WinpkFilter wwwcensor in Delphi problem

[cristighenea]

Hi.
I am trying to implement the wwwcensor example in Delphi 2007, windows application.
I have a problem with WaitForMultipleObjects: it returns all the time -1
Can someone help me?
The code is:

procedure TForm1.block;

begin

//block!



//Initialize NDISAPI

InitNDISAPI();



//Create driver object

hFilt := OpenFilterDriver('NDISRD');



//Check if driver is loaded

if IsDriverLoaded(hFilt) then

begin

Memo1.Lines.add('driver is loaded!');



//get pattern to upper case

pattern:=Edit1.Text;

pattern:=UpperCase(pattern);



// Get system installed network interfaces

GetTcpipBoundAdaptersInfo (hFilt, @AdList);



//just checking the numbers of network interfaces

showmessage(inttostr(Adlist.m_nAdapterCount));



// Initialize common ADAPTER_MODE structure (all network interfaces will operate in the same mode)

Mode.dwFlags := MSTCP_FLAG_SENT_TUNNEL xor MSTCP_FLAG_RECV_TUNNEL;



// Create notification events and initialize the driver to pass packets thru us

for dwAdIndex := 1 to AdList.m_nAdapterCount do

begin



Memo1.Lines.add('set adapter no '+inttostr(dwAdindex));

Memo1.Lines.add(AdList.m_szAdapterNameList[dwAdindex]);

showmessage('hhh');



hEvent[dwAdIndex] := CreateEvent(nil, TRUE, FALSE, nil);



// modify this for error

if hEvent[dwAdIndex] = 0 then begin showmessage('hEvent error');halt;end;



Mode.hAdapterHandle := AdList.m_nAdapterHandle[dwAdIndex];

// Set MSTCP_FLAG_SENT_TUNNEL|MSTCP_FLAG_RECV_TUNNEL for the network interface

SetAdapterMode ( hFilt, @Mode );



// Set packet notification event for the network interface

if SetPacketEvent(hFilt,AdList.m_nAdapterHandle[dwAdIndex], hEvent[dwAdIndex]) = 0 then begin showmessage('SetPacketEvent error');halt;end;

end;



// Initialize common part of ETH_REQUEST

ReadRequest.EthPacket.Buffer := @Buffer;





while true do

begin

Application.ProcessMessages;

// Wait before any of the interfaces is ready to indicate the packet

dwAdIndex := WaitForMultipleObjects ( AdList.m_nAdapterCount, @hEvent, FALSE, INFINITE ) -WAIT_OBJECT_0;

if dwAdIndex<>-1 then

begin

Memo1.Lines.Add('act on '+inttostr(dwAdIndex));

//dwAdIndex := WaitForSingleObject ( hEvent[1], INFINITE );

// Complete initialization of ETH_REQUEST

ReadRequest.hAdapterHandle := AdList.m_nAdapterHandle[dwAdIndex];



// Read packet from the interface until there are any

while ReadPacket (hFilt, @ReadRequest) <> 0 do

begin

Application.ProcessMessages;

// Get Ethernet header

pEthHeader := TEtherHeaderPtr (@Buffer.m_IBuffer);

if ntohs(pEthHeader.h_proto) = ETH_P_IP then

begin

// Get IP header

pIPHeader := TIPHeaderPtr(Integer(pEthHeader) + SizeOf(TEtherHeader));//1);//SizeOf(TEtherHeader));



// Check if IP packet contains TCP packet

if pIpHeader.Protocol = IPPROTO_TCP then

begin

// Get TCP header pointer

pTcpHeader  := TTCPHeaderPtr(Integer(pIPHeader) + (pIPHeader.VerLen and $F) * 4);



// Check if this HTTP packet is destined to remote system port 80, or received from it

if (((pTcpHeader.DestPort = htons (80))and(Buffer.m_dwDeviceFlags = PACKET_FLAG_ON_SEND))or

((pTcpHeader.SourcePort = htons (80))and(Buffer.m_dwDeviceFlags = PACKET_FLAG_ON_RECEIVE)))

then

begin



// Get data size in the packet and pointer to the data

dwDataLength := Buffer.m_Length - (sizeof(pEthHeader) + pIpHeader.VerLen*4 + pTcpHeader.Offset*4);

pData := pchar(pEthHeader) + (sizeof(pEthHeader) + pIpHeader.VerLen*4 + pTcpHeader.Offset*4);



// If packet contains any data - process it

if (dwDataLength>0) then

begin

Memo1.Lines.Add('something');

end;

end;





end;





end;







end

end;

end;





end

else

begin

Memo1.Lines.add('driver is not loaded!');

end;

end;

The variables are:

hFilt: THANDLE;

AdList: TCP_AdapterList;

Mode:ADAPTER_MODE;

hEvent: array[0..255] of THANDLE;

ReadRequest : ETH_REQUEST;

Buffer: INTERMEDIATE_BUFFER;

pEthHeader: TEtherHeaderPtr;

pIPHeader: TIPHeaderPtr;

pTcpHeader: TTCPHeaderPtr;

dwDataLength: word;

pData : pchar;

pattern: string;

dwAdIndex:integer;

What am I doing wrong? 🙁

Thanks

[Vadim Smirnov]

-1 means WAIT_FAILED and the problem is in hEvent[0] value which is NULL

You defined hEvent array indexed from 0, as below

hEvent: array[0..255] of THANDLE;

But you fill it with event handles starting from index 1 (see below), so for index 0 you have an invalid event handle.

for dwAdIndex := 1 to AdList.m_nAdapterCount do

begin

...

hEvent[dwAdIndex] := CreateEvent(nil, TRUE, FALSE, nil);

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