ping.cpp

VC编写的一个非常好的 可以用于pin局域网的电脑的程序!!并且是基于线程的!有兴趣的可以研究一下!

#include "stdafx.h"
#include "ping.h"


void CPing::Ping(UINT nRetries,LPCSTR pstrHost,HWND hWnd)
{
	SOCKET	  rawSocket;
	LPHOSTENT lpHost;
	UINT	  nLoop;
	int       nRet;
	struct    sockaddr_in saDest;
	struct    sockaddr_in saSrc;
	DWORD	  dwTimeSent;
	DWORD	  dwElapsed;
	u_char    cTTL;


	m_hWnd = hWnd;

	CString str;

	ASSERT(IsWindow(hWnd));

	//创建一个Raw套节字
	rawSocket = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
	if (rawSocket == SOCKET_ERROR) 
	{
		WSAError("socket()");
		return;
	}
	
	//获得主机信息
	lpHost = gethostbyname(pstrHost);
	if (lpHost == NULL)
	{
		str.Format("Host not found: %s", pstrHost);
		::PostMessage(m_hWnd,WM_MSG_STATUS, 0, (LPARAM) AllocBuffer(str));
		::PostMessage(m_hWnd,WM_PING_END, 0, 0);
		return;
	}
	
	//构造目标套节字地址信息
	saDest.sin_addr.s_addr = *((u_long FAR *) (lpHost->h_addr));
	saDest.sin_family = AF_INET;
	saDest.sin_port = 0;

	//告诉用户我们现在的工作
	str.Format("Pinging %s [%s] with %d bytes of data:",
				pstrHost,
				inet_ntoa(saDest.sin_addr),
				REQ_DATASIZE);
	::PostMessage(m_hWnd,WM_MSG_STATUS, 1, (LPARAM) AllocBuffer(str));

	//多次ping
	for (nLoop = 0; nLoop < nRetries; nLoop++)
	{
		//发送ICMP回应请求
		SendEchoRequest(rawSocket, &saDest);

		nRet = WaitForEchoReply(rawSocket);
		if (nRet == SOCKET_ERROR)
		{
			WSAError("select()");
			break;
		}
		if (!nRet)
		{
			str.Format("Request Timed Out");
			::PostMessage(m_hWnd,WM_MSG_STATUS, 3, (LPARAM) AllocBuffer(str));
		}
		else

		{
			//获得回应
			dwTimeSent = RecvEchoReply(rawSocket, &saSrc, &cTTL);

			//计算时间
			dwElapsed = GetTickCount() - dwTimeSent;
			str.Format("Reply[%d] from: %s: bytes=%d time=%ldms TTL=%d", 
				nLoop+1,
				   inet_ntoa(saSrc.sin_addr), 
				   REQ_DATASIZE,
				   dwElapsed,
				   cTTL);

			::PostMessage(m_hWnd,WM_MSG_STATUS, 2, (LPARAM) AllocBuffer(str));

			Sleep(1000);
		}
	}
	
	::PostMessage(m_hWnd,WM_PING_END, 0, 1);

	nRet = closesocket(rawSocket);
	if (nRet == SOCKET_ERROR)
		WSAError("closesocket()");

}

//发送ICMPECHO数据包请求
int CPing::SendEchoRequest(SOCKET s,LPSOCKADDR_IN lpstToAddr) 
{
	static ECHOREQUEST echoReq;
	static nId = 1;
	static nSeq = 1;
	int nRet;

	//构造回应请求
	echoReq.icmpHdr.Type		= ICMP_ECHOREQ;
	echoReq.icmpHdr.Code		= 0;
	echoReq.icmpHdr.Checksum	= 0;
	echoReq.icmpHdr.ID			= nId++;
	echoReq.icmpHdr.Seq			= nSeq++;

	for (nRet = 0; nRet < REQ_DATASIZE; nRet++)
		echoReq.cData[nRet] = ' '+nRet;

	//保存发送时间
	echoReq.dwTime				= GetTickCount();

	echoReq.icmpHdr.Checksum = in_cksum((u_short *)&echoReq, sizeof(ECHOREQUEST));

	//发送请求
	nRet = sendto(s,						
				 (LPSTR)&echoReq,			
				 sizeof(ECHOREQUEST),
				 0,							
				 (LPSOCKADDR)lpstToAddr, 
				 sizeof(SOCKADDR_IN));   

	if (nRet == SOCKET_ERROR) 
		WSAError("sendto()");
	return (nRet);
}

//接收ICMPECHO数据包回应
DWORD CPing::RecvEchoReply(SOCKET s, LPSOCKADDR_IN lpsaFrom, u_char *pTTL) 
{
	ECHOREPLY echoReply;
	int nRet;
	int nAddrLen = sizeof(struct sockaddr_in);

	//接收请求回应
	nRet = recvfrom(s,					
					(LPSTR)&echoReply,	
					sizeof(ECHOREPLY),	
					0,					
					(LPSOCKADDR)lpsaFrom,
					&nAddrLen);			

	//检查返回值
	if (nRet == SOCKET_ERROR) 
		WSAError("recvfrom()");

	//返回发送的时间
	*pTTL = echoReply.ipHdr.TTL;

	return(echoReply.echoRequest.dwTime);   		
}

//等待回应
int CPing::WaitForEchoReply(SOCKET s)
{
	struct timeval Timeout;
	fd_set readfds;

	readfds.fd_count = 1;
	readfds.fd_array[0] = s;
	Timeout.tv_sec = 1;
    Timeout.tv_usec = 0;

	return(select(1, &readfds, NULL, NULL, &Timeout));
}

//错误处理
void CPing::WSAError(LPCSTR lpMsg)
{
	CString strMsg;
	strMsg.Format("%s - WSAError: %ld",lpMsg,WSAGetLastError());	
	//发送报错信息
	::PostMessage(m_hWnd,WM_MSG_STATUS, 0, (LPARAM) AllocBuffer(strMsg));
}

//转换地址
u_short CPing::in_cksum(u_short *addr, int len)
{
	register int nleft = len;
	register u_short *w = addr;
	register u_short answer;
	register int sum = 0;

	while( nleft > 1 )  {
		sum += *w++;
		nleft -= 2;
	}

	if( nleft == 1 ) {
		u_short	u = 0;

		*(u_char *)(&u) = *(u_char *)w ;
		sum += u;
	}

	sum = (sum >> 16) + (sum & 0xffff);	
	sum += (sum >> 16);			
	answer = ~sum;				
	return (answer);
}