From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH 1/3] ipv6: Select fragment id during UFO/GSO segmentation if not set. Date: Tue, 27 Jan 2015 10:42:08 +0200 Message-ID: <20150127084208.GB21584@redhat.com> References: <1422283026-27832-1-git-send-email-vyasevic@redhat.com> <1422283026-27832-2-git-send-email-vyasevic@redhat.com> <1422326874.31046.239.camel@decadent.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Vladislav Yasevich , netdev@vger.kernel.org, virtualization@lists.linux-foundation.org, edumazet@google.com, Vladislav Yasevich To: Ben Hutchings Return-path: Received: from mx1.redhat.com ([209.132.183.28]:50704 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751553AbbA0ImU (ORCPT ); Tue, 27 Jan 2015 03:42:20 -0500 Content-Disposition: inline In-Reply-To: <1422326874.31046.239.camel@decadent.org.uk> Sender: netdev-owner@vger.kernel.org List-ID: 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 > > Signed-off-by: Vladislav Yasevich > > --- > > 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". > -- > Ben Hutchings > When in doubt, use brute force. - Ken Thompson