dissect_rtp_heur: prevent a 'false positive' when trying stun dissection.

Specifically: when dissect_rtp_heur calls the stun dissector:
- Don't do a 'data' dissection if stun dissection fails;
  (ie: use call_dissector_only instead of call_dissector).
- return the stun dissector success/fail status to the caller of dissect_rtp_heur;
  (Done by registering and calling the heuristic version of the stun dissector).
Also: use call_dissector_only for each of the dissectors called by dissect_rtp_heur
 (altho it really makes no difference at this point except for the call to the
  stun dissector).


git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@27443 f5534014-38df-0310-8fa8-9805f1628bb7

1 files changed, 6 insertions, 4 deletions

diff --git a/epan/dissectors/packet-rtp.c b/epan/dissectors/packet-rtp.c
index 2036a96078..355b6638d3 100644
--- a/epan/dissectors/packet-rtp.c
+++ b/epan/dissectors/packet-rtp.c
@@ -135,6 +135,7 @@ static const fragment_items rtp_fragment_items = {
 
 static dissector_handle_t rtp_handle;
 static dissector_handle_t stun_handle;
+static dissector_handle_t stun_heur_handle;
 static dissector_handle_t t38_handle;
 static dissector_handle_t zrtp_handle;
 
@@ -481,16 +482,16 @@ dissect_rtp_heur( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree )
 	if (version == 0) {
 		if (!(tvb_memeql(tvb, 4, "ZRTP", 4)))
 		{
-			call_dissector(zrtp_handle, tvb, pinfo, tree);
+			call_dissector_only(zrtp_handle, tvb, pinfo, tree);
 			return TRUE;
 		} else {
 			switch (global_rtp_version0_type) {
 			case RTP0_STUN:
-				call_dissector(stun_handle, tvb, pinfo, tree);
-				return TRUE;
+				return call_dissector_only(stun_heur_handle, tvb, pinfo, tree);
 				
 			case RTP0_T38:
-				call_dissector(t38_handle, tvb, pinfo, tree);
+				/* XXX: Should really be calling a heuristic dissector for T38 ??? */
+				call_dissector_only(t38_handle, tvb, pinfo, tree);
 				return TRUE;
 				
 			case RTP0_INVALID:
@@ -1951,6 +1952,7 @@ proto_reg_handoff_rtp(void)
 
 		data_handle = find_dissector("data");
 		stun_handle = find_dissector("stun");
+		stun_heur_handle = find_dissector("stun-heur");
 		t38_handle = find_dissector("t38");
 		zrtp_handle = find_dissector("zrtp");