samples: net: echo-client: Check IPv6 address deprecation

If the IPv6 address that our socket is bound to deprecates, then
re-create the socket so that we avoid using deprecated IPv6 address.

Signed-off-by: Jukka Rissanen <jukka.rissanen@nordicsemi.no>

samples/net/sockets/echo_client/src/echo-client.c

@@ -24,6 +24,8 @@ LOG_MODULE_REGISTER(net_echo_client_sample, LOG_LEVEL_DBG);
 #include <errno.h>
 #include <stdio.h>
 
+#include <zephyr/posix/sys/eventfd.h>
+
 #include <zephyr/net/socket.h>
 #include <zephyr/net/tls_credentials.h>
 
@@ -46,6 +48,8 @@ struct k_mem_domain app_domain;
 
 #define EVENT_MASK (NET_EVENT_L4_CONNECTED | \
 		    NET_EVENT_L4_DISCONNECTED)
+#define IPV6_EVENT_MASK (NET_EVENT_IPV6_ADDR_ADD | \
+			 NET_EVENT_IPV6_ADDR_DEPRECATED)
 
 /* Generated by http://www.lipsum.com/
  * 2 paragraphs, 179 words, 1160 bytes of Lorem Ipsum
@@ -87,16 +91,26 @@ APP_DMEM struct configs conf = {
 	},
 };
 
-static APP_BMEM struct pollfd fds[4];
+static APP_BMEM struct pollfd fds[1 + 4];
 static APP_BMEM int nfds;
 
 static APP_BMEM bool connected;
+static APP_BMEM bool need_restart;
+
 K_SEM_DEFINE(run_app, 0, 1);
 
 static struct net_mgmt_event_callback mgmt_cb;
+static struct net_mgmt_event_callback ipv6_mgmt_cb;
 
 static void prepare_fds(void)
 {
+	nfds = 0;
+
+	/* eventfd is used to trigger restart */
+	fds[nfds].fd = eventfd(0, 0);
+	fds[nfds].events = POLLIN;
+	nfds++;
+
 	if (conf.ipv4.udp.sock >= 0) {
 		fds[nfds].fd = conf.ipv4.udp.sock;
 		fds[nfds].events = POLLIN;
@@ -124,11 +138,29 @@ static void prepare_fds(void)
 
 static void wait(void)
 {
+	int ret;
+
 	/* Wait for event on any socket used. Once event occurs,
 	 * we'll check them all.
 	 */
-	if (poll(fds, nfds, -1) < 0) {
+	ret = poll(fds, nfds, -1);
-		LOG_ERR("Error in poll:%d", errno);
+	if (ret < 0) {
+		static bool once;
+
+		if (!once) {
+			once = true;
+			LOG_ERR("Error in poll:%d", errno);
+		}
+
+		return;
+	}
+
+	if (ret > 0 && fds[0].revents) {
+		eventfd_t value;
+
+		eventfd_read(fds[0].fd, &value);
+		LOG_DBG("Received restart event.");
+		return;
 	}
 }
 
@@ -193,6 +225,99 @@ static void stop_udp_and_tcp(void)
 	}
 }
 
+static int check_our_ipv6_sockets(int sock,
+				  struct in6_addr *deprecated_addr)
+{
+	struct sockaddr_in6 addr = { 0 };
+	socklen_t addrlen = sizeof(addr);
+	int ret;
+
+	if (sock < 0) {
+		return -EINVAL;
+	}
+
+	ret = getsockname(sock, (struct sockaddr *)&addr, &addrlen);
+	if (ret != 0) {
+		return -errno;
+	}
+
+	if (!net_ipv6_addr_cmp(deprecated_addr, &addr.sin6_addr)) {
+		return -ENOENT;
+	}
+
+	need_restart = true;
+
+	return 0;
+}
+
+static void ipv6_event_handler(struct net_mgmt_event_callback *cb,
+			       uint32_t mgmt_event, struct net_if *iface)
+{
+	static char addr_str[INET6_ADDRSTRLEN];
+
+	if (!IS_ENABLED(CONFIG_NET_IPV6_PE)) {
+		return;
+	}
+
+	if ((mgmt_event & IPV6_EVENT_MASK) != mgmt_event) {
+		return;
+	}
+
+	if (cb->info == NULL ||
+	    cb->info_length != sizeof(struct in6_addr)) {
+		return;
+	}
+
+	if (mgmt_event == NET_EVENT_IPV6_ADDR_ADD) {
+		struct net_if_addr *ifaddr;
+		struct in6_addr added_addr;
+
+		memcpy(&added_addr, cb->info, sizeof(struct in6_addr));
+
+		ifaddr = net_if_ipv6_addr_lookup(&added_addr, &iface);
+		if (ifaddr == NULL) {
+			return;
+		}
+
+		/* Wait until we get a temporary address before continuing after
+		 * boot.
+		 */
+		if (ifaddr->is_temporary) {
+			static bool once;
+
+			LOG_INF("Temporary IPv6 address %s added",
+				inet_ntop(AF_INET6, &added_addr, addr_str,
+					  sizeof(addr_str) - 1));
+
+			if (!once) {
+				k_sem_give(&run_app);
+				once = true;
+			}
+		}
+	}
+
+	if (mgmt_event == NET_EVENT_IPV6_ADDR_DEPRECATED) {
+		struct in6_addr deprecated_addr;
+
+		memcpy(&deprecated_addr, cb->info, sizeof(struct in6_addr));
+
+		LOG_INF("IPv6 address %s deprecated",
+			inet_ntop(AF_INET6, &deprecated_addr, addr_str,
+				  sizeof(addr_str) - 1));
+
+		(void)check_our_ipv6_sockets(conf.ipv6.tcp.sock,
+					     &deprecated_addr);
+		(void)check_our_ipv6_sockets(conf.ipv6.udp.sock,
+					     &deprecated_addr);
+
+		if (need_restart) {
+			eventfd_write(fds[0].fd, 1);
+		}
+
+		return;
+	}
+}
+
 static void event_handler(struct net_mgmt_event_callback *cb,
 			  uint32_t mgmt_event, struct net_if *iface)
 {
@@ -206,7 +331,10 @@ static void event_handler(struct net_mgmt_event_callback *cb,
 		connected = true;
 		conf.ipv4.udp.mtu = net_if_get_mtu(iface);
 		conf.ipv6.udp.mtu = conf.ipv4.udp.mtu;
-		k_sem_give(&run_app);
+
+		if (!IS_ENABLED(CONFIG_NET_IPV6_PE)) {
+			k_sem_give(&run_app);
+		}
 
 		return;
 	}
@@ -275,6 +403,10 @@ static void init_app(void)
 		conn_mgr_mon_resend_status();
 	}
 
+	net_mgmt_init_event_callback(&ipv6_mgmt_cb,
+				     ipv6_event_handler, IPV6_EVENT_MASK);
+	net_mgmt_add_event_callback(&ipv6_mgmt_cb);
+
 	init_vlan();
 	init_udp();
 }
@@ -293,19 +425,35 @@ static void start_client(void *p1, void *p2, void *p3)
 		/* Wait for the connection. */
 		k_sem_take(&run_app, K_FOREVER);
 
-		ret = start_udp_and_tcp();
+		if (IS_ENABLED(CONFIG_NET_IPV6_PE)) {
+			/* Make sure that we have a temporary address */
+			k_sleep(K_SECONDS(1));
+		}
 
-		while (connected && (ret == 0)) {
+		do {
-			ret = run_udp_and_tcp();
+			if (need_restart) {
+				/* Close all sockets and get a fresh restart */
+				stop_udp_and_tcp();
+				need_restart = false;
+			}
 
-			if (iterations > 0) {
+			ret = start_udp_and_tcp();
-				i++;
+
-				if (i >= iterations) {
+			while (connected && (ret == 0)) {
+				ret = run_udp_and_tcp();
+
+				if (iterations > 0) {
+					i++;
+					if (i >= iterations) {
+						break;
+					}
+				}
+
+				if (need_restart) {
 					break;
-
 				}
 			}
-		}
+		} while (need_restart);
 
 		stop_udp_and_tcp();
 	}

samples/net/sockets/echo_client/src/tcp.c

@@ -239,7 +239,8 @@ int start_tcp(void)
 		inet_pton(AF_INET6, CONFIG_NET_CONFIG_PEER_IPV6_ADDR,
 			  &addr6.sin6_addr);
 
-		ret = start_tcp_proto(&conf.ipv6, (struct sockaddr *)&addr6,
+		ret = start_tcp_proto(&conf.ipv6,
+				      (struct sockaddr *)&addr6,
 				      sizeof(addr6));
 		if (ret < 0) {
 			return ret;

samples/net/sockets/echo_client/src/udp.c

@@ -308,7 +308,8 @@ int start_udp(void)
 		inet_pton(AF_INET6, CONFIG_NET_CONFIG_PEER_IPV6_ADDR,
 			  &addr6.sin6_addr);
 
-		ret = start_udp_proto(&conf.ipv6, (struct sockaddr *)&addr6,
+		ret = start_udp_proto(&conf.ipv6,
+				      (struct sockaddr *)&addr6,
 				      sizeof(addr6));
 		if (ret < 0) {
 			return ret;