linux udp 广播收发

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>

#define BROADCAST_PORT 8888
#define BROADCAST_IP "192.168.1.255"
#define BUFFER_SIZE 1024

int main() {
    int sockfd;
    struct sockaddr_in broadcastAddr;
    char *buffer = "Hello, this is a UDP broadcast message!";

    // 创建UDP套接字
    if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
        perror("socket");
        exit(1);
    }

    // 设置套接字可广播
    int broadcastEnable = 1;
    int ret = setsockopt(sockfd, SOL_SOCKET, SO_BROADCAST, &broadcastEnable, sizeof(broadcastEnable));
    if (ret < 0) {
        perror("setsockopt");
        close(sockfd);
        exit(1);
    }

    // 配置广播地址结构
    memset(&broadcastAddr, 0, sizeof(broadcastAddr));
    broadcastAddr.sin_family = AF_INET;
    broadcastAddr.sin_port = htons(BROADCAST_PORT);
    inet_pton(AF_INET, BROADCAST_IP, &broadcastAddr.sin_addr);

    // 发送广播消息
    if (sendto(sockfd, buffer, strlen(buffer), 0, (struct sockaddr *)&broadcastAddr, sizeof(broadcastAddr)) < 0) {
        perror("sendto");
        close(sockfd);
        exit(1);
    }

    close(sockfd);
    return 0;
}

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/socket.h>
#include <netinet/in.h>

#define BROADCAST_PORT 8888
#define BUFFER_SIZE 1024

int main() {
    int sockfd;
    struct sockaddr_in serverAddr, clientAddr;
    socklen_t addrLen = sizeof(clientAddr);
    char buffer[BUFFER_SIZE];

    // 创建UDP套接字
    if ((sockfd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) {
        perror("socket");
        exit(1);
    }

    // 配置服务器地址结构
    memset(&serverAddr, 0, sizeof(serverAddr));
    serverAddr.sin_family = AF_INET;
    serverAddr.sin_port = htons(BROADCAST_PORT);
    serverAddr.sin_addr.s_addr = htonl(INADDR_ANY);

    // 绑定套接字到指定端口
    if (bind(sockfd, (struct sockaddr *)&serverAddr, sizeof(serverAddr)) < 0) {
        perror("bind");
        close(sockfd);
        exit(1);
    }

    // 接收广播消息
    int recvLen = recvfrom(sockfd, buffer, BUFFER_SIZE, 0, (struct sockaddr *)&clientAddr, &addrLen);
    if (recvLen < 0) {
        perror("recvfrom");
        close(sockfd);
        exit(1);
    }

    buffer[recvLen] = '\0';
    printf("Received broadcast message: %s
", buffer);

    close(sockfd);
    return 0;
}