packet-gvrp.c

   1 /* packet-gvrp.c
   2  * Routines for GVRP (GARP VLAN Registration Protocol) dissection
   3  * Copyright 2000, Kevin Shi <techishi@ms22.hinet.net>
   4  *
   5  * $Id: packet-gvrp.c,v 1.6 2001/06/18 02:17:46 guy Exp $
   6  *
   7  * Ethereal - Network traffic analyzer
   8  * By Gerald Combs <gerald@ethereal.com>
   9  * Copyright 1998 Gerald Combs
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public License
  13  * as published by the Free Software Foundation; either version 2
  14  * of the License, or (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  24  */
  25
  26 #ifdef HAVE_CONFIG_H
  27 # include "config.h"
  28 #endif
  29
  30 #include <stdio.h>
  31 #include <stdlib.h>
  32 #include <string.h>
  33
  34 #ifdef HAVE_SYS_TYPES_H
  35 # include <sys/types.h>
  36 #endif
  37
  38 #ifdef HAVE_NETINET_IN_H
  39 # include <netinet/in.h>
  40 #endif
  41
  42 #include <glib.h>
  43
  44 #ifdef NEED_SNPRINTF_H
  45 # include "snprintf.h"
  46 #endif
  47
  48 #include "packet.h"
  49 #include "llcsaps.h"
  50
  51 /* Initialize the protocol and registered fields */
  52 static int proto_gvrp = -1;
  53 static int hf_gvrp_proto_id = -1;
  54 static int hf_gvrp_attribute_type = -1;
  55 static int hf_gvrp_attribute_length = -1;
  56 static int hf_gvrp_attribute_event = -1;
  57 static int hf_gvrp_attribute_value = -1;
  58 /*static int hf_gvrp_end_of_mark = -1;*/
  59
  60 /* Initialize the subtree pointers */
  61 static gint ett_gvrp = -1;
  62 /*static gint ett_gvrp_message = -1;
  63 static gint ett_gvrp_attribute_list = -1;
  64 static gint ett_gvrp_attribute = -1;*/
  65
  66 /* Constant definitions */
  67 #define GARP_DEFAULT_PROTOCOL_ID        0x0001
  68 #define GARP_END_OF_MARK                0x00
  69
  70 #define GVRP_ATTRIBUTE_TYPE             0x01
  71
  72 static const value_string attribute_type_vals[] = {
  73         { GVRP_ATTRIBUTE_TYPE, "VID" },
  74         { 0,                   NULL }
  75 };
  76
  77 /* The length of GVRP LeaveAll attribute should be 2 octets (one for length
  78  * and the other for event) */
  79 #define GVRP_LENGTH_LEAVEALL            (sizeof(guint8)+sizeof(guint8))
  80
  81 /* The length of GVRP attribute other than LeaveAll should be 4 octets (one
  82  * for length, one for event, and the last two for VID value).
  83  */
  84 #define GVRP_LENGTH_NON_LEAVEALL        (sizeof(guint8)+sizeof(guint8)+sizeof(guint16))
  85
  86 /* Packet offset definitions */
  87 #define GARP_PROTOCOL_ID                0
  88
  89 /* Event definitions */
  90 #define GVRP_EVENT_LEAVEALL             0
  91 #define GVRP_EVENT_JOINEMPTY            1
  92 #define GVRP_EVENT_JOININ               2
  93 #define GVRP_EVENT_LEAVEEMPTY           3
  94 #define GVRP_EVENT_LEAVEIN              4
  95 #define GVRP_EVENT_EMPTY                5
  96
  97 static const value_string event_vals[] = {
  98         { GVRP_EVENT_LEAVEALL,   "Leave All" },
  99         { GVRP_EVENT_JOINEMPTY,  "Join Empty" },
 100         { GVRP_EVENT_JOININ,     "Join In" },
 101         { GVRP_EVENT_LEAVEEMPTY, "Leave Empty" },
 102         { GVRP_EVENT_LEAVEIN,    "Leave In" },
 103         { GVRP_EVENT_EMPTY,      "Empty" },
 104         { 0,                     NULL }
 105 };
 106
 107 /* Code to actually dissect the packets */
 108 static void
 109 dissect_gvrp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 110 {
 111     proto_item   *ti;
 112     proto_tree   *gvrp_tree;
 113     guint16       protocol_id;
 114     guint8        octet;
 115     int           msg_index, attr_index, offset = 0, length = tvb_reported_length(tvb);
 116
 117     if (check_col(pinfo->fd, COL_PROTOCOL))
 118         col_set_str(pinfo->fd, COL_PROTOCOL, "GVRP");
 119
 120     if (check_col(pinfo->fd, COL_INFO))
 121         col_set_str(pinfo->fd, COL_INFO, "GVRP");
 122
 123     if (tree)
 124     {
 125         ti = proto_tree_add_item(tree, proto_gvrp, tvb, 0, length, FALSE);
 126
 127         gvrp_tree = proto_item_add_subtree(ti, ett_gvrp);
 128
 129         /* Read in GARP protocol ID */
 130         protocol_id = tvb_get_ntohs(tvb, GARP_PROTOCOL_ID);
 131
 132         proto_tree_add_uint_format(gvrp_tree, hf_gvrp_proto_id, tvb,
 133                                    GARP_PROTOCOL_ID, sizeof(guint16),
 134                                    protocol_id,
 135                                    "Protocol Identifier: 0x%04x (%s)",
 136                                    protocol_id,
 137                                    protocol_id == GARP_DEFAULT_PROTOCOL_ID ?
 138                                      "GARP VLAN Registration Protocol" :
 139                                      "Unknown Protocol");
 140
 141         /* Currently only one protocol ID is supported */
 142         if (protocol_id != GARP_DEFAULT_PROTOCOL_ID)
 143         {
 144             proto_tree_add_text(gvrp_tree, tvb, GARP_PROTOCOL_ID, sizeof(guint16),
 145  "   (Warning: this version of Ethereal only knows about protocol id = 1)");
 146             dissect_data(tvb, GARP_PROTOCOL_ID + sizeof(guint16), 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             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(gvrp_tree, tvb, offset, sizeof(guint8),
 171                                         "End of mark");
 172                     break;
 173                 }
 174                 else
 175                 {
 176                     dissect_data(tvb, offset, pinfo, tree);
 177                     return;
 178                 }
 179             }
 180
 181             offset += sizeof(guint8);
 182             length -= sizeof(guint8);
 183
 184             msg_item = proto_tree_add_text(gvrp_tree, tvb, msg_start, 0,
 185                                            "Message %d", msg_index + 1);
 186
 187             proto_tree_add_uint(gvrp_tree, hf_gvrp_attribute_type, tvb,
 188                                 msg_start, sizeof(guint8), octet);
 189
 190             /* GVRP only supports one attribute type. */
 191             if (octet != GVRP_ATTRIBUTE_TYPE)
 192             {
 193                 dissect_data(tvb, offset, pinfo, tree);
 194                 return;
 195             }
 196
 197             attr_index = 0;
 198
 199             while (length)
 200             {
 201                 int          attr_start = offset;
 202                 proto_item   *attr_item;
 203
 204                 /* Read in attribute length. */
 205                 octet = tvb_get_guint8(tvb, offset);
 206
 207                 /* Check for end of mark */
 208                 if (octet == GARP_END_OF_MARK)
 209                 {
 210                     /* If at least one message has been already read,
 211                      * check for another end of mark.
 212                      */
 213                     if (attr_index)
 214                     {
 215                         proto_tree_add_text(gvrp_tree, tvb, offset,
 216                                             sizeof(guint8), "  End of mark");
 217
 218                         offset += sizeof(guint8);
 219                         length -= sizeof(guint8);
 220
 221                         proto_item_set_len(msg_item, offset - msg_start);
 222                         break;
 223                     }
 224                     else
 225                     {
 226                         dissect_data(tvb, offset, pinfo, tree);
 227                         return;
 228                     }
 229                 }
 230                 else
 231                 {
 232                     guint8   event;
 233
 234                     offset += sizeof(guint8);
 235                     length -= sizeof(guint8);
 236
 237                     attr_item = proto_tree_add_text(gvrp_tree, tvb,
 238                          attr_start, 0, "  Attribute %d", attr_index + 1);
 239
 240                     proto_tree_add_uint(gvrp_tree, hf_gvrp_attribute_length,
 241                          tvb, attr_start, sizeof(guint8), octet);
 242
 243                     /* Read in attribute event */
 244                     event = tvb_get_guint8(tvb, offset);
 245
 246                     proto_tree_add_uint(gvrp_tree, hf_gvrp_attribute_event,
 247                          tvb, offset, sizeof(guint8), event);
 248
 249                     offset += sizeof(guint8);
 250                     length -= sizeof(guint8);
 251
 252                     switch (event) {
 253
 254                     case GVRP_EVENT_LEAVEALL:
 255                         if (octet != GVRP_LENGTH_LEAVEALL)
 256                         {
 257                             dissect_data(tvb, offset, pinfo, tree);
 258                             return;
 259                         }
 260                         break;
 261
 262                      case GVRP_EVENT_JOINEMPTY:
 263                      case GVRP_EVENT_JOININ:
 264                      case GVRP_EVENT_LEAVEEMPTY:
 265                      case GVRP_EVENT_LEAVEIN:
 266                      case GVRP_EVENT_EMPTY:
 267                         if (octet != GVRP_LENGTH_NON_LEAVEALL)
 268                         {
 269                             dissect_data(tvb, offset, pinfo, tree);
 270                             return;
 271                         }
 272
 273                         /* Show attribute value */
 274                         proto_tree_add_item(gvrp_tree, hf_gvrp_attribute_value,
 275                             tvb, offset, sizeof(guint16), FALSE);
 276
 277                         offset += sizeof(guint16);
 278                         length -= sizeof(guint16);
 279                         break;
 280
 281                      default:
 282                         dissect_data(tvb, offset, pinfo, tree);
 283                         return;
 284                     }
 285                 }
 286
 287                 proto_item_set_len(attr_item, offset - attr_start);
 288
 289                 attr_index++;
 290             }
 291
 292             msg_index++;
 293         }
 294     }
 295 }
 296
 297
 298 /* Register the protocol with Ethereal */
 299 void
 300 proto_register_gvrp(void)
 301 {
 302     static hf_register_info hf[] = {
 303         { &hf_gvrp_proto_id,
 304             { "Protocol ID", "garp.protocol_id",
 305             FT_UINT16,      BASE_HEX,      NULL,  0x0,
 306             "", HFILL }
 307         },
 308         { &hf_gvrp_attribute_type,
 309             { "Type",        "garp.attribute_type",
 310             FT_UINT8,        BASE_HEX,      VALS(attribute_type_vals),  0x0,
 311             "", HFILL }
 312         },
 313         { &hf_gvrp_attribute_length,
 314             { "Length",      "garp.attribute_length",
 315             FT_UINT8,        BASE_DEC,      NULL,  0x0,
 316             "", HFILL }
 317         },
 318         { &hf_gvrp_attribute_event,
 319             { "Event",       "garp.attribute_event",
 320             FT_UINT8,        BASE_DEC,      VALS(event_vals),  0x0,
 321             "", HFILL }
 322         },
 323         { &hf_gvrp_attribute_value,
 324             { "Value",       "garp.attribute_value",
 325             FT_UINT16,       BASE_DEC,      NULL,  0x0,
 326             "", HFILL }
 327         }
 328     };
 329
 330     static gint *ett[] = {
 331         &ett_gvrp
 332     };
 333
 334     /* Register the protocol name and description for GVRP */
 335     proto_gvrp = proto_register_protocol("GARP VLAN Registration Protocol",
 336                                          "GVRP", "gvrp");
 337
 338     /* Required function calls to register the header fields and subtrees
 339      * used by GVRP */
 340     proto_register_field_array(proto_gvrp, hf, array_length(hf));
 341     proto_register_subtree_array(ett, array_length(ett));
 342
 343     register_dissector("gvrp", dissect_gvrp, proto_gvrp);
 344 }