xref: /freebsd/sbin/mount/mount.c (revision a0b9e2e854027e6ff61fb075a1309dbc71c42b54)
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 #define _WANT_MNTOPTNAMES
46 #include <sys/mount.h>
47 #include <sys/stat.h>
48 #include <sys/wait.h>
49 
50 #include <ctype.h>
51 #include <err.h>
52 #include <errno.h>
53 #include <fstab.h>
54 #include <paths.h>
55 #include <pwd.h>
56 #include <signal.h>
57 #include <stdint.h>
58 #include <stdio.h>
59 #include <stdlib.h>
60 #include <string.h>
61 #include <unistd.h>
62 #include <libutil.h>
63 
64 #include "extern.h"
65 #include "mntopts.h"
66 #include "pathnames.h"
67 
68 /* `meta' options */
69 #define MOUNT_META_OPTION_FSTAB		"fstab"
70 #define MOUNT_META_OPTION_CURRENT	"current"
71 
72 static int debug, fstab_style, verbose;
73 
74 struct cpa {
75 	char	**a;
76 	ssize_t	sz;
77 	int	c;
78 };
79 
80 char   *catopt(char *, const char *);
81 struct statfs *getmntpt(const char *);
82 int	hasopt(const char *, const char *);
83 int	ismounted(struct fstab *, struct statfs *, int);
84 int	isremountable(const char *);
85 void	mangle(char *, struct cpa *);
86 char   *update_options(char *, char *, int);
87 int	mountfs(const char *, const char *, const char *,
88 			int, const char *, const char *);
89 void	remopt(char *, const char *);
90 void	prmount(struct statfs *);
91 void	putfsent(struct statfs *);
92 void	usage(void);
93 char   *flags2opts(int);
94 
95 /* Map from mount options to printable formats. */
96 static struct mntoptnames optnames[] = {
97 	MNTOPT_NAMES
98 };
99 
100 /*
101  * List of VFS types that can be remounted without becoming mounted on top
102  * of each other.
103  * XXX Is this list correct?
104  */
105 static const char *
106 remountable_fs_names[] = {
107 	"ufs", "ffs", "ext2fs",
108 	0
109 };
110 
111 static const char userquotaeq[] = "userquota=";
112 static const char groupquotaeq[] = "groupquota=";
113 
114 static char *mountprog = NULL;
115 
116 static int
117 use_mountprog(const char *vfstype)
118 {
119 	/* XXX: We need to get away from implementing external mount
120 	 *      programs for every filesystem, and move towards having
121 	 *	each filesystem properly implement the nmount() system call.
122 	 */
123 	unsigned int i;
124 	const char *fs[] = {
125 	"cd9660", "mfs", "msdosfs", "nfs",
126 	"nullfs", "smbfs", "udf", "unionfs",
127 	NULL
128 	};
129 
130 	if (mountprog != NULL)
131 		return (1);
132 
133 	for (i = 0; fs[i] != NULL; ++i) {
134 		if (strcmp(vfstype, fs[i]) == 0)
135 			return (1);
136 	}
137 
138 	return (0);
139 }
140 
141 static int
142 exec_mountprog(const char *name, const char *execname, char *const argv[])
143 {
144 	pid_t pid;
145 	int status;
146 
147 	switch (pid = fork()) {
148 	case -1:				/* Error. */
149 		warn("fork");
150 		exit (1);
151 	case 0:					/* Child. */
152 		/* Go find an executable. */
153 		execvP(execname, _PATH_SYSPATH, argv);
154 		if (errno == ENOENT) {
155 			warn("exec %s not found", execname);
156 			if (execname[0] != '/') {
157 				warnx("in path: %s", _PATH_SYSPATH);
158 			}
159 		}
160 		exit(1);
161 	default:				/* Parent. */
162 		if (waitpid(pid, &status, 0) < 0) {
163 			warn("waitpid");
164 			return (1);
165 		}
166 
167 		if (WIFEXITED(status)) {
168 			if (WEXITSTATUS(status) != 0)
169 				return (WEXITSTATUS(status));
170 		} else if (WIFSIGNALED(status)) {
171 			warnx("%s: %s", name, sys_siglist[WTERMSIG(status)]);
172 			return (1);
173 		}
174 		break;
175 	}
176 
177 	return (0);
178 }
179 
180 static int
181 specified_ro(const char *arg)
182 {
183 	char *optbuf, *opt;
184 	int ret = 0;
185 
186 	optbuf = strdup(arg);
187 	if (optbuf == NULL)
188 		 err(1, NULL);
189 
190 	for (opt = optbuf; (opt = strtok(opt, ",")) != NULL; opt = NULL) {
191 		if (strcmp(opt, "ro") == 0) {
192 			ret = 1;
193 			break;
194 		}
195 	}
196 	free(optbuf);
197 	return (ret);
198 }
199 
200 static void
201 restart_mountd(void)
202 {
203 	struct pidfh *pfh;
204 	pid_t mountdpid;
205 
206 	mountdpid = 0;
207 	pfh = pidfile_open(_PATH_MOUNTDPID, 0600, &mountdpid);
208 	if (pfh != NULL) {
209 		/* Mountd is not running. */
210 		pidfile_remove(pfh);
211 		return;
212 	}
213 	if (errno != EEXIST) {
214 		/* Cannot open pidfile for some reason. */
215 		return;
216 	}
217 
218 	/*
219 	 * Refuse to send broadcast or group signals, this has
220 	 * happened due to the bugs in pidfile(3).
221 	 */
222 	if (mountdpid <= 0) {
223 		warnx("mountd pid %d, refusing to send SIGHUP", mountdpid);
224 		return;
225 	}
226 
227 	/* We have mountd(8) PID in mountdpid varible, let's signal it. */
228 	if (kill(mountdpid, SIGHUP) == -1)
229 		err(1, "signal mountd");
230 }
231 
232 int
233 main(int argc, char *argv[])
234 {
235 	const char *mntfromname, **vfslist, *vfstype;
236 	struct fstab *fs;
237 	struct statfs *mntbuf;
238 	int all, ch, i, init_flags, late, failok, mntsize, rval, have_fstab, ro;
239 	int onlylate;
240 	char *cp, *ep, *options;
241 
242 	all = init_flags = late = onlylate = 0;
243 	ro = 0;
244 	options = NULL;
245 	vfslist = NULL;
246 	vfstype = "ufs";
247 	while ((ch = getopt(argc, argv, "adF:fLlno:prt:uvw")) != -1)
248 		switch (ch) {
249 		case 'a':
250 			all = 1;
251 			break;
252 		case 'd':
253 			debug = 1;
254 			break;
255 		case 'F':
256 			setfstab(optarg);
257 			break;
258 		case 'f':
259 			init_flags |= MNT_FORCE;
260 			break;
261 		case 'L':
262 			onlylate = 1;
263 			late = 1;
264 			break;
265 		case 'l':
266 			late = 1;
267 			break;
268 		case 'n':
269 			/* For compatibility with the Linux version of mount. */
270 			break;
271 		case 'o':
272 			if (*optarg) {
273 				options = catopt(options, optarg);
274 				if (specified_ro(optarg))
275 					ro = 1;
276 			}
277 			break;
278 		case 'p':
279 			fstab_style = 1;
280 			verbose = 1;
281 			break;
282 		case 'r':
283 			options = catopt(options, "ro");
284 			ro = 1;
285 			break;
286 		case 't':
287 			if (vfslist != NULL)
288 				errx(1, "only one -t option may be specified");
289 			vfslist = makevfslist(optarg);
290 			vfstype = optarg;
291 			break;
292 		case 'u':
293 			init_flags |= MNT_UPDATE;
294 			break;
295 		case 'v':
296 			verbose = 1;
297 			break;
298 		case 'w':
299 			options = catopt(options, "noro");
300 			break;
301 		case '?':
302 		default:
303 			usage();
304 			/* NOTREACHED */
305 		}
306 	argc -= optind;
307 	argv += optind;
308 
309 #define	BADTYPE(type)							\
310 	(strcmp(type, FSTAB_RO) &&					\
311 	    strcmp(type, FSTAB_RW) && strcmp(type, FSTAB_RQ))
312 
313 	if ((init_flags & MNT_UPDATE) && (ro == 0))
314 		options = catopt(options, "noro");
315 
316 	rval = 0;
317 	switch (argc) {
318 	case 0:
319 		if ((mntsize = getmntinfo(&mntbuf,
320 		     verbose ? MNT_WAIT : MNT_NOWAIT)) == 0)
321 			err(1, "getmntinfo");
322 		if (all) {
323 			while ((fs = getfsent()) != NULL) {
324 				if (BADTYPE(fs->fs_type))
325 					continue;
326 				if (checkvfsname(fs->fs_vfstype, vfslist))
327 					continue;
328 				if (hasopt(fs->fs_mntops, "noauto"))
329 					continue;
330 				if (!hasopt(fs->fs_mntops, "late") && onlylate)
331 					continue;
332 				if (hasopt(fs->fs_mntops, "late") && !late)
333 					continue;
334 				if (hasopt(fs->fs_mntops, "failok"))
335 					failok = 1;
336 				else
337 					failok = 0;
338 				if (!(init_flags & MNT_UPDATE) &&
339 				    !hasopt(fs->fs_mntops, "update") &&
340 				    ismounted(fs, mntbuf, mntsize))
341 					continue;
342 				options = update_options(options, fs->fs_mntops,
343 				    mntbuf->f_flags);
344 				if (mountfs(fs->fs_vfstype, fs->fs_spec,
345 				    fs->fs_file, init_flags, options,
346 				    fs->fs_mntops) && !failok)
347 					rval = 1;
348 			}
349 		} else if (fstab_style) {
350 			for (i = 0; i < mntsize; i++) {
351 				if (checkvfsname(mntbuf[i].f_fstypename, vfslist))
352 					continue;
353 				putfsent(&mntbuf[i]);
354 			}
355 		} else {
356 			for (i = 0; i < mntsize; i++) {
357 				if (checkvfsname(mntbuf[i].f_fstypename,
358 				    vfslist))
359 					continue;
360 				if (!verbose &&
361 				    (mntbuf[i].f_flags & MNT_IGNORE) != 0)
362 					continue;
363 				prmount(&mntbuf[i]);
364 			}
365 		}
366 		exit(rval);
367 	case 1:
368 		if (vfslist != NULL)
369 			usage();
370 
371 		rmslashes(*argv, *argv);
372 		if (init_flags & MNT_UPDATE) {
373 			mntfromname = NULL;
374 			have_fstab = 0;
375 			if ((mntbuf = getmntpt(*argv)) == NULL)
376 				errx(1, "not currently mounted %s", *argv);
377 			/*
378 			 * Only get the mntflags from fstab if both mntpoint
379 			 * and mntspec are identical. Also handle the special
380 			 * case where just '/' is mounted and 'spec' is not
381 			 * identical with the one from fstab ('/dev' is missing
382 			 * in the spec-string at boot-time).
383 			 */
384 			if ((fs = getfsfile(mntbuf->f_mntonname)) != NULL) {
385 				if (strcmp(fs->fs_spec,
386 				    mntbuf->f_mntfromname) == 0 &&
387 				    strcmp(fs->fs_file,
388 				    mntbuf->f_mntonname) == 0) {
389 					have_fstab = 1;
390 					mntfromname = mntbuf->f_mntfromname;
391 				} else if (argv[0][0] == '/' &&
392 				    argv[0][1] == '\0' &&
393 				    strcmp(fs->fs_vfstype,
394 				    mntbuf->f_fstypename) == 0) {
395 					fs = getfsfile("/");
396 					have_fstab = 1;
397 					mntfromname = fs->fs_spec;
398 				}
399 			}
400 			if (have_fstab) {
401 				options = update_options(options, fs->fs_mntops,
402 				    mntbuf->f_flags);
403 			} else {
404 				mntfromname = mntbuf->f_mntfromname;
405 				options = update_options(options, NULL,
406 				    mntbuf->f_flags);
407 			}
408 			rval = mountfs(mntbuf->f_fstypename, mntfromname,
409 			    mntbuf->f_mntonname, init_flags, options, 0);
410 			break;
411 		}
412 		if ((fs = getfsfile(*argv)) == NULL &&
413 		    (fs = getfsspec(*argv)) == NULL)
414 			errx(1, "%s: unknown special file or file system",
415 			    *argv);
416 		if (BADTYPE(fs->fs_type))
417 			errx(1, "%s has unknown file system type",
418 			    *argv);
419 		rval = mountfs(fs->fs_vfstype, fs->fs_spec, fs->fs_file,
420 		    init_flags, options, fs->fs_mntops);
421 		break;
422 	case 2:
423 		/*
424 		 * If -t flag has not been specified, the path cannot be
425 		 * found, spec contains either a ':' or a '@', then assume
426 		 * that an NFS file system is being specified ala Sun.
427 		 * Check if the hostname contains only allowed characters
428 		 * to reduce false positives.  IPv6 addresses containing
429 		 * ':' will be correctly parsed only if the separator is '@'.
430 		 * The definition of a valid hostname is taken from RFC 1034.
431 		 */
432 		if (vfslist == NULL && ((ep = strchr(argv[0], '@')) != NULL ||
433 		    (ep = strchr(argv[0], ':')) != NULL)) {
434 			if (*ep == '@') {
435 				cp = ep + 1;
436 				ep = cp + strlen(cp);
437 			} else
438 				cp = argv[0];
439 			while (cp != ep) {
440 				if (!isdigit(*cp) && !isalpha(*cp) &&
441 				    *cp != '.' && *cp != '-' && *cp != ':')
442 					break;
443 				cp++;
444 			}
445 			if (cp == ep)
446 				vfstype = "nfs";
447 		}
448 		rval = mountfs(vfstype,
449 		    argv[0], argv[1], init_flags, options, NULL);
450 		break;
451 	default:
452 		usage();
453 		/* NOTREACHED */
454 	}
455 
456 	/*
457 	 * If the mount was successfully, and done by root, tell mountd the
458 	 * good news.
459 	 */
460 	if (rval == 0 && getuid() == 0)
461 		restart_mountd();
462 
463 	exit(rval);
464 }
465 
466 int
467 ismounted(struct fstab *fs, struct statfs *mntbuf, int mntsize)
468 {
469 	char realfsfile[PATH_MAX];
470 	int i;
471 
472 	if (fs->fs_file[0] == '/' && fs->fs_file[1] == '\0')
473 		/* the root file system can always be remounted */
474 		return (0);
475 
476 	/* The user may have specified a symlink in fstab, resolve the path */
477 	if (realpath(fs->fs_file, realfsfile) == NULL) {
478 		/* Cannot resolve the path, use original one */
479 		strlcpy(realfsfile, fs->fs_file, sizeof(realfsfile));
480 	}
481 
482 	/*
483 	 * Consider the filesystem to be mounted if:
484 	 * It has the same mountpoint as a mounted filesytem, and
485 	 * It has the same type as that same mounted filesystem, and
486 	 * It has the same device name as that same mounted filesystem, OR
487 	 *     It is a nonremountable filesystem
488 	 */
489 	for (i = mntsize - 1; i >= 0; --i)
490 		if (strcmp(realfsfile, mntbuf[i].f_mntonname) == 0 &&
491 		    strcmp(fs->fs_vfstype, mntbuf[i].f_fstypename) == 0 &&
492 		    (!isremountable(fs->fs_vfstype) ||
493 		     (strcmp(fs->fs_spec, mntbuf[i].f_mntfromname) == 0)))
494 			return (1);
495 	return (0);
496 }
497 
498 int
499 isremountable(const char *vfsname)
500 {
501 	const char **cp;
502 
503 	for (cp = remountable_fs_names; *cp; cp++)
504 		if (strcmp(*cp, vfsname) == 0)
505 			return (1);
506 	return (0);
507 }
508 
509 int
510 hasopt(const char *mntopts, const char *option)
511 {
512 	int negative, found;
513 	char *opt, *optbuf;
514 
515 	if (option[0] == 'n' && option[1] == 'o') {
516 		negative = 1;
517 		option += 2;
518 	} else
519 		negative = 0;
520 	optbuf = strdup(mntopts);
521 	found = 0;
522 	for (opt = optbuf; (opt = strtok(opt, ",")) != NULL; opt = NULL) {
523 		if (opt[0] == 'n' && opt[1] == 'o') {
524 			if (!strcasecmp(opt + 2, option))
525 				found = negative;
526 		} else if (!strcasecmp(opt, option))
527 			found = !negative;
528 	}
529 	free(optbuf);
530 	return (found);
531 }
532 
533 static void
534 append_arg(struct cpa *sa, char *arg)
535 {
536 	if (sa->c + 1 == sa->sz) {
537 		sa->sz = sa->sz == 0 ? 8 : sa->sz * 2;
538 		sa->a = realloc(sa->a, sizeof(*sa->a) * sa->sz);
539 		if (sa->a == NULL)
540 			errx(1, "realloc failed");
541 	}
542 	sa->a[++sa->c] = arg;
543 }
544 
545 int
546 mountfs(const char *vfstype, const char *spec, const char *name, int flags,
547 	const char *options, const char *mntopts)
548 {
549 	struct statfs sf;
550 	int i, ret;
551 	char *optbuf, execname[PATH_MAX], mntpath[PATH_MAX];
552 	static struct cpa mnt_argv;
553 
554 	/* resolve the mountpoint with realpath(3) */
555 	if (checkpath(name, mntpath) != 0) {
556 		warn("%s", mntpath);
557 		return (1);
558 	}
559 	name = mntpath;
560 
561 	if (mntopts == NULL)
562 		mntopts = "";
563 	optbuf = catopt(strdup(mntopts), options);
564 
565 	if (strcmp(name, "/") == 0)
566 		flags |= MNT_UPDATE;
567 	if (flags & MNT_FORCE)
568 		optbuf = catopt(optbuf, "force");
569 	if (flags & MNT_RDONLY)
570 		optbuf = catopt(optbuf, "ro");
571 	/*
572 	 * XXX
573 	 * The mount_mfs (newfs) command uses -o to select the
574 	 * optimization mode.  We don't pass the default "-o rw"
575 	 * for that reason.
576 	 */
577 	if (flags & MNT_UPDATE)
578 		optbuf = catopt(optbuf, "update");
579 
580 	/* Compatibility glue. */
581 	if (strcmp(vfstype, "msdos") == 0)
582 		vfstype = "msdosfs";
583 
584 	/* Construct the name of the appropriate mount command */
585 	(void)snprintf(execname, sizeof(execname), "mount_%s", vfstype);
586 
587 	mnt_argv.c = -1;
588 	append_arg(&mnt_argv, execname);
589 	mangle(optbuf, &mnt_argv);
590 	if (mountprog != NULL)
591 		strlcpy(execname, mountprog, sizeof(execname));
592 
593 	append_arg(&mnt_argv, strdup(spec));
594 	append_arg(&mnt_argv, strdup(name));
595 	append_arg(&mnt_argv, NULL);
596 
597 	if (debug) {
598 		if (use_mountprog(vfstype))
599 			printf("exec: %s", execname);
600 		else
601 			printf("mount -t %s", vfstype);
602 		for (i = 1; i < mnt_argv.c; i++)
603 			(void)printf(" %s", mnt_argv.a[i]);
604 		(void)printf("\n");
605 		free(optbuf);
606 		free(mountprog);
607 		mountprog = NULL;
608 		return (0);
609 	}
610 
611 	if (use_mountprog(vfstype)) {
612 		ret = exec_mountprog(name, execname, mnt_argv.a);
613 	} else {
614 		ret = mount_fs(vfstype, mnt_argv.c, mnt_argv.a);
615 	}
616 
617 	free(optbuf);
618 	free(mountprog);
619 	mountprog = NULL;
620 
621 	if (verbose) {
622 		if (statfs(name, &sf) < 0) {
623 			warn("statfs %s", name);
624 			return (1);
625 		}
626 		if (fstab_style)
627 			putfsent(&sf);
628 		else
629 			prmount(&sf);
630 	}
631 
632 	return (ret);
633 }
634 
635 void
636 prmount(struct statfs *sfp)
637 {
638 	uint64_t flags;
639 	unsigned int i;
640 	struct mntoptnames *o;
641 	struct passwd *pw;
642 
643 	(void)printf("%s on %s (%s", sfp->f_mntfromname, sfp->f_mntonname,
644 	    sfp->f_fstypename);
645 
646 	flags = sfp->f_flags & MNT_VISFLAGMASK;
647 	for (o = optnames; flags != 0 && o->o_opt != 0; o++)
648 		if (flags & o->o_opt) {
649 			(void)printf(", %s", o->o_name);
650 			flags &= ~o->o_opt;
651 		}
652 	/*
653 	 * Inform when file system is mounted by an unprivileged user
654 	 * or privileged non-root user.
655 	 */
656 	if ((flags & MNT_USER) != 0 || sfp->f_owner != 0) {
657 		(void)printf(", mounted by ");
658 		if ((pw = getpwuid(sfp->f_owner)) != NULL)
659 			(void)printf("%s", pw->pw_name);
660 		else
661 			(void)printf("%d", sfp->f_owner);
662 	}
663 	if (verbose) {
664 		if (sfp->f_syncwrites != 0 || sfp->f_asyncwrites != 0)
665 			(void)printf(", writes: sync %ju async %ju",
666 			    (uintmax_t)sfp->f_syncwrites,
667 			    (uintmax_t)sfp->f_asyncwrites);
668 		if (sfp->f_syncreads != 0 || sfp->f_asyncreads != 0)
669 			(void)printf(", reads: sync %ju async %ju",
670 			    (uintmax_t)sfp->f_syncreads,
671 			    (uintmax_t)sfp->f_asyncreads);
672 		if (sfp->f_fsid.val[0] != 0 || sfp->f_fsid.val[1] != 0) {
673 			(void)printf(", fsid ");
674 			for (i = 0; i < sizeof(sfp->f_fsid); i++)
675 				(void)printf("%02x", ((u_char *)&sfp->f_fsid)[i]);
676 		}
677 	}
678 	(void)printf(")\n");
679 }
680 
681 struct statfs *
682 getmntpt(const char *name)
683 {
684 	struct statfs *mntbuf;
685 	int i, mntsize;
686 
687 	mntsize = getmntinfo(&mntbuf, MNT_NOWAIT);
688 	for (i = mntsize - 1; i >= 0; i--) {
689 		if (strcmp(mntbuf[i].f_mntfromname, name) == 0 ||
690 		    strcmp(mntbuf[i].f_mntonname, name) == 0)
691 			return (&mntbuf[i]);
692 	}
693 	return (NULL);
694 }
695 
696 char *
697 catopt(char *s0, const char *s1)
698 {
699 	char *cp;
700 
701 	if (s1 == NULL || *s1 == '\0')
702 		return (s0);
703 
704 	if (s0 && *s0) {
705 		if (asprintf(&cp, "%s,%s", s0, s1) == -1)
706 			errx(1, "asprintf failed");
707 	} else
708 		cp = strdup(s1);
709 
710 	if (s0)
711 		free(s0);
712 	return (cp);
713 }
714 
715 void
716 mangle(char *options, struct cpa *a)
717 {
718 	char *p, *s, *val;
719 
720 	for (s = options; (p = strsep(&s, ",")) != NULL;)
721 		if (*p != '\0') {
722 			if (strcmp(p, "noauto") == 0) {
723 				/*
724 				 * Do not pass noauto option to nmount().
725 				 * or external mount program.  noauto is
726 				 * only used to prevent mounting a filesystem
727 				 * when 'mount -a' is specified, and is
728 				 * not a real mount option.
729 				 */
730 				continue;
731 			} else if (strcmp(p, "late") == 0) {
732 				/*
733 				 * "late" is used to prevent certain file
734 				 * systems from being mounted before late
735 				 * in the boot cycle; for instance,
736 				 * loopback NFS mounts can't be mounted
737 				 * before mountd starts.
738 				 */
739 				continue;
740 			} else if (strcmp(p, "failok") == 0) {
741 				/*
742 				 * "failok" is used to prevent certain file
743 				 * systems from being causing the system to
744 				 * drop into single user mode in the boot
745 				 * cycle, and is not a real mount option.
746 				 */
747 				continue;
748 			} else if (strncmp(p, "mountprog", 9) == 0) {
749 				/*
750 				 * "mountprog" is used to force the use of
751 				 * userland mount programs.
752 				 */
753 				val = strchr(p, '=');
754                         	if (val != NULL) {
755                                 	++val;
756 					if (*val != '\0')
757 						mountprog = strdup(val);
758 				}
759 
760 				if (mountprog == NULL) {
761 					errx(1, "Need value for -o mountprog");
762 				}
763 				continue;
764 			} else if (strcmp(p, "userquota") == 0) {
765 				continue;
766 			} else if (strncmp(p, userquotaeq,
767 			    sizeof(userquotaeq) - 1) == 0) {
768 				continue;
769 			} else if (strcmp(p, "groupquota") == 0) {
770 				continue;
771 			} else if (strncmp(p, groupquotaeq,
772 			    sizeof(groupquotaeq) - 1) == 0) {
773 				continue;
774 			} else if (*p == '-') {
775 				append_arg(a, p);
776 				p = strchr(p, '=');
777 				if (p != NULL) {
778 					*p = '\0';
779 					append_arg(a, p + 1);
780 				}
781 			} else {
782 				append_arg(a, strdup("-o"));
783 				append_arg(a, p);
784 			}
785 		}
786 }
787 
788 
789 char *
790 update_options(char *opts, char *fstab, int curflags)
791 {
792 	char *o, *p;
793 	char *cur;
794 	char *expopt, *newopt, *tmpopt;
795 
796 	if (opts == NULL)
797 		return (strdup(""));
798 
799 	/* remove meta options from list */
800 	remopt(fstab, MOUNT_META_OPTION_FSTAB);
801 	remopt(fstab, MOUNT_META_OPTION_CURRENT);
802 	cur = flags2opts(curflags);
803 
804 	/*
805 	 * Expand all meta-options passed to us first.
806 	 */
807 	expopt = NULL;
808 	for (p = opts; (o = strsep(&p, ",")) != NULL;) {
809 		if (strcmp(MOUNT_META_OPTION_FSTAB, o) == 0)
810 			expopt = catopt(expopt, fstab);
811 		else if (strcmp(MOUNT_META_OPTION_CURRENT, o) == 0)
812 			expopt = catopt(expopt, cur);
813 		else
814 			expopt = catopt(expopt, o);
815 	}
816 	free(cur);
817 	free(opts);
818 
819 	/*
820 	 * Remove previous contradictory arguments. Given option "foo" we
821 	 * remove all the "nofoo" options. Given "nofoo" we remove "nonofoo"
822 	 * and "foo" - so we can deal with possible options like "notice".
823 	 */
824 	newopt = NULL;
825 	for (p = expopt; (o = strsep(&p, ",")) != NULL;) {
826 		if ((tmpopt = malloc( strlen(o) + 2 + 1 )) == NULL)
827 			errx(1, "malloc failed");
828 
829 		strcpy(tmpopt, "no");
830 		strcat(tmpopt, o);
831 		remopt(newopt, tmpopt);
832 		free(tmpopt);
833 
834 		if (strncmp("no", o, 2) == 0)
835 			remopt(newopt, o+2);
836 
837 		newopt = catopt(newopt, o);
838 	}
839 	free(expopt);
840 
841 	return (newopt);
842 }
843 
844 void
845 remopt(char *string, const char *opt)
846 {
847 	char *o, *p, *r;
848 
849 	if (string == NULL || *string == '\0' || opt == NULL || *opt == '\0')
850 		return;
851 
852 	r = string;
853 
854 	for (p = string; (o = strsep(&p, ",")) != NULL;) {
855 		if (strcmp(opt, o) != 0) {
856 			if (*r == ',' && *o != '\0')
857 				r++;
858 			while ((*r++ = *o++) != '\0')
859 			    ;
860 			*--r = ',';
861 		}
862 	}
863 	*r = '\0';
864 }
865 
866 void
867 usage(void)
868 {
869 
870 	(void)fprintf(stderr, "%s\n%s\n%s\n",
871 "usage: mount [-adflpruvw] [-F fstab] [-o options] [-t ufs | external_type]",
872 "       mount [-dfpruvw] special | node",
873 "       mount [-dfpruvw] [-o options] [-t ufs | external_type] special node");
874 	exit(1);
875 }
876 
877 void
878 putfsent(struct statfs *ent)
879 {
880 	struct fstab *fst;
881 	char *opts, *rw;
882 	int l;
883 
884 	opts = NULL;
885 	/* flags2opts() doesn't return the "rw" option. */
886 	if ((ent->f_flags & MNT_RDONLY) != 0)
887 		rw = NULL;
888 	else
889 		rw = catopt(NULL, "rw");
890 
891 	opts = flags2opts(ent->f_flags);
892 	opts = catopt(rw, opts);
893 
894 	if (strncmp(ent->f_mntfromname, "<below>", 7) == 0 ||
895 	    strncmp(ent->f_mntfromname, "<above>", 7) == 0) {
896 		strlcpy(ent->f_mntfromname,
897 		    (strnstr(ent->f_mntfromname, ":", 8) +1),
898 		    sizeof(ent->f_mntfromname));
899 	}
900 
901 	l = strlen(ent->f_mntfromname);
902 	printf("%s%s%s%s", ent->f_mntfromname,
903 	    l < 8 ? "\t" : "",
904 	    l < 16 ? "\t" : "",
905 	    l < 24 ? "\t" : " ");
906 	l = strlen(ent->f_mntonname);
907 	printf("%s%s%s%s", ent->f_mntonname,
908 	    l < 8 ? "\t" : "",
909 	    l < 16 ? "\t" : "",
910 	    l < 24 ? "\t" : " ");
911 	printf("%s\t", ent->f_fstypename);
912 	l = strlen(opts);
913 	printf("%s%s", opts,
914 	    l < 8 ? "\t" : " ");
915 	free(opts);
916 
917 	if ((fst = getfsspec(ent->f_mntfromname)))
918 		printf("\t%u %u\n", fst->fs_freq, fst->fs_passno);
919 	else if ((fst = getfsfile(ent->f_mntonname)))
920 		printf("\t%u %u\n", fst->fs_freq, fst->fs_passno);
921 	else if (strcmp(ent->f_fstypename, "ufs") == 0) {
922 		if (strcmp(ent->f_mntonname, "/") == 0)
923 			printf("\t1 1\n");
924 		else
925 			printf("\t2 2\n");
926 	} else
927 		printf("\t0 0\n");
928 }
929 
930 
931 char *
932 flags2opts(int flags)
933 {
934 	char *res;
935 
936 	res = NULL;
937 
938 	if (flags & MNT_RDONLY)		res = catopt(res, "ro");
939 	if (flags & MNT_SYNCHRONOUS)	res = catopt(res, "sync");
940 	if (flags & MNT_NOEXEC)		res = catopt(res, "noexec");
941 	if (flags & MNT_NOSUID)		res = catopt(res, "nosuid");
942 	if (flags & MNT_UNION)		res = catopt(res, "union");
943 	if (flags & MNT_ASYNC)		res = catopt(res, "async");
944 	if (flags & MNT_NOATIME)	res = catopt(res, "noatime");
945 	if (flags & MNT_NOCLUSTERR)	res = catopt(res, "noclusterr");
946 	if (flags & MNT_NOCLUSTERW)	res = catopt(res, "noclusterw");
947 	if (flags & MNT_NOSYMFOLLOW)	res = catopt(res, "nosymfollow");
948 	if (flags & MNT_SUIDDIR)	res = catopt(res, "suiddir");
949 	if (flags & MNT_MULTILABEL)	res = catopt(res, "multilabel");
950 	if (flags & MNT_ACLS)		res = catopt(res, "acls");
951 	if (flags & MNT_NFS4ACLS)	res = catopt(res, "nfsv4acls");
952 	if (flags & MNT_UNTRUSTED)	res = catopt(res, "untrusted");
953 	if (flags & MNT_NOCOVER)	res = catopt(res, "nocover");
954 	if (flags & MNT_EMPTYDIR)	res = catopt(res, "emptydir");
955 
956 	return (res);
957 }
958