[PATCH] ipv4: Set rt->rt_iif more sanely on output routes.

[PATCH] ipv4: Set rt->rt_iif more sanely on output routes.

[David Miller]

rt->rt_iif is only ever inspected on input routes, for example DCCP
uses this to populate a route lookup flow key when generating replies
to another packet.

Therefore, setting it to anything other than zero on output routes
makes no sense.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/ipv4/route.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 9794a2c..602473c 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -2381,7 +2381,7 @@ static struct rtable *__mkroute_output(const struct fib_result *res,
 	rth->fl.mark    = oldflp->mark;
 	rth->rt_dst	= fl->fl4_dst;
 	rth->rt_src	= fl->fl4_src;
-	rth->rt_iif	= oldflp->oif ? : dev_out->ifindex;
+	rth->rt_iif	= 0;
 	/* get references to the devices that are to be hold by the routing
 	   cache entry */
 	rth->dst.dev	= dev_out;
-- 
1.7.4.1

Re: [PATCH] ipv4: Set rt->rt_iif more sanely on output routes.

[Eric Dumazet]

Le vendredi 04 mars 2011 à 21:36 -0800, David Miller a écrit :
> rt->rt_iif is only ever inspected on input routes, for example DCCP
> uses this to populate a route lookup flow key when generating replies
> to another packet.
> 
> Therefore, setting it to anything other than zero on output routes
> makes no sense.
> 
> Signed-off-by: David S. Miller <davem@davemloft.net>
> ---
>  net/ipv4/route.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
> 
> diff --git a/net/ipv4/route.c b/net/ipv4/route.c
> index 9794a2c..602473c 100644
> --- a/net/ipv4/route.c
> +++ b/net/ipv4/route.c
> @@ -2381,7 +2381,7 @@ static struct rtable *__mkroute_output(const struct fib_result *res,
>  	rth->fl.mark    = oldflp->mark;
>  	rth->rt_dst	= fl->fl4_dst;
>  	rth->rt_src	= fl->fl4_src;
> -	rth->rt_iif	= oldflp->oif ? : dev_out->ifindex;
> +	rth->rt_iif	= 0;
>  	/* get references to the devices that are to be hold by the routing
>  	   cache entry */
>  	rth->dst.dev	= dev_out;

Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>