view/SocketX/Network.cpp

#pragma once

#include "stdafx.h"
#include "SocketX.h"

//////////////////////////////////////////////////////////////////////////

CNetwork::CNetwork()
{
}

CNetwork::~CNetwork()
{
}

BOOL CNetwork::GetIPv4List(DWORD &dwSize, DWORD dwMax, LPIPv4 lpList)
{
        PMIB_IPADDRTABLE pIpAddrTable;
        DWORD dwTbSize = 0;
        DWORD dwRetVal = 0;

        // Get size
        if (GetIpAddrTable(NULL, &dwTbSize, 0) == ERROR_INSUFFICIENT_BUFFER)
        {
                pIpAddrTable = (PMIB_IPADDRTABLE)malloc(dwTbSize);

                if (pIpAddrTable == NULL)
                {
                        TRACE1("***** ERROR: malloc(%d) *****\n", GetLastError());
                        return FALSE;
                }
        }

        // Get data
        if (GetIpAddrTable(pIpAddrTable, &dwTbSize, 0) == NO_ERROR)
        {
                if (pIpAddrTable->dwNumEntries > 0)
                {
                        dwSize = pIpAddrTable->dwNumEntries < dwMax ?
                                         pIpAddrTable->dwNumEntries : dwMax;

                        for (UINT i = 0; i < (UINT)dwSize; i++)
                        {
                                lpList[i].dwIndex                = pIpAddrTable->table[i].dwIndex;
                                lpList[i].dwAddress          = pIpAddrTable->table[i].dwAddr;
                                lpList[i].dwNetMask      = pIpAddrTable->table[i].dwMask;
                                lpList[i].dwBcastAddress = MakeBcastAddress(lpList[i].dwAddress, lpList[i].dwNetMask);
                        }
                }
        }

        free(pIpAddrTable);

        return TRUE;
}

BOOL CNetwork::IsAvailable()
{
        DWORD dwSize;
        IPv4  list[2];

        if (!GetIPv4List(dwSize, 2, list))
        {
                return FALSE;
        }

        // Is not connected to the network. Or just loopback
        if ((dwSize < 1) || (dwSize == 1 && list[0].dwAddress == 0x0100007F))
        {
                return FALSE;
        }

        return TRUE;
}

DWORD CNetwork::MakeBcastAddress(DWORD dwAddress, DWORD dwNetMask)
{
        return ((dwAddress & dwNetMask) | (~dwNetMask));
}

//////////////////////////////////////////////////////////////////////////