Experimental Physics and
Industrial Control System

Dirk Zimoch <[email protected]> · Mon, 15 Oct 2007 10:04:02 +0200

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

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System