packet-isl.c

   1 /* packet-isl.c
   2  * Routines for Cisco ISL Ethernet header disassembly
   3  *
   4  * $Id: packet-isl.c,v 1.13 2000/06/15 03:48:41 gram Exp $
   5  *
   6  * Ethereal - Network traffic analyzer
   7  * By Gerald Combs <gerald@zing.org>
   8  * Copyright 1998 Gerald Combs
   9  *
  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 #ifdef HAVE_SYS_TYPES_H
  31 # include <sys/types.h>
  32 #endif
  33
  34 #ifdef HAVE_NETINET_IN_H
  35 # include <netinet/in.h>
  36 #endif
  37
  38 #include <glib.h>
  39 #include "packet.h"
  40 #include "packet-eth.h"
  41 #include "packet-tr.h"
  42 #include "etypes.h"
  43
  44 /*
  45  * See
  46  *
  47  *      http://www.cisco.com/warp/public/741/4.html
  48  *
  49  * and
  50  *
  51  *      http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/frames.htm
  52  *
  53  * for information on ISL.
  54  */
  55 static int proto_isl = -1;
  56 static int hf_isl_dst = -1;
  57 static int hf_isl_type = -1;
  58 static int hf_isl_user_eth = -1;
  59 static int hf_isl_user = -1;
  60 static int hf_isl_src = -1;
  61 static int hf_isl_addr = -1;
  62 static int hf_isl_len = -1;
  63 static int hf_isl_hsa = -1;
  64 static int hf_isl_vlan_id = -1;
  65 static int hf_isl_bpdu = -1;
  66 static int hf_isl_index = -1;
  67 static int hf_isl_crc = -1;
  68 static int hf_isl_src_vlan_id = -1;
  69 static int hf_isl_explorer = -1;
  70 static int hf_isl_dst_route_descriptor = -1;
  71 static int hf_isl_src_route_descriptor = -1;
  72 static int hf_isl_fcs_not_incl = -1;
  73 static int hf_isl_esize = -1;
  74
  75 static gint ett_isl = -1;
  76
  77 #define ISL_HEADER_SIZE 26
  78
  79 #define TYPE_ETHER      0x0
  80 #define TYPE_TR         0x1
  81 #define TYPE_FDDI       0x2
  82 #define TYPE_ATM        0x3
  83
  84 void
  85 capture_isl(const u_char *pd, int offset, packet_counts *ld)
  86 {
  87   guint8 type;
  88
  89   if (!BYTES_ARE_IN_FRAME(offset, ISL_HEADER_SIZE)) {
  90     ld->other++;
  91     return;
  92   }
  93
  94   type = (pd[offset+5] >> 4)&0x0F;
  95
  96   switch (type) {
  97
  98   case TYPE_ETHER:
  99     offset += 14+12;    /* skip the header */
 100     capture_eth(pd, offset, ld);
 101     break;
 102
 103   case TYPE_TR:
 104     offset += 14+17;    /* skip the header */
 105     capture_tr(pd, offset, ld);
 106     break;
 107
 108   default:
 109     ld->other++;
 110     break;
 111   }
 112 }
 113
 114 static const value_string type_vals[] = {
 115         {TYPE_ETHER, "Ethernet"},
 116         {TYPE_TR,    "Token-Ring"},
 117         {TYPE_FDDI,  "FDDI"},
 118         {TYPE_ATM,   "ATM"},
 119         {0,          NULL}
 120 };
 121
 122 static const value_string ether_user_vals[] = {
 123         {0x0, "Normal priority"},
 124         {0x1, "Priority 1"},
 125         {0x2, "Priority 2"},
 126         {0x3, "Highest priority"},
 127         {0,   NULL}
 128 };
 129
 130 static const true_false_string bpdu_tfs = {
 131         "Yes",
 132         "No"
 133 };
 134
 135 static const true_false_string explorer_tfs = {
 136         "Explorer frame",
 137         "Data frame"
 138 };
 139
 140 void
 141 dissect_isl(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
 142 {
 143   proto_tree *fh_tree = NULL;
 144   proto_item *ti;
 145   guint8 type;
 146   guint16 length;
 147   tvbuff_t *next_tvb;
 148
 149   if (!BYTES_ARE_IN_FRAME(offset, ISL_HEADER_SIZE)) {
 150     dissect_data(pd, offset, fd, tree);
 151     return;
 152   }
 153
 154   if (check_col(fd, COL_PROTOCOL))
 155     col_add_str(fd, COL_PROTOCOL, "ISL");
 156   if (check_col(fd, COL_INFO))
 157     col_add_fstr(fd, COL_INFO, "VLAN ID: 0x%04X", pntohs(&pd[offset+20]) >> 1);
 158
 159   type = (pd[offset+5] >> 4)&0x0F;
 160
 161   if (tree) {
 162     ti = proto_tree_add_protocol_format(tree, proto_isl, NullTVB, offset, ISL_HEADER_SIZE,
 163                 "ISL");
 164     fh_tree = proto_item_add_subtree(ti, ett_isl);
 165     proto_tree_add_ether(fh_tree, hf_isl_dst, NullTVB, offset+0, 6, &pd[offset+0]);
 166     proto_tree_add_ether_hidden(fh_tree, hf_isl_addr, NullTVB, offset+0, 6, &pd[offset+0]);
 167     proto_tree_add_uint(fh_tree, hf_isl_type, NullTVB, offset+5, 1, pd[offset+5]);
 168     switch (type) {
 169
 170     case TYPE_ETHER:
 171       proto_tree_add_uint(fh_tree, hf_isl_user_eth, NullTVB, offset+5, 1,
 172                         pd[offset+5]&0x03);
 173       break;
 174
 175     default:
 176       /* XXX - the spec appears to indicate that the "User" field is
 177          used for TYPE_TR to distinguish between types of packets. */
 178       proto_tree_add_uint(fh_tree, hf_isl_user, NullTVB, offset+5, 1, pd[offset+5]);
 179       break;
 180     }
 181     proto_tree_add_ether(fh_tree, hf_isl_src, NullTVB, offset+6, 6, &pd[offset+6]);
 182     proto_tree_add_ether_hidden(fh_tree, hf_isl_addr, NullTVB, offset+6, 6, &pd[offset+6]);
 183     length = pntohs(&pd[offset+12]);
 184     proto_tree_add_uint(fh_tree, hf_isl_len, NullTVB, offset+12, 2, length);
 185
 186     /* This part looks sort of like a SNAP-encapsulated LLC header... */
 187     proto_tree_add_text(fh_tree, NullTVB, offset+14, 1, "DSAP: 0x%X", pd[offset+14]);
 188     proto_tree_add_text(fh_tree, NullTVB, offset+15, 1, "SSAP: 0x%X", pd[offset+15]);
 189     proto_tree_add_text(fh_tree, NullTVB, offset+16, 1, "Control: 0x%X", pd[offset+16]);
 190
 191     /* ...but this is the manufacturer's ID portion of the source address
 192        field (which is, admittedly, an OUI). */
 193     proto_tree_add_uint(fh_tree, hf_isl_hsa, NullTVB, offset+17, 3,
 194                 pd[offset+17] << 16 | pd[offset+18] << 8 | pd[offset+19]);
 195     proto_tree_add_uint(fh_tree, hf_isl_vlan_id, NullTVB, offset+20, 2,
 196                         pntohs(&pd[offset+20]));
 197     proto_tree_add_boolean(fh_tree, hf_isl_bpdu, NullTVB, offset+20, 2,
 198                         pntohs(&pd[offset+20]));
 199     proto_tree_add_uint(fh_tree, hf_isl_index, NullTVB, offset+22, 2,
 200         pntohs(&pd[offset+22]));
 201
 202     /* Now for the CRC, which is at the *end* of the packet. */
 203     if (BYTES_ARE_IN_FRAME(pi.len - 4, 4)) {
 204       proto_tree_add_uint(fh_tree, hf_isl_crc, NullTVB, pi.len - 4, 4,
 205         pntohl(&pd[END_OF_FRAME - 4]));
 206     }
 207   }
 208
 209   switch (type) {
 210
 211   case TYPE_ETHER:
 212     next_tvb = tvb_create_from_top(offset+26);
 213     dissect_eth(next_tvb, &pi, tree);
 214     break;
 215
 216   case TYPE_TR:
 217     proto_tree_add_uint(fh_tree, hf_isl_src_vlan_id, NullTVB, offset+24, 2,
 218                         pntohs(&pd[offset+24]));
 219     proto_tree_add_boolean(fh_tree, hf_isl_explorer, NullTVB, offset+24, 2,
 220                         pntohs(&pd[offset+24]));
 221     proto_tree_add_uint(fh_tree, hf_isl_dst_route_descriptor, NullTVB, offset+26, 2,
 222                         pntohs(&pd[offset+26]));
 223     proto_tree_add_uint(fh_tree, hf_isl_src_route_descriptor, NullTVB, offset+28, 2,
 224                         pntohs(&pd[offset+28]));
 225     proto_tree_add_boolean(fh_tree, hf_isl_fcs_not_incl, NullTVB, offset+30, 1,
 226                         pd[offset+30]);
 227     proto_tree_add_uint(fh_tree, hf_isl_esize, NullTVB, offset+16, 1,
 228                         pd[offset+30]);
 229     next_tvb = tvb_create_from_top(offset+31);
 230     dissect_tr(next_tvb, &pi, tree);
 231     break;
 232
 233   default:
 234     next_tvb = tvb_create_from_top(offset+26);
 235     dissect_data_tvb(next_tvb, &pi, tree);
 236     break;
 237   }
 238 }
 239
 240 void
 241 proto_register_isl(void)
 242 {
 243   static hf_register_info hf[] = {
 244         { &hf_isl_dst,
 245         { "Destination",        "isl.dst", FT_ETHER, BASE_NONE, NULL, 0x0,
 246                 "Destination Address" }},
 247         { &hf_isl_type,
 248         { "Type",               "isl.type", FT_UINT8, BASE_NONE,
 249                 VALS(type_vals), 0xF0, "Type" }},
 250         { &hf_isl_user_eth,
 251         { "User",               "isl.user_eth", FT_UINT8, BASE_NONE,
 252                 VALS(ether_user_vals), 0x0F, "Priority (for Ethernet)" }},
 253         { &hf_isl_user,
 254         { "User",               "isl.user", FT_UINT8, BASE_HEX, NULL, 0x0F,
 255                 "User-defined bits" }},
 256         { &hf_isl_src,
 257         { "Source",             "isl.src", FT_ETHER, BASE_NONE, NULL, 0x0,
 258                 "Source Hardware Address" }},
 259         { &hf_isl_addr,
 260         { "Source or Destination Address", "isl.addr", FT_ETHER, BASE_NONE, NULL, 0x0,
 261                 "Source or Destination Hardware Address" }},
 262         { &hf_isl_len,
 263         { "Length",             "isl.len", FT_UINT16, BASE_DEC, NULL, 0x0,
 264                 "" }},
 265         { &hf_isl_hsa,
 266         { "HSA",                "isl.hsa", FT_UINT24, BASE_HEX, NULL, 0x0,
 267                 "High bits of source address" }},
 268         { &hf_isl_vlan_id,
 269         { "VLAN ID",            "isl.vlan_id", FT_UINT16, BASE_HEX, NULL,
 270                 0xFFFE, "Virtual LAN ID" }},
 271         { &hf_isl_bpdu,
 272         { "BPDU",               "isl.bpdu", FT_BOOLEAN, 16,
 273                 TFS(&bpdu_tfs), 0x0001, "BPDU indicator" }},
 274         { &hf_isl_index,
 275         { "Index",              "isl.index", FT_UINT16, BASE_DEC, NULL, 0x0,
 276                 "Port index of packet source" }},
 277         { &hf_isl_crc,
 278         { "CRC",                "isl.crc", FT_UINT32, BASE_HEX, NULL, 0x0,
 279                 "CRC field of encapsulated frame" }},
 280         { &hf_isl_src_vlan_id,
 281         { "Source VLAN ID",     "isl.src_vlan_id", FT_UINT16, BASE_HEX, NULL,
 282                 0xFFFE, "Source Virtual LAN ID" }},
 283         { &hf_isl_explorer,
 284         { "Explorer",           "isl.explorer", FT_BOOLEAN, 16,
 285                 TFS(&explorer_tfs), 0x0001, "Explorer" }},
 286         { &hf_isl_dst_route_descriptor,
 287         { "Destination route descriptor",       "isl.dst_route_desc",
 288                 FT_UINT16, BASE_HEX, NULL, 0x0,
 289                 "Route descriptor to be used for forwarding" }},
 290         { &hf_isl_src_route_descriptor,
 291         { "Source-route descriptor",    "isl.src_route_desc",
 292                 FT_UINT16, BASE_HEX, NULL, 0x0,
 293                 "Route descriptor to be used for source learning" }},
 294         { &hf_isl_fcs_not_incl,
 295         { "FCS Not Included",   "isl.fcs_not_incl", FT_BOOLEAN, 9,
 296                 NULL, 0x40, "FCS not included" }},
 297         { &hf_isl_esize,
 298         { "Esize",      "isl.esize", FT_UINT8, BASE_DEC, NULL,
 299                 0x3F, "Frame size for frames less than 64 bytes" }},
 300   };
 301   static gint *ett[] = {
 302         &ett_isl,
 303   };
 304
 305   proto_isl = proto_register_protocol("Cisco ISL", "isl");
 306   proto_register_field_array(proto_isl, hf, array_length(hf));
 307   proto_register_subtree_array(ett, array_length(ett));
 308 }