net: add netdev_upper_get_next_dev_rcu(dev, iter)
This function returns the next dev in the dev->upper_dev_list after the
struct list_head **iter position, and updates *iter accordingly. Returns
NULL if there are no devices left.
Caller must hold RCU read lock.
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>
CC: Cong Wang <amwang@redhat.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 749925a..6fbb0c9 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4468,6 +4468,31 @@
}
EXPORT_SYMBOL(netdev_master_upper_dev_get);
+/* netdev_upper_get_next_dev_rcu - Get the next dev from upper list
+ * @dev: device
+ * @iter: list_head ** of the current position
+ *
+ * Gets the next device from the dev's upper list, starting from iter
+ * position. The caller must hold RCU read lock.
+ */
+struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev,
+ struct list_head **iter)
+{
+ struct netdev_adjacent *upper;
+
+ WARN_ON_ONCE(!rcu_read_lock_held());
+
+ upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
+
+ if (&upper->list == &dev->upper_dev_list)
+ return NULL;
+
+ *iter = &upper->list;
+
+ return upper->dev;
+}
+EXPORT_SYMBOL(netdev_upper_get_next_dev_rcu);
+
/**
* netdev_master_upper_dev_get_rcu - Get master upper device
* @dev: device