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diff --git a/squid/squid.conf b/squid/squid.conf new file mode 100644 index 0000000..8eff0b7 --- /dev/null +++ b/squid/squid.conf @@ -0,0 +1,7960 @@ +# WELCOME TO SQUID 3.5.23 +# ---------------------------- +# +# This is the documentation for the Squid configuration file. +# This documentation can also be found online at: +# http://www.squid-cache.org/Doc/config/ +# +# You may wish to look at the Squid home page and wiki for the +# FAQ and other documentation: +# http://www.squid-cache.org/ +# http://wiki.squid-cache.org/SquidFaq +# http://wiki.squid-cache.org/ConfigExamples +# +# This documentation shows what the defaults for various directives +# happen to be. If you don't need to change the default, you should +# leave the line out of your squid.conf in most cases. +# +# In some cases "none" refers to no default setting at all, +# while in other cases it refers to the value of the option +# - the comments for that keyword indicate if this is the case. +# + +# Configuration options can be included using the "include" directive. +# Include takes a list of files to include. Quoting and wildcards are +# supported. +# +# For example, +# +# include /path/to/included/file/squid.acl.config +# +# Includes can be nested up to a hard-coded depth of 16 levels. +# This arbitrary restriction is to prevent recursive include references +# from causing Squid entering an infinite loop whilst trying to load +# configuration files. +# +# Values with byte units +# +# Squid accepts size units on some size related directives. All +# such directives are documented with a default value displaying +# a unit. +# +# Units accepted by Squid are: +# bytes - byte +# KB - Kilobyte (1024 bytes) +# MB - Megabyte +# GB - Gigabyte +# +# Values with spaces, quotes, and other special characters +# +# Squid supports directive parameters with spaces, quotes, and other +# special characters. Surround such parameters with "double quotes". Use +# the configuration_includes_quoted_values directive to enable or +# disable that support. +# +# Squid supports reading configuration option parameters from external +# files using the syntax: +# parameters("/path/filename") +# For example: +# acl whitelist dstdomain parameters("/etc/squid/whitelist.txt") +# +# Conditional configuration +# +# If-statements can be used to make configuration directives +# depend on conditions: +# +# if <CONDITION> +# ... regular configuration directives ... +# [else +# ... regular configuration directives ...] +# endif +# +# The else part is optional. The keywords "if", "else", and "endif" +# must be typed on their own lines, as if they were regular +# configuration directives. +# +# NOTE: An else-if condition is not supported. +# +# These individual conditions types are supported: +# +# true +# Always evaluates to true. +# false +# Always evaluates to false. +# <integer> = <integer> +# Equality comparison of two integer numbers. +# +# +# SMP-Related Macros +# +# The following SMP-related preprocessor macros can be used. +# +# ${process_name} expands to the current Squid process "name" +# (e.g., squid1, squid2, or cache1). +# +# ${process_number} expands to the current Squid process +# identifier, which is an integer number (e.g., 1, 2, 3) unique +# across all Squid processes of the current service instance. +# +# ${service_name} expands into the current Squid service instance +# name identifier which is provided by -n on the command line. +# + +# TAG: broken_vary_encoding +# This option is not yet supported by Squid-3. +#Default: +# none + +# TAG: cache_vary +# This option is not yet supported by Squid-3. +#Default: +# none + +# TAG: error_map +# This option is not yet supported by Squid-3. +#Default: +# none + +# TAG: external_refresh_check +# This option is not yet supported by Squid-3. +#Default: +# none + +# TAG: location_rewrite_program +# This option is not yet supported by Squid-3. +#Default: +# none + +# TAG: refresh_stale_hit +# This option is not yet supported by Squid-3. +#Default: +# none + +# TAG: hierarchy_stoplist +# Remove this line. Use always_direct or cache_peer_access ACLs instead if you need to prevent cache_peer use. +#Default: +# none + +# TAG: log_access +# Remove this line. Use acls with access_log directives to control access logging +#Default: +# none + +# TAG: log_icap +# Remove this line. Use acls with icap_log directives to control icap logging +#Default: +# none + +# TAG: ignore_ims_on_miss +# Remove this line. The HTTP/1.1 feature is now configured by 'cache_miss_revalidate'. +#Default: +# none + +# TAG: chunked_request_body_max_size +# Remove this line. Squid is now HTTP/1.1 compliant. +#Default: +# none + +# TAG: dns_v4_fallback +# Remove this line. Squid performs a 'Happy Eyeballs' algorithm, the 'fallback' algorithm is no longer relevant. +#Default: +# none + +# TAG: emulate_httpd_log +# Replace this with an access_log directive using the format 'common' or 'combined'. +#Default: +# none + +# TAG: forward_log +# Use a regular access.log with ACL limiting it to MISS events. +#Default: +# none + +# TAG: ftp_list_width +# Remove this line. Configure FTP page display using the CSS controls in errorpages.css instead. +#Default: +# none + +# TAG: ignore_expect_100 +# Remove this line. The HTTP/1.1 feature is now fully supported by default. +#Default: +# none + +# TAG: log_fqdn +# Remove this option from your config. To log FQDN use %>A in the log format. +#Default: +# none + +# TAG: log_ip_on_direct +# Remove this option from your config. To log server or peer names use %<A in the log format. +#Default: +# none + +# TAG: maximum_single_addr_tries +# Replaced by connect_retries. The behaviour has changed, please read the documentation before altering. +#Default: +# none + +# TAG: referer_log +# Replace this with an access_log directive using the format 'referrer'. +#Default: +# none + +# TAG: update_headers +# Remove this line. The feature is supported by default in storage types where update is implemented. +#Default: +# none + +# TAG: url_rewrite_concurrency +# Remove this line. Set the 'concurrency=' option of url_rewrite_children instead. +#Default: +# none + +# TAG: useragent_log +# Replace this with an access_log directive using the format 'useragent'. +#Default: +# none + +# TAG: dns_testnames +# Remove this line. DNS is no longer tested on startup. +#Default: +# none + +# TAG: extension_methods +# Remove this line. All valid methods for HTTP are accepted by default. +#Default: +# none + +# TAG: zero_buffers +#Default: +# none + +# TAG: incoming_rate +#Default: +# none + +# TAG: server_http11 +# Remove this line. HTTP/1.1 is supported by default. +#Default: +# none + +# TAG: upgrade_http0.9 +# Remove this line. ICY/1.0 streaming protocol is supported by default. +#Default: +# none + +# TAG: zph_local +# Alter these entries. Use the qos_flows directive instead. +#Default: +# none + +# TAG: header_access +# Since squid-3.0 replace with request_header_access or reply_header_access +# depending on whether you wish to match client requests or server replies. +#Default: +# none + +# TAG: httpd_accel_no_pmtu_disc +# Since squid-3.0 use the 'disable-pmtu-discovery' flag on http_port instead. +#Default: +# none + +# TAG: wais_relay_host +# Replace this line with 'cache_peer' configuration. +#Default: +# none + +# TAG: wais_relay_port +# Replace this line with 'cache_peer' configuration. +#Default: +# none + +# OPTIONS FOR SMP +# ----------------------------------------------------------------------------- + +# TAG: workers +# Number of main Squid processes or "workers" to fork and maintain. +# 0: "no daemon" mode, like running "squid -N ..." +# 1: "no SMP" mode, start one main Squid process daemon (default) +# N: start N main Squid process daemons (i.e., SMP mode) +# +# In SMP mode, each worker does nearly all what a single Squid daemon +# does (e.g., listen on http_port and forward HTTP requests). +#Default: +# SMP support disabled. + +# TAG: cpu_affinity_map +# Usage: cpu_affinity_map process_numbers=P1,P2,... cores=C1,C2,... +# +# Sets 1:1 mapping between Squid processes and CPU cores. For example, +# +# cpu_affinity_map process_numbers=1,2,3,4 cores=1,3,5,7 +# +# affects processes 1 through 4 only and places them on the first +# four even cores, starting with core #1. +# +# CPU cores are numbered starting from 1. Requires support for +# sched_getaffinity(2) and sched_setaffinity(2) system calls. +# +# Multiple cpu_affinity_map options are merged. +# +# See also: workers +#Default: +# Let operating system decide. + +# OPTIONS FOR AUTHENTICATION +# ----------------------------------------------------------------------------- + +# TAG: auth_param +# This is used to define parameters for the various authentication +# schemes supported by Squid. +# +# format: auth_param scheme parameter [setting] +# +# The order in which authentication schemes are presented to the client is +# dependent on the order the scheme first appears in config file. IE +# has a bug (it's not RFC 2617 compliant) in that it will use the basic +# scheme if basic is the first entry presented, even if more secure +# schemes are presented. For now use the order in the recommended +# settings section below. If other browsers have difficulties (don't +# recognize the schemes offered even if you are using basic) either +# put basic first, or disable the other schemes (by commenting out their +# program entry). +# +# Once an authentication scheme is fully configured, it can only be +# shutdown by shutting squid down and restarting. Changes can be made on +# the fly and activated with a reconfigure. I.E. You can change to a +# different helper, but not unconfigure the helper completely. +# +# Please note that while this directive defines how Squid processes +# authentication it does not automatically activate authentication. +# To use authentication you must in addition make use of ACLs based +# on login name in http_access (proxy_auth, proxy_auth_regex or +# external with %LOGIN used in the format tag). The browser will be +# challenged for authentication on the first such acl encountered +# in http_access processing and will also be re-challenged for new +# login credentials if the request is being denied by a proxy_auth +# type acl. +# +# WARNING: authentication can't be used in a transparently intercepting +# proxy as the client then thinks it is talking to an origin server and +# not the proxy. This is a limitation of bending the TCP/IP protocol to +# transparently intercepting port 80, not a limitation in Squid. +# Ports flagged 'transparent', 'intercept', or 'tproxy' have +# authentication disabled. +# +# === Parameters common to all schemes. === +# +# "program" cmdline +# Specifies the command for the external authenticator. +# +# By default, each authentication scheme is not used unless a +# program is specified. +# +# See http://wiki.squid-cache.org/Features/AddonHelpers for +# more details on helper operations and creating your own. +# +# "key_extras" format +# Specifies a string to be append to request line format for +# the authentication helper. "Quoted" format values may contain +# spaces and logformat %macros. In theory, any logformat %macro +# can be used. In practice, a %macro expands as a dash (-) if +# the helper request is sent before the required macro +# information is available to Squid. +# +# By default, Squid uses request formats provided in +# scheme-specific examples below (search for %credentials). +# +# The expanded key_extras value is added to the Squid credentials +# cache and, hence, will affect authentication. It can be used to +# autenticate different users with identical user names (e.g., +# when user authentication depends on http_port). +# +# Avoid adding frequently changing information to key_extras. For +# example, if you add user source IP, and it changes frequently +# in your environment, then max_user_ip ACL is going to treat +# every user+IP combination as a unique "user", breaking the ACL +# and wasting a lot of memory on those user records. It will also +# force users to authenticate from scratch whenever their IP +# changes. +# +# "realm" string +# Specifies the protection scope (aka realm name) which is to be +# reported to the client for the authentication scheme. It is +# commonly part of the text the user will see when prompted for +# their username and password. +# +# For Basic the default is "Squid proxy-caching web server". +# For Digest there is no default, this parameter is mandatory. +# For NTLM and Negotiate this parameter is ignored. +# +# "children" numberofchildren [startup=N] [idle=N] [concurrency=N] +# +# The maximum number of authenticator processes to spawn. If +# you start too few Squid will have to wait for them to process +# a backlog of credential verifications, slowing it down. When +# password verifications are done via a (slow) network you are +# likely to need lots of authenticator processes. +# +# The startup= and idle= options permit some skew in the exact +# amount run. A minimum of startup=N will begin during startup +# and reconfigure. Squid will start more in groups of up to +# idle=N in an attempt to meet traffic needs and to keep idle=N +# free above those traffic needs up to the maximum. +# +# The concurrency= option sets the number of concurrent requests +# the helper can process. The default of 0 is used for helpers +# who only supports one request at a time. Setting this to a +# number greater than 0 changes the protocol used to include a +# channel ID field first on the request/response line, allowing +# multiple requests to be sent to the same helper in parallel +# without waiting for the response. +# +# Concurrency must not be set unless it's known the helper +# supports the input format with channel-ID fields. +# +# NOTE: NTLM and Negotiate schemes do not support concurrency +# in the Squid code module even though some helpers can. +# +# +# +# === Example Configuration === +# +# This configuration displays the recommended authentication scheme +# order from most to least secure with recommended minimum configuration +# settings for each scheme: +# +##auth_param negotiate program <uncomment and complete this line to activate> +##auth_param negotiate children 20 startup=0 idle=1 +##auth_param negotiate keep_alive on +## +##auth_param digest program <uncomment and complete this line to activate> +##auth_param digest children 20 startup=0 idle=1 +##auth_param digest realm Squid proxy-caching web server +##auth_param digest nonce_garbage_interval 5 minutes +##auth_param digest nonce_max_duration 30 minutes +##auth_param digest nonce_max_count 50 +## +##auth_param ntlm program <uncomment and complete this line to activate> +##auth_param ntlm children 20 startup=0 idle=1 +##auth_param ntlm keep_alive on +## +##auth_param basic program <uncomment and complete this line> +##auth_param basic children 5 startup=5 idle=1 +##auth_param basic realm Squid proxy-caching web server +##auth_param basic credentialsttl 2 hours +#Default: +# none + +# TAG: authenticate_cache_garbage_interval +# The time period between garbage collection across the username cache. +# This is a trade-off between memory utilization (long intervals - say +# 2 days) and CPU (short intervals - say 1 minute). Only change if you +# have good reason to. +#Default: +# authenticate_cache_garbage_interval 1 hour + +# TAG: authenticate_ttl +# The time a user & their credentials stay in the logged in +# user cache since their last request. When the garbage +# interval passes, all user credentials that have passed their +# TTL are removed from memory. +#Default: +# authenticate_ttl 1 hour + +# TAG: authenticate_ip_ttl +# If you use proxy authentication and the 'max_user_ip' ACL, +# this directive controls how long Squid remembers the IP +# addresses associated with each user. Use a small value +# (e.g., 60 seconds) if your users might change addresses +# quickly, as is the case with dialup. You might be safe +# using a larger value (e.g., 2 hours) in a corporate LAN +# environment with relatively static address assignments. +#Default: +# authenticate_ip_ttl 1 second + +# ACCESS CONTROLS +# ----------------------------------------------------------------------------- + +# TAG: external_acl_type +# This option defines external acl classes using a helper program +# to look up the status +# +# external_acl_type name [options] FORMAT.. /path/to/helper [helper arguments..] +# +# Options: +# +# ttl=n TTL in seconds for cached results (defaults to 3600 +# for 1 hour) +# +# negative_ttl=n +# TTL for cached negative lookups (default same +# as ttl) +# +# grace=n Percentage remaining of TTL where a refresh of a +# cached entry should be initiated without needing to +# wait for a new reply. (default is for no grace period) +# +# cache=n The maximum number of entries in the result cache. The +# default limit is 262144 entries. Each cache entry usually +# consumes at least 256 bytes. Squid currently does not remove +# expired cache entries until the limit is reached, so a proxy +# will sooner or later reach the limit. The expanded FORMAT +# value is used as the cache key, so if the details in FORMAT +# are highly variable, a larger cache may be needed to produce +# reduction in helper load. +# +# children-max=n +# Maximum number of acl helper processes spawned to service +# external acl lookups of this type. (default 5) +# +# children-startup=n +# Minimum number of acl helper processes to spawn during +# startup and reconfigure to service external acl lookups +# of this type. (default 0) +# +# children-idle=n +# Number of acl helper processes to keep ahead of traffic +# loads. Squid will spawn this many at once whenever load +# rises above the capabilities of existing processes. +# Up to the value of children-max. (default 1) +# +# concurrency=n concurrency level per process. Only used with helpers +# capable of processing more than one query at a time. +# +# protocol=2.5 Compatibility mode for Squid-2.5 external acl helpers. +# +# ipv4 / ipv6 IP protocol used to communicate with this helper. +# The default is to auto-detect IPv6 and use it when available. +# +# +# FORMAT specifications +# +# %LOGIN Authenticated user login name +# %un A user name. Expands to the first available name +# from the following list of information sources: +# - authenticated user name, like %ul or %LOGIN +# - user name sent by an external ACL, like %EXT_USER +# - SSL client name, like %us in logformat +# - ident user name, like %ui in logformat +# %EXT_USER Username from previous external acl +# %EXT_LOG Log details from previous external acl +# %EXT_TAG Tag from previous external acl +# %IDENT Ident user name +# %SRC Client IP +# %SRCPORT Client source port +# %URI Requested URI +# %DST Requested host +# %PROTO Requested URL scheme +# %PORT Requested port +# %PATH Requested URL path +# %METHOD Request method +# %MYADDR Squid interface address +# %MYPORT Squid http_port number +# %PATH Requested URL-path (including query-string if any) +# %USER_CERT SSL User certificate in PEM format +# %USER_CERTCHAIN SSL User certificate chain in PEM format +# %USER_CERT_xx SSL User certificate subject attribute xx +# %USER_CA_CERT_xx SSL User certificate issuer attribute xx +# %ssl::>sni SSL client SNI sent to Squid +# %ssl::<cert_subject SSL server certificate DN +# %ssl::<cert_issuer SSL server certificate issuer DN +# +# %>{Header} HTTP request header "Header" +# %>{Hdr:member} +# HTTP request header "Hdr" list member "member" +# %>{Hdr:;member} +# HTTP request header list member using ; as +# list separator. ; can be any non-alphanumeric +# character. +# +# %<{Header} HTTP reply header "Header" +# %<{Hdr:member} +# HTTP reply header "Hdr" list member "member" +# %<{Hdr:;member} +# HTTP reply header list member using ; as +# list separator. ; can be any non-alphanumeric +# character. +# +# %ACL The name of the ACL being tested. +# %DATA The ACL arguments. If not used then any arguments +# is automatically added at the end of the line +# sent to the helper. +# NOTE: this will encode the arguments as one token, +# whereas the default will pass each separately. +# +# %% The percent sign. Useful for helpers which need +# an unchanging input format. +# +# +# General request syntax: +# +# [channel-ID] FORMAT-values [acl-values ...] +# +# +# FORMAT-values consists of transaction details expanded with +# whitespace separation per the config file FORMAT specification +# using the FORMAT macros listed above. +# +# acl-values consists of any string specified in the referencing +# config 'acl ... external' line. see the "acl external" directive. +# +# Request values sent to the helper are URL escaped to protect +# each value in requests against whitespaces. +# +# If using protocol=2.5 then the request sent to the helper is not +# URL escaped to protect against whitespace. +# +# NOTE: protocol=3.0 is deprecated as no longer necessary. +# +# When using the concurrency= option the protocol is changed by +# introducing a query channel tag in front of the request/response. +# The query channel tag is a number between 0 and concurrency-1. +# This value must be echoed back unchanged to Squid as the first part +# of the response relating to its request. +# +# +# The helper receives lines expanded per the above format specification +# and for each input line returns 1 line starting with OK/ERR/BH result +# code and optionally followed by additional keywords with more details. +# +# +# General result syntax: +# +# [channel-ID] result keyword=value ... +# +# Result consists of one of the codes: +# +# OK +# the ACL test produced a match. +# +# ERR +# the ACL test does not produce a match. +# +# BH +# An internal error occurred in the helper, preventing +# a result being identified. +# +# The meaning of 'a match' is determined by your squid.conf +# access control configuration. See the Squid wiki for details. +# +# Defined keywords: +# +# user= The users name (login) +# +# password= The users password (for login= cache_peer option) +# +# message= Message describing the reason for this response. +# Available as %o in error pages. +# Useful on (ERR and BH results). +# +# tag= Apply a tag to a request. Only sets a tag once, +# does not alter existing tags. +# +# log= String to be logged in access.log. Available as +# %ea in logformat specifications. +# +# clt_conn_tag= Associates a TAG with the client TCP connection. +# Please see url_rewrite_program related documentation +# for this kv-pair. +# +# Any keywords may be sent on any response whether OK, ERR or BH. +# +# All response keyword values need to be a single token with URL +# escaping, or enclosed in double quotes (") and escaped using \ on +# any double quotes or \ characters within the value. The wrapping +# double quotes are removed before the value is interpreted by Squid. +# \r and \n are also replace by CR and LF. +# +# Some example key values: +# +# user=John%20Smith +# user="John Smith" +# user="J. \"Bob\" Smith" +#Default: +# none + +# TAG: acl +# Defining an Access List +# +# Every access list definition must begin with an aclname and acltype, +# followed by either type-specific arguments or a quoted filename that +# they are read from. +# +# acl aclname acltype argument ... +# acl aclname acltype "file" ... +# +# When using "file", the file should contain one item per line. +# +# Some acl types supports options which changes their default behaviour. +# The available options are: +# +# -i,+i By default, regular expressions are CASE-SENSITIVE. To make them +# case-insensitive, use the -i option. To return case-sensitive +# use the +i option between patterns, or make a new ACL line +# without -i. +# +# -n Disable lookups and address type conversions. If lookup or +# conversion is required because the parameter type (IP or +# domain name) does not match the message address type (domain +# name or IP), then the ACL would immediately declare a mismatch +# without any warnings or lookups. +# +# -- Used to stop processing all options, in the case the first acl +# value has '-' character as first character (for example the '-' +# is a valid domain name) +# +# Some acl types require suspending the current request in order +# to access some external data source. +# Those which do are marked with the tag [slow], those which +# don't are marked as [fast]. +# See http://wiki.squid-cache.org/SquidFaq/SquidAcl +# for further information +# +# ***** ACL TYPES AVAILABLE ***** +# +# acl aclname src ip-address/mask ... # clients IP address [fast] +# acl aclname src addr1-addr2/mask ... # range of addresses [fast] +# acl aclname dst [-n] ip-address/mask ... # URL host's IP address [slow] +# acl aclname localip ip-address/mask ... # IP address the client connected to [fast] +# +# acl aclname arp mac-address ... (xx:xx:xx:xx:xx:xx notation) +# # [fast] +# # The 'arp' ACL code is not portable to all operating systems. +# # It works on Linux, Solaris, Windows, FreeBSD, and some other +# # BSD variants. +# # +# # NOTE: Squid can only determine the MAC/EUI address for IPv4 +# # clients that are on the same subnet. If the client is on a +# # different subnet, then Squid cannot find out its address. +# # +# # NOTE 2: IPv6 protocol does not contain ARP. MAC/EUI is either +# # encoded directly in the IPv6 address or not available. +# +# acl aclname srcdomain .foo.com ... +# # reverse lookup, from client IP [slow] +# acl aclname dstdomain [-n] .foo.com ... +# # Destination server from URL [fast] +# acl aclname srcdom_regex [-i] \.foo\.com ... +# # regex matching client name [slow] +# acl aclname dstdom_regex [-n] [-i] \.foo\.com ... +# # regex matching server [fast] +# # +# # For dstdomain and dstdom_regex a reverse lookup is tried if a IP +# # based URL is used and no match is found. The name "none" is used +# # if the reverse lookup fails. +# +# acl aclname src_as number ... +# acl aclname dst_as number ... +# # [fast] +# # Except for access control, AS numbers can be used for +# # routing of requests to specific caches. Here's an +# # example for routing all requests for AS#1241 and only +# # those to mycache.mydomain.net: +# # acl asexample dst_as 1241 +# # cache_peer_access mycache.mydomain.net allow asexample +# # cache_peer_access mycache_mydomain.net deny all +# +# acl aclname peername myPeer ... +# # [fast] +# # match against a named cache_peer entry +# # set unique name= on cache_peer lines for reliable use. +# +# acl aclname time [day-abbrevs] [h1:m1-h2:m2] +# # [fast] +# # day-abbrevs: +# # S - Sunday +# # M - Monday +# # T - Tuesday +# # W - Wednesday +# # H - Thursday +# # F - Friday +# # A - Saturday +# # h1:m1 must be less than h2:m2 +# +# acl aclname url_regex [-i] ^http:// ... +# # regex matching on whole URL [fast] +# acl aclname urllogin [-i] [^a-zA-Z0-9] ... +# # regex matching on URL login field +# acl aclname urlpath_regex [-i] \.gif$ ... +# # regex matching on URL path [fast] +# +# acl aclname port 80 70 21 0-1024... # destination TCP port [fast] +# # ranges are alloed +# acl aclname localport 3128 ... # TCP port the client connected to [fast] +# # NP: for interception mode this is usually '80' +# +# acl aclname myportname 3128 ... # *_port name [fast] +# +# acl aclname proto HTTP FTP ... # request protocol [fast] +# +# acl aclname method GET POST ... # HTTP request method [fast] +# +# acl aclname http_status 200 301 500- 400-403 ... +# # status code in reply [fast] +# +# acl aclname browser [-i] regexp ... +# # pattern match on User-Agent header (see also req_header below) [fast] +# +# acl aclname referer_regex [-i] regexp ... +# # pattern match on Referer header [fast] +# # Referer is highly unreliable, so use with care +# +# acl aclname ident username ... +# acl aclname ident_regex [-i] pattern ... +# # string match on ident output [slow] +# # use REQUIRED to accept any non-null ident. +# +# acl aclname proxy_auth [-i] username ... +# acl aclname proxy_auth_regex [-i] pattern ... +# # perform http authentication challenge to the client and match against +# # supplied credentials [slow] +# # +# # takes a list of allowed usernames. +# # use REQUIRED to accept any valid username. +# # +# # Will use proxy authentication in forward-proxy scenarios, and plain +# # http authenticaiton in reverse-proxy scenarios +# # +# # NOTE: when a Proxy-Authentication header is sent but it is not +# # needed during ACL checking the username is NOT logged +# # in access.log. +# # +# # NOTE: proxy_auth requires a EXTERNAL authentication program +# # to check username/password combinations (see +# # auth_param directive). +# # +# # NOTE: proxy_auth can't be used in a transparent/intercepting proxy +# # as the browser needs to be configured for using a proxy in order +# # to respond to proxy authentication. +# +# acl aclname snmp_community string ... +# # A community string to limit access to your SNMP Agent [fast] +# # Example: +# # +# # acl snmppublic snmp_community public +# +# acl aclname maxconn number +# # This will be matched when the client's IP address has +# # more than <number> TCP connections established. [fast] +# # NOTE: This only measures direct TCP links so X-Forwarded-For +# # indirect clients are not counted. +# +# acl aclname max_user_ip [-s] number +# # This will be matched when the user attempts to log in from more +# # than <number> different ip addresses. The authenticate_ip_ttl +# # parameter controls the timeout on the ip entries. [fast] +# # If -s is specified the limit is strict, denying browsing +# # from any further IP addresses until the ttl has expired. Without +# # -s Squid will just annoy the user by "randomly" denying requests. +# # (the counter is reset each time the limit is reached and a +# # request is denied) +# # NOTE: in acceleration mode or where there is mesh of child proxies, +# # clients may appear to come from multiple addresses if they are +# # going through proxy farms, so a limit of 1 may cause user problems. +# +# acl aclname random probability +# # Pseudo-randomly match requests. Based on the probability given. +# # Probability may be written as a decimal (0.333), fraction (1/3) +# # or ratio of matches:non-matches (3:5). +# +# acl aclname req_mime_type [-i] mime-type ... +# # regex match against the mime type of the request generated +# # by the client. Can be used to detect file upload or some +# # types HTTP tunneling requests [fast] +# # NOTE: This does NOT match the reply. You cannot use this +# # to match the returned file type. +# +# acl aclname req_header header-name [-i] any\.regex\.here +# # regex match against any of the known request headers. May be +# # thought of as a superset of "browser", "referer" and "mime-type" +# # ACL [fast] +# +# acl aclname rep_mime_type [-i] mime-type ... +# # regex match against the mime type of the reply received by +# # squid. Can be used to detect file download or some +# # types HTTP tunneling requests. [fast] +# # NOTE: This has no effect in http_access rules. It only has +# # effect in rules that affect the reply data stream such as +# # http_reply_access. +# +# acl aclname rep_header header-name [-i] any\.regex\.here +# # regex match against any of the known reply headers. May be +# # thought of as a superset of "browser", "referer" and "mime-type" +# # ACLs [fast] +# +# acl aclname external class_name [arguments...] +# # external ACL lookup via a helper class defined by the +# # external_acl_type directive [slow] +# +# acl aclname user_cert attribute values... +# # match against attributes in a user SSL certificate +# # attribute is one of DN/C/O/CN/L/ST or a numerical OID [fast] +# +# acl aclname ca_cert attribute values... +# # match against attributes a users issuing CA SSL certificate +# # attribute is one of DN/C/O/CN/L/ST or a numerical OID [fast] +# +# acl aclname ext_user username ... +# acl aclname ext_user_regex [-i] pattern ... +# # string match on username returned by external acl helper [slow] +# # use REQUIRED to accept any non-null user name. +# +# acl aclname tag tagvalue ... +# # string match on tag returned by external acl helper [fast] +# # DEPRECATED. Only the first tag will match with this ACL. +# # Use the 'note' ACL instead for handling multiple tag values. +# +# acl aclname hier_code codename ... +# # string match against squid hierarchy code(s); [fast] +# # e.g., DIRECT, PARENT_HIT, NONE, etc. +# # +# # NOTE: This has no effect in http_access rules. It only has +# # effect in rules that affect the reply data stream such as +# # http_reply_access. +# +# acl aclname note name [value ...] +# # match transaction annotation [fast] +# # Without values, matches any annotation with a given name. +# # With value(s), matches any annotation with a given name that +# # also has one of the given values. +# # Names and values are compared using a string equality test. +# # Annotation sources include note and adaptation_meta directives +# # as well as helper and eCAP responses. +# +# acl aclname adaptation_service service ... +# # Matches the name of any icap_service, ecap_service, +# # adaptation_service_set, or adaptation_service_chain that Squid +# # has used (or attempted to use) for the master transaction. +# # This ACL must be defined after the corresponding adaptation +# # service is named in squid.conf. This ACL is usable with +# # adaptation_meta because it starts matching immediately after +# # the service has been selected for adaptation. +# +# acl aclname any-of acl1 acl2 ... +# # match any one of the acls [fast or slow] +# # The first matching ACL stops further ACL evaluation. +# # +# # ACLs from multiple any-of lines with the same name are ORed. +# # For example, A = (a1 or a2) or (a3 or a4) can be written as +# # acl A any-of a1 a2 +# # acl A any-of a3 a4 +# # +# # This group ACL is fast if all evaluated ACLs in the group are fast +# # and slow otherwise. +# +# acl aclname all-of acl1 acl2 ... +# # match all of the acls [fast or slow] +# # The first mismatching ACL stops further ACL evaluation. +# # +# # ACLs from multiple all-of lines with the same name are ORed. +# # For example, B = (b1 and b2) or (b3 and b4) can be written as +# # acl B all-of b1 b2 +# # acl B all-of b3 b4 +# # +# # This group ACL is fast if all evaluated ACLs in the group are fast +# # and slow otherwise. +# +# Examples: +# acl macaddress arp 09:00:2b:23:45:67 +# acl myexample dst_as 1241 +# acl password proxy_auth REQUIRED +# acl fileupload req_mime_type -i ^multipart/form-data$ +# acl javascript rep_mime_type -i ^application/x-javascript$ +# +#Default: +# ACLs all, manager, localhost, and to_localhost are predefined. +# +# +# Recommended minimum configuration: +# + +# Example rule allowing access from your local networks. +# Adapt to list your (internal) IP networks from where browsing +# should be allowed +#acl localnet src 10.0.0.0/8 # RFC1918 possible internal network +acl localnet src 172.16.0.0/12 # RFC1918 possible internal network +acl localnet src 192.168.0.0/16 # RFC1918 possible internal network +#acl localnet src fc00::/7 # RFC 4193 local private network range +#acl localnet src fe80::/10 # RFC 4291 link-local (directly plugged) machines + +acl SSL_ports port 443 +acl Safe_ports port 80 # http +acl Safe_ports port 21 # ftp +acl Safe_ports port 443 # https +acl Safe_ports port 70 # gopher +acl Safe_ports port 210 # wais +acl Safe_ports port 1025-65535 # unregistered ports +acl Safe_ports port 280 # http-mgmt +acl Safe_ports port 488 # gss-http +acl Safe_ports port 591 # filemaker +acl Safe_ports port 777 # multiling http +acl CONNECT method CONNECT + +# TAG: proxy_protocol_access +# Determine which client proxies can be trusted to provide correct +# information regarding real client IP address using PROXY protocol. +# +# Requests may pass through a chain of several other proxies +# before reaching us. The original source details may by sent in: +# * HTTP message Forwarded header, or +# * HTTP message X-Forwarded-For header, or +# * PROXY protocol connection header. +# +# This directive is solely for validating new PROXY protocol +# connections received from a port flagged with require-proxy-header. +# It is checked only once after TCP connection setup. +# +# A deny match results in TCP connection closure. +# +# An allow match is required for Squid to permit the corresponding +# TCP connection, before Squid even looks for HTTP request headers. +# If there is an allow match, Squid starts using PROXY header information +# to determine the source address of the connection for all future ACL +# checks, logging, etc. +# +# SECURITY CONSIDERATIONS: +# +# Any host from which we accept client IP details can place +# incorrect information in the relevant header, and Squid +# will use the incorrect information as if it were the +# source address of the request. This may enable remote +# hosts to bypass any access control restrictions that are +# based on the client's source addresses. +# +# This clause only supports fast acl types. +# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details. +#Default: +# all TCP connections to ports with require-proxy-header will be denied + +# TAG: follow_x_forwarded_for +# Determine which client proxies can be trusted to provide correct +# information regarding real client IP address. +# +# Requests may pass through a chain of several other proxies +# before reaching us. The original source details may by sent in: +# * HTTP message Forwarded header, or +# * HTTP message X-Forwarded-For header, or +# * PROXY protocol connection header. +# +# PROXY protocol connections are controlled by the proxy_protocol_access +# directive which is checked before this. +# +# If a request reaches us from a source that is allowed by this +# directive, then we trust the information it provides regarding +# the IP of the client it received from (if any). +# +# For the purpose of ACLs used in this directive the src ACL type always +# matches the address we are testing and srcdomain matches its rDNS. +# +# On each HTTP request Squid checks for X-Forwarded-For header fields. +# If found the header values are iterated in reverse order and an allow +# match is required for Squid to continue on to the next value. +# The verification ends when a value receives a deny match, cannot be +# tested, or there are no more values to test. +# NOTE: Squid does not yet follow the Forwarded HTTP header. +# +# The end result of this process is an IP address that we will +# refer to as the indirect client address. This address may +# be treated as the client address for access control, ICAP, delay +# pools and logging, depending on the acl_uses_indirect_client, +# icap_uses_indirect_client, delay_pool_uses_indirect_client, +# log_uses_indirect_client and tproxy_uses_indirect_client options. +# +# This clause only supports fast acl types. +# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details. +# +# SECURITY CONSIDERATIONS: +# +# Any host from which we accept client IP details can place +# incorrect information in the relevant header, and Squid +# will use the incorrect information as if it were the +# source address of the request. This may enable remote +# hosts to bypass any access control restrictions that are +# based on the client's source addresses. +# +# For example: +# +# acl localhost src 127.0.0.1 +# acl my_other_proxy srcdomain .proxy.example.com +# follow_x_forwarded_for allow localhost +# follow_x_forwarded_for allow my_other_proxy +#Default: +# X-Forwarded-For header will be ignored. + +# TAG: acl_uses_indirect_client on|off +# Controls whether the indirect client address +# (see follow_x_forwarded_for) is used instead of the +# direct client address in acl matching. +# +# NOTE: maxconn ACL considers direct TCP links and indirect +# clients will always have zero. So no match. +#Default: +# acl_uses_indirect_client on + +# TAG: delay_pool_uses_indirect_client on|off +# Controls whether the indirect client address +# (see follow_x_forwarded_for) is used instead of the +# direct client address in delay pools. +#Default: +# delay_pool_uses_indirect_client on + +# TAG: log_uses_indirect_client on|off +# Controls whether the indirect client address +# (see follow_x_forwarded_for) is used instead of the +# direct client address in the access log. +#Default: +# log_uses_indirect_client on + +# TAG: tproxy_uses_indirect_client on|off +# Controls whether the indirect client address +# (see follow_x_forwarded_for) is used instead of the +# direct client address when spoofing the outgoing client. +# +# This has no effect on requests arriving in non-tproxy +# mode ports. +# +# SECURITY WARNING: Usage of this option is dangerous +# and should not be used trivially. Correct configuration +# of follow_x_forwarded_for with a limited set of trusted +# sources is required to prevent abuse of your proxy. +#Default: +# tproxy_uses_indirect_client off + +# TAG: spoof_client_ip +# Control client IP address spoofing of TPROXY traffic based on +# defined access lists. +# +# spoof_client_ip allow|deny [!]aclname ... +# +# If there are no "spoof_client_ip" lines present, the default +# is to "allow" spoofing of any suitable request. +# +# Note that the cache_peer "no-tproxy" option overrides this ACL. +# +# This clause supports fast acl types. +# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details. +#Default: +# Allow spoofing on all TPROXY traffic. + +# TAG: http_access +# Allowing or Denying access based on defined access lists +# +# To allow or deny a message received on an HTTP, HTTPS, or FTP port: +# http_access allow|deny [!]aclname ... +# +# NOTE on default values: +# +# If there are no "access" lines present, the default is to deny +# the request. +# +# If none of the "access" lines cause a match, the default is the +# opposite of the last line in the list. If the last line was +# deny, the default is allow. Conversely, if the last line +# is allow, the default will be deny. For these reasons, it is a +# good idea to have an "deny all" entry at the end of your access +# lists to avoid potential confusion. +# +# This clause supports both fast and slow acl types. +# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details. +# +#Default: +# Deny, unless rules exist in squid.conf. +# + +# +# Recommended minimum Access Permission configuration: +# +# Deny requests to certain unsafe ports +http_access deny !Safe_ports + +# Deny CONNECT to other than secure SSL ports +http_access deny CONNECT !SSL_ports + +# Only allow cachemgr access from localhost +http_access allow localhost manager +http_access deny manager + +# We strongly recommend the following be uncommented to protect innocent +# web applications running on the proxy server who think the only +# one who can access services on "localhost" is a local user +#http_access deny to_localhost + +# +# INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS +# + +# Example rule allowing access from your local networks. +# Adapt localnet in the ACL section to list your (internal) IP networks +# from where browsing should be allowed +http_access allow localnet +http_access allow localhost + +# And finally deny all other access to this proxy +http_access deny all + +# TAG: adapted_http_access +# Allowing or Denying access based on defined access lists +# +# Essentially identical to http_access, but runs after redirectors +# and ICAP/eCAP adaptation. Allowing access control based on their +# output. +# +# If not set then only http_access is used. +#Default: +# Allow, unless rules exist in squid.conf. + +# TAG: http_reply_access +# Allow replies to client requests. This is complementary to http_access. +# +# http_reply_access allow|deny [!] aclname ... +# +# NOTE: if there are no access lines present, the default is to allow +# all replies. +# +# If none of the access lines cause a match the opposite of the +# last line will apply. Thus it is good practice to end the rules +# with an "allow all" or "deny all" entry. +# +# This clause supports both fast and slow acl types. +# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details. +#Default: +# Allow, unless rules exist in squid.conf. + +# TAG: icp_access +# Allowing or Denying access to the ICP port based on defined +# access lists +# +# icp_access allow|deny [!]aclname ... +# +# NOTE: The default if no icp_access lines are present is to +# deny all traffic. This default may cause problems with peers +# using ICP. +# +# This clause only supports fast acl types. +# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details. +# +## Allow ICP queries from local networks only +##icp_access allow localnet +##icp_access deny all +#Default: +# Deny, unless rules exist in squid.conf. + +# TAG: htcp_access +# Allowing or Denying access to the HTCP port based on defined +# access lists +# +# htcp_access allow|deny [!]aclname ... +# +# See also htcp_clr_access for details on access control for +# cache purge (CLR) HTCP messages. +# +# NOTE: The default if no htcp_access lines are present is to +# deny all traffic. This default may cause problems with peers +# using the htcp option. +# +# This clause only supports fast acl types. +# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details. +# +## Allow HTCP queries from local networks only +##htcp_access allow localnet +##htcp_access deny all +#Default: +# Deny, unless rules exist in squid.conf. + +# TAG: htcp_clr_access +# Allowing or Denying access to purge content using HTCP based +# on defined access lists. +# See htcp_access for details on general HTCP access control. +# +# htcp_clr_access allow|deny [!]aclname ... +# +# This clause only supports fast acl types. +# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details. +# +## Allow HTCP CLR requests from trusted peers +#acl htcp_clr_peer src 192.0.2.2 2001:DB8::2 +#htcp_clr_access allow htcp_clr_peer +#htcp_clr_access deny all +#Default: +# Deny, unless rules exist in squid.conf. + +# TAG: miss_access +# Determines whether network access is permitted when satisfying a request. +# +# For example; +# to force your neighbors to use you as a sibling instead of +# a parent. +# +# acl localclients src 192.0.2.0/24 2001:DB8::a:0/64 +# miss_access deny !localclients +# miss_access allow all +# +# This means only your local clients are allowed to fetch relayed/MISS +# replies from the network and all other clients can only fetch cached +# objects (HITs). +# +# The default for this setting allows all clients who passed the +# http_access rules to relay via this proxy. +# +# This clause only supports fast acl types. +# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details. +#Default: +# Allow, unless rules exist in squid.conf. + +# TAG: ident_lookup_access +# A list of ACL elements which, if matched, cause an ident +# (RFC 931) lookup to be performed for this request. For +# example, you might choose to always perform ident lookups +# for your main multi-user Unix boxes, but not for your Macs +# and PCs. By default, ident lookups are not performed for +# any requests. +# +# To enable ident lookups for specific client addresses, you +# can follow this example: +# +# acl ident_aware_hosts src 198.168.1.0/24 +# ident_lookup_access allow ident_aware_hosts +# ident_lookup_access deny all +# +# Only src type ACL checks are fully supported. A srcdomain +# ACL might work at times, but it will not always provide +# the correct result. +# +# This clause only supports fast acl types. +# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details. +#Default: +# Unless rules exist in squid.conf, IDENT is not fetched. + +# TAG: reply_body_max_size size [acl acl...] +# This option specifies the maximum size of a reply body. It can be +# used to prevent users from downloading very large files, such as +# MP3's and movies. When the reply headers are received, the +# reply_body_max_size lines are processed, and the first line where +# all (if any) listed ACLs are true is used as the maximum body size +# for this reply. +# +# This size is checked twice. First when we get the reply headers, +# we check the content-length value. If the content length value exists +# and is larger than the allowed size, the request is denied and the +# user receives an error message that says "the request or reply +# is too large." If there is no content-length, and the reply +# size exceeds this limit, the client's connection is just closed +# and they will receive a partial reply. +# +# WARNING: downstream caches probably can not detect a partial reply +# if there is no content-length header, so they will cache +# partial responses and give them out as hits. You should NOT +# use this option if you have downstream caches. +# +# WARNING: A maximum size smaller than the size of squid's error messages +# will cause an infinite loop and crash squid. Ensure that the smallest +# non-zero value you use is greater that the maximum header size plus +# the size of your largest error page. +# +# If you set this parameter none (the default), there will be +# no limit imposed. +# +# Configuration Format is: +# reply_body_max_size SIZE UNITS [acl ...] +# ie. +# reply_body_max_size 10 MB +# +#Default: +# No limit is applied. + +# NETWORK OPTIONS +# ----------------------------------------------------------------------------- + +# TAG: http_port +# Usage: port [mode] [options] +# hostname:port [mode] [options] +# 1.2.3.4:port [mode] [options] +# +# The socket addresses where Squid will listen for HTTP client +# requests. You may specify multiple socket addresses. +# There are three forms: port alone, hostname with port, and +# IP address with port. If you specify a hostname or IP +# address, Squid binds the socket to that specific +# address. Most likely, you do not need to bind to a specific +# address, so you can use the port number alone. +# +# If you are running Squid in accelerator mode, you +# probably want to listen on port 80 also, or instead. +# +# The -a command line option may be used to specify additional +# port(s) where Squid listens for proxy request. Such ports will +# be plain proxy ports with no options. +# +# You may specify multiple socket addresses on multiple lines. +# +# Modes: +# +# intercept Support for IP-Layer NAT interception delivering +# traffic to this Squid port. +# NP: disables authentication on the port. +# +# tproxy Support Linux TPROXY (or BSD divert-to) with spoofing +# of outgoing connections using the client IP address. +# NP: disables authentication on the port. +# +# accel Accelerator / reverse proxy mode +# +# ssl-bump For each CONNECT request allowed by ssl_bump ACLs, +# establish secure connection with the client and with +# the server, decrypt HTTPS messages as they pass through +# Squid, and treat them as unencrypted HTTP messages, +# becoming the man-in-the-middle. +# +# The ssl_bump option is required to fully enable +# bumping of CONNECT requests. +# +# Omitting the mode flag causes default forward proxy mode to be used. +# +# +# Accelerator Mode Options: +# +# defaultsite=domainname +# What to use for the Host: header if it is not present +# in a request. Determines what site (not origin server) +# accelerators should consider the default. +# +# no-vhost Disable using HTTP/1.1 Host header for virtual domain support. +# +# protocol= Protocol to reconstruct accelerated and intercepted +# requests with. Defaults to HTTP/1.1 for http_port and +# HTTPS/1.1 for https_port. +# When an unsupported value is configured Squid will +# produce a FATAL error. +# Values: HTTP or HTTP/1.1, HTTPS or HTTPS/1.1 +# +# vport Virtual host port support. Using the http_port number +# instead of the port passed on Host: headers. +# +# vport=NN Virtual host port support. Using the specified port +# number instead of the port passed on Host: headers. +# +# act-as-origin +# Act as if this Squid is the origin server. +# This currently means generate new Date: and Expires: +# headers on HIT instead of adding Age:. +# +# ignore-cc Ignore request Cache-Control headers. +# +# WARNING: This option violates HTTP specifications if +# used in non-accelerator setups. +# +# allow-direct Allow direct forwarding in accelerator mode. Normally +# accelerated requests are denied direct forwarding as if +# never_direct was used. +# +# WARNING: this option opens accelerator mode to security +# vulnerabilities usually only affecting in interception +# mode. Make sure to protect forwarding with suitable +# http_access rules when using this. +# +# +# SSL Bump Mode Options: +# In addition to these options ssl-bump requires TLS/SSL options. +# +# generate-host-certificates[=<on|off>] +# Dynamically create SSL server certificates for the +# destination hosts of bumped CONNECT requests.When +# enabled, the cert and key options are used to sign +# generated certificates. Otherwise generated +# certificate will be selfsigned. +# If there is a CA certificate lifetime of the generated +# certificate equals lifetime of the CA certificate. If +# generated certificate is selfsigned lifetime is three +# years. +# This option is disabled by default. See the ssl-bump +# option above for more information. +# +# dynamic_cert_mem_cache_size=SIZE +# Approximate total RAM size spent on cached generated +# certificates. If set to zero, caching is disabled. +# +# TLS / SSL Options: +# +# cert= Path to SSL certificate (PEM format). +# +# key= Path to SSL private key file (PEM format) +# if not specified, the certificate file is +# assumed to be a combined certificate and +# key file. +# +# version= The version of SSL/TLS supported +# 1 automatic (default) +# 2 SSLv2 only +# 3 SSLv3 only +# 4 TLSv1.0 only +# 5 TLSv1.1 only +# 6 TLSv1.2 only +# +# cipher= Colon separated list of supported ciphers. +# NOTE: some ciphers such as EDH ciphers depend on +# additional settings. If those settings are +# omitted the ciphers may be silently ignored +# by the OpenSSL library. +# +# options= Various SSL implementation options. The most important +# being: +# NO_SSLv2 Disallow the use of SSLv2 +# NO_SSLv3 Disallow the use of SSLv3 +# NO_TLSv1 Disallow the use of TLSv1.0 +# NO_TLSv1_1 Disallow the use of TLSv1.1 +# NO_TLSv1_2 Disallow the use of TLSv1.2 +# SINGLE_DH_USE Always create a new key when using +# temporary/ephemeral DH key exchanges +# NO_TICKET Disables TLS tickets extension +# +# SINGLE_ECDH_USE +# Enable ephemeral ECDH key exchange. +# The adopted curve should be specified +# using the tls-dh option. +# +# ALL Enable various bug workarounds +# suggested as "harmless" by OpenSSL +# Be warned that this reduces SSL/TLS +# strength to some attacks. +# See OpenSSL SSL_CTX_set_options documentation for a +# complete list of options. +# +# clientca= File containing the list of CAs to use when +# requesting a client certificate. +# +# cafile= File containing additional CA certificates to +# use when verifying client certificates. If unset +# clientca will be used. +# +# capath= Directory containing additional CA certificates +# and CRL lists to use when verifying client certificates. +# +# crlfile= File of additional CRL lists to use when verifying +# the client certificate, in addition to CRLs stored in +# the capath. Implies VERIFY_CRL flag below. +# +# tls-dh=[curve:]file +# File containing DH parameters for temporary/ephemeral DH key +# exchanges, optionally prefixed by a curve for ephemeral ECDH +# key exchanges. +# See OpenSSL documentation for details on how to create the +# DH parameter file. Supported curves for ECDH can be listed +# using the "openssl ecparam -list_curves" command. +# WARNING: EDH and EECDH ciphers will be silently disabled if +# this option is not set. +# +# sslflags= Various flags modifying the use of SSL: +# DELAYED_AUTH +# Don't request client certificates +# immediately, but wait until acl processing +# requires a certificate (not yet implemented). +# NO_DEFAULT_CA +# Don't use the default CA lists built in +# to OpenSSL. +# NO_SESSION_REUSE +# Don't allow for session reuse. Each connection +# will result in a new SSL session. +# VERIFY_CRL +# Verify CRL lists when accepting client +# certificates. +# VERIFY_CRL_ALL +# Verify CRL lists for all certificates in the +# client certificate chain. +# +# sslcontext= SSL session ID context identifier. +# +# Other Options: +# +# connection-auth[=on|off] +# use connection-auth=off to tell Squid to prevent +# forwarding Microsoft connection oriented authentication +# (NTLM, Negotiate and Kerberos) +# +# disable-pmtu-discovery= +# Control Path-MTU discovery usage: +# off lets OS decide on what to do (default). +# transparent disable PMTU discovery when transparent +# support is enabled. +# always disable always PMTU discovery. +# +# In many setups of transparently intercepting proxies +# Path-MTU discovery can not work on traffic towards the +# clients. This is the case when the intercepting device +# does not fully track connections and fails to forward +# ICMP must fragment messages to the cache server. If you +# have such setup and experience that certain clients +# sporadically hang or never complete requests set +# disable-pmtu-discovery option to 'transparent'. +# +# name= Specifies a internal name for the port. Defaults to +# the port specification (port or addr:port) +# +# tcpkeepalive[=idle,interval,timeout] +# Enable TCP keepalive probes of idle connections. +# In seconds; idle is the initial time before TCP starts +# probing the connection, interval how often to probe, and +# timeout the time before giving up. +# +# require-proxy-header +# Require PROXY protocol version 1 or 2 connections. +# The proxy_protocol_access is required to whitelist +# downstream proxies which can be trusted. +# +# If you run Squid on a dual-homed machine with an internal +# and an external interface we recommend you to specify the +# internal address:port in http_port. This way Squid will only be +# visible on the internal address. +# +# + +# Squid normally listens to port 3128 +http_port 3128 + +# TAG: https_port +# Note: This option is only available if Squid is rebuilt with the +# --with-openssl +# +# Usage: [ip:]port cert=certificate.pem [key=key.pem] [mode] [options...] +# +# The socket address where Squid will listen for client requests made +# over TLS or SSL connections. Commonly referred to as HTTPS. +# +# This is most useful for situations where you are running squid in +# accelerator mode and you want to do the SSL work at the accelerator level. +# +# You may specify multiple socket addresses on multiple lines, +# each with their own SSL certificate and/or options. +# +# Modes: +# +# accel Accelerator / reverse proxy mode +# +# intercept Support for IP-Layer interception of +# outgoing requests without browser settings. +# NP: disables authentication and IPv6 on the port. +# +# tproxy Support Linux TPROXY for spoofing outgoing +# connections using the client IP address. +# NP: disables authentication and maybe IPv6 on the port. +# +# ssl-bump For each intercepted connection allowed by ssl_bump +# ACLs, establish a secure connection with the client and with +# the server, decrypt HTTPS messages as they pass through +# Squid, and treat them as unencrypted HTTP messages, +# becoming the man-in-the-middle. +# +# An "ssl_bump server-first" match is required to +# fully enable bumping of intercepted SSL connections. +# +# Requires tproxy or intercept. +# +# Omitting the mode flag causes default forward proxy mode to be used. +# +# +# See http_port for a list of generic options +# +# +# SSL Options: +# +# cert= Path to SSL certificate (PEM format). +# +# key= Path to SSL private key file (PEM format) +# if not specified, the certificate file is +# assumed to be a combined certificate and +# key file. +# +# version= The version of SSL/TLS supported +# 1 automatic (default) +# 2 SSLv2 only +# 3 SSLv3 only +# 4 TLSv1 only +# +# cipher= Colon separated list of supported ciphers. +# +# options= Various SSL engine options. The most important +# being: +# NO_SSLv2 Disallow the use of SSLv2 +# NO_SSLv3 Disallow the use of SSLv3 +# NO_TLSv1 Disallow the use of TLSv1 +# +# SINGLE_DH_USE Always create a new key when using +# temporary/ephemeral DH key exchanges +# +# SINGLE_ECDH_USE +# Enable ephemeral ECDH key exchange. +# The adopted curve should be specified +# using the tls-dh option. +# +# See src/ssl_support.c or OpenSSL SSL_CTX_set_options +# documentation for a complete list of options. +# +# clientca= File containing the list of CAs to use when +# requesting a client certificate. +# +# cafile= File containing additional CA certificates to +# use when verifying client certificates. If unset +# clientca will be used. +# +# capath= Directory containing additional CA certificates +# and CRL lists to use when verifying client certificates. +# +# crlfile= File of additional CRL lists to use when verifying +# the client certificate, in addition to CRLs stored in +# the capath. Implies VERIFY_CRL flag below. +# +# tls-dh=[curve:]file +# File containing DH parameters for temporary/ephemeral DH key +# exchanges, optionally prefixed by a curve for ephemeral ECDH +# key exchanges. +# +# sslflags= Various flags modifying the use of SSL: +# DELAYED_AUTH +# Don't request client certificates +# immediately, but wait until acl processing +# requires a certificate (not yet implemented). +# NO_DEFAULT_CA +# Don't use the default CA lists built in +# to OpenSSL. +# NO_SESSION_REUSE +# Don't allow for session reuse. Each connection +# will result in a new SSL session. +# VERIFY_CRL +# Verify CRL lists when accepting client +# certificates. +# VERIFY_CRL_ALL +# Verify CRL lists for all certificates in the +# client certificate chain. +# +# sslcontext= SSL session ID context identifier. +# +# generate-host-certificates[=<on|off>] +# Dynamically create SSL server certificates for the +# destination hosts of bumped SSL requests.When +# enabled, the cert and key options are used to sign +# generated certificates. Otherwise generated +# certificate will be selfsigned. +# If there is CA certificate life time of generated +# certificate equals lifetime of CA certificate. If +# generated certificate is selfsigned lifetime is three +# years. +# This option is disabled by default. See the ssl-bump +# option above for more information. +# +# dynamic_cert_mem_cache_size=SIZE +# Approximate total RAM size spent on cached generated +# certificates. If set to zero, caching is disabled. +# +# See http_port for a list of available options. +#Default: +# none + +# TAG: ftp_port +# Enables Native FTP proxy by specifying the socket address where Squid +# listens for FTP client requests. See http_port directive for various +# ways to specify the listening address and mode. +# +# Usage: ftp_port address [mode] [options] +# +# WARNING: This is a new, experimental, complex feature that has seen +# limited production exposure. Some Squid modules (e.g., caching) do not +# currently work with native FTP proxying, and many features have not +# even been tested for compatibility. Test well before deploying! +# +# Native FTP proxying differs substantially from proxying HTTP requests +# with ftp:// URIs because Squid works as an FTP server and receives +# actual FTP commands (rather than HTTP requests with FTP URLs). +# +# Native FTP commands accepted at ftp_port are internally converted or +# wrapped into HTTP-like messages. The same happens to Native FTP +# responses received from FTP origin servers. Those HTTP-like messages +# are shoveled through regular access control and adaptation layers +# between the FTP client and the FTP origin server. This allows Squid to +# examine, adapt, block, and log FTP exchanges. Squid reuses most HTTP +# mechanisms when shoveling wrapped FTP messages. For example, +# http_access and adaptation_access directives are used. +# +# Modes: +# +# intercept Same as http_port intercept. The FTP origin address is +# determined based on the intended destination of the +# intercepted connection. +# +# tproxy Support Linux TPROXY for spoofing outgoing +# connections using the client IP address. +# NP: disables authentication and maybe IPv6 on the port. +# +# By default (i.e., without an explicit mode option), Squid extracts the +# FTP origin address from the login@origin parameter of the FTP USER +# command. Many popular FTP clients support such native FTP proxying. +# +# Options: +# +# name=token Specifies an internal name for the port. Defaults to +# the port address. Usable with myportname ACL. +# +# ftp-track-dirs +# Enables tracking of FTP directories by injecting extra +# PWD commands and adjusting Request-URI (in wrapping +# HTTP requests) to reflect the current FTP server +# directory. Tracking is disabled by default. +# +# protocol=FTP Protocol to reconstruct accelerated and intercepted +# requests with. Defaults to FTP. No other accepted +# values have been tested with. An unsupported value +# results in a FATAL error. Accepted values are FTP, +# HTTP (or HTTP/1.1), and HTTPS (or HTTPS/1.1). +# +# Other http_port modes and options that are not specific to HTTP and +# HTTPS may also work. +#Default: +# none + +# TAG: tcp_outgoing_tos +# Allows you to select a TOS/Diffserv value for packets outgoing +# on the server side, based on an ACL. +# +# tcp_outgoing_tos ds-field [!]aclname ... +# +# Example where normal_service_net uses the TOS value 0x00 +# and good_service_net uses 0x20 +# +# acl normal_service_net src 10.0.0.0/24 +# acl good_service_net src 10.0.1.0/24 +# tcp_outgoing_tos 0x00 normal_service_net +# tcp_outgoing_tos 0x20 good_service_net +# +# TOS/DSCP values really only have local significance - so you should +# know what you're specifying. For more information, see RFC2474, +# RFC2475, and RFC3260. +# +# The TOS/DSCP byte must be exactly that - a octet value 0 - 255, or +# "default" to use whatever default your host has. +# Note that only multiples of 4 are usable as the two rightmost bits have +# been redefined for use by ECN (RFC 3168 section 23.1). +# The squid parser will enforce this by masking away the ECN bits. +# +# Processing proceeds in the order specified, and stops at first fully +# matching line. +# +# Only fast ACLs are supported. +#Default: +# none + +# TAG: clientside_tos +# Allows you to select a TOS/DSCP value for packets being transmitted +# on the client-side, based on an ACL. +# +# clientside_tos ds-field [!]aclname ... +# +# Example where normal_service_net uses the TOS value 0x00 +# and good_service_net uses 0x20 +# +# acl normal_service_net src 10.0.0.0/24 +# acl good_service_net src 10.0.1.0/24 +# clientside_tos 0x00 normal_service_net +# clientside_tos 0x20 good_service_net +# +# Note: This feature is incompatible with qos_flows. Any TOS values set here +# will be overwritten by TOS values in qos_flows. +# +# The TOS/DSCP byte must be exactly that - a octet value 0 - 255, or +# "default" to use whatever default your host has. +# Note that only multiples of 4 are usable as the two rightmost bits have +# been redefined for use by ECN (RFC 3168 section 23.1). +# The squid parser will enforce this by masking away the ECN bits. +# +#Default: +# none + +# TAG: tcp_outgoing_mark +# Note: This option is only available if Squid is rebuilt with the +# Packet MARK (Linux) +# +# Allows you to apply a Netfilter mark value to outgoing packets +# on the server side, based on an ACL. +# +# tcp_outgoing_mark mark-value [!]aclname ... +# +# Example where normal_service_net uses the mark value 0x00 +# and good_service_net uses 0x20 +# +# acl normal_service_net src 10.0.0.0/24 +# acl good_service_net src 10.0.1.0/24 +# tcp_outgoing_mark 0x00 normal_service_net +# tcp_outgoing_mark 0x20 good_service_net +# +# Only fast ACLs are supported. +#Default: +# none + +# TAG: clientside_mark +# Note: This option is only available if Squid is rebuilt with the +# Packet MARK (Linux) +# +# Allows you to apply a Netfilter mark value to packets being transmitted +# on the client-side, based on an ACL. +# +# clientside_mark mark-value [!]aclname ... +# +# Example where normal_service_net uses the mark value 0x00 +# and good_service_net uses 0x20 +# +# acl normal_service_net src 10.0.0.0/24 +# acl good_service_net src 10.0.1.0/24 +# clientside_mark 0x00 normal_service_net +# clientside_mark 0x20 good_service_net +# +# Note: This feature is incompatible with qos_flows. Any mark values set here +# will be overwritten by mark values in qos_flows. +#Default: +# none + +# TAG: qos_flows +# Allows you to select a TOS/DSCP value to mark outgoing +# connections to the client, based on where the reply was sourced. +# For platforms using netfilter, allows you to set a netfilter mark +# value instead of, or in addition to, a TOS value. +# +# By default this functionality is disabled. To enable it with the default +# settings simply use "qos_flows mark" or "qos_flows tos". Default +# settings will result in the netfilter mark or TOS value being copied +# from the upstream connection to the client. Note that it is the connection +# CONNMARK value not the packet MARK value that is copied. +# +# It is not currently possible to copy the mark or TOS value from the +# client to the upstream connection request. +# +# TOS values really only have local significance - so you should +# know what you're specifying. For more information, see RFC2474, +# RFC2475, and RFC3260. +# +# The TOS/DSCP byte must be exactly that - a octet value 0 - 255. +# Note that only multiples of 4 are usable as the two rightmost bits have +# been redefined for use by ECN (RFC 3168 section 23.1). +# The squid parser will enforce this by masking away the ECN bits. +# +# Mark values can be any unsigned 32-bit integer value. +# +# This setting is configured by setting the following values: +# +# tos|mark Whether to set TOS or netfilter mark values +# +# local-hit=0xFF Value to mark local cache hits. +# +# sibling-hit=0xFF Value to mark hits from sibling peers. +# +# parent-hit=0xFF Value to mark hits from parent peers. +# +# miss=0xFF[/mask] Value to mark cache misses. Takes precedence +# over the preserve-miss feature (see below), unless +# mask is specified, in which case only the bits +# specified in the mask are written. +# +# The TOS variant of the following features are only possible on Linux +# and require your kernel to be patched with the TOS preserving ZPH +# patch, available from http://zph.bratcheda.org +# No patch is needed to preserve the netfilter mark, which will work +# with all variants of netfilter. +# +# disable-preserve-miss +# This option disables the preservation of the TOS or netfilter +# mark. By default, the existing TOS or netfilter mark value of +# the response coming from the remote server will be retained +# and masked with miss-mark. +# NOTE: in the case of a netfilter mark, the mark must be set on +# the connection (using the CONNMARK target) not on the packet +# (MARK target). +# +# miss-mask=0xFF +# Allows you to mask certain bits in the TOS or mark value +# received from the remote server, before copying the value to +# the TOS sent towards clients. +# Default for tos: 0xFF (TOS from server is not changed). +# Default for mark: 0xFFFFFFFF (mark from server is not changed). +# +# All of these features require the --enable-zph-qos compilation flag +# (enabled by default). Netfilter marking also requires the +# libnetfilter_conntrack libraries (--with-netfilter-conntrack) and +# libcap 2.09+ (--with-libcap). +# +#Default: +# none + +# TAG: tcp_outgoing_address +# Allows you to map requests to different outgoing IP addresses +# based on the username or source address of the user making +# the request. +# +# tcp_outgoing_address ipaddr [[!]aclname] ... +# +# For example; +# Forwarding clients with dedicated IPs for certain subnets. +# +# acl normal_service_net src 10.0.0.0/24 +# acl good_service_net src 10.0.2.0/24 +# +# tcp_outgoing_address 2001:db8::c001 good_service_net +# tcp_outgoing_address 10.1.0.2 good_service_net +# +# tcp_outgoing_address 2001:db8::beef normal_service_net +# tcp_outgoing_address 10.1.0.1 normal_service_net +# +# tcp_outgoing_address 2001:db8::1 +# tcp_outgoing_address 10.1.0.3 +# +# Processing proceeds in the order specified, and stops at first fully +# matching line. +# +# Squid will add an implicit IP version test to each line. +# Requests going to IPv4 websites will use the outgoing 10.1.0.* addresses. +# Requests going to IPv6 websites will use the outgoing 2001:db8:* addresses. +# +# +# NOTE: The use of this directive using client dependent ACLs is +# incompatible with the use of server side persistent connections. To +# ensure correct results it is best to set server_persistent_connections +# to off when using this directive in such configurations. +# +# NOTE: The use of this directive to set a local IP on outgoing TCP links +# is incompatible with using TPROXY to set client IP out outbound TCP links. +# When needing to contact peers use the no-tproxy cache_peer option and the +# client_dst_passthru directive re-enable normal forwarding such as this. +# +#Default: +# Address selection is performed by the operating system. + +# TAG: host_verify_strict +# Regardless of this option setting, when dealing with intercepted +# traffic, Squid always verifies that the destination IP address matches +# the Host header domain or IP (called 'authority form URL'). +# +# This enforcement is performed to satisfy a MUST-level requirement in +# RFC 2616 section 14.23: "The Host field value MUST represent the naming +# authority of the origin server or gateway given by the original URL". +# +# When set to ON: +# Squid always responds with an HTTP 409 (Conflict) error +# page and logs a security warning if there is no match. +# +# Squid verifies that the destination IP address matches +# the Host header for forward-proxy and reverse-proxy traffic +# as well. For those traffic types, Squid also enables the +# following checks, comparing the corresponding Host header +# and Request-URI components: +# +# * The host names (domain or IP) must be identical, +# but valueless or missing Host header disables all checks. +# For the two host names to match, both must be either IP +# or FQDN. +# +# * Port numbers must be identical, but if a port is missing +# the scheme-default port is assumed. +# +# +# When set to OFF (the default): +# Squid allows suspicious requests to continue but logs a +# security warning and blocks caching of the response. +# +# * Forward-proxy traffic is not checked at all. +# +# * Reverse-proxy traffic is not checked at all. +# +# * Intercepted traffic which passes verification is handled +# according to client_dst_passthru. +# +# * Intercepted requests which fail verification are sent +# to the client original destination instead of DIRECT. +# This overrides 'client_dst_passthru off'. +# +# For now suspicious intercepted CONNECT requests are always +# responded to with an HTTP 409 (Conflict) error page. +# +# +# SECURITY NOTE: +# +# As described in CVE-2009-0801 when the Host: header alone is used +# to determine the destination of a request it becomes trivial for +# malicious scripts on remote websites to bypass browser same-origin +# security policy and sandboxing protections. +# +# The cause of this is that such applets are allowed to perform their +# own HTTP stack, in which case the same-origin policy of the browser +# sandbox only verifies that the applet tries to contact the same IP +# as from where it was loaded at the IP level. The Host: header may +# be different from the connected IP and approved origin. +# +#Default: +# host_verify_strict off + +# TAG: client_dst_passthru +# With NAT or TPROXY intercepted traffic Squid may pass the request +# directly to the original client destination IP or seek a faster +# source using the HTTP Host header. +# +# Using Host to locate alternative servers can provide faster +# connectivity with a range of failure recovery options. +# But can also lead to connectivity trouble when the client and +# server are attempting stateful interactions unaware of the proxy. +# +# This option (on by default) prevents alternative DNS entries being +# located to send intercepted traffic DIRECT to an origin server. +# The clients original destination IP and port will be used instead. +# +# Regardless of this option setting, when dealing with intercepted +# traffic Squid will verify the Host: header and any traffic which +# fails Host verification will be treated as if this option were ON. +# +# see host_verify_strict for details on the verification process. +#Default: +# client_dst_passthru on + +# SSL OPTIONS +# ----------------------------------------------------------------------------- + +# TAG: ssl_unclean_shutdown +# Note: This option is only available if Squid is rebuilt with the +# --with-openssl +# +# Some browsers (especially MSIE) bugs out on SSL shutdown +# messages. +#Default: +# ssl_unclean_shutdown off + +# TAG: ssl_engine +# Note: This option is only available if Squid is rebuilt with the +# --with-openssl +# +# The OpenSSL engine to use. You will need to set this if you +# would like to use hardware SSL acceleration for example. +#Default: +# none + +# TAG: sslproxy_client_certificate +# Note: This option is only available if Squid is rebuilt with the +# --with-openssl +# +# Client SSL Certificate to use when proxying https:// URLs +#Default: +# none + +# TAG: sslproxy_client_key +# Note: This option is only available if Squid is rebuilt with the +# --with-openssl +# +# Client SSL Key to use when proxying https:// URLs +#Default: +# none + +# TAG: sslproxy_version +# Note: This option is only available if Squid is rebuilt with the +# --with-openssl +# +# SSL version level to use when proxying https:// URLs +# +# The versions of SSL/TLS supported: +# +# 1 automatic (default) +# 2 SSLv2 only +# 3 SSLv3 only +# 4 TLSv1.0 only +# 5 TLSv1.1 only +# 6 TLSv1.2 only +#Default: +# automatic SSL/TLS version negotiation + +# TAG: sslproxy_options +# Note: This option is only available if Squid is rebuilt with the +# --with-openssl +# +# Colon (:) or comma (,) separated list of SSL implementation options +# to use when proxying https:// URLs +# +# The most important being: +# +# NO_SSLv2 Disallow the use of SSLv2 +# NO_SSLv3 Disallow the use of SSLv3 +# NO_TLSv1 Disallow the use of TLSv1.0 +# NO_TLSv1_1 Disallow the use of TLSv1.1 +# NO_TLSv1_2 Disallow the use of TLSv1.2 +# +# SINGLE_DH_USE +# Always create a new key when using temporary/ephemeral +# DH key exchanges +# +# NO_TICKET +# Disable use of RFC5077 session tickets. Some servers +# may have problems understanding the TLS extension due +# to ambiguous specification in RFC4507. +# +# ALL Enable various bug workarounds suggested as "harmless" +# by OpenSSL. Be warned that this may reduce SSL/TLS +# strength to some attacks. +# +# See the OpenSSL SSL_CTX_set_options documentation for a +# complete list of possible options. +# +# WARNING: This directive takes a single token. If a space is used +# the value(s) after that space are SILENTLY IGNORED. +#Default: +# none + +# TAG: sslproxy_cipher +# Note: This option is only available if Squid is rebuilt with the +# --with-openssl +# +# SSL cipher list to use when proxying https:// URLs +# +# Colon separated list of supported ciphers. +#Default: +# none + +# TAG: sslproxy_cafile +# Note: This option is only available if Squid is rebuilt with the +# --with-openssl +# +# file containing CA certificates to use when verifying server +# certificates while proxying https:// URLs +#Default: +# none + +# TAG: sslproxy_capath +# Note: This option is only available if Squid is rebuilt with the +# --with-openssl +# +# directory containing CA certificates to use when verifying +# server certificates while proxying https:// URLs +#Default: +# none + +# TAG: sslproxy_session_ttl +# Note: This option is only available if Squid is rebuilt with the +# --with-openssl +# +# Sets the timeout value for SSL sessions +#Default: +# sslproxy_session_ttl 300 + +# TAG: sslproxy_session_cache_size +# Note: This option is only available if Squid is rebuilt with the +# --with-openssl +# +# Sets the cache size to use for ssl session +#Default: +# sslproxy_session_cache_size 2 MB + +# TAG: sslproxy_foreign_intermediate_certs +# Note: This option is only available if Squid is rebuilt with the +# --with-openssl +# +# Many origin servers fail to send their full server certificate +# chain for verification, assuming the client already has or can +# easily locate any missing intermediate certificates. +# +# Squid uses the certificates from the specified file to fill in +# these missing chains when trying to validate origin server +# certificate chains. +# +# The file is expected to contain zero or more PEM-encoded +# intermediate certificates. These certificates are not treated +# as trusted root certificates, and any self-signed certificate in +# this file will be ignored. +#Default: +# none + +# TAG: sslproxy_cert_sign_hash +# Note: This option is only available if Squid is rebuilt with the +# --with-openssl +# +# Sets the hashing algorithm to use when signing generated certificates. +# Valid algorithm names depend on the OpenSSL library used. The following +# names are usually available: sha1, sha256, sha512, and md5. Please see +# your OpenSSL library manual for the available hashes. By default, Squids +# that support this option use sha256 hashes. +# +# Squid does not forcefully purge cached certificates that were generated +# with an algorithm other than the currently configured one. They remain +# in the cache, subject to the regular cache eviction policy, and become +# useful if the algorithm changes again. +#Default: +# none + +# TAG: ssl_bump +# Note: This option is only available if Squid is rebuilt with the +# --with-openssl +# +# This option is consulted when a CONNECT request is received on +# an http_port (or a new connection is intercepted at an +# https_port), provided that port was configured with an ssl-bump +# flag. The subsequent data on the connection is either treated as +# HTTPS and decrypted OR tunneled at TCP level without decryption, +# depending on the first matching bumping "action". +# +# ssl_bump <action> [!]acl ... +# +# The following bumping actions are currently supported: +# +# splice +# Become a TCP tunnel without decrypting proxied traffic. +# This is the default action. +# +# bump +# Establish a secure connection with the server and, using a +# mimicked server certificate, with the client. +# +# peek +# Receive client (step SslBump1) or server (step SslBump2) +# certificate while preserving the possibility of splicing the +# connection. Peeking at the server certificate (during step 2) +# usually precludes bumping of the connection at step 3. +# +# stare +# Receive client (step SslBump1) or server (step SslBump2) +# certificate while preserving the possibility of bumping the +# connection. Staring at the server certificate (during step 2) +# usually precludes splicing of the connection at step 3. +# +# terminate +# Close client and server connections. +# +# Backward compatibility actions available at step SslBump1: +# +# client-first +# Bump the connection. Establish a secure connection with the +# client first, then connect to the server. This old mode does +# not allow Squid to mimic server SSL certificate and does not +# work with intercepted SSL connections. +# +# server-first +# Bump the connection. Establish a secure connection with the +# server first, then establish a secure connection with the +# client, using a mimicked server certificate. Works with both +# CONNECT requests and intercepted SSL connections, but does +# not allow to make decisions based on SSL handshake info. +# +# peek-and-splice +# Decide whether to bump or splice the connection based on +# client-to-squid and server-to-squid SSL hello messages. +# XXX: Remove. +# +# none +# Same as the "splice" action. +# +# All ssl_bump rules are evaluated at each of the supported bumping +# steps. Rules with actions that are impossible at the current step are +# ignored. The first matching ssl_bump action wins and is applied at the +# end of the current step. If no rules match, the splice action is used. +# See the at_step ACL for a list of the supported SslBump steps. +# +# This clause supports both fast and slow acl types. +# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details. +# +# See also: http_port ssl-bump, https_port ssl-bump, and acl at_step. +# +# +# # Example: Bump all TLS connections except those originating from +# # localhost or those going to example.com. +# +# acl broken_sites ssl::server_name .example.com +# ssl_bump splice localhost +# ssl_bump splice broken_sites +# ssl_bump bump all +#Default: +# Become a TCP tunnel without decrypting proxied traffic. + +# TAG: sslproxy_flags +# Note: This option is only available if Squid is rebuilt with the +# --with-openssl +# +# Various flags modifying the use of SSL while proxying https:// URLs: +# DONT_VERIFY_PEER Accept certificates that fail verification. +# For refined control, see sslproxy_cert_error. +# NO_DEFAULT_CA Don't use the default CA list built in +# to OpenSSL. +#Default: +# none + +# TAG: sslproxy_cert_error +# Note: This option is only available if Squid is rebuilt with the +# --with-openssl +# +# Use this ACL to bypass server certificate validation errors. +# +# For example, the following lines will bypass all validation errors +# when talking to servers for example.com. All other +# validation errors will result in ERR_SECURE_CONNECT_FAIL error. +# +# acl BrokenButTrustedServers dstdomain example.com +# sslproxy_cert_error allow BrokenButTrustedServers +# sslproxy_cert_error deny all +# +# This clause only supports fast acl types. +# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details. +# Using slow acl types may result in server crashes +# +# Without this option, all server certificate validation errors +# terminate the transaction to protect Squid and the client. +# +# SQUID_X509_V_ERR_INFINITE_VALIDATION error cannot be bypassed +# but should not happen unless your OpenSSL library is buggy. +# +# SECURITY WARNING: +# Bypassing validation errors is dangerous because an +# error usually implies that the server cannot be trusted +# and the connection may be insecure. +# +# See also: sslproxy_flags and DONT_VERIFY_PEER. +#Default: +# Server certificate errors terminate the transaction. + +# TAG: sslproxy_cert_sign +# Note: This option is only available if Squid is rebuilt with the +# --with-openssl +# +# +# sslproxy_cert_sign <signing algorithm> acl ... +# +# The following certificate signing algorithms are supported: +# +# signTrusted +# Sign using the configured CA certificate which is usually +# placed in and trusted by end-user browsers. This is the +# default for trusted origin server certificates. +# +# signUntrusted +# Sign to guarantee an X509_V_ERR_CERT_UNTRUSTED browser error. +# This is the default for untrusted origin server certificates +# that are not self-signed (see ssl::certUntrusted). +# +# signSelf +# Sign using a self-signed certificate with the right CN to +# generate a X509_V_ERR_DEPTH_ZERO_SELF_SIGNED_CERT error in the +# browser. This is the default for self-signed origin server +# certificates (see ssl::certSelfSigned). +# +# This clause only supports fast acl types. +# +# When sslproxy_cert_sign acl(s) match, Squid uses the corresponding +# signing algorithm to generate the certificate and ignores all +# subsequent sslproxy_cert_sign options (the first match wins). If no +# acl(s) match, the default signing algorithm is determined by errors +# detected when obtaining and validating the origin server certificate. +# +# WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can +# be used with sslproxy_cert_adapt, but if and only if Squid is bumping a +# CONNECT request that carries a domain name. In all other cases (CONNECT +# to an IP address or an intercepted SSL connection), Squid cannot detect +# the domain mismatch at certificate generation time when +# bump-server-first is used. +#Default: +# none + +# TAG: sslproxy_cert_adapt +# Note: This option is only available if Squid is rebuilt with the +# --with-openssl +# +# +# sslproxy_cert_adapt <adaptation algorithm> acl ... +# +# The following certificate adaptation algorithms are supported: +# +# setValidAfter +# Sets the "Not After" property to the "Not After" property of +# the CA certificate used to sign generated certificates. +# +# setValidBefore +# Sets the "Not Before" property to the "Not Before" property of +# the CA certificate used to sign generated certificates. +# +# setCommonName or setCommonName{CN} +# Sets Subject.CN property to the host name specified as a +# CN parameter or, if no explicit CN parameter was specified, +# extracted from the CONNECT request. It is a misconfiguration +# to use setCommonName without an explicit parameter for +# intercepted or tproxied SSL connections. +# +# This clause only supports fast acl types. +# +# Squid first groups sslproxy_cert_adapt options by adaptation algorithm. +# Within a group, when sslproxy_cert_adapt acl(s) match, Squid uses the +# corresponding adaptation algorithm to generate the certificate and +# ignores all subsequent sslproxy_cert_adapt options in that algorithm's +# group (i.e., the first match wins within each algorithm group). If no +# acl(s) match, the default mimicking action takes place. +# +# WARNING: SQUID_X509_V_ERR_DOMAIN_MISMATCH and ssl:certDomainMismatch can +# be used with sslproxy_cert_adapt, but if and only if Squid is bumping a +# CONNECT request that carries a domain name. In all other cases (CONNECT +# to an IP address or an intercepted SSL connection), Squid cannot detect +# the domain mismatch at certificate generation time when +# bump-server-first is used. +#Default: +# none + +# TAG: sslpassword_program +# Note: This option is only available if Squid is rebuilt with the +# --with-openssl +# +# Specify a program used for entering SSL key passphrases +# when using encrypted SSL certificate keys. If not specified +# keys must either be unencrypted, or Squid started with the -N +# option to allow it to query interactively for the passphrase. +# +# The key file name is given as argument to the program allowing +# selection of the right password if you have multiple encrypted +# keys. +#Default: +# none + +# OPTIONS RELATING TO EXTERNAL SSL_CRTD +# ----------------------------------------------------------------------------- + +# TAG: sslcrtd_program +# Note: This option is only available if Squid is rebuilt with the +# --enable-ssl-crtd +# +# Specify the location and options of the executable for ssl_crtd process. +# /usr/lib/squid/ssl_crtd program requires -s and -M parameters +# For more information use: +# /usr/lib/squid/ssl_crtd -h +#Default: +# sslcrtd_program /usr/lib/squid/ssl_crtd -s /var/lib/ssl_db -M 4MB + +# TAG: sslcrtd_children +# Note: This option is only available if Squid is rebuilt with the +# --enable-ssl-crtd +# +# The maximum number of processes spawn to service ssl server. +# The maximum this may be safely set to is 32. +# +# The startup= and idle= options allow some measure of skew in your +# tuning. +# +# startup=N +# +# Sets the minimum number of processes to spawn when Squid +# starts or reconfigures. When set to zero the first request will +# cause spawning of the first child process to handle it. +# +# Starting too few children temporary slows Squid under load while it +# tries to spawn enough additional processes to cope with traffic. +# +# idle=N +# +# Sets a minimum of how many processes Squid is to try and keep available +# at all times. When traffic begins to rise above what the existing +# processes can handle this many more will be spawned up to the maximum +# configured. A minimum setting of 1 is required. +# +# You must have at least one ssl_crtd process. +#Default: +# sslcrtd_children 32 startup=5 idle=1 + +# TAG: sslcrtvalidator_program +# Note: This option is only available if Squid is rebuilt with the +# --with-openssl +# +# Specify the location and options of the executable for ssl_crt_validator +# process. +# +# Usage: sslcrtvalidator_program [ttl=n] [cache=n] path ... +# +# Options: +# ttl=n TTL in seconds for cached results. The default is 60 secs +# cache=n limit the result cache size. The default value is 2048 +#Default: +# none + +# TAG: sslcrtvalidator_children +# Note: This option is only available if Squid is rebuilt with the +# --with-openssl +# +# The maximum number of processes spawn to service SSL server. +# The maximum this may be safely set to is 32. +# +# The startup= and idle= options allow some measure of skew in your +# tuning. +# +# startup=N +# +# Sets the minimum number of processes to spawn when Squid +# starts or reconfigures. When set to zero the first request will +# cause spawning of the first child process to handle it. +# +# Starting too few children temporary slows Squid under load while it +# tries to spawn enough additional processes to cope with traffic. +# +# idle=N +# +# Sets a minimum of how many processes Squid is to try and keep available +# at all times. When traffic begins to rise above what the existing +# processes can handle this many more will be spawned up to the maximum +# configured. A minimum setting of 1 is required. +# +# concurrency= +# +# The number of requests each certificate validator helper can handle in +# parallel. A value of 0 indicates the certficate validator does not +# support concurrency. Defaults to 1. +# +# When this directive is set to a value >= 1 then the protocol +# used to communicate with the helper is modified to include +# a request ID in front of the request/response. The request +# ID from the request must be echoed back with the response +# to that request. +# +# You must have at least one ssl_crt_validator process. +#Default: +# sslcrtvalidator_children 32 startup=5 idle=1 concurrency=1 + +# OPTIONS WHICH AFFECT THE NEIGHBOR SELECTION ALGORITHM +# ----------------------------------------------------------------------------- + +# TAG: cache_peer +# To specify other caches in a hierarchy, use the format: +# +# cache_peer hostname type http-port icp-port [options] +# +# For example, +# +# # proxy icp +# # hostname type port port options +# # -------------------- -------- ----- ----- ----------- +# cache_peer parent.foo.net parent 3128 3130 default +# cache_peer sib1.foo.net sibling 3128 3130 proxy-only +# cache_peer sib2.foo.net sibling 3128 3130 proxy-only +# cache_peer example.com parent 80 0 default +# cache_peer cdn.example.com sibling 3128 0 +# +# type: either 'parent', 'sibling', or 'multicast'. +# +# proxy-port: The port number where the peer accept HTTP requests. +# For other Squid proxies this is usually 3128 +# For web servers this is usually 80 +# +# icp-port: Used for querying neighbor caches about objects. +# Set to 0 if the peer does not support ICP or HTCP. +# See ICP and HTCP options below for additional details. +# +# +# ==== ICP OPTIONS ==== +# +# You MUST also set icp_port and icp_access explicitly when using these options. +# The defaults will prevent peer traffic using ICP. +# +# +# no-query Disable ICP queries to this neighbor. +# +# multicast-responder +# Indicates the named peer is a member of a multicast group. +# ICP queries will not be sent directly to the peer, but ICP +# replies will be accepted from it. +# +# closest-only Indicates that, for ICP_OP_MISS replies, we'll only forward +# CLOSEST_PARENT_MISSes and never FIRST_PARENT_MISSes. +# +# background-ping +# To only send ICP queries to this neighbor infrequently. +# This is used to keep the neighbor round trip time updated +# and is usually used in conjunction with weighted-round-robin. +# +# +# ==== HTCP OPTIONS ==== +# +# You MUST also set htcp_port and htcp_access explicitly when using these options. +# The defaults will prevent peer traffic using HTCP. +# +# +# htcp Send HTCP, instead of ICP, queries to the neighbor. +# You probably also want to set the "icp-port" to 4827 +# instead of 3130. This directive accepts a comma separated +# list of options described below. +# +# htcp=oldsquid Send HTCP to old Squid versions (2.5 or earlier). +# +# htcp=no-clr Send HTCP to the neighbor but without +# sending any CLR requests. This cannot be used with +# only-clr. +# +# htcp=only-clr Send HTCP to the neighbor but ONLY CLR requests. +# This cannot be used with no-clr. +# +# htcp=no-purge-clr +# Send HTCP to the neighbor including CLRs but only when +# they do not result from PURGE requests. +# +# htcp=forward-clr +# Forward any HTCP CLR requests this proxy receives to the peer. +# +# +# ==== PEER SELECTION METHODS ==== +# +# The default peer selection method is ICP, with the first responding peer +# being used as source. These options can be used for better load balancing. +# +# +# default This is a parent cache which can be used as a "last-resort" +# if a peer cannot be located by any of the peer-selection methods. +# If specified more than once, only the first is used. +# +# round-robin Load-Balance parents which should be used in a round-robin +# fashion in the absence of any ICP queries. +# weight=N can be used to add bias. +# +# weighted-round-robin +# Load-Balance parents which should be used in a round-robin +# fashion with the frequency of each parent being based on the +# round trip time. Closer parents are used more often. +# Usually used for background-ping parents. +# weight=N can be used to add bias. +# +# carp Load-Balance parents which should be used as a CARP array. +# The requests will be distributed among the parents based on the +# CARP load balancing hash function based on their weight. +# +# userhash Load-balance parents based on the client proxy_auth or ident username. +# +# sourcehash Load-balance parents based on the client source IP. +# +# multicast-siblings +# To be used only for cache peers of type "multicast". +# ALL members of this multicast group have "sibling" +# relationship with it, not "parent". This is to a multicast +# group when the requested object would be fetched only from +# a "parent" cache, anyway. It's useful, e.g., when +# configuring a pool of redundant Squid proxies, being +# members of the same multicast group. +# +# +# ==== PEER SELECTION OPTIONS ==== +# +# weight=N use to affect the selection of a peer during any weighted +# peer-selection mechanisms. +# The weight must be an integer; default is 1, +# larger weights are favored more. +# This option does not affect parent selection if a peering +# protocol is not in use. +# +# basetime=N Specify a base amount to be subtracted from round trip +# times of parents. +# It is subtracted before division by weight in calculating +# which parent to fectch from. If the rtt is less than the +# base time the rtt is set to a minimal value. +# +# ttl=N Specify a TTL to use when sending multicast ICP queries +# to this address. +# Only useful when sending to a multicast group. +# Because we don't accept ICP replies from random +# hosts, you must configure other group members as +# peers with the 'multicast-responder' option. +# +# no-delay To prevent access to this neighbor from influencing the +# delay pools. +# +# digest-url=URL Tell Squid to fetch the cache digest (if digests are +# enabled) for this host from the specified URL rather +# than the Squid default location. +# +# +# ==== CARP OPTIONS ==== +# +# carp-key=key-specification +# use a different key than the full URL to hash against the peer. +# the key-specification is a comma-separated list of the keywords +# scheme, host, port, path, params +# Order is not important. +# +# ==== ACCELERATOR / REVERSE-PROXY OPTIONS ==== +# +# originserver Causes this parent to be contacted as an origin server. +# Meant to be used in accelerator setups when the peer +# is a web server. +# +# forceddomain=name +# Set the Host header of requests forwarded to this peer. +# Useful in accelerator setups where the server (peer) +# expects a certain domain name but clients may request +# others. ie example.com or www.example.com +# +# no-digest Disable request of cache digests. +# +# no-netdb-exchange +# Disables requesting ICMP RTT database (NetDB). +# +# +# ==== AUTHENTICATION OPTIONS ==== +# +# login=user:password +# If this is a personal/workgroup proxy and your parent +# requires proxy authentication. +# +# Note: The string can include URL escapes (i.e. %20 for +# spaces). This also means % must be written as %%. +# +# login=PASSTHRU +# Send login details received from client to this peer. +# Both Proxy- and WWW-Authorization headers are passed +# without alteration to the peer. +# Authentication is not required by Squid for this to work. +# +# Note: This will pass any form of authentication but +# only Basic auth will work through a proxy unless the +# connection-auth options are also used. +# +# login=PASS Send login details received from client to this peer. +# Authentication is not required by this option. +# +# If there are no client-provided authentication headers +# to pass on, but username and password are available +# from an external ACL user= and password= result tags +# they may be sent instead. +# +# Note: To combine this with proxy_auth both proxies must +# share the same user database as HTTP only allows for +# a single login (one for proxy, one for origin server). +# Also be warned this will expose your users proxy +# password to the peer. USE WITH CAUTION +# +# login=*:password +# Send the username to the upstream cache, but with a +# fixed password. This is meant to be used when the peer +# is in another administrative domain, but it is still +# needed to identify each user. +# The star can optionally be followed by some extra +# information which is added to the username. This can +# be used to identify this proxy to the peer, similar to +# the login=username:password option above. +# +# login=NEGOTIATE +# If this is a personal/workgroup proxy and your parent +# requires a secure proxy authentication. +# The first principal from the default keytab or defined by +# the environment variable KRB5_KTNAME will be used. +# +# WARNING: The connection may transmit requests from multiple +# clients. Negotiate often assumes end-to-end authentication +# and a single-client. Which is not strictly true here. +# +# login=NEGOTIATE:principal_name +# If this is a personal/workgroup proxy and your parent +# requires a secure proxy authentication. +# The principal principal_name from the default keytab or +# defined by the environment variable KRB5_KTNAME will be +# used. +# +# WARNING: The connection may transmit requests from multiple +# clients. Negotiate often assumes end-to-end authentication +# and a single-client. Which is not strictly true here. +# +# connection-auth=on|off +# Tell Squid that this peer does or not support Microsoft +# connection oriented authentication, and any such +# challenges received from there should be ignored. +# Default is auto to automatically determine the status +# of the peer. +# +# +# ==== SSL / HTTPS / TLS OPTIONS ==== +# +# ssl Encrypt connections to this peer with SSL/TLS. +# +# sslcert=/path/to/ssl/certificate +# A client SSL certificate to use when connecting to +# this peer. +# +# sslkey=/path/to/ssl/key +# The private SSL key corresponding to sslcert above. +# If 'sslkey' is not specified 'sslcert' is assumed to +# reference a combined file containing both the +# certificate and the key. +# +# sslversion=1|2|3|4|5|6 +# The SSL version to use when connecting to this peer +# 1 = automatic (default) +# 2 = SSL v2 only +# 3 = SSL v3 only +# 4 = TLS v1.0 only +# 5 = TLS v1.1 only +# 6 = TLS v1.2 only +# +# sslcipher=... The list of valid SSL ciphers to use when connecting +# to this peer. +# +# ssloptions=... Specify various SSL implementation options: +# +# NO_SSLv2 Disallow the use of SSLv2 +# NO_SSLv3 Disallow the use of SSLv3 +# NO_TLSv1 Disallow the use of TLSv1.0 +# NO_TLSv1_1 Disallow the use of TLSv1.1 +# NO_TLSv1_2 Disallow the use of TLSv1.2 +# +# SINGLE_DH_USE +# Always create a new key when using +# temporary/ephemeral DH key exchanges +# +# NO_TICKET +# Disable use of RFC5077 session tickets. Some servers +# may have problems understanding the TLS extension due +# to ambiguous specification in RFC4507. +# +# ALL Enable various bug workarounds +# suggested as "harmless" by OpenSSL +# Be warned that this reduces SSL/TLS +# strength to some attacks. +# +# See the OpenSSL SSL_CTX_set_options documentation for a +# more complete list. +# +# sslcafile=... A file containing additional CA certificates to use +# when verifying the peer certificate. +# +# sslcapath=... A directory containing additional CA certificates to +# use when verifying the peer certificate. +# +# sslcrlfile=... A certificate revocation list file to use when +# verifying the peer certificate. +# +# sslflags=... Specify various flags modifying the SSL implementation: +# +# DONT_VERIFY_PEER +# Accept certificates even if they fail to +# verify. +# NO_DEFAULT_CA +# Don't use the default CA list built in +# to OpenSSL. +# DONT_VERIFY_DOMAIN +# Don't verify the peer certificate +# matches the server name +# +# ssldomain= The peer name as advertised in it's certificate. +# Used for verifying the correctness of the received peer +# certificate. If not specified the peer hostname will be +# used. +# +# front-end-https +# Enable the "Front-End-Https: On" header needed when +# using Squid as a SSL frontend in front of Microsoft OWA. +# See MS KB document Q307347 for details on this header. +# If set to auto the header will only be added if the +# request is forwarded as a https:// URL. +# +# +# ==== GENERAL OPTIONS ==== +# +# connect-timeout=N +# A peer-specific connect timeout. +# Also see the peer_connect_timeout directive. +# +# connect-fail-limit=N +# How many times connecting to a peer must fail before +# it is marked as down. Standby connection failures +# count towards this limit. Default is 10. +# +# allow-miss Disable Squid's use of only-if-cached when forwarding +# requests to siblings. This is primarily useful when +# icp_hit_stale is used by the sibling. Excessive use +# of this option may result in forwarding loops. One way +# to prevent peering loops when using this option, is to +# deny cache peer usage on requests from a peer: +# acl fromPeer ... +# cache_peer_access peerName deny fromPeer +# +# max-conn=N Limit the number of concurrent connections the Squid +# may open to this peer, including already opened idle +# and standby connections. There is no peer-specific +# connection limit by default. +# +# A peer exceeding the limit is not used for new +# requests unless a standby connection is available. +# +# max-conn currently works poorly with idle persistent +# connections: When a peer reaches its max-conn limit, +# and there are idle persistent connections to the peer, +# the peer may not be selected because the limiting code +# does not know whether Squid can reuse those idle +# connections. +# +# standby=N Maintain a pool of N "hot standby" connections to an +# UP peer, available for requests when no idle +# persistent connection is available (or safe) to use. +# By default and with zero N, no such pool is maintained. +# N must not exceed the max-conn limit (if any). +# +# At start or after reconfiguration, Squid opens new TCP +# standby connections until there are N connections +# available and then replenishes the standby pool as +# opened connections are used up for requests. A used +# connection never goes back to the standby pool, but +# may go to the regular idle persistent connection pool +# shared by all peers and origin servers. +# +# Squid never opens multiple new standby connections +# concurrently. This one-at-a-time approach minimizes +# flooding-like effect on peers. Furthermore, just a few +# standby connections should be sufficient in most cases +# to supply most new requests with a ready-to-use +# connection. +# +# Standby connections obey server_idle_pconn_timeout. +# For the feature to work as intended, the peer must be +# configured to accept and keep them open longer than +# the idle timeout at the connecting Squid, to minimize +# race conditions typical to idle used persistent +# connections. Default request_timeout and +# server_idle_pconn_timeout values ensure such a +# configuration. +# +# name=xxx Unique name for the peer. +# Required if you have multiple peers on the same host +# but different ports. +# This name can be used in cache_peer_access and similar +# directives to identify the peer. +# Can be used by outgoing access controls through the +# peername ACL type. +# +# no-tproxy Do not use the client-spoof TPROXY support when forwarding +# requests to this peer. Use normal address selection instead. +# This overrides the spoof_client_ip ACL. +# +# proxy-only objects fetched from the peer will not be stored locally. +# +#Default: +# none + +# TAG: cache_peer_domain +# Use to limit the domains for which a neighbor cache will be +# queried. +# +# Usage: +# cache_peer_domain cache-host domain [domain ...] +# cache_peer_domain cache-host !domain +# +# For example, specifying +# +# cache_peer_domain parent.foo.net .edu +# +# has the effect such that UDP query packets are sent to +# 'bigserver' only when the requested object exists on a +# server in the .edu domain. Prefixing the domainname +# with '!' means the cache will be queried for objects +# NOT in that domain. +# +# NOTE: * Any number of domains may be given for a cache-host, +# either on the same or separate lines. +# * When multiple domains are given for a particular +# cache-host, the first matched domain is applied. +# * Cache hosts with no domain restrictions are queried +# for all requests. +# * There are no defaults. +# * There is also a 'cache_peer_access' tag in the ACL +# section. +#Default: +# none + +# TAG: cache_peer_access +# Restricts usage of cache_peer proxies. +# +# Usage: +# cache_peer_access peer-name allow|deny [!]aclname ... +# +# For the required peer-name parameter, use either the value of the +# cache_peer name=value parameter or, if name=value is missing, the +# cache_peer hostname parameter. +# +# This directive narrows down the selection of peering candidates, but +# does not determine the order in which the selected candidates are +# contacted. That order is determined by the peer selection algorithms +# (see PEER SELECTION sections in the cache_peer documentation). +# +# If a deny rule matches, the corresponding peer will not be contacted +# for the current transaction -- Squid will not send ICP queries and +# will not forward HTTP requests to that peer. An allow match leaves +# the corresponding peer in the selection. The first match for a given +# peer wins for that peer. +# +# The relative order of cache_peer_access directives for the same peer +# matters. The relative order of any two cache_peer_access directives +# for different peers does not matter. To ease interpretation, it is a +# good idea to group cache_peer_access directives for the same peer +# together. +# +# A single cache_peer_access directive may be evaluated multiple times +# for a given transaction because individual peer selection algorithms +# may check it independently from each other. These redundant checks +# may be optimized away in future Squid versions. +# +# This clause only supports fast acl types. +# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details. +#Default: +# No peer usage restrictions. + +# TAG: neighbor_type_domain +# Modify the cache_peer neighbor type when passing requests +# about specific domains to the peer. +# +# Usage: +# neighbor_type_domain neighbor parent|sibling domain domain ... +# +# For example: +# cache_peer foo.example.com parent 3128 3130 +# neighbor_type_domain foo.example.com sibling .au .de +# +# The above configuration treats all requests to foo.example.com as a +# parent proxy unless the request is for a .au or .de ccTLD domain name. +#Default: +# The peer type from cache_peer directive is used for all requests to that peer. + +# TAG: dead_peer_timeout (seconds) +# This controls how long Squid waits to declare a peer cache +# as "dead." If there are no ICP replies received in this +# amount of time, Squid will declare the peer dead and not +# expect to receive any further ICP replies. However, it +# continues to send ICP queries, and will mark the peer as +# alive upon receipt of the first subsequent ICP reply. +# +# This timeout also affects when Squid expects to receive ICP +# replies from peers. If more than 'dead_peer' seconds have +# passed since the last ICP reply was received, Squid will not +# expect to receive an ICP reply on the next query. Thus, if +# your time between requests is greater than this timeout, you +# will see a lot of requests sent DIRECT to origin servers +# instead of to your parents. +#Default: +# dead_peer_timeout 10 seconds + +# TAG: forward_max_tries +# Controls how many different forward paths Squid will try +# before giving up. See also forward_timeout. +# +# NOTE: connect_retries (default: none) can make each of these +# possible forwarding paths be tried multiple times. +#Default: +# forward_max_tries 25 + +# MEMORY CACHE OPTIONS +# ----------------------------------------------------------------------------- + +# TAG: cache_mem (bytes) +# NOTE: THIS PARAMETER DOES NOT SPECIFY THE MAXIMUM PROCESS SIZE. +# IT ONLY PLACES A LIMIT ON HOW MUCH ADDITIONAL MEMORY SQUID WILL +# USE AS A MEMORY CACHE OF OBJECTS. SQUID USES MEMORY FOR OTHER +# THINGS AS WELL. SEE THE SQUID FAQ SECTION 8 FOR DETAILS. +# +# 'cache_mem' specifies the ideal amount of memory to be used +# for: +# * In-Transit objects +# * Hot Objects +# * Negative-Cached objects +# +# Data for these objects are stored in 4 KB blocks. This +# parameter specifies the ideal upper limit on the total size of +# 4 KB blocks allocated. In-Transit objects take the highest +# priority. +# +# In-transit objects have priority over the others. When +# additional space is needed for incoming data, negative-cached +# and hot objects will be released. In other words, the +# negative-cached and hot objects will fill up any unused space +# not needed for in-transit objects. +# +# If circumstances require, this limit will be exceeded. +# Specifically, if your incoming request rate requires more than +# 'cache_mem' of memory to hold in-transit objects, Squid will +# exceed this limit to satisfy the new requests. When the load +# decreases, blocks will be freed until the high-water mark is +# reached. Thereafter, blocks will be used to store hot +# objects. +# +# If shared memory caching is enabled, Squid does not use the shared +# cache space for in-transit objects, but they still consume as much +# local memory as they need. For more details about the shared memory +# cache, see memory_cache_shared. +#Default: +# cache_mem 256 MB + +# TAG: maximum_object_size_in_memory (bytes) +# Objects greater than this size will not be attempted to kept in +# the memory cache. This should be set high enough to keep objects +# accessed frequently in memory to improve performance whilst low +# enough to keep larger objects from hoarding cache_mem. +#Default: +# maximum_object_size_in_memory 512 KB + +# TAG: memory_cache_shared on|off +# Controls whether the memory cache is shared among SMP workers. +# +# The shared memory cache is meant to occupy cache_mem bytes and replace +# the non-shared memory cache, although some entities may still be +# cached locally by workers for now (e.g., internal and in-transit +# objects may be served from a local memory cache even if shared memory +# caching is enabled). +# +# By default, the memory cache is shared if and only if all of the +# following conditions are satisfied: Squid runs in SMP mode with +# multiple workers, cache_mem is positive, and Squid environment +# supports required IPC primitives (e.g., POSIX shared memory segments +# and GCC-style atomic operations). +# +# To avoid blocking locks, shared memory uses opportunistic algorithms +# that do not guarantee that every cachable entity that could have been +# shared among SMP workers will actually be shared. +#Default: +# "on" where supported if doing memory caching with multiple SMP workers. + +# TAG: memory_cache_mode +# Controls which objects to keep in the memory cache (cache_mem) +# +# always Keep most recently fetched objects in memory (default) +# +# disk Only disk cache hits are kept in memory, which means +# an object must first be cached on disk and then hit +# a second time before cached in memory. +# +# network Only objects fetched from network is kept in memory +#Default: +# Keep the most recently fetched objects in memory + +# TAG: memory_replacement_policy +# The memory replacement policy parameter determines which +# objects are purged from memory when memory space is needed. +# +# See cache_replacement_policy for details on algorithms. +#Default: +# memory_replacement_policy lru + +# DISK CACHE OPTIONS +# ----------------------------------------------------------------------------- + +# TAG: cache_replacement_policy +# The cache replacement policy parameter determines which +# objects are evicted (replaced) when disk space is needed. +# +# lru : Squid's original list based LRU policy +# heap GDSF : Greedy-Dual Size Frequency +# heap LFUDA: Least Frequently Used with Dynamic Aging +# heap LRU : LRU policy implemented using a heap +# +# Applies to any cache_dir lines listed below this directive. +# +# The LRU policies keeps recently referenced objects. +# +# The heap GDSF policy optimizes object hit rate by keeping smaller +# popular objects in cache so it has a better chance of getting a +# hit. It achieves a lower byte hit rate than LFUDA though since +# it evicts larger (possibly popular) objects. +# +# The heap LFUDA policy keeps popular objects in cache regardless of +# their size and thus optimizes byte hit rate at the expense of +# hit rate since one large, popular object will prevent many +# smaller, slightly less popular objects from being cached. +# +# Both policies utilize a dynamic aging mechanism that prevents +# cache pollution that can otherwise occur with frequency-based +# replacement policies. +# +# NOTE: if using the LFUDA replacement policy you should increase +# the value of maximum_object_size above its default of 4 MB to +# to maximize the potential byte hit rate improvement of LFUDA. +# +# For more information about the GDSF and LFUDA cache replacement +# policies see http://www.hpl.hp.com/techreports/1999/HPL-1999-69.html +# and http://fog.hpl.external.hp.com/techreports/98/HPL-98-173.html. +#Default: +# cache_replacement_policy lru + +# TAG: minimum_object_size (bytes) +# Objects smaller than this size will NOT be saved on disk. The +# value is specified in bytes, and the default is 0 KB, which +# means all responses can be stored. +#Default: +# no limit + +# TAG: maximum_object_size (bytes) +# Set the default value for max-size parameter on any cache_dir. +# The value is specified in bytes, and the default is 4 MB. +# +# If you wish to get a high BYTES hit ratio, you should probably +# increase this (one 32 MB object hit counts for 3200 10KB +# hits). +# +# If you wish to increase hit ratio more than you want to +# save bandwidth you should leave this low. +# +# NOTE: if using the LFUDA replacement policy you should increase +# this value to maximize the byte hit rate improvement of LFUDA! +# See cache_replacement_policy for a discussion of this policy. +#Default: +maximum_object_size 500 MB + +# TAG: cache_dir +# Format: +# cache_dir Type Directory-Name Fs-specific-data [options] +# +# You can specify multiple cache_dir lines to spread the +# cache among different disk partitions. +# +# Type specifies the kind of storage system to use. Only "ufs" +# is built by default. To enable any of the other storage systems +# see the --enable-storeio configure option. +# +# 'Directory' is a top-level directory where cache swap +# files will be stored. If you want to use an entire disk +# for caching, this can be the mount-point directory. +# The directory must exist and be writable by the Squid +# process. Squid will NOT create this directory for you. +# +# In SMP configurations, cache_dir must not precede the workers option +# and should use configuration macros or conditionals to give each +# worker interested in disk caching a dedicated cache directory. +# +# +# ==== The ufs store type ==== +# +# "ufs" is the old well-known Squid storage format that has always +# been there. +# +# Usage: +# cache_dir ufs Directory-Name Mbytes L1 L2 [options] +# +# 'Mbytes' is the amount of disk space (MB) to use under this +# directory. The default is 100 MB. Change this to suit your +# configuration. Do NOT put the size of your disk drive here. +# Instead, if you want Squid to use the entire disk drive, +# subtract 20% and use that value. +# +# 'L1' is the number of first-level subdirectories which +# will be created under the 'Directory'. The default is 16. +# +# 'L2' is the number of second-level subdirectories which +# will be created under each first-level directory. The default +# is 256. +# +# +# ==== The aufs store type ==== +# +# "aufs" uses the same storage format as "ufs", utilizing +# POSIX-threads to avoid blocking the main Squid process on +# disk-I/O. This was formerly known in Squid as async-io. +# +# Usage: +# cache_dir aufs Directory-Name Mbytes L1 L2 [options] +# +# see argument descriptions under ufs above +# +# +# ==== The diskd store type ==== +# +# "diskd" uses the same storage format as "ufs", utilizing a +# separate process to avoid blocking the main Squid process on +# disk-I/O. +# +# Usage: +# cache_dir diskd Directory-Name Mbytes L1 L2 [options] [Q1=n] [Q2=n] +# +# see argument descriptions under ufs above +# +# Q1 specifies the number of unacknowledged I/O requests when Squid +# stops opening new files. If this many messages are in the queues, +# Squid won't open new files. Default is 64 +# +# Q2 specifies the number of unacknowledged messages when Squid +# starts blocking. If this many messages are in the queues, +# Squid blocks until it receives some replies. Default is 72 +# +# When Q1 < Q2 (the default), the cache directory is optimized +# for lower response time at the expense of a decrease in hit +# ratio. If Q1 > Q2, the cache directory is optimized for +# higher hit ratio at the expense of an increase in response +# time. +# +# +# ==== The rock store type ==== +# +# Usage: +# cache_dir rock Directory-Name Mbytes [options] +# +# The Rock Store type is a database-style storage. All cached +# entries are stored in a "database" file, using fixed-size slots. +# A single entry occupies one or more slots. +# +# If possible, Squid using Rock Store creates a dedicated kid +# process called "disker" to avoid blocking Squid worker(s) on disk +# I/O. One disker kid is created for each rock cache_dir. Diskers +# are created only when Squid, running in daemon mode, has support +# for the IpcIo disk I/O module. +# +# swap-timeout=msec: Squid will not start writing a miss to or +# reading a hit from disk if it estimates that the swap operation +# will take more than the specified number of milliseconds. By +# default and when set to zero, disables the disk I/O time limit +# enforcement. Ignored when using blocking I/O module because +# blocking synchronous I/O does not allow Squid to estimate the +# expected swap wait time. +# +# max-swap-rate=swaps/sec: Artificially limits disk access using +# the specified I/O rate limit. Swap out requests that +# would cause the average I/O rate to exceed the limit are +# delayed. Individual swap in requests (i.e., hits or reads) are +# not delayed, but they do contribute to measured swap rate and +# since they are placed in the same FIFO queue as swap out +# requests, they may wait longer if max-swap-rate is smaller. +# This is necessary on file systems that buffer "too +# many" writes and then start blocking Squid and other processes +# while committing those writes to disk. Usually used together +# with swap-timeout to avoid excessive delays and queue overflows +# when disk demand exceeds available disk "bandwidth". By default +# and when set to zero, disables the disk I/O rate limit +# enforcement. Currently supported by IpcIo module only. +# +# slot-size=bytes: The size of a database "record" used for +# storing cached responses. A cached response occupies at least +# one slot and all database I/O is done using individual slots so +# increasing this parameter leads to more disk space waste while +# decreasing it leads to more disk I/O overheads. Should be a +# multiple of your operating system I/O page size. Defaults to +# 16KBytes. A housekeeping header is stored with each slot and +# smaller slot-sizes will be rejected. The header is smaller than +# 100 bytes. +# +# +# ==== COMMON OPTIONS ==== +# +# no-store no new objects should be stored to this cache_dir. +# +# min-size=n the minimum object size in bytes this cache_dir +# will accept. It's used to restrict a cache_dir +# to only store large objects (e.g. AUFS) while +# other stores are optimized for smaller objects +# (e.g. Rock). +# Defaults to 0. +# +# max-size=n the maximum object size in bytes this cache_dir +# supports. +# The value in maximum_object_size directive sets +# the default unless more specific details are +# available (ie a small store capacity). +# +# Note: To make optimal use of the max-size limits you should order +# the cache_dir lines with the smallest max-size value first. +# +#Default: +# No disk cache. Store cache ojects only in memory. +# + +# Uncomment and adjust the following to add a disk cache directory. +cache_dir ufs /var/spool/squid 50000 16 256 + +# TAG: store_dir_select_algorithm +# How Squid selects which cache_dir to use when the response +# object will fit into more than one. +# +# Regardless of which algorithm is used the cache_dir min-size +# and max-size parameters are obeyed. As such they can affect +# the selection algorithm by limiting the set of considered +# cache_dir. +# +# Algorithms: +# +# least-load +# +# This algorithm is suited to caches with similar cache_dir +# sizes and disk speeds. +# +# The disk with the least I/O pending is selected. +# When there are multiple disks with the same I/O load ranking +# the cache_dir with most available capacity is selected. +# +# When a mix of cache_dir sizes are configured the faster disks +# have a naturally lower I/O loading and larger disks have more +# capacity. So space used to store objects and data throughput +# may be very unbalanced towards larger disks. +# +# +# round-robin +# +# This algorithm is suited to caches with unequal cache_dir +# disk sizes. +# +# Each cache_dir is selected in a rotation. The next suitable +# cache_dir is used. +# +# Available cache_dir capacity is only considered in relation +# to whether the object will fit and meets the min-size and +# max-size parameters. +# +# Disk I/O loading is only considered to prevent overload on slow +# disks. This algorithm does not spread objects by size, so any +# I/O loading per-disk may appear very unbalanced and volatile. +# +# If several cache_dirs use similar min-size, max-size, or other +# limits to to reject certain responses, then do not group such +# cache_dir lines together, to avoid round-robin selection bias +# towards the first cache_dir after the group. Instead, interleave +# cache_dir lines from different groups. For example: +# +# store_dir_select_algorithm round-robin +# cache_dir rock /hdd1 ... min-size=100000 +# cache_dir rock /ssd1 ... max-size=99999 +# cache_dir rock /hdd2 ... min-size=100000 +# cache_dir rock /ssd2 ... max-size=99999 +# cache_dir rock /hdd3 ... min-size=100000 +# cache_dir rock /ssd3 ... max-size=99999 +#Default: +# store_dir_select_algorithm least-load + +# TAG: max_open_disk_fds +# To avoid having disk as the I/O bottleneck Squid can optionally +# bypass the on-disk cache if more than this amount of disk file +# descriptors are open. +# +# A value of 0 indicates no limit. +#Default: +# no limit + +# TAG: cache_swap_low (percent, 0-100) +# The low-water mark for AUFS/UFS/diskd cache object eviction by +# the cache_replacement_policy algorithm. +# +# Removal begins when the swap (disk) usage of a cache_dir is +# above this low-water mark and attempts to maintain utilization +# near the low-water mark. +# +# As swap utilization increases towards the high-water mark set +# by cache_swap_high object eviction becomes more agressive. +# +# The value difference in percentages between low- and high-water +# marks represent an eviction rate of 300 objects per second and +# the rate continues to scale in agressiveness by multiples of +# this above the high-water mark. +# +# Defaults are 90% and 95%. If you have a large cache, 5% could be +# hundreds of MB. If this is the case you may wish to set these +# numbers closer together. +# +# See also cache_swap_high and cache_replacement_policy +#Default: +# cache_swap_low 90 + +# TAG: cache_swap_high (percent, 0-100) +# The high-water mark for AUFS/UFS/diskd cache object eviction by +# the cache_replacement_policy algorithm. +# +# Removal begins when the swap (disk) usage of a cache_dir is +# above the low-water mark set by cache_swap_low and attempts to +# maintain utilization near the low-water mark. +# +# As swap utilization increases towards this high-water mark object +# eviction becomes more agressive. +# +# The value difference in percentages between low- and high-water +# marks represent an eviction rate of 300 objects per second and +# the rate continues to scale in agressiveness by multiples of +# this above the high-water mark. +# +# Defaults are 90% and 95%. If you have a large cache, 5% could be +# hundreds of MB. If this is the case you may wish to set these +# numbers closer together. +# +# See also cache_swap_low and cache_replacement_policy +#Default: +# cache_swap_high 95 + +# LOGFILE OPTIONS +# ----------------------------------------------------------------------------- + +# TAG: logformat +# Usage: +# +# logformat <name> <format specification> +# +# Defines an access log format. +# +# The <format specification> is a string with embedded % format codes +# +# % format codes all follow the same basic structure where all but +# the formatcode is optional. Output strings are automatically escaped +# as required according to their context and the output format +# modifiers are usually not needed, but can be specified if an explicit +# output format is desired. +# +# % ["|[|'|#] [-] [[0]width] [{argument}] formatcode +# +# " output in quoted string format +# [ output in squid text log format as used by log_mime_hdrs +# # output in URL quoted format +# ' output as-is +# +# - left aligned +# +# width minimum and/or maximum field width: +# [width_min][.width_max] +# When minimum starts with 0, the field is zero-padded. +# String values exceeding maximum width are truncated. +# +# {arg} argument such as header name etc +# +# Format codes: +# +# % a literal % character +# sn Unique sequence number per log line entry +# err_code The ID of an error response served by Squid or +# a similar internal error identifier. +# err_detail Additional err_code-dependent error information. +# note The annotation specified by the argument. Also +# logs the adaptation meta headers set by the +# adaptation_meta configuration parameter. +# If no argument given all annotations logged. +# The argument may include a separator to use with +# annotation values: +# name[:separator] +# By default, multiple note values are separated with "," +# and multiple notes are separated with "\r\n". +# When logging named notes with %{name}note, the +# explicitly configured separator is used between note +# values. When logging all notes with %note, the +# explicitly configured separator is used between +# individual notes. There is currently no way to +# specify both value and notes separators when logging +# all notes with %note. +# +# Connection related format codes: +# +# >a Client source IP address +# >A Client FQDN +# >p Client source port +# >eui Client source EUI (MAC address, EUI-48 or EUI-64 identifier) +# >la Local IP address the client connected to +# >lp Local port number the client connected to +# >qos Client connection TOS/DSCP value set by Squid +# >nfmark Client connection netfilter mark set by Squid +# +# la Local listening IP address the client connection was connected to. +# lp Local listening port number the client connection was connected to. +# +# <a Server IP address of the last server or peer connection +# <A Server FQDN or peer name +# <p Server port number of the last server or peer connection +# <la Local IP address of the last server or peer connection +# <lp Local port number of the last server or peer connection +# <qos Server connection TOS/DSCP value set by Squid +# <nfmark Server connection netfilter mark set by Squid +# +# Time related format codes: +# +# ts Seconds since epoch +# tu subsecond time (milliseconds) +# tl Local time. Optional strftime format argument +# default %d/%b/%Y:%H:%M:%S %z +# tg GMT time. Optional strftime format argument +# default %d/%b/%Y:%H:%M:%S %z +# tr Response time (milliseconds) +# dt Total time spent making DNS lookups (milliseconds) +# tS Approximate master transaction start time in +# <full seconds since epoch>.<fractional seconds> format. +# Currently, Squid considers the master transaction +# started when a complete HTTP request header initiating +# the transaction is received from the client. This is +# the same value that Squid uses to calculate transaction +# response time when logging %tr to access.log. Currently, +# Squid uses millisecond resolution for %tS values, +# similar to the default access.log "current time" field +# (%ts.%03tu). +# +# Access Control related format codes: +# +# et Tag returned by external acl +# ea Log string returned by external acl +# un User name (any available) +# ul User name from authentication +# ue User name from external acl helper +# ui User name from ident +# un A user name. Expands to the first available name +# from the following list of information sources: +# - authenticated user name, like %ul +# - user name supplied by an external ACL, like %ue +# - SSL client name, like %us +# - ident user name, like %ui +# credentials Client credentials. The exact meaning depends on +# the authentication scheme: For Basic authentication, +# it is the password; for Digest, the realm sent by the +# client; for NTLM and Negotiate, the client challenge +# or client credentials prefixed with "YR " or "KK ". +# +# HTTP related format codes: +# +# REQUEST +# +# [http::]rm Request method (GET/POST etc) +# [http::]>rm Request method from client +# [http::]<rm Request method sent to server or peer +# [http::]ru Request URL from client (historic, filtered for logging) +# [http::]>ru Request URL from client +# [http::]<ru Request URL sent to server or peer +# [http::]>rs Request URL scheme from client +# [http::]<rs Request URL scheme sent to server or peer +# [http::]>rd Request URL domain from client +# [http::]<rd Request URL domain sent to server or peer +# [http::]>rP Request URL port from client +# [http::]<rP Request URL port sent to server or peer +# [http::]rp Request URL path excluding hostname +# [http::]>rp Request URL path excluding hostname from client +# [http::]<rp Request URL path excluding hostname sent to server or peer +# [http::]rv Request protocol version +# [http::]>rv Request protocol version from client +# [http::]<rv Request protocol version sent to server or peer +# +# [http::]>h Original received request header. +# Usually differs from the request header sent by +# Squid, although most fields are often preserved. +# Accepts optional header field name/value filter +# argument using name[:[separator]element] format. +# [http::]>ha Received request header after adaptation and +# redirection (pre-cache REQMOD vectoring point). +# Usually differs from the request header sent by +# Squid, although most fields are often preserved. +# Optional header name argument as for >h +# +# +# RESPONSE +# +# [http::]<Hs HTTP status code received from the next hop +# [http::]>Hs HTTP status code sent to the client +# +# [http::]<h Reply header. Optional header name argument +# as for >h +# +# [http::]mt MIME content type +# +# +# SIZE COUNTERS +# +# [http::]st Total size of request + reply traffic with client +# [http::]>st Total size of request received from client. +# Excluding chunked encoding bytes. +# [http::]<st Total size of reply sent to client (after adaptation) +# +# [http::]>sh Size of request headers received from client +# [http::]<sh Size of reply headers sent to client (after adaptation) +# +# [http::]<sH Reply high offset sent +# [http::]<sS Upstream object size +# +# [http::]<bs Number of HTTP-equivalent message body bytes +# received from the next hop, excluding chunked +# transfer encoding and control messages. +# Generated FTP/Gopher listings are treated as +# received bodies. +# +# +# TIMING +# +# [http::]<pt Peer response time in milliseconds. The timer starts +# when the last request byte is sent to the next hop +# and stops when the last response byte is received. +# [http::]<tt Total time in milliseconds. The timer +# starts with the first connect request (or write I/O) +# sent to the first selected peer. The timer stops +# with the last I/O with the last peer. +# +# Squid handling related format codes: +# +# Ss Squid request status (TCP_MISS etc) +# Sh Squid hierarchy status (DEFAULT_PARENT etc) +# +# SSL-related format codes: +# +# ssl::bump_mode SslBump decision for the transaction: +# +# For CONNECT requests that initiated bumping of +# a connection and for any request received on +# an already bumped connection, Squid logs the +# corresponding SslBump mode ("server-first" or +# "client-first"). See the ssl_bump option for +# more information about these modes. +# +# A "none" token is logged for requests that +# triggered "ssl_bump" ACL evaluation matching +# either a "none" rule or no rules at all. +# +# In all other cases, a single dash ("-") is +# logged. +# +# ssl::>sni SSL client SNI sent to Squid. Available only +# after the peek, stare, or splice SSL bumping +# actions. +# +# If ICAP is enabled, the following code becomes available (as +# well as ICAP log codes documented with the icap_log option): +# +# icap::tt Total ICAP processing time for the HTTP +# transaction. The timer ticks when ICAP +# ACLs are checked and when ICAP +# transaction is in progress. +# +# If adaptation is enabled the following three codes become available: +# +# adapt::<last_h The header of the last ICAP response or +# meta-information from the last eCAP +# transaction related to the HTTP transaction. +# Like <h, accepts an optional header name +# argument. +# +# adapt::sum_trs Summed adaptation transaction response +# times recorded as a comma-separated list in +# the order of transaction start time. Each time +# value is recorded as an integer number, +# representing response time of one or more +# adaptation (ICAP or eCAP) transaction in +# milliseconds. When a failed transaction is +# being retried or repeated, its time is not +# logged individually but added to the +# replacement (next) transaction. See also: +# adapt::all_trs. +# +# adapt::all_trs All adaptation transaction response times. +# Same as adaptation_strs but response times of +# individual transactions are never added +# together. Instead, all transaction response +# times are recorded individually. +# +# You can prefix adapt::*_trs format codes with adaptation +# service name in curly braces to record response time(s) specific +# to that service. For example: %{my_service}adapt::sum_trs +# +# If SSL is enabled, the following formating codes become available: +# +# %ssl::>cert_subject The Subject field of the received client +# SSL certificate or a dash ('-') if Squid has +# received an invalid/malformed certificate or +# no certificate at all. Consider encoding the +# logged value because Subject often has spaces. +# +# %ssl::>cert_issuer The Issuer field of the received client +# SSL certificate or a dash ('-') if Squid has +# received an invalid/malformed certificate or +# no certificate at all. Consider encoding the +# logged value because Issuer often has spaces. +# +# The default formats available (which do not need re-defining) are: +# +#logformat squid %ts.%03tu %6tr %>a %Ss/%03>Hs %<st %rm %ru %[un %Sh/%<a %mt +#logformat common %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st %Ss:%Sh +#logformat combined %>a %[ui %[un [%tl] "%rm %ru HTTP/%rv" %>Hs %<st "%{Referer}>h" "%{User-Agent}>h" %Ss:%Sh +#logformat referrer %ts.%03tu %>a %{Referer}>h %ru +#logformat useragent %>a [%tl] "%{User-Agent}>h" +# +# NOTE: When the log_mime_hdrs directive is set to ON. +# The squid, common and combined formats have a safely encoded copy +# of the mime headers appended to each line within a pair of brackets. +# +# NOTE: The common and combined formats are not quite true to the Apache definition. +# The logs from Squid contain an extra status and hierarchy code appended. +# +#Default: +# The format definitions squid, common, combined, referrer, useragent are built in. + +# TAG: access_log +# Configures whether and how Squid logs HTTP and ICP transactions. +# If access logging is enabled, a single line is logged for every +# matching HTTP or ICP request. The recommended directive formats are: +# +# access_log <module>:<place> [option ...] [acl acl ...] +# access_log none [acl acl ...] +# +# The following directive format is accepted but may be deprecated: +# access_log <module>:<place> [<logformat name> [acl acl ...]] +# +# In most cases, the first ACL name must not contain the '=' character +# and should not be equal to an existing logformat name. You can always +# start with an 'all' ACL to work around those restrictions. +# +# Will log to the specified module:place using the specified format (which +# must be defined in a logformat directive) those entries which match +# ALL the acl's specified (which must be defined in acl clauses). +# If no acl is specified, all requests will be logged to this destination. +# +# ===== Available options for the recommended directive format ===== +# +# logformat=name Names log line format (either built-in or +# defined by a logformat directive). Defaults +# to 'squid'. +# +# buffer-size=64KB Defines approximate buffering limit for log +# records (see buffered_logs). Squid should not +# keep more than the specified size and, hence, +# should flush records before the buffer becomes +# full to avoid overflows under normal +# conditions (the exact flushing algorithm is +# module-dependent though). The on-error option +# controls overflow handling. +# +# on-error=die|drop Defines action on unrecoverable errors. The +# 'drop' action ignores (i.e., does not log) +# affected log records. The default 'die' action +# kills the affected worker. The drop action +# support has not been tested for modules other +# than tcp. +# +# ===== Modules Currently available ===== +# +# none Do not log any requests matching these ACL. +# Do not specify Place or logformat name. +# +# stdio Write each log line to disk immediately at the completion of +# each request. +# Place: the filename and path to be written. +# +# daemon Very similar to stdio. But instead of writing to disk the log +# line is passed to a daemon helper for asychronous handling instead. +# Place: varies depending on the daemon. +# +# log_file_daemon Place: the file name and path to be written. +# +# syslog To log each request via syslog facility. +# Place: The syslog facility and priority level for these entries. +# Place Format: facility.priority +# +# where facility could be any of: +# authpriv, daemon, local0 ... local7 or user. +# +# And priority could be any of: +# err, warning, notice, info, debug. +# +# udp To send each log line as text data to a UDP receiver. +# Place: The destination host name or IP and port. +# Place Format: //host:port +# +# tcp To send each log line as text data to a TCP receiver. +# Lines may be accumulated before sending (see buffered_logs). +# Place: The destination host name or IP and port. +# Place Format: //host:port +# +# Default: +# access_log daemon:/var/log/squid/access.log squid +#Default: +# access_log daemon:/var/log/squid/access.log squid + +# TAG: icap_log +# ICAP log files record ICAP transaction summaries, one line per +# transaction. +# +# The icap_log option format is: +# icap_log <filepath> [<logformat name> [acl acl ...]] +# icap_log none [acl acl ...]] +# +# Please see access_log option documentation for details. The two +# kinds of logs share the overall configuration approach and many +# features. +# +# ICAP processing of a single HTTP message or transaction may +# require multiple ICAP transactions. In such cases, multiple +# ICAP transaction log lines will correspond to a single access +# log line. +# +# ICAP log supports many access.log logformat %codes. In ICAP context, +# HTTP message-related %codes are applied to the HTTP message embedded +# in an ICAP message. Logformat "%http::>..." codes are used for HTTP +# messages embedded in ICAP requests while "%http::<..." codes are used +# for HTTP messages embedded in ICAP responses. For example: +# +# http::>h To-be-adapted HTTP message headers sent by Squid to +# the ICAP service. For REQMOD transactions, these are +# HTTP request headers. For RESPMOD, these are HTTP +# response headers, but Squid currently cannot log them +# (i.e., %http::>h will expand to "-" for RESPMOD). +# +# http::<h Adapted HTTP message headers sent by the ICAP +# service to Squid (i.e., HTTP request headers in regular +# REQMOD; HTTP response headers in RESPMOD and during +# request satisfaction in REQMOD). +# +# ICAP OPTIONS transactions do not embed HTTP messages. +# +# Several logformat codes below deal with ICAP message bodies. An ICAP +# message body, if any, typically includes a complete HTTP message +# (required HTTP headers plus optional HTTP message body). When +# computing HTTP message body size for these logformat codes, Squid +# either includes or excludes chunked encoding overheads; see +# code-specific documentation for details. +# +# For Secure ICAP services, all size-related information is currently +# computed before/after TLS encryption/decryption, as if TLS was not +# in use at all. +# +# The following format codes are also available for ICAP logs: +# +# icap::<A ICAP server IP address. Similar to <A. +# +# icap::<service_name ICAP service name from the icap_service +# option in Squid configuration file. +# +# icap::ru ICAP Request-URI. Similar to ru. +# +# icap::rm ICAP request method (REQMOD, RESPMOD, or +# OPTIONS). Similar to existing rm. +# +# icap::>st The total size of the ICAP request sent to the ICAP +# server (ICAP headers + ICAP body), including chunking +# metadata (if any). +# +# icap::<st The total size of the ICAP response received from the +# ICAP server (ICAP headers + ICAP body), including +# chunking metadata (if any). +# +# icap::<bs The size of the ICAP response body received from the +# ICAP server, excluding chunking metadata (if any). +# +# icap::tr Transaction response time (in +# milliseconds). The timer starts when +# the ICAP transaction is created and +# stops when the transaction is completed. +# Similar to tr. +# +# icap::tio Transaction I/O time (in milliseconds). The +# timer starts when the first ICAP request +# byte is scheduled for sending. The timers +# stops when the last byte of the ICAP response +# is received. +# +# icap::to Transaction outcome: ICAP_ERR* for all +# transaction errors, ICAP_OPT for OPTION +# transactions, ICAP_ECHO for 204 +# responses, ICAP_MOD for message +# modification, and ICAP_SAT for request +# satisfaction. Similar to Ss. +# +# icap::Hs ICAP response status code. Similar to Hs. +# +# icap::>h ICAP request header(s). Similar to >h. +# +# icap::<h ICAP response header(s). Similar to <h. +# +# The default ICAP log format, which can be used without an explicit +# definition, is called icap_squid: +# +#logformat icap_squid %ts.%03tu %6icap::tr %>A %icap::to/%03icap::Hs %icap::<st %icap::rm %icap::ru %un -/%icap::<A - +# +# See also: logformat and %adapt::<last_h +#Default: +# none + +# TAG: logfile_daemon +# Specify the path to the logfile-writing daemon. This daemon is +# used to write the access and store logs, if configured. +# +# Squid sends a number of commands to the log daemon: +# L<data>\n - logfile data +# R\n - rotate file +# T\n - truncate file +# O\n - reopen file +# F\n - flush file +# r<n>\n - set rotate count to <n> +# b<n>\n - 1 = buffer output, 0 = don't buffer output +# +# No responses is expected. +#Default: +# logfile_daemon /usr/lib/squid/log_file_daemon + +# TAG: stats_collection allow|deny acl acl... +# This options allows you to control which requests gets accounted +# in performance counters. +# +# This clause only supports fast acl types. +# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details. +#Default: +# Allow logging for all transactions. + +# TAG: cache_store_log +# Logs the activities of the storage manager. Shows which +# objects are ejected from the cache, and which objects are +# saved and for how long. +# There are not really utilities to analyze this data, so you can safely +# disable it (the default). +# +# Store log uses modular logging outputs. See access_log for the list +# of modules supported. +# +# Example: + cache_store_log stdio:/var/log/squid/store.log +# cache_store_log daemon:/var/log/squid/store.log +#Default: +# none + +# TAG: cache_swap_state +# Location for the cache "swap.state" file. This index file holds +# the metadata of objects saved on disk. It is used to rebuild +# the cache during startup. Normally this file resides in each +# 'cache_dir' directory, but you may specify an alternate +# pathname here. Note you must give a full filename, not just +# a directory. Since this is the index for the whole object +# list you CANNOT periodically rotate it! +# +# If %s can be used in the file name it will be replaced with a +# a representation of the cache_dir name where each / is replaced +# with '.'. This is needed to allow adding/removing cache_dir +# lines when cache_swap_log is being used. +# +# If have more than one 'cache_dir', and %s is not used in the name +# these swap logs will have names such as: +# +# cache_swap_log.00 +# cache_swap_log.01 +# cache_swap_log.02 +# +# The numbered extension (which is added automatically) +# corresponds to the order of the 'cache_dir' lines in this +# configuration file. If you change the order of the 'cache_dir' +# lines in this file, these index files will NOT correspond to +# the correct 'cache_dir' entry (unless you manually rename +# them). We recommend you do NOT use this option. It is +# better to keep these index files in each 'cache_dir' directory. +#Default: +# Store the journal inside its cache_dir + +# TAG: logfile_rotate +# Specifies the number of logfile rotations to make when you +# type 'squid -k rotate'. The default is 10, which will rotate +# with extensions 0 through 9. Setting logfile_rotate to 0 will +# disable the file name rotation, but the logfiles are still closed +# and re-opened. This will enable you to rename the logfiles +# yourself just before sending the rotate signal. +# +# Note, the 'squid -k rotate' command normally sends a USR1 +# signal to the running squid process. In certain situations +# (e.g. on Linux with Async I/O), USR1 is used for other +# purposes, so -k rotate uses another signal. It is best to get +# in the habit of using 'squid -k rotate' instead of 'kill -USR1 +# <pid>'. +# +# Note, from Squid-3.1 this option is only a default for cache.log, +# that log can be rotated separately by using debug_options. +# +# Note2, for Debian/Linux the default of logfile_rotate is +# zero, since it includes external logfile-rotation methods. +#Default: +# logfile_rotate 0 + +# TAG: mime_table +# Path to Squid's icon configuration file. +# +# You shouldn't need to change this, but the default file contains +# examples and formatting information if you do. +#Default: +# mime_table /usr/share/squid/mime.conf + +# TAG: log_mime_hdrs on|off +# The Cache can record both the request and the response MIME +# headers for each HTTP transaction. The headers are encoded +# safely and will appear as two bracketed fields at the end of +# the access log (for either the native or httpd-emulated log +# formats). To enable this logging set log_mime_hdrs to 'on'. +#Default: +# log_mime_hdrs off + +# TAG: pid_filename +# A filename to write the process-id to. To disable, enter "none". +#Default: +# pid_filename /var/run/squid.pid + +# TAG: client_netmask +# A netmask for client addresses in logfiles and cachemgr output. +# Change this to protect the privacy of your cache clients. +# A netmask of 255.255.255.0 will log all IP's in that range with +# the last digit set to '0'. +#Default: +# Log full client IP address + +# TAG: strip_query_terms +# By default, Squid strips query terms from requested URLs before +# logging. This protects your user's privacy and reduces log size. +# +# When investigating HIT/MISS or other caching behaviour you +# will need to disable this to see the full URL used by Squid. +#Default: +# strip_query_terms on + +# TAG: buffered_logs on|off +# Whether to write/send access_log records ASAP or accumulate them and +# then write/send them in larger chunks. Buffering may improve +# performance because it decreases the number of I/Os. However, +# buffering increases the delay before log records become available to +# the final recipient (e.g., a disk file or logging daemon) and, +# hence, increases the risk of log records loss. +# +# Note that even when buffered_logs are off, Squid may have to buffer +# records if it cannot write/send them immediately due to pending I/Os +# (e.g., the I/O writing the previous log record) or connectivity loss. +# +# Currently honored by 'daemon' and 'tcp' access_log modules only. +#Default: +# buffered_logs off + +# TAG: netdb_filename +# Where Squid stores it's netdb journal. +# When enabled this journal preserves netdb state between restarts. +# +# To disable, enter "none". +#Default: +# netdb_filename stdio:/var/log/squid/netdb.state + +# OPTIONS FOR TROUBLESHOOTING +# ----------------------------------------------------------------------------- + +# TAG: cache_log +# Squid administrative logging file. +# +# This is where general information about Squid behavior goes. You can +# increase the amount of data logged to this file and how often it is +# rotated with "debug_options" +#Default: +cache_log /var/log/squid/cache.log + +# TAG: debug_options +# Logging options are set as section,level where each source file +# is assigned a unique section. Lower levels result in less +# output, Full debugging (level 9) can result in a very large +# log file, so be careful. +# +# The magic word "ALL" sets debugging levels for all sections. +# The default is to run with "ALL,1" to record important warnings. +# +# The rotate=N option can be used to keep more or less of these logs +# than would otherwise be kept by logfile_rotate. +# For most uses a single log should be enough to monitor current +# events affecting Squid. +#Default: +# Log all critical and important messages. + +# TAG: coredump_dir +# By default Squid leaves core files in the directory from where +# it was started. If you set 'coredump_dir' to a directory +# that exists, Squid will chdir() to that directory at startup +# and coredump files will be left there. +# +#Default: +# Use the directory from where Squid was started. +# + +# Leave coredumps in the first cache dir +coredump_dir /var/spool/squid + +# OPTIONS FOR FTP GATEWAYING +# ----------------------------------------------------------------------------- + +# TAG: ftp_user +# If you want the anonymous login password to be more informative +# (and enable the use of picky FTP servers), set this to something +# reasonable for your domain, like wwwuser@somewhere.net +# +# The reason why this is domainless by default is the +# request can be made on the behalf of a user in any domain, +# depending on how the cache is used. +# Some FTP server also validate the email address is valid +# (for example perl.com). +#Default: +# ftp_user Squid@ + +# TAG: ftp_passive +# If your firewall does not allow Squid to use passive +# connections, turn off this option. +# +# Use of ftp_epsv_all option requires this to be ON. +#Default: +# ftp_passive on + +# TAG: ftp_epsv_all +# FTP Protocol extensions permit the use of a special "EPSV ALL" command. +# +# NATs may be able to put the connection on a "fast path" through the +# translator, as the EPRT command will never be used and therefore, +# translation of the data portion of the segments will never be needed. +# +# When a client only expects to do two-way FTP transfers this may be +# useful. +# If squid finds that it must do a three-way FTP transfer after issuing +# an EPSV ALL command, the FTP session will fail. +# +# If you have any doubts about this option do not use it. +# Squid will nicely attempt all other connection methods. +# +# Requires ftp_passive to be ON (default) for any effect. +#Default: +# ftp_epsv_all off + +# TAG: ftp_epsv +# FTP Protocol extensions permit the use of a special "EPSV" command. +# +# NATs may be able to put the connection on a "fast path" through the +# translator using EPSV, as the EPRT command will never be used +# and therefore, translation of the data portion of the segments +# will never be needed. +# +# EPSV is often required to interoperate with FTP servers on IPv6 +# networks. On the other hand, it may break some IPv4 servers. +# +# By default, EPSV may try EPSV with any FTP server. To fine tune +# that decision, you may restrict EPSV to certain clients or servers +# using ACLs: +# +# ftp_epsv allow|deny al1 acl2 ... +# +# WARNING: Disabling EPSV may cause problems with external NAT and IPv6. +# +# Only fast ACLs are supported. +# Requires ftp_passive to be ON (default) for any effect. +#Default: +# none + +# TAG: ftp_eprt +# FTP Protocol extensions permit the use of a special "EPRT" command. +# +# This extension provides a protocol neutral alternative to the +# IPv4-only PORT command. When supported it enables active FTP data +# channels over IPv6 and efficient NAT handling. +# +# Turning this OFF will prevent EPRT being attempted and will skip +# straight to using PORT for IPv4 servers. +# +# Some devices are known to not handle this extension correctly and +# may result in crashes. Devices which suport EPRT enough to fail +# cleanly will result in Squid attempting PORT anyway. This directive +# should only be disabled when EPRT results in device failures. +# +# WARNING: Doing so will convert Squid back to the old behavior with all +# the related problems with external NAT devices/layers and IPv4-only FTP. +#Default: +# ftp_eprt on + +# TAG: ftp_sanitycheck +# For security and data integrity reasons Squid by default performs +# sanity checks of the addresses of FTP data connections ensure the +# data connection is to the requested server. If you need to allow +# FTP connections to servers using another IP address for the data +# connection turn this off. +#Default: +# ftp_sanitycheck on + +# TAG: ftp_telnet_protocol +# The FTP protocol is officially defined to use the telnet protocol +# as transport channel for the control connection. However, many +# implementations are broken and does not respect this aspect of +# the FTP protocol. +# +# If you have trouble accessing files with ASCII code 255 in the +# path or similar problems involving this ASCII code you can +# try setting this directive to off. If that helps, report to the +# operator of the FTP server in question that their FTP server +# is broken and does not follow the FTP standard. +#Default: +# ftp_telnet_protocol on + +# OPTIONS FOR EXTERNAL SUPPORT PROGRAMS +# ----------------------------------------------------------------------------- + +# TAG: diskd_program +# Specify the location of the diskd executable. +# Note this is only useful if you have compiled in +# diskd as one of the store io modules. +#Default: +# diskd_program /usr/lib/squid/diskd + +# TAG: unlinkd_program +# Specify the location of the executable for file deletion process. +#Default: +# unlinkd_program /usr/lib/squid/unlinkd + +# TAG: pinger_program +# Specify the location of the executable for the pinger process. +#Default: +# pinger_program /usr/lib/squid/pinger + +# TAG: pinger_enable +# Control whether the pinger is active at run-time. +# Enables turning ICMP pinger on and off with a simple +# squid -k reconfigure. +#Default: +# pinger_enable on + +# OPTIONS FOR URL REWRITING +# ----------------------------------------------------------------------------- + +# TAG: url_rewrite_program +# Specify the location of the executable URL rewriter to use. +# Since they can perform almost any function there isn't one included. +# +# For each requested URL, the rewriter will receive on line with the format +# +# [channel-ID <SP>] URL [<SP> extras]<NL> +# +# See url_rewrite_extras on how to send "extras" with optional values to +# the helper. +# After processing the request the helper must reply using the following format: +# +# [channel-ID <SP>] result [<SP> kv-pairs] +# +# The result code can be: +# +# OK status=30N url="..." +# Redirect the URL to the one supplied in 'url='. +# 'status=' is optional and contains the status code to send +# the client in Squids HTTP response. It must be one of the +# HTTP redirect status codes: 301, 302, 303, 307, 308. +# When no status is given Squid will use 302. +# +# OK rewrite-url="..." +# Rewrite the URL to the one supplied in 'rewrite-url='. +# The new URL is fetched directly by Squid and returned to +# the client as the response to its request. +# +# OK +# When neither of url= and rewrite-url= are sent Squid does +# not change the URL. +# +# ERR +# Do not change the URL. +# +# BH +# An internal error occurred in the helper, preventing +# a result being identified. The 'message=' key name is +# reserved for delivering a log message. +# +# +# In addition to the above kv-pairs Squid also understands the following +# optional kv-pairs received from URL rewriters: +# clt_conn_tag=TAG +# Associates a TAG with the client TCP connection. +# The TAG is treated as a regular annotation but persists across +# future requests on the client connection rather than just the +# current request. A helper may update the TAG during subsequent +# requests be returning a new kv-pair. +# +# When using the concurrency= option the protocol is changed by +# introducing a query channel tag in front of the request/response. +# The query channel tag is a number between 0 and concurrency-1. +# This value must be echoed back unchanged to Squid as the first part +# of the response relating to its request. +# +# WARNING: URL re-writing ability should be avoided whenever possible. +# Use the URL redirect form of response instead. +# +# Re-write creates a difference in the state held by the client +# and server. Possibly causing confusion when the server response +# contains snippets of its view state. Embeded URLs, response +# and content Location headers, etc. are not re-written by this +# interface. +# +# By default, a URL rewriter is not used. +#Default: +# none + +# TAG: url_rewrite_children +# The maximum number of redirector processes to spawn. If you limit +# it too few Squid will have to wait for them to process a backlog of +# URLs, slowing it down. If you allow too many they will use RAM +# and other system resources noticably. +# +# The startup= and idle= options allow some measure of skew in your +# tuning. +# +# startup= +# +# Sets a minimum of how many processes are to be spawned when Squid +# starts or reconfigures. When set to zero the first request will +# cause spawning of the first child process to handle it. +# +# Starting too few will cause an initial slowdown in traffic as Squid +# attempts to simultaneously spawn enough processes to cope. +# +# idle= +# +# Sets a minimum of how many processes Squid is to try and keep available +# at all times. When traffic begins to rise above what the existing +# processes can handle this many more will be spawned up to the maximum +# configured. A minimum setting of 1 is required. +# +# concurrency= +# +# The number of requests each redirector helper can handle in +# parallel. Defaults to 0 which indicates the redirector +# is a old-style single threaded redirector. +# +# When this directive is set to a value >= 1 then the protocol +# used to communicate with the helper is modified to include +# an ID in front of the request/response. The ID from the request +# must be echoed back with the response to that request. +#Default: +# url_rewrite_children 20 startup=0 idle=1 concurrency=0 + +# TAG: url_rewrite_host_header +# To preserve same-origin security policies in browsers and +# prevent Host: header forgery by redirectors Squid rewrites +# any Host: header in redirected requests. +# +# If you are running an accelerator this may not be a wanted +# effect of a redirector. This directive enables you disable +# Host: alteration in reverse-proxy traffic. +# +# WARNING: Entries are cached on the result of the URL rewriting +# process, so be careful if you have domain-virtual hosts. +# +# WARNING: Squid and other software verifies the URL and Host +# are matching, so be careful not to relay through other proxies +# or inspecting firewalls with this disabled. +#Default: +# url_rewrite_host_header on + +# TAG: url_rewrite_access +# If defined, this access list specifies which requests are +# sent to the redirector processes. +# +# This clause supports both fast and slow acl types. +# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details. +#Default: +# Allow, unless rules exist in squid.conf. + +# TAG: url_rewrite_bypass +# When this is 'on', a request will not go through the +# redirector if all the helpers are busy. If this is 'off' +# and the redirector queue grows too large, Squid will exit +# with a FATAL error and ask you to increase the number of +# redirectors. You should only enable this if the redirectors +# are not critical to your caching system. If you use +# redirectors for access control, and you enable this option, +# users may have access to pages they should not +# be allowed to request. +#Default: +# url_rewrite_bypass off + +# TAG: url_rewrite_extras +# Specifies a string to be append to request line format for the +# rewriter helper. "Quoted" format values may contain spaces and +# logformat %macros. In theory, any logformat %macro can be used. +# In practice, a %macro expands as a dash (-) if the helper request is +# sent before the required macro information is available to Squid. +#Default: +# url_rewrite_extras "%>a/%>A %un %>rm myip=%la myport=%lp" + +# OPTIONS FOR STORE ID +# ----------------------------------------------------------------------------- + +# TAG: store_id_program +# Specify the location of the executable StoreID helper to use. +# Since they can perform almost any function there isn't one included. +# +# For each requested URL, the helper will receive one line with the format +# +# [channel-ID <SP>] URL [<SP> extras]<NL> +# +# +# After processing the request the helper must reply using the following format: +# +# [channel-ID <SP>] result [<SP> kv-pairs] +# +# The result code can be: +# +# OK store-id="..." +# Use the StoreID supplied in 'store-id='. +# +# ERR +# The default is to use HTTP request URL as the store ID. +# +# BH +# An internal error occured in the helper, preventing +# a result being identified. +# +# In addition to the above kv-pairs Squid also understands the following +# optional kv-pairs received from URL rewriters: +# clt_conn_tag=TAG +# Associates a TAG with the client TCP connection. +# Please see url_rewrite_program related documentation for this +# kv-pair +# +# Helper programs should be prepared to receive and possibly ignore +# additional whitespace-separated tokens on each input line. +# +# When using the concurrency= option the protocol is changed by +# introducing a query channel tag in front of the request/response. +# The query channel tag is a number between 0 and concurrency-1. +# This value must be echoed back unchanged to Squid as the first part +# of the response relating to its request. +# +# NOTE: when using StoreID refresh_pattern will apply to the StoreID +# returned from the helper and not the URL. +# +# WARNING: Wrong StoreID value returned by a careless helper may result +# in the wrong cached response returned to the user. +# +# By default, a StoreID helper is not used. +#Default: +# none + +# TAG: store_id_extras +# Specifies a string to be append to request line format for the +# StoreId helper. "Quoted" format values may contain spaces and +# logformat %macros. In theory, any logformat %macro can be used. +# In practice, a %macro expands as a dash (-) if the helper request is +# sent before the required macro information is available to Squid. +#Default: +# store_id_extras "%>a/%>A %un %>rm myip=%la myport=%lp" + +# TAG: store_id_children +# The maximum number of StoreID helper processes to spawn. If you limit +# it too few Squid will have to wait for them to process a backlog of +# requests, slowing it down. If you allow too many they will use RAM +# and other system resources noticably. +# +# The startup= and idle= options allow some measure of skew in your +# tuning. +# +# startup= +# +# Sets a minimum of how many processes are to be spawned when Squid +# starts or reconfigures. When set to zero the first request will +# cause spawning of the first child process to handle it. +# +# Starting too few will cause an initial slowdown in traffic as Squid +# attempts to simultaneously spawn enough processes to cope. +# +# idle= +# +# Sets a minimum of how many processes Squid is to try and keep available +# at all times. When traffic begins to rise above what the existing +# processes can handle this many more will be spawned up to the maximum +# configured. A minimum setting of 1 is required. +# +# concurrency= +# +# The number of requests each storeID helper can handle in +# parallel. Defaults to 0 which indicates the helper +# is a old-style single threaded program. +# +# When this directive is set to a value >= 1 then the protocol +# used to communicate with the helper is modified to include +# an ID in front of the request/response. The ID from the request +# must be echoed back with the response to that request. +#Default: +# store_id_children 20 startup=0 idle=1 concurrency=0 + +# TAG: store_id_access +# If defined, this access list specifies which requests are +# sent to the StoreID processes. By default all requests +# are sent. +# +# This clause supports both fast and slow acl types. +# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details. +#Default: +# Allow, unless rules exist in squid.conf. + +# TAG: store_id_bypass +# When this is 'on', a request will not go through the +# helper if all helpers are busy. If this is 'off' +# and the helper queue grows too large, Squid will exit +# with a FATAL error and ask you to increase the number of +# helpers. You should only enable this if the helperss +# are not critical to your caching system. If you use +# helpers for critical caching components, and you enable this +# option, users may not get objects from cache. +#Default: +# store_id_bypass on + +# OPTIONS FOR TUNING THE CACHE +# ----------------------------------------------------------------------------- + +# TAG: cache +# Requests denied by this directive will not be served from the cache +# and their responses will not be stored in the cache. This directive +# has no effect on other transactions and on already cached responses. +# +# This clause supports both fast and slow acl types. +# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details. +# +# This and the two other similar caching directives listed below are +# checked at different transaction processing stages, have different +# access to response information, affect different cache operations, +# and differ in slow ACLs support: +# +# * cache: Checked before Squid makes a hit/miss determination. +# No access to reply information! +# Denies both serving a hit and storing a miss. +# Supports both fast and slow ACLs. +# * send_hit: Checked after a hit was detected. +# Has access to reply (hit) information. +# Denies serving a hit only. +# Supports fast ACLs only. +# * store_miss: Checked before storing a cachable miss. +# Has access to reply (miss) information. +# Denies storing a miss only. +# Supports fast ACLs only. +# +# If you are not sure which of the three directives to use, apply the +# following decision logic: +# +# * If your ACL(s) are of slow type _and_ need response info, redesign. +# Squid does not support that particular combination at this time. +# Otherwise: +# * If your directive ACL(s) are of slow type, use "cache"; and/or +# * if your directive ACL(s) need no response info, use "cache". +# Otherwise: +# * If you do not want the response cached, use store_miss; and/or +# * if you do not want a hit on a cached response, use send_hit. +#Default: +# By default, this directive is unused and has no effect. + +# TAG: send_hit +# Responses denied by this directive will not be served from the cache +# (but may still be cached, see store_miss). This directive has no +# effect on the responses it allows and on the cached objects. +# +# Please see the "cache" directive for a summary of differences among +# store_miss, send_hit, and cache directives. +# +# Unlike the "cache" directive, send_hit only supports fast acl +# types. See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details. +# +# For example: +# +# # apply custom Store ID mapping to some URLs +# acl MapMe dstdomain .c.example.com +# store_id_program ... +# store_id_access allow MapMe +# +# # but prevent caching of special responses +# # such as 302 redirects that cause StoreID loops +# acl Ordinary http_status 200-299 +# store_miss deny MapMe !Ordinary +# +# # and do not serve any previously stored special responses +# # from the cache (in case they were already cached before +# # the above store_miss rule was in effect). +# send_hit deny MapMe !Ordinary +#Default: +# By default, this directive is unused and has no effect. + +# TAG: store_miss +# Responses denied by this directive will not be cached (but may still +# be served from the cache, see send_hit). This directive has no +# effect on the responses it allows and on the already cached responses. +# +# Please see the "cache" directive for a summary of differences among +# store_miss, send_hit, and cache directives. See the +# send_hit directive for a usage example. +# +# Unlike the "cache" directive, store_miss only supports fast acl +# types. See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details. +#Default: +# By default, this directive is unused and has no effect. + +# TAG: max_stale time-units +# This option puts an upper limit on how stale content Squid +# will serve from the cache if cache validation fails. +# Can be overriden by the refresh_pattern max-stale option. +#Default: +# max_stale 1 week + +# TAG: refresh_pattern +# usage: refresh_pattern [-i] regex min percent max [options] +# +# By default, regular expressions are CASE-SENSITIVE. To make +# them case-insensitive, use the -i option. +# +# 'Min' is the time (in minutes) an object without an explicit +# expiry time should be considered fresh. The recommended +# value is 0, any higher values may cause dynamic applications +# to be erroneously cached unless the application designer +# has taken the appropriate actions. +# +# 'Percent' is a percentage of the objects age (time since last +# modification age) an object without explicit expiry time +# will be considered fresh. +# +# 'Max' is an upper limit on how long objects without an explicit +# expiry time will be considered fresh. +# +# options: override-expire +# override-lastmod +# reload-into-ims +# ignore-reload +# ignore-no-store +# ignore-must-revalidate +# ignore-private +# ignore-auth +# max-stale=NN +# refresh-ims +# store-stale +# +# override-expire enforces min age even if the server +# sent an explicit expiry time (e.g., with the +# Expires: header or Cache-Control: max-age). Doing this +# VIOLATES the HTTP standard. Enabling this feature +# could make you liable for problems which it causes. +# +# Note: override-expire does not enforce staleness - it only extends +# freshness / min. If the server returns a Expires time which +# is longer than your max time, Squid will still consider +# the object fresh for that period of time. +# +# override-lastmod enforces min age even on objects +# that were modified recently. +# +# reload-into-ims changes a client no-cache or ``reload'' +# request for a cached entry into a conditional request using +# If-Modified-Since and/or If-None-Match headers, provided the +# cached entry has a Last-Modified and/or a strong ETag header. +# Doing this VIOLATES the HTTP standard. Enabling this feature +# could make you liable for problems which it causes. +# +# ignore-reload ignores a client no-cache or ``reload'' +# header. Doing this VIOLATES the HTTP standard. Enabling +# this feature could make you liable for problems which +# it causes. +# +# ignore-no-store ignores any ``Cache-control: no-store'' +# headers received from a server. Doing this VIOLATES +# the HTTP standard. Enabling this feature could make you +# liable for problems which it causes. +# +# ignore-must-revalidate ignores any ``Cache-Control: must-revalidate`` +# headers received from a server. Doing this VIOLATES +# the HTTP standard. Enabling this feature could make you +# liable for problems which it causes. +# +# ignore-private ignores any ``Cache-control: private'' +# headers received from a server. Doing this VIOLATES +# the HTTP standard. Enabling this feature could make you +# liable for problems which it causes. +# +# ignore-auth caches responses to requests with authorization, +# as if the originserver had sent ``Cache-control: public'' +# in the response header. Doing this VIOLATES the HTTP standard. +# Enabling this feature could make you liable for problems which +# it causes. +# +# refresh-ims causes squid to contact the origin server +# when a client issues an If-Modified-Since request. This +# ensures that the client will receive an updated version +# if one is available. +# +# store-stale stores responses even if they don't have explicit +# freshness or a validator (i.e., Last-Modified or an ETag) +# present, or if they're already stale. By default, Squid will +# not cache such responses because they usually can't be +# reused. Note that such responses will be stale by default. +# +# max-stale=NN provide a maximum staleness factor. Squid won't +# serve objects more stale than this even if it failed to +# validate the object. Default: use the max_stale global limit. +# +# Basically a cached object is: +# +# FRESH if expire > now, else STALE +# STALE if age > max +# FRESH if lm-factor < percent, else STALE +# FRESH if age < min +# else STALE +# +# The refresh_pattern lines are checked in the order listed here. +# The first entry which matches is used. If none of the entries +# match the default will be used. +# +# Note, you must uncomment all the default lines if you want +# to change one. The default setting is only active if none is +# used. +# +# + +# +# Add any of your own refresh_pattern entries above these. +# +refresh_pattern ^ftp: 1440 20% 10080 +refresh_pattern ^gopher: 1440 0% 1440 +refresh_pattern -i (/cgi-bin/|\?) 0 0% 0 +refresh_pattern -i (zImage|\.dtb|\.tar|\.gz|\.xz) 129600 100% 129600 +refresh_pattern . 0 20% 4320 + +# TAG: quick_abort_min (KB) +#Default: +# quick_abort_min 16 KB + +# TAG: quick_abort_max (KB) +#Default: +# quick_abort_max 16 KB + +# TAG: quick_abort_pct (percent) +# The cache by default continues downloading aborted requests +# which are almost completed (less than 16 KB remaining). This +# may be undesirable on slow (e.g. SLIP) links and/or very busy +# caches. Impatient users may tie up file descriptors and +# bandwidth by repeatedly requesting and immediately aborting +# downloads. +# +# When the user aborts a request, Squid will check the +# quick_abort values to the amount of data transferred until +# then. +# +# If the transfer has less than 'quick_abort_min' KB remaining, +# it will finish the retrieval. +# +# If the transfer has more than 'quick_abort_max' KB remaining, +# it will abort the retrieval. +# +# If more than 'quick_abort_pct' of the transfer has completed, +# it will finish the retrieval. +# +# If you do not want any retrieval to continue after the client +# has aborted, set both 'quick_abort_min' and 'quick_abort_max' +# to '0 KB'. +# +# If you want retrievals to always continue if they are being +# cached set 'quick_abort_min' to '-1 KB'. +#Default: +# quick_abort_pct 95 + +# TAG: read_ahead_gap buffer-size +# The amount of data the cache will buffer ahead of what has been +# sent to the client when retrieving an object from another server. +#Default: +# read_ahead_gap 16 KB + +# TAG: negative_ttl time-units +# Set the Default Time-to-Live (TTL) for failed requests. +# Certain types of failures (such as "connection refused" and +# "404 Not Found") are able to be negatively-cached for a short time. +# Modern web servers should provide Expires: header, however if they +# do not this can provide a minimum TTL. +# The default is not to cache errors with unknown expiry details. +# +# Note that this is different from negative caching of DNS lookups. +# +# WARNING: Doing this VIOLATES the HTTP standard. Enabling +# this feature could make you liable for problems which it +# causes. +#Default: +# negative_ttl 0 seconds + +# TAG: positive_dns_ttl time-units +# Upper limit on how long Squid will cache positive DNS responses. +# Default is 6 hours (360 minutes). This directive must be set +# larger than negative_dns_ttl. +#Default: +# positive_dns_ttl 6 hours + +# TAG: negative_dns_ttl time-units +# Time-to-Live (TTL) for negative caching of failed DNS lookups. +# This also sets the lower cache limit on positive lookups. +# Minimum value is 1 second, and it is not recommendable to go +# much below 10 seconds. +#Default: +# negative_dns_ttl 1 minutes + +# TAG: range_offset_limit size [acl acl...] +# usage: (size) [units] [[!]aclname] +# +# Sets an upper limit on how far (number of bytes) into the file +# a Range request may be to cause Squid to prefetch the whole file. +# If beyond this limit, Squid forwards the Range request as it is and +# the result is NOT cached. +# +# This is to stop a far ahead range request (lets say start at 17MB) +# from making Squid fetch the whole object up to that point before +# sending anything to the client. +# +# Multiple range_offset_limit lines may be specified, and they will +# be searched from top to bottom on each request until a match is found. +# The first match found will be used. If no line matches a request, the +# default limit of 0 bytes will be used. +# +# 'size' is the limit specified as a number of units. +# +# 'units' specifies whether to use bytes, KB, MB, etc. +# If no units are specified bytes are assumed. +# +# A size of 0 causes Squid to never fetch more than the +# client requested. (default) +# +# A size of 'none' causes Squid to always fetch the object from the +# beginning so it may cache the result. (2.0 style) +# +# 'aclname' is the name of a defined ACL. +# +# NP: Using 'none' as the byte value here will override any quick_abort settings +# that may otherwise apply to the range request. The range request will +# be fully fetched from start to finish regardless of the client +# actions. This affects bandwidth usage. +#Default: +# none + +# TAG: minimum_expiry_time (seconds) +# The minimum caching time according to (Expires - Date) +# headers Squid honors if the object can't be revalidated. +# The default is 60 seconds. +# +# In reverse proxy environments it might be desirable to honor +# shorter object lifetimes. It is most likely better to make +# your server return a meaningful Last-Modified header however. +# +# In ESI environments where page fragments often have short +# lifetimes, this will often be best set to 0. +#Default: +# minimum_expiry_time 60 seconds + +# TAG: store_avg_object_size (bytes) +# Average object size, used to estimate number of objects your +# cache can hold. The default is 13 KB. +# +# This is used to pre-seed the cache index memory allocation to +# reduce expensive reallocate operations while handling clients +# traffic. Too-large values may result in memory allocation during +# peak traffic, too-small values will result in wasted memory. +# +# Check the cache manager 'info' report metrics for the real +# object sizes seen by your Squid before tuning this. +#Default: +# store_avg_object_size 13 KB + +# TAG: store_objects_per_bucket +# Target number of objects per bucket in the store hash table. +# Lowering this value increases the total number of buckets and +# also the storage maintenance rate. The default is 20. +#Default: +# store_objects_per_bucket 20 + +# HTTP OPTIONS +# ----------------------------------------------------------------------------- + +# TAG: request_header_max_size (KB) +# This specifies the maximum size for HTTP headers in a request. +# Request headers are usually relatively small (about 512 bytes). +# Placing a limit on the request header size will catch certain +# bugs (for example with persistent connections) and possibly +# buffer-overflow or denial-of-service attacks. +#Default: +# request_header_max_size 64 KB + +# TAG: reply_header_max_size (KB) +# This specifies the maximum size for HTTP headers in a reply. +# Reply headers are usually relatively small (about 512 bytes). +# Placing a limit on the reply header size will catch certain +# bugs (for example with persistent connections) and possibly +# buffer-overflow or denial-of-service attacks. +#Default: +# reply_header_max_size 64 KB + +# TAG: request_body_max_size (bytes) +# This specifies the maximum size for an HTTP request body. +# In other words, the maximum size of a PUT/POST request. +# A user who attempts to send a request with a body larger +# than this limit receives an "Invalid Request" error message. +# If you set this parameter to a zero (the default), there will +# be no limit imposed. +# +# See also client_request_buffer_max_size for an alternative +# limitation on client uploads which can be configured. +#Default: +# No limit. + +# TAG: client_request_buffer_max_size (bytes) +# This specifies the maximum buffer size of a client request. +# It prevents squid eating too much memory when somebody uploads +# a large file. +#Default: +# client_request_buffer_max_size 512 KB + +# TAG: broken_posts +# A list of ACL elements which, if matched, causes Squid to send +# an extra CRLF pair after the body of a PUT/POST request. +# +# Some HTTP servers has broken implementations of PUT/POST, +# and rely on an extra CRLF pair sent by some WWW clients. +# +# Quote from RFC2616 section 4.1 on this matter: +# +# Note: certain buggy HTTP/1.0 client implementations generate an +# extra CRLF's after a POST request. To restate what is explicitly +# forbidden by the BNF, an HTTP/1.1 client must not preface or follow +# a request with an extra CRLF. +# +# This clause only supports fast acl types. +# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details. +# +#Example: +# acl buggy_server url_regex ^http://.... +# broken_posts allow buggy_server +#Default: +# Obey RFC 2616. + +# TAG: adaptation_uses_indirect_client on|off +# Controls whether the indirect client IP address (instead of the direct +# client IP address) is passed to adaptation services. +# +# See also: follow_x_forwarded_for adaptation_send_client_ip +#Default: +# adaptation_uses_indirect_client on + +# TAG: via on|off +# If set (default), Squid will include a Via header in requests and +# replies as required by RFC2616. +#Default: +# via on + +# TAG: ie_refresh on|off +# Microsoft Internet Explorer up until version 5.5 Service +# Pack 1 has an issue with transparent proxies, wherein it +# is impossible to force a refresh. Turning this on provides +# a partial fix to the problem, by causing all IMS-REFRESH +# requests from older IE versions to check the origin server +# for fresh content. This reduces hit ratio by some amount +# (~10% in my experience), but allows users to actually get +# fresh content when they want it. Note because Squid +# cannot tell if the user is using 5.5 or 5.5SP1, the behavior +# of 5.5 is unchanged from old versions of Squid (i.e. a +# forced refresh is impossible). Newer versions of IE will, +# hopefully, continue to have the new behavior and will be +# handled based on that assumption. This option defaults to +# the old Squid behavior, which is better for hit ratios but +# worse for clients using IE, if they need to be able to +# force fresh content. +#Default: +# ie_refresh off + +# TAG: vary_ignore_expire on|off +# Many HTTP servers supporting Vary gives such objects +# immediate expiry time with no cache-control header +# when requested by a HTTP/1.0 client. This option +# enables Squid to ignore such expiry times until +# HTTP/1.1 is fully implemented. +# +# WARNING: If turned on this may eventually cause some +# varying objects not intended for caching to get cached. +#Default: +# vary_ignore_expire off + +# TAG: request_entities +# Squid defaults to deny GET and HEAD requests with request entities, +# as the meaning of such requests are undefined in the HTTP standard +# even if not explicitly forbidden. +# +# Set this directive to on if you have clients which insists +# on sending request entities in GET or HEAD requests. But be warned +# that there is server software (both proxies and web servers) which +# can fail to properly process this kind of request which may make you +# vulnerable to cache pollution attacks if enabled. +#Default: +# request_entities off + +# TAG: request_header_access +# Usage: request_header_access header_name allow|deny [!]aclname ... +# +# WARNING: Doing this VIOLATES the HTTP standard. Enabling +# this feature could make you liable for problems which it +# causes. +# +# This option replaces the old 'anonymize_headers' and the +# older 'http_anonymizer' option with something that is much +# more configurable. A list of ACLs for each header name allows +# removal of specific header fields under specific conditions. +# +# This option only applies to outgoing HTTP request headers (i.e., +# headers sent by Squid to the next HTTP hop such as a cache peer +# or an origin server). The option has no effect during cache hit +# detection. The equivalent adaptation vectoring point in ICAP +# terminology is post-cache REQMOD. +# +# The option is applied to individual outgoing request header +# fields. For each request header field F, Squid uses the first +# qualifying sets of request_header_access rules: +# +# 1. Rules with header_name equal to F's name. +# 2. Rules with header_name 'Other', provided F's name is not +# on the hard-coded list of commonly used HTTP header names. +# 3. Rules with header_name 'All'. +# +# Within that qualifying rule set, rule ACLs are checked as usual. +# If ACLs of an "allow" rule match, the header field is allowed to +# go through as is. If ACLs of a "deny" rule match, the header is +# removed and request_header_replace is then checked to identify +# if the removed header has a replacement. If no rules within the +# set have matching ACLs, the header field is left as is. +# +# For example, to achieve the same behavior as the old +# 'http_anonymizer standard' option, you should use: +# +# request_header_access From deny all +# request_header_access Referer deny all +# request_header_access User-Agent deny all +# +# Or, to reproduce the old 'http_anonymizer paranoid' feature +# you should use: +# +# request_header_access Authorization allow all +# request_header_access Proxy-Authorization allow all +# request_header_access Cache-Control allow all +# request_header_access Content-Length allow all +# request_header_access Content-Type allow all +# request_header_access Date allow all +# request_header_access Host allow all +# request_header_access If-Modified-Since allow all +# request_header_access Pragma allow all +# request_header_access Accept allow all +# request_header_access Accept-Charset allow all +# request_header_access Accept-Encoding allow all +# request_header_access Accept-Language allow all +# request_header_access Connection allow all +# request_header_access All deny all +# +# HTTP reply headers are controlled with the reply_header_access directive. +# +# By default, all headers are allowed (no anonymizing is performed). +#Default: +# No limits. + +# TAG: reply_header_access +# Usage: reply_header_access header_name allow|deny [!]aclname ... +# +# WARNING: Doing this VIOLATES the HTTP standard. Enabling +# this feature could make you liable for problems which it +# causes. +# +# This option only applies to reply headers, i.e., from the +# server to the client. +# +# This is the same as request_header_access, but in the other +# direction. Please see request_header_access for detailed +# documentation. +# +# For example, to achieve the same behavior as the old +# 'http_anonymizer standard' option, you should use: +# +# reply_header_access Server deny all +# reply_header_access WWW-Authenticate deny all +# reply_header_access Link deny all +# +# Or, to reproduce the old 'http_anonymizer paranoid' feature +# you should use: +# +# reply_header_access Allow allow all +# reply_header_access WWW-Authenticate allow all +# reply_header_access Proxy-Authenticate allow all +# reply_header_access Cache-Control allow all +# reply_header_access Content-Encoding allow all +# reply_header_access Content-Length allow all +# reply_header_access Content-Type allow all +# reply_header_access Date allow all +# reply_header_access Expires allow all +# reply_header_access Last-Modified allow all +# reply_header_access Location allow all +# reply_header_access Pragma allow all +# reply_header_access Content-Language allow all +# reply_header_access Retry-After allow all +# reply_header_access Title allow all +# reply_header_access Content-Disposition allow all +# reply_header_access Connection allow all +# reply_header_access All deny all +# +# HTTP request headers are controlled with the request_header_access directive. +# +# By default, all headers are allowed (no anonymizing is +# performed). +#Default: +# No limits. + +# TAG: request_header_replace +# Usage: request_header_replace header_name message +# Example: request_header_replace User-Agent Nutscrape/1.0 (CP/M; 8-bit) +# +# This option allows you to change the contents of headers +# denied with request_header_access above, by replacing them +# with some fixed string. +# +# This only applies to request headers, not reply headers. +# +# By default, headers are removed if denied. +#Default: +# none + +# TAG: reply_header_replace +# Usage: reply_header_replace header_name message +# Example: reply_header_replace Server Foo/1.0 +# +# This option allows you to change the contents of headers +# denied with reply_header_access above, by replacing them +# with some fixed string. +# +# This only applies to reply headers, not request headers. +# +# By default, headers are removed if denied. +#Default: +# none + +# TAG: request_header_add +# Usage: request_header_add field-name field-value acl1 [acl2] ... +# Example: request_header_add X-Client-CA "CA=%ssl::>cert_issuer" all +# +# This option adds header fields to outgoing HTTP requests (i.e., +# request headers sent by Squid to the next HTTP hop such as a +# cache peer or an origin server). The option has no effect during +# cache hit detection. The equivalent adaptation vectoring point +# in ICAP terminology is post-cache REQMOD. +# +# Field-name is a token specifying an HTTP header name. If a +# standard HTTP header name is used, Squid does not check whether +# the new header conflicts with any existing headers or violates +# HTTP rules. If the request to be modified already contains a +# field with the same name, the old field is preserved but the +# header field values are not merged. +# +# Field-value is either a token or a quoted string. If quoted +# string format is used, then the surrounding quotes are removed +# while escape sequences and %macros are processed. +# +# In theory, all of the logformat codes can be used as %macros. +# However, unlike logging (which happens at the very end of +# transaction lifetime), the transaction may not yet have enough +# information to expand a macro when the new header value is needed. +# And some information may already be available to Squid but not yet +# committed where the macro expansion code can access it (report +# such instances!). The macro will be expanded into a single dash +# ('-') in such cases. Not all macros have been tested. +# +# One or more Squid ACLs may be specified to restrict header +# injection to matching requests. As always in squid.conf, all +# ACLs in an option ACL list must be satisfied for the insertion +# to happen. The request_header_add option supports fast ACLs +# only. +#Default: +# none + +# TAG: note +# This option used to log custom information about the master +# transaction. For example, an admin may configure Squid to log +# which "user group" the transaction belongs to, where "user group" +# will be determined based on a set of ACLs and not [just] +# authentication information. +# Values of key/value pairs can be logged using %{key}note macros: +# +# note key value acl ... +# logformat myFormat ... %{key}note ... +#Default: +# none + +# TAG: relaxed_header_parser on|off|warn +# In the default "on" setting Squid accepts certain forms +# of non-compliant HTTP messages where it is unambiguous +# what the sending application intended even if the message +# is not correctly formatted. The messages is then normalized +# to the correct form when forwarded by Squid. +# +# If set to "warn" then a warning will be emitted in cache.log +# each time such HTTP error is encountered. +# +# If set to "off" then such HTTP errors will cause the request +# or response to be rejected. +#Default: +# relaxed_header_parser on + +# TAG: collapsed_forwarding (on|off) +# When enabled, instead of forwarding each concurrent request for +# the same URL, Squid just sends the first of them. The other, so +# called "collapsed" requests, wait for the response to the first +# request and, if it happens to be cachable, use that response. +# Here, "concurrent requests" means "received after the first +# request headers were parsed and before the corresponding response +# headers were parsed". +# +# This feature is disabled by default: enabling collapsed +# forwarding needlessly delays forwarding requests that look +# cachable (when they are collapsed) but then need to be forwarded +# individually anyway because they end up being for uncachable +# content. However, in some cases, such as acceleration of highly +# cachable content with periodic or grouped expiration times, the +# gains from collapsing [large volumes of simultaneous refresh +# requests] outweigh losses from such delays. +# +# Squid collapses two kinds of requests: regular client requests +# received on one of the listening ports and internal "cache +# revalidation" requests which are triggered by those regular +# requests hitting a stale cached object. Revalidation collapsing +# is currently disabled for Squid instances containing SMP-aware +# disk or memory caches and for Vary-controlled cached objects. +#Default: +# collapsed_forwarding off + +# TIMEOUTS +# ----------------------------------------------------------------------------- + +# TAG: forward_timeout time-units +# This parameter specifies how long Squid should at most attempt in +# finding a forwarding path for the request before giving up. +#Default: +# forward_timeout 4 minutes + +# TAG: connect_timeout time-units +# This parameter specifies how long to wait for the TCP connect to +# the requested server or peer to complete before Squid should +# attempt to find another path where to forward the request. +#Default: +# connect_timeout 1 minute + +# TAG: peer_connect_timeout time-units +# This parameter specifies how long to wait for a pending TCP +# connection to a peer cache. The default is 30 seconds. You +# may also set different timeout values for individual neighbors +# with the 'connect-timeout' option on a 'cache_peer' line. +#Default: +# peer_connect_timeout 30 seconds + +# TAG: read_timeout time-units +# Applied on peer server connections. +# +# After each successful read(), the timeout will be extended by this +# amount. If no data is read again after this amount of time, +# the request is aborted and logged with ERR_READ_TIMEOUT. +# +# The default is 15 minutes. +#Default: +# read_timeout 15 minutes + +# TAG: write_timeout time-units +# This timeout is tracked for all connections that have data +# available for writing and are waiting for the socket to become +# ready. After each successful write, the timeout is extended by +# the configured amount. If Squid has data to write but the +# connection is not ready for the configured duration, the +# transaction associated with the connection is terminated. The +# default is 15 minutes. +#Default: +# write_timeout 15 minutes + +# TAG: request_timeout +# How long to wait for complete HTTP request headers after initial +# connection establishment. +#Default: +# request_timeout 5 minutes + +# TAG: client_idle_pconn_timeout +# How long to wait for the next HTTP request on a persistent +# client connection after the previous request completes. +#Default: +# client_idle_pconn_timeout 2 minutes + +# TAG: ftp_client_idle_timeout +# How long to wait for an FTP request on a connection to Squid ftp_port. +# Many FTP clients do not deal with idle connection closures well, +# necessitating a longer default timeout than client_idle_pconn_timeout +# used for incoming HTTP requests. +#Default: +# ftp_client_idle_timeout 30 minutes + +# TAG: client_lifetime time-units +# The maximum amount of time a client (browser) is allowed to +# remain connected to the cache process. This protects the Cache +# from having a lot of sockets (and hence file descriptors) tied up +# in a CLOSE_WAIT state from remote clients that go away without +# properly shutting down (either because of a network failure or +# because of a poor client implementation). The default is one +# day, 1440 minutes. +# +# NOTE: The default value is intended to be much larger than any +# client would ever need to be connected to your cache. You +# should probably change client_lifetime only as a last resort. +# If you seem to have many client connections tying up +# filedescriptors, we recommend first tuning the read_timeout, +# request_timeout, persistent_request_timeout and quick_abort values. +#Default: +# client_lifetime 1 day + +# TAG: half_closed_clients +# Some clients may shutdown the sending side of their TCP +# connections, while leaving their receiving sides open. Sometimes, +# Squid can not tell the difference between a half-closed and a +# fully-closed TCP connection. +# +# By default, Squid will immediately close client connections when +# read(2) returns "no more data to read." +# +# Change this option to 'on' and Squid will keep open connections +# until a read(2) or write(2) on the socket returns an error. +# This may show some benefits for reverse proxies. But if not +# it is recommended to leave OFF. +#Default: +# half_closed_clients off + +# TAG: server_idle_pconn_timeout +# Timeout for idle persistent connections to servers and other +# proxies. +#Default: +# server_idle_pconn_timeout 1 minute + +# TAG: ident_timeout +# Maximum time to wait for IDENT lookups to complete. +# +# If this is too high, and you enabled IDENT lookups from untrusted +# users, you might be susceptible to denial-of-service by having +# many ident requests going at once. +#Default: +# ident_timeout 10 seconds + +# TAG: shutdown_lifetime time-units +# When SIGTERM or SIGHUP is received, the cache is put into +# "shutdown pending" mode until all active sockets are closed. +# This value is the lifetime to set for all open descriptors +# during shutdown mode. Any active clients after this many +# seconds will receive a 'timeout' message. +#Default: +# shutdown_lifetime 30 seconds + +# ADMINISTRATIVE PARAMETERS +# ----------------------------------------------------------------------------- + +# TAG: cache_mgr +# Email-address of local cache manager who will receive +# mail if the cache dies. The default is "webmaster". +#Default: +# cache_mgr webmaster + +# TAG: mail_from +# From: email-address for mail sent when the cache dies. +# The default is to use 'squid@unique_hostname'. +# +# See also: unique_hostname directive. +#Default: +# none + +# TAG: mail_program +# Email program used to send mail if the cache dies. +# The default is "mail". The specified program must comply +# with the standard Unix mail syntax: +# mail-program recipient < mailfile +# +# Optional command line options can be specified. +#Default: +# mail_program mail + +# TAG: cache_effective_user +# If you start Squid as root, it will change its effective/real +# UID/GID to the user specified below. The default is to change +# to UID of proxy. +# see also; cache_effective_group +#Default: +# cache_effective_user proxy + +# TAG: cache_effective_group +# Squid sets the GID to the effective user's default group ID +# (taken from the password file) and supplementary group list +# from the groups membership. +# +# If you want Squid to run with a specific GID regardless of +# the group memberships of the effective user then set this +# to the group (or GID) you want Squid to run as. When set +# all other group privileges of the effective user are ignored +# and only this GID is effective. If Squid is not started as +# root the user starting Squid MUST be member of the specified +# group. +# +# This option is not recommended by the Squid Team. +# Our preference is for administrators to configure a secure +# user account for squid with UID/GID matching system policies. +#Default: +# Use system group memberships of the cache_effective_user account + +# TAG: httpd_suppress_version_string on|off +# Suppress Squid version string info in HTTP headers and HTML error pages. +#Default: +# httpd_suppress_version_string off + +# TAG: visible_hostname +# If you want to present a special hostname in error messages, etc, +# define this. Otherwise, the return value of gethostname() +# will be used. If you have multiple caches in a cluster and +# get errors about IP-forwarding you must set them to have individual +# names with this setting. +#Default: +# Automatically detect the system host name + +# TAG: unique_hostname +# If you want to have multiple machines with the same +# 'visible_hostname' you must give each machine a different +# 'unique_hostname' so forwarding loops can be detected. +#Default: +# Copy the value from visible_hostname + +# TAG: hostname_aliases +# A list of other DNS names your cache has. +#Default: +# none + +# TAG: umask +# Minimum umask which should be enforced while the proxy +# is running, in addition to the umask set at startup. +# +# For a traditional octal representation of umasks, start +# your value with 0. +#Default: +# umask 027 + +# OPTIONS FOR THE CACHE REGISTRATION SERVICE +# ----------------------------------------------------------------------------- +# +# This section contains parameters for the (optional) cache +# announcement service. This service is provided to help +# cache administrators locate one another in order to join or +# create cache hierarchies. +# +# An 'announcement' message is sent (via UDP) to the registration +# service by Squid. By default, the announcement message is NOT +# SENT unless you enable it with 'announce_period' below. +# +# The announcement message includes your hostname, plus the +# following information from this configuration file: +# +# http_port +# icp_port +# cache_mgr +# +# All current information is processed regularly and made +# available on the Web at http://www.ircache.net/Cache/Tracker/. + +# TAG: announce_period +# This is how frequently to send cache announcements. +# +# To enable announcing your cache, just set an announce period. +# +# Example: +# announce_period 1 day +#Default: +# Announcement messages disabled. + +# TAG: announce_host +# Set the hostname where announce registration messages will be sent. +# +# See also announce_port and announce_file +#Default: +# announce_host tracker.ircache.net + +# TAG: announce_file +# The contents of this file will be included in the announce +# registration messages. +#Default: +# none + +# TAG: announce_port +# Set the port where announce registration messages will be sent. +# +# See also announce_host and announce_file +#Default: +# announce_port 3131 + +# HTTPD-ACCELERATOR OPTIONS +# ----------------------------------------------------------------------------- + +# TAG: httpd_accel_surrogate_id +# Surrogates (http://www.esi.org/architecture_spec_1.0.html) +# need an identification token to allow control targeting. Because +# a farm of surrogates may all perform the same tasks, they may share +# an identification token. +#Default: +# visible_hostname is used if no specific ID is set. + +# TAG: http_accel_surrogate_remote on|off +# Remote surrogates (such as those in a CDN) honour the header +# "Surrogate-Control: no-store-remote". +# +# Set this to on to have squid behave as a remote surrogate. +#Default: +# http_accel_surrogate_remote off + +# TAG: esi_parser libxml2|expat|custom +# ESI markup is not strictly XML compatible. The custom ESI parser +# will give higher performance, but cannot handle non ASCII character +# encodings. +#Default: +# esi_parser custom + +# DELAY POOL PARAMETERS +# ----------------------------------------------------------------------------- + +# TAG: delay_pools +# This represents the number of delay pools to be used. For example, +# if you have one class 2 delay pool and one class 3 delays pool, you +# have a total of 2 delay pools. +# +# See also delay_parameters, delay_class, delay_access for pool +# configuration details. +#Default: +# delay_pools 0 + +# TAG: delay_class +# This defines the class of each delay pool. There must be exactly one +# delay_class line for each delay pool. For example, to define two +# delay pools, one of class 2 and one of class 3, the settings above +# and here would be: +# +# Example: +# delay_pools 4 # 4 delay pools +# delay_class 1 2 # pool 1 is a class 2 pool +# delay_class 2 3 # pool 2 is a class 3 pool +# delay_class 3 4 # pool 3 is a class 4 pool +# delay_class 4 5 # pool 4 is a class 5 pool +# +# The delay pool classes are: +# +# class 1 Everything is limited by a single aggregate +# bucket. +# +# class 2 Everything is limited by a single aggregate +# bucket as well as an "individual" bucket chosen +# from bits 25 through 32 of the IPv4 address. +# +# class 3 Everything is limited by a single aggregate +# bucket as well as a "network" bucket chosen +# from bits 17 through 24 of the IP address and a +# "individual" bucket chosen from bits 17 through +# 32 of the IPv4 address. +# +# class 4 Everything in a class 3 delay pool, with an +# additional limit on a per user basis. This +# only takes effect if the username is established +# in advance - by forcing authentication in your +# http_access rules. +# +# class 5 Requests are grouped according their tag (see +# external_acl's tag= reply). +# +# +# Each pool also requires a delay_parameters directive to configure the pool size +# and speed limits used whenever the pool is applied to a request. Along with +# a set of delay_access directives to determine when it is used. +# +# NOTE: If an IP address is a.b.c.d +# -> bits 25 through 32 are "d" +# -> bits 17 through 24 are "c" +# -> bits 17 through 32 are "c * 256 + d" +# +# NOTE-2: Due to the use of bitmasks in class 2,3,4 pools they only apply to +# IPv4 traffic. Class 1 and 5 pools may be used with IPv6 traffic. +# +# This clause only supports fast acl types. +# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details. +# +# See also delay_parameters and delay_access. +#Default: +# none + +# TAG: delay_access +# This is used to determine which delay pool a request falls into. +# +# delay_access is sorted per pool and the matching starts with pool 1, +# then pool 2, ..., and finally pool N. The first delay pool where the +# request is allowed is selected for the request. If it does not allow +# the request to any pool then the request is not delayed (default). +# +# For example, if you want some_big_clients in delay +# pool 1 and lotsa_little_clients in delay pool 2: +# +# delay_access 1 allow some_big_clients +# delay_access 1 deny all +# delay_access 2 allow lotsa_little_clients +# delay_access 2 deny all +# delay_access 3 allow authenticated_clients +# +# See also delay_parameters and delay_class. +# +#Default: +# Deny using the pool, unless allow rules exist in squid.conf for the pool. + +# TAG: delay_parameters +# This defines the parameters for a delay pool. Each delay pool has +# a number of "buckets" associated with it, as explained in the +# description of delay_class. +# +# For a class 1 delay pool, the syntax is: +# delay_class pool 1 +# delay_parameters pool aggregate +# +# For a class 2 delay pool: +# delay_class pool 2 +# delay_parameters pool aggregate individual +# +# For a class 3 delay pool: +# delay_class pool 3 +# delay_parameters pool aggregate network individual +# +# For a class 4 delay pool: +# delay_class pool 4 +# delay_parameters pool aggregate network individual user +# +# For a class 5 delay pool: +# delay_class pool 5 +# delay_parameters pool tagrate +# +# The option variables are: +# +# pool a pool number - ie, a number between 1 and the +# number specified in delay_pools as used in +# delay_class lines. +# +# aggregate the speed limit parameters for the aggregate bucket +# (class 1, 2, 3). +# +# individual the speed limit parameters for the individual +# buckets (class 2, 3). +# +# network the speed limit parameters for the network buckets +# (class 3). +# +# user the speed limit parameters for the user buckets +# (class 4). +# +# tagrate the speed limit parameters for the tag buckets +# (class 5). +# +# A pair of delay parameters is written restore/maximum, where restore is +# the number of bytes (not bits - modem and network speeds are usually +# quoted in bits) per second placed into the bucket, and maximum is the +# maximum number of bytes which can be in the bucket at any time. +# +# There must be one delay_parameters line for each delay pool. +# +# +# For example, if delay pool number 1 is a class 2 delay pool as in the +# above example, and is being used to strictly limit each host to 64Kbit/sec +# (plus overheads), with no overall limit, the line is: +# +# delay_parameters 1 none 8000/8000 +# +# Note that 8 x 8K Byte/sec -> 64K bit/sec. +# +# Note that the word 'none' is used to represent no limit. +# +# +# And, if delay pool number 2 is a class 3 delay pool as in the above +# example, and you want to limit it to a total of 256Kbit/sec (strict limit) +# with each 8-bit network permitted 64Kbit/sec (strict limit) and each +# individual host permitted 4800bit/sec with a bucket maximum size of 64Kbits +# to permit a decent web page to be downloaded at a decent speed +# (if the network is not being limited due to overuse) but slow down +# large downloads more significantly: +# +# delay_parameters 2 32000/32000 8000/8000 600/8000 +# +# Note that 8 x 32K Byte/sec -> 256K bit/sec. +# 8 x 8K Byte/sec -> 64K bit/sec. +# 8 x 600 Byte/sec -> 4800 bit/sec. +# +# +# Finally, for a class 4 delay pool as in the example - each user will +# be limited to 128Kbits/sec no matter how many workstations they are logged into.: +# +# delay_parameters 4 32000/32000 8000/8000 600/64000 16000/16000 +# +# +# See also delay_class and delay_access. +# +#Default: +# none + +# TAG: delay_initial_bucket_level (percent, 0-100) +# The initial bucket percentage is used to determine how much is put +# in each bucket when squid starts, is reconfigured, or first notices +# a host accessing it (in class 2 and class 3, individual hosts and +# networks only have buckets associated with them once they have been +# "seen" by squid). +#Default: +# delay_initial_bucket_level 50 + +# CLIENT DELAY POOL PARAMETERS +# ----------------------------------------------------------------------------- + +# TAG: client_delay_pools +# This option specifies the number of client delay pools used. It must +# preceed other client_delay_* options. +# +# Example: +# client_delay_pools 2 +# +# See also client_delay_parameters and client_delay_access. +#Default: +# client_delay_pools 0 + +# TAG: client_delay_initial_bucket_level (percent, 0-no_limit) +# This option determines the initial bucket size as a percentage of +# max_bucket_size from client_delay_parameters. Buckets are created +# at the time of the "first" connection from the matching IP. Idle +# buckets are periodically deleted up. +# +# You can specify more than 100 percent but note that such "oversized" +# buckets are not refilled until their size goes down to max_bucket_size +# from client_delay_parameters. +# +# Example: +# client_delay_initial_bucket_level 50 +#Default: +# client_delay_initial_bucket_level 50 + +# TAG: client_delay_parameters +# +# This option configures client-side bandwidth limits using the +# following format: +# +# client_delay_parameters pool speed_limit max_bucket_size +# +# pool is an integer ID used for client_delay_access matching. +# +# speed_limit is bytes added to the bucket per second. +# +# max_bucket_size is the maximum size of a bucket, enforced after any +# speed_limit additions. +# +# Please see the delay_parameters option for more information and +# examples. +# +# Example: +# client_delay_parameters 1 1024 2048 +# client_delay_parameters 2 51200 16384 +# +# See also client_delay_access. +# +#Default: +# none + +# TAG: client_delay_access +# This option determines the client-side delay pool for the +# request: +# +# client_delay_access pool_ID allow|deny acl_name +# +# All client_delay_access options are checked in their pool ID +# order, starting with pool 1. The first checked pool with allowed +# request is selected for the request. If no ACL matches or there +# are no client_delay_access options, the request bandwidth is not +# limited. +# +# The ACL-selected pool is then used to find the +# client_delay_parameters for the request. Client-side pools are +# not used to aggregate clients. Clients are always aggregated +# based on their source IP addresses (one bucket per source IP). +# +# This clause only supports fast acl types. +# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details. +# Additionally, only the client TCP connection details are available. +# ACLs testing HTTP properties will not work. +# +# Please see delay_access for more examples. +# +# Example: +# client_delay_access 1 allow low_rate_network +# client_delay_access 2 allow vips_network +# +# +# See also client_delay_parameters and client_delay_pools. +#Default: +# Deny use of the pool, unless allow rules exist in squid.conf for the pool. + +# WCCPv1 AND WCCPv2 CONFIGURATION OPTIONS +# ----------------------------------------------------------------------------- + +# TAG: wccp_router +# Use this option to define your WCCP ``home'' router for +# Squid. +# +# wccp_router supports a single WCCP(v1) router +# +# wccp2_router supports multiple WCCPv2 routers +# +# only one of the two may be used at the same time and defines +# which version of WCCP to use. +#Default: +# WCCP disabled. + +# TAG: wccp2_router +# Use this option to define your WCCP ``home'' router for +# Squid. +# +# wccp_router supports a single WCCP(v1) router +# +# wccp2_router supports multiple WCCPv2 routers +# +# only one of the two may be used at the same time and defines +# which version of WCCP to use. +#Default: +# WCCPv2 disabled. + +# TAG: wccp_version +# This directive is only relevant if you need to set up WCCP(v1) +# to some very old and end-of-life Cisco routers. In all other +# setups it must be left unset or at the default setting. +# It defines an internal version in the WCCP(v1) protocol, +# with version 4 being the officially documented protocol. +# +# According to some users, Cisco IOS 11.2 and earlier only +# support WCCP version 3. If you're using that or an earlier +# version of IOS, you may need to change this value to 3, otherwise +# do not specify this parameter. +#Default: +# wccp_version 4 + +# TAG: wccp2_rebuild_wait +# If this is enabled Squid will wait for the cache dir rebuild to finish +# before sending the first wccp2 HereIAm packet +#Default: +# wccp2_rebuild_wait on + +# TAG: wccp2_forwarding_method +# WCCP2 allows the setting of forwarding methods between the +# router/switch and the cache. Valid values are as follows: +# +# gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel) +# l2 - L2 redirect (forward the packet using Layer 2/MAC rewriting) +# +# Currently (as of IOS 12.4) cisco routers only support GRE. +# Cisco switches only support the L2 redirect assignment method. +#Default: +# wccp2_forwarding_method gre + +# TAG: wccp2_return_method +# WCCP2 allows the setting of return methods between the +# router/switch and the cache for packets that the cache +# decides not to handle. Valid values are as follows: +# +# gre - GRE encapsulation (forward the packet in a GRE/WCCP tunnel) +# l2 - L2 redirect (forward the packet using Layer 2/MAC rewriting) +# +# Currently (as of IOS 12.4) cisco routers only support GRE. +# Cisco switches only support the L2 redirect assignment. +# +# If the "ip wccp redirect exclude in" command has been +# enabled on the cache interface, then it is still safe for +# the proxy server to use a l2 redirect method even if this +# option is set to GRE. +#Default: +# wccp2_return_method gre + +# TAG: wccp2_assignment_method +# WCCP2 allows the setting of methods to assign the WCCP hash +# Valid values are as follows: +# +# hash - Hash assignment +# mask - Mask assignment +# +# As a general rule, cisco routers support the hash assignment method +# and cisco switches support the mask assignment method. +#Default: +# wccp2_assignment_method hash + +# TAG: wccp2_service +# WCCP2 allows for multiple traffic services. There are two +# types: "standard" and "dynamic". The standard type defines +# one service id - http (id 0). The dynamic service ids can be from +# 51 to 255 inclusive. In order to use a dynamic service id +# one must define the type of traffic to be redirected; this is done +# using the wccp2_service_info option. +# +# The "standard" type does not require a wccp2_service_info option, +# just specifying the service id will suffice. +# +# MD5 service authentication can be enabled by adding +# "password=<password>" to the end of this service declaration. +# +# Examples: +# +# wccp2_service standard 0 # for the 'web-cache' standard service +# wccp2_service dynamic 80 # a dynamic service type which will be +# # fleshed out with subsequent options. +# wccp2_service standard 0 password=foo +#Default: +# Use the 'web-cache' standard service. + +# TAG: wccp2_service_info +# Dynamic WCCPv2 services require further information to define the +# traffic you wish to have diverted. +# +# The format is: +# +# wccp2_service_info <id> protocol=<protocol> flags=<flag>,<flag>.. +# priority=<priority> ports=<port>,<port>.. +# +# The relevant WCCPv2 flags: +# + src_ip_hash, dst_ip_hash +# + source_port_hash, dst_port_hash +# + src_ip_alt_hash, dst_ip_alt_hash +# + src_port_alt_hash, dst_port_alt_hash +# + ports_source +# +# The port list can be one to eight entries. +# +# Example: +# +# wccp2_service_info 80 protocol=tcp flags=src_ip_hash,ports_source +# priority=240 ports=80 +# +# Note: the service id must have been defined by a previous +# 'wccp2_service dynamic <id>' entry. +#Default: +# none + +# TAG: wccp2_weight +# Each cache server gets assigned a set of the destination +# hash proportional to their weight. +#Default: +# wccp2_weight 10000 + +# TAG: wccp_address +# Use this option if you require WCCPv2 to use a specific +# interface address. +# +# The default behavior is to not bind to any specific address. +#Default: +# Address selected by the operating system. + +# TAG: wccp2_address +# Use this option if you require WCCP to use a specific +# interface address. +# +# The default behavior is to not bind to any specific address. +#Default: +# Address selected by the operating system. + +# PERSISTENT CONNECTION HANDLING +# ----------------------------------------------------------------------------- +# +# Also see "pconn_timeout" in the TIMEOUTS section + +# TAG: client_persistent_connections +# Persistent connection support for clients. +# Squid uses persistent connections (when allowed). You can use +# this option to disable persistent connections with clients. +#Default: +# client_persistent_connections on + +# TAG: server_persistent_connections +# Persistent connection support for servers. +# Squid uses persistent connections (when allowed). You can use +# this option to disable persistent connections with servers. +#Default: +# server_persistent_connections on + +# TAG: persistent_connection_after_error +# With this directive the use of persistent connections after +# HTTP errors can be disabled. Useful if you have clients +# who fail to handle errors on persistent connections proper. +#Default: +# persistent_connection_after_error on + +# TAG: detect_broken_pconn +# Some servers have been found to incorrectly signal the use +# of HTTP/1.0 persistent connections even on replies not +# compatible, causing significant delays. This server problem +# has mostly been seen on redirects. +# +# By enabling this directive Squid attempts to detect such +# broken replies and automatically assume the reply is finished +# after 10 seconds timeout. +#Default: +# detect_broken_pconn off + +# CACHE DIGEST OPTIONS +# ----------------------------------------------------------------------------- + +# TAG: digest_generation +# This controls whether the server will generate a Cache Digest +# of its contents. By default, Cache Digest generation is +# enabled if Squid is compiled with --enable-cache-digests defined. +#Default: +# digest_generation on + +# TAG: digest_bits_per_entry +# This is the number of bits of the server's Cache Digest which +# will be associated with the Digest entry for a given HTTP +# Method and URL (public key) combination. The default is 5. +#Default: +# digest_bits_per_entry 5 + +# TAG: digest_rebuild_period (seconds) +# This is the wait time between Cache Digest rebuilds. +#Default: +# digest_rebuild_period 1 hour + +# TAG: digest_rewrite_period (seconds) +# This is the wait time between Cache Digest writes to +# disk. +#Default: +# digest_rewrite_period 1 hour + +# TAG: digest_swapout_chunk_size (bytes) +# This is the number of bytes of the Cache Digest to write to +# disk at a time. It defaults to 4096 bytes (4KB), the Squid +# default swap page. +#Default: +# digest_swapout_chunk_size 4096 bytes + +# TAG: digest_rebuild_chunk_percentage (percent, 0-100) +# This is the percentage of the Cache Digest to be scanned at a +# time. By default it is set to 10% of the Cache Digest. +#Default: +# digest_rebuild_chunk_percentage 10 + +# SNMP OPTIONS +# ----------------------------------------------------------------------------- + +# TAG: snmp_port +# The port number where Squid listens for SNMP requests. To enable +# SNMP support set this to a suitable port number. Port number +# 3401 is often used for the Squid SNMP agent. By default it's +# set to "0" (disabled) +# +# Example: +# snmp_port 3401 +#Default: +# SNMP disabled. + +# TAG: snmp_access +# Allowing or denying access to the SNMP port. +# +# All access to the agent is denied by default. +# usage: +# +# snmp_access allow|deny [!]aclname ... +# +# This clause only supports fast acl types. +# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details. +# +#Example: +# snmp_access allow snmppublic localhost +# snmp_access deny all +#Default: +# Deny, unless rules exist in squid.conf. + +# TAG: snmp_incoming_address +# Just like 'udp_incoming_address', but for the SNMP port. +# +# snmp_incoming_address is used for the SNMP socket receiving +# messages from SNMP agents. +# +# The default snmp_incoming_address is to listen on all +# available network interfaces. +#Default: +# Accept SNMP packets from all machine interfaces. + +# TAG: snmp_outgoing_address +# Just like 'udp_outgoing_address', but for the SNMP port. +# +# snmp_outgoing_address is used for SNMP packets returned to SNMP +# agents. +# +# If snmp_outgoing_address is not set it will use the same socket +# as snmp_incoming_address. Only change this if you want to have +# SNMP replies sent using another address than where this Squid +# listens for SNMP queries. +# +# NOTE, snmp_incoming_address and snmp_outgoing_address can not have +# the same value since they both use the same port. +#Default: +# Use snmp_incoming_address or an address selected by the operating system. + +# ICP OPTIONS +# ----------------------------------------------------------------------------- + +# TAG: icp_port +# The port number where Squid sends and receives ICP queries to +# and from neighbor caches. The standard UDP port for ICP is 3130. +# +# Example: +# icp_port 3130 +#Default: +# ICP disabled. + +# TAG: htcp_port +# The port number where Squid sends and receives HTCP queries to +# and from neighbor caches. To turn it on you want to set it to +# 4827. +# +# Example: +# htcp_port 4827 +#Default: +# HTCP disabled. + +# TAG: log_icp_queries on|off +# If set, ICP queries are logged to access.log. You may wish +# do disable this if your ICP load is VERY high to speed things +# up or to simplify log analysis. +#Default: +# log_icp_queries on + +# TAG: udp_incoming_address +# udp_incoming_address is used for UDP packets received from other +# caches. +# +# The default behavior is to not bind to any specific address. +# +# Only change this if you want to have all UDP queries received on +# a specific interface/address. +# +# NOTE: udp_incoming_address is used by the ICP, HTCP, and DNS +# modules. Altering it will affect all of them in the same manner. +# +# see also; udp_outgoing_address +# +# NOTE, udp_incoming_address and udp_outgoing_address can not +# have the same value since they both use the same port. +#Default: +# Accept packets from all machine interfaces. + +# TAG: udp_outgoing_address +# udp_outgoing_address is used for UDP packets sent out to other +# caches. +# +# The default behavior is to not bind to any specific address. +# +# Instead it will use the same socket as udp_incoming_address. +# Only change this if you want to have UDP queries sent using another +# address than where this Squid listens for UDP queries from other +# caches. +# +# NOTE: udp_outgoing_address is used by the ICP, HTCP, and DNS +# modules. Altering it will affect all of them in the same manner. +# +# see also; udp_incoming_address +# +# NOTE, udp_incoming_address and udp_outgoing_address can not +# have the same value since they both use the same port. +#Default: +# Use udp_incoming_address or an address selected by the operating system. + +# TAG: icp_hit_stale on|off +# If you want to return ICP_HIT for stale cache objects, set this +# option to 'on'. If you have sibling relationships with caches +# in other administrative domains, this should be 'off'. If you only +# have sibling relationships with caches under your control, +# it is probably okay to set this to 'on'. +# If set to 'on', your siblings should use the option "allow-miss" +# on their cache_peer lines for connecting to you. +#Default: +# icp_hit_stale off + +# TAG: minimum_direct_hops +# If using the ICMP pinging stuff, do direct fetches for sites +# which are no more than this many hops away. +#Default: +# minimum_direct_hops 4 + +# TAG: minimum_direct_rtt (msec) +# If using the ICMP pinging stuff, do direct fetches for sites +# which are no more than this many rtt milliseconds away. +#Default: +# minimum_direct_rtt 400 + +# TAG: netdb_low +# The low water mark for the ICMP measurement database. +# +# Note: high watermark controlled by netdb_high directive. +# +# These watermarks are counts, not percents. The defaults are +# (low) 900 and (high) 1000. When the high water mark is +# reached, database entries will be deleted until the low +# mark is reached. +#Default: +# netdb_low 900 + +# TAG: netdb_high +# The high water mark for the ICMP measurement database. +# +# Note: low watermark controlled by netdb_low directive. +# +# These watermarks are counts, not percents. The defaults are +# (low) 900 and (high) 1000. When the high water mark is +# reached, database entries will be deleted until the low +# mark is reached. +#Default: +# netdb_high 1000 + +# TAG: netdb_ping_period +# The minimum period for measuring a site. There will be at +# least this much delay between successive pings to the same +# network. The default is five minutes. +#Default: +# netdb_ping_period 5 minutes + +# TAG: query_icmp on|off +# If you want to ask your peers to include ICMP data in their ICP +# replies, enable this option. +# +# If your peer has configured Squid (during compilation) with +# '--enable-icmp' that peer will send ICMP pings to origin server +# sites of the URLs it receives. If you enable this option the +# ICP replies from that peer will include the ICMP data (if available). +# Then, when choosing a parent cache, Squid will choose the parent with +# the minimal RTT to the origin server. When this happens, the +# hierarchy field of the access.log will be +# "CLOSEST_PARENT_MISS". This option is off by default. +#Default: +# query_icmp off + +# TAG: test_reachability on|off +# When this is 'on', ICP MISS replies will be ICP_MISS_NOFETCH +# instead of ICP_MISS if the target host is NOT in the ICMP +# database, or has a zero RTT. +#Default: +# test_reachability off + +# TAG: icp_query_timeout (msec) +# Normally Squid will automatically determine an optimal ICP +# query timeout value based on the round-trip-time of recent ICP +# queries. If you want to override the value determined by +# Squid, set this 'icp_query_timeout' to a non-zero value. This +# value is specified in MILLISECONDS, so, to use a 2-second +# timeout (the old default), you would write: +# +# icp_query_timeout 2000 +#Default: +# Dynamic detection. + +# TAG: maximum_icp_query_timeout (msec) +# Normally the ICP query timeout is determined dynamically. But +# sometimes it can lead to very large values (say 5 seconds). +# Use this option to put an upper limit on the dynamic timeout +# value. Do NOT use this option to always use a fixed (instead +# of a dynamic) timeout value. To set a fixed timeout see the +# 'icp_query_timeout' directive. +#Default: +# maximum_icp_query_timeout 2000 + +# TAG: minimum_icp_query_timeout (msec) +# Normally the ICP query timeout is determined dynamically. But +# sometimes it can lead to very small timeouts, even lower than +# the normal latency variance on your link due to traffic. +# Use this option to put an lower limit on the dynamic timeout +# value. Do NOT use this option to always use a fixed (instead +# of a dynamic) timeout value. To set a fixed timeout see the +# 'icp_query_timeout' directive. +#Default: +# minimum_icp_query_timeout 5 + +# TAG: background_ping_rate time-units +# Controls how often the ICP pings are sent to siblings that +# have background-ping set. +#Default: +# background_ping_rate 10 seconds + +# MULTICAST ICP OPTIONS +# ----------------------------------------------------------------------------- + +# TAG: mcast_groups +# This tag specifies a list of multicast groups which your server +# should join to receive multicasted ICP queries. +# +# NOTE! Be very careful what you put here! Be sure you +# understand the difference between an ICP _query_ and an ICP +# _reply_. This option is to be set only if you want to RECEIVE +# multicast queries. Do NOT set this option to SEND multicast +# ICP (use cache_peer for that). ICP replies are always sent via +# unicast, so this option does not affect whether or not you will +# receive replies from multicast group members. +# +# You must be very careful to NOT use a multicast address which +# is already in use by another group of caches. +# +# If you are unsure about multicast, please read the Multicast +# chapter in the Squid FAQ (http://www.squid-cache.org/FAQ/). +# +# Usage: mcast_groups 239.128.16.128 224.0.1.20 +# +# By default, Squid doesn't listen on any multicast groups. +#Default: +# none + +# TAG: mcast_miss_addr +# Note: This option is only available if Squid is rebuilt with the +# -DMULTICAST_MISS_STREAM define +# +# If you enable this option, every "cache miss" URL will +# be sent out on the specified multicast address. +# +# Do not enable this option unless you are are absolutely +# certain you understand what you are doing. +#Default: +# disabled. + +# TAG: mcast_miss_ttl +# Note: This option is only available if Squid is rebuilt with the +# -DMULTICAST_MISS_STREAM define +# +# This is the time-to-live value for packets multicasted +# when multicasting off cache miss URLs is enabled. By +# default this is set to 'site scope', i.e. 16. +#Default: +# mcast_miss_ttl 16 + +# TAG: mcast_miss_port +# Note: This option is only available if Squid is rebuilt with the +# -DMULTICAST_MISS_STREAM define +# +# This is the port number to be used in conjunction with +# 'mcast_miss_addr'. +#Default: +# mcast_miss_port 3135 + +# TAG: mcast_miss_encode_key +# Note: This option is only available if Squid is rebuilt with the +# -DMULTICAST_MISS_STREAM define +# +# The URLs that are sent in the multicast miss stream are +# encrypted. This is the encryption key. +#Default: +# mcast_miss_encode_key XXXXXXXXXXXXXXXX + +# TAG: mcast_icp_query_timeout (msec) +# For multicast peers, Squid regularly sends out ICP "probes" to +# count how many other peers are listening on the given multicast +# address. This value specifies how long Squid should wait to +# count all the replies. The default is 2000 msec, or 2 +# seconds. +#Default: +# mcast_icp_query_timeout 2000 + +# INTERNAL ICON OPTIONS +# ----------------------------------------------------------------------------- + +# TAG: icon_directory +# Where the icons are stored. These are normally kept in +# /usr/share/squid/icons +#Default: +# icon_directory /usr/share/squid/icons + +# TAG: global_internal_static +# This directive controls is Squid should intercept all requests for +# /squid-internal-static/ no matter which host the URL is requesting +# (default on setting), or if nothing special should be done for +# such URLs (off setting). The purpose of this directive is to make +# icons etc work better in complex cache hierarchies where it may +# not always be possible for all corners in the cache mesh to reach +# the server generating a directory listing. +#Default: +# global_internal_static on + +# TAG: short_icon_urls +# If this is enabled Squid will use short URLs for icons. +# If disabled it will revert to the old behavior of including +# it's own name and port in the URL. +# +# If you run a complex cache hierarchy with a mix of Squid and +# other proxies you may need to disable this directive. +#Default: +# short_icon_urls on + +# ERROR PAGE OPTIONS +# ----------------------------------------------------------------------------- + +# TAG: error_directory +# If you wish to create your own versions of the default +# error files to customize them to suit your company copy +# the error/template files to another directory and point +# this tag at them. +# +# WARNING: This option will disable multi-language support +# on error pages if used. +# +# The squid developers are interested in making squid available in +# a wide variety of languages. If you are making translations for a +# language that Squid does not currently provide please consider +# contributing your translation back to the project. +# http://wiki.squid-cache.org/Translations +# +# The squid developers working on translations are happy to supply drop-in +# translated error files in exchange for any new language contributions. +#Default: +# Send error pages in the clients preferred language + +# TAG: error_default_language +# Set the default language which squid will send error pages in +# if no existing translation matches the clients language +# preferences. +# +# If unset (default) generic English will be used. +# +# The squid developers are interested in making squid available in +# a wide variety of languages. If you are interested in making +# translations for any language see the squid wiki for details. +# http://wiki.squid-cache.org/Translations +#Default: +# Generate English language pages. + +# TAG: error_log_languages +# Log to cache.log what languages users are attempting to +# auto-negotiate for translations. +# +# Successful negotiations are not logged. Only failures +# have meaning to indicate that Squid may need an upgrade +# of its error page translations. +#Default: +# error_log_languages on + +# TAG: err_page_stylesheet +# CSS Stylesheet to pattern the display of Squid default error pages. +# +# For information on CSS see http://www.w3.org/Style/CSS/ +#Default: +# err_page_stylesheet /etc/squid/errorpage.css + +# TAG: err_html_text +# HTML text to include in error messages. Make this a "mailto" +# URL to your admin address, or maybe just a link to your +# organizations Web page. +# +# To include this in your error messages, you must rewrite +# the error template files (found in the "errors" directory). +# Wherever you want the 'err_html_text' line to appear, +# insert a %L tag in the error template file. +#Default: +# none + +# TAG: email_err_data on|off +# If enabled, information about the occurred error will be +# included in the mailto links of the ERR pages (if %W is set) +# so that the email body contains the data. +# Syntax is <A HREF="mailto:%w%W">%w</A> +#Default: +# email_err_data on + +# TAG: deny_info +# Usage: deny_info err_page_name acl +# or deny_info http://... acl +# or deny_info TCP_RESET acl +# +# This can be used to return a ERR_ page for requests which +# do not pass the 'http_access' rules. Squid remembers the last +# acl it evaluated in http_access, and if a 'deny_info' line exists +# for that ACL Squid returns a corresponding error page. +# +# The acl is typically the last acl on the http_access deny line which +# denied access. The exceptions to this rule are: +# - When Squid needs to request authentication credentials. It's then +# the first authentication related acl encountered +# - When none of the http_access lines matches. It's then the last +# acl processed on the last http_access line. +# - When the decision to deny access was made by an adaptation service, +# the acl name is the corresponding eCAP or ICAP service_name. +# +# NP: If providing your own custom error pages with error_directory +# you may also specify them by your custom file name: +# Example: deny_info ERR_CUSTOM_ACCESS_DENIED bad_guys +# +# By defaut Squid will send "403 Forbidden". A different 4xx or 5xx +# may be specified by prefixing the file name with the code and a colon. +# e.g. 404:ERR_CUSTOM_ACCESS_DENIED +# +# Alternatively you can tell Squid to reset the TCP connection +# by specifying TCP_RESET. +# +# Or you can specify an error URL or URL pattern. The browsers will +# get redirected to the specified URL after formatting tags have +# been replaced. Redirect will be done with 302 or 307 according to +# HTTP/1.1 specs. A different 3xx code may be specified by prefixing +# the URL. e.g. 303:http://example.com/ +# +# URL FORMAT TAGS: +# %a - username (if available. Password NOT included) +# %B - FTP path URL +# %e - Error number +# %E - Error description +# %h - Squid hostname +# %H - Request domain name +# %i - Client IP Address +# %M - Request Method +# %o - Message result from external ACL helper +# %p - Request Port number +# %P - Request Protocol name +# %R - Request URL path +# %T - Timestamp in RFC 1123 format +# %U - Full canonical URL from client +# (HTTPS URLs terminate with *) +# %u - Full canonical URL from client +# %w - Admin email from squid.conf +# %x - Error name +# %% - Literal percent (%) code +# +#Default: +# none + +# OPTIONS INFLUENCING REQUEST FORWARDING +# ----------------------------------------------------------------------------- + +# TAG: nonhierarchical_direct +# By default, Squid will send any non-hierarchical requests +# (not cacheable request type) direct to origin servers. +# +# When this is set to "off", Squid will prefer to send these +# requests to parents. +# +# Note that in most configurations, by turning this off you will only +# add latency to these request without any improvement in global hit +# ratio. +# +# This option only sets a preference. If the parent is unavailable a +# direct connection to the origin server may still be attempted. To +# completely prevent direct connections use never_direct. +#Default: +# nonhierarchical_direct on + +# TAG: prefer_direct +# Normally Squid tries to use parents for most requests. If you for some +# reason like it to first try going direct and only use a parent if +# going direct fails set this to on. +# +# By combining nonhierarchical_direct off and prefer_direct on you +# can set up Squid to use a parent as a backup path if going direct +# fails. +# +# Note: If you want Squid to use parents for all requests see +# the never_direct directive. prefer_direct only modifies how Squid +# acts on cacheable requests. +#Default: +# prefer_direct off + +# TAG: cache_miss_revalidate on|off +# RFC 7232 defines a conditional request mechanism to prevent +# response objects being unnecessarily transferred over the network. +# If that mechanism is used by the client and a cache MISS occurs +# it can prevent new cache entries being created. +# +# This option determines whether Squid on cache MISS will pass the +# client revalidation request to the server or tries to fetch new +# content for caching. It can be useful while the cache is mostly +# empty to more quickly have the cache populated by generating +# non-conditional GETs. +# +# When set to 'on' (default), Squid will pass all client If-* headers +# to the server. This permits server responses without a cacheable +# payload to be delivered and on MISS no new cache entry is created. +# +# When set to 'off' and if the request is cacheable, Squid will +# remove the clients If-Modified-Since and If-None-Match headers from +# the request sent to the server. This requests a 200 status response +# from the server to create a new cache entry with. +#Default: +# cache_miss_revalidate on + +# TAG: always_direct +# Usage: always_direct allow|deny [!]aclname ... +# +# Here you can use ACL elements to specify requests which should +# ALWAYS be forwarded by Squid to the origin servers without using +# any peers. For example, to always directly forward requests for +# local servers ignoring any parents or siblings you may have use +# something like: +# +# acl local-servers dstdomain my.domain.net +# always_direct allow local-servers +# +# To always forward FTP requests directly, use +# +# acl FTP proto FTP +# always_direct allow FTP +# +# NOTE: There is a similar, but opposite option named +# 'never_direct'. You need to be aware that "always_direct deny +# foo" is NOT the same thing as "never_direct allow foo". You +# may need to use a deny rule to exclude a more-specific case of +# some other rule. Example: +# +# acl local-external dstdomain external.foo.net +# acl local-servers dstdomain .foo.net +# always_direct deny local-external +# always_direct allow local-servers +# +# NOTE: If your goal is to make the client forward the request +# directly to the origin server bypassing Squid then this needs +# to be done in the client configuration. Squid configuration +# can only tell Squid how Squid should fetch the object. +# +# NOTE: This directive is not related to caching. The replies +# is cached as usual even if you use always_direct. To not cache +# the replies see the 'cache' directive. +# +# This clause supports both fast and slow acl types. +# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details. +#Default: +# Prevent any cache_peer being used for this request. + +# TAG: never_direct +# Usage: never_direct allow|deny [!]aclname ... +# +# never_direct is the opposite of always_direct. Please read +# the description for always_direct if you have not already. +# +# With 'never_direct' you can use ACL elements to specify +# requests which should NEVER be forwarded directly to origin +# servers. For example, to force the use of a proxy for all +# requests, except those in your local domain use something like: +# +# acl local-servers dstdomain .foo.net +# never_direct deny local-servers +# never_direct allow all +# +# or if Squid is inside a firewall and there are local intranet +# servers inside the firewall use something like: +# +# acl local-intranet dstdomain .foo.net +# acl local-external dstdomain external.foo.net +# always_direct deny local-external +# always_direct allow local-intranet +# never_direct allow all +# +# This clause supports both fast and slow acl types. +# See http://wiki.squid-cache.org/SquidFaq/SquidAcl for details. +#Default: +# Allow DNS results to be used for this request. + +# ADVANCED NETWORKING OPTIONS +# ----------------------------------------------------------------------------- + +# TAG: incoming_udp_average +# Heavy voodoo here. I can't even believe you are reading this. +# Are you crazy? Don't even think about adjusting these unless +# you understand the algorithms in comm_select.c first! +#Default: +# incoming_udp_average 6 + +# TAG: incoming_tcp_average +# Heavy voodoo here. I can't even believe you are reading this. +# Are you crazy? Don't even think about adjusting these unless +# you understand the algorithms in comm_select.c first! +#Default: +# incoming_tcp_average 4 + +# TAG: incoming_dns_average +# Heavy voodoo here. I can't even believe you are reading this. +# Are you crazy? Don't even think about adjusting these unless +# you understand the algorithms in comm_select.c first! +#Default: +# incoming_dns_average 4 + +# TAG: min_udp_poll_cnt +# Heavy voodoo here. I can't even believe you are reading this. +# Are you crazy? Don't even think about adjusting these unless +# you understand the algorithms in comm_select.c first! +#Default: +# min_udp_poll_cnt 8 + +# TAG: min_dns_poll_cnt +# Heavy voodoo here. I can't even believe you are reading this. +# Are you crazy? Don't even think about adjusting these unless +# you understand the algorithms in comm_select.c first! +#Default: +# min_dns_poll_cnt 8 + +# TAG: min_tcp_poll_cnt +# Heavy voodoo here. I can't even believe you are reading this. +# Are you crazy? Don't even think about adjusting these unless +# you understand the algorithms in comm_select.c first! +#Default: +# min_tcp_poll_cnt 8 + +# TAG: accept_filter +# FreeBSD: +# +# The name of an accept(2) filter to install on Squid's +# listen socket(s). This feature is perhaps specific to +# FreeBSD and requires support in the kernel. +# +# The 'httpready' filter delays delivering new connections +# to Squid until a full HTTP request has been received. +# See the accf_http(9) man page for details. +# +# The 'dataready' filter delays delivering new connections +# to Squid until there is some data to process. +# See the accf_dataready(9) man page for details. +# +# Linux: +# +# The 'data' filter delays delivering of new connections +# to Squid until there is some data to process by TCP_ACCEPT_DEFER. +# You may optionally specify a number of seconds to wait by +# 'data=N' where N is the number of seconds. Defaults to 30 +# if not specified. See the tcp(7) man page for details. +#EXAMPLE: +## FreeBSD +#accept_filter httpready +## Linux +#accept_filter data +#Default: +# none + +# TAG: client_ip_max_connections +# Set an absolute limit on the number of connections a single +# client IP can use. Any more than this and Squid will begin to drop +# new connections from the client until it closes some links. +# +# Note that this is a global limit. It affects all HTTP, HTCP, Gopher and FTP +# connections from the client. For finer control use the ACL access controls. +# +# Requires client_db to be enabled (the default). +# +# WARNING: This may noticably slow down traffic received via external proxies +# or NAT devices and cause them to rebound error messages back to their clients. +#Default: +# No limit. + +# TAG: tcp_recv_bufsize (bytes) +# Size of receive buffer to set for TCP sockets. Probably just +# as easy to change your kernel's default. +# Omit from squid.conf to use the default buffer size. +#Default: +# Use operating system TCP defaults. + +# ICAP OPTIONS +# ----------------------------------------------------------------------------- + +# TAG: icap_enable on|off +# If you want to enable the ICAP module support, set this to on. +#Default: +# icap_enable off + +# TAG: icap_connect_timeout +# This parameter specifies how long to wait for the TCP connect to +# the requested ICAP server to complete before giving up and either +# terminating the HTTP transaction or bypassing the failure. +# +# The default for optional services is peer_connect_timeout. +# The default for essential services is connect_timeout. +# If this option is explicitly set, its value applies to all services. +#Default: +# none + +# TAG: icap_io_timeout time-units +# This parameter specifies how long to wait for an I/O activity on +# an established, active ICAP connection before giving up and +# either terminating the HTTP transaction or bypassing the +# failure. +#Default: +# Use read_timeout. + +# TAG: icap_service_failure_limit limit [in memory-depth time-units] +# The limit specifies the number of failures that Squid tolerates +# when establishing a new TCP connection with an ICAP service. If +# the number of failures exceeds the limit, the ICAP service is +# not used for new ICAP requests until it is time to refresh its +# OPTIONS. +# +# A negative value disables the limit. Without the limit, an ICAP +# service will not be considered down due to connectivity failures +# between ICAP OPTIONS requests. +# +# Squid forgets ICAP service failures older than the specified +# value of memory-depth. The memory fading algorithm +# is approximate because Squid does not remember individual +# errors but groups them instead, splitting the option +# value into ten time slots of equal length. +# +# When memory-depth is 0 and by default this option has no +# effect on service failure expiration. +# +# Squid always forgets failures when updating service settings +# using an ICAP OPTIONS transaction, regardless of this option +# setting. +# +# For example, +# # suspend service usage after 10 failures in 5 seconds: +# icap_service_failure_limit 10 in 5 seconds +#Default: +# icap_service_failure_limit 10 + +# TAG: icap_service_revival_delay +# The delay specifies the number of seconds to wait after an ICAP +# OPTIONS request failure before requesting the options again. The +# failed ICAP service is considered "down" until fresh OPTIONS are +# fetched. +# +# The actual delay cannot be smaller than the hardcoded minimum +# delay of 30 seconds. +#Default: +# icap_service_revival_delay 180 + +# TAG: icap_preview_enable on|off +# The ICAP Preview feature allows the ICAP server to handle the +# HTTP message by looking only at the beginning of the message body +# or even without receiving the body at all. In some environments, +# previews greatly speedup ICAP processing. +# +# During an ICAP OPTIONS transaction, the server may tell Squid what +# HTTP messages should be previewed and how big the preview should be. +# Squid will not use Preview if the server did not request one. +# +# To disable ICAP Preview for all ICAP services, regardless of +# individual ICAP server OPTIONS responses, set this option to "off". +#Example: +#icap_preview_enable off +#Default: +# icap_preview_enable on + +# TAG: icap_preview_size +# The default size of preview data to be sent to the ICAP server. +# This value might be overwritten on a per server basis by OPTIONS requests. +#Default: +# No preview sent. + +# TAG: icap_206_enable on|off +# 206 (Partial Content) responses is an ICAP extension that allows the +# ICAP agents to optionally combine adapted and original HTTP message +# content. The decision to combine is postponed until the end of the +# ICAP response. Squid supports Partial Content extension by default. +# +# Activation of the Partial Content extension is negotiated with each +# ICAP service during OPTIONS exchange. Most ICAP servers should handle +# negotation correctly even if they do not support the extension, but +# some might fail. To disable Partial Content support for all ICAP +# services and to avoid any negotiation, set this option to "off". +# +# Example: +# icap_206_enable off +#Default: +# icap_206_enable on + +# TAG: icap_default_options_ttl +# The default TTL value for ICAP OPTIONS responses that don't have +# an Options-TTL header. +#Default: +# icap_default_options_ttl 60 + +# TAG: icap_persistent_connections on|off +# Whether or not Squid should use persistent connections to +# an ICAP server. +#Default: +# icap_persistent_connections on + +# TAG: adaptation_send_client_ip on|off +# If enabled, Squid shares HTTP client IP information with adaptation +# services. For ICAP, Squid adds the X-Client-IP header to ICAP requests. +# For eCAP, Squid sets the libecap::metaClientIp transaction option. +# +# See also: adaptation_uses_indirect_client +#Default: +# adaptation_send_client_ip off + +# TAG: adaptation_send_username on|off +# This sends authenticated HTTP client username (if available) to +# the adaptation service. +# +# For ICAP, the username value is encoded based on the +# icap_client_username_encode option and is sent using the header +# specified by the icap_client_username_header option. +#Default: +# adaptation_send_username off + +# TAG: icap_client_username_header +# ICAP request header name to use for adaptation_send_username. +#Default: +# icap_client_username_header X-Client-Username + +# TAG: icap_client_username_encode on|off +# Whether to base64 encode the authenticated client username. +#Default: +# icap_client_username_encode off + +# TAG: icap_service +# Defines a single ICAP service using the following format: +# +# icap_service id vectoring_point uri [option ...] +# +# id: ID +# an opaque identifier or name which is used to direct traffic to +# this specific service. Must be unique among all adaptation +# services in squid.conf. +# +# vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache +# This specifies at which point of transaction processing the +# ICAP service should be activated. *_postcache vectoring points +# are not yet supported. +# +# uri: icap://servername:port/servicepath +# ICAP server and service location. +# +# ICAP does not allow a single service to handle both REQMOD and RESPMOD +# transactions. Squid does not enforce that requirement. You can specify +# services with the same service_url and different vectoring_points. You +# can even specify multiple identical services as long as their +# service_names differ. +# +# To activate a service, use the adaptation_access directive. To group +# services, use adaptation_service_chain and adaptation_service_set. +# +# Service options are separated by white space. ICAP services support +# the following name=value options: +# +# bypass=on|off|1|0 +# If set to 'on' or '1', the ICAP service is treated as +# optional. If the service cannot be reached or malfunctions, +# Squid will try to ignore any errors and process the message as +# if the service was not enabled. No all ICAP errors can be +# bypassed. If set to 0, the ICAP service is treated as +# essential and all ICAP errors will result in an error page +# returned to the HTTP client. +# +# Bypass is off by default: services are treated as essential. +# +# routing=on|off|1|0 +# If set to 'on' or '1', the ICAP service is allowed to +# dynamically change the current message adaptation plan by +# returning a chain of services to be used next. The services +# are specified using the X-Next-Services ICAP response header +# value, formatted as a comma-separated list of service names. +# Each named service should be configured in squid.conf. Other +# services are ignored. An empty X-Next-Services value results +# in an empty plan which ends the current adaptation. +# +# Dynamic adaptation plan may cross or cover multiple supported +# vectoring points in their natural processing order. +# +# Routing is not allowed by default: the ICAP X-Next-Services +# response header is ignored. +# +# ipv6=on|off +# Only has effect on split-stack systems. The default on those systems +# is to use IPv4-only connections. When set to 'on' this option will +# make Squid use IPv6-only connections to contact this ICAP service. +# +# on-overload=block|bypass|wait|force +# If the service Max-Connections limit has been reached, do +# one of the following for each new ICAP transaction: +# * block: send an HTTP error response to the client +# * bypass: ignore the "over-connected" ICAP service +# * wait: wait (in a FIFO queue) for an ICAP connection slot +# * force: proceed, ignoring the Max-Connections limit +# +# In SMP mode with N workers, each worker assumes the service +# connection limit is Max-Connections/N, even though not all +# workers may use a given service. +# +# The default value is "bypass" if service is bypassable, +# otherwise it is set to "wait". +# +# +# max-conn=number +# Use the given number as the Max-Connections limit, regardless +# of the Max-Connections value given by the service, if any. +# +# Older icap_service format without optional named parameters is +# deprecated but supported for backward compatibility. +# +#Example: +#icap_service svcBlocker reqmod_precache icap://icap1.mydomain.net:1344/reqmod bypass=0 +#icap_service svcLogger reqmod_precache icap://icap2.mydomain.net:1344/respmod routing=on +#Default: +# none + +# TAG: icap_class +# This deprecated option was documented to define an ICAP service +# chain, even though it actually defined a set of similar, redundant +# services, and the chains were not supported. +# +# To define a set of redundant services, please use the +# adaptation_service_set directive. For service chains, use +# adaptation_service_chain. +#Default: +# none + +# TAG: icap_access +# This option is deprecated. Please use adaptation_access, which +# has the same ICAP functionality, but comes with better +# documentation, and eCAP support. +#Default: +# none + +# eCAP OPTIONS +# ----------------------------------------------------------------------------- + +# TAG: ecap_enable on|off +# Controls whether eCAP support is enabled. +#Default: +# ecap_enable off + +# TAG: ecap_service +# Defines a single eCAP service +# +# ecap_service id vectoring_point uri [option ...] +# +# id: ID +# an opaque identifier or name which is used to direct traffic to +# this specific service. Must be unique among all adaptation +# services in squid.conf. +# +# vectoring_point: reqmod_precache|reqmod_postcache|respmod_precache|respmod_postcache +# This specifies at which point of transaction processing the +# eCAP service should be activated. *_postcache vectoring points +# are not yet supported. +# +# uri: ecap://vendor/service_name?custom&cgi=style¶meters=optional +# Squid uses the eCAP service URI to match this configuration +# line with one of the dynamically loaded services. Each loaded +# eCAP service must have a unique URI. Obtain the right URI from +# the service provider. +# +# To activate a service, use the adaptation_access directive. To group +# services, use adaptation_service_chain and adaptation_service_set. +# +# Service options are separated by white space. eCAP services support +# the following name=value options: +# +# bypass=on|off|1|0 +# If set to 'on' or '1', the eCAP service is treated as optional. +# If the service cannot be reached or malfunctions, Squid will try +# to ignore any errors and process the message as if the service +# was not enabled. No all eCAP errors can be bypassed. +# If set to 'off' or '0', the eCAP service is treated as essential +# and all eCAP errors will result in an error page returned to the +# HTTP client. +# +# Bypass is off by default: services are treated as essential. +# +# routing=on|off|1|0 +# If set to 'on' or '1', the eCAP service is allowed to +# dynamically change the current message adaptation plan by +# returning a chain of services to be used next. +# +# Dynamic adaptation plan may cross or cover multiple supported +# vectoring points in their natural processing order. +# +# Routing is not allowed by default. +# +# Older ecap_service format without optional named parameters is +# deprecated but supported for backward compatibility. +# +# +#Example: +#ecap_service s1 reqmod_precache ecap://filters.R.us/leakDetector?on_error=block bypass=off +#ecap_service s2 respmod_precache ecap://filters.R.us/virusFilter config=/etc/vf.cfg bypass=on +#Default: +# none + +# TAG: loadable_modules +# Instructs Squid to load the specified dynamic module(s) or activate +# preloaded module(s). +#Example: +#loadable_modules /usr/lib/MinimalAdapter.so +#Default: +# none + +# MESSAGE ADAPTATION OPTIONS +# ----------------------------------------------------------------------------- + +# TAG: adaptation_service_set +# +# Configures an ordered set of similar, redundant services. This is +# useful when hot standby or backup adaptation servers are available. +# +# adaptation_service_set set_name service_name1 service_name2 ... +# +# The named services are used in the set declaration order. The first +# applicable adaptation service from the set is used first. The next +# applicable service is tried if and only if the transaction with the +# previous service fails and the message waiting to be adapted is still +# intact. +# +# When adaptation starts, broken services are ignored as if they were +# not a part of the set. A broken service is a down optional service. +# +# The services in a set must be attached to the same vectoring point +# (e.g., pre-cache) and use the same adaptation method (e.g., REQMOD). +# +# If all services in a set are optional then adaptation failures are +# bypassable. If all services in the set are essential, then a +# transaction failure with one service may still be retried using +# another service from the set, but when all services fail, the master +# transaction fails as well. +# +# A set may contain a mix of optional and essential services, but that +# is likely to lead to surprising results because broken services become +# ignored (see above), making previously bypassable failures fatal. +# Technically, it is the bypassability of the last failed service that +# matters. +# +# See also: adaptation_access adaptation_service_chain +# +#Example: +#adaptation_service_set svcBlocker urlFilterPrimary urlFilterBackup +#adaptation service_set svcLogger loggerLocal loggerRemote +#Default: +# none + +# TAG: adaptation_service_chain +# +# Configures a list of complementary services that will be applied +# one-by-one, forming an adaptation chain or pipeline. This is useful +# when Squid must perform different adaptations on the same message. +# +# adaptation_service_chain chain_name service_name1 svc_name2 ... +# +# The named services are used in the chain declaration order. The first +# applicable adaptation service from the chain is used first. The next +# applicable service is applied to the successful adaptation results of +# the previous service in the chain. +# +# When adaptation starts, broken services are ignored as if they were +# not a part of the chain. A broken service is a down optional service. +# +# Request satisfaction terminates the adaptation chain because Squid +# does not currently allow declaration of RESPMOD services at the +# "reqmod_precache" vectoring point (see icap_service or ecap_service). +# +# The services in a chain must be attached to the same vectoring point +# (e.g., pre-cache) and use the same adaptation method (e.g., REQMOD). +# +# A chain may contain a mix of optional and essential services. If an +# essential adaptation fails (or the failure cannot be bypassed for +# other reasons), the master transaction fails. Otherwise, the failure +# is bypassed as if the failed adaptation service was not in the chain. +# +# See also: adaptation_access adaptation_service_set +# +#Example: +#adaptation_service_chain svcRequest requestLogger urlFilter leakDetector +#Default: +# none + +# TAG: adaptation_access +# Sends an HTTP transaction to an ICAP or eCAP adaptation service. +# +# adaptation_access service_name allow|deny [!]aclname... +# adaptation_access set_name allow|deny [!]aclname... +# +# At each supported vectoring point, the adaptation_access +# statements are processed in the order they appear in this +# configuration file. Statements pointing to the following services +# are ignored (i.e., skipped without checking their ACL): +# +# - services serving different vectoring points +# - "broken-but-bypassable" services +# - "up" services configured to ignore such transactions +# (e.g., based on the ICAP Transfer-Ignore header). +# +# When a set_name is used, all services in the set are checked +# using the same rules, to find the first applicable one. See +# adaptation_service_set for details. +# +# If an access list is checked and there is a match, the +# processing stops: For an "allow" rule, the corresponding +# adaptation service is used for the transaction. For a "deny" +# rule, no adaptation service is activated. +# +# It is currently not possible to apply more than one adaptation +# service at the same vectoring point to the same HTTP transaction. +# +# See also: icap_service and ecap_service +# +#Example: +#adaptation_access service_1 allow all +#Default: +# Allow, unless rules exist in squid.conf. + +# TAG: adaptation_service_iteration_limit +# Limits the number of iterations allowed when applying adaptation +# services to a message. If your longest adaptation set or chain +# may have more than 16 services, increase the limit beyond its +# default value of 16. If detecting infinite iteration loops sooner +# is critical, make the iteration limit match the actual number +# of services in your longest adaptation set or chain. +# +# Infinite adaptation loops are most likely with routing services. +# +# See also: icap_service routing=1 +#Default: +# adaptation_service_iteration_limit 16 + +# TAG: adaptation_masterx_shared_names +# For each master transaction (i.e., the HTTP request and response +# sequence, including all related ICAP and eCAP exchanges), Squid +# maintains a table of metadata. The table entries are (name, value) +# pairs shared among eCAP and ICAP exchanges. The table is destroyed +# with the master transaction. +# +# This option specifies the table entry names that Squid must accept +# from and forward to the adaptation transactions. +# +# An ICAP REQMOD or RESPMOD transaction may set an entry in the +# shared table by returning an ICAP header field with a name +# specified in adaptation_masterx_shared_names. +# +# An eCAP REQMOD or RESPMOD transaction may set an entry in the +# shared table by implementing the libecap::visitEachOption() API +# to provide an option with a name specified in +# adaptation_masterx_shared_names. +# +# Squid will store and forward the set entry to subsequent adaptation +# transactions within the same master transaction scope. +# +# Only one shared entry name is supported at this time. +# +#Example: +## share authentication information among ICAP services +#adaptation_masterx_shared_names X-Subscriber-ID +#Default: +# none + +# TAG: adaptation_meta +# This option allows Squid administrator to add custom ICAP request +# headers or eCAP options to Squid ICAP requests or eCAP transactions. +# Use it to pass custom authentication tokens and other +# transaction-state related meta information to an ICAP/eCAP service. +# +# The addition of a meta header is ACL-driven: +# adaptation_meta name value [!]aclname ... +# +# Processing for a given header name stops after the first ACL list match. +# Thus, it is impossible to add two headers with the same name. If no ACL +# lists match for a given header name, no such header is added. For +# example: +# +# # do not debug transactions except for those that need debugging +# adaptation_meta X-Debug 1 needs_debugging +# +# # log all transactions except for those that must remain secret +# adaptation_meta X-Log 1 !keep_secret +# +# # mark transactions from users in the "G 1" group +# adaptation_meta X-Authenticated-Groups "G 1" authed_as_G1 +# +# The "value" parameter may be a regular squid.conf token or a "double +# quoted string". Within the quoted string, use backslash (\) to escape +# any character, which is currently only useful for escaping backslashes +# and double quotes. For example, +# "this string has one backslash (\\) and two \"quotes\"" +# +# Used adaptation_meta header values may be logged via %note +# logformat code. If multiple adaptation_meta headers with the same name +# are used during master transaction lifetime, the header values are +# logged in the order they were used and duplicate values are ignored +# (only the first repeated value will be logged). +#Default: +# none + +# TAG: icap_retry +# This ACL determines which retriable ICAP transactions are +# retried. Transactions that received a complete ICAP response +# and did not have to consume or produce HTTP bodies to receive +# that response are usually retriable. +# +# icap_retry allow|deny [!]aclname ... +# +# Squid automatically retries some ICAP I/O timeouts and errors +# due to persistent connection race conditions. +# +# See also: icap_retry_limit +#Default: +# icap_retry deny all + +# TAG: icap_retry_limit +# Limits the number of retries allowed. +# +# Communication errors due to persistent connection race +# conditions are unavoidable, automatically retried, and do not +# count against this limit. +# +# See also: icap_retry +#Default: +# No retries are allowed. + +# DNS OPTIONS +# ----------------------------------------------------------------------------- + +# TAG: check_hostnames +# For security and stability reasons Squid can check +# hostnames for Internet standard RFC compliance. If you want +# Squid to perform these checks turn this directive on. +#Default: +# check_hostnames off + +# TAG: allow_underscore +# Underscore characters is not strictly allowed in Internet hostnames +# but nevertheless used by many sites. Set this to off if you want +# Squid to be strict about the standard. +# This check is performed only when check_hostnames is set to on. +#Default: +# allow_underscore on + +# TAG: dns_retransmit_interval +# Initial retransmit interval for DNS queries. The interval is +# doubled each time all configured DNS servers have been tried. +#Default: +# dns_retransmit_interval 5 seconds + +# TAG: dns_timeout +# DNS Query timeout. If no response is received to a DNS query +# within this time all DNS servers for the queried domain +# are assumed to be unavailable. +#Default: +# dns_timeout 30 seconds + +# TAG: dns_packet_max +# Maximum number of bytes packet size to advertise via EDNS. +# Set to "none" to disable EDNS large packet support. +# +# For legacy reasons DNS UDP replies will default to 512 bytes which +# is too small for many responses. EDNS provides a means for Squid to +# negotiate receiving larger responses back immediately without having +# to failover with repeat requests. Responses larger than this limit +# will retain the old behaviour of failover to TCP DNS. +# +# Squid has no real fixed limit internally, but allowing packet sizes +# over 1500 bytes requires network jumbogram support and is usually not +# necessary. +# +# WARNING: The RFC also indicates that some older resolvers will reply +# with failure of the whole request if the extension is added. Some +# resolvers have already been identified which will reply with mangled +# EDNS response on occasion. Usually in response to many-KB jumbogram +# sizes being advertised by Squid. +# Squid will currently treat these both as an unable-to-resolve domain +# even if it would be resolvable without EDNS. +#Default: +# EDNS disabled + +# TAG: dns_defnames on|off +# Normally the RES_DEFNAMES resolver option is disabled +# (see res_init(3)). This prevents caches in a hierarchy +# from interpreting single-component hostnames locally. To allow +# Squid to handle single-component names, enable this option. +#Default: +# Search for single-label domain names is disabled. + +# TAG: dns_multicast_local on|off +# When set to on, Squid sends multicast DNS lookups on the local +# network for domains ending in .local and .arpa. +# This enables local servers and devices to be contacted in an +# ad-hoc or zero-configuration network environment. +#Default: +# Search for .local and .arpa names is disabled. + +# TAG: dns_nameservers +# Use this if you want to specify a list of DNS name servers +# (IP addresses) to use instead of those given in your +# /etc/resolv.conf file. +# +# On Windows platforms, if no value is specified here or in +# the /etc/resolv.conf file, the list of DNS name servers are +# taken from the Windows registry, both static and dynamic DHCP +# configurations are supported. +# +# Example: dns_nameservers 10.0.0.1 192.172.0.4 +#Default: +# Use operating system definitions + +# TAG: hosts_file +# Location of the host-local IP name-address associations +# database. Most Operating Systems have such a file on different +# default locations: +# - Un*X & Linux: /etc/hosts +# - Windows NT/2000: %SystemRoot%\system32\drivers\etc\hosts +# (%SystemRoot% value install default is c:\winnt) +# - Windows XP/2003: %SystemRoot%\system32\drivers\etc\hosts +# (%SystemRoot% value install default is c:\windows) +# - Windows 9x/Me: %windir%\hosts +# (%windir% value is usually c:\windows) +# - Cygwin: /etc/hosts +# +# The file contains newline-separated definitions, in the +# form ip_address_in_dotted_form name [name ...] names are +# whitespace-separated. Lines beginning with an hash (#) +# character are comments. +# +# The file is checked at startup and upon configuration. +# If set to 'none', it won't be checked. +# If append_domain is used, that domain will be added to +# domain-local (i.e. not containing any dot character) host +# definitions. +#Default: +# hosts_file /etc/hosts + +# TAG: append_domain +# Appends local domain name to hostnames without any dots in +# them. append_domain must begin with a period. +# +# Be warned there are now Internet names with no dots in +# them using only top-domain names, so setting this may +# cause some Internet sites to become unavailable. +# +#Example: +# append_domain .yourdomain.com +#Default: +# Use operating system definitions + +# TAG: ignore_unknown_nameservers +# By default Squid checks that DNS responses are received +# from the same IP addresses they are sent to. If they +# don't match, Squid ignores the response and writes a warning +# message to cache.log. You can allow responses from unknown +# nameservers by setting this option to 'off'. +#Default: +# ignore_unknown_nameservers on + +# TAG: dns_v4_first +# With the IPv6 Internet being as fast or faster than IPv4 Internet +# for most networks Squid prefers to contact websites over IPv6. +# +# This option reverses the order of preference to make Squid contact +# dual-stack websites over IPv4 first. Squid will still perform both +# IPv6 and IPv4 DNS lookups before connecting. +# +# WARNING: +# This option will restrict the situations under which IPv6 +# connectivity is used (and tested), potentially hiding network +# problems which would otherwise be detected and warned about. +#Default: +# dns_v4_first off + +# TAG: ipcache_size (number of entries) +# Maximum number of DNS IP cache entries. +#Default: +# ipcache_size 1024 + +# TAG: ipcache_low (percent) +#Default: +# ipcache_low 90 + +# TAG: ipcache_high (percent) +# The size, low-, and high-water marks for the IP cache. +#Default: +# ipcache_high 95 + +# TAG: fqdncache_size (number of entries) +# Maximum number of FQDN cache entries. +#Default: +# fqdncache_size 1024 + +# MISCELLANEOUS +# ----------------------------------------------------------------------------- + +# TAG: configuration_includes_quoted_values on|off +# If set, Squid will recognize each "quoted string" after a configuration +# directive as a single parameter. The quotes are stripped before the +# parameter value is interpreted or used. +# See "Values with spaces, quotes, and other special characters" +# section for more details. +#Default: +# configuration_includes_quoted_values off + +# TAG: memory_pools on|off +# If set, Squid will keep pools of allocated (but unused) memory +# available for future use. If memory is a premium on your +# system and you believe your malloc library outperforms Squid +# routines, disable this. +#Default: +# memory_pools on + +# TAG: memory_pools_limit (bytes) +# Used only with memory_pools on: +# memory_pools_limit 50 MB +# +# If set to a non-zero value, Squid will keep at most the specified +# limit of allocated (but unused) memory in memory pools. All free() +# requests that exceed this limit will be handled by your malloc +# library. Squid does not pre-allocate any memory, just safe-keeps +# objects that otherwise would be free()d. Thus, it is safe to set +# memory_pools_limit to a reasonably high value even if your +# configuration will use less memory. +# +# If set to none, Squid will keep all memory it can. That is, there +# will be no limit on the total amount of memory used for safe-keeping. +# +# To disable memory allocation optimization, do not set +# memory_pools_limit to 0 or none. Set memory_pools to "off" instead. +# +# An overhead for maintaining memory pools is not taken into account +# when the limit is checked. This overhead is close to four bytes per +# object kept. However, pools may actually _save_ memory because of +# reduced memory thrashing in your malloc library. +#Default: +# memory_pools_limit 5 MB + +# TAG: forwarded_for on|off|transparent|truncate|delete +# If set to "on", Squid will append your client's IP address +# in the HTTP requests it forwards. By default it looks like: +# +# X-Forwarded-For: 192.1.2.3 +# +# If set to "off", it will appear as +# +# X-Forwarded-For: unknown +# +# If set to "transparent", Squid will not alter the +# X-Forwarded-For header in any way. +# +# If set to "delete", Squid will delete the entire +# X-Forwarded-For header. +# +# If set to "truncate", Squid will remove all existing +# X-Forwarded-For entries, and place the client IP as the sole entry. +#Default: +# forwarded_for on + +# TAG: cachemgr_passwd +# Specify passwords for cachemgr operations. +# +# Usage: cachemgr_passwd password action action ... +# +# Some valid actions are (see cache manager menu for a full list): +# 5min +# 60min +# asndb +# authenticator +# cbdata +# client_list +# comm_incoming +# config * +# counters +# delay +# digest_stats +# dns +# events +# filedescriptors +# fqdncache +# histograms +# http_headers +# info +# io +# ipcache +# mem +# menu +# netdb +# non_peers +# objects +# offline_toggle * +# pconn +# peer_select +# reconfigure * +# redirector +# refresh +# server_list +# shutdown * +# store_digest +# storedir +# utilization +# via_headers +# vm_objects +# +# * Indicates actions which will not be performed without a +# valid password, others can be performed if not listed here. +# +# To disable an action, set the password to "disable". +# To allow performing an action without a password, set the +# password to "none". +# +# Use the keyword "all" to set the same password for all actions. +# +#Example: +# cachemgr_passwd secret shutdown +# cachemgr_passwd lesssssssecret info stats/objects +# cachemgr_passwd disable all +#Default: +# No password. Actions which require password are denied. + +# TAG: client_db on|off +# If you want to disable collecting per-client statistics, +# turn off client_db here. +#Default: +# client_db on + +# TAG: refresh_all_ims on|off +# When you enable this option, squid will always check +# the origin server for an update when a client sends an +# If-Modified-Since request. Many browsers use IMS +# requests when the user requests a reload, and this +# ensures those clients receive the latest version. +# +# By default (off), squid may return a Not Modified response +# based on the age of the cached version. +#Default: +# refresh_all_ims off + +# TAG: reload_into_ims on|off +# When you enable this option, client no-cache or ``reload'' +# requests will be changed to If-Modified-Since requests. +# Doing this VIOLATES the HTTP standard. Enabling this +# feature could make you liable for problems which it +# causes. +# +# see also refresh_pattern for a more selective approach. +#Default: +# reload_into_ims off + +# TAG: connect_retries +# This sets the maximum number of connection attempts made for each +# TCP connection. The connect_retries attempts must all still +# complete within the connection timeout period. +# +# The default is not to re-try if the first connection attempt fails. +# The (not recommended) maximum is 10 tries. +# +# A warning message will be generated if it is set to a too-high +# value and the configured value will be over-ridden. +# +# Note: These re-tries are in addition to forward_max_tries +# which limit how many different addresses may be tried to find +# a useful server. +#Default: +# Do not retry failed connections. + +# TAG: retry_on_error +# If set to ON Squid will automatically retry requests when +# receiving an error response with status 403 (Forbidden), +# 500 (Internal Error), 501 or 503 (Service not available). +# Status 502 and 504 (Gateway errors) are always retried. +# +# This is mainly useful if you are in a complex cache hierarchy to +# work around access control errors. +# +# NOTE: This retry will attempt to find another working destination. +# Which is different from the server which just failed. +#Default: +# retry_on_error off + +# TAG: as_whois_server +# WHOIS server to query for AS numbers. NOTE: AS numbers are +# queried only when Squid starts up, not for every request. +#Default: +# as_whois_server whois.ra.net + +# TAG: offline_mode +# Enable this option and Squid will never try to validate cached +# objects. +#Default: +# offline_mode off + +# TAG: uri_whitespace +# What to do with requests that have whitespace characters in the +# URI. Options: +# +# strip: The whitespace characters are stripped out of the URL. +# This is the behavior recommended by RFC2396 and RFC3986 +# for tolerant handling of generic URI. +# NOTE: This is one difference between generic URI and HTTP URLs. +# +# deny: The request is denied. The user receives an "Invalid +# Request" message. +# This is the behaviour recommended by RFC2616 for safe +# handling of HTTP request URL. +# +# allow: The request is allowed and the URI is not changed. The +# whitespace characters remain in the URI. Note the +# whitespace is passed to redirector processes if they +# are in use. +# Note this may be considered a violation of RFC2616 +# request parsing where whitespace is prohibited in the +# URL field. +# +# encode: The request is allowed and the whitespace characters are +# encoded according to RFC1738. +# +# chop: The request is allowed and the URI is chopped at the +# first whitespace. +# +# +# NOTE the current Squid implementation of encode and chop violates +# RFC2616 by not using a 301 redirect after altering the URL. +#Default: +# uri_whitespace strip + +# TAG: chroot +# Specifies a directory where Squid should do a chroot() while +# initializing. This also causes Squid to fully drop root +# privileges after initializing. This means, for example, if you +# use a HTTP port less than 1024 and try to reconfigure, you may +# get an error saying that Squid can not open the port. +#Default: +# none + +# TAG: balance_on_multiple_ip +# Modern IP resolvers in squid sort lookup results by preferred access. +# By default squid will use these IP in order and only rotates to +# the next listed when the most preffered fails. +# +# Some load balancing servers based on round robin DNS have been +# found not to preserve user session state across requests +# to different IP addresses. +# +# Enabling this directive Squid rotates IP's per request. +#Default: +# balance_on_multiple_ip off + +# TAG: pipeline_prefetch +# HTTP clients may send a pipeline of 1+N requests to Squid using a +# single connection, without waiting for Squid to respond to the first +# of those requests. This option limits the number of concurrent +# requests Squid will try to handle in parallel. If set to N, Squid +# will try to receive and process up to 1+N requests on the same +# connection concurrently. +# +# Defaults to 0 (off) for bandwidth management and access logging +# reasons. +# +# NOTE: pipelining requires persistent connections to clients. +# +# WARNING: pipelining breaks NTLM and Negotiate/Kerberos authentication. +#Default: +# Do not pre-parse pipelined requests. + +# TAG: high_response_time_warning (msec) +# If the one-minute median response time exceeds this value, +# Squid prints a WARNING with debug level 0 to get the +# administrators attention. The value is in milliseconds. +#Default: +# disabled. + +# TAG: high_page_fault_warning +# If the one-minute average page fault rate exceeds this +# value, Squid prints a WARNING with debug level 0 to get +# the administrators attention. The value is in page faults +# per second. +#Default: +# disabled. + +# TAG: high_memory_warning +# Note: This option is only available if Squid is rebuilt with the +# GNU Malloc with mstats() +# +# If the memory usage (as determined by gnumalloc, if available and used) +# exceeds this amount, Squid prints a WARNING with debug level 0 to get +# the administrators attention. +#Default: +# disabled. + +# TAG: sleep_after_fork (microseconds) +# When this is set to a non-zero value, the main Squid process +# sleeps the specified number of microseconds after a fork() +# system call. This sleep may help the situation where your +# system reports fork() failures due to lack of (virtual) +# memory. Note, however, if you have a lot of child +# processes, these sleep delays will add up and your +# Squid will not service requests for some amount of time +# until all the child processes have been started. +# On Windows value less then 1000 (1 milliseconds) are +# rounded to 1000. +#Default: +# sleep_after_fork 0 + +# TAG: windows_ipaddrchangemonitor on|off +# Note: This option is only available if Squid is rebuilt with the +# MS Windows +# +# On Windows Squid by default will monitor IP address changes and will +# reconfigure itself after any detected event. This is very useful for +# proxies connected to internet with dial-up interfaces. +# In some cases (a Proxy server acting as VPN gateway is one) it could be +# desiderable to disable this behaviour setting this to 'off'. +# Note: after changing this, Squid service must be restarted. +#Default: +# windows_ipaddrchangemonitor on + +# TAG: eui_lookup +# Whether to lookup the EUI or MAC address of a connected client. +#Default: +# eui_lookup on + +# TAG: max_filedescriptors +# Reduce the maximum number of filedescriptors supported below +# the usual operating system defaults. +# +# Remove from squid.conf to inherit the current ulimit setting. +# +# Note: Changing this requires a restart of Squid. Also +# not all I/O types supports large values (eg on Windows). +#Default: +# Use operating system limits set by ulimit. + |