DVMRP support, from Ronnie Sahlberg.

Give "packet-igmp.c" an RCS ID.

svn path=/trunk/; revision=3539

1 files changed, 830 insertions, 0 deletions

diff --git a/packet-dvmrp.c b/packet-dvmrp.c
new file mode 100644
index 0000000000..51728ac1c3
--- /dev/null
+++ b/packet-dvmrp.c
@@ -0,0 +1,830 @@
+/* packet-dvmrp.c   2001 Ronnie Sahlberg <rsahlber@bigpond.net.au>
+ * Routines for IGMP/DVMRP packet disassembly
+ *
+ * $Id: packet-dvmrp.c,v 1.1 2001/06/12 06:21:55 guy Exp $
+ *
+ * Ethereal - Network traffic analyzer
+ * By Gerald Combs <gerald@ethereal.com>
+ * 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.
+ */
+/*
+
+
+			DVMRP	DVMRP
+	code		v1	v3
+
+	0x01		*	*
+	0x02		*	*
+	0x03		x
+	0x04		x
+	0x07			x
+	0x08			x
+	0x09			x
+
+
+	* V3 has len>=8 and byte[6]==0xff and byte[7]==0x03
+
+
+	DVMRP is defined in the following RFCs
+	RFC1075 Version 1
+	draft-ietf-idmr-dvmrp-v3-10.txt Version 3
+
+	V1 and V3 can be distinguished by looking at bytes 6 and 7 in the 
+	IGMP/DVMRP header.
+	If header[6]==0xff and header[7]==0x03 we have version 3.
+
+
+	RFC1075 has typos in 3.12.2 and 3.12.4, see if you can spot them.
+*/
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#ifdef HAVE_SYS_TYPES_H
+# include <sys/types.h>
+#endif
+
+#include <stdio.h>
+#include <string.h>
+#include <glib.h>
+
+#include "packet.h"
+#include "ipproto.h"
+#include "in_cksum.h"
+#include "packet-dvmrp.h"
+
+static int proto_dvmrp = -1;
+static int hf_version = -1;
+static int hf_type = -1;
+static int hf_code_v1 = -1;
+static int hf_checksum = -1;
+static int hf_checksum_bad = -1;
+static int hf_commands = -1;
+static int hf_command = -1;
+static int hf_count = -1;
+static int hf_afi = -1;
+static int hf_netmask = -1;
+static int hf_metric = -1;
+static int hf_dest_unr = -1;
+static int hf_split_horiz = -1;
+static int hf_infinity = -1;
+static int hf_daddr = -1;
+static int hf_maddr = -1;
+static int hf_hold = -1;
+static int hf_code_v3 = -1;
+static int hf_capabilities = -1;
+static int hf_cap_leaf = -1;
+static int hf_cap_prune = -1;
+static int hf_cap_genid = -1;
+static int hf_cap_mtrace = -1;
+static int hf_cap_snmp = -1;
+static int hf_cap_netmask = -1;
+static int hf_min_ver = -1;
+static int hf_maj_ver = -1;
+static int hf_genid = -1;
+static int hf_naddr = -1;
+static int hf_route = -1;
+static int hf_saddr = -1;
+static int hf_life = -1;
+static int hf_neighbor = -1;
+
+static int ett_dvmrp = -1;
+static int ett_commands = -1;
+static int ett_capabilities = -1;
+static int ett_route = -1;
+
+
+#define DVMRP_TYPE				0x13
+static const value_string dvmrp_type[] = {
+	{DVMRP_TYPE,	"DVMRP"	},
+	{0,		NULL}
+};
+
+#define DVMRP_V1_RESPONSE			1
+#define DVMRP_V1_REQUEST			2
+#define DVMRP_V1_NON_MEMBERSHIP_REPORT		3
+#define DVMRP_V1_NON_MEMBERSHIP_CANCELLATION	4
+static const value_string code_v1[] = {
+	{DVMRP_V1_RESPONSE,			"Response"			},
+	{DVMRP_V1_REQUEST,			"Request"			},
+	{DVMRP_V1_NON_MEMBERSHIP_REPORT,	"Non-membership report"		},
+	{DVMRP_V1_NON_MEMBERSHIP_CANCELLATION,	"Non-membership cancellation"	},	
+	{0,					NULL}
+};
+
+#define DVMRP_V3_PROBE				1
+#define DVMRP_V3_REPORT				2
+#define DVMRP_V3_PRUNE				7
+#define DVMRP_V3_GRAFT				8
+#define DVMRP_V3_GRAFT_ACK			9
+static const value_string code_v3[] = {
+	{DVMRP_V3_PROBE,	"Probe"},
+	{DVMRP_V3_REPORT,	"Report"},
+	{DVMRP_V3_PRUNE,	"Prune"},
+	{DVMRP_V3_GRAFT,	"Graft"},
+	{DVMRP_V3_GRAFT_ACK,	"Graft ACK"},
+	{0,			NULL}
+};
+
+#define DVMRP_V3_CAP_LEAF	0x01
+#define DVMRP_V3_CAP_PRUNE	0x02
+#define DVMRP_V3_CAP_GENID	0x04
+#define DVMRP_V3_CAP_MTRACE	0x08
+#define DVMRP_V3_CAP_SNMP	0x10
+#define DVMRP_V3_CAP_NETMASK	0x20
+	
+
+#define V1_COMMAND_NULL		0
+#define V1_COMMAND_AFI		2
+#define V1_COMMAND_SUBNETMASK	3
+#define V1_COMMAND_METRIC	4
+#define V1_COMMAND_FLAGS0	5
+#define V1_COMMAND_INFINITY	6
+#define V1_COMMAND_DA		7
+#define V1_COMMAND_RDA		8
+#define V1_COMMAND_NMR		9
+#define V1_COMMAND_NMR_CANCEL	10
+static const value_string command[] = {
+	{V1_COMMAND_NULL,	"NULL"	},
+	{V1_COMMAND_AFI,	"Address Family Indicator"},
+	{V1_COMMAND_SUBNETMASK,	"Subnetmask"},
+	{V1_COMMAND_METRIC,	"Metric"},
+	{V1_COMMAND_FLAGS0,	"Flags0"},
+	{V1_COMMAND_INFINITY,	"Infinity"},
+	{V1_COMMAND_DA,		"Destination Address"},
+	{V1_COMMAND_RDA,	"Requested Destination Address"},
+	{V1_COMMAND_NMR,	"Non-Membership Report"},
+	{V1_COMMAND_NMR_CANCEL,	"Non-Membership Report Cancel"},
+	{0,			NULL}
+};
+
+#define V1_AFI_IP		2
+static const value_string afi[] = {
+	{V1_AFI_IP,	"IP v4 Family"},
+	{0,		NULL}
+};
+
+static const true_false_string tfs_dest_unreach = {
+	"Destination Unreachable",
+	"NOT Destination Unreachable"
+};
+
+static const true_false_string tfs_split_horiz = {
+	"Split Horizon concealed route",
+	"NOT Split Horizon concealed route"
+};
+
+static const true_false_string tfs_cap_leaf = {
+	"Leaf",
+	"NOT Leaf"
+};
+static const true_false_string tfs_cap_prune = {
+	"Prune capable",
+	"NOT Prune capable"
+};
+static const true_false_string tfs_cap_genid = {
+	"Genid capable",
+	"NOT Genid capable"
+};
+static const true_false_string tfs_cap_mtrace = {
+	"Multicast Traceroute capable",
+	"NOT Multicast Traceroute capable"
+};
+static const true_false_string tfs_cap_snmp = {
+	"SNMP capable",
+	"NOT SNMP capable"
+};
+static const true_false_string tfs_cap_netmask = {
+	"Netmask capable",
+	"NOT Netmask capable"
+};
+
+static void dvmrp_checksum(proto_tree *tree,tvbuff_t *tvb, int len)
+{
+	guint16 cksum,hdrcksum;
+	vec_t cksum_vec[1];
+
+	cksum_vec[0].ptr = tvb_get_ptr(tvb, 0, len);
+	cksum_vec[0].len = len;
+
+	hdrcksum = tvb_get_ntohs(tvb, 2);
+	cksum = in_cksum(&cksum_vec[0],1);
+
+	if (cksum==0) {
+		proto_tree_add_uint_format(tree, hf_checksum, tvb, 2, 2, hdrcksum, "Header checksum: 0x%04x (correct)", hdrcksum);
+	} else {
+		proto_tree_add_item_hidden(tree, hf_checksum_bad, tvb, 2, 2, TRUE);
+		proto_tree_add_uint_format(tree, hf_checksum, tvb, 2, 2, hdrcksum, "Header checksum: 0x%04x (incorrect, should be 0x%04x)", hdrcksum,in_cksum_shouldbe(hdrcksum,cksum));
+	}
+
+	return;
+}
+
+
+
+int
+dissect_v3_report(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int offset)
+{
+	guint8 m0,m1,m2,m3;
+	guint8 s0,s1,s2,s3;
+	guint8 metric;
+	guint32 ip;
+
+	while (tvb_length_remaining(tvb, offset)) {
+		proto_tree *tree;
+		proto_item *item;
+		int old_offset = offset;
+
+		item = proto_tree_add_item(parent_tree, hf_route, 
+				tvb, offset, 0, FALSE);
+		tree = proto_item_add_subtree(item, ett_route);
+
+		m0 = 0xff;
+		/* read the mask */
+		m1 = tvb_get_guint8(tvb, offset);
+		m2 = tvb_get_guint8(tvb, offset+1);
+		m3 = tvb_get_guint8(tvb, offset+2);
+
+		ip = m3;
+		ip = (ip<<8)|m2;
+		ip = (ip<<8)|m1;
+		ip = (ip<<8)|m0;
+		proto_tree_add_ipv4(tree, hf_netmask, tvb, offset, 3, ip);
+
+		offset += 3;
+
+		/* read every srcnet, metric  pairs */
+		do {
+			int old_offset = offset;
+			m0 = 0xff;
+
+			s0 = 0;
+			s1 = 0;
+			s2 = 0;
+			s3 = 0;
+
+			s0 = tvb_get_guint8(tvb, offset);
+			offset += 1;
+			if (m1) {
+				s1 = tvb_get_guint8(tvb, offset);
+				offset += 1;
+			}
+			if (m2) {
+				s2 = tvb_get_guint8(tvb, offset);
+				offset += 1;
+			}
+			if (m3) {
+				s3 = tvb_get_guint8(tvb, offset);
+				offset += 1;
+			}
+
+			/* handle special case for default route V3/3.4.3 */
+			if ((!m1)&&(!m2)&&(!m3)&&(!s0)) {
+				m0 = 0;
+			}
+
+			ip = s3;
+			ip = (ip<<8)|s2;
+			ip = (ip<<8)|s1;
+			ip = (ip<<8)|s0;
+			proto_tree_add_ipv4_format(tree, hf_saddr, tvb, 
+				old_offset, offset-old_offset, ip,
+				"%s %d.%d.%d.%d (netmask %d.%d.%d.%d)",
+				m0?"Source Network":"Default Route",
+				s0,s1,s2,s3,m0,m1,m2,m3);
+			
+			metric = tvb_get_guint8(tvb, offset);
+			proto_tree_add_uint(tree, hf_metric, tvb,
+				offset, 1, metric&0x7f);
+			offset += 1;
+
+
+		} while (!(metric&0x80));
+
+		proto_item_set_len(item, offset-old_offset);
+	}
+
+	return offset;
+}
+
+int
+dissect_dvmrp_v3(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int offset)
+{
+	guint8 code,count;
+
+	/* version */
+	proto_tree_add_uint(parent_tree, hf_version, tvb, 0, 0, 3);
+
+	/* type of command */
+	proto_tree_add_uint(parent_tree, hf_type, tvb, offset, 1, 0x13);
+	offset += 1;
+
+	/* code */
+	code = tvb_get_guint8(tvb, offset);
+	proto_tree_add_uint(parent_tree, hf_code_v3, tvb, offset, 1, code);
+	offset += 1;
+	if (check_col(pinfo->fd, COL_INFO)) {
+		col_add_fstr(pinfo->fd, COL_INFO,
+			"V%d %s",3 ,val_to_str(code, code_v3, 
+				"Unknown Type:0x%02x"));
+	}
+
+	/* checksum */
+	dvmrp_checksum(parent_tree, tvb, tvb_length_remaining(tvb, 0));
+	offset += 2;
+
+	/* skip unused byte */
+	offset += 1;
+
+	/* PROBE packets have capabilities flags, unused for other packets */
+	if (code==DVMRP_V3_PROBE) {
+		proto_tree *tree;
+		proto_item *item;
+
+		item = proto_tree_add_item(parent_tree, hf_capabilities, 
+				tvb, offset, 1, FALSE);
+		tree = proto_item_add_subtree(item, ett_capabilities);
+
+		count = tvb_get_guint8(tvb, offset);
+		proto_tree_add_boolean(tree, hf_cap_netmask, tvb, offset, 1, count);
+		proto_tree_add_boolean(tree, hf_cap_snmp, tvb, offset, 1, count);
+		proto_tree_add_boolean(tree, hf_cap_mtrace, tvb, offset, 1, count);
+		proto_tree_add_boolean(tree, hf_cap_genid, tvb, offset, 1, count);
+		proto_tree_add_boolean(tree, hf_cap_prune, tvb, offset, 1, count);
+		proto_tree_add_boolean(tree, hf_cap_leaf, tvb, offset, 1, count);
+	}
+	offset += 1;
+
+	/* minor version */
+	proto_tree_add_uint(parent_tree, hf_min_ver, tvb, offset, 1, tvb_get_guint8(tvb, offset));
+	offset += 1;
+
+	/* major version */
+	proto_tree_add_uint(parent_tree, hf_maj_ver, tvb, offset, 1, tvb_get_guint8(tvb, offset));
+	offset += 1;
+
+	switch (code) {
+	case DVMRP_V3_PROBE:
+		/* generation id */
+		proto_tree_add_uint(parent_tree, hf_genid, tvb, 
+			offset, 4, tvb_get_ntohl(tvb, offset));
+		offset += 4;
+		while (tvb_length_remaining(tvb, offset)) {
+			proto_tree_add_ipv4(parent_tree, hf_neighbor, 
+				tvb, offset, 4, 
+				tvb_get_letohl(tvb, offset));
+			offset += 4;
+		}
+		break;
+	case DVMRP_V3_REPORT:
+		offset = dissect_v3_report(tvb, pinfo, parent_tree, offset);
+		break;
+	case DVMRP_V3_PRUNE:
+		/* source address */
+		proto_tree_add_ipv4(parent_tree, hf_saddr, 
+			tvb, offset, 4, 
+			tvb_get_letohl(tvb, offset));
+		offset += 4;
+		/* group address */
+		proto_tree_add_ipv4(parent_tree, hf_maddr, 
+			tvb, offset, 4, 
+			tvb_get_letohl(tvb, offset));
+		offset += 4;
+		/* prune lifetime */
+		proto_tree_add_uint(parent_tree, hf_life, 
+			tvb, offset, 4, 
+			tvb_get_ntohl(tvb, offset));
+		offset += 4;
+		/* source netmask */
+		if (tvb_length_remaining(tvb, offset)>=4) {
+			proto_tree_add_ipv4(parent_tree, hf_netmask, 
+				tvb, offset, 4, 
+				tvb_get_letohl(tvb, offset));
+			offset += 4;
+		}
+		break;
+	case DVMRP_V3_GRAFT:
+		/* source address */
+		proto_tree_add_ipv4(parent_tree, hf_saddr, 
+			tvb, offset, 4, 
+			tvb_get_letohl(tvb, offset));
+		offset += 4;
+		/* group address */
+		proto_tree_add_ipv4(parent_tree, hf_maddr, 
+			tvb, offset, 4, 
+			tvb_get_letohl(tvb, offset));
+		offset += 4;
+		/* source netmask */
+		if (tvb_length_remaining(tvb, offset)>=4) {
+			proto_tree_add_ipv4(parent_tree, hf_netmask, 
+				tvb, offset, 4, 
+				tvb_get_letohl(tvb, offset));
+			offset += 4;
+		}
+		break;
+	case DVMRP_V3_GRAFT_ACK:
+		/* source address */
+		proto_tree_add_ipv4(parent_tree, hf_saddr, 
+			tvb, offset, 4, 
+			tvb_get_letohl(tvb, offset));
+		offset += 4;
+		/* group address */
+		proto_tree_add_ipv4(parent_tree, hf_maddr, 
+			tvb, offset, 4, 
+			tvb_get_letohl(tvb, offset));
+		offset += 4;
+		/* source netmask */
+		if (tvb_length_remaining(tvb, offset)>=4) {
+			proto_tree_add_ipv4(parent_tree, hf_netmask, 
+				tvb, offset, 4, 
+				tvb_get_letohl(tvb, offset));
+			offset += 4;
+		}
+		break;
+	}
+
+	return offset;
+}
+	
+
+int
+dissect_dvmrp_v1(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int offset)
+{
+	guint8 code;
+	guint8 af=2; /* default */
+
+	/* version */
+	proto_tree_add_uint(parent_tree, hf_version, tvb, 0, 0, 1);
+
+	/* type of command */
+	proto_tree_add_uint(parent_tree, hf_type, tvb, offset, 1, 0x13);
+	offset += 1;
+
+	/* code */
+	code = tvb_get_guint8(tvb, offset);
+	proto_tree_add_uint(parent_tree, hf_code_v1, tvb, offset, 1, code);
+	offset += 1;
+	if (check_col(pinfo->fd, COL_INFO)) {
+		col_add_fstr(pinfo->fd, COL_INFO,
+			"V%d %s",1 ,val_to_str(code, code_v1, 
+				"Unknown Type:0x%02x"));
+	}
+
+	/* checksum */
+	dvmrp_checksum(parent_tree, tvb, tvb_length_remaining(tvb, 0));
+	offset += 2;
+
+	/* decode all the v1 commands */
+	while (tvb_length_remaining(tvb, offset)) {
+		proto_tree *tree;
+		proto_item *item;
+		guint8 cmd,count;
+		int old_offset = offset;
+
+		item = proto_tree_add_item(parent_tree, hf_commands, 
+				tvb, offset, 0, FALSE);
+		tree = proto_item_add_subtree(item, ett_commands);
+
+		cmd = tvb_get_guint8(tvb, offset);
+		proto_tree_add_uint(tree, hf_command, tvb,
+			offset, 1, cmd);
+		offset += 1;
+
+		switch (cmd){
+		case V1_COMMAND_NULL:
+			offset += 1; /* skip ignored/pad byte*/
+			if (item) {
+				proto_item_set_text(item, "Command: NULL");
+			}
+			break;
+		case V1_COMMAND_AFI:
+			af = tvb_get_guint8(tvb, offset);
+			proto_tree_add_uint(tree, hf_afi, tvb,
+				offset, 1, af);
+			offset += 1;
+			if (item) {
+				proto_item_set_text(item, "%s: %s",
+					val_to_str(cmd, command, "Unknown Command:0x%02x"),
+					val_to_str(af, afi, "Unknown Family:0x%02x")
+				);
+			}
+			break;		
+		case V1_COMMAND_SUBNETMASK:
+			count = tvb_get_guint8(tvb, offset);
+			proto_tree_add_uint(tree, hf_count, tvb,
+				offset, 1, count);
+			offset += 1;
+			if (count) { /* must be 0 or 1 */
+				proto_tree_add_ipv4(tree, hf_netmask, 
+					tvb, offset, 4, 
+					tvb_get_letohl(tvb, offset));
+				if (item) {
+					proto_item_set_text(item, "%s: %d.%d.%d.%d",
+						val_to_str(cmd, command, "Unknown Command:0x%02x"), 
+						tvb_get_guint8(tvb, offset),
+						tvb_get_guint8(tvb, offset+1),
+						tvb_get_guint8(tvb, offset+2),
+						tvb_get_guint8(tvb, offset+3));
+				}
+				offset += 4;
+			} else {
+				if (item) {
+					proto_item_set_text(item, "%s: <no mask supplied>",
+						val_to_str(cmd, command, "Unknown Command:0x%02x"));
+				}
+			}
+			break;	
+		case V1_COMMAND_METRIC:
+			proto_tree_add_uint(tree, hf_metric, tvb,
+				offset, 1, tvb_get_guint8(tvb, offset));
+			if (item) {
+				proto_item_set_text(item, "%s: %d",
+					val_to_str(cmd, command, "Unknown Command:0x%02x"), 
+					tvb_get_guint8(tvb, offset));
+			}
+			offset += 1;
+			break;		
+		case V1_COMMAND_FLAGS0:
+			count = tvb_get_guint8(tvb, offset);
+			proto_tree_add_boolean(tree, hf_dest_unr, tvb, offset, 1, count);
+			proto_tree_add_boolean(tree, hf_split_horiz, tvb, offset, 1, count);
+			if (item) {
+				proto_item_set_text(item, "%s: 0x%02x",
+					val_to_str(cmd, command, "Unknown Command:0x%02x"), count);
+			}
+			offset += 1;
+			break;
+		case V1_COMMAND_INFINITY:
+			proto_tree_add_uint(tree, hf_infinity, tvb,
+				offset, 1, tvb_get_guint8(tvb, offset));
+			if (item) {
+				proto_item_set_text(item, "%s: %d",
+					val_to_str(cmd, command, "Unknown Command:0x%02x"), tvb_get_guint8(tvb, offset));
+			}
+			offset += 1;
+			break;		
+		case V1_COMMAND_DA:
+		case V1_COMMAND_RDA: /* same as DA */
+			count = tvb_get_guint8(tvb, offset);
+			proto_tree_add_uint(tree, hf_count, tvb,
+				offset, 1, count);
+			offset += 1;
+			while (count--) {
+				proto_tree_add_ipv4(tree, hf_daddr, 
+					tvb, offset, 4, 
+					tvb_get_letohl(tvb, offset));
+				offset += 4;
+			}
+			if (item) {
+				proto_item_set_text(item, "%s",
+					val_to_str(cmd, command, "Unknown Command:0x%02x"));
+			}
+			break;	
+		case V1_COMMAND_NMR:
+			count = tvb_get_guint8(tvb, offset);
+			proto_tree_add_uint(tree, hf_count, tvb,
+				offset, 1, count);
+			offset += 1;
+			while (count--) {
+				proto_tree_add_ipv4(tree, hf_maddr, 
+					tvb, offset, 4, 
+					tvb_get_letohl(tvb, offset));
+				offset += 4;
+				proto_tree_add_uint(tree, hf_hold, tvb,
+					offset, 4, tvb_get_ntohl(tvb, offset));
+				offset += 4;
+			}
+			if (item) {
+				proto_item_set_text(item, "%s",
+					val_to_str(cmd, command, "Unknown Command:0x%02x"));
+			}
+			break;	
+		case V1_COMMAND_NMR_CANCEL:
+			count = tvb_get_guint8(tvb, offset);
+			proto_tree_add_uint(tree, hf_count, tvb,
+				offset, 1, count);
+			offset += 1;
+			while (count--) {
+				proto_tree_add_ipv4(tree, hf_maddr, 
+					tvb, offset, 4, 
+					tvb_get_letohl(tvb, offset));
+				offset += 4;
+			}
+			if (item) {
+				proto_item_set_text(item, "%s",
+					val_to_str(cmd, command, "Unknown Command:0x%02x"));
+			}
+			break;	
+		}
+
+		proto_item_set_len(item, offset-old_offset);
+	}
+
+	return offset;
+}
+
+/* This function is only called from the IGMP dissector */
+int
+dissect_dvmrp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int offset)
+{
+	proto_tree *tree;
+	proto_item *item;
+
+	if (!proto_is_protocol_enabled(proto_dvmrp)) {
+		/* we are not enabled, skip entire packet to be nice
+		   to the igmp layer. (so clicking on IGMP will display the data)
+		 */
+		return offset+tvb_length_remaining(tvb, offset);
+	}
+
+	item = proto_tree_add_item(parent_tree, proto_dvmrp, tvb, offset, 0, FALSE);
+	tree = proto_item_add_subtree(item, ett_dvmrp);
+
+
+	if (check_col(pinfo->fd, COL_PROTOCOL)) {
+		col_set_str(pinfo->fd, COL_PROTOCOL, "DVMRP");
+	}
+	if (check_col(pinfo->fd, COL_INFO)) {
+		col_clear(pinfo->fd, COL_INFO);
+	}
+
+
+	if ((tvb_length_remaining(tvb, offset)>=8)
+	 && (tvb_get_guint8(tvb, 6)==0xff)
+	 && (tvb_get_guint8(tvb, 7)==0x03)) {
+		offset = dissect_dvmrp_v3(tvb, pinfo, tree, offset);
+		proto_item_set_len(item, offset);
+		return offset;
+	}
+
+	
+	offset = dissect_dvmrp_v1(tvb, pinfo, tree, offset);
+	proto_item_set_len(item, offset);
+	return offset;
+}
+
+void
+proto_register_dvmrp(void)
+{
+	static hf_register_info hf[] = {
+		{ &hf_version,
+			{ "DVMRP Version", "dvmrp.version", FT_UINT8, BASE_DEC,
+			  NULL, 0, "DVMRP Version" }},
+
+		{ &hf_type,
+			{ "Type", "dvmrp.type", FT_UINT8, BASE_HEX,
+			  VALS(dvmrp_type), 0, "DVMRP Packet Type" }},
+
+		{ &hf_code_v1,
+			{ "Code", "dvmrp.v1.code", FT_UINT8, BASE_HEX,
+			  VALS(code_v1), 0, "DVMRP Packet Code" }},
+
+		{ &hf_checksum,
+			{ "Checksum", "dvmrp.checksum", FT_UINT16, BASE_HEX,
+			  NULL, 0, "DVMRP Checksum" }},
+
+		{ &hf_checksum_bad,
+			{ "Bad Checksum", "dvmrp.checksum_bad", FT_BOOLEAN, BASE_NONE,
+			  NULL, 0, "Bad DVMRP Checksum" }},
+
+		{ &hf_commands,
+			{ "Commands", "dvmrp.commands", FT_NONE, BASE_NONE,
+			  NULL, 0, "DVMRP V1 Commands" }},
+
+		{ &hf_command,
+			{ "Command", "dvmrp.command", FT_UINT8, BASE_HEX,
+			  VALS(command), 0, "DVMRP V1 Command" }},
+
+		{ &hf_afi,
+			{ "Address Family", "dvmrp.afi", FT_UINT8, BASE_HEX,
+			  VALS(afi), 0, "DVMRP Address Family Indicator" }},
+
+		{ &hf_count,
+			{ "Count", "dvmrp.count", FT_UINT8, BASE_HEX,
+			  NULL, 0, "Count" }},
+
+		{ &hf_netmask,
+			{ "Netmask", "igmp.netmask", FT_IPv4, BASE_NONE,
+			  NULL, 0, "DVMRP Netmask" }},
+
+		{ &hf_metric,
+			{ "Metric", "dvmrp.metric", FT_UINT8, BASE_DEC,
+			  NULL, 0, "DVMRP Metric" }},
+
+		{&hf_dest_unr,
+			{ "Destination Unreachable", "dvmrp.dest_unreach", FT_BOOLEAN, 8,
+			TFS(&tfs_dest_unreach), 0x01, "Destination Unreachable" }},
+
+		{&hf_split_horiz,
+			{ "Split Horizon", "dvmrp.split_horiz", FT_BOOLEAN, 8,
+			TFS(&tfs_split_horiz), 0x02, "Split Horizon concealed route" }},
+
+		{ &hf_infinity,
+			{ "Infinity", "dvmrp.infinity", FT_UINT8, BASE_DEC,
+			  NULL, 0, "DVMRP Infinity" }},
+
+		{ &hf_daddr,
+			{ "Dest Addr", "igmp.daddr", FT_IPv4, BASE_NONE,
+			  NULL, 0, "DVMRP Destination Address" }},
+
+		{ &hf_maddr,
+			{ "Multicast Addr", "igmp.maddr", FT_IPv4, BASE_NONE,
+			  NULL, 0, "DVMRP Multicast Address" }},
+
+		{ &hf_hold,
+			{ "Hold Time", "dvmrp.hold", FT_UINT32, BASE_DEC,
+			  NULL, 0, "DVMRP Hold Time in seconds" }},
+
+		{ &hf_code_v3,
+			{ "Code", "dvmrp.v3.code", FT_UINT8, BASE_HEX,
+			  VALS(code_v3), 0, "DVMRP Packet Code" }},
+
+		{ &hf_capabilities,
+			{ "Capabilities", "dvmrp.capabilities", FT_NONE, BASE_NONE,
+			  NULL, 0, "DVMRP V3 Capabilities" }},
+
+		{&hf_cap_leaf,
+			{ "Leaf", "dvmrp.cap.leaf", FT_BOOLEAN, 8,
+			TFS(&tfs_cap_leaf), DVMRP_V3_CAP_LEAF, "Leaf" }},
+
+		{&hf_cap_prune,
+			{ "Prune", "dvmrp.cap.prune", FT_BOOLEAN, 8,
+			TFS(&tfs_cap_prune), DVMRP_V3_CAP_PRUNE, "Prune capability" }},
+
+		{&hf_cap_genid,
+			{ "Genid", "dvmrp.cap.genid", FT_BOOLEAN, 8,
+			TFS(&tfs_cap_genid), DVMRP_V3_CAP_GENID, "Genid capability" }},
+
+		{&hf_cap_mtrace,
+			{ "Mtrace", "dvmrp.cap.mtrace", FT_BOOLEAN, 8,
+			TFS(&tfs_cap_mtrace), DVMRP_V3_CAP_MTRACE, "Mtrace capability" }},
+
+		{&hf_cap_snmp,
+			{ "SNMP", "dvmrp.cap.snmp", FT_BOOLEAN, 8,
+			TFS(&tfs_cap_snmp), DVMRP_V3_CAP_SNMP, "SNMP capability" }},
+
+		{&hf_cap_netmask,
+			{ "Netmask", "dvmrp.cap.netmask", FT_BOOLEAN, 8,
+			TFS(&tfs_cap_netmask), DVMRP_V3_CAP_NETMASK, "Netmask capability" }},
+
+		{ &hf_min_ver,
+			{ "Minor Version", "dvmrp.min_ver", FT_UINT8, BASE_HEX,
+			  NULL, 0, "DVMRP Minor Version" }},
+
+		{ &hf_maj_ver,
+			{ "Major Version", "dvmrp.maj_ver", FT_UINT8, BASE_HEX,
+			  NULL, 0, "DVMRP Major Version" }},
+
+		{ &hf_genid,
+			{ "Generation ID", "dvmrp.genid", FT_UINT32, BASE_DEC,
+			  NULL, 0, "DVMRP Generation ID" }},
+
+		{ &hf_naddr,
+			{ "Neighbor Addr", "igmp.naddr", FT_IPv4, BASE_NONE,
+			  NULL, 0, "DVMRP Neighbor Address" }},
+
+		{ &hf_route,
+			{ "Route", "dvmrp.route", FT_NONE, BASE_NONE,
+			  NULL, 0, "DVMRP V3 Route Report" }},
+
+		{ &hf_saddr,
+			{ "Source Addr", "igmp.saddr", FT_IPv4, BASE_NONE,
+			  NULL, 0, "DVMRP Source Address" }},
+
+		{ &hf_life,
+			{ "Prune lifetime", "dvmrp.lifetime", FT_UINT32, BASE_DEC,
+			  NULL, 0, "DVMRP Prune Lifetime" }},
+
+		{ &hf_neighbor,
+			{ "Neighbor Addr", "igmp.neighbor", FT_IPv4, BASE_NONE,
+			  NULL, 0, "DVMRP Neighbor Address" }},
+
+	};
+	static gint *ett[] = {
+		&ett_dvmrp,
+		&ett_commands,
+		&ett_capabilities,
+		&ett_route,
+	};
+
+	proto_dvmrp = proto_register_protocol("Distance Vector Multicast Routing Protocol",
+	    "DVMRP", "dvmrp");
+	proto_register_field_array(proto_dvmrp, hf, array_length(hf));
+	proto_register_subtree_array(ett, array_length(ett));
+}
+