From 8d0b94afdca84598912347e61defa846a0988d04 Mon Sep 17 00:00:00 2001 From: Martin KaFai Lau Date: Fri, 22 May 2015 20:56:04 -0700 Subject: [PATCH] ipv6: Keep track of DST_NOCACHE routes in case of iface down/unregister This patch keeps track of the DST_NOCACHE routes in a list and replaces its dev with loopback during the iface down/unregister event. Signed-off-by: Martin KaFai Lau Cc: Hannes Frederic Sowa Cc: Steffen Klassert Cc: Julian Anastasov Signed-off-by: David S. Miller --- include/net/ip6_fib.h | 3 ++ net/ipv6/route.c | 78 +++++++++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 79 insertions(+), 2 deletions(-) diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h index 5556111022eb..cc8f03c10c43 100644 --- a/include/net/ip6_fib.h +++ b/include/net/ip6_fib.h @@ -120,6 +120,9 @@ struct rt6_info { struct rt6key rt6i_src; struct rt6key rt6i_prefsrc; + struct list_head rt6i_uncached; + struct uncached_list *rt6i_uncached_list; + struct inet6_dev *rt6i_idev; u32 rt6i_metric; diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 9e4c3c5d1591..94ce1e0b5a33 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -105,6 +105,67 @@ static struct rt6_info *rt6_get_route_info(struct net *net, const struct in6_addr *gwaddr, int ifindex); #endif +struct uncached_list { + spinlock_t lock; + struct list_head head; +}; + +static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt6_uncached_list); + +static void rt6_uncached_list_add(struct rt6_info *rt) +{ + struct uncached_list *ul = raw_cpu_ptr(&rt6_uncached_list); + + rt->dst.flags |= DST_NOCACHE; + rt->rt6i_uncached_list = ul; + + spin_lock_bh(&ul->lock); + list_add_tail(&rt->rt6i_uncached, &ul->head); + spin_unlock_bh(&ul->lock); +} + +static void rt6_uncached_list_del(struct rt6_info *rt) +{ + if (!list_empty(&rt->rt6i_uncached)) { + struct uncached_list *ul = rt->rt6i_uncached_list; + + spin_lock_bh(&ul->lock); + list_del(&rt->rt6i_uncached); + spin_unlock_bh(&ul->lock); + } +} + +static void rt6_uncached_list_flush_dev(struct net *net, struct net_device *dev) +{ + struct net_device *loopback_dev = net->loopback_dev; + int cpu; + + for_each_possible_cpu(cpu) { + struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu); + struct rt6_info *rt; + + spin_lock_bh(&ul->lock); + list_for_each_entry(rt, &ul->head, rt6i_uncached) { + struct inet6_dev *rt_idev = rt->rt6i_idev; + struct net_device *rt_dev = rt->dst.dev; + + if (rt_idev && (rt_idev->dev == dev || !dev) && + rt_idev->dev != loopback_dev) { + rt->rt6i_idev = in6_dev_get(loopback_dev); + in6_dev_put(rt_idev); + } + + if (rt_dev && (rt_dev == dev || !dev) && + rt_dev != loopback_dev) { + rt->dst.dev = loopback_dev; + dev_hold(rt->dst.dev); + dev_put(rt_dev); + } + } + spin_unlock_bh(&ul->lock); + } +} + static u32 *ipv6_cow_metrics(struct dst_entry *dst, unsigned long old) { struct rt6_info *rt = (struct rt6_info *)dst; @@ -262,6 +323,7 @@ static inline struct rt6_info *ip6_dst_alloc(struct net *net, memset(dst + 1, 0, sizeof(*rt) - sizeof(*dst)); INIT_LIST_HEAD(&rt->rt6i_siblings); + INIT_LIST_HEAD(&rt->rt6i_uncached); } return rt; } @@ -269,11 +331,14 @@ static inline struct rt6_info *ip6_dst_alloc(struct net *net, static void ip6_dst_destroy(struct dst_entry *dst) { struct rt6_info *rt = (struct rt6_info *)dst; - struct inet6_dev *idev = rt->rt6i_idev; struct dst_entry *from = dst->from; + struct inet6_dev *idev; dst_destroy_metrics_generic(dst); + rt6_uncached_list_del(rt); + + idev = rt->rt6i_idev; if (idev) { rt->rt6i_idev = NULL; in6_dev_put(idev); @@ -920,7 +985,7 @@ redo_rt6_select: dst_release(&rt->dst); if (uncached_rt) - uncached_rt->dst.flags |= DST_NOCACHE; + rt6_uncached_list_add(uncached_rt); else uncached_rt = net->ipv6.ip6_null_entry; dst_hold(&uncached_rt->dst); @@ -2367,6 +2432,7 @@ void rt6_ifdown(struct net *net, struct net_device *dev) fib6_clean_all(net, fib6_ifdown, &adn); icmp6_clean_all(fib6_ifdown, &adn); + rt6_uncached_list_flush_dev(net, dev); } struct rt6_mtu_change_arg { @@ -3263,6 +3329,7 @@ static struct notifier_block ip6_route_dev_notifier = { int __init ip6_route_init(void) { int ret; + int cpu; ret = -ENOMEM; ip6_dst_ops_template.kmem_cachep = @@ -3322,6 +3389,13 @@ int __init ip6_route_init(void) if (ret) goto out_register_late_subsys; + for_each_possible_cpu(cpu) { + struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu); + + INIT_LIST_HEAD(&ul->head); + spin_lock_init(&ul->lock); + } + out: return ret; -- 2.11.0