xref: /freebsd/sbin/newfs_msdos/newfs_msdos.c (revision 2ad872c5794e4c26fdf6ed219ad3f09ca0d5304a)
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 	"$Id: newfs_msdos.c,v 1.6 1998/12/07 14:09:17 rnordier Exp $";
31 #endif /* not lint */
32 
33 #include <sys/param.h>
34 #include <sys/stat.h>
35 #include <sys/diskslice.h>
36 #include <sys/disklabel.h>
37 #include <sys/mount.h>
38 
39 #include <ctype.h>
40 #include <err.h>
41 #include <errno.h>
42 #include <fcntl.h>
43 #include <paths.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <unistd.h>
48 
49 #define MAXU16	  0xffff	/* maximum unsigned 16-bit quantity */
50 #define BPN	  4		/* bits per nibble */
51 #define NPB	  2		/* nibbles per byte */
52 
53 #define DOSMAGIC  0xaa55	/* DOS magic number */
54 #define MINBPS	  128		/* minimum bytes per sector */
55 #define MAXSPC	  128		/* maximum sectors per cluster */
56 #define MAXNFT	  16		/* maximum number of FATs */
57 #define DEFBLK	  4096		/* default block size */
58 #define DEFBLK16  2048		/* default block size FAT16 */
59 #define DEFRDE	  512		/* default root directory entries */
60 #define RESFTE	  2		/* reserved FAT entries */
61 #define MINCLS12  1		/* minimum FAT12 clusters */
62 #define MINCLS16  0x1000	/* minimum FAT16 clusters */
63 #define MINCLS32  2		/* minimum FAT32 clusters */
64 #define MAXCLS12  0xfed 	/* maximum FAT12 clusters */
65 #define MAXCLS16  0xfff5	/* maximum FAT16 clusters */
66 #define MAXCLS32  0xffffff5	/* maximum FAT32 clusters */
67 
68 #define mincls(fat)  ((fat) == 12 ? MINCLS12 :	\
69 		      (fat) == 16 ? MINCLS16 :	\
70 				    MINCLS32)
71 
72 #define maxcls(fat)  ((fat) == 12 ? MAXCLS12 :	\
73 		      (fat) == 16 ? MAXCLS16 :	\
74 				    MAXCLS32)
75 
76 #define mk1(p, x)				\
77     (p) = (u_int8_t)(x)
78 
79 #define mk2(p, x)				\
80     (p)[0] = (u_int8_t)(x),			\
81     (p)[1] = (u_int8_t)((x) >> 010)
82 
83 #define mk4(p, x)				\
84     (p)[0] = (u_int8_t)(x),			\
85     (p)[1] = (u_int8_t)((x) >> 010),		\
86     (p)[2] = (u_int8_t)((x) >> 020),		\
87     (p)[3] = (u_int8_t)((x) >> 030)
88 
89 #define argto1(arg, lo, msg)  argtou(arg, lo, 0xff, msg)
90 #define argto2(arg, lo, msg)  argtou(arg, lo, 0xffff, msg)
91 #define argto4(arg, lo, msg)  argtou(arg, lo, 0xffffffff, msg)
92 #define argtox(arg, lo, msg)  argtou(arg, lo, UINT_MAX, msg)
93 
94 struct bs {
95     u_int8_t jmp[3];		/* bootstrap entry point */
96     u_int8_t oem[8];		/* OEM name and version */
97 };
98 
99 struct bsbpb {
100     u_int8_t bps[2];		/* bytes per sector */
101     u_int8_t spc;		/* sectors per cluster */
102     u_int8_t res[2];		/* reserved sectors */
103     u_int8_t nft;		/* number of FATs */
104     u_int8_t rde[2];		/* root directory entries */
105     u_int8_t sec[2];		/* total sectors */
106     u_int8_t mid;		/* media descriptor */
107     u_int8_t spf[2];		/* sectors per FAT */
108     u_int8_t spt[2];		/* sectors per track */
109     u_int8_t hds[2];		/* drive heads */
110     u_int8_t hid[4];		/* hidden sectors */
111     u_int8_t bsec[4];		/* big total sectors */
112 };
113 
114 struct bsxbpb {
115     u_int8_t bspf[4];		/* big sectors per FAT */
116     u_int8_t xflg[2];		/* FAT control flags */
117     u_int8_t vers[2];		/* file system version */
118     u_int8_t rdcl[4];		/* root directory start cluster */
119     u_int8_t infs[2];		/* file system info sector */
120     u_int8_t bkbs[2];		/* backup boot sector */
121     u_int8_t rsvd[12];		/* reserved */
122 };
123 
124 struct bsx {
125     u_int8_t drv;		/* drive number */
126     u_int8_t rsvd;		/* reserved */
127     u_int8_t sig;		/* extended boot signature */
128     u_int8_t volid[4];		/* volume ID number */
129     u_int8_t label[11]; 	/* volume label */
130     u_int8_t type[8];		/* file system type */
131 };
132 
133 struct de {
134     u_int8_t namext[11];	/* name and extension */
135     u_int8_t attr;		/* attributes */
136     u_int8_t rsvd[10];		/* reserved */
137     u_int8_t time[2];		/* creation time */
138     u_int8_t date[2];		/* creation date */
139     u_int8_t clus[2];		/* starting cluster */
140     u_int8_t size[4];		/* size */
141 };
142 
143 struct bpb {
144     u_int bps;			/* bytes per sector */
145     u_int spc;			/* sectors per cluster */
146     u_int res;			/* reserved sectors */
147     u_int nft;			/* number of FATs */
148     u_int rde;			/* root directory entries */
149     u_int sec;			/* total sectors */
150     u_int mid;			/* media descriptor */
151     u_int spf;			/* sectors per FAT */
152     u_int spt;			/* sectors per track */
153     u_int hds;			/* drive heads */
154     u_int hid;			/* hidden sectors */
155     u_int bsec; 		/* big total sectors */
156     u_int bspf; 		/* big sectors per FAT */
157     u_int rdcl; 		/* root directory start cluster */
158     u_int infs; 		/* file system info sector */
159     u_int bkbs; 		/* backup boot sector */
160 };
161 
162 static struct {
163     const char *name;
164     struct bpb bpb;
165 } stdfmt[] = {
166     {"160",  {512, 1, 1, 2,  64,  320, 0xfe, 1,  8, 1}},
167     {"180",  {512, 1, 1, 2,  64,  360, 0xfc, 2,  9, 1}},
168     {"320",  {512, 2, 1, 2, 112,  640, 0xff, 1,  8, 2}},
169     {"360",  {512, 2, 1, 2, 112,  720, 0xfd, 2,  9, 2}},
170     {"720",  {512, 2, 1, 2, 112, 1440, 0xf9, 3,  9, 2}},
171     {"1200", {512, 1, 1, 2, 224, 2400, 0xf9, 7, 15, 2}},
172     {"1440", {512, 1, 1, 2, 224, 2880, 0xf0, 9, 18, 2}},
173     {"2880", {512, 2, 1, 2, 240, 5760, 0xf0, 9, 36, 2}}
174 };
175 
176 static u_int8_t bootcode[] = {
177     0xfa,			/* cli		    */
178     0x31, 0xc0, 		/* xor	   ax,ax    */
179     0x8e, 0xd0, 		/* mov	   ss,ax    */
180     0xbc, 0x00, 0x7c,		/* mov	   sp,7c00h */
181     0xfb,			/* sti		    */
182     0x8e, 0xd8, 		/* mov	   ds,ax    */
183     0xe8, 0x00, 0x00,		/* call    $ + 3    */
184     0x5e,			/* pop	   si	    */
185     0x83, 0xc6, 0x19,		/* add	   si,+19h  */
186     0xbb, 0x07, 0x00,		/* mov	   bx,0007h */
187     0xfc,			/* cld		    */
188     0xac,			/* lodsb	    */
189     0x84, 0xc0, 		/* test    al,al    */
190     0x74, 0x06, 		/* jz	   $ + 8    */
191     0xb4, 0x0e, 		/* mov	   ah,0eh   */
192     0xcd, 0x10, 		/* int	   10h	    */
193     0xeb, 0xf5, 		/* jmp	   $ - 9    */
194     0x30, 0xe4, 		/* xor	   ah,ah    */
195     0xcd, 0x16, 		/* int	   16h	    */
196     0xcd, 0x19, 		/* int	   19h	    */
197     0x0d, 0x0a,
198     'N', 'o', 'n', '-', 's', 'y', 's', 't',
199     'e', 'm', ' ', 'd', 'i', 's', 'k',
200     0x0d, 0x0a,
201     'P', 'r', 'e', 's', 's', ' ', 'a', 'n',
202     'y', ' ', 'k', 'e', 'y', ' ', 't', 'o',
203     ' ', 'r', 'e', 'b', 'o', 'o', 't',
204     0x0d, 0x0a,
205     0
206 };
207 
208 static void check_mounted(const char *, mode_t);
209 static void getstdfmt(const char *, struct bpb *);
210 static void getdiskinfo(int, const char *, const char *, int,
211 			struct bpb *);
212 static void print_bpb(struct bpb *);
213 static u_int ckgeom(const char *, u_int, const char *);
214 static u_int argtou(const char *, u_int, u_int, const char *);
215 static int oklabel(const char *);
216 static void mklabel(u_int8_t *, const char *);
217 static void setstr(u_int8_t *, const char *, size_t);
218 static void usage(void);
219 
220 /*
221  * Construct a FAT12, FAT16, or FAT32 file system.
222  */
223 int
224 main(int argc, char *argv[])
225 {
226     static char opts[] = "NB:F:I:L:O:S:a:b:c:e:f:h:i:k:m:n:o:r:s:u:";
227     static const char *opt_B, *opt_L, *opt_O, *opt_f;
228     static u_int opt_F, opt_I, opt_S, opt_a, opt_b, opt_c, opt_e;
229     static u_int opt_h, opt_i, opt_k, opt_m, opt_n, opt_o, opt_r;
230     static u_int opt_s, opt_u;
231     static int opt_N;
232     static int Iflag, mflag, oflag;
233     char buf[MAXPATHLEN];
234     struct stat sb;
235     struct timeval tv;
236     struct bpb bpb;
237     struct tm *tm;
238     struct bs *bs;
239     struct bsbpb *bsbpb;
240     struct bsxbpb *bsxbpb;
241     struct bsx *bsx;
242     struct de *de;
243     u_int8_t *img;
244     const char *fname, *dtype, *bname;
245     ssize_t n;
246     time_t now;
247     u_int fat, bss, rds, cls, dir, lsn, x, x1, x2;
248     int ch, fd, fd1;
249 
250     while ((ch = getopt(argc, argv, opts)) != -1)
251 	switch (ch) {
252 	case 'N':
253 	    opt_N = 1;
254 	    break;
255 	case 'B':
256 	    opt_B = optarg;
257 	    break;
258 	case 'F':
259 	    if (strcmp(optarg, "12") &&
260 		strcmp(optarg, "16") &&
261 		strcmp(optarg, "32"))
262 		errx(1, "%s: bad FAT type", optarg);
263 	    opt_F = atoi(optarg);
264 	    break;
265 	case 'I':
266 	    opt_I = argto4(optarg, 0, "volume ID");
267 	    Iflag = 1;
268 	    break;
269 	case 'L':
270 	    if (!oklabel(optarg))
271 		errx(1, "%s: bad volume label", optarg);
272 	    opt_L = optarg;
273 	    break;
274 	case 'O':
275 	    if (strlen(optarg) > 8)
276 		errx(1, "%s: bad OEM string", optarg);
277 	    opt_O = optarg;
278 	    break;
279 	case 'S':
280 	    opt_S = argto2(optarg, 1, "bytes/sector");
281 	    break;
282 	case 'a':
283 	    opt_a = argto4(optarg, 1, "sectors/FAT");
284 	    break;
285 	case 'b':
286 	    opt_b = argtox(optarg, 1, "block size");
287 	    opt_c = 0;
288 	    break;
289 	case 'c':
290 	    opt_c = argto1(optarg, 1, "sectors/cluster");
291 	    opt_b = 0;
292 	    break;
293 	case 'e':
294 	    opt_e = argto2(optarg, 1, "directory entries");
295 	    break;
296 	case 'f':
297 	    opt_f = optarg;
298 	    break;
299 	case 'h':
300 	    opt_h = argto2(optarg, 1, "drive heads");
301 	    break;
302 	case 'i':
303 	    opt_i = argto2(optarg, 1, "info sector");
304 	    break;
305 	case 'k':
306 	    opt_k = argto2(optarg, 1, "backup sector");
307 	    break;
308 	case 'm':
309 	    opt_m = argto1(optarg, 0, "media descriptor");
310 	    mflag = 1;
311 	    break;
312 	case 'n':
313 	    opt_n = argto1(optarg, 1, "number of FATs");
314 	    break;
315 	case 'o':
316 	    opt_o = argto4(optarg, 0, "hidden sectors");
317 	    oflag = 1;
318 	    break;
319 	case 'r':
320 	    opt_r = argto2(optarg, 1, "reserved sectors");
321 	    break;
322 	case 's':
323 	    opt_s = argto4(optarg, 1, "file system size");
324 	    break;
325 	case 'u':
326 	    opt_u = argto2(optarg, 1, "sectors/track");
327 	    break;
328 	default:
329 	    usage();
330 	}
331     argc -= optind;
332     argv += optind;
333     if (argc < 1 || argc > 2)
334 	usage();
335     fname = *argv++;
336     if (!strchr(fname, '/')) {
337 	snprintf(buf, sizeof(buf), "%sr%s", _PATH_DEV, fname);
338 	if (stat(buf, &sb))
339 	    snprintf(buf, sizeof(buf), "%s%s", _PATH_DEV, fname);
340 	if (!(fname = strdup(buf)))
341 	    err(1, NULL);
342     }
343     dtype = *argv;
344     if ((fd = open(fname, opt_N ? O_RDONLY : O_RDWR)) == -1 ||
345 	fstat(fd, &sb))
346 	err(1, "%s", fname);
347     if (!opt_N)
348 	check_mounted(fname, sb.st_mode);
349     if (!S_ISCHR(sb.st_mode))
350 	warnx("warning: %s is not a character device", fname);
351     memset(&bpb, 0, sizeof(bpb));
352     if (opt_f) {
353 	getstdfmt(opt_f, &bpb);
354 	bpb.bsec = bpb.sec;
355 	bpb.sec = 0;
356 	bpb.bspf = bpb.spf;
357 	bpb.spf = 0;
358     }
359     if (opt_h)
360 	bpb.hds = opt_h;
361     if (opt_u)
362 	bpb.spt = opt_u;
363     if (opt_S)
364 	bpb.bps = opt_S;
365     if (opt_s)
366 	bpb.bsec = opt_s;
367     if (oflag)
368 	bpb.hid = opt_o;
369     if (!(opt_f || (opt_h && opt_u && opt_S && opt_s && oflag)))
370 	getdiskinfo(fd, fname, dtype, oflag, &bpb);
371     if (!powerof2(bpb.bps))
372 	errx(1, "bytes/sector (%u) is not a power of 2", bpb.bps);
373     if (bpb.bps < MINBPS)
374 	errx(1, "bytes/sector (%u) is too small; minimum is %u",
375 	     bpb.bps, MINBPS);
376     if (!(fat = opt_F))
377 	if (opt_f)
378 	    fat = 12;
379 	else if (!opt_e && (opt_i || opt_k))
380 	    fat = 32;
381     if ((fat == 32 && opt_e) || (fat != 32 && (opt_i || opt_k)))
382 	errx(1, "-%c is not a legal FAT%s option",
383 	     fat == 32 ? 'e' : opt_i ? 'i' : 'k',
384 	     fat == 32 ? "32" : "12/16");
385     if (opt_f && fat == 32)
386 	bpb.rde = 0;
387     if (opt_b) {
388 	if (!powerof2(opt_b))
389 	    errx(1, "block size (%u) is not a power of 2", opt_b);
390 	if (opt_b < bpb.bps)
391 	    errx(1, "block size (%u) is too small; minimum is %u",
392 		 opt_b, bpb.bps);
393 	if (opt_b > bpb.bps * MAXSPC)
394 	    errx(1, "block size (%u) is too large; maximum is %u",
395 		 opt_b, bpb.bps * MAXSPC);
396 	bpb.spc = opt_b / bpb.bps;
397     }
398     if (opt_c) {
399 	if (!powerof2(opt_c))
400 	    errx(1, "sectors/cluster (%u) is not a power of 2", opt_c);
401 	bpb.spc = opt_c;
402     }
403     if (opt_r)
404 	bpb.res = opt_r;
405     if (opt_n) {
406 	if (opt_n > MAXNFT)
407 	    errx(1, "number of FATs (%u) is too large; maximum is %u",
408 		 opt_n, MAXNFT);
409 	bpb.nft = opt_n;
410     }
411     if (opt_e)
412 	bpb.rde = opt_e;
413     if (mflag) {
414 	if (opt_m < 0xf0)
415 	    errx(1, "illegal media descriptor (%#x)", opt_m);
416 	bpb.mid = opt_m;
417     }
418     if (opt_a)
419 	bpb.bspf = opt_a;
420     if (opt_i)
421 	bpb.infs = opt_i;
422     if (opt_k)
423 	bpb.bkbs = opt_k;
424     bss = 1;
425     bname = NULL;
426     fd1 = -1;
427     if (opt_B) {
428 	bname = opt_B;
429 	if (!strchr(bname, '/')) {
430 	    snprintf(buf, sizeof(buf), "/boot/%s", bname);
431 	    if (!(bname = strdup(buf)))
432 		err(1, NULL);
433 	}
434 	if ((fd1 = open(bname, O_RDONLY)) == -1 || fstat(fd1, &sb))
435 	    err(1, "%s", bname);
436 	if (!S_ISREG(sb.st_mode) || sb.st_size % bpb.bps ||
437 	    sb.st_size < bpb.bps || sb.st_size > bpb.bps * MAXU16)
438 	    errx(1, "%s: inappropriate file type or format", bname);
439 	bss = sb.st_size / bpb.bps;
440     }
441     if (!bpb.nft)
442 	bpb.nft = 2;
443     if (!fat)
444 	if (bpb.bsec < (bpb.res ? bpb.res : bss) +
445 	    howmany((RESFTE + (bpb.spc ? MINCLS16 : MAXCLS12 + 1)) *
446 		    ((bpb.spc ? 16 : 12) / BPN), bpb.bps * NPB) *
447 	    bpb.nft +
448 	    howmany(bpb.rde ? bpb.rde : DEFRDE,
449 		    bpb.bps / sizeof(struct de)) +
450 	    (bpb.spc ? MINCLS16 : MAXCLS12 + 1) *
451 	    (bpb.spc ? bpb.spc : howmany(DEFBLK, bpb.bps)))
452 	    fat = 12;
453 	else if (bpb.rde || bpb.bsec <
454 		 (bpb.res ? bpb.res : bss) +
455 		 howmany((RESFTE + MAXCLS16) * 2, bpb.bps) * bpb.nft +
456 		 howmany(DEFRDE, bpb.bps / sizeof(struct de)) +
457 		 (MAXCLS16 + 1) *
458 		 (bpb.spc ? bpb.spc : howmany(8192, bpb.bps)))
459 	    fat = 16;
460 	else
461 	    fat = 32;
462     x = bss;
463     if (fat == 32) {
464 	if (!bpb.infs) {
465 	    if (x == MAXU16 || x == bpb.bkbs)
466 		errx(1, "no room for info sector");
467 	    bpb.infs = x;
468 	}
469 	if (bpb.infs != MAXU16 && x <= bpb.infs)
470 	    x = bpb.infs + 1;
471 	if (!bpb.bkbs) {
472 	    if (x == MAXU16)
473 		errx(1, "no room for backup sector");
474 	    bpb.bkbs = x;
475 	} else if (bpb.bkbs != MAXU16 && bpb.bkbs == bpb.infs)
476 	    errx(1, "backup sector would overwrite info sector");
477 	if (bpb.bkbs != MAXU16 && x <= bpb.bkbs)
478 	    x = bpb.bkbs + 1;
479     }
480     if (!bpb.res)
481 	bpb.res = fat == 32 ? MAX(x, MAX(16384 / bpb.bps, 4)) : x;
482     else if (bpb.res < x)
483 	errx(1, "too few reserved sectors");
484     if (fat != 32 && !bpb.rde)
485 	bpb.rde = DEFRDE;
486     rds = howmany(bpb.rde, bpb.bps / sizeof(struct de));
487     if (!bpb.spc)
488 	for (bpb.spc = howmany(fat == 16 ? DEFBLK16 : DEFBLK, bpb.bps);
489 	     bpb.spc < MAXSPC &&
490 	     bpb.res +
491 	     howmany((RESFTE + maxcls(fat)) * (fat / BPN),
492 		     bpb.bps * NPB) * bpb.nft +
493 	     rds +
494 	     (u_int64_t)(maxcls(fat) + 1) * bpb.spc <= bpb.bsec;
495 	     bpb.spc <<= 1);
496     if (fat != 32 && bpb.bspf > MAXU16)
497 	errx(1, "too many sectors/FAT for FAT12/16");
498     x1 = bpb.res + rds;
499     x = bpb.bspf ? bpb.bspf : 1;
500     if (x1 + (u_int64_t)x * bpb.nft > bpb.bsec)
501 	errx(1, "meta data exceeds file system size");
502     x1 += x * bpb.nft;
503     x = (u_int64_t)(bpb.bsec - x1) * bpb.bps * NPB /
504 	(bpb.spc * bpb.bps * NPB + fat / BPN * bpb.nft);
505     x2 = howmany((RESFTE + MIN(x, maxcls(fat))) * (fat / BPN),
506 		 bpb.bps * NPB);
507     if (!bpb.bspf) {
508 	bpb.bspf = x2;
509 	x1 += (bpb.bspf - 1) * bpb.nft;
510     }
511     cls = (bpb.bsec - x1) / bpb.spc;
512     x = (u_int64_t)bpb.bspf * bpb.bps * NPB / (fat / BPN) - RESFTE;
513     if (cls > x)
514 	cls = x;
515     if (bpb.bspf < x2)
516 	warnx("warning: sectors/FAT limits file system to %u clusters",
517 	      cls);
518     if (cls < mincls(fat))
519 	errx(1, "too few clusters for FAT%u", fat);
520     if (cls > maxcls(fat)) {
521 	cls = maxcls(fat);
522 	bpb.bsec = x1 + (cls + 1) * bpb.spc - 1;
523 	warnx("warning: FAT type limits file system to %u sectors",
524 	      bpb.bsec);
525     }
526     printf("%s: %u sector%s in %u FAT%u cluster%s "
527 	   "(%u bytes/cluster)\n", fname, cls * bpb.spc,
528 	   cls * bpb.spc == 1 ? "" : "s", cls, fat,
529 	   cls == 1 ? "" : "s", bpb.bps * bpb.spc);
530     if (!bpb.mid)
531 	bpb.mid = !bpb.hid ? 0xf0 : 0xf8;
532     if (fat == 32)
533 	bpb.rdcl = RESFTE;
534     if (bpb.hid + bpb.bsec <= MAXU16) {
535 	bpb.sec = bpb.bsec;
536 	bpb.bsec = 0;
537     }
538     if (fat != 32) {
539 	bpb.spf = bpb.bspf;
540 	bpb.bspf = 0;
541     }
542     print_bpb(&bpb);
543     if (!opt_N) {
544 	gettimeofday(&tv, NULL);
545 	now = tv.tv_sec;
546 	tm = localtime(&now);
547 	if (!(img = malloc(bpb.bps)))
548 	    err(1, NULL);
549 	dir = bpb.res + (bpb.spf ? bpb.spf : bpb.bspf) * bpb.nft;
550 	for (lsn = 0; lsn < dir + (fat == 32 ? bpb.spc : rds); lsn++) {
551 	    x = lsn;
552 	    if (opt_B &&
553 		fat == 32 && bpb.bkbs != MAXU16 &&
554 		bss <= bpb.bkbs && x >= bpb.bkbs) {
555 		x -= bpb.bkbs;
556 		if (!x && lseek(fd1, 0, SEEK_SET))
557 		    err(1, "%s", bname);
558 	    }
559 	    if (opt_B && x < bss) {
560 		if ((n = read(fd1, img, bpb.bps)) == -1)
561 		    err(1, "%s", bname);
562 		if (n != bpb.bps)
563 		    errx(1, "%s: can't read sector %u", bname, x);
564 	    } else
565 		memset(img, 0, bpb.bps);
566 	    if (!lsn ||
567 	      (fat == 32 && bpb.bkbs != MAXU16 && lsn == bpb.bkbs)) {
568 		x1 = sizeof(struct bs);
569 		bsbpb = (struct bsbpb *)(img + x1);
570 		mk2(bsbpb->bps, bpb.bps);
571 		mk1(bsbpb->spc, bpb.spc);
572 		mk2(bsbpb->res, bpb.res);
573 		mk1(bsbpb->nft, bpb.nft);
574 		mk2(bsbpb->rde, bpb.rde);
575 		mk2(bsbpb->sec, bpb.sec);
576 		mk1(bsbpb->mid, bpb.mid);
577 		mk2(bsbpb->spf, bpb.spf);
578 		mk2(bsbpb->spt, bpb.spt);
579 		mk2(bsbpb->hds, bpb.hds);
580 		mk4(bsbpb->hid, bpb.hid);
581 		mk4(bsbpb->bsec, bpb.bsec);
582 		x1 += sizeof(struct bsbpb);
583 		if (fat == 32) {
584 		    bsxbpb = (struct bsxbpb *)(img + x1);
585 		    mk4(bsxbpb->bspf, bpb.bspf);
586 		    mk2(bsxbpb->xflg, 0);
587 		    mk2(bsxbpb->vers, 0);
588 		    mk4(bsxbpb->rdcl, bpb.rdcl);
589 		    mk2(bsxbpb->infs, bpb.infs);
590 		    mk2(bsxbpb->bkbs, bpb.bkbs);
591 		    x1 += sizeof(struct bsxbpb);
592 		}
593 		bsx = (struct bsx *)(img + x1);
594 		mk1(bsx->sig, 0x29);
595 		if (Iflag)
596 		    x = opt_I;
597 		else
598 		    x = (((u_int)(1 + tm->tm_mon) << 8 |
599 			  (u_int)tm->tm_mday) +
600 			 ((u_int)tm->tm_sec << 8 |
601 			  (u_int)(tv.tv_usec / 10))) << 16 |
602 			((u_int)(1900 + tm->tm_year) +
603 			 ((u_int)tm->tm_hour << 8 |
604 			  (u_int)tm->tm_min));
605 		mk4(bsx->volid, x);
606 		mklabel(bsx->label, opt_L ? opt_L : "NO NAME");
607 		sprintf(buf, "FAT%u", fat);
608 		setstr(bsx->type, buf, sizeof(bsx->type));
609 		if (!opt_B) {
610 		    x1 += sizeof(struct bsx);
611 		    bs = (struct bs *)img;
612 		    mk1(bs->jmp[0], 0xeb);
613 		    mk1(bs->jmp[1], x1 - 2);
614 		    mk1(bs->jmp[2], 0x90);
615 		    setstr(bs->oem, opt_O ? opt_O : "BSD  4.4",
616 			   sizeof(bs->oem));
617 		    memcpy(img + x1, bootcode, sizeof(bootcode));
618 		    mk2(img + bpb.bps - 2, DOSMAGIC);
619 		}
620 	    } else if (fat == 32 && bpb.infs != MAXU16 &&
621 		       (lsn == bpb.infs ||
622 			(bpb.bkbs != MAXU16 &&
623 			 lsn == bpb.bkbs + bpb.infs))) {
624 		mk4(img, 0x41615252);
625 		mk4(img + bpb.bps - 28, 0x61417272);
626 		mk4(img + bpb.bps - 24, 0xffffffff);
627 		mk4(img + bpb.bps - 20, bpb.rdcl);
628 		mk2(img + bpb.bps - 2, DOSMAGIC);
629 	    } else if (lsn >= bpb.res && lsn < dir &&
630 		       !((lsn - bpb.res) %
631 			 (bpb.spf ? bpb.spf : bpb.bspf))) {
632 		mk1(img[0], bpb.mid);
633 		for (x = 1; x < fat * (fat == 32 ? 3 : 2) / 8; x++)
634 		    mk1(img[x], fat == 32 && x % 4 == 3 ? 0x0f : 0xff);
635 	    } else if (lsn == dir && opt_L) {
636 		de = (struct de *)img;
637 		mklabel(de->namext, opt_L);
638 		mk1(de->attr, 050);
639 		x = (u_int)tm->tm_hour << 11 |
640 		    (u_int)tm->tm_min << 5 |
641 		    (u_int)tm->tm_sec >> 1;
642 		mk2(de->time, x);
643 		x = (u_int)(tm->tm_year - 80) << 9 |
644 		    (u_int)(tm->tm_mon + 1) << 5 |
645 		    (u_int)tm->tm_mday;
646 		mk2(de->date, x);
647 	    }
648 	    if ((n = write(fd, img, bpb.bps)) == -1)
649 		err(1, "%s", fname);
650 	    if (n != bpb.bps)
651 		errx(1, "%s: can't write sector %u", fname, lsn);
652 	}
653     }
654     return 0;
655 }
656 
657 /*
658  * Exit with error if file system is mounted.
659  */
660 static void
661 check_mounted(const char *fname, mode_t mode)
662 {
663     struct statfs *mp;
664     const char *s1, *s2;
665     size_t len;
666     int n, r;
667 
668     if (!(n = getmntinfo(&mp, MNT_NOWAIT)))
669 	err(1, "getmntinfo");
670     len = strlen(_PATH_DEV);
671     s1 = fname;
672     if (!strncmp(s1, _PATH_DEV, len))
673 	s1 += len;
674     r = S_ISCHR(mode) && s1 != fname && *s1 == 'r';
675     for (; n--; mp++) {
676 	s2 = mp->f_mntfromname;
677 	if (!strncmp(s2, _PATH_DEV, len))
678 	    s2 += len;
679 	if ((r && s2 != mp->f_mntfromname && !strcmp(s1 + 1, s2)) ||
680 	    !strcmp(s1, s2))
681 	    errx(1, "%s is mounted on %s", fname, mp->f_mntonname);
682     }
683 }
684 
685 /*
686  * Get a standard format.
687  */
688 static void
689 getstdfmt(const char *fmt, struct bpb *bpb)
690 {
691     u_int x, i;
692 
693     x = sizeof(stdfmt) / sizeof(stdfmt[0]);
694     for (i = 0; i < x && strcmp(fmt, stdfmt[i].name); i++);
695     if (i == x)
696 	errx(1, "%s: unknown standard format", fmt);
697     *bpb = stdfmt[i].bpb;
698 }
699 
700 /*
701  * Get disk slice, partition, and geometry information.
702  */
703 static void
704 getdiskinfo(int fd, const char *fname, const char *dtype, int oflag,
705 	    struct bpb *bpb)
706 {
707     struct diskslices ds;
708     struct disklabel dl, *lp;
709     const char *s1, *s2;
710     char *s;
711     int slice, part, fd1, i, e;
712 
713     slice = part = -1;
714     s1 = fname;
715     if ((s2 = strrchr(s1, '/')))
716 	s1 = s2 + 1;
717     for (s2 = s1; *s2 && !isdigit(*s2); s2++);
718     if (!*s2 || s2 == s1)
719 	s2 = NULL;
720     else
721 	while (isdigit(*++s2));
722     s1 = s2;
723     if (s2 && *s2 == 's') {
724 	slice = strtol(s2 + 1, &s, 10);
725 	if (slice < 1 || slice > MAX_SLICES - BASE_SLICE)
726 	    s2 = NULL;
727 	else {
728 	    slice = BASE_SLICE + slice - 1;
729 	    s2 = s;
730 	}
731     }
732     if (s2 && *s2 >= 'a' && *s2 <= 'a' + MAXPARTITIONS - 1) {
733 	if (slice == -1)
734 	    slice = COMPATIBILITY_SLICE;
735 	part = *s2++ - 'a';
736     }
737     if (!s2 || (*s2 && *s2 != '.'))
738 	errx(1, "%s: can't figure out partition info", fname);
739     if (slice != -1 && (!oflag || (!bpb->bsec && part == -1))) {
740 	if (ioctl(fd, DIOCGSLICEINFO, &ds) == -1) {
741 	    warn("ioctl (GSLICEINFO)");
742 	    errx(1, "%s: can't get slice info", fname);
743 	}
744 	if (slice >= ds.dss_nslices || !ds.dss_slices[slice].ds_size)
745 	    errx(1, "%s: slice is unavailable", fname);
746 	if (!oflag)
747 	    bpb->hid = ds.dss_slices[slice].ds_offset;
748 	if (!bpb->bsec && part == -1)
749 	    bpb->bsec = ds.dss_slices[slice].ds_size;
750     }
751     if (((slice == -1 || part != -1) &&
752 	 ((!oflag && part != -1) || !bpb->bsec)) ||
753 	!bpb->bps || !bpb->spt || !bpb->hds) {
754 	lp = &dl;
755 	i = ioctl(fd, DIOCGDINFO, lp);
756 	if (i == -1 && slice != -1 && part == -1) {
757 	    e = errno;
758 	    if (!(s = strdup(fname)))
759 		err(1, NULL);
760 	    s[s1 - fname] = 0;
761 	    if ((fd1 = open(s, O_RDONLY)) != -1) {
762 		i = ioctl(fd1, DIOCGDINFO, lp);
763 		close(fd1);
764 	    }
765 	    free(s);
766 	    errno = e;
767 	}
768 	if (i == -1)
769 	    if (!dtype) {
770 		warn("ioctl (GDINFO)");
771 		errx(1, "%s: can't read disk label; "
772 		     "disk type must be specified", fname);
773 	    } else if (!(lp = getdiskbyname(dtype)))
774 		errx(1, "%s: unknown disk type", dtype);
775 	if (slice == -1 || part != -1) {
776 	    if (part == -1)
777 		part = RAW_PART;
778 	    if (part >= lp->d_npartitions ||
779 		!lp->d_partitions[part].p_size)
780 		errx(1, "%s: partition is unavailable", fname);
781 	    if (!oflag && part != -1)
782 		bpb->hid += lp->d_partitions[part].p_offset;
783 	    if (!bpb->bsec)
784 		bpb->bsec = lp->d_partitions[part].p_size;
785 	}
786 	if (!bpb->bps)
787 	    bpb->bps = ckgeom(fname, lp->d_secsize, "bytes/sector");
788 	if (!bpb->spt)
789 	    bpb->spt = ckgeom(fname, lp->d_nsectors, "sectors/track");
790 	if (!bpb->hds)
791 	    bpb->hds = ckgeom(fname, lp->d_ntracks, "drive heads");
792     }
793 }
794 
795 /*
796  * Print out BPB values.
797  */
798 static void
799 print_bpb(struct bpb *bpb)
800 {
801     printf("bps=%u spc=%u res=%u nft=%u", bpb->bps, bpb->spc, bpb->res,
802 	   bpb->nft);
803     if (bpb->rde)
804 	printf(" rde=%u", bpb->rde);
805     if (bpb->sec)
806 	printf(" sec=%u", bpb->sec);
807     printf(" mid=%#x", bpb->mid);
808     if (bpb->spf)
809 	printf(" spf=%u", bpb->spf);
810     printf(" spt=%u hds=%u hid=%u", bpb->spt, bpb->hds, bpb->hid);
811     if (bpb->bsec)
812 	printf(" bsec=%u", bpb->bsec);
813     if (!bpb->spf) {
814 	printf(" bspf=%u rdcl=%u", bpb->bspf, bpb->rdcl);
815 	printf(" infs=");
816 	printf(bpb->infs == MAXU16 ? "%#x" : "%u", bpb->infs);
817 	printf(" bkbs=");
818 	printf(bpb->bkbs == MAXU16 ? "%#x" : "%u", bpb->bkbs);
819     }
820     printf("\n");
821 }
822 
823 /*
824  * Check a disk geometry value.
825  */
826 static u_int
827 ckgeom(const char *fname, u_int val, const char *msg)
828 {
829     if (!val)
830 	errx(1, "%s: no default %s", fname, msg);
831     if (val > MAXU16)
832 	errx(1, "%s: illegal %s", fname, msg);
833     return val;
834 }
835 
836 /*
837  * Convert and check a numeric option argument.
838  */
839 static u_int
840 argtou(const char *arg, u_int lo, u_int hi, const char *msg)
841 {
842     char *s;
843     u_long x;
844 
845     errno = 0;
846     x = strtoul(arg, &s, 0);
847     if (errno || !*arg || *s || x < lo || x > hi)
848 	errx(1, "%s: bad %s", arg, msg);
849     return x;
850 }
851 
852 /*
853  * Check a volume label.
854  */
855 static int
856 oklabel(const char *src)
857 {
858     int c, i;
859 
860     for (i = 0; i <= 11; i++) {
861 	c = (u_char)*src++;
862 	if (c < ' ' + !i || strchr("\"*+,./:;<=>?[\\]|", c))
863 	    break;
864     }
865     return i && !c;
866 }
867 
868 /*
869  * Make a volume label.
870  */
871 static void
872 mklabel(u_int8_t *dest, const char *src)
873 {
874     int c, i;
875 
876     for (i = 0; i < 11; i++) {
877 	c = *src ? toupper(*src++) : ' ';
878 	*dest++ = !i && c == '\xe5' ? 5 : c;
879     }
880 }
881 
882 /*
883  * Copy string, padding with spaces.
884  */
885 static void
886 setstr(u_int8_t *dest, const char *src, size_t len)
887 {
888     while (len--)
889 	*dest++ = *src ? *src++ : ' ';
890 }
891 
892 /*
893  * Print usage message.
894  */
895 static void
896 usage(void)
897 {
898     fprintf(stderr,
899 	    "usage: newfs_msdos [ -options ] special [disktype]\n");
900     fprintf(stderr, "where the options are:\n");
901     fprintf(stderr, "\t-N don't create file system: "
902 	    "just print out parameters\n");
903     fprintf(stderr, "\t-B get bootstrap from file\n");
904     fprintf(stderr, "\t-F FAT type (12, 16, or 32)\n");
905     fprintf(stderr, "\t-I volume ID\n");
906     fprintf(stderr, "\t-L volume label\n");
907     fprintf(stderr, "\t-O OEM string\n");
908     fprintf(stderr, "\t-S bytes/sector\n");
909     fprintf(stderr, "\t-a sectors/FAT\n");
910     fprintf(stderr, "\t-b block size\n");
911     fprintf(stderr, "\t-c sectors/cluster\n");
912     fprintf(stderr, "\t-e root directory entries\n");
913     fprintf(stderr, "\t-f standard format\n");
914     fprintf(stderr, "\t-h drive heads\n");
915     fprintf(stderr, "\t-i file system info sector\n");
916     fprintf(stderr, "\t-k backup boot sector\n");
917     fprintf(stderr, "\t-m media descriptor\n");
918     fprintf(stderr, "\t-n number of FATs\n");
919     fprintf(stderr, "\t-o hidden sectors\n");
920     fprintf(stderr, "\t-r reserved sectors\n");
921     fprintf(stderr, "\t-s file system size (sectors)\n");
922     fprintf(stderr, "\t-u sectors/track\n");
923     exit(1);
924 }
925