packet-isl.c

   1 /* packet-isl.c
   2  * Routines for Cisco ISL Ethernet header disassembly
   3  *
   4  * $Id: packet-isl.c,v 1.4 2000/01/24 21:56:24 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 "etypes.h"
  41
  42 /*
  43  * See
  44  *
  45  *      http://www.cisco.com/warp/public/741/4.html
  46  *
  47  * and
  48  *
  49  *      http://www.cisco.com/univercd/cc/td/doc/product/lan/trsrb/frames.htm
  50  *
  51  * for information on ISL.
  52  */
  53 static int proto_isl = -1;
  54 static int hf_isl_dst = -1;
  55 static int hf_isl_type = -1;
  56 static int hf_isl_user_eth = -1;
  57 static int hf_isl_user = -1;
  58 static int hf_isl_src = -1;
  59 static int hf_isl_len = -1;
  60 static int hf_isl_hsa = -1;
  61 static int hf_isl_vlan_id = -1;
  62 static int hf_isl_bpdu = -1;
  63 static int hf_isl_index = -1;
  64 static int hf_isl_crc = -1;
  65 static int hf_isl_src_vlan_id = -1;
  66 static int hf_isl_explorer = -1;
  67 static int hf_isl_dst_route_descriptor = -1;
  68 static int hf_isl_src_route_descriptor = -1;
  69 static int hf_isl_fcs_not_incl = -1;
  70 static int hf_isl_esize = -1;
  71
  72 static gint ett_isl = -1;
  73
  74 #define ISL_HEADER_SIZE 26
  75
  76 #define TYPE_ETHER      0x0
  77 #define TYPE_TR         0x1
  78 #define TYPE_FDDI       0x2
  79 #define TYPE_ATM        0x3
  80
  81 void
  82 capture_isl(const u_char *pd, int offset, packet_counts *ld)
  83 {
  84   guint8 type;
  85
  86   if (!BYTES_ARE_IN_FRAME(offset, ISL_HEADER_SIZE)) {
  87     ld->other++;
  88     return;
  89   }
  90
  91   type = (pd[offset+5] >> 4)&0x0F;
  92
  93   switch (type) {
  94
  95   case TYPE_ETHER:
  96     offset += 14+12;    /* skip the header */
  97     capture_eth(pd, offset, ld);
  98     break;
  99
 100   case TYPE_TR:
 101     offset += 14+17;    /* skip the header */
 102     capture_tr(pd, offset, ld);
 103     break;
 104
 105   default:
 106     ld->other++;
 107     break;
 108   }
 109 }
 110
 111 static const value_string type_vals[] = {
 112         {TYPE_ETHER, "Ethernet"},
 113         {TYPE_TR,    "Token-Ring"},
 114         {TYPE_FDDI,  "FDDI"},
 115         {TYPE_ATM,   "ATM"},
 116         {0,          NULL}
 117 };
 118
 119 static const value_string ether_user_vals[] = {
 120         {0x0, "Normal priority"},
 121         {0x1, "Priority 1"},
 122         {0x2, "Priority 2"},
 123         {0x3, "Highest priority"},
 124         {0,   NULL}
 125 };
 126
 127 static const true_false_string bpdu_tfs = {
 128         "Yes",
 129         "No"
 130 };
 131
 132 static const true_false_string explorer_tfs = {
 133         "Explorer frame",
 134         "Data frame"
 135 };
 136
 137 void
 138 dissect_isl(const u_char *pd, int offset, frame_data *fd, proto_tree *tree)
 139 {
 140   proto_tree *fh_tree = NULL;
 141   proto_item *ti;
 142   guint8 type;
 143   guint16 length;
 144
 145   if (!BYTES_ARE_IN_FRAME(offset, ISL_HEADER_SIZE)) {
 146     dissect_data(pd, offset, fd, tree);
 147     return;
 148   }
 149
 150   if (check_col(fd, COL_PROTOCOL))
 151     col_add_str(fd, COL_PROTOCOL, "ISL");
 152   if (check_col(fd, COL_INFO))
 153     col_add_fstr(fd, COL_INFO, "VLAN ID: 0x%04X", pntohs(&pd[offset+20]) >> 1);
 154
 155   type = (pd[offset+5] >> 4)&0x0F;
 156
 157   if (tree) {
 158     ti = proto_tree_add_item_format(tree, proto_isl, offset, ISL_HEADER_SIZE,
 159                 NULL, "ISL");
 160     fh_tree = proto_item_add_subtree(ti, ett_isl);
 161     proto_tree_add_item(fh_tree, hf_isl_dst, offset+0, 6, &pd[offset+0]);
 162     proto_tree_add_item(fh_tree, hf_isl_type, offset+5, 1, pd[offset+5]);
 163     switch (type) {
 164
 165     case TYPE_ETHER:
 166       proto_tree_add_item(fh_tree, hf_isl_user_eth, offset+5, 1,
 167                         pd[offset+5]&0x03);
 168       break;
 169
 170     default:
 171       /* XXX - the spec appears to indicate that the "User" field is
 172          used for TYPE_TR to distinguish between types of packets. */
 173       proto_tree_add_item(fh_tree, hf_isl_user, offset+5, 1, pd[offset+5]);
 174       break;
 175     }
 176     proto_tree_add_item(fh_tree, hf_isl_src, offset+6, 6, &pd[offset+6]);
 177     length = pntohs(&pd[offset+12]);
 178     proto_tree_add_item(fh_tree, hf_isl_len, offset+12, 2, length);
 179
 180     /* This part looks sort of like a SNAP-encapsulated LLC header... */
 181     proto_tree_add_text(fh_tree, offset+14, 1, "DSAP: 0x%X", pd[offset+14]);
 182     proto_tree_add_text(fh_tree, offset+15, 1, "SSAP: 0x%X", pd[offset+15]);
 183     proto_tree_add_text(fh_tree, offset+16, 1, "Control: 0x%X", pd[offset+16]);
 184
 185     /* ...but this is the manufacturer's ID portion of the source address
 186        field (which is, admittedly, an OUI). */
 187     proto_tree_add_item(fh_tree, hf_isl_hsa, offset+17, 3,
 188                 pd[offset+17] << 16 | pd[offset+18] << 8 | pd[offset+19]);
 189     proto_tree_add_item(fh_tree, hf_isl_vlan_id, offset+20, 2,
 190                         pntohs(&pd[offset+20]));
 191     proto_tree_add_item(fh_tree, hf_isl_bpdu, offset+20, 2,
 192                         pntohs(&pd[offset+20]));
 193     proto_tree_add_item(fh_tree, hf_isl_index, offset+22, 2,
 194         pntohs(&pd[offset+22]));
 195
 196     /* Now for the CRC, which is at the *end* of the packet. */
 197     if (BYTES_ARE_IN_FRAME(pi.len - 4, 4)) {
 198       proto_tree_add_item(fh_tree, hf_isl_crc, pi.len - 4, 4,
 199         pntohl(&pd[END_OF_FRAME - 4]));
 200     }
 201   }
 202
 203   switch (type) {
 204
 205   case TYPE_ETHER:
 206     dissect_eth(pd, offset+26, fd, tree);
 207     break;
 208
 209   case TYPE_TR:
 210     proto_tree_add_item(fh_tree, hf_isl_src_vlan_id, offset+24, 2,
 211                         pntohs(&pd[offset+24]));
 212     proto_tree_add_item(fh_tree, hf_isl_explorer, offset+24, 2,
 213                         pntohs(&pd[offset+24]));
 214     proto_tree_add_item(fh_tree, hf_isl_dst_route_descriptor, offset+26, 2,
 215                         pntohs(&pd[offset+26]));
 216     proto_tree_add_item(fh_tree, hf_isl_src_route_descriptor, offset+28, 2,
 217                         pntohs(&pd[offset+28]));
 218     proto_tree_add_item(fh_tree, hf_isl_fcs_not_incl, offset+30, 1,
 219                         pd[offset+30]);
 220     proto_tree_add_item(fh_tree, hf_isl_esize, offset+16, 1,
 221                         pd[offset+30]);
 222     dissect_tr(pd, offset+31, fd, tree);
 223     break;
 224
 225   default:
 226     dissect_data(pd, offset+26, fd, tree);
 227     break;
 228   }
 229 }
 230
 231 void
 232 proto_register_isl(void)
 233 {
 234   static hf_register_info hf[] = {
 235         { &hf_isl_dst,
 236         { "Destination",        "isl.dst", FT_ETHER, BASE_NONE, NULL, 0x0,
 237                 "Destination Address" }},
 238         { &hf_isl_type,
 239         { "Type",               "isl.type", FT_UINT8, BASE_NONE,
 240                 VALS(type_vals), 0xF0, "Type" }},
 241         { &hf_isl_user_eth,
 242         { "User",               "isl.user_eth", FT_UINT8, BASE_NONE,
 243                 VALS(ether_user_vals), 0x0F, "Priority (for Ethernet)" }},
 244         { &hf_isl_user,
 245         { "User",               "isl.user", FT_UINT8, BASE_HEX, NULL, 0x0F,
 246                 "User-defined bits" }},
 247         { &hf_isl_src,
 248         { "Source",             "isl.src", FT_ETHER, BASE_NONE, NULL, 0x0,
 249                 "Source Hardware Address" }},
 250         { &hf_isl_len,
 251         { "Length",             "isl.len", FT_UINT16, BASE_DEC, NULL, 0x0,
 252                 "" }},
 253         { &hf_isl_hsa,
 254         { "HSA",                "isl.hsa", FT_UINT24, BASE_HEX, NULL, 0x0,
 255                 "High bits of source address" }},
 256         { &hf_isl_vlan_id,
 257         { "VLAN ID",            "isl.vlan_id", FT_UINT16, BASE_HEX, NULL,
 258                 0xFFFE, "Virtual LAN ID" }},
 259         { &hf_isl_bpdu,
 260         { "BPDU",               "isl.bpdu", FT_BOOLEAN, 16,
 261                 TFS(&bpdu_tfs), 0x0001, "BPDU indicator" }},
 262         { &hf_isl_index,
 263         { "Index",              "isl.index", FT_UINT16, BASE_DEC, NULL, 0x0,
 264                 "Port index of packet source" }},
 265         { &hf_isl_crc,
 266         { "CRC",                "isl.crc", FT_UINT32, BASE_HEX, NULL, 0x0,
 267                 "CRC field of encapsulated frame" }},
 268         { &hf_isl_src_vlan_id,
 269         { "Source VLAN ID",     "isl.src_vlan_id", FT_UINT16, BASE_HEX, NULL,
 270                 0xFFFE, "Source Virtual LAN ID" }},
 271         { &hf_isl_explorer,
 272         { "Explorer",           "isl.explorer", FT_BOOLEAN, 16,
 273                 TFS(&explorer_tfs), 0x0001, "Explorer" }},
 274         { &hf_isl_dst_route_descriptor,
 275         { "Destination route descriptor",       "isl.dst_route_desc",
 276                 FT_UINT16, BASE_HEX, NULL, 0x0,
 277                 "Route descriptor to be used for forwarding" }},
 278         { &hf_isl_src_route_descriptor,
 279         { "Source-route descriptor",    "isl.src_route_desc",
 280                 FT_UINT16, BASE_HEX, NULL, 0x0,
 281                 "Route descriptor to be used for source learning" }},
 282         { &hf_isl_fcs_not_incl,
 283         { "FCS Not Included",   "isl.fcs_not_incl", FT_BOOLEAN, 9,
 284                 NULL, 0x40, "FCS not included" }},
 285         { &hf_isl_esize,
 286         { "Esize",      "isl.esize", FT_UINT8, BASE_DEC, NULL,
 287                 0x3F, "Frame size for frames less than 64 bytes" }},
 288   };
 289   static gint *ett[] = {
 290         &ett_isl,
 291   };
 292
 293   proto_isl = proto_register_protocol("Cisco ISL", "isl");
 294   proto_register_field_array(proto_isl, hf, array_length(hf));
 295   proto_register_subtree_array(ett, array_length(ett));
 296 }