path: root/epan/dissectors/packet-btmcap.c

/* packet-btmcap.c
 * Routines for Bluetooth MCAP dissection
 * https://www.bluetooth.org/Technical/Specifications/adopted.htm
 *
 * Copyright 2013, Michal Labedzki for Tieto Corporation
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

#include "config.h"

#include <epan/packet.h>
#include <epan/prefs.h>
#include <epan/expert.h>
#include <epan/unit_strings.h>

static int proto_btmcap;

static int hf_btmcap_op_code;
static int hf_btmcap_response_code;
static int hf_btmcap_mdl_id;
static int hf_btmcap_mdep_id;
static int hf_btmcap_response_parameters;
static int hf_btmcap_configuration;
static int hf_btmcap_timestamp_required_accuracy;
static int hf_btmcap_timestamp_update_information;
static int hf_btmcap_bluetooth_clock_sync_time;
static int hf_btmcap_timestamp_sync_time;
static int hf_btmcap_timestamp_sample_accuracy;
static int hf_btmcap_bluetooth_clock_access_resolution;
static int hf_btmcap_sync_lead_time;
static int hf_btmcap_timestamp_native_resolution;
static int hf_btmcap_timestamp_native_accuracy;
static int hf_btmcap_data;

static int ett_btmcap;

static expert_field ei_btmcap_mdl_id_ffff;
static expert_field ei_btmcap_response_parameters_bad;
static expert_field ei_btmcap_unexpected_data;

static dissector_handle_t btmcap_handle;

static const value_string op_code_vals[] = {
    { 0x00,   "ERROR_RSP" },
    { 0x01,   "MD_CREATE_MDL_REQ" },
    { 0x02,   "MD_CREATE_MDL_RSP" },
    { 0x03,   "MD_RECONNECT_MDL_REQ" },
    { 0x04,   "MD_RECONNECT_MDL_RSP" },
    { 0x05,   "MD_ABORT_MDL_REQ" },
    { 0x06,   "MD_ABORT_MDL_RSP" },
    { 0x07,   "MD_DELETE_MDL_REQ" },
    { 0x08,   "MD_DELETE_MDL_RSP" },
    { 0x11,   "MD_SYNC_CAP_REQ" },
    { 0x12,   "MD_SYNC_CAP_RSP" },
    { 0x13,   "MD_SYNC_SET_REQ" },
    { 0x14,   "MD_SYNC_SET_RSP" },
    { 0x15,   "MD_SYNC_INFO_IND" },
    { 0x16,   "Reserved as pseudoresponse" },
    { 0, NULL }
};

static const value_string response_code_vals[] = {
    { 0x00,   "Success" },
    { 0x01,   "Invalid Op Code" },
    { 0x02,   "Invalid Parameter Value" },
    { 0x03,   "Invalid MDEP" },
    { 0x04,   "MDEP Busy" },
    { 0x05,   "Invalid MDL" },
    { 0x06,   "MDL Busy" },
    { 0x07,   "Invalid Operation" },
    { 0x08,   "Resource Unavailable" },
    { 0x09,   "Unspecified Error" },
    { 0x0A,   "Request Not Supported" },
    { 0x0B,   "Configuration Rejected" },
    { 0, NULL }
};

static const unit_name_string units_ppm = { " ppm", NULL };

void proto_register_btmcap(void);
void proto_reg_handoff_btmcap(void);

static int
dissect_btmcap(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void *data _U_)
{
    proto_item *main_item;
    proto_tree *main_tree;
    proto_item *pitem;
    int         offset = 0;
    uint32_t    op_code;
    uint32_t    response_code;
    uint32_t    mdl_id;
    uint32_t    mdep_id;
    uint32_t    bluetooth_clock_sync_time;
    uint64_t    timestamp_sync_time;

    main_item = proto_tree_add_item(tree, proto_btmcap, tvb, offset, tvb_captured_length(tvb), ENC_NA);
    main_tree = proto_item_add_subtree(main_item, ett_btmcap);

    col_set_str(pinfo->cinfo, COL_PROTOCOL, "MCAP");

    switch (pinfo->p2p_dir) {
        case P2P_DIR_SENT:
            col_set_str(pinfo->cinfo, COL_INFO, "Sent ");
            break;
        case P2P_DIR_RECV:
            col_set_str(pinfo->cinfo, COL_INFO, "Rcvd ");
            break;
        default:
            col_set_str(pinfo->cinfo, COL_INFO, "UnknownDirection ");
            break;
    }

    pitem = proto_tree_add_item(main_tree, hf_btmcap_op_code, tvb, offset, 1, ENC_BIG_ENDIAN);
    op_code = tvb_get_uint8(tvb, offset);
    offset += 1;

    col_append_str(pinfo->cinfo, COL_INFO, val_to_str_const(op_code, op_code_vals, "Unknown Op Code"));
    if (op_code >= 0x11 && op_code <= 0x20) {
        proto_item_append_text(pitem, " (Clock Sync)");
        col_append_str(pinfo->cinfo, COL_INFO, " (Clock Sync)");
    } else {
        proto_item_append_text(pitem, " (Standard)");
        col_append_str(pinfo->cinfo, COL_INFO, " (Standard)");
    }

    if (op_code & 0x01) {
        /* isRequest */
        switch(op_code) {
            case 0x01: /* MD_CREATE_MDL_REQ */
            case 0x03: /* MD_RECONNECT_MDL_REQ */
            case 0x05: /* MD_ABORT_MDL_REQ */
            case 0x07: /* MD_DELETE_MDL_REQ */
                pitem = proto_tree_add_item(main_tree, hf_btmcap_mdl_id, tvb, offset, 2, ENC_BIG_ENDIAN);
                mdl_id = tvb_get_ntohs(tvb, offset);
                offset += 2;

                col_append_fstr(pinfo->cinfo, COL_INFO, " - MDL ID: %u", mdl_id);
                if (mdl_id == 0xFFFF) {
                    proto_item_append_text(pitem, " (Indicates all MDLs)");
                    col_append_str(pinfo->cinfo, COL_INFO, " (Indicates all MDLs)");
                } else if (mdl_id >= 0x0001 && mdl_id <= 0xFEFF) {
                    proto_item_append_text(pitem, " (Dynamic Range)");
                    col_append_str(pinfo->cinfo, COL_INFO, " (Dynamic Range)");
                } else if (mdl_id == 0x0000) {
                    proto_item_append_text(pitem, " (Reserved)");
                    col_append_str(pinfo->cinfo, COL_INFO, " (Reserved)");
                }

                if (op_code != 0x07 && mdl_id == 0xFFFF) {
                    expert_add_info(pinfo, pitem, &ei_btmcap_mdl_id_ffff);
                    }

                if (op_code == 0x01) {
                    /* only MD_CREATE_MDL_REQ */
                    pitem = proto_tree_add_item(main_tree, hf_btmcap_mdep_id, tvb, offset, 1, ENC_BIG_ENDIAN);
                    mdep_id = tvb_get_uint8(tvb, offset);
                    offset += 1;

                    if (mdep_id <= 0x7F) {
                        proto_item_append_text(pitem, " (Available for use)");
                    } else {
                        proto_item_append_text(pitem, " (Reserved)");
                    }

                    proto_tree_add_item(main_tree, hf_btmcap_configuration, tvb, offset, 1, ENC_BIG_ENDIAN);
                    offset += 1;
                }
                break;
            case 0x11: /* MD_SYNC_CAP_REQ */
                proto_tree_add_item(main_tree, hf_btmcap_timestamp_required_accuracy, tvb, offset, 2, ENC_BIG_ENDIAN);
                offset += 2;
                break;
            case 0x13: /* MD_SYNC_SET_REQ */
                proto_tree_add_item(main_tree, hf_btmcap_timestamp_update_information, tvb, offset, 1, ENC_BIG_ENDIAN);
                offset += 1;

                pitem = proto_tree_add_item(main_tree, hf_btmcap_bluetooth_clock_sync_time, tvb, offset, 4, ENC_BIG_ENDIAN);
                bluetooth_clock_sync_time = tvb_get_ntohl(tvb, offset);
                if (bluetooth_clock_sync_time == 0xFFFFFFFF)
                    proto_item_append_text(pitem, " (Instant Synchronization)");
                else
                    proto_item_append_text(pitem, " (Baseband Half-Slot Instant)");
                offset += 4;

                pitem = proto_tree_add_item(main_tree, hf_btmcap_timestamp_sync_time, tvb, offset, 8, ENC_BIG_ENDIAN);
                timestamp_sync_time = tvb_get_ntoh64(tvb, offset);
                if (timestamp_sync_time == UINT64_C(0xFFFFFFFFFFFFFFFF))
                    proto_item_append_text(pitem, " (No Time Synchronization)");
                else
                    proto_item_append_text(pitem, " (Time-Stamp Clock Instant)");
                offset += 8;
                break;
            case 0x15: /* MD_SYNC_INFO_IND */
                pitem = proto_tree_add_item(main_tree, hf_btmcap_bluetooth_clock_sync_time, tvb, offset, 4, ENC_BIG_ENDIAN);
                proto_item_append_text(pitem, " (Baseband Half-Slot Instant)");
                offset += 4;

                pitem = proto_tree_add_item(main_tree, hf_btmcap_timestamp_sync_time, tvb, offset, 8, ENC_BIG_ENDIAN);
                proto_item_append_text(pitem, " (Time-Stamp Clock Instant)");
                offset += 8;

                proto_tree_add_item(main_tree, hf_btmcap_timestamp_sample_accuracy, tvb, offset, 2, ENC_BIG_ENDIAN);
                offset += 2;
                break;
        }
    } else {
        /* isResponse */

        proto_tree_add_item(main_tree, hf_btmcap_response_code, tvb, offset, 1, ENC_BIG_ENDIAN);
        response_code = tvb_get_uint8(tvb, offset);
        offset += 1;

        col_append_fstr(pinfo->cinfo, COL_INFO, " - %s", val_to_str_const(response_code, response_code_vals, "Unknown ResponseCode"));

        if (op_code >= 0x11 && op_code <= 0x20) {
            /* Clock Sync */
            switch(op_code) {
                case 0x12: /* MD_SYNC_CAP_RSP */
                    pitem = proto_tree_add_item(main_tree, hf_btmcap_bluetooth_clock_access_resolution, tvb, offset, 1, ENC_BIG_ENDIAN);
                    proto_item_append_text(pitem, " (Baseband half-slots)");
                    offset += 1;

                    proto_tree_add_item(main_tree, hf_btmcap_sync_lead_time, tvb, offset, 2, ENC_BIG_ENDIAN);
                    offset += 2;

                    proto_tree_add_item(main_tree, hf_btmcap_timestamp_native_resolution, tvb, offset, 2, ENC_BIG_ENDIAN);
                    offset += 2;

                    proto_tree_add_item(main_tree, hf_btmcap_timestamp_native_accuracy, tvb, offset, 2, ENC_BIG_ENDIAN);
                    offset += 2;
                    break;
                case 0x14: /* MD_SYNC_SET_RSP */
                    pitem = proto_tree_add_item(main_tree, hf_btmcap_bluetooth_clock_sync_time, tvb, offset, 4, ENC_BIG_ENDIAN);
                    bluetooth_clock_sync_time = tvb_get_ntohl(tvb, offset);
                    if (bluetooth_clock_sync_time == 0xFFFFFFFF)
                        proto_item_append_text(pitem, " (Instant Synchronization)");
                    else
                        proto_item_append_text(pitem, " (Baseband Half-Slot Instant)");
                    offset += 4;

                    pitem = proto_tree_add_item(main_tree, hf_btmcap_timestamp_sync_time, tvb, offset, 8, ENC_BIG_ENDIAN);
                    timestamp_sync_time = tvb_get_ntoh64(tvb, offset);
                    if (timestamp_sync_time == UINT64_C(0xFFFFFFFFFFFFFFFF))
                        proto_item_append_text(pitem, " (No Time Synchronization)");
                    else
                        proto_item_append_text(pitem, " (Time-Stamp Clock Instant)");
                    offset += 8;

                    proto_tree_add_item(main_tree, hf_btmcap_timestamp_sample_accuracy, tvb, offset, 2, ENC_BIG_ENDIAN);
                    offset += 2;
                    break;
            }
        } else {
            /* Standard Op Code */
            pitem = proto_tree_add_item(main_tree, hf_btmcap_mdl_id, tvb, offset, 2, ENC_BIG_ENDIAN);
            mdl_id = tvb_get_ntohs(tvb, offset);
            offset += 2;

            col_append_fstr(pinfo->cinfo, COL_INFO, " - %u", mdl_id);
            if (mdl_id == 0xFFFF) {
                proto_item_append_text(pitem, " (Indicates all MDLs)");
                col_append_str(pinfo->cinfo, COL_INFO, " (Indicates all MDLs)");
            } else if (mdl_id >= 0x0001 && mdl_id <= 0xFEFF) {
                proto_item_append_text(pitem, " (Dynamic Range)");
                col_append_str(pinfo->cinfo, COL_INFO, " (Dynamic Range)");
            } else if (mdl_id == 0x0000) {
                proto_item_append_text(pitem, " (Reserved)");
                col_append_str(pinfo->cinfo, COL_INFO, " (Reserved)");
            }

            if ((op_code == 0x03 || op_code == 0x05 || op_code == 0x07) && tvb_reported_length_remaining(tvb, offset)) {
                    expert_add_info_format(pinfo, pitem, &ei_btmcap_response_parameters_bad,
                            "The Response Parameters for MD_RECONNECT_MDL_RSP shall have length zero.");
            } else if (tvb_reported_length_remaining(tvb, offset)) {
                pitem = proto_tree_add_item(main_tree, hf_btmcap_response_parameters, tvb, offset, tvb_reported_length_remaining(tvb, offset), ENC_NA);
                if (response_code != 0x00) {
                    expert_add_info_format(pinfo, pitem, &ei_btmcap_response_parameters_bad,
                            "When the Response Code is not Success, the Response Parameters shall have length zero.");
                }
                offset += tvb_reported_length_remaining(tvb, offset);
            }
        }
    }

    if (tvb_reported_length_remaining(tvb, offset)) {
        pitem = proto_tree_add_item(main_tree, hf_btmcap_data, tvb, offset, tvb_reported_length_remaining(tvb, offset), ENC_NA);
        expert_add_info(pinfo, pitem, &ei_btmcap_unexpected_data);
        offset = tvb_reported_length(tvb);
    }

    return offset;
}


void
proto_register_btmcap(void)
{
    module_t *module;
    expert_module_t *expert_btmcap;

    static hf_register_info hf[] = {
        { &hf_btmcap_op_code,
            { "Op Code",                         "btmcap.op_code",
            FT_UINT8, BASE_HEX, VALS(op_code_vals), 0x0,
            NULL, HFILL }
        },
        { &hf_btmcap_response_code,
            { "Response Code",                   "btmcap.response_code",
            FT_UINT8, BASE_HEX, VALS(response_code_vals), 0x0,
            NULL, HFILL }
        },
        { &hf_btmcap_mdl_id,
            { "MDL ID",                          "btmcap.mdl_id",
            FT_UINT16, BASE_HEX, NULL, 0x0,
            NULL, HFILL }
        },
        { &hf_btmcap_mdep_id,
            { "MDEP ID",                         "btmcap.mdep_id",
            FT_UINT8, BASE_HEX, NULL, 0x0,
            NULL, HFILL }
        },
        { &hf_btmcap_configuration,
            { "Configuration",                   "btmcap.configuration",
            FT_UINT8, BASE_HEX, NULL, 0x0,
            NULL, HFILL }
        },
        { &hf_btmcap_timestamp_required_accuracy,
            { "Timestamp Required Accuracy",     "btmcap.timestamp_required_accuracy",
            FT_UINT16, BASE_DEC|BASE_UNIT_STRING, UNS(&units_ppm), 0x00,
            NULL, HFILL }
        },
        { &hf_btmcap_timestamp_update_information,
            { "Timestamp Update Information",    "btmcap.timestamp_update_information",
            FT_UINT8, BASE_DEC, NULL, 0x00,
            NULL, HFILL }
        },
        { &hf_btmcap_bluetooth_clock_sync_time,
            { "Bluetooth Clock Sync Time",       "btmcap.bluetooth_clock_sync_time",
            FT_UINT32, BASE_DEC, NULL, 0x00,
            NULL, HFILL }
        },
        { &hf_btmcap_timestamp_sync_time,
            { "Timestamp Sync Time",             "btmcap.timestamp_sync_time",
            FT_UINT64, BASE_DEC, NULL, 0x00,
            NULL, HFILL }
        },
        { &hf_btmcap_timestamp_sample_accuracy,
            { "Timestamp Sample Accuracy",       "btmcap.timestamp_sample_accuracy",
            FT_UINT16, BASE_DEC|BASE_UNIT_STRING, UNS(&units_microseconds), 0x00,
            NULL, HFILL }
        },
        { &hf_btmcap_bluetooth_clock_access_resolution,
            { "Bluetooth Clock Access Resolution","btmcap.bluetooth_clock_access_resolution",
            FT_UINT8, BASE_DEC, NULL, 0x00,
            NULL, HFILL }
        },
        { &hf_btmcap_sync_lead_time,
            { "Sync Lead Time",                  "btmcap.sync_lead_time",
            FT_UINT16, BASE_DEC|BASE_UNIT_STRING, UNS(&units_milliseconds), 0x00,
            NULL, HFILL }
        },
        { &hf_btmcap_timestamp_native_resolution,
            { "Timestamp Native Resolution",     "btmcap.timestamp_native_resolution",
            FT_UINT16, BASE_DEC|BASE_UNIT_STRING, UNS(&units_microseconds), 0x00,
            NULL, HFILL }
        },
        { &hf_btmcap_timestamp_native_accuracy,
            { "Timestamp Native Accuracy",       "btmcap.timestamp_native_accuracy",
            FT_UINT16, BASE_DEC|BASE_UNIT_STRING, UNS(&units_ppm), 0x00,
            NULL, HFILL }
        },
        { &hf_btmcap_response_parameters,
            { "Response Parameters",             "btmcap.response_parameters",
            FT_BYTES, BASE_NONE, NULL, 0x00,
            NULL, HFILL }
        },

        { &hf_btmcap_data,
            { "Data",                            "btmcap.data",
            FT_NONE, BASE_NONE, NULL, 0x00,
            NULL, HFILL }
        },

    };

    static int *ett[] = {
        &ett_btmcap
    };

    static ei_register_info ei[] = {
        { &ei_btmcap_mdl_id_ffff, { "btmcap.mdl_id.ffff", PI_PROTOCOL, PI_WARN, "The value 0xFFFF is not a valid MDL ID for this request and shall not be used.", EXPFILL }},
        { &ei_btmcap_response_parameters_bad, { "btmcap.response_parameters.bad", PI_PROTOCOL, PI_WARN, "Response parameters bad", EXPFILL }},
        { &ei_btmcap_unexpected_data, { "btmcap.unexpected_data", PI_PROTOCOL, PI_WARN, "Unexpected data", EXPFILL }},
    };

    proto_btmcap = proto_register_protocol("Bluetooth MCAP Protocol", "BT MCAP", "btmcap");
    btmcap_handle = register_dissector("btmcap", dissect_btmcap, proto_btmcap);

    proto_register_field_array(proto_btmcap, hf, array_length(hf));
    proto_register_subtree_array(ett, array_length(ett));
    expert_btmcap = expert_register_protocol(proto_btmcap);
    expert_register_field_array(expert_btmcap, ei, array_length(ei));

    module = prefs_register_protocol_subtree("Bluetooth", proto_btmcap, NULL);
    prefs_register_static_text_preference(module, "mcap.version",
            "Bluetooth Protocol MCAP version: 1.0",
            "Version of protocol supported by this dissector.");
}


void
proto_reg_handoff_btmcap(void)
{
    dissector_add_string("bluetooth.uuid", "1e", btmcap_handle);
    dissector_add_string("bluetooth.uuid", "1f", btmcap_handle);
    dissector_add_string("bluetooth.uuid", "1400", btmcap_handle);
    dissector_add_string("bluetooth.uuid", "1401", btmcap_handle);
    dissector_add_string("bluetooth.uuid", "1402", btmcap_handle);

    /* dynamic PSM */
    dissector_add_for_decode_as("btl2cap.psm", btmcap_handle);
    dissector_add_for_decode_as("btl2cap.cid", btmcap_handle);
}

/*
 * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 *
 * Local variables:
 * c-basic-offset: 4
 * tab-width: 8
 * indent-tabs-mode: nil
 * End:
 *
 * vi: set shiftwidth=4 tabstop=8 expandtab:
 * :indentSize=4:tabSize=8:noTabs=true:
 */