From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Pirko Subject: Re: [patch net-next 1/2] net: move vlan pop/push functions into common code Date: Tue, 11 Nov 2014 16:00:16 +0100 Message-ID: <20141111150016.GD1825@nanopsycho.lan> References: <1415700789-9171-1-git-send-email-jiri@resnulli.us> <1415711181.9613.32.camel@edumazet-glaptop2.roam.corp.google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org, davem@davemloft.net, jhs@mojatatu.com, pshelar@nicira.com, therbert@google.com, edumazet@google.com, willemb@google.com, dborkman@redhat.com, mst@redhat.com, fw@strlen.de, Paul.Durrant@citrix.com, tgraf@suug.ch To: Eric Dumazet Return-path: Received: from mail-wg0-f53.google.com ([74.125.82.53]:63796 "EHLO mail-wg0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751537AbaKKPAT (ORCPT ); Tue, 11 Nov 2014 10:00:19 -0500 Received: by mail-wg0-f53.google.com with SMTP id b13so11845244wgh.26 for ; Tue, 11 Nov 2014 07:00:17 -0800 (PST) Content-Disposition: inline In-Reply-To: <1415711181.9613.32.camel@edumazet-glaptop2.roam.corp.google.com> Sender: netdev-owner@vger.kernel.org List-ID: Tue, Nov 11, 2014 at 02:06:21PM CET, eric.dumazet@gmail.com wrote: >On Tue, 2014-11-11 at 11:13 +0100, Jiri Pirko wrote: >> So it can be used from out of openvswitch code. >> Did couple of cosmetic changes on the way, namely variable naming and >> adding support for 8021AD proto. >> >> Signed-off-by: Jiri Pirko >> --- >> include/linux/skbuff.h | 2 ++ >> net/core/skbuff.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++ >> net/openvswitch/actions.c | 76 ++--------------------------------------- >> 3 files changed, 90 insertions(+), 74 deletions(-) >> >> diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h >> index 103fbe8..3b0445c 100644 >> --- a/include/linux/skbuff.h >> +++ b/include/linux/skbuff.h >> @@ -2673,6 +2673,8 @@ void skb_scrub_packet(struct sk_buff *skb, bool xnet); >> unsigned int skb_gso_transport_seglen(const struct sk_buff *skb); >> struct sk_buff *skb_segment(struct sk_buff *skb, netdev_features_t features); >> struct sk_buff *skb_vlan_untag(struct sk_buff *skb); >> +int skb_vlan_pop(struct sk_buff *skb); >> +int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci); >> >> struct skb_checksum_ops { >> __wsum (*update)(const void *mem, int len, __wsum wsum); >> diff --git a/net/core/skbuff.c b/net/core/skbuff.c >> index 7001896..75e53d4 100644 >> --- a/net/core/skbuff.c >> +++ b/net/core/skbuff.c >> @@ -4151,6 +4151,92 @@ err_free: >> } >> EXPORT_SYMBOL(skb_vlan_untag); >> >> +/* remove VLAN header from packet and update csum accordingly. */ >> +static int __skb_vlan_pop(struct sk_buff *skb, u16 *vlan_tci) >> +{ >> + struct vlan_hdr *vhdr; >> + int err; >> + > > > >> + if (!pskb_may_pull(skb, VLAN_ETH_HLEN)) >> + return -ENOMEM; >> + >> + if (!skb_cloned(skb) || skb_clone_writable(skb, VLAN_ETH_HLEN)) >> + return 0; >> + >> + err = pskb_expand_head(skb, 0, 0, GFP_ATOMIC); >> + if (unlikely(err)) >> + return err; > >All this should be a function of its own (OVS calls this >make_writable()). > >Its too bad netfilter has a different skb_make_writable() How different is that? Looking at it it seems it is doing the same thing. Not sure though... > > >> + >> + if (skb->ip_summed == CHECKSUM_COMPLETE) >> + skb->csum = csum_sub(skb->csum, csum_partial(skb->data >> + + (2 * ETH_ALEN), VLAN_HLEN, 0)); > >This looks like skb_postpull_rcsum() > >BTW, calling csum_partial() for 4 bytes is quite expensive. > > >