netdev - Re: [PATCH 01/10] core: Split out UFO6 support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 18 Dec 2014 19:50:02 +0200
From:	"Michael S. Tsirkin" <mst@...hat.com>
To:	Vlad Yasevich <vyasevic@...hat.com>
Cc:	Vladislav Yasevich <vyasevich@...il.com>, netdev@...r.kernel.org,
	virtualization@...ts.linux-foundation.org, ben@...adent.org.uk,
	stefanha@...hat.com, David Miller <davem@...emloft.net>
Subject: Re: [PATCH 01/10] core: Split out UFO6 support

On Thu, Dec 18, 2014 at 07:35:46PM +0200, Michael S. Tsirkin wrote:
> > > We should either generate our own ID,
> > > like we always did, or make sure we don't accept
> > > these packets.
> > > Second option is almost sure to break userspace,
> > > so it seems we must do the first one.
> > > 
> > 
> > Right.  This was missing from packet sockets.  I can fix it.
> > 
> > -vlad
> 
> Also, this can't be a patch on top, since we don't
> want bisect to give us configurations which
> can BUG().

So how doing this in stages:

1. add helper that checks skb GSO type.
If it is SKB_GSO_UDP, check for IPv6, and
generate the fragment ID.

Call this helper in
	- virtio net rx path
	- tun rx path (get user)
	- macvtap tx patch (get user)
	- packet socket tx patch (get user)

2. Put back UFO flag everywhere: virtio,tun,macvtap,packet,
since we can handle IPv6 now even if it's suboptimal.

Above two seem like smalling patches, appropriate for stable.

Next, work on a new feature to pass
fragment ID in virtio header:

3. split UFO/UFO6 as you did here, but add code
in above 4 places to convert UDP to UDP6,
additionally, add code in
	- virtio net tx path
	- tun tx path (get user)
	- macvtap rx patch (put user)
	- packet socket rx patch (put user)
to convert UDP6 to UDP.

	step 3 needs to be bisect-clean, somehow.

4. add new field in header, new feature bit for virtio net to gate it,
new ioctls to tun,macvtap,packet socket.

These two are more like optimizations, so not stable material.


-- 
MST
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html