summaryrefslogtreecommitdiff
path: root/mount.c
blob: 713e5e850bb6c6a5329407f987d8fafe578e6a1f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
/*
 * Mini mount implementation for busybox
 *
 * Copyright (C) 1995, 1996 by Bruce Perens <bruce@pixar.com>.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 * 3/21/1999	Charles P. Wright <cpwright@cpwright.com>
 *		searches through fstab when -a is passed
 *		will try mounting stuff with all fses when passed -t auto
 *
 * 1999-04-17	Dave Cinege...Rewrote -t auto. Fixed ro mtab.
 *
 * 1999-10-07	Erik Andersen <andersen@lineo.com>, <andersee@debian.org>.
 *              Rewrite of a lot of code. Removed mtab usage (I plan on
 *              putting it back as a compile-time option some time), 
 *              major adjustments to option parsing, and some serious 
 *              dieting all around.
 *
 * 1999-11-06	mtab suppport is back - andersee
 *
 * 2000-01-12   Ben Collins <bcollins@debian.org>, Borrowed utils-linux's
 *              mount to add loop support.
 */

#include "internal.h"
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <stdio.h>
#include <mntent.h>
#include <sys/mount.h>
#include <ctype.h>
#include <fstab.h>

#if defined BB_FEATURE_MOUNT_LOOP
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/loop.h>

static int set_loop(const char *device, const char *file, int offset, int *loopro);
static char *find_unused_loop_device (void);

static int use_loop = 0;
#endif

extern const char mtab_file[]; /* Defined in utility.c */

static const char mount_usage[] = "\tmount [flags]\n"
    "\tmount [flags] device directory [-o options,more-options]\n"
    "\n"
    "Flags:\n"
    "\t-a:\tMount all file systems in fstab.\n"
#ifdef BB_MTAB
    "\t-f:\t\"Fake\" mount. Add entry to mount table but don't mount it.\n"
    "\t-n:\tDon't write a mount table entry.\n"
#endif
    "\t-o option:\tOne of many filesystem options, listed below.\n"
    "\t-r:\tMount the filesystem read-only.\n"
    "\t-t filesystem-type:\tSpecify the filesystem type.\n"
    "\t-w:\tMount for reading and writing (default).\n"
    "\n"
    "Options for use with the \"-o\" flag:\n"
    "\tasync / sync:\tWrites are asynchronous / synchronous.\n"
    "\tdev / nodev:\tAllow use of special device files / disallow them.\n"
    "\texec / noexec:\tAllow use of executable files / disallow them.\n"
#if defined BB_FEATURE_MOUNT_LOOP
    "\tloop: Mounts a file via loop device.\n"
#endif
    "\tsuid / nosuid:\tAllow set-user-id-root programs / disallow them.\n"
    "\tremount: Re-mount a currently-mounted filesystem, changing its flags.\n"
    "\tro / rw: Mount for read-only / read-write.\n"
    "\t"
    "There are EVEN MORE flags that are specific to each filesystem.\n"
    "You'll have to see the written documentation for those.\n";


struct mount_options {
    const char *name;
    unsigned long and;
    unsigned long or;
};

static const struct mount_options mount_options[] = {
    {"async", ~MS_SYNCHRONOUS, 0},
    {"defaults", ~0, 0},
    {"dev", ~MS_NODEV, 0},
    {"exec", ~MS_NOEXEC, 0},
    {"nodev", ~0, MS_NODEV},
    {"noexec", ~0, MS_NOEXEC},
    {"nosuid", ~0, MS_NOSUID},
    {"remount", ~0, MS_REMOUNT},
    {"ro", ~0, MS_RDONLY},
    {"rw", ~MS_RDONLY, 0},
    {"suid", ~MS_NOSUID, 0},
    {"sync", ~0, MS_SYNCHRONOUS},
    {0, 0, 0}
};

static int
do_mount(char* specialfile, char* dir, char* filesystemtype, 
	long flags, void* string_flags, int useMtab, int fakeIt, char* mtab_opts)
{
    int status=0;

#if defined BB_MTAB
    if (fakeIt==FALSE)
#endif
    {
#if defined BB_FEATURE_MOUNT_LOOP
	if (use_loop) {
	    int loro = flags & MS_RDONLY;
	    char *lofile = specialfile;
	    specialfile = find_unused_loop_device();
	    if (specialfile == NULL) {
		fprintf(stderr, "Could not find a spare loop device\n");
		exit(1);
	    }
	    if (set_loop (specialfile, lofile, 0, &loro)) {
		fprintf(stderr, "Could not setup loop device\n");
		exit(1);
	    }
	    if (!(flags & MS_RDONLY) && loro) { /* loop is ro, but wanted rw */
		fprintf(stderr, "WARNING: loop device is read-only\n");
		flags &= ~MS_RDONLY;
	    }
	}
#endif
	status=mount(specialfile, dir, filesystemtype, flags, string_flags);
    }
#if defined BB_MTAB
    if (status == 0) {
	if (useMtab==TRUE)
	    write_mtab(specialfile, dir, filesystemtype, flags, mtab_opts);
	return 0;
    }
    else
#endif
	return(status);
}



#if defined BB_MTAB
#define whine_if_fstab_is_missing() {} 
#else
extern void whine_if_fstab_is_missing()
{
    struct stat statBuf;
    if (stat("/etc/fstab", &statBuf) < 0) 
	fprintf(stderr, "/etc/fstab file missing -- install one to name /dev/root.\n\n");
}
#endif


/* Seperate standard mount options from the nonstandard string options */
static void
parse_mount_options ( char *options, unsigned long *flags, char *strflags)
{
    while (options) {
	int gotone=FALSE;
	char *comma = strchr (options, ',');
	const struct mount_options* f = mount_options;
	if (comma)
	    *comma = '\0';

	while (f->name != 0) {
	    if (strcasecmp (f->name, options) == 0) {

		*flags &= f->and;
		*flags |= f->or;
		gotone=TRUE;
		break;
	    }
	    f++;
	}
#if defined BB_FEATURE_MOUNT_LOOP
	if (gotone==FALSE && !strcasecmp ("loop", options)) { /* loop device support */
	    use_loop = 1;
	    gotone=TRUE;
	}
#endif
	if (*strflags && strflags!= '\0' && gotone==FALSE) {
	    char *temp=strflags;
	    temp += strlen (strflags);
	    *temp++ = ',';
	    *temp++ = '\0';
	}
	if (gotone==FALSE)
	    strcat (strflags, options);
	if (comma) {
	    *comma = ',';
	    options = ++comma;
	} else {
	    break;
	}
    }
}

int
mount_one(char *blockDevice, char *directory, char *filesystemType,
	   unsigned long flags, char *string_flags, int useMtab, int fakeIt, char *mtab_opts)
{
    int status = 0;

    char buf[255];

#if defined BB_FEATURE_USE_PROCFS
    if (strcmp(filesystemType, "auto") == 0) {
	FILE *f = fopen ("/proc/filesystems", "r");

	if (f == NULL)
	    return( FALSE);

	while (fgets (buf, sizeof (buf), f) != NULL) {
	    filesystemType = buf;
	    if (*filesystemType == '\t') {	// Not a nodev filesystem

		// Add NULL termination to each line
		while (*filesystemType && *filesystemType != '\n')
		    filesystemType++;
		*filesystemType = '\0';

		filesystemType = buf;
		filesystemType++;	// hop past tab

		status = do_mount (blockDevice, directory, filesystemType,
				flags | MS_MGC_VAL, string_flags, useMtab, 
				fakeIt, mtab_opts);
		if (status == 0)
		    break;
	    }
	}
	fclose (f);
    } else
#endif
    {
	status = do_mount (blockDevice, directory, filesystemType,
			flags | MS_MGC_VAL, string_flags, useMtab, 
			fakeIt, mtab_opts);
    }

    if (status) {
	fprintf (stderr, "Mounting %s on %s failed: %s\n",
		 blockDevice, directory, strerror(errno));
	return (FALSE);
    }
    return (TRUE);
}

extern int mount_main (int argc, char **argv)
{
    char string_flags_buf[1024]="";
    char *string_flags = string_flags_buf;
    char *extra_opts = string_flags_buf;
    unsigned long flags = 0;
    char *filesystemType = "auto";
    char *device = NULL;
    char *directory = NULL;
    int all = FALSE;
    int fakeIt = FALSE;
    int useMtab = TRUE;
    int i;

    /* Only compiled in if BB_MTAB is not defined */
    whine_if_fstab_is_missing();

    if (argc == 1) {
	FILE *mountTable = setmntent (mtab_file, "r");
	if (mountTable) {
	    struct mntent *m;
	    while ((m = getmntent (mountTable)) != 0) {
		struct fstab* fstabItem;
		char *blockDevice = m->mnt_fsname;
		/* Note that if /etc/fstab is missing, libc can't fix up /dev/root for us */
		if (strcmp (blockDevice, "/dev/root") == 0) {
		    fstabItem = getfsfile ("/");
		    if (fstabItem != NULL)
			blockDevice = fstabItem->fs_spec;
		}
		printf ("%s on %s type %s (%s)\n", blockDevice, m->mnt_dir,
			m->mnt_type, m->mnt_opts);
	    }
	    endmntent (mountTable);
	} else {
	    perror(mtab_file);
	}
	exit( TRUE);
    }


    /* Parse options */
    i = --argc;
    argv++;
    while (i > 0 && **argv) {
	if (**argv == '-') {
	    char *opt = *argv;
	    while (i>0 && *++opt) switch (*opt) {
	    case 'o':
		if (--i == 0) {
		    goto goodbye;
		}
		parse_mount_options (*(++argv), &flags, string_flags);
		break;
	    case 'r':
		flags |= MS_RDONLY;
		break;
	    case 't':
		if (--i == 0) {
		    goto goodbye;
		}
		filesystemType = *(++argv);
		break;
	    case 'w':
		flags &= ~MS_RDONLY;
		break;
	    case 'a':
		all = TRUE;
		break;
#ifdef BB_MTAB
	    case 'f':
		fakeIt = TRUE;
		break;
	    case 'n':
		useMtab = FALSE;
		break;
#endif
	    case 'v':
	    case 'h':
	    case '-':
		goto goodbye;
	    }
	} else {
	    if (device == NULL)
		device=*argv;
	    else if (directory == NULL)
		directory=*argv;
	    else {
		goto goodbye;
	    }
	}
	i--;
	argv++;
    }

    if (all == TRUE) {
	struct mntent *m;
	FILE *f = setmntent ("/etc/fstab", "r");

	if (f == NULL) {
	    perror("/etc/fstab");
	    exit( FALSE); 
	}
	while ((m = getmntent (f)) != NULL) {
	    // If the file system isn't noauto, and isn't mounted on /, 
	    // and isn't swap or nfs, then mount it
	    if ((!strstr (m->mnt_opts, "noauto")) &&
		    (m->mnt_dir[1] != '\0') && 
		    (!strstr (m->mnt_type, "swap")) && 
		    (!strstr (m->mnt_type, "nfs"))) 
	    {
		flags = 0;
		*string_flags = '\0';
		parse_mount_options(m->mnt_opts, &flags, string_flags);
		mount_one (m->mnt_fsname, m->mnt_dir, m->mnt_type, 
			flags, string_flags, useMtab, fakeIt, extra_opts);
	    }
	}
	endmntent (f);
    } else {
	if (device && directory) {
#ifdef BB_NFSMOUNT
	    if (strcmp(filesystemType, "nfs") == 0) {
		if (nfsmount(device, directory, &flags, &extra_opts, &string_flags, 1) != 0)
		exit(FALSE);
	    }
#endif
	    exit (mount_one (device, directory, filesystemType, 
			flags, string_flags, useMtab, fakeIt, extra_opts));
	} else {
	    goto goodbye;
	}
    }
    exit( TRUE);

goodbye:
    usage( mount_usage);
}

#if defined BB_FEATURE_MOUNT_LOOP
static int set_loop(const char *device, const char *file, int offset, int *loopro)
{
	struct loop_info loopinfo;
	int	fd, ffd, mode;
	
	mode = *loopro ? O_RDONLY : O_RDWR;
	if ((ffd = open (file, mode)) < 0 && !*loopro
	    && (errno != EROFS || (ffd = open (file, mode = O_RDONLY)) < 0)) {
	  perror (file);
	  return 1;
	}
	if ((fd = open (device, mode)) < 0) {
	  close(ffd);
	  perror (device);
	  return 1;
	}
	*loopro = (mode == O_RDONLY);

	memset(&loopinfo, 0, sizeof(loopinfo));
	strncpy(loopinfo.lo_name, file, LO_NAME_SIZE);
	loopinfo.lo_name[LO_NAME_SIZE-1] = 0;

	loopinfo.lo_offset = offset;

	loopinfo.lo_encrypt_key_size = 0;
	if (ioctl(fd, LOOP_SET_FD, ffd) < 0) {
		perror("ioctl: LOOP_SET_FD");
		exit(1);
	}
	if (ioctl(fd, LOOP_SET_STATUS, &loopinfo) < 0) {
		(void) ioctl(fd, LOOP_CLR_FD, 0);
		perror("ioctl: LOOP_SET_STATUS");
		exit(1);
	}
	close(fd);
	close(ffd);
	return 0;
}

static char *find_unused_loop_device (void)
{
    char dev[20];
    int i, fd, somedev = 0, someloop = 0;
    struct stat statbuf;
    struct loop_info loopinfo;

    for(i = 0; i < 256; i++) {
      sprintf(dev, "/dev/loop%d", i);
      if (stat (dev, &statbuf) == 0 && S_ISBLK(statbuf.st_mode)) {
	somedev++;
	fd = open (dev, O_RDONLY);
	if (fd >= 0) {
	  if(ioctl (fd, LOOP_GET_STATUS, &loopinfo) == 0)
	    someloop++; /* in use */
	  else if (errno == ENXIO) {
	    close (fd);
	    return strdup(dev); /* probably free */
	  }
	  close (fd);
        }
	continue;
      }
      if (i >= 7)
	break;
    }
    return NULL;
}
#endif /* BB_FEATURE_MOUNT_LOOP */