Commit 12b6f706 authored by Nicolas Dichtel's avatar Nicolas Dichtel Committed by Paolo Abeni
Browse files

net: plumb extack in __dev_change_net_namespace() 



It could be hard to understand why the netlink command fails. For example,
if dev->netns_immutable is set, the error is "Invalid argument".

Signed-off-by: default avatarNicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: default avatarPaolo Abeni <pabeni@redhat.com>
parent 4754affe

include/linux/netdevice.h

+3 −2
Original line number Diff line number Diff line
@@ -4191,12 +4191,13 @@ 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);

net/core/dev.c

+34 −9
Original line number Diff line number Diff line
@@ -12131,6 +12131,7 @@ 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
@@ -12140,7 +12141,8 @@ 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);
@@ -12151,12 +12153,16 @@ 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_immutable)

	if (dev->netns_immutable) {

		NL_SET_ERR_MSG(extack, "The interface netns is immutable");

		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;
@@ -12169,30 +12175,49 @@ 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 in the target netns",

					   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))

	netdev_for_each_altname(dev, name_node) {

		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;

	}

net/core/rtnetlink.c

+1 −1
Original line number Diff line number Diff line
@@ -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;