DNSSettings: add custom DNS configuration

3 files changed, 146 insertions, 0 deletions

diff --git a/ios/MullvadVPN.xcodeproj/project.pbxproj b/ios/MullvadVPN.xcodeproj/project.pbxproj
index 4417fd14e9..5d9c205ec8 100644
--- a/ios/MullvadVPN.xcodeproj/project.pbxproj
+++ b/ios/MullvadVPN.xcodeproj/project.pbxproj
@@ -98,6 +98,8 @@
 		584789BE264D4A2A000E45FB /* le_root_cert.cer in Resources */ = {isa = PBXBuildFile; fileRef = 584789B7264D4A2A000E45FB /* le_root_cert.cer */; };
 		584789E026529D72000E45FB /* SSLPinningURLSessionDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = 584789DF26529D72000E45FB /* SSLPinningURLSessionDelegate.swift */; };
 		584789EC2652A1A2000E45FB /* Logging in Frameworks */ = {isa = PBXBuildFile; productRef = 584789EB2652A1A2000E45FB /* Logging */; };
+		584D26BF270C550B004EA533 /* AnyIPAddress.swift in Sources */ = {isa = PBXBuildFile; fileRef = 584D26BE270C550B004EA533 /* AnyIPAddress.swift */; };
+		584D26C0270C550E004EA533 /* AnyIPAddress.swift in Sources */ = {isa = PBXBuildFile; fileRef = 584D26BE270C550B004EA533 /* AnyIPAddress.swift */; };
 		584E96BC240FD4DA00D3334F /* Location.swift in Sources */ = {isa = PBXBuildFile; fileRef = 58A1AA8623F43901009F7EA6 /* Location.swift */; };
 		584E96BD240FD4DA00D3334F /* Location.swift in Sources */ = {isa = PBXBuildFile; fileRef = 58A1AA8623F43901009F7EA6 /* Location.swift */; };
 		584E96BE240FD4DB00D3334F /* Location.swift in Sources */ = {isa = PBXBuildFile; fileRef = 58A1AA8623F43901009F7EA6 /* Location.swift */; };
@@ -394,6 +396,7 @@
 		584789B7264D4A2A000E45FB /* le_root_cert.cer */ = {isa = PBXFileReference; lastKnownFileType = file; path = le_root_cert.cer; sourceTree = "<group>"; };
 		584789DF26529D72000E45FB /* SSLPinningURLSessionDelegate.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SSLPinningURLSessionDelegate.swift; sourceTree = "<group>"; };
 		584B26F3237434D00073B10E /* RelaySelectorTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = RelaySelectorTests.swift; sourceTree = "<group>"; };
+		584D26BE270C550B004EA533 /* AnyIPAddress.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AnyIPAddress.swift; sourceTree = "<group>"; };
 		5850366725A47AC700A43E93 /* IPAddressRange+Codable.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "IPAddressRange+Codable.swift"; sourceTree = "<group>"; };
 		58561C98239A5D1500BD6B5E /* IPEndpoint.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = IPEndpoint.swift; sourceTree = "<group>"; };
 		5857F24224C8662600CF6F47 /* SelectLocationHeaderView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SelectLocationHeaderView.swift; sourceTree = "<group>"; };
@@ -786,6 +789,7 @@
 				582AE30F2440A6CA00E6733A /* AccountTokenInput.swift */,
 				58CCA01722426713004F3011 /* AccountViewController.swift */,
 				58B9EB122488ED2100095626 /* AlertPresenter.swift */,
+				584D26BE270C550B004EA533 /* AnyIPAddress.swift */,
 				5868585424054096000B8131 /* AppButton.swift */,
 				58CE5E63224146200008646E /* AppDelegate.swift */,
 				58BFA5CB22A7CE1F00A6173D /* ApplicationConfiguration.swift */,
@@ -1337,6 +1341,7 @@
 				5820674926E63EC900655B05 /* Promise+BackgroundTask.swift in Sources */,
 				58B9EB132488ED2100095626 /* AlertPresenter.swift in Sources */,
 				587A01FC23F1F0BE00B68763 /* SimulatorTunnelProviderHost.swift in Sources */,
+				584D26BF270C550B004EA533 /* AnyIPAddress.swift in Sources */,
 				5862805422428EF100F5A6E1 /* TranslucentButtonBlurView.swift in Sources */,
 				580EE20624B3222200F9D8A1 /* ExclusivityController.swift in Sources */,
 				5888AD83227B11080051EB06 /* SelectLocationCell.swift in Sources */,
@@ -1421,6 +1426,7 @@
 				58BFA5CD22A7CE1F00A6173D /* ApplicationConfiguration.swift in Sources */,
 				5850368D25A49E2200A43E93 /* PrivateKeyWithMetadata.swift in Sources */,
 				5820675826E652AF00655B05 /* RelayCacheIO.swift in Sources */,
+				584D26C0270C550E004EA533 /* AnyIPAddress.swift in Sources */,
 				5820675726E652A600655B05 /* REST.swift in Sources */,
 				585DA88F26B031E200B8C587 /* TunnelIPCCoding.swift in Sources */,
 				5806767C27048E9B00C858CB /* PacketTunnelProvider.swift in Sources */,
diff --git a/ios/MullvadVPN/AnyIPAddress.swift b/ios/MullvadVPN/AnyIPAddress.swift
new file mode 100644
index 0000000000..1898754a69
--- /dev/null
+++ b/ios/MullvadVPN/AnyIPAddress.swift
@@ -0,0 +1,101 @@
+//
+//  AnyIPAddress.swift
+//  MullvadVPN
+//
+//  Created by pronebird on 05/10/2021.
+//  Copyright © 2021 Mullvad VPN AB. All rights reserved.
+//
+
+import Foundation
+import Network
+
+/// Container type that holds either `IPv4Address` or `IPv6Address`.
+enum AnyIPAddress: IPAddress, Codable, Equatable, CustomDebugStringConvertible {
+    case ipv4(IPv4Address)
+    case ipv6(IPv6Address)
+
+    private enum CodingKeys: String, CodingKey {
+        case ipv4, ipv6
+    }
+
+    private var innerAddress: IPAddress {
+        switch self {
+        case .ipv4(let ipv4Address):
+            return ipv4Address
+        case .ipv6(let ipv6Address):
+            return ipv6Address
+        }
+    }
+
+    var rawValue: Data {
+        return innerAddress.rawValue
+    }
+
+    init(from decoder: Decoder) throws {
+        let container = try decoder.container(keyedBy: CodingKeys.self)
+
+        if container.contains(.ipv4) {
+            self = .ipv4(try container.decode(IPv4Address.self, forKey: .ipv4))
+        } else if container.contains(.ipv6) {
+            self = .ipv6(try container.decode(IPv6Address.self, forKey: .ipv6))
+        } else {
+            throw DecodingError.dataCorruptedError(forKey: .ipv4, in: container, debugDescription: "Invalid AnyIPAddress representation")
+        }
+    }
+
+    func encode(to encoder: Encoder) throws {
+        var container = encoder.container(keyedBy: CodingKeys.self)
+
+        switch self {
+        case .ipv4(let ipv4Address):
+            try container.encode(ipv4Address, forKey: .ipv4)
+        case .ipv6(let ipv6Address):
+            try container.encode(ipv6Address, forKey: .ipv6)
+        }
+    }
+
+    init?(_ rawValue: Data, _ interface: NWInterface?) {
+        if let ipv4Address = IPv4Address(rawValue, interface) {
+            self = .ipv4(ipv4Address)
+        } else if let ipv6Address = IPv6Address(rawValue, interface) {
+            self = .ipv6(ipv6Address)
+        } else {
+            return nil
+        }
+    }
+
+    init?(_ string: String) {
+        if let ipv4Address = IPv4Address(string) {
+            self = .ipv4(ipv4Address)
+        } else if let ipv6Address = IPv6Address(string) {
+            self = .ipv6(ipv6Address)
+        } else {
+            return nil
+        }
+    }
+
+    var interface: NWInterface? {
+        return innerAddress.interface
+    }
+
+    var isLoopback: Bool {
+        return innerAddress.isLoopback
+    }
+
+    var isLinkLocal: Bool {
+        return innerAddress.isLinkLocal
+    }
+
+    var isMulticast: Bool {
+        return innerAddress.isMulticast
+    }
+
+    var debugDescription: String {
+        switch self {
+        case .ipv4(let ipv4Address):
+            return "\(ipv4Address)"
+        case .ipv6(let ipv6Address):
+            return "\(ipv6Address)"
+        }
+    }
+}
diff --git a/ios/MullvadVPN/TunnelSettings.swift b/ios/MullvadVPN/TunnelSettings.swift
index c8503c894d..9f3b47162d 100644
--- a/ios/MullvadVPN/TunnelSettings.swift
+++ b/ios/MullvadVPN/TunnelSettings.swift
@@ -58,9 +58,48 @@ struct TunnelSettings: Codable, Equatable {
 
 /// A struct that holds DNS settings.
 struct DNSSettings: Codable, Equatable {
+    /// Maximum number of allowed DNS domains.
+    static let maxAllowedCustomDNSDomains = 3
+
     /// Block advertising.
     var blockAdvertising: Bool = false
 
     /// Block tracking.
     var blockTracking: Bool = false
+
+    /// Enable custom DNS.
+    var enableCustomDNS: Bool = false
+
+    /// Custom DNS domains.
+    var customDNSDomains: [AnyIPAddress] = []
+
+    private enum CodingKeys: String, CodingKey {
+        case blockAdvertising, blockTracking, enableCustomDNS, customDNSDomains
+    }
+
+    init() {}
+
+    init(from decoder: Decoder) throws {
+        let container = try decoder.container(keyedBy: CodingKeys.self)
+
+        blockAdvertising = try container.decode(Bool.self, forKey: .blockAdvertising)
+        blockTracking = try container.decode(Bool.self, forKey: .blockTracking)
+
+        if let storedEnableCustomDNS = try container.decodeIfPresent(Bool.self, forKey: .enableCustomDNS) {
+            enableCustomDNS = storedEnableCustomDNS
+        }
+
+        if let storedCustomDNSDomains = try container.decodeIfPresent([AnyIPAddress].self, forKey: .customDNSDomains) {
+            customDNSDomains = storedCustomDNSDomains
+        }
+    }
+
+    func encode(to encoder: Encoder) throws {
+        var container = encoder.container(keyedBy: CodingKeys.self)
+
+        try container.encode(blockAdvertising, forKey: .blockAdvertising)
+        try container.encode(blockTracking, forKey: .blockTracking)
+        try container.encode(enableCustomDNS, forKey: .enableCustomDNS)
+        try container.encode(customDNSDomains, forKey: .customDNSDomains)
+    }
 }