文章來源:
http://www.cnblogs.com/Clingingboy/archive/2011/06/21/2086349.html
2011-06-21 20:16 by Clingingboy
一.廣播
1.接收
void main()
{
SOCKET s = ::socket(AF_INET, SOCK_DGRAM, 0);
// 首先要綁定一個本地地址,指明廣播端口號
SOCKADDR_IN sin;
sin.sin_family = AF_INET;
sin.sin_addr.S_un.S_addr = INADDR_ANY;
sin.sin_port = ::ntohs(4567);
if(::bind(s, (sockaddr*)&sin, sizeof(sin)) == SOCKET_ERROR)
{
printf(" bind() failed \n");
return;
}
// 接收廣播
printf(" 開始在4567端口接收廣播數據... \n\n");
SOCKADDR_IN addrRemote;
int nLen = sizeof(addrRemote);
char sz[256];
while(TRUE)
{
int nRet = ::recvfrom(s, sz, 256, 0, (sockaddr*)&addrRemote, &nLen);
if(nRet > 0)
{
sz[nRet] = '\0';
printf(sz);
}
}
}
2.發送
void main()
{
SOCKET s = ::socket(AF_INET, SOCK_DGRAM, 0);
// 有效SO_BROADCAST選項
BOOL bBroadcast = TRUE;
::setsockopt(s, SOL_SOCKET, SO_BROADCAST, (char*)&bBroadcast, sizeof(BOOL));
// 設置廣播地址,這裏的廣播端口號(電臺)是4567
SOCKADDR_IN bcast;
bcast.sin_family = AF_INET;
bcast.sin_addr.s_addr = INADDR_BROADCAST; // ::inet_addr("255.255.255.255");
bcast.sin_port = htons(4567);
// 發送廣播
printf(" 開始向4567端口發送廣播數據... \n \n");
char sz[] = "This is just a test. \r\n";
while(TRUE)
{
::sendto(s, sz, strlen(sz), 0, (sockaddr*)&bcast, sizeof(bcast));
::Sleep(5000);
}
}
二.IP多播
1.加入多播組並接收數據
void main()
{
SOCKET s = ::socket(AF_INET, SOCK_DGRAM, 0);
// 允許其它進程使用綁定的地址
BOOL bReuse = TRUE;
::setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (char*)&bReuse, sizeof(BOOL));
// 綁定到4567端口
sockaddr_in si;
si.sin_family = AF_INET;
si.sin_port = ::ntohs(4567);
si.sin_addr.S_un.S_addr = INADDR_ANY;
::bind(s, (sockaddr*)&si, sizeof(si));
// 加入多播組
ip_mreq mcast;
mcast.imr_interface.S_un.S_addr = INADDR_ANY;
mcast.imr_multiaddr.S_un.S_addr = ::inet_addr("234.5.6.7"); // 多播地址爲234.5.6.7
::setsockopt(s, IPPROTO_IP, IP_ADD_MEMBERSHIP, (char*)&mcast, sizeof(mcast));
// 接收多播組數據
printf(" 開始接收多播組234.5.6.7上的數據... \n");
char buf[1280];
int nAddrLen = sizeof(si);
while(TRUE)
{
int nRet = ::recvfrom(s, buf, strlen(buf), 0, (sockaddr*)&si, &nAddrLen);
if(nRet != SOCKET_ERROR)
{
buf[nRet] = '\0';
printf(buf);
}
else
{
int n = ::WSAGetLastError();
break;
}
}
}
2.發送廣播
同上
設置SO_REUSEADDR,則允許多個進程綁定到這個端號,這樣加入到同個端口的組都可以接收到數據
三.源地址的IP多播
即可指定接收組內特定IP地址的消息
c#參考:http://www.cnblogs.com/xuhx/archive/2004/06/23/18150.html
http://www.cnblogs.com/xuhx/archive/2004/06/27/18960.html
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