QTcpSocket write data with packet loss - Idiot proof sample does not work!

[wysota]

If I choose SOCKS5 (with modification of my client), I got the content I sent, but in console your program loops with a message "QNativeSocketEngine::write() was not called in QAbstractSocket::ConnectedState" and put CPU load to 100%.

It might suggest one of the ends disconnects before all the data is written.

Otherwise, NetworqDebugger connect to my server side and send wrong data, eg. wrong packet size and then only 1 data byte.

The proxy doesn't modify your data in any way. If it sends incorrect data, it means it has received incorrect data.

I thought that I'm already doing.

No. You are sending a blob containing two bytes of serialized integer followed by serialized byte array with data. You're not sending any chunks and you're not encoding the data size properly. You're totally ignoring the fact that size may not fit into 16 bits but you're then serializing all of the data that can be of arbitrary size (e.g. 16GB). I'm assuming you're doing the same thing on the other end -- reading two bytes, interpreting it as blob size and then waiting in a loop for this amount of data to come in. At best it will put your peers out of sync, at worst it will DOS your receiver (if no data ever comes in) and possibly your sender (as you may run out of RAM trying to send a very large chunk of data that is much larger than 64kB).