[patch 13/19] [IPV6]: Fix route lifetime.

Greg Kroah-Hartman
2005-12-23T22:49:18Z

[-- Attachment #1: ipv6-fix-route-lifetime.patch --]
[-- Type: text/plain, Size: 2475 bytes --]

-stable review patch. If anyone has any objections, please let us know.

------------------
From: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

The route expiration time is stored in rt6i_expires in jiffies.
The argument of rt6_route_add() for adding a route is not the
expiration time in jiffies nor in clock_t, but the lifetime
(or time left before expiration) in clock_t.

Because of the confusion, we sometimes saw several strange errors
(FAILs) in TAHI IPv6 Ready Logo Phase-2 Self Test.
The symptoms were analyzed by Mitsuru Chinen <CHINEN@jp.ibm.com>.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Chris Wright <chrisw@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
net/ipv6/addrconf.c | 16 ++++++++++++----
net/ipv6/route.c | 2 +-
2 files changed, 13 insertions(+), 5 deletions(-)

--- linux-2.6.14.4.orig/net/ipv6/addrconf.c
+++ linux-2.6.14.4/net/ipv6/addrconf.c
@@ -1456,9 +1456,17 @@ void addrconf_prefix_rcv(struct net_devi
not good.
*/
if (valid_lft >= 0x7FFFFFFF/HZ)
- rt_expires = 0;
+ rt_expires = 0x7FFFFFFF - (0x7FFFFFFF % HZ);
else
- rt_expires = jiffies + valid_lft * HZ;
+ rt_expires = valid_lft * HZ;
+
+ /*
+ * We convert this (in jiffies) to clock_t later.
+ * Avoid arithmetic overflow there as well.
+ * Overflow can happen only if HZ < USER_HZ.
+ */
+ if (HZ < USER_HZ && rt_expires > 0x7FFFFFFF / USER_HZ)
+ rt_expires = 0x7FFFFFFF / USER_HZ;

if (pinfo->onlink) {
struct rt6_info *rt;
@@ -1470,12 +1478,12 @@ void addrconf_prefix_rcv(struct net_devi
ip6_del_rt(rt, NULL, NULL, NULL);
rt = NULL;
} else {
- rt->rt6i_expires = rt_expires;
+ rt->rt6i_expires = jiffies + rt_expires;
}
}
} else if (valid_lft) {
addrconf_prefix_route(&pinfo->prefix, pinfo->prefix_len,
- dev, rt_expires, RTF_ADDRCONF|RTF_EXPIRES|RTF_PREFIX_RT);
+ dev, jiffies_to_clock_t(rt_expires), RTF_ADDRCONF|RTF_EXPIRES|RTF_PREFIX_RT);
}
if (rt)
dst_release(&rt->u.dst);
--- linux-2.6.14.4.orig/net/ipv6/route.c
+++ linux-2.6.14.4/net/ipv6/route.c
@@ -829,7 +829,7 @@ int ip6_route_add(struct in6_rtmsg *rtms
}

rt->u.dst.obsolete = -1;
- rt->rt6i_expires = clock_t_to_jiffies(rtmsg->rtmsg_info);
+ rt->rt6i_expires = jiffies + clock_t_to_jiffies(rtmsg->rtmsg_info);
if (nlh && (r = NLMSG_DATA(nlh))) {
rt->rt6i_protocol = r->rtm_protocol;
} else {

--