Some small protocol fixes. Correct serialization of version and address messages.

Also require the height of the best chain to be specified when setting up a NetworkConnection. This API is getting too complicated and will be simplified soon. 

For now these fixes resolve a bug whereby the peer would not send us new blocks discovered during a session (as it thought we already had them).

src/com/google/bitcoin/core/NetworkConnection.java

@@ -61,12 +61,15 @@ public class NetworkConnection {
     /**
      * Connect to the given IP address using the port specified as part of the network parameters. Once construction
      * is complete a functioning network channel is set up and running.
+     *
      * @param remoteIp IP address to connect to. IPv6 is not currently supported by BitCoin.
      * @param params Defines which network to connect to and details of the protocol.
+     * @param bestHeight How many blocks are in our best chain
      * @throws IOException if there is a network related failure.
      * @throws ProtocolException if the version negotiation failed.
      */
-    public NetworkConnection(InetAddress remoteIp, NetworkParameters params) throws IOException, ProtocolException {
+    public NetworkConnection(InetAddress remoteIp, NetworkParameters params, int bestHeight)
+            throws IOException, ProtocolException {
         this.params = params;
         this.remoteIp = remoteIp;
         socket = new Socket(remoteIp, params.port);
@@ -75,7 +78,7 @@ public class NetworkConnection {
 
         // Announce ourselves. This has to come first to connect to clients beyond v0.30.20.2 which wait to hear
         // from us until they send their version message back.
-        writeMessage(MSG_VERSION, new VersionMessage(params));
+        writeMessage(MSG_VERSION, new VersionMessage(params, bestHeight));
         // When connecting, the remote peer sends us a version message with various bits of
         // useful data in it. We need to know the peer protocol version before we can talk to it.
         versionMessage = (VersionMessage) readMessage();

src/com/google/bitcoin/core/PeerAddress.java

@@ -42,15 +42,18 @@ public class PeerAddress extends Message {
         super(params, payload, offset, protocolVersion);
     }
     
-    public PeerAddress(InetAddress addr, int port) {
+    public PeerAddress(InetAddress addr, int port, int protocolVersion) {
         this.addr = addr;
         this.port = port;
+        this.protocolVersion = protocolVersion;
     }
     
     public void bitcoinSerializeToStream(OutputStream stream) throws IOException {
+        if (protocolVersion >= 31402) {
             int secs = (int)(new Date().getTime() / 1000);
             uint32ToByteStreamLE(secs, stream);
-        uint64ToByteStreamLE(BigInteger.ZERO, stream);
+        }
+        uint64ToByteStreamLE(BigInteger.ZERO, stream);  // nServices.
         // Java does not provide any utility to map an IPv4 address into IPv6 space, so we have to do it by hand.
         byte[] ipBytes = addr.getAddress();
         if (ipBytes.length == 4) {

src/com/google/bitcoin/core/VersionMessage.java

@@ -18,7 +18,6 @@ package com.google.bitcoin.core;
 
 import java.io.IOException;
 import java.io.OutputStream;
-import java.math.BigInteger;
 import java.net.InetAddress;
 import java.net.UnknownHostException;
 
@@ -52,7 +51,7 @@ public class VersionMessage extends Message {
         super(params, msg, 0);
     }
 
-    public VersionMessage(NetworkParameters params) {
+    public VersionMessage(NetworkParameters params, int newBestHeight) {
         super(params);
         clientVersion = NetworkParameters.PROTOCOL_VERSION;
         localServices = 0;
@@ -60,13 +59,13 @@ public class VersionMessage extends Message {
         // Note that the official client doesn't do anything with these, and finding out your own external IP address
         // is kind of tricky anyway, so we just put nonsense here for now.
         try {
-            myAddr = new PeerAddress(InetAddress.getLocalHost(), params.port);
+            myAddr = new PeerAddress(InetAddress.getLocalHost(), params.port, 0);
-            theirAddr = new PeerAddress(InetAddress.getLocalHost(), params.port);
+            theirAddr = new PeerAddress(InetAddress.getLocalHost(), params.port, 0);
         } catch (UnknownHostException e) {
             throw new RuntimeException(e);  // Cannot happen.
         }
-        subVer = "BitCoinJ 0.1.99";
+        subVer = "BitCoinJ 0.2";
-        bestHeight = 0;
+        bestHeight = newBestHeight;
     }
     
     @Override
@@ -92,8 +91,9 @@ public class VersionMessage extends Message {
     public void bitcoinSerializeToStream(OutputStream buf) throws IOException {
         Utils.uint32ToByteStreamLE(clientVersion, buf);
         Utils.uint32ToByteStreamLE(localServices, buf);
-        Utils.uint32ToByteStreamLE(time >> 32, buf);
+        Utils.uint32ToByteStreamLE(localServices >> 32, buf);
         Utils.uint32ToByteStreamLE(time, buf);
+        Utils.uint32ToByteStreamLE(time >> 32, buf);
         try {
             // My address.
             myAddr.bitcoinSerializeToStream(buf);

src/com/google/bitcoin/examples/PingService.java

@@ -31,11 +31,13 @@ import java.util.concurrent.TimeUnit;
  */
 public class PingService {
     public static void main(String[] args) throws Exception {
-        final NetworkParameters params = NetworkParameters.prodNet();
+        boolean testNet = args.length > 0 && args[0].equalsIgnoreCase("testnet");
+        final NetworkParameters params = testNet ? NetworkParameters.testNet() : NetworkParameters.prodNet();
+        String filePrefix = testNet ? "pingservice-testnet" : "pingservice-prodnet";
 
         // Try to read the wallet from storage, create a new one if not possible.
         Wallet wallet;
-        final File walletFile = new File("pingservice.wallet");
+        final File walletFile = new File(filePrefix + ".wallet");
         try {
             wallet = Wallet.loadFromFile(walletFile);
         } catch (IOException e) {
@@ -48,11 +50,12 @@ public class PingService {
 
         // Load the block chain, if there is one stored locally.
         System.out.println("Reading block store from disk");
-        BlockStore blockStore = new DiskBlockStore(params, new File("pingservice.blockchain"));
+        BlockStore blockStore = new DiskBlockStore(params, new File(filePrefix + ".blockchain"));
 
         // Connect to the localhost node.
         System.out.println("Connecting ...");
-        NetworkConnection conn = new NetworkConnection(InetAddress.getLocalHost(), params);
+        NetworkConnection conn = new NetworkConnection(InetAddress.getLocalHost(), params,
+                                                       blockStore.getChainHead().getHeight());
         BlockChain chain = new BlockChain(params, wallet, blockStore);
         final Peer peer = new Peer(params, conn, chain);
         peer.start();
@@ -61,7 +64,7 @@ public class PingService {
         wallet.addEventListener(new WalletEventListener() {
             public void onCoinsReceived(Wallet w, Transaction tx, BigInteger prevBalance, BigInteger newBalance) {
                 // Running on a peer thread.
-
+                assert !newBalance.equals(BigInteger.ZERO);
                 // It's impossible to pick one specific identity that you receive coins from in BitCoin as there
                 // could be inputs from many addresses. So instead we just pick the first and assume they were all
                 // owned by the same person.

src/com/google/bitcoin/examples/PrivateKeys.java

@@ -46,7 +46,7 @@ public class PrivateKeys {
             wallet.addKey(key);
 
             // Find the transactions that involve those coins.
-            NetworkConnection conn = new NetworkConnection(InetAddress.getLocalHost(), params);
+            NetworkConnection conn = new NetworkConnection(InetAddress.getLocalHost(), params, 0);
             BlockChain chain = new BlockChain(params, wallet, new MemoryBlockStore(params));
             Peer peer = new Peer(params, conn, chain);
             peer.start();