// here we search through all the frag we have collected to see if one fits
private bool checkFragments()
{
TcpFragment prev = null;
TcpFragment current = _fragment;
while (current != null)
{
if (current.sequenceNumber == _sequenceNumber)
{
// this fragment fits the stream
_sequenceNumber += current.length;
if (current.data != null)
{
writeData(current.data, current.ppacket, "next packet from fragments");
}
//_sequenceNumber += current.length;
if (prev != null)
{
prev.next = current.next;
}
else
{
_fragment = current.next;
}
current.data = null;
current = null;
return(true);
}
prev = current;
current = current.next;
}
return(false);
}
/* here we search through all the frag we have collected to see if one fits */
bool check_fragments(int index)
{
TcpFragment prev = null;
TcpFragment current;
current = _fragments[index];
while (current != null)
{
if (current.sequenceNumber == _sequenceNumbers[index])
{
/* this fragment fits the stream */
if (current.data != null)
{
write_packet_data(index, current.data);
}
_sequenceNumbers[index] += current.length;
if (prev != null)
{
prev.next = current.next;
}
else
{
_fragments[index] = current.next;
}
current.data = null;
current = null;
return(true);
}
prev = current;
current = current.next;
}
return(false);
}
private void reassemble_tcp(uint sequenceNumber, uint length, byte[] data, uint dataLength, bool synflag, uint sourceAdress, ushort sourcePort, uint destinationAdress, ushort destinationPort)
{
//long srcx, dstx;
int src_index, j;
bool first = false;
//ulong newseq;
uint newSequenceNumber;
TcpFragment tmp_frag;
src_index = -1;
/* Now check if the packet is for this connection. */
uint srcx = sourceAdress;
uint dstx = destinationAdress;
/* Check to see if we have seen this source IP and port before.
* (Yes, we have to check both source IP and port; the connection
* might be between two different ports on the same machine.) */
for (j = 0; j < 2; j++)
{
if (_sourceAdresses[j] == srcx && _sourcePorts[j] == sourcePort)
{
src_index = j;
}
}
/* we didn't find it if src_index == -1 */
if (src_index < 0)
{
/* assign it to a src_index and get going */
for (j = 0; j < 2; j++)
{
if (_sourcePorts[j] == 0)
{
_sourceAdresses[j] = srcx;
_sourcePorts[j] = sourcePort;
src_index = j;
first = true;
break;
}
}
}
if (src_index < 0)
{
throw new Exception("ERROR in reassemble_tcp: Too many addresses!");
}
if (dataLength < length)
{
_incompleteTcpStream = true;
}
/* now that we have filed away the srcs, lets get the sequence number stuff
* figured out */
if (first)
{
/* this is the first time we have seen this src's sequence number */
_sequenceNumbers[src_index] = sequenceNumber + length;
if (synflag)
{
_sequenceNumbers[src_index]++;
}
/* write out the packet data */
write_packet_data(src_index, data);
return;
}
/* if we are here, we have already seen this src, let's
* try and figure out if this packet is in the right place */
if (sequenceNumber < _sequenceNumbers[src_index])
{
/* this sequence number seems dated, but
* check the end to make sure it has no more
* info than we have already seen */
newSequenceNumber = sequenceNumber + length;
if (newSequenceNumber > _sequenceNumbers[src_index])
{
//ulong new_len;
uint new_len;
/* this one has more than we have seen. let's get the
* payload that we have not seen. */
new_len = _sequenceNumbers[src_index] - sequenceNumber;
if (dataLength <= new_len)
{
data = null;
dataLength = 0;
_incompleteTcpStream = true;
}
else
{
dataLength -= new_len;
byte[] tmpData = new byte[dataLength];
for (ulong i = 0; i < dataLength; i++)
{
tmpData[i] = data[i + new_len];
}
data = tmpData;
}
sequenceNumber = _sequenceNumbers[src_index];
length = newSequenceNumber - _sequenceNumbers[src_index];
/* this will now appear to be right on time :) */
}
}
if (sequenceNumber == _sequenceNumbers[src_index])
{
/* right on time */
_sequenceNumbers[src_index] += length;
if (synflag)
{
_sequenceNumbers[src_index]++;
}
if (data != null)
{
write_packet_data(src_index, data);
}
/* done with the packet, see if it caused a fragment to fit */
while (check_fragments(src_index))
{
;
}
}
else
{
/* out of order packet */
if (dataLength > 0 && sequenceNumber > _sequenceNumbers[src_index])
{
tmp_frag = new TcpFragment();
tmp_frag.data = data;
tmp_frag.sequenceNumber = sequenceNumber;
tmp_frag.length = length;
tmp_frag.dataLength = dataLength;
if (_fragments[src_index] != null)
{
tmp_frag.next = _fragments[src_index];
}
else
{
tmp_frag.next = null;
}
_fragments[src_index] = tmp_frag;
}
}
}
// here we search through all the frag we have collected to see if one fits
private bool checkFragments()
{
TcpFragment prev = null;
TcpFragment current = _fragment;
while (current != null)
{
if (current.sequenceNumber == _sequenceNumber)
{
// this fragment fits the stream
_sequenceNumber += current.length;
if (current.data != null)
writeData(current.data, current.ppacket, "next packet from fragments");
//_sequenceNumber += current.length;
if (prev != null)
prev.next = current.next;
else
_fragment = current.next;
current.data = null;
current = null;
return true;
}
prev = current;
current = current.next;
}
return false;
}
public void Add(Packet packet)
{
_packet = packet;
TcpDatagram tcp = packet.Ethernet.IpV4.Tcp;
// if the paylod length is zero bail out
uint length = (uint)tcp.PayloadLength;
if (length == 0)
return;
//uint dataLength
byte[] data = tcp.Payload.ToArray();
uint dataLength = (uint)data.Length;
if (dataLength < length)
_incompleteTcpStream = true;
uint sequenceNumber = tcp.SequenceNumber;
// now that we have filed away the srcs, lets get the sequence number stuff figured out
if (_first)
{
// this is the first time we have seen this src's sequence number
_sequenceNumber = sequenceNumber + length;
if (tcp.IsSynchronize)
_sequenceNumber++;
if (!(!tcp.IsPush && dataLength == 1 && length == 1 && data[0] == 0))
writeData(data, _ppacket, "first packet");
_first = false;
return;
}
// if we are here, we have already seen this src, let's try and figure out if this packet is in the right place
if (sequenceNumber < _sequenceNumber)
{
// this sequence number seems dated, but check the end to make sure it has no more info than we have already seen
uint newSequenceNumber = sequenceNumber + length;
if (newSequenceNumber > _sequenceNumber)
{
// this one has more than we have seen. let's get the payload that we have not seen.
uint new_len = _sequenceNumber - sequenceNumber;
if (dataLength <= new_len)
{
data = null;
dataLength = 0;
_incompleteTcpStream = true;
}
else
{
dataLength -= new_len;
byte[] tmpData = new byte[dataLength];
for (uint i = 0; i < dataLength; i++)
tmpData[i] = data[i + new_len];
data = tmpData;
}
sequenceNumber = _sequenceNumber;
length = newSequenceNumber - _sequenceNumber;
// this will now appear to be right on time :)
}
}
if (sequenceNumber == _sequenceNumber)
{
// right on time
_sequenceNumber += length;
if (tcp.IsSynchronize)
_sequenceNumber++;
if (data != null)
writeData(data, _ppacket, "next packet");
// done with the packet, see if it caused a fragment to fit
while (checkFragments())
;
}
else
{
// out of order packet
if (dataLength > 0 && sequenceNumber > _sequenceNumber)
{
TcpFragment tmp_frag = new TcpFragment();
tmp_frag.data = data;
tmp_frag.sequenceNumber = sequenceNumber;
tmp_frag.length = length;
tmp_frag.dataLength = dataLength;
tmp_frag.ppacket = _ppacket;
if (_fragment != null)
tmp_frag.next = _fragment;
else
tmp_frag.next = null;
_fragment = tmp_frag;
}
}
}
private void reassemble_tcp(uint sequenceNumber, uint length, byte[] data, uint dataLength, bool synflag, uint sourceAdress, ushort sourcePort, uint destinationAdress, ushort destinationPort)
{
//long srcx, dstx;
int src_index, j;
bool first = false;
//ulong newseq;
uint newSequenceNumber;
TcpFragment tmp_frag;
src_index = -1;
/* Now check if the packet is for this connection. */
uint srcx = sourceAdress;
uint dstx = destinationAdress;
/* Check to see if we have seen this source IP and port before.
(Yes, we have to check both source IP and port; the connection
might be between two different ports on the same machine.) */
for (j = 0; j < 2; j++)
{
if (_sourceAdresses[j] == srcx && _sourcePorts[j] == sourcePort)
{
src_index = j;
}
}
/* we didn't find it if src_index == -1 */
if (src_index < 0)
{
/* assign it to a src_index and get going */
for (j = 0; j < 2; j++)
{
if (_sourcePorts[j] == 0)
{
_sourceAdresses[j] = srcx;
_sourcePorts[j] = sourcePort;
src_index = j;
first = true;
break;
}
}
}
if (src_index < 0)
{
throw new Exception("ERROR in reassemble_tcp: Too many addresses!");
}
if (dataLength < length)
{
_incompleteTcpStream = true;
}
/* now that we have filed away the srcs, lets get the sequence number stuff
figured out */
if (first)
{
/* this is the first time we have seen this src's sequence number */
_sequenceNumbers[src_index] = sequenceNumber + length;
if (synflag)
{
_sequenceNumbers[src_index]++;
}
/* write out the packet data */
write_packet_data(src_index, data);
return;
}
/* if we are here, we have already seen this src, let's
try and figure out if this packet is in the right place */
if (sequenceNumber < _sequenceNumbers[src_index])
{
/* this sequence number seems dated, but
check the end to make sure it has no more
info than we have already seen */
newSequenceNumber = sequenceNumber + length;
if (newSequenceNumber > _sequenceNumbers[src_index])
{
//ulong new_len;
uint new_len;
/* this one has more than we have seen. let's get the
payload that we have not seen. */
new_len = _sequenceNumbers[src_index] - sequenceNumber;
if (dataLength <= new_len)
{
data = null;
dataLength = 0;
_incompleteTcpStream = true;
}
else
{
dataLength -= new_len;
byte[] tmpData = new byte[dataLength];
for (ulong i = 0; i < dataLength; i++)
tmpData[i] = data[i + new_len];
data = tmpData;
}
sequenceNumber = _sequenceNumbers[src_index];
length = newSequenceNumber - _sequenceNumbers[src_index];
/* this will now appear to be right on time :) */
}
}
if (sequenceNumber == _sequenceNumbers[src_index])
{
/* right on time */
_sequenceNumbers[src_index] += length;
if (synflag) _sequenceNumbers[src_index]++;
if (data != null)
{
write_packet_data(src_index, data);
}
/* done with the packet, see if it caused a fragment to fit */
while (check_fragments(src_index))
;
}
else
{
/* out of order packet */
if (dataLength > 0 && sequenceNumber > _sequenceNumbers[src_index])
{
tmp_frag = new TcpFragment();
tmp_frag.data = data;
tmp_frag.sequenceNumber = sequenceNumber;
tmp_frag.length = length;
tmp_frag.dataLength = dataLength;
if (_fragments[src_index] != null)
{
tmp_frag.next = _fragments[src_index];
}
else
{
tmp_frag.next = null;
}
_fragments[src_index] = tmp_frag;
}
}
}
public void Add(Packet packet)
{
_packet = packet;
TcpDatagram tcp = packet.Ethernet.IpV4.Tcp;
// if the paylod length is zero bail out
uint length = (uint)tcp.PayloadLength;
if (length == 0)
{
return;
}
//uint dataLength
byte[] data = tcp.Payload.ToArray();
uint dataLength = (uint)data.Length;
if (dataLength < length)
{
_incompleteTcpStream = true;
}
uint sequenceNumber = tcp.SequenceNumber;
// now that we have filed away the srcs, lets get the sequence number stuff figured out
if (_first)
{
// this is the first time we have seen this src's sequence number
_sequenceNumber = sequenceNumber + length;
if (tcp.IsSynchronize)
{
_sequenceNumber++;
}
if (!(!tcp.IsPush && dataLength == 1 && length == 1 && data[0] == 0))
{
writeData(data, _ppacket, "first packet");
}
_first = false;
return;
}
// if we are here, we have already seen this src, let's try and figure out if this packet is in the right place
if (sequenceNumber < _sequenceNumber)
{
// this sequence number seems dated, but check the end to make sure it has no more info than we have already seen
uint newSequenceNumber = sequenceNumber + length;
if (newSequenceNumber > _sequenceNumber)
{
// this one has more than we have seen. let's get the payload that we have not seen.
uint new_len = _sequenceNumber - sequenceNumber;
if (dataLength <= new_len)
{
data = null;
dataLength = 0;
_incompleteTcpStream = true;
}
else
{
dataLength -= new_len;
byte[] tmpData = new byte[dataLength];
for (uint i = 0; i < dataLength; i++)
{
tmpData[i] = data[i + new_len];
}
data = tmpData;
}
sequenceNumber = _sequenceNumber;
length = newSequenceNumber - _sequenceNumber;
// this will now appear to be right on time :)
}
}
if (sequenceNumber == _sequenceNumber)
{
// right on time
_sequenceNumber += length;
if (tcp.IsSynchronize)
{
_sequenceNumber++;
}
if (data != null)
{
writeData(data, _ppacket, "next packet");
}
// done with the packet, see if it caused a fragment to fit
while (checkFragments())
{
;
}
}
else
{
// out of order packet
if (dataLength > 0 && sequenceNumber > _sequenceNumber)
{
TcpFragment tmp_frag = new TcpFragment();
tmp_frag.data = data;
tmp_frag.sequenceNumber = sequenceNumber;
tmp_frag.length = length;
tmp_frag.dataLength = dataLength;
tmp_frag.ppacket = _ppacket;
if (_fragment != null)
{
tmp_frag.next = _fragment;
}
else
{
tmp_frag.next = null;
}
_fragment = tmp_frag;
}
}
}
