This patch adds support for adding a CCC descriptor entry for an
external characteristic, if it has the 'notify' or 'indicate' property.
When the CCC descriptor is written to, bluetoothd calls the
'StartNotify' and 'StopNotify' methods on the characteristic in a
reference counted manner.
---
src/gatt-manager.c | 106 ++++++++++++++++++++++++++++++++++++++++++++++++++---
1 file changed, 100 insertions(+), 6 deletions(-)
diff --git a/src/gatt-manager.c b/src/gatt-manager.c
index 9e09894..4353f38 100644
--- a/src/gatt-manager.c
+++ b/src/gatt-manager.c
@@ -76,7 +76,9 @@ struct external_chrc {
uint8_t props;
uint8_t ext_props;
struct gatt_db_attribute *attrib;
+ struct gatt_db_attribute *ccc;
struct queue *pending_ops;
+ unsigned int ntfy_cnt;
};
struct pending_dbus_op {
@@ -373,10 +375,14 @@ static void proxy_added_cb(GDBusProxy *proxy, void *user_data)
return;
}
- /*
- * TODO: Determine descriptors count to add based on special
- * characteristic properties (e.g. extended properties).
- */
+ if ((chrc->props & BT_GATT_CHRC_PROP_NOTIFY ||
+ chrc->props & BT_GATT_CHRC_PROP_INDICATE) &&
+ !incr_attr_count(service, 1)) {
+ error("Failed to increment attribute count for CCC");
+ service->failed = true;
+ return;
+ }
+
queue_push_tail(service->chrcs, chrc);
} else
@@ -664,6 +670,87 @@ static uint32_t permissions_from_props(uint8_t props, uint8_t ext_props)
return perm;
}
+static uint8_t ccc_write_cb(uint16_t value, void *user_data)
+{
+ struct external_chrc *chrc = user_data;
+
+ DBG("External CCC write received with value: 0x%04x", value);
+
+ /* Notifications/indications disabled */
+ if (!value) {
+ if (!chrc->ntfy_cnt)
+ return 0;
+
+ if (__sync_sub_and_fetch(&chrc->ntfy_cnt, 1))
+ return 0;
+
+ /*
+ * Send request to stop notifying. This is best-effort
+ * operation, so simply ignore the return the value.
+ */
+ g_dbus_proxy_method_call(chrc->proxy, "StopNotify", NULL,
+ NULL, NULL, NULL);
+ return 0;
+ }
+
+ /*
+ * TODO: All of the errors below should fall into the so called
+ * "Application Error" range. Since there is no well defined error for
+ * these, we return a generic ATT protocol error for now.
+ */
+
+ if (chrc->ntfy_cnt == UINT_MAX) {
+ /* Maximum number of per-device CCC descriptors configured */
+ return BT_ATT_ERROR_REQUEST_NOT_SUPPORTED;
+ }
+
+ /* Don't support undefined CCC values yet */
+ if (value > 2 ||
+ (value == 1 && !(chrc->props & BT_GATT_CHRC_PROP_NOTIFY)) ||
+ (value == 2 && !(chrc->props & BT_GATT_CHRC_PROP_INDICATE)))
+ return BT_ATT_ERROR_REQUEST_NOT_SUPPORTED;
+
+ /*
+ * Always call StartNotify for an incoming enable and ignore the return
+ * value for now.
+ */
+ if (g_dbus_proxy_method_call(chrc->proxy,
+ "StartNotify", NULL, NULL,
+ NULL, NULL) == FALSE)
+ return BT_ATT_ERROR_REQUEST_NOT_SUPPORTED;
+
+ __sync_fetch_and_add(&chrc->ntfy_cnt, 1);
+
+ return 0;
+}
+
+static bool create_ccc_entry(struct external_service *service,
+ struct external_chrc *chrc)
+{
+ uint16_t svc_start;
+ struct btd_gatt_database *database;
+
+ if (!gatt_db_attribute_get_service_handles(service->attrib, &svc_start,
+ NULL)) {
+ error("Failed to obtain service handle");
+ return false;
+ }
+
+ database = btd_adapter_get_database(service->manager->adapter);
+ if (!database)
+ return false;
+
+ chrc->ccc = btd_gatt_database_add_ccc(database, svc_start,
+ ccc_write_cb,
+ chrc, NULL);
+ if (!chrc->ccc) {
+ error("Failed to create CCC entry for characteristic");
+ return false;
+ }
+
+ return true;
+}
+
static bool create_chrc_entry(struct external_service *service,
struct external_chrc *chrc)
{
@@ -691,9 +778,16 @@ static bool create_chrc_entry(struct external_service *service,
chrc->props, chrc_read_cb,
chrc_write_cb, chrc);
- /* TODO: Create descriptor entries */
+ if (!chrc->attrib) {
+ error("Failed to create characteristic entry in database");
+ return false;
+ }
+
+ if (chrc->props & BT_GATT_CHRC_PROP_NOTIFY ||
+ chrc->props & BT_GATT_CHRC_PROP_INDICATE)
+ return create_ccc_entry(service, chrc);
- return !!chrc->attrib;
+ return true;
}
static bool create_service_entry(struct external_service *service)
--
2.2.0.rc0.207.ga3a616c
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