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] [queue-size=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 The queue-size= option sets the maximum number of queued
457 requests. If the queued requests exceed queue size for more
458 than 3 minutes then squid aborts its operation.
459 The default value is set to 2*numberofchildren/
461 NOTE: NTLM and Negotiate schemes do not support concurrency
462 in the Squid code module even though some helpers can.
465 IF HAVE_AUTH_MODULE_BASIC
466 === Basic authentication parameters ===
469 HTTP uses iso-latin-1 as character set, while some
470 authentication backends such as LDAP expects UTF-8. If this is
471 set to on Squid will translate the HTTP iso-latin-1 charset to
472 UTF-8 before sending the username and password to the helper.
474 "credentialsttl" timetolive
475 Specifies how long squid assumes an externally validated
476 username:password pair is valid for - in other words how
477 often the helper program is called for that user. Set this
478 low to force revalidation with short lived passwords.
480 NOTE: setting this high does not impact your susceptibility
481 to replay attacks unless you are using an one-time password
482 system (such as SecureID). If you are using such a system,
483 you will be vulnerable to replay attacks unless you also
484 use the max_user_ip ACL in an http_access rule.
486 "casesensitive" on|off
487 Specifies if usernames are case sensitive. Most user databases
488 are case insensitive allowing the same username to be spelled
489 using both lower and upper case letters, but some are case
490 sensitive. This makes a big difference for user_max_ip ACL
491 processing and similar.
494 IF HAVE_AUTH_MODULE_DIGEST
495 === Digest authentication parameters ===
498 HTTP uses iso-latin-1 as character set, while some
499 authentication backends such as LDAP expects UTF-8. If this is
500 set to on Squid will translate the HTTP iso-latin-1 charset to
501 UTF-8 before sending the username and password to the helper.
503 "nonce_garbage_interval" timeinterval
504 Specifies the interval that nonces that have been issued
505 to client_agent's are checked for validity.
507 "nonce_max_duration" timeinterval
508 Specifies the maximum length of time a given nonce will be
511 "nonce_max_count" number
512 Specifies the maximum number of times a given nonce can be
515 "nonce_strictness" on|off
516 Determines if squid requires strict increment-by-1 behavior
517 for nonce counts, or just incrementing (off - for use when
518 user agents generate nonce counts that occasionally miss 1
519 (ie, 1,2,4,6)). Default off.
521 "check_nonce_count" on|off
522 This directive if set to off can disable the nonce count check
523 completely to work around buggy digest qop implementations in
524 certain mainstream browser versions. Default on to check the
525 nonce count to protect from authentication replay attacks.
527 "post_workaround" on|off
528 This is a workaround to certain buggy browsers who send an
529 incorrect request digest in POST requests when reusing the
530 same nonce as acquired earlier on a GET request.
533 IF HAVE_AUTH_MODULE_NEGOTIATE
534 === Negotiate authentication parameters ===
537 If you experience problems with PUT/POST requests when using
538 the this authentication scheme then you can try setting this
539 to off. This will cause Squid to forcibly close the connection
540 on the initial request where the browser asks which schemes
541 are supported by the proxy.
544 IF HAVE_AUTH_MODULE_NTLM
545 === NTLM authentication parameters ===
548 If you experience problems with PUT/POST requests when using
549 the this authentication scheme then you can try setting this
550 to off. This will cause Squid to forcibly close the connection
551 on the initial request where the browser asks which schemes
552 are supported by the proxy.
555 === Example Configuration ===
557 This configuration displays the recommended authentication scheme
558 order from most to least secure with recommended minimum configuration
559 settings for each scheme:
561 #auth_param negotiate program <uncomment and complete this line to activate>
562 #auth_param negotiate children 20 startup=0 idle=1
563 #auth_param negotiate keep_alive on
565 #auth_param digest program <uncomment and complete this line to activate>
566 #auth_param digest children 20 startup=0 idle=1
567 #auth_param digest realm Squid proxy-caching web server
568 #auth_param digest nonce_garbage_interval 5 minutes
569 #auth_param digest nonce_max_duration 30 minutes
570 #auth_param digest nonce_max_count 50
572 #auth_param ntlm program <uncomment and complete this line to activate>
573 #auth_param ntlm children 20 startup=0 idle=1
574 #auth_param ntlm keep_alive on
576 #auth_param basic program <uncomment and complete this line>
577 #auth_param basic children 5 startup=5 idle=1
578 #auth_param basic realm Squid proxy-caching web server
579 #auth_param basic credentialsttl 2 hours
582 NAME: authenticate_cache_garbage_interval
585 LOC: Config.authenticateGCInterval
587 The time period between garbage collection across the username cache.
588 This is a trade-off between memory utilization (long intervals - say
589 2 days) and CPU (short intervals - say 1 minute). Only change if you
593 NAME: authenticate_ttl
596 LOC: Config.authenticateTTL
598 The time a user & their credentials stay in the logged in
599 user cache since their last request. When the garbage
600 interval passes, all user credentials that have passed their
601 TTL are removed from memory.
604 NAME: authenticate_ip_ttl
606 LOC: Config.authenticateIpTTL
609 If you use proxy authentication and the 'max_user_ip' ACL,
610 this directive controls how long Squid remembers the IP
611 addresses associated with each user. Use a small value
612 (e.g., 60 seconds) if your users might change addresses
613 quickly, as is the case with dialup. You might be safe
614 using a larger value (e.g., 2 hours) in a corporate LAN
615 environment with relatively static address assignments.
620 -----------------------------------------------------------------------------
623 NAME: external_acl_type
624 TYPE: externalAclHelper
625 LOC: Config.externalAclHelperList
628 This option defines external acl classes using a helper program
629 to look up the status
631 external_acl_type name [options] FORMAT.. /path/to/helper [helper arguments..]
635 ttl=n TTL in seconds for cached results (defaults to 3600
638 TTL for cached negative lookups (default same
641 Maximum number of acl helper processes spawned to service
642 external acl lookups of this type. (default 20)
644 Minimum number of acl helper processes to spawn during
645 startup and reconfigure to service external acl lookups
646 of this type. (default 0)
648 Number of acl helper processes to keep ahead of traffic
649 loads. Squid will spawn this many at once whenever load
650 rises above the capabilities of existing processes.
651 Up to the value of children-max. (default 1)
652 concurrency=n concurrency level per process. Only used with helpers
653 capable of processing more than one query at a time.
654 queue-size=N The queue-size= option sets the maximum number of queued
655 requests. If the queued requests exceed queue size
657 The default value is set to 2*children-max.
658 cache=n limit the result cache size, default is 262144.
659 grace=n Percentage remaining of TTL where a refresh of a
660 cached entry should be initiated without needing to
661 wait for a new reply. (default is for no grace period)
662 protocol=2.5 Compatibility mode for Squid-2.5 external acl helpers
663 ipv4 / ipv6 IP protocol used to communicate with this helper.
664 The default is to auto-detect IPv6 and use it when available.
666 FORMAT specifications
668 %LOGIN Authenticated user login name
669 %EXT_USER Username from previous external acl
670 %EXT_LOG Log details from previous external acl
671 %EXT_TAG Tag from previous external acl
672 %IDENT Ident user name
674 %SRCPORT Client source port
677 %PROTO Requested URL scheme
679 %PATH Requested URL path
680 %METHOD Request method
681 %MYADDR Squid interface address
682 %MYPORT Squid http_port number
683 %PATH Requested URL-path (including query-string if any)
684 %USER_CERT SSL User certificate in PEM format
685 %USER_CERTCHAIN SSL User certificate chain in PEM format
686 %USER_CERT_xx SSL User certificate subject attribute xx
687 %USER_CA_CERT_xx SSL User certificate issuer attribute xx
688 %ssl::>sni SSL client SNI sent to Squid
689 %ssl::<cert_subject SSL server certificate DN
690 %ssl::<cert_issuer SSL server certificate issuer DN
692 %>{Header} HTTP request header "Header"
694 HTTP request header "Hdr" list member "member"
696 HTTP request header list member using ; as
697 list separator. ; can be any non-alphanumeric
700 %<{Header} HTTP reply header "Header"
702 HTTP reply header "Hdr" list member "member"
704 HTTP reply header list member using ; as
705 list separator. ; can be any non-alphanumeric
708 %ACL The name of the ACL being tested.
709 %DATA The ACL arguments. If not used then any arguments
710 is automatically added at the end of the line
712 NOTE: this will encode the arguments as one token,
713 whereas the default will pass each separately.
715 %% The percent sign. Useful for helpers which need
716 an unchanging input format.
719 General request syntax:
721 [channel-ID] FORMAT-values [acl-values ...]
724 FORMAT-values consists of transaction details expanded with
725 whitespace separation per the config file FORMAT specification
726 using the FORMAT macros listed above.
728 acl-values consists of any string specified in the referencing
729 config 'acl ... external' line. see the "acl external" directive.
731 Request values sent to the helper are URL escaped to protect
732 each value in requests against whitespaces.
734 If using protocol=2.5 then the request sent to the helper is not
735 URL escaped to protect against whitespace.
737 NOTE: protocol=3.0 is deprecated as no longer necessary.
739 When using the concurrency= option the protocol is changed by
740 introducing a query channel tag in front of the request/response.
741 The query channel tag is a number between 0 and concurrency-1.
742 This value must be echoed back unchanged to Squid as the first part
743 of the response relating to its request.
746 The helper receives lines expanded per the above format specification
747 and for each input line returns 1 line starting with OK/ERR/BH result
748 code and optionally followed by additional keywords with more details.
751 General result syntax:
753 [channel-ID] result keyword=value ...
755 Result consists of one of the codes:
758 the ACL test produced a match.
761 the ACL test does not produce a match.
764 An internal error occurred in the helper, preventing
765 a result being identified.
767 The meaning of 'a match' is determined by your squid.conf
768 access control configuration. See the Squid wiki for details.
772 user= The users name (login)
774 password= The users password (for login= cache_peer option)
776 message= Message describing the reason for this response.
777 Available as %o in error pages.
778 Useful on (ERR and BH results).
780 tag= Apply a tag to a request. Only sets a tag once,
781 does not alter existing tags.
783 log= String to be logged in access.log. Available as
784 %ea in logformat specifications.
786 clt_conn_tag= Associates a TAG with the client TCP connection.
787 Please see url_rewrite_program related documentation for
790 Any keywords may be sent on any response whether OK, ERR or BH.
792 All response keyword values need to be a single token with URL
793 escaping, or enclosed in double quotes (") and escaped using \ on
794 any double quotes or \ characters within the value. The wrapping
795 double quotes are removed before the value is interpreted by Squid.
796 \r and \n are also replace by CR and LF.
798 Some example key values:
802 user="J. \"Bob\" Smith"
809 DEFAULT: ssl::certHasExpired ssl_error X509_V_ERR_CERT_HAS_EXPIRED
810 DEFAULT: ssl::certNotYetValid ssl_error X509_V_ERR_CERT_NOT_YET_VALID
811 DEFAULT: ssl::certDomainMismatch ssl_error SQUID_X509_V_ERR_DOMAIN_MISMATCH
812 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
813 DEFAULT: ssl::certSelfSigned ssl_error X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT
816 DEFAULT: manager url_regex -i ^cache_object:// +i ^https?://[^/]+/squid-internal-mgr/
817 DEFAULT: localhost src 127.0.0.1/32 ::1
818 DEFAULT: to_localhost dst 127.0.0.0/8 0.0.0.0/32 ::1
819 DEFAULT_DOC: ACLs all, manager, localhost, and to_localhost are predefined.
821 Defining an Access List
823 Every access list definition must begin with an aclname and acltype,
824 followed by either type-specific arguments or a quoted filename that
827 acl aclname acltype argument ...
828 acl aclname acltype "file" ...
830 When using "file", the file should contain one item per line.
832 Some acl types supports options which changes their default behaviour.
833 The available options are:
835 -i,+i By default, regular expressions are CASE-SENSITIVE. To make them
836 case-insensitive, use the -i option. To return case-sensitive
837 use the +i option between patterns, or make a new ACL line
840 -n Disable lookups and address type conversions. If lookup or
841 conversion is required because the parameter type (IP or
842 domain name) does not match the message address type (domain
843 name or IP), then the ACL would immediately declare a mismatch
844 without any warnings or lookups.
846 -- Used to stop processing all options, in the case the first acl
847 value has '-' character as first character (for example the '-'
848 is a valid domain name)
850 Some acl types require suspending the current request in order
851 to access some external data source.
852 Those which do are marked with the tag [slow], those which
853 don't are marked as [fast].
854 See http://wiki.squid-cache.org/SquidFaq/SquidAcl
855 for further information
857 ***** ACL TYPES AVAILABLE *****
859 acl aclname src ip-address/mask ... # clients IP address [fast]
860 acl aclname src addr1-addr2/mask ... # range of addresses [fast]
861 acl aclname dst [-n] ip-address/mask ... # URL host's IP address [slow]
862 acl aclname localip ip-address/mask ... # IP address the client connected to [fast]
864 acl aclname arp mac-address ... (xx:xx:xx:xx:xx:xx notation)
865 # The arp ACL requires the special configure option --enable-arp-acl.
866 # Furthermore, the ARP ACL code is not portable to all operating systems.
867 # It works on Linux, Solaris, Windows, FreeBSD, and some
868 # other *BSD variants.
871 # NOTE: Squid can only determine the MAC address for clients that are on
872 # the same subnet. If the client is on a different subnet,
873 # then Squid cannot find out its MAC address.
875 acl aclname srcdomain .foo.com ...
876 # reverse lookup, from client IP [slow]
877 acl aclname dstdomain [-n] .foo.com ...
878 # Destination server from URL [fast]
879 acl aclname srcdom_regex [-i] \.foo\.com ...
880 # regex matching client name [slow]
881 acl aclname dstdom_regex [-n] [-i] \.foo\.com ...
882 # regex matching server [fast]
884 # For dstdomain and dstdom_regex a reverse lookup is tried if a IP
885 # based URL is used and no match is found. The name "none" is used
886 # if the reverse lookup fails.
888 acl aclname src_as number ...
889 acl aclname dst_as number ...
891 # Except for access control, AS numbers can be used for
892 # routing of requests to specific caches. Here's an
893 # example for routing all requests for AS#1241 and only
894 # those to mycache.mydomain.net:
895 # acl asexample dst_as 1241
896 # cache_peer_access mycache.mydomain.net allow asexample
897 # cache_peer_access mycache_mydomain.net deny all
899 acl aclname peername myPeer ...
901 # match against a named cache_peer entry
902 # set unique name= on cache_peer lines for reliable use.
904 acl aclname time [day-abbrevs] [h1:m1-h2:m2]
914 # h1:m1 must be less than h2:m2
916 acl aclname url_regex [-i] ^http:// ...
917 # regex matching on whole URL [fast]
918 acl aclname urllogin [-i] [^a-zA-Z0-9] ...
919 # regex matching on URL login field
920 acl aclname urlpath_regex [-i] \.gif$ ...
921 # regex matching on URL path [fast]
923 acl aclname port 80 70 21 0-1024... # destination TCP port [fast]
925 acl aclname localport 3128 ... # TCP port the client connected to [fast]
926 # NP: for interception mode this is usually '80'
928 acl aclname myportname 3128 ... # *_port name [fast]
930 acl aclname proto HTTP FTP ... # request protocol [fast]
932 acl aclname method GET POST ... # HTTP request method [fast]
934 acl aclname http_status 200 301 500- 400-403 ...
935 # status code in reply [fast]
937 acl aclname browser [-i] regexp ...
938 # pattern match on User-Agent header (see also req_header below) [fast]
940 acl aclname referer_regex [-i] regexp ...
941 # pattern match on Referer header [fast]
942 # Referer is highly unreliable, so use with care
944 acl aclname ident username ...
945 acl aclname ident_regex [-i] pattern ...
946 # string match on ident output [slow]
947 # use REQUIRED to accept any non-null ident.
949 acl aclname proxy_auth [-i] username ...
950 acl aclname proxy_auth_regex [-i] pattern ...
951 # perform http authentication challenge to the client and match against
952 # supplied credentials [slow]
954 # takes a list of allowed usernames.
955 # use REQUIRED to accept any valid username.
957 # Will use proxy authentication in forward-proxy scenarios, and plain
958 # http authenticaiton in reverse-proxy scenarios
960 # NOTE: when a Proxy-Authentication header is sent but it is not
961 # needed during ACL checking the username is NOT logged
964 # NOTE: proxy_auth requires a EXTERNAL authentication program
965 # to check username/password combinations (see
966 # auth_param directive).
968 # NOTE: proxy_auth can't be used in a transparent/intercepting proxy
969 # as the browser needs to be configured for using a proxy in order
970 # to respond to proxy authentication.
972 acl aclname snmp_community string ...
973 # A community string to limit access to your SNMP Agent [fast]
976 # acl snmppublic snmp_community public
978 acl aclname maxconn number
979 # This will be matched when the client's IP address has
980 # more than <number> TCP connections established. [fast]
981 # NOTE: This only measures direct TCP links so X-Forwarded-For
982 # indirect clients are not counted.
984 acl aclname max_user_ip [-s] number
985 # This will be matched when the user attempts to log in from more
986 # than <number> different ip addresses. The authenticate_ip_ttl
987 # parameter controls the timeout on the ip entries. [fast]
988 # If -s is specified the limit is strict, denying browsing
989 # from any further IP addresses until the ttl has expired. Without
990 # -s Squid will just annoy the user by "randomly" denying requests.
991 # (the counter is reset each time the limit is reached and a
993 # NOTE: in acceleration mode or where there is mesh of child proxies,
994 # clients may appear to come from multiple addresses if they are
995 # going through proxy farms, so a limit of 1 may cause user problems.
997 acl aclname random probability
998 # Pseudo-randomly match requests. Based on the probability given.
999 # Probability may be written as a decimal (0.333), fraction (1/3)
1000 # or ratio of matches:non-matches (3:5).
1002 acl aclname req_mime_type [-i] mime-type ...
1003 # regex match against the mime type of the request generated
1004 # by the client. Can be used to detect file upload or some
1005 # types HTTP tunneling requests [fast]
1006 # NOTE: This does NOT match the reply. You cannot use this
1007 # to match the returned file type.
1009 acl aclname req_header header-name [-i] any\.regex\.here
1010 # regex match against any of the known request headers. May be
1011 # thought of as a superset of "browser", "referer" and "mime-type"
1014 acl aclname rep_mime_type [-i] mime-type ...
1015 # regex match against the mime type of the reply received by
1016 # squid. Can be used to detect file download or some
1017 # types HTTP tunneling requests. [fast]
1018 # NOTE: This has no effect in http_access rules. It only has
1019 # effect in rules that affect the reply data stream such as
1020 # http_reply_access.
1022 acl aclname rep_header header-name [-i] any\.regex\.here
1023 # regex match against any of the known reply headers. May be
1024 # thought of as a superset of "browser", "referer" and "mime-type"
1027 acl aclname external class_name [arguments...]
1028 # external ACL lookup via a helper class defined by the
1029 # external_acl_type directive [slow]
1031 acl aclname user_cert attribute values...
1032 # match against attributes in a user SSL certificate
1033 # attribute is one of DN/C/O/CN/L/ST [fast]
1035 acl aclname ca_cert attribute values...
1036 # match against attributes a users issuing CA SSL certificate
1037 # attribute is one of DN/C/O/CN/L/ST [fast]
1039 acl aclname ext_user username ...
1040 acl aclname ext_user_regex [-i] pattern ...
1041 # string match on username returned by external acl helper [slow]
1042 # use REQUIRED to accept any non-null user name.
1044 acl aclname tag tagvalue ...
1045 # string match on tag returned by external acl helper [fast]
1046 # DEPRECATED. Only the first tag will match with this ACL.
1047 # Use the 'note' ACL instead for handling multiple tag values.
1049 acl aclname hier_code codename ...
1050 # string match against squid hierarchy code(s); [fast]
1051 # e.g., DIRECT, PARENT_HIT, NONE, etc.
1053 # NOTE: This has no effect in http_access rules. It only has
1054 # effect in rules that affect the reply data stream such as
1055 # http_reply_access.
1057 acl aclname note name [value ...]
1058 # match transaction annotation [fast]
1059 # Without values, matches any annotation with a given name.
1060 # With value(s), matches any annotation with a given name that
1061 # also has one of the given values.
1062 # Names and values are compared using a string equality test.
1063 # Annotation sources include note and adaptation_meta directives
1064 # as well as helper and eCAP responses.
1066 acl aclname adaptation_service service ...
1067 # Matches the name of any icap_service, ecap_service,
1068 # adaptation_service_set, or adaptation_service_chain that Squid
1069 # has used (or attempted to use) for the master transaction.
1070 # This ACL must be defined after the corresponding adaptation
1071 # service is named in squid.conf. This ACL is usable with
1072 # adaptation_meta because it starts matching immediately after
1073 # the service has been selected for adaptation.
1076 acl aclname ssl_error errorname
1077 # match against SSL certificate validation error [fast]
1079 # For valid error names see in @DEFAULT_ERROR_DIR@/templates/error-details.txt
1082 # The following can be used as shortcuts for certificate properties:
1083 # [ssl::]certHasExpired: the "not after" field is in the past
1084 # [ssl::]certNotYetValid: the "not before" field is in the future
1085 # [ssl::]certUntrusted: The certificate issuer is not to be trusted.
1086 # [ssl::]certSelfSigned: The certificate is self signed.
1087 # [ssl::]certDomainMismatch: The certificate CN domain does not
1088 # match the name the name of the host we are connecting to.
1090 # The ssl::certHasExpired, ssl::certNotYetValid, ssl::certDomainMismatch,
1091 # ssl::certUntrusted, and ssl::certSelfSigned can also be used as
1092 # predefined ACLs, just like the 'all' ACL.
1094 # NOTE: The ssl_error ACL is only supported with sslproxy_cert_error,
1095 # sslproxy_cert_sign, and sslproxy_cert_adapt options.
1097 acl aclname server_cert_fingerprint [-sha1] fingerprint
1098 # match against server SSL certificate fingerprint [fast]
1100 # The fingerprint is the digest of the DER encoded version
1101 # of the whole certificate. The user should use the form: XX:XX:...
1102 # Optional argument specifies the digest algorithm to use.
1103 # The SHA1 digest algorithm is the default and is currently
1104 # the only algorithm supported (-sha1).
1106 acl aclname at_step step
1107 # match against the current step during ssl_bump evaluation [fast]
1108 # Never matches and should not be used outside the ssl_bump context.
1110 # At each SslBump step, Squid evaluates ssl_bump directives to find
1111 # the next bumping action (e.g., peek or splice). Valid SslBump step
1112 # values and the corresponding ssl_bump evaluation moments are:
1113 # SslBump1: After getting TCP-level and HTTP CONNECT info.
1114 # SslBump2: After getting SSL Client Hello info.
1115 # SslBump3: After getting SSL Server Hello info.
1117 acl aclname any-of acl1 acl2 ...
1118 # match any one of the acls [fast or slow]
1119 # The first matching ACL stops further ACL evaluation.
1121 # ACLs from multiple any-of lines with the same name are ORed.
1122 # For example, A = (a1 or a2) or (a3 or a4) can be written as
1123 # acl A any-of a1 a2
1124 # acl A any-of a3 a4
1126 # This group ACL is fast if all evaluated ACLs in the group are fast
1127 # and slow otherwise.
1129 acl aclname all-of acl1 acl2 ...
1130 # match all of the acls [fast or slow]
1131 # The first mismatching ACL stops further ACL evaluation.
1133 # ACLs from multiple all-of lines with the same name are ORed.
1134 # For example, B = (b1 and b2) or (b3 and b4) can be written as
1135 # acl B all-of b1 b2
1136 # acl B all-of b3 b4
1138 # This group ACL is fast if all evaluated ACLs in the group are fast
1139 # and slow otherwise.
1142 acl macaddress arp 09:00:2b:23:45:67
1143 acl myexample dst_as 1241
1144 acl password proxy_auth REQUIRED
1145 acl fileupload req_mime_type -i ^multipart/form-data$
1146 acl javascript rep_mime_type -i ^application/x-javascript$
1150 # Recommended minimum configuration:
1153 # Example rule allowing access from your local networks.
1154 # Adapt to list your (internal) IP networks from where browsing
1156 acl localnet src 10.0.0.0/8 # RFC1918 possible internal network
1157 acl localnet src 172.16.0.0/12 # RFC1918 possible internal network
1158 acl localnet src 192.168.0.0/16 # RFC1918 possible internal network
1159 acl localnet src fc00::/7 # RFC 4193 local private network range
1160 acl localnet src fe80::/10 # RFC 4291 link-local (directly plugged) machines
1162 acl SSL_ports port 443
1163 acl Safe_ports port 80 # http
1164 acl Safe_ports port 21 # ftp
1165 acl Safe_ports port 443 # https
1166 acl Safe_ports port 70 # gopher
1167 acl Safe_ports port 210 # wais
1168 acl Safe_ports port 1025-65535 # unregistered ports
1169 acl Safe_ports port 280 # http-mgmt
1170 acl Safe_ports port 488 # gss-http
1171 acl Safe_ports port 591 # filemaker
1172 acl Safe_ports port 777 # multiling http
1173 acl CONNECT method CONNECT
1177 NAME: proxy_protocol_access
1179 LOC: Config.accessList.proxyProtocol
1181 DEFAULT_DOC: all TCP connections to ports with require-proxy-header will be denied
1183 Determine which client proxies can be trusted to provide correct
1184 information regarding real client IP address using PROXY protocol.
1186 Requests may pass through a chain of several other proxies
1187 before reaching us. The original source details may by sent in:
1188 * HTTP message Forwarded header, or
1189 * HTTP message X-Forwarded-For header, or
1190 * PROXY protocol connection header.
1192 This directive is solely for validating new PROXY protocol
1193 connections received from a port flagged with require-proxy-header.
1194 It is checked only once after TCP connection setup.
1196 A deny match results in TCP connection closure.
1198 An allow match is required for Squid to permit the corresponding
1199 TCP connection, before Squid even looks for HTTP request headers.
1200 If there is an allow match, Squid starts using PROXY header information
1201 to determine the source address of the connection for all future ACL
1202 checks, logging, etc.
1204 SECURITY CONSIDERATIONS:
1206 Any host from which we accept client IP details can place
1207 incorrect information in the relevant header, and Squid
1208 will use the incorrect information as if it were the
1209 source address of the request. This may enable remote
1210 hosts to bypass any access control restrictions that are
1211 based on the client's source addresses.
1213 This clause only supports fast acl types.
1214 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1217 NAME: follow_x_forwarded_for
1219 IFDEF: FOLLOW_X_FORWARDED_FOR
1220 LOC: Config.accessList.followXFF
1221 DEFAULT_IF_NONE: deny all
1222 DEFAULT_DOC: X-Forwarded-For header will be ignored.
1224 Determine which client proxies can be trusted to provide correct
1225 information regarding real client IP address.
1227 Requests may pass through a chain of several other proxies
1228 before reaching us. The original source details may by sent in:
1229 * HTTP message Forwarded header, or
1230 * HTTP message X-Forwarded-For header, or
1231 * PROXY protocol connection header.
1233 PROXY protocol connections are controlled by the proxy_protocol_access
1234 directive which is checked before this.
1236 If a request reaches us from a source that is allowed by this
1237 directive, then we trust the information it provides regarding
1238 the IP of the client it received from (if any).
1240 For the purpose of ACLs used in this directive the src ACL type always
1241 matches the address we are testing and srcdomain matches its rDNS.
1243 On each HTTP request Squid checks for X-Forwarded-For header fields.
1244 If found the header values are iterated in reverse order and an allow
1245 match is required for Squid to continue on to the next value.
1246 The verification ends when a value receives a deny match, cannot be
1247 tested, or there are no more values to test.
1248 NOTE: Squid does not yet follow the Forwarded HTTP header.
1250 The end result of this process is an IP address that we will
1251 refer to as the indirect client address. This address may
1252 be treated as the client address for access control, ICAP, delay
1253 pools and logging, depending on the acl_uses_indirect_client,
1254 icap_uses_indirect_client, delay_pool_uses_indirect_client,
1255 log_uses_indirect_client and tproxy_uses_indirect_client options.
1257 This clause only supports fast acl types.
1258 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1260 SECURITY CONSIDERATIONS:
1262 Any host from which we accept client IP details can place
1263 incorrect information in the relevant header, and Squid
1264 will use the incorrect information as if it were the
1265 source address of the request. This may enable remote
1266 hosts to bypass any access control restrictions that are
1267 based on the client's source addresses.
1271 acl localhost src 127.0.0.1
1272 acl my_other_proxy srcdomain .proxy.example.com
1273 follow_x_forwarded_for allow localhost
1274 follow_x_forwarded_for allow my_other_proxy
1277 NAME: acl_uses_indirect_client
1280 IFDEF: FOLLOW_X_FORWARDED_FOR
1282 LOC: Config.onoff.acl_uses_indirect_client
1284 Controls whether the indirect client address
1285 (see follow_x_forwarded_for) is used instead of the
1286 direct client address in acl matching.
1288 NOTE: maxconn ACL considers direct TCP links and indirect
1289 clients will always have zero. So no match.
1292 NAME: delay_pool_uses_indirect_client
1295 IFDEF: FOLLOW_X_FORWARDED_FOR&&USE_DELAY_POOLS
1297 LOC: Config.onoff.delay_pool_uses_indirect_client
1299 Controls whether the indirect client address
1300 (see follow_x_forwarded_for) is used instead of the
1301 direct client address in delay pools.
1304 NAME: log_uses_indirect_client
1307 IFDEF: FOLLOW_X_FORWARDED_FOR
1309 LOC: Config.onoff.log_uses_indirect_client
1311 Controls whether the indirect client address
1312 (see follow_x_forwarded_for) is used instead of the
1313 direct client address in the access log.
1316 NAME: tproxy_uses_indirect_client
1319 IFDEF: FOLLOW_X_FORWARDED_FOR&&LINUX_NETFILTER
1321 LOC: Config.onoff.tproxy_uses_indirect_client
1323 Controls whether the indirect client address
1324 (see follow_x_forwarded_for) is used instead of the
1325 direct client address when spoofing the outgoing client.
1327 This has no effect on requests arriving in non-tproxy
1330 SECURITY WARNING: Usage of this option is dangerous
1331 and should not be used trivially. Correct configuration
1332 of follow_x_forewarded_for with a limited set of trusted
1333 sources is required to prevent abuse of your proxy.
1336 NAME: spoof_client_ip
1338 LOC: Config.accessList.spoof_client_ip
1340 DEFAULT_DOC: Allow spoofing on all TPROXY traffic.
1342 Control client IP address spoofing of TPROXY traffic based on
1343 defined access lists.
1345 spoof_client_ip allow|deny [!]aclname ...
1347 If there are no "spoof_client_ip" lines present, the default
1348 is to "allow" spoofing of any suitable request.
1350 Note that the cache_peer "no-tproxy" option overrides this ACL.
1352 This clause supports fast acl types.
1353 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1358 LOC: Config.accessList.http
1359 DEFAULT_IF_NONE: deny all
1360 DEFAULT_DOC: Deny, unless rules exist in squid.conf.
1362 Allowing or Denying access based on defined access lists
1364 To allow or deny a message received on an HTTP, HTTPS, or FTP port:
1365 http_access allow|deny [!]aclname ...
1367 NOTE on default values:
1369 If there are no "access" lines present, the default is to deny
1372 If none of the "access" lines cause a match, the default is the
1373 opposite of the last line in the list. If the last line was
1374 deny, the default is allow. Conversely, if the last line
1375 is allow, the default will be deny. For these reasons, it is a
1376 good idea to have an "deny all" entry at the end of your access
1377 lists to avoid potential confusion.
1379 This clause supports both fast and slow acl types.
1380 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1385 # Recommended minimum Access Permission configuration:
1387 # Deny requests to certain unsafe ports
1388 http_access deny !Safe_ports
1390 # Deny CONNECT to other than secure SSL ports
1391 http_access deny CONNECT !SSL_ports
1393 # Only allow cachemgr access from localhost
1394 http_access allow localhost manager
1395 http_access deny manager
1397 # We strongly recommend the following be uncommented to protect innocent
1398 # web applications running on the proxy server who think the only
1399 # one who can access services on "localhost" is a local user
1400 #http_access deny to_localhost
1403 # INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS
1406 # Example rule allowing access from your local networks.
1407 # Adapt localnet in the ACL section to list your (internal) IP networks
1408 # from where browsing should be allowed
1409 http_access allow localnet
1410 http_access allow localhost
1412 # And finally deny all other access to this proxy
1413 http_access deny all
1417 NAME: adapted_http_access http_access2
1419 LOC: Config.accessList.adapted_http
1421 DEFAULT_DOC: Allow, unless rules exist in squid.conf.
1423 Allowing or Denying access based on defined access lists
1425 Essentially identical to http_access, but runs after redirectors
1426 and ICAP/eCAP adaptation. Allowing access control based on their
1429 If not set then only http_access is used.
1432 NAME: http_reply_access
1434 LOC: Config.accessList.reply
1436 DEFAULT_DOC: Allow, unless rules exist in squid.conf.
1438 Allow replies to client requests. This is complementary to http_access.
1440 http_reply_access allow|deny [!] aclname ...
1442 NOTE: if there are no access lines present, the default is to allow
1445 If none of the access lines cause a match the opposite of the
1446 last line will apply. Thus it is good practice to end the rules
1447 with an "allow all" or "deny all" entry.
1449 This clause supports both fast and slow acl types.
1450 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1455 LOC: Config.accessList.icp
1457 DEFAULT_DOC: Deny, unless rules exist in squid.conf.
1459 Allowing or Denying access to the ICP port based on defined
1462 icp_access allow|deny [!]aclname ...
1464 NOTE: The default if no icp_access lines are present is to
1465 deny all traffic. This default may cause problems with peers
1468 This clause only supports fast acl types.
1469 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1471 # Allow ICP queries from local networks only
1472 #icp_access allow localnet
1473 #icp_access deny all
1479 LOC: Config.accessList.htcp
1481 DEFAULT_DOC: Deny, unless rules exist in squid.conf.
1483 Allowing or Denying access to the HTCP port based on defined
1486 htcp_access allow|deny [!]aclname ...
1488 See also htcp_clr_access for details on access control for
1489 cache purge (CLR) HTCP messages.
1491 NOTE: The default if no htcp_access lines are present is to
1492 deny all traffic. This default may cause problems with peers
1493 using the htcp option.
1495 This clause only supports fast acl types.
1496 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1498 # Allow HTCP queries from local networks only
1499 #htcp_access allow localnet
1500 #htcp_access deny all
1503 NAME: htcp_clr_access
1506 LOC: Config.accessList.htcp_clr
1508 DEFAULT_DOC: Deny, unless rules exist in squid.conf.
1510 Allowing or Denying access to purge content using HTCP based
1511 on defined access lists.
1512 See htcp_access for details on general HTCP access control.
1514 htcp_clr_access allow|deny [!]aclname ...
1516 This clause only supports fast acl types.
1517 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1519 # Allow HTCP CLR requests from trusted peers
1520 acl htcp_clr_peer src 192.0.2.2 2001:DB8::2
1521 htcp_clr_access allow htcp_clr_peer
1522 htcp_clr_access deny all
1527 LOC: Config.accessList.miss
1529 DEFAULT_DOC: Allow, unless rules exist in squid.conf.
1531 Determins whether network access is permitted when satisfying a request.
1534 to force your neighbors to use you as a sibling instead of
1537 acl localclients src 192.0.2.0/24 2001:DB8::a:0/64
1538 miss_access deny !localclients
1539 miss_access allow all
1541 This means only your local clients are allowed to fetch relayed/MISS
1542 replies from the network and all other clients can only fetch cached
1545 The default for this setting allows all clients who passed the
1546 http_access rules to relay via this proxy.
1548 This clause only supports fast acl types.
1549 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1552 NAME: ident_lookup_access
1556 DEFAULT_DOC: Unless rules exist in squid.conf, IDENT is not fetched.
1557 LOC: Ident::TheConfig.identLookup
1559 A list of ACL elements which, if matched, cause an ident
1560 (RFC 931) lookup to be performed for this request. For
1561 example, you might choose to always perform ident lookups
1562 for your main multi-user Unix boxes, but not for your Macs
1563 and PCs. By default, ident lookups are not performed for
1566 To enable ident lookups for specific client addresses, you
1567 can follow this example:
1569 acl ident_aware_hosts src 198.168.1.0/24
1570 ident_lookup_access allow ident_aware_hosts
1571 ident_lookup_access deny all
1573 Only src type ACL checks are fully supported. A srcdomain
1574 ACL might work at times, but it will not always provide
1577 This clause only supports fast acl types.
1578 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
1581 NAME: reply_body_max_size
1582 COMMENT: size [acl acl...]
1585 DEFAULT_DOC: No limit is applied.
1586 LOC: Config.ReplyBodySize
1588 This option specifies the maximum size of a reply body. It can be
1589 used to prevent users from downloading very large files, such as
1590 MP3's and movies. When the reply headers are received, the
1591 reply_body_max_size lines are processed, and the first line where
1592 all (if any) listed ACLs are true is used as the maximum body size
1595 This size is checked twice. First when we get the reply headers,
1596 we check the content-length value. If the content length value exists
1597 and is larger than the allowed size, the request is denied and the
1598 user receives an error message that says "the request or reply
1599 is too large." If there is no content-length, and the reply
1600 size exceeds this limit, the client's connection is just closed
1601 and they will receive a partial reply.
1603 WARNING: downstream caches probably can not detect a partial reply
1604 if there is no content-length header, so they will cache
1605 partial responses and give them out as hits. You should NOT
1606 use this option if you have downstream caches.
1608 WARNING: A maximum size smaller than the size of squid's error messages
1609 will cause an infinite loop and crash squid. Ensure that the smallest
1610 non-zero value you use is greater that the maximum header size plus
1611 the size of your largest error page.
1613 If you set this parameter none (the default), there will be
1616 Configuration Format is:
1617 reply_body_max_size SIZE UNITS [acl ...]
1619 reply_body_max_size 10 MB
1625 -----------------------------------------------------------------------------
1628 NAME: http_port ascii_port
1633 Usage: port [mode] [options]
1634 hostname:port [mode] [options]
1635 1.2.3.4:port [mode] [options]
1637 The socket addresses where Squid will listen for HTTP client
1638 requests. You may specify multiple socket addresses.
1639 There are three forms: port alone, hostname with port, and
1640 IP address with port. If you specify a hostname or IP
1641 address, Squid binds the socket to that specific
1642 address. Most likely, you do not need to bind to a specific
1643 address, so you can use the port number alone.
1645 If you are running Squid in accelerator mode, you
1646 probably want to listen on port 80 also, or instead.
1648 The -a command line option may be used to specify additional
1649 port(s) where Squid listens for proxy request. Such ports will
1650 be plain proxy ports with no options.
1652 You may specify multiple socket addresses on multiple lines.
1656 intercept Support for IP-Layer interception of
1657 outgoing requests without browser settings.
1658 NP: disables authentication and IPv6 on the port.
1660 tproxy Support Linux TPROXY for spoofing outgoing
1661 connections using the client IP address.
1662 NP: disables authentication and maybe IPv6 on the port.
1664 accel Accelerator / reverse proxy mode
1666 ssl-bump For each CONNECT request allowed by ssl_bump ACLs,
1667 establish secure connection with the client and with
1668 the server, decrypt HTTPS messages as they pass through
1669 Squid, and treat them as unencrypted HTTP messages,
1670 becoming the man-in-the-middle.
1672 The ssl_bump option is required to fully enable
1673 bumping of CONNECT requests.
1675 Omitting the mode flag causes default forward proxy mode to be used.
1678 Accelerator Mode Options:
1680 defaultsite=domainname
1681 What to use for the Host: header if it is not present
1682 in a request. Determines what site (not origin server)
1683 accelerators should consider the default.
1685 no-vhost Disable using HTTP/1.1 Host header for virtual domain support.
1687 protocol= Protocol to reconstruct accelerated and intercepted
1688 requests with. Defaults to HTTP/1.1 for http_port and
1689 HTTPS/1.1 for https_port.
1690 When an unsupported value is configured Squid will
1691 produce a FATAL error.
1692 Values: HTTP or HTTP/1.1, HTTPS or HTTPS/1.1
1694 vport Virtual host port support. Using the http_port number
1695 instead of the port passed on Host: headers.
1697 vport=NN Virtual host port support. Using the specified port
1698 number instead of the port passed on Host: headers.
1701 Act as if this Squid is the origin server.
1702 This currently means generate new Date: and Expires:
1703 headers on HIT instead of adding Age:.
1705 ignore-cc Ignore request Cache-Control headers.
1707 WARNING: This option violates HTTP specifications if
1708 used in non-accelerator setups.
1710 allow-direct Allow direct forwarding in accelerator mode. Normally
1711 accelerated requests are denied direct forwarding as if
1712 never_direct was used.
1714 WARNING: this option opens accelerator mode to security
1715 vulnerabilities usually only affecting in interception
1716 mode. Make sure to protect forwarding with suitable
1717 http_access rules when using this.
1720 SSL Bump Mode Options:
1721 In addition to these options ssl-bump requires TLS/SSL options.
1723 generate-host-certificates[=<on|off>]
1724 Dynamically create SSL server certificates for the
1725 destination hosts of bumped CONNECT requests.When
1726 enabled, the cert and key options are used to sign
1727 generated certificates. Otherwise generated
1728 certificate will be selfsigned.
1729 If there is a CA certificate lifetime of the generated
1730 certificate equals lifetime of the CA certificate. If
1731 generated certificate is selfsigned lifetime is three
1733 This option is enabled by default when ssl-bump is used.
1734 See the ssl-bump option above for more information.
1736 dynamic_cert_mem_cache_size=SIZE
1737 Approximate total RAM size spent on cached generated
1738 certificates. If set to zero, caching is disabled. The
1739 default value is 4MB.
1743 cert= Path to SSL certificate (PEM format).
1745 key= Path to SSL private key file (PEM format)
1746 if not specified, the certificate file is
1747 assumed to be a combined certificate and
1750 version= The version of SSL/TLS supported
1751 1 automatic (default)
1757 cipher= Colon separated list of supported ciphers.
1758 NOTE: some ciphers such as EDH ciphers depend on
1759 additional settings. If those settings are
1760 omitted the ciphers may be silently ignored
1761 by the OpenSSL library.
1763 options= Various SSL implementation options. The most important
1765 NO_SSLv3 Disallow the use of SSLv3
1766 NO_TLSv1 Disallow the use of TLSv1.0
1767 NO_TLSv1_1 Disallow the use of TLSv1.1
1768 NO_TLSv1_2 Disallow the use of TLSv1.2
1769 SINGLE_DH_USE Always create a new key when using
1770 temporary/ephemeral DH key exchanges
1771 ALL Enable various bug workarounds
1772 suggested as "harmless" by OpenSSL
1773 Be warned that this reduces SSL/TLS
1774 strength to some attacks.
1775 See OpenSSL SSL_CTX_set_options documentation for a
1776 complete list of options.
1778 clientca= File containing the list of CAs to use when
1779 requesting a client certificate.
1781 cafile= File containing additional CA certificates to
1782 use when verifying client certificates. If unset
1783 clientca will be used.
1785 capath= Directory containing additional CA certificates
1786 and CRL lists to use when verifying client certificates.
1788 crlfile= File of additional CRL lists to use when verifying
1789 the client certificate, in addition to CRLs stored in
1790 the capath. Implies VERIFY_CRL flag below.
1792 dhparams= File containing DH parameters for temporary/ephemeral
1793 DH key exchanges. See OpenSSL documentation for details
1794 on how to create this file.
1795 WARNING: EDH ciphers will be silently disabled if this
1798 sslflags= Various flags modifying the use of SSL:
1800 Don't request client certificates
1801 immediately, but wait until acl processing
1802 requires a certificate (not yet implemented).
1804 Don't use the default CA lists built in
1807 Don't allow for session reuse. Each connection
1808 will result in a new SSL session.
1810 Verify CRL lists when accepting client
1813 Verify CRL lists for all certificates in the
1814 client certificate chain.
1816 sslcontext= SSL session ID context identifier.
1820 connection-auth[=on|off]
1821 use connection-auth=off to tell Squid to prevent
1822 forwarding Microsoft connection oriented authentication
1823 (NTLM, Negotiate and Kerberos)
1825 disable-pmtu-discovery=
1826 Control Path-MTU discovery usage:
1827 off lets OS decide on what to do (default).
1828 transparent disable PMTU discovery when transparent
1830 always disable always PMTU discovery.
1832 In many setups of transparently intercepting proxies
1833 Path-MTU discovery can not work on traffic towards the
1834 clients. This is the case when the intercepting device
1835 does not fully track connections and fails to forward
1836 ICMP must fragment messages to the cache server. If you
1837 have such setup and experience that certain clients
1838 sporadically hang or never complete requests set
1839 disable-pmtu-discovery option to 'transparent'.
1841 name= Specifies a internal name for the port. Defaults to
1842 the port specification (port or addr:port)
1844 tcpkeepalive[=idle,interval,timeout]
1845 Enable TCP keepalive probes of idle connections.
1846 In seconds; idle is the initial time before TCP starts
1847 probing the connection, interval how often to probe, and
1848 timeout the time before giving up.
1850 require-proxy-header
1851 Require PROXY protocol version 1 or 2 connections.
1852 The proxy_protocol_access is required to whitelist
1853 downstream proxies which can be trusted.
1855 If you run Squid on a dual-homed machine with an internal
1856 and an external interface we recommend you to specify the
1857 internal address:port in http_port. This way Squid will only be
1858 visible on the internal address.
1862 # Squid normally listens to port 3128
1863 http_port @DEFAULT_HTTP_PORT@
1873 Usage: [ip:]port cert=certificate.pem [key=key.pem] [mode] [options...]
1875 The socket address where Squid will listen for client requests made
1876 over TLS or SSL connections. Commonly referred to as HTTPS.
1878 This is most useful for situations where you are running squid in
1879 accelerator mode and you want to do the SSL work at the accelerator level.
1881 You may specify multiple socket addresses on multiple lines,
1882 each with their own SSL certificate and/or options.
1886 accel Accelerator / reverse proxy mode
1888 intercept Support for IP-Layer interception of
1889 outgoing requests without browser settings.
1890 NP: disables authentication and IPv6 on the port.
1892 tproxy Support Linux TPROXY for spoofing outgoing
1893 connections using the client IP address.
1894 NP: disables authentication and maybe IPv6 on the port.
1896 ssl-bump For each intercepted connection allowed by ssl_bump
1897 ACLs, establish a secure connection with the client and with
1898 the server, decrypt HTTPS messages as they pass through
1899 Squid, and treat them as unencrypted HTTP messages,
1900 becoming the man-in-the-middle.
1902 An "ssl_bump server-first" match is required to
1903 fully enable bumping of intercepted SSL connections.
1905 Requires tproxy or intercept.
1907 Omitting the mode flag causes default forward proxy mode to be used.
1910 See http_port for a list of generic options
1915 cert= Path to SSL certificate (PEM format).
1917 key= Path to SSL private key file (PEM format)
1918 if not specified, the certificate file is
1919 assumed to be a combined certificate and
1922 version= The version of SSL/TLS supported
1923 1 automatic (default)
1927 cipher= Colon separated list of supported ciphers.
1929 options= Various SSL engine options. The most important
1931 NO_SSLv3 Disallow the use of SSLv3
1932 NO_TLSv1 Disallow the use of TLSv1
1933 SINGLE_DH_USE Always create a new key when using
1934 temporary/ephemeral DH key exchanges
1935 See src/ssl_support.c or OpenSSL SSL_CTX_set_options
1936 documentation for a complete list of options.
1938 clientca= File containing the list of CAs to use when
1939 requesting a client certificate.
1941 cafile= File containing additional CA certificates to
1942 use when verifying client certificates. If unset
1943 clientca will be used.
1945 capath= Directory containing additional CA certificates
1946 and CRL lists to use when verifying client certificates.
1948 crlfile= File of additional CRL lists to use when verifying
1949 the client certificate, in addition to CRLs stored in
1950 the capath. Implies VERIFY_CRL flag below.
1952 dhparams= File containing DH parameters for temporary/ephemeral
1955 sslflags= Various flags modifying the use of SSL:
1957 Don't request client certificates
1958 immediately, but wait until acl processing
1959 requires a certificate (not yet implemented).
1961 Don't use the default CA lists built in
1964 Don't allow for session reuse. Each connection
1965 will result in a new SSL session.
1967 Verify CRL lists when accepting client
1970 Verify CRL lists for all certificates in the
1971 client certificate chain.
1973 sslcontext= SSL session ID context identifier.
1975 generate-host-certificates[=<on|off>]
1976 Dynamically create SSL server certificates for the
1977 destination hosts of bumped SSL requests.When
1978 enabled, the cert and key options are used to sign
1979 generated certificates. Otherwise generated
1980 certificate will be selfsigned.
1981 If there is CA certificate life time of generated
1982 certificate equals lifetime of CA certificate. If
1983 generated certificate is selfsigned lifetime is three
1985 This option is enabled by default when SslBump is used.
1986 See the sslBump option above for more information.
1988 dynamic_cert_mem_cache_size=SIZE
1989 Approximate total RAM size spent on cached generated
1990 certificates. If set to zero, caching is disabled. The
1991 default value is 4MB.
1993 See http_port for a list of available options.
2001 Enables Native FTP proxy by specifying the socket address where Squid
2002 listens for FTP client requests. See http_port directive for various
2003 ways to specify the listening address and mode.
2005 Usage: ftp_port address [mode] [options]
2007 WARNING: This is a new, experimental, complex feature that has seen
2008 limited production exposure. Some Squid modules (e.g., caching) do not
2009 currently work with native FTP proxying, and many features have not
2010 even been tested for compatibility. Test well before deploying!
2012 Native FTP proxying differs substantially from proxying HTTP requests
2013 with ftp:// URIs because Squid works as an FTP server and receives
2014 actual FTP commands (rather than HTTP requests with FTP URLs).
2016 Native FTP commands accepted at ftp_port are internally converted or
2017 wrapped into HTTP-like messages. The same happens to Native FTP
2018 responses received from FTP origin servers. Those HTTP-like messages
2019 are shoveled through regular access control and adaptation layers
2020 between the FTP client and the FTP origin server. This allows Squid to
2021 examine, adapt, block, and log FTP exchanges. Squid reuses most HTTP
2022 mechanisms when shoveling wrapped FTP messages. For example,
2023 http_access and adaptation_access directives are used.
2027 intercept Same as http_port intercept. The FTP origin address is
2028 determined based on the intended destination of the
2029 intercepted connection.
2031 tproxy Support Linux TPROXY for spoofing outgoing
2032 connections using the client IP address.
2033 NP: disables authentication and maybe IPv6 on the port.
2035 By default (i.e., without an explicit mode option), Squid extracts the
2036 FTP origin address from the login@origin parameter of the FTP USER
2037 command. Many popular FTP clients support such native FTP proxying.
2041 name=token Specifies an internal name for the port. Defaults to
2042 the port address. Usable with myportname ACL.
2045 Enables tracking of FTP directories by injecting extra
2046 PWD commands and adjusting Request-URI (in wrapping
2047 HTTP requests) to reflect the current FTP server
2048 directory. Tracking is disabled by default.
2050 protocol=FTP Protocol to reconstruct accelerated and intercepted
2051 requests with. Defaults to FTP. No other accepted
2052 values have been tested with. An unsupported value
2053 results in a FATAL error. Accepted values are FTP,
2054 HTTP (or HTTP/1.1), and HTTPS (or HTTPS/1.1).
2056 Other http_port modes and options that are not specific to HTTP and
2057 HTTPS may also work.
2060 NAME: tcp_outgoing_tos tcp_outgoing_ds tcp_outgoing_dscp
2063 LOC: Ip::Qos::TheConfig.tosToServer
2065 Allows you to select a TOS/Diffserv value for packets outgoing
2066 on the server side, based on an ACL.
2068 tcp_outgoing_tos ds-field [!]aclname ...
2070 Example where normal_service_net uses the TOS value 0x00
2071 and good_service_net uses 0x20
2073 acl normal_service_net src 10.0.0.0/24
2074 acl good_service_net src 10.0.1.0/24
2075 tcp_outgoing_tos 0x00 normal_service_net
2076 tcp_outgoing_tos 0x20 good_service_net
2078 TOS/DSCP values really only have local significance - so you should
2079 know what you're specifying. For more information, see RFC2474,
2080 RFC2475, and RFC3260.
2082 The TOS/DSCP byte must be exactly that - a octet value 0 - 255, or
2083 "default" to use whatever default your host has. Note that in
2084 practice often only multiples of 4 is usable as the two rightmost bits
2085 have been redefined for use by ECN (RFC 3168 section 23.1).
2087 Processing proceeds in the order specified, and stops at first fully
2090 Only fast ACLs are supported.
2093 NAME: clientside_tos
2096 LOC: Ip::Qos::TheConfig.tosToClient
2098 Allows you to select a TOS/Diffserv value for packets being transmitted
2099 on the client-side, based on an ACL.
2101 clientside_tos ds-field [!]aclname ...
2103 Example where normal_service_net uses the TOS value 0x00
2104 and good_service_net uses 0x20
2106 acl normal_service_net src 10.0.0.0/24
2107 acl good_service_net src 10.0.1.0/24
2108 clientside_tos 0x00 normal_service_net
2109 clientside_tos 0x20 good_service_net
2111 Note: This feature is incompatible with qos_flows. Any TOS values set here
2112 will be overwritten by TOS values in qos_flows.
2115 NAME: tcp_outgoing_mark
2117 IFDEF: SO_MARK&&USE_LIBCAP
2119 LOC: Ip::Qos::TheConfig.nfmarkToServer
2121 Allows you to apply a Netfilter mark value to outgoing packets
2122 on the server side, based on an ACL.
2124 tcp_outgoing_mark mark-value [!]aclname ...
2126 Example where normal_service_net uses the mark value 0x00
2127 and good_service_net uses 0x20
2129 acl normal_service_net src 10.0.0.0/24
2130 acl good_service_net src 10.0.1.0/24
2131 tcp_outgoing_mark 0x00 normal_service_net
2132 tcp_outgoing_mark 0x20 good_service_net
2134 Only fast ACLs are supported.
2137 NAME: clientside_mark
2139 IFDEF: SO_MARK&&USE_LIBCAP
2141 LOC: Ip::Qos::TheConfig.nfmarkToClient
2143 Allows you to apply a Netfilter mark value to packets being transmitted
2144 on the client-side, based on an ACL.
2146 clientside_mark mark-value [!]aclname ...
2148 Example where normal_service_net uses the mark value 0x00
2149 and good_service_net uses 0x20
2151 acl normal_service_net src 10.0.0.0/24
2152 acl good_service_net src 10.0.1.0/24
2153 clientside_mark 0x00 normal_service_net
2154 clientside_mark 0x20 good_service_net
2156 Note: This feature is incompatible with qos_flows. Any mark values set here
2157 will be overwritten by mark values in qos_flows.
2164 LOC: Ip::Qos::TheConfig
2166 Allows you to select a TOS/DSCP value to mark outgoing
2167 connections to the client, based on where the reply was sourced.
2168 For platforms using netfilter, allows you to set a netfilter mark
2169 value instead of, or in addition to, a TOS value.
2171 By default this functionality is disabled. To enable it with the default
2172 settings simply use "qos_flows mark" or "qos_flows tos". Default
2173 settings will result in the netfilter mark or TOS value being copied
2174 from the upstream connection to the client. Note that it is the connection
2175 CONNMARK value not the packet MARK value that is copied.
2177 It is not currently possible to copy the mark or TOS value from the
2178 client to the upstream connection request.
2180 TOS values really only have local significance - so you should
2181 know what you're specifying. For more information, see RFC2474,
2182 RFC2475, and RFC3260.
2184 The TOS/DSCP byte must be exactly that - a octet value 0 - 255. Note that
2185 in practice often only multiples of 4 is usable as the two rightmost bits
2186 have been redefined for use by ECN (RFC 3168 section 23.1).
2188 Mark values can be any unsigned 32-bit integer value.
2190 This setting is configured by setting the following values:
2192 tos|mark Whether to set TOS or netfilter mark values
2194 local-hit=0xFF Value to mark local cache hits.
2196 sibling-hit=0xFF Value to mark hits from sibling peers.
2198 parent-hit=0xFF Value to mark hits from parent peers.
2200 miss=0xFF[/mask] Value to mark cache misses. Takes precedence
2201 over the preserve-miss feature (see below), unless
2202 mask is specified, in which case only the bits
2203 specified in the mask are written.
2205 The TOS variant of the following features are only possible on Linux
2206 and require your kernel to be patched with the TOS preserving ZPH
2207 patch, available from http://zph.bratcheda.org
2208 No patch is needed to preserve the netfilter mark, which will work
2209 with all variants of netfilter.
2211 disable-preserve-miss
2212 This option disables the preservation of the TOS or netfilter
2213 mark. By default, the existing TOS or netfilter mark value of
2214 the response coming from the remote server will be retained
2215 and masked with miss-mark.
2216 NOTE: in the case of a netfilter mark, the mark must be set on
2217 the connection (using the CONNMARK target) not on the packet
2221 Allows you to mask certain bits in the TOS or mark value
2222 received from the remote server, before copying the value to
2223 the TOS sent towards clients.
2224 Default for tos: 0xFF (TOS from server is not changed).
2225 Default for mark: 0xFFFFFFFF (mark from server is not changed).
2227 All of these features require the --enable-zph-qos compilation flag
2228 (enabled by default). Netfilter marking also requires the
2229 libnetfilter_conntrack libraries (--with-netfilter-conntrack) and
2230 libcap 2.09+ (--with-libcap).
2234 NAME: tcp_outgoing_address
2237 DEFAULT_DOC: Address selection is performed by the operating system.
2238 LOC: Config.accessList.outgoing_address
2240 Allows you to map requests to different outgoing IP addresses
2241 based on the username or source address of the user making
2244 tcp_outgoing_address ipaddr [[!]aclname] ...
2247 Forwarding clients with dedicated IPs for certain subnets.
2249 acl normal_service_net src 10.0.0.0/24
2250 acl good_service_net src 10.0.2.0/24
2252 tcp_outgoing_address 2001:db8::c001 good_service_net
2253 tcp_outgoing_address 10.1.0.2 good_service_net
2255 tcp_outgoing_address 2001:db8::beef normal_service_net
2256 tcp_outgoing_address 10.1.0.1 normal_service_net
2258 tcp_outgoing_address 2001:db8::1
2259 tcp_outgoing_address 10.1.0.3
2261 Processing proceeds in the order specified, and stops at first fully
2264 Squid will add an implicit IP version test to each line.
2265 Requests going to IPv4 websites will use the outgoing 10.1.0.* addresses.
2266 Requests going to IPv6 websites will use the outgoing 2001:db8:* addresses.
2269 NOTE: The use of this directive using client dependent ACLs is
2270 incompatible with the use of server side persistent connections. To
2271 ensure correct results it is best to set server_persistent_connections
2272 to off when using this directive in such configurations.
2274 NOTE: The use of this directive to set a local IP on outgoing TCP links
2275 is incompatible with using TPROXY to set client IP out outbound TCP links.
2276 When needing to contact peers use the no-tproxy cache_peer option and the
2277 client_dst_passthru directive re-enable normal forwarding such as this.
2281 NAME: host_verify_strict
2284 LOC: Config.onoff.hostStrictVerify
2286 Regardless of this option setting, when dealing with intercepted
2287 traffic, Squid always verifies that the destination IP address matches
2288 the Host header domain or IP (called 'authority form URL').
2290 This enforcement is performed to satisfy a MUST-level requirement in
2291 RFC 2616 section 14.23: "The Host field value MUST represent the naming
2292 authority of the origin server or gateway given by the original URL".
2295 Squid always responds with an HTTP 409 (Conflict) error
2296 page and logs a security warning if there is no match.
2298 Squid verifies that the destination IP address matches
2299 the Host header for forward-proxy and reverse-proxy traffic
2300 as well. For those traffic types, Squid also enables the
2301 following checks, comparing the corresponding Host header
2302 and Request-URI components:
2304 * The host names (domain or IP) must be identical,
2305 but valueless or missing Host header disables all checks.
2306 For the two host names to match, both must be either IP
2309 * Port numbers must be identical, but if a port is missing
2310 the scheme-default port is assumed.
2313 When set to OFF (the default):
2314 Squid allows suspicious requests to continue but logs a
2315 security warning and blocks caching of the response.
2317 * Forward-proxy traffic is not checked at all.
2319 * Reverse-proxy traffic is not checked at all.
2321 * Intercepted traffic which passes verification is handled
2322 according to client_dst_passthru.
2324 * Intercepted requests which fail verification are sent
2325 to the client original destination instead of DIRECT.
2326 This overrides 'client_dst_passthru off'.
2328 For now suspicious intercepted CONNECT requests are always
2329 responded to with an HTTP 409 (Conflict) error page.
2334 As described in CVE-2009-0801 when the Host: header alone is used
2335 to determine the destination of a request it becomes trivial for
2336 malicious scripts on remote websites to bypass browser same-origin
2337 security policy and sandboxing protections.
2339 The cause of this is that such applets are allowed to perform their
2340 own HTTP stack, in which case the same-origin policy of the browser
2341 sandbox only verifies that the applet tries to contact the same IP
2342 as from where it was loaded at the IP level. The Host: header may
2343 be different from the connected IP and approved origin.
2347 NAME: client_dst_passthru
2350 LOC: Config.onoff.client_dst_passthru
2352 With NAT or TPROXY intercepted traffic Squid may pass the request
2353 directly to the original client destination IP or seek a faster
2354 source using the HTTP Host header.
2356 Using Host to locate alternative servers can provide faster
2357 connectivity with a range of failure recovery options.
2358 But can also lead to connectivity trouble when the client and
2359 server are attempting stateful interactions unaware of the proxy.
2361 This option (on by default) prevents alternative DNS entries being
2362 located to send intercepted traffic DIRECT to an origin server.
2363 The clients original destination IP and port will be used instead.
2365 Regardless of this option setting, when dealing with intercepted
2366 traffic Squid will verify the Host: header and any traffic which
2367 fails Host verification will be treated as if this option were ON.
2369 see host_verify_strict for details on the verification process.
2374 -----------------------------------------------------------------------------
2377 NAME: ssl_unclean_shutdown
2381 LOC: Config.SSL.unclean_shutdown
2383 Some browsers (especially MSIE) bugs out on SSL shutdown
2390 LOC: Config.SSL.ssl_engine
2393 The OpenSSL engine to use. You will need to set this if you
2394 would like to use hardware SSL acceleration for example.
2397 NAME: sslproxy_client_certificate
2400 LOC: Config.ssl_client.cert
2403 Client SSL Certificate to use when proxying https:// URLs
2406 NAME: sslproxy_client_key
2409 LOC: Config.ssl_client.key
2412 Client SSL Key to use when proxying https:// URLs
2415 NAME: sslproxy_version
2418 DEFAULT_DOC: automatic SSL/TLS version negotiation
2419 LOC: Config.ssl_client.version
2422 SSL version level to use when proxying https:// URLs
2424 The versions of SSL/TLS supported:
2426 1 automatic (default)
2433 NAME: sslproxy_options
2436 LOC: Config.ssl_client.options
2439 SSL implementation options to use when proxying https:// URLs
2441 The most important being:
2443 NO_SSLv3 Disallow the use of SSLv3
2444 NO_TLSv1 Disallow the use of TLSv1.0
2445 NO_TLSv1_1 Disallow the use of TLSv1.1
2446 NO_TLSv1_2 Disallow the use of TLSv1.2
2448 Always create a new key when using temporary/ephemeral
2451 Disable use of RFC5077 session tickets. Some servers
2452 may have problems understanding the TLS extension due
2453 to ambiguous specification in RFC4507.
2454 ALL Enable various bug workarounds suggested as "harmless"
2455 by OpenSSL. Be warned that this may reduce SSL/TLS
2456 strength to some attacks.
2458 See the OpenSSL SSL_CTX_set_options documentation for a
2459 complete list of possible options.
2462 NAME: sslproxy_cipher
2465 LOC: Config.ssl_client.cipher
2468 SSL cipher list to use when proxying https:// URLs
2470 Colon separated list of supported ciphers.
2473 NAME: sslproxy_cafile
2476 LOC: Config.ssl_client.cafile
2479 file containing CA certificates to use when verifying server
2480 certificates while proxying https:// URLs
2483 NAME: sslproxy_capath
2486 LOC: Config.ssl_client.capath
2489 directory containing CA certificates to use when verifying
2490 server certificates while proxying https:// URLs
2493 NAME: sslproxy_session_ttl
2496 LOC: Config.SSL.session_ttl
2499 Sets the timeout value for SSL sessions
2502 NAME: sslproxy_session_cache_size
2505 LOC: Config.SSL.sessionCacheSize
2508 Sets the cache size to use for ssl session
2511 NAME: sslproxy_cert_sign_hash
2514 LOC: Config.SSL.certSignHash
2517 Sets the hashing algorithm to use when signing generated certificates.
2518 Valid algorithm names depend on the OpenSSL library used. The following
2519 names are usually available: sha1, sha256, sha512, and md5. Please see
2520 your OpenSSL library manual for the available hashes. By default, Squids
2521 that support this option use sha256 hashes.
2523 Squid does not forcefully purge cached certificates that were generated
2524 with an algorithm other than the currently configured one. They remain
2525 in the cache, subject to the regular cache eviction policy, and become
2526 useful if the algorithm changes again.
2531 TYPE: sslproxy_ssl_bump
2532 LOC: Config.accessList.ssl_bump
2533 DEFAULT_DOC: Become a TCP tunnel without decrypting proxied traffic.
2536 This option is consulted when a CONNECT request is received on
2537 an http_port (or a new connection is intercepted at an
2538 https_port), provided that port was configured with an ssl-bump
2539 flag. The subsequent data on the connection is either treated as
2540 HTTPS and decrypted OR tunneled at TCP level without decryption,
2541 depending on the first matching bumping "action".
2543 ssl_bump <action> [!]acl ...
2545 The following bumping actions are currently supported:
2548 Become a TCP tunnel without decrypting proxied traffic.
2549 This is the default action.
2552 Establish a secure connection with the server and, using a
2553 mimicked server certificate, with the client.
2556 Receive client (step SslBump1) or server (step SslBump2)
2557 certificate while preserving the possibility of splicing the
2558 connection. Peeking at the server certificate (during step 2)
2559 usually precludes bumping of the connection at step 3.
2562 Receive client (step SslBump1) or server (step SslBump2)
2563 certificate while preserving the possibility of bumping the
2564 connection. Staring at the server certificate (during step 2)
2565 usually precludes splicing of the connection at step 3.
2568 Close client and server connections.
2570 Backward compatibility actions available at step SslBump1:
2573 Bump the connection. Establish a secure connection with the
2574 client first, then connect to the server. This old mode does
2575 not allow Squid to mimic server SSL certificate and does not
2576 work with intercepted SSL connections.
2579 Bump the connection. Establish a secure connection with the
2580 server first, then establish a secure connection with the
2581 client, using a mimicked server certificate. Works with both
2582 CONNECT requests and intercepted SSL connections, but does
2583 not allow to make decisions based on SSL handshake info.
2586 Decide whether to bump or splice the connection based on
2587 client-to-squid and server-to-squid SSL hello messages.
2591 Same as the "splice" action.
2593 All ssl_bump rules are evaluated at each of the supported bumping
2594 steps. Rules with actions that are impossible at the current step are
2595 ignored. The first matching ssl_bump action wins and is applied at the
2596 end of the current step. If no rules match, the splice action is used.
2597 See the at_step ACL for a list of the supported SslBump steps.
2599 This clause supports both fast and slow acl types.
2600 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
2602 See also: http_port ssl-bump, https_port ssl-bump, and acl at_step.
2605 # Example: Bump all requests except those originating from
2606 # localhost or those going to example.com.
2608 acl broken_sites dstdomain .example.com
2609 ssl_bump splice localhost
2610 ssl_bump splice broken_sites
2614 NAME: sslproxy_flags
2617 LOC: Config.ssl_client.flags
2620 Various flags modifying the use of SSL while proxying https:// URLs:
2621 DONT_VERIFY_PEER Accept certificates that fail verification.
2622 For refined control, see sslproxy_cert_error.
2623 NO_DEFAULT_CA Don't use the default CA list built in
2627 NAME: sslproxy_cert_error
2630 DEFAULT_DOC: Server certificate errors terminate the transaction.
2631 LOC: Config.ssl_client.cert_error
2634 Use this ACL to bypass server certificate validation errors.
2636 For example, the following lines will bypass all validation errors
2637 when talking to servers for example.com. All other
2638 validation errors will result in ERR_SECURE_CONNECT_FAIL error.
2640 acl BrokenButTrustedServers dstdomain example.com
2641 sslproxy_cert_error allow BrokenButTrustedServers
2642 sslproxy_cert_error deny all
2644 This clause only supports fast acl types.
2645 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
2646 Using slow acl types may result in server crashes
2648 Without this option, all server certificate validation errors
2649 terminate the transaction to protect Squid and the client.
2651 SQUID_X509_V_ERR_INFINITE_VALIDATION error cannot be bypassed
2652 but should not happen unless your OpenSSL library is buggy.
2655 Bypassing validation errors is dangerous because an
2656 error usually implies that the server cannot be trusted
2657 and the connection may be insecure.
2659 See also: sslproxy_flags and DONT_VERIFY_PEER.
2662 NAME: sslproxy_cert_sign
2665 POSTSCRIPTUM: signUntrusted ssl::certUntrusted
2666 POSTSCRIPTUM: signSelf ssl::certSelfSigned
2667 POSTSCRIPTUM: signTrusted all
2668 TYPE: sslproxy_cert_sign
2669 LOC: Config.ssl_client.cert_sign
2672 sslproxy_cert_sign <signing algorithm> acl ...
2674 The following certificate signing algorithms are supported:
2677 Sign using the configured CA certificate which is usually
2678 placed in and trusted by end-user browsers. This is the
2679 default for trusted origin server certificates.
2682 Sign to guarantee an X509_V_ERR_CERT_UNTRUSTED browser error.
2683 This is the default for untrusted origin server certificates
2684 that are not self-signed (see ssl::certUntrusted).
2687 Sign using a self-signed certificate with the right CN to
2688 generate a X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT error in the
2689 browser. This is the default for self-signed origin server
2690 certificates (see ssl::certSelfSigned).
2692 This clause only supports fast acl types.
2694 When sslproxy_cert_sign acl(s) match, Squid uses the corresponding
2695 signing algorithm to generate the certificate and ignores all
2696 subsequent sslproxy_cert_sign options (the first match wins). If no
2697 acl(s) match, the default signing algorithm is determined by errors
2698 detected when obtaining and validating the origin server certificate.
2700 WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can
2701 be used with sslproxy_cert_adapt, but if and only if Squid is bumping a
2702 CONNECT request that carries a domain name. In all other cases (CONNECT
2703 to an IP address or an intercepted SSL connection), Squid cannot detect
2704 the domain mismatch at certificate generation time when
2705 bump-server-first is used.
2708 NAME: sslproxy_cert_adapt
2711 TYPE: sslproxy_cert_adapt
2712 LOC: Config.ssl_client.cert_adapt
2715 sslproxy_cert_adapt <adaptation algorithm> acl ...
2717 The following certificate adaptation algorithms are supported:
2720 Sets the "Not After" property to the "Not After" property of
2721 the CA certificate used to sign generated certificates.
2724 Sets the "Not Before" property to the "Not Before" property of
2725 the CA certificate used to sign generated certificates.
2727 setCommonName or setCommonName{CN}
2728 Sets Subject.CN property to the host name specified as a
2729 CN parameter or, if no explicit CN parameter was specified,
2730 extracted from the CONNECT request. It is a misconfiguration
2731 to use setCommonName without an explicit parameter for
2732 intercepted or tproxied SSL connections.
2734 This clause only supports fast acl types.
2736 Squid first groups sslproxy_cert_adapt options by adaptation algorithm.
2737 Within a group, when sslproxy_cert_adapt acl(s) match, Squid uses the
2738 corresponding adaptation algorithm to generate the certificate and
2739 ignores all subsequent sslproxy_cert_adapt options in that algorithm's
2740 group (i.e., the first match wins within each algorithm group). If no
2741 acl(s) match, the default mimicking action takes place.
2743 WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can
2744 be used with sslproxy_cert_adapt, but if and only if Squid is bumping a
2745 CONNECT request that carries a domain name. In all other cases (CONNECT
2746 to an IP address or an intercepted SSL connection), Squid cannot detect
2747 the domain mismatch at certificate generation time when
2748 bump-server-first is used.
2751 NAME: sslpassword_program
2754 LOC: Config.Program.ssl_password
2757 Specify a program used for entering SSL key passphrases
2758 when using encrypted SSL certificate keys. If not specified
2759 keys must either be unencrypted, or Squid started with the -N
2760 option to allow it to query interactively for the passphrase.
2762 The key file name is given as argument to the program allowing
2763 selection of the right password if you have multiple encrypted
2768 OPTIONS RELATING TO EXTERNAL SSL_CRTD
2769 -----------------------------------------------------------------------------
2772 NAME: sslcrtd_program
2775 DEFAULT: @DEFAULT_SSL_CRTD@ -s @DEFAULT_SSL_DB_DIR@ -M 4MB
2776 LOC: Ssl::TheConfig.ssl_crtd
2778 Specify the location and options of the executable for ssl_crtd process.
2779 @DEFAULT_SSL_CRTD@ program requires -s and -M parameters
2780 For more information use:
2781 @DEFAULT_SSL_CRTD@ -h
2784 NAME: sslcrtd_children
2785 TYPE: HelperChildConfig
2787 DEFAULT: 32 startup=5 idle=1
2788 LOC: Ssl::TheConfig.ssl_crtdChildren
2790 The maximum number of processes spawn to service ssl server.
2791 The maximum this may be safely set to is 32.
2793 The startup= and idle= options allow some measure of skew in your
2798 Sets the minimum number of processes to spawn when Squid
2799 starts or reconfigures. When set to zero the first request will
2800 cause spawning of the first child process to handle it.
2802 Starting too few children temporary slows Squid under load while it
2803 tries to spawn enough additional processes to cope with traffic.
2807 Sets a minimum of how many processes Squid is to try and keep available
2808 at all times. When traffic begins to rise above what the existing
2809 processes can handle this many more will be spawned up to the maximum
2810 configured. A minimum setting of 1 is required.
2814 Sets the maximum number of queued requests.
2815 If the queued requests exceed queue size for more than 3 minutes
2816 squid aborts its operation.
2817 The default value is set to 2*numberofchildren.
2819 You must have at least one ssl_crtd process.
2822 NAME: sslcrtvalidator_program
2826 LOC: Ssl::TheConfig.ssl_crt_validator
2828 Specify the location and options of the executable for ssl_crt_validator
2831 Usage: sslcrtvalidator_program [ttl=n] [cache=n] path ...
2834 ttl=n TTL in seconds for cached results. The default is 60 secs
2835 cache=n limit the result cache size. The default value is 2048
2838 NAME: sslcrtvalidator_children
2839 TYPE: HelperChildConfig
2841 DEFAULT: 32 startup=5 idle=1 concurrency=1
2842 LOC: Ssl::TheConfig.ssl_crt_validator_Children
2844 The maximum number of processes spawn to service SSL server.
2845 The maximum this may be safely set to is 32.
2847 The startup= and idle= options allow some measure of skew in your
2852 Sets the minimum number of processes to spawn when Squid
2853 starts or reconfigures. When set to zero the first request will
2854 cause spawning of the first child process to handle it.
2856 Starting too few children temporary slows Squid under load while it
2857 tries to spawn enough additional processes to cope with traffic.
2861 Sets a minimum of how many processes Squid is to try and keep available
2862 at all times. When traffic begins to rise above what the existing
2863 processes can handle this many more will be spawned up to the maximum
2864 configured. A minimum setting of 1 is required.
2868 The number of requests each certificate validator helper can handle in
2869 parallel. A value of 0 indicates the certficate validator does not
2870 support concurrency. Defaults to 1.
2872 When this directive is set to a value >= 1 then the protocol
2873 used to communicate with the helper is modified to include
2874 a request ID in front of the request/response. The request
2875 ID from the request must be echoed back with the response
2880 Sets the maximum number of queued requests.
2881 If the queued requests exceed queue size for more than 3 minutes
2882 squid aborts its operation.
2883 The default value is set to 2*numberofchildren.
2885 You must have at least one ssl_crt_validator process.
2889 OPTIONS WHICH AFFECT THE NEIGHBOR SELECTION ALGORITHM
2890 -----------------------------------------------------------------------------
2898 To specify other caches in a hierarchy, use the format:
2900 cache_peer hostname type http-port icp-port [options]
2905 # hostname type port port options
2906 # -------------------- -------- ----- ----- -----------
2907 cache_peer parent.foo.net parent 3128 3130 default
2908 cache_peer sib1.foo.net sibling 3128 3130 proxy-only
2909 cache_peer sib2.foo.net sibling 3128 3130 proxy-only
2910 cache_peer example.com parent 80 0 default
2911 cache_peer cdn.example.com sibling 3128 0
2913 type: either 'parent', 'sibling', or 'multicast'.
2915 proxy-port: The port number where the peer accept HTTP requests.
2916 For other Squid proxies this is usually 3128
2917 For web servers this is usually 80
2919 icp-port: Used for querying neighbor caches about objects.
2920 Set to 0 if the peer does not support ICP or HTCP.
2921 See ICP and HTCP options below for additional details.
2924 ==== ICP OPTIONS ====
2926 You MUST also set icp_port and icp_access explicitly when using these options.
2927 The defaults will prevent peer traffic using ICP.
2930 no-query Disable ICP queries to this neighbor.
2933 Indicates the named peer is a member of a multicast group.
2934 ICP queries will not be sent directly to the peer, but ICP
2935 replies will be accepted from it.
2937 closest-only Indicates that, for ICP_OP_MISS replies, we'll only forward
2938 CLOSEST_PARENT_MISSes and never FIRST_PARENT_MISSes.
2941 To only send ICP queries to this neighbor infrequently.
2942 This is used to keep the neighbor round trip time updated
2943 and is usually used in conjunction with weighted-round-robin.
2946 ==== HTCP OPTIONS ====
2948 You MUST also set htcp_port and htcp_access explicitly when using these options.
2949 The defaults will prevent peer traffic using HTCP.
2952 htcp Send HTCP, instead of ICP, queries to the neighbor.
2953 You probably also want to set the "icp-port" to 4827
2954 instead of 3130. This directive accepts a comma separated
2955 list of options described below.
2957 htcp=oldsquid Send HTCP to old Squid versions (2.5 or earlier).
2959 htcp=no-clr Send HTCP to the neighbor but without
2960 sending any CLR requests. This cannot be used with
2963 htcp=only-clr Send HTCP to the neighbor but ONLY CLR requests.
2964 This cannot be used with no-clr.
2967 Send HTCP to the neighbor including CLRs but only when
2968 they do not result from PURGE requests.
2971 Forward any HTCP CLR requests this proxy receives to the peer.
2974 ==== PEER SELECTION METHODS ====
2976 The default peer selection method is ICP, with the first responding peer
2977 being used as source. These options can be used for better load balancing.
2980 default This is a parent cache which can be used as a "last-resort"
2981 if a peer cannot be located by any of the peer-selection methods.
2982 If specified more than once, only the first is used.
2984 round-robin Load-Balance parents which should be used in a round-robin
2985 fashion in the absence of any ICP queries.
2986 weight=N can be used to add bias.
2988 weighted-round-robin
2989 Load-Balance parents which should be used in a round-robin
2990 fashion with the frequency of each parent being based on the
2991 round trip time. Closer parents are used more often.
2992 Usually used for background-ping parents.
2993 weight=N can be used to add bias.
2995 carp Load-Balance parents which should be used as a CARP array.
2996 The requests will be distributed among the parents based on the
2997 CARP load balancing hash function based on their weight.
2999 userhash Load-balance parents based on the client proxy_auth or ident username.
3001 sourcehash Load-balance parents based on the client source IP.
3004 To be used only for cache peers of type "multicast".
3005 ALL members of this multicast group have "sibling"
3006 relationship with it, not "parent". This is to a multicast
3007 group when the requested object would be fetched only from
3008 a "parent" cache, anyway. It's useful, e.g., when
3009 configuring a pool of redundant Squid proxies, being
3010 members of the same multicast group.
3013 ==== PEER SELECTION OPTIONS ====
3015 weight=N use to affect the selection of a peer during any weighted
3016 peer-selection mechanisms.
3017 The weight must be an integer; default is 1,
3018 larger weights are favored more.
3019 This option does not affect parent selection if a peering
3020 protocol is not in use.
3022 basetime=N Specify a base amount to be subtracted from round trip
3024 It is subtracted before division by weight in calculating
3025 which parent to fectch from. If the rtt is less than the
3026 base time the rtt is set to a minimal value.
3028 ttl=N Specify a TTL to use when sending multicast ICP queries
3030 Only useful when sending to a multicast group.
3031 Because we don't accept ICP replies from random
3032 hosts, you must configure other group members as
3033 peers with the 'multicast-responder' option.
3035 no-delay To prevent access to this neighbor from influencing the
3038 digest-url=URL Tell Squid to fetch the cache digest (if digests are
3039 enabled) for this host from the specified URL rather
3040 than the Squid default location.
3043 ==== CARP OPTIONS ====
3045 carp-key=key-specification
3046 use a different key than the full URL to hash against the peer.
3047 the key-specification is a comma-separated list of the keywords
3048 scheme, host, port, path, params
3049 Order is not important.
3051 ==== ACCELERATOR / REVERSE-PROXY OPTIONS ====
3053 originserver Causes this parent to be contacted as an origin server.
3054 Meant to be used in accelerator setups when the peer
3058 Set the Host header of requests forwarded to this peer.
3059 Useful in accelerator setups where the server (peer)
3060 expects a certain domain name but clients may request
3061 others. ie example.com or www.example.com
3063 no-digest Disable request of cache digests.
3066 Disables requesting ICMP RTT database (NetDB).
3069 ==== AUTHENTICATION OPTIONS ====
3072 If this is a personal/workgroup proxy and your parent
3073 requires proxy authentication.
3075 Note: The string can include URL escapes (i.e. %20 for
3076 spaces). This also means % must be written as %%.
3079 Send login details received from client to this peer.
3080 Both Proxy- and WWW-Authorization headers are passed
3081 without alteration to the peer.
3082 Authentication is not required by Squid for this to work.
3084 Note: This will pass any form of authentication but
3085 only Basic auth will work through a proxy unless the
3086 connection-auth options are also used.
3088 login=PASS Send login details received from client to this peer.
3089 Authentication is not required by this option.
3091 If there are no client-provided authentication headers
3092 to pass on, but username and password are available
3093 from an external ACL user= and password= result tags
3094 they may be sent instead.
3096 Note: To combine this with proxy_auth both proxies must
3097 share the same user database as HTTP only allows for
3098 a single login (one for proxy, one for origin server).
3099 Also be warned this will expose your users proxy
3100 password to the peer. USE WITH CAUTION
3103 Send the username to the upstream cache, but with a
3104 fixed password. This is meant to be used when the peer
3105 is in another administrative domain, but it is still
3106 needed to identify each user.
3107 The star can optionally be followed by some extra
3108 information which is added to the username. This can
3109 be used to identify this proxy to the peer, similar to
3110 the login=username:password option above.
3113 If this is a personal/workgroup proxy and your parent
3114 requires a secure proxy authentication.
3115 The first principal from the default keytab or defined by
3116 the environment variable KRB5_KTNAME will be used.
3118 WARNING: The connection may transmit requests from multiple
3119 clients. Negotiate often assumes end-to-end authentication
3120 and a single-client. Which is not strictly true here.
3122 login=NEGOTIATE:principal_name
3123 If this is a personal/workgroup proxy and your parent
3124 requires a secure proxy authentication.
3125 The principal principal_name from the default keytab or
3126 defined by the environment variable KRB5_KTNAME will be
3129 WARNING: The connection may transmit requests from multiple
3130 clients. Negotiate often assumes end-to-end authentication
3131 and a single-client. Which is not strictly true here.
3133 connection-auth=on|off
3134 Tell Squid that this peer does or not support Microsoft
3135 connection oriented authentication, and any such
3136 challenges received from there should be ignored.
3137 Default is auto to automatically determine the status
3141 ==== SSL / HTTPS / TLS OPTIONS ====
3143 ssl Encrypt connections to this peer with SSL/TLS.
3145 sslcert=/path/to/ssl/certificate
3146 A client SSL certificate to use when connecting to
3149 sslkey=/path/to/ssl/key
3150 The private SSL key corresponding to sslcert above.
3151 If 'sslkey' is not specified 'sslcert' is assumed to
3152 reference a combined file containing both the
3153 certificate and the key.
3155 sslversion=1|2|3|4|5|6
3156 The SSL version to use when connecting to this peer
3157 1 = automatic (default)
3164 sslcipher=... The list of valid SSL ciphers to use when connecting
3167 ssloptions=... Specify various SSL implementation options:
3169 NO_SSLv3 Disallow the use of SSLv3
3170 NO_TLSv1 Disallow the use of TLSv1.0
3171 NO_TLSv1_1 Disallow the use of TLSv1.1
3172 NO_TLSv1_2 Disallow the use of TLSv1.2
3174 Always create a new key when using
3175 temporary/ephemeral DH key exchanges
3176 ALL Enable various bug workarounds
3177 suggested as "harmless" by OpenSSL
3178 Be warned that this reduces SSL/TLS
3179 strength to some attacks.
3181 See the OpenSSL SSL_CTX_set_options documentation for a
3184 sslcafile=... A file containing additional CA certificates to use
3185 when verifying the peer certificate.
3187 sslcapath=... A directory containing additional CA certificates to
3188 use when verifying the peer certificate.
3190 sslcrlfile=... A certificate revocation list file to use when
3191 verifying the peer certificate.
3193 sslflags=... Specify various flags modifying the SSL implementation:
3196 Accept certificates even if they fail to
3199 Don't use the default CA list built in
3202 Don't verify the peer certificate
3203 matches the server name
3205 ssldomain= The peer name as advertised in it's certificate.
3206 Used for verifying the correctness of the received peer
3207 certificate. If not specified the peer hostname will be
3211 Enable the "Front-End-Https: On" header needed when
3212 using Squid as a SSL frontend in front of Microsoft OWA.
3213 See MS KB document Q307347 for details on this header.
3214 If set to auto the header will only be added if the
3215 request is forwarded as a https:// URL.
3218 ==== GENERAL OPTIONS ====
3221 A peer-specific connect timeout.
3222 Also see the peer_connect_timeout directive.
3224 connect-fail-limit=N
3225 How many times connecting to a peer must fail before
3226 it is marked as down. Standby connection failures
3227 count towards this limit. Default is 10.
3229 allow-miss Disable Squid's use of only-if-cached when forwarding
3230 requests to siblings. This is primarily useful when
3231 icp_hit_stale is used by the sibling. To extensive use
3232 of this option may result in forwarding loops, and you
3233 should avoid having two-way peerings with this option.
3234 For example to deny peer usage on requests from peer
3235 by denying cache_peer_access if the source is a peer.
3237 max-conn=N Limit the number of concurrent connections the Squid
3238 may open to this peer, including already opened idle
3239 and standby connections. There is no peer-specific
3240 connection limit by default.
3242 A peer exceeding the limit is not used for new
3243 requests unless a standby connection is available.
3245 max-conn currently works poorly with idle persistent
3246 connections: When a peer reaches its max-conn limit,
3247 and there are idle persistent connections to the peer,
3248 the peer may not be selected because the limiting code
3249 does not know whether Squid can reuse those idle
3252 standby=N Maintain a pool of N "hot standby" connections to an
3253 UP peer, available for requests when no idle
3254 persistent connection is available (or safe) to use.
3255 By default and with zero N, no such pool is maintained.
3256 N must not exceed the max-conn limit (if any).
3258 At start or after reconfiguration, Squid opens new TCP
3259 standby connections until there are N connections
3260 available and then replenishes the standby pool as
3261 opened connections are used up for requests. A used
3262 connection never goes back to the standby pool, but
3263 may go to the regular idle persistent connection pool
3264 shared by all peers and origin servers.
3266 Squid never opens multiple new standby connections
3267 concurrently. This one-at-a-time approach minimizes
3268 flooding-like effect on peers. Furthermore, just a few
3269 standby connections should be sufficient in most cases
3270 to supply most new requests with a ready-to-use
3273 Standby connections obey server_idle_pconn_timeout.
3274 For the feature to work as intended, the peer must be
3275 configured to accept and keep them open longer than
3276 the idle timeout at the connecting Squid, to minimize
3277 race conditions typical to idle used persistent
3278 connections. Default request_timeout and
3279 server_idle_pconn_timeout values ensure such a
3282 name=xxx Unique name for the peer.
3283 Required if you have multiple peers on the same host
3284 but different ports.
3285 This name can be used in cache_peer_access and similar
3286 directives to dentify the peer.
3287 Can be used by outgoing access controls through the
3290 no-tproxy Do not use the client-spoof TPROXY support when forwarding
3291 requests to this peer. Use normal address selection instead.
3292 This overrides the spoof_client_ip ACL.
3294 proxy-only objects fetched from the peer will not be stored locally.
3298 NAME: cache_peer_domain cache_host_domain
3303 Use to limit the domains for which a neighbor cache will be
3307 cache_peer_domain cache-host domain [domain ...]
3308 cache_peer_domain cache-host !domain
3310 For example, specifying
3312 cache_peer_domain parent.foo.net .edu
3314 has the effect such that UDP query packets are sent to
3315 'bigserver' only when the requested object exists on a
3316 server in the .edu domain. Prefixing the domainname
3317 with '!' means the cache will be queried for objects
3320 NOTE: * Any number of domains may be given for a cache-host,
3321 either on the same or separate lines.
3322 * When multiple domains are given for a particular
3323 cache-host, the first matched domain is applied.
3324 * Cache hosts with no domain restrictions are queried
3326 * There are no defaults.
3327 * There is also a 'cache_peer_access' tag in the ACL
3331 NAME: cache_peer_access
3336 Similar to 'cache_peer_domain' but provides more flexibility by
3340 cache_peer_access cache-host allow|deny [!]aclname ...
3342 The syntax is identical to 'http_access' and the other lists of
3343 ACL elements. See the comments for 'http_access' below, or
3344 the Squid FAQ (http://wiki.squid-cache.org/SquidFaq/SquidAcl).
3347 NAME: neighbor_type_domain
3348 TYPE: hostdomaintype
3350 DEFAULT_DOC: The peer type from cache_peer directive is used for all requests to that peer.
3353 Modify the cache_peer neighbor type when passing requests
3354 about specific domains to the peer.
3357 neighbor_type_domain neighbor parent|sibling domain domain ...
3360 cache_peer foo.example.com parent 3128 3130
3361 neighbor_type_domain foo.example.com sibling .au .de
3363 The above configuration treats all requests to foo.example.com as a
3364 parent proxy unless the request is for a .au or .de ccTLD domain name.
3367 NAME: dead_peer_timeout
3371 LOC: Config.Timeout.deadPeer
3373 This controls how long Squid waits to declare a peer cache
3374 as "dead." If there are no ICP replies received in this
3375 amount of time, Squid will declare the peer dead and not
3376 expect to receive any further ICP replies. However, it
3377 continues to send ICP queries, and will mark the peer as
3378 alive upon receipt of the first subsequent ICP reply.
3380 This timeout also affects when Squid expects to receive ICP
3381 replies from peers. If more than 'dead_peer' seconds have
3382 passed since the last ICP reply was received, Squid will not
3383 expect to receive an ICP reply on the next query. Thus, if
3384 your time between requests is greater than this timeout, you
3385 will see a lot of requests sent DIRECT to origin servers
3386 instead of to your parents.
3389 NAME: forward_max_tries
3392 LOC: Config.forward_max_tries
3394 Controls how many different forward paths Squid will try
3395 before giving up. See also forward_timeout.
3397 NOTE: connect_retries (default: none) can make each of these
3398 possible forwarding paths be tried multiple times.
3402 MEMORY CACHE OPTIONS
3403 -----------------------------------------------------------------------------
3410 LOC: Config.memMaxSize
3412 NOTE: THIS PARAMETER DOES NOT SPECIFY THE MAXIMUM PROCESS SIZE.
3413 IT ONLY PLACES A LIMIT ON HOW MUCH ADDITIONAL MEMORY SQUID WILL
3414 USE AS A MEMORY CACHE OF OBJECTS. SQUID USES MEMORY FOR OTHER
3415 THINGS AS WELL. SEE THE SQUID FAQ SECTION 8 FOR DETAILS.
3417 'cache_mem' specifies the ideal amount of memory to be used
3419 * In-Transit objects
3421 * Negative-Cached objects
3423 Data for these objects are stored in 4 KB blocks. This
3424 parameter specifies the ideal upper limit on the total size of
3425 4 KB blocks allocated. In-Transit objects take the highest
3428 In-transit objects have priority over the others. When
3429 additional space is needed for incoming data, negative-cached
3430 and hot objects will be released. In other words, the
3431 negative-cached and hot objects will fill up any unused space
3432 not needed for in-transit objects.
3434 If circumstances require, this limit will be exceeded.
3435 Specifically, if your incoming request rate requires more than
3436 'cache_mem' of memory to hold in-transit objects, Squid will
3437 exceed this limit to satisfy the new requests. When the load
3438 decreases, blocks will be freed until the high-water mark is
3439 reached. Thereafter, blocks will be used to store hot
3442 If shared memory caching is enabled, Squid does not use the shared
3443 cache space for in-transit objects, but they still consume as much
3444 local memory as they need. For more details about the shared memory
3445 cache, see memory_cache_shared.
3448 NAME: maximum_object_size_in_memory
3452 LOC: Config.Store.maxInMemObjSize
3454 Objects greater than this size will not be attempted to kept in
3455 the memory cache. This should be set high enough to keep objects
3456 accessed frequently in memory to improve performance whilst low
3457 enough to keep larger objects from hoarding cache_mem.
3460 NAME: memory_cache_shared
3463 LOC: Config.memShared
3465 DEFAULT_DOC: "on" where supported if doing memory caching with multiple SMP workers.
3467 Controls whether the memory cache is shared among SMP workers.
3469 The shared memory cache is meant to occupy cache_mem bytes and replace
3470 the non-shared memory cache, although some entities may still be
3471 cached locally by workers for now (e.g., internal and in-transit
3472 objects may be served from a local memory cache even if shared memory
3473 caching is enabled).
3475 By default, the memory cache is shared if and only if all of the
3476 following conditions are satisfied: Squid runs in SMP mode with
3477 multiple workers, cache_mem is positive, and Squid environment
3478 supports required IPC primitives (e.g., POSIX shared memory segments
3479 and GCC-style atomic operations).
3481 To avoid blocking locks, shared memory uses opportunistic algorithms
3482 that do not guarantee that every cachable entity that could have been
3483 shared among SMP workers will actually be shared.
3485 Currently, entities exceeding 32KB in size cannot be shared.
3488 NAME: memory_cache_mode
3492 DEFAULT_DOC: Keep the most recently fetched objects in memory
3494 Controls which objects to keep in the memory cache (cache_mem)
3496 always Keep most recently fetched objects in memory (default)
3498 disk Only disk cache hits are kept in memory, which means
3499 an object must first be cached on disk and then hit
3500 a second time before cached in memory.
3502 network Only objects fetched from network is kept in memory
3505 NAME: memory_replacement_policy
3507 LOC: Config.memPolicy
3510 The memory replacement policy parameter determines which
3511 objects are purged from memory when memory space is needed.
3513 See cache_replacement_policy for details on algorithms.
3518 -----------------------------------------------------------------------------
3521 NAME: cache_replacement_policy
3523 LOC: Config.replPolicy
3526 The cache replacement policy parameter determines which
3527 objects are evicted (replaced) when disk space is needed.
3529 lru : Squid's original list based LRU policy
3530 heap GDSF : Greedy-Dual Size Frequency
3531 heap LFUDA: Least Frequently Used with Dynamic Aging
3532 heap LRU : LRU policy implemented using a heap
3534 Applies to any cache_dir lines listed below this directive.
3536 The LRU policies keeps recently referenced objects.
3538 The heap GDSF policy optimizes object hit rate by keeping smaller
3539 popular objects in cache so it has a better chance of getting a
3540 hit. It achieves a lower byte hit rate than LFUDA though since
3541 it evicts larger (possibly popular) objects.
3543 The heap LFUDA policy keeps popular objects in cache regardless of
3544 their size and thus optimizes byte hit rate at the expense of
3545 hit rate since one large, popular object will prevent many
3546 smaller, slightly less popular objects from being cached.
3548 Both policies utilize a dynamic aging mechanism that prevents
3549 cache pollution that can otherwise occur with frequency-based
3550 replacement policies.
3552 NOTE: if using the LFUDA replacement policy you should increase
3553 the value of maximum_object_size above its default of 4 MB to
3554 to maximize the potential byte hit rate improvement of LFUDA.
3556 For more information about the GDSF and LFUDA cache replacement
3557 policies see http://www.hpl.hp.com/techreports/1999/HPL-1999-69.html
3558 and http://fog.hpl.external.hp.com/techreports/98/HPL-98-173.html.
3561 NAME: minimum_object_size
3565 DEFAULT_DOC: no limit
3566 LOC: Config.Store.minObjectSize
3568 Objects smaller than this size will NOT be saved on disk. The
3569 value is specified in bytes, and the default is 0 KB, which
3570 means all responses can be stored.
3573 NAME: maximum_object_size
3577 LOC: Config.Store.maxObjectSize
3579 Set the default value for max-size parameter on any cache_dir.
3580 The value is specified in bytes, and the default is 4 MB.
3582 If you wish to get a high BYTES hit ratio, you should probably
3583 increase this (one 32 MB object hit counts for 3200 10KB
3586 If you wish to increase hit ratio more than you want to
3587 save bandwidth you should leave this low.
3589 NOTE: if using the LFUDA replacement policy you should increase
3590 this value to maximize the byte hit rate improvement of LFUDA!
3591 See cache_replacement_policy for a discussion of this policy.
3597 DEFAULT_DOC: No disk cache. Store cache ojects only in memory.
3598 LOC: Config.cacheSwap
3601 cache_dir Type Directory-Name Fs-specific-data [options]
3603 You can specify multiple cache_dir lines to spread the
3604 cache among different disk partitions.
3606 Type specifies the kind of storage system to use. Only "ufs"
3607 is built by default. To enable any of the other storage systems
3608 see the --enable-storeio configure option.
3610 'Directory' is a top-level directory where cache swap
3611 files will be stored. If you want to use an entire disk
3612 for caching, this can be the mount-point directory.
3613 The directory must exist and be writable by the Squid
3614 process. Squid will NOT create this directory for you.
3616 In SMP configurations, cache_dir must not precede the workers option
3617 and should use configuration macros or conditionals to give each
3618 worker interested in disk caching a dedicated cache directory.
3621 ==== The ufs store type ====
3623 "ufs" is the old well-known Squid storage format that has always
3627 cache_dir ufs Directory-Name Mbytes L1 L2 [options]
3629 'Mbytes' is the amount of disk space (MB) to use under this
3630 directory. The default is 100 MB. Change this to suit your
3631 configuration. Do NOT put the size of your disk drive here.
3632 Instead, if you want Squid to use the entire disk drive,
3633 subtract 20% and use that value.
3635 'L1' is the number of first-level subdirectories which
3636 will be created under the 'Directory'. The default is 16.
3638 'L2' is the number of second-level subdirectories which
3639 will be created under each first-level directory. The default
3643 ==== The aufs store type ====
3645 "aufs" uses the same storage format as "ufs", utilizing
3646 POSIX-threads to avoid blocking the main Squid process on
3647 disk-I/O. This was formerly known in Squid as async-io.
3650 cache_dir aufs Directory-Name Mbytes L1 L2 [options]
3652 see argument descriptions under ufs above
3655 ==== The diskd store type ====
3657 "diskd" uses the same storage format as "ufs", utilizing a
3658 separate process to avoid blocking the main Squid process on
3662 cache_dir diskd Directory-Name Mbytes L1 L2 [options] [Q1=n] [Q2=n]
3664 see argument descriptions under ufs above
3666 Q1 specifies the number of unacknowledged I/O requests when Squid
3667 stops opening new files. If this many messages are in the queues,
3668 Squid won't open new files. Default is 64
3670 Q2 specifies the number of unacknowledged messages when Squid
3671 starts blocking. If this many messages are in the queues,
3672 Squid blocks until it receives some replies. Default is 72
3674 When Q1 < Q2 (the default), the cache directory is optimized
3675 for lower response time at the expense of a decrease in hit
3676 ratio. If Q1 > Q2, the cache directory is optimized for
3677 higher hit ratio at the expense of an increase in response
3681 ==== The rock store type ====
3684 cache_dir rock Directory-Name Mbytes [options]
3686 The Rock Store type is a database-style storage. All cached
3687 entries are stored in a "database" file, using fixed-size slots.
3688 A single entry occupies one or more slots.
3690 If possible, Squid using Rock Store creates a dedicated kid
3691 process called "disker" to avoid blocking Squid worker(s) on disk
3692 I/O. One disker kid is created for each rock cache_dir. Diskers
3693 are created only when Squid, running in daemon mode, has support
3694 for the IpcIo disk I/O module.
3696 swap-timeout=msec: Squid will not start writing a miss to or
3697 reading a hit from disk if it estimates that the swap operation
3698 will take more than the specified number of milliseconds. By
3699 default and when set to zero, disables the disk I/O time limit
3700 enforcement. Ignored when using blocking I/O module because
3701 blocking synchronous I/O does not allow Squid to estimate the
3702 expected swap wait time.
3704 max-swap-rate=swaps/sec: Artificially limits disk access using
3705 the specified I/O rate limit. Swap out requests that
3706 would cause the average I/O rate to exceed the limit are
3707 delayed. Individual swap in requests (i.e., hits or reads) are
3708 not delayed, but they do contribute to measured swap rate and
3709 since they are placed in the same FIFO queue as swap out
3710 requests, they may wait longer if max-swap-rate is smaller.
3711 This is necessary on file systems that buffer "too
3712 many" writes and then start blocking Squid and other processes
3713 while committing those writes to disk. Usually used together
3714 with swap-timeout to avoid excessive delays and queue overflows
3715 when disk demand exceeds available disk "bandwidth". By default
3716 and when set to zero, disables the disk I/O rate limit
3717 enforcement. Currently supported by IpcIo module only.
3719 slot-size=bytes: The size of a database "record" used for
3720 storing cached responses. A cached response occupies at least
3721 one slot and all database I/O is done using individual slots so
3722 increasing this parameter leads to more disk space waste while
3723 decreasing it leads to more disk I/O overheads. Should be a
3724 multiple of your operating system I/O page size. Defaults to
3725 16KBytes. A housekeeping header is stored with each slot and
3726 smaller slot-sizes will be rejected. The header is smaller than
3730 ==== COMMON OPTIONS ====
3732 no-store no new objects should be stored to this cache_dir.
3734 min-size=n the minimum object size in bytes this cache_dir
3735 will accept. It's used to restrict a cache_dir
3736 to only store large objects (e.g. AUFS) while
3737 other stores are optimized for smaller objects
3741 max-size=n the maximum object size in bytes this cache_dir
3743 The value in maximum_object_size directive sets
3744 the default unless more specific details are
3745 available (ie a small store capacity).
3747 Note: To make optimal use of the max-size limits you should order
3748 the cache_dir lines with the smallest max-size value first.
3752 # Uncomment and adjust the following to add a disk cache directory.
3753 #cache_dir ufs @DEFAULT_SWAP_DIR@ 100 16 256
3757 NAME: store_dir_select_algorithm
3759 LOC: Config.store_dir_select_algorithm
3762 How Squid selects which cache_dir to use when the response
3763 object will fit into more than one.
3765 Regardless of which algorithm is used the cache_dir min-size
3766 and max-size parameters are obeyed. As such they can affect
3767 the selection algorithm by limiting the set of considered
3774 This algorithm is suited to caches with similar cache_dir
3775 sizes and disk speeds.
3777 The disk with the least I/O pending is selected.
3778 When there are multiple disks with the same I/O load ranking
3779 the cache_dir with most available capacity is selected.
3781 When a mix of cache_dir sizes are configured the faster disks
3782 have a naturally lower I/O loading and larger disks have more
3783 capacity. So space used to store objects and data throughput
3784 may be very unbalanced towards larger disks.
3789 This algorithm is suited to caches with unequal cache_dir
3792 Each cache_dir is selected in a rotation. The next suitable
3795 Available cache_dir capacity is only considered in relation
3796 to whether the object will fit and meets the min-size and
3797 max-size parameters.
3799 Disk I/O loading is only considered to prevent overload on slow
3800 disks. This algorithm does not spread objects by size, so any
3801 I/O loading per-disk may appear very unbalanced and volatile.
3803 If several cache_dirs use similar min-size, max-size, or other
3804 limits to to reject certain responses, then do not group such
3805 cache_dir lines together, to avoid round-robin selection bias
3806 towards the first cache_dir after the group. Instead, interleave
3807 cache_dir lines from different groups. For example:
3809 store_dir_select_algorithm round-robin
3810 cache_dir rock /hdd1 ... min-size=100000
3811 cache_dir rock /ssd1 ... max-size=99999
3812 cache_dir rock /hdd2 ... min-size=100000
3813 cache_dir rock /ssd2 ... max-size=99999
3814 cache_dir rock /hdd3 ... min-size=100000
3815 cache_dir rock /ssd3 ... max-size=99999
3818 NAME: max_open_disk_fds
3820 LOC: Config.max_open_disk_fds
3822 DEFAULT_DOC: no limit
3824 To avoid having disk as the I/O bottleneck Squid can optionally
3825 bypass the on-disk cache if more than this amount of disk file
3826 descriptors are open.
3828 A value of 0 indicates no limit.
3831 NAME: cache_swap_low
3832 COMMENT: (percent, 0-100)
3835 LOC: Config.Swap.lowWaterMark
3837 The low-water mark for cache object replacement.
3838 Replacement begins when the swap (disk) usage is above the
3839 low-water mark and attempts to maintain utilization near the
3840 low-water mark. As swap utilization gets close to high-water
3841 mark object eviction becomes more aggressive. If utilization is
3842 close to the low-water mark less replacement is done each time.
3844 Defaults are 90% and 95%. If you have a large cache, 5% could be
3845 hundreds of MB. If this is the case you may wish to set these
3846 numbers closer together.
3848 See also cache_swap_high
3851 NAME: cache_swap_high
3852 COMMENT: (percent, 0-100)
3855 LOC: Config.Swap.highWaterMark
3857 The high-water mark for cache object replacement.
3858 Replacement begins when the swap (disk) usage is above the
3859 low-water mark and attempts to maintain utilization near the
3860 low-water mark. As swap utilization gets close to high-water
3861 mark object eviction becomes more aggressive. If utilization is
3862 close to the low-water mark less replacement is done each time.
3864 Defaults are 90% and 95%. If you have a large cache, 5% could be
3865 hundreds of MB. If this is the case you may wish to set these
3866 numbers closer together.
3868 See also cache_swap_low
3873 -----------------------------------------------------------------------------
3880 DEFAULT_DOC: The format definitions squid, common, combined, referrer, useragent are built in.
3884 logformat <name> <format specification>
3886 Defines an access log format.
3888 The <format specification> is a string with embedded % format codes
3890 % format codes all follow the same basic structure where all but
3891 the formatcode is optional. Output strings are automatically escaped
3892 as required according to their context and the output format
3893 modifiers are usually not needed, but can be specified if an explicit
3894 output format is desired.
3896 % ["|[|'|#] [-] [[0]width] [{argument}] formatcode
3898 " output in quoted string format
3899 [ output in squid text log format as used by log_mime_hdrs
3900 # output in URL quoted format
3905 width minimum and/or maximum field width:
3906 [width_min][.width_max]
3907 When minimum starts with 0, the field is zero-padded.
3908 String values exceeding maximum width are truncated.
3910 {arg} argument such as header name etc
3914 % a literal % character
3915 sn Unique sequence number per log line entry
3916 err_code The ID of an error response served by Squid or
3917 a similar internal error identifier.
3918 err_detail Additional err_code-dependent error information.
3919 note The annotation specified by the argument. Also
3920 logs the adaptation meta headers set by the
3921 adaptation_meta configuration parameter.
3922 If no argument given all annotations logged.
3923 The argument may include a separator to use with
3926 By default, multiple note values are separated with ","
3927 and multiple notes are separated with "\r\n".
3928 When logging named notes with %{name}note, the
3929 explicitly configured separator is used between note
3930 values. When logging all notes with %note, the
3931 explicitly configured separator is used between
3932 individual notes. There is currently no way to
3933 specify both value and notes separators when logging
3934 all notes with %note.
3936 Connection related format codes:
3938 >a Client source IP address
3940 >p Client source port
3941 >eui Client source EUI (MAC address, EUI-48 or EUI-64 identifier)
3942 >la Local IP address the client connected to
3943 >lp Local port number the client connected to
3944 >qos Client connection TOS/DSCP value set by Squid
3945 >nfmark Client connection netfilter mark set by Squid
3947 la Local listening IP address the client connection was connected to.
3948 lp Local listening port number the client connection was connected to.
3950 <a Server IP address of the last server or peer connection
3951 <A Server FQDN or peer name
3952 <p Server port number of the last server or peer connection
3953 <la Local IP address of the last server or peer connection
3954 <lp Local port number of the last server or peer connection
3955 <qos Server connection TOS/DSCP value set by Squid
3956 <nfmark Server connection netfilter mark set by Squid
3958 Time related format codes:
3960 ts Seconds since epoch
3961 tu subsecond time (milliseconds)
3962 tl Local time. Optional strftime format argument
3963 default %d/%b/%Y:%H:%M:%S %z
3964 tg GMT time. Optional strftime format argument
3965 default %d/%b/%Y:%H:%M:%S %z
3966 tr Response time (milliseconds)
3967 dt Total time spent making DNS lookups (milliseconds)
3968 tS Approximate master transaction start time in
3969 <full seconds since epoch>.<fractional seconds> format.
3970 Currently, Squid considers the master transaction
3971 started when a complete HTTP request header initiating
3972 the transaction is received from the client. This is
3973 the same value that Squid uses to calculate transaction
3974 response time when logging %tr to access.log. Currently,
3975 Squid uses millisecond resolution for %tS values,
3976 similar to the default access.log "current time" field
3979 Access Control related format codes:
3981 et Tag returned by external acl
3982 ea Log string returned by external acl
3983 un User name (any available)
3984 ul User name from authentication
3985 ue User name from external acl helper
3986 ui User name from ident
3987 us User name from SSL
3988 credentials Client credentials. The exact meaning depends on
3989 the authentication scheme: For Basic authentication,
3990 it is the password; for Digest, the realm sent by the
3991 client; for NTLM and Negotiate, the client challenge
3992 or client credentials prefixed with "YR " or "KK ".
3994 HTTP related format codes:
3998 [http::]rm Request method (GET/POST etc)
3999 [http::]>rm Request method from client
4000 [http::]<rm Request method sent to server or peer
4001 [http::]ru Request URL from client (historic, filtered for logging)
4002 [http::]>ru Request URL from client
4003 [http::]<ru Request URL sent to server or peer
4004 [http::]>rs Request URL scheme from client
4005 [http::]<rs Request URL scheme sent to server or peer
4006 [http::]>rd Request URL domain from client
4007 [http::]<rd Request URL domain sent to server or peer
4008 [http::]>rP Request URL port from client
4009 [http::]<rP Request URL port sent to server or peer
4010 [http::]rp Request URL path excluding hostname
4011 [http::]>rp Request URL path excluding hostname from client
4012 [http::]<rp Request URL path excluding hostname sent to server or peer
4013 [http::]rv Request protocol version
4014 [http::]>rv Request protocol version from client
4015 [http::]<rv Request protocol version sent to server or peer
4017 [http::]>h Original received request header.
4018 Usually differs from the request header sent by
4019 Squid, although most fields are often preserved.
4020 Accepts optional header field name/value filter
4021 argument using name[:[separator]element] format.
4022 [http::]>ha Received request header after adaptation and
4023 redirection (pre-cache REQMOD vectoring point).
4024 Usually differs from the request header sent by
4025 Squid, although most fields are often preserved.
4026 Optional header name argument as for >h
4031 [http::]<Hs HTTP status code received from the next hop
4032 [http::]>Hs HTTP status code sent to the client
4034 [http::]<h Reply header. Optional header name argument
4037 [http::]mt MIME content type
4042 [http::]st Total size of request + reply traffic with client
4043 [http::]>st Total size of request received from client.
4044 Excluding chunked encoding bytes.
4045 [http::]<st Total size of reply sent to client (after adaptation)
4047 [http::]>sh Size of request headers received from client
4048 [http::]<sh Size of reply headers sent to client (after adaptation)
4050 [http::]<sH Reply high offset sent
4051 [http::]<sS Upstream object size
4053 [http::]<bs Number of HTTP-equivalent message body bytes
4054 received from the next hop, excluding chunked
4055 transfer encoding and control messages.
4056 Generated FTP/Gopher listings are treated as
4062 [http::]<pt Peer response time in milliseconds. The timer starts
4063 when the last request byte is sent to the next hop
4064 and stops when the last response byte is received.
4065 [http::]<tt Total time in milliseconds. The timer
4066 starts with the first connect request (or write I/O)
4067 sent to the first selected peer. The timer stops
4068 with the last I/O with the last peer.
4070 Squid handling related format codes:
4072 Ss Squid request status (TCP_MISS etc)
4073 Sh Squid hierarchy status (DEFAULT_PARENT etc)
4075 SSL-related format codes:
4077 ssl::bump_mode SslBump decision for the transaction:
4079 For CONNECT requests that initiated bumping of
4080 a connection and for any request received on
4081 an already bumped connection, Squid logs the
4082 corresponding SslBump mode ("server-first" or
4083 "client-first"). See the ssl_bump option for
4084 more information about these modes.
4086 A "none" token is logged for requests that
4087 triggered "ssl_bump" ACL evaluation matching
4088 either a "none" rule or no rules at all.
4090 In all other cases, a single dash ("-") is
4093 ssl::>sni SSL client SNI sent to Squid. Available only
4094 after the peek, stare, or splice SSL bumping
4097 If ICAP is enabled, the following code becomes available (as
4098 well as ICAP log codes documented with the icap_log option):
4100 icap::tt Total ICAP processing time for the HTTP
4101 transaction. The timer ticks when ICAP
4102 ACLs are checked and when ICAP
4103 transaction is in progress.
4105 If adaptation is enabled the following three codes become available:
4107 adapt::<last_h The header of the last ICAP response or
4108 meta-information from the last eCAP
4109 transaction related to the HTTP transaction.
4110 Like <h, accepts an optional header name
4113 adapt::sum_trs Summed adaptation transaction response
4114 times recorded as a comma-separated list in
4115 the order of transaction start time. Each time
4116 value is recorded as an integer number,
4117 representing response time of one or more
4118 adaptation (ICAP or eCAP) transaction in
4119 milliseconds. When a failed transaction is
4120 being retried or repeated, its time is not
4121 logged individually but added to the
4122 replacement (next) transaction. See also:
4125 adapt::all_trs All adaptation transaction response times.
4126 Same as adaptation_strs but response times of
4127 individual transactions are never added
4128 together. Instead, all transaction response
4129 times are recorded individually.
4131 You can prefix adapt::*_trs format codes with adaptation
4132 service name in curly braces to record response time(s) specific
4133 to that service. For example: %{my_service}adapt::sum_trs
4135 If SSL is enabled, the following formating codes become available:
4137 %ssl::>cert_subject The Subject field of the received client
4138 SSL certificate or a dash ('-') if Squid has
4139 received an invalid/malformed certificate or
4140 no certificate at all. Consider encoding the
4141 logged value because Subject often has spaces.
4143 %ssl::>cert_issuer The Issuer field of the received client
4144 SSL certificate or a dash ('-') if Squid has
4145 received an invalid/malformed certificate or
4146 no certificate at all. Consider encoding the
4147 logged value because Issuer often has spaces.
4149 The default formats available (which do not need re-defining) are:
4151 logformat squid %ts.%03tu %6tr %>a %Ss/%03>Hs %<st %rm %ru %[un %Sh/%<a %mt
4152 logformat common %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st %Ss:%Sh
4153 logformat combined %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st "%{Referer}>h" "%{User-Agent}>h" %Ss:%Sh
4154 logformat referrer %ts.%03tu %>a %{Referer}>h %ru
4155 logformat useragent %>a [%tl] "%{User-Agent}>h"
4157 NOTE: When the log_mime_hdrs directive is set to ON.
4158 The squid, common and combined formats have a safely encoded copy
4159 of the mime headers appended to each line within a pair of brackets.
4161 NOTE: The common and combined formats are not quite true to the Apache definition.
4162 The logs from Squid contain an extra status and hierarchy code appended.
4166 NAME: access_log cache_access_log
4168 LOC: Config.Log.accesslogs
4169 DEFAULT_IF_NONE: daemon:@DEFAULT_ACCESS_LOG@ squid
4171 Configures whether and how Squid logs HTTP and ICP transactions.
4172 If access logging is enabled, a single line is logged for every
4173 matching HTTP or ICP request. The recommended directive formats are:
4175 access_log <module>:<place> [option ...] [acl acl ...]
4176 access_log none [acl acl ...]
4178 The following directive format is accepted but may be deprecated:
4179 access_log <module>:<place> [<logformat name> [acl acl ...]]
4181 In most cases, the first ACL name must not contain the '=' character
4182 and should not be equal to an existing logformat name. You can always
4183 start with an 'all' ACL to work around those restrictions.
4185 Will log to the specified module:place using the specified format (which
4186 must be defined in a logformat directive) those entries which match
4187 ALL the acl's specified (which must be defined in acl clauses).
4188 If no acl is specified, all requests will be logged to this destination.
4190 ===== Available options for the recommended directive format =====
4192 logformat=name Names log line format (either built-in or
4193 defined by a logformat directive). Defaults
4196 buffer-size=64KB Defines approximate buffering limit for log
4197 records (see buffered_logs). Squid should not
4198 keep more than the specified size and, hence,
4199 should flush records before the buffer becomes
4200 full to avoid overflows under normal
4201 conditions (the exact flushing algorithm is
4202 module-dependent though). The on-error option
4203 controls overflow handling.
4205 on-error=die|drop Defines action on unrecoverable errors. The
4206 'drop' action ignores (i.e., does not log)
4207 affected log records. The default 'die' action
4208 kills the affected worker. The drop action
4209 support has not been tested for modules other
4212 ===== Modules Currently available =====
4214 none Do not log any requests matching these ACL.
4215 Do not specify Place or logformat name.
4217 stdio Write each log line to disk immediately at the completion of
4219 Place: the filename and path to be written.
4221 daemon Very similar to stdio. But instead of writing to disk the log
4222 line is passed to a daemon helper for asychronous handling instead.
4223 Place: varies depending on the daemon.
4225 log_file_daemon Place: the file name and path to be written.
4227 syslog To log each request via syslog facility.
4228 Place: The syslog facility and priority level for these entries.
4229 Place Format: facility.priority
4231 where facility could be any of:
4232 authpriv, daemon, local0 ... local7 or user.
4234 And priority could be any of:
4235 err, warning, notice, info, debug.
4237 udp To send each log line as text data to a UDP receiver.
4238 Place: The destination host name or IP and port.
4239 Place Format: //host:port
4241 tcp To send each log line as text data to a TCP receiver.
4242 Lines may be accumulated before sending (see buffered_logs).
4243 Place: The destination host name or IP and port.
4244 Place Format: //host:port
4247 access_log daemon:@DEFAULT_ACCESS_LOG@ squid
4253 LOC: Config.Log.icaplogs
4256 ICAP log files record ICAP transaction summaries, one line per
4259 The icap_log option format is:
4260 icap_log <filepath> [<logformat name> [acl acl ...]]
4261 icap_log none [acl acl ...]]
4263 Please see access_log option documentation for details. The two
4264 kinds of logs share the overall configuration approach and many
4267 ICAP processing of a single HTTP message or transaction may
4268 require multiple ICAP transactions. In such cases, multiple
4269 ICAP transaction log lines will correspond to a single access
4272 ICAP log uses logformat codes that make sense for an ICAP
4273 transaction. Header-related codes are applied to the HTTP header
4274 embedded in an ICAP server response, with the following caveats:
4275 For REQMOD, there is no HTTP response header unless the ICAP
4276 server performed request satisfaction. For RESPMOD, the HTTP
4277 request header is the header sent to the ICAP server. For
4278 OPTIONS, there are no HTTP headers.
4280 The following format codes are also available for ICAP logs:
4282 icap::<A ICAP server IP address. Similar to <A.
4284 icap::<service_name ICAP service name from the icap_service
4285 option in Squid configuration file.
4287 icap::ru ICAP Request-URI. Similar to ru.
4289 icap::rm ICAP request method (REQMOD, RESPMOD, or
4290 OPTIONS). Similar to existing rm.
4292 icap::>st Bytes sent to the ICAP server (TCP payload
4293 only; i.e., what Squid writes to the socket).
4295 icap::<st Bytes received from the ICAP server (TCP
4296 payload only; i.e., what Squid reads from
4299 icap::<bs Number of message body bytes received from the
4300 ICAP server. ICAP message body, if any, usually
4301 includes encapsulated HTTP message headers and
4302 possibly encapsulated HTTP message body. The
4303 HTTP body part is dechunked before its size is
4306 icap::tr Transaction response time (in
4307 milliseconds). The timer starts when
4308 the ICAP transaction is created and
4309 stops when the transaction is completed.
4312 icap::tio Transaction I/O time (in milliseconds). The
4313 timer starts when the first ICAP request
4314 byte is scheduled for sending. The timers
4315 stops when the last byte of the ICAP response
4318 icap::to Transaction outcome: ICAP_ERR* for all
4319 transaction errors, ICAP_OPT for OPTION
4320 transactions, ICAP_ECHO for 204
4321 responses, ICAP_MOD for message
4322 modification, and ICAP_SAT for request
4323 satisfaction. Similar to Ss.
4325 icap::Hs ICAP response status code. Similar to Hs.
4327 icap::>h ICAP request header(s). Similar to >h.
4329 icap::<h ICAP response header(s). Similar to <h.
4331 The default ICAP log format, which can be used without an explicit
4332 definition, is called icap_squid:
4334 logformat icap_squid %ts.%03tu %6icap::tr %>a %icap::to/%03icap::Hs %icap::<size %icap::rm %icap::ru% %un -/%icap::<A -
4336 See also: logformat, log_icap, and %adapt::<last_h
4339 NAME: logfile_daemon
4341 DEFAULT: @DEFAULT_LOGFILED@
4342 LOC: Log::TheConfig.logfile_daemon
4344 Specify the path to the logfile-writing daemon. This daemon is
4345 used to write the access and store logs, if configured.
4347 Squid sends a number of commands to the log daemon:
4348 L<data>\n - logfile data
4353 r<n>\n - set rotate count to <n>
4354 b<n>\n - 1 = buffer output, 0 = don't buffer output
4356 No responses is expected.
4359 NAME: stats_collection
4361 LOC: Config.accessList.stats_collection
4363 DEFAULT_DOC: Allow logging for all transactions.
4364 COMMENT: allow|deny acl acl...
4366 This options allows you to control which requests gets accounted
4367 in performance counters.
4369 This clause only supports fast acl types.
4370 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4373 NAME: cache_store_log
4376 LOC: Config.Log.store
4378 Logs the activities of the storage manager. Shows which
4379 objects are ejected from the cache, and which objects are
4380 saved and for how long.
4381 There are not really utilities to analyze this data, so you can safely
4382 disable it (the default).
4384 Store log uses modular logging outputs. See access_log for the list
4385 of modules supported.
4388 cache_store_log stdio:@DEFAULT_STORE_LOG@
4389 cache_store_log daemon:@DEFAULT_STORE_LOG@
4392 NAME: cache_swap_state cache_swap_log
4394 LOC: Config.Log.swap
4396 DEFAULT_DOC: Store the journal inside its cache_dir
4398 Location for the cache "swap.state" file. This index file holds
4399 the metadata of objects saved on disk. It is used to rebuild
4400 the cache during startup. Normally this file resides in each
4401 'cache_dir' directory, but you may specify an alternate
4402 pathname here. Note you must give a full filename, not just
4403 a directory. Since this is the index for the whole object
4404 list you CANNOT periodically rotate it!
4406 If %s can be used in the file name it will be replaced with a
4407 a representation of the cache_dir name where each / is replaced
4408 with '.'. This is needed to allow adding/removing cache_dir
4409 lines when cache_swap_log is being used.
4411 If have more than one 'cache_dir', and %s is not used in the name
4412 these swap logs will have names such as:
4418 The numbered extension (which is added automatically)
4419 corresponds to the order of the 'cache_dir' lines in this
4420 configuration file. If you change the order of the 'cache_dir'
4421 lines in this file, these index files will NOT correspond to
4422 the correct 'cache_dir' entry (unless you manually rename
4423 them). We recommend you do NOT use this option. It is
4424 better to keep these index files in each 'cache_dir' directory.
4427 NAME: logfile_rotate
4430 LOC: Config.Log.rotateNumber
4432 Specifies the number of logfile rotations to make when you
4433 type 'squid -k rotate'. The default is 10, which will rotate
4434 with extensions 0 through 9. Setting logfile_rotate to 0 will
4435 disable the file name rotation, but the logfiles are still closed
4436 and re-opened. This will enable you to rename the logfiles
4437 yourself just before sending the rotate signal.
4439 Note, the 'squid -k rotate' command normally sends a USR1
4440 signal to the running squid process. In certain situations
4441 (e.g. on Linux with Async I/O), USR1 is used for other
4442 purposes, so -k rotate uses another signal. It is best to get
4443 in the habit of using 'squid -k rotate' instead of 'kill -USR1
4446 Note, from Squid-3.1 this option is only a default for cache.log,
4447 that log can be rotated separately by using debug_options.
4452 DEFAULT: @DEFAULT_MIME_TABLE@
4453 LOC: Config.mimeTablePathname
4455 Path to Squid's icon configuration file.
4457 You shouldn't need to change this, but the default file contains
4458 examples and formatting information if you do.
4464 LOC: Config.onoff.log_mime_hdrs
4467 The Cache can record both the request and the response MIME
4468 headers for each HTTP transaction. The headers are encoded
4469 safely and will appear as two bracketed fields at the end of
4470 the access log (for either the native or httpd-emulated log
4471 formats). To enable this logging set log_mime_hdrs to 'on'.
4476 DEFAULT: @DEFAULT_PID_FILE@
4477 LOC: Config.pidFilename
4479 A filename to write the process-id to. To disable, enter "none".
4482 NAME: client_netmask
4484 LOC: Config.Addrs.client_netmask
4486 DEFAULT_DOC: Log full client IP address
4488 A netmask for client addresses in logfiles and cachemgr output.
4489 Change this to protect the privacy of your cache clients.
4490 A netmask of 255.255.255.0 will log all IP's in that range with
4491 the last digit set to '0'.
4494 NAME: strip_query_terms
4496 LOC: Config.onoff.strip_query_terms
4499 By default, Squid strips query terms from requested URLs before
4500 logging. This protects your user's privacy and reduces log size.
4502 When investigating HIT/MISS or other caching behaviour you
4503 will need to disable this to see the full URL used by Squid.
4510 LOC: Config.onoff.buffered_logs
4512 Whether to write/send access_log records ASAP or accumulate them and
4513 then write/send them in larger chunks. Buffering may improve
4514 performance because it decreases the number of I/Os. However,
4515 buffering increases the delay before log records become available to
4516 the final recipient (e.g., a disk file or logging daemon) and,
4517 hence, increases the risk of log records loss.
4519 Note that even when buffered_logs are off, Squid may have to buffer
4520 records if it cannot write/send them immediately due to pending I/Os
4521 (e.g., the I/O writing the previous log record) or connectivity loss.
4523 Currently honored by 'daemon' and 'tcp' access_log modules only.
4526 NAME: netdb_filename
4528 DEFAULT: stdio:@DEFAULT_NETDB_FILE@
4529 LOC: Config.netdbFilename
4532 Where Squid stores it's netdb journal.
4533 When enabled this journal preserves netdb state between restarts.
4535 To disable, enter "none".
4539 OPTIONS FOR TROUBLESHOOTING
4540 -----------------------------------------------------------------------------
4545 DEFAULT_IF_NONE: @DEFAULT_CACHE_LOG@
4546 LOC: Debug::cache_log
4548 Squid administrative logging file.
4550 This is where general information about Squid behavior goes. You can
4551 increase the amount of data logged to this file and how often it is
4552 rotated with "debug_options"
4558 DEFAULT_DOC: Log all critical and important messages.
4559 LOC: Debug::debugOptions
4561 Logging options are set as section,level where each source file
4562 is assigned a unique section. Lower levels result in less
4563 output, Full debugging (level 9) can result in a very large
4564 log file, so be careful.
4566 The magic word "ALL" sets debugging levels for all sections.
4567 The default is to run with "ALL,1" to record important warnings.
4569 The rotate=N option can be used to keep more or less of these logs
4570 than would otherwise be kept by logfile_rotate.
4571 For most uses a single log should be enough to monitor current
4572 events affecting Squid.
4577 LOC: Config.coredump_dir
4578 DEFAULT_IF_NONE: none
4579 DEFAULT_DOC: Use the directory from where Squid was started.
4581 By default Squid leaves core files in the directory from where
4582 it was started. If you set 'coredump_dir' to a directory
4583 that exists, Squid will chdir() to that directory at startup
4584 and coredump files will be left there.
4588 # Leave coredumps in the first cache dir
4589 coredump_dir @DEFAULT_SWAP_DIR@
4595 OPTIONS FOR FTP GATEWAYING
4596 -----------------------------------------------------------------------------
4602 LOC: Config.Ftp.anon_user
4604 If you want the anonymous login password to be more informative
4605 (and enable the use of picky FTP servers), set this to something
4606 reasonable for your domain, like wwwuser@somewhere.net
4608 The reason why this is domainless by default is the
4609 request can be made on the behalf of a user in any domain,
4610 depending on how the cache is used.
4611 Some FTP server also validate the email address is valid
4612 (for example perl.com).
4618 LOC: Config.Ftp.passive
4620 If your firewall does not allow Squid to use passive
4621 connections, turn off this option.
4623 Use of ftp_epsv_all option requires this to be ON.
4629 LOC: Config.Ftp.epsv_all
4631 FTP Protocol extensions permit the use of a special "EPSV ALL" command.
4633 NATs may be able to put the connection on a "fast path" through the
4634 translator, as the EPRT command will never be used and therefore,
4635 translation of the data portion of the segments will never be needed.
4637 When a client only expects to do two-way FTP transfers this may be
4639 If squid finds that it must do a three-way FTP transfer after issuing
4640 an EPSV ALL command, the FTP session will fail.
4642 If you have any doubts about this option do not use it.
4643 Squid will nicely attempt all other connection methods.
4645 Requires ftp_passive to be ON (default) for any effect.
4651 LOC: Config.accessList.ftp_epsv
4653 FTP Protocol extensions permit the use of a special "EPSV" command.
4655 NATs may be able to put the connection on a "fast path" through the
4656 translator using EPSV, as the EPRT command will never be used
4657 and therefore, translation of the data portion of the segments
4658 will never be needed.
4660 EPSV is often required to interoperate with FTP servers on IPv6
4661 networks. On the other hand, it may break some IPv4 servers.
4663 By default, EPSV may try EPSV with any FTP server. To fine tune
4664 that decision, you may restrict EPSV to certain clients or servers
4667 ftp_epsv allow|deny al1 acl2 ...
4669 WARNING: Disabling EPSV may cause problems with external NAT and IPv6.
4671 Only fast ACLs are supported.
4672 Requires ftp_passive to be ON (default) for any effect.
4678 LOC: Config.Ftp.eprt
4680 FTP Protocol extensions permit the use of a special "EPRT" command.
4682 This extension provides a protocol neutral alternative to the
4683 IPv4-only PORT command. When supported it enables active FTP data
4684 channels over IPv6 and efficient NAT handling.
4686 Turning this OFF will prevent EPRT being attempted and will skip
4687 straight to using PORT for IPv4 servers.
4689 Some devices are known to not handle this extension correctly and
4690 may result in crashes. Devices which suport EPRT enough to fail
4691 cleanly will result in Squid attempting PORT anyway. This directive
4692 should only be disabled when EPRT results in device failures.
4694 WARNING: Doing so will convert Squid back to the old behavior with all
4695 the related problems with external NAT devices/layers and IPv4-only FTP.
4698 NAME: ftp_sanitycheck
4701 LOC: Config.Ftp.sanitycheck
4703 For security and data integrity reasons Squid by default performs
4704 sanity checks of the addresses of FTP data connections ensure the
4705 data connection is to the requested server. If you need to allow
4706 FTP connections to servers using another IP address for the data
4707 connection turn this off.
4710 NAME: ftp_telnet_protocol
4713 LOC: Config.Ftp.telnet
4715 The FTP protocol is officially defined to use the telnet protocol
4716 as transport channel for the control connection. However, many
4717 implementations are broken and does not respect this aspect of
4720 If you have trouble accessing files with ASCII code 255 in the
4721 path or similar problems involving this ASCII code you can
4722 try setting this directive to off. If that helps, report to the
4723 operator of the FTP server in question that their FTP server
4724 is broken and does not follow the FTP standard.
4728 OPTIONS FOR EXTERNAL SUPPORT PROGRAMS
4729 -----------------------------------------------------------------------------
4734 DEFAULT: @DEFAULT_DISKD@
4735 LOC: Config.Program.diskd
4737 Specify the location of the diskd executable.
4738 Note this is only useful if you have compiled in
4739 diskd as one of the store io modules.
4742 NAME: unlinkd_program
4745 DEFAULT: @DEFAULT_UNLINKD@
4746 LOC: Config.Program.unlinkd
4748 Specify the location of the executable for file deletion process.
4751 NAME: pinger_program
4753 DEFAULT: @DEFAULT_PINGER@
4754 LOC: Config.pinger.program
4757 Specify the location of the executable for the pinger process.
4763 LOC: Config.pinger.enable
4766 Control whether the pinger is active at run-time.
4767 Enables turning ICMP pinger on and off with a simple
4768 squid -k reconfigure.
4773 OPTIONS FOR URL REWRITING
4774 -----------------------------------------------------------------------------
4777 NAME: url_rewrite_program redirect_program
4779 LOC: Config.Program.redirect
4782 Specify the location of the executable URL rewriter to use.
4783 Since they can perform almost any function there isn't one included.
4785 For each requested URL, the rewriter will receive on line with the format
4787 [channel-ID <SP>] URL [<SP> extras]<NL>
4789 See url_rewrite_extras on how to send "extras" with optional values to
4791 After processing the request the helper must reply using the following format:
4793 [channel-ID <SP>] result [<SP> kv-pairs]
4795 The result code can be:
4797 OK status=30N url="..."
4798 Redirect the URL to the one supplied in 'url='.
4799 'status=' is optional and contains the status code to send
4800 the client in Squids HTTP response. It must be one of the
4801 HTTP redirect status codes: 301, 302, 303, 307, 308.
4802 When no status is given Squid will use 302.
4804 OK rewrite-url="..."
4805 Rewrite the URL to the one supplied in 'rewrite-url='.
4806 The new URL is fetched directly by Squid and returned to
4807 the client as the response to its request.
4810 When neither of url= and rewrite-url= are sent Squid does
4814 Do not change the URL.
4817 An internal error occurred in the helper, preventing
4818 a result being identified. The 'message=' key name is
4819 reserved for delivering a log message.
4822 In addition to the above kv-pairs Squid also understands the following
4823 optional kv-pairs received from URL rewriters:
4825 Associates a TAG with the client TCP connection.
4826 The TAG is treated as a regular annotation but persists across
4827 future requests on the client connection rather than just the
4828 current request. A helper may update the TAG during subsequent
4829 requests be returning a new kv-pair.
4831 When using the concurrency= option the protocol is changed by
4832 introducing a query channel tag in front of the request/response.
4833 The query channel tag is a number between 0 and concurrency-1.
4834 This value must be echoed back unchanged to Squid as the first part
4835 of the response relating to its request.
4837 WARNING: URL re-writing ability should be avoided whenever possible.
4838 Use the URL redirect form of response instead.
4840 Re-write creates a difference in the state held by the client
4841 and server. Possibly causing confusion when the server response
4842 contains snippets of its view state. Embeded URLs, response
4843 and content Location headers, etc. are not re-written by this
4846 By default, a URL rewriter is not used.
4849 NAME: url_rewrite_children redirect_children
4850 TYPE: HelperChildConfig
4851 DEFAULT: 20 startup=0 idle=1 concurrency=0
4852 LOC: Config.redirectChildren
4854 The maximum number of redirector processes to spawn. If you limit
4855 it too few Squid will have to wait for them to process a backlog of
4856 URLs, slowing it down. If you allow too many they will use RAM
4857 and other system resources noticably.
4859 The startup= and idle= options allow some measure of skew in your
4864 Sets a minimum of how many processes are to be spawned when Squid
4865 starts or reconfigures. When set to zero the first request will
4866 cause spawning of the first child process to handle it.
4868 Starting too few will cause an initial slowdown in traffic as Squid
4869 attempts to simultaneously spawn enough processes to cope.
4873 Sets a minimum of how many processes Squid is to try and keep available
4874 at all times. When traffic begins to rise above what the existing
4875 processes can handle this many more will be spawned up to the maximum
4876 configured. A minimum setting of 1 is required.
4880 The number of requests each redirector helper can handle in
4881 parallel. Defaults to 0 which indicates the redirector
4882 is a old-style single threaded redirector.
4884 When this directive is set to a value >= 1 then the protocol
4885 used to communicate with the helper is modified to include
4886 an ID in front of the request/response. The ID from the request
4887 must be echoed back with the response to that request.
4891 Sets the maximum number of queued requests.
4892 If the queued requests exceed queue size and redirector_bypass
4893 configuration option is set, then redirector is bypassed. Otherwise, if
4894 overloading persists squid may abort its operation.
4895 The default value is set to 2*numberofchildren.
4898 NAME: url_rewrite_host_header redirect_rewrites_host_header
4901 LOC: Config.onoff.redir_rewrites_host
4903 To preserve same-origin security policies in browsers and
4904 prevent Host: header forgery by redirectors Squid rewrites
4905 any Host: header in redirected requests.
4907 If you are running an accelerator this may not be a wanted
4908 effect of a redirector. This directive enables you disable
4909 Host: alteration in reverse-proxy traffic.
4911 WARNING: Entries are cached on the result of the URL rewriting
4912 process, so be careful if you have domain-virtual hosts.
4914 WARNING: Squid and other software verifies the URL and Host
4915 are matching, so be careful not to relay through other proxies
4916 or inspecting firewalls with this disabled.
4919 NAME: url_rewrite_access redirector_access
4922 DEFAULT_DOC: Allow, unless rules exist in squid.conf.
4923 LOC: Config.accessList.redirector
4925 If defined, this access list specifies which requests are
4926 sent to the redirector processes.
4928 This clause supports both fast and slow acl types.
4929 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
4932 NAME: url_rewrite_bypass redirector_bypass
4934 LOC: Config.onoff.redirector_bypass
4937 When this is 'on', a request will not go through the
4938 redirector if all the helpers are busy. If this is 'off'
4939 and the redirector queue grows too large, Squid will exit
4940 with a FATAL error and ask you to increase the number of
4941 redirectors. You should only enable this if the redirectors
4942 are not critical to your caching system. If you use
4943 redirectors for access control, and you enable this option,
4944 users may have access to pages they should not
4945 be allowed to request.
4946 This options sets default queue-size option of the url_rewrite_children
4950 NAME: url_rewrite_extras
4951 TYPE: TokenOrQuotedString
4952 LOC: Config.redirector_extras
4953 DEFAULT: "%>a/%>A %un %>rm myip=%la myport=%lp"
4955 Specifies a string to be append to request line format for the
4956 rewriter helper. "Quoted" format values may contain spaces and
4957 logformat %macros. In theory, any logformat %macro can be used.
4958 In practice, a %macro expands as a dash (-) if the helper request is
4959 sent before the required macro information is available to Squid.
4963 OPTIONS FOR STORE ID
4964 -----------------------------------------------------------------------------
4967 NAME: store_id_program storeurl_rewrite_program
4969 LOC: Config.Program.store_id
4972 Specify the location of the executable StoreID helper to use.
4973 Since they can perform almost any function there isn't one included.
4975 For each requested URL, the helper will receive one line with the format
4977 [channel-ID <SP>] URL [<SP> extras]<NL>
4980 After processing the request the helper must reply using the following format:
4982 [channel-ID <SP>] result [<SP> kv-pairs]
4984 The result code can be:
4987 Use the StoreID supplied in 'store-id='.
4990 The default is to use HTTP request URL as the store ID.
4993 An internal error occured in the helper, preventing
4994 a result being identified.
4996 In addition to the above kv-pairs Squid also understands the following
4997 optional kv-pairs received from URL rewriters:
4999 Associates a TAG with the client TCP connection.
5000 Please see url_rewrite_program related documentation for this
5003 Helper programs should be prepared to receive and possibly ignore
5004 additional whitespace-separated tokens on each input line.
5006 When using the concurrency= option the protocol is changed by
5007 introducing a query channel tag in front of the request/response.
5008 The query channel tag is a number between 0 and concurrency-1.
5009 This value must be echoed back unchanged to Squid as the first part
5010 of the response relating to its request.
5012 NOTE: when using StoreID refresh_pattern will apply to the StoreID
5013 returned from the helper and not the URL.
5015 WARNING: Wrong StoreID value returned by a careless helper may result
5016 in the wrong cached response returned to the user.
5018 By default, a StoreID helper is not used.
5021 NAME: store_id_extras
5022 TYPE: TokenOrQuotedString
5023 LOC: Config.storeId_extras
5024 DEFAULT: "%>a/%>A %un %>rm myip=%la myport=%lp"
5026 Specifies a string to be append to request line format for the
5027 StoreId helper. "Quoted" format values may contain spaces and
5028 logformat %macros. In theory, any logformat %macro can be used.
5029 In practice, a %macro expands as a dash (-) if the helper request is
5030 sent before the required macro information is available to Squid.
5033 NAME: store_id_children storeurl_rewrite_children
5034 TYPE: HelperChildConfig
5035 DEFAULT: 20 startup=0 idle=1 concurrency=0
5036 LOC: Config.storeIdChildren
5038 The maximum number of StoreID helper processes to spawn. If you limit
5039 it too few Squid will have to wait for them to process a backlog of
5040 requests, slowing it down. If you allow too many they will use RAM
5041 and other system resources noticably.
5043 The startup= and idle= options allow some measure of skew in your
5048 Sets a minimum of how many processes are to be spawned when Squid
5049 starts or reconfigures. When set to zero the first request will
5050 cause spawning of the first child process to handle it.
5052 Starting too few will cause an initial slowdown in traffic as Squid
5053 attempts to simultaneously spawn enough processes to cope.
5057 Sets a minimum of how many processes Squid is to try and keep available
5058 at all times. When traffic begins to rise above what the existing
5059 processes can handle this many more will be spawned up to the maximum
5060 configured. A minimum setting of 1 is required.
5064 The number of requests each storeID helper can handle in
5065 parallel. Defaults to 0 which indicates the helper
5066 is a old-style single threaded program.
5068 When this directive is set to a value >= 1 then the protocol
5069 used to communicate with the helper is modified to include
5070 an ID in front of the request/response. The ID from the request
5071 must be echoed back with the response to that request.
5075 Sets the maximum number of queued requests.
5076 If the queued requests exceed queue size and store_id_bypass
5077 configuration option is set, then storeID helper is bypassed. Otherwise,
5078 if overloading persists squid may abort its operation.
5079 The default value is set to 2*numberofchildren.
5082 NAME: store_id_access storeurl_rewrite_access
5085 DEFAULT_DOC: Allow, unless rules exist in squid.conf.
5086 LOC: Config.accessList.store_id
5088 If defined, this access list specifies which requests are
5089 sent to the StoreID processes. By default all requests
5092 This clause supports both fast and slow acl types.
5093 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5096 NAME: store_id_bypass storeurl_rewrite_bypass
5098 LOC: Config.onoff.store_id_bypass
5101 When this is 'on', a request will not go through the
5102 helper if all helpers are busy. If this is 'off'
5103 and the helper queue grows too large, Squid will exit
5104 with a FATAL error and ask you to increase the number of
5105 helpers. You should only enable this if the helperss
5106 are not critical to your caching system. If you use
5107 helpers for critical caching components, and you enable this
5108 option, users may not get objects from cache.
5109 This options sets default queue-size option of the store_id_children
5114 OPTIONS FOR TUNING THE CACHE
5115 -----------------------------------------------------------------------------
5118 NAME: cache no_cache
5121 DEFAULT_DOC: By default, this directive is unused and has no effect.
5122 LOC: Config.accessList.noCache
5124 Requests denied by this directive will not be served from the cache
5125 and their responses will not be stored in the cache. This directive
5126 has no effect on other transactions and on already cached responses.
5128 This clause supports both fast and slow acl types.
5129 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5131 This and the two other similar caching directives listed below are
5132 checked at different transaction processing stages, have different
5133 access to response information, affect different cache operations,
5134 and differ in slow ACLs support:
5136 * cache: Checked before Squid makes a hit/miss determination.
5137 No access to reply information!
5138 Denies both serving a hit and storing a miss.
5139 Supports both fast and slow ACLs.
5140 * send_hit: Checked after a hit was detected.
5141 Has access to reply (hit) information.
5142 Denies serving a hit only.
5143 Supports fast ACLs only.
5144 * store_miss: Checked before storing a cachable miss.
5145 Has access to reply (miss) information.
5146 Denies storing a miss only.
5147 Supports fast ACLs only.
5149 If you are not sure which of the three directives to use, apply the
5150 following decision logic:
5152 * If your ACL(s) are of slow type _and_ need response info, redesign.
5153 Squid does not support that particular combination at this time.
5155 * If your directive ACL(s) are of slow type, use "cache"; and/or
5156 * if your directive ACL(s) need no response info, use "cache".
5158 * If you do not want the response cached, use store_miss; and/or
5159 * if you do not want a hit on a cached response, use send_hit.
5165 DEFAULT_DOC: By default, this directive is unused and has no effect.
5166 LOC: Config.accessList.sendHit
5168 Responses denied by this directive will not be served from the cache
5169 (but may still be cached, see store_miss). This directive has no
5170 effect on the responses it allows and on the cached objects.
5172 Please see the "cache" directive for a summary of differences among
5173 store_miss, send_hit, and cache directives.
5175 Unlike the "cache" directive, send_hit only supports fast acl
5176 types. See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5180 # apply custom Store ID mapping to some URLs
5181 acl MapMe dstdomain .c.example.com
5182 store_id_program ...
5183 store_id_access allow MapMe
5185 # but prevent caching of special responses
5186 # such as 302 redirects that cause StoreID loops
5187 acl Ordinary http_status 200-299
5188 store_miss deny MapMe !Ordinary
5190 # and do not serve any previously stored special responses
5191 # from the cache (in case they were already cached before
5192 # the above store_miss rule was in effect).
5193 send_hit deny MapMe !Ordinary
5199 DEFAULT_DOC: By default, this directive is unused and has no effect.
5200 LOC: Config.accessList.storeMiss
5202 Responses denied by this directive will not be cached (but may still
5203 be served from the cache, see send_hit). This directive has no
5204 effect on the responses it allows and on the already cached responses.
5206 Please see the "cache" directive for a summary of differences among
5207 store_miss, send_hit, and cache directives. See the
5208 send_hit directive for a usage example.
5210 Unlike the "cache" directive, store_miss only supports fast acl
5211 types. See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5217 LOC: Config.maxStale
5220 This option puts an upper limit on how stale content Squid
5221 will serve from the cache if cache validation fails.
5222 Can be overriden by the refresh_pattern max-stale option.
5225 NAME: refresh_pattern
5226 TYPE: refreshpattern
5230 usage: refresh_pattern [-i] regex min percent max [options]
5232 By default, regular expressions are CASE-SENSITIVE. To make
5233 them case-insensitive, use the -i option.
5235 'Min' is the time (in minutes) an object without an explicit
5236 expiry time should be considered fresh. The recommended
5237 value is 0, any higher values may cause dynamic applications
5238 to be erroneously cached unless the application designer
5239 has taken the appropriate actions.
5241 'Percent' is a percentage of the objects age (time since last
5242 modification age) an object without explicit expiry time
5243 will be considered fresh.
5245 'Max' is an upper limit on how long objects without an explicit
5246 expiry time will be considered fresh.
5248 options: override-expire
5253 ignore-must-revalidate
5260 override-expire enforces min age even if the server
5261 sent an explicit expiry time (e.g., with the
5262 Expires: header or Cache-Control: max-age). Doing this
5263 VIOLATES the HTTP standard. Enabling this feature
5264 could make you liable for problems which it causes.
5266 Note: override-expire does not enforce staleness - it only extends
5267 freshness / min. If the server returns a Expires time which
5268 is longer than your max time, Squid will still consider
5269 the object fresh for that period of time.
5271 override-lastmod enforces min age even on objects
5272 that were modified recently.
5274 reload-into-ims changes a client no-cache or ``reload''
5275 request for a cached entry into a conditional request using
5276 If-Modified-Since and/or If-None-Match headers, provided the
5277 cached entry has a Last-Modified and/or a strong ETag header.
5278 Doing this VIOLATES the HTTP standard. Enabling this feature
5279 could make you liable for problems which it causes.
5281 ignore-reload ignores a client no-cache or ``reload''
5282 header. Doing this VIOLATES the HTTP standard. Enabling
5283 this feature could make you liable for problems which
5286 ignore-no-store ignores any ``Cache-control: no-store''
5287 headers received from a server. Doing this VIOLATES
5288 the HTTP standard. Enabling this feature could make you
5289 liable for problems which it causes.
5291 ignore-must-revalidate ignores any ``Cache-Control: must-revalidate``
5292 headers received from a server. Doing this VIOLATES
5293 the HTTP standard. Enabling this feature could make you
5294 liable for problems which it causes.
5296 ignore-private ignores any ``Cache-control: private''
5297 headers received from a server. Doing this VIOLATES
5298 the HTTP standard. Enabling this feature could make you
5299 liable for problems which it causes.
5301 ignore-auth caches responses to requests with authorization,
5302 as if the originserver had sent ``Cache-control: public''
5303 in the response header. Doing this VIOLATES the HTTP standard.
5304 Enabling this feature could make you liable for problems which
5307 refresh-ims causes squid to contact the origin server
5308 when a client issues an If-Modified-Since request. This
5309 ensures that the client will receive an updated version
5310 if one is available.
5312 store-stale stores responses even if they don't have explicit
5313 freshness or a validator (i.e., Last-Modified or an ETag)
5314 present, or if they're already stale. By default, Squid will
5315 not cache such responses because they usually can't be
5316 reused. Note that such responses will be stale by default.
5318 max-stale=NN provide a maximum staleness factor. Squid won't
5319 serve objects more stale than this even if it failed to
5320 validate the object. Default: use the max_stale global limit.
5322 Basically a cached object is:
5324 FRESH if expires < now, else STALE
5326 FRESH if lm-factor < percent, else STALE
5330 The refresh_pattern lines are checked in the order listed here.
5331 The first entry which matches is used. If none of the entries
5332 match the default will be used.
5334 Note, you must uncomment all the default lines if you want
5335 to change one. The default setting is only active if none is
5341 # Add any of your own refresh_pattern entries above these.
5343 refresh_pattern ^ftp: 1440 20% 10080
5344 refresh_pattern ^gopher: 1440 0% 1440
5345 refresh_pattern -i (/cgi-bin/|\?) 0 0% 0
5346 refresh_pattern . 0 20% 4320
5350 NAME: quick_abort_min
5354 LOC: Config.quickAbort.min
5357 NAME: quick_abort_max
5361 LOC: Config.quickAbort.max
5364 NAME: quick_abort_pct
5368 LOC: Config.quickAbort.pct
5370 The cache by default continues downloading aborted requests
5371 which are almost completed (less than 16 KB remaining). This
5372 may be undesirable on slow (e.g. SLIP) links and/or very busy
5373 caches. Impatient users may tie up file descriptors and
5374 bandwidth by repeatedly requesting and immediately aborting
5377 When the user aborts a request, Squid will check the
5378 quick_abort values to the amount of data transferred until
5381 If the transfer has less than 'quick_abort_min' KB remaining,
5382 it will finish the retrieval.
5384 If the transfer has more than 'quick_abort_max' KB remaining,
5385 it will abort the retrieval.
5387 If more than 'quick_abort_pct' of the transfer has completed,
5388 it will finish the retrieval.
5390 If you do not want any retrieval to continue after the client
5391 has aborted, set both 'quick_abort_min' and 'quick_abort_max'
5394 If you want retrievals to always continue if they are being
5395 cached set 'quick_abort_min' to '-1 KB'.
5398 NAME: read_ahead_gap
5399 COMMENT: buffer-size
5401 LOC: Config.readAheadGap
5404 The amount of data the cache will buffer ahead of what has been
5405 sent to the client when retrieving an object from another server.
5409 IFDEF: USE_HTTP_VIOLATIONS
5412 LOC: Config.negativeTtl
5415 Set the Default Time-to-Live (TTL) for failed requests.
5416 Certain types of failures (such as "connection refused" and
5417 "404 Not Found") are able to be negatively-cached for a short time.
5418 Modern web servers should provide Expires: header, however if they
5419 do not this can provide a minimum TTL.
5420 The default is not to cache errors with unknown expiry details.
5422 Note that this is different from negative caching of DNS lookups.
5424 WARNING: Doing this VIOLATES the HTTP standard. Enabling
5425 this feature could make you liable for problems which it
5429 NAME: positive_dns_ttl
5432 LOC: Config.positiveDnsTtl
5435 Upper limit on how long Squid will cache positive DNS responses.
5436 Default is 6 hours (360 minutes). This directive must be set
5437 larger than negative_dns_ttl.
5440 NAME: negative_dns_ttl
5443 LOC: Config.negativeDnsTtl
5446 Time-to-Live (TTL) for negative caching of failed DNS lookups.
5447 This also sets the lower cache limit on positive lookups.
5448 Minimum value is 1 second, and it is not recommendable to go
5449 much below 10 seconds.
5452 NAME: range_offset_limit
5453 COMMENT: size [acl acl...]
5455 LOC: Config.rangeOffsetLimit
5458 usage: (size) [units] [[!]aclname]
5460 Sets an upper limit on how far (number of bytes) into the file
5461 a Range request may be to cause Squid to prefetch the whole file.
5462 If beyond this limit, Squid forwards the Range request as it is and
5463 the result is NOT cached.
5465 This is to stop a far ahead range request (lets say start at 17MB)
5466 from making Squid fetch the whole object up to that point before
5467 sending anything to the client.
5469 Multiple range_offset_limit lines may be specified, and they will
5470 be searched from top to bottom on each request until a match is found.
5471 The first match found will be used. If no line matches a request, the
5472 default limit of 0 bytes will be used.
5474 'size' is the limit specified as a number of units.
5476 'units' specifies whether to use bytes, KB, MB, etc.
5477 If no units are specified bytes are assumed.
5479 A size of 0 causes Squid to never fetch more than the
5480 client requested. (default)
5482 A size of 'none' causes Squid to always fetch the object from the
5483 beginning so it may cache the result. (2.0 style)
5485 'aclname' is the name of a defined ACL.
5487 NP: Using 'none' as the byte value here will override any quick_abort settings
5488 that may otherwise apply to the range request. The range request will
5489 be fully fetched from start to finish regardless of the client
5490 actions. This affects bandwidth usage.
5493 NAME: minimum_expiry_time
5496 LOC: Config.minimum_expiry_time
5499 The minimum caching time according to (Expires - Date)
5500 headers Squid honors if the object can't be revalidated.
5501 The default is 60 seconds.
5503 In reverse proxy environments it might be desirable to honor
5504 shorter object lifetimes. It is most likely better to make
5505 your server return a meaningful Last-Modified header however.
5507 In ESI environments where page fragments often have short
5508 lifetimes, this will often be best set to 0.
5511 NAME: store_avg_object_size
5515 LOC: Config.Store.avgObjectSize
5517 Average object size, used to estimate number of objects your
5518 cache can hold. The default is 13 KB.
5520 This is used to pre-seed the cache index memory allocation to
5521 reduce expensive reallocate operations while handling clients
5522 traffic. Too-large values may result in memory allocation during
5523 peak traffic, too-small values will result in wasted memory.
5525 Check the cache manager 'info' report metrics for the real
5526 object sizes seen by your Squid before tuning this.
5529 NAME: store_objects_per_bucket
5532 LOC: Config.Store.objectsPerBucket
5534 Target number of objects per bucket in the store hash table.
5535 Lowering this value increases the total number of buckets and
5536 also the storage maintenance rate. The default is 20.
5541 -----------------------------------------------------------------------------
5544 NAME: request_header_max_size
5548 LOC: Config.maxRequestHeaderSize
5550 This specifies the maximum size for HTTP headers in a request.
5551 Request headers are usually relatively small (about 512 bytes).
5552 Placing a limit on the request header size will catch certain
5553 bugs (for example with persistent connections) and possibly
5554 buffer-overflow or denial-of-service attacks.
5557 NAME: reply_header_max_size
5561 LOC: Config.maxReplyHeaderSize
5563 This specifies the maximum size for HTTP headers in a reply.
5564 Reply headers are usually relatively small (about 512 bytes).
5565 Placing a limit on the reply header size will catch certain
5566 bugs (for example with persistent connections) and possibly
5567 buffer-overflow or denial-of-service attacks.
5570 NAME: request_body_max_size
5574 DEFAULT_DOC: No limit.
5575 LOC: Config.maxRequestBodySize
5577 This specifies the maximum size for an HTTP request body.
5578 In other words, the maximum size of a PUT/POST request.
5579 A user who attempts to send a request with a body larger
5580 than this limit receives an "Invalid Request" error message.
5581 If you set this parameter to a zero (the default), there will
5582 be no limit imposed.
5584 See also client_request_buffer_max_size for an alternative
5585 limitation on client uploads which can be configured.
5588 NAME: client_request_buffer_max_size
5592 LOC: Config.maxRequestBufferSize
5594 This specifies the maximum buffer size of a client request.
5595 It prevents squid eating too much memory when somebody uploads
5599 NAME: chunked_request_body_max_size
5603 LOC: Config.maxChunkedRequestBodySize
5605 A broken or confused HTTP/1.1 client may send a chunked HTTP
5606 request to Squid. Squid does not have full support for that
5607 feature yet. To cope with such requests, Squid buffers the
5608 entire request and then dechunks request body to create a
5609 plain HTTP/1.0 request with a known content length. The plain
5610 request is then used by the rest of Squid code as usual.
5612 The option value specifies the maximum size of the buffer used
5613 to hold the request before the conversion. If the chunked
5614 request size exceeds the specified limit, the conversion
5615 fails, and the client receives an "unsupported request" error,
5616 as if dechunking was disabled.
5618 Dechunking is enabled by default. To disable conversion of
5619 chunked requests, set the maximum to zero.
5621 Request dechunking feature and this option in particular are a
5622 temporary hack. When chunking requests and responses are fully
5623 supported, there will be no need to buffer a chunked request.
5627 IFDEF: USE_HTTP_VIOLATIONS
5630 DEFAULT_DOC: Obey RFC 2616.
5631 LOC: Config.accessList.brokenPosts
5633 A list of ACL elements which, if matched, causes Squid to send
5634 an extra CRLF pair after the body of a PUT/POST request.
5636 Some HTTP servers has broken implementations of PUT/POST,
5637 and rely on an extra CRLF pair sent by some WWW clients.
5639 Quote from RFC2616 section 4.1 on this matter:
5641 Note: certain buggy HTTP/1.0 client implementations generate an
5642 extra CRLF's after a POST request. To restate what is explicitly
5643 forbidden by the BNF, an HTTP/1.1 client must not preface or follow
5644 a request with an extra CRLF.
5646 This clause only supports fast acl types.
5647 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
5650 acl buggy_server url_regex ^http://....
5651 broken_posts allow buggy_server
5654 NAME: adaptation_uses_indirect_client icap_uses_indirect_client
5657 IFDEF: FOLLOW_X_FORWARDED_FOR&&USE_ADAPTATION
5659 LOC: Adaptation::Config::use_indirect_client
5661 Controls whether the indirect client IP address (instead of the direct
5662 client IP address) is passed to adaptation services.
5664 See also: follow_x_forwarded_for adaptation_send_client_ip
5668 IFDEF: USE_HTTP_VIOLATIONS
5672 LOC: Config.onoff.via
5674 If set (default), Squid will include a Via header in requests and
5675 replies as required by RFC2616.
5681 LOC: Config.onoff.ie_refresh
5684 Microsoft Internet Explorer up until version 5.5 Service
5685 Pack 1 has an issue with transparent proxies, wherein it
5686 is impossible to force a refresh. Turning this on provides
5687 a partial fix to the problem, by causing all IMS-REFRESH
5688 requests from older IE versions to check the origin server
5689 for fresh content. This reduces hit ratio by some amount
5690 (~10% in my experience), but allows users to actually get
5691 fresh content when they want it. Note because Squid
5692 cannot tell if the user is using 5.5 or 5.5SP1, the behavior
5693 of 5.5 is unchanged from old versions of Squid (i.e. a
5694 forced refresh is impossible). Newer versions of IE will,
5695 hopefully, continue to have the new behavior and will be
5696 handled based on that assumption. This option defaults to
5697 the old Squid behavior, which is better for hit ratios but
5698 worse for clients using IE, if they need to be able to
5699 force fresh content.
5702 NAME: vary_ignore_expire
5705 LOC: Config.onoff.vary_ignore_expire
5708 Many HTTP servers supporting Vary gives such objects
5709 immediate expiry time with no cache-control header
5710 when requested by a HTTP/1.0 client. This option
5711 enables Squid to ignore such expiry times until
5712 HTTP/1.1 is fully implemented.
5714 WARNING: If turned on this may eventually cause some
5715 varying objects not intended for caching to get cached.
5718 NAME: request_entities
5720 LOC: Config.onoff.request_entities
5723 Squid defaults to deny GET and HEAD requests with request entities,
5724 as the meaning of such requests are undefined in the HTTP standard
5725 even if not explicitly forbidden.
5727 Set this directive to on if you have clients which insists
5728 on sending request entities in GET or HEAD requests. But be warned
5729 that there is server software (both proxies and web servers) which
5730 can fail to properly process this kind of request which may make you
5731 vulnerable to cache pollution attacks if enabled.
5734 NAME: request_header_access
5735 IFDEF: USE_HTTP_VIOLATIONS
5736 TYPE: http_header_access
5737 LOC: Config.request_header_access
5739 DEFAULT_DOC: No limits.
5741 Usage: request_header_access header_name allow|deny [!]aclname ...
5743 WARNING: Doing this VIOLATES the HTTP standard. Enabling
5744 this feature could make you liable for problems which it
5747 This option replaces the old 'anonymize_headers' and the
5748 older 'http_anonymizer' option with something that is much
5749 more configurable. A list of ACLs for each header name allows
5750 removal of specific header fields under specific conditions.
5752 This option only applies to outgoing HTTP request headers (i.e.,
5753 headers sent by Squid to the next HTTP hop such as a cache peer
5754 or an origin server). The option has no effect during cache hit
5755 detection. The equivalent adaptation vectoring point in ICAP
5756 terminology is post-cache REQMOD.
5758 The option is applied to individual outgoing request header
5759 fields. For each request header field F, Squid uses the first
5760 qualifying sets of request_header_access rules:
5762 1. Rules with header_name equal to F's name.
5763 2. Rules with header_name 'Other', provided F's name is not
5764 on the hard-coded list of commonly used HTTP header names.
5765 3. Rules with header_name 'All'.
5767 Within that qualifying rule set, rule ACLs are checked as usual.
5768 If ACLs of an "allow" rule match, the header field is allowed to
5769 go through as is. If ACLs of a "deny" rule match, the header is
5770 removed and request_header_replace is then checked to identify
5771 if the removed header has a replacement. If no rules within the
5772 set have matching ACLs, the header field is left as is.
5774 For example, to achieve the same behavior as the old
5775 'http_anonymizer standard' option, you should use:
5777 request_header_access From deny all
5778 request_header_access Referer deny all
5779 request_header_access User-Agent deny all
5781 Or, to reproduce the old 'http_anonymizer paranoid' feature
5784 request_header_access Authorization allow all
5785 request_header_access Proxy-Authorization allow all
5786 request_header_access Cache-Control allow all
5787 request_header_access Content-Length allow all
5788 request_header_access Content-Type allow all
5789 request_header_access Date allow all
5790 request_header_access Host allow all
5791 request_header_access If-Modified-Since allow all
5792 request_header_access Pragma allow all
5793 request_header_access Accept allow all
5794 request_header_access Accept-Charset allow all
5795 request_header_access Accept-Encoding allow all
5796 request_header_access Accept-Language allow all
5797 request_header_access Connection allow all
5798 request_header_access All deny all
5800 HTTP reply headers are controlled with the reply_header_access directive.
5802 By default, all headers are allowed (no anonymizing is performed).
5805 NAME: reply_header_access
5806 IFDEF: USE_HTTP_VIOLATIONS
5807 TYPE: http_header_access
5808 LOC: Config.reply_header_access
5810 DEFAULT_DOC: No limits.
5812 Usage: reply_header_access header_name allow|deny [!]aclname ...
5814 WARNING: Doing this VIOLATES the HTTP standard. Enabling
5815 this feature could make you liable for problems which it
5818 This option only applies to reply headers, i.e., from the
5819 server to the client.
5821 This is the same as request_header_access, but in the other
5822 direction. Please see request_header_access for detailed
5825 For example, to achieve the same behavior as the old
5826 'http_anonymizer standard' option, you should use:
5828 reply_header_access Server deny all
5829 reply_header_access WWW-Authenticate deny all
5830 reply_header_access Link deny all
5832 Or, to reproduce the old 'http_anonymizer paranoid' feature
5835 reply_header_access Allow allow all
5836 reply_header_access WWW-Authenticate allow all
5837 reply_header_access Proxy-Authenticate allow all
5838 reply_header_access Cache-Control allow all
5839 reply_header_access Content-Encoding allow all
5840 reply_header_access Content-Length allow all
5841 reply_header_access Content-Type allow all
5842 reply_header_access Date allow all
5843 reply_header_access Expires allow all
5844 reply_header_access Last-Modified allow all
5845 reply_header_access Location allow all
5846 reply_header_access Pragma allow all
5847 reply_header_access Content-Language allow all
5848 reply_header_access Retry-After allow all
5849 reply_header_access Title allow all
5850 reply_header_access Content-Disposition allow all
5851 reply_header_access Connection allow all
5852 reply_header_access All deny all
5854 HTTP request headers are controlled with the request_header_access directive.
5856 By default, all headers are allowed (no anonymizing is
5860 NAME: request_header_replace header_replace
5861 IFDEF: USE_HTTP_VIOLATIONS
5862 TYPE: http_header_replace
5863 LOC: Config.request_header_access
5866 Usage: request_header_replace header_name message
5867 Example: request_header_replace User-Agent Nutscrape/1.0 (CP/M; 8-bit)
5869 This option allows you to change the contents of headers
5870 denied with request_header_access above, by replacing them
5871 with some fixed string.
5873 This only applies to request headers, not reply headers.
5875 By default, headers are removed if denied.
5878 NAME: reply_header_replace
5879 IFDEF: USE_HTTP_VIOLATIONS
5880 TYPE: http_header_replace
5881 LOC: Config.reply_header_access
5884 Usage: reply_header_replace header_name message
5885 Example: reply_header_replace Server Foo/1.0
5887 This option allows you to change the contents of headers
5888 denied with reply_header_access above, by replacing them
5889 with some fixed string.
5891 This only applies to reply headers, not request headers.
5893 By default, headers are removed if denied.
5896 NAME: request_header_add
5897 TYPE: HeaderWithAclList
5898 LOC: Config.request_header_add
5901 Usage: request_header_add field-name field-value acl1 [acl2] ...
5902 Example: request_header_add X-Client-CA "CA=%ssl::>cert_issuer" all
5904 This option adds header fields to outgoing HTTP requests (i.e.,
5905 request headers sent by Squid to the next HTTP hop such as a
5906 cache peer or an origin server). The option has no effect during
5907 cache hit detection. The equivalent adaptation vectoring point
5908 in ICAP terminology is post-cache REQMOD.
5910 Field-name is a token specifying an HTTP header name. If a
5911 standard HTTP header name is used, Squid does not check whether
5912 the new header conflicts with any existing headers or violates
5913 HTTP rules. If the request to be modified already contains a
5914 field with the same name, the old field is preserved but the
5915 header field values are not merged.
5917 Field-value is either a token or a quoted string. If quoted
5918 string format is used, then the surrounding quotes are removed
5919 while escape sequences and %macros are processed.
5921 In theory, all of the logformat codes can be used as %macros.
5922 However, unlike logging (which happens at the very end of
5923 transaction lifetime), the transaction may not yet have enough
5924 information to expand a macro when the new header value is needed.
5925 And some information may already be available to Squid but not yet
5926 committed where the macro expansion code can access it (report
5927 such instances!). The macro will be expanded into a single dash
5928 ('-') in such cases. Not all macros have been tested.
5930 One or more Squid ACLs may be specified to restrict header
5931 injection to matching requests. As always in squid.conf, all
5932 ACLs in an option ACL list must be satisfied for the insertion
5933 to happen. The request_header_add option supports fast ACLs
5942 This option used to log custom information about the master
5943 transaction. For example, an admin may configure Squid to log
5944 which "user group" the transaction belongs to, where "user group"
5945 will be determined based on a set of ACLs and not [just]
5946 authentication information.
5947 Values of key/value pairs can be logged using %{key}note macros:
5949 note key value acl ...
5950 logformat myFormat ... %{key}note ...
5953 NAME: relaxed_header_parser
5954 COMMENT: on|off|warn
5956 LOC: Config.onoff.relaxed_header_parser
5959 In the default "on" setting Squid accepts certain forms
5960 of non-compliant HTTP messages where it is unambiguous
5961 what the sending application intended even if the message
5962 is not correctly formatted. The messages is then normalized
5963 to the correct form when forwarded by Squid.
5965 If set to "warn" then a warning will be emitted in cache.log
5966 each time such HTTP error is encountered.
5968 If set to "off" then such HTTP errors will cause the request
5969 or response to be rejected.
5972 NAME: collapsed_forwarding
5975 LOC: Config.onoff.collapsed_forwarding
5978 This option controls whether Squid is allowed to merge multiple
5979 potentially cachable requests for the same URI before Squid knows
5980 whether the response is going to be cachable.
5982 This feature is disabled by default: Enabling collapsed forwarding
5983 needlessly delays forwarding requests that look cachable (when they are
5984 collapsed) but then need to be forwarded individually anyway because
5985 they end up being for uncachable content. However, in some cases, such
5986 as accelleration of highly cachable content with periodic or groupped
5987 expiration times, the gains from collapsing [large volumes of
5988 simultenous refresh requests] outweigh losses from such delays.
5993 -----------------------------------------------------------------------------
5996 NAME: forward_timeout
5999 LOC: Config.Timeout.forward
6002 This parameter specifies how long Squid should at most attempt in
6003 finding a forwarding path for the request before giving up.
6006 NAME: connect_timeout
6009 LOC: Config.Timeout.connect
6012 This parameter specifies how long to wait for the TCP connect to
6013 the requested server or peer to complete before Squid should
6014 attempt to find another path where to forward the request.
6017 NAME: peer_connect_timeout
6020 LOC: Config.Timeout.peer_connect
6023 This parameter specifies how long to wait for a pending TCP
6024 connection to a peer cache. The default is 30 seconds. You
6025 may also set different timeout values for individual neighbors
6026 with the 'connect-timeout' option on a 'cache_peer' line.
6032 LOC: Config.Timeout.read
6035 Applied on peer server connections.
6037 After each successful read(), the timeout will be extended by this
6038 amount. If no data is read again after this amount of time,
6039 the request is aborted and logged with ERR_READ_TIMEOUT.
6041 The default is 15 minutes.
6047 LOC: Config.Timeout.write
6050 This timeout is tracked for all connections that have data
6051 available for writing and are waiting for the socket to become
6052 ready. After each successful write, the timeout is extended by
6053 the configured amount. If Squid has data to write but the
6054 connection is not ready for the configured duration, the
6055 transaction associated with the connection is terminated. The
6056 default is 15 minutes.
6059 NAME: request_timeout
6061 LOC: Config.Timeout.request
6064 How long to wait for complete HTTP request headers after initial
6065 connection establishment.
6068 NAME: client_idle_pconn_timeout persistent_request_timeout
6070 LOC: Config.Timeout.clientIdlePconn
6073 How long to wait for the next HTTP request on a persistent
6074 client connection after the previous request completes.
6077 NAME: ftp_client_idle_timeout
6079 LOC: Config.Timeout.ftpClientIdle
6082 How long to wait for an FTP request on a connection to Squid ftp_port.
6083 Many FTP clients do not deal with idle connection closures well,
6084 necessitating a longer default timeout than client_idle_pconn_timeout
6085 used for incoming HTTP requests.
6088 NAME: client_lifetime
6091 LOC: Config.Timeout.lifetime
6094 The maximum amount of time a client (browser) is allowed to
6095 remain connected to the cache process. This protects the Cache
6096 from having a lot of sockets (and hence file descriptors) tied up
6097 in a CLOSE_WAIT state from remote clients that go away without
6098 properly shutting down (either because of a network failure or
6099 because of a poor client implementation). The default is one
6102 NOTE: The default value is intended to be much larger than any
6103 client would ever need to be connected to your cache. You
6104 should probably change client_lifetime only as a last resort.
6105 If you seem to have many client connections tying up
6106 filedescriptors, we recommend first tuning the read_timeout,
6107 request_timeout, persistent_request_timeout and quick_abort values.
6110 NAME: half_closed_clients
6112 LOC: Config.onoff.half_closed_clients
6115 Some clients may shutdown the sending side of their TCP
6116 connections, while leaving their receiving sides open. Sometimes,
6117 Squid can not tell the difference between a half-closed and a
6118 fully-closed TCP connection.
6120 By default, Squid will immediately close client connections when
6121 read(2) returns "no more data to read."
6123 Change this option to 'on' and Squid will keep open connections
6124 until a read(2) or write(2) on the socket returns an error.
6125 This may show some benefits for reverse proxies. But if not
6126 it is recommended to leave OFF.
6129 NAME: server_idle_pconn_timeout pconn_timeout
6131 LOC: Config.Timeout.serverIdlePconn
6134 Timeout for idle persistent connections to servers and other
6141 LOC: Ident::TheConfig.timeout
6144 Maximum time to wait for IDENT lookups to complete.
6146 If this is too high, and you enabled IDENT lookups from untrusted
6147 users, you might be susceptible to denial-of-service by having
6148 many ident requests going at once.
6151 NAME: shutdown_lifetime
6154 LOC: Config.shutdownLifetime
6157 When SIGTERM or SIGHUP is received, the cache is put into
6158 "shutdown pending" mode until all active sockets are closed.
6159 This value is the lifetime to set for all open descriptors
6160 during shutdown mode. Any active clients after this many
6161 seconds will receive a 'timeout' message.
6165 ADMINISTRATIVE PARAMETERS
6166 -----------------------------------------------------------------------------
6172 LOC: Config.adminEmail
6174 Email-address of local cache manager who will receive
6175 mail if the cache dies. The default is "webmaster".
6181 LOC: Config.EmailFrom
6183 From: email-address for mail sent when the cache dies.
6184 The default is to use 'squid@unique_hostname'.
6186 See also: unique_hostname directive.
6192 LOC: Config.EmailProgram
6194 Email program used to send mail if the cache dies.
6195 The default is "mail". The specified program must comply
6196 with the standard Unix mail syntax:
6197 mail-program recipient < mailfile
6199 Optional command line options can be specified.
6202 NAME: cache_effective_user
6204 DEFAULT: @DEFAULT_CACHE_EFFECTIVE_USER@
6205 LOC: Config.effectiveUser
6207 If you start Squid as root, it will change its effective/real
6208 UID/GID to the user specified below. The default is to change
6209 to UID of @DEFAULT_CACHE_EFFECTIVE_USER@.
6210 see also; cache_effective_group
6213 NAME: cache_effective_group
6216 DEFAULT_DOC: Use system group memberships of the cache_effective_user account
6217 LOC: Config.effectiveGroup
6219 Squid sets the GID to the effective user's default group ID
6220 (taken from the password file) and supplementary group list
6221 from the groups membership.
6223 If you want Squid to run with a specific GID regardless of
6224 the group memberships of the effective user then set this
6225 to the group (or GID) you want Squid to run as. When set
6226 all other group privileges of the effective user are ignored
6227 and only this GID is effective. If Squid is not started as
6228 root the user starting Squid MUST be member of the specified
6231 This option is not recommended by the Squid Team.
6232 Our preference is for administrators to configure a secure
6233 user account for squid with UID/GID matching system policies.
6236 NAME: httpd_suppress_version_string
6240 LOC: Config.onoff.httpd_suppress_version_string
6242 Suppress Squid version string info in HTTP headers and HTML error pages.
6245 NAME: visible_hostname
6247 LOC: Config.visibleHostname
6249 DEFAULT_DOC: Automatically detect the system host name
6251 If you want to present a special hostname in error messages, etc,
6252 define this. Otherwise, the return value of gethostname()
6253 will be used. If you have multiple caches in a cluster and
6254 get errors about IP-forwarding you must set them to have individual
6255 names with this setting.
6258 NAME: unique_hostname
6260 LOC: Config.uniqueHostname
6262 DEFAULT_DOC: Copy the value from visible_hostname
6264 If you want to have multiple machines with the same
6265 'visible_hostname' you must give each machine a different
6266 'unique_hostname' so forwarding loops can be detected.
6269 NAME: hostname_aliases
6271 LOC: Config.hostnameAliases
6274 A list of other DNS names your cache has.
6282 Minimum umask which should be enforced while the proxy
6283 is running, in addition to the umask set at startup.
6285 For a traditional octal representation of umasks, start
6290 OPTIONS FOR THE CACHE REGISTRATION SERVICE
6291 -----------------------------------------------------------------------------
6293 This section contains parameters for the (optional) cache
6294 announcement service. This service is provided to help
6295 cache administrators locate one another in order to join or
6296 create cache hierarchies.
6298 An 'announcement' message is sent (via UDP) to the registration
6299 service by Squid. By default, the announcement message is NOT
6300 SENT unless you enable it with 'announce_period' below.
6302 The announcement message includes your hostname, plus the
6303 following information from this configuration file:
6309 All current information is processed regularly and made
6310 available on the Web at http://www.ircache.net/Cache/Tracker/.
6313 NAME: announce_period
6315 LOC: Config.Announce.period
6317 DEFAULT_DOC: Announcement messages disabled.
6319 This is how frequently to send cache announcements.
6321 To enable announcing your cache, just set an announce period.
6324 announce_period 1 day
6329 DEFAULT: tracker.ircache.net
6330 LOC: Config.Announce.host
6332 Set the hostname where announce registration messages will be sent.
6334 See also announce_port and announce_file
6340 LOC: Config.Announce.file
6342 The contents of this file will be included in the announce
6343 registration messages.
6349 LOC: Config.Announce.port
6351 Set the port where announce registration messages will be sent.
6353 See also announce_host and announce_file
6357 HTTPD-ACCELERATOR OPTIONS
6358 -----------------------------------------------------------------------------
6361 NAME: httpd_accel_surrogate_id
6364 DEFAULT_DOC: visible_hostname is used if no specific ID is set.
6365 LOC: Config.Accel.surrogate_id
6367 Surrogates (http://www.esi.org/architecture_spec_1.0.html)
6368 need an identification token to allow control targeting. Because
6369 a farm of surrogates may all perform the same tasks, they may share
6370 an identification token.
6373 NAME: http_accel_surrogate_remote
6377 LOC: Config.onoff.surrogate_is_remote
6379 Remote surrogates (such as those in a CDN) honour the header
6380 "Surrogate-Control: no-store-remote".
6382 Set this to on to have squid behave as a remote surrogate.
6386 IFDEF: USE_SQUID_ESI
6387 COMMENT: libxml2|expat|custom
6389 LOC: ESIParser::Type
6392 ESI markup is not strictly XML compatible. The custom ESI parser
6393 will give higher performance, but cannot handle non ASCII character
6398 DELAY POOL PARAMETERS
6399 -----------------------------------------------------------------------------
6403 TYPE: delay_pool_count
6405 IFDEF: USE_DELAY_POOLS
6408 This represents the number of delay pools to be used. For example,
6409 if you have one class 2 delay pool and one class 3 delays pool, you
6410 have a total of 2 delay pools.
6412 See also delay_parameters, delay_class, delay_access for pool
6413 configuration details.
6417 TYPE: delay_pool_class
6419 IFDEF: USE_DELAY_POOLS
6422 This defines the class of each delay pool. There must be exactly one
6423 delay_class line for each delay pool. For example, to define two
6424 delay pools, one of class 2 and one of class 3, the settings above
6428 delay_pools 4 # 4 delay pools
6429 delay_class 1 2 # pool 1 is a class 2 pool
6430 delay_class 2 3 # pool 2 is a class 3 pool
6431 delay_class 3 4 # pool 3 is a class 4 pool
6432 delay_class 4 5 # pool 4 is a class 5 pool
6434 The delay pool classes are:
6436 class 1 Everything is limited by a single aggregate
6439 class 2 Everything is limited by a single aggregate
6440 bucket as well as an "individual" bucket chosen
6441 from bits 25 through 32 of the IPv4 address.
6443 class 3 Everything is limited by a single aggregate
6444 bucket as well as a "network" bucket chosen
6445 from bits 17 through 24 of the IP address and a
6446 "individual" bucket chosen from bits 17 through
6447 32 of the IPv4 address.
6449 class 4 Everything in a class 3 delay pool, with an
6450 additional limit on a per user basis. This
6451 only takes effect if the username is established
6452 in advance - by forcing authentication in your
6455 class 5 Requests are grouped according their tag (see
6456 external_acl's tag= reply).
6459 Each pool also requires a delay_parameters directive to configure the pool size
6460 and speed limits used whenever the pool is applied to a request. Along with
6461 a set of delay_access directives to determine when it is used.
6463 NOTE: If an IP address is a.b.c.d
6464 -> bits 25 through 32 are "d"
6465 -> bits 17 through 24 are "c"
6466 -> bits 17 through 32 are "c * 256 + d"
6468 NOTE-2: Due to the use of bitmasks in class 2,3,4 pools they only apply to
6469 IPv4 traffic. Class 1 and 5 pools may be used with IPv6 traffic.
6471 This clause only supports fast acl types.
6472 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
6474 See also delay_parameters and delay_access.
6478 TYPE: delay_pool_access
6480 DEFAULT_DOC: Deny using the pool, unless allow rules exist in squid.conf for the pool.
6481 IFDEF: USE_DELAY_POOLS
6484 This is used to determine which delay pool a request falls into.
6486 delay_access is sorted per pool and the matching starts with pool 1,
6487 then pool 2, ..., and finally pool N. The first delay pool where the
6488 request is allowed is selected for the request. If it does not allow
6489 the request to any pool then the request is not delayed (default).
6491 For example, if you want some_big_clients in delay
6492 pool 1 and lotsa_little_clients in delay pool 2:
6494 delay_access 1 allow some_big_clients
6495 delay_access 1 deny all
6496 delay_access 2 allow lotsa_little_clients
6497 delay_access 2 deny all
6498 delay_access 3 allow authenticated_clients
6500 See also delay_parameters and delay_class.
6504 NAME: delay_parameters
6505 TYPE: delay_pool_rates
6507 IFDEF: USE_DELAY_POOLS
6510 This defines the parameters for a delay pool. Each delay pool has
6511 a number of "buckets" associated with it, as explained in the
6512 description of delay_class.
6514 For a class 1 delay pool, the syntax is:
6516 delay_parameters pool aggregate
6518 For a class 2 delay pool:
6520 delay_parameters pool aggregate individual
6522 For a class 3 delay pool:
6524 delay_parameters pool aggregate network individual
6526 For a class 4 delay pool:
6528 delay_parameters pool aggregate network individual user
6530 For a class 5 delay pool:
6532 delay_parameters pool tagrate
6534 The option variables are:
6536 pool a pool number - ie, a number between 1 and the
6537 number specified in delay_pools as used in
6540 aggregate the speed limit parameters for the aggregate bucket
6543 individual the speed limit parameters for the individual
6544 buckets (class 2, 3).
6546 network the speed limit parameters for the network buckets
6549 user the speed limit parameters for the user buckets
6552 tagrate the speed limit parameters for the tag buckets
6555 A pair of delay parameters is written restore/maximum, where restore is
6556 the number of bytes (not bits - modem and network speeds are usually
6557 quoted in bits) per second placed into the bucket, and maximum is the
6558 maximum number of bytes which can be in the bucket at any time.
6560 There must be one delay_parameters line for each delay pool.
6563 For example, if delay pool number 1 is a class 2 delay pool as in the
6564 above example, and is being used to strictly limit each host to 64Kbit/sec
6565 (plus overheads), with no overall limit, the line is:
6567 delay_parameters 1 none 8000/8000
6569 Note that 8 x 8000 KByte/sec -> 64Kbit/sec.
6571 Note that the word 'none' is used to represent no limit.
6574 And, if delay pool number 2 is a class 3 delay pool as in the above
6575 example, and you want to limit it to a total of 256Kbit/sec (strict limit)
6576 with each 8-bit network permitted 64Kbit/sec (strict limit) and each
6577 individual host permitted 4800bit/sec with a bucket maximum size of 64Kbits
6578 to permit a decent web page to be downloaded at a decent speed
6579 (if the network is not being limited due to overuse) but slow down
6580 large downloads more significantly:
6582 delay_parameters 2 32000/32000 8000/8000 600/8000
6584 Note that 8 x 32000 KByte/sec -> 256Kbit/sec.
6585 8 x 8000 KByte/sec -> 64Kbit/sec.
6586 8 x 600 Byte/sec -> 4800bit/sec.
6589 Finally, for a class 4 delay pool as in the example - each user will
6590 be limited to 128Kbits/sec no matter how many workstations they are logged into.:
6592 delay_parameters 4 32000/32000 8000/8000 600/64000 16000/16000
6595 See also delay_class and delay_access.
6599 NAME: delay_initial_bucket_level
6600 COMMENT: (percent, 0-100)
6603 IFDEF: USE_DELAY_POOLS
6604 LOC: Config.Delay.initial
6606 The initial bucket percentage is used to determine how much is put
6607 in each bucket when squid starts, is reconfigured, or first notices
6608 a host accessing it (in class 2 and class 3, individual hosts and
6609 networks only have buckets associated with them once they have been
6614 CLIENT DELAY POOL PARAMETERS
6615 -----------------------------------------------------------------------------
6618 NAME: client_delay_pools
6619 TYPE: client_delay_pool_count
6621 IFDEF: USE_DELAY_POOLS
6622 LOC: Config.ClientDelay
6624 This option specifies the number of client delay pools used. It must
6625 preceed other client_delay_* options.
6628 client_delay_pools 2
6630 See also client_delay_parameters and client_delay_access.
6633 NAME: client_delay_initial_bucket_level
6634 COMMENT: (percent, 0-no_limit)
6637 IFDEF: USE_DELAY_POOLS
6638 LOC: Config.ClientDelay.initial
6640 This option determines the initial bucket size as a percentage of
6641 max_bucket_size from client_delay_parameters. Buckets are created
6642 at the time of the "first" connection from the matching IP. Idle
6643 buckets are periodically deleted up.
6645 You can specify more than 100 percent but note that such "oversized"
6646 buckets are not refilled until their size goes down to max_bucket_size
6647 from client_delay_parameters.
6650 client_delay_initial_bucket_level 50
6653 NAME: client_delay_parameters
6654 TYPE: client_delay_pool_rates
6656 IFDEF: USE_DELAY_POOLS
6657 LOC: Config.ClientDelay
6660 This option configures client-side bandwidth limits using the
6663 client_delay_parameters pool speed_limit max_bucket_size
6665 pool is an integer ID used for client_delay_access matching.
6667 speed_limit is bytes added to the bucket per second.
6669 max_bucket_size is the maximum size of a bucket, enforced after any
6670 speed_limit additions.
6672 Please see the delay_parameters option for more information and
6676 client_delay_parameters 1 1024 2048
6677 client_delay_parameters 2 51200 16384
6679 See also client_delay_access.
6683 NAME: client_delay_access
6684 TYPE: client_delay_pool_access
6686 DEFAULT_DOC: Deny use of the pool, unless allow rules exist in squid.conf for the pool.
6687 IFDEF: USE_DELAY_POOLS
6688 LOC: Config.ClientDelay
6690 This option determines the client-side delay pool for the
6693 client_delay_access pool_ID allow|deny acl_name
6695 All client_delay_access options are checked in their pool ID
6696 order, starting with pool 1. The first checked pool with allowed
6697 request is selected for the request. If no ACL matches or there
6698 are no client_delay_access options, the request bandwidth is not
6701 The ACL-selected pool is then used to find the
6702 client_delay_parameters for the request. Client-side pools are
6703 not used to aggregate clients. Clients are always aggregated
6704 based on their source IP addresses (one bucket per source IP).
6706 This clause only supports fast acl types.
6707 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
6708 Additionally, only the client TCP connection details are available.
6709 ACLs testing HTTP properties will not work.
6711 Please see delay_access for more examples.
6714 client_delay_access 1 allow low_rate_network
6715 client_delay_access 2 allow vips_network
6718 See also client_delay_parameters and client_delay_pools.
6722 WCCPv1 AND WCCPv2 CONFIGURATION OPTIONS
6723 -----------------------------------------------------------------------------
6728 LOC: Config.Wccp.router
6730 DEFAULT_DOC: WCCP disabled.
6733 Use this option to define your WCCP ``home'' router for
6736 wccp_router supports a single WCCP(v1) router
6738 wccp2_router supports multiple WCCPv2 routers
6740 only one of the two may be used at the same time and defines
6741 which version of WCCP to use.
6745 TYPE: IpAddress_list
6746 LOC: Config.Wccp2.router
6748 DEFAULT_DOC: WCCPv2 disabled.
6751 Use this option to define your WCCP ``home'' router for
6754 wccp_router supports a single WCCP(v1) router
6756 wccp2_router supports multiple WCCPv2 routers
6758 only one of the two may be used at the same time and defines
6759 which version of WCCP to use.
6764 LOC: Config.Wccp.version
6768 This directive is only relevant if you need to set up WCCP(v1)
6769 to some very old and end-of-life Cisco routers. In all other
6770 setups it must be left unset or at the default setting.
6771 It defines an internal version in the WCCP(v1) protocol,
6772 with version 4 being the officially documented protocol.
6774 According to some users, Cisco IOS 11.2 and earlier only
6775 support WCCP version 3. If you're using that or an earlier
6776 version of IOS, you may need to change this value to 3, otherwise
6777 do not specify this parameter.
6780 NAME: wccp2_rebuild_wait
6782 LOC: Config.Wccp2.rebuildwait
6786 If this is enabled Squid will wait for the cache dir rebuild to finish
6787 before sending the first wccp2 HereIAm packet
6790 NAME: wccp2_forwarding_method
6792 LOC: Config.Wccp2.forwarding_method
6796 WCCP2 allows the setting of forwarding methods between the
6797 router/switch and the cache. Valid values are as follows:
6799 gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
6800 l2 - L2 redirect (forward the packet using Layer 2/MAC rewriting)
6802 Currently (as of IOS 12.4) cisco routers only support GRE.
6803 Cisco switches only support the L2 redirect assignment method.
6806 NAME: wccp2_return_method
6808 LOC: Config.Wccp2.return_method
6812 WCCP2 allows the setting of return methods between the
6813 router/switch and the cache for packets that the cache
6814 decides not to handle. Valid values are as follows:
6816 gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel)
6817 l2 - L2 redirect (forward the packet using Layer 2/MAC rewriting)
6819 Currently (as of IOS 12.4) cisco routers only support GRE.
6820 Cisco switches only support the L2 redirect assignment.
6822 If the "ip wccp redirect exclude in" command has been
6823 enabled on the cache interface, then it is still safe for
6824 the proxy server to use a l2 redirect method even if this
6825 option is set to GRE.
6828 NAME: wccp2_assignment_method
6830 LOC: Config.Wccp2.assignment_method
6834 WCCP2 allows the setting of methods to assign the WCCP hash
6835 Valid values are as follows:
6837 hash - Hash assignment
6838 mask - Mask assignment
6840 As a general rule, cisco routers support the hash assignment method
6841 and cisco switches support the mask assignment method.
6846 LOC: Config.Wccp2.info
6847 DEFAULT_IF_NONE: standard 0
6848 DEFAULT_DOC: Use the 'web-cache' standard service.
6851 WCCP2 allows for multiple traffic services. There are two
6852 types: "standard" and "dynamic". The standard type defines
6853 one service id - http (id 0). The dynamic service ids can be from
6854 51 to 255 inclusive. In order to use a dynamic service id
6855 one must define the type of traffic to be redirected; this is done
6856 using the wccp2_service_info option.
6858 The "standard" type does not require a wccp2_service_info option,
6859 just specifying the service id will suffice.
6861 MD5 service authentication can be enabled by adding
6862 "password=<password>" to the end of this service declaration.
6866 wccp2_service standard 0 # for the 'web-cache' standard service
6867 wccp2_service dynamic 80 # a dynamic service type which will be
6868 # fleshed out with subsequent options.
6869 wccp2_service standard 0 password=foo
6872 NAME: wccp2_service_info
6873 TYPE: wccp2_service_info
6874 LOC: Config.Wccp2.info
6878 Dynamic WCCPv2 services require further information to define the
6879 traffic you wish to have diverted.
6883 wccp2_service_info <id> protocol=<protocol> flags=<flag>,<flag>..
6884 priority=<priority> ports=<port>,<port>..
6886 The relevant WCCPv2 flags:
6887 + src_ip_hash, dst_ip_hash
6888 + source_port_hash, dst_port_hash
6889 + src_ip_alt_hash, dst_ip_alt_hash
6890 + src_port_alt_hash, dst_port_alt_hash
6893 The port list can be one to eight entries.
6897 wccp2_service_info 80 protocol=tcp flags=src_ip_hash,ports_source
6898 priority=240 ports=80
6900 Note: the service id must have been defined by a previous
6901 'wccp2_service dynamic <id>' entry.
6906 LOC: Config.Wccp2.weight
6910 Each cache server gets assigned a set of the destination
6911 hash proportional to their weight.
6916 LOC: Config.Wccp.address
6918 DEFAULT_DOC: Address selected by the operating system.
6921 Use this option if you require WCCPv2 to use a specific
6924 The default behavior is to not bind to any specific address.
6929 LOC: Config.Wccp2.address
6931 DEFAULT_DOC: Address selected by the operating system.
6934 Use this option if you require WCCP to use a specific
6937 The default behavior is to not bind to any specific address.
6941 PERSISTENT CONNECTION HANDLING
6942 -----------------------------------------------------------------------------
6944 Also see "pconn_timeout" in the TIMEOUTS section
6947 NAME: client_persistent_connections
6949 LOC: Config.onoff.client_pconns
6952 Persistent connection support for clients.
6953 Squid uses persistent connections (when allowed). You can use
6954 this option to disable persistent connections with clients.
6957 NAME: server_persistent_connections
6959 LOC: Config.onoff.server_pconns
6962 Persistent connection support for servers.
6963 Squid uses persistent connections (when allowed). You can use
6964 this option to disable persistent connections with servers.
6967 NAME: persistent_connection_after_error
6969 LOC: Config.onoff.error_pconns
6972 With this directive the use of persistent connections after
6973 HTTP errors can be disabled. Useful if you have clients
6974 who fail to handle errors on persistent connections proper.
6977 NAME: detect_broken_pconn
6979 LOC: Config.onoff.detect_broken_server_pconns
6982 Some servers have been found to incorrectly signal the use
6983 of HTTP/1.0 persistent connections even on replies not
6984 compatible, causing significant delays. This server problem
6985 has mostly been seen on redirects.
6987 By enabling this directive Squid attempts to detect such
6988 broken replies and automatically assume the reply is finished
6989 after 10 seconds timeout.
6993 CACHE DIGEST OPTIONS
6994 -----------------------------------------------------------------------------
6997 NAME: digest_generation
6998 IFDEF: USE_CACHE_DIGESTS
7000 LOC: Config.onoff.digest_generation
7003 This controls whether the server will generate a Cache Digest
7004 of its contents. By default, Cache Digest generation is
7005 enabled if Squid is compiled with --enable-cache-digests defined.
7008 NAME: digest_bits_per_entry
7009 IFDEF: USE_CACHE_DIGESTS
7011 LOC: Config.digest.bits_per_entry
7014 This is the number of bits of the server's Cache Digest which
7015 will be associated with the Digest entry for a given HTTP
7016 Method and URL (public key) combination. The default is 5.
7019 NAME: digest_rebuild_period
7020 IFDEF: USE_CACHE_DIGESTS
7023 LOC: Config.digest.rebuild_period
7026 This is the wait time between Cache Digest rebuilds.
7029 NAME: digest_rewrite_period
7031 IFDEF: USE_CACHE_DIGESTS
7033 LOC: Config.digest.rewrite_period
7036 This is the wait time between Cache Digest writes to
7040 NAME: digest_swapout_chunk_size
7043 IFDEF: USE_CACHE_DIGESTS
7044 LOC: Config.digest.swapout_chunk_size
7047 This is the number of bytes of the Cache Digest to write to
7048 disk at a time. It defaults to 4096 bytes (4KB), the Squid
7052 NAME: digest_rebuild_chunk_percentage
7053 COMMENT: (percent, 0-100)
7054 IFDEF: USE_CACHE_DIGESTS
7056 LOC: Config.digest.rebuild_chunk_percentage
7059 This is the percentage of the Cache Digest to be scanned at a
7060 time. By default it is set to 10% of the Cache Digest.
7065 -----------------------------------------------------------------------------
7070 LOC: Config.Port.snmp
7072 DEFAULT_DOC: SNMP disabled.
7075 The port number where Squid listens for SNMP requests. To enable
7076 SNMP support set this to a suitable port number. Port number
7077 3401 is often used for the Squid SNMP agent. By default it's
7078 set to "0" (disabled)
7086 LOC: Config.accessList.snmp
7088 DEFAULT_DOC: Deny, unless rules exist in squid.conf.
7091 Allowing or denying access to the SNMP port.
7093 All access to the agent is denied by default.
7096 snmp_access allow|deny [!]aclname ...
7098 This clause only supports fast acl types.
7099 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
7102 snmp_access allow snmppublic localhost
7103 snmp_access deny all
7106 NAME: snmp_incoming_address
7108 LOC: Config.Addrs.snmp_incoming
7110 DEFAULT_DOC: Accept SNMP packets from all machine interfaces.
7113 Just like 'udp_incoming_address', but for the SNMP port.
7115 snmp_incoming_address is used for the SNMP socket receiving
7116 messages from SNMP agents.
7118 The default snmp_incoming_address is to listen on all
7119 available network interfaces.
7122 NAME: snmp_outgoing_address
7124 LOC: Config.Addrs.snmp_outgoing
7126 DEFAULT_DOC: Use snmp_incoming_address or an address selected by the operating system.
7129 Just like 'udp_outgoing_address', but for the SNMP port.
7131 snmp_outgoing_address is used for SNMP packets returned to SNMP
7134 If snmp_outgoing_address is not set it will use the same socket
7135 as snmp_incoming_address. Only change this if you want to have
7136 SNMP replies sent using another address than where this Squid
7137 listens for SNMP queries.
7139 NOTE, snmp_incoming_address and snmp_outgoing_address can not have
7140 the same value since they both use the same port.
7145 -----------------------------------------------------------------------------
7148 NAME: icp_port udp_port
7151 DEFAULT_DOC: ICP disabled.
7152 LOC: Config.Port.icp
7154 The port number where Squid sends and receives ICP queries to
7155 and from neighbor caches. The standard UDP port for ICP is 3130.
7158 icp_port @DEFAULT_ICP_PORT@
7165 DEFAULT_DOC: HTCP disabled.
7166 LOC: Config.Port.htcp
7168 The port number where Squid sends and receives HTCP queries to
7169 and from neighbor caches. To turn it on you want to set it to
7176 NAME: log_icp_queries
7180 LOC: Config.onoff.log_udp
7182 If set, ICP queries are logged to access.log. You may wish
7183 do disable this if your ICP load is VERY high to speed things
7184 up or to simplify log analysis.
7187 NAME: udp_incoming_address
7189 LOC:Config.Addrs.udp_incoming
7191 DEFAULT_DOC: Accept packets from all machine interfaces.
7193 udp_incoming_address is used for UDP packets received from other
7196 The default behavior is to not bind to any specific address.
7198 Only change this if you want to have all UDP queries received on
7199 a specific interface/address.
7201 NOTE: udp_incoming_address is used by the ICP, HTCP, and DNS
7202 modules. Altering it will affect all of them in the same manner.
7204 see also; udp_outgoing_address
7206 NOTE, udp_incoming_address and udp_outgoing_address can not
7207 have the same value since they both use the same port.
7210 NAME: udp_outgoing_address
7212 LOC: Config.Addrs.udp_outgoing
7214 DEFAULT_DOC: Use udp_incoming_address or an address selected by the operating system.
7216 udp_outgoing_address is used for UDP packets sent out to other
7219 The default behavior is to not bind to any specific address.
7221 Instead it will use the same socket as udp_incoming_address.
7222 Only change this if you want to have UDP queries sent using another
7223 address than where this Squid listens for UDP queries from other
7226 NOTE: udp_outgoing_address is used by the ICP, HTCP, and DNS
7227 modules. Altering it will affect all of them in the same manner.
7229 see also; udp_incoming_address
7231 NOTE, udp_incoming_address and udp_outgoing_address can not
7232 have the same value since they both use the same port.
7239 LOC: Config.onoff.icp_hit_stale
7241 If you want to return ICP_HIT for stale cache objects, set this
7242 option to 'on'. If you have sibling relationships with caches
7243 in other administrative domains, this should be 'off'. If you only
7244 have sibling relationships with caches under your control,
7245 it is probably okay to set this to 'on'.
7246 If set to 'on', your siblings should use the option "allow-miss"
7247 on their cache_peer lines for connecting to you.
7250 NAME: minimum_direct_hops
7253 LOC: Config.minDirectHops
7255 If using the ICMP pinging stuff, do direct fetches for sites
7256 which are no more than this many hops away.
7259 NAME: minimum_direct_rtt
7263 LOC: Config.minDirectRtt
7265 If using the ICMP pinging stuff, do direct fetches for sites
7266 which are no more than this many rtt milliseconds away.
7272 LOC: Config.Netdb.low
7274 The low water mark for the ICMP measurement database.
7276 Note: high watermark controlled by netdb_high directive.
7278 These watermarks are counts, not percents. The defaults are
7279 (low) 900 and (high) 1000. When the high water mark is
7280 reached, database entries will be deleted until the low
7287 LOC: Config.Netdb.high
7289 The high water mark for the ICMP measurement database.
7291 Note: low watermark controlled by netdb_low directive.
7293 These watermarks are counts, not percents. The defaults are
7294 (low) 900 and (high) 1000. When the high water mark is
7295 reached, database entries will be deleted until the low
7299 NAME: netdb_ping_period
7301 LOC: Config.Netdb.period
7304 The minimum period for measuring a site. There will be at
7305 least this much delay between successive pings to the same
7306 network. The default is five minutes.
7313 LOC: Config.onoff.query_icmp
7315 If you want to ask your peers to include ICMP data in their ICP
7316 replies, enable this option.
7318 If your peer has configured Squid (during compilation) with
7319 '--enable-icmp' that peer will send ICMP pings to origin server
7320 sites of the URLs it receives. If you enable this option the
7321 ICP replies from that peer will include the ICMP data (if available).
7322 Then, when choosing a parent cache, Squid will choose the parent with
7323 the minimal RTT to the origin server. When this happens, the
7324 hierarchy field of the access.log will be
7325 "CLOSEST_PARENT_MISS". This option is off by default.
7328 NAME: test_reachability
7332 LOC: Config.onoff.test_reachability
7334 When this is 'on', ICP MISS replies will be ICP_MISS_NOFETCH
7335 instead of ICP_MISS if the target host is NOT in the ICMP
7336 database, or has a zero RTT.
7339 NAME: icp_query_timeout
7342 DEFAULT_DOC: Dynamic detection.
7344 LOC: Config.Timeout.icp_query
7346 Normally Squid will automatically determine an optimal ICP
7347 query timeout value based on the round-trip-time of recent ICP
7348 queries. If you want to override the value determined by
7349 Squid, set this 'icp_query_timeout' to a non-zero value. This
7350 value is specified in MILLISECONDS, so, to use a 2-second
7351 timeout (the old default), you would write:
7353 icp_query_timeout 2000
7356 NAME: maximum_icp_query_timeout
7360 LOC: Config.Timeout.icp_query_max
7362 Normally the ICP query timeout is determined dynamically. But
7363 sometimes it can lead to very large values (say 5 seconds).
7364 Use this option to put an upper limit on the dynamic timeout
7365 value. Do NOT use this option to always use a fixed (instead
7366 of a dynamic) timeout value. To set a fixed timeout see the
7367 'icp_query_timeout' directive.
7370 NAME: minimum_icp_query_timeout
7374 LOC: Config.Timeout.icp_query_min
7376 Normally the ICP query timeout is determined dynamically. But
7377 sometimes it can lead to very small timeouts, even lower than
7378 the normal latency variance on your link due to traffic.
7379 Use this option to put an lower limit on the dynamic timeout
7380 value. Do NOT use this option to always use a fixed (instead
7381 of a dynamic) timeout value. To set a fixed timeout see the
7382 'icp_query_timeout' directive.
7385 NAME: background_ping_rate
7389 LOC: Config.backgroundPingRate
7391 Controls how often the ICP pings are sent to siblings that
7392 have background-ping set.
7396 MULTICAST ICP OPTIONS
7397 -----------------------------------------------------------------------------
7402 LOC: Config.mcast_group_list
7405 This tag specifies a list of multicast groups which your server
7406 should join to receive multicasted ICP queries.
7408 NOTE! Be very careful what you put here! Be sure you
7409 understand the difference between an ICP _query_ and an ICP
7410 _reply_. This option is to be set only if you want to RECEIVE
7411 multicast queries. Do NOT set this option to SEND multicast
7412 ICP (use cache_peer for that). ICP replies are always sent via
7413 unicast, so this option does not affect whether or not you will
7414 receive replies from multicast group members.
7416 You must be very careful to NOT use a multicast address which
7417 is already in use by another group of caches.
7419 If you are unsure about multicast, please read the Multicast
7420 chapter in the Squid FAQ (http://www.squid-cache.org/FAQ/).
7422 Usage: mcast_groups 239.128.16.128 224.0.1.20
7424 By default, Squid doesn't listen on any multicast groups.
7427 NAME: mcast_miss_addr
7428 IFDEF: MULTICAST_MISS_STREAM
7430 LOC: Config.mcast_miss.addr
7432 DEFAULT_DOC: disabled.
7434 If you enable this option, every "cache miss" URL will
7435 be sent out on the specified multicast address.
7437 Do not enable this option unless you are are absolutely
7438 certain you understand what you are doing.
7441 NAME: mcast_miss_ttl
7442 IFDEF: MULTICAST_MISS_STREAM
7444 LOC: Config.mcast_miss.ttl
7447 This is the time-to-live value for packets multicasted
7448 when multicasting off cache miss URLs is enabled. By
7449 default this is set to 'site scope', i.e. 16.
7452 NAME: mcast_miss_port
7453 IFDEF: MULTICAST_MISS_STREAM
7455 LOC: Config.mcast_miss.port
7458 This is the port number to be used in conjunction with
7462 NAME: mcast_miss_encode_key
7463 IFDEF: MULTICAST_MISS_STREAM
7465 LOC: Config.mcast_miss.encode_key
7466 DEFAULT: XXXXXXXXXXXXXXXX
7468 The URLs that are sent in the multicast miss stream are
7469 encrypted. This is the encryption key.
7472 NAME: mcast_icp_query_timeout
7476 LOC: Config.Timeout.mcast_icp_query
7478 For multicast peers, Squid regularly sends out ICP "probes" to
7479 count how many other peers are listening on the given multicast
7480 address. This value specifies how long Squid should wait to
7481 count all the replies. The default is 2000 msec, or 2
7486 INTERNAL ICON OPTIONS
7487 -----------------------------------------------------------------------------
7490 NAME: icon_directory
7492 LOC: Config.icons.directory
7493 DEFAULT: @DEFAULT_ICON_DIR@
7495 Where the icons are stored. These are normally kept in
7499 NAME: global_internal_static
7501 LOC: Config.onoff.global_internal_static
7504 This directive controls is Squid should intercept all requests for
7505 /squid-internal-static/ no matter which host the URL is requesting
7506 (default on setting), or if nothing special should be done for
7507 such URLs (off setting). The purpose of this directive is to make
7508 icons etc work better in complex cache hierarchies where it may
7509 not always be possible for all corners in the cache mesh to reach
7510 the server generating a directory listing.
7513 NAME: short_icon_urls
7515 LOC: Config.icons.use_short_names
7518 If this is enabled Squid will use short URLs for icons.
7519 If disabled it will revert to the old behavior of including
7520 it's own name and port in the URL.
7522 If you run a complex cache hierarchy with a mix of Squid and
7523 other proxies you may need to disable this directive.
7528 -----------------------------------------------------------------------------
7531 NAME: error_directory
7533 LOC: Config.errorDirectory
7535 DEFAULT_DOC: Send error pages in the clients preferred language
7537 If you wish to create your own versions of the default
7538 error files to customize them to suit your company copy
7539 the error/template files to another directory and point
7542 WARNING: This option will disable multi-language support
7543 on error pages if used.
7545 The squid developers are interested in making squid available in
7546 a wide variety of languages. If you are making translations for a
7547 language that Squid does not currently provide please consider
7548 contributing your translation back to the project.
7549 http://wiki.squid-cache.org/Translations
7551 The squid developers working on translations are happy to supply drop-in
7552 translated error files in exchange for any new language contributions.
7555 NAME: error_default_language
7556 IFDEF: USE_ERR_LOCALES
7558 LOC: Config.errorDefaultLanguage
7560 DEFAULT_DOC: Generate English language pages.
7562 Set the default language which squid will send error pages in
7563 if no existing translation matches the clients language
7566 If unset (default) generic English will be used.
7568 The squid developers are interested in making squid available in
7569 a wide variety of languages. If you are interested in making
7570 translations for any language see the squid wiki for details.
7571 http://wiki.squid-cache.org/Translations
7574 NAME: error_log_languages
7575 IFDEF: USE_ERR_LOCALES
7577 LOC: Config.errorLogMissingLanguages
7580 Log to cache.log what languages users are attempting to
7581 auto-negotiate for translations.
7583 Successful negotiations are not logged. Only failures
7584 have meaning to indicate that Squid may need an upgrade
7585 of its error page translations.
7588 NAME: err_page_stylesheet
7590 LOC: Config.errorStylesheet
7591 DEFAULT: @DEFAULT_CONFIG_DIR@/errorpage.css
7593 CSS Stylesheet to pattern the display of Squid default error pages.
7595 For information on CSS see http://www.w3.org/Style/CSS/
7600 LOC: Config.errHtmlText
7603 HTML text to include in error messages. Make this a "mailto"
7604 URL to your admin address, or maybe just a link to your
7605 organizations Web page.
7607 To include this in your error messages, you must rewrite
7608 the error template files (found in the "errors" directory).
7609 Wherever you want the 'err_html_text' line to appear,
7610 insert a %L tag in the error template file.
7613 NAME: email_err_data
7616 LOC: Config.onoff.emailErrData
7619 If enabled, information about the occurred error will be
7620 included in the mailto links of the ERR pages (if %W is set)
7621 so that the email body contains the data.
7622 Syntax is <A HREF="mailto:%w%W">%w</A>
7627 LOC: Config.denyInfoList
7630 Usage: deny_info err_page_name acl
7631 or deny_info http://... acl
7632 or deny_info TCP_RESET acl
7634 This can be used to return a ERR_ page for requests which
7635 do not pass the 'http_access' rules. Squid remembers the last
7636 acl it evaluated in http_access, and if a 'deny_info' line exists
7637 for that ACL Squid returns a corresponding error page.
7639 The acl is typically the last acl on the http_access deny line which
7640 denied access. The exceptions to this rule are:
7641 - When Squid needs to request authentication credentials. It's then
7642 the first authentication related acl encountered
7643 - When none of the http_access lines matches. It's then the last
7644 acl processed on the last http_access line.
7645 - When the decision to deny access was made by an adaptation service,
7646 the acl name is the corresponding eCAP or ICAP service_name.
7648 NP: If providing your own custom error pages with error_directory
7649 you may also specify them by your custom file name:
7650 Example: deny_info ERR_CUSTOM_ACCESS_DENIED bad_guys
7652 By defaut Squid will send "403 Forbidden". A different 4xx or 5xx
7653 may be specified by prefixing the file name with the code and a colon.
7654 e.g. 404:ERR_CUSTOM_ACCESS_DENIED
7656 Alternatively you can tell Squid to reset the TCP connection
7657 by specifying TCP_RESET.
7659 Or you can specify an error URL or URL pattern. The browsers will
7660 get redirected to the specified URL after formatting tags have
7661 been replaced. Redirect will be done with 302 or 307 according to
7662 HTTP/1.1 specs. A different 3xx code may be specified by prefixing
7663 the URL. e.g. 303:http://example.com/
7666 %a - username (if available. Password NOT included)
7669 %E - Error description
7671 %H - Request domain name
7672 %i - Client IP Address
7674 %o - Message result from external ACL helper
7675 %p - Request Port number
7676 %P - Request Protocol name
7677 %R - Request URL path
7678 %T - Timestamp in RFC 1123 format
7679 %U - Full canonical URL from client
7680 (HTTPS URLs terminate with *)
7681 %u - Full canonical URL from client
7682 %w - Admin email from squid.conf
7684 %% - Literal percent (%) code
7689 OPTIONS INFLUENCING REQUEST FORWARDING
7690 -----------------------------------------------------------------------------
7693 NAME: nonhierarchical_direct
7695 LOC: Config.onoff.nonhierarchical_direct
7698 By default, Squid will send any non-hierarchical requests
7699 (not cacheable request type) direct to origin servers.
7701 When this is set to "off", Squid will prefer to send these
7702 requests to parents.
7704 Note that in most configurations, by turning this off you will only
7705 add latency to these request without any improvement in global hit
7708 This option only sets a preference. If the parent is unavailable a
7709 direct connection to the origin server may still be attempted. To
7710 completely prevent direct connections use never_direct.
7715 LOC: Config.onoff.prefer_direct
7718 Normally Squid tries to use parents for most requests. If you for some
7719 reason like it to first try going direct and only use a parent if
7720 going direct fails set this to on.
7722 By combining nonhierarchical_direct off and prefer_direct on you
7723 can set up Squid to use a parent as a backup path if going direct
7726 Note: If you want Squid to use parents for all requests see
7727 the never_direct directive. prefer_direct only modifies how Squid
7728 acts on cacheable requests.
7731 NAME: cache_miss_revalidate
7735 LOC: Config.onoff.cache_miss_revalidate
7737 RFC 7232 defines a conditional request mechanism to prevent
7738 response objects being unnecessarily transferred over the network.
7739 If that mechanism is used by the client and a cache MISS occurs
7740 it can prevent new cache entries being created.
7742 This option determines whether Squid on cache MISS will pass the
7743 client revalidation request to the server or tries to fetch new
7744 content for caching. It can be useful while the cache is mostly
7745 empty to more quickly have the cache populated by generating
7746 non-conditional GETs.
7748 When set to 'on' (default), Squid will pass all client If-* headers
7749 to the server. This permits server responses without a cacheable
7750 payload to be delivered and on MISS no new cache entry is created.
7752 When set to 'off' and if the request is cacheable, Squid will
7753 remove the clients If-Modified-Since and If-None-Match headers from
7754 the request sent to the server. This requests a 200 status response
7755 from the server to create a new cache entry with.
7760 LOC: Config.accessList.AlwaysDirect
7762 DEFAULT_DOC: Prevent any cache_peer being used for this request.
7764 Usage: always_direct allow|deny [!]aclname ...
7766 Here you can use ACL elements to specify requests which should
7767 ALWAYS be forwarded by Squid to the origin servers without using
7768 any peers. For example, to always directly forward requests for
7769 local servers ignoring any parents or siblings you may have use
7772 acl local-servers dstdomain my.domain.net
7773 always_direct allow local-servers
7775 To always forward FTP requests directly, use
7778 always_direct allow FTP
7780 NOTE: There is a similar, but opposite option named
7781 'never_direct'. You need to be aware that "always_direct deny
7782 foo" is NOT the same thing as "never_direct allow foo". You
7783 may need to use a deny rule to exclude a more-specific case of
7784 some other rule. Example:
7786 acl local-external dstdomain external.foo.net
7787 acl local-servers dstdomain .foo.net
7788 always_direct deny local-external
7789 always_direct allow local-servers
7791 NOTE: If your goal is to make the client forward the request
7792 directly to the origin server bypassing Squid then this needs
7793 to be done in the client configuration. Squid configuration
7794 can only tell Squid how Squid should fetch the object.
7796 NOTE: This directive is not related to caching. The replies
7797 is cached as usual even if you use always_direct. To not cache
7798 the replies see the 'cache' directive.
7800 This clause supports both fast and slow acl types.
7801 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
7806 LOC: Config.accessList.NeverDirect
7808 DEFAULT_DOC: Allow DNS results to be used for this request.
7810 Usage: never_direct allow|deny [!]aclname ...
7812 never_direct is the opposite of always_direct. Please read
7813 the description for always_direct if you have not already.
7815 With 'never_direct' you can use ACL elements to specify
7816 requests which should NEVER be forwarded directly to origin
7817 servers. For example, to force the use of a proxy for all
7818 requests, except those in your local domain use something like:
7820 acl local-servers dstdomain .foo.net
7821 never_direct deny local-servers
7822 never_direct allow all
7824 or if Squid is inside a firewall and there are local intranet
7825 servers inside the firewall use something like:
7827 acl local-intranet dstdomain .foo.net
7828 acl local-external dstdomain external.foo.net
7829 always_direct deny local-external
7830 always_direct allow local-intranet
7831 never_direct allow all
7833 This clause supports both fast and slow acl types.
7834 See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details.
7838 ADVANCED NETWORKING OPTIONS
7839 -----------------------------------------------------------------------------
7842 NAME: incoming_udp_average incoming_icp_average
7845 LOC: Config.comm_incoming.udp.average
7847 Heavy voodoo here. I can't even believe you are reading this.
7848 Are you crazy? Don't even think about adjusting these unless
7849 you understand the algorithms in comm_select.c first!
7852 NAME: incoming_tcp_average incoming_http_average
7855 LOC: Config.comm_incoming.tcp.average
7857 Heavy voodoo here. I can't even believe you are reading this.
7858 Are you crazy? Don't even think about adjusting these unless
7859 you understand the algorithms in comm_select.c first!
7862 NAME: incoming_dns_average
7865 LOC: Config.comm_incoming.dns.average
7867 Heavy voodoo here. I can't even believe you are reading this.
7868 Are you crazy? Don't even think about adjusting these unless
7869 you understand the algorithms in comm_select.c first!
7872 NAME: min_udp_poll_cnt min_icp_poll_cnt
7875 LOC: Config.comm_incoming.udp.min_poll
7877 Heavy voodoo here. I can't even believe you are reading this.
7878 Are you crazy? Don't even think about adjusting these unless
7879 you understand the algorithms in comm_select.c first!
7882 NAME: min_dns_poll_cnt
7885 LOC: Config.comm_incoming.dns.min_poll
7887 Heavy voodoo here. I can't even believe you are reading this.
7888 Are you crazy? Don't even think about adjusting these unless
7889 you understand the algorithms in comm_select.c first!
7892 NAME: min_tcp_poll_cnt min_http_poll_cnt
7895 LOC: Config.comm_incoming.tcp.min_poll
7897 Heavy voodoo here. I can't even believe you are reading this.
7898 Are you crazy? Don't even think about adjusting these unless
7899 you understand the algorithms in comm_select.c first!
7905 LOC: Config.accept_filter
7909 The name of an accept(2) filter to install on Squid's
7910 listen socket(s). This feature is perhaps specific to
7911 FreeBSD and requires support in the kernel.
7913 The 'httpready' filter delays delivering new connections
7914 to Squid until a full HTTP request has been received.
7915 See the accf_http(9) man page for details.
7917 The 'dataready' filter delays delivering new connections
7918 to Squid until there is some data to process.
7919 See the accf_dataready(9) man page for details.
7923 The 'data' filter delays delivering of new connections
7924 to Squid until there is some data to process by TCP_ACCEPT_DEFER.
7925 You may optionally specify a number of seconds to wait by
7926 'data=N' where N is the number of seconds. Defaults to 30
7927 if not specified. See the tcp(7) man page for details.
7930 accept_filter httpready
7935 NAME: client_ip_max_connections
7937 LOC: Config.client_ip_max_connections
7939 DEFAULT_DOC: No limit.
7941 Set an absolute limit on the number of connections a single
7942 client IP can use. Any more than this and Squid will begin to drop
7943 new connections from the client until it closes some links.
7945 Note that this is a global limit. It affects all HTTP, HTCP, Gopher and FTP
7946 connections from the client. For finer control use the ACL access controls.
7948 Requires client_db to be enabled (the default).
7950 WARNING: This may noticably slow down traffic received via external proxies
7951 or NAT devices and cause them to rebound error messages back to their clients.
7954 NAME: tcp_recv_bufsize
7958 DEFAULT_DOC: Use operating system TCP defaults.
7959 LOC: Config.tcpRcvBufsz
7961 Size of receive buffer to set for TCP sockets. Probably just
7962 as easy to change your kernel's default.
7963 Omit from squid.conf to use the default buffer size.
7968 -----------------------------------------------------------------------------
7975 LOC: Adaptation::Icap::TheConfig.onoff
7978 If you want to enable the ICAP module support, set this to on.
7981 NAME: icap_connect_timeout
7984 LOC: Adaptation::Icap::TheConfig.connect_timeout_raw
7987 This parameter specifies how long to wait for the TCP connect to
7988 the requested ICAP server to complete before giving up and either
7989 terminating the HTTP transaction or bypassing the failure.
7991 The default for optional services is peer_connect_timeout.
7992 The default for essential services is connect_timeout.
7993 If this option is explicitly set, its value applies to all services.
7996 NAME: icap_io_timeout
8000 DEFAULT_DOC: Use read_timeout.
8001 LOC: Adaptation::Icap::TheConfig.io_timeout_raw
8004 This parameter specifies how long to wait for an I/O activity on
8005 an established, active ICAP connection before giving up and
8006 either terminating the HTTP transaction or bypassing the
8010 NAME: icap_service_failure_limit
8011 COMMENT: limit [in memory-depth time-units]
8012 TYPE: icap_service_failure_limit
8014 LOC: Adaptation::Icap::TheConfig
8017 The limit specifies the number of failures that Squid tolerates
8018 when establishing a new TCP connection with an ICAP service. If
8019 the number of failures exceeds the limit, the ICAP service is
8020 not used for new ICAP requests until it is time to refresh its
8023 A negative value disables the limit. Without the limit, an ICAP
8024 service will not be considered down due to connectivity failures
8025 between ICAP OPTIONS requests.
8027 Squid forgets ICAP service failures older than the specified
8028 value of memory-depth. The memory fading algorithm
8029 is approximate because Squid does not remember individual
8030 errors but groups them instead, splitting the option
8031 value into ten time slots of equal length.
8033 When memory-depth is 0 and by default this option has no
8034 effect on service failure expiration.
8036 Squid always forgets failures when updating service settings
8037 using an ICAP OPTIONS transaction, regardless of this option
8041 # suspend service usage after 10 failures in 5 seconds:
8042 icap_service_failure_limit 10 in 5 seconds
8045 NAME: icap_service_revival_delay
8048 LOC: Adaptation::Icap::TheConfig.service_revival_delay
8051 The delay specifies the number of seconds to wait after an ICAP
8052 OPTIONS request failure before requesting the options again. The
8053 failed ICAP service is considered "down" until fresh OPTIONS are
8056 The actual delay cannot be smaller than the hardcoded minimum
8057 delay of 30 seconds.
8060 NAME: icap_preview_enable
8064 LOC: Adaptation::Icap::TheConfig.preview_enable
8067 The ICAP Preview feature allows the ICAP server to handle the
8068 HTTP message by looking only at the beginning of the message body
8069 or even without receiving the body at all. In some environments,
8070 previews greatly speedup ICAP processing.
8072 During an ICAP OPTIONS transaction, the server may tell Squid what
8073 HTTP messages should be previewed and how big the preview should be.
8074 Squid will not use Preview if the server did not request one.
8076 To disable ICAP Preview for all ICAP services, regardless of
8077 individual ICAP server OPTIONS responses, set this option to "off".
8079 icap_preview_enable off
8082 NAME: icap_preview_size
8085 LOC: Adaptation::Icap::TheConfig.preview_size
8087 DEFAULT_DOC: No preview sent.
8089 The default size of preview data to be sent to the ICAP server.
8090 This value might be overwritten on a per server basis by OPTIONS requests.
8093 NAME: icap_206_enable
8097 LOC: Adaptation::Icap::TheConfig.allow206_enable
8100 206 (Partial Content) responses is an ICAP extension that allows the
8101 ICAP agents to optionally combine adapted and original HTTP message
8102 content. The decision to combine is postponed until the end of the
8103 ICAP response. Squid supports Partial Content extension by default.
8105 Activation of the Partial Content extension is negotiated with each
8106 ICAP service during OPTIONS exchange. Most ICAP servers should handle
8107 negotation correctly even if they do not support the extension, but
8108 some might fail. To disable Partial Content support for all ICAP
8109 services and to avoid any negotiation, set this option to "off".
8115 NAME: icap_default_options_ttl
8118 LOC: Adaptation::Icap::TheConfig.default_options_ttl
8121 The default TTL value for ICAP OPTIONS responses that don't have
8122 an Options-TTL header.
8125 NAME: icap_persistent_connections
8129 LOC: Adaptation::Icap::TheConfig.reuse_connections
8132 Whether or not Squid should use persistent connections to
8136 NAME: adaptation_send_client_ip icap_send_client_ip
8138 IFDEF: USE_ADAPTATION
8140 LOC: Adaptation::Config::send_client_ip
8143 If enabled, Squid shares HTTP client IP information with adaptation
8144 services. For ICAP, Squid adds the X-Client-IP header to ICAP requests.
8145 For eCAP, Squid sets the libecap::metaClientIp transaction option.
8147 See also: adaptation_uses_indirect_client
8150 NAME: adaptation_send_username icap_send_client_username
8152 IFDEF: USE_ADAPTATION
8154 LOC: Adaptation::Config::send_username
8157 This sends authenticated HTTP client username (if available) to
8158 the adaptation service.
8160 For ICAP, the username value is encoded based on the
8161 icap_client_username_encode option and is sent using the header
8162 specified by the icap_client_username_header option.
8165 NAME: icap_client_username_header
8168 LOC: Adaptation::Icap::TheConfig.client_username_header
8169 DEFAULT: X-Client-Username
8171 ICAP request header name to use for adaptation_send_username.
8174 NAME: icap_client_username_encode
8178 LOC: Adaptation::Icap::TheConfig.client_username_encode
8181 Whether to base64 encode the authenticated client username.
8185 TYPE: icap_service_type
8187 LOC: Adaptation::Icap::TheConfig
8190 Defines a single ICAP service using the following format:
8192 icap_service id vectoring_point uri [option ...]
8195 an opaque identifier or name which is used to direct traffic to
8196 this specific service. Must be unique among all adaptation
8197 services in squid.conf.
8199 vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
8200 This specifies at which point of transaction processing the
8201 ICAP service should be activated. *_postcache vectoring points
8202 are not yet supported.
8204 uri: icap://servername:port/servicepath
8205 ICAP server and service location.
8207 ICAP does not allow a single service to handle both REQMOD and RESPMOD
8208 transactions. Squid does not enforce that requirement. You can specify
8209 services with the same service_url and different vectoring_points. You
8210 can even specify multiple identical services as long as their
8211 service_names differ.
8213 To activate a service, use the adaptation_access directive. To group
8214 services, use adaptation_service_chain and adaptation_service_set.
8216 Service options are separated by white space. ICAP services support
8217 the following name=value options:
8220 If set to 'on' or '1', the ICAP service is treated as
8221 optional. If the service cannot be reached or malfunctions,
8222 Squid will try to ignore any errors and process the message as
8223 if the service was not enabled. No all ICAP errors can be
8224 bypassed. If set to 0, the ICAP service is treated as
8225 essential and all ICAP errors will result in an error page
8226 returned to the HTTP client.
8228 Bypass is off by default: services are treated as essential.
8231 If set to 'on' or '1', the ICAP service is allowed to
8232 dynamically change the current message adaptation plan by
8233 returning a chain of services to be used next. The services
8234 are specified using the X-Next-Services ICAP response header
8235 value, formatted as a comma-separated list of service names.
8236 Each named service should be configured in squid.conf. Other
8237 services are ignored. An empty X-Next-Services value results
8238 in an empty plan which ends the current adaptation.
8240 Dynamic adaptation plan may cross or cover multiple supported
8241 vectoring points in their natural processing order.
8243 Routing is not allowed by default: the ICAP X-Next-Services
8244 response header is ignored.
8247 Only has effect on split-stack systems. The default on those systems
8248 is to use IPv4-only connections. When set to 'on' this option will
8249 make Squid use IPv6-only connections to contact this ICAP service.
8251 on-overload=block|bypass|wait|force
8252 If the service Max-Connections limit has been reached, do
8253 one of the following for each new ICAP transaction:
8254 * block: send an HTTP error response to the client
8255 * bypass: ignore the "over-connected" ICAP service
8256 * wait: wait (in a FIFO queue) for an ICAP connection slot
8257 * force: proceed, ignoring the Max-Connections limit
8259 In SMP mode with N workers, each worker assumes the service
8260 connection limit is Max-Connections/N, even though not all
8261 workers may use a given service.
8263 The default value is "bypass" if service is bypassable,
8264 otherwise it is set to "wait".
8268 Use the given number as the Max-Connections limit, regardless
8269 of the Max-Connections value given by the service, if any.
8271 Older icap_service format without optional named parameters is
8272 deprecated but supported for backward compatibility.
8275 icap_service svcBlocker reqmod_precache icap://icap1.mydomain.net:1344/reqmod bypass=0
8276 icap_service svcLogger reqmod_precache icap://icap2.mydomain.net:1344/respmod routing=on
8280 TYPE: icap_class_type
8285 This deprecated option was documented to define an ICAP service
8286 chain, even though it actually defined a set of similar, redundant
8287 services, and the chains were not supported.
8289 To define a set of redundant services, please use the
8290 adaptation_service_set directive. For service chains, use
8291 adaptation_service_chain.
8295 TYPE: icap_access_type
8300 This option is deprecated. Please use adaptation_access, which
8301 has the same ICAP functionality, but comes with better
8302 documentation, and eCAP support.
8307 -----------------------------------------------------------------------------
8314 LOC: Adaptation::Ecap::TheConfig.onoff
8317 Controls whether eCAP support is enabled.
8321 TYPE: ecap_service_type
8323 LOC: Adaptation::Ecap::TheConfig
8326 Defines a single eCAP service
8328 ecap_service id vectoring_point uri [option ...]
8331 an opaque identifier or name which is used to direct traffic to
8332 this specific service. Must be unique among all adaptation
8333 services in squid.conf.
8335 vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache
8336 This specifies at which point of transaction processing the
8337 eCAP service should be activated. *_postcache vectoring points
8338 are not yet supported.
8340 uri: ecap://vendor/service_name?custom&cgi=style¶meters=optional
8341 Squid uses the eCAP service URI to match this configuration
8342 line with one of the dynamically loaded services. Each loaded
8343 eCAP service must have a unique URI. Obtain the right URI from
8344 the service provider.
8346 To activate a service, use the adaptation_access directive. To group
8347 services, use adaptation_service_chain and adaptation_service_set.
8349 Service options are separated by white space. eCAP services support
8350 the following name=value options:
8353 If set to 'on' or '1', the eCAP service is treated as optional.
8354 If the service cannot be reached or malfunctions, Squid will try
8355 to ignore any errors and process the message as if the service
8356 was not enabled. No all eCAP errors can be bypassed.
8357 If set to 'off' or '0', the eCAP service is treated as essential
8358 and all eCAP errors will result in an error page returned to the
8361 Bypass is off by default: services are treated as essential.
8364 If set to 'on' or '1', the eCAP service is allowed to
8365 dynamically change the current message adaptation plan by
8366 returning a chain of services to be used next.
8368 Dynamic adaptation plan may cross or cover multiple supported
8369 vectoring points in their natural processing order.
8371 Routing is not allowed by default.
8373 Older ecap_service format without optional named parameters is
8374 deprecated but supported for backward compatibility.
8378 ecap_service s1 reqmod_precache ecap://filters.R.us/leakDetector?on_error=block bypass=off
8379 ecap_service s2 respmod_precache ecap://filters.R.us/virusFilter config=/etc/vf.cfg bypass=on
8382 NAME: loadable_modules
8384 IFDEF: USE_LOADABLE_MODULES
8385 LOC: Config.loadable_module_names
8388 Instructs Squid to load the specified dynamic module(s) or activate
8389 preloaded module(s).
8391 loadable_modules @DEFAULT_PREFIX@/lib/MinimalAdapter.so
8395 MESSAGE ADAPTATION OPTIONS
8396 -----------------------------------------------------------------------------
8399 NAME: adaptation_service_set
8400 TYPE: adaptation_service_set_type
8401 IFDEF: USE_ADAPTATION
8406 Configures an ordered set of similar, redundant services. This is
8407 useful when hot standby or backup adaptation servers are available.
8409 adaptation_service_set set_name service_name1 service_name2 ...
8411 The named services are used in the set declaration order. The first
8412 applicable adaptation service from the set is used first. The next
8413 applicable service is tried if and only if the transaction with the
8414 previous service fails and the message waiting to be adapted is still
8417 When adaptation starts, broken services are ignored as if they were
8418 not a part of the set. A broken service is a down optional service.
8420 The services in a set must be attached to the same vectoring point
8421 (e.g., pre-cache) and use the same adaptation method (e.g., REQMOD).
8423 If all services in a set are optional then adaptation failures are
8424 bypassable. If all services in the set are essential, then a
8425 transaction failure with one service may still be retried using
8426 another service from the set, but when all services fail, the master
8427 transaction fails as well.
8429 A set may contain a mix of optional and essential services, but that
8430 is likely to lead to surprising results because broken services become
8431 ignored (see above), making previously bypassable failures fatal.
8432 Technically, it is the bypassability of the last failed service that
8435 See also: adaptation_access adaptation_service_chain
8438 adaptation_service_set svcBlocker urlFilterPrimary urlFilterBackup
8439 adaptation service_set svcLogger loggerLocal loggerRemote
8442 NAME: adaptation_service_chain
8443 TYPE: adaptation_service_chain_type
8444 IFDEF: USE_ADAPTATION
8449 Configures a list of complementary services that will be applied
8450 one-by-one, forming an adaptation chain or pipeline. This is useful
8451 when Squid must perform different adaptations on the same message.
8453 adaptation_service_chain chain_name service_name1 svc_name2 ...
8455 The named services are used in the chain declaration order. The first
8456 applicable adaptation service from the chain is used first. The next
8457 applicable service is applied to the successful adaptation results of
8458 the previous service in the chain.
8460 When adaptation starts, broken services are ignored as if they were
8461 not a part of the chain. A broken service is a down optional service.
8463 Request satisfaction terminates the adaptation chain because Squid
8464 does not currently allow declaration of RESPMOD services at the
8465 "reqmod_precache" vectoring point (see icap_service or ecap_service).
8467 The services in a chain must be attached to the same vectoring point
8468 (e.g., pre-cache) and use the same adaptation method (e.g., REQMOD).
8470 A chain may contain a mix of optional and essential services. If an
8471 essential adaptation fails (or the failure cannot be bypassed for
8472 other reasons), the master transaction fails. Otherwise, the failure
8473 is bypassed as if the failed adaptation service was not in the chain.
8475 See also: adaptation_access adaptation_service_set
8478 adaptation_service_chain svcRequest requestLogger urlFilter leakDetector
8481 NAME: adaptation_access
8482 TYPE: adaptation_access_type
8483 IFDEF: USE_ADAPTATION
8486 DEFAULT_DOC: Allow, unless rules exist in squid.conf.
8488 Sends an HTTP transaction to an ICAP or eCAP adaptation service.
8490 adaptation_access service_name allow|deny [!]aclname...
8491 adaptation_access set_name allow|deny [!]aclname...
8493 At each supported vectoring point, the adaptation_access
8494 statements are processed in the order they appear in this
8495 configuration file. Statements pointing to the following services
8496 are ignored (i.e., skipped without checking their ACL):
8498 - services serving different vectoring points
8499 - "broken-but-bypassable" services
8500 - "up" services configured to ignore such transactions
8501 (e.g., based on the ICAP Transfer-Ignore header).
8503 When a set_name is used, all services in the set are checked
8504 using the same rules, to find the first applicable one. See
8505 adaptation_service_set for details.
8507 If an access list is checked and there is a match, the
8508 processing stops: For an "allow" rule, the corresponding
8509 adaptation service is used for the transaction. For a "deny"
8510 rule, no adaptation service is activated.
8512 It is currently not possible to apply more than one adaptation
8513 service at the same vectoring point to the same HTTP transaction.
8515 See also: icap_service and ecap_service
8518 adaptation_access service_1 allow all
8521 NAME: adaptation_service_iteration_limit
8523 IFDEF: USE_ADAPTATION
8524 LOC: Adaptation::Config::service_iteration_limit
8527 Limits the number of iterations allowed when applying adaptation
8528 services to a message. If your longest adaptation set or chain
8529 may have more than 16 services, increase the limit beyond its
8530 default value of 16. If detecting infinite iteration loops sooner
8531 is critical, make the iteration limit match the actual number
8532 of services in your longest adaptation set or chain.
8534 Infinite adaptation loops are most likely with routing services.
8536 See also: icap_service routing=1
8539 NAME: adaptation_masterx_shared_names
8541 IFDEF: USE_ADAPTATION
8542 LOC: Adaptation::Config::masterx_shared_name
8545 For each master transaction (i.e., the HTTP request and response
8546 sequence, including all related ICAP and eCAP exchanges), Squid
8547 maintains a table of metadata. The table entries are (name, value)
8548 pairs shared among eCAP and ICAP exchanges. The table is destroyed
8549 with the master transaction.
8551 This option specifies the table entry names that Squid must accept
8552 from and forward to the adaptation transactions.
8554 An ICAP REQMOD or RESPMOD transaction may set an entry in the
8555 shared table by returning an ICAP header field with a name
8556 specified in adaptation_masterx_shared_names.
8558 An eCAP REQMOD or RESPMOD transaction may set an entry in the
8559 shared table by implementing the libecap::visitEachOption() API
8560 to provide an option with a name specified in
8561 adaptation_masterx_shared_names.
8563 Squid will store and forward the set entry to subsequent adaptation
8564 transactions within the same master transaction scope.
8566 Only one shared entry name is supported at this time.
8569 # share authentication information among ICAP services
8570 adaptation_masterx_shared_names X-Subscriber-ID
8573 NAME: adaptation_meta
8575 IFDEF: USE_ADAPTATION
8576 LOC: Adaptation::Config::metaHeaders
8579 This option allows Squid administrator to add custom ICAP request
8580 headers or eCAP options to Squid ICAP requests or eCAP transactions.
8581 Use it to pass custom authentication tokens and other
8582 transaction-state related meta information to an ICAP/eCAP service.
8584 The addition of a meta header is ACL-driven:
8585 adaptation_meta name value [!]aclname ...
8587 Processing for a given header name stops after the first ACL list match.
8588 Thus, it is impossible to add two headers with the same name. If no ACL
8589 lists match for a given header name, no such header is added. For
8592 # do not debug transactions except for those that need debugging
8593 adaptation_meta X-Debug 1 needs_debugging
8595 # log all transactions except for those that must remain secret
8596 adaptation_meta X-Log 1 !keep_secret
8598 # mark transactions from users in the "G 1" group
8599 adaptation_meta X-Authenticated-Groups "G 1" authed_as_G1
8601 The "value" parameter may be a regular squid.conf token or a "double
8602 quoted string". Within the quoted string, use backslash (\) to escape
8603 any character, which is currently only useful for escaping backslashes
8604 and double quotes. For example,
8605 "this string has one backslash (\\) and two \"quotes\""
8607 Used adaptation_meta header values may be logged via %note
8608 logformat code. If multiple adaptation_meta headers with the same name
8609 are used during master transaction lifetime, the header values are
8610 logged in the order they were used and duplicate values are ignored
8611 (only the first repeated value will be logged).
8617 LOC: Adaptation::Icap::TheConfig.repeat
8618 DEFAULT_IF_NONE: deny all
8620 This ACL determines which retriable ICAP transactions are
8621 retried. Transactions that received a complete ICAP response
8622 and did not have to consume or produce HTTP bodies to receive
8623 that response are usually retriable.
8625 icap_retry allow|deny [!]aclname ...
8627 Squid automatically retries some ICAP I/O timeouts and errors
8628 due to persistent connection race conditions.
8630 See also: icap_retry_limit
8633 NAME: icap_retry_limit
8636 LOC: Adaptation::Icap::TheConfig.repeat_limit
8638 DEFAULT_DOC: No retries are allowed.
8640 Limits the number of retries allowed.
8642 Communication errors due to persistent connection race
8643 conditions are unavoidable, automatically retried, and do not
8644 count against this limit.
8646 See also: icap_retry
8652 -----------------------------------------------------------------------------
8655 NAME: check_hostnames
8658 LOC: Config.onoff.check_hostnames
8660 For security and stability reasons Squid can check
8661 hostnames for Internet standard RFC compliance. If you want
8662 Squid to perform these checks turn this directive on.
8665 NAME: allow_underscore
8668 LOC: Config.onoff.allow_underscore
8670 Underscore characters is not strictly allowed in Internet hostnames
8671 but nevertheless used by many sites. Set this to off if you want
8672 Squid to be strict about the standard.
8673 This check is performed only when check_hostnames is set to on.
8676 NAME: dns_retransmit_interval
8679 LOC: Config.Timeout.idns_retransmit
8681 Initial retransmit interval for DNS queries. The interval is
8682 doubled each time all configured DNS servers have been tried.
8688 LOC: Config.Timeout.idns_query
8690 DNS Query timeout. If no response is received to a DNS query
8691 within this time all DNS servers for the queried domain
8692 are assumed to be unavailable.
8695 NAME: dns_packet_max
8697 DEFAULT_DOC: EDNS disabled
8699 LOC: Config.dns.packet_max
8701 Maximum number of bytes packet size to advertise via EDNS.
8702 Set to "none" to disable EDNS large packet support.
8704 For legacy reasons DNS UDP replies will default to 512 bytes which
8705 is too small for many responses. EDNS provides a means for Squid to
8706 negotiate receiving larger responses back immediately without having
8707 to failover with repeat requests. Responses larger than this limit
8708 will retain the old behaviour of failover to TCP DNS.
8710 Squid has no real fixed limit internally, but allowing packet sizes
8711 over 1500 bytes requires network jumbogram support and is usually not
8714 WARNING: The RFC also indicates that some older resolvers will reply
8715 with failure of the whole request if the extension is added. Some
8716 resolvers have already been identified which will reply with mangled
8717 EDNS response on occasion. Usually in response to many-KB jumbogram
8718 sizes being advertised by Squid.
8719 Squid will currently treat these both as an unable-to-resolve domain
8720 even if it would be resolvable without EDNS.
8727 DEFAULT_DOC: Search for single-label domain names is disabled.
8728 LOC: Config.onoff.res_defnames
8730 Normally the RES_DEFNAMES resolver option is disabled
8731 (see res_init(3)). This prevents caches in a hierarchy
8732 from interpreting single-component hostnames locally. To allow
8733 Squid to handle single-component names, enable this option.
8736 NAME: dns_multicast_local
8740 DEFAULT_DOC: Search for .local and .arpa names is disabled.
8741 LOC: Config.onoff.dns_mdns
8743 When set to on, Squid sends multicast DNS lookups on the local
8744 network for domains ending in .local and .arpa.
8745 This enables local servers and devices to be contacted in an
8746 ad-hoc or zero-configuration network environment.
8749 NAME: dns_nameservers
8752 DEFAULT_DOC: Use operating system definitions
8753 LOC: Config.dns_nameservers
8755 Use this if you want to specify a list of DNS name servers
8756 (IP addresses) to use instead of those given in your
8757 /etc/resolv.conf file.
8759 On Windows platforms, if no value is specified here or in
8760 the /etc/resolv.conf file, the list of DNS name servers are
8761 taken from the Windows registry, both static and dynamic DHCP
8762 configurations are supported.
8764 Example: dns_nameservers 10.0.0.1 192.172.0.4
8769 DEFAULT: @DEFAULT_HOSTS@
8770 LOC: Config.etcHostsPath
8772 Location of the host-local IP name-address associations
8773 database. Most Operating Systems have such a file on different
8775 - Un*X & Linux: /etc/hosts
8776 - Windows NT/2000: %SystemRoot%\system32\drivers\etc\hosts
8777 (%SystemRoot% value install default is c:\winnt)
8778 - Windows XP/2003: %SystemRoot%\system32\drivers\etc\hosts
8779 (%SystemRoot% value install default is c:\windows)
8780 - Windows 9x/Me: %windir%\hosts
8781 (%windir% value is usually c:\windows)
8782 - Cygwin: /etc/hosts
8784 The file contains newline-separated definitions, in the
8785 form ip_address_in_dotted_form name [name ...] names are
8786 whitespace-separated. Lines beginning with an hash (#)
8787 character are comments.
8789 The file is checked at startup and upon configuration.
8790 If set to 'none', it won't be checked.
8791 If append_domain is used, that domain will be added to
8792 domain-local (i.e. not containing any dot character) host
8798 LOC: Config.appendDomain
8800 DEFAULT_DOC: Use operating system definitions
8802 Appends local domain name to hostnames without any dots in
8803 them. append_domain must begin with a period.
8805 Be warned there are now Internet names with no dots in
8806 them using only top-domain names, so setting this may
8807 cause some Internet sites to become unavailable.
8810 append_domain .yourdomain.com
8813 NAME: ignore_unknown_nameservers
8815 LOC: Config.onoff.ignore_unknown_nameservers
8818 By default Squid checks that DNS responses are received
8819 from the same IP addresses they are sent to. If they
8820 don't match, Squid ignores the response and writes a warning
8821 message to cache.log. You can allow responses from unknown
8822 nameservers by setting this option to 'off'.
8828 LOC: Config.dns.v4_first
8830 With the IPv6 Internet being as fast or faster than IPv4 Internet
8831 for most networks Squid prefers to contact websites over IPv6.
8833 This option reverses the order of preference to make Squid contact
8834 dual-stack websites over IPv4 first. Squid will still perform both
8835 IPv6 and IPv4 DNS lookups before connecting.
8838 This option will restrict the situations under which IPv6
8839 connectivity is used (and tested). Hiding network problems
8840 which would otherwise be detected and warned about.
8844 COMMENT: (number of entries)
8847 LOC: Config.ipcache.size
8849 Maximum number of DNS IP cache entries.
8856 LOC: Config.ipcache.low
8863 LOC: Config.ipcache.high
8865 The size, low-, and high-water marks for the IP cache.
8868 NAME: fqdncache_size
8869 COMMENT: (number of entries)
8872 LOC: Config.fqdncache.size
8874 Maximum number of FQDN cache entries.
8879 -----------------------------------------------------------------------------
8882 NAME: configuration_includes_quoted_values
8884 TYPE: configuration_includes_quoted_values
8886 LOC: ConfigParser::RecognizeQuotedValues
8888 If set, Squid will recognize each "quoted string" after a configuration
8889 directive as a single parameter. The quotes are stripped before the
8890 parameter value is interpreted or used.
8891 See "Values with spaces, quotes, and other special characters"
8892 section for more details.
8899 LOC: Config.onoff.mem_pools
8901 If set, Squid will keep pools of allocated (but unused) memory
8902 available for future use. If memory is a premium on your
8903 system and you believe your malloc library outperforms Squid
8904 routines, disable this.
8907 NAME: memory_pools_limit
8911 LOC: Config.MemPools.limit
8913 Used only with memory_pools on:
8914 memory_pools_limit 50 MB
8916 If set to a non-zero value, Squid will keep at most the specified
8917 limit of allocated (but unused) memory in memory pools. All free()
8918 requests that exceed this limit will be handled by your malloc
8919 library. Squid does not pre-allocate any memory, just safe-keeps
8920 objects that otherwise would be free()d. Thus, it is safe to set
8921 memory_pools_limit to a reasonably high value even if your
8922 configuration will use less memory.
8924 If set to none, Squid will keep all memory it can. That is, there
8925 will be no limit on the total amount of memory used for safe-keeping.
8927 To disable memory allocation optimization, do not set
8928 memory_pools_limit to 0 or none. Set memory_pools to "off" instead.
8930 An overhead for maintaining memory pools is not taken into account
8931 when the limit is checked. This overhead is close to four bytes per
8932 object kept. However, pools may actually _save_ memory because of
8933 reduced memory thrashing in your malloc library.
8937 COMMENT: on|off|transparent|truncate|delete
8940 LOC: opt_forwarded_for
8942 If set to "on", Squid will append your client's IP address
8943 in the HTTP requests it forwards. By default it looks like:
8945 X-Forwarded-For: 192.1.2.3
8947 If set to "off", it will appear as
8949 X-Forwarded-For: unknown
8951 If set to "transparent", Squid will not alter the
8952 X-Forwarded-For header in any way.
8954 If set to "delete", Squid will delete the entire
8955 X-Forwarded-For header.
8957 If set to "truncate", Squid will remove all existing
8958 X-Forwarded-For entries, and place the client IP as the sole entry.
8961 NAME: cachemgr_passwd
8962 TYPE: cachemgrpasswd
8964 DEFAULT_DOC: No password. Actions which require password are denied.
8965 LOC: Config.passwd_list
8967 Specify passwords for cachemgr operations.
8969 Usage: cachemgr_passwd password action action ...
8971 Some valid actions are (see cache manager menu for a full list):
9011 * Indicates actions which will not be performed without a
9012 valid password, others can be performed if not listed here.
9014 To disable an action, set the password to "disable".
9015 To allow performing an action without a password, set the
9018 Use the keyword "all" to set the same password for all actions.
9021 cachemgr_passwd secret shutdown
9022 cachemgr_passwd lesssssssecret info stats/objects
9023 cachemgr_passwd disable all
9030 LOC: Config.onoff.client_db
9032 If you want to disable collecting per-client statistics,
9033 turn off client_db here.
9036 NAME: refresh_all_ims
9040 LOC: Config.onoff.refresh_all_ims
9042 When you enable this option, squid will always check
9043 the origin server for an update when a client sends an
9044 If-Modified-Since request. Many browsers use IMS
9045 requests when the user requests a reload, and this
9046 ensures those clients receive the latest version.
9048 By default (off), squid may return a Not Modified response
9049 based on the age of the cached version.
9052 NAME: reload_into_ims
9053 IFDEF: USE_HTTP_VIOLATIONS
9057 LOC: Config.onoff.reload_into_ims
9059 When you enable this option, client no-cache or ``reload''
9060 requests will be changed to If-Modified-Since requests.
9061 Doing this VIOLATES the HTTP standard. Enabling this
9062 feature could make you liable for problems which it
9065 see also refresh_pattern for a more selective approach.
9068 NAME: connect_retries
9070 LOC: Config.connect_retries
9072 DEFAULT_DOC: Do not retry failed connections.
9074 This sets the maximum number of connection attempts made for each
9075 TCP connection. The connect_retries attempts must all still
9076 complete within the connection timeout period.
9078 The default is not to re-try if the first connection attempt fails.
9079 The (not recommended) maximum is 10 tries.
9081 A warning message will be generated if it is set to a too-high
9082 value and the configured value will be over-ridden.
9084 Note: These re-tries are in addition to forward_max_tries
9085 which limit how many different addresses may be tried to find
9089 NAME: retry_on_error
9091 LOC: Config.retry.onerror
9094 If set to ON Squid will automatically retry requests when
9095 receiving an error response with status 403 (Forbidden),
9096 500 (Internal Error), 501 or 503 (Service not available).
9097 Status 502 and 504 (Gateway errors) are always retried.
9099 This is mainly useful if you are in a complex cache hierarchy to
9100 work around access control errors.
9102 NOTE: This retry will attempt to find another working destination.
9103 Which is different from the server which just failed.
9106 NAME: as_whois_server
9108 LOC: Config.as_whois_server
9109 DEFAULT: whois.ra.net
9111 WHOIS server to query for AS numbers. NOTE: AS numbers are
9112 queried only when Squid starts up, not for every request.
9117 LOC: Config.onoff.offline
9120 Enable this option and Squid will never try to validate cached
9124 NAME: uri_whitespace
9125 TYPE: uri_whitespace
9126 LOC: Config.uri_whitespace
9129 What to do with requests that have whitespace characters in the
9132 strip: The whitespace characters are stripped out of the URL.
9133 This is the behavior recommended by RFC2396 and RFC3986
9134 for tolerant handling of generic URI.
9135 NOTE: This is one difference between generic URI and HTTP URLs.
9137 deny: The request is denied. The user receives an "Invalid
9139 This is the behaviour recommended by RFC2616 for safe
9140 handling of HTTP request URL.
9142 allow: The request is allowed and the URI is not changed. The
9143 whitespace characters remain in the URI. Note the
9144 whitespace is passed to redirector processes if they
9146 Note this may be considered a violation of RFC2616
9147 request parsing where whitespace is prohibited in the
9150 encode: The request is allowed and the whitespace characters are
9151 encoded according to RFC1738.
9153 chop: The request is allowed and the URI is chopped at the
9157 NOTE the current Squid implementation of encode and chop violates
9158 RFC2616 by not using a 301 redirect after altering the URL.
9163 LOC: Config.chroot_dir
9166 Specifies a directory where Squid should do a chroot() while
9167 initializing. This also causes Squid to fully drop root
9168 privileges after initializing. This means, for example, if you
9169 use a HTTP port less than 1024 and try to reconfigure, you may
9170 get an error saying that Squid can not open the port.
9173 NAME: balance_on_multiple_ip
9175 LOC: Config.onoff.balance_on_multiple_ip
9178 Modern IP resolvers in squid sort lookup results by preferred access.
9179 By default squid will use these IP in order and only rotates to
9180 the next listed when the most preffered fails.
9182 Some load balancing servers based on round robin DNS have been
9183 found not to preserve user session state across requests
9184 to different IP addresses.
9186 Enabling this directive Squid rotates IP's per request.
9189 NAME: pipeline_prefetch
9190 TYPE: pipelinePrefetch
9191 LOC: Config.pipeline_max_prefetch
9193 DEFAULT_DOC: Do not pre-parse pipelined requests.
9195 HTTP clients may send a pipeline of 1+N requests to Squid using a
9196 single connection, without waiting for Squid to respond to the first
9197 of those requests. This option limits the number of concurrent
9198 requests Squid will try to handle in parallel. If set to N, Squid
9199 will try to receive and process up to 1+N requests on the same
9200 connection concurrently.
9202 Defaults to 0 (off) for bandwidth management and access logging
9205 NOTE: pipelining requires persistent connections to clients.
9207 WARNING: pipelining breaks NTLM and Negotiate/Kerberos authentication.
9210 NAME: high_response_time_warning
9213 LOC: Config.warnings.high_rptm
9215 DEFAULT_DOC: disabled.
9217 If the one-minute median response time exceeds this value,
9218 Squid prints a WARNING with debug level 0 to get the
9219 administrators attention. The value is in milliseconds.
9222 NAME: high_page_fault_warning
9224 LOC: Config.warnings.high_pf
9226 DEFAULT_DOC: disabled.
9228 If the one-minute average page fault rate exceeds this
9229 value, Squid prints a WARNING with debug level 0 to get
9230 the administrators attention. The value is in page faults
9234 NAME: high_memory_warning
9236 LOC: Config.warnings.high_memory
9237 IFDEF: HAVE_MSTATS&&HAVE_GNUMALLOC_H
9239 DEFAULT_DOC: disabled.
9241 If the memory usage (as determined by gnumalloc, if available and used)
9242 exceeds this amount, Squid prints a WARNING with debug level 0 to get
9243 the administrators attention.
9245 # TODO: link high_memory_warning to mempools?
9247 NAME: sleep_after_fork
9248 COMMENT: (microseconds)
9250 LOC: Config.sleep_after_fork
9253 When this is set to a non-zero value, the main Squid process
9254 sleeps the specified number of microseconds after a fork()
9255 system call. This sleep may help the situation where your
9256 system reports fork() failures due to lack of (virtual)
9257 memory. Note, however, if you have a lot of child
9258 processes, these sleep delays will add up and your
9259 Squid will not service requests for some amount of time
9260 until all the child processes have been started.
9261 On Windows value less then 1000 (1 milliseconds) are
9265 NAME: windows_ipaddrchangemonitor
9266 IFDEF: _SQUID_WINDOWS_
9270 LOC: Config.onoff.WIN32_IpAddrChangeMonitor
9272 On Windows Squid by default will monitor IP address changes and will
9273 reconfigure itself after any detected event. This is very useful for
9274 proxies connected to internet with dial-up interfaces.
9275 In some cases (a Proxy server acting as VPN gateway is one) it could be
9276 desiderable to disable this behaviour setting this to 'off'.
9277 Note: after changing this, Squid service must be restarted.
9282 IFDEF: USE_SQUID_EUI
9284 LOC: Eui::TheConfig.euiLookup
9286 Whether to lookup the EUI or MAC address of a connected client.
9289 NAME: max_filedescriptors max_filedesc
9292 DEFAULT_DOC: Use operating system limits set by ulimit.
9293 LOC: Config.max_filedescriptors
9295 Reduce the maximum number of filedescriptors supported below
9296 the usual operating system defaults.
9298 Remove from squid.conf to inherit the current ulimit setting.
9300 Note: Changing this requires a restart of Squid. Also
9301 not all I/O types supports large values (eg on Windows).
9308 DEFAULT_DOC: SMP support disabled.
9310 Number of main Squid processes or "workers" to fork and maintain.
9311 0: "no daemon" mode, like running "squid -N ..."
9312 1: "no SMP" mode, start one main Squid process daemon (default)
9313 N: start N main Squid process daemons (i.e., SMP mode)
9315 In SMP mode, each worker does nearly all what a single Squid daemon
9316 does (e.g., listen on http_port and forward HTTP requests).
9319 NAME: cpu_affinity_map
9320 TYPE: CpuAffinityMap
9321 LOC: Config.cpuAffinityMap
9323 DEFAULT_DOC: Let operating system decide.
9325 Usage: cpu_affinity_map process_numbers=P1,P2,... cores=C1,C2,...
9327 Sets 1:1 mapping between Squid processes and CPU cores. For example,
9329 cpu_affinity_map process_numbers=1,2,3,4 cores=1,3,5,7
9331 affects processes 1 through 4 only and places them on the first
9332 four even cores, starting with core #1.
9334 CPU cores are numbered starting from 1. Requires support for
9335 sched_getaffinity(2) and sched_setaffinity(2) system calls.
9337 Multiple cpu_affinity_map options are merged.
9342 NAME: force_request_body_continuation
9344 LOC: Config.accessList.forceRequestBodyContinuation
9346 DEFAULT_DOC: Deny, unless rules exist in squid.conf.
9348 This option controls how Squid handles data upload requests from HTTP
9349 and FTP agents that require a "Please Continue" control message response
9350 to actually send the request body to Squid. It is mostly useful in
9351 adaptation environments.
9353 When Squid receives an HTTP request with an "Expect: 100-continue"
9354 header or an FTP upload command (e.g., STOR), Squid normally sends the
9355 request headers or FTP command information to an adaptation service (or
9356 peer) and waits for a response. Most adaptation services (and some
9357 broken peers) may not respond to Squid at that stage because they may
9358 decide to wait for the HTTP request body or FTP data transfer. However,
9359 that request body or data transfer may never come because Squid has not
9360 responded with the HTTP 100 or FTP 150 (Please Continue) control message
9361 to the request sender yet!
9363 An allow match tells Squid to respond with the HTTP 100 or FTP 150
9364 (Please Continue) control message on its own, before forwarding the
9365 request to an adaptation service or peer. Such a response usually forces
9366 the request sender to proceed with sending the body. A deny match tells
9367 Squid to delay that control response until the origin server confirms
9368 that the request body is needed. Delaying is the default behavior.
projects / thirdparty / squid.git / blob