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Diffstat (limited to 'net')
-rw-r--r--net/ipv6/route.c29
-rw-r--r--net/l3mdev/l3mdev.c7
2 files changed, 30 insertions, 6 deletions
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 66fc69ef5909..3975ae8e2440 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -2415,8 +2415,9 @@ static struct rt6_info *ip6_pol_route_output(struct net *net,
return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, skb, flags);
}
-struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk,
- struct flowi6 *fl6, int flags)
+struct dst_entry *ip6_route_output_flags_noref(struct net *net,
+ const struct sock *sk,
+ struct flowi6 *fl6, int flags)
{
bool any_src;
@@ -2424,6 +2425,7 @@ struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk,
(IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL)) {
struct dst_entry *dst;
+ /* This function does not take refcnt on the dst */
dst = l3mdev_link_scope_lookup(net, fl6);
if (dst)
return dst;
@@ -2431,6 +2433,7 @@ struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk,
fl6->flowi6_iif = LOOPBACK_IFINDEX;
+ flags |= RT6_LOOKUP_F_DST_NOREF;
any_src = ipv6_addr_any(&fl6->saddr);
if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr) ||
(fl6->flowi6_oif && any_src))
@@ -2443,6 +2446,28 @@ struct dst_entry *ip6_route_output_flags(struct net *net, const struct sock *sk,
return fib6_rule_lookup(net, fl6, NULL, flags, ip6_pol_route_output);
}
+EXPORT_SYMBOL_GPL(ip6_route_output_flags_noref);
+
+struct dst_entry *ip6_route_output_flags(struct net *net,
+ const struct sock *sk,
+ struct flowi6 *fl6,
+ int flags)
+{
+ struct dst_entry *dst;
+ struct rt6_info *rt6;
+
+ rcu_read_lock();
+ dst = ip6_route_output_flags_noref(net, sk, fl6, flags);
+ rt6 = (struct rt6_info *)dst;
+ /* For dst cached in uncached_list, refcnt is already taken. */
+ if (list_empty(&rt6->rt6i_uncached) && !dst_hold_safe(dst)) {
+ dst = &net->ipv6.ip6_null_entry->dst;
+ dst_hold(dst);
+ }
+ rcu_read_unlock();
+
+ return dst;
+}
EXPORT_SYMBOL_GPL(ip6_route_output_flags);
struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig)
diff --git a/net/l3mdev/l3mdev.c b/net/l3mdev/l3mdev.c
index cfc9fcb97465..f35899d45a9a 100644
--- a/net/l3mdev/l3mdev.c
+++ b/net/l3mdev/l3mdev.c
@@ -118,6 +118,8 @@ EXPORT_SYMBOL_GPL(l3mdev_fib_table_by_index);
* local and multicast addresses
* @net: network namespace for device index lookup
* @fl6: IPv6 flow struct for lookup
+ * This function does not hold refcnt on the returned dst.
+ * Caller must hold rcu_read_lock().
*/
struct dst_entry *l3mdev_link_scope_lookup(struct net *net,
@@ -126,9 +128,8 @@ struct dst_entry *l3mdev_link_scope_lookup(struct net *net,
struct dst_entry *dst = NULL;
struct net_device *dev;
+ WARN_ON_ONCE(!rcu_read_lock_held());
if (fl6->flowi6_oif) {
- rcu_read_lock();
-
dev = dev_get_by_index_rcu(net, fl6->flowi6_oif);
if (dev && netif_is_l3_slave(dev))
dev = netdev_master_upper_dev_get_rcu(dev);
@@ -136,8 +137,6 @@ struct dst_entry *l3mdev_link_scope_lookup(struct net *net,
if (dev && netif_is_l3_master(dev) &&
dev->l3mdev_ops->l3mdev_link_scope_lookup)
dst = dev->l3mdev_ops->l3mdev_link_scope_lookup(dev, fl6);
-
- rcu_read_unlock();
}
return dst;