xref: /freebsd/sbin/umount/umount.c (revision 7f9d26bd9d1b2754da8429257edbde0a8237f84f)
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  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 static const char copyright[] =
36 "@(#) Copyright (c) 1980, 1989, 1993\n\
37 	The Regents of the University of California.  All rights reserved.\n";
38 #endif /* not lint */
39 
40 #ifndef lint
41 #if 0
42 static char sccsid[] = "@(#)umount.c	8.8 (Berkeley) 5/8/95";
43 #endif
44 static const char rcsid[] =
45   "$FreeBSD$";
46 #endif /* not lint */
47 
48 #include <sys/param.h>
49 #include <sys/mount.h>
50 
51 #include <netdb.h>
52 #include <rpc/rpc.h>
53 #include <nfs/rpcv2.h>
54 
55 #include <err.h>
56 #include <fstab.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <unistd.h>
61 
62 #define ISDOT(x)	((x)[0] == '.' && (x)[1] == '\0')
63 #define ISDOTDOT(x)	((x)[0] == '.' && (x)[1] == '.' && (x)[2] == '\0')
64 
65 typedef enum { MNTON, MNTFROM, NOTHING } mntwhat;
66 typedef enum { MARK, UNMARK, NAME, COUNT, FREE } dowhat;
67 
68 int	fflag, vflag;
69 char   *nfshost;
70 
71 void	 checkmntlist (char *, char **, char **, char **);
72 int	 checkvfsname (const char *, char **);
73 char	*getmntname (const char *, const char *,
74 	 mntwhat, char **, dowhat);
75 char 	*getrealname(char *, char *resolved_path);
76 char   **makevfslist (const char *);
77 size_t	 mntinfo (struct statfs **);
78 int	 namematch (struct hostent *);
79 int	 selected (int);
80 int	 umountall (char **);
81 int	 umountfs (char *, char **);
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;
89 	char **typelist = NULL, *mntonname, *mntfromname;
90 	char *type, *mntfromnamerev, *mntonnamerev;
91 	struct statfs *mntbuf;
92 
93 	/* Start disks transferring immediately. */
94 	sync();
95 
96 	all = errs = 0;
97 	while ((ch = getopt(argc, argv, "Aafh:t:v")) != -1)
98 		switch (ch) {
99 		case 'A':
100 			all = 2;
101 			break;
102 		case 'a':
103 			all = 1;
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 't':
113 			if (typelist != NULL)
114 				err(1, "only one -t option may be specified");
115 			typelist = makevfslist(optarg);
116 			break;
117 		case 'v':
118 			vflag = 1;
119 			break;
120 		default:
121 			usage();
122 			/* NOTREACHED */
123 		}
124 	argc -= optind;
125 	argv += optind;
126 
127 	if ((argc == 0 && !all) || (argc != 0 && all))
128 		usage();
129 
130 	/* -h implies "-t nfs" if no -t flag. */
131 	if ((nfshost != NULL) && (typelist == NULL))
132 		typelist = makevfslist("nfs");
133 
134 	switch (all) {
135 	case 2:
136 		if ((mntsize = mntinfo(&mntbuf)) <= 0)
137 			break;
138 		/*
139 		 * We unmount the nfs-mounts in the reverse order
140 		 * that they were mounted.
141 		 */
142 		for (errs = 0, mntsize--; mntsize > 0; mntsize--) {
143 			if (checkvfsname(mntbuf[mntsize].f_fstypename,
144 			    typelist))
145 				continue;
146 			/*
147 			 * Check if a mountpoint is laid over by another mount.
148 			 * A warning will be printed to stderr if this is
149 			 * the case. The laid over mount remains unmounted.
150 			 */
151 			mntonname = mntbuf[mntsize].f_mntonname;
152 			mntfromname = mntbuf[mntsize].f_mntfromname;
153 			mntonnamerev = getmntname(getmntname(mntonname,
154 			    NULL, MNTFROM, &type, NAME), NULL,
155 			    MNTON, &type, NAME);
156 
157 			mntfromnamerev = getmntname(mntonnamerev,
158 			    NULL, MNTFROM, &type, NAME);
159 
160 			if (strcmp(mntonnamerev, mntonname) == 0 &&
161 			    strcmp(mntfromnamerev, mntfromname ) != 0)
162 				warnx("cannot umount %s, %s\n        "
163 				    "is mounted there, umount it first",
164 				    mntonname, mntfromnamerev);
165 
166 			if (umountfs(mntbuf[mntsize].f_mntonname,
167 			    typelist) != 0)
168 				errs = 1;
169 		}
170 		free(mntbuf);
171 		break;
172 	case 1:
173 		if (setfsent() == 0)
174 			err(1, "%s", _PATH_FSTAB);
175 		errs = umountall(typelist);
176 		break;
177 	case 0:
178 		for (errs = 0; *argv != NULL; ++argv)
179 			if (umountfs(*argv, typelist) != 0)
180 				errs = 1;
181 		break;
182 	}
183 	(void)getmntname(NULL, NULL, NOTHING, NULL, FREE);
184 	exit(errs);
185 }
186 
187 int
188 umountall(char **typelist)
189 {
190 	struct vfsconf vfc;
191 	struct fstab *fs;
192 	int rval;
193 	char *cp;
194 	static int firstcall = 1;
195 
196 	if ((fs = getfsent()) != NULL)
197 		firstcall = 0;
198 	else if (firstcall)
199 		errx(1, "fstab reading failure");
200 	else
201 		return (0);
202 	do {
203 		/* Ignore the root. */
204 		if (strcmp(fs->fs_file, "/") == 0)
205 			continue;
206 		/*
207 		 * !!!
208 		 * Historic practice: ignore unknown FSTAB_* fields.
209 		 */
210 		if (strcmp(fs->fs_type, FSTAB_RW) &&
211 		    strcmp(fs->fs_type, FSTAB_RO) &&
212 		    strcmp(fs->fs_type, FSTAB_RQ))
213 			continue;
214 		/* If an unknown file system type, complain. */
215 		if (getvfsbyname(fs->fs_vfstype, &vfc) == -1) {
216 			warnx("%s: unknown mount type", fs->fs_vfstype);
217 			continue;
218 		}
219 		if (checkvfsname(fs->fs_vfstype, typelist))
220 			continue;
221 
222 		/*
223 		 * We want to unmount the file systems in the reverse order
224 		 * that they were mounted.  So, we save off the file name
225 		 * in some allocated memory, and then call recursively.
226 		 */
227 		if ((cp = malloc((size_t)strlen(fs->fs_file) + 1)) == NULL)
228 			err(1, "malloc failed");
229 		(void)strcpy(cp, fs->fs_file);
230 		rval = umountall(typelist);
231 		rval = umountfs(cp, typelist) || rval;
232 		free(cp);
233 		return (rval);
234 	} while ((fs = getfsent()) != NULL);
235 	return (0);
236 }
237 
238 int
239 umountfs(char *name, char **typelist)
240 {
241 	enum clnt_stat clnt_stat;
242 	struct hostent *hp;
243 	struct sockaddr_in saddr;
244 	struct timeval pertry, try;
245 	CLIENT *clp;
246 	size_t len;
247 	int so, speclen, do_rpc;
248 	char *mntonname, *mntfromname;
249 	char *mntfromnamerev;
250 	char *nfsdirname, *orignfsdirname;
251 	char *resolved, realname[MAXPATHLEN];
252 	char *type, *delimp, *hostp, *origname;
253 
254 	len = 0;
255 	mntfromname = mntonname = delimp = hostp = orignfsdirname = NULL;
256 
257 	/*
258 	 * 1. Check if the name exists in the mounttable.
259 	 */
260 	(void)checkmntlist(name, &mntfromname, &mntonname, &type);
261 	/*
262 	 * 2. Remove trailing slashes if there are any. After that
263 	 * we look up the name in the mounttable again.
264 	 */
265 	if (mntfromname == NULL && mntonname == NULL) {
266 		speclen = strlen(name);
267 		for (speclen = strlen(name);
268 		    speclen > 1 && name[speclen - 1] == '/';
269 		    speclen--)
270 			name[speclen - 1] = '\0';
271 		(void)checkmntlist(name, &mntfromname, &mntonname, &type);
272 		resolved = name;
273 		/* Save off original name in origname */
274 		if ((origname = strdup(name)) == NULL)
275 			err(1, "strdup");
276 		/*
277 		 * 3. Check if the deprecated nfs-syntax with an '@'
278 		 * has been used and translate it to the ':' syntax.
279 		 * Look up the name in the mounttable again.
280 		 */
281 		if (mntfromname == NULL && mntonname == NULL) {
282 			if ((delimp = strrchr(name, '@')) != NULL) {
283 				hostp = delimp + 1;
284 				if (*hostp != '\0') {
285 					/*
286 					 * Make both '@' and ':'
287 					 * notations equal
288 					 */
289 					char *host = strdup(hostp);
290 					len = strlen(hostp);
291 					if (host == NULL)
292 						err(1, "strdup");
293 					memmove(name + len + 1, name,
294 					    (size_t)(delimp - name));
295 					name[len] = ':';
296 					memmove(name, host, len);
297 					free(host);
298 				}
299 				for (speclen = strlen(name);
300 				    speclen > 1 && name[speclen - 1] == '/';
301 				    speclen--)
302 					name[speclen - 1] = '\0';
303 				name[len + speclen + 1] = '\0';
304 				(void)checkmntlist(name, &mntfromname,
305 				    &mntonname, &type);
306 				resolved = name;
307 			}
308 			/*
309 			 * 4. Check if a relative mountpoint has been
310 			 * specified. This should happen as last check,
311 			 * the order is important. To prevent possible
312 			 * nfs-hangs, we just call realpath(3) on the
313 			 * basedir of mountpoint and add the dirname again.
314 			 * Check the name in mounttable one last time.
315 			 */
316 			if (mntfromname == NULL && mntonname == NULL) {
317 				(void)strcpy(name, origname);
318 				if ((getrealname(name, realname)) != NULL) {
319 					(void)checkmntlist(realname,
320 					    &mntfromname, &mntonname, &type);
321 					resolved = realname;
322 				}
323 				/*
324 				 * All tests failed, return to main()
325 				 */
326 				if (mntfromname == NULL && mntonname == NULL) {
327 					(void)strcpy(name, origname);
328 					warnx("%s: not currently mounted",
329 					    origname);
330 					free(origname);
331 					return (1);
332 				}
333 			}
334 		}
335 		free(origname);
336 	} else
337 		resolved = name;
338 
339 	if (checkvfsname(type, typelist))
340 		return (1);
341 
342 	hp = NULL;
343 	nfsdirname = NULL;
344 	if (!strcmp(type, "nfs")) {
345 		if ((nfsdirname = strdup(mntfromname)) == NULL)
346 			err(1, "strdup");
347 		orignfsdirname = nfsdirname;
348 		if ((delimp = strchr(nfsdirname, ':')) != NULL) {
349 			*delimp = '\0';
350 			hostp = nfsdirname;
351 			if ((hp = gethostbyname(hostp)) == NULL) {
352 				warnx("can't get net id for host");
353 			}
354 			nfsdirname = delimp + 1;
355 		}
356 	}
357 	/*
358 	 * Check if the reverse entrys of the mounttable are really the
359 	 * same as the normal ones.
360 	 */
361 	if ((mntfromnamerev = strdup(getmntname(getmntname(mntfromname,
362 	    NULL, MNTON, &type, NAME), NULL, MNTFROM, &type, NAME))) == NULL)
363 		err(1, "strdup");
364 	/*
365 	 * Mark the uppermost mount as unmounted.
366 	 */
367 	(void)getmntname(mntfromname, mntonname, NOTHING, &type, MARK);
368 	/*
369 	 * If several equal mounts are in the mounttable, check the order
370 	 * and warn the user if necessary.
371 	 */
372 	if (strcmp(mntfromnamerev, mntfromname ) != 0 &&
373 	    strcmp(resolved, mntonname) != 0) {
374 		warnx("cannot umount %s, %s\n        "
375 		    "is mounted there, umount it first",
376 		    mntonname, mntfromnamerev);
377 
378 		/* call getmntname again to set mntcheck[i] to 0 */
379 		(void)getmntname(mntfromname, mntonname,
380 		    NOTHING, &type, UNMARK);
381 		return (1);
382 	}
383 	free(mntfromnamerev);
384 	/*
385 	 * Check if we have to start the rpc-call later.
386 	 * If there are still identical nfs-names mounted,
387 	 * we skip the rpc-call. Obviously this has to
388 	 * happen before unmount(2), but it should happen
389 	 * after the previous namecheck.
390 	 */
391 	if (strcmp(type, "nfs") == 0 && getmntname(mntfromname, NULL, NOTHING,
392 	    &type, COUNT) != NULL)
393 		do_rpc = 1;
394 	else
395 		do_rpc = 0;
396 	if (!namematch(hp))
397 		return (1);
398 	if (unmount(mntonname, fflag) != 0 ) {
399 		warn("unmount of %s failed", mntonname);
400 		return (1);
401 	}
402 	if (vflag)
403 		(void)printf("%s: unmount from %s\n", mntfromname, mntonname);
404 	/*
405 	 * Report to mountd-server which nfsname
406 	 * has been unmounted.
407 	 */
408 	if (hp != NULL && !(fflag & MNT_FORCE) && do_rpc) {
409 		memset(&saddr, 0, sizeof(saddr));
410 		saddr.sin_family = AF_INET;
411 		saddr.sin_port = 0;
412 		memmove(&saddr.sin_addr, hp->h_addr,
413 		    MIN(hp->h_length, sizeof(saddr.sin_addr)));
414 		pertry.tv_sec = 3;
415 		pertry.tv_usec = 0;
416 		so = RPC_ANYSOCK;
417 		if ((clp = clntudp_create(&saddr,
418 		    RPCPROG_MNT, RPCMNT_VER1, pertry, &so)) == NULL) {
419 			clnt_pcreateerror("Cannot MNT PRC");
420 			return (1);
421 		}
422 		clp->cl_auth = authunix_create_default();
423 		try.tv_sec = 20;
424 		try.tv_usec = 0;
425 		clnt_stat = clnt_call(clp, RPCMNT_UMOUNT, xdr_dir,
426 		    nfsdirname, xdr_void, (caddr_t)0, try);
427 		if (clnt_stat != RPC_SUCCESS) {
428 			clnt_perror(clp, "Bad MNT RPC");
429 			return (1);
430 		}
431 		free(orignfsdirname);
432 		auth_destroy(clp->cl_auth);
433 		clnt_destroy(clp);
434 	}
435 	return (0);
436 }
437 
438 char *
439 getmntname(const char *fromname, const char *onname,
440     mntwhat what, char **type, dowhat mark)
441 {
442 	static struct statfs *mntbuf;
443 	static size_t mntsize = 0;
444 	static char *mntcheck = NULL;
445 	static char *mntcount = NULL;
446 	int i, count;
447 
448 	if (mntsize <= 0) {
449 		if ((mntsize = mntinfo(&mntbuf)) <= 0)
450 			return (NULL);
451 	}
452 	if (mntcheck == NULL) {
453 		if ((mntcheck = calloc(mntsize + 1, sizeof(int))) == NULL ||
454 		    (mntcount = calloc(mntsize + 1, sizeof(int))) == NULL)
455 			err(1, "calloc");
456 	}
457 	/*
458 	 * We want to get the file systems in the reverse order
459 	 * that they were mounted. Mounted and unmounted filesystems
460 	 * are marked or unmarked in a table called 'mntcheck'.
461 	 * Unmount(const char *dir, int flags) does only take the
462 	 * mountpoint as argument, not the destination. If we don't pay
463 	 * attention to the order, it can happen that a overlaying
464 	 * filesystem get's unmounted instead of the one the user
465 	 * has choosen.
466 	 */
467 	switch (mark) {
468 	case NAME:
469 		/* Return only the specific name */
470 		for (i = mntsize - 1; i >= 0; i--) {
471 			if (fromname != NULL && what == MNTON &&
472 			    !strcmp(mntbuf[i].f_mntfromname, fromname) &&
473 			    mntcheck[i] != 1) {
474 				if (type)
475 					*type = mntbuf[i].f_fstypename;
476 				return (mntbuf[i].f_mntonname);
477 			}
478 			if (fromname != NULL && what == MNTFROM &&
479 			    !strcmp(mntbuf[i].f_mntonname, fromname) &&
480 			    mntcheck[i] != 1) {
481 				if (type)
482 					*type = mntbuf[i].f_fstypename;
483 				return (mntbuf[i].f_mntfromname);
484 			}
485 		}
486 		return (NULL);
487 	case MARK:
488 		/* Mark current mount with '1' and return name */
489 		for (i = mntsize - 1; i >= 0; i--) {
490 			if (mntcheck[i] == 0 &&
491 			    (strcmp(mntbuf[i].f_mntonname, onname) == 0) &&
492 			    (strcmp(mntbuf[i].f_mntfromname, fromname) == 0)) {
493 				mntcheck[i] = 1;
494 				return (mntbuf[i].f_mntonname);
495 			}
496 		}
497 		return (NULL);
498 	case UNMARK:
499 		/* Unmark current mount with '0' and return name */
500 		for (i = 0; i < mntsize; i++) {
501 			if (mntcheck[i] == 1 &&
502 			    (strcmp(mntbuf[i].f_mntonname, onname) == 0) &&
503 			    (strcmp(mntbuf[i].f_mntfromname, fromname) == 0)) {
504 				mntcheck[i] = 0;
505 				return (mntbuf[i].f_mntonname);
506 			}
507 		}
508 		return (NULL);
509 	case COUNT:
510 		/* Count the equal mntfromnames */
511 		count = 0;
512 		for (i = mntsize - 1; i >= 0; i--) {
513 			if (strcmp(mntbuf[i].f_mntfromname, fromname) == 0)
514 				count++;
515 		}
516 		/* Mark the already unmounted mounts and return
517 		 * mntfromname if count <= 1. Else return NULL.
518 		 */
519 		for (i = mntsize - 1; i >= 0; i--) {
520 			if (strcmp(mntbuf[i].f_mntfromname, fromname) == 0) {
521 				if (mntcount[i] == 1)
522 					count--;
523 				else {
524 					mntcount[i] = 1;
525 					break;
526 				}
527 			}
528 		}
529 		if (count <= 1)
530 			return (mntbuf[i].f_mntonname);
531 		else
532 			return (NULL);
533 	case FREE:
534 		free(mntbuf);
535 		free(mntcheck);
536 		return (NULL);
537 	default:
538 		return (NULL);
539 	}
540 }
541 
542 int
543 namematch(struct hostent *hp)
544 {
545 	char *cp, **np;
546 
547 	if ((hp == NULL) || (nfshost == NULL))
548 		return (1);
549 
550 	if (strcasecmp(nfshost, hp->h_name) == 0)
551 		return (1);
552 
553 	if ((cp = strchr(hp->h_name, '.')) != NULL) {
554 		*cp = '\0';
555 		if (strcasecmp(nfshost, hp->h_name) == 0)
556 			return (1);
557 	}
558 	for (np = hp->h_aliases; *np; np++) {
559 		if (strcasecmp(nfshost, *np) == 0)
560 			return (1);
561 		if ((cp = strchr(*np, '.')) != NULL) {
562 			*cp = '\0';
563 			if (strcasecmp(nfshost, *np) == 0)
564 				return (1);
565 		}
566 	}
567 	return (0);
568 }
569 
570 void
571 checkmntlist(char *name, char **fromname, char **onname, char **type)
572 {
573 
574 	*fromname = getmntname(name, NULL, MNTFROM, type, NAME);
575 	if (*fromname == NULL) {
576 		*onname = getmntname(name, NULL, MNTON, type, NAME);
577 		if (*onname != NULL)
578 			*fromname = name;
579 	} else
580 		*onname = name;
581 }
582 
583 size_t
584 mntinfo(struct statfs **mntbuf)
585 {
586 	static struct statfs *origbuf;
587 	size_t bufsize;
588 	int mntsize;
589 
590 	mntsize = getfsstat(NULL, 0l, MNT_NOWAIT);
591 	if (mntsize <= 0)
592 		return (0);
593 	bufsize = (mntsize + 1) * sizeof(struct statfs);
594 	if ((origbuf = malloc(bufsize)) == NULL)
595 		err(1, "malloc");
596 	mntsize = getfsstat(origbuf, (long)bufsize, MNT_NOWAIT);
597 	*mntbuf = origbuf;
598 	return (mntsize);
599 }
600 
601 char *
602 getrealname(char *name, char *realname)
603 {
604 	char *dirname;
605 	int havedir;
606 	size_t baselen;
607 	size_t dirlen;
608 
609 	dirname = '\0';
610 	havedir = 0;
611 	if (*name == '/') {
612 		if (ISDOT(name + 1) || ISDOTDOT(name + 1))
613 			strcpy(realname, "/");
614 		else {
615 			if ((dirname = strrchr(name + 1, '/')) == NULL)
616 				snprintf(realname, MAXPATHLEN, "%s", name);
617 			else
618 				havedir = 1;
619 		}
620 	} else {
621 		if (ISDOT(name) || ISDOTDOT(name))
622 			(void)realpath(name, realname);
623 		else {
624 			if ((dirname = strrchr(name, '/')) == NULL) {
625 				if ((realpath(name, realname)) == NULL)
626 					return (NULL);
627 			} else
628 				havedir = 1;
629 		}
630 	}
631 	if (havedir) {
632 		*dirname++ = '\0';
633 		if (ISDOT(dirname)) {
634 			*dirname = '\0';
635 			if ((realpath(name, realname)) == NULL)
636 				return (NULL);
637 		} else if (ISDOTDOT(dirname)) {
638 			*--dirname = '/';
639 			if ((realpath(name, realname)) == NULL)
640 				return (NULL);
641 		} else {
642 			if ((realpath(name, realname)) == NULL)
643 				return (NULL);
644 			baselen = strlen(realname);
645 			dirlen = strlen(dirname);
646 			if (baselen + dirlen + 1 > MAXPATHLEN)
647 				return (NULL);
648 			if (realname[1] == '\0') {
649 				memmove(realname + 1, dirname, dirlen);
650 				realname[dirlen + 1] = '\0';
651 			} else {
652 				realname[baselen] = '/';
653 				memmove(realname + baselen + 1,
654 				    dirname, dirlen);
655 				realname[baselen + dirlen + 1] = '\0';
656 			}
657 		}
658 	}
659 	return (realname);
660 }
661 
662 /*
663  * xdr routines for mount rpc's
664  */
665 int
666 xdr_dir(XDR *xdrsp, char *dirp)
667 {
668 
669 	return (xdr_string(xdrsp, &dirp, RPCMNT_PATHLEN));
670 }
671 
672 void
673 usage()
674 {
675 
676 	(void)fprintf(stderr, "%s\n%s\n",
677 	    "usage: umount [-fv] special | node",
678 	    "       umount -a | -A [-fv] [-h host] [-t type]");
679 	exit(1);
680 }
681