Tunnel control now lets you easily create client and server tunnels

README.md

@@ -63,3 +63,23 @@ Press Ctrl-C to gracefully shut down the router (or send the SIGINT signal to th
 ## Check that the I2P router is running and that it is listening for SAM connections
 
 `fuser 7656/tcp`
+
+
+## Tunnel control
+
+Listen for i2p connections and forward them to the specified host and port. Returns a newly created destination public key.
+`dist/linux/router/bin/tunnel-control.sh server.create <host> <port>`
+
+// Close the tunnel listening for connections on the specified port. Returns "OK".
+`dist/linux/router/bin/tunnel-control.sh server.destroy <i2p destination public key>`
+
+Create a tunnel that listens for connections on localhost and forwards connections over I2P to the specified destination public key. Returns a newly created localhost port number.
+`dist/linux/router/bin/tunnel-control.sh client.create <i2p destination public key>`
+
+Close the tunnel listening for connections on the specified port. Returns "OK".
+`dist/linux/router/bin/tunnel-control.sh client.destroy <port>`
+
+
+## Watch the I2P log for messages
+
+`tail -f dist/linux/router/i2p.config/wrapper.log`

bin/build-all.sh

@@ -8,6 +8,9 @@ $basedir/bin/import-packages.sh
 # build the i2p project retrieved from the I2P repository
 $basedir/bin/build-original-i2p.sh
 
-# convert the imported JARs to modules, compile the Java source code in this project, and then use the jlink tool
+# convert the jar files from an existing I2P build into modules suitable for use with jlink
+$basedir/bin/convert-jars-to-modules.sh
+
+# compile the Java source code in this project, and then use the jlink tool
 # to build a zero-dependency platform-specific launcher
 $basedir/bin/build-launcher.sh

bin/build-launcher.sh

@@ -4,9 +4,6 @@ basedir=$(dirname $(dirname $(readlink -fm $0)))
 
 source $basedir/bin/java-config.sh
 
-# convert the jar files from an existing I2P build into modules suitable for use with jlink
-$basedir/bin/convert-jars-to-modules.sh
-
 # compile the Main class that starts the I2P router and SAM listener
 echo "*** Compiling Main class"
 $JAVA_HOME/bin/javac --module-path import/lib -d target/classes $(find src -name '*.java')
@@ -29,8 +26,10 @@ echo "*** Performing jlink (Windows)"
 $JAVA_HOME/bin/jlink --module-path $basedir/import/jdks/win/jdk-${JDK_VERSION}/jmods:target/modules:target/org.getmonero.i2p.embedded.jar --add-modules org.getmonero.i2p.embedded --output dist/win/router --strip-debug --compress 2 --no-header-files --no-man-pages
 
 
-cp $basedir/resources/launch.sh $basedir/dist/linux/router/bin/
-cp $basedir/resources/launch.sh $basedir/dist/mac/router/bin/
+for i in linux mac; do
+  cp $basedir/resources/launch.sh $basedir/dist/$i/router/bin/
+  cp $basedir/resources/tunnel-control.sh $basedir/dist/$i/router/bin/
+done
 cp $basedir/resources/launch.bat $basedir/dist/win/router/bin/
 
 for i in linux mac win; do cp -r $basedir/import/i2p.base $basedir/dist/$i/router/; done

bin/build-original-i2p.sh

@@ -16,7 +16,7 @@ cd ..
 # copy the jars that we're going to modularize
 rm -fr $basedir/import/lib
 mkdir -p $basedir/import/lib
-for i in i2p.jar mstreaming.jar router.jar sam.jar streaming.jar; do cp $basedir/import/i2p.i2p/build/$i $basedir/import/lib/; done
+for i in i2ptunnel.jar i2p.jar mstreaming.jar router.jar sam.jar streaming.jar; do cp $basedir/import/i2p.i2p/build/$i $basedir/import/lib/; done
 
 # build a minimal i2p.base dir
 rm -fr $basedir/import/i2p.base

resources/tunnel-control.sh

@@ -0,0 +1,3 @@
+#!/bin/bash
+
+exec 3<>/dev/tcp/localhost/30000; echo "$1 $2 $3" >&3; cat <&3

src/module-info.java

@@ -4,5 +4,6 @@ module org.getmonero.i2p.embedded {
   requires streaming;
   requires router;
   requires sam;
+  requires i2ptunnel;
   requires jdk.crypto.ec;
 }

src/org/getmonero/i2p/embedded/Main.java

@@ -71,6 +71,9 @@ public class Main {
           ClientAppManager mgr = new ClientAppManagerImpl(context);
           SAMBridge samBridge = new SAMBridge(context, mgr, args);
           samBridge.startup();
+
+          new Thread(new TunnelControl(new File(new File(p.getProperty("i2p.dir.config")), "tunnel"))).start();
+
         }
         catch (Exception e) {
           e.printStackTrace();

src/org/getmonero/i2p/embedded/TunnelControl.java

@@ -0,0 +1,114 @@
+package org.getmonero.i2p.embedded;
+
+import net.i2p.data.Base64;
+import net.i2p.i2ptunnel.I2PTunnel;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.InputStreamReader;
+import java.io.PrintWriter;
+import java.net.InetAddress;
+import java.net.ServerSocket;
+import java.nio.file.Files;
+import java.util.HashMap;
+import java.util.Map;
+
+public class TunnelControl implements Runnable {
+
+  private Map<Integer, I2PTunnel> clientTunnels = new HashMap<>();
+  private Map<String, I2PTunnel> serverTunnels = new HashMap<>();
+  private int clientPortSeq = 30000;
+  private int serverSeq = 0;
+  private String tunnelConfigDirPrefix;
+  public TunnelControl(File tunnelConfigDir) {
+    tunnelConfigDir.delete();
+    tunnelConfigDir.mkdir();
+    this.tunnelConfigDirPrefix = tunnelConfigDir.getAbsolutePath() + File.separator;
+  }
+
+  @Override
+  public void run() {
+
+    // listen for socket connections to the tunnel controller.
+    // listen for the commands on port 30000:
+    // server.create <host> <port> // returns a newly created destination public key, which will listen for i2p connections and forward them to the specified host and port
+    // server.destroy <i2p destination public key> // closes the tunnel listening for connections on the specified port, and returns OK
+    // client.create <i2p destination public key> // returns a newly created localhost port number, where connections will be sent over I2P to the destination public key
+    // client.destroy <port> // closes the tunnel listening for connections on the specified port, and returns OK
+    //
+    // send a command with bash: exec 3<>/dev/tcp/localhost/30000; echo "server.create localhost 80" >&3; cat <&3
+    //
+    try (var listener = new ServerSocket(clientPortSeq++, 0, InetAddress.getLoopbackAddress())) {
+      while (true) {
+        try (var socket = listener.accept()) {
+          var out = new PrintWriter(socket.getOutputStream(), true);
+          var in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
+
+          var args = in.readLine().split(" ");
+          if(args[0].equals("server.create")) {
+            String destHost = args[1];
+            String destPort = args[2];
+            String seckeyPath = tunnelConfigDirPrefix + "seckey."+serverSeq+".dat";
+            String pubkeyPath = tunnelConfigDirPrefix + "pubkey."+serverSeq+".dat";
+            serverSeq++;
+            new I2PTunnel(new String[]{"-die", "-nocli", "-e", "genkeys " + seckeyPath + " " + pubkeyPath});
+            String destPubKey = Base64.encode(Files.readAllBytes(new File(pubkeyPath).toPath()));
+
+            // listen using the I2P server keypair, and forward incoming connections to a destination and port
+            new Thread() {
+              @Override
+              public void run() {
+                I2PTunnel t = new I2PTunnel(new String[]{"-die", "-nocli", "-e", "server "+destHost+" "+destPort+" " + seckeyPath});
+                serverTunnels.put(destPubKey, t);
+              }
+            }.start();
+            out.println(destPubKey);
+          }
+          else if(args[0].equals("server.destroy")) {
+            String destPubKey = args[1];
+            new Thread() {
+              @Override
+              public void run() {
+                var t = serverTunnels.get(destPubKey);
+                serverTunnels.remove(destPubKey);
+                t.runClose(new String[]{"forced", "all"}, t);
+              }
+            }.start();
+            out.println("OK");
+          }
+          else if(args[0].equals("client.create")) {
+            String destPubKey = args[1];
+            int port = clientPortSeq++;
+            new Thread() {
+              @Override
+              public void run() {
+                var t = new I2PTunnel(new String[]{"-die", "-nocli", "-e", "config localhost 7654", "-e", "client " + port + " " + destPubKey});
+                clientTunnels.put(port, t);
+              }
+            }.start();
+            out.println(port);
+          }
+          if(args[0].equals("client.destroy")) {
+            int port = Integer.parseInt(args[1]);
+            new Thread() {
+              @Override
+              public void run() {
+                var t = clientTunnels.get(port);
+                clientTunnels.remove(port);
+                t.runClose(new String[]{"forced", "all"}, t);
+              }
+            }.start();
+            out.println("OK");
+          }
+        }
+        catch (Exception e) {
+          e.printStackTrace();
+        }
+      }
+    }
+    catch (Exception e) {
+      e.printStackTrace();
+    }
+
+  }
+}