umount.c revision 117720 
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
35static 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
42static char sccsid[] = "@(#)umount.c	8.8 (Berkeley) 5/8/95";
43#endif
44static const char rcsid[] =
45  "$FreeBSD: head/sbin/umount/umount.c 117720 2003-07-18 08:01:10Z iedowse $";
46#endif /* not lint */
47
48#include <sys/param.h>
49#include <sys/mount.h>
50#include <sys/socket.h>
51
52#include <netdb.h>
53#include <rpc/rpc.h>
54#include <nfs/rpcv2.h>
55
56#include <err.h>
57#include <errno.h>
58#include <fstab.h>
59#include <stdio.h>
60#include <stdlib.h>
61#include <string.h>
62#include <unistd.h>
63
64#include "mounttab.h"
65
66#define ISDOT(x)	((x)[0] == '.' && (x)[1] == '\0')
67#define ISDOTDOT(x)	((x)[0] == '.' && (x)[1] == '.' && (x)[2] == '\0')
68
69typedef enum { MNTON, MNTFROM, NOTHING } mntwhat;
70typedef enum { MARK, UNMARK, NAME, COUNT, FREE } dowhat;
71
72struct  addrinfo *nfshost_ai = NULL;
73int	fflag, vflag;
74char   *nfshost;
75
76struct statfs *checkmntlist(char *);
77int	 checkvfsname (const char *, char **);
78struct statfs *getmntentry(const char *, const char *, mntwhat, dowhat);
79char 	*getrealname(char *, char *resolved_path);
80char   **makevfslist (const char *);
81size_t	 mntinfo (struct statfs **);
82int	 namematch (struct addrinfo *);
83int	 sacmp (struct sockaddr *, struct sockaddr *);
84int	 umountall (char **);
85int	 checkname (char *, char **);
86int	 umountfs (char *, char *, fsid_t *, char *);
87void	 usage (void);
88int	 xdr_dir (XDR *, char *);
89
90int
91main(int argc, char *argv[])
92{
93	int all, errs, ch, mntsize, error;
94	char **typelist = NULL;
95	struct statfs *mntbuf, *sfs;
96	struct addrinfo hints;
97
98	/* Start disks transferring immediately. */
99	sync();
100
101	all = errs = 0;
102	while ((ch = getopt(argc, argv, "AaF:fh:t:v")) != -1)
103		switch (ch) {
104		case 'A':
105			all = 2;
106			break;
107		case 'a':
108			all = 1;
109			break;
110		case 'F':
111			setfstab(optarg);
112			break;
113		case 'f':
114			fflag = MNT_FORCE;
115			break;
116		case 'h':	/* -h implies -A. */
117			all = 2;
118			nfshost = optarg;
119			break;
120		case 't':
121			if (typelist != NULL)
122				err(1, "only one -t option may be specified");
123			typelist = makevfslist(optarg);
124			break;
125		case 'v':
126			vflag = 1;
127			break;
128		default:
129			usage();
130			/* NOTREACHED */
131		}
132	argc -= optind;
133	argv += optind;
134
135	if ((argc == 0 && !all) || (argc != 0 && all))
136		usage();
137
138	/* -h implies "-t nfs" if no -t flag. */
139	if ((nfshost != NULL) && (typelist == NULL))
140		typelist = makevfslist("nfs");
141
142	if (nfshost != NULL) {
143		memset(&hints, 0, sizeof hints);
144		error = getaddrinfo(nfshost, NULL, &hints, &nfshost_ai);
145		if (error)
146			errx(1, "%s: %s", nfshost, gai_strerror(error));
147	}
148
149	switch (all) {
150	case 2:
151		if ((mntsize = mntinfo(&mntbuf)) <= 0)
152			break;
153		/*
154		 * We unmount the nfs-mounts in the reverse order
155		 * that they were mounted.
156		 */
157		for (errs = 0, mntsize--; mntsize > 0; mntsize--) {
158			sfs = &mntbuf[mntsize];
159			if (checkvfsname(sfs->f_fstypename, typelist))
160				continue;
161			if (umountfs(sfs->f_mntfromname, sfs->f_mntonname,
162			    &sfs->f_fsid, sfs->f_fstypename) != 0)
163				errs = 1;
164		}
165		free(mntbuf);
166		break;
167	case 1:
168		if (setfsent() == 0)
169			err(1, "%s", getfstab());
170		errs = umountall(typelist);
171		break;
172	case 0:
173		for (errs = 0; *argv != NULL; ++argv)
174			if (checkname(*argv, typelist) != 0)
175				errs = 1;
176		break;
177	}
178	(void)getmntentry(NULL, NULL, NOTHING, FREE);
179	exit(errs);
180}
181
182int
183umountall(char **typelist)
184{
185	struct xvfsconf vfc;
186	struct fstab *fs;
187	int rval;
188	char *cp;
189	static int firstcall = 1;
190
191	if ((fs = getfsent()) != NULL)
192		firstcall = 0;
193	else if (firstcall)
194		errx(1, "fstab reading failure");
195	else
196		return (0);
197	do {
198		/* Ignore the root. */
199		if (strcmp(fs->fs_file, "/") == 0)
200			continue;
201		/*
202		 * !!!
203		 * Historic practice: ignore unknown FSTAB_* fields.
204		 */
205		if (strcmp(fs->fs_type, FSTAB_RW) &&
206		    strcmp(fs->fs_type, FSTAB_RO) &&
207		    strcmp(fs->fs_type, FSTAB_RQ))
208			continue;
209		/* Ignore unknown file system types. */
210		if (getvfsbyname(fs->fs_vfstype, &vfc) == -1)
211			continue;
212		if (checkvfsname(fs->fs_vfstype, typelist))
213			continue;
214
215		/*
216		 * We want to unmount the file systems in the reverse order
217		 * that they were mounted.  So, we save off the file name
218		 * in some allocated memory, and then call recursively.
219		 */
220		if ((cp = malloc((size_t)strlen(fs->fs_file) + 1)) == NULL)
221			err(1, "malloc failed");
222		(void)strcpy(cp, fs->fs_file);
223		rval = umountall(typelist);
224		rval = checkname(cp, typelist) || rval;
225		free(cp);
226		return (rval);
227	} while ((fs = getfsent()) != NULL);
228	return (0);
229}
230
231/*
232 * Do magic checks on mountpoint and device or hand over
233 * it to unmount(2) if everything fails.
234 */
235int
236checkname(char *name, char **typelist)
237{
238	size_t len;
239	int speclen;
240	char *resolved, realname[MAXPATHLEN];
241	char *hostp, *delimp, *origname;
242	struct statfs *sfs;
243
244	len = 0;
245	delimp = hostp = NULL;
246	sfs = NULL;
247
248	/*
249	 * 1. Check if the name exists in the mounttable.
250	 */
251	sfs = checkmntlist(name);
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		speclen = strlen(name);
258		for (speclen = strlen(name);
259		    speclen > 1 && name[speclen - 1] == '/';
260		    speclen--)
261			name[speclen - 1] = '\0';
262		sfs = checkmntlist(name);
263		resolved = name;
264		/* Save off original name in origname */
265		if ((origname = strdup(name)) == NULL)
266			err(1, "strdup");
267		/*
268		 * 3. Check if the deprecated nfs-syntax with an '@'
269		 * has been used and translate it to the ':' syntax.
270		 * Look up the name in the mounttable again.
271		 */
272		if (sfs == NULL) {
273			if ((delimp = strrchr(name, '@')) != NULL) {
274				hostp = delimp + 1;
275				if (*hostp != '\0') {
276					/*
277					 * Make both '@' and ':'
278					 * notations equal
279					 */
280					char *host = strdup(hostp);
281					len = strlen(hostp);
282					if (host == NULL)
283						err(1, "strdup");
284					memmove(name + len + 1, name,
285					    (size_t)(delimp - name));
286					name[len] = ':';
287					memmove(name, host, len);
288					free(host);
289				}
290				for (speclen = strlen(name);
291				    speclen > 1 && name[speclen - 1] == '/';
292				    speclen--)
293					name[speclen - 1] = '\0';
294				name[len + speclen + 1] = '\0';
295				sfs = checkmntlist(name);
296				resolved = name;
297			}
298			/*
299			 * 4. Check if a relative mountpoint has been
300			 * specified. This should happen as last check,
301			 * the order is important. To prevent possible
302			 * nfs-hangs, we just call realpath(3) on the
303			 * basedir of mountpoint and add the dirname again.
304			 * Check the name in mounttable one last time.
305			 */
306			if (sfs == NULL) {
307				(void)strcpy(name, origname);
308				if ((getrealname(name, realname)) != NULL) {
309					sfs = checkmntlist(realname);
310					resolved = realname;
311				}
312				/*
313				 * 5. All tests failed, just hand over the
314				 * mountpoint to the kernel, maybe the statfs
315				 * structure has been truncated or is not
316				 * useful anymore because of a chroot(2).
317				 * Please note that nfs will not be able to
318				 * notify the nfs-server about unmounting.
319				 * These things can change in future when the
320				 * fstat structure get's more reliable,
321				 * but at the moment we cannot thrust it.
322				 */
323				if (sfs == NULL) {
324					(void)strcpy(name, origname);
325					if (umountfs(NULL, origname, NULL,
326					    "none") == 0) {;
327						warnx("%s not found in "
328						    "mount table, "
329						    "unmounted it anyway",
330						    origname);
331						free(origname);
332						return (0);
333					} else
334						free(origname);
335						return (1);
336				}
337			}
338		}
339		free(origname);
340	} else
341		resolved = name;
342
343	if (checkvfsname(sfs->f_fstypename, typelist))
344		return (1);
345
346	/*
347	 * Mark the uppermost mount as unmounted.
348	 */
349	(void)getmntentry(sfs->f_mntfromname, sfs->f_mntonname, NOTHING, MARK);
350	return (umountfs(sfs->f_mntfromname, sfs->f_mntonname, &sfs->f_fsid,
351	    sfs->f_fstypename));
352}
353
354/*
355 * NFS stuff and unmount(2) call
356 */
357int
358umountfs(char *mntfromname, char *mntonname, fsid_t *fsid, char *type)
359{
360	char fsidbuf[64];
361	enum clnt_stat clnt_stat;
362	struct timeval try;
363	struct addrinfo *ai, hints;
364	int do_rpc;
365	CLIENT *clp;
366	char *nfsdirname, *orignfsdirname;
367	char *hostp, *delimp;
368
369	ai = NULL;
370	do_rpc = 0;
371	hostp = NULL;
372	nfsdirname = delimp = orignfsdirname = NULL;
373	memset(&hints, 0, sizeof hints);
374
375	if (strcmp(type, "nfs") == 0) {
376		if ((nfsdirname = strdup(mntfromname)) == NULL)
377			err(1, "strdup");
378		orignfsdirname = nfsdirname;
379		if ((delimp = strrchr(nfsdirname, ':')) != NULL) {
380			*delimp = '\0';
381			hostp = nfsdirname;
382			getaddrinfo(hostp, NULL, &hints, &ai);
383			if (ai == NULL) {
384				warnx("can't get net id for host");
385			}
386			nfsdirname = delimp + 1;
387		}
388
389		/*
390		 * Check if we have to start the rpc-call later.
391		 * If there are still identical nfs-names mounted,
392		 * we skip the rpc-call. Obviously this has to
393		 * happen before unmount(2), but it should happen
394		 * after the previous namecheck.
395		 * A non-NULL return means that this is the last
396		 * mount from mntfromname that is still mounted.
397		 */
398		if (getmntentry(mntfromname, NULL, NOTHING, COUNT) != NULL)
399			do_rpc = 1;
400	}
401
402	if (!namematch(ai))
403		return (1);
404	/* First try to unmount using the specified file system ID. */
405	if (fsid != NULL) {
406		snprintf(fsidbuf, sizeof(fsidbuf), "FSID:%d:%d", fsid->val[0],
407		    fsid->val[1]);
408		if (unmount(fsidbuf, fflag | MNT_BYFSID) != 0) {
409			warn("unmount of %s failed", mntonname);
410			if (errno != ENOENT)
411				return (1);
412			/* Compatability for old kernels. */
413			warnx("retrying using path instead of file system ID");
414			fsid = NULL;
415		}
416	}
417	if (fsid == NULL && unmount(mntonname, fflag) != 0) {
418		warn("unmount of %s failed", mntonname);
419		return (1);
420	}
421	if (vflag)
422		(void)printf("%s: unmount from %s\n", mntfromname, mntonname);
423	/*
424	 * Report to mountd-server which nfsname
425	 * has been unmounted.
426	 */
427	if (ai != NULL && !(fflag & MNT_FORCE) && do_rpc) {
428		clp = clnt_create(hostp, RPCPROG_MNT, RPCMNT_VER1, "udp");
429		if (clp  == NULL) {
430			warnx("%s: %s", hostp,
431			    clnt_spcreateerror("RPCPROG_MNT"));
432			return (1);
433		}
434		clp->cl_auth = authsys_create_default();
435		try.tv_sec = 20;
436		try.tv_usec = 0;
437		clnt_stat = clnt_call(clp, RPCMNT_UMOUNT, (xdrproc_t)xdr_dir,
438		    nfsdirname, (xdrproc_t)xdr_void, (caddr_t)0, try);
439		if (clnt_stat != RPC_SUCCESS) {
440			warnx("%s: %s", hostp,
441			    clnt_sperror(clp, "RPCMNT_UMOUNT"));
442			return (1);
443		}
444		/*
445		 * Remove the unmounted entry from /var/db/mounttab.
446		 */
447		if (read_mtab()) {
448			clean_mtab(hostp, nfsdirname, vflag);
449			if(!write_mtab(vflag))
450				warnx("cannot remove mounttab entry %s:%s",
451				    hostp, nfsdirname);
452			free_mtab();
453		}
454		free(orignfsdirname);
455		auth_destroy(clp->cl_auth);
456		clnt_destroy(clp);
457	}
458	return (0);
459}
460
461struct statfs *
462getmntentry(const char *fromname, const char *onname, mntwhat what, dowhat mark)
463{
464	static struct statfs *mntbuf;
465	static size_t mntsize = 0;
466	static char *mntcheck = NULL;
467	static char *mntcount = NULL;
468	int i, count;
469
470	if (mntsize <= 0) {
471		if ((mntsize = mntinfo(&mntbuf)) <= 0)
472			return (NULL);
473	}
474	if (mntcheck == NULL) {
475		if ((mntcheck = calloc(mntsize + 1, sizeof(int))) == NULL ||
476		    (mntcount = calloc(mntsize + 1, sizeof(int))) == NULL)
477			err(1, "calloc");
478	}
479	/*
480	 * We want to get the file systems in the reverse order
481	 * that they were mounted. Mounted and unmounted file systems
482	 * are marked or unmarked in a table called 'mntcheck'.
483	 * Unmount(const char *dir, int flags) does only take the
484	 * mountpoint as argument, not the destination. If we don't pay
485	 * attention to the order, it can happen that an overlaying
486	 * file system gets unmounted instead of the one the user
487	 * has choosen.
488	 */
489	switch (mark) {
490	case NAME:
491		/* Return only the specific name */
492		for (i = mntsize - 1; i >= 0; i--) {
493			if (fromname != NULL && !strcmp((what == MNTFROM) ?
494			    mntbuf[i].f_mntfromname : mntbuf[i].f_mntonname,
495			    fromname) && mntcheck[i] != 1)
496				return (&mntbuf[i]);
497		}
498
499		return (NULL);
500	case MARK:
501		/* Mark current mount with '1' and return name */
502		for (i = mntsize - 1; i >= 0; i--) {
503			if (mntcheck[i] == 0 &&
504			    (strcmp(mntbuf[i].f_mntonname, onname) == 0) &&
505			    (strcmp(mntbuf[i].f_mntfromname, fromname) == 0)) {
506				mntcheck[i] = 1;
507				return (&mntbuf[i]);
508			}
509		}
510		return (NULL);
511	case UNMARK:
512		/* Unmark current mount with '0' and return name */
513		for (i = 0; i < mntsize; i++) {
514			if (mntcheck[i] == 1 &&
515			    (strcmp(mntbuf[i].f_mntonname, onname) == 0) &&
516			    (strcmp(mntbuf[i].f_mntfromname, fromname) == 0)) {
517				mntcheck[i] = 0;
518				return (&mntbuf[i]);
519			}
520		}
521		return (NULL);
522	case COUNT:
523		/* Count the equal mntfromnames */
524		count = 0;
525		for (i = mntsize - 1; i >= 0; i--) {
526			if (strcmp(mntbuf[i].f_mntfromname, fromname) == 0)
527				count++;
528		}
529		/* Mark the already unmounted mounts and return
530		 * mntfromname if count <= 1. Else return NULL.
531		 */
532		for (i = mntsize - 1; i >= 0; i--) {
533			if (strcmp(mntbuf[i].f_mntfromname, fromname) == 0) {
534				if (mntcount[i] == 1)
535					count--;
536				else {
537					mntcount[i] = 1;
538					break;
539				}
540			}
541		}
542		if (count <= 1)
543			return (&mntbuf[i]);
544		else
545			return (NULL);
546	case FREE:
547		free(mntbuf);
548		free(mntcheck);
549		free(mntcount);
550		return (NULL);
551	default:
552		return (NULL);
553	}
554}
555
556int
557sacmp(struct sockaddr *sa1, struct sockaddr *sa2)
558{
559	void *p1, *p2;
560	int len;
561
562	if (sa1->sa_family != sa2->sa_family)
563		return (1);
564
565	switch (sa1->sa_family) {
566	case AF_INET:
567		p1 = &((struct sockaddr_in *)sa1)->sin_addr;
568		p2 = &((struct sockaddr_in *)sa2)->sin_addr;
569		len = 4;
570		break;
571	case AF_INET6:
572		p1 = &((struct sockaddr_in6 *)sa1)->sin6_addr;
573		p2 = &((struct sockaddr_in6 *)sa2)->sin6_addr;
574		len = 16;
575		if (((struct sockaddr_in6 *)sa1)->sin6_scope_id !=
576		    ((struct sockaddr_in6 *)sa2)->sin6_scope_id)
577			return (1);
578		break;
579	default:
580		return (1);
581	}
582
583	return memcmp(p1, p2, len);
584}
585
586int
587namematch(struct addrinfo *ai)
588{
589	struct addrinfo *aip;
590
591	if (nfshost == NULL || nfshost_ai == NULL)
592		return (1);
593
594	while (ai != NULL) {
595		aip = nfshost_ai;
596		while (aip != NULL) {
597			if (sacmp(ai->ai_addr, aip->ai_addr) == 0)
598				return (1);
599			aip = aip->ai_next;
600		}
601		ai = ai->ai_next;
602	}
603
604	return (0);
605}
606
607struct statfs *
608checkmntlist(char *name)
609{
610	struct statfs *sfs;
611
612	sfs = getmntentry(name, NULL, MNTON, NAME);
613	if (sfs == NULL)
614		sfs = getmntentry(name, NULL, MNTFROM, NAME);
615	return (sfs);
616}
617
618size_t
619mntinfo(struct statfs **mntbuf)
620{
621	static struct statfs *origbuf;
622	size_t bufsize;
623	int mntsize;
624
625	mntsize = getfsstat(NULL, 0, MNT_NOWAIT);
626	if (mntsize <= 0)
627		return (0);
628	bufsize = (mntsize + 1) * sizeof(struct statfs);
629	if ((origbuf = malloc(bufsize)) == NULL)
630		err(1, "malloc");
631	mntsize = getfsstat(origbuf, (long)bufsize, MNT_NOWAIT);
632	*mntbuf = origbuf;
633	return (mntsize);
634}
635
636char *
637getrealname(char *name, char *realname)
638{
639	char *dirname;
640	int havedir;
641	size_t baselen;
642	size_t dirlen;
643
644	dirname = '\0';
645	havedir = 0;
646	if (*name == '/') {
647		if (ISDOT(name + 1) || ISDOTDOT(name + 1))
648			strcpy(realname, "/");
649		else {
650			if ((dirname = strrchr(name + 1, '/')) == NULL)
651				snprintf(realname, MAXPATHLEN, "%s", name);
652			else
653				havedir = 1;
654		}
655	} else {
656		if (ISDOT(name) || ISDOTDOT(name))
657			(void)realpath(name, realname);
658		else {
659			if ((dirname = strrchr(name, '/')) == NULL) {
660				if ((realpath(name, realname)) == NULL)
661					return (NULL);
662			} else
663				havedir = 1;
664		}
665	}
666	if (havedir) {
667		*dirname++ = '\0';
668		if (ISDOT(dirname)) {
669			*dirname = '\0';
670			if ((realpath(name, realname)) == NULL)
671				return (NULL);
672		} else if (ISDOTDOT(dirname)) {
673			*--dirname = '/';
674			if ((realpath(name, realname)) == NULL)
675				return (NULL);
676		} else {
677			if ((realpath(name, realname)) == NULL)
678				return (NULL);
679			baselen = strlen(realname);
680			dirlen = strlen(dirname);
681			if (baselen + dirlen + 1 > MAXPATHLEN)
682				return (NULL);
683			if (realname[1] == '\0') {
684				memmove(realname + 1, dirname, dirlen);
685				realname[dirlen + 1] = '\0';
686			} else {
687				realname[baselen] = '/';
688				memmove(realname + baselen + 1,
689				    dirname, dirlen);
690				realname[baselen + dirlen + 1] = '\0';
691			}
692		}
693	}
694	return (realname);
695}
696
697/*
698 * xdr routines for mount rpc's
699 */
700int
701xdr_dir(XDR *xdrsp, char *dirp)
702{
703
704	return (xdr_string(xdrsp, &dirp, RPCMNT_PATHLEN));
705}
706
707void
708usage()
709{
710
711	(void)fprintf(stderr, "%s\n%s\n",
712	    "usage: umount [-fv] special | node",
713	    "       umount -a | -A [ -F fstab] [-fv] [-h host] [-t type]");
714	exit(1);
715}
716