xref: /freebsd/sbin/mount/mount.c (revision eb69d1f144a6fcc765d1b9d44a5ae8082353e70b)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1980, 1989, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #ifndef lint
33 static const char copyright[] =
34 "@(#) Copyright (c) 1980, 1989, 1993, 1994\n\
35 	The Regents of the University of California.  All rights reserved.\n";
36 #if 0
37 static char sccsid[] = "@(#)mount.c	8.25 (Berkeley) 5/8/95";
38 #endif
39 #endif /* not lint */
40 
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD$");
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 static int debug, fstab_style, verbose;
72 
73 struct cpa {
74 	char	**a;
75 	ssize_t	sz;
76 	int	c;
77 };
78 
79 char   *catopt(char *, const char *);
80 struct statfs *getmntpt(const char *);
81 int	hasopt(const char *, const char *);
82 int	ismounted(struct fstab *, struct statfs *, int);
83 int	isremountable(const char *);
84 void	mangle(char *, struct cpa *);
85 char   *update_options(char *, char *, int);
86 int	mountfs(const char *, const char *, const char *,
87 			int, const char *, const char *);
88 void	remopt(char *, const char *);
89 void	prmount(struct statfs *);
90 void	putfsent(struct statfs *);
91 void	usage(void);
92 char   *flags2opts(int);
93 
94 /* Map from mount options to printable formats. */
95 static struct opt {
96 	uint64_t o_opt;
97 	const char *o_name;
98 } optnames[] = {
99 	{ MNT_ASYNC,		"asynchronous" },
100 	{ MNT_EXPORTED,		"NFS exported" },
101 	{ MNT_LOCAL,		"local" },
102 	{ MNT_NOATIME,		"noatime" },
103 	{ MNT_NOEXEC,		"noexec" },
104 	{ MNT_NOSUID,		"nosuid" },
105 	{ MNT_NOSYMFOLLOW,	"nosymfollow" },
106 	{ MNT_QUOTA,		"with quotas" },
107 	{ MNT_RDONLY,		"read-only" },
108 	{ MNT_SYNCHRONOUS,	"synchronous" },
109 	{ MNT_UNION,		"union" },
110 	{ MNT_NOCLUSTERR,	"noclusterr" },
111 	{ MNT_NOCLUSTERW,	"noclusterw" },
112 	{ MNT_SUIDDIR,		"suiddir" },
113 	{ MNT_SOFTDEP,		"soft-updates" },
114 	{ MNT_SUJ,		"journaled soft-updates" },
115 	{ MNT_MULTILABEL,	"multilabel" },
116 	{ MNT_ACLS,		"acls" },
117 	{ MNT_NFS4ACLS,		"nfsv4acls" },
118 	{ MNT_GJOURNAL,		"gjournal" },
119 	{ MNT_AUTOMOUNTED,	"automounted" },
120 	{ MNT_VERIFIED,		"verified" },
121 	{ 0, NULL }
122 };
123 
124 /*
125  * List of VFS types that can be remounted without becoming mounted on top
126  * of each other.
127  * XXX Is this list correct?
128  */
129 static const char *
130 remountable_fs_names[] = {
131 	"ufs", "ffs", "ext2fs",
132 	0
133 };
134 
135 static const char userquotaeq[] = "userquota=";
136 static const char groupquotaeq[] = "groupquota=";
137 
138 static char *mountprog = NULL;
139 
140 static int
141 use_mountprog(const char *vfstype)
142 {
143 	/* XXX: We need to get away from implementing external mount
144 	 *      programs for every filesystem, and move towards having
145 	 *	each filesystem properly implement the nmount() system call.
146 	 */
147 	unsigned int i;
148 	const char *fs[] = {
149 	"cd9660", "mfs", "msdosfs", "nfs",
150 	"nullfs", "smbfs", "udf", "unionfs",
151 	NULL
152 	};
153 
154 	if (mountprog != NULL)
155 		return (1);
156 
157 	for (i = 0; fs[i] != NULL; ++i) {
158 		if (strcmp(vfstype, fs[i]) == 0)
159 			return (1);
160 	}
161 
162 	return (0);
163 }
164 
165 static int
166 exec_mountprog(const char *name, const char *execname, char *const argv[])
167 {
168 	pid_t pid;
169 	int status;
170 
171 	switch (pid = fork()) {
172 	case -1:				/* Error. */
173 		warn("fork");
174 		exit (1);
175 	case 0:					/* Child. */
176 		/* Go find an executable. */
177 		execvP(execname, _PATH_SYSPATH, argv);
178 		if (errno == ENOENT) {
179 			warn("exec %s not found", execname);
180 			if (execname[0] != '/') {
181 				warnx("in path: %s", _PATH_SYSPATH);
182 			}
183 		}
184 		exit(1);
185 	default:				/* Parent. */
186 		if (waitpid(pid, &status, 0) < 0) {
187 			warn("waitpid");
188 			return (1);
189 		}
190 
191 		if (WIFEXITED(status)) {
192 			if (WEXITSTATUS(status) != 0)
193 				return (WEXITSTATUS(status));
194 		} else if (WIFSIGNALED(status)) {
195 			warnx("%s: %s", name, sys_siglist[WTERMSIG(status)]);
196 			return (1);
197 		}
198 		break;
199 	}
200 
201 	return (0);
202 }
203 
204 static int
205 specified_ro(const char *arg)
206 {
207 	char *optbuf, *opt;
208 	int ret = 0;
209 
210 	optbuf = strdup(arg);
211 	if (optbuf == NULL)
212 		 err(1, NULL);
213 
214 	for (opt = optbuf; (opt = strtok(opt, ",")) != NULL; opt = NULL) {
215 		if (strcmp(opt, "ro") == 0) {
216 			ret = 1;
217 			break;
218 		}
219 	}
220 	free(optbuf);
221 	return (ret);
222 }
223 
224 static void
225 restart_mountd(void)
226 {
227 	struct pidfh *pfh;
228 	pid_t mountdpid;
229 
230 	pfh = pidfile_open(_PATH_MOUNTDPID, 0600, &mountdpid);
231 	if (pfh != NULL) {
232 		/* Mountd is not running. */
233 		pidfile_remove(pfh);
234 		return;
235 	}
236 	if (errno != EEXIST) {
237 		/* Cannot open pidfile for some reason. */
238 		return;
239 	}
240 	/* We have mountd(8) PID in mountdpid varible, let's signal it. */
241 	if (kill(mountdpid, SIGHUP) == -1)
242 		err(1, "signal mountd");
243 }
244 
245 int
246 main(int argc, char *argv[])
247 {
248 	const char *mntfromname, **vfslist, *vfstype;
249 	struct fstab *fs;
250 	struct statfs *mntbuf;
251 	int all, ch, i, init_flags, late, failok, mntsize, rval, have_fstab, ro;
252 	int onlylate;
253 	char *cp, *ep, *options;
254 
255 	all = init_flags = late = onlylate = 0;
256 	ro = 0;
257 	options = NULL;
258 	vfslist = NULL;
259 	vfstype = "ufs";
260 	while ((ch = getopt(argc, argv, "adF:fLlno:prt:uvw")) != -1)
261 		switch (ch) {
262 		case 'a':
263 			all = 1;
264 			break;
265 		case 'd':
266 			debug = 1;
267 			break;
268 		case 'F':
269 			setfstab(optarg);
270 			break;
271 		case 'f':
272 			init_flags |= MNT_FORCE;
273 			break;
274 		case 'L':
275 			onlylate = 1;
276 			late = 1;
277 			break;
278 		case 'l':
279 			late = 1;
280 			break;
281 		case 'n':
282 			/* For compatibility with the Linux version of mount. */
283 			break;
284 		case 'o':
285 			if (*optarg) {
286 				options = catopt(options, optarg);
287 				if (specified_ro(optarg))
288 					ro = 1;
289 			}
290 			break;
291 		case 'p':
292 			fstab_style = 1;
293 			verbose = 1;
294 			break;
295 		case 'r':
296 			options = catopt(options, "ro");
297 			ro = 1;
298 			break;
299 		case 't':
300 			if (vfslist != NULL)
301 				errx(1, "only one -t option may be specified");
302 			vfslist = makevfslist(optarg);
303 			vfstype = optarg;
304 			break;
305 		case 'u':
306 			init_flags |= MNT_UPDATE;
307 			break;
308 		case 'v':
309 			verbose = 1;
310 			break;
311 		case 'w':
312 			options = catopt(options, "noro");
313 			break;
314 		case '?':
315 		default:
316 			usage();
317 			/* NOTREACHED */
318 		}
319 	argc -= optind;
320 	argv += optind;
321 
322 #define	BADTYPE(type)							\
323 	(strcmp(type, FSTAB_RO) &&					\
324 	    strcmp(type, FSTAB_RW) && strcmp(type, FSTAB_RQ))
325 
326 	if ((init_flags & MNT_UPDATE) && (ro == 0))
327 		options = catopt(options, "noro");
328 
329 	rval = 0;
330 	switch (argc) {
331 	case 0:
332 		if ((mntsize = getmntinfo(&mntbuf, MNT_NOWAIT)) == 0)
333 			err(1, "getmntinfo");
334 		if (all) {
335 			while ((fs = getfsent()) != NULL) {
336 				if (BADTYPE(fs->fs_type))
337 					continue;
338 				if (checkvfsname(fs->fs_vfstype, vfslist))
339 					continue;
340 				if (hasopt(fs->fs_mntops, "noauto"))
341 					continue;
342 				if (!hasopt(fs->fs_mntops, "late") && onlylate)
343 					continue;
344 				if (hasopt(fs->fs_mntops, "late") && !late)
345 					continue;
346 				if (hasopt(fs->fs_mntops, "failok"))
347 					failok = 1;
348 				else
349 					failok = 0;
350 				if (!(init_flags & MNT_UPDATE) &&
351 				    ismounted(fs, mntbuf, mntsize))
352 					continue;
353 				options = update_options(options, fs->fs_mntops,
354 				    mntbuf->f_flags);
355 				if (mountfs(fs->fs_vfstype, fs->fs_spec,
356 				    fs->fs_file, init_flags, options,
357 				    fs->fs_mntops) && !failok)
358 					rval = 1;
359 			}
360 		} else if (fstab_style) {
361 			for (i = 0; i < mntsize; i++) {
362 				if (checkvfsname(mntbuf[i].f_fstypename, vfslist))
363 					continue;
364 				putfsent(&mntbuf[i]);
365 			}
366 		} else {
367 			for (i = 0; i < mntsize; i++) {
368 				if (checkvfsname(mntbuf[i].f_fstypename,
369 				    vfslist))
370 					continue;
371 				if (!verbose &&
372 				    (mntbuf[i].f_flags & MNT_IGNORE) != 0)
373 					continue;
374 				prmount(&mntbuf[i]);
375 			}
376 		}
377 		exit(rval);
378 	case 1:
379 		if (vfslist != NULL)
380 			usage();
381 
382 		rmslashes(*argv, *argv);
383 		if (init_flags & MNT_UPDATE) {
384 			mntfromname = NULL;
385 			have_fstab = 0;
386 			if ((mntbuf = getmntpt(*argv)) == NULL)
387 				errx(1, "not currently mounted %s", *argv);
388 			/*
389 			 * Only get the mntflags from fstab if both mntpoint
390 			 * and mntspec are identical. Also handle the special
391 			 * case where just '/' is mounted and 'spec' is not
392 			 * identical with the one from fstab ('/dev' is missing
393 			 * in the spec-string at boot-time).
394 			 */
395 			if ((fs = getfsfile(mntbuf->f_mntonname)) != NULL) {
396 				if (strcmp(fs->fs_spec,
397 				    mntbuf->f_mntfromname) == 0 &&
398 				    strcmp(fs->fs_file,
399 				    mntbuf->f_mntonname) == 0) {
400 					have_fstab = 1;
401 					mntfromname = mntbuf->f_mntfromname;
402 				} else if (argv[0][0] == '/' &&
403 				    argv[0][1] == '\0' &&
404 				    strcmp(fs->fs_vfstype,
405 				    mntbuf->f_fstypename) == 0) {
406 					fs = getfsfile("/");
407 					have_fstab = 1;
408 					mntfromname = fs->fs_spec;
409 				}
410 			}
411 			if (have_fstab) {
412 				options = update_options(options, fs->fs_mntops,
413 				    mntbuf->f_flags);
414 			} else {
415 				mntfromname = mntbuf->f_mntfromname;
416 				options = update_options(options, NULL,
417 				    mntbuf->f_flags);
418 			}
419 			rval = mountfs(mntbuf->f_fstypename, mntfromname,
420 			    mntbuf->f_mntonname, init_flags, options, 0);
421 			break;
422 		}
423 		if ((fs = getfsfile(*argv)) == NULL &&
424 		    (fs = getfsspec(*argv)) == NULL)
425 			errx(1, "%s: unknown special file or file system",
426 			    *argv);
427 		if (BADTYPE(fs->fs_type))
428 			errx(1, "%s has unknown file system type",
429 			    *argv);
430 		rval = mountfs(fs->fs_vfstype, fs->fs_spec, fs->fs_file,
431 		    init_flags, options, fs->fs_mntops);
432 		break;
433 	case 2:
434 		/*
435 		 * If -t flag has not been specified, the path cannot be
436 		 * found, spec contains either a ':' or a '@', then assume
437 		 * that an NFS file system is being specified ala Sun.
438 		 * Check if the hostname contains only allowed characters
439 		 * to reduce false positives.  IPv6 addresses containing
440 		 * ':' will be correctly parsed only if the separator is '@'.
441 		 * The definition of a valid hostname is taken from RFC 1034.
442 		 */
443 		if (vfslist == NULL && ((ep = strchr(argv[0], '@')) != NULL ||
444 		    (ep = strchr(argv[0], ':')) != NULL)) {
445 			if (*ep == '@') {
446 				cp = ep + 1;
447 				ep = cp + strlen(cp);
448 			} else
449 				cp = argv[0];
450 			while (cp != ep) {
451 				if (!isdigit(*cp) && !isalpha(*cp) &&
452 				    *cp != '.' && *cp != '-' && *cp != ':')
453 					break;
454 				cp++;
455 			}
456 			if (cp == ep)
457 				vfstype = "nfs";
458 		}
459 		rval = mountfs(vfstype,
460 		    argv[0], argv[1], init_flags, options, NULL);
461 		break;
462 	default:
463 		usage();
464 		/* NOTREACHED */
465 	}
466 
467 	/*
468 	 * If the mount was successfully, and done by root, tell mountd the
469 	 * good news.
470 	 */
471 	if (rval == 0 && getuid() == 0)
472 		restart_mountd();
473 
474 	exit(rval);
475 }
476 
477 int
478 ismounted(struct fstab *fs, struct statfs *mntbuf, int mntsize)
479 {
480 	char realfsfile[PATH_MAX];
481 	int i;
482 
483 	if (fs->fs_file[0] == '/' && fs->fs_file[1] == '\0')
484 		/* the root file system can always be remounted */
485 		return (0);
486 
487 	/* The user may have specified a symlink in fstab, resolve the path */
488 	if (realpath(fs->fs_file, realfsfile) == NULL) {
489 		/* Cannot resolve the path, use original one */
490 		strlcpy(realfsfile, fs->fs_file, sizeof(realfsfile));
491 	}
492 
493 	/*
494 	 * Consider the filesystem to be mounted if:
495 	 * It has the same mountpoint as a mounted filesytem, and
496 	 * It has the same type as that same mounted filesystem, and
497 	 * It has the same device name as that same mounted filesystem, OR
498 	 *     It is a nonremountable filesystem
499 	 */
500 	for (i = mntsize - 1; i >= 0; --i)
501 		if (strcmp(realfsfile, mntbuf[i].f_mntonname) == 0 &&
502 		    strcmp(fs->fs_vfstype, mntbuf[i].f_fstypename) == 0 &&
503 		    (!isremountable(fs->fs_vfstype) ||
504 		     (strcmp(fs->fs_spec, mntbuf[i].f_mntfromname) == 0)))
505 			return (1);
506 	return (0);
507 }
508 
509 int
510 isremountable(const char *vfsname)
511 {
512 	const char **cp;
513 
514 	for (cp = remountable_fs_names; *cp; cp++)
515 		if (strcmp(*cp, vfsname) == 0)
516 			return (1);
517 	return (0);
518 }
519 
520 int
521 hasopt(const char *mntopts, const char *option)
522 {
523 	int negative, found;
524 	char *opt, *optbuf;
525 
526 	if (option[0] == 'n' && option[1] == 'o') {
527 		negative = 1;
528 		option += 2;
529 	} else
530 		negative = 0;
531 	optbuf = strdup(mntopts);
532 	found = 0;
533 	for (opt = optbuf; (opt = strtok(opt, ",")) != NULL; opt = NULL) {
534 		if (opt[0] == 'n' && opt[1] == 'o') {
535 			if (!strcasecmp(opt + 2, option))
536 				found = negative;
537 		} else if (!strcasecmp(opt, option))
538 			found = !negative;
539 	}
540 	free(optbuf);
541 	return (found);
542 }
543 
544 static void
545 append_arg(struct cpa *sa, char *arg)
546 {
547 	if (sa->c + 1 == sa->sz) {
548 		sa->sz = sa->sz == 0 ? 8 : sa->sz * 2;
549 		sa->a = realloc(sa->a, sizeof(*sa->a) * sa->sz);
550 		if (sa->a == NULL)
551 			errx(1, "realloc failed");
552 	}
553 	sa->a[++sa->c] = arg;
554 }
555 
556 int
557 mountfs(const char *vfstype, const char *spec, const char *name, int flags,
558 	const char *options, const char *mntopts)
559 {
560 	struct statfs sf;
561 	int i, ret;
562 	char *optbuf, execname[PATH_MAX], mntpath[PATH_MAX];
563 	static struct cpa mnt_argv;
564 
565 	/* resolve the mountpoint with realpath(3) */
566 	if (checkpath(name, mntpath) != 0) {
567 		warn("%s", mntpath);
568 		return (1);
569 	}
570 	name = mntpath;
571 
572 	if (mntopts == NULL)
573 		mntopts = "";
574 	optbuf = catopt(strdup(mntopts), options);
575 
576 	if (strcmp(name, "/") == 0)
577 		flags |= MNT_UPDATE;
578 	if (flags & MNT_FORCE)
579 		optbuf = catopt(optbuf, "force");
580 	if (flags & MNT_RDONLY)
581 		optbuf = catopt(optbuf, "ro");
582 	/*
583 	 * XXX
584 	 * The mount_mfs (newfs) command uses -o to select the
585 	 * optimization mode.  We don't pass the default "-o rw"
586 	 * for that reason.
587 	 */
588 	if (flags & MNT_UPDATE)
589 		optbuf = catopt(optbuf, "update");
590 
591 	/* Compatibility glue. */
592 	if (strcmp(vfstype, "msdos") == 0) {
593 		warnx(
594 		    "Using \"-t msdosfs\", since \"-t msdos\" is deprecated.");
595 		vfstype = "msdosfs";
596 	}
597 
598 	/* Construct the name of the appropriate mount command */
599 	(void)snprintf(execname, sizeof(execname), "mount_%s", vfstype);
600 
601 	mnt_argv.c = -1;
602 	append_arg(&mnt_argv, execname);
603 	mangle(optbuf, &mnt_argv);
604 	if (mountprog != NULL)
605 		strlcpy(execname, mountprog, sizeof(execname));
606 
607 	append_arg(&mnt_argv, strdup(spec));
608 	append_arg(&mnt_argv, strdup(name));
609 	append_arg(&mnt_argv, NULL);
610 
611 	if (debug) {
612 		if (use_mountprog(vfstype))
613 			printf("exec: %s", execname);
614 		else
615 			printf("mount -t %s", vfstype);
616 		for (i = 1; i < mnt_argv.c; i++)
617 			(void)printf(" %s", mnt_argv.a[i]);
618 		(void)printf("\n");
619 		free(optbuf);
620 		free(mountprog);
621 		mountprog = NULL;
622 		return (0);
623 	}
624 
625 	if (use_mountprog(vfstype)) {
626 		ret = exec_mountprog(name, execname, mnt_argv.a);
627 	} else {
628 		ret = mount_fs(vfstype, mnt_argv.c, mnt_argv.a);
629 	}
630 
631 	free(optbuf);
632 	free(mountprog);
633 	mountprog = NULL;
634 
635 	if (verbose) {
636 		if (statfs(name, &sf) < 0) {
637 			warn("statfs %s", name);
638 			return (1);
639 		}
640 		if (fstab_style)
641 			putfsent(&sf);
642 		else
643 			prmount(&sf);
644 	}
645 
646 	return (ret);
647 }
648 
649 void
650 prmount(struct statfs *sfp)
651 {
652 	uint64_t flags;
653 	unsigned int i;
654 	struct opt *o;
655 	struct passwd *pw;
656 
657 	(void)printf("%s on %s (%s", sfp->f_mntfromname, sfp->f_mntonname,
658 	    sfp->f_fstypename);
659 
660 	flags = sfp->f_flags & MNT_VISFLAGMASK;
661 	for (o = optnames; flags != 0 && o->o_opt != 0; o++)
662 		if (flags & o->o_opt) {
663 			(void)printf(", %s", o->o_name);
664 			flags &= ~o->o_opt;
665 		}
666 	/*
667 	 * Inform when file system is mounted by an unprivileged user
668 	 * or privileged non-root user.
669 	 */
670 	if ((flags & MNT_USER) != 0 || sfp->f_owner != 0) {
671 		(void)printf(", mounted by ");
672 		if ((pw = getpwuid(sfp->f_owner)) != NULL)
673 			(void)printf("%s", pw->pw_name);
674 		else
675 			(void)printf("%d", sfp->f_owner);
676 	}
677 	if (verbose) {
678 		if (sfp->f_syncwrites != 0 || sfp->f_asyncwrites != 0)
679 			(void)printf(", writes: sync %ju async %ju",
680 			    (uintmax_t)sfp->f_syncwrites,
681 			    (uintmax_t)sfp->f_asyncwrites);
682 		if (sfp->f_syncreads != 0 || sfp->f_asyncreads != 0)
683 			(void)printf(", reads: sync %ju async %ju",
684 			    (uintmax_t)sfp->f_syncreads,
685 			    (uintmax_t)sfp->f_asyncreads);
686 		if (sfp->f_fsid.val[0] != 0 || sfp->f_fsid.val[1] != 0) {
687 			printf(", fsid ");
688 			for (i = 0; i < sizeof(sfp->f_fsid); i++)
689 				printf("%02x", ((u_char *)&sfp->f_fsid)[i]);
690 		}
691 	}
692 	(void)printf(")\n");
693 }
694 
695 struct statfs *
696 getmntpt(const char *name)
697 {
698 	struct statfs *mntbuf;
699 	int i, mntsize;
700 
701 	mntsize = getmntinfo(&mntbuf, MNT_NOWAIT);
702 	for (i = mntsize - 1; i >= 0; i--) {
703 		if (strcmp(mntbuf[i].f_mntfromname, name) == 0 ||
704 		    strcmp(mntbuf[i].f_mntonname, name) == 0)
705 			return (&mntbuf[i]);
706 	}
707 	return (NULL);
708 }
709 
710 char *
711 catopt(char *s0, const char *s1)
712 {
713 	char *cp;
714 
715 	if (s1 == NULL || *s1 == '\0')
716 		return (s0);
717 
718 	if (s0 && *s0) {
719 		if (asprintf(&cp, "%s,%s", s0, s1) == -1)
720 			errx(1, "asprintf failed");
721 	} else
722 		cp = strdup(s1);
723 
724 	if (s0)
725 		free(s0);
726 	return (cp);
727 }
728 
729 void
730 mangle(char *options, struct cpa *a)
731 {
732 	char *p, *s, *val;
733 
734 	for (s = options; (p = strsep(&s, ",")) != NULL;)
735 		if (*p != '\0') {
736 			if (strcmp(p, "noauto") == 0) {
737 				/*
738 				 * Do not pass noauto option to nmount().
739 				 * or external mount program.  noauto is
740 				 * only used to prevent mounting a filesystem
741 				 * when 'mount -a' is specified, and is
742 				 * not a real mount option.
743 				 */
744 				continue;
745 			} else if (strcmp(p, "late") == 0) {
746 				/*
747 				 * "late" is used to prevent certain file
748 				 * systems from being mounted before late
749 				 * in the boot cycle; for instance,
750 				 * loopback NFS mounts can't be mounted
751 				 * before mountd starts.
752 				 */
753 				continue;
754 			} else if (strcmp(p, "failok") == 0) {
755 				/*
756 				 * "failok" is used to prevent certain file
757 				 * systems from being causing the system to
758 				 * drop into single user mode in the boot
759 				 * cycle, and is not a real mount option.
760 				 */
761 				continue;
762 			} else if (strncmp(p, "mountprog", 9) == 0) {
763 				/*
764 				 * "mountprog" is used to force the use of
765 				 * userland mount programs.
766 				 */
767 				val = strchr(p, '=');
768                         	if (val != NULL) {
769                                 	++val;
770 					if (*val != '\0')
771 						mountprog = strdup(val);
772 				}
773 
774 				if (mountprog == NULL) {
775 					errx(1, "Need value for -o mountprog");
776 				}
777 				continue;
778 			} else if (strcmp(p, "userquota") == 0) {
779 				continue;
780 			} else if (strncmp(p, userquotaeq,
781 			    sizeof(userquotaeq) - 1) == 0) {
782 				continue;
783 			} else if (strcmp(p, "groupquota") == 0) {
784 				continue;
785 			} else if (strncmp(p, groupquotaeq,
786 			    sizeof(groupquotaeq) - 1) == 0) {
787 				continue;
788 			} else if (*p == '-') {
789 				append_arg(a, p);
790 				p = strchr(p, '=');
791 				if (p != NULL) {
792 					*p = '\0';
793 					append_arg(a, p + 1);
794 				}
795 			} else {
796 				append_arg(a, strdup("-o"));
797 				append_arg(a, p);
798 			}
799 		}
800 }
801 
802 
803 char *
804 update_options(char *opts, char *fstab, int curflags)
805 {
806 	char *o, *p;
807 	char *cur;
808 	char *expopt, *newopt, *tmpopt;
809 
810 	if (opts == NULL)
811 		return (strdup(""));
812 
813 	/* remove meta options from list */
814 	remopt(fstab, MOUNT_META_OPTION_FSTAB);
815 	remopt(fstab, MOUNT_META_OPTION_CURRENT);
816 	cur = flags2opts(curflags);
817 
818 	/*
819 	 * Expand all meta-options passed to us first.
820 	 */
821 	expopt = NULL;
822 	for (p = opts; (o = strsep(&p, ",")) != NULL;) {
823 		if (strcmp(MOUNT_META_OPTION_FSTAB, o) == 0)
824 			expopt = catopt(expopt, fstab);
825 		else if (strcmp(MOUNT_META_OPTION_CURRENT, o) == 0)
826 			expopt = catopt(expopt, cur);
827 		else
828 			expopt = catopt(expopt, o);
829 	}
830 	free(cur);
831 	free(opts);
832 
833 	/*
834 	 * Remove previous contradictory arguments. Given option "foo" we
835 	 * remove all the "nofoo" options. Given "nofoo" we remove "nonofoo"
836 	 * and "foo" - so we can deal with possible options like "notice".
837 	 */
838 	newopt = NULL;
839 	for (p = expopt; (o = strsep(&p, ",")) != NULL;) {
840 		if ((tmpopt = malloc( strlen(o) + 2 + 1 )) == NULL)
841 			errx(1, "malloc failed");
842 
843 		strcpy(tmpopt, "no");
844 		strcat(tmpopt, o);
845 		remopt(newopt, tmpopt);
846 		free(tmpopt);
847 
848 		if (strncmp("no", o, 2) == 0)
849 			remopt(newopt, o+2);
850 
851 		newopt = catopt(newopt, o);
852 	}
853 	free(expopt);
854 
855 	return (newopt);
856 }
857 
858 void
859 remopt(char *string, const char *opt)
860 {
861 	char *o, *p, *r;
862 
863 	if (string == NULL || *string == '\0' || opt == NULL || *opt == '\0')
864 		return;
865 
866 	r = string;
867 
868 	for (p = string; (o = strsep(&p, ",")) != NULL;) {
869 		if (strcmp(opt, o) != 0) {
870 			if (*r == ',' && *o != '\0')
871 				r++;
872 			while ((*r++ = *o++) != '\0')
873 			    ;
874 			*--r = ',';
875 		}
876 	}
877 	*r = '\0';
878 }
879 
880 void
881 usage(void)
882 {
883 
884 	(void)fprintf(stderr, "%s\n%s\n%s\n",
885 "usage: mount [-adflpruvw] [-F fstab] [-o options] [-t ufs | external_type]",
886 "       mount [-dfpruvw] special | node",
887 "       mount [-dfpruvw] [-o options] [-t ufs | external_type] special node");
888 	exit(1);
889 }
890 
891 void
892 putfsent(struct statfs *ent)
893 {
894 	struct fstab *fst;
895 	char *opts, *rw;
896 	int l;
897 
898 	opts = NULL;
899 	/* flags2opts() doesn't return the "rw" option. */
900 	if ((ent->f_flags & MNT_RDONLY) != 0)
901 		rw = NULL;
902 	else
903 		rw = catopt(NULL, "rw");
904 
905 	opts = flags2opts(ent->f_flags);
906 	opts = catopt(rw, opts);
907 
908 	if (strncmp(ent->f_mntfromname, "<below>", 7) == 0 ||
909 	    strncmp(ent->f_mntfromname, "<above>", 7) == 0) {
910 		strlcpy(ent->f_mntfromname,
911 		    (strnstr(ent->f_mntfromname, ":", 8) +1),
912 		    sizeof(ent->f_mntfromname));
913 	}
914 
915 	l = strlen(ent->f_mntfromname);
916 	printf("%s%s%s%s", ent->f_mntfromname,
917 	    l < 8 ? "\t" : "",
918 	    l < 16 ? "\t" : "",
919 	    l < 24 ? "\t" : " ");
920 	l = strlen(ent->f_mntonname);
921 	printf("%s%s%s%s", ent->f_mntonname,
922 	    l < 8 ? "\t" : "",
923 	    l < 16 ? "\t" : "",
924 	    l < 24 ? "\t" : " ");
925 	printf("%s\t", ent->f_fstypename);
926 	l = strlen(opts);
927 	printf("%s%s", opts,
928 	    l < 8 ? "\t" : " ");
929 	free(opts);
930 
931 	if ((fst = getfsspec(ent->f_mntfromname)))
932 		printf("\t%u %u\n", fst->fs_freq, fst->fs_passno);
933 	else if ((fst = getfsfile(ent->f_mntonname)))
934 		printf("\t%u %u\n", fst->fs_freq, fst->fs_passno);
935 	else if (strcmp(ent->f_fstypename, "ufs") == 0) {
936 		if (strcmp(ent->f_mntonname, "/") == 0)
937 			printf("\t1 1\n");
938 		else
939 			printf("\t2 2\n");
940 	} else
941 		printf("\t0 0\n");
942 }
943 
944 
945 char *
946 flags2opts(int flags)
947 {
948 	char *res;
949 
950 	res = NULL;
951 
952 	if (flags & MNT_RDONLY)		res = catopt(res, "ro");
953 	if (flags & MNT_SYNCHRONOUS)	res = catopt(res, "sync");
954 	if (flags & MNT_NOEXEC)		res = catopt(res, "noexec");
955 	if (flags & MNT_NOSUID)		res = catopt(res, "nosuid");
956 	if (flags & MNT_UNION)		res = catopt(res, "union");
957 	if (flags & MNT_ASYNC)		res = catopt(res, "async");
958 	if (flags & MNT_NOATIME)	res = catopt(res, "noatime");
959 	if (flags & MNT_NOCLUSTERR)	res = catopt(res, "noclusterr");
960 	if (flags & MNT_NOCLUSTERW)	res = catopt(res, "noclusterw");
961 	if (flags & MNT_NOSYMFOLLOW)	res = catopt(res, "nosymfollow");
962 	if (flags & MNT_SUIDDIR)	res = catopt(res, "suiddir");
963 	if (flags & MNT_MULTILABEL)	res = catopt(res, "multilabel");
964 	if (flags & MNT_ACLS)		res = catopt(res, "acls");
965 	if (flags & MNT_NFS4ACLS)	res = catopt(res, "nfsv4acls");
966 
967 	return (res);
968 }
969