//htonl(0x7F000001); // 127.0.0.1
public void Append(IPEndPoint source, IPEndPoint destination, ProtocolType protocol, byte[] payload, DateTime?timestamp = null)
{
PcapItemHeader packetHeader;
Ethernet packetEthernet;
IPv4 packetIP;
byte[] sourceBytes, destinationBytes;
byte[] payloadItemHeader, payloadEthernet, payloadIP, payloadTransport, payloadData;
int index;
switch (protocol)
{
case ProtocolType.Udp:
UDP packetUDP;
packetUDP = new UDP((UInt16)source.Port, (UInt16)destination.Port, (UInt16)payload.Length);
payloadTransport = packetUDP.GetBytes();
break;
case ProtocolType.Tcp:
TCP packetTCP;
UInt16 connection1, connection2;
UInt64 seqAck;
UInt32 seq, ack;
connection1 = tcpConnectionId(source, destination);
connection2 = tcpConnectionId(destination, source);
if (tcpWindows.ContainsKey(connection1))
{
seqAck = tcpWindows[connection1];
seq = (UInt32)(seqAck >> 32);
ack = (UInt32)seqAck;
}
else
{
seq = 1;
ack = 1;
seqAck = ((UInt64)seq << 32) | ack;
tcpWindows.Add(connection1, seqAck);
}
packetTCP = new TCP((UInt16)source.Port, (UInt16)destination.Port, seq, ack);
seq += (UInt32)payload.Length;
seqAck = ((UInt64)seq << 32) | ack;
tcpWindows[connection1] = seqAck;
if (tcpWindows.ContainsKey(connection2))
{
seqAck = tcpWindows[connection2];
seq = (UInt32)(seqAck >> 32);
ack = (UInt32)payload.Length;
seqAck = ((UInt64)seq << 32) | ack;
tcpWindows[connection2] = seqAck;
}
else
{
seq = 1;
ack = (UInt32)payload.Length;
seqAck = ((UInt64)seq << 32) | ack;
tcpWindows.Add(connection2, seqAck);
}
payloadTransport = packetTCP.GetBytes();
break;
case ProtocolType.IP:
payloadTransport = new byte[] { };
break;
default:
throw new System.ArgumentException("This protocol is not supported", "protocol");
}
/* ipv4 */
packetIP = new IPv4(source.Address, destination.Address, protocol, (UInt16)(payloadTransport.Length + payload.Length));
payloadIP = packetIP.GetBytes();
/* ethernet */
sourceBytes = source.Address.GetAddressBytes();
destinationBytes = destination.Address.GetAddressBytes();
packetEthernet = new Ethernet(new byte[3] {
sourceBytes[1], sourceBytes[2], sourceBytes[3]
}, new byte[3] {
destinationBytes[1], destinationBytes[2], destinationBytes[3]
});
payloadEthernet = packetEthernet.GetBytes();
/* pcap packet header */
if (timestamp == null)
{
timestamp = DateTime.UtcNow;
}
packetHeader = new PcapItemHeader((DateTime)timestamp, (UInt32)(payloadEthernet.Length + payloadIP.Length + payloadTransport.Length + payload.Length));
payloadItemHeader = packetHeader.GetBytes();
payloadData = new byte[payloadItemHeader.Length + payloadEthernet.Length + payloadIP.Length + payloadTransport.Length + payload.Length];
index = 0;
payloadItemHeader.CopyTo(payloadData, index);
index += payloadItemHeader.Length;
payloadEthernet.CopyTo(payloadData, index);
index += payloadEthernet.Length;
payloadIP.CopyTo(payloadData, index);
index += payloadIP.Length;
payloadTransport.CopyTo(payloadData, index);
index += payloadTransport.Length;
payload.CopyTo(payloadData, index);
index += payload.Length;
if (payloadData.Length != packetHeader.length + 16)
{
throw new Exception("Error of PCap. Possible bug");
}
content.Write(payloadData, 0, payloadData.Length);
}