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 1.10 2002/01/21 07:36:34 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 <epan/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 static dissector_handle_t data_handle;
  67
  68 /* Constant definitions */
  69 #define GARP_DEFAULT_PROTOCOL_ID        0x0001
  70 #define GARP_END_OF_MARK                0x00
  71
  72 #define GVRP_ATTRIBUTE_TYPE             0x01
  73
  74 static const value_string attribute_type_vals[] = {
  75         { GVRP_ATTRIBUTE_TYPE, "VID" },
  76         { 0,                   NULL }
  77 };
  78
  79 /* The length of GVRP LeaveAll attribute should be 2 octets (one for length
  80  * and the other for event) */
  81 #define GVRP_LENGTH_LEAVEALL            (sizeof(guint8)+sizeof(guint8))
  82
  83 /* The length of GVRP attribute other than LeaveAll should be 4 octets (one
  84  * for length, one for event, and the last two for VID value).
  85  */
  86 #define GVRP_LENGTH_NON_LEAVEALL        (sizeof(guint8)+sizeof(guint8)+sizeof(guint16))
  87
  88 /* Packet offset definitions */
  89 #define GARP_PROTOCOL_ID                0
  90
  91 /* Event definitions */
  92 #define GVRP_EVENT_LEAVEALL             0
  93 #define GVRP_EVENT_JOINEMPTY            1
  94 #define GVRP_EVENT_JOININ               2
  95 #define GVRP_EVENT_LEAVEEMPTY           3
  96 #define GVRP_EVENT_LEAVEIN              4
  97 #define GVRP_EVENT_EMPTY                5
  98
  99 static const value_string event_vals[] = {
 100         { GVRP_EVENT_LEAVEALL,   "Leave All" },
 101         { GVRP_EVENT_JOINEMPTY,  "Join Empty" },
 102         { GVRP_EVENT_JOININ,     "Join In" },
 103         { GVRP_EVENT_LEAVEEMPTY, "Leave Empty" },
 104         { GVRP_EVENT_LEAVEIN,    "Leave In" },
 105         { GVRP_EVENT_EMPTY,      "Empty" },
 106         { 0,                     NULL }
 107 };
 108
 109 /* Code to actually dissect the packets */
 110 static void
 111 dissect_gvrp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
 112 {
 113     proto_item   *ti;
 114     proto_tree   *gvrp_tree;
 115     guint16       protocol_id;
 116     guint8        octet;
 117     int           msg_index, attr_index, offset = 0, length = tvb_reported_length(tvb);
 118
 119     if (check_col(pinfo->cinfo, COL_PROTOCOL))
 120         col_set_str(pinfo->cinfo, COL_PROTOCOL, "GVRP");
 121
 122     if (check_col(pinfo->cinfo, COL_INFO))
 123         col_set_str(pinfo->cinfo, COL_INFO, "GVRP");
 124
 125     if (tree)
 126     {
 127         ti = proto_tree_add_item(tree, proto_gvrp, tvb, 0, length, FALSE);
 128
 129         gvrp_tree = proto_item_add_subtree(ti, ett_gvrp);
 130
 131         /* Read in GARP protocol ID */
 132         protocol_id = tvb_get_ntohs(tvb, GARP_PROTOCOL_ID);
 133
 134         proto_tree_add_uint_format(gvrp_tree, hf_gvrp_proto_id, tvb,
 135                                    GARP_PROTOCOL_ID, sizeof(guint16),
 136                                    protocol_id,
 137                                    "Protocol Identifier: 0x%04x (%s)",
 138                                    protocol_id,
 139                                    protocol_id == GARP_DEFAULT_PROTOCOL_ID ?
 140                                      "GARP VLAN Registration Protocol" :
 141                                      "Unknown Protocol");
 142
 143         /* Currently only one protocol ID is supported */
 144         if (protocol_id != GARP_DEFAULT_PROTOCOL_ID)
 145         {
 146             proto_tree_add_text(gvrp_tree, tvb, GARP_PROTOCOL_ID, sizeof(guint16),
 147  "   (Warning: this version of Ethereal only knows about protocol id = 1)");
 148             call_dissector(data_handle,tvb_new_subset(tvb, GARP_PROTOCOL_ID + sizeof(guint16), -1,tvb_reported_length_remaining(tvb,GARP_PROTOCOL_ID + sizeof(guint16))), pinfo, tree);
 149             return;
 150         }
 151
 152         offset += sizeof(guint16);
 153         length -= sizeof(guint16);
 154
 155         msg_index = 0;
 156
 157         /* Begin to parse GARP messages */
 158         while (length)
 159         {
 160             proto_item   *msg_item;
 161             int           msg_start = offset;
 162
 163             /* Read in attribute type. */
 164             octet = tvb_get_guint8(tvb, offset);
 165
 166             /* Check for end of mark */
 167             if (octet == GARP_END_OF_MARK)
 168             {
 169                 /* End of GARP PDU */
 170                 if (msg_index)
 171                 {
 172                     proto_tree_add_text(gvrp_tree, tvb, offset, sizeof(guint8),
 173                                         "End of mark");
 174                     break;
 175                 }
 176                 else
 177                 {
 178                     call_dissector(data_handle,tvb_new_subset(tvb, offset, -1,tvb_reported_length_remaining(tvb,offset)),pinfo, tree);
 179                     return;
 180                 }
 181             }
 182
 183             offset += sizeof(guint8);
 184             length -= sizeof(guint8);
 185
 186             msg_item = proto_tree_add_text(gvrp_tree, tvb, msg_start, -1,
 187                                            "Message %d", msg_index + 1);
 188
 189             proto_tree_add_uint(gvrp_tree, hf_gvrp_attribute_type, tvb,
 190                                 msg_start, sizeof(guint8), octet);
 191
 192             /* GVRP only supports one attribute type. */
 193             if (octet != GVRP_ATTRIBUTE_TYPE)
 194             {
 195                 call_dissector(data_handle,tvb_new_subset(tvb, offset,-1,tvb_reported_length_remaining(tvb,offset)), pinfo, tree);
 196                 return;
 197             }
 198
 199             attr_index = 0;
 200
 201             while (length)
 202             {
 203                 int          attr_start = offset;
 204                 proto_item   *attr_item;
 205
 206                 /* Read in attribute length. */
 207                 octet = tvb_get_guint8(tvb, offset);
 208
 209                 /* Check for end of mark */
 210                 if (octet == GARP_END_OF_MARK)
 211                 {
 212                     /* If at least one message has been already read,
 213                      * check for another end of mark.
 214                      */
 215                     if (attr_index)
 216                     {
 217                         proto_tree_add_text(gvrp_tree, tvb, offset,
 218                                             sizeof(guint8), "  End of mark");
 219
 220                         offset += sizeof(guint8);
 221                         length -= sizeof(guint8);
 222
 223                         proto_item_set_len(msg_item, offset - msg_start);
 224                         break;
 225                     }
 226                     else
 227                     {
 228                         call_dissector(data_handle,tvb_new_subset(tvb, offset,-1,tvb_reported_length_remaining(tvb,offset)), pinfo, tree);
 229                         return;
 230                     }
 231                 }
 232                 else
 233                 {
 234                     guint8   event;
 235
 236                     offset += sizeof(guint8);
 237                     length -= sizeof(guint8);
 238
 239                     attr_item = proto_tree_add_text(gvrp_tree, tvb,
 240                          attr_start, -1, "  Attribute %d", attr_index + 1);
 241
 242                     proto_tree_add_uint(gvrp_tree, hf_gvrp_attribute_length,
 243                          tvb, attr_start, sizeof(guint8), octet);
 244
 245                     /* Read in attribute event */
 246                     event = tvb_get_guint8(tvb, offset);
 247
 248                     proto_tree_add_uint(gvrp_tree, hf_gvrp_attribute_event,
 249                          tvb, offset, sizeof(guint8), event);
 250
 251                     offset += sizeof(guint8);
 252                     length -= sizeof(guint8);
 253
 254                     switch (event) {
 255
 256                     case GVRP_EVENT_LEAVEALL:
 257                         if (octet != GVRP_LENGTH_LEAVEALL)
 258                         {
 259                             call_dissector(data_handle,tvb_new_subset(tvb, offset, -1,tvb_reported_length_remaining(tvb,offset)),pinfo, tree);
 260                             return;
 261                         }
 262                         break;
 263
 264                      case GVRP_EVENT_JOINEMPTY:
 265                      case GVRP_EVENT_JOININ:
 266                      case GVRP_EVENT_LEAVEEMPTY:
 267                      case GVRP_EVENT_LEAVEIN:
 268                      case GVRP_EVENT_EMPTY:
 269                         if (octet != GVRP_LENGTH_NON_LEAVEALL)
 270                         {
 271                             call_dissector(data_handle,tvb_new_subset(tvb, offset, -1,tvb_reported_length_remaining(tvb,offset)),pinfo, tree);
 272                             return;
 273                         }
 274
 275                         /* Show attribute value */
 276                         proto_tree_add_item(gvrp_tree, hf_gvrp_attribute_value,
 277                             tvb, offset, sizeof(guint16), FALSE);
 278
 279                         offset += sizeof(guint16);
 280                         length -= sizeof(guint16);
 281                         break;
 282
 283                      default:
 284                         call_dissector(data_handle,tvb_new_subset(tvb, offset, -1,tvb_reported_length_remaining(tvb,offset)),pinfo, tree);
 285                         return;
 286                     }
 287                 }
 288
 289                 proto_item_set_len(attr_item, offset - attr_start);
 290
 291                 attr_index++;
 292             }
 293
 294             msg_index++;
 295         }
 296     }
 297 }
 298
 299
 300 /* Register the protocol with Ethereal */
 301 void
 302 proto_register_gvrp(void)
 303 {
 304     static hf_register_info hf[] = {
 305         { &hf_gvrp_proto_id,
 306             { "Protocol ID", "garp.protocol_id",
 307             FT_UINT16,      BASE_HEX,      NULL,  0x0,
 308             "", HFILL }
 309         },
 310         { &hf_gvrp_attribute_type,
 311             { "Type",        "garp.attribute_type",
 312             FT_UINT8,        BASE_HEX,      VALS(attribute_type_vals),  0x0,
 313             "", HFILL }
 314         },
 315         { &hf_gvrp_attribute_length,
 316             { "Length",      "garp.attribute_length",
 317             FT_UINT8,        BASE_DEC,      NULL,  0x0,
 318             "", HFILL }
 319         },
 320         { &hf_gvrp_attribute_event,
 321             { "Event",       "garp.attribute_event",
 322             FT_UINT8,        BASE_DEC,      VALS(event_vals),  0x0,
 323             "", HFILL }
 324         },
 325         { &hf_gvrp_attribute_value,
 326             { "Value",       "garp.attribute_value",
 327             FT_UINT16,       BASE_DEC,      NULL,  0x0,
 328             "", HFILL }
 329         }
 330     };
 331
 332     static gint *ett[] = {
 333         &ett_gvrp
 334     };
 335
 336     /* Register the protocol name and description for GVRP */
 337     proto_gvrp = proto_register_protocol("GARP VLAN Registration Protocol",
 338                                          "GVRP", "gvrp");
 339
 340     /* Required function calls to register the header fields and subtrees
 341      * used by GVRP */
 342     proto_register_field_array(proto_gvrp, hf, array_length(hf));
 343     proto_register_subtree_array(ett, array_length(ett));
 344
 345     register_dissector("gvrp", dissect_gvrp, proto_gvrp);
 346 }
 347
 348 void
 349 proto_reg_handoff_gvrp(void){
 350   data_handle = find_dissector("data");
 351 }