From mboxrd@z Thu Jan 1 00:00:00 1970 From: sfeldma@gmail.com Subject: [RFC PATCH net-next v2 1/5] net: don't reforward packets already forwarded by offload device Date: Wed, 17 Jun 2015 14:53:10 -0700 Message-ID: <1434577994-22409-2-git-send-email-sfeldma@gmail.com> References: <1434577994-22409-1-git-send-email-sfeldma@gmail.com> Cc: jiri@resnulli.us, simon.horman@netronome.com, roopa@cumulusnetworks.com, ronen.arad@intel.com, john.r.fastabend@intel.com, andrew@lunn.ch, f.fainelli@gmail.com, linux@roeck-us.net, davidch@broadcom.com, stephen@networkplumber.org To: netdev@vger.kernel.org Return-path: Received: from mail-pd0-f177.google.com ([209.85.192.177]:34106 "EHLO mail-pd0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753453AbbFQVvS (ORCPT ); Wed, 17 Jun 2015 17:51:18 -0400 Received: by pdbki1 with SMTP id ki1so49971253pdb.1 for ; Wed, 17 Jun 2015 14:51:18 -0700 (PDT) In-Reply-To: <1434577994-22409-1-git-send-email-sfeldma@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Scott Feldman Just before queuing skb for xmit on port, check if skb has been marked by switchdev port driver as already fordwarded by device. If so, drop skb. A non-zero skb->offload_fwd_mark field is set by the switchdev port driver/device on ingress to indicate the skb has already been forwarded by the device to egress ports with matching dev->skb_mark. The switchdev port driver would assign a non-zero dev->skb_mark for each device port netdev during registration, for example. Signed-off-by: Scott Feldman --- include/linux/netdevice.h | 6 ++++++ include/linux/skbuff.h | 4 ++++ net/core/dev.c | 10 ++++++++++ 3 files changed, 20 insertions(+) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index e20979d..7be616e1 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1448,6 +1448,8 @@ enum netdev_priv_flags { * * @xps_maps: XXX: need comments on this one * + * @offload_fwd_mark: Offload device fwding mark + * * @trans_start: Time (in jiffies) of last Tx * @watchdog_timeo: Represents the timeout that is used by * the watchdog ( see dev_watchdog() ) @@ -1685,6 +1687,10 @@ struct net_device { struct xps_dev_maps __rcu *xps_maps; #endif +#ifdef CONFIG_NET_SWITCHDEV + u32 offload_fwd_mark; +#endif + /* These may be needed for future network-power-down code. */ /* diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index d6cdd6e..1533c4f 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -506,6 +506,7 @@ static inline u32 skb_mstamp_us_delta(const struct skb_mstamp *t1, * @no_fcs: Request NIC to treat last 4 bytes as Ethernet FCS * @napi_id: id of the NAPI struct this skb came from * @secmark: security marking + * @offload_fwd_mark: fwding offload mark * @mark: Generic packet mark * @vlan_proto: vlan encapsulation protocol * @vlan_tci: vlan tag control information @@ -653,6 +654,9 @@ struct sk_buff { #ifdef CONFIG_NETWORK_SECMARK __u32 secmark; #endif +#ifdef CONFIG_NET_SWITCHDEV + __u32 offload_fwd_mark; +#endif union { __u32 mark; __u32 reserved_tailroom; diff --git a/net/core/dev.c b/net/core/dev.c index 6778a99..9eb517e 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3065,6 +3065,16 @@ static int __dev_queue_xmit(struct sk_buff *skb, void *accel_priv) else skb_dst_force(skb); +#ifdef CONFIG_NET_SWITCHDEV + /* Don't forward if offload device already forwarded */ + if (skb->offload_fwd_mark && + skb->offload_fwd_mark == dev->offload_fwd_mark) { + consume_skb(skb); + rc = NET_XMIT_SUCCESS; + goto out; + } +#endif + txq = netdev_pick_tx(dev, skb, accel_priv); q = rcu_dereference_bh(txq->qdisc); -- 1.7.10.4