xref: /freebsd/sbin/mount/mount.c (revision 1e413cf93298b5b97441a21d9a50fdcd0ee9945e)
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 #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 
71 int debug, fstab_style, verbose;
72 
73 char   *catopt(char *, const char *);
74 struct statfs *getmntpt(const char *);
75 int	hasopt(const char *, const char *);
76 int	ismounted(struct fstab *, struct statfs *, int);
77 int	isremountable(const char *);
78 void	mangle(char *, int *, char *[]);
79 char   *update_options(char *, char *, int);
80 int	mountfs(const char *, const char *, const char *,
81 			int, const char *, const char *);
82 void	remopt(char *, const char *);
83 void	prmount(struct statfs *);
84 void	putfsent(const struct statfs *);
85 void	usage(void);
86 char   *flags2opts(int);
87 
88 /* Map from mount options to printable formats. */
89 static struct opt {
90 	int o_opt;
91 	const char *o_name;
92 } optnames[] = {
93 	{ MNT_ASYNC,		"asynchronous" },
94 	{ MNT_EXPORTED,		"NFS exported" },
95 	{ MNT_LOCAL,		"local" },
96 	{ MNT_NOATIME,		"noatime" },
97 	{ MNT_NOEXEC,		"noexec" },
98 	{ MNT_NOSUID,		"nosuid" },
99 	{ MNT_NOSYMFOLLOW,	"nosymfollow" },
100 	{ MNT_QUOTA,		"with quotas" },
101 	{ MNT_RDONLY,		"read-only" },
102 	{ MNT_SYNCHRONOUS,	"synchronous" },
103 	{ MNT_UNION,		"union" },
104 	{ MNT_NOCLUSTERR,	"noclusterr" },
105 	{ MNT_NOCLUSTERW,	"noclusterw" },
106 	{ MNT_SUIDDIR,		"suiddir" },
107 	{ MNT_SOFTDEP,		"soft-updates" },
108 	{ MNT_MULTILABEL,	"multilabel" },
109 	{ MNT_ACLS,		"acls" },
110 	{ MNT_GJOURNAL,		"gjournal" },
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 static const char userquotaeq[] = "userquota=";
126 static const char groupquotaeq[] = "groupquota=";
127 
128 static int
129 use_mountprog(const char *vfstype)
130 {
131 	/* XXX: We need to get away from implementing external mount
132 	 *      programs for every filesystem, and move towards having
133 	 *	each filesystem properly implement the nmount() system call.
134 	 */
135 	unsigned int i;
136 	const char *fs[] = {
137 	"cd9660", "mfs", "msdosfs", "nfs", "nfs4", "ntfs",
138 	"nwfs", "nullfs", "portalfs", "smbfs", "udf", "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 static void
208 restart_mountd(void)
209 {
210 	struct pidfh *pfh;
211 	pid_t mountdpid;
212 
213 	pfh = pidfile_open(_PATH_MOUNTDPID, 0600, &mountdpid);
214 	if (pfh != NULL) {
215 		/* Mountd is not running. */
216 		pidfile_remove(pfh);
217 		return;
218 	}
219 	if (errno != EEXIST) {
220 		/* Cannot open pidfile for some reason. */
221 		return;
222 	}
223 	/* We have mountd(8) PID in mountdpid varible, let's signal it. */
224 	if (kill(mountdpid, SIGHUP) == -1)
225 		err(1, "signal mountd");
226 }
227 
228 int
229 main(int argc, char *argv[])
230 {
231 	const char *mntfromname, **vfslist, *vfstype;
232 	struct fstab *fs;
233 	struct statfs *mntbuf;
234 	int all, ch, i, init_flags, late, mntsize, rval, have_fstab, ro;
235 	char *cp, *ep, *options;
236 
237 	all = init_flags = late = 0;
238 	ro = 0;
239 	options = NULL;
240 	vfslist = NULL;
241 	vfstype = "ufs";
242 	while ((ch = getopt(argc, argv, "adF:flo:prt:uvw")) != -1)
243 		switch (ch) {
244 		case 'a':
245 			all = 1;
246 			break;
247 		case 'd':
248 			debug = 1;
249 			break;
250 		case 'F':
251 			setfstab(optarg);
252 			break;
253 		case 'f':
254 			init_flags |= MNT_FORCE;
255 			break;
256 		case 'l':
257 			late = 1;
258 			break;
259 		case 'o':
260 			if (*optarg) {
261 				options = catopt(options, optarg);
262 				if (specified_ro(optarg))
263 					ro = 1;
264 			}
265 			break;
266 		case 'p':
267 			fstab_style = 1;
268 			verbose = 1;
269 			break;
270 		case 'r':
271 			options = catopt(options, "ro");
272 			ro = 1;
273 			break;
274 		case 't':
275 			if (vfslist != NULL)
276 				errx(1, "only one -t option may be specified");
277 			vfslist = makevfslist(optarg);
278 			vfstype = optarg;
279 			break;
280 		case 'u':
281 			init_flags |= MNT_UPDATE;
282 			break;
283 		case 'v':
284 			verbose = 1;
285 			break;
286 		case 'w':
287 			options = catopt(options, "noro");
288 			break;
289 		case '?':
290 		default:
291 			usage();
292 			/* NOTREACHED */
293 		}
294 	argc -= optind;
295 	argv += optind;
296 
297 #define	BADTYPE(type)							\
298 	(strcmp(type, FSTAB_RO) &&					\
299 	    strcmp(type, FSTAB_RW) && strcmp(type, FSTAB_RQ))
300 
301 	if ((init_flags & MNT_UPDATE) && (ro == 0))
302 		options = catopt(options, "noro");
303 
304 	rval = 0;
305 	switch (argc) {
306 	case 0:
307 		if ((mntsize = getmntinfo(&mntbuf, MNT_NOWAIT)) == 0)
308 			err(1, "getmntinfo");
309 		if (all) {
310 			while ((fs = getfsent()) != NULL) {
311 				if (BADTYPE(fs->fs_type))
312 					continue;
313 				if (checkvfsname(fs->fs_vfstype, vfslist))
314 					continue;
315 				if (hasopt(fs->fs_mntops, "noauto"))
316 					continue;
317 				if (hasopt(fs->fs_mntops, "late") && !late)
318 					continue;
319 				if (!(init_flags & MNT_UPDATE) &&
320 				    ismounted(fs, mntbuf, mntsize))
321 					continue;
322 				options = update_options(options, fs->fs_mntops,
323 				    mntbuf->f_flags);
324 				if (mountfs(fs->fs_vfstype, fs->fs_spec,
325 				    fs->fs_file, init_flags, options,
326 				    fs->fs_mntops))
327 					rval = 1;
328 			}
329 		} else if (fstab_style) {
330 			for (i = 0; i < mntsize; i++) {
331 				if (checkvfsname(mntbuf[i].f_fstypename, vfslist))
332 					continue;
333 				putfsent(&mntbuf[i]);
334 			}
335 		} else {
336 			for (i = 0; i < mntsize; i++) {
337 				if (checkvfsname(mntbuf[i].f_fstypename,
338 				    vfslist))
339 					continue;
340 				prmount(&mntbuf[i]);
341 			}
342 		}
343 		exit(rval);
344 	case 1:
345 		if (vfslist != NULL)
346 			usage();
347 
348 		rmslashes(*argv, *argv);
349 		if (init_flags & MNT_UPDATE) {
350 			mntfromname = NULL;
351 			have_fstab = 0;
352 			if ((mntbuf = getmntpt(*argv)) == NULL)
353 				errx(1, "not currently mounted %s", *argv);
354 			/*
355 			 * Only get the mntflags from fstab if both mntpoint
356 			 * and mntspec are identical. Also handle the special
357 			 * case where just '/' is mounted and 'spec' is not
358 			 * identical with the one from fstab ('/dev' is missing
359 			 * in the spec-string at boot-time).
360 			 */
361 			if ((fs = getfsfile(mntbuf->f_mntonname)) != NULL) {
362 				if (strcmp(fs->fs_spec,
363 				    mntbuf->f_mntfromname) == 0 &&
364 				    strcmp(fs->fs_file,
365 				    mntbuf->f_mntonname) == 0) {
366 					have_fstab = 1;
367 					mntfromname = mntbuf->f_mntfromname;
368 				} else if (argv[0][0] == '/' &&
369 				    argv[0][1] == '\0') {
370 					fs = getfsfile("/");
371 					have_fstab = 1;
372 					mntfromname = fs->fs_spec;
373 				}
374 			}
375 			if (have_fstab) {
376 				options = update_options(options, fs->fs_mntops,
377 				    mntbuf->f_flags);
378 			} else {
379 				mntfromname = mntbuf->f_mntfromname;
380 				options = update_options(options, NULL,
381 				    mntbuf->f_flags);
382 			}
383 			rval = mountfs(mntbuf->f_fstypename, mntfromname,
384 			    mntbuf->f_mntonname, init_flags, options, 0);
385 			break;
386 		}
387 		if ((fs = getfsfile(*argv)) == NULL &&
388 		    (fs = getfsspec(*argv)) == NULL)
389 			errx(1, "%s: unknown special file or file system",
390 			    *argv);
391 		if (BADTYPE(fs->fs_type))
392 			errx(1, "%s has unknown file system type",
393 			    *argv);
394 		rval = mountfs(fs->fs_vfstype, fs->fs_spec, fs->fs_file,
395 		    init_flags, options, fs->fs_mntops);
396 		break;
397 	case 2:
398 		/*
399 		 * If -t flag has not been specified, the path cannot be
400 		 * found, spec contains either a ':' or a '@', then assume
401 		 * that an NFS file system is being specified ala Sun.
402 		 * Check if the hostname contains only allowed characters
403 		 * to reduce false positives.  IPv6 addresses containing
404 		 * ':' will be correctly parsed only if the separator is '@'.
405 		 * The definition of a valid hostname is taken from RFC 1034.
406 		 */
407 		if (vfslist == NULL && ((ep = strchr(argv[0], '@')) != NULL ||
408 		    (ep = strchr(argv[0], ':')) != NULL)) {
409 			if (*ep == '@') {
410 				cp = ep + 1;
411 				ep = cp + strlen(cp);
412 			} else
413 				cp = argv[0];
414 			while (cp != ep) {
415 				if (!isdigit(*cp) && !isalpha(*cp) &&
416 				    *cp != '.' && *cp != '-' && *cp != ':')
417 					break;
418 				cp++;
419 			}
420 			if (cp == ep)
421 				vfstype = "nfs";
422 		}
423 		rval = mountfs(vfstype,
424 		    argv[0], argv[1], init_flags, options, NULL);
425 		break;
426 	default:
427 		usage();
428 		/* NOTREACHED */
429 	}
430 
431 	/*
432 	 * If the mount was successfully, and done by root, tell mountd the
433 	 * good news.
434 	 */
435 	if (rval == 0 && getuid() == 0)
436 		restart_mountd();
437 
438 	exit(rval);
439 }
440 
441 int
442 ismounted(struct fstab *fs, struct statfs *mntbuf, int mntsize)
443 {
444 	char realfsfile[PATH_MAX];
445 	int i;
446 
447 	if (fs->fs_file[0] == '/' && fs->fs_file[1] == '\0')
448 		/* the root file system can always be remounted */
449 		return (0);
450 
451 	/* The user may have specified a symlink in fstab, resolve the path */
452 	if (realpath(fs->fs_file, realfsfile) == NULL) {
453 		/* Cannot resolve the path, use original one */
454 		strlcpy(realfsfile, fs->fs_file, sizeof(realfsfile));
455 	}
456 
457 	for (i = mntsize - 1; i >= 0; --i)
458 		if (strcmp(realfsfile, mntbuf[i].f_mntonname) == 0 &&
459 		    (!isremountable(fs->fs_vfstype) ||
460 		     strcmp(fs->fs_spec, mntbuf[i].f_mntfromname) == 0))
461 			return (1);
462 	return (0);
463 }
464 
465 int
466 isremountable(const char *vfsname)
467 {
468 	const char **cp;
469 
470 	for (cp = remountable_fs_names; *cp; cp++)
471 		if (strcmp(*cp, vfsname) == 0)
472 			return (1);
473 	return (0);
474 }
475 
476 int
477 hasopt(const char *mntopts, const char *option)
478 {
479 	int negative, found;
480 	char *opt, *optbuf;
481 
482 	if (option[0] == 'n' && option[1] == 'o') {
483 		negative = 1;
484 		option += 2;
485 	} else
486 		negative = 0;
487 	optbuf = strdup(mntopts);
488 	found = 0;
489 	for (opt = optbuf; (opt = strtok(opt, ",")) != NULL; opt = NULL) {
490 		if (opt[0] == 'n' && opt[1] == 'o') {
491 			if (!strcasecmp(opt + 2, option))
492 				found = negative;
493 		} else if (!strcasecmp(opt, option))
494 			found = !negative;
495 	}
496 	free(optbuf);
497 	return (found);
498 }
499 
500 int
501 mountfs(const char *vfstype, const char *spec, const char *name, int flags,
502 	const char *options, const char *mntopts)
503 {
504 	char *argv[100];
505 	struct statfs sf;
506 	int argc, i, ret;
507 	char *optbuf, execname[PATH_MAX], mntpath[PATH_MAX];
508 
509 	/* resolve the mountpoint with realpath(3) */
510 	(void)checkpath(name, mntpath);
511 	name = mntpath;
512 
513 	if (mntopts == NULL)
514 		mntopts = "";
515 	optbuf = catopt(strdup(mntopts), options);
516 
517 	if (strcmp(name, "/") == 0)
518 		flags |= MNT_UPDATE;
519 	if (flags & MNT_FORCE)
520 		optbuf = catopt(optbuf, "force");
521 	if (flags & MNT_RDONLY)
522 		optbuf = catopt(optbuf, "ro");
523 	/*
524 	 * XXX
525 	 * The mount_mfs (newfs) command uses -o to select the
526 	 * optimization mode.  We don't pass the default "-o rw"
527 	 * for that reason.
528 	 */
529 	if (flags & MNT_UPDATE)
530 		optbuf = catopt(optbuf, "update");
531 
532 	/* Compatibility glue. */
533 	if (strcmp(vfstype, "msdos") == 0) {
534 		warnx(
535 		    "Using \"-t msdosfs\", since \"-t msdos\" is deprecated.");
536 		vfstype = "msdosfs";
537 	}
538 
539 	/* Construct the name of the appropriate mount command */
540 	(void)snprintf(execname, sizeof(execname), "mount_%s", vfstype);
541 
542 	argc = 0;
543 	argv[argc++] = execname;
544 	mangle(optbuf, &argc, argv);
545 	argv[argc++] = strdup(spec);
546 	argv[argc++] = strdup(name);
547 	argv[argc] = NULL;
548 
549 	if (debug) {
550 		if (use_mountprog(vfstype))
551 			printf("exec: mount_%s", vfstype);
552 		else
553 			printf("mount -t %s", vfstype);
554 		for (i = 1; i < argc; i++)
555 			(void)printf(" %s", argv[i]);
556 		(void)printf("\n");
557 		return (0);
558 	}
559 
560 	if (use_mountprog(vfstype)) {
561 		ret = exec_mountprog(name, execname, argv);
562 	} else {
563 		ret = mount_fs(vfstype, argc, argv);
564 	}
565 
566 	free(optbuf);
567 
568 	if (verbose) {
569 		if (statfs(name, &sf) < 0) {
570 			warn("statfs %s", name);
571 			return (1);
572 		}
573 		if (fstab_style)
574 			putfsent(&sf);
575 		else
576 			prmount(&sf);
577 	}
578 
579 	return (0);
580 }
581 
582 void
583 prmount(struct statfs *sfp)
584 {
585 	int flags;
586 	unsigned int i;
587 	struct opt *o;
588 	struct passwd *pw;
589 
590 	(void)printf("%s on %s (%s", sfp->f_mntfromname, sfp->f_mntonname,
591 	    sfp->f_fstypename);
592 
593 	flags = sfp->f_flags & MNT_VISFLAGMASK;
594 	for (o = optnames; flags && o->o_opt; o++)
595 		if (flags & o->o_opt) {
596 			(void)printf(", %s", o->o_name);
597 			flags &= ~o->o_opt;
598 		}
599 	/*
600 	 * Inform when file system is mounted by an unprivileged user
601 	 * or privileged non-root user.
602 	 */
603 	if ((flags & MNT_USER) != 0 || sfp->f_owner != 0) {
604 		(void)printf(", mounted by ");
605 		if ((pw = getpwuid(sfp->f_owner)) != NULL)
606 			(void)printf("%s", pw->pw_name);
607 		else
608 			(void)printf("%d", sfp->f_owner);
609 	}
610 	if (verbose) {
611 		if (sfp->f_syncwrites != 0 || sfp->f_asyncwrites != 0)
612 			(void)printf(", writes: sync %ju async %ju",
613 			    (uintmax_t)sfp->f_syncwrites,
614 			    (uintmax_t)sfp->f_asyncwrites);
615 		if (sfp->f_syncreads != 0 || sfp->f_asyncreads != 0)
616 			(void)printf(", reads: sync %ju async %ju",
617 			    (uintmax_t)sfp->f_syncreads,
618 			    (uintmax_t)sfp->f_asyncreads);
619 		if (sfp->f_fsid.val[0] != 0 || sfp->f_fsid.val[1] != 0) {
620 			printf(", fsid ");
621 			for (i = 0; i < sizeof(sfp->f_fsid); i++)
622 				printf("%02x", ((u_char *)&sfp->f_fsid)[i]);
623 		}
624 	}
625 	(void)printf(")\n");
626 }
627 
628 struct statfs *
629 getmntpt(const char *name)
630 {
631 	struct statfs *mntbuf;
632 	int i, mntsize;
633 
634 	mntsize = getmntinfo(&mntbuf, MNT_NOWAIT);
635 	for (i = mntsize - 1; i >= 0; i--) {
636 		if (strcmp(mntbuf[i].f_mntfromname, name) == 0 ||
637 		    strcmp(mntbuf[i].f_mntonname, name) == 0)
638 			return (&mntbuf[i]);
639 	}
640 	return (NULL);
641 }
642 
643 char *
644 catopt(char *s0, const char *s1)
645 {
646 	size_t i;
647 	char *cp;
648 
649 	if (s1 == NULL || *s1 == '\0')
650 		return (s0);
651 
652 	if (s0 && *s0) {
653 		i = strlen(s0) + strlen(s1) + 1 + 1;
654 		if ((cp = malloc(i)) == NULL)
655 			errx(1, "malloc failed");
656 		(void)snprintf(cp, i, "%s,%s", s0, s1);
657 	} else
658 		cp = strdup(s1);
659 
660 	if (s0)
661 		free(s0);
662 	return (cp);
663 }
664 
665 void
666 mangle(char *options, int *argcp, char *argv[])
667 {
668 	char *p, *s;
669 	int argc;
670 
671 	argc = *argcp;
672 	for (s = options; (p = strsep(&s, ",")) != NULL;)
673 		if (*p != '\0') {
674 			if (strcmp(p, "noauto") == 0) {
675 				/*
676 				 * Do not pass noauto option to nmount().
677 				 * or external mount program.  noauto is
678 				 * only used to prevent mounting a filesystem
679 				 * when 'mount -a' is specified, and is
680 				 * not a real mount option.
681 				 */
682 				continue;
683 			} else if (strcmp(p, "late") == 0) {
684 				/*
685 				 * "late" is used to prevent certain file
686 				 * systems from being mounted before late
687 				 * in the boot cycle; for instance,
688 				 * loopback NFS mounts can't be mounted
689 				 * before mountd starts.
690 				 */
691 				continue;
692 			} else if (strcmp(p, "userquota") == 0) {
693 				continue;
694 			} else if (strncmp(p, userquotaeq,
695 			    sizeof(userquotaeq) - 1) == 0) {
696 				continue;
697 			} else if (strcmp(p, "groupquota") == 0) {
698 				continue;
699 			} else if (strncmp(p, groupquotaeq,
700 			    sizeof(groupquotaeq) - 1) == 0) {
701 				continue;
702 			} else if (*p == '-') {
703 				argv[argc++] = p;
704 				p = strchr(p, '=');
705 				if (p != NULL) {
706 					*p = '\0';
707 					argv[argc++] = p+1;
708 				}
709 			} else {
710 				argv[argc++] = strdup("-o");
711 				argv[argc++] = p;
712 			}
713 		}
714 
715 	*argcp = argc;
716 }
717 
718 
719 char *
720 update_options(char *opts, char *fstab, int curflags)
721 {
722 	char *o, *p;
723 	char *cur;
724 	char *expopt, *newopt, *tmpopt;
725 
726 	if (opts == NULL)
727 		return (strdup(""));
728 
729 	/* remove meta options from list */
730 	remopt(fstab, MOUNT_META_OPTION_FSTAB);
731 	remopt(fstab, MOUNT_META_OPTION_CURRENT);
732 	cur = flags2opts(curflags);
733 
734 	/*
735 	 * Expand all meta-options passed to us first.
736 	 */
737 	expopt = NULL;
738 	for (p = opts; (o = strsep(&p, ",")) != NULL;) {
739 		if (strcmp(MOUNT_META_OPTION_FSTAB, o) == 0)
740 			expopt = catopt(expopt, fstab);
741 		else if (strcmp(MOUNT_META_OPTION_CURRENT, o) == 0)
742 			expopt = catopt(expopt, cur);
743 		else
744 			expopt = catopt(expopt, o);
745 	}
746 	free(cur);
747 	free(opts);
748 
749 	/*
750 	 * Remove previous contradictory arguments. Given option "foo" we
751 	 * remove all the "nofoo" options. Given "nofoo" we remove "nonofoo"
752 	 * and "foo" - so we can deal with possible options like "notice".
753 	 */
754 	newopt = NULL;
755 	for (p = expopt; (o = strsep(&p, ",")) != NULL;) {
756 		if ((tmpopt = malloc( strlen(o) + 2 + 1 )) == NULL)
757 			errx(1, "malloc failed");
758 
759 		strcpy(tmpopt, "no");
760 		strcat(tmpopt, o);
761 		remopt(newopt, tmpopt);
762 		free(tmpopt);
763 
764 		if (strncmp("no", o, 2) == 0)
765 			remopt(newopt, o+2);
766 
767 		newopt = catopt(newopt, o);
768 	}
769 	free(expopt);
770 
771 	return (newopt);
772 }
773 
774 void
775 remopt(char *string, const char *opt)
776 {
777 	char *o, *p, *r;
778 
779 	if (string == NULL || *string == '\0' || opt == NULL || *opt == '\0')
780 		return;
781 
782 	r = string;
783 
784 	for (p = string; (o = strsep(&p, ",")) != NULL;) {
785 		if (strcmp(opt, o) != 0) {
786 			if (*r == ',' && *o != '\0')
787 				r++;
788 			while ((*r++ = *o++) != '\0')
789 			    ;
790 			*--r = ',';
791 		}
792 	}
793 	*r = '\0';
794 }
795 
796 void
797 usage(void)
798 {
799 
800 	(void)fprintf(stderr, "%s\n%s\n%s\n",
801 "usage: mount [-adflpruvw] [-F fstab] [-o options] [-t ufs | external_type]",
802 "       mount [-dfpruvw] special | node",
803 "       mount [-dfpruvw] [-o options] [-t ufs | external_type] special node");
804 	exit(1);
805 }
806 
807 void
808 putfsent(const struct statfs *ent)
809 {
810 	struct fstab *fst;
811 	char *opts;
812 	int l;
813 
814 	opts = flags2opts(ent->f_flags);
815 
816 	/*
817 	 * "rw" is not a real mount option; this is why we print NULL as "rw"
818 	 * if opts is still NULL here.
819 	 */
820 	l = strlen(ent->f_mntfromname);
821 	printf("%s%s%s%s", ent->f_mntfromname,
822 	    l < 8 ? "\t" : "",
823 	    l < 16 ? "\t" : "",
824 	    l < 24 ? "\t" : " ");
825 	l = strlen(ent->f_mntonname);
826 	printf("%s%s%s%s", ent->f_mntonname,
827 	    l < 8 ? "\t" : "",
828 	    l < 16 ? "\t" : "",
829 	    l < 24 ? "\t" : " ");
830 	printf("%s\t", ent->f_fstypename);
831 	if (opts == NULL) {
832 		printf("%s\t", "rw");
833 	} else {
834 		l = strlen(opts);
835 		printf("%s%s", opts,
836 		    l < 8 ? "\t" : " ");
837 	}
838 	free(opts);
839 
840 	if ((fst = getfsspec(ent->f_mntfromname)))
841 		printf("\t%u %u\n", fst->fs_freq, fst->fs_passno);
842 	else if ((fst = getfsfile(ent->f_mntonname)))
843 		printf("\t%u %u\n", fst->fs_freq, fst->fs_passno);
844 	else if (strcmp(ent->f_fstypename, "ufs") == 0) {
845 		if (strcmp(ent->f_mntonname, "/") == 0)
846 			printf("\t1 1\n");
847 		else
848 			printf("\t2 2\n");
849 	} else
850 		printf("\t0 0\n");
851 }
852 
853 
854 char *
855 flags2opts(int flags)
856 {
857 	char *res;
858 
859 	res = NULL;
860 
861 	if (flags & MNT_RDONLY)		res = catopt(res, "ro");
862 	if (flags & MNT_SYNCHRONOUS)	res = catopt(res, "sync");
863 	if (flags & MNT_NOEXEC)		res = catopt(res, "noexec");
864 	if (flags & MNT_NOSUID)		res = catopt(res, "nosuid");
865 	if (flags & MNT_UNION)		res = catopt(res, "union");
866 	if (flags & MNT_ASYNC)		res = catopt(res, "async");
867 	if (flags & MNT_NOATIME)	res = catopt(res, "noatime");
868 	if (flags & MNT_NOCLUSTERR)	res = catopt(res, "noclusterr");
869 	if (flags & MNT_NOCLUSTERW)	res = catopt(res, "noclusterw");
870 	if (flags & MNT_NOSYMFOLLOW)	res = catopt(res, "nosymfollow");
871 	if (flags & MNT_SUIDDIR)	res = catopt(res, "suiddir");
872 	if (flags & MNT_MULTILABEL)	res = catopt(res, "multilabel");
873 	if (flags & MNT_ACLS)		res = catopt(res, "acls");
874 	if (flags & MNT_GJOURNAL)	res = catopt(res, "gjournal");
875 
876 	return (res);
877 }
878