#pragma once
#include "StdAfx.h"

#include "MyPingip.h"  
//#include <iphlpapi.h>
//#pragma comment (lib , "Iphlpapi.lib")
#pragma comment (lib , "wsock32.lib")

#pragma warning(disable : 4996)

#define  WM_MSG_STATUS     WM_USER + 100

CMyPingip::CMyPingip(void)
{
}


CMyPingip::~CMyPingip(void)
{
}


bool CMyPingip::PingFunction(LPCSTR pstrHost/*, Logger *pLog*/)
{
	int nRetries = 5;
	int nLostConnectCnt = 0;
	bool bRet = true;

	WSADATA wsaData;
	WORD wVersionRequested;
	wVersionRequested = MAKEWORD( 2, 0 );

	if(WSAStartup(wVersionRequested ,&wsaData) != 0)
	{
		return false;
	}
	SOCKET    rawSocket;  
	int       nLoop;
	int       nRet;  
	struct    sockaddr_in saDest;  
	struct    sockaddr_in saSrc;  
	DWORD     dwTimeSent;  
	DWORD     dwElapsed;  
	u_char    cTTL;  

	//创建一个Raw套接字  
	rawSocket = socket(AF_INET,SOCK_RAW,IPPROTO_ICMP);  
	if (rawSocket == SOCKET_ERROR)  
	{  
		//PRINTA_INFO(pLog, "Create Socket Error – WSAError: %ld", WSAGetLastError());
		return false;  
	}  

	//获得主机信息  
	//lpHost = gethostbyname(pstrHost);  
	//构造目标套接字地址信息  
	saDest.sin_addr.s_addr = inet_addr(pstrHost)/**((u_long FAR *)(lpHost->h_addr))*/;
	saDest.sin_family = AF_INET;  
	saDest.sin_port = 0;  
	//ping  
	for (nLoop = 0; nLoop < nRetries; nLoop++)  
	{  
		//发送ICMP回应请求  
		SendEchoRequest(rawSocket, &saDest);  
		nRet = WaitForEchoReply(rawSocket);  

		if (!nRet)  //没有回应，不再一个IP段
		{  
			//PRINTA_INFO(pLog, "Request Timed Out");
			nLostConnectCnt++;
		}
		else  //在一个IP段，回应正确或者回应不可达
		{  
			dwTimeSent = RecvEchoReply(rawSocket,&saSrc,&cTTL); //获得回应 
			LPCSTR strIp = inet_ntoa(saSrc.sin_addr);
			if (strcmp(strIp,pstrHost)==0 )
			{
				dwElapsed = GetTickCount()-dwTimeSent;	//计算时间 
				//PRINTA_INFO(pLog, "Reply from: %s: bytes=%d time=%d ms TTL=%d", strIp, REQ_DATASIZE, dwElapsed, cTTL);
			}
			else
			{
				nLostConnectCnt++;
				//PRINTA_INFO(pLog, "Reply from: %s: Destination host unreachable", strIp);
			}
		}  
	}  

	nRet = closesocket(rawSocket);  
	if (nRet == SOCKET_ERROR)  
	{  
		//PRINTA_INFO(pLog, "Close Socket Error – WSAError: %ld", WSAGetLastError());
	}  
	WSACleanup();

	if (nLostConnectCnt>=3)
	{
		bRet = false;
	}
	return bRet;
}


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

	//构造回应请求  
	echo.icmpHdr.Type = 8;  
	echo.icmpHdr.Code = 0;  
	echo.icmpHdr.Checksum = 0;  
	echo.icmpHdr.ID = nId++;  
	echo.icmpHdr.Seq = nSeq++;  

	for (nRet = 0; nRet < REQ_DATASIZE; nRet++)
	{
		echo.cData[nRet] = ' ' + nRet;
	}

	//保存发送时间  
	echo.dwTime = GetTickCount();  
	echo.icmpHdr.Checksum = in_cksum((u_short *)&echo,sizeof(ECHOREQUEST));  

	//发送请求  
	nRet = sendto(s, (LPSTR)&echo, sizeof(ECHOREQUEST), 0, (LPSOCKADDR)lpstToAddr, sizeof(SOCKADDR_IN));
	if (nRet == SOCKET_ERROR)  
	{  
		//CString strMsg;  
		//strMsg.Format("发送数据时发生错误 – WSAError: %ld",WSAGetLastError());  

		//发送报错信息  
		//SendMessage(m_hWnd,WM_MSG_STATUS,0,(LPARAM) AllocBuffer(strMsg));  
	}  
	return (nRet);  
}  


//接收ICMPECHO数据包回应  
DWORD CMyPingip::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)  
	{  
		//CString strMsg;  
		//strMsg.Format("接收数据时发生错误 – WSAError: %ld",WSAGetLastError());  

		//发送报错信息  
		//SendMessage(m_hWnd,WM_MSG_STATUS,0,(LPARAM) AllocBuffer(strMsg));  
	}  

	//返回发送的时间  
	*pTTL = echoReply.iphdr.TTL;  
	return(echoReply.echorequest.dwTime);  
}  


//等待回应  
int CMyPingip::WaitForEchoReply(SOCKET s)  
{  
	struct timeval Time;  
	fd_set fds;  
	fds.fd_count = 1;  
	fds.fd_array[0] = s;  
	Time.tv_sec = 1;  
	Time.tv_usec = 0;  
	return(select(1,&fds,NULL,NULL,&Time));  
}  


//转换地址  
u_short CMyPingip::in_cksum(u_short *addr,int len)  
{  
	int nleft = len;  
	u_short *n = addr;  
	u_short answer;  
	int sum = 0;  
	while(nleft > 1)  
	{  
		sum += *n++;  
		nleft -= 2;  
	}  

	if(nleft == 1)  
	{  
		u_short u = 0;  
		*(u_char *)(&u) = *(u_char *)n;  
		sum += u;  
	}  

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