UDP-多播练习

使用udp实现多播通信，加入到多播组的成员之间可以发送消息，组内成员均可接受到

/**************************************************************************
*
* 设计多播通信程序，服务器向网段内的所有主机发送消息
* author：jindouliu2024@163.com 
* date：2025.5.15
* 
*
* Copyright (c)  2024-2025   jindouliu2024@163.com   All right Reserved
* *************************************************************************/

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

#define MULTIADDR   224.224.224.244  //D类地址
#define LOCALADDR   192.168.1.160
#define PORT		6666

pthread_t task1_id;
pthread_t task2_id;
int udp_socket;
char *data[4];
//向广播地址发送数据
void * task1(void *arg)
{
	//绑定广播的端口和地址
	struct sockaddr_in server_addr;
	server_addr.sin_family = AF_INET;
	server_addr.sin_port = htons(PORT);
	server_addr.sin_addr.s_addr = inet_addr(MULTIADDR);
	char buf[128] = "this is task1,server sending";
	while(1){
		//发送数据
		sendto(udp_socket,buf,strlen(buf),0,(struct sockaddr *)&server_addr,sizeof(server_addr));
		sleep(10);
	}
	pthread_exit(NULL);
}
//接收数据
void * task2(void *arg)
{
	char buf[128] = {0};
	//绑定客户端的端口和地址
	struct sockaddr_in client;
	client.sin_family = AF_INET;
	client.sin_port = htons(PORT);
	client.sin_addr.s_addr = inet_addr(LOCALADDR);
	bind(udp_socket,(struct sockaddr *)&client,sizeof(client));

	struct sockaddr_in server;
	socklen_t server_size = sizeof(server);
	while(1){
		//准备接受数据
		recvfrom(udp_socket,buf,sizeof(buf),0,(struct sockaddr *)&server,&server_size);
		printf("server data is %s\n",buf);
		bzero(buf,sizeof(buf));

	}
	
	pthread_exit(NULL);
}

int main(int argc,char *argv[])
{
	
	//创建一个网络套接字
	udp_socket = socket(AF_INET,SOCK_DGRAM,0);
	if(udp_socket == -1){
		fprintf(stderr,"socket error errno:%d,%s",errno,strerror(errno));
		return 1;
	}
	//设置广播属性
	struct ip_mreq ip_opt;
	ip_opt.imr_multiaddr.s_addr = inet_addr(MULTIADDR);
	ip_opt.imr_address.s_addr = inet_addr(LOCALADDR);
	setsockopt(udp_socket,IPPROTO_IP,IP_ADD_MEMBERSHIP,&ip_opt,sizeof(ip_opt));
	
	//创建两个线程，一个用于发送一个用于接受
	pthread_create(&task1_id,NULL,task1,NULL);
	pthread_create(&task2_id,NULL,task2,NULL);

	pthread_exit(NULL);
	
	return 0;
}