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 <kafai@fb.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 9e4c3c5..94ce1e0 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -105,6 +105,67 @@
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 @@
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 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 @@
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 @@
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 @@
int __init ip6_route_init(void)
{
int ret;
+ int cpu;
ret = -ENOMEM;
ip6_dst_ops_template.kmem_cachep =
@@ -3322,6 +3389,13 @@
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;