Add UPnP support for peer discovery. Resolves #1036

rskj-core/build.gradle

@@ -68,6 +68,7 @@ ext {
     logbackVersion = '1.2.2'
     bitcoinjVersion = '0.14.4-rsk-8'
     nettyVersion = '4.0.56.Final'
+    weupnpVersion = '0.1.4'
 }
 
 dependencies {
@@ -84,6 +85,7 @@ dependencies {
     compile "org.mapdb:mapdb:2.0-beta13"
     compile "co.rsk.bitcoinj:bitcoinj-thin:${bitcoinjVersion}"
     compile 'com.github.briandilley.jsonrpc4j:jsonrpc4j:1.5.1'
+    compile "org.bitlet:weupnp:${weupnpVersion}"
 
     runtime "org.slf4j:log4j-over-slf4j:${slf4jVersion}"
     runtime "ch.qos.logback:logback-classic:${logbackVersion}"
@@ -131,6 +133,7 @@ dependencyVerification {
         'net.jcip:jcip-annotations:be5805392060c71474bf6c9a67a099471274d30b83eef84bfc4e0889a4f1dcc0',
         'org.apache.commons:commons-lang3:8ac96fc686512d777fca85e144f196cd7cfe0c0aec23127229497d1a38ff651c',
         'org.awaitility:awaitility:a02982e89585a52c1c84296a895bfeb86ea250cca1a53bcfc8a14092fffa87c4',
+        'org.bitlet:weupnp:88df7e6504929d00bdb832863761385c68ab92af945b04f0770b126270a444fb',
         'org.bouncycastle:bclcrypto-jdk15on:7d03ba37df4d0ddc4ea40d56554324c6f18062a930edadb0a1b3acbbbea28efc',
         'org.ethereum:leveldbjni-all:18da00444c77080d4422b16c9d4750c4addabda350b702b4a6d628b86658e585',
         'org.fusesource.hawtjni:hawtjni-runtime:74fe9764e1fb1ef20b159dbca2d29abd6de292082ce3fcf538f81ac912390416',

rskj-core/src/main/java/co/rsk/RskContext.java

@@ -49,6 +49,7 @@
 import co.rsk.net.eth.WriterMessageRecorder;
 import co.rsk.net.sync.PeersInformation;
 import co.rsk.net.sync.SyncConfiguration;
+import co.rsk.net.discovery.upnp.UpnpService;
 import co.rsk.peg.BridgeSupportFactory;
 import co.rsk.peg.BtcBlockStoreWithCache;
 import co.rsk.peg.RepositoryBtcBlockStoreWithCache;
@@ -235,6 +236,7 @@ public class RskContext implements NodeBootstrapper {
     private StatusResolver statusResolver;
     private Web3InformationRetriever web3InformationRetriever;
     private BootstrapImporter bootstrapImporter;
+    private UpnpService upnpService;
 
     public RskContext(String[] args) {
         this(new CliArgs.Parser<>(
@@ -771,12 +773,11 @@ public List<InternalService> buildInternalServices() {
         if (rpcWebSocketEnabled) {
             internalServices.add(getWeb3WebSocketServer());
         }
+        if (getRskSystemProperties().isPeerDiscoveryByUpnpEnabled()) {
+            internalServices.add(getUpnpService());
+        }
         if (getRskSystemProperties().isPeerDiscoveryEnabled()) {
-            internalServices.add(new UDPServer(
-                    getRskSystemProperties().getBindAddress().getHostAddress(),
-                    getRskSystemProperties().getPeerPort(),
-                    getPeerExplorer()
-            ));
+            internalServices.add(getUDPServer());
         }
         if (getRskSystemProperties().isSyncEnabled()) {
             internalServices.add(getSyncPool());
@@ -1626,6 +1627,30 @@ private MinerClock getMinerClock() {
         return minerClock;
     }
 
+    private UDPServer getUDPServer() {
+        if (getRskSystemProperties().isPeerDiscoveryByUpnpEnabled()) {
+            return new UDPServer(
+                    getRskSystemProperties().getBindAddress().getHostAddress(),
+                    getRskSystemProperties().getPeerPort(),
+                    getPeerExplorer(),
+                    getUpnpService()
+            );
+        } else {
+            return new UDPServer(
+                    getRskSystemProperties().getBindAddress().getHostAddress(),
+                    getRskSystemProperties().getPeerPort(),
+                    getPeerExplorer()
+            );
+        }
+    }
+
+    private UpnpService getUpnpService() {
+        if (upnpService == null) {
+            upnpService = new UpnpService();
+        }
+        return upnpService;
+    }
+
     public org.ethereum.db.BlockStore buildBlockStore(String databaseDir) {
         File blockIndexDirectory = new File(databaseDir + "/blocks/");
         File dbFile = new File(blockIndexDirectory, "index");

rskj-core/src/main/java/co/rsk/net/discovery/UDPServer.java

@@ -19,6 +19,8 @@
 package co.rsk.net.discovery;
 
 import co.rsk.config.InternalService;
+import co.rsk.net.discovery.upnp.UpnpProtocol;
+import co.rsk.net.discovery.upnp.UpnpService;
 import io.netty.bootstrap.Bootstrap;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelInitializer;
@@ -35,6 +37,7 @@
  */
 public class UDPServer implements InternalService {
     private static final Logger logger = LoggerFactory.getLogger(UDPServer.class);
+    private static final String PEER_DISCOVERY_PORT_MAPPING_DESCRIPTION = "RSK peer discovery";
 
     private int port;
     private String address;
@@ -43,11 +46,17 @@ public class UDPServer implements InternalService {
     private volatile boolean shutdown = false;
 
     private PeerExplorer peerExplorer;
+    private UpnpService upnpService;
 
     public UDPServer(String address, int port, PeerExplorer peerExplorer) {
+        this(address, port, peerExplorer, null);
+    }
+
+    public UDPServer(String address, int port, PeerExplorer peerExplorer, UpnpService upnpService) {
         this.address = address;
         this.port = port;
         this.peerExplorer = peerExplorer;
+        this.upnpService = upnpService;
     }
 
     @Override
@@ -59,6 +68,7 @@ public void start() {
                 @Override
                 public void run() {
                     try {
+                        UDPServer.this.doPortMappingIfEnabled();
                         UDPServer.this.startUDPServer();
                     } catch (Exception e) {
                         logger.error("Discovery can't be started. ", e);
@@ -86,6 +96,18 @@ public void startUDPServer() throws InterruptedException {
         group.shutdownGracefully().sync();
     }
 
+    private void doPortMappingIfEnabled() {
+        if (upnpService != null) {
+            upnpService.findGateway(address)
+                    .ifPresent(gateway -> gateway.addPortMapping(
+                            port,
+                            port,
+                            UpnpProtocol.UDP,
+                            PEER_DISCOVERY_PORT_MAPPING_DESCRIPTION
+                    ));
+        }
+    }
+
     @Override
     public void stop()  {
         logger.info("Closing UDPListener...");

rskj-core/src/main/java/co/rsk/net/discovery/upnp/UpnpGatewayManager.java

@@ -0,0 +1,206 @@
+/*
+ * This file is part of RskJ
+ * Copyright (C) 2019 RSK Labs Ltd.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package co.rsk.net.discovery.upnp;
+
+import org.bitlet.weupnp.GatewayDevice;
+import org.bitlet.weupnp.PortMappingEntry;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.ListIterator;
+import java.util.Optional;
+
+/**
+ * Provides a UPnP interface for a particular Internet Gateway Device:
+ * <ul>
+ *     <li>Add/remove port mappings.</li>
+ *     <li>Find the gateway's external IP address.</li>
+ * </ul>
+ */
+public class UpnpGatewayManager {
+
+    private static final Logger logger = LoggerFactory.getLogger(UpnpGatewayManager.class);
+    private static final int PORT_MAPPINGS_INITIAL_CAPACITY = 3;
+
+    private final GatewayDevice gateway;
+    private final List<PortMappingEntry> portMappings = new ArrayList<>(PORT_MAPPINGS_INITIAL_CAPACITY);
+
+    /**
+     * Package-private constructor.  Called by {@link UpnpService#findGateway()}.
+     *
+     * @param gateway a valid gateway with a WAN connection.
+     */
+    UpnpGatewayManager(GatewayDevice gateway) {
+        this.gateway = gateway;
+    }
+
+    /**
+     * Gets the external IP address of the gateway.
+     *
+     * @return the external IP address of the gateway, or empty if failure.
+     */
+    public Optional<String> getExternalIPAddress() {
+        try {
+            return Optional.ofNullable(gateway.getExternalIPAddress());
+        } catch (Exception e) {
+            logger.error("Failed to get external IP address.", e);
+            return Optional.empty();
+        }
+    }
+
+    /**
+     * Forwards a port on the gateway to this node.  The port mapping will be deleted
+     * on {@link UpnpService#stop()}.
+     *
+     * @param externalPort the external port to be forwarded.
+     * @param internalPort the destination port being forwarded to.
+     * @param protocol     the protocol to use.
+     * @param description  describes the purpose of this port mapping.
+     * @return true if successful.
+     */
+    public synchronized boolean addPortMapping(int externalPort, int internalPort, UpnpProtocol protocol, String description) {
+        String strProtocol = protocol.toString();
+        String strLocalAddress = gateway.getLocalAddress().getHostAddress();
+
+        if (addPortMapping(externalPort, internalPort, strLocalAddress, strProtocol, description)) {
+            logger.info(
+                    "Added port mapping of {} port {} to {}:{} for \"{}\".",
+                    strProtocol,
+                    externalPort,
+                    strLocalAddress,
+                    internalPort,
+                    description
+            );
+            // saved here for release on service shutdown
+            portMappings.add(createPortMappingEntryObject(
+                    strProtocol,
+                    externalPort,
+                    strLocalAddress,
+                    internalPort,
+                    description
+            ));
+            return true;
+        } else {
+            logger.error(getPortForwardingExceptionMessage(
+                    strProtocol,
+                    externalPort,
+                    strLocalAddress,
+                    internalPort,
+                    description
+            ));
+            return false;
+        }
+    }
+
+    private boolean addPortMapping(
+            int externalPort,
+            int internalPort,
+            String strLocalAddress,
+            String strProtocol,
+            String description) {
+
+        try {
+            return gateway.addPortMapping(
+                    externalPort,
+                    internalPort,
+                    strLocalAddress,
+                    strProtocol,
+                    description
+            );
+        } catch (Exception e) {
+            logger.error(getPortForwardingExceptionMessage(
+                    strProtocol,
+                    externalPort,
+                    strLocalAddress,
+                    internalPort,
+                    description
+            ), e);
+            return false;
+        }
+    }
+
+    private static PortMappingEntry createPortMappingEntryObject(
+            String protocol,
+            int externalPort,
+            String localAddress,
+            int internalPort,
+            String description) {
+
+        PortMappingEntry pm = new PortMappingEntry();
+        pm.setProtocol(protocol);
+        pm.setExternalPort(externalPort);
+        pm.setInternalClient(localAddress);
+        pm.setInternalPort(internalPort);
+        pm.setPortMappingDescription(description);
+        return pm;
+    }
+
+    private static String getPortForwardingExceptionMessage(
+            String strProtocol,
+            int externalPort,
+            String strLocalAddress,
+            int internalPort,
+            String description) {
+        return String.format(
+                "Failed to forward %s port %s to %s:%s for %s.",
+                strProtocol,
+                externalPort,
+                strLocalAddress,
+                internalPort,
+                description
+        );
+    }
+
+    /**
+     * Deletes all port mappings which were created by calls to
+     * {@link #addPortMapping(int, int, UpnpProtocol, String)}.
+     */
+    public synchronized void deleteAllPortMappings() {
+        ListIterator<PortMappingEntry> iter = portMappings.listIterator();
+        while (iter.hasNext()) {
+            PortMappingEntry entry = iter.next();
+            int externalPort = entry.getExternalPort();
+            String protocol = entry.getProtocol();
+
+            if (deletePortMapping(externalPort, protocol)) {
+                logger.info(
+                        "Deleted port mapping of {} port {}.",
+                        protocol,
+                        externalPort
+                );
+                iter.remove();
+            }
+        }
+    }
+
+    private boolean deletePortMapping(int externalPort, String protocol) {
+        try {
+            return gateway.deletePortMapping(externalPort, protocol);
+        } catch (Exception e) {
+            logger.error(String.format(
+                    "Failed to delete port mapping of %s port %s",
+                    protocol,
+                    externalPort
+            ), e);
+            return false;
+        }
+    }
+}

rskj-core/src/main/java/co/rsk/net/discovery/upnp/UpnpProtocol.java

@@ -0,0 +1,23 @@
+/*
+ * This file is part of RskJ
+ * Copyright (C) 2019 RSK Labs Ltd.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package co.rsk.net.discovery.upnp;
+
+public enum UpnpProtocol {
+    TCP, UDP
+}