[pulseaudio-discuss] [PATCH 5/5] backend-native: add a new native headset backend

Arun Raghavan arun at accosted.net
Wed Sep 10 21:32:22 PDT 2014


On 8 September 2014 14:45, Wim Taymans <wim.taymans at gmail.com> wrote:
> Add a simple native headset backend that implements support for the
> blutooth HSP profile.
> This allows pulseaudio to output audio to a Headset using the HSP profile.
>
> Make the native backend the default.

Thanks for taking this up.

tbh, I still think this should be in BlueZ, but since that seems to be
a dead end, and creating a new daemon is probably more work that it's
worth, let's go with this approach.

Luiz, would you also have the time to take a look over this?

> ---
>  configure.ac                           |   6 +-
>  src/modules/bluetooth/backend-native.c | 474 +++++++++++++++++++++++++++++++++
>  2 files changed, 477 insertions(+), 3 deletions(-)
>  create mode 100644 src/modules/bluetooth/backend-native.c
>
> diff --git a/configure.ac b/configure.ac
> index e1e2572..a91639f 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -1030,14 +1030,14 @@ AM_CONDITIONAL([HAVE_BLUEZ], [test "x$HAVE_BLUEZ" = x1])
>  ## Bluetooth Headset profiles backend ##
>
>  AC_ARG_WITH(bluetooth_headset_backend,
> -    AS_HELP_STRING([--with-bluetooth-headset-backend=<ofono|null>],[Backend for Bluetooth headset profiles (ofono)]))
> +    AS_HELP_STRING([--with-bluetooth-headset-backend=<ofono|native|null>],[Backend for Bluetooth headset profiles (native)]))
>  if test -z "$with_bluetooth_headset_backend" ; then
> -    BLUETOOTH_HEADSET_BACKEND=ofono
> +    BLUETOOTH_HEADSET_BACKEND=native
>  else
>      BLUETOOTH_HEADSET_BACKEND=$with_bluetooth_headset_backend
>  fi
>
> -AS_IF([test "x$BLUETOOTH_HEADSET_BACKEND" != "xofono" && test "x$BLUETOOTH_HEADSET_BACKEND" != "xnull"],
> +AS_IF([test "x$BLUETOOTH_HEADSET_BACKEND" != "xofono" && test "x$BLUETOOTH_HEADSET_BACKEND" != "xnull" && test "x$BLUETOOTH_HEADSET_BACKEND" != "xnative"],
>      [AC_MSG_ERROR([*** Invalid Bluetooth Headset backend])])
>
>  AC_SUBST(BLUETOOTH_HEADSET_BACKEND)
> diff --git a/src/modules/bluetooth/backend-native.c b/src/modules/bluetooth/backend-native.c
> new file mode 100644
> index 0000000..8af610c
> --- /dev/null
> +++ b/src/modules/bluetooth/backend-native.c
> @@ -0,0 +1,474 @@
> +/***
> +  This file is part of PulseAudio.
> +
> +  Copyright 2014 Wim Taymans <wim.taymans at gmail.com>
> +
> +  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 <pulsecore/shared.h>
> +#include <pulsecore/core-error.h>
> +#include <pulsecore/core-util.h>
> +#include <pulsecore/dbus-shared.h>
> +#include <pulsecore/log.h>
> +
> +#include <errno.h>
> +#include <sys/types.h>
> +#include <sys/socket.h>
> +
> +#include <bluetooth/bluetooth.h>
> +#include <bluetooth/sco.h>
> +
> +#include "bluez5-util.h"
> +
> +struct pa_bluetooth_backend {
> +  pa_core *core;
> +  pa_dbus_connection *connection;
> +  pa_bluetooth_discovery *discovery;
> +
> +  PA_LLIST_HEAD(pa_dbus_pending, pending);
> +};
> +
> +struct transport_rfcomm {
> +    int rfcomm_fd;
> +    pa_io_event *rfcomm_io;
> +    pa_bluetooth_backend *backend;
> +};
> +
> +#define BLUEZ_SERVICE "org.bluez"
> +#define BLUEZ_MEDIA_TRANSPORT_INTERFACE BLUEZ_SERVICE ".MediaTransport1"
> +
> +#define BLUEZ_ERROR_NOT_SUPPORTED "org.bluez.Error.NotSupported"
> +
> +#define BLUEZ_PROFILE_MANAGER_INTERFACE BLUEZ_SERVICE ".ProfileManager1"
> +#define BLUEZ_PROFILE_INTERFACE BLUEZ_SERVICE ".Profile1"
> +
> +#define HSP_AG_PROFILE "/Profile/HSPAGProfile"
> +
> +#define PROFILE_INTROSPECT_XML                                          \
> +    DBUS_INTROSPECT_1_0_XML_DOCTYPE_DECL_NODE                           \
> +    "<node>"                                                            \
> +    " <interface name=\"" BLUEZ_PROFILE_INTERFACE "\">"                 \
> +    "  <method name=\"Release\">"                                       \
> +    "  </method>"                                                       \
> +    "  <method name=\"Cancel\">"                                        \
> +    "  </method>"                                                       \
> +    "  <method name=\"RequestDisconnection\">"                          \
> +    "   <arg name=\"device\" direction=\"in\" type=\"o\"/>"             \
> +    "  </method>"                                                       \
> +    "  <method name=\"NewConnection\">"                                 \
> +    "   <arg name=\"device\" direction=\"in\" type=\"o\"/>"             \
> +    "   <arg name=\"fd\" direction=\"in\" type=\"h\"/>"                 \
> +    "   <arg name=\"opts\" direction=\"in\" type=\"a{sv}\"/>"           \
> +    "  </method>"                                                       \
> +    " </interface>"                                                     \
> +    " <interface name=\"org.freedesktop.DBus.Introspectable\">"         \
> +    "  <method name=\"Introspect\">"                                    \
> +    "   <arg name=\"data\" type=\"s\" direction=\"out\"/>"              \
> +    "  </method>"                                                       \
> +    " </interface>"                                                     \
> +    "</node>"
> +
> +static pa_dbus_pending* send_and_add_to_pending(pa_bluetooth_backend *backend, DBusMessage *m,
> +                                                DBusPendingCallNotifyFunction func, void *call_data) {
> +    pa_dbus_pending *p;
> +    DBusPendingCall *call;
> +
> +    pa_assert(backend);
> +    pa_assert(m);
> +
> +    pa_assert_se(dbus_connection_send_with_reply(pa_dbus_connection_get(backend->connection), m, &call, -1));
> +
> +    p = pa_dbus_pending_new(pa_dbus_connection_get(backend->connection), m, call, backend, call_data);
> +    PA_LLIST_PREPEND(pa_dbus_pending, backend->pending, p);
> +    dbus_pending_call_set_notify(call, func, p, NULL);
> +
> +    return p;
> +}
> +
> +static int bluez5_sco_acquire_cb(pa_bluetooth_transport *t, bool optional, size_t *imtu, size_t *omtu) {
> +    pa_bluetooth_device *d = t->device;
> +    struct sockaddr_sco addr;
> +    int err, i;
> +    int sock;
> +    bdaddr_t src;
> +    bdaddr_t dst;
> +    const char *src_addr, *dst_addr;
> +
> +    src_addr = d->adapter->address;
> +    dst_addr = d->address;
> +
> +    for (i = 5; i >= 0; i--, src_addr += 3)
> +        src.b[i] = strtol(src_addr, NULL, 16);
> +    for (i = 5; i >= 0; i--, dst_addr += 3)
> +        dst.b[i] = strtol(dst_addr, NULL, 16);
> +
> +    sock = socket(PF_BLUETOOTH, SOCK_SEQPACKET, BTPROTO_SCO);
> +    if (sock < 0) {
> +        pa_log_error("socket(SEQPACKET, SCO) %s", pa_cstrerror(errno));
> +        return -1;
> +    }
> +
> +    memset(&addr, 0, sizeof(addr));
> +    addr.sco_family = AF_BLUETOOTH;
> +    bacpy(&addr.sco_bdaddr, &src);
> +
> +    if (bind(sock, (struct sockaddr *) &addr, sizeof(addr)) < 0) {
> +        pa_log_error("bind(): %s", pa_cstrerror(errno));
> +        goto fail_close;
> +    }
> +
> +    memset(&addr, 0, sizeof(addr));
> +    addr.sco_family = AF_BLUETOOTH;
> +    bacpy(&addr.sco_bdaddr, &dst);
> +
> +    pa_log_info ("doing connect\n");
> +    err = connect(sock, (struct sockaddr *) &addr, sizeof(addr));
> +    if (err < 0 && !(errno == EAGAIN || errno == EINPROGRESS)) {
> +        pa_log_error("connect(): %s", pa_cstrerror(errno));
> +        goto fail_close;
> +    }
> +
> +    if (imtu)
> +        *imtu = 48;
> +
> +    if (omtu)
> +        *omtu = 48;

Out of curiosity, are these values fixed in the spec?

> +
> +    return sock;
> +
> +fail_close:
> +    close(sock);
> +    return -1;
> +}
> +
> +static void bluez5_sco_release_cb(pa_bluetooth_transport *t) {
> +    pa_log_info("Transport %s released", t->path);
> +}
> +
> +static void register_profile_reply(DBusPendingCall *pending, void *userdata) {
> +    DBusMessage *r;
> +    pa_dbus_pending *p;
> +    pa_bluetooth_backend *b;
> +    char *profile;
> +
> +    pa_assert(pending);
> +    pa_assert_se(p = userdata);
> +    pa_assert_se(b = p->context_data);
> +    pa_assert_se(profile = p->call_data);
> +    pa_assert_se(r = dbus_pending_call_steal_reply(pending));
> +
> +    if (dbus_message_is_error(r, BLUEZ_ERROR_NOT_SUPPORTED)) {
> +        pa_log_info("Couldn't register profile %s because it is disabled in BlueZ", profile);
> +        goto finish;
> +    }
> +
> +    if (dbus_message_get_type(r) == DBUS_MESSAGE_TYPE_ERROR) {
> +        pa_log_error(BLUEZ_PROFILE_MANAGER_INTERFACE ".RegisterProfile() failed: %s: %s", dbus_message_get_error_name(r),
> +                     pa_dbus_get_error_message(r));
> +        goto finish;
> +    }
> +
> +finish:
> +    dbus_message_unref(r);
> +
> +    PA_LLIST_REMOVE(pa_dbus_pending, b->pending, p);
> +    pa_dbus_pending_free(p);
> +
> +    pa_xfree(profile);
> +}
> +
> +static void register_profile(pa_bluetooth_backend *b, const char *profile, const char *uuid) {
> +    DBusMessage *m;
> +    DBusMessageIter i, d;
> +
> +    pa_log_debug("Registering Profile %s", profile);
> +
> +    pa_assert_se(m = dbus_message_new_method_call(BLUEZ_SERVICE, "/org/bluez", BLUEZ_PROFILE_MANAGER_INTERFACE, "RegisterProfile"));
> +
> +    dbus_message_iter_init_append(m, &i);
> +    dbus_message_iter_append_basic(&i, DBUS_TYPE_OBJECT_PATH, &profile);
> +    dbus_message_iter_append_basic(&i, DBUS_TYPE_STRING, &uuid);
> +    dbus_message_iter_open_container(&i, DBUS_TYPE_ARRAY, DBUS_DICT_ENTRY_BEGIN_CHAR_AS_STRING DBUS_TYPE_STRING_AS_STRING
> +                                         DBUS_TYPE_VARIANT_AS_STRING DBUS_DICT_ENTRY_END_CHAR_AS_STRING, &d);
> +    dbus_message_iter_close_container(&i, &d);
> +
> +    send_and_add_to_pending(b, m, register_profile_reply, pa_xstrdup(profile));
> +}
> +
> +static void rfcomm_io_callback(pa_mainloop_api *io, pa_io_event *e, int fd, pa_io_event_flags_t events, void*userdata) {
> +    pa_bluetooth_transport *t = userdata;
> +
> +    pa_assert(io);
> +    pa_assert(t);
> +
> +    if (events & (PA_IO_EVENT_HANGUP|PA_IO_EVENT_ERROR)) {
> +        pa_log("Lost RFCOMM connection.");
> +        goto fail;
> +    }
> +
> +    if (events & PA_IO_EVENT_INPUT) {
> +        char buf[512];
> +        ssize_t len;
> +
> +        len = read (fd, buf, 511);
> +        buf[len] = 0;
> +        pa_log("RFCOMM << %s", buf);
> +
> +        pa_log("RFCOMM >> OK");
> +        len = write (fd, "\r\nOK\r\n", 5);
> +        if (len < 0)
> +            pa_log_error("RFCOMM write error: %s", pa_cstrerror(errno));

Should we go to fail if this happens?

> +    }
> +    return;
> +
> +fail:
> +    pa_bluetooth_transport_free(t);
> +    return;
> +}
> +
> +static void transport_dispose(pa_bluetooth_transport *t) {
> +    struct transport_rfcomm *trfc = t->userdata;
> +
> +    trfc->backend->core->mainloop->io_free(trfc->rfcomm_io);
> +    shutdown (trfc->rfcomm_fd, SHUT_RDWR);
> +    close (trfc->rfcomm_fd);
> +
> +    pa_xfree(trfc);
> +}
> +
> +
> +static DBusMessage *profile_new_connection(DBusConnection *conn, DBusMessage *m, void *userdata) {
> +    pa_bluetooth_backend *b = userdata;
> +    pa_bluetooth_device *d;
> +    pa_bluetooth_transport *t;
> +    pa_bluetooth_profile_t p;
> +    DBusMessage *r;
> +    int fd;
> +    const char *sender, *path, *handler;
> +    DBusMessageIter arg_i, element_i;
> +    char *pathfd;
> +    struct transport_rfcomm *trfc;
> +
> +    if (!dbus_message_iter_init(m, &arg_i) || !pa_streq(dbus_message_get_signature(m), "oha{sv}")) {
> +        pa_log_error("Invalid signature found in NewConnection");
> +        goto fail;
> +    }
> +
> +    handler = dbus_message_get_path(m);
> +
> +    pa_assert(dbus_message_iter_get_arg_type(&arg_i) == DBUS_TYPE_OBJECT_PATH);
> +    dbus_message_iter_get_basic(&arg_i, &path);
> +
> +    d = pa_bluetooth_discovery_get_device_by_path(b->discovery, path);
> +    if (d == NULL) {
> +        pa_log_error("Device doesnt exist for %s", path);
> +        goto fail;
> +    }
> +
> +    if (pa_streq(handler, HSP_AG_PROFILE)) {
> +        p = PA_BLUETOOTH_PROFILE_HEADSET_HEAD_UNIT;
> +    } else
> +        goto refused;

Is the else possible at all?

> +
> +    pa_assert_se(dbus_message_iter_next(&arg_i));
> +
> +    pa_assert(dbus_message_iter_get_arg_type(&arg_i) == DBUS_TYPE_UNIX_FD);
> +    dbus_message_iter_get_basic(&arg_i, &fd);
> +
> +    pa_log_debug("dbus: NewConnection path=%s, fd=%d", path, fd);
> +
> +    pa_assert_se(dbus_message_iter_next(&arg_i));
> +    pa_assert(dbus_message_iter_get_arg_type(&arg_i) == DBUS_TYPE_ARRAY);
> +
> +    dbus_message_iter_recurse(&arg_i, &element_i);
> +
> +    while (dbus_message_iter_get_arg_type(&element_i) == DBUS_TYPE_DICT_ENTRY) {
> +        DBusMessageIter dict_i;
> +        const char *key;
> +
> +        dbus_message_iter_recurse(&element_i, &dict_i);
> +
> +        if (key == NULL)
> +            break;
> +        if (dbus_message_iter_get_arg_type(&dict_i) != DBUS_TYPE_STRING)
> +            break;
> +
> +        dbus_message_iter_get_basic(&dict_i, &key);
> +
> +        if (!dbus_message_iter_next(&dict_i))
> +            break;
> +
> +        if (dbus_message_iter_get_arg_type(&dict_i) != DBUS_TYPE_VARIANT)
> +            break;
> +
> +        pa_log_debug("key=%s", key);
> +
> +        dbus_message_iter_next(&element_i);
> +    }

If we're not doing anything with the keys, maybe we don't need to
parse any of this?

> +
> +    sender = dbus_message_get_sender(m);
> +
> +    pathfd = pa_sprintf_malloc ("%s/fd%d", path, fd);
> +    d->transports[p] = t = pa_bluetooth_transport_new(d, sender, pathfd, p, NULL, 0);
> +    pa_xfree(pathfd);
> +
> +    t->acquire = bluez5_sco_acquire_cb;
> +    t->release = bluez5_sco_release_cb;
> +    t->dispose = transport_dispose;
> +
> +    trfc =  pa_xnew0(struct transport_rfcomm, 1);
> +    trfc->rfcomm_fd = fd;
> +    trfc->rfcomm_io = b->core->mainloop->io_new(b->core->mainloop, fd, PA_IO_EVENT_INPUT|PA_IO_EVENT_HANGUP,
> +        rfcomm_io_callback, t);

Can reading/writing on the RFCOMM fd block the mainloop for long periods?

> +    trfc->backend = b;

Can the backend be destroyed before the transport? Maybe we should
only reference the mainloop instead of the backend here.

> +    t->userdata =  trfc;
> +
> +    pa_bluetooth_transport_put(t);
> +
> +    pa_log_debug("Transport %s available for profile %s", t->path, pa_bluetooth_profile_to_string(t->profile));
> +
> +    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 handle new connection"));
> +    return r;
> +refused:
> +    pa_log_debug("dbus: NewConnection path=%s rejected", path);
> +    pa_assert_se(r = dbus_message_new_error(m, "org.bluez.Error.Rejected", "New connection rejected"));
> +    return r;
> +}
> +
> +static DBusMessage *profile_request_disconnection(DBusConnection *conn, DBusMessage *m, void *userdata) {
> +    DBusMessage *r;
> +
> +    pa_assert_se(r = dbus_message_new_method_return(m));

How is the transport torn down in this case?

> +
> +    return r;
> +}
> +
> +static DBusHandlerResult profile_handler(DBusConnection *c, DBusMessage *m, void *userdata) {
> +    pa_bluetooth_backend *b = userdata;
> +    DBusMessage *r = NULL;
> +    const char *path, *interface, *member;
> +
> +    pa_assert(b);
> +
> +    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, HSP_AG_PROFILE))
> +        return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
> +
> +    if (dbus_message_is_method_call(m, "org.freedesktop.DBus.Introspectable", "Introspect")) {
> +        const char *xml = PROFILE_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_PROFILE_INTERFACE, "Release")) {
> +    } else if (dbus_message_is_method_call(m, BLUEZ_PROFILE_INTERFACE, "Cancel")) {

There doesn't actually seem to be a 'Cancel' method.

> +    } else if (dbus_message_is_method_call(m, BLUEZ_PROFILE_INTERFACE, "RequestDisconnection")) {
> +        r = profile_request_disconnection(c, m, userdata);
> +    } else if (dbus_message_is_method_call(m, BLUEZ_PROFILE_INTERFACE, "NewConnection"))
> +        r = profile_new_connection(c, m, userdata);
> +    else
> +        return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;
> +
> +    if (r) {
> +        pa_assert_se(dbus_connection_send(pa_dbus_connection_get(b->connection), r, NULL));
> +        dbus_message_unref(r);
> +    }
> +
> +    return DBUS_HANDLER_RESULT_HANDLED;
> +}
> +
> +static void profile_init(pa_bluetooth_backend *b, pa_bluetooth_profile_t profile) {
> +    static const DBusObjectPathVTable vtable_profile = {
> +        .message_function = profile_handler,
> +    };
> +    const char *object_name;
> +    const char *uuid;
> +
> +    pa_assert(b);
> +
> +    switch(profile) {
> +        case PA_BLUETOOTH_PROFILE_HEADSET_HEAD_UNIT:
> +            object_name = HSP_AG_PROFILE;
> +            uuid = PA_BLUETOOTH_UUID_HSP_AG;
> +            break;
> +        default:
> +            pa_assert_not_reached();
> +            break;
> +    }
> +    pa_assert_se(dbus_connection_register_object_path(pa_dbus_connection_get(b->connection),
> +                  object_name, &vtable_profile, b));
> +    register_profile (b, object_name, uuid);

There doesn't seem to be a way to handle failure when registering the
profile. Should we perhaps be unregistering the object path?

> +}
> +
> +static void profile_done(pa_bluetooth_backend *b, pa_bluetooth_profile_t profile) {
> +    pa_assert(b);
> +
> +    switch(profile) {
> +        case PA_BLUETOOTH_PROFILE_HEADSET_HEAD_UNIT:
> +            dbus_connection_unregister_object_path(pa_dbus_connection_get(b->connection), HSP_AG_PROFILE);
> +            break;
> +        default:
> +            pa_assert_not_reached();
> +            break;
> +    }
> +}
> +
> +pa_bluetooth_backend *pa_bluetooth_backend_new(pa_core *c) {
> +    pa_bluetooth_backend *backend;
> +    DBusError err;
> +
> +    pa_log_debug("Bluetooth Headset Backend API support using the NULL backend");
> +
> +    backend = pa_xnew0(pa_bluetooth_backend, 1);
> +    backend->core = c;
> +
> +    dbus_error_init(&err);
> +    if (!(backend->connection = pa_dbus_bus_get(c, DBUS_BUS_SYSTEM, &err))) {
> +        pa_log("Failed to get D-Bus connection: %s", err.message);
> +        dbus_error_free(&err);
> +        pa_xfree(backend);
> +        return NULL;
> +    }
> +
> +    backend->discovery = pa_shared_get(c, "bluetooth-discovery");
> +
> +    profile_init(backend, PA_BLUETOOTH_PROFILE_HEADSET_HEAD_UNIT);
> +
> +    return backend;
> +}
> +
> +void pa_bluetooth_backend_free(pa_bluetooth_backend *backend) {
> +    pa_assert(backend);
> +
> +    profile_done(backend, PA_BLUETOOTH_PROFILE_HEADSET_HEAD_UNIT);

backend->connection needs to be unref'ed here.

> +
> +    pa_xfree(backend);
> +}
> --
> 1.9.3

Cheers,
Arun


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