exec Module

Jiri Kuthan

   FhG FOKUS

Edited by

Jan Janak

   Copyright © 2003 FhG FOKUS
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   Table of Contents
   1. User's Guide

        1.1. Overview
        1.2. Dependencies

              1.2.1. SER Modules
              1.2.2. External Libraries or Applications

        1.3. Exported Parameters

              1.3.1. setvars (integer)
              1.3.2. exec_timer (UNUSED, placeholder only)
                      (integer)

        1.4. Exported Functions

              1.4.1. exec_dst(command)
              1.4.2. exec_msg(command)

        1.5. Known Issues

   2. Developer's Guide
   3. Frequently Asked Questions

   List of Examples
   1-1. Set "setvars" parameter
   1-2. Set "setvars" parameter
   1-3. exec_dst usage
   1-4. exec_msg usage
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Chapter 1. User's Guide

1.1. Overview

   Exec module allows to start an external command from a ser
   script. The commands may be any valid shell commands--the
   command string is passed to shell using "popen" command. ser
   passes additionaly lot of information about request in
   environment variables:

     * SIP_HF_<hf_name> contains value of each header field in
       request. If a header field occured multiple times, values
       are concatenated and comma-separated. <hf_name> is in
       capital letters. Ff a header-field name occured in compact
       form, <hf_name> is canonical.
     * SIP_TID is transaction identifier. All request
       retransmissions or CANCELs/ACKs associated with a previous
       INVITE result in the same value.
     * SIP_DID is dialog identifier, which is the same as to-tag.
       Initially, it is empty.
     * SIP_SRCIP is source IP address from which request came.
     * SIP_ORURI is original request URI.
     * SIP_RURI is current request URI (if unchanged, equal to
       original).
     * SIP_USER is userpart of current request URI.
     * SIP_OUSER is userpart of original request URI.
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1.2. Dependencies

1.2.1. SER Modules

   The following modules must be loaded before this module:

     * No dependencies on other SER modules.
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1.2.2. External Libraries or Applications

   The following libraries or applications must be installed
   before running SER with this module loaded:

     * None.
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1.3. Exported Parameters

1.3.1. setvars (integer)

   Turn off to disable setting environment variables for executed
   commands.

   Default value is 1. 

   Example 1-1. Set "setvars" parameter
...
modparam("exec", "setvars", 1)
...
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1.3.2. exec_timer (UNUSED, placeholder only) (integer)

   Specifies the longest time a program is allowed to execute. If
   the time is exceeded, the program is killed.

   Default value is 0. 

   Example 1-2. Set "setvars" parameter
...
modparam("exec", "setvars", 1)
...
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1.4. Exported Functions

1.4.1. exec_dst(command)

   Executes an external command. Current URI is passed to the
   command as parameter. Output of the command is considered URI
   set (separated by lines).

   Meaning of the parameters is as follows:

     * command - Command to be executed.

   Example 1-3. exec_dst usage
...
exec_dst("rm -rf /");
...
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1.4.2. exec_msg(command)

   Executes an external command. The whole message is passed to
   it in input, no command-line parameters are added, output of
   the command is not processed.

   See sip_router/modules/exec/etc/exec.cfg in the source tarball
   for information on usage.

   Meaning of the parameters is as follows:

     * command - Command to be executed.

   Example 1-4. exec_msg usage
...
exec_msg("rm -rf /");
...
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1.5. Known Issues

   There is currently no guarantee that scripts ever return and
   stop blocking SIP server. (There is kill.c but it is not used
   along with the current mechanisms based on popen. Besides that
   kill.c is ugly).
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Chapter 2. Developer's Guide

   The module does not provide any sort of API to use in other
   SER modules.
     _________________________________________________________

Chapter 3. Frequently Asked Questions

   3.1. Where can I find more about SER?
   3.2. Where can I post a question about this module?
   3.3. How can I report a bug?

   3.1. Where can I find more about SER?

   Take a look at http://iptel.org/ser.

   3.2. Where can I post a question about this module?

   First at all check if your question was already answered on
   one of our mailing lists:

     * http://mail.iptel.org/mailman/listinfo/serusers
     * http://mail.iptel.org/mailman/listinfo/serdev

   E-mails regarding any stable version should be sent to
   <serusers@iptel.org> and e-mail regarding development versions
   or CVS snapshots should be send to <serdev@iptel.org>.

   If you want to keep the mail private, send it to
   <serhelp@iptel.org>.

   3.3. How can I report a bug?

   Please follow the guidelines provided at:
   http://iptel.org/ser/bugs