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: src/sbin/newfs_msdos/newfs_msdos.c,v 1.33 2009/04/11 14:56:29 ed Exp $";
31 #endif /* not lint */
32 
33 #include <sys/param.h>
34 
35 #ifndef ANDROID
36 #include <sys/fdcio.h>
37 #include <sys/disk.h>
38 #include <sys/disklabel.h>
39 #include <sys/mount.h>
40 #else
41 #include <stdarg.h>
42 #include <linux/fs.h>
43 #include <linux/hdreg.h>
44 #endif
45 
46 #include <sys/stat.h>
47 #include <sys/time.h>
48 
49 #include <ctype.h>
50 #include <err.h>
51 #include <errno.h>
52 #include <fcntl.h>
53 #include <inttypes.h>
54 #include <paths.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <string.h>
58 #include <time.h>
59 #include <unistd.h>
60 
61 #define MAXU16   0xffff     /* maximum unsigned 16-bit quantity */
62 #define BPN      4          /* bits per nibble */
63 #define NPB      2          /* nibbles per byte */
64 
65 #define DOSMAGIC  0xaa55    /* DOS magic number */
66 #define MINBPS    512       /* minimum bytes per sector */
67 #define MAXSPC    128       /* maximum sectors per cluster */
68 #define MAXNFT    16        /* maximum number of FATs */
69 #define DEFBLK    4096      /* default block size */
70 #define DEFBLK16  2048      /* default block size FAT16 */
71 #define DEFRDE    512       /* default root directory entries */
72 #define RESFTE    2         /* reserved FAT entries */
73 #define MINCLS12  1         /* minimum FAT12 clusters */
74 #define MINCLS16  0x1000    /* minimum FAT16 clusters */
75 #define MINCLS32  2         /* minimum FAT32 clusters */
76 #define MAXCLS12  0xfed     /* maximum FAT12 clusters */
77 #define MAXCLS16  0xfff5    /* maximum FAT16 clusters */
78 #define MAXCLS32  0xffffff5 /* maximum FAT32 clusters */
79 
80 #define mincls(fat)  ((fat) == 12 ? MINCLS12 :    \
81                       (fat) == 16 ? MINCLS16 :    \
82                                         MINCLS32)
83 
84 #define maxcls(fat)  ((fat) == 12 ? MAXCLS12 :    \
85                       (fat) == 16 ? MAXCLS16 :    \
86                                         MAXCLS32)
87 
88 #define mk1(p, x)                           \
89     (p) = (u_int8_t)(x)
90 
91 #define mk2(p, x)                           \
92     (p)[0] = (u_int8_t)(x),                 \
93     (p)[1] = (u_int8_t)((x) >> 010)
94 
95 #define mk4(p, x)                           \
96     (p)[0] = (u_int8_t)(x),                 \
97     (p)[1] = (u_int8_t)((x) >> 010),        \
98     (p)[2] = (u_int8_t)((x) >> 020),        \
99     (p)[3] = (u_int8_t)((x) >> 030)
100 
101 #define argto1(arg, lo, msg)  argtou(arg, lo, 0xff, msg)
102 #define argto2(arg, lo, msg)  argtou(arg, lo, 0xffff, msg)
103 #define argto4(arg, lo, msg)  argtou(arg, lo, 0xffffffff, msg)
104 #define argtox(arg, lo, msg)  argtou(arg, lo, UINT_MAX, msg)
105 
106 struct bs {
107     u_int8_t jmp[3];        /* bootstrap entry point */
108     u_int8_t oem[8];        /* OEM name and version */
109 };
110 
111 struct bsbpb {
112     u_int8_t bps[2];    /* bytes per sector */
113     u_int8_t spc;       /* sectors per cluster */
114     u_int8_t res[2];    /* reserved sectors */
115     u_int8_t nft;       /* number of FATs */
116     u_int8_t rde[2];    /* root directory entries */
117     u_int8_t sec[2];    /* total sectors */
118     u_int8_t mid;       /* media descriptor */
119     u_int8_t spf[2];    /* sectors per FAT */
120     u_int8_t spt[2];    /* sectors per track */
121     u_int8_t hds[2];    /* drive heads */
122     u_int8_t hid[4];    /* hidden sectors */
123     u_int8_t bsec[4];   /* big total sectors */
124 };
125 
126 struct bsxbpb {
127     u_int8_t bspf[4];       /* big sectors per FAT */
128     u_int8_t xflg[2];       /* FAT control flags */
129     u_int8_t vers[2];       /* file system version */
130     u_int8_t rdcl[4];       /* root directory start cluster */
131     u_int8_t infs[2];       /* file system info sector */
132     u_int8_t bkbs[2];       /* backup boot sector */
133     u_int8_t rsvd[12];      /* reserved */
134 };
135 
136 struct bsx {
137     u_int8_t drv;           /* drive number */
138     u_int8_t rsvd;          /* reserved */
139     u_int8_t sig;           /* extended boot signature */
140     u_int8_t volid[4];      /* volume ID number */
141     u_int8_t label[11];     /* volume label */
142     u_int8_t type[8];       /* file system type */
143 };
144 
145 struct de {
146     u_int8_t namext[11];    /* name and extension */
147     u_int8_t attr;          /* attributes */
148     u_int8_t rsvd[10];      /* reserved */
149     u_int8_t time[2];       /* creation time */
150     u_int8_t date[2];       /* creation date */
151     u_int8_t clus[2];       /* starting cluster */
152     u_int8_t size[4];       /* size */
153 };
154 
155 struct bpb {
156     u_int bps;          /* bytes per sector */
157     u_int spc;          /* sectors per cluster */
158     u_int res;          /* reserved sectors */
159     u_int nft;          /* number of FATs */
160     u_int rde;          /* root directory entries */
161     u_int sec;          /* total sectors */
162     u_int mid;          /* media descriptor */
163     u_int spf;          /* sectors per FAT */
164     u_int spt;          /* sectors per track */
165     u_int hds;          /* drive heads */
166     u_int hid;          /* hidden sectors */
167     u_int bsec;         /* big total sectors */
168     u_int bspf;         /* big sectors per FAT */
169     u_int rdcl;         /* root directory start cluster */
170     u_int infs;         /* file system info sector */
171     u_int bkbs;         /* backup boot sector */
172 };
173 
174 #define BPBGAP 0, 0, 0, 0, 0, 0
175 
176 static struct {
177     const char *name;
178     struct bpb bpb;
179 } const stdfmt[] = {
180     {"160",  {512, 1, 1, 2,  64,  320, 0xfe, 1,  8, 1, BPBGAP}},
181     {"180",  {512, 1, 1, 2,  64,  360, 0xfc, 2,  9, 1, BPBGAP}},
182     {"320",  {512, 2, 1, 2, 112,  640, 0xff, 1,  8, 2, BPBGAP}},
183     {"360",  {512, 2, 1, 2, 112,  720, 0xfd, 2,  9, 2, BPBGAP}},
184     {"640",  {512, 2, 1, 2, 112, 1280, 0xfb, 2,  8, 2, BPBGAP}},
185     {"720",  {512, 2, 1, 2, 112, 1440, 0xf9, 3,  9, 2, BPBGAP}},
186     {"1200", {512, 1, 1, 2, 224, 2400, 0xf9, 7, 15, 2, BPBGAP}},
187     {"1232", {1024,1, 1, 2, 192, 1232, 0xfe, 2,  8, 2, BPBGAP}},
188     {"1440", {512, 1, 1, 2, 224, 2880, 0xf0, 9, 18, 2, BPBGAP}},
189     {"2880", {512, 2, 1, 2, 240, 5760, 0xf0, 9, 36, 2, BPBGAP}}
190 };
191 
192 static const u_int8_t bootcode[] = {
193     0xfa,               /* cli             */
194     0x31, 0xc0,         /* xor    ax,ax    */
195     0x8e, 0xd0,         /* mov    ss,ax    */
196     0xbc, 0x00, 0x7c,   /* mov    sp,7c00h */
197     0xfb,               /* sti             */
198     0x8e, 0xd8,         /* mov    ds,ax    */
199     0xe8, 0x00, 0x00,   /* call   $ + 3    */
200     0x5e,               /* pop    si       */
201     0x83, 0xc6, 0x19,   /* add    si,+19h  */
202     0xbb, 0x07, 0x00,   /* mov    bx,0007h */
203     0xfc,               /* cld             */
204     0xac,               /* lodsb           */
205     0x84, 0xc0,         /* test   al,al    */
206     0x74, 0x06,         /* jz     $ + 8    */
207     0xb4, 0x0e,         /* mov    ah,0eh   */
208     0xcd, 0x10,         /* int    10h      */
209     0xeb, 0xf5,         /* jmp    $ - 9    */
210     0x30, 0xe4,         /* xor    ah,ah    */
211     0xcd, 0x16,         /* int    16h      */
212     0xcd, 0x19,         /* int    19h      */
213     0x0d, 0x0a,
214     'N', 'o', 'n', '-', 's', 'y', 's', 't',
215     'e', 'm', ' ', 'd', 'i', 's', 'k',
216     0x0d, 0x0a,
217     'P', 'r', 'e', 's', 's', ' ', 'a', 'n',
218     'y', ' ', 'k', 'e', 'y', ' ', 't', 'o',
219     ' ', 'r', 'e', 'b', 'o', 'o', 't',
220     0x0d, 0x0a,
221     0
222 };
223 
224 static void check_mounted(const char *, mode_t);
225 static void getstdfmt(const char *, struct bpb *);
226 static void getdiskinfo(int, const char *, const char *, int, struct bpb *);
227 static void print_bpb(struct bpb *);
228 static u_int ckgeom(const char *, u_int, const char *);
229 static u_int argtou(const char *, u_int, u_int, const char *);
230 static off_t argtooff(const char *, const char *);
231 static int oklabel(const char *);
232 static void mklabel(u_int8_t *, const char *);
233 static void setstr(u_int8_t *, const char *, size_t);
234 static void usage(void);
235 
236 /*
237  * Construct a FAT12, FAT16, or FAT32 file system.
238  */
newfs_msdos_main(int argc,char * argv[])239 int newfs_msdos_main(int argc, char *argv[])
240 {
241     static const char opts[] = "@:NAB:C:F:I:L:O:S:a:b:c:e:f:h:i:k:m:n:o:r:s:u:";
242     const char *opt_B = NULL, *opt_L = NULL, *opt_O = NULL, *opt_f = NULL;
243     u_int opt_F = 0, opt_I = 0, opt_S = 0, opt_a = 0, opt_b = 0, opt_c = 0;
244     u_int opt_e = 0, opt_h = 0, opt_i = 0, opt_k = 0, opt_m = 0, opt_n = 0;
245     u_int opt_o = 0, opt_r = 0, opt_s = 0, opt_u = 0;
246     u_int opt_A = 0;
247     int opt_N = 0;
248     int Iflag = 0, mflag = 0, oflag = 0;
249     char buf[MAXPATHLEN];
250     struct stat sb;
251     struct timeval tv;
252     struct bpb bpb;
253     struct tm *tm;
254     struct bs *bs;
255     struct bsbpb *bsbpb;
256     struct bsxbpb *bsxbpb;
257     struct bsx *bsx;
258     struct de *de;
259     u_int8_t *img;
260     const char *fname, *dtype, *bname;
261     ssize_t n;
262     time_t now;
263     u_int fat, bss, rds, cls, dir, lsn, x, x1, x2;
264     u_int extra_res, alignment=0, set_res, set_spf, set_spc, tempx, attempts=0;
265     int ch, fd, fd1;
266     off_t opt_create = 0, opt_ofs = 0;
267 
268     while ((ch = getopt(argc, argv, opts)) != -1)
269         switch (ch) {
270         case '@':
271             opt_ofs = argtooff(optarg, "offset");
272             break;
273         case 'N':
274             opt_N = 1;
275             break;
276         case 'A':
277             opt_A = 1;
278             break;
279         case 'B':
280             opt_B = optarg;
281             break;
282         case 'C':
283             opt_create = argtooff(optarg, "create size");
284             break;
285         case 'F':
286             if (strcmp(optarg, "12") &&  strcmp(optarg, "16") && strcmp(optarg, "32"))
287                 errx(1, "%s: bad FAT type", optarg);
288             opt_F = atoi(optarg);
289             break;
290         case 'I':
291             opt_I = argto4(optarg, 0, "volume ID");
292             Iflag = 1;
293             break;
294         case 'L':
295             if (!oklabel(optarg))
296                 errx(1, "%s: bad volume label", optarg);
297             opt_L = optarg;
298             break;
299         case 'O':
300             if (strlen(optarg) > 8)
301                 errx(1, "%s: bad OEM string", optarg);
302             opt_O = optarg;
303             break;
304         case 'S':
305             opt_S = argto2(optarg, 1, "bytes/sector");
306             break;
307         case 'a':
308             opt_a = argto4(optarg, 1, "sectors/FAT");
309             break;
310         case 'b':
311             opt_b = argtox(optarg, 1, "block size");
312             opt_c = 0;
313             break;
314         case 'c':
315             opt_c = argto1(optarg, 1, "sectors/cluster");
316             opt_b = 0;
317             break;
318         case 'e':
319             opt_e = argto2(optarg, 1, "directory entries");
320             break;
321         case 'f':
322             opt_f = optarg;
323             break;
324         case 'h':
325             opt_h = argto2(optarg, 1, "drive heads");
326             break;
327         case 'i':
328             opt_i = argto2(optarg, 1, "info sector");
329             break;
330         case 'k':
331             opt_k = argto2(optarg, 1, "backup sector");
332             break;
333         case 'm':
334             opt_m = argto1(optarg, 0, "media descriptor");
335             mflag = 1;
336             break;
337         case 'n':
338             opt_n = argto1(optarg, 1, "number of FATs");
339             break;
340         case 'o':
341             opt_o = argto4(optarg, 0, "hidden sectors");
342             oflag = 1;
343             break;
344         case 'r':
345             opt_r = argto2(optarg, 1, "reserved sectors");
346             break;
347         case 's':
348             opt_s = argto4(optarg, 1, "file system size");
349             break;
350         case 'u':
351             opt_u = argto2(optarg, 1, "sectors/track");
352             break;
353         default:
354             usage();
355         }
356     argc -= optind;
357     argv += optind;
358     if (argc < 1 || argc > 2)
359         usage();
360     fname = *argv++;
361     if (!opt_create && !strchr(fname, '/')) {
362         snprintf(buf, sizeof(buf), "%s%s", _PATH_DEV, fname);
363         if (!(fname = strdup(buf)))
364             err(1, "%s", buf);
365     }
366     dtype = *argv;
367     if (opt_A) {
368         if (opt_r)
369             errx(1, "align (-A) is incompatible with -r");
370         if (opt_N)
371             errx(1, "align (-A) is incompatible with -N");
372     }
373     if (opt_create) {
374         if (opt_N)
375             errx(1, "create (-C) is incompatible with -N");
376         fd = open(fname, O_RDWR | O_CREAT | O_TRUNC, 0644);
377         if (fd == -1)
378             errx(1, "failed to create %s", fname);
379         if (ftruncate(fd, opt_create))
380             errx(1, "failed to initialize %jd bytes", (intmax_t)opt_create);
381     } else if ((fd = open(fname, opt_N ? O_RDONLY : O_RDWR)) == -1)
382         err(1, "%s", fname);
383     if (fstat(fd, &sb))
384         err(1, "%s", fname);
385     if (opt_create) {
386         if (!S_ISREG(sb.st_mode))
387             warnx("warning, %s is not a regular file", fname);
388     } else {
389         if (!S_ISCHR(sb.st_mode))
390             warnx("warning, %s is not a character device", fname);
391     }
392     if (!opt_N)
393         check_mounted(fname, sb.st_mode);
394     if (opt_ofs && opt_ofs != lseek(fd, opt_ofs, SEEK_SET))
395         errx(1, "cannot seek to %jd", (intmax_t)opt_ofs);
396     memset(&bpb, 0, sizeof(bpb));
397     if (opt_f) {
398         getstdfmt(opt_f, &bpb);
399         bpb.bsec = bpb.sec;
400         bpb.sec = 0;
401         bpb.bspf = bpb.spf;
402         bpb.spf = 0;
403     }
404     if (opt_h)
405         bpb.hds = opt_h;
406     if (opt_u)
407         bpb.spt = opt_u;
408     if (opt_S)
409         bpb.bps = opt_S;
410     if (opt_s)
411         bpb.bsec = opt_s;
412     if (oflag)
413         bpb.hid = opt_o;
414     if (!(opt_f || (opt_h && opt_u && opt_S && opt_s && oflag))) {
415         off_t delta;
416         getdiskinfo(fd, fname, dtype, oflag, &bpb);
417         if (opt_s) {
418             bpb.bsec = opt_s;
419         }
420         bpb.bsec -= (opt_ofs / bpb.bps);
421         delta = bpb.bsec % bpb.spt;
422         if (delta != 0) {
423             warnx("trim %d sectors from %d to adjust to a multiple of %d",
424                   (int)delta, bpb.bsec, bpb.spt);
425             bpb.bsec -= delta;
426         }
427         if (bpb.spc == 0) {    /* set defaults */
428             if (bpb.bsec <= 6000)    /* about 3MB -> 512 bytes */
429                 bpb.spc = 1;
430             else if (bpb.bsec <= (1<<17)) /* 64M -> 4k */
431                 bpb.spc = 8;
432             else if (bpb.bsec <= (1<<19)) /* 256M -> 8k */
433                 bpb.spc = 16;
434             else if (bpb.bsec <= (1<<22)) /* 2G -> 16k, some versions of windows
435                                          require a minimum of 65527 clusters */
436                 bpb.spc = 32;
437             else
438                 bpb.spc = 64;        /* otherwise 32k */
439         }
440     }
441     if (!powerof2(bpb.bps))
442         errx(1, "bytes/sector (%u) is not a power of 2", bpb.bps);
443     if (bpb.bps < MINBPS)
444         errx(1, "bytes/sector (%u) is too small; minimum is %u",
445              bpb.bps, MINBPS);
446     if (!(fat = opt_F)) {
447         if (opt_f)
448             fat = 12;
449         else if (!opt_e && (opt_i || opt_k))
450             fat = 32;
451     }
452     if ((fat == 32 && opt_e) || (fat != 32 && (opt_i || opt_k)))
453         errx(1, "-%c is not a legal FAT%s option",
454              fat == 32 ? 'e' : opt_i ? 'i' : 'k',
455                      fat == 32 ? "32" : "12/16");
456     if (opt_f && fat == 32)
457         bpb.rde = 0;
458     if (opt_b) {
459         if (!powerof2(opt_b))
460             errx(1, "block size (%u) is not a power of 2", opt_b);
461         if (opt_b < bpb.bps)
462             errx(1, "block size (%u) is too small; minimum is %u",
463                  opt_b, bpb.bps);
464         if (opt_b > bpb.bps * MAXSPC)
465             errx(1, "block size (%u) is too large; maximum is %u", opt_b, bpb.bps * MAXSPC);
466         bpb.spc = opt_b / bpb.bps;
467     }
468     if (opt_c) {
469         if (!powerof2(opt_c))
470             errx(1, "sectors/cluster (%u) is not a power of 2", opt_c);
471         bpb.spc = opt_c;
472     }
473     if (opt_r)
474         bpb.res = opt_r;
475     if (opt_n) {
476         if (opt_n > MAXNFT)
477             errx(1, "number of FATs (%u) is too large; maximum is %u", opt_n, MAXNFT);
478         bpb.nft = opt_n;
479     }
480     if (opt_e)
481         bpb.rde = opt_e;
482     if (mflag) {
483         if (opt_m < 0xf0)
484             errx(1, "illegal media descriptor (%#x)", opt_m);
485         bpb.mid = opt_m;
486     }
487     if (opt_a)
488         bpb.bspf = opt_a;
489     if (opt_i)
490         bpb.infs = opt_i;
491     if (opt_k)
492         bpb.bkbs = opt_k;
493     bss = 1;
494     bname = NULL;
495     fd1 = -1;
496     if (opt_B) {
497         bname = opt_B;
498         if (!strchr(bname, '/')) {
499             snprintf(buf, sizeof(buf), "/boot/%s", bname);
500             if (!(bname = strdup(buf)))
501                 err(1, "%s", buf);
502         }
503         if ((fd1 = open(bname, O_RDONLY)) == -1 || fstat(fd1, &sb))
504             err(1, "%s", bname);
505         if (!S_ISREG(sb.st_mode) || sb.st_size % bpb.bps ||
506                 sb.st_size < bpb.bps || sb.st_size > bpb.bps * MAXU16)
507             errx(1, "%s: inappropriate file type or format", bname);
508         bss = sb.st_size / bpb.bps;
509     }
510     if (!bpb.nft)
511         bpb.nft = 2;
512     if (!fat) {
513         if (bpb.bsec < (bpb.res ? bpb.res : bss) +
514                 howmany((RESFTE + (bpb.spc ? MINCLS16 : MAXCLS12 + 1)) *
515                         ((bpb.spc ? 16 : 12) / BPN), bpb.bps * NPB) *
516                         bpb.nft +
517                         howmany(bpb.rde ? bpb.rde : DEFRDE,
518                                 bpb.bps / sizeof(struct de)) +
519                                 (bpb.spc ? MINCLS16 : MAXCLS12 + 1) *
520                                 (bpb.spc ? bpb.spc : howmany(DEFBLK, bpb.bps)))
521             fat = 12;
522         else if (bpb.rde || bpb.bsec <
523                 (bpb.res ? bpb.res : bss) +
524                 howmany((RESFTE + MAXCLS16) * 2, bpb.bps) * bpb.nft +
525                 howmany(DEFRDE, bpb.bps / sizeof(struct de)) +
526                 (MAXCLS16 + 1) *
527                 (bpb.spc ? bpb.spc : howmany(8192, bpb.bps)))
528             fat = 16;
529         else
530             fat = 32;
531     }
532     x = bss;
533     if (fat == 32) {
534         if (!bpb.infs) {
535             if (x == MAXU16 || x == bpb.bkbs)
536                 errx(1, "no room for info sector");
537             bpb.infs = x;
538         }
539         if (bpb.infs != MAXU16 && x <= bpb.infs)
540             x = bpb.infs + 1;
541         if (!bpb.bkbs) {
542             if (x == MAXU16)
543                 errx(1, "no room for backup sector");
544             bpb.bkbs = x;
545         } else if (bpb.bkbs != MAXU16 && bpb.bkbs == bpb.infs)
546             errx(1, "backup sector would overwrite info sector");
547         if (bpb.bkbs != MAXU16 && x <= bpb.bkbs)
548             x = bpb.bkbs + 1;
549     }
550 
551     extra_res = 0;
552     set_res = !bpb.res;
553     set_spf = !bpb.bspf;
554     set_spc = !bpb.spc;
555     tempx = x;
556     /*
557      * Attempt to align if opt_A is set. This is done by increasing the number
558      * of reserved blocks. This can cause other factors to change, which can in
559      * turn change the alignment. This should take at most 2 iterations, as
560      * increasing the reserved amount may cause the FAT size to decrease by 1,
561      * requiring another nft reserved blocks. If spc changes, it will
562      * be half of its previous size, and thus will not throw off alignment.
563      */
564     do {
565         x = tempx;
566         if (set_res)
567             bpb.res = (fat == 32 ? MAX(x, MAX(16384 / bpb.bps, 4)) : x) + extra_res;
568         else if (bpb.res < x)
569             errx(1, "too few reserved sectors");
570         if (fat != 32 && !bpb.rde)
571             bpb.rde = DEFRDE;
572         rds = howmany(bpb.rde, bpb.bps / sizeof(struct de));
573         if (set_spc)
574             for (bpb.spc = howmany(fat == 16 ? DEFBLK16 : DEFBLK, bpb.bps);
575                     bpb.spc < MAXSPC &&
576                     bpb.res +
577                     howmany((RESFTE + maxcls(fat)) * (fat / BPN),
578                             bpb.bps * NPB) * bpb.nft +
579                             rds +
580                             (u_int64_t)(maxcls(fat) + 1) * bpb.spc <= bpb.bsec;
581                     bpb.spc <<= 1);
582         if (fat != 32 && bpb.bspf > MAXU16)
583             errx(1, "too many sectors/FAT for FAT12/16");
584         x1 = bpb.res + rds;
585         x = bpb.bspf ? bpb.bspf : 1;
586         if (x1 + (u_int64_t)x * bpb.nft > bpb.bsec)
587             errx(1, "meta data exceeds file system size");
588         x1 += x * bpb.nft;
589         x = (u_int64_t)(bpb.bsec - x1) * bpb.bps * NPB /
590                 (bpb.spc * bpb.bps * NPB + fat / BPN * bpb.nft);
591         x2 = howmany((RESFTE + MIN(x, maxcls(fat))) * (fat / BPN), bpb.bps * NPB);
592         if (set_spf) {
593             if (!bpb.bspf) {
594                 bpb.bspf = x2;
595             }
596             x1 += (bpb.bspf - 1) * bpb.nft;
597         }
598         if(set_res) {
599             /* attempt to align root directory */
600             alignment = (bpb.res + bpb.bspf * bpb.nft) % bpb.spc;
601             extra_res += bpb.spc - alignment;
602         }
603         attempts++;
604     } while(opt_A && alignment != 0 && attempts < 2);
605     if (alignment != 0)
606         warnx("warning: Alignment failed.");
607 
608     cls = (bpb.bsec - x1) / bpb.spc;
609     x = (u_int64_t)bpb.bspf * bpb.bps * NPB / (fat / BPN) - RESFTE;
610     if (cls > x)
611         cls = x;
612     if (bpb.bspf < x2)
613         warnx("warning: sectors/FAT limits file system to %u clusters", cls);
614     if (cls < mincls(fat))
615         errx(1, "%u clusters too few clusters for FAT%u, need %u", cls, fat, mincls(fat));
616     if (cls > maxcls(fat)) {
617         cls = maxcls(fat);
618         bpb.bsec = x1 + (cls + 1) * bpb.spc - 1;
619         warnx("warning: FAT type limits file system to %u sectors", bpb.bsec);
620     }
621     printf("%s: %u sector%s in %u FAT%u cluster%s (%u bytes/cluster)\n",
622            fname, cls * bpb.spc, cls * bpb.spc == 1 ? "" : "s", cls, fat,
623            cls == 1 ? "" : "s", bpb.bps * bpb.spc);
624     if (!bpb.mid)
625         bpb.mid = !bpb.hid ? 0xf0 : 0xf8;
626     if (fat == 32)
627         bpb.rdcl = RESFTE;
628     if (bpb.hid + bpb.bsec <= MAXU16) {
629         bpb.sec = bpb.bsec;
630         bpb.bsec = 0;
631     }
632     if (fat != 32) {
633         bpb.spf = bpb.bspf;
634         bpb.bspf = 0;
635     }
636     print_bpb(&bpb);
637     if (!opt_N) {
638         gettimeofday(&tv, NULL);
639         now = tv.tv_sec;
640         tm = localtime(&now);
641         if (!(img = malloc(bpb.bps)))
642             err(1, "%u", bpb.bps);
643         dir = bpb.res + (bpb.spf ? bpb.spf : bpb.bspf) * bpb.nft;
644         for (lsn = 0; lsn < dir + (fat == 32 ? bpb.spc : rds); lsn++) {
645             x = lsn;
646             if (opt_B && fat == 32 && bpb.bkbs != MAXU16 && bss <= bpb.bkbs && x >= bpb.bkbs) {
647                 x -= bpb.bkbs;
648                 if (!x && lseek(fd1, opt_ofs, SEEK_SET))
649                     err(1, "%s", bname);
650             }
651             if (opt_B && x < bss) {
652                 if ((n = read(fd1, img, bpb.bps)) == -1)
653                     err(1, "%s", bname);
654                 if ((unsigned)n != bpb.bps)
655                     errx(1, "%s: can't read sector %u", bname, x);
656             } else
657                 memset(img, 0, bpb.bps);
658             if (!lsn || (fat == 32 && bpb.bkbs != MAXU16 && lsn == bpb.bkbs)) {
659                 x1 = sizeof(struct bs);
660                 bsbpb = (struct bsbpb *)(img + x1);
661                 mk2(bsbpb->bps, bpb.bps);
662                 mk1(bsbpb->spc, bpb.spc);
663                 mk2(bsbpb->res, bpb.res);
664                 mk1(bsbpb->nft, bpb.nft);
665                 mk2(bsbpb->rde, bpb.rde);
666                 mk2(bsbpb->sec, bpb.sec);
667                 mk1(bsbpb->mid, bpb.mid);
668                 mk2(bsbpb->spf, bpb.spf);
669                 mk2(bsbpb->spt, bpb.spt);
670                 mk2(bsbpb->hds, bpb.hds);
671                 mk4(bsbpb->hid, bpb.hid);
672                 mk4(bsbpb->bsec, bpb.bsec);
673                 x1 += sizeof(struct bsbpb);
674                 if (fat == 32) {
675                     bsxbpb = (struct bsxbpb *)(img + x1);
676                     mk4(bsxbpb->bspf, bpb.bspf);
677                     mk2(bsxbpb->xflg, 0);
678                     mk2(bsxbpb->vers, 0);
679                     mk4(bsxbpb->rdcl, bpb.rdcl);
680                     mk2(bsxbpb->infs, bpb.infs);
681                     mk2(bsxbpb->bkbs, bpb.bkbs);
682                     x1 += sizeof(struct bsxbpb);
683                 }
684                 bsx = (struct bsx *)(img + x1);
685                 mk1(bsx->sig, 0x29);
686                 if (Iflag)
687                     x = opt_I;
688                 else
689                     x = (((u_int)(1 + tm->tm_mon) << 8 |
690                             (u_int)tm->tm_mday) +
691                             ((u_int)tm->tm_sec << 8 |
692                                     (u_int)(tv.tv_usec / 10))) << 16 |
693                                     ((u_int)(1900 + tm->tm_year) +
694                                             ((u_int)tm->tm_hour << 8 |
695                                                     (u_int)tm->tm_min));
696                 mk4(bsx->volid, x);
697                 mklabel(bsx->label, opt_L ? opt_L : "NO NAME");
698                 sprintf(buf, "FAT%u", fat);
699                 setstr(bsx->type, buf, sizeof(bsx->type));
700                 if (!opt_B) {
701                     x1 += sizeof(struct bsx);
702                     bs = (struct bs *)img;
703                     mk1(bs->jmp[0], 0xeb);
704                     mk1(bs->jmp[1], x1 - 2);
705                     mk1(bs->jmp[2], 0x90);
706                     setstr(bs->oem, opt_O ? opt_O : "BSD  4.4",
707                             sizeof(bs->oem));
708                     memcpy(img + x1, bootcode, sizeof(bootcode));
709                     mk2(img + MINBPS - 2, DOSMAGIC);
710                 }
711             } else if (fat == 32 && bpb.infs != MAXU16 &&
712                     (lsn == bpb.infs || (bpb.bkbs != MAXU16 &&
713                                     lsn == bpb.bkbs + bpb.infs))) {
714                 mk4(img, 0x41615252);
715                 mk4(img + MINBPS - 28, 0x61417272);
716                 mk4(img + MINBPS - 24, 0xffffffff);
717                 mk4(img + MINBPS - 20, bpb.rdcl);
718                 mk2(img + MINBPS - 2, DOSMAGIC);
719             } else if (lsn >= bpb.res && lsn < dir &&
720                     !((lsn - bpb.res) % (bpb.spf ? bpb.spf : bpb.bspf))) {
721                 mk1(img[0], bpb.mid);
722                 for (x = 1; x < fat * (fat == 32 ? 3 : 2) / 8; x++)
723                     mk1(img[x], fat == 32 && x % 4 == 3 ? 0x0f : 0xff);
724             } else if (lsn == dir && opt_L) {
725                 de = (struct de *)img;
726                 mklabel(de->namext, opt_L);
727                 mk1(de->attr, 050);
728                 x = (u_int)tm->tm_hour << 11 |
729                         (u_int)tm->tm_min << 5 |
730                         (u_int)tm->tm_sec >> 1;
731                 mk2(de->time, x);
732                 x = (u_int)(tm->tm_year - 80) << 9 |
733                         (u_int)(tm->tm_mon + 1) << 5 |
734                         (u_int)tm->tm_mday;
735                 mk2(de->date, x);
736             }
737             if ((n = write(fd, img, bpb.bps)) == -1)
738                 err(1, "%s", fname);
739             if ((unsigned)n != bpb.bps) {
740                 errx(1, "%s: can't write sector %u", fname, lsn);
741                 exit(1);
742             }
743         }
744     }
745     return 0;
746 }
747 
748 /*
749  * Exit with error if file system is mounted.
750  */
check_mounted(const char * fname,mode_t mode)751 static void check_mounted(const char *fname, mode_t mode)
752 {
753 #ifdef ANDROID
754     warnx("Skipping mount checks");
755 #else
756     struct statfs *mp;
757     const char *s1, *s2;
758     size_t len;
759     int n, r;
760 
761     if (!(n = getmntinfo(&mp, MNT_NOWAIT)))
762         err(1, "getmntinfo");
763     len = strlen(_PATH_DEV);
764     s1 = fname;
765     if (!strncmp(s1, _PATH_DEV, len))
766         s1 += len;
767     r = S_ISCHR(mode) && s1 != fname && *s1 == 'r';
768     for (; n--; mp++) {
769         s2 = mp->f_mntfromname;
770         if (!strncmp(s2, _PATH_DEV, len))
771             s2 += len;
772         if ((r && s2 != mp->f_mntfromname && !strcmp(s1 + 1, s2)) || !strcmp(s1, s2))
773             errx(1, "%s is mounted on %s", fname, mp->f_mntonname);
774     }
775 #endif
776 }
777 
778 /*
779  * Get a standard format.
780  */
getstdfmt(const char * fmt,struct bpb * bpb)781 static void getstdfmt(const char *fmt, struct bpb *bpb)
782 {
783     u_int x, i;
784 
785     x = sizeof(stdfmt) / sizeof(stdfmt[0]);
786     for (i = 0; i < x && strcmp(fmt, stdfmt[i].name); i++);
787     if (i == x)
788         errx(1, "%s: unknown standard format", fmt);
789     *bpb = stdfmt[i].bpb;
790 }
791 
792 /*
793  * Get disk slice, partition, and geometry information.
794  */
795 
796 #ifdef ANDROID
getdiskinfo(int fd,const char * fname,const char * dtype,__unused int oflag,struct bpb * bpb)797 static void getdiskinfo(int fd, const char *fname, const char *dtype,
798                         __unused int oflag,struct bpb *bpb)
799 {
800     struct hd_geometry geom;
801     u_long block_size;
802 
803     if (ioctl(fd, BLKSSZGET, &bpb->bps)) {
804         fprintf(stderr, "Error getting bytes / sector (%s)\n", strerror(errno));
805         exit(1);
806     }
807 
808     ckgeom(fname, bpb->bps, "bytes/sector");
809 
810     if (ioctl(fd, BLKGETSIZE, &block_size)) {
811         fprintf(stderr, "Error getting blocksize (%s)\n", strerror(errno));
812         exit(1);
813     }
814 
815     if (block_size > UINT32_MAX) {
816         fprintf(stderr, "Error blocksize too large: %lu\n", block_size);
817         exit(1);
818     }
819 
820     bpb->bsec = (u_int)block_size;
821 
822     if (ioctl(fd, HDIO_GETGEO, &geom)) {
823         fprintf(stderr, "Error getting gemoetry (%s) - trying sane values\n", strerror(errno));
824         geom.heads = 64;
825         geom.sectors = 63;
826     }
827 
828     if (!geom.heads) {
829         printf("Bogus heads from kernel - setting sane value\n");
830         geom.heads = 64;
831     }
832 
833     if (!geom.sectors) {
834         printf("Bogus sectors from kernel - setting sane value\n");
835         geom.sectors = 63;
836     }
837 
838     bpb->spt = geom.sectors;
839     ckgeom(fname, bpb->spt, "sectors/track");
840 
841     bpb->hds = geom.heads;
842     ckgeom(fname, bpb->hds, "drive heads");
843 }
844 
845 #else
846 
getdiskinfo(int fd,const char * fname,const char * dtype,__unused int oflag,struct bpb * bpb)847 static void getdiskinfo(int fd, const char *fname, const char *dtype,
848                         __unused int oflag, struct bpb *bpb)
849 {
850     struct disklabel *lp, dlp;
851     struct fd_type type;
852     off_t ms, hs = 0;
853 
854     lp = NULL;
855 
856     /* If the user specified a disk type, try to use that */
857     if (dtype != NULL) {
858         lp = getdiskbyname(dtype);
859     }
860 
861     /* Maybe it's a floppy drive */
862     if (lp == NULL) {
863         if (ioctl(fd, DIOCGMEDIASIZE, &ms) == -1) {
864             struct stat st;
865 
866             if (fstat(fd, &st))
867                 err(1, "Cannot get disk size");
868             /* create a fake geometry for a file image */
869             ms = st.st_size;
870             dlp.d_secsize = 512;
871             dlp.d_nsectors = 63;
872             dlp.d_ntracks = 255;
873             dlp.d_secperunit = ms / dlp.d_secsize;
874             lp = &dlp;
875         } else if (ioctl(fd, FD_GTYPE, &type) != -1) {
876             dlp.d_secsize = 128 << type.secsize;
877             dlp.d_nsectors = type.sectrac;
878             dlp.d_ntracks = type.heads;
879             dlp.d_secperunit = ms / dlp.d_secsize;
880             lp = &dlp;
881         }
882     }
883 
884     /* Maybe it's a fixed drive */
885     if (lp == NULL) {
886         if (ioctl(fd, DIOCGDINFO, &dlp) == -1) {
887             if (bpb->bps == 0 && ioctl(fd, DIOCGSECTORSIZE, &dlp.d_secsize) == -1)
888                 errx(1, "Cannot get sector size, %s", strerror(errno));
889 
890             /* XXX Should we use bpb->bps if it's set? */
891             dlp.d_secperunit = ms / dlp.d_secsize;
892 
893             if (bpb->spt == 0 && ioctl(fd, DIOCGFWSECTORS, &dlp.d_nsectors) == -1) {
894                 warnx("Cannot get number of sectors per track, %s", strerror(errno));
895                 dlp.d_nsectors = 63;
896             }
897             if (bpb->hds == 0 && ioctl(fd, DIOCGFWHEADS, &dlp.d_ntracks) == -1) {
898                 warnx("Cannot get number of heads, %s", strerror(errno));
899                 if (dlp.d_secperunit <= 63*1*1024)
900                     dlp.d_ntracks = 1;
901                 else if (dlp.d_secperunit <= 63*16*1024)
902                     dlp.d_ntracks = 16;
903                 else
904                     dlp.d_ntracks = 255;
905             }
906         }
907 
908         hs = (ms / dlp.d_secsize) - dlp.d_secperunit;
909         lp = &dlp;
910     }
911 
912     if (bpb->bps == 0)
913         bpb->bps = ckgeom(fname, lp->d_secsize, "bytes/sector");
914     if (bpb->spt == 0)
915         bpb->spt = ckgeom(fname, lp->d_nsectors, "sectors/track");
916     if (bpb->hds == 0)
917         bpb->hds = ckgeom(fname, lp->d_ntracks, "drive heads");
918     if (bpb->bsec == 0)
919         bpb->bsec = lp->d_secperunit;
920     if (bpb->hid == 0)
921         bpb->hid = hs;
922 }
923 #endif
924 
925 /*
926  * Print out BPB values.
927  */
print_bpb(struct bpb * bpb)928 static void print_bpb(struct bpb *bpb)
929 {
930     printf("bps=%u spc=%u res=%u nft=%u", bpb->bps, bpb->spc, bpb->res,
931            bpb->nft);
932     if (bpb->rde)
933         printf(" rde=%u", bpb->rde);
934     if (bpb->sec)
935         printf(" sec=%u", bpb->sec);
936     printf(" mid=%#x", bpb->mid);
937     if (bpb->spf)
938         printf(" spf=%u", bpb->spf);
939     printf(" spt=%u hds=%u hid=%u", bpb->spt, bpb->hds, bpb->hid);
940     if (bpb->bsec)
941         printf(" bsec=%u", bpb->bsec);
942     if (!bpb->spf) {
943         printf(" bspf=%u rdcl=%u", bpb->bspf, bpb->rdcl);
944         printf(" infs=");
945         printf(bpb->infs == MAXU16 ? "%#x" : "%u", bpb->infs);
946         printf(" bkbs=");
947         printf(bpb->bkbs == MAXU16 ? "%#x" : "%u", bpb->bkbs);
948     }
949     printf("\n");
950 }
951 
952 /*
953  * Check a disk geometry value.
954  */
ckgeom(const char * fname,u_int val,const char * msg)955 static u_int ckgeom(const char *fname, u_int val, const char *msg)
956 {
957     if (!val)
958         errx(1, "%s: no default %s", fname, msg);
959     if (val > MAXU16)
960         errx(1, "%s: illegal %s %d", fname, msg, val);
961     return val;
962 }
963 
964 /*
965  * Convert and check a numeric option argument.
966  */
argtou(const char * arg,u_int lo,u_int hi,const char * msg)967 static u_int argtou(const char *arg, u_int lo, u_int hi, const char *msg)
968 {
969     char *s;
970     u_long x;
971 
972     errno = 0;
973     x = strtoul(arg, &s, 0);
974     if (errno || !*arg || *s || x < lo || x > hi)
975         errx(1, "%s: bad %s", arg, msg);
976     return x;
977 }
978 
979 /*
980  * Same for off_t, with optional skmgpP suffix
981  */
argtooff(const char * arg,const char * msg)982 static off_t argtooff(const char *arg, const char *msg)
983 {
984     char *s;
985     off_t x;
986 
987     x = strtoll(arg, &s, 0);
988     /* allow at most one extra char */
989     if (errno || x < 0 || (s[0] && s[1]) )
990         errx(1, "%s: bad %s", arg, msg);
991     if (*s) {    /* the extra char is the multiplier */
992         switch (*s) {
993             default:
994                 errx(1, "%s: bad %s", arg, msg);
995                 /* notreached */
996 
997             case 's':       /* sector */
998             case 'S':
999                 x <<= 9;    /* times 512 */
1000                 break;
1001 
1002             case 'k':       /* kilobyte */
1003             case 'K':
1004                 x <<= 10;   /* times 1024 */
1005                 break;
1006 
1007             case 'm':       /* megabyte */
1008             case 'M':
1009                 x <<= 20;   /* times 1024*1024 */
1010                 break;
1011 
1012             case 'g':       /* gigabyte */
1013             case 'G':
1014                 x <<= 30;   /* times 1024*1024*1024 */
1015                 break;
1016 
1017             case 'p':       /* partition start */
1018             case 'P':       /* partition start */
1019             case 'l':       /* partition length */
1020             case 'L':       /* partition length */
1021                 errx(1, "%s: not supported yet %s", arg, msg);
1022                 /* notreached */
1023         }
1024     }
1025     return x;
1026 }
1027 
1028 /*
1029  * Check a volume label.
1030  */
oklabel(const char * src)1031 static int oklabel(const char *src)
1032 {
1033     int c, i;
1034 
1035     for (i = 0; i <= 11; i++) {
1036         c = (u_char)*src++;
1037         if (c < ' ' + !i || strchr("\"*+,./:;<=>?[\\]|", c))
1038             break;
1039     }
1040     return i && !c;
1041 }
1042 
1043 /*
1044  * Make a volume label.
1045  */
mklabel(u_int8_t * dest,const char * src)1046 static void mklabel(u_int8_t *dest, const char *src)
1047 {
1048     int c, i;
1049 
1050     for (i = 0; i < 11; i++) {
1051         c = *src ? toupper(*src++) : ' ';
1052         *dest++ = !i && c == '\xe5' ? 5 : c;
1053     }
1054 }
1055 
1056 /*
1057  * Copy string, padding with spaces.
1058  */
setstr(u_int8_t * dest,const char * src,size_t len)1059 static void setstr(u_int8_t *dest, const char *src, size_t len)
1060 {
1061     while (len--)
1062         *dest++ = *src ? *src++ : ' ';
1063 }
1064 
1065 /*
1066  * Print usage message.
1067  */
usage(void)1068 static void usage(void)
1069 {
1070     fprintf(stderr,
1071             "usage: newfs_msdos [ -options ] special [disktype]\n"
1072             "where the options are:\n"
1073             "\t-@ create file system at specified offset\n"
1074             "\t-A Attempt to cluster align root directory\n"
1075             "\t-B get bootstrap from file\n"
1076             "\t-C create image file with specified size\n"
1077             "\t-F FAT type (12, 16, or 32)\n"
1078             "\t-I volume ID\n"
1079             "\t-L volume label\n"
1080             "\t-N don't create file system: just print out parameters\n"
1081             "\t-O OEM string\n"
1082             "\t-S bytes/sector\n"
1083             "\t-a sectors/FAT\n"
1084             "\t-b block size\n"
1085             "\t-c sectors/cluster\n"
1086             "\t-e root directory entries\n"
1087             "\t-f standard format\n"
1088             "\t-h drive heads\n"
1089             "\t-i file system info sector\n"
1090             "\t-k backup boot sector\n"
1091             "\t-m media descriptor\n"
1092             "\t-n number of FATs\n"
1093             "\t-o hidden sectors\n"
1094             "\t-r reserved sectors\n"
1095             "\t-s file system size (sectors)\n"
1096             "\t-u sectors/track\n");
1097     exit(1);
1098 }
1099