From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Pirko Subject: Re: [patch net-next v4 8/9] net: move vlan pop/push functions into common code Date: Fri, 21 Nov 2014 19:05:53 +0100 Message-ID: <20141121180553.GA2251@nanopsycho.orion> References: <1416402303-25341-1-git-send-email-jiri@resnulli.us> <1416402303-25341-9-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 , Willem de Bruijn , Daniel Borkmann , mst@redhat.com, fw@strlen.de, Paul.Durrant@citrix.com, Thomas Graf , Cong Wang To: Pravin Shelar Return-path: Received: from mail-wi0-f175.google.com ([209.85.212.175]:35190 "EHLO mail-wi0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750770AbaKUSGA (ORCPT ); Fri, 21 Nov 2014 13:06:00 -0500 Received: by mail-wi0-f175.google.com with SMTP id l15so45906wiw.8 for ; Fri, 21 Nov 2014 10:05:59 -0800 (PST) Content-Disposition: inline In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: Fri, Nov 21, 2014 at 05:11:39PM CET, pshelar@nicira.com wrote: >On Wed, Nov 19, 2014 at 5:05 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 >> --- >> >> v3->v4: >> - don't try to be smart and copy skb->mac_len manipulation as it is. It can be >> adjusted later on. > >I am fine with moving this code to generic library, as long as we can >adjust the mac_len as offset for MPLS header, otherwise this breaks >MPLS support. Pravin, I'm just moving the code without changing it in this aspect. Maybe I'm missing something but can you tell me what you see wrong? Thanks. > >> - fix error path in do_execute_actions as suggested by Pravin >> v2->v3: >> - used previously introduced __vlan_insert_tag helper >> - used skb_push/pull to get skb->data into needed point >> - fixed skb->mac_len computation in skb_vlan_push pointed out by Pravin >> v1->v2: >> - adjusted to fix recent ovs changes >> - included change to use make_writable suggested by Eric >> >> include/linux/skbuff.h | 2 + >> net/core/skbuff.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++ >> net/openvswitch/actions.c | 86 +++++------------------------------------- >> 3 files changed, 106 insertions(+), 77 deletions(-) >> >> diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h >> index e045516..78c299f 100644 >> --- a/include/linux/skbuff.h >> +++ b/include/linux/skbuff.h >> @@ -2679,6 +2679,8 @@ 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_ensure_writable(struct sk_buff *skb, int write_len); >> +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 d11bbe0..c906c5f 100644 >> --- a/net/core/skbuff.c >> +++ b/net/core/skbuff.c >> @@ -4163,6 +4163,101 @@ int skb_ensure_writable(struct sk_buff *skb, int write_len) >> } >> EXPORT_SYMBOL(skb_ensure_writable); >> >> +/* 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; >> + unsigned int offset = skb->data - skb_mac_header(skb); >> + int err; >> + >> + __skb_push(skb, offset); >> + err = skb_ensure_writable(skb, VLAN_ETH_HLEN); >> + if (unlikely(err)) >> + goto pull; >> + >> + skb_postpull_rcsum(skb, skb->data + (2 * ETH_ALEN), VLAN_HLEN); >> + >> + 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); >> +pull: >> + __skb_pull(skb, offset); >> + >> + return err; >> +} >> + >> +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)) { >> + unsigned int offset = skb->data - skb_mac_header(skb); >> + int err; >> + >> + /* __vlan_insert_tag expect skb->data pointing to mac header. >> + * So change skb->data before calling it and change back to >> + * original position later >> + */ >> + __skb_push(skb, offset); >> + err = __vlan_insert_tag(skb, skb->vlan_proto, >> + vlan_tx_tag_get(skb)); >> + if (err) >> + return err; >> + skb->protocol = skb->vlan_proto; >> + skb->mac_len += VLAN_HLEN; >> + __skb_pull(skb, offset); >> + >> + if (skb->ip_summed == CHECKSUM_COMPLETE) >> + skb->csum = csum_add(skb->csum, csum_partial(skb->data >> + + (2 * ETH_ALEN), VLAN_HLEN, 0)); >> + } >> + __vlan_hwaccel_put_tag(skb, vlan_proto, vlan_tci); >> + return 0; >> +} >> +EXPORT_SYMBOL(skb_vlan_push); >> + >> /** >> * alloc_skb_with_frags - allocate skb with page frags >> * >> diff --git a/net/openvswitch/actions.c b/net/openvswitch/actions.c >> index 7ffa377..4e05ea1 100644 >> --- a/net/openvswitch/actions.c >> +++ b/net/openvswitch/actions.c >> @@ -206,93 +206,27 @@ static int set_mpls(struct sk_buff *skb, struct sw_flow_key *key, >> return 0; >> } >> >> -/* remove VLAN header from packet and update csum accordingly. */ >> -static int __pop_vlan_tci(struct sk_buff *skb, __be16 *current_tci) >> -{ >> - struct vlan_hdr *vhdr; >> - int err; >> - >> - err = skb_ensure_writable(skb, VLAN_ETH_HLEN); >> - if (unlikely(err)) >> - return err; >> - >> - skb_postpull_rcsum(skb, skb->data + (2 * ETH_ALEN), VLAN_HLEN); >> - >> - vhdr = (struct vlan_hdr *)(skb->data + ETH_HLEN); >> - *current_tci = 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); >> - >> - /* Update mac_len for subsequent MPLS actions */ >> - skb_reset_mac_len(skb); >> - return 0; >> -} >> - >> static int pop_vlan(struct sk_buff *skb, struct sw_flow_key *key) >> { >> - __be16 tci; >> int err; >> >> - if (likely(vlan_tx_tag_present(skb))) { >> - skb->vlan_tci = 0; >> - } else { >> - if (unlikely(skb->protocol != htons(ETH_P_8021Q) || >> - skb->len < VLAN_ETH_HLEN)) >> - return 0; >> - >> - err = __pop_vlan_tci(skb, &tci); >> - if (err) >> - return err; >> - } >> - /* move next vlan tag to hw accel tag */ >> - if (likely(skb->protocol != htons(ETH_P_8021Q) || >> - skb->len < VLAN_ETH_HLEN)) { >> + err = skb_vlan_pop(skb); >> + if (vlan_tx_tag_present(skb)) >> + invalidate_flow_key(key); >> + else >> key->eth.tci = 0; >> - return 0; >> - } >> - >> - invalidate_flow_key(key); >> - err = __pop_vlan_tci(skb, &tci); >> - if (unlikely(err)) >> - return err; >> - >> - __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), ntohs(tci)); >> - return 0; >> + return err; >> } >> >> static int push_vlan(struct sk_buff *skb, struct sw_flow_key *key, >> const struct ovs_action_push_vlan *vlan) >> { >> - if (unlikely(vlan_tx_tag_present(skb))) { >> - u16 current_tag; >> - >> - /* push down current VLAN tag */ >> - current_tag = vlan_tx_tag_get(skb); >> - >> - skb = vlan_insert_tag_set_proto(skb, skb->vlan_proto, >> - current_tag); >> - if (!skb) >> - return -ENOMEM; >> - /* Update mac_len for subsequent MPLS actions */ >> - skb->mac_len += VLAN_HLEN; >> - >> - if (skb->ip_summed == CHECKSUM_COMPLETE) >> - skb->csum = csum_add(skb->csum, csum_partial(skb->data >> - + (2 * ETH_ALEN), VLAN_HLEN, 0)); >> - >> + if (vlan_tx_tag_present(skb)) >> invalidate_flow_key(key); >> - } else { >> + else >> key->eth.tci = vlan->vlan_tci; >> - } >> - __vlan_hwaccel_put_tag(skb, vlan->vlan_tpid, ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT); >> - return 0; >> + return skb_vlan_push(skb, vlan->vlan_tpid, >> + ntohs(vlan->vlan_tci) & ~VLAN_TAG_PRESENT); >> } >> >> static int set_eth_addr(struct sk_buff *skb, struct sw_flow_key *key, >> @@ -858,8 +792,6 @@ static int do_execute_actions(struct datapath *dp, struct sk_buff *skb, >> >> case OVS_ACTION_ATTR_PUSH_VLAN: >> err = push_vlan(skb, key, nla_data(a)); >> - if (unlikely(err)) /* skb already freed. */ >> - return err; >> break; >> >> case OVS_ACTION_ATTR_POP_VLAN: >> -- >> 1.9.3 >>