epan/dissectors/packet-btmesh-beacon.c

   1 /* packet-btmesh-beacon.c
   2  * Routines for Bluetooth mesh PB-ADV dissection
   3  *
   4  * Copyright 2019, Piotr Winiarczyk <wino45@gmail.com>
   5  *
   6  * Wireshark - Network traffic analyzer
   7  * By Gerald Combs <gerald@wireshark.org>
   8  * Copyright 1998 Gerald Combs
   9  *
  10  * SPDX-License-Identifier: GPL-2.0-or-later
  11  *
  12  * Ref: Mesh Profile v1.0
  13  * https://www.bluetooth.com/specifications/mesh-specifications
  14  */
  15
  16 #include "config.h"
  17
  18 #include <epan/packet.h>
  19 #include <epan/prefs.h>
  20 #include <epan/expert.h>
  21 #include <epan/tfs.h>
  22
  23 #include "packet-btmesh.h"
  24
  25 #define BEACON_UNPROVISION 0x00
  26 #define BEACON_SECURE      0x01
  27
  28 void proto_register_btmesh_beacon(void);
  29
  30 static int proto_btmesh_beacon;
  31
  32 static int hf_btmesh_beacon_type;
  33 static int hf_btmesh_beacon_uuid;
  34 static int hf_btmesh_beacon_oob;
  35 static int hf_btmesh_beacon_oob_other;
  36 static int hf_btmesh_beacon_oob_electronic;
  37 static int hf_btmesh_beacon_oob_2d_code;
  38 static int hf_btmesh_beacon_oob_bar_code;
  39 static int hf_btmesh_beacon_oob_nfc;
  40 static int hf_btmesh_beacon_oob_number;
  41 static int hf_btmesh_beacon_oob_string;
  42 static int hf_btmesh_beacon_oob_rfu;
  43 static int hf_btmesh_beacon_oob_on_box;
  44 static int hf_btmesh_beacon_oob_inside_box;
  45 static int hf_btmesh_beacon_oob_on_paper;
  46 static int hf_btmesh_beacon_oob_inside_manual;
  47 static int hf_btmesh_beacon_oob_on_device;
  48 static int hf_btmesh_beacon_uri_hash;
  49 static int hf_btmesh_beacon_flags;
  50 static int hf_btmesh_beacon_flags_key_refresh;
  51 static int hf_btmesh_beacon_flags_iv_update;
  52 static int hf_btmesh_beacon_flags_rfu;
  53 static int hf_btmesh_beacon_network_id;
  54 static int hf_btmesh_beacon_ivindex;
  55 //TODO: check authentication value
  56 static int hf_btmesh_beacon_authentication_value;
  57 static int hf_btmesh_beacon_unknown_data;
  58
  59 static int ett_btmesh_beacon;
  60 static int ett_btmesh_beacon_oob;
  61 static int ett_btmesh_beacon_flags;
  62
  63 static expert_field ei_btmesh_beacon_unknown_beacon_type;
  64 static expert_field ei_btmesh_beacon_unknown_payload;
  65 static expert_field ei_btmesh_beacon_rfu_not_zero;
  66
  67 static const value_string btmesh_beacon_type[] = {
  68     { 0, "Unprovisioned Device Beacon" },
  69     { 1, "Secure Network Beacon" },
  70     { 0, NULL }
  71 };
  72
  73 static const true_false_string flags_key_refresh = {
  74   "Key Refresh in progress",
  75   "Key Refresh not in progress"
  76 };
  77
  78 static const true_false_string flags_iv_update = {
  79   "IV Update active",
  80   "Normal operation"
  81 };
  82
  83 static int
  84 dissect_btmesh_beacon_msg(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data)
  85 {
  86
  87     proto_item *item, *oob_item, *flags_item;
  88     proto_tree *sub_tree, *oob_tree, *flags_tree;
  89     unsigned offset = 0;
  90     unsigned data_size = 0;
  91     btle_mesh_transport_ctx_t *tr_ctx;
  92     btle_mesh_transport_ctx_t dummy_ctx = {E_BTMESH_TR_UNKNOWN, false, 0};
  93     uint16_t rfu_bits16;
  94     uint8_t rfu_bits8;
  95
  96     col_set_str(pinfo->cinfo, COL_PROTOCOL, "BT Mesh Beacon");
  97
  98     if (data == NULL) {
  99         tr_ctx = &dummy_ctx;
 100     } else {
 101         tr_ctx = (btle_mesh_transport_ctx_t *) data;
 102     }
 103
 104     item = proto_tree_add_item(tree, proto_btmesh_beacon, tvb, offset, -1, ENC_NA);
 105     sub_tree = proto_item_add_subtree(item, ett_btmesh_beacon);
 106
 107     uint8_t beacon_type = tvb_get_uint8(tvb, offset);
 108     proto_tree_add_item(sub_tree, hf_btmesh_beacon_type, tvb, offset, 1, ENC_NA);
 109     offset += 1;
 110
 111     col_set_str(pinfo->cinfo, COL_INFO, val_to_str_const(beacon_type, btmesh_beacon_type, "Unknown Beacon Type"));
 112     if (tr_ctx->fragmented) {
 113         switch (tr_ctx->transport) {
 114             case E_BTMESH_TR_PROXY:
 115                 col_append_str(pinfo->cinfo, COL_INFO," (Last Segment)");
 116
 117             break;
 118             default:
 119             //No default is needed since this is an additional information only
 120
 121             break;
 122         }
 123     }
 124
 125     switch(beacon_type) {
 126         case BEACON_UNPROVISION:
 127             proto_tree_add_item(sub_tree, hf_btmesh_beacon_uuid, tvb, offset, 16, ENC_NA);
 128             offset += 16;
 129
 130             oob_item = proto_tree_add_item(sub_tree, hf_btmesh_beacon_oob, tvb, offset, 2, ENC_BIG_ENDIAN);
 131             oob_tree = proto_item_add_subtree(oob_item, ett_btmesh_beacon_oob);
 132
 133             proto_tree_add_item(oob_tree, hf_btmesh_beacon_oob_other, tvb, offset, 2, ENC_NA);
 134             proto_tree_add_item(oob_tree, hf_btmesh_beacon_oob_electronic, tvb, offset, 2, ENC_NA);
 135             proto_tree_add_item(oob_tree, hf_btmesh_beacon_oob_2d_code, tvb, offset, 2, ENC_NA);
 136             proto_tree_add_item(oob_tree, hf_btmesh_beacon_oob_bar_code, tvb, offset, 2, ENC_NA);
 137             proto_tree_add_item(oob_tree, hf_btmesh_beacon_oob_nfc, tvb, offset, 2, ENC_NA);
 138             proto_tree_add_item(oob_tree, hf_btmesh_beacon_oob_number, tvb, offset, 2, ENC_NA);
 139             proto_tree_add_item(oob_tree, hf_btmesh_beacon_oob_string, tvb, offset, 2, ENC_NA);
 140             proto_tree_add_item(oob_tree, hf_btmesh_beacon_oob_rfu, tvb, offset, 2, ENC_NA);
 141             proto_tree_add_item(oob_tree, hf_btmesh_beacon_oob_on_box, tvb, offset, 2, ENC_NA);
 142             proto_tree_add_item(oob_tree, hf_btmesh_beacon_oob_inside_box, tvb, offset, 2, ENC_NA);
 143             proto_tree_add_item(oob_tree, hf_btmesh_beacon_oob_on_paper, tvb, offset, 2, ENC_NA);
 144             proto_tree_add_item(oob_tree, hf_btmesh_beacon_oob_inside_manual, tvb, offset, 2, ENC_NA);
 145             proto_tree_add_item(oob_tree, hf_btmesh_beacon_oob_on_device, tvb, offset, 2, ENC_NA);
 146             rfu_bits16 = (tvb_get_uint16(tvb, offset, ENC_BIG_ENDIAN) & 0x0780) >> 7;
 147             if (rfu_bits16 != 0) {
 148                 //RFU bits should be 0
 149                 proto_tree_add_expert(oob_tree, pinfo, &ei_btmesh_beacon_rfu_not_zero, tvb, offset, -1);
 150             }
 151             offset += 2;
 152
 153             data_size = tvb_reported_length(tvb);
 154             if (data_size == offset + 4 ) {
 155                 proto_tree_add_item(sub_tree, hf_btmesh_beacon_uri_hash, tvb, offset, 4, ENC_NA);
 156                 offset += 4;
 157             }
 158             //Wrong size handled outside switch/case
 159
 160         break;
 161         case BEACON_SECURE:
 162             flags_item = proto_tree_add_item(sub_tree, hf_btmesh_beacon_flags, tvb, offset, 1, ENC_NA);
 163             flags_tree = proto_item_add_subtree(flags_item, ett_btmesh_beacon_flags);
 164             proto_tree_add_item(flags_tree, hf_btmesh_beacon_flags_key_refresh, tvb, offset, 1, ENC_NA);
 165             proto_tree_add_item(flags_tree, hf_btmesh_beacon_flags_iv_update, tvb, offset, 1, ENC_NA);
 166             proto_tree_add_item(flags_tree, hf_btmesh_beacon_flags_rfu, tvb, offset, 1, ENC_NA);
 167             rfu_bits8 = tvb_get_uint8(tvb, offset) >> 2;
 168             if (rfu_bits8 != 0) {
 169                 //RFU bits should be 0
 170                 proto_tree_add_expert(flags_tree, pinfo, &ei_btmesh_beacon_rfu_not_zero, tvb, offset, -1);
 171             }
 172             offset += 1;
 173             proto_tree_add_item(sub_tree, hf_btmesh_beacon_network_id, tvb, offset, 8, ENC_NA);
 174             offset += 8;
 175             proto_tree_add_item(sub_tree, hf_btmesh_beacon_ivindex, tvb, offset, 4, ENC_NA);
 176             offset += 4;
 177             proto_tree_add_item(sub_tree, hf_btmesh_beacon_authentication_value, tvb, offset, 8, ENC_NA);
 178             offset += 8;
 179         break;
 180         default:
 181             //Unknown mesh beacon type, display data and flag it
 182             proto_tree_add_item(sub_tree, hf_btmesh_beacon_unknown_data, tvb, offset, -1, ENC_NA);
 183             proto_tree_add_expert(sub_tree, pinfo, &ei_btmesh_beacon_unknown_beacon_type, tvb, offset, -1);
 184             offset += tvb_captured_length_remaining(tvb, offset);
 185         break;
 186     }
 187     //There is still some data but all data should be already disssected
 188     if (tvb_captured_length_remaining(tvb, offset) != 0) {
 189         proto_tree_add_expert(sub_tree, pinfo, &ei_btmesh_beacon_unknown_payload, tvb, offset, -1);
 190     }
 191
 192     return tvb_reported_length(tvb);
 193 }
 194
 195 void
 196 proto_register_btmesh_beacon(void)
 197 {
 198     static hf_register_info hf[] = {
 199         { &hf_btmesh_beacon_type,
 200             { "Type", "beacon.type",
 201                 FT_UINT8, BASE_DEC, VALS(btmesh_beacon_type), 0x0,
 202                 NULL, HFILL }
 203         },
 204         { &hf_btmesh_beacon_uuid,
 205             { "Device UUID", "beacon.uuid",
 206                 FT_GUID, BASE_NONE, NULL, 0x0,
 207                 NULL, HFILL }
 208         },
 209         { &hf_btmesh_beacon_oob,
 210             { "OOB Information", "beacon.oob",
 211                 FT_UINT16, BASE_HEX, NULL, 0x0,
 212                 NULL, HFILL }
 213         },
 214         { &hf_btmesh_beacon_oob_other,
 215             { "Other", "beacon.oob.other",
 216                 FT_BOOLEAN, 16, TFS(&tfs_available_not_available), 0x0001,
 217                 NULL, HFILL }
 218         },
 219        { &hf_btmesh_beacon_oob_electronic,
 220             { "Electronic / URI", "beacon.oob.electronic",
 221                 FT_BOOLEAN, 16, TFS(&tfs_available_not_available), 0x0002,
 222                 NULL, HFILL }
 223         },
 224        { &hf_btmesh_beacon_oob_2d_code,
 225             { "2D machine-readable code", "beacon.oob.2d_code",
 226                 FT_BOOLEAN, 16, TFS(&tfs_available_not_available), 0x0004,
 227                 NULL, HFILL }
 228         },
 229        { &hf_btmesh_beacon_oob_bar_code,
 230             { "Bar code", "beacon.oob.bar_code",
 231                 FT_BOOLEAN, 16, TFS(&tfs_available_not_available), 0x0008,
 232                 NULL, HFILL }
 233         },
 234        { &hf_btmesh_beacon_oob_nfc,
 235             { "Near Field Communication (NFC)", "beacon.oob.nfc",
 236                 FT_BOOLEAN, 16, TFS(&tfs_available_not_available), 0x0010,
 237                 NULL, HFILL }
 238         },
 239        { &hf_btmesh_beacon_oob_number,
 240             { "Number", "beacon.oob.number",
 241                 FT_BOOLEAN, 16, TFS(&tfs_available_not_available), 0x0020,
 242                 NULL, HFILL }
 243         },
 244        { &hf_btmesh_beacon_oob_string,
 245             { "String", "beacon.oob.string",
 246                 FT_BOOLEAN, 16, TFS(&tfs_available_not_available), 0x0040,
 247                 NULL, HFILL }
 248         },
 249        { &hf_btmesh_beacon_oob_rfu,
 250             { "Reserved for Future Use", "beacon.oob.rfu",
 251                 FT_UINT16, BASE_DEC, NULL, 0x0780,
 252                 NULL, HFILL }
 253         },
 254        { &hf_btmesh_beacon_oob_on_box,
 255             { "On box", "beacon.oob.on_box",
 256                 FT_BOOLEAN, 16, TFS(&tfs_available_not_available), 0x0800,
 257                 NULL, HFILL }
 258         },
 259        { &hf_btmesh_beacon_oob_inside_box,
 260             { "Inside box", "beacon.oob.inside_box",
 261                 FT_BOOLEAN, 16, TFS(&tfs_available_not_available), 0x1000,
 262                 NULL, HFILL }
 263         },
 264        { &hf_btmesh_beacon_oob_on_paper,
 265             { "On piece of paper", "beacon.oob.on_paper",
 266                 FT_BOOLEAN, 16, TFS(&tfs_available_not_available), 0x2000,
 267                 NULL, HFILL }
 268         },
 269        { &hf_btmesh_beacon_oob_inside_manual,
 270             { "Inside manual", "beacon.oob.inside_manual",
 271                 FT_BOOLEAN, 16, TFS(&tfs_available_not_available), 0x4000,
 272                 NULL, HFILL }
 273         },
 274        { &hf_btmesh_beacon_oob_on_device,
 275             { "On device", "beacon.oob.on_device",
 276                 FT_BOOLEAN, 16, TFS(&tfs_available_not_available), 0x8000,
 277                 NULL, HFILL }
 278         },
 279         { &hf_btmesh_beacon_uri_hash,
 280             { "URI Hash", "beacon.uri_hash",
 281                 FT_BYTES, BASE_NONE, NULL, 0x0,
 282                 NULL, HFILL }
 283         },
 284         { &hf_btmesh_beacon_flags,
 285             { "Flags", "beacon.flags",
 286                 FT_UINT8, BASE_HEX, NULL, 0x0,
 287                 NULL, HFILL }
 288         },
 289        { &hf_btmesh_beacon_flags_key_refresh,
 290             { "Key Refresh Flag", "beacon.flags.key_refresh",
 291                 FT_BOOLEAN, 8, TFS(&flags_key_refresh), 0x01,
 292                 NULL, HFILL }
 293         },
 294        { &hf_btmesh_beacon_flags_iv_update,
 295             { "IV Update Flag", "beacon.flags.iv_update",
 296                 FT_BOOLEAN, 8, TFS(&flags_iv_update), 0x02,
 297                 NULL, HFILL }
 298         },
 299        { &hf_btmesh_beacon_flags_rfu,
 300             { "Reserved for Future Use", "beacon.flags.rfu",
 301                 FT_UINT8, BASE_DEC, NULL, 0xFC,
 302                 NULL, HFILL }
 303         },
 304        { &hf_btmesh_beacon_network_id,
 305             { "Network ID", "beacon.network_id",
 306                 FT_BYTES, BASE_NONE, NULL, 0x0,
 307                 NULL, HFILL }
 308         },
 309         { &hf_btmesh_beacon_ivindex,
 310             { "IV Index", "beacon.ivindex",
 311                 FT_UINT32, BASE_DEC, NULL, 0x0,
 312                 NULL, HFILL }
 313         },
 314         { &hf_btmesh_beacon_authentication_value,
 315             { "Authentication Value", "beacon.authentication_value",
 316                 FT_BYTES, BASE_NONE, NULL, 0x0,
 317                 NULL, HFILL }
 318         },
 319         { &hf_btmesh_beacon_unknown_data,
 320             { "Unknown Data", "beacon.unknown_data",
 321                 FT_BYTES, BASE_NONE, NULL, 0x0,
 322                 NULL, HFILL }
 323         },
 324     };
 325
 326     static int *ett[] = {
 327         &ett_btmesh_beacon,
 328         &ett_btmesh_beacon_oob,
 329         &ett_btmesh_beacon_flags,
 330     };
 331
 332     static ei_register_info ei[] = {
 333         { &ei_btmesh_beacon_unknown_beacon_type,{ "beacon.unknown_beacon_type", PI_PROTOCOL, PI_ERROR, "Unknown Beacon Type", EXPFILL } },
 334         { &ei_btmesh_beacon_unknown_payload,{ "beacon.unknown_payload", PI_PROTOCOL, PI_ERROR, "Unknown Payload", EXPFILL } },
 335         { &ei_btmesh_beacon_rfu_not_zero,{ "beacon.rfu_not_zero", PI_PROTOCOL, PI_WARN, "Reserved for Future Use value not equal to 0", EXPFILL } },
 336     };
 337
 338     expert_module_t* expert_btmesh_beacon;
 339
 340     proto_btmesh_beacon = proto_register_protocol("Bluetooth Mesh Beacon", "BT Mesh beacon", "beacon");
 341
 342     proto_register_field_array(proto_btmesh_beacon, hf, array_length(hf));
 343     proto_register_subtree_array(ett, array_length(ett));
 344
 345     expert_btmesh_beacon = expert_register_protocol(proto_btmesh_beacon);
 346     expert_register_field_array(expert_btmesh_beacon, ei, array_length(ei));
 347
 348     prefs_register_protocol_subtree("Bluetooth", proto_btmesh_beacon, NULL);
 349     register_dissector("btmesh.beacon", dissect_btmesh_beacon_msg, proto_btmesh_beacon);
 350 }
 351
 352 /*
 353  * Editor modelines
 354  *
 355  * Local Variables:
 356  * c-basic-offset: 4
 357  * tab-width: 8
 358  * indent-tabs-mode: nil
 359  * End:
 360  *
 361  * ex: set shiftwidth=4 tabstop=8 expandtab:
 362  * :indentSize=4:tabSize=8:noTabs=true:
 363  */