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 <>
Signed-off-by: default avatarDavid S. Miller <>
parent c310bfcb
......@@ -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_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]));
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);
if (netnsid >= 0)
return err;
int rtnl_configure_link(struct net_device *dev, const struct ifinfomsg *ifm)
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