// test that we can seek a tcpStream beyond the length of the stream
// then back into the range of the stream and then read
// a known value
public void TestTcpStreamSeeking()
{
captureFilename = capturePre + captureFN;
// open the offline file
var dev = new CaptureFileReaderDevice(captureFilename);
dev.Open();
Assert.True(dev != null, "failed to open " + captureFilename);
TcpStream tcpStream = new TcpStream();
int i = 1; // to match the packet numbering in wireshark
PacketCapture e;
GetPacketStatus status;
while ((status = dev.GetNextPacket(out e)) == GetPacketStatus.PacketRead)
{
var rawCapture = e.GetPacket();
var p = Packet.ParsePacket(rawCapture.LinkLayerType, rawCapture.Data);
var tcpPacket = p.Extract <TcpPacket>();
// we only want the 4th packet since that is the first packet with a payload
if (i == 4)
{
tcpStream.AppendPacket(tcpPacket);
}
i++;
}
dev.Close();
// what is the length of the stream?
long length = tcpStream.Length;
Console.WriteLine("length is {0}", length);
// seek to the end of the stream
tcpStream.Seek(0, System.IO.SeekOrigin.End);
// retrieve the position
long position = tcpStream.Position;
Console.WriteLine("position is {0}", position);
// seek to the start of the stream
tcpStream.Seek(0, System.IO.SeekOrigin.Begin);
// retrieve the position
long position2 = tcpStream.Position;
Console.WriteLine("position2 is {0}", position2);
}
public void TestTcpStream()
{
Console.WriteLine(Environment.CurrentDirectory);
captureFilename = capturePre + captureFN;
// open the offline file
var dev = new CaptureFileReaderDevice(captureFilename);
dev.Open();
Assert.True(dev != null, "failed to open " + captureFilename);
TcpStream tcpStream = new TcpStream();
int i = 1; // to match the packet numbering in wireshark
GetPacketStatus status;
PacketCapture e;
while ((status = dev.GetNextPacket(out e)) == GetPacketStatus.PacketRead)
{
var rawCapture = e.GetPacket();
var p = Packet.ParsePacket(rawCapture.LinkLayerType, rawCapture.Data);
var tcpPacket = p.Extract <TcpPacket>();
Console.WriteLine("{0}", tcpPacket.ToString());
#if false
Console.WriteLine("packet_header.len is {0}", p.Length);
Console.WriteLine("{0}", p.ToString());
int x;
for (x = 0; x < packet_header.len; x++)
{
if ((x % 16) == 0)
{
printf("\n");
}
printf("%02x ", pPacket[x]);
}
printf("\n");
#endif
Console.WriteLine("********************");
Console.WriteLine("i == {0}", i);
// and hand it off to the tcp_stream
tcpStream.AppendPacket(tcpPacket);
Console.WriteLine("Position {0}", tcpStream.Position);
Console.WriteLine("Length {0}", tcpStream.Length);
// make sure the length and position is correct
// and Seek() to the end of the stream
if (i == 4)
{
// we expect our length to be 38
long expectedLength = 38;
Assert.Equal(expectedLength, tcpStream.Length);
// advance through these bytes
tcpStream.Seek(0, System.IO.SeekOrigin.End);
// make sure that our position is correct
Assert.Equal(expectedLength, tcpStream.Position);
}
if (i == 5)
{
// read the first 26 bytes into a memory stream
// these are header bytes, we don't really want them
int bytesToRead = 26;
byte[] dataBuffer1 = new byte[bytesToRead];
tcpStream.Read(dataBuffer1, 0, dataBuffer1.Length);
/////////////////////////////////////
// Step two, reading at the current location
// save the position
long position = tcpStream.Position;
// read bytes at that location
bytesToRead = 14;
byte[] dataBuffer2 = new byte[bytesToRead];
tcpStream.Read(dataBuffer2, 0, dataBuffer2.Length);
System.Text.ASCIIEncoding enc = new System.Text.ASCIIEncoding();
string actualString = enc.GetString(dataBuffer2, 0, dataBuffer2.Length);
Console.WriteLine("actualString '{0}'", actualString);
// expected string
string expectedString = "diffie-hellman";
// do our strings match?
Assert.Equal(expectedString, actualString);
// make sure our position advanced by the number of bytes we read
Assert.Equal((position + bytesToRead), tcpStream.Position);
}
Console.WriteLine("i = {0}", i);
i++;
}
Console.WriteLine();
dev.Close();
}