/**
* Deliver a packet to the corresponding protocol
*
* @param hdr
* @param skbuf
*/
private void deliver(IPv4Header hdr, SocketBuffer skbuf) throws SocketException {
final IPv4Protocol protocol;
try {
protocol = getProtocol(hdr.getProtocol());
protocol.receive(skbuf);
} catch (NoSuchProtocolException ex) {
log.debug(
"Found unknown IP src="
+ hdr.getSource()
+ ", dst="
+ hdr.getDestination()
+ ", prot=0x"
+ NumberUtils.hex(hdr.getProtocol(), 2));
}
}
/**
* Process a packet that has been received and matches getType()
*
* @param skbuf
* @param deviceAPI
* @throws SocketException
*/
public void receive(SocketBuffer skbuf, NetDeviceAPI deviceAPI) throws SocketException {
// Update statistics
stat.ipackets.inc();
// Get IP header
final IPv4Header hdr = new IPv4Header(skbuf);
if (!hdr.isChecksumOk()) {
stat.badsum.inc();
return;
}
// Set the header object in the buffer-field
skbuf.setNetworkLayerHeader(hdr);
// Remove header from skbuf-data
skbuf.pull(hdr.getLength());
// Trim the end of the message, to we have a valid length
skbuf.trim(hdr.getDataLength());
// Now test if the size of the buffer equals the datalength in the
// header, if now ignore the packet
if (skbuf.getSize() < hdr.getDataLength()) {
stat.badlen.inc();
return;
}
// Update the ARP cache for the source address
updateARPCache(skbuf.getLinkLayerHeader().getSourceAddress(), hdr.getSourceAddress());
// Get my IP address
final IPv4ProtocolAddressInfo myAddrInfo =
(IPv4ProtocolAddressInfo) deviceAPI.getProtocolAddressInfo(getProtocolID());
if (myAddrInfo == null) {
stat.nodevaddr.inc();
}
// Should I process this packet, or is it for somebody else?
final IPv4Address dstAddr = hdr.getDestination();
final boolean shouldProcess;
if (myAddrInfo != null) {
shouldProcess = myAddrInfo.contains(dstAddr);
} else {
// I don't have an IP address yet, if the linklayer says
// it is for me, we'll process it, otherwise we'll drop it.
shouldProcess = !skbuf.getLinkLayerHeader().getDestinationAddress().isBroadcast();
}
if (!shouldProcess) {
// log.debug("IPPacket not for me, ignoring (dst=" + dstAddr + ")");
return;
}
// Is it a fragment?
if (hdr.isFragment()) {
// Yes it is a fragment
stat.fragments.inc();
deliverFragment(hdr, skbuf);
} else {
// It is a complete packet, find the protocol handler
// and let it do the rest
deliver(hdr, skbuf);
}
// Do a cleanup of the fragmentlist from time to time
final long now = System.currentTimeMillis();
if ((now - lastFragmentCleanup) >= (IP_FRAGTIMEOUT * 2)) {
removeDeadFragments();
}
}
/** @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);
}
}
}
