From 84e8b803f1e16f3a2b8b80f80a63fa2f2f8a9be6 Mon Sep 17 00:00:00 2001 From: stephen hemminger Date: Tue, 2 Mar 2010 13:32:46 +0000 Subject: [PATCH] IPv6: addrconf notify when address is unavailable My recent change in net-next to retain permanent addresses caused regression. Device refcount would not go to zero when device was unregistered because left over anycast reference would hold ipv6 dev reference which would hold device references... The correct procedure is to call notify chain when address is no longer available for use. When interface comes back DAD timer will notify back that address is available. Also, link local addresses should be purged when interface is brought down. The address might be changed. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- net/ipv6/addrconf.c | 46 ++++++++++++++++++++++++++++----------------- 1 file changed, 29 insertions(+), 17 deletions(-) diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 5f582f385abb..7a4bf7671285 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -2649,11 +2649,11 @@ static int addrconf_ifdown(struct net_device *dev, int how) write_lock_bh(&addrconf_hash_lock); while ((ifa = *bifa) != NULL) { if (ifa->idev == idev && - (how || !(ifa->flags&IFA_F_PERMANENT))) { + (how || !(ifa->flags&IFA_F_PERMANENT) || + ipv6_addr_type(&ifa->addr) & IPV6_ADDR_LINKLOCAL)) { *bifa = ifa->lst_next; ifa->lst_next = NULL; - addrconf_del_timer(ifa); - in6_ifa_put(ifa); + __in6_ifa_put(ifa); continue; } bifa = &ifa->lst_next; @@ -2691,28 +2691,40 @@ static int addrconf_ifdown(struct net_device *dev, int how) #endif bifa = &idev->addr_list; while ((ifa = *bifa) != NULL) { - if (how == 0 && (ifa->flags&IFA_F_PERMANENT)) { - /* Retain permanent address on admin down */ + addrconf_del_timer(ifa); + + /* If just doing link down, and address is permanent + and not link-local, then retain it. */ + if (how == 0 && + (ifa->flags&IFA_F_PERMANENT) && + !(ipv6_addr_type(&ifa->addr) & IPV6_ADDR_LINKLOCAL)) { bifa = &ifa->if_next; - /* Restart DAD if needed when link comes back up */ - if ( !((dev->flags&(IFF_NOARP|IFF_LOOPBACK)) || - idev->cnf.accept_dad <= 0 || - (ifa->flags & IFA_F_NODAD))) - ifa->flags |= IFA_F_TENTATIVE; + /* If not doing DAD on this address, just keep it. */ + if ((dev->flags&(IFF_NOARP|IFF_LOOPBACK)) || + idev->cnf.accept_dad <= 0 || + (ifa->flags & IFA_F_NODAD)) + continue; + + /* If it was tentative already, no need to notify */ + if (ifa->flags & IFA_F_TENTATIVE) + continue; + + /* Flag it for later restoration when link comes up */ + ifa->flags |= IFA_F_TENTATIVE; + in6_ifa_hold(ifa); } else { *bifa = ifa->if_next; ifa->if_next = NULL; - ifa->dead = 1; - write_unlock_bh(&idev->lock); + } + write_unlock_bh(&idev->lock); - __ipv6_ifa_notify(RTM_DELADDR, ifa); - atomic_notifier_call_chain(&inet6addr_chain, NETDEV_DOWN, ifa); - in6_ifa_put(ifa); + __ipv6_ifa_notify(RTM_DELADDR, ifa); + atomic_notifier_call_chain(&inet6addr_chain, NETDEV_DOWN, ifa); + in6_ifa_put(ifa); - write_lock_bh(&idev->lock); - } + write_lock_bh(&idev->lock); } write_unlock_bh(&idev->lock); -- 2.20.1