Re: Apparent "permissions" issue with /dev/cuau0?

On Tue, Oct 28, 2008 at 10:09:17PM -0700, David Wolfskill wrote:
> This seems a bit weird to me.  I'll explain the context, then the
> perceived issue.
> 
> I maintain a port (astro/gpsman) which can make use of a serial port to
> communicate with a GPS.
> 
> The author of the program let me know earlier today that he had made a
> tarball of GPSman-6/4 available.  Accordingly, I started updating the
> port to use the new version.
> 
> While I was doing that, I noticed that there's a stanza in the port's
> Makefile:
> 
> .if ${OSVERSION} < 600000
> GPSMAN_DEFAULT_PORT?=   /dev/cuaa0
> .else
> GPSMAN_DEFAULT_PORT?=   /dev/cuad0
> .endif
> 
> and I recalled that the MPSAFE TTY layer was recently committed to HEAD,
> and that the serial device names changed accordingly.  Thus, while it
> isn't actually essential (as the user can change the device name fairlly
> readily), I thought it would be reasonable to adjust that stanza so that
> folks installing GPSman on a recent CURRENT system would at least have a
> default value that matched something on their system.
> 
> Accordingly, I changed my working copy to read:
> 
> .if ${OSVERSION} < 600000
> GPSMAN_DEFAULT_PORT?=   /dev/cuaa0
> .elif ${OSVERSION} < 800045
> GPSMAN_DEFAULT_PORT?=   /dev/cuad0
> .else
> GPSMAN_DEFAULT_PORT?=   /dev/cuau0
> .endif
> 
> I then rebooted my laptop from the CURRENT slice and tried installing
> the (updated) port.
> 
> The install was clean (as expected).  I found that I needed to move my
> old ~/.gpsman directory aside; on invocation, gpsman offered to create
> ~/.gpsman-dir (where it stashes various preferences).  I was mildly
> pleased to see that the default for the serial port showed up as
> /dev/cuau0 (as desired).
> 
> I turned on my GPS, plugged it in, tried getting gpsman to talk to it,
> and got a complaint: GPSman said that I didn't have permission (I
> *think* that was its whine, anyway).  I looked; the device was:
> 
> crw-rw----  1 uucp  dialer    0,  51 Oct 28 20:23 /dev/cuau0
> 
> and output of id(1) verified that I was in group "dialer" (specifically
> so I could do this type of thing), as expected.
> 
> 
> I then de-installed gpsman, rebooted the laptop to RELENG_6 (also built
> this morning), reinstalled GPSman, tried the "tallk tothe GPS"
> experiment again, and it worked just as it always had before -- no
> problems (using the "Garmin" protocol, if that matters).
> 
> So: the hardware works.  The physical connection should be OK.  It seems
> to me that either there's Something Weird going on with access to
> things in a file namespace in CURRENT (which isn't all that likely, as
> it would probably have an adverrse effect on tracking CURRENT daily --
> and others would likely have been ... mentioning ... it) or GPSman is
> trying to do something to the serial port in a way that is no longer
> supported in CURRENT.
> 
> Now, GPSman is a Tcl/Tk application.  And as I'm not really sufficiently
> ambitious as to keep a separate set of installed ports ofr each of
> RELENG_6, RELENG_7, and HEAD, I set things up so that /usr/local is
> mounted from the same place regardless of which slice I boot from.  I
> then maintain the ports while running RELENG_6 -- and on the other
> slices, I have the misc/compat6x port installed.
> 
> While there are a few "gotchas" occasionally (RELENG_6 firefox isn't
> happy with CURRENT's threading model, though I could probably address
> that via /etc/libmap.conf), the vast mojority of stuff I use Just Works.
> 
> FWIW, the version of the misc/compat6x port installed is
> compat6x-i386-6.4.604000.200810.
> 
> I'm disinclined to believe that this is an issue with the 6.4 release of
> GPSman; as ssuch, I expect to send out the PR to update the port
> shortly.  But it would be nicer if the software could be used under
> FreeBSD CURRENT.  :-}
> 
> I suppose I could try using ktrace(1) to get a better idea what's going
> on.  Any other (better?) ideas?

Maybe the problem lies with tcl. We had to patch it before to handle
our serial ports (that was also for GPSman):

http://lists.freebsd.org/pipermail/freebsd-ports/2004-June/013797.html

John
-- 
John Hay -- John.Hay_at_meraka.csir.co.za / jhay_at_FreeBSD.org