[178/244] ipv4: some rt_iif -> rt_route_iif conversions

From: Greg KH
Date: Wed Sep 28 2011 - 19:04:37 EST


3.0-stable review patch. If anyone has any objections, please let us know.

------------------


From: Julian Anastasov <ja@xxxxxx>

[ Upstream commit 97a804102021431fa6fa33c21c85df762b0f5cb9 ]

As rt_iif represents input device even for packets
coming from loopback with output route, it is not an unique
key specific to input routes. Now rt_route_iif has such role,
it was fl.iif in 2.6.38, so better to change the checks at
some places to save CPU cycles and to restore 2.6.38 semantics.

compare_keys:
- input routes: only rt_route_iif matters, rt_iif is same
- output routes: only rt_oif matters, rt_iif is not
used for matching in __ip_route_output_key
- now we are back to 2.6.38 state

ip_route_input_common:
- matching rt_route_iif implies input route
- compared to 2.6.38 we eliminated one rth->fl.oif check
because it was not needed even for 2.6.38

compare_hash_inputs:
Only the change here is not an optimization, it has
effect only for output routes. I assume I'm restoring
the original intention to ignore oif, it was using fl.iif
- now we are back to 2.6.38 state

Signed-off-by: Julian Anastasov <ja@xxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
net/ipv4/route.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)

--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -717,7 +717,7 @@ static inline bool compare_hash_inputs(c
{
return ((((__force u32)rt1->rt_key_dst ^ (__force u32)rt2->rt_key_dst) |
((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
- (rt1->rt_iif ^ rt2->rt_iif)) == 0);
+ (rt1->rt_route_iif ^ rt2->rt_route_iif)) == 0);
}

static inline int compare_keys(struct rtable *rt1, struct rtable *rt2)
@@ -727,8 +727,7 @@ static inline int compare_keys(struct rt
(rt1->rt_mark ^ rt2->rt_mark) |
(rt1->rt_key_tos ^ rt2->rt_key_tos) |
(rt1->rt_route_iif ^ rt2->rt_route_iif) |
- (rt1->rt_oif ^ rt2->rt_oif) |
- (rt1->rt_iif ^ rt2->rt_iif)) == 0;
+ (rt1->rt_oif ^ rt2->rt_oif)) == 0;
}

static inline int compare_netns(struct rtable *rt1, struct rtable *rt2)
@@ -2282,9 +2281,8 @@ int ip_route_input_common(struct sk_buff
rth = rcu_dereference(rth->dst.rt_next)) {
if ((((__force u32)rth->rt_key_dst ^ (__force u32)daddr) |
((__force u32)rth->rt_key_src ^ (__force u32)saddr) |
- (rth->rt_iif ^ iif) |
+ (rth->rt_route_iif ^ iif) |
(rth->rt_key_tos ^ tos)) == 0 &&
- rt_is_input_route(rth) &&
rth->rt_mark == skb->mark &&
net_eq(dev_net(rth->dst.dev), net) &&
!rt_is_expired(rth)) {


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