Bluetooth: Immediate Alert Service

include/zephyr/bluetooth/services/ias.h

@@ -0,0 +1,71 @@
+/*
+ * Copyright (c) 2022 Codecoup
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef ZEPHYR_INCLUDE_BLUETOOTH_SERVICES_IAS_H_
+#define ZEPHYR_INCLUDE_BLUETOOTH_SERVICES_IAS_H_
+
+/**
+ * @brief Immediate Alert Service (IAS)
+ * @defgroup bt_ias Immediate Alert Service (IAS)
+ * @ingroup bluetooth
+ * @{
+ *
+ * [Experimental] Users should note that the APIs can change
+ * as a part of ongoing development.
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/** @brief Immediate Alert Service callback structure. */
+struct bt_ias_cb {
+	/**
+	 * @brief Callback function to stop alert.
+	 *
+	 * This callback is called when peer commands to disable alert.
+	 */
+	void (*no_alert)(void);
+
+	/**
+	 * @brief Callback function for alert level value.
+	 *
+	 * This callback is called when peer commands to alert.
+	 */
+	void (*mild_alert)(void);
+
+	/**
+	 * @brief Callback function for alert level value.
+	 *
+	 * This callback is called when peer commands to alert in the strongest possible way.
+	 */
+	void (*high_alert)(void);
+};
+
+/** @brief Method for stopping alert locally
+ *
+ *  @return Zero in case of success and error code in case of error.
+ */
+int bt_ias_local_alert_stop(void);
+
+/** @def BT_IAS_CB_DEFINE
+ *
+ *  @brief Register a callback structure for immediate alert events.
+ *
+ *  @param _name Name of callback structure.
+ */
+#define BT_IAS_CB_DEFINE(_name)                                                                    \
+	static const STRUCT_SECTION_ITERABLE(bt_ias_cb, _CONCAT(bt_ias_cb_, _name))
+
+#ifdef __cplusplus
+}
+#endif
+
+/**
+ * @}
+ */
+
+#endif /* ZEPHYR_INCLUDE_BLUETOOTH_SERVICES_IAS_H_ */

include/zephyr/linker/common-rom.ld

@@ -136,6 +136,10 @@
 	ITERABLE_SECTION_ROM(bt_mesh_lpn_cb, 4)
 #endif
 
+#if defined(CONFIG_BT_IAS)
+	ITERABLE_SECTION_ROM(bt_ias_cb, 4)
+#endif
+
 #if defined(CONFIG_BT_MESH_GATT_PROXY)
 	ITERABLE_SECTION_ROM(bt_mesh_proxy_cb, 4)
 #endif

samples/bluetooth/peripheral/prj.conf

@@ -10,6 +10,7 @@ CONFIG_BT_DIS=y
 CONFIG_BT_ATT_PREPARE_COUNT=5
 CONFIG_BT_BAS=y
 CONFIG_BT_HRS=y
+CONFIG_BT_IAS=y
 CONFIG_BT_PRIVACY=y
 CONFIG_BT_DEVICE_NAME="Zephyr Peripheral Sample Long Name"
 CONFIG_BT_DEVICE_APPEARANCE=833

samples/bluetooth/peripheral/src/main.c

@@ -23,6 +23,7 @@
 #include <bluetooth/gatt.h>
 #include <bluetooth/services/bas.h>
 #include <bluetooth/services/hrs.h>
+#include <bluetooth/services/ias.h>
 
 #include "cts.h"
 
@@ -248,11 +249,32 @@ static void disconnected(struct bt_conn *conn, uint8_t reason)
 	printk("Disconnected (reason 0x%02x)\n", reason);
 }
 
+static void alert_stop(void)
+{
+	printk("Alert stopped\n");
+}
+
+static void alert_start(void)
+{
+	printk("Mild alert started\n");
+}
+
+static void alert_high_start(void)
+{
+	printk("High alert started\n");
+}
+
 BT_CONN_CB_DEFINE(conn_callbacks) = {
 	.connected = connected,
 	.disconnected = disconnected,
 };
 
+BT_IAS_CB_DEFINE(ias_callbacks) = {
+	.no_alert = alert_stop,
+	.mild_alert = alert_start,
+	.high_alert = alert_high_start,
+};
+
 static void bt_ready(void)
 {
 	int err;

subsys/bluetooth/services/CMakeLists.txt

@@ -9,6 +9,8 @@ zephyr_sources_ifdef(CONFIG_BT_HRS hrs.c)
 
 zephyr_sources_ifdef(CONFIG_BT_TPS tps.c)
 
+zephyr_sources_ifdef(CONFIG_BT_IAS ias.c)
+
 if(CONFIG_BT_OTS OR CONFIG_BT_OTS_CLIENT)
   add_subdirectory(ots)
 endif()

subsys/bluetooth/services/Kconfig

@@ -14,6 +14,8 @@ rsource "Kconfig.hrs"
 
 rsource "Kconfig.tps"
 
+rsource "Kconfig.ias"
+
 rsource "ots/Kconfig"
 
 endmenu

subsys/bluetooth/services/Kconfig.ias

@@ -0,0 +1,33 @@
+# Bluetooth GATT Immediate Alert Service
+
+# Copyright (c) 2022 Codecoup
+# SPDX-License-Identifier: Apache-2.0
+
+menuconfig BT_IAS
+	bool "Support for GATT Immediate Alert Service [EXPERIMENTAL]"
+	select EXPERIMENTAL
+
+if BT_IAS
+
+choice BT_IAS_SEC_CHOICE
+	prompt "Default permissions used for IAS characteristics"
+	default BT_IAS_SEC_NONE
+	help
+	  Default write permissions for IAS characteristic attributes
+
+config BT_IAS_SEC_NONE
+	bool "No security required"
+
+config BT_IAS_SEC_ENC
+	bool "Require encryption for write access"
+
+config BT_IAS_SEC_AUTH
+	bool "Require encryption and authentication for write access"
+
+endchoice #BT_IAS_SEC_CHOICE
+
+module = BT_IAS
+module-str = IAS
+source "${ZEPHYR_BASE}/subsys/logging/Kconfig.template.log_config"
+
+endif # BT_IAS

subsys/bluetooth/services/ias.c

@@ -0,0 +1,143 @@
+/** @file
+ *  @brief Immediate Alert Service implementation
+ */
+
+/*
+ * Copyright (c) 2022 Codecoup
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <errno.h>
+#include <init.h>
+#include <stdint.h>
+#include <zephyr.h>
+#include <net/buf.h>
+#include <logging/log.h>
+#include <bluetooth/gatt.h>
+#include <bluetooth/conn.h>
+#include <bluetooth/services/ias.h>
+
+#define LOG_LEVEL CONFIG_BT_IAS_LOG_LEVEL
+LOG_MODULE_REGISTER(ias);
+
+#define BT_IAS_ALERT_LVL_LEN 1
+
+#if defined(CONFIG_BT_IAS_SEC_AUTH)
+#define IAS_ALERT_LEVEL_PERM BT_GATT_PERM_WRITE_AUTHEN
+#elif defined(CONFIG_BT_IAS_SEC_ENC)
+#define IAS_ALERT_LEVEL_PERM BT_GATT_PERM_WRITE_ENCRYPT
+#else
+#define IAS_ALERT_LEVEL_PERM BT_GATT_PERM_WRITE
+#endif
+
+enum bt_ias_alert_lvl {
+	BT_IAS_ALERT_LVL_NO_ALERT,
+	BT_IAS_ALERT_LVL_MILD_ALERT,
+	BT_IAS_ALERT_LVL_HIGH_ALERT,
+};
+
+struct alerting_device {
+	enum bt_ias_alert_lvl alert_level;
+};
+
+static struct alerting_device devices[CONFIG_BT_MAX_CONN];
+static enum bt_ias_alert_lvl curr_lvl;
+
+static void set_alert_level(void)
+{
+	enum bt_ias_alert_lvl alert_level;
+
+	alert_level = devices[0].alert_level;
+	for (int i = 1; i < CONFIG_BT_MAX_CONN; i++) {
+		if (alert_level < devices[i].alert_level) {
+			alert_level = devices[i].alert_level;
+		}
+	}
+
+	if (curr_lvl == alert_level) {
+		return;
+	}
+
+	if (alert_level == BT_IAS_ALERT_LVL_HIGH_ALERT) {
+		STRUCT_SECTION_FOREACH(bt_ias_cb, cb) {
+			if (cb->high_alert) {
+				cb->high_alert();
+			}
+		}
+		LOG_DBG("High alert");
+	} else if (alert_level == BT_IAS_ALERT_LVL_MILD_ALERT) {
+		STRUCT_SECTION_FOREACH(bt_ias_cb, cb) {
+			if (cb->mild_alert) {
+				cb->mild_alert();
+			}
+		}
+		LOG_DBG("Mild alert");
+	} else {
+		STRUCT_SECTION_FOREACH(bt_ias_cb, cb) {
+			if (cb->no_alert) {
+				cb->no_alert();
+			}
+		}
+		LOG_DBG("No alert");
+	}
+	curr_lvl = alert_level;
+}
+
+static void disconnected(struct bt_conn *conn, uint8_t reason)
+{
+	devices[bt_conn_index(conn)].alert_level = BT_IAS_ALERT_LVL_NO_ALERT;
+	set_alert_level();
+}
+
+int bt_ias_local_alert_stop(void)
+{
+	if (curr_lvl == BT_IAS_ALERT_LVL_NO_ALERT) {
+		return -EALREADY;
+	}
+
+	for (int idx = 0; idx < CONFIG_BT_MAX_CONN; idx++) {
+		devices[idx].alert_level = BT_IAS_ALERT_LVL_NO_ALERT;
+	}
+	curr_lvl = BT_IAS_ALERT_LVL_NO_ALERT;
+	set_alert_level();
+
+	return 0;
+}
+
+static ssize_t bt_ias_write_alert_lvl(struct bt_conn *conn, const struct bt_gatt_attr *attr,
+				      const void *buf, uint16_t len, uint16_t offset, uint8_t flags)
+{
+	struct net_buf_simple data;
+	enum bt_ias_alert_lvl alert_val;
+
+	if (offset > 0) {
+		return BT_GATT_ERR(BT_ATT_ERR_INVALID_OFFSET);
+	}
+
+	if (len != BT_IAS_ALERT_LVL_LEN) {
+		return BT_GATT_ERR(BT_ATT_ERR_INVALID_ATTRIBUTE_LEN);
+	}
+
+	net_buf_simple_init_with_data(&data, (void *)buf, len);
+	alert_val = net_buf_simple_pull_u8(&data);
+	devices[bt_conn_index(conn)].alert_level = alert_val;
+
+	if (alert_val < BT_IAS_ALERT_LVL_NO_ALERT || alert_val > BT_IAS_ALERT_LVL_HIGH_ALERT) {
+		return BT_GATT_ERR(BT_ATT_ERR_VALUE_NOT_ALLOWED);
+	}
+	set_alert_level();
+
+	return len;
+}
+
+BT_CONN_CB_DEFINE(conn_callbacks) = {
+	.disconnected = disconnected,
+};
+
+/* Immediate Alert Service Declaration */
+BT_GATT_SERVICE_DEFINE(ias_svc,
+	BT_GATT_PRIMARY_SERVICE(BT_UUID_IAS),
+	BT_GATT_CHARACTERISTIC(BT_UUID_ALERT_LEVEL, BT_GATT_CHRC_WRITE_WITHOUT_RESP,
+			       IAS_ALERT_LEVEL_PERM, NULL,
+			       bt_ias_write_alert_lvl, NULL));