From 7a9bc9b81a5bc6e44ebc80ef781332e4385083f2 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Fri, 29 Jun 2012 01:32:45 -0700 Subject: ipv4: Elide fib_validate_source() completely when possible. If rpfilter is off (or the SKB has an IPSEC path) and there are not tclassid users, we don't have to do anything at all when fib_validate_source() is invoked besides setting the itag to zero. We monitor tclassid uses with a counter (modified only under RTNL and marked __read_mostly) and we protect the fib_validate_source() real work with a test against this counter and whether rpfilter is to be done. Having a way to know whether we need no tclassid processing or not also opens the door for future optimized rpfilter algorithms that do not perform full FIB lookups. Signed-off-by: David S. Miller --- include/net/ip_fib.h | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'include/net/ip_fib.h') diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h index 619f68a7185c..3dc7c96bbeab 100644 --- a/include/net/ip_fib.h +++ b/include/net/ip_fib.h @@ -235,6 +235,11 @@ extern int fib_validate_source(struct sk_buff *skb, __be32 src, __be32 dst, u8 tos, int oif, struct net_device *dev, struct in_device *idev, u32 *itag); extern void fib_select_default(struct fib_result *res); +#ifdef CONFIG_IP_ROUTE_CLASSID +extern int fib_num_tclassid_users; +#else +#define fib_num_tclassid_users 0 +#endif /* Exported by fib_semantics.c */ extern int ip_fib_check_default(__be32 gw, struct net_device *dev); -- cgit v1.2.2