If we see an RTP packet for a version of the protocol other than version

2, don't try to dissect any of it other than the version field.

Don't try to dissect the RTP data and padding if there's more padding
than data....

svn path=/trunk/; revision=3541

1 files changed, 54 insertions, 10 deletions

diff --git a/packet-rtp.c b/packet-rtp.c
index a182c77c63..61a9e16905 100644
--- a/packet-rtp.c
+++ b/packet-rtp.c
@@ -6,7 +6,7 @@
  * Copyright 2000, Philips Electronics N.V.
  * Written by Andreas Sikkema <andreas.sikkema@philips.com>
  *
- * $Id: packet-rtp.c,v 1.15 2001/06/12 06:31:14 guy Exp $
+ * $Id: packet-rtp.c,v 1.16 2001/06/14 07:05:51 guy Exp $
  *
  * Ethereal - Network traffic analyzer
  * By Gerald Combs <gerald@ethereal.com>
@@ -34,6 +34,20 @@
  * RTP traffic is handled by an even UDP portnumber. This can be any 
  * port number, but there is a registered port available, port 5004
  * See Annex B of ITU-T Recommendation H.225.0, section B.7
+ *
+ * This doesn't dissect older versions of RTP, such as:
+ *
+ *    the vat protocol ("version 0") - see
+ *
+ *	ftp://ftp.ee.lbl.gov/conferencing/vat/alpha-test/vatsrc-4.0b2.tar.gz
+ *
+ *    and look in "session-vat.cc" if you want to write a dissector
+ *    (have fun - there aren't any nice header files showing the packet
+ *    format);
+ *
+ *    version 1, as documented in
+ *
+ *	ftp://gaia.cs.umass.edu/pub/hgschulz/rtp/draft-ietf-avt-rtp-04.txt
  */
 
 
@@ -310,6 +324,7 @@ dissect_rtp( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree )
 	unsigned int i            = 0;
 	unsigned int hdr_extension= 0;
 	unsigned int padding_count= 0;
+	int         data_len, data_reported_len;
 	unsigned int offset = 0;
 	guint16     seq_num;
 	guint32     timestamp;
@@ -323,6 +338,30 @@ dissect_rtp( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree )
 	/* Get the fields in the first octet */
 	octet = tvb_get_guint8( tvb, offset );
 	version = RTP_VERSION( octet );
+
+	if (version != 2) {
+		/*
+		 * Unknown or unsupported version.
+		 */
+		if ( check_col( pinfo->fd, COL_PROTOCOL ) )   {
+			col_set_str( pinfo->fd, COL_PROTOCOL, "RTP" );
+		}
+	
+		if ( check_col( pinfo->fd, COL_INFO) ) {
+			col_add_fstr( pinfo->fd, COL_INFO,
+			    "Unknown RTP version %u", version);
+		}
+
+		if ( tree ) {
+			ti = proto_tree_add_item( tree, proto_rtp, tvb, offset, tvb_length_remaining( tvb, offset ), FALSE );
+			rtp_tree = proto_item_add_subtree( ti, ett_rtp );
+		
+			proto_tree_add_uint( rtp_tree, hf_rtp_version, tvb,
+			    offset, 1, version );
+		}
+		return;
+	}
+
 	padding_set = RTP_PADDING( octet );
 	extension_set = RTP_EXTENSION( octet );
 	csrc_count = RTP_CSRC_COUNT( octet );
@@ -428,15 +467,20 @@ dissect_rtp( tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree )
 		if ( padding_set ) {
 			padding_count = tvb_get_guint8( tvb, tvb_length( tvb ) - 1 );
 			if ( padding_count > 0 ) {
-				dissect_rtp_data( tvb, pinfo, tree, rtp_tree,
-				    offset,
-				    tvb_length( tvb ) - padding_count,
-				    tvb_reported_length( tvb ) - padding_count,
-				    payload_type );
-				offset = tvb_length( tvb ) - padding_count;
-				proto_tree_add_item( rtp_tree, hf_rtp_padding_data, tvb, offset, padding_count - 1, FALSE );
-				offset += padding_count - 1;
-				proto_tree_add_item( rtp_tree, hf_rtp_padding_count, tvb, offset, 1, FALSE );
+				data_len = tvb_length( tvb ) - padding_count;
+				data_reported_len =
+				    tvb_reported_length( tvb ) - padding_count;
+				if (data_len > 0 && data_reported_len > 0) {
+					dissect_rtp_data( tvb, pinfo, tree, rtp_tree,
+					    offset,
+					    data_len,
+					    data_reported_len,
+					    payload_type );
+					offset = tvb_length( tvb ) - padding_count;
+					proto_tree_add_item( rtp_tree, hf_rtp_padding_data, tvb, offset, padding_count - 1, FALSE );
+					offset += padding_count - 1;
+					proto_tree_add_item( rtp_tree, hf_rtp_padding_count, tvb, offset, 1, FALSE );
+				}
 			}
 			else {
 				proto_tree_add_item( rtp_tree, hf_rtp_padding_count, tvb, tvb_length( tvb ) - 1, 1, FALSE );