ip6_gre: don't allow to remove the fb_tunnel_dev

It's possible to remove the FB tunnel with the command 'ip link del ip6gre0' but
this is unsafe, the module always supposes that this device exists. For example,
ip6gre_tunnel_lookup() may use it unconditionally.

Let's add a rtnl handler for dellink, which will never remove the FB tunnel (we
let ip6gre_destroy_tunnels() do the job).

Introduced by commit c12b395a46 ("gre: Support GRE over IPv6").

CC: Dmitry Kozlov <xeb@mail.ru>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Nicolas Dichtel 2014-04-14 17:11:38 +02:00 committed by David S. Miller
parent aad88724c9
commit 54d63f787b

View File

@ -1559,6 +1559,15 @@ static int ip6gre_changelink(struct net_device *dev, struct nlattr *tb[],
return 0;
}
static void ip6gre_dellink(struct net_device *dev, struct list_head *head)
{
struct net *net = dev_net(dev);
struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);
if (dev != ign->fb_tunnel_dev)
unregister_netdevice_queue(dev, head);
}
static size_t ip6gre_get_size(const struct net_device *dev)
{
return
@ -1636,6 +1645,7 @@ static struct rtnl_link_ops ip6gre_link_ops __read_mostly = {
.validate = ip6gre_tunnel_validate,
.newlink = ip6gre_newlink,
.changelink = ip6gre_changelink,
.dellink = ip6gre_dellink,
.get_size = ip6gre_get_size,
.fill_info = ip6gre_fill_info,
};