Commit b7eddd0b authored by Antonio Quartulli's avatar Antonio Quartulli

batman-adv: prevent using any virtual device created on batman-adv as hard-interface

Any virtual device created on top of a batman-adv mesh interface must be
prevented to be used to create a new mesh network (this would lead to an
unwanted batman-over-batman configuration)
Signed-off-by: default avatarAntonio Quartulli <ordex@autistici.org>
parent a7528f8d
......@@ -59,6 +59,45 @@ batadv_hardif_get_by_netdev(const struct net_device *net_dev)
return hard_iface;
}
/**
* batadv_is_on_batman_iface - check if a device is a batman iface descendant
* @net_dev: the device to check
*
* If the user creates any virtual device on top of a batman-adv interface, it
* is important to prevent this new interface to be used to create a new mesh
* network (this behaviour would lead to a batman-over-batman configuration).
* This function recursively checks all the fathers of the device passed as
* argument looking for a batman-adv soft interface.
*
* Returns true if the device is descendant of a batman-adv mesh interface (or
* if it is a batman-adv interface itself), false otherwise
*/
static bool batadv_is_on_batman_iface(const struct net_device *net_dev)
{
struct net_device *parent_dev;
bool ret;
/* check if this is a batman-adv mesh interface */
if (batadv_softif_is_valid(net_dev))
return true;
/* no more parents..stop recursion */
if (net_dev->iflink == net_dev->ifindex)
return false;
/* recurse over the parent device */
parent_dev = dev_get_by_index(&init_net, net_dev->iflink);
/* if we got a NULL parent_dev there is something broken.. */
if (WARN(!parent_dev, "Cannot find parent device"))
return false;
ret = batadv_is_on_batman_iface(parent_dev);
if (parent_dev)
dev_put(parent_dev);
return ret;
}
static int batadv_is_valid_iface(const struct net_device *net_dev)
{
if (net_dev->flags & IFF_LOOPBACK)
......@@ -71,7 +110,7 @@ static int batadv_is_valid_iface(const struct net_device *net_dev)
return 0;
/* no batman over batman */
if (batadv_softif_is_valid(net_dev))
if (batadv_is_on_batman_iface(net_dev))
return 0;
return 1;
......
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