This is a note to let you know that I've just added the patch titled
net IPv6 : Fix broken IPv6 routing table after loopback down-up
to the 3.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-ipv6-fix-broken-ipv6-routing-table-after-loopback-down-up.patch
and it can be found in the queue-3.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 3ec2ad707e8ed4ca45ff5d4f7b1e723b194dd866 Mon Sep 17 00:00:00 2001
From: Balakumaran Kannan <kumaran.4353@xxxxxxxxx>
Date: Tue, 2 Apr 2013 16:15:05 +0530
Subject: net IPv6 : Fix broken IPv6 routing table after loopback down-up
From: Balakumaran Kannan <kumaran.4353@xxxxxxxxx>
[ Upstream commit 25fb6ca4ed9cad72f14f61629b68dc03c0d9713f ]
IPv6 Routing table becomes broken once we do ifdown, ifup of the loopback(lo)
interface. After down-up, routes of other interface's IPv6 addresses through
'lo' are lost.
IPv6 addresses assigned to all interfaces are routed through 'lo' for internal
communication. Once 'lo' is down, those routing entries are removed from routing
table. But those removed entries are not being re-created properly when 'lo' is
brought up. So IPv6 addresses of other interfaces becomes unreachable from the
same machine. Also this breaks communication with other machines because of
NDISC packet processing failure.
This patch fixes this issue by reading all interface's IPv6 addresses and adding
them to IPv6 routing table while bringing up 'lo'.
==Testing==
Before applying the patch:
$ route -A inet6
Kernel IPv6 routing table
Destination Next Hop Flag Met Ref Use If
2000::20/128 :: U 256 0 0 eth0
fe80::/64 :: U 256 0 0 eth0
::/0 :: !n -1 1 1 lo
::1/128 :: Un 0 1 0 lo
2000::20/128 :: Un 0 1 0 lo
fe80::xxxx:xxxx:xxxx:xxxx/128 :: Un 0 1 0 lo
ff00::/8 :: U 256 0 0 eth0
::/0 :: !n -1 1 1 lo
$ sudo ifdown lo
$ sudo ifup lo
$ route -A inet6
Kernel IPv6 routing table
Destination Next Hop Flag Met Ref Use If
2000::20/128 :: U 256 0 0 eth0
fe80::/64 :: U 256 0 0 eth0
::/0 :: !n -1 1 1 lo
::1/128 :: Un 0 1 0 lo
ff00::/8 :: U 256 0 0 eth0
::/0 :: !n -1 1 1 lo
$
After applying the patch:
$ route -A inet6
Kernel IPv6 routing
table
Destination Next Hop Flag Met Ref Use If
2000::20/128 :: U 256 0 0 eth0
fe80::/64 :: U 256 0 0 eth0
::/0 :: !n -1 1 1 lo
::1/128 :: Un 0 1 0 lo
2000::20/128 :: Un 0 1 0 lo
fe80::xxxx:xxxx:xxxx:xxxx/128 :: Un 0 1 0 lo
ff00::/8 :: U 256 0 0 eth0
::/0 :: !n -1 1 1 lo
$ sudo ifdown lo
$ sudo ifup lo
$ route -A inet6
Kernel IPv6 routing table
Destination Next Hop Flag Met Ref Use If
2000::20/128 :: U 256 0 0 eth0
fe80::/64 :: U 256 0 0 eth0
::/0 :: !n -1 1 1 lo
::1/128 :: Un 0 1 0 lo
2000::20/128 :: Un 0 1 0 lo
fe80::xxxx:xxxx:xxxx:xxxx/128 :: Un 0 1 0 lo
ff00::/8 :: U 256 0 0 eth0
::/0 :: !n -1 1 1 lo
$
Signed-off-by: Balakumaran Kannan <Balakumaran.Kannan@xxxxxxxxxxx>
Signed-off-by: Maruthi Thotad <Maruthi.Thotad@xxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ipv6/addrconf.c | 27 +++++++++++++++++++++++++++
1 file changed, 27 insertions(+)
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -2399,6 +2399,9 @@ static void sit_add_v4_addrs(struct inet
static void init_loopback(struct net_device *dev)
{
struct inet6_dev *idev;
+ struct net_device *sp_dev;
+ struct inet6_ifaddr *sp_ifa;
+ struct rt6_info *sp_rt;
/* ::1 */
@@ -2410,6 +2413,30 @@ static void init_loopback(struct net_dev
}
add_addr(idev, &in6addr_loopback, 128, IFA_HOST);
+
+ /* Add routes to other interface's IPv6 addresses */
+ for_each_netdev(dev_net(dev), sp_dev) {
+ if (!strcmp(sp_dev->name, dev->name))
+ continue;
+
+ idev = __in6_dev_get(sp_dev);
+ if (!idev)
+ continue;
+
+ read_lock_bh(&idev->lock);
+ list_for_each_entry(sp_ifa, &idev->addr_list, if_list) {
+
+ if (sp_ifa->flags & (IFA_F_DADFAILED | IFA_F_TENTATIVE))
+ continue;
+
+ sp_rt = addrconf_dst_alloc(idev, &sp_ifa->addr, 0);
+
+ /* Failure cases are ignored */
+ if (!IS_ERR(sp_rt))
+ ip6_ins_rt(sp_rt);
+ }
+ read_unlock_bh(&idev->lock);
+ }
}
static void addrconf_add_linklocal(struct inet6_dev *idev, const struct in6_addr *addr)
Patches currently in stable-queue which might be from kumaran.4353@xxxxxxxxx are
queue-3.4/net-ipv6-fix-broken-ipv6-routing-table-after-loopback-down-up.patch
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