[syslog-ng] Redirect syslog-ng to ttyS0

[Balazs Scheidler]

On Wed, 2007-11-28 at 14:46 +0100, Vidar Tyldum Hansen wrote:
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> 
> Jumping in on this thread!
> 
> > On Sun, 2007-11-18 at 19:39 +0100, Kjell Danielsen wrote:
> >> Here is a new trace. I start the trace before I logged in on ttyS0.
> >> After I logged in the syslog output to ttyS0 stops, and I have to
> >> restart the server to get the syslog output on ttyS0.
> >> 
> >> Kjell
> > 
> > the reason syslog-ng stops, because it receives a POLLERR/POLLHUP event
> > in this case:
> > 
> > poll([{fd=13, events=0, revents=POLLERR|POLLHUP
> > 
> > Hm... did syslog-ng report any kind of error in this case? I'm expecting
> > an 
> > 
> > 
> >       msg_error("EOF occurred while idle",
> >                 evt_tag_int("fd", self->fd->fd),
> >                 NULL);
> > 
> > or, a
> > 
> >         msg_error("I/O error occurred while writing",
> >                   evt_tag_int("fd", fd->fd),
> >                   evt_tag_errno(EVT_TAG_OSERROR, errno),
> >                   NULL);
> > 
> > message. I can't see anything like this in the stace file, but maybe you
> > are not reading the internal() log source?
> 
> I am a distant colleague of Kjell and put together a labtest for this
> case. I can confirm the behaviour and the strace ending with
> POLLERR/POLLHUP, and no errors given from syslog-ng.
> 
> I see that syslog-ng changes permissions on /dev/ttyS= and when you log
> in on the console port 'login' or 'agetty' changes the permissions again
> causing syslog-ng to stop.

I think this is not a permission problem. syslog-ng opens the device
once, and then it is kept opened. Permissions checking is usually
applied at open time and not any later.

-- 
Bazsi