Hi,
ok, time to continue here a little bit.
Stefan Sayer wrote:
Hi,
it's raining, so seems like its good time for a second part of this
small DSM tutorial.
Stefan Sayer wrote:
David J. wrote:
Hi Stefan,
I am trying to accomplish a script that parallel forks to many
callers and then the one who enters the right DTMF code gets the call.
In order to do this, I am guessing, I need b2b_mode which sends
RINGING back to the Caller, does the forking plays a WAV/MP3
announcement to the Callee's and some sort of DTMF detection that
captures the dialed digits and verify's them via script, database or
whatever.
actually, in order to be able to prompt the callees and collect the
DTMF from them, you will have to establish separate calls to them - so
that b2b mode is not really suitable. Once the right callee leg is
identified, though, you can connect audio from the caller and the
callee leg by joining the same conference room. You can interact
between the two legs (e.g. when one hangs up) by sending events back
and forth, the only thing you need is to know in both legs is the id
of the other leg (local-tag).
But, to start from the beginning. We will need two DSM scripts, one
for the caller, one for the callee leg. We call that application
quizconnect, and we tell dsm to load DSM application configurations by
setting in dsm.conf:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
conf_dir=/usr/local/etc/sems/dsm/
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Then we can create /usr/local/etc/sems/dsm/quizconnect.conf which
loads the scripts and sets the settings for the quizconnect application:
/usr/local/etc/sems/dsm/quizconnect.conf:
-----------------------------------
diag_path=/usr/local/lib/sems/dsm/quizconnect/
load_diags=quizconnect_caller,quizconnect_callee
register_apps=quizconnect_caller,quizconnect_callee
mod_path=/usr/local/lib/sems/dsm/
preload_mods=mod_mysql
run_invite_event=yes
set_param_variables=yes
#run_system_dsms=
# some configuration parameters
# - can be used with e.g. $config.prompt_path
prompt_path=/usr/local/lib/sems/dsm/quizconnect/prompts/
-----------------------------------
We have preloaded the mysql module, which needs this to be initialized
and read its configuration (which contains the DB connection, for
example). We also set run_invite_event=yes in the dsm config, that way
we get an 'invite' event into the DSM scripts. Now we create two
scripts, /usr/local/lib/sems/dsm/quizconnect/quizconnect_caller.dsm
and /usr/local/lib/sems/dsm/quizconnect/quizconnect_callee.dsm .
When that invite event comes, we tell dsm to not connect the session
(i.e. reply with 200 and connect audio), but to reply 183 (early
media) and play a file:
/usr/local/lib/sems/dsm/quizconnect/quizconnect_caller.dsm:
-------------------------------------------------------
import(mod_dlg);
initial state START;
transition "got INVITE in caller leg" START - invite -> RUN_INVITE;
apparently no-one tried this, because here we obviously have a c&p typo:
- > initial state RUN_INVITE enter {
+ > state RUN_INVITE enter {
we should only have one initial state ('START').
log(2, "got invite!");
set($connect_session=0);
-- reply with 183 and parse SDP
dlg.acceptInvite(183, Session Progress);
-- set input and output of the session (we have $connect_session=0)
setInOutPlaylist();
-- play some welcome message
sets($prompt_name=$(config.prompt_path)/welcome_caller.wav)
playFile($prompt_name);
};
-------------------------------------------------------
To run this, in sems.conf set application=quizconnect_caller .
so, that's the first part. in the next part, we will see how we can
read callee numbers from mysql DB, create some callee legs, and
interact between caller and callee legs.
now, first we want to handle the error that the file does not exist or
can not be opened. For this, we create a special transition, an
"exception transition". Once an exception is thrown (by some internal
function or a module function), the current sequence of statements is
interrupted, and only exception transitions are executed; all other
transitions are ignored.
quizconnect_caller.dsm:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
transition "error opening file" RUN_INVITE - exception / {
dlg.reply(500, Server Internal Error);
stop(false);
} -> END;
state END;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
using 'stop', we stop execution of this session. stop() or stop(true)
sends a BYE, which we don't want here, and stop(false) just ends the
session after the current event is processed.
Now, a little improvement in the development environment is helpful:
when we update the DSM script, we don't want to have to restart SEMS
every time. So, what we do is we load the xmlrpc2di module
sems.conf:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
load_plugins=wav;session_timer;uac_auth;dsm;monitoring;xmlrpc2di
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
and we tell xmlrpc2di to export the functions from dsm module directly
xmlrpc2di.conf:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
export_di=yes
direct_export=dsm;monitoring
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
then we can in another shell write that few python lines to reload the
quizconnect config:
$ python
Python 2.6.4 (r264:75706, Dec 7 2009, 18:45:15)
[GCC 4.4.1] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from xmlrpclib import *
>>> s = ServerProxy('http://localhost:8090')
>>> s.calls()
0
>>> s.loadConfig('/usr/local/etc/sems/dsm/quizconnect.conf',
'quizconnect')
[200, 'OK']
this way we can replace existing applications (the new set of scripts
are executed for new calls only), and also load other new applications
into the running server.
So, every time we change the DSM scripts, we can simply run
s.loadConfig(...).
The next task should be to get the list of possible destinations
(callees) from the database; we will use a mysql DB. For this, we create
a table in mysql
CREATE TABLE callees (
id int(10) unsigned NOT NULL auto_increment,
caller varchar(128) NOT NULL,
callee varchar(128) NOT NULL,
pin varchar(32) NOT NULL,
PRIMARY KEY (id)
);
and insert some rows:
insert into callees (caller,callee,pin) values ("35","john","12345");
insert into callees (caller,callee,pin) values ("35","anna","54321");
so, if the number '35' will be called, john and anna will be connected,
and john should enter 12345, while anna should enter 54321.
In the script we use the mod_mysql module:
quizconnect_caller.dsm:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
import(mod_mysql);
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
we can set the DB connection in our quizconnect.conf (or pass it to
mysql.connect() action):
quizconnect.conf:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
db_url=mysql://user:p...@localhost/quizconnect
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
btw, as we have seen above with prompt_path, all configuration keys from
our quizconnect.conf are accessible with $config.key, so we could also
write mysql.connect($config.db_url).
With the beginning of processing the call, we connect to the database.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
state RUN_INVITE enter {
log(2, "got invite!");
set($connect_session=0);
myslq.connect();
-- reply with 183 and parse SDP
dlg.acceptInvite(183, Session Progress);
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mysql.connect doesn't throw an exception if the connection fails
('Access denied', 'server has gone away'), instead it sets an error code
($errno) which is the old style of reporting errors. To throw an
exception in that case, we can use throwOnError() and also handle that
exception:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
state RUN_INVITE enter {
log(2, "got invite!");
set($connect_session=0);
mysql.connect();
throwOnError()
-- reply with 183 and parse SDP
dlg.acceptInvite(183, Session Progress);
-- set input and output of the session (we have $connect_session=0)
setInOutPlaylist();
-- play some welcome message
sets($prompt_name=$(config.prompt_path)/welcome_caller.wav)
playFile($prompt_name);
};
transition "error opening file" RUN_INVITE - exception;
test(#type==file) / {
log(0, "error opening file!");
dlg.reply(500, Server Internal Error);
stop(false);
} -> END;
transition "DB error" RUN_INVITE - exception; test(#type==connection) / {
log(0, "error connecting to DB!");
logParams(0);
dlg.reply(500, Server Internal Error);
stop(false);
} -> END;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
When an exception is processed, the parameters (#paramname) are those of
the exception - thus if we do logParams(0), we can see the actual error
from DB in the log.
Now we can select the callees from the database:
set($query_k...@user);
mysql.query(select callee, pin from callees where caller=$query_key);
which should give us $errno and $db.rows.
We will now apply a small trick: We want to process the results of the
DB query, and make some transitions depending on whether that worked or
not. By doing a "repost()", the current event is evaluated once more. so
we can do:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
...
set($query_k...@user);
mysql.query(select callee, pin from callees where caller=$query_key);
repost();
};
transition "query failed" RUN_INVITE - test($errno!="") / {
log(1, "query failed!");
logParams(0);
dlg.reply(500, Server Internal Error);
stop(false);
} -> END;
transition "no results" RUN_INVITE - test($db.rows==0) / {
log(3, "no results");
dlg.reply(404, Not found);
stop(false);
} -> END;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
to handle query error and empty destination set. If we have some
results, we go to a new state CREATE_CALLEE_LEGS:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
transition "we have results" RUN_INVITE - test($db.rows!=0) /
set($callee_counter=0) -> CREATE_CALLEE_LEGS;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
We will actually loop a few times into that state, for every row that we
get from the database - thus we do repost() every time we enter the
state, to make sure we don't stay there (its a 'transitional state'):
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
state CREATE_CALLEE_LEGS
enter {
repost();
};
transition "create one more" CREATE_CALLEE_LEGS -
test($callee_counter<$db.rows) / {
-- this will fill $callee, $pin from current row
mysql.getResult($callee_counter);
set(b_leg_caller=quizconnect);
set(b_leg_callee=$callee);
set(b_leg_domain=sip.domain.net);
set(b_leg_app=quizconnect_callee);
-- pass $pin to other leg
set(b_leg_var.pin=$pin);
dlg.dialout(b_leg);
-- if that worked, we have the ID of the other leg in $b_leg_ltag
log(3, $b_leg_ltag);
First, here a maybe not so obvious fix (but one gets it by reading the
ERROR logs carefully):
if we are looping several times through this, $b_leg_ltag is still
set, so dlg.dialout will try to create another call with the same
local tag, which fails (error message is something like it can not be
added to session container). so we need to add here:
-- reset for new call
clear($b_leg_ltag);
inc(callee_counter);
} -> CREATE_CALLEE_LEGS;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
We use the dlg.dialout function to create an entirely new call, which
will execute the quizconnect_callee application, and will be from
quizconnect to [email protected]. We also pass the pin to the other
leg, this variable can be accessed as $pin in the other script.
When all callee legs are created, we go to a new state. Here we also
handle the BYE in the caller leg, at least we stop our own call:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
transition "done creating callee legs" CREATE_CALLEE_LEGS -
test($callee_counter==$db.rows) -> WAIT_CALLEE;
state WAIT_CALLEE;
transition "BYE received" WAIT_CALLEE - hangup / stop -> END;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
So, that's for the second part of that tutorial. In the third part, we
are hopefully finally going to see how to interact between the call
legs, and how to connect the legs into the same conference. Some hints:
- postEvent() can post events with variables between DSM call legs
- mod_conference is used to join audio of two calls to a conference
But now, if we look at in which state where the caller session
actually is, we will see that after all that it actually is in the
START state. Strange, why does this happen? The reason is that there's
one event run for processing the INVITE message, the 'invite' event,
and then, for the sessionStart event (which is executed because we do
dlg.acceptInvite()) the DSM starts again at the initial state. So we
need to add another transition to go to the right place:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
transition "got session start in caller leg" START - sessionStart ->
WAIT_CALLEE;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
If we try canceling the call, we see that there's another bugfix
needed: "stop(true)" does not work here, because we have not yet
really accepted the call (so bye() won't work) - to the CANCEL we
should reply "487 Request Terminated":
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
transition "CANCEL received" WAIT_CALLEE - hangup / {
dlg.reply(487, Request Terminated);
stop(false);
} -> END;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
But, when the caller hangs up, we need to tell the callee legs to tear
down. So, first we need to save the ltags of the callee legs, (using
some variable names trickery) into $b_ltags[0] .. $b_ltags[n]:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-- if that worked, we have the ID of the other leg in $b_leg_ltag
log(3, $b_leg_ltag);
-- save it
sets($var_name=b_ltags[$(callee_counter)]);
setVar($var_name=$b_leg_ltag);
-- reset for new call
clear($b_leg_ltag);
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In the case that the A leg is canceled, we send an event to the B
legs, looping the same way as we did with creating the calls:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
state WAIT_CALLEE;
transition "CANCEL received" WAIT_CALLEE - hangup / {
dlg.reply(487, Request Terminated);
set($callee_counter=0);
} -> CANCEL_CALLEES;
state CANCEL_CALLEES
enter {
repost();
};
transition "one more to cancel" CANCEL_CALLEES -
test($callee_counter<$db.rows) / {
sets($var_name=b_ltags[$(callee_counter)]);
var(cancel_ltag=$var_name);
set(a_status=CANCEL);
postEvent($cancel_ltag, a_status);
inc(callee_counter);
} -> CANCEL_CALLEES;
transition "canceled all" CANCEL_CALLEES -
test($callee_counter==$db.rows) / stop(false) -> END;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Now it's time to create the script for the callee legs. For the
beginning, this will only play a prompt, and end the call if an event
with a_status==CANCEL is received:
quizconnect_callee.dsm:
--------------------------------------------------------
import(mod_dlg);
initial state START;
transition "got INVITE in callee leg" START - invite -> RUN_INVITE;
transition "session starts in callee leg" START - sessionStart / {
sets($prompt_name=$(config.prompt_path)/welcome_callee.wav)
playFile($prompt_name);
} -> ENTER_PIN;
state RUN_INVITE
enter {
logAll(3);
};
state ENTER_PIN;
transition "got cancel from A leg" ENTER_PIN -
event(#a_status==CANCEL) / stop(true) -> END;
state END;
--------------------------------------------------------
Time to try that out! I am actually replacing the hard-coded outbound
domain with a config variable:
quizconnect_caller.dsm:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
set(b_leg_callee=$callee);
set(b_leg_domain=$config.outbound_domain);
set(b_leg_app=quizconnect_callee);
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
so that I can set the outbound domain in quizconnect.conf:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
db_url=mysql://user:[email protected]/quizconnect
outbound_domain=192.168.5.106:5080
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
and for testing, for the moment I'll start a sipp uas responder:
$ sipp -sn uas -i 192.168.5.106 -mi 192.168.5.106 -p 5080
If I cancel the test call, I can see the two calls in sipp, which were
in after ACK, receive BYEs. Nice!
So, now it would be nice to check what's actually going on with the
calls, in which state they are etc, without always ahving to scroll
through countless log lines. Fortunately, the 'monitoring' module
helps, because if it is loaded, the core saves information about all
running calls to the monitoring in-memory database, and if we enable
two features in
dsm.conf:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
monitoring_full_stategraph=yes
monitoring_full_transitions=yes
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
DSM also saves the states that were visited and the transitions to
monitoring. Lets check it out from the python console over xmlrpc
(that's why we have set direct_export=dsm;monitoring in xmlrpc2di.conf):
-------------------------------------------------------
>>> s.list()
['24ECAEFD-4C72F33D000438F1-B6843B70',
'0FA6BCB2-4C72F33D0004E577-B6843B70',
'59FA4B10-4C72F33D0003C671-B6944B70']
>>> s.get(s.list()[0])
[{'from': '<sip:[email protected]:5080>', 'ruri':
'sip:[email protected]:5080', 'app': 'quizconnect_callee', 'to':
'<sip:[email protected]:5080>', 'dsm_state': 'ENTER_PIN',
'dsm_stategraph': [0, 'quizconnect_callee/START', '> got INVITE in
callee leg >', 'quizconnect_callee/RUN_INVITE',
'quizconnect_callee/START', '> session starts in callee leg >',
'quizconnect_callee/ENTER_PIN'], 'dsm_diag': 'quizconnect_callee',
'dir': 'out'}]
>>> s.get(s.list()[1])
[{'from': '<sip:[email protected]:5080>', 'ruri':
'sip:[email protected]:5080', 'app': 'quizconnect_callee', 'to':
'<sip:[email protected]:5080>', 'dsm_state': 'ENTER_PIN',
'dsm_stategraph': [0, 'quizconnect_callee/START', '> got INVITE in
callee leg >', 'quizconnect_callee/RUN_INVITE',
'quizconnect_callee/START', '> session starts in callee leg >',
'quizconnect_callee/ENTER_PIN'], 'dsm_diag': 'quizconnect_callee',
'dir': 'out'}]
>>> s.get(s.list()[2])
[{'from': '"bee" <sip:[email protected]>', 'ruri':
'sip:[email protected]', 'app': 'quizconnect_caller', 'to':
'<sip:[email protected]>', 'dsm_state': 'WAIT_CALLEE',
'dsm_stategraph': [0, 'quizconnect_caller/START', '> got INVITE in
caller leg >', 'quizconnect_caller/RUN_INVITE', '> we have results >',
'quizconnect_caller/CREATE_CALLEE_LEGS', '> create one more >',
'quizconnect_caller/CREATE_CALLEE_LEGS', '> create one more >',
'quizconnect_caller/CREATE_CALLEE_LEGS', '> done creating callee legs
>', 'quizconnect_caller/WAIT_CALLEE', 'quizconnect_caller/START', '>
got INVITE in caller leg >', 'quizconnect_caller/WAIT_CALLEE'],
'dsm_diag': 'quizconnect_caller', 'dir': 'in'}]
>>>
-------------------------------------------------------
so we see two calls running the quizconnect_callee diagram in
ENTER_PIN state, and one running the quizconnect_caller in WAIT_CALLEE.
two simple scripts are also useful:
$ ./sems-sessions-states.py
calls: 3
call id state
6ABC60BB-4C72F4BF0005C7FD-B6A45B70 WAIT_CALLEE
19D97994-4C72F4BF0006A862-B65D5B70 ENTER_PIN
3EC2A856-4C72F4BF00062B82-B65D5B70 ENTER_PIN
$ ./sems-get-session.py 6ABC60BB-4C72F4BF0005C7FD-B6A45B70
calls: 3
attrib val
from "bee" <sip:[email protected]>
ruri sip:[email protected]
app quizconnect_caller
to <sip:[email protected]>
dsm_state WAIT_CALLEE
dsm_stategraph [0, 'quizconnect_caller/START', '> got INVITE in
caller leg >', 'quizconnect_caller/RUN_INVITE', '> we have results >',
'quizconnect_caller/CREATE_CALLEE_LEGS', '> create one more >',
'quizconnect_caller/CREATE_CALLEE_LEGS', '> create one more >',
'quizconnect_caller/CREATE_CALLEE_LEGS', '> done creating callee legs
>', 'quizconnect_caller/WAIT_CALLEE', 'quizconnect_caller/START', '>
got INVITE in caller leg >', 'quizconnect_caller/WAIT_CALLEE']
dsm_diag quizconnect_caller
dir in
-------------------------------------------------------
$ cat sems-sessions-states.py
#!/usr/bin/python
from xmlrpclib import *
s = ServerProxy("http://127.0.0.1:8090";)
print "calls: %d" % s.calls()
calls_states = s.getAttributeActive("dsm_state")
print "call id state"
for state in calls_states:
print state[0] + " " + state[1]
-------------------------------------------------------
-------------------------------------------------------
$ cat sems-get-session.py
#!/usr/bin/python
import sys
from xmlrpclib import *
if len(sys.argv) != 2:
print "usage: %s <call_id>" % sys.argv[0]
sys.exit(1)
s = ServerProxy("http://127.0.0.1:8090";)
print "calls: %d" % s.calls()
calls_states = s.get(sys.argv[1])
if len(calls_states)==0:
print "call not found"
sys.exit(1)
print "attrib val"
for state in calls_states[0].items():
print str(state[0]).ljust(20) + str(state[1])
-------------------------------------------------------
so, what is next? entering the PIN number, of course. that should be
simple:
quizconnect_callee.dsm:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
state ENTER_PIN;
transition "got cancel from A leg" ENTER_PIN -
event(#a_status==CANCEL) / stop(true) -> END;
transition "pressed a number" ENTER_PIN - key(#key<10) /
append($entered_pin, #key) -> TEST_PIN;
transition "pressed hash or start" ENTER_PIN - key -> TEST_PIN_FINAL;
state TEST_PIN
enter {
repost();
};
transition "pin matches" TEST_PIN - test($pin==$entered_pin) ->
MATCHING_PIN;
transition "pin doesn't match" TEST_PIN - test($pin!=$entered_pin) ->
ENTER_PIN;
state TEST_PIN_FINAL
enter {
repost();
};
transition "pin matches" TEST_PIN_FINAL - test($pin==$entered_pin) ->
MATCHING_PIN;
transition "pin doesn't match" TEST_PIN_FINAL -
test($pin!=$entered_pin) / {
clear($entered_pin);
sets($prompt_name=$(config.prompt_path)/sorry_pin_wrong.wav)
playFile($prompt_name);
} -> ENTER_PIN;
state MATCHING_PIN;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
That works, but we want to break the prompt when the user enters a
key, so we add closePlaylist(false), which stops playback of currently
playing items in the playlist, but doesn't generate an event:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
transition "pressed a number" ENTER_PIN - key(#key<10) / {
closePlaylist(false);
append($entered_pin, #key);
} -> TEST_PIN;
transition "pressed hash or start" ENTER_PIN - key /
closePlaylist(false) -> TEST_PIN_FINAL;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Now I realize we need to pass the id of the caller leg to the callee
leg as well, so we can post back events:
quizconnect_caller.dsm:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-- pass $pin to other leg
set(b_leg_var.pin=$pin);
-- our ltag
set(b_leg_var.a_lt...@local_tag);
dlg.dialout(b_leg);
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
in the MATCHING_PIN state, we let the A leg know that the callee found
the solution, and we connect to the conference room named with the
ltag of the caller leg:
quizconnect_callee.dsm:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
state MATCHING_PIN
enter {
set($b_status=MATCHED);
postEvent($a_ltag, b_status);
conference.join($a_ltag);
repost();
};
transition "ok, connected" MATCHING_PIN --> CONNECTED;
state CONNECTED;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
in the caller leg, we have to do three things if one of the callees
knows the right pin:
1. cancel all the other calls
2. reply to caller with 200 OK
3. join the conference room named with the @local_tag
quizconnect_caller.dsm:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
transition "callee got it" WAIT_CALLEE - test(#b_status==MATCHED) /
set($callee_counter=0) -> CANCEL_OTHER_CALLEES;
state CANCEL_OTHER_CALLEES
enter {
repost();
};
transition "one more to cancel" CANCEL_OTHER_CALLEES -
test($callee_counter<$db.rows) / {
sets($var_name=b_ltags[$(callee_counter)]);
var(cancel_ltag=$var_name);
set(a_status=CANCEL);
postEvent($cancel_ltag, a_status);
inc(callee_counter);
} -> CANCEL_OTHER_CALLEES;
transition "canceled all" CANCEL_OTHER_CALLEES -
test($callee_counter==$db.rows) / {
closePlaylist(false);
dlg.acceptInvite(200, OK);
conference.join(@local_tag);
} -> CONNECTED;
state CONNECTED;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
what's left now is two things only: handling BYE in CONNECTED state
for both sides, and handling CANCEL when the callee leg rings. For the
first one, we need the ltag of the right callee leg, so we'll do this:
quizconnect_callee.dsm:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
state MATCHING_PIN
enter {
set($b_status=MATCHED);
set($b_lt...@local_tag);
postEvent($a_ltag, b_status;b_ltag);
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
and save it:
quizconnect_caller.dsm:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
transition "callee got it" WAIT_CALLEE - test(#b_status==MATCHED) / {
set($b_ltag=#b_ltag);
set($callee_counter=0);
} -> CANCEL_OTHER_CALLEES;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
so we can use it:
quizconnect_caller.dsm:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
state CONNECTED;
transition "BYE received" CONNECTED - hangup / {
set($a_status=BYE);
postEvent($b_ltag, a_status);
stop(false);
} -> END;
transition "BYE in other leg" CONNECTED - event(#b_status==BYE) / {
stop(true);
} -> END;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
and vice versa:
quizconnect_callee.dsm:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
state CONNECTED;
transition "BYE received" CONNECTED - hangup / {
set($b_status=BYE);
postEvent($a_ltag, b_status);
stop(false);
} -> END;
transition "BYE in other leg" CONNECTED - event(#a_status==BYE) / {
stop(true);
} -> END;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
For the second issue, we will simply add the START and RUN_INVITE
states to the "got cancel from A leg" transition:
quizconnect_callee.dsm:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
transition "got cancel from A leg" (START, RUN_INVITE, ENTER_PIN) -
event(#a_status==CANCEL) / stop(true) -> END;
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Attached you find the two scripts, which will (with this mail) be
added soon to git in doc/dsm/tutorials.
Stefan
Attached is the full script that we have so far. I hope you have some
fun trying it out, and I would be happy about some feedback.
Best Regards
Stefan
--
Stefan Sayer
VoIP Services Consulting and Development
Warschauer Str. 24
10243 Berlin
tel:+491621366449
sip:[email protected]
email/xmpp:[email protected]
import(mod_dlg);
import(mod_conference);
initial state START;
transition "got INVITE in callee leg" START - invite -> RUN_INVITE;
transition "session starts in callee leg" START - sessionStart / {
sets($prompt_name=$(config.prompt_path)/welcome_callee.wav)
playFile($prompt_name);
} -> ENTER_PIN;
state RUN_INVITE
enter {
logAll(3);
};
state ENTER_PIN;
transition "got cancel from A leg" (START, RUN_INVITE, ENTER_PIN) -
event(#a_status==CANCEL) / stop(true) -> END;
transition "pressed a number" ENTER_PIN - key(#key<10) / {
closePlaylist(false);
append($entered_pin, #key);
} -> TEST_PIN;
transition "pressed hash or start" ENTER_PIN - key / closePlaylist(false) ->
TEST_PIN_FINAL;
state TEST_PIN
enter {
repost();
};
transition "pin matches" TEST_PIN - test($pin==$entered_pin) -> MATCHING_PIN;
transition "pin doesn't match" TEST_PIN - test($pin!=$entered_pin) -> ENTER_PIN;
state TEST_PIN_FINAL
enter {
repost();
};
transition "pin matches" TEST_PIN_FINAL - test($pin==$entered_pin) ->
MATCHING_PIN;
transition "pin doesn't match" TEST_PIN_FINAL - test($pin!=$entered_pin) / {
clear($entered_pin);
sets($prompt_name=$(config.prompt_path)/sorry_pin_wrong.wav)
playFile($prompt_name);
} -> ENTER_PIN;
state MATCHING_PIN
enter {
set($b_status=MATCHED);
set($b_lt...@local_tag);
postEvent($a_ltag, b_status;b_ltag);
conference.join($a_ltag);
repost();
};
transition "ok, connected" MATCHING_PIN --> CONNECTED;
state CONNECTED;
transition "BYE received" CONNECTED - hangup / {
set($b_status=BYE);
postEvent($a_ltag, b_status);
stop(false);
} -> END;
transition "BYE in other leg" CONNECTED - event(#a_status==BYE) / {
stop(true);
} -> END;
state END;import(mod_dlg);
import(mod_mysql);
import(mod_conference);
initial state START;
transition "got INVITE in caller leg" START - invite -> RUN_INVITE;
transition "got session start in caller leg" START - sessionStart ->
WAIT_CALLEE;
state RUN_INVITE enter {
log(2, "got invite!");
set($connect_session=0);
mysql.connect();
throwOnError()
-- reply with 183 and parse SDP
dlg.acceptInvite(183, Session Progress);
-- set input and output of the session (we have $connect_session=0)
setInOutPlaylist();
-- play some welcome message
sets($prompt_name=$(config.prompt_path)/welcome_caller.wav)
playFile($prompt_name);
set($query_k...@user);
mysql.query(select callee, pin from callees where caller=$query_key);
repost();
};
transition "error opening file" RUN_INVITE - exception; test(#type==file) / {
log(0, "error opening file!");
dlg.reply(500, Server Internal Error);
stop(false);
} -> END;
transition "DB error when connecting" RUN_INVITE - exception;
test(#type==connection) / {
log(0, "error connecting to DB!");
logParams(0);
dlg.reply(500, Server Internal Error);
stop(false);
} -> END;
transition "query failed" RUN_INVITE - test($errno!="") / {
log(1, "query failed!");
logParams(0);
dlg.reply(500, Server Internal Error);
stop(false);
} -> END;
transition "no results" RUN_INVITE - test($db.rows==0) / {
log(3, "no results");
dlg.reply(404, Not found);
stop(false);
} -> END;
transition "we have results" RUN_INVITE - test($db.rows!=0) /
set($callee_counter=0) -> CREATE_CALLEE_LEGS;
state CREATE_CALLEE_LEGS
enter {
repost();
};
transition "create one more" CREATE_CALLEE_LEGS -
test($callee_counter<$db.rows) / {
-- this will fill $callee, $pin from current row
mysql.getResult($callee_counter);
set(b_leg_caller=quizconnect);
set(b_leg_callee=$callee);
set(b_leg_domain=$config.outbound_domain);
set(b_leg_app=quizconnect_callee);
-- pass $pin to other leg
set(b_leg_var.pin=$pin);
-- our ltag
set(b_leg_var.a_lt...@local_tag);
dlg.dialout(b_leg);
-- if that worked, we have the ID of the other leg in $b_leg_ltag
log(3, $b_leg_ltag);
-- save it
sets($var_name=b_ltags[$(callee_counter)]);
setVar($var_name=$b_leg_ltag);
-- reset for new call
clear($b_leg_ltag);
inc(callee_counter);
} -> CREATE_CALLEE_LEGS;
transition "done creating callee legs" CREATE_CALLEE_LEGS -
test($callee_counter==$db.rows) -> WAIT_CALLEE;
state WAIT_CALLEE;
transition "CANCEL received" WAIT_CALLEE - hangup / {
dlg.reply(487, Request Terminated);
set($callee_counter=0);
} -> CANCEL_CALLEES;
state CANCEL_CALLEES
enter {
repost();
};
transition "one more to cancel" CANCEL_CALLEES - test($callee_counter<$db.rows)
/ {
sets($var_name=b_ltags[$(callee_counter)]);
var(cancel_ltag=$var_name);
set(a_status=CANCEL);
postEvent($cancel_ltag, a_status);
inc(callee_counter);
} -> CANCEL_CALLEES;
transition "canceled all" CANCEL_CALLEES - test($callee_counter==$db.rows) /
stop(false) -> END;
transition "callee got it" WAIT_CALLEE - test(#b_status==MATCHED) / {
set($b_ltag=#b_ltag);
set($callee_counter=0);
} -> CANCEL_OTHER_CALLEES;
state CANCEL_OTHER_CALLEES
enter {
repost();
};
transition "one more to cancel" CANCEL_OTHER_CALLEES -
test($callee_counter<$db.rows) / {
sets($var_name=b_ltags[$(callee_counter)]);
var(cancel_ltag=$var_name);
set(a_status=CANCEL);
postEvent($cancel_ltag, a_status);
inc(callee_counter);
} -> CANCEL_OTHER_CALLEES;
transition "canceled all" CANCEL_OTHER_CALLEES -
test($callee_counter==$db.rows) / {
closePlaylist(false);
dlg.acceptInvite(200, OK);
conference.join(@local_tag);
} -> CONNECTED;
state CONNECTED;
transition "BYE received" CONNECTED - hangup / {
set($a_status=BYE);
postEvent($b_ltag, a_status);
stop(false);
} -> END;
transition "BYE in other leg" CONNECTED - event(#b_status==BYE) / {
stop(true);
} -> END;
state END;
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