@@ -4155,12 +4155,13 @@ int dev_change_flags(struct net_device *dev, unsigned int flags,
int dev_set_alias(struct net_device *, const char *, size_t);
int dev_get_alias(const struct net_device *, char *, size_t);
int __dev_change_net_namespace(struct net_device *dev, struct net *net,
- const char *pat, int new_ifindex);
+ const char *pat, int new_ifindex,
+ struct netlink_ext_ack *extack);
static inline
int dev_change_net_namespace(struct net_device *dev, struct net *net,
const char *pat)
{
- return __dev_change_net_namespace(dev, net, pat, 0);
+ return __dev_change_net_namespace(dev, net, pat, 0, NULL);
}
int __dev_set_mtu(struct net_device *, int);
int dev_set_mtu(struct net_device *, int);
@@ -11917,6 +11917,7 @@ EXPORT_SYMBOL(unregister_netdev);
* is already taken in the destination network namespace.
* @new_ifindex: If not zero, specifies device index in the target
* namespace.
+ * @extack: netlink extended ack
*
* This function shuts down a device interface and moves it
* to a new network namespace. On success 0 is returned, on
@@ -11926,7 +11927,8 @@ EXPORT_SYMBOL(unregister_netdev);
*/
int __dev_change_net_namespace(struct net_device *dev, struct net *net,
- const char *pat, int new_ifindex)
+ const char *pat, int new_ifindex,
+ struct netlink_ext_ack *extack)
{
struct netdev_name_node *name_node;
struct net *net_old = dev_net(dev);
@@ -11937,12 +11939,17 @@ int __dev_change_net_namespace(struct net_device *dev, struct net *net,
/* Don't allow namespace local devices to be moved. */
err = -EINVAL;
- if (dev->netns_local)
+ if (dev->netns_local) {
+ NL_SET_ERR_MSG(extack,
+ "The interface has the 'netns local' property");
goto out;
+ }
/* Ensure the device has been registered */
- if (dev->reg_state != NETREG_REGISTERED)
+ if (dev->reg_state != NETREG_REGISTERED) {
+ NL_SET_ERR_MSG(extack, "The interface isn't registered");
goto out;
+ }
/* Get out if there is nothing todo */
err = 0;
@@ -11955,30 +11962,48 @@ int __dev_change_net_namespace(struct net_device *dev, struct net *net,
err = -EEXIST;
if (netdev_name_in_use(net, dev->name)) {
/* We get here if we can't use the current device name */
- if (!pat)
+ if (!pat) {
+ NL_SET_ERR_MSG(extack,
+ "An interface with the same name exists in the target netns");
goto out;
+ }
err = dev_prep_valid_name(net, dev, pat, new_name, EEXIST);
- if (err < 0)
+ if (err < 0) {
+ NL_SET_ERR_MSG_FMT(extack,
+ "Unable to use '%s' for the new interface name",
+ pat);
goto out;
+ }
}
/* Check that none of the altnames conflicts. */
err = -EEXIST;
netdev_for_each_altname(dev, name_node)
- if (netdev_name_in_use(net, name_node->name))
+ if (netdev_name_in_use(net, name_node->name)) {
+ NL_SET_ERR_MSG_FMT(extack,
+ "An interface with the altname %s exists in the target netns",
+ name_node->name);
goto out;
+ }
/* Check that new_ifindex isn't used yet. */
if (new_ifindex) {
err = dev_index_reserve(net, new_ifindex);
- if (err < 0)
+ if (err < 0) {
+ NL_SET_ERR_MSG_FMT(extack,
+ "The ifindex %d is not available in the target netns",
+ new_ifindex);
goto out;
+ }
} else {
/* If there is an ifindex conflict assign a new one */
err = dev_index_reserve(net, dev->ifindex);
if (err == -EBUSY)
err = dev_index_reserve(net, 0);
- if (err < 0)
+ if (err < 0) {
+ NL_SET_ERR_MSG(extack,
+ "Unable to allocate a new ifindex in the target netns");
goto out;
+ }
new_ifindex = err;
}
@@ -3028,7 +3028,7 @@ static int do_setlink(const struct sk_buff *skb, struct net_device *dev,
new_ifindex = nla_get_s32_default(tb[IFLA_NEW_IFINDEX], 0);
- err = __dev_change_net_namespace(dev, tgt_net, pat, new_ifindex);
+ err = __dev_change_net_namespace(dev, tgt_net, pat, new_ifindex, extack);
if (err)
goto errout;
It could be hard to understand why the netlink command fails. For example, if dev->netns_local is set, the error is "Invalid argument". Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> --- include/linux/netdevice.h | 5 +++-- net/core/dev.c | 41 +++++++++++++++++++++++++++++++-------- net/core/rtnetlink.c | 2 +- 3 files changed, 37 insertions(+), 11 deletions(-)