From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sergey Popovich Subject: [PATCH 4/4 v3] ipv4: mark nexthop as dead when it's subnet becomes unreachable Date: Fri, 24 Jan 2014 12:25:17 +0200 Message-ID: <1521507.ObZglEaf1D@tuxracer> References: <2039386.VZO3kUlZdW@tuxracer> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit To: netdev@vger.kernel.org Return-path: Received: from smtp40.i.mail.ru ([94.100.177.100]:51490 "EHLO smtp40.i.mail.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752018AbaAXKZW (ORCPT ); Fri, 24 Jan 2014 05:25:22 -0500 Received: from [2a01:6d80:103:13::c3ea:4404] (port=57159 helo=tuxracer.localnet) by smtp40.i.mail.ru with esmtpa (envelope-from ) id 1W6dwt-00086L-Kj for netdev@vger.kernel.org; Fri, 24 Jan 2014 14:25:20 +0400 In-Reply-To: <2039386.VZO3kUlZdW@tuxracer> Sender: netdev-owner@vger.kernel.org List-ID: Removing ip address and it's subnet route using fib_del_ifaddr() does not purge routes with nexthop in such subnet. This could be easily reproduced with the following config: ip link add dev dummy1 type dummy ip link set up dev dummy1 ip -4 addr add 10.0.10.1/24 dev dummy1 ip -4 addr add 10.0.20.1/24 dev dummy1 ip -4 route add 172.16.0.0/12 proto static via 10.0.10.5 ip -4 route show exact 172.16.0.0/12 172.16.0.0/12 via 10.0.10.5 dev dummy1 proto static ip -4 addr del 10.0.10.1/24 dev dummy1 ip -4 route show exact 172.16.0.0/12 172.16.0.0/12 via 10.0.10.5 dev dummy1 proto static Add interface address (ifa) parameter to fib_sync_down_dev() and use it to match nexthop against it's subnet. Use fib_sync_down_dev() in fib_del_ifaddr() among with fib_sync_down_addr() to mark as dead routes with nexthop in ifa. v3. Fix NH marking as dead when NH gateway subnet is still on interface (e.g. 10.0.10.1/24 and 10.0.30.1/16 and NH is 10.0.10.5). Thanks to Julian Anastasov. v2. Fix NH marking as dead when NH created with onlink option. Signed-off-by: Sergey Popovich --- include/net/ip_fib.h | 3 ++- net/ipv4/fib_frontend.c | 5 +++-- net/ipv4/fib_semantics.c | 29 +++++++++++++++++++++++++++-- 3 files changed, 32 insertions(+), 5 deletions(-) diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h index 9922093..0405fc9 100644 --- a/include/net/ip_fib.h +++ b/include/net/ip_fib.h @@ -287,8 +287,9 @@ static inline int fib_num_tclassid_users(struct net *net) #endif /* Exported by fib_semantics.c */ +struct in_ifaddr; int ip_fib_check_default(__be32 gw, struct net_device *dev); -int fib_sync_down_dev(struct net_device *dev, int force); +int fib_sync_down_dev(struct net_device *dev, struct in_ifaddr *ifa, int force); int fib_sync_down_addr(struct net *net, __be32 local); int fib_sync_up(struct net_device *dev); void fib_select_multipath(struct fib_result *res); diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c index ae5f35f..fd3445e 100644 --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -907,7 +907,8 @@ void fib_del_ifaddr(struct in_ifaddr *ifa, struct in_ifaddr *iprim) * First of all, we scan fib_info list searching * for stray nexthop entries, then ignite fib_flush. */ - if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local)) + if (fib_sync_down_addr(dev_net(dev), ifa->ifa_local) + + fib_sync_down_dev(dev, ifa, 0)) fib_flush(dev_net(dev)); } } @@ -997,7 +998,7 @@ static void nl_fib_lookup_exit(struct net *net) static void fib_disable_ip(struct net_device *dev, int force) { - if (fib_sync_down_dev(dev, force)) + if (fib_sync_down_dev(dev, NULL, force)) fib_flush(dev_net(dev)); rt_cache_flush(dev_net(dev)); arp_ifdown(dev); diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index 9d43468..fbebba5 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -1112,7 +1112,29 @@ int fib_sync_down_addr(struct net *net, __be32 local) return ret; } -int fib_sync_down_dev(struct net_device *dev, int force) +static inline bool fib_sync_down_gw(struct fib_nh *nh, + struct in_ifaddr *ifr) +{ + if (!ifr) + return true; + + if (nh->nh_flags & RTNH_F_ONLINK) + return false; + + if (!inet_ifa_match(nh->nh_gw, ifr)) + return false; + + for_ifa(ifr->ifa_dev) { + if (unlikely(ifa == ifr)) + continue; + if (inet_ifa_match(nh->nh_gw, ifa)) + return false; + } endfor_ifa(ifr->ifa_dev); + + return true; +} + +int fib_sync_down_dev(struct net_device *dev, struct in_ifaddr *ifa, int force) { int ret = 0; int scope = RT_SCOPE_NOWHERE; @@ -1124,6 +1146,8 @@ int fib_sync_down_dev(struct net_device *dev, int force) if (force) scope = -1; + BUG_ON(ifa && ifa->ifa_dev->dev != dev); + hlist_for_each_entry(nh, head, nh_hash) { struct fib_info *fi = nh->nh_parent; int dead; @@ -1137,7 +1161,8 @@ int fib_sync_down_dev(struct net_device *dev, int force) if (nexthop_nh->nh_flags & RTNH_F_DEAD) dead++; else if (nexthop_nh->nh_dev == dev && - nexthop_nh->nh_scope != scope) { + nexthop_nh->nh_scope != scope && + fib_sync_down_gw(nexthop_nh, ifa)) { nexthop_nh->nh_flags |= RTNH_F_DEAD; #ifdef CONFIG_IP_ROUTE_MULTIPATH spin_lock_bh(&fib_multipath_lock); -- 1.8.3.4