// // Copyright © 2018 WireGuard LLC. All rights reserved. // import NetworkExtension import os.log enum PacketTunnelProviderError: Error { case tunnelSetupFailed } /// A packet tunnel provider object. class PacketTunnelProvider: NEPacketTunnelProvider { // MARK: Properties private var wgHandle: Int32? private var wgContext: WireGuardContext? private var config: NETunnelProviderProtocol { return self.protocolConfiguration as! NETunnelProviderProtocol // swiftlint:disable:this force_cast } private var interfaceName: String { return config.providerConfiguration![PCKeys.title.rawValue]! as! String // swiftlint:disable:this force_cast } private var settings: String { return config.providerConfiguration![PCKeys.settings.rawValue]! as! String // swiftlint:disable:this force_cast } // MARK: NEPacketTunnelProvider /// Begin the process of establishing the tunnel. override func startTunnel(options: [String: NSObject]?, completionHandler startTunnelCompletionHandler: @escaping (Error?) -> Void) { os_log("Starting tunnel", log: Log.general, type: .info) let validatedEndpoints = (config.providerConfiguration?[PCKeys.endpoints.rawValue] as? String ?? "").commaSeparatedToArray().compactMap { try? Endpoint(endpointString: String($0)) }.compactMap {$0} let validatedAddresses = (config.providerConfiguration?[PCKeys.addresses.rawValue] as? String ?? "").commaSeparatedToArray().compactMap { try? CIDRAddress(stringRepresentation: String($0)) }.compactMap { $0 } guard let firstEndpoint = validatedEndpoints.first else { startTunnelCompletionHandler(PacketTunnelProviderError.tunnelSetupFailed) return } configureLogger() wgContext = WireGuardContext(packetFlow: self.packetFlow) let handle = connect(interfaceName: interfaceName, settings: settings) if handle < 0 { startTunnelCompletionHandler(PacketTunnelProviderError.tunnelSetupFailed) return } wgHandle = handle // We use the first endpoint for the ipAddress let newSettings = NEPacketTunnelNetworkSettings(tunnelRemoteAddress: firstEndpoint.ipAddress) newSettings.tunnelOverheadBytes = 80 // IPv4 settings let validatedIPv4Addresses = validatedAddresses.filter { $0.addressType == .IPv4} if validatedIPv4Addresses.count > 0 { let ipv4Settings = NEIPv4Settings(addresses: validatedIPv4Addresses.map { $0.ipAddress }, subnetMasks: validatedIPv4Addresses.map { $0.subnetString }) ipv4Settings.includedRoutes = [NEIPv4Route.default()] ipv4Settings.excludedRoutes = validatedEndpoints.filter { $0.addressType == .IPv4}.map { NEIPv4Route(destinationAddress: $0.ipAddress, subnetMask: "255.255.255.255")} newSettings.ipv4Settings = ipv4Settings } // IPv6 settings let validatedIPv6Addresses = validatedAddresses.filter { $0.addressType == .IPv6} if validatedIPv6Addresses.count > 0 { let ipv6Settings = NEIPv6Settings(addresses: validatedIPv6Addresses.map { $0.ipAddress }, networkPrefixLengths: validatedIPv6Addresses.map { NSNumber(value: $0.subnet) }) ipv6Settings.includedRoutes = [NEIPv6Route.default()] ipv6Settings.excludedRoutes = validatedEndpoints.filter { $0.addressType == .IPv6}.map { NEIPv6Route(destinationAddress: $0.ipAddress, networkPrefixLength: 128)} newSettings.ipv6Settings = ipv6Settings } if let dns = config.providerConfiguration?[PCKeys.dns.rawValue] as? String { newSettings.dnsSettings = NEDNSSettings(servers: dns.commaSeparatedToArray()) } if let mtu = config.providerConfiguration![PCKeys.mtu.rawValue] as? NSNumber, mtu.intValue > 0 { newSettings.mtu = mtu } setTunnelNetworkSettings(newSettings) { (error) in if let error = error { os_log("Error setting network settings: %s", log: Log.general, type: .error, error.localizedDescription) startTunnelCompletionHandler(PacketTunnelProviderError.tunnelSetupFailed) } else { startTunnelCompletionHandler(nil /* No errors */) } } } /// Begin the process of stopping the tunnel. override func stopTunnel(with reason: NEProviderStopReason, completionHandler: @escaping () -> Void) { os_log("Stopping tunnel", log: Log.general, type: .info) if let handle = wgHandle { wgTurnOff(handle) } wgContext?.closeTunnel() completionHandler() } /// Handle IPC messages from the app. override func handleAppMessage(_ messageData: Data, completionHandler: ((Data?) -> Void)?) { let responseData: Data? switch ExtensionMessage(messageData) { case ExtensionMessage.requestVersion: responseData = (wgVersion().flatMap { String(cString: $0) } ?? "").data(using: .utf8) default: responseData = nil } completionHandler?(responseData) } private func configureLogger() { wgSetLogger { (level, tagCStr, msgCStr) in let logType: OSLogType switch level { case 0: logType = .debug case 1: logType = .info case 2: logType = .error default: logType = .default } let tag = (tagCStr != nil) ? String(cString: tagCStr!) : "" let msg = (msgCStr != nil) ? String(cString: msgCStr!) : "" os_log("wg log: %{public}s: %{public}s", log: Log.general, type: logType, tag, msg) } } private func connect(interfaceName: String, settings: String) -> Int32 { // swiftlint:disable:this cyclomatic_complexity return withStringsAsGoStrings(interfaceName, settings) { (nameGoStr, settingsGoStr) -> Int32 in return withUnsafeMutablePointer(to: &wgContext) { (wgCtxPtr) -> Int32 in return wgTurnOn(nameGoStr, settingsGoStr, { (wgCtxPtr, buf, len) -> Int in autoreleasepool { // read_fn: Read from the TUN interface and pass it on to WireGuard guard let wgCtxPtr = wgCtxPtr else { return 0 } guard let buf = buf else { return 0 } let wgContext = wgCtxPtr.bindMemory(to: WireGuardContext.self, capacity: 1).pointee var isTunnelClosed = false guard let packet = wgContext.readPacket(isTunnelClosed: &isTunnelClosed) else { return 0 } if isTunnelClosed { return -1 } let packetData = packet.data if packetData.count <= len { packetData.copyBytes(to: buf, count: packetData.count) return packetData.count } return 0 } }, { (wgCtxPtr, buf, len) -> Int in autoreleasepool { // write_fn: Receive packets from WireGuard and write to the TUN interface guard let wgCtxPtr = wgCtxPtr else { return 0 } guard let buf = buf else { return 0 } guard len > 0 else { return 0 } let wgContext = wgCtxPtr.bindMemory(to: WireGuardContext.self, capacity: 1).pointee let ipVersionBits = (buf[0] & 0xf0) >> 4 let ipVersion: sa_family_t? = { if ipVersionBits == 4 { return sa_family_t(AF_INET) } // IPv4 if ipVersionBits == 6 { return sa_family_t(AF_INET6) } // IPv6 return nil }() guard let protocolFamily = ipVersion else { fatalError("Unknown IP version") } let packet = NEPacket(data: Data(bytes: buf, count: len), protocolFamily: protocolFamily) var isTunnelClosed = false let isWritten = wgContext.writePacket(packet: packet, isTunnelClosed: &isTunnelClosed) if isTunnelClosed { return -1 } if isWritten { return len } return 0 } }, wgCtxPtr) } } } } class WireGuardContext { private var packetFlow: NEPacketTunnelFlow private var outboundPackets: [NEPacket] = [] private var isTunnelClosed: Bool = false private var readPacketCondition = NSCondition() init(packetFlow: NEPacketTunnelFlow) { self.packetFlow = packetFlow } func closeTunnel() { isTunnelClosed = true readPacketCondition.signal() } func packetsRead(packets: [NEPacket]) { readPacketCondition.lock() outboundPackets.append(contentsOf: packets) readPacketCondition.unlock() readPacketCondition.signal() } func readPacket(isTunnelClosed: inout Bool) -> NEPacket? { if outboundPackets.isEmpty { readPacketCondition.lock() packetFlow.readPacketObjects(completionHandler: packetsRead) while outboundPackets.isEmpty && !self.isTunnelClosed { readPacketCondition.wait() } readPacketCondition.unlock() } isTunnelClosed = self.isTunnelClosed if !outboundPackets.isEmpty { return outboundPackets.removeFirst() } return nil } func writePacket(packet: NEPacket, isTunnelClosed: inout Bool) -> Bool { isTunnelClosed = self.isTunnelClosed return packetFlow.writePacketObjects([packet]) } } private func withStringsAsGoStrings(_ str1: String, _ str2: String, closure: (gostring_t, gostring_t) -> R) -> R { return str1.withCString { (s1cStr) -> R in let gstr1 = gostring_t(p: s1cStr, n: str1.utf8.count) return str2.withCString { (s2cStr) -> R in let gstr2 = gostring_t(p: s2cStr, n: str2.utf8.count) return closure(gstr1, gstr2) } } }