don't explode if a box running CVS head sends trunk frames with timestamps (bug #3790)

git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/v1-0@5202 65c4cc65-6c06-0410-ace0-fbb531ad65f3

CHANGES

@@ -11,6 +11,10 @@ Asterisk 1.0.7
        but has now been fixed.
  -- chan_skinny
     -- A check has been added to avoid a crash.
+ -- chan_iax2
+    -- A feature has been added to CVS head to have the option of sending timestamps with
+       trunk frames.  It is not supported in 1.0, but a change has been made so that it
+       will at least not choke if sent trunk timestamps.
  -- app_voicemail
     -- Some checks have been added to avoid a crash.
  -- speex

channels/chan_iax2.c

@@ -5063,6 +5063,10 @@ static int socket_read(int *id, int fd, short events, void *cbdata)
 		/* This is a meta header */
 		switch(meta->metacmd) {
 		case IAX_META_TRUNK:
+		        if (meta->cmddata != 0) {
+				ast_log(LOG_WARNING, "meta trunk cmd %d received, I only understand 0 (perhaps the remote side is sending trunk timestamps?)\n", meta->cmddata);
+				return 1;
+		        }
 			if (res < sizeof(struct ast_iax2_meta_hdr) + sizeof(struct ast_iax2_meta_trunk_hdr)) {
 				ast_log(LOG_WARNING, "midget meta trunk packet received (%d of %d min)\n", res, (int)sizeof(struct ast_iax2_mini_hdr));
 				return 1;