epan/dissectors/packet-msdp.c

   1 /* packet-msdp.c
   2  * Routines for Multicast Source Discovery Protocol (MSDP) dissection.
   3  * RFC 3618
   4  *
   5  * Copyright 2001, Heikki Vatiainen <hessu@cs.tut.fi>
   6  *
   7  * Wireshark - Network traffic analyzer
   8  * By Gerald Combs <gerald@wireshark.org>
   9  * Copyright 1998 Gerald Combs
  10  *
  11  * SPDX-License-Identifier: GPL-2.0-or-later
  12  */
  13
  14 #include "config.h"
  15
  16 #include <epan/packet.h>
  17 #include <epan/to_str.h>
  18 #include <epan/expert.h>
  19
  20 void proto_register_msdp(void);
  21 void proto_reg_handoff_msdp(void);
  22
  23 /* MSDP (Type-Length-Value) TLV types. The messages are a sequence of TLVs. */
  24 enum { MSDP_SA     = 1,
  25        MSDP_SA_REQ,
  26        MSDP_SA_RSP,
  27        MSDP_KEEP_ALIVE,
  28        MSDP_NOTIFICATION,  /* draft 10, but not RFC 3618 */
  29
  30        /* These are only assigned in MSDP spec. Their use is specified
  31         * elsewhere */
  32        MSDP_TRACE_IN_PROGRESS,
  33        MSDP_TRACE_REPLY
  34 };
  35
  36 static const value_string msdp_types[] = {
  37         { MSDP_SA,                "IPv4 Source-Active"           },
  38         { MSDP_SA_REQ,            "IPv4 Source-Active Request"   },
  39         { MSDP_SA_RSP,            "IPv4 Source-Active Response"  },
  40         { MSDP_KEEP_ALIVE,        "KeepAlive"                    },
  41         { MSDP_NOTIFICATION,      "Notification"                 },
  42
  43         { MSDP_TRACE_IN_PROGRESS, "MSDP traceroute in progress"  },
  44         { MSDP_TRACE_REPLY,       "MSDP traceroute reply"        },
  45         { 0, NULL },
  46 };
  47
  48
  49 /* Error codes */
  50 enum { MESSAGE_HEADER_ERROR = 1,
  51        SA_REQUEST_ERROR,
  52        SA_MESSAGE_SA_RESPONSE_ERROR,
  53        HOLD_TIMER_EXPIRED,
  54        FSM_ERROR,
  55        NOTIFICATION,
  56        CEASE
  57 };
  58
  59 static const value_string error_vals[] = {
  60         { MESSAGE_HEADER_ERROR,         "Message Header Error"         },
  61         { SA_REQUEST_ERROR,             "SA-Request Error"             },
  62         { SA_MESSAGE_SA_RESPONSE_ERROR, "SA-Message/SA-Response Error" },
  63         { HOLD_TIMER_EXPIRED,           "Hold Timer Expired"           },
  64         { FSM_ERROR,                    "Finite State Machine Error"   },
  65         { NOTIFICATION,                 "Notification"                 },
  66         { CEASE,                        "Cease"                        },
  67         { 0, NULL },
  68 };
  69
  70
  71 /* Message Header Error subcodes */
  72 static const value_string hdr_error_vals[] = {
  73         { 0, "Unspecific"         },
  74         { 2, "Bad Message Length" },
  75         { 3, "Bad Message Type"   },
  76         { 0, NULL },
  77 };
  78
  79 /* SA-Request Error subcodes (the O-bit is always clear) */
  80 static const value_string sa_req_error_vals[] = {
  81         { 0, "Unspecific"    },
  82         { 1, "Invalid Group" },
  83         { 0, NULL },
  84 };
  85
  86 /* SA-Message/SA-Response Error subcodes */
  87 static const value_string sa_msg_error_vals[] = {
  88         { 0, "Unspecific"                             },
  89         { 1, "Invalid Entry Count"                    },
  90         { 2, "Invalid RP Address"                     },
  91         { 3, "Invalid Group Address"                  },
  92         { 4, "Invalid Source Address"                 },
  93         { 5, "Invalid Sprefix Length"                 },
  94         { 6, "Looping SA (Self is RP)"                },
  95         { 7, "Unknown Encapsulation"                  },
  96         { 8, "Administrative Scope Boundary Violated" },
  97         { 0, NULL },
  98 };
  99
 100 /* Finite State Machine Error subcodes (the O-bit is always clear) */
 101 static const value_string fsm_error_vals[] = {
 102         { 0, "Unspecific"                        },
 103         { 1, "Unexpected Message Type FSM Error" },
 104         { 0, NULL },
 105 };
 106
 107 /*
 108  * Hold Timer Expired subcodes (the O-bit is always clear):
 109  * Notification subcodes (the O-bit is always clear):
 110  * Cease subcodes (the O-bit is always clear):
 111  *
 112  * These have only "Unspecific" specified.
 113  */
 114 static const value_string sa_unspec_error_vals[] = {
 115         { 0, "Unspecific" },
 116         { 0, NULL },
 117 };
 118
 119 #define MSDP_PORT  639
 120
 121 /* Initialize the protocol and registered fields */
 122 static int proto_msdp = -1;
 123 static int hf_msdp_type = -1;
 124 static int hf_msdp_length = -1;
 125
 126 static int hf_msdp_sa_entry_count = -1;
 127 static int hf_msdp_sa_rp_addr = -1;
 128 static int hf_msdp_sa_reserved = -1;
 129 static int hf_msdp_sa_sprefix_len = -1;
 130 static int hf_msdp_sa_group_addr = -1;
 131 static int hf_msdp_sa_src_addr = -1;
 132
 133 static int hf_msdp_sa_req_res = -1;
 134 static int hf_msdp_sa_req_group = -1;
 135
 136 static int hf_msdp_not_o = -1;
 137 static int hf_msdp_not_error = -1;
 138 static int hf_msdp_not_error_sub = -1;
 139
 140 static int hf_msdp_not_group_address = -1;
 141 static int hf_msdp_not_rp_address = -1;
 142 static int hf_msdp_not_source_address = -1;
 143 static int hf_msdp_not_res = -1;
 144 static int hf_msdp_not_entry_count = -1;
 145 static int hf_msdp_not_sprefix_len = -1;
 146
 147 static int hf_msdp_tlv_contents = -1;
 148 static int hf_msdp_trailing_junk = -1;
 149 static int hf_msdp_unknown_data = -1;
 150
 151 static gint ett_msdp = -1;
 152 static gint ett_msdp_sa_entry = -1;
 153 static gint ett_msdp_sa_enc_data = -1;
 154 static gint ett_msdp_not_data = -1;
 155
 156 static expert_field ei_msdp_tlv_len_too_short = EI_INIT;
 157 static expert_field ei_msdp_tlv_len_too_long = EI_INIT;
 158
 159 static dissector_handle_t ip_handle;
 160
 161
 162 static void
 163 dissect_msdp_sa(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
 164     int *offset, int length, proto_item *length_item);
 165 static void
 166 dissect_msdp_notification(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree,
 167     int *offset, guint16 tlv_len, proto_item *length_item);
 168
 169
 170 static int
 171 dissect_msdp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
 172 {
 173         proto_item *ti;
 174         proto_tree *msdp_tree;
 175         proto_item *length_item;
 176         int         offset;
 177         guint32     type;
 178         guint32     length;
 179
 180
 181         col_set_str(pinfo->cinfo, COL_PROTOCOL, "MSDP");
 182
 183         col_set_str(pinfo->cinfo, COL_INFO, val_to_str_const(tvb_get_guint8(tvb, 0),
 184                                                                      msdp_types,
 185                                                                      "<Unknown MSDP TLV type>"));
 186
 187         ti = proto_tree_add_item(tree, proto_msdp, tvb, 0, -1, ENC_NA);
 188         msdp_tree = proto_item_add_subtree(ti, ett_msdp);
 189
 190         offset = 0;
 191         while (tvb_reported_length_remaining(tvb, offset) != 0) {
 192                 proto_tree_add_item_ret_uint(msdp_tree, hf_msdp_type, tvb, offset, 1, ENC_BIG_ENDIAN, &type);
 193                 length_item = proto_tree_add_item_ret_uint(msdp_tree, hf_msdp_length, tvb, offset + 1, 2, ENC_BIG_ENDIAN, &length);
 194                 if (length < 3) {
 195                         expert_add_info_format(pinfo, length_item,
 196                             &ei_msdp_tlv_len_too_short,
 197                             "TLV length < 3");
 198                         break;
 199                 }
 200                 offset += 3;
 201                 length -= 3;
 202
 203                 switch (type) {
 204                 case MSDP_SA:
 205                         dissect_msdp_sa(tvb, pinfo, msdp_tree, &offset,
 206                                         length, length_item);
 207                         break;
 208                 case MSDP_SA_REQ:
 209                         /*
 210                          * This type is mentioned in the RFC but the format
 211                          * isn't described.
 212                          */
 213                         if (length < 1) {
 214                                 expert_add_info_format(pinfo, length_item,
 215                                     &ei_msdp_tlv_len_too_short,
 216                                     "TLV length for IPv4 Source-Active Request < 8");
 217                                 break;
 218                         }
 219                         proto_tree_add_item(msdp_tree, hf_msdp_sa_req_res, tvb, offset, 1, ENC_BIG_ENDIAN);
 220                         offset += 1;
 221                         length -= 1;
 222                         if (length < 4) {
 223                                 expert_add_info_format(pinfo, length_item,
 224                                     &ei_msdp_tlv_len_too_short,
 225                                     "TLV length for IPv4 Source-Active Request < 8");
 226                                 offset += length;
 227                                 break;
 228                         }
 229                         proto_tree_add_item(msdp_tree, hf_msdp_sa_req_group, tvb, offset, 4, ENC_BIG_ENDIAN);
 230                         offset += 4;
 231                         length -= 4;
 232                         if (length > 0) {
 233                                 expert_add_info_format(pinfo, length_item,
 234                                     &ei_msdp_tlv_len_too_long,
 235                                     "TLV length for KeepAlive > 8");
 236                                 proto_tree_add_item(tree, hf_msdp_trailing_junk, tvb, offset, length, ENC_NA);
 237                                 offset += length;
 238                         }
 239                         break;
 240                 case MSDP_SA_RSP:
 241                         /*
 242                          * This type is mentioned in the RFC but the format
 243                          * isn't described.
 244                          */
 245                         dissect_msdp_sa(tvb, pinfo, msdp_tree, &offset,
 246                                         length, length_item);
 247                         break;
 248                 case MSDP_KEEP_ALIVE:
 249                         if (length > 0) {
 250                                 expert_add_info_format(pinfo, length_item,
 251                                     &ei_msdp_tlv_len_too_long,
 252                                     "TLV length for KeepAlive > 3");
 253                                 proto_tree_add_item(tree, hf_msdp_trailing_junk, tvb, offset, length, ENC_NA);
 254                                 offset += length;
 255                         }
 256                         break;
 257                 case MSDP_NOTIFICATION:
 258                         /*
 259                          * This was in draft 10, but is reserved in the
 260                          * RFC.
 261                          */
 262                         dissect_msdp_notification(tvb, pinfo, msdp_tree, &offset, length, length_item);
 263                         break;
 264                 default:
 265                         if (length > 0)
 266                                 proto_tree_add_item(msdp_tree, hf_msdp_tlv_contents, tvb, offset, length, ENC_NA);
 267                         offset += length;
 268                         break;
 269                 }
 270         }
 271
 272         return tvb_captured_length(tvb);
 273 }
 274
 275 /* Both Source-Active and Source-Active Response have the same format
 276  * with one exception. Encapsulated multicast data is not allowed in
 277  * SA Response.
 278  */
 279 static void dissect_msdp_sa(tvbuff_t *tvb, packet_info *pinfo,
 280     proto_tree *tree, int *offset, int length, proto_item *length_item)
 281 {
 282         guint32 entries;
 283
 284         if (length < 1) {
 285                 expert_add_info_format(pinfo, length_item,
 286                     &ei_msdp_tlv_len_too_short,
 287                     "TLV length for IPv4 Source-Active or Source-Active Response < 5");
 288                 return;
 289         }
 290         proto_tree_add_item_ret_uint(tree, hf_msdp_sa_entry_count, tvb, *offset, 1, ENC_BIG_ENDIAN, &entries);
 291         *offset += 1;
 292         length -= 1;
 293
 294         if (length < 4) {
 295                 expert_add_info_format(pinfo, length_item,
 296                     &ei_msdp_tlv_len_too_short,
 297                     "TLV length for IPv4 Source-Active or Source-Active Response < 5");
 298                 *offset += length;
 299                 return;
 300         }
 301         proto_tree_add_item(tree, hf_msdp_sa_rp_addr, tvb, *offset, 4, ENC_BIG_ENDIAN);
 302         *offset += 4;
 303         length -= 4;
 304
 305         /* Put each of the (S,G) entries in their own subtree.
 306          * This is probably visually better.
 307          */
 308         while (entries-- > 0) {
 309                 proto_tree *entry_tree;
 310
 311                 if (length < 12) {
 312                         expert_add_info_format(pinfo, length_item,
 313                             &ei_msdp_tlv_len_too_short,
 314                             "TLV length for IPv4 Source-Active or Source-Active Response too short");
 315                         *offset += length;
 316                         return;
 317                 }
 318                 entry_tree = proto_tree_add_subtree_format(tree, tvb, *offset, 12, ett_msdp_sa_entry, NULL,
 319                                          "(S,G) block: %s/%u -> %s",
 320                                          tvb_ip_to_str(tvb, *offset + 8),
 321                                          tvb_get_guint8(tvb, *offset + 3),
 322                                          tvb_ip_to_str(tvb, *offset + 4));
 323
 324                 proto_tree_add_item(entry_tree, hf_msdp_sa_reserved, tvb, *offset, 3, ENC_BIG_ENDIAN);
 325                 *offset += 3;
 326                 length -= 3;
 327                 proto_tree_add_item(entry_tree, hf_msdp_sa_sprefix_len, tvb, *offset, 1, ENC_BIG_ENDIAN);
 328                 *offset += 1;
 329                 length -= 1;
 330                 proto_tree_add_item(entry_tree, hf_msdp_sa_group_addr, tvb, *offset, 4, ENC_BIG_ENDIAN);
 331                 *offset += 4;
 332                 length -= 4;
 333                 proto_tree_add_item(entry_tree, hf_msdp_sa_src_addr, tvb, *offset, 4, ENC_BIG_ENDIAN);
 334                 *offset += 4;
 335                 length -= 4;
 336         }
 337
 338         /*
 339          * Check if an encapsulated multicast IPv4 packet follows
 340          */
 341         if (length > 0) {
 342                 proto_tree *enc_tree;
 343                 gint reported_length;
 344                 tvbuff_t *next_tvb;
 345
 346                 enc_tree = proto_tree_add_subtree_format(tree, tvb, *offset, length,
 347                                          ett_msdp_sa_enc_data, NULL, "Encapsulated IPv4 packet: %u bytes",
 348                                          length);
 349
 350                 reported_length = tvb_reported_length_remaining(tvb, *offset);
 351                 DISSECTOR_ASSERT(reported_length >= 0);
 352                 if (reported_length > length)
 353                         reported_length = length;
 354
 355                 next_tvb = tvb_new_subset_length(tvb, *offset, reported_length);
 356                 /* Set the protocol and information columns read-only so
 357                  * that they reflect the MSDP packet rather than the
 358                  * encapsulated packet.
 359                  */
 360                 col_set_writable(pinfo->cinfo, COL_PROTOCOL, FALSE);
 361                 col_set_writable(pinfo->cinfo, COL_INFO, FALSE);
 362                 call_dissector(ip_handle, next_tvb, pinfo, enc_tree);
 363         }
 364         *offset += length;
 365
 366         return;
 367 }
 368
 369 /* Note: updates *offset */
 370 static void add_notification_data_ipv4addr(tvbuff_t *tvb, proto_tree *tree, int *offset, int hf_addr)
 371 {
 372         proto_tree_add_item(tree, hf_msdp_not_res, tvb, *offset, 3, ENC_BIG_ENDIAN);
 373         *offset += 3;
 374         proto_tree_add_item(tree, hf_addr, tvb, *offset, 4, ENC_BIG_ENDIAN);
 375         *offset += 4;
 376
 377         return;
 378 }
 379
 380 static void dissect_msdp_notification(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, int *offset, guint16 tlv_len, proto_item *length_item)
 381 {
 382         guint8              error, error_sub;
 383         const value_string *vals;
 384         gint reported_length;
 385         tvbuff_t *next_tvb;
 386
 387         if (tlv_len < 1) {
 388                 expert_add_info_format(pinfo, length_item,
 389                     &ei_msdp_tlv_len_too_short,
 390                     "TLV length for Notification < 4");
 391                 return;
 392         }
 393         proto_tree_add_item(tree, hf_msdp_not_o, tvb, *offset, 1, ENC_BIG_ENDIAN);
 394         proto_tree_add_item(tree, hf_msdp_not_error, tvb, *offset, 1, ENC_BIG_ENDIAN);
 395         error = tvb_get_guint8(tvb, *offset);
 396         error &= 0x7F;             /* Error is 7-bit field. O-bit is bit 8 */
 397         *offset += 1;
 398         tlv_len -= 1;
 399
 400         /* Depending on the Error Code, we collect the correct
 401          * value_strings for the Error subcode
 402          */
 403         switch (error) {
 404         case MESSAGE_HEADER_ERROR:
 405                 vals = hdr_error_vals;
 406                 break;
 407         case SA_REQUEST_ERROR:
 408                 vals = sa_req_error_vals;
 409                 break;
 410         case SA_MESSAGE_SA_RESPONSE_ERROR:
 411                 vals = sa_msg_error_vals;
 412                 break;
 413         case FSM_ERROR:
 414                 vals = fsm_error_vals;
 415                 break;
 416         case HOLD_TIMER_EXPIRED:
 417         case NOTIFICATION:
 418         case CEASE:
 419                 vals = sa_unspec_error_vals;
 420                 break;
 421         default:
 422                 vals = sa_unspec_error_vals;
 423                 break;
 424         }
 425
 426         if (tlv_len < 1) {
 427                 expert_add_info_format(pinfo, length_item,
 428                     &ei_msdp_tlv_len_too_short,
 429                     "TLV length for Notification < 5");
 430                 return;
 431         }
 432         error_sub = tvb_get_guint8(tvb, *offset);
 433         proto_tree_add_uint_format_value(tree, hf_msdp_not_error_sub, tvb, *offset, 1,
 434                                    error_sub, "%s (%u)",
 435                                    val_to_str_const(error_sub, vals, "<Unknown Error subcode>"),
 436                                    error_sub);
 437         *offset += 1;
 438         tlv_len -= 1;
 439
 440         /* Do switch again, this time to dissect the data portion
 441          * correctly. Ugly.
 442          */
 443         switch (error) {
 444         case SA_REQUEST_ERROR:
 445                 if (tlv_len < 7) {
 446                         expert_add_info_format(pinfo, length_item,
 447                             &ei_msdp_tlv_len_too_short,
 448                             "TLV length for Notification SA-Request Error < 12");
 449                         *offset += tlv_len;
 450                         return;
 451                 }
 452                 add_notification_data_ipv4addr(tvb, tree, offset, hf_msdp_not_group_address);
 453                 tlv_len -= 7;
 454                 break;
 455         case SA_MESSAGE_SA_RESPONSE_ERROR:
 456                 if (error_sub == 0) {
 457                         break;
 458                 } else if (error_sub == 1) {
 459                         if (tlv_len < 1) {
 460                                 expert_add_info_format(pinfo, length_item,
 461                                     &ei_msdp_tlv_len_too_short,
 462                                     "TLV length for Notification SA-Response Invalid Entry Count Error < 6");
 463                                 return;
 464                         }
 465                         proto_tree_add_item(tree, hf_msdp_not_entry_count, tvb, *offset, 1, ENC_BIG_ENDIAN);
 466                         *offset += 1;
 467                         tlv_len -= 1;
 468                         break;
 469                 } else if (error_sub == 2) {
 470                         if (tlv_len < 7) {
 471                                 expert_add_info_format(pinfo, length_item,
 472                                     &ei_msdp_tlv_len_too_short,
 473                                     "TLV length for Notification SA-Response Invalid RP Address Error < 12");
 474                                 *offset += tlv_len;
 475                                 return;
 476                         }
 477                         add_notification_data_ipv4addr(tvb, tree, offset, hf_msdp_not_rp_address);
 478                         tlv_len -= 7;
 479                         break;
 480                 } else if (error_sub == 3 || error_sub == 8) {
 481                         if (tlv_len < 7) {
 482                                 expert_add_info_format(pinfo, length_item,
 483                                     &ei_msdp_tlv_len_too_short,
 484                                     "TLV length for Notification SA-Response %s Error < 12",
 485                                     (error_sub == 3) ? "Invalid Group Address"
 486                                                      : "Administrative Scope Boundary Violated");
 487                                 *offset += tlv_len;
 488                                 return;
 489                         }
 490                         add_notification_data_ipv4addr(tvb, tree, offset, hf_msdp_not_group_address);
 491                         tlv_len -= 7;
 492                         break;
 493                 } else if (error_sub == 4) {
 494                         if (tlv_len < 7) {
 495                                 expert_add_info_format(pinfo, length_item,
 496                                     &ei_msdp_tlv_len_too_short,
 497                                     "TLV length for Notification SA-Response Invalid Source Address Error < 12");
 498                                 *offset += tlv_len;
 499                                 return;
 500                         }
 501                         add_notification_data_ipv4addr(tvb, tree, offset, hf_msdp_not_source_address);
 502                         tlv_len -= 7;
 503                         break;
 504                 } else if (error_sub == 5) {
 505                         if (tlv_len < 1) {
 506                                 expert_add_info_format(pinfo, length_item,
 507                                     &ei_msdp_tlv_len_too_short,
 508                                     "TLV length for Notification SA-Response Invalid Invalid Sprefix Length Error < 6");
 509                                 return;
 510                         }
 511                         proto_tree_add_item(tree, hf_msdp_not_sprefix_len, tvb, *offset, 1, ENC_BIG_ENDIAN);
 512                         *offset += 1;
 513                         tlv_len -= 1;
 514                         break;
 515                 } else if (error_sub == 6) {
 516                         if (tlv_len > 0) {
 517                                 reported_length = tvb_reported_length_remaining(tvb, *offset);
 518                                 DISSECTOR_ASSERT(reported_length >= 0);
 519                                 if (reported_length > tlv_len)
 520                                         reported_length = tlv_len;
 521                                 next_tvb = tvb_new_subset_length(tvb, *offset, reported_length);
 522                                 dissect_msdp(next_tvb, pinfo, tree, NULL);
 523                         }
 524                         *offset += tlv_len;
 525                         tlv_len = 0;
 526                 } else if (error_sub == 7) {
 527                         if (tlv_len > 0) {
 528                                 reported_length = tvb_reported_length_remaining(tvb, *offset);
 529                                 DISSECTOR_ASSERT(reported_length >= 0);
 530                                 if (reported_length > tlv_len)
 531                                         reported_length = tlv_len;
 532                                 next_tvb = tvb_new_subset_length(tvb, *offset, reported_length);
 533                                 dissect_msdp(next_tvb, pinfo, tree, NULL);
 534                         }
 535                         *offset += tlv_len;
 536                         tlv_len = 0;
 537                         break;
 538                 } else {
 539                         if (tlv_len > 0)
 540                                 proto_tree_add_item(tree, hf_msdp_unknown_data, tvb, *offset, tlv_len, ENC_NA);
 541                         *offset += tlv_len;
 542                         tlv_len = 0;
 543                         break;
 544                 }
 545                 break;
 546         case MESSAGE_HEADER_ERROR:
 547         case NOTIFICATION:
 548                 /* Data contains the message that had an error. Even a
 549                  * broken Notification message causes a Notification
 550                  * message with Error Code set to Notification to be
 551                  * sent back.
 552                  */
 553                 if (tlv_len > 0) {
 554                         reported_length = tvb_reported_length_remaining(tvb, *offset);
 555                         DISSECTOR_ASSERT(reported_length >= 0);
 556                         if (reported_length > tlv_len)
 557                                 reported_length = tlv_len;
 558                         next_tvb = tvb_new_subset_length(tvb, *offset, reported_length);
 559                         dissect_msdp(next_tvb, pinfo, tree, NULL);
 560                 }
 561                 *offset += tlv_len;
 562                 tlv_len = 0;
 563                 break;
 564         case FSM_ERROR:
 565         case HOLD_TIMER_EXPIRED:
 566         case CEASE:
 567                 /* Do nothing. These contain no data */
 568                 break;
 569         default:
 570                 if (tlv_len > 0)
 571                         proto_tree_add_item(tree, hf_msdp_unknown_data, tvb, *offset, tlv_len, ENC_NA);
 572                 *offset += tlv_len;
 573                 tlv_len = 0;
 574                 break;
 575         }
 576         if (tlv_len != 0) {
 577                 expert_add_info_format(pinfo, length_item,
 578                     &ei_msdp_tlv_len_too_long,
 579                     "TLV length too long");
 580                 proto_tree_add_item(tree, hf_msdp_trailing_junk, tvb, *offset, tlv_len, ENC_NA);
 581                 *offset += tlv_len;
 582         }
 583
 584         return;
 585 }
 586
 587 void
 588 proto_register_msdp(void)
 589 {
 590         static hf_register_info hf[] = {
 591                 { &hf_msdp_type,
 592                         { "Type",           "msdp.type",
 593                         FT_UINT8, BASE_DEC, VALS(msdp_types), 0,
 594                         "MSDP TLV type", HFILL }
 595                 },
 596                 { &hf_msdp_length,
 597                         { "Length",           "msdp.length",
 598                         FT_UINT16, BASE_DEC, NULL, 0,
 599                         "MSDP TLV Length", HFILL }
 600                 },
 601                 { &hf_msdp_sa_entry_count,
 602                         { "Entry Count",           "msdp.sa.entry_count",
 603                         FT_UINT8, BASE_DEC, NULL, 0,
 604                         "MSDP SA Entry Count", HFILL }
 605                 },
 606                 { &hf_msdp_sa_rp_addr,
 607                         { "RP Address",           "msdp.sa.rp_addr",
 608                         FT_IPv4, BASE_NONE, NULL, 0,
 609                         "Active source's RP address", HFILL }
 610                 },
 611                 { &hf_msdp_sa_reserved,
 612                         { "Reserved",           "msdp.sa.reserved",
 613                         FT_UINT24, BASE_HEX, NULL, 0,
 614                         "Transmitted as zeros and ignored by a receiver", HFILL }
 615                 },
 616                 { &hf_msdp_sa_sprefix_len,
 617                         { "Sprefix len",           "msdp.sa.sprefix_len",
 618                         FT_UINT8, BASE_DEC, NULL, 0,
 619                         "The route prefix length associated with source address", HFILL }
 620                 },
 621                 { &hf_msdp_sa_group_addr,
 622                         { "Group Address",           "msdp.sa.group_addr",
 623                         FT_IPv4, BASE_NONE, NULL, 0,
 624                         "The group address the active source has sent data to", HFILL }
 625                 },
 626                 { &hf_msdp_sa_src_addr,
 627                         { "Source Address",           "msdp.sa.src_addr",
 628                         FT_IPv4, BASE_NONE, NULL, 0,
 629                         "The IP address of the active source", HFILL }
 630                 },
 631                 { &hf_msdp_sa_req_res,
 632                         { "Reserved",           "msdp.sa_req.res",
 633                         FT_UINT8, BASE_HEX, NULL, 0,
 634                         "Transmitted as zeros and ignored by a receiver", HFILL }
 635                 },
 636                 { &hf_msdp_sa_req_group,
 637                         { "Group Address",           "msdp.sa_req.group_addr",
 638                         FT_IPv4, BASE_NONE, NULL, 0,
 639                         "The group address the MSDP peer is requesting", HFILL }
 640                 },
 641                 { &hf_msdp_not_o,
 642                         { "Open-bit",           "msdp.not.o",
 643                         FT_UINT8, BASE_HEX, NULL, 0x80,
 644                         "If clear, the connection will be closed", HFILL }
 645                 },
 646                 { &hf_msdp_not_error,
 647                         { "Error Code",           "msdp.not.error",
 648                         FT_UINT8, BASE_DEC, VALS(error_vals), 0x7F,
 649                         "Indicates the type of Notification", HFILL }
 650                 },
 651                 { &hf_msdp_not_error_sub,
 652                         { "Error subcode",           "msdp.not.error_sub",
 653                         FT_UINT8, BASE_DEC, NULL, 0,
 654                         NULL, HFILL }
 655                 },
 656                 { &hf_msdp_not_group_address,
 657                         { "Group address",           "msdp.not.group_address",
 658                         FT_IPv4, BASE_NONE, NULL, 0,
 659                         "Group address in Notification messages", HFILL }
 660                 },
 661                 { &hf_msdp_not_rp_address,
 662                         { "RP address",           "msdp.not.rp_address",
 663                         FT_IPv4, BASE_NONE, NULL, 0,
 664                         "RP address in Notification messages", HFILL }
 665                 },
 666                 { &hf_msdp_not_source_address,
 667                         { "Source address",           "msdp.not.source_address",
 668                         FT_IPv4, BASE_NONE, NULL, 0,
 669                         "Source address in Notification messages", HFILL }
 670                 },
 671                 { &hf_msdp_not_res,
 672                         { "Reserved",           "msdp.not.res",
 673                         FT_UINT24, BASE_HEX, NULL, 0,
 674                         "Reserved field in Notification messages", HFILL }
 675                 },
 676                 { &hf_msdp_not_entry_count,
 677                         { "Entry Count",           "msdp.not.entry_count",
 678                         FT_UINT24, BASE_HEX, NULL, 0,
 679                         "Entry Count in Notification messages", HFILL }
 680                 },
 681                 { &hf_msdp_not_sprefix_len,
 682                         { "Sprefix len",           "msdp.not.sprefix_len",
 683                         FT_UINT8, BASE_DEC, NULL, 0,
 684                         "Source prefix length in Notification messages", HFILL }
 685                 },
 686                 { &hf_msdp_tlv_contents,
 687                         { "TLV contents",           "msdp.tlv_contents",
 688                         FT_BYTES, BASE_NONE, NULL, 0,
 689                         NULL, HFILL }
 690                 },
 691                 { &hf_msdp_trailing_junk,
 692                         { "Trailing junk",           "msdp.trailing_junk",
 693                         FT_BYTES, BASE_NONE, NULL, 0,
 694                         NULL, HFILL }
 695                 },
 696                 { &hf_msdp_unknown_data,
 697                         { "Unknown data",           "msdp.unknown_data",
 698                         FT_BYTES, BASE_NONE, NULL, 0,
 699                         NULL, HFILL }
 700                 },
 701         };
 702
 703         static gint *ett[] = {
 704                 &ett_msdp,
 705                 &ett_msdp_sa_entry,
 706                 &ett_msdp_sa_enc_data,
 707                 &ett_msdp_not_data,
 708         };
 709
 710         static ei_register_info ei[] = {
 711                 { &ei_msdp_tlv_len_too_long,
 712                     { "msdp.tlv_len.too_long", PI_PROTOCOL, PI_WARN,
 713                       "TLV length too long", EXPFILL }
 714                 },
 715                 { &ei_msdp_tlv_len_too_short,
 716                     { "msdp.tlv_len.too_short", PI_MALFORMED, PI_ERROR,
 717                       "TLV length too short", EXPFILL }
 718                 },
 719         };
 720
 721         expert_module_t *expert_msdp;
 722
 723         proto_msdp = proto_register_protocol("Multicast Source Discovery Protocol",
 724             "MSDP", "msdp");
 725
 726         proto_register_field_array(proto_msdp, hf, array_length(hf));
 727         proto_register_subtree_array(ett, array_length(ett));
 728         expert_msdp = expert_register_protocol(proto_msdp);
 729         expert_register_field_array(expert_msdp, ei, array_length(ei));
 730 }
 731
 732 void
 733 proto_reg_handoff_msdp(void)
 734 {
 735         dissector_handle_t msdp_handle;
 736
 737         msdp_handle = create_dissector_handle(dissect_msdp, proto_msdp);
 738         dissector_add_uint_with_preference("tcp.port", MSDP_PORT, msdp_handle);
 739
 740         ip_handle = find_dissector_add_dependency("ip", proto_msdp);
 741 }
 742
 743 /*
 744  * Editor modelines
 745  *
 746  * Local Variables:
 747  * c-basic-offset: 8
 748  * tab-width: 8
 749  * indent-tabs-mode: nil
 750  * End:
 751  *
 752  * ex: set shiftwidth=8 tabstop=8 expandtab:
 753  * :indentSize=8:tabSize=8:noTabs=true:
 754  */