packet-igmp.c

   1 /* packet-igmp.c   2001 Ronnie Sahlberg <See AUTHORS for email>
   2  * Routines for IGMP packet disassembly
   3  *
   4  * $Id$
   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         IGMP is defined in the following RFCs
  26         RFC988  Version 0       Obsolete
  27         RFC1054 Version 1
  28         RFC1112 Version 1       (same as RFC1054 as far as we are concerned)
  29         RFC2236 Version 2
  30         draft-ietf-idmr-igmp-v3-07      Version 3
  31
  32         Size in bytes for each packet
  33         type    RFC988  RFC1054 RFC2236 RFC????  DVMRP  MRDISC  MSNIP  IGAP
  34                 v0      v1      v2      v3       v1/v3
  35         0x01      20
  36         0x02      20
  37         0x03      20
  38         0x04      20
  39         0x05      20
  40         0x06      20
  41         0x07      20
  42         0x08      20
  43         0x11               8*     8*     >=12
  44         0x12               8*     8*
  45         0x13                                     x
  46         0x16                      8
  47         0x17                      8
  48         0x22                            >=8
  49         0x23                                                    >=8b
  50         0x24                                            >=8a    8b
  51         0x25                                            4a      >=8b
  52         0x26                                            4a
  53         0x40                                                           ??c
  54         0x41                                                           ??c
  55         0x42                                                           ??c
  56
  57    * Differs in second byte of protocol. Always 0 in V1
  58
  59
  60         Multicast traceroute was taken from
  61         draft-ietf-idmr-traceroute-ipm-07.txt
  62
  63         Size in bytes for each packet
  64         type    draft-ietf-idmr-traceroute-ipm-07.ps
  65         0x1e      24 + n*32
  66         0x1f      24 + n*32 (n == 0 for Query)
  67
  68    x DVMRP Protocol  see packet-dvmrp.c
  69
  70         DVMRP is defined in the following RFCs
  71         RFC1075 Version 1
  72         draft-ietf-idmr-dvmrp-v3-10.txt Version 3
  73
  74         V1 and V3 can be distinguished by looking at bytes 6 and 7 in the
  75         IGMP header.
  76         If header[6]==0xff and header[7]==0x03 we have version 3.
  77
  78    a MRDISC Protocol  see packet-mrdisc.c
  79
  80         MRDISC : IGMP Multicast Router DISCovery
  81         draft-ietf-idmr-igmp-mrdisc-06.txt
  82         TTL == 1 and IP.DST==224.0.0.2 for all packets
  83
  84    b MSNIP Protocol  see packet-msnip.c
  85
  86         MSNIP : Multicast Source Notification of Interest Protocol
  87         draft-ietf-idmr-msnip-00.txt
  88         0x23, 0x24 are sent with ip.dst==224.0.0.22
  89         0x25 is sent as unicast.
  90
  91    c IGAP Protocol  see packet-igap.c
  92
  93         IGAP : Internet Group membership Authentication Protocol
  94         draft-hayashi-igap-03.txt
  95
  96 */
  97
  98 #ifdef HAVE_CONFIG_H
  99 # include "config.h"
 100 #endif
 101
 102 #include <stdio.h>
 103 #include <string.h>
 104 #include <glib.h>
 105
 106 #ifdef NEED_SNPRINTF_H
 107 # include "snprintf.h"
 108 #endif
 109
 110 #include <epan/packet.h>
 111 #include "ipproto.h"
 112 #include "in_cksum.h"
 113 #include "packet-dvmrp.h"
 114 #include "packet-pim.h"
 115 #include "packet-mrdisc.h"
 116 #include "packet-msnip.h"
 117 #include "packet-igap.h"
 118
 119 static int proto_igmp = -1;
 120 static int hf_type = -1;
 121 static int hf_version = -1;
 122 static int hf_group_type = -1;
 123 static int hf_reply_code = -1;
 124 static int hf_reply_pending = -1;
 125 static int hf_checksum = -1;
 126 static int hf_checksum_bad = -1;
 127 static int hf_identifier = -1;
 128 static int hf_access_key = -1;
 129 static int hf_max_resp = -1;
 130 static int hf_max_resp_exp = -1;
 131 static int hf_max_resp_mant = -1;
 132 static int hf_supress = -1;
 133 static int hf_qrv = -1;
 134 static int hf_qqic = -1;
 135 static int hf_num_src = -1;
 136 static int hf_saddr = -1;
 137 static int hf_num_grp_recs = -1;
 138 static int hf_record_type = -1;
 139 static int hf_aux_data_len = -1;
 140 static int hf_maddr = -1;
 141 static int hf_aux_data = -1;
 142 static int hf_mtrace_max_hops = -1;
 143 static int hf_mtrace_saddr = -1;
 144 static int hf_mtrace_raddr = -1;
 145 static int hf_mtrace_rspaddr = -1;
 146 static int hf_mtrace_resp_ttl = -1;
 147 static int hf_mtrace_q_id = -1;
 148 static int hf_mtrace_q_arrival = -1;
 149 static int hf_mtrace_q_inaddr = -1;
 150 static int hf_mtrace_q_outaddr = -1;
 151 static int hf_mtrace_q_prevrtr = -1;
 152 static int hf_mtrace_q_inpkt = -1;
 153 static int hf_mtrace_q_outpkt = -1;
 154 static int hf_mtrace_q_total = -1;
 155 static int hf_mtrace_q_rtg_proto = -1;
 156 static int hf_mtrace_q_fwd_ttl = -1;
 157 static int hf_mtrace_q_mbz = -1;
 158 static int hf_mtrace_q_s = -1;
 159 static int hf_mtrace_q_src_mask = -1;
 160 static int hf_mtrace_q_fwd_code = -1;
 161
 162 static int ett_igmp = -1;
 163 static int ett_group_record = -1;
 164 static int ett_sqrv_bits = -1;
 165 static int ett_max_resp = -1;
 166 static int ett_mtrace_block = -1;
 167
 168 #define MC_ALL_ROUTERS          0xe0000002
 169 #define MC_ALL_IGMPV3_ROUTERS   0xe0000016
 170
 171
 172 #define IGMP_V0_CREATE_GROUP_REQUEST    0x01
 173 #define IGMP_V0_CREATE_GROUP_REPLY      0x02
 174 #define IGMP_V0_JOIN_GROUP_REQUEST      0x03
 175 #define IGMP_V0_JOIN_GROUP_REPLY        0x04
 176 #define IGMP_V0_LEAVE_GROUP_REQUEST     0x05
 177 #define IGMP_V0_LEAVE_GROUP_REPLY       0x06
 178 #define IGMP_V0_CONFIRM_GROUP_REQUEST   0x07
 179 #define IGMP_V0_CONFIRM_GROUP_REPLY     0x08
 180 #define IGMP_V1_HOST_MEMBERSHIP_QUERY   0x11
 181 #define IGMP_V1_HOST_MEMBERSHIP_REPORT  0x12
 182 #define IGMP_DVMRP                      0x13
 183 #define IGMP_V1_PIM_ROUTING_MESSAGE     0x14
 184 #define IGMP_V2_MEMBERSHIP_REPORT       0x16
 185 #define IGMP_V2_LEAVE_GROUP             0x17
 186 #define IGMP_TRACEROUTE_RESPONSE        0x1e
 187 #define IGMP_TRACEROUTE_QUERY_REQ       0x1f
 188 #define IGMP_V3_MEMBERSHIP_REPORT       0x22
 189 #define IGMP_TYPE_0x23                  0x23
 190 #define IGMP_TYPE_0x24                  0x24
 191 #define IGMP_TYPE_0x25                  0x25
 192 #define IGMP_TYPE_0x26                  0x26
 193
 194 #define IGMP_TRACEROUTE_HDR_LEN           24
 195 #define IGMP_TRACEROUTE_RSP_LEN           32
 196
 197 static const value_string commands[] = {
 198         {IGMP_V0_CREATE_GROUP_REQUEST,  "Create Group Request"          },
 199         {IGMP_V0_CREATE_GROUP_REPLY,    "Create Group Reply"            },
 200         {IGMP_V0_JOIN_GROUP_REQUEST,    "Join Group Request"            },
 201         {IGMP_V0_JOIN_GROUP_REPLY,      "Join Group Reply"              },
 202         {IGMP_V0_LEAVE_GROUP_REQUEST,   "Leave Group Request"           },
 203         {IGMP_V0_LEAVE_GROUP_REPLY,     "Leave Group Reply"             },
 204         {IGMP_V0_CONFIRM_GROUP_REQUEST, "Confirm Group Request"         },
 205         {IGMP_V0_CONFIRM_GROUP_REPLY,   "Confirm Group Reply"           },
 206         {IGMP_V1_HOST_MEMBERSHIP_QUERY, "Membership Query"              },
 207         {IGMP_V1_HOST_MEMBERSHIP_REPORT,"Membership Report"             },
 208         {IGMP_DVMRP,                    "DVMRP Protocol"                },
 209         {IGMP_V1_PIM_ROUTING_MESSAGE,   "PIM Routing Message"           },
 210         {IGMP_V2_MEMBERSHIP_REPORT,     "Membership Report"             },
 211         {IGMP_V2_LEAVE_GROUP,           "Leave Group"                   },
 212         {IGMP_TRACEROUTE_RESPONSE,      "Traceroute Response"           },
 213         {IGMP_TRACEROUTE_QUERY_REQ,     "Traceroute Query or Request"   },
 214         {IGMP_V3_MEMBERSHIP_REPORT,     "Membership Report"             },
 215         {0,             NULL}
 216 };
 217
 218 #define IGMP_V3_S               0x08
 219 #define IGMP_V3_QRV_MASK        0x07
 220
 221 #define IGMP_MAX_RESP_EXP       0x70
 222 #define IGMP_MAX_RESP_MANT      0x0f
 223
 224 #define IGMP_V0_GROUP_PUBLIC    0x00
 225 #define IGMP_V0_GROUP_PRIVATE   0x01
 226
 227 static const value_string vs_group_type[] = {
 228         {IGMP_V0_GROUP_PUBLIC,          "Public Group"                  },
 229         {IGMP_V0_GROUP_PRIVATE,         "Private Group"                 },
 230         {0,             NULL}
 231 };
 232
 233 #define IGMP_V0_REPLY_GRANTED   0x00
 234 #define IGMP_V0_REPLY_NO_RESOURCES      0x01
 235 #define IGMP_V0_REPLY_INVALID_CODE      0x02
 236 #define IGMP_V0_REPLY_INVALID_GROUP     0x03
 237 #define IGMP_V0_REPLY_INVALID_KEY       0x04
 238
 239 static const value_string vs_reply_code[] = {
 240         {IGMP_V0_REPLY_GRANTED, "Request Granted"       },
 241         {IGMP_V0_REPLY_NO_RESOURCES,    "Request Denied, No Resources"  },
 242         {IGMP_V0_REPLY_INVALID_CODE,    "Request Denied, Invalid Code"  },
 243         {IGMP_V0_REPLY_INVALID_GROUP,   "Request Denied, Invalid Group" },
 244         {IGMP_V0_REPLY_INVALID_KEY,     "Request Denied, Invalid Key"   },
 245         {0,             NULL}
 246 };
 247
 248 static const true_false_string tfs_s = {
 249         "SUPRESS router side processing",
 250         "Do not supress router side processing"
 251 };
 252
 253 #define IGMP_V3_MODE_IS_INCLUDE         1
 254 #define IGMP_V3_MODE_IS_EXCLUDE         2
 255 #define IGMP_V3_CHANGE_TO_INCLUDE_MODE  3
 256 #define IGMP_V3_CHANGE_TO_EXCLUDE_MODE  4
 257 #define IGMP_V3_ALLOW_NEW_SOURCES       5
 258 #define IGMP_V3_BLOCK_OLD_SOURCES       6
 259
 260 static const value_string vs_record_type[] = {
 261         {IGMP_V3_MODE_IS_INCLUDE,       "Mode Is Include"               },
 262         {IGMP_V3_MODE_IS_EXCLUDE,       "Mode Is Exclude"               },
 263         {IGMP_V3_CHANGE_TO_INCLUDE_MODE,"Change To Include Mode"        },
 264         {IGMP_V3_CHANGE_TO_EXCLUDE_MODE,"Change To Exclude Mode"        },
 265         {IGMP_V3_ALLOW_NEW_SOURCES,     "Allow New Sources"             },
 266         {IGMP_V3_BLOCK_OLD_SOURCES,     "Block Old Sources"             },
 267         { 0,    NULL}
 268 };
 269
 270 static const value_string mtrace_rtg_vals[] = {
 271         {1,  "DVMRP"                                        },
 272         {2,  "MOSPF"                                        },
 273         {3,  "PIM"                                          },
 274         {4,  "CBT"                                          },
 275         {5,  "PIM using special routing table"              },
 276         {6,  "PIM using a static route"                     },
 277         {7,  "DVMRP using a static route"                   },
 278         {8,  "PIM using MBGP (aka BGP4+) route"             },
 279         {9,  "CBT using special routing table"              },
 280         {10, "CBT using a static route"                     },
 281         {11, "PIM using state created by Assert processing" },
 282         {0,  NULL}
 283 };
 284
 285 static const value_string mtrace_fwd_code_vals[] = {
 286         {0x00, "NO_ERROR"       },
 287         {0x01, "WRONG_IF"       },
 288         {0x02, "PRUNE_SENT"     },
 289         {0x03, "PRUNE_RCVD"     },
 290         {0x04, "SCOPED"         },
 291         {0x05, "NO_ROUTE"       },
 292         {0x06, "WRONG_LAST_HOP" },
 293         {0x07, "NOT_FORWARDING" },
 294         {0x08, "REACHED_RP"     },
 295         {0x09, "RPF_IF"         },
 296         {0x0A, "NO_MULTICAST"   },
 297         {0x0B, "INFO_HIDDEN"    },
 298         {0x81, "NO_SPACE"       },
 299         {0x82, "OLD_ROUTER"     },
 300         {0x83, "ADMIN_PROHIB"   },
 301         {0, NULL}
 302 };
 303
 304 #define PRINT_IGMP_VERSION(version)                                     \
 305         if (check_col(pinfo->cinfo, COL_INFO)) {                        \
 306                 col_add_fstr(pinfo->cinfo, COL_INFO,                    \
 307                         "V%d %s",version,val_to_str(type, commands,     \
 308                                 "Unknown Type:0x%02x"));                \
 309         }                                                               \
 310         /* version of IGMP protocol */                                  \
 311         proto_tree_add_uint(tree, hf_version, tvb, 0, 0, version);      \
 312         /* type of command */                                           \
 313         proto_tree_add_uint(tree, hf_type, tvb, offset, 1, type);       \
 314         offset += 1;
 315
 316 void igmp_checksum(proto_tree *tree, tvbuff_t *tvb, int hf_index,
 317     int hf_index_bad, packet_info *pinfo, guint len)
 318 {
 319         guint16 cksum, hdrcksum;
 320         vec_t cksum_vec[1];
 321
 322         if (len == 0) {
 323                 /*
 324                  * Checksum the entire IGMP packet.
 325                  */
 326                 len = tvb_reported_length(tvb);
 327         }
 328
 329         hdrcksum = tvb_get_ntohs(tvb, 2);
 330         if (!pinfo->fragmented && tvb_length(tvb) >= len) {
 331                 /*
 332                  * The packet isn't part of a fragmented datagram and isn't
 333                  * truncated, so we can checksum it.
 334                  */
 335                 cksum_vec[0].ptr = tvb_get_ptr(tvb, 0, len);
 336                 cksum_vec[0].len = len;
 337
 338                 cksum = in_cksum(&cksum_vec[0],1);
 339
 340                 if (cksum == 0) {
 341                         proto_tree_add_uint_format(tree, hf_index,
 342                             tvb, 2, 2, hdrcksum,
 343                             "Header checksum: 0x%04x (correct)", hdrcksum);
 344                 } else {
 345                         proto_tree_add_boolean_hidden(tree, hf_index_bad,
 346                             tvb, 2, 2, TRUE);
 347                         proto_tree_add_uint_format(tree, hf_index,
 348                             tvb, 2, 2, hdrcksum,
 349                             "Header checksum: 0x%04x (incorrect, should be 0x%04x)", hdrcksum,in_cksum_shouldbe(hdrcksum,cksum));
 350                 }
 351         } else
 352                 proto_tree_add_uint(tree, hf_index, tvb, 2, 2, hdrcksum);
 353
 354         return;
 355 }
 356
 357
 358 /* Unknown IGMP message type */
 359 static int
 360 dissect_igmp_unknown(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int type, int offset)
 361 {
 362         int len;
 363
 364         if (check_col(pinfo->cinfo, COL_INFO)) {
 365                 col_add_str(pinfo->cinfo, COL_INFO,
 366                         val_to_str(type, commands, "Unknown Type:0x%02x"));
 367         }
 368
 369         /* type of command */
 370         proto_tree_add_uint(tree, hf_type, tvb, offset, 1, type);
 371         offset += 1;
 372
 373         /* Just call the rest of it "data" */
 374         len = tvb_length_remaining(tvb, offset);
 375         proto_tree_add_text(tree, tvb, offset, len, "Data");
 376         offset += len;
 377
 378         return offset;
 379 }
 380
 381
 382
 383 /*************************************************************
 384  * IGMP Protocol dissectors
 385  *************************************************************/
 386 static int
 387 dissect_v3_max_resp(tvbuff_t *tvb, proto_tree *parent_tree, int offset)
 388 {
 389         proto_tree *tree;
 390         proto_item *item;
 391         guint8 bits;
 392         guint32 tsecs;
 393
 394         bits = tvb_get_guint8(tvb, offset);
 395         if (bits&0x80) {
 396                 tsecs = ((bits&IGMP_MAX_RESP_MANT)|0x10);
 397                 tsecs = tsecs << ( ((bits&IGMP_MAX_RESP_EXP)>>4) + 3);
 398         } else {
 399                 tsecs = bits;
 400         }
 401
 402         item = proto_tree_add_uint_format(parent_tree, hf_max_resp, tvb,
 403                         offset, 1, tsecs, "Max Response Time: %.1f sec (0x%02x)",tsecs*0.1,bits);
 404
 405         if (bits&0x80) {
 406                 tree = proto_item_add_subtree(item, ett_max_resp);
 407
 408                 proto_tree_add_uint(tree, hf_max_resp_exp, tvb, offset, 1,
 409                         bits);
 410                 proto_tree_add_uint(tree, hf_max_resp_mant, tvb, offset, 1,
 411                         bits);
 412         }
 413
 414         offset += 1;
 415
 416         return offset;
 417 }
 418
 419 static int
 420 dissect_v3_sqrv_bits(tvbuff_t *tvb, proto_tree *parent_tree, int offset)
 421 {
 422         proto_tree *tree;
 423         proto_item *item;
 424         guint8 bits;
 425
 426         bits = tvb_get_guint8(tvb, offset);
 427
 428         item = proto_tree_add_text(parent_tree, tvb, offset, 1,
 429                 "QRV=%d S=%s", bits&IGMP_V3_QRV_MASK,
 430                         (bits&IGMP_V3_S)?tfs_s.true_string:tfs_s.false_string);
 431         tree = proto_item_add_subtree(item, ett_sqrv_bits);
 432
 433         /* S flag */
 434         proto_tree_add_boolean(tree, hf_supress, tvb, offset, 1, bits);
 435         /* QRV */
 436         proto_tree_add_uint(tree, hf_qrv, tvb, offset, 1, bits);
 437         offset += 1;
 438
 439         return offset;
 440 }
 441
 442 static int
 443 dissect_v3_group_record(tvbuff_t *tvb, proto_tree *parent_tree, int offset)
 444 {
 445         proto_tree *tree;
 446         proto_item *item;
 447         int old_offset = offset;
 448         guint8  adl;
 449         guint16 num;
 450         guint32 ip;
 451
 452         tvb_memcpy(tvb, (guint8 *)&ip, offset+4, 4);
 453         item = proto_tree_add_text(parent_tree, tvb, offset, -1,
 454                 "Group Record : %s  %s",
 455                         ip_to_str((gchar*)&ip),
 456                         val_to_str(tvb_get_guint8(tvb, offset), vs_record_type,"")
 457                 );
 458         tree = proto_item_add_subtree(item, ett_group_record);
 459
 460         /* record type */
 461         proto_tree_add_item(tree, hf_record_type, tvb, offset, 1, FALSE);
 462         offset += 1;
 463
 464         /* aux data len */
 465         adl = tvb_get_guint8(tvb, offset);
 466         proto_tree_add_uint(tree, hf_aux_data_len, tvb, offset, 1, adl);
 467         offset += 1;
 468
 469         /*number of sources*/
 470         num = tvb_get_ntohs(tvb, offset);
 471         proto_tree_add_uint(tree, hf_num_src, tvb, offset, 2, num);
 472         offset += 2;
 473
 474         /* multicast address */
 475         proto_tree_add_item(tree, hf_maddr, tvb, offset, 4, FALSE);
 476         offset += 4;
 477
 478         /* source addresses */
 479         while(num--){
 480                 proto_tree_add_item(tree, hf_saddr, tvb, offset, 4, FALSE);
 481                 offset += 4;
 482         }
 483
 484         /* aux data */
 485         if(adl){
 486                 proto_tree_add_item(tree, hf_aux_data, tvb, offset, adl*4,
 487                     FALSE);
 488                 offset += adl*4;
 489         }
 490
 491         proto_item_set_len(item, offset-old_offset);
 492         return offset;
 493 }
 494
 495 /* dissectors for version 3, rfc???? */
 496 static int
 497 dissect_igmp_v3_response(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int type, int offset)
 498 {
 499         guint16 num;
 500
 501         PRINT_IGMP_VERSION(3);
 502
 503         /* skip reserved field*/
 504         offset += 1;
 505
 506         /* checksum */
 507         igmp_checksum(tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 0);
 508         offset += 2;
 509
 510         /* skip reserved field */
 511         offset += 2;
 512
 513         /* number of group records */
 514         num = tvb_get_ntohs(tvb, offset);
 515         proto_tree_add_uint(tree, hf_num_grp_recs, tvb, offset, 2, num);
 516         offset += 2;
 517
 518         while (num--) {
 519                 offset = dissect_v3_group_record(tvb, tree, offset);
 520         }
 521
 522         return offset;
 523 }
 524
 525 static int
 526 dissect_igmp_v3_query(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int type, int offset)
 527 {
 528         guint16 num;
 529
 530         PRINT_IGMP_VERSION(3);
 531
 532         num = tvb_get_ntohs(tvb, offset+9);
 533         /* max resp code */
 534         offset = dissect_v3_max_resp(tvb, tree, offset);
 535
 536         /* checksum */
 537         igmp_checksum(tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 0);
 538         offset += 2;
 539
 540         /* group address */
 541         proto_tree_add_item(tree, hf_maddr, tvb, offset, 4, FALSE);
 542         offset +=4;
 543
 544         /* bitmask for S and QRV */
 545         offset = dissect_v3_sqrv_bits(tvb, tree, offset);
 546
 547         /* qqic */
 548         proto_tree_add_item(tree, hf_qqic, tvb, offset, 1, FALSE);
 549         offset += 1;
 550
 551         /*number of sources*/
 552         proto_tree_add_uint(tree, hf_num_src, tvb, offset, 2, num);
 553         offset += 2;
 554
 555         while(num--){
 556                 proto_tree_add_item(tree, hf_saddr, tvb, offset, 4, FALSE);
 557                 offset += 4;
 558         }
 559
 560         return offset;
 561 }
 562
 563 /* dissector for version 2, rfc2236 */
 564 static int
 565 dissect_igmp_v2(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int type, int offset)
 566 {
 567         guint8 tsecs;
 568
 569         PRINT_IGMP_VERSION(2);
 570
 571         /* max resp time */
 572         tsecs = tvb_get_guint8(tvb, offset);
 573         proto_tree_add_uint_format(tree, hf_max_resp, tvb,
 574                 offset, 1, tsecs, "Max Response Time: %.1f sec (0x%02x)", tsecs*0.1,tsecs);
 575         offset += 1;
 576
 577         /* checksum */
 578         igmp_checksum(tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 8);
 579         offset += 2;
 580
 581         /* group address */
 582         proto_tree_add_item(tree, hf_maddr, tvb, offset, 4, FALSE);
 583         offset +=4;
 584
 585         return offset;
 586 }
 587
 588 /* dissector for version 1, rfc1054 */
 589 static int
 590 dissect_igmp_v1(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int type, int offset)
 591 {
 592         PRINT_IGMP_VERSION(1);
 593
 594         /* skip unused byte */
 595         offset += 1;
 596
 597         /* checksum */
 598         igmp_checksum(tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 8);
 599         offset += 2;
 600
 601         /* group address */
 602         proto_tree_add_item(tree, hf_maddr, tvb, offset, 4, FALSE);
 603         offset +=4;
 604
 605         return offset;
 606 }
 607
 608 /* dissector for version 0, rfc988 */
 609 static int
 610 dissect_igmp_v0(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int type, int offset)
 611 {
 612         unsigned char code;
 613
 614         PRINT_IGMP_VERSION(0);
 615
 616         /* Code */
 617         code = tvb_get_guint8(tvb, offset);
 618         if (type==IGMP_V0_CREATE_GROUP_REQUEST) {
 619                 proto_tree_add_uint(tree, hf_group_type, tvb, offset, 1, code);
 620         } else if (!(type&0x01)) {
 621                 if (code <5) {
 622                         proto_tree_add_uint(tree, hf_reply_code, tvb, offset, 1, code);
 623                 } else {
 624                         proto_tree_add_uint(tree, hf_reply_pending, tvb, offset, 1, code);
 625                 }
 626         }
 627         offset += 1;
 628
 629         /* checksum */
 630         igmp_checksum(tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 20);
 631         offset += 2;
 632
 633         /* identifier */
 634         proto_tree_add_item(tree, hf_identifier, tvb, offset, 4, FALSE);
 635         offset += 4;
 636
 637         /* group address */
 638         proto_tree_add_item(tree, hf_maddr, tvb, offset, 4, FALSE);
 639         offset +=4;
 640
 641         /* access key */
 642         proto_tree_add_item(tree, hf_access_key, tvb, offset, 8, FALSE);
 643         offset +=8;
 644
 645         return offset;
 646 }
 647
 648 /* dissector for multicast traceroute, rfc???? */
 649 static int
 650 dissect_igmp_mtrace(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int type, int offset)
 651 {
 652         char *typestr, *blocks = NULL;
 653         char buf[20];
 654
 655         /* All multicast traceroute packets (Query, Request and
 656          * Response) have the same fixed header. Request and Response
 657          * have one or more response data blocks following this fixed
 658          * header. Since Query and Request share the same IGMP type,
 659          * the method to differentiate between them is to check the
 660          * IGMP packet length. Queries are only
 661          * IGMP_TRACEROUTE_HDR_LEN bytes long.
 662          */
 663         if (type == IGMP_TRACEROUTE_RESPONSE) {
 664                 int i = (tvb_reported_length_remaining(tvb, offset) - IGMP_TRACEROUTE_HDR_LEN) / IGMP_TRACEROUTE_RSP_LEN;
 665                 snprintf(buf, sizeof buf, ", %d block%s", i, plurality(i, "", "s"));
 666                 typestr = "Traceroute Response";
 667                 blocks = buf;
 668         } else if (tvb_reported_length_remaining(tvb, offset) == IGMP_TRACEROUTE_HDR_LEN)
 669                 typestr = "Traceroute Query";
 670         else
 671                 typestr = "Traceroute Request";
 672
 673         if (check_col(pinfo->cinfo, COL_INFO)) {
 674                 col_set_str(pinfo->cinfo, COL_INFO, typestr);
 675                 if (blocks) col_append_str(pinfo->cinfo, COL_INFO, blocks);
 676         }
 677
 678         proto_tree_add_uint_format(tree, hf_type, tvb, offset, 1, type,
 679             "Type: %s (0x%02x)", typestr, type);
 680         offset += 1;
 681
 682         /* maximum number of hops that the requester wants to trace */
 683         proto_tree_add_item(tree, hf_mtrace_max_hops, tvb, offset, 1, FALSE);
 684         offset += 1;
 685
 686         /* checksum */
 687         igmp_checksum(tree, tvb, hf_checksum, hf_checksum_bad, pinfo, 0);
 688         offset += 2;
 689
 690         /* group address to be traced */
 691         proto_tree_add_item(tree, hf_maddr, tvb, offset, 4, FALSE);
 692         offset += 4;
 693
 694         /* address of multicast source for the path being traced */
 695         proto_tree_add_item(tree, hf_mtrace_saddr, tvb, offset, 4, FALSE);
 696         offset += 4;
 697
 698         /* address of multicast receiver for the path being traced */
 699         proto_tree_add_item(tree, hf_mtrace_raddr, tvb, offset, 4, FALSE);
 700         offset += 4;
 701
 702         /* address where the completed traceroute response packet gets sent */
 703         proto_tree_add_item(tree, hf_mtrace_rspaddr, tvb, offset, 4, FALSE);
 704         offset += 4;
 705
 706         /* for multicasted responses, TTL at which to multicast the response */
 707         proto_tree_add_item(tree, hf_mtrace_resp_ttl, tvb, offset, 1, FALSE);
 708         offset += 1;
 709
 710         /* unique identifier for this traceroute request (for e.g. duplicate/delay detection) */
 711         proto_tree_add_item(tree, hf_mtrace_q_id, tvb, offset, 3, FALSE);
 712         offset += 3;
 713
 714         /* If this was Query, we only had the fixed header */
 715         if (tvb_reported_length_remaining(tvb, offset) == 0)
 716                 return offset;
 717
 718         /* Loop through the response data blocks */
 719         while (tvb_reported_length_remaining(tvb, offset) >= IGMP_TRACEROUTE_RSP_LEN) {
 720                 proto_item *bi;
 721                 proto_tree *block_tree;
 722
 723                 bi = proto_tree_add_text(tree, tvb, offset, IGMP_TRACEROUTE_RSP_LEN,
 724                                          "Response data block: %s -> %s,  Proto: %s,  Forwarding Code: %s",
 725                                          ip_to_str(tvb_get_ptr(tvb, offset + 4, 4)),
 726                                          ip_to_str(tvb_get_ptr(tvb, offset + 8, 4)),
 727                                          val_to_str(tvb_get_guint8(tvb, offset + 28), mtrace_rtg_vals, "Unknown"),
 728                                          val_to_str(tvb_get_guint8(tvb, offset + 31), mtrace_fwd_code_vals, "Unknown"));
 729                 block_tree = proto_item_add_subtree(bi, ett_mtrace_block);
 730
 731                 /* Query Arrival Time */
 732                 proto_tree_add_item(block_tree, hf_mtrace_q_arrival, tvb, offset, 4, FALSE);
 733                 offset += 4;
 734
 735                 /* Incoming Interface Address */
 736                 proto_tree_add_item(block_tree, hf_mtrace_q_inaddr, tvb, offset, 4, FALSE);
 737                 offset += 4;
 738
 739                 /* Outgoing Interface Address */
 740                 proto_tree_add_item(block_tree, hf_mtrace_q_outaddr, tvb, offset, 4, FALSE);
 741                 offset += 4;
 742
 743                 /* Previous-Hop Router Address */
 744                 proto_tree_add_item(block_tree, hf_mtrace_q_prevrtr, tvb, offset, 4, FALSE);
 745                 offset += 4;
 746
 747                 /* Input packet count on incoming interface */
 748                 proto_tree_add_item(block_tree, hf_mtrace_q_inpkt, tvb, offset, 4, FALSE);
 749                 offset += 4;
 750
 751                 /* Output packet count on outgoing interface */
 752                 proto_tree_add_item(block_tree, hf_mtrace_q_outpkt, tvb, offset, 4, FALSE);
 753                 offset += 4;
 754
 755                 /* Total number of packets for this source-group pair */
 756                 proto_tree_add_item(block_tree, hf_mtrace_q_total, tvb, offset, 4, FALSE);
 757                 offset += 4;
 758
 759                 /* Routing protocol in use between this and previous-hop router */
 760                 proto_tree_add_item(block_tree, hf_mtrace_q_rtg_proto, tvb, offset, 1, FALSE);
 761                 offset += 1;
 762
 763                 /* TTL that a packet is required to be forwarded */
 764                 proto_tree_add_item(block_tree, hf_mtrace_q_fwd_ttl, tvb, offset, 1, FALSE);
 765                 offset += 1;
 766
 767                 /* Must be zeroed and ignored bit, S bit and src network mask length */
 768                 proto_tree_add_item(block_tree, hf_mtrace_q_mbz, tvb, offset, 1, FALSE);
 769                 proto_tree_add_item(block_tree, hf_mtrace_q_s, tvb, offset, 1, FALSE);
 770                 proto_tree_add_item(block_tree, hf_mtrace_q_src_mask, tvb, offset, 1, FALSE);
 771                 offset += 1;
 772
 773                 /* Forwarding information/error code */
 774                 proto_tree_add_item(block_tree, hf_mtrace_q_fwd_code, tvb, offset, 1, FALSE);
 775                 offset += 1;
 776         }
 777
 778
 779         return offset;
 780 }
 781
 782 static void
 783 dissect_igmp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *parent_tree)
 784 {
 785         proto_tree *tree;
 786         proto_item *item;
 787         int offset = 0;
 788         unsigned char type;
 789         guint32 dst;
 790
 791         item = proto_tree_add_item(parent_tree, proto_igmp, tvb, offset, -1, FALSE);
 792         tree = proto_item_add_subtree(item, ett_igmp);
 793
 794
 795         if (check_col(pinfo->cinfo, COL_PROTOCOL)) {
 796                 col_set_str(pinfo->cinfo, COL_PROTOCOL, "IGMP");
 797         }
 798         if (check_col(pinfo->cinfo, COL_INFO)) {
 799                 col_clear(pinfo->cinfo, COL_INFO);
 800         }
 801
 802
 803         type = tvb_get_guint8(tvb, offset);
 804
 805
 806         /* version 0 */
 807         if ((type&0xf0)==0){
 808                 offset = dissect_igmp_v0(tvb, pinfo, tree, type, offset);
 809         }
 810
 811
 812         switch (type) {
 813
 814         case IGMP_V1_HOST_MEMBERSHIP_QUERY:     /* 0x11 v1/v2/v3 */
 815                 if ( (pinfo->iplen-pinfo->iphdrlen)>=12 ) {
 816                         /* version 3 */
 817                         offset = dissect_igmp_v3_query(tvb, pinfo, tree, type, offset);
 818                 } else {
 819                         /* v1 and v2 differs in second byte of header */
 820                         if (tvb_get_guint8(tvb, offset+1)) {
 821                                 offset = dissect_igmp_v2(tvb, pinfo, tree, type, offset);
 822                         } else {
 823                                 offset = dissect_igmp_v1(tvb, pinfo, tree, type, offset);
 824                         }
 825                 }
 826                 break;
 827
 828         case IGMP_V1_HOST_MEMBERSHIP_REPORT:    /* 0x12  v1 only */
 829                 offset = dissect_igmp_v1(tvb, pinfo, tree, type, offset);
 830                 break;
 831
 832         case IGMP_DVMRP:
 833                 offset = dissect_dvmrp(tvb, pinfo, parent_tree, offset);
 834                 break;
 835
 836         case IGMP_V1_PIM_ROUTING_MESSAGE:
 837                 offset = dissect_pimv1(tvb, pinfo, parent_tree, offset);
 838                 break;
 839
 840         case IGMP_V2_MEMBERSHIP_REPORT:
 841         case IGMP_V2_LEAVE_GROUP:
 842                 offset = dissect_igmp_v2(tvb, pinfo, tree, type, offset);
 843                 break;
 844
 845         case IGMP_TRACEROUTE_RESPONSE:
 846         case IGMP_TRACEROUTE_QUERY_REQ:
 847                 offset = dissect_igmp_mtrace(tvb, pinfo, tree, type, offset);
 848                 break;
 849
 850         case IGMP_V3_MEMBERSHIP_REPORT:
 851                 offset = dissect_igmp_v3_response(tvb, pinfo, tree, type, offset);
 852                 break;
 853
 854         case IGMP_TYPE_0x23:
 855                 dst = g_htonl(MC_ALL_IGMPV3_ROUTERS);
 856                 if (!memcmp(pinfo->dst.data, &dst, 4)) {
 857                         offset = dissect_msnip(tvb, pinfo, parent_tree, offset);
 858                 }
 859                 break;
 860
 861         case IGMP_TYPE_0x24:
 862                 dst = g_htonl(MC_ALL_ROUTERS);
 863                 if (!memcmp(pinfo->dst.data, &dst, 4)) {
 864                         offset = dissect_mrdisc(tvb, pinfo, parent_tree, offset);
 865                 }
 866                 dst = g_htonl(MC_ALL_IGMPV3_ROUTERS);
 867                 if (!memcmp(pinfo->dst.data, &dst, 4)) {
 868                         offset = dissect_msnip(tvb, pinfo, parent_tree, offset);
 869                 }
 870                 break;
 871
 872         case IGMP_TYPE_0x25:
 873                 if ( (pinfo->iplen-pinfo->iphdrlen)>=8 ) {
 874                         /* if len of igmp packet>=8 we assume it is MSNIP */
 875                         offset = dissect_msnip(tvb, pinfo, parent_tree, offset);
 876                 } else {
 877                         /* ok its not MSNIP, check if it might be MRDISC */
 878                         dst = g_htonl(MC_ALL_ROUTERS);
 879                         if (!memcmp(pinfo->dst.data, &dst, 4)) {
 880                                 offset = dissect_mrdisc(tvb, pinfo, parent_tree, offset);
 881                         }
 882                 }
 883                 break;
 884
 885         case IGMP_TYPE_0x26:
 886                 dst = g_htonl(MC_ALL_ROUTERS);
 887                 if (!memcmp(pinfo->dst.data, &dst, 4)) {
 888                         offset = dissect_mrdisc(tvb, pinfo, parent_tree, offset);
 889                 }
 890                 break;
 891
 892         case IGMP_IGAP_JOIN:
 893         case IGMP_IGAP_QUERY:
 894         case IGMP_IGAP_LEAVE:
 895                 offset = dissect_igap(tvb, pinfo, parent_tree, offset);
 896                 break;
 897
 898         default:
 899                 offset = dissect_igmp_unknown(tvb, pinfo, tree, type, offset);
 900                 break;
 901         }
 902
 903
 904         proto_item_set_len(item, offset);
 905 }
 906
 907 void
 908 proto_register_igmp(void)
 909 {
 910         static hf_register_info hf[] = {
 911                 { &hf_type,
 912                         { "Type", "igmp.type", FT_UINT8, BASE_HEX,
 913                           VALS(commands), 0, "IGMP Packet Type", HFILL }},
 914
 915                 { &hf_version,
 916                         { "IGMP Version", "igmp.version", FT_UINT8, BASE_DEC,
 917                           NULL, 0, "IGMP Version", HFILL }},
 918
 919                 { &hf_group_type,
 920                         { "Type Of Group", "igmp.group_type", FT_UINT8, BASE_DEC,
 921                           VALS(vs_group_type), 0, "IGMP V0 Type Of Group", HFILL }},
 922
 923                 { &hf_reply_code,
 924                         { "Reply", "igmp.reply", FT_UINT8, BASE_DEC,
 925                           VALS(vs_reply_code), 0, "IGMP V0 Reply", HFILL }},
 926
 927                 { &hf_reply_pending,
 928                         { "Reply Pending", "igmp.reply.pending", FT_UINT8, BASE_DEC,
 929                           NULL, 0, "IGMP V0 Reply Pending, Retry in this many seconds", HFILL }},
 930
 931                 { &hf_checksum,
 932                         { "Checksum", "igmp.checksum", FT_UINT16, BASE_HEX,
 933                           NULL, 0, "IGMP Checksum", HFILL }},
 934
 935                 { &hf_checksum_bad,
 936                         { "Bad Checksum", "igmp.checksum_bad", FT_BOOLEAN, BASE_NONE,
 937                           NULL, 0, "Bad IGMP Checksum", HFILL }},
 938
 939                 { &hf_identifier,
 940                         { "Identifier", "igmp.identifier", FT_UINT32, BASE_DEC,
 941                           NULL, 0, "IGMP V0 Identifier", HFILL }},
 942
 943                 { &hf_access_key,
 944                         { "Access Key", "igmp.access_key", FT_BYTES, BASE_HEX,
 945                           NULL, 0, "IGMP V0 Access Key", HFILL }},
 946
 947                 { &hf_max_resp,
 948                         { "Max Resp Time", "igmp.max_resp", FT_UINT8, BASE_DEC,
 949                           NULL, 0, "Max Response Time", HFILL }},
 950
 951                 { &hf_supress,
 952                         { "S", "igmp.s", FT_BOOLEAN, 8,
 953                           TFS(&tfs_s), IGMP_V3_S, "Supress Router Side Processing", HFILL }},
 954
 955                 { &hf_qrv,
 956                         { "QRV", "igmp.qrv", FT_UINT8, BASE_DEC,
 957                         NULL, IGMP_V3_QRV_MASK, "Querier's Robustness Value", HFILL }},
 958
 959                 { &hf_qqic,
 960                         { "QQIC", "igmp.qqic", FT_UINT8, BASE_DEC,
 961                           NULL, 0, "Querier's Query Interval Code", HFILL }},
 962
 963                 { &hf_num_src,
 964                         { "Num Src", "igmp.num_src", FT_UINT16, BASE_DEC,
 965                           NULL, 0, "Number Of Sources", HFILL }},
 966
 967                 { &hf_saddr,
 968                         { "Source Address", "igmp.saddr", FT_IPv4, BASE_NONE,
 969                           NULL, 0, "Source Address", HFILL }},
 970
 971                 { &hf_num_grp_recs,
 972                         { "Num Group Records", "igmp.num_grp_recs", FT_UINT16, BASE_DEC,
 973                           NULL, 0, "Number Of Group Records", HFILL }},
 974
 975                 { &hf_record_type,
 976                         { "Record Type", "igmp.record_type", FT_UINT8, BASE_DEC,
 977                         VALS(vs_record_type), 0, "Record Type", HFILL }},
 978
 979                 { &hf_aux_data_len,
 980                         { "Aux Data Len", "igmp.aux_data_len", FT_UINT8, BASE_DEC,
 981                         NULL, 0, "Aux Data Len, In units of 32bit words", HFILL }},
 982
 983                 { &hf_maddr,
 984                         { "Multicast Address", "igmp.maddr", FT_IPv4, BASE_NONE,
 985                           NULL, 0, "Multicast Address", HFILL }},
 986
 987                 { &hf_aux_data,
 988                         { "Aux Data", "igmp.aux_data", FT_BYTES, BASE_HEX,
 989                           NULL, 0, "IGMP V3 Auxiliary Data", HFILL }},
 990
 991                 { &hf_max_resp_exp,
 992                         { "Exponent", "igmp.max_resp.exp", FT_UINT8, BASE_HEX,
 993                         NULL, IGMP_MAX_RESP_EXP, "Maxmimum Response Time, Exponent", HFILL }},
 994
 995                 { &hf_max_resp_mant,
 996                         { "Mantissa", "igmp.max_resp.mant", FT_UINT8, BASE_HEX,
 997                         NULL, IGMP_MAX_RESP_MANT, "Maxmimum Response Time, Mantissa", HFILL }},
 998
 999                 { &hf_mtrace_max_hops,
1000                         { "# hops", "igmp.mtrace.max_hops", FT_UINT8, BASE_DEC,
1001                         NULL, 0, "Maxmimum Number of Hops to Trace", HFILL }},
1002
1003                 { &hf_mtrace_saddr,
1004                         { "Source Address", "igmp.mtrace.saddr", FT_IPv4, BASE_NONE,
1005                           NULL, 0, "Multicast Source for the Path Being Traced", HFILL }},
1006
1007                 { &hf_mtrace_raddr,
1008                         { "Receiver Address", "igmp.mtrace.raddr", FT_IPv4, BASE_NONE,
1009                           NULL, 0, "Multicast Receiver for the Path Being Traced", HFILL }},
1010
1011                 { &hf_mtrace_rspaddr,
1012                         { "Response Address", "igmp.mtrace.rspaddr", FT_IPv4, BASE_NONE,
1013                           NULL, 0, "Destination of Completed Traceroute Response", HFILL }},
1014
1015                 { &hf_mtrace_resp_ttl,
1016                         { "Response TTL", "igmp.mtrace.resp_ttl", FT_UINT8, BASE_DEC,
1017                         NULL, 0, "TTL for Multicasted Responses", HFILL }},
1018
1019                 { &hf_mtrace_q_id,
1020                         { "Query ID", "igmp.mtrace.q_id", FT_UINT24, BASE_DEC,
1021                         NULL, 0, "Identifier for this Traceroute Request", HFILL }},
1022
1023                 { &hf_mtrace_q_arrival,
1024                         { "Query Arrival", "igmp.mtrace.q_arrival", FT_UINT32, BASE_DEC,
1025                         NULL, 0, "Query Arrival Time", HFILL }},
1026
1027                 { &hf_mtrace_q_inaddr,
1028                         { "In itf addr", "igmp.mtrace.q_inaddr", FT_IPv4, BASE_NONE,
1029                         NULL, 0, "Incoming Interface Address", HFILL }},
1030
1031                 { &hf_mtrace_q_outaddr,
1032                         { "Out itf addr", "igmp.mtrace.q_outaddr", FT_IPv4, BASE_NONE,
1033                         NULL, 0, "Outgoing Interface Address", HFILL }},
1034
1035                 { &hf_mtrace_q_prevrtr,
1036                         { "Previous rtr addr", "igmp.mtrace.q_prevrtr", FT_IPv4, BASE_NONE,
1037                         NULL, 0, "Previous-Hop Router Address", HFILL }},
1038
1039                 { &hf_mtrace_q_inpkt,
1040                         { "In pkts", "igmp.mtrace.q_inpkt", FT_UINT32, BASE_DEC,
1041                         NULL, 0, "Input packet count on incoming interface", HFILL }},
1042
1043                 { &hf_mtrace_q_outpkt,
1044                         { "Out pkts", "igmp.mtrace.q_outpkt", FT_UINT32, BASE_DEC,
1045                         NULL, 0, "Output packet count on outgoing interface", HFILL }},
1046
1047                 { &hf_mtrace_q_total,
1048                         { "S,G pkt count", "igmp.mtrace.q_total", FT_UINT32, BASE_DEC,
1049                         NULL, 0, "Total number of packets for this source-group pair", HFILL }},
1050
1051                 { &hf_mtrace_q_rtg_proto,
1052                         { "Rtg Protocol", "igmp.mtrace.q_rtg_proto", FT_UINT8, BASE_DEC,
1053                         VALS(&mtrace_rtg_vals), 0, "Routing protocol between this and previous hop rtr", HFILL }},
1054
1055                 { &hf_mtrace_q_fwd_ttl,
1056                         { "FwdTTL", "igmp.mtrace.q_fwd_ttl", FT_UINT8, BASE_DEC,
1057                         NULL, 0, "TTL required for forwarding", HFILL }},
1058
1059                 { &hf_mtrace_q_mbz,
1060                         { "MBZ", "igmp.mtrace.q_mbz", FT_UINT8, BASE_HEX,
1061                         NULL, 0x80, "Must be zeroed on transmission and ignored on reception", HFILL }},
1062
1063                 { &hf_mtrace_q_s,
1064                         { "S", "igmp.mtrace.q_s", FT_UINT8, BASE_HEX,
1065                         NULL, 0x40, "Set if S,G packet count is for source network", HFILL }},
1066
1067                 { &hf_mtrace_q_src_mask,
1068                         { "Src Mask", "igmp.mtrace.q_src_mask", FT_UINT8, BASE_HEX,
1069                         NULL, 0x3F, "Source mask length. 63 when forwarding on group state", HFILL }},
1070
1071                 { &hf_mtrace_q_fwd_code,
1072                         { "Forwarding Code", "igmp.mtrace.q_fwd_code", FT_UINT8, BASE_HEX,
1073                         VALS(&mtrace_fwd_code_vals), 0, "Forwarding information/error code", HFILL }},
1074
1075         };
1076         static gint *ett[] = {
1077                 &ett_igmp,
1078                 &ett_group_record,
1079                 &ett_sqrv_bits,
1080                 &ett_max_resp,
1081                 &ett_mtrace_block,
1082         };
1083
1084         proto_igmp = proto_register_protocol("Internet Group Management Protocol",
1085             "IGMP", "igmp");
1086         proto_register_field_array(proto_igmp, hf, array_length(hf));
1087         proto_register_subtree_array(ett, array_length(ett));
1088 }
1089
1090 void
1091 proto_reg_handoff_igmp(void)
1092 {
1093         dissector_handle_t igmp_handle;
1094
1095         igmp_handle = create_dissector_handle(dissect_igmp, proto_igmp);
1096         dissector_add("ip.proto", IP_PROTO_IGMP, igmp_handle);
1097 }