xref: /freebsd/sbin/newfs_msdos/newfs_msdos.c (revision eb6d21b4ca6d668cf89afd99eef7baeafa712197)
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 <inttypes.h>
46 #include <paths.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <time.h>
51 #include <unistd.h>
52 
53 #define MAXU16	  0xffff	/* maximum unsigned 16-bit quantity */
54 #define BPN	  4		/* bits per nibble */
55 #define NPB	  2		/* nibbles per byte */
56 
57 #define DOSMAGIC  0xaa55	/* DOS magic number */
58 #define MINBPS	  512		/* minimum bytes per sector */
59 #define MAXSPC	  128		/* maximum sectors per cluster */
60 #define MAXNFT	  16		/* maximum number of FATs */
61 #define DEFBLK	  4096		/* default block size */
62 #define DEFBLK16  2048		/* default block size FAT16 */
63 #define DEFRDE	  512		/* default root directory entries */
64 #define RESFTE	  2		/* reserved FAT entries */
65 #define MINCLS12  1		/* minimum FAT12 clusters */
66 #define MINCLS16  0x1000	/* minimum FAT16 clusters */
67 #define MINCLS32  2		/* minimum FAT32 clusters */
68 #define MAXCLS12  0xfed 	/* maximum FAT12 clusters */
69 #define MAXCLS16  0xfff5	/* maximum FAT16 clusters */
70 #define MAXCLS32  0xffffff5	/* maximum FAT32 clusters */
71 
72 #define mincls(fat)  ((fat) == 12 ? MINCLS12 :	\
73 		      (fat) == 16 ? MINCLS16 :	\
74 				    MINCLS32)
75 
76 #define maxcls(fat)  ((fat) == 12 ? MAXCLS12 :	\
77 		      (fat) == 16 ? MAXCLS16 :	\
78 				    MAXCLS32)
79 
80 #define mk1(p, x)				\
81     (p) = (u_int8_t)(x)
82 
83 #define mk2(p, x)				\
84     (p)[0] = (u_int8_t)(x),			\
85     (p)[1] = (u_int8_t)((x) >> 010)
86 
87 #define mk4(p, x)				\
88     (p)[0] = (u_int8_t)(x),			\
89     (p)[1] = (u_int8_t)((x) >> 010),		\
90     (p)[2] = (u_int8_t)((x) >> 020),		\
91     (p)[3] = (u_int8_t)((x) >> 030)
92 
93 #define argto1(arg, lo, msg)  argtou(arg, lo, 0xff, msg)
94 #define argto2(arg, lo, msg)  argtou(arg, lo, 0xffff, msg)
95 #define argto4(arg, lo, msg)  argtou(arg, lo, 0xffffffff, msg)
96 #define argtox(arg, lo, msg)  argtou(arg, lo, UINT_MAX, msg)
97 
98 struct bs {
99     u_int8_t jmp[3];		/* bootstrap entry point */
100     u_int8_t oem[8];		/* OEM name and version */
101 };
102 
103 struct bsbpb {
104     u_int8_t bps[2];		/* bytes per sector */
105     u_int8_t spc;		/* sectors per cluster */
106     u_int8_t res[2];		/* reserved sectors */
107     u_int8_t nft;		/* number of FATs */
108     u_int8_t rde[2];		/* root directory entries */
109     u_int8_t sec[2];		/* total sectors */
110     u_int8_t mid;		/* media descriptor */
111     u_int8_t spf[2];		/* sectors per FAT */
112     u_int8_t spt[2];		/* sectors per track */
113     u_int8_t hds[2];		/* drive heads */
114     u_int8_t hid[4];		/* hidden sectors */
115     u_int8_t bsec[4];		/* big total sectors */
116 };
117 
118 struct bsxbpb {
119     u_int8_t bspf[4];		/* big sectors per FAT */
120     u_int8_t xflg[2];		/* FAT control flags */
121     u_int8_t vers[2];		/* file system version */
122     u_int8_t rdcl[4];		/* root directory start cluster */
123     u_int8_t infs[2];		/* file system info sector */
124     u_int8_t bkbs[2];		/* backup boot sector */
125     u_int8_t rsvd[12];		/* reserved */
126 };
127 
128 struct bsx {
129     u_int8_t drv;		/* drive number */
130     u_int8_t rsvd;		/* reserved */
131     u_int8_t sig;		/* extended boot signature */
132     u_int8_t volid[4];		/* volume ID number */
133     u_int8_t label[11]; 	/* volume label */
134     u_int8_t type[8];		/* file system type */
135 };
136 
137 struct de {
138     u_int8_t namext[11];	/* name and extension */
139     u_int8_t attr;		/* attributes */
140     u_int8_t rsvd[10];		/* reserved */
141     u_int8_t time[2];		/* creation time */
142     u_int8_t date[2];		/* creation date */
143     u_int8_t clus[2];		/* starting cluster */
144     u_int8_t size[4];		/* size */
145 };
146 
147 struct bpb {
148     u_int bps;			/* bytes per sector */
149     u_int spc;			/* sectors per cluster */
150     u_int res;			/* reserved sectors */
151     u_int nft;			/* number of FATs */
152     u_int rde;			/* root directory entries */
153     u_int sec;			/* total sectors */
154     u_int mid;			/* media descriptor */
155     u_int spf;			/* sectors per FAT */
156     u_int spt;			/* sectors per track */
157     u_int hds;			/* drive heads */
158     u_int hid;			/* hidden sectors */
159     u_int bsec; 		/* big total sectors */
160     u_int bspf; 		/* big sectors per FAT */
161     u_int rdcl; 		/* root directory start cluster */
162     u_int infs; 		/* file system info sector */
163     u_int bkbs; 		/* backup boot sector */
164 };
165 
166 #define BPBGAP 0, 0, 0, 0, 0, 0
167 
168 static struct {
169     const char *name;
170     struct bpb bpb;
171 } const stdfmt[] = {
172     {"160",  {512, 1, 1, 2,  64,  320, 0xfe, 1,  8, 1, BPBGAP}},
173     {"180",  {512, 1, 1, 2,  64,  360, 0xfc, 2,  9, 1, BPBGAP}},
174     {"320",  {512, 2, 1, 2, 112,  640, 0xff, 1,  8, 2, BPBGAP}},
175     {"360",  {512, 2, 1, 2, 112,  720, 0xfd, 2,  9, 2, BPBGAP}},
176     {"640",  {512, 2, 1, 2, 112, 1280, 0xfb, 2,  8, 2, BPBGAP}},
177     {"720",  {512, 2, 1, 2, 112, 1440, 0xf9, 3,  9, 2, BPBGAP}},
178     {"1200", {512, 1, 1, 2, 224, 2400, 0xf9, 7, 15, 2, BPBGAP}},
179     {"1232", {1024,1, 1, 2, 192, 1232, 0xfe, 2,  8, 2, BPBGAP}},
180     {"1440", {512, 1, 1, 2, 224, 2880, 0xf0, 9, 18, 2, BPBGAP}},
181     {"2880", {512, 2, 1, 2, 240, 5760, 0xf0, 9, 36, 2, BPBGAP}}
182 };
183 
184 static const u_int8_t bootcode[] = {
185     0xfa,			/* cli		    */
186     0x31, 0xc0, 		/* xor	   ax,ax    */
187     0x8e, 0xd0, 		/* mov	   ss,ax    */
188     0xbc, 0x00, 0x7c,		/* mov	   sp,7c00h */
189     0xfb,			/* sti		    */
190     0x8e, 0xd8, 		/* mov	   ds,ax    */
191     0xe8, 0x00, 0x00,		/* call    $ + 3    */
192     0x5e,			/* pop	   si	    */
193     0x83, 0xc6, 0x19,		/* add	   si,+19h  */
194     0xbb, 0x07, 0x00,		/* mov	   bx,0007h */
195     0xfc,			/* cld		    */
196     0xac,			/* lodsb	    */
197     0x84, 0xc0, 		/* test    al,al    */
198     0x74, 0x06, 		/* jz	   $ + 8    */
199     0xb4, 0x0e, 		/* mov	   ah,0eh   */
200     0xcd, 0x10, 		/* int	   10h	    */
201     0xeb, 0xf5, 		/* jmp	   $ - 9    */
202     0x30, 0xe4, 		/* xor	   ah,ah    */
203     0xcd, 0x16, 		/* int	   16h	    */
204     0xcd, 0x19, 		/* int	   19h	    */
205     0x0d, 0x0a,
206     'N', 'o', 'n', '-', 's', 'y', 's', 't',
207     'e', 'm', ' ', 'd', 'i', 's', 'k',
208     0x0d, 0x0a,
209     'P', 'r', 'e', 's', 's', ' ', 'a', 'n',
210     'y', ' ', 'k', 'e', 'y', ' ', 't', 'o',
211     ' ', 'r', 'e', 'b', 'o', 'o', 't',
212     0x0d, 0x0a,
213     0
214 };
215 
216 static void check_mounted(const char *, mode_t);
217 static void getstdfmt(const char *, struct bpb *);
218 static void getdiskinfo(int, const char *, const char *, int,
219 			struct bpb *);
220 static void print_bpb(struct bpb *);
221 static u_int ckgeom(const char *, u_int, const char *);
222 static u_int argtou(const char *, u_int, u_int, const char *);
223 static off_t argtooff(const char *, const char *);
224 static int oklabel(const char *);
225 static void mklabel(u_int8_t *, const char *);
226 static void setstr(u_int8_t *, const char *, size_t);
227 static void usage(void);
228 
229 /*
230  * Construct a FAT12, FAT16, or FAT32 file system.
231  */
232 int
233 main(int argc, char *argv[])
234 {
235     static const char opts[] = "@:NB:C:F:I:L:O:S:a:b:c:e:f:h:i:k:m:n:o:r:s:u:";
236     const char *opt_B = NULL, *opt_L = NULL, *opt_O = NULL, *opt_f = NULL;
237     u_int opt_F = 0, opt_I = 0, opt_S = 0, opt_a = 0, opt_b = 0, opt_c = 0;
238     u_int opt_e = 0, opt_h = 0, opt_i = 0, opt_k = 0, opt_m = 0, opt_n = 0;
239     u_int opt_o = 0, opt_r = 0, opt_s = 0, opt_u = 0;
240     int opt_N = 0;
241     int Iflag = 0, mflag = 0, oflag = 0;
242     char buf[MAXPATHLEN];
243     struct stat sb;
244     struct timeval tv;
245     struct bpb bpb;
246     struct tm *tm;
247     struct bs *bs;
248     struct bsbpb *bsbpb;
249     struct bsxbpb *bsxbpb;
250     struct bsx *bsx;
251     struct de *de;
252     u_int8_t *img;
253     const char *fname, *dtype, *bname;
254     ssize_t n;
255     time_t now;
256     u_int fat, bss, rds, cls, dir, lsn, x, x1, x2;
257     int ch, fd, fd1;
258     off_t opt_create = 0, opt_ofs = 0;
259 
260     while ((ch = getopt(argc, argv, opts)) != -1)
261 	switch (ch) {
262 	case '@':
263 	    opt_ofs = argtooff(optarg, "offset");
264 	    break;
265 	case 'N':
266 	    opt_N = 1;
267 	    break;
268 	case 'B':
269 	    opt_B = optarg;
270 	    break;
271 	case 'C':
272 	    opt_create = argtooff(optarg, "create size");
273 	    break;
274 	case 'F':
275 	    if (strcmp(optarg, "12") &&
276 		strcmp(optarg, "16") &&
277 		strcmp(optarg, "32"))
278 		errx(1, "%s: bad FAT type", optarg);
279 	    opt_F = atoi(optarg);
280 	    break;
281 	case 'I':
282 	    opt_I = argto4(optarg, 0, "volume ID");
283 	    Iflag = 1;
284 	    break;
285 	case 'L':
286 	    if (!oklabel(optarg))
287 		errx(1, "%s: bad volume label", optarg);
288 	    opt_L = optarg;
289 	    break;
290 	case 'O':
291 	    if (strlen(optarg) > 8)
292 		errx(1, "%s: bad OEM string", optarg);
293 	    opt_O = optarg;
294 	    break;
295 	case 'S':
296 	    opt_S = argto2(optarg, 1, "bytes/sector");
297 	    break;
298 	case 'a':
299 	    opt_a = argto4(optarg, 1, "sectors/FAT");
300 	    break;
301 	case 'b':
302 	    opt_b = argtox(optarg, 1, "block size");
303 	    opt_c = 0;
304 	    break;
305 	case 'c':
306 	    opt_c = argto1(optarg, 1, "sectors/cluster");
307 	    opt_b = 0;
308 	    break;
309 	case 'e':
310 	    opt_e = argto2(optarg, 1, "directory entries");
311 	    break;
312 	case 'f':
313 	    opt_f = optarg;
314 	    break;
315 	case 'h':
316 	    opt_h = argto2(optarg, 1, "drive heads");
317 	    break;
318 	case 'i':
319 	    opt_i = argto2(optarg, 1, "info sector");
320 	    break;
321 	case 'k':
322 	    opt_k = argto2(optarg, 1, "backup sector");
323 	    break;
324 	case 'm':
325 	    opt_m = argto1(optarg, 0, "media descriptor");
326 	    mflag = 1;
327 	    break;
328 	case 'n':
329 	    opt_n = argto1(optarg, 1, "number of FATs");
330 	    break;
331 	case 'o':
332 	    opt_o = argto4(optarg, 0, "hidden sectors");
333 	    oflag = 1;
334 	    break;
335 	case 'r':
336 	    opt_r = argto2(optarg, 1, "reserved sectors");
337 	    break;
338 	case 's':
339 	    opt_s = argto4(optarg, 1, "file system size");
340 	    break;
341 	case 'u':
342 	    opt_u = argto2(optarg, 1, "sectors/track");
343 	    break;
344 	default:
345 	    usage();
346 	}
347     argc -= optind;
348     argv += optind;
349     if (argc < 1 || argc > 2)
350 	usage();
351     fname = *argv++;
352     if (!opt_create && !strchr(fname, '/')) {
353 	snprintf(buf, sizeof(buf), "%s%s", _PATH_DEV, fname);
354 	if (!(fname = strdup(buf)))
355 	    err(1, NULL);
356     }
357     dtype = *argv;
358     if (opt_create) {
359 	if (opt_N)
360 	    errx(1, "create (-C) is incompatible with -N");
361 	fd = open(fname, O_RDWR | O_CREAT | O_TRUNC, 0644);
362 	if (fd == -1)
363 	    errx(1, "failed to create %s", fname);
364 	if (ftruncate(fd, opt_create))
365 	    errx(1, "failed to initialize %jd bytes", (intmax_t)opt_create);
366     } else if ((fd = open(fname, opt_N ? O_RDONLY : O_RDWR)) == -1)
367 	err(1, "%s", fname);
368     if (fstat(fd, &sb))
369 	err(1, "%s", fname);
370     if (opt_create) {
371 	if (!S_ISREG(sb.st_mode))
372 	    warnx("warning, %s is not a regular file", fname);
373     } else {
374 	if (!S_ISCHR(sb.st_mode))
375 	    warnx("warning, %s is not a character device", fname);
376     }
377     if (!opt_N)
378 	check_mounted(fname, sb.st_mode);
379     if (opt_ofs && opt_ofs != lseek(fd, opt_ofs, SEEK_SET))
380 	errx(1, "cannot seek to %jd", (intmax_t)opt_ofs);
381     memset(&bpb, 0, sizeof(bpb));
382     if (opt_f) {
383 	getstdfmt(opt_f, &bpb);
384 	bpb.bsec = bpb.sec;
385 	bpb.sec = 0;
386 	bpb.bspf = bpb.spf;
387 	bpb.spf = 0;
388     }
389     if (opt_h)
390 	bpb.hds = opt_h;
391     if (opt_u)
392 	bpb.spt = opt_u;
393     if (opt_S)
394 	bpb.bps = opt_S;
395     if (opt_s)
396 	bpb.bsec = opt_s;
397     if (oflag)
398 	bpb.hid = opt_o;
399     if (!(opt_f || (opt_h && opt_u && opt_S && opt_s && oflag))) {
400 	off_t delta;
401 	getdiskinfo(fd, fname, dtype, oflag, &bpb);
402 	bpb.bsec -= (opt_ofs / bpb.bps);
403 	delta = bpb.bsec % bpb.spt;
404 	if (delta != 0) {
405 	    warnx("trim %d sectors to adjust to a multiple of %d",
406 		(int)delta, bpb.spt);
407 	    bpb.bsec -= delta;
408 	}
409 	if (bpb.spc == 0) {	/* set defaults */
410 	    if (bpb.bsec <= 6000)	/* about 3MB -> 512 bytes */
411 		bpb.spc = 1;
412 	    else if (bpb.bsec <= (1<<17)) /* 64M -> 4k */
413 		bpb.spc = 8;
414 	    else if (bpb.bsec <= (1<<19)) /* 256M -> 8k */
415 		bpb.spc = 16;
416 	    else if (bpb.bsec <= (1<<21)) /* 1G -> 16k */
417 		bpb.spc = 32;
418 	    else
419 		bpb.spc = 64;		/* otherwise 32k */
420 	}
421     }
422     if (!powerof2(bpb.bps))
423 	errx(1, "bytes/sector (%u) is not a power of 2", bpb.bps);
424     if (bpb.bps < MINBPS)
425 	errx(1, "bytes/sector (%u) is too small; minimum is %u",
426 	     bpb.bps, MINBPS);
427     if (!(fat = opt_F)) {
428 	if (opt_f)
429 	    fat = 12;
430 	else if (!opt_e && (opt_i || opt_k))
431 	    fat = 32;
432     }
433     if ((fat == 32 && opt_e) || (fat != 32 && (opt_i || opt_k)))
434 	errx(1, "-%c is not a legal FAT%s option",
435 	     fat == 32 ? 'e' : opt_i ? 'i' : 'k',
436 	     fat == 32 ? "32" : "12/16");
437     if (opt_f && fat == 32)
438 	bpb.rde = 0;
439     if (opt_b) {
440 	if (!powerof2(opt_b))
441 	    errx(1, "block size (%u) is not a power of 2", opt_b);
442 	if (opt_b < bpb.bps)
443 	    errx(1, "block size (%u) is too small; minimum is %u",
444 		 opt_b, bpb.bps);
445 	if (opt_b > bpb.bps * MAXSPC)
446 	    errx(1, "block size (%u) is too large; maximum is %u",
447 		 opt_b, bpb.bps * MAXSPC);
448 	bpb.spc = opt_b / bpb.bps;
449     }
450     if (opt_c) {
451 	if (!powerof2(opt_c))
452 	    errx(1, "sectors/cluster (%u) is not a power of 2", opt_c);
453 	bpb.spc = opt_c;
454     }
455     if (opt_r)
456 	bpb.res = opt_r;
457     if (opt_n) {
458 	if (opt_n > MAXNFT)
459 	    errx(1, "number of FATs (%u) is too large; maximum is %u",
460 		 opt_n, MAXNFT);
461 	bpb.nft = opt_n;
462     }
463     if (opt_e)
464 	bpb.rde = opt_e;
465     if (mflag) {
466 	if (opt_m < 0xf0)
467 	    errx(1, "illegal media descriptor (%#x)", opt_m);
468 	bpb.mid = opt_m;
469     }
470     if (opt_a)
471 	bpb.bspf = opt_a;
472     if (opt_i)
473 	bpb.infs = opt_i;
474     if (opt_k)
475 	bpb.bkbs = opt_k;
476     bss = 1;
477     bname = NULL;
478     fd1 = -1;
479     if (opt_B) {
480 	bname = opt_B;
481 	if (!strchr(bname, '/')) {
482 	    snprintf(buf, sizeof(buf), "/boot/%s", bname);
483 	    if (!(bname = strdup(buf)))
484 		err(1, NULL);
485 	}
486 	if ((fd1 = open(bname, O_RDONLY)) == -1 || fstat(fd1, &sb))
487 	    err(1, "%s", bname);
488 	if (!S_ISREG(sb.st_mode) || sb.st_size % bpb.bps ||
489 	    sb.st_size < bpb.bps || sb.st_size > bpb.bps * MAXU16)
490 	    errx(1, "%s: inappropriate file type or format", bname);
491 	bss = sb.st_size / bpb.bps;
492     }
493     if (!bpb.nft)
494 	bpb.nft = 2;
495     if (!fat) {
496 	if (bpb.bsec < (bpb.res ? bpb.res : bss) +
497 	    howmany((RESFTE + (bpb.spc ? MINCLS16 : MAXCLS12 + 1)) *
498 		    ((bpb.spc ? 16 : 12) / BPN), bpb.bps * NPB) *
499 	    bpb.nft +
500 	    howmany(bpb.rde ? bpb.rde : DEFRDE,
501 		    bpb.bps / sizeof(struct de)) +
502 	    (bpb.spc ? MINCLS16 : MAXCLS12 + 1) *
503 	    (bpb.spc ? bpb.spc : howmany(DEFBLK, bpb.bps)))
504 	    fat = 12;
505 	else if (bpb.rde || bpb.bsec <
506 		 (bpb.res ? bpb.res : bss) +
507 		 howmany((RESFTE + MAXCLS16) * 2, bpb.bps) * bpb.nft +
508 		 howmany(DEFRDE, bpb.bps / sizeof(struct de)) +
509 		 (MAXCLS16 + 1) *
510 		 (bpb.spc ? bpb.spc : howmany(8192, bpb.bps)))
511 	    fat = 16;
512 	else
513 	    fat = 32;
514     }
515     x = bss;
516     if (fat == 32) {
517 	if (!bpb.infs) {
518 	    if (x == MAXU16 || x == bpb.bkbs)
519 		errx(1, "no room for info sector");
520 	    bpb.infs = x;
521 	}
522 	if (bpb.infs != MAXU16 && x <= bpb.infs)
523 	    x = bpb.infs + 1;
524 	if (!bpb.bkbs) {
525 	    if (x == MAXU16)
526 		errx(1, "no room for backup sector");
527 	    bpb.bkbs = x;
528 	} else if (bpb.bkbs != MAXU16 && bpb.bkbs == bpb.infs)
529 	    errx(1, "backup sector would overwrite info sector");
530 	if (bpb.bkbs != MAXU16 && x <= bpb.bkbs)
531 	    x = bpb.bkbs + 1;
532     }
533     if (!bpb.res)
534 	bpb.res = fat == 32 ? MAX(x, MAX(16384 / bpb.bps, 4)) : x;
535     else if (bpb.res < x)
536 	errx(1, "too few reserved sectors");
537     if (fat != 32 && !bpb.rde)
538 	bpb.rde = DEFRDE;
539     rds = howmany(bpb.rde, bpb.bps / sizeof(struct de));
540     if (!bpb.spc)
541 	for (bpb.spc = howmany(fat == 16 ? DEFBLK16 : DEFBLK, bpb.bps);
542 	     bpb.spc < MAXSPC &&
543 	     bpb.res +
544 	     howmany((RESFTE + maxcls(fat)) * (fat / BPN),
545 		     bpb.bps * NPB) * bpb.nft +
546 	     rds +
547 	     (u_int64_t)(maxcls(fat) + 1) * bpb.spc <= bpb.bsec;
548 	     bpb.spc <<= 1);
549     if (fat != 32 && bpb.bspf > MAXU16)
550 	errx(1, "too many sectors/FAT for FAT12/16");
551     x1 = bpb.res + rds;
552     x = bpb.bspf ? bpb.bspf : 1;
553     if (x1 + (u_int64_t)x * bpb.nft > bpb.bsec)
554 	errx(1, "meta data exceeds file system size");
555     x1 += x * bpb.nft;
556     x = (u_int64_t)(bpb.bsec - x1) * bpb.bps * NPB /
557 	(bpb.spc * bpb.bps * NPB + fat / BPN * bpb.nft);
558     x2 = howmany((RESFTE + MIN(x, maxcls(fat))) * (fat / BPN),
559 		 bpb.bps * NPB);
560     if (!bpb.bspf) {
561 	bpb.bspf = x2;
562 	x1 += (bpb.bspf - 1) * bpb.nft;
563     }
564     cls = (bpb.bsec - x1) / bpb.spc;
565     x = (u_int64_t)bpb.bspf * bpb.bps * NPB / (fat / BPN) - RESFTE;
566     if (cls > x)
567 	cls = x;
568     if (bpb.bspf < x2)
569 	warnx("warning: sectors/FAT limits file system to %u clusters",
570 	      cls);
571     if (cls < mincls(fat))
572 	errx(1, "%u clusters too few clusters for FAT%u, need %u", cls, fat,
573 	    mincls(fat));
574     if (cls > maxcls(fat)) {
575 	cls = maxcls(fat);
576 	bpb.bsec = x1 + (cls + 1) * bpb.spc - 1;
577 	warnx("warning: FAT type limits file system to %u sectors",
578 	      bpb.bsec);
579     }
580     printf("%s: %u sector%s in %u FAT%u cluster%s "
581 	   "(%u bytes/cluster)\n", fname, cls * bpb.spc,
582 	   cls * bpb.spc == 1 ? "" : "s", cls, fat,
583 	   cls == 1 ? "" : "s", bpb.bps * bpb.spc);
584     if (!bpb.mid)
585 	bpb.mid = !bpb.hid ? 0xf0 : 0xf8;
586     if (fat == 32)
587 	bpb.rdcl = RESFTE;
588     if (bpb.hid + bpb.bsec <= MAXU16) {
589 	bpb.sec = bpb.bsec;
590 	bpb.bsec = 0;
591     }
592     if (fat != 32) {
593 	bpb.spf = bpb.bspf;
594 	bpb.bspf = 0;
595     }
596     print_bpb(&bpb);
597     if (!opt_N) {
598 	gettimeofday(&tv, NULL);
599 	now = tv.tv_sec;
600 	tm = localtime(&now);
601 	if (!(img = malloc(bpb.bps)))
602 	    err(1, NULL);
603 	dir = bpb.res + (bpb.spf ? bpb.spf : bpb.bspf) * bpb.nft;
604 	for (lsn = 0; lsn < dir + (fat == 32 ? bpb.spc : rds); lsn++) {
605 	    x = lsn;
606 	    if (opt_B &&
607 		fat == 32 && bpb.bkbs != MAXU16 &&
608 		bss <= bpb.bkbs && x >= bpb.bkbs) {
609 		x -= bpb.bkbs;
610 		if (!x && lseek(fd1, opt_ofs, SEEK_SET))
611 		    err(1, "%s", bname);
612 	    }
613 	    if (opt_B && x < bss) {
614 		if ((n = read(fd1, img, bpb.bps)) == -1)
615 		    err(1, "%s", bname);
616 		if ((unsigned)n != bpb.bps)
617 		    errx(1, "%s: can't read sector %u", bname, x);
618 	    } else
619 		memset(img, 0, bpb.bps);
620 	    if (!lsn ||
621 	      (fat == 32 && bpb.bkbs != MAXU16 && lsn == bpb.bkbs)) {
622 		x1 = sizeof(struct bs);
623 		bsbpb = (struct bsbpb *)(img + x1);
624 		mk2(bsbpb->bps, bpb.bps);
625 		mk1(bsbpb->spc, bpb.spc);
626 		mk2(bsbpb->res, bpb.res);
627 		mk1(bsbpb->nft, bpb.nft);
628 		mk2(bsbpb->rde, bpb.rde);
629 		mk2(bsbpb->sec, bpb.sec);
630 		mk1(bsbpb->mid, bpb.mid);
631 		mk2(bsbpb->spf, bpb.spf);
632 		mk2(bsbpb->spt, bpb.spt);
633 		mk2(bsbpb->hds, bpb.hds);
634 		mk4(bsbpb->hid, bpb.hid);
635 		mk4(bsbpb->bsec, bpb.bsec);
636 		x1 += sizeof(struct bsbpb);
637 		if (fat == 32) {
638 		    bsxbpb = (struct bsxbpb *)(img + x1);
639 		    mk4(bsxbpb->bspf, bpb.bspf);
640 		    mk2(bsxbpb->xflg, 0);
641 		    mk2(bsxbpb->vers, 0);
642 		    mk4(bsxbpb->rdcl, bpb.rdcl);
643 		    mk2(bsxbpb->infs, bpb.infs);
644 		    mk2(bsxbpb->bkbs, bpb.bkbs);
645 		    x1 += sizeof(struct bsxbpb);
646 		}
647 		bsx = (struct bsx *)(img + x1);
648 		mk1(bsx->sig, 0x29);
649 		if (Iflag)
650 		    x = opt_I;
651 		else
652 		    x = (((u_int)(1 + tm->tm_mon) << 8 |
653 			  (u_int)tm->tm_mday) +
654 			 ((u_int)tm->tm_sec << 8 |
655 			  (u_int)(tv.tv_usec / 10))) << 16 |
656 			((u_int)(1900 + tm->tm_year) +
657 			 ((u_int)tm->tm_hour << 8 |
658 			  (u_int)tm->tm_min));
659 		mk4(bsx->volid, x);
660 		mklabel(bsx->label, opt_L ? opt_L : "NO NAME");
661 		sprintf(buf, "FAT%u", fat);
662 		setstr(bsx->type, buf, sizeof(bsx->type));
663 		if (!opt_B) {
664 		    x1 += sizeof(struct bsx);
665 		    bs = (struct bs *)img;
666 		    mk1(bs->jmp[0], 0xeb);
667 		    mk1(bs->jmp[1], x1 - 2);
668 		    mk1(bs->jmp[2], 0x90);
669 		    setstr(bs->oem, opt_O ? opt_O : "BSD  4.4",
670 			   sizeof(bs->oem));
671 		    memcpy(img + x1, bootcode, sizeof(bootcode));
672 		    mk2(img + MINBPS - 2, DOSMAGIC);
673 		}
674 	    } else if (fat == 32 && bpb.infs != MAXU16 &&
675 		       (lsn == bpb.infs ||
676 			(bpb.bkbs != MAXU16 &&
677 			 lsn == bpb.bkbs + bpb.infs))) {
678 		mk4(img, 0x41615252);
679 		mk4(img + MINBPS - 28, 0x61417272);
680 		mk4(img + MINBPS - 24, 0xffffffff);
681 		mk4(img + MINBPS - 20, bpb.rdcl);
682 		mk2(img + MINBPS - 2, DOSMAGIC);
683 	    } else if (lsn >= bpb.res && lsn < dir &&
684 		       !((lsn - bpb.res) %
685 			 (bpb.spf ? bpb.spf : bpb.bspf))) {
686 		mk1(img[0], bpb.mid);
687 		for (x = 1; x < fat * (fat == 32 ? 3 : 2) / 8; x++)
688 		    mk1(img[x], fat == 32 && x % 4 == 3 ? 0x0f : 0xff);
689 	    } else if (lsn == dir && opt_L) {
690 		de = (struct de *)img;
691 		mklabel(de->namext, opt_L);
692 		mk1(de->attr, 050);
693 		x = (u_int)tm->tm_hour << 11 |
694 		    (u_int)tm->tm_min << 5 |
695 		    (u_int)tm->tm_sec >> 1;
696 		mk2(de->time, x);
697 		x = (u_int)(tm->tm_year - 80) << 9 |
698 		    (u_int)(tm->tm_mon + 1) << 5 |
699 		    (u_int)tm->tm_mday;
700 		mk2(de->date, x);
701 	    }
702 	    if ((n = write(fd, img, bpb.bps)) == -1)
703 		err(1, "%s", fname);
704 	    if ((unsigned)n != bpb.bps)
705 		errx(1, "%s: can't write sector %u", fname, lsn);
706 	}
707     }
708     return 0;
709 }
710 
711 /*
712  * Exit with error if file system is mounted.
713  */
714 static void
715 check_mounted(const char *fname, mode_t mode)
716 {
717     struct statfs *mp;
718     const char *s1, *s2;
719     size_t len;
720     int n, r;
721 
722     if (!(n = getmntinfo(&mp, MNT_NOWAIT)))
723 	err(1, "getmntinfo");
724     len = strlen(_PATH_DEV);
725     s1 = fname;
726     if (!strncmp(s1, _PATH_DEV, len))
727 	s1 += len;
728     r = S_ISCHR(mode) && s1 != fname && *s1 == 'r';
729     for (; n--; mp++) {
730 	s2 = mp->f_mntfromname;
731 	if (!strncmp(s2, _PATH_DEV, len))
732 	    s2 += len;
733 	if ((r && s2 != mp->f_mntfromname && !strcmp(s1 + 1, s2)) ||
734 	    !strcmp(s1, s2))
735 	    errx(1, "%s is mounted on %s", fname, mp->f_mntonname);
736     }
737 }
738 
739 /*
740  * Get a standard format.
741  */
742 static void
743 getstdfmt(const char *fmt, struct bpb *bpb)
744 {
745     u_int x, i;
746 
747     x = sizeof(stdfmt) / sizeof(stdfmt[0]);
748     for (i = 0; i < x && strcmp(fmt, stdfmt[i].name); i++);
749     if (i == x)
750 	errx(1, "%s: unknown standard format", fmt);
751     *bpb = stdfmt[i].bpb;
752 }
753 
754 /*
755  * Get disk slice, partition, and geometry information.
756  */
757 static void
758 getdiskinfo(int fd, const char *fname, const char *dtype, __unused int oflag,
759 	    struct bpb *bpb)
760 {
761     struct disklabel *lp, dlp;
762     struct fd_type type;
763     off_t ms, hs = 0;
764 
765     lp = NULL;
766 
767     /* If the user specified a disk type, try to use that */
768     if (dtype != NULL) {
769 	lp = getdiskbyname(dtype);
770     }
771 
772     /* Maybe it's a floppy drive */
773     if (lp == NULL) {
774 	if (ioctl(fd, DIOCGMEDIASIZE, &ms) == -1) {
775 	    struct stat st;
776 
777 	    if (fstat(fd, &st))
778 		err(1, "Cannot get disk size");
779 	    /* create a fake geometry for a file image */
780 	    ms = st.st_size;
781 	    dlp.d_secsize = 512;
782 	    dlp.d_nsectors = 63;
783 	    dlp.d_ntracks = 255;
784 	    dlp.d_secperunit = ms / dlp.d_secsize;
785 	    lp = &dlp;
786 	} else if (ioctl(fd, FD_GTYPE, &type) != -1) {
787 	    dlp.d_secsize = 128 << type.secsize;
788 	    dlp.d_nsectors = type.sectrac;
789 	    dlp.d_ntracks = type.heads;
790 	    dlp.d_secperunit = ms / dlp.d_secsize;
791 	    lp = &dlp;
792 	}
793     }
794 
795     /* Maybe it's a fixed drive */
796     if (lp == NULL) {
797 	if (ioctl(fd, DIOCGDINFO, &dlp) == -1) {
798 	    if (bpb->bps == 0 && ioctl(fd, DIOCGSECTORSIZE, &dlp.d_secsize) == -1)
799 		errx(1, "Cannot get sector size, %s", strerror(errno));
800 
801 	    /* XXX Should we use bpb->bps if it's set? */
802 	    dlp.d_secperunit = ms / dlp.d_secsize;
803 
804 	    if (bpb->spt == 0 && ioctl(fd, DIOCGFWSECTORS, &dlp.d_nsectors) == -1) {
805 		warnx("Cannot get number of sectors per track, %s", strerror(errno));
806 		dlp.d_nsectors = 63;
807 	    }
808 	    if (bpb->hds == 0 && ioctl(fd, DIOCGFWHEADS, &dlp.d_ntracks) == -1) {
809 		warnx("Cannot get number of heads, %s", strerror(errno));
810 		if (dlp.d_secperunit <= 63*1*1024)
811 		    dlp.d_ntracks = 1;
812 		else if (dlp.d_secperunit <= 63*16*1024)
813 		    dlp.d_ntracks = 16;
814 		else
815 		    dlp.d_ntracks = 255;
816 	    }
817 	}
818 
819 	hs = (ms / dlp.d_secsize) - dlp.d_secperunit;
820 	lp = &dlp;
821     }
822 
823     if (bpb->bps == 0)
824 	bpb->bps = ckgeom(fname, lp->d_secsize, "bytes/sector");
825     if (bpb->spt == 0)
826 	bpb->spt = ckgeom(fname, lp->d_nsectors, "sectors/track");
827     if (bpb->hds == 0)
828 	bpb->hds = ckgeom(fname, lp->d_ntracks, "drive heads");
829     if (bpb->bsec == 0)
830 	bpb->bsec = lp->d_secperunit;
831     if (bpb->hid == 0)
832 	bpb->hid = hs;
833 }
834 
835 /*
836  * Print out BPB values.
837  */
838 static void
839 print_bpb(struct bpb *bpb)
840 {
841     printf("bps=%u spc=%u res=%u nft=%u", bpb->bps, bpb->spc, bpb->res,
842 	   bpb->nft);
843     if (bpb->rde)
844 	printf(" rde=%u", bpb->rde);
845     if (bpb->sec)
846 	printf(" sec=%u", bpb->sec);
847     printf(" mid=%#x", bpb->mid);
848     if (bpb->spf)
849 	printf(" spf=%u", bpb->spf);
850     printf(" spt=%u hds=%u hid=%u", bpb->spt, bpb->hds, bpb->hid);
851     if (bpb->bsec)
852 	printf(" bsec=%u", bpb->bsec);
853     if (!bpb->spf) {
854 	printf(" bspf=%u rdcl=%u", bpb->bspf, bpb->rdcl);
855 	printf(" infs=");
856 	printf(bpb->infs == MAXU16 ? "%#x" : "%u", bpb->infs);
857 	printf(" bkbs=");
858 	printf(bpb->bkbs == MAXU16 ? "%#x" : "%u", bpb->bkbs);
859     }
860     printf("\n");
861 }
862 
863 /*
864  * Check a disk geometry value.
865  */
866 static u_int
867 ckgeom(const char *fname, u_int val, const char *msg)
868 {
869     if (!val)
870 	errx(1, "%s: no default %s", fname, msg);
871     if (val > MAXU16)
872 	errx(1, "%s: illegal %s %d", fname, msg, val);
873     return val;
874 }
875 
876 /*
877  * Convert and check a numeric option argument.
878  */
879 static u_int
880 argtou(const char *arg, u_int lo, u_int hi, const char *msg)
881 {
882     char *s;
883     u_long x;
884 
885     errno = 0;
886     x = strtoul(arg, &s, 0);
887     if (errno || !*arg || *s || x < lo || x > hi)
888 	errx(1, "%s: bad %s", arg, msg);
889     return x;
890 }
891 
892 /*
893  * Same for off_t, with optional skmgpP suffix
894  */
895 static off_t
896 argtooff(const char *arg, const char *msg)
897 {
898     char *s;
899     off_t x;
900 
901     x = strtoll(arg, &s, 0);
902     /* allow at most one extra char */
903     if (errno || x < 0 || (s[0] && s[1]) )
904 	errx(1, "%s: bad %s", arg, msg);
905     if (*s) {	/* the extra char is the multiplier */
906 	switch (*s) {
907 	default:
908 	    errx(1, "%s: bad %s", arg, msg);
909 	    /* notreached */
910 
911 	case 's':	/* sector */
912 	case 'S':
913 	    x <<= 9;	/* times 512 */
914 	    break;
915 
916 	case 'k':	/* kilobyte */
917 	case 'K':
918 	    x <<= 10;	/* times 1024 */
919 	    break;
920 
921 	case 'm':	/* megabyte */
922 	case 'M':
923 	    x <<= 20;	/* times 1024*1024 */
924 	    break;
925 
926 	case 'g':	/* gigabyte */
927 	case 'G':
928 	    x <<= 30;	/* times 1024*1024*1024 */
929 	    break;
930 
931 	case 'p':	/* partition start */
932 	case 'P':	/* partition start */
933 	case 'l':	/* partition length */
934 	case 'L':	/* partition length */
935 	    errx(1, "%s: not supported yet %s", arg, msg);
936 	    /* notreached */
937 	}
938     }
939     return x;
940 }
941 
942 /*
943  * Check a volume label.
944  */
945 static int
946 oklabel(const char *src)
947 {
948     int c, i;
949 
950     for (i = 0; i <= 11; i++) {
951 	c = (u_char)*src++;
952 	if (c < ' ' + !i || strchr("\"*+,./:;<=>?[\\]|", c))
953 	    break;
954     }
955     return i && !c;
956 }
957 
958 /*
959  * Make a volume label.
960  */
961 static void
962 mklabel(u_int8_t *dest, const char *src)
963 {
964     int c, i;
965 
966     for (i = 0; i < 11; i++) {
967 	c = *src ? toupper(*src++) : ' ';
968 	*dest++ = !i && c == '\xe5' ? 5 : c;
969     }
970 }
971 
972 /*
973  * Copy string, padding with spaces.
974  */
975 static void
976 setstr(u_int8_t *dest, const char *src, size_t len)
977 {
978     while (len--)
979 	*dest++ = *src ? *src++ : ' ';
980 }
981 
982 /*
983  * Print usage message.
984  */
985 static void
986 usage(void)
987 {
988 	fprintf(stderr,
989 	    "usage: newfs_msdos [ -options ] special [disktype]\n"
990 	    "where the options are:\n"
991 	    "\t-@ create file system at specified offset\n"
992 	    "\t-B get bootstrap from file\n"
993 	    "\t-C create image file with specified size\n"
994 	    "\t-F FAT type (12, 16, or 32)\n"
995 	    "\t-I volume ID\n"
996 	    "\t-L volume label\n"
997 	    "\t-N don't create file system: just print out parameters\n"
998 	    "\t-O OEM string\n"
999 	    "\t-S bytes/sector\n"
1000 	    "\t-a sectors/FAT\n"
1001 	    "\t-b block size\n"
1002 	    "\t-c sectors/cluster\n"
1003 	    "\t-e root directory entries\n"
1004 	    "\t-f standard format\n"
1005 	    "\t-h drive heads\n"
1006 	    "\t-i file system info sector\n"
1007 	    "\t-k backup boot sector\n"
1008 	    "\t-m media descriptor\n"
1009 	    "\t-n number of FATs\n"
1010 	    "\t-o hidden sectors\n"
1011 	    "\t-r reserved sectors\n"
1012 	    "\t-s file system size (sectors)\n"
1013 	    "\t-u sectors/track\n");
1014 	exit(1);
1015 }
1016