packet-dvmrp.c

   1 /* packet-dvmrp.c   2001 Ronnie Sahlberg <See AUTHORS for email>
   2  * Routines for IGMP/DVMRP packet disassembly
   3  *
   4  * $Id: packet-dvmrp.c,v 1.9 2002/04/02 05:12:12 guy 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
  26
  27                         DVMRP   DVMRP
  28         code            v1      v3
  29
  30         0x01            *       *
  31         0x02            *       *
  32         0x03            x
  33         0x04            x
  34         0x07                    x
  35         0x08                    x
  36         0x09                    x
  37
  38
  39         * V3 has len>=8 and byte[6]==0xff and byte[7]==0x03
  40
  41
  42         DVMRP is defined in the following RFCs
  43         RFC1075 Version 1
  44         draft-ietf-idmr-dvmrp-v3-10.txt Version 3
  45
  46         V1 and V3 can be distinguished by looking at bytes 6 and 7 in the
  47         IGMP/DVMRP header.
  48         If header[6]==0xff and header[7]==0x03 we have version 3.
  49
  50
  51         RFC1075 has typos in 3.12.2 and 3.12.4, see if you can spot them.
  52 */
  53
  54 #ifdef HAVE_CONFIG_H
  55 # include "config.h"
  56 #endif
  57
  58 #ifdef HAVE_SYS_TYPES_H
  59 # include <sys/types.h>
  60 #endif
  61
  62 #include <stdio.h>
  63 #include <string.h>
  64 #include <glib.h>
  65
  66 #include <epan/packet.h>
  67 #include "ipproto.h"
  68 #include "packet-igmp.h"
  69 #include "packet-dvmrp.h"
  70
  71 static int proto_dvmrp = -1;
  72 static int hf_version = -1;
  73 static int hf_type = -1;
  74 static int hf_code_v1 = -1;
  75 static int hf_checksum = -1;
  76 static int hf_checksum_bad = -1;
  77 static int hf_commands = -1;
  78 static int hf_command = -1;
  79 static int hf_count = -1;
  80 static int hf_afi = -1;
  81 static int hf_netmask = -1;
  82 static int hf_metric = -1;
  83 static int hf_dest_unr = -1;
  84 static int hf_split_horiz = -1;
  85 static int hf_infinity = -1;
  86 static int hf_daddr = -1;
  87 static int hf_maddr = -1;
  88 static int hf_hold = -1;
  89 static int hf_code_v3 = -1;
  90 static int hf_capabilities = -1;
  91 static int hf_cap_leaf = -1;
  92 static int hf_cap_prune = -1;
  93 static int hf_cap_genid = -1;
  94 static int hf_cap_mtrace = -1;
  95 static int hf_cap_snmp = -1;
  96 static int hf_cap_netmask = -1;
  97 static int hf_min_ver = -1;
  98 static int hf_maj_ver = -1;
  99 static int hf_genid = -1;
 100 static int hf_route = -1;
 101 static int hf_saddr = -1;
 102 static int hf_life = -1;
 103 static int hf_neighbor = -1;
 104
 105 static int ett_dvmrp = -1;
 106 static int ett_commands = -1;
 107 static int ett_capabilities = -1;
 108 static int ett_route = -1;
 109
 110
 111 #define DVMRP_TYPE                              0x13
 112 static const value_string dvmrp_type[] = {
 113         {DVMRP_TYPE,    "DVMRP" },
 114         {0,             NULL}
 115 };
 116
 117 #define DVMRP_V1_RESPONSE                       1
 118 #define DVMRP_V1_REQUEST                        2
 119 #define DVMRP_V1_NON_MEMBERSHIP_REPORT          3
 120 #define DVMRP_V1_NON_MEMBERSHIP_CANCELLATION    4
 121 static const value_string code_v1[] = {
 122         {DVMRP_V1_RESPONSE,                     "Response"                      },
 123         {DVMRP_V1_REQUEST,                      "Request"                       },
 124         {DVMRP_V1_NON_MEMBERSHIP_REPORT,        "Non-membership report"         },
 125         {DVMRP_V1_NON_MEMBERSHIP_CANCELLATION,  "Non-membership cancellation"   },
 126         {0,                                     NULL}
 127 };
 128
 129 #define DVMRP_V3_PROBE                          0x1
 130 #define DVMRP_V3_REPORT                         0x2
 131 #define DVMRP_V3_ASK_NEIGHBORS                  0x3
 132 #define DVMRP_V3_NEIGHBORS                      0x4
 133 #define DVMRP_V3_ASK_NEIGHBORS_2                0x5
 134 #define DVMRP_V3_NEIGHBORS_2                    0x6
 135 #define DVMRP_V3_PRUNE                          0x7
 136 #define DVMRP_V3_GRAFT                          0x8
 137 #define DVMRP_V3_GRAFT_ACK                      0x9
 138 static const value_string code_v3[] = {
 139         {DVMRP_V3_PROBE,                "Probe"},
 140         {DVMRP_V3_REPORT,               "Report"},
 141         {DVMRP_V3_ASK_NEIGHBORS,        "Ask Neighbors"},
 142         {DVMRP_V3_NEIGHBORS,            "Neighbors"},
 143         {DVMRP_V3_ASK_NEIGHBORS_2,      "Ask Neighbors 2"},
 144         {DVMRP_V3_NEIGHBORS_2,          "Neighbors 2"},
 145         {DVMRP_V3_PRUNE,                "Prune"},
 146         {DVMRP_V3_GRAFT,                "Graft"},
 147         {DVMRP_V3_GRAFT_ACK,            "Graft ACK"},
 148         {0,                             NULL}
 149 };
 150
 151 #define DVMRP_V3_CAP_LEAF       0x01
 152 #define DVMRP_V3_CAP_PRUNE      0x02
 153 #define DVMRP_V3_CAP_GENID      0x04
 154 #define DVMRP_V3_CAP_MTRACE     0x08
 155 #define DVMRP_V3_CAP_SNMP       0x10
 156 #define DVMRP_V3_CAP_NETMASK    0x20
 157
 158
 159 #define V1_COMMAND_NULL         0
 160 #define V1_COMMAND_AFI          2
 161 #define V1_COMMAND_SUBNETMASK   3
 162 #define V1_COMMAND_METRIC       4
 163 #define V1_COMMAND_FLAGS0       5
 164 #define V1_COMMAND_INFINITY     6
 165 #define V1_COMMAND_DA           7
 166 #define V1_COMMAND_RDA          8
 167 #define V1_COMMAND_NMR          9
 168 #define V1_COMMAND_NMR_CANCEL   10
 169 static const value_string command[] = {
 170         {V1_COMMAND_NULL,       "NULL"  },
 171         {V1_COMMAND_AFI,        "Address Family Indicator"},
 172         {V1_COMMAND_SUBNETMASK, "Subnetmask"},
 173         {V1_COMMAND_METRIC,     "Metric"},
 174         {V1_COMMAND_FLAGS0,     "Flags0"},
 175         {V1_COMMAND_INFINITY,   "Infinity"},
 176         {V1_COMMAND_DA,         "Destination Address"},
 177         {V1_COMMAND_RDA,        "Requested Destination Address"},
 178         {V1_COMMAND_NMR,        "Non-Membership Report"},
 179         {V1_COMMAND_NMR_CANCEL, "Non-Membership Report Cancel"},
 180         {0,                     NULL}
 181 };
 182
 183 #define V1_AFI_IP               2
 184 static const value_string afi[] = {
 185         {V1_AFI_IP,     "IP v4 Family"},
 186         {0,             NULL}
 187 };
 188
 189 static const true_false_string tfs_dest_unreach = {
 190         "Destination Unreachable",
 191         "NOT Destination Unreachable"
 192 };
 193
 194 static const true_false_string tfs_split_horiz = {
 195         "Split Horizon concealed route",
 196         "NOT Split Horizon concealed route"
 197 };
 198
 199 static const true_false_string tfs_cap_leaf = {
 200         "Leaf",
 201         "NOT Leaf"
 202 };
 203 static const true_false_string tfs_cap_prune = {
 204         "Prune capable",
 205         "NOT Prune capable"
 206 };
 207 static const true_false_string tfs_cap_genid = {
 208         "Genid capable",
 209         "NOT Genid capable"
 210 };
 211 static const true_false_string tfs_cap_mtrace = {
 212         "Multicast Traceroute capable",
 213         "NOT Multicast Traceroute capable"
 214 };
 215 static const true_false_string tfs_cap_snmp = {
 216         "SNMP capable",
 217         "NOT SNMP capable"
 218 };
 219 static const true_false_string tfs_cap_netmask = {
 220         "Netmask capable",
 221         "NOT Netmask capable"
 222 };
 223
 224 int
 225 dissect_v3_report(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int offset)
 226 {
 227         guint8 m0,m1,m2,m3;
 228         guint8 s0,s1,s2,s3;
 229         guint8 metric;
 230         guint32 ip;
 231
 232         while (tvb_reported_length_remaining(tvb, offset) > 0) {
 233                 proto_tree *tree;
 234                 proto_item *item;
 235                 int old_offset = offset;
 236
 237                 item = proto_tree_add_item(parent_tree, hf_route,
 238                                 tvb, offset, -1, FALSE);
 239                 tree = proto_item_add_subtree(item, ett_route);
 240
 241                 m0 = 0xff;
 242                 /* read the mask */
 243                 m1 = tvb_get_guint8(tvb, offset);
 244                 m2 = tvb_get_guint8(tvb, offset+1);
 245                 m3 = tvb_get_guint8(tvb, offset+2);
 246
 247                 ip = m3;
 248                 ip = (ip<<8)|m2;
 249                 ip = (ip<<8)|m1;
 250                 ip = (ip<<8)|m0;
 251                 proto_tree_add_ipv4(tree, hf_netmask, tvb, offset, 3, ip);
 252
 253                 offset += 3;
 254
 255                 /* read every srcnet, metric  pairs */
 256                 do {
 257                         int old_offset = offset;
 258                         m0 = 0xff;
 259
 260                         s0 = 0;
 261                         s1 = 0;
 262                         s2 = 0;
 263                         s3 = 0;
 264
 265                         s0 = tvb_get_guint8(tvb, offset);
 266                         offset += 1;
 267                         if (m1) {
 268                                 s1 = tvb_get_guint8(tvb, offset);
 269                                 offset += 1;
 270                         }
 271                         if (m2) {
 272                                 s2 = tvb_get_guint8(tvb, offset);
 273                                 offset += 1;
 274                         }
 275                         if (m3) {
 276                                 s3 = tvb_get_guint8(tvb, offset);
 277                                 offset += 1;
 278                         }
 279
 280                         /* handle special case for default route V3/3.4.3 */
 281                         if ((!m1)&&(!m2)&&(!m3)&&(!s0)) {
 282                                 m0 = 0;
 283                         }
 284
 285                         ip = s3;
 286                         ip = (ip<<8)|s2;
 287                         ip = (ip<<8)|s1;
 288                         ip = (ip<<8)|s0;
 289                         proto_tree_add_ipv4_format(tree, hf_saddr, tvb,
 290                                 old_offset, offset-old_offset, ip,
 291                                 "%s %d.%d.%d.%d (netmask %d.%d.%d.%d)",
 292                                 m0?"Source Network":"Default Route",
 293                                 s0,s1,s2,s3,m0,m1,m2,m3);
 294
 295                         metric = tvb_get_guint8(tvb, offset);
 296                         proto_tree_add_uint(tree, hf_metric, tvb,
 297                                 offset, 1, metric&0x7f);
 298                         offset += 1;
 299
 300
 301                 } while (!(metric&0x80));
 302
 303                 proto_item_set_len(item, offset-old_offset);
 304         }
 305
 306         return offset;
 307 }
 308
 309 int
 310 dissect_dvmrp_v3(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int offset)
 311 {
 312         guint8 code,count;
 313
 314         /* version */
 315         proto_tree_add_uint(parent_tree, hf_version, tvb, 0, 0, 3);
 316
 317         /* type of command */
 318         proto_tree_add_uint(parent_tree, hf_type, tvb, offset, 1, 0x13);
 319         offset += 1;
 320
 321         /* code */
 322         code = tvb_get_guint8(tvb, offset);
 323         proto_tree_add_uint(parent_tree, hf_code_v3, tvb, offset, 1, code);
 324         offset += 1;
 325         if (check_col(pinfo->cinfo, COL_INFO)) {
 326                 col_add_fstr(pinfo->cinfo, COL_INFO,
 327                         "V%d %s",3 ,val_to_str(code, code_v3,
 328                                 "Unknown Type:0x%02x"));
 329         }
 330
 331         /* checksum */
 332         igmp_checksum(parent_tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 0);
 333         offset += 2;
 334
 335         /* skip unused byte */
 336         offset += 1;
 337
 338         /* PROBE and NEIGHBORS 2 packets have capabilities flags, unused
 339            for other packets */
 340         if (code==DVMRP_V3_PROBE || code==DVMRP_V3_NEIGHBORS_2) {
 341                 proto_tree *tree;
 342                 proto_item *item;
 343
 344                 item = proto_tree_add_item(parent_tree, hf_capabilities,
 345                                 tvb, offset, 1, FALSE);
 346                 tree = proto_item_add_subtree(item, ett_capabilities);
 347
 348                 count = tvb_get_guint8(tvb, offset);
 349                 proto_tree_add_boolean(tree, hf_cap_netmask, tvb, offset, 1, count);
 350                 proto_tree_add_boolean(tree, hf_cap_snmp, tvb, offset, 1, count);
 351                 proto_tree_add_boolean(tree, hf_cap_mtrace, tvb, offset, 1, count);
 352                 proto_tree_add_boolean(tree, hf_cap_genid, tvb, offset, 1, count);
 353                 proto_tree_add_boolean(tree, hf_cap_prune, tvb, offset, 1, count);
 354                 proto_tree_add_boolean(tree, hf_cap_leaf, tvb, offset, 1, count);
 355         }
 356         offset += 1;
 357
 358         /* minor version */
 359         proto_tree_add_item(parent_tree, hf_min_ver, tvb, offset, 1, FALSE);
 360         offset += 1;
 361
 362         /* major version */
 363         proto_tree_add_item(parent_tree, hf_maj_ver, tvb, offset, 1, FALSE);
 364         offset += 1;
 365
 366         switch (code) {
 367         case DVMRP_V3_PROBE:
 368                 /* generation id */
 369                 proto_tree_add_item(parent_tree, hf_genid, tvb,
 370                         offset, 4, FALSE);
 371                 offset += 4;
 372                 while (tvb_reported_length_remaining(tvb, offset) > 0) {
 373                         proto_tree_add_item(parent_tree, hf_neighbor,
 374                                 tvb, offset, 4, FALSE);
 375                         offset += 4;
 376                 }
 377                 break;
 378         case DVMRP_V3_REPORT:
 379                 offset = dissect_v3_report(tvb, pinfo, parent_tree, offset);
 380                 break;
 381         case DVMRP_V3_PRUNE:
 382                 /* source address */
 383                 proto_tree_add_item(parent_tree, hf_saddr,
 384                         tvb, offset, 4, FALSE);
 385                 offset += 4;
 386                 /* group address */
 387                 proto_tree_add_item(parent_tree, hf_maddr,
 388                         tvb, offset, 4, FALSE);
 389                 offset += 4;
 390                 /* prune lifetime */
 391                 proto_tree_add_item(parent_tree, hf_life,
 392                         tvb, offset, 4, FALSE);
 393                 offset += 4;
 394                 /* source netmask */
 395                 if (tvb_reported_length_remaining(tvb, offset)>=4) {
 396                         proto_tree_add_item(parent_tree, hf_netmask,
 397                                 tvb, offset, 4, FALSE);
 398                         offset += 4;
 399                 }
 400                 break;
 401         case DVMRP_V3_GRAFT:
 402                 /* source address */
 403                 proto_tree_add_item(parent_tree, hf_saddr,
 404                         tvb, offset, 4, FALSE);
 405                 offset += 4;
 406                 /* group address */
 407                 proto_tree_add_item(parent_tree, hf_maddr,
 408                         tvb, offset, 4, FALSE);
 409                 offset += 4;
 410                 /* source netmask */
 411                 if (tvb_reported_length_remaining(tvb, offset)>=4) {
 412                         proto_tree_add_item(parent_tree, hf_netmask,
 413                                 tvb, offset, 4, FALSE);
 414                         offset += 4;
 415                 }
 416                 break;
 417         case DVMRP_V3_GRAFT_ACK:
 418                 /* source address */
 419                 proto_tree_add_item(parent_tree, hf_saddr,
 420                         tvb, offset, 4, FALSE);
 421                 offset += 4;
 422                 /* group address */
 423                 proto_tree_add_item(parent_tree, hf_maddr,
 424                         tvb, offset, 4, FALSE);
 425                 offset += 4;
 426                 /* source netmask */
 427                 if (tvb_reported_length_remaining(tvb, offset)>=4) {
 428                         proto_tree_add_item(parent_tree, hf_netmask,
 429                                 tvb, offset, 4, FALSE);
 430                         offset += 4;
 431                 }
 432                 break;
 433         case DVMRP_V3_ASK_NEIGHBORS:
 434         case DVMRP_V3_NEIGHBORS:
 435                 /* XXX - obsolete, and the draft doesn't describe them */
 436                 break;
 437         case DVMRP_V3_ASK_NEIGHBORS_2:
 438                 /* No data */
 439                 break;
 440         case DVMRP_V3_NEIGHBORS_2:
 441                 /* XXX - fill this in */
 442                 break;
 443         }
 444
 445         return offset;
 446 }
 447
 448
 449 int
 450 dissect_dvmrp_v1(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int offset)
 451 {
 452         guint8 code;
 453         guint8 af=2; /* default */
 454
 455         /* version */
 456         proto_tree_add_uint(parent_tree, hf_version, tvb, 0, 0, 1);
 457
 458         /* type of command */
 459         proto_tree_add_uint(parent_tree, hf_type, tvb, offset, 1, 0x13);
 460         offset += 1;
 461
 462         /* code */
 463         code = tvb_get_guint8(tvb, offset);
 464         proto_tree_add_uint(parent_tree, hf_code_v1, tvb, offset, 1, code);
 465         offset += 1;
 466         if (check_col(pinfo->cinfo, COL_INFO)) {
 467                 col_add_fstr(pinfo->cinfo, COL_INFO,
 468                         "V%d %s",1 ,val_to_str(code, code_v1,
 469                                 "Unknown Type:0x%02x"));
 470         }
 471
 472         /* checksum */
 473         igmp_checksum(parent_tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 0);
 474         offset += 2;
 475
 476         /* decode all the v1 commands */
 477         while (tvb_reported_length_remaining(tvb, offset)) {
 478                 proto_tree *tree;
 479                 proto_item *item;
 480                 guint8 cmd,count;
 481                 int old_offset = offset;
 482
 483                 item = proto_tree_add_item(parent_tree, hf_commands,
 484                                 tvb, offset, -1, FALSE);
 485                 tree = proto_item_add_subtree(item, ett_commands);
 486
 487                 cmd = tvb_get_guint8(tvb, offset);
 488                 proto_tree_add_uint(tree, hf_command, tvb,
 489                         offset, 1, cmd);
 490                 offset += 1;
 491
 492                 switch (cmd){
 493                 case V1_COMMAND_NULL:
 494                         offset += 1; /* skip ignored/pad byte*/
 495                         if (item) {
 496                                 proto_item_set_text(item, "Command: NULL");
 497                         }
 498                         break;
 499                 case V1_COMMAND_AFI:
 500                         af = tvb_get_guint8(tvb, offset);
 501                         proto_tree_add_uint(tree, hf_afi, tvb,
 502                                 offset, 1, af);
 503                         offset += 1;
 504                         if (item) {
 505                                 proto_item_set_text(item, "%s: %s",
 506                                         val_to_str(cmd, command, "Unknown Command:0x%02x"),
 507                                         val_to_str(af, afi, "Unknown Family:0x%02x")
 508                                 );
 509                         }
 510                         break;
 511                 case V1_COMMAND_SUBNETMASK:
 512                         count = tvb_get_guint8(tvb, offset);
 513                         proto_tree_add_uint(tree, hf_count, tvb,
 514                                 offset, 1, count);
 515                         offset += 1;
 516                         if (count) { /* must be 0 or 1 */
 517                                 proto_tree_add_item(tree, hf_netmask,
 518                                         tvb, offset, 4, FALSE);
 519                                 if (item) {
 520                                         proto_item_set_text(item, "%s: %d.%d.%d.%d",
 521                                                 val_to_str(cmd, command, "Unknown Command:0x%02x"),
 522                                                 tvb_get_guint8(tvb, offset),
 523                                                 tvb_get_guint8(tvb, offset+1),
 524                                                 tvb_get_guint8(tvb, offset+2),
 525                                                 tvb_get_guint8(tvb, offset+3));
 526                                 }
 527                                 offset += 4;
 528                         } else {
 529                                 if (item) {
 530                                         proto_item_set_text(item, "%s: <no mask supplied>",
 531                                                 val_to_str(cmd, command, "Unknown Command:0x%02x"));
 532                                 }
 533                         }
 534                         break;
 535                 case V1_COMMAND_METRIC:
 536                         proto_tree_add_item(tree, hf_metric, tvb,
 537                                 offset, 1, FALSE);
 538                         if (item) {
 539                                 proto_item_set_text(item, "%s: %d",
 540                                         val_to_str(cmd, command, "Unknown Command:0x%02x"),
 541                                         tvb_get_guint8(tvb, offset));
 542                         }
 543                         offset += 1;
 544                         break;
 545                 case V1_COMMAND_FLAGS0:
 546                         count = tvb_get_guint8(tvb, offset);
 547                         proto_tree_add_boolean(tree, hf_dest_unr, tvb, offset, 1, count);
 548                         proto_tree_add_boolean(tree, hf_split_horiz, tvb, offset, 1, count);
 549                         if (item) {
 550                                 proto_item_set_text(item, "%s: 0x%02x",
 551                                         val_to_str(cmd, command, "Unknown Command:0x%02x"), count);
 552                         }
 553                         offset += 1;
 554                         break;
 555                 case V1_COMMAND_INFINITY:
 556                         proto_tree_add_item(tree, hf_infinity, tvb,
 557                                 offset, 1, FALSE);
 558                         if (item) {
 559                                 proto_item_set_text(item, "%s: %d",
 560                                         val_to_str(cmd, command, "Unknown Command:0x%02x"), tvb_get_guint8(tvb, offset));
 561                         }
 562                         offset += 1;
 563                         break;
 564                 case V1_COMMAND_DA:
 565                 case V1_COMMAND_RDA: /* same as DA */
 566                         count = tvb_get_guint8(tvb, offset);
 567                         proto_tree_add_uint(tree, hf_count, tvb,
 568                                 offset, 1, count);
 569                         offset += 1;
 570                         while (count--) {
 571                                 proto_tree_add_item(tree, hf_daddr,
 572                                         tvb, offset, 4, FALSE);
 573                                 offset += 4;
 574                         }
 575                         if (item) {
 576                                 proto_item_set_text(item, "%s",
 577                                         val_to_str(cmd, command, "Unknown Command:0x%02x"));
 578                         }
 579                         break;
 580                 case V1_COMMAND_NMR:
 581                         count = tvb_get_guint8(tvb, offset);
 582                         proto_tree_add_uint(tree, hf_count, tvb,
 583                                 offset, 1, count);
 584                         offset += 1;
 585                         while (count--) {
 586                                 proto_tree_add_item(tree, hf_maddr,
 587                                         tvb, offset, 4, FALSE);
 588                                 offset += 4;
 589                                 proto_tree_add_item(tree, hf_hold, tvb,
 590                                         offset, 4, FALSE);
 591                                 offset += 4;
 592                         }
 593                         if (item) {
 594                                 proto_item_set_text(item, "%s",
 595                                         val_to_str(cmd, command, "Unknown Command:0x%02x"));
 596                         }
 597                         break;
 598                 case V1_COMMAND_NMR_CANCEL:
 599                         count = tvb_get_guint8(tvb, offset);
 600                         proto_tree_add_uint(tree, hf_count, tvb,
 601                                 offset, 1, count);
 602                         offset += 1;
 603                         while (count--) {
 604                                 proto_tree_add_item(tree, hf_maddr,
 605                                         tvb, offset, 4, FALSE);
 606                                 offset += 4;
 607                         }
 608                         if (item) {
 609                                 proto_item_set_text(item, "%s",
 610                                         val_to_str(cmd, command, "Unknown Command:0x%02x"));
 611                         }
 612                         break;
 613                 }
 614
 615                 proto_item_set_len(item, offset-old_offset);
 616         }
 617
 618         return offset;
 619 }
 620
 621 /* This function is only called from the IGMP dissector */
 622 int
 623 dissect_dvmrp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree, int offset)
 624 {
 625         proto_tree *tree;
 626         proto_item *item;
 627
 628         if (!proto_is_protocol_enabled(proto_dvmrp)) {
 629                 /* we are not enabled, skip entire packet to be nice
 630                    to the igmp layer. (so clicking on IGMP will display the data)
 631                  */
 632                 return offset+tvb_length_remaining(tvb, offset);
 633         }
 634
 635         item = proto_tree_add_item(parent_tree, proto_dvmrp, tvb, offset, -1, FALSE);
 636         tree = proto_item_add_subtree(item, ett_dvmrp);
 637
 638
 639         if (check_col(pinfo->cinfo, COL_PROTOCOL)) {
 640                 col_set_str(pinfo->cinfo, COL_PROTOCOL, "DVMRP");
 641         }
 642         if (check_col(pinfo->cinfo, COL_INFO)) {
 643                 col_clear(pinfo->cinfo, COL_INFO);
 644         }
 645
 646
 647         if ((tvb_length_remaining(tvb, offset)>=8)
 648          && (tvb_get_guint8(tvb, 6)==0xff)
 649          && (tvb_get_guint8(tvb, 7)==0x03)) {
 650                 offset = dissect_dvmrp_v3(tvb, pinfo, tree, offset);
 651                 proto_item_set_len(item, offset);
 652                 return offset;
 653         }
 654
 655
 656         offset = dissect_dvmrp_v1(tvb, pinfo, tree, offset);
 657         proto_item_set_len(item, offset);
 658         return offset;
 659 }
 660
 661 void
 662 proto_register_dvmrp(void)
 663 {
 664         static hf_register_info hf[] = {
 665                 { &hf_version,
 666                         { "DVMRP Version", "dvmrp.version", FT_UINT8, BASE_DEC,
 667                           NULL, 0, "DVMRP Version", HFILL }},
 668
 669                 { &hf_type,
 670                         { "Type", "dvmrp.type", FT_UINT8, BASE_HEX,
 671                           VALS(dvmrp_type), 0, "DVMRP Packet Type", HFILL }},
 672
 673                 { &hf_code_v1,
 674                         { "Code", "dvmrp.v1.code", FT_UINT8, BASE_HEX,
 675                           VALS(code_v1), 0, "DVMRP Packet Code", HFILL }},
 676
 677                 { &hf_checksum,
 678                         { "Checksum", "dvmrp.checksum", FT_UINT16, BASE_HEX,
 679                           NULL, 0, "DVMRP Checksum", HFILL }},
 680
 681                 { &hf_checksum_bad,
 682                         { "Bad Checksum", "dvmrp.checksum_bad", FT_BOOLEAN, BASE_NONE,
 683                           NULL, 0, "Bad DVMRP Checksum", HFILL }},
 684
 685                 { &hf_commands,
 686                         { "Commands", "dvmrp.commands", FT_NONE, BASE_NONE,
 687                           NULL, 0, "DVMRP V1 Commands", HFILL }},
 688
 689                 { &hf_command,
 690                         { "Command", "dvmrp.command", FT_UINT8, BASE_HEX,
 691                           VALS(command), 0, "DVMRP V1 Command", HFILL }},
 692
 693                 { &hf_afi,
 694                         { "Address Family", "dvmrp.afi", FT_UINT8, BASE_HEX,
 695                           VALS(afi), 0, "DVMRP Address Family Indicator", HFILL }},
 696
 697                 { &hf_count,
 698                         { "Count", "dvmrp.count", FT_UINT8, BASE_HEX,
 699                           NULL, 0, "Count", HFILL }},
 700
 701                 { &hf_netmask,
 702                         { "Netmask", "igmp.netmask", FT_IPv4, BASE_NONE,
 703                           NULL, 0, "DVMRP Netmask", HFILL }},
 704
 705                 { &hf_metric,
 706                         { "Metric", "dvmrp.metric", FT_UINT8, BASE_DEC,
 707                           NULL, 0, "DVMRP Metric", HFILL }},
 708
 709                 {&hf_dest_unr,
 710                         { "Destination Unreachable", "dvmrp.dest_unreach", FT_BOOLEAN, 8,
 711                         TFS(&tfs_dest_unreach), 0x01, "Destination Unreachable", HFILL }},
 712
 713                 {&hf_split_horiz,
 714                         { "Split Horizon", "dvmrp.split_horiz", FT_BOOLEAN, 8,
 715                         TFS(&tfs_split_horiz), 0x02, "Split Horizon concealed route", HFILL }},
 716
 717                 { &hf_infinity,
 718                         { "Infinity", "dvmrp.infinity", FT_UINT8, BASE_DEC,
 719                           NULL, 0, "DVMRP Infinity", HFILL }},
 720
 721                 { &hf_daddr,
 722                         { "Dest Addr", "igmp.daddr", FT_IPv4, BASE_NONE,
 723                           NULL, 0, "DVMRP Destination Address", HFILL }},
 724
 725                 { &hf_maddr,
 726                         { "Multicast Addr", "igmp.maddr", FT_IPv4, BASE_NONE,
 727                           NULL, 0, "DVMRP Multicast Address", HFILL }},
 728
 729                 { &hf_hold,
 730                         { "Hold Time", "dvmrp.hold", FT_UINT32, BASE_DEC,
 731                           NULL, 0, "DVMRP Hold Time in seconds", HFILL }},
 732
 733                 { &hf_code_v3,
 734                         { "Code", "dvmrp.v3.code", FT_UINT8, BASE_HEX,
 735                           VALS(code_v3), 0, "DVMRP Packet Code", HFILL }},
 736
 737                 { &hf_capabilities,
 738                         { "Capabilities", "dvmrp.capabilities", FT_NONE, BASE_NONE,
 739                           NULL, 0, "DVMRP V3 Capabilities", HFILL }},
 740
 741                 {&hf_cap_leaf,
 742                         { "Leaf", "dvmrp.cap.leaf", FT_BOOLEAN, 8,
 743                         TFS(&tfs_cap_leaf), DVMRP_V3_CAP_LEAF, "Leaf", HFILL }},
 744
 745                 {&hf_cap_prune,
 746                         { "Prune", "dvmrp.cap.prune", FT_BOOLEAN, 8,
 747                         TFS(&tfs_cap_prune), DVMRP_V3_CAP_PRUNE, "Prune capability", HFILL }},
 748
 749                 {&hf_cap_genid,
 750                         { "Genid", "dvmrp.cap.genid", FT_BOOLEAN, 8,
 751                         TFS(&tfs_cap_genid), DVMRP_V3_CAP_GENID, "Genid capability", HFILL }},
 752
 753                 {&hf_cap_mtrace,
 754                         { "Mtrace", "dvmrp.cap.mtrace", FT_BOOLEAN, 8,
 755                         TFS(&tfs_cap_mtrace), DVMRP_V3_CAP_MTRACE, "Mtrace capability", HFILL }},
 756
 757                 {&hf_cap_snmp,
 758                         { "SNMP", "dvmrp.cap.snmp", FT_BOOLEAN, 8,
 759                         TFS(&tfs_cap_snmp), DVMRP_V3_CAP_SNMP, "SNMP capability", HFILL }},
 760
 761                 {&hf_cap_netmask,
 762                         { "Netmask", "dvmrp.cap.netmask", FT_BOOLEAN, 8,
 763                         TFS(&tfs_cap_netmask), DVMRP_V3_CAP_NETMASK, "Netmask capability", HFILL }},
 764
 765                 { &hf_min_ver,
 766                         { "Minor Version", "dvmrp.min_ver", FT_UINT8, BASE_HEX,
 767                           NULL, 0, "DVMRP Minor Version", HFILL }},
 768
 769                 { &hf_maj_ver,
 770                         { "Major Version", "dvmrp.maj_ver", FT_UINT8, BASE_HEX,
 771                           NULL, 0, "DVMRP Major Version", HFILL }},
 772
 773                 { &hf_genid,
 774                         { "Generation ID", "dvmrp.genid", FT_UINT32, BASE_DEC,
 775                           NULL, 0, "DVMRP Generation ID", HFILL }},
 776
 777                 { &hf_route,
 778                         { "Route", "dvmrp.route", FT_NONE, BASE_NONE,
 779                           NULL, 0, "DVMRP V3 Route Report", HFILL }},
 780
 781                 { &hf_saddr,
 782                         { "Source Addr", "igmp.saddr", FT_IPv4, BASE_NONE,
 783                           NULL, 0, "DVMRP Source Address", HFILL }},
 784
 785                 { &hf_life,
 786                         { "Prune lifetime", "dvmrp.lifetime", FT_UINT32, BASE_DEC,
 787                           NULL, 0, "DVMRP Prune Lifetime", HFILL }},
 788
 789                 { &hf_neighbor,
 790                         { "Neighbor Addr", "igmp.neighbor", FT_IPv4, BASE_NONE,
 791                           NULL, 0, "DVMRP Neighbor Address", HFILL }},
 792
 793         };
 794         static gint *ett[] = {
 795                 &ett_dvmrp,
 796                 &ett_commands,
 797                 &ett_capabilities,
 798                 &ett_route,
 799         };
 800
 801         proto_dvmrp = proto_register_protocol("Distance Vector Multicast Routing Protocol",
 802             "DVMRP", "dvmrp");
 803         proto_register_field_array(proto_dvmrp, hf, array_length(hf));
 804         proto_register_subtree_array(ett, array_length(ett));
 805 }