bluetooth: Abstract transport access types inside bluetooth-util

Transports can be acquired with different access rights, but in practice
"rw" was always used inside module-bluetooth-device. In addition, this
feature is removed in BlueZ 5.0 and therefore it is convenient to
abstract all this inside bluetooth-util.

src/modules/bluetooth/bluetooth-util.c

@@ -1087,7 +1087,8 @@ bool pa_bluetooth_device_any_audio_connected(const pa_bluetooth_device *d) {
         d->profile_state[PROFILE_HFGW] >= PA_BT_AUDIO_STATE_CONNECTED;
 }
 
-int pa_bluetooth_transport_acquire(pa_bluetooth_transport *t, const char *accesstype, size_t *imtu, size_t *omtu) {
+int pa_bluetooth_transport_acquire(pa_bluetooth_transport *t, bool optional, size_t *imtu, size_t *omtu) {
+    const char *accesstype = "rw";
     DBusMessage *m, *r;
     DBusError err;
     int ret;
@@ -1097,6 +1098,20 @@ int pa_bluetooth_transport_acquire(pa_bluetooth_transport *t, const char *access
     pa_assert(t->device);
     pa_assert(t->device->discovery);
 
+    if (optional) {
+        /* FIXME: we are trying to acquire the transport only if the stream is
+           playing, without actually initiating the stream request from our side
+           (which is typically undesireable specially for hfgw use-cases.
+           However this approach is racy, since the stream could have been
+           suspended in the meantime, so we can't really guarantee that the
+           stream will not be requested until BlueZ's API supports this
+           atomically. */
+        if (t->state < PA_BLUETOOTH_TRANSPORT_STATE_PLAYING) {
+            pa_log_info("Failed optional acquire of transport %s", t->path);
+            return -1;
+        }
+    }
+
     dbus_error_init(&err);
 
     pa_assert_se(m = dbus_message_new_method_call(t->owner, t->path, "org.bluez.MediaTransport", "Acquire"));
@@ -1126,7 +1141,8 @@ fail:
     return ret;
 }
 
-void pa_bluetooth_transport_release(pa_bluetooth_transport *t, const char *accesstype) {
+void pa_bluetooth_transport_release(pa_bluetooth_transport *t) {
+    const char *accesstype = "rw";
     DBusMessage *m;
     DBusError err;
 

src/modules/bluetooth/bluetooth-util.h

@@ -148,8 +148,8 @@ pa_bluetooth_device* pa_bluetooth_discovery_get_by_address(pa_bluetooth_discover
 
 bool pa_bluetooth_device_any_audio_connected(const pa_bluetooth_device *d);
 
-int pa_bluetooth_transport_acquire(pa_bluetooth_transport *t, const char *accesstype, size_t *imtu, size_t *omtu);
+int pa_bluetooth_transport_acquire(pa_bluetooth_transport *t, bool optional, size_t *imtu, size_t *omtu);
-void pa_bluetooth_transport_release(pa_bluetooth_transport *t, const char *accesstype);
+void pa_bluetooth_transport_release(pa_bluetooth_transport *t);
 
 void pa_bluetooth_transport_set_microphone_gain(pa_bluetooth_transport *t, uint16_t value);
 void pa_bluetooth_transport_set_speaker_gain(pa_bluetooth_transport *t, uint16_t value);

src/modules/bluetooth/module-bluetooth-device.c

@@ -141,7 +141,7 @@ struct userdata {
     char *address;
     char *path;
     pa_bluetooth_transport *transport;
-    char *accesstype;
+    bool transport_acquired;
     pa_hook_slot *discovery_slot;
     pa_hook_slot *sink_state_changed_slot;
     pa_hook_slot *source_state_changed_slot;
@@ -322,7 +322,7 @@ static void setup_stream(struct userdata *u) {
 }
 
 static bool bt_transport_is_acquired(struct userdata *u) {
-    if (u->accesstype == NULL) {
+    if (!u->transport_acquired) {
         pa_assert(u->stream_fd < 0);
         return FALSE;
     } else {
@@ -359,17 +359,14 @@ static void bt_transport_release(struct userdata *u) {
 
     pa_log_debug("Releasing transport %s", u->transport->path);
 
-    pa_bluetooth_transport_release(u->transport, u->accesstype);
+    pa_bluetooth_transport_release(u->transport);
 
-    pa_xfree(u->accesstype);
+    u->transport_acquired = false;
-    u->accesstype = NULL;
 
     teardown_stream(u);
 }
 
 static int bt_transport_acquire(struct userdata *u, pa_bool_t start) {
-    const char *accesstype = "rw";
-
     pa_assert(u->transport);
 
     if (bt_transport_is_acquired(u)) {
@@ -380,21 +377,7 @@ static int bt_transport_acquire(struct userdata *u, pa_bool_t start) {
 
     pa_log_debug("Acquiring transport %s", u->transport->path);
 
-    if (!start) {
+    u->stream_fd = pa_bluetooth_transport_acquire(u->transport, !start, &u->read_link_mtu, &u->write_link_mtu);
-        /* FIXME: we are trying to acquire the transport only if the stream is
-           playing, without actually initiating the stream request from our side
-           (which is typically undesireable specially for hfgw use-cases.
-           However this approach is racy, since the stream could have been
-           suspended in the meantime, so we can't really guarantee that the
-           stream will not be requested until BlueZ's API supports this
-           atomically. */
-        if (u->device->profile_state[u->profile] < PA_BT_AUDIO_STATE_PLAYING) {
-            pa_log_info("Failed optional acquire of transport %s", u->transport->path);
-            return -1;
-        }
-    }
-
-    u->stream_fd = pa_bluetooth_transport_acquire(u->transport, accesstype, &u->read_link_mtu, &u->write_link_mtu);
     if (u->stream_fd < 0) {
         if (start)
             pa_log("Failed to acquire transport %s", u->transport->path);
@@ -404,7 +387,7 @@ static int bt_transport_acquire(struct userdata *u, pa_bool_t start) {
         return -1;
     }
 
-    u->accesstype = pa_xstrdup(accesstype);
+    u->transport_acquired = true;
     pa_log_info("Transport %s acquired: fd %d", u->transport->path, u->stream_fd);
 
     if (!start)