[IPV6]: Avoid skb_copy/pskb_copy/skb_realloc_headroom on input
This patch replaces unnecessary uses of skb_copy by pskb_expand_head
on the IPv6 input path.
This allows us to remove the double pointers later.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/exthdrs.c b/net/ipv6/exthdrs.c
index c82d4d4..0ff2bf1 100644
--- a/net/ipv6/exthdrs.c
+++ b/net/ipv6/exthdrs.c
@@ -234,22 +234,13 @@
goto discard;
if (skb_cloned(skb)) {
- struct sk_buff *skb2 = skb_copy(skb, GFP_ATOMIC);
- struct inet6_skb_parm *opt2;
-
- if (skb2 == NULL)
+ if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC))
goto discard;
- opt2 = IP6CB(skb2);
- memcpy(opt2, opt, sizeof(*opt2));
-
- kfree_skb(skb);
-
/* update all variable using below by copied skbuff */
- *skbp = skb = skb2;
- hao = (struct ipv6_destopt_hao *)(skb_network_header(skb2) +
+ hao = (struct ipv6_destopt_hao *)(skb_network_header(skb) +
optoff);
- ipv6h = ipv6_hdr(skb2);
+ ipv6h = ipv6_hdr(skb);
}
if (skb->ip_summed == CHECKSUM_COMPLETE)
@@ -464,18 +455,14 @@
Do not damage packets queued somewhere.
*/
if (skb_cloned(skb)) {
- struct sk_buff *skb2 = skb_copy(skb, GFP_ATOMIC);
/* the copy is a forwarded packet */
- if (skb2 == NULL) {
+ if (pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) {
IP6_INC_STATS_BH(ip6_dst_idev(skb->dst),
IPSTATS_MIB_OUTDISCARDS);
kfree_skb(skb);
return -1;
}
- kfree_skb(skb);
- *skbp = skb = skb2;
- opt = IP6CB(skb2);
- hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb2);
+ hdr = (struct ipv6_rt_hdr *)skb_transport_header(skb);
}
if (skb->ip_summed == CHECKSUM_COMPLETE)