2 # SQUID Web Proxy Cache http://www.squid-cache.org/
3 # ----------------------------------------------------------
5 # Squid is the result of efforts by numerous individuals from
6 # the Internet community; see the CONTRIBUTORS file for full
7 # details. Many organizations have provided support for Squid's
8 # development; see the SPONSORS file for full details. Squid is
9 # Copyrighted (C) 2000 by the Regents of the University of
10 # California; see the COPYRIGHT file for full details. Squid
11 # incorporates software developed and/or copyrighted by other
12 # sources; see the CREDITS file for full details.
14 # This program is free software; you can redistribute it and/or modify
15 # it under the terms of the GNU General Public License as published by
16 # the Free Software Foundation; either version 2 of the License, or
17 # (at your option) any later version.
19 # This program is distributed in the hope that it will be useful,
20 # but WITHOUT ANY WARRANTY; without even the implied warranty of
21 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 # GNU General Public License for more details.
24 # You should have received a copy of the GNU General Public License
25 # along with this program; if not, write to the Free Software
26 # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
31 ----------------------------
33 This is the documentation for the Squid configuration file.
34 This documentation can also be found online at:
35 http://www.squid-cache.org/Doc/config/
37 You may wish to look at the Squid home page and wiki for the
38 FAQ and other documentation:
39 http://www.squid-cache.org/
40 http://wiki.squid-cache.org/SquidFaq
41 http://wiki.squid-cache.org/ConfigExamples
43 This documentation shows what the defaults for various directives
44 happen to be. If you don't need to change the default, you should
45 leave the line out of your squid.conf in most cases.
47 In some cases "none" refers to no default setting at all,
48 while in other cases it refers to the value of the option
49 - the comments for that keyword indicate if this is the case.
54 Configuration options can be included using the "include" directive.
55 Include takes a list of files to include. Quoting and wildcards are
60 include /path/to/included/file/squid.acl.config
62 Includes can be nested up to a hard-coded depth of 16 levels.
63 This arbitrary restriction is to prevent recursive include references
64 from causing Squid entering an infinite loop whilst trying to load
67 Values with byte units
69 Squid accepts size units on some size related directives. All
70 such directives are documented with a default value displaying
73 Units accepted by Squid are:
75 KB - Kilobyte (1024 bytes)
79 Values with spaces, quotes, and other special characters
81 Squid supports directive parameters with spaces, quotes, and other
82 special characters. Surround such parameters with "double quotes". Use
83 the configuration_includes_quoted_values directive to enable or
86 Squid supports reading configuration option parameters from external
87 files using the syntax:
88 parameters("/path/filename")
90 acl whitelist dstdomain parameters("/etc/squid/whitelist.txt")
92 Conditional configuration
94 If-statements can be used to make configuration directives
98 ... regular configuration directives ...
100 ... regular configuration directives ...]
103 The else part is optional. The keywords "if", "else", and "endif"
104 must be typed on their own lines, as if they were regular
105 configuration directives.
107 NOTE: An else-if condition is not supported.
109 These individual conditions types are supported:
112 Always evaluates to true.
114 Always evaluates to false.
115 <integer> = <integer>
116 Equality comparison of two integer numbers.
121 The following SMP-related preprocessor macros can be used.
123 ${process_name} expands to the current Squid process "name"
124 (e.g., squid1, squid2, or cache1).
126 ${process_number} expands to the current Squid process
127 identifier, which is an integer number (e.g., 1, 2, 3) unique
128 across all Squid processes of the current service instance.
130 ${service_name} expands into the current Squid service instance
131 name identifier which is provided by -n on the command line.
135 # options still not yet ported from 2.7 to 3.x
136 NAME: broken_vary_encoding
139 This option is not yet supported by Squid-3.
145 This option is not yet supported by Squid-3.
151 This option is not yet supported by Squid-3.
154 NAME: external_refresh_check
157 This option is not yet supported by Squid-3.
160 NAME: location_rewrite_program location_rewrite_access location_rewrite_children location_rewrite_concurrency
163 This option is not yet supported by Squid-3.
166 NAME: refresh_stale_hit
169 This option is not yet supported by Squid-3.
172 # Options removed in 3.5
173 NAME: hierarchy_stoplist
176 Remove this line. Use always_direct or cache_peer_access ACLs instead if you need to prevent cache_peer use.
182 Remove this line. Use acls with access_log directives to control access logging
188 Remove this line. Use acls with icap_log directives to control icap logging
191 # Options Removed in 3.3
192 NAME: ignore_ims_on_miss
195 Remove this line. The HTTP/1.1 feature is now configured by 'cache_miss_revalidate'.
198 # Options Removed in 3.2
199 NAME: dns_v4_fallback
202 Remove this line. Squid performs a 'Happy Eyeballs' algorithm, the 'fallback' algorithm is no longer relevant.
205 NAME: emulate_httpd_log
208 Replace this with an access_log directive using the format 'common' or 'combined'.
214 Use a regular access.log with ACL limiting it to MISS events.
220 Remove this line. Configure FTP page display using the CSS controls in errorpages.css instead.
223 NAME: ignore_expect_100
226 Remove this line. The HTTP/1.1 feature is now fully supported by default.
232 Remove this option from your config. To log FQDN use %>A in the log format.
235 NAME: log_ip_on_direct
238 Remove this option from your config. To log server or peer names use %<A in the log format.
241 NAME: maximum_single_addr_tries
244 Replaced by connect_retries. The behaviour has changed, please read the documentation before altering.
247 NAME: referer_log referrer_log
250 Replace this with an access_log directive using the format 'referrer'.
256 Remove this line. The feature is supported by default in storage types where update is implemented.
259 NAME: url_rewrite_concurrency
262 Remove this line. Set the 'concurrency=' option of url_rewrite_children instead.
268 Replace this with an access_log directive using the format 'useragent'.
271 # Options Removed in 3.1
275 Remove this line. DNS is no longer tested on startup.
278 NAME: extension_methods
281 Remove this line. All valid methods for HTTP are accepted by default.
284 # 2.7 Options Removed/Replaced in 3.2
289 # 2.7 Options Removed/Replaced in 3.1
297 Remove this line. HTTP/1.1 is supported by default.
300 NAME: upgrade_http0.9
303 Remove this line. ICY/1.0 streaming protocol is supported by default.
306 NAME: zph_local zph_mode zph_option zph_parent zph_sibling
309 Alter these entries. Use the qos_flows directive instead.
312 # Options Removed in 3.0
316 Since squid-3.0 replace with request_header_access or reply_header_access
317 depending on whether you wish to match client requests or server replies.
320 NAME: httpd_accel_no_pmtu_disc
323 Since squid-3.0 use the 'disable-pmtu-discovery' flag on http_port instead.
326 NAME: wais_relay_host
329 Replace this line with 'cache_peer' configuration.
332 NAME: wais_relay_port
335 Replace this line with 'cache_peer' configuration.
339 OPTIONS FOR AUTHENTICATION
340 -----------------------------------------------------------------------------
349 This is used to define parameters for the various authentication
350 schemes supported by Squid.
352 format: auth_param scheme parameter [setting]
354 The order in which authentication schemes are presented to the client is
355 dependent on the order the scheme first appears in config file. IE
356 has a bug (it's not RFC 2617 compliant) in that it will use the basic
357 scheme if basic is the first entry presented, even if more secure
358 schemes are presented. For now use the order in the recommended
359 settings section below. If other browsers have difficulties (don't
360 recognize the schemes offered even if you are using basic) either
361 put basic first, or disable the other schemes (by commenting out their
364 Once an authentication scheme is fully configured, it can only be
365 shutdown by shutting squid down and restarting. Changes can be made on
366 the fly and activated with a reconfigure. I.E. You can change to a
367 different helper, but not unconfigure the helper completely.
369 Please note that while this directive defines how Squid processes
370 authentication it does not automatically activate authentication.
371 To use authentication you must in addition make use of ACLs based
372 on login name in http_access (proxy_auth, proxy_auth_regex or
373 external with %LOGIN used in the format tag). The browser will be
374 challenged for authentication on the first such acl encountered
375 in http_access processing and will also be re-challenged for new
376 login credentials if the request is being denied by a proxy_auth
379 WARNING: authentication can't be used in a transparently intercepting
380 proxy as the client then thinks it is talking to an origin server and
381 not the proxy. This is a limitation of bending the TCP/IP protocol to
382 transparently intercepting port 80, not a limitation in Squid.
383 Ports flagged 'transparent', 'intercept', or 'tproxy' have
384 authentication disabled.
386 === Parameters common to all schemes. ===
389 Specifies the command for the external authenticator.
391 By default, each authentication scheme is not used unless a
392 program is specified.
394 See http://wiki.squid-cache.org/Features/AddonHelpers for
395 more details on helper operations and creating your own.
398 Specifies a string to be append to request line format for
399 the authentication helper. "Quoted" format values may contain
400 spaces and logformat %macros. In theory, any logformat %macro
401 can be used. In practice, a %macro expands as a dash (-) if
402 the helper request is sent before the required macro
403 information is available to Squid.
405 By default, Squid uses request formats provided in
406 scheme-specific examples below (search for %credentials).
408 The expanded key_extras value is added to the Squid credentials
409 cache and, hence, will affect authentication. It can be used to
410 autenticate different users with identical user names (e.g.,
411 when user authentication depends on http_port).
413 Avoid adding frequently changing information to key_extras. For
414 example, if you add user source IP, and it changes frequently
415 in your environment, then max_user_ip ACL is going to treat
416 every user+IP combination as a unique "user", breaking the ACL
417 and wasting a lot of memory on those user records. It will also
418 force users to authenticate from scratch whenever their IP
422 Specifies the protection scope (aka realm name) which is to be
423 reported to the client for the authentication scheme. It is
424 commonly part of the text the user will see when prompted for
425 their username and password.
427 For Basic the default is "Squid proxy-caching web server".
428 For Digest there is no default, this parameter is mandatory.
429 For NTLM and Negotiate this parameter is ignored.
431 "children" numberofchildren [startup=N] [idle=N] [concurrency=N]
433 The maximum number of authenticator processes to spawn. If
434 you start too few Squid will have to wait for them to process
435 a backlog of credential verifications, slowing it down. When
436 password verifications are done via a (slow) network you are
437 likely to need lots of authenticator processes.
439 The startup= and idle= options permit some skew in the exact
440 amount run. A minimum of startup=N will begin during startup
441 and reconfigure. Squid will start more in groups of up to
442 idle=N in an attempt to meet traffic needs and to keep idle=N
443 free above those traffic needs up to the maximum.
445 The concurrency= option sets the number of concurrent requests
446 the helper can process. The default of 0 is used for helpers
447 who only supports one request at a time. Setting this to a
448 number greater than 0 changes the protocol used to include a
449 channel ID field first on the request/response line, allowing
450 multiple requests to be sent to the same helper in parallel
451 without waiting for the response.
453 Concurrency must not be set unless it's known the helper
454 supports the input format with channel-ID fields.
456 NOTE: NTLM and Negotiate schemes do not support concurrency
457 in the Squid code module even though some helpers can.
460 IF HAVE_AUTH_MODULE_BASIC
461 === Basic authentication parameters ===
464 HTTP uses iso-latin-1 as character set, while some
465 authentication backends such as LDAP expects UTF-8. If this is
466 set to on Squid will translate the HTTP iso-latin-1 charset to
467 UTF-8 before sending the username and password to the helper.
469 "credentialsttl" timetolive
470 Specifies how long squid assumes an externally validated
471 username:password pair is valid for - in other words how
472 often the helper program is called for that user. Set this
473 low to force revalidation with short lived passwords.
475 NOTE: setting this high does not impact your susceptibility
476 to replay attacks unless you are using an one-time password
477 system (such as SecureID). If you are using such a system,
478 you will be vulnerable to replay attacks unless you also
479 use the max_user_ip ACL in an http_access rule.
481 "casesensitive" on|off
482 Specifies if usernames are case sensitive. Most user databases
483 are case insensitive allowing the same username to be spelled
484 using both lower and upper case letters, but some are case
485 sensitive. This makes a big difference for user_max_ip ACL
486 processing and similar.
489 IF HAVE_AUTH_MODULE_DIGEST
490 === Digest authentication parameters ===
493 HTTP uses iso-latin-1 as character set, while some
494 authentication backends such as LDAP expects UTF-8. If this is
495 set to on Squid will translate the HTTP iso-latin-1 charset to
496 UTF-8 before sending the username and password to the helper.
498 "nonce_garbage_interval" timeinterval
499 Specifies the interval that nonces that have been issued
500 to client_agent's are checked for validity.
502 "nonce_max_duration" timeinterval
503 Specifies the maximum length of time a given nonce will be
506 "nonce_max_count" number
507 Specifies the maximum number of times a given nonce can be
510 "nonce_strictness" on|off
511 Determines if squid requires strict increment-by-1 behavior
512 for nonce counts, or just incrementing (off - for use when
513 user agents generate nonce counts that occasionally miss 1
514 (ie, 1,2,4,6)). Default off.
516 "check_nonce_count" on|off
517 This directive if set to off can disable the nonce count check
518 completely to work around buggy digest qop implementations in
519 certain mainstream browser versions. Default on to check the
520 nonce count to protect from authentication replay attacks.
522 "post_workaround" on|off
523 This is a workaround to certain buggy browsers who send an
524 incorrect request digest in POST requests when reusing the
525 same nonce as acquired earlier on a GET request.
528 IF HAVE_AUTH_MODULE_NEGOTIATE
529 === Negotiate authentication parameters ===
532 If you experience problems with PUT/POST requests when using
533 the this authentication scheme then you can try setting this
534 to off. This will cause Squid to forcibly close the connection
535 on the initial request where the browser asks which schemes
536 are supported by the proxy.
539 IF HAVE_AUTH_MODULE_NTLM
540 === NTLM authentication parameters ===
543 If you experience problems with PUT/POST requests when using
544 the this authentication scheme then you can try setting this
545 to off. This will cause Squid to forcibly close the connection
546 on the initial request where the browser asks which schemes
547 are supported by the proxy.
550 === Example Configuration ===
552 This configuration displays the recommended authentication scheme
553 order from most to least secure with recommended minimum configuration
554 settings for each scheme:
556 #auth_param negotiate program <uncomment and complete this line to activate>
557 #auth_param negotiate children 20 startup=0 idle=1
558 #auth_param negotiate keep_alive on
560 #auth_param digest program <uncomment and complete this line to activate>
561 #auth_param digest children 20 startup=0 idle=1
562 #auth_param digest realm Squid proxy-caching web server
563 #auth_param digest nonce_garbage_interval 5 minutes
564 #auth_param digest nonce_max_duration 30 minutes
565 #auth_param digest nonce_max_count 50
567 #auth_param ntlm program <uncomment and complete this line to activate>
568 #auth_param ntlm children 20 startup=0 idle=1
569 #auth_param ntlm keep_alive on
571 #auth_param basic program <uncomment and complete this line>
572 #auth_param basic children 5 startup=5 idle=1
573 #auth_param basic realm Squid proxy-caching web server
574 #auth_param basic credentialsttl 2 hours
577 NAME: authenticate_cache_garbage_interval
580 LOC: Config.authenticateGCInterval
582 The time period between garbage collection across the username cache.
583 This is a trade-off between memory utilization (long intervals - say
584 2 days) and CPU (short intervals - say 1 minute). Only change if you
588 NAME: authenticate_ttl
591 LOC: Config.authenticateTTL
593 The time a user & their credentials stay in the logged in
594 user cache since their last request. When the garbage
595 interval passes, all user credentials that have passed their
596 TTL are removed from memory.
599 NAME: authenticate_ip_ttl
601 LOC: Config.authenticateIpTTL
604 If you use proxy authentication and the 'max_user_ip' ACL,
605 this directive controls how long Squid remembers the IP
606 addresses associated with each user. Use a small value
607 (e.g., 60 seconds) if your users might change addresses
608 quickly, as is the case with dialup. You might be safe
609 using a larger value (e.g., 2 hours) in a corporate LAN
610 environment with relatively static address assignments.
615 -----------------------------------------------------------------------------
618 NAME: external_acl_type
619 TYPE: externalAclHelper
620 LOC: Config.externalAclHelperList
623 This option defines external acl classes using a helper program
624 to look up the status
626 external_acl_type name [options] FORMAT.. /path/to/helper [helper arguments..]
630 ttl=n TTL in seconds for cached results (defaults to 3600
633 TTL for cached negative lookups (default same
636 Maximum number of acl helper processes spawned to service
637 external acl lookups of this type. (default 20)
639 Minimum number of acl helper processes to spawn during
640 startup and reconfigure to service external acl lookups
641 of this type. (default 0)
643 Number of acl helper processes to keep ahead of traffic
644 loads. Squid will spawn this many at once whenever load
645 rises above the capabilities of existing processes.
646 Up to the value of children-max. (default 1)
647 concurrency=n concurrency level per process. Only used with helpers
648 capable of processing more than one query at a time.
649 cache=n limit the result cache size, default is 262144.
650 grace=n Percentage remaining of TTL where a refresh of a
651 cached entry should be initiated without needing to
652 wait for a new reply. (default is for no grace period)
653 protocol=2.5 Compatibility mode for Squid-2.5 external acl helpers
654 ipv4 / ipv6 IP protocol used to communicate with this helper.
655 The default is to auto-detect IPv6 and use it when available.
657 FORMAT specifications
659 %LOGIN Authenticated user login name
660 %EXT_USER Username from previous external acl
661 %EXT_LOG Log details from previous external acl
662 %EXT_TAG Tag from previous external acl
663 %IDENT Ident user name
665 %SRCPORT Client source port
668 %PROTO Requested URL scheme
670 %PATH Requested URL path
671 %METHOD Request method
672 %MYADDR Squid interface address
673 %MYPORT Squid http_port number
674 %PATH Requested URL-path (including query-string if any)
675 %USER_CERT SSL User certificate in PEM format
676 %USER_CERTCHAIN SSL User certificate chain in PEM format
677 %USER_CERT_xx SSL User certificate subject attribute xx
678 %USER_CA_CERT_xx SSL User certificate issuer attribute xx
679 %ssl::>sni SSL client SNI sent to Squid
680 %ssl::<cert_subject SSL server certificate DN
681 %ssl::<cert_issuer SSL server certificate issuer DN
683 %>{Header} HTTP request header "Header"
685 HTTP request header "Hdr" list member "member"
687 HTTP request header list member using ; as
688 list separator. ; can be any non-alphanumeric
691 %<{Header} HTTP reply header "Header"
693 HTTP reply header "Hdr" list member "member"
695 HTTP reply header list member using ; as
696 list separator. ; can be any non-alphanumeric
699 %ACL The name of the ACL being tested.
700 %DATA The ACL arguments. If not used then any arguments
701 is automatically added at the end of the line
703 NOTE: this will encode the arguments as one token,
704 whereas the default will pass each separately.
706 %% The percent sign. Useful for helpers which need
707 an unchanging input format.
710 General request syntax:
712 [channel-ID] FORMAT-values [acl-values ...]
715 FORMAT-values consists of transaction details expanded with
716 whitespace separation per the config file FORMAT specification
717 using the FORMAT macros listed above.
719 acl-values consists of any string specified in the referencing
720 config 'acl ... external' line. see the "acl external" directive.
722 Request values sent to the helper are URL escaped to protect
723 each value in requests against whitespaces.
725 If using protocol=2.5 then the request sent to the helper is not
726 URL escaped to protect against whitespace.
728 NOTE: protocol=3.0 is deprecated as no longer necessary.
730 When using the concurrency= option the protocol is changed by
731 introducing a query channel tag in front of the request/response.
732 The query channel tag is a number between 0 and concurrency-1.
733 This value must be echoed back unchanged to Squid as the first part
734 of the response relating to its request.
737 The helper receives lines expanded per the above format specification
738 and for each input line returns 1 line starting with OK/ERR/BH result
739 code and optionally followed by additional keywords with more details.
742 General result syntax:
744 [channel-ID] result keyword=value ...
746 Result consists of one of the codes:
749 the ACL test produced a match.
752 the ACL test does not produce a match.
755 An internal error occurred in the helper, preventing
756 a result being identified.
758 The meaning of 'a match' is determined by your squid.conf
759 access control configuration. See the Squid wiki for details.
763 user= The users name (login)
765 password= The users password (for login= cache_peer option)
767 message= Message describing the reason for this response.
768 Available as %o in error pages.
769 Useful on (ERR and BH results).
771 tag= Apply a tag to a request. Only sets a tag once,
772 does not alter existing tags.
774 log= String to be logged in access.log. Available as
775 %ea in logformat specifications.
777 clt_conn_tag= Associates a TAG with the client TCP connection.
778 Please see url_rewrite_program related documentation for
781 Any keywords may be sent on any response whether OK, ERR or BH.
783 All response keyword values need to be a single token with URL
784 escaping, or enclosed in double quotes (") and escaped using \ on
785 any double quotes or \ characters within the value. The wrapping
786 double quotes are removed before the value is interpreted by Squid.
787 \r and \n are also replace by CR and LF.
789 Some example key values:
793 user="J. \"Bob\" Smith"
800 DEFAULT: ssl::certHasExpired ssl_error X509_V_ERR_CERT_HAS_EXPIRED
801 DEFAULT: ssl::certNotYetValid ssl_error X509_V_ERR_CERT_NOT_YET_VALID
802 DEFAULT: ssl::certDomainMismatch ssl_error SQUID_X509_V_ERR_DOMAIN_MISMATCH
803 DEFAULT: ssl::certUntrusted ssl_error X509_V_ERR_INVALID_CA X509_V_ERR_SELF_SIGNED_CERT_IN_CHAIN X509_V_ERR_UNABLE_TO_VERIFY_LEAF_SIGNATURE X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT X509_V_ERR_UNABLE_TO_GET_ISSUER_CERT_LOCALLY X509_V_ERR_CERT_UNTRUSTED
804 DEFAULT: ssl::certSelfSigned ssl_error X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT
807 DEFAULT: manager url_regex -i ^cache_object:// +i ^https?://[^/]+/squid-internal-mgr/
808 DEFAULT: localhost src 127.0.0.1/32 ::1
809 DEFAULT: to_localhost dst 127.0.0.0/8 0.0.0.0/32 ::1
810 DEFAULT_DOC: ACLs all, manager, localhost, and to_localhost are predefined.
812 Defining an Access List
814 Every access list definition must begin with an aclname and acltype,
815 followed by either type-specific arguments or a quoted filename that
818 acl aclname acltype argument ...
819 acl aclname acltype "file" ...
821 When using "file", the file should contain one item per line.
823 Some acl types supports options which changes their default behaviour.
824 The available options are:
826 -i,+i By default, regular expressions are CASE-SENSITIVE. To make them
827 case-insensitive, use the -i option. To return case-sensitive
828 use the +i option between patterns, or make a new ACL line
831 -n Disable lookups and address type conversions. If lookup or
832 conversion is required because the parameter type (IP or
833 domain name) does not match the message address type (domain
834 name or IP), then the ACL would immediately declare a mismatch
835 without any warnings or lookups.
837 -- Used to stop processing all options, in the case the first acl
838 value has '-' character as first character (for example the '-'
839 is a valid domain name)
841 Some acl types require suspending the current request in order
842 to access some external data source.
843 Those which do are marked with the tag [slow], those which
844 don't are marked as [fast].
845 See http://wiki.squid-cache.org/SquidFaq/SquidAcl
846 for further information
848 ***** ACL TYPES AVAILABLE *****
850 acl aclname src ip-address/mask ... # clients IP address [fast]
851 acl aclname src addr1-addr2/mask ... # range of addresses [fast]
852 acl aclname dst [-n] ip-address/mask ... # URL host's IP address [slow]
853 acl aclname localip ip-address/mask ... # IP address the client connected to [fast]
855 acl aclname arp mac-address ... (xx:xx:xx:xx:xx:xx notation)
856 # The arp ACL requires the special configure option --enable-arp-acl.
857 # Furthermore, the ARP ACL code is not portable to all operating systems.
858 # It works on Linux, Solaris, Windows, FreeBSD, and some
859 # other *BSD variants.
862 # NOTE: Squid can only determine the MAC address for clients that are on
863 # the same subnet. If the client is on a different subnet,
864 # then Squid cannot find out its MAC address.
866 acl aclname srcdomain .foo.com ...
867 # reverse lookup, from client IP [slow]
868 acl aclname dstdomain [-n] .foo.com ...
869 # Destination server from URL [fast]
870 acl aclname srcdom_regex [-i] \.foo\.com ...
871 # regex matching client name [slow]
872 acl aclname dstdom_regex [-n] [-i] \.foo\.com ...
873 # regex matching server [fast]
875 # For dstdomain and dstdom_regex a reverse lookup is tried if a IP
876 # based URL is used and no match is found. The name "none" is used
877 # if the reverse lookup fails.
879 acl aclname src_as number ...
880 acl aclname dst_as number ...
882 # Except for access control, AS numbers can be used for
883 # routing of requests to specific caches. Here's an
884 # example for routing all requests for AS#1241 and only
885 # those to mycache.mydomain.net:
886 # acl asexample dst_as 1241
887 # cache_peer_access mycache.mydomain.net allow asexample
888 # cache_peer_access mycache_mydomain.net deny all
890 acl aclname peername myPeer ...
892 # match against a named cache_peer entry
893 # set unique name= on cache_peer lines for reliable use.
895 acl aclname time [day-abbrevs] [h1:m1-h2:m2]
905 # h1:m1 must be less than h2:m2
907 acl aclname url_regex [-i] ^http:// ...
908 # regex matching on whole URL [fast]
909 acl aclname urllogin [-i] [^a-zA-Z0-9] ...
910 # regex matching on URL login field
911 acl aclname urlpath_regex [-i] \.gif$ ...
912 # regex matching on URL path [fast]
914 acl aclname port 80 70 21 0-1024... # destination TCP port [fast]
916 acl aclname localport 3128 ... # TCP port the client connected to [fast]
917 # NP: for interception mode this is usually '80'
919 acl aclname myportname 3128 ... # *_port name [fast]
921 acl aclname proto HTTP FTP ... # request protocol [fast]
923 acl aclname method GET POST ... # HTTP request method [fast]
925 acl aclname http_status 200 301 500- 400-403 ...
926 # status code in reply [fast]
928 acl aclname browser [-i] regexp ...
929 # pattern match on User-Agent header (see also req_header below) [fast]
931 acl aclname referer_regex [-i] regexp ...
932 # pattern match on Referer header [fast]
933 # Referer is highly unreliable, so use with care
935 acl aclname ident username ...
936 acl aclname ident_regex [-i] pattern ...
937 # string match on ident output [slow]
938 # use REQUIRED to accept any non-null ident.
940 acl aclname proxy_auth [-i] username ...
941 acl aclname proxy_auth_regex [-i] pattern ...
942 # perform http authentication challenge to the client and match against
943 # supplied credentials [slow]
945 # takes a list of allowed usernames.
946 # use REQUIRED to accept any valid username.
948 # Will use proxy authentication in forward-proxy scenarios, and plain
949 # http authenticaiton in reverse-proxy scenarios
951 # NOTE: when a Proxy-Authentication header is sent but it is not
952 # needed during ACL checking the username is NOT logged
955 # NOTE: proxy_auth requires a EXTERNAL authentication program
956 # to check username/password combinations (see
957 # auth_param directive).
959 # NOTE: proxy_auth can't be used in a transparent/intercepting proxy
960 # as the browser needs to be configured for using a proxy in order
961 # to respond to proxy authentication.
963 acl aclname snmp_community string ...
964 # A community string to limit access to your SNMP Agent [fast]
967 # acl snmppublic snmp_community public
969 acl aclname maxconn number
970 # This will be matched when the client's IP address has
971 # more than <number> TCP connections established. [fast]
972 # NOTE: This only measures direct TCP links so X-Forwarded-For
973 # indirect clients are not counted.
975 acl aclname max_user_ip [-s] number
976 # This will be matched when the user attempts to log in from more
977 # than <number> different ip addresses. The authenticate_ip_ttl
978 # parameter controls the timeout on the ip entries. [fast]
979 # If -s is specified the limit is strict, denying browsing
980 # from any further IP addresses until the ttl has expired. Without
981 # -s Squid will just annoy the user by "randomly" denying requests.
982 # (the counter is reset each time the limit is reached and a
984 # NOTE: in acceleration mode or where there is mesh of child proxies,
985 # clients may appear to come from multiple addresses if they are
986 # going through proxy farms, so a limit of 1 may cause user problems.
988 acl aclname random probability
989 # Pseudo-randomly match requests. Based on the probability given.
990 # Probability may be written as a decimal (0.333), fraction (1/3)
991 # or ratio of matches:non-matches (3:5).
993 acl aclname req_mime_type [-i] mime-type ...
994 # regex match against the mime type of the request generated
995 # by the client. Can be used to detect file upload or some
996 # types HTTP tunneling requests [fast]
997 # NOTE: This does NOT match the reply. You cannot use this
998 # to match the returned file type.
1000 acl aclname req_header header-name [-i] any\.regex\.here
1001 # regex match against any of the known request headers. May be
1002 # thought of as a superset of "browser", "referer" and "mime-type"
1005 acl aclname rep_mime_type [-i] mime-type ...
1006 # regex match against the mime type of the reply received by
1007 # squid. Can be used to detect file download or some
1008 # types HTTP tunneling requests. [fast]
1009 # NOTE: This has no effect in http_access rules. It only has
1010 # effect in rules that affect the reply data stream such as
1011 # http_reply_access.
1013 acl aclname rep_header header-name [-i] any\.regex\.here
1014 # regex match against any of the known reply headers. May be
1015 # thought of as a superset of "browser", "referer" and "mime-type"
1018 acl aclname external class_name [arguments...]
1019 # external ACL lookup via a helper class defined by the
1020 # external_acl_type directive [slow]
1022 acl aclname user_cert attribute values...
1023 # match against attributes in a user SSL certificate
1024 # attribute is one of DN/C/O/CN/L/ST [fast]
1026 acl aclname ca_cert attribute values...
1027 # match against attributes a users issuing CA SSL certificate
1028 # attribute is one of DN/C/O/CN/L/ST [fast]
1030 acl aclname ext_user username ...
1031 acl aclname ext_user_regex [-i] pattern ...
1032 # string match on username returned by external acl helper [slow]
1033 # use REQUIRED to accept any non-null user name.
1035 acl aclname tag tagvalue ...
1036 # string match on tag returned by external acl helper [fast]
1037 # DEPRECATED. Only the first tag will match with this ACL.
1038 # Use the 'note' ACL instead for handling multiple tag values.
1040 acl aclname hier_code codename ...
1041 # string match against squid hierarchy code(s); [fast]
1042 # e.g., DIRECT, PARENT_HIT, NONE, etc.
1044 # NOTE: This has no effect in http_access rules. It only has
1045 # effect in rules that affect the reply data stream such as
1046 # http_reply_access.
1048 acl aclname note name [value ...]
1049 # match transaction annotation [fast]
1050 # Without values, matches any annotation with a given name.
1051 # With value(s), matches any annotation with a given name that
1052 # also has one of the given values.
1053 # Names and values are compared using a string equality test.
1054 # Annotation sources include note and adaptation_meta directives
1055 # as well as helper and eCAP responses.
1057 acl aclname adaptation_service service ...
1058 # Matches the name of any icap_service, ecap_service,
1059 # adaptation_service_set, or adaptation_service_chain that Squid
1060 # has used (or attempted to use) for the master transaction.
1061 # This ACL must be defined after the corresponding adaptation
1062 # service is named in squid.conf. This ACL is usable with
1063 # adaptation_meta because it starts matching immediately after
1064 # the service has been selected for adaptation.
1067 acl aclname ssl_error errorname
1068 # match against SSL certificate validation error [fast]
1070 # For valid error names see in @DEFAULT_ERROR_DIR@/templates/error-details.txt
1073 # The following can be used as shortcuts for certificate properties:
1074 # [ssl::]certHasExpired: the "not after" field is in the past
1075 # [ssl::]certNotYetValid: the "not before" field is in the future
1076 # [ssl::]certUntrusted: The certificate issuer is not to be trusted.
1077 # [ssl::]certSelfSigned: The certificate is self signed.
1078 # [ssl::]certDomainMismatch: The certificate CN domain does not
1079 # match the name the name of the host we are connecting to.
1081 # The ssl::certHasExpired, ssl::certNotYetValid, ssl::certDomainMismatch,
1082 # ssl::certUntrusted, and ssl::certSelfSigned can also be used as
1083 # predefined ACLs, just like the 'all' ACL.
1085 # NOTE: The ssl_error ACL is only supported with sslproxy_cert_error,
1086 # sslproxy_cert_sign, and sslproxy_cert_adapt options.
1088 acl aclname server_cert_fingerprint [-sha1] fingerprint
1089 # match against server SSL certificate fingerprint [fast]
1091 # The fingerprint is the digest of the DER encoded version
1092 # of the whole certificate. The user should use the form: XX:XX:...
1093 # Optional argument specifies the digest algorithm to use.
1094 # The SHA1 digest algorithm is the default and is currently
1095 # the only algorithm supported (-sha1).
1097 acl aclname at_step step
1098 # match against the current step during ssl_bump evaluation [fast]
1099 # Never matches and should not be used outside the ssl_bump context.
1101 # At each SslBump step, Squid evaluates ssl_bump directives to find
1102 # the next bumping action (e.g., peek or splice). Valid SslBump step
1103 # values and the corresponding ssl_bump evaluation moments are:
1104 # SslBump1: After getting TCP-level and HTTP CONNECT info.
1105 # SslBump2: After getting SSL Client Hello info.
1106 # SslBump3: After getting SSL Server Hello info.
1108 acl aclname any-of acl1 acl2 ...
1109 # match any one of the acls [fast or slow]
1110 # The first matching ACL stops further ACL evaluation.
1112 # ACLs from multiple any-of lines with the same name are ORed.
1113 # For example, A = (a1 or a2) or (a3 or a4) can be written as
1114 # acl A any-of a1 a2
1115 # acl A any-of a3 a4
1117 # This group ACL is fast if all evaluated ACLs in the group are fast
1118 # and slow otherwise.
1120 acl aclname all-of acl1 acl2 ...
1121 # match all of the acls [fast or slow]
1122 # The first mismatching ACL stops further ACL evaluation.
1124 # ACLs from multiple all-of lines with the same name are ORed.
1125 # For example, B = (b1 and b2) or (b3 and b4) can be written as
1126 # acl B all-of b1 b2
1127 # acl B all-of b3 b4
1129 # This group ACL is fast if all evaluated ACLs in the group are fast
1130 # and slow otherwise.
1133 acl macaddress arp 09:00:2b:23:45:67
1134 acl myexample dst_as 1241
1135 acl password proxy_auth REQUIRED
1136 acl fileupload req_mime_type -i ^multipart/form-data$
1137 acl javascript rep_mime_type -i ^application/x-javascript$
1141 # Recommended minimum configuration:
1144 # Example rule allowing access from your local networks.
1145 # Adapt to list your (internal) IP networks from where browsing
1147 acl localnet src 10.0.0.0/8 # RFC1918 possible internal network
1148 acl localnet src 172.16.0.0/12 # RFC1918 possible internal network
1149 acl localnet src 192.168.0.0/16 # RFC1918 possible internal network
1150 acl localnet src fc00::/7 # RFC 4193 local private network range
1151 acl localnet src fe80::/10 # RFC 4291 link-local (directly plugged) machines
1153 acl SSL_ports port 443
1154 acl Safe_ports port 80 # http
1155 acl Safe_ports port 21 # ftp
1156 acl Safe_ports port 443 # https
1157 acl Safe_ports port 70 # gopher
1158 acl Safe_ports port 210 # wais
1159 acl Safe_ports port 1025-65535 # unregistered ports
1160 acl Safe_ports port 280 # http-mgmt
1161 acl Safe_ports port 488 # gss-http
1162 acl Safe_ports port 591 # filemaker
1163 acl Safe_ports port 777 # multiling http
1164 acl CONNECT method CONNECT
1168 NAME: proxy_protocol_access
1170 LOC: Config.accessList.proxyProtocol
1172 DEFAULT_DOC: all TCP connections to ports with require-proxy-header will be denied
1174 Determine which client proxies can be trusted to provide correct
1175 information regarding real client IP address using PROXY protocol.
1177 Requests may pass through a chain of several other proxies
1178 before reaching us. The original source details may by sent in:
1179 * HTTP message Forwarded header, or
1180 * HTTP message X-Forwarded-For header, or
1181 * PROXY protocol connection header.
1183 This directive is solely for validating new PROXY protocol
1184 connections received from a port flagged with require-proxy-header.
1185 It is checked only once after TCP connection setup.
1187 A deny match results in TCP connection closure.
1189 An allow match is required for Squid to permit the corresponding
1190 TCP connection, before Squid even looks for HTTP request headers.
1191 If there is an allow match, Squid starts using PROXY header information
1192 to determine the source address of the connection for all future ACL
1193 checks, logging, etc.
1195 SECURITY CONSIDERATIONS:
1197 Any host from which we accept client IP details can place
1198 incorrect information in the relevant header, and Squid
1199 will use the incorrect information as if it were the
1200 source address of the request. This may enable remote
1201 hosts to bypass any access control restrictions that are
1202 based on the client's source addresses.
1204 This clause only supports fast acl types.
1205 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1208 NAME: follow_x_forwarded_for
1210 IFDEF: FOLLOW_X_FORWARDED_FOR
1211 LOC: Config.accessList.followXFF
1212 DEFAULT_IF_NONE: deny all
1213 DEFAULT_DOC: X-Forwarded-For header will be ignored.
1215 Determine which client proxies can be trusted to provide correct
1216 information regarding real client IP address.
1218 Requests may pass through a chain of several other proxies
1219 before reaching us. The original source details may by sent in:
1220 * HTTP message Forwarded header, or
1221 * HTTP message X-Forwarded-For header, or
1222 * PROXY protocol connection header.
1224 PROXY protocol connections are controlled by the proxy_protocol_access
1225 directive which is checked before this.
1227 If a request reaches us from a source that is allowed by this
1228 directive, then we trust the information it provides regarding
1229 the IP of the client it received from (if any).
1231 For the purpose of ACLs used in this directive the src ACL type always
1232 matches the address we are testing and srcdomain matches its rDNS.
1234 On each HTTP request Squid checks for X-Forwarded-For header fields.
1235 If found the header values are iterated in reverse order and an allow
1236 match is required for Squid to continue on to the next value.
1237 The verification ends when a value receives a deny match, cannot be
1238 tested, or there are no more values to test.
1239 NOTE: Squid does not yet follow the Forwarded HTTP header.
1241 The end result of this process is an IP address that we will
1242 refer to as the indirect client address. This address may
1243 be treated as the client address for access control, ICAP, delay
1244 pools and logging, depending on the acl_uses_indirect_client,
1245 icap_uses_indirect_client, delay_pool_uses_indirect_client,
1246 log_uses_indirect_client and tproxy_uses_indirect_client options.
1248 This clause only supports fast acl types.
1249 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1251 SECURITY CONSIDERATIONS:
1253 Any host from which we accept client IP details can place
1254 incorrect information in the relevant header, and Squid
1255 will use the incorrect information as if it were the
1256 source address of the request. This may enable remote
1257 hosts to bypass any access control restrictions that are
1258 based on the client's source addresses.
1262 acl localhost src 127.0.0.1
1263 acl my_other_proxy srcdomain .proxy.example.com
1264 follow_x_forwarded_for allow localhost
1265 follow_x_forwarded_for allow my_other_proxy
1268 NAME: acl_uses_indirect_client
1271 IFDEF: FOLLOW_X_FORWARDED_FOR
1273 LOC: Config.onoff.acl_uses_indirect_client
1275 Controls whether the indirect client address
1276 (see follow_x_forwarded_for) is used instead of the
1277 direct client address in acl matching.
1279 NOTE: maxconn ACL considers direct TCP links and indirect
1280 clients will always have zero. So no match.
1283 NAME: delay_pool_uses_indirect_client
1286 IFDEF: FOLLOW_X_FORWARDED_FOR&&USE_DELAY_POOLS
1288 LOC: Config.onoff.delay_pool_uses_indirect_client
1290 Controls whether the indirect client address
1291 (see follow_x_forwarded_for) is used instead of the
1292 direct client address in delay pools.
1295 NAME: log_uses_indirect_client
1298 IFDEF: FOLLOW_X_FORWARDED_FOR
1300 LOC: Config.onoff.log_uses_indirect_client
1302 Controls whether the indirect client address
1303 (see follow_x_forwarded_for) is used instead of the
1304 direct client address in the access log.
1307 NAME: tproxy_uses_indirect_client
1310 IFDEF: FOLLOW_X_FORWARDED_FOR&&LINUX_NETFILTER
1312 LOC: Config.onoff.tproxy_uses_indirect_client
1314 Controls whether the indirect client address
1315 (see follow_x_forwarded_for) is used instead of the
1316 direct client address when spoofing the outgoing client.
1318 This has no effect on requests arriving in non-tproxy
1321 SECURITY WARNING: Usage of this option is dangerous
1322 and should not be used trivially. Correct configuration
1323 of follow_x_forewarded_for with a limited set of trusted
1324 sources is required to prevent abuse of your proxy.
1327 NAME: spoof_client_ip
1329 LOC: Config.accessList.spoof_client_ip
1331 DEFAULT_DOC: Allow spoofing on all TPROXY traffic.
1333 Control client IP address spoofing of TPROXY traffic based on
1334 defined access lists.
1336 spoof_client_ip allow|deny [!]aclname ...
1338 If there are no "spoof_client_ip" lines present, the default
1339 is to "allow" spoofing of any suitable request.
1341 Note that the cache_peer "no-tproxy" option overrides this ACL.
1343 This clause supports fast acl types.
1344 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1349 LOC: Config.accessList.http
1350 DEFAULT_IF_NONE: deny all
1351 DEFAULT_DOC: Deny, unless rules exist in squid.conf.
1353 Allowing or Denying access based on defined access lists
1355 To allow or deny a message received on an HTTP, HTTPS, or FTP port:
1356 http_access allow|deny [!]aclname ...
1358 NOTE on default values:
1360 If there are no "access" lines present, the default is to deny
1363 If none of the "access" lines cause a match, the default is the
1364 opposite of the last line in the list. If the last line was
1365 deny, the default is allow. Conversely, if the last line
1366 is allow, the default will be deny. For these reasons, it is a
1367 good idea to have an "deny all" entry at the end of your access
1368 lists to avoid potential confusion.
1370 This clause supports both fast and slow acl types.
1371 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1376 # Recommended minimum Access Permission configuration:
1378 # Deny requests to certain unsafe ports
1379 http_access deny !Safe_ports
1381 # Deny CONNECT to other than secure SSL ports
1382 http_access deny CONNECT !SSL_ports
1384 # Only allow cachemgr access from localhost
1385 http_access allow localhost manager
1386 http_access deny manager
1388 # We strongly recommend the following be uncommented to protect innocent
1389 # web applications running on the proxy server who think the only
1390 # one who can access services on "localhost" is a local user
1391 #http_access deny to_localhost
1394 # INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS
1397 # Example rule allowing access from your local networks.
1398 # Adapt localnet in the ACL section to list your (internal) IP networks
1399 # from where browsing should be allowed
1400 http_access allow localnet
1401 http_access allow localhost
1403 # And finally deny all other access to this proxy
1404 http_access deny all
1408 NAME: adapted_http_access http_access2
1410 LOC: Config.accessList.adapted_http
1412 DEFAULT_DOC: Allow, unless rules exist in squid.conf.
1414 Allowing or Denying access based on defined access lists
1416 Essentially identical to http_access, but runs after redirectors
1417 and ICAP/eCAP adaptation. Allowing access control based on their
1420 If not set then only http_access is used.
1423 NAME: http_reply_access
1425 LOC: Config.accessList.reply
1427 DEFAULT_DOC: Allow, unless rules exist in squid.conf.
1429 Allow replies to client requests. This is complementary to http_access.
1431 http_reply_access allow|deny [!] aclname ...
1433 NOTE: if there are no access lines present, the default is to allow
1436 If none of the access lines cause a match the opposite of the
1437 last line will apply. Thus it is good practice to end the rules
1438 with an "allow all" or "deny all" entry.
1440 This clause supports both fast and slow acl types.
1441 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1446 LOC: Config.accessList.icp
1448 DEFAULT_DOC: Deny, unless rules exist in squid.conf.
1450 Allowing or Denying access to the ICP port based on defined
1453 icp_access allow|deny [!]aclname ...
1455 NOTE: The default if no icp_access lines are present is to
1456 deny all traffic. This default may cause problems with peers
1459 This clause only supports fast acl types.
1460 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1462 # Allow ICP queries from local networks only
1463 #icp_access allow localnet
1464 #icp_access deny all
1470 LOC: Config.accessList.htcp
1472 DEFAULT_DOC: Deny, unless rules exist in squid.conf.
1474 Allowing or Denying access to the HTCP port based on defined
1477 htcp_access allow|deny [!]aclname ...
1479 See also htcp_clr_access for details on access control for
1480 cache purge (CLR) HTCP messages.
1482 NOTE: The default if no htcp_access lines are present is to
1483 deny all traffic. This default may cause problems with peers
1484 using the htcp option.
1486 This clause only supports fast acl types.
1487 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1489 # Allow HTCP queries from local networks only
1490 #htcp_access allow localnet
1491 #htcp_access deny all
1494 NAME: htcp_clr_access
1497 LOC: Config.accessList.htcp_clr
1499 DEFAULT_DOC: Deny, unless rules exist in squid.conf.
1501 Allowing or Denying access to purge content using HTCP based
1502 on defined access lists.
1503 See htcp_access for details on general HTCP access control.
1505 htcp_clr_access allow|deny [!]aclname ...
1507 This clause only supports fast acl types.
1508 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1510 # Allow HTCP CLR requests from trusted peers
1511 acl htcp_clr_peer src 192.0.2.2 2001:DB8::2
1512 htcp_clr_access allow htcp_clr_peer
1513 htcp_clr_access deny all
1518 LOC: Config.accessList.miss
1520 DEFAULT_DOC: Allow, unless rules exist in squid.conf.
1522 Determins whether network access is permitted when satisfying a request.
1525 to force your neighbors to use you as a sibling instead of
1528 acl localclients src 192.0.2.0/24 2001:DB8::a:0/64
1529 miss_access deny !localclients
1530 miss_access allow all
1532 This means only your local clients are allowed to fetch relayed/MISS
1533 replies from the network and all other clients can only fetch cached
1536 The default for this setting allows all clients who passed the
1537 http_access rules to relay via this proxy.
1539 This clause only supports fast acl types.
1540 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1543 NAME: ident_lookup_access
1547 DEFAULT_DOC: Unless rules exist in squid.conf, IDENT is not fetched.
1548 LOC: Ident::TheConfig.identLookup
1550 A list of ACL elements which, if matched, cause an ident
1551 (RFC 931) lookup to be performed for this request. For
1552 example, you might choose to always perform ident lookups
1553 for your main multi-user Unix boxes, but not for your Macs
1554 and PCs. By default, ident lookups are not performed for
1557 To enable ident lookups for specific client addresses, you
1558 can follow this example:
1560 acl ident_aware_hosts src 198.168.1.0/24
1561 ident_lookup_access allow ident_aware_hosts
1562 ident_lookup_access deny all
1564 Only src type ACL checks are fully supported. A srcdomain
1565 ACL might work at times, but it will not always provide
1568 This clause only supports fast acl types.
1569 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1572 NAME: reply_body_max_size
1573 COMMENT: size [acl acl...]
1576 DEFAULT_DOC: No limit is applied.
1577 LOC: Config.ReplyBodySize
1579 This option specifies the maximum size of a reply body. It can be
1580 used to prevent users from downloading very large files, such as
1581 MP3's and movies. When the reply headers are received, the
1582 reply_body_max_size lines are processed, and the first line where
1583 all (if any) listed ACLs are true is used as the maximum body size
1586 This size is checked twice. First when we get the reply headers,
1587 we check the content-length value. If the content length value exists
1588 and is larger than the allowed size, the request is denied and the
1589 user receives an error message that says "the request or reply
1590 is too large." If there is no content-length, and the reply
1591 size exceeds this limit, the client's connection is just closed
1592 and they will receive a partial reply.
1594 WARNING: downstream caches probably can not detect a partial reply
1595 if there is no content-length header, so they will cache
1596 partial responses and give them out as hits. You should NOT
1597 use this option if you have downstream caches.
1599 WARNING: A maximum size smaller than the size of squid's error messages
1600 will cause an infinite loop and crash squid. Ensure that the smallest
1601 non-zero value you use is greater that the maximum header size plus
1602 the size of your largest error page.
1604 If you set this parameter none (the default), there will be
1607 Configuration Format is:
1608 reply_body_max_size SIZE UNITS [acl ...]
1610 reply_body_max_size 10 MB
1616 -----------------------------------------------------------------------------
1619 NAME: http_port ascii_port
1624 Usage: port [mode] [options]
1625 hostname:port [mode] [options]
1626 1.2.3.4:port [mode] [options]
1628 The socket addresses where Squid will listen for HTTP client
1629 requests. You may specify multiple socket addresses.
1630 There are three forms: port alone, hostname with port, and
1631 IP address with port. If you specify a hostname or IP
1632 address, Squid binds the socket to that specific
1633 address. Most likely, you do not need to bind to a specific
1634 address, so you can use the port number alone.
1636 If you are running Squid in accelerator mode, you
1637 probably want to listen on port 80 also, or instead.
1639 The -a command line option may be used to specify additional
1640 port(s) where Squid listens for proxy request. Such ports will
1641 be plain proxy ports with no options.
1643 You may specify multiple socket addresses on multiple lines.
1647 intercept Support for IP-Layer interception of
1648 outgoing requests without browser settings.
1649 NP: disables authentication and IPv6 on the port.
1651 tproxy Support Linux TPROXY for spoofing outgoing
1652 connections using the client IP address.
1653 NP: disables authentication and maybe IPv6 on the port.
1655 accel Accelerator / reverse proxy mode
1657 ssl-bump For each CONNECT request allowed by ssl_bump ACLs,
1658 establish secure connection with the client and with
1659 the server, decrypt HTTPS messages as they pass through
1660 Squid, and treat them as unencrypted HTTP messages,
1661 becoming the man-in-the-middle.
1663 The ssl_bump option is required to fully enable
1664 bumping of CONNECT requests.
1666 Omitting the mode flag causes default forward proxy mode to be used.
1669 Accelerator Mode Options:
1671 defaultsite=domainname
1672 What to use for the Host: header if it is not present
1673 in a request. Determines what site (not origin server)
1674 accelerators should consider the default.
1676 no-vhost Disable using HTTP/1.1 Host header for virtual domain support.
1678 protocol= Protocol to reconstruct accelerated and intercepted
1679 requests with. Defaults to HTTP/1.1 for http_port and
1680 HTTPS/1.1 for https_port.
1681 When an unsupported value is configured Squid will
1682 produce a FATAL error.
1683 Values: HTTP or HTTP/1.1, HTTPS or HTTPS/1.1
1685 vport Virtual host port support. Using the http_port number
1686 instead of the port passed on Host: headers.
1688 vport=NN Virtual host port support. Using the specified port
1689 number instead of the port passed on Host: headers.
1692 Act as if this Squid is the origin server.
1693 This currently means generate new Date: and Expires:
1694 headers on HIT instead of adding Age:.
1696 ignore-cc Ignore request Cache-Control headers.
1698 WARNING: This option violates HTTP specifications if
1699 used in non-accelerator setups.
1701 allow-direct Allow direct forwarding in accelerator mode. Normally
1702 accelerated requests are denied direct forwarding as if
1703 never_direct was used.
1705 WARNING: this option opens accelerator mode to security
1706 vulnerabilities usually only affecting in interception
1707 mode. Make sure to protect forwarding with suitable
1708 http_access rules when using this.
1711 SSL Bump Mode Options:
1712 In addition to these options ssl-bump requires TLS/SSL options.
1714 generate-host-certificates[=<on|off>]
1715 Dynamically create SSL server certificates for the
1716 destination hosts of bumped CONNECT requests.When
1717 enabled, the cert and key options are used to sign
1718 generated certificates. Otherwise generated
1719 certificate will be selfsigned.
1720 If there is a CA certificate lifetime of the generated
1721 certificate equals lifetime of the CA certificate. If
1722 generated certificate is selfsigned lifetime is three
1724 This option is enabled by default when ssl-bump is used.
1725 See the ssl-bump option above for more information.
1727 dynamic_cert_mem_cache_size=SIZE
1728 Approximate total RAM size spent on cached generated
1729 certificates. If set to zero, caching is disabled. The
1730 default value is 4MB.
1734 cert= Path to SSL certificate (PEM format).
1736 key= Path to SSL private key file (PEM format)
1737 if not specified, the certificate file is
1738 assumed to be a combined certificate and
1741 version= The version of SSL/TLS supported
1742 1 automatic (default)
1749 cipher= Colon separated list of supported ciphers.
1750 NOTE: some ciphers such as EDH ciphers depend on
1751 additional settings. If those settings are
1752 omitted the ciphers may be silently ignored
1753 by the OpenSSL library.
1755 options= Various SSL implementation options. The most important
1757 NO_SSLv2 Disallow the use of SSLv2
1758 NO_SSLv3 Disallow the use of SSLv3
1759 NO_TLSv1 Disallow the use of TLSv1.0
1760 NO_TLSv1_1 Disallow the use of TLSv1.1
1761 NO_TLSv1_2 Disallow the use of TLSv1.2
1762 SINGLE_DH_USE Always create a new key when using
1763 temporary/ephemeral DH key exchanges
1764 ALL Enable various bug workarounds
1765 suggested as "harmless" by OpenSSL
1766 Be warned that this reduces SSL/TLS
1767 strength to some attacks.
1768 See OpenSSL SSL_CTX_set_options documentation for a
1769 complete list of options.
1771 clientca= File containing the list of CAs to use when
1772 requesting a client certificate.
1774 cafile= File containing additional CA certificates to
1775 use when verifying client certificates. If unset
1776 clientca will be used.
1778 capath= Directory containing additional CA certificates
1779 and CRL lists to use when verifying client certificates.
1781 crlfile= File of additional CRL lists to use when verifying
1782 the client certificate, in addition to CRLs stored in
1783 the capath. Implies VERIFY_CRL flag below.
1785 dhparams= File containing DH parameters for temporary/ephemeral
1786 DH key exchanges. See OpenSSL documentation for details
1787 on how to create this file.
1788 WARNING: EDH ciphers will be silently disabled if this
1791 sslflags= Various flags modifying the use of SSL:
1793 Don't request client certificates
1794 immediately, but wait until acl processing
1795 requires a certificate (not yet implemented).
1797 Don't use the default CA lists built in
1800 Don't allow for session reuse. Each connection
1801 will result in a new SSL session.
1803 Verify CRL lists when accepting client
1806 Verify CRL lists for all certificates in the
1807 client certificate chain.
1809 sslcontext= SSL session ID context identifier.
1813 connection-auth[=on|off]
1814 use connection-auth=off to tell Squid to prevent
1815 forwarding Microsoft connection oriented authentication
1816 (NTLM, Negotiate and Kerberos)
1818 disable-pmtu-discovery=
1819 Control Path-MTU discovery usage:
1820 off lets OS decide on what to do (default).
1821 transparent disable PMTU discovery when transparent
1823 always disable always PMTU discovery.
1825 In many setups of transparently intercepting proxies
1826 Path-MTU discovery can not work on traffic towards the
1827 clients. This is the case when the intercepting device
1828 does not fully track connections and fails to forward
1829 ICMP must fragment messages to the cache server. If you
1830 have such setup and experience that certain clients
1831 sporadically hang or never complete requests set
1832 disable-pmtu-discovery option to 'transparent'.
1834 name= Specifies a internal name for the port. Defaults to
1835 the port specification (port or addr:port)
1837 tcpkeepalive[=idle,interval,timeout]
1838 Enable TCP keepalive probes of idle connections.
1839 In seconds; idle is the initial time before TCP starts
1840 probing the connection, interval how often to probe, and
1841 timeout the time before giving up.
1843 require-proxy-header
1844 Require PROXY protocol version 1 or 2 connections.
1845 The proxy_protocol_access is required to whitelist
1846 downstream proxies which can be trusted.
1848 If you run Squid on a dual-homed machine with an internal
1849 and an external interface we recommend you to specify the
1850 internal address:port in http_port. This way Squid will only be
1851 visible on the internal address.
1855 # Squid normally listens to port 3128
1856 http_port @DEFAULT_HTTP_PORT@
1866 Usage: [ip:]port cert=certificate.pem [key=key.pem] [mode] [options...]
1868 The socket address where Squid will listen for client requests made
1869 over TLS or SSL connections. Commonly referred to as HTTPS.
1871 This is most useful for situations where you are running squid in
1872 accelerator mode and you want to do the SSL work at the accelerator level.
1874 You may specify multiple socket addresses on multiple lines,
1875 each with their own SSL certificate and/or options.
1879 accel Accelerator / reverse proxy mode
1881 intercept Support for IP-Layer interception of
1882 outgoing requests without browser settings.
1883 NP: disables authentication and IPv6 on the port.
1885 tproxy Support Linux TPROXY for spoofing outgoing
1886 connections using the client IP address.
1887 NP: disables authentication and maybe IPv6 on the port.
1889 ssl-bump For each intercepted connection allowed by ssl_bump
1890 ACLs, establish a secure connection with the client and with
1891 the server, decrypt HTTPS messages as they pass through
1892 Squid, and treat them as unencrypted HTTP messages,
1893 becoming the man-in-the-middle.
1895 An "ssl_bump server-first" match is required to
1896 fully enable bumping of intercepted SSL connections.
1898 Requires tproxy or intercept.
1900 Omitting the mode flag causes default forward proxy mode to be used.
1903 See http_port for a list of generic options
1908 cert= Path to SSL certificate (PEM format).
1910 key= Path to SSL private key file (PEM format)
1911 if not specified, the certificate file is
1912 assumed to be a combined certificate and
1915 version= The version of SSL/TLS supported
1916 1 automatic (default)
1921 cipher= Colon separated list of supported ciphers.
1923 options= Various SSL engine options. The most important
1925 NO_SSLv2 Disallow the use of SSLv2
1926 NO_SSLv3 Disallow the use of SSLv3
1927 NO_TLSv1 Disallow the use of TLSv1
1928 SINGLE_DH_USE Always create a new key when using
1929 temporary/ephemeral DH key exchanges
1930 See src/ssl_support.c or OpenSSL SSL_CTX_set_options
1931 documentation for a complete list of options.
1933 clientca= File containing the list of CAs to use when
1934 requesting a client certificate.
1936 cafile= File containing additional CA certificates to
1937 use when verifying client certificates. If unset
1938 clientca will be used.
1940 capath= Directory containing additional CA certificates
1941 and CRL lists to use when verifying client certificates.
1943 crlfile= File of additional CRL lists to use when verifying
1944 the client certificate, in addition to CRLs stored in
1945 the capath. Implies VERIFY_CRL flag below.
1947 dhparams= File containing DH parameters for temporary/ephemeral
1950 sslflags= Various flags modifying the use of SSL:
1952 Don't request client certificates
1953 immediately, but wait until acl processing
1954 requires a certificate (not yet implemented).
1956 Don't use the default CA lists built in
1959 Don't allow for session reuse. Each connection
1960 will result in a new SSL session.
1962 Verify CRL lists when accepting client
1965 Verify CRL lists for all certificates in the
1966 client certificate chain.
1968 sslcontext= SSL session ID context identifier.
1970 generate-host-certificates[=<on|off>]
1971 Dynamically create SSL server certificates for the
1972 destination hosts of bumped SSL requests.When
1973 enabled, the cert and key options are used to sign
1974 generated certificates. Otherwise generated
1975 certificate will be selfsigned.
1976 If there is CA certificate life time of generated
1977 certificate equals lifetime of CA certificate. If
1978 generated certificate is selfsigned lifetime is three
1980 This option is enabled by default when SslBump is used.
1981 See the sslBump option above for more information.
1983 dynamic_cert_mem_cache_size=SIZE
1984 Approximate total RAM size spent on cached generated
1985 certificates. If set to zero, caching is disabled. The
1986 default value is 4MB.
1988 See http_port for a list of available options.
1996 Enables Native FTP proxy by specifying the socket address where Squid
1997 listens for FTP client requests. See http_port directive for various
1998 ways to specify the listening address and mode.
2000 Usage: ftp_port address [mode] [options]
2002 WARNING: This is a new, experimental, complex feature that has seen
2003 limited production exposure. Some Squid modules (e.g., caching) do not
2004 currently work with native FTP proxying, and many features have not
2005 even been tested for compatibility. Test well before deploying!
2007 Native FTP proxying differs substantially from proxying HTTP requests
2008 with ftp:// URIs because Squid works as an FTP server and receives
2009 actual FTP commands (rather than HTTP requests with FTP URLs).
2011 Native FTP commands accepted at ftp_port are internally converted or
2012 wrapped into HTTP-like messages. The same happens to Native FTP
2013 responses received from FTP origin servers. Those HTTP-like messages
2014 are shoveled through regular access control and adaptation layers
2015 between the FTP client and the FTP origin server. This allows Squid to
2016 examine, adapt, block, and log FTP exchanges. Squid reuses most HTTP
2017 mechanisms when shoveling wrapped FTP messages. For example,
2018 http_access and adaptation_access directives are used.
2022 intercept Same as http_port intercept. The FTP origin address is
2023 determined based on the intended destination of the
2024 intercepted connection.
2026 tproxy Support Linux TPROXY for spoofing outgoing
2027 connections using the client IP address.
2028 NP: disables authentication and maybe IPv6 on the port.
2030 By default (i.e., without an explicit mode option), Squid extracts the
2031 FTP origin address from the login@origin parameter of the FTP USER
2032 command. Many popular FTP clients support such native FTP proxying.
2036 name=token Specifies an internal name for the port. Defaults to
2037 the port address. Usable with myportname ACL.
2040 Enables tracking of FTP directories by injecting extra
2041 PWD commands and adjusting Request-URI (in wrapping
2042 HTTP requests) to reflect the current FTP server
2043 directory. Tracking is disabled by default.
2045 protocol=FTP Protocol to reconstruct accelerated and intercepted
2046 requests with. Defaults to FTP. No other accepted
2047 values have been tested with. An unsupported value
2048 results in a FATAL error. Accepted values are FTP,
2049 HTTP (or HTTP/1.1), and HTTPS (or HTTPS/1.1).
2051 Other http_port modes and options that are not specific to HTTP and
2052 HTTPS may also work.
2055 NAME: tcp_outgoing_tos tcp_outgoing_ds tcp_outgoing_dscp
2058 LOC: Ip::Qos::TheConfig.tosToServer
2060 Allows you to select a TOS/Diffserv value for packets outgoing
2061 on the server side, based on an ACL.
2063 tcp_outgoing_tos ds-field [!]aclname ...
2065 Example where normal_service_net uses the TOS value 0x00
2066 and good_service_net uses 0x20
2068 acl normal_service_net src 10.0.0.0/24
2069 acl good_service_net src 10.0.1.0/24
2070 tcp_outgoing_tos 0x00 normal_service_net
2071 tcp_outgoing_tos 0x20 good_service_net
2073 TOS/DSCP values really only have local significance - so you should
2074 know what you're specifying. For more information, see RFC2474,
2075 RFC2475, and RFC3260.
2077 The TOS/DSCP byte must be exactly that - a octet value 0 - 255, or
2078 "default" to use whatever default your host has. Note that in
2079 practice often only multiples of 4 is usable as the two rightmost bits
2080 have been redefined for use by ECN (RFC 3168 section 23.1).
2082 Processing proceeds in the order specified, and stops at first fully
2085 Only fast ACLs are supported.
2088 NAME: clientside_tos
2091 LOC: Ip::Qos::TheConfig.tosToClient
2093 Allows you to select a TOS/Diffserv value for packets being transmitted
2094 on the client-side, based on an ACL.
2096 clientside_tos ds-field [!]aclname ...
2098 Example where normal_service_net uses the TOS value 0x00
2099 and good_service_net uses 0x20
2101 acl normal_service_net src 10.0.0.0/24
2102 acl good_service_net src 10.0.1.0/24
2103 clientside_tos 0x00 normal_service_net
2104 clientside_tos 0x20 good_service_net
2106 Note: This feature is incompatible with qos_flows. Any TOS values set here
2107 will be overwritten by TOS values in qos_flows.
2110 NAME: tcp_outgoing_mark
2112 IFDEF: SO_MARK&&USE_LIBCAP
2114 LOC: Ip::Qos::TheConfig.nfmarkToServer
2116 Allows you to apply a Netfilter mark value to outgoing packets
2117 on the server side, based on an ACL.
2119 tcp_outgoing_mark mark-value [!]aclname ...
2121 Example where normal_service_net uses the mark value 0x00
2122 and good_service_net uses 0x20
2124 acl normal_service_net src 10.0.0.0/24
2125 acl good_service_net src 10.0.1.0/24
2126 tcp_outgoing_mark 0x00 normal_service_net
2127 tcp_outgoing_mark 0x20 good_service_net
2129 Only fast ACLs are supported.
2132 NAME: clientside_mark
2134 IFDEF: SO_MARK&&USE_LIBCAP
2136 LOC: Ip::Qos::TheConfig.nfmarkToClient
2138 Allows you to apply a Netfilter mark value to packets being transmitted
2139 on the client-side, based on an ACL.
2141 clientside_mark mark-value [!]aclname ...
2143 Example where normal_service_net uses the mark value 0x00
2144 and good_service_net uses 0x20
2146 acl normal_service_net src 10.0.0.0/24
2147 acl good_service_net src 10.0.1.0/24
2148 clientside_mark 0x00 normal_service_net
2149 clientside_mark 0x20 good_service_net
2151 Note: This feature is incompatible with qos_flows. Any mark values set here
2152 will be overwritten by mark values in qos_flows.
2159 LOC: Ip::Qos::TheConfig
2161 Allows you to select a TOS/DSCP value to mark outgoing
2162 connections to the client, based on where the reply was sourced.
2163 For platforms using netfilter, allows you to set a netfilter mark
2164 value instead of, or in addition to, a TOS value.
2166 By default this functionality is disabled. To enable it with the default
2167 settings simply use "qos_flows mark" or "qos_flows tos". Default
2168 settings will result in the netfilter mark or TOS value being copied
2169 from the upstream connection to the client. Note that it is the connection
2170 CONNMARK value not the packet MARK value that is copied.
2172 It is not currently possible to copy the mark or TOS value from the
2173 client to the upstream connection request.
2175 TOS values really only have local significance - so you should
2176 know what you're specifying. For more information, see RFC2474,
2177 RFC2475, and RFC3260.
2179 The TOS/DSCP byte must be exactly that - a octet value 0 - 255. Note that
2180 in practice often only multiples of 4 is usable as the two rightmost bits
2181 have been redefined for use by ECN (RFC 3168 section 23.1).
2183 Mark values can be any unsigned 32-bit integer value.
2185 This setting is configured by setting the following values:
2187 tos|mark Whether to set TOS or netfilter mark values
2189 local-hit=0xFF Value to mark local cache hits.
2191 sibling-hit=0xFF Value to mark hits from sibling peers.
2193 parent-hit=0xFF Value to mark hits from parent peers.
2195 miss=0xFF[/mask] Value to mark cache misses. Takes precedence
2196 over the preserve-miss feature (see below), unless
2197 mask is specified, in which case only the bits
2198 specified in the mask are written.
2200 The TOS variant of the following features are only possible on Linux
2201 and require your kernel to be patched with the TOS preserving ZPH
2202 patch, available from http://zph.bratcheda.org
2203 No patch is needed to preserve the netfilter mark, which will work
2204 with all variants of netfilter.
2206 disable-preserve-miss
2207 This option disables the preservation of the TOS or netfilter
2208 mark. By default, the existing TOS or netfilter mark value of
2209 the response coming from the remote server will be retained
2210 and masked with miss-mark.
2211 NOTE: in the case of a netfilter mark, the mark must be set on
2212 the connection (using the CONNMARK target) not on the packet
2216 Allows you to mask certain bits in the TOS or mark value
2217 received from the remote server, before copying the value to
2218 the TOS sent towards clients.
2219 Default for tos: 0xFF (TOS from server is not changed).
2220 Default for mark: 0xFFFFFFFF (mark from server is not changed).
2222 All of these features require the --enable-zph-qos compilation flag
2223 (enabled by default). Netfilter marking also requires the
2224 libnetfilter_conntrack libraries (--with-netfilter-conntrack) and
2225 libcap 2.09+ (--with-libcap).
2229 NAME: tcp_outgoing_address
2232 DEFAULT_DOC: Address selection is performed by the operating system.
2233 LOC: Config.accessList.outgoing_address
2235 Allows you to map requests to different outgoing IP addresses
2236 based on the username or source address of the user making
2239 tcp_outgoing_address ipaddr [[!]aclname] ...
2242 Forwarding clients with dedicated IPs for certain subnets.
2244 acl normal_service_net src 10.0.0.0/24
2245 acl good_service_net src 10.0.2.0/24
2247 tcp_outgoing_address 2001:db8::c001 good_service_net
2248 tcp_outgoing_address 10.1.0.2 good_service_net
2250 tcp_outgoing_address 2001:db8::beef normal_service_net
2251 tcp_outgoing_address 10.1.0.1 normal_service_net
2253 tcp_outgoing_address 2001:db8::1
2254 tcp_outgoing_address 10.1.0.3
2256 Processing proceeds in the order specified, and stops at first fully
2259 Squid will add an implicit IP version test to each line.
2260 Requests going to IPv4 websites will use the outgoing 10.1.0.* addresses.
2261 Requests going to IPv6 websites will use the outgoing 2001:db8:* addresses.
2264 NOTE: The use of this directive using client dependent ACLs is
2265 incompatible with the use of server side persistent connections. To
2266 ensure correct results it is best to set server_persistent_connections
2267 to off when using this directive in such configurations.
2269 NOTE: The use of this directive to set a local IP on outgoing TCP links
2270 is incompatible with using TPROXY to set client IP out outbound TCP links.
2271 When needing to contact peers use the no-tproxy cache_peer option and the
2272 client_dst_passthru directive re-enable normal forwarding such as this.
2276 NAME: host_verify_strict
2279 LOC: Config.onoff.hostStrictVerify
2281 Regardless of this option setting, when dealing with intercepted
2282 traffic, Squid always verifies that the destination IP address matches
2283 the Host header domain or IP (called 'authority form URL').
2285 This enforcement is performed to satisfy a MUST-level requirement in
2286 RFC 2616 section 14.23: "The Host field value MUST represent the naming
2287 authority of the origin server or gateway given by the original URL".
2290 Squid always responds with an HTTP 409 (Conflict) error
2291 page and logs a security warning if there is no match.
2293 Squid verifies that the destination IP address matches
2294 the Host header for forward-proxy and reverse-proxy traffic
2295 as well. For those traffic types, Squid also enables the
2296 following checks, comparing the corresponding Host header
2297 and Request-URI components:
2299 * The host names (domain or IP) must be identical,
2300 but valueless or missing Host header disables all checks.
2301 For the two host names to match, both must be either IP
2304 * Port numbers must be identical, but if a port is missing
2305 the scheme-default port is assumed.
2308 When set to OFF (the default):
2309 Squid allows suspicious requests to continue but logs a
2310 security warning and blocks caching of the response.
2312 * Forward-proxy traffic is not checked at all.
2314 * Reverse-proxy traffic is not checked at all.
2316 * Intercepted traffic which passes verification is handled
2317 according to client_dst_passthru.
2319 * Intercepted requests which fail verification are sent
2320 to the client original destination instead of DIRECT.
2321 This overrides 'client_dst_passthru off'.
2323 For now suspicious intercepted CONNECT requests are always
2324 responded to with an HTTP 409 (Conflict) error page.
2329 As described in CVE-2009-0801 when the Host: header alone is used
2330 to determine the destination of a request it becomes trivial for
2331 malicious scripts on remote websites to bypass browser same-origin
2332 security policy and sandboxing protections.
2334 The cause of this is that such applets are allowed to perform their
2335 own HTTP stack, in which case the same-origin policy of the browser
2336 sandbox only verifies that the applet tries to contact the same IP
2337 as from where it was loaded at the IP level. The Host: header may
2338 be different from the connected IP and approved origin.
2342 NAME: client_dst_passthru
2345 LOC: Config.onoff.client_dst_passthru
2347 With NAT or TPROXY intercepted traffic Squid may pass the request
2348 directly to the original client destination IP or seek a faster
2349 source using the HTTP Host header.
2351 Using Host to locate alternative servers can provide faster
2352 connectivity with a range of failure recovery options.
2353 But can also lead to connectivity trouble when the client and
2354 server are attempting stateful interactions unaware of the proxy.
2356 This option (on by default) prevents alternative DNS entries being
2357 located to send intercepted traffic DIRECT to an origin server.
2358 The clients original destination IP and port will be used instead.
2360 Regardless of this option setting, when dealing with intercepted
2361 traffic Squid will verify the Host: header and any traffic which
2362 fails Host verification will be treated as if this option were ON.
2364 see host_verify_strict for details on the verification process.
2369 -----------------------------------------------------------------------------
2372 NAME: ssl_unclean_shutdown
2376 LOC: Config.SSL.unclean_shutdown
2378 Some browsers (especially MSIE) bugs out on SSL shutdown
2385 LOC: Config.SSL.ssl_engine
2388 The OpenSSL engine to use. You will need to set this if you
2389 would like to use hardware SSL acceleration for example.
2392 NAME: sslproxy_client_certificate
2395 LOC: Config.ssl_client.cert
2398 Client SSL Certificate to use when proxying https:// URLs
2401 NAME: sslproxy_client_key
2404 LOC: Config.ssl_client.key
2407 Client SSL Key to use when proxying https:// URLs
2410 NAME: sslproxy_version
2413 DEFAULT_DOC: automatic SSL/TLS version negotiation
2414 LOC: Config.ssl_client.version
2417 SSL version level to use when proxying https:// URLs
2419 The versions of SSL/TLS supported:
2421 1 automatic (default)
2429 NAME: sslproxy_options
2432 LOC: Config.ssl_client.options
2435 SSL implementation options to use when proxying https:// URLs
2437 The most important being:
2439 NO_SSLv2 Disallow the use of SSLv2
2440 NO_SSLv3 Disallow the use of SSLv3
2441 NO_TLSv1 Disallow the use of TLSv1.0
2442 NO_TLSv1_1 Disallow the use of TLSv1.1
2443 NO_TLSv1_2 Disallow the use of TLSv1.2
2445 Always create a new key when using temporary/ephemeral
2448 Disable use of RFC5077 session tickets. Some servers
2449 may have problems understanding the TLS extension due
2450 to ambiguous specification in RFC4507.
2451 ALL Enable various bug workarounds suggested as "harmless"
2452 by OpenSSL. Be warned that this may reduce SSL/TLS
2453 strength to some attacks.
2455 See the OpenSSL SSL_CTX_set_options documentation for a
2456 complete list of possible options.
2459 NAME: sslproxy_cipher
2462 LOC: Config.ssl_client.cipher
2465 SSL cipher list to use when proxying https:// URLs
2467 Colon separated list of supported ciphers.
2470 NAME: sslproxy_cafile
2473 LOC: Config.ssl_client.cafile
2476 file containing CA certificates to use when verifying server
2477 certificates while proxying https:// URLs
2480 NAME: sslproxy_capath
2483 LOC: Config.ssl_client.capath
2486 directory containing CA certificates to use when verifying
2487 server certificates while proxying https:// URLs
2490 NAME: sslproxy_session_ttl
2493 LOC: Config.SSL.session_ttl
2496 Sets the timeout value for SSL sessions
2499 NAME: sslproxy_session_cache_size
2502 LOC: Config.SSL.sessionCacheSize
2505 Sets the cache size to use for ssl session
2508 NAME: sslproxy_cert_sign_hash
2511 LOC: Config.SSL.certSignHash
2514 Sets the hashing algorithm to use when signing generated certificates.
2515 Valid algorithm names depend on the OpenSSL library used. The following
2516 names are usually available: sha1, sha256, sha512, and md5. Please see
2517 your OpenSSL library manual for the available hashes. By default, Squids
2518 that support this option use sha256 hashes.
2520 Squid does not forcefully purge cached certificates that were generated
2521 with an algorithm other than the currently configured one. They remain
2522 in the cache, subject to the regular cache eviction policy, and become
2523 useful if the algorithm changes again.
2528 TYPE: sslproxy_ssl_bump
2529 LOC: Config.accessList.ssl_bump
2530 DEFAULT_DOC: Become a TCP tunnel without decrypting proxied traffic.
2533 This option is consulted when a CONNECT request is received on
2534 an http_port (or a new connection is intercepted at an
2535 https_port), provided that port was configured with an ssl-bump
2536 flag. The subsequent data on the connection is either treated as
2537 HTTPS and decrypted OR tunneled at TCP level without decryption,
2538 depending on the first matching bumping "action".
2540 ssl_bump <action> [!]acl ...
2542 The following bumping actions are currently supported:
2545 Become a TCP tunnel without decrypting proxied traffic.
2546 This is the default action.
2549 Establish a secure connection with the server and, using a
2550 mimicked server certificate, with the client.
2553 Receive client (step SslBump1) or server (step SslBump2)
2554 certificate while preserving the possibility of splicing the
2555 connection. Peeking at the server certificate (during step 2)
2556 usually precludes bumping of the connection at step 3.
2559 Receive client (step SslBump1) or server (step SslBump2)
2560 certificate while preserving the possibility of bumping the
2561 connection. Staring at the server certificate (during step 2)
2562 usually precludes splicing of the connection at step 3.
2565 Close client and server connections.
2567 Backward compatibility actions available at step SslBump1:
2570 Bump the connection. Establish a secure connection with the
2571 client first, then connect to the server. This old mode does
2572 not allow Squid to mimic server SSL certificate and does not
2573 work with intercepted SSL connections.
2576 Bump the connection. Establish a secure connection with the
2577 server first, then establish a secure connection with the
2578 client, using a mimicked server certificate. Works with both
2579 CONNECT requests and intercepted SSL connections, but does
2580 not allow to make decisions based on SSL handshake info.
2583 Decide whether to bump or splice the connection based on
2584 client-to-squid and server-to-squid SSL hello messages.
2588 Same as the "splice" action.
2590 All ssl_bump rules are evaluated at each of the supported bumping
2591 steps. Rules with actions that are impossible at the current step are
2592 ignored. The first matching ssl_bump action wins and is applied at the
2593 end of the current step. If no rules match, the splice action is used.
2594 See the at_step ACL for a list of the supported SslBump steps.
2596 This clause supports both fast and slow acl types.
2597 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
2599 See also: http_port ssl-bump, https_port ssl-bump, and acl at_step.
2602 # Example: Bump all requests except those originating from
2603 # localhost or those going to example.com.
2605 acl broken_sites dstdomain .example.com
2606 ssl_bump splice localhost
2607 ssl_bump splice broken_sites
2611 NAME: sslproxy_flags
2614 LOC: Config.ssl_client.flags
2617 Various flags modifying the use of SSL while proxying https:// URLs:
2618 DONT_VERIFY_PEER Accept certificates that fail verification.
2619 For refined control, see sslproxy_cert_error.
2620 NO_DEFAULT_CA Don't use the default CA list built in
2624 NAME: sslproxy_cert_error
2627 DEFAULT_DOC: Server certificate errors terminate the transaction.
2628 LOC: Config.ssl_client.cert_error
2631 Use this ACL to bypass server certificate validation errors.
2633 For example, the following lines will bypass all validation errors
2634 when talking to servers for example.com. All other
2635 validation errors will result in ERR_SECURE_CONNECT_FAIL error.
2637 acl BrokenButTrustedServers dstdomain example.com
2638 sslproxy_cert_error allow BrokenButTrustedServers
2639 sslproxy_cert_error deny all
2641 This clause only supports fast acl types.
2642 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
2643 Using slow acl types may result in server crashes
2645 Without this option, all server certificate validation errors
2646 terminate the transaction to protect Squid and the client.
2648 SQUID_X509_V_ERR_INFINITE_VALIDATION error cannot be bypassed
2649 but should not happen unless your OpenSSL library is buggy.
2652 Bypassing validation errors is dangerous because an
2653 error usually implies that the server cannot be trusted
2654 and the connection may be insecure.
2656 See also: sslproxy_flags and DONT_VERIFY_PEER.
2659 NAME: sslproxy_cert_sign
2662 POSTSCRIPTUM: signUntrusted ssl::certUntrusted
2663 POSTSCRIPTUM: signSelf ssl::certSelfSigned
2664 POSTSCRIPTUM: signTrusted all
2665 TYPE: sslproxy_cert_sign
2666 LOC: Config.ssl_client.cert_sign
2669 sslproxy_cert_sign <signing algorithm> acl ...
2671 The following certificate signing algorithms are supported:
2674 Sign using the configured CA certificate which is usually
2675 placed in and trusted by end-user browsers. This is the
2676 default for trusted origin server certificates.
2679 Sign to guarantee an X509_V_ERR_CERT_UNTRUSTED browser error.
2680 This is the default for untrusted origin server certificates
2681 that are not self-signed (see ssl::certUntrusted).
2684 Sign using a self-signed certificate with the right CN to
2685 generate a X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT error in the
2686 browser. This is the default for self-signed origin server
2687 certificates (see ssl::certSelfSigned).
2689 This clause only supports fast acl types.
2691 When sslproxy_cert_sign acl(s) match, Squid uses the corresponding
2692 signing algorithm to generate the certificate and ignores all
2693 subsequent sslproxy_cert_sign options (the first match wins). If no
2694 acl(s) match, the default signing algorithm is determined by errors
2695 detected when obtaining and validating the origin server certificate.
2697 WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can
2698 be used with sslproxy_cert_adapt, but if and only if Squid is bumping a
2699 CONNECT request that carries a domain name. In all other cases (CONNECT
2700 to an IP address or an intercepted SSL connection), Squid cannot detect
2701 the domain mismatch at certificate generation time when
2702 bump-server-first is used.
2705 NAME: sslproxy_cert_adapt
2708 TYPE: sslproxy_cert_adapt
2709 LOC: Config.ssl_client.cert_adapt
2712 sslproxy_cert_adapt <adaptation algorithm> acl ...
2714 The following certificate adaptation algorithms are supported:
2717 Sets the "Not After" property to the "Not After" property of
2718 the CA certificate used to sign generated certificates.
2721 Sets the "Not Before" property to the "Not Before" property of
2722 the CA certificate used to sign generated certificates.
2724 setCommonName or setCommonName{CN}
2725 Sets Subject.CN property to the host name specified as a
2726 CN parameter or, if no explicit CN parameter was specified,
2727 extracted from the CONNECT request. It is a misconfiguration
2728 to use setCommonName without an explicit parameter for
2729 intercepted or tproxied SSL connections.
2731 This clause only supports fast acl types.
2733 Squid first groups sslproxy_cert_adapt options by adaptation algorithm.
2734 Within a group, when sslproxy_cert_adapt acl(s) match, Squid uses the
2735 corresponding adaptation algorithm to generate the certificate and
2736 ignores all subsequent sslproxy_cert_adapt options in that algorithm's
2737 group (i.e., the first match wins within each algorithm group). If no
2738 acl(s) match, the default mimicking action takes place.
2740 WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can
2741 be used with sslproxy_cert_adapt, but if and only if Squid is bumping a
2742 CONNECT request that carries a domain name. In all other cases (CONNECT
2743 to an IP address or an intercepted SSL connection), Squid cannot detect
2744 the domain mismatch at certificate generation time when
2745 bump-server-first is used.
2748 NAME: sslpassword_program
2751 LOC: Config.Program.ssl_password
2754 Specify a program used for entering SSL key passphrases
2755 when using encrypted SSL certificate keys. If not specified
2756 keys must either be unencrypted, or Squid started with the -N
2757 option to allow it to query interactively for the passphrase.
2759 The key file name is given as argument to the program allowing
2760 selection of the right password if you have multiple encrypted
2765 OPTIONS RELATING TO EXTERNAL SSL_CRTD
2766 -----------------------------------------------------------------------------
2769 NAME: sslcrtd_program
2772 DEFAULT: @DEFAULT_SSL_CRTD@ -s @DEFAULT_SSL_DB_DIR@ -M 4MB
2773 LOC: Ssl::TheConfig.ssl_crtd
2775 Specify the location and options of the executable for ssl_crtd process.
2776 @DEFAULT_SSL_CRTD@ program requires -s and -M parameters
2777 For more information use:
2778 @DEFAULT_SSL_CRTD@ -h
2781 NAME: sslcrtd_children
2782 TYPE: HelperChildConfig
2784 DEFAULT: 32 startup=5 idle=1
2785 LOC: Ssl::TheConfig.ssl_crtdChildren
2787 The maximum number of processes spawn to service ssl server.
2788 The maximum this may be safely set to is 32.
2790 The startup= and idle= options allow some measure of skew in your
2795 Sets the minimum number of processes to spawn when Squid
2796 starts or reconfigures. When set to zero the first request will
2797 cause spawning of the first child process to handle it.
2799 Starting too few children temporary slows Squid under load while it
2800 tries to spawn enough additional processes to cope with traffic.
2804 Sets a minimum of how many processes Squid is to try and keep available
2805 at all times. When traffic begins to rise above what the existing
2806 processes can handle this many more will be spawned up to the maximum
2807 configured. A minimum setting of 1 is required.
2809 You must have at least one ssl_crtd process.
2812 NAME: sslcrtvalidator_program
2816 LOC: Ssl::TheConfig.ssl_crt_validator
2818 Specify the location and options of the executable for ssl_crt_validator
2821 Usage: sslcrtvalidator_program [ttl=n] [cache=n] path ...
2824 ttl=n TTL in seconds for cached results. The default is 60 secs
2825 cache=n limit the result cache size. The default value is 2048
2828 NAME: sslcrtvalidator_children
2829 TYPE: HelperChildConfig
2831 DEFAULT: 32 startup=5 idle=1 concurrency=1
2832 LOC: Ssl::TheConfig.ssl_crt_validator_Children
2834 The maximum number of processes spawn to service SSL server.
2835 The maximum this may be safely set to is 32.
2837 The startup= and idle= options allow some measure of skew in your
2842 Sets the minimum number of processes to spawn when Squid
2843 starts or reconfigures. When set to zero the first request will
2844 cause spawning of the first child process to handle it.
2846 Starting too few children temporary slows Squid under load while it
2847 tries to spawn enough additional processes to cope with traffic.
2851 Sets a minimum of how many processes Squid is to try and keep available
2852 at all times. When traffic begins to rise above what the existing
2853 processes can handle this many more will be spawned up to the maximum
2854 configured. A minimum setting of 1 is required.
2858 The number of requests each certificate validator helper can handle in
2859 parallel. A value of 0 indicates the certficate validator does not
2860 support concurrency. Defaults to 1.
2862 When this directive is set to a value >= 1 then the protocol
2863 used to communicate with the helper is modified to include
2864 a request ID in front of the request/response. The request
2865 ID from the request must be echoed back with the response
2868 You must have at least one ssl_crt_validator process.
2872 OPTIONS WHICH AFFECT THE NEIGHBOR SELECTION ALGORITHM
2873 -----------------------------------------------------------------------------
2881 To specify other caches in a hierarchy, use the format:
2883 cache_peer hostname type http-port icp-port [options]
2888 # hostname type port port options
2889 # -------------------- -------- ----- ----- -----------
2890 cache_peer parent.foo.net parent 3128 3130 default
2891 cache_peer sib1.foo.net sibling 3128 3130 proxy-only
2892 cache_peer sib2.foo.net sibling 3128 3130 proxy-only
2893 cache_peer example.com parent 80 0 default
2894 cache_peer cdn.example.com sibling 3128 0
2896 type: either 'parent', 'sibling', or 'multicast'.
2898 proxy-port: The port number where the peer accept HTTP requests.
2899 For other Squid proxies this is usually 3128
2900 For web servers this is usually 80
2902 icp-port: Used for querying neighbor caches about objects.
2903 Set to 0 if the peer does not support ICP or HTCP.
2904 See ICP and HTCP options below for additional details.
2907 ==== ICP OPTIONS ====
2909 You MUST also set icp_port and icp_access explicitly when using these options.
2910 The defaults will prevent peer traffic using ICP.
2913 no-query Disable ICP queries to this neighbor.
2916 Indicates the named peer is a member of a multicast group.
2917 ICP queries will not be sent directly to the peer, but ICP
2918 replies will be accepted from it.
2920 closest-only Indicates that, for ICP_OP_MISS replies, we'll only forward
2921 CLOSEST_PARENT_MISSes and never FIRST_PARENT_MISSes.
2924 To only send ICP queries to this neighbor infrequently.
2925 This is used to keep the neighbor round trip time updated
2926 and is usually used in conjunction with weighted-round-robin.
2929 ==== HTCP OPTIONS ====
2931 You MUST also set htcp_port and htcp_access explicitly when using these options.
2932 The defaults will prevent peer traffic using HTCP.
2935 htcp Send HTCP, instead of ICP, queries to the neighbor.
2936 You probably also want to set the "icp-port" to 4827
2937 instead of 3130. This directive accepts a comma separated
2938 list of options described below.
2940 htcp=oldsquid Send HTCP to old Squid versions (2.5 or earlier).
2942 htcp=no-clr Send HTCP to the neighbor but without
2943 sending any CLR requests. This cannot be used with
2946 htcp=only-clr Send HTCP to the neighbor but ONLY CLR requests.
2947 This cannot be used with no-clr.
2950 Send HTCP to the neighbor including CLRs but only when
2951 they do not result from PURGE requests.
2954 Forward any HTCP CLR requests this proxy receives to the peer.
2957 ==== PEER SELECTION METHODS ====
2959 The default peer selection method is ICP, with the first responding peer
2960 being used as source. These options can be used for better load balancing.
2963 default This is a parent cache which can be used as a "last-resort"
2964 if a peer cannot be located by any of the peer-selection methods.
2965 If specified more than once, only the first is used.
2967 round-robin Load-Balance parents which should be used in a round-robin
2968 fashion in the absence of any ICP queries.
2969 weight=N can be used to add bias.
2971 weighted-round-robin
2972 Load-Balance parents which should be used in a round-robin
2973 fashion with the frequency of each parent being based on the
2974 round trip time. Closer parents are used more often.
2975 Usually used for background-ping parents.
2976 weight=N can be used to add bias.
2978 carp Load-Balance parents which should be used as a CARP array.
2979 The requests will be distributed among the parents based on the
2980 CARP load balancing hash function based on their weight.
2982 userhash Load-balance parents based on the client proxy_auth or ident username.
2984 sourcehash Load-balance parents based on the client source IP.
2987 To be used only for cache peers of type "multicast".
2988 ALL members of this multicast group have "sibling"
2989 relationship with it, not "parent". This is to a multicast
2990 group when the requested object would be fetched only from
2991 a "parent" cache, anyway. It's useful, e.g., when
2992 configuring a pool of redundant Squid proxies, being
2993 members of the same multicast group.
2996 ==== PEER SELECTION OPTIONS ====
2998 weight=N use to affect the selection of a peer during any weighted
2999 peer-selection mechanisms.
3000 The weight must be an integer; default is 1,
3001 larger weights are favored more.
3002 This option does not affect parent selection if a peering
3003 protocol is not in use.
3005 basetime=N Specify a base amount to be subtracted from round trip
3007 It is subtracted before division by weight in calculating
3008 which parent to fectch from. If the rtt is less than the
3009 base time the rtt is set to a minimal value.
3011 ttl=N Specify a TTL to use when sending multicast ICP queries
3013 Only useful when sending to a multicast group.
3014 Because we don't accept ICP replies from random
3015 hosts, you must configure other group members as
3016 peers with the 'multicast-responder' option.
3018 no-delay To prevent access to this neighbor from influencing the
3021 digest-url=URL Tell Squid to fetch the cache digest (if digests are
3022 enabled) for this host from the specified URL rather
3023 than the Squid default location.
3026 ==== CARP OPTIONS ====
3028 carp-key=key-specification
3029 use a different key than the full URL to hash against the peer.
3030 the key-specification is a comma-separated list of the keywords
3031 scheme, host, port, path, params
3032 Order is not important.
3034 ==== ACCELERATOR / REVERSE-PROXY OPTIONS ====
3036 originserver Causes this parent to be contacted as an origin server.
3037 Meant to be used in accelerator setups when the peer
3041 Set the Host header of requests forwarded to this peer.
3042 Useful in accelerator setups where the server (peer)
3043 expects a certain domain name but clients may request
3044 others. ie example.com or www.example.com
3046 no-digest Disable request of cache digests.
3049 Disables requesting ICMP RTT database (NetDB).
3052 ==== AUTHENTICATION OPTIONS ====
3055 If this is a personal/workgroup proxy and your parent
3056 requires proxy authentication.
3058 Note: The string can include URL escapes (i.e. %20 for
3059 spaces). This also means % must be written as %%.
3062 Send login details received from client to this peer.
3063 Both Proxy- and WWW-Authorization headers are passed
3064 without alteration to the peer.
3065 Authentication is not required by Squid for this to work.
3067 Note: This will pass any form of authentication but
3068 only Basic auth will work through a proxy unless the
3069 connection-auth options are also used.
3071 login=PASS Send login details received from client to this peer.
3072 Authentication is not required by this option.
3074 If there are no client-provided authentication headers
3075 to pass on, but username and password are available
3076 from an external ACL user= and password= result tags
3077 they may be sent instead.
3079 Note: To combine this with proxy_auth both proxies must
3080 share the same user database as HTTP only allows for
3081 a single login (one for proxy, one for origin server).
3082 Also be warned this will expose your users proxy
3083 password to the peer. USE WITH CAUTION
3086 Send the username to the upstream cache, but with a
3087 fixed password. This is meant to be used when the peer
3088 is in another administrative domain, but it is still
3089 needed to identify each user.
3090 The star can optionally be followed by some extra
3091 information which is added to the username. This can
3092 be used to identify this proxy to the peer, similar to
3093 the login=username:password option above.
3096 If this is a personal/workgroup proxy and your parent
3097 requires a secure proxy authentication.
3098 The first principal from the default keytab or defined by
3099 the environment variable KRB5_KTNAME will be used.
3101 WARNING: The connection may transmit requests from multiple
3102 clients. Negotiate often assumes end-to-end authentication
3103 and a single-client. Which is not strictly true here.
3105 login=NEGOTIATE:principal_name
3106 If this is a personal/workgroup proxy and your parent
3107 requires a secure proxy authentication.
3108 The principal principal_name from the default keytab or
3109 defined by the environment variable KRB5_KTNAME will be
3112 WARNING: The connection may transmit requests from multiple
3113 clients. Negotiate often assumes end-to-end authentication
3114 and a single-client. Which is not strictly true here.
3116 connection-auth=on|off
3117 Tell Squid that this peer does or not support Microsoft
3118 connection oriented authentication, and any such
3119 challenges received from there should be ignored.
3120 Default is auto to automatically determine the status
3124 ==== SSL / HTTPS / TLS OPTIONS ====
3126 ssl Encrypt connections to this peer with SSL/TLS.
3128 sslcert=/path/to/ssl/certificate
3129 A client SSL certificate to use when connecting to
3132 sslkey=/path/to/ssl/key
3133 The private SSL key corresponding to sslcert above.
3134 If 'sslkey' is not specified 'sslcert' is assumed to
3135 reference a combined file containing both the
3136 certificate and the key.
3138 sslversion=1|2|3|4|5|6
3139 The SSL version to use when connecting to this peer
3140 1 = automatic (default)
3147 sslcipher=... The list of valid SSL ciphers to use when connecting
3150 ssloptions=... Specify various SSL implementation options:
3152 NO_SSLv2 Disallow the use of SSLv2
3153 NO_SSLv3 Disallow the use of SSLv3
3154 NO_TLSv1 Disallow the use of TLSv1.0
3155 NO_TLSv1_1 Disallow the use of TLSv1.1
3156 NO_TLSv1_2 Disallow the use of TLSv1.2
3158 Always create a new key when using
3159 temporary/ephemeral DH key exchanges
3160 ALL Enable various bug workarounds
3161 suggested as "harmless" by OpenSSL
3162 Be warned that this reduces SSL/TLS
3163 strength to some attacks.
3165 See the OpenSSL SSL_CTX_set_options documentation for a
3168 sslcafile=... A file containing additional CA certificates to use
3169 when verifying the peer certificate.
3171 sslcapath=... A directory containing additional CA certificates to
3172 use when verifying the peer certificate.
3174 sslcrlfile=... A certificate revocation list file to use when
3175 verifying the peer certificate.
3177 sslflags=... Specify various flags modifying the SSL implementation:
3180 Accept certificates even if they fail to
3183 Don't use the default CA list built in
3186 Don't verify the peer certificate
3187 matches the server name
3189 ssldomain= The peer name as advertised in it's certificate.
3190 Used for verifying the correctness of the received peer
3191 certificate. If not specified the peer hostname will be
3195 Enable the "Front-End-Https: On" header needed when
3196 using Squid as a SSL frontend in front of Microsoft OWA.
3197 See MS KB document Q307347 for details on this header.
3198 If set to auto the header will only be added if the
3199 request is forwarded as a https:// URL.
3202 ==== GENERAL OPTIONS ====
3205 A peer-specific connect timeout.
3206 Also see the peer_connect_timeout directive.
3208 connect-fail-limit=N
3209 How many times connecting to a peer must fail before
3210 it is marked as down. Standby connection failures
3211 count towards this limit. Default is 10.
3213 allow-miss Disable Squid's use of only-if-cached when forwarding
3214 requests to siblings. This is primarily useful when
3215 icp_hit_stale is used by the sibling. To extensive use
3216 of this option may result in forwarding loops, and you
3217 should avoid having two-way peerings with this option.
3218 For example to deny peer usage on requests from peer
3219 by denying cache_peer_access if the source is a peer.
3221 max-conn=N Limit the number of concurrent connections the Squid
3222 may open to this peer, including already opened idle
3223 and standby connections. There is no peer-specific
3224 connection limit by default.
3226 A peer exceeding the limit is not used for new
3227 requests unless a standby connection is available.
3229 max-conn currently works poorly with idle persistent
3230 connections: When a peer reaches its max-conn limit,
3231 and there are idle persistent connections to the peer,
3232 the peer may not be selected because the limiting code
3233 does not know whether Squid can reuse those idle
3236 standby=N Maintain a pool of N "hot standby" connections to an
3237 UP peer, available for requests when no idle
3238 persistent connection is available (or safe) to use.
3239 By default and with zero N, no such pool is maintained.
3240 N must not exceed the max-conn limit (if any).
3242 At start or after reconfiguration, Squid opens new TCP
3243 standby connections until there are N connections
3244 available and then replenishes the standby pool as
3245 opened connections are used up for requests. A used
3246 connection never goes back to the standby pool, but
3247 may go to the regular idle persistent connection pool
3248 shared by all peers and origin servers.
3250 Squid never opens multiple new standby connections
3251 concurrently. This one-at-a-time approach minimizes
3252 flooding-like effect on peers. Furthermore, just a few
3253 standby connections should be sufficient in most cases
3254 to supply most new requests with a ready-to-use
3257 Standby connections obey server_idle_pconn_timeout.
3258 For the feature to work as intended, the peer must be
3259 configured to accept and keep them open longer than
3260 the idle timeout at the connecting Squid, to minimize
3261 race conditions typical to idle used persistent
3262 connections. Default request_timeout and
3263 server_idle_pconn_timeout values ensure such a
3266 name=xxx Unique name for the peer.
3267 Required if you have multiple peers on the same host
3268 but different ports.
3269 This name can be used in cache_peer_access and similar
3270 directives to dentify the peer.
3271 Can be used by outgoing access controls through the
3274 no-tproxy Do not use the client-spoof TPROXY support when forwarding
3275 requests to this peer. Use normal address selection instead.
3276 This overrides the spoof_client_ip ACL.
3278 proxy-only objects fetched from the peer will not be stored locally.
3282 NAME: cache_peer_domain cache_host_domain
3287 Use to limit the domains for which a neighbor cache will be
3291 cache_peer_domain cache-host domain [domain ...]
3292 cache_peer_domain cache-host !domain
3294 For example, specifying
3296 cache_peer_domain parent.foo.net .edu
3298 has the effect such that UDP query packets are sent to
3299 'bigserver' only when the requested object exists on a
3300 server in the .edu domain. Prefixing the domainname
3301 with '!' means the cache will be queried for objects
3304 NOTE: * Any number of domains may be given for a cache-host,
3305 either on the same or separate lines.
3306 * When multiple domains are given for a particular
3307 cache-host, the first matched domain is applied.
3308 * Cache hosts with no domain restrictions are queried
3310 * There are no defaults.
3311 * There is also a 'cache_peer_access' tag in the ACL
3315 NAME: cache_peer_access
3320 Similar to 'cache_peer_domain' but provides more flexibility by
3324 cache_peer_access cache-host allow|deny [!]aclname ...
3326 The syntax is identical to 'http_access' and the other lists of
3327 ACL elements. See the comments for 'http_access' below, or
3328 the Squid FAQ (http://wiki.squid-cache.org/SquidFaq/SquidAcl).
3331 NAME: neighbor_type_domain
3332 TYPE: hostdomaintype
3334 DEFAULT_DOC: The peer type from cache_peer directive is used for all requests to that peer.
3337 Modify the cache_peer neighbor type when passing requests
3338 about specific domains to the peer.
3341 neighbor_type_domain neighbor parent|sibling domain domain ...
3344 cache_peer foo.example.com parent 3128 3130
3345 neighbor_type_domain foo.example.com sibling .au .de
3347 The above configuration treats all requests to foo.example.com as a
3348 parent proxy unless the request is for a .au or .de ccTLD domain name.
3351 NAME: dead_peer_timeout
3355 LOC: Config.Timeout.deadPeer
3357 This controls how long Squid waits to declare a peer cache
3358 as "dead." If there are no ICP replies received in this
3359 amount of time, Squid will declare the peer dead and not
3360 expect to receive any further ICP replies. However, it
3361 continues to send ICP queries, and will mark the peer as
3362 alive upon receipt of the first subsequent ICP reply.
3364 This timeout also affects when Squid expects to receive ICP
3365 replies from peers. If more than 'dead_peer' seconds have
3366 passed since the last ICP reply was received, Squid will not
3367 expect to receive an ICP reply on the next query. Thus, if
3368 your time between requests is greater than this timeout, you
3369 will see a lot of requests sent DIRECT to origin servers
3370 instead of to your parents.
3373 NAME: forward_max_tries
3376 LOC: Config.forward_max_tries
3378 Controls how many different forward paths Squid will try
3379 before giving up. See also forward_timeout.
3381 NOTE: connect_retries (default: none) can make each of these
3382 possible forwarding paths be tried multiple times.
3386 MEMORY CACHE OPTIONS
3387 -----------------------------------------------------------------------------
3394 LOC: Config.memMaxSize
3396 NOTE: THIS PARAMETER DOES NOT SPECIFY THE MAXIMUM PROCESS SIZE.
3397 IT ONLY PLACES A LIMIT ON HOW MUCH ADDITIONAL MEMORY SQUID WILL
3398 USE AS A MEMORY CACHE OF OBJECTS. SQUID USES MEMORY FOR OTHER
3399 THINGS AS WELL. SEE THE SQUID FAQ SECTION 8 FOR DETAILS.
3401 'cache_mem' specifies the ideal amount of memory to be used
3403 * In-Transit objects
3405 * Negative-Cached objects
3407 Data for these objects are stored in 4 KB blocks. This
3408 parameter specifies the ideal upper limit on the total size of
3409 4 KB blocks allocated. In-Transit objects take the highest
3412 In-transit objects have priority over the others. When
3413 additional space is needed for incoming data, negative-cached
3414 and hot objects will be released. In other words, the
3415 negative-cached and hot objects will fill up any unused space
3416 not needed for in-transit objects.
3418 If circumstances require, this limit will be exceeded.
3419 Specifically, if your incoming request rate requires more than
3420 'cache_mem' of memory to hold in-transit objects, Squid will
3421 exceed this limit to satisfy the new requests. When the load
3422 decreases, blocks will be freed until the high-water mark is
3423 reached. Thereafter, blocks will be used to store hot
3426 If shared memory caching is enabled, Squid does not use the shared
3427 cache space for in-transit objects, but they still consume as much
3428 local memory as they need. For more details about the shared memory
3429 cache, see memory_cache_shared.
3432 NAME: maximum_object_size_in_memory
3436 LOC: Config.Store.maxInMemObjSize
3438 Objects greater than this size will not be attempted to kept in
3439 the memory cache. This should be set high enough to keep objects
3440 accessed frequently in memory to improve performance whilst low
3441 enough to keep larger objects from hoarding cache_mem.
3444 NAME: memory_cache_shared
3447 LOC: Config.memShared
3449 DEFAULT_DOC: "on" where supported if doing memory caching with multiple SMP workers.
3451 Controls whether the memory cache is shared among SMP workers.
3453 The shared memory cache is meant to occupy cache_mem bytes and replace
3454 the non-shared memory cache, although some entities may still be
3455 cached locally by workers for now (e.g., internal and in-transit
3456 objects may be served from a local memory cache even if shared memory
3457 caching is enabled).
3459 By default, the memory cache is shared if and only if all of the
3460 following conditions are satisfied: Squid runs in SMP mode with
3461 multiple workers, cache_mem is positive, and Squid environment
3462 supports required IPC primitives (e.g., POSIX shared memory segments
3463 and GCC-style atomic operations).
3465 To avoid blocking locks, shared memory uses opportunistic algorithms
3466 that do not guarantee that every cachable entity that could have been
3467 shared among SMP workers will actually be shared.
3469 Currently, entities exceeding 32KB in size cannot be shared.
3472 NAME: memory_cache_mode
3476 DEFAULT_DOC: Keep the most recently fetched objects in memory
3478 Controls which objects to keep in the memory cache (cache_mem)
3480 always Keep most recently fetched objects in memory (default)
3482 disk Only disk cache hits are kept in memory, which means
3483 an object must first be cached on disk and then hit
3484 a second time before cached in memory.
3486 network Only objects fetched from network is kept in memory
3489 NAME: memory_replacement_policy
3491 LOC: Config.memPolicy
3494 The memory replacement policy parameter determines which
3495 objects are purged from memory when memory space is needed.
3497 See cache_replacement_policy for details on algorithms.
3502 -----------------------------------------------------------------------------
3505 NAME: cache_replacement_policy
3507 LOC: Config.replPolicy
3510 The cache replacement policy parameter determines which
3511 objects are evicted (replaced) when disk space is needed.
3513 lru : Squid's original list based LRU policy
3514 heap GDSF : Greedy-Dual Size Frequency
3515 heap LFUDA: Least Frequently Used with Dynamic Aging
3516 heap LRU : LRU policy implemented using a heap
3518 Applies to any cache_dir lines listed below this directive.
3520 The LRU policies keeps recently referenced objects.
3522 The heap GDSF policy optimizes object hit rate by keeping smaller
3523 popular objects in cache so it has a better chance of getting a
3524 hit. It achieves a lower byte hit rate than LFUDA though since
3525 it evicts larger (possibly popular) objects.
3527 The heap LFUDA policy keeps popular objects in cache regardless of
3528 their size and thus optimizes byte hit rate at the expense of
3529 hit rate since one large, popular object will prevent many
3530 smaller, slightly less popular objects from being cached.
3532 Both policies utilize a dynamic aging mechanism that prevents
3533 cache pollution that can otherwise occur with frequency-based
3534 replacement policies.
3536 NOTE: if using the LFUDA replacement policy you should increase
3537 the value of maximum_object_size above its default of 4 MB to
3538 to maximize the potential byte hit rate improvement of LFUDA.
3540 For more information about the GDSF and LFUDA cache replacement
3541 policies see http://www.hpl.hp.com/techreports/1999/HPL-1999-69.html
3542 and http://fog.hpl.external.hp.com/techreports/98/HPL-98-173.html.
3545 NAME: minimum_object_size
3549 DEFAULT_DOC: no limit
3550 LOC: Config.Store.minObjectSize
3552 Objects smaller than this size will NOT be saved on disk. The
3553 value is specified in bytes, and the default is 0 KB, which
3554 means all responses can be stored.
3557 NAME: maximum_object_size
3561 LOC: Config.Store.maxObjectSize
3563 Set the default value for max-size parameter on any cache_dir.
3564 The value is specified in bytes, and the default is 4 MB.
3566 If you wish to get a high BYTES hit ratio, you should probably
3567 increase this (one 32 MB object hit counts for 3200 10KB
3570 If you wish to increase hit ratio more than you want to
3571 save bandwidth you should leave this low.
3573 NOTE: if using the LFUDA replacement policy you should increase
3574 this value to maximize the byte hit rate improvement of LFUDA!
3575 See cache_replacement_policy for a discussion of this policy.
3581 DEFAULT_DOC: No disk cache. Store cache ojects only in memory.
3582 LOC: Config.cacheSwap
3585 cache_dir Type Directory-Name Fs-specific-data [options]
3587 You can specify multiple cache_dir lines to spread the
3588 cache among different disk partitions.
3590 Type specifies the kind of storage system to use. Only "ufs"
3591 is built by default. To enable any of the other storage systems
3592 see the --enable-storeio configure option.
3594 'Directory' is a top-level directory where cache swap
3595 files will be stored. If you want to use an entire disk
3596 for caching, this can be the mount-point directory.
3597 The directory must exist and be writable by the Squid
3598 process. Squid will NOT create this directory for you.
3600 In SMP configurations, cache_dir must not precede the workers option
3601 and should use configuration macros or conditionals to give each
3602 worker interested in disk caching a dedicated cache directory.
3605 ==== The ufs store type ====
3607 "ufs" is the old well-known Squid storage format that has always
3611 cache_dir ufs Directory-Name Mbytes L1 L2 [options]
3613 'Mbytes' is the amount of disk space (MB) to use under this
3614 directory. The default is 100 MB. Change this to suit your
3615 configuration. Do NOT put the size of your disk drive here.
3616 Instead, if you want Squid to use the entire disk drive,
3617 subtract 20% and use that value.
3619 'L1' is the number of first-level subdirectories which
3620 will be created under the 'Directory'. The default is 16.
3622 'L2' is the number of second-level subdirectories which
3623 will be created under each first-level directory. The default
3627 ==== The aufs store type ====
3629 "aufs" uses the same storage format as "ufs", utilizing
3630 POSIX-threads to avoid blocking the main Squid process on
3631 disk-I/O. This was formerly known in Squid as async-io.
3634 cache_dir aufs Directory-Name Mbytes L1 L2 [options]
3636 see argument descriptions under ufs above
3639 ==== The diskd store type ====
3641 "diskd" uses the same storage format as "ufs", utilizing a
3642 separate process to avoid blocking the main Squid process on
3646 cache_dir diskd Directory-Name Mbytes L1 L2 [options] [Q1=n] [Q2=n]
3648 see argument descriptions under ufs above
3650 Q1 specifies the number of unacknowledged I/O requests when Squid
3651 stops opening new files. If this many messages are in the queues,
3652 Squid won't open new files. Default is 64
3654 Q2 specifies the number of unacknowledged messages when Squid
3655 starts blocking. If this many messages are in the queues,
3656 Squid blocks until it receives some replies. Default is 72
3658 When Q1 < Q2 (the default), the cache directory is optimized
3659 for lower response time at the expense of a decrease in hit
3660 ratio. If Q1 > Q2, the cache directory is optimized for
3661 higher hit ratio at the expense of an increase in response
3665 ==== The rock store type ====
3668 cache_dir rock Directory-Name Mbytes [options]
3670 The Rock Store type is a database-style storage. All cached
3671 entries are stored in a "database" file, using fixed-size slots.
3672 A single entry occupies one or more slots.
3674 If possible, Squid using Rock Store creates a dedicated kid
3675 process called "disker" to avoid blocking Squid worker(s) on disk
3676 I/O. One disker kid is created for each rock cache_dir. Diskers
3677 are created only when Squid, running in daemon mode, has support
3678 for the IpcIo disk I/O module.
3680 swap-timeout=msec: Squid will not start writing a miss to or
3681 reading a hit from disk if it estimates that the swap operation
3682 will take more than the specified number of milliseconds. By
3683 default and when set to zero, disables the disk I/O time limit
3684 enforcement. Ignored when using blocking I/O module because
3685 blocking synchronous I/O does not allow Squid to estimate the
3686 expected swap wait time.
3688 max-swap-rate=swaps/sec: Artificially limits disk access using
3689 the specified I/O rate limit. Swap out requests that
3690 would cause the average I/O rate to exceed the limit are
3691 delayed. Individual swap in requests (i.e., hits or reads) are
3692 not delayed, but they do contribute to measured swap rate and
3693 since they are placed in the same FIFO queue as swap out
3694 requests, they may wait longer if max-swap-rate is smaller.
3695 This is necessary on file systems that buffer "too
3696 many" writes and then start blocking Squid and other processes
3697 while committing those writes to disk. Usually used together
3698 with swap-timeout to avoid excessive delays and queue overflows
3699 when disk demand exceeds available disk "bandwidth". By default
3700 and when set to zero, disables the disk I/O rate limit
3701 enforcement. Currently supported by IpcIo module only.
3703 slot-size=bytes: The size of a database "record" used for
3704 storing cached responses. A cached response occupies at least
3705 one slot and all database I/O is done using individual slots so
3706 increasing this parameter leads to more disk space waste while
3707 decreasing it leads to more disk I/O overheads. Should be a
3708 multiple of your operating system I/O page size. Defaults to
3709 16KBytes. A housekeeping header is stored with each slot and
3710 smaller slot-sizes will be rejected. The header is smaller than
3714 ==== COMMON OPTIONS ====
3716 no-store no new objects should be stored to this cache_dir.
3718 min-size=n the minimum object size in bytes this cache_dir
3719 will accept. It's used to restrict a cache_dir
3720 to only store large objects (e.g. AUFS) while
3721 other stores are optimized for smaller objects
3725 max-size=n the maximum object size in bytes this cache_dir
3727 The value in maximum_object_size directive sets
3728 the default unless more specific details are
3729 available (ie a small store capacity).
3731 Note: To make optimal use of the max-size limits you should order
3732 the cache_dir lines with the smallest max-size value first.
3736 # Uncomment and adjust the following to add a disk cache directory.
3737 #cache_dir ufs @DEFAULT_SWAP_DIR@ 100 16 256
3741 NAME: store_dir_select_algorithm
3743 LOC: Config.store_dir_select_algorithm
3746 How Squid selects which cache_dir to use when the response
3747 object will fit into more than one.
3749 Regardless of which algorithm is used the cache_dir min-size
3750 and max-size parameters are obeyed. As such they can affect
3751 the selection algorithm by limiting the set of considered
3758 This algorithm is suited to caches with similar cache_dir
3759 sizes and disk speeds.
3761 The disk with the least I/O pending is selected.
3762 When there are multiple disks with the same I/O load ranking
3763 the cache_dir with most available capacity is selected.
3765 When a mix of cache_dir sizes are configured the faster disks
3766 have a naturally lower I/O loading and larger disks have more
3767 capacity. So space used to store objects and data throughput
3768 may be very unbalanced towards larger disks.
3773 This algorithm is suited to caches with unequal cache_dir
3776 Each cache_dir is selected in a rotation. The next suitable
3779 Available cache_dir capacity is only considered in relation
3780 to whether the object will fit and meets the min-size and
3781 max-size parameters.
3783 Disk I/O loading is only considered to prevent overload on slow
3784 disks. This algorithm does not spread objects by size, so any
3785 I/O loading per-disk may appear very unbalanced and volatile.
3787 If several cache_dirs use similar min-size, max-size, or other
3788 limits to to reject certain responses, then do not group such
3789 cache_dir lines together, to avoid round-robin selection bias
3790 towards the first cache_dir after the group. Instead, interleave
3791 cache_dir lines from different groups. For example:
3793 store_dir_select_algorithm round-robin
3794 cache_dir rock /hdd1 ... min-size=100000
3795 cache_dir rock /ssd1 ... max-size=99999
3796 cache_dir rock /hdd2 ... min-size=100000
3797 cache_dir rock /ssd2 ... max-size=99999
3798 cache_dir rock /hdd3 ... min-size=100000
3799 cache_dir rock /ssd3 ... max-size=99999
3802 NAME: max_open_disk_fds
3804 LOC: Config.max_open_disk_fds
3806 DEFAULT_DOC: no limit
3808 To avoid having disk as the I/O bottleneck Squid can optionally
3809 bypass the on-disk cache if more than this amount of disk file
3810 descriptors are open.
3812 A value of 0 indicates no limit.
3815 NAME: cache_swap_low
3816 COMMENT: (percent, 0-100)
3819 LOC: Config.Swap.lowWaterMark
3821 The low-water mark for cache object replacement.
3822 Replacement begins when the swap (disk) usage is above the
3823 low-water mark and attempts to maintain utilization near the
3824 low-water mark. As swap utilization gets close to high-water
3825 mark object eviction becomes more aggressive. If utilization is
3826 close to the low-water mark less replacement is done each time.
3828 Defaults are 90% and 95%. If you have a large cache, 5% could be
3829 hundreds of MB. If this is the case you may wish to set these
3830 numbers closer together.
3832 See also cache_swap_high
3835 NAME: cache_swap_high
3836 COMMENT: (percent, 0-100)
3839 LOC: Config.Swap.highWaterMark
3841 The high-water mark for cache object replacement.
3842 Replacement begins when the swap (disk) usage is above the
3843 low-water mark and attempts to maintain utilization near the
3844 low-water mark. As swap utilization gets close to high-water
3845 mark object eviction becomes more aggressive. If utilization is
3846 close to the low-water mark less replacement is done each time.
3848 Defaults are 90% and 95%. If you have a large cache, 5% could be
3849 hundreds of MB. If this is the case you may wish to set these
3850 numbers closer together.
3852 See also cache_swap_low
3857 -----------------------------------------------------------------------------
3864 DEFAULT_DOC: The format definitions squid, common, combined, referrer, useragent are built in.
3868 logformat <name> <format specification>
3870 Defines an access log format.
3872 The <format specification> is a string with embedded % format codes
3874 % format codes all follow the same basic structure where all but
3875 the formatcode is optional. Output strings are automatically escaped
3876 as required according to their context and the output format
3877 modifiers are usually not needed, but can be specified if an explicit
3878 output format is desired.
3880 % ["|[|'|#] [-] [[0]width] [{argument}] formatcode
3882 " output in quoted string format
3883 [ output in squid text log format as used by log_mime_hdrs
3884 # output in URL quoted format
3889 width minimum and/or maximum field width:
3890 [width_min][.width_max]
3891 When minimum starts with 0, the field is zero-padded.
3892 String values exceeding maximum width are truncated.
3894 {arg} argument such as header name etc
3898 % a literal % character
3899 sn Unique sequence number per log line entry
3900 err_code The ID of an error response served by Squid or
3901 a similar internal error identifier.
3902 err_detail Additional err_code-dependent error information.
3903 note The annotation specified by the argument. Also
3904 logs the adaptation meta headers set by the
3905 adaptation_meta configuration parameter.
3906 If no argument given all annotations logged.
3907 The argument may include a separator to use with
3910 By default, multiple note values are separated with ","
3911 and multiple notes are separated with "\r\n".
3912 When logging named notes with %{name}note, the
3913 explicitly configured separator is used between note
3914 values. When logging all notes with %note, the
3915 explicitly configured separator is used between
3916 individual notes. There is currently no way to
3917 specify both value and notes separators when logging
3918 all notes with %note.
3920 Connection related format codes:
3922 >a Client source IP address
3924 >p Client source port
3925 >eui Client source EUI (MAC address, EUI-48 or EUI-64 identifier)
3926 >la Local IP address the client connected to
3927 >lp Local port number the client connected to
3928 >qos Client connection TOS/DSCP value set by Squid
3929 >nfmark Client connection netfilter mark set by Squid
3931 la Local listening IP address the client connection was connected to.
3932 lp Local listening port number the client connection was connected to.
3934 <a Server IP address of the last server or peer connection
3935 <A Server FQDN or peer name
3936 <p Server port number of the last server or peer connection
3937 <la Local IP address of the last server or peer connection
3938 <lp Local port number of the last server or peer connection
3939 <qos Server connection TOS/DSCP value set by Squid
3940 <nfmark Server connection netfilter mark set by Squid
3942 Time related format codes:
3944 ts Seconds since epoch
3945 tu subsecond time (milliseconds)
3946 tl Local time. Optional strftime format argument
3947 default %d/%b/%Y:%H:%M:%S %z
3948 tg GMT time. Optional strftime format argument
3949 default %d/%b/%Y:%H:%M:%S %z
3950 tr Response time (milliseconds)
3951 dt Total time spent making DNS lookups (milliseconds)
3952 tS Approximate master transaction start time in
3953 <full seconds since epoch>.<fractional seconds> format.
3954 Currently, Squid considers the master transaction
3955 started when a complete HTTP request header initiating
3956 the transaction is received from the client. This is
3957 the same value that Squid uses to calculate transaction
3958 response time when logging %tr to access.log. Currently,
3959 Squid uses millisecond resolution for %tS values,
3960 similar to the default access.log "current time" field
3963 Access Control related format codes:
3965 et Tag returned by external acl
3966 ea Log string returned by external acl
3967 un User name (any available)
3968 ul User name from authentication
3969 ue User name from external acl helper
3970 ui User name from ident
3971 us User name from SSL
3972 credentials Client credentials. The exact meaning depends on
3973 the authentication scheme: For Basic authentication,
3974 it is the password; for Digest, the realm sent by the
3975 client; for NTLM and Negotiate, the client challenge
3976 or client credentials prefixed with "YR " or "KK ".
3978 HTTP related format codes:
3982 [http::]rm Request method (GET/POST etc)
3983 [http::]>rm Request method from client
3984 [http::]<rm Request method sent to server or peer
3985 [http::]ru Request URL from client (historic, filtered for logging)
3986 [http::]>ru Request URL from client
3987 [http::]<ru Request URL sent to server or peer
3988 [http::]>rs Request URL scheme from client
3989 [http::]<rs Request URL scheme sent to server or peer
3990 [http::]>rd Request URL domain from client
3991 [http::]<rd Request URL domain sent to server or peer
3992 [http::]>rP Request URL port from client
3993 [http::]<rP Request URL port sent to server or peer
3994 [http::]rp Request URL path excluding hostname
3995 [http::]>rp Request URL path excluding hostname from client
3996 [http::]<rp Request URL path excluding hostname sent to server or peer
3997 [http::]rv Request protocol version
3998 [http::]>rv Request protocol version from client
3999 [http::]<rv Request protocol version sent to server or peer
4001 [http::]>h Original received request header.
4002 Usually differs from the request header sent by
4003 Squid, although most fields are often preserved.
4004 Accepts optional header field name/value filter
4005 argument using name[:[separator]element] format.
4006 [http::]>ha Received request header after adaptation and
4007 redirection (pre-cache REQMOD vectoring point).
4008 Usually differs from the request header sent by
4009 Squid, although most fields are often preserved.
4010 Optional header name argument as for >h
4015 [http::]<Hs HTTP status code received from the next hop
4016 [http::]>Hs HTTP status code sent to the client
4018 [http::]<h Reply header. Optional header name argument
4021 [http::]mt MIME content type
4026 [http::]st Total size of request + reply traffic with client
4027 [http::]>st Total size of request received from client.
4028 Excluding chunked encoding bytes.
4029 [http::]<st Total size of reply sent to client (after adaptation)
4031 [http::]>sh Size of request headers received from client
4032 [http::]<sh Size of reply headers sent to client (after adaptation)
4034 [http::]<sH Reply high offset sent
4035 [http::]<sS Upstream object size
4037 [http::]<bs Number of HTTP-equivalent message body bytes
4038 received from the next hop, excluding chunked
4039 transfer encoding and control messages.
4040 Generated FTP/Gopher listings are treated as
4046 [http::]<pt Peer response time in milliseconds. The timer starts
4047 when the last request byte is sent to the next hop
4048 and stops when the last response byte is received.
4049 [http::]<tt Total time in milliseconds. The timer
4050 starts with the first connect request (or write I/O)
4051 sent to the first selected peer. The timer stops
4052 with the last I/O with the last peer.
4054 Squid handling related format codes:
4056 Ss Squid request status (TCP_MISS etc)
4057 Sh Squid hierarchy status (DEFAULT_PARENT etc)
4059 SSL-related format codes:
4061 ssl::bump_mode SslBump decision for the transaction:
4063 For CONNECT requests that initiated bumping of
4064 a connection and for any request received on
4065 an already bumped connection, Squid logs the
4066 corresponding SslBump mode ("server-first" or
4067 "client-first"). See the ssl_bump option for
4068 more information about these modes.
4070 A "none" token is logged for requests that
4071 triggered "ssl_bump" ACL evaluation matching
4072 either a "none" rule or no rules at all.
4074 In all other cases, a single dash ("-") is
4077 ssl::>sni SSL client SNI sent to Squid. Available only
4078 after the peek, stare, or splice SSL bumping
4081 If ICAP is enabled, the following code becomes available (as
4082 well as ICAP log codes documented with the icap_log option):
4084 icap::tt Total ICAP processing time for the HTTP
4085 transaction. The timer ticks when ICAP
4086 ACLs are checked and when ICAP
4087 transaction is in progress.
4089 If adaptation is enabled the following three codes become available:
4091 adapt::<last_h The header of the last ICAP response or
4092 meta-information from the last eCAP
4093 transaction related to the HTTP transaction.
4094 Like <h, accepts an optional header name
4097 adapt::sum_trs Summed adaptation transaction response
4098 times recorded as a comma-separated list in
4099 the order of transaction start time. Each time
4100 value is recorded as an integer number,
4101 representing response time of one or more
4102 adaptation (ICAP or eCAP) transaction in
4103 milliseconds. When a failed transaction is
4104 being retried or repeated, its time is not
4105 logged individually but added to the
4106 replacement (next) transaction. See also:
4109 adapt::all_trs All adaptation transaction response times.
4110 Same as adaptation_strs but response times of
4111 individual transactions are never added
4112 together. Instead, all transaction response
4113 times are recorded individually.
4115 You can prefix adapt::*_trs format codes with adaptation
4116 service name in curly braces to record response time(s) specific
4117 to that service. For example: %{my_service}adapt::sum_trs
4119 If SSL is enabled, the following formating codes become available:
4121 %ssl::>cert_subject The Subject field of the received client
4122 SSL certificate or a dash ('-') if Squid has
4123 received an invalid/malformed certificate or
4124 no certificate at all. Consider encoding the
4125 logged value because Subject often has spaces.
4127 %ssl::>cert_issuer The Issuer field of the received client
4128 SSL certificate or a dash ('-') if Squid has
4129 received an invalid/malformed certificate or
4130 no certificate at all. Consider encoding the
4131 logged value because Issuer often has spaces.
4133 The default formats available (which do not need re-defining) are:
4135 logformat squid %ts.%03tu %6tr %>a %Ss/%03>Hs %<st %rm %ru %[un %Sh/%<a %mt
4136 logformat common %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st %Ss:%Sh
4137 logformat combined %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st "%{Referer}>h" "%{User-Agent}>h" %Ss:%Sh
4138 logformat referrer %ts.%03tu %>a %{Referer}>h %ru
4139 logformat useragent %>a [%tl] "%{User-Agent}>h"
4141 NOTE: When the log_mime_hdrs directive is set to ON.
4142 The squid, common and combined formats have a safely encoded copy
4143 of the mime headers appended to each line within a pair of brackets.
4145 NOTE: The common and combined formats are not quite true to the Apache definition.
4146 The logs from Squid contain an extra status and hierarchy code appended.
4150 NAME: access_log cache_access_log
4152 LOC: Config.Log.accesslogs
4153 DEFAULT_IF_NONE: daemon:@DEFAULT_ACCESS_LOG@ squid
4155 Configures whether and how Squid logs HTTP and ICP transactions.
4156 If access logging is enabled, a single line is logged for every
4157 matching HTTP or ICP request. The recommended directive formats are:
4159 access_log <module>:<place> [option ...] [acl acl ...]
4160 access_log none [acl acl ...]
4162 The following directive format is accepted but may be deprecated:
4163 access_log <module>:<place> [<logformat name> [acl acl ...]]
4165 In most cases, the first ACL name must not contain the '=' character
4166 and should not be equal to an existing logformat name. You can always
4167 start with an 'all' ACL to work around those restrictions.
4169 Will log to the specified module:place using the specified format (which
4170 must be defined in a logformat directive) those entries which match
4171 ALL the acl's specified (which must be defined in acl clauses).
4172 If no acl is specified, all requests will be logged to this destination.
4174 ===== Available options for the recommended directive format =====
4176 logformat=name Names log line format (either built-in or
4177 defined by a logformat directive). Defaults
4180 buffer-size=64KB Defines approximate buffering limit for log
4181 records (see buffered_logs). Squid should not
4182 keep more than the specified size and, hence,
4183 should flush records before the buffer becomes
4184 full to avoid overflows under normal
4185 conditions (the exact flushing algorithm is
4186 module-dependent though). The on-error option
4187 controls overflow handling.
4189 on-error=die|drop Defines action on unrecoverable errors. The
4190 'drop' action ignores (i.e., does not log)
4191 affected log records. The default 'die' action
4192 kills the affected worker. The drop action
4193 support has not been tested for modules other
4196 ===== Modules Currently available =====
4198 none Do not log any requests matching these ACL.
4199 Do not specify Place or logformat name.
4201 stdio Write each log line to disk immediately at the completion of
4203 Place: the filename and path to be written.
4205 daemon Very similar to stdio. But instead of writing to disk the log
4206 line is passed to a daemon helper for asychronous handling instead.
4207 Place: varies depending on the daemon.
4209 log_file_daemon Place: the file name and path to be written.
4211 syslog To log each request via syslog facility.
4212 Place: The syslog facility and priority level for these entries.
4213 Place Format: facility.priority
4215 where facility could be any of:
4216 authpriv, daemon, local0 ... local7 or user.
4218 And priority could be any of:
4219 err, warning, notice, info, debug.
4221 udp To send each log line as text data to a UDP receiver.
4222 Place: The destination host name or IP and port.
4223 Place Format: //host:port
4225 tcp To send each log line as text data to a TCP receiver.
4226 Lines may be accumulated before sending (see buffered_logs).
4227 Place: The destination host name or IP and port.
4228 Place Format: //host:port
4231 access_log daemon:@DEFAULT_ACCESS_LOG@ squid
4237 LOC: Config.Log.icaplogs
4240 ICAP log files record ICAP transaction summaries, one line per
4243 The icap_log option format is:
4244 icap_log <filepath> [<logformat name> [acl acl ...]]
4245 icap_log none [acl acl ...]]
4247 Please see access_log option documentation for details. The two
4248 kinds of logs share the overall configuration approach and many
4251 ICAP processing of a single HTTP message or transaction may
4252 require multiple ICAP transactions. In such cases, multiple
4253 ICAP transaction log lines will correspond to a single access
4256 ICAP log uses logformat codes that make sense for an ICAP
4257 transaction. Header-related codes are applied to the HTTP header
4258 embedded in an ICAP server response, with the following caveats:
4259 For REQMOD, there is no HTTP response header unless the ICAP
4260 server performed request satisfaction. For RESPMOD, the HTTP
4261 request header is the header sent to the ICAP server. For
4262 OPTIONS, there are no HTTP headers.
4264 The following format codes are also available for ICAP logs:
4266 icap::<A ICAP server IP address. Similar to <A.
4268 icap::<service_name ICAP service name from the icap_service
4269 option in Squid configuration file.
4271 icap::ru ICAP Request-URI. Similar to ru.
4273 icap::rm ICAP request method (REQMOD, RESPMOD, or
4274 OPTIONS). Similar to existing rm.
4276 icap::>st Bytes sent to the ICAP server (TCP payload
4277 only; i.e., what Squid writes to the socket).
4279 icap::<st Bytes received from the ICAP server (TCP
4280 payload only; i.e., what Squid reads from
4283 icap::<bs Number of message body bytes received from the
4284 ICAP server. ICAP message body, if any, usually
4285 includes encapsulated HTTP message headers and
4286 possibly encapsulated HTTP message body. The
4287 HTTP body part is dechunked before its size is
4290 icap::tr Transaction response time (in
4291 milliseconds). The timer starts when
4292 the ICAP transaction is created and
4293 stops when the transaction is completed.
4296 icap::tio Transaction I/O time (in milliseconds). The
4297 timer starts when the first ICAP request
4298 byte is scheduled for sending. The timers
4299 stops when the last byte of the ICAP response
4302 icap::to Transaction outcome: ICAP_ERR* for all
4303 transaction errors, ICAP_OPT for OPTION
4304 transactions, ICAP_ECHO for 204
4305 responses, ICAP_MOD for message
4306 modification, and ICAP_SAT for request
4307 satisfaction. Similar to Ss.
4309 icap::Hs ICAP response status code. Similar to Hs.
4311 icap::>h ICAP request header(s). Similar to >h.
4313 icap::<h ICAP response header(s). Similar to <h.
4315 The default ICAP log format, which can be used without an explicit
4316 definition, is called icap_squid:
4318 logformat icap_squid %ts.%03tu %6icap::tr %>a %icap::to/%03icap::Hs %icap::<size %icap::rm %icap::ru% %un -/%icap::<A -
4320 See also: logformat, log_icap, and %adapt::<last_h
4323 NAME: logfile_daemon
4325 DEFAULT: @DEFAULT_LOGFILED@
4326 LOC: Log::TheConfig.logfile_daemon
4328 Specify the path to the logfile-writing daemon. This daemon is
4329 used to write the access and store logs, if configured.
4331 Squid sends a number of commands to the log daemon:
4332 L<data>\n - logfile data
4337 r<n>\n - set rotate count to <n>
4338 b<n>\n - 1 = buffer output, 0 = don't buffer output
4340 No responses is expected.
4343 NAME: stats_collection
4345 LOC: Config.accessList.stats_collection
4347 DEFAULT_DOC: Allow logging for all transactions.
4348 COMMENT: allow|deny acl acl...
4350 This options allows you to control which requests gets accounted
4351 in performance counters.
4353 This clause only supports fast acl types.
4354 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4357 NAME: cache_store_log
4360 LOC: Config.Log.store
4362 Logs the activities of the storage manager. Shows which
4363 objects are ejected from the cache, and which objects are
4364 saved and for how long.
4365 There are not really utilities to analyze this data, so you can safely
4366 disable it (the default).
4368 Store log uses modular logging outputs. See access_log for the list
4369 of modules supported.
4372 cache_store_log stdio:@DEFAULT_STORE_LOG@
4373 cache_store_log daemon:@DEFAULT_STORE_LOG@
4376 NAME: cache_swap_state cache_swap_log
4378 LOC: Config.Log.swap
4380 DEFAULT_DOC: Store the journal inside its cache_dir
4382 Location for the cache "swap.state" file. This index file holds
4383 the metadata of objects saved on disk. It is used to rebuild
4384 the cache during startup. Normally this file resides in each
4385 'cache_dir' directory, but you may specify an alternate
4386 pathname here. Note you must give a full filename, not just
4387 a directory. Since this is the index for the whole object
4388 list you CANNOT periodically rotate it!
4390 If %s can be used in the file name it will be replaced with a
4391 a representation of the cache_dir name where each / is replaced
4392 with '.'. This is needed to allow adding/removing cache_dir
4393 lines when cache_swap_log is being used.
4395 If have more than one 'cache_dir', and %s is not used in the name
4396 these swap logs will have names such as:
4402 The numbered extension (which is added automatically)
4403 corresponds to the order of the 'cache_dir' lines in this
4404 configuration file. If you change the order of the 'cache_dir'
4405 lines in this file, these index files will NOT correspond to
4406 the correct 'cache_dir' entry (unless you manually rename
4407 them). We recommend you do NOT use this option. It is
4408 better to keep these index files in each 'cache_dir' directory.
4411 NAME: logfile_rotate
4414 LOC: Config.Log.rotateNumber
4416 Specifies the number of logfile rotations to make when you
4417 type 'squid -k rotate'. The default is 10, which will rotate
4418 with extensions 0 through 9. Setting logfile_rotate to 0 will
4419 disable the file name rotation, but the logfiles are still closed
4420 and re-opened. This will enable you to rename the logfiles
4421 yourself just before sending the rotate signal.
4423 Note, the 'squid -k rotate' command normally sends a USR1
4424 signal to the running squid process. In certain situations
4425 (e.g. on Linux with Async I/O), USR1 is used for other
4426 purposes, so -k rotate uses another signal. It is best to get
4427 in the habit of using 'squid -k rotate' instead of 'kill -USR1
4430 Note, from Squid-3.1 this option is only a default for cache.log,
4431 that log can be rotated separately by using debug_options.
4436 DEFAULT: @DEFAULT_MIME_TABLE@
4437 LOC: Config.mimeTablePathname
4439 Path to Squid's icon configuration file.
4441 You shouldn't need to change this, but the default file contains
4442 examples and formatting information if you do.
4448 LOC: Config.onoff.log_mime_hdrs
4451 The Cache can record both the request and the response MIME
4452 headers for each HTTP transaction. The headers are encoded
4453 safely and will appear as two bracketed fields at the end of
4454 the access log (for either the native or httpd-emulated log
4455 formats). To enable this logging set log_mime_hdrs to 'on'.
4460 DEFAULT: @DEFAULT_PID_FILE@
4461 LOC: Config.pidFilename
4463 A filename to write the process-id to. To disable, enter "none".
4466 NAME: client_netmask
4468 LOC: Config.Addrs.client_netmask
4470 DEFAULT_DOC: Log full client IP address
4472 A netmask for client addresses in logfiles and cachemgr output.
4473 Change this to protect the privacy of your cache clients.
4474 A netmask of 255.255.255.0 will log all IP's in that range with
4475 the last digit set to '0'.
4478 NAME: strip_query_terms
4480 LOC: Config.onoff.strip_query_terms
4483 By default, Squid strips query terms from requested URLs before
4484 logging. This protects your user's privacy and reduces log size.
4486 When investigating HIT/MISS or other caching behaviour you
4487 will need to disable this to see the full URL used by Squid.
4494 LOC: Config.onoff.buffered_logs
4496 Whether to write/send access_log records ASAP or accumulate them and
4497 then write/send them in larger chunks. Buffering may improve
4498 performance because it decreases the number of I/Os. However,
4499 buffering increases the delay before log records become available to
4500 the final recipient (e.g., a disk file or logging daemon) and,
4501 hence, increases the risk of log records loss.
4503 Note that even when buffered_logs are off, Squid may have to buffer
4504 records if it cannot write/send them immediately due to pending I/Os
4505 (e.g., the I/O writing the previous log record) or connectivity loss.
4507 Currently honored by 'daemon' and 'tcp' access_log modules only.
4510 NAME: netdb_filename
4512 DEFAULT: stdio:@DEFAULT_NETDB_FILE@
4513 LOC: Config.netdbFilename
4516 Where Squid stores it's netdb journal.
4517 When enabled this journal preserves netdb state between restarts.
4519 To disable, enter "none".
4523 OPTIONS FOR TROUBLESHOOTING
4524 -----------------------------------------------------------------------------
4529 DEFAULT_IF_NONE: @DEFAULT_CACHE_LOG@
4530 LOC: Debug::cache_log
4532 Squid administrative logging file.
4534 This is where general information about Squid behavior goes. You can
4535 increase the amount of data logged to this file and how often it is
4536 rotated with "debug_options"
4542 DEFAULT_DOC: Log all critical and important messages.
4543 LOC: Debug::debugOptions
4545 Logging options are set as section,level where each source file
4546 is assigned a unique section. Lower levels result in less
4547 output, Full debugging (level 9) can result in a very large
4548 log file, so be careful.
4550 The magic word "ALL" sets debugging levels for all sections.
4551 The default is to run with "ALL,1" to record important warnings.
4553 The rotate=N option can be used to keep more or less of these logs
4554 than would otherwise be kept by logfile_rotate.
4555 For most uses a single log should be enough to monitor current
4556 events affecting Squid.
4561 LOC: Config.coredump_dir
4562 DEFAULT_IF_NONE: none
4563 DEFAULT_DOC: Use the directory from where Squid was started.
4565 By default Squid leaves core files in the directory from where
4566 it was started. If you set 'coredump_dir' to a directory
4567 that exists, Squid will chdir() to that directory at startup
4568 and coredump files will be left there.
4572 # Leave coredumps in the first cache dir
4573 coredump_dir @DEFAULT_SWAP_DIR@
4579 OPTIONS FOR FTP GATEWAYING
4580 -----------------------------------------------------------------------------
4586 LOC: Config.Ftp.anon_user
4588 If you want the anonymous login password to be more informative
4589 (and enable the use of picky FTP servers), set this to something
4590 reasonable for your domain, like wwwuser@somewhere.net
4592 The reason why this is domainless by default is the
4593 request can be made on the behalf of a user in any domain,
4594 depending on how the cache is used.
4595 Some FTP server also validate the email address is valid
4596 (for example perl.com).
4602 LOC: Config.Ftp.passive
4604 If your firewall does not allow Squid to use passive
4605 connections, turn off this option.
4607 Use of ftp_epsv_all option requires this to be ON.
4613 LOC: Config.Ftp.epsv_all
4615 FTP Protocol extensions permit the use of a special "EPSV ALL" command.
4617 NATs may be able to put the connection on a "fast path" through the
4618 translator, as the EPRT command will never be used and therefore,
4619 translation of the data portion of the segments will never be needed.
4621 When a client only expects to do two-way FTP transfers this may be
4623 If squid finds that it must do a three-way FTP transfer after issuing
4624 an EPSV ALL command, the FTP session will fail.
4626 If you have any doubts about this option do not use it.
4627 Squid will nicely attempt all other connection methods.
4629 Requires ftp_passive to be ON (default) for any effect.
4635 LOC: Config.accessList.ftp_epsv
4637 FTP Protocol extensions permit the use of a special "EPSV" command.
4639 NATs may be able to put the connection on a "fast path" through the
4640 translator using EPSV, as the EPRT command will never be used
4641 and therefore, translation of the data portion of the segments
4642 will never be needed.
4644 EPSV is often required to interoperate with FTP servers on IPv6
4645 networks. On the other hand, it may break some IPv4 servers.
4647 By default, EPSV may try EPSV with any FTP server. To fine tune
4648 that decision, you may restrict EPSV to certain clients or servers
4651 ftp_epsv allow|deny al1 acl2 ...
4653 WARNING: Disabling EPSV may cause problems with external NAT and IPv6.
4655 Only fast ACLs are supported.
4656 Requires ftp_passive to be ON (default) for any effect.
4662 LOC: Config.Ftp.eprt
4664 FTP Protocol extensions permit the use of a special "EPRT" command.
4666 This extension provides a protocol neutral alternative to the
4667 IPv4-only PORT command. When supported it enables active FTP data
4668 channels over IPv6 and efficient NAT handling.
4670 Turning this OFF will prevent EPRT being attempted and will skip
4671 straight to using PORT for IPv4 servers.
4673 Some devices are known to not handle this extension correctly and
4674 may result in crashes. Devices which suport EPRT enough to fail
4675 cleanly will result in Squid attempting PORT anyway. This directive
4676 should only be disabled when EPRT results in device failures.
4678 WARNING: Doing so will convert Squid back to the old behavior with all
4679 the related problems with external NAT devices/layers and IPv4-only FTP.
4682 NAME: ftp_sanitycheck
4685 LOC: Config.Ftp.sanitycheck
4687 For security and data integrity reasons Squid by default performs
4688 sanity checks of the addresses of FTP data connections ensure the
4689 data connection is to the requested server. If you need to allow
4690 FTP connections to servers using another IP address for the data
4691 connection turn this off.
4694 NAME: ftp_telnet_protocol
4697 LOC: Config.Ftp.telnet
4699 The FTP protocol is officially defined to use the telnet protocol
4700 as transport channel for the control connection. However, many
4701 implementations are broken and does not respect this aspect of
4704 If you have trouble accessing files with ASCII code 255 in the
4705 path or similar problems involving this ASCII code you can
4706 try setting this directive to off. If that helps, report to the
4707 operator of the FTP server in question that their FTP server
4708 is broken and does not follow the FTP standard.
4712 OPTIONS FOR EXTERNAL SUPPORT PROGRAMS
4713 -----------------------------------------------------------------------------
4718 DEFAULT: @DEFAULT_DISKD@
4719 LOC: Config.Program.diskd
4721 Specify the location of the diskd executable.
4722 Note this is only useful if you have compiled in
4723 diskd as one of the store io modules.
4726 NAME: unlinkd_program
4729 DEFAULT: @DEFAULT_UNLINKD@
4730 LOC: Config.Program.unlinkd
4732 Specify the location of the executable for file deletion process.
4735 NAME: pinger_program
4737 DEFAULT: @DEFAULT_PINGER@
4738 LOC: Config.pinger.program
4741 Specify the location of the executable for the pinger process.
4747 LOC: Config.pinger.enable
4750 Control whether the pinger is active at run-time.
4751 Enables turning ICMP pinger on and off with a simple
4752 squid -k reconfigure.
4757 OPTIONS FOR URL REWRITING
4758 -----------------------------------------------------------------------------
4761 NAME: url_rewrite_program redirect_program
4763 LOC: Config.Program.redirect
4766 Specify the location of the executable URL rewriter to use.
4767 Since they can perform almost any function there isn't one included.
4769 For each requested URL, the rewriter will receive on line with the format
4771 [channel-ID <SP>] URL [<SP> extras]<NL>
4773 See url_rewrite_extras on how to send "extras" with optional values to
4775 After processing the request the helper must reply using the following format:
4777 [channel-ID <SP>] result [<SP> kv-pairs]
4779 The result code can be:
4781 OK status=30N url="..."
4782 Redirect the URL to the one supplied in 'url='.
4783 'status=' is optional and contains the status code to send
4784 the client in Squids HTTP response. It must be one of the
4785 HTTP redirect status codes: 301, 302, 303, 307, 308.
4786 When no status is given Squid will use 302.
4788 OK rewrite-url="..."
4789 Rewrite the URL to the one supplied in 'rewrite-url='.
4790 The new URL is fetched directly by Squid and returned to
4791 the client as the response to its request.
4794 When neither of url= and rewrite-url= are sent Squid does
4798 Do not change the URL.
4801 An internal error occurred in the helper, preventing
4802 a result being identified. The 'message=' key name is
4803 reserved for delivering a log message.
4806 In addition to the above kv-pairs Squid also understands the following
4807 optional kv-pairs received from URL rewriters:
4809 Associates a TAG with the client TCP connection.
4810 The TAG is treated as a regular annotation but persists across
4811 future requests on the client connection rather than just the
4812 current request. A helper may update the TAG during subsequent
4813 requests be returning a new kv-pair.
4815 When using the concurrency= option the protocol is changed by
4816 introducing a query channel tag in front of the request/response.
4817 The query channel tag is a number between 0 and concurrency-1.
4818 This value must be echoed back unchanged to Squid as the first part
4819 of the response relating to its request.
4821 WARNING: URL re-writing ability should be avoided whenever possible.
4822 Use the URL redirect form of response instead.
4824 Re-write creates a difference in the state held by the client
4825 and server. Possibly causing confusion when the server response
4826 contains snippets of its view state. Embeded URLs, response
4827 and content Location headers, etc. are not re-written by this
4830 By default, a URL rewriter is not used.
4833 NAME: url_rewrite_children redirect_children
4834 TYPE: HelperChildConfig
4835 DEFAULT: 20 startup=0 idle=1 concurrency=0
4836 LOC: Config.redirectChildren
4838 The maximum number of redirector processes to spawn. If you limit
4839 it too few Squid will have to wait for them to process a backlog of
4840 URLs, slowing it down. If you allow too many they will use RAM
4841 and other system resources noticably.
4843 The startup= and idle= options allow some measure of skew in your
4848 Sets a minimum of how many processes are to be spawned when Squid
4849 starts or reconfigures. When set to zero the first request will
4850 cause spawning of the first child process to handle it.
4852 Starting too few will cause an initial slowdown in traffic as Squid
4853 attempts to simultaneously spawn enough processes to cope.
4857 Sets a minimum of how many processes Squid is to try and keep available
4858 at all times. When traffic begins to rise above what the existing
4859 processes can handle this many more will be spawned up to the maximum
4860 configured. A minimum setting of 1 is required.
4864 The number of requests each redirector helper can handle in
4865 parallel. Defaults to 0 which indicates the redirector
4866 is a old-style single threaded redirector.
4868 When this directive is set to a value >= 1 then the protocol
4869 used to communicate with the helper is modified to include
4870 an ID in front of the request/response. The ID from the request
4871 must be echoed back with the response to that request.
4874 NAME: url_rewrite_host_header redirect_rewrites_host_header
4877 LOC: Config.onoff.redir_rewrites_host
4879 To preserve same-origin security policies in browsers and
4880 prevent Host: header forgery by redirectors Squid rewrites
4881 any Host: header in redirected requests.
4883 If you are running an accelerator this may not be a wanted
4884 effect of a redirector. This directive enables you disable
4885 Host: alteration in reverse-proxy traffic.
4887 WARNING: Entries are cached on the result of the URL rewriting
4888 process, so be careful if you have domain-virtual hosts.
4890 WARNING: Squid and other software verifies the URL and Host
4891 are matching, so be careful not to relay through other proxies
4892 or inspecting firewalls with this disabled.
4895 NAME: url_rewrite_access redirector_access
4898 DEFAULT_DOC: Allow, unless rules exist in squid.conf.
4899 LOC: Config.accessList.redirector
4901 If defined, this access list specifies which requests are
4902 sent to the redirector processes.
4904 This clause supports both fast and slow acl types.
4905 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4908 NAME: url_rewrite_bypass redirector_bypass
4910 LOC: Config.onoff.redirector_bypass
4913 When this is 'on', a request will not go through the
4914 redirector if all the helpers are busy. If this is 'off'
4915 and the redirector queue grows too large, Squid will exit
4916 with a FATAL error and ask you to increase the number of
4917 redirectors. You should only enable this if the redirectors
4918 are not critical to your caching system. If you use
4919 redirectors for access control, and you enable this option,
4920 users may have access to pages they should not
4921 be allowed to request.
4924 NAME: url_rewrite_extras
4925 TYPE: TokenOrQuotedString
4926 LOC: Config.redirector_extras
4927 DEFAULT: "%>a/%>A %un %>rm myip=%la myport=%lp"
4929 Specifies a string to be append to request line format for the
4930 rewriter helper. "Quoted" format values may contain spaces and
4931 logformat %macros. In theory, any logformat %macro can be used.
4932 In practice, a %macro expands as a dash (-) if the helper request is
4933 sent before the required macro information is available to Squid.
4937 OPTIONS FOR STORE ID
4938 -----------------------------------------------------------------------------
4941 NAME: store_id_program storeurl_rewrite_program
4943 LOC: Config.Program.store_id
4946 Specify the location of the executable StoreID helper to use.
4947 Since they can perform almost any function there isn't one included.
4949 For each requested URL, the helper will receive one line with the format
4951 [channel-ID <SP>] URL [<SP> extras]<NL>
4954 After processing the request the helper must reply using the following format:
4956 [channel-ID <SP>] result [<SP> kv-pairs]
4958 The result code can be:
4961 Use the StoreID supplied in 'store-id='.
4964 The default is to use HTTP request URL as the store ID.
4967 An internal error occured in the helper, preventing
4968 a result being identified.
4970 In addition to the above kv-pairs Squid also understands the following
4971 optional kv-pairs received from URL rewriters:
4973 Associates a TAG with the client TCP connection.
4974 Please see url_rewrite_program related documentation for this
4977 Helper programs should be prepared to receive and possibly ignore
4978 additional whitespace-separated tokens on each input line.
4980 When using the concurrency= option the protocol is changed by
4981 introducing a query channel tag in front of the request/response.
4982 The query channel tag is a number between 0 and concurrency-1.
4983 This value must be echoed back unchanged to Squid as the first part
4984 of the response relating to its request.
4986 NOTE: when using StoreID refresh_pattern will apply to the StoreID
4987 returned from the helper and not the URL.
4989 WARNING: Wrong StoreID value returned by a careless helper may result
4990 in the wrong cached response returned to the user.
4992 By default, a StoreID helper is not used.
4995 NAME: store_id_extras
4996 TYPE: TokenOrQuotedString
4997 LOC: Config.storeId_extras
4998 DEFAULT: "%>a/%>A %un %>rm myip=%la myport=%lp"
5000 Specifies a string to be append to request line format for the
5001 StoreId helper. "Quoted" format values may contain spaces and
5002 logformat %macros. In theory, any logformat %macro can be used.
5003 In practice, a %macro expands as a dash (-) if the helper request is
5004 sent before the required macro information is available to Squid.
5007 NAME: store_id_children storeurl_rewrite_children
5008 TYPE: HelperChildConfig
5009 DEFAULT: 20 startup=0 idle=1 concurrency=0
5010 LOC: Config.storeIdChildren
5012 The maximum number of StoreID helper processes to spawn. If you limit
5013 it too few Squid will have to wait for them to process a backlog of
5014 requests, slowing it down. If you allow too many they will use RAM
5015 and other system resources noticably.
5017 The startup= and idle= options allow some measure of skew in your
5022 Sets a minimum of how many processes are to be spawned when Squid
5023 starts or reconfigures. When set to zero the first request will
5024 cause spawning of the first child process to handle it.
5026 Starting too few will cause an initial slowdown in traffic as Squid
5027 attempts to simultaneously spawn enough processes to cope.
5031 Sets a minimum of how many processes Squid is to try and keep available
5032 at all times. When traffic begins to rise above what the existing
5033 processes can handle this many more will be spawned up to the maximum
5034 configured. A minimum setting of 1 is required.
5038 The number of requests each storeID helper can handle in
5039 parallel. Defaults to 0 which indicates the helper
5040 is a old-style single threaded program.
5042 When this directive is set to a value >= 1 then the protocol
5043 used to communicate with the helper is modified to include
5044 an ID in front of the request/response. The ID from the request
5045 must be echoed back with the response to that request.
5048 NAME: store_id_access storeurl_rewrite_access
5051 DEFAULT_DOC: Allow, unless rules exist in squid.conf.
5052 LOC: Config.accessList.store_id
5054 If defined, this access list specifies which requests are
5055 sent to the StoreID processes. By default all requests
5058 This clause supports both fast and slow acl types.
5059 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5062 NAME: store_id_bypass storeurl_rewrite_bypass
5064 LOC: Config.onoff.store_id_bypass
5067 When this is 'on', a request will not go through the
5068 helper if all helpers are busy. If this is 'off'
5069 and the helper queue grows too large, Squid will exit
5070 with a FATAL error and ask you to increase the number of
5071 helpers. You should only enable this if the helperss
5072 are not critical to your caching system. If you use
5073 helpers for critical caching components, and you enable this
5074 option, users may not get objects from cache.
5078 OPTIONS FOR TUNING THE CACHE
5079 -----------------------------------------------------------------------------
5082 NAME: cache no_cache
5085 DEFAULT_DOC: By default, this directive is unused and has no effect.
5086 LOC: Config.accessList.noCache
5088 Requests denied by this directive will not be served from the cache
5089 and their responses will not be stored in the cache. This directive
5090 has no effect on other transactions and on already cached responses.
5092 This clause supports both fast and slow acl types.
5093 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5095 This and the two other similar caching directives listed below are
5096 checked at different transaction processing stages, have different
5097 access to response information, affect different cache operations,
5098 and differ in slow ACLs support:
5100 * cache: Checked before Squid makes a hit/miss determination.
5101 No access to reply information!
5102 Denies both serving a hit and storing a miss.
5103 Supports both fast and slow ACLs.
5104 * send_hit: Checked after a hit was detected.
5105 Has access to reply (hit) information.
5106 Denies serving a hit only.
5107 Supports fast ACLs only.
5108 * store_miss: Checked before storing a cachable miss.
5109 Has access to reply (miss) information.
5110 Denies storing a miss only.
5111 Supports fast ACLs only.
5113 If you are not sure which of the three directives to use, apply the
5114 following decision logic:
5116 * If your ACL(s) are of slow type _and_ need response info, redesign.
5117 Squid does not support that particular combination at this time.
5119 * If your directive ACL(s) are of slow type, use "cache"; and/or
5120 * if your directive ACL(s) need no response info, use "cache".
5122 * If you do not want the response cached, use store_miss; and/or
5123 * if you do not want a hit on a cached response, use send_hit.
5129 DEFAULT_DOC: By default, this directive is unused and has no effect.
5130 LOC: Config.accessList.sendHit
5132 Responses denied by this directive will not be served from the cache
5133 (but may still be cached, see store_miss). This directive has no
5134 effect on the responses it allows and on the cached objects.
5136 Please see the "cache" directive for a summary of differences among
5137 store_miss, send_hit, and cache directives.
5139 Unlike the "cache" directive, send_hit only supports fast acl
5140 types. See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5144 # apply custom Store ID mapping to some URLs
5145 acl MapMe dstdomain .c.example.com
5146 store_id_program ...
5147 store_id_access allow MapMe
5149 # but prevent caching of special responses
5150 # such as 302 redirects that cause StoreID loops
5151 acl Ordinary http_status 200-299
5152 store_miss deny MapMe !Ordinary
5154 # and do not serve any previously stored special responses
5155 # from the cache (in case they were already cached before
5156 # the above store_miss rule was in effect).
5157 send_hit deny MapMe !Ordinary
5163 DEFAULT_DOC: By default, this directive is unused and has no effect.
5164 LOC: Config.accessList.storeMiss
5166 Responses denied by this directive will not be cached (but may still
5167 be served from the cache, see send_hit). This directive has no
5168 effect on the responses it allows and on the already cached responses.
5170 Please see the "cache" directive for a summary of differences among
5171 store_miss, send_hit, and cache directives. See the
5172 send_hit directive for a usage example.
5174 Unlike the "cache" directive, store_miss only supports fast acl
5175 types. See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5181 LOC: Config.maxStale
5184 This option puts an upper limit on how stale content Squid
5185 will serve from the cache if cache validation fails.
5186 Can be overriden by the refresh_pattern max-stale option.
5189 NAME: refresh_pattern
5190 TYPE: refreshpattern
5194 usage: refresh_pattern [-i] regex min percent max [options]
5196 By default, regular expressions are CASE-SENSITIVE. To make
5197 them case-insensitive, use the -i option.
5199 'Min' is the time (in minutes) an object without an explicit
5200 expiry time should be considered fresh. The recommended
5201 value is 0, any higher values may cause dynamic applications
5202 to be erroneously cached unless the application designer
5203 has taken the appropriate actions.
5205 'Percent' is a percentage of the objects age (time since last
5206 modification age) an object without explicit expiry time
5207 will be considered fresh.
5209 'Max' is an upper limit on how long objects without an explicit
5210 expiry time will be considered fresh.
5212 options: override-expire
5217 ignore-must-revalidate
5224 override-expire enforces min age even if the server
5225 sent an explicit expiry time (e.g., with the
5226 Expires: header or Cache-Control: max-age). Doing this
5227 VIOLATES the HTTP standard. Enabling this feature
5228 could make you liable for problems which it causes.
5230 Note: override-expire does not enforce staleness - it only extends
5231 freshness / min. If the server returns a Expires time which
5232 is longer than your max time, Squid will still consider
5233 the object fresh for that period of time.
5235 override-lastmod enforces min age even on objects
5236 that were modified recently.
5238 reload-into-ims changes a client no-cache or ``reload''
5239 request for a cached entry into a conditional request using
5240 If-Modified-Since and/or If-None-Match headers, provided the
5241 cached entry has a Last-Modified and/or a strong ETag header.
5242 Doing this VIOLATES the HTTP standard. Enabling this feature
5243 could make you liable for problems which it causes.
5245 ignore-reload ignores a client no-cache or ``reload''
5246 header. Doing this VIOLATES the HTTP standard. Enabling
5247 this feature could make you liable for problems which
5250 ignore-no-store ignores any ``Cache-control: no-store''
5251 headers received from a server. Doing this VIOLATES
5252 the HTTP standard. Enabling this feature could make you
5253 liable for problems which it causes.
5255 ignore-must-revalidate ignores any ``Cache-Control: must-revalidate``
5256 headers received from a server. Doing this VIOLATES
5257 the HTTP standard. Enabling this feature could make you
5258 liable for problems which it causes.
5260 ignore-private ignores any ``Cache-control: private''
5261 headers received from a server. Doing this VIOLATES
5262 the HTTP standard. Enabling this feature could make you
5263 liable for problems which it causes.
5265 ignore-auth caches responses to requests with authorization,
5266 as if the originserver had sent ``Cache-control: public''
5267 in the response header. Doing this VIOLATES the HTTP standard.
5268 Enabling this feature could make you liable for problems which
5271 refresh-ims causes squid to contact the origin server
5272 when a client issues an If-Modified-Since request. This
5273 ensures that the client will receive an updated version
5274 if one is available.
5276 store-stale stores responses even if they don't have explicit
5277 freshness or a validator (i.e., Last-Modified or an ETag)
5278 present, or if they're already stale. By default, Squid will
5279 not cache such responses because they usually can't be
5280 reused. Note that such responses will be stale by default.
5282 max-stale=NN provide a maximum staleness factor. Squid won't
5283 serve objects more stale than this even if it failed to
5284 validate the object. Default: use the max_stale global limit.
5286 Basically a cached object is:
5288 FRESH if expires < now, else STALE
5290 FRESH if lm-factor < percent, else STALE
5294 The refresh_pattern lines are checked in the order listed here.
5295 The first entry which matches is used. If none of the entries
5296 match the default will be used.
5298 Note, you must uncomment all the default lines if you want
5299 to change one. The default setting is only active if none is
5305 # Add any of your own refresh_pattern entries above these.
5307 refresh_pattern ^ftp: 1440 20% 10080
5308 refresh_pattern ^gopher: 1440 0% 1440
5309 refresh_pattern -i (/cgi-bin/|\?) 0 0% 0
5310 refresh_pattern . 0 20% 4320
5314 NAME: quick_abort_min
5318 LOC: Config.quickAbort.min
5321 NAME: quick_abort_max
5325 LOC: Config.quickAbort.max
5328 NAME: quick_abort_pct
5332 LOC: Config.quickAbort.pct
5334 The cache by default continues downloading aborted requests
5335 which are almost completed (less than 16 KB remaining). This
5336 may be undesirable on slow (e.g. SLIP) links and/or very busy
5337 caches. Impatient users may tie up file descriptors and
5338 bandwidth by repeatedly requesting and immediately aborting
5341 When the user aborts a request, Squid will check the
5342 quick_abort values to the amount of data transferred until
5345 If the transfer has less than 'quick_abort_min' KB remaining,
5346 it will finish the retrieval.
5348 If the transfer has more than 'quick_abort_max' KB remaining,
5349 it will abort the retrieval.
5351 If more than 'quick_abort_pct' of the transfer has completed,
5352 it will finish the retrieval.
5354 If you do not want any retrieval to continue after the client
5355 has aborted, set both 'quick_abort_min' and 'quick_abort_max'
5358 If you want retrievals to always continue if they are being
5359 cached set 'quick_abort_min' to '-1 KB'.
5362 NAME: read_ahead_gap
5363 COMMENT: buffer-size
5365 LOC: Config.readAheadGap
5368 The amount of data the cache will buffer ahead of what has been
5369 sent to the client when retrieving an object from another server.
5373 IFDEF: USE_HTTP_VIOLATIONS
5376 LOC: Config.negativeTtl
5379 Set the Default Time-to-Live (TTL) for failed requests.
5380 Certain types of failures (such as "connection refused" and
5381 "404 Not Found") are able to be negatively-cached for a short time.
5382 Modern web servers should provide Expires: header, however if they
5383 do not this can provide a minimum TTL.
5384 The default is not to cache errors with unknown expiry details.
5386 Note that this is different from negative caching of DNS lookups.
5388 WARNING: Doing this VIOLATES the HTTP standard. Enabling
5389 this feature could make you liable for problems which it
5393 NAME: positive_dns_ttl
5396 LOC: Config.positiveDnsTtl
5399 Upper limit on how long Squid will cache positive DNS responses.
5400 Default is 6 hours (360 minutes). This directive must be set
5401 larger than negative_dns_ttl.
5404 NAME: negative_dns_ttl
5407 LOC: Config.negativeDnsTtl
5410 Time-to-Live (TTL) for negative caching of failed DNS lookups.
5411 This also sets the lower cache limit on positive lookups.
5412 Minimum value is 1 second, and it is not recommendable to go
5413 much below 10 seconds.
5416 NAME: range_offset_limit
5417 COMMENT: size [acl acl...]
5419 LOC: Config.rangeOffsetLimit
5422 usage: (size) [units] [[!]aclname]
5424 Sets an upper limit on how far (number of bytes) into the file
5425 a Range request may be to cause Squid to prefetch the whole file.
5426 If beyond this limit, Squid forwards the Range request as it is and
5427 the result is NOT cached.
5429 This is to stop a far ahead range request (lets say start at 17MB)
5430 from making Squid fetch the whole object up to that point before
5431 sending anything to the client.
5433 Multiple range_offset_limit lines may be specified, and they will
5434 be searched from top to bottom on each request until a match is found.
5435 The first match found will be used. If no line matches a request, the
5436 default limit of 0 bytes will be used.
5438 'size' is the limit specified as a number of units.
5440 'units' specifies whether to use bytes, KB, MB, etc.
5441 If no units are specified bytes are assumed.
5443 A size of 0 causes Squid to never fetch more than the
5444 client requested. (default)
5446 A size of 'none' causes Squid to always fetch the object from the
5447 beginning so it may cache the result. (2.0 style)
5449 'aclname' is the name of a defined ACL.
5451 NP: Using 'none' as the byte value here will override any quick_abort settings
5452 that may otherwise apply to the range request. The range request will
5453 be fully fetched from start to finish regardless of the client
5454 actions. This affects bandwidth usage.
5457 NAME: minimum_expiry_time
5460 LOC: Config.minimum_expiry_time
5463 The minimum caching time according to (Expires - Date)
5464 headers Squid honors if the object can't be revalidated.
5465 The default is 60 seconds.
5467 In reverse proxy environments it might be desirable to honor
5468 shorter object lifetimes. It is most likely better to make
5469 your server return a meaningful Last-Modified header however.
5471 In ESI environments where page fragments often have short
5472 lifetimes, this will often be best set to 0.
5475 NAME: store_avg_object_size
5479 LOC: Config.Store.avgObjectSize
5481 Average object size, used to estimate number of objects your
5482 cache can hold. The default is 13 KB.
5484 This is used to pre-seed the cache index memory allocation to
5485 reduce expensive reallocate operations while handling clients
5486 traffic. Too-large values may result in memory allocation during
5487 peak traffic, too-small values will result in wasted memory.
5489 Check the cache manager 'info' report metrics for the real
5490 object sizes seen by your Squid before tuning this.
5493 NAME: store_objects_per_bucket
5496 LOC: Config.Store.objectsPerBucket
5498 Target number of objects per bucket in the store hash table.
5499 Lowering this value increases the total number of buckets and
5500 also the storage maintenance rate. The default is 20.
5505 -----------------------------------------------------------------------------
5508 NAME: request_header_max_size
5512 LOC: Config.maxRequestHeaderSize
5514 This specifies the maximum size for HTTP headers in a request.
5515 Request headers are usually relatively small (about 512 bytes).
5516 Placing a limit on the request header size will catch certain
5517 bugs (for example with persistent connections) and possibly
5518 buffer-overflow or denial-of-service attacks.
5521 NAME: reply_header_max_size
5525 LOC: Config.maxReplyHeaderSize
5527 This specifies the maximum size for HTTP headers in a reply.
5528 Reply headers are usually relatively small (about 512 bytes).
5529 Placing a limit on the reply header size will catch certain
5530 bugs (for example with persistent connections) and possibly
5531 buffer-overflow or denial-of-service attacks.
5534 NAME: request_body_max_size
5538 DEFAULT_DOC: No limit.
5539 LOC: Config.maxRequestBodySize
5541 This specifies the maximum size for an HTTP request body.
5542 In other words, the maximum size of a PUT/POST request.
5543 A user who attempts to send a request with a body larger
5544 than this limit receives an "Invalid Request" error message.
5545 If you set this parameter to a zero (the default), there will
5546 be no limit imposed.
5548 See also client_request_buffer_max_size for an alternative
5549 limitation on client uploads which can be configured.
5552 NAME: client_request_buffer_max_size
5556 LOC: Config.maxRequestBufferSize
5558 This specifies the maximum buffer size of a client request.
5559 It prevents squid eating too much memory when somebody uploads
5563 NAME: chunked_request_body_max_size
5567 LOC: Config.maxChunkedRequestBodySize
5569 A broken or confused HTTP/1.1 client may send a chunked HTTP
5570 request to Squid. Squid does not have full support for that
5571 feature yet. To cope with such requests, Squid buffers the
5572 entire request and then dechunks request body to create a
5573 plain HTTP/1.0 request with a known content length. The plain
5574 request is then used by the rest of Squid code as usual.
5576 The option value specifies the maximum size of the buffer used
5577 to hold the request before the conversion. If the chunked
5578 request size exceeds the specified limit, the conversion
5579 fails, and the client receives an "unsupported request" error,
5580 as if dechunking was disabled.
5582 Dechunking is enabled by default. To disable conversion of
5583 chunked requests, set the maximum to zero.
5585 Request dechunking feature and this option in particular are a
5586 temporary hack. When chunking requests and responses are fully
5587 supported, there will be no need to buffer a chunked request.
5591 IFDEF: USE_HTTP_VIOLATIONS
5594 DEFAULT_DOC: Obey RFC 2616.
5595 LOC: Config.accessList.brokenPosts
5597 A list of ACL elements which, if matched, causes Squid to send
5598 an extra CRLF pair after the body of a PUT/POST request.
5600 Some HTTP servers has broken implementations of PUT/POST,
5601 and rely on an extra CRLF pair sent by some WWW clients.
5603 Quote from RFC2616 section 4.1 on this matter:
5605 Note: certain buggy HTTP/1.0 client implementations generate an
5606 extra CRLF's after a POST request. To restate what is explicitly
5607 forbidden by the BNF, an HTTP/1.1 client must not preface or follow
5608 a request with an extra CRLF.
5610 This clause only supports fast acl types.
5611 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5614 acl buggy_server url_regex ^http://....
5615 broken_posts allow buggy_server
5618 NAME: adaptation_uses_indirect_client icap_uses_indirect_client
5621 IFDEF: FOLLOW_X_FORWARDED_FOR&&USE_ADAPTATION
5623 LOC: Adaptation::Config::use_indirect_client
5625 Controls whether the indirect client IP address (instead of the direct
5626 client IP address) is passed to adaptation services.
5628 See also: follow_x_forwarded_for adaptation_send_client_ip
5632 IFDEF: USE_HTTP_VIOLATIONS
5636 LOC: Config.onoff.via
5638 If set (default), Squid will include a Via header in requests and
5639 replies as required by RFC2616.
5645 LOC: Config.onoff.ie_refresh
5648 Microsoft Internet Explorer up until version 5.5 Service
5649 Pack 1 has an issue with transparent proxies, wherein it
5650 is impossible to force a refresh. Turning this on provides
5651 a partial fix to the problem, by causing all IMS-REFRESH
5652 requests from older IE versions to check the origin server
5653 for fresh content. This reduces hit ratio by some amount
5654 (~10% in my experience), but allows users to actually get
5655 fresh content when they want it. Note because Squid
5656 cannot tell if the user is using 5.5 or 5.5SP1, the behavior
5657 of 5.5 is unchanged from old versions of Squid (i.e. a
5658 forced refresh is impossible). Newer versions of IE will,
5659 hopefully, continue to have the new behavior and will be
5660 handled based on that assumption. This option defaults to
5661 the old Squid behavior, which is better for hit ratios but
5662 worse for clients using IE, if they need to be able to
5663 force fresh content.
5666 NAME: vary_ignore_expire
5669 LOC: Config.onoff.vary_ignore_expire
5672 Many HTTP servers supporting Vary gives such objects
5673 immediate expiry time with no cache-control header
5674 when requested by a HTTP/1.0 client. This option
5675 enables Squid to ignore such expiry times until
5676 HTTP/1.1 is fully implemented.
5678 WARNING: If turned on this may eventually cause some
5679 varying objects not intended for caching to get cached.
5682 NAME: request_entities
5684 LOC: Config.onoff.request_entities
5687 Squid defaults to deny GET and HEAD requests with request entities,
5688 as the meaning of such requests are undefined in the HTTP standard
5689 even if not explicitly forbidden.
5691 Set this directive to on if you have clients which insists
5692 on sending request entities in GET or HEAD requests. But be warned
5693 that there is server software (both proxies and web servers) which
5694 can fail to properly process this kind of request which may make you
5695 vulnerable to cache pollution attacks if enabled.
5698 NAME: request_header_access
5699 IFDEF: USE_HTTP_VIOLATIONS
5700 TYPE: http_header_access
5701 LOC: Config.request_header_access
5703 DEFAULT_DOC: No limits.
5705 Usage: request_header_access header_name allow|deny [!]aclname ...
5707 WARNING: Doing this VIOLATES the HTTP standard. Enabling
5708 this feature could make you liable for problems which it
5711 This option replaces the old 'anonymize_headers' and the
5712 older 'http_anonymizer' option with something that is much
5713 more configurable. A list of ACLs for each header name allows
5714 removal of specific header fields under specific conditions.
5716 This option only applies to outgoing HTTP request headers (i.e.,
5717 headers sent by Squid to the next HTTP hop such as a cache peer
5718 or an origin server). The option has no effect during cache hit
5719 detection. The equivalent adaptation vectoring point in ICAP
5720 terminology is post-cache REQMOD.
5722 The option is applied to individual outgoing request header
5723 fields. For each request header field F, Squid uses the first
5724 qualifying sets of request_header_access rules:
5726 1. Rules with header_name equal to F's name.
5727 2. Rules with header_name 'Other', provided F's name is not
5728 on the hard-coded list of commonly used HTTP header names.
5729 3. Rules with header_name 'All'.
5731 Within that qualifying rule set, rule ACLs are checked as usual.
5732 If ACLs of an "allow" rule match, the header field is allowed to
5733 go through as is. If ACLs of a "deny" rule match, the header is
5734 removed and request_header_replace is then checked to identify
5735 if the removed header has a replacement. If no rules within the
5736 set have matching ACLs, the header field is left as is.
5738 For example, to achieve the same behavior as the old
5739 'http_anonymizer standard' option, you should use:
5741 request_header_access From deny all
5742 request_header_access Referer deny all
5743 request_header_access User-Agent deny all
5745 Or, to reproduce the old 'http_anonymizer paranoid' feature
5748 request_header_access Authorization allow all
5749 request_header_access Proxy-Authorization allow all
5750 request_header_access Cache-Control allow all
5751 request_header_access Content-Length allow all
5752 request_header_access Content-Type allow all
5753 request_header_access Date allow all
5754 request_header_access Host allow all
5755 request_header_access If-Modified-Since allow all
5756 request_header_access Pragma allow all
5757 request_header_access Accept allow all
5758 request_header_access Accept-Charset allow all
5759 request_header_access Accept-Encoding allow all
5760 request_header_access Accept-Language allow all
5761 request_header_access Connection allow all
5762 request_header_access All deny all
5764 HTTP reply headers are controlled with the reply_header_access directive.
5766 By default, all headers are allowed (no anonymizing is performed).
5769 NAME: reply_header_access
5770 IFDEF: USE_HTTP_VIOLATIONS
5771 TYPE: http_header_access
5772 LOC: Config.reply_header_access
5774 DEFAULT_DOC: No limits.
5776 Usage: reply_header_access header_name allow|deny [!]aclname ...
5778 WARNING: Doing this VIOLATES the HTTP standard. Enabling
5779 this feature could make you liable for problems which it
5782 This option only applies to reply headers, i.e., from the
5783 server to the client.
5785 This is the same as request_header_access, but in the other
5786 direction. Please see request_header_access for detailed
5789 For example, to achieve the same behavior as the old
5790 'http_anonymizer standard' option, you should use:
5792 reply_header_access Server deny all
5793 reply_header_access WWW-Authenticate deny all
5794 reply_header_access Link deny all
5796 Or, to reproduce the old 'http_anonymizer paranoid' feature
5799 reply_header_access Allow allow all
5800 reply_header_access WWW-Authenticate allow all
5801 reply_header_access Proxy-Authenticate allow all
5802 reply_header_access Cache-Control allow all
5803 reply_header_access Content-Encoding allow all
5804 reply_header_access Content-Length allow all
5805 reply_header_access Content-Type allow all
5806 reply_header_access Date allow all
5807 reply_header_access Expires allow all
5808 reply_header_access Last-Modified allow all
5809 reply_header_access Location allow all
5810 reply_header_access Pragma allow all
5811 reply_header_access Content-Language allow all
5812 reply_header_access Retry-After allow all
5813 reply_header_access Title allow all
5814 reply_header_access Content-Disposition allow all
5815 reply_header_access Connection allow all
5816 reply_header_access All deny all
5818 HTTP request headers are controlled with the request_header_access directive.
5820 By default, all headers are allowed (no anonymizing is
5824 NAME: request_header_replace header_replace
5825 IFDEF: USE_HTTP_VIOLATIONS
5826 TYPE: http_header_replace
5827 LOC: Config.request_header_access
5830 Usage: request_header_replace header_name message
5831 Example: request_header_replace User-Agent Nutscrape/1.0 (CP/M; 8-bit)
5833 This option allows you to change the contents of headers
5834 denied with request_header_access above, by replacing them
5835 with some fixed string.
5837 This only applies to request headers, not reply headers.
5839 By default, headers are removed if denied.
5842 NAME: reply_header_replace
5843 IFDEF: USE_HTTP_VIOLATIONS
5844 TYPE: http_header_replace
5845 LOC: Config.reply_header_access
5848 Usage: reply_header_replace header_name message
5849 Example: reply_header_replace Server Foo/1.0
5851 This option allows you to change the contents of headers
5852 denied with reply_header_access above, by replacing them
5853 with some fixed string.
5855 This only applies to reply headers, not request headers.
5857 By default, headers are removed if denied.
5860 NAME: request_header_add
5861 TYPE: HeaderWithAclList
5862 LOC: Config.request_header_add
5865 Usage: request_header_add field-name field-value acl1 [acl2] ...
5866 Example: request_header_add X-Client-CA "CA=%ssl::>cert_issuer" all
5868 This option adds header fields to outgoing HTTP requests (i.e.,
5869 request headers sent by Squid to the next HTTP hop such as a
5870 cache peer or an origin server). The option has no effect during
5871 cache hit detection. The equivalent adaptation vectoring point
5872 in ICAP terminology is post-cache REQMOD.
5874 Field-name is a token specifying an HTTP header name. If a
5875 standard HTTP header name is used, Squid does not check whether
5876 the new header conflicts with any existing headers or violates
5877 HTTP rules. If the request to be modified already contains a
5878 field with the same name, the old field is preserved but the
5879 header field values are not merged.
5881 Field-value is either a token or a quoted string. If quoted
5882 string format is used, then the surrounding quotes are removed
5883 while escape sequences and %macros are processed.
5885 In theory, all of the logformat codes can be used as %macros.
5886 However, unlike logging (which happens at the very end of
5887 transaction lifetime), the transaction may not yet have enough
5888 information to expand a macro when the new header value is needed.
5889 And some information may already be available to Squid but not yet
5890 committed where the macro expansion code can access it (report
5891 such instances!). The macro will be expanded into a single dash
5892 ('-') in such cases. Not all macros have been tested.
5894 One or more Squid ACLs may be specified to restrict header
5895 injection to matching requests. As always in squid.conf, all
5896 ACLs in an option ACL list must be satisfied for the insertion
5897 to happen. The request_header_add option supports fast ACLs
5906 This option used to log custom information about the master
5907 transaction. For example, an admin may configure Squid to log
5908 which "user group" the transaction belongs to, where "user group"
5909 will be determined based on a set of ACLs and not [just]
5910 authentication information.
5911 Values of key/value pairs can be logged using %{key}note macros:
5913 note key value acl ...
5914 logformat myFormat ... %{key}note ...
5917 NAME: relaxed_header_parser
5918 COMMENT: on|off|warn
5920 LOC: Config.onoff.relaxed_header_parser
5923 In the default "on" setting Squid accepts certain forms
5924 of non-compliant HTTP messages where it is unambiguous
5925 what the sending application intended even if the message
5926 is not correctly formatted. The messages is then normalized
5927 to the correct form when forwarded by Squid.
5929 If set to "warn" then a warning will be emitted in cache.log
5930 each time such HTTP error is encountered.
5932 If set to "off" then such HTTP errors will cause the request
5933 or response to be rejected.
5936 NAME: collapsed_forwarding
5939 LOC: Config.onoff.collapsed_forwarding
5942 This option controls whether Squid is allowed to merge multiple
5943 potentially cachable requests for the same URI before Squid knows
5944 whether the response is going to be cachable.
5946 This feature is disabled by default: Enabling collapsed forwarding
5947 needlessly delays forwarding requests that look cachable (when they are
5948 collapsed) but then need to be forwarded individually anyway because
5949 they end up being for uncachable content. However, in some cases, such
5950 as accelleration of highly cachable content with periodic or groupped
5951 expiration times, the gains from collapsing [large volumes of
5952 simultenous refresh requests] outweigh losses from such delays.
5957 -----------------------------------------------------------------------------
5960 NAME: forward_timeout
5963 LOC: Config.Timeout.forward
5966 This parameter specifies how long Squid should at most attempt in
5967 finding a forwarding path for the request before giving up.
5970 NAME: connect_timeout
5973 LOC: Config.Timeout.connect
5976 This parameter specifies how long to wait for the TCP connect to
5977 the requested server or peer to complete before Squid should
5978 attempt to find another path where to forward the request.
5981 NAME: peer_connect_timeout
5984 LOC: Config.Timeout.peer_connect
5987 This parameter specifies how long to wait for a pending TCP
5988 connection to a peer cache. The default is 30 seconds. You
5989 may also set different timeout values for individual neighbors
5990 with the 'connect-timeout' option on a 'cache_peer' line.
5996 LOC: Config.Timeout.read
5999 Applied on peer server connections.
6001 After each successful read(), the timeout will be extended by this
6002 amount. If no data is read again after this amount of time,
6003 the request is aborted and logged with ERR_READ_TIMEOUT.
6005 The default is 15 minutes.
6011 LOC: Config.Timeout.write
6014 This timeout is tracked for all connections that have data
6015 available for writing and are waiting for the socket to become
6016 ready. After each successful write, the timeout is extended by
6017 the configured amount. If Squid has data to write but the
6018 connection is not ready for the configured duration, the
6019 transaction associated with the connection is terminated. The
6020 default is 15 minutes.
6023 NAME: request_timeout
6025 LOC: Config.Timeout.request
6028 How long to wait for complete HTTP request headers after initial
6029 connection establishment.
6032 NAME: client_idle_pconn_timeout persistent_request_timeout
6034 LOC: Config.Timeout.clientIdlePconn
6037 How long to wait for the next HTTP request on a persistent
6038 client connection after the previous request completes.
6041 NAME: ftp_client_idle_timeout
6043 LOC: Config.Timeout.ftpClientIdle
6046 How long to wait for an FTP request on a connection to Squid ftp_port.
6047 Many FTP clients do not deal with idle connection closures well,
6048 necessitating a longer default timeout than client_idle_pconn_timeout
6049 used for incoming HTTP requests.
6052 NAME: client_lifetime
6055 LOC: Config.Timeout.lifetime
6058 The maximum amount of time a client (browser) is allowed to
6059 remain connected to the cache process. This protects the Cache
6060 from having a lot of sockets (and hence file descriptors) tied up
6061 in a CLOSE_WAIT state from remote clients that go away without
6062 properly shutting down (either because of a network failure or
6063 because of a poor client implementation). The default is one
6066 NOTE: The default value is intended to be much larger than any
6067 client would ever need to be connected to your cache. You
6068 should probably change client_lifetime only as a last resort.
6069 If you seem to have many client connections tying up
6070 filedescriptors, we recommend first tuning the read_timeout,
6071 request_timeout, persistent_request_timeout and quick_abort values.
6074 NAME: half_closed_clients
6076 LOC: Config.onoff.half_closed_clients
6079 Some clients may shutdown the sending side of their TCP
6080 connections, while leaving their receiving sides open. Sometimes,
6081 Squid can not tell the difference between a half-closed and a
6082 fully-closed TCP connection.
6084 By default, Squid will immediately close client connections when
6085 read(2) returns "no more data to read."
6087 Change this option to 'on' and Squid will keep open connections
6088 until a read(2) or write(2) on the socket returns an error.
6089 This may show some benefits for reverse proxies. But if not
6090 it is recommended to leave OFF.
6093 NAME: server_idle_pconn_timeout pconn_timeout
6095 LOC: Config.Timeout.serverIdlePconn
6098 Timeout for idle persistent connections to servers and other
6105 LOC: Ident::TheConfig.timeout
6108 Maximum time to wait for IDENT lookups to complete.
6110 If this is too high, and you enabled IDENT lookups from untrusted
6111 users, you might be susceptible to denial-of-service by having
6112 many ident requests going at once.
6115 NAME: shutdown_lifetime
6118 LOC: Config.shutdownLifetime
6121 When SIGTERM or SIGHUP is received, the cache is put into
6122 "shutdown pending" mode until all active sockets are closed.
6123 This value is the lifetime to set for all open descriptors
6124 during shutdown mode. Any active clients after this many
6125 seconds will receive a 'timeout' message.
6129 ADMINISTRATIVE PARAMETERS
6130 -----------------------------------------------------------------------------
6136 LOC: Config.adminEmail
6138 Email-address of local cache manager who will receive
6139 mail if the cache dies. The default is "webmaster".
6145 LOC: Config.EmailFrom
6147 From: email-address for mail sent when the cache dies.
6148 The default is to use 'squid@unique_hostname'.
6150 See also: unique_hostname directive.
6156 LOC: Config.EmailProgram
6158 Email program used to send mail if the cache dies.
6159 The default is "mail". The specified program must comply
6160 with the standard Unix mail syntax:
6161 mail-program recipient < mailfile
6163 Optional command line options can be specified.
6166 NAME: cache_effective_user
6168 DEFAULT: @DEFAULT_CACHE_EFFECTIVE_USER@
6169 LOC: Config.effectiveUser
6171 If you start Squid as root, it will change its effective/real
6172 UID/GID to the user specified below. The default is to change
6173 to UID of @DEFAULT_CACHE_EFFECTIVE_USER@.
6174 see also; cache_effective_group
6177 NAME: cache_effective_group
6180 DEFAULT_DOC: Use system group memberships of the cache_effective_user account
6181 LOC: Config.effectiveGroup
6183 Squid sets the GID to the effective user's default group ID
6184 (taken from the password file) and supplementary group list
6185 from the groups membership.
6187 If you want Squid to run with a specific GID regardless of
6188 the group memberships of the effective user then set this
6189 to the group (or GID) you want Squid to run as. When set
6190 all other group privileges of the effective user are ignored
6191 and only this GID is effective. If Squid is not started as
6192 root the user starting Squid MUST be member of the specified
6195 This option is not recommended by the Squid Team.
6196 Our preference is for administrators to configure a secure
6197 user account for squid with UID/GID matching system policies.
6200 NAME: httpd_suppress_version_string
6204 LOC: Config.onoff.httpd_suppress_version_string
6206 Suppress Squid version string info in HTTP headers and HTML error pages.
6209 NAME: visible_hostname
6211 LOC: Config.visibleHostname
6213 DEFAULT_DOC: Automatically detect the system host name
6215 If you want to present a special hostname in error messages, etc,
6216 define this. Otherwise, the return value of gethostname()
6217 will be used. If you have multiple caches in a cluster and
6218 get errors about IP-forwarding you must set them to have individual
6219 names with this setting.
6222 NAME: unique_hostname
6224 LOC: Config.uniqueHostname
6226 DEFAULT_DOC: Copy the value from visible_hostname
6228 If you want to have multiple machines with the same
6229 'visible_hostname' you must give each machine a different
6230 'unique_hostname' so forwarding loops can be detected.
6233 NAME: hostname_aliases
6235 LOC: Config.hostnameAliases
6238 A list of other DNS names your cache has.
6246 Minimum umask which should be enforced while the proxy
6247 is running, in addition to the umask set at startup.
6249 For a traditional octal representation of umasks, start
6254 OPTIONS FOR THE CACHE REGISTRATION SERVICE
6255 -----------------------------------------------------------------------------
6257 This section contains parameters for the (optional) cache
6258 announcement service. This service is provided to help
6259 cache administrators locate one another in order to join or
6260 create cache hierarchies.
6262 An 'announcement' message is sent (via UDP) to the registration
6263 service by Squid. By default, the announcement message is NOT
6264 SENT unless you enable it with 'announce_period' below.
6266 The announcement message includes your hostname, plus the
6267 following information from this configuration file:
6273 All current information is processed regularly and made
6274 available on the Web at http://www.ircache.net/Cache/Tracker/.
6277 NAME: announce_period
6279 LOC: Config.Announce.period
6281 DEFAULT_DOC: Announcement messages disabled.
6283 This is how frequently to send cache announcements.
6285 To enable announcing your cache, just set an announce period.
6288 announce_period 1 day
6293 DEFAULT: tracker.ircache.net
6294 LOC: Config.Announce.host
6296 Set the hostname where announce registration messages will be sent.
6298 See also announce_port and announce_file
6304 LOC: Config.Announce.file
6306 The contents of this file will be included in the announce
6307 registration messages.
6313 LOC: Config.Announce.port
6315 Set the port where announce registration messages will be sent.
6317 See also announce_host and announce_file
6321 HTTPD-ACCELERATOR OPTIONS
6322 -----------------------------------------------------------------------------
6325 NAME: httpd_accel_surrogate_id
6328 DEFAULT_DOC: visible_hostname is used if no specific ID is set.
6329 LOC: Config.Accel.surrogate_id
6331 Surrogates (http://www.esi.org/architecture_spec_1.0.html)
6332 need an identification token to allow control targeting. Because
6333 a farm of surrogates may all perform the same tasks, they may share
6334 an identification token.
6337 NAME: http_accel_surrogate_remote
6341 LOC: Config.onoff.surrogate_is_remote
6343 Remote surrogates (such as those in a CDN) honour the header
6344 "Surrogate-Control: no-store-remote".
6346 Set this to on to have squid behave as a remote surrogate.
6350 IFDEF: USE_SQUID_ESI
6351 COMMENT: libxml2|expat|custom
6353 LOC: ESIParser::Type
6356 ESI markup is not strictly XML compatible. The custom ESI parser
6357 will give higher performance, but cannot handle non ASCII character
6362 DELAY POOL PARAMETERS
6363 -----------------------------------------------------------------------------
6367 TYPE: delay_pool_count
6369 IFDEF: USE_DELAY_POOLS
6372 This represents the number of delay pools to be used. For example,
6373 if you have one class 2 delay pool and one class 3 delays pool, you
6374 have a total of 2 delay pools.
6376 See also delay_parameters, delay_class, delay_access for pool
6377 configuration details.
6381 TYPE: delay_pool_class
6383 IFDEF: USE_DELAY_POOLS
6386 This defines the class of each delay pool. There must be exactly one
6387 delay_class line for each delay pool. For example, to define two
6388 delay pools, one of class 2 and one of class 3, the settings above
6392 delay_pools 4 # 4 delay pools
6393 delay_class 1 2 # pool 1 is a class 2 pool
6394 delay_class 2 3 # pool 2 is a class 3 pool
6395 delay_class 3 4 # pool 3 is a class 4 pool
6396 delay_class 4 5 # pool 4 is a class 5 pool
6398 The delay pool classes are:
6400 class 1 Everything is limited by a single aggregate
6403 class 2 Everything is limited by a single aggregate
6404 bucket as well as an "individual" bucket chosen
6405 from bits 25 through 32 of the IPv4 address.
6407 class 3 Everything is limited by a single aggregate
6408 bucket as well as a "network" bucket chosen
6409 from bits 17 through 24 of the IP address and a
6410 "individual" bucket chosen from bits 17 through
6411 32 of the IPv4 address.
6413 class 4 Everything in a class 3 delay pool, with an
6414 additional limit on a per user basis. This
6415 only takes effect if the username is established
6416 in advance - by forcing authentication in your
6419 class 5 Requests are grouped according their tag (see
6420 external_acl's tag= reply).
6423 Each pool also requires a delay_parameters directive to configure the pool size
6424 and speed limits used whenever the pool is applied to a request. Along with
6425 a set of delay_access directives to determine when it is used.
6427 NOTE: If an IP address is a.b.c.d
6428 -> bits 25 through 32 are "d"
6429 -> bits 17 through 24 are "c"
6430 -> bits 17 through 32 are "c * 256 + d"
6432 NOTE-2: Due to the use of bitmasks in class 2,3,4 pools they only apply to
6433 IPv4 traffic. Class 1 and 5 pools may be used with IPv6 traffic.
6435 This clause only supports fast acl types.
6436 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
6438 See also delay_parameters and delay_access.
6442 TYPE: delay_pool_access
6444 DEFAULT_DOC: Deny using the pool, unless allow rules exist in squid.conf for the pool.
6445 IFDEF: USE_DELAY_POOLS
6448 This is used to determine which delay pool a request falls into.
6450 delay_access is sorted per pool and the matching starts with pool 1,
6451 then pool 2, ..., and finally pool N. The first delay pool where the
6452 request is allowed is selected for the request. If it does not allow
6453 the request to any pool then the request is not delayed (default).
6455 For example, if you want some_big_clients in delay
6456 pool 1 and lotsa_little_clients in delay pool 2:
6458 delay_access 1 allow some_big_clients
6459 delay_access 1 deny all
6460 delay_access 2 allow lotsa_little_clients
6461 delay_access 2 deny all
6462 delay_access 3 allow authenticated_clients
6464 See also delay_parameters and delay_class.
6468 NAME: delay_parameters
6469 TYPE: delay_pool_rates
6471 IFDEF: USE_DELAY_POOLS
6474 This defines the parameters for a delay pool. Each delay pool has
6475 a number of "buckets" associated with it, as explained in the
6476 description of delay_class.
6478 For a class 1 delay pool, the syntax is:
6480 delay_parameters pool aggregate
6482 For a class 2 delay pool:
6484 delay_parameters pool aggregate individual
6486 For a class 3 delay pool:
6488 delay_parameters pool aggregate network individual
6490 For a class 4 delay pool:
6492 delay_parameters pool aggregate network individual user
6494 For a class 5 delay pool:
6496 delay_parameters pool tagrate
6498 The option variables are:
6500 pool a pool number - ie, a number between 1 and the
6501 number specified in delay_pools as used in
6504 aggregate the speed limit parameters for the aggregate bucket
6507 individual the speed limit parameters for the individual
6508 buckets (class 2, 3).
6510 network the speed limit parameters for the network buckets
6513 user the speed limit parameters for the user buckets
6516 tagrate the speed limit parameters for the tag buckets
6519 A pair of delay parameters is written restore/maximum, where restore is
6520 the number of bytes (not bits - modem and network speeds are usually
6521 quoted in bits) per second placed into the bucket, and maximum is the
6522 maximum number of bytes which can be in the bucket at any time.
6524 There must be one delay_parameters line for each delay pool.
6527 For example, if delay pool number 1 is a class 2 delay pool as in the
6528 above example, and is being used to strictly limit each host to 64Kbit/sec
6529 (plus overheads), with no overall limit, the line is:
6531 delay_parameters 1 -1/-1 8000/8000
6533 Note that 8 x 8000 KByte/sec -> 64Kbit/sec.
6535 Note that the figure -1 is used to represent "unlimited".
6538 And, if delay pool number 2 is a class 3 delay pool as in the above
6539 example, and you want to limit it to a total of 256Kbit/sec (strict limit)
6540 with each 8-bit network permitted 64Kbit/sec (strict limit) and each
6541 individual host permitted 4800bit/sec with a bucket maximum size of 64Kbits
6542 to permit a decent web page to be downloaded at a decent speed
6543 (if the network is not being limited due to overuse) but slow down
6544 large downloads more significantly:
6546 delay_parameters 2 32000/32000 8000/8000 600/8000
6548 Note that 8 x 32000 KByte/sec -> 256Kbit/sec.
6549 8 x 8000 KByte/sec -> 64Kbit/sec.
6550 8 x 600 Byte/sec -> 4800bit/sec.
6553 Finally, for a class 4 delay pool as in the example - each user will
6554 be limited to 128Kbits/sec no matter how many workstations they are logged into.:
6556 delay_parameters 4 32000/32000 8000/8000 600/64000 16000/16000
6559 See also delay_class and delay_access.
6563 NAME: delay_initial_bucket_level
6564 COMMENT: (percent, 0-100)
6567 IFDEF: USE_DELAY_POOLS
6568 LOC: Config.Delay.initial
6570 The initial bucket percentage is used to determine how much is put
6571 in each bucket when squid starts, is reconfigured, or first notices
6572 a host accessing it (in class 2 and class 3, individual hosts and
6573 networks only have buckets associated with them once they have been
6578 CLIENT DELAY POOL PARAMETERS
6579 -----------------------------------------------------------------------------
6582 NAME: client_delay_pools
6583 TYPE: client_delay_pool_count
6585 IFDEF: USE_DELAY_POOLS
6586 LOC: Config.ClientDelay
6588 This option specifies the number of client delay pools used. It must
6589 preceed other client_delay_* options.
6592 client_delay_pools 2
6594 See also client_delay_parameters and client_delay_access.
6597 NAME: client_delay_initial_bucket_level
6598 COMMENT: (percent, 0-no_limit)
6601 IFDEF: USE_DELAY_POOLS
6602 LOC: Config.ClientDelay.initial
6604 This option determines the initial bucket size as a percentage of
6605 max_bucket_size from client_delay_parameters. Buckets are created
6606 at the time of the "first" connection from the matching IP. Idle
6607 buckets are periodically deleted up.
6609 You can specify more than 100 percent but note that such "oversized"
6610 buckets are not refilled until their size goes down to max_bucket_size
6611 from client_delay_parameters.
6614 client_delay_initial_bucket_level 50
6617 NAME: client_delay_parameters
6618 TYPE: client_delay_pool_rates
6620 IFDEF: USE_DELAY_POOLS
6621 LOC: Config.ClientDelay
6624 This option configures client-side bandwidth limits using the
6627 client_delay_parameters pool speed_limit max_bucket_size
6629 pool is an integer ID used for client_delay_access matching.
6631 speed_limit is bytes added to the bucket per second.
6633 max_bucket_size is the maximum size of a bucket, enforced after any
6634 speed_limit additions.
6636 Please see the delay_parameters option for more information and
6640 client_delay_parameters 1 1024 2048
6641 client_delay_parameters 2 51200 16384
6643 See also client_delay_access.
6647 NAME: client_delay_access
6648 TYPE: client_delay_pool_access
6650 DEFAULT_DOC: Deny use of the pool, unless allow rules exist in squid.conf for the pool.
6651 IFDEF: USE_DELAY_POOLS
6652 LOC: Config.ClientDelay
6654 This option determines the client-side delay pool for the
6657 client_delay_access pool_ID allow|deny acl_name
6659 All client_delay_access options are checked in their pool ID
6660 order, starting with pool 1. The first checked pool with allowed
6661 request is selected for the request. If no ACL matches or there
6662 are no client_delay_access options, the request bandwidth is not
6665 The ACL-selected pool is then used to find the
6666 client_delay_parameters for the request. Client-side pools are
6667 not used to aggregate clients. Clients are always aggregated
6668 based on their source IP addresses (one bucket per source IP).
6670 This clause only supports fast acl types.
6671 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
6672 Additionally, only the client TCP connection details are available.
6673 ACLs testing HTTP properties will not work.
6675 Please see delay_access for more examples.
6678 client_delay_access 1 allow low_rate_network
6679 client_delay_access 2 allow vips_network
6682 See also client_delay_parameters and client_delay_pools.
6686 WCCPv1 AND WCCPv2 CONFIGURATION OPTIONS
6687 -----------------------------------------------------------------------------
6692 LOC: Config.Wccp.router
6694 DEFAULT_DOC: WCCP disabled.
6697 Use this option to define your WCCP ``home'' router for
6700 wccp_router supports a single WCCP(v1) router
6702 wccp2_router supports multiple WCCPv2 routers
6704 only one of the two may be used at the same time and defines
6705 which version of WCCP to use.
6709 TYPE: IpAddress_list
6710 LOC: Config.Wccp2.router
6712 DEFAULT_DOC: WCCPv2 disabled.
6715 Use this option to define your WCCP ``home'' router for
6718 wccp_router supports a single WCCP(v1) router
6720 wccp2_router supports multiple WCCPv2 routers
6722 only one of the two may be used at the same time and defines
6723 which version of WCCP to use.
6728 LOC: Config.Wccp.version
6732 This directive is only relevant if you need to set up WCCP(v1)
6733 to some very old and end-of-life Cisco routers. In all other
6734 setups it must be left unset or at the default setting.
6735 It defines an internal version in the WCCP(v1) protocol,
6736 with version 4 being the officially documented protocol.
6738 According to some users, Cisco IOS 11.2 and earlier only
6739 support WCCP version 3. If you're using that or an earlier
6740 version of IOS, you may need to change this value to 3, otherwise
6741 do not specify this parameter.
6744 NAME: wccp2_rebuild_wait
6746 LOC: Config.Wccp2.rebuildwait
6750 If this is enabled Squid will wait for the cache dir rebuild to finish
6751 before sending the first wccp2 HereIAm packet
6754 NAME: wccp2_forwarding_method
6756 LOC: Config.Wccp2.forwarding_method
6760 WCCP2 allows the setting of forwarding methods between the
6761 router/switch and the cache. Valid values are as follows:
6763 gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
6764 l2 - L2 redirect (forward the packet using Layer 2/MAC rewriting)
6766 Currently (as of IOS 12.4) cisco routers only support GRE.
6767 Cisco switches only support the L2 redirect assignment method.
6770 NAME: wccp2_return_method
6772 LOC: Config.Wccp2.return_method
6776 WCCP2 allows the setting of return methods between the
6777 router/switch and the cache for packets that the cache
6778 decides not to handle. Valid values are as follows:
6780 gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
6781 l2 - L2 redirect (forward the packet using Layer 2/MAC rewriting)
6783 Currently (as of IOS 12.4) cisco routers only support GRE.
6784 Cisco switches only support the L2 redirect assignment.
6786 If the "ip wccp redirect exclude in" command has been
6787 enabled on the cache interface, then it is still safe for
6788 the proxy server to use a l2 redirect method even if this
6789 option is set to GRE.
6792 NAME: wccp2_assignment_method
6794 LOC: Config.Wccp2.assignment_method
6798 WCCP2 allows the setting of methods to assign the WCCP hash
6799 Valid values are as follows:
6801 hash - Hash assignment
6802 mask - Mask assignment
6804 As a general rule, cisco routers support the hash assignment method
6805 and cisco switches support the mask assignment method.
6810 LOC: Config.Wccp2.info
6811 DEFAULT_IF_NONE: standard 0
6812 DEFAULT_DOC: Use the 'web-cache' standard service.
6815 WCCP2 allows for multiple traffic services. There are two
6816 types: "standard" and "dynamic". The standard type defines
6817 one service id - http (id 0). The dynamic service ids can be from
6818 51 to 255 inclusive. In order to use a dynamic service id
6819 one must define the type of traffic to be redirected; this is done
6820 using the wccp2_service_info option.
6822 The "standard" type does not require a wccp2_service_info option,
6823 just specifying the service id will suffice.
6825 MD5 service authentication can be enabled by adding
6826 "password=<password>" to the end of this service declaration.
6830 wccp2_service standard 0 # for the 'web-cache' standard service
6831 wccp2_service dynamic 80 # a dynamic service type which will be
6832 # fleshed out with subsequent options.
6833 wccp2_service standard 0 password=foo
6836 NAME: wccp2_service_info
6837 TYPE: wccp2_service_info
6838 LOC: Config.Wccp2.info
6842 Dynamic WCCPv2 services require further information to define the
6843 traffic you wish to have diverted.
6847 wccp2_service_info <id> protocol=<protocol> flags=<flag>,<flag>..
6848 priority=<priority> ports=<port>,<port>..
6850 The relevant WCCPv2 flags:
6851 + src_ip_hash, dst_ip_hash
6852 + source_port_hash, dst_port_hash
6853 + src_ip_alt_hash, dst_ip_alt_hash
6854 + src_port_alt_hash, dst_port_alt_hash
6857 The port list can be one to eight entries.
6861 wccp2_service_info 80 protocol=tcp flags=src_ip_hash,ports_source
6862 priority=240 ports=80
6864 Note: the service id must have been defined by a previous
6865 'wccp2_service dynamic <id>' entry.
6870 LOC: Config.Wccp2.weight
6874 Each cache server gets assigned a set of the destination
6875 hash proportional to their weight.
6880 LOC: Config.Wccp.address
6882 DEFAULT_DOC: Address selected by the operating system.
6885 Use this option if you require WCCPv2 to use a specific
6888 The default behavior is to not bind to any specific address.
6893 LOC: Config.Wccp2.address
6895 DEFAULT_DOC: Address selected by the operating system.
6898 Use this option if you require WCCP to use a specific
6901 The default behavior is to not bind to any specific address.
6905 PERSISTENT CONNECTION HANDLING
6906 -----------------------------------------------------------------------------
6908 Also see "pconn_timeout" in the TIMEOUTS section
6911 NAME: client_persistent_connections
6913 LOC: Config.onoff.client_pconns
6916 Persistent connection support for clients.
6917 Squid uses persistent connections (when allowed). You can use
6918 this option to disable persistent connections with clients.
6921 NAME: server_persistent_connections
6923 LOC: Config.onoff.server_pconns
6926 Persistent connection support for servers.
6927 Squid uses persistent connections (when allowed). You can use
6928 this option to disable persistent connections with servers.
6931 NAME: persistent_connection_after_error
6933 LOC: Config.onoff.error_pconns
6936 With this directive the use of persistent connections after
6937 HTTP errors can be disabled. Useful if you have clients
6938 who fail to handle errors on persistent connections proper.
6941 NAME: detect_broken_pconn
6943 LOC: Config.onoff.detect_broken_server_pconns
6946 Some servers have been found to incorrectly signal the use
6947 of HTTP/1.0 persistent connections even on replies not
6948 compatible, causing significant delays. This server problem
6949 has mostly been seen on redirects.
6951 By enabling this directive Squid attempts to detect such
6952 broken replies and automatically assume the reply is finished
6953 after 10 seconds timeout.
6957 CACHE DIGEST OPTIONS
6958 -----------------------------------------------------------------------------
6961 NAME: digest_generation
6962 IFDEF: USE_CACHE_DIGESTS
6964 LOC: Config.onoff.digest_generation
6967 This controls whether the server will generate a Cache Digest
6968 of its contents. By default, Cache Digest generation is
6969 enabled if Squid is compiled with --enable-cache-digests defined.
6972 NAME: digest_bits_per_entry
6973 IFDEF: USE_CACHE_DIGESTS
6975 LOC: Config.digest.bits_per_entry
6978 This is the number of bits of the server's Cache Digest which
6979 will be associated with the Digest entry for a given HTTP
6980 Method and URL (public key) combination. The default is 5.
6983 NAME: digest_rebuild_period
6984 IFDEF: USE_CACHE_DIGESTS
6987 LOC: Config.digest.rebuild_period
6990 This is the wait time between Cache Digest rebuilds.
6993 NAME: digest_rewrite_period
6995 IFDEF: USE_CACHE_DIGESTS
6997 LOC: Config.digest.rewrite_period
7000 This is the wait time between Cache Digest writes to
7004 NAME: digest_swapout_chunk_size
7007 IFDEF: USE_CACHE_DIGESTS
7008 LOC: Config.digest.swapout_chunk_size
7011 This is the number of bytes of the Cache Digest to write to
7012 disk at a time. It defaults to 4096 bytes (4KB), the Squid
7016 NAME: digest_rebuild_chunk_percentage
7017 COMMENT: (percent, 0-100)
7018 IFDEF: USE_CACHE_DIGESTS
7020 LOC: Config.digest.rebuild_chunk_percentage
7023 This is the percentage of the Cache Digest to be scanned at a
7024 time. By default it is set to 10% of the Cache Digest.
7029 -----------------------------------------------------------------------------
7034 LOC: Config.Port.snmp
7036 DEFAULT_DOC: SNMP disabled.
7039 The port number where Squid listens for SNMP requests. To enable
7040 SNMP support set this to a suitable port number. Port number
7041 3401 is often used for the Squid SNMP agent. By default it's
7042 set to "0" (disabled)
7050 LOC: Config.accessList.snmp
7052 DEFAULT_DOC: Deny, unless rules exist in squid.conf.
7055 Allowing or denying access to the SNMP port.
7057 All access to the agent is denied by default.
7060 snmp_access allow|deny [!]aclname ...
7062 This clause only supports fast acl types.
7063 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
7066 snmp_access allow snmppublic localhost
7067 snmp_access deny all
7070 NAME: snmp_incoming_address
7072 LOC: Config.Addrs.snmp_incoming
7074 DEFAULT_DOC: Accept SNMP packets from all machine interfaces.
7077 Just like 'udp_incoming_address', but for the SNMP port.
7079 snmp_incoming_address is used for the SNMP socket receiving
7080 messages from SNMP agents.
7082 The default snmp_incoming_address is to listen on all
7083 available network interfaces.
7086 NAME: snmp_outgoing_address
7088 LOC: Config.Addrs.snmp_outgoing
7090 DEFAULT_DOC: Use snmp_incoming_address or an address selected by the operating system.
7093 Just like 'udp_outgoing_address', but for the SNMP port.
7095 snmp_outgoing_address is used for SNMP packets returned to SNMP
7098 If snmp_outgoing_address is not set it will use the same socket
7099 as snmp_incoming_address. Only change this if you want to have
7100 SNMP replies sent using another address than where this Squid
7101 listens for SNMP queries.
7103 NOTE, snmp_incoming_address and snmp_outgoing_address can not have
7104 the same value since they both use the same port.
7109 -----------------------------------------------------------------------------
7112 NAME: icp_port udp_port
7115 DEFAULT_DOC: ICP disabled.
7116 LOC: Config.Port.icp
7118 The port number where Squid sends and receives ICP queries to
7119 and from neighbor caches. The standard UDP port for ICP is 3130.
7122 icp_port @DEFAULT_ICP_PORT@
7129 DEFAULT_DOC: HTCP disabled.
7130 LOC: Config.Port.htcp
7132 The port number where Squid sends and receives HTCP queries to
7133 and from neighbor caches. To turn it on you want to set it to
7140 NAME: log_icp_queries
7144 LOC: Config.onoff.log_udp
7146 If set, ICP queries are logged to access.log. You may wish
7147 do disable this if your ICP load is VERY high to speed things
7148 up or to simplify log analysis.
7151 NAME: udp_incoming_address
7153 LOC:Config.Addrs.udp_incoming
7155 DEFAULT_DOC: Accept packets from all machine interfaces.
7157 udp_incoming_address is used for UDP packets received from other
7160 The default behavior is to not bind to any specific address.
7162 Only change this if you want to have all UDP queries received on
7163 a specific interface/address.
7165 NOTE: udp_incoming_address is used by the ICP, HTCP, and DNS
7166 modules. Altering it will affect all of them in the same manner.
7168 see also; udp_outgoing_address
7170 NOTE, udp_incoming_address and udp_outgoing_address can not
7171 have the same value since they both use the same port.
7174 NAME: udp_outgoing_address
7176 LOC: Config.Addrs.udp_outgoing
7178 DEFAULT_DOC: Use udp_incoming_address or an address selected by the operating system.
7180 udp_outgoing_address is used for UDP packets sent out to other
7183 The default behavior is to not bind to any specific address.
7185 Instead it will use the same socket as udp_incoming_address.
7186 Only change this if you want to have UDP queries sent using another
7187 address than where this Squid listens for UDP queries from other
7190 NOTE: udp_outgoing_address is used by the ICP, HTCP, and DNS
7191 modules. Altering it will affect all of them in the same manner.
7193 see also; udp_incoming_address
7195 NOTE, udp_incoming_address and udp_outgoing_address can not
7196 have the same value since they both use the same port.
7203 LOC: Config.onoff.icp_hit_stale
7205 If you want to return ICP_HIT for stale cache objects, set this
7206 option to 'on'. If you have sibling relationships with caches
7207 in other administrative domains, this should be 'off'. If you only
7208 have sibling relationships with caches under your control,
7209 it is probably okay to set this to 'on'.
7210 If set to 'on', your siblings should use the option "allow-miss"
7211 on their cache_peer lines for connecting to you.
7214 NAME: minimum_direct_hops
7217 LOC: Config.minDirectHops
7219 If using the ICMP pinging stuff, do direct fetches for sites
7220 which are no more than this many hops away.
7223 NAME: minimum_direct_rtt
7227 LOC: Config.minDirectRtt
7229 If using the ICMP pinging stuff, do direct fetches for sites
7230 which are no more than this many rtt milliseconds away.
7236 LOC: Config.Netdb.low
7238 The low water mark for the ICMP measurement database.
7240 Note: high watermark controlled by netdb_high directive.
7242 These watermarks are counts, not percents. The defaults are
7243 (low) 900 and (high) 1000. When the high water mark is
7244 reached, database entries will be deleted until the low
7251 LOC: Config.Netdb.high
7253 The high water mark for the ICMP measurement database.
7255 Note: low watermark controlled by netdb_low directive.
7257 These watermarks are counts, not percents. The defaults are
7258 (low) 900 and (high) 1000. When the high water mark is
7259 reached, database entries will be deleted until the low
7263 NAME: netdb_ping_period
7265 LOC: Config.Netdb.period
7268 The minimum period for measuring a site. There will be at
7269 least this much delay between successive pings to the same
7270 network. The default is five minutes.
7277 LOC: Config.onoff.query_icmp
7279 If you want to ask your peers to include ICMP data in their ICP
7280 replies, enable this option.
7282 If your peer has configured Squid (during compilation) with
7283 '--enable-icmp' that peer will send ICMP pings to origin server
7284 sites of the URLs it receives. If you enable this option the
7285 ICP replies from that peer will include the ICMP data (if available).
7286 Then, when choosing a parent cache, Squid will choose the parent with
7287 the minimal RTT to the origin server. When this happens, the
7288 hierarchy field of the access.log will be
7289 "CLOSEST_PARENT_MISS". This option is off by default.
7292 NAME: test_reachability
7296 LOC: Config.onoff.test_reachability
7298 When this is 'on', ICP MISS replies will be ICP_MISS_NOFETCH
7299 instead of ICP_MISS if the target host is NOT in the ICMP
7300 database, or has a zero RTT.
7303 NAME: icp_query_timeout
7306 DEFAULT_DOC: Dynamic detection.
7308 LOC: Config.Timeout.icp_query
7310 Normally Squid will automatically determine an optimal ICP
7311 query timeout value based on the round-trip-time of recent ICP
7312 queries. If you want to override the value determined by
7313 Squid, set this 'icp_query_timeout' to a non-zero value. This
7314 value is specified in MILLISECONDS, so, to use a 2-second
7315 timeout (the old default), you would write:
7317 icp_query_timeout 2000
7320 NAME: maximum_icp_query_timeout
7324 LOC: Config.Timeout.icp_query_max
7326 Normally the ICP query timeout is determined dynamically. But
7327 sometimes it can lead to very large values (say 5 seconds).
7328 Use this option to put an upper limit on the dynamic timeout
7329 value. Do NOT use this option to always use a fixed (instead
7330 of a dynamic) timeout value. To set a fixed timeout see the
7331 'icp_query_timeout' directive.
7334 NAME: minimum_icp_query_timeout
7338 LOC: Config.Timeout.icp_query_min
7340 Normally the ICP query timeout is determined dynamically. But
7341 sometimes it can lead to very small timeouts, even lower than
7342 the normal latency variance on your link due to traffic.
7343 Use this option to put an lower limit on the dynamic timeout
7344 value. Do NOT use this option to always use a fixed (instead
7345 of a dynamic) timeout value. To set a fixed timeout see the
7346 'icp_query_timeout' directive.
7349 NAME: background_ping_rate
7353 LOC: Config.backgroundPingRate
7355 Controls how often the ICP pings are sent to siblings that
7356 have background-ping set.
7360 MULTICAST ICP OPTIONS
7361 -----------------------------------------------------------------------------
7366 LOC: Config.mcast_group_list
7369 This tag specifies a list of multicast groups which your server
7370 should join to receive multicasted ICP queries.
7372 NOTE! Be very careful what you put here! Be sure you
7373 understand the difference between an ICP _query_ and an ICP
7374 _reply_. This option is to be set only if you want to RECEIVE
7375 multicast queries. Do NOT set this option to SEND multicast
7376 ICP (use cache_peer for that). ICP replies are always sent via
7377 unicast, so this option does not affect whether or not you will
7378 receive replies from multicast group members.
7380 You must be very careful to NOT use a multicast address which
7381 is already in use by another group of caches.
7383 If you are unsure about multicast, please read the Multicast
7384 chapter in the Squid FAQ (http://www.squid-cache.org/FAQ/).
7386 Usage: mcast_groups 239.128.16.128 224.0.1.20
7388 By default, Squid doesn't listen on any multicast groups.
7391 NAME: mcast_miss_addr
7392 IFDEF: MULTICAST_MISS_STREAM
7394 LOC: Config.mcast_miss.addr
7396 DEFAULT_DOC: disabled.
7398 If you enable this option, every "cache miss" URL will
7399 be sent out on the specified multicast address.
7401 Do not enable this option unless you are are absolutely
7402 certain you understand what you are doing.
7405 NAME: mcast_miss_ttl
7406 IFDEF: MULTICAST_MISS_STREAM
7408 LOC: Config.mcast_miss.ttl
7411 This is the time-to-live value for packets multicasted
7412 when multicasting off cache miss URLs is enabled. By
7413 default this is set to 'site scope', i.e. 16.
7416 NAME: mcast_miss_port
7417 IFDEF: MULTICAST_MISS_STREAM
7419 LOC: Config.mcast_miss.port
7422 This is the port number to be used in conjunction with
7426 NAME: mcast_miss_encode_key
7427 IFDEF: MULTICAST_MISS_STREAM
7429 LOC: Config.mcast_miss.encode_key
7430 DEFAULT: XXXXXXXXXXXXXXXX
7432 The URLs that are sent in the multicast miss stream are
7433 encrypted. This is the encryption key.
7436 NAME: mcast_icp_query_timeout
7440 LOC: Config.Timeout.mcast_icp_query
7442 For multicast peers, Squid regularly sends out ICP "probes" to
7443 count how many other peers are listening on the given multicast
7444 address. This value specifies how long Squid should wait to
7445 count all the replies. The default is 2000 msec, or 2
7450 INTERNAL ICON OPTIONS
7451 -----------------------------------------------------------------------------
7454 NAME: icon_directory
7456 LOC: Config.icons.directory
7457 DEFAULT: @DEFAULT_ICON_DIR@
7459 Where the icons are stored. These are normally kept in
7463 NAME: global_internal_static
7465 LOC: Config.onoff.global_internal_static
7468 This directive controls is Squid should intercept all requests for
7469 /squid-internal-static/ no matter which host the URL is requesting
7470 (default on setting), or if nothing special should be done for
7471 such URLs (off setting). The purpose of this directive is to make
7472 icons etc work better in complex cache hierarchies where it may
7473 not always be possible for all corners in the cache mesh to reach
7474 the server generating a directory listing.
7477 NAME: short_icon_urls
7479 LOC: Config.icons.use_short_names
7482 If this is enabled Squid will use short URLs for icons.
7483 If disabled it will revert to the old behavior of including
7484 it's own name and port in the URL.
7486 If you run a complex cache hierarchy with a mix of Squid and
7487 other proxies you may need to disable this directive.
7492 -----------------------------------------------------------------------------
7495 NAME: error_directory
7497 LOC: Config.errorDirectory
7499 DEFAULT_DOC: Send error pages in the clients preferred language
7501 If you wish to create your own versions of the default
7502 error files to customize them to suit your company copy
7503 the error/template files to another directory and point
7506 WARNING: This option will disable multi-language support
7507 on error pages if used.
7509 The squid developers are interested in making squid available in
7510 a wide variety of languages. If you are making translations for a
7511 language that Squid does not currently provide please consider
7512 contributing your translation back to the project.
7513 http://wiki.squid-cache.org/Translations
7515 The squid developers working on translations are happy to supply drop-in
7516 translated error files in exchange for any new language contributions.
7519 NAME: error_default_language
7520 IFDEF: USE_ERR_LOCALES
7522 LOC: Config.errorDefaultLanguage
7524 DEFAULT_DOC: Generate English language pages.
7526 Set the default language which squid will send error pages in
7527 if no existing translation matches the clients language
7530 If unset (default) generic English will be used.
7532 The squid developers are interested in making squid available in
7533 a wide variety of languages. If you are interested in making
7534 translations for any language see the squid wiki for details.
7535 http://wiki.squid-cache.org/Translations
7538 NAME: error_log_languages
7539 IFDEF: USE_ERR_LOCALES
7541 LOC: Config.errorLogMissingLanguages
7544 Log to cache.log what languages users are attempting to
7545 auto-negotiate for translations.
7547 Successful negotiations are not logged. Only failures
7548 have meaning to indicate that Squid may need an upgrade
7549 of its error page translations.
7552 NAME: err_page_stylesheet
7554 LOC: Config.errorStylesheet
7555 DEFAULT: @DEFAULT_CONFIG_DIR@/errorpage.css
7557 CSS Stylesheet to pattern the display of Squid default error pages.
7559 For information on CSS see http://www.w3.org/Style/CSS/
7564 LOC: Config.errHtmlText
7567 HTML text to include in error messages. Make this a "mailto"
7568 URL to your admin address, or maybe just a link to your
7569 organizations Web page.
7571 To include this in your error messages, you must rewrite
7572 the error template files (found in the "errors" directory).
7573 Wherever you want the 'err_html_text' line to appear,
7574 insert a %L tag in the error template file.
7577 NAME: email_err_data
7580 LOC: Config.onoff.emailErrData
7583 If enabled, information about the occurred error will be
7584 included in the mailto links of the ERR pages (if %W is set)
7585 so that the email body contains the data.
7586 Syntax is <A HREF="mailto:%w%W">%w</A>
7591 LOC: Config.denyInfoList
7594 Usage: deny_info err_page_name acl
7595 or deny_info http://... acl
7596 or deny_info TCP_RESET acl
7598 This can be used to return a ERR_ page for requests which
7599 do not pass the 'http_access' rules. Squid remembers the last
7600 acl it evaluated in http_access, and if a 'deny_info' line exists
7601 for that ACL Squid returns a corresponding error page.
7603 The acl is typically the last acl on the http_access deny line which
7604 denied access. The exceptions to this rule are:
7605 - When Squid needs to request authentication credentials. It's then
7606 the first authentication related acl encountered
7607 - When none of the http_access lines matches. It's then the last
7608 acl processed on the last http_access line.
7609 - When the decision to deny access was made by an adaptation service,
7610 the acl name is the corresponding eCAP or ICAP service_name.
7612 NP: If providing your own custom error pages with error_directory
7613 you may also specify them by your custom file name:
7614 Example: deny_info ERR_CUSTOM_ACCESS_DENIED bad_guys
7616 By defaut Squid will send "403 Forbidden". A different 4xx or 5xx
7617 may be specified by prefixing the file name with the code and a colon.
7618 e.g. 404:ERR_CUSTOM_ACCESS_DENIED
7620 Alternatively you can tell Squid to reset the TCP connection
7621 by specifying TCP_RESET.
7623 Or you can specify an error URL or URL pattern. The browsers will
7624 get redirected to the specified URL after formatting tags have
7625 been replaced. Redirect will be done with 302 or 307 according to
7626 HTTP/1.1 specs. A different 3xx code may be specified by prefixing
7627 the URL. e.g. 303:http://example.com/
7630 %a - username (if available. Password NOT included)
7633 %E - Error description
7635 %H - Request domain name
7636 %i - Client IP Address
7638 %o - Message result from external ACL helper
7639 %p - Request Port number
7640 %P - Request Protocol name
7641 %R - Request URL path
7642 %T - Timestamp in RFC 1123 format
7643 %U - Full canonical URL from client
7644 (HTTPS URLs terminate with *)
7645 %u - Full canonical URL from client
7646 %w - Admin email from squid.conf
7648 %% - Literal percent (%) code
7653 OPTIONS INFLUENCING REQUEST FORWARDING
7654 -----------------------------------------------------------------------------
7657 NAME: nonhierarchical_direct
7659 LOC: Config.onoff.nonhierarchical_direct
7662 By default, Squid will send any non-hierarchical requests
7663 (not cacheable request type) direct to origin servers.
7665 When this is set to "off", Squid will prefer to send these
7666 requests to parents.
7668 Note that in most configurations, by turning this off you will only
7669 add latency to these request without any improvement in global hit
7672 This option only sets a preference. If the parent is unavailable a
7673 direct connection to the origin server may still be attempted. To
7674 completely prevent direct connections use never_direct.
7679 LOC: Config.onoff.prefer_direct
7682 Normally Squid tries to use parents for most requests. If you for some
7683 reason like it to first try going direct and only use a parent if
7684 going direct fails set this to on.
7686 By combining nonhierarchical_direct off and prefer_direct on you
7687 can set up Squid to use a parent as a backup path if going direct
7690 Note: If you want Squid to use parents for all requests see
7691 the never_direct directive. prefer_direct only modifies how Squid
7692 acts on cacheable requests.
7695 NAME: cache_miss_revalidate
7699 LOC: Config.onoff.cache_miss_revalidate
7701 RFC 7232 defines a conditional request mechanism to prevent
7702 response objects being unnecessarily transferred over the network.
7703 If that mechanism is used by the client and a cache MISS occurs
7704 it can prevent new cache entries being created.
7706 This option determines whether Squid on cache MISS will pass the
7707 client revalidation request to the server or tries to fetch new
7708 content for caching. It can be useful while the cache is mostly
7709 empty to more quickly have the cache populated by generating
7710 non-conditional GETs.
7712 When set to 'on' (default), Squid will pass all client If-* headers
7713 to the server. This permits server responses without a cacheable
7714 payload to be delivered and on MISS no new cache entry is created.
7716 When set to 'off' and if the request is cacheable, Squid will
7717 remove the clients If-Modified-Since and If-None-Match headers from
7718 the request sent to the server. This requests a 200 status response
7719 from the server to create a new cache entry with.
7724 LOC: Config.accessList.AlwaysDirect
7726 DEFAULT_DOC: Prevent any cache_peer being used for this request.
7728 Usage: always_direct allow|deny [!]aclname ...
7730 Here you can use ACL elements to specify requests which should
7731 ALWAYS be forwarded by Squid to the origin servers without using
7732 any peers. For example, to always directly forward requests for
7733 local servers ignoring any parents or siblings you may have use
7736 acl local-servers dstdomain my.domain.net
7737 always_direct allow local-servers
7739 To always forward FTP requests directly, use
7742 always_direct allow FTP
7744 NOTE: There is a similar, but opposite option named
7745 'never_direct'. You need to be aware that "always_direct deny
7746 foo" is NOT the same thing as "never_direct allow foo". You
7747 may need to use a deny rule to exclude a more-specific case of
7748 some other rule. Example:
7750 acl local-external dstdomain external.foo.net
7751 acl local-servers dstdomain .foo.net
7752 always_direct deny local-external
7753 always_direct allow local-servers
7755 NOTE: If your goal is to make the client forward the request
7756 directly to the origin server bypassing Squid then this needs
7757 to be done in the client configuration. Squid configuration
7758 can only tell Squid how Squid should fetch the object.
7760 NOTE: This directive is not related to caching. The replies
7761 is cached as usual even if you use always_direct. To not cache
7762 the replies see the 'cache' directive.
7764 This clause supports both fast and slow acl types.
7765 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
7770 LOC: Config.accessList.NeverDirect
7772 DEFAULT_DOC: Allow DNS results to be used for this request.
7774 Usage: never_direct allow|deny [!]aclname ...
7776 never_direct is the opposite of always_direct. Please read
7777 the description for always_direct if you have not already.
7779 With 'never_direct' you can use ACL elements to specify
7780 requests which should NEVER be forwarded directly to origin
7781 servers. For example, to force the use of a proxy for all
7782 requests, except those in your local domain use something like:
7784 acl local-servers dstdomain .foo.net
7785 never_direct deny local-servers
7786 never_direct allow all
7788 or if Squid is inside a firewall and there are local intranet
7789 servers inside the firewall use something like:
7791 acl local-intranet dstdomain .foo.net
7792 acl local-external dstdomain external.foo.net
7793 always_direct deny local-external
7794 always_direct allow local-intranet
7795 never_direct allow all
7797 This clause supports both fast and slow acl types.
7798 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
7802 ADVANCED NETWORKING OPTIONS
7803 -----------------------------------------------------------------------------
7806 NAME: incoming_udp_average incoming_icp_average
7809 LOC: Config.comm_incoming.udp.average
7811 Heavy voodoo here. I can't even believe you are reading this.
7812 Are you crazy? Don't even think about adjusting these unless
7813 you understand the algorithms in comm_select.c first!
7816 NAME: incoming_tcp_average incoming_http_average
7819 LOC: Config.comm_incoming.tcp.average
7821 Heavy voodoo here. I can't even believe you are reading this.
7822 Are you crazy? Don't even think about adjusting these unless
7823 you understand the algorithms in comm_select.c first!
7826 NAME: incoming_dns_average
7829 LOC: Config.comm_incoming.dns.average
7831 Heavy voodoo here. I can't even believe you are reading this.
7832 Are you crazy? Don't even think about adjusting these unless
7833 you understand the algorithms in comm_select.c first!
7836 NAME: min_udp_poll_cnt min_icp_poll_cnt
7839 LOC: Config.comm_incoming.udp.min_poll
7841 Heavy voodoo here. I can't even believe you are reading this.
7842 Are you crazy? Don't even think about adjusting these unless
7843 you understand the algorithms in comm_select.c first!
7846 NAME: min_dns_poll_cnt
7849 LOC: Config.comm_incoming.dns.min_poll
7851 Heavy voodoo here. I can't even believe you are reading this.
7852 Are you crazy? Don't even think about adjusting these unless
7853 you understand the algorithms in comm_select.c first!
7856 NAME: min_tcp_poll_cnt min_http_poll_cnt
7859 LOC: Config.comm_incoming.tcp.min_poll
7861 Heavy voodoo here. I can't even believe you are reading this.
7862 Are you crazy? Don't even think about adjusting these unless
7863 you understand the algorithms in comm_select.c first!
7869 LOC: Config.accept_filter
7873 The name of an accept(2) filter to install on Squid's
7874 listen socket(s). This feature is perhaps specific to
7875 FreeBSD and requires support in the kernel.
7877 The 'httpready' filter delays delivering new connections
7878 to Squid until a full HTTP request has been received.
7879 See the accf_http(9) man page for details.
7881 The 'dataready' filter delays delivering new connections
7882 to Squid until there is some data to process.
7883 See the accf_dataready(9) man page for details.
7887 The 'data' filter delays delivering of new connections
7888 to Squid until there is some data to process by TCP_ACCEPT_DEFER.
7889 You may optionally specify a number of seconds to wait by
7890 'data=N' where N is the number of seconds. Defaults to 30
7891 if not specified. See the tcp(7) man page for details.
7894 accept_filter httpready
7899 NAME: client_ip_max_connections
7901 LOC: Config.client_ip_max_connections
7903 DEFAULT_DOC: No limit.
7905 Set an absolute limit on the number of connections a single
7906 client IP can use. Any more than this and Squid will begin to drop
7907 new connections from the client until it closes some links.
7909 Note that this is a global limit. It affects all HTTP, HTCP, Gopher and FTP
7910 connections from the client. For finer control use the ACL access controls.
7912 Requires client_db to be enabled (the default).
7914 WARNING: This may noticably slow down traffic received via external proxies
7915 or NAT devices and cause them to rebound error messages back to their clients.
7918 NAME: tcp_recv_bufsize
7922 DEFAULT_DOC: Use operating system TCP defaults.
7923 LOC: Config.tcpRcvBufsz
7925 Size of receive buffer to set for TCP sockets. Probably just
7926 as easy to change your kernel's default.
7927 Omit from squid.conf to use the default buffer size.
7932 -----------------------------------------------------------------------------
7939 LOC: Adaptation::Icap::TheConfig.onoff
7942 If you want to enable the ICAP module support, set this to on.
7945 NAME: icap_connect_timeout
7948 LOC: Adaptation::Icap::TheConfig.connect_timeout_raw
7951 This parameter specifies how long to wait for the TCP connect to
7952 the requested ICAP server to complete before giving up and either
7953 terminating the HTTP transaction or bypassing the failure.
7955 The default for optional services is peer_connect_timeout.
7956 The default for essential services is connect_timeout.
7957 If this option is explicitly set, its value applies to all services.
7960 NAME: icap_io_timeout
7964 DEFAULT_DOC: Use read_timeout.
7965 LOC: Adaptation::Icap::TheConfig.io_timeout_raw
7968 This parameter specifies how long to wait for an I/O activity on
7969 an established, active ICAP connection before giving up and
7970 either terminating the HTTP transaction or bypassing the
7974 NAME: icap_service_failure_limit
7975 COMMENT: limit [in memory-depth time-units]
7976 TYPE: icap_service_failure_limit
7978 LOC: Adaptation::Icap::TheConfig
7981 The limit specifies the number of failures that Squid tolerates
7982 when establishing a new TCP connection with an ICAP service. If
7983 the number of failures exceeds the limit, the ICAP service is
7984 not used for new ICAP requests until it is time to refresh its
7987 A negative value disables the limit. Without the limit, an ICAP
7988 service will not be considered down due to connectivity failures
7989 between ICAP OPTIONS requests.
7991 Squid forgets ICAP service failures older than the specified
7992 value of memory-depth. The memory fading algorithm
7993 is approximate because Squid does not remember individual
7994 errors but groups them instead, splitting the option
7995 value into ten time slots of equal length.
7997 When memory-depth is 0 and by default this option has no
7998 effect on service failure expiration.
8000 Squid always forgets failures when updating service settings
8001 using an ICAP OPTIONS transaction, regardless of this option
8005 # suspend service usage after 10 failures in 5 seconds:
8006 icap_service_failure_limit 10 in 5 seconds
8009 NAME: icap_service_revival_delay
8012 LOC: Adaptation::Icap::TheConfig.service_revival_delay
8015 The delay specifies the number of seconds to wait after an ICAP
8016 OPTIONS request failure before requesting the options again. The
8017 failed ICAP service is considered "down" until fresh OPTIONS are
8020 The actual delay cannot be smaller than the hardcoded minimum
8021 delay of 30 seconds.
8024 NAME: icap_preview_enable
8028 LOC: Adaptation::Icap::TheConfig.preview_enable
8031 The ICAP Preview feature allows the ICAP server to handle the
8032 HTTP message by looking only at the beginning of the message body
8033 or even without receiving the body at all. In some environments,
8034 previews greatly speedup ICAP processing.
8036 During an ICAP OPTIONS transaction, the server may tell Squid what
8037 HTTP messages should be previewed and how big the preview should be.
8038 Squid will not use Preview if the server did not request one.
8040 To disable ICAP Preview for all ICAP services, regardless of
8041 individual ICAP server OPTIONS responses, set this option to "off".
8043 icap_preview_enable off
8046 NAME: icap_preview_size
8049 LOC: Adaptation::Icap::TheConfig.preview_size
8051 DEFAULT_DOC: No preview sent.
8053 The default size of preview data to be sent to the ICAP server.
8054 This value might be overwritten on a per server basis by OPTIONS requests.
8057 NAME: icap_206_enable
8061 LOC: Adaptation::Icap::TheConfig.allow206_enable
8064 206 (Partial Content) responses is an ICAP extension that allows the
8065 ICAP agents to optionally combine adapted and original HTTP message
8066 content. The decision to combine is postponed until the end of the
8067 ICAP response. Squid supports Partial Content extension by default.
8069 Activation of the Partial Content extension is negotiated with each
8070 ICAP service during OPTIONS exchange. Most ICAP servers should handle
8071 negotation correctly even if they do not support the extension, but
8072 some might fail. To disable Partial Content support for all ICAP
8073 services and to avoid any negotiation, set this option to "off".
8079 NAME: icap_default_options_ttl
8082 LOC: Adaptation::Icap::TheConfig.default_options_ttl
8085 The default TTL value for ICAP OPTIONS responses that don't have
8086 an Options-TTL header.
8089 NAME: icap_persistent_connections
8093 LOC: Adaptation::Icap::TheConfig.reuse_connections
8096 Whether or not Squid should use persistent connections to
8100 NAME: adaptation_send_client_ip icap_send_client_ip
8102 IFDEF: USE_ADAPTATION
8104 LOC: Adaptation::Config::send_client_ip
8107 If enabled, Squid shares HTTP client IP information with adaptation
8108 services. For ICAP, Squid adds the X-Client-IP header to ICAP requests.
8109 For eCAP, Squid sets the libecap::metaClientIp transaction option.
8111 See also: adaptation_uses_indirect_client
8114 NAME: adaptation_send_username icap_send_client_username
8116 IFDEF: USE_ADAPTATION
8118 LOC: Adaptation::Config::send_username
8121 This sends authenticated HTTP client username (if available) to
8122 the adaptation service.
8124 For ICAP, the username value is encoded based on the
8125 icap_client_username_encode option and is sent using the header
8126 specified by the icap_client_username_header option.
8129 NAME: icap_client_username_header
8132 LOC: Adaptation::Icap::TheConfig.client_username_header
8133 DEFAULT: X-Client-Username
8135 ICAP request header name to use for adaptation_send_username.
8138 NAME: icap_client_username_encode
8142 LOC: Adaptation::Icap::TheConfig.client_username_encode
8145 Whether to base64 encode the authenticated client username.
8149 TYPE: icap_service_type
8151 LOC: Adaptation::Icap::TheConfig
8154 Defines a single ICAP service using the following format:
8156 icap_service id vectoring_point uri [option ...]
8159 an opaque identifier or name which is used to direct traffic to
8160 this specific service. Must be unique among all adaptation
8161 services in squid.conf.
8163 vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
8164 This specifies at which point of transaction processing the
8165 ICAP service should be activated. *_postcache vectoring points
8166 are not yet supported.
8168 uri: icap://servername:port/servicepath
8169 ICAP server and service location.
8171 ICAP does not allow a single service to handle both REQMOD and RESPMOD
8172 transactions. Squid does not enforce that requirement. You can specify
8173 services with the same service_url and different vectoring_points. You
8174 can even specify multiple identical services as long as their
8175 service_names differ.
8177 To activate a service, use the adaptation_access directive. To group
8178 services, use adaptation_service_chain and adaptation_service_set.
8180 Service options are separated by white space. ICAP services support
8181 the following name=value options:
8184 If set to 'on' or '1', the ICAP service is treated as
8185 optional. If the service cannot be reached or malfunctions,
8186 Squid will try to ignore any errors and process the message as
8187 if the service was not enabled. No all ICAP errors can be
8188 bypassed. If set to 0, the ICAP service is treated as
8189 essential and all ICAP errors will result in an error page
8190 returned to the HTTP client.
8192 Bypass is off by default: services are treated as essential.
8195 If set to 'on' or '1', the ICAP service is allowed to
8196 dynamically change the current message adaptation plan by
8197 returning a chain of services to be used next. The services
8198 are specified using the X-Next-Services ICAP response header
8199 value, formatted as a comma-separated list of service names.
8200 Each named service should be configured in squid.conf. Other
8201 services are ignored. An empty X-Next-Services value results
8202 in an empty plan which ends the current adaptation.
8204 Dynamic adaptation plan may cross or cover multiple supported
8205 vectoring points in their natural processing order.
8207 Routing is not allowed by default: the ICAP X-Next-Services
8208 response header is ignored.
8211 Only has effect on split-stack systems. The default on those systems
8212 is to use IPv4-only connections. When set to 'on' this option will
8213 make Squid use IPv6-only connections to contact this ICAP service.
8215 on-overload=block|bypass|wait|force
8216 If the service Max-Connections limit has been reached, do
8217 one of the following for each new ICAP transaction:
8218 * block: send an HTTP error response to the client
8219 * bypass: ignore the "over-connected" ICAP service
8220 * wait: wait (in a FIFO queue) for an ICAP connection slot
8221 * force: proceed, ignoring the Max-Connections limit
8223 In SMP mode with N workers, each worker assumes the service
8224 connection limit is Max-Connections/N, even though not all
8225 workers may use a given service.
8227 The default value is "bypass" if service is bypassable,
8228 otherwise it is set to "wait".
8232 Use the given number as the Max-Connections limit, regardless
8233 of the Max-Connections value given by the service, if any.
8235 Older icap_service format without optional named parameters is
8236 deprecated but supported for backward compatibility.
8239 icap_service svcBlocker reqmod_precache icap://icap1.mydomain.net:1344/reqmod bypass=0
8240 icap_service svcLogger reqmod_precache icap://icap2.mydomain.net:1344/respmod routing=on
8244 TYPE: icap_class_type
8249 This deprecated option was documented to define an ICAP service
8250 chain, even though it actually defined a set of similar, redundant
8251 services, and the chains were not supported.
8253 To define a set of redundant services, please use the
8254 adaptation_service_set directive. For service chains, use
8255 adaptation_service_chain.
8259 TYPE: icap_access_type
8264 This option is deprecated. Please use adaptation_access, which
8265 has the same ICAP functionality, but comes with better
8266 documentation, and eCAP support.
8271 -----------------------------------------------------------------------------
8278 LOC: Adaptation::Ecap::TheConfig.onoff
8281 Controls whether eCAP support is enabled.
8285 TYPE: ecap_service_type
8287 LOC: Adaptation::Ecap::TheConfig
8290 Defines a single eCAP service
8292 ecap_service id vectoring_point uri [option ...]
8295 an opaque identifier or name which is used to direct traffic to
8296 this specific service. Must be unique among all adaptation
8297 services in squid.conf.
8299 vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
8300 This specifies at which point of transaction processing the
8301 eCAP service should be activated. *_postcache vectoring points
8302 are not yet supported.
8304 uri: ecap://vendor/service_name?custom&cgi=style¶meters=optional
8305 Squid uses the eCAP service URI to match this configuration
8306 line with one of the dynamically loaded services. Each loaded
8307 eCAP service must have a unique URI. Obtain the right URI from
8308 the service provider.
8310 To activate a service, use the adaptation_access directive. To group
8311 services, use adaptation_service_chain and adaptation_service_set.
8313 Service options are separated by white space. eCAP services support
8314 the following name=value options:
8317 If set to 'on' or '1', the eCAP service is treated as optional.
8318 If the service cannot be reached or malfunctions, Squid will try
8319 to ignore any errors and process the message as if the service
8320 was not enabled. No all eCAP errors can be bypassed.
8321 If set to 'off' or '0', the eCAP service is treated as essential
8322 and all eCAP errors will result in an error page returned to the
8325 Bypass is off by default: services are treated as essential.
8328 If set to 'on' or '1', the eCAP service is allowed to
8329 dynamically change the current message adaptation plan by
8330 returning a chain of services to be used next.
8332 Dynamic adaptation plan may cross or cover multiple supported
8333 vectoring points in their natural processing order.
8335 Routing is not allowed by default.
8337 Older ecap_service format without optional named parameters is
8338 deprecated but supported for backward compatibility.
8342 ecap_service s1 reqmod_precache ecap://filters.R.us/leakDetector?on_error=block bypass=off
8343 ecap_service s2 respmod_precache ecap://filters.R.us/virusFilter config=/etc/vf.cfg bypass=on
8346 NAME: loadable_modules
8348 IFDEF: USE_LOADABLE_MODULES
8349 LOC: Config.loadable_module_names
8352 Instructs Squid to load the specified dynamic module(s) or activate
8353 preloaded module(s).
8355 loadable_modules @DEFAULT_PREFIX@/lib/MinimalAdapter.so
8359 MESSAGE ADAPTATION OPTIONS
8360 -----------------------------------------------------------------------------
8363 NAME: adaptation_service_set
8364 TYPE: adaptation_service_set_type
8365 IFDEF: USE_ADAPTATION
8370 Configures an ordered set of similar, redundant services. This is
8371 useful when hot standby or backup adaptation servers are available.
8373 adaptation_service_set set_name service_name1 service_name2 ...
8375 The named services are used in the set declaration order. The first
8376 applicable adaptation service from the set is used first. The next
8377 applicable service is tried if and only if the transaction with the
8378 previous service fails and the message waiting to be adapted is still
8381 When adaptation starts, broken services are ignored as if they were
8382 not a part of the set. A broken service is a down optional service.
8384 The services in a set must be attached to the same vectoring point
8385 (e.g., pre-cache) and use the same adaptation method (e.g., REQMOD).
8387 If all services in a set are optional then adaptation failures are
8388 bypassable. If all services in the set are essential, then a
8389 transaction failure with one service may still be retried using
8390 another service from the set, but when all services fail, the master
8391 transaction fails as well.
8393 A set may contain a mix of optional and essential services, but that
8394 is likely to lead to surprising results because broken services become
8395 ignored (see above), making previously bypassable failures fatal.
8396 Technically, it is the bypassability of the last failed service that
8399 See also: adaptation_access adaptation_service_chain
8402 adaptation_service_set svcBlocker urlFilterPrimary urlFilterBackup
8403 adaptation service_set svcLogger loggerLocal loggerRemote
8406 NAME: adaptation_service_chain
8407 TYPE: adaptation_service_chain_type
8408 IFDEF: USE_ADAPTATION
8413 Configures a list of complementary services that will be applied
8414 one-by-one, forming an adaptation chain or pipeline. This is useful
8415 when Squid must perform different adaptations on the same message.
8417 adaptation_service_chain chain_name service_name1 svc_name2 ...
8419 The named services are used in the chain declaration order. The first
8420 applicable adaptation service from the chain is used first. The next
8421 applicable service is applied to the successful adaptation results of
8422 the previous service in the chain.
8424 When adaptation starts, broken services are ignored as if they were
8425 not a part of the chain. A broken service is a down optional service.
8427 Request satisfaction terminates the adaptation chain because Squid
8428 does not currently allow declaration of RESPMOD services at the
8429 "reqmod_precache" vectoring point (see icap_service or ecap_service).
8431 The services in a chain must be attached to the same vectoring point
8432 (e.g., pre-cache) and use the same adaptation method (e.g., REQMOD).
8434 A chain may contain a mix of optional and essential services. If an
8435 essential adaptation fails (or the failure cannot be bypassed for
8436 other reasons), the master transaction fails. Otherwise, the failure
8437 is bypassed as if the failed adaptation service was not in the chain.
8439 See also: adaptation_access adaptation_service_set
8442 adaptation_service_chain svcRequest requestLogger urlFilter leakDetector
8445 NAME: adaptation_access
8446 TYPE: adaptation_access_type
8447 IFDEF: USE_ADAPTATION
8450 DEFAULT_DOC: Allow, unless rules exist in squid.conf.
8452 Sends an HTTP transaction to an ICAP or eCAP adaptation service.
8454 adaptation_access service_name allow|deny [!]aclname...
8455 adaptation_access set_name allow|deny [!]aclname...
8457 At each supported vectoring point, the adaptation_access
8458 statements are processed in the order they appear in this
8459 configuration file. Statements pointing to the following services
8460 are ignored (i.e., skipped without checking their ACL):
8462 - services serving different vectoring points
8463 - "broken-but-bypassable" services
8464 - "up" services configured to ignore such transactions
8465 (e.g., based on the ICAP Transfer-Ignore header).
8467 When a set_name is used, all services in the set are checked
8468 using the same rules, to find the first applicable one. See
8469 adaptation_service_set for details.
8471 If an access list is checked and there is a match, the
8472 processing stops: For an "allow" rule, the corresponding
8473 adaptation service is used for the transaction. For a "deny"
8474 rule, no adaptation service is activated.
8476 It is currently not possible to apply more than one adaptation
8477 service at the same vectoring point to the same HTTP transaction.
8479 See also: icap_service and ecap_service
8482 adaptation_access service_1 allow all
8485 NAME: adaptation_service_iteration_limit
8487 IFDEF: USE_ADAPTATION
8488 LOC: Adaptation::Config::service_iteration_limit
8491 Limits the number of iterations allowed when applying adaptation
8492 services to a message. If your longest adaptation set or chain
8493 may have more than 16 services, increase the limit beyond its
8494 default value of 16. If detecting infinite iteration loops sooner
8495 is critical, make the iteration limit match the actual number
8496 of services in your longest adaptation set or chain.
8498 Infinite adaptation loops are most likely with routing services.
8500 See also: icap_service routing=1
8503 NAME: adaptation_masterx_shared_names
8505 IFDEF: USE_ADAPTATION
8506 LOC: Adaptation::Config::masterx_shared_name
8509 For each master transaction (i.e., the HTTP request and response
8510 sequence, including all related ICAP and eCAP exchanges), Squid
8511 maintains a table of metadata. The table entries are (name, value)
8512 pairs shared among eCAP and ICAP exchanges. The table is destroyed
8513 with the master transaction.
8515 This option specifies the table entry names that Squid must accept
8516 from and forward to the adaptation transactions.
8518 An ICAP REQMOD or RESPMOD transaction may set an entry in the
8519 shared table by returning an ICAP header field with a name
8520 specified in adaptation_masterx_shared_names.
8522 An eCAP REQMOD or RESPMOD transaction may set an entry in the
8523 shared table by implementing the libecap::visitEachOption() API
8524 to provide an option with a name specified in
8525 adaptation_masterx_shared_names.
8527 Squid will store and forward the set entry to subsequent adaptation
8528 transactions within the same master transaction scope.
8530 Only one shared entry name is supported at this time.
8533 # share authentication information among ICAP services
8534 adaptation_masterx_shared_names X-Subscriber-ID
8537 NAME: adaptation_meta
8539 IFDEF: USE_ADAPTATION
8540 LOC: Adaptation::Config::metaHeaders
8543 This option allows Squid administrator to add custom ICAP request
8544 headers or eCAP options to Squid ICAP requests or eCAP transactions.
8545 Use it to pass custom authentication tokens and other
8546 transaction-state related meta information to an ICAP/eCAP service.
8548 The addition of a meta header is ACL-driven:
8549 adaptation_meta name value [!]aclname ...
8551 Processing for a given header name stops after the first ACL list match.
8552 Thus, it is impossible to add two headers with the same name. If no ACL
8553 lists match for a given header name, no such header is added. For
8556 # do not debug transactions except for those that need debugging
8557 adaptation_meta X-Debug 1 needs_debugging
8559 # log all transactions except for those that must remain secret
8560 adaptation_meta X-Log 1 !keep_secret
8562 # mark transactions from users in the "G 1" group
8563 adaptation_meta X-Authenticated-Groups "G 1" authed_as_G1
8565 The "value" parameter may be a regular squid.conf token or a "double
8566 quoted string". Within the quoted string, use backslash (\) to escape
8567 any character, which is currently only useful for escaping backslashes
8568 and double quotes. For example,
8569 "this string has one backslash (\\) and two \"quotes\""
8571 Used adaptation_meta header values may be logged via %note
8572 logformat code. If multiple adaptation_meta headers with the same name
8573 are used during master transaction lifetime, the header values are
8574 logged in the order they were used and duplicate values are ignored
8575 (only the first repeated value will be logged).
8581 LOC: Adaptation::Icap::TheConfig.repeat
8582 DEFAULT_IF_NONE: deny all
8584 This ACL determines which retriable ICAP transactions are
8585 retried. Transactions that received a complete ICAP response
8586 and did not have to consume or produce HTTP bodies to receive
8587 that response are usually retriable.
8589 icap_retry allow|deny [!]aclname ...
8591 Squid automatically retries some ICAP I/O timeouts and errors
8592 due to persistent connection race conditions.
8594 See also: icap_retry_limit
8597 NAME: icap_retry_limit
8600 LOC: Adaptation::Icap::TheConfig.repeat_limit
8602 DEFAULT_DOC: No retries are allowed.
8604 Limits the number of retries allowed.
8606 Communication errors due to persistent connection race
8607 conditions are unavoidable, automatically retried, and do not
8608 count against this limit.
8610 See also: icap_retry
8616 -----------------------------------------------------------------------------
8619 NAME: check_hostnames
8622 LOC: Config.onoff.check_hostnames
8624 For security and stability reasons Squid can check
8625 hostnames for Internet standard RFC compliance. If you want
8626 Squid to perform these checks turn this directive on.
8629 NAME: allow_underscore
8632 LOC: Config.onoff.allow_underscore
8634 Underscore characters is not strictly allowed in Internet hostnames
8635 but nevertheless used by many sites. Set this to off if you want
8636 Squid to be strict about the standard.
8637 This check is performed only when check_hostnames is set to on.
8640 NAME: dns_retransmit_interval
8643 LOC: Config.Timeout.idns_retransmit
8645 Initial retransmit interval for DNS queries. The interval is
8646 doubled each time all configured DNS servers have been tried.
8652 LOC: Config.Timeout.idns_query
8654 DNS Query timeout. If no response is received to a DNS query
8655 within this time all DNS servers for the queried domain
8656 are assumed to be unavailable.
8659 NAME: dns_packet_max
8661 DEFAULT_DOC: EDNS disabled
8663 LOC: Config.dns.packet_max
8665 Maximum number of bytes packet size to advertise via EDNS.
8666 Set to "none" to disable EDNS large packet support.
8668 For legacy reasons DNS UDP replies will default to 512 bytes which
8669 is too small for many responses. EDNS provides a means for Squid to
8670 negotiate receiving larger responses back immediately without having
8671 to failover with repeat requests. Responses larger than this limit
8672 will retain the old behaviour of failover to TCP DNS.
8674 Squid has no real fixed limit internally, but allowing packet sizes
8675 over 1500 bytes requires network jumbogram support and is usually not
8678 WARNING: The RFC also indicates that some older resolvers will reply
8679 with failure of the whole request if the extension is added. Some
8680 resolvers have already been identified which will reply with mangled
8681 EDNS response on occasion. Usually in response to many-KB jumbogram
8682 sizes being advertised by Squid.
8683 Squid will currently treat these both as an unable-to-resolve domain
8684 even if it would be resolvable without EDNS.
8691 DEFAULT_DOC: Search for single-label domain names is disabled.
8692 LOC: Config.onoff.res_defnames
8694 Normally the RES_DEFNAMES resolver option is disabled
8695 (see res_init(3)). This prevents caches in a hierarchy
8696 from interpreting single-component hostnames locally. To allow
8697 Squid to handle single-component names, enable this option.
8700 NAME: dns_multicast_local
8704 DEFAULT_DOC: Search for .local and .arpa names is disabled.
8705 LOC: Config.onoff.dns_mdns
8707 When set to on, Squid sends multicast DNS lookups on the local
8708 network for domains ending in .local and .arpa.
8709 This enables local servers and devices to be contacted in an
8710 ad-hoc or zero-configuration network environment.
8713 NAME: dns_nameservers
8716 DEFAULT_DOC: Use operating system definitions
8717 LOC: Config.dns_nameservers
8719 Use this if you want to specify a list of DNS name servers
8720 (IP addresses) to use instead of those given in your
8721 /etc/resolv.conf file.
8723 On Windows platforms, if no value is specified here or in
8724 the /etc/resolv.conf file, the list of DNS name servers are
8725 taken from the Windows registry, both static and dynamic DHCP
8726 configurations are supported.
8728 Example: dns_nameservers 10.0.0.1 192.172.0.4
8733 DEFAULT: @DEFAULT_HOSTS@
8734 LOC: Config.etcHostsPath
8736 Location of the host-local IP name-address associations
8737 database. Most Operating Systems have such a file on different
8739 - Un*X & Linux: /etc/hosts
8740 - Windows NT/2000: %SystemRoot%\system32\drivers\etc\hosts
8741 (%SystemRoot% value install default is c:\winnt)
8742 - Windows XP/2003: %SystemRoot%\system32\drivers\etc\hosts
8743 (%SystemRoot% value install default is c:\windows)
8744 - Windows 9x/Me: %windir%\hosts
8745 (%windir% value is usually c:\windows)
8746 - Cygwin: /etc/hosts
8748 The file contains newline-separated definitions, in the
8749 form ip_address_in_dotted_form name [name ...] names are
8750 whitespace-separated. Lines beginning with an hash (#)
8751 character are comments.
8753 The file is checked at startup and upon configuration.
8754 If set to 'none', it won't be checked.
8755 If append_domain is used, that domain will be added to
8756 domain-local (i.e. not containing any dot character) host
8762 LOC: Config.appendDomain
8764 DEFAULT_DOC: Use operating system definitions
8766 Appends local domain name to hostnames without any dots in
8767 them. append_domain must begin with a period.
8769 Be warned there are now Internet names with no dots in
8770 them using only top-domain names, so setting this may
8771 cause some Internet sites to become unavailable.
8774 append_domain .yourdomain.com
8777 NAME: ignore_unknown_nameservers
8779 LOC: Config.onoff.ignore_unknown_nameservers
8782 By default Squid checks that DNS responses are received
8783 from the same IP addresses they are sent to. If they
8784 don't match, Squid ignores the response and writes a warning
8785 message to cache.log. You can allow responses from unknown
8786 nameservers by setting this option to 'off'.
8792 LOC: Config.dns.v4_first
8794 With the IPv6 Internet being as fast or faster than IPv4 Internet
8795 for most networks Squid prefers to contact websites over IPv6.
8797 This option reverses the order of preference to make Squid contact
8798 dual-stack websites over IPv4 first. Squid will still perform both
8799 IPv6 and IPv4 DNS lookups before connecting.
8802 This option will restrict the situations under which IPv6
8803 connectivity is used (and tested). Hiding network problems
8804 which would otherwise be detected and warned about.
8808 COMMENT: (number of entries)
8811 LOC: Config.ipcache.size
8813 Maximum number of DNS IP cache entries.
8820 LOC: Config.ipcache.low
8827 LOC: Config.ipcache.high
8829 The size, low-, and high-water marks for the IP cache.
8832 NAME: fqdncache_size
8833 COMMENT: (number of entries)
8836 LOC: Config.fqdncache.size
8838 Maximum number of FQDN cache entries.
8843 -----------------------------------------------------------------------------
8846 NAME: configuration_includes_quoted_values
8848 TYPE: configuration_includes_quoted_values
8850 LOC: ConfigParser::RecognizeQuotedValues
8852 If set, Squid will recognize each "quoted string" after a configuration
8853 directive as a single parameter. The quotes are stripped before the
8854 parameter value is interpreted or used.
8855 See "Values with spaces, quotes, and other special characters"
8856 section for more details.
8863 LOC: Config.onoff.mem_pools
8865 If set, Squid will keep pools of allocated (but unused) memory
8866 available for future use. If memory is a premium on your
8867 system and you believe your malloc library outperforms Squid
8868 routines, disable this.
8871 NAME: memory_pools_limit
8875 LOC: Config.MemPools.limit
8877 Used only with memory_pools on:
8878 memory_pools_limit 50 MB
8880 If set to a non-zero value, Squid will keep at most the specified
8881 limit of allocated (but unused) memory in memory pools. All free()
8882 requests that exceed this limit will be handled by your malloc
8883 library. Squid does not pre-allocate any memory, just safe-keeps
8884 objects that otherwise would be free()d. Thus, it is safe to set
8885 memory_pools_limit to a reasonably high value even if your
8886 configuration will use less memory.
8888 If set to none, Squid will keep all memory it can. That is, there
8889 will be no limit on the total amount of memory used for safe-keeping.
8891 To disable memory allocation optimization, do not set
8892 memory_pools_limit to 0 or none. Set memory_pools to "off" instead.
8894 An overhead for maintaining memory pools is not taken into account
8895 when the limit is checked. This overhead is close to four bytes per
8896 object kept. However, pools may actually _save_ memory because of
8897 reduced memory thrashing in your malloc library.
8901 COMMENT: on|off|transparent|truncate|delete
8904 LOC: opt_forwarded_for
8906 If set to "on", Squid will append your client's IP address
8907 in the HTTP requests it forwards. By default it looks like:
8909 X-Forwarded-For: 192.1.2.3
8911 If set to "off", it will appear as
8913 X-Forwarded-For: unknown
8915 If set to "transparent", Squid will not alter the
8916 X-Forwarded-For header in any way.
8918 If set to "delete", Squid will delete the entire
8919 X-Forwarded-For header.
8921 If set to "truncate", Squid will remove all existing
8922 X-Forwarded-For entries, and place the client IP as the sole entry.
8925 NAME: cachemgr_passwd
8926 TYPE: cachemgrpasswd
8928 DEFAULT_DOC: No password. Actions which require password are denied.
8929 LOC: Config.passwd_list
8931 Specify passwords for cachemgr operations.
8933 Usage: cachemgr_passwd password action action ...
8935 Some valid actions are (see cache manager menu for a full list):
8975 * Indicates actions which will not be performed without a
8976 valid password, others can be performed if not listed here.
8978 To disable an action, set the password to "disable".
8979 To allow performing an action without a password, set the
8982 Use the keyword "all" to set the same password for all actions.
8985 cachemgr_passwd secret shutdown
8986 cachemgr_passwd lesssssssecret info stats/objects
8987 cachemgr_passwd disable all
8994 LOC: Config.onoff.client_db
8996 If you want to disable collecting per-client statistics,
8997 turn off client_db here.
9000 NAME: refresh_all_ims
9004 LOC: Config.onoff.refresh_all_ims
9006 When you enable this option, squid will always check
9007 the origin server for an update when a client sends an
9008 If-Modified-Since request. Many browsers use IMS
9009 requests when the user requests a reload, and this
9010 ensures those clients receive the latest version.
9012 By default (off), squid may return a Not Modified response
9013 based on the age of the cached version.
9016 NAME: reload_into_ims
9017 IFDEF: USE_HTTP_VIOLATIONS
9021 LOC: Config.onoff.reload_into_ims
9023 When you enable this option, client no-cache or ``reload''
9024 requests will be changed to If-Modified-Since requests.
9025 Doing this VIOLATES the HTTP standard. Enabling this
9026 feature could make you liable for problems which it
9029 see also refresh_pattern for a more selective approach.
9032 NAME: connect_retries
9034 LOC: Config.connect_retries
9036 DEFAULT_DOC: Do not retry failed connections.
9038 This sets the maximum number of connection attempts made for each
9039 TCP connection. The connect_retries attempts must all still
9040 complete within the connection timeout period.
9042 The default is not to re-try if the first connection attempt fails.
9043 The (not recommended) maximum is 10 tries.
9045 A warning message will be generated if it is set to a too-high
9046 value and the configured value will be over-ridden.
9048 Note: These re-tries are in addition to forward_max_tries
9049 which limit how many different addresses may be tried to find
9053 NAME: retry_on_error
9055 LOC: Config.retry.onerror
9058 If set to ON Squid will automatically retry requests when
9059 receiving an error response with status 403 (Forbidden),
9060 500 (Internal Error), 501 or 503 (Service not available).
9061 Status 502 and 504 (Gateway errors) are always retried.
9063 This is mainly useful if you are in a complex cache hierarchy to
9064 work around access control errors.
9066 NOTE: This retry will attempt to find another working destination.
9067 Which is different from the server which just failed.
9070 NAME: as_whois_server
9072 LOC: Config.as_whois_server
9073 DEFAULT: whois.ra.net
9075 WHOIS server to query for AS numbers. NOTE: AS numbers are
9076 queried only when Squid starts up, not for every request.
9081 LOC: Config.onoff.offline
9084 Enable this option and Squid will never try to validate cached
9088 NAME: uri_whitespace
9089 TYPE: uri_whitespace
9090 LOC: Config.uri_whitespace
9093 What to do with requests that have whitespace characters in the
9096 strip: The whitespace characters are stripped out of the URL.
9097 This is the behavior recommended by RFC2396 and RFC3986
9098 for tolerant handling of generic URI.
9099 NOTE: This is one difference between generic URI and HTTP URLs.
9101 deny: The request is denied. The user receives an "Invalid
9103 This is the behaviour recommended by RFC2616 for safe
9104 handling of HTTP request URL.
9106 allow: The request is allowed and the URI is not changed. The
9107 whitespace characters remain in the URI. Note the
9108 whitespace is passed to redirector processes if they
9110 Note this may be considered a violation of RFC2616
9111 request parsing where whitespace is prohibited in the
9114 encode: The request is allowed and the whitespace characters are
9115 encoded according to RFC1738.
9117 chop: The request is allowed and the URI is chopped at the
9121 NOTE the current Squid implementation of encode and chop violates
9122 RFC2616 by not using a 301 redirect after altering the URL.
9127 LOC: Config.chroot_dir
9130 Specifies a directory where Squid should do a chroot() while
9131 initializing. This also causes Squid to fully drop root
9132 privileges after initializing. This means, for example, if you
9133 use a HTTP port less than 1024 and try to reconfigure, you may
9134 get an error saying that Squid can not open the port.
9137 NAME: balance_on_multiple_ip
9139 LOC: Config.onoff.balance_on_multiple_ip
9142 Modern IP resolvers in squid sort lookup results by preferred access.
9143 By default squid will use these IP in order and only rotates to
9144 the next listed when the most preffered fails.
9146 Some load balancing servers based on round robin DNS have been
9147 found not to preserve user session state across requests
9148 to different IP addresses.
9150 Enabling this directive Squid rotates IP's per request.
9153 NAME: pipeline_prefetch
9154 TYPE: pipelinePrefetch
9155 LOC: Config.pipeline_max_prefetch
9157 DEFAULT_DOC: Do not pre-parse pipelined requests.
9159 HTTP clients may send a pipeline of 1+N requests to Squid using a
9160 single connection, without waiting for Squid to respond to the first
9161 of those requests. This option limits the number of concurrent
9162 requests Squid will try to handle in parallel. If set to N, Squid
9163 will try to receive and process up to 1+N requests on the same
9164 connection concurrently.
9166 Defaults to 0 (off) for bandwidth management and access logging
9169 NOTE: pipelining requires persistent connections to clients.
9171 WARNING: pipelining breaks NTLM and Negotiate/Kerberos authentication.
9174 NAME: high_response_time_warning
9177 LOC: Config.warnings.high_rptm
9179 DEFAULT_DOC: disabled.
9181 If the one-minute median response time exceeds this value,
9182 Squid prints a WARNING with debug level 0 to get the
9183 administrators attention. The value is in milliseconds.
9186 NAME: high_page_fault_warning
9188 LOC: Config.warnings.high_pf
9190 DEFAULT_DOC: disabled.
9192 If the one-minute average page fault rate exceeds this
9193 value, Squid prints a WARNING with debug level 0 to get
9194 the administrators attention. The value is in page faults
9198 NAME: high_memory_warning
9200 LOC: Config.warnings.high_memory
9201 IFDEF: HAVE_MSTATS&&HAVE_GNUMALLOC_H
9203 DEFAULT_DOC: disabled.
9205 If the memory usage (as determined by gnumalloc, if available and used)
9206 exceeds this amount, Squid prints a WARNING with debug level 0 to get
9207 the administrators attention.
9209 # TODO: link high_memory_warning to mempools?
9211 NAME: sleep_after_fork
9212 COMMENT: (microseconds)
9214 LOC: Config.sleep_after_fork
9217 When this is set to a non-zero value, the main Squid process
9218 sleeps the specified number of microseconds after a fork()
9219 system call. This sleep may help the situation where your
9220 system reports fork() failures due to lack of (virtual)
9221 memory. Note, however, if you have a lot of child
9222 processes, these sleep delays will add up and your
9223 Squid will not service requests for some amount of time
9224 until all the child processes have been started.
9225 On Windows value less then 1000 (1 milliseconds) are
9229 NAME: windows_ipaddrchangemonitor
9230 IFDEF: _SQUID_WINDOWS_
9234 LOC: Config.onoff.WIN32_IpAddrChangeMonitor
9236 On Windows Squid by default will monitor IP address changes and will
9237 reconfigure itself after any detected event. This is very useful for
9238 proxies connected to internet with dial-up interfaces.
9239 In some cases (a Proxy server acting as VPN gateway is one) it could be
9240 desiderable to disable this behaviour setting this to 'off'.
9241 Note: after changing this, Squid service must be restarted.
9246 IFDEF: USE_SQUID_EUI
9248 LOC: Eui::TheConfig.euiLookup
9250 Whether to lookup the EUI or MAC address of a connected client.
9253 NAME: max_filedescriptors max_filedesc
9256 DEFAULT_DOC: Use operating system limits set by ulimit.
9257 LOC: Config.max_filedescriptors
9259 Reduce the maximum number of filedescriptors supported below
9260 the usual operating system defaults.
9262 Remove from squid.conf to inherit the current ulimit setting.
9264 Note: Changing this requires a restart of Squid. Also
9265 not all I/O types supports large values (eg on Windows).
9272 DEFAULT_DOC: SMP support disabled.
9274 Number of main Squid processes or "workers" to fork and maintain.
9275 0: "no daemon" mode, like running "squid -N ..."
9276 1: "no SMP" mode, start one main Squid process daemon (default)
9277 N: start N main Squid process daemons (i.e., SMP mode)
9279 In SMP mode, each worker does nearly all what a single Squid daemon
9280 does (e.g., listen on http_port and forward HTTP requests).
9283 NAME: cpu_affinity_map
9284 TYPE: CpuAffinityMap
9285 LOC: Config.cpuAffinityMap
9287 DEFAULT_DOC: Let operating system decide.
9289 Usage: cpu_affinity_map process_numbers=P1,P2,... cores=C1,C2,...
9291 Sets 1:1 mapping between Squid processes and CPU cores. For example,
9293 cpu_affinity_map process_numbers=1,2,3,4 cores=1,3,5,7
9295 affects processes 1 through 4 only and places them on the first
9296 four even cores, starting with core #1.
9298 CPU cores are numbered starting from 1. Requires support for
9299 sched_getaffinity(2) and sched_setaffinity(2) system calls.
9301 Multiple cpu_affinity_map options are merged.
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