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: Wed, 12 Nov 2014 12:59:33 +0100 Message-ID: <20141112115933.GD1882@nanopsycho.orion> References: <1415700789-9171-1-git-send-email-jiri@resnulli.us> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev , David Miller , Jamal Hadi Salim , Tom Herbert , Eric Dumazet , willemb@google.com, Daniel Borkmann , mst@redhat.com, fw@strlen.de, Paul.Durrant@citrix.com, Thomas Graf To: Pravin Shelar Return-path: Received: from mail-wg0-f50.google.com ([74.125.82.50]:59014 "EHLO mail-wg0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751507AbaKLL7g (ORCPT ); Wed, 12 Nov 2014 06:59:36 -0500 Received: by mail-wg0-f50.google.com with SMTP id z12so13907135wgg.9 for ; Wed, 12 Nov 2014 03:59:34 -0800 (PST) Content-Disposition: inline In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: Tue, Nov 11, 2014 at 06:24:15PM CET, pshelar@nicira.com wrote: >On Tue, Nov 11, 2014 at 2:13 AM, 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; >> + >> + if (skb->ip_summed == CHECKSUM_COMPLETE) >> + skb->csum = csum_sub(skb->csum, csum_partial(skb->data >> + + (2 * ETH_ALEN), VLAN_HLEN, 0)); >> + >> + vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN); >> + *vlan_tci = ntohs(vhdr->h_vlan_TCI); >> + >> + memmove(skb->data + VLAN_HLEN, skb->data, 2 * ETH_ALEN); >> + __skb_pull(skb, VLAN_HLEN); >> + >> + vlan_set_encap_proto(skb, vhdr); >> + skb->mac_header += VLAN_HLEN; >> + if (skb_network_offset(skb) < ETH_HLEN) >> + skb_set_network_header(skb, ETH_HLEN); >> + skb_reset_mac_len(skb); >> + >> + return 0; >> +} >> + >> +int skb_vlan_pop(struct sk_buff *skb) >> +{ >> + u16 vlan_tci; >> + __be16 vlan_proto; >> + int err; >> + >> + if (likely(vlan_tx_tag_present(skb))) { >> + skb->vlan_tci = 0; >> + } else { >> + if (unlikely((skb->protocol != htons(ETH_P_8021Q) && >> + skb->protocol != htons(ETH_P_8021AD)) || >> + skb->len < VLAN_ETH_HLEN)) >> + return 0; >> + >> + err = __skb_vlan_pop(skb, &vlan_tci); >> + if (err) >> + return err; >> + } >> + /* move next vlan tag to hw accel tag */ >> + if (likely((skb->protocol != htons(ETH_P_8021Q) && >> + skb->protocol != htons(ETH_P_8021AD)) || >> + skb->len < VLAN_ETH_HLEN)) >> + return 0; >> + >> + vlan_proto = skb->protocol; >> + err = __skb_vlan_pop(skb, &vlan_tci); >> + if (unlikely(err)) >> + return err; >> + >> + __vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci); >> + return 0; >> +} >> +EXPORT_SYMBOL(skb_vlan_pop); >> + >> +int skb_vlan_push(struct sk_buff *skb, __be16 vlan_proto, u16 vlan_tci) >> +{ >> + if (vlan_tx_tag_present(skb)) { >> + /* push down current VLAN tag */ >> + if (!__vlan_put_tag(skb, skb->vlan_proto, >> + vlan_tx_tag_get(skb))) >> + return -ENOMEM; >> + >Since you are restructuring this code, can you also change >__vlan_put_tag() to not free skb on error. So that these two new >functions can have common error handling code. That is not directly related to this patchset. I believe that should be changed in separate patch later on.