io.pkts.framer.TCPFramer Maven / Gradle / Ivy
/**
*
*/
package io.pkts.framer;
import io.pkts.buffer.Buffer;
import io.pkts.packet.IPPacket;
import io.pkts.packet.TCPPacket;
import io.pkts.packet.impl.TcpPacketImpl;
import io.pkts.protocol.Protocol;
import java.io.IOException;
/**
* @author [email protected]
*
*/
public final class TCPFramer implements Framer {
/**
*
*/
public TCPFramer() {
}
/**
* {@inheritDoc}
*/
@Override
public Protocol getProtocol() {
return Protocol.UDP;
}
/**
* {@inheritDoc}
*/
@Override
public TCPPacket frame(final IPPacket parent, final Buffer buffer) throws IOException {
if (parent == null) {
throw new IllegalArgumentException("The parent frame cannot be null");
}
// The TCP header is at least 20 bytes and if there are options
// there can be an additional 40 bytes. The offset will tell us
// how may 32-bit words there are.
final Buffer headers = buffer.readBytes(20);
Buffer options = null;
Buffer payload = null;
final byte offset = headers.getByte(12);
// once again, the minimum size of a tcp header is 5 words
// and since we already have read that off the buffer, this
// is what we have left to read
final int size = (offset >> 4 & 0x0F) - 5;
if (size > 0) {
options = buffer.readBytes(size * 4);
}
// to handle packets that has no payload (e.g a syn packet)
if (buffer.hasReadableBytes()) {
payload = buffer.slice();
}
return new TcpPacketImpl(parent, headers, options, payload);
}
/**
* {@inheritDoc}
*/
@Override
public boolean accept(final Buffer data) throws IOException {
// TODO Auto-generated method stub
return false;
}
}