freetdm: fixing more potential null pointers in native bridge mode.

libs/freetdm/src/ftmod/ftmod_sangoma_ss7/ftmod_sangoma_ss7_main.c

@@ -426,9 +426,15 @@ static void *ftdm_sangoma_ss7_run(ftdm_thread_t * me, void *obj)
 				/* note that the channels being dequeued here may not belong to this span
 				   they may belong to just about any other span that one of our channels
 				   happens to be bridged to */
-				sngss7_chan_data_t *peer_info = peerchan->call_data;
-				sngss7_chan_data_t *chan_info = peer_info->peer_data;
+				sngss7_chan_data_t *peer_info;
+				sngss7_chan_data_t *chan_info;
+
+				peer_info = peerchan->call_data;
+				if (peer_info) {
+					chan_info = peer_info->peer_data;
+					if (chan_info) {
 						ftdmchan = chan_info->ftdmchan;
+						if (ftdmchan) {
 
 							/* 
 							   if there is any state changes at all, those will be done in the opposite channel
@@ -445,6 +451,9 @@ static void *ftdm_sangoma_ss7_run(ftdm_thread_t * me, void *obj)
 
 							ftdm_channel_unlock(ftdmchan);
 						}
+					}
+				}
+			}
 
 			/* clean out all pending stack events */
 			while ((sngss7_event = ftdm_queue_dequeue(sngss7_span->event_queue))) {
@@ -1519,11 +1528,13 @@ ftdm_status_t ftdm_sangoma_ss7_process_state_change (ftdm_channel_t *ftdmchan)
 			 */
 			if (ftdm_test_flag(ftdmchan, FTDM_CHANNEL_OUTBOUND)) {
 				sngss7_chan_data_t *peer_info = sngss7_info->peer_data;
+				if (peer_info) {
 					sngss7_info->peer_data = NULL;
 					if (peer_info) {
 						peer_info->peer_data = NULL;
 					}
 				}
+			}
 
 			/* close the channel */
 			SS7_DEBUG_CHAN(ftdmchan,"FTDM Channel Close %s\n", "");

libs/freetdm/src/ftmod/ftmod_sangoma_ss7/ftmod_sangoma_ss7_out.c

@@ -72,6 +72,7 @@ void ft_to_sngss7_iam (ftdm_channel_t * ftdmchan)
 						var, peer_span->signal_type);
 			} else {
 				peer_info = peer_chan->call_data;
+				if (peer_info) {
 					SS7_INFO_CHAN(ftdmchan,"[CIC:%d]Starting native bridge with peer CIC %d\n", 
 							sngss7_info->circuit->cic, peer_info->circuit->cic);
 
@@ -90,6 +91,7 @@ void ft_to_sngss7_iam (ftdm_channel_t * ftdmchan)
 				}
 			}
 		}
+	}
 
 	if (ftdm_test_flag(ftdmchan, FTDM_CHANNEL_NATIVE_SIGBRIDGE) && sngss7_info->peer_data) {
 		sngss7_span_data_t *span_data = ftdmchan->span->signal_data;