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: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Vasily Averin 2021-08-02 11:52:54 +03:00 committed by David S. Miller
parent 53744a4a72
commit a1e975e117
1 changed files with 5 additions and 22 deletions

View File

@ -2180,17 +2180,9 @@ 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();
@ -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;
@ -2287,17 +2278,9 @@ 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();