netfilter: nf_tables: allow netdevice to be used only once per flowtable

Allow netdevice only once per flowtable, otherwise hit EEXIST.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This commit is contained in:
Pablo Neira Ayuso 2019-10-16 14:25:05 +02:00
parent 3f0465a9ef
commit b75a3e8371

View File

@ -1538,6 +1538,19 @@ err_hook_alloc:
return ERR_PTR(err);
}
static bool nft_hook_list_find(struct list_head *hook_list,
const struct nft_hook *this)
{
struct nft_hook *hook;
list_for_each_entry(hook, hook_list, list) {
if (this->ops.dev == hook->ops.dev)
return true;
}
return false;
}
static int nf_tables_parse_netdev_hooks(struct net *net,
const struct nlattr *attr,
struct list_head *hook_list)
@ -1557,6 +1570,10 @@ static int nf_tables_parse_netdev_hooks(struct net *net,
err = PTR_ERR(hook);
goto err_hook;
}
if (nft_hook_list_find(hook_list, hook)) {
err = -EEXIST;
goto err_hook;
}
list_add_tail(&hook->list, hook_list);
n++;