net: conn_mgr_connectivity: idle/inactivity timeout

doc/connectivity/networking/conn_mgr/main.rst

@@ -294,6 +294,14 @@ You can individually set them for each iface.
    It is left to connectivity implementations to successfully and accurately implement these two features as described below.
    See :ref:`conn_mgr_impl_timeout_persistence` for more details from the connectivity implementation perspective.
 
+The Connection Manager also implements the following optional feature:
+
+* :ref:`Interface idle timeouts <conn_mgr_control_idle_timeout>`
+
+.. note::
+   The only requirement on the connectivity implementation to implement idle timeouts is to call :c:func:`conn_mgr_if_used` each
+   time the interface is used.
+
 .. _conn_mgr_control_timeouts:
 
 Connection Timeouts
@@ -306,6 +314,16 @@ The connection attempt continues indefinitely until it succeeds, unless a timeou
 In that case, the connection attempt will be abandoned if the timeout elapses before it succeeds.
 If this happens, the :ref:`timeout event<conn_mgr_control_events_timeout>` is raised.
 
+.. _conn_mgr_control_idle_timeout:
+
+Interface Idle Timeout
+----------------------
+
+The connection manager enables users to apply an inactivity timeout on an interface (:c:func:`conn_mgr_if_set_idle_timeout`).
+Once connected, if the interface goes for the configured number of seconds without any activity, the interface is automatically disconnected.
+If this happens, the :ref:`idle timeout event<conn_mgr_control_events_idle_timeout>` is raised.
+An idle timeout is considered an unintentional connection loss for the purposes of :ref:`Connection persistence <conn_mgr_control_persistence>`.
+
 .. _conn_mgr_control_persistence:
 
 Connection Persistence
@@ -357,6 +375,15 @@ The :c:macro:`NET_EVENT_CONN_IF_TIMEOUT` event is raised when an :ref:`iface ass
 
 Handlers of this event will be passed a pointer to the iface that timed out attempting to associate.
 
+.. _conn_mgr_control_events_idle_timeout:
+
+Idle Timeout
+------------
+
+The :c:macro:`NET_EVENT_CONN_IF_IDLE_TIMEOUT` event is raised when an interface is considered :ref:`inactive <conn_mgr_control_idle_timeout>`.
+
+Handlers of this event will be passed a pointer to the iface that timed out attempting to associate.
+
 .. _conn_mgr_control_events_listening:
 
 Listening for control events

drivers/net/nsos_sockets.c

@@ -62,6 +62,9 @@ struct nsos_socket {
 
 static sys_dlist_t nsos_polls = SYS_DLIST_STATIC_INIT(&nsos_polls);
 
+/* Forward declaration of the interface */
+NET_IF_DECLARE(nsos_socket, 0);
+
 static int socket_family_to_nsos_mid(int family, int *family_mid)
 {
 	switch (family) {
@@ -693,6 +696,7 @@ static int nsos_connect_blocking(struct nsos_socket *sock,
 
 static int nsos_connect(void *obj, const struct sockaddr *addr, socklen_t addrlen)
 {
+	struct net_if *iface = NET_IF_GET(nsos_socket, 0);
 	struct nsos_socket *sock = obj;
 	struct nsos_mid_sockaddr_storage addr_storage_mid;
 	struct nsos_mid_sockaddr *addr_mid = (struct nsos_mid_sockaddr *)&addr_storage_mid;
@@ -718,6 +722,7 @@ static int nsos_connect(void *obj, const struct sockaddr *addr, socklen_t addrle
 		errno = nsi_errno_from_mid(-ret);
 		return -1;
 	}
+	conn_mgr_if_used(iface);
 
 	return ret;
 }
@@ -738,6 +743,7 @@ static int nsos_listen(void *obj, int backlog)
 
 static int nsos_accept(void *obj, struct sockaddr *addr, socklen_t *addrlen)
 {
+	struct net_if *iface = NET_IF_GET(nsos_socket, 0);
 	struct nsos_socket *accept_sock = obj;
 	struct nsos_mid_sockaddr_storage addr_storage_mid;
 	struct nsos_mid_sockaddr *addr_mid = (struct nsos_mid_sockaddr *)&addr_storage_mid;
@@ -782,6 +788,7 @@ static int nsos_accept(void *obj, struct sockaddr *addr, socklen_t *addrlen)
 
 	zvfs_finalize_typed_fd(zephyr_fd, conn_sock, &nsos_socket_fd_op_vtable.fd_vtable,
 			       ZVFS_MODE_IFSOCK);
+	conn_mgr_if_used(iface);
 
 	return zephyr_fd;
 
@@ -799,6 +806,7 @@ static int nsos_accept(void *obj, struct sockaddr *addr, socklen_t *addrlen)
 static ssize_t nsos_sendto(void *obj, const void *buf, size_t len, int flags,
 			   const struct sockaddr *addr, socklen_t addrlen)
 {
+	struct net_if *iface = NET_IF_GET(nsos_socket, 0);
 	struct nsos_socket *sock = obj;
 	struct nsos_mid_sockaddr_storage addr_storage_mid;
 	struct nsos_mid_sockaddr *addr_mid = (struct nsos_mid_sockaddr *)&addr_storage_mid;
@@ -832,11 +840,13 @@ static ssize_t nsos_sendto(void *obj, const void *buf, size_t len, int flags,
 		return -1;
 	}
 
+	conn_mgr_if_used(iface);
 	return ret;
 }
 
 static ssize_t nsos_sendmsg(void *obj, const struct msghdr *msg, int flags)
 {
+	struct net_if *iface = NET_IF_GET(nsos_socket, 0);
 	struct nsos_socket *sock = obj;
 	struct nsos_mid_sockaddr_storage addr_storage_mid;
 	struct nsos_mid_sockaddr *addr_mid = (struct nsos_mid_sockaddr *)&addr_storage_mid;
@@ -893,12 +903,14 @@ static ssize_t nsos_sendmsg(void *obj, const struct msghdr *msg, int flags)
 		return -1;
 	}
 
+	conn_mgr_if_used(iface);
 	return ret;
 }
 
 static ssize_t nsos_recvfrom(void *obj, void *buf, size_t len, int flags,
 			     struct sockaddr *addr, socklen_t *addrlen)
 {
+	struct net_if *iface = NET_IF_GET(nsos_socket, 0);
 	struct nsos_socket *sock = obj;
 	struct nsos_mid_sockaddr_storage addr_storage_mid;
 	struct nsos_mid_sockaddr *addr_mid = (struct nsos_mid_sockaddr *)&addr_storage_mid;
@@ -932,6 +944,7 @@ static ssize_t nsos_recvfrom(void *obj, void *buf, size_t len, int flags,
 		return -1;
 	}
 
+	conn_mgr_if_used(iface);
 	return ret;
 }
 
@@ -1492,6 +1505,7 @@ static int nsos_getaddrinfo(const char *node, const char *service,
 			    const struct zsock_addrinfo *hints,
 			    struct zsock_addrinfo **res)
 {
+	struct net_if *iface = NET_IF_GET(nsos_socket, 0);
 	struct nsos_mid_addrinfo hints_mid;
 	struct nsos_mid_addrinfo *res_mid;
 	int system_errno;
@@ -1525,6 +1539,7 @@ static int nsos_getaddrinfo(const char *node, const char *service,
 		errno = -ret;
 		return DNS_EAI_SYSTEM;
 	}
+	conn_mgr_if_used(iface);
 
 	return ret;
 }
@@ -1651,6 +1666,14 @@ static int nsos_net_if_disconnect(struct conn_mgr_conn_binding *const binding)
 	LOG_INF("NSOS: dormant");
 	k_work_cancel_delayable(&data->work);
 	net_if_dormant_on(binding->iface);
+
+	if (conn_mgr_binding_get_flag(binding, CONN_MGR_IF_PERSISTENT) &&
+	    !conn_mgr_binding_get_flag(binding, CONN_MGR_IF_DISCONNECTING)) {
+		/* Interface marked as persistent, application didn't request the disconnect */
+		LOG_INF("NSOS: reconnecting");
+		k_work_reschedule(&data->work, data->connect_delay);
+	}
+
 	return 0;
 }
 

include/zephyr/net/conn_mgr_connectivity.h

@@ -44,6 +44,7 @@ extern "C" {
 enum {
 	NET_EVENT_CONN_CMD_IF_TIMEOUT_VAL,
 	NET_EVENT_CONN_CMD_IF_FATAL_ERROR_VAL,
+	NET_EVENT_CONN_CMD_IF_IDLE_TIMEOUT_VAL,
 
 	NET_EVENT_CONN_CMD_MAX
 };
@@ -54,6 +55,7 @@ BUILD_ASSERT(NET_EVENT_CONN_CMD_MAX <= NET_MGMT_MAX_COMMANDS,
 enum net_event_conn_cmd {
 	NET_MGMT_CMD(NET_EVENT_CONN_CMD_IF_TIMEOUT),
 	NET_MGMT_CMD(NET_EVENT_CONN_CMD_IF_FATAL_ERROR),
+	NET_MGMT_CMD(NET_EVENT_CONN_CMD_IF_IDLE_TIMEOUT),
 };
 
 /** @endcond */
@@ -70,6 +72,12 @@ enum net_event_conn_cmd {
 #define NET_EVENT_CONN_IF_FATAL_ERROR					\
 	(NET_MGMT_CONN_IF_EVENT | NET_EVENT_CONN_CMD_IF_FATAL_ERROR)
 
+/**
+ * @brief net_mgmt event raised when an interface times out due to inactivity
+ */
+#define NET_EVENT_CONN_IF_IDLE_TIMEOUT					\
+	(NET_MGMT_CONN_IF_EVENT | NET_EVENT_CONN_CMD_IF_IDLE_TIMEOUT)
+
 
 /**
  * @brief Per-iface connectivity flags
@@ -264,6 +272,45 @@ int conn_mgr_if_get_timeout(struct net_if *iface);
  */
 int conn_mgr_if_set_timeout(struct net_if *iface, int timeout);
 
+/**
+ * @brief Get the idle timeout for an iface
+ *
+ * If the provided iface is bound to a connectivity implementation, retrieves the idle timeout
+ * setting in seconds for it.
+ *
+ * @param iface - Pointer to the iface to check.
+ * @return int - The connectivity timeout value (in seconds) if it could be retrieved, otherwise
+ *		 CONN_MGR_IF_NO_TIMEOUT.
+ */
+int conn_mgr_if_get_idle_timeout(struct net_if *iface);
+
+/**
+ * @brief Set the idle timeout for an iface.
+ *
+ * If the provided iface is bound to a connectivity implementation, sets the idle timeout setting
+ * in seconds for it.
+ *
+ * @param iface - Pointer to the network interface to modify.
+ * @param timeout - The timeout value to set (in seconds).
+ *		    Pass @ref CONN_MGR_IF_NO_TIMEOUT to disable the timeout.
+ * @retval 0 on success.
+ * @retval -ENOTSUP if the provided iface is not bound to a connectivity implementation.
+ */
+int conn_mgr_if_set_idle_timeout(struct net_if *iface, int timeout);
+
+#if defined(CONFIG_NET_CONNECTION_MANAGER) || defined(__DOXYGEN__)
+/**
+ * @brief Notify connection manager that interface was just used
+ *
+ * @note Typically called from network drivers, not application software.
+ *
+ * @param iface iface that was just used
+ */
+void conn_mgr_if_used(struct net_if *iface);
+#else
+#define conn_mgr_if_used(iface) (void)(iface)
+#endif /* defined(CONFIG_NET_CONNECTION_MANAGER) || defined(__DOXYGEN__) */
+
 /**
  * @}
  */

include/zephyr/net/conn_mgr_connectivity_impl.h

@@ -193,9 +193,22 @@ struct conn_mgr_conn_binding {
 	 */
 	int timeout;
 
+	/**
+	 * Usage timeout (seconds)
+	 *
+	 * Indicates to the connectivity implementation how long the interface can be idle
+	 * for before automatically taking the interface down.
+	 *
+	 * Set to @ref CONN_MGR_IF_NO_TIMEOUT to indicate that no idle timeout should be used.
+	 */
+	int idle_timeout;
+
 	/** @} */
 
 /** @cond INTERNAL_HIDDEN */
+	/* Internal-use work item for tracking interface idle timeouts */
+	struct k_work_delayable idle_worker;
+
 	/* Internal-use mutex for protecting access to the binding and API functions. */
 	struct k_mutex *mutex;
 /** @endcond */

include/zephyr/net/net_if.h

@@ -3495,6 +3495,16 @@ extern int net_stats_prometheus_scrape(struct prometheus_collector *collector,
 
 /* Network device initialization macros */
 
+/**
+ * @brief Forward declaration of a network interface
+ *
+ * Enables to use of `NET_IF_GET` above the instantiation macro.
+ *
+ * @param dev_id Device ID provided to `NET_IF_INIT` or `NET_IF_OFFLOAD_INIT`
+ */
+#define NET_IF_DECLARE(dev_id, inst) \
+	static struct net_if NET_IF_GET_NAME(dev_id, inst)[NET_IF_MAX_CONFIGS]
+
 #define Z_NET_DEVICE_INIT_INSTANCE(node_id, dev_id, name, instance,	\
 				   init_fn, pm, data, config, prio,	\
 				   api, l2, l2_ctx_type, mtu)		\