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

<chapter>

    <title>&adminguide;</title>

    <section>
	<title>Overview</title>
	<para>
		This module provides an interactive config file debugger. It can print
		a trace of config script execution for a SIP message to log and set
		breakpoints on every script action, allowing step-by-step execution of
		the routing and response scripts. Moreover, this module allows setting
		static and dynamic module specific debug settings.
	</para>
	<para>
		Debugging can be done from local or remote host via RPC interface (e.g.,
		XMLRPC, &sercmd;, siremis).
	</para>
	<para>
		The framework to set breakpoints on specific actions and config lines
		is not exported to RPC. Each action can be accompanied by a
		breakpoint or you can use dbg_breakpoint() function to set a breakpoint
		at certain line. Global breakpoints can be enabled/disabled at runtime.
		The script running trace can also be enabled/disabled at runtime.
	</para>
	<para>
		When the SIP router process is stopped at a breakpoint, you can
		investigate the values of any pseudo-variables. Note that some of
		pseudo-variables may produce memory leaks; a fix is planned in the
		future (here fall pseudo-variables with dynamic name such as htable,
		sqlops). References to SIP message, avps, headers, script and shared
		variables are safe.
	</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>none</emphasis>.
			</para>
		    </listitem>
	    	</itemizedlist>
	    </para>
	    <para>
		NOTE: Due to the debugger module child_init() function, one should load the module first in the module sequence in order to initialize _dbg_pid_list.
		Otherwise, another module (i.e. p_usrloc) forking a process with rank != PROC_INIT will fail.
	    </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>None</emphasis>.
			</para>
		    </listitem>
	    	</itemizedlist>
	    </para>
	</section>
    </section>
    <section>
	<title>Parameters</title>
	<section id="dbg.p.cfgtrace">
	    <title><varname>cfgtrace</varname> (int)</title>
	    <para>
			Control whether the config script trace is enabled or disabled
			at startup. You can change the value at runtime without
			restart, globally or per process.
	    </para>
	    <para>
		<emphasis>
		    Default value is <quote>0</quote> (disabled).
		</emphasis>
	    </para>
	    <example>
		<title>Set <varname>cfgtrace</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("debugger", "cfgtrace", 1)
...
</programlisting>
	    </example>
	</section>

	<section id="dbg.p.cfgtrace_format">
	    <title><varname>cfgtrace_format</varname> (int)</title>
	    <para>
			Control what is printer in the cfgtrace log message. If it is set
			to 1, then the configuration file path is not printed, making
			the log messages shorter when not including other configuration
			files in the main one.
	    </para>
	    <para>
		<emphasis>
		    Default value is <quote>0</quote>.
		</emphasis>
	    </para>
	    <example>
		<title>Set <varname>cfgtrace_format</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("debugger", "cfgtrace_format", 1)
...
</programlisting>
	    </example>
	</section>

	<section id="dbg.p.breakpoint">
	    <title><varname>breakpoint</varname> (int)</title>
	    <para>
			Control whether every line (global) breakpoint is enabled
			or disabled at startup.
	    </para>
	    <para>
		<emphasis>
		    Default value is <quote>0</quote> (disabled).
		</emphasis>
	    </para>
	    <example>
		<title>Set <varname>breakpoint</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("debugger", "breakpoint", 1)
...
</programlisting>
	    </example>
	</section>

	<section id="dbg.p.log_level">
	    <title><varname>log_level</varname> (int)</title>
	    <para>
			What log level is to be used to print module-specific messages.
	    </para>
	    <para>
		<emphasis>
		    Default value is <quote>-1</quote> (L_ERR).
		</emphasis>
	    </para>
	    <example>
		<title>Set <varname>log_level</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("debugger", "log_level", 1)
...
</programlisting>
	    </example>
	</section>

	<section id="dbg.p.log_level_name">
	    <title><varname>log_level_name</varname> (str)</title>
	    <para>
			What log level name is to be used to print cfg trace messages.
	    </para>
	    <para>
		<emphasis>
		    Default value is <quote>NULL</quote> (use default log names).
		</emphasis>
	    </para>
	    <example>
		<title>Set <varname>log_level_name</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("debugger", "log_level_name", "exec")
...
</programlisting>
	    </example>
	</section>

	<section id="dbg.p.log_facility">
	    <title><varname>log_facility</varname> (str)</title>
	    <para>
			Which log facility is to be used to print module-specific messages.
			By using this setting, you can configure syslog to send debug
			messages to a separate log channel, like a specific kamailio-debug log file.
	    </para>
	    <para>
		<emphasis>
		    Default value is <quote>NULL</quote> (default from core).
		</emphasis>
	    </para>
	    <example>
		<title>Set <varname>log_facility</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("debugger", "log_facility", "LOG_DAEMON")
...
</programlisting>
	    </example>
	</section>

	<section id="dbg.p.log_prefix">
	    <title><varname>log_prefix</varname> (str)</title>
	    <para>
			String to print before any module-specific messages.
	    </para>
	    <para>
		<emphasis>
		    Default value is <quote>*** cfgtrace:</quote>.
		</emphasis>
	    </para>
	    <example>
		<title>Set <varname>log_prefix</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("debugger", "log_prefix", "from-debugger-with-love:")
...
</programlisting>
	    </example>
	</section>

	<section id="dbg.p.step_usleep">
	    <title><varname>step_usleep</varname> (int)</title>
	    <para>
			Microseconds to sleep before checking for new commands when
			waiting at a breakpoint.
	    </para>
	    <para>
		<emphasis>
		    Default value is <quote>100000</quote> (that is 0.1 sec).
		</emphasis>
	    </para>
	    <example>
		<title>Set <varname>step_usleep</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("debugger", "step_usleep", 500000)
...
</programlisting>
	    </example>
	</section>

	<section id="dbg.p.step_loops">
	    <title><varname>step_loops</varname> (int)</title>
	    <para>
			How many sleeps of 'step_usleep' the RPC process performs when
			waiting for a reply from a worker process before responding to RPC.
			This avoids blocking RPC process forever in case the worker
			process 'forgets' to write back a reply.
	    </para>
	    <para>
		<emphasis>
		    Default value is <quote>200</quote>.
		</emphasis>
	    </para>
	    <example>
		<title>Set <varname>step_loops</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("debugger", "step_loops", 100)
...
</programlisting>
	    </example>
	</section>

	<section id="dbg.p.mod_hash_size">
	    <title><varname>mod_hash_size</varname> (int)</title>
	    <para>
		Used to compute power of two as size of internal hash table to store levels
		per module (e.g., if it is set to 4, internal hash table has 16 slots). One
		must set its value grater than 0 such that memory to be allocated
		to save the module specific debug levels or facility configured by
		<varname>mod_level</varname> or <varname>mod_facility</varname>.
		This parameter is accessible readonly via the Kamailio config framework.
	    </para>
	    <para>
		<emphasis>
		    Default value is <quote>0</quote> - feature disabled.
		</emphasis>
	    </para>
	    <example>
		<title>Set <varname>mod_hash_size</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("debugger", "mod_hash_size", 5)
...
</programlisting>
	    </example>
	</section>

	<section id="dbg.p.mod_level_mode">
	    <title><varname>mod_level_mode</varname> (int)</title>
	    <para>
			Enable or disable per module log level (0 - disabled, 1 - enabled).
			This parameter is tunable via the Kamailio config framework. To use
			per module log level you also have to set <varname>mod_hash_size</varname>.
	    </para>
	    <para>
		<emphasis>
		    Default value is <quote>0</quote>.
		</emphasis>
	    </para>
	    <example>
		<title>Set <varname>mod_level_mode</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("debugger", "mod_level_mode", 1)
...
</programlisting>
	    </example>
	</section>

	<section id="dbg.p.mod_level">
	    <title><varname>mod_level</varname> (str)</title>
	    <para>
		Specify module log level - the value must be in the format:
		modulename=level. The parameter can be set many times. For core
		log level, use module name 'core'. You also must enable
		<varname>mod_level_mode</varname> and <varname>mod_hash_size</varname>.
	    </para>
	    <example>
		<title>Set <varname>mod_level</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("debugger", "mod_level", "core=3")
modparam("debugger", "mod_level", "tm=3")
...
</programlisting>
	    </example>
	</section>

	<section id="dbg.p.mod_facility_mode">
	    <title><varname>mod_facility_mode</varname> (int)</title>
	    <para>
			Enable or disable per module log facility (0 - disabled, 1 - enabled).
			This parameter is tunable via the Kamailio config framework. To use
			per module log facility you also have to set <varname>mod_hash_size</varname>.
	    </para>
	    <para>
		<emphasis>
		    Default value is <quote>0</quote>.
		</emphasis>
	    </para>
	    <example>
		<title>Set <varname>mod_facility_mode</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("debugger", "mod_facility_mode", 1)
...
        </programlisting>
	    </example>
	</section>

	<section id="dbg.p.mod_facility">
	    <title><varname>mod_facility</varname> (str)</title>
	    <para>
		Specify module log facility - the value must be in the format:
		modulename=facility. The parameter can be set many times. For core
		log facility, use module name 'core'. You also must enable
		<varname>mod_facility_mode</varname> and <varname>mod_hash_size</varname>.
	    </para>
        <para>
        NOTE: See the <emphasis>syslog()</emphasis> library call for facility names (http://linux.die.net/man/3/syslog).
        The most used facilities are LOG_LOCAL[0-7].
        </para>

	    <example>
		<title>Set <varname>mod_facility</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("debugger", "mod_facility", "core=LOG_LOCAL0")
modparam("debugger", "mod_facility", "debugger=LOG_LOCAL1")
...
        </programlisting>
	    </example>
	</section>

	<section id="dbg.p.log_assign">
	    <title><varname>log_assign</varname> (int)</title>
	    <para>
		Enable or disable log assign actions on config (0 - disabled, 1 - enabled).
	    </para>
		<para>
		<emphasis>
		    Default value is <quote>0</quote>.
		</emphasis>
	    </para>
	    <example>
		<title>Set <varname>log_assign</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("debugger", "log_assign", 1)
...
</programlisting>
	    </example>
	</section>

	<section id="dbg.p.cfgpkgcheck">
	    <title><varname>cfgpkgcheck</varname> (int)</title>
	    <para>
			If set, before each config action is done pkg memory check,
			useful to detect buffer overflows.
	    </para>
	    <para>
		<emphasis>
		    Default value is <quote>0</quote> (disabled).
		</emphasis>
	    </para>
	    <example>
		<title>Set <varname>cfgpkgcheck</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("debugger", "cfgpkgcheck", 1)
...
</programlisting>
	    </example>
	</section>

	<section id="dbg.p.reset_msgid">
	    <title><varname>reset_msgid</varname> (int)</title>
	    <para>
		Used to enable or disable the ability to reset the msgid ($mi)
		through the dbg.reset_msgid RPC command. (0 - disabled, 1 - enabled).
	    </para>
	    <para>
		<emphasis>
		    Default value is <quote>0</quote> - feature disabled.
		</emphasis>
	    </para>
	    <example>
		<title>Set <varname>reset_msgid</varname> parameter</title>
		<programlisting format="linespecific">
...
modparam("debugger", "reset_msgid", 1)
...
</programlisting>
	    </example>
	</section>

	<section id="dbg.p.cfgtest">
	    <title><varname>cfgtest</varname> (int)</title>
	    <para>
			Control whether the cfgt module is enabled or disabled
			at startup. Module cfgt needs to be loaded before.
	    </para>
	    <para>
		<emphasis>
		    Default value is <quote>0</quote> (disabled).
		</emphasis>
	    </para>
	    <example>
		<title>Set <varname>cfgtest</varname> parameter</title>
		<programlisting format="linespecific">
...
loadmodule "cfgt.so"
modparam("debugger", "cfgtest", 1)
...
</programlisting>
	    </example>
	</section>

	</section>

    <section>
	<title>Functions</title>
 	<section id="dbg.f.db_breakpoint">
	    <title>
		<function moreinfo="none">dbg_breakpoint(mode)</function>
	    </title>
	    <para>
			Anchor a breakpoint at the current line of the config (the one
			on which this function is called). The 'mode' specifies whether
			the breakpoint is enabled (1) or disabled (0) at startup.
	    </para>
		<para>
			Note that this version of the module does not export this anchors to RPC for
			interactive debugging (temporarily disabled).
	    </para>
		<example>
		<title><function>dbg_breakpoint</function> usage</title>
		<programlisting format="linespecific">
...
if($si=="10.0.0.10")
	dbg_breakpoint("1");
...
</programlisting>
	    </example>
	</section>

	<section id="dbg.f.dbg_pv_dump">
	    <title>
		<function moreinfo="none">dbg_pv_dump([mask] [, level])</function>
	    </title>
	    <para>
			Prints the content of pv_cache on json format.
			Defaults are mask=31 and level = "L_DBG"
	    </para>
		<para>
		</para>
		<itemizedlist>
			<para><emphasis>mask</emphasis> - Controls the content to dump:
			</para>
			<itemizedlist>
			<listitem><para>
			  1 - dump null values
			</para></listitem>
			<listitem><para>
			  2 - dump avp vars
			</para></listitem>
			<listitem><para>
			  4 - dump script vars
			</para></listitem>
			<listitem><para>
			  8 - dump xavp vars
			</para></listitem>
			<listitem><para>
			  16 - dump DP_OTHER vars
			</para></listitem>
			</itemizedlist>
			<para><emphasis>level</emphasis> - The level that will be used in LOG function. It can be:
			</para>
			<itemizedlist>
			<listitem><para>
				L_ALERT - log level -5
			</para></listitem>
			<listitem><para>
				L_BUG - log level -4
			</para></listitem>
			<listitem><para>
				L_CRIT - log level -3
			</para></listitem>
			<listitem><para>
				L_ERR - log level -1
			</para></listitem>
			<listitem><para>
				L_WARN - log level 0
			</para></listitem>
			<listitem><para>
				L_NOTICE - log level 1
			</para></listitem>
			<listitem><para>
				L_INFO - log level 2
			</para></listitem>
			<listitem><para>
				L_DBG - log level 3
				</para></listitem>
			</itemizedlist>
		</itemizedlist>
		<example>
		<title><function>dbg_pv_dump</function> usage</title>
		<programlisting format="linespecific">
...
$var(temp) = 1;
$avp(s:more_avp) = 2;
$avp(s:more_avp) = 3;
$xavp(x=>more) = "bye";
$xavp(x[0]=>more) = "hi";
$xavp(x[0]=>other) = 1;
$xavp(x[0]=>other) = 2;
$xavp(x=>different) = "foo";
$var(empty) = $null;

dbg_pv_dump(30, "L_DBG");
...
</programlisting>
		<para>Output</para>
		<programlisting format="linespecific">
...
 4(30943) DEBUG: debugger [debugger_api.c:1613]: dbg_dump_json(): {"$sp":37597,"$var(rc)":0,"$var(temp)":1,"$avp(more_avp)":[3,2],"$si":"127.0.0.1","$rc":0,"$xavp(x)":[{"different":["foo"]},{"other":[2,1],"more":["hi","bye"]}],"$T_branch_idx":0,"$var(empty)":0}
 ...
</programlisting>
	    </example>
	</section>

 	<section id="dbg.f.dbg_sip_msg">
	    <title>
		<function moreinfo="none">dbg_sip_msg([log_level], [facility])</function>
	    </title>
	    <para>
            Prints how the sip message <emphasis>would look</emphasis> like if it <emphasis>would be sent</emphasis> out
            at that point in the config(i.e. if the current lump lists would
            have been applied at that point in the config).

            It also prints a diff list for both header and body of sip msg
            which contain the lump lists content. The lumps deleted are printed
            with "-" sign whereas the lumps added have no sign. The config line
            where the function has been called is also printed.
	    </para>
	    <para>
            NOTE that dbg_sip_msg function does not modify the initially received SIP message.
            Just displays how it WOULD look like if it were to send it at that point.
	    </para>
		<para>
			NOTE that the lump lists are usually applied only once, just before sending, to spare message reparse processing.
            All the changes present in lump list are applied on the <emphasis>initially received</emphasis> SIP message.
            One can force the lump application using msg_apply_changes() function from textopsx module.
	    </para>
		<para>
	    </para>
		<example>
		<title><function>dbg_sip_msg</function> usage</title>
		<programlisting format="linespecific">
...
    dbg_sip_msg();
    dbg_sip_msg("L_ERR");
    dbg_sip_msg("L_ERR", "LOG_LOCAL0");
...
        </programlisting>

		<para>Output when dbg_sip_msg("L_ERR") is called after <emphasis>append_hf("P-Hint: My hint\r\n"); remove_hf("Contact");</emphasis></para>
		<programlisting format="linespecific">
ERROR: debugger [debugger_mod.c:467]: w_dbg_sip_msg(): CONFIG LINE 338
------------------------- START OF SIP message debug --------------------------
OPTIONS sip:nobody@127.0.0.1 SIP/2.0
Via: SIP/2.0/UDP 127.0.1.1:56872;branch=z9hG4bK.6d7c487a;rport;alias
From: sip:sipsak@127.0.1.1:56872;tag=188b7433
To: sip:nobody@127.0.0.1
Call-ID: 411792435@127.0.1.1
CSeq: 1 OPTIONS
Content-Length: 0
Max-Forwards: 70
User-Agent: sipsak 0.9.6
Accept: text/plain
P-Hint: My hintt

------------------------------ SIP header diffs -------------------------------
- Contact: sip:sipsak@127.0.1.1:56872
P-Hint: My hint
------------------------------- SIP body diffs --------------------------------
-------------------------- END OF SIP message debug ---------------------------
        </programlisting>
	    </example>
    </section>

    </section>


	<section>
		<title>RPC Commands</title>

	<section id="dbg.r.ls">
		<title>
		<function moreinfo="none">dbg.ls</function>
		</title>
		<para>
			List &kamailio; processes with info related to interactive
			debugging.
		</para>
		<para>
		Name: <emphasis>dbg.list</emphasis>
		</para>
		<para>Parameters:</para>
		<itemizedlist>
			<listitem><para>_pid_ : pid for which to list the details.  If 'pid' is
			omitted then will print for all processes.</para></listitem>
		</itemizedlist>
		<para>
		Examples of use with &sercmd;:
		</para>
        <programlisting  format="linespecific">
		dbg.ls
		dbg.ls 1234
		</programlisting>
    </section>

	<section id="dbg.r.trace">
		<title>
		<function moreinfo="none">dbg.trace</function>
		</title>
		<para>
			Control config script running trace.
		</para>
		<para>
		Name: <emphasis>dbg.trace</emphasis>
		</para>
		<para>Parameters:</para>
		<itemizedlist>
			<listitem><para>_cmd_ : command can be 'on' or 'off' to
				enable or disable tracing for one or all processes.</para>
		</listitem>
			<listitem><para>_pid_ : pid for which to list the details. If 'pid' is
				omitted, then details for all processes will be printed.</para>
		</listitem>
		</itemizedlist>
		<para>
		Examples for using with &sercmd;:
		</para>
        <programlisting  format="linespecific">
		dbg.trace on
		dbg.trace off
		dbg.trace on 1234
		</programlisting>
    </section>

	<section id="dbg.r.bp">
		<title>
		<function moreinfo="none">dbg.bp</function>
		</title>
		<para>
			Control breakpoints and config execution.
		</para>
		<para>
		Name: <emphasis>dbg.bp</emphasis>
		</para>
		<para>Parameters:</para>
		<itemizedlist>
			<listitem><para>_cmd_ : command, see next section for
			the list of available values.</para>
		</listitem>
		<listitem><para>_pid_ : process id for which to apply the command.
				If 'pid' is omitted, then the inner command will be applied
				to all processes.</para>
		</listitem>
		<listitem><para>_params_ : extra params specific for each command.</para>
		</listitem>
		</itemizedlist>
		<para>Commands:</para>
		<itemizedlist>
		<listitem>
			<para>on - turn on breakpoints. Pid parameter is optional.
			</para>
		</listitem>
		<listitem>
			<para>off - turn off breakpoints. Pid parameter is optional.
			</para>
		</listitem>
		<listitem>
			<para>keep - keep breakpoints only for pid given as parameter
			</para>
		</listitem>
		<listitem>
			<para>release - disable breakpoints for processes that are
			not waiting at a breakpoint. Pid parameter is optional.</para>
		</listitem>
		<listitem>
			<para>next - run the action under breakpoint and stop at next one
			(step by step execution). Pid parameter is mandatory.
			</para>
		</listitem>
		<listitem>
			<para>move - run the action under breakpoint and remove the rest
			of breakpoints (continue execution without stopping again at next
			actions). Pid parameter is mandatory.</para>
		</listitem>
		<listitem>
			<para>show - print details about the current breakpoint for pid.
			Pid parameter is mandatory.</para>
		</listitem>
		<listitem>
			<para>eval - evaluate a pseudo-variable and print the result in RPC
			Pid parameter is mandatory.</para>
		</listitem>
		<listitem>
			<para>log - evaluate a pseudo-variable and print the result in SIP
			router logs. Pid parameter is mandatory.</para>
		</listitem>
		</itemizedlist>
		<para>
		Examples for using with &sercmd;:
		</para>
        <programlisting  format="linespecific">
		dbg.bp off
		dbg.bp on
		dbg.bp release
		dbg.bp on 1234
		dbg.bp eval 1234 $fu
		dbg.bp move 1234
		</programlisting>
    </section>

    <section id="dbg.r.mod_level">
		<title>
		<function moreinfo="none">dbg.mod_level</function>
		</title>
		<para>
			Specify module log level.
		</para>
		<para>
		Name: <emphasis>dbg.mod_level</emphasis>
		</para>
		<para>Parameters:</para>
		<itemizedlist>
			<listitem><para>_module_ : For core log
				level, use module name 'core'</para></listitem>
			<listitem><para>_level_ : integer</para></listitem>
		</itemizedlist>
		<para>
		Examples of use with &sercmd;:
		</para>
        <programlisting  format="linespecific">
		dbg.mod_level core 3
		dbg.mod_level tm 3
		</programlisting>
    </section>

	<section id="dbg.r.reset_msgid">
		<title>
		<function moreinfo="none">dbg.reset_msgid</function>
		</title>
		<para>
			Resets the message sequence ($mi). Internally there is no real change.
			This can be useful for unit test cases in order to be able to replicate
			exactly the same kamailio output.

			You need to set the debugger parameter reset_msgid to 1 to activate this
			functionality.
		</para>
		<para>
		Name: <emphasis>dbg.reset_msgid</emphasis>
		</para>
		<para>
		Examples of use with &sercmd;:
		</para>
        <programlisting  format="linespecific">
		dbg.reset_msgid
		</programlisting>
    </section>

	<section id="dbg.r.set_mod_level">
		<title>
			<function moreinfo="none">dbg.set_mod_level</function>
		</title>
		<para>
			Set the module log level.
			If module does not exist in kamailio, the entry in the level hashtable is still added for the bogus module.
		</para>
		<para>
			Name: <emphasis>dbg.set_mod_level</emphasis>
		</para>
		<para>
			Examples of use with &sercmd;:
		</para>
		<programlisting  format="linespecific">
			dbg.set_mod_level core 1
		</programlisting>
	</section>

	<section id="dbg.r.set_mod_facility">
		<title>
			<function moreinfo="none">dbg.set_mod_facility</function>
		</title>
		<para>
			Set the module log facility.
			If module does not exist in kamailio, the entry in the facility hashtable is still added for the bogus module.
		</para>
		<para>
			Name: <emphasis>dbg.set_mod_facility</emphasis>
		</para>
		<para>
			Examples of use with &sercmd;:
		</para>
		<programlisting  format="linespecific">
			dbg.set_mod_facility core LOG_LOCAL1
		</programlisting>
	</section>

	<section id="dbg.r.get_mod_level">
		<title>
			<function moreinfo="none">dbg.get_mod_level</function>
		</title>
		<para>
			Get the module log level.
			If mod_name does not exist in the level hashtable, returns the config file value.
		</para>
		<para>
			Name: <emphasis>dbg.get_mod_level</emphasis>
		</para>
		<para>
			Examples of use with &sercmd;:
		</para>
		<programlisting  format="linespecific">
			dbg.get_mod_level core
		</programlisting>
	</section>

	<section id="dbg.r.get_mod_facility">
		<title>
			<function moreinfo="none">dbg.get_mod_facility</function>
		</title>
		<para>
			Get the module log facility.
			If mod_name does not exist in the facility hashtable, returns the config file value.
		</para>
		<para>
			Name: <emphasis>dbg.get_mod_facility</emphasis>
		</para>
		<para>
			Examples of use with &sercmd;:
		</para>
		<programlisting  format="linespecific">
			dbg.get_mod_facility core
		</programlisting>
	</section>

    </section>


	<section>
		<title>Usage</title>
		<para>
		A common usage is to investigate the execution path for a specific
		SIP message. Just enable cfg running trace, send the message and
		watch the logs.
		</para>
		<para>
		Another typical usage is to do interactive debugging and run
		each line of the route blocks of the configuration file step-by-step for a
		particular SIP message.
		</para>
		<para>
		You need to connect using &sercmd; (or other RPC client) to &kamailio;.
		Then you can enable cfg breakpoints and send the SIP message. One
		process will be in waiting state ('state' field different than 0 when
		you do dbg.ls). Calling dbg.release will set the other &kamailio;
		processes in no-breakpoint mode so they can process other SIP messages
		without need to interact with them.
		</para>
		<para>
		A process blocked at a breakpoint is waiting for a command. Use
		'dbg.bp next pid' to execute the current action and stop at the next
		one. 'dbg.bp eval pid PV' can be used to retrieve the value of PV. Once
		you are done and want to continue the execution of the config without
		interaction use 'dbg.bp move pid'.
		</para>
		<para>
		Example of a session:
		</para>
<programlisting  format="linespecific">
...
&sercmd;> dbg.ls
{
	entry: 0
	pid: 6393
	set: 3
	state: 0
	in.pid: 0
	in.cmd: 0
}
{
	entry: 1
	pid: 6394
	set: 3
	state: 0
	in.pid: 0
	in.cmd: 0
}
...
{
	entry: 9
	pid: 6402
	set: 3
	state: 1
	in.pid: 0
	in.cmd: 0
}

&sercmd;> dbg.bp show 6402
at bkp [/etc/kamailio/debugger.cfg:369] a=6 n=route

&sercmd;> dbg.bp next 6402
exec [/etc/kamailio/debugger.cfg:369] a=6 n=route

&sercmd;> dbg.bp next 6402
exec [/etc/kamailio/debugger.cfg:462] a=17 n=if

&sercmd;> dbg.bp eval 6402 $fu
$fu : t=str v=sip:test@kamailio.org

&sercmd;> dbg.bp move 6402
200 ok
...
</programlisting>
		<para>
		Running the config trace looks like:
		</para>
<programlisting  format="linespecific">
...
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=368 a=6 n=route
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=461 a=17 n=if
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=456 a=26 n=mf_process_maxfwd_header
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=466 a=17 n=if
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=461 a=27 n=sanity_check
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=371 a=6 n=route
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=659 a=3 n=return
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=374 a=6 n=route
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=501 a=17 n=if
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=470 a=25 n=has_totag
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=386 a=17 n=if
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=379 a=26 n=is_method
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=386 a=25 n=t_check_trans
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=389 a=6 n=route
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=643 a=3 n=return
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=393 a=26 n=remove_hf
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=398 a=17 n=if
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=394 a=26 n=is_method
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=404 a=17 n=if
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=398 a=26 n=is_method
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=404 a=6 n=route
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=682 a=17 n=if
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=409 a=6 n=route
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=575 a=17 n=if
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=550 a=26 n=is_method
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=551 a=3 n=return
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=412 a=6 n=route
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=518 a=17 n=if
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=505 a=26 n=is_method
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=513 a=17 n=if
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=507 a=42 n=isflagset
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=516 a=17 n=if
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=513 a=26 n=save
 9(6285) ERROR: *** cfgtrace: c=[/etc/kamailio/debugger.cfg] l=516 a=3 n=exit
...
</programlisting>
		<para>
			The above example is for a registration with default config for
			version 3.1.0, without authentication. Listed fields are:
			'c' - config file; 'l' - line; 'a' - internal action id;
			'n' - name of executed action. 'ERROR' prefix is printed
			because these messages were sent to the L_ERR log level.
		</para>
    </section>

</chapter>

