On Sun, Dec 18, 2022 at 02:00:24PM +0100, Theo Buehler wrote:
> This is the remaining bit of mpf's recent netcat diff. The commit log
> shows that it was bumped to 64k in the past, but that was promptly
> reverted due to concerns of buffer bloat caused by atomicio blocking
> traffic in the other direction.

Thanks for taking care of this.
I should've done some research myself before suggesting this.

For reference:

revision 1.121
date: 2014/06/10 16:35:42;  author: tedu;  state: Exp;  lines: +2 -2;
stick with 16k buffers for a little while to avoid bufferbloat.
atomicio writing out 64k in one direction will cause traffic in the
other direction to stall until it's complete. discussion with deraadt
----------------------------
revision 1.120
date: 2014/06/10 16:23:07;  author: tedu;  state: Exp;  lines: +3 -3;
increase buffer size to 64k, and actually use it. ok deraadt
from John-Mark Gurney

> I don't know if things are different enough 8 years later that this can
> be reconsidered. Not my area, just throwing it out there so it doesn't
> get lost.

I can only assume that the concern was about talking to a server
that would block while trying to send a response after only reading a part of
the data.
I can't think of a real world scenario where this is a problem right now.

But since my use case (sending a huge UDP packet) also depends on bumping
the socket buffer size with -O, we could also make the BUFSIZE conditional on
the provided socket buffer size, or give this a new option.


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