xref: /netbsd-src/sbin/mount/mount.c (revision c8da0e5fefd3800856b306200a18b2315c7fbb9f)
1 /*	$NetBSD: mount.c,v 1.89 2009/05/04 11:41:48 yamt Exp $	*/
2 
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 #include <sys/cdefs.h>
33 #ifndef lint
34 __COPYRIGHT("@(#) Copyright (c) 1980, 1989, 1993, 1994\
35  The Regents of the University of California.  All rights reserved.");
36 #endif /* not lint */
37 
38 #ifndef lint
39 #if 0
40 static char sccsid[] = "@(#)mount.c	8.25 (Berkeley) 5/8/95";
41 #else
42 __RCSID("$NetBSD: mount.c,v 1.89 2009/05/04 11:41:48 yamt Exp $");
43 #endif
44 #endif /* not lint */
45 
46 #include <sys/param.h>
47 #include <sys/mount.h>
48 #include <sys/wait.h>
49 
50 #include <err.h>
51 #include <errno.h>
52 #include <fstab.h>
53 #include <pwd.h>
54 #include <signal.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <string.h>
58 #include <unistd.h>
59 
60 #define MOUNTNAMES
61 #include <fcntl.h>
62 #include <sys/disk.h>
63 #include <sys/disklabel.h>
64 #include <sys/ioctl.h>
65 
66 #include "pathnames.h"
67 #include "mountprog.h"
68 
69 static int	debug, verbose;
70 
71 static void	catopt(char **, const char *);
72 static const char *
73 		getfslab(const char *str);
74 static struct statvfs *
75 		getmntpt(const char *);
76 static int 	getmntargs(struct statvfs *, char *, size_t);
77 static int	hasopt(const char *, const char *);
78 static void	mangle(char *, int *, const char ** volatile *, int *);
79 static int	mountfs(const char *, const char *, const char *,
80 		    int, const char *, const char *, int, char *, size_t);
81 static void	prmount(struct statvfs *);
82 static void	usage(void);
83 
84 
85 /* Map from mount otions to printable formats. */
86 static const struct opt {
87 	int o_opt;
88 	int o_silent;
89 	const char *o_name;
90 } optnames[] = {
91 	__MNT_FLAGS
92 };
93 
94 static char ffs_fstype[] = "ffs";
95 
96 int
97 main(int argc, char *argv[])
98 {
99 	const char *mntfromname, *mntonname, **vfslist, *vfstype;
100 	struct fstab *fs;
101 	struct statvfs *mntbuf;
102 #if 0
103 	FILE *mountdfp;
104 #endif
105 	int all, ch, forceall, i, init_flags, mntsize, rval;
106 	char *options;
107 	const char *mountopts, *fstypename;
108 	char canonical_path_buf[MAXPATHLEN];
109 	char *canonical_path;
110 
111 	/* started as "mount" */
112 	all = forceall = init_flags = 0;
113 	options = NULL;
114 	vfslist = NULL;
115 	vfstype = ffs_fstype;
116 	while ((ch = getopt(argc, argv, "Aadfo:rwt:uv")) != -1)
117 		switch (ch) {
118 		case 'A':
119 			all = forceall = 1;
120 			break;
121 		case 'a':
122 			all = 1;
123 			break;
124 		case 'd':
125 			debug = 1;
126 			break;
127 		case 'f':
128 			init_flags |= MNT_FORCE;
129 			break;
130 		case 'o':
131 			if (*optarg)
132 				catopt(&options, optarg);
133 			break;
134 		case 'r':
135 			init_flags |= MNT_RDONLY;
136 			break;
137 		case 't':
138 			if (vfslist != NULL)
139 				errx(1,
140 				    "only one -t option may be specified.");
141 			vfslist = makevfslist(optarg);
142 			vfstype = optarg;
143 			break;
144 		case 'u':
145 			init_flags |= MNT_UPDATE;
146 			break;
147 		case 'v':
148 			verbose++;
149 			break;
150 		case 'w':
151 			init_flags &= ~MNT_RDONLY;
152 			break;
153 		case '?':
154 		default:
155 			usage();
156 			/* NOTREACHED */
157 		}
158 	argc -= optind;
159 	argv += optind;
160 
161 #define	BADTYPE(type)							\
162 	(strcmp(type, FSTAB_RO) &&					\
163 	    strcmp(type, FSTAB_RW) && strcmp(type, FSTAB_RQ))
164 
165 	rval = 0;
166 	switch (argc) {
167 	case 0:
168 		if (all)
169 			while ((fs = getfsent()) != NULL) {
170 				if (BADTYPE(fs->fs_type))
171 					continue;
172 				if (checkvfsname(fs->fs_vfstype, vfslist))
173 					continue;
174 				if (hasopt(fs->fs_mntops, "noauto"))
175 					continue;
176 				if (strcmp(fs->fs_spec, "from_mount") == 0) {
177 					if ((mntbuf = getmntpt(fs->fs_file)) == NULL)
178 						errx(1,
179 						    "unknown file system %s.",
180 						    fs->fs_file);
181 					mntfromname = mntbuf->f_mntfromname;
182 				} else
183 					mntfromname = fs->fs_spec;
184 				if (mountfs(fs->fs_vfstype, mntfromname,
185 				    fs->fs_file, init_flags, options,
186 				    fs->fs_mntops, !forceall, NULL, 0))
187 					rval = 1;
188 			}
189 		else {
190 			if ((mntsize = getmntinfo(&mntbuf, MNT_NOWAIT)) == 0)
191 				err(1, "getmntinfo");
192 			for (i = 0; i < mntsize; i++) {
193 				if (checkvfsname(mntbuf[i].f_fstypename,
194 				    vfslist))
195 					continue;
196 				prmount(&mntbuf[i]);
197 			}
198 		}
199 		exit(rval);
200 		/* NOTREACHED */
201 	case 1:
202 		if (vfslist != NULL) {
203 			usage();
204 			/* NOTREACHED */
205 		}
206 
207 		/*
208 		 * Create a canonical version of the device or mount path
209 		 * passed to us.  It's ok for this to fail.  It's also ok
210 		 * for the result to be exactly the same as the original.
211 		 */
212 		canonical_path = realpath(*argv, canonical_path_buf);
213 
214 		if (init_flags & MNT_UPDATE) {
215 			/*
216 			 * Try looking up the canonical path first,
217 			 * then try exactly what the user entered.
218 			 */
219 			if ((canonical_path == NULL ||
220 			     (mntbuf = getmntpt(canonical_path)) == NULL) &&
221 			    (mntbuf = getmntpt(*argv)) == NULL
222 			   )
223 			{
224 				errx(1,
225 				    "unknown special file or file system %s.",
226 				    *argv);
227 			}
228 			mntfromname = mntbuf->f_mntfromname;
229 			if ((fs = getfsfile(mntbuf->f_mntonname)) != NULL) {
230 				if (strcmp(fs->fs_spec, "from_mount") != 0)
231 					mntfromname = fs->fs_spec;
232 				/* ignore the fstab file options.  */
233 				fs->fs_mntops = NULL;
234 			}
235 			mntonname  = mntbuf->f_mntonname;
236 			fstypename = mntbuf->f_fstypename;
237 			mountopts  = NULL;
238 		} else {
239 			/*
240 			 * Try looking up the canonical path first,
241 			 * then try exactly what the user entered.
242 			 */
243 			if (canonical_path == NULL ||
244 			    ((fs = getfsfile(canonical_path)) == NULL &&
245 			     (fs = getfsspec(canonical_path)) == NULL))
246 			{
247 				if ((fs = getfsfile(*argv)) == NULL &&
248 				    (fs = getfsspec(*argv)) == NULL)
249 				{
250 					errx(1,
251 					    "%s: unknown special file or file system.",
252 					    *argv);
253 				}
254 			}
255 			if (BADTYPE(fs->fs_type))
256 				errx(1, "%s has unknown file system type.",
257 				    *argv);
258 			if (strcmp(fs->fs_spec, "from_mount") == 0) {
259 				if ((canonical_path == NULL ||
260 				     (mntbuf = getmntpt(canonical_path)) == NULL) &&
261 				    (mntbuf = getmntpt(*argv)) == NULL
262 				   )
263 				{
264 					errx(1,
265 					    "unknown special file or file system %s.",
266 					    *argv);
267 				}
268 				mntfromname = mntbuf->f_mntfromname;
269 			} else
270 				mntfromname = fs->fs_spec;
271 			mntonname   = fs->fs_file;
272 			fstypename  = fs->fs_vfstype;
273 			mountopts   = fs->fs_mntops;
274 		}
275 		rval = mountfs(fstypename, mntfromname,
276 		    mntonname, init_flags, options, mountopts, 0, NULL, 0);
277 		break;
278 	case 2:
279 		/*
280 		 * If -t flag has not been specified, and spec contains either
281 		 * a ':' or a '@' then assume that an NFS filesystem is being
282 		 * specified ala Sun.
283 		 */
284 		if (vfslist == NULL) {
285 			if (strpbrk(argv[0], ":@") != NULL) {
286 				fprintf(stderr, "WARNING: autoselecting nfs "
287 				    "based on : or @ in the device name is "
288 				    "deprecated!\n"
289 				    "WARNING: This behaviour will be removed "
290 				    "in a future release\n");
291 				vfstype = "nfs";
292 			} else {
293 				vfstype = getfslab(argv[0]);
294 				if (vfstype == NULL)
295 					vfstype = ffs_fstype;
296 			}
297 		}
298 		rval = mountfs(vfstype,
299 		    argv[0], argv[1], init_flags, options, NULL, 0, NULL, 0);
300 		break;
301 	default:
302 		usage();
303 		/* NOTREACHED */
304 	}
305 
306 #if 0	/* disabled because it interferes the service. */
307 	/*
308 	 * If the mount was successfully, and done by root, tell mountd the
309 	 * good news.  Pid checks are probably unnecessary, but don't hurt.
310 	 */
311 	if (rval == 0 && getuid() == 0 &&
312 	    (mountdfp = fopen(_PATH_MOUNTDPID, "r")) != NULL) {
313 		int pid;
314 
315 		if (fscanf(mountdfp, "%d", &pid) == 1 &&
316 		    pid > 0 && kill(pid, SIGHUP) == -1 && errno != ESRCH)
317 			err(1, "signal mountd");
318 		(void)fclose(mountdfp);
319 	}
320 #endif
321 
322 	exit(rval);
323 	/* NOTREACHED */
324 }
325 
326 int
327 hasopt(const char *mntopts, const char *option)
328 {
329 	int negative, found;
330 	char *opt, *optbuf;
331 
332 	if (option[0] == 'n' && option[1] == 'o') {
333 		negative = 1;
334 		option += 2;
335 	} else
336 		negative = 0;
337 	optbuf = strdup(mntopts);
338 	found = 0;
339 	for (opt = optbuf; (opt = strtok(opt, ",")) != NULL; opt = NULL) {
340 		if (opt[0] == 'n' && opt[1] == 'o') {
341 			if (!strcasecmp(opt + 2, option))
342 				found = negative;
343 		} else if (!strcasecmp(opt, option))
344 			found = !negative;
345 	}
346 	free(optbuf);
347 	return (found);
348 }
349 
350 static int
351 mountfs(const char *vfstype, const char *spec, const char *name,
352 	int flags, const char *options, const char *mntopts,
353 	int skipmounted, char *buf, size_t buflen)
354 {
355 	/* List of directories containing mount_xxx subcommands. */
356 	static const char *edirs[] = {
357 #ifdef RESCUEDIR
358 		RESCUEDIR,
359 #endif
360 		_PATH_SBIN,
361 		_PATH_USRSBIN,
362 		NULL
363 	};
364 	const char ** volatile argv, **edir;
365 	struct statvfs *sfp, sf;
366 	pid_t pid;
367 	int pfd[2];
368 	int argc, numfs, i, status, maxargc;
369 	char *optbuf, execname[MAXPATHLEN + 1], execbase[MAXPATHLEN],
370 	    mntpath[MAXPATHLEN];
371 	volatile int getargs;
372 
373 	if (realpath(name, mntpath) == NULL) {
374 		warn("realpath %s", name);
375 		return (1);
376 	}
377 
378 	name = mntpath;
379 
380 	optbuf = NULL;
381 	if (mntopts)
382 		catopt(&optbuf, mntopts);
383 
384 	if (options) {
385 		catopt(&optbuf, options);
386 		getargs = strstr(options, "getargs") != NULL;
387 	} else
388 		getargs = 0;
389 
390 	if (!mntopts && !options)
391 		catopt(&optbuf, "rw");
392 
393 	if (getargs == 0 && strcmp(name, "/") == 0)
394 		flags |= MNT_UPDATE;
395 	else if (skipmounted) {
396 		if ((numfs = getmntinfo(&sfp, MNT_WAIT)) == 0) {
397 			warn("getmntinfo");
398 			return (1);
399 		}
400 		for(i = 0; i < numfs; i++) {
401 			/*
402 			 * XXX can't check f_mntfromname,
403 			 * thanks to mfs, union, etc.
404 			 */
405 			if (strncmp(name, sfp[i].f_mntonname, MNAMELEN) == 0 &&
406 			    strncmp(vfstype, sfp[i].f_fstypename,
407 				sizeof(sfp[i].f_fstypename)) == 0) {
408 				if (verbose)
409 					(void)printf("%s on %s type %.*s: "
410 					    "%s\n",
411 					    sfp[i].f_mntfromname,
412 					    sfp[i].f_mntonname,
413 					    (int)sizeof(sfp[i].f_fstypename),
414 					    sfp[i].f_fstypename,
415 					    "already mounted");
416 				return (0);
417 			}
418 		}
419 	}
420 	if (flags & MNT_FORCE)
421 		catopt(&optbuf, "force");
422 	if (flags & MNT_RDONLY)
423 		catopt(&optbuf, "ro");
424 
425 	if (flags & MNT_UPDATE) {
426 		catopt(&optbuf, "update");
427 		/* Figure out the fstype only if we defaulted to ffs */
428 		if (vfstype == ffs_fstype && statvfs(name, &sf) != -1)
429 			vfstype = sf.f_fstypename;
430 	}
431 
432 	maxargc = 64;
433 	argv = malloc(sizeof(char *) * maxargc);
434 	if (argv == NULL)
435 		err(1, "malloc");
436 
437 	if (hasopt(optbuf, "rump"))
438 		(void)snprintf(execbase, sizeof(execbase), "rump_%s", vfstype);
439 	else
440 		(void)snprintf(execbase, sizeof(execbase), "mount_%s", vfstype);
441 	argc = 0;
442 	argv[argc++] = execbase;
443 	if (optbuf)
444 		mangle(optbuf, &argc, &argv, &maxargc);
445 	argv[argc++] = spec;
446 	argv[argc++] = name;
447 	argv[argc] = NULL;
448 
449 	if ((verbose && buf == NULL) || debug) {
450 		(void)printf("exec:");
451 		for (i = 0; i < argc; i++)
452 			(void)printf(" %s", argv[i]);
453 		(void)printf("\n");
454 	}
455 
456 	if (buf) {
457 		if (pipe(pfd) == -1)
458 			warn("Cannot create pipe");
459 	}
460 
461 	switch (pid = vfork()) {
462 	case -1:				/* Error. */
463 		warn("vfork");
464 		if (optbuf)
465 			free(optbuf);
466 		free(argv);
467 		return (1);
468 
469 	case 0:					/* Child. */
470 		if (debug)
471 			_exit(0);
472 
473 		if (buf) {
474 			(void)close(pfd[0]);
475 			(void)close(STDOUT_FILENO);
476 			if (dup2(pfd[1], STDOUT_FILENO) == -1)
477 				warn("Cannot open fd to mount program");
478 		}
479 
480 		/* Go find an executable. */
481 		edir = edirs;
482 		do {
483 			(void)snprintf(execname,
484 			    sizeof(execname), "%s/%s", *edir, execbase);
485 			(void)execv(execname, __UNCONST(argv));
486 			if (errno != ENOENT)
487 				warn("exec %s for %s", execname, name);
488 		} while (*++edir != NULL);
489 
490 		if (errno == ENOENT)
491 			warnx("%s not found for %s", execbase, name);
492 		_exit(1);
493 		/* NOTREACHED */
494 
495 	default:				/* Parent. */
496 		if (optbuf)
497 			free(optbuf);
498 		free(argv);
499 
500 		if (buf || getargs) {
501 			char tbuf[1024], *ptr;
502 			int nread;
503 
504 			if (buf == NULL) {
505 				ptr = tbuf;
506 				buflen = sizeof(tbuf) - 1;
507 			} else {
508 				ptr = buf;
509 				buflen--;
510 			}
511 			(void)close(pfd[1]);
512 			(void)signal(SIGPIPE, SIG_IGN);
513 			while ((nread = read(pfd[0], ptr, buflen)) > 0) {
514 				buflen -= nread;
515 				ptr += nread;
516 			}
517 			*ptr = '\0';
518 			if (buflen == 0) {
519 				while (read(pfd[0], &nread, sizeof(nread)) > 0)
520 					continue;
521 			}
522 			if (buf == NULL)
523 				(void)fprintf(stdout, "%s", tbuf);
524 		}
525 
526 		if (waitpid(pid, &status, 0) < 0) {
527 			warn("waitpid");
528 			return (1);
529 		}
530 
531 		if (WIFEXITED(status)) {
532 			if (WEXITSTATUS(status) != 0)
533 				return (WEXITSTATUS(status));
534 		} else if (WIFSIGNALED(status)) {
535 			warnx("%s: %s", name, strsignal(WTERMSIG(status)));
536 			return (1);
537 		}
538 
539 		if (buf == NULL) {
540 			if (verbose) {
541 				if (statvfs(name, &sf) < 0) {
542 					warn("statvfs %s", name);
543 					return (1);
544 				}
545 				prmount(&sf);
546 			}
547 		}
548 		break;
549 	}
550 
551 	return (0);
552 }
553 
554 static void
555 prmount(struct statvfs *sfp)
556 {
557 	int flags;
558 	const struct opt *o;
559 	struct passwd *pw;
560 	int f;
561 
562 	(void)printf("%s on %s type %.*s", sfp->f_mntfromname,
563 	    sfp->f_mntonname, (int)sizeof(sfp->f_fstypename),
564 	    sfp->f_fstypename);
565 
566 	flags = sfp->f_flag & MNT_VISFLAGMASK;
567 	for (f = 0, o = optnames; flags && o <
568 	    &optnames[sizeof(optnames)/sizeof(optnames[0])]; o++)
569 		if (flags & o->o_opt) {
570 			if (!o->o_silent || verbose)
571 				(void)printf("%s%s", !f++ ? " (" : ", ",
572 				    o->o_name);
573 			flags &= ~o->o_opt;
574 		}
575 	if (flags)
576 		(void)printf("%sunknown flag%s %#x", !f++ ? " (" : ", ",
577 		    flags & (flags - 1) ? "s" : "", flags);
578 	if (sfp->f_owner) {
579 		(void)printf("%smounted by ", !f++ ? " (" : ", ");
580 		if ((pw = getpwuid(sfp->f_owner)) != NULL)
581 			(void)printf("%s", pw->pw_name);
582 		else
583 			(void)printf("%d", sfp->f_owner);
584 	}
585 	if (verbose)
586 		(void)printf("%sfsid: 0x%x/0x%x",
587 		    !f++ ? " (" /* ) */: ", ",
588 		    sfp->f_fsidx.__fsid_val[0], sfp->f_fsidx.__fsid_val[1]);
589 
590 	if (verbose) {
591 		(void)printf("%s", !f++ ? " (" : ", ");
592 		(void)printf("reads: sync %" PRIu64 " async %" PRIu64 "",
593 		    sfp->f_syncreads, sfp->f_asyncreads);
594 		(void)printf(", writes: sync %" PRIu64 " async %" PRIu64 "",
595 		    sfp->f_syncwrites, sfp->f_asyncwrites);
596 		if (verbose > 1) {
597 			char buf[2048];
598 
599 			if (getmntargs(sfp, buf, sizeof(buf)))
600 				printf(", [%s: %s]", sfp->f_fstypename, buf);
601 		}
602 		printf(")\n");
603 	} else
604 		(void)printf("%s", f ? ")\n" : "\n");
605 }
606 
607 static int
608 getmntargs(struct statvfs *sfs, char *buf, size_t buflen)
609 {
610 
611 	if (mountfs(sfs->f_fstypename, sfs->f_mntfromname, sfs->f_mntonname, 0,
612 	    "getargs", NULL, 0, buf, buflen))
613 		return (0);
614 	else {
615 		if (*buf == '\0')
616 			return (0);
617 		if ((buf = strchr(buf, '\n')) != NULL)
618 			*buf = '\0';
619 		return (1);
620 	}
621 }
622 
623 static struct statvfs *
624 getmntpt(const char *name)
625 {
626 	struct statvfs *mntbuf;
627 	int i, mntsize;
628 
629 	mntsize = getmntinfo(&mntbuf, MNT_NOWAIT);
630 	for (i = 0; i < mntsize; i++)
631 		if (strcmp(mntbuf[i].f_mntfromname, name) == 0 ||
632 		    strcmp(mntbuf[i].f_mntonname, name) == 0)
633 			return (&mntbuf[i]);
634 	return (NULL);
635 }
636 
637 static void
638 catopt(char **sp, const char *o)
639 {
640 	char *s, *n;
641 
642 	s = *sp;
643 	if (s) {
644 		if (asprintf(&n, "%s,%s", s, o) < 0)
645 			err(1, "asprintf");
646 		free(s);
647 		s = n;
648 	} else
649 		s = strdup(o);
650 	*sp = s;
651 }
652 
653 static void
654 mangle(char *options, int *argcp, const char ** volatile *argvp, int *maxargcp)
655 {
656 	char *p, *s;
657 	int argc, maxargc;
658 	const char **argv, **nargv;
659 
660 	argc = *argcp;
661 	argv = *argvp;
662 	maxargc = *maxargcp;
663 
664 	for (s = options; (p = strsep(&s, ",")) != NULL;) {
665 		/* Always leave space for one more argument and the NULL. */
666 		if (argc >= maxargc - 4) {
667 			nargv = realloc(argv, (maxargc << 1) * sizeof(char *));
668 			if (!nargv)
669 				err(1, "realloc");
670 			argv = nargv;
671 			maxargc <<= 1;
672 		}
673 		if (*p != '\0') {
674 			if (*p == '-') {
675 				argv[argc++] = p;
676 				p = strchr(p, '=');
677 				if (p) {
678 					*p = '\0';
679 					argv[argc++] = p+1;
680 				}
681 			} else if (strcmp(p, "rw") != 0) {
682 				argv[argc++] = "-o";
683 				argv[argc++] = p;
684 			}
685 		}
686 	}
687 
688 	*argcp = argc;
689 	*argvp = argv;
690 	*maxargcp = maxargc;
691 }
692 
693 /* Deduce the filesystem type from the disk label. */
694 static const char *
695 getfslab(const char *str)
696 {
697 	static struct dkwedge_info dkw;
698 	struct disklabel dl;
699 	int fd;
700 	int part;
701 	const char *vfstype;
702 	u_char fstype;
703 	char buf[MAXPATHLEN + 1];
704 	char *sp, *ep;
705 
706 	if ((fd = open(str, O_RDONLY)) == -1) {
707 		/*
708 		 * Iff we get EBUSY try the raw device. Since mount always uses
709 		 * the block device we know we are never passed a raw device.
710 		 */
711 		if (errno != EBUSY)
712 			err(1, "cannot open `%s'", str);
713 		strlcpy(buf, str, MAXPATHLEN);
714 		if ((sp = strrchr(buf, '/')) != NULL)
715 			++sp;
716 		else
717 			sp = buf;
718 		for (ep = sp + strlen(sp) + 1;  ep > sp; ep--)
719 			*ep = *(ep - 1);
720 		*sp = 'r';
721 
722 		/* Silently fail here - mount call can display error */
723 		if ((fd = open(buf, O_RDONLY)) == -1)
724 			return (NULL);
725 	}
726 
727 	/* Check to see if this is a wedge. */
728 	if (ioctl(fd, DIOCGWEDGEINFO, &dkw) == 0) {
729 		/* Yup, this is easy. */
730 		(void) close(fd);
731 		return (dkw.dkw_ptype);
732 	}
733 
734 	if (ioctl(fd, DIOCGDINFO, &dl) == -1) {
735 		(void) close(fd);
736 		return (NULL);
737 	}
738 
739 	(void) close(fd);
740 
741 	part = str[strlen(str) - 1] - 'a';
742 
743 	if (part < 0 || part >= dl.d_npartitions)
744 		return (NULL);
745 
746 	/* Return NULL for unknown types - caller can fall back to ffs */
747 	if ((fstype = dl.d_partitions[part].p_fstype) >= FSMAXMOUNTNAMES)
748 		vfstype = NULL;
749 	else
750 		vfstype = mountnames[fstype];
751 
752 	return (vfstype);
753 }
754 
755 static void
756 usage(void)
757 {
758 
759 	(void)fprintf(stderr,
760 	    "usage: mount %s\n       mount %s\n       mount %s\n",
761 	    "[-Aadfruvw] [-t type]",
762 	    "[-dfruvw] special | node",
763 	    "[-dfruvw] [-o options] [-t type] special node");
764 	exit(1);
765 	/* NOTREACHED */
766 }
767