tests: bluetooth: host: Add UT for bt_keys_update_usage()

Unit test project for bt_keys_update_usage().
This part of subsys/bluetooth/host/keys.c unit testing.

Signed-off-by: Ahmed Moheb <ahmed.moheb@nordicsemi.no>

subsys/bluetooth/host/keys.c

@@ -542,5 +542,10 @@ uint32_t bt_keys_get_aging_counter_val(void)
 {
 	return aging_counter_val;
 }
+
+struct bt_keys *bt_keys_get_last_keys_updated(void)
+{
+	return last_keys_updated;
+}
 #endif /* CONFIG_BT_KEYS_OVERWRITE_OLDEST */
 #endif /* ZTEST_UNITTEST */

tests/bluetooth/host/keys/bt_keys_update_usage/CMakeLists.txt

@@ -0,0 +1,22 @@
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+
+project(bt_keys_update_usage)
+find_package(Zephyr COMPONENTS unittest HINTS $ENV{ZEPHYR_BASE})
+
+add_subdirectory(${ZEPHYR_BASE}/tests/bluetooth/host host_mocks)
+add_subdirectory(${ZEPHYR_BASE}/tests/bluetooth/host/keys/mocks mocks)
+
+target_link_libraries(testbinary PRIVATE mocks host_mocks)
+
+target_sources(testbinary
+    PRIVATE
+    src/main.c
+    src/test_suite_save_aging_counter.c
+    src/test_suite_update_usage_invalid_inputs.c
+
+    # Unit under test
+    $ENV{ZEPHYR_BASE}/subsys/bluetooth/host/keys.c
+    $ENV{ZEPHYR_BASE}/subsys/bluetooth/common/addr.c
+)

tests/bluetooth/host/keys/bt_keys_update_usage/prj.conf

@@ -0,0 +1,12 @@
+CONFIG_ZTEST=y
+CONFIG_ZTEST_NEW_API=y
+CONFIG_BT=y
+CONFIG_BT_CENTRAL=y
+CONFIG_BT_MAX_PAIRED=11
+CONFIG_ASSERT=y
+CONFIG_ASSERT_LEVEL=2
+CONFIG_ASSERT_VERBOSE=y
+
+CONFIG_LOG=n
+CONFIG_BT_DEBUG_LOG=n
+CONFIG_TEST_LOGGING_DEFAULTS=n

tests/bluetooth/host/keys/bt_keys_update_usage/src/main.c

@@ -0,0 +1,139 @@
+/*
+ * Copyright (c) 2022 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "mocks/keys_help_utils.h"
+#include "mocks/settings_store_expects.h"
+#include "testing_common_defs.h"
+
+#include <zephyr/bluetooth/addr.h>
+#include <zephyr/fff.h>
+#include <zephyr/kernel.h>
+
+#include <host/keys.h>
+
+DEFINE_FFF_GLOBALS;
+
+/* This LUT contains different combinations of ID, Address and key type.
+ * Item in this list will be used to fill keys pool.
+ */
+const struct id_addr_pair testing_id_addr_pair_lut[] = {
+
+	{BT_ADDR_ID_1, BT_ADDR_LE_1},	  {BT_ADDR_ID_1, BT_RPA_ADDR_LE_1},
+	{BT_ADDR_ID_1, BT_RPA_ADDR_LE_2}, {BT_ADDR_ID_1, BT_ADDR_LE_3},
+
+	{BT_ADDR_ID_2, BT_ADDR_LE_1},	  {BT_ADDR_ID_2, BT_RPA_ADDR_LE_2},
+	{BT_ADDR_ID_2, BT_RPA_ADDR_LE_3}, {BT_ADDR_ID_2, BT_ADDR_LE_2},
+
+	{BT_ADDR_ID_3, BT_ADDR_LE_1},	  {BT_ADDR_ID_3, BT_ADDR_LE_2},
+
+	{BT_ADDR_ID_4, BT_ADDR_LE_1}};
+
+/* This list will hold returned references while filling keys pool */
+struct bt_keys *returned_keys_refs[CONFIG_BT_MAX_PAIRED];
+
+/* Holds the last key reference updated */
+static struct bt_keys *last_keys_updated;
+
+BUILD_ASSERT(ARRAY_SIZE(testing_id_addr_pair_lut) == CONFIG_BT_MAX_PAIRED);
+BUILD_ASSERT(ARRAY_SIZE(testing_id_addr_pair_lut) == ARRAY_SIZE(returned_keys_refs));
+
+static void tc_setup(void *f)
+{
+	clear_key_pool();
+	int rv = fill_key_pool_by_id_addr(testing_id_addr_pair_lut,
+					  ARRAY_SIZE(testing_id_addr_pair_lut), returned_keys_refs);
+
+	zassert_true(rv == 0, "Failed to fill keys pool list, error code %d", -rv);
+
+	last_keys_updated = returned_keys_refs[CONFIG_BT_MAX_PAIRED - 1];
+}
+
+ZTEST_SUITE(bt_keys_update_usage_overwrite_oldest_enabled, NULL, NULL, tc_setup, NULL, NULL);
+
+/*
+ *  Request updating non-existing item in the keys pool list
+ *
+ *  Constraints:
+ *   - Keys pool list is filled with items that are different from the testing ID and address pair
+ *     used
+ *
+ *  Expected behaviour:
+ *   - Last updated key reference isn't changed
+ */
+ZTEST(bt_keys_update_usage_overwrite_oldest_enabled, test_update_non_existing_key)
+{
+	uint8_t id = BT_ADDR_ID_5;
+	bt_addr_le_t *addr = BT_ADDR_LE_5;
+
+	bt_keys_update_usage(id, addr);
+
+	zassert_equal_ptr(bt_keys_get_last_keys_updated(), last_keys_updated,
+			  "bt_keys_update_usage() changed last updated key reference unexpectedly");
+}
+
+/*
+ *  Request updating the latest key reference
+ *
+ *  Constraints:
+ *   - Keys pool list is filled with items
+ *   - ID and address pair used are the last added pair to the list
+ *
+ *  Expected behaviour:
+ *   - Last updated key reference isn't changed
+ */
+ZTEST(bt_keys_update_usage_overwrite_oldest_enabled, test_update_latest_reference)
+{
+	uint8_t id = testing_id_addr_pair_lut[CONFIG_BT_MAX_PAIRED - 1].id;
+	bt_addr_le_t *addr = testing_id_addr_pair_lut[CONFIG_BT_MAX_PAIRED - 1].addr;
+
+	bt_keys_update_usage(id, addr);
+
+	zassert_equal_ptr(bt_keys_get_last_keys_updated(), last_keys_updated,
+			  "bt_keys_update_usage() changed last updated key reference unexpectedly");
+}
+
+/*
+ *  Request updating existing items aging counter
+ *
+ *  Constraints:
+ *   - Keys pool list is filled with items
+ *   - ID and address used exist in the keys pool list
+ *   - CONFIG_BT_KEYS_SAVE_AGING_COUNTER_ON_PAIRING isn't enabled
+ *
+ *  Expected behaviour:
+ *   - Last updated key reference matches the last updated key reference
+ */
+ZTEST(bt_keys_update_usage_overwrite_oldest_enabled, test_update_non_latest_reference)
+{
+	uint8_t id;
+	uint32_t old_aging_counter;
+	bt_addr_le_t *addr;
+	struct bt_keys *expected_updated_keys;
+	struct id_addr_pair const *params_vector;
+
+	if (IS_ENABLED(CONFIG_BT_KEYS_SAVE_AGING_COUNTER_ON_PAIRING)) {
+		ztest_test_skip();
+	}
+
+	for (size_t it = 0; it < ARRAY_SIZE(testing_id_addr_pair_lut); it++) {
+		params_vector = &testing_id_addr_pair_lut[it];
+		id = params_vector->id;
+		addr = params_vector->addr;
+		expected_updated_keys = returned_keys_refs[it];
+		old_aging_counter = expected_updated_keys->aging_counter;
+
+		bt_keys_update_usage(id, addr);
+
+		zassert_true(expected_updated_keys->aging_counter > (old_aging_counter),
+			     "bt_keys_update_usage() set incorrect aging counter");
+
+		zassert_equal_ptr(
+			bt_keys_get_last_keys_updated(), expected_updated_keys,
+			"bt_keys_update_usage() changed last updated key reference unexpectedly");
+
+		expect_not_called_settings_save_one();
+	}
+}

tests/bluetooth/host/keys/bt_keys_update_usage/src/test_suite_save_aging_counter.c

@@ -0,0 +1,82 @@
+/*
+ * Copyright (c) 2022 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "mocks/keys_help_utils.h"
+#include "mocks/settings_store.h"
+#include "mocks/settings_store_expects.h"
+#include "testing_common_defs.h"
+
+#include <zephyr/bluetooth/addr.h>
+#include <zephyr/kernel.h>
+
+#include <host/keys.h>
+
+/* This LUT contains different combinations of ID and Address pairs.
+ * It is defined in main.c.
+ */
+extern const struct id_addr_pair testing_id_addr_pair_lut[CONFIG_BT_MAX_PAIRED];
+
+/* This list holds returned references while filling keys pool.
+ * It is defined in main.c.
+ */
+extern struct bt_keys *returned_keys_refs[CONFIG_BT_MAX_PAIRED];
+
+static void tc_setup(void *f)
+{
+	Z_TEST_SKIP_IFNDEF(CONFIG_BT_KEYS_SAVE_AGING_COUNTER_ON_PAIRING);
+
+	clear_key_pool();
+	int rv = fill_key_pool_by_id_addr(testing_id_addr_pair_lut,
+					  ARRAY_SIZE(testing_id_addr_pair_lut), returned_keys_refs);
+
+	zassert_true(rv == 0, "Failed to fill keys pool list, error code %d", -rv);
+}
+
+ZTEST_SUITE(bt_keys_update_usage_save_aging_counter, NULL, NULL, tc_setup, NULL, NULL);
+
+/*
+ *  Request updating existing items aging counter
+ *
+ *  Constraints:
+ *   - Keys pool list is filled with items
+ *   - ID and address used exist in the keys pool list
+ *   - CONFIG_BT_KEYS_SAVE_AGING_COUNTER_ON_PAIRING is enabled
+ *
+ *  Expected behaviour:
+ *   - Last updated key reference matches the last updated key reference
+ *   - bt_keys_store() is called once with the correct parameters
+ */
+ZTEST(bt_keys_update_usage_save_aging_counter, test_update_usage_and_save_aging_counter)
+{
+	uint8_t id;
+	uint32_t old_aging_counter;
+	bt_addr_le_t *addr;
+	struct bt_keys *expected_updated_keys;
+	struct id_addr_pair const *params_vector;
+
+	for (size_t it = 0; it < ARRAY_SIZE(testing_id_addr_pair_lut); it++) {
+		params_vector = &testing_id_addr_pair_lut[it];
+		id = params_vector->id;
+		addr = params_vector->addr;
+		expected_updated_keys = returned_keys_refs[it];
+		old_aging_counter = expected_updated_keys->aging_counter;
+
+		/* Reset fake functions call counter */
+		SETTINGS_STORE_FFF_FAKES_LIST(RESET_FAKE);
+
+		bt_keys_update_usage(id, addr);
+
+		zassert_true(expected_updated_keys->aging_counter > (old_aging_counter),
+			     "bt_keys_update_usage() set incorrect aging counter");
+
+		zassert_equal_ptr(
+			bt_keys_get_last_keys_updated(), expected_updated_keys,
+			"bt_keys_update_usage() changed last updated key reference unexpectedly");
+
+		/* Check if bt_keys_store() was called */
+		expect_single_call_settings_save_one(expected_updated_keys->storage_start);
+	}
+}

tests/bluetooth/host/keys/bt_keys_update_usage/src/test_suite_update_usage_invalid_inputs.c

@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) 2022 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "host_mocks/assert.h"
+
+#include <zephyr/bluetooth/bluetooth.h>
+#include <zephyr/kernel.h>
+
+#include <host/keys.h>
+
+ZTEST_SUITE(bt_keys_update_usage_invalid_inputs, NULL, NULL, NULL, NULL, NULL);
+
+/*
+ *  Test function with NULL address
+ *
+ *  Constraints:
+ *   - Any ID value can be used
+ *   - Address is passed as NULL
+ *
+ *  Expected behaviour:
+ *   - An assertion fails and execution stops
+ */
+ZTEST(bt_keys_update_usage_invalid_inputs, test_null_device_address)
+{
+	expect_assert();
+	bt_keys_update_usage(0x00, NULL);
+}

tests/bluetooth/host/keys/bt_keys_update_usage/testcase.yaml

@@ -0,0 +1,16 @@
+common:
+    tags: test_framework bluetooth host
+tests:
+  bluetooth.host.bt_keys_update_usage.default:
+     type: unit
+     extra_configs:
+      - CONFIG_BT_SMP=y
+      - CONFIG_BT_KEYS_OVERWRITE_OLDEST=y
+  bluetooth.host.bt_keys_update_usage.save_aging_counter:
+     type: unit
+     extra_configs:
+      - CONFIG_SETTINGS=y
+      - CONFIG_BT_SETTINGS=y
+      - CONFIG_BT_SMP=y
+      - CONFIG_BT_KEYS_OVERWRITE_OLDEST=y
+      - CONFIG_BT_KEYS_SAVE_AGING_COUNTER_ON_PAIRING=y

tests/bluetooth/host/keys/mocks/keys_help_utils.h

@@ -23,6 +23,7 @@ struct id_addr_type {
 struct bt_keys *bt_keys_get_key_pool(void);
 #if defined(CONFIG_BT_KEYS_OVERWRITE_OLDEST)
 uint32_t bt_keys_get_aging_counter_val(void);
+struct bt_keys *bt_keys_get_last_keys_updated(void);
 #endif
 
 /* keys_help_utils.c declarations */

tests/bluetooth/host/keys/mocks/settings_store_expects.c

@@ -35,3 +35,11 @@ void expect_single_call_settings_save_one(const void *value)
 	zassert_equal(settings_save_one_fake.arg2_val, BT_KEYS_STORAGE_LEN,
 		      "'%s()' was called with incorrect '%s' value", func_name, "val_len");
 }
+
+void expect_not_called_settings_save_one(void)
+{
+	const char *func_name = "settings_save_one";
+
+	zassert_equal(settings_save_one_fake.call_count, 0, "'%s()' was called unexpectedly",
+		      func_name);
+}

tests/bluetooth/host/keys/mocks/settings_store_expects.h

@@ -21,3 +21,11 @@ void expect_single_call_settings_delete(void);
  *   - settings_save_one() to be called once with correct parameters
  */
 void expect_single_call_settings_save_one(const void *value);
+
+/*
+ *  Validate expected behaviour when settings_save_one() isn't called
+ *
+ *  Expected behaviour:
+ *   - settings_save_one() isn't called at all
+ */
+void expect_not_called_settings_save_one(void);