xref: /freebsd/sbin/umount/umount.c (revision 1669d8afc64812c8d2d1d147ae1fd42ff441e1b1)
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 <nfs/rpcv2.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 struct  addrinfo *nfshost_ai = NULL;
67 int	fflag, vflag;
68 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 (struct sockaddr *, struct sockaddr *);
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 	/* Start disks transferring immediately. */
94 	sync();
95 
96 	all = errs = 0;
97 	while ((ch = getopt(argc, argv, "AaF:fh: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 			setfstab(optarg);
107 			break;
108 		case 'f':
109 			fflag = MNT_FORCE;
110 			break;
111 		case 'h':	/* -h implies -A. */
112 			all = 2;
113 			nfshost = optarg;
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 ((argc == 0 && !all) || (argc != 0 && all))
131 		usage();
132 
133 	/* -h implies "-t nfs" if no -t flag. */
134 	if ((nfshost != NULL) && (typelist == NULL))
135 		typelist = makevfslist("nfs");
136 
137 	if (nfshost != NULL) {
138 		memset(&hints, 0, sizeof hints);
139 		error = getaddrinfo(nfshost, NULL, &hints, &nfshost_ai);
140 		if (error)
141 			errx(1, "%s: %s", nfshost, gai_strerror(error));
142 	}
143 
144 	switch (all) {
145 	case 2:
146 		if ((mntsize = mntinfo(&mntbuf)) <= 0)
147 			break;
148 		/*
149 		 * We unmount the nfs-mounts in the reverse order
150 		 * that they were mounted.
151 		 */
152 		for (errs = 0, mntsize--; mntsize > 0; mntsize--) {
153 			sfs = &mntbuf[mntsize];
154 			if (checkvfsname(sfs->f_fstypename, typelist))
155 				continue;
156 			if (umountfs(sfs) != 0)
157 				errs = 1;
158 		}
159 		free(mntbuf);
160 		break;
161 	case 1:
162 		if (setfsent() == 0)
163 			err(1, "%s", getfstab());
164 		errs = umountall(typelist);
165 		break;
166 	case 0:
167 		for (errs = 0; *argv != NULL; ++argv)
168 			if (checkname(*argv, typelist) != 0)
169 				errs = 1;
170 		break;
171 	}
172 	exit(errs);
173 }
174 
175 int
176 umountall(char **typelist)
177 {
178 	struct xvfsconf vfc;
179 	struct fstab *fs;
180 	int rval;
181 	char *cp;
182 	static int firstcall = 1;
183 
184 	if ((fs = getfsent()) != NULL)
185 		firstcall = 0;
186 	else if (firstcall)
187 		errx(1, "fstab reading failure");
188 	else
189 		return (0);
190 	do {
191 		/* Ignore the root. */
192 		if (strcmp(fs->fs_file, "/") == 0)
193 			continue;
194 		/*
195 		 * !!!
196 		 * Historic practice: ignore unknown FSTAB_* fields.
197 		 */
198 		if (strcmp(fs->fs_type, FSTAB_RW) &&
199 		    strcmp(fs->fs_type, FSTAB_RO) &&
200 		    strcmp(fs->fs_type, FSTAB_RQ))
201 			continue;
202 		/* Ignore unknown file system types. */
203 		if (getvfsbyname(fs->fs_vfstype, &vfc) == -1)
204 			continue;
205 		if (checkvfsname(fs->fs_vfstype, typelist))
206 			continue;
207 
208 		/*
209 		 * We want to unmount the file systems in the reverse order
210 		 * that they were mounted.  So, we save off the file name
211 		 * in some allocated memory, and then call recursively.
212 		 */
213 		if ((cp = malloc((size_t)strlen(fs->fs_file) + 1)) == NULL)
214 			err(1, "malloc failed");
215 		(void)strcpy(cp, fs->fs_file);
216 		rval = umountall(typelist);
217 		rval = checkname(cp, typelist) || rval;
218 		free(cp);
219 		return (rval);
220 	} while ((fs = getfsent()) != NULL);
221 	return (0);
222 }
223 
224 /*
225  * Do magic checks on mountpoint/device/fsid, and then call unmount(2).
226  */
227 int
228 checkname(char *name, char **typelist)
229 {
230 	char buf[MAXPATHLEN];
231 	struct statfs sfsbuf;
232 	struct stat sb;
233 	struct statfs *sfs;
234 	char *delimp;
235 	dev_t dev;
236 	int len;
237 
238 	/*
239 	 * 1. Check if the name exists in the mounttable.
240 	 */
241 	sfs = checkmntlist(name);
242 	/*
243 	 * 2. Remove trailing slashes if there are any. After that
244 	 * we look up the name in the mounttable again.
245 	 */
246 	if (sfs == NULL) {
247 		len = strlen(name);
248 		while (len > 1 && name[len - 1] == '/')
249 			name[--len] = '\0';
250 		sfs = checkmntlist(name);
251 	}
252 	/*
253 	 * 3. Check if the deprecated NFS syntax with an '@' has been used
254 	 * and translate it to the ':' syntax. Look up the name in the
255 	 * mount table again.
256 	 */
257 	if (sfs == NULL && (delimp = strrchr(name, '@')) != NULL) {
258 		snprintf(buf, sizeof(buf), "%s:%.*s", delimp + 1, delimp - name,
259 		    name);
260 		len = strlen(buf);
261 		while (len > 1 && buf[len - 1] == '/')
262 			buf[--len] = '\0';
263 		sfs = checkmntlist(buf);
264 	}
265 	/*
266 	 * 4. Resort to a statfs(2) call. This is the last check so that
267 	 * hung NFS filesystems for example can be unmounted without
268 	 * potentially blocking forever in statfs() as long as the
269 	 * filesystem is specified unambiguously. This covers all the
270 	 * hard cases such as symlinks and mismatches between the
271 	 * mount list and reality.
272 	 * We also do this if an ambiguous mount point was specified.
273 	 */
274 	if (sfs == NULL || (getmntentry(NULL, name, NULL, FIND) != NULL &&
275 	    getmntentry(NULL, name, NULL, CHECKUNIQUE) == NULL)) {
276 		if (statfs(name, &sfsbuf) != 0) {
277 			warn("%s: statfs", name);
278 		} else if (stat(name, &sb) != 0) {
279 			warn("%s: stat", name);
280 		} else if (S_ISDIR(sb.st_mode)) {
281 			/* Check that `name' is the root directory. */
282 			dev = sb.st_dev;
283 			snprintf(buf, sizeof(buf), "%s/..", name);
284 			if (stat(buf, &sb) != 0) {
285 				warn("%s: stat", buf);
286 			} else if (sb.st_dev == dev) {
287 				warnx("%s: not a file system root directory",
288 				    name);
289 				return (1);
290 			} else
291 				sfs = &sfsbuf;
292 		}
293 	}
294 	if (sfs == NULL) {
295 		warnx("%s: unknown file system", name);
296 		return (1);
297 	}
298 	if (checkvfsname(sfs->f_fstypename, typelist))
299 		return (1);
300 	return (umountfs(sfs));
301 }
302 
303 /*
304  * NFS stuff and unmount(2) call
305  */
306 int
307 umountfs(struct statfs *sfs)
308 {
309 	char fsidbuf[64];
310 	enum clnt_stat clnt_stat;
311 	struct timeval try;
312 	struct addrinfo *ai, hints;
313 	int do_rpc;
314 	CLIENT *clp;
315 	char *nfsdirname, *orignfsdirname;
316 	char *hostp, *delimp;
317 
318 	ai = NULL;
319 	do_rpc = 0;
320 	hostp = NULL;
321 	nfsdirname = delimp = orignfsdirname = NULL;
322 	memset(&hints, 0, sizeof hints);
323 
324 	if (strcmp(sfs->f_fstypename, "nfs") == 0) {
325 		if ((nfsdirname = strdup(sfs->f_mntfromname)) == NULL)
326 			err(1, "strdup");
327 		orignfsdirname = nfsdirname;
328 		if ((delimp = strrchr(nfsdirname, ':')) != NULL) {
329 			*delimp = '\0';
330 			hostp = nfsdirname;
331 			getaddrinfo(hostp, NULL, &hints, &ai);
332 			if (ai == NULL) {
333 				warnx("can't get net id for host");
334 			}
335 			nfsdirname = delimp + 1;
336 		}
337 
338 		/*
339 		 * Check if we have to start the rpc-call later.
340 		 * If there are still identical nfs-names mounted,
341 		 * we skip the rpc-call. Obviously this has to
342 		 * happen before unmount(2), but it should happen
343 		 * after the previous namecheck.
344 		 * A non-NULL return means that this is the last
345 		 * mount from mntfromname that is still mounted.
346 		 */
347 		if (getmntentry(sfs->f_mntfromname, NULL, NULL,
348 		    CHECKUNIQUE) != NULL)
349 			do_rpc = 1;
350 	}
351 
352 	if (!namematch(ai))
353 		return (1);
354 	/* First try to unmount using the file system ID. */
355 	snprintf(fsidbuf, sizeof(fsidbuf), "FSID:%d:%d", sfs->f_fsid.val[0],
356 	    sfs->f_fsid.val[1]);
357 	if (unmount(fsidbuf, fflag | MNT_BYFSID) != 0) {
358 		/* XXX, non-root users get a zero fsid, so don't warn. */
359 		if (errno != ENOENT || sfs->f_fsid.val[0] != 0 ||
360 		    sfs->f_fsid.val[1] != 0)
361 			warn("unmount of %s failed", sfs->f_mntonname);
362 		if (errno != ENOENT)
363 			return (1);
364 		/* Compatibility for old kernels. */
365 		if (sfs->f_fsid.val[0] != 0 || sfs->f_fsid.val[1] != 0)
366 			warnx("retrying using path instead of file system ID");
367 		if (unmount(sfs->f_mntonname, fflag) != 0) {
368 			warn("unmount of %s failed", sfs->f_mntonname);
369 			return (1);
370 		}
371 	}
372 	/* Mark this this file system as unmounted. */
373 	getmntentry(NULL, NULL, &sfs->f_fsid, REMOVE);
374 	if (vflag)
375 		(void)printf("%s: unmount from %s\n", sfs->f_mntfromname,
376 		    sfs->f_mntonname);
377 	/*
378 	 * Report to mountd-server which nfsname
379 	 * has been unmounted.
380 	 */
381 	if (ai != NULL && !(fflag & MNT_FORCE) && do_rpc) {
382 		clp = clnt_create(hostp, RPCPROG_MNT, RPCMNT_VER1, "udp");
383 		if (clp  == NULL) {
384 			warnx("%s: %s", hostp,
385 			    clnt_spcreateerror("RPCPROG_MNT"));
386 			return (1);
387 		}
388 		clp->cl_auth = authsys_create_default();
389 		try.tv_sec = 20;
390 		try.tv_usec = 0;
391 		clnt_stat = clnt_call(clp, RPCMNT_UMOUNT, (xdrproc_t)xdr_dir,
392 		    nfsdirname, (xdrproc_t)xdr_void, (caddr_t)0, try);
393 		if (clnt_stat != RPC_SUCCESS) {
394 			warnx("%s: %s", hostp,
395 			    clnt_sperror(clp, "RPCMNT_UMOUNT"));
396 			return (1);
397 		}
398 		/*
399 		 * Remove the unmounted entry from /var/db/mounttab.
400 		 */
401 		if (read_mtab()) {
402 			clean_mtab(hostp, nfsdirname, vflag);
403 			if(!write_mtab(vflag))
404 				warnx("cannot remove mounttab entry %s:%s",
405 				    hostp, nfsdirname);
406 			free_mtab();
407 		}
408 		free(orignfsdirname);
409 		auth_destroy(clp->cl_auth);
410 		clnt_destroy(clp);
411 	}
412 	return (0);
413 }
414 
415 struct statfs *
416 getmntentry(const char *fromname, const char *onname, fsid_t *fsid, dowhat what)
417 {
418 	static struct statfs *mntbuf;
419 	static size_t mntsize = 0;
420 	static char *mntcheck = NULL;
421 	struct statfs *sfs, *foundsfs;
422 	int i, count;
423 
424 	if (mntsize <= 0) {
425 		if ((mntsize = mntinfo(&mntbuf)) <= 0)
426 			return (NULL);
427 	}
428 	if (mntcheck == NULL) {
429 		if ((mntcheck = calloc(mntsize + 1, sizeof(int))) == NULL)
430 			err(1, "calloc");
431 	}
432 	/*
433 	 * We want to get the file systems in the reverse order
434 	 * that they were mounted. Unmounted file systems are marked
435 	 * in a table called 'mntcheck'.
436 	 */
437 	count = 0;
438 	foundsfs = NULL;
439 	for (i = mntsize - 1; i >= 0; i--) {
440 		if (mntcheck[i])
441 			continue;
442 		sfs = &mntbuf[i];
443 		if (fromname != NULL && strcmp(sfs->f_mntfromname,
444 		    fromname) != 0)
445 			continue;
446 		if (onname != NULL && strcmp(sfs->f_mntonname, onname) != 0)
447 			continue;
448 		if (fsid != NULL && bcmp(&sfs->f_fsid, fsid,
449 		    sizeof(*fsid)) != 0)
450 			continue;
451 
452 		switch (what) {
453 		case CHECKUNIQUE:
454 			foundsfs = sfs;
455 			count++;
456 			continue;
457 		case REMOVE:
458 			mntcheck[i] = 1;
459 			break;
460 		default:
461 			break;
462 		}
463 		return (sfs);
464 	}
465 
466 	if (what == CHECKUNIQUE && count == 1)
467 		return (foundsfs);
468 	return (NULL);
469 }
470 
471 int
472 sacmp(struct sockaddr *sa1, struct sockaddr *sa2)
473 {
474 	void *p1, *p2;
475 	int len;
476 
477 	if (sa1->sa_family != sa2->sa_family)
478 		return (1);
479 
480 	switch (sa1->sa_family) {
481 	case AF_INET:
482 		p1 = &((struct sockaddr_in *)sa1)->sin_addr;
483 		p2 = &((struct sockaddr_in *)sa2)->sin_addr;
484 		len = 4;
485 		break;
486 	case AF_INET6:
487 		p1 = &((struct sockaddr_in6 *)sa1)->sin6_addr;
488 		p2 = &((struct sockaddr_in6 *)sa2)->sin6_addr;
489 		len = 16;
490 		if (((struct sockaddr_in6 *)sa1)->sin6_scope_id !=
491 		    ((struct sockaddr_in6 *)sa2)->sin6_scope_id)
492 			return (1);
493 		break;
494 	default:
495 		return (1);
496 	}
497 
498 	return memcmp(p1, p2, len);
499 }
500 
501 int
502 namematch(struct addrinfo *ai)
503 {
504 	struct addrinfo *aip;
505 
506 	if (nfshost == NULL || nfshost_ai == NULL)
507 		return (1);
508 
509 	while (ai != NULL) {
510 		aip = nfshost_ai;
511 		while (aip != NULL) {
512 			if (sacmp(ai->ai_addr, aip->ai_addr) == 0)
513 				return (1);
514 			aip = aip->ai_next;
515 		}
516 		ai = ai->ai_next;
517 	}
518 
519 	return (0);
520 }
521 
522 struct statfs *
523 checkmntlist(char *name)
524 {
525 	struct statfs *sfs;
526 	fsid_t fsid;
527 
528 	sfs = NULL;
529 	if (parsehexfsid(name, &fsid) == 0)
530 		sfs = getmntentry(NULL, NULL, &fsid, FIND);
531 	if (sfs == NULL)
532 		sfs = getmntentry(NULL, name, NULL, FIND);
533 	if (sfs == NULL)
534 		sfs = getmntentry(name, NULL, NULL, FIND);
535 	return (sfs);
536 }
537 
538 size_t
539 mntinfo(struct statfs **mntbuf)
540 {
541 	static struct statfs *origbuf;
542 	size_t bufsize;
543 	int mntsize;
544 
545 	mntsize = getfsstat(NULL, 0, MNT_NOWAIT);
546 	if (mntsize <= 0)
547 		return (0);
548 	bufsize = (mntsize + 1) * sizeof(struct statfs);
549 	if ((origbuf = malloc(bufsize)) == NULL)
550 		err(1, "malloc");
551 	mntsize = getfsstat(origbuf, (long)bufsize, MNT_NOWAIT);
552 	*mntbuf = origbuf;
553 	return (mntsize);
554 }
555 
556 /*
557  * Convert a hexadecimal filesystem ID to an fsid_t.
558  * Returns 0 on success.
559  */
560 int
561 parsehexfsid(const char *hex, fsid_t *fsid)
562 {
563 	char hexbuf[3];
564 	int i;
565 
566 	if (strlen(hex) != sizeof(*fsid) * 2)
567 		return (-1);
568 	hexbuf[2] = '\0';
569 	for (i = 0; i < (int)sizeof(*fsid); i++) {
570 		hexbuf[0] = hex[i * 2];
571 		hexbuf[1] = hex[i * 2 + 1];
572 		if (!isxdigit(hexbuf[0]) || !isxdigit(hexbuf[1]))
573 			return (-1);
574 		((u_char *)fsid)[i] = strtol(hexbuf, NULL, 16);
575 	}
576 	return (0);
577 }
578 
579 /*
580  * xdr routines for mount rpc's
581  */
582 int
583 xdr_dir(XDR *xdrsp, char *dirp)
584 {
585 
586 	return (xdr_string(xdrsp, &dirp, RPCMNT_PATHLEN));
587 }
588 
589 void
590 usage()
591 {
592 
593 	(void)fprintf(stderr, "%s\n%s\n",
594 	    "usage: umount [-fv] special | node | fsid",
595 	    "       umount -a | -A [-F fstab] [-fv] [-h host] [-t type]");
596 	exit(1);
597 }
598