/* 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;
}
if(t->async_backup.backup_route != TM_ONREPLY_ROUTE){
/* 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;
}
}else{
branch = t->async_backup.backup_branch;
LOG(L_DBG,"DEBUG: t_cancel_suspend_reply: This is a cancel suspend for a response\n");
t->uac[branch].reply->msg_flags &= ~FL_RPL_SUSPENDED;
if (t->uas.request) t->uas.request->msg_flags&= ~FL_RPL_SUSPENDED;
}
return 0;
}
/* returns 1 if everything was OK or -1 for error
*/
int t_release_transaction( struct cell *trans )
{
set_kr(REQ_RLSD);
stop_rb_timers(&trans->uas.response);
cleanup_uac_timers( trans );
put_on_wait( trans );
return 1;
}
/* should be called directly only if one of the condition bellow is true:
* - prepare_cancel_branch or prepare_to_cancel returned true for this branch
* - buffer value was 0 and then set to BUSY in an atomic op.:
* if (atomic_cmpxchg_long(&buffer, 0, BUSY_BUFFER)==0).
*
* params: t - transaction
* branch - branch number to be canceled
* reason - cancel reason structure
* flags - howto cancel:
* F_CANCEL_B_KILL - will completely stop the
* branch (stops the timers), use with care
* F_CANCEL_B_FAKE_REPLY - will send a fake 487
* to all branches that haven't received any response
* (>=100). It assumes the REPLY_LOCK is not held
* (if it is => deadlock)
* F_CANCEL_B_FORCE_C - will send a cancel (and create the
* corresp. local cancel rb) even if no reply was
* received; F_CANCEL_B_FAKE_REPLY will be ignored.
* F_CANCEL_B_FORCE_RETR - don't stop retransmission if no
* reply was received on the branch; incompatible
* with F_CANCEL_B_FAKE_REPLY, F_CANCEL_B_FORCE_C and
* F_CANCEL_B_KILL (all of them take precedence) a
* default: stop only the retransmissions for the branch
* and leave it to timeout if it doesn't receive any
* response to the CANCEL
* returns: 0 - branch inactive after running cancel_branch()
* 1 - branch still active (fr_timer)
* -1 - error
* WARNING:
* - F_CANCEL_B_KILL should be used only if the transaction is killed
* explicitly afterwards (since it might kill all the timers
* the transaction won't be able to "kill" itself => if not
* explicitly "put_on_wait" it might live forever)
* - F_CANCEL_B_FAKE_REPLY must be used only if the REPLY_LOCK is not
* held
* - checking for buffer==0 under REPLY_LOCK is no enough, an
* atomic_cmpxhcg or atomic_get_and_set _must_ be used.
*/
int cancel_branch( struct cell *t, int branch,
#ifdef CANCEL_REASON_SUPPORT
struct cancel_reason* reason,
#endif /* CANCEL_REASON_SUPPORT */
int flags )
{
char *cancel;
unsigned int len;
struct retr_buf *crb, *irb;
int ret;
struct cancel_info tmp_cd;
void* pcbuf;
crb=&t->uac[branch].local_cancel;
irb=&t->uac[branch].request;
irb->flags|=F_RB_CANCELED;
ret=1;
init_cancel_info(&tmp_cd);
# ifdef EXTRA_DEBUG
if (crb->buffer!=BUSY_BUFFER) {
LOG(L_CRIT, "ERROR: attempt to rewrite cancel buffer: %p\n",
crb->buffer);
abort();
}
# endif
if (flags & F_CANCEL_B_KILL){
stop_rb_timers( irb );
ret=0;
if ((t->uac[branch].last_received < 100) &&
!(flags & F_CANCEL_B_FORCE_C)) {
DBG("DEBUG: cancel_branch: no response ever received: "
"giving up on cancel\n");
/* remove BUSY_BUFFER -- mark cancel buffer as not used */
pcbuf=&crb->buffer; /* workaround for type punning warnings */
atomic_set_long(pcbuf, 0);
/* try to relay auto-generated 487 canceling response only when
* another one is not under relaying on the branch and there is
* no forced response per transaction from script */
if((flags & F_CANCEL_B_FAKE_REPLY)
&& !(irb->flags&F_RB_RELAYREPLY)
&& !(t->flags&T_ADMIN_REPLY)) {
LOCK_REPLIES(t);
if (relay_reply(t, FAKED_REPLY, branch, 487, &tmp_cd, 1) ==
RPS_ERROR){
return -1;
}
}
/* do nothing, hope that the caller will clean up */
return ret;
}
}else{
if (t->uac[branch].last_received < 100){
if (!(flags & F_CANCEL_B_FORCE_C)) {
/* no response received => don't send a cancel on this branch,
* just drop it */
if (!(flags & F_CANCEL_B_FORCE_RETR))
stop_rb_retr(irb); /* stop retransmissions */
/* remove BUSY_BUFFER -- mark cancel buffer as not used */
pcbuf=&crb->buffer; /* workaround for type punning warnings */
atomic_set_long(pcbuf, 0);
if (flags & F_CANCEL_B_FAKE_REPLY){
stop_rb_timers( irb ); /* stop even the fr timer */
LOCK_REPLIES(t);
if (relay_reply(t, FAKED_REPLY, branch, 487, &tmp_cd, 1)==
RPS_ERROR){
return -1;
}
return 0; /* should be inactive after the 487 */
}
/* do nothing, just wait for the final timeout */
return 1;
}
}
stop_rb_retr(irb); /* stop retransmissions */
}
if (cfg_get(tm, tm_cfg, reparse_invite) ||
(t->uas.request && t->uas.request->msg_flags&(FL_USE_UAC_FROM|FL_USE_UAC_TO))) {
/* build the CANCEL from the INVITE which was sent out */
cancel = build_local_reparse(t, branch, &len, CANCEL, CANCEL_LEN,
(t->uas.request && t->uas.request->msg_flags&FL_USE_UAC_TO)?0:&t->to
#ifdef CANCEL_REASON_SUPPORT
, reason
#endif /* CANCEL_REASON_SUPPORT */
);
} else {
/* build the CANCEL from the received INVITE */
cancel = build_local(t, branch, &len, CANCEL, CANCEL_LEN, &t->to
#ifdef CANCEL_REASON_SUPPORT
, reason
#endif /* CANCEL_REASON_SUPPORT */
);
}
if (!cancel) {
LOG(L_ERR, "ERROR: attempt to build a CANCEL failed\n");
/* remove BUSY_BUFFER -- mark cancel buffer as not used */
pcbuf=&crb->buffer; /* workaround for type punning warnings */
atomic_set_long(pcbuf, 0);
return -1;
}
/* install cancel now */
crb->dst = irb->dst;
crb->branch = branch;
/* label it as cancel so that FR timer can better know how to
deal with it */
crb->activ_type = TYPE_LOCAL_CANCEL;
/* be extra carefully and check for bugs (the below if could be replaced
* by an atomic_set((void*)&crb->buffer, cancel) */
if (unlikely(atomic_cmpxchg_long((void*)&crb->buffer, (long)BUSY_BUFFER,
(long)cancel)!= (long)BUSY_BUFFER)){
BUG("tm: cancel_branch: local_cancel buffer=%p != BUSY_BUFFER"
" (trying to continue)\n", crb->buffer);
shm_free(cancel);
return -1;
}
membar_write_atomic_op(); /* cancel retr. can be called from
reply_received w/o the reply lock held =>
they check for buffer_len to
see if a valid reply exists */
crb->buffer_len = len;
DBG("DEBUG: cancel_branch: sending cancel...\n");
if (SEND_BUFFER( crb )>=0){
if (unlikely (has_tran_tmcbs(t, TMCB_REQUEST_OUT)))
run_trans_callbacks_with_buf(TMCB_REQUEST_OUT, crb, t->uas.request, 0, TMCB_LOCAL_F);
if (unlikely (has_tran_tmcbs(t, TMCB_REQUEST_SENT)))
run_trans_callbacks_with_buf(TMCB_REQUEST_SENT, crb, t->uas.request, 0, TMCB_LOCAL_F);
}
/*sets and starts the FINAL RESPONSE timer */
if (start_retr( crb )!=0)
LOG(L_CRIT, "BUG: cancel_branch: failed to start retransmission"
" for %p\n", crb);
return ret;
}
/* 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;
struct cancel_info cancel_data;
int branch;
struct ua_client *uac =NULL;
int ret;
int cb_type;
int msg_status;
int last_uac_status;
int reply_status;
int do_put_on_wait;
struct hdr_field *hdr, *prev = 0, *tmp = 0;
if (t_lookup_ident(&t, hash_index, label) < 0) {
LM_ERR("transaction not found\n");
return -1;
}
if (!(t->flags & T_ASYNC_SUSPENDED)) {
LM_WARN("transaction is not suspended [%u:%u]\n", hash_index, label);
return -2;
}
if (t->flags & T_CANCELED) {
t->flags &= ~T_ASYNC_SUSPENDED;
/* 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_ASYNC_CONTINUE(t);
t->flags |= T_ASYNC_CONTINUE; /* we can now know anywhere in kamailio
* that we are executing post a suspend */
/* which route block type were we in when we were suspended */
cb_type = FAILURE_CB_TYPE;;
switch (t->async_backup.backup_route) {
case REQUEST_ROUTE:
cb_type = FAILURE_CB_TYPE;
break;
case FAILURE_ROUTE:
cb_type = FAILURE_CB_TYPE;
break;
case TM_ONREPLY_ROUTE:
cb_type = ONREPLY_CB_TYPE;
break;
case BRANCH_ROUTE:
cb_type = FAILURE_CB_TYPE;
break;
}
if(t->async_backup.backup_route != TM_ONREPLY_ROUTE){
branch = t->async_backup.blind_uac; /* get the branch of the blind UAC setup
* during suspend */
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. */
t->flags &= ~T_ASYNC_SUSPENDED;
UNLOCK_ASYNC_CONTINUE(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. */
/* We should not reset kr here to 0 as it's quite possible before continuing the dev. has correctly set the
* kr by, for example, sending a transactional reply in code - resetting here will cause a dirty log message
* "WARNING: script writer didn't release transaction" to appear in log files. TODO: maybe we need to add
* a special kr for async?
* reset_kr();
*/
/* fake the request and the environment, like in failure_route */
if (!fake_req(&faked_req, t->uas.request, 0 /* extra flags */, uac)) {
LM_ERR("building fake_req failed\n");
ret = -1;
goto kill_trans;
}
faked_env( t, &faked_req, 1);
/* execute the pre/post -script callbacks based on original route block */
if (exec_pre_script_cb(&faked_req, cb_type)>0) {
if (run_top_route(route, &faked_req, 0)<0)
LM_ERR("failure inside run_top_route\n");
exec_post_script_cb(&faked_req, 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, 1);
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;
}
}
} else {
branch = t->async_backup.backup_branch;
init_cancel_info(&cancel_data);
LM_DBG("continuing from a suspended reply"
" - resetting the suspend branch flag\n");
if (t->uac[branch].reply) {
t->uac[branch].reply->msg_flags &= ~FL_RPL_SUSPENDED;
} else {
LM_WARN("no reply in t_continue for branch. not much we can do\n");
return 0;
}
if (t->uas.request) t->uas.request->msg_flags&= ~FL_RPL_SUSPENDED;
faked_env( t, t->uac[branch].reply, 1);
if (exec_pre_script_cb(t->uac[branch].reply, cb_type)>0) {
if (run_top_route(route, t->uac[branch].reply, 0)<0){
LOG(L_ERR, "ERROR: t_continue_reply: Error in run_top_route\n");
}
exec_post_script_cb(t->uac[branch].reply, cb_type);
}
LM_DBG("restoring previous environment");
faked_env( t, 0, 1);
/*lock transaction replies - will be unlocked when reply is relayed*/
LOCK_REPLIES( t );
if ( is_local(t) ) {
LM_DBG("t is local - sending reply with status code: [%d]\n",
t->uac[branch].reply->first_line.u.reply.statuscode);
reply_status = local_reply( t, t->uac[branch].reply, branch,
t->uac[branch].reply->first_line.u.reply.statuscode,
&cancel_data );
if (reply_status == RPS_COMPLETED) {
/* no more UAC FR/RETR (if I received a 2xx, there may
* be still pending branches ...
*/
cleanup_uac_timers( t );
if (is_invite(t)) cancel_uacs(t, &cancel_data, F_CANCEL_B_KILL);
/* There is no need to call set_final_timer because we know
* that the transaction is local */
put_on_wait(t);
}else if (unlikely(cancel_data.cancel_bitmap)){
/* cancel everything, even non-INVITEs (e.g in case of 6xx), use
* cancel_b_method for canceling unreplied branches */
cancel_uacs(t, &cancel_data, cfg_get(tm,tm_cfg, cancel_b_flags));
}
} else {
LM_DBG("t is not local - relaying reply with status code: [%d]\n",
t->uac[branch].reply->first_line.u.reply.statuscode);
do_put_on_wait = 0;
if(t->uac[branch].reply->first_line.u.reply.statuscode>=200){
do_put_on_wait = 1;
}
reply_status=relay_reply( t, t->uac[branch].reply, branch,
t->uac[branch].reply->first_line.u.reply.statuscode,
&cancel_data, do_put_on_wait );
if (reply_status == RPS_COMPLETED) {
/* no more UAC FR/RETR (if I received a 2xx, there may
be still pending branches ...
*/
cleanup_uac_timers( t );
/* 2xx is a special case: we can have a COMPLETED request
* with branches still open => we have to cancel them */
if (is_invite(t) && cancel_data.cancel_bitmap)
cancel_uacs( t, &cancel_data, F_CANCEL_B_KILL);
/* FR for negative INVITES, WAIT anything else */
/* Call to set_final_timer is embedded in relay_reply to avoid
* race conditions when reply is sent out and an ACK to stop
* retransmissions comes before retransmission timer is set.*/
}else if (unlikely(cancel_data.cancel_bitmap)){
/* cancel everything, even non-INVITEs (e.g in case of 6xx), use
* cancel_b_method for canceling unreplied branches */
cancel_uacs(t, &cancel_data, cfg_get(tm,tm_cfg, cancel_b_flags));
}
}
t->uac[branch].request.flags|=F_RB_REPLIED;
if (reply_status==RPS_ERROR){
goto done;
}
/* update FR/RETR timers on provisional replies */
msg_status=t->uac[branch].reply->REPLY_STATUS;
last_uac_status=t->uac[branch].last_received;
if (is_invite(t) && msg_status<200 &&
( cfg_get(tm, tm_cfg, restart_fr_on_each_reply) ||
( (last_uac_status<msg_status) &&
((msg_status>=180) || (last_uac_status==0)) )
) ) { /* provisional now */
restart_rb_fr(& t->uac[branch].request, t->fr_inv_timeout);
t->uac[branch].request.flags|=F_RB_FR_INV; /* mark fr_inv */
}
}
done:
UNLOCK_ASYNC_CONTINUE(t);
if(t->async_backup.backup_route != TM_ONREPLY_ROUTE){
/* unref the transaction */
t_unref(t->uas.request);
} else {
tm_ctx_set_branch_index(T_BR_UNDEFINED);
/* unref the transaction */
t_unref(t->uac[branch].reply);
LOG(L_DBG,"DEBUG: t_continue_reply: Freeing earlier cloned reply\n");
/* free lumps that were added during reply processing */
del_nonshm_lump( &(t->uac[branch].reply->add_rm) );
del_nonshm_lump( &(t->uac[branch].reply->body_lumps) );
del_nonshm_lump_rpl( &(t->uac[branch].reply->reply_lump) );
/* free header's parsed structures that were added */
for( hdr=t->uac[branch].reply->headers ; hdr ; hdr=hdr->next ) {
if ( hdr->parsed && hdr_allocs_parse(hdr) &&
(hdr->parsed<(void*)t->uac[branch].reply ||
hdr->parsed>=(void*)t->uac[branch].end_reply)) {
clean_hdr_field(hdr);
hdr->parsed = 0;
}
}
/* now go through hdr_fields themselves and remove the pkg allocated space */
hdr = t->uac[branch].reply->headers;
while (hdr) {
if ( hdr && ((void*)hdr<(void*)t->uac[branch].reply ||
(void*)hdr>=(void*)t->uac[branch].end_reply)) {
//this header needs to be freed and removed form the list.
if (!prev) {
t->uac[branch].reply->headers = hdr->next;
} else {
prev->next = hdr->next;
}
tmp = hdr;
hdr = hdr->next;
pkg_free(tmp);
} else {
prev = hdr;
hdr = hdr->next;
}
}
sip_msg_free(t->uac[branch].reply);
t->uac[branch].reply = 0;
}
/*This transaction is no longer suspended so unsetting the SUSPEND flag*/
t->flags &= ~T_ASYNC_SUSPENDED;
return 0;
kill_trans:
t->flags &= ~T_ASYNC_SUSPENDED;
/* 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_ASYNC_CONTINUE(t);
t_release_transaction(t);
} else {
UNLOCK_ASYNC_CONTINUE(t);
}
if(t->async_backup.backup_route != TM_ONREPLY_ROUTE){
t_unref(t->uas.request);
} else {
/* unref the transaction */
t_unref(t->uac[branch].reply);
}
return ret;
}
