1、端口定义
/*组播套接字*/
SOCKET server;
2、创建组播组
BOOL CChatDlg::StartMulticastService()
{
WSAData wsaData;
::WSAStartup(MAKEWORD(2, 2), &wsaData);
/*建立套接字*/
server = socket(AF_INET, SOCK_DGRAM, 0);
/*允许端口可重复绑定*/
const int on = 1;
int ret = setsockopt(server, SOL_SOCKET, SO_REUSEADDR, (char *)&on, sizeof(on));
if (ret == SOCKET_ERROR)
{
WSACleanup();
return FALSE;
}
/*设置多播组数据的TTL值*/
const int routenum = 10;
ret = setsockopt(server, IPPROTO_IP, IP_MULTICAST_TTL, \
(char*)&routenum, sizeof(routenum));
if (ret == SOCKET_ERROR)
{
WSACleanup();
return FALSE;
}
/*设置回环许可*/
const int loopback = 1;
ret = setsockopt(server, IPPROTO_IP, IP_MULTICAST_LOOP, \
(char*)&loopback, sizeof(loopback));
if (ret == SOCKET_ERROR)
{
WSACleanup();
return FALSE;
}
sockaddr_in local;
memset(&local, 0, sizeof(local));;/*初始化组播地址为0*/
local.sin_family