基于TCP的客户端通信在iOS 11中不起作用？

Question

我有一个IoT应用程序，它使用套接字编程与设备通信。在iOS 11发布之前，一切都很好。它在iOS 11和更高版本中不通信，但在早期版本(最多10)中工作。这是密码。

建立套接字连接

(void)setUpSocketConnection {
    @try {
        CFStreamCreatePairWithSocketToHost(kCFAllocatorDefault, (__bridge CFStringRef) VeranoHost,VeranoPort , &readStream, &writeStream);
        [self open];
    }
    @catch (NSException *exception) {
        NSLog(@"Open Exception:%@", exception.reason);
    }   
}

开放流

(void)open {
    //NSLog(@"Opening streams.");
    _outputStream = (__bridge  NSOutputStream *)writeStream;
    _inputStream = (__bridge  NSInputStream *)readStream;
    [_outputStream setDelegate:self];
    [_inputStream setDelegate:self];

    dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH,0);
    dispatch_async(queue, ^ {
            [_outputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
            [_inputStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
            [[NSRunLoop currentRunLoop] run];
    });

    [_outputStream open];
    [_inputStream open];

    //[self disableNaglesAlgorithmForStream:_inputStream];
   // NSLog(@"Connected");
//    self.timeOutTimer = [NSTimer scheduledTimerWithTimeInterval:10.0
//                                                         target:self
//                                                       selector:@selector(timerTimeOutAction:)
//                                                       userInfo:nil
//                                                        repeats:NO];
}

写入输出流

(void)writeData:(NSString *)message forSocketType:(SOCKETTTYPE)socketType {
    self.socketType = socketType;
    NSData *data = [[NSData alloc] initWithData:[message dataUsingEncoding:NSASCIIStringEncoding]];
    [_outputStream write:[data bytes] maxLength:[data length]];
    [_outputStream close];

}

事件处理程序

(void)stream:(NSStream *)theStream handleEvent:(NSStreamEvent)streamEvent {
   // NSLog(@"stream event %lu", (unsigned long)streamEvent);
    switch (streamEvent) {
        case NSStreamEventOpenCompleted:{

           // NSLog(@"NSStreamEventOpenCompleted :::: Stream opened and connected");
        }
            break;
        case NSStreamEventHasBytesAvailable:
            // NSLog(@"NSStreamEventHasBytesAvailable :::: Stream opened and connected");
            if (theStream == _inputStream) {
                uint8_t buffer[1024];
                NSInteger len;

                while ([_inputStream hasBytesAvailable])
                {
                    len = [_inputStream read:buffer maxLength:sizeof(buffer)];
                    if (len > 0)
                    {
                        NSString *output = [[NSString alloc] initWithBytes:buffer length:len encoding:NSASCIIStringEncoding];

                        if (nil != output)
                        {
                            NSLog(@"server said: %@", output);
                            [self messageReceived:output];
                        }
                    }
                }
            }
            break;
        case NSStreamEventHasSpaceAvailable:
           // NSLog(@"NSStreamEventHasSpaceAvailable :::: Stream has space available now");
            break;

        case NSStreamEventErrorOccurred:{
           NSError *theError = [theStream streamError];
            NSLog(@"Error Description:%@",theError.localizedDescription);
            [self close];
            if(self.delegate &&[self.delegate respondsToSelector:@selector(socketHandlerItem:failureWithError:forSocketType:)]){
                [self.delegate socketHandlerItem:self failureWithError:[theStream streamError] forSocketType:self.socketType];
            }
             //NSLog(@"NSStreamEventErrorOccurred :::: %@",[theStream streamError].localizedDescription);
        }
            break;

        case NSStreamEventEndEncountered:
            [theStream close];
            [theStream removeFromRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
            if(self.delegate &&[self.delegate respondsToSelector:@selector(socketHandlerItem:eventStopedWithstatus:forSocketType:)]){
                [self.delegate socketHandlerItem:self eventStopedWithstatus:YES forSocketType:self.socketType];
            }
           // NSLog(@"NSStreamEventEndEncountered :::: close stream Disconnected");
            break;
        default:
           // NSLog(@"Unknown event");
            break;
    }
}

因此，当连接到套接字时，它在事件处理程序和日志- The operation couldn’t be completed. No route to host中输入到The operation couldn’t be completed. No route to host。

任何帮助都将不胜感激。

更新2017年12月19日

• 获得一个可达性包装器，它允许发现主机地址，并且我可以确认它返回NetworkStatus ReachableViaWiFi。
• 套接字通信工作良好，我尝试通过创建一个示例服务器套接字，能够发送和接收数据。

更新2017年12月20日(1)

IoT设备详细信息- USR-WIFI232-S低功耗WiFi模块 用户手册这里

更新2017年12月20日(2)

Eurekaa，但解决方案不能实时应用。在iOS 11中设置与IoT模块的主机地址相对应的最接近的静态IP地址范围时，通信工作良好。但它不适用于动态分配的IP地址。

Answer 1

如果it应用程序传输安全(ATS)，请参见：https://www.nowsecure.com/blog/2017/08/31/security-analysts-guide-nsapptransportsecurity-nsallowsarbitraryloads-app-transport-security-ats-exceptions/

对于iOS 11 ATS更新，预期某些ATS更新是其中的一部分：

• TLSv1.3将获得初步支持
• 3 3DES将从批准的密码列表中删除。
• 用SHA1签署的证书将不再被接受
• 用RSA密钥签名的证书必须具有2048位密钥长度或更大的长度。

您在应用程序中使用的PLIST和应享权利？

<key>NSAppTransportSecurity</key>
<dict>
    <key>NSAllowsArbitraryLoads</key>
    <true/>
    <key>NSExceptionDomains</key>
    <dict>

        <key>creativecommons.org</key>
        <dict>
            <key>NSIncludesSubdomains</key>
            <true/>
            <key>NSTemporaryExceptionAllowsInsecureHTTPLoads</key>
            <true/>
            <key>NSThirdPartyExceptionRequiresForwardSecrecy</key>
            <false/>
        </dict>

        <key>localhost</key>
        <dict>
            <key>NSIncludesSubdomains</key>
            <true/>
            <key>NSTemporaryExceptionAllowsInsecureHTTPLoads</key>
            <true/>
        </dict>

    </dict>
</dict>

另外还有一个选项，如果您想禁用ATS，可以使用以下选项：

<key>NSAppTransportSecurity</key>  
 <dict>  
      <key>NSAllowsArbitraryLoads</key><true/>  
 </dict>

但这是不推荐的！