/**
* Send an TCP packet
*
* @param skbuf
*/
protected void send(IPv4Header ipHdr, TCPHeader tcpHdr, SocketBuffer skbuf)
throws SocketException {
if (DEBUG) {
if (log.isDebugEnabled()) {
log.debug("send(ipHdr, " + tcpHdr + ')');
}
}
skbuf.setTransportLayerHeader(tcpHdr);
tcpHdr.prefixTo(skbuf);
ipHdr.setDataLength(skbuf.getSize());
ipService.transmit(ipHdr, skbuf);
stat.opackets.inc();
}
/** @see org.jnode.net.TransportLayer#receive(org.jnode.net.SocketBuffer) */
public void receive(SocketBuffer skbuf) throws SocketException {
// Increment stats
stat.ipackets.inc();
// Get the IP header
final IPv4Header ipHdr = (IPv4Header) skbuf.getNetworkLayerHeader();
// Read the TCP header
final TCPHeader hdr = new TCPHeader(skbuf);
// Set the TCP header in the buffer-field
skbuf.setTransportLayerHeader(hdr);
// Remove the TCP header from the head of the buffer
skbuf.pull(hdr.getLength());
// Trim the buffer up to the length in the TCP header
skbuf.trim(hdr.getDataLength());
if (!hdr.isChecksumOk()) {
if (DEBUG) {
if (log.isDebugEnabled()) {
log.debug("Receive: badsum: " + hdr);
}
}
stat.badsum.inc();
} else {
if (DEBUG) {
if (log.isDebugEnabled()) {
log.debug("Receive: " + hdr);
}
}
// Find the corresponding control block
final TCPControlBlock cb =
(TCPControlBlock)
controlBlocks.lookup(
ipHdr.getSource(),
hdr.getSrcPort(),
ipHdr.getDestination(),
hdr.getDstPort(),
true);
if (cb == null) {
final boolean ack = hdr.isFlagAcknowledgeSet();
final boolean rst = hdr.isFlagResetSet();
stat.noport.inc();
// Port unreachable
if (ack && rst) {
// the source is also unreachable
log.debug(
"Dropping segment due to: connection refused as the source is also unreachable");
} else {
processPortUnreachable(ipHdr, hdr);
}
} else {
// Let the cb handle the receive
cb.receive(hdr, skbuf);
}
}
}
