RE: [squid-users] Squid not communicating with Helper Processes

From: Christian Zink <bigboyforever_at_hotmail.com>
Date: Mon, 28 Nov 2011 11:29:18 +0100

Finally i've got it!
After searching in the buglist i found a case describing Problems if you use both authentication and external helpers. 
So i tried to disable authentication and use only squid_ldap_group external helper:

auth_param      digest program /usr/lib64/squid/digest_ldap_auth -H ldap://127.0.0.1 -v 3 -e -b "ou=0500,dc=drv,dc=drv" -u "uid" -A "userPassword" -D "uid=digestreader,dc=drv,dc=drv" -W "/etc/squid/digestreader_cred"
auth_param      digest children 1
auth_param      digest realm Proxy
#acl ldap proxy_auth REQUIRED
external_acl_type ldap_group %LOGIN /usr/lib64/squid/squid_ldap_group -H ldap://127.0.0.1 -v 3 -b ou=groups,dc=drv,dc=drv -f (&(memberuid=%u)(cn=%g)) -D uid=digestreader,dc=drv,dc=drv -w digestpw -dacl ldap_download
external ldap_group downloadacl ldap_browse
external ldap_group browse
cache_peer 10.10.1.254 parent 9986 0 no-query no-digest name=download.proxy
cache_peer_access download.proxy deny !ldap_download
cache_peer 10.10.1.254 parent 9985 0 no-query no-digest name=browse.proxy
cache_peer_access browse.proxy allow ldap_browse
http_access allow ldap_download
http_access allow ldap_browse

And voila, not only ldap group check worked, but it also still needed authentication first! I don't know if its a bug, or intended ... but if you use "acl ldap proxy_auth REQUIRED"  there will be no other requestto an external helper again ... without it it works as desired. In my eyes maybe its a feature to also authenticate if i use external_helper,but it should also work with this acl. Perhaps someone could explain the ideas behind this.

Greets Christian Zink

> From: bigboyforever_at_hotmail.com
> To: squid-users_at_squid-cache.org
> Date: Thu, 24 Nov 2011 10:36:52 +0100
> Subject: [squid-users] Squid not communicating with Helper Processes
>
>
> Hi,
> i have a strange problem driving me mad. I set up a fresh RHEL 6.1 System and installedLDAP and Squid. I want do authenticate users and contol the internet access depending on groups. 
> Ldap auth with digest_ldap_auth works fine, but i can't get the squid_ldap_group helper to work.
> My conf:
> #debug_options ALL,9debug_options ALL,1 28,3 82,9 84,9
> hosts_file /etc/hosts
> acl manager proto cache_objectacl localhost src 127.0.0.1/32
> acl SSL_ports port 443 563 888 7002 8443 10000
> 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> http_access allow manager localhost
> http_access deny manager> http_access deny !Safe_ports
> http_access deny CONNECT !SSL_ports
> auth_param      digest program /usr/lib64/squid/digest_ldap_auth -H ldap://127.0.0.1 -v 3 -e -b "ou=0500,dc=drv,dc=drv" -u "uid" -A "userPassword" -D "uid=digestreader,dc=drv,dc=drv" -W "/etc/squid/digestreader_cred"
> auth_param      digest children 1
> auth_param      digest realm Proxy
> acl ldap proxy_auth REQUIRED
>
> #external_acl_type ldap_group %LOGIN /usr/lib64/squid/squid_ldap_group -H ldap://127.0.0.1 -v 3 -b ou=groups,dc=drv,dc=drv -f (&(memberuid=%u)(cn=%g)) -D uid=digestreader,dc=drv,dc=drv -W "/etc/squid/digestreader_cred"
> external_acl_type ldap_group children=1 %LOGIN /usr/lib64/squid/test.sh
> acl ldap_download external ldap_group download
> acl ldap_browse external ldap_group browse
>
> cache_peer 10.10.1.254 parent 9986 0 no-query no-digest name=download.proxy
> cache_peer_access download.proxy allow ldap_download
> cache_peer 10.10.1.254 parent 9985 0 no-query no-digest name=browse.proxy
> cache_peer_access browse.proxy allow browse
>
> http_access allow ldap> http_access deny all
> http_port 8086
>
> The Problem:
> Squid doesnt talk to the Helper Processes! That's all i can see in logs:
> 2011/11/23 17:07:34.219| ACLChecklist::preCheck: 0x7fff8c40cc70 checking 'cache_peer_access download.proxy allow ldap_download'
> 2011/11/23 17:07:34.219| ACLList::matches: checking ldap_download
> 2011/11/23 17:07:34.219| ACL::checklistMatches: checking 'ldap_download'
> 2011/11/23 17:07:34.219| aclMatchExternal: acl="ldap_group"
> 2011/11/23 17:07:34.219| aclMatchExternal: ldap_group("v990493 download") = lookup needed
> 2011/11/23 17:07:34.219| aclMatchExternal: "v990493 download": entry=@0, age=0
> 2011/11/23 17:07:34.219| aclMatchExternal: "v990493 download": queueing a call.
> 2011/11/23 17:07:34.219| aclMatchExternal: "v990493 download": return -1.
> 2011/11/23 17:07:34.219| ACL::ChecklistMatches: result for 'ldap_download' is -1
> 2011/11/23 17:07:34.219| aclmatchAclList: 0x7fff8c40cc70 returning false (AND list entry failed to match)
> 2011/11/23 17:07:34.219| aclmatchAclList: async=0 nodeMatched=0 async_in_progress=0 lastACLResult() = 0 finished() = 0
>
> While this is repeated endlessly i straced the helper Process ... nothing! I also wrote a dummy Helper, also nothing.Tcpdump on localhost i see the packets from digest_ldap_auth to ldap. Squids talking to digest_ldap_auth over Unix Pipe, that works, and form digest_ldap_auth to ldap over 127.0.0.1 works to,but not from Squid to the Helper although there is an TCP Connection:
> squid      1858     squid    8u     IPv6              47834      0t0        UDP *:54597
> squid      1858     squid   14u     IPv6              47840      0t0        TCP [::1]:38965->[::1]:45367 (ESTABLISHED)
> squid      1858     squid   15u     IPv6              47842      0t0        TCP *:d-s-n (LISTEN)
> test.sh   10617     squid    0u     IPv6              47841      0t0        TCP [::1]:45367->[::1]:38965 (ESTABLISHED)
> test.sh   10617     squid    1u     IPv6              47841      0t0        TCP [::1]:45367->[::1]:38965 (ESTABLISHED)
>
> What i tried so far:
> - the squid_ldap_group works on the shell, piping Username & Group result in OK/ERR depending on the ldap group membership
> - no activity in strace on squid_ldap_group, but on digest_ldap_auth
> - no Packets seen with tcpdump on localhost, except from digest_ldap_auth
> - tried many different options of external_acl_type ...
> - no iptables active & SELinux Permissive
> Probably it's a really simple solution, like an internal acl not allowing network access to localhost, but i can't see it and its driving me nuts !!!!
>
> Squid Cache: Version 3.1.10configure options:  '--build=x86_64-redhat-linux-gnu' '--host=x86_64-redhat-linux-gnu' '--target=x86_64-redhat-linux-gnu' '--program-prefix=' '--prefix=/usr' '--exec-prefix=/usr' '--bindir=/usr/bin' '--sbindir=/usr/sbin' '--sysconfdir=/etc' '--datadir=/usr/share' '--includedir=/usr/include' '--libdir=/usr/lib64' '--libexecdir=/usr/libexec' '--sharedstatedir=/var/lib' '--mandir=/usr/share/man' '--infodir=/usr/share/info' '--exec_prefix=/usr' '--libexecdir=/usr/lib64/squid' '--localstatedir=/var' '--datadir=/usr/share/squid' '--sysconfdir=/etc/squid' '--with-logdir=$(localstatedir)/log/squid' '--with-pidfile=$(localstatedir)/run/squid.pid' '--disable-dependency-tracking' '--enable-arp-acl' '--enable-follow-x-forwarded-for' '--enable-auth=basic,digest,ntlm,negotiate' '--enable-basic-auth-helpers=LDAP,MSNT,NCSA,PAM,SMB,YP,getpwnam,multi-domain-NTLM,SASL,DB,POP3,squid_radius_auth' '--enable-ntlm-auth-helpers=smb_lm,no_check,fakeauth' '--enable-digest-auth-helpers=password,ldap,eDirectory' '--enable-negotiate-auth-helpers=squid_kerb_auth' '--enable-external-acl-helpers=ip_user,ldap_group,session,unix_group,wbinfo_group' '--enable-cache-digests' '--enable-cachemgr-hostname=localhost' '--enable-delay-pools' '--enable-epoll' '--enable-icap-client' '--enable-ident-lookups' '--enable-linux-netfilter' '--enable-referer-log' '--enable-removal-policies=heap,lru' '--enable-snmp' '--enable-ssl' '--enable-storeio=aufs,diskd,ufs' '--enable-useragent-log' '--enable-wccpv2' '--enable-esi' '--with-aio' '--with-default-user=squid' '--with-filedescriptors=16384' '--with-dl' '--with-openssl' '--with-pthreads' 'build_alias=x86_64-redhat-linux-gnu' 'host_alias=x86_64-redhat-linux-gnu' 'target_alias=x86_64-redhat-linux-gnu' 'CFLAGS=-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic -fpie' 'LDFLAGS=-pie' 'CXXFLAGS=-O2 -g -pipe -Wall -Wp,-D_FORTIFY_SOURCE=2 -fexceptions -fstack-protector --param=ssp-buffer-size=4 -m64 -mtune=generic -fpie' --with-squid=/builddir/build/BUILD/squid-3.1.10
> Linux squidproxy51.drv.drv 2.6.32-131.17.1.el6.x86_64 #1 SMP Thu Sep 29 10:24:25 EDT 2011 x86_64 x86_64 x86_64 GNU/Linux
>
                                                                                                                                             
Received on Mon Nov 28 2011 - 10:29:29 MST

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