xref: /freebsd/sbin/umount/umount.c (revision 448897d366c218f9fd6208427eef1e6dd51f78d0)
1 /*-
2  * Copyright (c) 1980, 1989, 1993
3  *	The Regents of the University of California.  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 the
12  *    documentation and/or other materials provided with the distribution.
13  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #ifndef lint
31 static const char copyright[] =
32 "@(#) Copyright (c) 1980, 1989, 1993\n\
33 	The Regents of the University of California.  All rights reserved.\n";
34 #endif /* not lint */
35 
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)umount.c	8.8 (Berkeley) 5/8/95";
39 #endif
40 static const char rcsid[] =
41   "$FreeBSD$";
42 #endif /* not lint */
43 
44 #include <sys/param.h>
45 #include <sys/mount.h>
46 #include <sys/socket.h>
47 #include <sys/stat.h>
48 
49 #include <netdb.h>
50 #include <rpc/rpc.h>
51 #include <rpcsvc/mount.h>
52 
53 #include <ctype.h>
54 #include <err.h>
55 #include <errno.h>
56 #include <fstab.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <unistd.h>
61 
62 #include "mounttab.h"
63 
64 typedef enum { FIND, REMOVE, CHECKUNIQUE } dowhat;
65 
66 static struct addrinfo *nfshost_ai = NULL;
67 static int	fflag, vflag;
68 static char	*nfshost;
69 
70 struct statfs *checkmntlist(char *);
71 int	 checkvfsname (const char *, char **);
72 struct statfs *getmntentry(const char *fromname, const char *onname,
73 	     fsid_t *fsid, dowhat what);
74 char   **makevfslist (const char *);
75 size_t	 mntinfo (struct statfs **);
76 int	 namematch (struct addrinfo *);
77 int	 parsehexfsid(const char *hex, fsid_t *fsid);
78 int	 sacmp (void *, void *);
79 int	 umountall (char **);
80 int	 checkname (char *, char **);
81 int	 umountfs(struct statfs *sfs);
82 void	 usage (void);
83 int	 xdr_dir (XDR *, char *);
84 
85 int
86 main(int argc, char *argv[])
87 {
88 	int all, errs, ch, mntsize, error;
89 	char **typelist = NULL;
90 	struct statfs *mntbuf, *sfs;
91 	struct addrinfo hints;
92 
93 	all = errs = 0;
94 	while ((ch = getopt(argc, argv, "AaF:fh:nt:v")) != -1)
95 		switch (ch) {
96 		case 'A':
97 			all = 2;
98 			break;
99 		case 'a':
100 			all = 1;
101 			break;
102 		case 'F':
103 			setfstab(optarg);
104 			break;
105 		case 'f':
106 			fflag |= MNT_FORCE;
107 			break;
108 		case 'h':	/* -h implies -A. */
109 			all = 2;
110 			nfshost = optarg;
111 			break;
112 		case 'n':
113 			fflag |= MNT_NONBUSY;
114 			break;
115 		case 't':
116 			if (typelist != NULL)
117 				err(1, "only one -t option may be specified");
118 			typelist = makevfslist(optarg);
119 			break;
120 		case 'v':
121 			vflag = 1;
122 			break;
123 		default:
124 			usage();
125 			/* NOTREACHED */
126 		}
127 	argc -= optind;
128 	argv += optind;
129 
130 	if ((fflag & MNT_FORCE) != 0 && (fflag & MNT_NONBUSY) != 0)
131 		err(1, "-f and -n are mutually exclusive");
132 
133 	/* Start disks transferring immediately. */
134 	if ((fflag & (MNT_FORCE | MNT_NONBUSY)) == 0)
135 		sync();
136 
137 	if ((argc == 0 && !all) || (argc != 0 && all))
138 		usage();
139 
140 	/* -h implies "-t nfs" if no -t flag. */
141 	if ((nfshost != NULL) && (typelist == NULL))
142 		typelist = makevfslist("nfs");
143 
144 	if (nfshost != NULL) {
145 		memset(&hints, 0, sizeof hints);
146 		error = getaddrinfo(nfshost, NULL, &hints, &nfshost_ai);
147 		if (error)
148 			errx(1, "%s: %s", nfshost, gai_strerror(error));
149 	}
150 
151 	switch (all) {
152 	case 2:
153 		if ((mntsize = mntinfo(&mntbuf)) <= 0)
154 			break;
155 		/*
156 		 * We unmount the nfs-mounts in the reverse order
157 		 * that they were mounted.
158 		 */
159 		for (errs = 0, mntsize--; mntsize > 0; mntsize--) {
160 			sfs = &mntbuf[mntsize];
161 			if (checkvfsname(sfs->f_fstypename, typelist))
162 				continue;
163 			if (strcmp(sfs->f_mntonname, "/dev") == 0)
164 				continue;
165 			if (umountfs(sfs) != 0)
166 				errs = 1;
167 		}
168 		free(mntbuf);
169 		break;
170 	case 1:
171 		if (setfsent() == 0)
172 			err(1, "%s", getfstab());
173 		errs = umountall(typelist);
174 		break;
175 	case 0:
176 		for (errs = 0; *argv != NULL; ++argv)
177 			if (checkname(*argv, typelist) != 0)
178 				errs = 1;
179 		break;
180 	}
181 	exit(errs);
182 }
183 
184 int
185 umountall(char **typelist)
186 {
187 	struct xvfsconf vfc;
188 	struct fstab *fs;
189 	int rval;
190 	char *cp;
191 	static int firstcall = 1;
192 
193 	if ((fs = getfsent()) != NULL)
194 		firstcall = 0;
195 	else if (firstcall)
196 		errx(1, "fstab reading failure");
197 	else
198 		return (0);
199 	do {
200 		/* Ignore the root. */
201 		if (strcmp(fs->fs_file, "/") == 0)
202 			continue;
203 		/*
204 		 * !!!
205 		 * Historic practice: ignore unknown FSTAB_* fields.
206 		 */
207 		if (strcmp(fs->fs_type, FSTAB_RW) &&
208 		    strcmp(fs->fs_type, FSTAB_RO) &&
209 		    strcmp(fs->fs_type, FSTAB_RQ))
210 			continue;
211 		/* Ignore unknown file system types. */
212 		if (getvfsbyname(fs->fs_vfstype, &vfc) == -1)
213 			continue;
214 		if (checkvfsname(fs->fs_vfstype, typelist))
215 			continue;
216 
217 		/*
218 		 * We want to unmount the file systems in the reverse order
219 		 * that they were mounted.  So, we save off the file name
220 		 * in some allocated memory, and then call recursively.
221 		 */
222 		if ((cp = malloc((size_t)strlen(fs->fs_file) + 1)) == NULL)
223 			err(1, "malloc failed");
224 		(void)strcpy(cp, fs->fs_file);
225 		rval = umountall(typelist);
226 		rval = checkname(cp, typelist) || rval;
227 		free(cp);
228 		return (rval);
229 	} while ((fs = getfsent()) != NULL);
230 	return (0);
231 }
232 
233 /*
234  * Do magic checks on mountpoint/device/fsid, and then call unmount(2).
235  */
236 int
237 checkname(char *mntname, char **typelist)
238 {
239 	char buf[MAXPATHLEN];
240 	struct statfs sfsbuf;
241 	struct stat sb;
242 	struct statfs *sfs;
243 	char *delimp;
244 	dev_t dev;
245 	int len;
246 
247 	/*
248 	 * 1. Check if the name exists in the mounttable.
249 	 */
250 	sfs = checkmntlist(mntname);
251 	/*
252 	 * 2. Remove trailing slashes if there are any. After that
253 	 * we look up the name in the mounttable again.
254 	 */
255 	if (sfs == NULL) {
256 		len = strlen(mntname);
257 		while (len > 1 && mntname[len - 1] == '/')
258 			mntname[--len] = '\0';
259 		sfs = checkmntlist(mntname);
260 	}
261 	/*
262 	 * 3. Check if the deprecated NFS syntax with an '@' has been used
263 	 * and translate it to the ':' syntax. Look up the name in the
264 	 * mount table again.
265 	 */
266 	if (sfs == NULL && (delimp = strrchr(mntname, '@')) != NULL) {
267 		snprintf(buf, sizeof(buf), "%s:%.*s", delimp + 1,
268 		    (int)(delimp - mntname), mntname);
269 		len = strlen(buf);
270 		while (len > 1 && buf[len - 1] == '/')
271 			buf[--len] = '\0';
272 		sfs = checkmntlist(buf);
273 	}
274 	/*
275 	 * 4. Resort to a statfs(2) call. This is the last check so that
276 	 * hung NFS filesystems for example can be unmounted without
277 	 * potentially blocking forever in statfs() as long as the
278 	 * filesystem is specified unambiguously. This covers all the
279 	 * hard cases such as symlinks and mismatches between the
280 	 * mount list and reality.
281 	 * We also do this if an ambiguous mount point was specified.
282 	 */
283 	if (sfs == NULL || (getmntentry(NULL, mntname, NULL, FIND) != NULL &&
284 	    getmntentry(NULL, mntname, NULL, CHECKUNIQUE) == NULL)) {
285 		if (statfs(mntname, &sfsbuf) != 0) {
286 			warn("%s: statfs", mntname);
287 		} else if (stat(mntname, &sb) != 0) {
288 			warn("%s: stat", mntname);
289 		} else if (S_ISDIR(sb.st_mode)) {
290 			/* Check that `mntname' is the root directory. */
291 			dev = sb.st_dev;
292 			snprintf(buf, sizeof(buf), "%s/..", mntname);
293 			if (stat(buf, &sb) != 0) {
294 				warn("%s: stat", buf);
295 			} else if (sb.st_dev == dev) {
296 				warnx("%s: not a file system root directory",
297 				    mntname);
298 				return (1);
299 			} else
300 				sfs = &sfsbuf;
301 		}
302 	}
303 	if (sfs == NULL) {
304 		warnx("%s: unknown file system", mntname);
305 		return (1);
306 	}
307 	if (checkvfsname(sfs->f_fstypename, typelist))
308 		return (1);
309 	return (umountfs(sfs));
310 }
311 
312 /*
313  * NFS stuff and unmount(2) call
314  */
315 int
316 umountfs(struct statfs *sfs)
317 {
318 	char fsidbuf[64];
319 	enum clnt_stat clnt_stat;
320 	struct timeval try;
321 	struct addrinfo *ai, hints;
322 	int do_rpc;
323 	CLIENT *clp;
324 	char *nfsdirname, *orignfsdirname;
325 	char *hostp, *delimp;
326 
327 	ai = NULL;
328 	do_rpc = 0;
329 	hostp = NULL;
330 	nfsdirname = delimp = orignfsdirname = NULL;
331 	memset(&hints, 0, sizeof hints);
332 
333 	if (strcmp(sfs->f_fstypename, "nfs") == 0) {
334 		if ((nfsdirname = strdup(sfs->f_mntfromname)) == NULL)
335 			err(1, "strdup");
336 		orignfsdirname = nfsdirname;
337 		if (*nfsdirname == '[' &&
338 		    (delimp = strchr(nfsdirname + 1, ']')) != NULL &&
339 		    *(delimp + 1) == ':') {
340 			hostp = nfsdirname + 1;
341 			nfsdirname = delimp + 2;
342 		} else if ((delimp = strrchr(nfsdirname, ':')) != NULL) {
343 			hostp = nfsdirname;
344 			nfsdirname = delimp + 1;
345 		}
346 		if (hostp != NULL) {
347 			*delimp = '\0';
348 			getaddrinfo(hostp, NULL, &hints, &ai);
349 			if (ai == NULL) {
350 				warnx("can't get net id for host");
351 			}
352 		}
353 
354 		/*
355 		 * Check if we have to start the rpc-call later.
356 		 * If there are still identical nfs-names mounted,
357 		 * we skip the rpc-call. Obviously this has to
358 		 * happen before unmount(2), but it should happen
359 		 * after the previous namecheck.
360 		 * A non-NULL return means that this is the last
361 		 * mount from mntfromname that is still mounted.
362 		 */
363 		if (getmntentry(sfs->f_mntfromname, NULL, NULL,
364 		    CHECKUNIQUE) != NULL)
365 			do_rpc = 1;
366 	}
367 
368 	if (!namematch(ai)) {
369 		free(orignfsdirname);
370 		return (1);
371 	}
372 	/* First try to unmount using the file system ID. */
373 	snprintf(fsidbuf, sizeof(fsidbuf), "FSID:%d:%d", sfs->f_fsid.val[0],
374 	    sfs->f_fsid.val[1]);
375 	if (unmount(fsidbuf, fflag | MNT_BYFSID) != 0) {
376 		/* XXX, non-root users get a zero fsid, so don't warn. */
377 		if (errno != ENOENT || sfs->f_fsid.val[0] != 0 ||
378 		    sfs->f_fsid.val[1] != 0)
379 			warn("unmount of %s failed", sfs->f_mntonname);
380 		if (errno != ENOENT) {
381 			free(orignfsdirname);
382 			return (1);
383 		}
384 		/* Compatibility for old kernels. */
385 		if (sfs->f_fsid.val[0] != 0 || sfs->f_fsid.val[1] != 0)
386 			warnx("retrying using path instead of file system ID");
387 		if (unmount(sfs->f_mntonname, fflag) != 0) {
388 			warn("unmount of %s failed", sfs->f_mntonname);
389 			free(orignfsdirname);
390 			return (1);
391 		}
392 	}
393 	/* Mark this this file system as unmounted. */
394 	getmntentry(NULL, NULL, &sfs->f_fsid, REMOVE);
395 	if (vflag)
396 		(void)printf("%s: unmount from %s\n", sfs->f_mntfromname,
397 		    sfs->f_mntonname);
398 	/*
399 	 * Report to mountd-server which nfsname
400 	 * has been unmounted.
401 	 */
402 	if (ai != NULL && !(fflag & MNT_FORCE) && do_rpc) {
403 		clp = clnt_create(hostp, MOUNTPROG, MOUNTVERS3, "udp");
404 		if (clp  == NULL) {
405 			warnx("%s: %s", hostp,
406 			    clnt_spcreateerror("MOUNTPROG"));
407 			free(orignfsdirname);
408 			return (1);
409 		}
410 		clp->cl_auth = authsys_create_default();
411 		try.tv_sec = 20;
412 		try.tv_usec = 0;
413 		clnt_stat = clnt_call(clp, MOUNTPROC_UMNT, (xdrproc_t)xdr_dir,
414 		    nfsdirname, (xdrproc_t)xdr_void, (caddr_t)0, try);
415 		if (clnt_stat != RPC_SUCCESS) {
416 			warnx("%s: %s", hostp,
417 			    clnt_sperror(clp, "RPCMNT_UMOUNT"));
418 			free(orignfsdirname);
419 			return (1);
420 		}
421 		/*
422 		 * Remove the unmounted entry from /var/db/mounttab.
423 		 */
424 		if (read_mtab()) {
425 			clean_mtab(hostp, nfsdirname, vflag);
426 			if(!write_mtab(vflag))
427 				warnx("cannot remove mounttab entry %s:%s",
428 				    hostp, nfsdirname);
429 			free_mtab();
430 		}
431 		auth_destroy(clp->cl_auth);
432 		clnt_destroy(clp);
433 	}
434 	free(orignfsdirname);
435 	return (0);
436 }
437 
438 struct statfs *
439 getmntentry(const char *fromname, const char *onname, fsid_t *fsid, dowhat what)
440 {
441 	static struct statfs *mntbuf;
442 	static size_t mntsize = 0;
443 	static int *mntcheck = NULL;
444 	struct statfs *sfs, *foundsfs;
445 	int i, count;
446 
447 	if (mntsize <= 0) {
448 		if ((mntsize = mntinfo(&mntbuf)) <= 0)
449 			return (NULL);
450 	}
451 	if (mntcheck == NULL) {
452 		if ((mntcheck = calloc(mntsize + 1, sizeof(int))) == NULL)
453 			err(1, "calloc");
454 	}
455 	/*
456 	 * We want to get the file systems in the reverse order
457 	 * that they were mounted. Unmounted file systems are marked
458 	 * in a table called 'mntcheck'.
459 	 */
460 	count = 0;
461 	foundsfs = NULL;
462 	for (i = mntsize - 1; i >= 0; i--) {
463 		if (mntcheck[i])
464 			continue;
465 		sfs = &mntbuf[i];
466 		if (fromname != NULL && strcmp(sfs->f_mntfromname,
467 		    fromname) != 0)
468 			continue;
469 		if (onname != NULL && strcmp(sfs->f_mntonname, onname) != 0)
470 			continue;
471 		if (fsid != NULL && bcmp(&sfs->f_fsid, fsid,
472 		    sizeof(*fsid)) != 0)
473 			continue;
474 
475 		switch (what) {
476 		case CHECKUNIQUE:
477 			foundsfs = sfs;
478 			count++;
479 			continue;
480 		case REMOVE:
481 			mntcheck[i] = 1;
482 			break;
483 		default:
484 			break;
485 		}
486 		return (sfs);
487 	}
488 
489 	if (what == CHECKUNIQUE && count == 1)
490 		return (foundsfs);
491 	return (NULL);
492 }
493 
494 int
495 sacmp(void *sa1, void *sa2)
496 {
497 	void *p1, *p2;
498 	int len;
499 
500 	if (((struct sockaddr *)sa1)->sa_family !=
501 	    ((struct sockaddr *)sa2)->sa_family)
502 		return (1);
503 
504 	switch (((struct sockaddr *)sa1)->sa_family) {
505 	case AF_INET:
506 		p1 = &((struct sockaddr_in *)sa1)->sin_addr;
507 		p2 = &((struct sockaddr_in *)sa2)->sin_addr;
508 		len = 4;
509 		break;
510 	case AF_INET6:
511 		p1 = &((struct sockaddr_in6 *)sa1)->sin6_addr;
512 		p2 = &((struct sockaddr_in6 *)sa2)->sin6_addr;
513 		len = 16;
514 		if (((struct sockaddr_in6 *)sa1)->sin6_scope_id !=
515 		    ((struct sockaddr_in6 *)sa2)->sin6_scope_id)
516 			return (1);
517 		break;
518 	default:
519 		return (1);
520 	}
521 
522 	return memcmp(p1, p2, len);
523 }
524 
525 int
526 namematch(struct addrinfo *ai)
527 {
528 	struct addrinfo *aip;
529 
530 	if (nfshost == NULL || nfshost_ai == NULL)
531 		return (1);
532 
533 	while (ai != NULL) {
534 		aip = nfshost_ai;
535 		while (aip != NULL) {
536 			if (sacmp(ai->ai_addr, aip->ai_addr) == 0)
537 				return (1);
538 			aip = aip->ai_next;
539 		}
540 		ai = ai->ai_next;
541 	}
542 
543 	return (0);
544 }
545 
546 struct statfs *
547 checkmntlist(char *mntname)
548 {
549 	struct statfs *sfs;
550 	fsid_t fsid;
551 
552 	sfs = NULL;
553 	if (parsehexfsid(mntname, &fsid) == 0)
554 		sfs = getmntentry(NULL, NULL, &fsid, FIND);
555 	if (sfs == NULL)
556 		sfs = getmntentry(NULL, mntname, NULL, FIND);
557 	if (sfs == NULL)
558 		sfs = getmntentry(mntname, NULL, NULL, FIND);
559 	return (sfs);
560 }
561 
562 size_t
563 mntinfo(struct statfs **mntbuf)
564 {
565 	static struct statfs *origbuf;
566 	size_t bufsize;
567 	int mntsize;
568 
569 	mntsize = getfsstat(NULL, 0, MNT_NOWAIT);
570 	if (mntsize <= 0)
571 		return (0);
572 	bufsize = (mntsize + 1) * sizeof(struct statfs);
573 	if ((origbuf = malloc(bufsize)) == NULL)
574 		err(1, "malloc");
575 	mntsize = getfsstat(origbuf, (long)bufsize, MNT_NOWAIT);
576 	*mntbuf = origbuf;
577 	return (mntsize);
578 }
579 
580 /*
581  * Convert a hexadecimal filesystem ID to an fsid_t.
582  * Returns 0 on success.
583  */
584 int
585 parsehexfsid(const char *hex, fsid_t *fsid)
586 {
587 	char hexbuf[3];
588 	int i;
589 
590 	if (strlen(hex) != sizeof(*fsid) * 2)
591 		return (-1);
592 	hexbuf[2] = '\0';
593 	for (i = 0; i < (int)sizeof(*fsid); i++) {
594 		hexbuf[0] = hex[i * 2];
595 		hexbuf[1] = hex[i * 2 + 1];
596 		if (!isxdigit(hexbuf[0]) || !isxdigit(hexbuf[1]))
597 			return (-1);
598 		((u_char *)fsid)[i] = strtol(hexbuf, NULL, 16);
599 	}
600 	return (0);
601 }
602 
603 /*
604  * xdr routines for mount rpc's
605  */
606 int
607 xdr_dir(XDR *xdrsp, char *dirp)
608 {
609 
610 	return (xdr_string(xdrsp, &dirp, MNTPATHLEN));
611 }
612 
613 void
614 usage(void)
615 {
616 
617 	(void)fprintf(stderr, "%s\n%s\n",
618 	    "usage: umount [-fnv] special ... | node ... | fsid ...",
619 	    "       umount -a | -A [-F fstab] [-fnv] [-h host] [-t type]");
620 	exit(1);
621 }
622