xref: /dflybsd-src/sbin/newfs_msdos/mkfs_msdos.c (revision 8bdbc095884336714d87f2877b79c17d22de5cd3)
1 /*
2  * Copyright (c) 1998 Robert Nordier
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  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in
12  *    the documentation and/or other materials provided with the
13  *    distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS
16  * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY
19  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
21  * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
22  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
23  * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
24  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
25  * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  *
27  * $FreeBSD: head/sbin/newfs_msdos/mkfs_msdos.c 305075 2016-08-30 18:01:26Z imp $
28  */
29 
30 #include <sys/param.h>
31 #include <sys/disklabel32.h>
32 #include <sys/diskmbr.h>
33 #include <sys/diskslice.h>
34 #include <sys/mount.h>
35 #include <sys/stat.h>
36 #include <sys/time.h>
37 
38 #include <machine/ioctl_fd.h>
39 
40 #include <ctype.h>
41 #include <disktab.h>
42 #include <err.h>
43 #include <errno.h>
44 #include <fcntl.h>
45 #include <inttypes.h>
46 #include <paths.h>
47 #include <signal.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <time.h>
52 #include <unistd.h>
53 
54 #include "mkfs_msdos.h"
55 
56 #define	MAXU16	  0xffff	/* maximum unsigned 16-bit quantity */
57 #define	BPN	  4		/* bits per nibble */
58 #define	NPB	  2		/* nibbles per byte */
59 
60 #define	MINBPS	  512		/* minimum bytes per sector */
61 #define	MAXSPC	  128		/* maximum sectors per cluster */
62 #define	MAXNFT	  16		/* maximum number of FATs */
63 #define	DEFBLK	  4096		/* default block size */
64 #define	DEFBLK16  2048		/* default block size FAT16 */
65 #define	DEFRDE	  512		/* default root directory entries */
66 #define	RESFTE	  2		/* reserved FAT entries */
67 #define	MINCLS12  1U		/* minimum FAT12 clusters */
68 #define	MINCLS16  0xff5U	/* minimum FAT16 clusters */
69 #define	MINCLS32  0xfff5U	/* minimum FAT32 clusters */
70 #define	MAXCLS12  0xff4U	/* maximum FAT12 clusters */
71 #define	MAXCLS16  0xfff4U	/* maximum FAT16 clusters */
72 #define	MAXCLS32  0xffffff4U	/* maximum FAT32 clusters */
73 
74 #define	mincls(fat)  ((fat) == 12 ? MINCLS12 :	\
75 		      (fat) == 16 ? MINCLS16 :	\
76 				    MINCLS32)
77 
78 #define	maxcls(fat)  ((fat) == 12 ? MAXCLS12 :	\
79 		      (fat) == 16 ? MAXCLS16 :	\
80 				    MAXCLS32)
81 
82 #define	mk1(p, x)				\
83     (p) = (u_int8_t)(x)
84 
85 #define	mk2(p, x)				\
86     (p)[0] = (u_int8_t)(x),			\
87     (p)[1] = (u_int8_t)((x) >> 010)
88 
89 #define	mk4(p, x)				\
90     (p)[0] = (u_int8_t)(x),			\
91     (p)[1] = (u_int8_t)((x) >> 010),		\
92     (p)[2] = (u_int8_t)((x) >> 020),		\
93     (p)[3] = (u_int8_t)((x) >> 030)
94 
95 struct bs {
96     u_int8_t bsJump[3];			/* bootstrap entry point */
97     u_int8_t bsOemName[8];		/* OEM name and version */
98 } __packed;
99 
100 struct bsbpb {
101     u_int8_t bpbBytesPerSec[2];		/* bytes per sector */
102     u_int8_t bpbSecPerClust;		/* sectors per cluster */
103     u_int8_t bpbResSectors[2];		/* reserved sectors */
104     u_int8_t bpbFATs;			/* number of FATs */
105     u_int8_t bpbRootDirEnts[2];		/* root directory entries */
106     u_int8_t bpbSectors[2];		/* total sectors */
107     u_int8_t bpbMedia;			/* media descriptor */
108     u_int8_t bpbFATsecs[2];		/* sectors per FAT */
109     u_int8_t bpbSecPerTrack[2];		/* sectors per track */
110     u_int8_t bpbHeads[2];		/* drive heads */
111     u_int8_t bpbHiddenSecs[4];		/* hidden sectors */
112     u_int8_t bpbHugeSectors[4];		/* big total sectors */
113 } __packed;
114 
115 struct bsxbpb {
116     u_int8_t bpbBigFATsecs[4];		/* big sectors per FAT */
117     u_int8_t bpbExtFlags[2];		/* FAT control flags */
118     u_int8_t bpbFSVers[2];		/* file system version */
119     u_int8_t bpbRootClust[4];		/* root directory start cluster */
120     u_int8_t bpbFSInfo[2];		/* file system info sector */
121     u_int8_t bpbBackup[2];		/* backup boot sector */
122     u_int8_t bpbReserved[12];		/* reserved */
123 } __packed;
124 
125 struct bsx {
126     u_int8_t exDriveNumber;		/* drive number */
127     u_int8_t exReserved1;		/* reserved */
128     u_int8_t exBootSignature;		/* extended boot signature */
129     u_int8_t exVolumeID[4];		/* volume ID number */
130     u_int8_t exVolumeLabel[11];		/* volume label */
131     u_int8_t exFileSysType[8];		/* file system type */
132 } __packed;
133 
134 struct de {
135     u_int8_t deName[11];		/* name and extension */
136     u_int8_t deAttributes;		/* attributes */
137     u_int8_t rsvd[10];			/* reserved */
138     u_int8_t deMTime[2];		/* last-modified time */
139     u_int8_t deMDate[2];		/* last-modified date */
140     u_int8_t deStartCluster[2];		/* starting cluster */
141     u_int8_t deFileSize[4];		/* size */
142 } __packed;
143 
144 struct bpb {
145     u_int bpbBytesPerSec;		/* bytes per sector */
146     u_int bpbSecPerClust;		/* sectors per cluster */
147     u_int bpbResSectors;		/* reserved sectors */
148     u_int bpbFATs;			/* number of FATs */
149     u_int bpbRootDirEnts;		/* root directory entries */
150     u_int bpbSectors;			/* total sectors */
151     u_int bpbMedia;			/* media descriptor */
152     u_int bpbFATsecs;			/* sectors per FAT */
153     u_int bpbSecPerTrack;		/* sectors per track */
154     u_int bpbHeads;			/* drive heads */
155     u_int bpbHiddenSecs;		/* hidden sectors */
156     u_int bpbHugeSectors;		/* big total sectors */
157     u_int bpbBigFATsecs;		/* big sectors per FAT */
158     u_int bpbRootClust;			/* root directory start cluster */
159     u_int bpbFSInfo;			/* file system info sector */
160     u_int bpbBackup;			/* backup boot sector */
161 };
162 
163 #define	BPBGAP 0, 0, 0, 0, 0, 0
164 
165 static struct {
166     const char *name;
167     struct bpb bpb;
168 } const stdfmt[] = {
169     {"160",  {512, 1, 1, 2,  64,  320, 0xfe, 1,  8, 1, BPBGAP}},
170     {"180",  {512, 1, 1, 2,  64,  360, 0xfc, 2,  9, 1, BPBGAP}},
171     {"320",  {512, 2, 1, 2, 112,  640, 0xff, 1,  8, 2, BPBGAP}},
172     {"360",  {512, 2, 1, 2, 112,  720, 0xfd, 2,  9, 2, BPBGAP}},
173     {"640",  {512, 2, 1, 2, 112, 1280, 0xfb, 2,  8, 2, BPBGAP}},
174     {"720",  {512, 2, 1, 2, 112, 1440, 0xf9, 3,  9, 2, BPBGAP}},
175     {"1200", {512, 1, 1, 2, 224, 2400, 0xf9, 7, 15, 2, BPBGAP}},
176     {"1232", {1024,1, 1, 2, 192, 1232, 0xfe, 2,  8, 2, BPBGAP}},
177     {"1440", {512, 1, 1, 2, 224, 2880, 0xf0, 9, 18, 2, BPBGAP}},
178     {"2880", {512, 2, 1, 2, 240, 5760, 0xf0, 9, 36, 2, BPBGAP}}
179 };
180 
181 static const u_int8_t bootcode[] = {
182     0xfa,			/* cli		    */
183     0x31, 0xc0,			/* xor	   ax,ax    */
184     0x8e, 0xd0,			/* mov	   ss,ax    */
185     0xbc, 0x00, 0x7c,		/* mov	   sp,7c00h */
186     0xfb,			/* sti		    */
187     0x8e, 0xd8,			/* mov	   ds,ax    */
188     0xe8, 0x00, 0x00,		/* call    $ + 3    */
189     0x5e,			/* pop	   si	    */
190     0x83, 0xc6, 0x19,		/* add	   si,+19h  */
191     0xbb, 0x07, 0x00,		/* mov	   bx,0007h */
192     0xfc,			/* cld		    */
193     0xac,			/* lodsb	    */
194     0x84, 0xc0,			/* test    al,al    */
195     0x74, 0x06,			/* jz	   $ + 8    */
196     0xb4, 0x0e,			/* mov	   ah,0eh   */
197     0xcd, 0x10,			/* int	   10h	    */
198     0xeb, 0xf5,			/* jmp	   $ - 9    */
199     0x30, 0xe4,			/* xor	   ah,ah    */
200     0xcd, 0x16,			/* int	   16h	    */
201     0xcd, 0x19,			/* int	   19h	    */
202     0x0d, 0x0a,
203     'N', 'o', 'n', '-', 's', 'y', 's', 't',
204     'e', 'm', ' ', 'd', 'i', 's', 'k',
205     0x0d, 0x0a,
206     'P', 'r', 'e', 's', 's', ' ', 'a', 'n',
207     'y', ' ', 'k', 'e', 'y', ' ', 't', 'o',
208     ' ', 'r', 'e', 'b', 'o', 'o', 't',
209     0x0d, 0x0a,
210     0
211 };
212 
213 static volatile sig_atomic_t got_siginfo;
214 static void infohandler(int);
215 
216 static int check_mounted(const char *, mode_t);
217 static int getstdfmt(const char *, struct bpb *);
218 static int getdiskinfo(int, const char *, const char *, int, struct bpb *);
219 static void print_bpb(struct bpb *);
220 static int ckgeom(const char *, u_int, const char *);
221 static void mklabel(u_int8_t *, const char *);
222 static int oklabel(const char *);
223 static void setstr(u_int8_t *, const char *, size_t);
224 
225 int
226 mkfs_msdos(const char *fname, const char *dtype, const struct msdos_options *op)
227 {
228     char buf[MAXPATHLEN];
229     struct sigaction si_sa;
230     struct stat sb;
231     struct timeval tv;
232     struct bpb bpb;
233     struct tm *tm;
234     struct bs *bs;
235     struct bsbpb *bsbpb;
236     struct bsxbpb *bsxbpb;
237     struct bsx *bsx;
238     struct de *de;
239     u_int8_t *img;
240     const char *bname;
241     ssize_t n;
242     time_t now;
243     u_int fat, bss, rds, cls, dir, lsn, x, x1, x2;
244     int fd, fd1, rv;
245     struct msdos_options o = *op;
246 
247     img = NULL;
248     rv = -1;
249 
250     if (o.block_size && o.sectors_per_cluster) {
251 	warnx("Cannot specify both block size and sectors per cluster");
252 	goto done;
253     }
254     if (o.OEM_string && strlen(o.OEM_string) > 8) {
255 	warnx("%s: bad OEM string", o.OEM_string);
256 	goto done;
257     }
258     if (o.create_size) {
259 	if (o.no_create) {
260 	    warnx("create (-C) is incompatible with -N");
261 	    goto done;
262 	}
263 	fd = open(fname, O_RDWR | O_CREAT | O_TRUNC, 0644);
264 	if (fd == -1) {
265 	    warnx("failed to create %s", fname);
266 	    goto done;
267 	}
268 	if (ftruncate(fd, o.create_size)) {
269 	    warnx("failed to initialize %jd bytes", (intmax_t)o.create_size);
270 	    goto done;
271 	}
272     } else if ((fd = open(fname, o.no_create ? O_RDONLY : O_RDWR)) == -1) {
273 	warn("%s", fname);
274 	goto done;
275     }
276     if (fstat(fd, &sb)) {
277 	warn("%s", fname);
278 	goto done;
279     }
280     if (o.create_size) {
281 	if (!S_ISREG(sb.st_mode))
282 	    warnx("warning, %s is not a regular file", fname);
283     } else {
284 	if (!S_ISCHR(sb.st_mode))
285 	    warnx("warning, %s is not a character device", fname);
286     }
287     if (!o.no_create)
288 	if (check_mounted(fname, sb.st_mode) == -1)
289 	    goto done;
290     if (o.offset && o.offset != lseek(fd, o.offset, SEEK_SET)) {
291 	warnx("cannot seek to %jd", (intmax_t)o.offset);
292 	goto done;
293     }
294     memset(&bpb, 0, sizeof(bpb));
295     if (o.floppy) {
296 	if (getstdfmt(o.floppy, &bpb) == -1)
297 	    goto done;
298 	bpb.bpbHugeSectors = bpb.bpbSectors;
299 	bpb.bpbSectors = 0;
300 	bpb.bpbBigFATsecs = bpb.bpbFATsecs;
301 	bpb.bpbFATsecs = 0;
302     }
303     if (o.drive_heads)
304 	bpb.bpbHeads = o.drive_heads;
305     if (o.sectors_per_track)
306 	bpb.bpbSecPerTrack = o.sectors_per_track;
307     if (o.bytes_per_sector)
308 	bpb.bpbBytesPerSec = o.bytes_per_sector;
309     if (o.size)
310 	bpb.bpbHugeSectors = o.size;
311     if (o.hidden_sectors_set)
312 	bpb.bpbHiddenSecs = o.hidden_sectors;
313     if (!(o.floppy || (o.drive_heads && o.sectors_per_track &&
314 	o.bytes_per_sector && o.size && o.hidden_sectors_set))) {
315 	getdiskinfo(fd, fname, dtype, o.hidden_sectors_set, &bpb);
316 	bpb.bpbHugeSectors -= (o.offset / bpb.bpbBytesPerSec);
317 	if (bpb.bpbSecPerClust == 0) {	/* set defaults */
318 	    if (bpb.bpbHugeSectors <= 6000)	/* about 3MB -> 512 bytes */
319 		bpb.bpbSecPerClust = 1;
320 	    else if (bpb.bpbHugeSectors <= (1<<17)) /* 64M -> 4k */
321 		bpb.bpbSecPerClust = 8;
322 	    else if (bpb.bpbHugeSectors <= (1<<19)) /* 256M -> 8k */
323 		bpb.bpbSecPerClust = 16;
324 	    else if (bpb.bpbHugeSectors <= (1<<21)) /* 1G -> 16k */
325 		bpb.bpbSecPerClust = 32;
326 	    else
327 		bpb.bpbSecPerClust = 64;		/* otherwise 32k */
328 	}
329     }
330     if (!powerof2(bpb.bpbBytesPerSec)) {
331 	warnx("bytes/sector (%u) is not a power of 2", bpb.bpbBytesPerSec);
332 	goto done;
333     }
334     if (bpb.bpbBytesPerSec < MINBPS) {
335 	warnx("bytes/sector (%u) is too small; minimum is %u",
336 	     bpb.bpbBytesPerSec, MINBPS);
337 	goto done;
338     }
339 
340     if (o.volume_label && !oklabel(o.volume_label)) {
341 	warnx("%s: bad volume label", o.volume_label);
342 	goto done;
343     }
344     if (!(fat = o.fat_type)) {
345 	if (o.floppy)
346 	    fat = 12;
347 	else if (!o.directory_entries && (o.info_sector || o.backup_sector))
348 	    fat = 32;
349     }
350     if ((fat == 32 && o.directory_entries) ||
351         (fat != 32 && (o.info_sector || o.backup_sector))) {
352 	warnx("-%c is not a legal FAT%s option",
353 	     fat == 32 ? 'e' : o.info_sector ? 'i' : 'k',
354 	     fat == 32 ? "32" : "12/16");
355 	goto done;
356     }
357     if (o.floppy && fat == 32)
358 	bpb.bpbRootDirEnts = 0;
359     if (fat != 0 && fat != 12 && fat != 16 && fat != 32) {
360 	warnx("%d: bad FAT type", fat);
361 	goto done;
362     }
363 
364     if (o.block_size) {
365 	if (!powerof2(o.block_size)) {
366 	    warnx("block size (%u) is not a power of 2", o.block_size);
367 	    goto done;
368 	}
369 	if (o.block_size < bpb.bpbBytesPerSec) {
370 	    warnx("block size (%u) is too small; minimum is %u",
371 		 o.block_size, bpb.bpbBytesPerSec);
372 	    goto done;
373 	}
374 	if (o.block_size > bpb.bpbBytesPerSec * MAXSPC) {
375 	    warnx("block size (%u) is too large; maximum is %u",
376 		 o.block_size, bpb.bpbBytesPerSec * MAXSPC);
377 	    goto done;
378 	}
379 	bpb.bpbSecPerClust = o.block_size / bpb.bpbBytesPerSec;
380     }
381     if (o.sectors_per_cluster) {
382 	if (!powerof2(o.sectors_per_cluster)) {
383 	    warnx("sectors/cluster (%u) is not a power of 2",
384 		o.sectors_per_cluster);
385 	    goto done;
386 	}
387 	bpb.bpbSecPerClust = o.sectors_per_cluster;
388     }
389     if (o.reserved_sectors)
390 	bpb.bpbResSectors = o.reserved_sectors;
391     if (o.num_FAT) {
392 	if (o.num_FAT > MAXNFT) {
393 	    warnx("number of FATs (%u) is too large; maximum is %u",
394 		 o.num_FAT, MAXNFT);
395 	    goto done;
396 	}
397 	bpb.bpbFATs = o.num_FAT;
398     }
399     if (o.directory_entries)
400 	bpb.bpbRootDirEnts = o.directory_entries;
401     if (o.media_descriptor_set) {
402 	if (o.media_descriptor < 0xf0) {
403 	    warnx("illegal media descriptor (%#x)", o.media_descriptor);
404 	    goto done;
405 	}
406 	bpb.bpbMedia = o.media_descriptor;
407     }
408     if (o.sectors_per_fat)
409 	bpb.bpbBigFATsecs = o.sectors_per_fat;
410     if (o.info_sector)
411 	bpb.bpbFSInfo = o.info_sector;
412     if (o.backup_sector)
413 	bpb.bpbBackup = o.backup_sector;
414     bss = 1;
415     bname = NULL;
416     fd1 = -1;
417     if (o.bootstrap) {
418 	bname = o.bootstrap;
419 	if (!strchr(bname, '/')) {
420 	    snprintf(buf, sizeof(buf), "/boot/%s", bname);
421 	    if (!(bname = strdup(buf))) {
422 		warn(NULL);
423 		goto done;
424 	    }
425 	}
426 	if ((fd1 = open(bname, O_RDONLY)) == -1 || fstat(fd1, &sb)) {
427 	    warn("%s", bname);
428 	    goto done;
429 	}
430 	if (!S_ISREG(sb.st_mode) || sb.st_size % bpb.bpbBytesPerSec ||
431 	    sb.st_size < bpb.bpbBytesPerSec ||
432 	    sb.st_size > bpb.bpbBytesPerSec * MAXU16) {
433 	    warnx("%s: inappropriate file type or format", bname);
434 	    goto done;
435 	}
436 	bss = sb.st_size / bpb.bpbBytesPerSec;
437     }
438     if (!bpb.bpbFATs)
439 	bpb.bpbFATs = 2;
440     if (!fat) {
441 	if (bpb.bpbHugeSectors < (bpb.bpbResSectors ? bpb.bpbResSectors : bss) +
442 	    howmany((RESFTE + (bpb.bpbSecPerClust ? MINCLS16 : MAXCLS12 + 1)) *
443 		(bpb.bpbSecPerClust ? 16 : 12) / BPN,
444 		bpb.bpbBytesPerSec * NPB) *
445 	    bpb.bpbFATs +
446 	    howmany(bpb.bpbRootDirEnts ? bpb.bpbRootDirEnts : DEFRDE,
447 		    bpb.bpbBytesPerSec / sizeof(struct de)) +
448 	    (bpb.bpbSecPerClust ? MINCLS16 : MAXCLS12 + 1) *
449 	    (bpb.bpbSecPerClust ? bpb.bpbSecPerClust :
450 	     howmany(DEFBLK, bpb.bpbBytesPerSec)))
451 	    fat = 12;
452 	else if (bpb.bpbRootDirEnts || bpb.bpbHugeSectors <
453 		 (bpb.bpbResSectors ? bpb.bpbResSectors : bss) +
454 		 howmany((RESFTE + MAXCLS16) * 2, bpb.bpbBytesPerSec) *
455 		 bpb.bpbFATs +
456 		 howmany(DEFRDE, bpb.bpbBytesPerSec / sizeof(struct de)) +
457 		 (MAXCLS16 + 1) *
458 		 (bpb.bpbSecPerClust ? bpb.bpbSecPerClust :
459 		  howmany(8192, bpb.bpbBytesPerSec)))
460 	    fat = 16;
461 	else
462 	    fat = 32;
463     }
464     x = bss;
465     if (fat == 32) {
466 	if (!bpb.bpbFSInfo) {
467 	    if (x == MAXU16 || x == bpb.bpbBackup) {
468 		warnx("no room for info sector");
469 		goto done;
470 	    }
471 	    bpb.bpbFSInfo = x;
472 	}
473 	if (bpb.bpbFSInfo != MAXU16 && x <= bpb.bpbFSInfo)
474 	    x = bpb.bpbFSInfo + 1;
475 	if (!bpb.bpbBackup) {
476 	    if (x == MAXU16) {
477 		warnx("no room for backup sector");
478 		goto done;
479 	    }
480 	    bpb.bpbBackup = x;
481 	} else if (bpb.bpbBackup != MAXU16 && bpb.bpbBackup == bpb.bpbFSInfo) {
482 	    warnx("backup sector would overwrite info sector");
483 	    goto done;
484 	}
485 	if (bpb.bpbBackup != MAXU16 && x <= bpb.bpbBackup)
486 	    x = bpb.bpbBackup + 1;
487     }
488     if (!bpb.bpbResSectors)
489 	bpb.bpbResSectors = fat == 32 ?
490 	    MAX(x, MAX(16384 / bpb.bpbBytesPerSec, 4)) : x;
491     else if (bpb.bpbResSectors < x) {
492 	warnx("too few reserved sectors (need %d have %d)", x,
493 	     bpb.bpbResSectors);
494 	goto done;
495     }
496     if (fat != 32 && !bpb.bpbRootDirEnts)
497 	bpb.bpbRootDirEnts = DEFRDE;
498     rds = howmany(bpb.bpbRootDirEnts, bpb.bpbBytesPerSec / sizeof(struct de));
499     if (!bpb.bpbSecPerClust)
500 	for (bpb.bpbSecPerClust = howmany(fat == 16 ? DEFBLK16 :
501 					  DEFBLK, bpb.bpbBytesPerSec);
502 	     bpb.bpbSecPerClust < MAXSPC &&
503 	     bpb.bpbResSectors +
504 	     howmany((RESFTE + maxcls(fat)) * (fat / BPN),
505 		     bpb.bpbBytesPerSec * NPB) *
506 	     bpb.bpbFATs +
507 	     rds +
508 	     (u_int64_t) (maxcls(fat) + 1) *
509 	     bpb.bpbSecPerClust <= bpb.bpbHugeSectors;
510 	     bpb.bpbSecPerClust <<= 1)
511 	    continue;
512     if (fat != 32 && bpb.bpbBigFATsecs > MAXU16) {
513 	warnx("too many sectors/FAT for FAT12/16");
514 	goto done;
515     }
516     x1 = bpb.bpbResSectors + rds;
517     x = bpb.bpbBigFATsecs ? bpb.bpbBigFATsecs : 1;
518     if (x1 + (u_int64_t)x * bpb.bpbFATs > bpb.bpbHugeSectors) {
519 	warnx("meta data exceeds file system size");
520 	goto done;
521     }
522     x1 += x * bpb.bpbFATs;
523     x = (u_int64_t)(bpb.bpbHugeSectors - x1) * bpb.bpbBytesPerSec * NPB /
524 	(bpb.bpbSecPerClust * bpb.bpbBytesPerSec * NPB + fat /
525 	 BPN * bpb.bpbFATs);
526     x2 = howmany((RESFTE + MIN(x, maxcls(fat))) * (fat / BPN),
527 		 bpb.bpbBytesPerSec * NPB);
528     if (!bpb.bpbBigFATsecs) {
529 	bpb.bpbBigFATsecs = x2;
530 	x1 += (bpb.bpbBigFATsecs - 1) * bpb.bpbFATs;
531     }
532     cls = (bpb.bpbHugeSectors - x1) / bpb.bpbSecPerClust;
533     x = (u_int64_t)bpb.bpbBigFATsecs * bpb.bpbBytesPerSec * NPB / (fat / BPN) -
534 	RESFTE;
535     if (cls > x)
536 	cls = x;
537     if (bpb.bpbBigFATsecs < x2)
538 	warnx("warning: sectors/FAT limits file system to %u clusters",
539 	      cls);
540     if (cls < mincls(fat)) {
541 	warnx("%u clusters too few clusters for FAT%u, need %u", cls, fat,
542 	    mincls(fat));
543 	goto done;
544     }
545     if (cls > maxcls(fat)) {
546 	cls = maxcls(fat);
547 	bpb.bpbHugeSectors = x1 + (cls + 1) * bpb.bpbSecPerClust - 1;
548 	warnx("warning: FAT type limits file system to %u sectors",
549 	      bpb.bpbHugeSectors);
550     }
551     printf("%s: %u sector%s in %u FAT%u cluster%s "
552 	   "(%u bytes/cluster)\n", fname, cls * bpb.bpbSecPerClust,
553 	   cls * bpb.bpbSecPerClust == 1 ? "" : "s", cls, fat,
554 	   cls == 1 ? "" : "s", bpb.bpbBytesPerSec * bpb.bpbSecPerClust);
555     if (!bpb.bpbMedia)
556 	bpb.bpbMedia = !bpb.bpbHiddenSecs ? 0xf0 : 0xf8;
557     if (fat == 32)
558 	bpb.bpbRootClust = RESFTE;
559     if (bpb.bpbHugeSectors <= MAXU16) {
560 	bpb.bpbSectors = bpb.bpbHugeSectors;
561 	bpb.bpbHugeSectors = 0;
562     }
563     if (fat != 32) {
564 	bpb.bpbFATsecs = bpb.bpbBigFATsecs;
565 	bpb.bpbBigFATsecs = 0;
566     }
567     print_bpb(&bpb);
568     if (!o.no_create) {
569 	gettimeofday(&tv, NULL);
570 	now = tv.tv_sec;
571 	tm = localtime(&now);
572 	if (!(img = malloc(bpb.bpbBytesPerSec))) {
573 	    warn(NULL);
574 	    goto done;
575 	}
576 	dir = bpb.bpbResSectors + (bpb.bpbFATsecs ? bpb.bpbFATsecs :
577 				   bpb.bpbBigFATsecs) * bpb.bpbFATs;
578 	memset(&si_sa, 0, sizeof(si_sa));
579 	si_sa.sa_handler = infohandler;
580 	if (sigaction(SIGINFO, &si_sa, NULL) == -1) {
581 	    warn("sigaction SIGINFO");
582 	    goto done;
583 	}
584 	for (lsn = 0; lsn < dir + (fat == 32 ? bpb.bpbSecPerClust : rds); lsn++) {
585 	    if (got_siginfo) {
586 		    fprintf(stderr,"%s: writing sector %u of %u (%u%%)\n",
587 			fname, lsn,
588 			(dir + (fat == 32 ? bpb.bpbSecPerClust: rds)),
589 			(lsn * 100) / (dir +
590 			    (fat == 32 ? bpb.bpbSecPerClust: rds)));
591 		    got_siginfo = 0;
592 	    }
593 	    x = lsn;
594 	    if (o.bootstrap &&
595 		fat == 32 && bpb.bpbBackup != MAXU16 &&
596 		bss <= bpb.bpbBackup && x >= bpb.bpbBackup) {
597 		x -= bpb.bpbBackup;
598 		if (!x && lseek(fd1, o.offset, SEEK_SET)) {
599 		    warn("%s", bname);
600 		    goto done;
601 		}
602 	    }
603 	    if (o.bootstrap && x < bss) {
604 		if ((n = read(fd1, img, bpb.bpbBytesPerSec)) == -1) {
605 		    warn("%s", bname);
606 		    goto done;
607 		}
608 		if ((unsigned)n != bpb.bpbBytesPerSec) {
609 		    warnx("%s: can't read sector %u", bname, x);
610 		    goto done;
611 		}
612 	    } else
613 		memset(img, 0, bpb.bpbBytesPerSec);
614 	    if (!lsn ||
615 		(fat == 32 && bpb.bpbBackup != MAXU16 &&
616 		 lsn == bpb.bpbBackup)) {
617 		x1 = sizeof(struct bs);
618 		bsbpb = (struct bsbpb *)(img + x1);
619 		mk2(bsbpb->bpbBytesPerSec, bpb.bpbBytesPerSec);
620 		mk1(bsbpb->bpbSecPerClust, bpb.bpbSecPerClust);
621 		mk2(bsbpb->bpbResSectors, bpb.bpbResSectors);
622 		mk1(bsbpb->bpbFATs, bpb.bpbFATs);
623 		mk2(bsbpb->bpbRootDirEnts, bpb.bpbRootDirEnts);
624 		mk2(bsbpb->bpbSectors, bpb.bpbSectors);
625 		mk1(bsbpb->bpbMedia, bpb.bpbMedia);
626 		mk2(bsbpb->bpbFATsecs, bpb.bpbFATsecs);
627 		mk2(bsbpb->bpbSecPerTrack, bpb.bpbSecPerTrack);
628 		mk2(bsbpb->bpbHeads, bpb.bpbHeads);
629 		mk4(bsbpb->bpbHiddenSecs, bpb.bpbHiddenSecs);
630 		mk4(bsbpb->bpbHugeSectors, bpb.bpbHugeSectors);
631 		x1 += sizeof(struct bsbpb);
632 		if (fat == 32) {
633 		    bsxbpb = (struct bsxbpb *)(img + x1);
634 		    mk4(bsxbpb->bpbBigFATsecs, bpb.bpbBigFATsecs);
635 		    mk2(bsxbpb->bpbExtFlags, 0);
636 		    mk2(bsxbpb->bpbFSVers, 0);
637 		    mk4(bsxbpb->bpbRootClust, bpb.bpbRootClust);
638 		    mk2(bsxbpb->bpbFSInfo, bpb.bpbFSInfo);
639 		    mk2(bsxbpb->bpbBackup, bpb.bpbBackup);
640 		    x1 += sizeof(struct bsxbpb);
641 		}
642 		bsx = (struct bsx *)(img + x1);
643 		mk1(bsx->exBootSignature, 0x29);
644 		if (o.volume_id_set)
645 		    x = o.volume_id;
646 		else
647 		    x = (((u_int)(1 + tm->tm_mon) << 8 |
648 			  (u_int)tm->tm_mday) +
649 			 ((u_int)tm->tm_sec << 8 |
650 			  (u_int)(tv.tv_usec / 10))) << 16 |
651 			((u_int)(1900 + tm->tm_year) +
652 			 ((u_int)tm->tm_hour << 8 |
653 			  (u_int)tm->tm_min));
654 		mk4(bsx->exVolumeID, x);
655 		mklabel(bsx->exVolumeLabel, o.volume_label ? o.volume_label : "NO NAME");
656 		snprintf(buf, sizeof(buf), "FAT%u", fat);
657 		setstr(bsx->exFileSysType, buf, sizeof(bsx->exFileSysType));
658 		if (!o.bootstrap) {
659 		    x1 += sizeof(struct bsx);
660 		    bs = (struct bs *)img;
661 		    mk1(bs->bsJump[0], 0xeb);
662 		    mk1(bs->bsJump[1], x1 - 2);
663 		    mk1(bs->bsJump[2], 0x90);
664 		    setstr(bs->bsOemName, o.OEM_string ? o.OEM_string : "BSD4.4  ",
665 			   sizeof(bs->bsOemName));
666 		    memcpy(img + x1, bootcode, sizeof(bootcode));
667 		    mk2(img + MINBPS - 2, DOSMAGIC);
668 		}
669 	    } else if (fat == 32 && bpb.bpbFSInfo != MAXU16 &&
670 		       (lsn == bpb.bpbFSInfo ||
671 			(bpb.bpbBackup != MAXU16 &&
672 			 lsn == bpb.bpbBackup + bpb.bpbFSInfo))) {
673 		mk4(img, 0x41615252);
674 		mk4(img + MINBPS - 28, 0x61417272);
675 		mk4(img + MINBPS - 24, 0xffffffff);
676 		mk4(img + MINBPS - 20, bpb.bpbRootClust);
677 		mk2(img + MINBPS - 2, DOSMAGIC);
678 	    } else if (lsn >= bpb.bpbResSectors && lsn < dir &&
679 		       !((lsn - bpb.bpbResSectors) %
680 			 (bpb.bpbFATsecs ? bpb.bpbFATsecs :
681 			  bpb.bpbBigFATsecs))) {
682 		mk1(img[0], bpb.bpbMedia);
683 		for (x = 1; x < fat * (fat == 32 ? 3 : 2) / 8; x++)
684 		    mk1(img[x], fat == 32 && x % 4 == 3 ? 0x0f : 0xff);
685 	    } else if (lsn == dir && o.volume_label) {
686 		de = (struct de *)img;
687 		mklabel(de->deName, o.volume_label);
688 		mk1(de->deAttributes, 050);
689 		x = (u_int)tm->tm_hour << 11 |
690 		    (u_int)tm->tm_min << 5 |
691 		    (u_int)tm->tm_sec >> 1;
692 		mk2(de->deMTime, x);
693 		x = (u_int)(tm->tm_year - 80) << 9 |
694 		    (u_int)(tm->tm_mon + 1) << 5 |
695 		    (u_int)tm->tm_mday;
696 		mk2(de->deMDate, x);
697 	    }
698 	    if ((n = write(fd, img, bpb.bpbBytesPerSec)) == -1) {
699 		warn("%s", fname);
700 		goto done;
701 	    }
702 	    if ((unsigned)n != bpb.bpbBytesPerSec) {
703 		warnx("%s: can't write sector %u", fname, lsn);
704 		goto done;
705 	    }
706 	}
707     }
708     rv = 0;
709 done:
710     free(img);
711 
712     return rv;
713 }
714 
715 /*
716  * return -1 with error if file system is mounted.
717  */
718 static int
719 check_mounted(const char *fname, mode_t mode)
720 {
721     struct statfs *mp;
722     const char *s1, *s2;
723     size_t len;
724     int n, r;
725 
726     if (!(n = getmntinfo(&mp, MNT_NOWAIT))) {
727 	warn("getmntinfo");
728 	return -1;
729     }
730     len = strlen(_PATH_DEV);
731     s1 = fname;
732     if (!strncmp(s1, _PATH_DEV, len))
733 	s1 += len;
734     r = S_ISCHR(mode) && s1 != fname && *s1 == 'r';
735     for (; n--; mp++) {
736 	s2 = mp->f_mntfromname;
737 	if (!strncmp(s2, _PATH_DEV, len))
738 	    s2 += len;
739 	if ((r && s2 != mp->f_mntfromname && !strcmp(s1 + 1, s2)) ||
740 	    !strcmp(s1, s2)) {
741 	    warnx("%s is mounted on %s", fname, mp->f_mntonname);
742 	    return -1;
743 	}
744     }
745     return 0;
746 }
747 
748 /*
749  * Get a standard format.
750  */
751 static int
752 getstdfmt(const char *fmt, struct bpb *bpb)
753 {
754     u_int x, i;
755 
756     x = NELEM(stdfmt);
757     for (i = 0; i < x && strcmp(fmt, stdfmt[i].name); i++);
758     if (i == x) {
759 	warnx("%s: unknown standard format", fmt);
760 	return -1;
761     }
762     *bpb = stdfmt[i].bpb;
763     return 0;
764 }
765 
766 /*
767  * Get disk slice, partition, and geometry information.
768  */
769 static int
770 getdiskinfo(int fd, const char *fname, const char *dtype, __unused int oflag,
771 	    struct bpb *bpb)
772 {
773     struct disklabel32 *lp, dlp;
774     struct fd_type type;
775     struct partinfo pi;
776     off_t ms = 0, hs = 0;
777 
778     lp = NULL;
779 
780     /* If the user specified a disk type, try to use that */
781     if (dtype != NULL) {
782 	lp = getdiskbyname(dtype);
783     }
784 
785     /* Maybe it's a floppy drive */
786     if (lp == NULL) {
787 	if (ioctl(fd, DIOCGPART, &pi) == -1) {
788 	    struct stat st;
789 
790 	    if (fstat(fd, &st))
791 		err(1, "cannot get disk size");
792 	    /* create a fake geometry for a file image */
793 	    ms = st.st_size;
794 	    dlp.d_secsize = 512;
795 	    dlp.d_nsectors = 63;
796 	    dlp.d_ntracks = 255;
797 	    dlp.d_secperunit = ms / dlp.d_secsize;
798 	    lp = &dlp;
799 	} else if (ioctl(fd, FD_GTYPE, &type) != -1) {
800 	    ms = pi.media_size;
801 	    dlp.d_secsize = 128 << type.secsize;
802 	    dlp.d_nsectors = type.sectrac;
803 	    dlp.d_ntracks = type.heads;
804 	    dlp.d_secperunit = ms / dlp.d_secsize;
805 	    lp = &dlp;
806 	} else {
807 	    ms = pi.media_size;
808 	}
809     }
810 
811     /* Maybe it's a fixed drive */
812     if (lp == NULL) {
813 	if (ioctl(fd, DIOCGPART, &pi) == - 1)
814 	    err(1, "cannot get disk information");
815 	dlp.d_secsize = pi.media_blksize;
816 	dlp.d_nsectors = pi.d_secpertrack;
817 	dlp.d_ntracks = pi.d_nheads;
818 	if (bpb->bpbBytesPerSec)
819 	    dlp.d_secsize = bpb->bpbBytesPerSec;
820 
821 	dlp.d_secperunit = ms / dlp.d_secsize;
822 
823 	hs = (ms / dlp.d_secsize) - dlp.d_secperunit;
824 	lp = &dlp;
825     }
826 
827     if (bpb->bpbBytesPerSec == 0) {
828 	if (ckgeom(fname, lp->d_secsize, "bytes/sector") == -1)
829 	    return -1;
830 	bpb->bpbBytesPerSec = lp->d_secsize;
831     }
832     if (bpb->bpbSecPerTrack == 0) {
833 	if (ckgeom(fname, lp->d_nsectors, "sectors/track") == -1)
834 	    return -1;
835 	bpb->bpbSecPerTrack = lp->d_nsectors;
836     }
837     if (bpb->bpbHeads == 0) {
838 	if (ckgeom(fname, lp->d_ntracks, "drive heads") == -1)
839 	    return -1;
840 	bpb->bpbHeads = lp->d_ntracks;
841     }
842     if (bpb->bpbHugeSectors == 0)
843 	bpb->bpbHugeSectors = lp->d_secperunit;
844     if (bpb->bpbHiddenSecs == 0)
845 	bpb->bpbHiddenSecs = hs;
846     return 0;
847 }
848 
849 /*
850  * Print out BPB values.
851  */
852 static void
853 print_bpb(struct bpb *bpb)
854 {
855     printf("BytesPerSec=%u SecPerClust=%u ResSectors=%u FATs=%u",
856 	   bpb->bpbBytesPerSec, bpb->bpbSecPerClust, bpb->bpbResSectors,
857 	   bpb->bpbFATs);
858     if (bpb->bpbRootDirEnts)
859 	printf(" RootDirEnts=%u", bpb->bpbRootDirEnts);
860     if (bpb->bpbSectors)
861 	printf(" Sectors=%u", bpb->bpbSectors);
862     printf(" Media=%#x", bpb->bpbMedia);
863     if (bpb->bpbFATsecs)
864 	printf(" FATsecs=%u", bpb->bpbFATsecs);
865     printf(" SecPerTrack=%u Heads=%u HiddenSecs=%u", bpb->bpbSecPerTrack,
866 	   bpb->bpbHeads, bpb->bpbHiddenSecs);
867     if (bpb->bpbHugeSectors)
868 	printf(" HugeSectors=%u", bpb->bpbHugeSectors);
869     if (!bpb->bpbFATsecs) {
870 	printf(" FATsecs=%u RootCluster=%u", bpb->bpbBigFATsecs,
871 	       bpb->bpbRootClust);
872 	printf(" FSInfo=");
873 	printf(bpb->bpbFSInfo == MAXU16 ? "%#x" : "%u", bpb->bpbFSInfo);
874 	printf(" Backup=");
875 	printf(bpb->bpbBackup == MAXU16 ? "%#x" : "%u", bpb->bpbBackup);
876     }
877     printf("\n");
878 }
879 
880 /*
881  * Check a disk geometry value.
882  */
883 static int
884 ckgeom(const char *fname, u_int val, const char *msg)
885 {
886     if (!val) {
887 	warnx("%s: no default %s", fname, msg);
888 	return -1;
889     }
890     if (val > MAXU16) {
891 	warnx("%s: illegal %s %d", fname, msg, val);
892 	return -1;
893     }
894     return 0;
895 }
896 
897 /*
898  * Check a volume label.
899  */
900 static int
901 oklabel(const char *src)
902 {
903     int c, i;
904 
905     for (i = 0; i <= 11; i++) {
906 	c = (u_char)*src++;
907 	if (c < ' ' + !i || strchr("\"*+,./:;<=>?[\\]|", c))
908 	    break;
909     }
910     return i && !c;
911 }
912 
913 /*
914  * Make a volume label.
915  */
916 static void
917 mklabel(u_int8_t *dest, const char *src)
918 {
919     int c, i;
920 
921     for (i = 0; i < 11; i++) {
922 	c = *src ? toupper(*src++) : ' ';
923 	*dest++ = !i && c == '\xe5' ? 5 : c;
924     }
925 }
926 
927 /*
928  * Copy string, padding with spaces.
929  */
930 static void
931 setstr(u_int8_t *dest, const char *src, size_t len)
932 {
933     while (len--)
934 	*dest++ = *src ? *src++ : ' ';
935 }
936 
937 static void
938 infohandler(int sig __unused)
939 {
940 
941 	got_siginfo = 1;
942 }
943