Merge branch 'packet-tunnel-ipc'

2 files changed, 171 insertions, 0 deletions

diff --git a/ios/MullvadVPN/PacketTunnelIpc.swift b/ios/MullvadVPN/PacketTunnelIpc.swift
new file mode 100644
index 0000000000..4da14d4051
--- /dev/null
+++ b/ios/MullvadVPN/PacketTunnelIpc.swift
@@ -0,0 +1,147 @@
+//
+//  PacketTunnelIpc.swift
+//  MullvadVPN
+//
+//  Created by pronebird on 01/11/2019.
+//  Copyright © 2019 Amagicom AB. All rights reserved.
+//
+
+import Combine
+import Foundation
+import NetworkExtension
+
+/// A enum describing the kinds of requests that `PacketTunnelProvider` handles
+enum PacketTunnelRequest: Int, Codable {
+    /// Request the tunnel to reload the configuration
+    case reloadConfiguration
+
+    /// Request the tunnel to return the connection information
+    case tunnelInformation
+}
+
+enum PacketTunnelIpcError: Error {
+    /// A failure to encode the request
+    case encoding(Error)
+
+    /// A failure to decode the response
+    case decoding(Error)
+
+    /// A failure to send the IPC request
+    case send(Error)
+
+    /// A failure that's raised when the IPC response does not contain any data however the decoder
+    /// expected to receive data for decoding
+    case nilResponse
+
+    var localizedDescription: String {
+        switch self {
+        case .encoding(let error):
+            return "Encoding failure: \(error.localizedDescription)"
+        case .decoding(let error):
+            return "Decoding failure: \(error.localizedDescription)"
+        case .send(let error):
+            return "Submission failure: \(error.localizedDescription)"
+        case .nilResponse:
+            return "Unexpected nil response from the tunnel"
+        }
+    }
+}
+
+/// A struct that holds the basic information regarding the tunnel connection
+struct TunnelConnectionInfo: Codable, Equatable {
+    let ipv4Relay: String
+    let ipv6Relay: String?
+    let hostname: String
+}
+
+extension TunnelConnectionInfo: CustomDebugStringConvertible {
+    var debugDescription: String {
+        return "{ ipv4Relay: \(String(reflecting: ipv4Relay)), " +
+               "ipv6Relay: \(String(reflecting: ipv6Relay)), " +
+               "hostname: \(String(reflecting: hostname)) }"
+    }
+}
+
+enum PacketTunnelIpcHandlerError: Error {
+    /// A failure to encode the request
+    case encoding(Error)
+
+    /// A failure to decode the response
+    case decoding(Error)
+
+    /// A failure to process the request
+    case processing(Error)
+}
+
+enum PacketTunnelIpcHandler {}
+
+extension PacketTunnelIpcHandler {
+
+    static func decodeRequest(messageData: Data) -> AnyPublisher<PacketTunnelRequest, PacketTunnelIpcHandlerError> {
+        return Just(messageData)
+            .setFailureType(to: PacketTunnelIpcHandlerError.self)
+            .decode(type: PacketTunnelRequest.self, decoder: JSONDecoder())
+            .mapError { PacketTunnelIpcHandlerError.decoding($0) }
+            .eraseToAnyPublisher()
+    }
+
+    static func encodeResponse<T>(response: T) -> AnyPublisher<Data, PacketTunnelIpcHandlerError> where T: Encodable {
+        return Just(response)
+            .setFailureType(to: PacketTunnelIpcHandlerError.self)
+            .encode(encoder: JSONEncoder())
+            .mapError { PacketTunnelIpcHandlerError.encoding($0) }
+            .eraseToAnyPublisher()
+    }
+}
+
+class PacketTunnelIpc {
+    let session: NETunnelProviderSession
+
+    init(session: NETunnelProviderSession) {
+        self.session = session
+    }
+
+    func reloadConfiguration() -> AnyPublisher<(), PacketTunnelIpcError> {
+        return send(message: .reloadConfiguration)
+    }
+
+    func getTunnelInformation() -> AnyPublisher<TunnelConnectionInfo, PacketTunnelIpcError> {
+        return send(message: .tunnelInformation)
+    }
+
+    private func send(message: PacketTunnelRequest) -> AnyPublisher<(), PacketTunnelIpcError> {
+        return sendWithoutDecoding(message: message)
+            .map { _ in () }.eraseToAnyPublisher()
+    }
+
+    private func send<T>(message: PacketTunnelRequest) -> AnyPublisher<T, PacketTunnelIpcError> where T: Decodable {
+        return sendWithoutDecoding(message: message)
+            .replaceNil(with: .nilResponse)
+            .decode(type: T.self, decoder: JSONDecoder())
+            .mapError { PacketTunnelIpcError.decoding($0) }
+            .eraseToAnyPublisher()
+    }
+
+    private func sendWithoutDecoding(message: PacketTunnelRequest) -> AnyPublisher<Data?, PacketTunnelIpcError> {
+        return Just(message)
+            .setFailureType(to: PacketTunnelIpcError.self)
+            .encode(encoder: JSONEncoder())
+            .mapError { PacketTunnelIpcError.encoding($0) }
+            .flatMap(self.sendProviderMessage)
+            .mapError { PacketTunnelIpcError.send($0) }
+            .eraseToAnyPublisher()
+    }
+
+    private func sendProviderMessage(_ messageData: Data) -> Future<Data?, Error> {
+        return Future { (fulfill) in
+            do {
+                try self.session.sendProviderMessage(messageData, responseHandler: { (response) in
+                    fulfill(.success(response))
+                })
+            } catch {
+                fulfill(.failure(error))
+            }
+        }
+    }
+
+}
diff --git a/ios/MullvadVPN/ReplaceNilWithError.swift b/ios/MullvadVPN/ReplaceNilWithError.swift
new file mode 100644
index 0000000000..4097b007f0
--- /dev/null
+++ b/ios/MullvadVPN/ReplaceNilWithError.swift
@@ -0,0 +1,24 @@
+//
+//  ReplaceNilWithError.swift
+//  MullvadVPN
+//
+//  Created by pronebird on 19/11/2019.
+//  Copyright © 2019 Amagicom AB. All rights reserved.
+//
+
+import Combine
+import Foundation
+
+extension Publisher {
+
+    /// Replace nil elements with the provided error
+    func replaceNil<T>(with error: Failure) -> Publishers.FlatMap<Result<T, Failure>.Publisher, Self>
+        where Output == T?, Failure: Error {
+        return flatMap { (output: T?) -> Result<T, Failure>.Publisher in
+            let result: Result<T, Failure> = output.flatMap { .success($0) } ?? .failure(error)
+
+            return result.publisher
+        }
+    }
+
+}