outstanding telnetd bug fix, and two new features

[Denys Vlasenko]

On Monday 10 November 2008 18:42, Cathey, Jim wrote:
> This is a diff -u of the two versions of telnetd, I
> hope it is more useful.

Patch deletes this comment:

-   FIXME - if we mean to send 0xFF to the terminal then it will be escaped,
-   what is the escape character?  We aren't handling that situation here.

without ever explaining why, or including
a fix. Do we handle sending of 0xff, or not?
If not, why do you delete the comment?

> It still contains the non-IPV6 
> version of the "login -h" feature code,

This part is not accepted.

> To recap: telnetd fails to properly handle two-byte IAC
> sequences, in particular IAC-IAC, which is how a literal
> 0xFF is to be passed, which is an emacs M-DEL operation
> (delete-backward-word), and IAC-NOP, which can be used as
> a session keepalive by things such as putty.

Applied, thanks.

> The bracing 
> of the patched result stinks, the 'owner' of this code
> should feel free to improve it.  (We are operating in
> minimal differences mode, which is fairly appropriate
> for our situation.)

I do not understand why this mode prevents you
from not breaking code style. But anyway,
I fixed discrepancies in style while applying
parts of the patch.

> The other feature is to enable SO_KEEPALIVE, and add the
> telnetd standard -n option flag to turn it back off if desired.
> We were having our embedded system choke up with dead sessions,
> SO_KEEPALIVE cleans them out after a time.

Applied, thanks. I do not think we need the option
to turn it off, and it's smaller that way.
--
vda