xref: /freebsd/bin/df/df.c (revision d6b92ffa) 
1 /*-
2  * Copyright (c) 1980, 1990, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  * (c) UNIX System Laboratories, Inc.
5  * All or some portions of this file are derived from material licensed
6  * to the University of California by American Telephone and Telegraph
7  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
8  * the permission of UNIX System Laboratories, Inc.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #if 0
36 #ifndef lint
37 static const char copyright[] =
38 "@(#) Copyright (c) 1980, 1990, 1993, 1994\n\
39 	The Regents of the University of California.  All rights reserved.\n";
40 #endif /* not lint */
41 
42 #ifndef lint
43 static char sccsid[] = "@(#)df.c	8.9 (Berkeley) 5/8/95";
44 #endif /* not lint */
45 #endif
46 #include <sys/cdefs.h>
47 __FBSDID("$FreeBSD$");
48 
49 #include <sys/param.h>
50 #include <sys/stat.h>
51 #include <sys/mount.h>
52 #include <sys/sysctl.h>
53 #ifdef MOUNT_CHAR_DEVS
54 #include <ufs/ufs/ufsmount.h>
55 #endif
56 #include <err.h>
57 #include <libutil.h>
58 #include <locale.h>
59 #ifdef MOUNT_CHAR_DEVS
60 #include <mntopts.h>
61 #endif
62 #include <stdint.h>
63 #include <stdio.h>
64 #include <stdlib.h>
65 #include <string.h>
66 #include <sysexits.h>
67 #include <unistd.h>
68 #include <libxo/xo.h>
69 
70 #include "extern.h"
71 
72 #define UNITS_SI	1
73 #define UNITS_2		2
74 
75 /* Maximum widths of various fields. */
76 struct maxwidths {
77 	int	mntfrom;
78 	int	fstype;
79 	int	total;
80 	int	used;
81 	int	avail;
82 	int	iused;
83 	int	ifree;
84 };
85 
86 static void	  addstat(struct statfs *, struct statfs *);
87 static char	 *getmntpt(const char *);
88 static int	  int64width(int64_t);
89 static char	 *makenetvfslist(void);
90 static void	  prthuman(const struct statfs *, int64_t);
91 static void	  prthumanval(const char *, int64_t);
92 static intmax_t	  fsbtoblk(int64_t, uint64_t, u_long);
93 static void	  prtstat(struct statfs *, struct maxwidths *);
94 static size_t	  regetmntinfo(struct statfs **, long, const char **);
95 static void	  update_maxwidths(struct maxwidths *, const struct statfs *);
96 static void	  usage(void);
97 
98 static __inline int
99 imax(int a, int b)
100 {
101 	return (a > b ? a : b);
102 }
103 
104 static int	aflag = 0, cflag, hflag, iflag, kflag, lflag = 0, nflag, Tflag;
105 static int	thousands;
106 #ifdef MOUNT_CHAR_DEVS
107 static struct	ufs_args mdev;
108 #endif
109 
110 int
111 main(int argc, char *argv[])
112 {
113 	struct stat stbuf;
114 	struct statfs statfsbuf, totalbuf;
115 	struct maxwidths maxwidths;
116 	struct statfs *mntbuf;
117 #ifdef MOUNT_CHAR_DEVS
118 	struct iovec *iov = NULL;
119 #endif
120 	const char *fstype;
121 #ifdef MOUNT_CHAR_DEVS
122 	char *mntpath;
123 	char errmsg[255] = {0};
124 #endif
125 	char *mntpt;
126 	const char **vfslist;
127 	int i, mntsize;
128 	int ch, rv;
129 #ifdef MOUNT_CHAR_DEVS
130 	int iovlen = 0;
131 #endif
132 
133 	fstype = "ufs";
134 	(void)setlocale(LC_ALL, "");
135 	memset(&maxwidths, 0, sizeof(maxwidths));
136 	memset(&totalbuf, 0, sizeof(totalbuf));
137 	totalbuf.f_bsize = DEV_BSIZE;
138 	strlcpy(totalbuf.f_mntfromname, "total", MNAMELEN);
139 	vfslist = NULL;
140 
141 	argc = xo_parse_args(argc, argv);
142 	if (argc < 0)
143 		exit(1);
144 
145 	while ((ch = getopt(argc, argv, "abcgHhiklmnPt:T,")) != -1)
146 		switch (ch) {
147 		case 'a':
148 			aflag = 1;
149 			break;
150 		case 'b':
151 				/* FALLTHROUGH */
152 		case 'P':
153 			/*
154 			 * POSIX specifically discusses the behavior of
155 			 * both -k and -P. It states that the blocksize should
156 			 * be set to 1024. Thus, if this occurs, simply break
157 			 * rather than clobbering the old blocksize.
158 			 */
159 			if (kflag)
160 				break;
161 			setenv("BLOCKSIZE", "512", 1);
162 			hflag = 0;
163 			break;
164 		case 'c':
165 			cflag = 1;
166 			break;
167 		case 'g':
168 			setenv("BLOCKSIZE", "1g", 1);
169 			hflag = 0;
170 			break;
171 		case 'H':
172 			hflag = UNITS_SI;
173 			break;
174 		case 'h':
175 			hflag = UNITS_2;
176 			break;
177 		case 'i':
178 			iflag = 1;
179 			break;
180 		case 'k':
181 			kflag++;
182 			setenv("BLOCKSIZE", "1024", 1);
183 			hflag = 0;
184 			break;
185 		case 'l':
186 			/* Ignore duplicate -l */
187 			if (lflag)
188 				break;
189 			if (vfslist != NULL)
190 				xo_errx(1, "-l and -t are mutually exclusive.");
191 			vfslist = makevfslist(makenetvfslist());
192 			lflag = 1;
193 			break;
194 		case 'm':
195 			setenv("BLOCKSIZE", "1m", 1);
196 			hflag = 0;
197 			break;
198 		case 'n':
199 			nflag = 1;
200 			break;
201 		case 't':
202 			if (lflag)
203 				xo_errx(1, "-l and -t are mutually exclusive.");
204 			if (vfslist != NULL)
205 				xo_errx(1, "only one -t option may be specified");
206 			fstype = optarg;
207 			vfslist = makevfslist(optarg);
208 			break;
209 		case 'T':
210 			Tflag = 1;
211 			break;
212 		case ',':
213 			thousands = 1;
214 			break;
215 		case '?':
216 		default:
217 			usage();
218 		}
219 	argc -= optind;
220 	argv += optind;
221 
222 	rv = 0;
223 	if (!*argv) {
224 		/* everything (modulo -t) */
225 		mntsize = getmntinfo(&mntbuf, MNT_NOWAIT);
226 		mntsize = regetmntinfo(&mntbuf, mntsize, vfslist);
227 	} else {
228 		/* just the filesystems specified on the command line */
229 		mntbuf = malloc(argc * sizeof(*mntbuf));
230 		if (mntbuf == NULL)
231 			xo_err(1, "malloc()");
232 		mntsize = 0;
233 		/* continued in for loop below */
234 	}
235 
236 	xo_open_container("storage-system-information");
237 	xo_open_list("filesystem");
238 
239 	/* iterate through specified filesystems */
240 	for (; *argv; argv++) {
241 		if (stat(*argv, &stbuf) < 0) {
242 			if ((mntpt = getmntpt(*argv)) == NULL) {
243 				xo_warn("%s", *argv);
244 				rv = 1;
245 				continue;
246 			}
247 #ifdef MOUNT_CHAR_DEVS
248 		} else if (S_ISCHR(stbuf.st_mode)) {
249 			if ((mntpt = getmntpt(*argv)) == NULL) {
250 				mdev.fspec = *argv;
251 				mntpath = strdup("/tmp/df.XXXXXX");
252 				if (mntpath == NULL) {
253 					xo_warn("strdup failed");
254 					rv = 1;
255 					continue;
256 				}
257 				mntpt = mkdtemp(mntpath);
258 				if (mntpt == NULL) {
259 					xo_warn("mkdtemp(\"%s\") failed", mntpath);
260 					rv = 1;
261 					free(mntpath);
262 					continue;
263 				}
264 				if (iov != NULL)
265 					free_iovec(&iov, &iovlen);
266 				build_iovec_argf(&iov, &iovlen, "fstype", "%s",
267 				    fstype);
268 				build_iovec_argf(&iov, &iovlen, "fspath", "%s",
269 				    mntpath);
270 				build_iovec_argf(&iov, &iovlen, "from", "%s",
271 				    *argv);
272 				build_iovec(&iov, &iovlen, "errmsg", errmsg,
273 				    sizeof(errmsg));
274 				if (nmount(iov, iovlen,
275 				    MNT_RDONLY|MNT_NOEXEC) < 0) {
276 					if (errmsg[0])
277 						xo_warn("%s: %s", *argv,
278 						    errmsg);
279 					else
280 						xo_warn("%s", *argv);
281 					rv = 1;
282 					(void)rmdir(mntpt);
283 					free(mntpath);
284 					continue;
285 				} else if (statfs(mntpt, &statfsbuf) == 0) {
286 					statfsbuf.f_mntonname[0] = '\0';
287 					prtstat(&statfsbuf, &maxwidths);
288 					if (cflag)
289 						addstat(&totalbuf, &statfsbuf);
290 				} else {
291 					xo_warn("%s", *argv);
292 					rv = 1;
293 				}
294 				(void)unmount(mntpt, 0);
295 				(void)rmdir(mntpt);
296 				free(mntpath);
297 				continue;
298 			}
299 #endif
300 		} else
301 			mntpt = *argv;
302 
303 		/*
304 		 * Statfs does not take a `wait' flag, so we cannot
305 		 * implement nflag here.
306 		 */
307 		if (statfs(mntpt, &statfsbuf) < 0) {
308 			xo_warn("%s", mntpt);
309 			rv = 1;
310 			continue;
311 		}
312 
313 		/*
314 		 * Check to make sure the arguments we've been given are
315 		 * satisfied.  Return an error if we have been asked to
316 		 * list a mount point that does not match the other args
317 		 * we've been given (-l, -t, etc.).
318 		 */
319 		if (checkvfsname(statfsbuf.f_fstypename, vfslist)) {
320 			rv = 1;
321 			continue;
322 		}
323 
324 		/* the user asked for it, so ignore the ignore flag */
325 		statfsbuf.f_flags &= ~MNT_IGNORE;
326 
327 		/* add to list */
328 		mntbuf[mntsize++] = statfsbuf;
329 	}
330 
331 	memset(&maxwidths, 0, sizeof(maxwidths));
332 	for (i = 0; i < mntsize; i++) {
333 		if (aflag || (mntbuf[i].f_flags & MNT_IGNORE) == 0) {
334 			update_maxwidths(&maxwidths, &mntbuf[i]);
335 			if (cflag)
336 				addstat(&totalbuf, &mntbuf[i]);
337 		}
338 	}
339 	for (i = 0; i < mntsize; i++)
340 		if (aflag || (mntbuf[i].f_flags & MNT_IGNORE) == 0)
341 			prtstat(&mntbuf[i], &maxwidths);
342 
343 	xo_close_list("filesystem");
344 
345 	if (cflag)
346 		prtstat(&totalbuf, &maxwidths);
347 
348 	xo_close_container("storage-system-information");
349 	xo_finish();
350 	exit(rv);
351 }
352 
353 static char *
354 getmntpt(const char *name)
355 {
356 	size_t mntsize, i;
357 	struct statfs *mntbuf;
358 
359 	mntsize = getmntinfo(&mntbuf, MNT_NOWAIT);
360 	for (i = 0; i < mntsize; i++) {
361 		if (!strcmp(mntbuf[i].f_mntfromname, name))
362 			return (mntbuf[i].f_mntonname);
363 	}
364 	return (NULL);
365 }
366 
367 /*
368  * Make a pass over the file system info in ``mntbuf'' filtering out
369  * file system types not in vfslist and possibly re-stating to get
370  * current (not cached) info.  Returns the new count of valid statfs bufs.
371  */
372 static size_t
373 regetmntinfo(struct statfs **mntbufp, long mntsize, const char **vfslist)
374 {
375 	int error, i, j;
376 	struct statfs *mntbuf;
377 
378 	if (vfslist == NULL)
379 		return (nflag ? mntsize : getmntinfo(mntbufp, MNT_WAIT));
380 
381 	mntbuf = *mntbufp;
382 	for (j = 0, i = 0; i < mntsize; i++) {
383 		if (checkvfsname(mntbuf[i].f_fstypename, vfslist))
384 			continue;
385 		/*
386 		 * XXX statfs(2) can fail for various reasons. It may be
387 		 * possible that the user does not have access to the
388 		 * pathname, if this happens, we will fall back on
389 		 * "stale" filesystem statistics.
390 		 */
391 		error = statfs(mntbuf[i].f_mntonname, &mntbuf[j]);
392 		if (nflag || error < 0)
393 			if (i != j) {
394 				if (error < 0)
395 					xo_warnx("%s stats possibly stale",
396 					    mntbuf[i].f_mntonname);
397 				mntbuf[j] = mntbuf[i];
398 			}
399 		j++;
400 	}
401 	return (j);
402 }
403 
404 static void
405 prthuman(const struct statfs *sfsp, int64_t used)
406 {
407 
408 	prthumanval("  {:blocks/%6s}", sfsp->f_blocks * sfsp->f_bsize);
409 	prthumanval("  {:used/%6s}", used * sfsp->f_bsize);
410 	prthumanval("  {:available/%6s}", sfsp->f_bavail * sfsp->f_bsize);
411 }
412 
413 static void
414 prthumanval(const char *fmt, int64_t bytes)
415 {
416 	char buf[6];
417 	int flags;
418 
419 	flags = HN_B | HN_NOSPACE | HN_DECIMAL;
420 	if (hflag == UNITS_SI)
421 		flags |= HN_DIVISOR_1000;
422 
423 	humanize_number(buf, sizeof(buf) - (bytes < 0 ? 0 : 1),
424 	    bytes, "", HN_AUTOSCALE, flags);
425 
426 	xo_attr("value", "%lld", (long long) bytes);
427 	xo_emit(fmt, buf);
428 }
429 
430 /*
431  * Print an inode count in "human-readable" format.
432  */
433 static void
434 prthumanvalinode(const char *fmt, int64_t bytes)
435 {
436 	char buf[6];
437 	int flags;
438 
439 	flags = HN_NOSPACE | HN_DECIMAL | HN_DIVISOR_1000;
440 
441 	humanize_number(buf, sizeof(buf) - (bytes < 0 ? 0 : 1),
442 	    bytes, "", HN_AUTOSCALE, flags);
443 
444 	xo_attr("value", "%lld", (long long) bytes);
445 	xo_emit(fmt, buf);
446 }
447 
448 /*
449  * Convert statfs returned file system size into BLOCKSIZE units.
450  */
451 static intmax_t
452 fsbtoblk(int64_t num, uint64_t fsbs, u_long bs)
453 {
454 	return (num * (intmax_t) fsbs / (int64_t) bs);
455 }
456 
457 /*
458  * Print out status about a file system.
459  */
460 static void
461 prtstat(struct statfs *sfsp, struct maxwidths *mwp)
462 {
463 	static long blocksize;
464 	static int headerlen, timesthrough = 0;
465 	static const char *header;
466 	int64_t used, availblks, inodes;
467 	const char *format;
468 
469 	if (++timesthrough == 1) {
470 		mwp->mntfrom = imax(mwp->mntfrom, (int)strlen("Filesystem"));
471 		mwp->fstype = imax(mwp->fstype, (int)strlen("Type"));
472 		if (thousands) {		/* make space for commas */
473 		    mwp->total += (mwp->total - 1) / 3;
474 		    mwp->used  += (mwp->used - 1) / 3;
475 		    mwp->avail += (mwp->avail - 1) / 3;
476 		    mwp->iused += (mwp->iused - 1) / 3;
477 		    mwp->ifree += (mwp->ifree - 1) / 3;
478 		}
479 		if (hflag) {
480 			header = "   Size";
481 			mwp->total = mwp->used = mwp->avail =
482 			    (int)strlen(header);
483 		} else {
484 			header = getbsize(&headerlen, &blocksize);
485 			mwp->total = imax(mwp->total, headerlen);
486 		}
487 		mwp->used = imax(mwp->used, (int)strlen("Used"));
488 		mwp->avail = imax(mwp->avail, (int)strlen("Avail"));
489 
490 		xo_emit("{T:/%-*s}", mwp->mntfrom, "Filesystem");
491 		if (Tflag)
492 			xo_emit("  {T:/%-*s}", mwp->fstype, "Type");
493 		xo_emit(" {T:/%*s} {T:/%*s} {T:/%*s} {T:Capacity}",
494 			mwp->total, header,
495 			mwp->used, "Used", mwp->avail, "Avail");
496 		if (iflag) {
497 			mwp->iused = imax(hflag ? 0 : mwp->iused,
498 			    (int)strlen("  iused"));
499 			mwp->ifree = imax(hflag ? 0 : mwp->ifree,
500 			    (int)strlen("ifree"));
501 			xo_emit(" {T:/%*s} {T:/%*s} {T:\%iused}",
502 			    mwp->iused - 2, "iused", mwp->ifree, "ifree");
503 		}
504 		xo_emit("  {T:Mounted on}\n");
505 	}
506 
507 	xo_open_instance("filesystem");
508 	/* Check for 0 block size.  Can this happen? */
509 	if (sfsp->f_bsize == 0) {
510 		xo_warnx ("File system %s does not have a block size, assuming 512.",
511 		    sfsp->f_mntonname);
512 		sfsp->f_bsize = 512;
513 	}
514 	xo_emit("{tk:name/%-*s}", mwp->mntfrom, sfsp->f_mntfromname);
515 	if (Tflag)
516 		xo_emit("  {:type/%-*s}", mwp->fstype, sfsp->f_fstypename);
517 	used = sfsp->f_blocks - sfsp->f_bfree;
518 	availblks = sfsp->f_bavail + used;
519 	if (hflag) {
520 		prthuman(sfsp, used);
521 	} else {
522 		if (thousands)
523 		    format = " {t:total-blocks/%*j'd} {t:used-blocks/%*j'd} "
524 			"{t:available-blocks/%*j'd}";
525 		else
526 		    format = " {t:total-blocks/%*jd} {t:used-blocks/%*jd} "
527 			"{t:available-blocks/%*jd}";
528 		xo_emit(format,
529 		    mwp->total, fsbtoblk(sfsp->f_blocks,
530 		    sfsp->f_bsize, blocksize),
531 		    mwp->used, fsbtoblk(used, sfsp->f_bsize, blocksize),
532 		    mwp->avail, fsbtoblk(sfsp->f_bavail,
533 		    sfsp->f_bsize, blocksize));
534 	}
535 	xo_emit(" {:used-percent/%5.0f}{U:%%}",
536 	    availblks == 0 ? 100.0 : (double)used / (double)availblks * 100.0);
537 	if (iflag) {
538 		inodes = sfsp->f_files;
539 		used = inodes - sfsp->f_ffree;
540 		if (hflag) {
541 			xo_emit("  ");
542 			prthumanvalinode(" {:inodes-used/%5s}", used);
543 			prthumanvalinode(" {:inodes-free/%5s}", sfsp->f_ffree);
544 		} else {
545 			if (thousands)
546 			    format = " {:inodes-used/%*j'd} {:inodes-free/%*j'd}";
547 			else
548 			    format = " {:inodes-used/%*jd} {:inodes-free/%*jd}";
549 			xo_emit(format, mwp->iused, (intmax_t)used,
550 			    mwp->ifree, (intmax_t)sfsp->f_ffree);
551 		}
552 		xo_emit(" {:inodes-used-percent/%4.0f}{U:%%} ",
553 			inodes == 0 ? 100.0 :
554 			(double)used / (double)inodes * 100.0);
555 	} else
556 		xo_emit("  ");
557 	if (strncmp(sfsp->f_mntfromname, "total", MNAMELEN) != 0)
558 		xo_emit("  {:mounted-on}", sfsp->f_mntonname);
559 	xo_emit("\n");
560 	xo_close_instance("filesystem");
561 }
562 
563 static void
564 addstat(struct statfs *totalfsp, struct statfs *statfsp)
565 {
566 	uint64_t bsize;
567 
568 	bsize = statfsp->f_bsize / totalfsp->f_bsize;
569 	totalfsp->f_blocks += statfsp->f_blocks * bsize;
570 	totalfsp->f_bfree += statfsp->f_bfree * bsize;
571 	totalfsp->f_bavail += statfsp->f_bavail * bsize;
572 	totalfsp->f_files += statfsp->f_files;
573 	totalfsp->f_ffree += statfsp->f_ffree;
574 }
575 
576 /*
577  * Update the maximum field-width information in `mwp' based on
578  * the file system specified by `sfsp'.
579  */
580 static void
581 update_maxwidths(struct maxwidths *mwp, const struct statfs *sfsp)
582 {
583 	static long blocksize = 0;
584 	int dummy;
585 
586 	if (blocksize == 0)
587 		getbsize(&dummy, &blocksize);
588 
589 	mwp->mntfrom = imax(mwp->mntfrom, (int)strlen(sfsp->f_mntfromname));
590 	mwp->fstype = imax(mwp->fstype, (int)strlen(sfsp->f_fstypename));
591 	mwp->total = imax(mwp->total, int64width(
592 	    fsbtoblk((int64_t)sfsp->f_blocks, sfsp->f_bsize, blocksize)));
593 	mwp->used = imax(mwp->used,
594 	    int64width(fsbtoblk((int64_t)sfsp->f_blocks -
595 	    (int64_t)sfsp->f_bfree, sfsp->f_bsize, blocksize)));
596 	mwp->avail = imax(mwp->avail, int64width(fsbtoblk(sfsp->f_bavail,
597 	    sfsp->f_bsize, blocksize)));
598 	mwp->iused = imax(mwp->iused, int64width((int64_t)sfsp->f_files -
599 	    sfsp->f_ffree));
600 	mwp->ifree = imax(mwp->ifree, int64width(sfsp->f_ffree));
601 }
602 
603 /* Return the width in characters of the specified value. */
604 static int
605 int64width(int64_t val)
606 {
607 	int len;
608 
609 	len = 0;
610 	/* Negative or zero values require one extra digit. */
611 	if (val <= 0) {
612 		val = -val;
613 		len++;
614 	}
615 	while (val > 0) {
616 		len++;
617 		val /= 10;
618 	}
619 
620 	return (len);
621 }
622 
623 static void
624 usage(void)
625 {
626 
627 	xo_error(
628 "usage: df [-b | -g | -H | -h | -k | -m | -P] [-acilnT] [-t type] [-,]\n"
629 "          [file | filesystem ...]\n");
630 	exit(EX_USAGE);
631 }
632 
633 static char *
634 makenetvfslist(void)
635 {
636 	char *str, *strptr, **listptr;
637 	struct xvfsconf *xvfsp, *keep_xvfsp;
638 	size_t buflen;
639 	int cnt, i, maxvfsconf;
640 
641 	if (sysctlbyname("vfs.conflist", NULL, &buflen, NULL, 0) < 0) {
642 		xo_warn("sysctl(vfs.conflist)");
643 		return (NULL);
644 	}
645 	xvfsp = malloc(buflen);
646 	if (xvfsp == NULL) {
647 		xo_warnx("malloc failed");
648 		return (NULL);
649 	}
650 	keep_xvfsp = xvfsp;
651 	if (sysctlbyname("vfs.conflist", xvfsp, &buflen, NULL, 0) < 0) {
652 		xo_warn("sysctl(vfs.conflist)");
653 		free(keep_xvfsp);
654 		return (NULL);
655 	}
656 	maxvfsconf = buflen / sizeof(struct xvfsconf);
657 
658 	if ((listptr = malloc(sizeof(char*) * maxvfsconf)) == NULL) {
659 		xo_warnx("malloc failed");
660 		free(keep_xvfsp);
661 		return (NULL);
662 	}
663 
664 	for (cnt = 0, i = 0; i < maxvfsconf; i++) {
665 		if (xvfsp->vfc_flags & VFCF_NETWORK) {
666 			listptr[cnt++] = strdup(xvfsp->vfc_name);
667 			if (listptr[cnt-1] == NULL) {
668 				xo_warnx("malloc failed");
669 				free(listptr);
670 				free(keep_xvfsp);
671 				return (NULL);
672 			}
673 		}
674 		xvfsp++;
675 	}
676 
677 	if (cnt == 0 ||
678 	    (str = malloc(sizeof(char) * (32 * cnt + cnt + 2))) == NULL) {
679 		if (cnt > 0)
680 			xo_warnx("malloc failed");
681 		free(listptr);
682 		free(keep_xvfsp);
683 		return (NULL);
684 	}
685 
686 	*str = 'n'; *(str + 1) = 'o';
687 	for (i = 0, strptr = str + 2; i < cnt; i++, strptr++) {
688 		strlcpy(strptr, listptr[i], 32);
689 		strptr += strlen(listptr[i]);
690 		*strptr = ',';
691 		free(listptr[i]);
692 	}
693 	*(--strptr) = '\0';
694 
695 	free(keep_xvfsp);
696 	free(listptr);
697 	return (str);
698 }
699