gatt: Add function to create constant attributes

This patch adds a helper function to create attribute with static
values. It is intended to be used to create GATT services, and
characteristic declarations.

diff --git a/src/gatt.c b/src/gatt.c
index f7b74d6..d3a8062 100644 (file)
--- a/src/gatt.c
+++ b/src/gatt.c
@@ -30,6 +30,7 @@
 #include "log.h"
 #include "lib/uuid.h"
 #include "attrib/att.h"
+#include "src/shared/util.h"
 
 #include "gatt-dbus.h"
 #include "gatt.h"
@@ -48,6 +49,39 @@ struct btd_attribute {
 static GList *local_attribute_db;
 static uint16_t next_handle = 0x0001;
 
+static inline void put_uuid_le(const bt_uuid_t *src, void *dst)
+{
+       if (src->type == BT_UUID16)
+               put_le16(src->value.u16, dst);
+       else if (src->type == BT_UUID32)
+               put_le32(src->value.u32, dst);
+       else
+               /* Convert from 128-bit BE to LE */
+               bswap_128(&src->value.u128, dst);
+}
+
+/*
+ * Helper function to create new attributes containing constant/static values.
+ * eg: declaration of services/characteristics, and characteristics with
+ * fixed values.
+ */
+static struct btd_attribute *new_const_attribute(const bt_uuid_t *type,
+                                                       const uint8_t *value,
+                                                       uint16_t len)
+{
+       struct btd_attribute *attr;
+
+       attr = malloc0(sizeof(struct btd_attribute) + len);
+       if (attr == NULL)
+               return NULL;
+
+       attr->type = *type;
+       memcpy(&attr->value, value, len);
+       attr->value_len = len;
+
+       return attr;
+}
+
 static int local_database_add(uint16_t handle, struct btd_attribute *attr)
 {
        attr->handle = handle;
@@ -59,9 +93,9 @@ static int local_database_add(uint16_t handle, struct btd_attribute *attr)
 
 struct btd_attribute *btd_gatt_add_service(const bt_uuid_t *uuid)
 {
+       struct btd_attribute *attr;
        uint16_t len = bt_uuid_len(uuid);
-       struct btd_attribute *attr = g_malloc0(sizeof(struct btd_attribute) +
-                                                                       len);
+       uint8_t value[len];
 
        /*
         * Service DECLARATION
@@ -75,13 +109,15 @@ struct btd_attribute *btd_gatt_add_service(const bt_uuid_t *uuid)
         * (2) - 2 or 16 octets: Service UUID
         */
 
-       attr->type = primary_uuid;
+       /* Set attribute value */
+       put_uuid_le(uuid, value);
 
-       att_put_uuid(*uuid, attr->value);
-       attr->value_len = len;
+       attr = new_const_attribute(&primary_uuid, value, len);
+       if (attr == NULL)
+               return NULL;
 
        if (local_database_add(next_handle, attr) < 0) {
-               g_free(attr);
+               free(attr);
                return NULL;
        }