From 65c88466602c61b639f75623e5ba72c1534df9bd Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Mon, 15 Oct 2007 01:29:10 -0700 Subject: [PATCH] [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 Signed-off-by: David S. Miller --- net/ipv6/exthdrs.c | 23 +++++------------------ 1 file changed, 5 insertions(+), 18 deletions(-) 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 @@ static int ipv6_dest_hao(struct sk_buff **skbp, int optoff) 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 @@ looped_back: 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) -- 2.7.4