tm: run TMCB_REQUEST_BUILT before sending msg

Althought this was initially documented as being ran before sending the
message out, this callback has been moved *after* the message is sent.
Therefore it can generate some concurrency issues in the dialog, when a
reply is received faster than the outgoing leg would have been updated.

(cherry picked from commit ef680f6)

modules/tm/t_cancel.c

@@ -109,13 +109,19 @@ void cancel_branch( struct cell *t, int branch )
 	 * to deal with it */
 	crb->activ_type=TYPE_LOCAL_CANCEL;
 
+	if ( has_tran_tmcbs( t, TMCB_REQUEST_BUILT) ) {
+		set_extra_tmcb_params( &crb->buffer, &crb->dst);
+		run_trans_callbacks( TMCB_REQUEST_BUILT,
+			t, t->uas.request, 0, 0);
+	}
+
 	LM_DBG("sending cancel...\n");
 	if (t->uac[branch].br_flags & tcp_no_new_conn_bflag)
 		tcp_no_new_conn = 1;
 	if (SEND_BUFFER( crb )==0) {
-		if ( has_tran_tmcbs( t, TMCB_REQUEST_BUILT|TMCB_MSG_SENT_OUT) ) {
+		if ( has_tran_tmcbs( t, TMCB_MSG_SENT_OUT) ) {
 			set_extra_tmcb_params( &crb->buffer, &crb->dst);
-			run_trans_callbacks( TMCB_REQUEST_BUILT|TMCB_MSG_SENT_OUT,
+			run_trans_callbacks( TMCB_MSG_SENT_OUT,
 				t, t->uas.request, 0, 0);
 		}
 	}

modules/tm/t_fwd.c

@@ -794,6 +794,14 @@ int t_forward_nonack( struct cell *t, struct sip_msg* p_msg ,
 			if (t->uac[i].br_flags & tcp_no_new_conn_bflag)
 				tcp_no_new_conn = 1;
 
+			/* successfully sent out -> run callbacks */
+			if ( has_tran_tmcbs( t, TMCB_REQUEST_BUILT) ) {
+				set_extra_tmcb_params( &t->uac[i].request.buffer,
+					&t->uac[i].request.dst);
+				run_trans_callbacks( TMCB_REQUEST_BUILT, t,
+					p_msg, 0, 0);
+			}
+
 			do {
 				if (check_blacklists( t->uac[i].request.dst.proto,
 				&t->uac[i].request.dst.to,
@@ -840,10 +848,10 @@ int t_forward_nonack( struct cell *t, struct sip_msg* p_msg ,
 			set_kr(REQ_FWDED);
 
 			/* successfully sent out -> run callbacks */
-			if ( has_tran_tmcbs( t, TMCB_REQUEST_BUILT|TMCB_MSG_SENT_OUT) ) {
+			if ( has_tran_tmcbs( t, TMCB_MSG_SENT_OUT) ) {
 				set_extra_tmcb_params( &t->uac[i].request.buffer,
 					&t->uac[i].request.dst);
-				run_trans_callbacks( TMCB_REQUEST_BUILT|TMCB_MSG_SENT_OUT, t,
+				run_trans_callbacks( TMCB_MSG_SENT_OUT, t,
 					p_msg, 0, 0);
 			}
 

modules/tm/t_hooks.h

@@ -166,6 +166,9 @@ struct cell;
  *  It may be a request (out request, out CANCEL, out ACK) or a
  *  reply (relaied reply, locally generated reply).
  *
+ * TMCB_REQUEST_BUILT -- triggered just before a message has been built and
+ *  is about to be sent out.
+ *
  * IMPORTANT NOTES:
  *
  * 1) that callbacks MUST be installed before forking