From 56eed120200287b12e3bec391453d5a61f3436b4 Mon Sep 17 00:00:00 2001
From: Jeroen Leenarts <jeroen.leenarts@gmail.com>
Date: Tue, 28 Aug 2018 14:04:38 +0200
Subject: [PATCH] Move connection logic into seperate function.

---
 .../PacketTunnelProvider.swift                | 89 ++++++++++---------
 1 file changed, 46 insertions(+), 43 deletions(-)

diff --git a/WireGuardNetworkExtension/PacketTunnelProvider.swift b/WireGuardNetworkExtension/PacketTunnelProvider.swift
index b7a481e..07c33e5 100644
--- a/WireGuardNetworkExtension/PacketTunnelProvider.swift
+++ b/WireGuardNetworkExtension/PacketTunnelProvider.swift
@@ -46,49 +46,7 @@ class PacketTunnelProvider: NEPacketTunnelProvider {
 
         configureLogger()
 
-        let handle = withStringsAsGoStrings(interfaceName, settings) { (nameGoStr, settingsGoStr) -> Int32 in
-            return withUnsafeMutablePointer(to: &wgContext) { (wgCtxPtr) -> Int32 in
-                return wgTurnOn(nameGoStr, settingsGoStr,
-                                // read_fn: Read from the TUN interface and pass it on to WireGuard
-                    { (wgCtxPtr, buf, len) -> Int in
-                        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
-                },
-                    // write_fn: Receive packets from WireGuard and write to the TUN interface
-                    { (wgCtxPtr, buf, len) -> Int in
-                        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)
-            }
-        }
+        let handle = connect(interfaceName: interfaceName, settings: settings)
 
         if handle < 0 {
             startTunnelCompletionHandler(PacketTunnelProviderError.tunnelSetupFailed)
@@ -181,6 +139,51 @@ class PacketTunnelProvider: NEPacketTunnelProvider {
         }
     }
 
+    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,
+                                // read_fn: Read from the TUN interface and pass it on to WireGuard
+                    { (wgCtxPtr, buf, len) -> Int in
+                        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
+                },
+                    // write_fn: Receive packets from WireGuard and write to the TUN interface
+                    { (wgCtxPtr, buf, len) -> Int in
+                        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 {