mount.c revision 187035 
1/*-
2 * Copyright (c) 1980, 1989, 1993, 1994
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
31static const char copyright[] =
32"@(#) Copyright (c) 1980, 1989, 1993, 1994\n\
33	The Regents of the University of California.  All rights reserved.\n";
34#endif /* not lint */
35
36#ifndef lint
37#if 0
38static char sccsid[] = "@(#)mount.c	8.25 (Berkeley) 5/8/95";
39#endif
40static const char rcsid[] =
41  "$FreeBSD: head/sbin/mount/mount.c 187035 2009-01-10 20:54:47Z obrien $";
42#endif /* not lint */
43
44#include <sys/param.h>
45#include <sys/mount.h>
46#include <sys/stat.h>
47#include <sys/wait.h>
48
49#include <ctype.h>
50#include <err.h>
51#include <errno.h>
52#include <fstab.h>
53#include <paths.h>
54#include <pwd.h>
55#include <signal.h>
56#include <stdint.h>
57#include <stdio.h>
58#include <stdlib.h>
59#include <string.h>
60#include <unistd.h>
61#include <libutil.h>
62
63#include "extern.h"
64#include "mntopts.h"
65#include "pathnames.h"
66
67/* `meta' options */
68#define MOUNT_META_OPTION_FSTAB		"fstab"
69#define MOUNT_META_OPTION_CURRENT	"current"
70
71int debug, fstab_style, verbose;
72
73#define	MAX_ARGS 100
74struct cpa {
75	char	*a[MAX_ARGS];
76	ssize_t	m;
77	int	c;
78};
79
80char   *catopt(char *, const char *);
81struct statfs *getmntpt(const char *);
82int	hasopt(const char *, const char *);
83int	ismounted(struct fstab *, struct statfs *, int);
84int	isremountable(const char *);
85void	mangle(char *, struct cpa *);
86char   *update_options(char *, char *, int);
87int	mountfs(const char *, const char *, const char *,
88			int, const char *, const char *);
89void	remopt(char *, const char *);
90void	prmount(struct statfs *);
91void	putfsent(struct statfs *);
92void	usage(void);
93char   *flags2opts(int);
94
95/* Map from mount options to printable formats. */
96static struct opt {
97	int o_opt;
98	const char *o_name;
99} optnames[] = {
100	{ MNT_ASYNC,		"asynchronous" },
101	{ MNT_EXPORTED,		"NFS exported" },
102	{ MNT_LOCAL,		"local" },
103	{ MNT_NOATIME,		"noatime" },
104	{ MNT_NOEXEC,		"noexec" },
105	{ MNT_NOSUID,		"nosuid" },
106	{ MNT_NOSYMFOLLOW,	"nosymfollow" },
107	{ MNT_QUOTA,		"with quotas" },
108	{ MNT_RDONLY,		"read-only" },
109	{ MNT_SYNCHRONOUS,	"synchronous" },
110	{ MNT_UNION,		"union" },
111	{ MNT_NOCLUSTERR,	"noclusterr" },
112	{ MNT_NOCLUSTERW,	"noclusterw" },
113	{ MNT_SUIDDIR,		"suiddir" },
114	{ MNT_SOFTDEP,		"soft-updates" },
115	{ MNT_MULTILABEL,	"multilabel" },
116	{ MNT_ACLS,		"acls" },
117	{ MNT_GJOURNAL,		"gjournal" },
118	{ 0, NULL }
119};
120
121/*
122 * List of VFS types that can be remounted without becoming mounted on top
123 * of each other.
124 * XXX Is this list correct?
125 */
126static const char *
127remountable_fs_names[] = {
128	"ufs", "ffs", "ext2fs",
129	0
130};
131
132static const char userquotaeq[] = "userquota=";
133static const char groupquotaeq[] = "groupquota=";
134
135static int
136use_mountprog(const char *vfstype)
137{
138	/* XXX: We need to get away from implementing external mount
139	 *      programs for every filesystem, and move towards having
140	 *	each filesystem properly implement the nmount() system call.
141	 */
142	unsigned int i;
143	const char *fs[] = {
144	"cd9660", "mfs", "msdosfs", "nfs", "nfs4", "ntfs",
145	"nwfs", "nullfs", "portalfs", "smbfs", "udf", "unionfs",
146	NULL
147	};
148
149	for (i = 0; fs[i] != NULL; ++i) {
150		if (strcmp(vfstype, fs[i]) == 0)
151			return (1);
152	}
153
154	return (0);
155}
156
157static int
158exec_mountprog(const char *name, const char *execname, char *const argv[])
159{
160	pid_t pid;
161	int status;
162
163	switch (pid = fork()) {
164	case -1:				/* Error. */
165		warn("fork");
166		exit (1);
167	case 0:					/* Child. */
168		/* Go find an executable. */
169		execvP(execname, _PATH_SYSPATH, argv);
170		if (errno == ENOENT) {
171			warn("exec %s not found in %s", execname,
172			    _PATH_SYSPATH);
173		}
174		exit(1);
175	default:				/* Parent. */
176		if (waitpid(pid, &status, 0) < 0) {
177			warn("waitpid");
178			return (1);
179		}
180
181		if (WIFEXITED(status)) {
182			if (WEXITSTATUS(status) != 0)
183				return (WEXITSTATUS(status));
184		} else if (WIFSIGNALED(status)) {
185			warnx("%s: %s", name, sys_siglist[WTERMSIG(status)]);
186			return (1);
187		}
188		break;
189	}
190
191	return (0);
192}
193
194static int
195specified_ro(const char *arg)
196{
197	char *optbuf, *opt;
198	int ret = 0;
199
200	optbuf = strdup(arg);
201	if (optbuf == NULL)
202		 err(1, NULL);
203
204	for (opt = optbuf; (opt = strtok(opt, ",")) != NULL; opt = NULL) {
205		if (strcmp(opt, "ro") == 0) {
206			ret = 1;
207			break;
208		}
209	}
210	free(optbuf);
211	return (ret);
212}
213
214static void
215restart_mountd(void)
216{
217	struct pidfh *pfh;
218	pid_t mountdpid;
219
220	pfh = pidfile_open(_PATH_MOUNTDPID, 0600, &mountdpid);
221	if (pfh != NULL) {
222		/* Mountd is not running. */
223		pidfile_remove(pfh);
224		return;
225	}
226	if (errno != EEXIST) {
227		/* Cannot open pidfile for some reason. */
228		return;
229	}
230	/* We have mountd(8) PID in mountdpid varible, let's signal it. */
231	if (kill(mountdpid, SIGHUP) == -1)
232		err(1, "signal mountd");
233}
234
235int
236main(int argc, char *argv[])
237{
238	const char *mntfromname, **vfslist, *vfstype;
239	struct fstab *fs;
240	struct statfs *mntbuf;
241	int all, ch, i, init_flags, late, mntsize, rval, have_fstab, ro;
242	char *cp, *ep, *options;
243
244	all = init_flags = late = 0;
245	ro = 0;
246	options = NULL;
247	vfslist = NULL;
248	vfstype = "ufs";
249	while ((ch = getopt(argc, argv, "adF:flo:prt:uvw")) != -1)
250		switch (ch) {
251		case 'a':
252			all = 1;
253			break;
254		case 'd':
255			debug = 1;
256			break;
257		case 'F':
258			setfstab(optarg);
259			break;
260		case 'f':
261			init_flags |= MNT_FORCE;
262			break;
263		case 'l':
264			late = 1;
265			break;
266		case 'o':
267			if (*optarg) {
268				options = catopt(options, optarg);
269				if (specified_ro(optarg))
270					ro = 1;
271			}
272			break;
273		case 'p':
274			fstab_style = 1;
275			verbose = 1;
276			break;
277		case 'r':
278			options = catopt(options, "ro");
279			ro = 1;
280			break;
281		case 't':
282			if (vfslist != NULL)
283				errx(1, "only one -t option may be specified");
284			vfslist = makevfslist(optarg);
285			vfstype = optarg;
286			break;
287		case 'u':
288			init_flags |= MNT_UPDATE;
289			break;
290		case 'v':
291			verbose = 1;
292			break;
293		case 'w':
294			options = catopt(options, "noro");
295			break;
296		case '?':
297		default:
298			usage();
299			/* NOTREACHED */
300		}
301	argc -= optind;
302	argv += optind;
303
304#define	BADTYPE(type)							\
305	(strcmp(type, FSTAB_RO) &&					\
306	    strcmp(type, FSTAB_RW) && strcmp(type, FSTAB_RQ))
307
308	if ((init_flags & MNT_UPDATE) && (ro == 0))
309		options = catopt(options, "noro");
310
311	rval = 0;
312	switch (argc) {
313	case 0:
314		if ((mntsize = getmntinfo(&mntbuf, MNT_NOWAIT)) == 0)
315			err(1, "getmntinfo");
316		if (all) {
317			while ((fs = getfsent()) != NULL) {
318				if (BADTYPE(fs->fs_type))
319					continue;
320				if (checkvfsname(fs->fs_vfstype, vfslist))
321					continue;
322				if (hasopt(fs->fs_mntops, "noauto"))
323					continue;
324				if (hasopt(fs->fs_mntops, "late") && !late)
325					continue;
326				if (!(init_flags & MNT_UPDATE) &&
327				    ismounted(fs, mntbuf, mntsize))
328					continue;
329				options = update_options(options, fs->fs_mntops,
330				    mntbuf->f_flags);
331				if (mountfs(fs->fs_vfstype, fs->fs_spec,
332				    fs->fs_file, init_flags, options,
333				    fs->fs_mntops))
334					rval = 1;
335			}
336		} else if (fstab_style) {
337			for (i = 0; i < mntsize; i++) {
338				if (checkvfsname(mntbuf[i].f_fstypename, vfslist))
339					continue;
340				putfsent(&mntbuf[i]);
341			}
342		} else {
343			for (i = 0; i < mntsize; i++) {
344				if (checkvfsname(mntbuf[i].f_fstypename,
345				    vfslist))
346					continue;
347				prmount(&mntbuf[i]);
348			}
349		}
350		exit(rval);
351	case 1:
352		if (vfslist != NULL)
353			usage();
354
355		rmslashes(*argv, *argv);
356		if (init_flags & MNT_UPDATE) {
357			mntfromname = NULL;
358			have_fstab = 0;
359			if ((mntbuf = getmntpt(*argv)) == NULL)
360				errx(1, "not currently mounted %s", *argv);
361			/*
362			 * Only get the mntflags from fstab if both mntpoint
363			 * and mntspec are identical. Also handle the special
364			 * case where just '/' is mounted and 'spec' is not
365			 * identical with the one from fstab ('/dev' is missing
366			 * in the spec-string at boot-time).
367			 */
368			if ((fs = getfsfile(mntbuf->f_mntonname)) != NULL) {
369				if (strcmp(fs->fs_spec,
370				    mntbuf->f_mntfromname) == 0 &&
371				    strcmp(fs->fs_file,
372				    mntbuf->f_mntonname) == 0) {
373					have_fstab = 1;
374					mntfromname = mntbuf->f_mntfromname;
375				} else if (argv[0][0] == '/' &&
376				    argv[0][1] == '\0') {
377					fs = getfsfile("/");
378					have_fstab = 1;
379					mntfromname = fs->fs_spec;
380				}
381			}
382			if (have_fstab) {
383				options = update_options(options, fs->fs_mntops,
384				    mntbuf->f_flags);
385			} else {
386				mntfromname = mntbuf->f_mntfromname;
387				options = update_options(options, NULL,
388				    mntbuf->f_flags);
389			}
390			rval = mountfs(mntbuf->f_fstypename, mntfromname,
391			    mntbuf->f_mntonname, init_flags, options, 0);
392			break;
393		}
394		if ((fs = getfsfile(*argv)) == NULL &&
395		    (fs = getfsspec(*argv)) == NULL)
396			errx(1, "%s: unknown special file or file system",
397			    *argv);
398		if (BADTYPE(fs->fs_type))
399			errx(1, "%s has unknown file system type",
400			    *argv);
401		rval = mountfs(fs->fs_vfstype, fs->fs_spec, fs->fs_file,
402		    init_flags, options, fs->fs_mntops);
403		break;
404	case 2:
405		/*
406		 * If -t flag has not been specified, the path cannot be
407		 * found, spec contains either a ':' or a '@', then assume
408		 * that an NFS file system is being specified ala Sun.
409		 * Check if the hostname contains only allowed characters
410		 * to reduce false positives.  IPv6 addresses containing
411		 * ':' will be correctly parsed only if the separator is '@'.
412		 * The definition of a valid hostname is taken from RFC 1034.
413		 */
414		if (vfslist == NULL && ((ep = strchr(argv[0], '@')) != NULL ||
415		    (ep = strchr(argv[0], ':')) != NULL)) {
416			if (*ep == '@') {
417				cp = ep + 1;
418				ep = cp + strlen(cp);
419			} else
420				cp = argv[0];
421			while (cp != ep) {
422				if (!isdigit(*cp) && !isalpha(*cp) &&
423				    *cp != '.' && *cp != '-' && *cp != ':')
424					break;
425				cp++;
426			}
427			if (cp == ep)
428				vfstype = "nfs";
429		}
430		rval = mountfs(vfstype,
431		    argv[0], argv[1], init_flags, options, NULL);
432		break;
433	default:
434		usage();
435		/* NOTREACHED */
436	}
437
438	/*
439	 * If the mount was successfully, and done by root, tell mountd the
440	 * good news.
441	 */
442	if (rval == 0 && getuid() == 0)
443		restart_mountd();
444
445	exit(rval);
446}
447
448int
449ismounted(struct fstab *fs, struct statfs *mntbuf, int mntsize)
450{
451	char realfsfile[PATH_MAX];
452	int i;
453
454	if (fs->fs_file[0] == '/' && fs->fs_file[1] == '\0')
455		/* the root file system can always be remounted */
456		return (0);
457
458	/* The user may have specified a symlink in fstab, resolve the path */
459	if (realpath(fs->fs_file, realfsfile) == NULL) {
460		/* Cannot resolve the path, use original one */
461		strlcpy(realfsfile, fs->fs_file, sizeof(realfsfile));
462	}
463
464	for (i = mntsize - 1; i >= 0; --i)
465		if (strcmp(realfsfile, mntbuf[i].f_mntonname) == 0 &&
466		    (!isremountable(fs->fs_vfstype) ||
467		     strcmp(fs->fs_spec, mntbuf[i].f_mntfromname) == 0))
468			return (1);
469	return (0);
470}
471
472int
473isremountable(const char *vfsname)
474{
475	const char **cp;
476
477	for (cp = remountable_fs_names; *cp; cp++)
478		if (strcmp(*cp, vfsname) == 0)
479			return (1);
480	return (0);
481}
482
483int
484hasopt(const char *mntopts, const char *option)
485{
486	int negative, found;
487	char *opt, *optbuf;
488
489	if (option[0] == 'n' && option[1] == 'o') {
490		negative = 1;
491		option += 2;
492	} else
493		negative = 0;
494	optbuf = strdup(mntopts);
495	found = 0;
496	for (opt = optbuf; (opt = strtok(opt, ",")) != NULL; opt = NULL) {
497		if (opt[0] == 'n' && opt[1] == 'o') {
498			if (!strcasecmp(opt + 2, option))
499				found = negative;
500		} else if (!strcasecmp(opt, option))
501			found = !negative;
502	}
503	free(optbuf);
504	return (found);
505}
506
507static void
508append_arg(struct cpa *sa, char *arg)
509{
510	if (sa->c >= sa->m)
511		errx(1, "Cannot process more than %zd mount arguments", sa->m);
512
513	sa->a[++sa->c] = arg;
514}
515
516int
517mountfs(const char *vfstype, const char *spec, const char *name, int flags,
518	const char *options, const char *mntopts)
519{
520	struct cpa mnt_argv;
521	struct statfs sf;
522	int i, ret;
523	char *optbuf, execname[PATH_MAX], mntpath[PATH_MAX];
524
525	/* resolve the mountpoint with realpath(3) */
526	(void)checkpath(name, mntpath);
527	name = mntpath;
528
529	if (mntopts == NULL)
530		mntopts = "";
531	optbuf = catopt(strdup(mntopts), options);
532
533	if (strcmp(name, "/") == 0)
534		flags |= MNT_UPDATE;
535	if (flags & MNT_FORCE)
536		optbuf = catopt(optbuf, "force");
537	if (flags & MNT_RDONLY)
538		optbuf = catopt(optbuf, "ro");
539	/*
540	 * XXX
541	 * The mount_mfs (newfs) command uses -o to select the
542	 * optimization mode.  We don't pass the default "-o rw"
543	 * for that reason.
544	 */
545	if (flags & MNT_UPDATE)
546		optbuf = catopt(optbuf, "update");
547
548	/* Compatibility glue. */
549	if (strcmp(vfstype, "msdos") == 0) {
550		warnx(
551		    "Using \"-t msdosfs\", since \"-t msdos\" is deprecated.");
552		vfstype = "msdosfs";
553	}
554
555	/* Construct the name of the appropriate mount command */
556	(void)snprintf(execname, sizeof(execname), "mount_%s", vfstype);
557
558	mnt_argv.m = MAX_ARGS;
559	mnt_argv.c = -1;
560	append_arg(&mnt_argv, execname);
561	mangle(optbuf, &mnt_argv);
562	append_arg(&mnt_argv, strdup(spec));
563	append_arg(&mnt_argv, strdup(name));
564	append_arg(&mnt_argv, NULL);
565
566	if (debug) {
567		if (use_mountprog(vfstype))
568			printf("exec: mount_%s", vfstype);
569		else
570			printf("mount -t %s", vfstype);
571		for (i = 1; i < mnt_argv.c; i++)
572			(void)printf(" %s", mnt_argv.a[i]);
573		(void)printf("\n");
574		return (0);
575	}
576
577	if (use_mountprog(vfstype)) {
578		ret = exec_mountprog(name, execname, mnt_argv.a);
579	} else {
580		ret = mount_fs(vfstype, mnt_argv.c, mnt_argv.a);
581	}
582
583	free(optbuf);
584
585	if (verbose) {
586		if (statfs(name, &sf) < 0) {
587			warn("statfs %s", name);
588			return (1);
589		}
590		if (fstab_style)
591			putfsent(&sf);
592		else
593			prmount(&sf);
594	}
595
596	return (ret);
597}
598
599void
600prmount(struct statfs *sfp)
601{
602	int flags;
603	unsigned int i;
604	struct opt *o;
605	struct passwd *pw;
606
607	(void)printf("%s on %s (%s", sfp->f_mntfromname, sfp->f_mntonname,
608	    sfp->f_fstypename);
609
610	flags = sfp->f_flags & MNT_VISFLAGMASK;
611	for (o = optnames; flags && o->o_opt; o++)
612		if (flags & o->o_opt) {
613			(void)printf(", %s", o->o_name);
614			flags &= ~o->o_opt;
615		}
616	/*
617	 * Inform when file system is mounted by an unprivileged user
618	 * or privileged non-root user.
619	 */
620	if ((flags & MNT_USER) != 0 || sfp->f_owner != 0) {
621		(void)printf(", mounted by ");
622		if ((pw = getpwuid(sfp->f_owner)) != NULL)
623			(void)printf("%s", pw->pw_name);
624		else
625			(void)printf("%d", sfp->f_owner);
626	}
627	if (verbose) {
628		if (sfp->f_syncwrites != 0 || sfp->f_asyncwrites != 0)
629			(void)printf(", writes: sync %ju async %ju",
630			    (uintmax_t)sfp->f_syncwrites,
631			    (uintmax_t)sfp->f_asyncwrites);
632		if (sfp->f_syncreads != 0 || sfp->f_asyncreads != 0)
633			(void)printf(", reads: sync %ju async %ju",
634			    (uintmax_t)sfp->f_syncreads,
635			    (uintmax_t)sfp->f_asyncreads);
636		if (sfp->f_fsid.val[0] != 0 || sfp->f_fsid.val[1] != 0) {
637			printf(", fsid ");
638			for (i = 0; i < sizeof(sfp->f_fsid); i++)
639				printf("%02x", ((u_char *)&sfp->f_fsid)[i]);
640		}
641	}
642	(void)printf(")\n");
643}
644
645struct statfs *
646getmntpt(const char *name)
647{
648	struct statfs *mntbuf;
649	int i, mntsize;
650
651	mntsize = getmntinfo(&mntbuf, MNT_NOWAIT);
652	for (i = mntsize - 1; i >= 0; i--) {
653		if (strcmp(mntbuf[i].f_mntfromname, name) == 0 ||
654		    strcmp(mntbuf[i].f_mntonname, name) == 0)
655			return (&mntbuf[i]);
656	}
657	return (NULL);
658}
659
660char *
661catopt(char *s0, const char *s1)
662{
663	size_t i;
664	char *cp;
665
666	if (s1 == NULL || *s1 == '\0')
667		return (s0);
668
669	if (s0 && *s0) {
670		i = strlen(s0) + strlen(s1) + 1 + 1;
671		if ((cp = malloc(i)) == NULL)
672			errx(1, "malloc failed");
673		(void)snprintf(cp, i, "%s,%s", s0, s1);
674	} else
675		cp = strdup(s1);
676
677	if (s0)
678		free(s0);
679	return (cp);
680}
681
682void
683mangle(char *options, struct cpa *a)
684{
685	char *p, *s;
686
687	for (s = options; (p = strsep(&s, ",")) != NULL;)
688		if (*p != '\0') {
689			if (strcmp(p, "noauto") == 0) {
690				/*
691				 * Do not pass noauto option to nmount().
692				 * or external mount program.  noauto is
693				 * only used to prevent mounting a filesystem
694				 * when 'mount -a' is specified, and is
695				 * not a real mount option.
696				 */
697				continue;
698			} else if (strcmp(p, "late") == 0) {
699				/*
700				 * "late" is used to prevent certain file
701				 * systems from being mounted before late
702				 * in the boot cycle; for instance,
703				 * loopback NFS mounts can't be mounted
704				 * before mountd starts.
705				 */
706				continue;
707			} else if (strcmp(p, "userquota") == 0) {
708				continue;
709			} else if (strncmp(p, userquotaeq,
710			    sizeof(userquotaeq) - 1) == 0) {
711				continue;
712			} else if (strcmp(p, "groupquota") == 0) {
713				continue;
714			} else if (strncmp(p, groupquotaeq,
715			    sizeof(groupquotaeq) - 1) == 0) {
716				continue;
717			} else if (*p == '-') {
718				append_arg(a, p);
719				p = strchr(p, '=');
720				if (p != NULL) {
721					*p = '\0';
722					append_arg(a, p + 1);
723				}
724			} else {
725				append_arg(a, strdup("-o"));
726				append_arg(a, p);
727			}
728		}
729}
730
731
732char *
733update_options(char *opts, char *fstab, int curflags)
734{
735	char *o, *p;
736	char *cur;
737	char *expopt, *newopt, *tmpopt;
738
739	if (opts == NULL)
740		return (strdup(""));
741
742	/* remove meta options from list */
743	remopt(fstab, MOUNT_META_OPTION_FSTAB);
744	remopt(fstab, MOUNT_META_OPTION_CURRENT);
745	cur = flags2opts(curflags);
746
747	/*
748	 * Expand all meta-options passed to us first.
749	 */
750	expopt = NULL;
751	for (p = opts; (o = strsep(&p, ",")) != NULL;) {
752		if (strcmp(MOUNT_META_OPTION_FSTAB, o) == 0)
753			expopt = catopt(expopt, fstab);
754		else if (strcmp(MOUNT_META_OPTION_CURRENT, o) == 0)
755			expopt = catopt(expopt, cur);
756		else
757			expopt = catopt(expopt, o);
758	}
759	free(cur);
760	free(opts);
761
762	/*
763	 * Remove previous contradictory arguments. Given option "foo" we
764	 * remove all the "nofoo" options. Given "nofoo" we remove "nonofoo"
765	 * and "foo" - so we can deal with possible options like "notice".
766	 */
767	newopt = NULL;
768	for (p = expopt; (o = strsep(&p, ",")) != NULL;) {
769		if ((tmpopt = malloc( strlen(o) + 2 + 1 )) == NULL)
770			errx(1, "malloc failed");
771
772		strcpy(tmpopt, "no");
773		strcat(tmpopt, o);
774		remopt(newopt, tmpopt);
775		free(tmpopt);
776
777		if (strncmp("no", o, 2) == 0)
778			remopt(newopt, o+2);
779
780		newopt = catopt(newopt, o);
781	}
782	free(expopt);
783
784	return (newopt);
785}
786
787void
788remopt(char *string, const char *opt)
789{
790	char *o, *p, *r;
791
792	if (string == NULL || *string == '\0' || opt == NULL || *opt == '\0')
793		return;
794
795	r = string;
796
797	for (p = string; (o = strsep(&p, ",")) != NULL;) {
798		if (strcmp(opt, o) != 0) {
799			if (*r == ',' && *o != '\0')
800				r++;
801			while ((*r++ = *o++) != '\0')
802			    ;
803			*--r = ',';
804		}
805	}
806	*r = '\0';
807}
808
809void
810usage(void)
811{
812
813	(void)fprintf(stderr, "%s\n%s\n%s\n",
814"usage: mount [-adflpruvw] [-F fstab] [-o options] [-t ufs | external_type]",
815"       mount [-dfpruvw] special | node",
816"       mount [-dfpruvw] [-o options] [-t ufs | external_type] special node");
817	exit(1);
818}
819
820void
821putfsent(struct statfs *ent)
822{
823	struct fstab *fst;
824	char *opts;
825	int l;
826
827	opts = flags2opts(ent->f_flags);
828
829	if (strncmp(ent->f_mntfromname, "<below>", 7) == 0 ||
830	    strncmp(ent->f_mntfromname, "<above>", 7) == 0) {
831		strcpy(ent->f_mntfromname, (strnstr(ent->f_mntfromname, ":", 8)
832		    +1));
833	}
834
835	/*
836	 * "rw" is not a real mount option; this is why we print NULL as "rw"
837	 * if opts is still NULL here.
838	 */
839	l = strlen(ent->f_mntfromname);
840	printf("%s%s%s%s", ent->f_mntfromname,
841	    l < 8 ? "\t" : "",
842	    l < 16 ? "\t" : "",
843	    l < 24 ? "\t" : " ");
844	l = strlen(ent->f_mntonname);
845	printf("%s%s%s%s", ent->f_mntonname,
846	    l < 8 ? "\t" : "",
847	    l < 16 ? "\t" : "",
848	    l < 24 ? "\t" : " ");
849	printf("%s\t", ent->f_fstypename);
850	if (opts == NULL) {
851		printf("%s\t", "rw");
852	} else {
853		l = strlen(opts);
854		printf("%s%s", opts,
855		    l < 8 ? "\t" : " ");
856	}
857	free(opts);
858
859	if ((fst = getfsspec(ent->f_mntfromname)))
860		printf("\t%u %u\n", fst->fs_freq, fst->fs_passno);
861	else if ((fst = getfsfile(ent->f_mntonname)))
862		printf("\t%u %u\n", fst->fs_freq, fst->fs_passno);
863	else if (strcmp(ent->f_fstypename, "ufs") == 0) {
864		if (strcmp(ent->f_mntonname, "/") == 0)
865			printf("\t1 1\n");
866		else
867			printf("\t2 2\n");
868	} else
869		printf("\t0 0\n");
870}
871
872
873char *
874flags2opts(int flags)
875{
876	char *res;
877
878	res = NULL;
879
880	if (flags & MNT_RDONLY)		res = catopt(res, "ro");
881	if (flags & MNT_SYNCHRONOUS)	res = catopt(res, "sync");
882	if (flags & MNT_NOEXEC)		res = catopt(res, "noexec");
883	if (flags & MNT_NOSUID)		res = catopt(res, "nosuid");
884	if (flags & MNT_UNION)		res = catopt(res, "union");
885	if (flags & MNT_ASYNC)		res = catopt(res, "async");
886	if (flags & MNT_NOATIME)	res = catopt(res, "noatime");
887	if (flags & MNT_NOCLUSTERR)	res = catopt(res, "noclusterr");
888	if (flags & MNT_NOCLUSTERW)	res = catopt(res, "noclusterw");
889	if (flags & MNT_NOSYMFOLLOW)	res = catopt(res, "nosymfollow");
890	if (flags & MNT_SUIDDIR)	res = catopt(res, "suiddir");
891	if (flags & MNT_MULTILABEL)	res = catopt(res, "multilabel");
892	if (flags & MNT_ACLS)		res = catopt(res, "acls");
893
894	return (res);
895}
896