xref: /dragonfly/sbin/newfs_msdos/mkfs_msdos.c (revision b2920380)
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) || (fat != 32 && (o.info_sector || o.backup_sector))) {
351 	warnx("-%c is not a legal FAT%s option",
352 	     fat == 32 ? 'e' : o.info_sector ? 'i' : 'k',
353 	     fat == 32 ? "32" : "12/16");
354 	goto done;
355     }
356     if (o.floppy && fat == 32)
357 	bpb.bpbRootDirEnts = 0;
358     if (fat != 0 && fat != 12 && fat != 16 && fat != 32) {
359 	warnx("%d: bad FAT type", fat);
360 	goto done;
361     }
362 
363     if (o.block_size) {
364 	if (!powerof2(o.block_size)) {
365 	    warnx("block size (%u) is not a power of 2", o.block_size);
366 	    goto done;
367 	}
368 	if (o.block_size < bpb.bpbBytesPerSec) {
369 	    warnx("block size (%u) is too small; minimum is %u",
370 		 o.block_size, bpb.bpbBytesPerSec);
371 	    goto done;
372 	}
373 	if (o.block_size > bpb.bpbBytesPerSec * MAXSPC) {
374 	    warnx("block size (%u) is too large; maximum is %u",
375 		 o.block_size, bpb.bpbBytesPerSec * MAXSPC);
376 	    goto done;
377 	}
378 	bpb.bpbSecPerClust = o.block_size / bpb.bpbBytesPerSec;
379     }
380     if (o.sectors_per_cluster) {
381 	if (!powerof2(o.sectors_per_cluster)) {
382 	    warnx("sectors/cluster (%u) is not a power of 2",
383 		o.sectors_per_cluster);
384 	    goto done;
385 	}
386 	bpb.bpbSecPerClust = o.sectors_per_cluster;
387     }
388     if (o.reserved_sectors)
389 	bpb.bpbResSectors = o.reserved_sectors;
390     if (o.num_FAT) {
391 	if (o.num_FAT > MAXNFT) {
392 	    warnx("number of FATs (%u) is too large; maximum is %u",
393 		 o.num_FAT, MAXNFT);
394 	    goto done;
395 	}
396 	bpb.bpbFATs = o.num_FAT;
397     }
398     if (o.directory_entries)
399 	bpb.bpbRootDirEnts = o.directory_entries;
400     if (o.media_descriptor_set) {
401 	if (o.media_descriptor < 0xf0) {
402 	    warnx("illegal media descriptor (%#x)", o.media_descriptor);
403 	    goto done;
404 	}
405 	bpb.bpbMedia = o.media_descriptor;
406     }
407     if (o.sectors_per_fat)
408 	bpb.bpbBigFATsecs = o.sectors_per_fat;
409     if (o.info_sector)
410 	bpb.bpbFSInfo = o.info_sector;
411     if (o.backup_sector)
412 	bpb.bpbBackup = o.backup_sector;
413     bss = 1;
414     bname = NULL;
415     fd1 = -1;
416     if (o.bootstrap) {
417 	bname = o.bootstrap;
418 	if (!strchr(bname, '/')) {
419 	    snprintf(buf, sizeof(buf), "/boot/%s", bname);
420 	    if (!(bname = strdup(buf))) {
421 		warn(NULL);
422 		goto done;
423 	    }
424 	}
425 	if ((fd1 = open(bname, O_RDONLY)) == -1 || fstat(fd1, &sb)) {
426 	    warn("%s", bname);
427 	    goto done;
428 	}
429 	if (!S_ISREG(sb.st_mode) || sb.st_size % bpb.bpbBytesPerSec ||
430 	    sb.st_size < bpb.bpbBytesPerSec ||
431 	    sb.st_size > bpb.bpbBytesPerSec * MAXU16) {
432 	    warnx("%s: inappropriate file type or format", bname);
433 	    goto done;
434 	}
435 	bss = sb.st_size / bpb.bpbBytesPerSec;
436     }
437     if (!bpb.bpbFATs)
438 	bpb.bpbFATs = 2;
439     if (!fat) {
440 	if (bpb.bpbHugeSectors < (bpb.bpbResSectors ? bpb.bpbResSectors : bss) +
441 	    howmany((RESFTE + (bpb.bpbSecPerClust ? MINCLS16 : MAXCLS12 + 1)) *
442 		(bpb.bpbSecPerClust ? 16 : 12) / BPN,
443 		bpb.bpbBytesPerSec * NPB) *
444 	    bpb.bpbFATs +
445 	    howmany(bpb.bpbRootDirEnts ? bpb.bpbRootDirEnts : DEFRDE,
446 		    bpb.bpbBytesPerSec / sizeof(struct de)) +
447 	    (bpb.bpbSecPerClust ? MINCLS16 : MAXCLS12 + 1) *
448 	    (bpb.bpbSecPerClust ? bpb.bpbSecPerClust :
449 	     howmany(DEFBLK, bpb.bpbBytesPerSec)))
450 	    fat = 12;
451 	else if (bpb.bpbRootDirEnts || bpb.bpbHugeSectors <
452 		 (bpb.bpbResSectors ? bpb.bpbResSectors : bss) +
453 		 howmany((RESFTE + MAXCLS16) * 2, bpb.bpbBytesPerSec) *
454 		 bpb.bpbFATs +
455 		 howmany(DEFRDE, bpb.bpbBytesPerSec / sizeof(struct de)) +
456 		 (MAXCLS16 + 1) *
457 		 (bpb.bpbSecPerClust ? bpb.bpbSecPerClust :
458 		  howmany(8192, bpb.bpbBytesPerSec)))
459 	    fat = 16;
460 	else
461 	    fat = 32;
462     }
463     x = bss;
464     if (fat == 32) {
465 	if (!bpb.bpbFSInfo) {
466 	    if (x == MAXU16 || x == bpb.bpbBackup) {
467 		warnx("no room for info sector");
468 		goto done;
469 	    }
470 	    bpb.bpbFSInfo = x;
471 	}
472 	if (bpb.bpbFSInfo != MAXU16 && x <= bpb.bpbFSInfo)
473 	    x = bpb.bpbFSInfo + 1;
474 	if (!bpb.bpbBackup) {
475 	    if (x == MAXU16) {
476 		warnx("no room for backup sector");
477 		goto done;
478 	    }
479 	    bpb.bpbBackup = x;
480 	} else if (bpb.bpbBackup != MAXU16 && bpb.bpbBackup == bpb.bpbFSInfo) {
481 	    warnx("backup sector would overwrite info sector");
482 	    goto done;
483 	}
484 	if (bpb.bpbBackup != MAXU16 && x <= bpb.bpbBackup)
485 	    x = bpb.bpbBackup + 1;
486     }
487     if (!bpb.bpbResSectors)
488 	bpb.bpbResSectors = fat == 32 ?
489 	    MAX(x, MAX(16384 / bpb.bpbBytesPerSec, 4)) : x;
490     else if (bpb.bpbResSectors < x) {
491 	warnx("too few reserved sectors (need %d have %d)", x,
492 	     bpb.bpbResSectors);
493 	goto done;
494     }
495     if (fat != 32 && !bpb.bpbRootDirEnts)
496 	bpb.bpbRootDirEnts = DEFRDE;
497     rds = howmany(bpb.bpbRootDirEnts, bpb.bpbBytesPerSec / sizeof(struct de));
498     if (!bpb.bpbSecPerClust)
499 	for (bpb.bpbSecPerClust = howmany(fat == 16 ? DEFBLK16 :
500 					  DEFBLK, bpb.bpbBytesPerSec);
501 	     bpb.bpbSecPerClust < MAXSPC &&
502 	     bpb.bpbResSectors +
503 	     howmany((RESFTE + maxcls(fat)) * (fat / BPN),
504 		     bpb.bpbBytesPerSec * NPB) *
505 	     bpb.bpbFATs +
506 	     rds +
507 	     (u_int64_t) (maxcls(fat) + 1) *
508 	     bpb.bpbSecPerClust <= bpb.bpbHugeSectors;
509 	     bpb.bpbSecPerClust <<= 1)
510 	    continue;
511     if (fat != 32 && bpb.bpbBigFATsecs > MAXU16) {
512 	warnx("too many sectors/FAT for FAT12/16");
513 	goto done;
514     }
515     x1 = bpb.bpbResSectors + rds;
516     x = bpb.bpbBigFATsecs ? bpb.bpbBigFATsecs : 1;
517     if (x1 + (u_int64_t)x * bpb.bpbFATs > bpb.bpbHugeSectors) {
518 	warnx("meta data exceeds file system size");
519 	goto done;
520     }
521     x1 += x * bpb.bpbFATs;
522     x = (u_int64_t)(bpb.bpbHugeSectors - x1) * bpb.bpbBytesPerSec * NPB /
523 	(bpb.bpbSecPerClust * bpb.bpbBytesPerSec * NPB + fat /
524 	 BPN * bpb.bpbFATs);
525     x2 = howmany((RESFTE + MIN(x, maxcls(fat))) * (fat / BPN),
526 		 bpb.bpbBytesPerSec * NPB);
527     if (!bpb.bpbBigFATsecs) {
528 	bpb.bpbBigFATsecs = x2;
529 	x1 += (bpb.bpbBigFATsecs - 1) * bpb.bpbFATs;
530     }
531     cls = (bpb.bpbHugeSectors - x1) / bpb.bpbSecPerClust;
532     x = (u_int64_t)bpb.bpbBigFATsecs * bpb.bpbBytesPerSec * NPB / (fat / BPN) -
533 	RESFTE;
534     if (cls > x)
535 	cls = x;
536     if (bpb.bpbBigFATsecs < x2)
537 	warnx("warning: sectors/FAT limits file system to %u clusters",
538 	      cls);
539     if (cls < mincls(fat)) {
540 	warnx("%u clusters too few clusters for FAT%u, need %u", cls, fat,
541 	    mincls(fat));
542 	goto done;
543     }
544     if (cls > maxcls(fat)) {
545 	cls = maxcls(fat);
546 	bpb.bpbHugeSectors = x1 + (cls + 1) * bpb.bpbSecPerClust - 1;
547 	warnx("warning: FAT type limits file system to %u sectors",
548 	      bpb.bpbHugeSectors);
549     }
550     printf("%s: %u sector%s in %u FAT%u cluster%s "
551 	   "(%u bytes/cluster)\n", fname, cls * bpb.bpbSecPerClust,
552 	   cls * bpb.bpbSecPerClust == 1 ? "" : "s", cls, fat,
553 	   cls == 1 ? "" : "s", bpb.bpbBytesPerSec * bpb.bpbSecPerClust);
554     if (!bpb.bpbMedia)
555 	bpb.bpbMedia = !bpb.bpbHiddenSecs ? 0xf0 : 0xf8;
556     if (fat == 32)
557 	bpb.bpbRootClust = RESFTE;
558     if (bpb.bpbHugeSectors <= MAXU16) {
559 	bpb.bpbSectors = bpb.bpbHugeSectors;
560 	bpb.bpbHugeSectors = 0;
561     }
562     if (fat != 32) {
563 	bpb.bpbFATsecs = bpb.bpbBigFATsecs;
564 	bpb.bpbBigFATsecs = 0;
565     }
566     print_bpb(&bpb);
567     if (!o.no_create) {
568 	gettimeofday(&tv, NULL);
569 	now = tv.tv_sec;
570 	tm = localtime(&now);
571 	if (!(img = malloc(bpb.bpbBytesPerSec))) {
572 	    warn(NULL);
573 	    goto done;
574 	}
575 	dir = bpb.bpbResSectors + (bpb.bpbFATsecs ? bpb.bpbFATsecs :
576 				   bpb.bpbBigFATsecs) * bpb.bpbFATs;
577 	memset(&si_sa, 0, sizeof(si_sa));
578 	si_sa.sa_handler = infohandler;
579 	if (sigaction(SIGINFO, &si_sa, NULL) == -1) {
580 	    warn("sigaction SIGINFO");
581 	    goto done;
582 	}
583 	for (lsn = 0; lsn < dir + (fat == 32 ? bpb.bpbSecPerClust : rds); lsn++) {
584 	    if (got_siginfo) {
585 		    fprintf(stderr,"%s: writing sector %u of %u (%u%%)\n",
586 			fname, lsn,
587 			(dir + (fat == 32 ? bpb.bpbSecPerClust: rds)),
588 			(lsn * 100) / (dir +
589 			    (fat == 32 ? bpb.bpbSecPerClust: rds)));
590 		    got_siginfo = 0;
591 	    }
592 	    x = lsn;
593 	    if (o.bootstrap &&
594 		fat == 32 && bpb.bpbBackup != MAXU16 &&
595 		bss <= bpb.bpbBackup && x >= bpb.bpbBackup) {
596 		x -= bpb.bpbBackup;
597 		if (!x && lseek(fd1, o.offset, SEEK_SET)) {
598 		    warn("%s", bname);
599 		    goto done;
600 		}
601 	    }
602 	    if (o.bootstrap && x < bss) {
603 		if ((n = read(fd1, img, bpb.bpbBytesPerSec)) == -1) {
604 		    warn("%s", bname);
605 		    goto done;
606 		}
607 		if ((unsigned)n != bpb.bpbBytesPerSec) {
608 		    warnx("%s: can't read sector %u", bname, x);
609 		    goto done;
610 		}
611 	    } else
612 		memset(img, 0, bpb.bpbBytesPerSec);
613 	    if (!lsn ||
614 		(fat == 32 && bpb.bpbBackup != MAXU16 &&
615 		 lsn == bpb.bpbBackup)) {
616 		x1 = sizeof(struct bs);
617 		bsbpb = (struct bsbpb *)(img + x1);
618 		mk2(bsbpb->bpbBytesPerSec, bpb.bpbBytesPerSec);
619 		mk1(bsbpb->bpbSecPerClust, bpb.bpbSecPerClust);
620 		mk2(bsbpb->bpbResSectors, bpb.bpbResSectors);
621 		mk1(bsbpb->bpbFATs, bpb.bpbFATs);
622 		mk2(bsbpb->bpbRootDirEnts, bpb.bpbRootDirEnts);
623 		mk2(bsbpb->bpbSectors, bpb.bpbSectors);
624 		mk1(bsbpb->bpbMedia, bpb.bpbMedia);
625 		mk2(bsbpb->bpbFATsecs, bpb.bpbFATsecs);
626 		mk2(bsbpb->bpbSecPerTrack, bpb.bpbSecPerTrack);
627 		mk2(bsbpb->bpbHeads, bpb.bpbHeads);
628 		mk4(bsbpb->bpbHiddenSecs, bpb.bpbHiddenSecs);
629 		mk4(bsbpb->bpbHugeSectors, bpb.bpbHugeSectors);
630 		x1 += sizeof(struct bsbpb);
631 		if (fat == 32) {
632 		    bsxbpb = (struct bsxbpb *)(img + x1);
633 		    mk4(bsxbpb->bpbBigFATsecs, bpb.bpbBigFATsecs);
634 		    mk2(bsxbpb->bpbExtFlags, 0);
635 		    mk2(bsxbpb->bpbFSVers, 0);
636 		    mk4(bsxbpb->bpbRootClust, bpb.bpbRootClust);
637 		    mk2(bsxbpb->bpbFSInfo, bpb.bpbFSInfo);
638 		    mk2(bsxbpb->bpbBackup, bpb.bpbBackup);
639 		    x1 += sizeof(struct bsxbpb);
640 		}
641 		bsx = (struct bsx *)(img + x1);
642 		mk1(bsx->exBootSignature, 0x29);
643 		if (o.volume_id_set)
644 		    x = o.volume_id;
645 		else
646 		    x = (((u_int)(1 + tm->tm_mon) << 8 |
647 			  (u_int)tm->tm_mday) +
648 			 ((u_int)tm->tm_sec << 8 |
649 			  (u_int)(tv.tv_usec / 10))) << 16 |
650 			((u_int)(1900 + tm->tm_year) +
651 			 ((u_int)tm->tm_hour << 8 |
652 			  (u_int)tm->tm_min));
653 		mk4(bsx->exVolumeID, x);
654 		mklabel(bsx->exVolumeLabel, o.volume_label ? o.volume_label : "NO NAME");
655 		snprintf(buf, sizeof(buf), "FAT%u", fat);
656 		setstr(bsx->exFileSysType, buf, sizeof(bsx->exFileSysType));
657 		if (!o.bootstrap) {
658 		    x1 += sizeof(struct bsx);
659 		    bs = (struct bs *)img;
660 		    mk1(bs->bsJump[0], 0xeb);
661 		    mk1(bs->bsJump[1], x1 - 2);
662 		    mk1(bs->bsJump[2], 0x90);
663 		    setstr(bs->bsOemName, o.OEM_string ? o.OEM_string : "BSD4.4  ",
664 			   sizeof(bs->bsOemName));
665 		    memcpy(img + x1, bootcode, sizeof(bootcode));
666 		    mk2(img + MINBPS - 2, DOSMAGIC);
667 		}
668 	    } else if (fat == 32 && bpb.bpbFSInfo != MAXU16 &&
669 		       (lsn == bpb.bpbFSInfo ||
670 			(bpb.bpbBackup != MAXU16 &&
671 			 lsn == bpb.bpbBackup + bpb.bpbFSInfo))) {
672 		mk4(img, 0x41615252);
673 		mk4(img + MINBPS - 28, 0x61417272);
674 		mk4(img + MINBPS - 24, 0xffffffff);
675 		mk4(img + MINBPS - 20, bpb.bpbRootClust);
676 		mk2(img + MINBPS - 2, DOSMAGIC);
677 	    } else if (lsn >= bpb.bpbResSectors && lsn < dir &&
678 		       !((lsn - bpb.bpbResSectors) %
679 			 (bpb.bpbFATsecs ? bpb.bpbFATsecs :
680 			  bpb.bpbBigFATsecs))) {
681 		mk1(img[0], bpb.bpbMedia);
682 		for (x = 1; x < fat * (fat == 32 ? 3 : 2) / 8; x++)
683 		    mk1(img[x], fat == 32 && x % 4 == 3 ? 0x0f : 0xff);
684 	    } else if (lsn == dir && o.volume_label) {
685 		de = (struct de *)img;
686 		mklabel(de->deName, o.volume_label);
687 		mk1(de->deAttributes, 050);
688 		x = (u_int)tm->tm_hour << 11 |
689 		    (u_int)tm->tm_min << 5 |
690 		    (u_int)tm->tm_sec >> 1;
691 		mk2(de->deMTime, x);
692 		x = (u_int)(tm->tm_year - 80) << 9 |
693 		    (u_int)(tm->tm_mon + 1) << 5 |
694 		    (u_int)tm->tm_mday;
695 		mk2(de->deMDate, x);
696 	    }
697 	    if ((n = write(fd, img, bpb.bpbBytesPerSec)) == -1) {
698 		warn("%s", fname);
699 		goto done;
700 	    }
701 	    if ((unsigned)n != bpb.bpbBytesPerSec) {
702 		warnx("%s: can't write sector %u", fname, lsn);
703 		goto done;
704 	    }
705 	}
706     }
707     rv = 0;
708 done:
709     free(img);
710 
711     return rv;
712 }
713 
714 /*
715  * return -1 with error if file system is mounted.
716  */
717 static int
718 check_mounted(const char *fname, mode_t mode)
719 {
720     struct statfs *mp;
721     const char *s1, *s2;
722     size_t len;
723     int n, r;
724 
725     if (!(n = getmntinfo(&mp, MNT_NOWAIT))) {
726 	warn("getmntinfo");
727 	return -1;
728     }
729     len = strlen(_PATH_DEV);
730     s1 = fname;
731     if (!strncmp(s1, _PATH_DEV, len))
732 	s1 += len;
733     r = S_ISCHR(mode) && s1 != fname && *s1 == 'r';
734     for (; n--; mp++) {
735 	s2 = mp->f_mntfromname;
736 	if (!strncmp(s2, _PATH_DEV, len))
737 	    s2 += len;
738 	if ((r && s2 != mp->f_mntfromname && !strcmp(s1 + 1, s2)) ||
739 	    !strcmp(s1, s2)) {
740 	    warnx("%s is mounted on %s", fname, mp->f_mntonname);
741 	    return -1;
742 	}
743     }
744     return 0;
745 }
746 
747 /*
748  * Get a standard format.
749  */
750 static int
751 getstdfmt(const char *fmt, struct bpb *bpb)
752 {
753     u_int x, i;
754 
755     x = NELEM(stdfmt);
756     for (i = 0; i < x && strcmp(fmt, stdfmt[i].name); i++);
757     if (i == x) {
758 	warnx("%s: unknown standard format", fmt);
759 	return -1;
760     }
761     *bpb = stdfmt[i].bpb;
762     return 0;
763 }
764 
765 /*
766  * Get disk slice, partition, and geometry information.
767  */
768 static int
769 getdiskinfo(int fd, const char *fname, const char *dtype, __unused int oflag,
770 	    struct bpb *bpb)
771 {
772     struct disklabel32 *lp, dlp;
773     struct fd_type type;
774     struct partinfo pi;
775     off_t ms = 0, hs = 0;
776 
777     lp = NULL;
778 
779     /* If the user specified a disk type, try to use that */
780     if (dtype != NULL) {
781 	lp = getdiskbyname(dtype);
782     }
783 
784     /* Maybe it's a floppy drive */
785     if (lp == NULL) {
786 	if (ioctl(fd, DIOCGPART, &pi) == -1) {
787 	    struct stat st;
788 
789 	    if (fstat(fd, &st))
790 		err(1, "cannot get disk size");
791 	    /* create a fake geometry for a file image */
792 	    ms = st.st_size;
793 	    dlp.d_secsize = 512;
794 	    dlp.d_nsectors = 63;
795 	    dlp.d_ntracks = 255;
796 	    dlp.d_secperunit = ms / dlp.d_secsize;
797 	    lp = &dlp;
798 	} else if (ioctl(fd, FD_GTYPE, &type) != -1) {
799 	    ms = pi.media_size;
800 	    dlp.d_secsize = 128 << type.secsize;
801 	    dlp.d_nsectors = type.sectrac;
802 	    dlp.d_ntracks = type.heads;
803 	    dlp.d_secperunit = ms / dlp.d_secsize;
804 	    lp = &dlp;
805 	} else {
806 	    ms = pi.media_size;
807 	}
808     }
809 
810     /* Maybe it's a fixed drive */
811     if (lp == NULL) {
812 	if (ioctl(fd, DIOCGPART, &pi) == - 1)
813 	    err(1, "cannot get disk information");
814 	dlp.d_secsize = pi.media_blksize;
815 	dlp.d_nsectors = pi.d_secpertrack;
816 	dlp.d_ntracks = pi.d_nheads;
817 	if (bpb->bpbBytesPerSec)
818 	    dlp.d_secsize = bpb->bpbBytesPerSec;
819 
820 	dlp.d_secperunit = ms / dlp.d_secsize;
821 
822 	hs = (ms / dlp.d_secsize) - dlp.d_secperunit;
823 	lp = &dlp;
824     }
825 
826     if (bpb->bpbBytesPerSec == 0) {
827 	if (ckgeom(fname, lp->d_secsize, "bytes/sector") == -1)
828 	    return -1;
829 	bpb->bpbBytesPerSec = lp->d_secsize;
830     }
831     if (bpb->bpbSecPerTrack == 0) {
832 	if (ckgeom(fname, lp->d_nsectors, "sectors/track") == -1)
833 	    return -1;
834 	bpb->bpbSecPerTrack = lp->d_nsectors;
835     }
836     if (bpb->bpbHeads == 0) {
837 	if (ckgeom(fname, lp->d_ntracks, "drive heads") == -1)
838 	    return -1;
839 	bpb->bpbHeads = lp->d_ntracks;
840     }
841     if (bpb->bpbHugeSectors == 0)
842 	bpb->bpbHugeSectors = lp->d_secperunit;
843     if (bpb->bpbHiddenSecs == 0)
844 	bpb->bpbHiddenSecs = hs;
845     return 0;
846 }
847 
848 /*
849  * Print out BPB values.
850  */
851 static void
852 print_bpb(struct bpb *bpb)
853 {
854     printf("BytesPerSec=%u SecPerClust=%u ResSectors=%u FATs=%u",
855 	   bpb->bpbBytesPerSec, bpb->bpbSecPerClust, bpb->bpbResSectors,
856 	   bpb->bpbFATs);
857     if (bpb->bpbRootDirEnts)
858 	printf(" RootDirEnts=%u", bpb->bpbRootDirEnts);
859     if (bpb->bpbSectors)
860 	printf(" Sectors=%u", bpb->bpbSectors);
861     printf(" Media=%#x", bpb->bpbMedia);
862     if (bpb->bpbFATsecs)
863 	printf(" FATsecs=%u", bpb->bpbFATsecs);
864     printf(" SecPerTrack=%u Heads=%u HiddenSecs=%u", bpb->bpbSecPerTrack,
865 	   bpb->bpbHeads, bpb->bpbHiddenSecs);
866     if (bpb->bpbHugeSectors)
867 	printf(" HugeSectors=%u", bpb->bpbHugeSectors);
868     if (!bpb->bpbFATsecs) {
869 	printf(" FATsecs=%u RootCluster=%u", bpb->bpbBigFATsecs,
870 	       bpb->bpbRootClust);
871 	printf(" FSInfo=");
872 	printf(bpb->bpbFSInfo == MAXU16 ? "%#x" : "%u", bpb->bpbFSInfo);
873 	printf(" Backup=");
874 	printf(bpb->bpbBackup == MAXU16 ? "%#x" : "%u", bpb->bpbBackup);
875     }
876     printf("\n");
877 }
878 
879 /*
880  * Check a disk geometry value.
881  */
882 static int
883 ckgeom(const char *fname, u_int val, const char *msg)
884 {
885     if (!val) {
886 	warnx("%s: no default %s", fname, msg);
887 	return -1;
888     }
889     if (val > MAXU16) {
890 	warnx("%s: illegal %s %d", fname, msg, val);
891 	return -1;
892     }
893     return 0;
894 }
895 
896 /*
897  * Check a volume label.
898  */
899 static int
900 oklabel(const char *src)
901 {
902     int c, i;
903 
904     for (i = 0; i <= 11; i++) {
905 	c = (u_char)*src++;
906 	if (c < ' ' + !i || strchr("\"*+,./:;<=>?[\\]|", c))
907 	    break;
908     }
909     return i && !c;
910 }
911 
912 /*
913  * Make a volume label.
914  */
915 static void
916 mklabel(u_int8_t *dest, const char *src)
917 {
918     int c, i;
919 
920     for (i = 0; i < 11; i++) {
921 	c = *src ? toupper(*src++) : ' ';
922 	*dest++ = !i && c == '\xe5' ? 5 : c;
923     }
924 }
925 
926 /*
927  * Copy string, padding with spaces.
928  */
929 static void
930 setstr(u_int8_t *dest, const char *src, size_t len)
931 {
932     while (len--)
933 	*dest++ = *src ? *src++ : ' ';
934 }
935 
936 static void
937 infohandler(int sig __unused)
938 {
939 
940 	got_siginfo = 1;
941 }
942