[AltServer] Moves core ConnectionManager logic to AltKit

Refactors ConnectionManager to use arbitrary RequestHandlers and ConnectionHandlers. This allows the core AltServer request logic to be shared across different targets with different connection types.

AltKit/AltKit.h

@@ -8,5 +8,6 @@
 
 #import "NSError+ALTServerError.h"
 #import "CFNotificationName+AltStore.h"
+#import "ALTConnection.h"
 
 extern uint16_t ALTDeviceListeningSocket;

AltKit/Connections/ALTConnection.h

@@ -0,0 +1,23 @@
+//
+//  ALTConnection.h
+//  AltKit
+//
+//  Created by Riley Testut on 6/1/20.
+//  Copyright © 2020 Riley Testut. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+NS_SWIFT_NAME(Connection)
+@protocol ALTConnection <NSObject>
+
+- (void)sendData:(NSData *)data completionHandler:(void (^)(BOOL, NSError * _Nullable))completionHandler NS_REFINED_FOR_SWIFT;
+- (void)receiveDataWithExpectedSize:(NSInteger)expectedSize completionHandler:(void (^)(NSData * _Nullable, NSError * _Nullable))completionHandler NS_SWIFT_NAME(__receiveData(expectedSize:completionHandler:));
+
+- (void)disconnect;
+
+@end
+
+NS_ASSUME_NONNULL_END

AltKit/Connections/Connection.swift

@@ -0,0 +1,113 @@
+//
+//  Connection.swift
+//  AltKit
+//
+//  Created by Riley Testut on 6/1/20.
+//  Copyright © 2020 Riley Testut. All rights reserved.
+//
+
+import Foundation
+import Network
+
+public extension Connection
+{
+    func send(_ data: Data, completionHandler: @escaping (Result<Void, ALTServerError>) -> Void)
+    {
+        self.__send(data) { (success, error) in
+            let result = Result(success, error).mapError { (error) -> ALTServerError in
+                guard let nwError = error as? NWError else { return ALTServerError(error) }
+                return ALTServerError(.lostConnection, underlyingError: nwError)
+            }
+            
+            completionHandler(result)
+        }
+    }
+    
+    func receiveData(expectedSize: Int, completionHandler: @escaping (Result<Data, ALTServerError>) -> Void)
+    {
+        self.__receiveData(expectedSize: expectedSize) { (data, error) in
+            let result = Result(data, error).mapError { (error) -> ALTServerError in
+                guard let nwError = error as? NWError else { return ALTServerError(error) }
+                return ALTServerError(.lostConnection, underlyingError: nwError)
+            }
+            
+            completionHandler(result)
+        }
+    }
+    
+    func send<T: Encodable>(_ response: T, shouldDisconnect: Bool = false, completionHandler: @escaping (Result<Void, ALTServerError>) -> Void)
+    {
+        func finish(_ result: Result<Void, ALTServerError>)
+        {
+            completionHandler(result)
+            
+            if shouldDisconnect
+            {
+                // Add short delay to prevent us from dropping connection too quickly.
+                DispatchQueue.global().asyncAfter(deadline: .now() + 1.0) {
+                    self.disconnect()
+                }
+            }
+        }
+        
+        do
+        {
+            let data = try JSONEncoder().encode(response)
+            let responseSize = withUnsafeBytes(of: Int32(data.count)) { Data($0) }
+            
+            self.send(responseSize) { (result) in
+                switch result
+                {
+                case .failure(let error): finish(.failure(error))
+                case .success:
+                    self.send(data) { (result) in
+                        switch result
+                        {
+                        case .failure(let error): finish(.failure(error))
+                        case .success: finish(.success(()))
+                        }
+                    }
+                }
+            }
+        }
+        catch
+        {
+            finish(.failure(.init(.invalidResponse, underlyingError: error)))
+        }
+    }
+    
+    func receiveRequest(completionHandler: @escaping (Result<ServerRequest, ALTServerError>) -> Void)
+    {
+        let size = MemoryLayout<Int32>.size
+        
+        print("Receiving request size from connection:", self)
+        self.receiveData(expectedSize: size) { (result) in
+            do
+            {
+                let data = try result.get()
+                
+                let expectedSize = Int(data.withUnsafeBytes { $0.load(as: Int32.self) })
+                print("Receiving request from connection: \(self)... (\(expectedSize) bytes)")
+                
+                self.receiveData(expectedSize: expectedSize) { (result) in
+                    do
+                    {
+                        let data = try result.get()
+                        let request = try JSONDecoder().decode(ServerRequest.self, from: data)
+                        
+                        print("Received request:", request)
+                        completionHandler(.success(request))
+                    }
+                    catch
+                    {
+                        completionHandler(.failure(ALTServerError(error)))
+                    }
+                }
+            }
+            catch
+            {
+                completionHandler(.failure(ALTServerError(error)))
+            }
+        }
+    }
+}

AltKit/Connections/ConnectionManager.swift

@@ -0,0 +1,160 @@
+//
+//  ConnectionManager.swift
+//  AltServer
+//
+//  Created by Riley Testut on 5/23/19.
+//  Copyright © 2019 Riley Testut. All rights reserved.
+//
+
+import Foundation
+import Network
+
+public protocol RequestHandler
+{
+    func handleAnisetteDataRequest(_ request: AnisetteDataRequest, for connection: Connection, completionHandler: @escaping (Result<AnisetteDataResponse, Error>) -> Void)
+    func handlePrepareAppRequest(_ request: PrepareAppRequest, for connection: Connection, completionHandler: @escaping (Result<InstallationProgressResponse, Error>) -> Void)
+    
+    func handleInstallProvisioningProfilesRequest(_ request: InstallProvisioningProfilesRequest, for connection: Connection,
+                                                  completionHandler: @escaping (Result<InstallProvisioningProfilesResponse, Error>) -> Void)
+    func handleRemoveProvisioningProfilesRequest(_ request: RemoveProvisioningProfilesRequest, for connection: Connection,
+                                                 completionHandler: @escaping (Result<RemoveProvisioningProfilesResponse, Error>) -> Void)
+    
+    func handleRemoveAppRequest(_ request: RemoveAppRequest, for connection: Connection, completionHandler: @escaping (Result<RemoveAppResponse, Error>) -> Void)
+}
+
+public protocol ConnectionHandler: AnyObject
+{
+    var connectionHandler: ((Connection) -> Void)? { get set }
+    var disconnectionHandler: ((Connection) -> Void)? { get set }
+    
+    func startListening()
+    func stopListening()
+}
+
+public class ConnectionManager<RequestHandlerType: RequestHandler>
+{
+    public let requestHandler: RequestHandlerType
+    public let connectionHandlers: [ConnectionHandler]
+    
+    public var isStarted = false
+    
+    private var connections = [Connection]()
+    
+    public init(requestHandler: RequestHandlerType, connectionHandlers: [ConnectionHandler])
+    {
+        self.requestHandler = requestHandler
+        self.connectionHandlers = connectionHandlers
+        
+        for handler in connectionHandlers
+        {
+            handler.connectionHandler = { [weak self] (connection) in
+                self?.prepare(connection)
+            }
+            
+            handler.disconnectionHandler = { [weak self] (connection) in
+                self?.disconnect(connection)
+            }
+        }
+    }
+    
+    public func start()
+    {
+        guard !self.isStarted else { return }
+        
+        for connectionHandler in self.connectionHandlers
+        {
+            connectionHandler.startListening()
+        }
+        
+        self.isStarted = true
+    }
+    
+    public func stop()
+    {
+        guard self.isStarted else { return }
+        
+        for connectionHandler in self.connectionHandlers
+        {
+            connectionHandler.stopListening()
+        }
+        
+        self.isStarted = false
+    }
+}
+
+private extension ConnectionManager
+{
+    func prepare(_ connection: Connection)
+    {
+        guard !self.connections.contains(where: { $0 === connection }) else { return }
+        self.connections.append(connection)
+        
+        self.handleRequest(for: connection)
+    }
+    
+    func disconnect(_ connection: Connection)
+    {
+        guard let index = self.connections.firstIndex(where: { $0 === connection }) else { return }
+        self.connections.remove(at: index)
+    }
+    
+    func handleRequest(for connection: Connection)
+    {
+        func finish<T: ServerMessageProtocol>(_ result: Result<T, Error>)
+        {
+            do
+            {
+                let response = try result.get()
+                connection.send(response, shouldDisconnect: true) { (result) in
+                    print("Sent response \(response) with result:", result)
+                }
+            }
+            catch
+            {
+                let response = ErrorResponse(error: ALTServerError(error))
+                connection.send(response, shouldDisconnect: true) { (result) in
+                    print("Sent error response \(response) with result:", result)
+                }
+            }
+        }
+        
+        connection.receiveRequest() { (result) in
+            print("Received request with result:", result)
+            
+            switch result
+            {
+            case .failure(let error): finish(Result<ErrorResponse, Error>.failure(error))
+                
+            case .success(.anisetteData(let request)):
+                self.requestHandler.handleAnisetteDataRequest(request, for: connection) { (result) in
+                    finish(result)
+                }
+                
+            case .success(.prepareApp(let request)):
+                self.requestHandler.handlePrepareAppRequest(request, for: connection) { (result) in
+                    finish(result)
+                }
+                
+            case .success(.beginInstallation): break
+                
+            case .success(.installProvisioningProfiles(let request)):
+                self.requestHandler.handleInstallProvisioningProfilesRequest(request, for: connection) { (result) in
+                    finish(result)
+                }
+                
+            case .success(.removeProvisioningProfiles(let request)):
+                self.requestHandler.handleRemoveProvisioningProfilesRequest(request, for: connection) { (result) in
+                    finish(result)
+                }
+                
+            case .success(.removeApp(let request)):
+                self.requestHandler.handleRemoveAppRequest(request, for: connection) { (result) in
+                    finish(result)
+                }
+                
+            case .success(.unknown):
+                finish(Result<ErrorResponse, Error>.failure(ALTServerError(.unknownRequest)))
+            }
+        }
+    }
+}

AltKit/Connections/NetworkConnection.swift

@@ -0,0 +1,50 @@
+//
+//  NetworkConnection.swift
+//  AltKit
+//
+//  Created by Riley Testut on 6/1/20.
+//  Copyright © 2020 Riley Testut. All rights reserved.
+//
+
+import Foundation
+import Network
+
+public class NetworkConnection: NSObject, Connection
+{
+    public let nwConnection: NWConnection
+    
+    public init(_ nwConnection: NWConnection)
+    {
+        self.nwConnection = nwConnection
+    }
+    
+    public func __send(_ data: Data, completionHandler: @escaping (Bool, Error?) -> Void)
+    {
+        self.nwConnection.send(content: data, completion: .contentProcessed { (error) in
+            completionHandler(error == nil, error)
+        })
+    }
+    
+    public func __receiveData(expectedSize: Int, completionHandler: @escaping (Data?, Error?) -> Void)
+    {
+        self.nwConnection.receive(minimumIncompleteLength: expectedSize, maximumLength: expectedSize) { (data, context, isComplete, error) in
+            completionHandler(data, error)
+        }
+    }
+    
+    public func disconnect()
+    {
+        switch self.nwConnection.state
+        {
+        case .cancelled, .failed: break
+        default: self.nwConnection.cancel()
+        }
+    }
+}
+
+extension NetworkConnection
+{
+    override public var description: String {
+        return "\(self.nwConnection.endpoint) (Network)"
+    }
+}

AltKit/Extensions/ALTServerError+Conveniences.swift

@@ -0,0 +1,36 @@
+//
+//  ALTServerError+Conveniences.swift
+//  AltKit
+//
+//  Created by Riley Testut on 6/4/20.
+//  Copyright © 2020 Riley Testut. All rights reserved.
+//
+
+import Foundation
+
+public extension ALTServerError
+{
+    init<E: Error>(_ error: E)
+    {
+        switch error
+        {
+        case let error as ALTServerError: self = error
+        case is DecodingError: self = ALTServerError(.invalidRequest, underlyingError: error)
+        case is EncodingError: self = ALTServerError(.invalidResponse, underlyingError: error)
+        case let error as NSError:
+            var userInfo = error.userInfo
+            if !userInfo.keys.contains(NSUnderlyingErrorKey)
+            {
+                // Assign underlying error (if there isn't already one).
+                userInfo[NSUnderlyingErrorKey] = error
+            }
+            
+            self = ALTServerError(.unknown, userInfo: error.userInfo)
+        }
+    }
+    
+    init<E: Error>(_ code: ALTServerError.Code, underlyingError: E)
+    {
+        self = ALTServerError(.invalidRequest, userInfo: [NSUnderlyingErrorKey: underlyingError])
+    }
+}