esp-idf/examples/ethernet/eth2ap/main/eth2ap_example_main.c

/* eth2ap (Ethernet to Wi-Fi AP packet forwarding) 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 <stdlib.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/queue.h"
#include "esp_event_loop.h"
#include "esp_event.h"
#include "esp_log.h"
#include "esp_eth.h"
#include "esp_wifi.h"
#include "nvs_flash.h"
#include "esp_private/wifi.h"
#include "driver/gpio.h"
#include "sdkconfig.h"

// Choose the default phy config according to Kconfig
#if CONFIG_EXAMPLE_PHY_LAN8720
#include "eth_phy/phy_lan8720.h"
#define DEFAULT_ETHERNET_PHY_CONFIG phy_lan8720_default_ethernet_config
#elif CONFIG_EXAMPLE_PHY_TLK110
#include "eth_phy/phy_tlk110.h"
#define DEFAULT_ETHERNET_PHY_CONFIG phy_tlk110_default_ethernet_config
#elif CONFIG_EXAMPLE_PHY_IP101
#include "eth_phy/phy_ip101.h"
#define DEFAULT_ETHERNET_PHY_CONFIG phy_ip101_default_ethernet_config
#endif

#define FLOW_CONTROL_QUEUE_TIMEOUT_MS (100)
#define FLOW_CONTROL_QUEUE_LENGTH (10)
#define FLOW_CONTROL_WIFI_SEND_TIMEOUT_MS (100)

static const char *TAG = "example";

typedef struct {
    void *packet;
    uint16_t length;
} flow_control_msg_t;

static xQueueHandle flow_control_queue = NULL;

static bool s_sta_is_connected = false;
static bool s_ethernet_is_connected = false;
static uint8_t s_eth_mac[6];

#ifdef CONFIG_EXAMPLE_PHY_USE_POWER_PIN
/**
 * @brief power control function for phy
 *
 * @param enable: set true to enable PHY power, set false to disable PHY power
 *
 * @note This function replaces the default PHY power on/off function.
 * If this GPIO is not connected on your device (and PHY is always powered),
 * you can use the default PHY-specific power on/off function.
 */
static void phy_device_power_enable_via_gpio(bool enable)
{
    assert(DEFAULT_ETHERNET_PHY_CONFIG.phy_power_enable);
    if (!enable) {
        /* call the default PHY-specific power off function */
        DEFAULT_ETHERNET_PHY_CONFIG.phy_power_enable(false);
    }
    gpio_pad_select_gpio(CONFIG_EXAMPLE_PHY_POWER_PIN);
    gpio_set_direction(CONFIG_EXAMPLE_PHY_POWER_PIN, GPIO_MODE_OUTPUT);
    if (enable) {
        gpio_set_level(CONFIG_EXAMPLE_PHY_POWER_PIN, 1);
        ESP_LOGI(TAG, "Power On Ethernet PHY");
    } else {
        gpio_set_level(CONFIG_EXAMPLE_PHY_POWER_PIN, 0);
        ESP_LOGI(TAG, "Power Off Ethernet PHY");
    }
    vTaskDelay(1);
    if (enable) {
        /* call the default PHY-specific power on function */
        DEFAULT_ETHERNET_PHY_CONFIG.phy_power_enable(true);
    }
}
#endif

/**
 * @brief gpio specific init
 *
 * @note RMII data pins are fixed in esp32 as follows:
 * TXD0 <=> GPIO19
 * TXD1 <=> GPIO22
 * TX_EN <=> GPIO21
 * RXD0 <=> GPIO25
 * RXD1 <=> GPIO26
 * CLK <=> GPIO0
 *
 */
static void eth_gpio_config_rmii(void)
{
    phy_rmii_configure_data_interface_pins();
    phy_rmii_smi_configure_pins(CONFIG_EXAMPLE_PHY_SMI_MDC_PIN, CONFIG_EXAMPLE_PHY_SMI_MDIO_PIN);
}

// Forward packets from Wi-Fi to Ethernet
static esp_err_t pkt_wifi2eth(void *buffer, uint16_t len, void *eb)
{
    if (s_ethernet_is_connected) {
        if (esp_eth_tx(buffer, len) != ESP_OK) {
            ESP_LOGE(TAG, "Ethernet send packet failed");
        }
    }
    esp_wifi_internal_free_rx_buffer(eb);
    return ESP_OK;
}

// Forward packets from Ethernet to Wi-Fi
// Note that, Ethernet works faster than Wi-Fi on ESP32,
// so we need to add an extra queue to balance their speed difference.
static esp_err_t pkt_eth2wifi(void *buffer, uint16_t len, void *eb)
{
    esp_err_t ret = ESP_OK;
    flow_control_msg_t msg = {
        .packet = buffer,
        .length = len
    };
    if (xQueueSend(flow_control_queue, &msg, pdMS_TO_TICKS(FLOW_CONTROL_QUEUE_TIMEOUT_MS)) != pdTRUE) {
        ESP_LOGE(TAG, "send flow control message failed or timeout");
        ret = ESP_FAIL;
    }
    return ret;
}

// This task will fetch the packet from the queue, and then send out through Wi-Fi.
// Wi-Fi handles packets slower than Ethernet, we might add some delay between each transmitting.
static void eth2wifi_flow_control_task(void *args)
{
    flow_control_msg_t msg;
    int res = 0;
    uint32_t timeout = 0;
    while (1) {
        if (xQueueReceive(flow_control_queue, &msg, pdMS_TO_TICKS(FLOW_CONTROL_QUEUE_TIMEOUT_MS)) == pdTRUE) {
            timeout = 0;
            if (s_sta_is_connected && msg.length > 4) {
                do {
                    vTaskDelay(pdMS_TO_TICKS(timeout));
                    timeout += 2;
                    res = esp_wifi_internal_tx(ESP_IF_WIFI_AP, msg.packet, msg.length - 4);
                } while (res == -1 && timeout < FLOW_CONTROL_WIFI_SEND_TIMEOUT_MS);
                if (res != ESP_OK) {
                    ESP_LOGE(TAG, "WiFi send packet failed: %d", res);
                }
            }
            esp_eth_free_rx_buf(msg.packet);
        }
    }
    vTaskDelete(NULL);
}

// Event handler for Ethernet
static void eth_event_handler(void *arg, esp_event_base_t event_base,
                              int32_t event_id, void *event_data)
{
    switch (event_id) {
    case ETHERNET_EVENT_CONNECTED:
        ESP_LOGI(TAG, "Ethernet Link Up");
        s_ethernet_is_connected = true;
        esp_eth_get_mac(s_eth_mac);
        esp_wifi_set_mac(WIFI_IF_AP, s_eth_mac);
        ESP_ERROR_CHECK(esp_wifi_start());
        break;
    case ETHERNET_EVENT_DISCONNECTED:
        ESP_LOGI(TAG, "Ethernet Link Down");
        s_ethernet_is_connected = false;
        ESP_ERROR_CHECK(esp_wifi_stop());
        break;
    case ETHERNET_EVENT_START:
        ESP_LOGI(TAG, "Ethernet Started");
        break;
    case ETHERNET_EVENT_STOP:
        ESP_LOGI(TAG, "Ethernet Stopped");
        break;
    default:
        break;
    }
}

// Event handler for Wi-Fi
static void wifi_event_handler(void *arg, esp_event_base_t event_base,
                               int32_t event_id, void *event_data)
{
    switch (event_id) {
    case WIFI_EVENT_AP_STACONNECTED:
        ESP_LOGI(TAG, "Wi-Fi AP got a station connected");
        s_sta_is_connected = true;
        esp_wifi_internal_reg_rxcb(ESP_IF_WIFI_AP, pkt_wifi2eth);
        break;
    case WIFI_EVENT_AP_STADISCONNECTED:
        ESP_LOGI(TAG, "Wi-Fi AP got a station disconnected");
        s_sta_is_connected = false;
        esp_wifi_internal_reg_rxcb(ESP_IF_WIFI_AP, NULL);
        break;
    default:
        break;
    }
}

static void initialize_ethernet(void)
{
    eth_config_t config = DEFAULT_ETHERNET_PHY_CONFIG;
    config.phy_addr = CONFIG_EXAMPLE_PHY_ADDRESS;
    config.gpio_config = eth_gpio_config_rmii;
    config.clock_mode = CONFIG_EXAMPLE_PHY_CLOCK_MODE;
    config.tcpip_input = pkt_eth2wifi;
    config.promiscuous_enable = true;
#ifdef CONFIG_EXAMPLE_PHY_USE_POWER_PIN
    /* Replace the default 'power enable' function with an example-specific one that toggles a power GPIO. */
    config.phy_power_enable = phy_device_power_enable_via_gpio;
#endif
    ESP_ERROR_CHECK(esp_event_handler_register(ETH_EVENT, ESP_EVENT_ANY_ID, eth_event_handler, NULL));
    ESP_ERROR_CHECK(esp_eth_init_internal(&config));
    ESP_ERROR_CHECK(esp_eth_enable());
}

static void initialize_wifi(void)
{
    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
    ESP_ERROR_CHECK(esp_event_handler_register(WIFI_EVENT, ESP_EVENT_ANY_ID, wifi_event_handler, NULL));
    ESP_ERROR_CHECK(esp_wifi_init_internal(&cfg));
    ESP_ERROR_CHECK(esp_wifi_set_storage(WIFI_STORAGE_RAM));
    wifi_config_t wifi_config = {
        .ap = {
            .ssid = CONFIG_EXAMPLE_WIFI_SSID,
            .ssid_len = strlen(CONFIG_EXAMPLE_WIFI_SSID),
            .password = CONFIG_EXAMPLE_WIFI_PASSWORD,
            .max_connection = CONFIG_EXAMPLE_MAX_STA_CONN,
            .authmode = WIFI_AUTH_WPA_WPA2_PSK
        },
    };
    if (strlen(CONFIG_EXAMPLE_WIFI_PASSWORD) == 0) {
        wifi_config.ap.authmode = WIFI_AUTH_OPEN;
    }
    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_AP));
    ESP_ERROR_CHECK(esp_wifi_set_config(ESP_IF_WIFI_AP, &wifi_config));
}

static esp_err_t initialize_flow_control(void)
{
    flow_control_queue = xQueueCreate(FLOW_CONTROL_QUEUE_LENGTH, sizeof(flow_control_msg_t));
    if (!flow_control_queue) {
        ESP_LOGE(TAG, "create flow control queue failed");
        return ESP_FAIL;
    }
    BaseType_t ret = xTaskCreate(eth2wifi_flow_control_task, "flow_ctl", 2048, NULL, (tskIDLE_PRIORITY + 2), NULL);
    if (ret != pdTRUE) {
        ESP_LOGE(TAG, "create flow control task failed");
        return ESP_FAIL;
    }
    return ESP_OK;
}

void app_main()
{
    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_event_loop_create_default());
    ESP_ERROR_CHECK(initialize_flow_control());

    initialize_ethernet();
    initialize_wifi();
}