【ESP32 WiFi篇（四）】ESP32 UDP服务端、客户端

UDP客户端

/* BSD Socket API 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 
#include 
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/event_groups.h"
#include "esp_system.h"
#include "esp_wifi.h"
#include "esp_event.h"
#include "esp_log.h"
#include "nvs_flash.h"
#include "esp_netif.h"
#include "protocol_examples_common.h"

#include "lwip/err.h"
#include "lwip/sockets.h"
#include "lwip/sys.h"
#include 
#include "addr_from_stdin.h"

#if defined(CONFIG_EXAMPLE_IPV4)
#define HOST_IP_ADDR "192.168.1.109"
#elif defined(CONFIG_EXAMPLE_IPV6)
#define HOST_IP_ADDR CONFIG_EXAMPLE_IPV6_ADDR
#else
#define HOST_IP_ADDR "192.168.1.109"
#endif

#define PORT 45454

static const char *TAG = "example";
static const char *payload = "I am Eiker_3169";


static void udp_client_task(void *pvParameters)
{
    char rx_buffer[128];
    char host_ip[] = HOST_IP_ADDR;
    int addr_family = 0;
    int ip_protocol = 0;

    while (1) {

#if defined(CONFIG_EXAMPLE_IPV4)
        struct sockaddr_in dest_addr;
        dest_addr.sin_addr.s_addr = inet_addr(HOST_IP_ADDR);
        dest_addr.sin_family = AF_INET;
        dest_addr.sin_port = htons(PORT);
        addr_family = AF_INET;
        ip_protocol = IPPROTO_IP;
#elif defined(CONFIG_EXAMPLE_IPV6)
        struct sockaddr_in6 dest_addr = { 0 };
        inet6_aton(HOST_IP_ADDR, &dest_addr.sin6_addr);
        dest_addr.sin6_family = AF_INET6;
        dest_addr.sin6_port = htons(PORT);
        dest_addr.sin6_scope_id = esp_netif_get_netif_impl_index(EXAMPLE_INTERFACE);
        addr_family = AF_INET6;
        ip_protocol = IPPROTO_IPV6;
#elif defined(CONFIG_EXAMPLE_SOCKET_IP_INPUT_STDIN)
        struct sockaddr_storage dest_addr = { 0 };
        ESP_ERROR_CHECK(get_addr_from_stdin(PORT, SOCK_DGRAM, &ip_protocol, &addr_family, &dest_addr));
#endif

        int sock = socket(addr_family, SOCK_DGRAM, ip_protocol);
        if (sock < 0) {
            ESP_LOGE(TAG, "Unable to create socket: errno %d", errno);
            break;
        }
        ESP_LOGI(TAG, "Socket created, sending to %s:%d", HOST_IP_ADDR, PORT);

        int err = sendto(sock, payload, strlen(payload), 0, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
            if (err < 0) {
                ESP_LOGE(TAG, "Error occurred during sending: errno %d", errno);
                break;
            }
            ESP_LOGI(TAG, "Message sent");

        while (1) {

            struct sockaddr_storage source_addr; // Large enough for both IPv4 or IPv6
            socklen_t socklen = sizeof(source_addr);
            int len = recvfrom(sock, rx_buffer, sizeof(rx_buffer) - 1, 0, (struct sockaddr *)&source_addr, &socklen);

            // Error occurred during receiving
            if (len < 0) {
                ESP_LOGE(TAG, "recvfrom failed: errno %d", errno);
                break;
            }
            // Data received
            else {
                rx_buffer[len] = 0; // Null-terminate whatever we received and treat like a string
                ESP_LOGI(TAG, "Received %d bytes from %s:", len, host_ip);
                ESP_LOGI(TAG, "%s", rx_buffer);
                if (strncmp(rx_buffer, "reset", 5) == 0) {
                    ESP_LOGI(TAG, "Received expected message, re-init");
                    break;
                }
                else{
                    err = sendto(sock, rx_buffer, len, 0, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
                    if (err < 0) {
                        ESP_LOGE(TAG, "Error occurred during sending: errno %d", errno);
                        break;
                    }
                }
            }

            vTaskDelay(2000 / portTICK_PERIOD_MS);
        }

        if (sock != -1) {
            ESP_LOGE(TAG, "Shutting down socket and restarting...");
            shutdown(sock, 0);
            close(sock);
        }
    }
    vTaskDelete(NULL);
}

void app_main(void)
{
    ESP_ERROR_CHECK(nvs_flash_init());
    ESP_ERROR_CHECK(esp_netif_init());
    ESP_ERROR_CHECK(esp_event_loop_create_default());

    /* This helper function configures Wi-Fi or Ethernet, as selected in menuconfig.
     * Read "Establishing Wi-Fi or Ethernet Connection" section in
     * examples/protocols/README.md for more information about this function.
     */
    ESP_ERROR_CHECK(example_connect());

    xTaskCreate(udp_client_task, "udp_client", 4096, NULL, 5, NULL);
}

UDP服务端

/* BSD Socket API 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 
#include 
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_system.h"
#include "esp_wifi.h"
#include "esp_event.h"
#include "esp_log.h"
#include "nvs_flash.h"
#include "esp_netif.h"
#include "protocol_examples_common.h"

#include "lwip/err.h"
#include "lwip/sockets.h"
#include "lwip/sys.h"
#include 

#define PORT CONFIG_EXAMPLE_PORT

static const char *TAG = "example";

static void udp_server_task(void *pvParameters)
{
    char rx_buffer[128];
    char addr_str[128];
    int addr_family = (int)pvParameters;
    int ip_protocol = 0;
    struct sockaddr_in6 dest_addr;

    while (1) {

        if (addr_family == AF_INET) {
            struct sockaddr_in *dest_addr_ip4 = (struct sockaddr_in *)&dest_addr;
            dest_addr_ip4->sin_addr.s_addr = htonl(INADDR_ANY);
            dest_addr_ip4->sin_family = AF_INET;
            dest_addr_ip4->sin_port = htons(PORT);
            ip_protocol = IPPROTO_IP;
        } else if (addr_family == AF_INET6) {
            bzero(&dest_addr.sin6_addr.un, sizeof(dest_addr.sin6_addr.un));
            dest_addr.sin6_family = AF_INET6;
            dest_addr.sin6_port = htons(PORT);
            ip_protocol = IPPROTO_IPV6;
        }

        int sock = socket(addr_family, SOCK_DGRAM, ip_protocol);
        if (sock < 0) {
            ESP_LOGE(TAG, "Unable to create socket: errno %d", errno);
            break;
        }
        ESP_LOGI(TAG, "Socket created");

#if defined(CONFIG_EXAMPLE_IPV4) && defined(CONFIG_EXAMPLE_IPV6)
        if (addr_family == AF_INET6) {
            // Note that by default IPV6 binds to both protocols, it is must be disabled
            // if both protocols used at the same time (used in CI)
            int opt = 1;
            setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
            setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &opt, sizeof(opt));
        }
#endif

        int err = bind(sock, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
        if (err < 0) {
            ESP_LOGE(TAG, "Socket unable to bind: errno %d", errno);
        }
        ESP_LOGI(TAG, "Socket bound, port %d", PORT);

        while (1) {

            ESP_LOGI(TAG, "Waiting for data");
            struct sockaddr_storage source_addr; // Large enough for both IPv4 or IPv6
            socklen_t socklen = sizeof(source_addr);
            int len = recvfrom(sock, rx_buffer, sizeof(rx_buffer) - 1, 0, (struct sockaddr *)&source_addr, &socklen);

            // Error occurred during receiving
            if (len < 0) {
                ESP_LOGE(TAG, "recvfrom failed: errno %d", errno);
                break;
            }
            // Data received
            else {
                // Get the sender's ip address as string
                if (source_addr.ss_family == PF_INET) {
                    inet_ntoa_r(((struct sockaddr_in *)&source_addr)->sin_addr, addr_str, sizeof(addr_str) - 1);
                } else if (source_addr.ss_family == PF_INET6) {
                    inet6_ntoa_r(((struct sockaddr_in6 *)&source_addr)->sin6_addr, addr_str, sizeof(addr_str) - 1);
                }

                u16_t iPort = ntohs(((struct sockaddr_in6 *)&source_addr)->sin6_port);

                rx_buffer[len] = 0; // Null-terminate whatever we received and treat like a string...
                ESP_LOGI(TAG, "Received %d bytes from IP:%s  Port:%d", len, addr_str, iPort);
                ESP_LOGI(TAG, "%s", rx_buffer);

                int err = sendto(sock, rx_buffer, len, 0, (struct sockaddr *)&source_addr, sizeof(source_addr));
                if (err < 0) {
                    ESP_LOGE(TAG, "Error occurred during sending: errno %d", errno);
                    break;
                }
            }
        }

        if (sock != -1) {
            ESP_LOGE(TAG, "Shutting down socket and restarting...");
            shutdown(sock, 0);
            close(sock);
        }
    }
    vTaskDelete(NULL);
}

void app_main(void)
{
    ESP_ERROR_CHECK(nvs_flash_init());
    ESP_ERROR_CHECK(esp_netif_init());
    ESP_ERROR_CHECK(esp_event_loop_create_default());

    /* This helper function configures Wi-Fi or Ethernet, as selected in menuconfig.
     * Read "Establishing Wi-Fi or Ethernet Connection" section in
     * examples/protocols/README.md for more information about this function.
     */
    ESP_ERROR_CHECK(example_connect());

#ifdef CONFIG_EXAMPLE_IPV4
    xTaskCreate(udp_server_task, "udp_server", 4096, (void*)AF_INET, 5, NULL);
#endif
#ifdef CONFIG_EXAMPLE_IPV6
    xTaskCreate(udp_server_task, "udp_server", 4096, (void*)AF_INET6, 5, NULL);
#endif

}