C++实现ping程序实例

本文实例讲述了C++实现ping程序的方法。分享给大家供大家参考。具体实现方法如下：

该实例涉及ICMP数据包的发送与回显，PING程序代码如下：

DWORD WINAPI ThreadProc(LPVOID lParam)

{

 CInitSock initSock;

 

 HWND hWnd = (HWND)lParam; //从参数得到句柄

 char szIp[64] ={0}; 

 ::GetDlgItemTextA(hWnd, IDC_IP, szIp, sizeof(szIp)); //从控件得到ip地址

 //1. 创建协议类型为IPPROTO_ICMP的原始套接字，设置套接字属性

 SOCKET sRaw = ::socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);

 SetTimeOut(sRaw, 1000, TRUE);

 //2.创建并初始化ICMP封包

 char buff[sizeof(ICMP_HDR)+32] = {0};

 ICMP_HDR* pIcmp = (ICMP_HDR*)buff;

 pIcmp->icmp_type = 8;

 pIcmp->icmp_code = 0;

 pIcmp->icmp_checksum = 0;

 pIcmp->icmp_id = (USHORT)::GetCurrentProcessId();

 pIcmp->icmp_sequence = 0;

 pIcmp->icmp_timestamp = 0;

 //填充数据

 memset(&buff[sizeof(ICMP_HDR)], 'E', 32);
 //开始发送和接收封包

 USHORT nSeq = 0;

 SOCKADDR_IN dest;

 dest.sin_family = AF_INET;

 dest.sin_port = htons(0);

 dest.sin_addr.S_un.S_addr = inet_addr(szIp); //inet_addr("192.168.19.63"); //inet_addr(szIp);220.181.111.147

 CString strToShow="";

 char* pszRevBuf = new char[1024]; //[1024] = {0};

 memset(pszRevBuf, 0, 1024);

 SOCKADDR_IN from;

 int nFromLen= sizeof(from);

 while (TRUE)

 {

  //3. 调用sendto发送ICMP请求

  static int nCount=0;

  if (nCount++==4)

  {

   break;

  }

  pIcmp->icmp_checksum = checksum((USHORT*)buff, sizeof(ICMP_HDR)+32);

  pIcmp->icmp_sequence = ++nSeq;

  pIcmp->icmp_timestamp = ::GetTickCount();

  int nRet;

  nRet = ::sendto(sRaw, buff, sizeof(ICMP_HDR)+32, 0, (SOCKADDR*)&dest, sizeof(dest));

  if (nRet == SOCKET_ERROR)

  {

   int nError = ::WSAGetLastError();

   strToShow += "sendto error\r\n";

   return -1;

  }

  

  //4. 调用recvfrom接受ICMP响应

  nRet = ::recvfrom(sRaw, pszRevBuf, 1024, 0, (sockaddr*)&from, &nFromLen);

  if (nRet == SOCKET_ERROR)

  {

   if (::WSAGetLastError() == WSAETIMEDOUT)

   {

    strToShow += "timeout\r\n";

    continue;

   }

   strToShow += "recvfrom error\r\n";

   return -1;

  }

  //解析接收到的ICMP包

  int nTick = ::GetTickCount();

  if (nRet < sizeof(ICMP_HDR)+sizeof(IPHeader))

  {

   strToShow += "less byte recved..\r\n";

  }

  ICMP_HDR* pRecvIcmp = (ICMP_HDR*)(pszRevBuf + sizeof(IPHeader));// 跳过IP头

  if (pRecvIcmp->icmp_type != 0)

  {

   strToShow += "不是回显类型";

   return -1;

  }

  if (pRecvIcmp->icmp_id != ::GetCurrentProcessId())

  {

   strToShow += "不是本进程的回显包\r\n";

   return -1;

  }

  CString strTemp;

  strTemp.Format("收到来自于[%s]IP的%04d字节\r\n", inet_ntoa(from.sin_addr), nRet);

  strToShow += strTemp;
  strTemp = "";

  strTemp.Format("序列号:%d\r\n", pRecvIcmp->icmp_sequence);

  strToShow += strTemp;
  strTemp = "";

  strTemp.Format("花费时间:%d\r\n", nTick - pRecvIcmp->icmp_timestamp);

 }

 strToShow += "**********************************";

 ::SetDlgItemTextA(hWnd, IDC_DATA, strToShow);

 return 0;

}

IP头和ICMP头代码如下：

USHORT checksum(USHORT* buff, int nSize) //222.89.166.13

{

 unsigned long cksum=0;

 //将数据以字为单位加到cksum

 while (nSize > 1)

 {

  cksum += *buff++;

  nSize -= sizeof(USHORT);

 }

 //如果为奇数, 将最后一个字扩展到双字，再累加

 if (nSize)

 {

  cksum += *(UCHAR*)buff;

 }

 //将cksum的高16位与低16位相加，取反后得到校验和

 cksum = (cksum>>16) + (cksum & 0xffff);

 cksum += (cksum>>16);

 return (USHORT)(~cksum);

}

BOOL SetTimeOut(SOCKET s, int nTime, BOOL bRecv)

{

 int ret = ::setsockopt(s, SOL_SOCKET, bRecv?SO_RCVTIMEO:SO_SNDTIMEO, (char*)&nTime, sizeof(nTime));

 return ret!=SOCKET_ERROR;

}

typedef struct icmp_hdr

{

 unsigned char icmp_type;

 unsigned char icmp_code;

 unsigned short icmp_checksum;

 //下面是回显头

 unsigned short icmp_id;

 unsigned short icmp_sequence;

 unsigned long icmp_timestamp;

}ICMP_HDR, *PICMP_HDR;
typedef struct _IPHeader

{

 UCHAR iphVerLen;

 UCHAR ipTOS;

 USHORT ipLength;

 USHORT ipID;

 USHORT ipFlag;

 UCHAR ipTTL;

 UCHAR ipProtocol;

 USHORT ipCheckSum;

 ULONG ipSource;

 ULONG ipDestination;

}IPHeader, *PIPHeader;

希望本文所述对大家的C++程序设计有所帮助。