$Revision: 1.3 $
$Date: 2004/08/24 08:58:32 $
User's Guide
Overview
This module provides a function to answer OPTIONS requests which
are directed to the server itself. This means an OPTIONS request
which has the address of the server in the request URI, and no
username in the URI. The request will be answered with a 200 OK
which the capabilities of the server.
To answer OPTIONS request directed to your server is the easiest
way for is-alive-tests on the SIP (application) layer from remote
(similar to ICMP echo requests, also known as ping
,
on the network layer).
Dependencies
&ser; Modules
The following modules must be loaded before this module:
sl -- Stateless replies.
External Libraries or Applications
The following libraries or applications must be installed before running
&ser; with this module loaded:
None.
Exported Parameters
<varname>accept</varname> (string)
This parameter is the content of the Accept header field.
Note: it is not clearly written in RFC3261 if a proxy should
accept any content (the default */*
) because
it does not care about content. Or if it does not accept
any content, which is
.
Default value is */*
.
Set <varname>accept</varname> parameter
...
modparam("options", "accept", "application/*")
...
<varname>accept_encoding</varname> (string)
This parameter is the content of the Accept-Encoding header field.
Please do not change the default value because &ser;
does not support any encodings yet.
Default value is
.
Set <varname>accept_encoding</varname> parameter
...
modparam("options", "accept_encoding", "gzip")
...
<varname>accept_language</varname> (string)
This parameter is the content of the Accept-Language header field.
You can set any language code which you prefer for error
descriptions from other devices, but presumably there are not
much devices around which support other languages then the
default English.
Default value is en
.
Set <varname>accept_language</varname> parameter
...
modparam("options", "accept_language", "de")
...
<varname>support</varname> (string)
This parameter is the content of the Support header field.
Please do not change the default value, because &ser; currently
does not support any of the SIP extensions registered at the IANA.
Default value is
.
Set <varname>support</varname> parameter
...
modparam("options", "support", "100rel")
...
Exported Functions
<function moreinfo="none">options_reply()</function>
This function checks if the request method is OPTIONS and
if the request URI does not contain an username. If both
is true the request will be answered stateless with
200 OK
and the capabilities from the modules
parameters.
It sends 500 Server Internal Error
for some errors
and returns false if it is called for a wrong request.
The check for the request method and the missing username is
optional because it is also done by the function itself. But
you should not call this function outside the myself check
because in this case the function could answer OPTIONS requests
which are sent to you as outbound proxy but with an other
destination then your proxy (this check is currently missing
in the function).
<function>options_reply</function> usage
...
if (uri==myself) {
if ((method==OPTIONS) && (! uri=~"sip:.*[@]+.*")) {
options_reply();
}
}
...