xref: /freebsd/sbin/fdisk/fdisk.c (revision 70e0bbedef95258a4dadc996d641a9bebd3f107d)
1 /*
2  * Mach Operating System
3  * Copyright (c) 1992 Carnegie Mellon University
4  * All Rights Reserved.
5  *
6  * Permission to use, copy, modify and distribute this software and its
7  * documentation is hereby granted, provided that both the copyright
8  * notice and this permission notice appear in all copies of the
9  * software, derivative works or modified versions, and any portions
10  * thereof, and that both notices appear in supporting documentation.
11  *
12  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
13  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
14  * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
15  *
16  * Carnegie Mellon requests users of this software to return to
17  *
18  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
19  *  School of Computer Science
20  *  Carnegie Mellon University
21  *  Pittsburgh PA 15213-3890
22  *
23  * any improvements or extensions that they make and grant Carnegie Mellon
24  * the rights to redistribute these changes.
25  */
26 
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29 
30 #include <sys/disk.h>
31 #include <sys/disklabel.h>
32 #include <sys/diskmbr.h>
33 #include <sys/endian.h>
34 #include <sys/param.h>
35 #include <sys/stat.h>
36 #include <sys/mount.h>
37 #include <ctype.h>
38 #include <fcntl.h>
39 #include <err.h>
40 #include <errno.h>
41 #include <libgeom.h>
42 #include <paths.h>
43 #include <regex.h>
44 #include <stdint.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <unistd.h>
49 
50 static int iotest;
51 
52 #define NO_DISK_SECTORS ((u_int32_t)-1)
53 #define NO_TRACK_CYLINDERS 1023
54 #define NO_TRACK_HEADS 255
55 #define NO_TRACK_SECTORS 63
56 #define LBUF 100
57 static char lbuf[LBUF];
58 
59 /*
60  *
61  * Ported to 386bsd by Julian Elischer  Thu Oct 15 20:26:46 PDT 1992
62  *
63  * 14-Dec-89  Robert Baron (rvb) at Carnegie-Mellon University
64  *	Copyright (c) 1989	Robert. V. Baron
65  *	Created.
66  */
67 
68 #define Decimal(str, ans, tmp, maxval) if (decimal(str, &tmp, ans, maxval)) ans = tmp
69 
70 #define RoundCyl(x) ((((x) + cylsecs - 1) / cylsecs) * cylsecs)
71 
72 #define MAX_SEC_SIZE 2048	/* maximum section size that is supported */
73 #define MIN_SEC_SIZE 512	/* the sector size to start sensing at */
74 static int secsize = 0;		/* the sensed sector size */
75 
76 static char *disk;
77 
78 static int cyls, sectors, heads, cylsecs, disksecs;
79 
80 struct mboot {
81 	unsigned char *bootinst;  /* boot code */
82 	off_t bootinst_size;
83 	struct	dos_partition parts[NDOSPART];
84 };
85 
86 static struct mboot mboot;
87 static int fd;
88 
89 #define ACTIVE 0x80
90 
91 static uint dos_cyls;
92 static uint dos_heads;
93 static uint dos_sectors;
94 static uint dos_cylsecs;
95 
96 #define DOSSECT(s,c) ((s & 0x3f) | ((c >> 2) & 0xc0))
97 #define DOSCYL(c)	(c & 0xff)
98 
99 #define MAX_ARGS	10
100 
101 static int	current_line_number;
102 
103 static int	geom_processed = 0;
104 static int	part_processed = 0;
105 static int	active_processed = 0;
106 
107 typedef struct cmd {
108     char		cmd;
109     int			n_args;
110     struct arg {
111 	char		argtype;
112 	unsigned long	arg_val;
113 	char *		arg_str;
114     }			args[MAX_ARGS];
115 } CMD;
116 
117 static int B_flag  = 0;		/* replace boot code */
118 static int I_flag  = 0;		/* use entire disk for FreeBSD */
119 static int a_flag  = 0;		/* set active partition */
120 static char *b_flag = NULL;	/* path to boot code */
121 static int i_flag  = 0;		/* replace partition data */
122 static int q_flag  = 0;		/* Be quiet */
123 static int u_flag  = 0;		/* update partition data */
124 static int s_flag  = 0;		/* Print a summary and exit */
125 static int t_flag  = 0;		/* test only */
126 static char *f_flag = NULL;	/* Read config info from file */
127 static int v_flag  = 0;		/* Be verbose */
128 static int print_config_flag = 0;
129 
130 /*
131  * A list of partition types, probably outdated.
132  */
133 static const char *const part_types[256] = {
134 	[0x00] = "unused",
135 	[0x01] = "Primary DOS with 12 bit FAT",
136 	[0x02] = "XENIX / file system",
137 	[0x03] = "XENIX /usr file system",
138 	[0x04] = "Primary DOS with 16 bit FAT (< 32MB)",
139 	[0x05] = "Extended DOS",
140 	[0x06] = "Primary DOS, 16 bit FAT (>= 32MB)",
141 	[0x07] = "NTFS, OS/2 HPFS, QNX-2 (16 bit) or Advanced UNIX",
142 	[0x08] = "AIX file system or SplitDrive",
143 	[0x09] = "AIX boot partition or Coherent",
144 	[0x0A] = "OS/2 Boot Manager, OPUS or Coherent swap",
145 	[0x0B] = "DOS or Windows 95 with 32 bit FAT",
146 	[0x0C] = "DOS or Windows 95 with 32 bit FAT (LBA)",
147 	[0x0E] = "Primary 'big' DOS (>= 32MB, LBA)",
148 	[0x0F] = "Extended DOS (LBA)",
149 	[0x10] = "OPUS",
150 	[0x11] = "OS/2 BM: hidden DOS with 12-bit FAT",
151 	[0x12] = "Compaq diagnostics",
152 	[0x14] = "OS/2 BM: hidden DOS with 16-bit FAT (< 32MB)",
153 	[0x16] = "OS/2 BM: hidden DOS with 16-bit FAT (>= 32MB)",
154 	[0x17] = "OS/2 BM: hidden IFS (e.g. HPFS)",
155 	[0x18] = "AST Windows swapfile",
156 	[0x1b] = "ASUS Recovery partition (NTFS)",
157 	[0x24] = "NEC DOS",
158 	[0x3C] = "PartitionMagic recovery",
159 	[0x39] = "plan9",
160 	[0x40] = "VENIX 286",
161 	[0x41] = "Linux/MINIX (sharing disk with DRDOS)",
162 	[0x42] = "SFS or Linux swap (sharing disk with DRDOS)",
163 	[0x43] = "Linux native (sharing disk with DRDOS)",
164 	[0x4D] = "QNX 4.2 Primary",
165 	[0x4E] = "QNX 4.2 Secondary",
166 	[0x4F] = "QNX 4.2 Tertiary",
167 	[0x50] = "DM (disk manager)",
168 	[0x51] = "DM6 Aux1 (or Novell)",
169 	[0x52] = "CP/M or Microport SysV/AT",
170 	[0x53] = "DM6 Aux3",
171 	[0x54] = "DM6",
172 	[0x55] = "EZ-Drive (disk manager)",
173 	[0x56] = "Golden Bow (disk manager)",
174 	[0x5c] = "Priam Edisk (disk manager)", /* according to S. Widlake */
175 	[0x61] = "SpeedStor",
176 	[0x63] = "System V/386 (such as ISC UNIX), GNU HURD or Mach",
177 	[0x64] = "Novell Netware/286 2.xx",
178 	[0x65] = "Novell Netware/386 3.xx",
179 	[0x70] = "DiskSecure Multi-Boot",
180 	[0x75] = "PCIX",
181 	[0x77] = "QNX4.x",
182 	[0x78] = "QNX4.x 2nd part",
183 	[0x79] = "QNX4.x 3rd part",
184 	[0x80] = "Minix until 1.4a",
185 	[0x81] = "Minix since 1.4b, early Linux partition or Mitac disk manager",
186 	[0x82] = "Linux swap or Solaris x86",
187 	[0x83] = "Linux native",
188 	[0x84] = "OS/2 hidden C: drive",
189 	[0x85] = "Linux extended",
190 	[0x86] = "NTFS volume set??",
191 	[0x87] = "NTFS volume set??",
192 	[0x93] = "Amoeba file system",
193 	[0x94] = "Amoeba bad block table",
194 	[0x9F] = "BSD/OS",
195 	[0xA0] = "Suspend to Disk",
196 	[0xA5] = "FreeBSD/NetBSD/386BSD",
197 	[0xA6] = "OpenBSD",
198 	[0xA7] = "NeXTSTEP",
199 	[0xA9] = "NetBSD",
200 	[0xAC] = "IBM JFS",
201 	[0xAF] = "HFS+",
202 	[0xB7] = "BSDI BSD/386 file system",
203 	[0xB8] = "BSDI BSD/386 swap",
204 	[0xBE] = "Solaris x86 boot",
205 	[0xBF] = "Solaris x86 (new)",
206 	[0xC1] = "DRDOS/sec with 12-bit FAT",
207 	[0xC4] = "DRDOS/sec with 16-bit FAT (< 32MB)",
208 	[0xC6] = "DRDOS/sec with 16-bit FAT (>= 32MB)",
209 	[0xC7] = "Syrinx",
210 	[0xDB] = "CP/M, Concurrent CP/M, Concurrent DOS or CTOS",
211 	[0xDE] = "DELL Utilities - FAT filesystem",
212 	[0xE1] = "DOS access or SpeedStor with 12-bit FAT extended partition",
213 	[0xE3] = "DOS R/O or SpeedStor",
214 	[0xE4] = "SpeedStor with 16-bit FAT extended partition < 1024 cyl.",
215 	[0xEB] = "BeOS file system",
216 	[0xEE] = "EFI GPT",
217 	[0xEF] = "EFI System Partition",
218 	[0xF1] = "SpeedStor",
219 	[0xF2] = "DOS 3.3+ Secondary",
220 	[0xF4] = "SpeedStor large partition",
221 	[0xFE] = "SpeedStor >1024 cyl. or LANstep",
222 	[0xFF] = "Xenix bad blocks table",
223 };
224 
225 static const char *
226 get_type(int t)
227 {
228 	const char *ret;
229 
230 	ret = (t >= 0 && t <= 255) ? part_types[t] : NULL;
231 	return ret ? ret : "unknown";
232 }
233 
234 
235 static int geom_class_available(const char *);
236 static void print_s0(void);
237 static void print_part(const struct dos_partition *);
238 static void init_sector0(unsigned long start);
239 static void init_boot(void);
240 static void change_part(int i);
241 static void print_params(void);
242 static void change_active(int which);
243 static void change_code(void);
244 static void get_params_to_use(void);
245 static char *get_rootdisk(void);
246 static void dos(struct dos_partition *partp);
247 static int open_disk(int flag);
248 static ssize_t read_disk(off_t sector, void *buf);
249 static int write_disk(off_t sector, void *buf);
250 static int get_params(void);
251 static int read_s0(void);
252 static int write_s0(void);
253 static int ok(const char *str);
254 static int decimal(const char *str, int *num, int deflt, uint32_t maxval);
255 static int read_config(char *config_file);
256 static void reset_boot(void);
257 static int sanitize_partition(struct dos_partition *);
258 static void usage(void);
259 
260 int
261 main(int argc, char *argv[])
262 {
263 	int	c, i;
264 	int	partition = -1;
265 	struct	dos_partition *partp;
266 
267 	while ((c = getopt(argc, argv, "BIab:f:ipqstuv1234")) != -1)
268 		switch (c) {
269 		case 'B':
270 			B_flag = 1;
271 			break;
272 		case 'I':
273 			I_flag = 1;
274 			break;
275 		case 'a':
276 			a_flag = 1;
277 			break;
278 		case 'b':
279 			b_flag = optarg;
280 			break;
281 		case 'f':
282 			f_flag = optarg;
283 			break;
284 		case 'i':
285 			i_flag = 1;
286 			break;
287 		case 'p':
288 			print_config_flag = 1;
289 			break;
290 		case 'q':
291 			q_flag = 1;
292 			break;
293 		case 's':
294 			s_flag = 1;
295 			break;
296 		case 't':
297 			t_flag = 1;
298 			break;
299 		case 'u':
300 			u_flag = 1;
301 			break;
302 		case 'v':
303 			v_flag = 1;
304 			break;
305 		case '1':
306 		case '2':
307 		case '3':
308 		case '4':
309 			partition = c - '0';
310 			break;
311 		default:
312 			usage();
313 		}
314 	if (f_flag || i_flag)
315 		u_flag = 1;
316 	if (t_flag)
317 		v_flag = 1;
318 	argc -= optind;
319 	argv += optind;
320 
321 	if (argc == 0) {
322 		disk = get_rootdisk();
323 	} else {
324 		disk = g_device_path(argv[0]);
325 		if (disk == NULL)
326 			err(1, "unable to get correct path for %s", argv[0]);
327 	}
328 	if (open_disk(u_flag) < 0)
329 		err(1, "cannot open disk %s", disk);
330 
331 	/* (abu)use mboot.bootinst to probe for the sector size */
332 	if ((mboot.bootinst = malloc(MAX_SEC_SIZE)) == NULL)
333 		err(1, "cannot allocate buffer to determine disk sector size");
334 	if (read_disk(0, mboot.bootinst) == -1)
335 		errx(1, "could not detect sector size");
336 	free(mboot.bootinst);
337 	mboot.bootinst = NULL;
338 
339 	if (print_config_flag) {
340 		if (read_s0())
341 			err(1, "read_s0");
342 
343 		printf("# %s\n", disk);
344 		printf("g c%d h%d s%d\n", dos_cyls, dos_heads, dos_sectors);
345 
346 		for (i = 0; i < NDOSPART; i++) {
347 			partp = &mboot.parts[i];
348 
349 			if (partp->dp_start == 0 && partp->dp_size == 0)
350 				continue;
351 
352 			printf("p %d 0x%02x %lu %lu\n", i + 1, partp->dp_typ,
353 			    (u_long)partp->dp_start, (u_long)partp->dp_size);
354 
355 			/* Fill flags for the partition. */
356 			if (partp->dp_flag & 0x80)
357 				printf("a %d\n", i + 1);
358 		}
359 		exit(0);
360 	}
361 	if (s_flag) {
362 		if (read_s0())
363 			err(1, "read_s0");
364 		printf("%s: %d cyl %d hd %d sec\n", disk, dos_cyls, dos_heads,
365 		    dos_sectors);
366 		printf("Part  %11s %11s Type Flags\n", "Start", "Size");
367 		for (i = 0; i < NDOSPART; i++) {
368 			partp = &mboot.parts[i];
369 			if (partp->dp_start == 0 && partp->dp_size == 0)
370 				continue;
371 			printf("%4d: %11lu %11lu 0x%02x 0x%02x\n", i + 1,
372 			    (u_long) partp->dp_start,
373 			    (u_long) partp->dp_size, partp->dp_typ,
374 			    partp->dp_flag);
375 		}
376 		exit(0);
377 	}
378 
379 	printf("******* Working on device %s *******\n",disk);
380 
381 	if (I_flag) {
382 		read_s0();
383 		reset_boot();
384 		partp = &mboot.parts[0];
385 		partp->dp_typ = DOSPTYP_386BSD;
386 		partp->dp_flag = ACTIVE;
387 		partp->dp_start = dos_sectors;
388 		partp->dp_size = (disksecs / dos_cylsecs) * dos_cylsecs -
389 		    dos_sectors;
390 		dos(partp);
391 		if (v_flag)
392 			print_s0();
393 		if (!t_flag)
394 			write_s0();
395 		exit(0);
396 	}
397 	if (f_flag) {
398 	    if (read_s0() || i_flag)
399 		reset_boot();
400 	    if (!read_config(f_flag))
401 		exit(1);
402 	    if (v_flag)
403 		print_s0();
404 	    if (!t_flag)
405 		write_s0();
406 	} else {
407 	    if(u_flag)
408 		get_params_to_use();
409 	    else
410 		print_params();
411 
412 	    if (read_s0())
413 		init_sector0(dos_sectors);
414 
415 	    printf("Media sector size is %d\n", secsize);
416 	    printf("Warning: BIOS sector numbering starts with sector 1\n");
417 	    printf("Information from DOS bootblock is:\n");
418 	    if (partition == -1)
419 		for (i = 1; i <= NDOSPART; i++)
420 		    change_part(i);
421 	    else
422 		change_part(partition);
423 
424 	    if (u_flag || a_flag)
425 		change_active(partition);
426 
427 	    if (B_flag)
428 		change_code();
429 
430 	    if (u_flag || a_flag || B_flag) {
431 		if (!t_flag) {
432 		    printf("\nWe haven't changed the partition table yet.  ");
433 		    printf("This is your last chance.\n");
434 		}
435 		print_s0();
436 		if (!t_flag) {
437 		    if (ok("Should we write new partition table?"))
438 			write_s0();
439 		} else {
440 		    printf("\n-t flag specified -- partition table not written.\n");
441 		}
442 	    }
443 	}
444 
445 	exit(0);
446 }
447 
448 static void
449 usage()
450 {
451 	fprintf(stderr, "%s%s",
452 		"usage: fdisk [-BIaipqstu] [-b bootcode] [-1234] [disk]\n",
453  		"       fdisk -f configfile [-itv] [disk]\n");
454         exit(1);
455 }
456 
457 static void
458 print_s0(void)
459 {
460 	int	i;
461 
462 	print_params();
463 	printf("Information from DOS bootblock is:\n");
464 	for (i = 1; i <= NDOSPART; i++) {
465 		printf("%d: ", i);
466 		print_part(&mboot.parts[i - 1]);
467 	}
468 }
469 
470 static struct dos_partition mtpart;
471 
472 static void
473 print_part(const struct dos_partition *partp)
474 {
475 	u_int64_t part_mb;
476 
477 	if (!bcmp(partp, &mtpart, sizeof (struct dos_partition))) {
478 		printf("<UNUSED>\n");
479 		return;
480 	}
481 	/*
482 	 * Be careful not to overflow.
483 	 */
484 	part_mb = partp->dp_size;
485 	part_mb *= secsize;
486 	part_mb /= (1024 * 1024);
487 	printf("sysid %d (%#04x),(%s)\n", partp->dp_typ, partp->dp_typ,
488 	    get_type(partp->dp_typ));
489 	printf("    start %lu, size %lu (%ju Meg), flag %x%s\n",
490 		(u_long)partp->dp_start,
491 		(u_long)partp->dp_size,
492 		(uintmax_t)part_mb,
493 		partp->dp_flag,
494 		partp->dp_flag == ACTIVE ? " (active)" : "");
495 	printf("\tbeg: cyl %d/ head %d/ sector %d;\n\tend: cyl %d/ head %d/ sector %d\n"
496 		,DPCYL(partp->dp_scyl, partp->dp_ssect)
497 		,partp->dp_shd
498 		,DPSECT(partp->dp_ssect)
499 		,DPCYL(partp->dp_ecyl, partp->dp_esect)
500 		,partp->dp_ehd
501 		,DPSECT(partp->dp_esect));
502 }
503 
504 
505 static void
506 init_boot(void)
507 {
508 #ifndef __ia64__
509 	const char *fname;
510 	int fdesc, n;
511 	struct stat sb;
512 
513 	fname = b_flag ? b_flag : "/boot/mbr";
514 	if ((fdesc = open(fname, O_RDONLY)) == -1 ||
515 	    fstat(fdesc, &sb) == -1)
516 		err(1, "%s", fname);
517 	if (sb.st_size == 0)
518 		errx(1, "%s is empty, must not be.", fname);
519 	if ((mboot.bootinst_size = sb.st_size) % secsize != 0)
520 		errx(1, "%s: length must be a multiple of sector size", fname);
521 	if (mboot.bootinst != NULL)
522 		free(mboot.bootinst);
523 	if ((mboot.bootinst = malloc(mboot.bootinst_size = sb.st_size)) == NULL)
524 		errx(1, "%s: unable to allocate read buffer", fname);
525 	if ((n = read(fdesc, mboot.bootinst, mboot.bootinst_size)) == -1 ||
526 	    close(fdesc))
527 		err(1, "%s", fname);
528 	if (n != mboot.bootinst_size)
529 		errx(1, "%s: short read", fname);
530 #else
531 	if (mboot.bootinst != NULL)
532 		free(mboot.bootinst);
533 	mboot.bootinst_size = secsize;
534 	if ((mboot.bootinst = malloc(mboot.bootinst_size)) == NULL)
535 		errx(1, "unable to allocate boot block buffer");
536 	memset(mboot.bootinst, 0, mboot.bootinst_size);
537 	le16enc(&mboot.bootinst[DOSMAGICOFFSET], DOSMAGIC);
538 #endif
539 }
540 
541 
542 static void
543 init_sector0(unsigned long start)
544 {
545 	struct dos_partition *partp = &mboot.parts[0];
546 
547 	init_boot();
548 
549 	partp->dp_typ = DOSPTYP_386BSD;
550 	partp->dp_flag = ACTIVE;
551 	start = ((start + dos_sectors - 1) / dos_sectors) * dos_sectors;
552 	if(start == 0)
553 		start = dos_sectors;
554 	partp->dp_start = start;
555 	partp->dp_size = (disksecs / dos_cylsecs) * dos_cylsecs - start;
556 
557 	dos(partp);
558 }
559 
560 static void
561 change_part(int i)
562 {
563     struct dos_partition *partp = &mboot.parts[i - 1];
564 
565     printf("The data for partition %d is:\n", i);
566     print_part(partp);
567 
568     if (u_flag && ok("Do you want to change it?")) {
569 	int tmp;
570 
571 	if (i_flag) {
572 	    bzero(partp, sizeof (*partp));
573 	    if (i == 1) {
574 		init_sector0(1);
575 		printf("\nThe static data for the slice 1 has been reinitialized to:\n");
576 		print_part(partp);
577 	    }
578 	}
579 
580 	do {
581 		Decimal("sysid (165=FreeBSD)", partp->dp_typ, tmp, 255);
582 		Decimal("start", partp->dp_start, tmp, NO_DISK_SECTORS);
583 		Decimal("size", partp->dp_size, tmp, NO_DISK_SECTORS);
584 		if (!sanitize_partition(partp)) {
585 			warnx("ERROR: failed to adjust; setting sysid to 0");
586 			partp->dp_typ = 0;
587 		}
588 
589 		if (ok("Explicitly specify beg/end address ?"))
590 		{
591 			int	tsec,tcyl,thd;
592 			tcyl = DPCYL(partp->dp_scyl,partp->dp_ssect);
593 			thd = partp->dp_shd;
594 			tsec = DPSECT(partp->dp_ssect);
595 			Decimal("beginning cylinder", tcyl, tmp, NO_TRACK_CYLINDERS);
596 			Decimal("beginning head", thd, tmp, NO_TRACK_HEADS);
597 			Decimal("beginning sector", tsec, tmp, NO_TRACK_SECTORS);
598 			partp->dp_scyl = DOSCYL(tcyl);
599 			partp->dp_ssect = DOSSECT(tsec,tcyl);
600 			partp->dp_shd = thd;
601 
602 			tcyl = DPCYL(partp->dp_ecyl,partp->dp_esect);
603 			thd = partp->dp_ehd;
604 			tsec = DPSECT(partp->dp_esect);
605 			Decimal("ending cylinder", tcyl, tmp, NO_TRACK_CYLINDERS);
606 			Decimal("ending head", thd, tmp, NO_TRACK_HEADS);
607 			Decimal("ending sector", tsec, tmp, NO_TRACK_SECTORS);
608 			partp->dp_ecyl = DOSCYL(tcyl);
609 			partp->dp_esect = DOSSECT(tsec,tcyl);
610 			partp->dp_ehd = thd;
611 		} else
612 			dos(partp);
613 
614 		print_part(partp);
615 	} while (!ok("Are we happy with this entry?"));
616     }
617 }
618 
619 static void
620 print_params()
621 {
622 	printf("parameters extracted from in-core disklabel are:\n");
623 	printf("cylinders=%d heads=%d sectors/track=%d (%d blks/cyl)\n\n"
624 			,cyls,heads,sectors,cylsecs);
625 	if (dos_cyls > 1023 || dos_heads > 255 || dos_sectors > 63)
626 		printf("Figures below won't work with BIOS for partitions not in cyl 1\n");
627 	printf("parameters to be used for BIOS calculations are:\n");
628 	printf("cylinders=%d heads=%d sectors/track=%d (%d blks/cyl)\n\n"
629 		,dos_cyls,dos_heads,dos_sectors,dos_cylsecs);
630 }
631 
632 static void
633 change_active(int which)
634 {
635 	struct dos_partition *partp = &mboot.parts[0];
636 	int active, i, new, tmp;
637 
638 	active = -1;
639 	for (i = 0; i < NDOSPART; i++) {
640 		if ((partp[i].dp_flag & ACTIVE) == 0)
641 			continue;
642 		printf("Partition %d is marked active\n", i + 1);
643 		if (active == -1)
644 			active = i + 1;
645 	}
646 	if (a_flag && which != -1)
647 		active = which;
648 	else if (active == -1)
649 		active = 1;
650 
651 	if (!ok("Do you want to change the active partition?"))
652 		return;
653 setactive:
654 	do {
655 		new = active;
656 		Decimal("active partition", new, tmp, 0);
657 		if (new < 1 || new > 4) {
658 			printf("Active partition number must be in range 1-4."
659 					"  Try again.\n");
660 			goto setactive;
661 		}
662 		active = new;
663 	} while (!ok("Are you happy with this choice"));
664 	for (i = 0; i < NDOSPART; i++)
665 		partp[i].dp_flag = 0;
666 	if (active > 0 && active <= NDOSPART)
667 		partp[active-1].dp_flag = ACTIVE;
668 }
669 
670 static void
671 change_code()
672 {
673 	if (ok("Do you want to change the boot code?"))
674 		init_boot();
675 }
676 
677 void
678 get_params_to_use()
679 {
680 	int	tmp;
681 	print_params();
682 	if (ok("Do you want to change our idea of what BIOS thinks ?"))
683 	{
684 		do
685 		{
686 			Decimal("BIOS's idea of #cylinders", dos_cyls, tmp, 0);
687 			Decimal("BIOS's idea of #heads", dos_heads, tmp, 0);
688 			Decimal("BIOS's idea of #sectors", dos_sectors, tmp, 0);
689 			dos_cylsecs = dos_heads * dos_sectors;
690 			print_params();
691 		}
692 		while(!ok("Are you happy with this choice"));
693 	}
694 }
695 
696 
697 /***********************************************\
698 * Change real numbers into strange dos numbers	*
699 \***********************************************/
700 static void
701 dos(struct dos_partition *partp)
702 {
703 	int cy, sec;
704 	u_int32_t end;
705 
706 	if (partp->dp_typ == 0 && partp->dp_start == 0 && partp->dp_size == 0) {
707 		memcpy(partp, &mtpart, sizeof(*partp));
708 		return;
709 	}
710 
711 	/* Start c/h/s. */
712 	partp->dp_shd = partp->dp_start % dos_cylsecs / dos_sectors;
713 	cy = partp->dp_start / dos_cylsecs;
714 	sec = partp->dp_start % dos_sectors + 1;
715 	partp->dp_scyl = DOSCYL(cy);
716 	partp->dp_ssect = DOSSECT(sec, cy);
717 
718 	/* End c/h/s. */
719 	end = partp->dp_start + partp->dp_size - 1;
720 	partp->dp_ehd = end % dos_cylsecs / dos_sectors;
721 	cy = end / dos_cylsecs;
722 	sec = end % dos_sectors + 1;
723 	partp->dp_ecyl = DOSCYL(cy);
724 	partp->dp_esect = DOSSECT(sec, cy);
725 }
726 
727 static int
728 open_disk(int flag)
729 {
730 	int rwmode;
731 
732 	/* Write mode if one of these flags are set. */
733 	rwmode = (a_flag || I_flag || B_flag || flag);
734 	fd = g_open(disk, rwmode);
735 	/* If the mode fails, try read-only if we didn't. */
736 	if (fd == -1 && errno == EPERM && rwmode)
737 		fd = g_open(disk, 0);
738 	if (fd == -1 && errno == ENXIO)
739 		return -2;
740 	if (fd == -1) {
741 		warnx("can't open device %s", disk);
742 		return -1;
743 	}
744 	if (get_params() == -1) {
745 		warnx("can't get disk parameters on %s", disk);
746 		return -1;
747 	}
748 	return fd;
749 }
750 
751 static ssize_t
752 read_disk(off_t sector, void *buf)
753 {
754 
755 	lseek(fd, (sector * 512), 0);
756 	if (secsize == 0)
757 		for (secsize = MIN_SEC_SIZE; secsize <= MAX_SEC_SIZE;
758 		     secsize *= 2) {
759 			/* try the read */
760 			int size = read(fd, buf, secsize);
761 			if (size == secsize)
762 				/* it worked so return */
763 				return secsize;
764 		}
765 	else
766 		return read(fd, buf, secsize);
767 
768 	/* we failed to read at any of the sizes */
769 	return -1;
770 }
771 
772 static int
773 geom_class_available(const char *name)
774 {
775 	struct gclass *class;
776 	struct gmesh mesh;
777 	int error;
778 
779 	error = geom_gettree(&mesh);
780 	if (error != 0)
781 		errc(1, error, "Cannot get GEOM tree");
782 
783 	LIST_FOREACH(class, &mesh.lg_class, lg_class) {
784 		if (strcmp(class->lg_name, name) == 0) {
785 			geom_deletetree(&mesh);
786 			return (1);
787 		}
788 	}
789 
790 	geom_deletetree(&mesh);
791 
792 	return (0);
793 }
794 
795 static int
796 write_disk(off_t sector, void *buf)
797 {
798 	struct gctl_req *grq;
799 	const char *errmsg;
800 	char *pname;
801 	int error;
802 
803 	/* Check that GEOM_MBR is available */
804 	if (geom_class_available("MBR") != 0) {
805 		grq = gctl_get_handle();
806 		gctl_ro_param(grq, "verb", -1, "write MBR");
807 		gctl_ro_param(grq, "class", -1, "MBR");
808 		pname = g_providername(fd);
809 		if (pname == NULL) {
810 			warn("Error getting providername for %s", disk);
811 			return (-1);
812 		}
813 		gctl_ro_param(grq, "geom", -1, pname);
814 		gctl_ro_param(grq, "data", secsize, buf);
815 		errmsg = gctl_issue(grq);
816 		free(pname);
817 		if (errmsg == NULL) {
818 			gctl_free(grq);
819 			return(0);
820 		}
821 		if (!q_flag)
822 			warnx("GEOM_MBR: %s", errmsg);
823 		gctl_free(grq);
824 	} else {
825 		/*
826 		 * Try to write MBR directly. This may help when disk
827 		 * is not in use.
828 		 * XXX: hardcoded sectorsize
829 		 */
830 		error = pwrite(fd, buf, secsize, (sector * 512));
831 		if (error == secsize)
832 			return (0);
833 	}
834 
835 	/*
836 	 * GEOM_MBR is not available or failed to write MBR.
837 	 * Now check that we have GEOM_PART and recommend to use gpart (8).
838 	 */
839 	if (geom_class_available("PART") != 0)
840 		warnx("Failed to write MBR. Try to use gpart(8).");
841 	else
842 		warnx("Failed to write sector zero");
843 	return(EINVAL);
844 }
845 
846 static int
847 get_params()
848 {
849 	int error;
850 	u_int u;
851 	off_t o;
852 
853 	error = ioctl(fd, DIOCGFWSECTORS, &u);
854 	if (error == 0)
855 		sectors = dos_sectors = u;
856 	else
857 		sectors = dos_sectors = 63;
858 
859 	error = ioctl(fd, DIOCGFWHEADS, &u);
860 	if (error == 0)
861 		heads = dos_heads = u;
862 	else
863 		heads = dos_heads = 255;
864 
865 	dos_cylsecs = cylsecs = heads * sectors;
866 	disksecs = cyls * heads * sectors;
867 
868 	u = g_sectorsize(fd);
869 	if (u <= 0)
870 		return (-1);
871 
872 	o = g_mediasize(fd);
873 	if (o < 0)
874 		return (-1);
875 	disksecs = o / u;
876 	cyls = dos_cyls = o / (u * dos_heads * dos_sectors);
877 
878 	return (disksecs);
879 }
880 
881 static int
882 read_s0()
883 {
884 	int i;
885 
886 	mboot.bootinst_size = secsize;
887 	if (mboot.bootinst != NULL)
888 		free(mboot.bootinst);
889 	if ((mboot.bootinst = malloc(mboot.bootinst_size)) == NULL) {
890 		warnx("unable to allocate buffer to read fdisk "
891 		      "partition table");
892 		return -1;
893 	}
894 	if (read_disk(0, mboot.bootinst) == -1) {
895 		warnx("can't read fdisk partition table");
896 		return -1;
897 	}
898 	if (le16dec(&mboot.bootinst[DOSMAGICOFFSET]) != DOSMAGIC) {
899 		warnx("invalid fdisk partition table found");
900 		/* So should we initialize things */
901 		return -1;
902 	}
903 	for (i = 0; i < NDOSPART; i++)
904 		dos_partition_dec(
905 		    &mboot.bootinst[DOSPARTOFF + i * DOSPARTSIZE],
906 		    &mboot.parts[i]);
907 	return 0;
908 }
909 
910 static int
911 write_s0()
912 {
913 	int	sector, i;
914 
915 	if (iotest) {
916 		print_s0();
917 		return 0;
918 	}
919 	for(i = 0; i < NDOSPART; i++)
920 		dos_partition_enc(&mboot.bootinst[DOSPARTOFF + i * DOSPARTSIZE],
921 		    &mboot.parts[i]);
922 	le16enc(&mboot.bootinst[DOSMAGICOFFSET], DOSMAGIC);
923 	for(sector = 0; sector < mboot.bootinst_size / secsize; sector++)
924 		if (write_disk(sector,
925 			       &mboot.bootinst[sector * secsize]) == -1) {
926 			warn("can't write fdisk partition table");
927 			return -1;
928 		}
929 	return(0);
930 }
931 
932 
933 static int
934 ok(const char *str)
935 {
936 	printf("%s [n] ", str);
937 	fflush(stdout);
938 	if (fgets(lbuf, LBUF, stdin) == NULL)
939 		exit(1);
940 	lbuf[strlen(lbuf)-1] = 0;
941 
942 	if (*lbuf &&
943 		(!strcmp(lbuf, "yes") || !strcmp(lbuf, "YES") ||
944 		 !strcmp(lbuf, "y") || !strcmp(lbuf, "Y")))
945 		return 1;
946 	else
947 		return 0;
948 }
949 
950 static int
951 decimal(const char *str, int *num, int deflt, uint32_t maxval)
952 {
953 	long long acc;
954 	int c;
955 	char *cp;
956 
957 	while (1) {
958 		acc = 0;
959 		printf("Supply a decimal value for \"%s\" [%d] ", str, deflt);
960 		fflush(stdout);
961 		if (fgets(lbuf, LBUF, stdin) == NULL)
962 			exit(1);
963 		lbuf[strlen(lbuf)-1] = 0;
964 
965 		if (!*lbuf)
966 			return 0;
967 
968 		cp = lbuf;
969 		while ((c = *cp) && (c == ' ' || c == '\t')) cp++;
970 		if (!c)
971 			return 0;
972 		while ((c = *cp++)) {
973 			if (c <= '9' && c >= '0') {
974 				if (acc <= maxval || maxval == 0)
975 					acc = acc * 10 + c - '0';
976 			} else
977 				break;
978 		}
979 		if (c == ' ' || c == '\t')
980 			while ((c = *cp) && (c == ' ' || c == '\t')) cp++;
981 		if (!c) {
982 			if (maxval > 0 && acc > maxval) {
983 				acc = maxval;
984 				printf("%s exceeds maximum value allowed for "
985 				  "this field. The value has been reduced "
986 				  "to %lld\n", lbuf, acc);
987 			}
988 			*num = acc;
989 			return 1;
990 		} else
991 			printf("%s is an invalid decimal number.  Try again.\n",
992 				lbuf);
993 	}
994 }
995 
996 
997 static void
998 parse_config_line(char *line, CMD *command)
999 {
1000     char	*cp, *end;
1001 
1002     cp = line;
1003     while (1) {
1004 	memset(command, 0, sizeof(*command));
1005 
1006 	while (isspace(*cp)) ++cp;
1007 	if (*cp == '\0' || *cp == '#')
1008 	    break;
1009 	command->cmd = *cp++;
1010 
1011 	/*
1012 	 * Parse args
1013 	 */
1014 	    while (1) {
1015 	    while (isspace(*cp)) ++cp;
1016 	    if (*cp == '\0')
1017 		break;		/* eol */
1018 	    if (*cp == '#')
1019 		break;		/* found comment */
1020 	    if (isalpha(*cp))
1021 		command->args[command->n_args].argtype = *cp++;
1022 	    end = NULL;
1023 	    command->args[command->n_args].arg_val = strtoul(cp, &end, 0);
1024  	    if (cp == end || (!isspace(*end) && *end != '\0')) {
1025  		char ch;
1026  		end = cp;
1027  		while (!isspace(*end) && *end != '\0') ++end;
1028  		ch = *end; *end = '\0';
1029  		command->args[command->n_args].arg_str = strdup(cp);
1030  		*end = ch;
1031  	    } else
1032  		command->args[command->n_args].arg_str = NULL;
1033 	    cp = end;
1034 	    command->n_args++;
1035 	}
1036 	break;
1037     }
1038 }
1039 
1040 
1041 static int
1042 process_geometry(CMD *command)
1043 {
1044     int		status = 1, i;
1045 
1046     while (1) {
1047 	geom_processed = 1;
1048 	    if (part_processed) {
1049 	    warnx(
1050 	"ERROR line %d: the geometry specification line must occur before\n\
1051     all partition specifications",
1052 		    current_line_number);
1053 	    status = 0;
1054 	    break;
1055 	}
1056 	    if (command->n_args != 3) {
1057 	    warnx("ERROR line %d: incorrect number of geometry args",
1058 		    current_line_number);
1059 	    status = 0;
1060 	    break;
1061 	}
1062 	    dos_cyls = 0;
1063 	    dos_heads = 0;
1064 	    dos_sectors = 0;
1065 	    for (i = 0; i < 3; ++i) {
1066 		    switch (command->args[i].argtype) {
1067 	    case 'c':
1068 		dos_cyls = command->args[i].arg_val;
1069 		break;
1070 	    case 'h':
1071 		dos_heads = command->args[i].arg_val;
1072 		break;
1073 	    case 's':
1074 		dos_sectors = command->args[i].arg_val;
1075 		break;
1076 	    default:
1077 		warnx(
1078 		"ERROR line %d: unknown geometry arg type: '%c' (0x%02x)",
1079 			current_line_number, command->args[i].argtype,
1080 			command->args[i].argtype);
1081 		status = 0;
1082 		break;
1083 	    }
1084 	}
1085 	if (status == 0)
1086 	    break;
1087 
1088 	dos_cylsecs = dos_heads * dos_sectors;
1089 
1090 	/*
1091 	 * Do sanity checks on parameter values
1092 	 */
1093 	    if (dos_cyls == 0) {
1094 	    warnx("ERROR line %d: number of cylinders not specified",
1095 		    current_line_number);
1096 	    status = 0;
1097 	}
1098 	    if (dos_cyls > 1024) {
1099 	    warnx(
1100 	"WARNING line %d: number of cylinders (%d) may be out-of-range\n\
1101     (must be within 1-1024 for normal BIOS operation, unless the entire disk\n\
1102     is dedicated to FreeBSD)",
1103 		    current_line_number, dos_cyls);
1104 	}
1105 
1106 	    if (dos_heads == 0) {
1107 	    warnx("ERROR line %d: number of heads not specified",
1108 		    current_line_number);
1109 	    status = 0;
1110 	    } else if (dos_heads > 256) {
1111 	    warnx("ERROR line %d: number of heads must be within (1-256)",
1112 		    current_line_number);
1113 	    status = 0;
1114 	}
1115 
1116 	    if (dos_sectors == 0) {
1117 	    warnx("ERROR line %d: number of sectors not specified",
1118 		    current_line_number);
1119 	    status = 0;
1120 	    } else if (dos_sectors > 63) {
1121 	    warnx("ERROR line %d: number of sectors must be within (1-63)",
1122 		    current_line_number);
1123 	    status = 0;
1124 	}
1125 
1126 	break;
1127     }
1128     return (status);
1129 }
1130 
1131 static u_int32_t
1132 str2sectors(const char *str)
1133 {
1134 	char *end;
1135 	unsigned long val;
1136 
1137 	val = strtoul(str, &end, 0);
1138 	if (str == end || *end == '\0') {
1139 		warnx("ERROR line %d: unexpected size: \'%s\'",
1140 		    current_line_number, str);
1141 		return NO_DISK_SECTORS;
1142 	}
1143 
1144 	if (*end == 'K')
1145 		val *= 1024UL / secsize;
1146 	else if (*end == 'M')
1147 		val *= 1024UL * 1024UL / secsize;
1148 	else if (*end == 'G')
1149 		val *= 1024UL * 1024UL * 1024UL / secsize;
1150 	else {
1151 		warnx("ERROR line %d: unexpected modifier: %c "
1152 		    "(not K/M/G)", current_line_number, *end);
1153 		return NO_DISK_SECTORS;
1154 	}
1155 
1156 	return val;
1157 }
1158 
1159 static int
1160 process_partition(CMD *command)
1161 {
1162     int				status = 0, partition;
1163     u_int32_t			prev_head_boundary, prev_cyl_boundary;
1164     u_int32_t			adj_size, max_end;
1165     struct dos_partition	*partp;
1166 
1167 	while (1) {
1168 	part_processed = 1;
1169 		if (command->n_args != 4) {
1170 	    warnx("ERROR line %d: incorrect number of partition args",
1171 		    current_line_number);
1172 	    break;
1173 	}
1174 	partition = command->args[0].arg_val;
1175 		if (partition < 1 || partition > 4) {
1176 	    warnx("ERROR line %d: invalid partition number %d",
1177 		    current_line_number, partition);
1178 	    break;
1179 	}
1180 	partp = &mboot.parts[partition - 1];
1181 	bzero(partp, sizeof (*partp));
1182 	partp->dp_typ = command->args[1].arg_val;
1183 	if (command->args[2].arg_str != NULL) {
1184 		if (strcmp(command->args[2].arg_str, "*") == 0) {
1185 			int i;
1186 			partp->dp_start = dos_sectors;
1187 			for (i = 1; i < partition; i++) {
1188     				struct dos_partition *prev_partp;
1189 				prev_partp = ((struct dos_partition *)
1190 				    &mboot.parts) + i - 1;
1191 				if (prev_partp->dp_typ != 0)
1192 					partp->dp_start = prev_partp->dp_start +
1193 					    prev_partp->dp_size;
1194 			}
1195 			if (partp->dp_start % dos_sectors != 0) {
1196 		    		prev_head_boundary = partp->dp_start /
1197 				    dos_sectors * dos_sectors;
1198 		    		partp->dp_start = prev_head_boundary +
1199 				    dos_sectors;
1200 			}
1201 		} else {
1202 			partp->dp_start = str2sectors(command->args[2].arg_str);
1203 			if (partp->dp_start == NO_DISK_SECTORS)
1204 				break;
1205 		}
1206 	} else
1207 		partp->dp_start = command->args[2].arg_val;
1208 
1209 	if (command->args[3].arg_str != NULL) {
1210 		if (strcmp(command->args[3].arg_str, "*") == 0)
1211 			partp->dp_size = ((disksecs / dos_cylsecs) *
1212 			    dos_cylsecs) - partp->dp_start;
1213 		else {
1214 			partp->dp_size = str2sectors(command->args[3].arg_str);
1215 			if (partp->dp_size == NO_DISK_SECTORS)
1216 				break;
1217 		}
1218 		prev_cyl_boundary = ((partp->dp_start + partp->dp_size) /
1219 		    dos_cylsecs) * dos_cylsecs;
1220 		if (prev_cyl_boundary > partp->dp_start)
1221 			partp->dp_size = prev_cyl_boundary - partp->dp_start;
1222 	} else
1223 		partp->dp_size = command->args[3].arg_val;
1224 
1225 	max_end = partp->dp_start + partp->dp_size;
1226 
1227 	if (partp->dp_typ == 0) {
1228 	    /*
1229 	     * Get out, the partition is marked as unused.
1230 	     */
1231 	    /*
1232 	     * Insure that it's unused.
1233 	     */
1234 	    bzero(partp, sizeof(*partp));
1235 	    status = 1;
1236 	    break;
1237 	}
1238 
1239 	/*
1240 	 * Adjust start upwards, if necessary, to fall on a head boundary.
1241 	 */
1242 		if (partp->dp_start % dos_sectors != 0) {
1243 	    prev_head_boundary = partp->dp_start / dos_sectors * dos_sectors;
1244 	    if (max_end < dos_sectors ||
1245 			    prev_head_boundary > max_end - dos_sectors) {
1246 		/*
1247 		 * Can't go past end of partition
1248 		 */
1249 		warnx(
1250 	"ERROR line %d: unable to adjust start of partition %d to fall on\n\
1251     a head boundary",
1252 			current_line_number, partition);
1253 		break;
1254 	    }
1255 	    warnx(
1256 	"WARNING: adjusting start offset of partition %d\n\
1257     from %u to %u, to fall on a head boundary",
1258 		    partition, (u_int)partp->dp_start,
1259 		    (u_int)(prev_head_boundary + dos_sectors));
1260 	    partp->dp_start = prev_head_boundary + dos_sectors;
1261 	}
1262 
1263 	/*
1264 	 * Adjust size downwards, if necessary, to fall on a cylinder
1265 	 * boundary.
1266 	 */
1267 	prev_cyl_boundary =
1268 	    ((partp->dp_start + partp->dp_size) / dos_cylsecs) * dos_cylsecs;
1269 	if (prev_cyl_boundary > partp->dp_start)
1270 	    adj_size = prev_cyl_boundary - partp->dp_start;
1271 		else {
1272 	    warnx(
1273 	"ERROR: could not adjust partition to start on a head boundary\n\
1274     and end on a cylinder boundary.");
1275 	    return (0);
1276 	}
1277 		if (adj_size != partp->dp_size) {
1278 	    warnx(
1279 	"WARNING: adjusting size of partition %d from %u to %u\n\
1280     to end on a cylinder boundary",
1281 		    partition, (u_int)partp->dp_size, (u_int)adj_size);
1282 	    partp->dp_size = adj_size;
1283 	}
1284 		if (partp->dp_size == 0) {
1285 	    warnx("ERROR line %d: size of partition %d is zero",
1286 		    current_line_number, partition);
1287 	    break;
1288 	}
1289 
1290 	dos(partp);
1291 	status = 1;
1292 	break;
1293     }
1294     return (status);
1295 }
1296 
1297 
1298 static int
1299 process_active(CMD *command)
1300 {
1301     int				status = 0, partition, i;
1302     struct dos_partition	*partp;
1303 
1304 	while (1) {
1305 	active_processed = 1;
1306 		if (command->n_args != 1) {
1307 	    warnx("ERROR line %d: incorrect number of active args",
1308 		    current_line_number);
1309 	    status = 0;
1310 	    break;
1311 	}
1312 	partition = command->args[0].arg_val;
1313 		if (partition < 1 || partition > 4) {
1314 	    warnx("ERROR line %d: invalid partition number %d",
1315 		    current_line_number, partition);
1316 	    break;
1317 	}
1318 	/*
1319 	 * Reset active partition
1320 	 */
1321 	partp = mboot.parts;
1322 	for (i = 0; i < NDOSPART; i++)
1323 	    partp[i].dp_flag = 0;
1324 	partp[partition-1].dp_flag = ACTIVE;
1325 
1326 	status = 1;
1327 	break;
1328     }
1329     return (status);
1330 }
1331 
1332 
1333 static int
1334 process_line(char *line)
1335 {
1336     CMD		command;
1337     int		status = 1;
1338 
1339 	while (1) {
1340 	parse_config_line(line, &command);
1341 		switch (command.cmd) {
1342 	case 0:
1343 	    /*
1344 	     * Comment or blank line
1345 	     */
1346 	    break;
1347 	case 'g':
1348 	    /*
1349 	     * Set geometry
1350 	     */
1351 	    status = process_geometry(&command);
1352 	    break;
1353 	case 'p':
1354 	    status = process_partition(&command);
1355 	    break;
1356 	case 'a':
1357 	    status = process_active(&command);
1358 	    break;
1359 	default:
1360 	    status = 0;
1361 	    break;
1362 	}
1363 	break;
1364     }
1365     return (status);
1366 }
1367 
1368 
1369 static int
1370 read_config(char *config_file)
1371 {
1372     FILE	*fp = NULL;
1373     int		status = 1;
1374     char	buf[1010];
1375 
1376 	while (1) {
1377 		if (strcmp(config_file, "-") != 0) {
1378 	    /*
1379 	     * We're not reading from stdin
1380 	     */
1381 			if ((fp = fopen(config_file, "r")) == NULL) {
1382 		status = 0;
1383 		break;
1384 	    }
1385 		} else {
1386 	    fp = stdin;
1387 	}
1388 	current_line_number = 0;
1389 		while (!feof(fp)) {
1390 	    if (fgets(buf, sizeof(buf), fp) == NULL)
1391 		break;
1392 	    ++current_line_number;
1393 	    status = process_line(buf);
1394 	    if (status == 0)
1395 		break;
1396 	    }
1397 	break;
1398     }
1399 	if (fp) {
1400 	/*
1401 	 * It doesn't matter if we're reading from stdin, as we've reached EOF
1402 	 */
1403 	fclose(fp);
1404     }
1405     return (status);
1406 }
1407 
1408 
1409 static void
1410 reset_boot(void)
1411 {
1412     int				i;
1413     struct dos_partition	*partp;
1414 
1415     init_boot();
1416     for (i = 0; i < 4; ++i) {
1417 	partp = &mboot.parts[i];
1418 	bzero(partp, sizeof(*partp));
1419     }
1420 }
1421 
1422 static int
1423 sanitize_partition(struct dos_partition *partp)
1424 {
1425     u_int32_t			prev_head_boundary, prev_cyl_boundary;
1426     u_int32_t			max_end, size, start;
1427 
1428     start = partp->dp_start;
1429     size = partp->dp_size;
1430     max_end = start + size;
1431     /* Only allow a zero size if the partition is being marked unused. */
1432     if (size == 0) {
1433 	if (start == 0 && partp->dp_typ == 0)
1434 	    return (1);
1435 	warnx("ERROR: size of partition is zero");
1436 	return (0);
1437     }
1438     /* Return if no adjustment is necessary. */
1439     if (start % dos_sectors == 0 && (start + size) % dos_sectors == 0)
1440 	return (1);
1441 
1442     if (start == 0) {
1443 	    warnx("WARNING: partition overlaps with partition table");
1444 	    if (ok("Correct this automatically?"))
1445 		    start = dos_sectors;
1446     }
1447     if (start % dos_sectors != 0)
1448 	warnx("WARNING: partition does not start on a head boundary");
1449     if ((start  +size) % dos_sectors != 0)
1450 	warnx("WARNING: partition does not end on a cylinder boundary");
1451     warnx("WARNING: this may confuse the BIOS or some operating systems");
1452     if (!ok("Correct this automatically?"))
1453 	return (1);
1454 
1455     /*
1456      * Adjust start upwards, if necessary, to fall on a head boundary.
1457      */
1458     if (start % dos_sectors != 0) {
1459 	prev_head_boundary = start / dos_sectors * dos_sectors;
1460 	if (max_end < dos_sectors ||
1461 	    prev_head_boundary >= max_end - dos_sectors) {
1462 	    /*
1463 	     * Can't go past end of partition
1464 	     */
1465 	    warnx(
1466     "ERROR: unable to adjust start of partition to fall on a head boundary");
1467 	    return (0);
1468         }
1469 	start = prev_head_boundary + dos_sectors;
1470     }
1471 
1472     /*
1473      * Adjust size downwards, if necessary, to fall on a cylinder
1474      * boundary.
1475      */
1476     prev_cyl_boundary = ((start + size) / dos_cylsecs) * dos_cylsecs;
1477     if (prev_cyl_boundary > start)
1478 	size = prev_cyl_boundary - start;
1479     else {
1480 	warnx("ERROR: could not adjust partition to start on a head boundary\n\
1481     and end on a cylinder boundary.");
1482 	return (0);
1483     }
1484 
1485     /* Finally, commit any changes to partp and return. */
1486     if (start != partp->dp_start) {
1487 	warnx("WARNING: adjusting start offset of partition to %u",
1488 	    (u_int)start);
1489 	partp->dp_start = start;
1490     }
1491     if (size != partp->dp_size) {
1492 	warnx("WARNING: adjusting size of partition to %u", (u_int)size);
1493 	partp->dp_size = size;
1494     }
1495 
1496     return (1);
1497 }
1498 
1499 /*
1500  * Try figuring out the root device's canonical disk name.
1501  * The following choices are considered:
1502  *   /dev/ad0s1a     => /dev/ad0
1503  *   /dev/da0a       => /dev/da0
1504  *   /dev/vinum/root => /dev/vinum/root
1505  * A ".eli" part is removed if it exists (see geli(8)).
1506  * A ".journal" ending is removed if it exists (see gjournal(8)).
1507  */
1508 static char *
1509 get_rootdisk(void)
1510 {
1511 	struct statfs rootfs;
1512 	regex_t re;
1513 #define NMATCHES 2
1514 	regmatch_t rm[NMATCHES];
1515 	char dev[PATH_MAX], *s;
1516 	int rv;
1517 
1518 	if (statfs("/", &rootfs) == -1)
1519 		err(1, "statfs(\"/\")");
1520 
1521 	if ((rv = regcomp(&re, "^(/dev/[a-z/]+[0-9]*)([sp][0-9]+)?[a-h]?(\\.journal)?$",
1522 		    REG_EXTENDED)) != 0)
1523 		errx(1, "regcomp() failed (%d)", rv);
1524 	strlcpy(dev, rootfs.f_mntfromname, sizeof (dev));
1525 	if ((s = strstr(dev, ".eli")) != NULL)
1526 	    memmove(s, s+4, strlen(s + 4) + 1);
1527 
1528 	if ((rv = regexec(&re, dev, NMATCHES, rm, 0)) != 0)
1529 		errx(1,
1530 "mounted root fs resource doesn't match expectations (regexec returned %d)",
1531 		    rv);
1532 	if ((s = malloc(rm[1].rm_eo - rm[1].rm_so + 1)) == NULL)
1533 		errx(1, "out of memory");
1534 	memcpy(s, rootfs.f_mntfromname + rm[1].rm_so,
1535 	    rm[1].rm_eo - rm[1].rm_so);
1536 	s[rm[1].rm_eo - rm[1].rm_so] = 0;
1537 
1538 	return s;
1539 }
1540