/************************************************************ * dev_null.c * * Copyright (C) 2007 Gregory Nutt. All rights reserved. * Author: Gregory Nutt * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name Gregory Nutt nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ************************************************************/ /************************************************************ * Compilation Switches ************************************************************/ /************************************************************ * Included Files ************************************************************/ #include #include #include #include #include /************************************************************ * Private Function Prototypes ************************************************************/ static ssize_t devnull_read(struct file *, char *, size_t); static ssize_t devnull_write(struct file *, const char *, size_t); /************************************************************ * Private Data ************************************************************/ static struct file_operations devnull_fops = { 0, /* open */ 0, /* close */ devnull_read, /* read */ devnull_write, /* write */ 0, /* seek */ 0 /* ioctl */ }; /************************************************************ * Private Functions ************************************************************/ static ssize_t devnull_read(struct file *filp, char *buffer, size_t len) { return 0; /* Return EOF */ } static ssize_t devnull_write(struct file *filp, const char *buffer, size_t len) { return len; /* Say that everything was written */ } /************************************************************ * Public Functions ************************************************************/ void devnull_register(void) { (void)register_driver("/dev/null", &devnull_fops, 0666, NULL); }