| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <CAHPKR9KE4LT_AEzUZ8cuJwBeMEEu0Ppe+jjynFQk7+N-A4YUmQ@mail.gmail.com>
Date: Thu, 28 Mar 2013 18:57:15 +0530
From: Balakumaran Kannan <kumaran.4353@...il.com>
To: yoshfuji@...ux-ipv6.org, davem@...emloft.net,
Patrick McHardy <kaber@...sh.net>,
Alexey Kuznetsov <kuznet@....inr.ac.ru>, jmorris@...ei.org,
eric.dumazet@...il.com
Cc: Balakumaran.Kannan@...sony.com, maruthi.thotad@...sony.com,
netdev@...r.kernel.org, jamshed.a@...sony.com,
amit.agarwal@...sony.com, takuzo.ohara@...sony.com,
aaditya.kumar@...sony.com
Subject: [PATCH v2] net IPv6 : Fix broken IPv6 routing table after loopback down-up
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'.
Patch is prepared for Linux-3.9.rc4 kernel.
Signed-off-by: Balakumaran Kannan <Balakumaran.Kannan@...sony.com>
Signed-off-by: Maruthi Thotad <Maruthi.Thotad@...sm.sony.com>
---
This is version-2 of the patch sent earlier.
[Ref: http://marc.info/?l=linux-netdev&m=136437848103355&w=2]
Change Log:
1. Used 'for_each_netdev_rcu' instead of while loop.
2. Added required locks.
3. Skipping IPv6 addresses with 'IFA_F_DADFAILED' or 'IFA_F_TENTATIVE' flags
==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
$
---
--- linux-3.9-rc4/net/ipv6/addrconf.c.orig 2013-03-27 10:40:26.382569527 +0530
+++ linux-3.9-rc4/net/ipv6/addrconf.c 2013-03-28 18:29:00.492241840 +0530
@@ -2529,6 +2529,9 @@ 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 */
@@ -2540,6 +2543,33 @@ static void init_loopback(struct net_dev
}
add_addr(idev, &in6addr_loopback, 128, IFA_HOST);
+
+ /* Add routes to other interface's IPv6 addresses */
+ rcu_read_lock();
+ for_each_netdev_rcu(dev_net(dev), sp_dev) {
+
+ if (!strcmp(sp_dev->name, dev->name))
+ continue;
+
+ idev = ipv6_find_idev(sp_dev);
+ if (NULL == 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);
+ }
+ rcu_read_unlock();
}
static void addrconf_add_linklocal(struct inet6_dev *idev, const
struct in6_addr *addr)
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Powered by blists - more mailing lists