Add DNS resolver support

android/app/src/main/kotlin/net/defined/mobile_nebula/NebulaVpnService.kt

@@ -131,6 +131,11 @@ class NebulaVpnService : VpnService() {
             builder.addRoute(unsafeIPNet.network, unsafeIPNet.maskSize.toInt())
         }
 
+        // Add our DNS resolvers
+        site!!.dnsResolvers.forEach { dnsResolver ->
+            builder.addDnsServer(dnsResolver)
+        }
+
         try {
             vpnInterface = builder.establish()
             nebula = mobileNebula.MobileNebula.newNebula(site!!.config, site!!.getKey(this), site!!.logFile, vpnInterface!!.detachFd().toLong())

android/app/src/main/kotlin/net/defined/mobile_nebula/Sites.kt

@@ -201,6 +201,7 @@ class Site(context: Context, siteDir: File) {
     val id: String
     val staticHostmap: HashMap<String, StaticHosts>
     val unsafeRoutes: List<UnsafeRoute>
+    val dnsResolvers: List<String>
     var cert: CertificateInfo? = null
     var ca: Array<CertificateInfo>
     val lhDuration: Int
@@ -236,6 +237,7 @@ class Site(context: Context, siteDir: File) {
         id = incomingSite.id
         staticHostmap = incomingSite.staticHostmap
         unsafeRoutes = incomingSite.unsafeRoutes ?: ArrayList()
+        dnsResolvers = incomingSite.dnsResolvers ?: ArrayList()
         lhDuration = incomingSite.lhDuration
         port = incomingSite.port
         mtu = incomingSite.mtu ?: 1300
@@ -340,6 +342,7 @@ class IncomingSite(
     val id: String,
     val staticHostmap: HashMap<String, StaticHosts>,
     val unsafeRoutes: List<UnsafeRoute>?,
+    val dnsResolvers: List<String>?,
     val cert: String,
     val ca: String,
     val lhDuration: Int,

ios/NebulaNetworkExtension/PacketTunnelProvider.swift

@@ -78,6 +78,11 @@ class PacketTunnelProvider: NEPacketTunnelProvider {
 
         tunnelNetworkSettings.ipv4Settings!.includedRoutes = routes
         tunnelNetworkSettings.mtu = _site.mtu as NSNumber
+        
+        if !_site.dnsResolvers.isEmpty {
+            let dnsSettings = NEDNSSettings(servers: _site.dnsResolvers)
+            tunnelNetworkSettings.dnsSettings = dnsSettings
+        }
 
         self.setTunnelNetworkSettings(tunnelNetworkSettings, completionHandler: {(error:Error?) in
             if (error != nil) {

ios/NebulaNetworkExtension/Site.swift

@@ -121,6 +121,7 @@ class Site: Codable {
     // Stored in proto
     var staticHostmap: Dictionary<String, StaticHosts>
     var unsafeRoutes: [UnsafeRoute]
+    var dnsResolvers: [String]
     var cert: CertificateInfo?
     var ca: [CertificateInfo]
     var lhDuration: Int
@@ -194,6 +195,7 @@ class Site: Codable {
         id = incoming.id
         staticHostmap = incoming.staticHostmap
         unsafeRoutes = incoming.unsafeRoutes ?? []
+        dnsResolvers = incoming.dnsResolvers ?? []
         lhDuration = incoming.lhDuration
         port = incoming.port
         cipher = incoming.cipher
@@ -340,6 +342,7 @@ class Site: Codable {
         case status
         case logFile
         case unsafeRoutes
+        case dnsResolvers
         case logVerbosity
         case errors
         case mtu
@@ -394,6 +397,7 @@ struct IncomingSite: Codable {
     var id: String
     var staticHostmap: Dictionary<String, StaticHosts>
     var unsafeRoutes: [UnsafeRoute]?
+    vat dnsResolvers: [String]?
     var cert: String
     var ca: String
     var lhDuration: Int

lib/models/Site.dart

@@ -4,6 +4,7 @@ import 'dart:convert';
 import 'package:flutter/services.dart';
 import 'package:mobile_nebula/models/HostInfo.dart';
 import 'package:mobile_nebula/models/UnsafeRoute.dart';
+import 'package:mobile_nebula/models/IPAndPort.dart';
 import 'package:uuid/uuid.dart';
 import 'Certificate.dart';
 import 'StaticHosts.dart';
@@ -24,6 +25,7 @@ class Site {
   // static_host_map
   late Map<String, StaticHost> staticHostmap;
   late List<UnsafeRoute> unsafeRoutes;
+  late List<String> dnsResolvers;
 
   // pki fields
   late List<CertificateInfo> ca;
@@ -69,6 +71,7 @@ class Site {
     String logVerbosity = 'info',
     List<String>? errors,
     List<UnsafeRoute>? unsafeRoutes,
+    List<String>? dnsResolvers,
     bool managed = false,
     String? rawConfig,
     DateTime? lastManagedUpdate,
@@ -89,6 +92,7 @@ class Site {
     this.logVerbosity = logVerbosity;
     this.errors = errors ?? [];
     this.unsafeRoutes = unsafeRoutes ?? [];
+    this.dnsResolvers = dnsResolvers ?? [];
     this.managed = managed;
     this.rawConfig = rawConfig;
     this.lastManagedUpdate = lastManagedUpdate;
@@ -128,6 +132,7 @@ class Site {
       logVerbosity: decoded['logVerbosity'],
       errors: decoded['errors'],
       unsafeRoutes: decoded['unsafeRoutes'],
+      dnsResolvers: decoded['dnsResolvers'],
       managed: decoded['managed'],
       rawConfig: decoded['rawConfig'],
       lastManagedUpdate: decoded['lastManagedUpdate'],
@@ -152,6 +157,7 @@ class Site {
     this.logVerbosity = decoded['logVerbosity'];
     this.errors = decoded['errors'];
     this.unsafeRoutes = decoded['unsafeRoutes'];
+    this.dnsResolvers = decoded['dnsResolvers'];
     this.managed = decoded['managed'];
     this.rawConfig = decoded['rawConfig'];
     this.lastManagedUpdate = decoded['lastManagedUpdate'];
@@ -170,6 +176,12 @@ class Site {
       unsafeRoutes.add(UnsafeRoute.fromJson(val));
     });
 
+    List<dynamic> rawDNSResolvers = json['dnsResolvers'];
+    List<String> dnsResolvers = [];
+    rawDNSResolvers.forEach((val) {
+      dnsResolvers.add(val);
+    });
+
     List<dynamic> rawCA = json['ca'];
     List<CertificateInfo> ca = [];
     rawCA.forEach((val) {
@@ -204,6 +216,7 @@ class Site {
       "logVerbosity": json['logVerbosity'],
       "errors": errors,
       "unsafeRoutes": unsafeRoutes,
+      "dnsResolvers": dnsResolvers,
       "managed": json['managed'] ?? false,
       "rawConfig": json['rawConfig'],
       "lastManagedUpdate": json["lastManagedUpdate"] == null ?
@@ -221,6 +234,7 @@ class Site {
       'id': id,
       'staticHostmap': staticHostmap,
       'unsafeRoutes': unsafeRoutes,
+      'dnsResolvers': dnsResolvers,
       'ca': ca.map((cert) {
         return cert.rawCert;
       }).join('\n'),

lib/screens/siteConfig/AdvancedScreen.dart

@@ -10,6 +10,7 @@ import 'package:mobile_nebula/components/config/ConfigSection.dart';
 import 'package:mobile_nebula/models/Site.dart';
 import 'package:mobile_nebula/models/UnsafeRoute.dart';
 import 'package:mobile_nebula/screens/siteConfig/CipherScreen.dart';
+import 'package:mobile_nebula/screens/siteConfig/DNSResolversScreen.dart';
 import 'package:mobile_nebula/screens/siteConfig/LogVerbosityScreen.dart';
 import 'package:mobile_nebula/screens/siteConfig/RenderedConfigScreen.dart';
 import 'package:mobile_nebula/services/utils.dart';
@@ -28,6 +29,7 @@ class Advanced {
   String verbosity;
   List<UnsafeRoute> unsafeRoutes;
   int mtu;
+  List<String> dnsResolvers;
 
   Advanced({
     required this.lhDuration,
@@ -36,6 +38,7 @@ class Advanced {
     required this.verbosity,
     required this.unsafeRoutes,
     required this.mtu,
+    required this.dnsResolvers,
   });
 }
 
@@ -66,6 +69,7 @@ class _AdvancedScreenState extends State<AdvancedScreen> {
       verbosity: widget.site.logVerbosity,
       unsafeRoutes: widget.site.unsafeRoutes,
       mtu: widget.site.mtu,
+      dnsResolvers: widget.site.dnsResolvers,
     );
     super.initState();
   }
@@ -192,7 +196,26 @@ class _AdvancedScreenState extends State<AdvancedScreen> {
                         });
                   });
                 },
-              )
+              ),
+              ConfigPageItem(
+                  label: Text('DNS Resolvers'),
+                  labelWidth: 150,
+                  content: Text(
+                      Utils.itemCountFormat(settings.dnsResolvers.length),
+                      textAlign: TextAlign.end),
+                  onPressed: () {
+                    Utils.openPage(context, (context) {
+                      return DNSResolversScreen(
+                          dnsResolvers: settings.dnsResolversmm
+                          onSave: (dnsResolvers) {
+                            setState(() {
+                              settings.dnsResolvers = dnsResolvers;
+                              changed = true;
+                            });
+                          });
+                    });
+                  },
+              ),
             ],
           ),
           ConfigSection(

lib/screens/siteConfig/DNSResolverScreen.dart

@@ -0,0 +1,77 @@
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/services.dart';
+import 'package:flutter/widgets.dart';
+import 'package:flutter_platform_widgets/flutter_platform_widgets.dart';
+import 'package:mobile_nebula/components/FormPage.dart';
+import 'package:mobile_nebula/components/IPFormField.dart';
+import 'package:mobile_nebula/components/config/ConfigItem.dart';
+import 'package:mobile_nebula/components/config/ConfigSection.dart';
+import 'package:mobile_nebula/services/utils.dart';
+
+lass DNSResolverScreen extends StatefulWidget {
+  const DNSResolverScreen({Key? key, required this.dnsResolver, required this.onDelete, required this.onSave}) : super(key: key);
+
+  final String dnsResolver;
+  final ValueChanged<String> onSave;
+  final Function onDelete;
+
+  @override
+  _DNSResolverScreenState createState() => _DNSResolverScreenState();
+}
+
+class _DNSResolverScreenState extends State<DNSResolverScreen> {
+  late String dnsResolver;
+  bool changed = false;
+
+  FocusNode dnsResolverFocus = FocusNode();
+
+  @override
+  void initState() {
+    dnsResolver = widget.dnsResolver;
+    super.initState();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return FormPage(
+        title: widget.onDelete == null ? 'New DNS Resolver' : 'Edit DNS Resolver',
+        changed: changed,
+        onSave: _onSave,
+        child: Column(children: [
+          ConfigSection(children: <Widget>[
+            ConfigItem(
+                label: Text('Address'),
+                content: IPFormField(
+                    initialValue: dnsResolver,
+                    ipOnly: true,
+                    textInputAction: TextInputAction.next,
+                    focusNode: dnsResolverFocus,
+                    onSaved: (v) {
+                      dnsResolver = v.toString();
+                    })),
+          ]),
+          widget.onDelete != null
+              ? Padding(
+                  padding: EdgeInsets.only(top: 50, bottom: 10, left: 10, right: 10),
+                  child: SizedBox(
+                      width: double.infinity,
+                      child: PlatformElevatedButton(
+                        child: Text('Delete'),
+                        color: CupertinoColors.systemRed.resolveFrom(context),
+                        onPressed: () => Utils.confirmDelete(context, 'Delete DNS Resolver?', () {
+                          Navigator.of(context).pop();
+                          widget.onDelete();
+                        }),
+                      )))
+              : Container()
+        ]));
+  }
+
+  _onSave() {
+    Navigator.pop(context);
+    if (widget.onSave != null) {
+      widget.onSave(dnsResolver);
+    }
+  }
+}

lib/screens/siteConfig/DNSResolversScreen.dart

@@ -0,0 +1,103 @@
+import 'package:flutter/cupertino.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter/widgets.dart';
+import 'package:flutter/foundation.dart';
+import 'package:mobile_nebula/components/FormPage.dart';
+import 'package:mobile_nebula/components/config/ConfigButtonItem.dart';
+import 'package:mobile_nebula/components/config/ConfigPageItem.dart';
+import 'package:mobile_nebula/components/config/ConfigSection.dart';
+import 'package:mobile_nebula/screens/siteConfig/DNSResolverScreen.dart';
+import 'package:mobile_nebula/services/utils.dart';
+
+class DNSResolversScreen extends StatefulWidget {
+  const DNSResolversScreen(
+      {Key? key, required this.dnsResolvers, required this.onSave})
+      : super(key: key);
+
+  final List<String> dnsResolvers;
+  final ValueChanged<List<String>> onSave;
+
+  @override
+  _DNSResolversScreenState createState() => _DNSResolversScreenState();
+}
+
+class _DNSResolversScreenState extends State<DNSResolversScreen> {
+  late List<String> dnsResolvers = [];
+  bool changed = false;
+
+  @override
+  void initState() {
+    widget.dnsResolvers.forEach((dnsResolver) {
+      dnsResolvers.add(dnsResolver);
+    });
+    super.initState();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return FormPage(
+        title: 'DNS Resolvers',
+        changed: changed,
+        onSave: _onSave,
+        child: ConfigSection(
+          children: _build(),
+        ));
+  }
+
+  _onSave() {
+    Navigator.pop(context);
+    if (widget.onSave != null) {
+      widget.onSave(dnsResolvers);
+    }
+  }
+
+  List<Widget> _build() {
+    List<Widget> items = [];
+    for (var i=0; i<dnsResolvers.length;i++) {
+      final dnsResolver = dnsResolvers[i];
+      items.add(ConfigPageItem(
+        label: Text("Resolver"),
+        content: Text(dnsResolver, textAlign: TextAlign.end),
+        onPressed: () {
+          Utils.openPage(context, (context) {
+            return DNSResolverScreen(
+              dnsResolver: dnsResolver,
+              onSave: (dnsResolver) {
+                setState(() {
+                  changed = true;
+                  dnsResolvers[i] = dnsResolver;
+                });
+              },
+              onDelete: () {
+                setState(() {
+                  changed = true;
+                  dnsResolvers.removeAt(i);
+                });
+              },
+            );
+          });
+        },
+      ));
+    }
+
+    items.add(ConfigButtonItem(
+      content: Text('Add a new DNS resolver'),
+      onPressed: () {
+        Utils.openPage(context, (context) {
+          return DNSResolverScreen(
+              dnsResolver: "",
+              onSave: (dnsResolver) {
+                  setState(() {
+                      changed = true;
+                  });
+                  dnsResolvers.add(dnsResolver);
+              },
+              onDelete: () {},
+          );
+        });
+      },
+    ));
+
+    return items;
+  }
+}

lib/screens/siteConfig/SiteConfigScreen.dart

@@ -292,6 +292,7 @@ class _SiteConfigScreenState extends State<SiteConfigScreen> {
                         site.port = settings.port;
                         site.logVerbosity = settings.verbosity;
                         site.unsafeRoutes = settings.unsafeRoutes;
+                        site.dnsResolvers = settings.dnsResolvers;
                         site.mtu = settings.mtu;
                       });
                     });

nebula/config.go

@@ -139,6 +139,7 @@ type configTun struct {
 	MTU                *int                `yaml:"mtu,omitempty"`
 	Routes             []configRoute       `yaml:"routes"`
 	UnsafeRoutes       []configUnsafeRoute `yaml:"unsafe_routes"`
+	DNSResolvers       []string            `yaml:"dns_resolvers"`
 }
 
 type configRoute struct {

nebula/mobileNebula.go

@@ -116,6 +116,13 @@ func RenderConfig(configData string, key string) (string, error) {
 		}
 	}
 
+	if dnsResolvers, ok := d["dnsResolvers"].([]interface{}); ok {
+		cfg.Tun.DNSResolvers = make([]string, len(dnsResolvers))
+		for i, r := range dnsResolvers {
+			cfg.Tun.DNSResolvers[i] = r.(string)
+		}
+	}
+
 	finalConfig, err := yaml.Marshal(cfg)
 	if err != nil {
 		return "", err