xref: /netbsd-src/sys/dev/dkwedge/dkwedge_mbr.c (revision 96230fab84e26a6435963032070e916a951a8b2e)
1 /*	$NetBSD: dkwedge_mbr.c,v 1.6 2008/04/28 20:23:48 martin 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 1.6 2008/04/28 20:23:48 martin 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/malloc.h>
46 
47 #include <sys/bootblock.h>
48 
49 typedef struct mbr_args {
50 	struct disk	*pdk;
51 	struct vnode	*vp;
52 	void		*buf;
53 	int		error;
54 	int		mbr_count;
55 } mbr_args_t;
56 
57 static const char *
58 mbr_ptype_to_str(uint8_t ptype)
59 {
60 	const char *str;
61 
62 	switch (ptype) {
63 	case MBR_PTYPE_FAT12:	str = DKW_PTYPE_FAT;		break;
64 	case MBR_PTYPE_FAT16S:	str = DKW_PTYPE_FAT;		break;
65 	case MBR_PTYPE_FAT16B:	str = DKW_PTYPE_FAT;		break;
66 	case MBR_PTYPE_NTFS:	str = DKW_PTYPE_NTFS;		break;
67 	case MBR_PTYPE_FAT32:	str = DKW_PTYPE_FAT;		break;
68 	case MBR_PTYPE_FAT32L:	str = DKW_PTYPE_FAT;		break;
69 	case MBR_PTYPE_FAT16L:	str = DKW_PTYPE_FAT;		break;
70 	case MBR_PTYPE_LNXSWAP:	str = DKW_PTYPE_SWAP;		break;
71 	case MBR_PTYPE_LNXEXT2:	str = DKW_PTYPE_EXT2FS;		break;
72 	case MBR_PTYPE_APPLE_UFS:str = DKW_PTYPE_APPLEUFS;	break;
73 	case MBR_PTYPE_EFI:	str = DKW_PTYPE_FAT;		break;
74 	default:		str = NULL;			break;
75 	}
76 
77 	return (str);
78 }
79 
80 static void
81 getparts(mbr_args_t *a, uint32_t off, uint32_t extoff)
82 {
83 	struct dkwedge_info dkw;
84 	struct mbr_partition *dp;
85 	struct mbr_sector *mbr;
86 	const char *ptype;
87 	int i, error;
88 
89 	error = dkwedge_read(a->pdk, a->vp, off, a->buf, DEV_BSIZE);
90 	if (error) {
91 		aprint_error("%s: unable to read MBR @ %u, "
92 		    "error = %d\n", a->pdk->dk_name, off, a->error);
93 		a->error = error;
94 		return;
95 	}
96 
97 	mbr = a->buf;
98 	if (mbr->mbr_magic != htole16(MBR_MAGIC))
99 		return;
100 
101 	dp = mbr->mbr_parts;
102 
103 	for (i = 0; i < MBR_PART_COUNT; i++) {
104 		/* Extended partitions are handled below. */
105 		if (dp[i].mbrp_type == 0 ||
106 		    MBR_IS_EXTENDED(dp[i].mbrp_type))
107 		    	continue;
108 
109 		if ((ptype = mbr_ptype_to_str(dp[i].mbrp_type)) == NULL) {
110 			/*
111 			 * XXX Should probably just add these...
112 			 * XXX maybe just have an empty ptype?
113 			 */
114 			aprint_verbose("%s: skipping partition %d, "
115 			    "type 0x%02x\n", a->pdk->dk_name, i,
116 			    dp[i].mbrp_type);
117 			continue;
118 		}
119 		strcpy(dkw.dkw_ptype, ptype);
120 
121 		strcpy(dkw.dkw_parent, a->pdk->dk_name);
122 		dkw.dkw_offset = le32toh(dp[i].mbrp_start);
123 		dkw.dkw_size = le32toh(dp[i].mbrp_size);
124 
125 		/*
126 		 * These get historical disk naming style
127 		 * wedge names.  We start at 'e', and reserve
128 		 * 4 slots for each MBR we parse.
129 		 *
130 		 * XXX For FAT, we should extract the FAT volume
131 		 * XXX name.
132 		 */
133 		snprintf(dkw.dkw_wname, sizeof(dkw.dkw_wname),
134 		    "%s%c", a->pdk->dk_name,
135 		    'e' + (a->mbr_count * MBR_PART_COUNT) + i);
136 
137 		error = dkwedge_add(&dkw);
138 		if (error == EEXIST)
139 			aprint_error("%s: wedge named '%s' already "
140 			    "exists, manual intervention required\n",
141 			    a->pdk->dk_name, dkw.dkw_wname);
142 		else if (error)
143 			aprint_error("%s: error %d adding partition "
144 			    "%d type 0x%02x\n", a->pdk->dk_name, error,
145 			    (a->mbr_count * MBR_PART_COUNT) + i,
146 			    dp[i].mbrp_type);
147 	}
148 
149 	/* We've parsed one MBR. */
150 	a->mbr_count++;
151 
152 	/* Recursively scan extended partitions. */
153 	for (i = 0; i < MBR_PART_COUNT; i++) {
154 		uint32_t poff;
155 
156 		if (MBR_IS_EXTENDED(dp[i].mbrp_type)) {
157 			poff = le32toh(dp[i].mbrp_start) + extoff;
158 			getparts(a, poff, extoff ? extoff : poff);
159 		}
160 	}
161 }
162 
163 static int
164 dkwedge_discover_mbr(struct disk *pdk, struct vnode *vp)
165 {
166 	mbr_args_t a;
167 
168 	a.pdk = pdk;
169 	a.vp = vp;
170 	a.buf = malloc(DEV_BSIZE, M_DEVBUF, M_WAITOK);
171 	a.error = 0;
172 	a.mbr_count = 0;
173 
174 	getparts(&a, MBR_BBSECTOR, 0);
175 	if (a.mbr_count != 0)
176 		a.error = 0;		/* found it, wedges installed */
177 	else if (a.error == 0)
178 		a.error = ESRCH;	/* no MBRs found */
179 
180 	free(a.buf, M_DEVBUF);
181 	return (a.error);
182 }
183 
184 DKWEDGE_DISCOVERY_METHOD_DECL(MBR, 10, dkwedge_discover_mbr);
185