xref: /freebsd/sbin/umount/umount.c (revision 23f6875a43f7ce365f2d52cf857da010c47fb03b)
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 #include <nfs/nfssvc.h>
53 
54 #include <ctype.h>
55 #include <err.h>
56 #include <errno.h>
57 #include <fstab.h>
58 #include <stdio.h>
59 #include <stdlib.h>
60 #include <string.h>
61 #include <unistd.h>
62 
63 #include "mounttab.h"
64 
65 typedef enum { FIND, REMOVE, CHECKUNIQUE } dowhat;
66 
67 static struct addrinfo *nfshost_ai = NULL;
68 static int	fflag, vflag;
69 static char	*nfshost;
70 
71 struct statfs *checkmntlist(char *);
72 int	 checkvfsname (const char *, char **);
73 struct statfs *getmntentry(const char *fromname, const char *onname,
74 	     fsid_t *fsid, dowhat what);
75 char   **makevfslist (const char *);
76 size_t	 mntinfo (struct statfs **);
77 int	 namematch (struct addrinfo *);
78 int	 parsehexfsid(const char *hex, fsid_t *fsid);
79 int	 sacmp (void *, void *);
80 int	 umountall (char **);
81 int	 checkname (char *, char **);
82 int	 umountfs(struct statfs *sfs);
83 void	 usage (void);
84 int	 xdr_dir (XDR *, char *);
85 
86 int
87 main(int argc, char *argv[])
88 {
89 	int all, errs, ch, mntsize, error;
90 	char **typelist = NULL;
91 	struct statfs *mntbuf, *sfs;
92 	struct addrinfo hints;
93 
94 	all = errs = 0;
95 	while ((ch = getopt(argc, argv, "AaF:fh:nt:v")) != -1)
96 		switch (ch) {
97 		case 'A':
98 			all = 2;
99 			break;
100 		case 'a':
101 			all = 1;
102 			break;
103 		case 'F':
104 			setfstab(optarg);
105 			break;
106 		case 'f':
107 			fflag |= MNT_FORCE;
108 			break;
109 		case 'h':	/* -h implies -A. */
110 			all = 2;
111 			nfshost = optarg;
112 			break;
113 		case 'n':
114 			fflag |= MNT_NONBUSY;
115 			break;
116 		case 't':
117 			if (typelist != NULL)
118 				err(1, "only one -t option may be specified");
119 			typelist = makevfslist(optarg);
120 			break;
121 		case 'v':
122 			vflag = 1;
123 			break;
124 		default:
125 			usage();
126 			/* NOTREACHED */
127 		}
128 	argc -= optind;
129 	argv += optind;
130 
131 	if ((fflag & MNT_FORCE) != 0 && (fflag & MNT_NONBUSY) != 0)
132 		err(1, "-f and -n are mutually exclusive");
133 
134 	/* Start disks transferring immediately. */
135 	if ((fflag & (MNT_FORCE | MNT_NONBUSY)) == 0)
136 		sync();
137 
138 	if ((argc == 0 && !all) || (argc != 0 && all))
139 		usage();
140 
141 	/* -h implies "-t nfs" if no -t flag. */
142 	if ((nfshost != NULL) && (typelist == NULL))
143 		typelist = makevfslist("nfs");
144 
145 	if (nfshost != NULL) {
146 		memset(&hints, 0, sizeof hints);
147 		error = getaddrinfo(nfshost, NULL, &hints, &nfshost_ai);
148 		if (error)
149 			errx(1, "%s: %s", nfshost, gai_strerror(error));
150 	}
151 
152 	switch (all) {
153 	case 2:
154 		if ((mntsize = mntinfo(&mntbuf)) <= 0)
155 			break;
156 		/*
157 		 * We unmount the nfs-mounts in the reverse order
158 		 * that they were mounted.
159 		 */
160 		for (errs = 0, mntsize--; mntsize > 0; mntsize--) {
161 			sfs = &mntbuf[mntsize];
162 			if (checkvfsname(sfs->f_fstypename, typelist))
163 				continue;
164 			if (strcmp(sfs->f_mntonname, "/dev") == 0)
165 				continue;
166 			if (umountfs(sfs) != 0)
167 				errs = 1;
168 		}
169 		free(mntbuf);
170 		break;
171 	case 1:
172 		if (setfsent() == 0)
173 			err(1, "%s", getfstab());
174 		errs = umountall(typelist);
175 		break;
176 	case 0:
177 		for (errs = 0; *argv != NULL; ++argv)
178 			if (checkname(*argv, typelist) != 0)
179 				errs = 1;
180 		break;
181 	}
182 	exit(errs);
183 }
184 
185 int
186 umountall(char **typelist)
187 {
188 	struct xvfsconf vfc;
189 	struct fstab *fs;
190 	int rval;
191 	char *cp;
192 	static int firstcall = 1;
193 
194 	if ((fs = getfsent()) != NULL)
195 		firstcall = 0;
196 	else if (firstcall)
197 		errx(1, "fstab reading failure");
198 	else
199 		return (0);
200 	do {
201 		/* Ignore the root. */
202 		if (strcmp(fs->fs_file, "/") == 0)
203 			continue;
204 		/*
205 		 * !!!
206 		 * Historic practice: ignore unknown FSTAB_* fields.
207 		 */
208 		if (strcmp(fs->fs_type, FSTAB_RW) &&
209 		    strcmp(fs->fs_type, FSTAB_RO) &&
210 		    strcmp(fs->fs_type, FSTAB_RQ))
211 			continue;
212 		/* Ignore unknown file system types. */
213 		if (getvfsbyname(fs->fs_vfstype, &vfc) == -1)
214 			continue;
215 		if (checkvfsname(fs->fs_vfstype, typelist))
216 			continue;
217 
218 		/*
219 		 * We want to unmount the file systems in the reverse order
220 		 * that they were mounted.  So, we save off the file name
221 		 * in some allocated memory, and then call recursively.
222 		 */
223 		if ((cp = malloc((size_t)strlen(fs->fs_file) + 1)) == NULL)
224 			err(1, "malloc failed");
225 		(void)strcpy(cp, fs->fs_file);
226 		rval = umountall(typelist);
227 		rval = checkname(cp, typelist) || rval;
228 		free(cp);
229 		return (rval);
230 	} while ((fs = getfsent()) != NULL);
231 	return (0);
232 }
233 
234 /*
235  * Do magic checks on mountpoint/device/fsid, and then call unmount(2).
236  */
237 int
238 checkname(char *mntname, char **typelist)
239 {
240 	char buf[MAXPATHLEN];
241 	struct statfs sfsbuf;
242 	struct stat sb;
243 	struct statfs *sfs;
244 	char *delimp;
245 	dev_t dev;
246 	int len;
247 
248 	/*
249 	 * 1. Check if the name exists in the mounttable.
250 	 */
251 	sfs = checkmntlist(mntname);
252 	/*
253 	 * 2. Remove trailing slashes if there are any. After that
254 	 * we look up the name in the mounttable again.
255 	 */
256 	if (sfs == NULL) {
257 		len = strlen(mntname);
258 		while (len > 1 && mntname[len - 1] == '/')
259 			mntname[--len] = '\0';
260 		sfs = checkmntlist(mntname);
261 	}
262 	/*
263 	 * 3. Check if the deprecated NFS syntax with an '@' has been used
264 	 * and translate it to the ':' syntax. Look up the name in the
265 	 * mount table again.
266 	 */
267 	if (sfs == NULL && (delimp = strrchr(mntname, '@')) != NULL) {
268 		snprintf(buf, sizeof(buf), "%s:%.*s", delimp + 1,
269 		    (int)(delimp - mntname), mntname);
270 		len = strlen(buf);
271 		while (len > 1 && buf[len - 1] == '/')
272 			buf[--len] = '\0';
273 		sfs = checkmntlist(buf);
274 	}
275 	/*
276 	 * 4. Resort to a statfs(2) call. This is the last check so that
277 	 * hung NFS filesystems for example can be unmounted without
278 	 * potentially blocking forever in statfs() as long as the
279 	 * filesystem is specified unambiguously. This covers all the
280 	 * hard cases such as symlinks and mismatches between the
281 	 * mount list and reality.
282 	 * We also do this if an ambiguous mount point was specified.
283 	 */
284 	if (sfs == NULL || (getmntentry(NULL, mntname, NULL, FIND) != NULL &&
285 	    getmntentry(NULL, mntname, NULL, CHECKUNIQUE) == NULL)) {
286 		if (statfs(mntname, &sfsbuf) != 0) {
287 			warn("%s: statfs", mntname);
288 		} else if (stat(mntname, &sb) != 0) {
289 			warn("%s: stat", mntname);
290 		} else if (S_ISDIR(sb.st_mode)) {
291 			/* Check that `mntname' is the root directory. */
292 			dev = sb.st_dev;
293 			snprintf(buf, sizeof(buf), "%s/..", mntname);
294 			if (stat(buf, &sb) != 0) {
295 				warn("%s: stat", buf);
296 			} else if (sb.st_dev == dev) {
297 				warnx("%s: not a file system root directory",
298 				    mntname);
299 				return (1);
300 			} else
301 				sfs = &sfsbuf;
302 		}
303 	}
304 	if (sfs == NULL) {
305 		warnx("%s: unknown file system", mntname);
306 		return (1);
307 	}
308 	if (checkvfsname(sfs->f_fstypename, typelist))
309 		return (1);
310 	return (umountfs(sfs));
311 }
312 
313 /*
314  * NFS stuff and unmount(2) call
315  */
316 int
317 umountfs(struct statfs *sfs)
318 {
319 	char fsidbuf[64];
320 	enum clnt_stat clnt_stat;
321 	struct timeval try;
322 	struct addrinfo *ai, hints;
323 	int do_rpc;
324 	CLIENT *clp;
325 	char *nfsdirname, *orignfsdirname;
326 	char *hostp, *delimp;
327 	char buf[1024];
328 	struct nfscl_dumpmntopts dumpmntopts;
329 	const char *proto_ptr = NULL;
330 
331 	ai = NULL;
332 	do_rpc = 0;
333 	hostp = NULL;
334 	nfsdirname = delimp = orignfsdirname = NULL;
335 	memset(&hints, 0, sizeof hints);
336 
337 	if (strcmp(sfs->f_fstypename, "nfs") == 0) {
338 		if ((nfsdirname = strdup(sfs->f_mntfromname)) == NULL)
339 			err(1, "strdup");
340 		orignfsdirname = nfsdirname;
341 		if (*nfsdirname == '[' &&
342 		    (delimp = strchr(nfsdirname + 1, ']')) != NULL &&
343 		    *(delimp + 1) == ':') {
344 			hostp = nfsdirname + 1;
345 			nfsdirname = delimp + 2;
346 		} else if ((delimp = strrchr(nfsdirname, ':')) != NULL) {
347 			hostp = nfsdirname;
348 			nfsdirname = delimp + 1;
349 		}
350 		if (hostp != NULL) {
351 			*delimp = '\0';
352 			getaddrinfo(hostp, NULL, &hints, &ai);
353 			if (ai == NULL) {
354 				warnx("can't get net id for host");
355 			}
356 		}
357 
358 		/*
359 		 * Check if we have to start the rpc-call later.
360 		 * If there are still identical nfs-names mounted,
361 		 * we skip the rpc-call. Obviously this has to
362 		 * happen before unmount(2), but it should happen
363 		 * after the previous namecheck.
364 		 * A non-NULL return means that this is the last
365 		 * mount from mntfromname that is still mounted.
366 		 */
367 		if (getmntentry(sfs->f_mntfromname, NULL, NULL,
368 		    CHECKUNIQUE) != NULL) {
369 			do_rpc = 1;
370 			proto_ptr = "udp";
371 			/*
372 			 * Try and find out whether this NFS mount is NFSv4 and
373 			 * what protocol is being used. If this fails, the
374 			 * default is NFSv2,3 and use UDP for the Unmount RPC.
375 			 */
376 			dumpmntopts.ndmnt_fname = sfs->f_mntonname;
377 			dumpmntopts.ndmnt_buf = buf;
378 			dumpmntopts.ndmnt_blen = sizeof(buf);
379 			if (nfssvc(NFSSVC_DUMPMNTOPTS, &dumpmntopts) >= 0) {
380 				if (strstr(buf, "nfsv4,") != NULL)
381 					do_rpc = 0;
382 				else if (strstr(buf, ",tcp,") != NULL)
383 					proto_ptr = "tcp";
384 			}
385 		}
386 	}
387 
388 	if (!namematch(ai)) {
389 		free(orignfsdirname);
390 		return (1);
391 	}
392 	/* First try to unmount using the file system ID. */
393 	snprintf(fsidbuf, sizeof(fsidbuf), "FSID:%d:%d", sfs->f_fsid.val[0],
394 	    sfs->f_fsid.val[1]);
395 	if (unmount(fsidbuf, fflag | MNT_BYFSID) != 0) {
396 		/* XXX, non-root users get a zero fsid, so don't warn. */
397 		if (errno != ENOENT || sfs->f_fsid.val[0] != 0 ||
398 		    sfs->f_fsid.val[1] != 0)
399 			warn("unmount of %s failed", sfs->f_mntonname);
400 		if (errno != ENOENT) {
401 			free(orignfsdirname);
402 			return (1);
403 		}
404 		/* Compatibility for old kernels. */
405 		if (sfs->f_fsid.val[0] != 0 || sfs->f_fsid.val[1] != 0)
406 			warnx("retrying using path instead of file system ID");
407 		if (unmount(sfs->f_mntonname, fflag) != 0) {
408 			warn("unmount of %s failed", sfs->f_mntonname);
409 			free(orignfsdirname);
410 			return (1);
411 		}
412 	}
413 	/* Mark this this file system as unmounted. */
414 	getmntentry(NULL, NULL, &sfs->f_fsid, REMOVE);
415 	if (vflag)
416 		(void)printf("%s: unmount from %s\n", sfs->f_mntfromname,
417 		    sfs->f_mntonname);
418 	/*
419 	 * Report to mountd-server which nfsname
420 	 * has been unmounted.
421 	 */
422 	if (ai != NULL && !(fflag & MNT_FORCE) && do_rpc) {
423 		clp = clnt_create(hostp, MOUNTPROG, MOUNTVERS3, proto_ptr);
424 		if (clp  == NULL) {
425 			warnx("%s: %s", hostp,
426 			    clnt_spcreateerror("MOUNTPROG"));
427 			free(orignfsdirname);
428 			return (1);
429 		}
430 		clp->cl_auth = authsys_create_default();
431 		try.tv_sec = 20;
432 		try.tv_usec = 0;
433 		clnt_stat = clnt_call(clp, MOUNTPROC_UMNT, (xdrproc_t)xdr_dir,
434 		    nfsdirname, (xdrproc_t)xdr_void, (caddr_t)0, try);
435 		if (clnt_stat != RPC_SUCCESS) {
436 			warnx("%s: %s", hostp,
437 			    clnt_sperror(clp, "RPCMNT_UMOUNT"));
438 			free(orignfsdirname);
439 			return (1);
440 		}
441 		/*
442 		 * Remove the unmounted entry from /var/db/mounttab.
443 		 */
444 		if (read_mtab()) {
445 			clean_mtab(hostp, nfsdirname, vflag);
446 			if(!write_mtab(vflag))
447 				warnx("cannot remove mounttab entry %s:%s",
448 				    hostp, nfsdirname);
449 			free_mtab();
450 		}
451 		auth_destroy(clp->cl_auth);
452 		clnt_destroy(clp);
453 	}
454 	free(orignfsdirname);
455 	return (0);
456 }
457 
458 struct statfs *
459 getmntentry(const char *fromname, const char *onname, fsid_t *fsid, dowhat what)
460 {
461 	static struct statfs *mntbuf;
462 	static size_t mntsize = 0;
463 	static int *mntcheck = NULL;
464 	struct statfs *sfs, *foundsfs;
465 	int i, count;
466 
467 	if (mntsize <= 0) {
468 		if ((mntsize = mntinfo(&mntbuf)) <= 0)
469 			return (NULL);
470 	}
471 	if (mntcheck == NULL) {
472 		if ((mntcheck = calloc(mntsize + 1, sizeof(int))) == NULL)
473 			err(1, "calloc");
474 	}
475 	/*
476 	 * We want to get the file systems in the reverse order
477 	 * that they were mounted. Unmounted file systems are marked
478 	 * in a table called 'mntcheck'.
479 	 */
480 	count = 0;
481 	foundsfs = NULL;
482 	for (i = mntsize - 1; i >= 0; i--) {
483 		if (mntcheck[i])
484 			continue;
485 		sfs = &mntbuf[i];
486 		if (fromname != NULL && strcmp(sfs->f_mntfromname,
487 		    fromname) != 0)
488 			continue;
489 		if (onname != NULL && strcmp(sfs->f_mntonname, onname) != 0)
490 			continue;
491 		if (fsid != NULL && bcmp(&sfs->f_fsid, fsid,
492 		    sizeof(*fsid)) != 0)
493 			continue;
494 
495 		switch (what) {
496 		case CHECKUNIQUE:
497 			foundsfs = sfs;
498 			count++;
499 			continue;
500 		case REMOVE:
501 			mntcheck[i] = 1;
502 			break;
503 		default:
504 			break;
505 		}
506 		return (sfs);
507 	}
508 
509 	if (what == CHECKUNIQUE && count == 1)
510 		return (foundsfs);
511 	return (NULL);
512 }
513 
514 int
515 sacmp(void *sa1, void *sa2)
516 {
517 	void *p1, *p2;
518 	int len;
519 
520 	if (((struct sockaddr *)sa1)->sa_family !=
521 	    ((struct sockaddr *)sa2)->sa_family)
522 		return (1);
523 
524 	switch (((struct sockaddr *)sa1)->sa_family) {
525 	case AF_INET:
526 		p1 = &((struct sockaddr_in *)sa1)->sin_addr;
527 		p2 = &((struct sockaddr_in *)sa2)->sin_addr;
528 		len = 4;
529 		break;
530 	case AF_INET6:
531 		p1 = &((struct sockaddr_in6 *)sa1)->sin6_addr;
532 		p2 = &((struct sockaddr_in6 *)sa2)->sin6_addr;
533 		len = 16;
534 		if (((struct sockaddr_in6 *)sa1)->sin6_scope_id !=
535 		    ((struct sockaddr_in6 *)sa2)->sin6_scope_id)
536 			return (1);
537 		break;
538 	default:
539 		return (1);
540 	}
541 
542 	return memcmp(p1, p2, len);
543 }
544 
545 int
546 namematch(struct addrinfo *ai)
547 {
548 	struct addrinfo *aip;
549 
550 	if (nfshost == NULL || nfshost_ai == NULL)
551 		return (1);
552 
553 	while (ai != NULL) {
554 		aip = nfshost_ai;
555 		while (aip != NULL) {
556 			if (sacmp(ai->ai_addr, aip->ai_addr) == 0)
557 				return (1);
558 			aip = aip->ai_next;
559 		}
560 		ai = ai->ai_next;
561 	}
562 
563 	return (0);
564 }
565 
566 struct statfs *
567 checkmntlist(char *mntname)
568 {
569 	struct statfs *sfs;
570 	fsid_t fsid;
571 
572 	sfs = NULL;
573 	if (parsehexfsid(mntname, &fsid) == 0)
574 		sfs = getmntentry(NULL, NULL, &fsid, FIND);
575 	if (sfs == NULL)
576 		sfs = getmntentry(NULL, mntname, NULL, FIND);
577 	if (sfs == NULL)
578 		sfs = getmntentry(mntname, NULL, NULL, FIND);
579 	return (sfs);
580 }
581 
582 size_t
583 mntinfo(struct statfs **mntbuf)
584 {
585 	static struct statfs *origbuf;
586 	size_t bufsize;
587 	int mntsize;
588 
589 	mntsize = getfsstat(NULL, 0, MNT_NOWAIT);
590 	if (mntsize <= 0)
591 		return (0);
592 	bufsize = (mntsize + 1) * sizeof(struct statfs);
593 	if ((origbuf = malloc(bufsize)) == NULL)
594 		err(1, "malloc");
595 	mntsize = getfsstat(origbuf, (long)bufsize, MNT_NOWAIT);
596 	*mntbuf = origbuf;
597 	return (mntsize);
598 }
599 
600 /*
601  * Convert a hexadecimal filesystem ID to an fsid_t.
602  * Returns 0 on success.
603  */
604 int
605 parsehexfsid(const char *hex, fsid_t *fsid)
606 {
607 	char hexbuf[3];
608 	int i;
609 
610 	if (strlen(hex) != sizeof(*fsid) * 2)
611 		return (-1);
612 	hexbuf[2] = '\0';
613 	for (i = 0; i < (int)sizeof(*fsid); i++) {
614 		hexbuf[0] = hex[i * 2];
615 		hexbuf[1] = hex[i * 2 + 1];
616 		if (!isxdigit(hexbuf[0]) || !isxdigit(hexbuf[1]))
617 			return (-1);
618 		((u_char *)fsid)[i] = strtol(hexbuf, NULL, 16);
619 	}
620 	return (0);
621 }
622 
623 /*
624  * xdr routines for mount rpc's
625  */
626 int
627 xdr_dir(XDR *xdrsp, char *dirp)
628 {
629 
630 	return (xdr_string(xdrsp, &dirp, MNTPATHLEN));
631 }
632 
633 void
634 usage(void)
635 {
636 
637 	(void)fprintf(stderr, "%s\n%s\n",
638 	    "usage: umount [-fnv] special ... | node ... | fsid ...",
639 	    "       umount -a | -A [-F fstab] [-fnv] [-h host] [-t type]");
640 	exit(1);
641 }
642