xref: /freebsd/sbin/mount/mount.c (revision ae83180158c4c937f170e31eff311b18c0286a93)
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  * 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, 1994\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[] = "@(#)mount.c	8.25 (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 #include <sys/stat.h>
51 #include <sys/wait.h>
52 
53 #include <ctype.h>
54 #include <err.h>
55 #include <errno.h>
56 #include <fstab.h>
57 #include <pwd.h>
58 #include <signal.h>
59 #include <stdio.h>
60 #include <stdlib.h>
61 #include <string.h>
62 #include <unistd.h>
63 
64 #include "extern.h"
65 #include "mntopts.h"
66 #include "pathnames.h"
67 
68 /* `meta' options */
69 #define MOUNT_META_OPTION_FSTAB		"fstab"
70 #define MOUNT_META_OPTION_CURRENT	"current"
71 
72 int debug, fstab_style, verbose;
73 
74 char   *catopt(char *, const char *);
75 struct statfs *getmntpt(const char *);
76 int	hasopt(const char *, const char *);
77 int	ismounted(struct fstab *, struct statfs *, int);
78 int	isremountable(const char *);
79 void	mangle(char *, int *, const char **);
80 char   *update_options(char *, char *, int);
81 int	mountfs(const char *, const char *, const char *,
82 			int, const char *, const char *);
83 void	remopt(char *, const char *);
84 void	prmount(struct statfs *);
85 void	putfsent(const struct statfs *);
86 void	usage(void);
87 char   *flags2opts(int);
88 
89 /* Map from mount options to printable formats. */
90 static struct opt {
91 	int o_opt;
92 	const char *o_name;
93 } optnames[] = {
94 	{ MNT_ASYNC,		"asynchronous" },
95 	{ MNT_EXPORTED,		"NFS exported" },
96 	{ MNT_LOCAL,		"local" },
97 	{ MNT_NOATIME,		"noatime" },
98 	{ MNT_NODEV,		"nodev" },
99 	{ MNT_NOEXEC,		"noexec" },
100 	{ MNT_NOSUID,		"nosuid" },
101 	{ MNT_NOSYMFOLLOW,	"nosymfollow" },
102 	{ MNT_QUOTA,		"with quotas" },
103 	{ MNT_RDONLY,		"read-only" },
104 	{ MNT_SYNCHRONOUS,	"synchronous" },
105 	{ MNT_UNION,		"union" },
106 	{ MNT_NOCLUSTERR,	"noclusterr" },
107 	{ MNT_NOCLUSTERW,	"noclusterw" },
108 	{ MNT_SUIDDIR,		"suiddir" },
109 	{ MNT_SOFTDEP,		"soft-updates" },
110 	{ MNT_MULTILABEL,	"multilabel" },
111 	{ 0, NULL }
112 };
113 
114 /*
115  * List of VFS types that can be remounted without becoming mounted on top
116  * of each other.
117  * XXX Is this list correct?
118  */
119 static const char *
120 remountable_fs_names[] = {
121 	"ufs", "ffs", "ext2fs",
122 	0
123 };
124 
125 int
126 main(argc, argv)
127 	int argc;
128 	char * const argv[];
129 {
130 	const char *mntfromname, **vfslist, *vfstype;
131 	struct fstab *fs;
132 	struct statfs *mntbuf;
133 	FILE *mountdfp;
134 	pid_t pid;
135 	int all, ch, i, init_flags, mntsize, rval, have_fstab;
136 	char *cp, *ep, *options;
137 
138 	all = init_flags = 0;
139 	options = NULL;
140 	vfslist = NULL;
141 	vfstype = "ufs";
142 	while ((ch = getopt(argc, argv, "adfo:prwt:uv")) != -1)
143 		switch (ch) {
144 		case 'a':
145 			all = 1;
146 			break;
147 		case 'd':
148 			debug = 1;
149 			break;
150 		case 'f':
151 			init_flags |= MNT_FORCE;
152 			break;
153 		case 'o':
154 			if (*optarg)
155 				options = catopt(options, optarg);
156 			break;
157 		case 'p':
158 			fstab_style = 1;
159 			verbose = 1;
160 			break;
161 		case 'r':
162 			options = catopt(options, "ro");
163 			break;
164 		case 't':
165 			if (vfslist != NULL)
166 				errx(1, "only one -t option may be specified");
167 			vfslist = makevfslist(optarg);
168 			vfstype = optarg;
169 			break;
170 		case 'u':
171 			init_flags |= MNT_UPDATE;
172 			break;
173 		case 'v':
174 			verbose = 1;
175 			break;
176 		case 'w':
177 			options = catopt(options, "noro");
178 			break;
179 		case '?':
180 		default:
181 			usage();
182 			/* NOTREACHED */
183 		}
184 	argc -= optind;
185 	argv += optind;
186 
187 #define	BADTYPE(type)							\
188 	(strcmp(type, FSTAB_RO) &&					\
189 	    strcmp(type, FSTAB_RW) && strcmp(type, FSTAB_RQ))
190 
191 	rval = 0;
192 	switch (argc) {
193 	case 0:
194 		if ((mntsize = getmntinfo(&mntbuf, MNT_NOWAIT)) == 0)
195 			err(1, "getmntinfo");
196 		if (all) {
197 			while ((fs = getfsent()) != NULL) {
198 				if (BADTYPE(fs->fs_type))
199 					continue;
200 				if (checkvfsname(fs->fs_vfstype, vfslist))
201 					continue;
202 				if (hasopt(fs->fs_mntops, "noauto"))
203 					continue;
204 				if (!(init_flags & MNT_UPDATE) &&
205 				    ismounted(fs, mntbuf, mntsize))
206 					continue;
207 				if (mountfs(fs->fs_vfstype, fs->fs_spec,
208 				    fs->fs_file, init_flags, options,
209 				    fs->fs_mntops))
210 					rval = 1;
211 			}
212 		} else if (fstab_style) {
213 			for (i = 0; i < mntsize; i++) {
214 				if (checkvfsname(mntbuf[i].f_fstypename, vfslist))
215 					continue;
216 				putfsent(&mntbuf[i]);
217 			}
218 		} else {
219 			for (i = 0; i < mntsize; i++) {
220 				if (checkvfsname(mntbuf[i].f_fstypename,
221 				    vfslist))
222 					continue;
223 				prmount(&mntbuf[i]);
224 			}
225 		}
226 		exit(rval);
227 	case 1:
228 		if (vfslist != NULL)
229 			usage();
230 
231 		if (init_flags & MNT_UPDATE) {
232 			mntfromname = NULL;
233 			have_fstab = 0;
234 			if ((mntbuf = getmntpt(*argv)) == NULL)
235 				errx(1, "not currently mounted %s", *argv);
236 			/*
237 			 * Only get the mntflags from fstab if both mntpoint
238 			 * and mntspec are identical. Also handle the special
239 			 * case where just '/' is mounted and 'spec' is not
240 			 * identical with the one from fstab ('/dev' is missing
241 			 * in the spec-string at boot-time).
242 			 */
243 			if ((fs = getfsfile(mntbuf->f_mntonname)) != NULL) {
244 				if (strcmp(fs->fs_spec,
245 				    mntbuf->f_mntfromname) == 0 &&
246 				    strcmp(fs->fs_file,
247 				    mntbuf->f_mntonname) == 0) {
248 					have_fstab = 1;
249 					mntfromname = mntbuf->f_mntfromname;
250 				} else if (argv[0][0] == '/' &&
251 				    argv[0][1] == '\0') {
252 					fs = getfsfile("/");
253 					have_fstab = 1;
254 					mntfromname = fs->fs_spec;
255 				}
256 			}
257 			if (have_fstab) {
258 				options = update_options(options, fs->fs_mntops,
259 				    mntbuf->f_flags);
260 			} else {
261 				mntfromname = mntbuf->f_mntfromname;
262 				options = update_options(options, NULL,
263 				    mntbuf->f_flags);
264 			}
265 			rval = mountfs(mntbuf->f_fstypename, mntfromname,
266 			    mntbuf->f_mntonname, init_flags, options, 0);
267 			break;
268 		}
269 		rmslashes(*argv, *argv);
270 		if ((fs = getfsfile(*argv)) == NULL &&
271 		    (fs = getfsspec(*argv)) == NULL)
272 			errx(1, "%s: unknown special file or filesystem",
273 			    *argv);
274 		if (BADTYPE(fs->fs_type))
275 			errx(1, "%s has unknown filesystem type",
276 			    *argv);
277 		rval = mountfs(fs->fs_vfstype, fs->fs_spec, fs->fs_file,
278 		    init_flags, options, fs->fs_mntops);
279 		break;
280 	case 2:
281 		/*
282 		 * If -t flag has not been specified, the path cannot be
283 		 * found, spec contains either a ':' or a '@', then assume
284 		 * that an NFS filesystem is being specified ala Sun.
285 		 * Check if the hostname contains only allowed characters
286 		 * to reduce false positives.  IPv6 addresses containing
287 		 * ':' will be correctly parsed only if the separator is '@'.
288 		 * The definition of a valid hostname is taken from RFC 1034.
289 		 */
290 		if (vfslist == NULL && ((ep = strchr(argv[0], '@')) != NULL) ||
291 		    ((ep = strchr(argv[0], ':')) != NULL)) {
292 			if (*ep == '@') {
293 				cp = ep + 1;
294 				ep = cp + strlen(cp);
295 			} else
296 				cp = argv[0];
297 			while (cp != ep) {
298 				if (!isdigit(*cp) && !isalpha(*cp) &&
299 				    *cp != '.' && *cp != '-' && *cp != ':')
300 					break;
301 				cp++;
302 			}
303 			if (cp == ep)
304 				vfstype = "nfs";
305 		}
306 		rval = mountfs(vfstype,
307 		    argv[0], argv[1], init_flags, options, NULL);
308 		break;
309 	default:
310 		usage();
311 		/* NOTREACHED */
312 	}
313 
314 	/*
315 	 * If the mount was successfully, and done by root, tell mountd the
316 	 * good news.  Pid checks are probably unnecessary, but don't hurt.
317 	 */
318 	if (rval == 0 && getuid() == 0 &&
319 	    (mountdfp = fopen(_PATH_MOUNTDPID, "r")) != NULL) {
320 		if (fscanf(mountdfp, "%d", &pid) == 1 &&
321 		     pid > 0 && kill(pid, SIGHUP) == -1 && errno != ESRCH)
322 			err(1, "signal mountd");
323 		(void)fclose(mountdfp);
324 	}
325 
326 	exit(rval);
327 }
328 
329 int
330 ismounted(fs, mntbuf, mntsize)
331 	struct fstab *fs;
332 	struct statfs *mntbuf;
333 	int mntsize;
334 {
335 	int i;
336 
337 	if (fs->fs_file[0] == '/' && fs->fs_file[1] == '\0')
338 		/* the root filesystem can always be remounted */
339 		return (0);
340 
341 	for (i = mntsize - 1; i >= 0; --i)
342 		if (strcmp(fs->fs_file, mntbuf[i].f_mntonname) == 0 &&
343 		    (!isremountable(fs->fs_vfstype) ||
344 		     strcmp(fs->fs_spec, mntbuf[i].f_mntfromname) == 0))
345 			return (1);
346 	return (0);
347 }
348 
349 int
350 isremountable(vfsname)
351 	const char *vfsname;
352 {
353 	const char **cp;
354 
355 	for (cp = remountable_fs_names; *cp; cp++)
356 		if (strcmp(*cp, vfsname) == 0)
357 			return (1);
358 	return (0);
359 }
360 
361 int
362 hasopt(mntopts, option)
363 	const char *mntopts, *option;
364 {
365 	int negative, found;
366 	char *opt, *optbuf;
367 
368 	if (option[0] == 'n' && option[1] == 'o') {
369 		negative = 1;
370 		option += 2;
371 	} else
372 		negative = 0;
373 	optbuf = strdup(mntopts);
374 	found = 0;
375 	for (opt = optbuf; (opt = strtok(opt, ",")) != NULL; opt = NULL) {
376 		if (opt[0] == 'n' && opt[1] == 'o') {
377 			if (!strcasecmp(opt + 2, option))
378 				found = negative;
379 		} else if (!strcasecmp(opt, option))
380 			found = !negative;
381 	}
382 	free(optbuf);
383 	return (found);
384 }
385 
386 int
387 mountfs(vfstype, spec, name, flags, options, mntopts)
388 	const char *vfstype, *spec, *name, *options, *mntopts;
389 	int flags;
390 {
391 	/* List of directories containing mount_xxx subcommands. */
392 	static const char *edirs[] = {
393 		_PATH_SBIN,
394 		_PATH_USRSBIN,
395 		NULL
396 	};
397 	const char *argv[100], **edir;
398 	struct statfs sf;
399 	pid_t pid;
400 	int argc, i, status;
401 	char *optbuf, execname[MAXPATHLEN + 1], mntpath[MAXPATHLEN];
402 
403 #if __GNUC__
404 	(void)&optbuf;
405 	(void)&name;
406 #endif
407 
408 	/* resolve the mountpoint with realpath(3) */
409 	(void)checkpath(name, mntpath);
410 	name = mntpath;
411 
412 	if (mntopts == NULL)
413 		mntopts = "";
414 	if (options == NULL) {
415 		if (*mntopts == '\0') {
416 			options = "rw";
417 		} else {
418 			options = mntopts;
419 			mntopts = "";
420 		}
421 	}
422 	optbuf = catopt(strdup(mntopts), options);
423 
424 	if (strcmp(name, "/") == 0)
425 		flags |= MNT_UPDATE;
426 	if (flags & MNT_FORCE)
427 		optbuf = catopt(optbuf, "force");
428 	if (flags & MNT_RDONLY)
429 		optbuf = catopt(optbuf, "ro");
430 	/*
431 	 * XXX
432 	 * The mount_mfs (newfs) command uses -o to select the
433 	 * optimization mode.  We don't pass the default "-o rw"
434 	 * for that reason.
435 	 */
436 	if (flags & MNT_UPDATE)
437 		optbuf = catopt(optbuf, "update");
438 
439 	/* Compatibility glue. */
440 	if (strcmp(vfstype, "msdos") == 0)
441 		vfstype = "msdosfs";
442 
443 	argc = 0;
444 	argv[argc++] = vfstype;
445 	mangle(optbuf, &argc, argv);
446 	argv[argc++] = spec;
447 	argv[argc++] = name;
448 	argv[argc] = NULL;
449 
450 	if (debug) {
451 		(void)printf("exec: mount_%s", vfstype);
452 		for (i = 1; i < argc; i++)
453 			(void)printf(" %s", argv[i]);
454 		(void)printf("\n");
455 		return (0);
456 	}
457 
458 	switch (pid = fork()) {
459 	case -1:				/* Error. */
460 		warn("fork");
461 		free(optbuf);
462 		return (1);
463 	case 0:					/* Child. */
464 		if (strcmp(vfstype, "ufs") == 0)
465 			exit(mount_ufs(argc, (char * const *) argv));
466 
467 		/* Go find an executable. */
468 		for (edir = edirs; *edir; edir++) {
469 			(void)snprintf(execname,
470 			    sizeof(execname), "%s/mount_%s", *edir, vfstype);
471 			execv(execname, (char * const *)argv);
472 		}
473 		if (errno == ENOENT) {
474 			int len = 0;
475 			char *cp;
476 			for (edir = edirs; *edir; edir++)
477 				len += strlen(*edir) + 2;	/* ", " */
478 			if ((cp = malloc(len)) == NULL)
479 				errx(1, "malloc failed");
480 			cp[0] = '\0';
481 			for (edir = edirs; *edir; edir++) {
482 				strcat(cp, *edir);
483 				if (edir[1] != NULL)
484 					strcat(cp, ", ");
485 			}
486 			warn("exec mount_%s not found in %s", vfstype, cp);
487 		}
488 		exit(1);
489 		/* NOTREACHED */
490 	default:				/* Parent. */
491 		free(optbuf);
492 
493 		if (waitpid(pid, &status, 0) < 0) {
494 			warn("waitpid");
495 			return (1);
496 		}
497 
498 		if (WIFEXITED(status)) {
499 			if (WEXITSTATUS(status) != 0)
500 				return (WEXITSTATUS(status));
501 		} else if (WIFSIGNALED(status)) {
502 			warnx("%s: %s", name, sys_siglist[WTERMSIG(status)]);
503 			return (1);
504 		}
505 
506 		if (verbose) {
507 			if (statfs(name, &sf) < 0) {
508 				warn("statfs %s", name);
509 				return (1);
510 			}
511 			if (fstab_style)
512 				putfsent(&sf);
513 			else
514 				prmount(&sf);
515 		}
516 		break;
517 	}
518 
519 	return (0);
520 }
521 
522 void
523 prmount(sfp)
524 	struct statfs *sfp;
525 {
526 	int flags;
527 	struct opt *o;
528 	struct passwd *pw;
529 
530 	(void)printf("%s on %s (%s", sfp->f_mntfromname, sfp->f_mntonname,
531 	    sfp->f_fstypename);
532 
533 	flags = sfp->f_flags & MNT_VISFLAGMASK;
534 	for (o = optnames; flags && o->o_opt; o++)
535 		if (flags & o->o_opt) {
536 			(void)printf(", %s", o->o_name);
537 			flags &= ~o->o_opt;
538 		}
539 	if (sfp->f_owner) {
540 		(void)printf(", mounted by ");
541 		if ((pw = getpwuid(sfp->f_owner)) != NULL)
542 			(void)printf("%s", pw->pw_name);
543 		else
544 			(void)printf("%d", sfp->f_owner);
545 	}
546 	if (verbose) {
547 		if (sfp->f_syncwrites != 0 || sfp->f_asyncwrites != 0)
548 			(void)printf(", writes: sync %ld async %ld",
549 			    sfp->f_syncwrites, sfp->f_asyncwrites);
550 		if (sfp->f_syncreads != 0 || sfp->f_asyncreads != 0)
551 			(void)printf(", reads: sync %ld async %ld",
552 			    sfp->f_syncreads, sfp->f_asyncreads);
553 	}
554 	(void)printf(")\n");
555 }
556 
557 struct statfs *
558 getmntpt(name)
559 	const char *name;
560 {
561 	struct statfs *mntbuf;
562 	int i, mntsize;
563 
564 	mntsize = getmntinfo(&mntbuf, MNT_NOWAIT);
565 	for (i = mntsize - 1; i >= 0; i--) {
566 		if (strcmp(mntbuf[i].f_mntfromname, name) == 0 ||
567 		    strcmp(mntbuf[i].f_mntonname, name) == 0)
568 			return (&mntbuf[i]);
569 	}
570 	return (NULL);
571 }
572 
573 char *
574 catopt(s0, s1)
575 	char *s0;
576 	const char *s1;
577 {
578 	size_t i;
579 	char *cp;
580 
581 	if (s1 == NULL || *s1 == '\0')
582 		return s0;
583 
584 	if (s0 && *s0) {
585 		i = strlen(s0) + strlen(s1) + 1 + 1;
586 		if ((cp = malloc(i)) == NULL)
587 			errx(1, "malloc failed");
588 		(void)snprintf(cp, i, "%s,%s", s0, s1);
589 	} else
590 		cp = strdup(s1);
591 
592 	if (s0)
593 		free(s0);
594 	return (cp);
595 }
596 
597 void
598 mangle(options, argcp, argv)
599 	char *options;
600 	int *argcp;
601 	const char **argv;
602 {
603 	char *p, *s;
604 	int argc;
605 
606 	argc = *argcp;
607 	for (s = options; (p = strsep(&s, ",")) != NULL;)
608 		if (*p != '\0') {
609 			if (*p == '-') {
610 				argv[argc++] = p;
611 				p = strchr(p, '=');
612 				if (p) {
613 					*p = '\0';
614 					argv[argc++] = p+1;
615 				}
616 			} else if (strcmp(p, "rw") != 0) {
617 				argv[argc++] = "-o";
618 				argv[argc++] = p;
619 			}
620 		}
621 
622 	*argcp = argc;
623 }
624 
625 
626 char *
627 update_options(opts, fstab, curflags)
628 	char *opts;
629 	char *fstab;
630 	int curflags;
631 {
632 	char *o, *p;
633 	char *cur;
634 	char *expopt, *newopt, *tmpopt;
635 
636 	if (opts == NULL)
637 		return strdup("");
638 
639 	/* remove meta options from list */
640 	remopt(fstab, MOUNT_META_OPTION_FSTAB);
641 	remopt(fstab, MOUNT_META_OPTION_CURRENT);
642 	cur = flags2opts(curflags);
643 
644 	/*
645 	 * Expand all meta-options passed to us first.
646 	 */
647 	expopt = NULL;
648 	for (p = opts; (o = strsep(&p, ",")) != NULL;) {
649 		if (strcmp(MOUNT_META_OPTION_FSTAB, o) == 0)
650 			expopt = catopt(expopt, fstab);
651 		else if (strcmp(MOUNT_META_OPTION_CURRENT, o) == 0)
652 			expopt = catopt(expopt, cur);
653 		else
654 			expopt = catopt(expopt, o);
655 	}
656 	free(cur);
657 	free(opts);
658 
659 	/*
660 	 * Remove previous contradictory arguments. Given option "foo" we
661 	 * remove all the "nofoo" options. Given "nofoo" we remove "nonofoo"
662 	 * and "foo" - so we can deal with possible options like "notice".
663 	 */
664 	newopt = NULL;
665 	for (p = expopt; (o = strsep(&p, ",")) != NULL;) {
666 		if ((tmpopt = malloc( strlen(o) + 2 + 1 )) == NULL)
667 			errx(1, "malloc failed");
668 
669 		strcpy(tmpopt, "no");
670 		strcat(tmpopt, o);
671 		remopt(newopt, tmpopt);
672 		free(tmpopt);
673 
674 		if (strncmp("no", o, 2) == 0)
675 			remopt(newopt, o+2);
676 
677 		newopt = catopt(newopt, o);
678 	}
679 	free(expopt);
680 
681 	return newopt;
682 }
683 
684 void
685 remopt(string, opt)
686 	char *string;
687  	const char *opt;
688 {
689 	char *o, *p, *r;
690 
691 	if (string == NULL || *string == '\0' || opt == NULL || *opt == '\0')
692 		return;
693 
694 	r = string;
695 
696 	for (p = string; (o = strsep(&p, ",")) != NULL;) {
697 		if (strcmp(opt, o) != 0) {
698 			if (*r == ',' && *o != '\0')
699 				r++;
700 			while ((*r++ = *o++) != '\0')
701 			    ;
702 			*--r = ',';
703 		}
704 	}
705 	*r = '\0';
706 }
707 
708 void
709 usage()
710 {
711 
712 	(void)fprintf(stderr, "%s\n%s\n%s\n",
713 "usage: mount [-dfpruvw] [-o options] [-t ufs | external_type] special node",
714 "       mount [-adfpruvw] [-t ufs | external_type]",
715 "       mount [-dfpruvw] special | node");
716 	exit(1);
717 }
718 
719 void
720 putfsent(ent)
721 	const struct statfs *ent;
722 {
723 	struct fstab *fst;
724 	char *opts;
725 
726 	opts = flags2opts(ent->f_flags);
727 	printf("%s\t%s\t%s %s", ent->f_mntfromname, ent->f_mntonname,
728 	    ent->f_fstypename, opts);
729 	free(opts);
730 
731 	if ((fst = getfsspec(ent->f_mntfromname)))
732 		printf("\t%u %u\n", fst->fs_freq, fst->fs_passno);
733 	else if ((fst = getfsfile(ent->f_mntonname)))
734 		printf("\t%u %u\n", fst->fs_freq, fst->fs_passno);
735 	else if (strcmp(ent->f_fstypename, "ufs") == 0) {
736 		if (strcmp(ent->f_mntonname, "/") == 0)
737 			printf("\t1 1\n");
738 		else
739 			printf("\t2 2\n");
740 	} else
741 		printf("\t0 0\n");
742 }
743 
744 
745 char *
746 flags2opts(flags)
747 	int flags;
748 {
749 	char *res;
750 
751 	res = NULL;
752 
753 	res = catopt(res, (flags & MNT_RDONLY) ? "ro" : "rw");
754 
755 	if (flags & MNT_SYNCHRONOUS)	res = catopt(res, "sync");
756 	if (flags & MNT_NOEXEC)		res = catopt(res, "noexec");
757 	if (flags & MNT_NOSUID)		res = catopt(res, "nosuid");
758 	if (flags & MNT_NODEV)		res = catopt(res, "nodev");
759 	if (flags & MNT_UNION)		res = catopt(res, "union");
760 	if (flags & MNT_ASYNC)		res = catopt(res, "async");
761 	if (flags & MNT_NOATIME)	res = catopt(res, "noatime");
762 	if (flags & MNT_NOCLUSTERR)	res = catopt(res, "noclusterr");
763 	if (flags & MNT_NOCLUSTERW)	res = catopt(res, "noclusterw");
764 	if (flags & MNT_NOSYMFOLLOW)	res = catopt(res, "nosymfollow");
765 	if (flags & MNT_SUIDDIR)	res = catopt(res, "suiddir");
766 	if (flags & MNT_MULTILABEL)	res = catopt(res, "multilabel");
767 
768 	return res;
769 }
770