tests: Bluetooth: Add some more tests for bt_le_create_conn()

Adds coverage for attempting to connect while already connecting
or connecting to a device that already exists.

Signed-off-by: Rubin Gerritsen <rubin.gerritsen@nordicsemi.no>

tests/bsim/bluetooth/host/central/prj.conf

@@ -1,3 +1,4 @@
 CONFIG_ASSERT=y
 CONFIG_BT=y
 CONFIG_BT_CENTRAL=y
+CONFIG_BT_PERIPHERAL=y

tests/bsim/bluetooth/host/central/src/dummy_peripheral.c

@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2024 Nordic Semiconductor
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "bstests.h"
+#include "babblekit/testcase.h"
+#include <zephyr/bluetooth/conn.h>
+
+static K_SEM_DEFINE(sem_connected, 0, 1);
+
+static void connected_cb(struct bt_conn *conn, uint8_t err)
+{
+	TEST_ASSERT(conn);
+	TEST_ASSERT(err == 0, "Expected success");
+
+	k_sem_give(&sem_connected);
+	bt_conn_unref(conn);
+}
+
+static struct bt_conn_cb conn_cb = {
+	.connected = connected_cb,
+};
+
+static void test_peripheral_dummy(void)
+{
+	int err;
+	const struct bt_data ad[] = {
+		BT_DATA_BYTES(BT_DATA_FLAGS, (BT_LE_AD_GENERAL | BT_LE_AD_NO_BREDR))};
+
+	bt_conn_cb_register(&conn_cb);
+
+	bt_addr_le_t addr = {.type = BT_ADDR_LE_RANDOM,
+			     .a.val = {0xc0, 0xc0, 0xc0, 0xc0, 0xc0, 0xc0}};
+
+	err = bt_id_create(&addr, NULL);
+	TEST_ASSERT(err == 0, "Failed to create iD (err %d)", err);
+
+	/* Initialize Bluetooth */
+	err = bt_enable(NULL);
+	TEST_ASSERT(err == 0, "Can't enable Bluetooth (err %d)", err);
+
+	err = bt_le_adv_start(BT_LE_ADV_CONN_ONE_TIME, ad, ARRAY_SIZE(ad), NULL, 0);
+	TEST_ASSERT(err == 0, "Advertising failed to start (err %d)", err);
+
+	err = k_sem_take(&sem_connected, K_FOREVER);
+	TEST_ASSERT(err == 0, "Failed getting connected timeout", err);
+
+	TEST_PASS("Passed");
+}
+
+static const struct bst_test_instance test_def[] = {{.test_id = "peripheral_dummy",
+						     .test_descr = "Connectable peripheral",
+						     .test_tick_f = bst_tick,
+						     .test_main_f = test_peripheral_dummy},
+						    BSTEST_END_MARKER};
+
+struct bst_test_list *test_peripheral_install(struct bst_test_list *tests)
+{
+	return bst_add_tests(tests, test_def);
+}

tests/bsim/bluetooth/host/central/src/main.c

@@ -8,9 +8,14 @@
 #include "babblekit/testcase.h"
 #include <zephyr/bluetooth/conn.h>
 
+/* Include conn_internal for the purpose of checking reference counts. */
+#include <zephyr/../../subsys/bluetooth/host/conn_internal.h>
+
+struct bst_test_list *test_peripheral_install(struct bst_test_list *tests);
+
 static K_SEM_DEFINE(sem_connected, 0, 1);
 
-static void connected_cb(struct bt_conn *conn, uint8_t err)
+static void connected_cb_expect_fail(struct bt_conn *conn, uint8_t err)
 {
 	TEST_ASSERT(conn);
 	TEST_ASSERT(err == BT_HCI_ERR_UNKNOWN_CONN_ID, "Expected connection timeout");
@@ -19,6 +24,19 @@ static void connected_cb(struct bt_conn *conn, uint8_t err)
 	bt_conn_unref(conn);
 }
 
+static void connected_cb(struct bt_conn *conn, uint8_t err)
+{
+	TEST_ASSERT(conn);
+	TEST_ASSERT(err == 0, "Expected connection establishment");
+
+	k_sem_give(&sem_connected);
+	bt_conn_unref(conn);
+}
+
+static struct bt_conn_cb conn_cb_expect_fail = {
+	.connected = connected_cb_expect_fail,
+};
+
 static struct bt_conn_cb conn_cb = {
 	.connected = connected_cb,
 };
@@ -63,14 +81,15 @@ static void test_central_connect_timeout_with_timeout(uint32_t timeout_ms)
 	TEST_PRINT("Connection timeout after %d ms", time_diff_ms);
 	TEST_ASSERT(diff_to_expected_ms < 0.1 * expected_conn_timeout_ms,
 		    "Connection timeout not within 10%% of expected timeout. "
-		    "Actual timeout: %d", time_diff_ms);
+		    "Actual timeout: %d",
+		    time_diff_ms);
 }
 
 static void test_central_connect_timeout(void)
 {
 	int err;
 
-	bt_conn_cb_register(&conn_cb);
+	bt_conn_cb_register(&conn_cb_expect_fail);
 
 	/* Initialize Bluetooth */
 	err = bt_enable(NULL);
@@ -82,25 +101,118 @@ static void test_central_connect_timeout(void)
 	TEST_PASS("Correct timeout");
 }
 
+static void test_central_connect_when_connecting(void)
+{
+	int err;
+
+	bt_conn_cb_register(&conn_cb);
+
+	/* Initialize Bluetooth */
+	err = bt_enable(NULL);
+	TEST_ASSERT(err == 0, "Can't enable Bluetooth (err %d)", err);
+
+	struct bt_conn *conn;
+
+	bt_addr_le_t peer = {.a.val = {0x01}};
+
+	const struct bt_conn_le_create_param create_param = {
+		.options = BT_CONN_LE_OPT_NONE,
+		.interval = BT_GAP_SCAN_FAST_INTERVAL,
+		.window = BT_GAP_SCAN_FAST_WINDOW,
+	};
+
+	k_sem_reset(&sem_connected);
+
+	err = bt_conn_le_create(&peer, &create_param, BT_LE_CONN_PARAM_DEFAULT, &conn);
+	TEST_ASSERT(err == 0, "Failed starting initiator (err %d)", err);
+
+	/* Now we have a valid connection reference */
+	atomic_val_t initial_refs = atomic_get(&conn->ref);
+
+	TEST_ASSERT(initial_refs >= 1, "Expect to have at least once reference");
+
+	err = bt_conn_le_create(&peer, &create_param, BT_LE_CONN_PARAM_DEFAULT, &conn);
+	TEST_ASSERT(err == -EALREADY, "Expected to fail to create connection (err %d)", err);
+
+	/* Expect the number of refs to be unchanged. */
+	TEST_ASSERT(atomic_get(&conn->ref) == initial_refs,
+		    "Expect number of references to be unchanged");
+
+	err = k_sem_take(&sem_connected, K_FOREVER);
+	TEST_ASSERT(err == 0, "Failed getting connected timeout", err);
+
+	TEST_ASSERT(atomic_get(&conn->ref) == 0, "Expect no more references");
+
+	TEST_PASS("Passed");
+}
+
+static void test_central_connect_to_existing(void)
+{
+	int err;
+
+	bt_conn_cb_register(&conn_cb);
+
+	/* Initialize Bluetooth */
+	err = bt_enable(NULL);
+	TEST_ASSERT(err == 0, "Can't enable Bluetooth (err %d)", err);
+
+	struct bt_conn *conn;
+
+	bt_addr_le_t peer = {.type = BT_ADDR_LE_RANDOM,
+			     .a.val = {0xc0, 0xc0, 0xc0, 0xc0, 0xc0, 0xc0}};
+
+	const struct bt_conn_le_create_param create_param = {
+		.options = BT_CONN_LE_OPT_NONE,
+		.interval = BT_GAP_SCAN_FAST_INTERVAL,
+		.window = BT_GAP_SCAN_FAST_WINDOW,
+	};
+
+	k_sem_reset(&sem_connected);
+
+	err = bt_conn_le_create(&peer, &create_param, BT_LE_CONN_PARAM_DEFAULT, &conn);
+	TEST_ASSERT(err == 0, "Failed starting initiator (err %d)", err);
+
+	err = k_sem_take(&sem_connected, K_FOREVER);
+	TEST_ASSERT(err == 0, "Failed establishing connection", err);
+
+	/* Now we have a valid connection reference */
+	atomic_val_t initial_refs = atomic_get(&conn->ref);
+
+	TEST_ASSERT(initial_refs >= 1, "Expect to have at least once reference");
+
+	err = bt_conn_le_create(&peer, &create_param, BT_LE_CONN_PARAM_DEFAULT, &conn);
+	TEST_ASSERT(err == -EINVAL, "Expected to fail to create a connection (err %d)", err);
+
+	/* Expect the number of refs to be unchanged. */
+	TEST_ASSERT(atomic_get(&conn->ref) == initial_refs,
+		    "Expect number of references to be unchanged");
+
+	TEST_PASS("Passed");
+}
+
 static const struct bst_test_instance test_def[] = {
-	{
-		.test_id = "central_connect_timeout",
-		.test_descr = "Verifies that the default connection timeout is used correctly",
-		.test_tick_f = bst_tick,
-		.test_main_f = test_central_connect_timeout
-	},
-	BSTEST_END_MARKER
-};
+	{.test_id = "central_connect_timeout",
+	 .test_descr = "Verifies that the default connection timeout is used correctly",
+	 .test_tick_f = bst_tick,
+	 .test_main_f = test_central_connect_timeout},
+	{.test_id = "central_connect_when_connecting",
+	 .test_descr = "Verifies that the stack returns an error code when trying to connect"
+		       " while already connecting",
+	 .test_tick_f = bst_tick,
+	 .test_main_f = test_central_connect_when_connecting},
+	{.test_id = "central_connect_to_existing",
+	 .test_descr = "Verifies that the stack returns an error code when trying to connect"
+		       " to an existing device and does not unref the existing connection object.",
+	 .test_tick_f = bst_tick,
+	 .test_main_f = test_central_connect_to_existing},
+	BSTEST_END_MARKER};
 
 static struct bst_test_list *test_central_install(struct bst_test_list *tests)
 {
 	return bst_add_tests(tests, test_def);
 }
 
-bst_test_install_t test_installers[] = {
-	test_central_install,
-	NULL
-};
+bst_test_install_t test_installers[] = {test_central_install, test_peripheral_install, NULL};
 
 int main(void)
 {

tests/bsim/bluetooth/host/central/tests_scripts/run_central_connect_to_existing.sh

@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+# Copyright (c) 2024 Nordic Semiconductor
+# SPDX-License-Identifier: Apache-2.0
+
+source ${ZEPHYR_BASE}/tests/bsim/sh_common.source
+
+simulation_id="central_connect_timeout_to_existing"
+verbosity_level=2
+
+cd ${BSIM_OUT_PATH}/bin
+
+Execute ./bs_${BOARD_TS}_tests_bsim_bluetooth_host_central_prj_conf \
+  -v=${verbosity_level} -s=${simulation_id} -d=0 -testid=central_connect_to_existing
+
+Execute ./bs_${BOARD_TS}_tests_bsim_bluetooth_host_central_prj_conf \
+  -v=${verbosity_level} -s=${simulation_id} -d=1 -testid=peripheral_dummy
+
+Execute ./bs_2G4_phy_v1 -v=${verbosity_level} -s=${simulation_id} \
+  -D=2 -sim_length=60e6 $@
+
+wait_for_background_jobs

tests/bsim/bluetooth/host/central/tests_scripts/run_central_connect_when_connecting.sh

@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+# Copyright (c) 2024 Nordic Semiconductor
+# SPDX-License-Identifier: Apache-2.0
+
+source ${ZEPHYR_BASE}/tests/bsim/sh_common.source
+
+simulation_id="central_connect_when_connecting"
+verbosity_level=2
+
+cd ${BSIM_OUT_PATH}/bin
+
+Execute ./bs_${BOARD_TS}_tests_bsim_bluetooth_host_central_prj_conf \
+  -v=${verbosity_level} -s=${simulation_id} -d=0 -testid=central_connect_when_connecting
+
+Execute ./bs_2G4_phy_v1 -v=${verbosity_level} -s=${simulation_id} \
+  -D=1 -sim_length=60e6 $@
+
+wait_for_background_jobs