proto_ws 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. ws_port (integer)
              1.3.2. ws_send_timeout (integer)
              1.3.3. ws_max_msg_chunks (integer)
              1.3.4. trace_destination (string)
              1.3.5. trace_on (int)
              1.3.6. trace_filter_route (string)

        1.4. Exported MI Functions

              1.4.1. ws_trace

   2. Frequently Asked Questions
   3. Contributors

        3.1. By Commit Statistics
        3.2. By Commit Activity

   4. Documentation

        4.1. Contributors

   List of Tables

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

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

   List of Examples

   1.1. Set ws_port parameter
   1.2. Set ws_send_timeout parameter
   1.3. Set ws_max_msg_chunks parameter
   1.4. Set trace_destination parameter
   1.5. Set trace_on parameter
   1.6. Set trace_filter_route parameter

Chapter 1. Admin Guide

1.1. Overview

   The WebSocket protocol (RFC 6455) provides an end-to-end
   full-duplex communication channel between two web-based
   applications. This allows WebSocket enabled browsers to connect
   to a WebSocket server and exchange any type of data. RFC 7118
   provides the specifications for transporting SIP messages over
   the WebSocket protocol.

   The proto_ws module is transport module that provides
   communication over the WebSocket protocol. This module is fully
   compliant with the RFC 7118, thus allowing browsers to act as
   SIP clients for the OpenSIPS proxy.

   The current implementation acts both as WebSocket server and
   client, thus it can accept connections from WebSocket clients
   and can also initiate connections to another WebSocket server.
   After the connection is established, messages can flow in both
   directions.

   OpenSIPS supports the following WebSocket operations:
     * text and binary - can both send and receive WebSocket
       messages that contain text or binary body
     * close - messages used to safely close the WebSocket
       communication using a 2-messages handshake
     * ping - responds with pong messages. There is no mechanism
       to trigger ping messages.
     * pong - sent when a ping message is received. OpenSIPS,
       absorbes the pong messages received.

   Once loaded, you will be able to define WebSocket listeners in
   your script. To add a listener, you have to add its IP, and
   optionally the listening port, after the mpath parameter,
   similar to this example:

...
mpath=/path/to/modules
...
socket=ws:127.0.0.1             # change with the listening IP
socket=ws:127.0.0.1:5060        # change with the listening IP and port
...

1.2. Dependencies

1.2.1. OpenSIPS Modules

   The following modules must be loaded before this module:
     * None.

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. ws_port (integer)

   The default port to be used for all WS related operation. Be
   careful as the default port impacts both the SIP listening part
   (if no port is defined in the WS listeners) and the SIP sending
   part (if the destination WS URI has no explicit port).

   If you want to change only the listening port for WS, use the
   port option in the SIP listener defintion.

   Default value is 80.

   Example 1.1. Set ws_port parameter
...
modparam("proto_ws", "ws_port", 8080)
...

1.3.2. ws_send_timeout (integer)

   Time in milliseconds after a WebSocket connection will be
   closed if it is not available for blocking writing in this
   interval (and OpenSIPS wants to send something on it).

   Default value is 100 ms.

   Example 1.2. Set ws_send_timeout parameter
...
modparam("proto_ws", "ws_send_timeout", 200)
...

1.3.3. ws_max_msg_chunks (integer)

   The maximum number of chunks in which a SIP message is expected
   to arrive via WebSocket. If a received packet is more
   fragmented than this, the connection is dropped (either the
   connection is very overloaded and this leads to high
   fragmentation - or we are the victim of an ongoing attack where
   the attacker is sending very fragmented traffic in order to
   decrease server performance).

   Default value is 4.

   Example 1.3. Set ws_max_msg_chunks parameter
...
modparam("proto_ws", "ws_max_msg_chunks", 8)
...

1.3.4. trace_destination (string)

   Trace destination as defined in the tracing module. Currently
   the only tracing module is proto_hep. Network events such as
   connect, accept and connection closed events shall be traced
   along with errors that could appear in the process. For each
   connection that is created an event containing information
   about http request and reply belonging to web socket protocol
   handshake and network layer information shall be sent.

   WARNING: A tracing module must be loaded in order for this
   parameter to work. (for example proto_hep).

   Default value is none(not defined).

   Example 1.4. Set trace_destination parameter
...
modparam("proto_hep", "trace_destination", "[hep_dest]10.0.0.2;transport
=tcp;version=3")

modparam("proto_ws", "trace_destination", "hep_dest")
...

1.3.5. trace_on (int)

   This controls whether tracing for ws is on or not. You still
   need to define trace_destinationin order to work, but this
   value will be controlled using mi function ws_trace.
   Default value is 0(tracing inactive).

   Example 1.5. Set trace_on parameter
...
modparam("proto_ws", "trace_on", 1)
...

1.3.6. trace_filter_route (string)

   Define the name of a route in which you can filter which
   connections will be trace and which connections won't be. In
   this route you will have information regarding source and
   destination ips and ports for the current connection. To
   disable tracing for a specific connection the last call in this
   route must be drop, any other exit mode resulting in tracing
   the current connection ( of course you still have to define a
   trace_destination and trace must be on at the time this
   connection is opened.

   IMPORTANT Filtering on ip addresses and ports can be made using
   $si and $sp for matching either the entity that is connecting
   to OpenSIPS or the entity to which OpenSIPS is connecting. The
   name might be misleading ( $si meaning the source ip if you
   read the docs) but in reality it is simply the socket other
   than the OpenSIPS socket. In order to match OpenSIPS interface
   (either the one that accepted the connection or the one that
   initiated a connection) $socket_in(ip) (ip) and
   $socket_in(port) (port) can be used.

   WARNING: IF trace_on is set to 0 or tracing is deactived via
   the mi command ws_trace this route won't be called.
   Default value is none(no route is set).

   Example 1.6. Set trace_filter_route parameter
...
modparam("proto_ws", "trace_filter_route", "ws_filter")
...
/* all ws connections will go through this route if tracing is activated
 * and a trace destination is defined */
route[ws_filter] {
        ...
        /* all connections opened from/by ip 1.1.1.1:8000 will be traced
           on interface 1.1.1.10:5060(opensips listener)
           all the other connections won't be */
         if ( $si == "1.1.1.1" && $sp == 8000 &&
                $socket_in(ip) == "1.1.1.10"  && $socket_in(port) == 506
0)
                exit;
        else
                drop;
}
...

1.4. Exported MI Functions

1.4.1.  ws_trace

   Name: ws_trace

   Parameters:
     * trace_mode(optional): set ws tracing on and off. This
       parameter can be missing and the command will show the
       current tracing status for this module( on or off );
       Possible values:
          + on
          + off

   MI FIFO Command Format:
                        opensips-cli -x mi ws_trace on

Chapter 2. Frequently Asked Questions

   2.1.

       Can OpenSIPS act as a WebSocket client?

       Yes, starting with OpenSIPS 2.2, it can act as a WebSocket
       client.

   2.2.

       Does OpenSIPS support WebSocket message fragmentation?

       No, WebSocket fragmentation mechanism is not supported.

Chapter 3. Contributors

3.1. By Commit Statistics

   Table 3.1. Top contributors by DevScore^(1), authored
   commits^(2) and lines added/removed^(3)
     Name DevScore Commits Lines ++ Lines --
   1. Razvan Crainea (@razvancrainea) 87 40 3991 797
   2. Ionut Ionita (@ionutrazvanionita) 21 14 609 114
   3. Bogdan-Andrei Iancu (@bogdan-iancu) 15 13 115 30
   4. Liviu Chircu (@liviuchircu) 11 8 67 93
   5. Vlad Patrascu (@rvlad-patrascu) 7 4 95 72
   6. Vlad Paiu (@vladpaiu) 4 2 3 1
   7. Peter Lemenkov (@lemenkov) 3 1 2 2
   8. Julián Moreno Patiño 3 1 1 1
   9. Maksym Sobolyev (@sobomax) 2 1 3 0

   (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

3.2. By Commit Activity

   Table 3.2. Most recently active contributors^(1) to this module
                     Name                   Commit Activity
   1. Bogdan-Andrei Iancu (@bogdan-iancu) Mar 2017 - Apr 2020
   2. Razvan Crainea (@razvancrainea)     Mar 2015 - Feb 2020
   3. Liviu Chircu (@liviuchircu)         Mar 2015 - Jan 2020
   4. Vlad Patrascu (@rvlad-patrascu)     May 2017 - Apr 2019
   5. Peter Lemenkov (@lemenkov)          Jun 2018 - Jun 2018
   6. Ionut Ionita (@ionutrazvanionita)   Jul 2015 - Apr 2017
   7. Maksym Sobolyev (@sobomax)          Feb 2017 - Feb 2017
   8. Julián Moreno Patiño                Feb 2016 - Feb 2016
   9. Vlad Paiu (@vladpaiu)               Mar 2015 - May 2015

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

Chapter 4. Documentation

4.1. Contributors

   Last edited by: Bogdan-Andrei Iancu (@bogdan-iancu), Razvan
   Crainea (@razvancrainea), Peter Lemenkov (@lemenkov), Liviu
   Chircu (@liviuchircu), Vlad Patrascu (@rvlad-patrascu), Ionut
   Ionita (@ionutrazvanionita).

   Documentation Copyrights:

   Copyright © 2015 www.opensips-solutions.com
