1 /*
2  * BSD/OSF partition parsing code
3  *
4  * Copyright (C) 2009 Karel Zak <kzak@redhat.com>
5  *
6  * This file may be redistributed under the terms of the
7  * GNU Lesser General Public License.
8  *
9  * Inspired by fdisk, partx, Linux kernel, libparted and openbsd header files.
10  */
11 #include <stdio.h>
12 #include <string.h>
13 #include <stdlib.h>
14 #include <stdint.h>
15 
16 #include "partitions.h"
17 #include "pt-bsd.h"
18 
19 /* Returns 'blkid_idmag' in 512-sectors */
20 #define BLKID_MAG_SECTOR(_mag)  (((_mag)->kboff / 2)  + ((_mag)->sboff >> 9))
21 
22 /* Returns 'blkid_idmag' in bytes */
23 #define BLKID_MAG_OFFSET(_mag)  ((_mag)->kboff << 10) + ((_mag)->sboff)
24 
25 /* Returns 'blkid_idmag' offset in bytes within the last sector */
26 #define BLKID_MAG_LASTOFFSET(_mag) \
27 		 (BLKID_MAG_OFFSET(_mag) - (BLKID_MAG_SECTOR(_mag) << 9))
28 
probe_bsd_pt(blkid_probe pr,const struct blkid_idmag * mag)29 static int probe_bsd_pt(blkid_probe pr, const struct blkid_idmag *mag)
30 {
31 	struct bsd_disklabel *l;
32 	struct bsd_partition *p;
33 	const char *name = "bsd" ;
34 	blkid_parttable tab = NULL;
35 	blkid_partition parent;
36 	blkid_partlist ls;
37 	int i, nparts = BSD_MAXPARTITIONS;
38 	unsigned char *data;
39 	int rc = BLKID_PROBE_NONE;
40 	uint32_t abs_offset = 0;
41 
42 	if (blkid_partitions_need_typeonly(pr))
43 		/* caller does not ask for details about partitions */
44 		return rc;
45 
46 	data = blkid_probe_get_sector(pr, BLKID_MAG_SECTOR(mag));
47 	if (!data) {
48 		if (errno)
49 			rc = -errno;
50 		goto nothing;
51 	}
52 
53 	l = (struct bsd_disklabel *) data + BLKID_MAG_LASTOFFSET(mag);
54 
55 	ls = blkid_probe_get_partlist(pr);
56 	if (!ls)
57 		goto nothing;
58 
59 	/* try to determine the real type of BSD system according to
60 	 * (parental) primary partition */
61 	parent = blkid_partlist_get_parent(ls);
62 	if (parent) {
63 		switch(blkid_partition_get_type(parent)) {
64 		case MBR_FREEBSD_PARTITION:
65 			name = "freebsd";
66 			abs_offset = blkid_partition_get_start(parent);
67 			break;
68 		case MBR_NETBSD_PARTITION:
69 			name = "netbsd";
70 			break;
71 		case MBR_OPENBSD_PARTITION:
72 			name = "openbsd";
73 			break;
74 		default:
75 			DBG(LOWPROBE, ul_debug(
76 				"WARNING: BSD label detected on unknown (0x%x) "
77 				"primary partition",
78 				blkid_partition_get_type(parent)));
79 			break;
80 		}
81 	}
82 
83 	tab = blkid_partlist_new_parttable(ls, name, BLKID_MAG_OFFSET(mag));
84 	if (!tab) {
85 		rc = -ENOMEM;
86 		goto nothing;
87 	}
88 
89 	if (le16_to_cpu(l->d_npartitions) < BSD_MAXPARTITIONS)
90 		nparts = le16_to_cpu(l->d_npartitions);
91 
92 	else if (le16_to_cpu(l->d_npartitions) > BSD_MAXPARTITIONS)
93 		DBG(LOWPROBE, ul_debug(
94 			"WARNING: ignore %d more BSD partitions",
95 			le16_to_cpu(l->d_npartitions) - BSD_MAXPARTITIONS));
96 
97 	for (i = 0, p = l->d_partitions; i < nparts; i++, p++) {
98 		blkid_partition par;
99 		uint32_t start, size;
100 
101 		if (p->p_fstype == BSD_FS_UNUSED)
102 			continue;
103 
104 		start = le32_to_cpu(p->p_offset);
105 		size = le32_to_cpu(p->p_size);
106 
107 		/* FreeBSD since version 10 uses relative offsets. We can use
108 		 * 3rd partition (special wholedisk partition) to detect this
109 		 * situation.
110 		 */
111 		if (abs_offset && nparts >= 3
112 		    && le32_to_cpu(l->d_partitions[2].p_offset) == 0)
113 			start += abs_offset;
114 
115 		if (parent && blkid_partition_get_start(parent) == start
116 			   && blkid_partition_get_size(parent) == size) {
117 			DBG(LOWPROBE, ul_debug(
118 				"WARNING: BSD partition (%d) same like parent, "
119 				"ignore", i));
120 			continue;
121 		}
122 		if (parent && !blkid_is_nested_dimension(parent, start, size)) {
123 			DBG(LOWPROBE, ul_debug(
124 				"WARNING: BSD partition (%d) overflow "
125 				"detected, ignore", i));
126 			continue;
127 		}
128 
129 		par = blkid_partlist_add_partition(ls, tab, start, size);
130 		if (!par) {
131 			rc = -ENOMEM;
132 			goto nothing;
133 		}
134 
135 		blkid_partition_set_type(par, p->p_fstype);
136 	}
137 
138 	return BLKID_PROBE_OK;
139 
140 nothing:
141 	return rc;
142 }
143 
144 
145 /*
146  * All BSD variants use the same magic string (little-endian),
147  * and the same disklabel.
148  *
149  * The difference between {Free,Open,...}BSD is in the (parental)
150  * primary partition type.
151  *
152  * See also: http://en.wikipedia.org/wiki/BSD_disklabel
153  *
154  * The location of BSD disk label is architecture specific and in defined by
155  * LABELSECTOR and LABELOFFSET macros in the disklabel.h file. The location
156  * also depends on BSD variant, FreeBSD uses only one location, NetBSD and
157  * OpenBSD are more creative...
158  *
159  * The basic overview:
160  *
161  * arch                    | LABELSECTOR | LABELOFFSET
162  * ------------------------+-------------+------------
163  * amd64 arm hppa hppa64   |             |
164  * i386, macppc, mvmeppc   |      1      |      0
165  * sgi, aviion, sh, socppc |             |
166  * ------------------------+-------------+------------
167  * alpha luna88k mac68k    |      0      |     64
168  * sparc(OpenBSD) vax      |             |
169  * ------------------------+-------------+------------
170  * sparc64 sparc(NetBSD)   |      0      |    128
171  * ------------------------+-------------+------------
172  *
173  * ...and more (see http://fxr.watson.org/fxr/ident?v=NETBSD;i=LABELSECTOR)
174  *
175  */
176 const struct blkid_idinfo bsd_pt_idinfo =
177 {
178 	.name		= "bsd",
179 	.probefunc	= probe_bsd_pt,
180 	.magics		=
181 	{
182 		{ .magic = "\x57\x45\x56\x82", .len = 4, .sboff = 512 },
183 		{ .magic = "\x57\x45\x56\x82", .len = 4, .sboff = 64 },
184 		{ .magic = "\x57\x45\x56\x82", .len = 4, .sboff = 128 },
185 		{ NULL }
186 	}
187 };
188 
189