Commit b61ad68a authored by Christian Brauner's avatar Christian Brauner Committed by David S. Miller
Browse files

rtnetlink: enable IFLA_IF_NETNSID for RTM_DELLINK 



- Backwards Compatibility:
  If userspace wants to determine whether RTM_DELLINK supports the
  IFLA_IF_NETNSID property they should first send an RTM_GETLINK request
  with IFLA_IF_NETNSID on lo. If either EACCESS is returned or the reply
  does not include IFLA_IF_NETNSID userspace should assume that
  IFLA_IF_NETNSID is not supported on this kernel.
  If the reply does contain an IFLA_IF_NETNSID property userspace
  can send an RTM_DELLINK with a IFLA_IF_NETNSID property. If they receive
  EOPNOTSUPP then the kernel does not support the IFLA_IF_NETNSID property
  with RTM_DELLINK. Userpace should then fallback to other means.

- Security:
  Callers must have CAP_NET_ADMIN in the owning user namespace of the
  target network namespace.

Signed-off-by: default avatarChristian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent c310bfcb

net/core/rtnetlink.c

+28 −11
Original line number Diff line number Diff line
@@ -2639,36 +2639,53 @@ static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh, 
			struct netlink_ext_ack *extack)

{

	struct net *net = sock_net(skb->sk);

	struct net_device *dev;

	struct net *tgt_net = net;

	struct net_device *dev = NULL;

	struct ifinfomsg *ifm;

	char ifname[IFNAMSIZ];

	struct nlattr *tb[IFLA_MAX+1];

	int err;

	int netnsid = -1;



	err = nlmsg_parse(nlh, sizeof(*ifm), tb, IFLA_MAX, ifla_policy, extack);

	if (err < 0)

		return err;



	if (tb[IFLA_IF_NETNSID])

		return -EOPNOTSUPP;



	if (tb[IFLA_IFNAME])

		nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);



	if (tb[IFLA_IF_NETNSID]) {

		netnsid = nla_get_s32(tb[IFLA_IF_NETNSID]);

		tgt_net = get_target_net(NETLINK_CB(skb).sk, netnsid);

		if (IS_ERR(tgt_net))

			return PTR_ERR(tgt_net);

	}



	err = -EINVAL;

	ifm = nlmsg_data(nlh);

	if (ifm->ifi_index > 0)

		dev = __dev_get_by_index(net, ifm->ifi_index);

		dev = __dev_get_by_index(tgt_net, ifm->ifi_index);

	else if (tb[IFLA_IFNAME])

		dev = __dev_get_by_name(net, ifname);

		dev = __dev_get_by_name(tgt_net, ifname);

	else if (tb[IFLA_GROUP])

		return rtnl_group_dellink(net, nla_get_u32(tb[IFLA_GROUP]));

		err = rtnl_group_dellink(tgt_net, nla_get_u32(tb[IFLA_GROUP]));

	else

		return -EINVAL;

		goto out;



	if (!dev)

		return -ENODEV;

	if (!dev) {

		if (tb[IFLA_IFNAME] || ifm->ifi_index > 0)

			err = -ENODEV;



	return rtnl_delete_link(dev);

		goto out;

	}



	err = rtnl_delete_link(dev);



out:

	if (netnsid >= 0)

		put_net(tgt_net);



	return err;

}



int rtnl_configure_link(struct net_device *dev, const struct ifinfomsg *ifm)

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