Provided by: squid_3.5.12-1ubuntu7_i386 bug


       ext_session_acl - Squid session tracking external acl helper.

       Version 1.2


       ext_session_acl [-t timeout ] [-b database ] [-a]


       ext_session_acl  maintains a concept of sessions by monitoring requests
       and timing out sessions. The timeout is based either on idle use ( -t )
       or a fixed period of time ( -T ). The former is suitable for displaying
       terms and conditions to a user; the latter is suitable for the  display
       of  advertisments  or other notices (both as a splash page - see config
       examples in the wiki online). The session helper can also  be  used  to
       force users to re-authenticate if the %LOGIN and -a are both used.


       -t timeout  Idle  timeout for any session. The default if not specified
                   (set to 3600 seconds).

       -T timeout  Fixed timeout for any session. This will  end  the  session
                   after  the timeout regardless of a user's activity. If used
                   with active mode, this will terminate  the  user's  session
                   after timeout , after which another LOGIN will be required.
                   LOGOUT will reset the session and timeout.

       -b path     Path to persistent database. If a file  is  specified  then
                   that  single  file  is  used  as the database. If a path is
                   specified, a Berkeley DB database  environment  is  created
                   within the directory. The advantage of the latter is better
                   database support between multiple instances of the  session
                   helper. Using multiple instances of the session helper with
                   a single database file will cause synchronisation  problems
                   between  processes.   If  this  option is not specified the
                   session details  will  be  kept  in  memory  only  and  all
                   sessions  will  reset  each time Squid restarts its helpers
                   (Squid restart or rotation of logs).

       -a          Active  mode.  In  this  mode  sessions  are   started   by
                   evaluating  an  acl with the argument LOGIN , or terminated
                   by the argument LOGOUT .   Without  this  flag  the  helper
                   automatically starts the session after the first request.


       The  ext_session_acl  helper  is  a  concurrent  helper; therefore, the
       concurrency= option must be specified in the configuration.

       Passive session configuration example using the default automatic mode
              external_acl_type  session  ttl=300  negative_ttl=0   children=1
              concurrency=200 %LOGIN /usr/local/squid/libexec/ext_session_acl
              acl session external session
              http_access deny !session

       Then set  up  to  display  a
       session  startup  page and then redirect the user back to the requested
       URL given in the url query parameter.


       This  program  and  documentation  was  written  by  Henrik   Nordstrom
       <> Andrew Beverley <>


        *   Copyright   (C)   1996-2015  The  Squid  Software  Foundation  and
        * Squid software is distributed under GPLv2+ license and includes
        * contributions from numerous individuals and organizations.
        * Please see the COPYING and CONTRIBUTORS files for details.

       This program and documentation is copyright to the authors named above.

       Distributed under the GNU General Public License (GNU GPL) version 2 or
       later (GPLv2+).


       Questions  on  the usage of this program can be sent to the Squid Users
       mailing list <>


       Bug reports  need  to  be  made  in  English.   See  http://wiki.squid- for details of what you need to include
       with your bug report.

       Report bugs or bug fixes using

       Report serious security bugs to Squid Bugs <>

       Report ideas for new improvements to the Squid Developers mailing  list


       squid(8), GPL(7),
       The Squid FAQ wiki
       The Squid Configuration Manual

                                9 October 2011              ext_session_acl(8)