diff options
Diffstat (limited to 'net/core/dev.c')
| -rw-r--r-- | net/core/dev.c | 24 |
1 files changed, 17 insertions, 7 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index b4c67a5be606..9d1a8fac793f 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -11067,6 +11067,8 @@ EXPORT_SYMBOL(unregister_netdev); * @net: network namespace * @pat: If not NULL name pattern to try if the current device name * is already taken in the destination network namespace. + * @new_ifindex: If not zero, specifies device index in the target + * namespace. * * This function shuts down a device interface and moves it * to a new network namespace. On success 0 is returned, on @@ -11075,10 +11077,11 @@ EXPORT_SYMBOL(unregister_netdev); * Callers must hold the rtnl semaphore. */ -int dev_change_net_namespace(struct net_device *dev, struct net *net, const char *pat) +int dev_change_net_namespace(struct net_device *dev, struct net *net, + const char *pat, int new_ifindex) { struct net *net_old = dev_net(dev); - int err, new_nsid, new_ifindex; + int err, new_nsid; ASSERT_RTNL(); @@ -11109,6 +11112,11 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char goto out; } + /* Check that new_ifindex isn't used yet. */ + err = -EBUSY; + if (new_ifindex && __dev_get_by_index(net, new_ifindex)) + goto out; + /* * And now a mini version of register_netdevice unregister_netdevice. */ @@ -11136,10 +11144,12 @@ int dev_change_net_namespace(struct net_device *dev, struct net *net, const char new_nsid = peernet2id_alloc(dev_net(dev), net, GFP_KERNEL); /* If there is an ifindex conflict assign a new one */ - if (__dev_get_by_index(net, dev->ifindex)) - new_ifindex = dev_new_index(net); - else - new_ifindex = dev->ifindex; + if (!new_ifindex) { + if (__dev_get_by_index(net, dev->ifindex)) + new_ifindex = dev_new_index(net); + else + new_ifindex = dev->ifindex; + } rtmsg_ifinfo_newnet(RTM_DELLINK, dev, ~0U, GFP_KERNEL, &new_nsid, new_ifindex); @@ -11448,7 +11458,7 @@ static void __net_exit default_device_exit(struct net *net) snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex); if (__dev_get_by_name(&init_net, fb_name)) snprintf(fb_name, IFNAMSIZ, "dev%%d"); - err = dev_change_net_namespace(dev, &init_net, fb_name); + err = dev_change_net_namespace(dev, &init_net, fb_name, 0); if (err) { pr_emerg("%s: failed to move %s to init_net: %d\n", __func__, dev->name, err); |