From: Julian Anastasov Date: Mon, 8 Aug 2011 05:20:20 +0000 (-0700) Subject: ipv4: fix the reusing of routing cache entries X-Git-Tag: v3.0.2~46 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=44a41f45fb2609b37ff81dcbce186dc3f7f95fcb;p=karo-tx-linux.git ipv4: fix the reusing of routing cache entries [ Upstream commit d547f727df86059104af2234804fdd538e112015 ] 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 Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 36fe0540b1ce..7890ae20e865 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -726,6 +726,7 @@ 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; } @@ -2282,8 +2283,8 @@ 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)) {