kamailio/modules/evapi

EVAPI Module

Daniel-Constantin Mierla



Edited by

Daniel-Constantin Mierla



Copyright � 2014 asipto.com
__________________________________________________________________

Table of Contents

1. Admin Guide

1. Overview
2. Dependencies

2.1. Kamailio Modules
2.2. External Libraries or Applications

3. Parameters

3.1. workers (int)
3.2. bind_addr (str)
3.3. netstring_format (int)

4. Functions

4.1. evapi_relay(evdata)
4.2. evapi_async_relay(evdata)
4.3. evapi_close()

5. Event routes

5.1. evapi:connection-new
5.2. evapi:connection-closed
5.3. evapi:message-received

6. Exported pseudo-variables

List of Examples

1.1. Set workers parameter
1.2. Set bind_addr parameter
1.3. Set netstring_format parameter
1.4. evapi_relay usage
1.5. TCP message
1.6. evapi_async_relay usage
1.7. evapi_evapi usage

Chapter 1. Admin Guide

Table of Contents

1. Overview
2. Dependencies

2.1. Kamailio Modules
2.2. External Libraries or Applications

3. Parameters

3.1. workers (int)
3.2. bind_addr (str)
3.3. netstring_format (int)

4. Functions

4.1. evapi_relay(evdata)
4.2. evapi_async_relay(evdata)
4.3. evapi_close()

5. Event routes

5.1. evapi:connection-new
5.2. evapi:connection-closed
5.3. evapi:message-received

6. Exported pseudo-variables

1. Overview

The EVAPI module can be used to create an event message flow from
Kamailio to any application that can connect to a TCP socket. The
remote application can also issue messages received by Kamailio.

There is no protocol definition, it is all up to the author of the
routing script. Events can be generated for any event in Kamailio. For
3rd party transaction control, a transaction can be automatically
suspended when sending the event, to be resumed at a later point, maybe
triggered by an incoming message on the event socket.

2. Dependencies

2.1. Kamailio Modules
2.2. External Libraries or Applications

2.1. Kamailio Modules

The following modules must be loaded before this module:
* tm - (optional) needed only by evapi_async_relay()

2.2. External Libraries or Applications

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

3. Parameters

3.1. workers (int)
3.2. bind_addr (str)
3.3. netstring_format (int)

3.1. workers (int)

Number of worker processes to be started to handle incoming messages
from remote applications.

Default value is 1.

Example 1.1. Set workers parameter
...
modparam("evapi", "workers", 2)
...

3.2. bind_addr (str)

Local IP and port to listen on for incoming TCP connections.

Default value is "127.0.0.1:8448".

Example 1.2. Set bind_addr parameter
...
modparam("evapi", "bind_addr", "1.2.3.4:8228")
...

3.3. netstring_format (int)

Control if messages on the socket (to and from clients) are
encapsulated in netstring format.

Default value is 1 (netstring format).

Example 1.3. Set netstring_format parameter
...
modparam("evapi", "netstring_format", 0)
...

4. Functions

4.1. evapi_relay(evdata)
4.2. evapi_async_relay(evdata)
4.3. evapi_close()

4.1. evapi_relay(evdata)

Relay the event data give as parameter to connected applications. The
format on the network is netstring with evdata payload.

This function can be used from ANY_ROUTE.

Example 1.4. evapi_relay usage
...
evapi_relay("{ \"event\": \"test\",\n \"data\": { \"fU\": \"$fU\" }\n}");
...

The above exaple will send the following message over tcp:

Example 1.5. TCP message
...
47:{
"event": "test",
"data": { "fU": "test" }
},
...

4.2. evapi_async_relay(evdata)

Relay the event data give as parameter to connected applications. The
format on the network is netstring with evdata payload. Before
evaluating the parameter, the request processing is suspended using tm
module.

This function can be used from REQUEST_ROUTE.

Example 1.6. evapi_async_relay usage
...
evapi_async_relay("{ \"event\": \"suspend\",\n \"data\":"
" { \"index\": \"$T(id_index)\", \"label\": \"$T(id_label)\" }\n}");
...

4.3. evapi_close()

Close evapi current client connection.

This function can be used from ANY_ROUTE.

Example 1.7. evapi_evapi usage
...
event_route[evapi:connection-new] {
if($evapi(srcaddr)!="127.0.0.1") {
evapi_close();
exit;
}
}
...

5. Event routes

5.1. evapi:connection-new
5.2. evapi:connection-closed
5.3. evapi:message-received

5.1. evapi:connection-new

If defined, the module calls event_route[evapi:connection-new] when a
new client is connected.
...
event_route[evapi:connection-new] {
xlog("new connection from $evapi(srcaddr):$evapi(srcport)\n");
}
...

5.2. evapi:connection-closed

If defined, the module calls event_route[evapi:connection-closed] when
a client connection is closed.
...
event_route[evapi:connection-closed] {
xlog("connection closed by $evapi(srcaddr):$evapi(srcport)\n");
}
...

5.3. evapi:message-received

If defined, the module calls event_route[evapi:message-received] when a
message is received from a client.
...
event_route[evapi:message-received] {
xlog("received [$evapi(msg)] from $evapi(srcaddr):$evapi(srcport)\n");
}
...

6. Exported pseudo-variables

* $evapi(srcaddr) - source ip
* $evapi(srcport) - source port
* $evapi(msg) - received event message
* $evapi(conidx) - internal connection index

Exported pseudo-variables are documented at
http://www.kamailio.org/wiki/.