同一局域网内通过发送广播，同网段IP都能收到信息

#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <pthread.h>
#include <string.h>
#include <stdlib.h>
int main(int argc, char const *argv[])
{    
int sockfd = socket(AF_INET, SOCK_DGRAM,0);
    //设置sockfd具备广播 功能    
    int yes = 1;    
    setsockopt(sockfd, SOL_SOCKET, SO_BROADCAST, &yes,sizeof(int));
    struct sockaddr_in dst_addr;    
    bzero(&dst_addr,sizeof(dst_addr));    
    dst_addr.sin_family = AF_INET;    
    dst_addr.sin_port = htons(8080);    
    dst_addr.sin_addr.s_addr = inet_addr("10.0.121.255");
    sendto(sockfd,"hehe",strlen("hehe"),0, (struct sockaddr *)&dst_addr,sizeof(dst_addr));
    close(sockfd);    
    return 0;
    }