Any other thought?
I did not open this topic because I want my program to work, but because the part of the server which processes the RCON-data might be seriously flawed.

So the question is, does the implementation of Send used implicitly set the PUSH flag with every call?
Most implementations set the PUSH flag on each segment after coalescing data supplied by send(). However, this flag is not intended for marking the end of records, as stated within the RFC and ...

I printed the data in hex before send()ing them.
The data is definitely correct and the bug can always be reproduced by changing the buffer's size of my streambuf-object, in which the bytes are stored before send()ing them, to something very small. I'm pretty sure it is a bug in Factorio.
In case ...

No, there are no additional characters.

Well, that's what I said.

The program sends valid RCON packets over the TCP stream.

So we agree that the server has to read from the TCP stream until it can assemble a valid RCON-packet?

<ABCD> and <EFGH> are effectively different streams and it doesn't matter what order they're discharged from the TCP layer to the application layer.
Your < and > don't make sense as TCP does not operate with packets (See above link to RFC). ABCD will always be sent and received before EFGH.


if ...

TCP is not message/packet/record oriented. Data can be written at one end into the stream and read from another, like pipes. See https://tools.ietf.org/html/rfc1180#page-24.

JohnyDL wrote: It might even send the <ABCD> and <EFGH> up to the application layer in a different order

That's not correct.

That's not how send works. You are sending 9 2-byte packets
TCP is stream oriented. https://linux.die.net/man/7/tcp
TCP does not preserve record boundaries.

Multiple calls to send() may be split or merged. https://stackoverflow.com/questions/17446491/tcp-stream-vs-udp-message

There is no ...

Okay, let's explicate :)

I am programming with C++ using the WinSock API on Windows or POSIX sockets on Linux for communication over TCP. To use a convenient stream-interface, I decided to create a strembuffer which can be written to or read from. The streambuffer manages to, well, buffer outgoing ...

This is the logging output when connecting and sending the RCON authentication-packet in pieces of two bytes at maximum:

52.586 Info RemoteCommandProcessor.cpp:230: New RCON connection from <IPv4-Address>:49055
52.587 Error RemoteCommandProcessor.cpp:322: Couldn't parse RCON data: Couldn't read ...

isn't this a bug not an idea/suggestion?
My bad, I somehow overlooked the bug-subforum.

you might want those log files available to the devs too
The log file merely contains "Couldn't parse RCON data: Couldn't read from input file. File could be corrupted."
Edit: and something along "client ...

Hey developers :)

I was programming some RCON client to connect to a factorio server's remote console.
The program didn't write RCON-packets at one go but rather piecewise to the TCP buffer. Subsequently the server writes something along 'Couldn't parse RCON data: Couldn't read from input file ...