From 0c4f691ff6791e55ac831666df0b49b1679c56e4 Mon Sep 17 00:00:00 2001 From: Scott Feldman Date: Sat, 18 Jul 2015 18:24:48 -0700 Subject: [PATCH] net: don't reforward packets already forwarded by offload device 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->offload_skb_mark for each device port netdev during registration, for example. Signed-off-by: Scott Feldman Acked-by: Jiri Pirko Acked-by: Roopa Prabhu Acked-by: Nicolas Dichtel Signed-off-by: David S. Miller --- include/linux/netdevice.h | 6 ++++++ include/linux/skbuff.h | 9 ++++++++- net/core/dev.c | 10 ++++++++++ 3 files changed, 24 insertions(+), 1 deletion(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 45cfd797eb77..8364f29e08be 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1456,6 +1456,8 @@ 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() ) @@ -1697,6 +1699,10 @@ 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 d6cdd6e87d53..af7a09650fa2 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 @@ -650,9 +651,15 @@ struct sk_buff { unsigned int sender_cpu; }; #endif + union { #ifdef CONFIG_NETWORK_SECMARK - __u32 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 8810b6bbebfe..2ee15afb412d 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3061,6 +3061,16 @@ 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);