The Ctl Module

Andrei Pelinescu-Onciul

iptelorg GmbH

Table of Contents

1. Admin Guide
1. Overview
3. Parameters
3.1. binrpc (string)
3.2. binrpc_buffer_size (integer)
3.3. mode (integer)
3.4. user (integer or string)
3.5. group (integer or string)
3.6. fifo (integer)
3.7. autoconversion (integer)
3.8. binrpc_max_body_size (integer)
3.9. binrpc_struct_max_body_size (integer)
4. RPC Functions
4.1. ctl.listen
4.2. ctl.connections
4.3. ctl.who

List of Examples

1.1. kamcmd example usage
1.2. Set binrpc parameter
1.3. Set binrpc_buffer_size parameter
1.4. Set mode parameter
1.5. Set user parameter
1.6. Set group parameter
1.7. Set fifo parameter
1.8. Set the autoconversion parameter
1.9. Set the binrpc_max_body_size parameter
1.10. Set the binrpc_struct_max_body_size parameter
1.11. print usage
1.12. ctl.connections usage
1.13. ctl.who usage

Chapter 1. Admin Guide

1. Overview

This module implements the binrpc transport interface for Kamailio RPCs. It supports various transports over which it speaks binrpc: Unix datagram sockets, Unix stream sockets, UDP and TCP. It also supports a backward compatible FIFO interface (using the old Kamailio FIFO protocol).

By default (if no parameters are changed in the config file) it uses a Unix stream socket under /run/kamailio: /run/kamailio/kamailio_ctl. This socket is also the default for kamcmd.

In general it's used in conjunction with kamcmd. kamcmd is a Unix tool for invoking Kamailio RPC functions. It can be used both in interactive mode (supports tab-completion and history) or command line mode.

Example 1.1. kamcmd example usage

$ kamcmd ps
11262	attendant
11268	udp receiver child=0 sock=
11269	udp receiver child=1 sock=
11270	udp receiver child=0 sock=
11271	udp receiver child=1 sock=
11272	slow timer
11273	timer
11274	ctl handler
11275	tcp receiver child=0
11276	tcp receiver child=1
11277	tcp main process

See utils/kamcmd/EXAMPLES for more examples.


binrpc is a Kamailio proprietary binary protocol for invoking rpcs. It was designed such that it would minimize the packet sizes and it would be very fast to parse (as opposed to XML-rpc).

The binrpc encoding format is fully documented inside modules/ctl/binrpc.h.

3. Parameters

3.1. binrpc (string)

Specifies the transport used for the binrpc protocol. The following transport protocol are supported: Unix datagram sockets, Unix stream sockets, UDP and TCP.

The format is: [ protocol:] address_port|path .

  • For Unix sockets: [unixd|unixs|unix]:path where "unixd" means Unix datagram sockets and "unix" "unixs" mean Unix stream sockets. Examples: "unixd:/tmp/unix_dgram", "unixs:/tmp/unix_stream", "unix:/tmp/unix_stream".

  • For UDP or TCP sockets: [udp|tcp]:address:port. If the address is "*" or missing, it will bind to all the local addresses ( Examples: "udp:localhost:2046", "tcp:localhost:2046", "tcp:3012", "udp:*:3012".

If the protocol part is missing and the address/path part looks like a file system path it will default to a Unix stream socket and if not to a Unix UDP socket. Examples:

  • "/tmp/unix_test" - equivalent to "unixs:/tmp/unix_test".
  • "localhost:3000" - equivalent to "udp:localhost:3000".

Multiple transports / listen addresses can be specified, just by setting the parameter multiple times.

Default: "unix:/run/kamailio/kamailio_ctl" (Unix stream socket). The default value is used only if no binrpc parameter is found in the config file.

Example 1.2. Set binrpc parameter

loadmodule "ctl"
# optional listen addresses, if no one is specified,
# ctl will listen on unixs:/tmp/kamailio_ctl

modparam("ctl", "binrpc", "unix:/run/kamailio/kamailio_ctl") # default
modparam("ctl", "binrpc", "udp:localhost:2046")
modparam("ctl", "binrpc", "tcp:localhost:2046")
modparam("ctl", "binrpc", "unixd:/tmp/unix_dgram")  # unix datagram
modparam("ctl", "binrpc", "unixs:/tmp/unix_stream") # unix stream
modparam("ctl", "binrpc", "unix:/tmp/unix_default") # unix stream
modparam("ctl", "binrpc", "/tmp/unix_test")         # unix stream
modparam("ctl", "binrpc", "localhost:3000")         # udp
modparam("ctl", "binrpc", "tcp:3012")               # tcp any , port 3012
modparam("ctl", "binrpc", "udp:*:3012")             # udp any , port 3012

3.2. binrpc_buffer_size (integer)

The size of the internal buffer used for printing elements of the RPC response (e.g., internal RPC printf()). The value is given in bytes.

Default: 1024.

Example 1.3. Set binrpc_buffer_size parameter

            modparam("ctl", "binrpc_buffer_size", 4096)

3.3. mode (integer)

Permissions used for the created Unix sockets or for the fifo.

Default: 0600.

Example 1.4. Set mode parameter

modparam("ctl", "mode", 0600) # permissions

3.4. user (integer or string)

Username or uid used for the created Unix sockets or for the fifo.

Default: not set (the user under which SER runs).

Example 1.5. Set user parameter

modparam("ctl", "user", "andrei")

3.5. group (integer or string)

Group name or gid used for the created Unix sockets or for the fifo.

Default: not set (the group under which SER runs).

Example 1.6. Set group parameter

modparam("ctl", "group", 100)

3.6. fifo (integer)

fifo used for the obsolete fifo protocol. The fifo protocol can be run over a real fifo, over UDP or over TCP. Format: [protocol:]path|address. If no protocol is specified the default is "fifo". Examples: "fifo:/tmp/kamailio_fifo", "/tmp/kamailio_fifo2", "udp:*:2050", "tcp:localhost:2050". For more details on the UDP and TCP formats see binrpc. Multiple fifos or fifo transports can be used in the same time (just by setting the fifo parameter multiple times in the config).

Default: not set (no fifo will be used).

Example 1.7. Set fifo parameter

# old fifo support
modparam("ctl", "fifo", "fifo:/tmp/kamailio_fifo")      # classic fifo
modparam("ctl", "fifo", "/tmp/kamailio_fifo2")
modparam("ctl", "fifo", "udp:*:2050")              # fifo protocol over udp
modparam("ctl", "fifo", "tcp:*:2050")              # fifo over tcp

3.7. autoconversion (integer)

Enable or disable automatic type conversion globally, for all the methods parameters. If on, a type mismatch in a method parameter will not cause a fault if it is possible to automatically convert it to the expected type.

Default: off

It is recommended to leave this parameter to its default off value and fix instead the client application (which should use the proper types) or to modify the target rpc to accept any type (see the rpc scan '.' modifier).

Example 1.8. Set the autoconversion parameter

modparam("ctl", "autoconversion", 1)

3.8. binrpc_max_body_size (integer)

Set the size of binrpc buffer for RPC reply. Value represents kilobytes.

Default: 32 (meaning 32KB);

Example 1.9. Set the binrpc_max_body_size parameter

modparam("ctl", "binrpc_max_body_size", 16)

3.9. binrpc_struct_max_body_size (integer)

Set the size of binrpc structure buffer for RPC reply. Value represents kilobytes.

Default: 8 (meaning 8KB);

Example 1.10. Set the binrpc_struct_max_body_size parameter

modparam("ctl", "binrpc_struct_max_body_size", 4)

4. RPC Functions

4.1.  ctl.listen

List all the sockets on which the ctl module listens.

Example 1.11. print usage

 $ kamcmd -f"[%v] %v:%v %v\n" ctl.listen
[binrpc] unix_stream:/run/kamailio/kamailio_ctl

# note: the above command is equivalent with kamcmd listen

4.2.  ctl.connections

Returns the number of open binrpc connections (to the ctl module).

Example 1.12. ctl.connections usage

 $ kamcmd ctl.connections

4.3.  ctl.who

List open binrpc connections (to the ctl module).

Example 1.13. ctl.who usage

 $ kamcmd -f"[%v] %v: %v %v -> %v %v\n" ctl.who
[binrpc] unix_stream: <anonymous unix socket>  -> /run/kamailio/kamailio_ctl

# note the above command is equivalent to kamcmd who