commit 24f5b855e17df7e355eacd6c4a12cc4d6a6c9ff0
Author: Li RongQing <roy.qing.li@gmail.com>
Date:   Thu Dec 19 12:40:26 2013 +0800

    ipv6: always set the new created dst's from in ip6_rt_copy
    
    ip6_rt_copy only sets dst.from if ort has flag RTF_ADDRCONF and RTF_DEFAULT.
    but the prefix routes which did get installed by hand locally can have an
    expiration, and no any flag combination which can ensure a potential from
    does never expire, so we should always set the new created dst's from.
    
    This also fixes the new created dst is always expired since the ort, which
    is created by RA, maybe has RTF_EXPIRES and RTF_ADDRCONF, but no RTF_DEFAULT.
    
    Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
    CC: Gao feng <gaofeng@cn.fujitsu.com>
    Signed-off-by: Li RongQing <roy.qing.li@gmail.com>
    Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
    Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index a0a48ac..4b4944c 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -1905,9 +1905,7 @@ static struct rt6_info *ip6_rt_copy(struct rt6_info *ort,
 		else
 			rt->rt6i_gateway = *dest;
 		rt->rt6i_flags = ort->rt6i_flags;
-		if ((ort->rt6i_flags & (RTF_DEFAULT | RTF_ADDRCONF)) ==
-		    (RTF_DEFAULT | RTF_ADDRCONF))
-			rt6_set_from(rt, ort);
+		rt6_set_from(rt, ort);
 		rt->rt6i_metric = 0;
 
 #ifdef CONFIG_IPV6_SUBTREES