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Commit 6a32e4f9 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

vlan: allow nested vlan_do_receive() 



commit 2425717b (net: allow vlan traffic to be received under bond)
broke ARP processing on vlan on top of bonding.

       +-------+
eth0 --| bond0 |---bond0.103
eth1 --|       |
       +-------+

52870.115435: skb_gro_reset_offset <-napi_gro_receive
52870.115435: dev_gro_receive <-napi_gro_receive
52870.115435: napi_skb_finish <-napi_gro_receive
52870.115435: netif_receive_skb <-napi_skb_finish
52870.115435: get_rps_cpu <-netif_receive_skb
52870.115435: __netif_receive_skb <-netif_receive_skb
52870.115436: vlan_do_receive <-__netif_receive_skb
52870.115436: bond_handle_frame <-__netif_receive_skb
52870.115436: vlan_do_receive <-__netif_receive_skb
52870.115436: arp_rcv <-__netif_receive_skb
52870.115436: kfree_skb <-arp_rcv

Packet is dropped in arp_rcv() because its pkt_type was set to
PACKET_OTHERHOST in the first vlan_do_receive() call, since no eth0.103
exists.

We really need to change pkt_type only if no more rx_handler is about to
be called for the packet.

Signed-off-by: default avatarEric Dumazet <eric.dumazet@gmail.com>
Reviewed-by: default avatarJiri Pirko <jpirko@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 14ef37b6

include/linux/if_vlan.h

+3 −3
Original line number Diff line number Diff line
@@ -106,7 +106,7 @@ extern struct net_device *__vlan_find_dev_deep(struct net_device *real_dev, 
extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);

extern u16 vlan_dev_vlan_id(const struct net_device *dev);



extern bool vlan_do_receive(struct sk_buff **skb);

extern bool vlan_do_receive(struct sk_buff **skb, bool last_handler);

extern struct sk_buff *vlan_untag(struct sk_buff *skb);



#else
@@ -128,9 +128,9 @@ static inline u16 vlan_dev_vlan_id(const struct net_device *dev) 
	return 0;

}



static inline bool vlan_do_receive(struct sk_buff **skb)

static inline bool vlan_do_receive(struct sk_buff **skb, bool last_handler)

{

	if ((*skb)->vlan_tci & VLAN_VID_MASK)

	if (((*skb)->vlan_tci & VLAN_VID_MASK) && last_handler)

		(*skb)->pkt_type = PACKET_OTHERHOST;

	return false;

}

net/8021q/vlan_core.c

+5 −2
Original line number Diff line number Diff line
@@ -4,7 +4,7 @@ 
#include <linux/netpoll.h>

#include "vlan.h"



bool vlan_do_receive(struct sk_buff **skbp)

bool vlan_do_receive(struct sk_buff **skbp, bool last_handler)

{

	struct sk_buff *skb = *skbp;

	u16 vlan_id = skb->vlan_tci & VLAN_VID_MASK;
@@ -13,7 +13,10 @@ bool vlan_do_receive(struct sk_buff **skbp) 


	vlan_dev = vlan_find_dev(skb->dev, vlan_id);

	if (!vlan_dev) {

		if (vlan_id)

		/* Only the last call to vlan_do_receive() should change

		 * pkt_type to PACKET_OTHERHOST

		 */

		if (vlan_id && last_handler)

			skb->pkt_type = PACKET_OTHERHOST;

		return false;

	}

net/core/dev.c

+2 −2
Original line number Diff line number Diff line
@@ -3283,18 +3283,18 @@ static int __netif_receive_skb(struct sk_buff *skb) 
ncls:

#endif



	rx_handler = rcu_dereference(skb->dev->rx_handler);

	if (vlan_tx_tag_present(skb)) {

		if (pt_prev) {

			ret = deliver_skb(skb, pt_prev, orig_dev);

			pt_prev = NULL;

		}

		if (vlan_do_receive(&skb))

		if (vlan_do_receive(&skb, !rx_handler))

			goto another_round;

		else if (unlikely(!skb))

			goto out;

	}



	rx_handler = rcu_dereference(skb->dev->rx_handler);

	if (rx_handler) {

		if (pt_prev) {

			ret = deliver_skb(skb, pt_prev, orig_dev);