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-rw-r--r--net/core/dev.c34
1 files changed, 34 insertions, 0 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index fc1e289397f5..faebb398fb46 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -792,6 +792,40 @@ struct net_device *dev_get_by_index(struct net *net, int ifindex)
EXPORT_SYMBOL(dev_get_by_index);
/**
+ * netdev_get_name - get a netdevice name, knowing its ifindex.
+ * @net: network namespace
+ * @name: a pointer to the buffer where the name will be stored.
+ * @ifindex: the ifindex of the interface to get the name from.
+ *
+ * The use of raw_seqcount_begin() and cond_resched() before
+ * retrying is required as we want to give the writers a chance
+ * to complete when CONFIG_PREEMPT is not set.
+ */
+int netdev_get_name(struct net *net, char *name, int ifindex)
+{
+ struct net_device *dev;
+ unsigned int seq;
+
+retry:
+ seq = raw_seqcount_begin(&devnet_rename_seq);
+ rcu_read_lock();
+ dev = dev_get_by_index_rcu(net, ifindex);
+ if (!dev) {
+ rcu_read_unlock();
+ return -ENODEV;
+ }
+
+ strcpy(name, dev->name);
+ rcu_read_unlock();
+ if (read_seqcount_retry(&devnet_rename_seq, seq)) {
+ cond_resched();
+ goto retry;
+ }
+
+ return 0;
+}
+
+/**
* dev_getbyhwaddr_rcu - find a device by its hardware address
* @net: the applicable net namespace
* @type: media type of device