epan/dissectors/packet-ieee80211-netmon.c

   1 /*
   2  *  packet-ieee80211-netmon.c
   3  *       Decode packets with a Network Monitor 802.11 radio header
   4  *
   5  * $Id$
   6  *
   7  * Wireshark - Network traffic analyzer
   8  * By Gerald Combs <gerald@wireshark.org>
   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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  24  */
  25
  26 #include "config.h"
  27
  28 #include <glib.h>
  29
  30 #include <epan/packet.h>
  31
  32 /* protocol */
  33 static int proto_netmon_802_11 = -1;
  34
  35 #define MIN_HEADER_LEN  32
  36
  37 /* op_mode */
  38 #define OP_MODE_STA     0x00000001      /* station mode */
  39 #define OP_MODE_AP      0x00000002      /* AP mode */
  40 #define OP_MODE_STA_EXT 0x00000004      /* extensible station mode */
  41 #define OP_MODE_MON     0x80000000      /* monitor mode */
  42
  43 /* phy_type */
  44 #define PHY_TYPE_11A    4
  45 #define PHY_TYPE_11B    5
  46 #define PHY_TYPE_11G    6
  47 #define PHY_TYPE_11N    7
  48
  49 static int hf_netmon_802_11_version = -1;
  50 static int hf_netmon_802_11_length = -1;
  51 static int hf_netmon_802_11_op_mode = -1;
  52 static int hf_netmon_802_11_op_mode_sta = -1;
  53 static int hf_netmon_802_11_op_mode_ap = -1;
  54 static int hf_netmon_802_11_op_mode_sta_ext = -1;
  55 static int hf_netmon_802_11_op_mode_mon = -1;
  56 /* static int hf_netmon_802_11_flags = -1; */
  57 static int hf_netmon_802_11_phy_type = -1;
  58 static int hf_netmon_802_11_channel = -1;
  59 static int hf_netmon_802_11_frequency = -1;
  60 static int hf_netmon_802_11_rssi = -1;
  61 static int hf_netmon_802_11_datarate = -1;
  62 static int hf_netmon_802_11_timestamp = -1;
  63
  64 static gint ett_netmon_802_11 = -1;
  65 static gint ett_netmon_802_11_op_mode = -1;
  66
  67 static dissector_handle_t ieee80211_handle;
  68
  69 static int
  70 dissect_netmon_802_11(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
  71 {
  72   proto_tree *wlan_tree, *opmode_tree;
  73   proto_item *ti;
  74   tvbuff_t   *next_tvb;
  75   int         offset;
  76   guint8      version;
  77   guint16     length;
  78   guint32     flags;
  79   guint32     channel;
  80   gint32      rssi;
  81   guint8      rate;
  82
  83   col_set_str(pinfo->cinfo, COL_PROTOCOL, "WLAN");
  84   col_clear(pinfo->cinfo, COL_INFO);
  85   offset = 0;
  86
  87   version = tvb_get_guint8(tvb, offset);
  88   length = tvb_get_letohs(tvb, offset+1);
  89   col_add_fstr(pinfo->cinfo, COL_INFO, "NetMon WLAN Capture v%u, Length %u",
  90                version, length);
  91   if (version != 2) {
  92     /* XXX - complain */
  93     goto skip;
  94   }
  95   if (length < MIN_HEADER_LEN) {
  96     /* XXX - complain */
  97     goto skip;
  98   }
  99
 100   /* Dissect the packet */
 101   if (tree) {
 102     ti = proto_tree_add_item(tree, proto_netmon_802_11, tvb, 0, length,
 103                              ENC_NA);
 104     wlan_tree = proto_item_add_subtree(ti, ett_netmon_802_11);
 105     proto_tree_add_item(wlan_tree, hf_netmon_802_11_version, tvb, offset, 1,
 106                         ENC_LITTLE_ENDIAN);
 107     offset += 1;
 108     proto_tree_add_item(wlan_tree, hf_netmon_802_11_length, tvb, offset, 2,
 109                         ENC_LITTLE_ENDIAN);
 110     offset += 2;
 111     ti = proto_tree_add_item(wlan_tree, hf_netmon_802_11_op_mode, tvb, offset,
 112                         4, ENC_LITTLE_ENDIAN);
 113     opmode_tree = proto_item_add_subtree(ti, ett_netmon_802_11_op_mode);
 114     proto_tree_add_item(opmode_tree, hf_netmon_802_11_op_mode_sta, tvb, offset,
 115                         4, ENC_LITTLE_ENDIAN);
 116     proto_tree_add_item(opmode_tree, hf_netmon_802_11_op_mode_ap, tvb, offset,
 117                         4, ENC_LITTLE_ENDIAN);
 118     proto_tree_add_item(opmode_tree, hf_netmon_802_11_op_mode_sta_ext, tvb,
 119                         offset, 4, ENC_LITTLE_ENDIAN);
 120     proto_tree_add_item(opmode_tree, hf_netmon_802_11_op_mode_mon, tvb, offset,
 121                         4, ENC_LITTLE_ENDIAN);
 122     offset += 4;
 123     flags = tvb_get_letohl(tvb, offset);
 124     offset += 4;
 125     if (flags != 0xffffffff) {
 126       proto_tree_add_item(wlan_tree, hf_netmon_802_11_phy_type, tvb, offset, 4,
 127                           ENC_LITTLE_ENDIAN);
 128       offset += 4;
 129       channel = tvb_get_letohl(tvb, offset);
 130       if (channel < 1000) {
 131         proto_tree_add_uint(wlan_tree, hf_netmon_802_11_channel,
 132                             tvb, offset, 4, channel);
 133       } else {
 134         proto_tree_add_uint_format_value(wlan_tree, hf_netmon_802_11_frequency,
 135                                          tvb, offset, 4, channel,
 136                                          "%u Mhz", channel);
 137       }
 138       offset += 4;
 139       rssi = tvb_get_letohl(tvb, offset);
 140       proto_tree_add_int_format_value(wlan_tree, hf_netmon_802_11_rssi,
 141                                       tvb, offset, 4, rssi,
 142                                       "%d dBm", rssi);
 143       offset += 4;
 144       rate = tvb_get_guint8(tvb, offset);
 145       if (rate == 0) {
 146         proto_tree_add_uint_format_value(wlan_tree, hf_netmon_802_11_datarate,
 147                                          tvb, offset, 1, rate,
 148                                          "Unknown");
 149       } else {
 150         proto_tree_add_uint_format_value(wlan_tree, hf_netmon_802_11_datarate,
 151                                          tvb, offset, 1, rate,
 152                                          "%f Mb/s", rate*.5);
 153       }
 154       offset += 1;
 155     } else
 156       offset += 13;
 157     proto_tree_add_item(wlan_tree, hf_netmon_802_11_timestamp, tvb, offset, 8,
 158                         ENC_LITTLE_ENDIAN);
 159     /*offset += 8;*/
 160
 161   }
 162
 163   /* no return */
 164
 165 skip:
 166   offset = length;
 167
 168   /* dissect the 802.11 header next */
 169   next_tvb = tvb_new_subset_remaining(tvb, offset);
 170   call_dissector(ieee80211_handle, next_tvb, pinfo, tree);
 171   return offset;
 172 }
 173
 174 void
 175 proto_register_netmon_802_11(void)
 176 {
 177   static const value_string phy_type[] = {
 178     { PHY_TYPE_11A, "802.11a" },
 179     { PHY_TYPE_11B, "802.11b" },
 180     { PHY_TYPE_11G, "802.11g" },
 181     { PHY_TYPE_11N, "802.11n" },
 182     { 0, NULL },
 183   };
 184
 185   static hf_register_info hf[] = {
 186     { &hf_netmon_802_11_version, { "Header revision", "netmon_802_11.version", FT_UINT8,
 187                           BASE_DEC, NULL, 0x0, NULL, HFILL } },
 188     { &hf_netmon_802_11_length, { "Header length", "netmon_802_11.length", FT_UINT16,
 189                           BASE_DEC, NULL, 0x0, NULL, HFILL } },
 190     { &hf_netmon_802_11_op_mode, { "Operation mode", "netmon_802_11.op_mode", FT_UINT32,
 191                           BASE_HEX, NULL, 0x0, NULL, HFILL } },
 192     { &hf_netmon_802_11_op_mode_sta, { "Station mode", "netmon_802_11.op_mode.sta", FT_UINT32,
 193                           BASE_HEX, NULL, OP_MODE_STA, NULL, HFILL } },
 194     { &hf_netmon_802_11_op_mode_ap, { "AP mode", "netmon_802_11.op_mode.ap", FT_UINT32,
 195                           BASE_HEX, NULL, OP_MODE_AP, NULL, HFILL } },
 196     { &hf_netmon_802_11_op_mode_sta_ext, { "Extensible station mode", "netmon_802_11.op_mode.sta_ext", FT_UINT32,
 197                           BASE_HEX, NULL, OP_MODE_STA_EXT, NULL, HFILL } },
 198     { &hf_netmon_802_11_op_mode_mon, { "Monitor mode", "netmon_802_11.op_mode.on", FT_UINT32,
 199                           BASE_HEX, NULL, OP_MODE_MON, NULL, HFILL } },
 200 #if 0
 201     { &hf_netmon_802_11_flags, { "Flags", "netmon_802_11.flags", FT_UINT32,
 202                           BASE_HEX, NULL, 0x0, NULL, HFILL } },
 203 #endif
 204     { &hf_netmon_802_11_phy_type, { "PHY type", "netmon_802_11.phy_type", FT_UINT32,
 205                           BASE_DEC, VALS(phy_type), 0x0, NULL, HFILL } },
 206     { &hf_netmon_802_11_channel, { "Channel", "netmon_802_11.channel", FT_UINT32,
 207                           BASE_DEC, NULL, 0x0, NULL, HFILL } },
 208     { &hf_netmon_802_11_frequency, { "Center frequency", "netmon_802_11.frequency", FT_UINT32,
 209                           BASE_DEC, NULL, 0x0, NULL, HFILL } },
 210     { &hf_netmon_802_11_rssi, { "RSSI", "netmon_802_11.rssi", FT_INT32,
 211                           BASE_DEC, NULL, 0x0, NULL, HFILL } },
 212     { &hf_netmon_802_11_datarate, { "Data rate", "netmon_802_11.datarate", FT_UINT32,
 213                           BASE_DEC, NULL, 0x0, NULL, HFILL } },
 214     /*
 215      * XXX - is this host, or MAC, time stamp?
 216      * It might be a FILETIME.
 217      */
 218     { &hf_netmon_802_11_timestamp, { "Timestamp", "netmon_802_11.timestamp", FT_UINT64,
 219                           BASE_DEC, NULL, 0x0, NULL, HFILL } },
 220   };
 221   static gint *ett[] = {
 222     &ett_netmon_802_11,
 223     &ett_netmon_802_11_op_mode
 224   };
 225
 226   proto_netmon_802_11 = proto_register_protocol("NetMon 802.11 capture header",
 227                                                 "NetMon 802.11",
 228                                                 "netmon_802_11");
 229   proto_register_field_array(proto_netmon_802_11, hf, array_length(hf));
 230   proto_register_subtree_array(ett, array_length(ett));
 231 }
 232
 233 void
 234 proto_reg_handoff_netmon_802_11(void)
 235 {
 236   dissector_handle_t netmon_802_11_handle;
 237
 238   /* handle for 802.11 dissector */
 239   ieee80211_handle = find_dissector("wlan");
 240   netmon_802_11_handle = new_create_dissector_handle(dissect_netmon_802_11,
 241                                                  proto_netmon_802_11);
 242   dissector_add_uint("wtap_encap", WTAP_ENCAP_IEEE_802_11_NETMON, netmon_802_11_handle);
 243 }