WIP: add bgp-java

Add bgp-java.
Update peer list based on TunnelEncapsAttribute in BGP.

11 files changed, 444 insertions, 25 deletions

diff --git a/settings.gradle b/settings.gradle
index 2a030305..c5d41a3b 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -25,4 +25,5 @@ dependencyResolutionManagement {
 rootProject.name = "wireguard-android"
 
 include ':tunnel'
+include ':bgp-java'
 include ':ui'
diff --git a/tunnel/build.gradle b/tunnel/build.gradle
index 8937ca6b..a0ea31ae 100644
--- a/tunnel/build.gradle
+++ b/tunnel/build.gradle
@@ -68,6 +68,7 @@ android {
 }
 
 dependencies {
+    implementation project(":bgp-java")
     implementation "androidx.annotation:annotation:$annotationsVersion"
     implementation "androidx.collection:collection:$collectionVersion"
     implementation "io.grpc:grpc-okhttp:$grpcVersion"
diff --git a/tunnel/src/main/java/com/wireguard/android/backend/Bgp.java b/tunnel/src/main/java/com/wireguard/android/backend/Bgp.java
new file mode 100644
index 00000000..12668621
--- /dev/null
+++ b/tunnel/src/main/java/com/wireguard/android/backend/Bgp.java
@@ -0,0 +1,281 @@
+/*
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package com.wireguard.android.backend;
+
+import android.net.TrafficStats;
+import android.util.Log;
+
+import com.lumaserv.bgp.BGPListener;
+import com.lumaserv.bgp.BGPServer;
+import com.lumaserv.bgp.BGPSession;
+import com.lumaserv.bgp.BGPSessionConfiguration;
+import com.lumaserv.bgp.protocol.AFI;
+import com.lumaserv.bgp.protocol.BGPPacket;
+import com.lumaserv.bgp.protocol.IPPrefix;
+import com.lumaserv.bgp.protocol.SAFI;
+import com.lumaserv.bgp.protocol.attribute.ASPathAttribute;
+import com.lumaserv.bgp.protocol.attribute.MPReachableNLRIAttribute;
+import com.lumaserv.bgp.protocol.attribute.NextHopAttribute;
+import com.lumaserv.bgp.protocol.attribute.OriginAttribute;
+import com.lumaserv.bgp.protocol.attribute.PathAttribute;
+import com.lumaserv.bgp.protocol.attribute.TunnelEncapsAttribute;
+import com.lumaserv.bgp.protocol.message.BGPUpdate;
+
+import com.wireguard.config.InetEndpoint;
+import com.wireguard.config.InetNetwork;
+import com.wireguard.crypto.Key;
+import com.wireguard.crypto.KeyFormatException;
+
+import io.grpc.ManagedChannel;
+
+import java.io.IOException;
+import java.net.Inet4Address;
+import java.net.InetAddress;
+import java.net.ServerSocket;
+import java.net.Socket;
+import java.net.SocketException;
+import java.net.UnknownHostException;
+import java.util.ArrayList;
+import java.util.List;
+
+import javax.net.SocketFactory;
+
+public class Bgp implements BGPListener {
+    private static final String TAG = "WireGuard/Bgp";
+    private static final String SESSION = "demosession";
+    private static final int MY_ASN = (int)4200000201L;
+    private static final int REMOTE_ASN = (int)4200000010L;
+    private static final String REMOTE_ADDR = "10.49.32.1";
+    private static final String REMOTE_ID = "10.49.160.1";
+    private static final String LOCAL_ID = "10.49.33.218";
+    private static final int PORT = 0;
+    private static final int STATS_TAG = 1; // FIXME
+
+    private ManagedChannel channel;
+    private Tunnel tunnel;
+    private int tunnelHandle;
+    private BGPServer server;
+
+    public Bgp(ManagedChannel channel, Tunnel tunnel, int tunnelHandle) {
+	this.channel = channel;
+	this.tunnel = tunnel;
+	this.tunnelHandle = tunnelHandle;
+    }
+
+    @Override
+    public void onOpen(BGPSession session) {
+	// DO WHAT YOU WANT
+	Log.i(TAG, "onOpen");
+
+	// BGPUpdate update;
+	// {
+	//     List<IPPrefix> prefixes = new ArrayList<>(1);
+	//     prefixes.add(new IPPrefix(new byte[]{10, 49, 124, 105}, 32));
+	//     List<PathAttribute> attrs = new ArrayList<>();
+	//     attrs.add(new OriginAttribute(OriginAttribute.Origin.IGP));
+	//     attrs.add(new NextHopAttribute().setAddress(new byte[]{10, 49, 125, 105}));
+	//     ASPathAttribute.Segment seg = new ASPathAttribute.Segment();
+	//     seg.setType(ASPathAttribute.Segment.Type.SEQUENCE);
+	//     seg.getAsns().add(MY_ASN);
+	//     ASPathAttribute asPath = new ASPathAttribute(session);
+	//     asPath.getSegments().add(seg);
+	//     attrs.add(asPath);
+	//     update = new BGPUpdate().setAttributes(attrs).setPrefixes(prefixes);
+	// }
+
+	// BGPUpdate update2;
+	// try {
+	//     List<PathAttribute> attrs = new ArrayList<>();
+	//     attrs.add(new OriginAttribute(OriginAttribute.Origin.IGP));
+	//     ASPathAttribute.Segment seg = new ASPathAttribute.Segment();
+	//     seg.setType(ASPathAttribute.Segment.Type.SEQUENCE);
+	//     seg.getAsns().add(MY_ASN);
+	//     ASPathAttribute asPath = new ASPathAttribute(session);
+	//     List<IPPrefix> prefixes = new ArrayList<>(1);
+	//     prefixes.add(new IPPrefix(new byte[]{0x20, 0x1, 0x04, 0x70, (byte)0xdf, (byte)0xae, 0x63, 0, 0, 0, 0, 0, 0, 0, 0x01, 0x05}, 128));
+	//     MPReachableNLRIAttribute mpr = new MPReachableNLRIAttribute();
+	//     mpr.setAfi(AFI.IPV6).setSafi(SAFI.UNICAST).setNextHop(InetAddress.getByName("2001:470:dfae:6300::1:105")).setNlriPrefixes(prefixes);
+	//     attrs.add(mpr);
+	//     asPath.getSegments().add(seg);
+	//     attrs.add(asPath);
+	//     update2 = new BGPUpdate().setAttributes(attrs);
+	// } catch (UnknownHostException ex) {
+	//     throw new RuntimeException(ex);
+	// }
+
+	// try {
+	//     session.sendUpdate(update);
+	//     session.sendUpdate(update2);
+	// } catch (IOException ex) {
+	//     throw new RuntimeException(ex);
+	// }
+    }
+
+    @Override
+    public void onUpdate(BGPSession session, BGPUpdate update) {
+	// DO WHAT YOU WANT
+	Log.i(TAG, "onUpdate: " + update.getPrefixes() + ",-" + update.getWithdrawnPrefixes() + "," + update.getAttributes());
+	MPReachableNLRIAttribute mpr = null;
+	TunnelEncapsAttribute te = null;
+
+	for (PathAttribute attr: update.getAttributes()) {
+	    if (attr instanceof TunnelEncapsAttribute) {
+		te = (TunnelEncapsAttribute)attr;
+	    } else if (attr instanceof MPReachableNLRIAttribute) {
+		mpr = (MPReachableNLRIAttribute)attr;
+	    }
+	}
+
+	if (te == null) {
+	    return;
+	}
+
+	TunnelEncapsAttribute.WireGuard wg = null;
+	TunnelEncapsAttribute.Color col = null;
+	TunnelEncapsAttribute.EgressEndpoint ep = null;
+	TunnelEncapsAttribute.UDPDestinationPort port = null;
+
+	for (TunnelEncapsAttribute.Tunnel t: te.getTunnels()) {
+	    if (t.getType() != 51820) {
+		continue;
+	    }
+
+	    for (TunnelEncapsAttribute.SubTlv st: t.getSubTlvs()) {
+		if (st instanceof TunnelEncapsAttribute.WireGuard) {
+		    wg = (TunnelEncapsAttribute.WireGuard)st;
+		} else if (st instanceof TunnelEncapsAttribute.Color) {
+		    col = (TunnelEncapsAttribute.Color)st;
+		} else if (st instanceof TunnelEncapsAttribute.EgressEndpoint) {
+		    ep = (TunnelEncapsAttribute.EgressEndpoint)st;
+		} else if (st instanceof TunnelEncapsAttribute.UDPDestinationPort) {
+		    port = (TunnelEncapsAttribute.UDPDestinationPort)st;
+		}
+	    }
+	}
+
+	if (wg == null) {
+	    return;
+	}
+
+	try {
+	    Key publicKey = Key.fromBytes(wg.getPublicKey());
+	    InetEndpoint endpoint = null;
+
+	    if (ep != null && port != null) {
+		endpoint = InetEndpoint.fromAddress(ep.getAddress(), port.getPort());
+	    }
+
+	    tunnel.onEndpointChange(publicKey, endpoint);
+
+	    List<InetNetwork> addNetworks = new ArrayList<>();
+	    List<InetNetwork> removeNetworks = new ArrayList<>();
+
+	    for (IPPrefix prefix: update.getPrefixes()) {
+		try {
+		    addNetworks.add(new InetNetwork(InetAddress.getByAddress(prefix.getAddress()), prefix.getLength()));
+		} catch (UnknownHostException ignore) {
+		}
+	    }
+
+	    for (IPPrefix prefix: update.getWithdrawnPrefixes()) {
+		try {
+		    removeNetworks.add(new InetNetwork(InetAddress.getByAddress(prefix.getAddress()), prefix.getLength()));
+		} catch (UnknownHostException ignore) {
+		}
+	    }
+
+	    if (mpr != null && (mpr.getAfi() == AFI.IPV6 || mpr.getAfi() == AFI.IPV4) && mpr.getSafi() == SAFI.UNICAST) {
+		for (IPPrefix prefix: mpr.getNlriPrefixes()) {
+		    try {
+			addNetworks.add(new InetNetwork(InetAddress.getByAddress(prefix.getAddress()), prefix.getLength()));
+		    } catch (UnknownHostException ignore) {
+		    }
+		}
+	    }
+
+	    tunnel.onAllowedIpsChange(publicKey, addNetworks, removeNetworks);
+
+	} catch (KeyFormatException ex) {
+	    Log.w(TAG, "Key.fromBytes " + ex);
+	}
+    }
+
+    @Override
+    public void onClose(BGPSession session) {
+	// NOT YET IMPLEMENTED
+	Log.i(TAG, "onClose");
+    }
+
+    public boolean startServer() {
+	stopServer();
+	try {
+	    SocketFactory factory = new SocketFactory() {
+		    private Socket taggedSocket(Socket sock) throws SocketException {
+			TrafficStats.tagSocket(sock);
+			return sock;
+		    }
+
+		    @Override
+		    public Socket createSocket(String host, int port) throws IOException {
+			TrafficStats.setThreadStatsTag(STATS_TAG);
+			return taggedSocket(new Socket(host, port));
+		    }
+
+		    @Override
+		    public Socket createSocket(InetAddress host, int port) throws IOException {
+			TrafficStats.setThreadStatsTag(STATS_TAG);
+			return taggedSocket(new Socket(host, port));
+		    }
+
+		    @Override
+		    public Socket createSocket(InetAddress address, int port, InetAddress localAddress, int localPort) throws IOException {
+			TrafficStats.setThreadStatsTag(STATS_TAG);
+			return taggedSocket(new Socket(address, port, localAddress, localPort));
+		    }
+
+		    @Override
+		    public Socket createSocket(String host, int port, InetAddress localHost, int localPort) throws IOException {
+			TrafficStats.setThreadStatsTag(STATS_TAG);
+			return taggedSocket(new Socket(host, port, localHost, localPort));
+		    }
+		};
+
+	    BGPSessionConfiguration config =
+		new BGPSessionConfiguration(SESSION,
+					    MY_ASN,
+					    ip(LOCAL_ID),
+					    REMOTE_ASN,
+					    ip(REMOTE_ID),
+					    null, // Remote address
+					    factory,
+					    this);
+	    TrafficStats.setThreadStatsTag(STATS_TAG);
+	    ServerSocket socket = new ServerSocket(PORT);
+	    //TrafficStats.tagSocket(socket);
+	    // Set
+	    server = new BGPServer(socket);
+	    server.getSessionConfigurations().add(config);
+	    server.connect(config, REMOTE_ADDR);
+	    return true;
+	} catch (IOException ex) {
+	    return false;
+	}
+    }
+
+    public void stopServer() {
+	if (server != null) {
+	    server.shutdown();
+	    server = null;
+	}
+    }
+
+    private static byte[] ip(String s) throws UnknownHostException {
+	InetAddress addr = InetAddress.getByName(s);
+	byte[] data = addr.getAddress();
+	if (data.length != 4)
+	    throw new UnknownHostException(s + ": Not an IPv4 address");
+	return data;
+    }
+}
diff --git a/tunnel/src/main/java/com/wireguard/android/backend/GoBackend.java b/tunnel/src/main/java/com/wireguard/android/backend/GoBackend.java
index 5a4dfc1e..860e2369 100644
--- a/tunnel/src/main/java/com/wireguard/android/backend/GoBackend.java
+++ b/tunnel/src/main/java/com/wireguard/android/backend/GoBackend.java
@@ -114,6 +114,7 @@ public final class GoBackend implements Backend {
     private ConnectivityManager.NetworkCallback vpnNetworkCallback;
     @Nullable private Network activeNetwork;
     private boolean obtainDhcpLease = false;
+    @Nullable private Bgp bgp;
 
     /**
      * Public constructor for GoBackend.
@@ -435,6 +436,10 @@ public final class GoBackend implements Backend {
         service.protect(wgGetSocketV4(currentTunnelHandle));
         service.protect(wgGetSocketV6(currentTunnelHandle));
         Log.i(TAG, "Dhcp done");
+
+        bgp = new Bgp(channel, currentTunnel, currentTunnelHandle);
+        bgp.startServer();
+
         currentTunnel.onDhcpChange(dhcp);
     }
 
@@ -714,6 +719,10 @@ public final class GoBackend implements Backend {
             currentTunnel = null;
             currentTunnelHandle = -1;
             currentConfig = null;
+            if (bgp != null) {
+                bgp.stopServer();
+                bgp = null;
+            }
             stopHttpProxy();
             if (vpnNetworkCallback != null)
                 connectivityManager.unregisterNetworkCallback(vpnNetworkCallback);
@@ -782,6 +791,10 @@ public final class GoBackend implements Backend {
         @Override
         public void onDestroy() {
             if (owner != null) {
+                if (owner.bgp != null) {
+                    owner.bgp.stopServer();
+                    owner.bgp = null;
+                }
                 owner.stopHttpProxy();
                 final Tunnel tunnel = owner.currentTunnel;
                 if (tunnel != null) {
diff --git a/tunnel/src/main/java/com/wireguard/android/backend/Tunnel.java b/tunnel/src/main/java/com/wireguard/android/backend/Tunnel.java
index a2342807..4c435ca7 100644
--- a/tunnel/src/main/java/com/wireguard/android/backend/Tunnel.java
+++ b/tunnel/src/main/java/com/wireguard/android/backend/Tunnel.java
@@ -8,9 +8,11 @@ package com.wireguard.android.backend;
 import androidx.annotation.Nullable;
 
 import com.wireguard.config.InetEndpoint;
+import com.wireguard.config.InetNetwork;
 import com.wireguard.crypto.Key;
 import com.wireguard.util.NonNullForAll;
 
+import java.util.List;
 import java.util.regex.Pattern;
 
 /**
@@ -66,5 +68,7 @@ public interface Tunnel {
      */
     void onDhcpChange(Dhcp newDhcp);
 
-    void onEndpointChange(@Nullable Key publicKey, @Nullable InetEndpoint newEndpoint);
+    void onEndpointChange(Key publicKey, @Nullable InetEndpoint newEndpoint);
+
+    void onAllowedIpsChange(Key publicKey, @Nullable List<InetNetwork> addNetworks, @Nullable List<InetNetwork> removeNetworks);
 }
diff --git a/tunnel/src/main/java/com/wireguard/config/InetEndpoint.java b/tunnel/src/main/java/com/wireguard/config/InetEndpoint.java
index 290195e4..62ac0152 100644
--- a/tunnel/src/main/java/com/wireguard/config/InetEndpoint.java
+++ b/tunnel/src/main/java/com/wireguard/config/InetEndpoint.java
@@ -65,6 +65,10 @@ public final class InetEndpoint {
         }
     }
 
+    public static InetEndpoint fromAddress(final InetAddress address, final int port) {
+        return new InetEndpoint(address.getHostAddress(), true, port);
+    }
+
     @Override
     public boolean equals(final Object obj) {
         if (!(obj instanceof InetEndpoint))
@@ -82,7 +86,11 @@ public final class InetEndpoint {
     }
 
     public Optional<InetEndpoint> getResolved() {
-        return Optional.ofNullable(resolved);
+        if (isResolved) {
+            return Optional.of(this);
+        } else {
+            return Optional.ofNullable(resolved);
+        }
     }
 
     /**
diff --git a/ui/src/main/java/com/wireguard/android/fragment/TunnelDetailFragment.kt b/ui/src/main/java/com/wireguard/android/fragment/TunnelDetailFragment.kt
index ed49d56d..50d43690 100644
--- a/ui/src/main/java/com/wireguard/android/fragment/TunnelDetailFragment.kt
+++ b/ui/src/main/java/com/wireguard/android/fragment/TunnelDetailFragment.kt
@@ -112,7 +112,7 @@ class TunnelDetailFragment : BaseFragment() {
             for (i in 0 until binding.peersLayout.childCount) {
                 val peer: TunnelDetailPeerBinding = DataBindingUtil.getBinding(binding.peersLayout.getChildAt(i))
                         ?: continue
-                val publicKey = peer.item!!.peer.publicKey
+                val publicKey = peer.item!!.publicKey
                 val rx = statistics.peerRx(publicKey)
                 val tx = statistics.peerTx(publicKey)
                 if (rx == 0L && tx == 0L) {
diff --git a/ui/src/main/java/com/wireguard/android/model/ObservableTunnel.kt b/ui/src/main/java/com/wireguard/android/model/ObservableTunnel.kt
index ef22f846..9684ffab 100644
--- a/ui/src/main/java/com/wireguard/android/model/ObservableTunnel.kt
+++ b/ui/src/main/java/com/wireguard/android/model/ObservableTunnel.kt
@@ -7,6 +7,7 @@ package com.wireguard.android.model
 import android.util.Log
 import androidx.databinding.BaseObservable
 import androidx.databinding.Bindable
+import com.wireguard.android.Application
 import com.wireguard.android.BR
 import com.wireguard.android.backend.Dhcp
 import com.wireguard.android.backend.Statistics
@@ -14,10 +15,12 @@ import com.wireguard.android.backend.Tunnel
 import com.wireguard.android.databinding.Keyed
 import com.wireguard.android.util.applicationScope
 import com.wireguard.android.viewmodel.ConfigDetail
+import com.wireguard.android.viewmodel.PeerDetail
 import com.wireguard.config.Config
 import com.wireguard.config.InetEndpoint
-import com.wireguard.crypto.Key;
-import java.util.Optional;
+import com.wireguard.config.InetNetwork
+import com.wireguard.crypto.Key
+import java.util.Optional
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
@@ -63,10 +66,12 @@ class ObservableTunnel internal constructor(
         if (state != Tunnel.State.UP) {
             onStatisticsChanged(null)
             onDhcpChanged(null)
-            onEndpointChange(null, null)
+            Application.getCoroutineScope().launch {
+                onPeersReset()
+            }
         } else {
             configDetail?.peers?.forEach {
-                var endpoint: InetEndpoint? = it.peer.endpoint.orElse(null)
+                var endpoint: InetEndpoint? = it.peer?.endpoint?.orElse(null)
                 it.endpoint = Optional.ofNullable(endpoint?.getResolved()?.get())
             }
         }
@@ -118,8 +123,8 @@ class ObservableTunnel internal constructor(
     }
 
     fun onConfigChanged(config: Config?): ConfigDetail? {
-        this.config = config
         this.configDetail = ConfigDetail(config)
+        this.config = config
         notifyPropertyChanged(BR.config)
         return configDetail
     }
@@ -171,18 +176,89 @@ class ObservableTunnel internal constructor(
         return dhcp
     }
 
-    override fun onEndpointChange(publicKey: Key?, newEndpoint: InetEndpoint?) {
+    // Remove dynamic peers, and reset static peers
+    fun onPeersReset() {
+        Log.i(TAG, "ObservableTunnel onPeersReset")
+        var toRemove: MutableList<PeerDetail> = ArrayList()
+
+        configDetail?.peers?.forEach {
+            if (it.peer == null) {
+                toRemove.add(it)
+            } else {
+                it.endpoint = Optional.empty()
+            }
+        }
+
+        toRemove.forEach {
+            Log.i(TAG, "ObservableTunnel remove " + it)
+            configDetail?.peers?.remove(it)
+        }
+    }
+
+    override fun onEndpointChange(publicKey: Key, newEndpoint: InetEndpoint?) {
+        Application.getCoroutineScope().launch {
+            onEndpointChanged(publicKey, newEndpoint)
+        }
+    }
+
+    private fun onEndpointChanged(publicKey: Key, newEndpoint: InetEndpoint?) {
+
         Log.i(TAG, "ObservableTunnel onEndpointChange " + newEndpoint)
+        var peer: PeerDetail? = null
+
         configDetail?.peers?.forEach {
-            Log.i(TAG, "ObservableTunnel peer " + it + ", " + it.peer)
-            if (publicKey == null || it.peer.publicKey.equals(publicKey)) {
-                if (newEndpoint == null) {
-                    it.endpoint = it.peer.endpoint
-                } else {
-                    it.endpoint = newEndpoint.getResolved()
-                }
+            if (it.publicKey.equals(publicKey) == true) {
+                Log.i(TAG, "ObservableTunnel peer " + it + ", " + it.peer)
+                peer = it;
+            }
+        }
+
+        if (peer == null) {
+            Log.i(TAG, "ObservableTunnel create peer " + publicKey)
+            peer = PeerDetail(publicKey)
+            configDetail?.peers?.add(peer)
+        }
+
+        var peer2: PeerDetail = peer!!
+
+        if (newEndpoint != null) {
+            peer2.endpoint = newEndpoint.getResolved()
+        } else {
+            var peer3 = peer2.peer
+            peer2.endpoint = if (peer3 != null) peer3.endpoint else Optional.empty()
+        }
+    }
+
+    fun lookupPeer(publicKey: Key): PeerDetail {
+        configDetail?.peers?.forEach {
+            if (it.publicKey.equals(publicKey) == true) {
+                Log.i(TAG, "ObservableTunnel peer " + it + ", " + it.peer)
+                return it
             }
         }
+
+        Log.i(TAG, "ObservableTunnel create peer " + publicKey)
+        var peer: PeerDetail = PeerDetail(publicKey)
+        configDetail?.peers?.add(peer)
+
+        return peer
+    }
+
+    override fun onAllowedIpsChange(publicKey: Key, addNetworks: List<InetNetwork>?, removeNetworks: List<InetNetwork>?) {
+        Application.getCoroutineScope().launch {
+            onAllowedIpsChanged(publicKey, addNetworks, removeNetworks)
+        }
+    }
+
+    private fun onAllowedIpsChanged(publicKey: Key, addNetworks: List<InetNetwork>?, removeNetworks: List<InetNetwork>?) {
+        var peer: PeerDetail = lookupPeer(publicKey)
+
+        removeNetworks?.let() {
+            peer.allowedIps.removeAll(removeNetworks)
+        }
+        addNetworks?.let() {
+            peer.allowedIps.addAll(addNetworks)
+        }
     }
 
 
diff --git a/ui/src/main/java/com/wireguard/android/viewmodel/PeerDetail.kt b/ui/src/main/java/com/wireguard/android/viewmodel/PeerDetail.kt
index abc81998..80b32fd5 100644
--- a/ui/src/main/java/com/wireguard/android/viewmodel/PeerDetail.kt
+++ b/ui/src/main/java/com/wireguard/android/viewmodel/PeerDetail.kt
@@ -4,25 +4,37 @@ import android.util.Log
 import androidx.databinding.BaseObservable
 import androidx.databinding.Bindable
 import androidx.databinding.Observable
+import androidx.databinding.ObservableList
+import androidx.databinding.ObservableArrayList
 
 import com.wireguard.android.BR
 import com.wireguard.config.InetEndpoint
+import com.wireguard.config.InetNetwork
 import com.wireguard.config.Peer
+import com.wireguard.crypto.Key;
 
 import java.util.Optional;
 
+import kotlin.collections.LinkedHashSet
+
 
 class PeerDetail : BaseObservable {
-    var peer: Peer
+    var peer: Peer?
     private var owner: ConfigDetail? = null
 
     @get:Bindable
+    var publicKey: Key
+
+    @get:Bindable
+    var allowedIps: ObservableList<InetNetwork> = ObservableArrayList<InetNetwork>()
+
+    @get:Bindable
     var endpoint: Optional<InetEndpoint> = Optional.empty()
         get() {
             if (!field.isEmpty()) {
                 return field
             } else {
-                return peer.endpoint
+                return Optional.ofNullable(peer?.endpoint?.get())
             }
         }
 
@@ -32,8 +44,20 @@ class PeerDetail : BaseObservable {
             notifyPropertyChanged(BR.endpoint)
         }
 
+    @get:Bindable
+    var persistentKeepalive: Optional<Int> = Optional.empty()
+
     constructor(other: Peer) {
         peer = other
+        publicKey = other.getPublicKey()
+        allowedIps.addAll(other.getAllowedIps())
+        endpoint = other.getEndpoint();
+        persistentKeepalive = other.getPersistentKeepalive()
+    }
+
+    constructor(publicKey: Key) {
+        peer = null
+        this.publicKey = publicKey
     }
 
     fun bind(owner: ConfigDetail) {
@@ -45,6 +69,16 @@ class PeerDetail : BaseObservable {
         super.addOnPropertyChangedCallback(callback)
     }
     
+    /**
+     * Converts the {@code Peer} into a string suitable for debugging purposes. The {@code Peer} is
+     * identified by its public key and (if known) its endpoint.
+     *
+     * @return a concise single-line identifier for the {@code Peer}
+     */
+    override fun toString(): String {
+        return "(Peer " + publicKey.toBase64() + ")"
+    }
+
     companion object {
         private const val TAG = "WireGuard/PeerDetail"
     }
diff --git a/ui/src/main/res/layout/tunnel_detail_fragment.xml b/ui/src/main/res/layout/tunnel_detail_fragment.xml
index 1c4c25d6..59112d5e 100644
--- a/ui/src/main/res/layout/tunnel_detail_fragment.xml
+++ b/ui/src/main/res/layout/tunnel_detail_fragment.xml
@@ -367,6 +367,7 @@
                 android:layout_marginTop="8dp"
                 android:divider="@null"
                 android:orientation="vertical"
+                app:fragment="@{fragment}"
                 app:items="@{config.peers}"
                 app:layout="@{@layout/tunnel_detail_peer}"
                 app:layout_constraintStart_toStartOf="parent"
diff --git a/ui/src/main/res/layout/tunnel_detail_peer.xml b/ui/src/main/res/layout/tunnel_detail_peer.xml
index e70c3df5..b4a07003 100644
--- a/ui/src/main/res/layout/tunnel_detail_peer.xml
+++ b/ui/src/main/res/layout/tunnel_detail_peer.xml
@@ -52,7 +52,7 @@
                 android:nextFocusForward="@id/pre_shared_key_text"
                 android:onClick="@{ClipboardUtils::copyTextView}"
                 android:singleLine="true"
-                android:text="@{item.peer.publicKey.toBase64}"
+                android:text="@{item.publicKey.toBase64}"
                 app:layout_constraintStart_toStartOf="parent"
                 app:layout_constraintTop_toBottomOf="@+id/public_key_label"
                 tools:text="wOs2eguFEohqIZxlSJ1CAT9584tc6ejj9hfGFsoBVkA=" />
@@ -93,7 +93,7 @@
                 android:layout_marginTop="8dp"
                 android:labelFor="@+id/allowed_ips_text"
                 android:text="@string/allowed_ips"
-                android:visibility="@{item.peer.allowedIps.isEmpty() ? android.view.View.GONE : android.view.View.VISIBLE}"
+                android:visibility="@{item.allowedIps.isEmpty() ? android.view.View.GONE : android.view.View.VISIBLE}"
                 app:layout_constraintStart_toStartOf="parent"
                 app:layout_constraintTop_toBottomOf="@+id/pre_shared_key_text" />
 
@@ -107,8 +107,8 @@
                 android:nextFocusDown="@id/endpoint_text"
                 android:nextFocusForward="@id/endpoint_text"
                 android:onClick="@{ClipboardUtils::copyTextView}"
-                android:text="@{item.peer.allowedIps}"
-                android:visibility="@{item.peer.allowedIps.isEmpty() ? android.view.View.GONE : android.view.View.VISIBLE}"
+                android:text="@{item.allowedIps}"
+                android:visibility="@{item.allowedIps.isEmpty() ? android.view.View.GONE : android.view.View.VISIBLE}"
                 app:layout_constraintStart_toStartOf="parent"
                 app:layout_constraintTop_toBottomOf="@+id/allowed_ips_label"
                 tools:text="0.0.0.0/5, 8.0.0.0/7, 11.0.0.0/8, 12.0.0.0/6, 16.0.0.0/4, 32.0.0.0/3" />
@@ -147,7 +147,7 @@
                 android:layout_marginTop="8dp"
                 android:labelFor="@+id/persistent_keepalive_text"
                 android:text="@string/persistent_keepalive"
-                android:visibility="@{!item.peer.persistentKeepalive.isPresent() ? android.view.View.GONE : android.view.View.VISIBLE}"
+                android:visibility="@{!item.persistentKeepalive.isPresent() ? android.view.View.GONE : android.view.View.VISIBLE}"
                 app:layout_constraintStart_toStartOf="parent"
                 app:layout_constraintTop_toBottomOf="@+id/endpoint_text" />
 
@@ -161,8 +161,8 @@
                 android:nextFocusDown="@id/transfer_text"
                 android:nextFocusForward="@id/transfer_text"
                 android:onClick="@{ClipboardUtils::copyTextView}"
-                android:text="@{@plurals/persistent_keepalive_seconds_unit(item.peer.persistentKeepalive.orElse(0), item.peer.persistentKeepalive.orElse(0))}"
-                android:visibility="@{!item.peer.persistentKeepalive.isPresent() ? android.view.View.GONE : android.view.View.VISIBLE}"
+                android:text="@{@plurals/persistent_keepalive_seconds_unit(item.persistentKeepalive.orElse(0), item.persistentKeepalive.orElse(0))}"
+                android:visibility="@{!item.persistentKeepalive.isPresent() ? android.view.View.GONE : android.view.View.VISIBLE}"
                 app:layout_constraintStart_toStartOf="parent"
                 app:layout_constraintTop_toBottomOf="@+id/persistent_keepalive_label"
                 tools:text="every 3 seconds" />