crypto(9) choose another driver if we cannot open a session on it

[Patrick Lamaizière]

Le Mon, 8 Dec 2008 21:21:55 +0100,
Philip Paeps <philip at freebsd.org> a écrit :

Hello,

> On 2008-12-07 22:45:51 (+0100), Patrick Lamaizière
> <patfbsd at davenulle.org> wrote:
> > I wrote a small patch to allow the crypto framework to choose
> > another cryptographic driver if we cannot open a session on the
> > driver.
> 
> Very cool. :-)  I've been hacking on this too, mainly to get rid of
> the code duplication that currently exists.

Which code exactly? Yes I'm curious :-)

I'm thinking about how to remove the need for a device to support all
the algorithms when we open a session. By using a fake "crypto
virtual device" to open and dispatch crypto requests to real devices or
to cryptosoft. But i don't have any code to show yet.

There is one thing I'm asking about crypto(9):
- I doubt that the migration of a session is safe and I think that
would be far easier to prevent a driver to unregister when there are
some pending sessions on it? glxsb and padlock do not allow to
unregister in this case. 

I've looked quickly the code of geli or ipsec. If the crypto
framework returns EAGAIN because the migration of the session, they
restart a crypto_dispatch(crp) but the datas in crp->crp_buf can be
corrupted by the previous crypto operation (IMHO, may be i've missed
something)?

Thanks, regards.