Experimental Physics and
Industrial Control System

Andrew Johnson <[email protected]> · Mon, 29 Jun 2015 10:55:43 -0500

Hi Matej,

On 06/29/2015 04:55 AM, Matej Sekoranja wrote:
> Hi Andrew,
> 
> I started looking into this.
> … and I’ve found out that the API is already there:
> 
> 
> class epicsShareClass casChannel {
> public:
>     casChannel ( const casCtx & ctx );
>     virtual ~casChannel ();
> 
>     //
>     // Called when the user name and the host name are changed
>     // for a live connection.
>     //
>     virtual void setOwner ( const char * const pUserName,
>         const char * const pHostName );
> 
> The casChannel::setOwner method.
> I think this is what you wanted, right?
> (It just needs to be called when username is changed.)

That looks like the right method. Most existing CAS applications
probably don't implement it though; this is from the PV Gateway's
gateVc.cc file:

> #ifdef SUPPORT_OWNER_CHANGE
> // Virtual function from casChannel, not called from Gateway.  It is a
> // security hole to support this, and it is no longer implemented in
> // base.
> void gateChan::setOwner(const char* const u, const char* const h)
> {
> 	asclient->changeInfo(u,h);
> }
> #endif

The SUPPORT_OWNER_CHANGE macro is not defined in the gateway build, and
that method is similarly #ifdef'd out in the related header file. The
routine it calls is defined inline in gateAs.h:

> #ifdef SUPPORT_OWNER_CHANGE
>     // Used in virtual function setOwner from casChannel, not called
>     // from Gateway.  It is a security hole to support this, and it is
>     // no longer implemented in base.
> 	long changeInfo(const char* user, const char* host)
> 	  { return asChangeClient(asclientpvt,asentry->level,(char*)user,(char*)host);}
> #endif

Re-enabling this functionality in the gateway will obviously need
careful testing, but I guess the RBAC implementation will be making more
changes to the gateway anyhow.

- Andrew

-- 
Light thinks it travels faster than anything but it is wrong.
No matter how fast light travels, it finds the darkness has
always got there first, and is waiting for it.
    -- Terry Pratchett, Reaper Man

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System