/**
* a DatagramChannel has data ready - process all the pending packets, whether its for a
* rdpserversocket or rdpconnection.
*/
void processActiveChannel(DatagramChannel dc) throws ClosedChannelException {
RDPPacket packet;
int count = 0;
// read in the packet
try {
Set<RDPConnection> needsAckConnections = new HashSet<RDPConnection>();
while ((packet = RDPServer.receivePacket(dc)) != null) {
if (Log.loggingNet)
Log.net(
"RDPServer.processActiveChannel: Starting iteration with count of "
+ count
+ " packets");
// see if there is a connection already for this packet
InetAddress remoteAddr = packet.getInetAddress();
int remotePort = packet.getPort();
int localPort = dc.socket().getLocalPort();
ConnectionInfo conInfo = new ConnectionInfo(remoteAddr, remotePort, localPort);
RDPConnection con = RDPServer.getConnection(dc, conInfo);
if (con != null) {
if (Log.loggingNet)
Log.net("RDPServer.processActiveChannel: found an existing connection: " + con);
count++;
if (processExistingConnection(con, packet)) needsAckConnections.add(con);
// Prevent this from blocking getActiveChannels by
// putting an upper bound on the number of packets
// processed
if (count >= 20) break;
continue;
} else {
Log.net("RDPServer.processActiveChannel: did not find an existing connection");
}
// there is no connection,
// see if there is a socket listening for new connection
RDPServerSocket rdpSocket = RDPServer.getRDPSocket(dc);
if (rdpSocket != null) {
count++;
processNewConnection(rdpSocket, packet);
return;
}
return;
}
// Finally, send out the acks
for (RDPConnection con : needsAckConnections) {
RDPPacket replyPacket = new RDPPacket(con);
con.sendPacketImmediate(replyPacket, false);
}
} catch (ClosedChannelException ex) {
Log.error("RDPServer.processActiveChannel: ClosedChannel " + dc.socket());
throw ex;
} finally {
if (Log.loggingNet)
Log.net("RDPServer.processActiveChannel: Returning after processing " + count + " packets");
}
}
/** rdpserversocket wants to bind on a local port */
static DatagramChannel bind(Integer port, int receiveBufferSize)
throws java.net.BindException, java.io.IOException, java.net.SocketException {
lock.lock();
try {
// see if there is an existing datagramchannel bound to this port
DatagramChannel dc = channelMap.get(port);
if (dc != null) {
throw new java.net.BindException("RDPServer.bind: port is already used");
}
// make a new datagram channel
dc = DatagramChannel.open();
dc.configureBlocking(false);
dc.socket().setReceiveBufferSize(receiveBufferSize);
if (port == null) {
if (Log.loggingNet) Log.net("RDPServer.bind: binding to a random system port");
dc.socket().bind(null);
} else {
if (Log.loggingNet) Log.net("RDPServer.bind: binding to port " + port);
dc.socket().bind(new InetSocketAddress(port));
}
int resultingPort = dc.socket().getLocalPort();
if (Log.loggingNet) Log.net("RDPServer.bind: resulting port=" + resultingPort);
// add the channel to the channel map
channelMap.put(resultingPort, dc);
if (Log.loggingNet) Log.net("RDPServer.bind: added dc to channel map");
// add the channel to the newChannelsSet
// we want to register this channel with the selector
// but the selector thread needs to do that,
// so place it in this set, and wake up the selector
newChannelSet.add(dc);
if (Log.loggingNet) Log.net("RDPServer.bind: added dc to newChannelSet");
// in case the rdpserver was waiting while it had no sockets,
// signal it
channelMapNotEmpty.signal();
Log.net("RDPServer.bind: signalled channel map not empty condition");
// wakeup the selector -
// it needs to register the new channel with itself
selector.wakeup();
if (Log.loggingNet) Log.net("RDPServer.bind: woke up selector");
return dc;
} finally {
lock.unlock();
}
}
/**
* removes this connection from the connections map the datagram channel still sticks around in
* case it needs to be reused
*/
static void removeConnection(RDPConnection con) {
lock.lock();
try {
if (Log.loggingNet) Log.net("RDPServer.removeConnection: removing con " + con);
con.setState(RDPConnection.CLOSED);
DatagramChannel dc = con.getDatagramChannel();
// first we get the set of connections attached to the given dc
Map<ConnectionInfo, RDPConnection> dcConMap = allConMap.get(dc);
if (dcConMap == null) {
throw new MVRuntimeException("RDPServer.removeConnection: cannot find dc");
}
int localPort = con.getLocalPort();
int remotePort = con.getRemotePort();
InetAddress remoteAddr = con.getRemoteAddr();
ConnectionInfo conInfo = new ConnectionInfo(remoteAddr, remotePort, localPort);
Object rv = dcConMap.remove(conInfo);
if (rv == null) {
throw new MVRuntimeException("RDPServer.removeConnection: could not find the connection");
}
// close the datagramchannel if needed
// conditions: no other connections on this datagramchannel
// no socket listening on this datagramchannel
if (dcConMap.isEmpty()) {
Log.net("RDPServer.removeConnection: no other connections for this datagramchannel (port)");
// there are no more connections on this datagram channel
// check if there is a serversocket listening
if (getRDPSocket(dc) == null) {
Log.net("RDPServer.removeConnection: no socket listening on this port - closing");
// no socket either, close the datagramchannel
dc.socket().close();
channelMap.remove(localPort);
Log.net("RDPServer.removeConnection: closed and removed datagramchannel/socket");
} else {
Log.net("RDPServer.removeConnection: there is a socket listening on this port");
}
} else {
Log.net("RDPServer.removeConnection: there are other connections on this port");
}
} finally {
lock.unlock();
}
}