[client] Add IPv6 dual-stack support

app/src/main/java/io/netbird/client/ui/advanced/AdvancedFragment.java

@@ -220,6 +220,7 @@ private void initializeEngineConfigSwitches() {
             binding.switchDisableFirewall.setChecked(goPreferences.getDisableFirewall());
             binding.switchAllowSsh.setChecked(goPreferences.getServerSSHAllowed());
             binding.switchBlockInbound.setChecked(goPreferences.getBlockInbound());
+            binding.switchDisableIpv6.setChecked(goPreferences.getDisableIPv6());
 
             // Set up change listeners
             binding.switchDisableClientRoutes.setOnCheckedChangeListener((buttonView, isChecked) -> {
@@ -275,7 +276,16 @@ private void initializeEngineConfigSwitches() {
                     Log.e(LOGTAG, "Failed to set block inbound", e);
                 }
             });
-
+
+            binding.switchDisableIpv6.setOnCheckedChangeListener((buttonView, isChecked) -> {
+                try {
+                    goPreferences.setDisableIPv6(isChecked);
+                    goPreferences.commit();
+                } catch (Exception e) {
+                    Log.e(LOGTAG, "Failed to set disable IPv6", e);
+                }
+            });
+
             // Make parent layouts clickable to toggle switches (for TV remote)
             binding.layoutAllowSsh.setOnClickListener(v -> {
                 binding.switchAllowSsh.toggle();
@@ -301,6 +311,10 @@ private void initializeEngineConfigSwitches() {
                 binding.switchDisableFirewall.toggle();
             });
 
+            binding.layoutDisableIpv6.setOnClickListener(v -> {
+                binding.switchDisableIpv6.toggle();
+            });
+
         } catch (Exception e) {
             Log.e(LOGTAG, "Failed to initialize engine config switches", e);
         }

app/src/main/java/io/netbird/client/ui/home/Peer.java

@@ -3,11 +3,13 @@
 public class Peer {
    private final Status status;
    private final String ip;
+   private final String ipv6;
    private final String fqdn;
 
-   public Peer(Status status, String ip, String fqdn) {
+   public Peer(Status status, String ip, String ipv6, String fqdn) {
       this.status = status;
       this.ip = ip;
+      this.ipv6 = ipv6;
       this.fqdn = fqdn;
    }
 
@@ -19,7 +21,11 @@ public String getIp() {
       return ip;
    }
 
+   public String getIpv6() {
+      return ipv6;
+   }
+
    public String getFqdn() {
       return fqdn;
    }
-}
+}

app/src/main/java/io/netbird/client/ui/home/PeersAdapter.java

@@ -120,6 +120,9 @@ private static void showPopup(View view, Peer peer) {
         PopupMenu popup = new PopupMenu(view.getContext(), view);
         popup.getMenuInflater().inflate(R.menu.peer_clipboard_menu, popup.getMenu());
 
+        boolean hasIpv6 = peer.getIpv6() != null && !peer.getIpv6().isEmpty();
+        popup.getMenu().findItem(R.id.copy_ipv6).setVisible(hasIpv6);
+
         popup.setOnMenuItemClickListener(menuItem -> {
             int id = menuItem.getItemId();
             if (id == R.id.copy_fqdn) {
@@ -128,6 +131,9 @@ private static void showPopup(View view, Peer peer) {
             } else if (id == R.id.copy_ip) {
                 copyToClipboard(view.getContext(), "IP Address", peer.getIp());
                 return true;
+            } else if (id == R.id.copy_ipv6) {
+                copyToClipboard(view.getContext(), "IPv6 Address", peer.getIpv6());
+                return true;
             }
             return false;
         });
@@ -165,7 +171,11 @@ public PeerViewHolder(ListItemPeerBinding binding) {
 
         public void bind(Peer peer) {
             binding.status.setText(peer.getStatus().toString());
-            binding.ip.setText(peer.getIp());
+            String ipDisplay = peer.getIp();
+            if (peer.getIpv6() != null && !peer.getIpv6().isEmpty()) {
+                ipDisplay = ipDisplay + "\n" + peer.getIpv6();
+            }
+            binding.ip.setText(ipDisplay);
             binding.fqdn.setText(peer.getFqdn());
 
             if (peer.getStatus() == Status.CONNECTED) {

app/src/main/java/io/netbird/client/ui/home/PeersFragmentViewModel.java

@@ -55,7 +55,7 @@ private List<Peer> getPeers(PeerInfoArray peersInfo) {
             }
 
             status = Status.fromLong(peerInfo.getConnStatus());
-            peers.add(new Peer(status, peerInfo.getIP(), peerInfo.getFQDN()));
+            peers.add(new Peer(status, peerInfo.getIP(), peerInfo.getIPv6(), peerInfo.getFQDN()));
         }
         return peers;
     }

app/src/main/java/io/netbird/client/ui/home/Resource.java

@@ -36,7 +36,7 @@ public Status getStatus() {
     }
 
     public boolean isExitNode() {
-        return address.equals("0.0.0.0/0");
+        return address != null && (address.contains("0.0.0.0/0") || address.contains("::/0"));
     }
 
     public boolean isSelected() {

app/src/main/res/layout/fragment_advanced.xml

@@ -520,6 +520,55 @@
 
             </LinearLayout>
 
+            <LinearLayout
+                android:id="@+id/layout_disable_ipv6"
+                android:layout_width="0dp"
+                android:layout_height="wrap_content"
+                android:layout_marginTop="16dp"
+                android:background="@drawable/focus_highlight"
+                android:clickable="true"
+                android:focusable="true"
+                android:focusableInTouchMode="false"
+                android:orientation="vertical"
+                android:padding="12dp"
+                app:layout_constraintEnd_toEndOf="parent"
+                app:layout_constraintStart_toStartOf="parent"
+                app:layout_constraintTop_toBottomOf="@id/layout_disable_firewall">
+
+                <LinearLayout
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content"
+                    android:gravity="center_vertical"
+                    android:orientation="horizontal">
+
+                    <TextView
+                        android:layout_width="0dp"
+                        android:layout_height="wrap_content"
+                        android:layout_weight="1"
+                        android:text="@string/advanced_disable_ipv6"
+                        android:textColor="@color/nb_txt_light" />
+
+                    <com.google.android.material.switchmaterial.SwitchMaterial
+                        android:id="@+id/switch_disable_ipv6"
+                        android:layout_width="wrap_content"
+                        android:layout_height="wrap_content"
+                        android:clickable="false"
+                        android:focusable="false" />
+
+                </LinearLayout>
+
+                <TextView
+                    android:layout_width="match_parent"
+                    android:layout_height="wrap_content"
+                    android:layout_marginStart="0dp"
+                    android:layout_marginTop="2dp"
+                    android:layout_marginEnd="48dp"
+                    android:text="@string/advanced_disable_ipv6_desc"
+                    android:textColor="@color/nb_txt_light"
+                    android:textSize="12sp" />
+
+            </LinearLayout>
+
             <include
                 android:id="@+id/layout_force_relay_connection"
                 layout="@layout/component_switch"
@@ -529,7 +578,7 @@
                 android:orientation="vertical"
                 app:layout_constraintEnd_toEndOf="parent"
                 app:layout_constraintStart_toStartOf="parent"
-                app:layout_constraintTop_toBottomOf="@id/layout_disable_firewall" />
+                app:layout_constraintTop_toBottomOf="@id/layout_disable_ipv6" />
 
             <LinearLayout
                 android:id="@+id/layout_theme"

app/src/main/res/menu/peer_clipboard_menu.xml

@@ -5,4 +5,7 @@
     <item
         android:id="@+id/copy_ip"
         android:title="@string/peers_clipboard_copy_ip" />
+    <item
+        android:id="@+id/copy_ipv6"
+        android:title="@string/peers_clipboard_copy_ipv6" />
 </menu>

app/src/main/res/values/strings.xml

@@ -40,6 +40,7 @@
     <string name="peer_filter_connecting">Connecting</string>
     <string name="peer_filter_connected">Connected</string>
     <string name="peers_clipboard_copy_ip">Copy IP</string>
+    <string name="peers_clipboard_copy_ipv6">Copy IPv6</string>
     <string name="peers_clipboard_copy_fqdn">Copy FQDN</string>
     <string name="peers_desc_filter">Filter</string>
 
@@ -89,6 +90,8 @@
     <string name="advanced_disable_dns_desc">Disables NetBird DNS configuration on this device</string>
     <string name="advanced_disable_firewall">Disable firewall</string>
     <string name="advanced_disable_firewall_desc">Disables the NetBird firewall</string>
+    <string name="advanced_disable_ipv6">Disable IPv6</string>
+    <string name="advanced_disable_ipv6_desc">Disables IPv6 overlay addressing on the tunnel interface</string>
     <string name="advanced_allow_ssh">Enable SSH</string>
     <string name="advanced_allow_ssh_desc">Allows SSH connections to this device</string>
     <string name="advanced_block_inbound">Block inbound connections</string>

tool/src/main/java/io/netbird/client/tool/IFace.java

@@ -28,22 +28,26 @@ public IFace(VPNService vpnService) {
     }
 
     @Override
-    public long configureInterface(String address, long mtu, String dns, String searchDomainsString, String routesString) throws Exception {
+    public long configureInterface(String address, String addressV6, long mtu, String dns, String searchDomainsString, String routesString) throws Exception {
         String[] searchDomains = toSearchDomains(searchDomainsString);
         LinkedList<Route> routes = toRoutes(routesString);
 
         InetNetwork addr = InetNetwork.parse(address);
+        InetNetwork addrV6 = null;
+        if (addressV6 != null && !addressV6.isEmpty()) {
+            addrV6 = InetNetwork.parse(addressV6);
+        }
         long fd = -1;
 
         try {
-            fd = createTun(addr.getAddress().getHostAddress(), addr.getMask(), (int) mtu, dns, searchDomains, routes);
+            fd = createTun(addr.getAddress().getHostAddress(), addr.getMask(), addrV6, (int) mtu, dns, searchDomains, routes);
         } catch (Exception e) {
             Log.e(LOGTAG, "failed to create tunnel", e);
         }
 
         // only set the currently used TUN parameters if createTun didn't throw exceptions
         if (fd != -1) {
-            this.vpnService.setCurrentTUNParameters(new TUNParameters(address, mtu, dns, searchDomainsString, routesString));
+            this.vpnService.setCurrentTUNParameters(new TUNParameters(address, addressV6, mtu, dns, searchDomainsString, routesString));
         }
 
         return fd;
@@ -57,9 +61,13 @@ public boolean protectSocket(int fd) {
         return true;
     }
 
-    private int createTun(String ip, int prefixLength, int mtu, String dns, String[] searchDomains, LinkedList<Route> routes) throws Exception {
+    private int createTun(String ip, int prefixLength, InetNetwork addrV6, int mtu, String dns, String[] searchDomains, LinkedList<Route> routes) throws Exception {
         VpnService.Builder builder = vpnService.getBuilder();
         builder.addAddress(ip, prefixLength);
+        if (addrV6 != null) {
+            builder.addAddress(addrV6.getAddress().getHostAddress(), addrV6.getMask());
+            Log.d(LOGTAG, "add IPv6 address: " + addrV6.getAddress().getHostAddress() + "/" + addrV6.getMask());
+        }
         builder.allowFamily(OsConstants.AF_INET);
         builder.allowFamily(OsConstants.AF_INET6);
         builder.setMtu(mtu);
@@ -69,6 +77,10 @@ private int createTun(String ip, int prefixLength, int mtu, String dns, String[]
             Log.d(LOGTAG,"add search domain: "+ sd);
         }
 
+        if (addrV6 == null && hasIPv4DefaultRoute(routes)) {
+            routes.add(new Route("::/0"));
+        }
+
         for (Route r : routes) {
             builder.addRoute(r.addr, r.prefixLength);
             Log.d(LOGTAG, "add route: "+r.addr+"/"+r.prefixLength);
@@ -149,6 +161,17 @@ private String[] toSearchDomains(String searchDomains) {
         return searchDomains.split(";");
     }
 
+    // Blackhole IPv6 when the tunnel has an IPv4 default route but no IPv6
+    // address on the interface, to prevent IPv6 leaks around the tunnel.
+    private boolean hasIPv4DefaultRoute(LinkedList<Route> routes) {
+        for (Route r : routes) {
+            if ("0.0.0.0".equals(r.addr) && r.prefixLength == 0) {
+                return true;
+            }
+        }
+        return false;
+    }
+
     private LinkedList<Route> toRoutes(String routesString) {
         LinkedList<Route> routesList = new LinkedList<>();
         if(routesString == null) {

tool/src/main/java/io/netbird/client/tool/NetworkChangeNotifier.java

@@ -39,7 +39,10 @@ public void onNetworkChanged(String routes) {
 
     @Override
     public void setInterfaceIP(String ip) {
+    }
 
+    @Override
+    public void setInterfaceIPv6(String ip) {
     }
 
     public void addRouteChangeListener(RouteChangeListener routeChangeListener) {

tool/src/main/java/io/netbird/client/tool/TUNParameters.java

@@ -2,13 +2,15 @@
 
 public class TUNParameters {
     String address;
+    String addressV6;
     long mtu;
     String dns;
     String searchDomainsString;
     String routesString;
 
-    public TUNParameters(String address, long mtu, String dns, String searchDomainsString, String routesString) {
+    public TUNParameters(String address, String addressV6, long mtu, String dns, String searchDomainsString, String routesString) {
         this.address = address;
+        this.addressV6 = addressV6;
         this.mtu = mtu;
         this.dns = dns;
         this.searchDomainsString = searchDomainsString;

tool/src/main/java/io/netbird/client/tool/VPNService.java

@@ -307,6 +307,7 @@ private void recreateTUN(String routes) {
             try {
                 int fd = (int)iface.configureInterface(
                         currentTUNParameters.address,
+                        currentTUNParameters.addressV6,
                         currentTUNParameters.mtu,
                         currentTUNParameters.dns,
                         currentTUNParameters.searchDomainsString,