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<section id="sl.functions" xmlns:xi="http://www.w3.org/2001/XInclude">

    <title>Functions</title>

    <section id="sl.f.sl_send_reply">
	<title>
	    <function>sl_send_reply(code, reason)</function>
	</title>
	<para>
	    For the current request, a reply is sent back having the given code
	    and text reason. The reply is sent stateless, totally independent
	    of the Transaction module and with no retransmission for the
	    INVITE's replies.
	</para>
	<para>
		If the code is in the range 300-399 (redirect reply), the current
		destination set is appended to the reply as Contact headers.
		The destination set contains the request URI (R-URI), if it is
		modified compared to the received one, plus the branches added to the
		request (e.g., after an append_branch() or lookup("location")).
		If the R-URI was changed but it is not desired to be part of the
		destination set, it can be reverted using the function revert_uri().
	</para>
	<para>
		Custom headers to the reply can be added using append_to_reply()
		function from textops module.
	</para>
	<para>Meaning of the parameters is as follows:</para>
	<itemizedlist>
	    <listitem>
		<para><emphasis>code</emphasis> - Return code.
		</para>
	    </listitem>
	    <listitem>
		<para><emphasis>reason</emphasis> - Reason phrase.
		</para>
	    </listitem>
	</itemizedlist>
	<example>
	    <title><function>sl_send_reply</function> usage</title>
	    <programlisting>
...
sl_send_reply("404", "Not found");
...
	    </programlisting>
	</example>
    </section>

	<section id="sl.f.send_reply">
		<title>
		<function moreinfo="none">send_reply(code, reason)</function>
		</title>
		<para>
		For the current request, a reply is sent back having the given code
		and text reason. The reply is sent stateful or stateless, depending of
		the <acronym>TM</acronym> module: if a transaction exists for the current
		request, then the reply is sent statefully, otherwise stateless.
		</para>
		<para>Meaning of the parameters is as follows:</para>
		<itemizedlist>
		<listitem>
			<para><emphasis>code</emphasis> - Return code.
			</para>
		</listitem>
		<listitem>
			<para><emphasis>reason</emphasis> - Reason phrase.
			</para>
		</listitem>
		</itemizedlist>
		<para>
			This function can be used from REQUEST_ROUTE and FAILURE_ROUTE.
			It can be used on ONREPLY_ROUTE executed by tm module (upon a
			t_on_reply() callback).
		</para>
		<example>
		<title><function>send_reply</function> usage</title>
		<programlisting format="linespecific">
...
send_reply("404", "Not found");
...
send_reply("403", "Invalid user - $fU");
...
</programlisting>
		</example>
	</section>

	<section id="sl.f.send_reply_mode">
		<title>
		<function moreinfo="none">send_reply_mode(code, reason, mode)</function>
		</title>
		<para>
			Similar to send_reply() function, with additional third parameter
			mode, which can specify extra operations to be done along with
			sending the SIP response.
		</para>
		<para>
			The parameter mode is a flag-based value and can be a combination of:
		</para>
		<itemizedlist>
		<listitem>
			<para><emphasis>1</emphasis> - do not connect to send the response
			(similar to set_reply_no_connect()).
			</para>
		</listitem>
		<listitem>
			<para><emphasis>2</emphasis> - close the connection after sending the
			response (similar to set_reply_close()).
			</para>
		</listitem>
		</itemizedlist>
		<example>
		<title><function>send_reply_mode</function> usage</title>
		<programlisting format="linespecific">
...
send_reply_mode("404", "Not found", "3");
...
send_reply_mode("403", "Invalid user - $fU", "3");
...
</programlisting>
		</example>
	</section>

    <section id="sl.f.sl_reply_error">
	<title>
	    <function>sl_reply_error()</function>
	</title>
	<para>
	    Sends back an error reply describing the nature of the last
	    internal error. Usually this function should be used after a
	    script function that returned an error code.
	</para>
	<example>
	    <title><function>sl_reply_error</function> usage</title>
	    <programlisting>
...
sl_reply_error();
...
	    </programlisting>
	</example>
    </section>

	<section id="sl.f.sl_forward_reply">
		<title>
		<function moreinfo="none">sl_forward_reply([ code, [ reason ] ])</function>
		</title>
		<para>
		Forward statelessly the current received SIP reply, with the option to
		change the status code and reason text. The new code has to be in the same
		class. The received reply is forwarded as well by core when the config
		execution ended, unless it is dropped from config.
		</para>
		<para>Meaning of the parameters is as follows:</para>
		<itemizedlist>
		<listitem>
			<para><emphasis>code</emphasis> - Status code.
			</para>
		</listitem>
		<listitem>
			<para><emphasis>reason</emphasis> - Reason phrase.
			</para>
		</listitem>
		</itemizedlist>
		<para>
			This function can be used from ONREPLY_ROUTE.
		</para>
		<example>
		<title><function>send_reply</function> usage</title>
		<programlisting format="linespecific">
...
if(status=="408")
    sl_forward_reply("404", "Not found");
...
</programlisting>
		</example>
	</section>

	<section id="sl.f.send_reply_error">
		<title>
		<function moreinfo="none">send_reply_error()</function>
		</title>
		<para>
		For the current request, the internal error code reply is sent back
		stateful or stateless, depending of the <acronym>TM</acronym> module:
		if a transaction exists for the current request, then the reply is sent
		statefully, otherwise stateless.
		</para>
		<para>
			It can be used from REQUEST_ROUTE, ONREPLY_ROUTE and FAILURE_ROUTE.
		</para>
		<example>
		<title><function>send_reply_error</function> usage</title>
		<programlisting format="linespecific">
...
send_reply_error();
...
</programlisting>
		</example>
	</section>

</section>
