本地domain套接字udp协议的客户端和服务器端互相发送接受消息的c语言代码

以下是一个简单的本地domain套接字udp协议的客户端和服务器端互相发送接受消息的c语言代码。

服务器端代码：

#include <stdio.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <unistd.h>

#define SOCKET_NAME "/tmp/udp_socket"

int main() {
    int server_fd;
    struct sockaddr_un server_addr;
    char buffer[1024] = {0};

    if ((server_fd = socket(AF_UNIX, SOCK_DGRAM, 0)) == -1) {
        perror("socket failed");
        return 1;
    }

    memset(&server_addr, 0, sizeof(struct sockaddr_un));
    server_addr.sun_family = AF_UNIX;
    strncpy(server_addr.sun_path, SOCKET_NAME, sizeof(server_addr.sun_path) - 1);

    if (bind(server_fd, (const struct sockaddr*) &server_addr, sizeof(struct sockaddr_un)) == -1) {
        perror("bind failed");
        close(server_fd);
        return 1;
    }

    while (1) {
        struct sockaddr_un client_addr;
        socklen_t len = sizeof(struct sockaddr_un);
        int n = recvfrom(server_fd, buffer, sizeof(buffer), 0, (struct sockaddr*) &client_addr, &len);
        if (n == -1) {
            perror("recvfrom failed");
            continue;
        }

        printf("Received message from client: %s\n", buffer);

        if (sendto(server_fd, "Hello from server", 18, 0, (struct sockaddr*) &client_addr, len) == -1) {
            perror("sendto failed");
        }
    }

    close(server_fd);
    unlink(SOCKET_NAME);

    return 0;
}

客户端代码：

#include <stdio.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <unistd.h>

#define SOCKET_NAME "/tmp/udp_socket"

int main() {
    int client_fd;
    struct sockaddr_un server_addr;
    char buffer[1024] = {0};

    if ((client_fd = socket(AF_UNIX, SOCK_DGRAM, 0)) == -1) {
        perror("socket failed");
        return 1;
    }

    memset(&server_addr, 0, sizeof(struct sockaddr_un));
    server_addr.sun_family = AF_UNIX;
    strncpy(server_addr.sun_path, SOCKET_NAME, sizeof(server_addr.sun_path) - 1);

    if (connect(client_fd, (const struct sockaddr*) &server_addr, sizeof(struct sockaddr_un)) == -1) {
        perror("connect failed");
        close(client_fd);
        return 1;
    }

    if (send(client_fd, "Hello from client", 18, 0) == -1) {
        perror("send failed");
        close(client_fd);
        return 1;
    }

    int n = read(client_fd, buffer, sizeof(buffer));
    if (n == -1) {
        perror("read failed");
        close(client_fd);
        return 1;
    }

    printf("Received message from server: %s\n", buffer);

    close(client_fd);

    return 0;
}

注意，这段代码使用了本地domain套接字，因此需要在服务器和客户端之间使用同一个地址。在这个例子中，我们使用了`/tmp/udp_socket`作为套接字地址。这个地址应该在客户端和服务器端代码中保持一致。