diff --git a/src/shared/gatt-server.c b/src/shared/gatt-server.c
index 4c492d5..4d9d92f 100644
--- a/src/shared/gatt-server.c
+++ b/src/shared/gatt-server.c
#define MAX(a, b) ((a) > (b) ? (a) : (b))
#endif
+#ifndef MIN
+#define MIN(a, b) ((a) < (b) ? (a) : (b))
+#endif
+
struct bt_gatt_server {
struct gatt_db *db;
struct bt_att *att;
int ref_count;
uint16_t mtu;
+ unsigned int mtu_id;
+
bt_gatt_server_debug_func_t debug_callback;
bt_gatt_server_destroy_func_t debug_destroy;
void *debug_data;
};
-static bool gatt_server_register_att_handlers(struct bt_gatt_server *server)
-{
- /* TODO */
- return true;
-}
-
static void bt_gatt_server_free(struct bt_gatt_server *server)
{
if (server->debug_destroy)
server->debug_destroy(server->debug_data);
+ bt_att_unregister(server->att, server->mtu_id);
bt_att_unref(server->att);
free(server);
}
+static void encode_error_rsp(uint8_t opcode, uint16_t handle, uint8_t ecode,
+ uint8_t pdu[4])
+{
+ pdu[0] = opcode;
+ pdu[3] = ecode;
+ put_le16(handle, pdu + 1);
+}
+
+static void exchange_mtu_cb(uint8_t opcode, const void *pdu,
+ uint16_t length, void *user_data)
+{
+ struct bt_gatt_server *server = user_data;
+ uint16_t client_rx_mtu;
+ uint16_t final_mtu;
+ uint8_t rsp_pdu[4];
+
+ if (length != 2) {
+ encode_error_rsp(opcode, 0, BT_ATT_ERROR_INVALID_PDU, rsp_pdu);
+ bt_att_send(server->att, BT_ATT_OP_ERROR_RSP, rsp_pdu,
+ sizeof(rsp_pdu), NULL, NULL, NULL);
+ return;
+ }
+
+ client_rx_mtu = get_le16(pdu);
+ final_mtu = MAX(MIN(client_rx_mtu, server->mtu), BT_ATT_DEFAULT_LE_MTU);
+
+ /* Respond with the server MTU */
+ put_le16(server->mtu, rsp_pdu);
+ bt_att_send(server->att, BT_ATT_OP_MTU_RSP, rsp_pdu, 2, NULL, NULL,
+ NULL);
+
+ /* Set MTU to be the minimum */
+ server->mtu = final_mtu;
+ bt_att_set_mtu(server->att, final_mtu);
+}
+
+static bool gatt_server_register_att_handlers(struct bt_gatt_server *server)
+{
+ /* EXCHANGE MTU request */
+ server->mtu_id = bt_att_register(server->att, BT_ATT_OP_MTU_REQ,
+ exchange_mtu_cb,
+ server, NULL);
+ if (!server->mtu_id)
+ return false;
+
+ return true;
+}
+
struct bt_gatt_server *bt_gatt_server_new(struct gatt_db *db,
struct bt_att *att, uint16_t mtu)
{