You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
kamailio/modules/tm/t_suspend.c

315 lines
8.6 KiB

/*
* $Id$
*
* Copyright (C) 2008 iptelorg GmbH
*
* This file is part of ser, a free SIP server.
*
* ser is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version
*
* For a license to use the ser software under conditions
* other than those described here, or to purchase support for this
* software, please contact iptel.org by e-mail at the following addresses:
* info@iptel.org
*
* ser is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* History:
* --------
* 2008-11-10 Initial version (Miklos)
* 2009-06-01 Pre- and post-script callbacks of failure route are executed (Miklos)
*
*/
#include "../../action.h"
#include "../../script_cb.h"
#include "config.h"
#include "sip_msg.h"
#include "t_reply.h"
#include "h_table.h"
#include "t_lookup.h"
#include "t_fwd.h"
#include "t_funcs.h"
#include "timer.h"
#include "t_suspend.h"
/* Suspends the transaction for later use.
* Save the returned hash_index and label to get
* back to the SIP request processing, see the readme.
*
* Return value:
* 0 - success
* <0 - failure
*/
int t_suspend(struct sip_msg *msg,
unsigned int *hash_index, unsigned int *label)
{
struct cell *t;
t = get_t();
if (!t || t == T_UNDEFINED) {
LOG(L_ERR, "ERROR: t_suspend: " \
"transaction has not been created yet\n");
return -1;
}
if (t->flags & T_CANCELED) {
/* The transaction has already been canceled */
LOG(L_DBG, "DEBUG: t_suspend: " \
"trying to suspend an already canceled transaction\n");
ser_error = E_CANCELED;
return 1;
}
/* send a 100 Trying reply, because the INVITE processing
will probably take a long time */
if (msg->REQ_METHOD==METHOD_INVITE && (t->flags&T_AUTO_INV_100)
&& (t->uas.status < 100)
) {
if (!t_reply( t, msg , 100 ,
cfg_get(tm, tm_cfg, tm_auto_inv_100_r)))
DBG("SER: ERROR: t_suspend (100)\n");
}
if ((t->nr_of_outgoings==0) && /* if there had already been
an UAC created, then the lumps were
saved as well */
save_msg_lumps(t->uas.request, msg)
) {
LOG(L_ERR, "ERROR: t_suspend: " \
"failed to save the message lumps\n");
return -1;
}
/* save the message flags */
t->uas.request->flags = msg->flags;
*hash_index = t->hash_index;
*label = t->label;
/* add a bling UAC to let the fr timer running */
if (add_blind_uac() < 0) {
LOG(L_ERR, "ERROR: t_suspend: " \
"failed to add the blind UAC\n");
return -1;
}
return 0;
}
/* Continues the SIP request processing previously saved by
* t_suspend(). The script does not continue from the same
* point, but a separate route block is executed instead.
*
* Return value:
* 0 - success
* <0 - failure
*/
int t_continue(unsigned int hash_index, unsigned int label,
struct action *route)
{
struct cell *t;
struct sip_msg faked_req;
int branch;
struct ua_client *uac =NULL;
int ret;
if (t_lookup_ident(&t, hash_index, label) < 0) {
LOG(L_ERR, "ERROR: t_continue: transaction not found\n");
return -1;
}
if (t->flags & T_CANCELED) {
/* The transaction has already been canceled,
* needless to continue */
UNREF(t); /* t_unref would kill the transaction */
/* reset T as we have no working T anymore */
set_t(T_UNDEFINED, T_BR_UNDEFINED);
return 1;
}
/* The transaction has to be locked to protect it
* form calling t_continue() multiple times simultaneously */
LOCK_REPLIES(t);
/* Try to find the blind UAC, and cancel its fr timer.
* We assume that the last blind uac called t_continue(). */
for ( branch = t->nr_of_outgoings-1;
branch >= 0 && t->uac[branch].request.buffer;
branch--);
if (branch >= 0) {
stop_rb_timers(&t->uac[branch].request);
if (t->uac[branch].last_received != 0) {
/* Either t_continue() has already been
* called or the branch has already timed out.
* Needless to continue. */
UNLOCK_REPLIES(t);
UNREF(t); /* t_unref would kill the transaction */
return 1;
}
/* Set last_received to something >= 200,
* the actual value does not matter, the branch
* will never be picked up for response forwarding.
* If last_received is lower than 200,
* then the branch may tried to be cancelled later,
* for example when t_reply() is called from
* a failure route => deadlock, because both
* of them need the reply lock to be held. */
t->uac[branch].last_received=500;
uac = &t->uac[branch];
}
/* else
Not a huge problem, fr timer will fire, but CANCEL
will not be sent. last_received will be set to 408. */
reset_kr();
/* fake the request and the environment, like in failure_route */
if (!fake_req(&faked_req, t->uas.request, 0 /* extra flags */, uac)) {
LOG(L_ERR, "ERROR: t_continue: fake_req failed\n");
ret = -1;
goto kill_trans;
}
faked_env( t, &faked_req);
/* The sip msg is a faked msg just like in failure route
* therefore execute the pre- and post-script callbacks
* of failure route (Miklos)
*/
if (exec_pre_script_cb(&faked_req, FAILURE_CB_TYPE)>0) {
if (run_top_route(route, &faked_req, 0)<0)
LOG(L_ERR, "ERROR: t_continue: Error in run_top_route\n");
exec_post_script_cb(&faked_req, FAILURE_CB_TYPE);
}
/* TODO: save_msg_lumps should clone the lumps to shm mem */
/* restore original environment and free the fake msg */
faked_env( t, 0);
free_faked_req(&faked_req, t);
/* update the flags */
t->uas.request->flags = faked_req.flags;
if (t->uas.status < 200) {
/* No final reply has been sent yet.
* Check whether or not there is any pending branch.
*/
for ( branch = 0;
branch < t->nr_of_outgoings;
branch++
) {
if (t->uac[branch].last_received < 200)
break;
}
if (branch == t->nr_of_outgoings) {
/* There is not any open branch so there is
* no chance that a final response will be received. */
ret = 0;
goto kill_trans;
}
}
UNLOCK_REPLIES(t);
/* unref the transaction */
t_unref(t->uas.request);
return 0;
kill_trans:
/* The script has hopefully set the error code. If not,
* let us reply with a default error. */
if ((kill_transaction_unsafe(t,
tm_error ? tm_error : E_UNSPEC)) <=0
) {
LOG(L_ERR, "ERROR: t_continue: "
"reply generation failed\n");
/* The transaction must be explicitely released,
* no more timer is running */
UNLOCK_REPLIES(t);
t_release_transaction(t);
} else {
UNLOCK_REPLIES(t);
}
t_unref(t->uas.request);
return ret;
}
/* Revoke the suspension of the SIP request, i.e.
* cancel the fr timer of the blind uac.
* This function can be called when something fails
* after t_suspend() has already been executed in the same
* process, and it turns out that the transaction should
* not have been suspended.
*
* Return value:
* 0 - success
* <0 - failure
*/
int t_cancel_suspend(unsigned int hash_index, unsigned int label)
{
struct cell *t;
int branch;
t = get_t();
if (!t || t == T_UNDEFINED) {
LOG(L_ERR, "ERROR: t_revoke_suspend: " \
"no active transaction\n");
return -1;
}
/* Only to double-check the IDs */
if ((t->hash_index != hash_index)
|| (t->label != label)
) {
LOG(L_ERR, "ERROR: t_revoke_suspend: " \
"transaction id mismatch\n");
return -1;
}
/* The transaction does not need to be locked because this
* function is either executed from the original route block
* or from failure route which already locks */
reset_kr(); /* the blind UAC of t_suspend has set kr */
/* Try to find the blind UAC, and cancel its fr timer.
* We assume that the last blind uac called this function. */
for ( branch = t->nr_of_outgoings-1;
branch >= 0 && t->uac[branch].request.buffer;
branch--);
if (branch >= 0) {
stop_rb_timers(&t->uac[branch].request);
/* Set last_received to something >= 200,
* the actual value does not matter, the branch
* will never be picked up for response forwarding.
* If last_received is lower than 200,
* then the branch may tried to be cancelled later,
* for example when t_reply() is called from
* a failure rute => deadlock, because both
* of them need the reply lock to be held. */
t->uac[branch].last_received=500;
} else {
/* Not a huge problem, fr timer will fire, but CANCEL
will not be sent. last_received will be set to 408. */
return -1;
}
return 0;
}