1/*-
2 * Copyright (c) 2009 Ed Schouten <ed@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD$");
29
30#include <sys/param.h>
31#include <sys/conf.h>
32#include <sys/kernel.h>
33#include <sys/malloc.h>
34#include <sys/module.h>
35#include <sys/systm.h>
36#include <sys/uio.h>
37
38#include <dev/lindev/lindev.h>
39
40static struct cdev *full_dev;
41
42static d_read_t full_read;
43static d_write_t full_write;
44
45static struct cdevsw full_cdevsw = {
46	.d_version =	D_VERSION,
47	.d_read =	full_read,
48	.d_write =	full_write,
49	.d_name =	"full",
50};
51
52static void *zbuf;
53
54/* ARGSUSED */
55static int
56full_read(struct cdev *dev __unused, struct uio *uio, int flags __unused)
57{
58	int error = 0;
59
60	while (uio->uio_resid > 0 && error == 0)
61		error = uiomove(zbuf, MIN(uio->uio_resid, PAGE_SIZE), uio);
62
63	return (error);
64}
65
66/* ARGSUSED */
67static int
68full_write(struct cdev *dev __unused, struct uio *uio __unused,
69    int flags __unused)
70{
71
72	return (ENOSPC);
73}
74
75/* ARGSUSED */
76int
77lindev_modevent_full(module_t mod __unused, int type, void *data __unused)
78{
79
80	switch(type) {
81	case MOD_LOAD:
82		zbuf = (void *)malloc(PAGE_SIZE, M_TEMP, M_WAITOK | M_ZERO);
83		full_dev = make_dev(&full_cdevsw, 0, UID_ROOT, GID_WHEEL,
84		    0666, "full");
85		if (bootverbose)
86			printf("full: <full device>\n");
87		break;
88
89	case MOD_UNLOAD:
90		destroy_dev(full_dev);
91		free(zbuf, M_TEMP);
92		break;
93
94	case MOD_SHUTDOWN:
95		break;
96
97	default:
98		return (EOPNOTSUPP);
99	}
100
101	return (0);
102}
103
104