Add method for plugins to get remote properties.

bramble-api/src/main/java/org/briarproject/bramble/api/plugin/PluginCallback.java

@@ -8,6 +8,8 @@ import org.briarproject.bramble.api.plugin.event.TransportStateEvent;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.settings.Settings;
 
+import java.util.Collection;
+
 /**
  * An interface through which a transport plugin interacts with the rest of
  * the application.
@@ -25,6 +27,11 @@ public interface PluginCallback extends ConnectionHandler {
 	 */
 	TransportProperties getLocalProperties();
 
+	/**
+	 * Returns the plugin's remote transport properties.
+	 */
+	Collection<TransportProperties> getRemoteProperties();
+
 	/**
 	 * Merges the given settings with the plugin's settings
 	 */

bramble-core/src/main/java/org/briarproject/bramble/plugin/PluginManagerImpl.java

@@ -1,6 +1,7 @@
 package org.briarproject.bramble.plugin;
 
 import org.briarproject.bramble.api.connection.ConnectionManager;
+import org.briarproject.bramble.api.contact.ContactId;
 import org.briarproject.bramble.api.db.DbException;
 import org.briarproject.bramble.api.event.EventBus;
 import org.briarproject.bramble.api.lifecycle.IoExecutor;
@@ -44,6 +45,7 @@ import java.util.logging.Logger;
 import javax.annotation.concurrent.ThreadSafe;
 import javax.inject.Inject;
 
+import static java.util.Collections.emptyList;
 import static java.util.logging.Level.FINE;
 import static java.util.logging.Level.INFO;
 import static java.util.logging.Level.WARNING;
@@ -303,6 +305,18 @@ class PluginManagerImpl implements PluginManager, Service {
 			}
 		}
 
+		@Override
+		public Collection<TransportProperties> getRemoteProperties() {
+			try {
+				Map<ContactId, TransportProperties> remote =
+						transportPropertyManager.getRemoteProperties(id);
+				return remote.values();
+			} catch (DbException e) {
+				logException(LOG, WARNING, e);
+				return emptyList();
+			}
+		}
+
 		@Override
 		public void mergeSettings(Settings s) {
 			PluginManagerImpl.this.mergeSettings(s, id.getString());

bramble-core/src/test/java/org/briarproject/bramble/plugin/tcp/LanTcpPluginTest.java

@@ -22,11 +22,13 @@ import java.net.InetSocketAddress;
 import java.net.NetworkInterface;
 import java.net.ServerSocket;
 import java.net.Socket;
+import java.util.Collection;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 import static java.net.NetworkInterface.getNetworkInterfaces;
+import static java.util.Collections.emptyList;
 import static java.util.Collections.list;
 import static java.util.concurrent.Executors.newCachedThreadPool;
 import static java.util.concurrent.TimeUnit.SECONDS;
@@ -320,6 +322,11 @@ public class LanTcpPluginTest extends BrambleTestCase {
 			return local;
 		}
 
+		@Override
+		public Collection<TransportProperties> getRemoteProperties() {
+			return emptyList();
+		}
+
 		@Override
 		public void mergeSettings(Settings s) {
 		}

bramble-java/src/test/java/org/briarproject/bramble/plugin/tor/TestPluginCallback.java

@@ -9,6 +9,10 @@ import org.briarproject.bramble.api.plugin.duplex.DuplexTransportConnection;
 import org.briarproject.bramble.api.properties.TransportProperties;
 import org.briarproject.bramble.api.settings.Settings;
 
+import java.util.Collection;
+
+import static java.util.Collections.emptyList;
+
 @NotNullByDefault
 public class TestPluginCallback implements PluginCallback {
 
@@ -22,6 +26,11 @@ public class TestPluginCallback implements PluginCallback {
 		return new TransportProperties();
 	}
 
+	@Override
+	public Collection<TransportProperties> getRemoteProperties() {
+		return emptyList();
+	}
+
 	@Override
 	public void mergeSettings(Settings s) {
 	}