wireguard-apple/WireGuard/WireGuardNetworkExtension/PacketTunnelProvider.swift

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// SPDX-License-Identifier: MIT
// Copyright © 2018-2019 WireGuard LLC. All Rights Reserved.
import Foundation
import Network
import NetworkExtension
import os.log
class PacketTunnelProvider: NEPacketTunnelProvider {
private var handle: Int32?
private var networkMonitor: NWPathMonitor?
private var ifname: String?
private var packetTunnelSettingsGenerator: PacketTunnelSettingsGenerator?
deinit {
networkMonitor?.cancel()
}
override func startTunnel(options: [String: NSObject]?, completionHandler startTunnelCompletionHandler: @escaping (Error?) -> Void) {
let activationAttemptId = options?["activationAttemptId"] as? String
let errorNotifier = ErrorNotifier(activationAttemptId: activationAttemptId)
guard let tunnelProviderProtocol = protocolConfiguration as? NETunnelProviderProtocol,
let tunnelConfiguration = tunnelProviderProtocol.asTunnelConfiguration() else {
errorNotifier.notify(PacketTunnelProviderError.savedProtocolConfigurationIsInvalid)
startTunnelCompletionHandler(PacketTunnelProviderError.savedProtocolConfigurationIsInvalid)
return
}
configureLogger()
#if os(macOS)
wgEnableRoaming(true)
#endif
wg_log(.info, message: "Starting tunnel from the " + (activationAttemptId == nil ? "OS directly, rather than the app" : "app"))
let endpoints = tunnelConfiguration.peers.map { $0.endpoint }
guard let resolvedEndpoints = DNSResolver.resolveSync(endpoints: endpoints) else {
errorNotifier.notify(PacketTunnelProviderError.dnsResolutionFailure)
startTunnelCompletionHandler(PacketTunnelProviderError.dnsResolutionFailure)
return
}
assert(endpoints.count == resolvedEndpoints.count)
packetTunnelSettingsGenerator = PacketTunnelSettingsGenerator(tunnelConfiguration: tunnelConfiguration, resolvedEndpoints: resolvedEndpoints)
setTunnelNetworkSettings(packetTunnelSettingsGenerator!.generateNetworkSettings()) { error in
if let error = error {
wg_log(.error, message: "Starting tunnel failed with setTunnelNetworkSettings returning \(error.localizedDescription)")
errorNotifier.notify(PacketTunnelProviderError.couldNotSetNetworkSettings)
startTunnelCompletionHandler(PacketTunnelProviderError.couldNotSetNetworkSettings)
} else {
self.networkMonitor = NWPathMonitor()
self.networkMonitor!.pathUpdateHandler = self.pathUpdate
self.networkMonitor!.start(queue: DispatchQueue(label: "NetworkMonitor"))
let fileDescriptor = (self.packetFlow.value(forKeyPath: "socket.fileDescriptor") as? Int32) ?? -1
if fileDescriptor < 0 {
wg_log(.error, staticMessage: "Starting tunnel failed: Could not determine file descriptor")
errorNotifier.notify(PacketTunnelProviderError.couldNotDetermineFileDescriptor)
startTunnelCompletionHandler(PacketTunnelProviderError.couldNotDetermineFileDescriptor)
return
}
var ifnameSize = socklen_t(IFNAMSIZ)
let ifnamePtr = UnsafeMutablePointer<CChar>.allocate(capacity: Int(ifnameSize))
ifnamePtr.initialize(repeating: 0, count: Int(ifnameSize))
if getsockopt(fileDescriptor, 2 /* SYSPROTO_CONTROL */, 2 /* UTUN_OPT_IFNAME */, ifnamePtr, &ifnameSize) == 0 {
self.ifname = String(cString: ifnamePtr)
}
ifnamePtr.deallocate()
wg_log(.info, message: "Tunnel interface is \(self.ifname ?? "unknown")")
let handle = self.packetTunnelSettingsGenerator!.uapiConfiguration().withGoString { return wgTurnOn($0, fileDescriptor) }
if handle < 0 {
wg_log(.error, message: "Starting tunnel failed with wgTurnOn returning \(handle)")
errorNotifier.notify(PacketTunnelProviderError.couldNotStartBackend)
startTunnelCompletionHandler(PacketTunnelProviderError.couldNotStartBackend)
return
}
self.handle = handle
startTunnelCompletionHandler(nil)
}
}
}
override func stopTunnel(with reason: NEProviderStopReason, completionHandler: @escaping () -> Void) {
networkMonitor?.cancel()
networkMonitor = nil
ErrorNotifier.removeLastErrorFile()
wg_log(.info, staticMessage: "Stopping tunnel")
if let handle = handle {
wgTurnOff(handle)
}
completionHandler()
#if os(macOS)
// HACK: This is a filthy hack to work around Apple bug 32073323 (dup'd by us as 47526107).
// Remove it when they finally fix this upstream and the fix has been rolled out to
// sufficient quantities of users.
exit(0)
#endif
}
override func handleAppMessage(_ messageData: Data, completionHandler: ((Data?) -> Void)? = nil) {
guard let completionHandler = completionHandler else { return }
guard let handle = handle else {
completionHandler(nil)
return
}
if messageData.count == 1 && messageData[0] == 0 {
guard let settings = wgGetConfig(handle) else {
completionHandler(nil)
return
}
completionHandler(String(cString: settings).data(using: .utf8)!)
free(settings)
} else {
completionHandler(nil)
}
}
private func configureLogger() {
Logger.configureGlobal(tagged: "NET", withFilePath: FileManager.logFileURL?.path)
wgSetLogger { level, msgC in
guard let msgC = msgC else { return }
let logType: OSLogType
switch level {
case 0:
logType = .debug
case 1:
logType = .info
case 2:
logType = .error
default:
logType = .default
}
wg_log(logType, message: String(cString: msgC))
}
}
private func pathUpdate(path: Network.NWPath) {
guard let handle = handle else { return }
wg_log(.debug, message: "Network change detected with \(path.status) route and interface order \(path.availableInterfaces)")
#if os(iOS)
if let packetTunnelSettingsGenerator = packetTunnelSettingsGenerator {
_ = packetTunnelSettingsGenerator.endpointUapiConfiguration().withGoString { return wgSetConfig(handle, $0) }
}
#endif
wgBumpSockets(handle)
}
}
extension String {
func withGoString<R>(_ call: (gostring_t) -> R) -> R {
func helper(_ pointer: UnsafePointer<Int8>?, _ call: (gostring_t) -> R) -> R {
return call(gostring_t(p: pointer, n: utf8.count))
}
return helper(self, call)
}
}