- Instead of only enforcing destination call number checking on an ACK, check

all full frames except for PING and LAGRQ, which may be sent by older versions
  too quickly to contain the destination call number.
  (As suggested by Tim Panton on the asterisk-dev list)
- Merge changes from team/russell/iax2-frame-race, which prevents PING and LAGRQ
  from being sent before the destination call number is known.


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.2@119237 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_iax2.c

@@ -806,15 +806,27 @@ static const struct ast_channel_tech iax2_tech = {
 static int send_ping(void *data)
 {
 	int callno = (long)data;
+	int res = 0;
+
 	/* Ping only if it's real, not if it's bridged */
-	if (iaxs[callno]) {
+
+	ast_mutex_lock(&iaxsl[callno]);
+
+	while (iaxs[callno]) {
+		res = 1;
+		if (!iaxs[callno]->peercallno) {
+			break;
+		}
 #ifdef BRIDGE_OPTIMIZATION
 		if (!iaxs[callno]->bridgecallno)
 #endif
 			send_command(iaxs[callno], AST_FRAME_IAX, IAX_COMMAND_PING, 0, NULL, 0, -1);
-		return 1;
-	} else
-		return 0;
+		break;
+	}
+
+	ast_mutex_unlock(&iaxsl[callno]);
+
+	return res;
 }
 
 static int get_encrypt_methods(const char *s)
@@ -832,15 +844,27 @@ static int get_encrypt_methods(const char *s)
 static int send_lagrq(void *data)
 {
 	int callno = (long)data;
+	int res = 0;
+
 	/* Ping only if it's real not if it's bridged */
-	if (iaxs[callno]) {
+
+	ast_mutex_lock(&iaxsl[callno]);
+
+	while (iaxs[callno]) {
+		res = 1;
+		if (!iaxs[callno]->peercallno) {
+			break;
+		}
 #ifdef BRIDGE_OPTIMIZATION
 		if (!iaxs[callno]->bridgecallno)
 #endif		
 			send_command(iaxs[callno], AST_FRAME_IAX, IAX_COMMAND_LAGRQ, 0, NULL, 0, -1);
-		return 1;
-	} else
-		return 0;
+		break;
+	}
+
+	ast_mutex_unlock(&iaxsl[callno]);
+
+	return res;
 }
 
 static unsigned char compress_subclass(int subclass)
@@ -6814,9 +6838,27 @@ static int socket_read(int *id, int fd, short events, void *cbdata)
 		f.subclass = 0;
 	}
 
-	if (!fr->callno)
-		fr->callno = find_callno(ntohs(mh->callno) & ~IAX_FLAG_FULL, dcallno, &sin, new, 1, fd, 
-			(ntohs(mh->callno) & IAX_FLAG_FULL) && f.frametype == AST_FRAME_IAX && f.subclass == IAX_COMMAND_ACK);
+	if (!fr->callno) {
+		int check_dcallno = 0;
+
+		/*
+		 * We enforce accurate destination call numbers for all full frames except
+		 * LAGRQ and PING commands.  This is because older versions of Asterisk
+		 * schedule these commands to get sent very quickly, and they will sometimes
+		 * be sent before they receive the first frame from the other side.  When
+		 * that happens, it doesn't contain the destination call number.  However,
+		 * not checking it for these frames is safe.
+		 * 
+		 * Discussed in the following thread:
+		 *    http://lists.digium.com/pipermail/asterisk-dev/2008-May/033217.html 
+		 */
+
+		if (ntohs(mh->callno) & IAX_FLAG_FULL) {
+			check_dcallno = f.frametype == AST_FRAME_IAX ? (f.subclass != IAX_COMMAND_PING && f.subclass != IAX_COMMAND_LAGRQ) : 1;
+		}
+
+		fr->callno = find_callno(ntohs(mh->callno) & ~IAX_FLAG_FULL, dcallno, &sin, new, 1, fd, check_dcallno);
+	}
 
 	if (fr->callno > 0) 
 		ast_mutex_lock(&iaxsl[fr->callno]);