# %i - Client IP Address
5847# %M - Request Method
5848# %o - Message result from external ACL helper
5849# %p - Request Port number
5850# %P - Request Protocol name
5851# %R - Request URL path
5852# %T - Timestamp in RFC 1123 format
5853# %U - Full canonical URL from client
5854# (HTTPS URLs terminate with *)
5855# %u - Full canonical URL from client
5856# %w - Admin email from squid.conf
5857# %x - Error name
5858# %% - Literal percent (%) code
5859#
5860#Default:
5861# none
5862
5863# OPTIONS INFLUENCING REQUEST FORWARDING
5864# -----------------------------------------------------------------------------
5865
5866# TAG: nonhierarchical_direct
5867# By default, Squid will send any non-hierarchical requests
5868# (matching hierarchy_stoplist or not cacheable request type) direct
5869# to origin servers.
5870#
5871# When this is set to "off", Squid will prefer to send these
5872# requests to parents.
5873#
5874# Note that in most configurations, by turning this off you will only
5875# add latency to these request without any improvement in global hit
5876# ratio.
5877#
5878# This option only sets a preference. If the parent is unavailable a
5879# direct connection to the origin server may still be attempted. To
5880# completely prevent direct connections use never_direct.
5881#Default:
5882# nonhierarchical_direct on
5883
5884# TAG: prefer_direct
5885# Normally Squid tries to use parents for most requests. If you for some
5886# reason like it to first try going direct and only use a parent if
5887# going direct fails set this to on.
5888#
5889# By combining nonhierarchical_direct off and prefer_direct on you
5890# can set up Squid to use a parent as a backup path if going direct
5891# fails.
5892#
5893# Note: If you want Squid to use parents for all requests see
5894# the never_direct directive. prefer_direct only modifies how Squid
5895# acts on cacheable requests.
5896#Default:
5897# prefer_direct off
5898
5899# TAG: always_direct
5900# Usage: always_direct allow|deny [!]aclname ...
5901#
5902# Here you can use ACL elements to specify requests which should
5903# ALWAYS be forwarded by Squid to the origin servers without using
5904# any peers. For example, to always directly forward requests for
5905# local servers ignoring any parents or siblings you may have use
5906# something like:
5907#
5908# acl local-servers dstdomain my.domain.net
5909# always_direct allow local-servers
5910#
5911# To always forward FTP requests directly, use
5912#
5913# acl FTP proto FTP
5914# always_direct allow FTP
5915#
5916# NOTE: There is a similar, but opposite option named
5917# 'never_direct'. You need to be aware that "always_direct deny
5918# foo" is NOT the same thing as "never_direct allow foo". You
5919# may need to use a deny rule to exclude a more-specific case of
5920# some other rule. Example:
5921#
5922# acl local-external dstdomain external.foo.net
5923# acl local-servers dstdomain .foo.net
5924# always_direct deny local-external
5925# always_direct allow local-servers
5926#
5927# NOTE: If your goal is to make the client forward the request
5928# directly to the origin server bypassing Squid then this needs
5929# to be done in the client configuration. Squid configuration
5930# can only tell Squid how Squid should fetch the object.
5931#
5932# NOTE: This directive is not related to caching. The replies
5933# is cached as usual even if you use always_direct. To not cache
5934# the replies see the 'cache' directive.
5935#
5936# This clause supports both fast and slow acl types.
5937# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5938#Default:
5939# Prevent any cache_peer being used for this request.
5940
5941# TAG: never_direct
5942# Usage: never_direct allow|deny [!]aclname ...
5943#
5944# never_direct is the opposite of always_direct. Please read
5945# the description for always_direct if you have not already.
5946#
5947# With 'never_direct' you can use ACL elements to specify
5948# requests which should NEVER be forwarded directly to origin
5949# servers. For example, to force the use of a proxy for all
5950# requests, except those in your local domain use something like:
5951#
5952# acl local-servers dstdomain .foo.net
5953# never_direct deny local-servers
5954# never_direct allow all
5955#
5956# or if Squid is inside a firewall and there are local intranet
5957# servers inside the firewall use something like:
5958#
5959# acl local-intranet dstdomain .foo.net
5960# acl local-external dstdomain external.foo.net
5961# always_direct deny local-external
5962# always_direct allow local-intranet
5963# never_direct allow all
5964#
5965# This clause supports both fast and slow acl types.
5966# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5967#Default:
5968# Allow DNS results to be used for this request.
5969
5970# ADVANCED NETWORKING OPTIONS
5971# -----------------------------------------------------------------------------
5972
5973# TAG: incoming_udp_average
5974# Heavy voodoo here. I can't even believe you are reading this.
5975# Are you crazy? Don't even think about adjusting these unless
5976# you understand the algorithms in comm_select.c first!
5977#Default:
5978# incoming_udp_average 6
5979
5980# TAG: incoming_tcp_average
5981# Heavy voodoo here. I can't even believe you are reading this.
5982# Are you crazy? Don't even think about adjusting these unless
5983# you understand the algorithms in comm_select.c first!
5984#Default:
5985# incoming_tcp_average 4
5986
5987# TAG: incoming_dns_average
5988# Heavy voodoo here. I can't even believe you are reading this.
5989# Are you crazy? Don't even think about adjusting these unless
5990# you understand the algorithms in comm_select.c first!
5991#Default:
5992# incoming_dns_average 4
5993
5994# TAG: min_udp_poll_cnt
5995# Heavy voodoo here. I can't even believe you are reading this.
5996# Are you crazy? Don't even think about adjusting these unless
5997# you understand the algorithms in comm_select.c first!
5998#Default:
5999# min_udp_poll_cnt 8
6000
6001# TAG: min_dns_poll_cnt
6002# Heavy voodoo here. I can't even believe you are reading this.
6003# Are you crazy? Don't even think about adjusting these unless
6004# you understand the algorithms in comm_select.c first!
6005#Default:
6006# min_dns_poll_cnt 8
6007
6008# TAG: min_tcp_poll_cnt
6009# Heavy voodoo here. I can't even believe you are reading this.
6010# Are you crazy? Don't even think about adjusting these unless
6011# you understand the algorithms in comm_select.c first!
6012#Default:
6013# min_tcp_poll_cnt 8
6014
6015# TAG: accept_filter
6016# FreeBSD:
6017#
6018# The name of an accept(2) filter to install on Squid's
6019# listen socket(s). This feature is perhaps specific to
6020# FreeBSD and requires support in the kernel.
6021#
6022# The 'httpready' filter delays delivering new connections
6023# to Squid until a full HTTP request has been received.
6024# See the accf_http(9) man page for details.
6025#
6026# The 'dataready' filter delays delivering new connections
6027# to Squid until there is some data to process.
6028# See the accf_dataready(9) man page for details.
6029#
6030# Linux:
6031#
6032# The 'data' filter delays delivering of new connections
6033# to Squid until there is some data to process by TCP_ACCEPT_DEFER.
6034# You may optionally specify a number of seconds to wait by
6035# 'data=N' where N is the number of seconds. Defaults to 30
6036# if not specified. See the tcp(7) man page for details.
6037#EXAMPLE:
6038## FreeBSD
6039#accept_filter httpready
6040## Linux
6041#accept_filter data
6042#Default:
6043# none
6044
6045# TAG: client_ip_max_connections
6046# Set an absolute limit on the number of connections a single
6047# client IP can use. Any more than this and Squid will begin to drop
6048# new connections from the client until it closes some links.
6049#
6050# Note that this is a global limit. It affects all HTTP, HTCP, Gopher and FTP
6051# connections from the client. For finer control use the ACL access controls.
6052#
6053# Requires client_db to be enabled (the default).
6054#
6055# WARNING: This may noticably slow down traffic received via external proxies
6056# or NAT devices and cause them to rebound error messages back to their clients.
6057#Default:
6058# No limit.
6059
6060# TAG: tcp_recv_bufsize (bytes)
6061# Size of receive buffer to set for TCP sockets. Probably just
6062# as easy to change your kernel's default.
6063# Omit from squid.conf to use the default buffer size.
6064#Default:
6065# Use operating system TCP defaults.
6066
6067# ICAP OPTIONS
6068# -----------------------------------------------------------------------------
6069
6070# TAG: icap_enable on|off
6071# If you want to enable the ICAP module support, set this to on.
6072#Default:
6073# icap_enable off
6074
6075# TAG: icap_connect_timeout
6076# This parameter specifies how long to wait for the TCP connect to
6077# the requested ICAP server to complete before giving up and either
6078# terminating the HTTP transaction or bypassing the failure.
6079#
6080# The default for optional services is peer_connect_timeout.
6081# The default for essential services is connect_timeout.
6082# If this option is explicitly set, its value applies to all services.
6083#Default:
6084# none
6085
6086# TAG: icap_io_timeout time-units
6087# This parameter specifies how long to wait for an I/O activity on
6088# an established, active ICAP connection before giving up and
6089# either terminating the HTTP transaction or bypassing the
6090# failure.
6091#Default:
6092# Use read_timeout.
6093
6094# TAG: icap_service_failure_limit limit [in memory-depth time-units]
6095# The limit specifies the number of failures that Squid tolerates
6096# when establishing a new TCP connection with an ICAP service. If
6097# the number of failures exceeds the limit, the ICAP service is
6098# not used for new ICAP requests until it is time to refresh its
6099# OPTIONS.
6100#
6101# A negative value disables the limit. Without the limit, an ICAP
6102# service will not be considered down due to connectivity failures
6103# between ICAP OPTIONS requests.
6104#
6105# Squid forgets ICAP service failures older than the specified
6106# value of memory-depth. The memory fading algorithm
6107# is approximate because Squid does not remember individual
6108# errors but groups them instead, splitting the option
6109# value into ten time slots of equal length.
6110#
6111# When memory-depth is 0 and by default this option has no
6112# effect on service failure expiration.
6113#
6114# Squid always forgets failures when updating service settings
6115# using an ICAP OPTIONS transaction, regardless of this option
6116# setting.
6117#
6118# For example,
6119# # suspend service usage after 10 failures in 5 seconds:
6120# icap_service_failure_limit 10 in 5 seconds
6121#Default:
6122# icap_service_failure_limit 10
6123
6124# TAG: icap_service_revival_delay
6125# The delay specifies the number of seconds to wait after an ICAP
6126# OPTIONS request failure before requesting the options again. The
6127# failed ICAP service is considered "down" until fresh OPTIONS are
6128# fetched.
6129#
6130# The actual delay cannot be smaller than the hardcoded minimum
6131# delay of 30 seconds.
6132#Default:
6133# icap_service_revival_delay 180
6134
6135# TAG: icap_preview_enable on|off
6136# The ICAP Preview feature allows the ICAP server to handle the
6137# HTTP message by looking only at the beginning of the message body
6138# or even without receiving the body at all. In some environments,
6139# previews greatly speedup ICAP processing.
6140#
6141# During an ICAP OPTIONS transaction, the server may tell Squid what
6142# HTTP messages should be previewed and how big the preview should be.
6143# Squid will not use Preview if the server did not request one.
6144#
6145# To disable ICAP Preview for all ICAP services, regardless of
6146# individual ICAP server OPTIONS responses, set this option to "off".
6147#Example:
6148#icap_preview_enable off
6149#Default:
6150# icap_preview_enable on
6151
6152# TAG: icap_preview_size
6153# The default size of preview data to be sent to the ICAP server.
6154# This value might be overwritten on a per server basis by OPTIONS requests.
6155#Default:
6156# No preview sent.
6157
6158# TAG: icap_206_enable on|off
6159# 206 (Partial Content) responses is an ICAP extension that allows the
6160# ICAP agents to optionally combine adapted and original HTTP message
6161# content. The decision to combine is postponed until the end of the
6162# ICAP response. Squid supports Partial Content extension by default.
6163#
6164# Activation of the Partial Content extension is negotiated with each
6165# ICAP service during OPTIONS exchange. Most ICAP servers should handle
6166# negotation correctly even if they do not support the extension, but
6167# some might fail. To disable Partial Content support for all ICAP
6168# services and to avoid any negotiation, set this option to "off".
6169#
6170# Example:
6171# icap_206_enable off
6172#Default:
6173# icap_206_enable on
6174
6175# TAG: icap_default_options_ttl
6176# The default TTL value for ICAP OPTIONS responses that don't have
6177# an Options-TTL header.
6178#Default:
6179# icap_default_options_ttl 60
6180
6181# TAG: icap_persistent_connections on|off
6182# Whether or not Squid should use persistent connections to
6183# an ICAP server.
6184#Default:
6185# icap_persistent_connections on
6186
6187# TAG: adaptation_send_client_ip on|off
6188# If enabled, Squid shares HTTP client IP information with adaptation
6189# services. For ICAP, Squid adds the X-Client-IP header to ICAP requests.
6190# For eCAP, Squid sets the libecap::metaClientIp transaction option.
6191#
6192# See also: adaptation_uses_indirect_client
6193#Default:
6194# adaptation_send_client_ip off
6195
6196# TAG: adaptation_send_username on|off
6197# This sends authenticated HTTP client username (if available) to
6198# the adaptation service.
6199#
6200# For ICAP, the username value is encoded based on the
6201# icap_client_username_encode option and is sent using the header
6202# specified by the icap_client_username_header option.
6203#Default:
6204# adaptation_send_username off
6205
6206# TAG: icap_client_username_header
6207# ICAP request header name to use for adaptation_send_username.
6208#Default:
6209# icap_client_username_header X-Client-Username
6210
6211# TAG: icap_client_username_encode on|off
6212# Whether to base64 encode the authenticated client username.
6213#Default:
6214# icap_client_username_encode off
6215
6216# TAG: icap_service
6217# Defines a single ICAP service using the following format:
6218#
6219# icap_service id vectoring_point uri [option ...]
6220#
6221# id: ID
6222# an opaque identifier or name which is used to direct traffic to
6223# this specific service. Must be unique among all adaptation
6224# services in squid.conf.
6225#
6226# vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
6227# This specifies at which point of transaction processing the
6228# ICAP service should be activated. *_postcache vectoring points
6229# are not yet supported.
6230#
6231# uri: icap://servername:port/servicepath
6232# ICAP server and service location.
6233#
6234# ICAP does not allow a single service to handle both REQMOD and RESPMOD
6235# transactions. Squid does not enforce that requirement. You can specify
6236# services with the same service_url and different vectoring_points. You
6237# can even specify multiple identical services as long as their
6238# service_names differ.
6239#
6240# To activate a service, use the adaptation_access directive. To group
6241# services, use adaptation_service_chain and adaptation_service_set.
6242#
6243# Service options are separated by white space. ICAP services support
6244# the following name=value options:
6245#
6246# bypass=on|off|1|0
6247# If set to 'on' or '1', the ICAP service is treated as
6248# optional. If the service cannot be reached or malfunctions,
6249# Squid will try to ignore any errors and process the message as
6250# if the service was not enabled. No all ICAP errors can be
6251# bypassed. If set to 0, the ICAP service is treated as
6252# essential and all ICAP errors will result in an error page
6253# returned to the HTTP client.
6254#
6255# Bypass is off by default: services are treated as essential.
6256#
6257# routing=on|off|1|0
6258# If set to 'on' or '1', the ICAP service is allowed to
6259# dynamically change the current message adaptation plan by
6260# returning a chain of services to be used next. The services
6261# are specified using the X-Next-Services ICAP response header
6262# value, formatted as a comma-separated list of service names.
6263# Each named service should be configured in squid.conf. Other
6264# services are ignored. An empty X-Next-Services value results
6265# in an empty plan which ends the current adaptation.
6266#
6267# Dynamic adaptation plan may cross or cover multiple supported
6268# vectoring points in their natural processing order.
6269#
6270# Routing is not allowed by default: the ICAP X-Next-Services
6271# response header is ignored.
6272#
6273# ipv6=on|off
6274# Only has effect on split-stack systems. The default on those systems
6275# is to use IPv4-only connections. When set to 'on' this option will
6276# make Squid use IPv6-only connections to contact this ICAP service.
6277#
6278# on-overload=block|bypass|wait|force
6279# If the service Max-Connections limit has been reached, do
6280# one of the following for each new ICAP transaction:
6281# * block: send an HTTP error response to the client
6282# * bypass: ignore the "over-connected" ICAP service
6283# * wait: wait (in a FIFO queue) for an ICAP connection slot
6284# * force: proceed, ignoring the Max-Connections limit
6285#
6286# In SMP mode with N workers, each worker assumes the service
6287# connection limit is Max-Connections/N, even though not all
6288# workers may use a given service.
6289#
6290# The default value is "bypass" if service is bypassable,
6291# otherwise it is set to "wait".
6292#
6293#
6294# max-conn=number
6295# Use the given number as the Max-Connections limit, regardless
6296# of the Max-Connections value given by the service, if any.
6297#
6298# Older icap_service format without optional named parameters is
6299# deprecated but supported for backward compatibility.
6300#
6301#Example:
6302#icap_service svcBlocker reqmod_precache icap://icap1.mydomain.net:1344/reqmod bypass=0
6303#icap_service svcLogger reqmod_precache icap://icap2.mydomain.net:1344/respmod routing=on
6304#Default:
6305# none
6306
6307# TAG: icap_class
6308# This deprecated option was documented to define an ICAP service
6309# chain, even though it actually defined a set of similar, redundant
6310# services, and the chains were not supported.
6311#
6312# To define a set of redundant services, please use the
6313# adaptation_service_set directive. For service chains, use
6314# adaptation_service_chain.
6315#Default:
6316# none
6317
6318# TAG: icap_access
6319# This option is deprecated. Please use adaptation_access, which
6320# has the same ICAP functionality, but comes with better
6321# documentation, and eCAP support.
6322#Default:
6323# none
6324
6325# eCAP OPTIONS
6326# -----------------------------------------------------------------------------
6327
6328# TAG: ecap_enable on|off
6329# Controls whether eCAP support is enabled.
6330#Default:
6331# ecap_enable off
6332
6333# TAG: ecap_service
6334# Defines a single eCAP service
6335#
6336# ecap_service id vectoring_point uri [option ...]
6337#
6338# id: ID
6339# an opaque identifier or name which is used to direct traffic to
6340# this specific service. Must be unique among all adaptation
6341# services in squid.conf.
6342#
6343# vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
6344# This specifies at which point of transaction processing the
6345# eCAP service should be activated. *_postcache vectoring points
6346# are not yet supported.
6347#
6348# uri: ecap://vendor/service_name?custom&cgi=style¶meters=optional
6349# Squid uses the eCAP service URI to match this configuration
6350# line with one of the dynamically loaded services. Each loaded
6351# eCAP service must have a unique URI. Obtain the right URI from
6352# the service provider.
6353#
6354# To activate a service, use the adaptation_access directive. To group
6355# services, use adaptation_service_chain and adaptation_service_set.
6356#
6357# Service options are separated by white space. eCAP services support
6358# the following name=value options:
6359#
6360# bypass=on|off|1|0
6361# If set to 'on' or '1', the eCAP service is treated as optional.
6362# If the service cannot be reached or malfunctions, Squid will try
6363# to ignore any errors and process the message as if the service
6364# was not enabled. No all eCAP errors can be bypassed.
6365# If set to 'off' or '0', the eCAP service is treated as essential
6366# and all eCAP errors will result in an error page returned to the
6367# HTTP client.
6368#
6369# Bypass is off by default: services are treated as essential.
6370#
6371# routing=on|off|1|0
6372# If set to 'on' or '1', the eCAP service is allowed to
6373# dynamically change the current message adaptation plan by
6374# returning a chain of services to be used next.
6375#
6376# Dynamic adaptation plan may cross or cover multiple supported
6377# vectoring points in their natural processing order.
6378#
6379# Routing is not allowed by default.
6380#
6381# Older ecap_service format without optional named parameters is
6382# deprecated but supported for backward compatibility.
6383#
6384#
6385#Example:
6386#ecap_service s1 reqmod_precache ecap://filters.R.us/leakDetector?on_error=block bypass=off
6387#ecap_service s2 respmod_precache ecap://filters.R.us/virusFilter config=/etc/vf.cfg bypass=on
6388#Default:
6389# none
6390
6391# TAG: loadable_modules
6392# Instructs Squid to load the specified dynamic module(s) or activate
6393# preloaded module(s).
6394#Example:
6395#loadable_modules /usr/lib/MinimalAdapter.so
6396#Default:
6397# none
6398
6399# MESSAGE ADAPTATION OPTIONS
6400# -----------------------------------------------------------------------------
6401
6402# TAG: adaptation_service_set
6403#
6404# Configures an ordered set of similar, redundant services. This is
6405# useful when hot standby or backup adaptation servers are available.
6406#
6407# adaptation_service_set set_name service_name1 service_name2 ...
6408#
6409# The named services are used in the set declaration order. The first
6410# applicable adaptation service from the set is used first. The next
6411# applicable service is tried if and only if the transaction with the
6412# previous service fails and the message waiting to be adapted is still
6413# intact.
6414#
6415# When adaptation starts, broken services are ignored as if they were
6416# not a part of the set. A broken service is a down optional service.
6417#
6418# The services in a set must be attached to the same vectoring point
6419# (e.g., pre-cache) and use the same adaptation method (e.g., REQMOD).
6420#
6421# If all services in a set are optional then adaptation failures are
6422# bypassable. If all services in the set are essential, then a
6423# transaction failure with one service may still be retried using
6424# another service from the set, but when all services fail, the master
6425# transaction fails as well.
6426#
6427# A set may contain a mix of optional and essential services, but that
6428# is likely to lead to surprising results because broken services become
6429# ignored (see above), making previously bypassable failures fatal.
6430# Technically, it is the bypassability of the last failed service that
6431# matters.
6432#
6433# See also: adaptation_access adaptation_service_chain
6434#
6435#Example:
6436#adaptation_service_set svcBlocker urlFilterPrimary urlFilterBackup
6437#adaptation service_set svcLogger loggerLocal loggerRemote
6438#Default:
6439# none
6440
6441# TAG: adaptation_service_chain
6442#
6443# Configures a list of complementary services that will be applied
6444# one-by-one, forming an adaptation chain or pipeline. This is useful
6445# when Squid must perform different adaptations on the same message.
6446#
6447# adaptation_service_chain chain_name service_name1 svc_name2 ...
6448#
6449# The named services are used in the chain declaration order. The first
6450# applicable adaptation service from the chain is used first. The next
6451# applicable service is applied to the successful adaptation results of
6452# the previous service in the chain.
6453#
6454# When adaptation starts, broken services are ignored as if they were
6455# not a part of the chain. A broken service is a down optional service.
6456#
6457# Request satisfaction terminates the adaptation chain because Squid
6458# does not currently allow declaration of RESPMOD services at the
6459# "reqmod_precache" vectoring point (see icap_service or ecap_service).
6460#
6461# The services in a chain must be attached to the same vectoring point
6462# (e.g., pre-cache) and use the same adaptation method (e.g., REQMOD).
6463#
6464# A chain may contain a mix of optional and essential services. If an
6465# essential adaptation fails (or the failure cannot be bypassed for
6466# other reasons), the master transaction fails. Otherwise, the failure
6467# is bypassed as if the failed adaptation service was not in the chain.
6468#
6469# See also: adaptation_access adaptation_service_set
6470#
6471#Example:
6472#adaptation_service_chain svcRequest requestLogger urlFilter leakDetector
6473#Default:
6474# none
6475
6476# TAG: adaptation_access
6477# Sends an HTTP transaction to an ICAP or eCAP adaptation service.
6478#
6479# adaptation_access service_name allow|deny [!]aclname...
6480# adaptation_access set_name allow|deny [!]aclname...
6481#
6482# At each supported vectoring point, the adaptation_access
6483# statements are processed in the order they appear in this
6484# configuration file. Statements pointing to the following services
6485# are ignored (i.e., skipped without checking their ACL):
6486#
6487# - services serving different vectoring points
6488# - "broken-but-bypassable" services
6489# - "up" services configured to ignore such transactions
6490# (e.g., based on the ICAP Transfer-Ignore header).
6491#
6492# When a set_name is used, all services in the set are checked
6493# using the same rules, to find the first applicable one. See
6494# adaptation_service_set for details.
6495#
6496# If an access list is checked and there is a match, the
6497# processing stops: For an "allow" rule, the corresponding
6498# adaptation service is used for the transaction. For a "deny"
6499# rule, no adaptation service is activated.
6500#
6501# It is currently not possible to apply more than one adaptation
6502# service at the same vectoring point to the same HTTP transaction.
6503#
6504# See also: icap_service and ecap_service
6505#
6506#Example:
6507#adaptation_access service_1 allow all
6508#Default:
6509# Allow, unless rules exist in squid.conf.
6510
6511# TAG: adaptation_service_iteration_limit
6512# Limits the number of iterations allowed when applying adaptation
6513# services to a message. If your longest adaptation set or chain
6514# may have more than 16 services, increase the limit beyond its
6515# default value of 16. If detecting infinite iteration loops sooner
6516# is critical, make the iteration limit match the actual number
6517# of services in your longest adaptation set or chain.
6518#
6519# Infinite adaptation loops are most likely with routing services.
6520#
6521# See also: icap_service routing=1
6522#Default:
6523# adaptation_service_iteration_limit 16
6524
6525# TAG: adaptation_masterx_shared_names
6526# For each master transaction (i.e., the HTTP request and response
6527# sequence, including all related ICAP and eCAP exchanges), Squid
6528# maintains a table of metadata. The table entries are (name, value)
6529# pairs shared among eCAP and ICAP exchanges. The table is destroyed
6530# with the master transaction.
6531#
6532# This option specifies the table entry names that Squid must accept
6533# from and forward to the adaptation transactions.
6534#
6535# An ICAP REQMOD or RESPMOD transaction may set an entry in the
6536# shared table by returning an ICAP header field with a name
6537# specified in adaptation_masterx_shared_names.
6538#
6539# An eCAP REQMOD or RESPMOD transaction may set an entry in the
6540# shared table by implementing the libecap::visitEachOption() API
6541# to provide an option with a name specified in
6542# adaptation_masterx_shared_names.
6543#
6544# Squid will store and forward the set entry to subsequent adaptation
6545# transactions within the same master transaction scope.
6546#
6547# Only one shared entry name is supported at this time.
6548#
6549#Example:
6550## share authentication information among ICAP services
6551#adaptation_masterx_shared_names X-Subscriber-ID
6552#Default:
6553# none
6554
6555# TAG: adaptation_meta
6556# This option allows Squid administrator to add custom ICAP request
6557# headers or eCAP options to Squid ICAP requests or eCAP transactions.
6558# Use it to pass custom authentication tokens and other
6559# transaction-state related meta information to an ICAP/eCAP service.
6560#
6561# The addition of a meta header is ACL-driven:
6562# adaptation_meta name value [!]aclname ...
6563#
6564# Processing for a given header name stops after the first ACL list match.
6565# Thus, it is impossible to add two headers with the same name. If no ACL
6566# lists match for a given header name, no such header is added. For
6567# example:
6568#
6569# # do not debug transactions except for those that need debugging
6570# adaptation_meta X-Debug 1 needs_debugging
6571#
6572# # log all transactions except for those that must remain secret
6573# adaptation_meta X-Log 1 !keep_secret
6574#
6575# # mark transactions from users in the "G 1" group
6576# adaptation_meta X-Authenticated-Groups "G 1" authed_as_G1
6577#
6578# The "value" parameter may be a regular squid.conf token or a "double
6579# quoted string". Within the quoted string, use backslash (\) to escape
6580# any character, which is currently only useful for escaping backslashes
6581# and double quotes. For example,
6582# "this string has one backslash (\\) and two \"quotes\""
6583#Default:
6584# none
6585
6586# TAG: icap_retry
6587# This ACL determines which retriable ICAP transactions are
6588# retried. Transactions that received a complete ICAP response
6589# and did not have to consume or produce HTTP bodies to receive
6590# that response are usually retriable.
6591#
6592# icap_retry allow|deny [!]aclname ...
6593#
6594# Squid automatically retries some ICAP I/O timeouts and errors
6595# due to persistent connection race conditions.
6596#
6597# See also: icap_retry_limit
6598#Default:
6599# icap_retry deny all
6600
6601# TAG: icap_retry_limit
6602# Limits the number of retries allowed.
6603#
6604# Communication errors due to persistent connection race
6605# conditions are unavoidable, automatically retried, and do not
6606# count against this limit.
6607#
6608# See also: icap_retry
6609#Default:
6610# No retries are allowed.
6611
6612# DNS OPTIONS
6613# -----------------------------------------------------------------------------
6614
6615# TAG: check_hostnames
6616# For security and stability reasons Squid can check
6617# hostnames for Internet standard RFC compliance. If you want
6618# Squid to perform these checks turn this directive on.
6619#Default:
6620# check_hostnames off
6621
6622# TAG: allow_underscore
6623# Underscore characters is not strictly allowed in Internet hostnames
6624# but nevertheless used by many sites. Set this to off if you want
6625# Squid to be strict about the standard.
6626# This check is performed only when check_hostnames is set to on.
6627#Default:
6628# allow_underscore on
6629
6630# TAG: cache_dns_program
6631# Note: This option is only available if Squid is rebuilt with the
6632# --disable-internal-dns
6633#
6634# Specify the location of the executable for dnslookup process.
6635#Default:
6636# cache_dns_program /usr/lib/squid3/dnsserver
6637
6638# TAG: dns_children
6639# Note: This option is only available if Squid is rebuilt with the
6640# --disable-internal-dns
6641#
6642# The maximum number of processes spawn to service DNS name lookups.
6643# If you limit it too few Squid will have to wait for them to process
6644# a backlog of requests, slowing it down. If you allow too many they
6645# will use RAM and other system resources noticably.
6646# The maximum this may be safely set to is 32.
6647#
6648# The startup= and idle= options allow some measure of skew in your
6649# tuning.
6650#
6651# startup=
6652#
6653# Sets a minimum of how many processes are to be spawned when Squid
6654# starts or reconfigures. When set to zero the first request will
6655# cause spawning of the first child process to handle it.
6656#
6657# Starting too few will cause an initial slowdown in traffic as Squid
6658# attempts to simultaneously spawn enough processes to cope.
6659#
6660# idle=
6661#
6662# Sets a minimum of how many processes Squid is to try and keep available
6663# at all times. When traffic begins to rise above what the existing
6664# processes can handle this many more will be spawned up to the maximum
6665# configured. A minimum setting of 1 is required.
6666#Default:
6667# dns_children 32 startup=1 idle=1
6668
6669# TAG: dns_retransmit_interval
6670# Initial retransmit interval for DNS queries. The interval is
6671# doubled each time all configured DNS servers have been tried.
6672#Default:
6673# dns_retransmit_interval 5 seconds
6674
6675# TAG: dns_timeout
6676# DNS Query timeout. If no response is received to a DNS query
6677# within this time all DNS servers for the queried domain
6678# are assumed to be unavailable.
6679#Default:
6680# dns_timeout 30 seconds
6681
6682# TAG: dns_packet_max
6683# Maximum number of bytes packet size to advertise via EDNS.
6684# Set to "none" to disable EDNS large packet support.
6685#
6686# For legacy reasons DNS UDP replies will default to 512 bytes which
6687# is too small for many responses. EDNS provides a means for Squid to
6688# negotiate receiving larger responses back immediately without having
6689# to failover with repeat requests. Responses larger than this limit
6690# will retain the old behaviour of failover to TCP DNS.
6691#
6692# Squid has no real fixed limit internally, but allowing packet sizes
6693# over 1500 bytes requires network jumbogram support and is usually not
6694# necessary.
6695#
6696# WARNING: The RFC also indicates that some older resolvers will reply
6697# with failure of the whole request if the extension is added. Some
6698# resolvers have already been identified which will reply with mangled
6699# EDNS response on occasion. Usually in response to many-KB jumbogram
6700# sizes being advertised by Squid.
6701# Squid will currently treat these both as an unable-to-resolve domain
6702# even if it would be resolvable without EDNS.
6703#Default:
6704# EDNS disabled
6705
6706# TAG: dns_defnames on|off
6707# Normally the RES_DEFNAMES resolver option is disabled
6708# (see res_init(3)). This prevents caches in a hierarchy
6709# from interpreting single-component hostnames locally. To allow
6710# Squid to handle single-component names, enable this option.
6711#Default:
6712# Search for single-label domain names is disabled.
6713
6714# TAG: dns_nameservers
6715# Use this if you want to specify a list of DNS name servers
6716# (IP addresses) to use instead of those given in your
6717# /etc/resolv.conf file.
6718#
6719# On Windows platforms, if no value is specified here or in
6720# the /etc/resolv.conf file, the list of DNS name servers are
6721# taken from the Windows registry, both static and dynamic DHCP
6722# configurations are supported.
6723#
6724# Example: dns_nameservers 10.0.0.1 192.172.0.4
6725#Default:
6726# Use operating system definitions
6727
6728# TAG: hosts_file
6729# Location of the host-local IP name-address associations
6730# database. Most Operating Systems have such a file on different
6731# default locations:
6732# - Un*X & Linux: /etc/hosts
6733# - Windows NT/2000: %SystemRoot%\system32\drivers\etc\hosts
6734# (%SystemRoot% value install default is c:\winnt)
6735# - Windows XP/2003: %SystemRoot%\system32\drivers\etc\hosts
6736# (%SystemRoot% value install default is c:\windows)
6737# - Windows 9x/Me: %windir%\hosts
6738# (%windir% value is usually c:\windows)
6739# - Cygwin: /etc/hosts
6740#
6741# The file contains newline-separated definitions, in the
6742# form ip_address_in_dotted_form name [name ...] names are
6743# whitespace-separated. Lines beginning with an hash (#)
6744# character are comments.
6745#
6746# The file is checked at startup and upon configuration.
6747# If set to 'none', it won't be checked.
6748# If append_domain is used, that domain will be added to
6749# domain-local (i.e. not containing any dot character) host
6750# definitions.
6751#Default:
6752# hosts_file /etc/hosts
6753
6754# TAG: append_domain
6755# Appends local domain name to hostnames without any dots in
6756# them. append_domain must begin with a period.
6757#
6758# Be warned there are now Internet names with no dots in
6759# them using only top-domain names, so setting this may
6760# cause some Internet sites to become unavailable.
6761#
6762#Example:
6763# append_domain .yourdomain.com
6764#Default:
6765# Use operating system definitions
6766
6767# TAG: ignore_unknown_nameservers
6768# By default Squid checks that DNS responses are received
6769# from the same IP addresses they are sent to. If they
6770# don't match, Squid ignores the response and writes a warning
6771# message to cache.log. You can allow responses from unknown
6772# nameservers by setting this option to 'off'.
6773#Default:
6774# ignore_unknown_nameservers on
6775
6776# TAG: dns_v4_first
6777# With the IPv6 Internet being as fast or faster than IPv4 Internet
6778# for most networks Squid prefers to contact websites over IPv6.
6779#
6780# This option reverses the order of preference to make Squid contact
6781# dual-stack websites over IPv4 first. Squid will still perform both
6782# IPv6 and IPv4 DNS lookups before connecting.
6783#
6784# WARNING:
6785# This option will restrict the situations under which IPv6
6786# connectivity is used (and tested), potentially hiding network
6787# problems which would otherwise be detected and warned about.
6788#Default:
6789# dns_v4_first off
6790
6791# TAG: ipcache_size (number of entries)
6792# Maximum number of DNS IP cache entries.
6793#Default:
6794# ipcache_size 1024
6795
6796# TAG: ipcache_low (percent)
6797#Default:
6798# ipcache_low 90
6799
6800# TAG: ipcache_high (percent)
6801# The size, low-, and high-water marks for the IP cache.
6802#Default:
6803# ipcache_high 95
6804
6805# TAG: fqdncache_size (number of entries)
6806# Maximum number of FQDN cache entries.
6807#Default:
6808# fqdncache_size 1024
6809
6810# MISCELLANEOUS
6811# -----------------------------------------------------------------------------
6812
6813# TAG: memory_pools on|off
6814# If set, Squid will keep pools of allocated (but unused) memory
6815# available for future use. If memory is a premium on your
6816# system and you believe your malloc library outperforms Squid
6817# routines, disable this.
6818#Default:
6819# memory_pools on
6820
6821# TAG: memory_pools_limit (bytes)
6822# Used only with memory_pools on:
6823# memory_pools_limit 50 MB
6824#
6825# If set to a non-zero value, Squid will keep at most the specified
6826# limit of allocated (but unused) memory in memory pools. All free()
6827# requests that exceed this limit will be handled by your malloc
6828# library. Squid does not pre-allocate any memory, just safe-keeps
6829# objects that otherwise would be free()d. Thus, it is safe to set
6830# memory_pools_limit to a reasonably high value even if your
6831# configuration will use less memory.
6832#
6833# If set to none, Squid will keep all memory it can. That is, there
6834# will be no limit on the total amount of memory used for safe-keeping.
6835#
6836# To disable memory allocation optimization, do not set
6837# memory_pools_limit to 0 or none. Set memory_pools to "off" instead.
6838#
6839# An overhead for maintaining memory pools is not taken into account
6840# when the limit is checked. This overhead is close to four bytes per
6841# object kept. However, pools may actually _save_ memory because of
6842# reduced memory thrashing in your malloc library.
6843#Default:
6844# memory_pools_limit 5 MB
6845
6846# TAG: forwarded_for on|off|transparent|truncate|delete
6847# If set to "on", Squid will append your client's IP address
6848# in the HTTP requests it forwards. By default it looks like:
6849#
6850# X-Forwarded-For: 192.1.2.3
6851#
6852# If set to "off", it will appear as
6853#
6854# X-Forwarded-For: unknown
6855#
6856# If set to "transparent", Squid will not alter the
6857# X-Forwarded-For header in any way.
6858#
6859# If set to "delete", Squid will delete the entire
6860# X-Forwarded-For header.
6861#
6862# If set to "truncate", Squid will remove all existing
6863# X-Forwarded-For entries, and place the client IP as the sole entry.
6864#Default:
6865# forwarded_for on
6866
6867# TAG: cachemgr_passwd
6868# Specify passwords for cachemgr operations.
6869#
6870# Usage: cachemgr_passwd password action action ...
6871#
6872# Some valid actions are (see cache manager menu for a full list):
6873# 5min
6874# 60min
6875# asndb
6876# authenticator
6877# cbdata
6878# client_list
6879# comm_incoming
6880# config *
6881# counters
6882# delay
6883# digest_stats
6884# dns
6885# events
6886# filedescriptors
6887# fqdncache
6888# histograms
6889# http_headers
6890# info
6891# io
6892# ipcache
6893# mem
6894# menu
6895# netdb
6896# non_peers
6897# objects
6898# offline_toggle *
6899# pconn
6900# peer_select
6901# reconfigure *
6902# redirector
6903# refresh
6904# server_list
6905# shutdown *
6906# store_digest
6907# storedir
6908# utilization
6909# via_headers
6910# vm_objects
6911#
6912# * Indicates actions which will not be performed without a
6913# valid password, others can be performed if not listed here.
6914#
6915# To disable an action, set the password to "disable".
6916# To allow performing an action without a password, set the
6917# password to "none".
6918#
6919# Use the keyword "all" to set the same password for all actions.
6920#
6921#Example:
6922# cachemgr_passwd secret shutdown
6923# cachemgr_passwd lesssssssecret info stats/objects
6924# cachemgr_passwd disable all
6925#Default:
6926# No password. Actions which require password are denied.
6927
6928# TAG: client_db on|off
6929# If you want to disable collecting per-client statistics,
6930# turn off client_db here.
6931#Default:
6932# client_db on
6933
6934# TAG: refresh_all_ims on|off
6935# When you enable this option, squid will always check
6936# the origin server for an update when a client sends an
6937# If-Modified-Since request. Many browsers use IMS
6938# requests when the user requests a reload, and this
6939# ensures those clients receive the latest version.
6940#
6941# By default (off), squid may return a Not Modified response
6942# based on the age of the cached version.
6943#Default:
6944# refresh_all_ims off
6945
6946# TAG: reload_into_ims on|off
6947# When you enable this option, client no-cache or ``reload''
6948# requests will be changed to If-Modified-Since requests.
6949# Doing this VIOLATES the HTTP standard. Enabling this
6950# feature could make you liable for problems which it
6951# causes.
6952#
6953# see also refresh_pattern for a more selective approach.
6954#Default:
6955# reload_into_ims off
6956
6957# TAG: connect_retries
6958# This sets the maximum number of connection attempts made for each
6959# TCP connection. The connect_retries attempts must all still
6960# complete within the connection timeout period.
6961#
6962# The default is not to re-try if the first connection attempt fails.
6963# The (not recommended) maximum is 10 tries.
6964#
6965# A warning message will be generated if it is set to a too-high
6966# value and the configured value will be over-ridden.
6967#
6968# Note: These re-tries are in addition to forward_max_tries
6969# which limit how many different addresses may be tried to find
6970# a useful server.
6971#Default:
6972# Do not retry failed connections.
6973
6974# TAG: retry_on_error
6975# If set to ON Squid will automatically retry requests when
6976# receiving an error response with status 403 (Forbidden),
6977# 500 (Internal Error), 501 or 503 (Service not available).
6978# Status 502 and 504 (Gateway errors) are always retried.
6979#
6980# This is mainly useful if you are in a complex cache hierarchy to
6981# work around access control errors.
6982#
6983# NOTE: This retry will attempt to find another working destination.
6984# Which is different from the server which just failed.
6985#Default:
6986# retry_on_error off
6987
6988# TAG: as_whois_server
6989# WHOIS server to query for AS numbers. NOTE: AS numbers are
6990# queried only when Squid starts up, not for every request.
6991#Default:
6992# as_whois_server whois.ra.net
6993
6994# TAG: offline_mode
6995# Enable this option and Squid will never try to validate cached
6996# objects.
6997#Default:
6998# offline_mode off
6999
7000# TAG: uri_whitespace
7001# What to do with requests that have whitespace characters in the
7002# URI. Options:
7003#
7004# strip: The whitespace characters are stripped out of the URL.
7005# This is the behavior recommended by RFC2396 and RFC3986
7006# for tolerant handling of generic URI.
7007# NOTE: This is one difference between generic URI and HTTP URLs.
7008#
7009# deny: The request is denied. The user receives an "Invalid
7010# Request" message.
7011# This is the behaviour recommended by RFC2616 for safe
7012# handling of HTTP request URL.
7013#
7014# allow: The request is allowed and the URI is not changed. The
7015# whitespace characters remain in the URI. Note the
7016# whitespace is passed to redirector processes if they
7017# are in use.
7018# Note this may be considered a violation of RFC2616
7019# request parsing where whitespace is prohibited in the
7020# URL field.
7021#
7022# encode: The request is allowed and the whitespace characters are
7023# encoded according to RFC1738.
7024#
7025# chop: The request is allowed and the URI is chopped at the
7026# first whitespace.
7027#
7028#
7029# NOTE the current Squid implementation of encode and chop violates
7030# RFC2616 by not using a 301 redirect after altering the URL.
7031#Default:
7032# uri_whitespace strip
7033
7034# TAG: chroot
7035# Specifies a directory where Squid should do a chroot() while
7036# initializing. This also causes Squid to fully drop root
7037# privileges after initializing. This means, for example, if you
7038# use a HTTP port less than 1024 and try to reconfigure, you may
7039# get an error saying that Squid can not open the port.
7040#Default:
7041# none
7042
7043# TAG: balance_on_multiple_ip
7044# Modern IP resolvers in squid sort lookup results by preferred access.
7045# By default squid will use these IP in order and only rotates to
7046# the next listed when the most preffered fails.
7047#
7048# Some load balancing servers based on round robin DNS have been
7049# found not to preserve user session state across requests
7050# to different IP addresses.
7051#
7052# Enabling this directive Squid rotates IP's per request.
7053#Default:
7054# balance_on_multiple_ip off
7055
7056# TAG: pipeline_prefetch
7057# To boost the performance of pipelined requests to closer
7058# match that of a non-proxied environment Squid can try to fetch
7059# up to two requests in parallel from a pipeline.
7060#
7061# Defaults to off for bandwidth management and access logging
7062# reasons.
7063#
7064# WARNING: pipelining breaks NTLM and Negotiate/Kerberos authentication.
7065#Default:
7066# pipeline_prefetch off
7067
7068# TAG: high_response_time_warning (msec)
7069# If the one-minute median response time exceeds this value,
7070# Squid prints a WARNING with debug level 0 to get the
7071# administrators attention. The value is in milliseconds.
7072#Default:
7073# disabled.
7074
7075# TAG: high_page_fault_warning
7076# If the one-minute average page fault rate exceeds this
7077# value, Squid prints a WARNING with debug level 0 to get
7078# the administrators attention. The value is in page faults
7079# per second.
7080#Default:
7081# disabled.
7082
7083# TAG: high_memory_warning
7084# If the memory usage (as determined by mallinfo) exceeds
7085# this amount, Squid prints a WARNING with debug level 0 to get
7086# the administrators attention.
7087#Default:
7088# disabled.
7089
7090# TAG: sleep_after_fork (microseconds)
7091# When this is set to a non-zero value, the main Squid process
7092# sleeps the specified number of microseconds after a fork()
7093# system call. This sleep may help the situation where your
7094# system reports fork() failures due to lack of (virtual)
7095# memory. Note, however, if you have a lot of child
7096# processes, these sleep delays will add up and your
7097# Squid will not service requests for some amount of time
7098# until all the child processes have been started.
7099# On Windows value less then 1000 (1 milliseconds) are
7100# rounded to 1000.
7101#Default:
7102# sleep_after_fork 0
7103
7104# TAG: windows_ipaddrchangemonitor on|off
7105# Note: This option is only available if Squid is rebuilt with the
7106# MS Windows
7107#
7108# On Windows Squid by default will monitor IP address changes and will
7109# reconfigure itself after any detected event. This is very useful for
7110# proxies connected to internet with dial-up interfaces.
7111# In some cases (a Proxy server acting as VPN gateway is one) it could be
7112# desiderable to disable this behaviour setting this to 'off'.
7113# Note: after changing this, Squid service must be restarted.
7114#Default:
7115# windows_ipaddrchangemonitor on
7116
7117# TAG: eui_lookup
7118# Whether to lookup the EUI or MAC address of a connected client.
7119#Default:
7120# eui_lookup on
7121
7122# TAG: max_filedescriptors
7123# Reduce the maximum number of filedescriptors supported below
7124# the usual operating system defaults.
7125#
7126# Remove from squid.conf to inherit the current ulimit setting.
7127#
7128# Note: Changing this requires a restart of Squid. Also
7129# not all I/O types supports large values (eg on Windows).
7130#Default:
7131# Use operating system limits set by ulimit.
7132
7133# TAG: workers
7134# Number of main Squid processes or "workers" to fork and maintain.
7135# 0: "no daemon" mode, like running "squid -N ..."
7136# 1: "no SMP" mode, start one main Squid process daemon (default)
7137# N: start N main Squid process daemons (i.e., SMP mode)
7138#
7139# In SMP mode, each worker does nearly all what a single Squid daemon
7140# does (e.g., listen on http_port and forward HTTP requests).
7141#Default:
7142# SMP support disabled.
7143
7144# TAG: cpu_affinity_map
7145# Usage: cpu_affinity_map process_numbers=P1,P2,... cores=C1,C2,...
7146#
7147# Sets 1:1 mapping between Squid processes and CPU cores. For example,
7148#
7149# cpu_affinity_map process_numbers=1,2,3,4 cores=1,3,5,7
7150#
7151# affects processes 1 through 4 only and places them on the first
7152# four even cores, starting with core #1.
7153#
7154# CPU cores are numbered starting from 1. Requires support for
7155# sched_getaffinity(2) and sched_setaffinity(2) system calls.
7156#
7157# Multiple cpu_affinity_map options are merged.
7158#
7159# See also: workers
7160#Default:
7161# Let operating system decide.