xref: /netbsd-src/sys/dev/dkwedge/dkwedge_bsdlabel.c (revision bdc22b2e01993381dcefeff2bc9b56ca75a4235c)
1 /*	$NetBSD: dkwedge_bsdlabel.c,v 1.23 2014/11/04 07:45:45 mlelstv 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  * Adapted from kern/subr_disk_mbr.c:
34  *
35  * Copyright (c) 1982, 1986, 1988 Regents of the University of California.
36  * All rights reserved.
37  *
38  * Redistribution and use in source and binary forms, with or without
39  * modification, are permitted provided that the following conditions
40  * are met:
41  * 1. Redistributions of source code must retain the above copyright
42  *    notice, this list of conditions and the following disclaimer.
43  * 2. Redistributions in binary form must reproduce the above copyright
44  *    notice, this list of conditions and the following disclaimer in the
45  *    documentation and/or other materials provided with the distribution.
46  * 3. Neither the name of the University nor the names of its contributors
47  *    may be used to endorse or promote products derived from this software
48  *    without specific prior written permission.
49  *
50  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
51  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
52  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
53  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
54  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
55  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
56  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
57  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
58  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
59  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
60  * SUCH DAMAGE.
61  *
62  *	@(#)ufs_disksubr.c      7.16 (Berkeley) 5/4/91
63  */
64 
65 /*
66  * 4.4BSD disklabel support for disk wedges
67  *
68  * Here is the basic search algorithm in use here:
69  *
70  * For historical reasons, we scan for x86-style MBR partitions looking
71  * for a MBR_PTYPE_NETBSD (or MBR_PTYPE_386BSD) partition.  The first
72  * 4.4BSD disklabel found in the 2nd sector of such a partition is used.
73  * We assume that the 4.4BSD disklabel describes all partitions on the
74  * disk; we do not use any partition information from the MBR partition
75  * table.
76  *
77  * If that fails, then we fall back on a table of known locations for
78  * various platforms.
79  */
80 
81 #include <sys/cdefs.h>
82 __KERNEL_RCSID(0, "$NetBSD: dkwedge_bsdlabel.c,v 1.23 2014/11/04 07:45:45 mlelstv Exp $");
83 
84 #include <sys/param.h>
85 #ifdef _KERNEL
86 #include <sys/systm.h>
87 #endif
88 #include <sys/proc.h>
89 #include <sys/errno.h>
90 #include <sys/disk.h>
91 #include <sys/vnode.h>
92 #include <sys/malloc.h>
93 
94 #include <sys/bootblock.h>
95 #include <sys/disklabel.h>
96 
97 #define	BSD44_MBR_LABELSECTOR	1
98 
99 #define	DISKLABEL_SIZE(x)						\
100 	(offsetof(struct disklabel, d_partitions) +			\
101 	 (sizeof(struct partition) * (x)))
102 
103 /*
104  * Note the smallest MAXPARTITIONS was 8, so we allow a disklabel
105  * that size to be locted at the end of the sector.
106  */
107 #define	DISKLABEL_MINSIZE	DISKLABEL_SIZE(8)
108 
109 /*
110  * Table of known platform-specific disklabel locations.
111  */
112 static const struct disklabel_location {
113 	daddr_t		label_sector;	/* sector containing label */
114 	size_t		label_offset;	/* byte offset of label in sector */
115 } disklabel_locations[] = {
116 	{ 0,	0 },	/* mvme68k, next68k */
117 	{ 0,	64 },	/* algor, alpha, amiga, amigappc, evbmips, evbppc,
118 			   luna68k, mac68k, macppc, news68k, newsmips,
119 			   pc532, pdp11, pmax, vax, x68k */
120 	{ 0,	128 },	/* sparc, sun68k */
121 	{ 1,	0 },	/* amd64, arc, arm, bebox, cobalt, evbppc, hppa,
122 			   hpcarm, hpcmips, i386, ibmnws, mipsco, mvmeppc,
123 			   ofppc, playstation2, pmppc, prep, sandpoint,
124 			   sbmips, sgimips, sh3 */
125 	/* XXX atari is weird */
126 	{ 2,	0 },	/* cesfic, hp300 */
127 
128 	{ -1,	0 },
129 };
130 
131 #define	SCAN_CONTINUE	0
132 #define	SCAN_FOUND	1
133 #define	SCAN_ERROR	2
134 
135 typedef struct mbr_args {
136 	struct disk	*pdk;
137 	struct vnode	*vp;
138 	void		*buf;
139 	int		error;
140 	uint32_t	secsize;
141 } mbr_args_t;
142 
143 static const char *
144 bsdlabel_fstype_to_str(uint8_t fstype)
145 {
146 	const char *str;
147 
148 	/*
149 	 * For each type known to FSTYPE_DEFN (from <sys/disklabel.h>),
150 	 * a suitable case branch will convert the type number to a string.
151 	 */
152 	switch (fstype) {
153 #define FSTYPE_TO_STR_CASE(tag, number, name, fsck, mount) \
154 	case __CONCAT(FS_,tag):	str = __CONCAT(DKW_PTYPE_,tag);			break;
155 	FSTYPE_DEFN(FSTYPE_TO_STR_CASE)
156 #undef FSTYPE_TO_STR_CASE
157 	default:		str = NULL;			break;
158 	}
159 
160 	return (str);
161 }
162 
163 static void
164 swap_disklabel(struct disklabel *lp)
165 {
166 	int i;
167 
168 #define	SWAP16(x)	lp->x = bswap16(lp->x)
169 #define	SWAP32(x)	lp->x = bswap32(lp->x)
170 
171 	SWAP32(d_magic);
172 	SWAP16(d_type);
173 	SWAP16(d_subtype);
174 	SWAP32(d_secsize);
175 	SWAP32(d_nsectors);
176 	SWAP32(d_ntracks);
177 	SWAP32(d_ncylinders);
178 	SWAP32(d_secpercyl);
179 	SWAP32(d_secperunit);
180 	SWAP16(d_sparespertrack);
181 	SWAP16(d_sparespercyl);
182 	SWAP32(d_acylinders);
183 	SWAP16(d_rpm);
184 	SWAP16(d_interleave);
185 	SWAP16(d_trackskew);
186 	SWAP16(d_cylskew);
187 	SWAP32(d_headswitch);
188 	SWAP32(d_trkseek);
189 	SWAP32(d_flags);
190 
191 	for (i = 0; i < NDDATA; i++)
192 		SWAP32(d_drivedata[i]);
193 	for (i = 0; i < NSPARE; i++)
194 		SWAP32(d_spare[i]);
195 
196 	SWAP32(d_magic2);
197 	SWAP16(d_checksum);
198 	SWAP16(d_npartitions);
199 	SWAP32(d_bbsize);
200 	SWAP32(d_sbsize);
201 
202 	for (i = 0; i < lp->d_npartitions; i++) {
203 		SWAP32(d_partitions[i].p_size);
204 		SWAP32(d_partitions[i].p_offset);
205 		SWAP32(d_partitions[i].p_fsize);
206 		SWAP16(d_partitions[i].p_cpg);
207 	}
208 
209 #undef SWAP16
210 #undef SWAP32
211 }
212 
213 /*
214  * Add wedges for a valid NetBSD disklabel.
215  */
216 static void
217 addwedges(const mbr_args_t *a, const struct disklabel *lp)
218 {
219 	int error, i;
220 
221 	for (i = 0; i < lp->d_npartitions; i++) {
222 		struct dkwedge_info dkw;
223 		const struct partition *p;
224 		const char *ptype;
225 
226 		p = &lp->d_partitions[i];
227 
228 		if (p->p_fstype == FS_UNUSED)
229 			continue;
230 		ptype = bsdlabel_fstype_to_str(p->p_fstype);
231 		if (ptype == NULL)
232 			snprintf(dkw.dkw_ptype, sizeof(dkw.dkw_ptype),
233 			    "unknown#%u", p->p_fstype);
234 		else
235 			strlcpy(dkw.dkw_ptype, ptype, sizeof(dkw.dkw_ptype));
236 
237 		strlcpy(dkw.dkw_parent, a->pdk->dk_name,
238 		    sizeof(dkw.dkw_parent));
239 		dkw.dkw_offset = p->p_offset;
240 		dkw.dkw_size = p->p_size;
241 
242 		/*
243 		 * If the label defines a name, append the partition
244 		 * letter and use it as the wedge name.
245 		 * Otherwise use historical disk naming style
246 		 * wedge names.
247 		 */
248 		if (lp->d_packname[0] &&
249 		    strcmp(lp->d_packname,"fictitious") != 0) {
250 			snprintf((char *)&dkw.dkw_wname, sizeof(dkw.dkw_wname),
251 		    		"%.*s/%c", (int)sizeof(dkw.dkw_wname)-3,
252 				lp->d_packname, 'a' + i);
253 		} else {
254 			snprintf((char *)&dkw.dkw_wname, sizeof(dkw.dkw_wname),
255 			    "%s%c", a->pdk->dk_name, 'a' + i);
256 		}
257 
258 		error = dkwedge_add(&dkw);
259 		if (error == EEXIST)
260 			aprint_error("%s: wedge named '%s' already "
261 			    "exists, manual intervention required\n",
262 			    a->pdk->dk_name, dkw.dkw_wname);
263 		else if (error)
264 			aprint_error("%s: error %d adding partition "
265 			    "%d type %d\n", a->pdk->dk_name, error,
266 			    i, p->p_fstype);
267 	}
268 }
269 
270 static int
271 validate_label(mbr_args_t *a, daddr_t label_sector, size_t label_offset)
272 {
273 	struct disklabel *lp;
274 	void *lp_lim;
275 	int error, swapped;
276 	uint16_t npartitions;
277 
278 	error = dkwedge_read(a->pdk, a->vp, label_sector, a->buf, a->secsize);
279 	if (error) {
280 		aprint_error("%s: unable to read BSD disklabel @ %" PRId64
281 		    ", error = %d\n", a->pdk->dk_name, label_sector, error);
282 		a->error = error;
283 		return (SCAN_ERROR);
284 	}
285 
286 	/*
287 	 * We ignore label_offset; this seems to have not been used
288 	 * consistently in the old code, requiring us to do the search
289 	 * in the sector.
290 	 */
291 	lp = a->buf;
292 	lp_lim = (char *)a->buf + a->secsize - DISKLABEL_MINSIZE;
293 	for (;; lp = (void *)((char *)lp + sizeof(uint32_t))) {
294 		if ((char *)lp > (char *)lp_lim)
295 			return (SCAN_CONTINUE);
296 		label_offset = (size_t)((char *)lp - (char *)a->buf);
297 		if (lp->d_magic != DISKMAGIC || lp->d_magic2 != DISKMAGIC) {
298 			if (lp->d_magic != bswap32(DISKMAGIC) ||
299 			    lp->d_magic2 != bswap32(DISKMAGIC))
300 				continue;
301 			/* Label is in the other byte order. */
302 			swapped = 1;
303 		} else
304 			swapped = 0;
305 
306 		npartitions = (swapped) ? bswap16(lp->d_npartitions)
307 					: lp->d_npartitions;
308 
309 		/* Validate label length. */
310 		if ((char *)lp + DISKLABEL_SIZE(npartitions) >
311 		    (char *)a->buf + a->secsize) {
312 			aprint_error("%s: BSD disklabel @ "
313 			    "%" PRId64 "+%zd has bogus partition count (%u)\n",
314 			    a->pdk->dk_name, label_sector, label_offset,
315 			    npartitions);
316 			continue;
317 		}
318 
319 		/*
320 		 * We have validated the partition count.  Checksum it.
321 		 * Note that we purposefully checksum before swapping
322 		 * the byte order.
323 		 */
324 		if (dkcksum_sized(lp, npartitions) != 0) {
325 			aprint_error("%s: BSD disklabel @ %" PRId64
326 			    "+%zd has bad checksum\n", a->pdk->dk_name,
327 			    label_sector, label_offset);
328 			continue;
329 		}
330 		/* Put the disklabel in the right order. */
331 		if (swapped)
332 			swap_disklabel(lp);
333 		addwedges(a, lp);
334 		return (SCAN_FOUND);
335 	}
336 }
337 
338 static int
339 scan_mbr(mbr_args_t *a, int (*actn)(mbr_args_t *, struct mbr_partition *,
340 				    int, u_int))
341 {
342 	struct mbr_partition ptns[MBR_PART_COUNT];
343 	struct mbr_partition *dp;
344 	struct mbr_sector *mbr;
345 	u_int ext_base, this_ext, next_ext;
346 	int i, rval;
347 #ifdef COMPAT_386BSD_MBRPART
348 	int dp_386bsd = -1;
349 #endif
350 
351 	ext_base = 0;
352 	this_ext = 0;
353 	for (;;) {
354 		a->error = dkwedge_read(a->pdk, a->vp, this_ext, a->buf,
355 					a->secsize);
356 		if (a->error) {
357 			aprint_error("%s: unable to read MBR @ %u, "
358 			    "error = %d\n", a->pdk->dk_name, this_ext,
359 			    a->error);
360 			return (SCAN_ERROR);
361 		}
362 
363 		mbr = a->buf;
364 		if (mbr->mbr_magic != htole16(MBR_MAGIC))
365 			return (SCAN_CONTINUE);
366 
367 		/* Copy data out of buffer so action can use the buffer. */
368 		memcpy(ptns, &mbr->mbr_parts, sizeof(ptns));
369 
370 		/* Looks for NetBSD partition. */
371 		next_ext = 0;
372 		dp = ptns;
373 		for (i = 0; i < MBR_PART_COUNT; i++, dp++) {
374 			if (dp->mbrp_type == 0)
375 				continue;
376 			if (MBR_IS_EXTENDED(dp->mbrp_type)) {
377 				next_ext = le32toh(dp->mbrp_start);
378 				continue;
379 			}
380 #ifdef COMPAT_386BSD_MBRPART
381 			if (dp->mbrp_type == MBR_PTYPE_386BSD) {
382 				/*
383 				 * If more than one matches, take last,
384 				 * as NetBSD install tool does.
385 				 */
386 				if (this_ext == 0)
387 					dp_386bsd = i;
388 				continue;
389 			}
390 #endif
391 			rval = (*actn)(a, dp, i, this_ext);
392 			if (rval != SCAN_CONTINUE)
393 				return (rval);
394 		}
395 		if (next_ext == 0)
396 			break;
397 		if (ext_base == 0) {
398 			ext_base = next_ext;
399 			next_ext = 0;
400 		}
401 		next_ext += ext_base;
402 		if (next_ext <= this_ext)
403 			break;
404 		this_ext = next_ext;
405 	}
406 #ifdef COMPAT_386BSD_MBRPART
407 	if (this_ext == 0 && dp_386bsd != -1)
408 		return ((*actn)(a, &ptns[dp_386bsd], dp_386bsd, 0));
409 #endif
410 	return (SCAN_CONTINUE);
411 }
412 
413 static int
414 look_netbsd_part(mbr_args_t *a, struct mbr_partition *dp, int slot,
415     u_int ext_base)
416 {
417 	int ptn_base = ext_base + le32toh(dp->mbrp_start);
418 	int rval;
419 
420 	if (
421 #ifdef COMPAT_386BSD_MBRPART
422 	    dp->mbrp_type == MBR_PTYPE_386BSD ||
423 #endif
424 	    dp->mbrp_type == MBR_PTYPE_NETBSD) {
425 		rval = validate_label(a, ptn_base + BSD44_MBR_LABELSECTOR, 0);
426 
427 		/* If we got a NetBSD label, look no further. */
428 		if (rval == SCAN_FOUND)
429 			return (rval);
430 	}
431 
432 	return (SCAN_CONTINUE);
433 }
434 
435 #ifdef _KERNEL
436 #define	DKW_MALLOC(SZ)	malloc((SZ), M_DEVBUF, M_WAITOK)
437 #define	DKW_FREE(PTR)	free((PTR), M_DEVBUF)
438 #else
439 #define	DKW_MALLOC(SZ)	malloc((SZ))
440 #define	DKW_FREE(PTR)	free((PTR))
441 #endif
442 
443 static int
444 dkwedge_discover_bsdlabel(struct disk *pdk, struct vnode *vp)
445 {
446 	mbr_args_t a;
447 	const struct disklabel_location *dl;
448 	int rval;
449 
450 	a.pdk = pdk;
451 	a.secsize = DEV_BSIZE << pdk->dk_blkshift;
452 	a.vp = vp;
453 	a.buf = DKW_MALLOC(a.secsize);
454 	a.error = 0;
455 
456 	/* MBR search. */
457 	rval = scan_mbr(&a, look_netbsd_part);
458 	if (rval != SCAN_CONTINUE) {
459 		if (rval == SCAN_FOUND)
460 			a.error = 0;	/* found it, wedges installed */
461 		goto out;
462 	}
463 
464 	/* Known location search. */
465 	for (dl = disklabel_locations; dl->label_sector != -1; dl++) {
466 		rval = validate_label(&a, dl->label_sector, dl->label_offset);
467 		if (rval != SCAN_CONTINUE) {
468 			if (rval == SCAN_FOUND)
469 				a.error = 0;	/* found it, wedges installed */
470 			goto out;
471 		}
472 	}
473 
474 	/* No NetBSD disklabel found. */
475 	a.error = ESRCH;
476  out:
477 	DKW_FREE(a.buf);
478 	return (a.error);
479 }
480 
481 #ifdef _KERNEL
482 DKWEDGE_DISCOVERY_METHOD_DECL(BSD44, 5, dkwedge_discover_bsdlabel);
483 #endif
484