Contributors: 2
	  
        
          | Author | 
          Tokens | 
          Token Proportion | 
          Commits | 
          Commit Proportion | 
        
	  
	  
        
        
          | Alan Cox | 
          231 | 
          99.14% | 
          1 | 
          33.33% | 
        
        
          | Greg Kroah-Hartman | 
          2 | 
          0.86% | 
          2 | 
          66.67% | 
        
	  
	  
        
          | Total | 
          233 | 
           | 
          3 | 
           | 
	    
	  
    
 
// SPDX-License-Identifier: GPL-2.0
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/tty.h>
#include <linux/module.h>
/*
 *  n_null.c - Null line discipline used in the failure path
 *
 *  Copyright (C) Intel 2017
 */
static int n_null_open(struct tty_struct *tty)
{
	return 0;
}
static void n_null_close(struct tty_struct *tty)
{
}
static ssize_t n_null_read(struct tty_struct *tty, struct file *file,
			   unsigned char __user * buf, size_t nr)
{
	return -EOPNOTSUPP;
}
static ssize_t n_null_write(struct tty_struct *tty, struct file *file,
			    const unsigned char *buf, size_t nr)
{
	return -EOPNOTSUPP;
}
static void n_null_receivebuf(struct tty_struct *tty,
				 const unsigned char *cp, char *fp,
				 int cnt)
{
}
static struct tty_ldisc_ops null_ldisc = {
	.owner		=	THIS_MODULE,
	.magic		=	TTY_LDISC_MAGIC,
	.name		=	"n_null",
	.open		=	n_null_open,
	.close		=	n_null_close,
	.read		=	n_null_read,
	.write		=	n_null_write,
	.receive_buf	=	n_null_receivebuf
};
static int __init n_null_init(void)
{
	BUG_ON(tty_register_ldisc(N_NULL, &null_ldisc));
	return 0;
}
static void __exit n_null_exit(void)
{
	tty_unregister_ldisc(N_NULL);
}
module_init(n_null_init);
module_exit(n_null_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Alan Cox");
MODULE_ALIAS_LDISC(N_NULL);
MODULE_DESCRIPTION("Null ldisc driver");