Merge tag 'nfs-for-5.15-1' of git://git.linux-nfs.org/projects/anna/linux-nfs

[linux-2.6-microblaze.git] / net / netfilter / x_tables.c

diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c
index 84e58ee..25524e3 100644 (file)
--- a/net/netfilter/x_tables.c
+++ b/net/netfilter/x_tables.c
@@ -39,6 +39,20 @@ MODULE_DESCRIPTION("{ip,ip6,arp,eb}_tables backend module");
 #define XT_PCPU_BLOCK_SIZE 4096
 #define XT_MAX_TABLE_SIZE      (512 * 1024 * 1024)
 
+struct xt_template {
+       struct list_head list;
+
+       /* called when table is needed in the given netns */
+       int (*table_init)(struct net *net);
+
+       struct module *me;
+
+       /* A unique name... */
+       char name[XT_TABLE_MAXNAMELEN];
+};
+
+static struct list_head xt_templates[NFPROTO_NUMPROTO];
+
 struct xt_pernet {
        struct list_head tables[NFPROTO_NUMPROTO];
 };
@@ -1221,48 +1235,43 @@ struct xt_table *xt_find_table_lock(struct net *net, u_int8_t af,
                                    const char *name)
 {
        struct xt_pernet *xt_net = net_generic(net, xt_pernet_id);
-       struct xt_table *t, *found = NULL;
+       struct module *owner = NULL;
+       struct xt_template *tmpl;
+       struct xt_table *t;
 
        mutex_lock(&xt[af].mutex);
        list_for_each_entry(t, &xt_net->tables[af], list)
                if (strcmp(t->name, name) == 0 && try_module_get(t->me))
                        return t;
 
-       if (net == &init_net)
-               goto out;
-
-       /* Table doesn't exist in this netns, re-try init */
-       xt_net = net_generic(&init_net, xt_pernet_id);
-       list_for_each_entry(t, &xt_net->tables[af], list) {
+       /* Table doesn't exist in this netns, check larval list */
+       list_for_each_entry(tmpl, &xt_templates[af], list) {
                int err;
 
-               if (strcmp(t->name, name))
+               if (strcmp(tmpl->name, name))
                        continue;
-               if (!try_module_get(t->me))
+               if (!try_module_get(tmpl->me))
                        goto out;
+
+               owner = tmpl->me;
+
                mutex_unlock(&xt[af].mutex);
-               err = t->table_init(net);
+               err = tmpl->table_init(net);
                if (err < 0) {
-                       module_put(t->me);
+                       module_put(owner);
                        return ERR_PTR(err);
                }
 
-               found = t;
-
                mutex_lock(&xt[af].mutex);
                break;
        }
 
-       if (!found)
-               goto out;
-
-       xt_net = net_generic(net, xt_pernet_id);
        /* and once again: */
        list_for_each_entry(t, &xt_net->tables[af], list)
                if (strcmp(t->name, name) == 0)
                        return t;
 
-       module_put(found->me);
+       module_put(owner);
  out:
        mutex_unlock(&xt[af].mutex);
        return ERR_PTR(-ENOENT);
@@ -1749,6 +1758,58 @@ xt_hook_ops_alloc(const struct xt_table *table, nf_hookfn *fn)
 }
 EXPORT_SYMBOL_GPL(xt_hook_ops_alloc);
 
+int xt_register_template(const struct xt_table *table,
+                        int (*table_init)(struct net *net))
+{
+       int ret = -EEXIST, af = table->af;
+       struct xt_template *t;
+
+       mutex_lock(&xt[af].mutex);
+
+       list_for_each_entry(t, &xt_templates[af], list) {
+               if (WARN_ON_ONCE(strcmp(table->name, t->name) == 0))
+                       goto out_unlock;
+       }
+
+       ret = -ENOMEM;
+       t = kzalloc(sizeof(*t), GFP_KERNEL);
+       if (!t)
+               goto out_unlock;
+
+       BUILD_BUG_ON(sizeof(t->name) != sizeof(table->name));
+
+       strscpy(t->name, table->name, sizeof(t->name));
+       t->table_init = table_init;
+       t->me = table->me;
+       list_add(&t->list, &xt_templates[af]);
+       ret = 0;
+out_unlock:
+       mutex_unlock(&xt[af].mutex);
+       return ret;
+}
+EXPORT_SYMBOL_GPL(xt_register_template);
+
+void xt_unregister_template(const struct xt_table *table)
+{
+       struct xt_template *t;
+       int af = table->af;
+
+       mutex_lock(&xt[af].mutex);
+       list_for_each_entry(t, &xt_templates[af], list) {
+               if (strcmp(table->name, t->name))
+                       continue;
+
+               list_del(&t->list);
+               mutex_unlock(&xt[af].mutex);
+               kfree(t);
+               return;
+       }
+
+       mutex_unlock(&xt[af].mutex);
+       WARN_ON_ONCE(1);
+}
+EXPORT_SYMBOL_GPL(xt_unregister_template);
+
 int xt_proto_init(struct net *net, u_int8_t af)
 {
 #ifdef CONFIG_PROC_FS
@@ -1937,6 +1998,7 @@ static int __init xt_init(void)
 #endif
                INIT_LIST_HEAD(&xt[i].target);
                INIT_LIST_HEAD(&xt[i].match);
+               INIT_LIST_HEAD(&xt_templates[i]);
        }
        rv = register_pernet_subsys(&xt_net_ops);
        if (rv < 0)