Experimental Physics and
Industrial Control System

Michael Davidsaver via Tech-talk <tech-talk at aps.anl.gov> · Mon, 13 Jun 2022 07:26:27 -0700

On 6/13/22 06:26, Simon Rose via Tech-talk wrote:

Hi all -

Is it possible to set up an access security file to allow only CA/PVA requests from the same host as the IOC? One option of course is to use asSetSubstitutions and some variable, but it seems like there should be a more intrinsic way of doing this.

I have attempted using the name “localhost”, asCheckClientIP set to 1, even using 127.0.0.1 as a member of the host access group, but none of these seemed to work.

My two main questions:

  * Is there a better or more canonical way of doing this?
  * Perhaps more importantly--particularly if we have to use environment variables and substitutions--is there some danger or pitfall about this that we should be careful about?

CA does not automatically use the loopback interface.
There is actually no portable way to do so in the
presence of multiple IOCS.  Linux is the only OS which
(implicitly) gives the loopback interface a broadcast
address.  eg.

export EPICS_CA_ADDR_LIST=127.255.255.255

Cheers,

Simon

______________________

*Simon Rose*

Software Engineer

Control System Software and Services

*European Spallation Source ERIC*

P.O. Box 176, SE-221 00 Lund, Sweden

Visiting address: Partikelgatan 2, 224 84 Lund

Mobile: +46 72 179 23 07

E-mail: simon.rose at ess.eu <mailto:simon.rose at ess.eu>__

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Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System