packet-vtp.c

   1 /* packet-vtp.c
   2  * Routines for the disassembly of Cisco's Virtual Trunking Protocol
   3  *
   4  * $Id: packet-vtp.c,v 1.21 2002/08/28 21:00:36 jmayer Exp $
   5  *
   6  * Ethereal - Network traffic analyzer
   7  * By Gerald Combs <gerald@ethereal.com>
   8  * Copyright 1998 Gerald Combs
   9  *
  10  * This program is free software; you can redistribute it and/or
  11  * modify it under the terms of the GNU General Public License
  12  * as published by the Free Software Foundation; either version 2
  13  * of the License, or (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  23  */
  24
  25 #include "config.h"
  26
  27 #include <stdlib.h>
  28 #include <string.h>
  29
  30 #include <glib.h>
  31 #include <epan/packet.h>
  32
  33 /*
  34  * See
  35  *
  36  *      http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/frames.htm
  37  *
  38  * for some information on VTP.
  39  *
  40  * It's incomplete, and it appears to be inaccurate in a number of places,
  41  * but it's all I could find....
  42  */
  43
  44 static int proto_vtp = -1;
  45 static int hf_vtp_version = -1;
  46 static int hf_vtp_code = -1;
  47 static int hf_vtp_followers = -1;
  48 static int hf_vtp_md_len = -1;
  49 static int hf_vtp_md = -1;
  50 static int hf_vtp_conf_rev_num = -1;
  51 static int hf_vtp_upd_id = -1;
  52 static int hf_vtp_upd_ts = -1;
  53 static int hf_vtp_md5_digest = -1;
  54 static int hf_vtp_seq_num = -1;
  55 static int hf_vtp_start_value = -1;
  56 static int hf_vtp_vlan_info_len = -1;
  57 static int hf_vtp_vlan_status_vlan_susp = -1;
  58 static int hf_vtp_vlan_type = -1;
  59 static int hf_vtp_vlan_name_len = -1;
  60 static int hf_vtp_isl_vlan_id = -1;
  61 static int hf_vtp_mtu_size = -1;
  62 static int hf_vtp_802_10_index = -1;
  63 static int hf_vtp_vlan_name = -1;
  64 static int hf_vtp_vlan_tlvtype = -1;
  65 static int hf_vtp_vlan_tlvlength = -1;
  66
  67 static gint ett_vtp = -1;
  68 static gint ett_vtp_vlan_info = -1;
  69 static gint ett_vtp_vlan_status = -1;
  70 static gint ett_vtp_tlv = -1;
  71
  72 static int
  73 dissect_vlan_info(tvbuff_t *tvb, int offset, proto_tree *tree);
  74 static void
  75 dissect_vlan_info_tlv(tvbuff_t *tvb, int offset, int length,
  76     proto_tree *tree, proto_item *ti, guint8 type);
  77
  78 #define SUMMARY_ADVERT          0x01
  79 #define SUBSET_ADVERT           0x02
  80 #define ADVERT_REQUEST          0x03
  81
  82 static const value_string type_vals[] = {
  83         { SUMMARY_ADVERT, "Summary-Advert" },
  84         { SUBSET_ADVERT,  "Subset-Advert" },
  85         { ADVERT_REQUEST, "Advert-Request" },
  86         { 0,              NULL },
  87 };
  88
  89 static void
  90 dissect_vtp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  91 {
  92         proto_item *ti;
  93         proto_tree *vtp_tree = NULL;
  94         int offset = 0;
  95         guint8 code;
  96         guint8 md_len;
  97         const guint8 *upd_timestamp;
  98         int vlan_info_len;
  99
 100         if (check_col(pinfo->cinfo, COL_PROTOCOL))
 101                 col_set_str(pinfo->cinfo, COL_PROTOCOL, "VTP");
 102         if (check_col(pinfo->cinfo, COL_INFO))
 103                 col_set_str(pinfo->cinfo, COL_INFO, "Virtual Trunking Protocol");
 104
 105         if (tree) {
 106                 ti = proto_tree_add_item(tree, proto_vtp, tvb, offset, -1,
 107                     FALSE);
 108                 vtp_tree = proto_item_add_subtree(ti, ett_vtp);
 109
 110                 proto_tree_add_item(vtp_tree, hf_vtp_version, tvb, offset, 1,
 111                     FALSE);
 112                 offset += 1;
 113
 114                 code = tvb_get_guint8(tvb, offset);
 115                 proto_tree_add_uint(vtp_tree, hf_vtp_code, tvb, offset, 1,
 116                     code);
 117                 offset += 1;
 118
 119                 switch (code) {
 120
 121                 case SUMMARY_ADVERT:
 122                         proto_tree_add_item(vtp_tree, hf_vtp_followers, tvb, offset,
 123                             1, FALSE);
 124                         offset += 1;
 125
 126                         md_len = tvb_get_guint8(tvb, offset);
 127                         proto_tree_add_uint(vtp_tree, hf_vtp_md_len, tvb, offset,
 128                             1, md_len);
 129                         offset += 1;
 130
 131                         proto_tree_add_item(vtp_tree, hf_vtp_md, tvb, offset,
 132                             32, FALSE);
 133                         offset += 32;
 134
 135                         proto_tree_add_item(vtp_tree, hf_vtp_conf_rev_num, tvb,
 136                             offset, 4, FALSE);
 137                         offset += 4;
 138
 139                         proto_tree_add_item(vtp_tree, hf_vtp_upd_id, tvb,
 140                             offset, 4, FALSE);
 141                         offset += 4;
 142
 143                         upd_timestamp = tvb_get_ptr(tvb, offset, 12);
 144                         proto_tree_add_string_format(vtp_tree, hf_vtp_upd_ts, tvb,
 145                             offset, 12, upd_timestamp,
 146                             "Update Timestamp: %.2s-%.2s-%.2s %.2s:%.2s:%.2s",
 147                             &upd_timestamp[0], &upd_timestamp[2], &upd_timestamp[4],
 148                             &upd_timestamp[6], &upd_timestamp[8], &upd_timestamp[10]);
 149                         offset += 12;
 150
 151                         proto_tree_add_item(vtp_tree, hf_vtp_md5_digest, tvb,
 152                             offset, 16, FALSE);
 153                         break;
 154
 155                 case SUBSET_ADVERT:
 156                         proto_tree_add_item(vtp_tree, hf_vtp_seq_num, tvb, offset,
 157                             1, FALSE);
 158                         offset += 1;
 159
 160                         md_len = tvb_get_guint8(tvb, offset);
 161                         proto_tree_add_uint(vtp_tree, hf_vtp_md_len, tvb, offset,
 162                             1, md_len);
 163                         offset += 1;
 164
 165                         proto_tree_add_item(vtp_tree, hf_vtp_md, tvb, offset,
 166                             32, FALSE);
 167                         offset += 32;
 168
 169                         proto_tree_add_item(vtp_tree, hf_vtp_conf_rev_num, tvb,
 170                             offset, 4, FALSE);
 171                         offset += 4;
 172
 173                         while (tvb_reported_length_remaining(tvb, offset) > 0) {
 174                                 vlan_info_len =
 175                                     dissect_vlan_info(tvb, offset, vtp_tree);
 176                                 if (vlan_info_len < 0)
 177                                         break;
 178                                 offset += vlan_info_len;
 179                         }
 180                         break;
 181
 182                 case ADVERT_REQUEST:
 183                         offset += 1;    /* skip reserved field */
 184
 185                         md_len = tvb_get_guint8(tvb, offset);
 186                         proto_tree_add_uint(vtp_tree, hf_vtp_md_len, tvb, offset,
 187                             1, md_len);
 188                         offset += 1;
 189
 190                         proto_tree_add_item(vtp_tree, hf_vtp_start_value, tvb,
 191                             offset, 2, FALSE);
 192                         break;
 193
 194                 case 0x04:
 195                         /*
 196                          * Mysterious type, seen a lot.
 197                          * Is this some mutant variant of Advert-Request?
 198                          */
 199                         offset += 1;    /* skip unknown field */
 200
 201                         md_len = tvb_get_guint8(tvb, offset);
 202                         proto_tree_add_uint(vtp_tree, hf_vtp_md_len, tvb, offset,
 203                             1, md_len);
 204                         offset += 1;
 205
 206                         proto_tree_add_item(vtp_tree, hf_vtp_md, tvb, offset,
 207                             32, FALSE);
 208                         offset += 32;
 209
 210                         offset += 2;    /* skip unknown field */
 211
 212                         proto_tree_add_text(vtp_tree, tvb, offset, 2,
 213                             "VLAN ID of some sort: 0x%04x",
 214                             tvb_get_ntohs(tvb, offset));
 215                         offset += 2;
 216                         break;
 217                 }
 218         }
 219 }
 220
 221 #define VLAN_SUSPENDED  0x01
 222
 223 static const value_string vlan_type_vals[] = {
 224         { 0x01, "Ethernet" },
 225         { 0x02, "FDDI" },
 226         { 0x03, "TrCRF" },
 227         { 0x04, "FDDI-net" },
 228         { 0x05, "TrBRF" },
 229         { 0,    NULL },
 230 };
 231
 232 #define SR_RING_NUM             0x01
 233 #define SR_BRIDGE_NUM           0x02
 234 #define STP_TYPE                0x03
 235 #define PARENT_VLAN             0x04
 236 #define TR_BRIDGED_VLANS        0x05
 237 #define PRUNING                 0x06
 238 #define BRIDGE_TYPE             0x07
 239 #define MAX_ARE_HOP_CNT         0x08
 240 #define MAX_STE_HOP_CNT         0x09
 241 #define BACKUP_CRF_MODE         0x0A
 242
 243 static const value_string vlan_tlv_type_vals[] = {
 244         { SR_RING_NUM,      "Source-Routing Ring Number" },
 245         { SR_BRIDGE_NUM,    "Source-Routing Bridge Number" },
 246         { STP_TYPE,         "Spanning-Tree Protocol Type" },
 247         { PARENT_VLAN,      "Parent VLAN" },
 248         { TR_BRIDGED_VLANS, "Translationally Bridged VLANs" },
 249         { PRUNING,          "Pruning" },
 250         { BRIDGE_TYPE,      "Bridge Type" },
 251         { MAX_ARE_HOP_CNT,  "Max ARE Hop Count" },
 252         { MAX_STE_HOP_CNT,  "Max STE Hop Count" },
 253         { BACKUP_CRF_MODE,  "Backup CRF Mode" },
 254         { 0,                NULL },
 255 };
 256
 257 static int
 258 dissect_vlan_info(tvbuff_t *tvb, int offset, proto_tree *tree)
 259 {
 260         proto_item *ti;
 261         proto_tree *vlan_info_tree;
 262         proto_tree *status_tree;
 263         guint8 vlan_info_len;
 264         int vlan_info_left;
 265         guint8 status;
 266         guint8 vlan_name_len;
 267         guint8 type;
 268         int length;
 269         proto_tree *tlv_tree;
 270
 271         vlan_info_len = tvb_get_guint8(tvb, offset);
 272         ti = proto_tree_add_text(tree, tvb, offset, vlan_info_len,
 273             "VLAN Information");
 274         vlan_info_tree = proto_item_add_subtree(ti, ett_vtp_vlan_info);
 275         vlan_info_left = vlan_info_len;
 276
 277         proto_tree_add_uint(vlan_info_tree, hf_vtp_vlan_info_len, tvb, offset, 1,
 278             vlan_info_len);
 279         offset += 1;
 280         vlan_info_left -= 1;
 281
 282         if (vlan_info_left < 1)
 283                 return -1;
 284         status = tvb_get_guint8(tvb, offset);
 285         ti = proto_tree_add_text(vlan_info_tree, tvb, offset, 1,
 286             "Status: 0x%02x%s", status,
 287             (status & VLAN_SUSPENDED) ? "(VLAN suspended)" : "");
 288         status_tree = proto_item_add_subtree(ti, ett_vtp_vlan_status);
 289         proto_tree_add_boolean(status_tree, hf_vtp_vlan_status_vlan_susp, tvb, offset, 1,
 290             status);
 291         offset += 1;
 292         vlan_info_left -= 1;
 293
 294         if (vlan_info_left < 1)
 295                 return -1;
 296         proto_tree_add_item(vlan_info_tree, hf_vtp_vlan_type, tvb, offset, 1,
 297             FALSE);
 298         offset += 1;
 299         vlan_info_left -= 1;
 300
 301         if (vlan_info_left < 1)
 302                 return -1;
 303         vlan_name_len = tvb_get_guint8(tvb, offset);
 304         proto_tree_add_uint(vlan_info_tree, hf_vtp_vlan_name_len, tvb, offset, 1,
 305             vlan_name_len);
 306         offset += 1;
 307         vlan_info_left -= 1;
 308
 309         if (vlan_info_left < 2)
 310                 return -1;
 311         proto_tree_add_item(vlan_info_tree, hf_vtp_isl_vlan_id, tvb, offset, 2,
 312             FALSE);
 313         offset += 2;
 314         vlan_info_left -= 2;
 315
 316         if (vlan_info_left < 2)
 317                 return -1;
 318         proto_tree_add_item(vlan_info_tree, hf_vtp_mtu_size, tvb, offset, 2,
 319             FALSE);
 320         offset += 2;
 321         vlan_info_left -= 2;
 322
 323         if (vlan_info_left < 4)
 324                 return -1;
 325         proto_tree_add_item(vlan_info_tree, hf_vtp_802_10_index, tvb, offset, 4,
 326             FALSE);
 327         offset += 4;
 328         vlan_info_left -= 4;
 329
 330         /* VLAN name length appears to be rounded up to a multiple of 4. */
 331         vlan_name_len = 4*((vlan_name_len + 3)/4);
 332         if (vlan_info_left < vlan_name_len)
 333                 return -1;
 334         proto_tree_add_item(vlan_info_tree, hf_vtp_vlan_name, tvb, offset,
 335             vlan_name_len, FALSE);
 336         offset += vlan_name_len;
 337         vlan_info_left -= vlan_name_len;
 338
 339         while (vlan_info_left > 0) {
 340                 type = tvb_get_guint8(tvb, offset + 0);
 341                 length = tvb_get_guint8(tvb, offset + 1);
 342
 343                 ti = proto_tree_add_text(vlan_info_tree, tvb, offset,
 344                     2 + length*2, "%s",
 345                     val_to_str(type, vlan_tlv_type_vals,
 346                       "Unknown TLV type: 0x%02x"));
 347                 tlv_tree = proto_item_add_subtree(ti, ett_vtp_tlv);
 348                 proto_tree_add_uint(tlv_tree, hf_vtp_vlan_tlvtype, tvb, offset,
 349                     1, type);
 350                 proto_tree_add_uint(tlv_tree, hf_vtp_vlan_tlvlength, tvb, offset+1,
 351                     1, length);
 352                 offset += 2;
 353                 vlan_info_left -= 2;
 354                 if (length > 0) {
 355                         dissect_vlan_info_tlv(tvb, offset, length*2, tlv_tree,
 356                             ti, type);
 357                 }
 358                 offset += length*2;
 359                 vlan_info_left -= length*2;
 360         }
 361
 362         return vlan_info_len;
 363 }
 364
 365 static const value_string stp_type_vals[] = {
 366         { 1, "SRT" },
 367         { 2, "SRB" },
 368         { 3, "Auto" },
 369         { 0, NULL },
 370 };
 371
 372 static const value_string pruning_vals[] = {
 373         { 1, "Enabled" },
 374         { 2, "Disabled" },
 375         { 0, NULL },
 376 };
 377
 378 static const value_string bridge_type_vals[] = {
 379         { 1, "SRT" },
 380         { 2, "SRB" },
 381         { 0, NULL },
 382 };
 383
 384 static const value_string backup_crf_mode_vals[] = {
 385         { 1, "TrCRF is configured as a backup" },
 386         { 2, "TrCRF is not configured as a backup" },
 387         { 0, NULL },
 388 };
 389
 390 static void
 391 dissect_vlan_info_tlv(tvbuff_t *tvb, int offset, int length,
 392     proto_tree *tree, proto_item *ti, guint8 type)
 393 {
 394         switch (type) {
 395
 396         case SR_RING_NUM:
 397                 if (length == 2) {
 398                         proto_item_set_text(ti,
 399                             "Source-Routing Ring Number: 0x%04x",
 400                             tvb_get_ntohs(tvb, offset));
 401                         proto_tree_add_text(tree, tvb, offset, 2,
 402                             "Source-Routing Ring Number: 0x%04x",
 403                             tvb_get_ntohs(tvb, offset));
 404                 } else {
 405                         proto_item_set_text(ti,
 406                             "Source-Routing Ring Number: Bad length %u",
 407                             length);
 408                         proto_tree_add_text(tree, tvb, offset, length,
 409                             "Source-Routing Ring Number: Bad length %u",
 410                             length);
 411                 }
 412                 break;
 413
 414         case SR_BRIDGE_NUM:
 415                 if (length == 2) {
 416                         proto_item_set_text(ti,
 417                             "Source-Routing Bridge Number: 0x%04x",
 418                             tvb_get_ntohs(tvb, offset));
 419                         proto_tree_add_text(tree, tvb, offset, 2,
 420                             "Source-Routing Bridge Number: 0x%04x",
 421                             tvb_get_ntohs(tvb, offset));
 422                 } else {
 423                         proto_item_set_text(ti,
 424                             "Source-Routing Bridge Number: Bad length %u",
 425                             length);
 426                         proto_tree_add_text(tree, tvb, offset, length,
 427                             "Source-Routing Bridge Number: Bad length %u",
 428                             length);
 429                 }
 430                 break;
 431
 432         case STP_TYPE:
 433                 if (length == 2) {
 434                         proto_item_set_text(ti,
 435                             "Spanning-Tree Protocol Type: %s",
 436                             val_to_str(tvb_get_ntohs(tvb, offset), stp_type_vals,
 437                               "Unknown (0x%04x)"));
 438                         proto_tree_add_text(tree, tvb, offset, 2,
 439                             "Spanning-Tree Protocol Type: %s",
 440                             val_to_str(tvb_get_ntohs(tvb, offset), stp_type_vals,
 441                               "Unknown (0x%04x)"));
 442                 } else {
 443                         proto_item_set_text(ti,
 444                             "Spanning-Tree Protocol Type: Bad length %u",
 445                             length);
 446                         proto_tree_add_text(tree, tvb, offset, length,
 447                             "Spanning-Tree Protocol Type: Bad length %u",
 448                             length);
 449                 }
 450                 break;
 451
 452         case PARENT_VLAN:
 453                 if (length == 2) {
 454                         proto_item_set_text(ti,
 455                             "Parent VLAN: 0x%04x",
 456                             tvb_get_ntohs(tvb, offset));
 457                         proto_tree_add_text(tree, tvb, offset, 2,
 458                             "Parent VLAN: 0x%04x",
 459                             tvb_get_ntohs(tvb, offset));
 460                 } else {
 461                         proto_item_set_text(ti,
 462                             "Parent VLAN: Bad length %u",
 463                             length);
 464                         proto_tree_add_text(tree, tvb, offset, length,
 465                             "Parent VLAN: Bad length %u",
 466                             length);
 467                 }
 468                 break;
 469
 470         case TR_BRIDGED_VLANS:
 471                 if (length == 2) {
 472                         proto_item_set_text(ti,
 473                             "Translationally Bridged VLANs: 0x%04x",
 474                             tvb_get_ntohs(tvb, offset));
 475                         proto_tree_add_text(tree, tvb, offset, 2,
 476                             "Translationally Bridged VLANs: 0x%04x",
 477                             tvb_get_ntohs(tvb, offset));
 478                 } else {
 479                         proto_item_set_text(ti,
 480                             "Translationally Bridged VLANs: Bad length %u",
 481                             length);
 482                         proto_tree_add_text(tree, tvb, offset, length,
 483                             "Translationally Bridged VLANs: Bad length %u",
 484                             length);
 485                 }
 486                 break;
 487
 488         case PRUNING:
 489                 if (length == 2) {
 490                         proto_item_set_text(ti,
 491                             "Pruning: %s",
 492                             val_to_str(tvb_get_ntohs(tvb, offset), pruning_vals,
 493                               "Unknown (0x%04x)"));
 494                         proto_tree_add_text(tree, tvb, offset, 2,
 495                             "Pruning: %s",
 496                             val_to_str(tvb_get_ntohs(tvb, offset), pruning_vals,
 497                               "Unknown (0x%04x)"));
 498                 } else {
 499                         proto_item_set_text(ti,
 500                             "Pruning: Bad length %u",
 501                             length);
 502                         proto_tree_add_text(tree, tvb, offset, length,
 503                             "Pruning: Bad length %u",
 504                             length);
 505                 }
 506                 break;
 507
 508         case BRIDGE_TYPE:
 509                 if (length == 2) {
 510                         proto_item_set_text(ti,
 511                             "Bridge Type: %s",
 512                             val_to_str(tvb_get_ntohs(tvb, offset), bridge_type_vals,
 513                               "Unknown (0x%04x)"));
 514                         proto_tree_add_text(tree, tvb, offset, 2,
 515                             "Bridge Type: %s",
 516                             val_to_str(tvb_get_ntohs(tvb, offset), bridge_type_vals,
 517                               "Unknown (0x%04x)"));
 518                 } else {
 519                         proto_item_set_text(ti,
 520                             "Bridge Type: Bad length %u",
 521                             length);
 522                         proto_tree_add_text(tree, tvb, offset, length,
 523                             "Bridge Type: Bad length %u",
 524                             length);
 525                 }
 526                 break;
 527
 528         case MAX_ARE_HOP_CNT:
 529                 if (length == 2) {
 530                         proto_item_set_text(ti,
 531                             "Max ARE Hop Count: %u",
 532                             tvb_get_ntohs(tvb, offset));
 533                         proto_tree_add_text(tree, tvb, offset, 2,
 534                             "Max ARE Hop Count: %u",
 535                             tvb_get_ntohs(tvb, offset));
 536                 } else {
 537                         proto_item_set_text(ti,
 538                             "Max ARE Hop Count: Bad length %u",
 539                             length);
 540                         proto_tree_add_text(tree, tvb, offset, length,
 541                             "Max ARE Hop Count: Bad length %u",
 542                             length);
 543                 }
 544                 break;
 545
 546         case MAX_STE_HOP_CNT:
 547                 if (length == 2) {
 548                         proto_item_set_text(ti,
 549                             "Max STE Hop Count: %u",
 550                             tvb_get_ntohs(tvb, offset));
 551                         proto_tree_add_text(tree, tvb, offset, 2,
 552                             "Max STE Hop Count: %u",
 553                             tvb_get_ntohs(tvb, offset));
 554                 } else {
 555                         proto_item_set_text(ti,
 556                             "Max STE Hop Count: Bad length %u",
 557                             length);
 558                         proto_tree_add_text(tree, tvb, offset, length,
 559                             "Max STE Hop Count: Bad length %u",
 560                             length);
 561                 }
 562                 break;
 563
 564         case BACKUP_CRF_MODE:
 565                 if (length == 2) {
 566                         proto_item_set_text(ti,
 567                             "Backup CRF Mode: %s",
 568                             val_to_str(tvb_get_ntohs(tvb, offset), backup_crf_mode_vals,
 569                               "Unknown (0x%04x)"));
 570                         proto_tree_add_text(tree, tvb, offset, 2,
 571                             "Backup CRF Mode: %s",
 572                             val_to_str(tvb_get_ntohs(tvb, offset), backup_crf_mode_vals,
 573                               "Unknown (0x%04x)"));
 574                 } else {
 575                         proto_item_set_text(ti,
 576                             "Backup CRF Mode: Bad length %u",
 577                             length);
 578                         proto_tree_add_text(tree, tvb, offset, length,
 579                             "Backup CRF Mode: Bad length %u",
 580                             length);
 581                 }
 582                 break;
 583
 584         default:
 585                 proto_tree_add_text(tree, tvb, offset, length, "Data");
 586                 break;
 587         }
 588 }
 589
 590 void
 591 proto_register_vtp(void)
 592 {
 593         static hf_register_info hf[] = {
 594                 { &hf_vtp_version,
 595                 { "Version",    "vtp.version", FT_UINT8, BASE_HEX, NULL, 0x0,
 596                         "", HFILL }},
 597
 598                 { &hf_vtp_code,
 599                 { "Code",       "vtp.code", FT_UINT8, BASE_HEX, VALS(type_vals), 0x0,
 600                         "", HFILL }},
 601
 602                 { &hf_vtp_followers,
 603                 { "Followers",  "vtp.followers", FT_UINT8, BASE_DEC, NULL, 0x0,
 604                         "Number of following Subset-Advert messages", HFILL }},
 605
 606                 { &hf_vtp_md_len,
 607                 { "Management Domain Length", "vtp.md_len", FT_UINT8, BASE_DEC, NULL, 0x0,
 608                         "Length of management domain string", HFILL }},
 609
 610                 { &hf_vtp_md,
 611                 { "Management Domain", "vtp.md", FT_STRING, BASE_DEC, NULL, 0,
 612                         "Management domain", HFILL }},
 613
 614                 { &hf_vtp_conf_rev_num,
 615                 { "Configuration Revision Number", "vtp.conf_rev_num", FT_UINT32, BASE_DEC, NULL, 0x0,
 616                         "Revision number of the configuration information", HFILL }},
 617
 618                 { &hf_vtp_upd_id,
 619                 { "Updater Identity", "vtp.upd_id", FT_IPv4, BASE_NONE, NULL, 0x0,
 620                         "IP address of the updater", HFILL }},
 621
 622                 { &hf_vtp_upd_ts,
 623                 { "Update Timestamp", "vtp.upd_ts", FT_STRING, BASE_DEC, NULL, 0,
 624                         "Time stamp of the current configuration revision", HFILL }},
 625
 626                 { &hf_vtp_md5_digest,
 627                 { "MD5 Digest", "vtp.md5_digest", FT_BYTES, BASE_HEX, NULL, 0x0,
 628                         "", HFILL }},
 629
 630                 { &hf_vtp_seq_num,
 631                 { "Sequence Number",    "vtp.seq_num", FT_UINT8, BASE_DEC, NULL, 0x0,
 632                         "Order of this frame in the sequence of Subset-Advert frames", HFILL }},
 633
 634                 { &hf_vtp_start_value,
 635                 { "Start Value",        "vtp.start_value", FT_UINT16, BASE_HEX, NULL, 0x0,
 636                         "Virtual LAN ID of first VLAN for which information is requested", HFILL }},
 637
 638                 { &hf_vtp_vlan_info_len,
 639                 { "VLAN Information Length",    "vtp.vlan_info.len", FT_UINT8, BASE_DEC, NULL, 0x0,
 640                         "Length of the VLAN information field", HFILL }},
 641
 642                 { &hf_vtp_vlan_status_vlan_susp,
 643                 { "VLAN suspended",     "vtp.vlan_info.status.vlan_susp", FT_BOOLEAN, 8, NULL, VLAN_SUSPENDED,
 644                         "VLAN suspended", HFILL }},
 645
 646                 { &hf_vtp_vlan_type,
 647                 { "VLAN Type",  "vtp.vlan_info.vlan_type", FT_UINT8, BASE_HEX, VALS(vlan_type_vals), 0x0,
 648                         "Type of VLAN", HFILL }},
 649
 650                 { &hf_vtp_vlan_name_len,
 651                 { "VLAN Name Length", "vtp.vlan_info.vlan_name_len", FT_UINT8, BASE_DEC, NULL, 0x0,
 652                         "Length of VLAN name string", HFILL }},
 653
 654                 { &hf_vtp_isl_vlan_id,
 655                 { "ISL VLAN ID",        "vtp.vlan_info.isl_vlan_id", FT_UINT16, BASE_HEX, NULL, 0x0,
 656                         "ID of this VLAN on ISL trunks", HFILL }},
 657
 658                 { &hf_vtp_mtu_size,
 659                 { "MTU Size",   "vtp.vlan_info.mtu_size", FT_UINT16, BASE_DEC, NULL, 0x0,
 660                         "MTU for this VLAN", HFILL }},
 661
 662                 { &hf_vtp_802_10_index,
 663                 { "802.10 Index", "vtp.vlan_info.802_10_index", FT_UINT32, BASE_HEX, NULL, 0x0,
 664                         "IEEE 802.10 security association identifier for this VLAN", HFILL }},
 665
 666                 { &hf_vtp_vlan_name,
 667                 { "VLAN Name", "vtp.vlan_info.vlan_name", FT_STRING, BASE_DEC, NULL, 0,
 668                         "VLAN name", HFILL }},
 669
 670                 { &hf_vtp_vlan_tlvtype,
 671                 { "Type",       "vtp.vlan_info.tlv_type", FT_UINT8, BASE_HEX, VALS(vlan_tlv_type_vals), 0x0,
 672                         "", HFILL }},
 673
 674                 { &hf_vtp_vlan_tlvlength,
 675                 { "Length",     "vtp.vlan_info.tlv_len", FT_UINT8, BASE_DEC, NULL, 0x0,
 676                         "", HFILL }},
 677         };
 678         static gint *ett[] = {
 679                 &ett_vtp,
 680                 &ett_vtp_vlan_info,
 681                 &ett_vtp_vlan_status,
 682                 &ett_vtp_tlv,
 683         };
 684
 685         proto_vtp = proto_register_protocol("Virtual Trunking Protocol",
 686             "VTP", "vtp");
 687         proto_register_field_array(proto_vtp, hf, array_length(hf));
 688         proto_register_subtree_array(ett, array_length(ett));
 689 }
 690
 691 void
 692 proto_reg_handoff_vtp(void)
 693 {
 694         dissector_handle_t vtp_handle;
 695
 696         vtp_handle = create_dissector_handle(dissect_vtp, proto_vtp);
 697         dissector_add("llc.cisco_pid", 0x2003, vtp_handle);
 698 }