netdev - [PATCH net-next] net: validate_xmit

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Date:	Tue, 12 Apr 2016 21:50:07 -0700
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	David Miller <davem@...emloft.net>
Cc:	netdev <netdev@...r.kernel.org>
Subject: [PATCH net-next] net: validate_xmit_skb() changes

From: Eric Dumazet <edumazet@...gle.com>

skbs given to validate_xmit_skb() should not have a next
pointer anymore.

Also if a packet is dropped, increment dev->tx_dropped
__dev_queue_xmit() no longer has to change tx_dropped in this case.

Signed-off-by: Eric Dumazet <edumazet@...gle.com>
---
 net/core/dev.c |    7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index d51343a821ed..85e808f977f5 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2915,9 +2915,6 @@ static struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device
 {
 	netdev_features_t features;
 
-	if (skb->next)
-		return skb;
-
 	features = netif_skb_features(skb);
 	skb = validate_xmit_vlan(skb, features);
 	if (unlikely(!skb))
@@ -2960,6 +2957,7 @@ static struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device
 out_kfree_skb:
 	kfree_skb(skb);
 out_null:
+	atomic_long_inc(&dev->tx_dropped);
 	return NULL;
 }
 
@@ -3349,7 +3347,7 @@ static int __dev_queue_xmit(struct sk_buff *skb, void *accel_priv)
 
 			skb = validate_xmit_skb(skb, dev);
 			if (!skb)
-				goto drop;
+				goto out;
 
 			HARD_TX_LOCK(dev, txq, cpu);
 
@@ -3376,7 +3374,6 @@ recursion_alert:
 	}
 
 	rc = -ENETDOWN;
-drop:
 	rcu_read_unlock_bh();
 
 	atomic_long_inc(&dev->tx_dropped);