Commit a1e975e1 authored by Vasily Averin's avatar Vasily Averin Committed by David S. Miller
Browse files

bpf: use skb_expand_head in bpf_out_neigh_v4/6 



Unlike skb_realloc_headroom, new helper skb_expand_head
does not allocate a new skb if possible.

Additionally this patch replaces commonly used dereferencing with variables.

Signed-off-by: default avatarVasily Averin <vvs@virtuozzo.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 53744a4a

net/core/filter.c

+5 −22
Original line number Diff line number Diff line
@@ -2180,18 +2180,10 @@ static int bpf_out_neigh_v6(struct net *net, struct sk_buff *skb, 
	skb->tstamp = 0;



	if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {

		struct sk_buff *skb2;



		skb2 = skb_realloc_headroom(skb, hh_len);

		if (unlikely(!skb2)) {

			kfree_skb(skb);

		skb = skb_expand_head(skb, hh_len);

		if (!skb)

			return -ENOMEM;

	}

		if (skb->sk)

			skb_set_owner_w(skb2, skb->sk);

		consume_skb(skb);

		skb = skb2;

	}



	rcu_read_lock_bh();

	if (!nh) {
@@ -2214,8 +2206,7 @@ static int bpf_out_neigh_v6(struct net *net, struct sk_buff *skb, 
	}

	rcu_read_unlock_bh();

	if (dst)

		IP6_INC_STATS(dev_net(dst->dev),

			      ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);

		IP6_INC_STATS(net, ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES);

out_drop:

	kfree_skb(skb);

	return -ENETDOWN;
@@ -2287,18 +2278,10 @@ static int bpf_out_neigh_v4(struct net *net, struct sk_buff *skb, 
	skb->tstamp = 0;



	if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {

		struct sk_buff *skb2;



		skb2 = skb_realloc_headroom(skb, hh_len);

		if (unlikely(!skb2)) {

			kfree_skb(skb);

		skb = skb_expand_head(skb, hh_len);

		if (!skb)

			return -ENOMEM;

	}

		if (skb->sk)

			skb_set_owner_w(skb2, skb->sk);

		consume_skb(skb);

		skb = skb2;

	}



	rcu_read_lock_bh();

	if (!nh) {