sm: send/receive keypress notifications

src/ble/sm.c

@@ -254,6 +254,7 @@ typedef struct sm_setup_context {
 
     // user response, (Phase 1 and/or 2)
     uint8_t   sm_user_response;
+    uint8_t   sm_keypress_notification;
 
     // defines which keys will be send after connection is encrypted - calculated during Phase 1, used Phase 3
     int       sm_key_distribution_send_set;
@@ -1104,6 +1105,7 @@ static void sm_init_setup(sm_connection_t * sm_conn){
 
     // fill in sm setup
     setup->sm_state_vars = 0;
+    setup->sm_keypress_notification = 0xff;
     sm_reset_tk();
     setup->sm_peer_addr_type = sm_conn->sm_peer_addr_type;
     memcpy(setup->sm_peer_address, sm_conn->sm_peer_address, 6);
@@ -1946,6 +1948,15 @@ static void sm_run(void){
         sm_connection_t * connection = sm_get_connection_for_handle(sm_active_connection);
         if (!connection) return;
 
+        // send keypress notifications
+        if (setup->sm_keypress_notification != 0xff){
+            uint8_t buffer[2];
+            buffer[0] = SM_CODE_KEYPRESS_NOTIFICATION;
+            buffer[1] = setup->sm_keypress_notification;
+            setup->sm_keypress_notification = 0xff;
+            l2cap_send_connectionless(connection->sm_handle, L2CAP_CID_SECURITY_MANAGER_PROTOCOL, (uint8_t*) buffer, sizeof(buffer));
+        }
+
         sm_key_t plaintext;
         int key_distribution_flags;
 
@@ -2994,6 +3005,16 @@ static void sm_pdu_handler(uint8_t packet_type, hci_con_handle_t con_handle, uin
 
     int err;
 
+    if (packet[0] == SM_CODE_KEYPRESS_NOTIFICATION){
+        uint8_t buffer[5];
+        buffer[0] = SM_EVENT_KEYPRESS_NOTIFICATION;
+        buffer[1] = 3;
+        little_endian_store_16(buffer, 2, con_handle);
+        buffer[4] = packet[1];
+        sm_dispatch_event(HCI_EVENT_PACKET, 0, buffer, sizeof(buffer));
+        return;
+    }
+
     switch (sm_conn->sm_engine_state){
         
         // a sm timeout requries a new physical connection
@@ -3652,6 +3673,14 @@ void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey){
     sm_run();
 }
 
+void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action){
+    sm_connection_t * sm_conn = sm_get_connection_for_handle(con_handle);
+    if (!sm_conn) return;     // wrong connection
+    if (action > SM_KEYPRESS_PASSKEY_ENTRY_COMPLETED) return;
+    setup->sm_keypress_notification = action;
+    sm_run();
+}
+
 /**
  * @brief Identify device in LE Device DB
  * @param handle

src/ble/sm.h

@@ -189,6 +189,13 @@ void sm_numeric_comparison_confirm(hci_con_handle_t con_handle);
  */
 void sm_passkey_input(hci_con_handle_t con_handle, uint32_t passkey);
 
+/**
+ * @brief Send keypress notification for keyboard only devices
+ * @param con_handle
+ * @param action see SM_KEYPRESS_* in bluetooth.h
+ */
+void sm_keypress_notification(hci_con_handle_t con_handle, uint8_t action);
+
 /**
  *
  * @brief Get encryption key size.

src/btstack_defines.h

@@ -793,6 +793,14 @@ typedef uint8_t sm_key_t[16];
   */
 #define SM_EVENT_AUTHORIZATION_RESULT                            0xDC
 
+ /**
+  * @format H1
+  * @param handle
+  * @param action see SM_KEYPRESS_*
+  */
+#define SM_EVENT_KEYPRESS_NOTIFICATION                           0xDD
+
+
 // GAP
 
 /**

src/btstack_event.h

@@ -2417,6 +2417,27 @@ static inline uint8_t sm_event_authorization_result_get_authorization_result(con
 }
 #endif
 
+#ifdef ENABLE_BLE
+/**
+ * @brief Get field handle from event SM_EVENT_KEYPRESS_NOTIFICATION
+ * @param event packet
+ * @return handle
+ * @note: btstack_type H
+ */
+static inline hci_con_handle_t sm_event_keypress_notification_get_handle(const uint8_t * event){
+    return little_endian_read_16(event, 2);
+}
+/**
+ * @brief Get field action from event SM_EVENT_KEYPRESS_NOTIFICATION
+ * @param event packet
+ * @return action
+ * @note: btstack_type 1
+ */
+static inline uint8_t sm_event_keypress_notification_get_action(const uint8_t * event){
+    return event[4];
+}
+#endif
+
 /**
  * @brief Get field handle from event GAP_EVENT_SECURITY_LEVEL
  * @param event packet