HTTPD module
Admin Guide
Section titled “Admin Guide”Overview
Section titled “Overview”This module provides an HTTP transport layer for OpenSIPS.
Implementation of httpd module’s http server is based on libmicrohttpd library.
Overview
Section titled “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.
Dependencies
Section titled “Dependencies”OpenSIPS Modules
Section titled “OpenSIPS Modules”The following modules must be loaded before this module:
- No dependencies on other OpenSIPS modules.
External Libraries or Applications
Section titled “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)
Exported Parameters
Section titled “Exported Parameters”ip(string)
Section titled “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).
...modparam("httpd", "ip", "127.0.0.1")...port(integer)
Section titled “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.
...modparam("httpd", "port", 8000)...buf_size (integer)
Section titled “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.
...modparam("httpd", "buf_size", 524288)...post_buf_size (integer)
Section titled “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.
...modparam("httpd", "post_buf_size", 4096)...tls_cert_file (string)
Section titled “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 ""
...modparam("httpd", "tls_cert_file", "/etc/opensips/tls/server.pem")...tls_key_file (string)
Section titled “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 ""
...modparam("httpd", "tls_key_file", "/etc/opensips/tls/server.key")...tls_ciphers (string)
Section titled “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
The default value is “SECURE256:+SECURE192:-VERS-ALL:+VERS-TLS1.2”
...modparam("httpd", "tls_ciphers", "SECURE256:+SECURE192:-VERS-ALL:+VERS-TLS1.2")...Exported MI Functions
Section titled “Exported MI Functions”httpd_list_root_path
Section titled “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_pathExported Functions
Section titled “Exported Functions”No function exported to be used from configuration file.
Known Issues
Section titled “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/opensipsDeveloper Guide
Section titled “Developer Guide”Available Functions
Section titled “Available Functions”register_httpdcb (module, root_path, httpd_acces_handler_cb, httpd_flush_data_cb, httpd_init_proc_cb)
Section titled “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;
Contributors
Section titled “Contributors”By Commit Statistics
Section titled “By Commit Statistics”Top contributors by DevScore(1), authored commits(2) and lines added/removed(3)
| # | Name | DevScore | Commits | Lines++ | Lines— |
|---|---|---|---|---|---|
| 1. | Ovidiu Sas (@ovidiusas) | 49 | 30 | 1706 | 186 |
| 2. | Razvan Crainea (@razvancrainea) | 26 | 22 | 125 | 75 |
| 3. | Liviu Chircu (@liviuchircu) | 21 | 17 | 142 | 83 |
| 4. | Bogdan-Andrei Iancu (@bogdan-iancu) | 15 | 12 | 113 | 64 |
| 5. | Vlad Patrascu (@rvlad-patrascu) | 10 | 7 | 52 | 89 |
| 6. | Ionut Ionita (@ionutrazvanionita) | 8 | 6 | 65 | 21 |
| 7. | Stefan Darius (@dariusstefan) | 8 | 4 | 331 | 42 |
| 8. | Maksym Sobolyev (@sobomax) | 4 | 2 | 5 | 5 |
| 9. | Fabian Gast (@fgast) | 4 | 1 | 154 | 7 |
| 10. | Stephane Alnet | 3 | 1 | 52 | 16 |
All remaining contributors: Stas Kobzar, Peter Lemenkov (@lemenkov), Dusan Klinec (@ph4r05).
(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
(3) ignoring whitespace edits, renamed files and auto-generated files
By Commit Activity
Section titled “By Commit Activity”| # | Name | Commit Activity |
|---|---|---|
| 1. | Stefan Darius (@dariusstefan) | Jun 2026 - Jul 2026 |
| 2. | Razvan Crainea (@razvancrainea) | Mar 2015 - Jun 2026 |
| 3. | Maksym Sobolyev (@sobomax) | Feb 2023 - Feb 2023 |
| 4. | Liviu Chircu (@liviuchircu) | Mar 2014 - Aug 2022 |
| 5. | Bogdan-Andrei Iancu (@bogdan-iancu) | Jan 2013 - Aug 2021 |
| 6. | Fabian Gast (@fgast) | Aug 2020 - Aug 2020 |
| 7. | Vlad Patrascu (@rvlad-patrascu) | May 2017 - Apr 2019 |
| 8. | Ovidiu Sas (@ovidiusas) | Jan 2012 - Jan 2019 |
| 9. | Peter Lemenkov (@lemenkov) | Jun 2018 - Jun 2018 |
| 10. | Ionut Ionita (@ionutrazvanionita) | Jan 2017 - Feb 2017 |
All remaining contributors: Dusan Klinec (@ph4r05), Stas Kobzar, Stephane Alnet.
(1) including any documentation-related commits, excluding merge commits
Documentation
Section titled “Documentation”Contributors
Section titled “Contributors”Last edited by: Razvan Crainea (@razvancrainea), Liviu Chircu (@liviuchircu), Bogdan-Andrei Iancu (@bogdan-iancu), Fabian Gast (@fgast), Peter Lemenkov (@lemenkov), Vlad Patrascu (@rvlad-patrascu), Ovidiu Sas (@ovidiusas).
License
Section titled “License”All documentation files (i.e. .md extension) are licensed under the Creative Common License 4.0