xref: /freebsd/sbin/mount/mount.c (revision 0efd6615cd5f39b67cec82a7034e655f3b5801e3)
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
31 static 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
38 static char sccsid[] = "@(#)mount.c	8.25 (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/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 
62 #include "extern.h"
63 #include "mntopts.h"
64 #include "pathnames.h"
65 
66 /* `meta' options */
67 #define MOUNT_META_OPTION_FSTAB		"fstab"
68 #define MOUNT_META_OPTION_CURRENT	"current"
69 
70 int debug, fstab_style, verbose;
71 
72 char   *catopt(char *, const char *);
73 struct statfs *getmntpt(const char *);
74 int	hasopt(const char *, const char *);
75 int	ismounted(struct fstab *, struct statfs *, int);
76 int	isremountable(const char *);
77 void	mangle(char *, int *, char *[]);
78 char   *update_options(char *, char *, int);
79 int	mountfs(const char *, const char *, const char *,
80 			int, const char *, const char *);
81 void	remopt(char *, const char *);
82 void	prmount(struct statfs *);
83 void	putfsent(const struct statfs *);
84 void	usage(void);
85 char   *flags2opts(int);
86 
87 /* Map from mount options to printable formats. */
88 static struct opt {
89 	int o_opt;
90 	const char *o_name;
91 } optnames[] = {
92 	{ MNT_ASYNC,		"asynchronous" },
93 	{ MNT_EXPORTED,		"NFS exported" },
94 	{ MNT_LOCAL,		"local" },
95 	{ MNT_NOATIME,		"noatime" },
96 	{ MNT_NOEXEC,		"noexec" },
97 	{ MNT_NOSUID,		"nosuid" },
98 	{ MNT_NOSYMFOLLOW,	"nosymfollow" },
99 	{ MNT_QUOTA,		"with quotas" },
100 	{ MNT_RDONLY,		"read-only" },
101 	{ MNT_SYNCHRONOUS,	"synchronous" },
102 	{ MNT_UNION,		"union" },
103 	{ MNT_NOCLUSTERR,	"noclusterr" },
104 	{ MNT_NOCLUSTERW,	"noclusterw" },
105 	{ MNT_SUIDDIR,		"suiddir" },
106 	{ MNT_SOFTDEP,		"soft-updates" },
107 	{ MNT_MULTILABEL,	"multilabel" },
108 	{ MNT_ACLS,		"acls" },
109 	{ MNT_GJOURNAL,		"gjournal" },
110 	{ 0, NULL }
111 };
112 
113 /*
114  * List of VFS types that can be remounted without becoming mounted on top
115  * of each other.
116  * XXX Is this list correct?
117  */
118 static const char *
119 remountable_fs_names[] = {
120 	"ufs", "ffs", "ext2fs",
121 	0
122 };
123 
124 static const char userquotaeq[] = "userquota=";
125 static const char groupquotaeq[] = "groupquota=";
126 
127 static int
128 use_mountprog(const char *vfstype)
129 {
130 	/* XXX: We need to get away from implementing external mount
131 	 *      programs for every filesystem, and move towards having
132 	 *	each filesystem properly implement the nmount() system call.
133 	 */
134 	unsigned int i;
135 	const char *fs[] = {
136 	"cd9660", "mfs", "msdosfs", "nfs", "nfs4", "ntfs",
137 	"nwfs", "nullfs", "portalfs", "smbfs", "udf", "umapfs",
138 	"unionfs",
139 	NULL
140 	};
141 
142 	for (i = 0; fs[i] != NULL; ++i) {
143 		if (strcmp(vfstype, fs[i]) == 0)
144 			return (1);
145 	}
146 
147 	return (0);
148 }
149 
150 static int
151 exec_mountprog(const char *name, const char *execname, char *const argv[])
152 {
153 	pid_t pid;
154 	int status;
155 
156 	switch (pid = fork()) {
157 	case -1:				/* Error. */
158 		warn("fork");
159 		exit (1);
160 	case 0:					/* Child. */
161 		/* Go find an executable. */
162 		execvP(execname, _PATH_SYSPATH, argv);
163 		if (errno == ENOENT) {
164 			warn("exec %s not found in %s", execname,
165 			    _PATH_SYSPATH);
166 		}
167 		exit(1);
168 	default:				/* Parent. */
169 		if (waitpid(pid, &status, 0) < 0) {
170 			warn("waitpid");
171 			return (1);
172 		}
173 
174 		if (WIFEXITED(status)) {
175 			if (WEXITSTATUS(status) != 0)
176 				return (WEXITSTATUS(status));
177 		} else if (WIFSIGNALED(status)) {
178 			warnx("%s: %s", name, sys_siglist[WTERMSIG(status)]);
179 			return (1);
180 		}
181 		break;
182 	}
183 
184 	return (0);
185 }
186 
187 static int
188 specified_ro(const char *arg)
189 {
190 	char *optbuf, *opt;
191 	int ret = 0;
192 
193 	optbuf = strdup(arg);
194 	if (optbuf == NULL)
195 		 err(1, NULL);
196 
197 	for (opt = optbuf; (opt = strtok(opt, ",")) != NULL; opt = NULL) {
198 		if (strcmp(opt, "ro") == 0) {
199 			ret = 1;
200 			break;
201 		}
202 	}
203 	free(optbuf);
204 	return (ret);
205 }
206 
207 int
208 main(int argc, char *argv[])
209 {
210 	const char *mntfromname, **vfslist, *vfstype;
211 	struct fstab *fs;
212 	struct statfs *mntbuf;
213 	FILE *mountdfp;
214 	pid_t pid;
215 	int all, ch, i, init_flags, late, mntsize, rval, have_fstab, ro;
216 	char *cp, *ep, *options;
217 
218 	all = init_flags = late = 0;
219 	ro = 0;
220 	options = NULL;
221 	vfslist = NULL;
222 	vfstype = "ufs";
223 	while ((ch = getopt(argc, argv, "adF:flo:prt:uvw")) != -1)
224 		switch (ch) {
225 		case 'a':
226 			all = 1;
227 			break;
228 		case 'd':
229 			debug = 1;
230 			break;
231 		case 'F':
232 			setfstab(optarg);
233 			break;
234 		case 'f':
235 			init_flags |= MNT_FORCE;
236 			break;
237 		case 'l':
238 			late = 1;
239 			break;
240 		case 'o':
241 			if (*optarg) {
242 				options = catopt(options, optarg);
243 				if (specified_ro(optarg))
244 					ro = 1;
245 			}
246 			break;
247 		case 'p':
248 			fstab_style = 1;
249 			verbose = 1;
250 			break;
251 		case 'r':
252 			options = catopt(options, "ro");
253 			ro = 1;
254 			break;
255 		case 't':
256 			if (vfslist != NULL)
257 				errx(1, "only one -t option may be specified");
258 			vfslist = makevfslist(optarg);
259 			vfstype = optarg;
260 			break;
261 		case 'u':
262 			init_flags |= MNT_UPDATE;
263 			break;
264 		case 'v':
265 			verbose = 1;
266 			break;
267 		case 'w':
268 			options = catopt(options, "noro");
269 			break;
270 		case '?':
271 		default:
272 			usage();
273 			/* NOTREACHED */
274 		}
275 	argc -= optind;
276 	argv += optind;
277 
278 #define	BADTYPE(type)							\
279 	(strcmp(type, FSTAB_RO) &&					\
280 	    strcmp(type, FSTAB_RW) && strcmp(type, FSTAB_RQ))
281 
282 	if ((init_flags & MNT_UPDATE) && (ro == 0))
283 		options = catopt(options, "noro");
284 
285 	rval = 0;
286 	switch (argc) {
287 	case 0:
288 		if ((mntsize = getmntinfo(&mntbuf, MNT_NOWAIT)) == 0)
289 			err(1, "getmntinfo");
290 		if (all) {
291 			while ((fs = getfsent()) != NULL) {
292 				if (BADTYPE(fs->fs_type))
293 					continue;
294 				if (checkvfsname(fs->fs_vfstype, vfslist))
295 					continue;
296 				if (hasopt(fs->fs_mntops, "noauto"))
297 					continue;
298 				if (hasopt(fs->fs_mntops, "late") && !late)
299 					continue;
300 				if (!(init_flags & MNT_UPDATE) &&
301 				    ismounted(fs, mntbuf, mntsize))
302 					continue;
303 				options = update_options(options, fs->fs_mntops,
304 				    mntbuf->f_flags);
305 				if (mountfs(fs->fs_vfstype, fs->fs_spec,
306 				    fs->fs_file, init_flags, options,
307 				    fs->fs_mntops))
308 					rval = 1;
309 			}
310 		} else if (fstab_style) {
311 			for (i = 0; i < mntsize; i++) {
312 				if (checkvfsname(mntbuf[i].f_fstypename, vfslist))
313 					continue;
314 				putfsent(&mntbuf[i]);
315 			}
316 		} else {
317 			for (i = 0; i < mntsize; i++) {
318 				if (checkvfsname(mntbuf[i].f_fstypename,
319 				    vfslist))
320 					continue;
321 				prmount(&mntbuf[i]);
322 			}
323 		}
324 		exit(rval);
325 	case 1:
326 		if (vfslist != NULL)
327 			usage();
328 
329 		rmslashes(*argv, *argv);
330 		if (init_flags & MNT_UPDATE) {
331 			mntfromname = NULL;
332 			have_fstab = 0;
333 			if ((mntbuf = getmntpt(*argv)) == NULL)
334 				errx(1, "not currently mounted %s", *argv);
335 			/*
336 			 * Only get the mntflags from fstab if both mntpoint
337 			 * and mntspec are identical. Also handle the special
338 			 * case where just '/' is mounted and 'spec' is not
339 			 * identical with the one from fstab ('/dev' is missing
340 			 * in the spec-string at boot-time).
341 			 */
342 			if ((fs = getfsfile(mntbuf->f_mntonname)) != NULL) {
343 				if (strcmp(fs->fs_spec,
344 				    mntbuf->f_mntfromname) == 0 &&
345 				    strcmp(fs->fs_file,
346 				    mntbuf->f_mntonname) == 0) {
347 					have_fstab = 1;
348 					mntfromname = mntbuf->f_mntfromname;
349 				} else if (argv[0][0] == '/' &&
350 				    argv[0][1] == '\0') {
351 					fs = getfsfile("/");
352 					have_fstab = 1;
353 					mntfromname = fs->fs_spec;
354 				}
355 			}
356 			if (have_fstab) {
357 				options = update_options(options, fs->fs_mntops,
358 				    mntbuf->f_flags);
359 			} else {
360 				mntfromname = mntbuf->f_mntfromname;
361 				options = update_options(options, NULL,
362 				    mntbuf->f_flags);
363 			}
364 			rval = mountfs(mntbuf->f_fstypename, mntfromname,
365 			    mntbuf->f_mntonname, init_flags, options, 0);
366 			break;
367 		}
368 		if ((fs = getfsfile(*argv)) == NULL &&
369 		    (fs = getfsspec(*argv)) == NULL)
370 			errx(1, "%s: unknown special file or file system",
371 			    *argv);
372 		if (BADTYPE(fs->fs_type))
373 			errx(1, "%s has unknown file system type",
374 			    *argv);
375 		rval = mountfs(fs->fs_vfstype, fs->fs_spec, fs->fs_file,
376 		    init_flags, options, fs->fs_mntops);
377 		break;
378 	case 2:
379 		/*
380 		 * If -t flag has not been specified, the path cannot be
381 		 * found, spec contains either a ':' or a '@', then assume
382 		 * that an NFS file system is being specified ala Sun.
383 		 * Check if the hostname contains only allowed characters
384 		 * to reduce false positives.  IPv6 addresses containing
385 		 * ':' will be correctly parsed only if the separator is '@'.
386 		 * The definition of a valid hostname is taken from RFC 1034.
387 		 */
388 		if (vfslist == NULL && ((ep = strchr(argv[0], '@')) != NULL ||
389 		    (ep = strchr(argv[0], ':')) != NULL)) {
390 			if (*ep == '@') {
391 				cp = ep + 1;
392 				ep = cp + strlen(cp);
393 			} else
394 				cp = argv[0];
395 			while (cp != ep) {
396 				if (!isdigit(*cp) && !isalpha(*cp) &&
397 				    *cp != '.' && *cp != '-' && *cp != ':')
398 					break;
399 				cp++;
400 			}
401 			if (cp == ep)
402 				vfstype = "nfs";
403 		}
404 		rval = mountfs(vfstype,
405 		    argv[0], argv[1], init_flags, options, NULL);
406 		break;
407 	default:
408 		usage();
409 		/* NOTREACHED */
410 	}
411 
412 	/*
413 	 * If the mount was successfully, and done by root, tell mountd the
414 	 * good news.  Pid checks are probably unnecessary, but don't hurt.
415 	 */
416 	if (rval == 0 && getuid() == 0 &&
417 	    (mountdfp = fopen(_PATH_MOUNTDPID, "r")) != NULL) {
418 		if (fscanf(mountdfp, "%d", &pid) == 1 &&
419 		     pid > 0 && kill(pid, SIGHUP) == -1 && errno != ESRCH)
420 			err(1, "signal mountd");
421 		(void)fclose(mountdfp);
422 	}
423 
424 	exit(rval);
425 }
426 
427 int
428 ismounted(struct fstab *fs, struct statfs *mntbuf, int mntsize)
429 {
430 	char realfsfile[PATH_MAX];
431 	int i;
432 
433 	if (fs->fs_file[0] == '/' && fs->fs_file[1] == '\0')
434 		/* the root file system can always be remounted */
435 		return (0);
436 
437 	/* The user may have specified a symlink in fstab, resolve the path */
438 	if (realpath(fs->fs_file, realfsfile) == NULL) {
439 		/* Cannot resolve the path, use original one */
440 		strlcpy(realfsfile, fs->fs_file, sizeof(realfsfile));
441 	}
442 
443 	for (i = mntsize - 1; i >= 0; --i)
444 		if (strcmp(realfsfile, mntbuf[i].f_mntonname) == 0 &&
445 		    (!isremountable(fs->fs_vfstype) ||
446 		     strcmp(fs->fs_spec, mntbuf[i].f_mntfromname) == 0))
447 			return (1);
448 	return (0);
449 }
450 
451 int
452 isremountable(const char *vfsname)
453 {
454 	const char **cp;
455 
456 	for (cp = remountable_fs_names; *cp; cp++)
457 		if (strcmp(*cp, vfsname) == 0)
458 			return (1);
459 	return (0);
460 }
461 
462 int
463 hasopt(const char *mntopts, const char *option)
464 {
465 	int negative, found;
466 	char *opt, *optbuf;
467 
468 	if (option[0] == 'n' && option[1] == 'o') {
469 		negative = 1;
470 		option += 2;
471 	} else
472 		negative = 0;
473 	optbuf = strdup(mntopts);
474 	found = 0;
475 	for (opt = optbuf; (opt = strtok(opt, ",")) != NULL; opt = NULL) {
476 		if (opt[0] == 'n' && opt[1] == 'o') {
477 			if (!strcasecmp(opt + 2, option))
478 				found = negative;
479 		} else if (!strcasecmp(opt, option))
480 			found = !negative;
481 	}
482 	free(optbuf);
483 	return (found);
484 }
485 
486 int
487 mountfs(const char *vfstype, const char *spec, const char *name, int flags,
488 	const char *options, const char *mntopts)
489 {
490 	char *argv[100];
491 	struct statfs sf;
492 	int argc, i, ret;
493 	char *optbuf, execname[PATH_MAX], mntpath[PATH_MAX];
494 
495 	/* resolve the mountpoint with realpath(3) */
496 	(void)checkpath(name, mntpath);
497 	name = mntpath;
498 
499 	if (mntopts == NULL)
500 		mntopts = "";
501 	optbuf = catopt(strdup(mntopts), options);
502 
503 	if (strcmp(name, "/") == 0)
504 		flags |= MNT_UPDATE;
505 	if (flags & MNT_FORCE)
506 		optbuf = catopt(optbuf, "force");
507 	if (flags & MNT_RDONLY)
508 		optbuf = catopt(optbuf, "ro");
509 	/*
510 	 * XXX
511 	 * The mount_mfs (newfs) command uses -o to select the
512 	 * optimization mode.  We don't pass the default "-o rw"
513 	 * for that reason.
514 	 */
515 	if (flags & MNT_UPDATE)
516 		optbuf = catopt(optbuf, "update");
517 
518 	/* Compatibility glue. */
519 	if (strcmp(vfstype, "msdos") == 0)
520 		vfstype = "msdosfs";
521 
522 	/* Construct the name of the appropriate mount command */
523 	(void)snprintf(execname, sizeof(execname), "mount_%s", vfstype);
524 
525 	argc = 0;
526 	argv[argc++] = execname;
527 	mangle(optbuf, &argc, argv);
528 	argv[argc++] = strdup(spec);
529 	argv[argc++] = strdup(name);
530 	argv[argc] = NULL;
531 
532 	if (debug) {
533 		if (use_mountprog(vfstype))
534 			printf("exec: mount_%s", vfstype);
535 		else
536 			printf("mount -t %s", vfstype);
537 		for (i = 1; i < argc; i++)
538 			(void)printf(" %s", argv[i]);
539 		(void)printf("\n");
540 		return (0);
541 	}
542 
543 	if (use_mountprog(vfstype)) {
544 		ret = exec_mountprog(name, execname, argv);
545 	} else {
546 		ret = mount_fs(vfstype, argc, argv);
547 	}
548 
549 	free(optbuf);
550 
551 	if (verbose) {
552 		if (statfs(name, &sf) < 0) {
553 			warn("statfs %s", name);
554 			return (1);
555 		}
556 		if (fstab_style)
557 			putfsent(&sf);
558 		else
559 			prmount(&sf);
560 	}
561 
562 	return (0);
563 }
564 
565 void
566 prmount(struct statfs *sfp)
567 {
568 	int flags;
569 	unsigned int i;
570 	struct opt *o;
571 	struct passwd *pw;
572 
573 	(void)printf("%s on %s (%s", sfp->f_mntfromname, sfp->f_mntonname,
574 	    sfp->f_fstypename);
575 
576 	flags = sfp->f_flags & MNT_VISFLAGMASK;
577 	for (o = optnames; flags && o->o_opt; o++)
578 		if (flags & o->o_opt) {
579 			(void)printf(", %s", o->o_name);
580 			flags &= ~o->o_opt;
581 		}
582 	/*
583 	 * Inform when file system is mounted by an unprivileged user
584 	 * or privileged non-root user.
585 	 */
586 	if ((flags & MNT_USER) != 0 || sfp->f_owner != 0) {
587 		(void)printf(", mounted by ");
588 		if ((pw = getpwuid(sfp->f_owner)) != NULL)
589 			(void)printf("%s", pw->pw_name);
590 		else
591 			(void)printf("%d", sfp->f_owner);
592 	}
593 	if (verbose) {
594 		if (sfp->f_syncwrites != 0 || sfp->f_asyncwrites != 0)
595 			(void)printf(", writes: sync %ju async %ju",
596 			    (uintmax_t)sfp->f_syncwrites,
597 			    (uintmax_t)sfp->f_asyncwrites);
598 		if (sfp->f_syncreads != 0 || sfp->f_asyncreads != 0)
599 			(void)printf(", reads: sync %ju async %ju",
600 			    (uintmax_t)sfp->f_syncreads,
601 			    (uintmax_t)sfp->f_asyncreads);
602 		if (sfp->f_fsid.val[0] != 0 || sfp->f_fsid.val[1] != 0) {
603 			printf(", fsid ");
604 			for (i = 0; i < sizeof(sfp->f_fsid); i++)
605 				printf("%02x", ((u_char *)&sfp->f_fsid)[i]);
606 		}
607 	}
608 	(void)printf(")\n");
609 }
610 
611 struct statfs *
612 getmntpt(const char *name)
613 {
614 	struct statfs *mntbuf;
615 	int i, mntsize;
616 
617 	mntsize = getmntinfo(&mntbuf, MNT_NOWAIT);
618 	for (i = mntsize - 1; i >= 0; i--) {
619 		if (strcmp(mntbuf[i].f_mntfromname, name) == 0 ||
620 		    strcmp(mntbuf[i].f_mntonname, name) == 0)
621 			return (&mntbuf[i]);
622 	}
623 	return (NULL);
624 }
625 
626 char *
627 catopt(char *s0, const char *s1)
628 {
629 	size_t i;
630 	char *cp;
631 
632 	if (s1 == NULL || *s1 == '\0')
633 		return (s0);
634 
635 	if (s0 && *s0) {
636 		i = strlen(s0) + strlen(s1) + 1 + 1;
637 		if ((cp = malloc(i)) == NULL)
638 			errx(1, "malloc failed");
639 		(void)snprintf(cp, i, "%s,%s", s0, s1);
640 	} else
641 		cp = strdup(s1);
642 
643 	if (s0)
644 		free(s0);
645 	return (cp);
646 }
647 
648 void
649 mangle(char *options, int *argcp, char *argv[])
650 {
651 	char *p, *s;
652 	int argc;
653 
654 	argc = *argcp;
655 	for (s = options; (p = strsep(&s, ",")) != NULL;)
656 		if (*p != '\0') {
657 			if (strcmp(p, "noauto") == 0) {
658 				/*
659 				 * Do not pass noauto option to nmount().
660 				 * or external mount program.  noauto is
661 				 * only used to prevent mounting a filesystem
662 				 * when 'mount -a' is specified, and is
663 				 * not a real mount option.
664 				 */
665 				continue;
666 			} else if (strcmp(p, "late") == 0) {
667 				/*
668 				 * "late" is used to prevent certain file
669 				 * systems from being mounted before late
670 				 * in the boot cycle; for instance,
671 				 * loopback NFS mounts can't be mounted
672 				 * before mountd starts.
673 				 */
674 				continue;
675 			} else if (strcmp(p, "userquota") == 0) {
676 				continue;
677 			} else if (strncmp(p, userquotaeq,
678 			    sizeof(userquotaeq) - 1) == 0) {
679 				continue;
680 			} else if (strcmp(p, "groupquota") == 0) {
681 				continue;
682 			} else if (strncmp(p, groupquotaeq,
683 			    sizeof(groupquotaeq) - 1) == 0) {
684 				continue;
685 			} else if (*p == '-') {
686 				argv[argc++] = p;
687 				p = strchr(p, '=');
688 				if (p != NULL) {
689 					*p = '\0';
690 					argv[argc++] = p+1;
691 				}
692 			} else {
693 				argv[argc++] = strdup("-o");
694 				argv[argc++] = p;
695 			}
696 		}
697 
698 	*argcp = argc;
699 }
700 
701 
702 char *
703 update_options(char *opts, char *fstab, int curflags)
704 {
705 	char *o, *p;
706 	char *cur;
707 	char *expopt, *newopt, *tmpopt;
708 
709 	if (opts == NULL)
710 		return (strdup(""));
711 
712 	/* remove meta options from list */
713 	remopt(fstab, MOUNT_META_OPTION_FSTAB);
714 	remopt(fstab, MOUNT_META_OPTION_CURRENT);
715 	cur = flags2opts(curflags);
716 
717 	/*
718 	 * Expand all meta-options passed to us first.
719 	 */
720 	expopt = NULL;
721 	for (p = opts; (o = strsep(&p, ",")) != NULL;) {
722 		if (strcmp(MOUNT_META_OPTION_FSTAB, o) == 0)
723 			expopt = catopt(expopt, fstab);
724 		else if (strcmp(MOUNT_META_OPTION_CURRENT, o) == 0)
725 			expopt = catopt(expopt, cur);
726 		else
727 			expopt = catopt(expopt, o);
728 	}
729 	free(cur);
730 	free(opts);
731 
732 	/*
733 	 * Remove previous contradictory arguments. Given option "foo" we
734 	 * remove all the "nofoo" options. Given "nofoo" we remove "nonofoo"
735 	 * and "foo" - so we can deal with possible options like "notice".
736 	 */
737 	newopt = NULL;
738 	for (p = expopt; (o = strsep(&p, ",")) != NULL;) {
739 		if ((tmpopt = malloc( strlen(o) + 2 + 1 )) == NULL)
740 			errx(1, "malloc failed");
741 
742 		strcpy(tmpopt, "no");
743 		strcat(tmpopt, o);
744 		remopt(newopt, tmpopt);
745 		free(tmpopt);
746 
747 		if (strncmp("no", o, 2) == 0)
748 			remopt(newopt, o+2);
749 
750 		newopt = catopt(newopt, o);
751 	}
752 	free(expopt);
753 
754 	return (newopt);
755 }
756 
757 void
758 remopt(char *string, const char *opt)
759 {
760 	char *o, *p, *r;
761 
762 	if (string == NULL || *string == '\0' || opt == NULL || *opt == '\0')
763 		return;
764 
765 	r = string;
766 
767 	for (p = string; (o = strsep(&p, ",")) != NULL;) {
768 		if (strcmp(opt, o) != 0) {
769 			if (*r == ',' && *o != '\0')
770 				r++;
771 			while ((*r++ = *o++) != '\0')
772 			    ;
773 			*--r = ',';
774 		}
775 	}
776 	*r = '\0';
777 }
778 
779 void
780 usage(void)
781 {
782 
783 	(void)fprintf(stderr, "%s\n%s\n%s\n",
784 "usage: mount [-adflpruvw] [-F fstab] [-o options] [-t ufs | external_type]",
785 "       mount [-dfpruvw] special | node",
786 "       mount [-dfpruvw] [-o options] [-t ufs | external_type] special node");
787 	exit(1);
788 }
789 
790 void
791 putfsent(const struct statfs *ent)
792 {
793 	struct fstab *fst;
794 	char *opts;
795 
796 	opts = flags2opts(ent->f_flags);
797 
798 	/*
799 	 * "rw" is not a real mount option; this is why we print NULL as "rw"
800 	 * if opts is still NULL here.
801 	 */
802 	printf("%s\t%s\t%s %s", ent->f_mntfromname, ent->f_mntonname,
803 	    ent->f_fstypename, opts ? opts : "rw");
804 	free(opts);
805 
806 	if ((fst = getfsspec(ent->f_mntfromname)))
807 		printf("\t%u %u\n", fst->fs_freq, fst->fs_passno);
808 	else if ((fst = getfsfile(ent->f_mntonname)))
809 		printf("\t%u %u\n", fst->fs_freq, fst->fs_passno);
810 	else if (strcmp(ent->f_fstypename, "ufs") == 0) {
811 		if (strcmp(ent->f_mntonname, "/") == 0)
812 			printf("\t1 1\n");
813 		else
814 			printf("\t2 2\n");
815 	} else
816 		printf("\t0 0\n");
817 }
818 
819 
820 char *
821 flags2opts(int flags)
822 {
823 	char *res;
824 
825 	res = NULL;
826 
827 	if (flags & MNT_RDONLY)		res = catopt(res, "ro");
828 	if (flags & MNT_SYNCHRONOUS)	res = catopt(res, "sync");
829 	if (flags & MNT_NOEXEC)		res = catopt(res, "noexec");
830 	if (flags & MNT_NOSUID)		res = catopt(res, "nosuid");
831 	if (flags & MNT_UNION)		res = catopt(res, "union");
832 	if (flags & MNT_ASYNC)		res = catopt(res, "async");
833 	if (flags & MNT_NOATIME)	res = catopt(res, "noatime");
834 	if (flags & MNT_NOCLUSTERR)	res = catopt(res, "noclusterr");
835 	if (flags & MNT_NOCLUSTERW)	res = catopt(res, "noclusterw");
836 	if (flags & MNT_NOSYMFOLLOW)	res = catopt(res, "nosymfollow");
837 	if (flags & MNT_SUIDDIR)	res = catopt(res, "suiddir");
838 	if (flags & MNT_MULTILABEL)	res = catopt(res, "multilabel");
839 	if (flags & MNT_ACLS)		res = catopt(res, "acls");
840 	if (flags & MNT_GJOURNAL)	res = catopt(res, "gjournal");
841 
842 	return (res);
843 }
844