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 <davem@davemloft.net>
diff --git a/include/net/fib_rules.h b/include/net/fib_rules.h
index 075f1e3..e361f48 100644
--- a/include/net/fib_rules.h
+++ b/include/net/fib_rules.h
@@ -52,6 +52,7 @@
struct sk_buff *,
struct fib_rule_hdr *,
struct nlattr **);
+ void (*delete)(struct fib_rule *);
int (*compare)(struct fib_rule *,
struct fib_rule_hdr *,
struct nlattr **);
