bluez 5: Load the native headset backend if the oFono one is unavailable

This implements some autodetect if both headset backends are compiled in:
First we try to contact the oFono service, if that's not working,
then we start the native backend instead.

Likewise if the oFono service is going offline/online, we load/unload
the native backend accordingly.

Signed-off-by: David Henningsson <david.henningsson@canonical.com>

src/modules/bluetooth/backend-ofono.c

@@ -336,6 +336,16 @@ static void hf_audio_agent_get_cards(pa_bluetooth_backend *hf) {
     hf_dbus_send_and_add_to_pending(hf, m, hf_audio_agent_get_cards_reply, NULL);
 }
 
+static void ofono_bus_id_destroy(pa_bluetooth_backend *backend) {
+    pa_hashmap_remove_all(backend->cards);
+
+    if (backend->ofono_bus_id) {
+        pa_xfree(backend->ofono_bus_id);
+        backend->ofono_bus_id = NULL;
+        pa_bluetooth_discovery_set_ofono_running(backend->discovery, false);
+    }
+}
+
 static void hf_audio_agent_register_reply(DBusPendingCall *pending, void *userdata) {
     DBusMessage *r;
     pa_dbus_pending *p;
@@ -360,6 +370,8 @@ finish:
 
     PA_LLIST_REMOVE(pa_dbus_pending, backend->pending, p);
     pa_dbus_pending_free(p);
+
+    pa_bluetooth_discovery_set_ofono_running(backend->discovery, backend->ofono_bus_id != NULL);
 }
 
 static void hf_audio_agent_register(pa_bluetooth_backend *hf) {
@@ -393,8 +405,7 @@ static void hf_audio_agent_unregister(pa_bluetooth_backend *backend) {
         pa_assert_se(dbus_message_append_args(m, DBUS_TYPE_OBJECT_PATH, &path, DBUS_TYPE_INVALID));
         pa_assert_se(dbus_connection_send(pa_dbus_connection_get(backend->connection), m, NULL));
 
-        pa_xfree(backend->ofono_bus_id);
+        ofono_bus_id_destroy(backend);
-        backend->ofono_bus_id = NULL;
     }
 }
 
@@ -429,11 +440,7 @@ static DBusHandlerResult filter_cb(DBusConnection *bus, DBusMessage *m, void *da
 
             if (old_owner && *old_owner) {
                 pa_log_debug("oFono disappeared");
-
+                ofono_bus_id_destroy(backend);
-                pa_hashmap_remove_all(backend->cards);
-
-                pa_xfree(backend->ofono_bus_id);
-                backend->ofono_bus_id = NULL;
             }
 
             if (new_owner && *new_owner) {
@@ -490,10 +497,7 @@ static DBusMessage *hf_audio_agent_release(DBusConnection *c, DBusMessage *m, vo
 
     pa_log_debug("HF audio agent has been unregistered by oFono (%s)", backend->ofono_bus_id);
 
-    pa_hashmap_remove_all(backend->cards);
+    ofono_bus_id_destroy(backend);
-
-    pa_xfree(backend->ofono_bus_id);
-    backend->ofono_bus_id = NULL;
 
     pa_assert_se(r = dbus_message_new_method_return(m));
 

src/modules/bluetooth/bluez5-util.c

@@ -861,6 +861,18 @@ static void parse_interfaces_and_properties(pa_bluetooth_discovery *y, DBusMessa
     return;
 }
 
+void pa_bluetooth_discovery_set_ofono_running(pa_bluetooth_discovery *y, bool is_running) {
+    pa_assert(y);
+
+    pa_log_debug("oFono is running: %s", pa_yes_no(is_running));
+    if (is_running && y->native_backend) {
+        pa_bluetooth_native_backend_free(y->native_backend);
+        y->native_backend = NULL;
+    }
+    else if (!is_running && !y->native_backend)
+        y->native_backend = pa_bluetooth_native_backend_new(y->core, y);
+}
+
 static void get_managed_objects_reply(DBusPendingCall *pending, void *userdata) {
     pa_dbus_pending *p;
     pa_bluetooth_discovery *y;

src/modules/bluetooth/bluez5-util.h

@@ -157,4 +157,5 @@ const char *pa_bluetooth_profile_to_string(pa_bluetooth_profile_t profile);
 pa_bluetooth_discovery* pa_bluetooth_discovery_get(pa_core *core);
 pa_bluetooth_discovery* pa_bluetooth_discovery_ref(pa_bluetooth_discovery *y);
 void pa_bluetooth_discovery_unref(pa_bluetooth_discovery *y);
+void pa_bluetooth_discovery_set_ofono_running(pa_bluetooth_discovery *y, bool is_running);
 #endif