// // Copyright 2012 Square Inc. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. // #import "HippySRWebSocket.h" #import #import #import #import "HippyAssert.h" #import "HippyLog.h" #import "HippySRSIMDHelpers.h" typedef NS_ENUM(NSInteger, HippySROpCode) { HippySROpCodeTextFrame = 0x1, HippySROpCodeBinaryFrame = 0x2, // 3-7 reserved. HippySROpCodeConnectionClose = 0x8, HippySROpCodePing = 0x9, HippySROpCodePong = 0xA, // B-F reserved. }; typedef struct { BOOL fin; // BOOL rsv1; // BOOL rsv2; // BOOL rsv3; uint8_t opcode; BOOL masked; uint64_t payload_length; } frame_header; static NSString *const HippySRWebSocketAppendToSecKeyString = @"258EAFA5-E914-47DA-95CA-C5AB0DC85B11"; //#define HippySR_ENABLE_LOG #ifdef HippySR_ENABLE_LOG #define HippySRLog(format...) HippyLogInfo(format) #else #define HippySRLog(...) \ do { \ } while (0) #endif // This is a hack, and probably not optimal static inline int32_t validate_dispatch_data_partial_string(NSData *data) { static const int maxCodepointSize = 3; for (int i = 0; i < maxCodepointSize; i++) { NSString *str = [[NSString alloc] initWithBytesNoCopy:(char *)data.bytes length:data.length - i encoding:NSUTF8StringEncoding freeWhenDone:NO]; if (str) { return (int32_t)data.length - i; } } return -1; } @interface NSData (HippySRWebSocket) @property (nonatomic, readonly, copy) NSString *stringBySHA1ThenBase64Encoding; @end @interface NSString (HippySRWebSocket) @property (nonatomic, readonly, copy) NSString *stringBySHA1ThenBase64Encoding; @end @interface NSURL (HippySRWebSocket) // The origin isn't really applicable for a native application. // So instead, just map ws -> http and wss -> https. @property (nonatomic, readonly, copy) NSString *HippySR_origin; @end @interface _HippySRRunLoopThread : NSThread @property (nonatomic, readonly) NSRunLoop *runLoop; @end static NSString *newSHA1String(const char *bytes, size_t length) { uint8_t md[CC_SHA1_DIGEST_LENGTH]; assert(length >= 0); assert(length <= UINT32_MAX); CC_SHA1(bytes, (CC_LONG)length, md); NSData *data = [NSData dataWithBytes:md length:CC_SHA1_DIGEST_LENGTH]; return [data base64EncodedStringWithOptions:0]; } @implementation NSData (HippySRWebSocket) - (NSString *)stringBySHA1ThenBase64Encoding { return newSHA1String(self.bytes, self.length); } @end @implementation NSString (HippySRWebSocket) - (NSString *)stringBySHA1ThenBase64Encoding { return newSHA1String(self.UTF8String, self.length); } @end NSString *const HippySRWebSocketErrorDomain = @"HippySRWebSocketErrorDomain"; NSString *const HippySRHTTPResponseErrorKey = @"HTTPResponseStatusCode"; // Returns number of bytes consumed. Returning 0 means you didn't match. // Sends bytes to callback handler; typedef size_t (^stream_scanner)(NSData *collected_data); typedef void (^data_callback)(HippySRWebSocket *webSocket, NSData *data); @interface HippySRIOConsumer : NSObject @property (nonatomic, copy, readonly) stream_scanner consumer; @property (nonatomic, copy, readonly) data_callback handler; @property (nonatomic, assign) size_t bytesNeeded; @property (nonatomic, assign, readonly) BOOL readToCurrentFrame; @property (nonatomic, assign, readonly) BOOL unmaskBytes; @end // This class is not thread-safe, and is expected to always be run on the same queue. @interface HippySRIOConsumerPool : NSObject - (instancetype)initWithBufferCapacity:(NSUInteger)poolSize; - (HippySRIOConsumer *)consumerWithScanner:(stream_scanner)scanner handler:(data_callback)handler bytesNeeded:(size_t)bytesNeeded readToCurrentFrame:(BOOL)readToCurrentFrame unmaskBytes:(BOOL)unmaskBytes; - (void)returnConsumer:(HippySRIOConsumer *)consumer; @end @interface HippySRWebSocket () - (void)_writeData:(NSData *)data; - (void)_closeWithProtocolError:(NSString *)message; - (void)_failWithError:(NSError *)error; - (void)_disconnect; - (void)_readFrameNew; - (void)_readFrameContinue; - (void)_pumpScanner; - (void)_pumpWriting; - (void)_addConsumerWithScanner:(stream_scanner)consumer callback:(data_callback)callback; - (void)_addConsumerWithDataLength:(size_t)dataLength callback:(data_callback)callback readToCurrentFrame:(BOOL)readToCurrentFrame unmaskBytes:(BOOL)unmaskBytes; - (void)_addConsumerWithScanner:(stream_scanner)consumer callback:(data_callback)callback dataLength:(size_t)dataLength; - (void)_readUntilBytes:(const void *)bytes length:(size_t)length callback:(data_callback)dataHandler; - (void)_readUntilHeaderCompleteWithCallback:(data_callback)dataHandler; - (void)_sendFrameWithOpcode:(HippySROpCode)opcode data:(id)data; - (BOOL)_checkHandshake:(CFHTTPMessageRef)httpMessage; - (void)_HippySR_commonInit; - (void)_initializeStreams; - (void)_connect; @property (nonatomic, assign) HippySRReadyState readyState; @property (nonatomic, strong) NSOperationQueue *delegateOperationQueue; @property (nonatomic, strong) dispatch_queue_t delegateDispatchQueue; @end @implementation HippySRWebSocket { NSInteger _webSocketVersion; NSOperationQueue *_delegateOperationQueue; dispatch_queue_t _delegateDispatchQueue; dispatch_queue_t _workQueue; NSMutableArray *_consumers; NSInputStream *_inputStream; NSOutputStream *_outputStream; NSMutableData *_readBuffer; NSUInteger _readBufferOffset; NSMutableData *_outputBuffer; NSUInteger _outputBufferOffset; uint8_t _currentFrameOpcode; size_t _currentFrameCount; size_t _readOpCount; uint32_t _currentStringScanPosition; NSMutableData *_currentFrameData; NSString *_closeReason; NSString *_secKey; BOOL _pinnedCertFound; uint8_t _currentReadMaskKey[4]; size_t _currentReadMaskOffset; BOOL _closeWhenFinishedWriting; BOOL _failed; BOOL _secure; NSURLRequest *_urlRequest; CFHTTPMessageRef _receivedHTTPHeaders; BOOL _sentClose; BOOL _didFail; int _closeCode; BOOL _isPumping; NSMutableSet *_scheduledRunloops; // We use this to retain ourselves. HippySRWebSocket *_selfRetain; NSArray *_requestedProtocols; HippySRIOConsumerPool *_consumerPool; } static __strong NSData *CRLFCRLF; + (void)initialize { CRLFCRLF = [[NSData alloc] initWithBytes:"\r\n\r\n" length:4]; } - (instancetype)initWithURLRequest:(NSURLRequest *)request protocols:(NSArray *)protocols { HippyAssertParam(request); if ((self = [super init])) { _url = request.URL; _urlRequest = request; _requestedProtocols = [protocols copy]; [self _HippySR_commonInit]; } return self; } - (instancetype)initWithURLRequest:(NSURLRequest *)request { return [self initWithURLRequest:request protocols:nil]; } - (instancetype)initWithURL:(NSURL *)URL { return [self initWithURL:URL protocols:nil]; } - (instancetype)initWithURL:(NSURL *)URL protocols:(NSArray *)protocols { NSMutableURLRequest *request; if (URL) { // Build a mutable request so we can fill the cookie header. request = [NSMutableURLRequest requestWithURL:URL]; // We load cookies from sharedHTTPCookieStorage (shared with XHR and // fetch). To get HTTPS-only cookies for wss URLs, replace wss with https // in the URL. NSURLComponents *components = [NSURLComponents componentsWithURL:URL resolvingAgainstBaseURL:true]; if ([components.scheme isEqualToString:@"wss"]) { components.scheme = @"https"; } // Load and set the cookie header. NSArray *cookies = [[NSHTTPCookieStorage sharedHTTPCookieStorage] cookiesForURL:components.URL]; [request setAllHTTPHeaderFields:[NSHTTPCookie requestHeaderFieldsWithCookies:cookies]]; } return [self initWithURLRequest:request protocols:protocols]; } - (void)_HippySR_commonInit { NSString *scheme = _url.scheme.lowercaseString; assert( [scheme isEqualToString:@"ws"] || [scheme isEqualToString:@"http"] || [scheme isEqualToString:@"wss"] || [scheme isEqualToString:@"https"]); if ([scheme isEqualToString:@"wss"] || [scheme isEqualToString:@"https"]) { _secure = YES; } _readyState = HippySR_CONNECTING; _webSocketVersion = 13; _workQueue = dispatch_queue_create("com.tencent.hippy.SRWebSocket", DISPATCH_QUEUE_SERIAL); // Going to set a specific on the queue so we can validate we're on the work queue dispatch_queue_set_specific(_workQueue, (__bridge void *)self, (__bridge void *)_workQueue, NULL); _delegateDispatchQueue = dispatch_get_main_queue(); _readBuffer = [NSMutableData new]; _outputBuffer = [NSMutableData new]; _currentFrameData = [NSMutableData new]; _consumers = [NSMutableArray new]; _consumerPool = [HippySRIOConsumerPool new]; _scheduledRunloops = [NSMutableSet new]; [self _initializeStreams]; // default handlers } - (void)assertOnWorkQueue { assert(dispatch_get_specific((__bridge void *)self) == (__bridge void *)_workQueue); } - (void)dealloc { _inputStream.delegate = nil; _outputStream.delegate = nil; [_inputStream close]; [_outputStream close]; _workQueue = NULL; if (_receivedHTTPHeaders) { CFRelease(_receivedHTTPHeaders); _receivedHTTPHeaders = NULL; } if (_delegateDispatchQueue) { _delegateDispatchQueue = NULL; } } #ifndef NDEBUG - (void)setReadyState:(HippySRReadyState)aReadyState { [self willChangeValueForKey:@"readyState"]; assert(aReadyState > _readyState); _readyState = aReadyState; [self didChangeValueForKey:@"readyState"]; } #endif - (void)open { assert(_url); HippyAssert(_readyState == HippySR_CONNECTING, @"Cannot call -(void)open on HippySRWebSocket more than once"); _selfRetain = self; [self _connect]; } // Calls block on delegate queue - (void)_performDelegateBlock:(dispatch_block_t)block { if (_delegateOperationQueue) { [_delegateOperationQueue addOperationWithBlock:block]; } else { assert(_delegateDispatchQueue); dispatch_async(_delegateDispatchQueue, block); } } - (void)setDelegateDispatchQueue:(dispatch_queue_t)queue { _delegateDispatchQueue = queue; } - (BOOL)_checkHandshake:(CFHTTPMessageRef)httpMessage { NSString *acceptHeader = CFBridgingRelease(CFHTTPMessageCopyHeaderFieldValue(httpMessage, CFSTR("Sec-WebSocket-Accept"))); if (acceptHeader == nil) { return NO; } NSString *concattedString = [_secKey stringByAppendingString:HippySRWebSocketAppendToSecKeyString]; NSString *expectedAccept = [concattedString stringBySHA1ThenBase64Encoding]; return [acceptHeader isEqualToString:expectedAccept]; } - (void)_HTTPHeadersDidFinish { NSInteger responseCode = CFHTTPMessageGetResponseStatusCode(_receivedHTTPHeaders); if (responseCode >= 400) { HippySRLog(@"Request failed with response code %ld", responseCode); [self _failWithError:[NSError errorWithDomain:HippySRWebSocketErrorDomain code:2132 userInfo:@{ NSLocalizedDescriptionKey: [NSString stringWithFormat:@"received bad response code from server %ld", (long)responseCode], HippySRHTTPResponseErrorKey: @(responseCode) }]]; return; } if (![self _checkHandshake:_receivedHTTPHeaders]) { [self _failWithError:[NSError errorWithDomain:HippySRWebSocketErrorDomain code:2133 userInfo:@{ NSLocalizedDescriptionKey: [NSString stringWithFormat:@"Invalid Sec-WebSocket-Accept response"] }]]; return; } NSString *negotiatedProtocol = CFBridgingRelease(CFHTTPMessageCopyHeaderFieldValue(_receivedHTTPHeaders, CFSTR("Sec-WebSocket-Protocol"))); if (negotiatedProtocol) { // Make sure we requested the protocol if ([_requestedProtocols indexOfObject:negotiatedProtocol] == NSNotFound) { [self _failWithError:[NSError errorWithDomain:HippySRWebSocketErrorDomain code:2133 userInfo:@{ NSLocalizedDescriptionKey: [NSString stringWithFormat:@"Server specified Sec-WebSocket-Protocol that wasn't requested"] }]]; return; } _protocol = negotiatedProtocol; } self.readyState = HippySR_OPEN; if (!_didFail) { [self _readFrameNew]; } [self _performDelegateBlock:^{ if ([self.delegate respondsToSelector:@selector(webSocketDidOpen:)]) { [self.delegate webSocketDidOpen:self]; }; }]; } - (void)_readHTTPHeader { if (_receivedHTTPHeaders == NULL) { _receivedHTTPHeaders = CFHTTPMessageCreateEmpty(NULL, NO); } [self _readUntilHeaderCompleteWithCallback:^(HippySRWebSocket *socket, NSData *data) { CFHTTPMessageAppendBytes(self->_receivedHTTPHeaders, (const UInt8 *)data.bytes, data.length); if (CFHTTPMessageIsHeaderComplete(self->_receivedHTTPHeaders)) { HippySRLog(@"Finished reading headers %@", CFBridgingRelease(CFHTTPMessageCopyAllHeaderFields(_receivedHTTPHeaders))); [socket _HTTPHeadersDidFinish]; } else { [socket _readHTTPHeader]; } }]; } - (void)didConnect { HippySRLog(@"Connected"); CFHTTPMessageRef request = CFHTTPMessageCreateRequest(NULL, CFSTR("GET"), (__bridge CFURLRef)_url, kCFHTTPVersion1_1); // Set host first so it defaults CFHTTPMessageSetHeaderFieldValue( request, CFSTR("Host"), (__bridge CFStringRef)(_url.port ? [NSString stringWithFormat:@"%@:%@", _url.host, _url.port] : _url.host)); NSMutableData *keyBytes = [[NSMutableData alloc] initWithLength:16]; __unused int result = SecRandomCopyBytes(kSecRandomDefault, keyBytes.length, keyBytes.mutableBytes); assert(result == 0); _secKey = [keyBytes base64EncodedStringWithOptions:0]; assert([_secKey length] == 24); CFHTTPMessageSetHeaderFieldValue(request, CFSTR("Upgrade"), CFSTR("websocket")); CFHTTPMessageSetHeaderFieldValue(request, CFSTR("Connection"), CFSTR("Upgrade")); CFHTTPMessageSetHeaderFieldValue(request, CFSTR("Sec-WebSocket-Key"), (__bridge CFStringRef)_secKey); CFHTTPMessageSetHeaderFieldValue( request, CFSTR("Sec-WebSocket-Version"), (__bridge CFStringRef)[NSString stringWithFormat:@"%ld", (long)_webSocketVersion]); CFHTTPMessageSetHeaderFieldValue(request, CFSTR("Origin"), (__bridge CFStringRef)_url.HippySR_origin); if (_requestedProtocols) { CFHTTPMessageSetHeaderFieldValue( request, CFSTR("Sec-WebSocket-Protocol"), (__bridge CFStringRef)[_requestedProtocols componentsJoinedByString:@", "]); } [_urlRequest.allHTTPHeaderFields enumerateKeysAndObjectsUsingBlock:^(id key, id obj, __unused BOOL *stop) { CFHTTPMessageSetHeaderFieldValue(request, (__bridge CFStringRef)key, (__bridge CFStringRef)obj); }]; NSData *message = CFBridgingRelease(CFHTTPMessageCopySerializedMessage(request)); CFRelease(request); [self _writeData:message]; [self _readHTTPHeader]; } - (void)_initializeStreams { assert(_url.port.unsignedIntValue <= UINT32_MAX); uint32_t port = _url.port.unsignedIntValue; if (port == 0) { if (!_secure) { port = 80; } else { port = 443; } } NSString *host = _url.host; CFReadStreamRef readStream = NULL; CFWriteStreamRef writeStream = NULL; CFStreamCreatePairWithSocketToHost(NULL, (__bridge CFStringRef)host, port, &readStream, &writeStream); _outputStream = CFBridgingRelease(writeStream); _inputStream = CFBridgingRelease(readStream); if (_secure) { NSMutableDictionary *SSLOptions = [NSMutableDictionary new]; [_outputStream setProperty:(__bridge id)kCFStreamSocketSecurityLevelNegotiatedSSL forKey:(__bridge id)kCFStreamPropertySocketSecurityLevel]; // If we're using pinned certs, don't validate the certificate chain if (_urlRequest.HippySR_SSLPinnedCertificates.count) { [SSLOptions setValue:@NO forKey:(__bridge id)kCFStreamSSLValidatesCertificateChain]; } #ifdef DEBUG [SSLOptions setValue:@NO forKey:(__bridge id)kCFStreamSSLValidatesCertificateChain]; #endif [_outputStream setProperty:SSLOptions forKey:(__bridge id)kCFStreamPropertySSLSettings]; } _inputStream.delegate = self; _outputStream.delegate = self; } - (void)_connect { if (!_scheduledRunloops.count) { [self scheduleInRunLoop:[NSRunLoop HippySR_networkRunLoop] forMode:NSDefaultRunLoopMode]; } [_outputStream open]; [_inputStream open]; } - (void)scheduleInRunLoop:(NSRunLoop *)aRunLoop forMode:(NSString *)mode { [_outputStream scheduleInRunLoop:aRunLoop forMode:mode]; [_inputStream scheduleInRunLoop:aRunLoop forMode:mode]; [_scheduledRunloops addObject:@[aRunLoop, mode]]; } - (void)unscheduleFromRunLoop:(NSRunLoop *)aRunLoop forMode:(NSString *)mode { [_outputStream removeFromRunLoop:aRunLoop forMode:mode]; [_inputStream removeFromRunLoop:aRunLoop forMode:mode]; [_scheduledRunloops removeObject:@[aRunLoop, mode]]; } - (void)close { [self closeWithCode:HippySRStatusCodeNormal reason:nil]; } - (void)closeWithCode:(NSInteger)code reason:(NSString *)reason { dispatch_async(_workQueue, ^{ if (self.readyState == HippySR_CLOSING || self.readyState == HippySR_CLOSED) { return; } BOOL wasConnecting = self.readyState == HippySR_CONNECTING; self.readyState = HippySR_CLOSING; HippySRLog(@"Closing with code %ld reason %@", code, reason); if (wasConnecting) { [self _disconnect]; return; } size_t maxMsgSize = [reason maximumLengthOfBytesUsingEncoding:NSUTF8StringEncoding]; NSMutableData *mutablePayload = [[NSMutableData alloc] initWithLength:sizeof(uint16_t) + maxMsgSize]; NSData *payload = mutablePayload; ((uint16_t *)mutablePayload.mutableBytes)[0] = NSSwapBigShortToHost(code); if (reason) { NSRange remainingRange = { 0 }; NSUInteger usedLength = 0; __unused BOOL success; success = [reason getBytes:(char *)mutablePayload.mutableBytes + sizeof(uint16_t) maxLength:payload.length - sizeof(uint16_t) usedLength:&usedLength encoding:NSUTF8StringEncoding options:NSStringEncodingConversionExternalRepresentation range:NSMakeRange(0, reason.length) remainingRange:&remainingRange]; assert(success); assert(remainingRange.length == 0); if (usedLength != maxMsgSize) { payload = [payload subdataWithRange:NSMakeRange(0, usedLength + sizeof(uint16_t))]; } } [self _sendFrameWithOpcode:HippySROpCodeConnectionClose data:payload]; }); } - (void)_closeWithProtocolError:(NSString *)message { // Need to shunt this on the _callbackQueue first to see if they received any messages [self _performDelegateBlock:^{ [self closeWithCode:HippySRStatusCodeProtocolError reason:message]; dispatch_async(self->_workQueue, ^{ [self _disconnect]; }); }]; } - (void)_failWithError:(NSError *)error { dispatch_async(_workQueue, ^{ if (self.readyState != HippySR_CLOSED) { self->_failed = YES; [self _performDelegateBlock:^{ if ([self.delegate respondsToSelector:@selector(webSocket:didFailWithError:)]) { [self.delegate webSocket:self didFailWithError:error]; } }]; self.readyState = HippySR_CLOSED; self->_selfRetain = nil; HippySRLog(@"Failing with error %@", error.localizedDescription); [self _disconnect]; } }); } - (void)_writeData:(NSData *)data { [self assertOnWorkQueue]; if (_closeWhenFinishedWriting) { return; } [_outputBuffer appendData:data]; [self _pumpWriting]; } - (void)send:(id)data { HippyAssert(self.readyState != HippySR_CONNECTING, @"Invalid State: Cannot call send: until connection is open"); // TODO: maybe not copy this for performance data = [data copy]; dispatch_async(_workQueue, ^{ if ([data isKindOfClass:[NSString class]]) { [self _sendFrameWithOpcode:HippySROpCodeTextFrame data:[(NSString *)data dataUsingEncoding:NSUTF8StringEncoding]]; } else if ([data isKindOfClass:[NSData class]]) { [self _sendFrameWithOpcode:HippySROpCodeBinaryFrame data:data]; } else if (data == nil) { [self _sendFrameWithOpcode:HippySROpCodeTextFrame data:data]; } else { assert(NO); } }); } - (void)sendPing:(NSData *)data { HippyAssert(self.readyState == HippySR_OPEN, @"Invalid State: Cannot call send: until connection is open"); // TODO: maybe not copy this for performance data = [data copy] ?: [NSData data]; // It's okay for a ping to be empty dispatch_async(_workQueue, ^{ [self _sendFrameWithOpcode:HippySROpCodePing data:data]; }); } - (void)handlePing:(NSData *)pingData { // Need to pingpong this off _callbackQueue first to make sure messages happen in order [self _performDelegateBlock:^{ dispatch_async(self->_workQueue, ^{ [self _sendFrameWithOpcode:HippySROpCodePong data:pingData]; }); }]; } - (void)handlePong:(NSData *)pongData { HippySRLog(@"Received pong"); [self _performDelegateBlock:^{ if ([self.delegate respondsToSelector:@selector(webSocket:didReceivePong:)]) { [self.delegate webSocket:self didReceivePong:pongData]; } }]; } - (void)_handleMessage:(id)message { HippySRLog(@"Received message"); [self _performDelegateBlock:^{ [self.delegate webSocket:self didReceiveMessage:message]; }]; } static inline BOOL closeCodeIsValid(int closeCode) { if (closeCode < 1000) { return NO; } if (closeCode >= 1000 && closeCode <= 1011) { if (closeCode == 1004 || closeCode == 1005 || closeCode == 1006) { return NO; } return YES; } if (closeCode >= 3000 && closeCode <= 3999) { return YES; } if (closeCode >= 4000 && closeCode <= 4999) { return YES; } return NO; } // Note from RFC: // // If there is a body, the first two // bytes of the body MUST be a 2-byte unsigned integer (in network byte // order) representing a status code with value /code/ defined in // Section 7.4. Following the 2-byte integer the body MAY contain UTF-8 // encoded data with value /reason/, the interpretation of which is not // defined by this specification. - (void)handleCloseWithData:(NSData *)data { size_t dataSize = data.length; __block uint16_t closeCode = 0; HippySRLog(@"Received close frame"); if (dataSize == 1) { // TODO: handle error [self _closeWithProtocolError:@"Payload for close must be larger than 2 bytes"]; return; } else if (dataSize >= 2) { [data getBytes:&closeCode length:sizeof(closeCode)]; _closeCode = NSSwapBigShortToHost(closeCode); if (!closeCodeIsValid(_closeCode)) { [self _closeWithProtocolError:[NSString stringWithFormat:@"Cannot have close code of %d", _closeCode]]; return; } if (dataSize > 2) { _closeReason = [[NSString alloc] initWithData:[data subdataWithRange:NSMakeRange(2, dataSize - 2)] encoding:NSUTF8StringEncoding]; if (!_closeReason) { [self _closeWithProtocolError:@"Close reason MUST be valid UTF-8"]; return; } } } else { _closeCode = HippySRStatusNoStatusReceived; } [self assertOnWorkQueue]; if (self.readyState == HippySR_OPEN) { [self closeWithCode:1000 reason:nil]; } dispatch_async(_workQueue, ^{ [self _disconnect]; }); } - (void)_disconnect { [self assertOnWorkQueue]; HippySRLog(@"Trying to disconnect"); _closeWhenFinishedWriting = YES; [self _pumpWriting]; } - (void)_handleFrameWithData:(NSData *)frameData opCode:(NSInteger)opcode { // Check that the current data is valid UTF8 BOOL isControlFrame = (opcode == HippySROpCodePing || opcode == HippySROpCodePong || opcode == HippySROpCodeConnectionClose); if (!isControlFrame) { [self _readFrameNew]; } else { dispatch_async(_workQueue, ^{ [self _readFrameContinue]; }); } switch (opcode) { case HippySROpCodeTextFrame: { NSString *str = [[NSString alloc] initWithData:frameData encoding:NSUTF8StringEncoding]; if (str == nil && frameData) { [self closeWithCode:HippySRStatusCodeInvalidUTF8 reason:@"Text frames must be valid UTF-8"]; dispatch_async(_workQueue, ^{ [self _disconnect]; }); return; } [self _handleMessage:str]; break; } case HippySROpCodeBinaryFrame: [self _handleMessage:[frameData copy]]; break; case HippySROpCodeConnectionClose: [self handleCloseWithData:frameData]; break; case HippySROpCodePing: [self handlePing:frameData]; break; case HippySROpCodePong: [self handlePong:frameData]; break; default: [self _closeWithProtocolError:[NSString stringWithFormat:@"Unknown opcode %ld", (long)opcode]]; // TODO: Handle invalid opcode break; } } - (void)_handleFrameHeader:(frame_header)frame_header curData:(NSData *)curData { assert(frame_header.opcode != 0); if (self.readyState != HippySR_OPEN) { return; } BOOL isControlFrame = (frame_header.opcode == HippySROpCodePing || frame_header.opcode == HippySROpCodePong || frame_header.opcode == HippySROpCodeConnectionClose); if (isControlFrame && !frame_header.fin) { [self _closeWithProtocolError:@"Fragmented control frames not allowed"]; return; } if (isControlFrame && frame_header.payload_length >= 126) { [self _closeWithProtocolError:@"Control frames cannot have payloads larger than 126 bytes"]; return; } if (!isControlFrame) { _currentFrameOpcode = frame_header.opcode; _currentFrameCount += 1; } if (frame_header.payload_length == 0) { if (isControlFrame) { [self _handleFrameWithData:curData opCode:frame_header.opcode]; } else { if (frame_header.fin) { [self _handleFrameWithData:_currentFrameData opCode:frame_header.opcode]; } else { // TODO: add assert that opcode is not a control; [self _readFrameContinue]; } } } else { assert(frame_header.payload_length <= SIZE_T_MAX); [self _addConsumerWithDataLength:(size_t)frame_header.payload_length callback:^(HippySRWebSocket *socket, NSData *newData) { if (isControlFrame) { [socket _handleFrameWithData:newData opCode:frame_header.opcode]; } else { if (frame_header.fin) { [socket _handleFrameWithData:socket->_currentFrameData opCode:frame_header.opcode]; } else { // TODO: add assert that opcode is not a control; [socket _readFrameContinue]; } } } readToCurrentFrame:!isControlFrame unmaskBytes:frame_header.masked]; } } /* From RFC: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-------+-+-------------+-------------------------------+ |F|R|R|R| opcode|M| Payload len | Extended payload length | |I|S|S|S| (4) |A| (7) | (16/64) | |N|V|V|V| |S| | (if payload len==126/127) | | |1|2|3| |K| | | +-+-+-+-+-------+-+-------------+ - - - - - - - - - - - - - - - + | Extended payload length continued, if payload len == 127 | + - - - - - - - - - - - - - - - +-------------------------------+ | |Masking-key, if MASK set to 1 | +-------------------------------+-------------------------------+ | Masking-key (continued) | Payload Data | +-------------------------------- - - - - - - - - - - - - - - - + : Payload Data continued ... : + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + | Payload Data continued ... | +---------------------------------------------------------------+ */ static const uint8_t HippySRFinMask = 0x80; static const uint8_t HippySROpCodeMask = 0x0F; static const uint8_t HippySRRsvMask = 0x70; static const uint8_t HippySRMaskMask = 0x80; static const uint8_t HippySRPayloadLenMask = 0x7F; - (void)_readFrameContinue { assert((_currentFrameCount == 0 && _currentFrameOpcode == 0) || (_currentFrameCount > 0 && _currentFrameOpcode > 0)); [self _addConsumerWithDataLength:2 callback:^(HippySRWebSocket *socket, NSData *data) { __block frame_header header = { 0 }; const uint8_t *headerBuffer = data.bytes; assert(data.length >= 2); if (headerBuffer[0] & HippySRRsvMask) { [socket _closeWithProtocolError:@"Server used RSV bits"]; return; } uint8_t receivedOpcode = (HippySROpCodeMask & headerBuffer[0]); BOOL isControlFrame = (receivedOpcode == HippySROpCodePing || receivedOpcode == HippySROpCodePong || receivedOpcode == HippySROpCodeConnectionClose); if (!isControlFrame && receivedOpcode != 0 && socket->_currentFrameCount > 0) { [socket _closeWithProtocolError:@"all data frames after the initial data frame must have opcode 0"]; return; } if (receivedOpcode == 0 && socket->_currentFrameCount == 0) { [socket _closeWithProtocolError:@"cannot continue a message"]; return; } header.opcode = receivedOpcode == 0 ? socket->_currentFrameOpcode : receivedOpcode; header.fin = !!(HippySRFinMask & headerBuffer[0]); header.masked = !!(HippySRMaskMask & headerBuffer[1]); header.payload_length = HippySRPayloadLenMask & headerBuffer[1]; headerBuffer = NULL; if (header.masked) { [socket _closeWithProtocolError:@"Client must receive unmasked data"]; } size_t extra_bytes_needed = header.masked ? sizeof(self->_currentReadMaskKey) : 0; if (header.payload_length == 126) { extra_bytes_needed += sizeof(uint16_t); } else if (header.payload_length == 127) { extra_bytes_needed += sizeof(uint64_t); } if (extra_bytes_needed == 0) { [socket _handleFrameHeader:header curData:socket->_currentFrameData]; } else { [socket _addConsumerWithDataLength:extra_bytes_needed callback:^(HippySRWebSocket *_socket, NSData *_data) { __unused size_t mapped_size = _data.length; const void *mapped_buffer = _data.bytes; size_t offset = 0; if (header.payload_length == 126) { assert(mapped_size >= sizeof(uint16_t)); uint16_t newLen = NSSwapBigShortToHost(*(uint16_t *)(mapped_buffer)); header.payload_length = newLen; offset += sizeof(uint16_t); } else if (header.payload_length == 127) { assert(mapped_size >= sizeof(uint64_t)); header.payload_length = NSSwapBigShortToHost(*(uint64_t *)(mapped_buffer)); offset += sizeof(uint64_t); } else { assert(header.payload_length < 126 && header.payload_length >= 0); } if (header.masked) { assert(mapped_size >= sizeof(self->_currentReadMaskOffset) + offset); memcpy(_socket->_currentReadMaskKey, ((uint8_t *)mapped_buffer) + offset, sizeof(_socket->_currentReadMaskKey)); } [_socket _handleFrameHeader:header curData:_socket->_currentFrameData]; } readToCurrentFrame:NO unmaskBytes:NO]; } } readToCurrentFrame:NO unmaskBytes:NO]; } - (void)_readFrameNew { dispatch_async(_workQueue, ^{ self->_currentFrameData.length = 0; self->_currentFrameOpcode = 0; self->_currentFrameCount = 0; self->_readOpCount = 0; self->_currentStringScanPosition = 0; [self _readFrameContinue]; }); } - (void)_pumpWriting { [self assertOnWorkQueue]; NSUInteger dataLength = _outputBuffer.length; if (dataLength - _outputBufferOffset > 0 && _outputStream.hasSpaceAvailable) { NSInteger bytesWritten = [_outputStream write:_outputBuffer.bytes + _outputBufferOffset maxLength:dataLength - _outputBufferOffset]; if (bytesWritten == -1) { [self _failWithError:[NSError errorWithDomain:HippySRWebSocketErrorDomain code:2145 userInfo:@{ NSLocalizedDescriptionKey: @"Error writing to stream" }]]; return; } _outputBufferOffset += bytesWritten; if (_outputBufferOffset > 4096 && _outputBufferOffset > (_outputBuffer.length >> 1)) { _outputBuffer = [[NSMutableData alloc] initWithBytes:(char *)_outputBuffer.bytes + _outputBufferOffset length:_outputBuffer.length - _outputBufferOffset]; _outputBufferOffset = 0; } } if (_closeWhenFinishedWriting && _outputBuffer.length - _outputBufferOffset == 0 && (_inputStream.streamStatus != NSStreamStatusNotOpen && _inputStream.streamStatus != NSStreamStatusClosed) && !_sentClose) { _sentClose = YES; [_outputStream close]; [_inputStream close]; for (NSArray *runLoop in [_scheduledRunloops copy]) { [self unscheduleFromRunLoop:runLoop[0] forMode:runLoop[1]]; } if (!_failed) { [self _performDelegateBlock:^{ if ([self.delegate respondsToSelector:@selector(webSocket:didCloseWithCode:reason:wasClean:)]) { [self.delegate webSocket:self didCloseWithCode:self->_closeCode reason:self->_closeReason wasClean:YES]; } }]; } _selfRetain = nil; } } - (void)_addConsumerWithScanner:(stream_scanner)consumer callback:(data_callback)callback { [self assertOnWorkQueue]; [self _addConsumerWithScanner:consumer callback:callback dataLength:0]; } - (void)_addConsumerWithDataLength:(size_t)dataLength callback:(data_callback)callback readToCurrentFrame:(BOOL)readToCurrentFrame unmaskBytes:(BOOL)unmaskBytes { [self assertOnWorkQueue]; assert(dataLength); [_consumers addObject:[_consumerPool consumerWithScanner:nil handler:callback bytesNeeded:dataLength readToCurrentFrame:readToCurrentFrame unmaskBytes:unmaskBytes]]; [self _pumpScanner]; } - (void)_addConsumerWithScanner:(stream_scanner)consumer callback:(data_callback)callback dataLength:(size_t)dataLength { [self assertOnWorkQueue]; [_consumers addObject:[_consumerPool consumerWithScanner:consumer handler:callback bytesNeeded:dataLength readToCurrentFrame:NO unmaskBytes:NO]]; [self _pumpScanner]; } static const char CRLFCRLFBytes[] = { '\r', '\n', '\r', '\n' }; - (void)_readUntilHeaderCompleteWithCallback:(data_callback)dataHandler { [self _readUntilBytes:CRLFCRLFBytes length:sizeof(CRLFCRLFBytes) callback:dataHandler]; } - (void)_readUntilBytes:(const void *)bytes length:(size_t)length callback:(data_callback)dataHandler { // TODO: optimize so this can continue from where we last searched stream_scanner consumer = ^size_t(NSData *data) { __block size_t found_size = 0; __block size_t match_count = 0; size_t size = data.length; const unsigned char *buffer = data.bytes; for (size_t i = 0; i < size; i++) { if (((const unsigned char *)buffer)[i] == ((const unsigned char *)bytes)[match_count]) { match_count += 1; if (match_count == length) { found_size = i + 1; break; } } else { match_count = 0; } } return found_size; }; [self _addConsumerWithScanner:consumer callback:dataHandler]; } // Returns true if did work - (BOOL)_innerPumpScanner { BOOL didWork = NO; if (self.readyState >= HippySR_CLOSING) { return didWork; } if (!_consumers.count) { return didWork; } size_t curSize = _readBuffer.length - _readBufferOffset; if (!curSize) { return didWork; } HippySRIOConsumer *consumer = _consumers[0]; size_t bytesNeeded = consumer.bytesNeeded; size_t foundSize = 0; if (consumer.consumer) { NSData *tempView = [NSData dataWithBytesNoCopy:(char *)_readBuffer.bytes + _readBufferOffset length:_readBuffer.length - _readBufferOffset freeWhenDone:NO]; foundSize = consumer.consumer(tempView); } else { assert(consumer.bytesNeeded); if (curSize >= bytesNeeded) { foundSize = bytesNeeded; } else if (consumer.readToCurrentFrame) { foundSize = curSize; } } NSData *slice = nil; if (consumer.readToCurrentFrame || foundSize) { NSRange sliceRange = NSMakeRange(_readBufferOffset, foundSize); slice = [_readBuffer subdataWithRange:sliceRange]; _readBufferOffset += foundSize; if (_readBufferOffset > 4096 && _readBufferOffset > (_readBuffer.length >> 1)) { _readBuffer = [[NSMutableData alloc] initWithBytes:(char *)_readBuffer.bytes + _readBufferOffset length:_readBuffer.length - _readBufferOffset]; _readBufferOffset = 0; } if (consumer.unmaskBytes) { NSMutableData *mutableSlice = [slice mutableCopy]; NSUInteger len = mutableSlice.length; uint8_t *bytes = mutableSlice.mutableBytes; for (NSUInteger i = 0; i < len; i++) { bytes[i] = bytes[i] ^ _currentReadMaskKey[_currentReadMaskOffset % sizeof(_currentReadMaskKey)]; _currentReadMaskOffset += 1; } slice = mutableSlice; } if (consumer.readToCurrentFrame) { [_currentFrameData appendData:slice]; _readOpCount += 1; if (_currentFrameOpcode == HippySROpCodeTextFrame) { // Validate UTF8 stuff. size_t currentDataSize = _currentFrameData.length; if (_currentFrameOpcode == HippySROpCodeTextFrame && currentDataSize > 0) { // TODO: Optimize this. Don't really have to copy all the data each time size_t scanSize = currentDataSize - _currentStringScanPosition; NSData *scan_data = [_currentFrameData subdataWithRange:NSMakeRange(_currentStringScanPosition, scanSize)]; int32_t valid_utf8_size = validate_dispatch_data_partial_string(scan_data); if (valid_utf8_size == -1) { [self closeWithCode:HippySRStatusCodeInvalidUTF8 reason:@"Text frames must be valid UTF-8"]; dispatch_async(_workQueue, ^{ [self _disconnect]; }); return didWork; } else { _currentStringScanPosition += valid_utf8_size; } } } consumer.bytesNeeded -= foundSize; if (consumer.bytesNeeded == 0) { [_consumers removeObjectAtIndex:0]; consumer.handler(self, nil); [_consumerPool returnConsumer:consumer]; didWork = YES; } } else if (foundSize) { [_consumers removeObjectAtIndex:0]; consumer.handler(self, slice); [_consumerPool returnConsumer:consumer]; didWork = YES; } } return didWork; } - (void)_pumpScanner { [self assertOnWorkQueue]; if (!_isPumping) { _isPumping = YES; } else { return; } while ([self _innerPumpScanner]) { } _isPumping = NO; } //#define NOMASK static const size_t HippySRFrameHeaderOverhead = 32; - (void)_sendFrameWithOpcode:(HippySROpCode)opCode data:(id)data { [self assertOnWorkQueue]; if (!data) { return; } NSData *originData = [data isKindOfClass:[NSData class]] ? data : [(NSString *)data dataUsingEncoding:NSUTF8StringEncoding]; size_t payloadLength = originData.length; NSMutableData *frameData = [[NSMutableData alloc] initWithLength:payloadLength + HippySRFrameHeaderOverhead]; if (!frameData) { [self closeWithCode:HippySRStatusCodeMessageTooBig reason:@"Message too big"]; return; } uint8_t *frameBuffer = (uint8_t *)frameData.mutableBytes; // set fin frameBuffer[0] = HippySRFinMask | opCode; // set the mask and header frameBuffer[1] |= HippySRMaskMask; size_t frameBufferSize = 2; if (payloadLength < 126) { frameBuffer[1] |= payloadLength; } else { uint64_t declaredPayloadLength = 0; size_t declaredPayloadLengthSize = 0; if (payloadLength <= UINT16_MAX) { frameBuffer[1] |= 126; declaredPayloadLength = CFSwapInt16BigToHost((uint16_t)payloadLength); declaredPayloadLengthSize = sizeof(uint16_t); } else { frameBuffer[1] |= 127; declaredPayloadLength = CFSwapInt64BigToHost((uint64_t)payloadLength); declaredPayloadLengthSize = sizeof(uint64_t); } memcpy((frameBuffer + frameBufferSize), &declaredPayloadLength, declaredPayloadLengthSize); frameBufferSize += declaredPayloadLengthSize; } const uint8_t *unmaskedPayloadBuffer = (uint8_t *)originData.bytes; uint8_t *maskKey = frameBuffer + frameBufferSize; size_t randomBytesSize = sizeof(uint32_t); int result = SecRandomCopyBytes(kSecRandomDefault, randomBytesSize, maskKey); if (result != 0) { //TODO: (nlutsenko) Check if there was an error. } frameBufferSize += randomBytesSize; // Copy and unmask the buffer uint8_t *frameBufferPayloadPointer = frameBuffer + frameBufferSize; memcpy(frameBufferPayloadPointer, unmaskedPayloadBuffer, payloadLength); HippySRMaskBytesSIMD(frameBufferPayloadPointer, payloadLength, maskKey); frameBufferSize += payloadLength; assert(frameBufferSize <= frameData.length); frameData.length = frameBufferSize; [self _writeData:frameData]; } - (void)stream:(NSStream *)aStream handleEvent:(NSStreamEvent)eventCode { if (_secure && !_pinnedCertFound && (eventCode == NSStreamEventHasBytesAvailable || eventCode == NSStreamEventHasSpaceAvailable)) { NSArray *sslCerts = _urlRequest.HippySR_SSLPinnedCertificates; if (sslCerts) { SecTrustRef secTrust = (__bridge SecTrustRef)[aStream propertyForKey:(__bridge id)kCFStreamPropertySSLPeerTrust]; if (secTrust) { NSInteger numCerts = SecTrustGetCertificateCount(secTrust); for (NSInteger i = 0; i < numCerts && !_pinnedCertFound; i++) { SecCertificateRef cert = SecTrustGetCertificateAtIndex(secTrust, i); NSData *certData = CFBridgingRelease(SecCertificateCopyData(cert)); for (id ref in sslCerts) { SecCertificateRef trustedCert = (__bridge SecCertificateRef)ref; NSData *trustedCertData = CFBridgingRelease(SecCertificateCopyData(trustedCert)); if ([trustedCertData isEqualToData:certData]) { _pinnedCertFound = YES; break; } } } } if (!_pinnedCertFound) { dispatch_async(_workQueue, ^{ [self _failWithError:[NSError errorWithDomain:HippySRWebSocketErrorDomain code:23556 userInfo:@ { NSLocalizedDescriptionKey: [NSString stringWithFormat:@"Invalid server cert"] }]]; }); return; } } } assert(_workQueue != NULL); dispatch_async(_workQueue, ^{ switch (eventCode) { case NSStreamEventOpenCompleted: { HippySRLog(@"NSStreamEventOpenCompleted %@", aStream); if (self.readyState >= HippySR_CLOSING) { return; } assert(self->_readBuffer); if (self.readyState == HippySR_CONNECTING && aStream == self->_inputStream) { [self didConnect]; } [self _pumpWriting]; [self _pumpScanner]; break; } case NSStreamEventErrorOccurred: { HippySRLog(@"NSStreamEventErrorOccurred %@ %@", aStream, [aStream.streamError copy]); // TODO: specify error better! [self _failWithError:aStream.streamError]; self->_readBufferOffset = 0; self->_readBuffer.length = 0; break; } case NSStreamEventEndEncountered: { [self _pumpScanner]; HippySRLog(@"NSStreamEventEndEncountered %@", aStream); if (aStream.streamError) { [self _failWithError:aStream.streamError]; } else { dispatch_async(self->_workQueue, ^{ if (self.readyState != HippySR_CLOSED) { self.readyState = HippySR_CLOSED; self->_selfRetain = nil; } if (!self->_sentClose && !self->_failed) { self->_sentClose = YES; // If we get closed in this state it's probably not clean because we should be sending this when we send messages [self _performDelegateBlock:^{ if ([self.delegate respondsToSelector:@selector(webSocket:didCloseWithCode:reason:wasClean:)]) { [self.delegate webSocket:self didCloseWithCode:HippySRStatusCodeGoingAway reason:@"Stream end encountered" wasClean:NO]; } }]; } }); } break; } case NSStreamEventHasBytesAvailable: { HippySRLog(@"NSStreamEventHasBytesAvailable %@", aStream); const int bufferSize = 2048; uint8_t buffer[bufferSize]; while (self->_inputStream.hasBytesAvailable) { NSInteger bytes_read = [self->_inputStream read:buffer maxLength:bufferSize]; if (bytes_read > 0) { [self->_readBuffer appendBytes:buffer length:bytes_read]; } else if (bytes_read < 0) { [self _failWithError:self->_inputStream.streamError]; } if (bytes_read != bufferSize) { break; } }; [self _pumpScanner]; break; } case NSStreamEventHasSpaceAvailable: { HippySRLog(@"NSStreamEventHasSpaceAvailable %@", aStream); [self _pumpWriting]; break; } default: HippySRLog(@"(default) %@", aStream); break; } }); } @end @implementation HippySRIOConsumer - (void)setupWithScanner:(stream_scanner)scanner handler:(data_callback)handler bytesNeeded:(size_t)bytesNeeded readToCurrentFrame:(BOOL)readToCurrentFrame unmaskBytes:(BOOL)unmaskBytes { _consumer = [scanner copy]; _handler = [handler copy]; _bytesNeeded = bytesNeeded; _readToCurrentFrame = readToCurrentFrame; _unmaskBytes = unmaskBytes; assert(_consumer || _bytesNeeded); } @end @implementation HippySRIOConsumerPool { NSUInteger _poolSize; NSMutableArray *_bufferedConsumers; } - (instancetype)initWithBufferCapacity:(NSUInteger)poolSize { if ((self = [super init])) { _poolSize = poolSize; _bufferedConsumers = [[NSMutableArray alloc] initWithCapacity:poolSize]; } return self; } - (instancetype)init { return [self initWithBufferCapacity:8]; } - (HippySRIOConsumer *)consumerWithScanner:(stream_scanner)scanner handler:(data_callback)handler bytesNeeded:(size_t)bytesNeeded readToCurrentFrame:(BOOL)readToCurrentFrame unmaskBytes:(BOOL)unmaskBytes { HippySRIOConsumer *consumer = nil; if (_bufferedConsumers.count) { consumer = _bufferedConsumers.lastObject; [_bufferedConsumers removeLastObject]; } else { consumer = [HippySRIOConsumer new]; } [consumer setupWithScanner:scanner handler:handler bytesNeeded:bytesNeeded readToCurrentFrame:readToCurrentFrame unmaskBytes:unmaskBytes]; return consumer; } - (void)returnConsumer:(HippySRIOConsumer *)consumer { if (_bufferedConsumers.count < _poolSize) { [_bufferedConsumers addObject:consumer]; } } @end @implementation NSURLRequest (CertificateAdditions) - (NSArray *)HippySR_SSLPinnedCertificates { return [NSURLProtocol propertyForKey:@"HippySR_SSLPinnedCertificates" inRequest:self]; } @end @implementation NSMutableURLRequest (CertificateAdditions) - (NSArray *)HippySR_SSLPinnedCertificates { return [NSURLProtocol propertyForKey:@"HippySR_SSLPinnedCertificates" inRequest:self]; } - (void)setHippySR_SSLPinnedCertificates:(NSArray *)HippySR_SSLPinnedCertificates { [NSURLProtocol setProperty:HippySR_SSLPinnedCertificates forKey:@"HippySR_SSLPinnedCertificates" inRequest:self]; } @end @implementation NSURL (HippySRWebSocket) - (NSString *)HippySR_origin { NSString *scheme = self.scheme.lowercaseString; if ([scheme isEqualToString:@"wss"]) { scheme = @"https"; } else if ([scheme isEqualToString:@"ws"]) { scheme = @"http"; } int defaultPort = ([scheme isEqualToString:@"https"] ? 443 : [scheme isEqualToString:@"http"] ? 80 : -1); int port = self.port.intValue; if (port > 0 && port != defaultPort) { return [NSString stringWithFormat:@"%@://%@:%d", scheme, self.host, port]; } else { return [NSString stringWithFormat:@"%@://%@", scheme, self.host]; } } @end static _HippySRRunLoopThread *networkThread = nil; static NSRunLoop *networkRunLoop = nil; @implementation NSRunLoop (HippySRWebSocket) + (NSRunLoop *)HippySR_networkRunLoop { static dispatch_once_t onceToken; dispatch_once(&onceToken, ^{ networkThread = [_HippySRRunLoopThread new]; networkThread.name = @"com.squareup.SocketRocket.NetworkThread"; [networkThread start]; networkRunLoop = networkThread.runLoop; }); return networkRunLoop; } @end @implementation _HippySRRunLoopThread { dispatch_group_t _waitGroup; } @synthesize runLoop = _runLoop; - (instancetype)init { if ((self = [super init])) { _waitGroup = dispatch_group_create(); dispatch_group_enter(_waitGroup); } return self; } - (void)main { @autoreleasepool { _runLoop = [NSRunLoop currentRunLoop]; dispatch_group_leave(_waitGroup); NSTimer *timer = [[NSTimer alloc] initWithFireDate:[NSDate distantFuture] interval:0.0 target:self selector:@selector(step) userInfo:nil repeats:NO]; [_runLoop addTimer:timer forMode:NSDefaultRunLoopMode]; while ([_runLoop runMode:NSDefaultRunLoopMode beforeDate:[NSDate distantFuture]]) { } assert(NO); } } - (void)step { // Does nothing } - (NSRunLoop *)runLoop { dispatch_group_wait(_waitGroup, DISPATCH_TIME_FOREVER); return _runLoop; } @end