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_rules.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) (limited to 'net/ipv4/fib_rules.c') diff --git a/net/ipv4/fib_rules.c b/net/ipv4/fib_rules.c index 2d043f71ef7..b23fd952c84 100644 --- a/net/ipv4/fib_rules.c +++ b/net/ipv4/fib_rules.c @@ -169,8 +169,11 @@ static int fib4_rule_configure(struct fib_rule *rule, struct sk_buff *skb, rule4->dst = nla_get_be32(tb[FRA_DST]); #ifdef CONFIG_IP_ROUTE_CLASSID - if (tb[FRA_FLOW]) + if (tb[FRA_FLOW]) { rule4->tclassid = nla_get_u32(tb[FRA_FLOW]); + if (rule4->tclassid) + fib_num_tclassid_users++; + } #endif rule4->src_len = frh->src_len; @@ -184,6 +187,16 @@ errout: return err; } +static void fib4_rule_delete(struct fib_rule *rule) +{ +#ifdef CONFIG_IP_ROUTE_CLASSID + struct fib4_rule *rule4 = (struct fib4_rule *) rule; + + if (rule4->tclassid) + fib_num_tclassid_users--; +#endif +} + static int fib4_rule_compare(struct fib_rule *rule, struct fib_rule_hdr *frh, struct nlattr **tb) { @@ -256,6 +269,7 @@ static const struct fib_rules_ops __net_initdata fib4_rules_ops_template = { .action = fib4_rule_action, .match = fib4_rule_match, .configure = fib4_rule_configure, + .delete = fib4_rule_delete, .compare = fib4_rule_compare, .fill = fib4_rule_fill, .default_pref = fib_default_rule_pref, -- cgit v1.2.3-18-g5258