Daniel-Constantin Mierla

Edited by

Daniel-Constantin Mierla

Table of Contents

1. Admin Guide
1. Overview
1.1. Limitations
2. Dependencies
2.1. Kamailio Modules
2.2. External Libraries or Applications
3. Parameters
3.1. pretty_format (int)
3.2. transport (int)
3.3. fifo_name (str)
3.4. fifo_mode (int)
3.5. fifo_group (int or str)
3.6. fifo_user (int or str)
3.7. fifo_reply_dir (str)
4. Functions
4.1. jsonrpc_dispatch()
4.2. jsonrpc_exec(cmd)
5. JSONRPC Transports

List of Examples

1.1. Set pretty_format parameter
1.2. Set transport parameter
1.3. Set fifo_name parameter
1.4. Set fifo_mode parameter
1.5. Set fifo_group parameter
1.6. Set fifo_user parameter
1.7. Set fifo_reply_dir parameter
1.8. jsonrpc_dispatch usage
1.9. jsonrpc_exec usage
1.10. JSONRPC Over Fifo Command
1.11. JSONRPC Over Fifo Command From Termina

Chapter 1. Admin Guide

1. Overview

This module provides a JSON-RPC v2 server over HTTP implementation, tailored for the needs of Kamailio. It implements the Kamailio RPC interface over JSON-RPC.

The specification for JSON-RPC is available at: http://www.jsonrpc.org/specification.

The JSONRPC-S module uses the xHTTP module to handle HTTP/S requests. Read the documentation of the xHTTP module for more details.

1.1. Limitations

  • This module does not implement asynchronous RPC commands. It is unlikely that asynchronous RPC commands will be executed from an JSON-RPC over HTTP client.

  • This module does not accept parameters embedded in a structure (see the RPC documentation for more info about how parameters can be passed to RPC).

2. Dependencies

2.1. Kamailio Modules

The following modules must be loaded before this module:

  • xhttp - xHTTP.

2.2. External Libraries or Applications

The following libraries or applications must be installed before running Kamailio with this module loaded:

  • None

3. Parameters

3.1. pretty_format (int)

Pretty format for JSON-RPC response document.

Default value is '0'.

Example 1.1. Set pretty_format parameter

modparam("jsonrpc-s", "pretty_format", 1)

3.2. transport (int)

Control what transports are enabled. The value can be:

  • 0 - all transports that can be enabled. For http, the xhttp module must be loaded. For FIFO, the fifo_name parameter must be set.

  • 1 - only HTTP transport

  • 2 - only FIFO transport

Default value is '0'.

Example 1.2. Set transport parameter

modparam("jsonrpc-s", "transport", 1)

3.3. fifo_name (str)

The name of the FIFO file to be created for listening and reading external commands. If the given path is not absolute, the fifo file is created relative to run_dir (global parameter).

Default value is NONE.

Example 1.3. Set fifo_name parameter

modparam("jsonrpc-s", "fifo_name", "/tmp/kamailio_jsonrpc_fifo")

3.4. fifo_mode (int)

Permission to be used for creating the listening FIFO file. It follows the UNIX conventions.

Default value is 0660 (rw-rw----).

Example 1.4. Set fifo_mode parameter

modparam("jsonrpc-s", "fifo_mode", 0600)

3.5. fifo_group (int or str)

System Group to be used for creating the listening FIFO file.

Default value is the inherited one (process group).

Example 1.5. Set fifo_group parameter

modparam("jsonrpc-s", "fifo_group", 0)
modparam("jsonrpc-s", "fifo_group", "root")

3.6. fifo_user (int or str)

System User to be used for creating the listening FIFO file.

Default value is the inherited one (process user).

Example 1.6. Set fifo_user parameter

modparam("jsonrpc-s", "fifo_user", 0)
modparam("jsonrpc-s", "fifo_user", "root")

3.7. fifo_reply_dir (str)

Directory to be used for creating the reply FIFO files.

Default value is /tmp/

Example 1.7. Set fifo_reply_dir parameter

modparam("jsonrpc-s", "fifo_reply_dir", "/home/kamailio/tmp/")

4. Functions

4.1.  jsonrpc_dispatch()

Handle the JSONRPC request and generate a response.

Example 1.8. jsonrpc_dispatch usage







loadmodule "sl.so"
loadmodule "pv.so"
loadmodule "xhttp.so"
loadmodule "jsonrpc-s.so"

request_route {
	send_reply("404", "not found");

event_route[xhttp:request] {
    if(src_ip!= {
        xhttp_reply("403", "Forbidden", "text/html",
            "<html><body>Not allowed from $si</body></html>");
	if ($hu =~ "^/RPC") {
	} else {
        xhttp_reply("200", "OK", "text/html",
            "<html><body>Wrong URL $hu</body></html>");

4.2.  jsonrpc_exec(cmd)

Execute a JSON-RPC command given as a parameter.

The parameter has to be a valid full JSON-RPC document. It can be a dynamic string with variables. The result of the command can be accessed via $jsonrpl(key) pseudo variables.

Example 1.9. jsonrpc_exec usage

jsonrpc_exec({"jsonrpc": "2.0", "method": "dispatcher.reload", "id": 1}');

5. JSONRPC Transports

JSONRPC specifications do not enforce a specific transport to carry the JSON documents. Very common is JSONRPC over HTTP or HTTPS, and they are supported by Kamailio. In addition, Kamailio supports receiving JSON documents via a local FIFO file.


It requires that XHTTP module is loaded. HTTPS can be used if you enable TLS for Kamailio. The JSONRPC requests have to be sent to the TCP or TLS ports of Kamailio.

The 'transport' parameter has to be 0 or 1.

The format of the JSON document must follow the JSONRPC specifications.


This module can retrive JSONRPC requests via a local FIFO file. To enable this feature, 'fifo_name' parameter must be set and 'transport' parameter has to be 0 or 2.

The format of the JSON document must follow the JSONRPC specifications plus an additional field named 'reply_name'. The value for this field must be the name of the FIFO file were to write the JSONRPC response. The reply FIFO file is created in the folder specified by 'fifo_reply_dir'. Next is an example showing a JSONRPC command to be sent via FIFO transport.

Example 1.10. JSONRPC Over Fifo Command

 "jsonrpc": "2.0",
  "method": "core.psx",
  "reply_name": "kamailio_jsonrpc_reply_fifo",
  "id": 1

Next is an example of how to test it from a terminal, assuming that the parameter 'fifo_name' is set to '/tmp/kamailio_jsonrpc_fifo'.

Example 1.11. JSONRPC Over Fifo Command From Termina

mkfifo /tmp/kamailio_jsonrpc_reply_fifo
cat /tmp/kamailio_jsonrpc_reply_fifo &
echo '{"jsonrpc": "2.0", "method": "core.psx", \
          "reply_name": "kamailio_jsonrpc_reply_fifo", "id": 1}' \
     > /tmp/kamailio_jsonrpc_fifo
rm /tmp/kamailio_jsonrpc_reply_fifo