pulseaudio/src/modules/bluetooth/bluez5-util.c

/***
  This file is part of PulseAudio.

  Copyright 2008-2013 João Paulo Rechi Vita

  PulseAudio is free software; you can redistribute it and/or modify
  it under the terms of the GNU Lesser General Public License as
  published by the Free Software Foundation; either version 2.1 of the
  License, or (at your option) any later version.

  PulseAudio is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with PulseAudio; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  USA.
***/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <pulse/xmalloc.h>

#include <pulsecore/core.h>
#include <pulsecore/core-util.h>
#include <pulsecore/dbus-shared.h>
#include <pulsecore/log.h>
#include <pulsecore/macro.h>
#include <pulsecore/refcnt.h>
#include <pulsecore/shared.h>

#include "a2dp-codecs.h"

#include "bluez5-util.h"

#define BLUEZ_SERVICE "org.bluez"
#define BLUEZ_MEDIA_ENDPOINT_INTERFACE BLUEZ_SERVICE ".MediaEndpoint1"
#define BLUEZ_MEDIA_TRANSPORT_INTERFACE BLUEZ_SERVICE ".MediaTransport1"

#define A2DP_SOURCE_ENDPOINT "/MediaEndpoint/A2DPSource"
#define A2DP_SINK_ENDPOINT "/MediaEndpoint/A2DPSink"

#define ENDPOINT_INTROSPECT_XML                                         \
    DBUS_INTROSPECT_1_0_XML_DOCTYPE_DECL_NODE                           \
    "<node>"                                                            \
    " <interface name=\"" BLUEZ_MEDIA_ENDPOINT_INTERFACE "\">"          \
    "  <method name=\"SetConfiguration\">"                              \
    "   <arg name=\"transport\" direction=\"in\" type=\"o\"/>"          \
    "   <arg name=\"properties\" direction=\"in\" type=\"ay\"/>"        \
    "  </method>"                                                       \
    "  <method name=\"SelectConfiguration\">"                           \
    "   <arg name=\"capabilities\" direction=\"in\" type=\"ay\"/>"      \
    "   <arg name=\"configuration\" direction=\"out\" type=\"ay\"/>"    \
    "  </method>"                                                       \
    "  <method name=\"ClearConfiguration\">"                            \
    "   <arg name=\"transport\" direction=\"in\" type=\"o\"/>"          \
    "  </method>"                                                       \
    "  <method name=\"Release\">"                                       \
    "  </method>"                                                       \
    " </interface>"                                                     \
    " <interface name=\"org.freedesktop.DBus.Introspectable\">"         \
    "  <method name=\"Introspect\">"                                    \
    "   <arg name=\"data\" type=\"s\" direction=\"out\"/>"              \
    "  </method>"                                                       \
    " </interface>"                                                     \
    "</node>"

struct pa_bluetooth_discovery {
    PA_REFCNT_DECLARE;

    pa_core *core;
    pa_dbus_connection *connection;
    bool filter_added;
    bool matches_added;
    bool objects_listed;
    pa_hook hooks[PA_BLUETOOTH_HOOK_MAX];
    pa_hashmap *adapters;
    pa_hashmap *devices;
    pa_hashmap *transports;

    PA_LLIST_HEAD(pa_dbus_pending, pending);
};

static pa_dbus_pending* send_and_add_to_pending(pa_bluetooth_discovery *y, DBusMessage *m,
                                                                  DBusPendingCallNotifyFunction func, void *call_data) {
    pa_dbus_pending *p;
    DBusPendingCall *call;

    pa_assert(y);
    pa_assert(m);

    pa_assert_se(dbus_connection_send_with_reply(pa_dbus_connection_get(y->connection), m, &call, -1));

    p = pa_dbus_pending_new(pa_dbus_connection_get(y->connection), m, call, y, call_data);
    PA_LLIST_PREPEND(pa_dbus_pending, y->pending, p);
    dbus_pending_call_set_notify(call, func, p, NULL);

    return p;
}

pa_bluetooth_transport *pa_bluetooth_transport_new(pa_bluetooth_device *d, const char *owner, const char *path,
                                                   pa_bluetooth_profile_t p, const uint8_t *config, size_t size) {
    pa_bluetooth_transport *t;

    t = pa_xnew0(pa_bluetooth_transport, 1);
    t->device = d;
    t->owner = pa_xstrdup(owner);
    t->path = pa_xstrdup(path);
    t->profile = p;
    t->config_size = size;

    if (size > 0) {
        t->config = pa_xnew(uint8_t, size);
        memcpy(t->config, config, size);
    }

    pa_assert_se(pa_hashmap_put(d->discovery->transports, t->path, t) >= 0);

    return t;
}

static const char *transport_state_to_string(pa_bluetooth_transport_state_t state) {
    switch(state) {
        case PA_BLUETOOTH_TRANSPORT_STATE_DISCONNECTED:
            return "disconnected";
        case PA_BLUETOOTH_TRANSPORT_STATE_IDLE:
            return "idle";
        case PA_BLUETOOTH_TRANSPORT_STATE_PLAYING:
            return "playing";
    }

    return "invalid";
}

static void transport_state_changed(pa_bluetooth_transport *t, pa_bluetooth_transport_state_t state) {
    bool old_any_connected;

    pa_assert(t);

    if (t->state == state)
        return;

    old_any_connected = pa_bluetooth_device_any_transport_connected(t->device);

    pa_log_debug("Transport %s state changed from %s to %s",
                 t->path, transport_state_to_string(t->state), transport_state_to_string(state));

    t->state = state;
    if (state == PA_BLUETOOTH_TRANSPORT_STATE_DISCONNECTED)
        t->device->transports[t->profile] = NULL;

    pa_hook_fire(&t->device->discovery->hooks[PA_BLUETOOTH_HOOK_TRANSPORT_STATE_CHANGED], t);

    if (old_any_connected != pa_bluetooth_device_any_transport_connected(t->device))
        pa_hook_fire(&t->device->discovery->hooks[PA_BLUETOOTH_HOOK_DEVICE_CONNECTION_CHANGED], t->device);
}

void pa_bluetooth_transport_put(pa_bluetooth_transport *t) {
    transport_state_changed(t, PA_BLUETOOTH_TRANSPORT_STATE_IDLE);
}

void pa_bluetooth_transport_free(pa_bluetooth_transport *t) {
    pa_assert(t);

    pa_hashmap_remove(t->device->discovery->transports, t->path);
    pa_xfree(t->owner);
    pa_xfree(t->path);
    pa_xfree(t->config);
    pa_xfree(t);
}

static int bluez5_transport_acquire_cb(pa_bluetooth_transport *t, bool optional, size_t *imtu, size_t *omtu) {
    DBusMessage *m, *r;
    DBusError err;
    int ret;
    uint16_t i, o;
    const char *method = optional ? "TryAcquire" : "Acquire";

    pa_assert(t);
    pa_assert(t->device);
    pa_assert(t->device->discovery);

    pa_assert_se(m = dbus_message_new_method_call(t->owner, t->path, BLUEZ_MEDIA_TRANSPORT_INTERFACE, method));

    dbus_error_init(&err);

    r = dbus_connection_send_with_reply_and_block(pa_dbus_connection_get(t->device->discovery->connection), m, -1, &err);
    if (!r) {
        if (optional && pa_streq(err.name, "org.bluez.Error.NotAvailable"))
            pa_log_info("Failed optional acquire of unavailable transport %s", t->path);
        else
            pa_log_error("Transport %s() failed for transport %s (%s)", method, t->path, err.message);

        dbus_error_free(&err);
        return -1;
    }

    if (!dbus_message_get_args(r, &err, DBUS_TYPE_UNIX_FD, &ret, DBUS_TYPE_UINT16, &i, DBUS_TYPE_UINT16, &o,
                               DBUS_TYPE_INVALID)) {
        pa_log_error("Failed to parse %s() reply: %s", method, err.message);
        dbus_error_free(&err);
        ret = -1;
        goto finish;
    }

    if (imtu)
        *imtu = i;

    if (omtu)
        *omtu = o;

finish:
    dbus_message_unref(r);
    return ret;
}

static void bluez5_transport_release_cb(pa_bluetooth_transport *t) {
    DBusMessage *m;
    DBusError err;

    pa_assert(t);
    pa_assert(t->device);
    pa_assert(t->device->discovery);

    dbus_error_init(&err);

    if (t->state <= PA_BLUETOOTH_TRANSPORT_STATE_IDLE) {
        pa_log_info("Transport %s auto-released by BlueZ or already released", t->path);
        return;
    }

    pa_assert_se(m = dbus_message_new_method_call(t->owner, t->path, BLUEZ_MEDIA_TRANSPORT_INTERFACE, "Release"));
    dbus_connection_send_with_reply_and_block(pa_dbus_connection_get(t->device->discovery->connection), m, -1, &err);

    if (dbus_error_is_set(&err)) {
        pa_log_error("Failed to release transport %s: %s", t->path, err.message);
        dbus_error_free(&err);
    } else
        pa_log_info("Transport %s released", t->path);
}

bool pa_bluetooth_device_any_transport_connected(const pa_bluetooth_device *d) {
    unsigned i;

    pa_assert(d);

    if (d->device_info_valid != 1)
        return false;

    for (i = 0; i < PA_BLUETOOTH_PROFILE_COUNT; i++)
        if (d->transports[i] && d->transports[i]->state != PA_BLUETOOTH_TRANSPORT_STATE_DISCONNECTED)
            return true;

    return false;
}

static pa_bluetooth_device* device_create(pa_bluetooth_discovery *y, const char *path) {
    pa_bluetooth_device *d;

    pa_assert(y);
    pa_assert(path);

    d = pa_xnew0(pa_bluetooth_device, 1);
    d->discovery = y;
    d->path = pa_xstrdup(path);

    pa_hashmap_put(y->devices, d->path, d);

    return d;
}

pa_bluetooth_device* pa_bluetooth_discovery_get_device_by_path(pa_bluetooth_discovery *y, const char *path) {
    pa_bluetooth_device *d;

    pa_assert(y);
    pa_assert(PA_REFCNT_VALUE(y) > 0);
    pa_assert(path);

    if ((d = pa_hashmap_get(y->devices, path)))
        if (d->device_info_valid == 1)
            return d;

    return NULL;
}

pa_bluetooth_device* pa_bluetooth_discovery_get_device_by_address(pa_bluetooth_discovery *y, const char *remote, const char *local) {
    pa_bluetooth_device *d;
    void *state = NULL;

    pa_assert(y);
    pa_assert(PA_REFCNT_VALUE(y) > 0);
    pa_assert(remote);
    pa_assert(local);

    while ((d = pa_hashmap_iterate(y->devices, &state, NULL)))
        if (pa_streq(d->address, remote) && pa_streq(d->adapter->address, local))
            return d->device_info_valid == 1 ? d : NULL;

    return NULL;
}

static void device_free(pa_bluetooth_device *d) {
    unsigned i;

    pa_assert(d);

    for (i = 0; i < PA_BLUETOOTH_PROFILE_COUNT; i++) {
        pa_bluetooth_transport *t;

        if (!(t = d->transports[i]))
            continue;

        transport_state_changed(t, PA_BLUETOOTH_TRANSPORT_STATE_DISCONNECTED);
        pa_bluetooth_transport_free(t);
    }

    d->discovery = NULL;
    d->adapter = NULL;
    pa_xfree(d->path);
    pa_xfree(d->alias);
    pa_xfree(d->address);
    pa_xfree(d);
}

static void device_remove(pa_bluetooth_discovery *y, const char *path) {
    pa_bluetooth_device *d;

    if (!(d = pa_hashmap_remove(y->devices, path)))
        pa_log_warn("Unknown device removed %s", path);
    else {
        pa_log_debug("Device %s removed", path);
        device_free(d);
    }
}

static void device_remove_all(pa_bluetooth_discovery *y) {
    pa_bluetooth_device *d;

    pa_assert(y);

    while ((d = pa_hashmap_steal_first(y->devices))) {
        d->device_info_valid = -1;
        pa_hook_fire(&y->hooks[PA_BLUETOOTH_HOOK_DEVICE_CONNECTION_CHANGED], d);
        device_free(d);
   }
}

static pa_bluetooth_adapter* adapter_create(pa_bluetooth_discovery *y, const char *path) {
    pa_bluetooth_adapter *a;

    pa_assert(y);
    pa_assert(path);

    a = pa_xnew0(pa_bluetooth_adapter, 1);
    a->discovery = y;
    a->path = pa_xstrdup(path);

    pa_hashmap_put(y->adapters, a->path, a);

    return a;
}

static void adapter_remove_all(pa_bluetooth_discovery *y) {
    pa_bluetooth_adapter *a;

    pa_assert(y);

    /* When this function is called all devices have already been freed */

    while ((a = pa_hashmap_steal_first(y->adapters))) {
        pa_xfree(a->path);
        pa_xfree(a->address);
        pa_xfree(a);
    }
}

static void get_managed_objects_reply(DBusPendingCall *pending, void *userdata) {
    pa_dbus_pending *p;
    pa_bluetooth_discovery *y;
    DBusMessage *r;
    DBusMessageIter arg_i, element_i;

    pa_assert_se(p = userdata);
    pa_assert_se(y = p->context_data);
    pa_assert_se(r = dbus_pending_call_steal_reply(pending));

    if (dbus_message_is_error(r, DBUS_ERROR_UNKNOWN_METHOD)) {
        pa_log_warn("BlueZ D-Bus ObjectManager not available");
        goto finish;
    }

    if (dbus_message_get_type(r) == DBUS_MESSAGE_TYPE_ERROR) {
        pa_log_error("GetManagedObjects() failed: %s: %s", dbus_message_get_error_name(r), pa_dbus_get_error_message(r));
        goto finish;
    }

    if (!dbus_message_iter_init(r, &arg_i) || !pa_streq(dbus_message_get_signature(r), "a{oa{sa{sv}}}")) {
        pa_log_error("Invalid reply signature for GetManagedObjects()");
        goto finish;
    }

    dbus_message_iter_recurse(&arg_i, &element_i);
    while (dbus_message_iter_get_arg_type(&element_i) == DBUS_TYPE_DICT_ENTRY) {
        DBusMessageIter dict_i;

        dbus_message_iter_recurse(&element_i, &dict_i);

        /* TODO: parse interfaces and properties */

        dbus_message_iter_next(&element_i);
    }

    y->objects_listed = true;

finish:
    dbus_message_unref(r);

    PA_LLIST_REMOVE(pa_dbus_pending, y->pending, p);
    pa_dbus_pending_free(p);
}

static void get_managed_objects(pa_bluetooth_discovery *y) {
    DBusMessage *m;

    pa_assert(y);

    pa_assert_se(m = dbus_message_new_method_call(BLUEZ_SERVICE, "/", "org.freedesktop.DBus.ObjectManager",
                                                  "GetManagedObjects"));
    send_and_add_to_pending(y, m, get_managed_objects_reply, NULL);
}

pa_hook* pa_bluetooth_discovery_hook(pa_bluetooth_discovery *y, pa_bluetooth_hook_t hook) {
    pa_assert(y);
    pa_assert(PA_REFCNT_VALUE(y) > 0);

    return &y->hooks[hook];
}

static DBusHandlerResult filter_cb(DBusConnection *bus, DBusMessage *m, void *userdata) {
    pa_bluetooth_discovery *y;
    DBusError err;

    pa_assert(bus);
    pa_assert(m);
    pa_assert_se(y = userdata);

    dbus_error_init(&err);

    if (dbus_message_is_signal(m, "org.freedesktop.DBus", "NameOwnerChanged")) {
        const char *name, *old_owner, *new_owner;

        if (!dbus_message_get_args(m, &err,
                                   DBUS_TYPE_STRING, &name,
                                   DBUS_TYPE_STRING, &old_owner,
                                   DBUS_TYPE_STRING, &new_owner,
                                   DBUS_TYPE_INVALID)) {
            pa_log_error("Failed to parse org.freedesktop.DBus.NameOwnerChanged: %s", err.message);
            goto fail;
        }

        if (pa_streq(name, BLUEZ_SERVICE)) {
            if (old_owner && *old_owner) {
                pa_log_debug("Bluetooth daemon disappeared");
                device_remove_all(y);
                adapter_remove_all(y);
                y->objects_listed = false;
            }

            if (new_owner && *new_owner) {
                pa_log_debug("Bluetooth daemon appeared");
                get_managed_objects(y);
            }
        }

        return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
    }

fail:
    dbus_error_free(&err);

    return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
}

static uint8_t a2dp_default_bitpool(uint8_t freq, uint8_t mode) {
    /* These bitpool values were chosen based on the A2DP spec recommendation */
    switch (freq) {
        case SBC_SAMPLING_FREQ_16000:
        case SBC_SAMPLING_FREQ_32000:
            return 53;

        case SBC_SAMPLING_FREQ_44100:

            switch (mode) {
                case SBC_CHANNEL_MODE_MONO:
                case SBC_CHANNEL_MODE_DUAL_CHANNEL:
                    return 31;

                case SBC_CHANNEL_MODE_STEREO:
                case SBC_CHANNEL_MODE_JOINT_STEREO:
                    return 53;
            }

            pa_log_warn("Invalid channel mode %u", mode);
            return 53;

        case SBC_SAMPLING_FREQ_48000:

            switch (mode) {
                case SBC_CHANNEL_MODE_MONO:
                case SBC_CHANNEL_MODE_DUAL_CHANNEL:
                    return 29;

                case SBC_CHANNEL_MODE_STEREO:
                case SBC_CHANNEL_MODE_JOINT_STEREO:
                    return 51;
            }

            pa_log_warn("Invalid channel mode %u", mode);
            return 51;
    }

    pa_log_warn("Invalid sampling freq %u", freq);
    return 53;
}

const char *pa_bluetooth_profile_to_string(pa_bluetooth_profile_t profile) {
    switch(profile) {
        case PA_BLUETOOTH_PROFILE_A2DP_SINK:
            return "a2dp_sink";
        case PA_BLUETOOTH_PROFILE_A2DP_SOURCE:
            return "a2dp_source";
        case PA_BLUETOOTH_PROFILE_OFF:
            return "off";
    }

    return NULL;
}

static DBusMessage *endpoint_set_configuration(DBusConnection *conn, DBusMessage *m, void *userdata) {
    pa_bluetooth_discovery *y = userdata;
    pa_bluetooth_device *d;
    pa_bluetooth_transport *t;
    const char *sender, *path, *endpoint_path, *dev_path = NULL, *uuid = NULL;
    const uint8_t *config = NULL;
    int size = 0;
    pa_bluetooth_profile_t p = PA_BLUETOOTH_PROFILE_OFF;
    DBusMessageIter args, props;
    DBusMessage *r;

    if (!dbus_message_iter_init(m, &args) || !pa_streq(dbus_message_get_signature(m), "oa{sv}")) {
        pa_log_error("Invalid signature for method SetConfiguration()");
        goto fail2;
    }

    dbus_message_iter_get_basic(&args, &path);

    if (pa_hashmap_get(y->transports, path)) {
        pa_log_error("Endpoint SetConfiguration(): Transport %s is already configured.", path);
        goto fail2;
    }

    pa_assert_se(dbus_message_iter_next(&args));

    dbus_message_iter_recurse(&args, &props);
    if (dbus_message_iter_get_arg_type(&props) != DBUS_TYPE_DICT_ENTRY)
        goto fail;

    /* Read transport properties */
    while (dbus_message_iter_get_arg_type(&props) == DBUS_TYPE_DICT_ENTRY) {
        const char *key;
        DBusMessageIter value, entry;
        int var;

        dbus_message_iter_recurse(&props, &entry);
        dbus_message_iter_get_basic(&entry, &key);

        dbus_message_iter_next(&entry);
        dbus_message_iter_recurse(&entry, &value);

        var = dbus_message_iter_get_arg_type(&value);

        if (pa_streq(key, "UUID")) {
            if (var != DBUS_TYPE_STRING) {
                pa_log_error("Property %s of wrong type %c", key, (char)var);
                goto fail;
            }

            dbus_message_iter_get_basic(&value, &uuid);

            endpoint_path = dbus_message_get_path(m);
            if (pa_streq(endpoint_path, A2DP_SOURCE_ENDPOINT)) {
                if (pa_streq(uuid, PA_BLUETOOTH_UUID_A2DP_SOURCE))
                    p = PA_BLUETOOTH_PROFILE_A2DP_SINK;
            } else if (pa_streq(endpoint_path, A2DP_SINK_ENDPOINT)) {
                if (pa_streq(uuid, PA_BLUETOOTH_UUID_A2DP_SINK))
                    p = PA_BLUETOOTH_PROFILE_A2DP_SOURCE;
            }

            if (p == PA_BLUETOOTH_PROFILE_OFF) {
                pa_log_error("UUID %s of transport %s incompatible with endpoint %s", uuid, path, endpoint_path);
                goto fail;
            }
        } else if (pa_streq(key, "Device")) {
            if (var != DBUS_TYPE_OBJECT_PATH) {
                pa_log_error("Property %s of wrong type %c", key, (char)var);
                goto fail;
            }

            dbus_message_iter_get_basic(&value, &dev_path);
        } else if (pa_streq(key, "Configuration")) {
            DBusMessageIter array;
            a2dp_sbc_t *c;

            if (var != DBUS_TYPE_ARRAY) {
                pa_log_error("Property %s of wrong type %c", key, (char)var);
                goto fail;
            }

            dbus_message_iter_recurse(&value, &array);
            var = dbus_message_iter_get_arg_type(&array);
            if (var != DBUS_TYPE_BYTE) {
                pa_log_error("%s is an array of wrong type %c", key, (char)var);
                goto fail;
            }

            dbus_message_iter_get_fixed_array(&array, &config, &size);
            if (size != sizeof(a2dp_sbc_t)) {
                pa_log_error("Configuration array of invalid size");
                goto fail;
            }

            c = (a2dp_sbc_t *) config;

            if (c->frequency != SBC_SAMPLING_FREQ_16000 && c->frequency != SBC_SAMPLING_FREQ_32000 &&
                c->frequency != SBC_SAMPLING_FREQ_44100 && c->frequency != SBC_SAMPLING_FREQ_48000) {
                pa_log_error("Invalid sampling frequency in configuration");
                goto fail;
            }

            if (c->channel_mode != SBC_CHANNEL_MODE_MONO && c->channel_mode != SBC_CHANNEL_MODE_DUAL_CHANNEL &&
                c->channel_mode != SBC_CHANNEL_MODE_STEREO && c->channel_mode != SBC_CHANNEL_MODE_JOINT_STEREO) {
                pa_log_error("Invalid channel mode in configuration");
                goto fail;
            }

            if (c->allocation_method != SBC_ALLOCATION_SNR && c->allocation_method != SBC_ALLOCATION_LOUDNESS) {
                pa_log_error("Invalid allocation method in configuration");
                goto fail;
            }

            if (c->subbands != SBC_SUBBANDS_4 && c->subbands != SBC_SUBBANDS_8) {
                pa_log_error("Invalid SBC subbands in configuration");
                goto fail;
            }

            if (c->block_length != SBC_BLOCK_LENGTH_4 && c->block_length != SBC_BLOCK_LENGTH_8 &&
                c->block_length != SBC_BLOCK_LENGTH_12 && c->block_length != SBC_BLOCK_LENGTH_16) {
                pa_log_error("Invalid block length in configuration");
                goto fail;
            }
        }

        dbus_message_iter_next(&props);
    }

    if ((d = pa_hashmap_get(y->devices, dev_path))) {
        if (d->device_info_valid == -1) {
            pa_log_error("Information about device %s is invalid", dev_path);
            goto fail2;
        }
    } else {
        /* InterfacesAdded signal is probably on it's way, device_info_valid is kept as 0. */
        pa_log_warn("SetConfiguration() received for unknown device %s", dev_path);
        d = device_create(y, dev_path);
    }

    if (d->transports[p] != NULL) {
        pa_log_error("Cannot configure transport %s because profile %s is already used", path, pa_bluetooth_profile_to_string(p));
        goto fail2;
    }

    sender = dbus_message_get_sender(m);

    pa_assert_se(r = dbus_message_new_method_return(m));
    pa_assert_se(dbus_connection_send(pa_dbus_connection_get(y->connection), r, NULL));
    dbus_message_unref(r);

    d->transports[p] = t = pa_bluetooth_transport_new(d, sender, path, p, config, size);
    t->acquire = bluez5_transport_acquire_cb;
    t->release = bluez5_transport_release_cb;
    pa_bluetooth_transport_put(t);

    pa_log_debug("Transport %s available for profile %s", t->path, pa_bluetooth_profile_to_string(t->profile));

    return NULL;

fail:
    pa_log_error("Endpoint SetConfiguration(): invalid arguments");

fail2:
    pa_assert_se(r = dbus_message_new_error(m, "org.bluez.Error.InvalidArguments", "Unable to set configuration"));
    return r;
}

static DBusMessage *endpoint_select_configuration(DBusConnection *conn, DBusMessage *m, void *userdata) {
    pa_bluetooth_discovery *y = userdata;
    a2dp_sbc_t *cap, config;
    uint8_t *pconf = (uint8_t *) &config;
    int i, size;
    DBusMessage *r;
    DBusError err;

    static const struct {
        uint32_t rate;
        uint8_t cap;
    } freq_table[] = {
        { 16000U, SBC_SAMPLING_FREQ_16000 },
        { 32000U, SBC_SAMPLING_FREQ_32000 },
        { 44100U, SBC_SAMPLING_FREQ_44100 },
        { 48000U, SBC_SAMPLING_FREQ_48000 }
    };

    dbus_error_init(&err);

    if (!dbus_message_get_args(m, &err, DBUS_TYPE_ARRAY, DBUS_TYPE_BYTE, &cap, &size, DBUS_TYPE_INVALID)) {
        pa_log_error("Endpoint SelectConfiguration(): %s", err.message);
        dbus_error_free(&err);
        goto fail;
    }

    if (size != sizeof(config)) {
        pa_log_error("Capabilities array has invalid size");
        goto fail;
    }

    pa_zero(config);

    /* Find the lowest freq that is at least as high as the requested sampling rate */
    for (i = 0; (unsigned) i < PA_ELEMENTSOF(freq_table); i++)
        if (freq_table[i].rate >= y->core->default_sample_spec.rate && (cap->frequency & freq_table[i].cap)) {
            config.frequency = freq_table[i].cap;
            break;
        }

    if ((unsigned) i == PA_ELEMENTSOF(freq_table)) {
        for (--i; i >= 0; i--) {
            if (cap->frequency & freq_table[i].cap) {
                config.frequency = freq_table[i].cap;
                break;
            }
        }

        if (i < 0) {
            pa_log_error("Not suitable sample rate");
            goto fail;
        }
    }

    pa_assert((unsigned) i < PA_ELEMENTSOF(freq_table));

    if (y->core->default_sample_spec.channels <= 1) {
        if (cap->channel_mode & SBC_CHANNEL_MODE_MONO)
            config.channel_mode = SBC_CHANNEL_MODE_MONO;
        else if (cap->channel_mode & SBC_CHANNEL_MODE_JOINT_STEREO)
            config.channel_mode = SBC_CHANNEL_MODE_JOINT_STEREO;
        else if (cap->channel_mode & SBC_CHANNEL_MODE_STEREO)
            config.channel_mode = SBC_CHANNEL_MODE_STEREO;
        else if (cap->channel_mode & SBC_CHANNEL_MODE_DUAL_CHANNEL)
            config.channel_mode = SBC_CHANNEL_MODE_DUAL_CHANNEL;
        else {
            pa_log_error("No supported channel modes");
            goto fail;
        }
    }

    if (y->core->default_sample_spec.channels >= 2) {
        if (cap->channel_mode & SBC_CHANNEL_MODE_JOINT_STEREO)
            config.channel_mode = SBC_CHANNEL_MODE_JOINT_STEREO;
        else if (cap->channel_mode & SBC_CHANNEL_MODE_STEREO)
            config.channel_mode = SBC_CHANNEL_MODE_STEREO;
        else if (cap->channel_mode & SBC_CHANNEL_MODE_DUAL_CHANNEL)
            config.channel_mode = SBC_CHANNEL_MODE_DUAL_CHANNEL;
        else if (cap->channel_mode & SBC_CHANNEL_MODE_MONO)
            config.channel_mode = SBC_CHANNEL_MODE_MONO;
        else {
            pa_log_error("No supported channel modes");
            goto fail;
        }
    }

    if (cap->block_length & SBC_BLOCK_LENGTH_16)
        config.block_length = SBC_BLOCK_LENGTH_16;
    else if (cap->block_length & SBC_BLOCK_LENGTH_12)
        config.block_length = SBC_BLOCK_LENGTH_12;
    else if (cap->block_length & SBC_BLOCK_LENGTH_8)
        config.block_length = SBC_BLOCK_LENGTH_8;
    else if (cap->block_length & SBC_BLOCK_LENGTH_4)
        config.block_length = SBC_BLOCK_LENGTH_4;
    else {
        pa_log_error("No supported block lengths");
        goto fail;
    }

    if (cap->subbands & SBC_SUBBANDS_8)
        config.subbands = SBC_SUBBANDS_8;
    else if (cap->subbands & SBC_SUBBANDS_4)
        config.subbands = SBC_SUBBANDS_4;
    else {
        pa_log_error("No supported subbands");
        goto fail;
    }

    if (cap->allocation_method & SBC_ALLOCATION_LOUDNESS)
        config.allocation_method = SBC_ALLOCATION_LOUDNESS;
    else if (cap->allocation_method & SBC_ALLOCATION_SNR)
        config.allocation_method = SBC_ALLOCATION_SNR;

    config.min_bitpool = (uint8_t) PA_MAX(MIN_BITPOOL, cap->min_bitpool);
    config.max_bitpool = (uint8_t) PA_MIN(a2dp_default_bitpool(config.frequency, config.channel_mode), cap->max_bitpool);

    if (config.min_bitpool > config.max_bitpool)
        goto fail;

    pa_assert_se(r = dbus_message_new_method_return(m));
    pa_assert_se(dbus_message_append_args(r, DBUS_TYPE_ARRAY, DBUS_TYPE_BYTE, &pconf, size, DBUS_TYPE_INVALID));

    return r;

fail:
    pa_assert_se(r = dbus_message_new_error(m, "org.bluez.Error.InvalidArguments", "Unable to select configuration"));
    return r;
}

static DBusMessage *endpoint_clear_configuration(DBusConnection *conn, DBusMessage *m, void *userdata) {
    pa_bluetooth_discovery *y = userdata;
    pa_bluetooth_transport *t;
    DBusMessage *r;
    DBusError err;
    const char *path;

    dbus_error_init(&err);

    if (!dbus_message_get_args(m, &err, DBUS_TYPE_OBJECT_PATH, &path, DBUS_TYPE_INVALID)) {
        pa_log_error("Endpoint ClearConfiguration(): %s", err.message);
        dbus_error_free(&err);
        goto fail;
    }

    if ((t = pa_hashmap_get(y->transports, path))) {
        pa_log_debug("Clearing transport %s profile %s", t->path, pa_bluetooth_profile_to_string(t->profile));
        transport_state_changed(t, PA_BLUETOOTH_TRANSPORT_STATE_DISCONNECTED);
        pa_bluetooth_transport_free(t);
    }

    pa_assert_se(r = dbus_message_new_method_return(m));

    return r;

fail:
    pa_assert_se(r = dbus_message_new_error(m, "org.bluez.Error.InvalidArguments", "Unable to clear configuration"));
    return r;
}

static DBusMessage *endpoint_release(DBusConnection *conn, DBusMessage *m, void *userdata) {
    DBusMessage *r;

    pa_assert_se(r = dbus_message_new_error(m, BLUEZ_MEDIA_ENDPOINT_INTERFACE ".Error.NotImplemented",
                                            "Method not implemented"));

    return r;
}

static DBusHandlerResult endpoint_handler(DBusConnection *c, DBusMessage *m, void *userdata) {
    struct pa_bluetooth_discovery *y = userdata;
    DBusMessage *r = NULL;
    const char *path, *interface, *member;

    pa_assert(y);

    path = dbus_message_get_path(m);
    interface = dbus_message_get_interface(m);
    member = dbus_message_get_member(m);

    pa_log_debug("dbus: path=%s, interface=%s, member=%s", path, interface, member);

    if (!pa_streq(path, A2DP_SOURCE_ENDPOINT) && !pa_streq(path, A2DP_SINK_ENDPOINT))
        return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;

    if (dbus_message_is_method_call(m, "org.freedesktop.DBus.Introspectable", "Introspect")) {
        const char *xml = ENDPOINT_INTROSPECT_XML;

        pa_assert_se(r = dbus_message_new_method_return(m));
        pa_assert_se(dbus_message_append_args(r, DBUS_TYPE_STRING, &xml, DBUS_TYPE_INVALID));

    } else if (dbus_message_is_method_call(m, BLUEZ_MEDIA_ENDPOINT_INTERFACE, "SetConfiguration"))
        r = endpoint_set_configuration(c, m, userdata);
    else if (dbus_message_is_method_call(m, BLUEZ_MEDIA_ENDPOINT_INTERFACE, "SelectConfiguration"))
        r = endpoint_select_configuration(c, m, userdata);
    else if (dbus_message_is_method_call(m, BLUEZ_MEDIA_ENDPOINT_INTERFACE, "ClearConfiguration"))
        r = endpoint_clear_configuration(c, m, userdata);
    else if (dbus_message_is_method_call(m, BLUEZ_MEDIA_ENDPOINT_INTERFACE, "Release"))
        r = endpoint_release(c, m, userdata);
    else
        return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;

    if (r) {
        pa_assert_se(dbus_connection_send(pa_dbus_connection_get(y->connection), r, NULL));
        dbus_message_unref(r);
    }

    return DBUS_HANDLER_RESULT_HANDLED;
}

static void endpoint_init(pa_bluetooth_discovery *y, pa_bluetooth_profile_t profile) {
    static const DBusObjectPathVTable vtable_endpoint = {
        .message_function = endpoint_handler,
    };

    pa_assert(y);

    switch(profile) {
        case PA_BLUETOOTH_PROFILE_A2DP_SINK:
            pa_assert_se(dbus_connection_register_object_path(pa_dbus_connection_get(y->connection), A2DP_SOURCE_ENDPOINT,
                                                              &vtable_endpoint, y));
            break;
        case PA_BLUETOOTH_PROFILE_A2DP_SOURCE:
            pa_assert_se(dbus_connection_register_object_path(pa_dbus_connection_get(y->connection), A2DP_SINK_ENDPOINT,
                                                              &vtable_endpoint, y));
            break;
        default:
            pa_assert_not_reached();
            break;
    }
}

static void endpoint_done(pa_bluetooth_discovery *y, pa_bluetooth_profile_t profile) {
    pa_assert(y);

    switch(profile) {
        case PA_BLUETOOTH_PROFILE_A2DP_SINK:
            dbus_connection_unregister_object_path(pa_dbus_connection_get(y->connection), A2DP_SOURCE_ENDPOINT);
            break;
        case PA_BLUETOOTH_PROFILE_A2DP_SOURCE:
            dbus_connection_unregister_object_path(pa_dbus_connection_get(y->connection), A2DP_SINK_ENDPOINT);
            break;
        default:
            pa_assert_not_reached();
            break;
    }
}

pa_bluetooth_discovery* pa_bluetooth_discovery_get(pa_core *c) {
    pa_bluetooth_discovery *y;
    DBusError err;
    DBusConnection *conn;
    unsigned i;

    if ((y = pa_shared_get(c, "bluetooth-discovery")))
        return pa_bluetooth_discovery_ref(y);

    y = pa_xnew0(pa_bluetooth_discovery, 1);
    PA_REFCNT_INIT(y);
    y->core = c;
    y->adapters = pa_hashmap_new(pa_idxset_string_hash_func, pa_idxset_string_compare_func);
    y->devices = pa_hashmap_new(pa_idxset_string_hash_func, pa_idxset_string_compare_func);
    y->transports = pa_hashmap_new(pa_idxset_string_hash_func, pa_idxset_string_compare_func);
    PA_LLIST_HEAD_INIT(pa_dbus_pending, y->pending);

    for (i = 0; i < PA_BLUETOOTH_HOOK_MAX; i++)
        pa_hook_init(&y->hooks[i], y);

    pa_shared_set(c, "bluetooth-discovery", y);

    dbus_error_init(&err);

    if (!(y->connection = pa_dbus_bus_get(y->core, DBUS_BUS_SYSTEM, &err))) {
        pa_log_error("Failed to get D-Bus connection: %s", err.message);
        goto fail;
    }

    conn = pa_dbus_connection_get(y->connection);

    /* dynamic detection of bluetooth audio devices */
    if (!dbus_connection_add_filter(conn, filter_cb, y, NULL)) {
        pa_log_error("Failed to add filter function");
        goto fail;
    }
    y->filter_added = true;

    if (pa_dbus_add_matches(conn, &err,
            "type='signal',sender='org.freedesktop.DBus',interface='org.freedesktop.DBus',member='NameOwnerChanged'"
            ",arg0='" BLUEZ_SERVICE "'",
            NULL) < 0) {
        pa_log_error("Failed to add D-Bus matches: %s", err.message);
        goto fail;
    }
    y->matches_added = true;

    endpoint_init(y, PA_BLUETOOTH_PROFILE_A2DP_SINK);
    endpoint_init(y, PA_BLUETOOTH_PROFILE_A2DP_SOURCE);

    get_managed_objects(y);

    return y;

fail:
    pa_bluetooth_discovery_unref(y);
    dbus_error_free(&err);

    return NULL;
}

pa_bluetooth_discovery* pa_bluetooth_discovery_ref(pa_bluetooth_discovery *y) {
    pa_assert(y);
    pa_assert(PA_REFCNT_VALUE(y) > 0);

    PA_REFCNT_INC(y);

    return y;
}

void pa_bluetooth_discovery_unref(pa_bluetooth_discovery *y) {
    pa_assert(y);
    pa_assert(PA_REFCNT_VALUE(y) > 0);

    if (PA_REFCNT_DEC(y) > 0)
        return;

    pa_dbus_free_pending_list(&y->pending);

    if (y->devices) {
        device_remove_all(y);
        pa_hashmap_free(y->devices);
    }

    if (y->adapters) {
        adapter_remove_all(y);
        pa_hashmap_free(y->adapters);
    }

    if (y->transports) {
        pa_assert(pa_hashmap_isempty(y->transports));
        pa_hashmap_free(y->transports);
    }

    if (y->connection) {

        if (y->matches_added)
            pa_dbus_remove_matches(pa_dbus_connection_get(y->connection),
                "type='signal',sender='org.freedesktop.DBus',interface='org.freedesktop.DBus',member='NameOwnerChanged',"
                "arg0='" BLUEZ_SERVICE "'",
                NULL);

        if (y->filter_added)
            dbus_connection_remove_filter(pa_dbus_connection_get(y->connection), filter_cb, y);

        endpoint_done(y, PA_BLUETOOTH_PROFILE_A2DP_SINK);
        endpoint_done(y, PA_BLUETOOTH_PROFILE_A2DP_SOURCE);

        pa_dbus_connection_unref(y->connection);
    }

    pa_shared_remove(y->core, "bluetooth-discovery");
    pa_xfree(y);
}