C语言 广播

广播地址:
xxx.xxx.xxx.255
255.255.255.255
网关:(不同局域网信息要通过网关)
xxx.xxx.xxx.1

server

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <arpa/inet.h>

int main(int argc, const char* argv[])
{
    // 创建套接字
    int fd = socket(AF_INET, SOCK_DGRAM, 0);
    struct sockaddr_in serv;//server端配置
    memset(&serv, 0, sizeof(serv));
    serv.sin_family  = AF_INET;
    serv.sin_port = htons(9999);    // server端口
    serv.sin_addr.s_addr = htonl(INADDR_ANY);
    int ret = bind(fd, (struct sockaddr*)&serv, sizeof(serv));//绑定端口
    struct sockaddr_in client;//client端配置
    memset(&client, 0, sizeof(client));
    client.sin_family = AF_INET;
    client.sin_port = htons(8888);  // 客户端要绑定的端口
    inet_pton(AF_INET, "192.168.1.255", &client.sin_addr.s_addr);
    int flag = 1;
    setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &flag, sizeof(flag));//给服务器开放广播权限
    while(1)
    {
        static int num = 0;
        char buf[1024] = {0};
        int ret = sendto(fd, buf, strlen(buf)+1, 0, (struct sockaddr*)&client, sizeof(client));
        printf("server == send buf: %s\n", buf);
        sleep(1);
    }
    close(fd);
    return 0;
}

client

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <arpa/inet.h>

int main(int argc, const char* argv[])
{
    int fd = socket(AF_INET, SOCK_DGRAM, 0);
    struct sockaddr_in client;//配置客户端
    memset(&client, 0, sizeof(client));
    client.sin_family = AF_INET;
    client.sin_port = htons(8888);  
    inet_pton(AF_INET, "0.0.0.0", &client.sin_addr.s_addr);
    int ret  = bind(fd, (struct sockaddr*)&client, sizeof(client));
    while(1)
    {
        char buf[1024] = {0};
        int len = recvfrom(fd, buf, sizeof(buf), 0, NULL, NULL);
        printf("client == recv buf: %s\n", buf);
    }
    close(fd);
    return 0;
}