[XFRM]: Use output device disable_xfrm for forwarded packets

Currently the behaviour of disable_xfrm is inconsistent between
locally generated and forwarded packets. For locally generated
packets disable_xfrm disables the policy lookup if it is set on
the output device, for forwarded traffic however it looks at the
input device. This makes it impossible to disable xfrm on all
devices but a dummy device and use normal routing to direct
traffic to that device.

Always use the output device when checking disable_xfrm.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 9f3924c4905e213fcd2c9dcf23f011eadbb00e92..11c167118e87fa87ecfd7898a6190c06fd24d7a0 100644 (file)
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1780,7 +1780,7 @@ static inline int __mkroute_input(struct sk_buff *skb,
 #endif
        if (in_dev->cnf.no_policy)
                rth->u.dst.flags |= DST_NOPOLICY;
-       if (in_dev->cnf.no_xfrm)
+       if (out_dev->cnf.no_xfrm)
                rth->u.dst.flags |= DST_NOXFRM;
        rth->fl.fl4_dst = daddr;
        rth->rt_dst     = daddr;