httpd Module
     __________________________________________________________

   Table of Contents

   1. Admin Guide

        1.1. Overview
        1.2. Overview
        1.3. Dependencies

              1.3.1. OpenSIPS Modules
              1.3.2. External Libraries or Applications

        1.4. Exported Parameters

              1.4.1. ip(string)
              1.4.2. port(integer)
              1.4.3. buf_size (integer)
              1.4.4. post_buf_size (integer)
              1.4.5. tls_cert_file (string)
              1.4.6. tls_key_file (string)
              1.4.7. tls_ciphers (string)

        1.5. Exported MI Functions

              1.5.1. httpd_list_root_path

        1.6. Exported Functions
        1.7. Known issues

   2. Developer Guide

        2.1. Available Functions

              2.1.1. register_httpdcb (module, root_path,
                      httpd_acces_handler_cb, httpd_flush_data_cb,
                      httpd_init_proc_cb)

   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 ip parameter
   1.2. Set port parameter
   1.3. Set buf_size parameter
   1.4. Set post_buf_size parameter
   1.5. Set tls_cert_file parameter
   1.6. Set tls_key_file parameter
   1.7. Set tls_key_file parameter

Chapter 1. Admin Guide

1.1. Overview

   This module provides an HTTP transport layer for OpenSIPS.

   Implementation of httpd module's http server is based on
   libmicrohttpd library.

1.2. Overview

   TLS for the http server is enabled by setting the tls_cert_file
   and tls_key_file parameters. If this is enabled, support for
   plain http is disabled.

1.3. Dependencies

1.3.1. OpenSIPS Modules

   The following modules must be loaded before this module:
     * No dependencies on other OpenSIPS modules.

1.3.2. External Libraries or Applications

   The following libraries or applications must be installed
   before running OpenSIPS with this module loaded:
     * libmicrohttpd, with EPOLL support. This typically means a
       version newer than 0.9.50.

   WARNING! Please be aware about an EPOLL support regression in
   the libmicrohttpd library and packaging which affects the
   OpenSIPS httpd module, which was fixed according to the below
   timeline. The effect of the regression is that the HTTP reply
   body is sometimes never written by the library, causing the
   client (e.g. opensips-cli) to hang indefinitely waiting for it:
     * versions 0.9.51 - 0.9.52 have been tested and work
       correctly
     * regression introduced in 0.9.53 (Apr 2017), lasting until
       0.9.71 (May 2020)
     * regression is fixed since 0.9.72 (Dec 2020)

1.4. Exported Parameters

1.4.1. ip(string)

   The IP address used by the HTTP server to listen for incoming
   requests.

   The default value is "*" (bind to all IPv6 and IPv4
   interfaces).

   Example 1.1. Set ip parameter
...
modparam("httpd", "ip", "127.0.0.1")
...

1.4.2. port(integer)

   The port number used by the HTTP server to listen for incoming
   requests.

   The default value is 8888. Ports lower than 1024 are not
   accepted.

   Example 1.2. Set port parameter
...
modparam("httpd", "port", 8000)
...

1.4.3. buf_size (integer)

   It specifies the maximum length (in bytes) of the buffer used
   to write in the html response.

   If the size of the buffer is set to zero, it will be
   automatically set to a quarter of the size of the pkg memory.

   The default value is 0.

   Example 1.3. Set buf_size parameter
...
modparam("httpd", "buf_size", 524288)
...

1.4.4. post_buf_size (integer)

   It specifies the length (in bytes) of the POST HTTP requests
   processing buffer. For large POST request, the default value
   might require to be increased.

   The default value is 1024. The minumal value is 256.

   Example 1.4. Set post_buf_size parameter
...
modparam("httpd", "post_buf_size", 4096)
...

1.4.5. tls_cert_file (string)

   Public certificate file for httpd. It will be used as
   server-side certificate for incoming TLS connections.

   The default value is ""

   Example 1.5. Set tls_cert_file parameter
...
modparam("httpd", "tls_cert_file", "/etc/opensips/tls/server.pem")
...

1.4.6. tls_key_file (string)

   Private key of the above certificate. I must be kept in a safe
   place with tight permissions!

   The default value is ""

   Example 1.6. Set tls_key_file parameter
...
modparam("httpd", "tls_key_file", "/etc/opensips/tls/server.key")
...

1.4.7. tls_ciphers (string)

   You can specify the list of algorithms for authentication and
   encryption that you allow. To obtain a list of ciphers and then
   choose, use the gnutls-cli application:
     * gnutls-cli -l

Warning

   Do not use the NULL algorithms (no encryption) ... never!!!

   The default value is
   "SECURE256:+SECURE192:-VERS-ALL:+VERS-TLS1.2"

   Example 1.7. Set tls_key_file parameter
...
modparam("httpd", "tls_ciphers", "SECURE256:+SECURE192:-VERS-ALL:+VERS-T
LS1.2")
...

1.5. Exported MI Functions

1.5.1. httpd_list_root_path

   Lists all the registered http root paths into the httpd module.
   When a request comes in, if the root parth is in the list, the
   request will be sent to the module that register it.

   Name: httpd_list_root_path

   Parameters: none

   MI FIFO Command Format:
opensips-cli -x mi httpd_list_root_path

1.6. Exported Functions

   No function exported to be used from configuration file.

1.7. Known issues

   Due to the fact that OpenSIPS is a multiprocess application,
   the microhttpd library is used in "external select" mode. This
   ensures that the library is not running in multithread mode and
   the library is entirely controled by OpenSIPS. Due to this
   particular mode of operations, for now, the entire http
   response is built in a pre-allocated buffer (see buf_size
   parameter).

   Future realeases of this module will address this issue.

   Running the http daemon as non root on ports below 1024 is
   forbidden by default in linux (kernel>=2.6.24). To allow the
   port binding, one can use setcap to give extra privilleges to
   opensips binary:
setcap 'cap_net_bind_service=+ep' /usr/local/sbin/opensips

Chapter 2. Developer Guide

2.1. Available Functions

2.1.1.  register_httpdcb (module, root_path, httpd_acces_handler_cb,
httpd_flush_data_cb, httpd_init_proc_cb)

   Register a new http root with it's associated callbacks into
   the httpd module.

   Meaning of the parameters is as follows:
     * const char *mod - name of the module that register an http
       root path to be handled;
     * str *root_path - the registered root path;
     * httpd_acces_handler_cb f1 - handler to the callback method
       to be called on root path match;
     * httpd_flush_data_cb f2 - handler to the callback method to
       be called for sending extra data (at a later time);
     * httpd_init_proc_cb f3 - handler to the callback method to
       be called during httpd process init;

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. Ovidiu Sas (@ovidiusas) 47 30 1667 147
   2. Razvan Crainea (@razvancrainea) 24 21 118 68
   3. Liviu Chircu (@liviuchircu) 21 17 138 79
   4. Bogdan-Andrei Iancu (@bogdan-iancu) 14 12 103 54
   5. Vlad Patrascu (@rvlad-patrascu) 10 7 52 89
   6. Ionut Ionita (@ionutrazvanionita) 8 6 65 21
   7. Maksym Sobolyev (@sobomax) 4 2 5 5
   8. Fabian Gast (@fgast) 4 1 150 3
   9. Stephane Alnet 3 1 39 3
   10. Stas Kobzar 3 1 2 2

   All remaining contributors: Dusan Klinec (@ph4r05), Peter
   Lemenkov (@lemenkov).

   (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.  Maksym Sobolyev (@sobomax)          Feb 2023 - Feb 2023
   2.  Liviu Chircu (@liviuchircu)         Mar 2014 - Aug 2022
   3.  Razvan Crainea (@razvancrainea)     Mar 2015 - Oct 2021
   4.  Bogdan-Andrei Iancu (@bogdan-iancu) Jan 2013 - Aug 2021
   5.  Fabian Gast (@fgast)                Aug 2020 - Aug 2020
   6.  Vlad Patrascu (@rvlad-patrascu)     May 2017 - Apr 2019
   7.  Ovidiu Sas (@ovidiusas)             Jan 2012 - Jan 2019
   8.  Peter Lemenkov (@lemenkov)          Jun 2018 - Jun 2018
   9.  Ionut Ionita (@ionutrazvanionita)   Jan 2017 - Feb 2017
   10. Dusan Klinec (@ph4r05)              Dec 2015 - Dec 2015

   All remaining contributors: Stas Kobzar, Stephane Alnet.

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

Chapter 4. Documentation

4.1. Contributors

   Last edited by: Liviu Chircu (@liviuchircu), Bogdan-Andrei
   Iancu (@bogdan-iancu), Fabian Gast (@fgast), Razvan Crainea
   (@razvancrainea), Peter Lemenkov (@lemenkov), Vlad Patrascu
   (@rvlad-patrascu), Ovidiu Sas (@ovidiusas).

   Documentation Copyrights:

   Copyright © 2012-2013 VoIP Embedded, Inc.
