epan/dissectors/packet-cisco-erspan.c

   1 /* packet-erspan.c
   2  * Routines for the disassembly of Cisco's ERSPAN protocol
   3  *
   4  * $Id$
   5  *
   6  * Copyright 2005 Joerg Mayer (see AUTHORS file)
   7  *
   8  * Wireshark - Network traffic analyzer
   9  * By Gerald Combs <gerald@wireshark.org>
  10  * Copyright 1998 Gerald Combs
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
  25  */
  26
  27 /*
  28  * TODO:
  29  *      Find out the Unknown values
  30  *
  31  * Specs:
  32  *      No real specs exist. Some general description can be found at:
  33  *      http://www.cisco.com/en/US/products/hw/routers/ps368/products_configuration_guide_chapter09186a008069952a.html
  34  *
  35  *      For ERSPAN packets, the "protocol type" field value in the GRE header
  36  *      is 0x88BE.
  37  *
  38  * 0000000: d4c3 b2a1 0200 0400 0000 0000 0000 0000 <-- pcap header
  39  * 0000010: ffff 0000
  40  * 0000010:           7100 0000 <-- 0x71 (DLT_TYPE) = linux_cooked_capture (of course not)
  41  * 0000010:                     7507 f845 11d1 0500 <-- pcap record header
  42  * 0000020: 7a00 0000 7a00 0000
  43  * 0000020:                     0000 030a 0000 0000 <-- unknown
  44  * 0000030: 0000 0000
  45  * 0000030:           0000 88be <-- GRE header
  46  * 0000030:                     1002 0001 0000 0380 <-- ERSPAN header (01: erspan-id)
  47  * 0000040: 00d0 b7a7 7480 0015 c721 75c0 0800 4500 <-- Ethernet packet
  48  * ...
  49  *
  50  *
  51  */
  52
  53 #ifdef HAVE_CONFIG_H
  54 #  include "config.h"
  55 #endif
  56
  57 #include <glib.h>
  58 #include <epan/packet.h>
  59 #include <epan/greproto.h>
  60
  61 static int proto_erspan = -1;
  62
  63 static gint ett_erspan = -1;
  64
  65 static int hf_erspan_unknown1 = -1;
  66 static int hf_erspan_vlan = -1;
  67 static int hf_erspan_priority = -1;
  68 static int hf_erspan_unknown2 = -1;
  69 static int hf_erspan_direction = -1;
  70 static int hf_erspan_unknown3 = -1;
  71 static int hf_erspan_spanid = -1;
  72 static int hf_erspan_unknown4 = -1;
  73
  74 #define PROTO_SHORT_NAME "ERSPAN"
  75 #define PROTO_LONG_NAME "ER Switch Packet Analysis"
  76
  77 #define ERSPAN_DIRECTION_INCOMING 0
  78 #define ERSPAN_DIRECTION_OUTGOING 1
  79 static const value_string erspan_direction_vals[] = {
  80         {ERSPAN_DIRECTION_INCOMING, "Incoming"},
  81         {ERSPAN_DIRECTION_OUTGOING, "Outgoing"},
  82         {0, NULL},
  83 };
  84
  85 static dissector_handle_t ethnofcs_handle;
  86
  87 static void
  88 dissect_erspan(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree)
  89 {
  90         proto_item *ti;
  91         proto_tree *erspan_tree = NULL;
  92         tvbuff_t *eth_tvb;
  93         guint32 offset = 0;
  94
  95         if (check_col(pinfo->cinfo, COL_PROTOCOL))
  96                 col_set_str(pinfo->cinfo, COL_PROTOCOL, PROTO_SHORT_NAME);
  97         if (check_col(pinfo->cinfo, COL_INFO))
  98                 col_set_str(pinfo->cinfo, COL_INFO, PROTO_SHORT_NAME ":");
  99
 100         if (tree) {
 101                 ti = proto_tree_add_item(tree, proto_erspan, tvb, offset, -1,
 102                     FALSE);
 103                 erspan_tree = proto_item_add_subtree(ti, ett_erspan);
 104
 105                 proto_tree_add_item(erspan_tree, hf_erspan_unknown1, tvb, offset, 2,
 106                         FALSE);
 107
 108                 proto_tree_add_item(erspan_tree, hf_erspan_vlan, tvb, offset, 2,
 109                         FALSE);
 110                 offset += 2;
 111
 112                 proto_tree_add_item(erspan_tree, hf_erspan_priority, tvb, offset, 2,
 113                         FALSE);
 114
 115                 proto_tree_add_item(erspan_tree, hf_erspan_unknown2, tvb, offset, 2,
 116                         FALSE);
 117
 118                 proto_tree_add_item(erspan_tree, hf_erspan_direction, tvb, offset, 2,
 119                         FALSE);
 120
 121                 proto_tree_add_item(erspan_tree, hf_erspan_unknown3, tvb, offset, 2,
 122                         FALSE);
 123
 124                 proto_tree_add_item(erspan_tree, hf_erspan_spanid, tvb, offset, 2,
 125                         FALSE);
 126                 offset += 2;
 127
 128                 proto_tree_add_item(erspan_tree, hf_erspan_unknown4, tvb, offset, 4,
 129                         FALSE);
 130                 offset += 4;
 131
 132                 eth_tvb = tvb_new_subset(tvb, offset, -1, -1);
 133                 call_dissector(ethnofcs_handle, eth_tvb, pinfo, tree);
 134         }
 135 }
 136
 137 void
 138 proto_register_erspan(void)
 139 {
 140         static hf_register_info hf[] = {
 141
 142                 { &hf_erspan_unknown1,
 143                 { "Unknown1",   "erspan.unknown1", FT_UINT16, BASE_HEX, NULL,
 144                         0xf000, "", HFILL }},
 145
 146                 { &hf_erspan_vlan,
 147                 { "Vlan",       "erspan.vlan", FT_UINT16, BASE_DEC, NULL,
 148                         0x0fff, "", HFILL }},
 149
 150                 { &hf_erspan_priority,
 151                 { "Priority",   "erspan.priority", FT_UINT16, BASE_DEC, NULL,
 152                         0xe000, "", HFILL }},
 153
 154                 { &hf_erspan_unknown2,
 155                 { "Unknown2",   "erspan.unknown2", FT_UINT16, BASE_DEC, NULL,
 156                         0x1000, "", HFILL }},
 157
 158                 { &hf_erspan_direction,
 159                 { "Direction",  "erspan.direction", FT_UINT16, BASE_DEC, VALS(erspan_direction_vals),
 160                         0x0800, "", HFILL }},
 161
 162                 { &hf_erspan_unknown3,
 163                 { "Unknown3",   "erspan.unknown3", FT_UINT16, BASE_DEC, NULL,
 164                         0x0400, "", HFILL }},
 165
 166                 { &hf_erspan_spanid,
 167                 { "SpanID",     "erspan.spanid", FT_UINT16, BASE_DEC, NULL,
 168                         0x03ff, "", HFILL }},
 169
 170                 { &hf_erspan_unknown4,
 171                 { "Unknown4",   "erspan.unknown4", FT_BYTES, BASE_NONE, NULL,
 172                         0, "", HFILL }},
 173
 174         };
 175         static gint *ett[] = {
 176                 &ett_erspan,
 177         };
 178
 179         proto_erspan = proto_register_protocol(PROTO_LONG_NAME,
 180             PROTO_SHORT_NAME, "erspan");
 181         proto_register_field_array(proto_erspan, hf, array_length(hf));
 182         proto_register_subtree_array(ett, array_length(ett));
 183 }
 184
 185 void
 186 proto_reg_handoff_erspan(void)
 187 {
 188         dissector_handle_t erspan_handle;
 189
 190         ethnofcs_handle = find_dissector("eth_withoutfcs");
 191
 192         erspan_handle = create_dissector_handle(dissect_erspan, proto_erspan);
 193         dissector_add("gre.proto", GRE_ERSPAN, erspan_handle);
 194
 195 }
 196