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krisdigitx
Asked: 2011-10-04 05:42:00 +0800 CST

squid bypass for a domain

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I'm using squid with adzap, it's possible that squid/adzap does not cache for a particular domain eg. cnn.com. This is my squid.conf file:

#
# Recommended minimum configuration:
#
acl manager proto cache_object
acl localhost src 127.0.0.1/32
#acl localhost src ::1/128
acl to_localhost dst 127.0.0.0/8 0.0.0.0/32
#acl to_localhost dst ::1/128

# Example rule allowing access from your local networks.
# Adapt to list your (internal) IP networks from where browsing
# should be allowed
acl localnet src 192.168.1.0/24
acl localnet src 192.168.2.0/24

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

#
# Recommended minimum Access Permission configuration:
#
# Only allow cachemgr access from localhost
http_access allow manager localhost
http_access deny manager

# 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

# 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

# Squid normally listens to port 3128
http_port xxx.xxx.xxx.yyy:3128 transparent
visible_hostname proxyserver.local

# We recommend you to use at least the following line.
hierarchy_stoplist cgi-bin ?

# Uncomment and adjust the following to add a disk cache directory.
cache_dir ufs /var/spool/squid 1024 16 256

# Leave coredumps in the first cache dir
coredump_dir /var/spool/squid

# 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 .               0       20%     4320
access_log /var/log/squid/squid.log squid
access_log syslog squid
redirect_program /usr/local/adzap/scripts/wrapzap

fixed using

acl allow_domains dstdomain www.cnn.com
always_direct allow allow_domains
centos squid

3 Answers

  1. I am surprised that always_direct is working. As others said, that only affects cache hierarchies and you don't seem to be using one.

    If you want to control caching, the right configuration option to use is cache (or no_cache, depending on what version of squid you are running).

    E.g.

    Acl dontcache dstdomain .cnn.com
Cache deny dontcache
Cache allow all
    • 2

  2. The Squid directive always_direct says that for the specified ACLs, always connect directly to them, and never connect to an upstream cache. Many filtering proxies are set up as upstream caches, so the filter doesn't have to worry about caching (it delegates that to Squid).

    Your example

    acl allow_domains dstdomain www.cnn.com
always_direct allow allow_domains

    defines an access control list called allow_domains, and adds www.cnn.com to it. (You probably also want to change that to .cnn.com to allow other CNN sites, but not just anything with that suffix, e.g. 'malwarecnn.com'.

    Then, always_direct allow ACL_NAME will tell Squid to ignore the forwarder for that domain.

    (If you answer your own question, please do it by way of an answer. Otherwise, someone will come and add much more detail for the future reader. :)

    • 0

  3. always_direct are used to specify requests which should ALWAYS be forwarded by Squid to the origin servers without using any peers. It's not related to caching. Instead of always_direct you must use something like the following

    acl bypass_caching dstdomain cnn.com
cache deny bypass_caching

    TAG: cache - A list of ACL elements which, if matched, cause the request to not be satisfied from the cache and the reply to not be cached. In other words, use this to force certain objects to never be cached. You must use the word 'DENY' to indicate the ACL names which should NOT be cached.

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