examples:Added example for NAT from Wifi AP to STA.

examples/wifi/README.md

@@ -1,3 +1,6 @@
+| Supported Targets | ESP32 | ESP32-C2 | ESP32-C3 | ESP32-C6 | ESP32-S2 | ESP32-S3 |
+| ----------------- | ----- | -------- | -------- | -------- | -------- | -------- |
+
 # Wi-Fi Examples
 
 This directory contains a range of examples ESP-IDF projects. These are intended to demonstrate the Wi-Fi functionality, and to provide code that you can copy and adapt into your own projects.

examples/wifi/softap_sta/CMakeLists.txt

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+# For more information about build system see
+# https://docs.espressif.com/projects/esp-idf/en/latest/api-guides/build-system.html
+# The following five lines of boilerplate have to be in your project's
+# CMakeLists in this exact order for cmake to work correctly
+cmake_minimum_required(VERSION 3.16)
+
+include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+project(softap_sta)

examples/wifi/softap_sta/README.md

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+| Supported Targets | ESP32 | ESP32-C2 | ESP32-C3 | ESP32-C6 | ESP32-S2 | ESP32-S3 |
+| ----------------- | ----- | -------- | -------- | -------- | -------- | -------- |
+
+# Wi-Fi SoftAP & Station Example
+
+(See the README.md file in the upper level 'examples' directory for more information about examples.)
+
+This example demonstrates how to use the ESP Wi-Fi driver to act as both an Access Point and a Station simultaneously using the SoftAP and Station features.
+With NAPT enabled on the softAP interface and the station interface set as the defaut interface this example can be used as Wifi nat router.
+
+## How to use example
+### Configure the project
+
+Open the project configuration menu (`idf.py menuconfig`).
+
+In the `Example Configuration` menu:
+
+* Set the Wi-Fi SoftAP configuration.
+    * Set `WiFi AP SSID`.
+    * Set `WiFi AP Password`.
+
+* Set the Wi-Fi STA configuration.
+    * Set `WiFi Remote AP SSID`.
+    * Set `WiFi Remote AP Password`.
+
+Optional: If necessary, modify the other choices to suit your needs.
+
+### Build and Flash
+
+Build the project and flash it to the board, then run the monitor tool to view the serial output:
+
+Run `idf.py -p PORT flash monitor` to build, flash and monitor the project.
+
+(To exit the serial monitor, type ``Ctrl-]``.)
+
+## Example Output
+
+There is the console output for this example:
+
+```
+I (680) WiFi SoftAP: ESP_WIFI_MODE_AP
+I (690) WiFi SoftAP: wifi_init_softap finished. SSID:myssid password:mypassword channel:1
+I (690) WiFi Sta: ESP_WIFI_MODE_STA
+I (690) WiFi Sta: wifi_init_sta finished.
+I (700) phy_init: phy_version 4670,719f9f6,Feb 18 2021,17:07:07
+I (800) wifi:mode : sta (58:bf:25:e0:41:00) + softAP (58:bf:25:e0:41:01)
+I (800) wifi:enable tsf
+I (810) wifi:Total power save buffer number: 16
+I (810) wifi:Init max length of beacon: 752/752
+I (810) wifi:Init max length of beacon: 752/752
+I (820) WiFi Sta: Station started
+I (820) wifi:new:<1,1>, old:<1,1>, ap:<1,1>, sta:<1,1>, prof:1
+I (820) wifi:state: init -> auth (b0)
+I (830) wifi:state: auth -> assoc (0)
+E (840) wifi:Association refused temporarily, comeback time 1536 mSec
+I (2380) wifi:state: assoc -> assoc (0)
+I (2390) wifi:state: assoc -> run (10)
+I (2400) wifi:connected with myssid_c3, aid = 1, channel 1, 40U, bssid = 84:f7:03:60:86:1d
+I (2400) wifi:security: WPA2-PSK, phy: bgn, rssi: -14
+I (2410) wifi:pm start, type: 1
+
+I (2410) wifi:AP's beacon interval = 102400 us, DTIM period = 2
+I (3920) WiFi Sta: Got IP:192.168.5.2
+I (3920) esp_netif_handlers: sta ip: 192.168.5.2, mask: 255.255.255.0, gw: 192.168.5.1
+I (3920) WiFi Sta: connected to ap SSID:myssid_c3 password:mypassword_c3
+```
+
+## Troubleshooting
+
+For any technical queries, please open an [issue](https://github.com/espressif/esp-idf/issues) on GitHub. We will get back to you soon.

examples/wifi/softap_sta/main/CMakeLists.txt

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+idf_component_register(SRCS "softap_sta.c"
+                    INCLUDE_DIRS ".")

examples/wifi/softap_sta/main/Kconfig.projbuild

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+menu "Example Configuration"
+
+    menu "SoftAP Configuration"
+        comment "SoftAP Configuration"
+
+        config ESP_WIFI_AP_SSID
+            string "WiFi AP SSID"
+            default "myssid"
+            help
+                SSID (network name) of the AP for the example to connect to.
+
+        config ESP_WIFI_AP_PASSWORD
+            string "WiFi AP Password"
+            default "mypassword"
+            help
+                WiFi password of the AP for the example to use.
+
+        config ESP_WIFI_AP_CHANNEL
+            int "WiFi AP Channel"
+            range 1 14
+            default 1
+            help
+                WiFi channel (network channel) of the AP for the example to use.
+
+        config ESP_MAX_STA_CONN_AP
+            int "Maximal STA connections"
+            default 4
+            help
+                Max number of the STA connects to AP.
+    endmenu
+
+    menu "STA Configuration"
+        comment "STA Configuration"
+
+        config ESP_WIFI_REMOTE_AP_SSID
+            string "WiFi Remote AP SSID"
+            default "otherapssid"
+            help
+                SSID (network name) for the example's sta to connect to.
+
+        config ESP_WIFI_REMOTE_AP_PASSWORD
+            string "WiFi Remote AP Password"
+            default "otherappassword"
+            help
+                WiFi password for the example to use.
+
+        config ESP_MAXIMUM_STA_RETRY
+            int "Maximum retry"
+            default 5
+            help
+                Set the maximum retry value to prevent the station from continuously
+                attempting to reconnect to the Access Point (AP) when the AP doesn't exist.
+
+        choice ESP_WIFI_SCAN_AUTH_MODE_THRESHOLD
+            prompt "WiFi Scan auth mode threshold"
+            default ESP_WIFI_AUTH_WPA2_PSK
+            help
+                The weakest authmode to accept in the scan mode.
+                This value defaults to ESP_WIFI_AUTH_WPA2_PSK incase password is present
+                and ESP_WIFI_AUTH_OPEN is used. Please select ESP_WIFI_AUTH_WEP / ESP_WIFI_AUTH_WPA_PSK
+                incase AP is operating in WEP / WPA mode.
+
+            config ESP_WIFI_AUTH_OPEN
+                bool "OPEN"
+            config ESP_WIFI_AUTH_WEP
+                bool "WEP"
+            config ESP_WIFI_AUTH_WPA_PSK
+                bool "WPA PSK"
+            config ESP_WIFI_AUTH_WPA2_PSK
+                bool "WPA2 PSK"
+            config ESP_WIFI_AUTH_WPA_WPA2_PSK
+                bool "WPA/WPA2 PSK"
+            config ESP_WIFI_AUTH_WPA3_PSK
+                bool "WPA3 PSK"
+            config ESP_WIFI_AUTH_WPA2_WPA3_PSK
+                bool "WPA2/WPA3 PSK"
+            config ESP_WIFI_AUTH_WAPI_PSK
+                bool "WAPI PSK"
+        endchoice
+
+    endmenu
+endmenu

examples/wifi/softap_sta/main/softap_sta.c

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+/*
+ * SPDX-FileCopyrightText: 2023 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+/*  WiFi softAP & station Example
+
+   This example code is in the Public Domain (or CC0 licensed, at your option.)
+
+   Unless required by applicable law or agreed to in writing, this
+   software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+   CONDITIONS OF ANY KIND, either express or implied.
+*/
+#include <string.h>
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "freertos/event_groups.h"
+#include "esp_mac.h"
+#include "esp_wifi.h"
+#include "esp_event.h"
+#include "esp_log.h"
+#include "esp_netif_net_stack.h"
+#include "esp_netif.h"
+#include "nvs_flash.h"
+#include "lwip/inet.h"
+#include "lwip/netdb.h"
+#include "lwip/sockets.h"
+#if IP_NAPT
+#include "lwip/lwip_napt.h"
+#endif
+#include "lwip/err.h"
+#include "lwip/sys.h"
+
+/* The examples use WiFi configuration that you can set via project configuration menu.
+
+   If you'd rather not, just change the below entries to strings with
+   the config you want - ie #define EXAMPLE_ESP_WIFI_STA_SSID "mywifissid"
+*/
+
+/* STA Configuration */
+#define EXAMPLE_ESP_WIFI_STA_SSID           CONFIG_ESP_WIFI_REMOTE_AP_SSID
+#define EXAMPLE_ESP_WIFI_STA_PASSWD         CONFIG_ESP_WIFI_REMOTE_AP_PASSWORD
+#define EXAMPLE_ESP_MAXIMUM_RETRY           CONFIG_ESP_MAXIMUM_STA_RETRY
+
+#if CONFIG_ESP_WIFI_AUTH_OPEN
+#define ESP_WIFI_SCAN_AUTH_MODE_THRESHOLD   WIFI_AUTH_OPEN
+#elif CONFIG_ESP_WIFI_AUTH_WEP
+#define ESP_WIFI_SCAN_AUTH_MODE_THRESHOLD   WIFI_AUTH_WEP
+#elif CONFIG_ESP_WIFI_AUTH_WPA_PSK
+#define ESP_WIFI_SCAN_AUTH_MODE_THRESHOLD   WIFI_AUTH_WPA_PSK
+#elif CONFIG_ESP_WIFI_AUTH_WPA2_PSK
+#define ESP_WIFI_SCAN_AUTH_MODE_THRESHOLD   WIFI_AUTH_WPA2_PSK
+#elif CONFIG_ESP_WIFI_AUTH_WPA_WPA2_PSK
+#define ESP_WIFI_SCAN_AUTH_MODE_THRESHOLD   WIFI_AUTH_WPA_WPA2_PSK
+#elif CONFIG_ESP_WIFI_AUTH_WPA3_PSK
+#define ESP_WIFI_SCAN_AUTH_MODE_THRESHOLD   WIFI_AUTH_WPA3_PSK
+#elif CONFIG_ESP_WIFI_AUTH_WPA2_WPA3_PSK
+#define ESP_WIFI_SCAN_AUTH_MODE_THRESHOLD   WIFI_AUTH_WPA2_WPA3_PSK
+#elif CONFIG_ESP_WIFI_AUTH_WAPI_PSK
+#define ESP_WIFI_SCAN_AUTH_MODE_THRESHOLD   WIFI_AUTH_WAPI_PSK
+#endif
+
+/* AP Configuration */
+#define EXAMPLE_ESP_WIFI_AP_SSID            CONFIG_ESP_WIFI_AP_SSID
+#define EXAMPLE_ESP_WIFI_AP_PASSWD          CONFIG_ESP_WIFI_AP_PASSWORD
+#define EXAMPLE_ESP_WIFI_CHANNEL            CONFIG_ESP_WIFI_AP_CHANNEL
+#define EXAMPLE_MAX_STA_CONN                CONFIG_ESP_MAX_STA_CONN_AP
+
+
+/* The event group allows multiple bits for each event, but we only care about two events:
+ * - we are connected to the AP with an IP
+ * - we failed to connect after the maximum amount of retries */
+#define WIFI_CONNECTED_BIT BIT0
+#define WIFI_FAIL_BIT      BIT1
+
+static const char *TAG_AP = "WiFi SoftAP";
+static const char *TAG_STA = "WiFi Sta";
+
+static int s_retry_num = 0;
+
+/* FreeRTOS event group to signal when we are connected/disconnected */
+static EventGroupHandle_t s_wifi_event_group;
+
+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_AP_STACONNECTED) {
+        wifi_event_ap_staconnected_t *event = (wifi_event_ap_staconnected_t *) event_data;
+        ESP_LOGI(TAG_AP, "Station "MACSTR" joined, AID=%d",
+                 MAC2STR(event->mac), event->aid);
+    } else if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_AP_STADISCONNECTED) {
+        wifi_event_ap_stadisconnected_t *event = (wifi_event_ap_stadisconnected_t *) event_data;
+        ESP_LOGI(TAG_AP, "Station "MACSTR" left, AID=%d",
+                 MAC2STR(event->mac), event->aid);
+    } else if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_START) {
+        esp_wifi_connect();
+        ESP_LOGI(TAG_STA, "Station started");
+    } else if (event_base == IP_EVENT && event_id == IP_EVENT_STA_GOT_IP) {
+        ip_event_got_ip_t *event = (ip_event_got_ip_t *) event_data;
+        ESP_LOGI(TAG_STA, "Got IP:" IPSTR, IP2STR(&event->ip_info.ip));
+        s_retry_num = 0;
+        xEventGroupSetBits(s_wifi_event_group, WIFI_CONNECTED_BIT);
+    }
+}
+
+/* Initialize soft AP */
+esp_netif_t *wifi_init_softap(void)
+{
+    esp_netif_t *esp_netif_ap = esp_netif_create_default_wifi_ap();
+
+    wifi_config_t wifi_ap_config = {
+        .ap = {
+            .ssid = EXAMPLE_ESP_WIFI_AP_SSID,
+            .ssid_len = strlen(EXAMPLE_ESP_WIFI_AP_SSID),
+            .channel = EXAMPLE_ESP_WIFI_CHANNEL,
+            .password = EXAMPLE_ESP_WIFI_AP_PASSWD,
+            .max_connection = EXAMPLE_MAX_STA_CONN,
+            .authmode = WIFI_AUTH_WPA2_PSK,
+            .pmf_cfg = {
+                .required = false,
+            },
+        },
+    };
+
+    if (strlen(EXAMPLE_ESP_WIFI_AP_PASSWD) == 0) {
+        wifi_ap_config.ap.authmode = WIFI_AUTH_OPEN;
+    }
+
+    ESP_ERROR_CHECK(esp_wifi_set_config(WIFI_IF_AP, &wifi_ap_config));
+
+    ESP_LOGI(TAG_AP, "wifi_init_softap finished. SSID:%s password:%s channel:%d",
+             EXAMPLE_ESP_WIFI_AP_SSID, EXAMPLE_ESP_WIFI_AP_PASSWD, EXAMPLE_ESP_WIFI_CHANNEL);
+
+    return esp_netif_ap;
+}
+
+/* Initialize wifi station */
+esp_netif_t *wifi_init_sta(void)
+{
+    esp_netif_t *esp_netif_sta = esp_netif_create_default_wifi_sta();
+
+    wifi_config_t wifi_sta_config = {
+        .sta = {
+            .ssid = EXAMPLE_ESP_WIFI_STA_SSID,
+            .password = EXAMPLE_ESP_WIFI_STA_PASSWD,
+            .scan_method = WIFI_ALL_CHANNEL_SCAN,
+            .failure_retry_cnt = EXAMPLE_ESP_MAXIMUM_RETRY,
+            /* Authmode threshold resets to WPA2 as default if password matches WPA2 standards (pasword len => 8).
+             * If you want to connect the device to deprecated WEP/WPA networks, Please set the threshold value
+             * to WIFI_AUTH_WEP/WIFI_AUTH_WPA_PSK and set the password with length and format matching to
+            * WIFI_AUTH_WEP/WIFI_AUTH_WPA_PSK standards.
+             */
+            .threshold.authmode = ESP_WIFI_SCAN_AUTH_MODE_THRESHOLD,
+            .sae_pwe_h2e = WPA3_SAE_PWE_BOTH,
+        },
+    };
+
+    ESP_ERROR_CHECK(esp_wifi_set_config(WIFI_IF_STA, &wifi_sta_config) );
+
+    ESP_LOGI(TAG_STA, "wifi_init_sta finished.");
+
+    return esp_netif_sta;
+}
+
+void app_main(void)
+{
+    ESP_ERROR_CHECK(esp_netif_init());
+    ESP_ERROR_CHECK(esp_event_loop_create_default());
+
+    //Initialize NVS
+    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);
+
+    /* Initialize event group */
+    s_wifi_event_group = xEventGroupCreate();
+
+    /* Register Event handler */
+    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));
+
+    /*Initialize WiFi */
+    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
+    ESP_ERROR_CHECK(esp_wifi_init(&cfg));
+
+    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_APSTA));
+
+    /* Initialize AP */
+    ESP_LOGI(TAG_AP, "ESP_WIFI_MODE_AP");
+    esp_netif_t *esp_netif_ap = wifi_init_softap();
+
+    /* Initialize STA */
+    ESP_LOGI(TAG_STA, "ESP_WIFI_MODE_STA");
+    esp_netif_t *esp_netif_sta = wifi_init_sta();
+
+    /* Start WiFi */
+    ESP_ERROR_CHECK(esp_wifi_start() );
+
+    /*
+     * Wait until either the connection is established (WIFI_CONNECTED_BIT) or
+     * connection failed for the maximum number of re-tries (WIFI_FAIL_BIT).
+     * The bits are set by event_handler() (see above)
+     */
+    EventBits_t bits = xEventGroupWaitBits(s_wifi_event_group,
+                                           WIFI_CONNECTED_BIT | WIFI_FAIL_BIT,
+                                           pdFALSE,
+                                           pdFALSE,
+                                           portMAX_DELAY);
+
+    /* xEventGroupWaitBits() returns the bits before the call returned,
+     * hence we can test which event actually happened. */
+    if (bits & WIFI_CONNECTED_BIT) {
+        ESP_LOGI(TAG_STA, "connected to ap SSID:%s password:%s",
+                 EXAMPLE_ESP_WIFI_STA_SSID, EXAMPLE_ESP_WIFI_STA_PASSWD);
+    } else if (bits & WIFI_FAIL_BIT) {
+        ESP_LOGI(TAG_STA, "Failed to connect to SSID:%s, password:%s",
+                 EXAMPLE_ESP_WIFI_STA_SSID, EXAMPLE_ESP_WIFI_STA_PASSWD);
+    } else {
+        ESP_LOGE(TAG_STA, "UNEXPECTED EVENT");
+        return;
+    }
+
+    /* Set sta as the default interface */
+    esp_netif_set_default_netif(esp_netif_sta);
+
+    /* Enable napt on the AP netif */
+    if (esp_netif_napt_enable(esp_netif_ap) != ESP_OK) {
+        ESP_LOGE(TAG_STA, "NAPT not enabled on the netif: %p", esp_netif_ap);
+    }
+}

examples/wifi/softap_sta/sdkconfig.defaults

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+# This file was generated using idf.py save-defconfig. It can be edited manually.
+# Espressif IoT Development Framework (ESP-IDF) Project Minimal Configuration
+#
+CONFIG_LWIP_IP_FORWARD=y
+CONFIG_LWIP_IPV4_NAPT=y