MessageHandler.java

package org.ripple.power.txns.btc;

import java.io.EOFException;

public class MessageHandler implements Runnable {

    /** Message handler shutdown requested */
    private boolean messageShutdown = false;

    /**
     * Creates a message handler
     */
    public MessageHandler() {
    }

    /**
     * Processes messages and returns responses
     */
    @Override
    public void run() {
        BTCLoader.info("Message handler started");
        //
        // Process messages until we are shutdown
        //
        try {
            while (true) {
                Message msg = BTCLoader.messageQueue.take();
                if (messageShutdown)
                    break;
                processMessage(msg);
            }
        } catch (InterruptedException exc) {
            BTCLoader.warn("Message handler interrupted", exc);
        } catch (Throwable exc) {
            BTCLoader.error("Runtime exception while processing messages", exc);
        }
        //
        // Stopping
        //
        BTCLoader.info("Message handler stopped");
    }

    /**
     * Shutdown the message handler
     */
    public void shutdown() {
        try {
            messageShutdown = true;
            BTCLoader.messageQueue.put(new ShutdownMessage());
        } catch (InterruptedException exc) {
            BTCLoader.warn("Message handler shutdown interrupted", exc);
        }
    }

    /**
     * Process a message and return a response
     *
     * @param       msg             Message
     */
    private void processMessage(Message msg) throws InterruptedException {
        Peer peer = msg.getPeer();
        if (peer == null) {
            BTCLoader.dumpData("Message With No Peer", msg.getBuffer().array());
            return;
        }
        PeerAddress address = peer.getAddress();
        int reasonCode = 0;
        try {
            MessageProcessor.processMessage(msg, BTCLoader.networkMessageListener);
            msg.setBuffer(null);
        } catch (EOFException exc) {
            MessageHeader.MessageCommand cmdOp = msg.getCommand();
            String cmdName = (cmdOp!=null ? cmdOp.toString().toLowerCase() : "N/A");
            BTCLoader.error(String.format("End-of-data while processing '%s' message from %s",
                                    cmdName, address), exc);
            reasonCode = RejectMessage.REJECT_MALFORMED;
            if (cmdOp == MessageHeader.MessageCommand.TX)
                BTCLoader.txRejected.incrementAndGet();
            else if (cmdOp == MessageHeader.MessageCommand.VERSION)
                peer.setDisconnect(true);
            if (peer.getVersion() >= 70002) {
                Message rejectMsg = RejectMessage.buildRejectMessage(peer, cmdName, reasonCode, exc.getMessage());
                msg.setBuffer(rejectMsg.getBuffer());
                msg.setCommand(rejectMsg.getCommand());
            } else {
                msg.setBuffer(null);
            }
        } catch (VerificationException exc) {
            MessageHeader.MessageCommand cmdOp = msg.getCommand();
            String cmdName = (cmdOp!=null ? cmdOp.toString().toLowerCase() : "N/A");
            BTCLoader.error(String.format("Message verification failed for '%s' message from %s\n  %s\n  %s",
                                    cmdName, address, exc.getMessage(), exc.getHash()));
            reasonCode = exc.getReason();
            if (cmdOp == MessageHeader.MessageCommand.TX)
                BTCLoader.txRejected.incrementAndGet();
            else if (cmdOp == MessageHeader.MessageCommand.VERSION)
                peer.setDisconnect(true);
            if (peer.getVersion() >= 70002) {
                Message rejectMsg = RejectMessage.buildRejectMessage(peer, cmdName, reasonCode,
                                                                     exc.getMessage(), exc.getHash());
                msg.setBuffer(rejectMsg.getBuffer());
                msg.setCommand(rejectMsg.getCommand());
            } else {
                msg.setBuffer(null);
            }
        }
        //
        // Add the message to the completed message list and wakeup the network listener.  We will
        // bump the banscore for the peer if the message was rejected because it was malformed
        // or invalid.  We will ban the peer if it is using an obsolete protocol.
        //
        BTCLoader.completedMessages.add(msg);
        int banScore;
        switch (reasonCode) {
            case RejectMessage.REJECT_MALFORMED:
            case RejectMessage.REJECT_INVALID:
                banScore = 5;
                break;
            case RejectMessage.REJECT_OBSOLETE:
                banScore = BTCLoader.MAX_BAN_SCORE;
                break;
            default:
                banScore = 0;
        }
        if (banScore > 0) {
            synchronized(peer) {
                banScore += peer.getBanScore();
                peer.setBanScore(banScore);
                if (banScore >= BTCLoader.MAX_BAN_SCORE)
                    peer.setDisconnect(true);
            }
        }
        BTCLoader.networkHandler.wakeup();
    }
}