first commit

main/wifi/wifi_manager.c

@@ -0,0 +1,156 @@
+#include <string.h>
+
+#include "esp_event.h"
+#include "esp_log.h"
+#include "esp_netif.h"
+#include "esp_system.h"
+#include "esp_wifi.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/event_groups.h"
+#include "nvs_flash.h"
+
+#include "app_config.h"
+#include "wifi_manager.h"
+
+static const char *TAG = "wifi_manager";
+
+#define WIFI_CONNECTED_BIT BIT0
+#define WIFI_FAIL_BIT      BIT1
+#define WIFI_MAX_RETRIES   8
+#define WIFI_CONNECT_TIMEOUT_MS 30000
+
+static EventGroupHandle_t s_wifi_event_group = NULL;
+static int s_retry_count = 0;
+
+static void wifi_event_handler(void *arg, esp_event_base_t event_base,
+                               int32_t event_id, void *event_data)
+{
+    if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_START) {
+        esp_wifi_connect();
+        return;
+    }
+
+    if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_DISCONNECTED) {
+        /*
+         * Only give up after a bounded number of retries. Signalling failure
+         * on the first disconnect (as this previously did) meant a single
+         * transient drop was reported as a hard failure.
+         */
+        if (s_retry_count < WIFI_MAX_RETRIES) {
+            s_retry_count++;
+            ESP_LOGW(TAG, "Disconnected, retry %d/%d", s_retry_count, WIFI_MAX_RETRIES);
+            esp_wifi_connect();
+        } else {
+            ESP_LOGE(TAG, "Giving up after %d retries", WIFI_MAX_RETRIES);
+            xEventGroupSetBits(s_wifi_event_group, WIFI_FAIL_BIT);
+        }
+        return;
+    }
+
+    if (event_base == IP_EVENT && event_id == IP_EVENT_STA_GOT_IP) {
+        const ip_event_got_ip_t *event = (const ip_event_got_ip_t *)event_data;
+        ESP_LOGI(TAG, "Got IP: " IPSTR, IP2STR(&event->ip_info.ip));
+        s_retry_count = 0;
+        xEventGroupSetBits(s_wifi_event_group, WIFI_CONNECTED_BIT);
+    }
+}
+
+esp_err_t wifi_init_sta(void)
+{
+    if (WIFI_SSID[0] == '\0') {
+        ESP_LOGE(TAG, "WIFI_SSID is empty -- set it in main/app_config.h");
+        return ESP_ERR_INVALID_STATE;
+    }
+
+    s_wifi_event_group = xEventGroupCreate();
+    if (s_wifi_event_group == NULL) {
+        return ESP_ERR_NO_MEM;
+    }
+
+    esp_err_t ret = nvs_flash_init();
+    if (ret == ESP_ERR_NVS_NO_FREE_PAGES || ret == ESP_ERR_NVS_NEW_VERSION_FOUND) {
+        ESP_ERROR_CHECK(nvs_flash_erase());
+        ret = nvs_flash_init();
+    }
+    ESP_ERROR_CHECK(ret);
+
+    /* The TCP/IP stack and the default STA netif were never set up here, so
+     * IP_EVENT_STA_GOT_IP could never fire and every connect timed out. */
+    ESP_ERROR_CHECK(esp_netif_init());
+    ESP_ERROR_CHECK(esp_event_loop_create_default());
+    esp_netif_create_default_wifi_sta();
+
+    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
+    ESP_ERROR_CHECK(esp_wifi_init(&cfg));
+
+    ESP_ERROR_CHECK(esp_event_handler_instance_register(WIFI_EVENT, ESP_EVENT_ANY_ID,
+                                                        &wifi_event_handler, NULL, NULL));
+    ESP_ERROR_CHECK(esp_event_handler_instance_register(IP_EVENT, IP_EVENT_STA_GOT_IP,
+                                                        &wifi_event_handler, NULL, NULL));
+
+    /* wifi_config_t.sta.ssid is a uint8_t array; it cannot be initialised
+     * from a string literal in a designated initialiser. */
+    wifi_config_t wifi_config = {
+        .sta = {
+            .threshold.authmode = WIFI_AUTH_WPA2_PSK,
+            .sae_pwe_h2e = WPA3_SAE_PWE_BOTH,
+        },
+    };
+    strlcpy((char *)wifi_config.sta.ssid, WIFI_SSID, sizeof(wifi_config.sta.ssid));
+    strlcpy((char *)wifi_config.sta.password, WIFI_PASSWORD,
+            sizeof(wifi_config.sta.password));
+
+    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
+    ESP_ERROR_CHECK(esp_wifi_set_config(WIFI_IF_STA, &wifi_config));
+    ESP_ERROR_CHECK(esp_wifi_start());
+
+    /* Modem sleep adds hundreds of ms of latency per round trip, which is
+     * enough to push a TLS handshake past its timeout on this board. */
+    ESP_ERROR_CHECK(esp_wifi_set_ps(WIFI_PS_NONE));
+
+    const EventBits_t bits = xEventGroupWaitBits(
+        s_wifi_event_group,
+        WIFI_CONNECTED_BIT | WIFI_FAIL_BIT,
+        pdFALSE, pdFALSE,
+        pdMS_TO_TICKS(WIFI_CONNECT_TIMEOUT_MS));
+
+    if (bits & WIFI_CONNECTED_BIT) {
+        ESP_LOGI(TAG, "Connected to SSID: %s", WIFI_SSID);
+        return ESP_OK;
+    }
+
+    if (bits & WIFI_FAIL_BIT) {
+        ESP_LOGE(TAG, "Failed to connect to SSID: %s", WIFI_SSID);
+        return ESP_FAIL;
+    }
+
+    ESP_LOGE(TAG, "Timed out waiting for WiFi connection");
+    return ESP_ERR_TIMEOUT;
+}
+
+bool wifi_is_connected(void)
+{
+    if (s_wifi_event_group == NULL) {
+        return false;
+    }
+    return (xEventGroupGetBits(s_wifi_event_group) & WIFI_CONNECTED_BIT) != 0;
+}
+
+void wifi_get_status(char *buf, size_t len)
+{
+    if (buf == NULL || len == 0) {
+        return;
+    }
+
+    if (!wifi_is_connected()) {
+        snprintf(buf, len, "WiFi: not connected");
+        return;
+    }
+
+    wifi_ap_record_t ap;
+    if (esp_wifi_sta_get_ap_info(&ap) == ESP_OK) {
+        snprintf(buf, len, "WiFi: %s (%d dBm)", (char *)ap.ssid, ap.rssi);
+    } else {
+        snprintf(buf, len, "WiFi: connected");
+    }
+}

main/wifi/wifi_manager.h

@@ -0,0 +1,14 @@
+#ifndef WIFI_MANAGER_H
+#define WIFI_MANAGER_H
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+
+#include "esp_err.h"
+
+esp_err_t wifi_init_sta(void);
+bool wifi_is_connected(void);
+void wifi_get_status(char *buf, size_t len);
+
+#endif