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
29 static uint16_t bsd_checksum(const struct bsd_disklabel *l)
30 {
31 uint16_t v, csum = 0;
32 const char *end = (const char *) (l + 1);
33
34 for (const char *c = (const char *) l; c < end; c += sizeof(uint16_t)) {
35 memcpy(&v, c, sizeof(v));
36 csum ^= v;
37 }
38 return csum ^ le16_to_cpu(l->d_checksum);
39 }
40
41 static int probe_bsd_pt(blkid_probe pr, const struct blkid_idmag *mag)
42 {
43 struct bsd_disklabel *l;
44 struct bsd_partition *p;
45 const char *name = "bsd" ;
46 blkid_parttable tab = NULL;
47 blkid_partition parent;
48 blkid_partlist ls;
49 int i, nparts = BSD_MAXPARTITIONS;
50 unsigned char *data;
51 int rc = BLKID_PROBE_NONE;
52 uint32_t abs_offset = 0;
53
54 if (blkid_partitions_need_typeonly(pr))
55 /* caller does not ask for details about partitions */
56 return rc;
57
58 data = blkid_probe_get_sector(pr, BLKID_MAG_SECTOR(mag));
59 if (!data) {
60 if (errno)
61 rc = -errno;
62 goto nothing;
63 }
64
65 l = (struct bsd_disklabel *) (data + BLKID_MAG_LASTOFFSET(mag));
66
67 if (!blkid_probe_verify_csum(pr, bsd_checksum(l), le16_to_cpu(l->d_checksum))) {
68 rc = BLKID_PROBE_NONE;
69 goto nothing;
70 }
71
72 ls = blkid_probe_get_partlist(pr);
73 if (!ls)
74 goto nothing;
75
76 /* try to determine the real type of BSD system according to
77 * (parental) primary partition */
78 parent = blkid_partlist_get_parent(ls);
79 if (parent) {
80 switch(blkid_partition_get_type(parent)) {
81 case MBR_FREEBSD_PARTITION:
82 name = "freebsd";
83 abs_offset = blkid_partition_get_start(parent);
84 break;
85 case MBR_NETBSD_PARTITION:
86 name = "netbsd";
87 break;
88 case MBR_OPENBSD_PARTITION:
89 name = "openbsd";
90 break;
91 default:
92 DBG(LOWPROBE, ul_debug(
93 "WARNING: BSD label detected on unknown (0x%x) "
94 "primary partition",
95 blkid_partition_get_type(parent)));
96 break;
97 }
98 }
99
100 tab = blkid_partlist_new_parttable(ls, name, BLKID_MAG_OFFSET(mag));
101 if (!tab) {
102 rc = -ENOMEM;
103 goto nothing;
104 }
105
106 if (le16_to_cpu(l->d_npartitions) < BSD_MAXPARTITIONS)
107 nparts = le16_to_cpu(l->d_npartitions);
108
109 else if (le16_to_cpu(l->d_npartitions) > BSD_MAXPARTITIONS)
110 DBG(LOWPROBE, ul_debug(
111 "WARNING: ignore %d more BSD partitions",
112 le16_to_cpu(l->d_npartitions) - BSD_MAXPARTITIONS));
113
114 for (i = 0, p = l->d_partitions; i < nparts; i++, p++) {
115 blkid_partition par;
116 uint32_t start, size;
117
118 if (p->p_fstype == BSD_FS_UNUSED)
119 continue;
120
121 start = le32_to_cpu(p->p_offset);
122 size = le32_to_cpu(p->p_size);
123
124 /* FreeBSD since version 10 uses relative offsets. We can use
125 * 3rd partition (special wholedisk partition) to detect this
126 * situation.
127 */
128 if (abs_offset && nparts >= 3
129 && le32_to_cpu(l->d_partitions[2].p_offset) == 0)
130 start += abs_offset;
131
132 if (parent && blkid_partition_get_start(parent) == start
133 && blkid_partition_get_size(parent) == size) {
134 DBG(LOWPROBE, ul_debug(
135 "WARNING: BSD partition (%d) same like parent, "
136 "ignore", i));
137 continue;
138 }
139 if (parent && !blkid_is_nested_dimension(parent, start, size)) {
140 DBG(LOWPROBE, ul_debug(
141 "WARNING: BSD partition (%d) overflow "
142 "detected, ignore", i));
143 continue;
144 }
145
146 par = blkid_partlist_add_partition(ls, tab, start, size);
147 if (!par) {
148 rc = -ENOMEM;
149 goto nothing;
150 }
151
152 blkid_partition_set_type(par, p->p_fstype);
153 }
154
155 return BLKID_PROBE_OK;
156
157 nothing:
158 return rc;
159 }
160
161
162 /*
163 * All BSD variants use the same magic string (little-endian),
164 * and the same disklabel.
165 *
166 * The difference between {Free,Open,...}BSD is in the (parental)
167 * primary partition type.
168 *
169 * See also: http://en.wikipedia.org/wiki/BSD_disklabel
170 *
171 * The location of BSD disk label is architecture specific and in defined by
172 * LABELSECTOR and LABELOFFSET macros in the disklabel.h file. The location
173 * also depends on BSD variant, FreeBSD uses only one location, NetBSD and
174 * OpenBSD are more creative...
175 *
176 * The basic overview:
177 *
178 * arch | LABELSECTOR | LABELOFFSET
179 * ------------------------+-------------+------------
180 * amd64 arm hppa hppa64 | |
181 * i386, macppc, mvmeppc | 1 | 0
182 * sgi, aviion, sh, socppc | |
183 * ------------------------+-------------+------------
184 * alpha luna88k mac68k | 0 | 64
185 * sparc(OpenBSD) vax | |
186 * ------------------------+-------------+------------
187 * sparc64 sparc(NetBSD) | 0 | 128
188 * ------------------------+-------------+------------
189 *
190 * ...and more (see http://fxr.watson.org/fxr/ident?v=NETBSD;i=LABELSECTOR)
191 *
192 */
193 const struct blkid_idinfo bsd_pt_idinfo =
194 {
195 .name = "bsd",
196 .probefunc = probe_bsd_pt,
197 .magics =
198 {
199 { .magic = "\x57\x45\x56\x82", .len = 4, .sboff = 512 },
200 { .magic = "\x57\x45\x56\x82", .len = 4, .sboff = 64 },
201 { .magic = "\x57\x45\x56\x82", .len = 4, .sboff = 128 },
202 { NULL }
203 }
204 };
205