null.c (980B)
1// SPDX-License-Identifier: GPL-2.0 2/* 3 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com) 4 */ 5 6#include <stddef.h> 7#include <errno.h> 8#include <fcntl.h> 9#include "chan_user.h" 10#include <os.h> 11 12/* This address is used only as a unique identifier */ 13static int null_chan; 14 15static void *null_init(char *str, int device, const struct chan_opts *opts) 16{ 17 return &null_chan; 18} 19 20static int null_open(int input, int output, int primary, void *d, 21 char **dev_out) 22{ 23 int fd; 24 25 *dev_out = NULL; 26 27 fd = open(DEV_NULL, O_RDWR); 28 return (fd < 0) ? -errno : fd; 29} 30 31static int null_read(int fd, char *c_out, void *unused) 32{ 33 return -ENODEV; 34} 35 36static void null_free(void *data) 37{ 38} 39 40const struct chan_ops null_ops = { 41 .type = "null", 42 .init = null_init, 43 .open = null_open, 44 .close = generic_close, 45 .read = null_read, 46 .write = generic_write, 47 .console_write = generic_console_write, 48 .window_size = generic_window_size, 49 .free = null_free, 50 .winch = 0, 51};