null.c

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/*
 * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{linux.intel,addtoit}.com)
 * Licensed under the GPL
 */

#include <stddef.h>
#include <errno.h>
#include <fcntl.h>
#include "chan_user.h"
#include <os.h>

/* This address is used only as a unique identifier */
static int null_chan;

static void *null_init(char *str, int device, const struct chan_opts *opts)
{
    return &null_chan;
}

static int null_open(int input, int output, int primary, void *d,
             char **dev_out)
{
    int fd;

    *dev_out = NULL;

    fd = open(DEV_NULL, O_RDWR);
    return (fd < 0) ? -errno : fd;
}

static int null_read(int fd, char *c_out, void *unused)
{
    return -ENODEV;
}

static void null_free(void *data)
{
}

const struct chan_ops null_ops = {
    .type       = "null",
    .init       = null_init,
    .open       = null_open,
    .close      = generic_close,
    .read       = null_read,
    .write      = generic_write,
    .console_write  = generic_console_write,
    .window_size    = generic_window_size,
    .free       = null_free,
    .winch      = 0,
};