/** Process timeout handling */
public void timeout() {
// allocation free looping
for (IPv4ControlBlock aList : list) {
final TCPControlBlock cb = (TCPControlBlock) aList;
cb.timeout();
}
}
/**
* Read data from the input buffer up to len bytes long. Block until there is data available.
*
* @param dst
* @param off
* @param len
* @return The number of bytes read
*/
public synchronized int read(byte[] dst, int off, int len) throws SocketException {
while ((dataBuffer.getUsed() == 0) && !controlBlock.isReset() && !isEOF()) {
try {
wait();
} catch (InterruptedException ex) {
// Ignore
}
}
if (controlBlock.isReset()) {
throw new SocketException("Connection reset");
} else if (isEOF()) {
return -1;
} else {
return dataBuffer.read(dst, off, len);
}
}
/**
* Process the given segment (that must be the next expected segment). The data will be send to
* the input data buffer, if there is enough space left in the buffer.
*
* @param hdr
* @param skbuf
* @return True if the segment has been fully processed, false otherwise.
* @throws SocketException
*/
private synchronized boolean processNextSegment(TCPHeader hdr, SocketBuffer skbuf)
throws SocketException {
final int seqNr = hdr.getSequenceNr();
if (seqNr != rcv_next) {
throw new IllegalArgumentException("hdr.seqNr != rcv_next");
}
// This segment is the first expected segment
// Sent it to the application if there is enough space
final int dataLength = hdr.getDataLength();
if (dataLength > dataBuffer.getFreeSize()) {
// Not enough free space, ignore this segment, it will be retransmitted.
log.debug("nextSegment dropped due to lack of space");
return false;
} else {
// Enough space, save
if (dataLength > 0) {
dataBuffer.add(skbuf, 0, dataLength);
// Update rcv_next
rcv_next += dataLength;
}
final boolean fin = hdr.isFlagFinishedSet();
final boolean syn = hdr.isFlagSynchronizeSet();
if (syn || fin) {
// SYN & FIN take up 1 seq-nr
rcv_next++;
}
if ((dataLength > 0) || fin) {
// And ACK it
controlBlock.sendACK(0, rcv_next);
}
// Notify threads blocked in read
notifyAll();
// We've processed it fully
return true;
}
}
/** @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);
}
}
}
