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authorHerbert Xu <herbert@gondor.apana.org.au>2009-05-26 18:50:28 +0000
committerDavid S. Miller <davem@davemloft.net>2009-05-27 03:26:01 -0700
commita5b1cf288d4200506ab62fbb86cc81ace948a306 (patch)
treec95339866f4d67220d111811a92e5c6b79de6ab4 /net
parent7489594cb249aeb178287c9a43a9e4f366044259 (diff)
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gro: Avoid unnecessary comparison after skb_gro_header
For the overwhelming majority of cases, skb_gro_header's return value cannot be NULL. Yet we must check it because of its current form. This patch splits it up into multiple functions in order to avoid this. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/core/dev.c17
-rw-r--r--net/ipv4/af_inet.c13
-rw-r--r--net/ipv4/tcp.c22
-rw-r--r--net/ipv6/af_inet6.c13
4 files changed, 48 insertions, 17 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index b1722a2d1fb..cd29e613bc5 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2590,17 +2590,24 @@ struct sk_buff *napi_frags_skb(struct napi_struct *napi)
{
struct sk_buff *skb = napi->skb;
struct ethhdr *eth;
+ unsigned int hlen;
+ unsigned int off;
napi->skb = NULL;
skb_reset_mac_header(skb);
skb_gro_reset_offset(skb);
- eth = skb_gro_header(skb, sizeof(*eth));
- if (!eth) {
- napi_reuse_skb(napi, skb);
- skb = NULL;
- goto out;
+ off = skb_gro_offset(skb);
+ hlen = off + sizeof(*eth);
+ eth = skb_gro_header_fast(skb, off);
+ if (skb_gro_header_hard(skb, hlen)) {
+ eth = skb_gro_header_slow(skb, hlen, off);
+ if (unlikely(!eth)) {
+ napi_reuse_skb(napi, skb);
+ skb = NULL;
+ goto out;
+ }
}
skb_gro_pull(skb, sizeof(*eth));
diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c
index 170689681aa..644cc553531 100644
--- a/net/ipv4/af_inet.c
+++ b/net/ipv4/af_inet.c
@@ -1246,13 +1246,20 @@ static struct sk_buff **inet_gro_receive(struct sk_buff **head,
struct sk_buff **pp = NULL;
struct sk_buff *p;
struct iphdr *iph;
+ unsigned int hlen;
+ unsigned int off;
int flush = 1;
int proto;
int id;
- iph = skb_gro_header(skb, sizeof(*iph));
- if (unlikely(!iph))
- goto out;
+ off = skb_gro_offset(skb);
+ hlen = off + sizeof(*iph);
+ iph = skb_gro_header_fast(skb, off);
+ if (skb_gro_header_hard(skb, hlen)) {
+ iph = skb_gro_header_slow(skb, hlen, off);
+ if (unlikely(!iph))
+ goto out;
+ }
proto = iph->protocol & (MAX_INET_PROTOS - 1);
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 68342d43189..c3dcec5efea 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2518,20 +2518,30 @@ struct sk_buff **tcp_gro_receive(struct sk_buff **head, struct sk_buff *skb)
unsigned int thlen;
unsigned int flags;
unsigned int mss = 1;
+ unsigned int hlen;
+ unsigned int off;
int flush = 1;
int i;
- th = skb_gro_header(skb, sizeof(*th));
- if (unlikely(!th))
- goto out;
+ off = skb_gro_offset(skb);
+ hlen = off + sizeof(*th);
+ th = skb_gro_header_fast(skb, off);
+ if (skb_gro_header_hard(skb, hlen)) {
+ th = skb_gro_header_slow(skb, hlen, off);
+ if (unlikely(!th))
+ goto out;
+ }
thlen = th->doff * 4;
if (thlen < sizeof(*th))
goto out;
- th = skb_gro_header(skb, thlen);
- if (unlikely(!th))
- goto out;
+ hlen = off + thlen;
+ if (skb_gro_header_hard(skb, hlen)) {
+ th = skb_gro_header_slow(skb, hlen, off);
+ if (unlikely(!th))
+ goto out;
+ }
skb_gro_pull(skb, thlen);
diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c
index 61f55386a23..b6215be0963 100644
--- a/net/ipv6/af_inet6.c
+++ b/net/ipv6/af_inet6.c
@@ -817,13 +817,20 @@ static struct sk_buff **ipv6_gro_receive(struct sk_buff **head,
struct sk_buff *p;
struct ipv6hdr *iph;
unsigned int nlen;
+ unsigned int hlen;
+ unsigned int off;
int flush = 1;
int proto;
__wsum csum;
- iph = skb_gro_header(skb, sizeof(*iph));
- if (unlikely(!iph))
- goto out;
+ off = skb_gro_offset(skb);
+ hlen = off + sizeof(*iph);
+ iph = skb_gro_header_fast(skb, off);
+ if (skb_gro_header_hard(skb, hlen)) {
+ iph = skb_gro_header_slow(skb, hlen, off);
+ if (unlikely(!iph))
+ goto out;
+ }
skb_gro_pull(skb, sizeof(*iph));
skb_set_transport_header(skb, skb_gro_offset(skb));