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 --- net/ipv4/fib_semantics.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'net/ipv4/fib_semantics.c') diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index 415f8230fc88..c46c20b6b0b6 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -163,6 +163,12 @@ void free_fib_info(struct fib_info *fi) return; } fib_info_cnt--; +#ifdef CONFIG_IP_ROUTE_CLASSID + change_nexthops(fi) { + if (nexthop_nh->nh_tclassid) + fib_num_tclassid_users--; + } endfor_nexthops(fi); +#endif call_rcu(&fi->rcu, free_fib_info_rcu); } @@ -421,6 +427,8 @@ static int fib_get_nhs(struct fib_info *fi, struct rtnexthop *rtnh, #ifdef CONFIG_IP_ROUTE_CLASSID nla = nla_find(attrs, attrlen, RTA_FLOW); nexthop_nh->nh_tclassid = nla ? nla_get_u32(nla) : 0; + if (nexthop_nh->nh_tclassid) + fib_num_tclassid_users++; #endif } @@ -815,6 +823,8 @@ struct fib_info *fib_create_info(struct fib_config *cfg) nh->nh_flags = cfg->fc_flags; #ifdef CONFIG_IP_ROUTE_CLASSID nh->nh_tclassid = cfg->fc_flow; + if (nh->nh_tclassid) + fib_num_tclassid_users++; #endif #ifdef CONFIG_IP_ROUTE_MULTIPATH nh->nh_weight = 1; -- cgit v1.2.3