[NETFILTER]: x_tables: netns propagation for /proc/net/*_tables_names

Propagate netns together with AF down to ->start/->next/->stop
iterators. Choose table based on netns and AF for showing.
Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/netfilter/x_tables.c

@@ -720,27 +720,33 @@ void *xt_unregister_table(struct xt_table *table)
 EXPORT_SYMBOL_GPL(xt_unregister_table);
 
 #ifdef CONFIG_PROC_FS
+struct xt_names_priv {
+	struct seq_net_private p;
+	int af;
+};
 static void *xt_table_seq_start(struct seq_file *seq, loff_t *pos)
 {
-	struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;
-	u_int16_t af = (unsigned long)pde->data;
+	struct xt_names_priv *priv = seq->private;
+	struct net *net = priv->p.net;
+	int af = priv->af;
 
 	mutex_lock(&xt[af].mutex);
-	return seq_list_start(&init_net.xt.tables[af], *pos);
+	return seq_list_start(&net->xt.tables[af], *pos);
 }
 
 static void *xt_table_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
-	struct proc_dir_entry *pde = (struct proc_dir_entry *)seq->private;
-	u_int16_t af = (unsigned long)pde->data;
+	struct xt_names_priv *priv = seq->private;
+	struct net *net = priv->p.net;
+	int af = priv->af;
 
-	return seq_list_next(v, &init_net.xt.tables[af], pos);
+	return seq_list_next(v, &net->xt.tables[af], pos);
 }
 
 static void xt_table_seq_stop(struct seq_file *seq, void *v)
 {
-	struct proc_dir_entry *pde = seq->private;
-	u_int16_t af = (unsigned long)pde->data;
+	struct xt_names_priv *priv = seq->private;
+	int af = priv->af;
 
 	mutex_unlock(&xt[af].mutex);
 }
@@ -765,12 +771,13 @@ static const struct seq_operations xt_table_seq_ops = {
 static int xt_table_open(struct inode *inode, struct file *file)
 {
 	int ret;
+	struct xt_names_priv *priv;
 
-	ret = seq_open(file, &xt_table_seq_ops);
+	ret = seq_open_net(inode, file, &xt_table_seq_ops,
+			   sizeof(struct xt_names_priv));
 	if (!ret) {
-		struct seq_file *seq = file->private_data;
-
-		seq->private = PDE(inode);
+		priv = ((struct seq_file *)file->private_data)->private;
+		priv->af = (unsigned long)PDE(inode)->data;
 	}
 	return ret;
 }