udp接收不到广播包

发布于 2020-12-14 17:58:41 浏览：2551 订阅该版

想让板子能够接收广播包，返回板子的一些信息，调试的时候udp不能接收到电脑发送的广播包，不知道为啥，请问有人做过吗？能请教一下吗？已经关闭防火墙，电脑直连也不行。
```c
static int udp_broadcase(void)
{
    int sockListen;
    
	if((sockListen = socket(AF_INET, SOCK_DGRAM, 0)) == -1){
		printf("socket fail\n");
		return -1;
	}
    
	int set = 1;
	setsockopt(sockListen, SOL_SOCKET, SO_BROADCAST|SO_REUSEADDR, &set, sizeof(int));
	
    struct sockaddr_in recvAddr;
	memset(&recvAddr, 0, sizeof(struct sockaddr_in));
	recvAddr.sin_family = AF_INET;
	recvAddr.sin_port = htons(4001);
	recvAddr.sin_addr.s_addr = INADDR_ANY;
	
	if(bind(sockListen, (struct sockaddr *)&recvAddr, sizeof(struct sockaddr)) == -1)
    {
		printf("bind fail\n");
		return -1;
	}
	
    int recvbytes;
	char recvbuf[128];
	socklen_t addrLen = sizeof(struct sockaddr_in);
	if((recvbytes = recvfrom(sockListen, recvbuf, 128, 0, (struct sockaddr *)&recvAddr, &addrLen)) != -1)
    {
		recvbuf[recvbytes] = '\0';
		rt_kprintf("receive a broadCast messgse:%s\n", recvbuf);
	}
    else
    {
		rt_kprintf("recvfrom fail\n");
	}
    
	closesocket(sockListen);
	return 0;
}
MSH_CMD_EXPORT(udp_broadcase, udp);
```