[PATCH NET v3 4/7] ipv4: use skb_expand_head in ip_finish_output2

From: Vasily Averin
Date: Mon Aug 02 2021 - 04:52:46 EST


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

Signed-off-by: Vasily Averin <vvs@xxxxxxxxxxxxx>
---
net/ipv4/ip_output.c | 13 ++-----------
1 file changed, 2 insertions(+), 11 deletions(-)

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index 8d8a8da..c6b755e 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -198,19 +198,10 @@ static int ip_finish_output2(struct net *net, struct sock *sk, struct sk_buff *s
} else if (rt->rt_type == RTN_BROADCAST)
IP_UPD_PO_STATS(net, IPSTATS_MIB_OUTBCAST, skb->len);

- /* Be paranoid, rather than too clever. */
if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) {
- struct sk_buff *skb2;
-
- skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev));
- if (!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;
}

if (lwtunnel_xmit_redirect(dst->lwtstate)) {
--
1.8.3.1