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<!-- Module User's Guide -->

<chapter>

	<title>&adminguide;</title>


	<section>
		<title>Overview</title>
		<para>cpl-c modules implements a CPL (Call Processing Language)
		interpreter. Support for uploading/downloading/removing scripts via
		SIP REGISTER method is present.
		</para>
		<para>
		CPL is an IETF specification detailed in RFC3880
		(https://tools.ietf.org/html/rfc3880).
		</para>
	</section>
	<section>
		<title>Dependencies</title>
		<section>
			<title>&kamailio; Modules</title>
			<para>
			The following modules must be loaded before this module:
			<itemizedlist>
			<listitem>
			<para>
				<emphasis>any DB module- a DB module for interfacing the DB
				operations (modules like mysql, postgres, dbtext, etc)
				</emphasis>
			</para>
			</listitem>
			<listitem>
			<para>
				<emphasis>TM (Transaction) module- used for proxying/forking
				requests
				</emphasis>
			</para>
			</listitem>
			<listitem>
			<para>
				<emphasis>SL (StateLess) module - used for sending stateless
				reply when responding to REGISTER request or for sending back
				error responses
				</emphasis>
			</para>
			</listitem>
			<listitem>
			<para>
				<emphasis>USRLOC (User Location) module - used for implementing
				lookup("registration") tag (adding into location set of the
				users' contact)
				</emphasis>
			</para>
			</listitem>
			</itemizedlist>
			</para>
		</section>
		<section>
			<title>External Libraries or Applications</title>
			<para>
				The following libraries or applications must be installed
				before running &kamailio; with this module loaded:
				<itemizedlist>
				<listitem>
				<para>
					<emphasis>libxml2 and libxml2-devel - on some SO, these to
					packages are merged into libxml2. This library contains an
					engine for XML parsing, DTD validation and
					DOM manipulation.
					</emphasis>
				</para>
				</listitem>
				</itemizedlist>
			</para>
		</section>
	</section>


	<section>
		<title>Parameters</title>
		<section id="cplc.p.db_url">
			<title><varname>db_url</varname> (string)</title>
			<para>
				A SQL URL have to be given to the module for knowing where the
				database containing the table with CPL scripts is locates. If
				required a user name and password can be specified for allowing
				the module to connect to the database server.
			</para>
			<para>
			<emphasis>
				Default value is <quote>&defaultdb;</quote>.
			</emphasis>
			</para>
			<example>
				<title>Set <varname>db_url</varname> parameter</title>
				<programlisting format="linespecific">
...
modparam("cpl-c","db_url","&exampledb;")
...
</programlisting>
			</example>
		</section>
		<section id="cplc.p.db_table">
			<title><varname>db_table</varname> (string)</title>
			<para>
				Indicates the name of the table that store the CPL scripts.
				This table must be locate into the database specified by
				<quote>db_url</quote> parameter. For more about the format of the CPL
				table please see the modules/cpl-c/init.mysql file.
			</para>
			<para>
			<emphasis>
				Default value is <quote>cpl</quote>.
			</emphasis>
			</para>
			<example>
				<title>Set <varname>db_table</varname> parameter</title>
				<programlisting format="linespecific">
...
modparam("cpl-c","cpl_table","cpl")
...
</programlisting>
			</example>
		</section>
		<section id="cplc.p.username_column">
			<title><varname>username_column</varname> (string)</title>
			<para>
				Indicates the name of the column used for storing the username.
			</para>
			<para>
				<emphasis>
					Default value is <quote>username</quote>.
				</emphasis>
			</para>
			<example>
				<title>Set <varname>username_column</varname> parameter</title>
				<programlisting format="linespecific">
...
modparam("cpl-c","username_column","username")
...
</programlisting>
			</example>
		</section>
		<section id="cplc.p.domain_column">
			<title><varname>domain_column</varname> (string)</title>
			<para>
				Indicates the name of the column used for storing the domain.
			</para>
			<para>
				<emphasis>
					Default value is <quote>domain</quote>.
				</emphasis>
			</para>
			<example>
				<title>Set <varname>domain_column</varname> parameter</title>
				<programlisting format="linespecific">
...
modparam("cpl-c","domain_column","domain")
...
</programlisting>
			</example>
		</section>
		<section id="cplc.p.xml_column">
			<title><varname>cpl_xml_column</varname> (string)</title>
			<para>
				Indicates the name of the column used for storing the
				XML version of the cpl script.
			</para>
			<para>
				<emphasis>
					Default value is <quote>cpl_xml</quote>.
				</emphasis>
			</para>
			<example>
				<title>Set <varname>cpl_xml_column</varname> parameter</title>
				<programlisting format="linespecific">
...
modparam("cpl-c","cpl_xml_column","cpl_xml")
...
</programlisting>
			</example>
		</section>
		<section id="cplc.p.bin_column">
			<title><varname>cpl_bin_column</varname> (string)</title>
			<para>
				Indicates the name of the column used for storing the
				binary version of the cpl script (compiled version).
			</para>
			<para>
				<emphasis>
					Default value is <quote>cpl_bin</quote>.
				</emphasis>
			</para>
			<example>
				<title>Set <varname>cpl_bin_column</varname> parameter</title>
				<programlisting format="linespecific">
...
modparam("cpl-c","cpl_bin_column","cpl_bin")
...
</programlisting>
			</example>
		</section>
		<section id="cplc.p.dtd_file">
			<title><varname>cpl_dtd_file</varname> (string)</title>
			<para>
				Points to the DTD file describing the CPL grammar. The file
				name may include also the path to the file. This path can be
				absolute or relative (be careful the path will be relative
				to the starting directory of &kamailio;).
			</para>
			<para>
				<emphasis>
					This parameter is MANDATORY!
				</emphasis>
			</para>
			<example>
				<title>Set <varname>cpl_dtd_file</varname> parameter</title>
				<programlisting format="linespecific">
...
modparam("cpl-c","cpl_dtd_file","/etc/kamailio/cpl-06.dtd")
...
</programlisting>
			</example>
		</section>
		<section id="cplc.p.log_dir">
			<title><varname>log_dir</varname> (string)</title>
			<para>
				Points to a directory where should be created all the log file
				generated by the LOG CPL node. A log file per user will be
				created (on demand) having the name username.log.
			</para>
			<para>
				<emphasis>
					If this parameter is absent, the logging will be disabled
					without generating error on execution.
				</emphasis>
			</para>
			<example>
				<title>Set <varname>log_dir</varname> parameter</title>
				<programlisting format="linespecific">
...
modparam("cpl-c","log_dir","/var/log/kamailio/cpl")
...
</programlisting>
			</example>
		</section>
		<section id="cplc.p.proxy_recurse">
			<title><varname>proxy_recurse</varname> (int)</title>
			<para>
				Tells for how many time is allow to have recurse for PROXY CPL
				node If it has value 2, when doing proxy, only twice the proxy
				action will be re-triggered by  a redirect response; the third
				time, the proxy execution will end by going on REDIRECTION
				branch. The recurse feature can be disable by setting this
				parameter to 0
			</para>
			<para>
				<emphasis>
					Default value of this parameter is 0.
				</emphasis>
			</para>
			<example>
				<title>Set <varname>proxy_recurse</varname> parameter</title>
				<programlisting format="linespecific">
...
modparam("cpl-c","proxy_recurse",2)
...
</programlisting>
			</example>
		</section>
		<section id="cplc.p.proxy_route">
			<title><varname>proxy_route</varname> (string)</title>
			<para>
				Before doing proxy (forward), a script route can be executed.
				All modifications made by that route will be reflected only for
				the current branch.
			</para>
			<para>
				<emphasis>
					Default value of this parameter is NULL (none).
				</emphasis>
			</para>
			<example>
				<title>Set <varname>proxy_route</varname> parameter</title>
				<programlisting format="linespecific">
...
modparam("cpl-c","proxy_route","1")
...
</programlisting>
			</example>
		</section>
		<section id="cplc.p.case_sensitive">
			<title><varname>case_sensitive</varname> (int)</title>
			<para>
				Tells if the username matching should be perform case
				sensitive or not. Set it to a non zero value to force
				a case sensitive handling of usernames.
			</para>
			<para>
				<emphasis>
					Default value of this parameter is 0.
				</emphasis>
			</para>
			<example>
				<title>Set <varname>case_sensitive</varname> parameter</title>
				<programlisting format="linespecific">
...
modparam("cpl-c","case_sensitive",1)
...
</programlisting>
			</example>
		</section>
		<section id="cplc.p.realm_prefix">
			<title><varname>realm_prefix</varname> (string)</title>
			<para>
				Defines a prefix for the domain part which should be ignored
				in handling users and scripts.
			</para>
			<para>
				<emphasis>
					Default value of this parameter is empty string.
				</emphasis>
			</para>
			<example>
				<title>Set <varname>realm_prefix</varname> parameter</title>
				<programlisting format="linespecific">
...
modparam("cpl-c","realm_prefix","sip.")
...
</programlisting>
			</example>
		</section>
		<section id="cplc.p.timer_avp">
			<title><varname>timer_avp</varname> (string)</title>
			<para>
				Full specification (ID, NAME, ALIAS) of the AVP to be used to
				set the value of the Final Response INVITE timeout - it's
				used by the TIMEOUT attribute from the PROXY tag.
			</para>
			<para>
				NOTE: take care and synchronize this value with the similar
				parameters in TM module.
			</para>
			<para>
				<emphasis>
					Default value of this parameter is NULL.
				</emphasis>
			</para>
			<example>
				<title>Set <varname>timer_avp</varname> parameter</title>
				<programlisting format="linespecific">
...
modparam("cpl-c","timer_avp","$avp(i:14)")
...
</programlisting>
			</example>
		</section>
		<section id="cplc.p.lookup_domain">
			<title><varname>lookup_domain</varname> (string)</title>
			<para>
				Used by lookup tag to indicate where to perform user location.
				Basically this is the name of the usrloc domain (table) where
				the user registrations are kept.
			</para>
			<para>
				If set to empty string, the lookup node will be disabled - no
				user location will be performed.
			</para>
			<para>
				<emphasis>
					Default value of this parameter is NULL.
				</emphasis>
			</para>
			<example>
				<title>Set <varname>lookup_domain</varname> parameter</title>
				<programlisting format="linespecific">
...
modparam("cpl-c","lookup_domain","location")
...
</programlisting>
			</example>
		</section>
		<section id="cplc.p.lookup_append_branches">
			<title><varname>lookup_append_branches</varname> (int)</title>
			<para>
				Tells if the lookup tag should append branches (to do parallel
				forking) if user_location lookup returns more than one contact.
				Set it to a non zero value to enable parallel forking for
				location lookup tag.
			</para>
			<para>
				<emphasis>
					Default value of this parameter is 0.
				</emphasis>
			</para>
			<example>
				<title>Set <varname>lookup_append_branches</varname>
					parameter</title>
				<programlisting format="linespecific">
...
modparam("cpl-c","lookup_append_branches",1)
...
</programlisting>
			</example>
		</section>
		<section id="cplc.p.use_domain">
			<title><varname>use_domain</varname> (integer)</title>
			<para>
				Indicates if the domain part of the URI should be used in
				user identification (otherwise only username part will be
				used).
			</para>
			<para>
				<emphasis>
					Default value is <quote>0 (disabled)</quote>.
				</emphasis>
			</para>
			<example>
				<title>Set <varname>use_domain</varname> parameter</title>
				<programlisting format="linespecific">
...
modparam("cpl-c","use_domain",1)
...
</programlisting>
			</example>
		</section>

	</section>


	<section>
		<title>Functions</title>
		<section id="cplc.f.cpl_run_script">
			<title>
				<function moreinfo="none">cpl_run_script(type,mode, [uri])</function>
			</title>
			<para>
				Starts the execution of the CPL script. The user name is
				fetched from new_uri or requested uri or from To header -in
				this order- (for incoming execution) or from FROM header (for
				outgoing execution).
				Regarding the stateful/stateless message processing, the
				function  is very flexible, being able to run in different
				modes (see below the"mode" parameter).
				Normally this function will end script execution.  There is no
				guaranty that the CPL script interpretation ended when &kamailio;
				script ended also (for the same INVITE ;-)) - this can happen
				when the CPL script does a PROXY and the script interpretation
				pause after proxying and it will be resume when some reply is
				received (this can happen in a different process of SER).
				If the function returns to script, the SIP server should
				continue with the normal behavior as if no script existed.
				When some error is returned, the function itself haven't sent
				any SIP error reply (this can be done from script).
			</para>
			<para>Meaning of the parameters is as follows:</para>
			<itemizedlist>
			<listitem>
				<para><emphasis>type</emphasis> - which part of the script
				should be run; set it to "incoming" for having the incoming
				part of script executed (when an INVITE is received) or to
				"outgoing" for running the outgoing part of script (when a
				user is generating an INVITE - call).
				</para>
			</listitem>
			<listitem>
				<para><emphasis>mode</emphasis> - sets the interpreter mode as
				stateless/stateful behavior. The following modes are accepted:
				</para>
				<itemizedlist>
				<listitem>
					<para>
					<emphasis>IS_STATELESS</emphasis> - the current INVITE has
					no transaction created yet. All replies (redirection or
					deny) will be done is a stateless way. The execution will
					switch to stateful only when proxy is done. So, if the
					function returns, will be in stateless mode.
					</para>
				</listitem>
				<listitem>
					<para>
					<emphasis>IS_STATEFUL</emphasis> - the current INVITE has
					already a transaction associated. All signaling operations
					(replies or proxy) will be done in stateful way.So, if
					the function returns, will be in stateful mode.
					</para>
				</listitem>
				<listitem>
					<para>
					<emphasis>FORCE_STATEFUL</emphasis> - the current INVITE
					has no transaction created yet. All signaling operations
					will be done is a stateful way (on signaling, the
					transaction will be created from within the interpreter).
					So, if the function returns, will be in stateless mode.
					</para>
				</listitem>
				</itemizedlist>
				<para>
				<emphasis>HINT</emphasis>: is_stateful is very
				difficult to manage from the routing script (script processing
				can continue in stateful mode); is_stateless is the fastest and
				less resources consumer (transaction is created only if
				proxying is done), but there is minimal protection against
				retransmissions (since replies are send stateless);
				force_stateful is a good compromise - all signaling is done
				stateful (retransmission protection) and in the same time, if
				returning to script, it will be in stateless mode (easy to
				continue the routing script execution)
				</para>
			</listitem>
			<listitem>
				<para><emphasis>uri</emphasis> - optional - provide the SIP URI
				to be used for loading the CPL script, instead of taking it from
				R-URI or headers.
				</para>
			</listitem>

			</itemizedlist>
			<para>
			This function can be used from REQUEST_ROUTE.
			</para>
			<example>
				<title><function>cpl_run_script</function> usage</title>
				<programlisting format="linespecific">
...
cpl_run_script("incoming","force_stateful");
...
</programlisting>
			</example>
		</section>
		<section id="cplc.f.process_register">
			<title>
				<function moreinfo="none">cpl_process_register()</function>
			</title>
			<para>
				This function MUST be called only for REGISTER requests. It
				checks if the current REGISTER request is related or not with
				CPL script upload/download/ remove. If it is, all the needed
				operation will be done. For checking if the REGISTER is CPL
				related, the function looks fist to "Content-Type" header. If
				it exists and has a the mime type set to "application/cpl+xml"
				means this is a CPL script upload/remove operation. The
				distinction between to case is made by looking at
				"Content-Disposition" header; id its value is
				"script;action=store", means it's an upload; if it's
				"script;action=remove", means it's a remove operation; other
				values are considered to be errors. If no "Content-Type"
				header is present, the function looks to "Accept" header and
				if it contains the "*" or "application/cpl-xml" the request
				it will be consider one for downloading CPL scripts.
				The functions returns to script only if the REGISTER is
				not related to CPL. In other case, the function will send by
				itself the necessary replies (stateless - using sl), including
				for errors.
			</para>
			<para>
			This function can be used from REQUEST_ROUTE.
			</para>
			<example>
				<title><function>cpl_process_register</function> usage</title>
				<programlisting format="linespecific">
...
if (method=="REGISTER") {
    cpl_process_register();
}
...
</programlisting>
			</example>
		</section>
		<section id="cplc.p.process_register_norpl">
			<title>
				<function moreinfo="none">cpl_process_register_norpl()
					</function>
			</title>
			<para>
				Same as <quote>cpl_process_register</quote> without
				internally generating the reply. All information (script) is
				appended to the reply but without sending it out.
			</para>
			<para>
				Main purpose of this function is to allow integration
				between CPL and UserLocation services via same REGISTER
				messages.
			</para>
			<para>
			This function can be used from REQUEST_ROUTE.
			</para>
			<example>
				<title><function>cpl_process_register_norpl</function> usage
					</title>
				<programlisting format="linespecific">
...
if (method=="REGISTER") {
    cpl_process_register();
    # continue with usrloc part
    save("location");
}
...
</programlisting>
			</example>
		</section>
	</section>

	<section>
		<title>RPC Commands</title>
		<section id="cpl.r.load">
			<title>cpl.load</title>
			<para>
			For the given user, loads the XML cpl file, compiles it into
			binary format and stores both format into database.
			</para>
			<para>
			Name: <emphasis>cpl.load</emphasis>
			</para>
			<para>Parameters:</para>
			<itemizedlist>
			<listitem><para>username : name of the user</para></listitem>
			<listitem><para>cpl_filename: file name </para></listitem>
			</itemizedlist>
			<para>
			RPC Command format:
			</para>
			<programlisting format="linespecific">
...
&kamcmd; cpl.load username cpl_filename
...
</programlisting>
		</section>

		<section id="cpl.r.remove">
			<title>cpl.remove</title>
			<para>
			For the given user, removes the entire database record
			(XML cpl and binary cpl); user with empty cpl scripts are not
			accepted.
			</para>
			<para>
			Name: <emphasis>cpl.remove</emphasis>
			</para>
			<para>Parameters:</para>
			<itemizedlist>
			<listitem><para>username : name of the user</para></listitem>
			</itemizedlist>
			<para>
			RPC Command format:
			</para>
			<programlisting format="linespecific">
...
&kamcmd; cpl.remove username
...
</programlisting>
		</section>

		<section id="cpl.r.get">
			<title>cpl.get</title>
			<para>
			For the given user, returns the CPL script in XML format.
			</para>
			<para>
			Name: <emphasis>cpl.get</emphasis>
			</para>
			<para>Parameters:</para>
			<itemizedlist>
			<listitem><para>username : name of the user</para></listitem>
			</itemizedlist>
			<para>
			RPC Command format:
			</para>
			<programlisting format="linespecific">
...
&kamcmd; cpl.get username
...
</programlisting>
		</section>
	</section>

	<section>
		<title>Installation and Running</title>
		<section>
			<title>Database setup</title>
			<para>
			Before running &kamailio; with cpl-c, you have to setup the database 
			table where the module will store the CPL scripts. For that, if
			the table was not created by the installation script or you choose
			to install everything by yourself you can use the cpc-create.sql
			<acronym>SQL</acronym> script in the database directories in the
			kamailio/scripts folder as template.
			Database and table name can be set with module parameters so they
			can be changed, but the name of the columns must be as they are
			in the <acronym>SQL</acronym> script.
			You can also find the complete database documentation on the
			project webpage, &kamailiodbdocslink;.
			</para>
		</section>
	</section>
</chapter>

