UDP广播在Windows 7 - 它的工作原理？ [英] UDP Broadcast in Windows 7 - does it work?

问题描述

我试着写在Windows 7下一些code在我的本地网络广播和不能得到以下code工作。我来自一个Linux背景，使道歉的风格 - 满code编译等，并与工作如果我使用的地址：

I'm trying to write some code under Windows 7 to broadcast across my local network and can't get the following code to work. I come from a Linux background so apologies for style - the full code compiles etc and works and if I use an address of:

unsigned long broadcastAddr = inet_addr("192.168.10.0") | ~(inet_addr("255.255.240.0"));

然后就是做工精细，我只是真的想用preferred INADDR_BROADCAST / 255.255.255.255方法。

Then that works fine, I just would really like to use the preferred INADDR_BROADCAST/255.255.255.255 method.

<snip>
SOCKET sockfd;
int broadcast = 1;

WSADATA wsaData;    // Windows socket

// Initialize Winsock
if (WSAStartup(MAKEWORD(2,2), &wsaData) == SOCKET_ERROR) {
    perror("WinSock Error");
    getc(stdin);
    exit(EXIT_FAILURE);
}
if ((sockfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP)) == -1) {
    perror("Socket Error");
    getc(stdin);
        exit(1);
}

if ((setsockopt(sockfd, SOL_SOCKET, SO_BROADCAST, (char *)&broadcast, sizeof(broadcast))) == SOCKET_ERROR) {
    perror("Setsockopt - SOL_SOCKET");
    getc(stdin);
    exit(1);
}

struct sockaddr_in recvaddr;
recvaddr.sin_family = AF_INET;
recvaddr.sin_port = htons(PORT);
recvaddr.sin_addr.s_addr = htonl(INADDR_BROADCAST);
memset(recvaddr.sin_zero,'\0', sizeof(recvaddr.sin_zero));

int numbytes = 0;
while ((numbytes = sendto(sockfd, greet, strlen(greet) , MSG_DONTROUTE, (struct sockaddr *)&recvaddr, sizeof(struct sockaddr_in))) != -1) {
        printf("Sent a packet %d\n", numbytes);
        Sleep(100);
}

推荐答案

有是Windows 7 UDP广播一个巨大的错误，这使得上255.255.255.255广播上的最的Windows 7中不起作用安装： <一href=\"http://serverfault.com/questions/72112/how-to-alter-the-global-broadcast-address-255-255-255-255-behavior-on-windows\">http://serverfault.com/questions/72112/how-to-alter-the-global-broadcast-address-255-255-255-255-behavior-on-windows

There is a huge bug in Windows 7 for UDP broadcast which makes broadcasting on 255.255.255.255 not work on most windows 7 install: http://serverfault.com/questions/72112/how-to-alter-the-global-broadcast-address-255-255-255-255-behavior-on-windows

基本上，它只能在单个网络接口发送所述广播，它可以是任何东西，甚至像虚拟机的网络接口或蓝牙一个，这可以最终不广播任何设备

Basically it will send the broadcast only on a single network interface, which could be anything, even something like a VM network interface or bluetooth one, which can end up not broadcasting to any device.

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