On Di, 2015-01-27 at 10:42 +0200, Michael S. Tsirkin wrote:
> On Tue, Jan 27, 2015 at 02:47:54AM +0000, Ben Hutchings wrote:
> > On Mon, 2015-01-26 at 09:37 -0500, Vladislav Yasevich wrote:
> > > If the IPv6 fragment id has not been set and we perform
> > > fragmentation due to UFO, select a new fragment id.
> > > When we store the fragment id into skb_shinfo, set the bit
> > > in the skb so we can re-use the selected id.
> > > This preserves the behavior of UFO packets generated on the
> > > host and solves the issue of id generation for packet sockets
> > > and tap/macvtap devices.
> > >
> > > This patch moves ipv6_select_ident() back in to the header file.
> > > It also provides the helper function that sets skb_shinfo() frag
> > > id and sets the bit.
> > >
> > > It also makes sure that we select the fragment id when doing
> > > just gso validation, since it's possible for the packet to
> > > come from an untrusted source (VM) and be forwarded through
> > > a UFO enabled device which will expect the fragment id.
> > >
> > > CC: Eric Dumazet <edumazet@xxxxxxxxxx>
> > > Signed-off-by: Vladislav Yasevich <vyasevic@xxxxxxxxxx>
> > > ---
> > > include/linux/skbuff.h | 3 ++-
> > > include/net/ipv6.h | 2 ++
> > > net/ipv6/ip6_output.c | 4 ++--
> > > net/ipv6/output_core.c | 9 ++++++++-
> > > net/ipv6/udp_offload.c | 10 +++++++++-
> > > 5 files changed, 23 insertions(+), 5 deletions(-)
> > >
> > > diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
> > > index 85ab7d7..3ad5203 100644
> > > --- a/include/linux/skbuff.h
> > > +++ b/include/linux/skbuff.h
> > > @@ -605,7 +605,8 @@ struct sk_buff {
> > > __u8 ipvs_property:1;
> > > __u8 inner_protocol_type:1;
> > > __u8 remcsum_offload:1;
> > > - /* 3 or 5 bit hole */
> > > + __u8 ufo_fragid_set:1;
> > [...]
> >
> > Doesn't the flag belong in struct skb_shared_info, rather than struct
> > sk_buff? Otherwise this looks fine.
> >
> > Ben.
>
> Hmm we seem to be out of tx flags.
> Maybe ip6_frag_id == 0 should mean "not set".
Maybe that is the best idea. Definitely the ufo_fragid_set bit should
move into the skb_shared_info area.
Thanks,
Hannes
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