[openib-general] Re: User MAD registration with RMPP

[Hal Rosenstock]

On Thu, 2005-04-28 at 16:18, Sean Hefty wrote:
> Hal Rosenstock wrote:
> 
> > Should the user registration check that RMPP is allowed for that
> > management class (being registered) ? (It seems to me that allowing the
> > user to enable RMPP on a management class which does not support RMPP
> > might be dangerous).
> > 
> > If so, the list would be SA (class 3) and vendor range 2 (0x30-0x4f).
> > Correct ?
> 
> I'm not sure that letting a user take over a management class that 
> doesn't usually support RMPP would necessarily be dangerous; it just 
> may not work for the user.  

I'm not sure either but...

There's a difference between doesn't usually support it and isn't
supposed to support it.

> For the most part, the RMPP relies on the 
> registration request to determine when to invoke RMPP.

> The exception to this is that the code needs to calculate the offset of 
> the user data separate from the common MAD headers.  This is done in 
> the data_offset() function in mad_rmpp.c.

So do you think nothing bad would happen (other than perhaps to that
user) ? I was concerned about both transmit and receive and whether it
is just better to protect against this. There's a downside in that if
additional classes support RMPP then the code needs updating...

Is it worth checking for this ?

> The classes that you mention above are the only classes that I know of 
> that have RMPP defined.

Thanks.

-- Hal

> - Sean