Re: Buffered reading in LuaSocket..

[Diego Nehab <diego@...>]

Hi,

> > If you really need to limit the amount of input
>
> I can't write a safe (DoS-resistant) line-oriented server
> without it, esp.  for SMTP, not least because there are
> still SMTP clients which send large emails as one huge
> line of text. I want to be able to detect that the amount
> of SMTP data has exceeded some user-defined maximum _as it
> exceeds_ that maximum, rather than (possily long) after
> having already received (possibly much) more than the
> maximum.

With a timeout of zero, you can't read more than what fits
in the LuaSocket input buffer. Should be something like 4k.

> Thanks. Is it better to use select() than to use
> receive(1) with a timeout followed by receive(bytesleft)
> without one? Errr, yes. I think it is. Much clearer,
> anyway.

Yes. Much, better. :) Better yet would be to use something
similar to copas or dispatch.lua. Shouldn't be impossible to
implement the limit of input size on top of that. Though to
be honest I don't have a good idea of how hard it would be.

Regards,
Diego