summaryrefslogtreecommitdiffstats
path: root/sbin/umount/umount.c
blob: f179a4c43b1f89f482c85b6feee35e2829a0641c (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
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
/*-
 * Copyright (c) 1980, 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef lint
static const char copyright[] =
"@(#) Copyright (c) 1980, 1989, 1993\n\
	The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)umount.c	8.8 (Berkeley) 5/8/95";
#endif
static const char rcsid[] =
  "$FreeBSD$";
#endif /* not lint */

#include <sys/param.h>
#include <sys/mount.h>
#include <sys/socket.h>
#include <sys/stat.h>

#include <netdb.h>
#include <rpc/rpc.h>
#include <rpcsvc/mount.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fstab.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "mounttab.h"

typedef enum { FIND, REMOVE, CHECKUNIQUE } dowhat;

static struct addrinfo *nfshost_ai = NULL;
static int	fflag, vflag;
static char	*nfshost;

struct statfs *checkmntlist(char *);
int	 checkvfsname (const char *, char **);
struct statfs *getmntentry(const char *fromname, const char *onname,
	     fsid_t *fsid, dowhat what);
char   **makevfslist (const char *);
size_t	 mntinfo (struct statfs **);
int	 namematch (struct addrinfo *);
int	 parsehexfsid(const char *hex, fsid_t *fsid);
int	 sacmp (void *, void *);
int	 umountall (char **);
int	 checkname (char *, char **);
int	 umountfs(struct statfs *sfs);
void	 usage (void);
int	 xdr_dir (XDR *, char *);

int
main(int argc, char *argv[])
{
	int all, errs, ch, mntsize, error;
	char **typelist = NULL;
	struct statfs *mntbuf, *sfs;
	struct addrinfo hints;

	all = errs = 0;
	while ((ch = getopt(argc, argv, "AaF:fh:t:v")) != -1)
		switch (ch) {
		case 'A':
			all = 2;
			break;
		case 'a':
			all = 1;
			break;
		case 'F':
			setfstab(optarg);
			break;
		case 'f':
			fflag = MNT_FORCE;
			break;
		case 'h':	/* -h implies -A. */
			all = 2;
			nfshost = optarg;
			break;
		case 't':
			if (typelist != NULL)
				err(1, "only one -t option may be specified");
			typelist = makevfslist(optarg);
			break;
		case 'v':
			vflag = 1;
			break;
		default:
			usage();
			/* NOTREACHED */
		}
	argc -= optind;
	argv += optind;

	/* Start disks transferring immediately. */
	if ((fflag & MNT_FORCE) == 0)
		sync();

	if ((argc == 0 && !all) || (argc != 0 && all))
		usage();

	/* -h implies "-t nfs" if no -t flag. */
	if ((nfshost != NULL) && (typelist == NULL))
		typelist = makevfslist("nfs");

	if (nfshost != NULL) {
		memset(&hints, 0, sizeof hints);
		error = getaddrinfo(nfshost, NULL, &hints, &nfshost_ai);
		if (error)
			errx(1, "%s: %s", nfshost, gai_strerror(error));
	}

	switch (all) {
	case 2:
		if ((mntsize = mntinfo(&mntbuf)) <= 0)
			break;
		/*
		 * We unmount the nfs-mounts in the reverse order
		 * that they were mounted.
		 */
		for (errs = 0, mntsize--; mntsize > 0; mntsize--) {
			sfs = &mntbuf[mntsize];
			if (checkvfsname(sfs->f_fstypename, typelist))
				continue;
			if (strcmp(sfs->f_mntonname, "/dev") == 0)
				continue;
			if (umountfs(sfs) != 0)
				errs = 1;
		}
		free(mntbuf);
		break;
	case 1:
		if (setfsent() == 0)
			err(1, "%s", getfstab());
		errs = umountall(typelist);
		break;
	case 0:
		for (errs = 0; *argv != NULL; ++argv)
			if (checkname(*argv, typelist) != 0)
				errs = 1;
		break;
	}
	exit(errs);
}

int
umountall(char **typelist)
{
	struct xvfsconf vfc;
	struct fstab *fs;
	int rval;
	char *cp;
	static int firstcall = 1;

	if ((fs = getfsent()) != NULL)
		firstcall = 0;
	else if (firstcall)
		errx(1, "fstab reading failure");
	else
		return (0);
	do {
		/* Ignore the root. */
		if (strcmp(fs->fs_file, "/") == 0)
			continue;
		/*
		 * !!!
		 * Historic practice: ignore unknown FSTAB_* fields.
		 */
		if (strcmp(fs->fs_type, FSTAB_RW) &&
		    strcmp(fs->fs_type, FSTAB_RO) &&
		    strcmp(fs->fs_type, FSTAB_RQ))
			continue;
		/* Ignore unknown file system types. */
		if (getvfsbyname(fs->fs_vfstype, &vfc) == -1)
			continue;
		if (checkvfsname(fs->fs_vfstype, typelist))
			continue;

		/*
		 * We want to unmount the file systems in the reverse order
		 * that they were mounted.  So, we save off the file name
		 * in some allocated memory, and then call recursively.
		 */
		if ((cp = malloc((size_t)strlen(fs->fs_file) + 1)) == NULL)
			err(1, "malloc failed");
		(void)strcpy(cp, fs->fs_file);
		rval = umountall(typelist);
		rval = checkname(cp, typelist) || rval;
		free(cp);
		return (rval);
	} while ((fs = getfsent()) != NULL);
	return (0);
}

/*
 * Do magic checks on mountpoint/device/fsid, and then call unmount(2).
 */
int
checkname(char *mntname, char **typelist)
{
	char buf[MAXPATHLEN];
	struct statfs sfsbuf;
	struct stat sb;
	struct statfs *sfs;
	char *delimp;
	dev_t dev;
	int len;

	/*
	 * 1. Check if the name exists in the mounttable.
	 */
	sfs = checkmntlist(mntname);
	/*
	 * 2. Remove trailing slashes if there are any. After that
	 * we look up the name in the mounttable again.
	 */
	if (sfs == NULL) {
		len = strlen(mntname);
		while (len > 1 && mntname[len - 1] == '/')
			mntname[--len] = '\0';
		sfs = checkmntlist(mntname);
	}
	/*
	 * 3. Check if the deprecated NFS syntax with an '@' has been used
	 * and translate it to the ':' syntax. Look up the name in the
	 * mount table again.
	 */
	if (sfs == NULL && (delimp = strrchr(mntname, '@')) != NULL) {
		snprintf(buf, sizeof(buf), "%s:%.*s", delimp + 1,
		    (int)(delimp - mntname), mntname);
		len = strlen(buf);
		while (len > 1 && buf[len - 1] == '/')
			buf[--len] = '\0';
		sfs = checkmntlist(buf);
	}
	/*
	 * 4. Resort to a statfs(2) call. This is the last check so that
	 * hung NFS filesystems for example can be unmounted without
	 * potentially blocking forever in statfs() as long as the
	 * filesystem is specified unambiguously. This covers all the
	 * hard cases such as symlinks and mismatches between the
	 * mount list and reality.
	 * We also do this if an ambiguous mount point was specified.
	 */
	if (sfs == NULL || (getmntentry(NULL, mntname, NULL, FIND) != NULL &&
	    getmntentry(NULL, mntname, NULL, CHECKUNIQUE) == NULL)) {
		if (statfs(mntname, &sfsbuf) != 0) {
			warn("%s: statfs", mntname);
		} else if (stat(mntname, &sb) != 0) {
			warn("%s: stat", mntname);
		} else if (S_ISDIR(sb.st_mode)) {
			/* Check that `mntname' is the root directory. */
			dev = sb.st_dev;
			snprintf(buf, sizeof(buf), "%s/..", mntname);
			if (stat(buf, &sb) != 0) {
				warn("%s: stat", buf);
			} else if (sb.st_dev == dev) {
				warnx("%s: not a file system root directory",
				    mntname);
				return (1);
			} else
				sfs = &sfsbuf;
		}
	}
	if (sfs == NULL) {
		warnx("%s: unknown file system", mntname);
		return (1);
	}
	if (checkvfsname(sfs->f_fstypename, typelist))
		return (1);
	return (umountfs(sfs));
}

/*
 * NFS stuff and unmount(2) call
 */
int
umountfs(struct statfs *sfs)
{
	char fsidbuf[64];
	enum clnt_stat clnt_stat;
	struct timeval try;
	struct addrinfo *ai, hints;
	int do_rpc;
	CLIENT *clp;
	char *nfsdirname, *orignfsdirname;
	char *hostp, *delimp;

	ai = NULL;
	do_rpc = 0;
	hostp = NULL;
	nfsdirname = delimp = orignfsdirname = NULL;
	memset(&hints, 0, sizeof hints);

	if (strcmp(sfs->f_fstypename, "nfs") == 0) {
		if ((nfsdirname = strdup(sfs->f_mntfromname)) == NULL)
			err(1, "strdup");
		orignfsdirname = nfsdirname;
		if (*nfsdirname == '[' &&
		    (delimp = strchr(nfsdirname + 1, ']')) != NULL &&
		    *(delimp + 1) == ':') {
			hostp = nfsdirname + 1;
			nfsdirname = delimp + 2;
		} else if ((delimp = strrchr(nfsdirname, ':')) != NULL) {
			hostp = nfsdirname;
			nfsdirname = delimp + 1;
		}
		if (hostp != NULL) {
			*delimp = '\0';
			getaddrinfo(hostp, NULL, &hints, &ai);
			if (ai == NULL) {
				warnx("can't get net id for host");
			}
		}

		/*
		 * Check if we have to start the rpc-call later.
		 * If there are still identical nfs-names mounted,
		 * we skip the rpc-call. Obviously this has to
		 * happen before unmount(2), but it should happen
		 * after the previous namecheck.
		 * A non-NULL return means that this is the last
		 * mount from mntfromname that is still mounted.
		 */
		if (getmntentry(sfs->f_mntfromname, NULL, NULL,
		    CHECKUNIQUE) != NULL)
			do_rpc = 1;
	}

	if (!namematch(ai))
		return (1);
	/* First try to unmount using the file system ID. */
	snprintf(fsidbuf, sizeof(fsidbuf), "FSID:%d:%d", sfs->f_fsid.val[0],
	    sfs->f_fsid.val[1]);
	if (unmount(fsidbuf, fflag | MNT_BYFSID) != 0) {
		/* XXX, non-root users get a zero fsid, so don't warn. */
		if (errno != ENOENT || sfs->f_fsid.val[0] != 0 ||
		    sfs->f_fsid.val[1] != 0)
			warn("unmount of %s failed", sfs->f_mntonname);
		if (errno != ENOENT)
			return (1);
		/* Compatibility for old kernels. */
		if (sfs->f_fsid.val[0] != 0 || sfs->f_fsid.val[1] != 0)
			warnx("retrying using path instead of file system ID");
		if (unmount(sfs->f_mntonname, fflag) != 0) {
			warn("unmount of %s failed", sfs->f_mntonname);
			return (1);
		}
	}
	/* Mark this this file system as unmounted. */
	getmntentry(NULL, NULL, &sfs->f_fsid, REMOVE);
	if (vflag)
		(void)printf("%s: unmount from %s\n", sfs->f_mntfromname,
		    sfs->f_mntonname);
	/*
	 * Report to mountd-server which nfsname
	 * has been unmounted.
	 */
	if (ai != NULL && !(fflag & MNT_FORCE) && do_rpc) {
		clp = clnt_create(hostp, MOUNTPROG, MOUNTVERS, "udp");
		if (clp  == NULL) {
			warnx("%s: %s", hostp,
			    clnt_spcreateerror("MOUNTPROG"));
			return (1);
		}
		clp->cl_auth = authsys_create_default();
		try.tv_sec = 20;
		try.tv_usec = 0;
		clnt_stat = clnt_call(clp, MOUNTPROC_UMNT, (xdrproc_t)xdr_dir,
		    nfsdirname, (xdrproc_t)xdr_void, (caddr_t)0, try);
		if (clnt_stat != RPC_SUCCESS) {
			warnx("%s: %s", hostp,
			    clnt_sperror(clp, "RPCMNT_UMOUNT"));
			return (1);
		}
		/*
		 * Remove the unmounted entry from /var/db/mounttab.
		 */
		if (read_mtab()) {
			clean_mtab(hostp, nfsdirname, vflag);
			if(!write_mtab(vflag))
				warnx("cannot remove mounttab entry %s:%s",
				    hostp, nfsdirname);
			free_mtab();
		}
		free(orignfsdirname);
		auth_destroy(clp->cl_auth);
		clnt_destroy(clp);
	}
	return (0);
}

struct statfs *
getmntentry(const char *fromname, const char *onname, fsid_t *fsid, dowhat what)
{
	static struct statfs *mntbuf;
	static size_t mntsize = 0;
	static char *mntcheck = NULL;
	struct statfs *sfs, *foundsfs;
	int i, count;

	if (mntsize <= 0) {
		if ((mntsize = mntinfo(&mntbuf)) <= 0)
			return (NULL);
	}
	if (mntcheck == NULL) {
		if ((mntcheck = calloc(mntsize + 1, sizeof(int))) == NULL)
			err(1, "calloc");
	}
	/*
	 * We want to get the file systems in the reverse order
	 * that they were mounted. Unmounted file systems are marked
	 * in a table called 'mntcheck'.
	 */
	count = 0;
	foundsfs = NULL;
	for (i = mntsize - 1; i >= 0; i--) {
		if (mntcheck[i])
			continue;
		sfs = &mntbuf[i];
		if (fromname != NULL && strcmp(sfs->f_mntfromname,
		    fromname) != 0)
			continue;
		if (onname != NULL && strcmp(sfs->f_mntonname, onname) != 0)
			continue;
		if (fsid != NULL && bcmp(&sfs->f_fsid, fsid,
		    sizeof(*fsid)) != 0)
			continue;

		switch (what) {
		case CHECKUNIQUE:
			foundsfs = sfs;
			count++;
			continue;
		case REMOVE:
			mntcheck[i] = 1;
			break;
		default:
			break;
		}
		return (sfs);
	}

	if (what == CHECKUNIQUE && count == 1)
		return (foundsfs);
	return (NULL);
}

int
sacmp(void *sa1, void *sa2)
{
	void *p1, *p2;
	int len;

	if (((struct sockaddr *)sa1)->sa_family !=
	    ((struct sockaddr *)sa2)->sa_family)
		return (1);

	switch (((struct sockaddr *)sa1)->sa_family) {
	case AF_INET:
		p1 = &((struct sockaddr_in *)sa1)->sin_addr;
		p2 = &((struct sockaddr_in *)sa2)->sin_addr;
		len = 4;
		break;
	case AF_INET6:
		p1 = &((struct sockaddr_in6 *)sa1)->sin6_addr;
		p2 = &((struct sockaddr_in6 *)sa2)->sin6_addr;
		len = 16;
		if (((struct sockaddr_in6 *)sa1)->sin6_scope_id !=
		    ((struct sockaddr_in6 *)sa2)->sin6_scope_id)
			return (1);
		break;
	default:
		return (1);
	}

	return memcmp(p1, p2, len);
}

int
namematch(struct addrinfo *ai)
{
	struct addrinfo *aip;

	if (nfshost == NULL || nfshost_ai == NULL)
		return (1);

	while (ai != NULL) {
		aip = nfshost_ai;
		while (aip != NULL) {
			if (sacmp(ai->ai_addr, aip->ai_addr) == 0)
				return (1);
			aip = aip->ai_next;
		}
		ai = ai->ai_next;
	}

	return (0);
}

struct statfs *
checkmntlist(char *mntname)
{
	struct statfs *sfs;
	fsid_t fsid;

	sfs = NULL;
	if (parsehexfsid(mntname, &fsid) == 0)
		sfs = getmntentry(NULL, NULL, &fsid, FIND);
	if (sfs == NULL)
		sfs = getmntentry(NULL, mntname, NULL, FIND);
	if (sfs == NULL)
		sfs = getmntentry(mntname, NULL, NULL, FIND);
	return (sfs);
}

size_t
mntinfo(struct statfs **mntbuf)
{
	static struct statfs *origbuf;
	size_t bufsize;
	int mntsize;

	mntsize = getfsstat(NULL, 0, MNT_NOWAIT);
	if (mntsize <= 0)
		return (0);
	bufsize = (mntsize + 1) * sizeof(struct statfs);
	if ((origbuf = malloc(bufsize)) == NULL)
		err(1, "malloc");
	mntsize = getfsstat(origbuf, (long)bufsize, MNT_NOWAIT);
	*mntbuf = origbuf;
	return (mntsize);
}

/*
 * Convert a hexadecimal filesystem ID to an fsid_t.
 * Returns 0 on success.
 */
int
parsehexfsid(const char *hex, fsid_t *fsid)
{
	char hexbuf[3];
	int i;

	if (strlen(hex) != sizeof(*fsid) * 2)
		return (-1);
	hexbuf[2] = '\0';
	for (i = 0; i < (int)sizeof(*fsid); i++) {
		hexbuf[0] = hex[i * 2];
		hexbuf[1] = hex[i * 2 + 1];
		if (!isxdigit(hexbuf[0]) || !isxdigit(hexbuf[1]))
			return (-1);
		((u_char *)fsid)[i] = strtol(hexbuf, NULL, 16);
	}
	return (0);
}

/*
 * xdr routines for mount rpc's
 */
int
xdr_dir(XDR *xdrsp, char *dirp)
{

	return (xdr_string(xdrsp, &dirp, MNTPATHLEN));
}

void
usage(void)
{

	(void)fprintf(stderr, "%s\n%s\n",
	    "usage: umount [-fv] special ... | node ... | fsid ...",
	    "       umount -a | -A [-F fstab] [-fv] [-h host] [-t type]");
	exit(1);
}
OpenPOWER on IntegriCloud