ipv6: Check expire on DST_NOCACHE route

Since the expires of the DST_NOCACHE rt can be set during
the ip6_rt_update_pmtu(), we also need to consider the expires
value when doing ip6_dst_check().

This patches creates __rt6_check_expired() to only
check the expire value (if one exists) of the current rt.

In rt6_dst_from_check(), it adds __rt6_check_expired() as
one of the condition check.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 1 deletions

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 74907c58a5c7..3754cf9287a0 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -404,6 +404,14 @@ static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
         }
 }
 
+static bool __rt6_check_expired(const struct rt6_info *rt)
+{
+        if (rt->rt6i_flags & RTF_EXPIRES)
+                return time_after(jiffies, rt->dst.expires);
+        else
+                return false;
+}
+
 static bool rt6_check_expired(const struct rt6_info *rt)
 {
         if (rt->rt6i_flags & RTF_EXPIRES) {
@@ -1252,7 +1260,8 @@ static struct dst_entry *rt6_check(struct rt6_info *rt, u32 cookie)
 
 static struct dst_entry *rt6_dst_from_check(struct rt6_info *rt, u32 cookie)
 {
-        if (rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
+        if (!__rt6_check_expired(rt) &&
+            rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
             rt6_check((struct rt6_info *)(rt->dst.from), cookie))
                 return &rt->dst;
         else