packet-isl.c

   1 /* packet-isl.c
   2  * Routines for Cisco ISL Ethernet header disassembly
   3  *
   4  * $Id: packet-isl.c,v 1.17 2000/11/19 08:53:58 guy 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   OLD_CHECK_DISPLAY_AS_DATA(proto_isl, pd, offset, fd, tree);
 150
 151   if (!BYTES_ARE_IN_FRAME(offset, ISL_HEADER_SIZE)) {
 152     old_dissect_data(pd, offset, fd, tree);
 153     return;
 154   }
 155
 156   if (check_col(fd, COL_PROTOCOL))
 157     col_set_str(fd, COL_PROTOCOL, "ISL");
 158   if (check_col(fd, COL_INFO))
 159     col_add_fstr(fd, COL_INFO, "VLAN ID: 0x%04X", pntohs(&pd[offset+20]) >> 1);
 160
 161   type = (pd[offset+5] >> 4)&0x0F;
 162
 163   if (tree) {
 164     ti = proto_tree_add_protocol_format(tree, proto_isl, NullTVB, offset, ISL_HEADER_SIZE,
 165                 "ISL");
 166     fh_tree = proto_item_add_subtree(ti, ett_isl);
 167     proto_tree_add_ether(fh_tree, hf_isl_dst, NullTVB, offset+0, 6, &pd[offset+0]);
 168     proto_tree_add_ether_hidden(fh_tree, hf_isl_addr, NullTVB, offset+0, 6, &pd[offset+0]);
 169     proto_tree_add_uint(fh_tree, hf_isl_type, NullTVB, offset+5, 1, pd[offset+5]);
 170     switch (type) {
 171
 172     case TYPE_ETHER:
 173       proto_tree_add_uint(fh_tree, hf_isl_user_eth, NullTVB, offset+5, 1,
 174                         pd[offset+5]&0x03);
 175       break;
 176
 177     default:
 178       /* XXX - the spec appears to indicate that the "User" field is
 179          used for TYPE_TR to distinguish between types of packets. */
 180       proto_tree_add_uint(fh_tree, hf_isl_user, NullTVB, offset+5, 1, pd[offset+5]);
 181       break;
 182     }
 183     proto_tree_add_ether(fh_tree, hf_isl_src, NullTVB, offset+6, 6, &pd[offset+6]);
 184     proto_tree_add_ether_hidden(fh_tree, hf_isl_addr, NullTVB, offset+6, 6, &pd[offset+6]);
 185     length = pntohs(&pd[offset+12]);
 186     proto_tree_add_uint(fh_tree, hf_isl_len, NullTVB, offset+12, 2, length);
 187
 188     /* This part looks sort of like a SNAP-encapsulated LLC header... */
 189     proto_tree_add_text(fh_tree, NullTVB, offset+14, 1, "DSAP: 0x%X", pd[offset+14]);
 190     proto_tree_add_text(fh_tree, NullTVB, offset+15, 1, "SSAP: 0x%X", pd[offset+15]);
 191     proto_tree_add_text(fh_tree, NullTVB, offset+16, 1, "Control: 0x%X", pd[offset+16]);
 192
 193     /* ...but this is the manufacturer's ID portion of the source address
 194        field (which is, admittedly, an OUI). */
 195     proto_tree_add_uint(fh_tree, hf_isl_hsa, NullTVB, offset+17, 3,
 196                 pd[offset+17] << 16 | pd[offset+18] << 8 | pd[offset+19]);
 197     proto_tree_add_uint(fh_tree, hf_isl_vlan_id, NullTVB, offset+20, 2,
 198                         pntohs(&pd[offset+20]));
 199     proto_tree_add_boolean(fh_tree, hf_isl_bpdu, NullTVB, offset+20, 2,
 200                         pntohs(&pd[offset+20]));
 201     proto_tree_add_uint(fh_tree, hf_isl_index, NullTVB, offset+22, 2,
 202         pntohs(&pd[offset+22]));
 203
 204     /* Now for the CRC, which is at the *end* of the packet. */
 205     if (BYTES_ARE_IN_FRAME(pi.len - 4, 4)) {
 206       proto_tree_add_uint(fh_tree, hf_isl_crc, NullTVB, pi.len - 4, 4,
 207         pntohl(&pd[END_OF_FRAME - 4]));
 208     }
 209   }
 210
 211   switch (type) {
 212
 213   case TYPE_ETHER:
 214     next_tvb = tvb_create_from_top(offset+26);
 215     dissect_eth(next_tvb, &pi, tree);
 216     break;
 217
 218   case TYPE_TR:
 219     proto_tree_add_uint(fh_tree, hf_isl_src_vlan_id, NullTVB, offset+24, 2,
 220                         pntohs(&pd[offset+24]));
 221     proto_tree_add_boolean(fh_tree, hf_isl_explorer, NullTVB, offset+24, 2,
 222                         pntohs(&pd[offset+24]));
 223     proto_tree_add_uint(fh_tree, hf_isl_dst_route_descriptor, NullTVB, offset+26, 2,
 224                         pntohs(&pd[offset+26]));
 225     proto_tree_add_uint(fh_tree, hf_isl_src_route_descriptor, NullTVB, offset+28, 2,
 226                         pntohs(&pd[offset+28]));
 227     proto_tree_add_boolean(fh_tree, hf_isl_fcs_not_incl, NullTVB, offset+30, 1,
 228                         pd[offset+30]);
 229     proto_tree_add_uint(fh_tree, hf_isl_esize, NullTVB, offset+16, 1,
 230                         pd[offset+30]);
 231     next_tvb = tvb_create_from_top(offset+31);
 232     dissect_tr(next_tvb, &pi, tree);
 233     break;
 234
 235   default:
 236     next_tvb = tvb_create_from_top(offset+26);
 237     dissect_data(next_tvb, 0, &pi, tree);
 238     break;
 239   }
 240 }
 241
 242 void
 243 proto_register_isl(void)
 244 {
 245   static hf_register_info hf[] = {
 246         { &hf_isl_dst,
 247         { "Destination",        "isl.dst", FT_ETHER, BASE_NONE, NULL, 0x0,
 248                 "Destination Address" }},
 249         { &hf_isl_type,
 250         { "Type",               "isl.type", FT_UINT8, BASE_NONE,
 251                 VALS(type_vals), 0xF0, "Type" }},
 252         { &hf_isl_user_eth,
 253         { "User",               "isl.user_eth", FT_UINT8, BASE_NONE,
 254                 VALS(ether_user_vals), 0x0F, "Priority (for Ethernet)" }},
 255         { &hf_isl_user,
 256         { "User",               "isl.user", FT_UINT8, BASE_HEX, NULL, 0x0F,
 257                 "User-defined bits" }},
 258         { &hf_isl_src,
 259         { "Source",             "isl.src", FT_ETHER, BASE_NONE, NULL, 0x0,
 260                 "Source Hardware Address" }},
 261         { &hf_isl_addr,
 262         { "Source or Destination Address", "isl.addr", FT_ETHER, BASE_NONE, NULL, 0x0,
 263                 "Source or Destination Hardware Address" }},
 264         { &hf_isl_len,
 265         { "Length",             "isl.len", FT_UINT16, BASE_DEC, NULL, 0x0,
 266                 "" }},
 267         { &hf_isl_hsa,
 268         { "HSA",                "isl.hsa", FT_UINT24, BASE_HEX, NULL, 0x0,
 269                 "High bits of source address" }},
 270         { &hf_isl_vlan_id,
 271         { "VLAN ID",            "isl.vlan_id", FT_UINT16, BASE_HEX, NULL,
 272                 0xFFFE, "Virtual LAN ID" }},
 273         { &hf_isl_bpdu,
 274         { "BPDU",               "isl.bpdu", FT_BOOLEAN, 16,
 275                 TFS(&bpdu_tfs), 0x0001, "BPDU indicator" }},
 276         { &hf_isl_index,
 277         { "Index",              "isl.index", FT_UINT16, BASE_DEC, NULL, 0x0,
 278                 "Port index of packet source" }},
 279         { &hf_isl_crc,
 280         { "CRC",                "isl.crc", FT_UINT32, BASE_HEX, NULL, 0x0,
 281                 "CRC field of encapsulated frame" }},
 282         { &hf_isl_src_vlan_id,
 283         { "Source VLAN ID",     "isl.src_vlan_id", FT_UINT16, BASE_HEX, NULL,
 284                 0xFFFE, "Source Virtual LAN ID" }},
 285         { &hf_isl_explorer,
 286         { "Explorer",           "isl.explorer", FT_BOOLEAN, 16,
 287                 TFS(&explorer_tfs), 0x0001, "Explorer" }},
 288         { &hf_isl_dst_route_descriptor,
 289         { "Destination route descriptor",       "isl.dst_route_desc",
 290                 FT_UINT16, BASE_HEX, NULL, 0x0,
 291                 "Route descriptor to be used for forwarding" }},
 292         { &hf_isl_src_route_descriptor,
 293         { "Source-route descriptor",    "isl.src_route_desc",
 294                 FT_UINT16, BASE_HEX, NULL, 0x0,
 295                 "Route descriptor to be used for source learning" }},
 296         { &hf_isl_fcs_not_incl,
 297         { "FCS Not Included",   "isl.fcs_not_incl", FT_BOOLEAN, 9,
 298                 NULL, 0x40, "FCS not included" }},
 299         { &hf_isl_esize,
 300         { "Esize",      "isl.esize", FT_UINT8, BASE_DEC, NULL,
 301                 0x3F, "Frame size for frames less than 64 bytes" }},
 302   };
 303   static gint *ett[] = {
 304         &ett_isl,
 305   };
 306
 307   proto_isl = proto_register_protocol("Cisco ISL", "isl");
 308   proto_register_field_array(proto_isl, hf, array_length(hf));
 309   proto_register_subtree_array(ett, array_length(ett));
 310 }