Re: Linux needs flexible security

Matthew Wilcox (Matthew.Wilcox@genedata.com)
Fri, 26 Nov 1999 11:30:27 +0100


On Thu, Nov 25, 1999 at 11:25:14AM +0100, Pavel Machek wrote:
> Hi!
>
> > > Ioctls should be banned. They make network transparent remote exec
> > > hard, for example. Disabling all ioctls for user-level applications
> > > should not hurt too much.... [clapity clap] Hmm, it will: console
> > > operations are done using ioctls. Ok, disallowing ioctls is not possible.
> >
> > plan9 solved this with ctl files. i don't see why linux shouldn't move
> > the same way in order to reap the benefits of distributable computing.
> > how do systems like mosix work around ioctl problems?
>
> Callbacks: you send ioctl over network and if remote side needs to
> peek memory, sends "I want to peek at address" over network.

yick. nasty.

> Pavel
> PS: Yes, plan-9 like solution would be nicer. Even newioctl(fd, ptr,
> length) would be nicer :-).

Hmm..

ssize_t write(int fd, const void *buf, size_t count);
vs
newioctl(fd, ptr, length);

:-)

Maybe we should have `writectl' and `readctl' calls on an fd so that we
don't need to have separate ctl files?

-- 
Matthew Wilcox <willy@bofh.ai>
"Windows and MacOS are products, contrived by engineers in the service of
specific companies. Unix, by contrast, is not so much a product as it is a
painstakingly compiled oral history of the hacker subculture." - N Stephenson

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