Multicast

Лекгий глюк в УДП мультикастинге: клиент принимает не посланный другим компьютером пакет, а последний покет, посланный им самим. Вот исходник инициализации:

if(Initialized)return ALREADYINIT;
if(Chanell>32||Chanell<1)return INVALIDCHANELL;

TimeOutValue=TimeOut;

CurrentChanell=(unsigned char)Chanell;

//init winsock2
memset(&wsaData,0,sizeof(WSADATA));

wsaVersion=MAKEWORD(2,0);
if(WSAStartup(wsaVersion,&wsaData)!=0)return WSA2STARTUP;

//init vars

//own ip

HostName=(char*)malloc(128);

gethostname(HostName,120);

HostData = new (struct hostent);

HostData=gethostbyname(HostName);

OwnIp=(char*)malloc(4);

memcpy(OwnIp,HostData->h_addr_list[0],4);

//creating sockets

SenderSock=socket(AF_INET,SOCK_DGRAM,0);
RecieverSock=socket(AF_INET,SOCK_DGRAM,0);

if(INVALID_SOCKET==SenderSock||INVALID_SOCKET==RecieverSock)return SOCKETSERROR;

GroupIP = (char*) malloc (14);

sprintf(GroupIP,"224.0.5.%d",Chanell);


bool v=true;

setsockopt(RecieverSock,SOL_SOCKET,SO_REUSEADDR,(char*)&v,sizeof(v));

memset(&SendStruct,0,sizeof(struct sockaddr_in));
memset(&sendbind,0,sizeof(struct sockaddr_in));
memset(&recievebind,0,sizeof(struct sockaddr_in));

//prepare stuct used for sends

SendStruct.sin_addr.s_addr=inet_addr(GroupIP);
SendStruct.sin_family=AF_INET;
SendStruct.sin_port=htons(DataPort);

//bind

sendbind.sin_addr.s_addr=inet_addr(INADDR_ANY);
recievebind.sin_addr.s_addr=inet_addr(GroupIP);//htonl(INADDR_ANY);
sendbind.sin_family=AF_INET;
recievebind.sin_family=AF_INET;
sendbind.sin_port=htons(DataPort);
recievebind.sin_port=htons(DataPort);

// if(bind(SenderSock,(struct sockaddr*)&sendbind,sizeof(struct sockaddr_in))==SOCKET_ERROR)return BINDERROR;
if(bind(RecieverSock,(struct sockaddr*)&recievebind,sizeof(struct sockaddr_in))==SOCKET_ERROR)return BINDERROR;

//multicast

memset(&MulticastReq,0,sizeof(MulticastReq));

MulticastReq.imr_multiaddr.s_addr=inet_addr(GroupIP);
MulticastReq.imr_interface.s_addr=htonl(INADDR_ANY);

//setsockopt

if(setsockopt(RecieverSock,IPPROTO_IP,IP_ADD_MEMBERSHIP,(char*)&MulticastReq,sizeof(MulticastReq))==SOCKET_ERROR)return MULTICAST;
// if(setsockopt(SenderSock,IPPROTO_IP,IP_ADD_MEMBERSHIP,(char*)&MulticastReq,sizeof(MulticastReq))==SOCKET_ERROR)return MULTICAST;

u_char loop = false;

if(setsockopt(RecieverSock,IPPROTO_IP,IP_MULTICAST_LOOP,(char*)&loop,sizeof(loop))==SOCKET_ERROR)return MULTICAST;
// if(setsockopt(SenderSock,IPPROTO_IP,IP_MULTICAST_LOOP,(char*)&loop,sizeof(loop))==SOCKET_ERROR)return MULTICAST;



//create recieve thread

if(NULL==CreateThread(NULL,0,RecieveThread,NULL,0,NULL))return THREADERROR;

//yooooo.... global init

Message=(char*)malloc(DATASIZE);

UserCount=0;

Initialized=true;
return SUCCESS;