computernetwork.rar_UDP组播

// 接收方程序 receivers.c //#include <windows.h> #include <winsock2.h> #include <ws2tcpip.h> #include <stdio.h> #define BUFFSIZE 2048 #define RECV_IP_ADDR "224.8.8.1 " #define DEST_PORT 8000 int main(int argc,char *argv[]) { int sockfd; int sock_reuse=1; struct ip_mreq multicast; struct sockaddr_in recver_addr; char szError[100]; int index=0, iRecvLen; // Length of recv_sin char szMessageA[1024*320]; // ASCII string //TCHAR szMessageW[1024*320]; // Unicode string char szMessageW[1024*320]; //启动SOCKET环境 WSADATA WSAData; WORD wVersionRequested; wVersionRequested=MAKEWORD(1,1); if(WSAStartup(wVersionRequested,&WSAData)!=0) { printf( "recver:Initialize Winsock error! "); exit(1); } if(LOBYTE(WSAData.wVersion)!=1||HIBYTE(WSAData.wVersion)!=1) { WSACleanup(); printf("setsockopt failed! Error: %d ",WSAGetLastError()); exit(1); } multicast.imr_multiaddr.s_addr=inet_addr(RECV_IP_ADDR); //宏RECV_IP_ADDR "224.8.8.1 " multicast.imr_interface.s_addr=htonl(INADDR_ANY); recver_addr.sin_family=AF_INET; recver_addr.sin_port=htons(DEST_PORT); recver_addr.sin_addr.s_addr=INADDR_ANY; sockfd=socket(AF_INET,SOCK_DGRAM,0); //if((sockfd=socket(AF_INET,SOCK_DGRAM,0))<0) //{ // printf( "recver:new a socket error!\n "); // exit(1); //} setsockopt(sockfd,SOL_SOCKET,SO_REUSEADDR,(char*)&sock_reuse,sizeof(sock_reuse)); //if(setsockopt(sockfd,SOL_SOCKET,SO_REUSEADDR,(char*)&sock_reuse,sizeof(sock_reuse))<0) // { // printf( "recver:socket options set error "); // exit(1); // } bind(sockfd,(struct sockaddr *)&recver_addr,sizeof(recver_addr)); //if(bind(sockfd,(struct sockaddr *)&recver_addr,sizeof(recver_addr))<0) // { // closesocket(sockfd); // printf( "recver:bind socket error!\n "); // exit(1); //} setsockopt(sockfd,IPPROTO_IP,IP_ADD_MEMBERSHIP,(char*)&multicast,sizeof(multicast)); //if(setsockopt(sockfd,IPPROTO_IP,IP_ADD_MEMBERSHIP,(char*)&multicast,sizeof(multicast))<0) // { // sprintf(szError,TEXT( "setsockopt failed! Error:%d "),WSAGetLastError()); // printf( "%s\n ",szError); // closesocket(sockfd); // exit(1); // } printf( "这里是接收方：Receive on %s:%d\n ",RECV_IP_ADDR,DEST_PORT); iRecvLen=sizeof(recver_addr); memset(szMessageA,0,sizeof(szMessageA)); //Receive data from the multicasting group server. if(recvfrom(sockfd,szMessageA,sizeof(szMessageA),0,(struct sockaddr FAR *)&recver_addr,&iRecvLen) ==SOCKET_ERROR) { sprintf(szError,TEXT( "recvfrom failed!Error: %d "),WSAGetLastError()); //wsprintf MessageBox(NULL,szError,TEXT( "Error "),MB_OK); //printf("%s",szError); closesocket(sockfd); return FALSE; } else { for(index=0;index<=sizeof(szMessageA);index++) szMessageW[index]=szMessageA[index]; printf("收到组播数据%s",szMessageW); //MessageBox(NULL,szMessageW,TEXT( "Info "),MB_OK); } //Disable receiving on Sock before closing it. shutdown(sockfd,0x00); //CloseSock. closesocket(sockfd); WSACleanup(); while(1); return 0; }