Options Module
     __________________________________________________________

   Table of Contents

   1. Admin Guide

        1.1. Overview
        1.2. Dependencies

              1.2.1. OpenSIPS Modules
              1.2.2. External Libraries or Applications

        1.3. Exported Parameters

              1.3.1. accept (string)
              1.3.2. accept_encoding (string)
              1.3.3. accept_language (string)
              1.3.4. support (string)

        1.4. Exported Functions

              1.4.1. options_reply()

   2. Contributors

        2.1. By Commit Statistics
        2.2. By Commit Activity

   3. Documentation

        3.1. Contributors

   List of Tables

   2.1. Top contributors by DevScore^(1), authored commits^(2) and
          lines added/removed^(3)

   2.2. Most recently active contributors^(1) to this module

   List of Examples

   1.1. Set accept parameter
   1.2. Set accept_encoding parameter
   1.3. Set accept_language parameter
   1.4. Set support parameter
   1.5. options_reply usage

Chapter 1. Admin Guide

1.1. Overview

   This module provides a function to answer OPTIONS requests
   which are directed to the server itself. This means an OPTIONS
   request which has the address of the server in the request URI,
   and no username in the URI. The request will be answered with a
   200 OK which the capabilities of the server.

   To answer OPTIONS request directed to your server is the
   easiest way for is-alive-tests on the SIP (application) layer
   from remote (similar to ICMP echo requests, also known as
   “ping”, on the network layer).

1.2. Dependencies

1.2.1. OpenSIPS Modules

   The following modules must be loaded before this module:
     * sl -- Stateless replies.
     * signaling -- Stateless replies.

1.2.2. External Libraries or Applications

   The following libraries or applications must be installed
   before running OpenSIPS with this module loaded:
     * None.

1.3. Exported Parameters

1.3.1. accept (string)

   This parameter is the content of the Accept header field. If
   “”, the header is not added in the reply. Note: it is not
   clearly written in RFC3261 if a proxy should accept any content
   (the default “*/*”) because it does not care about content. Or
   if it does not accept any content, which is “”.

   Default value is “*/*”.

   Example 1.1. Set accept parameter
...
modparam("options", "accept", "application/*")
...

1.3.2. accept_encoding (string)

   This parameter is the content of the Accept-Encoding header
   field. If “”, the header is not added in the reply. Please do
   not change the default value because OpenSIPS does not support
   any encodings yet.

   Default value is “”.

   Example 1.2. Set accept_encoding parameter
...
modparam("options", "accept_encoding", "gzip")
...

1.3.3. accept_language (string)

   This parameter is the content of the Accept-Language header
   field. If “”, the header is not added in the reply. You can set
   any language code which you prefer for error descriptions from
   other devices, but presumably there are not much devices around
   which support other languages then the default English.

   Default value is “en”.

   Example 1.3. Set accept_language parameter
...
modparam("options", "accept_language", "de")
...

1.3.4. support (string)

   This parameter is the content of the Support header field. If
   “”, the header is not added in the reply. Please do not change
   the default value, because OpenSIPS currently does not support
   any of the SIP extensions registered at the IANA.

   Default value is “”.

   Example 1.4. Set support parameter
...
modparam("options", "support", "100rel")
...

1.4. Exported Functions

1.4.1.  options_reply()

   This function checks if the request method is OPTIONS and if
   the request URI does not contain an username. If both is true
   the request will be answered stateless with “200 OK” and the
   capabilities from the modules parameters.

   It sends “500 Server Internal Error” for some errors and
   returns false if it is called for a wrong request.

   The check for the request method and the missing username is
   optional because it is also done by the function itself. But
   you should not call this function outside the myself check
   because in this case the function could answer OPTIONS requests
   which are sent to you as outbound proxy but with an other
   destination then your proxy (this check is currently missing in
   the function).

   This function can be used from REQUEST_ROUTE.

   Example 1.5. options_reply usage
...
if (is_myself("$rd")) {
        if (is_method("OPTIONS") && (! $ru=~"sip:.*[@]+.*")) {
                options_reply();
        }
}
...

Chapter 2. Contributors

2.1. By Commit Statistics

   Table 2.1. Top contributors by DevScore^(1), authored
   commits^(2) and lines added/removed^(3)
     Name DevScore Commits Lines ++ Lines --
   1. Bogdan-Andrei Iancu (@bogdan-iancu) 20 18 52 35
   2. Daniel-Constantin Mierla (@miconda) 14 12 41 31
   3. Liviu Chircu (@liviuchircu) 9 7 29 43
   4. Nils Ohlmeier 9 3 630 4
   5. Vlad Patrascu (@rvlad-patrascu) 5 3 9 6
   6. Razvan Crainea (@razvancrainea) 5 2 82 87
   7. Elena-Ramona Modroiu 4 2 4 4
   8. Ancuta Onofrei 3 1 10 11
   9. Jan Janak (@janakj) 3 1 7 7
   10. Konstantin Bokarius 3 1 2 5

   All remaining contributors: Peter Lemenkov (@lemenkov), Edson
   Gellert Schubert.

   (1) DevScore = author_commits + author_lines_added /
   (project_lines_added / project_commits) + author_lines_deleted
   / (project_lines_deleted / project_commits)

   (2) including any documentation-related commits, excluding
   merge commits. Regarding imported patches/code, we do our best
   to count the work on behalf of the proper owner, as per the
   "fix_authors" and "mod_renames" arrays in
   opensips/doc/build-contrib.sh. If you identify any
   patches/commits which do not get properly attributed to you,
   please submit a pull request which extends "fix_authors" and/or
   "mod_renames".

   (3) ignoring whitespace edits, renamed files and auto-generated
   files

2.2. By Commit Activity

   Table 2.2. Most recently active contributors^(1) to this module
                      Name                   Commit Activity
   1.  Bogdan-Andrei Iancu (@bogdan-iancu) Nov 2003 - Apr 2019
   2.  Vlad Patrascu (@rvlad-patrascu)     May 2017 - Apr 2019
   3.  Peter Lemenkov (@lemenkov)          Jun 2018 - Jun 2018
   4.  Liviu Chircu (@liviuchircu)         Jul 2014 - Jun 2018
   5.  Razvan Crainea (@razvancrainea)     Nov 2012 - Aug 2015
   6.  Daniel-Constantin Mierla (@miconda) Jul 2006 - Mar 2008
   7.  Konstantin Bokarius                 Mar 2008 - Mar 2008
   8.  Edson Gellert Schubert              Feb 2008 - Feb 2008
   9.  Ancuta Onofrei                      Sep 2007 - Sep 2007
   10. Elena-Ramona Modroiu                Jul 2005 - Oct 2005

   All remaining contributors: Jan Janak (@janakj), Nils Ohlmeier.

   (1) including any documentation-related commits, excluding
   merge commits

Chapter 3. Documentation

3.1. Contributors

   Last edited by: Bogdan-Andrei Iancu (@bogdan-iancu), Peter
   Lemenkov (@lemenkov), Liviu Chircu (@liviuchircu), Vlad
   Patrascu (@rvlad-patrascu), Razvan Crainea (@razvancrainea),
   Daniel-Constantin Mierla (@miconda), Konstantin Bokarius, Edson
   Gellert Schubert, Elena-Ramona Modroiu, Jan Janak (@janakj),
   Nils Ohlmeier.

   Documentation Copyrights:

   Copyright © 2003 FhG FOKUS
