Re: softioc crashes CAS (gateway) when using port number in EPICS_CA_ADDR_LIST

[Dirk Zimoch <dirk.zimoch@psi.ch>]

Hi Emmanuel

That works indeed!

When EPICS_CAS_BEACON_ADDR_LIST is set to a proper value (the broadcast address) 
before the ioc is started, the ioc does not crash the gateway any more.

Jeff, can you please have a look at the CAS? It should not be that easy to crash 
a server with unexpected or malformatted requests. A server should never blindly 
trust anything coming over the network.

Best regards,
Dirk


Emmanuel Mayssat wrote:
> The first thing I would try is to set EPICS_CAS_BEACON_ADDR_LIST...
> There was just a thread about this last week ;-)
>
> http://www.aps.anl.gov/epics/tech-talk/2007/msg01150.php
>
> If you use ports in EPICS_CA_ADDR_LIST (client search request), you will
> need to set EPICS_CAS_BEACON_ADDR_LIST (server beacon) manually.
>
> I think the problem you are experimenting is that the beacons are sent
> to the same port where search requests only are expected.
> EPICS_CAS_BEACON_ADDR_LIST default to EPICS_CA_ADDR_LIST if not set.
> Check the server configuration (EPICS_CAS_* envvars) in the channel
> access reference manual for more info.
>
> Let us know if it worked!
>
> --
> Emmanuel
>
>
>
>
> On Fri, 2007-10-12 at 14:19 +0200, Dirk Zimoch wrote:
> > Hi Jeff and others,
> >
> > I see strange crashes of the CA gateway which probably originate in the CAS code.
> >
> > If I use an explicit port in EPICS_CA_ADDR_LIST like this
> >
> > EPICS_CA_ADDR_LIST="gateway:5066"
> >
> > and then start a softioc running a record with an INP link to a record behind 
> > the gateway (running on that port), the gateway starts printing errors and 
> > refuses to handle any more requests. It has to be restarted.
> >
> > The gateway prints:
> >
> > CAS: CAS Request: ? on pc3853.psi.ch:38210: cmd=13 cid=0 typ=11 cnt=5064 psz=0 
> > avail=81818260
> >
> > Oct 12 14:01:36 !!! Errlog message received (message is above)
> > bad request code=13 in DG
> >
> > Oct 12 14:01:36 !!! Errlog message received (message is above)
> > filename="../../../../src/cas/generic/st/casDGIntfOS.cc" line number=498
> > protocol from client was invalid unexpected problem with UDP input from 
> > "pc3853.psi.ch:38210"
> >
> > Oct 12 14:01:36 !!! Errlog message received (message is above)
> > CAS: CAS Request: ? on pc3853.psi.ch:38210: cmd=13 cid=0 typ=11 cnt=5064 psz=0 
> > avail=81818260
> >
> > Oct 12 14:01:36 !!! Errlog message received (message is above)
> > bad request code=13 in DG
> >
> > Oct 12 14:01:36 !!! Errlog message received (message is above)
> > filename="../../../../src/cas/generic/st/casDGIntfOS.cc" line number=498
> > protocol from client was invalid unexpected problem with UDP input from 
> > "pc3853.psi.ch:38210"
> >
> > Oct 12 14:01:36 !!! Errlog message received (message is above)
> > ....
> >
> > However, a simple caget works without problems, at least before the softioc 
> > crashes the gateway.
> >
> >
> > I tried 3.14.8 and 3.14.9 on the ioc side. The gateway runs with some pre-3.13.9 
> > CVS snapshot. But I also tried it with the 3.14.9 libraries.
> >
> > BTW: I could not recompile the gateway with 3.14.9, because the function 
> > epicsNTOH16 does not exist any more. I had to trick the 3.14.9 libraries into 
> > the gateway's library search path.
> >
> > Please, don't remove API functions when changing Channel Access!
> >
> > Any idea?
> > Dirk

--
Dr. Dirk Zimoch
Paul Scherrer Institut, WBGB/006
5232 Villigen PSI, Switzerland
Phone +41 56 310 5182