Merged revisions 218430 via svnmerge from

https://origsvn.digium.com/svn/asterisk/trunk

................
  r218430 | jpeeler | 2009-09-14 17:38:25 -0500 (Mon, 14 Sep 2009) | 18 lines
  
  Merged revisions 218401 via svnmerge from 
  https://origsvn.digium.com/svn/asterisk/branches/1.4
  
  ........
    r218401 | jpeeler | 2009-09-14 16:47:11 -0500 (Mon, 14 Sep 2009) | 11 lines
    
    Fix handling of DAHDI_EVENT_REMOVED event to prevent crash in do_monitor.
    
    After talking to rmudgett about some of his recent iflist locking changes, it
    was determined that the only place that would destroy a channel without being
    explicitly to do so was in handle_init_event. The loop to walk the interface
    list has been modified to wait to destroy the channel until the dahdi_pvt of
    the channel to be destroyed is no longer needed.
    
    (closes issue #15378)
    Reported by: samy
  ........
................


git-svn-id: http://svn.digium.com/svn/asterisk/branches/1.6.0@218431 f38db490-d61c-443f-a65b-d21fe96a405b

1 files changed, 23 insertions, 16 deletions

diff --git a/channels/chan_dahdi.c b/channels/chan_dahdi.c
index 8a2914b49..a140caf20 100644
--- a/channels/chan_dahdi.c
+++ b/channels/chan_dahdi.c
@@ -7891,7 +7891,7 @@ static int dahdi_destroy_channel_bynum(int channel)
 	return RESULT_FAILURE;
 }
 
-static int handle_init_event(struct dahdi_pvt *i, int event)
+static struct dahdi_pvt *handle_init_event(struct dahdi_pvt *i, int event)
 {
 	int res;
 	pthread_t threadid;
@@ -7993,7 +7993,7 @@ static int handle_init_event(struct dahdi_pvt *i, int event)
 			res = tone_zone_play_tone(i->subs[SUB_REAL].dfd, DAHDI_TONE_CONGESTION);
 			if (res < 0)
 					ast_log(LOG_WARNING, "Unable to play congestion tone on channel %d\n", i->channel);
-			return -1;
+			return NULL;
 		}
 		break;
 	case DAHDI_EVENT_NOALARM:
@@ -8058,7 +8058,7 @@ static int handle_init_event(struct dahdi_pvt *i, int event)
 		default:
 			ast_log(LOG_WARNING, "Don't know how to handle on hook with signalling %s on channel %d\n", sig2str(i->sig), i->channel);
 			res = tone_zone_play_tone(i->subs[SUB_REAL].dfd, -1);
-			return -1;
+			return NULL;
 		}
 		break;
 	case DAHDI_EVENT_POLARITY:
@@ -8089,12 +8089,11 @@ static int handle_init_event(struct dahdi_pvt *i, int event)
 				"interface %d\n", i->channel);
 		}
 		break;
-	case DAHDI_EVENT_REMOVED: /* destroy channel */
+	case DAHDI_EVENT_REMOVED: /* destroy channel, will actually do so in do_monitor */
 		ast_log(LOG_NOTICE, 
 				"Got DAHDI_EVENT_REMOVED. Destroying channel %d\n", 
 				i->channel);
-		dahdi_destroy_channel_bynum(i->channel);
-		break;
+		return i;
 	case DAHDI_EVENT_NEONMWI_ACTIVE:
 		if (i->mwimonitor_neon) {
 			notify_message(i->mailbox, 1);
@@ -8108,7 +8107,7 @@ static int handle_init_event(struct dahdi_pvt *i, int event)
 		}
 		break;
 	}
-	return 0;
+	return NULL;
 }
 
 static void *do_monitor(void *data)
@@ -8116,6 +8115,7 @@ static void *do_monitor(void *data)
 	int count, res, res2, spoint, pollres=0;
 	struct dahdi_pvt *i;
 	struct dahdi_pvt *last = NULL;
+	struct dahdi_pvt *doomed;
 	time_t thispass = 0, lastpass = 0;
 	int found;
 	char buf[1024];
@@ -8192,8 +8192,20 @@ static void *do_monitor(void *data)
 		spoint = 0;
 		lastpass = thispass;
 		thispass = time(NULL);
-		i = iflist;
-		while (i) {
+		doomed = NULL;
+		for (i = iflist;; i = i->next) {
+			if (doomed) {
+				int res;
+				res = dahdi_destroy_channel_bynum(doomed->channel);
+				if (!res) {
+					ast_log(LOG_WARNING, "Couldn't find channel to destroy, hopefully another destroy operation just happened.\n");
+				}
+				doomed = NULL;
+			}
+			if (!i) {
+				break;
+			}
+
 			if (thispass != lastpass) {
 				if (!found && ((i == last) || ((i == iflist) && !last))) {
 					last = i;
@@ -8237,10 +8249,9 @@ static void *do_monitor(void *data)
 						ast_debug(1, "Monitor doohicky got event %s on radio channel %d\n", event2str(res), i->channel);
 						/* Don't hold iflock while handling init events */
 						ast_mutex_unlock(&iflock);
-						handle_init_event(i, res);
+						doomed = handle_init_event(i, res);
 						ast_mutex_lock(&iflock);	
 					}
-					i = i->next;
 					continue;
 				}					
 				pollres = ast_fdisset(pfds, i->subs[SUB_REAL].dfd, count, &spoint);
@@ -8250,12 +8261,10 @@ static void *do_monitor(void *data)
 						if (!i->pri)
 #endif						
 							ast_log(LOG_WARNING, "Whoa....  I'm owned but found (%d) in read...\n", i->subs[SUB_REAL].dfd);
-						i = i->next;
 						continue;
 					}
 					if (!i->cidspill && !i->mwimonitor_fsk) {
 						ast_log(LOG_WARNING, "Whoa....  I'm reading but have no cidspill (%d)...\n", i->subs[SUB_REAL].dfd);
-						i = i->next;
 						continue;
 					}
 					res = read(i->subs[SUB_REAL].dfd, buf, sizeof(buf));
@@ -8309,18 +8318,16 @@ static void *do_monitor(void *data)
 						if (!i->pri)
 #endif						
 							ast_log(LOG_WARNING, "Whoa....  I'm owned but found (%d)...\n", i->subs[SUB_REAL].dfd);
-						i = i->next;
 						continue;
 					}
 					res = dahdi_get_event(i->subs[SUB_REAL].dfd);
 					ast_debug(1, "Monitor doohicky got event %s on channel %d\n", event2str(res), i->channel);
 					/* Don't hold iflock while handling init events */
 					ast_mutex_unlock(&iflock);
-					handle_init_event(i, res);
+					doomed = handle_init_event(i, res);
 					ast_mutex_lock(&iflock);	
 				}
 			}
-			i=i->next;
 		}
 		ast_mutex_unlock(&iflock);
 	}