xref: /freebsd/sbin/mount/mount.c (revision 43764a7ffa9ad6eba3275410bc2397d3d398f75f)
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 #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 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_MULTILABEL,	"multilabel" },
113 	{ MNT_ACLS,		"acls" },
114 	{ MNT_NFS4ACLS,		"nfsv4acls" },
115 	{ MNT_GJOURNAL,		"gjournal" },
116 	{ 0, NULL }
117 };
118 
119 /*
120  * List of VFS types that can be remounted without becoming mounted on top
121  * of each other.
122  * XXX Is this list correct?
123  */
124 static const char *
125 remountable_fs_names[] = {
126 	"ufs", "ffs", "ext2fs",
127 	0
128 };
129 
130 static const char userquotaeq[] = "userquota=";
131 static const char groupquotaeq[] = "groupquota=";
132 
133 static char *mountprog = NULL;
134 
135 static int
136 use_mountprog(const char *vfstype)
137 {
138 	/* XXX: We need to get away from implementing external mount
139 	 *      programs for every filesystem, and move towards having
140 	 *	each filesystem properly implement the nmount() system call.
141 	 */
142 	unsigned int i;
143 	const char *fs[] = {
144 	"cd9660", "mfs", "msdosfs", "nfs", "ntfs",
145 	"nwfs", "nullfs", "oldnfs", "portalfs", "smbfs", "udf", "unionfs",
146 	NULL
147 	};
148 
149 	if (mountprog != NULL)
150 		return (1);
151 
152 	for (i = 0; fs[i] != NULL; ++i) {
153 		if (strcmp(vfstype, fs[i]) == 0)
154 			return (1);
155 	}
156 
157 	return (0);
158 }
159 
160 static int
161 exec_mountprog(const char *name, const char *execname, char *const argv[])
162 {
163 	pid_t pid;
164 	int status;
165 
166 	switch (pid = fork()) {
167 	case -1:				/* Error. */
168 		warn("fork");
169 		exit (1);
170 	case 0:					/* Child. */
171 		/* Go find an executable. */
172 		execvP(execname, _PATH_SYSPATH, argv);
173 		if (errno == ENOENT) {
174 			warn("exec %s not found", execname);
175 			if (execname[0] != '/') {
176 				warnx("in path: %s", _PATH_SYSPATH);
177 			}
178 		}
179 		exit(1);
180 	default:				/* Parent. */
181 		if (waitpid(pid, &status, 0) < 0) {
182 			warn("waitpid");
183 			return (1);
184 		}
185 
186 		if (WIFEXITED(status)) {
187 			if (WEXITSTATUS(status) != 0)
188 				return (WEXITSTATUS(status));
189 		} else if (WIFSIGNALED(status)) {
190 			warnx("%s: %s", name, sys_siglist[WTERMSIG(status)]);
191 			return (1);
192 		}
193 		break;
194 	}
195 
196 	return (0);
197 }
198 
199 static int
200 specified_ro(const char *arg)
201 {
202 	char *optbuf, *opt;
203 	int ret = 0;
204 
205 	optbuf = strdup(arg);
206 	if (optbuf == NULL)
207 		 err(1, NULL);
208 
209 	for (opt = optbuf; (opt = strtok(opt, ",")) != NULL; opt = NULL) {
210 		if (strcmp(opt, "ro") == 0) {
211 			ret = 1;
212 			break;
213 		}
214 	}
215 	free(optbuf);
216 	return (ret);
217 }
218 
219 static void
220 restart_mountd(void)
221 {
222 	struct pidfh *pfh;
223 	pid_t mountdpid;
224 
225 	pfh = pidfile_open(_PATH_MOUNTDPID, 0600, &mountdpid);
226 	if (pfh != NULL) {
227 		/* Mountd is not running. */
228 		pidfile_remove(pfh);
229 		return;
230 	}
231 	if (errno != EEXIST) {
232 		/* Cannot open pidfile for some reason. */
233 		return;
234 	}
235 	/* We have mountd(8) PID in mountdpid varible, let's signal it. */
236 	if (kill(mountdpid, SIGHUP) == -1)
237 		err(1, "signal mountd");
238 }
239 
240 int
241 main(int argc, char *argv[])
242 {
243 	const char *mntfromname, **vfslist, *vfstype;
244 	struct fstab *fs;
245 	struct statfs *mntbuf;
246 	int all, ch, i, init_flags, late, failok, mntsize, rval, have_fstab, ro;
247 	char *cp, *ep, *options;
248 
249 	all = init_flags = late = 0;
250 	ro = 0;
251 	options = NULL;
252 	vfslist = NULL;
253 	vfstype = "ufs";
254 	while ((ch = getopt(argc, argv, "adF:flo:prt:uvw")) != -1)
255 		switch (ch) {
256 		case 'a':
257 			all = 1;
258 			break;
259 		case 'd':
260 			debug = 1;
261 			break;
262 		case 'F':
263 			setfstab(optarg);
264 			break;
265 		case 'f':
266 			init_flags |= MNT_FORCE;
267 			break;
268 		case 'l':
269 			late = 1;
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, MNT_NOWAIT)) == 0)
320 			err(1, "getmntinfo");
321 		if (all) {
322 			while ((fs = getfsent()) != NULL) {
323 				if (BADTYPE(fs->fs_type))
324 					continue;
325 				if (checkvfsname(fs->fs_vfstype, vfslist))
326 					continue;
327 				if (hasopt(fs->fs_mntops, "noauto"))
328 					continue;
329 				if (hasopt(fs->fs_mntops, "late") && !late)
330 					continue;
331 				if (hasopt(fs->fs_mntops, "failok"))
332 					failok = 1;
333 				else
334 					failok = 0;
335 				if (!(init_flags & MNT_UPDATE) &&
336 				    ismounted(fs, mntbuf, mntsize))
337 					continue;
338 				options = update_options(options, fs->fs_mntops,
339 				    mntbuf->f_flags);
340 				if (mountfs(fs->fs_vfstype, fs->fs_spec,
341 				    fs->fs_file, init_flags, options,
342 				    fs->fs_mntops) && !failok)
343 					rval = 1;
344 			}
345 		} else if (fstab_style) {
346 			for (i = 0; i < mntsize; i++) {
347 				if (checkvfsname(mntbuf[i].f_fstypename, vfslist))
348 					continue;
349 				putfsent(&mntbuf[i]);
350 			}
351 		} else {
352 			for (i = 0; i < mntsize; i++) {
353 				if (checkvfsname(mntbuf[i].f_fstypename,
354 				    vfslist))
355 					continue;
356 				if (!verbose &&
357 				    (mntbuf[i].f_flags & MNT_IGNORE) != 0)
358 					continue;
359 				prmount(&mntbuf[i]);
360 			}
361 		}
362 		exit(rval);
363 	case 1:
364 		if (vfslist != NULL)
365 			usage();
366 
367 		rmslashes(*argv, *argv);
368 		if (init_flags & MNT_UPDATE) {
369 			mntfromname = NULL;
370 			have_fstab = 0;
371 			if ((mntbuf = getmntpt(*argv)) == NULL)
372 				errx(1, "not currently mounted %s", *argv);
373 			/*
374 			 * Only get the mntflags from fstab if both mntpoint
375 			 * and mntspec are identical. Also handle the special
376 			 * case where just '/' is mounted and 'spec' is not
377 			 * identical with the one from fstab ('/dev' is missing
378 			 * in the spec-string at boot-time).
379 			 */
380 			if ((fs = getfsfile(mntbuf->f_mntonname)) != NULL) {
381 				if (strcmp(fs->fs_spec,
382 				    mntbuf->f_mntfromname) == 0 &&
383 				    strcmp(fs->fs_file,
384 				    mntbuf->f_mntonname) == 0) {
385 					have_fstab = 1;
386 					mntfromname = mntbuf->f_mntfromname;
387 				} else if (argv[0][0] == '/' &&
388 				    argv[0][1] == '\0') {
389 					fs = getfsfile("/");
390 					have_fstab = 1;
391 					mntfromname = fs->fs_spec;
392 				}
393 			}
394 			if (have_fstab) {
395 				options = update_options(options, fs->fs_mntops,
396 				    mntbuf->f_flags);
397 			} else {
398 				mntfromname = mntbuf->f_mntfromname;
399 				options = update_options(options, NULL,
400 				    mntbuf->f_flags);
401 			}
402 			rval = mountfs(mntbuf->f_fstypename, mntfromname,
403 			    mntbuf->f_mntonname, init_flags, options, 0);
404 			break;
405 		}
406 		if ((fs = getfsfile(*argv)) == NULL &&
407 		    (fs = getfsspec(*argv)) == NULL)
408 			errx(1, "%s: unknown special file or file system",
409 			    *argv);
410 		if (BADTYPE(fs->fs_type))
411 			errx(1, "%s has unknown file system type",
412 			    *argv);
413 		rval = mountfs(fs->fs_vfstype, fs->fs_spec, fs->fs_file,
414 		    init_flags, options, fs->fs_mntops);
415 		break;
416 	case 2:
417 		/*
418 		 * If -t flag has not been specified, the path cannot be
419 		 * found, spec contains either a ':' or a '@', then assume
420 		 * that an NFS file system is being specified ala Sun.
421 		 * Check if the hostname contains only allowed characters
422 		 * to reduce false positives.  IPv6 addresses containing
423 		 * ':' will be correctly parsed only if the separator is '@'.
424 		 * The definition of a valid hostname is taken from RFC 1034.
425 		 */
426 		if (vfslist == NULL && ((ep = strchr(argv[0], '@')) != NULL ||
427 		    (ep = strchr(argv[0], ':')) != NULL)) {
428 			if (*ep == '@') {
429 				cp = ep + 1;
430 				ep = cp + strlen(cp);
431 			} else
432 				cp = argv[0];
433 			while (cp != ep) {
434 				if (!isdigit(*cp) && !isalpha(*cp) &&
435 				    *cp != '.' && *cp != '-' && *cp != ':')
436 					break;
437 				cp++;
438 			}
439 			if (cp == ep)
440 				vfstype = "nfs";
441 		}
442 		rval = mountfs(vfstype,
443 		    argv[0], argv[1], init_flags, options, NULL);
444 		break;
445 	default:
446 		usage();
447 		/* NOTREACHED */
448 	}
449 
450 	/*
451 	 * If the mount was successfully, and done by root, tell mountd the
452 	 * good news.
453 	 */
454 	if (rval == 0 && getuid() == 0)
455 		restart_mountd();
456 
457 	exit(rval);
458 }
459 
460 int
461 ismounted(struct fstab *fs, struct statfs *mntbuf, int mntsize)
462 {
463 	char realfsfile[PATH_MAX];
464 	int i;
465 
466 	if (fs->fs_file[0] == '/' && fs->fs_file[1] == '\0')
467 		/* the root file system can always be remounted */
468 		return (0);
469 
470 	/* The user may have specified a symlink in fstab, resolve the path */
471 	if (realpath(fs->fs_file, realfsfile) == NULL) {
472 		/* Cannot resolve the path, use original one */
473 		strlcpy(realfsfile, fs->fs_file, sizeof(realfsfile));
474 	}
475 
476 	for (i = mntsize - 1; i >= 0; --i)
477 		if (strcmp(realfsfile, mntbuf[i].f_mntonname) == 0 &&
478 		    (!isremountable(fs->fs_vfstype) ||
479 		     strcmp(fs->fs_spec, mntbuf[i].f_mntfromname) == 0))
480 			return (1);
481 	return (0);
482 }
483 
484 int
485 isremountable(const char *vfsname)
486 {
487 	const char **cp;
488 
489 	for (cp = remountable_fs_names; *cp; cp++)
490 		if (strcmp(*cp, vfsname) == 0)
491 			return (1);
492 	return (0);
493 }
494 
495 int
496 hasopt(const char *mntopts, const char *option)
497 {
498 	int negative, found;
499 	char *opt, *optbuf;
500 
501 	if (option[0] == 'n' && option[1] == 'o') {
502 		negative = 1;
503 		option += 2;
504 	} else
505 		negative = 0;
506 	optbuf = strdup(mntopts);
507 	found = 0;
508 	for (opt = optbuf; (opt = strtok(opt, ",")) != NULL; opt = NULL) {
509 		if (opt[0] == 'n' && opt[1] == 'o') {
510 			if (!strcasecmp(opt + 2, option))
511 				found = negative;
512 		} else if (!strcasecmp(opt, option))
513 			found = !negative;
514 	}
515 	free(optbuf);
516 	return (found);
517 }
518 
519 static void
520 append_arg(struct cpa *sa, char *arg)
521 {
522 	if (sa->c + 1 == sa->sz) {
523 		sa->sz = sa->sz == 0 ? 8 : sa->sz * 2;
524 		sa->a = realloc(sa->a, sizeof(sa->a) * sa->sz);
525 		if (sa->a == NULL)
526 			errx(1, "realloc failed");
527 	}
528 	sa->a[++sa->c] = arg;
529 }
530 
531 int
532 mountfs(const char *vfstype, const char *spec, const char *name, int flags,
533 	const char *options, const char *mntopts)
534 {
535 	struct statfs sf;
536 	int i, ret;
537 	char *optbuf, execname[PATH_MAX], mntpath[PATH_MAX];
538 	static struct cpa mnt_argv;
539 
540 	/* resolve the mountpoint with realpath(3) */
541 	(void)checkpath(name, mntpath);
542 	name = mntpath;
543 
544 	if (mntopts == NULL)
545 		mntopts = "";
546 	optbuf = catopt(strdup(mntopts), options);
547 
548 	if (strcmp(name, "/") == 0)
549 		flags |= MNT_UPDATE;
550 	if (flags & MNT_FORCE)
551 		optbuf = catopt(optbuf, "force");
552 	if (flags & MNT_RDONLY)
553 		optbuf = catopt(optbuf, "ro");
554 	/*
555 	 * XXX
556 	 * The mount_mfs (newfs) command uses -o to select the
557 	 * optimization mode.  We don't pass the default "-o rw"
558 	 * for that reason.
559 	 */
560 	if (flags & MNT_UPDATE)
561 		optbuf = catopt(optbuf, "update");
562 
563 	/* Compatibility glue. */
564 	if (strcmp(vfstype, "msdos") == 0) {
565 		warnx(
566 		    "Using \"-t msdosfs\", since \"-t msdos\" is deprecated.");
567 		vfstype = "msdosfs";
568 	}
569 
570 	/* Construct the name of the appropriate mount command */
571 	(void)snprintf(execname, sizeof(execname), "mount_%s", vfstype);
572 
573 	mnt_argv.c = -1;
574 	append_arg(&mnt_argv, execname);
575 	mangle(optbuf, &mnt_argv);
576 	if (mountprog != NULL)
577 		strcpy(execname, mountprog);
578 
579 	append_arg(&mnt_argv, strdup(spec));
580 	append_arg(&mnt_argv, strdup(name));
581 	append_arg(&mnt_argv, NULL);
582 
583 	if (debug) {
584 		if (use_mountprog(vfstype))
585 			printf("exec: %s", execname);
586 		else
587 			printf("mount -t %s", vfstype);
588 		for (i = 1; i < mnt_argv.c; i++)
589 			(void)printf(" %s", mnt_argv.a[i]);
590 		(void)printf("\n");
591 		return (0);
592 	}
593 
594 	if (use_mountprog(vfstype)) {
595 		ret = exec_mountprog(name, execname, mnt_argv.a);
596 	} else {
597 		ret = mount_fs(vfstype, mnt_argv.c, mnt_argv.a);
598 	}
599 
600 	free(optbuf);
601 
602 	if (verbose) {
603 		if (statfs(name, &sf) < 0) {
604 			warn("statfs %s", name);
605 			return (1);
606 		}
607 		if (fstab_style)
608 			putfsent(&sf);
609 		else
610 			prmount(&sf);
611 	}
612 
613 	return (ret);
614 }
615 
616 void
617 prmount(struct statfs *sfp)
618 {
619 	uint64_t flags;
620 	unsigned int i;
621 	struct opt *o;
622 	struct passwd *pw;
623 
624 	(void)printf("%s on %s (%s", sfp->f_mntfromname, sfp->f_mntonname,
625 	    sfp->f_fstypename);
626 
627 	flags = sfp->f_flags & MNT_VISFLAGMASK;
628 	for (o = optnames; flags != 0 && o->o_opt != 0; o++)
629 		if (flags & o->o_opt) {
630 			(void)printf(", %s", o->o_name);
631 			flags &= ~o->o_opt;
632 		}
633 	/*
634 	 * Inform when file system is mounted by an unprivileged user
635 	 * or privileged non-root user.
636 	 */
637 	if ((flags & MNT_USER) != 0 || sfp->f_owner != 0) {
638 		(void)printf(", mounted by ");
639 		if ((pw = getpwuid(sfp->f_owner)) != NULL)
640 			(void)printf("%s", pw->pw_name);
641 		else
642 			(void)printf("%d", sfp->f_owner);
643 	}
644 	if (verbose) {
645 		if (sfp->f_syncwrites != 0 || sfp->f_asyncwrites != 0)
646 			(void)printf(", writes: sync %ju async %ju",
647 			    (uintmax_t)sfp->f_syncwrites,
648 			    (uintmax_t)sfp->f_asyncwrites);
649 		if (sfp->f_syncreads != 0 || sfp->f_asyncreads != 0)
650 			(void)printf(", reads: sync %ju async %ju",
651 			    (uintmax_t)sfp->f_syncreads,
652 			    (uintmax_t)sfp->f_asyncreads);
653 		if (sfp->f_fsid.val[0] != 0 || sfp->f_fsid.val[1] != 0) {
654 			printf(", fsid ");
655 			for (i = 0; i < sizeof(sfp->f_fsid); i++)
656 				printf("%02x", ((u_char *)&sfp->f_fsid)[i]);
657 		}
658 	}
659 	(void)printf(")\n");
660 }
661 
662 struct statfs *
663 getmntpt(const char *name)
664 {
665 	struct statfs *mntbuf;
666 	int i, mntsize;
667 
668 	mntsize = getmntinfo(&mntbuf, MNT_NOWAIT);
669 	for (i = mntsize - 1; i >= 0; i--) {
670 		if (strcmp(mntbuf[i].f_mntfromname, name) == 0 ||
671 		    strcmp(mntbuf[i].f_mntonname, name) == 0)
672 			return (&mntbuf[i]);
673 	}
674 	return (NULL);
675 }
676 
677 char *
678 catopt(char *s0, const char *s1)
679 {
680 	size_t i;
681 	char *cp;
682 
683 	if (s1 == NULL || *s1 == '\0')
684 		return (s0);
685 
686 	if (s0 && *s0) {
687 		i = strlen(s0) + strlen(s1) + 1 + 1;
688 		if ((cp = malloc(i)) == NULL)
689 			errx(1, "malloc failed");
690 		(void)snprintf(cp, i, "%s,%s", s0, s1);
691 	} else
692 		cp = strdup(s1);
693 
694 	if (s0)
695 		free(s0);
696 	return (cp);
697 }
698 
699 void
700 mangle(char *options, struct cpa *a)
701 {
702 	char *p, *s, *val;
703 
704 	for (s = options; (p = strsep(&s, ",")) != NULL;)
705 		if (*p != '\0') {
706 			if (strcmp(p, "noauto") == 0) {
707 				/*
708 				 * Do not pass noauto option to nmount().
709 				 * or external mount program.  noauto is
710 				 * only used to prevent mounting a filesystem
711 				 * when 'mount -a' is specified, and is
712 				 * not a real mount option.
713 				 */
714 				continue;
715 			} else if (strcmp(p, "late") == 0) {
716 				/*
717 				 * "late" is used to prevent certain file
718 				 * systems from being mounted before late
719 				 * in the boot cycle; for instance,
720 				 * loopback NFS mounts can't be mounted
721 				 * before mountd starts.
722 				 */
723 				continue;
724 			} else if (strcmp(p, "failok") == 0) {
725 				/*
726 				 * "failok" is used to prevent certain file
727 				 * systems from being causing the system to
728 				 * drop into single user mode in the boot
729 				 * cycle, and is not a real mount option.
730 				 */
731 				continue;
732 			} else if (strncmp(p, "mountprog", 9) == 0) {
733 				/*
734 				 * "mountprog" is used to force the use of
735 				 * userland mount programs.
736 				 */
737 				val = strchr(p, '=');
738                         	if (val != NULL) {
739                                 	++val;
740 					if (*val != '\0')
741 						mountprog = strdup(val);
742 				}
743 
744 				if (mountprog == NULL) {
745 					errx(1, "Need value for -o mountprog");
746 				}
747 				continue;
748 			} else if (strcmp(p, "userquota") == 0) {
749 				continue;
750 			} else if (strncmp(p, userquotaeq,
751 			    sizeof(userquotaeq) - 1) == 0) {
752 				continue;
753 			} else if (strcmp(p, "groupquota") == 0) {
754 				continue;
755 			} else if (strncmp(p, groupquotaeq,
756 			    sizeof(groupquotaeq) - 1) == 0) {
757 				continue;
758 			} else if (*p == '-') {
759 				append_arg(a, p);
760 				p = strchr(p, '=');
761 				if (p != NULL) {
762 					*p = '\0';
763 					append_arg(a, p + 1);
764 				}
765 			} else {
766 				append_arg(a, strdup("-o"));
767 				append_arg(a, p);
768 			}
769 		}
770 }
771 
772 
773 char *
774 update_options(char *opts, char *fstab, int curflags)
775 {
776 	char *o, *p;
777 	char *cur;
778 	char *expopt, *newopt, *tmpopt;
779 
780 	if (opts == NULL)
781 		return (strdup(""));
782 
783 	/* remove meta options from list */
784 	remopt(fstab, MOUNT_META_OPTION_FSTAB);
785 	remopt(fstab, MOUNT_META_OPTION_CURRENT);
786 	cur = flags2opts(curflags);
787 
788 	/*
789 	 * Expand all meta-options passed to us first.
790 	 */
791 	expopt = NULL;
792 	for (p = opts; (o = strsep(&p, ",")) != NULL;) {
793 		if (strcmp(MOUNT_META_OPTION_FSTAB, o) == 0)
794 			expopt = catopt(expopt, fstab);
795 		else if (strcmp(MOUNT_META_OPTION_CURRENT, o) == 0)
796 			expopt = catopt(expopt, cur);
797 		else
798 			expopt = catopt(expopt, o);
799 	}
800 	free(cur);
801 	free(opts);
802 
803 	/*
804 	 * Remove previous contradictory arguments. Given option "foo" we
805 	 * remove all the "nofoo" options. Given "nofoo" we remove "nonofoo"
806 	 * and "foo" - so we can deal with possible options like "notice".
807 	 */
808 	newopt = NULL;
809 	for (p = expopt; (o = strsep(&p, ",")) != NULL;) {
810 		if ((tmpopt = malloc( strlen(o) + 2 + 1 )) == NULL)
811 			errx(1, "malloc failed");
812 
813 		strcpy(tmpopt, "no");
814 		strcat(tmpopt, o);
815 		remopt(newopt, tmpopt);
816 		free(tmpopt);
817 
818 		if (strncmp("no", o, 2) == 0)
819 			remopt(newopt, o+2);
820 
821 		newopt = catopt(newopt, o);
822 	}
823 	free(expopt);
824 
825 	return (newopt);
826 }
827 
828 void
829 remopt(char *string, const char *opt)
830 {
831 	char *o, *p, *r;
832 
833 	if (string == NULL || *string == '\0' || opt == NULL || *opt == '\0')
834 		return;
835 
836 	r = string;
837 
838 	for (p = string; (o = strsep(&p, ",")) != NULL;) {
839 		if (strcmp(opt, o) != 0) {
840 			if (*r == ',' && *o != '\0')
841 				r++;
842 			while ((*r++ = *o++) != '\0')
843 			    ;
844 			*--r = ',';
845 		}
846 	}
847 	*r = '\0';
848 }
849 
850 void
851 usage(void)
852 {
853 
854 	(void)fprintf(stderr, "%s\n%s\n%s\n",
855 "usage: mount [-adflpruvw] [-F fstab] [-o options] [-t ufs | external_type]",
856 "       mount [-dfpruvw] special | node",
857 "       mount [-dfpruvw] [-o options] [-t ufs | external_type] special node");
858 	exit(1);
859 }
860 
861 void
862 putfsent(struct statfs *ent)
863 {
864 	struct fstab *fst;
865 	char *opts, *rw;
866 	int l;
867 
868 	opts = NULL;
869 	/* flags2opts() doesn't return the "rw" option. */
870 	if ((ent->f_flags & MNT_RDONLY) != 0)
871 		rw = NULL;
872 	else
873 		rw = catopt(NULL, "rw");
874 
875 	opts = flags2opts(ent->f_flags);
876 	opts = catopt(rw, opts);
877 
878 	if (strncmp(ent->f_mntfromname, "<below>", 7) == 0 ||
879 	    strncmp(ent->f_mntfromname, "<above>", 7) == 0) {
880 		strcpy(ent->f_mntfromname, (strnstr(ent->f_mntfromname, ":", 8)
881 		    +1));
882 	}
883 
884 	l = strlen(ent->f_mntfromname);
885 	printf("%s%s%s%s", ent->f_mntfromname,
886 	    l < 8 ? "\t" : "",
887 	    l < 16 ? "\t" : "",
888 	    l < 24 ? "\t" : " ");
889 	l = strlen(ent->f_mntonname);
890 	printf("%s%s%s%s", ent->f_mntonname,
891 	    l < 8 ? "\t" : "",
892 	    l < 16 ? "\t" : "",
893 	    l < 24 ? "\t" : " ");
894 	printf("%s\t", ent->f_fstypename);
895 	l = strlen(opts);
896 	printf("%s%s", opts,
897 	    l < 8 ? "\t" : " ");
898 	free(opts);
899 
900 	if ((fst = getfsspec(ent->f_mntfromname)))
901 		printf("\t%u %u\n", fst->fs_freq, fst->fs_passno);
902 	else if ((fst = getfsfile(ent->f_mntonname)))
903 		printf("\t%u %u\n", fst->fs_freq, fst->fs_passno);
904 	else if (strcmp(ent->f_fstypename, "ufs") == 0) {
905 		if (strcmp(ent->f_mntonname, "/") == 0)
906 			printf("\t1 1\n");
907 		else
908 			printf("\t2 2\n");
909 	} else
910 		printf("\t0 0\n");
911 }
912 
913 
914 char *
915 flags2opts(int flags)
916 {
917 	char *res;
918 
919 	res = NULL;
920 
921 	if (flags & MNT_RDONLY)		res = catopt(res, "ro");
922 	if (flags & MNT_SYNCHRONOUS)	res = catopt(res, "sync");
923 	if (flags & MNT_NOEXEC)		res = catopt(res, "noexec");
924 	if (flags & MNT_NOSUID)		res = catopt(res, "nosuid");
925 	if (flags & MNT_UNION)		res = catopt(res, "union");
926 	if (flags & MNT_ASYNC)		res = catopt(res, "async");
927 	if (flags & MNT_NOATIME)	res = catopt(res, "noatime");
928 	if (flags & MNT_NOCLUSTERR)	res = catopt(res, "noclusterr");
929 	if (flags & MNT_NOCLUSTERW)	res = catopt(res, "noclusterw");
930 	if (flags & MNT_NOSYMFOLLOW)	res = catopt(res, "nosymfollow");
931 	if (flags & MNT_SUIDDIR)	res = catopt(res, "suiddir");
932 	if (flags & MNT_MULTILABEL)	res = catopt(res, "multilabel");
933 	if (flags & MNT_ACLS)		res = catopt(res, "acls");
934 	if (flags & MNT_NFS4ACLS)	res = catopt(res, "nfsv4acls");
935 
936 	return (res);
937 }
938