From: Li Wei <lw@cn•fujitsu.com>
To: David Miller <davem@davemloft•net>
Cc: netdev@vger•kernel.org, shemminger@vyatta•com
Subject: [PATCH V2 resend] ipv6: fix incorrect route 'expires' value passed to userspace
Date: Fri, 20 Jul 2012 09:42:44 +0800 [thread overview]
Message-ID: <5008B794.7010904@cn.fujitsu.com> (raw)
In-Reply-To: <20120719.104906.38765587582698093.davem@davemloft.net>
When userspace use RTM_GETROUTE to dump route table, with an already
expired route entry, we always got an 'expires' value(2147157)
calculated base on INT_MAX.
The reason of this problem is in the following satement:
rt->dst.expires - jiffies < INT_MAX
gcc promoted the type of both sides of '<' to unsigned long, thus
a small negative value would be considered greater than INT_MAX.
This patch fix this by use the same trick as time_after macro to
avoid the 'unsigned long' type promotion and deal with jiffies
wrapping.
Also we should do some fix in rtnl_put_cacheinfo() which use
jiffies_to_clock_t(which take an unsigned long as parameter) to
convert jiffies to clock_t to handle the negative expires.
Signed-off-by: Li Wei <lw@cn•fujitsu.com>
---
net/core/rtnetlink.c | 3 ++-
net/ipv6/route.c | 7 ++++---
2 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 21318d1..f92f3d8 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -641,7 +641,8 @@ int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst, u32 id,
};
if (expires)
- ci.rta_expires = jiffies_to_clock_t(expires);
+ ci.rta_expires = expires > 0 ? jiffies_to_clock_t(expires)
+ : -jiffies_to_clock_t(-expires);
return nla_put(skb, RTA_CACHEINFO, sizeof(ci), &ci);
}
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index becb048..7875255 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -2516,10 +2516,11 @@ static int rt6_fill_node(struct net *net,
goto nla_put_failure;
if (!(rt->rt6i_flags & RTF_EXPIRES))
expires = 0;
- else if (rt->dst.expires - jiffies < INT_MAX)
- expires = rt->dst.expires - jiffies;
+ else if ((long)rt->dst.expires - (long)jiffies > INT_MIN
+ && (long)rt->dst.expires - (long)jiffies < INT_MAX)
+ expires = (long)rt->dst.expires - (long)jiffies;
else
- expires = INT_MAX;
+ expires = time_is_after_jiffies(rt->dst.expires) ? INT_MAX : INT_MIN;
peer = rt->rt6i_peer;
ts = tsage = 0;
--
1.7.1
next prev parent reply other threads:[~2012-07-20 1:43 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-16 8:09 [PATCH] ipv6: fix incorrect route 'expires' value passed to userspace Li Wei
2012-07-16 9:56 ` David Miller
2012-07-17 1:55 ` Li Wei
2012-07-19 2:02 ` [PATCH V2] " Li Wei
2012-07-19 17:49 ` David Miller
2012-07-20 1:32 ` Li Wei
2012-07-20 1:42 ` Li Wei [this message]
2012-07-20 10:32 ` [PATCH V2 resend] " David Laight
2012-07-20 18:22 ` David Miller
2012-07-23 1:05 ` Li Wei
2012-07-25 5:25 ` [PATCH V3] " Li Wei
2012-07-25 6:51 ` Eric Dumazet
2012-07-25 7:33 ` Li Wei
2012-07-30 2:01 ` [PATCH v4] " Li Wei
2012-07-30 6:20 ` David Miller
2012-07-23 1:02 ` [PATCH V2 resend] " Li Wei
2012-07-16 16:41 ` [PATCH] " Stephen Hemminger
2012-07-17 1:53 ` Li Wei
2012-07-17 5:26 ` David Miller
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