xref: /freebsd/sbin/mount/mount.c (revision 193d9e768ba63fcfb187cfd17f461f7d41345048)
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. 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 #if 0
35 static char sccsid[] = "@(#)mount.c	8.25 (Berkeley) 5/8/95";
36 #endif
37 #endif /* not lint */
38 
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41 
42 #include <sys/param.h>
43 #include <sys/mount.h>
44 #include <sys/stat.h>
45 #include <sys/wait.h>
46 
47 #include <ctype.h>
48 #include <err.h>
49 #include <errno.h>
50 #include <fstab.h>
51 #include <paths.h>
52 #include <pwd.h>
53 #include <signal.h>
54 #include <stdint.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <string.h>
58 #include <unistd.h>
59 #include <libutil.h>
60 
61 #include "extern.h"
62 #include "mntopts.h"
63 #include "pathnames.h"
64 
65 /* `meta' options */
66 #define MOUNT_META_OPTION_FSTAB		"fstab"
67 #define MOUNT_META_OPTION_CURRENT	"current"
68 
69 static int debug, fstab_style, verbose;
70 
71 struct cpa {
72 	char	**a;
73 	ssize_t	sz;
74 	int	c;
75 };
76 
77 char   *catopt(char *, const char *);
78 struct statfs *getmntpt(const char *);
79 int	hasopt(const char *, const char *);
80 int	ismounted(struct fstab *, struct statfs *, int);
81 int	isremountable(const char *);
82 void	mangle(char *, struct cpa *);
83 char   *update_options(char *, char *, int);
84 int	mountfs(const char *, const char *, const char *,
85 			int, const char *, const char *);
86 void	remopt(char *, const char *);
87 void	prmount(struct statfs *);
88 void	putfsent(struct statfs *);
89 void	usage(void);
90 char   *flags2opts(int);
91 
92 /* Map from mount options to printable formats. */
93 static struct opt {
94 	uint64_t o_opt;
95 	const char *o_name;
96 } optnames[] = {
97 	{ MNT_ASYNC,		"asynchronous" },
98 	{ MNT_EXPORTED,		"NFS exported" },
99 	{ MNT_LOCAL,		"local" },
100 	{ MNT_NOATIME,		"noatime" },
101 	{ MNT_NOEXEC,		"noexec" },
102 	{ MNT_NOSUID,		"nosuid" },
103 	{ MNT_NOSYMFOLLOW,	"nosymfollow" },
104 	{ MNT_QUOTA,		"with quotas" },
105 	{ MNT_RDONLY,		"read-only" },
106 	{ MNT_SYNCHRONOUS,	"synchronous" },
107 	{ MNT_UNION,		"union" },
108 	{ MNT_NOCLUSTERR,	"noclusterr" },
109 	{ MNT_NOCLUSTERW,	"noclusterw" },
110 	{ MNT_SUIDDIR,		"suiddir" },
111 	{ MNT_SOFTDEP,		"soft-updates" },
112 	{ MNT_SUJ,		"journaled soft-updates" },
113 	{ MNT_MULTILABEL,	"multilabel" },
114 	{ MNT_ACLS,		"acls" },
115 	{ MNT_NFS4ACLS,		"nfsv4acls" },
116 	{ MNT_GJOURNAL,		"gjournal" },
117 	{ MNT_AUTOMOUNTED,	"automounted" },
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  */
126 static const char *
127 remountable_fs_names[] = {
128 	"ufs", "ffs", "ext2fs",
129 	0
130 };
131 
132 static const char userquotaeq[] = "userquota=";
133 static const char groupquotaeq[] = "groupquota=";
134 
135 static char *mountprog = NULL;
136 
137 static int
138 use_mountprog(const char *vfstype)
139 {
140 	/* XXX: We need to get away from implementing external mount
141 	 *      programs for every filesystem, and move towards having
142 	 *	each filesystem properly implement the nmount() system call.
143 	 */
144 	unsigned int i;
145 	const char *fs[] = {
146 	"cd9660", "mfs", "msdosfs", "nfs",
147 	"nullfs", "smbfs", "udf", "unionfs",
148 	NULL
149 	};
150 
151 	if (mountprog != NULL)
152 		return (1);
153 
154 	for (i = 0; fs[i] != NULL; ++i) {
155 		if (strcmp(vfstype, fs[i]) == 0)
156 			return (1);
157 	}
158 
159 	return (0);
160 }
161 
162 static int
163 exec_mountprog(const char *name, const char *execname, char *const argv[])
164 {
165 	pid_t pid;
166 	int status;
167 
168 	switch (pid = fork()) {
169 	case -1:				/* Error. */
170 		warn("fork");
171 		exit (1);
172 	case 0:					/* Child. */
173 		/* Go find an executable. */
174 		execvP(execname, _PATH_SYSPATH, argv);
175 		if (errno == ENOENT) {
176 			warn("exec %s not found", execname);
177 			if (execname[0] != '/') {
178 				warnx("in path: %s", _PATH_SYSPATH);
179 			}
180 		}
181 		exit(1);
182 	default:				/* Parent. */
183 		if (waitpid(pid, &status, 0) < 0) {
184 			warn("waitpid");
185 			return (1);
186 		}
187 
188 		if (WIFEXITED(status)) {
189 			if (WEXITSTATUS(status) != 0)
190 				return (WEXITSTATUS(status));
191 		} else if (WIFSIGNALED(status)) {
192 			warnx("%s: %s", name, sys_siglist[WTERMSIG(status)]);
193 			return (1);
194 		}
195 		break;
196 	}
197 
198 	return (0);
199 }
200 
201 static int
202 specified_ro(const char *arg)
203 {
204 	char *optbuf, *opt;
205 	int ret = 0;
206 
207 	optbuf = strdup(arg);
208 	if (optbuf == NULL)
209 		 err(1, NULL);
210 
211 	for (opt = optbuf; (opt = strtok(opt, ",")) != NULL; opt = NULL) {
212 		if (strcmp(opt, "ro") == 0) {
213 			ret = 1;
214 			break;
215 		}
216 	}
217 	free(optbuf);
218 	return (ret);
219 }
220 
221 static void
222 restart_mountd(void)
223 {
224 	struct pidfh *pfh;
225 	pid_t mountdpid;
226 
227 	pfh = pidfile_open(_PATH_MOUNTDPID, 0600, &mountdpid);
228 	if (pfh != NULL) {
229 		/* Mountd is not running. */
230 		pidfile_remove(pfh);
231 		return;
232 	}
233 	if (errno != EEXIST) {
234 		/* Cannot open pidfile for some reason. */
235 		return;
236 	}
237 	/* We have mountd(8) PID in mountdpid varible, let's signal it. */
238 	if (kill(mountdpid, SIGHUP) == -1)
239 		err(1, "signal mountd");
240 }
241 
242 int
243 main(int argc, char *argv[])
244 {
245 	const char *mntfromname, **vfslist, *vfstype;
246 	struct fstab *fs;
247 	struct statfs *mntbuf;
248 	int all, ch, i, init_flags, late, failok, mntsize, rval, have_fstab, ro;
249 	int onlylate;
250 	char *cp, *ep, *options;
251 
252 	all = init_flags = late = onlylate = 0;
253 	ro = 0;
254 	options = NULL;
255 	vfslist = NULL;
256 	vfstype = "ufs";
257 	while ((ch = getopt(argc, argv, "adF:fLlno:prt:uvw")) != -1)
258 		switch (ch) {
259 		case 'a':
260 			all = 1;
261 			break;
262 		case 'd':
263 			debug = 1;
264 			break;
265 		case 'F':
266 			setfstab(optarg);
267 			break;
268 		case 'f':
269 			init_flags |= MNT_FORCE;
270 			break;
271 		case 'L':
272 			onlylate = 1;
273 			late = 1;
274 			break;
275 		case 'l':
276 			late = 1;
277 			break;
278 		case 'n':
279 			/* For compatibility with the Linux version of mount. */
280 			break;
281 		case 'o':
282 			if (*optarg) {
283 				options = catopt(options, optarg);
284 				if (specified_ro(optarg))
285 					ro = 1;
286 			}
287 			break;
288 		case 'p':
289 			fstab_style = 1;
290 			verbose = 1;
291 			break;
292 		case 'r':
293 			options = catopt(options, "ro");
294 			ro = 1;
295 			break;
296 		case 't':
297 			if (vfslist != NULL)
298 				errx(1, "only one -t option may be specified");
299 			vfslist = makevfslist(optarg);
300 			vfstype = optarg;
301 			break;
302 		case 'u':
303 			init_flags |= MNT_UPDATE;
304 			break;
305 		case 'v':
306 			verbose = 1;
307 			break;
308 		case 'w':
309 			options = catopt(options, "noro");
310 			break;
311 		case '?':
312 		default:
313 			usage();
314 			/* NOTREACHED */
315 		}
316 	argc -= optind;
317 	argv += optind;
318 
319 #define	BADTYPE(type)							\
320 	(strcmp(type, FSTAB_RO) &&					\
321 	    strcmp(type, FSTAB_RW) && strcmp(type, FSTAB_RQ))
322 
323 	if ((init_flags & MNT_UPDATE) && (ro == 0))
324 		options = catopt(options, "noro");
325 
326 	rval = 0;
327 	switch (argc) {
328 	case 0:
329 		if ((mntsize = getmntinfo(&mntbuf, MNT_NOWAIT)) == 0)
330 			err(1, "getmntinfo");
331 		if (all) {
332 			while ((fs = getfsent()) != NULL) {
333 				if (BADTYPE(fs->fs_type))
334 					continue;
335 				if (checkvfsname(fs->fs_vfstype, vfslist))
336 					continue;
337 				if (hasopt(fs->fs_mntops, "noauto"))
338 					continue;
339 				if (!hasopt(fs->fs_mntops, "late") && onlylate)
340 					continue;
341 				if (hasopt(fs->fs_mntops, "late") && !late)
342 					continue;
343 				if (hasopt(fs->fs_mntops, "failok"))
344 					failok = 1;
345 				else
346 					failok = 0;
347 				if (!(init_flags & MNT_UPDATE) &&
348 				    ismounted(fs, mntbuf, mntsize))
349 					continue;
350 				options = update_options(options, fs->fs_mntops,
351 				    mntbuf->f_flags);
352 				if (mountfs(fs->fs_vfstype, fs->fs_spec,
353 				    fs->fs_file, init_flags, options,
354 				    fs->fs_mntops) && !failok)
355 					rval = 1;
356 			}
357 		} else if (fstab_style) {
358 			for (i = 0; i < mntsize; i++) {
359 				if (checkvfsname(mntbuf[i].f_fstypename, vfslist))
360 					continue;
361 				putfsent(&mntbuf[i]);
362 			}
363 		} else {
364 			for (i = 0; i < mntsize; i++) {
365 				if (checkvfsname(mntbuf[i].f_fstypename,
366 				    vfslist))
367 					continue;
368 				if (!verbose &&
369 				    (mntbuf[i].f_flags & MNT_IGNORE) != 0)
370 					continue;
371 				prmount(&mntbuf[i]);
372 			}
373 		}
374 		exit(rval);
375 	case 1:
376 		if (vfslist != NULL)
377 			usage();
378 
379 		rmslashes(*argv, *argv);
380 		if (init_flags & MNT_UPDATE) {
381 			mntfromname = NULL;
382 			have_fstab = 0;
383 			if ((mntbuf = getmntpt(*argv)) == NULL)
384 				errx(1, "not currently mounted %s", *argv);
385 			/*
386 			 * Only get the mntflags from fstab if both mntpoint
387 			 * and mntspec are identical. Also handle the special
388 			 * case where just '/' is mounted and 'spec' is not
389 			 * identical with the one from fstab ('/dev' is missing
390 			 * in the spec-string at boot-time).
391 			 */
392 			if ((fs = getfsfile(mntbuf->f_mntonname)) != NULL) {
393 				if (strcmp(fs->fs_spec,
394 				    mntbuf->f_mntfromname) == 0 &&
395 				    strcmp(fs->fs_file,
396 				    mntbuf->f_mntonname) == 0) {
397 					have_fstab = 1;
398 					mntfromname = mntbuf->f_mntfromname;
399 				} else if (argv[0][0] == '/' &&
400 				    argv[0][1] == '\0') {
401 					fs = getfsfile("/");
402 					have_fstab = 1;
403 					mntfromname = fs->fs_spec;
404 				}
405 			}
406 			if (have_fstab) {
407 				options = update_options(options, fs->fs_mntops,
408 				    mntbuf->f_flags);
409 			} else {
410 				mntfromname = mntbuf->f_mntfromname;
411 				options = update_options(options, NULL,
412 				    mntbuf->f_flags);
413 			}
414 			rval = mountfs(mntbuf->f_fstypename, mntfromname,
415 			    mntbuf->f_mntonname, init_flags, options, 0);
416 			break;
417 		}
418 		if ((fs = getfsfile(*argv)) == NULL &&
419 		    (fs = getfsspec(*argv)) == NULL)
420 			errx(1, "%s: unknown special file or file system",
421 			    *argv);
422 		if (BADTYPE(fs->fs_type))
423 			errx(1, "%s has unknown file system type",
424 			    *argv);
425 		rval = mountfs(fs->fs_vfstype, fs->fs_spec, fs->fs_file,
426 		    init_flags, options, fs->fs_mntops);
427 		break;
428 	case 2:
429 		/*
430 		 * If -t flag has not been specified, the path cannot be
431 		 * found, spec contains either a ':' or a '@', then assume
432 		 * that an NFS file system is being specified ala Sun.
433 		 * Check if the hostname contains only allowed characters
434 		 * to reduce false positives.  IPv6 addresses containing
435 		 * ':' will be correctly parsed only if the separator is '@'.
436 		 * The definition of a valid hostname is taken from RFC 1034.
437 		 */
438 		if (vfslist == NULL && ((ep = strchr(argv[0], '@')) != NULL ||
439 		    (ep = strchr(argv[0], ':')) != NULL)) {
440 			if (*ep == '@') {
441 				cp = ep + 1;
442 				ep = cp + strlen(cp);
443 			} else
444 				cp = argv[0];
445 			while (cp != ep) {
446 				if (!isdigit(*cp) && !isalpha(*cp) &&
447 				    *cp != '.' && *cp != '-' && *cp != ':')
448 					break;
449 				cp++;
450 			}
451 			if (cp == ep)
452 				vfstype = "nfs";
453 		}
454 		rval = mountfs(vfstype,
455 		    argv[0], argv[1], init_flags, options, NULL);
456 		break;
457 	default:
458 		usage();
459 		/* NOTREACHED */
460 	}
461 
462 	/*
463 	 * If the mount was successfully, and done by root, tell mountd the
464 	 * good news.
465 	 */
466 	if (rval == 0 && getuid() == 0)
467 		restart_mountd();
468 
469 	exit(rval);
470 }
471 
472 int
473 ismounted(struct fstab *fs, struct statfs *mntbuf, int mntsize)
474 {
475 	char realfsfile[PATH_MAX];
476 	int i;
477 
478 	if (fs->fs_file[0] == '/' && fs->fs_file[1] == '\0')
479 		/* the root file system can always be remounted */
480 		return (0);
481 
482 	/* The user may have specified a symlink in fstab, resolve the path */
483 	if (realpath(fs->fs_file, realfsfile) == NULL) {
484 		/* Cannot resolve the path, use original one */
485 		strlcpy(realfsfile, fs->fs_file, sizeof(realfsfile));
486 	}
487 
488 	/*
489 	 * Consider the filesystem to be mounted if:
490 	 * It has the same mountpoint as a mounted filesytem, and
491 	 * It has the same type as that same mounted filesystem, and
492 	 * It has the same device name as that same mounted filesystem, OR
493 	 *     It is a nonremountable filesystem
494 	 */
495 	for (i = mntsize - 1; i >= 0; --i)
496 		if (strcmp(realfsfile, mntbuf[i].f_mntonname) == 0 &&
497 		    strcmp(fs->fs_vfstype, mntbuf[i].f_fstypename) == 0 &&
498 		    (!isremountable(fs->fs_vfstype) ||
499 		     (strcmp(fs->fs_spec, mntbuf[i].f_mntfromname) == 0)))
500 			return (1);
501 	return (0);
502 }
503 
504 int
505 isremountable(const char *vfsname)
506 {
507 	const char **cp;
508 
509 	for (cp = remountable_fs_names; *cp; cp++)
510 		if (strcmp(*cp, vfsname) == 0)
511 			return (1);
512 	return (0);
513 }
514 
515 int
516 hasopt(const char *mntopts, const char *option)
517 {
518 	int negative, found;
519 	char *opt, *optbuf;
520 
521 	if (option[0] == 'n' && option[1] == 'o') {
522 		negative = 1;
523 		option += 2;
524 	} else
525 		negative = 0;
526 	optbuf = strdup(mntopts);
527 	found = 0;
528 	for (opt = optbuf; (opt = strtok(opt, ",")) != NULL; opt = NULL) {
529 		if (opt[0] == 'n' && opt[1] == 'o') {
530 			if (!strcasecmp(opt + 2, option))
531 				found = negative;
532 		} else if (!strcasecmp(opt, option))
533 			found = !negative;
534 	}
535 	free(optbuf);
536 	return (found);
537 }
538 
539 static void
540 append_arg(struct cpa *sa, char *arg)
541 {
542 	if (sa->c + 1 == sa->sz) {
543 		sa->sz = sa->sz == 0 ? 8 : sa->sz * 2;
544 		sa->a = realloc(sa->a, sizeof(*sa->a) * sa->sz);
545 		if (sa->a == NULL)
546 			errx(1, "realloc failed");
547 	}
548 	sa->a[++sa->c] = arg;
549 }
550 
551 int
552 mountfs(const char *vfstype, const char *spec, const char *name, int flags,
553 	const char *options, const char *mntopts)
554 {
555 	struct statfs sf;
556 	int i, ret;
557 	char *optbuf, execname[PATH_MAX], mntpath[PATH_MAX];
558 	static struct cpa mnt_argv;
559 
560 	/* resolve the mountpoint with realpath(3) */
561 	if (checkpath(name, mntpath) != 0) {
562 		warn("%s", mntpath);
563 		return (1);
564 	}
565 	name = mntpath;
566 
567 	if (mntopts == NULL)
568 		mntopts = "";
569 	optbuf = catopt(strdup(mntopts), options);
570 
571 	if (strcmp(name, "/") == 0)
572 		flags |= MNT_UPDATE;
573 	if (flags & MNT_FORCE)
574 		optbuf = catopt(optbuf, "force");
575 	if (flags & MNT_RDONLY)
576 		optbuf = catopt(optbuf, "ro");
577 	/*
578 	 * XXX
579 	 * The mount_mfs (newfs) command uses -o to select the
580 	 * optimization mode.  We don't pass the default "-o rw"
581 	 * for that reason.
582 	 */
583 	if (flags & MNT_UPDATE)
584 		optbuf = catopt(optbuf, "update");
585 
586 	/* Compatibility glue. */
587 	if (strcmp(vfstype, "msdos") == 0) {
588 		warnx(
589 		    "Using \"-t msdosfs\", since \"-t msdos\" is deprecated.");
590 		vfstype = "msdosfs";
591 	}
592 
593 	/* Construct the name of the appropriate mount command */
594 	(void)snprintf(execname, sizeof(execname), "mount_%s", vfstype);
595 
596 	mnt_argv.c = -1;
597 	append_arg(&mnt_argv, execname);
598 	mangle(optbuf, &mnt_argv);
599 	if (mountprog != NULL)
600 		strcpy(execname, mountprog);
601 
602 	append_arg(&mnt_argv, strdup(spec));
603 	append_arg(&mnt_argv, strdup(name));
604 	append_arg(&mnt_argv, NULL);
605 
606 	if (debug) {
607 		if (use_mountprog(vfstype))
608 			printf("exec: %s", execname);
609 		else
610 			printf("mount -t %s", vfstype);
611 		for (i = 1; i < mnt_argv.c; i++)
612 			(void)printf(" %s", mnt_argv.a[i]);
613 		(void)printf("\n");
614 		free(optbuf);
615 		free(mountprog);
616 		mountprog = NULL;
617 		return (0);
618 	}
619 
620 	if (use_mountprog(vfstype)) {
621 		ret = exec_mountprog(name, execname, mnt_argv.a);
622 	} else {
623 		ret = mount_fs(vfstype, mnt_argv.c, mnt_argv.a);
624 	}
625 
626 	free(optbuf);
627 	free(mountprog);
628 	mountprog = NULL;
629 
630 	if (verbose) {
631 		if (statfs(name, &sf) < 0) {
632 			warn("statfs %s", name);
633 			return (1);
634 		}
635 		if (fstab_style)
636 			putfsent(&sf);
637 		else
638 			prmount(&sf);
639 	}
640 
641 	return (ret);
642 }
643 
644 void
645 prmount(struct statfs *sfp)
646 {
647 	uint64_t flags;
648 	unsigned int i;
649 	struct opt *o;
650 	struct passwd *pw;
651 
652 	(void)printf("%s on %s (%s", sfp->f_mntfromname, sfp->f_mntonname,
653 	    sfp->f_fstypename);
654 
655 	flags = sfp->f_flags & MNT_VISFLAGMASK;
656 	for (o = optnames; flags != 0 && o->o_opt != 0; o++)
657 		if (flags & o->o_opt) {
658 			(void)printf(", %s", o->o_name);
659 			flags &= ~o->o_opt;
660 		}
661 	/*
662 	 * Inform when file system is mounted by an unprivileged user
663 	 * or privileged non-root user.
664 	 */
665 	if ((flags & MNT_USER) != 0 || sfp->f_owner != 0) {
666 		(void)printf(", mounted by ");
667 		if ((pw = getpwuid(sfp->f_owner)) != NULL)
668 			(void)printf("%s", pw->pw_name);
669 		else
670 			(void)printf("%d", sfp->f_owner);
671 	}
672 	if (verbose) {
673 		if (sfp->f_syncwrites != 0 || sfp->f_asyncwrites != 0)
674 			(void)printf(", writes: sync %ju async %ju",
675 			    (uintmax_t)sfp->f_syncwrites,
676 			    (uintmax_t)sfp->f_asyncwrites);
677 		if (sfp->f_syncreads != 0 || sfp->f_asyncreads != 0)
678 			(void)printf(", reads: sync %ju async %ju",
679 			    (uintmax_t)sfp->f_syncreads,
680 			    (uintmax_t)sfp->f_asyncreads);
681 		if (sfp->f_fsid.val[0] != 0 || sfp->f_fsid.val[1] != 0) {
682 			printf(", fsid ");
683 			for (i = 0; i < sizeof(sfp->f_fsid); i++)
684 				printf("%02x", ((u_char *)&sfp->f_fsid)[i]);
685 		}
686 	}
687 	(void)printf(")\n");
688 }
689 
690 struct statfs *
691 getmntpt(const char *name)
692 {
693 	struct statfs *mntbuf;
694 	int i, mntsize;
695 
696 	mntsize = getmntinfo(&mntbuf, MNT_NOWAIT);
697 	for (i = mntsize - 1; i >= 0; i--) {
698 		if (strcmp(mntbuf[i].f_mntfromname, name) == 0 ||
699 		    strcmp(mntbuf[i].f_mntonname, name) == 0)
700 			return (&mntbuf[i]);
701 	}
702 	return (NULL);
703 }
704 
705 char *
706 catopt(char *s0, const char *s1)
707 {
708 	char *cp;
709 
710 	if (s1 == NULL || *s1 == '\0')
711 		return (s0);
712 
713 	if (s0 && *s0) {
714 		if (asprintf(&cp, "%s,%s", s0, s1) == -1)
715 			errx(1, "asprintf failed");
716 	} else
717 		cp = strdup(s1);
718 
719 	if (s0)
720 		free(s0);
721 	return (cp);
722 }
723 
724 void
725 mangle(char *options, struct cpa *a)
726 {
727 	char *p, *s, *val;
728 
729 	for (s = options; (p = strsep(&s, ",")) != NULL;)
730 		if (*p != '\0') {
731 			if (strcmp(p, "noauto") == 0) {
732 				/*
733 				 * Do not pass noauto option to nmount().
734 				 * or external mount program.  noauto is
735 				 * only used to prevent mounting a filesystem
736 				 * when 'mount -a' is specified, and is
737 				 * not a real mount option.
738 				 */
739 				continue;
740 			} else if (strcmp(p, "late") == 0) {
741 				/*
742 				 * "late" is used to prevent certain file
743 				 * systems from being mounted before late
744 				 * in the boot cycle; for instance,
745 				 * loopback NFS mounts can't be mounted
746 				 * before mountd starts.
747 				 */
748 				continue;
749 			} else if (strcmp(p, "failok") == 0) {
750 				/*
751 				 * "failok" is used to prevent certain file
752 				 * systems from being causing the system to
753 				 * drop into single user mode in the boot
754 				 * cycle, and is not a real mount option.
755 				 */
756 				continue;
757 			} else if (strncmp(p, "mountprog", 9) == 0) {
758 				/*
759 				 * "mountprog" is used to force the use of
760 				 * userland mount programs.
761 				 */
762 				val = strchr(p, '=');
763                         	if (val != NULL) {
764                                 	++val;
765 					if (*val != '\0')
766 						mountprog = strdup(val);
767 				}
768 
769 				if (mountprog == NULL) {
770 					errx(1, "Need value for -o mountprog");
771 				}
772 				continue;
773 			} else if (strcmp(p, "userquota") == 0) {
774 				continue;
775 			} else if (strncmp(p, userquotaeq,
776 			    sizeof(userquotaeq) - 1) == 0) {
777 				continue;
778 			} else if (strcmp(p, "groupquota") == 0) {
779 				continue;
780 			} else if (strncmp(p, groupquotaeq,
781 			    sizeof(groupquotaeq) - 1) == 0) {
782 				continue;
783 			} else if (*p == '-') {
784 				append_arg(a, p);
785 				p = strchr(p, '=');
786 				if (p != NULL) {
787 					*p = '\0';
788 					append_arg(a, p + 1);
789 				}
790 			} else {
791 				append_arg(a, strdup("-o"));
792 				append_arg(a, p);
793 			}
794 		}
795 }
796 
797 
798 char *
799 update_options(char *opts, char *fstab, int curflags)
800 {
801 	char *o, *p;
802 	char *cur;
803 	char *expopt, *newopt, *tmpopt;
804 
805 	if (opts == NULL)
806 		return (strdup(""));
807 
808 	/* remove meta options from list */
809 	remopt(fstab, MOUNT_META_OPTION_FSTAB);
810 	remopt(fstab, MOUNT_META_OPTION_CURRENT);
811 	cur = flags2opts(curflags);
812 
813 	/*
814 	 * Expand all meta-options passed to us first.
815 	 */
816 	expopt = NULL;
817 	for (p = opts; (o = strsep(&p, ",")) != NULL;) {
818 		if (strcmp(MOUNT_META_OPTION_FSTAB, o) == 0)
819 			expopt = catopt(expopt, fstab);
820 		else if (strcmp(MOUNT_META_OPTION_CURRENT, o) == 0)
821 			expopt = catopt(expopt, cur);
822 		else
823 			expopt = catopt(expopt, o);
824 	}
825 	free(cur);
826 	free(opts);
827 
828 	/*
829 	 * Remove previous contradictory arguments. Given option "foo" we
830 	 * remove all the "nofoo" options. Given "nofoo" we remove "nonofoo"
831 	 * and "foo" - so we can deal with possible options like "notice".
832 	 */
833 	newopt = NULL;
834 	for (p = expopt; (o = strsep(&p, ",")) != NULL;) {
835 		if ((tmpopt = malloc( strlen(o) + 2 + 1 )) == NULL)
836 			errx(1, "malloc failed");
837 
838 		strcpy(tmpopt, "no");
839 		strcat(tmpopt, o);
840 		remopt(newopt, tmpopt);
841 		free(tmpopt);
842 
843 		if (strncmp("no", o, 2) == 0)
844 			remopt(newopt, o+2);
845 
846 		newopt = catopt(newopt, o);
847 	}
848 	free(expopt);
849 
850 	return (newopt);
851 }
852 
853 void
854 remopt(char *string, const char *opt)
855 {
856 	char *o, *p, *r;
857 
858 	if (string == NULL || *string == '\0' || opt == NULL || *opt == '\0')
859 		return;
860 
861 	r = string;
862 
863 	for (p = string; (o = strsep(&p, ",")) != NULL;) {
864 		if (strcmp(opt, o) != 0) {
865 			if (*r == ',' && *o != '\0')
866 				r++;
867 			while ((*r++ = *o++) != '\0')
868 			    ;
869 			*--r = ',';
870 		}
871 	}
872 	*r = '\0';
873 }
874 
875 void
876 usage(void)
877 {
878 
879 	(void)fprintf(stderr, "%s\n%s\n%s\n",
880 "usage: mount [-adflpruvw] [-F fstab] [-o options] [-t ufs | external_type]",
881 "       mount [-dfpruvw] special | node",
882 "       mount [-dfpruvw] [-o options] [-t ufs | external_type] special node");
883 	exit(1);
884 }
885 
886 void
887 putfsent(struct statfs *ent)
888 {
889 	struct fstab *fst;
890 	char *opts, *rw;
891 	int l;
892 
893 	opts = NULL;
894 	/* flags2opts() doesn't return the "rw" option. */
895 	if ((ent->f_flags & MNT_RDONLY) != 0)
896 		rw = NULL;
897 	else
898 		rw = catopt(NULL, "rw");
899 
900 	opts = flags2opts(ent->f_flags);
901 	opts = catopt(rw, opts);
902 
903 	if (strncmp(ent->f_mntfromname, "<below>", 7) == 0 ||
904 	    strncmp(ent->f_mntfromname, "<above>", 7) == 0) {
905 		strcpy(ent->f_mntfromname, (strnstr(ent->f_mntfromname, ":", 8)
906 		    +1));
907 	}
908 
909 	l = strlen(ent->f_mntfromname);
910 	printf("%s%s%s%s", ent->f_mntfromname,
911 	    l < 8 ? "\t" : "",
912 	    l < 16 ? "\t" : "",
913 	    l < 24 ? "\t" : " ");
914 	l = strlen(ent->f_mntonname);
915 	printf("%s%s%s%s", ent->f_mntonname,
916 	    l < 8 ? "\t" : "",
917 	    l < 16 ? "\t" : "",
918 	    l < 24 ? "\t" : " ");
919 	printf("%s\t", ent->f_fstypename);
920 	l = strlen(opts);
921 	printf("%s%s", opts,
922 	    l < 8 ? "\t" : " ");
923 	free(opts);
924 
925 	if ((fst = getfsspec(ent->f_mntfromname)))
926 		printf("\t%u %u\n", fst->fs_freq, fst->fs_passno);
927 	else if ((fst = getfsfile(ent->f_mntonname)))
928 		printf("\t%u %u\n", fst->fs_freq, fst->fs_passno);
929 	else if (strcmp(ent->f_fstypename, "ufs") == 0) {
930 		if (strcmp(ent->f_mntonname, "/") == 0)
931 			printf("\t1 1\n");
932 		else
933 			printf("\t2 2\n");
934 	} else
935 		printf("\t0 0\n");
936 }
937 
938 
939 char *
940 flags2opts(int flags)
941 {
942 	char *res;
943 
944 	res = NULL;
945 
946 	if (flags & MNT_RDONLY)		res = catopt(res, "ro");
947 	if (flags & MNT_SYNCHRONOUS)	res = catopt(res, "sync");
948 	if (flags & MNT_NOEXEC)		res = catopt(res, "noexec");
949 	if (flags & MNT_NOSUID)		res = catopt(res, "nosuid");
950 	if (flags & MNT_UNION)		res = catopt(res, "union");
951 	if (flags & MNT_ASYNC)		res = catopt(res, "async");
952 	if (flags & MNT_NOATIME)	res = catopt(res, "noatime");
953 	if (flags & MNT_NOCLUSTERR)	res = catopt(res, "noclusterr");
954 	if (flags & MNT_NOCLUSTERW)	res = catopt(res, "noclusterw");
955 	if (flags & MNT_NOSYMFOLLOW)	res = catopt(res, "nosymfollow");
956 	if (flags & MNT_SUIDDIR)	res = catopt(res, "suiddir");
957 	if (flags & MNT_MULTILABEL)	res = catopt(res, "multilabel");
958 	if (flags & MNT_ACLS)		res = catopt(res, "acls");
959 	if (flags & MNT_NFS4ACLS)	res = catopt(res, "nfsv4acls");
960 
961 	return (res);
962 }
963