Re: [BProc] BProc & /dev/tty - anything to watch out?

[Erik A. H. <er...@he...>]

On Tue, May 14, 2002 at 05:30:22PM +0200, ha...@no... wrote:
> Dear BProc users and gurus,
> 
> I am trying to setup occasional master->slave OpenSSH access (just for
> the convenience of environment, pty etc. during service work on slave
> node).
> 
> It works but it cannot use controlling tty. Server process complains:
> 
>  n1 sshd[19675]: error: ioctl(TIOCSCTTY): Operation not permitted 
>  n1 sshd[19675]: error: open /dev/tty failed - could not set controlling tty: No such device or address 
> 
> and client process complains:
> 
>  bash: initialize_job_control: setpgid: Operation not permitted
> 
> Then it works OK, just job control is missing. Server process is able
> to use /dev/ptmx to allocate /dev/pts/0, it opens /dev/tty but then it
> is unable to use it. This seemes strange to me.
> 
> At this moment I am not sure whether I should continue looking for
> missing files, kernel modules etc. on slave node (usual game when you
> insist on running some daemon :-) or delve into kernel sources and
> look for strange interactions of BProc and controlling tty.
> 
> So, my only question is: Is it likely that controlling terminal things
> are a bit broken in BProc patched kernel?

I think the odds of some of the tty stuff being busted are very good.
The TTY code is another chunk of kernel code which deals in process
groups that I haven't modified for BProc.

The setpgid call *should* work as usual but it's possible that it's
getting screwed up by earlier errors or it's just broken.  The process
group rules are pretty arcane and I don't know exactly how they're
supposed to work.

> Just give me some opinions to let me search in more likely
> directions...

Personally, I'd hunt down the TTY issue before worrying about the
process group thing.  There's almost certainly some brokeness in
there.

- Erik
-- 
Erik Arjan Hendriks          Printed On 100 Percent Recycled Electrons
er...@he...                   Contents may settle during shipment