xref: /freebsd/sbin/newfs_msdos/newfs_msdos.c (revision 6b3455a7665208c366849f0b2b3bc916fb97516e)
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 
28 #ifndef lint
29 static const char rcsid[] =
30   "$FreeBSD$";
31 #endif /* not lint */
32 
33 #include <sys/param.h>
34 #include <sys/fdcio.h>
35 #include <sys/disk.h>
36 #include <sys/disklabel.h>
37 #include <sys/mount.h>
38 #include <sys/stat.h>
39 #include <sys/time.h>
40 
41 #include <ctype.h>
42 #include <err.h>
43 #include <errno.h>
44 #include <fcntl.h>
45 #include <paths.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <time.h>
50 #include <unistd.h>
51 
52 #define MAXU16	  0xffff	/* maximum unsigned 16-bit quantity */
53 #define BPN	  4		/* bits per nibble */
54 #define NPB	  2		/* nibbles per byte */
55 
56 #define DOSMAGIC  0xaa55	/* DOS magic number */
57 #define MINBPS	  128		/* minimum bytes per sector */
58 #define MAXSPC	  128		/* maximum sectors per cluster */
59 #define MAXNFT	  16		/* maximum number of FATs */
60 #define DEFBLK	  4096		/* default block size */
61 #define DEFBLK16  2048		/* default block size FAT16 */
62 #define DEFRDE	  512		/* default root directory entries */
63 #define RESFTE	  2		/* reserved FAT entries */
64 #define MINCLS12  1		/* minimum FAT12 clusters */
65 #define MINCLS16  0x1000	/* minimum FAT16 clusters */
66 #define MINCLS32  2		/* minimum FAT32 clusters */
67 #define MAXCLS12  0xfed 	/* maximum FAT12 clusters */
68 #define MAXCLS16  0xfff5	/* maximum FAT16 clusters */
69 #define MAXCLS32  0xffffff5	/* maximum FAT32 clusters */
70 
71 #define mincls(fat)  ((fat) == 12 ? MINCLS12 :	\
72 		      (fat) == 16 ? MINCLS16 :	\
73 				    MINCLS32)
74 
75 #define maxcls(fat)  ((fat) == 12 ? MAXCLS12 :	\
76 		      (fat) == 16 ? MAXCLS16 :	\
77 				    MAXCLS32)
78 
79 #define mk1(p, x)				\
80     (p) = (u_int8_t)(x)
81 
82 #define mk2(p, x)				\
83     (p)[0] = (u_int8_t)(x),			\
84     (p)[1] = (u_int8_t)((x) >> 010)
85 
86 #define mk4(p, x)				\
87     (p)[0] = (u_int8_t)(x),			\
88     (p)[1] = (u_int8_t)((x) >> 010),		\
89     (p)[2] = (u_int8_t)((x) >> 020),		\
90     (p)[3] = (u_int8_t)((x) >> 030)
91 
92 #define argto1(arg, lo, msg)  argtou(arg, lo, 0xff, msg)
93 #define argto2(arg, lo, msg)  argtou(arg, lo, 0xffff, msg)
94 #define argto4(arg, lo, msg)  argtou(arg, lo, 0xffffffff, msg)
95 #define argtox(arg, lo, msg)  argtou(arg, lo, UINT_MAX, msg)
96 
97 struct bs {
98     u_int8_t jmp[3];		/* bootstrap entry point */
99     u_int8_t oem[8];		/* OEM name and version */
100 };
101 
102 struct bsbpb {
103     u_int8_t bps[2];		/* bytes per sector */
104     u_int8_t spc;		/* sectors per cluster */
105     u_int8_t res[2];		/* reserved sectors */
106     u_int8_t nft;		/* number of FATs */
107     u_int8_t rde[2];		/* root directory entries */
108     u_int8_t sec[2];		/* total sectors */
109     u_int8_t mid;		/* media descriptor */
110     u_int8_t spf[2];		/* sectors per FAT */
111     u_int8_t spt[2];		/* sectors per track */
112     u_int8_t hds[2];		/* drive heads */
113     u_int8_t hid[4];		/* hidden sectors */
114     u_int8_t bsec[4];		/* big total sectors */
115 };
116 
117 struct bsxbpb {
118     u_int8_t bspf[4];		/* big sectors per FAT */
119     u_int8_t xflg[2];		/* FAT control flags */
120     u_int8_t vers[2];		/* file system version */
121     u_int8_t rdcl[4];		/* root directory start cluster */
122     u_int8_t infs[2];		/* file system info sector */
123     u_int8_t bkbs[2];		/* backup boot sector */
124     u_int8_t rsvd[12];		/* reserved */
125 };
126 
127 struct bsx {
128     u_int8_t drv;		/* drive number */
129     u_int8_t rsvd;		/* reserved */
130     u_int8_t sig;		/* extended boot signature */
131     u_int8_t volid[4];		/* volume ID number */
132     u_int8_t label[11]; 	/* volume label */
133     u_int8_t type[8];		/* file system type */
134 };
135 
136 struct de {
137     u_int8_t namext[11];	/* name and extension */
138     u_int8_t attr;		/* attributes */
139     u_int8_t rsvd[10];		/* reserved */
140     u_int8_t time[2];		/* creation time */
141     u_int8_t date[2];		/* creation date */
142     u_int8_t clus[2];		/* starting cluster */
143     u_int8_t size[4];		/* size */
144 };
145 
146 struct bpb {
147     u_int bps;			/* bytes per sector */
148     u_int spc;			/* sectors per cluster */
149     u_int res;			/* reserved sectors */
150     u_int nft;			/* number of FATs */
151     u_int rde;			/* root directory entries */
152     u_int sec;			/* total sectors */
153     u_int mid;			/* media descriptor */
154     u_int spf;			/* sectors per FAT */
155     u_int spt;			/* sectors per track */
156     u_int hds;			/* drive heads */
157     u_int hid;			/* hidden sectors */
158     u_int bsec; 		/* big total sectors */
159     u_int bspf; 		/* big sectors per FAT */
160     u_int rdcl; 		/* root directory start cluster */
161     u_int infs; 		/* file system info sector */
162     u_int bkbs; 		/* backup boot sector */
163 };
164 
165 static struct {
166     const char *name;
167     struct bpb bpb;
168 } stdfmt[] = {
169     {"160",  {512, 1, 1, 2,  64,  320, 0xfe, 1,  8, 1}},
170     {"180",  {512, 1, 1, 2,  64,  360, 0xfc, 2,  9, 1}},
171     {"320",  {512, 2, 1, 2, 112,  640, 0xff, 1,  8, 2}},
172     {"360",  {512, 2, 1, 2, 112,  720, 0xfd, 2,  9, 2}},
173     {"640",  {512, 2, 1, 2, 112, 1280, 0xfb, 2,  8, 2}},
174     {"720",  {512, 2, 1, 2, 112, 1440, 0xf9, 3,  9, 2}},
175     {"1200", {512, 1, 1, 2, 224, 2400, 0xf9, 7, 15, 2}},
176     {"1232", {1024,1, 1, 2, 192, 1232, 0xfe, 2,  8, 2}},
177     {"1440", {512, 1, 1, 2, 224, 2880, 0xf0, 9, 18, 2}},
178     {"2880", {512, 2, 1, 2, 240, 5760, 0xf0, 9, 36, 2}}
179 };
180 
181 static 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 void check_mounted(const char *, mode_t);
214 static void getstdfmt(const char *, struct bpb *);
215 static void getdiskinfo(int, const char *, const char *, int,
216 			struct bpb *);
217 static void print_bpb(struct bpb *);
218 static u_int ckgeom(const char *, u_int, const char *);
219 static u_int argtou(const char *, u_int, u_int, const char *);
220 static int oklabel(const char *);
221 static void mklabel(u_int8_t *, const char *);
222 static void setstr(u_int8_t *, const char *, size_t);
223 static void usage(void);
224 
225 /*
226  * Construct a FAT12, FAT16, or FAT32 file system.
227  */
228 int
229 main(int argc, char *argv[])
230 {
231     static char opts[] = "NB:F:I:L:O:S:a:b:c:e:f:h:i:k:m:n:o:r:s:u:";
232     static const char *opt_B, *opt_L, *opt_O, *opt_f;
233     static u_int opt_F, opt_I, opt_S, opt_a, opt_b, opt_c, opt_e;
234     static u_int opt_h, opt_i, opt_k, opt_m, opt_n, opt_o, opt_r;
235     static u_int opt_s, opt_u;
236     static int opt_N;
237     static int Iflag, mflag, oflag;
238     char buf[MAXPATHLEN];
239     struct stat sb;
240     struct timeval tv;
241     struct bpb bpb;
242     struct tm *tm;
243     struct bs *bs;
244     struct bsbpb *bsbpb;
245     struct bsxbpb *bsxbpb;
246     struct bsx *bsx;
247     struct de *de;
248     u_int8_t *img;
249     const char *fname, *dtype, *bname;
250     ssize_t n;
251     time_t now;
252     u_int fat, bss, rds, cls, dir, lsn, x, x1, x2;
253     int ch, fd, fd1;
254 
255     while ((ch = getopt(argc, argv, opts)) != -1)
256 	switch (ch) {
257 	case 'N':
258 	    opt_N = 1;
259 	    break;
260 	case 'B':
261 	    opt_B = optarg;
262 	    break;
263 	case 'F':
264 	    if (strcmp(optarg, "12") &&
265 		strcmp(optarg, "16") &&
266 		strcmp(optarg, "32"))
267 		errx(1, "%s: bad FAT type", optarg);
268 	    opt_F = atoi(optarg);
269 	    break;
270 	case 'I':
271 	    opt_I = argto4(optarg, 0, "volume ID");
272 	    Iflag = 1;
273 	    break;
274 	case 'L':
275 	    if (!oklabel(optarg))
276 		errx(1, "%s: bad volume label", optarg);
277 	    opt_L = optarg;
278 	    break;
279 	case 'O':
280 	    if (strlen(optarg) > 8)
281 		errx(1, "%s: bad OEM string", optarg);
282 	    opt_O = optarg;
283 	    break;
284 	case 'S':
285 	    opt_S = argto2(optarg, 1, "bytes/sector");
286 	    break;
287 	case 'a':
288 	    opt_a = argto4(optarg, 1, "sectors/FAT");
289 	    break;
290 	case 'b':
291 	    opt_b = argtox(optarg, 1, "block size");
292 	    opt_c = 0;
293 	    break;
294 	case 'c':
295 	    opt_c = argto1(optarg, 1, "sectors/cluster");
296 	    opt_b = 0;
297 	    break;
298 	case 'e':
299 	    opt_e = argto2(optarg, 1, "directory entries");
300 	    break;
301 	case 'f':
302 	    opt_f = optarg;
303 	    break;
304 	case 'h':
305 	    opt_h = argto2(optarg, 1, "drive heads");
306 	    break;
307 	case 'i':
308 	    opt_i = argto2(optarg, 1, "info sector");
309 	    break;
310 	case 'k':
311 	    opt_k = argto2(optarg, 1, "backup sector");
312 	    break;
313 	case 'm':
314 	    opt_m = argto1(optarg, 0, "media descriptor");
315 	    mflag = 1;
316 	    break;
317 	case 'n':
318 	    opt_n = argto1(optarg, 1, "number of FATs");
319 	    break;
320 	case 'o':
321 	    opt_o = argto4(optarg, 0, "hidden sectors");
322 	    oflag = 1;
323 	    break;
324 	case 'r':
325 	    opt_r = argto2(optarg, 1, "reserved sectors");
326 	    break;
327 	case 's':
328 	    opt_s = argto4(optarg, 1, "file system size");
329 	    break;
330 	case 'u':
331 	    opt_u = argto2(optarg, 1, "sectors/track");
332 	    break;
333 	default:
334 	    usage();
335 	}
336     argc -= optind;
337     argv += optind;
338     if (argc < 1 || argc > 2)
339 	usage();
340     fname = *argv++;
341     if (!strchr(fname, '/')) {
342 	snprintf(buf, sizeof(buf), "%s%s", _PATH_DEV, fname);
343 	if (!(fname = strdup(buf)))
344 	    err(1, NULL);
345     }
346     dtype = *argv;
347     if ((fd = open(fname, opt_N ? O_RDONLY : O_RDWR)) == -1 ||
348 	fstat(fd, &sb))
349 	err(1, "%s", fname);
350     if (!opt_N)
351 	check_mounted(fname, sb.st_mode);
352     if (!S_ISCHR(sb.st_mode))
353 	warnx("warning: %s is not a character device", fname);
354     memset(&bpb, 0, sizeof(bpb));
355     if (opt_f) {
356 	getstdfmt(opt_f, &bpb);
357 	bpb.bsec = bpb.sec;
358 	bpb.sec = 0;
359 	bpb.bspf = bpb.spf;
360 	bpb.spf = 0;
361     }
362     if (opt_h)
363 	bpb.hds = opt_h;
364     if (opt_u)
365 	bpb.spt = opt_u;
366     if (opt_S)
367 	bpb.bps = opt_S;
368     if (opt_s)
369 	bpb.bsec = opt_s;
370     if (oflag)
371 	bpb.hid = opt_o;
372     if (!(opt_f || (opt_h && opt_u && opt_S && opt_s && oflag)))
373 	getdiskinfo(fd, fname, dtype, oflag, &bpb);
374     if (!powerof2(bpb.bps))
375 	errx(1, "bytes/sector (%u) is not a power of 2", bpb.bps);
376     if (bpb.bps < MINBPS)
377 	errx(1, "bytes/sector (%u) is too small; minimum is %u",
378 	     bpb.bps, MINBPS);
379     if (!(fat = opt_F)) {
380 	if (opt_f)
381 	    fat = 12;
382 	else if (!opt_e && (opt_i || opt_k))
383 	    fat = 32;
384     }
385     if ((fat == 32 && opt_e) || (fat != 32 && (opt_i || opt_k)))
386 	errx(1, "-%c is not a legal FAT%s option",
387 	     fat == 32 ? 'e' : opt_i ? 'i' : 'k',
388 	     fat == 32 ? "32" : "12/16");
389     if (opt_f && fat == 32)
390 	bpb.rde = 0;
391     if (opt_b) {
392 	if (!powerof2(opt_b))
393 	    errx(1, "block size (%u) is not a power of 2", opt_b);
394 	if (opt_b < bpb.bps)
395 	    errx(1, "block size (%u) is too small; minimum is %u",
396 		 opt_b, bpb.bps);
397 	if (opt_b > bpb.bps * MAXSPC)
398 	    errx(1, "block size (%u) is too large; maximum is %u",
399 		 opt_b, bpb.bps * MAXSPC);
400 	bpb.spc = opt_b / bpb.bps;
401     }
402     if (opt_c) {
403 	if (!powerof2(opt_c))
404 	    errx(1, "sectors/cluster (%u) is not a power of 2", opt_c);
405 	bpb.spc = opt_c;
406     }
407     if (opt_r)
408 	bpb.res = opt_r;
409     if (opt_n) {
410 	if (opt_n > MAXNFT)
411 	    errx(1, "number of FATs (%u) is too large; maximum is %u",
412 		 opt_n, MAXNFT);
413 	bpb.nft = opt_n;
414     }
415     if (opt_e)
416 	bpb.rde = opt_e;
417     if (mflag) {
418 	if (opt_m < 0xf0)
419 	    errx(1, "illegal media descriptor (%#x)", opt_m);
420 	bpb.mid = opt_m;
421     }
422     if (opt_a)
423 	bpb.bspf = opt_a;
424     if (opt_i)
425 	bpb.infs = opt_i;
426     if (opt_k)
427 	bpb.bkbs = opt_k;
428     bss = 1;
429     bname = NULL;
430     fd1 = -1;
431     if (opt_B) {
432 	bname = opt_B;
433 	if (!strchr(bname, '/')) {
434 	    snprintf(buf, sizeof(buf), "/boot/%s", bname);
435 	    if (!(bname = strdup(buf)))
436 		err(1, NULL);
437 	}
438 	if ((fd1 = open(bname, O_RDONLY)) == -1 || fstat(fd1, &sb))
439 	    err(1, "%s", bname);
440 	if (!S_ISREG(sb.st_mode) || sb.st_size % bpb.bps ||
441 	    sb.st_size < bpb.bps || sb.st_size > bpb.bps * MAXU16)
442 	    errx(1, "%s: inappropriate file type or format", bname);
443 	bss = sb.st_size / bpb.bps;
444     }
445     if (!bpb.nft)
446 	bpb.nft = 2;
447     if (!fat) {
448 	if (bpb.bsec < (bpb.res ? bpb.res : bss) +
449 	    howmany((RESFTE + (bpb.spc ? MINCLS16 : MAXCLS12 + 1)) *
450 		    ((bpb.spc ? 16 : 12) / BPN), bpb.bps * NPB) *
451 	    bpb.nft +
452 	    howmany(bpb.rde ? bpb.rde : DEFRDE,
453 		    bpb.bps / sizeof(struct de)) +
454 	    (bpb.spc ? MINCLS16 : MAXCLS12 + 1) *
455 	    (bpb.spc ? bpb.spc : howmany(DEFBLK, bpb.bps)))
456 	    fat = 12;
457 	else if (bpb.rde || bpb.bsec <
458 		 (bpb.res ? bpb.res : bss) +
459 		 howmany((RESFTE + MAXCLS16) * 2, bpb.bps) * bpb.nft +
460 		 howmany(DEFRDE, bpb.bps / sizeof(struct de)) +
461 		 (MAXCLS16 + 1) *
462 		 (bpb.spc ? bpb.spc : howmany(8192, bpb.bps)))
463 	    fat = 16;
464 	else
465 	    fat = 32;
466     }
467     x = bss;
468     if (fat == 32) {
469 	if (!bpb.infs) {
470 	    if (x == MAXU16 || x == bpb.bkbs)
471 		errx(1, "no room for info sector");
472 	    bpb.infs = x;
473 	}
474 	if (bpb.infs != MAXU16 && x <= bpb.infs)
475 	    x = bpb.infs + 1;
476 	if (!bpb.bkbs) {
477 	    if (x == MAXU16)
478 		errx(1, "no room for backup sector");
479 	    bpb.bkbs = x;
480 	} else if (bpb.bkbs != MAXU16 && bpb.bkbs == bpb.infs)
481 	    errx(1, "backup sector would overwrite info sector");
482 	if (bpb.bkbs != MAXU16 && x <= bpb.bkbs)
483 	    x = bpb.bkbs + 1;
484     }
485     if (!bpb.res)
486 	bpb.res = fat == 32 ? MAX(x, MAX(16384 / bpb.bps, 4)) : x;
487     else if (bpb.res < x)
488 	errx(1, "too few reserved sectors");
489     if (fat != 32 && !bpb.rde)
490 	bpb.rde = DEFRDE;
491     rds = howmany(bpb.rde, bpb.bps / sizeof(struct de));
492     if (!bpb.spc)
493 	for (bpb.spc = howmany(fat == 16 ? DEFBLK16 : DEFBLK, bpb.bps);
494 	     bpb.spc < MAXSPC &&
495 	     bpb.res +
496 	     howmany((RESFTE + maxcls(fat)) * (fat / BPN),
497 		     bpb.bps * NPB) * bpb.nft +
498 	     rds +
499 	     (u_int64_t)(maxcls(fat) + 1) * bpb.spc <= bpb.bsec;
500 	     bpb.spc <<= 1);
501     if (fat != 32 && bpb.bspf > MAXU16)
502 	errx(1, "too many sectors/FAT for FAT12/16");
503     x1 = bpb.res + rds;
504     x = bpb.bspf ? bpb.bspf : 1;
505     if (x1 + (u_int64_t)x * bpb.nft > bpb.bsec)
506 	errx(1, "meta data exceeds file system size");
507     x1 += x * bpb.nft;
508     x = (u_int64_t)(bpb.bsec - x1) * bpb.bps * NPB /
509 	(bpb.spc * bpb.bps * NPB + fat / BPN * bpb.nft);
510     x2 = howmany((RESFTE + MIN(x, maxcls(fat))) * (fat / BPN),
511 		 bpb.bps * NPB);
512     if (!bpb.bspf) {
513 	bpb.bspf = x2;
514 	x1 += (bpb.bspf - 1) * bpb.nft;
515     }
516     cls = (bpb.bsec - x1) / bpb.spc;
517     x = (u_int64_t)bpb.bspf * bpb.bps * NPB / (fat / BPN) - RESFTE;
518     if (cls > x)
519 	cls = x;
520     if (bpb.bspf < x2)
521 	warnx("warning: sectors/FAT limits file system to %u clusters",
522 	      cls);
523     if (cls < mincls(fat))
524 	errx(1, "%u clusters too few clusters for FAT%u, need %u", cls, fat,
525 	    mincls(fat));
526     if (cls > maxcls(fat)) {
527 	cls = maxcls(fat);
528 	bpb.bsec = x1 + (cls + 1) * bpb.spc - 1;
529 	warnx("warning: FAT type limits file system to %u sectors",
530 	      bpb.bsec);
531     }
532     printf("%s: %u sector%s in %u FAT%u cluster%s "
533 	   "(%u bytes/cluster)\n", fname, cls * bpb.spc,
534 	   cls * bpb.spc == 1 ? "" : "s", cls, fat,
535 	   cls == 1 ? "" : "s", bpb.bps * bpb.spc);
536     if (!bpb.mid)
537 	bpb.mid = !bpb.hid ? 0xf0 : 0xf8;
538     if (fat == 32)
539 	bpb.rdcl = RESFTE;
540     if (bpb.hid + bpb.bsec <= MAXU16) {
541 	bpb.sec = bpb.bsec;
542 	bpb.bsec = 0;
543     }
544     if (fat != 32) {
545 	bpb.spf = bpb.bspf;
546 	bpb.bspf = 0;
547     }
548     print_bpb(&bpb);
549     if (!opt_N) {
550 	gettimeofday(&tv, NULL);
551 	now = tv.tv_sec;
552 	tm = localtime(&now);
553 	if (!(img = malloc(bpb.bps)))
554 	    err(1, NULL);
555 	dir = bpb.res + (bpb.spf ? bpb.spf : bpb.bspf) * bpb.nft;
556 	for (lsn = 0; lsn < dir + (fat == 32 ? bpb.spc : rds); lsn++) {
557 	    x = lsn;
558 	    if (opt_B &&
559 		fat == 32 && bpb.bkbs != MAXU16 &&
560 		bss <= bpb.bkbs && x >= bpb.bkbs) {
561 		x -= bpb.bkbs;
562 		if (!x && lseek(fd1, 0, SEEK_SET))
563 		    err(1, "%s", bname);
564 	    }
565 	    if (opt_B && x < bss) {
566 		if ((n = read(fd1, img, bpb.bps)) == -1)
567 		    err(1, "%s", bname);
568 		if (n != bpb.bps)
569 		    errx(1, "%s: can't read sector %u", bname, x);
570 	    } else
571 		memset(img, 0, bpb.bps);
572 	    if (!lsn ||
573 	      (fat == 32 && bpb.bkbs != MAXU16 && lsn == bpb.bkbs)) {
574 		x1 = sizeof(struct bs);
575 		bsbpb = (struct bsbpb *)(img + x1);
576 		mk2(bsbpb->bps, bpb.bps);
577 		mk1(bsbpb->spc, bpb.spc);
578 		mk2(bsbpb->res, bpb.res);
579 		mk1(bsbpb->nft, bpb.nft);
580 		mk2(bsbpb->rde, bpb.rde);
581 		mk2(bsbpb->sec, bpb.sec);
582 		mk1(bsbpb->mid, bpb.mid);
583 		mk2(bsbpb->spf, bpb.spf);
584 		mk2(bsbpb->spt, bpb.spt);
585 		mk2(bsbpb->hds, bpb.hds);
586 		mk4(bsbpb->hid, bpb.hid);
587 		mk4(bsbpb->bsec, bpb.bsec);
588 		x1 += sizeof(struct bsbpb);
589 		if (fat == 32) {
590 		    bsxbpb = (struct bsxbpb *)(img + x1);
591 		    mk4(bsxbpb->bspf, bpb.bspf);
592 		    mk2(bsxbpb->xflg, 0);
593 		    mk2(bsxbpb->vers, 0);
594 		    mk4(bsxbpb->rdcl, bpb.rdcl);
595 		    mk2(bsxbpb->infs, bpb.infs);
596 		    mk2(bsxbpb->bkbs, bpb.bkbs);
597 		    x1 += sizeof(struct bsxbpb);
598 		}
599 		bsx = (struct bsx *)(img + x1);
600 		mk1(bsx->sig, 0x29);
601 		if (Iflag)
602 		    x = opt_I;
603 		else
604 		    x = (((u_int)(1 + tm->tm_mon) << 8 |
605 			  (u_int)tm->tm_mday) +
606 			 ((u_int)tm->tm_sec << 8 |
607 			  (u_int)(tv.tv_usec / 10))) << 16 |
608 			((u_int)(1900 + tm->tm_year) +
609 			 ((u_int)tm->tm_hour << 8 |
610 			  (u_int)tm->tm_min));
611 		mk4(bsx->volid, x);
612 		mklabel(bsx->label, opt_L ? opt_L : "NO NAME");
613 		sprintf(buf, "FAT%u", fat);
614 		setstr(bsx->type, buf, sizeof(bsx->type));
615 		if (!opt_B) {
616 		    x1 += sizeof(struct bsx);
617 		    bs = (struct bs *)img;
618 		    mk1(bs->jmp[0], 0xeb);
619 		    mk1(bs->jmp[1], x1 - 2);
620 		    mk1(bs->jmp[2], 0x90);
621 		    setstr(bs->oem, opt_O ? opt_O : "BSD  4.4",
622 			   sizeof(bs->oem));
623 		    memcpy(img + x1, bootcode, sizeof(bootcode));
624 		    mk2(img + bpb.bps - 2, DOSMAGIC);
625 		}
626 	    } else if (fat == 32 && bpb.infs != MAXU16 &&
627 		       (lsn == bpb.infs ||
628 			(bpb.bkbs != MAXU16 &&
629 			 lsn == bpb.bkbs + bpb.infs))) {
630 		mk4(img, 0x41615252);
631 		mk4(img + bpb.bps - 28, 0x61417272);
632 		mk4(img + bpb.bps - 24, 0xffffffff);
633 		mk4(img + bpb.bps - 20, bpb.rdcl);
634 		mk2(img + bpb.bps - 2, DOSMAGIC);
635 	    } else if (lsn >= bpb.res && lsn < dir &&
636 		       !((lsn - bpb.res) %
637 			 (bpb.spf ? bpb.spf : bpb.bspf))) {
638 		mk1(img[0], bpb.mid);
639 		for (x = 1; x < fat * (fat == 32 ? 3 : 2) / 8; x++)
640 		    mk1(img[x], fat == 32 && x % 4 == 3 ? 0x0f : 0xff);
641 	    } else if (lsn == dir && opt_L) {
642 		de = (struct de *)img;
643 		mklabel(de->namext, opt_L);
644 		mk1(de->attr, 050);
645 		x = (u_int)tm->tm_hour << 11 |
646 		    (u_int)tm->tm_min << 5 |
647 		    (u_int)tm->tm_sec >> 1;
648 		mk2(de->time, x);
649 		x = (u_int)(tm->tm_year - 80) << 9 |
650 		    (u_int)(tm->tm_mon + 1) << 5 |
651 		    (u_int)tm->tm_mday;
652 		mk2(de->date, x);
653 	    }
654 	    if ((n = write(fd, img, bpb.bps)) == -1)
655 		err(1, "%s", fname);
656 	    if (n != bpb.bps)
657 		errx(1, "%s: can't write sector %u", fname, lsn);
658 	}
659     }
660     return 0;
661 }
662 
663 /*
664  * Exit with error if file system is mounted.
665  */
666 static void
667 check_mounted(const char *fname, mode_t mode)
668 {
669     struct statfs *mp;
670     const char *s1, *s2;
671     size_t len;
672     int n, r;
673 
674     if (!(n = getmntinfo(&mp, MNT_NOWAIT)))
675 	err(1, "getmntinfo");
676     len = strlen(_PATH_DEV);
677     s1 = fname;
678     if (!strncmp(s1, _PATH_DEV, len))
679 	s1 += len;
680     r = S_ISCHR(mode) && s1 != fname && *s1 == 'r';
681     for (; n--; mp++) {
682 	s2 = mp->f_mntfromname;
683 	if (!strncmp(s2, _PATH_DEV, len))
684 	    s2 += len;
685 	if ((r && s2 != mp->f_mntfromname && !strcmp(s1 + 1, s2)) ||
686 	    !strcmp(s1, s2))
687 	    errx(1, "%s is mounted on %s", fname, mp->f_mntonname);
688     }
689 }
690 
691 /*
692  * Get a standard format.
693  */
694 static void
695 getstdfmt(const char *fmt, struct bpb *bpb)
696 {
697     u_int x, i;
698 
699     x = sizeof(stdfmt) / sizeof(stdfmt[0]);
700     for (i = 0; i < x && strcmp(fmt, stdfmt[i].name); i++);
701     if (i == x)
702 	errx(1, "%s: unknown standard format", fmt);
703     *bpb = stdfmt[i].bpb;
704 }
705 
706 /*
707  * Get disk slice, partition, and geometry information.
708  */
709 static void
710 getdiskinfo(int fd, const char *fname, const char *dtype, int oflag,
711 	    struct bpb *bpb)
712 {
713     struct disklabel *lp, dlp;
714     struct fd_type type;
715     off_t ms, hs;
716 
717     lp = NULL;
718 
719     /* If the user specified a disk type, try to use that */
720     if (dtype != NULL) {
721 	lp = getdiskbyname(dtype);
722 	hs = 0;
723     }
724 
725     /* Maybe it's a floppy drive */
726     if (lp == NULL) {
727 	if (ioctl(fd, DIOCGMEDIASIZE, &ms) == -1)
728 	    errx(1, "Cannot get disk size, %s", strerror(errno));
729 	if (ioctl(fd, FD_GTYPE, &type) != -1) {
730 	    dlp.d_secsize = 128 << type.secsize;
731 	    dlp.d_nsectors = type.sectrac;
732 	    dlp.d_ntracks = type.heads;
733 	    dlp.d_secperunit = ms / dlp.d_secsize;
734 	    lp = &dlp;
735 	    hs = 0;
736 	}
737     }
738 
739     /* Maybe it's a fixed drive */
740     if (lp == NULL) {
741 	if (ioctl(fd, DIOCGDINFO, &dlp) == -1) {
742 	    if (ioctl(fd, DIOCGSECTORSIZE, &dlp.d_secsize) == -1)
743 		errx(1, "Cannot get sector size, %s", strerror(errno));
744 	    if (ioctl(fd, DIOCGFWSECTORS, &dlp.d_nsectors) == -1)
745 		errx(1, "Cannot get number of sectors, %s", strerror(errno));
746 	    if (ioctl(fd, DIOCGFWHEADS, &dlp.d_ntracks)== -1)
747 		errx(1, "Cannot get number of heads, %s", strerror(errno));
748 	    dlp.d_secperunit = ms / dlp.d_secsize;
749 	}
750 
751 	hs = (ms / dlp.d_secsize) - dlp.d_secperunit;
752 	lp = &dlp;
753     }
754 
755     if (bpb->bps == 0)
756 	bpb->bps = ckgeom(fname, lp->d_secsize, "bytes/sector");
757     if (bpb->spt == 0)
758 	bpb->spt = ckgeom(fname, lp->d_nsectors, "sectors/track");
759     if (bpb->hds == 0)
760 	bpb->hds = ckgeom(fname, lp->d_ntracks, "drive heads");
761     if (bpb->bsec == 0)
762 	bpb->bsec = lp->d_secperunit;
763     if (bpb->hid == 0)
764 	bpb->hid = hs;
765 }
766 
767 /*
768  * Print out BPB values.
769  */
770 static void
771 print_bpb(struct bpb *bpb)
772 {
773     printf("bps=%u spc=%u res=%u nft=%u", bpb->bps, bpb->spc, bpb->res,
774 	   bpb->nft);
775     if (bpb->rde)
776 	printf(" rde=%u", bpb->rde);
777     if (bpb->sec)
778 	printf(" sec=%u", bpb->sec);
779     printf(" mid=%#x", bpb->mid);
780     if (bpb->spf)
781 	printf(" spf=%u", bpb->spf);
782     printf(" spt=%u hds=%u hid=%u", bpb->spt, bpb->hds, bpb->hid);
783     if (bpb->bsec)
784 	printf(" bsec=%u", bpb->bsec);
785     if (!bpb->spf) {
786 	printf(" bspf=%u rdcl=%u", bpb->bspf, bpb->rdcl);
787 	printf(" infs=");
788 	printf(bpb->infs == MAXU16 ? "%#x" : "%u", bpb->infs);
789 	printf(" bkbs=");
790 	printf(bpb->bkbs == MAXU16 ? "%#x" : "%u", bpb->bkbs);
791     }
792     printf("\n");
793 }
794 
795 /*
796  * Check a disk geometry value.
797  */
798 static u_int
799 ckgeom(const char *fname, u_int val, const char *msg)
800 {
801     if (!val)
802 	errx(1, "%s: no default %s", fname, msg);
803     if (val > MAXU16)
804 	errx(1, "%s: illegal %s %d", fname, msg, val);
805     return val;
806 }
807 
808 /*
809  * Convert and check a numeric option argument.
810  */
811 static u_int
812 argtou(const char *arg, u_int lo, u_int hi, const char *msg)
813 {
814     char *s;
815     u_long x;
816 
817     errno = 0;
818     x = strtoul(arg, &s, 0);
819     if (errno || !*arg || *s || x < lo || x > hi)
820 	errx(1, "%s: bad %s", arg, msg);
821     return x;
822 }
823 
824 /*
825  * Check a volume label.
826  */
827 static int
828 oklabel(const char *src)
829 {
830     int c, i;
831 
832     for (i = 0; i <= 11; i++) {
833 	c = (u_char)*src++;
834 	if (c < ' ' + !i || strchr("\"*+,./:;<=>?[\\]|", c))
835 	    break;
836     }
837     return i && !c;
838 }
839 
840 /*
841  * Make a volume label.
842  */
843 static void
844 mklabel(u_int8_t *dest, const char *src)
845 {
846     int c, i;
847 
848     for (i = 0; i < 11; i++) {
849 	c = *src ? toupper(*src++) : ' ';
850 	*dest++ = !i && c == '\xe5' ? 5 : c;
851     }
852 }
853 
854 /*
855  * Copy string, padding with spaces.
856  */
857 static void
858 setstr(u_int8_t *dest, const char *src, size_t len)
859 {
860     while (len--)
861 	*dest++ = *src ? *src++ : ' ';
862 }
863 
864 /*
865  * Print usage message.
866  */
867 static void
868 usage(void)
869 {
870     fprintf(stderr,
871 	    "usage: newfs_msdos [ -options ] special [disktype]\n");
872     fprintf(stderr, "where the options are:\n");
873     fprintf(stderr, "\t-N don't create file system: "
874 	    "just print out parameters\n");
875     fprintf(stderr, "\t-B get bootstrap from file\n");
876     fprintf(stderr, "\t-F FAT type (12, 16, or 32)\n");
877     fprintf(stderr, "\t-I volume ID\n");
878     fprintf(stderr, "\t-L volume label\n");
879     fprintf(stderr, "\t-O OEM string\n");
880     fprintf(stderr, "\t-S bytes/sector\n");
881     fprintf(stderr, "\t-a sectors/FAT\n");
882     fprintf(stderr, "\t-b block size\n");
883     fprintf(stderr, "\t-c sectors/cluster\n");
884     fprintf(stderr, "\t-e root directory entries\n");
885     fprintf(stderr, "\t-f standard format\n");
886     fprintf(stderr, "\t-h drive heads\n");
887     fprintf(stderr, "\t-i file system info sector\n");
888     fprintf(stderr, "\t-k backup boot sector\n");
889     fprintf(stderr, "\t-m media descriptor\n");
890     fprintf(stderr, "\t-n number of FATs\n");
891     fprintf(stderr, "\t-o hidden sectors\n");
892     fprintf(stderr, "\t-r reserved sectors\n");
893     fprintf(stderr, "\t-s file system size (sectors)\n");
894     fprintf(stderr, "\t-u sectors/track\n");
895     exit(1);
896 }
897