1123 检查主机在线的代码

最新推荐文章于 2024-06-07 22:07:27 发布

转载最新推荐文章于 2024-06-07 22:07:27 发布 · 419 阅读

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本文介绍了一个使用ICMP协议检查远程主机状态的C++实现。通过创建原始套接字并发送ICMP请求，该函数能够判断目标IP地址是否可达。文章详细展示了初始化网络环境、构建ICMP数据包、设置超时时间以及接收响应的过程。

BOOL CheckHostStatus(CString &strIPAddr)
{
char destip[20] ;
sprintf(destip,"%s",strIPAddr.GetBuffer(strIPAddr.GetLength()));

//定义变量
SOCKET           m_hSocket;
SOCKADDR_IN      m_addrDest;
SOCKADDR_IN      m_addrFrom;
char             *icmp_data;
    char             *recvbuf;
USHORT           seq_no ;
char             *lpdest;
int              datasize;
BOOL    m_bRecordRout;
int              timeout;
    int              recvicmpnum;
int     ret = 0;

//初始化变量
icmp_data     = NULL;
seq_no        = 0;
recvbuf       = NULL;
m_bRecordRout = FALSE;
lpdest        = NULL;
datasize      = DEF_PACKET_SIZE;
m_hSocket     = INVALID_SOCKET;
    recvicmpnum   = 0;

//初始化套接字
WSADATA wsaData;
if (WSAStartup(MAKEWORD(2, 2), &wsaData) != 0)
    {
        return 0;
    }

m_bRecordRout = FALSE;
lpdest = destip;

m_hSocket = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);

    if (m_hSocket == INVALID_SOCKET)
    {
        return FALSE ;
    }

timeout = 100;
ret = setsockopt(m_hSocket, SOL_SOCKET, SO_RCVTIMEO,
(char*)&timeout, sizeof(timeout));

    if(ret == SOCKET_ERROR)
    {
  if (m_hSocket != INVALID_SOCKET) {
   closesocket(m_hSocket);
  }
        return FALSE;
    }

    ret = setsockopt(m_hSocket, SOL_SOCKET, SO_SNDTIMEO,
                (char*)&timeout, sizeof(timeout));

    if (ret == SOCKET_ERROR)
    {
  if (m_hSocket != INVALID_SOCKET) {
   closesocket(m_hSocket);
  }
        return FALSE;
    }

memset(&m_addrDest, 0, sizeof(m_addrDest));

m_addrDest.sin_family = AF_INET;

if ((m_addrDest.sin_addr.s_addr = inet_addr(lpdest)) == INADDR_NONE)
    {
  if (m_hSocket != INVALID_SOCKET) {
   closesocket(m_hSocket);
  }
        return FALSE;
    }

    //
    // Create the ICMP packet
    //
    datasize += sizeof(IcmpHeader);

    icmp_data =(char*) HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY,MAX_PACKET);
    if (!icmp_data)
    {
  if (m_hSocket != INVALID_SOCKET) {
   closesocket(m_hSocket);
  }
        return FALSE;
    }

    recvbuf   =(char*) HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY,MAX_PACKET);
    if (!recvbuf)
    {
  if (m_hSocket != INVALID_SOCKET) {
   closesocket(m_hSocket);
  }
        return FALSE;
    }

memset(icmp_data,0,MAX_PACKET);

//重要函数，填充ICMP包头
FillICMPData(icmp_data,datasize);

    ((IcmpHeader*)icmp_data)->i_cksum = 0;
    ((IcmpHeader*)icmp_data)->timestamp = GetTickCount();
    ((IcmpHeader*)icmp_data)->i_seq = seq_no++;
    ((IcmpHeader*)icmp_data)->i_cksum = CheckSum((USHORT*)icmp_data, datasize);

DWORD time=GetTickCount();
    ret = sendto(m_hSocket, icmp_data, datasize, 0,
                     (struct sockaddr*)&m_addrDest, sizeof(m_addrDest));

    if (ret == SOCKET_ERROR)
    {
  if (m_hSocket != INVALID_SOCKET) {
   closesocket(m_hSocket);
  }
  HeapFree(GetProcessHeap(), 0, recvbuf );
  HeapFree(GetProcessHeap(), 0, icmp_data);
  WSACleanup();

return FALSE;
}

int fromlen = sizeof(m_addrFrom);
    time= GetTickCount();
ret = recvfrom(m_hSocket, recvbuf, MAX_PACKET, 0,
                (struct sockaddr*)&m_addrFrom, &fromlen);

if (ret == SOCKET_ERROR)
    {
  if (m_hSocket != INVALID_SOCKET) {
   closesocket(m_hSocket);
  }
  HeapFree(GetProcessHeap(), 0, recvbuf );
  HeapFree(GetProcessHeap(), 0, icmp_data);
  WSACleanup();

return FALSE;
}

if (m_hSocket != INVALID_SOCKET) {
        closesocket(m_hSocket);
}
    HeapFree(GetProcessHeap(), 0, recvbuf );
    HeapFree(GetProcessHeap(), 0, icmp_data);

return TRUE;
}