path: root/epan/dissectors/packet-vtp.c

/* packet-vtp.c
 * Routines for the disassembly of Cisco's VLAN Trunking Protocol
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

#include "config.h"

#include <epan/packet.h>
#include <epan/expert.h>
#include <epan/cisco_pid.h>

/*
 * See
 *
 *	http://www.cisco.com/en/US/tech/tk389/tk689/technologies_tech_note09186a0080094c52.shtml
 *
 * for some information on VTP.
 */
void proto_register_vtp(void);
void proto_reg_handoff_vtp(void);

static dissector_handle_t vtp_handle;

static int proto_vtp = -1;
static int hf_vtp_version = -1;
static int hf_vtp_code = -1;
static int hf_vtp_followers = -1;
static int hf_vtp_md_len = -1;
static int hf_vtp_md = -1;
static int hf_vtp_conf_rev_num = -1;
static int hf_vtp_upd_id = -1;
static int hf_vtp_upd_ts = -1;
static int hf_vtp_md5_digest = -1;
static int hf_vtp_seq_num = -1;
static int hf_vtp_start_value = -1;
static int hf_vtp_vlan_info_len = -1;
static int hf_vtp_vlan_status = -1;
static int hf_vtp_vlan_status_vlan_susp = -1;
static int hf_vtp_vlan_type = -1;
static int hf_vtp_vlan_name_len = -1;
static int hf_vtp_isl_vlan_id = -1;
static int hf_vtp_mtu_size = -1;
static int hf_vtp_802_10_index = -1;
static int hf_vtp_vlan_name = -1;
static int hf_vtp_vlan_tlvtype = -1;
static int hf_vtp_vlan_tlvlength = -1;
static int hf_vtp_pruning_first_vid = -1;
static int hf_vtp_pruning_last_vid = -1;
static int hf_vtp_pruning_active_vid = -1;
static int hf_vtp_vlan_src_route_ring_num = -1;
static int hf_vtp_vlan_src_route_bridge_num = -1;
static int hf_vtp_vlan_stp_type = -1;
static int hf_vtp_vlan_parent_vlan = -1;
static int hf_vtp_vlan_translationally_bridged_vlans = -1;
static int hf_vtp_vlan_pruning = -1;
static int hf_vtp_vlan_bridge_type = -1;
static int hf_vtp_vlan_max_are_hop_count = -1;
static int hf_vtp_vlan_max_ste_hop_count = -1;
static int hf_vtp_vlan_backup_crf_mode = -1;
static int hf_vtp_vlan_data = -1;
static int hf_vtp_reserved = -1;

static gint ett_vtp = -1;
static gint ett_vtp_vlan_info = -1;
static gint ett_vtp_vlan_status = -1;
static gint ett_vtp_tlv = -1;
static gint ett_vtp_pruning = -1;

static expert_field ei_vtp_vlan_tlvlength_bad = EI_INIT;

static int
dissect_vlan_info(tvbuff_t *tvb, packet_info *pinfo, int offset, proto_tree *tree);
static void
dissect_vlan_info_tlv(tvbuff_t *tvb, packet_info *pinfo, int offset, int length,
		      proto_tree *tree, proto_item *ti, guint8 type);

#define SUMMARY_ADVERT		0x01
#define SUBSET_ADVERT		0x02
#define ADVERT_REQUEST		0x03
#define JOIN_MSG		0x04

static const value_string type_vals[] = {
	{ SUMMARY_ADVERT, "Summary Advertisement" },
	{ SUBSET_ADVERT,  "Subset Advertisement" },
	{ ADVERT_REQUEST, "Advertisement Request" },
	{ JOIN_MSG,       "Join/Prune Message" },
	{ 0,              NULL },
};

static void
set_vtp_info_col(tvbuff_t *tvb, packet_info *pinfo)
{
	switch (tvb_get_guint8(tvb, 1)) {

	case SUMMARY_ADVERT:
		col_add_fstr(pinfo->cinfo, COL_INFO,
		    "Summary Advertisement, Revision: %u", tvb_get_ntohl(tvb, 36));

		if (tvb_get_guint8(tvb, 2) > 0) {
			col_append_fstr(pinfo->cinfo, COL_INFO,
			    ", Followers: %u", tvb_get_guint8(tvb, 2));
		}

		break;

	case SUBSET_ADVERT:
		col_add_fstr(pinfo->cinfo, COL_INFO,
		    "Subset Advertisement, Revision: %u, Seq: %u",
		    tvb_get_ntohl(tvb, 36), tvb_get_guint8(tvb, 2));
		break;

	case ADVERT_REQUEST:
		col_set_str(pinfo->cinfo, COL_INFO, "Advertisement Request");
		break;

	case JOIN_MSG:
		col_set_str(pinfo->cinfo, COL_INFO, "Join");
		break;

	default:
		col_set_str(pinfo->cinfo, COL_INFO, "Unrecognized VTP message");
		break;
	}
}

static int
dissect_vtp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
{
	proto_item *ti;
	proto_tree *vtp_tree = NULL, *vtp_pruning_tree = NULL;
	int offset = 0;
	guint8 code;
	guint8 *upd_timestamp;
	int vlan_info_len;
	int pruning_vlan_id;
	int yy, mm, dd, hh, _mm, ss;
	char *display;

	col_set_str(pinfo->cinfo, COL_PROTOCOL, "VTP");
	set_vtp_info_col(tvb, pinfo);

	ti = proto_tree_add_item(tree, proto_vtp, tvb, offset, -1, ENC_NA);
	vtp_tree = proto_item_add_subtree(ti, ett_vtp);

	proto_tree_add_item(vtp_tree, hf_vtp_version, tvb, offset, 1, ENC_BIG_ENDIAN);
	offset += 1;

	code = tvb_get_guint8(tvb, offset);
	proto_tree_add_item(vtp_tree, hf_vtp_code, tvb, offset, 1, ENC_BIG_ENDIAN);
	offset += 1;

	switch (code) {

	case SUMMARY_ADVERT:
		proto_tree_add_item(vtp_tree, hf_vtp_followers, tvb, offset, 1, ENC_BIG_ENDIAN);
		offset += 1;

		proto_tree_add_item(vtp_tree, hf_vtp_md_len, tvb, offset, 1, ENC_BIG_ENDIAN);
		offset += 1;

		proto_tree_add_item(vtp_tree, hf_vtp_md, tvb, offset, 32, ENC_ASCII);
		offset += 32;

		proto_tree_add_item(vtp_tree, hf_vtp_conf_rev_num, tvb, offset, 4, ENC_BIG_ENDIAN);
		offset += 4;

		proto_tree_add_item(vtp_tree, hf_vtp_upd_id, tvb, offset, 4, ENC_BIG_ENDIAN);
		offset += 4;

		upd_timestamp = display = tvb_get_string_enc(pinfo->pool, tvb, offset, 12, ENC_ASCII);
		if (sscanf(upd_timestamp, "%2d%2d%2d%2d%2d%2d", &yy, &mm, &dd, &hh, &_mm, &ss) == 6) {
			display = wmem_strdup_printf(pinfo->pool, "%02d-%02d-%02d %02d:%02d:%02d",
									yy, mm, dd, hh, _mm, ss);
		}
		proto_tree_add_string_format_value(vtp_tree, hf_vtp_upd_ts, tvb,
			offset, 12, upd_timestamp, "%s", display);
		offset += 12;

		proto_tree_add_item(vtp_tree, hf_vtp_md5_digest, tvb, offset, 16, ENC_NA);
		break;

	case SUBSET_ADVERT:
		proto_tree_add_item(vtp_tree, hf_vtp_seq_num, tvb, offset, 1, ENC_BIG_ENDIAN);
		offset += 1;

		proto_tree_add_item(vtp_tree, hf_vtp_md_len, tvb, offset, 1, ENC_BIG_ENDIAN);
		offset += 1;

		proto_tree_add_item(vtp_tree, hf_vtp_md, tvb, offset, 32, ENC_ASCII);
		offset += 32;

		proto_tree_add_item(vtp_tree, hf_vtp_conf_rev_num, tvb, offset, 4, ENC_BIG_ENDIAN);
		offset += 4;

		while (tvb_reported_length_remaining(tvb, offset) > 0) {
			vlan_info_len =
				dissect_vlan_info(tvb, pinfo, offset, vtp_tree);
			if (vlan_info_len <= 0)
				break;
			offset += vlan_info_len;
		}
		break;

	case ADVERT_REQUEST:
		proto_tree_add_item(vtp_tree, hf_vtp_reserved, tvb, offset, 1, ENC_NA);
		offset += 1;

		proto_tree_add_item(vtp_tree, hf_vtp_md_len, tvb, offset, 1, ENC_BIG_ENDIAN);
		offset += 1;

		proto_tree_add_item(vtp_tree, hf_vtp_md, tvb, offset, 32, ENC_ASCII);
		offset += 32;

		proto_tree_add_item(vtp_tree, hf_vtp_start_value, tvb, offset, 2, ENC_BIG_ENDIAN);
		break;

	case JOIN_MSG:
		proto_tree_add_item(vtp_tree, hf_vtp_reserved, tvb, offset, 1, ENC_NA);
		offset += 1;

		proto_tree_add_item(vtp_tree, hf_vtp_md_len, tvb, offset, 1, ENC_BIG_ENDIAN);
		offset += 1;

		proto_tree_add_item(vtp_tree, hf_vtp_md, tvb, offset, 32, ENC_ASCII);
		offset += 32;

		proto_tree_add_item(vtp_tree, hf_vtp_pruning_first_vid, tvb, offset, 2, ENC_BIG_ENDIAN);
		pruning_vlan_id = tvb_get_ntohs(tvb, offset);
		offset += 2;

		proto_tree_add_item(vtp_tree, hf_vtp_pruning_last_vid, tvb, offset,
			2, ENC_BIG_ENDIAN);
		offset += 2;

		vtp_pruning_tree = proto_tree_add_subtree(vtp_tree, tvb, offset, -1,
			ett_vtp_pruning, NULL, "Advertised active (i.e. not pruned) VLANs");

		while (tvb_reported_length_remaining(tvb, offset) > 0) {
			guint8 vlan_usage_bitmap;
			int shift;

			vlan_usage_bitmap = tvb_get_guint8(tvb, offset);

			for (shift = 0; shift < 8; shift++) {
				if (vlan_usage_bitmap & (1<<7)) {
					proto_tree_add_uint(vtp_pruning_tree, hf_vtp_pruning_active_vid,
					tvb, offset, 1, pruning_vlan_id);
				}

				pruning_vlan_id += 1;
				vlan_usage_bitmap <<= 1;
			}

			offset += 1;
		}

		break;
	}
	return tvb_captured_length(tvb);
}

#define	VLAN_SUSPENDED	0x01

static const value_string vlan_type_vals[] = {
	{ 0x01, "Ethernet" },
	{ 0x02, "FDDI" },
	{ 0x03, "TrCRF" },
	{ 0x04, "FDDI-net" },
	{ 0x05, "TrBRF" },
	{ 0,    NULL },
};

#define	SR_RING_NUM		0x01
#define	SR_BRIDGE_NUM		0x02
#define	STP_TYPE		0x03
#define	PARENT_VLAN		0x04
#define	TR_BRIDGED_VLANS	0x05
#define	PRUNING			0x06
#define	BRIDGE_TYPE		0x07
#define	MAX_ARE_HOP_CNT		0x08
#define	MAX_STE_HOP_CNT		0x09
#define	BACKUP_CRF_MODE		0x0A

static const value_string vlan_tlv_type_vals[] = {
	{ SR_RING_NUM,      "Source-Routing Ring Number" },
	{ SR_BRIDGE_NUM,    "Source-Routing Bridge Number" },
	{ STP_TYPE,         "Spanning-Tree Protocol Type" },
	{ PARENT_VLAN,      "Parent VLAN" },
	{ TR_BRIDGED_VLANS, "Translationally Bridged VLANs" },
	{ PRUNING,          "Pruning" },
	{ BRIDGE_TYPE,      "Bridge Type" },
	{ MAX_ARE_HOP_CNT,  "Max ARE Hop Count" },
	{ MAX_STE_HOP_CNT,  "Max STE Hop Count" },
	{ BACKUP_CRF_MODE,  "Backup CRF Mode" },
	{ 0,                NULL },
};

static int
dissect_vlan_info(tvbuff_t *tvb, packet_info *pinfo, int offset, proto_tree *tree)
{
	proto_item *ti;
	proto_tree *vlan_info_tree;
	proto_tree *status_tree;
	guint8 vlan_info_len;
	int vlan_info_left;
	guint8 status;
	guint8 vlan_name_len;
	guint8 type;
	int length;
	proto_tree *tlv_tree;

	vlan_info_len = tvb_get_guint8(tvb, offset);
	vlan_info_tree = proto_tree_add_subtree(tree, tvb, offset, vlan_info_len,
	    ett_vtp_vlan_info, NULL, "VLAN Information");
	vlan_info_left = vlan_info_len;

	proto_tree_add_uint(vlan_info_tree, hf_vtp_vlan_info_len, tvb, offset, 1,
	    vlan_info_len);
	offset += 1;
	vlan_info_left -= 1;

	status = tvb_get_guint8(tvb, offset);
	ti = proto_tree_add_uint(vlan_info_tree, hf_vtp_vlan_status, tvb, offset, 1, status);
	if (status & VLAN_SUSPENDED)
	    proto_item_append_text(ti, " (VLAN suspended)");
	status_tree = proto_item_add_subtree(ti, ett_vtp_vlan_status);
	proto_tree_add_boolean(status_tree, hf_vtp_vlan_status_vlan_susp, tvb, offset, 1,
	    status);
	offset += 1;
	vlan_info_left -= 1;

	proto_tree_add_item(vlan_info_tree, hf_vtp_vlan_type, tvb, offset, 1, ENC_BIG_ENDIAN);
	offset += 1;
	vlan_info_left -= 1;

	vlan_name_len = tvb_get_guint8(tvb, offset);
	proto_tree_add_item(vlan_info_tree, hf_vtp_vlan_name_len, tvb, offset, 1, ENC_BIG_ENDIAN);
	offset += 1;
	vlan_info_left -= 1;

	proto_tree_add_item(vlan_info_tree, hf_vtp_isl_vlan_id, tvb, offset, 2, ENC_BIG_ENDIAN);
	offset += 2;
	vlan_info_left -= 2;

	proto_tree_add_item(vlan_info_tree, hf_vtp_mtu_size, tvb, offset, 2, ENC_BIG_ENDIAN);
	offset += 2;
	vlan_info_left -= 2;

	proto_tree_add_item(vlan_info_tree, hf_vtp_802_10_index, tvb, offset, 4, ENC_BIG_ENDIAN);
	offset += 4;
	vlan_info_left -= 4;

	/* VLAN name length appears to be rounded up to a multiple of 4. */
	vlan_name_len = 4*((vlan_name_len + 3)/4);
	proto_tree_add_item(vlan_info_tree, hf_vtp_vlan_name, tvb, offset, vlan_name_len, ENC_ASCII);
	offset += vlan_name_len;
	vlan_info_left -= vlan_name_len;

	while (vlan_info_left > 0) {
		type = tvb_get_guint8(tvb, offset + 0);
		length = tvb_get_guint8(tvb, offset + 1);

		tlv_tree = proto_tree_add_subtree(vlan_info_tree, tvb, offset,
		    2 + length*2, ett_vtp_tlv, &ti,
		    val_to_str(type, vlan_tlv_type_vals,
		      "Unknown TLV type: 0x%02x"));
		proto_tree_add_item(tlv_tree, hf_vtp_vlan_tlvtype, tvb, offset, 1, ENC_BIG_ENDIAN);
		proto_tree_add_item(tlv_tree, hf_vtp_vlan_tlvlength, tvb, offset+1, 1, ENC_BIG_ENDIAN);
		offset += 2;
		vlan_info_left -= 2;
		if (length > 0) {
			dissect_vlan_info_tlv(tvb, pinfo, offset, length*2, tlv_tree,
			    ti, type);
		}
		offset += length*2;
		vlan_info_left -= length*2;
	}

	return vlan_info_len;
}

static const value_string stp_type_vals[] = {
	{ 1, "SRT" },
	{ 2, "SRB" },
	{ 3, "Auto" },
	{ 0, NULL },
};

static const value_string pruning_vals[] = {
	{ 1, "Enabled" },
	{ 2, "Disabled" },
	{ 0, NULL },
};

static const value_string bridge_type_vals[] = {
	{ 1, "SRT" },
	{ 2, "SRB" },
	{ 0, NULL },
};

static const value_string backup_crf_mode_vals[] = {
	{ 1, "TrCRF is configured as a backup" },
	{ 2, "TrCRF is not configured as a backup" },
	{ 0, NULL },
};

static void
dissect_vlan_info_tlv(tvbuff_t *tvb, packet_info *pinfo, int offset, int length,
		      proto_tree *tree, proto_item *ti, guint8 type)
{
	switch (type) {

	case SR_RING_NUM:
		if (length == 2) {
			proto_tree_add_item(tree, hf_vtp_vlan_src_route_ring_num, tvb, offset, 2, ENC_BIG_ENDIAN);
		} else {
			expert_add_info_format(pinfo, ti, &ei_vtp_vlan_tlvlength_bad, "Source-Routing Ring Number: Bad length %u", length);
		}
		break;

	case SR_BRIDGE_NUM:
		if (length == 2) {
			proto_tree_add_item(tree, hf_vtp_vlan_src_route_bridge_num, tvb, offset, 2, ENC_BIG_ENDIAN);
		} else {
			expert_add_info_format(pinfo, ti, &ei_vtp_vlan_tlvlength_bad, "Source-Routing Bridge Number: Bad length %u", length);
		}
		break;

	case STP_TYPE:
		if (length == 2) {
			proto_tree_add_item(tree, hf_vtp_vlan_stp_type, tvb, offset, 2, ENC_BIG_ENDIAN);
		} else {
			expert_add_info_format(pinfo, ti, &ei_vtp_vlan_tlvlength_bad, "Spanning-Tree Protocol Type: Bad length %u", length);
		}
		break;

	case PARENT_VLAN:
		if (length == 2) {
			proto_tree_add_item(tree, hf_vtp_vlan_parent_vlan, tvb, offset, 2, ENC_BIG_ENDIAN);
		} else {
			expert_add_info_format(pinfo, ti, &ei_vtp_vlan_tlvlength_bad, "Parent VLAN: Bad length %u", length);
		}
		break;

	case TR_BRIDGED_VLANS:
		if (length == 2) {
			proto_tree_add_item(tree, hf_vtp_vlan_translationally_bridged_vlans, tvb, offset, 2, ENC_BIG_ENDIAN);
		} else {
			expert_add_info_format(pinfo, ti, &ei_vtp_vlan_tlvlength_bad, "Translationally Bridged VLANs: Bad length %u", length);
		}
		break;

	case PRUNING:
		if (length == 2) {
			proto_tree_add_item(tree, hf_vtp_vlan_pruning, tvb, offset, 2, ENC_BIG_ENDIAN);
		} else {
			expert_add_info_format(pinfo, ti, &ei_vtp_vlan_tlvlength_bad, "Pruning: Bad length %u", length);
		}
		break;

	case BRIDGE_TYPE:
		if (length == 2) {
			proto_tree_add_item(tree, hf_vtp_vlan_bridge_type, tvb, offset, 2, ENC_BIG_ENDIAN);
		} else {
			expert_add_info_format(pinfo, ti, &ei_vtp_vlan_tlvlength_bad, "Bridge Type: Bad length %u", length);
		}
		break;

	case MAX_ARE_HOP_CNT:
		if (length == 2) {
			proto_tree_add_item(tree, hf_vtp_vlan_max_are_hop_count, tvb, offset, 2, ENC_BIG_ENDIAN);
		} else {
			expert_add_info_format(pinfo, ti, &ei_vtp_vlan_tlvlength_bad, "Max ARE Hop Count: Bad length %u", length);
		}
		break;

	case MAX_STE_HOP_CNT:
		if (length == 2) {
			proto_tree_add_item(tree, hf_vtp_vlan_max_ste_hop_count, tvb, offset, 2, ENC_BIG_ENDIAN);
		} else {
			expert_add_info_format(pinfo, ti, &ei_vtp_vlan_tlvlength_bad, "Max STE Hop Count: Bad length %u", length);
		}
		break;

	case BACKUP_CRF_MODE:
		if (length == 2) {
			proto_tree_add_item(tree, hf_vtp_vlan_backup_crf_mode, tvb, offset, 2, ENC_BIG_ENDIAN);
		} else {
			expert_add_info_format(pinfo, ti, &ei_vtp_vlan_tlvlength_bad, "Backup CRF Mode: Bad length %u", length);
		}
		break;

	default:
		proto_tree_add_item(tree, hf_vtp_vlan_data, tvb, offset, length, ENC_NA);
		break;
	}
}

void
proto_register_vtp(void)
{
	static hf_register_info hf[] = {
		{ &hf_vtp_version,
		{ "Version",	"vtp.version", FT_UINT8, BASE_HEX, NULL, 0x0,
			NULL, HFILL }},

		{ &hf_vtp_code,
		{ "Code",	"vtp.code", FT_UINT8, BASE_HEX, VALS(type_vals), 0x0,
			NULL, HFILL }},

		{ &hf_vtp_followers,
		{ "Followers",	"vtp.followers", FT_UINT8, BASE_DEC, NULL, 0x0,
			"Number of following Subset-Advert messages", HFILL }},

		{ &hf_vtp_md_len,
		{ "Management Domain Length", "vtp.md_len", FT_UINT8, BASE_DEC, NULL, 0x0,
			"Length of management domain string", HFILL }},

		{ &hf_vtp_md,
		{ "Management Domain", "vtp.md", FT_STRING, BASE_NONE, NULL, 0,
			NULL, HFILL }},

		{ &hf_vtp_conf_rev_num,
		{ "Configuration Revision Number", "vtp.conf_rev_num", FT_UINT32, BASE_DEC, NULL, 0x0,
			"Revision number of the configuration information", HFILL }},

		{ &hf_vtp_upd_id,
		{ "Updater Identity", "vtp.upd_id", FT_IPv4, BASE_NONE, NULL, 0x0,
			"IP address of the updater", HFILL }},

		{ &hf_vtp_upd_ts,
		{ "Update Timestamp", "vtp.upd_ts", FT_STRING, BASE_NONE, NULL, 0,
			"Time stamp of the current configuration revision", HFILL }},

		{ &hf_vtp_md5_digest,
		{ "MD5 Digest",	"vtp.md5_digest", FT_BYTES, BASE_NONE, NULL, 0x0,
			NULL, HFILL }},

		{ &hf_vtp_seq_num,
		{ "Sequence Number",	"vtp.seq_num", FT_UINT8, BASE_DEC, NULL, 0x0,
			"Order of this frame in the sequence of Subset-Advert frames", HFILL }},

		{ &hf_vtp_start_value,
		{ "Start Value",	"vtp.start_value", FT_UINT16, BASE_HEX, NULL, 0x0,
			"Virtual LAN ID of first VLAN for which information is requested", HFILL }},

		{ &hf_vtp_vlan_info_len,
		{ "VLAN Information Length",	"vtp.vlan_info.len", FT_UINT8, BASE_DEC, NULL, 0x0,
			"Length of the VLAN information field", HFILL }},

		{ &hf_vtp_vlan_status,
		{ "Status",	"vtp.vlan_info.status", FT_UINT8, BASE_HEX, NULL, 0x0,
			NULL, HFILL }},

		{ &hf_vtp_vlan_status_vlan_susp,
		{ "VLAN suspended",	"vtp.vlan_info.status.vlan_susp", FT_BOOLEAN, 8, NULL, VLAN_SUSPENDED,
			NULL, HFILL }},

		{ &hf_vtp_vlan_type,
		{ "VLAN Type",	"vtp.vlan_info.vlan_type", FT_UINT8, BASE_HEX, VALS(vlan_type_vals), 0x0,
			"Type of VLAN", HFILL }},

		{ &hf_vtp_vlan_name_len,
		{ "VLAN Name Length", "vtp.vlan_info.vlan_name_len", FT_UINT8, BASE_DEC, NULL, 0x0,
			"Length of VLAN name string", HFILL }},

		{ &hf_vtp_isl_vlan_id,
		{ "ISL VLAN ID",	"vtp.vlan_info.isl_vlan_id", FT_UINT16, BASE_HEX, NULL, 0x0,
			"ID of this VLAN on ISL trunks", HFILL }},

		{ &hf_vtp_mtu_size,
		{ "MTU Size",	"vtp.vlan_info.mtu_size", FT_UINT16, BASE_DEC, NULL, 0x0,
			"MTU for this VLAN", HFILL }},

		{ &hf_vtp_802_10_index,
		{ "802.10 Index", "vtp.vlan_info.802_10_index", FT_UINT32, BASE_HEX, NULL, 0x0,
			"IEEE 802.10 security association identifier for this VLAN", HFILL }},

		{ &hf_vtp_vlan_name,
		{ "VLAN Name", "vtp.vlan_info.vlan_name", FT_STRING, BASE_NONE, NULL, 0,
			NULL, HFILL }},

		{ &hf_vtp_vlan_tlvtype,
		{ "Type",	"vtp.vlan_info.tlv_type", FT_UINT8, BASE_HEX, VALS(vlan_tlv_type_vals), 0x0,
			NULL, HFILL }},

		{ &hf_vtp_vlan_tlvlength,
		{ "Length",	"vtp.vlan_info.tlv_len", FT_UINT8, BASE_DEC, NULL, 0x0,
			NULL, HFILL }},

		{ &hf_vtp_pruning_first_vid,
		{ "First VLAN ID",	"vtp.pruning.first", FT_UINT16, BASE_DEC, NULL, 0x0,
			"First VLAN ID for which pruning information is present", HFILL }},

		{ &hf_vtp_pruning_last_vid,
		{ "Last VLAN ID",	"vtp.pruning.last", FT_UINT16, BASE_DEC, NULL, 0x0,
			"Last VLAN ID for which pruning information is present", HFILL }},

		{ &hf_vtp_pruning_active_vid,
		{ "VLAN",	"vtp.pruning.active", FT_UINT16, BASE_DEC, NULL, 0x0,
			"Active advertised VLAN ID", HFILL }},

		{ &hf_vtp_vlan_src_route_ring_num,
		{ "Source-Routing Ring Number",	"vtp.vlan_info.src_route_ring_num", FT_UINT16, BASE_HEX, NULL, 0x0,
			NULL, HFILL }},

		{ &hf_vtp_vlan_src_route_bridge_num,
		{ "Source-Routing Bridge Number", "vtp.vlan_info.src_route_bridge_num", FT_UINT16, BASE_HEX, NULL, 0x0,
			NULL, HFILL }},

		{ &hf_vtp_vlan_stp_type,
		{ "Spanning-Tree Protocol Type", "vtp.vlan_info.stp_type", FT_UINT16, BASE_HEX, VALS(stp_type_vals), 0x0,
			NULL, HFILL }},

		{ &hf_vtp_vlan_parent_vlan,
		{ "Parent VLAN", "vtp.vlan_info.parent_vlan", FT_UINT16, BASE_HEX, NULL, 0x0,
			NULL, HFILL }},

		{ &hf_vtp_vlan_translationally_bridged_vlans,
		{ "Translationally Bridged VLANs", "vtp.vlan_info.translationally_bridged_vlans", FT_UINT16, BASE_HEX, NULL, 0x0,
			NULL, HFILL }},

		{ &hf_vtp_vlan_pruning,
		{ "Pruning", "vtp.vlan_info.pruning", FT_UINT16, BASE_HEX, VALS(pruning_vals), 0x0,
			NULL, HFILL }},

		{ &hf_vtp_vlan_bridge_type,
		{ "Bridge Type", "vtp.vlan_info.bridge_type", FT_UINT16, BASE_HEX, VALS(bridge_type_vals), 0x0,
			NULL, HFILL }},

		{ &hf_vtp_vlan_max_are_hop_count,
		{ "Max ARE Hop Count", "vtp.vlan_info.max_are_hop_count", FT_UINT16, BASE_DEC, NULL, 0x0,
			NULL, HFILL }},

		{ &hf_vtp_vlan_max_ste_hop_count,
		{ "Max STE Hop Count", "vtp.vlan_info.max_ste_hop_count", FT_UINT16, BASE_DEC, NULL, 0x0,
			NULL, HFILL }},

		{ &hf_vtp_vlan_backup_crf_mode,
		{ "Backup CRF Mode", "vtp.vlan_info.backup_crf_mode", FT_UINT16, BASE_HEX, VALS(backup_crf_mode_vals), 0x0,
			NULL, HFILL }},

		{ &hf_vtp_vlan_data,
		{ "Data",	"vtp.vlan_info.data", FT_BYTES, BASE_NONE, NULL, 0x0,
			NULL, HFILL }},

		{ &hf_vtp_reserved,
		{ "Reserved", "vtp.reserved", FT_BYTES, BASE_NONE, NULL, 0,
			NULL, HFILL }},
	};

	static gint *ett[] = {
		&ett_vtp,
		&ett_vtp_vlan_info,
		&ett_vtp_vlan_status,
		&ett_vtp_tlv,
		&ett_vtp_pruning,
	};

	static ei_register_info ei[] = {
		{ &ei_vtp_vlan_tlvlength_bad, { "vtp.vlan_info.tlv_len.bad", PI_PROTOCOL, PI_WARN, "Bad length for TLV length", EXPFILL }},
	};

	expert_module_t* expert_vtp;

	proto_vtp = proto_register_protocol("VLAN Trunking Protocol", "VTP", "vtp");
	proto_register_field_array(proto_vtp, hf, array_length(hf));
	proto_register_subtree_array(ett, array_length(ett));
	expert_vtp = expert_register_protocol(proto_vtp);
	expert_register_field_array(expert_vtp, ei, array_length(ei));
	vtp_handle = register_dissector("vtp", dissect_vtp, proto_vtp);
}

void
proto_reg_handoff_vtp(void)
{
	dissector_add_uint("llc.cisco_pid", CISCO_PID_VTP, vtp_handle);
}

/*
 * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 *
 * Local variables:
 * c-basic-offset: 8
 * tab-width: 8
 * indent-tabs-mode: t
 * End:
 *
 * vi: set shiftwidth=8 tabstop=8 noexpandtab:
 * :indentSize=8:tabSize=8:noTabs=false:
 */