2 files changed, 64 insertions, 11 deletions

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 514045c704a8..75d5beac463b 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2839,8 +2839,15 @@ extern int netdev_upper_dev_link(struct net_device *dev,
                                  struct net_device *upper_dev);
 extern int netdev_master_upper_dev_link(struct net_device *dev,
                                         struct net_device *upper_dev);
+extern int netdev_master_upper_dev_link_private(struct net_device *dev,
+                                                struct net_device *upper_dev,
+                                                void *private);
 extern void netdev_upper_dev_unlink(struct net_device *dev,
                                     struct net_device *upper_dev);
+extern void *netdev_lower_dev_get_private_rcu(struct net_device *dev,
+                                              struct net_device *lower_dev);
+extern void *netdev_lower_dev_get_private(struct net_device *dev,
+                                          struct net_device *lower_dev);
 extern int skb_checksum_help(struct sk_buff *skb);
 extern struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
         netdev_features_t features, bool tx_path);
diff --git a/net/core/dev.c b/net/core/dev.c
index 9290f09cdf26..c69ab74fb201 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4376,6 +4376,9 @@ struct netdev_adjacent {
         /* counter for the number of times this device was added to us */
         u16 ref_nr;
 
+        /* private field for the users */
+        void *private;
+
         struct list_head list;
         struct rcu_head rcu;
 };
@@ -4510,7 +4513,7 @@ EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);
 static int __netdev_adjacent_dev_insert(struct net_device *dev,
                                         struct net_device *adj_dev,
                                         struct list_head *dev_list,
-                                        bool master)
+                                        void *private, bool master)
 {
         struct netdev_adjacent *adj;
 
@@ -4528,6 +4531,7 @@ static int __netdev_adjacent_dev_insert(struct net_device *dev,
         adj->dev = adj_dev;
         adj->master = master;
         adj->ref_nr = 1;
+        adj->private = private;
         dev_hold(adj_dev);
 
         pr_debug("dev_hold for %s, because of link added from %s to %s\n",
@@ -4574,15 +4578,17 @@ int __netdev_adjacent_dev_link_lists(struct net_device *dev,
                                      struct net_device *upper_dev,
                                      struct list_head *up_list,
                                      struct list_head *down_list,
-                                     bool master)
+                                     void *private, bool master)
 {
         int ret;
 
-        ret = __netdev_adjacent_dev_insert(dev, upper_dev, up_list, master);
+        ret = __netdev_adjacent_dev_insert(dev, upper_dev, up_list, private,
+                                           master);
         if (ret)
                 return ret;
 
-        ret = __netdev_adjacent_dev_insert(upper_dev, dev, down_list, false);
+        ret = __netdev_adjacent_dev_insert(upper_dev, dev, down_list, private,
+                                           false);
         if (ret) {
                 __netdev_adjacent_dev_remove(dev, upper_dev, up_list);
                 return ret;
@@ -4597,7 +4603,7 @@ int __netdev_adjacent_dev_link(struct net_device *dev,
         return __netdev_adjacent_dev_link_lists(dev, upper_dev,
                                                 &dev->all_adj_list.upper,
                                                 &upper_dev->all_adj_list.lower,
-                                                false);
+                                                NULL, false);
 }
 
 void __netdev_adjacent_dev_unlink_lists(struct net_device *dev,
@@ -4619,7 +4625,7 @@ void __netdev_adjacent_dev_unlink(struct net_device *dev,
 
 int __netdev_adjacent_dev_link_neighbour(struct net_device *dev,
                                          struct net_device *upper_dev,
-                                         bool master)
+                                         void *private, bool master)
 {
         int ret = __netdev_adjacent_dev_link(dev, upper_dev);
 
@@ -4629,7 +4635,7 @@ int __netdev_adjacent_dev_link_neighbour(struct net_device *dev,
         ret = __netdev_adjacent_dev_link_lists(dev, upper_dev,
                                                &dev->adj_list.upper,
                                                &upper_dev->adj_list.lower,
-                                               master);
+                                               private, master);
         if (ret) {
                 __netdev_adjacent_dev_unlink(dev, upper_dev);
                 return ret;
@@ -4648,7 +4654,8 @@ void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev,
 }
 
 static int __netdev_upper_dev_link(struct net_device *dev,
-                                   struct net_device *upper_dev, bool master)
+                                   struct net_device *upper_dev, bool master,
+                                   void *private)
 {
         struct netdev_adjacent *i, *j, *to_i, *to_j;
         int ret = 0;
@@ -4668,7 +4675,8 @@ static int __netdev_upper_dev_link(struct net_device *dev,
         if (master && netdev_master_upper_dev_get(dev))
                 return -EBUSY;
 
-        ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, master);
+        ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, private,
+                                                   master);
         if (ret)
                 return ret;
 
@@ -4759,7 +4767,7 @@ rollback_mesh:
 int netdev_upper_dev_link(struct net_device *dev,
                           struct net_device *upper_dev)
 {
-        return __netdev_upper_dev_link(dev, upper_dev, false);
+        return __netdev_upper_dev_link(dev, upper_dev, false, NULL);
 }
 EXPORT_SYMBOL(netdev_upper_dev_link);
 
@@ -4777,10 +4785,18 @@ EXPORT_SYMBOL(netdev_upper_dev_link);
 int netdev_master_upper_dev_link(struct net_device *dev,
                                  struct net_device *upper_dev)
 {
-        return __netdev_upper_dev_link(dev, upper_dev, true);
+        return __netdev_upper_dev_link(dev, upper_dev, true, NULL);
 }
 EXPORT_SYMBOL(netdev_master_upper_dev_link);
 
+int netdev_master_upper_dev_link_private(struct net_device *dev,
+                                         struct net_device *upper_dev,
+                                         void *private)
+{
+        return __netdev_upper_dev_link(dev, upper_dev, true, private);
+}
+EXPORT_SYMBOL(netdev_master_upper_dev_link_private);
+
 /**
  * netdev_upper_dev_unlink - Removes a link to upper device
  * @dev: device
@@ -4818,6 +4834,36 @@ void netdev_upper_dev_unlink(struct net_device *dev,
 }
 EXPORT_SYMBOL(netdev_upper_dev_unlink);
 
+void *netdev_lower_dev_get_private_rcu(struct net_device *dev,
+                                       struct net_device *lower_dev)
+{
+        struct netdev_adjacent *lower;
+
+        if (!lower_dev)
+                return NULL;
+        lower = __netdev_find_adj_rcu(dev, lower_dev, &dev->adj_list.lower);
+        if (!lower)
+                return NULL;
+
+        return lower->private;
+}
+EXPORT_SYMBOL(netdev_lower_dev_get_private_rcu);
+
+void *netdev_lower_dev_get_private(struct net_device *dev,
+                                   struct net_device *lower_dev)
+{
+        struct netdev_adjacent *lower;
+
+        if (!lower_dev)
+                return NULL;
+        lower = __netdev_find_adj(dev, lower_dev, &dev->adj_list.lower);
+        if (!lower)
+                return NULL;
+
+        return lower->private;
+}
+EXPORT_SYMBOL(netdev_lower_dev_get_private);
+
 static void dev_change_rx_flags(struct net_device *dev, int flags)
 {
         const struct net_device_ops *ops = dev->netdev_ops;