kamailio/modules/uid_domain/doc/domain_api.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE section PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" 
   "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">

<section id="domain.api" xmlns:xi="http://www.w3.org/2001/XInclude">
    <title>Internal API</title>
	<para>The domain module has an internal API which can be used to access
	additional functions of the module (i.e. functions that are normally not
	available from the routing script). Currently the API exports only the
	function <function>is_domain_local</function>. That function can be used
	to determine whether a given domain name is on the list of locally
	configured domain names.</para>

	<para>If you want to use the internal API of domain module from your
	module then you need to include the header file
	<filename>domain_api.h</filename> and call
	<function>load_domain_api</function> first.</para>
	
	<example>
		<title>Calling <function>load_domain_api</function></title>
		<programlisting>
#include "../domain/domain_api.h"

domain_api_t dom_api;

if (load_domain_api(&amp;dom_api) != 0) {
    /* error */
}
</programlisting>
	</example>

	<para>After that you can call function
	<function>is_domain_local</function> whose pointer is stored in the
	initialized data structure:</para>
	
	<programlisting>
str tmp = STR_STATIC_INIT("mydomain.com");

if (dom_api.is_domain_local(&amp;tmp) == 1) {
    /* Domain is local */
} else {
    /* Domain is not local or an error was encountered */
}
	</programlisting>
</section>