[RFC BlueZ 2/2] gatt-dbus: Add remote GATT characteristic objects.

[armansito@chromium.org]

From: Arman Uguray <armansito@chromium.org>

This CL adds remote GATT characteristic objects to the D-Bus API. The
API only exposes the UUID; the characteristic value and permissions have
not yet been implemented.
---
 src/gatt-dbus.c | 165 +++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 164 insertions(+), 1 deletion(-)

diff --git a/src/gatt-dbus.c b/src/gatt-dbus.c
index 60b87fa..db98137 100644
--- a/src/gatt-dbus.c
+++ b/src/gatt-dbus.c
@@ -52,8 +52,24 @@
 
 struct btd_gatt_dbus_service {
 	bt_uuid_t uuid;
+	struct att_range range;
+	GAttrib *attrib;
+	guint attioid;
+	guint request;
+
 	struct btd_device *device;
 	char *path;
+	GSList *characteristics;
+};
+
+struct gatt_dbus_characteristic {
+	bt_uuid_t uuid;
+	uint8_t handle;
+	uint8_t value_handle;
+	uint8_t properties;
+
+	struct btd_gatt_dbus_service *service;
+	char *path;
 };
 
 struct external_app {
@@ -491,19 +507,156 @@ static gboolean service_property_get_uuid(const GDBusPropertyTable *property,
 	return TRUE;
 }
 
+static gboolean characteristic_property_get_uuid(
+		const GDBusPropertyTable *table,
+		DBusMessageIter *iter, void *data)
+{
+	char uuid[MAX_LEN_UUID_STR + 1];
+	const char *ptr = uuid;
+	struct gatt_dbus_characteristic *chr = data;
+
+	bt_uuid_to_string(&chr->uuid, uuid, sizeof(uuid));
+	dbus_message_iter_append_basic(iter, DBUS_TYPE_STRING, &ptr);
+
+	return TRUE;
+}
+
 static const GDBusPropertyTable service_properties[] = {
 	{ "UUID", "s", service_property_get_uuid },
 	{}
 };
 
+static const GDBusPropertyTable characteristic_properties[] = {
+	{ "UUID", "s", characteristic_property_get_uuid },
+	{}
+};
+
+static void unregister_characteristic(gpointer user_data)
+{
+	struct gatt_dbus_characteristic *chr = user_data;
+	g_dbus_unregister_interface(btd_get_dbus_connection(),
+					chr->path, GATT_CHR_IFACE);
+}
+
+static void attio_cleanup(struct btd_gatt_dbus_service *service)
+{
+	if (!service->attrib)
+		return;
+	GAttrib *attrib = service->attrib;
+	service->attrib = NULL;
+	if (service->request) {
+		g_attrib_cancel(attrib, service->request);
+		service->request = 0;
+	}
+	g_attrib_unref(attrib);
+}
+
 static void service_free(gpointer user_data)
 {
 	struct btd_gatt_dbus_service *service = user_data;
 
+	g_slist_free_full(service->characteristics, unregister_characteristic);
+
+	if (service->attioid) {
+		btd_device_remove_attio_callback(service->device,
+						service->attioid);
+	}
+	attio_cleanup(service);
 	g_free(service->path);
 	g_free(service);
 }
 
+static void characteristic_free(gpointer user_data)
+{
+	struct gatt_dbus_characteristic *characteristic = user_data;
+
+	g_free(characteristic->path);
+	g_free(characteristic);
+}
+
+static struct gatt_dbus_characteristic *characteristic_create(
+		struct btd_gatt_dbus_service *service,
+		struct gatt_char *chr)
+{
+	struct gatt_dbus_characteristic *characteristic;
+	bt_uuid_t uuid;
+
+	DBG("GATT characteristic UUID: %s", chr->uuid);
+
+	characteristic = g_try_malloc0(sizeof(struct gatt_dbus_characteristic));
+	if (characteristic == NULL)
+		return NULL;
+
+	characteristic->path = g_strdup_printf("%s/char%04X", service->path,
+						chr->handle);
+	characteristic->service = service;
+	characteristic->handle = chr->handle;
+	characteristic->value_handle = chr->value_handle;
+	characteristic->properties = chr->properties;
+
+	if (bt_string_to_uuid(&uuid, chr->uuid)) {
+		error("Characteristic has invalid UUID: %s", chr->uuid);
+		goto fail;
+	}
+
+	bt_uuid_to_uuid128(&uuid, &characteristic->uuid);
+
+	DBG("Creating GATT characteristic %s", characteristic->path);
+
+	if (g_dbus_register_interface(btd_get_dbus_connection(),
+					characteristic->path,
+					GATT_CHR_IFACE, NULL, NULL,
+					characteristic_properties,
+					characteristic,
+					characteristic_free) == FALSE) {
+		error("Unable to register GATT characteristic: %s", chr->uuid);
+		goto fail;
+	}
+
+	return characteristic;
+
+fail:
+	characteristic_free(characteristic);
+	return NULL;
+}
+
+static void discover_char_cb(uint8_t status, GSList *chars, void *user_data)
+{
+	struct btd_gatt_dbus_service *service = user_data;
+	service->request = 0;
+	if (status) {
+		error("Characteristic discovery failed.");
+		return;
+	}
+	for (; chars; chars = chars->next) {
+		struct gatt_char *chr = chars->data;
+		struct gatt_dbus_characteristic *dbus_chr =
+				characteristic_create(service, chr);
+		if (dbus_chr == NULL)
+			continue;
+		service->characteristics = g_slist_append(
+				service->characteristics, dbus_chr);
+	}
+	attio_cleanup(service);
+}
+
+static void attio_connected_cb(GAttrib *attrib, gpointer user_data)
+{
+	struct btd_gatt_dbus_service *service = user_data;
+	service->attrib = g_attrib_ref(attrib);
+	service->request = gatt_discover_char(service->attrib,
+			service->range.start,
+			service->range.end,
+			NULL, discover_char_cb,
+			service);
+}
+
+static void attio_disconnected_cb(gpointer user_data)
+{
+	struct btd_gatt_dbus_service *service = user_data;
+	attio_cleanup(service);
+}
+
 struct btd_gatt_dbus_service *btd_gatt_dbus_service_create(
 		struct btd_device *device, struct gatt_primary *primary)
 {
@@ -520,6 +673,12 @@ struct btd_gatt_dbus_service *btd_gatt_dbus_service_create(
 	service->path = g_strdup_printf("%s/service%04X", device_path,
 					primary->range.start);
 
+	service->device = device;
+	service->range = primary->range;
+	service->characteristics = NULL;
+	service->attrib = NULL;
+	service->request = 0;
+
 	if (bt_string_to_uuid(&uuid, primary->uuid)) {
 		error("Primary has invalid UUID: %s", primary->uuid);
 		goto fail;
@@ -541,7 +700,11 @@ struct btd_gatt_dbus_service *btd_gatt_dbus_service_create(
 		goto fail;
 	}
 
-	service->device = device;
+	service->attioid = service->attioid = btd_device_add_attio_callback(
+			service->device,
+			attio_connected_cb,
+			attio_disconnected_cb, service);
+
 	return service;
 
 fail:
-- 
1.8.3.2