maxfwd Module

Bogdan Iancu

   FhG FOKUS

Edited by

Bogdan Iancu

   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 Functions

              1.3.1. mf_process_maxfwd_header(max_value)

   2. Developer's Guide
   3. Frequently Asked Questions

   List of Examples
   1-1. mx_process_maxfwd_header usage
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Chapter 1. User's Guide

1.1. Overview

   The module implements all the operations regarding MaX-Forward
   header field, like adding it (if not present) or decrementing
   and checking the value of the existent one.
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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 Functions

1.3.1. mf_process_maxfwd_header(max_value)

   If no Max-Forward header is present in the received request, a
   header will be added having the original value equal with
   "max_value". An OK code is returned by the function.

   If a Max-Forward header is already present, its value will be
   decremented. If after this operation its value will be
   positive non-zero, an OK code will be returned. Otherwise (for
   a zero value) an error code will be returned. Note that an
   error code will be also returned if the SIP message couldn't
   be parsed or if the Max-Forward header's body invalid (non
   numerical string or negative numerical value).

   Meaning of the parameters is as follows:

     * max_value - Value to be added if there is no Max-Forwards
       header field in the message.

   Example 1-1. mx_process_maxfwd_header usage
...
# initial sanity checks -- messages with
# max_forwards==0, or excessively long requests
if (!mf_process_maxfwd_header("10")) {
    sl_send_reply("483","Too Many Hops");
    break;
};
...
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Chapter 2. Developer's Guide

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