1 /*	$OpenBSD: efi_installboot.c,v 1.10 2023/04/26 18:04:21 kn Exp $	*/
2 /*	$NetBSD: installboot.c,v 1.5 1995/11/17 23:23:50 gwr Exp $ */
3 
4 /*
5  * Copyright (c) 2011 Joel Sing <jsing@openbsd.org>
6  * Copyright (c) 2010 Otto Moerbeek <otto@openbsd.org>
7  * Copyright (c) 2003 Tom Cosgrove <tom.cosgrove@arches-consulting.com>
8  * Copyright (c) 1997 Michael Shalayeff
9  * Copyright (c) 1994 Paul Kranenburg
10  * All rights reserved.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. All advertising materials mentioning features or use of this software
21  *    must display the following acknowledgement:
22  *      This product includes software developed by Paul Kranenburg.
23  * 4. The name of the author may not be used to endorse or promote products
24  *    derived from this software without specific prior written permission
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
27  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
28  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
29  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
30  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
31  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
35  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36  */
37 
38 #include <sys/param.h>	/* DEV_BSIZE */
39 #include <sys/disklabel.h>
40 #include <sys/dkio.h>
41 #include <sys/ioctl.h>
42 #include <sys/mount.h>
43 #include <sys/stat.h>
44 
45 #include <err.h>
46 #include <errno.h>
47 #include <fcntl.h>
48 #include <stdlib.h>
49 #include <stdio.h>
50 #include <stdint.h>
51 #include <string.h>
52 #include <unistd.h>
53 #include <util.h>
54 #include <uuid.h>
55 
56 #include "installboot.h"
57 
58 #if defined(__aarch64__)
59 #define BOOTEFI_SRC	"BOOTAA64.EFI"
60 #define BOOTEFI_DST	"bootaa64.efi"
61 #elif defined(__arm__)
62 #define BOOTEFI_SRC	"BOOTARM.EFI"
63 #define BOOTEFI_DST	"bootarm.efi"
64 #elif defined(__riscv)
65 #define BOOTEFI_SRC	"BOOTRISCV64.EFI"
66 #define BOOTEFI_DST	"bootriscv64.efi"
67 #else
68 #error "unhandled architecture"
69 #endif
70 
71 static int	create_filesystem(struct disklabel *, char);
72 static void	write_filesystem(struct disklabel *, char);
73 static int	write_firmware(const char *, const char *);
74 static int	findgptefisys(int, struct disklabel *);
75 static int	findmbrfat(int, struct disklabel *);
76 
77 void
md_init(void)78 md_init(void)
79 {
80 	stages = 1;
81 	stage1 = "/usr/mdec/" BOOTEFI_SRC;
82 }
83 
84 void
md_loadboot(void)85 md_loadboot(void)
86 {
87 }
88 
89 void
md_prepareboot(int devfd,char * dev)90 md_prepareboot(int devfd, char *dev)
91 {
92 	struct disklabel dl;
93 	int part;
94 
95 	/* Get and check disklabel. */
96 	if (ioctl(devfd, DIOCGDINFO, &dl) == -1)
97 		err(1, "disklabel: %s", dev);
98 	if (dl.d_magic != DISKMAGIC)
99 		errx(1, "bad disklabel magic=0x%08x", dl.d_magic);
100 
101 	/* Warn on unknown disklabel types. */
102 	if (dl.d_type == 0)
103 		warnx("disklabel type unknown");
104 
105 	part = findgptefisys(devfd, &dl);
106 	if (part != -1) {
107 		create_filesystem(&dl, (char)part);
108 		return;
109 	}
110 
111 	part = findmbrfat(devfd, &dl);
112 	if (part != -1) {
113 		create_filesystem(&dl, (char)part);
114 		return;
115 	}
116 }
117 
118 void
md_installboot(int devfd,char * dev)119 md_installboot(int devfd, char *dev)
120 {
121 	struct disklabel dl;
122 	int part;
123 
124 	/* Get and check disklabel. */
125 	if (ioctl(devfd, DIOCGDINFO, &dl) == -1)
126 		err(1, "disklabel: %s", dev);
127 	if (dl.d_magic != DISKMAGIC)
128 		errx(1, "bad disklabel magic=0x%08x", dl.d_magic);
129 
130 	/* Warn on unknown disklabel types. */
131 	if (dl.d_type == 0)
132 		warnx("disklabel type unknown");
133 
134 	part = findgptefisys(devfd, &dl);
135 	if (part != -1) {
136 		write_filesystem(&dl, (char)part);
137 		return;
138 	}
139 
140 	part = findmbrfat(devfd, &dl);
141 	if (part != -1) {
142 		write_filesystem(&dl, (char)part);
143 		return;
144 	}
145 }
146 
147 static int
create_filesystem(struct disklabel * dl,char part)148 create_filesystem(struct disklabel *dl, char part)
149 {
150 	static const char *newfsfmt = "/sbin/newfs -t msdos %s >/dev/null";
151 	struct msdosfs_args args;
152 	char cmd[60];
153 	int rslt;
154 
155 	/* Newfs <duid>.<part> as msdos filesystem. */
156 	memset(&args, 0, sizeof(args));
157 	rslt = asprintf(&args.fspec,
158 	    "%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx.%c",
159             dl->d_uid[0], dl->d_uid[1], dl->d_uid[2], dl->d_uid[3],
160             dl->d_uid[4], dl->d_uid[5], dl->d_uid[6], dl->d_uid[7],
161 	    part);
162 	if (rslt == -1) {
163 		warn("bad special device");
164 		return rslt;
165 	}
166 
167 	rslt = snprintf(cmd, sizeof(cmd), newfsfmt, args.fspec);
168 	if (rslt >= sizeof(cmd)) {
169 		warnx("can't build newfs command");
170 		free(args.fspec);
171 		rslt = -1;
172 		return rslt;
173 	}
174 
175 	if (verbose)
176 		fprintf(stderr, "%s %s\n",
177 		    (nowrite ? "would newfs" : "newfsing"), args.fspec);
178 	if (!nowrite) {
179 		rslt = system(cmd);
180 		if (rslt == -1) {
181 			warn("system('%s') failed", cmd);
182 			free(args.fspec);
183 			return rslt;
184 		}
185 	}
186 
187 	free(args.fspec);
188 	return 0;
189 }
190 
191 static void
write_filesystem(struct disklabel * dl,char part)192 write_filesystem(struct disklabel *dl, char part)
193 {
194 	static const char *fsckfmt = "/sbin/fsck -t msdos %s >/dev/null";
195 	struct msdosfs_args args;
196 	char cmd[60];
197 	char dst[PATH_MAX];
198 	char *src;
199 	size_t mntlen, pathlen, srclen;
200 	int rslt;
201 
202 	src = NULL;
203 
204 	/* Create directory for temporary mount point. */
205 	strlcpy(dst, "/tmp/installboot.XXXXXXXXXX", sizeof(dst));
206 	if (mkdtemp(dst) == NULL)
207 		err(1, "mkdtemp('%s') failed", dst);
208 	mntlen = strlen(dst);
209 
210 	/* Mount <duid>.<part> as msdos filesystem. */
211 	memset(&args, 0, sizeof(args));
212 	rslt = asprintf(&args.fspec,
213 	    "%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx%02hhx.%c",
214             dl->d_uid[0], dl->d_uid[1], dl->d_uid[2], dl->d_uid[3],
215             dl->d_uid[4], dl->d_uid[5], dl->d_uid[6], dl->d_uid[7],
216 	    part);
217 	if (rslt == -1) {
218 		warn("bad special device");
219 		goto rmdir;
220 	}
221 
222 	args.export_info.ex_root = -2;
223 	args.export_info.ex_flags = 0;
224 	args.flags = MSDOSFSMNT_LONGNAME;
225 
226 	if (mount(MOUNT_MSDOS, dst, 0, &args) == -1) {
227 		/* Try fsck'ing it. */
228 		rslt = snprintf(cmd, sizeof(cmd), fsckfmt, args.fspec);
229 		if (rslt >= sizeof(cmd)) {
230 			warnx("can't build fsck command");
231 			rslt = -1;
232 			goto rmdir;
233 		}
234 		rslt = system(cmd);
235 		if (rslt == -1) {
236 			warn("system('%s') failed", cmd);
237 			goto rmdir;
238 		}
239 		if (mount(MOUNT_MSDOS, dst, 0, &args) == -1) {
240 			/* Try newfs'ing it. */
241 			rslt = create_filesystem(dl, part);
242 			if (rslt == -1)
243 				goto rmdir;
244 			rslt = mount(MOUNT_MSDOS, dst, 0, &args);
245 			if (rslt == -1) {
246 				warn("unable to mount EFI System partition");
247 				goto rmdir;
248 			}
249 		}
250 	}
251 
252 	/* Create "/efi/boot" directory in <duid>.<part>. */
253 	if (strlcat(dst, "/efi", sizeof(dst)) >= sizeof(dst)) {
254 		rslt = -1;
255 		warn("unable to build /efi directory");
256 		goto umount;
257 	}
258 	rslt = mkdir(dst, 0755);
259 	if (rslt == -1 && errno != EEXIST) {
260 		warn("mkdir('%s') failed", dst);
261 		goto umount;
262 	}
263 	if (strlcat(dst, "/boot", sizeof(dst)) >= sizeof(dst)) {
264 		rslt = -1;
265 		warn("unable to build /boot directory");
266 		goto umount;
267 	}
268 	rslt = mkdir(dst, 0755);
269 	if (rslt == -1 && errno != EEXIST) {
270 		warn("mkdir('%s') failed", dst);
271 		goto umount;
272 	}
273 
274 	/* Copy EFI bootblocks to /efi/boot/. */
275 	pathlen = strlen(dst);
276 	if (strlcat(dst, "/" BOOTEFI_DST, sizeof(dst)) >= sizeof(dst)) {
277 		rslt = -1;
278 		warn("unable to build /%s path", BOOTEFI_DST);
279 		goto umount;
280 	}
281 	src = fileprefix(root, "/usr/mdec/" BOOTEFI_SRC);
282 	if (src == NULL) {
283 		rslt = -1;
284 		goto umount;
285 	}
286 	srclen = strlen(src);
287 	if (verbose)
288 		fprintf(stderr, "%s %s to %s\n",
289 		    (nowrite ? "would copy" : "copying"), src, dst);
290 	if (!nowrite) {
291 		rslt = filecopy(src, dst);
292 		if (rslt == -1)
293 			goto umount;
294 	}
295 
296 	/* Write /efi/boot/startup.nsh. */
297 	dst[pathlen] = '\0';
298 	if (strlcat(dst, "/startup.nsh", sizeof(dst)) >= sizeof(dst)) {
299 		rslt = -1;
300 		warn("unable to build /startup.nsh path");
301 		goto umount;
302 	}
303 	if (verbose)
304 		fprintf(stderr, "%s %s\n",
305 		    (nowrite ? "would write" : "writing"), dst);
306 	if (!nowrite) {
307 		rslt = fileprintf(dst, "%s\n", BOOTEFI_DST);
308 		if (rslt == -1)
309 			goto umount;
310 	}
311 
312 	dst[mntlen] = '\0';
313 	rslt = write_firmware(root, dst);
314 	if (rslt == -1)
315 		warnx("unable to write firmware");
316 
317 umount:
318 	dst[mntlen] = '\0';
319 	if (unmount(dst, MNT_FORCE) == -1)
320 		err(1, "unmount('%s') failed", dst);
321 
322 rmdir:
323 	free(args.fspec);
324 	dst[mntlen] = '\0';
325 	if (rmdir(dst) == -1)
326 		err(1, "rmdir('%s') failed", dst);
327 
328 	free(src);
329 
330 	if (rslt == -1)
331 		exit(1);
332 }
333 
334 static int
write_firmware(const char * root,const char * mnt)335 write_firmware(const char *root, const char *mnt)
336 {
337 	char dst[PATH_MAX];
338 	char fw[PATH_MAX];
339 	char *src;
340 	struct stat st;
341 	int rslt;
342 
343 	strlcpy(dst, mnt, sizeof(dst));
344 
345 	/* Skip if no /etc/firmware exists */
346 	rslt = snprintf(fw, sizeof(fw), "%s/%s", root, "etc/firmware");
347 	if (rslt < 0 || rslt >= PATH_MAX) {
348 		warnx("unable to build /etc/firmware path");
349 		return -1;
350 	}
351 	if ((stat(fw, &st) != 0) || !S_ISDIR(st.st_mode))
352 		return 0;
353 
354 	/* Copy apple-boot firmware to /m1n1/boot.bin if available */
355 	src = fileprefix(fw, "/apple-boot.bin");
356 	if (src == NULL)
357 		return -1;
358 	if (access(src, R_OK) == 0) {
359 		if (strlcat(dst, "/m1n1", sizeof(dst)) >= sizeof(dst)) {
360 			rslt = -1;
361 			warnx("unable to build /m1n1 path");
362 			goto cleanup;
363 		}
364 		if ((stat(dst, &st) != 0) || !S_ISDIR(st.st_mode)) {
365 			rslt = 0;
366 			goto cleanup;
367 		}
368 		if (strlcat(dst, "/boot.bin", sizeof(dst)) >= sizeof(dst)) {
369 			rslt = -1;
370 			warnx("unable to build /m1n1/boot.bin path");
371 			goto cleanup;
372 		}
373 		if (verbose)
374 			fprintf(stderr, "%s %s to %s\n",
375 			    (nowrite ? "would copy" : "copying"), src, dst);
376 		if (!nowrite) {
377 			rslt = filecopy(src, dst);
378 			if (rslt == -1)
379 				goto cleanup;
380 		}
381 	}
382 	rslt = 0;
383 
384  cleanup:
385 	free(src);
386 	return rslt;
387 }
388 
389 /*
390  * Returns 0 if the MBR with the provided partition array is a GPT protective
391  * MBR, and returns 1 otherwise. A GPT protective MBR would have one and only
392  * one MBR partition, an EFI partition that either covers the whole disk or as
393  * much of it as is possible with a 32bit size field.
394  *
395  * NOTE: MS always uses a size of UINT32_MAX for the EFI partition!**
396  */
397 static int
gpt_chk_mbr(struct dos_partition * dp,u_int64_t dsize)398 gpt_chk_mbr(struct dos_partition *dp, u_int64_t dsize)
399 {
400 	struct dos_partition *dp2;
401 	int efi, found, i;
402 	u_int32_t psize;
403 
404 	found = efi = 0;
405 	for (dp2=dp, i=0; i < NDOSPART; i++, dp2++) {
406 		if (dp2->dp_typ == DOSPTYP_UNUSED)
407 			continue;
408 		found++;
409 		if (dp2->dp_typ != DOSPTYP_EFI)
410 			continue;
411 		if (letoh32(dp2->dp_start) != GPTSECTOR)
412 			continue;
413 		psize = letoh32(dp2->dp_size);
414 		if (psize <= (dsize - GPTSECTOR) || psize == UINT32_MAX)
415 			efi++;
416 	}
417 	if (found == 1 && efi == 1)
418 		return (0);
419 
420 	return (1);
421 }
422 
423 int
findgptefisys(int devfd,struct disklabel * dl)424 findgptefisys(int devfd, struct disklabel *dl)
425 {
426 	struct gpt_partition	 gp[NGPTPARTITIONS];
427 	struct gpt_header	 gh;
428 	struct dos_partition	 dp[NDOSPART];
429 	struct uuid		 efisys_uuid;
430 	const char		 efisys_uuid_code[] = GPT_UUID_EFI_SYSTEM;
431 	off_t			 off;
432 	ssize_t			 len;
433 	u_int64_t		 start;
434 	int			 i;
435 	uint32_t		 orig_csum, new_csum;
436 	uint32_t		 ghsize, ghpartsize, ghpartnum, ghpartspersec;
437 	u_int8_t		*secbuf;
438 
439 	/* Prepare EFI System UUID */
440 	uuid_dec_be(efisys_uuid_code, &efisys_uuid);
441 
442 	if ((secbuf = malloc(dl->d_secsize)) == NULL)
443 		err(1, NULL);
444 
445 	/* Check that there is a protective MBR. */
446 	len = pread(devfd, secbuf, dl->d_secsize, 0);
447 	if (len != dl->d_secsize)
448 		err(4, "can't read mbr");
449 	memcpy(dp, &secbuf[DOSPARTOFF], sizeof(dp));
450 	if (gpt_chk_mbr(dp, DL_GETDSIZE(dl))) {
451 		free(secbuf);
452 		return (-1);
453 	}
454 
455 	/* Check GPT Header. */
456 	off = dl->d_secsize;	/* Read header from sector 1. */
457 	len = pread(devfd, secbuf, dl->d_secsize, off);
458 	if (len != dl->d_secsize)
459 		err(4, "can't pread gpt header");
460 
461 	memcpy(&gh, secbuf, sizeof(gh));
462 	free(secbuf);
463 
464 	/* Check signature */
465 	if (letoh64(gh.gh_sig) != GPTSIGNATURE)
466 		return (-1);
467 
468 	if (letoh32(gh.gh_rev) != GPTREVISION)
469 		return (-1);
470 
471 	ghsize = letoh32(gh.gh_size);
472 	if (ghsize < GPTMINHDRSIZE || ghsize > sizeof(struct gpt_header))
473 		return (-1);
474 
475 	/* Check checksum */
476 	orig_csum = gh.gh_csum;
477 	gh.gh_csum = 0;
478 	new_csum = crc32((unsigned char *)&gh, ghsize);
479 	gh.gh_csum = orig_csum;
480 	if (letoh32(orig_csum) != new_csum)
481 		return (-1);
482 
483 	off = letoh64(gh.gh_part_lba) * dl->d_secsize;
484 	ghpartsize = letoh32(gh.gh_part_size);
485 	ghpartspersec = dl->d_secsize / ghpartsize;
486 	ghpartnum = letoh32(gh.gh_part_num);
487 	if ((secbuf = malloc(dl->d_secsize)) == NULL)
488 		err(1, NULL);
489 	for (i = 0; i < (ghpartnum + ghpartspersec - 1) / ghpartspersec; i++) {
490 		len = pread(devfd, secbuf, dl->d_secsize, off);
491 		if (len != dl->d_secsize) {
492 			free(secbuf);
493 			return (-1);
494 		}
495 		memcpy(gp + i * ghpartspersec, secbuf,
496 		    ghpartspersec * sizeof(struct gpt_partition));
497 		off += dl->d_secsize;
498 	}
499 	free(secbuf);
500 	new_csum = crc32((unsigned char *)&gp, ghpartnum * ghpartsize);
501 	if (new_csum != letoh32(gh.gh_part_csum))
502 		return (-1);
503 
504 	start = 0;
505 	for (i = 0; i < ghpartnum && start == 0; i++) {
506 		if (memcmp(&gp[i].gp_type, &efisys_uuid,
507 		    sizeof(struct uuid)) == 0)
508 			start = letoh64(gp[i].gp_lba_start);
509 	}
510 
511 	if (start) {
512 		for (i = 0; i < MAXPARTITIONS; i++) {
513 			if (DL_GETPSIZE(&dl->d_partitions[i]) > 0 &&
514 			    DL_GETPOFFSET(&dl->d_partitions[i]) == start)
515 				return ('a' + i);
516 		}
517 	}
518 
519 	return (-1);
520 }
521 
522 int
findmbrfat(int devfd,struct disklabel * dl)523 findmbrfat(int devfd, struct disklabel *dl)
524 {
525 	struct dos_partition	 dp[NDOSPART];
526 	ssize_t			 len;
527 	u_int64_t		 start = 0;
528 	int			 i;
529 	u_int8_t		*secbuf;
530 
531 	if ((secbuf = malloc(dl->d_secsize)) == NULL)
532 		err(1, NULL);
533 
534 	/* Read MBR. */
535 	len = pread(devfd, secbuf, dl->d_secsize, 0);
536 	if (len != dl->d_secsize)
537 		err(4, "can't read mbr");
538 	memcpy(dp, &secbuf[DOSPARTOFF], sizeof(dp));
539 
540 	for (i = 0; i < NDOSPART; i++) {
541 		if (dp[i].dp_typ == DOSPTYP_UNUSED)
542 			continue;
543 		if (dp[i].dp_typ == DOSPTYP_FAT16L ||
544 		    dp[i].dp_typ == DOSPTYP_FAT32L ||
545 		    dp[i].dp_typ == DOSPTYP_EFISYS)
546 			start = dp[i].dp_start;
547 	}
548 
549 	free(secbuf);
550 
551 	if (start) {
552 		for (i = 0; i < MAXPARTITIONS; i++) {
553 			if (DL_GETPSIZE(&dl->d_partitions[i]) > 0 &&
554 			    DL_GETPOFFSET(&dl->d_partitions[i]) == start)
555 				return ('a' + i);
556 		}
557 	}
558 
559 	return (-1);
560 }
561