Model for an endpoint

Signed-off-by: Roopesh Chander <roop@roopc.net>

WireGuard/WireGuard.xcodeproj/project.pbxproj

@@ -7,6 +7,7 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		6F693A562179E556008551C1 /* Endpoint.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6F693A552179E556008551C1 /* Endpoint.swift */; };
 		6F7774E1217181B1006A79B3 /* MainViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6F7774DF217181B1006A79B3 /* MainViewController.swift */; };
 		6F7774E2217181B1006A79B3 /* AppDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6F7774E0217181B1006A79B3 /* AppDelegate.swift */; };
 		6F7774E421718281006A79B3 /* TunnelsListTableViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = 6F7774E321718281006A79B3 /* TunnelsListTableViewController.swift */; };
@@ -19,6 +20,7 @@
 /* End PBXBuildFile section */
 
 /* Begin PBXFileReference section */
+		6F693A552179E556008551C1 /* Endpoint.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = Endpoint.swift; sourceTree = "<group>"; };
 		6F7774DF217181B1006A79B3 /* MainViewController.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = MainViewController.swift; sourceTree = "<group>"; };
 		6F7774E0217181B1006A79B3 /* AppDelegate.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = AppDelegate.swift; sourceTree = "<group>"; };
 		6F7774E321718281006A79B3 /* TunnelsListTableViewController.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = TunnelsListTableViewController.swift; sourceTree = "<group>"; };
@@ -69,6 +71,7 @@
 			children = (
 				6F7774E72172020C006A79B3 /* Configuration.swift */,
 				6F7774E9217229DB006A79B3 /* IPAddressRange.swift */,
+				6F693A552179E556008551C1 /* Endpoint.swift */,
 			);
 			path = Model;
 			sourceTree = "<group>";
@@ -198,6 +201,7 @@
 			files = (
 				6F7774E421718281006A79B3 /* TunnelsListTableViewController.swift in Sources */,
 				6F7774EF21722D97006A79B3 /* TunnelsManager.swift in Sources */,
+				6F693A562179E556008551C1 /* Endpoint.swift in Sources */,
 				6F7774E2217181B1006A79B3 /* AppDelegate.swift in Sources */,
 				6F7774EA217229DB006A79B3 /* IPAddressRange.swift in Sources */,
 				6F7774E82172020C006A79B3 /* Configuration.swift in Sources */,

WireGuard/WireGuard/Model/Endpoint.swift

@@ -0,0 +1,79 @@
+//
+//  Endpoint.swift
+//  WireGuard
+//
+//  Created by Roopesh Chander on 19/10/18.
+//  Copyright © 2018 WireGuard LLC. All rights reserved.
+//
+
+import Foundation
+import Network
+
+@available(OSX 10.14, iOS 12.0, *)
+struct Endpoint {
+    let host: NWEndpoint.Host
+    let port: NWEndpoint.Port
+}
+
+// MARK: Converting to and from String
+// For use in the UI
+
+extension Endpoint {
+    init?(from string: String) {
+        // Separation of host and port is based on 'parse_endpoint' function in
+        // https://git.zx2c4.com/WireGuard/tree/src/tools/config.c
+        guard (!string.isEmpty) else { return nil }
+        if (string.first! == "[") {
+            // Look for IPv6-style endpoint, like [::1]:80
+            let startOfHost = string.index(after: string.startIndex)
+            guard let endOfHost = string.dropFirst().firstIndex(of: "]") else { return nil }
+            let afterEndOfHost = string.index(after: endOfHost)
+            guard (string[afterEndOfHost] == ":") else { return nil }
+            let startOfPort = string.index(after: afterEndOfHost)
+            let hostString = String(string[startOfHost ..< endOfHost])
+            guard let endpointPort = NWEndpoint.Port(String(string[startOfPort ..< string.endIndex])) else { return nil }
+            host = NWEndpoint.Host(hostString)
+            port = endpointPort
+        } else {
+            // Look for an IPv4-style endpoint, like 127.0.0.1:80
+            guard let endOfHost = string.firstIndex(of: ":") else { return nil }
+            let startOfPort = string.index(after: endOfHost)
+            let hostString = String(string[string.startIndex ..< endOfHost])
+            guard let endpointPort = NWEndpoint.Port(String(string[startOfPort ..< string.endIndex])) else { return nil }
+            host = NWEndpoint.Host(hostString)
+            port = endpointPort
+        }
+    }
+    func stringRepresentation() -> String {
+        switch (host) {
+        case .name(let hostname, _):
+            return "\(hostname):\(port)"
+        case .ipv4(let address):
+            return "\(address):\(port)"
+        case .ipv6(let address):
+            return "[\(address)]:\(port)"
+        }
+    }
+}
+
+// MARK: Codable
+// For serializing to disk
+
+@available(OSX 10.14, iOS 12.0, *)
+extension Endpoint: Codable {
+    public func encode(to encoder: Encoder) throws {
+        var container = encoder.singleValueContainer()
+        try container.encode(self.stringRepresentation())
+    }
+    public init(from decoder: Decoder) throws {
+        let container = try decoder.singleValueContainer()
+        let endpointString = try container.decode(String.self)
+        guard let endpoint = Endpoint(from: endpointString) else {
+            throw DecodingError.invalidData
+        }
+        self = endpoint
+    }
+    enum DecodingError: Error {
+        case invalidData
+    }
+}