From 1c00af99f761cde21b084cb0cfea04265274259e Mon Sep 17 00:00:00 2001
From: Matthias Ringwald <matthias@ringwald.ch>
Date: Fri, 3 Apr 2015 21:58:10 +0200
Subject: [PATCH] emit event for ATT MTU size

---
 ble/att_server.c           | 21 +++++++++++++++++++++
 include/btstack/hci_cmds.h | 11 +++++++++--
 2 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/ble/att_server.c b/ble/att_server.c
index d1fdb3724..cd144649b 100644
--- a/ble/att_server.c
+++ b/ble/att_server.c
@@ -104,6 +104,21 @@ static void att_handle_value_indication_notify_client(uint8_t status, uint16_t c
     (*att_client_packet_handler)(HCI_EVENT_PACKET, 0, &event[0], sizeof(event));
 }
 
+static void att_emit_mtu_event(uint16_t handle, uin16_t mtu){
+
+    if (!att_client_packet_handler) return;
+
+    uint8_t event[5];
+    int pos = 0;
+    event[pos++] = ATT_MTU_EXCHANGE_COMPLETE;
+    event[pos++] = sizeof(event) - 2;
+    bt_store_16(event, pos, handle);
+    pos += 2;
+    bt_store_16(event, pos, mtu);
+    pos += 2;
+    (*att_client_packet_handler)(HCI_EVENT_PACKET, 0, &event[0], sizeof(event));
+}
+
 static void att_handle_value_indication_timeout(timer_source_t *ts){
     uint16_t att_handle = att_handle_value_indication_handle;
     att_handle_value_indication_notify_client(ATT_HANDLE_VALUE_INDICATION_TIMEOUT, att_connection.con_handle, att_handle);
@@ -289,6 +304,12 @@ static void att_run(void){
             }
 
             l2cap_send_prepared_connectionless(att_connection.con_handle, L2CAP_CID_ATTRIBUTE_PROTOCOL, att_response_size);
+
+            // notify client about MTU exchange result
+            if (att_response_buffer[0] == ATT_EXCHANGE_MTU_RESPONSE){
+                att_emit_mtu_event(att_connection.con_handle, att_connection.mtu);
+            }
+
             break;
     }
 }
diff --git a/include/btstack/hci_cmds.h b/include/btstack/hci_cmds.h
index c0ab6cf6c..9ad4fb1b8 100644
--- a/include/btstack/hci_cmds.h
+++ b/include/btstack/hci_cmds.h
@@ -534,9 +534,16 @@ extern "C" {
 
 #define GATT_CHARACTERISTIC_DESCRIPTOR_QUERY_RESULT        0xA9
 #define GATT_LONG_CHARACTERISTIC_DESCRIPTOR_QUERY_RESULT   0xAA
-    
+
+/** 
+ * @format H2
+ * @param handle
+ * @param MTU
+ */    
+#define ATT_MTU_EXCHANGE_COMPLETE						   0xB5
+
 // data: event(8), len(8), status (8), hci_handle (16), attribute_handle (16)
-#define ATT_HANDLE_VALUE_INDICATION_COMPLETE                 0xB6
+#define ATT_HANDLE_VALUE_INDICATION_COMPLETE               0xB6
 
 
 // data: event(8), len(8), status (8), bnep service uuid (16)