From dd672d3dacfbb7974add2f40d836e51535a339a1 Mon Sep 17 00:00:00 2001 From: Roopesh Chander Date: Sat, 13 Oct 2018 06:25:43 +0530 Subject: Prepare for rewrite: Move WireGuardNetworkExtension into the new project folder Signed-off-by: Roopesh Chander --- .../PacketTunnelProvider.swift | 247 +++++++++++++++++++++ 1 file changed, 247 insertions(+) create mode 100644 WireGuard/WireGuardNetworkExtension/PacketTunnelProvider.swift (limited to 'WireGuard/WireGuardNetworkExtension/PacketTunnelProvider.swift') diff --git a/WireGuard/WireGuardNetworkExtension/PacketTunnelProvider.swift b/WireGuard/WireGuardNetworkExtension/PacketTunnelProvider.swift new file mode 100644 index 0000000..1480abc --- /dev/null +++ b/WireGuard/WireGuardNetworkExtension/PacketTunnelProvider.swift @@ -0,0 +1,247 @@ +// +// 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? + + let message = ExtensionMessage(messageData) + + switch message { + 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) + } + } +} -- cgit v1.2.3-59-g8ed1b