net: add for_each iterators through neighbour lower link's private
Add a possibility to iterate through netdev_adjacent's private, currently
only for lower neighbours.
Add both RCU and RTNL/other locking variants of iterators, and make the
non-rcu variant to be safe from removal.
CC: "David S. Miller" <davem@davemloft.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Jiri Pirko <jiri@resnulli.us>
CC: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index c69ab74..0aa844a 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4466,7 +4466,8 @@
}
EXPORT_SYMBOL(netdev_master_upper_dev_get);
-/* netdev_all_upper_get_next_dev_rcu - Get the next dev from upper list
+/**
+ * netdev_all_upper_get_next_dev_rcu - Get the next dev from upper list
* @dev: device
* @iter: list_head ** of the current position
*
@@ -4492,6 +4493,63 @@
EXPORT_SYMBOL(netdev_all_upper_get_next_dev_rcu);
/**
+ * netdev_lower_get_next_private - Get the next ->private from the
+ * lower neighbour list
+ * @dev: device
+ * @iter: list_head ** of the current position
+ *
+ * Gets the next netdev_adjacent->private from the dev's lower neighbour
+ * list, starting from iter position. The caller must hold either hold the
+ * RTNL lock or its own locking that guarantees that the neighbour lower
+ * list will remain unchainged.
+ */
+void *netdev_lower_get_next_private(struct net_device *dev,
+ struct list_head **iter)
+{
+ struct netdev_adjacent *lower;
+
+ lower = list_entry(*iter, struct netdev_adjacent, list);
+
+ if (&lower->list == &dev->adj_list.lower)
+ return NULL;
+
+ if (iter)
+ *iter = lower->list.next;
+
+ return lower->private;
+}
+EXPORT_SYMBOL(netdev_lower_get_next_private);
+
+/**
+ * netdev_lower_get_next_private_rcu - Get the next ->private from the
+ * lower neighbour list, RCU
+ * variant
+ * @dev: device
+ * @iter: list_head ** of the current position
+ *
+ * Gets the next netdev_adjacent->private from the dev's lower neighbour
+ * list, starting from iter position. The caller must hold RCU read lock.
+ */
+void *netdev_lower_get_next_private_rcu(struct net_device *dev,
+ struct list_head **iter)
+{
+ struct netdev_adjacent *lower;
+
+ WARN_ON_ONCE(!rcu_read_lock_held());
+
+ lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
+
+ if (&lower->list == &dev->adj_list.lower)
+ return NULL;
+
+ if (iter)
+ *iter = &lower->list;
+
+ return lower->private;
+}
+EXPORT_SYMBOL(netdev_lower_get_next_private_rcu);
+
+/**
* netdev_master_upper_dev_get_rcu - Get master upper device
* @dev: device
*
