Andreas Sikkema's new H.261 and TPKT dissectors, replacement RTCP and

RTP dissectors, and changes to the Q.931 dissector for use with H.323.

svn path=/trunk/; revision=2511

1 files changed, 187 insertions, 0 deletions

diff --git a/packet-tpkt.c b/packet-tpkt.c
new file mode 100644
index 0000000000..fb71911573
--- /dev/null
+++ b/packet-tpkt.c
@@ -0,0 +1,187 @@
+/* packet-tpkt.c
+ *
+ * Routines for TPKT dissection
+ * Copyright 2000, Philips Electronics N.V.
+ * Andreas Sikkema <andreas.sikkema@philips.com>
+ *
+ * Ethereal - Network traffic analyzer
+ * By Gerald Combs <gerald@zing.org>
+ * Copyright 1998 Gerald Combs
+ *
+ * 
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+/*
+ * This dissector tries to dissect the TPKT protocol according to
+ * RFC 1006
+ *
+ * IMPORTANT IMPORTANT IMPORTANT IMPORTANT IMPORTANT IMPORTANT IMPORTANT 
+ *
+ * Please examine the dissector. It is NOT defined in the normal way!
+ * Some variables are references and the dissector also returns a 
+ * value! And no, this is not a heuristic dissector!
+ * 
+ * IMPORTANT IMPORTANT IMPORTANT IMPORTANT IMPORTANT IMPORTANT IMPORTANT 
+ */
+
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <glib.h>
+#include "packet.h"
+
+#ifdef HAVE_SYS_TYPES_H
+#  include <sys/types.h>
+#endif
+
+#ifdef HAVE_NETINET_IN_H
+#  include <netinet/in.h>
+#endif
+
+#include <stdio.h>
+#include <string.h>
+
+#include "packet-tpkt.h"
+
+/* TPKT header fields             */
+static int proto_tpkt          = -1;
+static int hf_tpkt_version     = -1;
+static int hf_tpkt_reserved    = -1;
+static int hf_tpkt_length      = -1;
+
+/* TPKT fields defining a sub tree */
+static gint ett_tpkt           = -1;
+
+int 
+is_tpkt( tvbuff_t *tvb, unsigned int* offset )
+{
+	if ( (*offset) + 4 > tvb_length( tvb ) ) return FALSE;
+	if ( ! ( ( tvb_get_guint8( tvb, ( *offset ) ) == 3 ) && 
+		       ( tvb_get_guint8( tvb, ( *offset ) + 1 ) == 0 ) ) ) return FALSE;
+
+  return TRUE;
+}
+
+int
+dissect_tpkt( tvbuff_t *tvb, unsigned int* offset, packet_info *pinfo, proto_tree *tree )
+{
+	proto_item *ti            = NULL;
+	proto_tree *tpkt_tree     = NULL;
+	unsigned int data_len = 0;
+
+
+	pinfo->current_proto = "TPKT";
+
+	/* There should at least be 4 bytes left in the frame */
+	if ( (*offset) + 4 > tvb_length( tvb ) ) return -1;
+	/* 
+	 * The first octet should be 3 and the second one should be 0 
+	 * The H.323 implementers guide suggests that this migh not 
+	 * always be the case....
+	 */
+	if ( ! ( ( tvb_get_guint8( tvb, ( *offset ) ) == 3 ) && 
+		       ( tvb_get_guint8( tvb, ( *offset ) + 1 ) == 0 ) ) ) return -1;
+
+	if ( check_col( pinfo->fd, COL_PROTOCOL ) ) {
+		col_add_str( pinfo->fd, COL_PROTOCOL, "TPKT" );
+	}
+	
+	if ( check_col( pinfo->fd, COL_INFO) ) {
+		/*data_len = pntohs( &pd[ (*offset) + 2 ] );*/
+		data_len = tvb_get_ntohs( tvb, (*offset) + 2 );
+
+		col_add_fstr( pinfo->fd, COL_INFO, "TPKT Data length = %d", data_len );
+	}
+
+	if ( tree ) {
+		ti = proto_tree_add_item( tree, proto_tpkt, tvb, (*offset), 4, FALSE );
+		tpkt_tree = proto_item_add_subtree( ti, ett_tpkt );
+		/* Version 1st octet */
+		proto_tree_add_item( tpkt_tree, hf_tpkt_version, tvb, (*offset), 1, FALSE );
+		(*offset)++;
+		/* Reserved octet*/
+		proto_tree_add_item( tpkt_tree, hf_tpkt_reserved, tvb, (*offset), 1, FALSE );
+		(*offset)++;
+	}
+	else {
+		(*offset) += 2;
+	}
+	/* Length, two octets */
+	/*data_len = pntohs( &pd[ (*offset) ] );*/
+	data_len = tvb_get_ntohs( tvb, (*offset) );
+
+	if ( tree )
+		proto_tree_add_uint_format( tpkt_tree, hf_tpkt_length, tvb, (*offset), 2, data_len, "Length: %d", data_len );
+
+	(*offset) += 2;
+	return data_len;
+}
+
+void
+proto_register_tpkt(void)
+{
+	static hf_register_info hf[] = 
+	{
+		{ 
+			&hf_tpkt_version,
+			{ 
+				"Version", 
+				"tpkt.version", 
+				FT_UINT8, 
+				BASE_DEC, 
+				NULL, 
+				0x0,
+				"" 
+			}
+		},
+		{ 
+			&hf_tpkt_reserved,
+			{ 
+				"Reserved", 
+				"tpkt.reserved", 
+				FT_UINT8, 
+				BASE_DEC, 
+				NULL, 
+				0x0,
+				"" 
+			}
+		},
+		{ 
+			&hf_tpkt_length,
+			{ 
+				"Length", 
+				"tpkt.length", 
+				FT_UINT16, 
+				BASE_DEC, 
+				NULL, 
+				0x0,
+				"" 
+			}
+		},
+};
+	
+	static gint *ett[] = 
+	{
+		&ett_tpkt,
+	};
+
+
+	proto_tpkt = proto_register_protocol("TPKT", "tpkt");
+	proto_register_field_array(proto_tpkt, hf, array_length(hf));
+	proto_register_subtree_array(ett, array_length(ett));
+}