2 files changed, 29 insertions, 0 deletions

diff --git a/include/linux/if_vlan.h b/include/linux/if_vlan.h
index cfb0cf2230a9..69391cc20f3d 100644
--- a/include/linux/if_vlan.h
+++ b/include/linux/if_vlan.h
@@ -120,6 +120,8 @@ static inline int is_vlan_dev(struct net_device *dev)
 
 #if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
 
+extern struct net_device *__vlan_find_dev_deep(struct net_device *real_dev,
+                                               u16 vlan_id);
 extern struct net_device *vlan_dev_real_dev(const struct net_device *dev);
 extern u16 vlan_dev_vlan_id(const struct net_device *dev);
 
@@ -135,6 +137,12 @@ vlan_gro_frags(struct napi_struct *napi, struct vlan_group *grp,
                unsigned int vlan_tci);
 
 #else
+static inline struct net_device *
+__vlan_find_dev_deep(struct net_device *real_dev, u16 vlan_id)
+{
+        return NULL;
+}
+
 static inline struct net_device *vlan_dev_real_dev(const struct net_device *dev)
 {
         BUG();
diff --git a/net/8021q/vlan_core.c b/net/8021q/vlan_core.c
index fcc684678af6..5940366fac48 100644
--- a/net/8021q/vlan_core.c
+++ b/net/8021q/vlan_core.c
@@ -63,6 +63,27 @@ bool vlan_do_receive(struct sk_buff **skbp)
         return true;
 }
 
+/* Must be invoked with rcu_read_lock or with RTNL. */
+struct net_device *__vlan_find_dev_deep(struct net_device *real_dev,
+                                        u16 vlan_id)
+{
+        struct vlan_group *grp = rcu_dereference_rtnl(real_dev->vlgrp);
+
+        if (grp) {
+                return vlan_group_get_device(grp, vlan_id);
+        } else {
+                /*
+                 * Bonding slaves do not have grp assigned to themselves.
+                 * Grp is assigned to bonding master instead.
+                 */
+                if (netif_is_bond_slave(real_dev))
+                        return __vlan_find_dev_deep(real_dev->master, vlan_id);
+        }
+
+        return NULL;
+}
+EXPORT_SYMBOL(__vlan_find_dev_deep);
+
 struct net_device *vlan_dev_real_dev(const struct net_device *dev)
 {
         return vlan_dev_info(dev)->real_dev;