Model, Tunnels manager: Rewrite the model for VPN-on-demand

The VPN-on-demand settings should not be part of the tunnel
configuration. Rather, the onDemandRules stored in the
tunnel provider configuration serve as the one place
where the VPN-on-demand settings are stored.

Signed-off-by: Roopesh Chander <roop@roopc.net>

2 files changed, 86 insertions, 36 deletions

diff --git a/WireGuard/WireGuard/VPN/ActivateOnDemandSetting.swift b/WireGuard/WireGuard/VPN/ActivateOnDemandSetting.swift
new file mode 100644
index 0000000..a2cbe00
--- /dev/null
+++ b/WireGuard/WireGuard/VPN/ActivateOnDemandSetting.swift
@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: MIT
+// Copyright © 2018 WireGuard LLC. All Rights Reserved.
+
+import NetworkExtension
+
+struct ActivateOnDemandSetting {
+    var isActivateOnDemandEnabled: Bool
+    var activateOnDemandOption: ActivateOnDemandOption
+}
+
+enum ActivateOnDemandOption {
+    case none // Valid only when isActivateOnDemandEnabled is false
+    case useOnDemandOverWifiOrCellular
+    case useOnDemandOverWifiOnly
+    case useOnDemandOverCellularOnly
+}
+
+extension ActivateOnDemandSetting {
+    func apply(on tunnelProviderManager: NETunnelProviderManager) {
+        tunnelProviderManager.isOnDemandEnabled = isActivateOnDemandEnabled
+        let rules: [NEOnDemandRule]?
+        let connectRule = NEOnDemandRuleConnect()
+        let disconnectRule = NEOnDemandRuleDisconnect()
+        switch (activateOnDemandOption) {
+        case .none:
+            rules = nil
+        case .useOnDemandOverWifiOrCellular:
+            rules = [connectRule]
+        case .useOnDemandOverWifiOnly:
+            connectRule.interfaceTypeMatch = .wiFi
+            disconnectRule.interfaceTypeMatch = .cellular
+            rules = [connectRule, disconnectRule]
+        case .useOnDemandOverCellularOnly:
+            connectRule.interfaceTypeMatch = .cellular
+            disconnectRule.interfaceTypeMatch = .wiFi
+            rules = [connectRule, disconnectRule]
+        }
+        tunnelProviderManager.onDemandRules = rules
+    }
+
+    init(from tunnelProviderManager: NETunnelProviderManager) {
+        let rules = tunnelProviderManager.onDemandRules ?? []
+        let activateOnDemandOption: ActivateOnDemandOption
+        switch (rules.count) {
+        case 0:
+            activateOnDemandOption = .none
+        case 1:
+            let rule = rules[0]
+            precondition(rule.action == .connect)
+            activateOnDemandOption = .useOnDemandOverWifiOrCellular
+        case 2:
+            let connectRule = rules.first(where: { $0.action == .connect })!
+            let disconnectRule = rules.first(where: { $0.action == .disconnect })!
+            if (connectRule.interfaceTypeMatch == .wiFi && disconnectRule.interfaceTypeMatch == .cellular) {
+                activateOnDemandOption = .useOnDemandOverWifiOnly
+            } else if (connectRule.interfaceTypeMatch == .cellular && disconnectRule.interfaceTypeMatch == .wiFi) {
+                activateOnDemandOption = .useOnDemandOverCellularOnly
+            } else {
+                fatalError("Unexpected onDemandRules set on tunnel provider manager")
+            }
+        default:
+            fatalError("Unexpected number of onDemandRules set on tunnel provider manager")
+        }
+        self.activateOnDemandOption = activateOnDemandOption
+        if (activateOnDemandOption == .none) {
+            self.isActivateOnDemandEnabled = false
+        } else {
+            self.isActivateOnDemandEnabled = tunnelProviderManager.isOnDemandEnabled
+        }
+    }
+}
+
+extension ActivateOnDemandSetting {
+    static var defaultSetting = ActivateOnDemandSetting(isActivateOnDemandEnabled: false, activateOnDemandOption: .none)
+}
diff --git a/WireGuard/WireGuard/VPN/TunnelsManager.swift b/WireGuard/WireGuard/VPN/TunnelsManager.swift
index 8eb2112..d75e6c0 100644
--- a/WireGuard/WireGuard/VPN/TunnelsManager.swift
+++ b/WireGuard/WireGuard/VPN/TunnelsManager.swift
@@ -54,7 +54,9 @@ class TunnelsManager {
         #endif
     }
 
-    func add(tunnelConfiguration: TunnelConfiguration, completionHandler: @escaping (TunnelContainer?, TunnelManagementError?) -> Void) {
+    func add(tunnelConfiguration: TunnelConfiguration,
+             activateOnDemandSetting: ActivateOnDemandSetting = ActivateOnDemandSetting.defaultSetting,
+             completionHandler: @escaping (TunnelContainer?, TunnelManagementError?) -> Void) {
         let tunnelName = tunnelConfiguration.interface.name
         if tunnelName.isEmpty {
             completionHandler(nil, TunnelManagementError.tunnelAlreadyExistsWithThatName)
@@ -72,13 +74,7 @@ class TunnelsManager {
         tunnelProviderManager.localizedDescription = tunnelName
         tunnelProviderManager.isEnabled = true
 
-        if (tunnelConfiguration.activationType == .activateManually) {
-            tunnelProviderManager.onDemandRules = []
-            tunnelProviderManager.isOnDemandEnabled = false
-        } else {
-            tunnelProviderManager.onDemandRules = onDemandRules(for: tunnelConfiguration.activationType)
-            tunnelProviderManager.isOnDemandEnabled = true
-        }
+        activateOnDemandSetting.apply(on: tunnelProviderManager)
 
         tunnelProviderManager.saveToPreferences { [weak self] (error) in
             defer { self?.isAddingTunnel = false }
@@ -114,7 +110,8 @@ class TunnelsManager {
         }
     }
 
-    func modify(tunnel: TunnelContainer, with tunnelConfiguration: TunnelConfiguration, completionHandler: @escaping (TunnelManagementError?) -> Void) {
+    func modify(tunnel: TunnelContainer, tunnelConfiguration: TunnelConfiguration,
+                activateOnDemandSetting: ActivateOnDemandSetting, completionHandler: @escaping (TunnelManagementError?) -> Void) {
         let tunnelName = tunnelConfiguration.interface.name
         if tunnelName.isEmpty {
             completionHandler(TunnelManagementError.tunnelAlreadyExistsWithThatName)
@@ -138,13 +135,7 @@ class TunnelsManager {
         tunnelProviderManager.localizedDescription = tunnelName
         tunnelProviderManager.isEnabled = true
 
-        if (tunnelConfiguration.activationType == .activateManually) {
-            tunnelProviderManager.onDemandRules = []
-            tunnelProviderManager.isOnDemandEnabled = false
-        } else {
-            tunnelProviderManager.onDemandRules = onDemandRules(for: tunnelConfiguration.activationType)
-            tunnelProviderManager.isOnDemandEnabled = true
-        }
+        activateOnDemandSetting.apply(on: tunnelProviderManager)
 
         tunnelProviderManager.saveToPreferences { [weak self] (error) in
             defer { self?.isModifyingTunnel = false }
@@ -229,26 +220,6 @@ class TunnelsManager {
             t.refreshConnectionStatus()
         }
     }
-
-    func onDemandRules(for activationType: ActivationType) -> [NEOnDemandRule] {
-        switch (activationType) {
-        case .activateManually: return []
-        case .useOnDemandOverWifiAndCellular:
-            return [NEOnDemandRuleConnect()]
-        case .useOnDemandOverWifiOnly:
-            let connectOnWifiRule = NEOnDemandRuleConnect()
-            connectOnWifiRule.interfaceTypeMatch = .wiFi
-            let disconnectOnCellularRule = NEOnDemandRuleDisconnect()
-            disconnectOnCellularRule.interfaceTypeMatch = .cellular
-            return [connectOnWifiRule, disconnectOnCellularRule]
-        case .useOnDemandOverCellularOnly:
-            let connectOnCellularRule = NEOnDemandRuleConnect()
-            connectOnCellularRule.interfaceTypeMatch = .cellular
-            let disconnectOnWifiRule = NEOnDemandRuleDisconnect()
-            disconnectOnWifiRule.interfaceTypeMatch = .wiFi
-            return [connectOnCellularRule, disconnectOnWifiRule]
-        }
-    }
 }
 
 class TunnelContainer: NSObject {
@@ -275,6 +246,10 @@ class TunnelContainer: NSObject {
         return (tunnelProvider.protocolConfiguration as! NETunnelProviderProtocol).tunnelConfiguration()
     }
 
+    func activateOnDemandSetting() -> ActivateOnDemandSetting {
+        return ActivateOnDemandSetting(from: tunnelProvider)
+    }
+
     func refreshConnectionStatus() {
         let status = TunnelStatus(from: self.tunnelProvider.connection.status)
         self.status = status