tools: Add reading Value property of gatt-service

This patch extends the gatt-service.c example adding the callback to
allow reading the Value property. At the moment, it is a generic
callback and it doesn't consider characteristic value property
restrictions.

diff --git a/tools/gatt-service.c b/tools/gatt-service.c
index 56d6e86..a5a64b5 100644 (file)
--- a/tools/gatt-service.c
+++ b/tools/gatt-service.c
@@ -46,18 +46,44 @@
 static GMainLoop *main_loop;
 static GSList *services;
 
+struct characteristic {
+       char *uuid;
+       uint8_t *value;
+       int vlen;
+};
+
 static gboolean chr_get_uuid(const GDBusPropertyTable *property,
                                        DBusMessageIter *iter, void *user_data)
 {
-       const char *uuid = user_data;
+       struct characteristic *chr = user_data;
 
-       dbus_message_iter_append_basic(iter, DBUS_TYPE_STRING, &uuid);
+       dbus_message_iter_append_basic(iter, DBUS_TYPE_STRING, &chr->uuid);
+
+       return TRUE;
+}
+
+static gboolean chr_get_value(const GDBusPropertyTable *property,
+                                       DBusMessageIter *iter, void *user_data)
+{
+       struct characteristic *chr = user_data;
+       DBusMessageIter array;
+
+       printf("Get(\"Value\")\n");
+
+       dbus_message_iter_open_container(iter, DBUS_TYPE_ARRAY,
+                                       DBUS_TYPE_BYTE_AS_STRING, &array);
+
+       dbus_message_iter_append_fixed_array(&array, DBUS_TYPE_BYTE,
+                                               &chr->value, chr->vlen);
+
+       dbus_message_iter_close_container(iter, &array);
 
        return TRUE;
 }
 
 static const GDBusPropertyTable chr_properties[] = {
        { "UUID",       "s",    chr_get_uuid },
+       { "Value", "ay", chr_get_value, NULL, NULL },
        { }
 };
 
@@ -100,18 +126,35 @@ static const GDBusPropertyTable service_properties[] = {
        { }
 };
 
+static void chr_iface_destroy(gpointer user_data)
+{
+       struct characteristic *chr = user_data;
+
+       g_free(chr->uuid);
+       g_free(chr->value);
+       g_free(chr);
+}
+
 static gboolean register_characteristic(DBusConnection *conn, const char *uuid,
+                                               const uint8_t *value, int vlen,
                                                const char *service_path)
 {
+       struct characteristic *chr;
        static int id = 1;
        char *path;
        gboolean ret = TRUE;
 
        path = g_strdup_printf("%s/characteristic%d", service_path, id++);
 
+       chr = g_new0(struct characteristic, 1);
+
+       chr->uuid = g_strdup(uuid);
+       chr->value = g_memdup(value, vlen);
+       chr->vlen = vlen;
+
        if (!g_dbus_register_interface(conn, path, GATT_CHR_IFACE,
                                        NULL, NULL, chr_properties,
-                                       g_strdup(uuid), g_free)) {
+                                       chr, chr_iface_destroy)) {
                printf("Couldn't register characteristic interface\n");
                ret = FALSE;
        }
@@ -141,14 +184,18 @@ static char *register_service(DBusConnection *conn, const char *uuid)
 static void create_services(DBusConnection *conn)
 {
        char *service_path;
+       uint8_t level = 0;
 
        service_path = register_service(conn, IAS_UUID);
        if (!service_path)
                return;
 
-       /* Add Alert Level Characteristic to Immediate Alert Service */
-       if (!register_characteristic(conn, ALERT_LEVEL_CHR_UUID,
-                                                       service_path)) {
+       /* Add Alert Level Characteristic to Immediate Alert Service
+        * According to the IAS SPEC, reading <<Alert level>> is not allowed.
+        * "Value" is readable for testing purpose only.
+        */
+       if (!register_characteristic(conn, ALERT_LEVEL_CHR_UUID, &level,
+                                               sizeof(level), service_path)) {
                printf("Couldn't register Alert Level characteristic (IAS)\n");
                g_dbus_unregister_interface(conn, service_path,
                                                        GATT_SERVICE_IFACE);