device: cleanup register_netdev logic

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 7 insertions, 15 deletions

diff --git a/src/device.c b/src/device.c
index fb5f148..2d61502 100644
--- a/src/device.c
+++ b/src/device.c
@@ -240,9 +240,7 @@ static void destruct(struct net_device *dev)
 	put_net(wg->creating_net);
 
 	pr_debug("%s: Interface deleted\n", dev->name);
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 11, 9)
 	free_netdev(dev);
-#endif
 }
 
 static void setup(struct net_device *dev)
@@ -251,12 +249,6 @@ static void setup(struct net_device *dev)
 	enum { WG_NETDEV_FEATURES = NETIF_F_HW_CSUM | NETIF_F_RXCSUM | NETIF_F_SG | NETIF_F_GSO | NETIF_F_GSO_SOFTWARE | NETIF_F_HIGHDMA };
 
 	dev->netdev_ops = &netdev_ops;
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 11, 9)
-	dev->destructor = destruct;
-#else
-	dev->priv_destructor = destruct;
-	dev->needs_free_netdev = true;
-#endif
 	dev->hard_header_len = 0;
 	dev->addr_len = 0;
 	dev->needed_headroom = DATA_PACKET_HEAD_ROOM;
@@ -337,21 +329,21 @@ static int newlink(struct net *src_net, struct net_device *dev, struct nlattr *t
 	if (ret < 0)
 		goto error_8;
 
-	list_add(&wg->device_list, &device_list);
-
 	ret = register_netdevice(dev);
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 11, 9)
 	if (ret < 0)
 		goto error_9;
-#endif
+
+	list_add(&wg->device_list, &device_list);
+
+	/* We wait until the end to assign priv_destructor, so that register_netdevice doesn't
+	 * call it for us if it fails. */
+	dev->priv_destructor = destruct;
+
 	pr_debug("%s: Interface created\n", dev->name);
 	return ret;
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 11, 9)
 error_9:
-	list_del(&wg->device_list);
 	ratelimiter_uninit();
-#endif
 error_8:
 #ifdef CONFIG_WIREGUARD_PARALLEL
 	padata_free(wg->decrypt_pd);