feat(ble/bluedroid): Support LE Security Levels Characteristic

components/bt/host/bluedroid/Kconfig.in

@@ -377,6 +377,13 @@ config BT_GATTS_APPEARANCE_WRITABLE
     help
         Enabling this option allows remote GATT clients to write appearance
 
+config BT_GATTS_SECURITY_LEVELS_CHAR
+    bool "Enable LE GATT Security Levels Characteristic"
+    depends on BT_GATTS_ENABLE
+    default n
+    help
+        Enable LE GATT Security Levels Characteristic
+
 menuconfig BT_GATTC_ENABLE
     bool "Include GATT client module(GATTC)"
     depends on BT_BLE_ENABLED

components/bt/host/bluedroid/common/include/common/bluedroid_user_config.h

@@ -580,6 +580,12 @@
 #define UC_BT_GATTS_APPEARANCE_WRITABLE         FALSE
 #endif
 
+#ifdef CONFIG_BT_GATTS_SECURITY_LEVELS_CHAR
+#define UC_BT_GATTS_SECURITY_LEVELS_CHAR         CONFIG_BT_GATTS_SECURITY_LEVELS_CHAR
+#else
+#define UC_BT_GATTS_SECURITY_LEVELS_CHAR         FALSE
+#endif
+
 #ifdef CONFIG_BT_BLE_ACT_SCAN_REP_ADV_SCAN
 #define UC_BT_BLE_ACT_SCAN_REP_ADV_SCAN         CONFIG_BT_BLE_ACT_SCAN_REP_ADV_SCAN
 #else

components/bt/host/bluedroid/common/include/common/bt_target.h

@@ -798,6 +798,12 @@
 #define GATTS_APPEARANCE_WRITABLE FALSE
 #endif
 
+#if (UC_BT_GATTS_SECURITY_LEVELS_CHAR == TRUE)
+#define BT_GATTS_SECURITY_LEVELS_CHAR TRUE
+#else
+#define BT_GATTS_SECURITY_LEVELS_CHAR FALSE
+#endif
+
 #ifdef UC_BT_BLE_ACT_SCAN_REP_ADV_SCAN
 #define BTM_BLE_ACTIVE_SCAN_REPORT_ADV_SCAN_RSP_INDIVIDUALLY    UC_BT_BLE_ACT_SCAN_REP_ADV_SCAN
 #endif

components/bt/host/bluedroid/stack/gap/gap_ble.c

@@ -256,6 +256,12 @@ tGATT_STATUS gap_read_attr_value (UINT16 handle, tGATT_VALUE *p_value, BOOLEAN i
                 UINT8_TO_STREAM(p, p_db_attr->attr_value.addr_resolution);
                 p_value->len = 1;
                 break;
+#if (BT_GATTS_SECURITY_LEVELS_CHAR == TRUE)
+            case GATT_UUID_GAP_GATT_SECURITY_LEVELS:
+                UINT16_TO_STREAM(p, p_db_attr->attr_value.security_level);
+                p_value->len = 2;
+                break;
+#endif // (BT_GATTS_SECURITY_LEVELS_CHAR == TRUE)
             }
             return GATT_SUCCESS;
         }
@@ -464,6 +470,17 @@ void gap_attr_db_init(void)
     p_db_attr->attr_value.addr_resolution = 0;
     p_db_attr++;
 
+#if (BT_GATTS_SECURITY_LEVELS_CHAR == TRUE)
+    /* Add LE Security Levels Characteristic */
+    uuid.len = LEN_UUID_16;
+    uuid.uu.uuid16 = p_db_attr->uuid = GATT_UUID_GAP_GATT_SECURITY_LEVELS;
+    p_db_attr->handle = GATTS_AddCharacteristic(service_handle, &uuid,
+                        GATT_PERM_READ, GATT_CHAR_PROP_BIT_READ,
+                        NULL, NULL);
+    p_db_attr->attr_value.security_level = 0x0101;
+    p_db_attr++;
+#endif // (BT_GATTS_SECURITY_LEVELS_CHAR == TRUE)
+
     /* start service now */
     memset (&app_uuid.uu.uuid128, 0x81, LEN_UUID_128);
 
@@ -517,6 +534,12 @@ void GAP_BleAttrDBUpdate(UINT16 attr_uuid, tGAP_BLE_ATTR_VALUE *p_value)
                 p_db_attr->attr_value.addr_resolution = p_value->addr_resolution;
                 break;
 
+#if (BT_GATTS_SECURITY_LEVELS_CHAR == TRUE)
+            case GATT_UUID_GAP_GATT_SECURITY_LEVELS:
+                p_db_attr->attr_value.security_level = p_value->security_level;
+                break;
+#endif // (BT_GATTS_SECURITY_LEVELS_CHAR == TRUE)
+
             }
             break;
         }

components/bt/host/bluedroid/stack/include/stack/gap_api.h

@@ -119,6 +119,9 @@ typedef union {
     UINT16                  icon;
     UINT8                   *p_dev_name;
     UINT8                   addr_resolution;
+#if (BT_GATTS_SECURITY_LEVELS_CHAR == TRUE)
+    UINT16                  security_level;
+#endif // (BT_GATTS_SECURITY_LEVELS_CHAR == TRUE)
 
 } tGAP_BLE_ATTR_VALUE;
 

components/bt/host/bluedroid/stack/include/stack/gattdefs.h

@@ -52,6 +52,8 @@
 #define GATT_UUID_GAP_PREF_CONN_PARAM    0x2A04
 #define GATT_UUID_GAP_CENTRAL_ADDR_RESOL 0x2AA6
 
+#define GATT_UUID_GAP_GATT_SECURITY_LEVELS 0x2BF5
+
 /* Attribute Profile Attribute UUID */
 #define GATT_UUID_GATT_SRV_CHGD          0x2A05
 /* Attribute Protocol Test */
@@ -81,7 +83,7 @@
 #define GATT_UUID_GM_CONTROL_POINT      0x2A52
 #define GATT_UUID_GM_FEATURE            0x2A51
 
-/* device infor characteristic */
+/* device information characteristic */
 #define GATT_UUID_SYSTEM_ID             0x2A23
 #define GATT_UUID_MODEL_NUMBER_STR      0x2A24
 #define GATT_UUID_SERIAL_NUMBER_STR     0x2A25