samples: wifi: implement state machine to handle reconnects

Implement WiFi connectivity state machine running in a dedicated work
queue (which runs in a dedicated thread). Network management events from
Zephyr are handled there, as well as timeouts and retries when attempting
to connect. As a result, WiFi connectivity is bringed back whenever there
was a temporary problem with WiFi AP connection.

In case WiFi radio is not ready (L1 is down, which results in LOWER_DOWN
interface management event/state) wait until it becomes ready (which is
required by ESP32 WiFi driver, since it does not handle connect requests
otherwise).

Signed-off-by: Marcin Niestroj <[email protected]>

samples/common/Kconfig

@@ -103,6 +103,18 @@ config GOLIOTH_SAMPLE_WIFI
 	help
 	  Enable utilities for easy WiFi setup, mainly for use inside samples/.
 
+if GOLIOTH_SAMPLE_WIFI
+
+config GOLIOTH_SAMPLE_WIFI_STACK_SIZE
+	int "WiFi manager stack size"
+	default 2048
+
+config GOLIOTH_SAMPLE_WIFI_INIT_PRIORITY
+	int "WiFi manager init priority"
+	default 90
+
+endif # GOLIOTH_SAMPLE_WIFI
+
 config GOLIOTH_SAMPLE_WIFI_SETTINGS
 	bool "Load SSID and PSK from settigs subsystem"
 	depends on GOLIOTH_SAMPLE_WIFI

samples/common/net_connect.c

@@ -8,7 +8,6 @@
 LOG_MODULE_REGISTER(golioth_samples, LOG_LEVEL_DBG);
 
 #include <samples/common/net_connect.h>
-#include <samples/common/wifi.h>
 #include <zephyr/net/net_if.h>
 #include <zephyr/net/dhcpv4.h>
 
@@ -28,65 +27,30 @@ static void event_cb_handler(struct net_mgmt_event_callback *cb,
 	}
 }
 
-static void wait_for_iface_up_event(struct net_if *iface)
+static void wait_for_net_event(struct net_if *iface, uint32_t event)
 {
 	struct wait_data wait;
 
 	wait.cb.handler = event_cb_handler;
-	wait.cb.event_mask = NET_EVENT_IF_UP;
+	wait.cb.event_mask = event;
 
 	k_sem_init(&wait.sem, 0, 1);
 	net_mgmt_add_event_callback(&wait.cb);
 
-	if (!net_if_is_up(iface)) {
-		k_sem_take(&wait.sem, K_FOREVER);
-	}
+	k_sem_take(&wait.sem, K_FOREVER);
 
 	net_mgmt_del_event_callback(&wait.cb);
 }
 
-static void wait_for_iface_up_poll(struct net_if *iface)
-{
-	while (!net_if_is_up(iface)) {
-		LOG_DBG("Interface is not up yet!");
-		k_sleep(K_MSEC(100));
-	}
-}
-
-static void wait_for_iface_up(struct net_if *iface)
-{
-	if (IS_ENABLED(CONFIG_NET_MGMT_EVENT)) {
-		wait_for_iface_up_event(iface);
-	} else {
-		wait_for_iface_up_poll(iface);
-	}
-}
-
-static void wait_for_dhcp_bound(struct net_if *iface)
-{
-	(void)net_mgmt_event_wait_on_iface(iface, NET_EVENT_IPV4_DHCP_BOUND,
-					   NULL, NULL, NULL,
-					   K_FOREVER);
-}
-
 void net_connect(void)
 {
 	struct net_if *iface = net_if_get_default();
 
-	if (!(IS_ENABLED(CONFIG_GOLIOTH_SAMPLE_WIFI) &&
-	      net_if_flag_is_set(iface, NET_IF_DORMANT))) {
-		LOG_INF("Waiting for interface to be up");
-		wait_for_iface_up(iface);
-	}
-
-	if (IS_ENABLED(CONFIG_GOLIOTH_SAMPLE_WIFI)) {
-		LOG_INF("Connecting to WiFi");
-		wifi_connect(iface);
-	}
-
 	if (IS_ENABLED(CONFIG_GOLIOTH_SAMPLE_DHCP_BIND)) {
 		LOG_INF("Starting DHCP to obtain IP address");
 		net_dhcpv4_start(iface);
-		wait_for_dhcp_bound(iface);
 	}
+
+	LOG_INF("Waiting to obtain IP address");
+	wait_for_net_event(iface, NET_EVENT_IPV4_ADDR_ADD);
 }