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      1 /* $NetBSD: gptsubr.c,v 1.5 2025/03/02 01:07:11 riastradh Exp $ */
      2 
      3 /*
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  * 1. Redistributions of source code must retain the above copyright
      8  *    notice, this list of conditions and the following disclaimer.
      9  * 2. Redistributions in binary form must reproduce the above copyright
     10  *    notice, this list of conditions and the following disclaimer in the
     11  *    documentation and/or other materials provided with the distribution.
     12  *
     13  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
     14  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     15  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     16  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     17  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     18  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
     19  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     20  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     21  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     22  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     23  * SUCH DAMAGE.
     24  */
     25 
     26 #include <sys/cdefs.h>
     27 #ifndef lint
     28 __RCSID("$NetBSD: gptsubr.c,v 1.5 2025/03/02 01:07:11 riastradh Exp $");
     29 #endif /* not lint */
     30 
     31 #include <sys/param.h>
     32 
     33 #include <sys/disk.h>
     34 #include <sys/disklabel.h>
     35 #include <sys/disklabel_gpt.h>
     36 #include <sys/dkio.h>
     37 #include <sys/ioctl.h>
     38 #include <sys/stat.h>
     39 #include <sys/statvfs.h>
     40 
     41 #include <err.h>
     42 #include <fcntl.h>
     43 #include <libgen.h>
     44 #include <paths.h>
     45 #include <stdbool.h>
     46 #include <stdio.h>
     47 #include <stdlib.h>
     48 #include <unistd.h>
     49 #include <uuid.h>
     50 
     51 #include "defs.h"
     52 #include "gpt.h"
     53 #include "gptsubr.h"
     54 #include "map.h"
     55 
     56 #define DEBUG
     57 
     58 #ifdef DEBUG
     59 #define DPRINTF(fmt, ...)	printf(fmt, __VA_ARGS__)
     60 #else
     61 #define DPRINTF(fmt, ...)	do { } while (/*CONSTCOND*/0)
     62 #endif
     63 
     64 static const char *
     65 map_type_name(int map_type)
     66 {
     67 	const char *xtbl[] = {
     68 		"UNUSED",	// 0
     69 		"MBR",		// 1
     70 		"MBR_PART",	// 2
     71 		"PRI_GPT_HDR",	// 3
     72 		"SEC_GPT_HDR",	// 4
     73 		"PRI_GPT_TBL",	// 5
     74 		"SEC_GPT_TBL",	// 6
     75 		"GPT_PART",	// 7
     76 		"PMBR",		// 8
     77 	};
     78 
     79 	if (map_type >= (int)__arraycount(xtbl))
     80 		return "UNKNOWN";
     81 
     82 	return xtbl[map_type];
     83 }
     84 
     85 #if 0
     86 struct map {
     87 	off_t	map_start;
     88 	off_t	map_size;
     89 	struct map *map_next;
     90 	struct map *map_prev;
     91 	int	map_type;
     92 #define	MAP_TYPE_UNUSED		0
     93 #define	MAP_TYPE_MBR		1
     94 #define	MAP_TYPE_MBR_PART	2
     95 #define	MAP_TYPE_PRI_GPT_HDR	3
     96 #define	MAP_TYPE_SEC_GPT_HDR	4
     97 #define	MAP_TYPE_PRI_GPT_TBL	5
     98 #define	MAP_TYPE_SEC_GPT_TBL	6
     99 #define	MAP_TYPE_GPT_PART	7
    100 #define	MAP_TYPE_PMBR		8
    101 	unsigned int map_index;
    102 	void 	*map_data;
    103 	int	map_alloc;
    104 };
    105 
    106 struct gpt_ent {
    107 	uint8_t		ent_type[16];	/* partition type GUID */
    108 	uint8_t		ent_guid[16];	/* unique partition GUID */
    109 	uint64_t	ent_lba_start;	/* start of partition */
    110 	uint64_t	ent_lba_end;	/* end of partition */
    111 	uint64_t	ent_attr;	/* partition attributes */
    112 	uint16_t	ent_name[36];	/* partition name in UCS-2 */
    113 };
    114 
    115 struct gpt_hdr {
    116 	int8_t		hdr_sig[8];	/* identifies GUID Partition Table */
    117 	uint32_t	hdr_revision;	/* GPT specification revision */
    118 	uint32_t	hdr_size;	/* size of GPT Header */
    119 	uint32_t	hdr_crc_self;	/* CRC32 of GPT Header */
    120 	uint32_t	hdr__rsvd0;	/* must be zero */
    121 	uint64_t	hdr_lba_self;	/* LBA that contains this Header */
    122 	uint64_t	hdr_lba_alt;	/* LBA of backup GPT Header */
    123 	uint64_t	hdr_lba_start;	/* first LBA usable for partitions */
    124 	uint64_t	hdr_lba_end;	/* last LBA usable for partitions */
    125 	uint8_t		hdr_guid[16];	/* GUID to identify the disk */
    126 	uint64_t	hdr_lba_table;	/* first LBA of GPE array */
    127 	uint32_t	hdr_entries;	/* number of entries in GPE array */
    128 	uint32_t	hdr_entsz;	/* size of each GPE */
    129 	uint32_t	hdr_crc_table;	/* CRC32 of GPE array */
    130 	/*
    131 	 * The remainder of the block that contains the GPT Header
    132 	 * is reserved by EFI for future GPT Header expansion, and
    133 	 * must be zero.
    134 	 */
    135 };
    136 #endif
    137 
    138 struct map_widths {
    139 	uint start;
    140 	uint size;
    141 	uint type_name;
    142 };
    143 
    144 static struct map_widths
    145 get_map_widths(gpt_t gpt)
    146 {
    147 	struct map_widths w;
    148 	off_t max_start = 0;
    149 	off_t max_size = 0;
    150 	map_t m;
    151 
    152 	w.type_name = 0;
    153 	for (m = map_first(gpt); m != NULL; m = m->map_next) {
    154 		uint n;
    155 
    156 		if (max_start < m->map_start)
    157 			max_start = m->map_start;
    158 		if (max_size < m->map_size)
    159 			max_size = m->map_size;
    160 		if (m->map_type == MAP_TYPE_GPT_PART) {
    161 			struct gpt_ent *ent = m->map_data;
    162 			gpt_uuid_t gpt_uuid;
    163 			char ent_type[128];
    164 
    165 			memcpy(&gpt_uuid, ent->ent_type, sizeof(gpt_uuid));
    166 			n = (uint)gpt_uuid_snprintf(ent_type, sizeof(ent_type),
    167 			    "%s", gpt_uuid);
    168 			if (w.type_name < n)
    169 				w.type_name = n;
    170 		}
    171 
    172 	}
    173 	w.start = (uint)snprintf(NULL, 0, "%" PRIx64, max_start);
    174 	w.size = (uint)snprintf(NULL, 0, "%" PRIx64, max_size);
    175 
    176 #define MIN_WIDTH_OF(s)	(sizeof(s) - 1)
    177 	if (w.type_name < MIN_WIDTH_OF("TYPE_NAME"))
    178 		w.type_name = MIN_WIDTH_OF("TYPE_NAME");
    179 	if (w.start < MIN_WIDTH_OF("START"))
    180 		w.start = MIN_WIDTH_OF("START");
    181 	if (w.size < MIN_WIDTH_OF("SIZE"))
    182 		w.size = MIN_WIDTH_OF("SIZE");
    183 #undef MIN_WIDTH_OF
    184 
    185 	return w;
    186 }
    187 
    188 static void
    189 show_map_banner(struct map_widths w)
    190 {
    191 
    192 	printf("IDX %*s %*s   ATTR            PARTITION_GUID"
    193 	    "                         TYPE_UUID       %*s "
    194 	    "TYPE_NAME ENTRY_NAME  DESCRIPTION\n",
    195 	    w.start, "START",
    196 	    w.size, "SIZE",
    197 	    w.type_name, "");
    198 }
    199 
    200 static void
    201 show_map(map_t m, struct map_widths w)
    202 {
    203 	struct gpt_ent *ent;
    204 	struct gpt_hdr *hdr;
    205 	gpt_uuid_t gpt_uuid;
    206 	uuid_t uuid;
    207 	uint32_t status;
    208 	char *type_uuid;
    209 	char *part_guid;
    210 	uint64_t ent_attr;
    211 	uint8_t  ent_desc[128];
    212 	char     ent_type[128];
    213 
    214 	ent_desc[0] = '\0';
    215 	ent_type[0] = '\0';
    216 	ent_attr = 0;
    217 
    218 	switch (m->map_type) {
    219 	case MAP_TYPE_PRI_GPT_HDR:
    220 	case MAP_TYPE_SEC_GPT_HDR:
    221 		hdr = m->map_data;
    222 		memcpy(&uuid, hdr->hdr_guid, sizeof(uuid));
    223 		uuid_to_string(&uuid, &part_guid, &status);
    224 		type_uuid = estrdup("");
    225 		break;
    226 
    227 	case MAP_TYPE_GPT_PART:
    228 		ent = m->map_data;
    229 
    230 		memcpy(&uuid, ent->ent_type, sizeof(uuid));
    231 		uuid_to_string(&uuid, &type_uuid, &status);
    232 
    233 		memcpy(&uuid, ent->ent_guid, sizeof(uuid));
    234 		uuid_to_string(&uuid, &part_guid, &status);
    235 
    236 		ent_attr = ent->ent_attr;
    237 
    238 		memcpy(&gpt_uuid, ent->ent_type, sizeof(uuid));
    239 		gpt_uuid_snprintf(ent_type, sizeof(ent_type), "%s", gpt_uuid);
    240 
    241 		/*
    242 		 * Use the gpt.c code here rather than our
    243 		 * ucs2_to_utf8() as we are in their world.
    244 		 */
    245 		utf16_to_utf8(ent->ent_name, sizeof(ent->ent_name),
    246 		    ent_desc, sizeof(ent_desc));
    247 
    248 		break;
    249 
    250 	case MAP_TYPE_MBR_PART:
    251 		part_guid = estrdup("");
    252 		type_uuid = estrdup("");
    253 		break;
    254 
    255 	case MAP_TYPE_MBR: {
    256 		struct mbr *mbr = m->map_data;
    257 
    258 		easprintf(&part_guid,
    259 		    "%02x%02x%02x%02x-0000-0000-0000-000000000000",
    260 		    mbr->mbr_code[440],
    261 		    mbr->mbr_code[441],
    262 		    mbr->mbr_code[442],
    263 		    mbr->mbr_code[443]);
    264 		uuid_to_string(&(uuid_t)GPT_ENT_TYPE_MBR, &type_uuid, &status);
    265 		break;
    266 	}
    267 	default:
    268 		part_guid = estrdup("");
    269 		type_uuid = estrdup("");
    270 		break;
    271 	}
    272 
    273 	printf("%2u: %*" PRIx64 " %*" PRIx64 " %08" PRIx64
    274 	    " %36s %36s %*s %-11s %s\n",
    275 	    m->map_index,
    276 	    w.start,
    277 	    m->map_start,
    278 	    w.size,
    279 	    m->map_size,
    280 	    ent_attr,
    281 	    part_guid,
    282 	    type_uuid,
    283 	    w.type_name,
    284 	    ent_type,
    285 	    map_type_name(m->map_type),
    286 	    ent_desc);
    287 
    288 	free(part_guid);
    289 	free(type_uuid);
    290 }
    291 
    292 PUBLIC map_t
    293 find_gpt_map(const char *dev, uint idx)
    294 {
    295 	gpt_t gpt;
    296 	map_t m;
    297 
    298 	gpt = gpt_open(dev, GPT_READONLY, 0, 0, 0, 0);
    299 
    300 	if (gpt == NULL)
    301 		err(EXIT_FAILURE, "gpt_open");
    302 
    303 	if (map_find(gpt, MAP_TYPE_PRI_GPT_HDR) == NULL)
    304 		printf("GPT not found, displaying data from MBR.\n");
    305 
    306 	for (m = map_first(gpt); m != NULL; m = m->map_next) {
    307 		if (m->map_index == idx)
    308 			break;
    309 	}
    310 	gpt_close(gpt);
    311 	return m;
    312 }
    313 
    314 PUBLIC char *
    315 parent_of_fname(const char *fname)
    316 {
    317 	struct dkwedge_info dkinfo;
    318 	struct statvfs vfsb;
    319 	struct stat sb;
    320 	const char *d, *b;
    321 	char *p;
    322 	size_t n;
    323 	int fd, rv;
    324 
    325 	rv = stat(fname, &sb);
    326 	if (rv == -1)
    327 		err(EXIT_FAILURE, "stat: %s", fname);
    328 
    329 	if (S_ISBLK(sb.st_mode) || S_ISCHR(sb.st_mode))
    330 		return estrdup(fname);
    331 
    332 	rv = statvfs(fname, &vfsb);
    333 	if (rv == -1)
    334 		err(EXIT_FAILURE, "statvfs: %s", fname);
    335 
    336 	b = basename(vfsb.f_mntfromname);
    337 	d = dirname(vfsb.f_mntfromname);
    338 	easprintf(&p, "%s/r%s", d, b);
    339 
    340 	fd = open(p, O_RDONLY);
    341 	if (fd == -1)
    342 		err(EXIT_FAILURE, "open");
    343 
    344 	rv = ioctl(fd, DIOCGWEDGEINFO, &dkinfo);
    345 	close(fd);
    346 
    347 	if (rv != -1) {
    348 		free(p);
    349 		return estrdup(dkinfo.dkw_parent);
    350 	}
    351 
    352 	warn("ioctl: DIOCGWEDGEINFO");
    353 
    354 	/*
    355 	 * Hum.  No wedges?  Assume we have the old disklabel
    356 	 * "/dev/rwd0x" syntax.  Convert it to "/dev/rwd0d".
    357 	 * XXX: this probably won't work.
    358 	 */
    359 	n = strlen(p);
    360 	p[n - 1] = 'd';
    361 
    362 	return p;
    363 }
    364 
    365 PUBLIC int
    366 mbr_sig_write(const char *fname, uint32_t new_sig, bool force, int verbose)
    367 {
    368 	gpt_t gpt;
    369 	map_t m;
    370 	struct mbr *mbr;
    371 	const char *dev;
    372 	uint32_t old_sig;
    373 
    374 	if (fname == NULL)
    375 		errx(EXIT_FAILURE, "please specify a device");
    376 
    377 	dev = parent_of_fname(fname);
    378 	if (dev == NULL) {
    379 		warnx("unable to find parent device of %s\n", fname);
    380 		return -1;
    381 	}
    382 
    383 	gpt = gpt_open(dev, GPT_MODIFIED, verbose, 0, 0, 0);
    384 
    385 	if (gpt == NULL)
    386 		err(EXIT_FAILURE, "gpt_open");
    387 
    388 	m = map_find(gpt, MAP_TYPE_MBR);
    389 	if (m == NULL)
    390 		printf("No MBR partition found!\n");
    391 	else {
    392 		mbr = m->map_data;
    393 
    394 		memcpy(&old_sig, &mbr->mbr_code[440], 4);
    395 
    396 		if (old_sig == 0)
    397 			force = true;
    398 
    399 		if (force) {
    400 			memcpy(&mbr->mbr_code[440], &new_sig, 4);
    401 			if (gpt_write(gpt, m) == -1)
    402 				warn("gpt_write");
    403 			else if (verbose)
    404 				printf("sig: 0x%08x -> 0x%08x\n",
    405 				    old_sig, new_sig);
    406 		}
    407 		else if (verbose)
    408 			printf("sig: 0x%08x (unchanged)\n", old_sig);
    409 	}
    410 
    411 	gpt_close(gpt);
    412 	return 0;
    413 }
    414 
    415 PUBLIC int
    416 show_gpt(const char *fname, int verbose)
    417 {
    418 	gpt_t gpt;
    419 	map_t m;
    420 	struct map_widths w;
    421 	const char *dev;
    422 
    423 	dev = parent_of_fname(fname);
    424 	if (dev == NULL)
    425 		return -1;
    426 
    427 	gpt = gpt_open(dev, GPT_READONLY, verbose, 0, 0, 0);
    428 
    429 	if (gpt == NULL)
    430 		err(EXIT_FAILURE, "gpt_open");
    431 
    432 	if (map_find(gpt, MAP_TYPE_PRI_GPT_HDR) == NULL)
    433 		warnx("GPT not found, displaying data from MBR.");
    434 
    435 	w = get_map_widths(gpt);
    436 	show_map_banner(w);
    437 
    438 	for (m = map_first(gpt); m != NULL; m = m->map_next)
    439 		show_map(m, w);
    440 
    441 	gpt_close(gpt);
    442 	return 0;
    443 }
    444 
    445 #if 0 /* UNUSED */
    446 
    447 PUBLIC char *
    448 wedge_of_fname(const char *fname)
    449 {
    450 	struct statvfs vfsbuf;
    451 	int rv;
    452 
    453 	rv = statvfs(fname, &vfsbuf);
    454 	if (rv) {
    455 		warn("statvfs: %s", fname);
    456 		return NULL;
    457 	}
    458 
    459 	return estrdup(vfsbuf.f_mntfromname);
    460 }
    461 
    462 PUBLIC int
    463 find_partition_idx(const char *fname, int verbose)
    464 {
    465 	struct dkwedge_info dkinfo;
    466 	struct stat sb;
    467 	struct statvfs vfsbuf;
    468 	gpt_t gpt;
    469 	map_t m;
    470 	off_t offset;
    471 	size_t size;
    472 	const char *parent;
    473 	char *b, *d;
    474 	int rv;
    475 
    476 	/* the following are for gpt_open() */
    477 	off_t mediasz = 0;
    478 	u_int secsz = 0;
    479 	time_t timestamp = 0;
    480 
    481 	rv = stat(fname, &sb);
    482 	if (rv == -1)
    483 		err(EXIT_FAILURE, "stat: %s", fname);
    484 
    485 	if (S_ISBLK(sb.st_mode) || S_ISCHR(sb.st_mode)) {
    486 		parent = fname;
    487 		offset = 0;
    488 		size = 0;
    489 		goto doit;
    490 	}
    491 
    492 	rv = statvfs(fname, &vfsbuf);
    493 	if (rv == -1)
    494 		err(EXIT_FAILURE, "statvfs: %s", fname);
    495 
    496 	b = basename(vfsbuf.f_mntfromname);
    497 	d = dirname(vfsbuf.f_mntfromname);
    498 
    499 	{
    500 		char *p;
    501 
    502 		easprintf(&p, "%s/r%s", d, b);
    503 
    504 		int fd = open(p, O_RDONLY);
    505 		if (fd == -1)
    506 			err(EXIT_FAILURE, "open");
    507 
    508 		rv = ioctl(fd, DIOCGWEDGEINFO, &dkinfo);
    509 		if (rv != -1) {
    510 			parent = dkinfo.dkw_parent;
    511 			offset = dkinfo.dkw_offset;
    512 			size   = dkinfo.dkw_size;
    513 		}
    514 		else {
    515 			struct disklabel dl;
    516 
    517 			warn("ioctl: DIOCGWEDGEINFO");
    518 
    519 			rv = ioctl(fd, DIOCGDINFO, &dl);
    520 			if (rv == -1)
    521 				err(EXIT_FAILURE, "ioctl: DIOCGDINFO");
    522 
    523 			size_t n = strlen(p);
    524 
    525 			int pnum = p[n - 1] - 'a';
    526 			p[n - 1] = 'd';
    527 
    528 			printf("num_parts: %u\n", dl.d_npartitions);
    529 			printf("partition %d\n", pnum);
    530 			printf("  offset = %u (%#x)\n",
    531 			    dl.d_partitions[pnum].p_offset,
    532 			    dl.d_partitions[pnum].p_offset);
    533 			printf("  size = %u (%#x)\n",
    534 			    dl.d_partitions[pnum].p_size,
    535 			    dl.d_partitions[pnum].p_size);
    536 
    537 			parent = p;	// vfsbuf.f_mntfromname;
    538 			offset = dl.d_partitions[pnum].p_offset;
    539 			size   = dl.d_partitions[pnum].p_size;
    540 		}
    541 
    542 		close(fd);
    543 		free(p);
    544 	}
    545 
    546  doit:
    547 	DPRINTF("parent: %s\n", parent);
    548 	DPRINTF("offset: 0x%lx\n", offset);
    549 	DPRINTF("size: 0x%lx\n", size);
    550 
    551 	gpt = gpt_open(parent, GPT_READONLY,
    552 	    verbose, mediasz, secsz, timestamp);
    553 
    554 	if (gpt == NULL)
    555 		err(EXIT_FAILURE, "gpt_open");
    556 
    557 	if (map_find(gpt, MAP_TYPE_PRI_GPT_HDR) == NULL)
    558 		printf("GPT not found, displaying data from MBR.\n");
    559 
    560 	int index = -1;
    561 	struct map_widths w;
    562 	if (verbose) {
    563 		w = get_map_widths(gpt);
    564 		show_map_banner(w);
    565 	}
    566 	for (m = map_first(gpt); m != NULL; m = m->map_next) {
    567 		if (verbose)
    568 			show_map(m, w);
    569 
    570 		if (m->map_type != MAP_TYPE_GPT_PART || m->map_index < 1) {
    571 			continue;
    572 		}
    573 
    574 		if ((off_t)offset == m->map_start &&
    575 		    (off_t)size   == m->map_size) {
    576 			if (index != -1)
    577 				printf("match: %u\n", index);
    578 			index = (int)m->map_index;
    579 		}
    580 	}
    581 	return index;
    582 }
    583 
    584 PUBLIC char *
    585 find_partition_pathname(const char *fname)
    586 {
    587 	char *pname;	/* partition name */
    588 	char *rname;	/* real name */
    589 	struct statvfs vfsbuf;
    590 	int i, rv;
    591 
    592 	rname = realpath(fname, NULL);
    593 
    594 	DPRINTF("fname: %s\n", fname);
    595 	DPRINTF("rname: %s\n", rname);
    596 
    597 	rv = statvfs(rname, &vfsbuf);
    598 	if (rv) {
    599 		warn("statvfs: %s", rname);
    600 		free(rname);
    601 		return NULL;
    602 	}
    603 
    604 	DPRINTF("mount: %s\n", vfsbuf.f_mntonname);
    605 
    606 	i = 0;
    607 	while (vfsbuf.f_mntonname[i] == rname[i] &&
    608 	    vfsbuf.f_mntonname[i] != '\0')
    609 		i++;
    610 
    611 	if (vfsbuf.f_mntonname[i] != '\0')
    612 		errx(EXIT_FAILURE, "mntonname mismatch: %s",
    613 		    vfsbuf.f_mntonname + i);
    614 
    615 	pname = estrdup(rname + i);
    616 	free(rname);
    617 
    618 	return pname;
    619 }
    620 
    621 #endif
    622