initial commit

managed_components/espressif__eppp_link/examples/host/CMakeLists.txt

@@ -0,0 +1,7 @@
+# The following four 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(pppos_host)

managed_components/espressif__eppp_link/examples/host/README.md

@@ -0,0 +1,9 @@
+
+# Client side demo of ESP-PPP-Link
+
+This is a basic demo of using esp-mqtt library, but connects to the internet using a PPPoS client. To run this example, you would need a PPP server that provides connectivity to the MQTT broker used in this example (by default a public broker accessible on the internet).
+
+If configured, this example could also run a ping session and an iperf console.
+
+
+The PPP server could be a Linux computer with `pppd` service or an ESP32 acting like a connection gateway with PPPoS server (see the "slave" project).

managed_components/espressif__eppp_link/examples/host/main/CMakeLists.txt

@@ -0,0 +1,6 @@
+if(CONFIG_EXAMPLE_WIFI_OVER_EPPP_CHANNEL)
+    set(wifi_over_channels channel_wifi_station.c)
+endif()
+idf_component_register(SRCS app_main.c register_iperf.c
+                            ${wifi_over_channels}
+                       INCLUDE_DIRS ".")

managed_components/espressif__eppp_link/examples/host/main/Kconfig.projbuild

@@ -0,0 +1,119 @@
+menu "Example Configuration"
+
+    config EXAMPLE_GLOBAL_DNS
+        hex "Set global DNS server"
+        range 0 0xFFFFFFFF
+        default 0x08080808
+        help
+            Global DNS server address.
+
+    config EXAMPLE_MQTT
+        bool "Run mqtt example"
+        default y
+        help
+            Run MQTT client after startup.
+
+    config EXAMPLE_BROKER_URL
+        string "Broker URL"
+        depends on EXAMPLE_MQTT
+        default "mqtt://mqtt.eclipseprojects.io"
+        help
+            URL of the broker to connect to.
+
+    config EXAMPLE_IPERF
+        bool "Run iperf"
+        default y
+        help
+            Init and run iperf console.
+
+    config EXAMPLE_SPI_HOST
+        int "SPI Host"
+        depends on EPPP_LINK_DEVICE_SPI
+        default 1
+        range 0 2
+        help
+            SPI host to use (SPI1_HOST=0, SPI2_HOST=1, SPI3_HOST=2).
+
+    config EXAMPLE_SPI_MOSI_PIN
+        int "MOSI Pin Number"
+        depends on EPPP_LINK_DEVICE_SPI
+        default 23
+        range 0 39
+        help
+            Pin number of SPI MOSI.
+
+    config EXAMPLE_SPI_MISO_PIN
+        int "MISO Pin Number"
+        depends on EPPP_LINK_DEVICE_SPI
+        default 19
+        range 0 39
+        help
+            Pin number of SPI MISO.
+
+    config EXAMPLE_SPI_SCLK_PIN
+        int "SCLK Pin Number"
+        depends on EPPP_LINK_DEVICE_SPI
+        default 18
+        range 0 39
+        help
+            Pin number of SPI SCLK.
+
+    config EXAMPLE_SPI_CS_PIN
+        int "CS Pin Number"
+        depends on EPPP_LINK_DEVICE_SPI
+        default 5
+        range 0 39
+        help
+            Pin number of SPI CS.
+
+    config EXAMPLE_SPI_INTR_PIN
+        int "Interrupt Pin Number"
+        depends on EPPP_LINK_DEVICE_SPI
+        default 17
+        range 0 39
+        help
+            Pin number of SPI interrupt.
+
+    config EXAMPLE_SPI_FREQUENCY
+        int "SPI Frequency (Hz)"
+        depends on EPPP_LINK_DEVICE_SPI
+        default 4000000
+        range 100000 80000000
+        help
+            SPI frequency in Hz.
+
+    config EXAMPLE_UART_TX_PIN
+        int "TXD Pin Number"
+        depends on EPPP_LINK_DEVICE_UART
+        default 17
+        range 0 31
+        help
+            Pin number of UART TX.
+
+    config EXAMPLE_UART_RX_PIN
+        int "RXD Pin Number"
+        depends on EPPP_LINK_DEVICE_UART
+        default 18
+        range 0 31
+        help
+            Pin number of UART RX.
+
+    config EXAMPLE_UART_BAUDRATE
+        int "Baudrate"
+        depends on EPPP_LINK_DEVICE_UART
+        default 921600
+        range 0 4000000
+        help
+            Baudrate used by the PPP over UART
+
+    config EXAMPLE_WIFI_OVER_EPPP_CHANNEL
+        bool "Use WiFi over EPPP channel"
+        default n
+        depends on EPPP_LINK_CHANNELS_SUPPORT && ESP_WIFI_REMOTE_ENABLED
+        help
+            Enable this option to use WiFi over EPPP channel.
+            If this option is enabled, the example will only start the Wi-Fi driver,
+            but the Wi-Fi netif will reside on client's end and will channel
+            the Rx and Tx data via EPPP channels.
+
+endmenu

managed_components/espressif__eppp_link/examples/host/main/app_main.c

@@ -0,0 +1,167 @@
+/*
+ * SPDX-FileCopyrightText: 2023-2025 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <string.h>
+#include "esp_system.h"
+#include "nvs_flash.h"
+#include "esp_event.h"
+#include "esp_netif.h"
+#include "eppp_link.h"
+#include "esp_log.h"
+#include "esp_check.h"
+#include "mqtt_client.h"
+#include "console_ping.h"
+
+void register_iperf(void);
+
+static const char *TAG = "eppp_host_example";
+
+#if CONFIG_EXAMPLE_MQTT
+static void mqtt_event_handler(void *args, esp_event_base_t base, int32_t event_id, void *event_data)
+{
+    ESP_LOGD(TAG, "Event dispatched from event loop base=%s, event_id=%" PRIi32 "", base, event_id);
+    esp_mqtt_event_handle_t event = event_data;
+    esp_mqtt_client_handle_t client = event->client;
+    int msg_id;
+    switch ((esp_mqtt_event_id_t)event_id) {
+    case MQTT_EVENT_CONNECTED:
+        ESP_LOGI(TAG, "MQTT_EVENT_CONNECTED");
+        msg_id = esp_mqtt_client_publish(client, "/topic/qos1", "data_3", 0, 1, 0);
+        ESP_LOGI(TAG, "sent publish successful, msg_id=%d", msg_id);
+
+        msg_id = esp_mqtt_client_subscribe(client, "/topic/qos0", 0);
+        ESP_LOGI(TAG, "sent subscribe successful, msg_id=%d", msg_id);
+
+        msg_id = esp_mqtt_client_subscribe(client, "/topic/qos1", 1);
+        ESP_LOGI(TAG, "sent subscribe successful, msg_id=%d", msg_id);
+
+        msg_id = esp_mqtt_client_unsubscribe(client, "/topic/qos1");
+        ESP_LOGI(TAG, "sent unsubscribe successful, msg_id=%d", msg_id);
+        break;
+    case MQTT_EVENT_DISCONNECTED:
+        ESP_LOGI(TAG, "MQTT_EVENT_DISCONNECTED");
+        break;
+
+    case MQTT_EVENT_SUBSCRIBED:
+        ESP_LOGI(TAG, "MQTT_EVENT_SUBSCRIBED, msg_id=%d", event->msg_id);
+        msg_id = esp_mqtt_client_publish(client, "/topic/qos0", "data", 0, 0, 0);
+        ESP_LOGI(TAG, "sent publish successful, msg_id=%d", msg_id);
+        break;
+    case MQTT_EVENT_UNSUBSCRIBED:
+        ESP_LOGI(TAG, "MQTT_EVENT_UNSUBSCRIBED, msg_id=%d", event->msg_id);
+        break;
+    case MQTT_EVENT_PUBLISHED:
+        ESP_LOGI(TAG, "MQTT_EVENT_PUBLISHED, msg_id=%d", event->msg_id);
+        break;
+    case MQTT_EVENT_DATA:
+        ESP_LOGI(TAG, "MQTT_EVENT_DATA");
+        printf("TOPIC=%.*s\r\n", event->topic_len, event->topic);
+        printf("DATA=%.*s\r\n", event->data_len, event->data);
+        break;
+    case MQTT_EVENT_ERROR:
+        ESP_LOGI(TAG, "MQTT_EVENT_ERROR");
+        if (event->error_handle->error_type == MQTT_ERROR_TYPE_TCP_TRANSPORT) {
+            ESP_LOGI(TAG, "Last errno string (%s)", strerror(event->error_handle->esp_transport_sock_errno));
+        }
+        break;
+    default:
+        ESP_LOGI(TAG, "Other event id:%d", event->event_id);
+        break;
+    }
+}
+
+static void mqtt_app_start(void)
+{
+    esp_mqtt_client_config_t mqtt_cfg = {
+        .broker.address.uri = "mqtt://mqtt.eclipseprojects.io",
+    };
+
+    esp_mqtt_client_handle_t client = esp_mqtt_client_init(&mqtt_cfg);
+    /* The last argument may be used to pass data to the event handler, in this example mqtt_event_handler */
+    esp_mqtt_client_register_event(client, ESP_EVENT_ANY_ID, mqtt_event_handler, NULL);
+    esp_mqtt_client_start(client);
+}
+#endif // MQTT
+
+void station_over_eppp_channel(void *arg);
+
+void app_main(void)
+{
+    ESP_LOGI(TAG, "[APP] Startup..");
+    ESP_LOGI(TAG, "[APP] Free memory: %" PRIu32 " bytes", esp_get_free_heap_size());
+    ESP_LOGI(TAG, "[APP] IDF version: %s", esp_get_idf_version());
+
+    ESP_ERROR_CHECK(nvs_flash_init());
+    ESP_ERROR_CHECK(esp_netif_init());
+    ESP_ERROR_CHECK(esp_event_loop_create_default());
+
+    /* Sets up the default EPPP-connection
+     */
+    eppp_config_t config = EPPP_DEFAULT_CLIENT_CONFIG();
+#if CONFIG_EPPP_LINK_DEVICE_SPI
+    config.transport = EPPP_TRANSPORT_SPI;
+    config.spi.is_master = true;
+    config.spi.host = CONFIG_EXAMPLE_SPI_HOST;
+    config.spi.mosi = CONFIG_EXAMPLE_SPI_MOSI_PIN;
+    config.spi.miso = CONFIG_EXAMPLE_SPI_MISO_PIN;
+    config.spi.sclk = CONFIG_EXAMPLE_SPI_SCLK_PIN;
+    config.spi.cs = CONFIG_EXAMPLE_SPI_CS_PIN;
+    config.spi.intr = CONFIG_EXAMPLE_SPI_INTR_PIN;
+    config.spi.freq = CONFIG_EXAMPLE_SPI_FREQUENCY;
+#elif CONFIG_EPPP_LINK_DEVICE_UART
+    config.transport = EPPP_TRANSPORT_UART;
+    config.uart.tx_io = CONFIG_EXAMPLE_UART_TX_PIN;
+    config.uart.rx_io = CONFIG_EXAMPLE_UART_RX_PIN;
+    config.uart.baud = CONFIG_EXAMPLE_UART_BAUDRATE;
+#elif CONFIG_EPPP_LINK_DEVICE_ETH
+    config.transport = EPPP_TRANSPORT_ETHERNET;
+#else
+    config.transport = EPPP_TRANSPORT_SDIO;
+    config.sdio.is_host = true;
+#endif
+    esp_netif_t *eppp_netif = eppp_connect(&config);
+    if (eppp_netif == NULL) {
+        ESP_LOGE(TAG, "Failed to connect");
+        return ;
+    }
+    // Setup global DNS
+    esp_netif_dns_info_t dns;
+    dns.ip.u_addr.ip4.addr = esp_netif_htonl(CONFIG_EXAMPLE_GLOBAL_DNS);
+    dns.ip.type = ESP_IPADDR_TYPE_V4;
+    ESP_ERROR_CHECK(esp_netif_set_dns_info(eppp_netif, ESP_NETIF_DNS_MAIN, &dns));
+
+    // Initialize console REPL
+    ESP_ERROR_CHECK(console_cmd_init());
+
+#if CONFIG_EXAMPLE_IPERF
+    register_iperf();
+
+    printf("\n =======================================================\n");
+    printf(" |       Steps to Test EPPP-host bandwidth             |\n");
+    printf(" |                                                     |\n");
+    printf(" |  1. Wait for the ESP32 to get an IP                 |\n");
+    printf(" |  2. Server: 'iperf -u -s -i 3' (on host)            |\n");
+    printf(" |  3. Client: 'iperf -u -c SERVER_IP -t 60 -i 3'      |\n");
+    printf(" |                                                     |\n");
+    printf(" =======================================================\n\n");
+
+#endif // CONFIG_EXAMPLE_IPERF
+
+    // Register the ping command
+    ESP_ERROR_CHECK(console_cmd_ping_register());
+    // start console REPL
+    ESP_ERROR_CHECK(console_cmd_start());
+
+#ifdef CONFIG_EXAMPLE_WIFI_OVER_EPPP_CHANNEL
+    station_over_eppp_channel(eppp_netif);
+#endif
+#if CONFIG_EXAMPLE_MQTT
+    mqtt_app_start();
+#endif
+}

managed_components/espressif__eppp_link/examples/host/main/channel_wifi_station.c

@@ -0,0 +1,185 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <string.h>
+#include "esp_system.h"
+#include "esp_event.h"
+#include "esp_netif.h"
+#include "eppp_link.h"
+#include "esp_log.h"
+#include "esp_check.h"
+#include "esp_wifi_remote.h"
+
+#define CHAT_CHANNEL 1
+#define WIFI_CHANNEL 2
+
+typedef enum {
+    UNKNOWN,
+    HELLO,
+    START,
+    ERROR,
+} state_t;
+
+typedef struct context {
+    eppp_channel_fn_t transmit;
+    EventGroupHandle_t flags;
+    state_t state;
+    esp_netif_t *eppp;
+} context_t;
+
+#define HELLO_BIT BIT0
+#define START_BIT BIT1
+#define CONNECT_BIT BIT2
+#define SERVER_UP_BIT BIT3
+
+#define ALL_BITS (HELLO_BIT | START_BIT | CONNECT_BIT | SERVER_UP_BIT)
+
+static uint8_t s_wifi_mac_addr[6] = { 0 };
+static const char *TAG = "eppp_host_example_with_channels";
+
+esp_netif_t* esp_wifi_remote_create_default_sta(void);
+
+static void event_handler(void *arg, esp_event_base_t event_base, int32_t event_id, void *event_data)
+{
+    ESP_LOGI(TAG, "IP event_handler: event_base=%s event_id=%d", event_base, event_id);
+    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, "Got IP:" IPSTR, IP2STR(&event->ip_info.ip));
+    }
+}
+
+esp_err_t esp_wifi_remote_get_mac(wifi_interface_t ifx, uint8_t mac[6])
+{
+    if (ifx != WIFI_IF_STA) {
+        return ESP_ERR_INVALID_STATE;
+
+    }
+    for (int i = 0; i < sizeof(s_wifi_mac_addr); i++) {
+        if (s_wifi_mac_addr[i] == 0) {
+            return ESP_ERR_INVALID_STATE;
+        }
+    }
+    memcpy(mac, s_wifi_mac_addr, sizeof(s_wifi_mac_addr));
+    return ESP_OK;
+}
+
+static esp_err_t eppp_receive(esp_netif_t *netif, int nr, void *buffer, size_t len)
+{
+    context_t *ctx = eppp_get_context(netif);
+    if (nr == CHAT_CHANNEL) {
+        ESP_LOGI(TAG, "Received channel=%d len=%d %.*s", nr, (int)len, (int)len, (char *)buffer);
+        const char hello[] = "Hello client";
+        const char mac[] = "MAC: ";
+        const char connected[] = "Connected";
+        const char server_up[] = "Server up";
+        size_t mac_len = 5 /* MAC: */ + 6 * 2 /* 6 bytes per char */ + 5 /* : */ + 1 /* \0 */;
+        if (len == sizeof(server_up) && memcmp(buffer, server_up, len) == 0) {
+            if (ctx->state == UNKNOWN) {
+                ESP_LOGI(TAG, "Server is up");
+                ctx->state = HELLO;
+            } else {
+                ESP_LOGE(TAG, "Received server up in unexpected state %d", ctx->state);
+                ctx->state = ERROR;
+            }
+            xEventGroupSetBits(ctx->flags, SERVER_UP_BIT);
+        } else if (len == sizeof(hello) && memcmp(buffer, hello, len) == 0) {
+            if (ctx->state == HELLO) {
+                xEventGroupSetBits(ctx->flags, HELLO_BIT);
+            } else {
+                ESP_LOGE(TAG, "Received hello in unexpected state %d", ctx->state);
+                ctx->state = ERROR;
+            }
+        } else if (len == mac_len && memcmp(buffer, mac, 5) == 0) {
+            if (ctx->state == HELLO) {
+                uint8_t mac_addr[6];
+                sscanf((char *)buffer + 5, "%2" PRIx8 ":%2" PRIx8 ":%2" PRIx8 ":%2" PRIx8 ":%2" PRIx8 ":%2" PRIx8,
+                       &mac_addr[0], &mac_addr[1], &mac_addr[2], &mac_addr[3], &mac_addr[4], &mac_addr[5]);
+                ESP_LOGI(TAG, "Parsed MAC: %02x:%02x:%02x:%02x:%02x:%02x\n", mac_addr[0], mac_addr[1], mac_addr[2], mac_addr[3], mac_addr[4], mac_addr[5]);
+                memcpy(s_wifi_mac_addr, mac_addr, sizeof(s_wifi_mac_addr));
+                xEventGroupSetBits(ctx->flags, START_BIT);
+            } else {
+                ESP_LOGE(TAG, "Received MAC in unexpected state %d", ctx->state);
+                ctx->state = ERROR;
+            }
+        } else if (len == sizeof(connected) && memcmp(buffer, connected, len) == 0) {
+            if (ctx->state == START) {
+                xEventGroupSetBits(ctx->flags, CONNECT_BIT);
+            } else {
+                ESP_LOGE(TAG, "Received connected in unexpected state %d", ctx->state);
+                ctx->state = ERROR;
+            }
+        }
+    } else if (nr == WIFI_CHANNEL) {
+        ESP_LOGD(TAG, "Received WIFI channel=%d len=%d", nr, (int)len);
+        ESP_LOG_BUFFER_HEXDUMP("wifi-receive", buffer, len, ESP_LOG_VERBOSE);
+        return esp_wifi_remote_channel_rx(ctx->eppp, buffer, NULL, len);
+    } else {
+        ESP_LOGE(TAG, "Incorrect channel number %d", nr);
+        return ESP_FAIL;
+    }
+    return ESP_OK;
+}
+
+static esp_err_t wifi_transmit(void *h, void *buffer, size_t len)
+{
+    esp_netif_t *eppp = (esp_netif_t *)h;
+    context_t *ctx = eppp_get_context(eppp);
+    ESP_LOG_BUFFER_HEXDUMP("wifi-transmit", buffer, len, ESP_LOG_VERBOSE);
+    return ctx->transmit(eppp, WIFI_CHANNEL, buffer, len);
+}
+
+void esp_netif_destroy_wifi_remote(void *esp_netif);
+
+void station_over_eppp_channel(void *arg)
+{
+    __attribute__((unused)) esp_err_t ret;
+    esp_netif_t *wifi = NULL;
+    context_t ctx = {
+        .transmit = NULL,
+        .flags = NULL,
+        .state = UNKNOWN,
+        .eppp = (esp_netif_t *)arg
+    };
+    ESP_GOTO_ON_FALSE(ctx.eppp != NULL, ESP_FAIL, err, TAG, "Incorrect EPPP netif");
+    ESP_GOTO_ON_FALSE(ctx.flags = xEventGroupCreate(), ESP_FAIL, err, TAG, "Failed to create event group");
+    ESP_GOTO_ON_ERROR(eppp_add_channels(ctx.eppp, &ctx.transmit, eppp_receive, &ctx), err, TAG, "Failed to add channels");
+    ESP_GOTO_ON_FALSE(ctx.transmit, ESP_FAIL, err, TAG, "Channel tx function is not set");
+    ESP_GOTO_ON_ERROR(esp_wifi_remote_channel_set(WIFI_IF_STA, ctx.eppp, wifi_transmit), err, TAG, "Failed to set wifi channel tx function");
+    esp_event_handler_register(IP_EVENT, IP_EVENT_STA_GOT_IP, event_handler, &ctx);
+
+    while (1) {
+        EventBits_t bits = xEventGroupWaitBits(ctx.flags, ALL_BITS, pdTRUE, pdFALSE, pdMS_TO_TICKS(1000));
+        if (bits & HELLO_BIT) {
+            ESP_LOGI(TAG, "Hello done");
+            if (wifi == NULL) {
+                wifi = esp_wifi_remote_create_default_sta();
+            }
+            const char command[] = "Get MAC";
+            ctx.transmit(ctx.eppp, CHAT_CHANNEL, (void*)command, sizeof(command));
+        } else if (bits & START_BIT) {
+            ctx.state = START;
+            ESP_LOGI(TAG, "Starting WIFI");
+            esp_event_post(WIFI_REMOTE_EVENT, WIFI_EVENT_STA_START, NULL, 0, 0);
+        } else if (bits & CONNECT_BIT) {
+            ESP_LOGI(TAG, "WIFI connected");
+            esp_event_post(WIFI_REMOTE_EVENT, WIFI_EVENT_STA_CONNECTED, NULL, 0, 0);
+        } else if ((bits & SERVER_UP_BIT) == SERVER_UP_BIT || ctx.state != START)  {
+            if (ctx.state == ERROR) {
+                esp_netif_destroy_wifi_remote(wifi);
+                wifi = NULL;
+                ESP_LOGI(TAG, "WiFi netif has been destroyed");
+            }
+            const char hello[] = "Hello server";
+            ctx.transmit(ctx.eppp, CHAT_CHANNEL, (void*)hello, sizeof(hello));
+            ctx.state = HELLO;
+        }
+    }
+
+err:
+    vTaskDelete(NULL);
+}

managed_components/espressif__eppp_link/examples/host/main/idf_component.yml

@@ -0,0 +1,6 @@
+dependencies:
+  console_cmd_ping:
+    version: '*'
+  espressif/eppp_link:
+    version: '*'
+  espressif/iperf-cmd: ^0.1.1

managed_components/espressif__eppp_link/examples/host/main/register_iperf.c

@@ -0,0 +1,179 @@
+/*
+ * SPDX-FileCopyrightText: 2023-2024 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+
+#include <stdio.h>
+#include <string.h>
+#include <inttypes.h>
+#include "freertos/FreeRTOS.h"
+#include "freertos/event_groups.h"
+#include "sys/socket.h" // for INADDR_ANY
+#include "esp_netif.h"
+#include "esp_log.h"
+#include "esp_system.h"
+#include "esp_event.h"
+#include "esp_log.h"
+#include "esp_netif.h"
+#include "esp_netif_ppp.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/event_groups.h"
+
+#include "esp_console.h"
+#include "esp_event.h"
+#include "esp_bit_defs.h"
+#include "argtable3/argtable3.h"
+#include "iperf.h"
+#include "sdkconfig.h"
+
+/* "iperf" command */
+
+static struct {
+    struct arg_str *ip;
+    struct arg_lit *server;
+    struct arg_lit *udp;
+    struct arg_lit *version;
+    struct arg_int *port;
+    struct arg_int *length;
+    struct arg_int *interval;
+    struct arg_int *time;
+    struct arg_int *bw_limit;
+    struct arg_lit *abort;
+    struct arg_end *end;
+} iperf_args;
+
+static int ppp_cmd_iperf(int argc, char **argv)
+{
+    int nerrors = arg_parse(argc, argv, (void **)&iperf_args);
+    // ethernet iperf only support IPV4 address
+    iperf_cfg_t cfg = {.type = IPERF_IP_TYPE_IPV4};
+
+    if (nerrors != 0) {
+        arg_print_errors(stderr, iperf_args.end, argv[0]);
+        return 0;
+    }
+
+    /* iperf -a */
+    if (iperf_args.abort->count != 0) {
+        iperf_stop();
+        return 0;
+    }
+
+    if (((iperf_args.ip->count == 0) && (iperf_args.server->count == 0)) ||
+            ((iperf_args.ip->count != 0) && (iperf_args.server->count != 0))) {
+        ESP_LOGE(__func__, "Wrong mode! ESP32 should run in client or server mode");
+        return 0;
+    }
+
+    /* iperf -s */
+    if (iperf_args.ip->count == 0) {
+        cfg.flag |= IPERF_FLAG_SERVER;
+    }
+    /* iperf -c SERVER_ADDRESS */
+    else {
+        cfg.destination_ip4 = esp_ip4addr_aton(iperf_args.ip->sval[0]);
+        cfg.flag |= IPERF_FLAG_CLIENT;
+    }
+
+    if (iperf_args.length->count == 0) {
+        cfg.len_send_buf = 0;
+    } else {
+        cfg.len_send_buf = iperf_args.length->ival[0];
+    }
+
+    cfg.source_ip4 = INADDR_ANY;
+
+    /* iperf -u */
+    if (iperf_args.udp->count == 0) {
+        cfg.flag |= IPERF_FLAG_TCP;
+    } else {
+        cfg.flag |= IPERF_FLAG_UDP;
+    }
+
+    /* iperf -p */
+    if (iperf_args.port->count == 0) {
+        cfg.sport = IPERF_DEFAULT_PORT;
+        cfg.dport = IPERF_DEFAULT_PORT;
+    } else {
+        if (cfg.flag & IPERF_FLAG_SERVER) {
+            cfg.sport = iperf_args.port->ival[0];
+            cfg.dport = IPERF_DEFAULT_PORT;
+        } else {
+            cfg.sport = IPERF_DEFAULT_PORT;
+            cfg.dport = iperf_args.port->ival[0];
+        }
+    }
+
+    /* iperf -i */
+    if (iperf_args.interval->count == 0) {
+        cfg.interval = IPERF_DEFAULT_INTERVAL;
+    } else {
+        cfg.interval = iperf_args.interval->ival[0];
+        if (cfg.interval <= 0) {
+            cfg.interval = IPERF_DEFAULT_INTERVAL;
+        }
+    }
+
+    /* iperf -t */
+    if (iperf_args.time->count == 0) {
+        cfg.time = IPERF_DEFAULT_TIME;
+    } else {
+        cfg.time = iperf_args.time->ival[0];
+        if (cfg.time <= cfg.interval) {
+            cfg.time = cfg.interval;
+        }
+    }
+
+    /* iperf -b */
+    if (iperf_args.bw_limit->count == 0) {
+        cfg.bw_lim = IPERF_DEFAULT_NO_BW_LIMIT;
+    } else {
+        cfg.bw_lim = iperf_args.bw_limit->ival[0];
+        if (cfg.bw_lim <= 0) {
+            cfg.bw_lim = IPERF_DEFAULT_NO_BW_LIMIT;
+        }
+    }
+
+    printf("mode=%s-%s sip=" IPSTR ":%" PRIu16 ", dip=%" PRIu32 ".%" PRIu32 ".%" PRIu32 ".%" PRIu32 ":%" PRIu16 ", interval=%" PRIu32 ", time=%" PRIu32 "\r\n",
+           cfg.flag & IPERF_FLAG_TCP ? "tcp" : "udp",
+           cfg.flag & IPERF_FLAG_SERVER ? "server" : "client",
+           (uint16_t) cfg.source_ip4 & 0xFF,
+           (uint16_t) (cfg.source_ip4 >> 8) & 0xFF,
+           (uint16_t) (cfg.source_ip4 >> 16) & 0xFF,
+           (uint16_t) (cfg.source_ip4 >> 24) & 0xFF,
+           cfg.sport,
+           cfg.destination_ip4 & 0xFF, (cfg.destination_ip4 >> 8) & 0xFF,
+           (cfg.destination_ip4 >> 16) & 0xFF, (cfg.destination_ip4 >> 24) & 0xFF, cfg.dport,
+           cfg.interval, cfg.time);
+
+    iperf_start(&cfg);
+    return 0;
+}
+
+void register_iperf(void)
+{
+
+    iperf_args.ip = arg_str0("c", "client", "<ip>",
+                             "run in client mode, connecting to <host>");
+    iperf_args.server = arg_lit0("s", "server", "run in server mode");
+    iperf_args.udp = arg_lit0("u", "udp", "use UDP rather than TCP");
+    iperf_args.version = arg_lit0("V", "ipv6_domain", "use IPV6 address rather than IPV4");
+    iperf_args.port = arg_int0("p", "port", "<port>",
+                               "server port to listen on/connect to");
+    iperf_args.length = arg_int0("l", "len", "<length>", "set read/write buffer size");
+    iperf_args.interval = arg_int0("i", "interval", "<interval>",
+                                   "seconds between periodic bandwidth reports");
+    iperf_args.time = arg_int0("t", "time", "<time>", "time in seconds to transmit for (default 10 secs)");
+    iperf_args.bw_limit = arg_int0("b", "bandwidth", "<bandwidth>", "bandwidth to send at in Mbits/sec");
+    iperf_args.abort = arg_lit0("a", "abort", "abort running iperf");
+    iperf_args.end = arg_end(1);
+    const esp_console_cmd_t iperf_cmd = {
+        .command = "iperf",
+        .help = "iperf command",
+        .hint = NULL,
+        .func = &ppp_cmd_iperf,
+        .argtable = &iperf_args
+    };
+    ESP_ERROR_CHECK(esp_console_cmd_register(&iperf_cmd));
+}

managed_components/espressif__eppp_link/examples/host/sdkconfig.ci.1

@@ -0,0 +1,4 @@
+CONFIG_IDF_TARGET="esp32s3"
+CONFIG_EPPP_LINK_DEVICE_SPI=y
+CONFIG_EPPP_LINK_CHANNELS_SUPPORT=y
+CONFIG_EPPP_LINK_USES_PPP=y

managed_components/espressif__eppp_link/examples/host/sdkconfig.ci.2

@@ -0,0 +1,3 @@
+CONFIG_IDF_TARGET="esp32c3"
+CONFIG_EPPP_LINK_DEVICE_UART=y
+CONFIG_EPPP_LINK_CHANNELS_SUPPORT=y

managed_components/espressif__eppp_link/examples/host/sdkconfig.ci.eth

@@ -0,0 +1,2 @@
+CONFIG_IDF_TARGET="esp32"
+CONFIG_EPPP_LINK_DEVICE_ETH=y

managed_components/espressif__eppp_link/examples/host/sdkconfig.ci.sdio

@@ -0,0 +1,2 @@
+CONFIG_IDF_TARGET="esp32p4"
+CONFIG_EPPP_LINK_DEVICE_SDIO=y

managed_components/espressif__eppp_link/examples/host/sdkconfig.ci.spi

@@ -0,0 +1 @@
+CONFIG_EPPP_LINK_DEVICE_SPI=y

managed_components/espressif__eppp_link/examples/host/sdkconfig.ci.uart

@@ -0,0 +1 @@
+CONFIG_EPPP_LINK_DEVICE_UART=y

managed_components/espressif__eppp_link/examples/host/sdkconfig.defaults

@@ -0,0 +1 @@
+CONFIG_LWIP_PPP_VJ_HEADER_COMPRESSION=n

managed_components/espressif__eppp_link/examples/slave/CMakeLists.txt

@@ -0,0 +1,6 @@
+# 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(pppos_slave)

managed_components/espressif__eppp_link/examples/slave/README.md

@@ -0,0 +1,7 @@
+
+# Wi-Fi station to PPPoS server
+
+This example demonstrate using NAPT to bring connectivity from WiFi station to PPPoS server.
+
+This example expect a PPPoS client to connect to the server and use the connectivity.
+The client could be a Linux computer with `pppd` service or another microcontroller with PPP client (or another ESP32 with not WiFi interface)

managed_components/espressif__eppp_link/examples/slave/main/CMakeLists.txt

@@ -0,0 +1,6 @@
+if(CONFIG_EXAMPLE_WIFI_OVER_EPPP_CHANNEL)
+    set(wifi_over_channels channel_wifi_station.c)
+endif()
+idf_component_register(SRCS eppp_slave.c
+                            ${wifi_over_channels}
+                       INCLUDE_DIRS ".")

managed_components/espressif__eppp_link/examples/slave/main/Kconfig.projbuild

@@ -0,0 +1,111 @@
+menu "Example Configuration"
+
+    config ESP_WIFI_SSID
+        string "WiFi SSID"
+        default "myssid"
+        help
+            SSID (network name) for the example to connect to.
+
+    config ESP_WIFI_PASSWORD
+        string "WiFi Password"
+        default "mypassword"
+        help
+            WiFi password (WPA or WPA2) for the example to use.
+
+    config ESP_MAXIMUM_RETRY
+        int "Maximum retry"
+        default 5
+        help
+            Set the Maximum retry to avoid station reconnecting to the AP unlimited when the AP is really inexistent.
+
+    config EXAMPLE_SPI_HOST
+        int "SPI Host"
+        depends on EPPP_LINK_DEVICE_SPI
+        default 1
+        range 0 2
+        help
+            SPI host to use (SPI1_HOST=0, SPI2_HOST=1, SPI3_HOST=2).
+
+    config EXAMPLE_SPI_MOSI_PIN
+        int "MOSI Pin Number"
+        depends on EPPP_LINK_DEVICE_SPI
+        default 23
+        range 0 39
+        help
+            Pin number of SPI MOSI.
+
+    config EXAMPLE_SPI_MISO_PIN
+        int "MISO Pin Number"
+        depends on EPPP_LINK_DEVICE_SPI
+        default 19
+        range 0 39
+        help
+            Pin number of SPI MISO.
+
+    config EXAMPLE_SPI_SCLK_PIN
+        int "SCLK Pin Number"
+        depends on EPPP_LINK_DEVICE_SPI
+        default 18
+        range 0 39
+        help
+            Pin number of SPI SCLK.
+
+    config EXAMPLE_SPI_CS_PIN
+        int "CS Pin Number"
+        depends on EPPP_LINK_DEVICE_SPI
+        default 5
+        range 0 39
+        help
+            Pin number of SPI CS.
+
+    config EXAMPLE_SPI_INTR_PIN
+        int "Interrupt Pin Number"
+        depends on EPPP_LINK_DEVICE_SPI
+        default 17
+        range 0 39
+        help
+            Pin number of SPI interrupt.
+
+    config EXAMPLE_SPI_FREQUENCY
+        int "SPI Frequency (Hz)"
+        depends on EPPP_LINK_DEVICE_SPI
+        default 1000000
+        range 100000 80000000
+        help
+            SPI frequency in Hz.
+
+    config EXAMPLE_UART_TX_PIN
+        int "TXD Pin Number"
+        depends on EPPP_LINK_DEVICE_UART
+        default 18
+        range 0 31
+        help
+            Pin number of UART TX.
+
+    config EXAMPLE_UART_RX_PIN
+        int "RXD Pin Number"
+        depends on EPPP_LINK_DEVICE_UART
+        default 17
+        range 0 31
+        help
+            Pin number of UART RX.
+
+    config EXAMPLE_UART_BAUDRATE
+        int "Baudrate"
+        depends on EPPP_LINK_DEVICE_UART
+        default 921600
+        range 0 4000000
+        help
+            Baudrate used by the PPP over UART
+
+    config EXAMPLE_WIFI_OVER_EPPP_CHANNEL
+        bool "Use WiFi over EPPP channel"
+        default n
+        depends on EPPP_LINK_CHANNELS_SUPPORT
+        help
+            Enable this option to use WiFi over EPPP channel.
+            If this option is enabled, the example will only start the Wi-Fi driver,
+            but the Wi-Fi netif will reside on client's end and will channel
+            the Rx and Tx data via EPPP channels.
+
+endmenu

managed_components/espressif__eppp_link/examples/slave/main/channel_wifi_station.c

@@ -0,0 +1,169 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <string.h>
+#include "esp_system.h"
+#include "esp_event.h"
+#include "esp_netif.h"
+#include "eppp_link.h"
+#include "esp_log.h"
+#include "esp_check.h"
+#include "esp_private/wifi.h"
+
+#define CHAT_CHANNEL 1
+#define WIFI_CHANNEL 2
+
+typedef enum {
+    UNKNOWN,
+    HELLO,
+    START,
+    ERROR,
+} state_t;
+
+typedef struct context {
+    eppp_channel_fn_t transmit;
+    EventGroupHandle_t flags;
+    state_t state;
+    esp_netif_t *eppp;
+} context_t;
+
+#define HELLO_BIT BIT0
+#define START_BIT BIT1
+#define CONNECT_BIT BIT2
+#define DISCONNECT_BIT BIT3
+
+#define ALL_BITS (HELLO_BIT | START_BIT | CONNECT_BIT | DISCONNECT_BIT)
+
+static const char *TAG = "eppp_host_example_with_channels";
+static context_t *s_eppp_channel_ctx = NULL;
+
+static esp_err_t eppp_receive(esp_netif_t *netif, int nr, void *buffer, size_t len)
+{
+    context_t *ctx = eppp_get_context(netif);
+    if (nr == CHAT_CHANNEL) {
+        ESP_LOGI(TAG, "Received channel=%d len=%d %.*s", nr, (int)len, (int)len, (char *)buffer);
+        const char hello[] = "Hello server";
+        const char mac[] = "Get MAC";
+        if (len == sizeof(hello) && memcmp(buffer, hello, len) == 0) {
+            if (ctx->state == HELLO) {
+                xEventGroupSetBits(ctx->flags, HELLO_BIT);
+            } else {
+                ctx->state = ERROR;
+            }
+        } else if (len == sizeof(mac) && memcmp(buffer, mac, 5) == 0) {
+            if (ctx->state == HELLO) {
+                xEventGroupSetBits(ctx->flags, START_BIT);
+            } else {
+                ctx->state = ERROR;
+            }
+        }
+    } else if (nr == WIFI_CHANNEL) {
+        ESP_LOGD(TAG, "Received WIFI channel=%d len=%d", nr, (int)len);
+        ESP_LOG_BUFFER_HEXDUMP("wifi-receive", buffer, len, ESP_LOG_VERBOSE);
+        return esp_wifi_internal_tx(WIFI_IF_STA, buffer, len);
+    } else {
+        ESP_LOGE(TAG, "Incorrect channel number %d", nr);
+        return ESP_FAIL;
+    }
+    return ESP_OK;
+}
+
+static esp_err_t wifi_receive(void *buffer, uint16_t len, void *eb)
+{
+    s_eppp_channel_ctx->transmit(s_eppp_channel_ctx->eppp, WIFI_CHANNEL, buffer, len);
+    esp_wifi_internal_free_rx_buffer(eb);
+    return ESP_OK;
+}
+
+static void event_handler(void *arg, esp_event_base_t event_base, int32_t event_id, void *event_data)
+{
+    context_t *ctx = arg;
+    ESP_LOGI(TAG, "event_handler: event_base=%s event_id=%d", event_base, event_id);
+    if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_START) {
+        ESP_LOGI(TAG, "WIFI start event");
+        esp_wifi_connect();
+        xEventGroupSetBits(ctx->flags, CONNECT_BIT);
+    } else if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_DISCONNECTED) {
+        ESP_LOGI(TAG, "connect to the AP fail");
+        xEventGroupSetBits(ctx->flags, DISCONNECT_BIT);
+    }
+}
+
+
+static void init_wifi_driver(context_t *ctx)
+{
+    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
+    ESP_ERROR_CHECK(esp_wifi_init(&cfg));
+    ESP_ERROR_CHECK(esp_event_handler_register(WIFI_EVENT, ESP_EVENT_ANY_ID,
+                                               event_handler, ctx));
+    wifi_config_t wifi_config = {
+        .sta = {
+            .ssid = CONFIG_ESP_WIFI_SSID,
+            .password = CONFIG_ESP_WIFI_PASSWORD,
+        },
+    };
+    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
+    ESP_ERROR_CHECK(esp_wifi_set_config(WIFI_IF_STA, &wifi_config));
+}
+
+void station_over_eppp_channel(void *arg)
+{
+    __attribute__((unused)) esp_err_t ret;
+    context_t ctx = {
+        .transmit = NULL,
+        .flags = NULL,
+        .state = UNKNOWN,
+        .eppp = (esp_netif_t *)arg
+    };
+    ESP_GOTO_ON_FALSE(ctx.flags = xEventGroupCreate(), ESP_FAIL, err, TAG, "Failed to create event group");
+    ESP_GOTO_ON_ERROR(eppp_add_channels(ctx.eppp, &ctx.transmit, eppp_receive, &ctx), err, TAG, "Failed to add channels");
+    ESP_GOTO_ON_FALSE(ctx.transmit, ESP_FAIL, err, TAG, "Channel tx function is not set");
+    init_wifi_driver(&ctx);
+
+    while (1) {
+        EventBits_t bits = xEventGroupWaitBits(ctx.flags, ALL_BITS, pdTRUE, pdFALSE, pdMS_TO_TICKS(1000));
+        if (bits & HELLO_BIT) {
+            ESP_LOGI(TAG, "Hello from client received");
+            const char hello[] = "Hello client";
+            ctx.transmit(ctx.eppp, CHAT_CHANNEL, (void*)hello, sizeof(hello));
+        } else if (bits & START_BIT) {
+            ctx.state = START;
+            ESP_LOGI(TAG, "Starting WIFI");
+            uint8_t mac[6];
+            if (esp_wifi_get_mac(WIFI_IF_STA, mac) != ESP_OK) {
+                ESP_LOGE(TAG, "esp_wifi_get_mac failed");
+                ctx.state = ERROR;
+                continue;
+            }
+            char mac_data[5 /* MAC: */ + 6 * 2 /* 6 bytes per char */ + 5 /* : */ + 1 /* \0 */];
+            sprintf(mac_data, "MAC: %02x:%02x:%02x:%02x:%02x:%02x", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
+            ESP_LOGI(TAG, "Sending MAC: %.*s", (int)sizeof(mac_data), mac_data);
+            ctx.transmit(ctx.eppp, CHAT_CHANNEL, (void*)mac_data, sizeof(mac_data));
+            ret = esp_wifi_start();
+            ESP_LOGI(TAG, "WIFI start result: %d", ret);
+            s_eppp_channel_ctx = &ctx;
+            esp_wifi_internal_reg_rxcb(WIFI_IF_STA, wifi_receive);
+        } else if (bits & CONNECT_BIT) {
+            ESP_LOGI(TAG, "WIFI connected");
+            const char connected[] = "Connected";
+            ctx.transmit(ctx.eppp, CHAT_CHANNEL, (void*)connected, sizeof(connected));
+        } else if (bits & DISCONNECT_BIT) {
+            const char disconnected[] = "Disconnected";
+            ctx.transmit(ctx.eppp, CHAT_CHANNEL, (void*)disconnected, sizeof(disconnected));
+        } else if (ctx.state != START) {
+            ctx.state = HELLO;
+            const char up[] = "Server up";
+            esp_wifi_disconnect();
+            esp_wifi_stop();
+            ctx.transmit(ctx.eppp, CHAT_CHANNEL, (void*)up, sizeof(up));
+        }
+    }
+
+err:
+    vTaskDelete(NULL);
+}

managed_components/espressif__eppp_link/examples/slave/main/eppp_slave.c

@@ -0,0 +1,167 @@
+/*
+ * SPDX-FileCopyrightText: 2023-2025 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+
+#include <string.h>
+#include "freertos/FreeRTOS.h"
+#include "freertos/event_groups.h"
+#include "esp_system.h"
+#include "esp_wifi.h"
+#include "esp_event.h"
+#include "esp_log.h"
+#include "esp_check.h"
+#include "nvs_flash.h"
+#include "eppp_link.h"
+#include "inttypes.h"
+
+static const char *TAG = "eppp_slave";
+
+#if defined(CONFIG_SOC_WIFI_SUPPORTED) && !defined(CONFIG_EXAMPLE_WIFI_OVER_EPPP_CHANNEL)
+
+/* FreeRTOS event group to signal when we are connected*/
+static EventGroupHandle_t s_wifi_event_group;
+
+/* 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 int s_retry_num = 0;
+
+static void event_handler(void *arg, esp_event_base_t event_base, int32_t event_id, void *event_data)
+{
+    ESP_LOGI(TAG, "event_handler: event_base=%s event_id=%" PRIi32, event_base, event_id);
+    if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_START) {
+        ESP_LOGI(TAG, "WIFI start event");
+        esp_wifi_connect();
+    } else if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_DISCONNECTED) {
+        if (s_retry_num < CONFIG_ESP_MAXIMUM_RETRY) {
+            esp_wifi_connect();
+            s_retry_num++;
+            ESP_LOGI(TAG, "retry to connect to the AP");
+        } else {
+            xEventGroupSetBits(s_wifi_event_group, WIFI_FAIL_BIT);
+        }
+        ESP_LOGI(TAG, "connect to the AP fail");
+    } 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, "got ip:" IPSTR, IP2STR(&event->ip_info.ip));
+        s_retry_num = 0;
+        xEventGroupSetBits(s_wifi_event_group, WIFI_CONNECTED_BIT);
+    }
+}
+
+void init_network_interface(void)
+{
+    s_wifi_event_group = xEventGroupCreate();
+
+    esp_netif_create_default_wifi_sta();
+
+    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
+    ESP_ERROR_CHECK(esp_wifi_init(&cfg));
+
+    esp_event_handler_instance_t instance_any_id;
+    esp_event_handler_instance_t instance_got_ip;
+    ESP_ERROR_CHECK(esp_event_handler_instance_register(WIFI_EVENT,
+                                                        ESP_EVENT_ANY_ID,
+                                                        &event_handler,
+                                                        NULL,
+                                                        &instance_any_id));
+    ESP_ERROR_CHECK(esp_event_handler_instance_register(IP_EVENT,
+                                                        IP_EVENT_STA_GOT_IP,
+                                                        &event_handler,
+                                                        NULL,
+                                                        &instance_got_ip));
+
+    wifi_config_t wifi_config = {
+        .sta = {
+            .ssid = CONFIG_ESP_WIFI_SSID,
+            .password = CONFIG_ESP_WIFI_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());
+
+    ESP_LOGI(TAG, "wifi_init_sta finished.");
+
+    /* Waiting 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, "connected to ap SSID:%s password:%s",
+                 CONFIG_ESP_WIFI_SSID, CONFIG_ESP_WIFI_PASSWORD);
+    } else if (bits & WIFI_FAIL_BIT) {
+        ESP_LOGI(TAG, "Failed to connect to SSID:%s, password:%s",
+                 CONFIG_ESP_WIFI_SSID, CONFIG_ESP_WIFI_PASSWORD);
+    } else {
+        ESP_LOGE(TAG, "UNEXPECTED EVENT");
+    }
+}
+#else
+
+// If the SoC does not have WiFi capabilities, we can initialize a different network interface, this function is a placeholder for that purpose.
+// This function is also a no-op if EXAMPLE_WIFI_OVER_EPPP_CHANNEL==1, since the Wi-Fi network interface will live on the other peer (on the host side).
+void init_network_interface(void)
+{
+}
+
+#endif // SoC WiFi capable chip || WiFi over EPPP channel
+
+void station_over_eppp_channel(void *arg);
+
+void app_main(void)
+{
+    //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);
+
+    ESP_ERROR_CHECK(esp_netif_init());
+    ESP_ERROR_CHECK(esp_event_loop_create_default());
+    init_network_interface();   // WiFi station if withing SoC capabilities (otherwise a placeholder)
+
+    eppp_config_t config = EPPP_DEFAULT_SERVER_CONFIG();
+#if CONFIG_EPPP_LINK_DEVICE_SPI
+    config.transport = EPPP_TRANSPORT_SPI;
+    config.spi.is_master = false;
+    config.spi.host = CONFIG_EXAMPLE_SPI_HOST;
+    config.spi.mosi = CONFIG_EXAMPLE_SPI_MOSI_PIN;
+    config.spi.miso = CONFIG_EXAMPLE_SPI_MISO_PIN;
+    config.spi.sclk = CONFIG_EXAMPLE_SPI_SCLK_PIN;
+    config.spi.cs = CONFIG_EXAMPLE_SPI_CS_PIN;
+    config.spi.intr = CONFIG_EXAMPLE_SPI_INTR_PIN;
+    config.spi.freq = CONFIG_EXAMPLE_SPI_FREQUENCY;
+#elif CONFIG_EPPP_LINK_DEVICE_UART
+    config.transport = EPPP_TRANSPORT_UART;
+    config.uart.tx_io = CONFIG_EXAMPLE_UART_TX_PIN;
+    config.uart.rx_io = CONFIG_EXAMPLE_UART_RX_PIN;
+    config.uart.baud = CONFIG_EXAMPLE_UART_BAUDRATE;
+#elif CONFIG_EPPP_LINK_DEVICE_SDIO
+    config.transport = EPPP_TRANSPORT_SDIO;
+#endif // transport device
+
+    esp_netif_t *eppp_netif = eppp_listen(&config);
+    if (eppp_netif == NULL) {
+        ESP_LOGE(TAG, "Failed to setup connection");
+        return ;
+    }
+#ifdef CONFIG_EXAMPLE_WIFI_OVER_EPPP_CHANNEL
+    station_over_eppp_channel(eppp_netif);
+#else
+    ESP_ERROR_CHECK(esp_netif_napt_enable(eppp_netif));
+#endif // CONFIG_EXAMPLE_WIFI_OVER_EPPP_CHANNEL
+}

managed_components/espressif__eppp_link/examples/slave/main/idf_component.yml

@@ -0,0 +1,3 @@
+dependencies:
+  espressif/eppp_link:
+    version: '*'

managed_components/espressif__eppp_link/examples/slave/sdkconfig.ci.1

@@ -0,0 +1,4 @@
+CONFIG_IDF_TARGET="esp32s2"
+CONFIG_EPPP_LINK_DEVICE_SPI=y
+CONFIG_EPPP_LINK_CHANNELS_SUPPORT=y
+CONFIG_LWIP_PPP_VJ_HEADER_COMPRESSION=n

managed_components/espressif__eppp_link/examples/slave/sdkconfig.ci.2

@@ -0,0 +1,4 @@
+CONFIG_IDF_TARGET="esp32c2"
+CONFIG_EPPP_LINK_DEVICE_UART=y
+CONFIG_LWIP_PPP_VJ_HEADER_COMPRESSION=n
+CONFIG_EPPP_LINK_USES_PPP=y

managed_components/espressif__eppp_link/examples/slave/sdkconfig.ci.eth

@@ -0,0 +1,2 @@
+CONFIG_IDF_TARGET="esp32"
+CONFIG_EPPP_LINK_DEVICE_ETH=y

managed_components/espressif__eppp_link/examples/slave/sdkconfig.ci.ipv4_only

@@ -0,0 +1 @@
+CONFIG_LWIP_IPV6=n

managed_components/espressif__eppp_link/examples/slave/sdkconfig.ci.sdio

@@ -0,0 +1,2 @@
+CONFIG_IDF_TARGET="esp32c6"
+CONFIG_EPPP_LINK_DEVICE_SDIO=y

managed_components/espressif__eppp_link/examples/slave/sdkconfig.ci.spi

@@ -0,0 +1 @@
+CONFIG_EPPP_LINK_DEVICE_SPI=y

managed_components/espressif__eppp_link/examples/slave/sdkconfig.ci.uart

@@ -0,0 +1 @@
+CONFIG_EPPP_LINK_DEVICE_UART=y

managed_components/espressif__eppp_link/examples/slave/sdkconfig.defaults

@@ -0,0 +1,3 @@
+CONFIG_LWIP_IP_FORWARD=y
+CONFIG_LWIP_IPV4_NAPT=y
+CONFIG_LWIP_TCPIP_TASK_STACK_SIZE=4096