netfilter: netns ebtables: part 2

* return ebt_table from ebt_register_table(), module code will save it into
  per-netns data for unregistration
* duplicate ebt_table at the very beginning of registration -- it's added into
  list, so one ebt_table wouldn't end up in many lists (and each netns has
  different one)
* introduce underscored tables in individial modules, this is temporary to not
  break bisection.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>

5 files changed, 47 insertions, 34 deletions

diff --git a/include/linux/netfilter_bridge/ebtables.h b/include/linux/netfilter_bridge/ebtables.h
index 624e7883068c..e40ddb94b1af 100644
--- a/include/linux/netfilter_bridge/ebtables.h
+++ b/include/linux/netfilter_bridge/ebtables.h
@@ -300,7 +300,8 @@ struct ebt_table
 
 #define EBT_ALIGN(s) (((s) + (__alignof__(struct ebt_replace)-1)) & \
                      ~(__alignof__(struct ebt_replace)-1))
-extern int ebt_register_table(struct net *net, struct ebt_table *table);
+extern struct ebt_table *ebt_register_table(struct net *net,
+                                            struct ebt_table *table);
 extern void ebt_unregister_table(struct ebt_table *table);
 extern unsigned int ebt_do_table(unsigned int hook, struct sk_buff *skb,
    const struct net_device *in, const struct net_device *out,
diff --git a/net/bridge/netfilter/ebtable_broute.c b/net/bridge/netfilter/ebtable_broute.c
index 1731ce8f7479..3277d682dfcf 100644
--- a/net/bridge/netfilter/ebtable_broute.c
+++ b/net/bridge/netfilter/ebtable_broute.c
@@ -41,22 +41,23 @@ static int check(const struct ebt_table_info *info, unsigned int valid_hooks)
         return 0;
 }
 
-static struct ebt_table broute_table =
+static struct ebt_table __broute_table =
 {
         .name           = "broute",
         .table          = &initial_table,
         .valid_hooks    = 1 << NF_BR_BROUTING,
-        .lock           = __RW_LOCK_UNLOCKED(broute_table.lock),
+        .lock           = __RW_LOCK_UNLOCKED(__broute_table.lock),
         .check          = check,
         .me             = THIS_MODULE,
 };
+static struct ebt_table *broute_table;
 
 static int ebt_broute(struct sk_buff *skb)
 {
         int ret;
 
         ret = ebt_do_table(NF_BR_BROUTING, skb, skb->dev, NULL,
-           &broute_table);
+           broute_table);
         if (ret == NF_DROP)
                 return 1; /* route it */
         return 0; /* bridge it */
@@ -64,21 +65,19 @@ static int ebt_broute(struct sk_buff *skb)
 
 static int __init ebtable_broute_init(void)
 {
-        int ret;
-
-        ret = ebt_register_table(&init_net, &broute_table);
-        if (ret < 0)
-                return ret;
+        broute_table = ebt_register_table(&init_net, &__broute_table);
+        if (IS_ERR(broute_table))
+                return PTR_ERR(broute_table);
         /* see br_input.c */
         rcu_assign_pointer(br_should_route_hook, ebt_broute);
-        return ret;
+        return 0;
 }
 
 static void __exit ebtable_broute_fini(void)
 {
         rcu_assign_pointer(br_should_route_hook, NULL);
         synchronize_net();
-        ebt_unregister_table(&broute_table);
+        ebt_unregister_table(broute_table);
 }
 
 module_init(ebtable_broute_init);
diff --git a/net/bridge/netfilter/ebtable_filter.c b/net/bridge/netfilter/ebtable_filter.c
index af8953c9a57c..596564c7aa58 100644
--- a/net/bridge/netfilter/ebtable_filter.c
+++ b/net/bridge/netfilter/ebtable_filter.c
@@ -50,21 +50,22 @@ static int check(const struct ebt_table_info *info, unsigned int valid_hooks)
         return 0;
 }
 
-static struct ebt_table frame_filter =
+static struct ebt_table __frame_filter =
 {
         .name           = "filter",
         .table          = &initial_table,
         .valid_hooks    = FILTER_VALID_HOOKS,
-        .lock           = __RW_LOCK_UNLOCKED(frame_filter.lock),
+        .lock           = __RW_LOCK_UNLOCKED(__frame_filter.lock),
         .check          = check,
         .me             = THIS_MODULE,
 };
+static struct ebt_table *frame_filter;
 
 static unsigned int
 ebt_hook(unsigned int hook, struct sk_buff *skb, const struct net_device *in,
    const struct net_device *out, int (*okfn)(struct sk_buff *))
 {
-        return ebt_do_table(hook, skb, in, out, &frame_filter);
+        return ebt_do_table(hook, skb, in, out, frame_filter);
 }
 
 static struct nf_hook_ops ebt_ops_filter[] __read_mostly = {
@@ -95,19 +96,19 @@ static int __init ebtable_filter_init(void)
 {
         int ret;
 
-        ret = ebt_register_table(&init_net, &frame_filter);
-        if (ret < 0)
-                return ret;
+        frame_filter = ebt_register_table(&init_net, &__frame_filter);
+        if (IS_ERR(frame_filter))
+                return PTR_ERR(frame_filter);
         ret = nf_register_hooks(ebt_ops_filter, ARRAY_SIZE(ebt_ops_filter));
         if (ret < 0)
-                ebt_unregister_table(&frame_filter);
+                ebt_unregister_table(frame_filter);
         return ret;
 }
 
 static void __exit ebtable_filter_fini(void)
 {
         nf_unregister_hooks(ebt_ops_filter, ARRAY_SIZE(ebt_ops_filter));
-        ebt_unregister_table(&frame_filter);
+        ebt_unregister_table(frame_filter);
 }
 
 module_init(ebtable_filter_init);
diff --git a/net/bridge/netfilter/ebtable_nat.c b/net/bridge/netfilter/ebtable_nat.c
index bafe16029bd7..0d8fc5bcddd1 100644
--- a/net/bridge/netfilter/ebtable_nat.c
+++ b/net/bridge/netfilter/ebtable_nat.c
@@ -50,28 +50,29 @@ static int check(const struct ebt_table_info *info, unsigned int valid_hooks)
         return 0;
 }
 
-static struct ebt_table frame_nat =
+static struct ebt_table __frame_nat =
 {
         .name           = "nat",
         .table          = &initial_table,
         .valid_hooks    = NAT_VALID_HOOKS,
-        .lock           = __RW_LOCK_UNLOCKED(frame_nat.lock),
+        .lock           = __RW_LOCK_UNLOCKED(__frame_nat.lock),
         .check          = check,
         .me             = THIS_MODULE,
 };
+static struct ebt_table *frame_nat;
 
 static unsigned int
 ebt_nat_dst(unsigned int hook, struct sk_buff *skb, const struct net_device *in
    , const struct net_device *out, int (*okfn)(struct sk_buff *))
 {
-        return ebt_do_table(hook, skb, in, out, &frame_nat);
+        return ebt_do_table(hook, skb, in, out, frame_nat);
 }
 
 static unsigned int
 ebt_nat_src(unsigned int hook, struct sk_buff *skb, const struct net_device *in
    , const struct net_device *out, int (*okfn)(struct sk_buff *))
 {
-        return ebt_do_table(hook, skb, in, out, &frame_nat);
+        return ebt_do_table(hook, skb, in, out, frame_nat);
 }
 
 static struct nf_hook_ops ebt_ops_nat[] __read_mostly = {
@@ -102,19 +103,19 @@ static int __init ebtable_nat_init(void)
 {
         int ret;
 
-        ret = ebt_register_table(&init_net, &frame_nat);
-        if (ret < 0)
-                return ret;
+        frame_nat = ebt_register_table(&init_net, &__frame_nat);
+        if (IS_ERR(frame_nat))
+                return PTR_ERR(frame_nat);
         ret = nf_register_hooks(ebt_ops_nat, ARRAY_SIZE(ebt_ops_nat));
         if (ret < 0)
-                ebt_unregister_table(&frame_nat);
+                ebt_unregister_table(frame_nat);
         return ret;
 }
 
 static void __exit ebtable_nat_fini(void)
 {
         nf_unregister_hooks(ebt_ops_nat, ARRAY_SIZE(ebt_ops_nat));
-        ebt_unregister_table(&frame_nat);
+        ebt_unregister_table(frame_nat);
 }
 
 module_init(ebtable_nat_init);
diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index c1a82b2826eb..82e17527e21e 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -1098,7 +1098,7 @@ free_newinfo:
         return ret;
 }
 
-int ebt_register_table(struct net *net, struct ebt_table *table)
+struct ebt_table *ebt_register_table(struct net *net, struct ebt_table *table)
 {
         struct ebt_table_info *newinfo;
         struct ebt_table *t;
@@ -1110,14 +1110,21 @@ int ebt_register_table(struct net *net, struct ebt_table *table)
             repl->entries_size == 0 ||
             repl->counters || table->private) {
                 BUGPRINT("Bad table data for ebt_register_table!!!\n");
-                return -EINVAL;
+                return ERR_PTR(-EINVAL);
+        }
+
+        /* Don't add one table to multiple lists. */
+        table = kmemdup(table, sizeof(struct ebt_table), GFP_KERNEL);
+        if (!table) {
+                ret = -ENOMEM;
+                goto out;
         }
 
         countersize = COUNTER_OFFSET(repl->nentries) * nr_cpu_ids;
         newinfo = vmalloc(sizeof(*newinfo) + countersize);
         ret = -ENOMEM;
         if (!newinfo)
-                return -ENOMEM;
+                goto free_table;
 
         p = vmalloc(repl->entries_size);
         if (!p)
@@ -1149,7 +1156,7 @@ int ebt_register_table(struct net *net, struct ebt_table *table)
 
         if (table->check && table->check(newinfo, table->valid_hooks)) {
                 BUGPRINT("The table doesn't like its own initial data, lol\n");
-                return -EINVAL;
+                return ERR_PTR(-EINVAL);
         }
 
         table->private = newinfo;
@@ -1173,7 +1180,7 @@ int ebt_register_table(struct net *net, struct ebt_table *table)
         }
         list_add(&table->list, &net->xt.tables[NFPROTO_BRIDGE]);
         mutex_unlock(&ebt_mutex);
-        return 0;
+        return table;
 free_unlock:
         mutex_unlock(&ebt_mutex);
 free_chainstack:
@@ -1185,7 +1192,10 @@ free_chainstack:
         vfree(newinfo->entries);
 free_newinfo:
         vfree(newinfo);
-        return ret;
+free_table:
+        kfree(table);
+out:
+        return ERR_PTR(ret);
 }
 
 void ebt_unregister_table(struct ebt_table *table)
@@ -1206,6 +1216,7 @@ void ebt_unregister_table(struct ebt_table *table)
                 vfree(table->private->chainstack);
         }
         vfree(table->private);
+        kfree(table);
 }
 
 /* userspace just supplied us with counters */