utils

The forward functionality allows Kamailio to configure forwarding at runtime with FIFO commands. The forwarding is executed in the pre script call back and therefore handled before the routing script is executed on the current message. The callback is not installed on default, thus this functionality has no runtime overhead when its deactivated.

1.2. Dependencies

1.2.1. Kamailio 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 Kamailio with this module loaded:

libcurl.

1.3. Exported Parameters

1.3.1. `http_query_timeout` (int)

Defines in seconds how long Kamailio waits response from HTTP server.

Default value is “4”.

Example 1.1. Set http_query_timeout parameter

...
modparam("utils", "http_query_timeout", 2)
...

1.3.2. `forward_active` (int)

Defines if the forwarding callback should be installed.

Default value is “0”.

Example 1.2. Set forward_active parameter

					...
					modparam("utils", "forward_active", 1)
					...

1.4. Exported Functions

1.4.1. `http_query(url, result)`

Sends HTTP GET request according to URL given in “url” parameter, which is a string that may contain pseudo variables.

If HTTP server returns a class 2xx or 3xx reply, first line of reply's body (if any) is stored in “result” parameter, which must be a writable pseudo variable.

Function returns reply code of HTTP reply or -1 if something went wrong.

This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE, FAILURE_ROUTE, and BRANCH_ROUTE.

Example 1.3. http_query() usage

...
http_query("http://tutpro.com/index.php?r_uri=$(ru{s.escape.param})&f_uri=$(fu{s.escape.param})",
           "$var(result)")
switch ($retcode) {
       ...
}
...

1.5. MI Commands

1.5.1. `forward_list`

List active forward rules.

No parameters.

Example 1.4. forward_list usage

...
kamctl fifo forward_list
id switch                         filter proxy
 0    off      REGISTER:INVITE:SUBSCRIBE host-a.domain-a:5060
...

1.5.2. `forward_switch`

This command can be used to activate or deactivate forwarding rules. The syntax of this configuration string is described in 1.6. (switch_setting_list).

Example 1.5. forward_switch usage

...
kamctl fifo sp_forward_switch 0=on
...

1.5.3. `forward_filter`

Can be used to specify the filter for a certain id. Messages will only be forwarded if one of the filters matches the message.

There are special filters and regular filters. Special filters are:

REQUEST (matches on every request)
REPLY (matches on every reply)

Regular filters are arbitrary strings not containing the delimiter ':'. They are matched against the request method names of the sip messages. The syntax of this configuration string is described in 1.6. (filter_setting_list).

Example 1.6. forward_filter usage

...
kamctl fifo sp_forward_filter 0=REGISTER:INVITE
...

1.5.4. `forward_proxy`

This command can be used to configure forwarding rules. Specifies the destination for a certain id. Messages will be forwarded to this destination if the preconditions hold (matching id, filter, and switch). The syntax of this configuration string is described in 1.6. (proxy_setting_list).

Example 1.7. forward_proxy usage

...
kamctl fifo sp_forward_proxy 0=host-c.domain-c:5060
...

1.6. Configuration syntax

This grammar specify the usable configuration syntax

switch_setting_list ::= switch_setting { "," switch_setting }
filter_setting_list ::= switch_setting { "," switch_setting }
proxy_setting_list ::= proxy_setting { "," proxy_setting }
switch_setting ::= id "=" switch
filter_setting ::= id "=" filter_list
proxy_setting ::= id "=" proxy
switch ::= ( "off" | "on" )
filter_list ::= filter { ":" filter }
proxy ::= host ":" port
filter ::= ( special_filter | regular_filter )
special_filter ::= ( "REQUEST" | "REPLY" )
regular_filter ::= ? [^:]* ?
host ::= char { char }
char ::= ? A-Za-z0-9.-_ ?
id ::= number
port ::= number
number ::= digit {digit}
digit ::= ? 0-9 ?

utils

Juha Heinanen

Chapter 1. Admin Guide

1.1. Overview

1.2. Dependencies

1.2.1. Kamailio Modules

1.2.2. External Libraries or Applications

1.3. Exported Parameters

1.3.1. http_query_timeout (int)

1.3.2. forward_active (int)

1.4. Exported Functions

1.4.1. http_query(url, result)

1.5. MI Commands

1.5.1. forward_list

1.5.2. forward_switch

1.5.3. forward_filter

1.5.4. forward_proxy