C++实现Ping

int CPing::SendEchoRequest(SOCKET s,LPSOCKADDR_IN lpstToAddr) { static ECHOREQUEST echoReq; static nId = 1; static nSeq = 1; int nRet; // Fill in echo request echoReq.icmpHdr.Type = ICMP_ECHOREQ; echoReq.icmpHdr.Code = 0; echoReq.icmpHdr.Checksum = 0; echoReq.icmpHdr.ID = nId++; echoReq.icmpHdr.Seq = nSeq++; // Fill in some data to send for (nRet = 0; nRet < REQ_DATASIZE; nRet++) echoReq.cData[nRet] = ' '+nRet; // Save tick count when sent echoReq.dwTime = GetTickCount(); // Put data in packet and compute checksum echoReq.icmpHdr.Checksum = in_cksum((u_short *)&echoReq;, sizeof(ECHOREQUEST)); // Send the echo request nRet = sendto(s, /* socket */ (LPSTR)&echoReq;, /* buffer */ sizeof(ECHOREQUEST), 0, /* flags */ (LPSOCKADDR)lpstToAddr, /* destination */ sizeof(SOCKADDR_IN)); /* address length */ if (nRet == SOCKET_ERROR) WSAError("sendto()"); return (nRet); }