Message ID | 1434218670-43821-2-git-send-email-sfeldma@gmail.com |
---|---|
State | RFC, archived |
Delegated to: | David Miller |
Headers | show |
Sat, Jun 13, 2015 at 08:04:27PM CEST, sfeldma@gmail.com wrote: >From: Scott Feldman <sfeldma@gmail.com> > >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->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 <sfeldma@gmail.com> >--- > include/linux/netdevice.h | 6 ++++++ > include/linux/skbuff.h | 4 ++++ > net/core/dev.c | 9 +++++++++ > 3 files changed, 19 insertions(+) > >diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h >index 6f5f71f..181b08f 100644 >--- a/include/linux/netdevice.h >+++ b/include/linux/netdevice.h >@@ -1444,6 +1444,8 @@ enum netdev_priv_flags { > * > * @xps_maps: XXX: need comments on this one > * >+ * @fwd_mark: Offload device fwding mark >+ * How about to say this is an offloading/switchdev stuff? "offload_fwd_mark" ? <snip> >diff --git a/net/core/dev.c b/net/core/dev.c >index 6778a99..558bf33 100644 >--- a/net/core/dev.c >+++ b/net/core/dev.c >@@ -3065,6 +3065,15 @@ 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->fwd_mark && skb->fwd_mark == dev->fwd_mark) { >+ kfree_skb(skb); You should use consume_skb here to do not indicate skb was dropped after failure. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 6/13/15, 11:04 AM, sfeldma@gmail.com wrote: > diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h > index 6f5f71f..181b08f 100644 > --- a/include/linux/netdevice.h > +++ b/include/linux/netdevice.h > @@ -1444,6 +1444,8 @@ enum netdev_priv_flags { > * > * @xps_maps: XXX: need comments on this one > * > + * @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() ) > @@ -1681,6 +1683,10 @@ struct net_device { > struct xps_dev_maps __rcu *xps_maps; > #endif > > +#ifdef CONFIG_NET_SWITCHDEV > + u32 fwd_mark; > +#endif > + > scott, Just calling out a few other use-cases to make sure this flag can be used in a generic way in the future: - avoid updating acl counters in the kernel when hardware acl counters have already accounted for this packet - ability to conditionally clear the mark by other protocols in the kernel before xmit: one use case is the bridge driver allowing software forwarding of some protocol packets when hardware forwarding of these is turned off eg igmp (As I understand, This is possible with your patch series if we need to in the future) PS: Maybe the name should be generic enough to suite other use-cases in the future (i like the name i had hw_offloaded better ;). -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 6f5f71f..181b08f 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -1444,6 +1444,8 @@ enum netdev_priv_flags { * * @xps_maps: XXX: need comments on this one * + * @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() ) @@ -1681,6 +1683,10 @@ struct net_device { struct xps_dev_maps __rcu *xps_maps; #endif +#ifdef CONFIG_NET_SWITCHDEV + u32 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 cc612fc..ba98c05 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -501,6 +501,7 @@ 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 + * @fwd_mark: fwding offload mark * @mark: Generic packet mark * @vlan_proto: vlan encapsulation protocol * @vlan_tci: vlan tag control information @@ -648,6 +649,9 @@ struct sk_buff { #ifdef CONFIG_NETWORK_SECMARK __u32 secmark; #endif +#ifdef CONFIG_NET_SWITCHDEV + __u32 fwd_mark; +#endif union { __u32 mark; __u32 reserved_tailroom; diff --git a/net/core/dev.c b/net/core/dev.c index 6778a99..558bf33 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3065,6 +3065,15 @@ 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->fwd_mark && skb->fwd_mark == dev->fwd_mark) { + kfree_skb(skb); + rc = NET_XMIT_SUCCESS; + goto out; + } +#endif + txq = netdev_pick_tx(dev, skb, accel_priv); q = rcu_dereference_bh(txq->qdisc);