Upgrade settings to associate with multi-hop

ios/MullvadREST/Relay/NoRelaysSatisfyingConstraintsError.swift

@@ -0,0 +1,15 @@
+//
+//  NoRelaysSatisfyingConstraintsError.swift
+//  MullvadREST
+//
+//  Created by Mojgan on 2024-04-26.
+//  Copyright © 2024 Mullvad VPN AB. All rights reserved.
+//
+
+import Foundation
+
+public struct NoRelaysSatisfyingConstraintsError: LocalizedError {
+    public var errorDescription: String? {
+        "No relays satisfying constraints."
+    }
+}

ios/MullvadREST/Relay/RelaySelectorResult.swift

@@ -0,0 +1,18 @@
+//
+//  RelaySelectorResult.swift
+//  MullvadREST
+//
+//  Created by Mojgan on 2024-05-14.
+//  Copyright © 2024 Mullvad VPN AB. All rights reserved.
+//
+
+import Foundation
+import MullvadTypes
+
+public typealias RelaySelectorResult = RelaySelectorMatch
+
+public struct RelaySelectorMatch: Codable, Equatable {
+    public var endpoint: MullvadEndpoint
+    public var relay: REST.ServerRelay
+    public var location: Location
+}

ios/MullvadREST/Transport/Shadowsocks/ShadowsocksLoader.swift

@@ -7,6 +7,7 @@
 //
 
 import Foundation
+import MullvadSettings
 import MullvadTypes
 
 public protocol ShadowsocksLoaderProtocol {
@@ -19,6 +20,11 @@ public class ShadowsocksLoader: ShadowsocksLoaderProtocol {
     private let relayCache: RelayCacheProtocol
     private var relayConstraints = RelayConstraints()
     private let constraintsUpdater: RelayConstraintsUpdater
+    private let tunnelSettings: LatestTunnelSettings? = try? SettingsManager.readSettings()
+
+    private var location: RelayConstraint<UserSelectedRelays> {
+        tunnelSettings?.tunnelMultihopState == .on ? relayConstraints.entryLocations : relayConstraints.exitLocations
+    }
 
     public init(
         shadowsocksCache: ShadowsocksConfigurationCache,
@@ -55,12 +61,15 @@ public class ShadowsocksLoader: ShadowsocksLoaderProtocol {
     /// Returns a randomly selected shadowsocks configuration.
     private func create() throws -> ShadowsocksConfiguration {
         let cachedRelays = try relayCache.read()
-        let bridgeConfiguration = RelaySelector.shadowsocksTCPBridge(from: cachedRelays.relays)
-        let closestRelay = RelaySelector.closestShadowsocksRelayConstrained(
-            by: relayConstraints,
+        let bridgeConfiguration = RelaySelector.Shadowsocks.tcpBridge(from: cachedRelays.relays)
+
+        // TODO: pick entry if multi hop is enabled otherwise pick exit entry
+        let closestRelay = RelaySelector.Shadowsocks.closestRelay(
+            location: location,
+            port: relayConstraints.port,
+            filter: relayConstraints.filter,
             in: cachedRelays.relays
         )
-
         guard let bridgeAddress = closestRelay?.ipv4AddrIn, let bridgeConfiguration else { throw POSIXError(.ENOENT) }
 
         return ShadowsocksConfiguration(

ios/MullvadSettings/MultihopSettings.swift

@@ -0,0 +1,15 @@
+//
+//  MultihopSettings.swift
+//  MullvadSettings
+//
+//  Created by Mojgan on 2024-04-26.
+//  Copyright © 2024 Mullvad VPN AB. All rights reserved.
+//
+
+import Foundation
+
+/// Whether Multi-hop is enabled
+public enum MultihopState: Codable {
+    case on
+    case off
+}

ios/MullvadSettings/TunnelSettings.swift

@@ -9,7 +9,7 @@
 import Foundation
 
 /// Alias to the latest version of the `TunnelSettings`.
-public typealias LatestTunnelSettings = TunnelSettingsV4
+public typealias LatestTunnelSettings = TunnelSettingsV5
 
 /// Protocol all TunnelSettings must adhere to, for upgrade purposes.
 public protocol TunnelSettings: Codable {
@@ -27,14 +27,19 @@ public enum SchemaVersion: Int, Equatable {
     /// V2 format with WireGuard obfuscation options, stored as `TunnelSettingsV3`.
     case v3 = 3
 
+    /// V3 format with post quantum options, stored as `TunnelSettingsV4`.
     case v4 = 4
 
+    /// V4 format with multi-hop options, stored as `TunnelSettingsV5`.
+    case v5 = 5
+
     var settingsType: any TunnelSettings.Type {
         switch self {
         case .v1: return TunnelSettingsV1.self
         case .v2: return TunnelSettingsV2.self
         case .v3: return TunnelSettingsV3.self
         case .v4: return TunnelSettingsV4.self
+        case .v5: return TunnelSettingsV5.self
         }
     }
 
@@ -43,10 +48,11 @@ public enum SchemaVersion: Int, Equatable {
         case .v1: return .v2
         case .v2: return .v3
         case .v3: return .v4
-        case .v4: return .v4
+        case .v4: return .v5
+        case .v5: return .v5
         }
     }
 
     /// Current schema version.
-    public static let current = SchemaVersion.v4
+    public static let current = SchemaVersion.v5
 }

ios/MullvadSettings/TunnelSettingsUpdate.swift

@@ -14,6 +14,7 @@ public enum TunnelSettingsUpdate {
     case obfuscation(WireGuardObfuscationSettings)
     case relayConstraints(RelayConstraints)
     case quantumResistance(TunnelQuantumResistance)
+    case multihop(MultihopState)
 }
 
 extension TunnelSettingsUpdate {
@@ -27,6 +28,8 @@ extension TunnelSettingsUpdate {
             settings.relayConstraints = newRelayConstraints
         case let .quantumResistance(newQuantumResistance):
             settings.tunnelQuantumResistance = newQuantumResistance
+        case let .multihop(newState):
+            settings.tunnelMultihopState = newState
         }
     }
 
@@ -36,6 +39,7 @@ extension TunnelSettingsUpdate {
         case .obfuscation: "obfuscation settings"
         case .relayConstraints: "relay constraints"
         case .quantumResistance: "quantum resistance"
+        case .multihop: "Multihop"
         }
     }
 }

ios/MullvadSettings/TunnelSettingsV4.swift

@@ -35,6 +35,12 @@ public struct TunnelSettingsV4: Codable, Equatable, TunnelSettings {
     }
 
     public func upgradeToNextVersion() -> any TunnelSettings {
-        self
+        TunnelSettingsV5(
+            relayConstraints: relayConstraints,
+            dnsSettings: dnsSettings,
+            wireGuardObfuscation: wireGuardObfuscation,
+            tunnelQuantumResistance: tunnelQuantumResistance,
+            tunnelMultihopState: .off
+        )
     }
 }

ios/MullvadSettings/TunnelSettingsV5.swift

@@ -0,0 +1,46 @@
+//
+//  TunnelSettingsV5.swift
+//  MullvadSettings
+//
+//  Created by Mojgan on 2024-05-13.
+//  Copyright © 2024 Mullvad VPN AB. All rights reserved.
+//
+
+import Foundation
+import MullvadTypes
+
+public struct TunnelSettingsV5: Codable, Equatable, TunnelSettings {
+    /// Relay constraints.
+    public var relayConstraints: RelayConstraints
+
+    /// DNS settings.
+    public var dnsSettings: DNSSettings
+
+    /// WireGuard obfuscation settings
+    public var wireGuardObfuscation: WireGuardObfuscationSettings
+
+    /// Whether Post Quantum exchanges are enabled.
+    public var tunnelQuantumResistance: TunnelQuantumResistance
+
+    /// Whether Multi-hop is enabled.
+    public var tunnelMultihopState: MultihopState
+
+    public init(
+        relayConstraints: RelayConstraints = RelayConstraints(),
+        dnsSettings: DNSSettings = DNSSettings(),
+        wireGuardObfuscation: WireGuardObfuscationSettings = WireGuardObfuscationSettings(),
+        tunnelQuantumResistance: TunnelQuantumResistance = .automatic,
+        tunnelMultihopState: MultihopState = .off
+
+    ) {
+        self.relayConstraints = relayConstraints
+        self.dnsSettings = dnsSettings
+        self.wireGuardObfuscation = wireGuardObfuscation
+        self.tunnelQuantumResistance = tunnelQuantumResistance
+        self.tunnelMultihopState = tunnelMultihopState
+    }
+
+    public func upgradeToNextVersion() -> any TunnelSettings {
+        self
+    }
+}

ios/MullvadTypes/RelayConstraints.swift

@@ -20,28 +20,31 @@ public class RelayConstraintsUpdater: ConstraintsPropagation {
     }
 }
 
-public struct RelayConstraints: Codable, Equatable, CustomDebugStringConvertible {
+public struct RelayConstraints: Codable, Equatable {
     @available(*, deprecated, renamed: "locations")
     private var location: RelayConstraint<RelayLocation> = .only(.country("se"))
 
-    // Added in 2023.3
-    public var port: RelayConstraint<UInt16>
-    public var filter: RelayConstraint<RelayFilter>
-
     // Added in 2024.1
     // Changed from RelayLocations to UserSelectedRelays in 2024.3
-    public var locations: RelayConstraint<UserSelectedRelays>
+    @available(*, deprecated, renamed: "exitLocations")
+    private var locations: RelayConstraint<UserSelectedRelays> = .only(UserSelectedRelays(locations: [.country("se")]))
 
-    public var debugDescription: String {
-        "RelayConstraints { locations: \(locations), port: \(port), filter: \(filter) }"
-    }
+    // Added in 2024.5 to support multi-hop
+    public var entryLocations: RelayConstraint<UserSelectedRelays>
+    public var exitLocations: RelayConstraint<UserSelectedRelays>
+
+    // Added in 2023.3
+    public var port: RelayConstraint<UInt16>
+    public var filter: RelayConstraint<RelayFilter>
 
     public init(
-        locations: RelayConstraint<UserSelectedRelays> = .only(UserSelectedRelays(locations: [.country("se")])),
+        entryLocations: RelayConstraint<UserSelectedRelays> = .only(UserSelectedRelays(locations: [.country("se")])),
+        exitLocations: RelayConstraint<UserSelectedRelays> = .only(UserSelectedRelays(locations: [.country("se")])),
         port: RelayConstraint<UInt16> = .any,
         filter: RelayConstraint<RelayFilter> = .any
     ) {
-        self.locations = locations
+        self.entryLocations = entryLocations
+        self.exitLocations = exitLocations
         self.port = port
         self.filter = filter
     }
@@ -53,9 +56,19 @@ public struct RelayConstraints: Codable, Equatable, CustomDebugStringConvertible
         port = try container.decodeIfPresent(RelayConstraint<UInt16>.self, forKey: .port) ?? .any
         filter = try container.decodeIfPresent(RelayConstraint<RelayFilter>.self, forKey: .filter) ?? .any
 
-        // Added in 2024.1
-        locations = try container.decodeIfPresent(RelayConstraint<UserSelectedRelays>.self, forKey: .locations)
-            ?? Self.migrateRelayLocation(decoder: decoder)
+        // Added in 2024.5
+        entryLocations = try container.decodeIfPresent(
+            RelayConstraint<UserSelectedRelays>.self,
+            forKey: .entryLocations
+        ) ?? .only(UserSelectedRelays(locations: [.country("se")]))
+
+        exitLocations = try container
+            .decodeIfPresent(RelayConstraint<UserSelectedRelays>.self, forKey: .exitLocations) ??
+            container.decodeIfPresent(
+                RelayConstraint<UserSelectedRelays>.self,
+                forKey: .locations
+            ) ??
+            Self.migrateRelayLocation(decoder: decoder)
             ?? .only(UserSelectedRelays(locations: [.country("se")]))
     }
 }