单播组播共用一个端口号

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原创最新推荐文章于 2026-05-18 14:22:52 发布 2.4k 阅读 AI 写同款· GEO 优化 ›

Java实现单播，组播，广播单播、组播、广播介绍：https://blog.youkuaiyun.com/ahou2468/article/details/86526509 目录 1.单播、组播、广播关键类说明 2.单播和广播的具体实现 2.1定义套接字管理类 2.2单播或者广播发送数据包类 2.3.单播或者广播接收数据包监听 3.组播的具体实现 3.1定义套接字管理类 3.2组播发送数据包类 3.3组播接收数... 阅读详情

让同一个端口号，既可以接收单播也可以接收组播的方法！

/*************************************************************************
  > File Name: udp.c
  > Author: huochuanfei
  > Mail: 597092440@qq.com 
  > Created Time: 2021-05-21 14:22:28
 ************************************************************************/

#include <stdio.h>
#include <string.h>
#include <inttypes.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <linux/sockios.h>
#include <linux/if.h>
#include <stdlib.h>


int sockfd = 0;

/**********************************************
 * function: create_mul_fd
 * Author: huochuanfei
 * Mail: 597092440@qq.com
 * Created Time: 2020-11-10
*********************************************/
static int create_mul_fd(int port, uint32_t ip)
{
	int fd = 0;
	int loop = 1;
	struct ifreq ifq;
	struct ip_mreq mreq;
	struct sockaddr_in addr;
	memset((char*)&addr, 0x0, sizeof(struct sockaddr_in));
	strncpy(ifq.ifr_name, "wlp3s0", IFNAMSIZ);
	if ((fd = socket(AF_INET, SOCK_DGRAM ,0)) <= 0) {
		printf("socket:%m\n");
		exit(1);
	}
	int yes = 1;
	if (setsockopt(fd,SOL_SOCKET,SO_REUSEADDR,&yes,sizeof(yes)) < 0) {    
		perror("Reusing ADDR failed");    
		exit(1);    
	}

	addr.sin_family = AF_INET;
	addr.sin_port = htons(port);
	addr.sin_addr.s_addr = htonl(INADDR_ANY);/* 很关键，不能绑定具体IP */
	if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP, &loop, sizeof(loop)) < 0) {
		printf("setsockopt");
		exit(1);
	}
	if (bind(fd, (struct sockaddr*)&addr, sizeof(struct sockaddr)) < 0) {
		printf("bind2:%m\n");
		exit(1);
	}
	mreq.imr_multiaddr.s_addr = ip;
	mreq.imr_interface.s_addr = inet_addr("192.168.1.66");
	if (setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mreq, sizeof(mreq)) < 0) {
		printf("setsockopt");
		exit(1);
	}

	return fd;
}

int main() {
	sockfd = create_mul_fd(9999, inet_addr("224.9.9.9"));
	if (sockfd < 0) {
		printf("listen_mult: %d\n", sockfd);
		return -1;
	}
	char buf[1024] = {0};
	int ret = 0;

	while (1) {
		memset(buf, 0x0, sizeof(buf));
		ret = recv(sockfd, buf, sizeof(buf), 0);
		printf("%d: %s\n", ret, buf);
	}


	return 0;
}