Problem with Winpkfilter

Please note that all the problems are seen only in costumer place. Please point out the possible causes for this kind of issues. It’s quite urgent as we are not able to trace the root cause yet.

I don’t know if this makes any sense, this is the code we have added to Internet Gateway,so that we can allow users based on their MAC address.

if(::SendARP(pIpHeader->ip_src.S_un.S_addr, INADDR_ANY, MACSource, &dwMacSize) != NO_ERROR)
continue;

pNatClient = pDlg->GetClientByMAC(MACSource);
if(pNatClient == NULL)
if(!hAdapters[dwIndex]->IsLocalAddress(&pIpHeader->ip_dst))
{
if(pIpHeader->ip_p == IPPROTO_TCP)
{
pTcpHeader = (tcphdr*)(((PUCHAR)pIpHeader) + sizeof(DWORD)*pIpHeader->ip_hl);
if(ntohs(pTcpHeader->th_dport) != 80)
{
if(ntohs(pTcpHeader->th_dport) != 443)
{

continue;

}

}

if(pTcpHeader->th_flags == TH_SYN)
bTrack = TRUE;
}
}
}

if((bForceRouting) &&(hAdapters[dwIndex]->m_NATState == CLIENT) && (PacketBuffer.m_dwDeviceFlags == PACKET_FLAG_ON_RECEIVE))
{
bNeedToBeRouted = pDlg->IsNeedToForceRouting(pEthHeader->h_dest, pIpHeader->ip_dst.S_un.S_addr, pProviderCard->m_Index);
}

// TCP packet processing
if (pIpHeader->ip_p == IPPROTO_TCP)
{
// This is TCP packet, get TCP header pointer
pTcpHeader = (tcphdr*)(((PUCHAR)pIpHeader) + sizeof(DWORD)*pIpHeader->ip_hl);

// Outgoing TCP packets processing
if(((bForceRouting) && (bNeedToBeRouted) &&(hAdapters[dwIndex]->m_NATState == CLIENT)&&(PacketBuffer.m_dwDeviceFlags == PACKET_FLAG_ON_RECEIVE))
||
((!bForceRouting) &&(hAdapters[dwIndex]->m_NATState == PROVIDER)&&(PacketBuffer.m_dwDeviceFlags == PACKET_FLAG_ON_SEND)))
{
CPortNATEntry* pTcpNE = NULL;

if (pTcpHeader->th_flags == TH_SYN)
{
// New TCP connnection established, allocate dynamic NAT entry

if((!bForceRouting) && bTrack)
pTcpNE = pDlg->m_TcpNatTable.Allocate(pIpHeader->ip_src, pTcpHeader->th_sport, pIpHeader->ip_dst, pTcpHeader->th_dport, bTrack, MACSource);
else if(bForceRouting && bTrack)
pTcpNE = pDlg->m_TcpNatTable.Allocate(pIpHeader->ip_src, pTcpHeader->th_sport, pIpHeader->ip_dst, pTcpHeader->th_dport, bTrack, pEthHeader->h_source);
else
pTcpNE = pDlg->m_TcpNatTable.Allocate(pIpHeader->ip_src, pTcpHeader->th_sport, pIpHeader->ip_dst, pTcpHeader->th_dport, bTrack);

if(pTcpNE)
{
pTcpNE->m_IpNAT = bForceRouting?pProviderCard->m_NATIp:hAdapters[dwIndex]->m_NATIp;
}

pDlg->CheckMTUCorrelation(&PacketBuffer, pIpHeader, pTcpHeader);
}
else
{
// Try to locate existing NAT entry
pTcpNE = pDlg->m_TcpNatTable.Find(pIpHeader->ip_src, pTcpHeader->th_sport, pIpHeader->ip_dst, pTcpHeader->th_dport);

if(pTcpNE && pTcpNE->m_bTracked && pTcpHeader->th_flags == (TH_ACK | TH_PSH))
{
// Add filtering URL here
CHAR * pHttpMsg = (CHAR*)(((PUCHAR)pTcpHeader) + sizeof(DWORD)*pTcpHeader->th_off);
INT maxLength = PacketBuffer.m_Length – ::abs((LONG)((DWORD)pHttpMsg – (DWORD)pEthHeader));
CHAR* szHost = NULL;
CHAR *pHttpHeaderLine = new char[1024];
int i = 0, j;

::ZeroMemory(pHttpHeaderLine, 1024);

do{
j = 0;
while( i < maxLength && pHttpMsg != ‘n’ && j < 1022)
{
pHttpHeaderLine[j] = pHttpMsg;
i++;
j++;
}
pHttpHeaderLine[j++] = ‘n’;
pHttpHeaderLine[j] = ‘’;
i++;

if(szHost != NULL)
delete szHost;
}
}