1 /* $NetBSD: dkwedge_mbr.c,v 1.13 2024/02/26 21:55:05 charlotte Exp $ */
2
3 /*-
4 * Copyright (c) 2004 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jason R. Thorpe.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 /*
33 * Master Boot Record partition table support for disk wedges
34 */
35
36 #include <sys/cdefs.h>
37 __KERNEL_RCSID(0, "$NetBSD: dkwedge_mbr.c,v 1.13 2024/02/26 21:55:05 charlotte Exp $");
38
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/proc.h>
42 #include <sys/errno.h>
43 #include <sys/disk.h>
44 #include <sys/vnode.h>
45 #include <sys/buf.h>
46
47 #include <sys/bootblock.h>
48 #include <sys/disklabel.h>
49
50 typedef struct mbr_args {
51 struct disk *pdk;
52 struct vnode *vp;
53 struct buf *bp;
54 int error;
55 uint32_t secsize;
56 int mbr_count;
57 } mbr_args_t;
58
59 static const char *
mbr_ptype_to_str(uint8_t ptype)60 mbr_ptype_to_str(uint8_t ptype)
61 {
62 const char *str;
63
64 switch (ptype) {
65 case MBR_PTYPE_FAT12: str = DKW_PTYPE_FAT; break;
66 case MBR_PTYPE_FAT16S: str = DKW_PTYPE_FAT; break;
67 case MBR_PTYPE_FAT16B: str = DKW_PTYPE_FAT; break;
68 case MBR_PTYPE_NTFS: str = DKW_PTYPE_NTFS; break;
69 case MBR_PTYPE_FAT32: str = DKW_PTYPE_FAT; break;
70 case MBR_PTYPE_FAT32L: str = DKW_PTYPE_FAT; break;
71 case MBR_PTYPE_FAT16L: str = DKW_PTYPE_FAT; break;
72 case MBR_PTYPE_LNXSWAP: str = DKW_PTYPE_SWAP; break;
73 case MBR_PTYPE_LNXEXT2: str = DKW_PTYPE_EXT2FS; break;
74 case MBR_PTYPE_APPLE_UFS:str = DKW_PTYPE_APPLEUFS; break;
75 case MBR_PTYPE_EFI: str = DKW_PTYPE_FAT; break;
76 default: str = NULL; break;
77 }
78
79 return (str);
80 }
81
82 static void
getparts(mbr_args_t * a,uint32_t off,uint32_t extoff)83 getparts(mbr_args_t *a, uint32_t off, uint32_t extoff)
84 {
85 struct dkwedge_info dkw;
86 struct mbr_partition *dp;
87 struct mbr_sector *mbr;
88 const char *ptype;
89 int i, error;
90
91 error = dkwedge_read(a->pdk, a->vp, off, a->bp->b_data, a->secsize);
92 if (error) {
93 a->error = error;
94 aprint_error("%s: unable to read MBR @ %u/%u, "
95 "error = %d\n", a->pdk->dk_name, off, a->secsize, a->error);
96 return;
97 }
98
99 mbr = a->bp->b_data;
100 if (mbr->mbr_magic != htole16(MBR_MAGIC))
101 return;
102
103 dp = mbr->mbr_parts;
104
105 for (i = 0; i < MBR_PART_COUNT; i++) {
106 switch (dp[i].mbrp_type) {
107 case 0: /* empty */
108 case MBR_PTYPE_PMBR: /* Handled by GPT */
109 continue;
110 default:
111 /* Extended partitions are handled below. */
112 if (MBR_IS_EXTENDED(dp[i].mbrp_type))
113 continue;
114 break;
115 }
116
117 memset(&dkw, 0, sizeof(dkw));
118
119 if ((ptype = mbr_ptype_to_str(dp[i].mbrp_type)) == NULL) {
120 /*
121 * XXX Should probably just add these...
122 * XXX maybe just have an empty ptype?
123 */
124 aprint_verbose("%s: skipping partition %d, "
125 "type 0x%02x\n", a->pdk->dk_name, i,
126 dp[i].mbrp_type);
127 continue;
128 }
129 strlcpy(dkw.dkw_ptype, ptype, sizeof(dkw.dkw_ptype));
130
131 strlcpy(dkw.dkw_parent, a->pdk->dk_name, sizeof(dkw.dkw_parent));
132 dkw.dkw_offset = le32toh(dp[i].mbrp_start);
133 dkw.dkw_size = le32toh(dp[i].mbrp_size);
134
135 /*
136 * These get historical disk naming style
137 * wedge names. We start at 'e', and reserve
138 * 4 slots for each MBR we parse.
139 *
140 * XXX For FAT, we should extract the FAT volume
141 * XXX name.
142 */
143 snprintf(dkw.dkw_wname, sizeof(dkw.dkw_wname),
144 "%s%c", a->pdk->dk_name,
145 'e' + (a->mbr_count * MBR_PART_COUNT) + i);
146
147 error = dkwedge_add(&dkw);
148 if (error == EEXIST)
149 aprint_error("%s: wedge named '%s' already "
150 "exists, manual intervention required\n",
151 a->pdk->dk_name, dkw.dkw_wname);
152 else if (error)
153 aprint_error("%s: error %d adding partition "
154 "%d type 0x%02x\n", a->pdk->dk_name, error,
155 (a->mbr_count * MBR_PART_COUNT) + i,
156 dp[i].mbrp_type);
157 }
158
159 /* We've parsed one MBR. */
160 a->mbr_count++;
161
162 /* Recursively scan extended partitions. */
163 for (i = 0; i < MBR_PART_COUNT; i++) {
164 uint32_t poff;
165
166 if (MBR_IS_EXTENDED(dp[i].mbrp_type)) {
167 poff = le32toh(dp[i].mbrp_start) + extoff;
168 getparts(a, poff, extoff ? extoff : poff);
169 }
170 }
171 }
172
173 static int
dkwedge_discover_mbr(struct disk * pdk,struct vnode * vp)174 dkwedge_discover_mbr(struct disk *pdk, struct vnode *vp)
175 {
176 mbr_args_t a;
177
178 memset(&a, 0, sizeof(a));
179 a.pdk = pdk;
180 a.secsize = DEV_BSIZE << pdk->dk_blkshift;
181 a.vp = vp;
182 a.bp = geteblk(a.secsize);
183 a.error = 0;
184 a.mbr_count = 0;
185
186 getparts(&a, MBR_BBSECTOR, 0);
187 if (a.mbr_count != 0)
188 a.error = 0; /* found it, wedges installed */
189 else if (a.error == 0)
190 a.error = ESRCH; /* no MBRs found */
191
192 brelse(a.bp, 0);
193 return (a.error);
194 }
195
196 DKWEDGE_DISCOVERY_METHOD_DECL(MBR, 10, dkwedge_discover_mbr);
197