epan/dissectors/packet-gmrp.c

   1 /* packet-gmrp.c
   2  * Routines for GMRP (GARP Multicast Registration Protocol) dissection
   3  * Copyright 2001, Markus Seehofer <mseehofe@nt.hirschmann.de>
   4  *
   5  * Based on the code from packet-gvrp.c (GVRP) from
   6  * Kevin Shi <techishi@ms22.hinet.net> Copyright 2000
   7  *
   8  * $Id$
   9  *
  10  * Wireshark - Network traffic analyzer
  11  * By Gerald Combs <gerald@wireshark.org>
  12  * Copyright 1998 Gerald Combs
  13  *
  14  * This program is free software; you can redistribute it and/or
  15  * modify it under the terms of the GNU General Public License
  16  * as published by the Free Software Foundation; either version 2
  17  * of the License, or (at your option) any later version.
  18  *
  19  * This program is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with this program; if not, write to the Free Software
  26  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  27  */
  28
  29 #include "config.h"
  30
  31 #include <glib.h>
  32
  33 #include <epan/packet.h>
  34 #include <epan/llcsaps.h>
  35
  36 /* Initialize the protocol and registered fields */
  37 static int proto_gmrp = -1;
  38 static int hf_gmrp_proto_id = -1;
  39 static int hf_gmrp_attribute_type = -1;
  40 static int hf_gmrp_attribute_length = -1;
  41 static int hf_gmrp_attribute_event = -1;
  42 static int hf_gmrp_attribute_value_group_membership = -1;
  43 static int hf_gmrp_attribute_value_service_requirement = -1;
  44 /*static int hf_gmrp_end_of_mark = -1;*/
  45
  46 /* Initialize the subtree pointers */
  47 static gint ett_gmrp = -1;
  48 /*static gint ett_gmrp_message = -1;
  49 static gint ett_gmrp_attribute_list = -1;
  50 static gint ett_gmrp_attribute = -1;*/
  51
  52 static dissector_handle_t data_handle;
  53
  54 /* Constant definitions */
  55 #define GARP_DEFAULT_PROTOCOL_ID    0x0001
  56 #define GARP_END_OF_MARK            0x00
  57
  58 #define GMRP_ATTRIBUTE_TYPE_GROUP_MEMBERSHIP    0x01
  59 #define GMRP_ATTRIBUTE_TYPE_SERVICE_REQUIREMENT 0x02
  60
  61 #define GMRP_SERVICE_REQUIREMENT_FORWARD_ALL                0x00
  62 #define GMRP_SERVICE_REQUIREMENT_FORWARD_ALL_UNREGISTERED   0x01
  63
  64 static const value_string attribute_type_vals[] = {
  65     { GMRP_ATTRIBUTE_TYPE_GROUP_MEMBERSHIP    ,"Group Membership" },
  66     { GMRP_ATTRIBUTE_TYPE_SERVICE_REQUIREMENT ,"Service Requirement" },
  67     { 0,                   NULL }
  68 };
  69
  70 /* The length of GMRP LeaveAll attribute should be 2 octets (one for length
  71  * and the other for event) */
  72 #define GMRP_LENGTH_LEAVEALL        (sizeof(guint8)+sizeof(guint8))
  73
  74 /* The length of GMRP attribute other than LeaveAll should be:
  75 *
  76 *  8 bytes for Group Membership (1 for length, 1 for event and 6 for mac address to register)
  77 *  or
  78 *  3 bytes for Service Requirement (1 for length, 1 for event, 1 for attribute value)
  79 *
  80  */
  81 #define GMRP_GROUP_MEMBERSHIP_NON_LEAVEALL      (sizeof(guint8)+sizeof(guint8)+(6*sizeof(guint8)))
  82 #define GMRP_SERVICE_REQUIREMENT_NON_LEAVEALL   (sizeof(guint8)+sizeof(guint8)+sizeof(guint8))
  83
  84 /* Packet offset definitions */
  85 #define GARP_PROTOCOL_ID        0
  86
  87 /* Event definitions */
  88 #define GMRP_EVENT_LEAVEALL     0
  89 #define GMRP_EVENT_JOINEMPTY    1
  90 #define GMRP_EVENT_JOININ       2
  91 #define GMRP_EVENT_LEAVEEMPTY   3
  92 #define GMRP_EVENT_LEAVEIN      4
  93 #define GMRP_EVENT_EMPTY        5
  94
  95 static const value_string event_vals[] = {
  96     { GMRP_EVENT_LEAVEALL,   "Leave All" },
  97     { GMRP_EVENT_JOINEMPTY,  "Join Empty" },
  98     { GMRP_EVENT_JOININ,     "Join In" },
  99     { GMRP_EVENT_LEAVEEMPTY, "Leave Empty" },
 100     { GMRP_EVENT_LEAVEIN,    "Leave In" },
 101     { GMRP_EVENT_EMPTY,      "Empty" },
 102     { 0,                     NULL }
 103 };
 104
 105
 106 /* Code to actually dissect the packets */
 107 static void
 108 dissect_gmrp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 109 {
 110     proto_item   *ti;
 111     proto_tree   *gmrp_tree;
 112     guint16       protocol_id;
 113     guint8        octet;
 114     guint8        attribute_type;
 115     int           msg_index, attr_index, offset = 0, length = tvb_reported_length(tvb);
 116
 117     col_set_str(pinfo->cinfo, COL_PROTOCOL, "GMRP");
 118
 119     col_set_str(pinfo->cinfo, COL_INFO, "GMRP");
 120
 121     if (tree)
 122     {
 123         ti = proto_tree_add_item(tree, proto_gmrp, tvb, 0, -1, ENC_NA);
 124
 125         gmrp_tree = proto_item_add_subtree(ti, ett_gmrp);
 126
 127         /* Read in GARP protocol ID */
 128         protocol_id = tvb_get_ntohs(tvb, GARP_PROTOCOL_ID);
 129
 130         proto_tree_add_uint_format(gmrp_tree, hf_gmrp_proto_id, tvb,
 131                                    GARP_PROTOCOL_ID, sizeof(guint16),
 132                                    protocol_id,
 133                                    "Protocol Identifier: 0x%04x (%s)",
 134                                    protocol_id,
 135                                    protocol_id == GARP_DEFAULT_PROTOCOL_ID ?
 136                                      "GARP Multicast Registration Protocol" :
 137                                      "Unknown Protocol");
 138
 139         /* Currently only one protocol ID is supported */
 140         if (protocol_id != GARP_DEFAULT_PROTOCOL_ID)
 141         {
 142             proto_tree_add_text(gmrp_tree, tvb, GARP_PROTOCOL_ID, sizeof(guint16),
 143                 "   (Warning: this version of Wireshark only knows about protocol id = 1)");
 144             call_dissector(data_handle,
 145                 tvb_new_subset_remaining(tvb, GARP_PROTOCOL_ID + sizeof(guint16)),
 146                 pinfo, tree);
 147             return;
 148         }
 149
 150         offset += sizeof(guint16);
 151         length -= sizeof(guint16);
 152
 153         msg_index = 0;
 154
 155         /* Begin to parse GARP messages */
 156         while (length)
 157         {
 158             proto_item   *msg_item;
 159             int           msg_start = offset;
 160
 161             /* Read in attribute type. */
 162             attribute_type = octet = tvb_get_guint8(tvb, offset);
 163
 164             /* Check for end of mark */
 165             if (octet == GARP_END_OF_MARK)
 166             {
 167                 /* End of GARP PDU */
 168                 if (msg_index)
 169                 {
 170                     proto_tree_add_text(gmrp_tree, tvb, offset, sizeof(guint8),
 171                                         "End of pdu");
 172                     break;
 173                 }
 174                 else
 175                 {
 176                     call_dissector(data_handle,
 177                                    tvb_new_subset_remaining(tvb, offset),
 178                                    pinfo, tree);
 179                     return;
 180                 }
 181             }
 182
 183             offset += sizeof(guint8);
 184             length -= sizeof(guint8);
 185
 186             msg_item = proto_tree_add_text(gmrp_tree, tvb, msg_start, -1,
 187                                            "Message %d", msg_index + 1);
 188
 189             proto_tree_add_uint(gmrp_tree, hf_gmrp_attribute_type, tvb,
 190                                 msg_start, sizeof(guint8), octet);
 191
 192             /* GMRP supports Group Membership and Service Requirement as attribute types */
 193             if ( (octet != GMRP_ATTRIBUTE_TYPE_GROUP_MEMBERSHIP) && (octet != GMRP_ATTRIBUTE_TYPE_SERVICE_REQUIREMENT) )
 194             {
 195                 call_dissector(data_handle,
 196                                tvb_new_subset_remaining(tvb, offset), pinfo,
 197                                tree);
 198                 return;
 199             }
 200
 201             attr_index = 0;
 202
 203             while (length)
 204             {
 205                 int          attr_start = offset;
 206                 proto_item   *attr_item;
 207
 208                 /* Read in attribute length. */
 209                 octet = tvb_get_guint8(tvb, offset);
 210
 211                 /* Check for end of mark */
 212                 if (octet == GARP_END_OF_MARK)
 213                 {
 214                     /* If at least one message has been already read,
 215                      * check for another end of mark.
 216                      */
 217                     if (attr_index)
 218                     {
 219                         proto_tree_add_text(gmrp_tree, tvb, offset,
 220                                             sizeof(guint8), "  End of mark");
 221
 222                         offset += sizeof(guint8);
 223                         length -= sizeof(guint8);
 224
 225                         proto_item_set_len(msg_item, offset - msg_start);
 226                         break;
 227                     }
 228                     else
 229                     {
 230                         call_dissector(data_handle,
 231                                        tvb_new_subset_remaining(tvb, offset),
 232                                        pinfo, tree);
 233                         return;
 234                     }
 235                 }
 236                 else
 237                 {
 238                     guint8   event;
 239
 240                     offset += sizeof(guint8);
 241                     length -= sizeof(guint8);
 242
 243                     attr_item = proto_tree_add_text(gmrp_tree, tvb,
 244                                                     attr_start, -1, "  Attribute %d", attr_index + 1);
 245
 246                     proto_tree_add_uint(gmrp_tree, hf_gmrp_attribute_length,
 247                                         tvb, attr_start, sizeof(guint8), octet);
 248
 249                     /* Read in attribute event */
 250                     event = tvb_get_guint8(tvb, offset);
 251
 252                     proto_tree_add_uint(gmrp_tree, hf_gmrp_attribute_event,
 253                                         tvb, offset, sizeof(guint8), event);
 254
 255                     offset += sizeof(guint8);
 256                     length -= sizeof(guint8);
 257
 258                     switch (event) {
 259
 260                     case GMRP_EVENT_LEAVEALL:
 261                         if (octet != GMRP_LENGTH_LEAVEALL)
 262                         {
 263                             call_dissector(data_handle,
 264                                            tvb_new_subset_remaining(tvb, offset),
 265                                            pinfo, tree);
 266                             return;
 267                         }
 268                         break;
 269
 270                     case GMRP_EVENT_JOINEMPTY:
 271                     case GMRP_EVENT_JOININ:
 272                     case GMRP_EVENT_LEAVEEMPTY:
 273                     case GMRP_EVENT_LEAVEIN:
 274                     case GMRP_EVENT_EMPTY:
 275                         if ( (octet != GMRP_GROUP_MEMBERSHIP_NON_LEAVEALL) &&
 276                              (octet != GMRP_SERVICE_REQUIREMENT_NON_LEAVEALL) )
 277                         {
 278                             call_dissector(data_handle,
 279                                            tvb_new_subset_remaining(tvb, offset),
 280                                            pinfo, tree);
 281                             return;
 282                         }
 283
 284                         /* Show attribute value */
 285
 286                         if ( GMRP_ATTRIBUTE_TYPE_GROUP_MEMBERSHIP == attribute_type )
 287                         {
 288                             /* Group Membership */
 289                             proto_tree_add_item(gmrp_tree, hf_gmrp_attribute_value_group_membership,
 290                                                 tvb, offset, (6*sizeof(guint8)), ENC_NA);
 291
 292                             offset += 6*sizeof(guint8);
 293                             length -= 6*sizeof(guint8);
 294                         }
 295                         else
 296                             if ( GMRP_ATTRIBUTE_TYPE_SERVICE_REQUIREMENT == attribute_type )
 297                             {
 298                                 /* Service Requirement */
 299                                 proto_tree_add_item(gmrp_tree, hf_gmrp_attribute_value_service_requirement,
 300                                                     tvb, offset, sizeof(guint8), ENC_BIG_ENDIAN);
 301
 302                                 offset += sizeof(guint8);
 303                                 length -= sizeof(guint8);
 304                             }
 305                             else
 306                             {
 307                                 call_dissector(data_handle,
 308                                                tvb_new_subset_remaining(tvb, offset),
 309                                                pinfo, tree);
 310                                 return;
 311                             }
 312
 313                         break;
 314
 315                     default:
 316                         call_dissector(data_handle,
 317                                        tvb_new_subset_remaining(tvb, offset),
 318                                        pinfo, tree);
 319                         return;
 320                     }
 321                 }
 322
 323                 proto_item_set_len(attr_item, offset - attr_start);
 324
 325                 attr_index++;
 326             }
 327
 328             msg_index++;
 329         }
 330     }
 331 }
 332
 333
 334
 335 /* Register the protocol with Wireshark */
 336 void
 337 proto_register_gmrp(void)
 338 {
 339     static hf_register_info hf[] = {
 340         { &hf_gmrp_proto_id,
 341           { "Protocol ID", "gmrp.protocol_id",
 342             FT_UINT16,      BASE_HEX,      NULL,  0x0,
 343             NULL , HFILL }
 344         },
 345         { &hf_gmrp_attribute_type,
 346           { "Type",        "gmrp.attribute_type",
 347             FT_UINT8,        BASE_HEX,      VALS(attribute_type_vals),  0x0,
 348             NULL , HFILL }
 349         },
 350         { &hf_gmrp_attribute_length,
 351           { "Length",      "gmrp.attribute_length",
 352             FT_UINT8,        BASE_DEC,      NULL,  0x0,
 353             NULL , HFILL }
 354         },
 355         { &hf_gmrp_attribute_event,
 356           { "Event",       "gmrp.attribute_event",
 357             FT_UINT8,        BASE_DEC,      VALS(event_vals),  0x0,
 358             NULL , HFILL }
 359         },
 360         { &hf_gmrp_attribute_value_group_membership,
 361           { "Value",       "gmrp.attribute_value_group_membership",
 362             FT_ETHER,        BASE_NONE,      NULL,  0x0,
 363             NULL , HFILL }
 364         },
 365         { &hf_gmrp_attribute_value_service_requirement,
 366           { "Value",       "gmrp.attribute_value_service_requirement",
 367             FT_UINT8,        BASE_HEX,      NULL,  0x0,
 368             NULL , HFILL }
 369         }
 370
 371     };
 372
 373     static gint *ett[] = {
 374         &ett_gmrp
 375     };
 376
 377     /* Register the protocol name and description for GMRP */
 378     proto_gmrp = proto_register_protocol("GARP Multicast Registration Protocol", "GMRP", "gmrp");
 379
 380     /* Required function calls to register the header fields and subtrees
 381      * used by GMRP */
 382     proto_register_field_array(proto_gmrp, hf, array_length(hf));
 383     proto_register_subtree_array(ett, array_length(ett));
 384
 385     register_dissector("gmrp", dissect_gmrp, proto_gmrp);
 386
 387 }
 388
 389 void
 390 proto_reg_handoff_gmrp(void){
 391     data_handle = find_dissector("data");
 392 }