xref: /freebsd/sys/geom/part/g_part_gpt.c (revision 35ae9291c2621d66ac66ed4a4996761946ac3e2d)
1 /*-
2  * Copyright (c) 2002, 2005, 2006, 2007 Marcel Moolenaar
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/param.h>
31 #include <sys/bio.h>
32 #include <sys/diskmbr.h>
33 #include <sys/endian.h>
34 #include <sys/gpt.h>
35 #include <sys/kernel.h>
36 #include <sys/kobj.h>
37 #include <sys/limits.h>
38 #include <sys/lock.h>
39 #include <sys/malloc.h>
40 #include <sys/mutex.h>
41 #include <sys/queue.h>
42 #include <sys/sbuf.h>
43 #include <sys/systm.h>
44 #include <sys/uuid.h>
45 #include <geom/geom.h>
46 #include <geom/part/g_part.h>
47 
48 #include "g_part_if.h"
49 
50 CTASSERT(offsetof(struct gpt_hdr, padding) == 92);
51 CTASSERT(sizeof(struct gpt_ent) == 128);
52 
53 #define	EQUUID(a,b)	(memcmp(a, b, sizeof(struct uuid)) == 0)
54 
55 #define	MBRSIZE		512
56 
57 enum gpt_elt {
58 	GPT_ELT_PRIHDR,
59 	GPT_ELT_PRITBL,
60 	GPT_ELT_SECHDR,
61 	GPT_ELT_SECTBL,
62 	GPT_ELT_COUNT
63 };
64 
65 enum gpt_state {
66 	GPT_STATE_UNKNOWN,	/* Not determined. */
67 	GPT_STATE_MISSING,	/* No signature found. */
68 	GPT_STATE_CORRUPT,	/* Checksum mismatch. */
69 	GPT_STATE_INVALID,	/* Nonconformant/invalid. */
70 	GPT_STATE_OK		/* Perfectly fine. */
71 };
72 
73 struct g_part_gpt_table {
74 	struct g_part_table	base;
75 	u_char			mbr[MBRSIZE];
76 	struct gpt_hdr		hdr;
77 	quad_t			lba[GPT_ELT_COUNT];
78 	enum gpt_state		state[GPT_ELT_COUNT];
79 };
80 
81 struct g_part_gpt_entry {
82 	struct g_part_entry	base;
83 	struct gpt_ent		ent;
84 };
85 
86 static void g_gpt_printf_utf16(struct sbuf *, uint16_t *, size_t);
87 static void g_gpt_utf8_to_utf16(const uint8_t *, uint16_t *, size_t);
88 
89 static int g_part_gpt_add(struct g_part_table *, struct g_part_entry *,
90     struct g_part_parms *);
91 static int g_part_gpt_bootcode(struct g_part_table *, struct g_part_parms *);
92 static int g_part_gpt_create(struct g_part_table *, struct g_part_parms *);
93 static int g_part_gpt_destroy(struct g_part_table *, struct g_part_parms *);
94 static void g_part_gpt_dumpconf(struct g_part_table *, struct g_part_entry *,
95     struct sbuf *, const char *);
96 static int g_part_gpt_dumpto(struct g_part_table *, struct g_part_entry *);
97 static int g_part_gpt_modify(struct g_part_table *, struct g_part_entry *,
98     struct g_part_parms *);
99 static const char *g_part_gpt_name(struct g_part_table *, struct g_part_entry *,
100     char *, size_t);
101 static int g_part_gpt_probe(struct g_part_table *, struct g_consumer *);
102 static int g_part_gpt_read(struct g_part_table *, struct g_consumer *);
103 static const char *g_part_gpt_type(struct g_part_table *, struct g_part_entry *,
104     char *, size_t);
105 static int g_part_gpt_write(struct g_part_table *, struct g_consumer *);
106 
107 static kobj_method_t g_part_gpt_methods[] = {
108 	KOBJMETHOD(g_part_add,		g_part_gpt_add),
109 	KOBJMETHOD(g_part_bootcode,	g_part_gpt_bootcode),
110 	KOBJMETHOD(g_part_create,	g_part_gpt_create),
111 	KOBJMETHOD(g_part_destroy,	g_part_gpt_destroy),
112 	KOBJMETHOD(g_part_dumpconf,	g_part_gpt_dumpconf),
113 	KOBJMETHOD(g_part_dumpto,	g_part_gpt_dumpto),
114 	KOBJMETHOD(g_part_modify,	g_part_gpt_modify),
115 	KOBJMETHOD(g_part_name,		g_part_gpt_name),
116 	KOBJMETHOD(g_part_probe,	g_part_gpt_probe),
117 	KOBJMETHOD(g_part_read,		g_part_gpt_read),
118 	KOBJMETHOD(g_part_type,		g_part_gpt_type),
119 	KOBJMETHOD(g_part_write,	g_part_gpt_write),
120 	{ 0, 0 }
121 };
122 
123 static struct g_part_scheme g_part_gpt_scheme = {
124 	"GPT",
125 	g_part_gpt_methods,
126 	sizeof(struct g_part_gpt_table),
127 	.gps_entrysz = sizeof(struct g_part_gpt_entry),
128 	.gps_minent = 128,
129 	.gps_maxent = INT_MAX,
130 	.gps_bootcodesz = MBRSIZE,
131 };
132 G_PART_SCHEME_DECLARE(g_part_gpt);
133 
134 static struct uuid gpt_uuid_apple_hfs = GPT_ENT_TYPE_APPLE_HFS;
135 static struct uuid gpt_uuid_efi = GPT_ENT_TYPE_EFI;
136 static struct uuid gpt_uuid_freebsd = GPT_ENT_TYPE_FREEBSD;
137 static struct uuid gpt_uuid_freebsd_boot = GPT_ENT_TYPE_FREEBSD_BOOT;
138 static struct uuid gpt_uuid_freebsd_swap = GPT_ENT_TYPE_FREEBSD_SWAP;
139 static struct uuid gpt_uuid_freebsd_ufs = GPT_ENT_TYPE_FREEBSD_UFS;
140 static struct uuid gpt_uuid_freebsd_vinum = GPT_ENT_TYPE_FREEBSD_VINUM;
141 static struct uuid gpt_uuid_freebsd_zfs = GPT_ENT_TYPE_FREEBSD_ZFS;
142 static struct uuid gpt_uuid_linux_swap = GPT_ENT_TYPE_LINUX_SWAP;
143 static struct uuid gpt_uuid_mbr = GPT_ENT_TYPE_MBR;
144 static struct uuid gpt_uuid_unused = GPT_ENT_TYPE_UNUSED;
145 
146 static void
147 gpt_read_hdr(struct g_part_gpt_table *table, struct g_consumer *cp,
148     enum gpt_elt elt, struct gpt_hdr *hdr)
149 {
150 	struct uuid uuid;
151 	struct g_provider *pp;
152 	char *buf;
153 	quad_t lba, last;
154 	int error;
155 	uint32_t crc, sz;
156 
157 	pp = cp->provider;
158 	last = (pp->mediasize / pp->sectorsize) - 1;
159 	table->lba[elt] = (elt == GPT_ELT_PRIHDR) ? 1 : last;
160 	table->state[elt] = GPT_STATE_MISSING;
161 	buf = g_read_data(cp, table->lba[elt] * pp->sectorsize, pp->sectorsize,
162 	    &error);
163 	if (buf == NULL)
164 		return;
165 	bcopy(buf, hdr, sizeof(*hdr));
166 	if (memcmp(hdr->hdr_sig, GPT_HDR_SIG, sizeof(hdr->hdr_sig)) != 0)
167 		return;
168 
169 	table->state[elt] = GPT_STATE_CORRUPT;
170 	sz = le32toh(hdr->hdr_size);
171 	if (sz < 92 || sz > pp->sectorsize)
172 		return;
173 	crc = le32toh(hdr->hdr_crc_self);
174 	hdr->hdr_crc_self = 0;
175 	if (crc32(hdr, sz) != crc)
176 		return;
177 	hdr->hdr_size = sz;
178 	hdr->hdr_crc_self = crc;
179 
180 	table->state[elt] = GPT_STATE_INVALID;
181 	hdr->hdr_revision = le32toh(hdr->hdr_revision);
182 	if (hdr->hdr_revision < 0x00010000)
183 		return;
184 	hdr->hdr_lba_self = le64toh(hdr->hdr_lba_self);
185 	if (hdr->hdr_lba_self != table->lba[elt])
186 		return;
187 	hdr->hdr_lba_alt = le64toh(hdr->hdr_lba_alt);
188 
189 	/* Check the managed area. */
190 	hdr->hdr_lba_start = le64toh(hdr->hdr_lba_start);
191 	if (hdr->hdr_lba_start < 2 || hdr->hdr_lba_start >= last)
192 		return;
193 	hdr->hdr_lba_end = le64toh(hdr->hdr_lba_end);
194 	if (hdr->hdr_lba_end < hdr->hdr_lba_start || hdr->hdr_lba_end >= last)
195 		return;
196 
197 	/* Check the table location and size of the table. */
198 	hdr->hdr_entries = le32toh(hdr->hdr_entries);
199 	hdr->hdr_entsz = le32toh(hdr->hdr_entsz);
200 	if (hdr->hdr_entries == 0 || hdr->hdr_entsz < 128 ||
201 	    (hdr->hdr_entsz & 7) != 0)
202 		return;
203 	hdr->hdr_lba_table = le64toh(hdr->hdr_lba_table);
204 	if (hdr->hdr_lba_table < 2 || hdr->hdr_lba_table >= last)
205 		return;
206 	if (hdr->hdr_lba_table >= hdr->hdr_lba_start &&
207 	    hdr->hdr_lba_table <= hdr->hdr_lba_end)
208 		return;
209 	lba = hdr->hdr_lba_table +
210 	    (hdr->hdr_entries * hdr->hdr_entsz + pp->sectorsize - 1) /
211 	    pp->sectorsize - 1;
212 	if (lba >= last)
213 		return;
214 	if (lba >= hdr->hdr_lba_start && lba <= hdr->hdr_lba_end)
215 		return;
216 
217 	table->state[elt] = GPT_STATE_OK;
218 	le_uuid_dec(&hdr->hdr_uuid, &uuid);
219 	hdr->hdr_uuid = uuid;
220 	hdr->hdr_crc_table = le32toh(hdr->hdr_crc_table);
221 }
222 
223 static struct gpt_ent *
224 gpt_read_tbl(struct g_part_gpt_table *table, struct g_consumer *cp,
225     enum gpt_elt elt, struct gpt_hdr *hdr)
226 {
227 	struct g_provider *pp;
228 	struct gpt_ent *ent, *tbl;
229 	char *buf, *p;
230 	unsigned int idx, sectors, tblsz;
231 	int error;
232 
233 	pp = cp->provider;
234 	table->lba[elt] = hdr->hdr_lba_table;
235 
236 	table->state[elt] = GPT_STATE_MISSING;
237 	tblsz = hdr->hdr_entries * hdr->hdr_entsz;
238 	sectors = (tblsz + pp->sectorsize - 1) / pp->sectorsize;
239 	buf = g_read_data(cp, table->lba[elt] * pp->sectorsize,
240 	    sectors * pp->sectorsize, &error);
241 	if (buf == NULL)
242 		return (NULL);
243 
244 	table->state[elt] = GPT_STATE_CORRUPT;
245 	if (crc32(buf, tblsz) != hdr->hdr_crc_table) {
246 		g_free(buf);
247 		return (NULL);
248 	}
249 
250 	table->state[elt] = GPT_STATE_OK;
251 	tbl = g_malloc(hdr->hdr_entries * sizeof(struct gpt_ent),
252 	    M_WAITOK | M_ZERO);
253 
254 	for (idx = 0, ent = tbl, p = buf;
255 	     idx < hdr->hdr_entries;
256 	     idx++, ent++, p += hdr->hdr_entsz) {
257 		le_uuid_dec(p, &ent->ent_type);
258 		le_uuid_dec(p + 16, &ent->ent_uuid);
259 		ent->ent_lba_start = le64dec(p + 32);
260 		ent->ent_lba_end = le64dec(p + 40);
261 		ent->ent_attr = le64dec(p + 48);
262 		/* Keep UTF-16 in little-endian. */
263 		bcopy(p + 56, ent->ent_name, sizeof(ent->ent_name));
264 	}
265 
266 	g_free(buf);
267 	return (tbl);
268 }
269 
270 static int
271 gpt_matched_hdrs(struct gpt_hdr *pri, struct gpt_hdr *sec)
272 {
273 
274 	if (!EQUUID(&pri->hdr_uuid, &sec->hdr_uuid))
275 		return (0);
276 	return ((pri->hdr_revision == sec->hdr_revision &&
277 	    pri->hdr_size == sec->hdr_size &&
278 	    pri->hdr_lba_start == sec->hdr_lba_start &&
279 	    pri->hdr_lba_end == sec->hdr_lba_end &&
280 	    pri->hdr_entries == sec->hdr_entries &&
281 	    pri->hdr_entsz == sec->hdr_entsz &&
282 	    pri->hdr_crc_table == sec->hdr_crc_table) ? 1 : 0);
283 }
284 
285 static int
286 gpt_parse_type(const char *type, struct uuid *uuid)
287 {
288 	struct uuid tmp;
289 	const char *alias;
290 	int error;
291 
292 	if (type[0] == '!') {
293 		error = parse_uuid(type + 1, &tmp);
294 		if (error)
295 			return (error);
296 		if (EQUUID(&tmp, &gpt_uuid_unused))
297 			return (EINVAL);
298 		*uuid = tmp;
299 		return (0);
300 	}
301 	alias = g_part_alias_name(G_PART_ALIAS_EFI);
302 	if (!strcasecmp(type, alias)) {
303 		*uuid = gpt_uuid_efi;
304 		return (0);
305 	}
306 	alias = g_part_alias_name(G_PART_ALIAS_FREEBSD);
307 	if (!strcasecmp(type, alias)) {
308 		*uuid = gpt_uuid_freebsd;
309 		return (0);
310 	}
311 	alias = g_part_alias_name(G_PART_ALIAS_FREEBSD_BOOT);
312 	if (!strcasecmp(type, alias)) {
313 		*uuid = gpt_uuid_freebsd_boot;
314 		return (0);
315 	}
316 	alias = g_part_alias_name(G_PART_ALIAS_FREEBSD_SWAP);
317 	if (!strcasecmp(type, alias)) {
318 		*uuid = gpt_uuid_freebsd_swap;
319 		return (0);
320 	}
321 	alias = g_part_alias_name(G_PART_ALIAS_FREEBSD_UFS);
322 	if (!strcasecmp(type, alias)) {
323 		*uuid = gpt_uuid_freebsd_ufs;
324 		return (0);
325 	}
326 	alias = g_part_alias_name(G_PART_ALIAS_FREEBSD_VINUM);
327 	if (!strcasecmp(type, alias)) {
328 		*uuid = gpt_uuid_freebsd_vinum;
329 		return (0);
330 	}
331 	alias = g_part_alias_name(G_PART_ALIAS_FREEBSD_ZFS);
332 	if (!strcasecmp(type, alias)) {
333 		*uuid = gpt_uuid_freebsd_zfs;
334 		return (0);
335 	}
336 	alias = g_part_alias_name(G_PART_ALIAS_MBR);
337 	if (!strcasecmp(type, alias)) {
338 		*uuid = gpt_uuid_mbr;
339 		return (0);
340 	}
341 	alias = g_part_alias_name(G_PART_ALIAS_APPLE_HFS);
342 	if (!strcasecmp(type, alias)) {
343 		*uuid = gpt_uuid_apple_hfs;
344 		return (0);
345 	}
346 	return (EINVAL);
347 }
348 
349 static int
350 g_part_gpt_add(struct g_part_table *basetable, struct g_part_entry *baseentry,
351     struct g_part_parms *gpp)
352 {
353 	struct g_part_gpt_entry *entry;
354 	int error;
355 
356 	entry = (struct g_part_gpt_entry *)baseentry;
357 	error = gpt_parse_type(gpp->gpp_type, &entry->ent.ent_type);
358 	if (error)
359 		return (error);
360 	kern_uuidgen(&entry->ent.ent_uuid, 1);
361 	entry->ent.ent_lba_start = baseentry->gpe_start;
362 	entry->ent.ent_lba_end = baseentry->gpe_end;
363 	if (baseentry->gpe_deleted) {
364 		entry->ent.ent_attr = 0;
365 		bzero(entry->ent.ent_name, sizeof(entry->ent.ent_name));
366 	}
367 	if (gpp->gpp_parms & G_PART_PARM_LABEL)
368 		g_gpt_utf8_to_utf16(gpp->gpp_label, entry->ent.ent_name,
369 		    sizeof(entry->ent.ent_name));
370 	return (0);
371 }
372 
373 static int
374 g_part_gpt_bootcode(struct g_part_table *basetable, struct g_part_parms *gpp)
375 {
376 	struct g_part_gpt_table *table;
377 	size_t codesz;
378 
379 	codesz = DOSPARTOFF;
380 	table = (struct g_part_gpt_table *)basetable;
381 	bzero(table->mbr, codesz);
382 	codesz = MIN(codesz, gpp->gpp_codesize);
383 	if (codesz > 0)
384 		bcopy(gpp->gpp_codeptr, table->mbr, codesz);
385 	return (0);
386 }
387 
388 static int
389 g_part_gpt_create(struct g_part_table *basetable, struct g_part_parms *gpp)
390 {
391 	struct g_provider *pp;
392 	struct g_part_gpt_table *table;
393 	quad_t last;
394 	size_t tblsz;
395 
396 	/* We don't nest, which means that our depth should be 0. */
397 	if (basetable->gpt_depth != 0)
398 		return (ENXIO);
399 
400 	table = (struct g_part_gpt_table *)basetable;
401 	pp = gpp->gpp_provider;
402 	tblsz = (basetable->gpt_entries * sizeof(struct gpt_ent) +
403 	    pp->sectorsize - 1) / pp->sectorsize;
404 	if (pp->sectorsize < MBRSIZE ||
405 	    pp->mediasize < (3 + 2 * tblsz + basetable->gpt_entries) *
406 	    pp->sectorsize)
407 		return (ENOSPC);
408 
409 	last = (pp->mediasize / pp->sectorsize) - 1;
410 
411 	le16enc(table->mbr + DOSMAGICOFFSET, DOSMAGIC);
412 	table->mbr[DOSPARTOFF + 1] = 0x01;		/* shd */
413 	table->mbr[DOSPARTOFF + 2] = 0x01;		/* ssect */
414 	table->mbr[DOSPARTOFF + 3] = 0x00;		/* scyl */
415 	table->mbr[DOSPARTOFF + 4] = 0xee;		/* typ */
416 	table->mbr[DOSPARTOFF + 5] = 0xff;		/* ehd */
417 	table->mbr[DOSPARTOFF + 6] = 0xff;		/* esect */
418 	table->mbr[DOSPARTOFF + 7] = 0xff;		/* ecyl */
419 	le32enc(table->mbr + DOSPARTOFF + 8, 1);	/* start */
420 	le32enc(table->mbr + DOSPARTOFF + 12, MIN(last, 0xffffffffLL));
421 
422 	table->lba[GPT_ELT_PRIHDR] = 1;
423 	table->lba[GPT_ELT_PRITBL] = 2;
424 	table->lba[GPT_ELT_SECHDR] = last;
425 	table->lba[GPT_ELT_SECTBL] = last - tblsz;
426 
427 	bcopy(GPT_HDR_SIG, table->hdr.hdr_sig, sizeof(table->hdr.hdr_sig));
428 	table->hdr.hdr_revision = GPT_HDR_REVISION;
429 	table->hdr.hdr_size = offsetof(struct gpt_hdr, padding);
430 	table->hdr.hdr_lba_start = 2 + tblsz;
431 	table->hdr.hdr_lba_end = last - tblsz - 1;
432 	kern_uuidgen(&table->hdr.hdr_uuid, 1);
433 	table->hdr.hdr_entries = basetable->gpt_entries;
434 	table->hdr.hdr_entsz = sizeof(struct gpt_ent);
435 
436 	basetable->gpt_first = table->hdr.hdr_lba_start;
437 	basetable->gpt_last = table->hdr.hdr_lba_end;
438 	return (0);
439 }
440 
441 static int
442 g_part_gpt_destroy(struct g_part_table *basetable, struct g_part_parms *gpp)
443 {
444 
445 	/*
446 	 * Wipe the first 2 sectors as well as the last to clear the
447 	 * partitioning.
448 	 */
449 	basetable->gpt_smhead |= 3;
450 	basetable->gpt_smtail |= 1;
451 	return (0);
452 }
453 
454 static void
455 g_part_gpt_dumpconf(struct g_part_table *table, struct g_part_entry *baseentry,
456     struct sbuf *sb, const char *indent)
457 {
458 	struct g_part_gpt_entry *entry;
459 
460 	entry = (struct g_part_gpt_entry *)baseentry;
461 	if (indent == NULL) {
462 		/* conftxt: libdisk compatibility */
463 		sbuf_printf(sb, " xs GPT xt ");
464 		sbuf_printf_uuid(sb, &entry->ent.ent_type);
465 	} else if (entry != NULL) {
466 		/* confxml: partition entry information */
467 		sbuf_printf(sb, "%s<label>", indent);
468 		g_gpt_printf_utf16(sb, entry->ent.ent_name,
469 		    sizeof(entry->ent.ent_name) >> 1);
470 		sbuf_printf(sb, "</label>\n");
471 		sbuf_printf(sb, "%s<rawtype>", indent);
472 		sbuf_printf_uuid(sb, &entry->ent.ent_type);
473 		sbuf_printf(sb, "</rawtype>\n");
474 	} else {
475 		/* confxml: scheme information */
476 	}
477 }
478 
479 static int
480 g_part_gpt_dumpto(struct g_part_table *table, struct g_part_entry *baseentry)
481 {
482 	struct g_part_gpt_entry *entry;
483 
484 	entry = (struct g_part_gpt_entry *)baseentry;
485 	return ((EQUUID(&entry->ent.ent_type, &gpt_uuid_freebsd_swap) ||
486 	    EQUUID(&entry->ent.ent_type, &gpt_uuid_linux_swap)) ? 1 : 0);
487 }
488 
489 static int
490 g_part_gpt_modify(struct g_part_table *basetable,
491     struct g_part_entry *baseentry, struct g_part_parms *gpp)
492 {
493 	struct g_part_gpt_entry *entry;
494 	int error;
495 
496 	entry = (struct g_part_gpt_entry *)baseentry;
497 	if (gpp->gpp_parms & G_PART_PARM_TYPE) {
498 		error = gpt_parse_type(gpp->gpp_type, &entry->ent.ent_type);
499 		if (error)
500 			return (error);
501 	}
502 	if (gpp->gpp_parms & G_PART_PARM_LABEL)
503 		g_gpt_utf8_to_utf16(gpp->gpp_label, entry->ent.ent_name,
504 		    sizeof(entry->ent.ent_name));
505 	return (0);
506 }
507 
508 static const char *
509 g_part_gpt_name(struct g_part_table *table, struct g_part_entry *baseentry,
510     char *buf, size_t bufsz)
511 {
512 	struct g_part_gpt_entry *entry;
513 	char c;
514 
515 	entry = (struct g_part_gpt_entry *)baseentry;
516 	c = (EQUUID(&entry->ent.ent_type, &gpt_uuid_freebsd)) ? 's' : 'p';
517 	snprintf(buf, bufsz, "%c%d", c, baseentry->gpe_index);
518 	return (buf);
519 }
520 
521 static int
522 g_part_gpt_probe(struct g_part_table *table, struct g_consumer *cp)
523 {
524 	struct g_provider *pp;
525 	char *buf;
526 	int error, res;
527 
528 	/* We don't nest, which means that our depth should be 0. */
529 	if (table->gpt_depth != 0)
530 		return (ENXIO);
531 
532 	pp = cp->provider;
533 
534 	/*
535 	 * Sanity-check the provider. Since the first sector on the provider
536 	 * must be a PMBR and a PMBR is 512 bytes large, the sector size
537 	 * must be at least 512 bytes.  Also, since the theoretical minimum
538 	 * number of sectors needed by GPT is 6, any medium that has less
539 	 * than 6 sectors is never going to be able to hold a GPT. The
540 	 * number 6 comes from:
541 	 *	1 sector for the PMBR
542 	 *	2 sectors for the GPT headers (each 1 sector)
543 	 *	2 sectors for the GPT tables (each 1 sector)
544 	 *	1 sector for an actual partition
545 	 * It's better to catch this pathological case early than behaving
546 	 * pathologically later on...
547 	 */
548 	if (pp->sectorsize < MBRSIZE || pp->mediasize < 6 * pp->sectorsize)
549 		return (ENOSPC);
550 
551 	/* Check that there's a MBR. */
552 	buf = g_read_data(cp, 0L, pp->sectorsize, &error);
553 	if (buf == NULL)
554 		return (error);
555 	res = le16dec(buf + DOSMAGICOFFSET);
556 	g_free(buf);
557 	if (res != DOSMAGIC)
558 		return (ENXIO);
559 
560 	/* Check that there's a primary header. */
561 	buf = g_read_data(cp, pp->sectorsize, pp->sectorsize, &error);
562 	if (buf == NULL)
563 		return (error);
564 	res = memcmp(buf, GPT_HDR_SIG, 8);
565 	g_free(buf);
566 	if (res == 0)
567 		return (G_PART_PROBE_PRI_HIGH);
568 
569 	/* No primary? Check that there's a secondary. */
570 	buf = g_read_data(cp, pp->mediasize - pp->sectorsize, pp->sectorsize,
571 	    &error);
572 	if (buf == NULL)
573 		return (error);
574 	res = memcmp(buf, GPT_HDR_SIG, 8);
575 	g_free(buf);
576 	return ((res == 0) ? G_PART_PROBE_PRI_HIGH : ENXIO);
577 }
578 
579 static int
580 g_part_gpt_read(struct g_part_table *basetable, struct g_consumer *cp)
581 {
582 	struct gpt_hdr prihdr, sechdr;
583 	struct gpt_ent *tbl, *pritbl, *sectbl;
584 	struct g_provider *pp;
585 	struct g_part_gpt_table *table;
586 	struct g_part_gpt_entry *entry;
587 	u_char *buf;
588 	int error, index;
589 
590 	table = (struct g_part_gpt_table *)basetable;
591 	pp = cp->provider;
592 
593 	/* Read the PMBR */
594 	buf = g_read_data(cp, 0, pp->sectorsize, &error);
595 	if (buf == NULL)
596 		return (error);
597 	bcopy(buf, table->mbr, MBRSIZE);
598 	g_free(buf);
599 
600 	/* Read the primary header and table. */
601 	gpt_read_hdr(table, cp, GPT_ELT_PRIHDR, &prihdr);
602 	if (table->state[GPT_ELT_PRIHDR] == GPT_STATE_OK) {
603 		pritbl = gpt_read_tbl(table, cp, GPT_ELT_PRITBL, &prihdr);
604 	} else {
605 		table->state[GPT_ELT_PRITBL] = GPT_STATE_MISSING;
606 		pritbl = NULL;
607 	}
608 
609 	/* Read the secondary header and table. */
610 	gpt_read_hdr(table, cp, GPT_ELT_SECHDR, &sechdr);
611 	if (table->state[GPT_ELT_SECHDR] == GPT_STATE_OK) {
612 		sectbl = gpt_read_tbl(table, cp, GPT_ELT_SECTBL, &sechdr);
613 	} else {
614 		table->state[GPT_ELT_SECTBL] = GPT_STATE_MISSING;
615 		sectbl = NULL;
616 	}
617 
618 	/* Fail if we haven't got any good tables at all. */
619 	if (table->state[GPT_ELT_PRITBL] != GPT_STATE_OK &&
620 	    table->state[GPT_ELT_SECTBL] != GPT_STATE_OK) {
621 		printf("GEOM: %s: corrupt or invalid GPT detected.\n",
622 		    pp->name);
623 		printf("GEOM: %s: GPT rejected -- may not be recoverable.\n",
624 		    pp->name);
625 		return (EINVAL);
626 	}
627 
628 	/*
629 	 * If both headers are good but they disagree with each other,
630 	 * then invalidate one. We prefer to keep the primary header,
631 	 * unless the primary table is corrupt.
632 	 */
633 	if (table->state[GPT_ELT_PRIHDR] == GPT_STATE_OK &&
634 	    table->state[GPT_ELT_SECHDR] == GPT_STATE_OK &&
635 	    !gpt_matched_hdrs(&prihdr, &sechdr)) {
636 		if (table->state[GPT_ELT_PRITBL] == GPT_STATE_OK) {
637 			table->state[GPT_ELT_SECHDR] = GPT_STATE_INVALID;
638 			table->state[GPT_ELT_SECTBL] = GPT_STATE_MISSING;
639 		} else {
640 			table->state[GPT_ELT_PRIHDR] = GPT_STATE_INVALID;
641 			table->state[GPT_ELT_PRITBL] = GPT_STATE_MISSING;
642 		}
643 	}
644 
645 	if (table->state[GPT_ELT_PRITBL] != GPT_STATE_OK) {
646 		printf("GEOM: %s: the primary GPT table is corrupt or "
647 		    "invalid.\n", pp->name);
648 		printf("GEOM: %s: using the secondary instead -- recovery "
649 		    "strongly advised.\n", pp->name);
650 		table->hdr = sechdr;
651 		tbl = sectbl;
652 		if (pritbl != NULL)
653 			g_free(pritbl);
654 	} else {
655 		if (table->state[GPT_ELT_SECTBL] != GPT_STATE_OK) {
656 			printf("GEOM: %s: the secondary GPT table is corrupt "
657 			    "or invalid.\n", pp->name);
658 			printf("GEOM: %s: using the primary only -- recovery "
659 			    "suggested.\n", pp->name);
660 		}
661 		table->hdr = prihdr;
662 		tbl = pritbl;
663 		if (sectbl != NULL)
664 			g_free(sectbl);
665 	}
666 
667 	basetable->gpt_first = table->hdr.hdr_lba_start;
668 	basetable->gpt_last = table->hdr.hdr_lba_end;
669 	basetable->gpt_entries = table->hdr.hdr_entries;
670 
671 	for (index = basetable->gpt_entries - 1; index >= 0; index--) {
672 		if (EQUUID(&tbl[index].ent_type, &gpt_uuid_unused))
673 			continue;
674 		entry = (struct g_part_gpt_entry *)g_part_new_entry(basetable,
675 		    index+1, tbl[index].ent_lba_start, tbl[index].ent_lba_end);
676 		entry->ent = tbl[index];
677 	}
678 
679 	g_free(tbl);
680 	return (0);
681 }
682 
683 static const char *
684 g_part_gpt_type(struct g_part_table *basetable, struct g_part_entry *baseentry,
685     char *buf, size_t bufsz)
686 {
687 	struct g_part_gpt_entry *entry;
688 	struct uuid *type;
689 
690 	entry = (struct g_part_gpt_entry *)baseentry;
691 	type = &entry->ent.ent_type;
692 	if (EQUUID(type, &gpt_uuid_efi))
693 		return (g_part_alias_name(G_PART_ALIAS_EFI));
694 	if (EQUUID(type, &gpt_uuid_freebsd))
695 		return (g_part_alias_name(G_PART_ALIAS_FREEBSD));
696 	if (EQUUID(type, &gpt_uuid_freebsd_boot))
697 		return (g_part_alias_name(G_PART_ALIAS_FREEBSD_BOOT));
698 	if (EQUUID(type, &gpt_uuid_freebsd_swap))
699 		return (g_part_alias_name(G_PART_ALIAS_FREEBSD_SWAP));
700 	if (EQUUID(type, &gpt_uuid_freebsd_ufs))
701 		return (g_part_alias_name(G_PART_ALIAS_FREEBSD_UFS));
702 	if (EQUUID(type, &gpt_uuid_freebsd_vinum))
703 		return (g_part_alias_name(G_PART_ALIAS_FREEBSD_VINUM));
704 	if (EQUUID(type, &gpt_uuid_freebsd_zfs))
705 		return (g_part_alias_name(G_PART_ALIAS_FREEBSD_ZFS));
706 	if (EQUUID(type, &gpt_uuid_mbr))
707 		return (g_part_alias_name(G_PART_ALIAS_MBR));
708 	buf[0] = '!';
709 	snprintf_uuid(buf + 1, bufsz - 1, type);
710 	return (buf);
711 }
712 
713 static int
714 g_part_gpt_write(struct g_part_table *basetable, struct g_consumer *cp)
715 {
716 	unsigned char *buf, *bp;
717 	struct g_provider *pp;
718 	struct g_part_entry *baseentry;
719 	struct g_part_gpt_entry *entry;
720 	struct g_part_gpt_table *table;
721 	size_t tlbsz;
722 	uint32_t crc;
723 	int error, index;
724 
725 	pp = cp->provider;
726 	table = (struct g_part_gpt_table *)basetable;
727 	tlbsz = (table->hdr.hdr_entries * table->hdr.hdr_entsz +
728 	    pp->sectorsize - 1) / pp->sectorsize;
729 
730 	/* Write the PMBR */
731 	buf = g_malloc(pp->sectorsize, M_WAITOK | M_ZERO);
732 	bcopy(table->mbr, buf, MBRSIZE);
733 	error = g_write_data(cp, 0, buf, pp->sectorsize);
734 	g_free(buf);
735 	if (error)
736 		return (error);
737 
738 	/* Allocate space for the header and entries. */
739 	buf = g_malloc((tlbsz + 1) * pp->sectorsize, M_WAITOK | M_ZERO);
740 
741 	memcpy(buf, table->hdr.hdr_sig, sizeof(table->hdr.hdr_sig));
742 	le32enc(buf + 8, table->hdr.hdr_revision);
743 	le32enc(buf + 12, table->hdr.hdr_size);
744 	le64enc(buf + 40, table->hdr.hdr_lba_start);
745 	le64enc(buf + 48, table->hdr.hdr_lba_end);
746 	le_uuid_enc(buf + 56, &table->hdr.hdr_uuid);
747 	le32enc(buf + 80, table->hdr.hdr_entries);
748 	le32enc(buf + 84, table->hdr.hdr_entsz);
749 
750 	LIST_FOREACH(baseentry, &basetable->gpt_entry, gpe_entry) {
751 		if (baseentry->gpe_deleted)
752 			continue;
753 		entry = (struct g_part_gpt_entry *)baseentry;
754 		index = baseentry->gpe_index - 1;
755 		bp = buf + pp->sectorsize + table->hdr.hdr_entsz * index;
756 		le_uuid_enc(bp, &entry->ent.ent_type);
757 		le_uuid_enc(bp + 16, &entry->ent.ent_uuid);
758 		le64enc(bp + 32, entry->ent.ent_lba_start);
759 		le64enc(bp + 40, entry->ent.ent_lba_end);
760 		le64enc(bp + 48, entry->ent.ent_attr);
761 		memcpy(bp + 56, entry->ent.ent_name,
762 		    sizeof(entry->ent.ent_name));
763 	}
764 
765 	crc = crc32(buf + pp->sectorsize,
766 	    table->hdr.hdr_entries * table->hdr.hdr_entsz);
767 	le32enc(buf + 88, crc);
768 
769 	/* Write primary meta-data. */
770 	le32enc(buf + 16, 0);	/* hdr_crc_self. */
771 	le64enc(buf + 24, table->lba[GPT_ELT_PRIHDR]);	/* hdr_lba_self. */
772 	le64enc(buf + 32, table->lba[GPT_ELT_SECHDR]);	/* hdr_lba_alt. */
773 	le64enc(buf + 72, table->lba[GPT_ELT_PRITBL]);	/* hdr_lba_table. */
774 	crc = crc32(buf, table->hdr.hdr_size);
775 	le32enc(buf + 16, crc);
776 
777 	error = g_write_data(cp, table->lba[GPT_ELT_PRITBL] * pp->sectorsize,
778 	    buf + pp->sectorsize, tlbsz * pp->sectorsize);
779 	if (error)
780 		goto out;
781 	error = g_write_data(cp, table->lba[GPT_ELT_PRIHDR] * pp->sectorsize,
782 	    buf, pp->sectorsize);
783 	if (error)
784 		goto out;
785 
786 	/* Write secondary meta-data. */
787 	le32enc(buf + 16, 0);	/* hdr_crc_self. */
788 	le64enc(buf + 24, table->lba[GPT_ELT_SECHDR]);	/* hdr_lba_self. */
789 	le64enc(buf + 32, table->lba[GPT_ELT_PRIHDR]);	/* hdr_lba_alt. */
790 	le64enc(buf + 72, table->lba[GPT_ELT_SECTBL]);	/* hdr_lba_table. */
791 	crc = crc32(buf, table->hdr.hdr_size);
792 	le32enc(buf + 16, crc);
793 
794 	error = g_write_data(cp, table->lba[GPT_ELT_SECTBL] * pp->sectorsize,
795 	    buf + pp->sectorsize, tlbsz * pp->sectorsize);
796 	if (error)
797 		goto out;
798 	error = g_write_data(cp, table->lba[GPT_ELT_SECHDR] * pp->sectorsize,
799 	    buf, pp->sectorsize);
800 
801  out:
802 	g_free(buf);
803 	return (error);
804 }
805 
806 static void
807 g_gpt_printf_utf16(struct sbuf *sb, uint16_t *str, size_t len)
808 {
809 	u_int bo;
810 	uint32_t ch;
811 	uint16_t c;
812 
813 	bo = LITTLE_ENDIAN;	/* GPT is little-endian */
814 	while (len > 0 && *str != 0) {
815 		ch = (bo == BIG_ENDIAN) ? be16toh(*str) : le16toh(*str);
816 		str++, len--;
817 		if ((ch & 0xf800) == 0xd800) {
818 			if (len > 0) {
819 				c = (bo == BIG_ENDIAN) ? be16toh(*str)
820 				    : le16toh(*str);
821 				str++, len--;
822 			} else
823 				c = 0xfffd;
824 			if ((ch & 0x400) == 0 && (c & 0xfc00) == 0xdc00) {
825 				ch = ((ch & 0x3ff) << 10) + (c & 0x3ff);
826 				ch += 0x10000;
827 			} else
828 				ch = 0xfffd;
829 		} else if (ch == 0xfffe) { /* BOM (U+FEFF) swapped. */
830 			bo = (bo == BIG_ENDIAN) ? LITTLE_ENDIAN : BIG_ENDIAN;
831 			continue;
832 		} else if (ch == 0xfeff) /* BOM (U+FEFF) unswapped. */
833 			continue;
834 
835 		/* Write the Unicode character in UTF-8 */
836 		if (ch < 0x80)
837 			sbuf_printf(sb, "%c", ch);
838 		else if (ch < 0x800)
839 			sbuf_printf(sb, "%c%c", 0xc0 | (ch >> 6),
840 			    0x80 | (ch & 0x3f));
841 		else if (ch < 0x10000)
842 			sbuf_printf(sb, "%c%c%c", 0xe0 | (ch >> 12),
843 			    0x80 | ((ch >> 6) & 0x3f), 0x80 | (ch & 0x3f));
844 		else if (ch < 0x200000)
845 			sbuf_printf(sb, "%c%c%c%c", 0xf0 | (ch >> 18),
846 			    0x80 | ((ch >> 12) & 0x3f),
847 			    0x80 | ((ch >> 6) & 0x3f), 0x80 | (ch & 0x3f));
848 	}
849 }
850 
851 static void
852 g_gpt_utf8_to_utf16(const uint8_t *s8, uint16_t *s16, size_t s16len)
853 {
854 	size_t s16idx, s8idx;
855 	uint32_t utfchar;
856 	unsigned int c, utfbytes;
857 
858 	s8idx = s16idx = 0;
859 	utfchar = 0;
860 	utfbytes = 0;
861 	bzero(s16, s16len << 1);
862 	while (s8[s8idx] != 0 && s16idx < s16len) {
863 		c = s8[s8idx++];
864 		if ((c & 0xc0) != 0x80) {
865 			/* Initial characters. */
866 			if (utfbytes != 0) {
867 				/* Incomplete encoding of previous char. */
868 				s16[s16idx++] = htole16(0xfffd);
869 			}
870 			if ((c & 0xf8) == 0xf0) {
871 				utfchar = c & 0x07;
872 				utfbytes = 3;
873 			} else if ((c & 0xf0) == 0xe0) {
874 				utfchar = c & 0x0f;
875 				utfbytes = 2;
876 			} else if ((c & 0xe0) == 0xc0) {
877 				utfchar = c & 0x1f;
878 				utfbytes = 1;
879 			} else {
880 				utfchar = c & 0x7f;
881 				utfbytes = 0;
882 			}
883 		} else {
884 			/* Followup characters. */
885 			if (utfbytes > 0) {
886 				utfchar = (utfchar << 6) + (c & 0x3f);
887 				utfbytes--;
888 			} else if (utfbytes == 0)
889 				utfbytes = ~0;
890 		}
891 		/*
892 		 * Write the complete Unicode character as UTF-16 when we
893 		 * have all the UTF-8 charactars collected.
894 		 */
895 		if (utfbytes == 0) {
896 			/*
897 			 * If we need to write 2 UTF-16 characters, but
898 			 * we only have room for 1, then we truncate the
899 			 * string by writing a 0 instead.
900 			 */
901 			if (utfchar >= 0x10000 && s16idx < s16len - 1) {
902 				s16[s16idx++] =
903 				    htole16(0xd800 | ((utfchar >> 10) - 0x40));
904 				s16[s16idx++] =
905 				    htole16(0xdc00 | (utfchar & 0x3ff));
906 			} else
907 				s16[s16idx++] = (utfchar >= 0x10000) ? 0 :
908 				    htole16(utfchar);
909 		}
910 	}
911 	/*
912 	 * If our input string was truncated, append an invalid encoding
913 	 * character to the output string.
914 	 */
915 	if (utfbytes != 0 && s16idx < s16len)
916 		s16[s16idx++] = htole16(0xfffd);
917 }
918