From 22625e8cc4792a71174af5fc69f0f63ba4b808d8 Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Thu, 24 Jan 2019 00:00:46 +0100
Subject: Tunnel: support getting runtime configuration

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
 .../Tunnel/TunnelConfiguration+UapiConfig.swift    | 207 +++++++++++++++++++++
 WireGuard/WireGuard/Tunnel/TunnelsManager.swift    |  17 ++
 2 files changed, 224 insertions(+)
 create mode 100644 WireGuard/WireGuard/Tunnel/TunnelConfiguration+UapiConfig.swift

(limited to 'WireGuard/WireGuard/Tunnel')

diff --git a/WireGuard/WireGuard/Tunnel/TunnelConfiguration+UapiConfig.swift b/WireGuard/WireGuard/Tunnel/TunnelConfiguration+UapiConfig.swift
new file mode 100644
index 0000000..63a8570
--- /dev/null
+++ b/WireGuard/WireGuard/Tunnel/TunnelConfiguration+UapiConfig.swift
@@ -0,0 +1,207 @@
+// SPDX-License-Identifier: MIT
+// Copyright © 2018-2019 WireGuard LLC. All Rights Reserved.
+
+import Foundation
+
+extension TunnelConfiguration {
+    //swiftlint:disable:next function_body_length cyclomatic_complexity
+    convenience init(fromUapiConfig uapiConfig: String, basedOn base: TunnelConfiguration? = nil) throws {
+        var interfaceConfiguration: InterfaceConfiguration?
+        var peerConfigurations = [PeerConfiguration]()
+
+        var lines = uapiConfig.split(separator: "\n")
+        lines.append("")
+
+        var parserState = ParserState.inInterfaceSection
+        var attributes = [String: String]()
+
+        for line in lines {
+            var key = ""
+            var value = ""
+
+            if !line.isEmpty {
+                guard let equalsIndex = line.firstIndex(of: "=") else { throw ParseError.invalidLine(line) }
+                key = String(line[..<equalsIndex])
+                value = String(line[line.index(equalsIndex, offsetBy: 1)...])
+            }
+
+            if line.isEmpty || key == "public_key" {
+                // Previous section has ended; process the attributes collected so far
+                if parserState == .inInterfaceSection {
+                    let interface = try TunnelConfiguration.collate(interfaceAttributes: attributes)
+                    guard interfaceConfiguration == nil else { throw ParseError.multipleInterfaces }
+                    interfaceConfiguration = interface
+                    parserState = .inPeerSection
+                } else if parserState == .inPeerSection {
+                    let peer = try TunnelConfiguration.collate(peerAttributes: attributes)
+                    peerConfigurations.append(peer)
+                }
+                attributes.removeAll()
+                if line.isEmpty {
+                    break
+                }
+            }
+
+            if let presentValue = attributes[key] {
+                if key == "allowed_ip" {
+                    attributes[key] = presentValue + "," + value
+                } else {
+                    throw ParseError.multipleEntriesForKey(key)
+                }
+            } else {
+                attributes[key] = value
+            }
+
+            let interfaceSectionKeys: Set<String> = ["private_key", "listen_port", "fwmark"]
+            let peerSectionKeys: Set<String> = ["public_key", "preshared_key", "allowed_ip", "endpoint", "persistent_keepalive_interval", "last_handshake_time_sec", "last_handshake_time_nsec", "rx_bytes", "tx_bytes", "protocol_version"]
+
+            if parserState == .inInterfaceSection {
+                guard interfaceSectionKeys.contains(key) else {
+                    throw ParseError.interfaceHasUnrecognizedKey(key)
+                }
+            }
+            if parserState == .inPeerSection {
+                guard peerSectionKeys.contains(key) else {
+                    throw ParseError.peerHasUnrecognizedKey(key)
+                }
+            }
+        }
+
+        let peerPublicKeysArray = peerConfigurations.map { $0.publicKey }
+        let peerPublicKeysSet = Set<Data>(peerPublicKeysArray)
+        if peerPublicKeysArray.count != peerPublicKeysSet.count {
+            throw ParseError.multiplePeersWithSamePublicKey
+        }
+
+        interfaceConfiguration?.addresses = base?.interface.addresses ?? []
+        interfaceConfiguration?.dns = base?.interface.dns ?? []
+        interfaceConfiguration?.mtu = base?.interface.mtu
+
+        if let interfaceConfiguration = interfaceConfiguration {
+            self.init(name: base?.name, interface: interfaceConfiguration, peers: peerConfigurations)
+        } else {
+            throw ParseError.noInterface
+        }
+    }
+
+    private static func collate(interfaceAttributes attributes: [String: String]) throws -> InterfaceConfiguration {
+        guard let privateKeyString = attributes["private_key"] else {
+            throw ParseError.interfaceHasNoPrivateKey
+        }
+        guard let privateKey = Data(hexEncoded: privateKeyString), privateKey.count == TunnelConfiguration.keyLength else {
+            throw ParseError.interfaceHasInvalidPrivateKey(privateKeyString)
+        }
+        var interface = InterfaceConfiguration(privateKey: privateKey)
+        if let listenPortString = attributes["listen_port"] {
+            guard let listenPort = UInt16(listenPortString) else {
+                throw ParseError.interfaceHasInvalidListenPort(listenPortString)
+            }
+            if listenPort != 0 {
+                interface.listenPort = listenPort
+            }
+        }
+        return interface
+    }
+
+    //swiftlint:disable:next cyclomatic_complexity
+    private static func collate(peerAttributes attributes: [String: String]) throws -> PeerConfiguration {
+        guard let publicKeyString = attributes["public_key"] else {
+            throw ParseError.peerHasNoPublicKey
+        }
+        guard let publicKey = Data(hexEncoded: publicKeyString), publicKey.count == TunnelConfiguration.keyLength else {
+            throw ParseError.peerHasInvalidPublicKey(publicKeyString)
+        }
+        var peer = PeerConfiguration(publicKey: publicKey)
+        if let preSharedKeyString = attributes["preshared_key"] {
+            guard let preSharedKey = Data(hexEncoded: preSharedKeyString), preSharedKey.count == TunnelConfiguration.keyLength else {
+                throw ParseError.peerHasInvalidPreSharedKey(preSharedKeyString)
+            }
+            // TODO(zx2c4): does the compiler optimize this away?
+            var accumulator: UInt8 = 0
+            for index in 0..<preSharedKey.count {
+                accumulator |= preSharedKey[index]
+            }
+            if accumulator != 0 {
+                peer.preSharedKey = preSharedKey
+            }
+        }
+        if let allowedIPsString = attributes["allowed_ip"] {
+            var allowedIPs = [IPAddressRange]()
+            for allowedIPString in allowedIPsString.splitToArray(trimmingCharacters: .whitespacesAndNewlines) {
+                guard let allowedIP = IPAddressRange(from: allowedIPString) else {
+                    throw ParseError.peerHasInvalidAllowedIP(allowedIPString)
+                }
+                allowedIPs.append(allowedIP)
+            }
+            peer.allowedIPs = allowedIPs
+        }
+        if let endpointString = attributes["endpoint"] {
+            guard let endpoint = Endpoint(from: endpointString) else {
+                throw ParseError.peerHasInvalidEndpoint(endpointString)
+            }
+            peer.endpoint = endpoint
+        }
+        if let persistentKeepAliveString = attributes["persistent_keepalive_interval"] {
+            guard let persistentKeepAlive = UInt16(persistentKeepAliveString) else {
+                throw ParseError.peerHasInvalidPersistentKeepAlive(persistentKeepAliveString)
+            }
+            if persistentKeepAlive != 0 {
+                peer.persistentKeepAlive = persistentKeepAlive
+            }
+        }
+        if let rxBytesString = attributes["rx_bytes"] {
+            guard let rxBytes = UInt64(rxBytesString) else {
+                throw ParseError.peerHasInvalidTransferBytes(rxBytesString)
+            }
+            if rxBytes != 0 {
+                peer.rxBytes = rxBytes
+            }
+        }
+        if let txBytesString = attributes["tx_bytes"] {
+            guard let txBytes = UInt64(txBytesString) else {
+                throw ParseError.peerHasInvalidTransferBytes(txBytesString)
+            }
+            if txBytes != 0 {
+                peer.txBytes = txBytes
+            }
+        }
+        if let lastHandshakeTimeSecString = attributes["last_handshake_time_sec"] {
+            var lastHandshakeTimeSince1970: TimeInterval = 0
+            guard let lastHandshakeTimeSec = UInt64(lastHandshakeTimeSecString) else {
+                throw ParseError.peerHasInvalidLastHandshakeTime(lastHandshakeTimeSecString)
+            }
+            if lastHandshakeTimeSec != 0 {
+                lastHandshakeTimeSince1970 += Double(lastHandshakeTimeSec)
+                if let lastHandshakeTimeNsecString = attributes["last_handshake_time_nsec"] {
+                    guard let lastHandshakeTimeNsec = UInt64(lastHandshakeTimeNsecString) else {
+                        throw ParseError.peerHasInvalidLastHandshakeTime(lastHandshakeTimeNsecString)
+                    }
+                    lastHandshakeTimeSince1970 += Double(lastHandshakeTimeNsec) / 1000000000.0
+                }
+                peer.lastHandshakeTime = Date(timeIntervalSince1970: lastHandshakeTimeSince1970)
+            }
+        }
+        return peer
+    }
+}
+
+extension Data {
+    //swiftlint:disable identifier_name
+    init?(hexEncoded hexString: String) {
+        if hexString.count % 2 != 0 {
+            return nil
+        }
+        let len = hexString.count / 2
+        self.init(capacity: len)
+        for i in 0..<len {
+            let j = hexString.index(hexString.startIndex, offsetBy: i * 2)
+            let k = hexString.index(j, offsetBy: 2)
+            let bytes = hexString[j..<k]
+            if var num = UInt8(bytes, radix: 16) {
+                append(&num, count: 1)
+            } else {
+                return nil
+            }
+        }
+    }
+}
diff --git a/WireGuard/WireGuard/Tunnel/TunnelsManager.swift b/WireGuard/WireGuard/Tunnel/TunnelsManager.swift
index 75d8230..5e6ad5c 100644
--- a/WireGuard/WireGuard/Tunnel/TunnelsManager.swift
+++ b/WireGuard/WireGuard/Tunnel/TunnelsManager.swift
@@ -397,6 +397,23 @@ class TunnelContainer: NSObject {
         super.init()
     }
 
+    func getRuntimeTunnelConfiguration(completionHandler: @escaping ((TunnelConfiguration?) -> Void)) {
+        guard status != .inactive, let session = tunnelProvider.connection as? NETunnelProviderSession else {
+            completionHandler(tunnelConfiguration)
+            return
+        }
+        guard nil != (try? session.sendProviderMessage(Data(bytes: [ 0 ]), responseHandler: {
+            guard self.status != .inactive, let data = $0, let base = self.tunnelConfiguration, let settings = String(data: data, encoding: .utf8) else {
+                completionHandler(self.tunnelConfiguration)
+                return
+            }
+            completionHandler((try? TunnelConfiguration(fromUapiConfig: settings, basedOn: base)) ?? self.tunnelConfiguration)
+        })) else {
+            completionHandler(tunnelConfiguration)
+            return
+        }
+    }
+
     func refreshStatus() {
         let status = TunnelStatus(from: tunnelProvider.connection.status)
         self.status = status
-- 
cgit v1.2.3-59-g8ed1b