Table of Contents
List of Examples
cfgtrace parameterbreakpoint parameterlog_level parameterlog_facility parameterlog_prefix parameterstep_usleep parameterstep_loops parameterdbg_breakpoint usageTable of Contents
This module provides an interactive config file debugger. It can print a trace of config execution for a SIP message to log and set breakpoints on every config action, allowing step-by-step execution of the config.
Debugging can be done from local or remote host via RPC interface (e.g., XMLRPC, sercmd, siremis).
The framework to set breakpoints on specific actions and config lines is not exported to RPC yet. Each action can be accompanied by an breakpoint or you can use dbg_breakpoint() function to set a breakpoint at certain line. Global breakpoint can be enabled/disabled at runtime. Also the config running trace can be enabled/disabled at runtime.
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.
Control whether config running trace is enabled or disabled at startup. You can change the value at runtime without restart, globally or per process.
Default value is “0” (disabled).
Control whether every line (global) breakpoint is enabled or disabled at startup.
Default value is “0” (disabled).
What log level is to be used to print module-specific messages.
Default value is “-1” (L_ERR).
What log facility is to be used to print module-specific messages.
Default value is “NULL” (default from core).
String to print before any module-specific messages.
Default value is “*** cfgtrace:”.
Example 1.5. Set log_prefix parameter
...
modparam("debugger", "log_prefix", "from-debugger-with-love:")
...
Microseconds to sleep before checking for new commands when waiting at breakpoint.
Default value is “100000” (that is 0.1 sec).
How many sleeps of 'step_usleep' the RPC process performs when waiting for a reply from worker process before responding to RPC. This avoids blocking RPC process forever in case the worker process 'forgets' to write back a reply.
Default value is “200”.
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.
Note that this version does not export this anchors to RPC for interactive debugging (temporarily disabled).
List SIP router processes with info related to interactive debugging.
Name: dbg.list
Parameters:
_pid_ : pid for which to list the details. If 'pid' is omitted then will print for all processes.
Examples of use with sercmd:
dbg.ls dbg.ls 1234
Control config running trace.
Name: dbg.trace
Parameters:
_cmd_ : inner command can be 'on' or 'off' to enable or disable tracing for one or all processes.
_pid_ : pid for which to list the details. If 'pid' is omitted, then it will print details for all processes.
Examples for using with sercmd:
dbg.trace on dbg.trace off dbg.trace on 1234
Control breakpoints and config execution.
Name: dbg.bp
Parameters:
_cmd_ : inner command, see next section for the list of available values.
_pid_ : pid for which to apply the inner command. If 'pid' is omitted, then the inner command will be applied to all processes.
_params_ : extra params specific for each inner command.
Inner commands:
on - turn on breakpoints. Pid parameter is optional.
off - turn off breakpoints. Pid parameter is optional.
keep - keep breakpoints only for pid given as parameter
release - disable breakpoints for processes that are not waiting at a breakpoint. Pid parameter is optional.
next - run the action under breakpoint and stop at next one (step by step execution). Pid parameter is mandatory.
move - run the action under breakpoint and remove the rest of breakpoints (continue execution without stopping again at next actions). Pid parameter is mandatory.
show - print details about the current breakpoint for pid. Pid parameter is mandatory.
eval - eval a pseudo-variable and print the result in RPC Pid parameter is mandatory.
log - eval a pseudo-variable and print the result in SIP router logs. Pid parameter is mandatory.
Examples for using with sercmd:
dbg.bp off dbg.bp on dbg.bp release dbg.bp on 1234 dbg.bp eval 1234 $fu dbg.bp move 1234
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.
Another typical usage is to do interactive debugging and run each line of the route blocks of the config file step-by-step for a particular SIP message.
You need to connect using sercmd (or other RPC client) to SIP Router. 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 SIP router processes in no-breakpoint mode so they can process other SIP messages without need to interact with them.
The process blocked at 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 retrive the value of PV. Once you are done and want to continue the execution of the config wihtout interaction use 'dbg.bp move pid'.
Here is an example of session:
...
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
...
Running the config trace looks like:
... 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 ...
The above example is for 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.