net/tun: Call type change netdev notifiers

Call netdev notifiers before and after changing the device type.

Signed-off-by: Martin Schiller <ms@dev.tdt.de>
Link: https://lore.kernel.org/r/20201118063919.29485-1-ms@dev.tdt.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 3d45d56..7c62d82 100644 (file)
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -3071,10 +3071,19 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd,
                                   "Linktype set failed because interface is up\n");
                        ret = -EBUSY;
                } else {
+                       ret = call_netdevice_notifiers(NETDEV_PRE_TYPE_CHANGE,
+                                                      tun->dev);
+                       ret = notifier_to_errno(ret);
+                       if (ret) {
+                               netif_info(tun, drv, tun->dev,
+                                          "Refused to change device type\n");
+                               break;
+                       }
                        tun->dev->type = (int) arg;
                        netif_info(tun, drv, tun->dev, "linktype set to %d\n",
                                   tun->dev->type);
-                       ret = 0;
+                       call_netdevice_notifiers(NETDEV_POST_TYPE_CHANGE,
+                                                tun->dev);
                }
                break;