Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754648Ab3EJOnR (ORCPT ); Fri, 10 May 2013 10:43:17 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:57054 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754590Ab3EJOUp (ORCPT ); Fri, 10 May 2013 10:20:45 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Maruthi Thotad" , "Balakumaran Kannan" , "David S. Miller" , "Balakumaran Kannan" Date: Fri, 10 May 2013 14:39:41 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [086/118] net IPv6 : Fix broken IPv6 routing table after loopback down-up In-Reply-To: X-SA-Exim-Connect-IP: 2001:470:1f08:1539:d51a:8785:aa0a:cebe X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5581 Lines: 133 3.2.45-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Balakumaran Kannan [ 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 Signed-off-by: Maruthi Thotad Signed-off-by: David S. Miller Signed-off-by: Ben Hutchings --- net/ipv6/addrconf.c | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -2404,6 +2404,9 @@ 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 */ @@ -2415,6 +2418,30 @@ 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) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/