gatt: Add Write Request handling for GDBusProxy

When the characteristic requires Write Request, the ATT response should
be sent after receiving the reply for the Set method call.

diff --git a/src/gatt-dbus.c b/src/gatt-dbus.c
index 9ab7b8b..1a1c6cc 100644 (file)
--- a/src/gatt-dbus.c
+++ b/src/gatt-dbus.c
@@ -56,6 +56,11 @@ struct external_app {
        unsigned int watch;
 };
 
+struct proxy_write_data {
+       btd_attr_write_result_t result_cb;
+       void *user_data;
+};
+
 /*
  * Attribute to Proxy hash table. Used to map incoming
  * ATT operations to its external characteristic proxy.
@@ -181,8 +186,30 @@ static void proxy_read_cb(struct btd_attribute *attr,
 
 static void proxy_write_reply(const DBusError *derr, void *user_data)
 {
-       if (derr)
-               DBG("Write reply: %s", derr->message);
+       struct proxy_write_data *wdata = user_data;
+       int err = 0;
+
+       /*
+        * Security requirements shall be handled by the core. If external
+        * applications returns an error, the reasons will be restricted to
+        * invalid argument or application specific errors.
+        */
+
+       if (!dbus_error_is_set(derr))
+               goto done;
+
+       DBG("Write reply: %s", derr->message);
+
+       if (dbus_error_has_name(derr, DBUS_ERROR_NO_REPLY))
+               err = -ETIMEDOUT;
+       else if (dbus_error_has_name(derr, ERROR_INTERFACE ".InvalidArguments"))
+               err = -EINVAL;
+       else
+               err = -EPROTO;
+
+done:
+       if (wdata && wdata->result_cb)
+               wdata->result_cb(err, wdata->user_data);
 }
 
 static void proxy_write_cb(struct btd_attribute *attr,
@@ -193,16 +220,44 @@ static void proxy_write_cb(struct btd_attribute *attr,
        GDBusProxy *proxy;
 
        proxy = g_hash_table_lookup(proxy_hash, attr);
-       if (!proxy)
-               /* FIXME: Attribute not found */
+       if (!proxy) {
+               result(-ENOENT, user_data);
                return;
+       }
 
-       g_dbus_proxy_set_property_array(proxy, "Value", DBUS_TYPE_BYTE,
+       /*
+        * "result" callback defines if the core wants to receive the
+        * operation result, allowing to select ATT Write Request or Write
+        * Command. Descriptors requires Write Request operation. For
+        * Characteristics, the implementation will define which operations
+        * are allowed based on the properties/flags.
+        * TODO: Write Long Characteristics/Descriptors.
+        */
+
+       if (result) {
+               struct proxy_write_data *wdata;
+
+               wdata = g_new0(struct proxy_write_data, 1);
+               wdata->result_cb = result;
+               wdata->user_data = user_data;
+
+               g_dbus_proxy_set_property_array(proxy, "Value", DBUS_TYPE_BYTE,
+                                               value, len, proxy_write_reply,
+                                               wdata, g_free);
+       } else {
+               /*
+                * Caller is not interested in the Set method call result.
+                * This flow implements the ATT Write Command scenario, where
+                * the remote doesn't receive ATT response.
+                */
+               g_dbus_proxy_set_property_array(proxy, "Value", DBUS_TYPE_BYTE,
                                                value, len, proxy_write_reply,
                                                NULL, NULL);
+       }
 
-       DBG("Server: Write characteristic callback %s",
+       DBG("Server: Write attribute callback %s",
                                        g_dbus_proxy_get_path(proxy));
+
 }
 
 static int register_external_service(const struct external_app *eapp,