Bluetooth: Host: Add sending L2CAP data from connection callback test

Add BabbleSim test to make sure data can be sent immediately upon
connection from the L2CAP channel connection callback

Signed-off-by: Donatien Garnier <donatien.garnier@blecon.net>

tests/bsim/bluetooth/host/compile.sh

@@ -53,6 +53,8 @@ app=tests/bsim/bluetooth/host/l2cap/credits compile
 app=tests/bsim/bluetooth/host/l2cap/credits conf_file=prj_ecred.conf compile
 app=tests/bsim/bluetooth/host/l2cap/credits_seg_recv compile
 app=tests/bsim/bluetooth/host/l2cap/credits_seg_recv conf_file=prj_ecred.conf compile
+app=tests/bsim/bluetooth/host/l2cap/send_on_connect compile
+app=tests/bsim/bluetooth/host/l2cap/send_on_connect conf_file=prj_ecred.conf compile
 
 app=tests/bsim/bluetooth/host/misc/disable compile
 

tests/bsim/bluetooth/host/l2cap/send_on_connect/CMakeLists.txt

@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(bsim_test_l2cap_send_on_connect)
+
+target_sources(app PRIVATE
+  src/common.c
+  src/main_l2cap_send_on_connect.c
+  src/main.c
+)
+
+zephyr_include_directories(
+  ${BSIM_COMPONENTS_PATH}/libUtilv1/src/
+  ${BSIM_COMPONENTS_PATH}/libPhyComv1/src/
+  )

tests/bsim/bluetooth/host/l2cap/send_on_connect/prj.conf

@@ -0,0 +1,10 @@
+CONFIG_BT=y
+CONFIG_BT_CENTRAL=y
+CONFIG_BT_PERIPHERAL=y
+CONFIG_BT_SMP=y
+CONFIG_BT_L2CAP_DYNAMIC_CHANNEL=y
+CONFIG_BT_L2CAP_ECRED=n
+
+CONFIG_BT_BUF_ACL_RX_SIZE=75
+
+CONFIG_ASSERT=y

tests/bsim/bluetooth/host/l2cap/send_on_connect/prj_ecred.conf

@@ -0,0 +1,10 @@
+CONFIG_BT=y
+CONFIG_BT_CENTRAL=y
+CONFIG_BT_PERIPHERAL=y
+CONFIG_BT_SMP=y
+CONFIG_BT_L2CAP_DYNAMIC_CHANNEL=y
+CONFIG_BT_L2CAP_ECRED=y
+
+CONFIG_BT_BUF_ACL_RX_SIZE=75
+
+CONFIG_ASSERT=y

tests/bsim/bluetooth/host/l2cap/send_on_connect/src/common.c

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2022 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "common.h"
+
+extern enum bst_result_t bst_result;
+
+void test_init(void)
+{
+	bst_result = In_progress;
+	bst_ticker_set_next_tick_absolute(WAIT_TIME);
+}
+
+void test_tick(bs_time_t HW_device_time)
+{
+	if (bst_result != Passed) {
+		FAIL("test failed (not passed after %i us)\n", WAIT_TIME);
+	}
+}

tests/bsim/bluetooth/host/l2cap/send_on_connect/src/common.h

@@ -0,0 +1,44 @@
+/*
+ * Common functions and helpers for L2CAP tests
+ *
+ * Copyright (c) 2022 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <stddef.h>
+
+#include "bs_types.h"
+#include "bs_tracing.h"
+#include "bstests.h"
+
+#define CREATE_FLAG(flag) static atomic_t flag = (atomic_t)false
+#define SET_FLAG(flag) (void)atomic_set(&flag, (atomic_t)true)
+#define UNSET_FLAG(flag) (void)atomic_set(&flag, (atomic_t)false)
+#define WAIT_FOR_FLAG_SET(flag)		   \
+	while (!(bool)atomic_get(&flag)) { \
+		(void)k_sleep(K_MSEC(1));  \
+	}
+#define WAIT_FOR_FLAG_UNSET(flag)	  \
+	while ((bool)atomic_get(&flag)) { \
+		(void)k_sleep(K_MSEC(1)); \
+	}
+
+
+#define WAIT_TIME (30e6) /* 30 seconds*/
+
+#define FAIL(...)				       \
+	do {					       \
+		bst_result = Failed;		       \
+		bs_trace_error_time_line(__VA_ARGS__); \
+	} while (0)
+
+#define PASS(...)				    \
+	do {					    \
+		bst_result = Passed;		    \
+		bs_trace_info_time(1, __VA_ARGS__); \
+	} while (0)
+
+
+void test_init(void);
+void test_tick(bs_time_t HW_device_time);

tests/bsim/bluetooth/host/l2cap/send_on_connect/src/main.c

@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2022 Nordic Semiconductor
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "bstests.h"
+
+extern struct bst_test_list *test_main_l2cap_send_on_connect_install(struct bst_test_list *tests);
+
+bst_test_install_t test_installers[] = {
+	test_main_l2cap_send_on_connect_install,
+	NULL
+};
+
+int main(void)
+{
+	bst_main();
+	return 0;
+}

tests/bsim/bluetooth/host/l2cap/send_on_connect/src/main_l2cap_send_on_connect.c

@@ -0,0 +1,259 @@
+/*
+ * Copyright (c) 2022 Nordic Semiconductor
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "common.h"
+
+#include <zephyr/bluetooth/bluetooth.h>
+#include <zephyr/bluetooth/l2cap.h>
+
+extern enum bst_result_t bst_result;
+
+static struct bt_conn *default_conn;
+
+#define PSM 0x80
+
+CREATE_FLAG(is_connected);
+CREATE_FLAG(chan_connected);
+CREATE_FLAG(data_received);
+
+#define DATA_BYTE_VAL  0xBB
+
+/* L2CAP channel buffer pool */
+NET_BUF_POOL_DEFINE(buf_pool, 1, BT_L2CAP_SDU_BUF_SIZE(16), 8, NULL);
+
+static void chan_connected_cb(struct bt_l2cap_chan *l2cap_chan)
+{
+	struct net_buf *buf;
+	int err;
+
+	/* Send data immediately on L2CAP connection */
+	buf = net_buf_alloc(&buf_pool, K_NO_WAIT);
+	if (!buf) {
+		FAIL("Buffer allocation failed\n");
+	}
+
+	(void)net_buf_reserve(buf, BT_L2CAP_SDU_CHAN_SEND_RESERVE);
+	(void)net_buf_add_u8(buf, DATA_BYTE_VAL);
+
+	/* Try to send data */
+	err = bt_l2cap_chan_send(l2cap_chan, buf);
+	if (err) {
+		FAIL("Could not send data, error %d\n", err);
+	}
+
+	SET_FLAG(chan_connected);
+}
+
+static void chan_disconnected_cb(struct bt_l2cap_chan *l2cap_chan)
+{
+	(void)l2cap_chan;
+
+	UNSET_FLAG(chan_connected);
+}
+
+static int chan_recv_cb(struct bt_l2cap_chan *chan, struct net_buf *buf)
+{
+	(void)chan;
+
+	if ((buf->len != 1) || (buf->data[0] != DATA_BYTE_VAL)) {
+		FAIL("Unexpected data received");
+	}
+
+	SET_FLAG(data_received);
+
+	return 0;
+}
+
+static const struct bt_l2cap_chan_ops l2cap_ops = {
+	.connected = chan_connected_cb,
+	.disconnected = chan_disconnected_cb,
+	.recv = chan_recv_cb,
+};
+
+static struct bt_l2cap_le_chan channel;
+
+static int accept(struct bt_conn *conn, struct bt_l2cap_chan **l2cap_chan)
+{
+	channel.chan.ops = &l2cap_ops;
+	*l2cap_chan = &channel.chan;
+
+	return 0;
+}
+
+static struct bt_l2cap_server server = {
+	.accept = accept,
+	.sec_level = BT_SECURITY_L1,
+	.psm = PSM,
+};
+
+static void connect_l2cap_channel(void)
+{
+	struct bt_l2cap_chan *chans[] = {&channel.chan, NULL};
+	int err;
+
+	channel.chan.ops = &l2cap_ops;
+
+	if (IS_ENABLED(CONFIG_BT_L2CAP_ECRED)) {
+		err = bt_l2cap_ecred_chan_connect(default_conn, chans, server.psm);
+		if (err) {
+			FAIL("Failed to send ecred connection request (err %d)\n", err);
+		}
+	} else {
+		err = bt_l2cap_chan_connect(default_conn, &channel.chan, server.psm);
+		if (err) {
+			FAIL("Failed to send connection request (err %d)\n", err);
+		}
+	}
+}
+
+static void register_l2cap_server(void)
+{
+	int err;
+
+	err = bt_l2cap_server_register(&server);
+	if (err < 0) {
+		FAIL("Failed to get free server (err %d)\n");
+		return;
+	}
+}
+
+static void connected(struct bt_conn *conn, uint8_t err)
+{
+	if (err) {
+		FAIL("Failed to connect (err %d)\n", err);
+		bt_conn_unref(default_conn);
+		default_conn = NULL;
+		return;
+	}
+
+	default_conn = bt_conn_ref(conn);
+
+	SET_FLAG(is_connected);
+}
+
+static void disconnected(struct bt_conn *conn, uint8_t reason)
+{
+	if (default_conn != conn) {
+		FAIL("Connection mismatch %p %p)\n", default_conn, conn);
+		return;
+	}
+
+	bt_conn_unref(default_conn);
+	default_conn = NULL;
+	UNSET_FLAG(is_connected);
+}
+
+BT_CONN_CB_DEFINE(conn_callbacks) = {
+	.connected = connected,
+	.disconnected = disconnected,
+};
+
+static void device_found(const bt_addr_le_t *addr, int8_t rssi, uint8_t type,
+			 struct net_buf_simple *ad)
+{
+	struct bt_le_conn_param *param;
+	int err;
+
+	err = bt_le_scan_stop();
+	if (err) {
+		FAIL("Failed to stop scanning (err %d)\n", err);
+		return;
+	}
+
+	param = BT_LE_CONN_PARAM_DEFAULT;
+	err = bt_conn_le_create(addr, BT_CONN_LE_CREATE_CONN, param, &default_conn);
+	if (err) {
+		FAIL("Failed to create connection (err %d)\n", err);
+		return;
+	}
+}
+
+static void test_peripheral_main(void)
+{
+	int err;
+	const struct bt_data ad[] = {
+		BT_DATA_BYTES(BT_DATA_FLAGS, (BT_LE_AD_GENERAL | BT_LE_AD_NO_BREDR)),
+	};
+
+	err = bt_enable(NULL);
+	if (err != 0) {
+		FAIL("Bluetooth init failed (err %d)\n", err);
+		return;
+	}
+
+	register_l2cap_server();
+
+	err = bt_le_adv_start(BT_LE_ADV_CONN_NAME, ad, ARRAY_SIZE(ad), NULL, 0);
+	if (err != 0) {
+		FAIL("Advertising failed to start (err %d)\n", err);
+		return;
+	}
+
+	WAIT_FOR_FLAG_SET(is_connected);
+
+	WAIT_FOR_FLAG_SET(chan_connected);
+
+	WAIT_FOR_FLAG_SET(data_received);
+
+	WAIT_FOR_FLAG_UNSET(is_connected);
+
+	PASS("Test passed\n");
+}
+
+static void test_central_main(void)
+{
+	int err;
+
+	err = bt_enable(NULL);
+	if (err != 0) {
+		FAIL("Bluetooth init failed (err %d)\n", err);
+	}
+
+	err = bt_le_scan_start(BT_LE_SCAN_PASSIVE, device_found);
+	if (err != 0) {
+		FAIL("Scanning failed to start (err %d)\n", err);
+	}
+
+	WAIT_FOR_FLAG_SET(is_connected);
+
+	connect_l2cap_channel();
+	WAIT_FOR_FLAG_SET(chan_connected);
+
+	WAIT_FOR_FLAG_SET(data_received);
+
+	err = bt_conn_disconnect(default_conn, BT_HCI_ERR_REMOTE_USER_TERM_CONN);
+	if (err) {
+		FAIL("Failed to disconnect (err %d)\n", err);
+		return;
+	}
+
+	WAIT_FOR_FLAG_UNSET(is_connected);
+
+	PASS("Test passed\n");
+}
+
+static const struct bst_test_instance test_def[] = {
+	{
+		.test_id = "peripheral",
+		.test_descr = "Peripheral",
+		.test_post_init_f = test_init,
+		.test_tick_f = test_tick,
+		.test_main_f = test_peripheral_main,
+	},
+	{
+		.test_id = "central",
+		.test_descr = "Central",
+		.test_post_init_f = test_init,
+		.test_tick_f = test_tick,
+		.test_main_f = test_central_main,
+	},
+	BSTEST_END_MARKER,
+};
+
+struct bst_test_list *test_main_l2cap_send_on_connect_install(struct bst_test_list *tests)
+{
+	return bst_add_tests(tests, test_def);
+}

tests/bsim/bluetooth/host/l2cap/send_on_connect/tests_scripts/l2cap.sh

@@ -0,0 +1,39 @@
+#!/usr/bin/env bash
+# Copyright (c) 2022 Nordic Semiconductor
+# SPDX-License-Identifier: Apache-2.0
+
+source ${ZEPHYR_BASE}/tests/bsim/sh_common.source
+
+simulation_id="l2cap_send_on_connect"
+verbosity_level=2
+EXECUTE_TIMEOUT=120
+
+cd ${BSIM_OUT_PATH}/bin
+
+Execute ./bs_${BOARD}_tests_bsim_bluetooth_host_l2cap_send_on_connect_prj_conf \
+    -v=${verbosity_level} -s=${simulation_id} -d=0 -testid=central
+
+Execute ./bs_${BOARD}_tests_bsim_bluetooth_host_l2cap_send_on_connect_prj_conf \
+    -v=${verbosity_level} -s=${simulation_id} -d=1 -testid=peripheral
+
+Execute ./bs_2G4_phy_v1 -v=${verbosity_level} -s=${simulation_id} \
+    -D=2 -sim_length=30e6 $@
+
+wait_for_background_jobs
+
+simulation_id="l2cap_send_on_connect_ecred"
+verbosity_level=2
+EXECUTE_TIMEOUT=120
+
+cd ${BSIM_OUT_PATH}/bin
+
+Execute ./bs_${BOARD}_tests_bsim_bluetooth_host_l2cap_send_on_connect_prj_ecred_conf \
+    -v=${verbosity_level} -s=${simulation_id} -d=0 -testid=central
+
+Execute ./bs_${BOARD}_tests_bsim_bluetooth_host_l2cap_send_on_connect_prj_ecred_conf \
+    -v=${verbosity_level} -s=${simulation_id} -d=1 -testid=peripheral
+
+Execute ./bs_2G4_phy_v1 -v=${verbosity_level} -s=${simulation_id} \
+    -D=2 -sim_length=30e6 $@
+
+wait_for_background_jobs