Subject: Re: How kauth can make meaningful decisions about passthru ioctls
To: Steven M. Bellovin <>
From: Elad Efrat <>
List: tech-kern
Date: 11/30/2006 15:53:31
Steven M. Bellovin wrote:
> On Thu, 30 Nov 2006 15:10:25 +0200
> Elad Efrat <> wrote:
>> Thor Lancelot Simon wrote:
>>> Sure.  We're concerned about what the ioctl being passed-through
>>> could cause the device to do.  Think about what amr(4) would have
>>> to do if it didn't know how to parse the sub-commands: it'd have to
>>> tell the listener "it could be any of these: ..." .
>>> We could, I suppose, order the commands from "safest" to "most
>>> dangerous" and require that the question indicate the "most
>>> dangerous".  But what's "more dangerous", writing the device data
>>> or writing the device configuration?  I think a similar issue
>>> exists even for read.
>> sounds logical. unless someone objects, I'll come up with a diff.
> What sounds logical?  An ordering?  I don't think it makes much sense
> at all.  What's wrong with a bitmask? 

sorry if I wasn't clear: thor's explanation as to why we should use
a bit-field sounds logical, and I agree that it's what we should do.


Elad Efrat