Subject: Re: ip_rt_bug: 10.0.0.52 -> 255.255.255.255, ?

From: "Justin P. Mattock" <[email-masked]>
Date: Sun, 14 Aug 2011 22:55:02 -0700

Oh.. guess I will wait for those to be put into the Mainline then. 
Thanks for the info!

>
> First, please contact [email-masked] for networking issues.
>
> Second, this is fixed already:
>
> commit d547f727df86059104af2234804fdd538e112015
> Author: Julian Anastasov<[email-masked]>
> Date:   Sun Aug 7 22:20:20 2011 -0700
>
>      ipv4: fix the reusing of routing cache entries
>
>      	compare_keys and ip_route_input_common rely on
>      rt_oif for distinguishing of input and output routes
>      with same keys values. But sometimes the input route has
>      also same hash chain (keyed by iif != 0) with the output
>      routes (keyed by orig_oif=0). Problem visible if running
>      with small number of rhash_entries.
>
>      	Fix them to use rt_route_iif instead. By this way
>      input route can not be returned to users that request
>      output route.
>
>      	The patch fixes the ip_rt_bug errors that were
>      reported in ip_local_out context, mostly for 255.255.255.255
>      destinations.
>
>      Signed-off-by: Julian Anastasov<[email-masked]>
>      Signed-off-by: David S. Miller<[email-masked]>
>
> diff --git a/net/ipv4/route.c b/net/ipv4/route.c
> index e3dec1c..cb7efe0 100644
> --- a/net/ipv4/route.c
> +++ b/net/ipv4/route.c
> @@ -731,6 +731,7 @@ static inline int compare_keys(struct rtable *rt1, struct rtable *rt2)
>   		((__force u32)rt1->rt_key_src ^ (__force u32)rt2->rt_key_src) |
>   		(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;
>   }
> @@ -2321,8 +2322,8 @@ int ip_route_input_common(struct sk_buff *skb, __be32 daddr, __be32 saddr,
>   		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_oif |
>   		     (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)) {
>
>
>