[NETFILTER]: reduce netfilter sk_buff enlargement
As discussed at netconf'05, we're trying to save every bit in sk_buff.
The patch below makes sk_buff 8 bytes smaller. I did some basic
testing on my notebook and it seems to work.
The only real in-tree user of nfcache was IPVS, who only needs a
single bit. Unfortunately I couldn't find some other free bit in
sk_buff to stuff that bit into, so I introduced a separate field for
them. Maybe the IPVS guys can resolve that to further save space.
Initially I wanted to shrink pkt_type to three bits (PACKET_HOST and
alike are only 6 values defined), but unfortunately the bluetooth code
overloads pkt_type :(
The conntrack-event-api (out-of-tree) uses nfcache, but Rusty just
came up with a way how to do it without any skb fields, so it's safe
to remove it.
- remove all never-implemented 'nfcache' code
- don't have ipvs code abuse 'nfcache' field. currently get's their own
compile-conditional skb->ipvs_property field. IPVS maintainers can
decide to move this bit elswhere, but nfcache needs to die.
- remove skb->nfcache field to save 4 bytes
- move skb->nfctinfo into three unused bits to save further 4 bytes
Signed-off-by: Harald Welte <laforge@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index ae652ca..590d2b7 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -185,19 +185,6 @@
}
#endif
-static inline int ip6_maybe_reroute(struct sk_buff *skb)
-{
-#ifdef CONFIG_NETFILTER
- if (skb->nfcache & NFC_ALTERED){
- if (ip6_route_me_harder(skb) != 0){
- kfree_skb(skb);
- return -EINVAL;
- }
- }
-#endif /* CONFIG_NETFILTER */
- return dst_output(skb);
-}
-
/*
* xmit an sk_buff (used by TCP)
*/
@@ -266,7 +253,8 @@
mtu = dst_mtu(dst);
if ((skb->len <= mtu) || ipfragok) {
IP6_INC_STATS(IPSTATS_MIB_OUTREQUESTS);
- return NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev, ip6_maybe_reroute);
+ return NF_HOOK(PF_INET6, NF_IP6_LOCAL_OUT, skb, NULL, dst->dev,
+ dst_output);
}
if (net_ratelimit())