1/*-
2 * Copyright (c) 2005 Stanislav Sedov
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/systm.h>
32#include <sys/kernel.h>
33#include <sys/malloc.h>
34
35#include <geom/geom.h>
36#include <geom/label/g_label.h>
37
38#define EXT2FS_SB_OFFSET	1024
39#define EXT2_SUPER_MAGIC	0xef53
40#define EXT2_DYNAMIC_REV	1
41
42typedef struct e2sb {
43	uint8_t		fake1[56];
44	uint16_t	s_magic;
45	uint8_t		fake2[18];
46	uint32_t	s_rev_level;
47	uint8_t		fake3[40];
48	char		s_volume_name[16];
49} e2sb_t;
50
51static void
52g_label_ext2fs_taste(struct g_consumer *cp, char *label, size_t size)
53{
54	struct g_provider *pp;
55	e2sb_t *fs;
56	char *s_volume_name;
57
58	g_topology_assert_not();
59	pp = cp->provider;
60	label[0] = '\0';
61
62	if ((EXT2FS_SB_OFFSET % pp->sectorsize) != 0)
63		return;
64
65	fs = (e2sb_t *)g_read_data(cp, EXT2FS_SB_OFFSET, pp->sectorsize, NULL);
66	if (fs == NULL)
67		return;
68
69	/* Check for magic and versio n*/
70	if (fs->s_magic == EXT2_SUPER_MAGIC &&
71	    fs->s_rev_level == EXT2_DYNAMIC_REV) {
72		G_LABEL_DEBUG(1, "ext2fs file system detected on %s.",
73		    pp->name);
74	} else {
75		goto exit_free;
76	}
77
78	s_volume_name = fs->s_volume_name;
79	/* Terminate label */
80	s_volume_name[sizeof(fs->s_volume_name) - 1] = '\0';
81
82	if (s_volume_name[0] == '/')
83		s_volume_name += 1;
84
85	/* Check for volume label */
86	if (s_volume_name[0] == '\0')
87		goto exit_free;
88
89	strlcpy(label, s_volume_name, size);
90
91exit_free:
92	g_free(fs);
93}
94
95struct g_label_desc g_label_ext2fs = {
96	.ld_taste = g_label_ext2fs_taste,
97	.ld_dir = "ext2fs",
98	.ld_enabled = 1
99};
100
101G_LABEL_INIT(ext2fs, g_label_ext2fs, "Create device nodes for EXT2FS volumes");
102