net: deliver skbs on inactive slaves to exact matches (597a264b) · Commits · 戴 / test

Currently, the accelerated receive path for VLAN's will drop packets if the real device is an inactive slave and is not one of the special pkts tested for in skb_bond_should_drop(). This behavior is different then the non-accelerated path and for pkts over a bonded vlan. For example, vlanx -> bond0 -> ethx will be dropped in the vlan path and not delivered to any packet handlers at all. However, bond0 -> vlanx -> ethx and bond0 -> ethx will be delivered to handlers that match the exact dev, because the VLAN path checks the real_dev which is not a slave and netif_recv_skb() doesn't drop frames but only delivers them to exact matches. This patch adds a sk_buff flag which is used for tagging skbs that would previously been dropped and allows the skb to continue to skb_netif_recv(). Here we add logic to check for the deliver_no_wcard flag and if it is set only deliver to handlers that match exactly. This makes both paths above consistent and gives pkt handlers a way to identify skbs that come from inactive slaves. Without this patch in some configurations skbs will be delivered to handlers with exact matches and in others be dropped out right in the vlan path. I have tested the following 4 configurations in failover modes and load balancing modes. # bond0 -> ethx # vlanx -> bond0 -> ethx # bond0 -> vlanx -> ethx # bond0 -> ethx | vlanx -> -- Signed-off-by:

John Fastabend <john.r.fastabend@intel.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

include/linux/skbuff.h

+4 −1

Original line number	Diff line number	Diff line
		@@ -380,7 +380,10 @@ struct sk_buff {
		kmemcheck_bitfield_begin(flags2);
		__u16 queue_mapping:16;
		#ifdef CONFIG_IPV6_NDISC_NODETYPE
		__u8 ndisc_nodetype:2;
		__u8 ndisc_nodetype:2,
		deliver_no_wcard:1;
		#else
		__u8 deliver_no_wcard:1;
		#endif
		kmemcheck_bitfield_end(flags2);

net/8021q/vlan_core.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -12,7 +12,7 @@ int __vlan_hwaccel_rx(struct sk_buff skb, struct vlan_group grp,
		return NET_RX_DROP;

		if (skb_bond_should_drop(skb, ACCESS_ONCE(skb->dev->master)))
		goto drop;
		skb->deliver_no_wcard = 1;

		skb->skb_iif = skb->dev->ifindex;
		__vlan_hwaccel_put_tag(skb, vlan_tci);
		@@ -84,7 +84,7 @@ vlan_gro_common(struct napi_struct napi, struct vlan_group grp,
		struct sk_buff *p;

		if (skb_bond_should_drop(skb, ACCESS_ONCE(skb->dev->master)))
		goto drop;
		skb->deliver_no_wcard = 1;

		skb->skb_iif = skb->dev->ifindex;
		__vlan_hwaccel_put_tag(skb, vlan_tci);

net/core/dev.c

+14 −3

Original line number	Diff line number	Diff line
		@@ -2810,13 +2810,24 @@ static int __netif_receive_skb(struct sk_buff *skb)
		if (!skb->skb_iif)
		skb->skb_iif = skb->dev->ifindex;

		/*
		* bonding note: skbs received on inactive slaves should only
		* be delivered to pkt handlers that are exact matches. Also
		* the deliver_no_wcard flag will be set. If packet handlers
		* are sensitive to duplicate packets these skbs will need to
		* be dropped at the handler. The vlan accel path may have
		* already set the deliver_no_wcard flag.
		*/
		null_or_orig = NULL;
		orig_dev = skb->dev;
		master = ACCESS_ONCE(orig_dev->master);
		if (master) {
		if (skb_bond_should_drop(skb, master))
		if (skb->deliver_no_wcard)
		null_or_orig = orig_dev;
		else if (master) {
		if (skb_bond_should_drop(skb, master)) {
		skb->deliver_no_wcard = 1;
		null_or_orig = orig_dev; /* deliver only exact match */
		else
		} else
		skb->dev = master;
		}

Admin message