xref: /freebsd/sys/kern/vfs_syscalls.c (revision 0957b409)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  * (c) UNIX System Laboratories, Inc.
7  * All or some portions of this file are derived from material licensed
8  * to the University of California by American Telephone and Telegraph
9  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
10  * the permission of UNIX System Laboratories, Inc.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  *
36  *	@(#)vfs_syscalls.c	8.13 (Berkeley) 4/15/94
37  */
38 
39 #include <sys/cdefs.h>
40 __FBSDID("$FreeBSD$");
41 
42 #include "opt_capsicum.h"
43 #include "opt_ktrace.h"
44 
45 #include <sys/param.h>
46 #include <sys/systm.h>
47 #include <sys/bio.h>
48 #include <sys/buf.h>
49 #include <sys/capsicum.h>
50 #include <sys/disk.h>
51 #include <sys/sysent.h>
52 #include <sys/malloc.h>
53 #include <sys/mount.h>
54 #include <sys/mutex.h>
55 #include <sys/sysproto.h>
56 #include <sys/namei.h>
57 #include <sys/filedesc.h>
58 #include <sys/kernel.h>
59 #include <sys/fcntl.h>
60 #include <sys/file.h>
61 #include <sys/filio.h>
62 #include <sys/limits.h>
63 #include <sys/linker.h>
64 #include <sys/rwlock.h>
65 #include <sys/sdt.h>
66 #include <sys/stat.h>
67 #include <sys/sx.h>
68 #include <sys/unistd.h>
69 #include <sys/vnode.h>
70 #include <sys/priv.h>
71 #include <sys/proc.h>
72 #include <sys/dirent.h>
73 #include <sys/jail.h>
74 #include <sys/syscallsubr.h>
75 #include <sys/sysctl.h>
76 #ifdef KTRACE
77 #include <sys/ktrace.h>
78 #endif
79 
80 #include <machine/stdarg.h>
81 
82 #include <security/audit/audit.h>
83 #include <security/mac/mac_framework.h>
84 
85 #include <vm/vm.h>
86 #include <vm/vm_object.h>
87 #include <vm/vm_page.h>
88 #include <vm/uma.h>
89 
90 #include <ufs/ufs/quota.h>
91 
92 MALLOC_DEFINE(M_FADVISE, "fadvise", "posix_fadvise(2) information");
93 
94 SDT_PROVIDER_DEFINE(vfs);
95 SDT_PROBE_DEFINE2(vfs, , stat, mode, "char *", "int");
96 SDT_PROBE_DEFINE2(vfs, , stat, reg, "char *", "int");
97 
98 static int kern_chflagsat(struct thread *td, int fd, const char *path,
99     enum uio_seg pathseg, u_long flags, int atflag);
100 static int setfflags(struct thread *td, struct vnode *, u_long);
101 static int getutimes(const struct timeval *, enum uio_seg, struct timespec *);
102 static int getutimens(const struct timespec *, enum uio_seg,
103     struct timespec *, int *);
104 static int setutimes(struct thread *td, struct vnode *,
105     const struct timespec *, int, int);
106 static int vn_access(struct vnode *vp, int user_flags, struct ucred *cred,
107     struct thread *td);
108 static int kern_fhlinkat(struct thread *td, int fd, const char *path,
109     enum uio_seg pathseg, fhandle_t *fhp);
110 static int kern_getfhat(struct thread *td, int flags, int fd,
111     const char *path, enum uio_seg pathseg, fhandle_t *fhp);
112 static int kern_readlink_vp(struct vnode *vp, char *buf, enum uio_seg bufseg,
113     size_t count, struct thread *td);
114 static int kern_linkat_vp(struct thread *td, struct vnode *vp, int fd,
115     const char *path, enum uio_seg segflag);
116 
117 /*
118  * Sync each mounted filesystem.
119  */
120 #ifndef _SYS_SYSPROTO_H_
121 struct sync_args {
122 	int     dummy;
123 };
124 #endif
125 /* ARGSUSED */
126 int
127 sys_sync(struct thread *td, struct sync_args *uap)
128 {
129 	struct mount *mp, *nmp;
130 	int save;
131 
132 	mtx_lock(&mountlist_mtx);
133 	for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
134 		if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) {
135 			nmp = TAILQ_NEXT(mp, mnt_list);
136 			continue;
137 		}
138 		if ((mp->mnt_flag & MNT_RDONLY) == 0 &&
139 		    vn_start_write(NULL, &mp, V_NOWAIT) == 0) {
140 			save = curthread_pflags_set(TDP_SYNCIO);
141 			vfs_msync(mp, MNT_NOWAIT);
142 			VFS_SYNC(mp, MNT_NOWAIT);
143 			curthread_pflags_restore(save);
144 			vn_finished_write(mp);
145 		}
146 		mtx_lock(&mountlist_mtx);
147 		nmp = TAILQ_NEXT(mp, mnt_list);
148 		vfs_unbusy(mp);
149 	}
150 	mtx_unlock(&mountlist_mtx);
151 	return (0);
152 }
153 
154 /*
155  * Change filesystem quotas.
156  */
157 #ifndef _SYS_SYSPROTO_H_
158 struct quotactl_args {
159 	char *path;
160 	int cmd;
161 	int uid;
162 	caddr_t arg;
163 };
164 #endif
165 int
166 sys_quotactl(struct thread *td, struct quotactl_args *uap)
167 {
168 	struct mount *mp;
169 	struct nameidata nd;
170 	int error;
171 
172 	AUDIT_ARG_CMD(uap->cmd);
173 	AUDIT_ARG_UID(uap->uid);
174 	if (!prison_allow(td->td_ucred, PR_ALLOW_QUOTAS))
175 		return (EPERM);
176 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, UIO_USERSPACE,
177 	    uap->path, td);
178 	if ((error = namei(&nd)) != 0)
179 		return (error);
180 	NDFREE(&nd, NDF_ONLY_PNBUF);
181 	mp = nd.ni_vp->v_mount;
182 	vfs_ref(mp);
183 	vput(nd.ni_vp);
184 	error = vfs_busy(mp, 0);
185 	vfs_rel(mp);
186 	if (error != 0)
187 		return (error);
188 	error = VFS_QUOTACTL(mp, uap->cmd, uap->uid, uap->arg);
189 
190 	/*
191 	 * Since quota on operation typically needs to open quota
192 	 * file, the Q_QUOTAON handler needs to unbusy the mount point
193 	 * before calling into namei.  Otherwise, unmount might be
194 	 * started between two vfs_busy() invocations (first is our,
195 	 * second is from mount point cross-walk code in lookup()),
196 	 * causing deadlock.
197 	 *
198 	 * Require that Q_QUOTAON handles the vfs_busy() reference on
199 	 * its own, always returning with ubusied mount point.
200 	 */
201 	if ((uap->cmd >> SUBCMDSHIFT) != Q_QUOTAON &&
202 	    (uap->cmd >> SUBCMDSHIFT) != Q_QUOTAOFF)
203 		vfs_unbusy(mp);
204 	return (error);
205 }
206 
207 /*
208  * Used by statfs conversion routines to scale the block size up if
209  * necessary so that all of the block counts are <= 'max_size'.  Note
210  * that 'max_size' should be a bitmask, i.e. 2^n - 1 for some non-zero
211  * value of 'n'.
212  */
213 void
214 statfs_scale_blocks(struct statfs *sf, long max_size)
215 {
216 	uint64_t count;
217 	int shift;
218 
219 	KASSERT(powerof2(max_size + 1), ("%s: invalid max_size", __func__));
220 
221 	/*
222 	 * Attempt to scale the block counts to give a more accurate
223 	 * overview to userland of the ratio of free space to used
224 	 * space.  To do this, find the largest block count and compute
225 	 * a divisor that lets it fit into a signed integer <= max_size.
226 	 */
227 	if (sf->f_bavail < 0)
228 		count = -sf->f_bavail;
229 	else
230 		count = sf->f_bavail;
231 	count = MAX(sf->f_blocks, MAX(sf->f_bfree, count));
232 	if (count <= max_size)
233 		return;
234 
235 	count >>= flsl(max_size);
236 	shift = 0;
237 	while (count > 0) {
238 		shift++;
239 		count >>=1;
240 	}
241 
242 	sf->f_bsize <<= shift;
243 	sf->f_blocks >>= shift;
244 	sf->f_bfree >>= shift;
245 	sf->f_bavail >>= shift;
246 }
247 
248 static int
249 kern_do_statfs(struct thread *td, struct mount *mp, struct statfs *buf)
250 {
251 	struct statfs *sp;
252 	int error;
253 
254 	if (mp == NULL)
255 		return (EBADF);
256 	error = vfs_busy(mp, 0);
257 	vfs_rel(mp);
258 	if (error != 0)
259 		return (error);
260 #ifdef MAC
261 	error = mac_mount_check_stat(td->td_ucred, mp);
262 	if (error != 0)
263 		goto out;
264 #endif
265 	/*
266 	 * Set these in case the underlying filesystem fails to do so.
267 	 */
268 	sp = &mp->mnt_stat;
269 	sp->f_version = STATFS_VERSION;
270 	sp->f_namemax = NAME_MAX;
271 	sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
272 	error = VFS_STATFS(mp, sp);
273 	if (error != 0)
274 		goto out;
275 	*buf = *sp;
276 	if (priv_check(td, PRIV_VFS_GENERATION)) {
277 		buf->f_fsid.val[0] = buf->f_fsid.val[1] = 0;
278 		prison_enforce_statfs(td->td_ucred, mp, buf);
279 	}
280 out:
281 	vfs_unbusy(mp);
282 	return (error);
283 }
284 
285 /*
286  * Get filesystem statistics.
287  */
288 #ifndef _SYS_SYSPROTO_H_
289 struct statfs_args {
290 	char *path;
291 	struct statfs *buf;
292 };
293 #endif
294 int
295 sys_statfs(struct thread *td, struct statfs_args *uap)
296 {
297 	struct statfs *sfp;
298 	int error;
299 
300 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
301 	error = kern_statfs(td, uap->path, UIO_USERSPACE, sfp);
302 	if (error == 0)
303 		error = copyout(sfp, uap->buf, sizeof(struct statfs));
304 	free(sfp, M_STATFS);
305 	return (error);
306 }
307 
308 int
309 kern_statfs(struct thread *td, const char *path, enum uio_seg pathseg,
310     struct statfs *buf)
311 {
312 	struct mount *mp;
313 	struct nameidata nd;
314 	int error;
315 
316 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF | AUDITVNODE1,
317 	    pathseg, path, td);
318 	error = namei(&nd);
319 	if (error != 0)
320 		return (error);
321 	mp = nd.ni_vp->v_mount;
322 	vfs_ref(mp);
323 	NDFREE(&nd, NDF_ONLY_PNBUF);
324 	vput(nd.ni_vp);
325 	return (kern_do_statfs(td, mp, buf));
326 }
327 
328 /*
329  * Get filesystem statistics.
330  */
331 #ifndef _SYS_SYSPROTO_H_
332 struct fstatfs_args {
333 	int fd;
334 	struct statfs *buf;
335 };
336 #endif
337 int
338 sys_fstatfs(struct thread *td, struct fstatfs_args *uap)
339 {
340 	struct statfs *sfp;
341 	int error;
342 
343 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
344 	error = kern_fstatfs(td, uap->fd, sfp);
345 	if (error == 0)
346 		error = copyout(sfp, uap->buf, sizeof(struct statfs));
347 	free(sfp, M_STATFS);
348 	return (error);
349 }
350 
351 int
352 kern_fstatfs(struct thread *td, int fd, struct statfs *buf)
353 {
354 	struct file *fp;
355 	struct mount *mp;
356 	struct vnode *vp;
357 	int error;
358 
359 	AUDIT_ARG_FD(fd);
360 	error = getvnode(td, fd, &cap_fstatfs_rights, &fp);
361 	if (error != 0)
362 		return (error);
363 	vp = fp->f_vnode;
364 	vn_lock(vp, LK_SHARED | LK_RETRY);
365 #ifdef AUDIT
366 	AUDIT_ARG_VNODE1(vp);
367 #endif
368 	mp = vp->v_mount;
369 	if (mp != NULL)
370 		vfs_ref(mp);
371 	VOP_UNLOCK(vp, 0);
372 	fdrop(fp, td);
373 	return (kern_do_statfs(td, mp, buf));
374 }
375 
376 /*
377  * Get statistics on all filesystems.
378  */
379 #ifndef _SYS_SYSPROTO_H_
380 struct getfsstat_args {
381 	struct statfs *buf;
382 	long bufsize;
383 	int mode;
384 };
385 #endif
386 int
387 sys_getfsstat(struct thread *td, struct getfsstat_args *uap)
388 {
389 	size_t count;
390 	int error;
391 
392 	if (uap->bufsize < 0 || uap->bufsize > SIZE_MAX)
393 		return (EINVAL);
394 	error = kern_getfsstat(td, &uap->buf, uap->bufsize, &count,
395 	    UIO_USERSPACE, uap->mode);
396 	if (error == 0)
397 		td->td_retval[0] = count;
398 	return (error);
399 }
400 
401 /*
402  * If (bufsize > 0 && bufseg == UIO_SYSSPACE)
403  *	The caller is responsible for freeing memory which will be allocated
404  *	in '*buf'.
405  */
406 int
407 kern_getfsstat(struct thread *td, struct statfs **buf, size_t bufsize,
408     size_t *countp, enum uio_seg bufseg, int mode)
409 {
410 	struct mount *mp, *nmp;
411 	struct statfs *sfsp, *sp, *sptmp, *tofree;
412 	size_t count, maxcount;
413 	int error;
414 
415 	switch (mode) {
416 	case MNT_WAIT:
417 	case MNT_NOWAIT:
418 		break;
419 	default:
420 		if (bufseg == UIO_SYSSPACE)
421 			*buf = NULL;
422 		return (EINVAL);
423 	}
424 restart:
425 	maxcount = bufsize / sizeof(struct statfs);
426 	if (bufsize == 0) {
427 		sfsp = NULL;
428 		tofree = NULL;
429 	} else if (bufseg == UIO_USERSPACE) {
430 		sfsp = *buf;
431 		tofree = NULL;
432 	} else /* if (bufseg == UIO_SYSSPACE) */ {
433 		count = 0;
434 		mtx_lock(&mountlist_mtx);
435 		TAILQ_FOREACH(mp, &mountlist, mnt_list) {
436 			count++;
437 		}
438 		mtx_unlock(&mountlist_mtx);
439 		if (maxcount > count)
440 			maxcount = count;
441 		tofree = sfsp = *buf = malloc(maxcount * sizeof(struct statfs),
442 		    M_STATFS, M_WAITOK);
443 	}
444 	count = 0;
445 	mtx_lock(&mountlist_mtx);
446 	for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
447 		if (prison_canseemount(td->td_ucred, mp) != 0) {
448 			nmp = TAILQ_NEXT(mp, mnt_list);
449 			continue;
450 		}
451 #ifdef MAC
452 		if (mac_mount_check_stat(td->td_ucred, mp) != 0) {
453 			nmp = TAILQ_NEXT(mp, mnt_list);
454 			continue;
455 		}
456 #endif
457 		if (mode == MNT_WAIT) {
458 			if (vfs_busy(mp, MBF_MNTLSTLOCK) != 0) {
459 				/*
460 				 * If vfs_busy() failed, and MBF_NOWAIT
461 				 * wasn't passed, then the mp is gone.
462 				 * Furthermore, because of MBF_MNTLSTLOCK,
463 				 * the mountlist_mtx was dropped.  We have
464 				 * no other choice than to start over.
465 				 */
466 				mtx_unlock(&mountlist_mtx);
467 				free(tofree, M_STATFS);
468 				goto restart;
469 			}
470 		} else {
471 			if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK) != 0) {
472 				nmp = TAILQ_NEXT(mp, mnt_list);
473 				continue;
474 			}
475 		}
476 		if (sfsp != NULL && count < maxcount) {
477 			sp = &mp->mnt_stat;
478 			/*
479 			 * Set these in case the underlying filesystem
480 			 * fails to do so.
481 			 */
482 			sp->f_version = STATFS_VERSION;
483 			sp->f_namemax = NAME_MAX;
484 			sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
485 			/*
486 			 * If MNT_NOWAIT is specified, do not refresh
487 			 * the fsstat cache.
488 			 */
489 			if (mode != MNT_NOWAIT) {
490 				error = VFS_STATFS(mp, sp);
491 				if (error != 0) {
492 					mtx_lock(&mountlist_mtx);
493 					nmp = TAILQ_NEXT(mp, mnt_list);
494 					vfs_unbusy(mp);
495 					continue;
496 				}
497 			}
498 			if (priv_check(td, PRIV_VFS_GENERATION)) {
499 				sptmp = malloc(sizeof(struct statfs), M_STATFS,
500 				    M_WAITOK);
501 				*sptmp = *sp;
502 				sptmp->f_fsid.val[0] = sptmp->f_fsid.val[1] = 0;
503 				prison_enforce_statfs(td->td_ucred, mp, sptmp);
504 				sp = sptmp;
505 			} else
506 				sptmp = NULL;
507 			if (bufseg == UIO_SYSSPACE) {
508 				bcopy(sp, sfsp, sizeof(*sp));
509 				free(sptmp, M_STATFS);
510 			} else /* if (bufseg == UIO_USERSPACE) */ {
511 				error = copyout(sp, sfsp, sizeof(*sp));
512 				free(sptmp, M_STATFS);
513 				if (error != 0) {
514 					vfs_unbusy(mp);
515 					return (error);
516 				}
517 			}
518 			sfsp++;
519 		}
520 		count++;
521 		mtx_lock(&mountlist_mtx);
522 		nmp = TAILQ_NEXT(mp, mnt_list);
523 		vfs_unbusy(mp);
524 	}
525 	mtx_unlock(&mountlist_mtx);
526 	if (sfsp != NULL && count > maxcount)
527 		*countp = maxcount;
528 	else
529 		*countp = count;
530 	return (0);
531 }
532 
533 #ifdef COMPAT_FREEBSD4
534 /*
535  * Get old format filesystem statistics.
536  */
537 static void freebsd4_cvtstatfs(struct statfs *, struct ostatfs *);
538 
539 #ifndef _SYS_SYSPROTO_H_
540 struct freebsd4_statfs_args {
541 	char *path;
542 	struct ostatfs *buf;
543 };
544 #endif
545 int
546 freebsd4_statfs(struct thread *td, struct freebsd4_statfs_args *uap)
547 {
548 	struct ostatfs osb;
549 	struct statfs *sfp;
550 	int error;
551 
552 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
553 	error = kern_statfs(td, uap->path, UIO_USERSPACE, sfp);
554 	if (error == 0) {
555 		freebsd4_cvtstatfs(sfp, &osb);
556 		error = copyout(&osb, uap->buf, sizeof(osb));
557 	}
558 	free(sfp, M_STATFS);
559 	return (error);
560 }
561 
562 /*
563  * Get filesystem statistics.
564  */
565 #ifndef _SYS_SYSPROTO_H_
566 struct freebsd4_fstatfs_args {
567 	int fd;
568 	struct ostatfs *buf;
569 };
570 #endif
571 int
572 freebsd4_fstatfs(struct thread *td, struct freebsd4_fstatfs_args *uap)
573 {
574 	struct ostatfs osb;
575 	struct statfs *sfp;
576 	int error;
577 
578 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
579 	error = kern_fstatfs(td, uap->fd, sfp);
580 	if (error == 0) {
581 		freebsd4_cvtstatfs(sfp, &osb);
582 		error = copyout(&osb, uap->buf, sizeof(osb));
583 	}
584 	free(sfp, M_STATFS);
585 	return (error);
586 }
587 
588 /*
589  * Get statistics on all filesystems.
590  */
591 #ifndef _SYS_SYSPROTO_H_
592 struct freebsd4_getfsstat_args {
593 	struct ostatfs *buf;
594 	long bufsize;
595 	int mode;
596 };
597 #endif
598 int
599 freebsd4_getfsstat(struct thread *td, struct freebsd4_getfsstat_args *uap)
600 {
601 	struct statfs *buf, *sp;
602 	struct ostatfs osb;
603 	size_t count, size;
604 	int error;
605 
606 	if (uap->bufsize < 0)
607 		return (EINVAL);
608 	count = uap->bufsize / sizeof(struct ostatfs);
609 	if (count > SIZE_MAX / sizeof(struct statfs))
610 		return (EINVAL);
611 	size = count * sizeof(struct statfs);
612 	error = kern_getfsstat(td, &buf, size, &count, UIO_SYSSPACE,
613 	    uap->mode);
614 	if (error == 0)
615 		td->td_retval[0] = count;
616 	if (size != 0) {
617 		sp = buf;
618 		while (count != 0 && error == 0) {
619 			freebsd4_cvtstatfs(sp, &osb);
620 			error = copyout(&osb, uap->buf, sizeof(osb));
621 			sp++;
622 			uap->buf++;
623 			count--;
624 		}
625 		free(buf, M_STATFS);
626 	}
627 	return (error);
628 }
629 
630 /*
631  * Implement fstatfs() for (NFS) file handles.
632  */
633 #ifndef _SYS_SYSPROTO_H_
634 struct freebsd4_fhstatfs_args {
635 	struct fhandle *u_fhp;
636 	struct ostatfs *buf;
637 };
638 #endif
639 int
640 freebsd4_fhstatfs(struct thread *td, struct freebsd4_fhstatfs_args *uap)
641 {
642 	struct ostatfs osb;
643 	struct statfs *sfp;
644 	fhandle_t fh;
645 	int error;
646 
647 	error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t));
648 	if (error != 0)
649 		return (error);
650 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
651 	error = kern_fhstatfs(td, fh, sfp);
652 	if (error == 0) {
653 		freebsd4_cvtstatfs(sfp, &osb);
654 		error = copyout(&osb, uap->buf, sizeof(osb));
655 	}
656 	free(sfp, M_STATFS);
657 	return (error);
658 }
659 
660 /*
661  * Convert a new format statfs structure to an old format statfs structure.
662  */
663 static void
664 freebsd4_cvtstatfs(struct statfs *nsp, struct ostatfs *osp)
665 {
666 
667 	statfs_scale_blocks(nsp, LONG_MAX);
668 	bzero(osp, sizeof(*osp));
669 	osp->f_bsize = nsp->f_bsize;
670 	osp->f_iosize = MIN(nsp->f_iosize, LONG_MAX);
671 	osp->f_blocks = nsp->f_blocks;
672 	osp->f_bfree = nsp->f_bfree;
673 	osp->f_bavail = nsp->f_bavail;
674 	osp->f_files = MIN(nsp->f_files, LONG_MAX);
675 	osp->f_ffree = MIN(nsp->f_ffree, LONG_MAX);
676 	osp->f_owner = nsp->f_owner;
677 	osp->f_type = nsp->f_type;
678 	osp->f_flags = nsp->f_flags;
679 	osp->f_syncwrites = MIN(nsp->f_syncwrites, LONG_MAX);
680 	osp->f_asyncwrites = MIN(nsp->f_asyncwrites, LONG_MAX);
681 	osp->f_syncreads = MIN(nsp->f_syncreads, LONG_MAX);
682 	osp->f_asyncreads = MIN(nsp->f_asyncreads, LONG_MAX);
683 	strlcpy(osp->f_fstypename, nsp->f_fstypename,
684 	    MIN(MFSNAMELEN, OMFSNAMELEN));
685 	strlcpy(osp->f_mntonname, nsp->f_mntonname,
686 	    MIN(MNAMELEN, OMNAMELEN));
687 	strlcpy(osp->f_mntfromname, nsp->f_mntfromname,
688 	    MIN(MNAMELEN, OMNAMELEN));
689 	osp->f_fsid = nsp->f_fsid;
690 }
691 #endif /* COMPAT_FREEBSD4 */
692 
693 #if defined(COMPAT_FREEBSD11)
694 /*
695  * Get old format filesystem statistics.
696  */
697 static void freebsd11_cvtstatfs(struct statfs *, struct freebsd11_statfs *);
698 
699 int
700 freebsd11_statfs(struct thread *td, struct freebsd11_statfs_args *uap)
701 {
702 	struct freebsd11_statfs osb;
703 	struct statfs *sfp;
704 	int error;
705 
706 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
707 	error = kern_statfs(td, uap->path, UIO_USERSPACE, sfp);
708 	if (error == 0) {
709 		freebsd11_cvtstatfs(sfp, &osb);
710 		error = copyout(&osb, uap->buf, sizeof(osb));
711 	}
712 	free(sfp, M_STATFS);
713 	return (error);
714 }
715 
716 /*
717  * Get filesystem statistics.
718  */
719 int
720 freebsd11_fstatfs(struct thread *td, struct freebsd11_fstatfs_args *uap)
721 {
722 	struct freebsd11_statfs osb;
723 	struct statfs *sfp;
724 	int error;
725 
726 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
727 	error = kern_fstatfs(td, uap->fd, sfp);
728 	if (error == 0) {
729 		freebsd11_cvtstatfs(sfp, &osb);
730 		error = copyout(&osb, uap->buf, sizeof(osb));
731 	}
732 	free(sfp, M_STATFS);
733 	return (error);
734 }
735 
736 /*
737  * Get statistics on all filesystems.
738  */
739 int
740 freebsd11_getfsstat(struct thread *td, struct freebsd11_getfsstat_args *uap)
741 {
742 	struct freebsd11_statfs osb;
743 	struct statfs *buf, *sp;
744 	size_t count, size;
745 	int error;
746 
747 	count = uap->bufsize / sizeof(struct ostatfs);
748 	size = count * sizeof(struct statfs);
749 	error = kern_getfsstat(td, &buf, size, &count, UIO_SYSSPACE,
750 	    uap->mode);
751 	if (error == 0)
752 		td->td_retval[0] = count;
753 	if (size > 0) {
754 		sp = buf;
755 		while (count > 0 && error == 0) {
756 			freebsd11_cvtstatfs(sp, &osb);
757 			error = copyout(&osb, uap->buf, sizeof(osb));
758 			sp++;
759 			uap->buf++;
760 			count--;
761 		}
762 		free(buf, M_STATFS);
763 	}
764 	return (error);
765 }
766 
767 /*
768  * Implement fstatfs() for (NFS) file handles.
769  */
770 int
771 freebsd11_fhstatfs(struct thread *td, struct freebsd11_fhstatfs_args *uap)
772 {
773 	struct freebsd11_statfs osb;
774 	struct statfs *sfp;
775 	fhandle_t fh;
776 	int error;
777 
778 	error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t));
779 	if (error)
780 		return (error);
781 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
782 	error = kern_fhstatfs(td, fh, sfp);
783 	if (error == 0) {
784 		freebsd11_cvtstatfs(sfp, &osb);
785 		error = copyout(&osb, uap->buf, sizeof(osb));
786 	}
787 	free(sfp, M_STATFS);
788 	return (error);
789 }
790 
791 /*
792  * Convert a new format statfs structure to an old format statfs structure.
793  */
794 static void
795 freebsd11_cvtstatfs(struct statfs *nsp, struct freebsd11_statfs *osp)
796 {
797 
798 	bzero(osp, sizeof(*osp));
799 	osp->f_version = FREEBSD11_STATFS_VERSION;
800 	osp->f_type = nsp->f_type;
801 	osp->f_flags = nsp->f_flags;
802 	osp->f_bsize = nsp->f_bsize;
803 	osp->f_iosize = nsp->f_iosize;
804 	osp->f_blocks = nsp->f_blocks;
805 	osp->f_bfree = nsp->f_bfree;
806 	osp->f_bavail = nsp->f_bavail;
807 	osp->f_files = nsp->f_files;
808 	osp->f_ffree = nsp->f_ffree;
809 	osp->f_syncwrites = nsp->f_syncwrites;
810 	osp->f_asyncwrites = nsp->f_asyncwrites;
811 	osp->f_syncreads = nsp->f_syncreads;
812 	osp->f_asyncreads = nsp->f_asyncreads;
813 	osp->f_namemax = nsp->f_namemax;
814 	osp->f_owner = nsp->f_owner;
815 	osp->f_fsid = nsp->f_fsid;
816 	strlcpy(osp->f_fstypename, nsp->f_fstypename,
817 	    MIN(MFSNAMELEN, sizeof(osp->f_fstypename)));
818 	strlcpy(osp->f_mntonname, nsp->f_mntonname,
819 	    MIN(MNAMELEN, sizeof(osp->f_mntonname)));
820 	strlcpy(osp->f_mntfromname, nsp->f_mntfromname,
821 	    MIN(MNAMELEN, sizeof(osp->f_mntfromname)));
822 }
823 #endif /* COMPAT_FREEBSD11 */
824 
825 /*
826  * Change current working directory to a given file descriptor.
827  */
828 #ifndef _SYS_SYSPROTO_H_
829 struct fchdir_args {
830 	int	fd;
831 };
832 #endif
833 int
834 sys_fchdir(struct thread *td, struct fchdir_args *uap)
835 {
836 	struct vnode *vp, *tdp;
837 	struct mount *mp;
838 	struct file *fp;
839 	int error;
840 
841 	AUDIT_ARG_FD(uap->fd);
842 	error = getvnode(td, uap->fd, &cap_fchdir_rights,
843 	    &fp);
844 	if (error != 0)
845 		return (error);
846 	vp = fp->f_vnode;
847 	vrefact(vp);
848 	fdrop(fp, td);
849 	vn_lock(vp, LK_SHARED | LK_RETRY);
850 	AUDIT_ARG_VNODE1(vp);
851 	error = change_dir(vp, td);
852 	while (!error && (mp = vp->v_mountedhere) != NULL) {
853 		if (vfs_busy(mp, 0))
854 			continue;
855 		error = VFS_ROOT(mp, LK_SHARED, &tdp);
856 		vfs_unbusy(mp);
857 		if (error != 0)
858 			break;
859 		vput(vp);
860 		vp = tdp;
861 	}
862 	if (error != 0) {
863 		vput(vp);
864 		return (error);
865 	}
866 	VOP_UNLOCK(vp, 0);
867 	pwd_chdir(td, vp);
868 	return (0);
869 }
870 
871 /*
872  * Change current working directory (``.'').
873  */
874 #ifndef _SYS_SYSPROTO_H_
875 struct chdir_args {
876 	char	*path;
877 };
878 #endif
879 int
880 sys_chdir(struct thread *td, struct chdir_args *uap)
881 {
882 
883 	return (kern_chdir(td, uap->path, UIO_USERSPACE));
884 }
885 
886 int
887 kern_chdir(struct thread *td, const char *path, enum uio_seg pathseg)
888 {
889 	struct nameidata nd;
890 	int error;
891 
892 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF | AUDITVNODE1,
893 	    pathseg, path, td);
894 	if ((error = namei(&nd)) != 0)
895 		return (error);
896 	if ((error = change_dir(nd.ni_vp, td)) != 0) {
897 		vput(nd.ni_vp);
898 		NDFREE(&nd, NDF_ONLY_PNBUF);
899 		return (error);
900 	}
901 	VOP_UNLOCK(nd.ni_vp, 0);
902 	NDFREE(&nd, NDF_ONLY_PNBUF);
903 	pwd_chdir(td, nd.ni_vp);
904 	return (0);
905 }
906 
907 /*
908  * Change notion of root (``/'') directory.
909  */
910 #ifndef _SYS_SYSPROTO_H_
911 struct chroot_args {
912 	char	*path;
913 };
914 #endif
915 int
916 sys_chroot(struct thread *td, struct chroot_args *uap)
917 {
918 	struct nameidata nd;
919 	int error;
920 
921 	error = priv_check(td, PRIV_VFS_CHROOT);
922 	if (error != 0)
923 		return (error);
924 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF | AUDITVNODE1,
925 	    UIO_USERSPACE, uap->path, td);
926 	error = namei(&nd);
927 	if (error != 0)
928 		goto error;
929 	error = change_dir(nd.ni_vp, td);
930 	if (error != 0)
931 		goto e_vunlock;
932 #ifdef MAC
933 	error = mac_vnode_check_chroot(td->td_ucred, nd.ni_vp);
934 	if (error != 0)
935 		goto e_vunlock;
936 #endif
937 	VOP_UNLOCK(nd.ni_vp, 0);
938 	error = pwd_chroot(td, nd.ni_vp);
939 	vrele(nd.ni_vp);
940 	NDFREE(&nd, NDF_ONLY_PNBUF);
941 	return (error);
942 e_vunlock:
943 	vput(nd.ni_vp);
944 error:
945 	NDFREE(&nd, NDF_ONLY_PNBUF);
946 	return (error);
947 }
948 
949 /*
950  * Common routine for chroot and chdir.  Callers must provide a locked vnode
951  * instance.
952  */
953 int
954 change_dir(struct vnode *vp, struct thread *td)
955 {
956 #ifdef MAC
957 	int error;
958 #endif
959 
960 	ASSERT_VOP_LOCKED(vp, "change_dir(): vp not locked");
961 	if (vp->v_type != VDIR)
962 		return (ENOTDIR);
963 #ifdef MAC
964 	error = mac_vnode_check_chdir(td->td_ucred, vp);
965 	if (error != 0)
966 		return (error);
967 #endif
968 	return (VOP_ACCESS(vp, VEXEC, td->td_ucred, td));
969 }
970 
971 static __inline void
972 flags_to_rights(int flags, cap_rights_t *rightsp)
973 {
974 
975 	if (flags & O_EXEC) {
976 		cap_rights_set(rightsp, CAP_FEXECVE);
977 	} else {
978 		switch ((flags & O_ACCMODE)) {
979 		case O_RDONLY:
980 			cap_rights_set(rightsp, CAP_READ);
981 			break;
982 		case O_RDWR:
983 			cap_rights_set(rightsp, CAP_READ);
984 			/* FALLTHROUGH */
985 		case O_WRONLY:
986 			cap_rights_set(rightsp, CAP_WRITE);
987 			if (!(flags & (O_APPEND | O_TRUNC)))
988 				cap_rights_set(rightsp, CAP_SEEK);
989 			break;
990 		}
991 	}
992 
993 	if (flags & O_CREAT)
994 		cap_rights_set(rightsp, CAP_CREATE);
995 
996 	if (flags & O_TRUNC)
997 		cap_rights_set(rightsp, CAP_FTRUNCATE);
998 
999 	if (flags & (O_SYNC | O_FSYNC))
1000 		cap_rights_set(rightsp, CAP_FSYNC);
1001 
1002 	if (flags & (O_EXLOCK | O_SHLOCK))
1003 		cap_rights_set(rightsp, CAP_FLOCK);
1004 }
1005 
1006 /*
1007  * Check permissions, allocate an open file structure, and call the device
1008  * open routine if any.
1009  */
1010 #ifndef _SYS_SYSPROTO_H_
1011 struct open_args {
1012 	char	*path;
1013 	int	flags;
1014 	int	mode;
1015 };
1016 #endif
1017 int
1018 sys_open(struct thread *td, struct open_args *uap)
1019 {
1020 
1021 	return (kern_openat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
1022 	    uap->flags, uap->mode));
1023 }
1024 
1025 #ifndef _SYS_SYSPROTO_H_
1026 struct openat_args {
1027 	int	fd;
1028 	char	*path;
1029 	int	flag;
1030 	int	mode;
1031 };
1032 #endif
1033 int
1034 sys_openat(struct thread *td, struct openat_args *uap)
1035 {
1036 
1037 	AUDIT_ARG_FD(uap->fd);
1038 	return (kern_openat(td, uap->fd, uap->path, UIO_USERSPACE, uap->flag,
1039 	    uap->mode));
1040 }
1041 
1042 int
1043 kern_openat(struct thread *td, int fd, const char *path, enum uio_seg pathseg,
1044     int flags, int mode)
1045 {
1046 	struct proc *p = td->td_proc;
1047 	struct filedesc *fdp = p->p_fd;
1048 	struct file *fp;
1049 	struct vnode *vp;
1050 	struct nameidata nd;
1051 	cap_rights_t rights;
1052 	int cmode, error, indx;
1053 
1054 	indx = -1;
1055 
1056 	AUDIT_ARG_FFLAGS(flags);
1057 	AUDIT_ARG_MODE(mode);
1058 	cap_rights_init(&rights, CAP_LOOKUP);
1059 	flags_to_rights(flags, &rights);
1060 	/*
1061 	 * Only one of the O_EXEC, O_RDONLY, O_WRONLY and O_RDWR flags
1062 	 * may be specified.
1063 	 */
1064 	if (flags & O_EXEC) {
1065 		if (flags & O_ACCMODE)
1066 			return (EINVAL);
1067 	} else if ((flags & O_ACCMODE) == O_ACCMODE) {
1068 		return (EINVAL);
1069 	} else {
1070 		flags = FFLAGS(flags);
1071 	}
1072 
1073 	/*
1074 	 * Allocate a file structure. The descriptor to reference it
1075 	 * is allocated and set by finstall() below.
1076 	 */
1077 	error = falloc_noinstall(td, &fp);
1078 	if (error != 0)
1079 		return (error);
1080 	/*
1081 	 * An extra reference on `fp' has been held for us by
1082 	 * falloc_noinstall().
1083 	 */
1084 	/* Set the flags early so the finit in devfs can pick them up. */
1085 	fp->f_flag = flags & FMASK;
1086 	cmode = ((mode & ~fdp->fd_cmask) & ALLPERMS) & ~S_ISTXT;
1087 	NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | AUDITVNODE1, pathseg, path, fd,
1088 	    &rights, td);
1089 	td->td_dupfd = -1;		/* XXX check for fdopen */
1090 	error = vn_open(&nd, &flags, cmode, fp);
1091 	if (error != 0) {
1092 		/*
1093 		 * If the vn_open replaced the method vector, something
1094 		 * wonderous happened deep below and we just pass it up
1095 		 * pretending we know what we do.
1096 		 */
1097 		if (error == ENXIO && fp->f_ops != &badfileops)
1098 			goto success;
1099 
1100 		/*
1101 		 * Handle special fdopen() case. bleh.
1102 		 *
1103 		 * Don't do this for relative (capability) lookups; we don't
1104 		 * understand exactly what would happen, and we don't think
1105 		 * that it ever should.
1106 		 */
1107 		if ((nd.ni_lcf & NI_LCF_STRICTRELATIVE) == 0 &&
1108 		    (error == ENODEV || error == ENXIO) &&
1109 		    td->td_dupfd >= 0) {
1110 			error = dupfdopen(td, fdp, td->td_dupfd, flags, error,
1111 			    &indx);
1112 			if (error == 0)
1113 				goto success;
1114 		}
1115 
1116 		goto bad;
1117 	}
1118 	td->td_dupfd = 0;
1119 	NDFREE(&nd, NDF_ONLY_PNBUF);
1120 	vp = nd.ni_vp;
1121 
1122 	/*
1123 	 * Store the vnode, for any f_type. Typically, the vnode use
1124 	 * count is decremented by direct call to vn_closefile() for
1125 	 * files that switched type in the cdevsw fdopen() method.
1126 	 */
1127 	fp->f_vnode = vp;
1128 	/*
1129 	 * If the file wasn't claimed by devfs bind it to the normal
1130 	 * vnode operations here.
1131 	 */
1132 	if (fp->f_ops == &badfileops) {
1133 		KASSERT(vp->v_type != VFIFO, ("Unexpected fifo."));
1134 		fp->f_seqcount = 1;
1135 		finit(fp, (flags & FMASK) | (fp->f_flag & FHASLOCK),
1136 		    DTYPE_VNODE, vp, &vnops);
1137 	}
1138 
1139 	VOP_UNLOCK(vp, 0);
1140 	if (flags & O_TRUNC) {
1141 		error = fo_truncate(fp, 0, td->td_ucred, td);
1142 		if (error != 0)
1143 			goto bad;
1144 	}
1145 success:
1146 	/*
1147 	 * If we haven't already installed the FD (for dupfdopen), do so now.
1148 	 */
1149 	if (indx == -1) {
1150 		struct filecaps *fcaps;
1151 
1152 #ifdef CAPABILITIES
1153 		if ((nd.ni_lcf & NI_LCF_STRICTRELATIVE) != 0)
1154 			fcaps = &nd.ni_filecaps;
1155 		else
1156 #endif
1157 			fcaps = NULL;
1158 		error = finstall(td, fp, &indx, flags, fcaps);
1159 		/* On success finstall() consumes fcaps. */
1160 		if (error != 0) {
1161 			filecaps_free(&nd.ni_filecaps);
1162 			goto bad;
1163 		}
1164 	} else {
1165 		filecaps_free(&nd.ni_filecaps);
1166 	}
1167 
1168 	/*
1169 	 * Release our private reference, leaving the one associated with
1170 	 * the descriptor table intact.
1171 	 */
1172 	fdrop(fp, td);
1173 	td->td_retval[0] = indx;
1174 	return (0);
1175 bad:
1176 	KASSERT(indx == -1, ("indx=%d, should be -1", indx));
1177 	fdrop(fp, td);
1178 	return (error);
1179 }
1180 
1181 #ifdef COMPAT_43
1182 /*
1183  * Create a file.
1184  */
1185 #ifndef _SYS_SYSPROTO_H_
1186 struct ocreat_args {
1187 	char	*path;
1188 	int	mode;
1189 };
1190 #endif
1191 int
1192 ocreat(struct thread *td, struct ocreat_args *uap)
1193 {
1194 
1195 	return (kern_openat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
1196 	    O_WRONLY | O_CREAT | O_TRUNC, uap->mode));
1197 }
1198 #endif /* COMPAT_43 */
1199 
1200 /*
1201  * Create a special file.
1202  */
1203 #ifndef _SYS_SYSPROTO_H_
1204 struct mknodat_args {
1205 	int	fd;
1206 	char	*path;
1207 	mode_t	mode;
1208 	dev_t	dev;
1209 };
1210 #endif
1211 int
1212 sys_mknodat(struct thread *td, struct mknodat_args *uap)
1213 {
1214 
1215 	return (kern_mknodat(td, uap->fd, uap->path, UIO_USERSPACE, uap->mode,
1216 	    uap->dev));
1217 }
1218 
1219 #if defined(COMPAT_FREEBSD11)
1220 int
1221 freebsd11_mknod(struct thread *td,
1222     struct freebsd11_mknod_args *uap)
1223 {
1224 
1225 	return (kern_mknodat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
1226 	    uap->mode, uap->dev));
1227 }
1228 
1229 int
1230 freebsd11_mknodat(struct thread *td,
1231     struct freebsd11_mknodat_args *uap)
1232 {
1233 
1234 	return (kern_mknodat(td, uap->fd, uap->path, UIO_USERSPACE, uap->mode,
1235 	    uap->dev));
1236 }
1237 #endif /* COMPAT_FREEBSD11 */
1238 
1239 int
1240 kern_mknodat(struct thread *td, int fd, const char *path, enum uio_seg pathseg,
1241     int mode, dev_t dev)
1242 {
1243 	struct vnode *vp;
1244 	struct mount *mp;
1245 	struct vattr vattr;
1246 	struct nameidata nd;
1247 	int error, whiteout = 0;
1248 
1249 	AUDIT_ARG_MODE(mode);
1250 	AUDIT_ARG_DEV(dev);
1251 	switch (mode & S_IFMT) {
1252 	case S_IFCHR:
1253 	case S_IFBLK:
1254 		error = priv_check(td, PRIV_VFS_MKNOD_DEV);
1255 		if (error == 0 && dev == VNOVAL)
1256 			error = EINVAL;
1257 		break;
1258 	case S_IFWHT:
1259 		error = priv_check(td, PRIV_VFS_MKNOD_WHT);
1260 		break;
1261 	case S_IFIFO:
1262 		if (dev == 0)
1263 			return (kern_mkfifoat(td, fd, path, pathseg, mode));
1264 		/* FALLTHROUGH */
1265 	default:
1266 		error = EINVAL;
1267 		break;
1268 	}
1269 	if (error != 0)
1270 		return (error);
1271 restart:
1272 	bwillwrite();
1273 	NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | SAVENAME | AUDITVNODE1 |
1274 	    NOCACHE, pathseg, path, fd, &cap_mknodat_rights,
1275 	    td);
1276 	if ((error = namei(&nd)) != 0)
1277 		return (error);
1278 	vp = nd.ni_vp;
1279 	if (vp != NULL) {
1280 		NDFREE(&nd, NDF_ONLY_PNBUF);
1281 		if (vp == nd.ni_dvp)
1282 			vrele(nd.ni_dvp);
1283 		else
1284 			vput(nd.ni_dvp);
1285 		vrele(vp);
1286 		return (EEXIST);
1287 	} else {
1288 		VATTR_NULL(&vattr);
1289 		vattr.va_mode = (mode & ALLPERMS) &
1290 		    ~td->td_proc->p_fd->fd_cmask;
1291 		vattr.va_rdev = dev;
1292 		whiteout = 0;
1293 
1294 		switch (mode & S_IFMT) {
1295 		case S_IFCHR:
1296 			vattr.va_type = VCHR;
1297 			break;
1298 		case S_IFBLK:
1299 			vattr.va_type = VBLK;
1300 			break;
1301 		case S_IFWHT:
1302 			whiteout = 1;
1303 			break;
1304 		default:
1305 			panic("kern_mknod: invalid mode");
1306 		}
1307 	}
1308 	if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
1309 		NDFREE(&nd, NDF_ONLY_PNBUF);
1310 		vput(nd.ni_dvp);
1311 		if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
1312 			return (error);
1313 		goto restart;
1314 	}
1315 #ifdef MAC
1316 	if (error == 0 && !whiteout)
1317 		error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp,
1318 		    &nd.ni_cnd, &vattr);
1319 #endif
1320 	if (error == 0) {
1321 		if (whiteout)
1322 			error = VOP_WHITEOUT(nd.ni_dvp, &nd.ni_cnd, CREATE);
1323 		else {
1324 			error = VOP_MKNOD(nd.ni_dvp, &nd.ni_vp,
1325 						&nd.ni_cnd, &vattr);
1326 			if (error == 0)
1327 				vput(nd.ni_vp);
1328 		}
1329 	}
1330 	NDFREE(&nd, NDF_ONLY_PNBUF);
1331 	vput(nd.ni_dvp);
1332 	vn_finished_write(mp);
1333 	return (error);
1334 }
1335 
1336 /*
1337  * Create a named pipe.
1338  */
1339 #ifndef _SYS_SYSPROTO_H_
1340 struct mkfifo_args {
1341 	char	*path;
1342 	int	mode;
1343 };
1344 #endif
1345 int
1346 sys_mkfifo(struct thread *td, struct mkfifo_args *uap)
1347 {
1348 
1349 	return (kern_mkfifoat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
1350 	    uap->mode));
1351 }
1352 
1353 #ifndef _SYS_SYSPROTO_H_
1354 struct mkfifoat_args {
1355 	int	fd;
1356 	char	*path;
1357 	mode_t	mode;
1358 };
1359 #endif
1360 int
1361 sys_mkfifoat(struct thread *td, struct mkfifoat_args *uap)
1362 {
1363 
1364 	return (kern_mkfifoat(td, uap->fd, uap->path, UIO_USERSPACE,
1365 	    uap->mode));
1366 }
1367 
1368 int
1369 kern_mkfifoat(struct thread *td, int fd, const char *path,
1370     enum uio_seg pathseg, int mode)
1371 {
1372 	struct mount *mp;
1373 	struct vattr vattr;
1374 	struct nameidata nd;
1375 	int error;
1376 
1377 	AUDIT_ARG_MODE(mode);
1378 restart:
1379 	bwillwrite();
1380 	NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | SAVENAME | AUDITVNODE1 |
1381 	    NOCACHE, pathseg, path, fd, &cap_mkfifoat_rights,
1382 	    td);
1383 	if ((error = namei(&nd)) != 0)
1384 		return (error);
1385 	if (nd.ni_vp != NULL) {
1386 		NDFREE(&nd, NDF_ONLY_PNBUF);
1387 		if (nd.ni_vp == nd.ni_dvp)
1388 			vrele(nd.ni_dvp);
1389 		else
1390 			vput(nd.ni_dvp);
1391 		vrele(nd.ni_vp);
1392 		return (EEXIST);
1393 	}
1394 	if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
1395 		NDFREE(&nd, NDF_ONLY_PNBUF);
1396 		vput(nd.ni_dvp);
1397 		if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
1398 			return (error);
1399 		goto restart;
1400 	}
1401 	VATTR_NULL(&vattr);
1402 	vattr.va_type = VFIFO;
1403 	vattr.va_mode = (mode & ALLPERMS) & ~td->td_proc->p_fd->fd_cmask;
1404 #ifdef MAC
1405 	error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
1406 	    &vattr);
1407 	if (error != 0)
1408 		goto out;
1409 #endif
1410 	error = VOP_MKNOD(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
1411 	if (error == 0)
1412 		vput(nd.ni_vp);
1413 #ifdef MAC
1414 out:
1415 #endif
1416 	vput(nd.ni_dvp);
1417 	vn_finished_write(mp);
1418 	NDFREE(&nd, NDF_ONLY_PNBUF);
1419 	return (error);
1420 }
1421 
1422 /*
1423  * Make a hard file link.
1424  */
1425 #ifndef _SYS_SYSPROTO_H_
1426 struct link_args {
1427 	char	*path;
1428 	char	*link;
1429 };
1430 #endif
1431 int
1432 sys_link(struct thread *td, struct link_args *uap)
1433 {
1434 
1435 	return (kern_linkat(td, AT_FDCWD, AT_FDCWD, uap->path, uap->link,
1436 	    UIO_USERSPACE, FOLLOW));
1437 }
1438 
1439 #ifndef _SYS_SYSPROTO_H_
1440 struct linkat_args {
1441 	int	fd1;
1442 	char	*path1;
1443 	int	fd2;
1444 	char	*path2;
1445 	int	flag;
1446 };
1447 #endif
1448 int
1449 sys_linkat(struct thread *td, struct linkat_args *uap)
1450 {
1451 	int flag;
1452 
1453 	flag = uap->flag;
1454 	if ((flag & ~(AT_SYMLINK_FOLLOW | AT_BENEATH)) != 0)
1455 		return (EINVAL);
1456 
1457 	return (kern_linkat(td, uap->fd1, uap->fd2, uap->path1, uap->path2,
1458 	    UIO_USERSPACE, ((flag & AT_SYMLINK_FOLLOW) != 0 ? FOLLOW :
1459 	    NOFOLLOW) | ((flag & AT_BENEATH) != 0 ? BENEATH : 0)));
1460 }
1461 
1462 int hardlink_check_uid = 0;
1463 SYSCTL_INT(_security_bsd, OID_AUTO, hardlink_check_uid, CTLFLAG_RW,
1464     &hardlink_check_uid, 0,
1465     "Unprivileged processes cannot create hard links to files owned by other "
1466     "users");
1467 static int hardlink_check_gid = 0;
1468 SYSCTL_INT(_security_bsd, OID_AUTO, hardlink_check_gid, CTLFLAG_RW,
1469     &hardlink_check_gid, 0,
1470     "Unprivileged processes cannot create hard links to files owned by other "
1471     "groups");
1472 
1473 static int
1474 can_hardlink(struct vnode *vp, struct ucred *cred)
1475 {
1476 	struct vattr va;
1477 	int error;
1478 
1479 	if (!hardlink_check_uid && !hardlink_check_gid)
1480 		return (0);
1481 
1482 	error = VOP_GETATTR(vp, &va, cred);
1483 	if (error != 0)
1484 		return (error);
1485 
1486 	if (hardlink_check_uid && cred->cr_uid != va.va_uid) {
1487 		error = priv_check_cred(cred, PRIV_VFS_LINK);
1488 		if (error != 0)
1489 			return (error);
1490 	}
1491 
1492 	if (hardlink_check_gid && !groupmember(va.va_gid, cred)) {
1493 		error = priv_check_cred(cred, PRIV_VFS_LINK);
1494 		if (error != 0)
1495 			return (error);
1496 	}
1497 
1498 	return (0);
1499 }
1500 
1501 int
1502 kern_linkat(struct thread *td, int fd1, int fd2, const char *path1,
1503     const char *path2, enum uio_seg segflag, int follow)
1504 {
1505 	struct nameidata nd;
1506 	int error;
1507 
1508 	do {
1509 		bwillwrite();
1510 		NDINIT_ATRIGHTS(&nd, LOOKUP, follow | AUDITVNODE1, segflag,
1511 		    path1, fd1, &cap_linkat_source_rights, td);
1512 		if ((error = namei(&nd)) != 0)
1513 			return (error);
1514 		NDFREE(&nd, NDF_ONLY_PNBUF);
1515 		error = kern_linkat_vp(td, nd.ni_vp, fd2, path2, segflag);
1516 	} while (error ==  EAGAIN);
1517 	return (error);
1518 }
1519 
1520 static int
1521 kern_linkat_vp(struct thread *td, struct vnode *vp, int fd, const char *path,
1522     enum uio_seg segflag)
1523 {
1524 	struct nameidata nd;
1525 	struct mount *mp;
1526 	int error;
1527 
1528 	if (vp->v_type == VDIR) {
1529 		vrele(vp);
1530 		return (EPERM);		/* POSIX */
1531 	}
1532 	NDINIT_ATRIGHTS(&nd, CREATE,
1533 	    LOCKPARENT | SAVENAME | AUDITVNODE2 | NOCACHE, segflag, path, fd,
1534 	    &cap_linkat_target_rights, td);
1535 	if ((error = namei(&nd)) == 0) {
1536 		if (nd.ni_vp != NULL) {
1537 			NDFREE(&nd, NDF_ONLY_PNBUF);
1538 			if (nd.ni_dvp == nd.ni_vp)
1539 				vrele(nd.ni_dvp);
1540 			else
1541 				vput(nd.ni_dvp);
1542 			vrele(nd.ni_vp);
1543 			vrele(vp);
1544 			return (EEXIST);
1545 		} else if (nd.ni_dvp->v_mount != vp->v_mount) {
1546 			/*
1547 			 * Cross-device link.  No need to recheck
1548 			 * vp->v_type, since it cannot change, except
1549 			 * to VBAD.
1550 			 */
1551 			NDFREE(&nd, NDF_ONLY_PNBUF);
1552 			vput(nd.ni_dvp);
1553 			vrele(vp);
1554 			return (EXDEV);
1555 		} else if ((error = vn_lock(vp, LK_EXCLUSIVE)) == 0) {
1556 			error = can_hardlink(vp, td->td_ucred);
1557 #ifdef MAC
1558 			if (error == 0)
1559 				error = mac_vnode_check_link(td->td_ucred,
1560 				    nd.ni_dvp, vp, &nd.ni_cnd);
1561 #endif
1562 			if (error != 0) {
1563 				vput(vp);
1564 				vput(nd.ni_dvp);
1565 				NDFREE(&nd, NDF_ONLY_PNBUF);
1566 				return (error);
1567 			}
1568 			error = vn_start_write(vp, &mp, V_NOWAIT);
1569 			if (error != 0) {
1570 				vput(vp);
1571 				vput(nd.ni_dvp);
1572 				NDFREE(&nd, NDF_ONLY_PNBUF);
1573 				error = vn_start_write(NULL, &mp,
1574 				    V_XSLEEP | PCATCH);
1575 				if (error != 0)
1576 					return (error);
1577 				return (EAGAIN);
1578 			}
1579 			error = VOP_LINK(nd.ni_dvp, vp, &nd.ni_cnd);
1580 			VOP_UNLOCK(vp, 0);
1581 			vput(nd.ni_dvp);
1582 			vn_finished_write(mp);
1583 			NDFREE(&nd, NDF_ONLY_PNBUF);
1584 		} else {
1585 			vput(nd.ni_dvp);
1586 			NDFREE(&nd, NDF_ONLY_PNBUF);
1587 			vrele(vp);
1588 			return (EAGAIN);
1589 		}
1590 	}
1591 	vrele(vp);
1592 	return (error);
1593 }
1594 
1595 /*
1596  * Make a symbolic link.
1597  */
1598 #ifndef _SYS_SYSPROTO_H_
1599 struct symlink_args {
1600 	char	*path;
1601 	char	*link;
1602 };
1603 #endif
1604 int
1605 sys_symlink(struct thread *td, struct symlink_args *uap)
1606 {
1607 
1608 	return (kern_symlinkat(td, uap->path, AT_FDCWD, uap->link,
1609 	    UIO_USERSPACE));
1610 }
1611 
1612 #ifndef _SYS_SYSPROTO_H_
1613 struct symlinkat_args {
1614 	char	*path;
1615 	int	fd;
1616 	char	*path2;
1617 };
1618 #endif
1619 int
1620 sys_symlinkat(struct thread *td, struct symlinkat_args *uap)
1621 {
1622 
1623 	return (kern_symlinkat(td, uap->path1, uap->fd, uap->path2,
1624 	    UIO_USERSPACE));
1625 }
1626 
1627 int
1628 kern_symlinkat(struct thread *td, const char *path1, int fd, const char *path2,
1629     enum uio_seg segflg)
1630 {
1631 	struct mount *mp;
1632 	struct vattr vattr;
1633 	const char *syspath;
1634 	char *tmppath;
1635 	struct nameidata nd;
1636 	int error;
1637 
1638 	if (segflg == UIO_SYSSPACE) {
1639 		syspath = path1;
1640 	} else {
1641 		tmppath = uma_zalloc(namei_zone, M_WAITOK);
1642 		if ((error = copyinstr(path1, tmppath, MAXPATHLEN, NULL)) != 0)
1643 			goto out;
1644 		syspath = tmppath;
1645 	}
1646 	AUDIT_ARG_TEXT(syspath);
1647 restart:
1648 	bwillwrite();
1649 	NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | SAVENAME | AUDITVNODE1 |
1650 	    NOCACHE, segflg, path2, fd, &cap_symlinkat_rights,
1651 	    td);
1652 	if ((error = namei(&nd)) != 0)
1653 		goto out;
1654 	if (nd.ni_vp) {
1655 		NDFREE(&nd, NDF_ONLY_PNBUF);
1656 		if (nd.ni_vp == nd.ni_dvp)
1657 			vrele(nd.ni_dvp);
1658 		else
1659 			vput(nd.ni_dvp);
1660 		vrele(nd.ni_vp);
1661 		error = EEXIST;
1662 		goto out;
1663 	}
1664 	if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
1665 		NDFREE(&nd, NDF_ONLY_PNBUF);
1666 		vput(nd.ni_dvp);
1667 		if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
1668 			goto out;
1669 		goto restart;
1670 	}
1671 	VATTR_NULL(&vattr);
1672 	vattr.va_mode = ACCESSPERMS &~ td->td_proc->p_fd->fd_cmask;
1673 #ifdef MAC
1674 	vattr.va_type = VLNK;
1675 	error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
1676 	    &vattr);
1677 	if (error != 0)
1678 		goto out2;
1679 #endif
1680 	error = VOP_SYMLINK(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr, syspath);
1681 	if (error == 0)
1682 		vput(nd.ni_vp);
1683 #ifdef MAC
1684 out2:
1685 #endif
1686 	NDFREE(&nd, NDF_ONLY_PNBUF);
1687 	vput(nd.ni_dvp);
1688 	vn_finished_write(mp);
1689 out:
1690 	if (segflg != UIO_SYSSPACE)
1691 		uma_zfree(namei_zone, tmppath);
1692 	return (error);
1693 }
1694 
1695 /*
1696  * Delete a whiteout from the filesystem.
1697  */
1698 #ifndef _SYS_SYSPROTO_H_
1699 struct undelete_args {
1700 	char *path;
1701 };
1702 #endif
1703 int
1704 sys_undelete(struct thread *td, struct undelete_args *uap)
1705 {
1706 	struct mount *mp;
1707 	struct nameidata nd;
1708 	int error;
1709 
1710 restart:
1711 	bwillwrite();
1712 	NDINIT(&nd, DELETE, LOCKPARENT | DOWHITEOUT | AUDITVNODE1,
1713 	    UIO_USERSPACE, uap->path, td);
1714 	error = namei(&nd);
1715 	if (error != 0)
1716 		return (error);
1717 
1718 	if (nd.ni_vp != NULLVP || !(nd.ni_cnd.cn_flags & ISWHITEOUT)) {
1719 		NDFREE(&nd, NDF_ONLY_PNBUF);
1720 		if (nd.ni_vp == nd.ni_dvp)
1721 			vrele(nd.ni_dvp);
1722 		else
1723 			vput(nd.ni_dvp);
1724 		if (nd.ni_vp)
1725 			vrele(nd.ni_vp);
1726 		return (EEXIST);
1727 	}
1728 	if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
1729 		NDFREE(&nd, NDF_ONLY_PNBUF);
1730 		vput(nd.ni_dvp);
1731 		if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
1732 			return (error);
1733 		goto restart;
1734 	}
1735 	error = VOP_WHITEOUT(nd.ni_dvp, &nd.ni_cnd, DELETE);
1736 	NDFREE(&nd, NDF_ONLY_PNBUF);
1737 	vput(nd.ni_dvp);
1738 	vn_finished_write(mp);
1739 	return (error);
1740 }
1741 
1742 /*
1743  * Delete a name from the filesystem.
1744  */
1745 #ifndef _SYS_SYSPROTO_H_
1746 struct unlink_args {
1747 	char	*path;
1748 };
1749 #endif
1750 int
1751 sys_unlink(struct thread *td, struct unlink_args *uap)
1752 {
1753 
1754 	return (kern_unlinkat(td, AT_FDCWD, uap->path, UIO_USERSPACE, 0, 0));
1755 }
1756 
1757 #ifndef _SYS_SYSPROTO_H_
1758 struct unlinkat_args {
1759 	int	fd;
1760 	char	*path;
1761 	int	flag;
1762 };
1763 #endif
1764 int
1765 sys_unlinkat(struct thread *td, struct unlinkat_args *uap)
1766 {
1767 	int fd, flag;
1768 	const char *path;
1769 
1770 	flag = uap->flag;
1771 	fd = uap->fd;
1772 	path = uap->path;
1773 
1774 	if ((flag & ~(AT_REMOVEDIR | AT_BENEATH)) != 0)
1775 		return (EINVAL);
1776 
1777 	if ((uap->flag & AT_REMOVEDIR) != 0)
1778 		return (kern_rmdirat(td, fd, path, UIO_USERSPACE, flag));
1779 	else
1780 		return (kern_unlinkat(td, fd, path, UIO_USERSPACE, flag, 0));
1781 }
1782 
1783 int
1784 kern_unlinkat(struct thread *td, int fd, const char *path,
1785     enum uio_seg pathseg, int flag, ino_t oldinum)
1786 {
1787 	struct mount *mp;
1788 	struct vnode *vp;
1789 	struct nameidata nd;
1790 	struct stat sb;
1791 	int error;
1792 
1793 restart:
1794 	bwillwrite();
1795 	NDINIT_ATRIGHTS(&nd, DELETE, LOCKPARENT | LOCKLEAF | AUDITVNODE1 |
1796 	    ((flag & AT_BENEATH) != 0 ? BENEATH : 0),
1797 	    pathseg, path, fd, &cap_unlinkat_rights, td);
1798 	if ((error = namei(&nd)) != 0)
1799 		return (error == EINVAL ? EPERM : error);
1800 	vp = nd.ni_vp;
1801 	if (vp->v_type == VDIR && oldinum == 0) {
1802 		error = EPERM;		/* POSIX */
1803 	} else if (oldinum != 0 &&
1804 		  ((error = vn_stat(vp, &sb, td->td_ucred, NOCRED, td)) == 0) &&
1805 		  sb.st_ino != oldinum) {
1806 			error = EIDRM;	/* Identifier removed */
1807 	} else {
1808 		/*
1809 		 * The root of a mounted filesystem cannot be deleted.
1810 		 *
1811 		 * XXX: can this only be a VDIR case?
1812 		 */
1813 		if (vp->v_vflag & VV_ROOT)
1814 			error = EBUSY;
1815 	}
1816 	if (error == 0) {
1817 		if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
1818 			NDFREE(&nd, NDF_ONLY_PNBUF);
1819 			vput(nd.ni_dvp);
1820 			if (vp == nd.ni_dvp)
1821 				vrele(vp);
1822 			else
1823 				vput(vp);
1824 			if ((error = vn_start_write(NULL, &mp,
1825 			    V_XSLEEP | PCATCH)) != 0)
1826 				return (error);
1827 			goto restart;
1828 		}
1829 #ifdef MAC
1830 		error = mac_vnode_check_unlink(td->td_ucred, nd.ni_dvp, vp,
1831 		    &nd.ni_cnd);
1832 		if (error != 0)
1833 			goto out;
1834 #endif
1835 		vfs_notify_upper(vp, VFS_NOTIFY_UPPER_UNLINK);
1836 		error = VOP_REMOVE(nd.ni_dvp, vp, &nd.ni_cnd);
1837 #ifdef MAC
1838 out:
1839 #endif
1840 		vn_finished_write(mp);
1841 	}
1842 	NDFREE(&nd, NDF_ONLY_PNBUF);
1843 	vput(nd.ni_dvp);
1844 	if (vp == nd.ni_dvp)
1845 		vrele(vp);
1846 	else
1847 		vput(vp);
1848 	return (error);
1849 }
1850 
1851 /*
1852  * Reposition read/write file offset.
1853  */
1854 #ifndef _SYS_SYSPROTO_H_
1855 struct lseek_args {
1856 	int	fd;
1857 	int	pad;
1858 	off_t	offset;
1859 	int	whence;
1860 };
1861 #endif
1862 int
1863 sys_lseek(struct thread *td, struct lseek_args *uap)
1864 {
1865 
1866 	return (kern_lseek(td, uap->fd, uap->offset, uap->whence));
1867 }
1868 
1869 int
1870 kern_lseek(struct thread *td, int fd, off_t offset, int whence)
1871 {
1872 	struct file *fp;
1873 	int error;
1874 
1875 	AUDIT_ARG_FD(fd);
1876 	error = fget(td, fd, &cap_seek_rights, &fp);
1877 	if (error != 0)
1878 		return (error);
1879 	error = (fp->f_ops->fo_flags & DFLAG_SEEKABLE) != 0 ?
1880 	    fo_seek(fp, offset, whence, td) : ESPIPE;
1881 	fdrop(fp, td);
1882 	return (error);
1883 }
1884 
1885 #if defined(COMPAT_43)
1886 /*
1887  * Reposition read/write file offset.
1888  */
1889 #ifndef _SYS_SYSPROTO_H_
1890 struct olseek_args {
1891 	int	fd;
1892 	long	offset;
1893 	int	whence;
1894 };
1895 #endif
1896 int
1897 olseek(struct thread *td, struct olseek_args *uap)
1898 {
1899 
1900 	return (kern_lseek(td, uap->fd, uap->offset, uap->whence));
1901 }
1902 #endif /* COMPAT_43 */
1903 
1904 #if defined(COMPAT_FREEBSD6)
1905 /* Version with the 'pad' argument */
1906 int
1907 freebsd6_lseek(struct thread *td, struct freebsd6_lseek_args *uap)
1908 {
1909 
1910 	return (kern_lseek(td, uap->fd, uap->offset, uap->whence));
1911 }
1912 #endif
1913 
1914 /*
1915  * Check access permissions using passed credentials.
1916  */
1917 static int
1918 vn_access(struct vnode *vp, int user_flags, struct ucred *cred,
1919      struct thread *td)
1920 {
1921 	accmode_t accmode;
1922 	int error;
1923 
1924 	/* Flags == 0 means only check for existence. */
1925 	if (user_flags == 0)
1926 		return (0);
1927 
1928 	accmode = 0;
1929 	if (user_flags & R_OK)
1930 		accmode |= VREAD;
1931 	if (user_flags & W_OK)
1932 		accmode |= VWRITE;
1933 	if (user_flags & X_OK)
1934 		accmode |= VEXEC;
1935 #ifdef MAC
1936 	error = mac_vnode_check_access(cred, vp, accmode);
1937 	if (error != 0)
1938 		return (error);
1939 #endif
1940 	if ((accmode & VWRITE) == 0 || (error = vn_writechk(vp)) == 0)
1941 		error = VOP_ACCESS(vp, accmode, cred, td);
1942 	return (error);
1943 }
1944 
1945 /*
1946  * Check access permissions using "real" credentials.
1947  */
1948 #ifndef _SYS_SYSPROTO_H_
1949 struct access_args {
1950 	char	*path;
1951 	int	amode;
1952 };
1953 #endif
1954 int
1955 sys_access(struct thread *td, struct access_args *uap)
1956 {
1957 
1958 	return (kern_accessat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
1959 	    0, uap->amode));
1960 }
1961 
1962 #ifndef _SYS_SYSPROTO_H_
1963 struct faccessat_args {
1964 	int	dirfd;
1965 	char	*path;
1966 	int	amode;
1967 	int	flag;
1968 }
1969 #endif
1970 int
1971 sys_faccessat(struct thread *td, struct faccessat_args *uap)
1972 {
1973 
1974 	return (kern_accessat(td, uap->fd, uap->path, UIO_USERSPACE, uap->flag,
1975 	    uap->amode));
1976 }
1977 
1978 int
1979 kern_accessat(struct thread *td, int fd, const char *path,
1980     enum uio_seg pathseg, int flag, int amode)
1981 {
1982 	struct ucred *cred, *usecred;
1983 	struct vnode *vp;
1984 	struct nameidata nd;
1985 	int error;
1986 
1987 	if ((flag & ~(AT_EACCESS | AT_BENEATH)) != 0)
1988 		return (EINVAL);
1989 	if (amode != F_OK && (amode & ~(R_OK | W_OK | X_OK)) != 0)
1990 		return (EINVAL);
1991 
1992 	/*
1993 	 * Create and modify a temporary credential instead of one that
1994 	 * is potentially shared (if we need one).
1995 	 */
1996 	cred = td->td_ucred;
1997 	if ((flag & AT_EACCESS) == 0 &&
1998 	    ((cred->cr_uid != cred->cr_ruid ||
1999 	    cred->cr_rgid != cred->cr_groups[0]))) {
2000 		usecred = crdup(cred);
2001 		usecred->cr_uid = cred->cr_ruid;
2002 		usecred->cr_groups[0] = cred->cr_rgid;
2003 		td->td_ucred = usecred;
2004 	} else
2005 		usecred = cred;
2006 	AUDIT_ARG_VALUE(amode);
2007 	NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF |
2008 	    AUDITVNODE1 | ((flag & AT_BENEATH) != 0 ? BENEATH : 0),
2009 	    pathseg, path, fd, &cap_fstat_rights, td);
2010 	if ((error = namei(&nd)) != 0)
2011 		goto out;
2012 	vp = nd.ni_vp;
2013 
2014 	error = vn_access(vp, amode, usecred, td);
2015 	NDFREE(&nd, NDF_ONLY_PNBUF);
2016 	vput(vp);
2017 out:
2018 	if (usecred != cred) {
2019 		td->td_ucred = cred;
2020 		crfree(usecred);
2021 	}
2022 	return (error);
2023 }
2024 
2025 /*
2026  * Check access permissions using "effective" credentials.
2027  */
2028 #ifndef _SYS_SYSPROTO_H_
2029 struct eaccess_args {
2030 	char	*path;
2031 	int	amode;
2032 };
2033 #endif
2034 int
2035 sys_eaccess(struct thread *td, struct eaccess_args *uap)
2036 {
2037 
2038 	return (kern_accessat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
2039 	    AT_EACCESS, uap->amode));
2040 }
2041 
2042 #if defined(COMPAT_43)
2043 /*
2044  * Get file status; this version follows links.
2045  */
2046 #ifndef _SYS_SYSPROTO_H_
2047 struct ostat_args {
2048 	char	*path;
2049 	struct ostat *ub;
2050 };
2051 #endif
2052 int
2053 ostat(struct thread *td, struct ostat_args *uap)
2054 {
2055 	struct stat sb;
2056 	struct ostat osb;
2057 	int error;
2058 
2059 	error = kern_statat(td, 0, AT_FDCWD, uap->path, UIO_USERSPACE,
2060 	    &sb, NULL);
2061 	if (error != 0)
2062 		return (error);
2063 	cvtstat(&sb, &osb);
2064 	return (copyout(&osb, uap->ub, sizeof (osb)));
2065 }
2066 
2067 /*
2068  * Get file status; this version does not follow links.
2069  */
2070 #ifndef _SYS_SYSPROTO_H_
2071 struct olstat_args {
2072 	char	*path;
2073 	struct ostat *ub;
2074 };
2075 #endif
2076 int
2077 olstat(struct thread *td, struct olstat_args *uap)
2078 {
2079 	struct stat sb;
2080 	struct ostat osb;
2081 	int error;
2082 
2083 	error = kern_statat(td, AT_SYMLINK_NOFOLLOW, AT_FDCWD, uap->path,
2084 	    UIO_USERSPACE, &sb, NULL);
2085 	if (error != 0)
2086 		return (error);
2087 	cvtstat(&sb, &osb);
2088 	return (copyout(&osb, uap->ub, sizeof (osb)));
2089 }
2090 
2091 /*
2092  * Convert from an old to a new stat structure.
2093  * XXX: many values are blindly truncated.
2094  */
2095 void
2096 cvtstat(struct stat *st, struct ostat *ost)
2097 {
2098 
2099 	bzero(ost, sizeof(*ost));
2100 	ost->st_dev = st->st_dev;
2101 	ost->st_ino = st->st_ino;
2102 	ost->st_mode = st->st_mode;
2103 	ost->st_nlink = st->st_nlink;
2104 	ost->st_uid = st->st_uid;
2105 	ost->st_gid = st->st_gid;
2106 	ost->st_rdev = st->st_rdev;
2107 	ost->st_size = MIN(st->st_size, INT32_MAX);
2108 	ost->st_atim = st->st_atim;
2109 	ost->st_mtim = st->st_mtim;
2110 	ost->st_ctim = st->st_ctim;
2111 	ost->st_blksize = st->st_blksize;
2112 	ost->st_blocks = st->st_blocks;
2113 	ost->st_flags = st->st_flags;
2114 	ost->st_gen = st->st_gen;
2115 }
2116 #endif /* COMPAT_43 */
2117 
2118 #if defined(COMPAT_43) || defined(COMPAT_FREEBSD11)
2119 int ino64_trunc_error;
2120 SYSCTL_INT(_vfs, OID_AUTO, ino64_trunc_error, CTLFLAG_RW,
2121     &ino64_trunc_error, 0,
2122     "Error on truncation of device, file or inode number, or link count");
2123 
2124 int
2125 freebsd11_cvtstat(struct stat *st, struct freebsd11_stat *ost)
2126 {
2127 
2128 	ost->st_dev = st->st_dev;
2129 	if (ost->st_dev != st->st_dev) {
2130 		switch (ino64_trunc_error) {
2131 		default:
2132 			/*
2133 			 * Since dev_t is almost raw, don't clamp to the
2134 			 * maximum for case 2, but ignore the error.
2135 			 */
2136 			break;
2137 		case 1:
2138 			return (EOVERFLOW);
2139 		}
2140 	}
2141 	ost->st_ino = st->st_ino;
2142 	if (ost->st_ino != st->st_ino) {
2143 		switch (ino64_trunc_error) {
2144 		default:
2145 		case 0:
2146 			break;
2147 		case 1:
2148 			return (EOVERFLOW);
2149 		case 2:
2150 			ost->st_ino = UINT32_MAX;
2151 			break;
2152 		}
2153 	}
2154 	ost->st_mode = st->st_mode;
2155 	ost->st_nlink = st->st_nlink;
2156 	if (ost->st_nlink != st->st_nlink) {
2157 		switch (ino64_trunc_error) {
2158 		default:
2159 		case 0:
2160 			break;
2161 		case 1:
2162 			return (EOVERFLOW);
2163 		case 2:
2164 			ost->st_nlink = UINT16_MAX;
2165 			break;
2166 		}
2167 	}
2168 	ost->st_uid = st->st_uid;
2169 	ost->st_gid = st->st_gid;
2170 	ost->st_rdev = st->st_rdev;
2171 	if (ost->st_rdev != st->st_rdev) {
2172 		switch (ino64_trunc_error) {
2173 		default:
2174 			break;
2175 		case 1:
2176 			return (EOVERFLOW);
2177 		}
2178 	}
2179 	ost->st_atim = st->st_atim;
2180 	ost->st_mtim = st->st_mtim;
2181 	ost->st_ctim = st->st_ctim;
2182 	ost->st_size = st->st_size;
2183 	ost->st_blocks = st->st_blocks;
2184 	ost->st_blksize = st->st_blksize;
2185 	ost->st_flags = st->st_flags;
2186 	ost->st_gen = st->st_gen;
2187 	ost->st_lspare = 0;
2188 	ost->st_birthtim = st->st_birthtim;
2189 	bzero((char *)&ost->st_birthtim + sizeof(ost->st_birthtim),
2190 	    sizeof(*ost) - offsetof(struct freebsd11_stat,
2191 	    st_birthtim) - sizeof(ost->st_birthtim));
2192 	return (0);
2193 }
2194 
2195 int
2196 freebsd11_stat(struct thread *td, struct freebsd11_stat_args* uap)
2197 {
2198 	struct stat sb;
2199 	struct freebsd11_stat osb;
2200 	int error;
2201 
2202 	error = kern_statat(td, 0, AT_FDCWD, uap->path, UIO_USERSPACE,
2203 	    &sb, NULL);
2204 	if (error != 0)
2205 		return (error);
2206 	error = freebsd11_cvtstat(&sb, &osb);
2207 	if (error == 0)
2208 		error = copyout(&osb, uap->ub, sizeof(osb));
2209 	return (error);
2210 }
2211 
2212 int
2213 freebsd11_lstat(struct thread *td, struct freebsd11_lstat_args* uap)
2214 {
2215 	struct stat sb;
2216 	struct freebsd11_stat osb;
2217 	int error;
2218 
2219 	error = kern_statat(td, AT_SYMLINK_NOFOLLOW, AT_FDCWD, uap->path,
2220 	    UIO_USERSPACE, &sb, NULL);
2221 	if (error != 0)
2222 		return (error);
2223 	error = freebsd11_cvtstat(&sb, &osb);
2224 	if (error == 0)
2225 		error = copyout(&osb, uap->ub, sizeof(osb));
2226 	return (error);
2227 }
2228 
2229 int
2230 freebsd11_fhstat(struct thread *td, struct freebsd11_fhstat_args* uap)
2231 {
2232 	struct fhandle fh;
2233 	struct stat sb;
2234 	struct freebsd11_stat osb;
2235 	int error;
2236 
2237 	error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t));
2238 	if (error != 0)
2239 		return (error);
2240 	error = kern_fhstat(td, fh, &sb);
2241 	if (error != 0)
2242 		return (error);
2243 	error = freebsd11_cvtstat(&sb, &osb);
2244 	if (error == 0)
2245 		error = copyout(&osb, uap->sb, sizeof(osb));
2246 	return (error);
2247 }
2248 
2249 int
2250 freebsd11_fstatat(struct thread *td, struct freebsd11_fstatat_args* uap)
2251 {
2252 	struct stat sb;
2253 	struct freebsd11_stat osb;
2254 	int error;
2255 
2256 	error = kern_statat(td, uap->flag, uap->fd, uap->path,
2257 	    UIO_USERSPACE, &sb, NULL);
2258 	if (error != 0)
2259 		return (error);
2260 	error = freebsd11_cvtstat(&sb, &osb);
2261 	if (error == 0)
2262 		error = copyout(&osb, uap->buf, sizeof(osb));
2263 	return (error);
2264 }
2265 #endif	/* COMPAT_FREEBSD11 */
2266 
2267 /*
2268  * Get file status
2269  */
2270 #ifndef _SYS_SYSPROTO_H_
2271 struct fstatat_args {
2272 	int	fd;
2273 	char	*path;
2274 	struct stat	*buf;
2275 	int	flag;
2276 }
2277 #endif
2278 int
2279 sys_fstatat(struct thread *td, struct fstatat_args *uap)
2280 {
2281 	struct stat sb;
2282 	int error;
2283 
2284 	error = kern_statat(td, uap->flag, uap->fd, uap->path,
2285 	    UIO_USERSPACE, &sb, NULL);
2286 	if (error == 0)
2287 		error = copyout(&sb, uap->buf, sizeof (sb));
2288 	return (error);
2289 }
2290 
2291 int
2292 kern_statat(struct thread *td, int flag, int fd, const char *path,
2293     enum uio_seg pathseg, struct stat *sbp,
2294     void (*hook)(struct vnode *vp, struct stat *sbp))
2295 {
2296 	struct nameidata nd;
2297 	int error;
2298 
2299 	if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_BENEATH)) != 0)
2300 		return (EINVAL);
2301 
2302 	NDINIT_ATRIGHTS(&nd, LOOKUP, ((flag & AT_SYMLINK_NOFOLLOW) != 0 ?
2303 	    NOFOLLOW : FOLLOW) | ((flag & AT_BENEATH) != 0 ? BENEATH : 0) |
2304 	    LOCKSHARED | LOCKLEAF | AUDITVNODE1, pathseg, path, fd,
2305 	    &cap_fstat_rights, td);
2306 
2307 	if ((error = namei(&nd)) != 0)
2308 		return (error);
2309 	error = vn_stat(nd.ni_vp, sbp, td->td_ucred, NOCRED, td);
2310 	if (error == 0) {
2311 		SDT_PROBE2(vfs, , stat, mode, path, sbp->st_mode);
2312 		if (S_ISREG(sbp->st_mode))
2313 			SDT_PROBE2(vfs, , stat, reg, path, pathseg);
2314 		if (__predict_false(hook != NULL))
2315 			hook(nd.ni_vp, sbp);
2316 	}
2317 	NDFREE(&nd, NDF_ONLY_PNBUF);
2318 	vput(nd.ni_vp);
2319 	if (error != 0)
2320 		return (error);
2321 #ifdef __STAT_TIME_T_EXT
2322 	sbp->st_atim_ext = 0;
2323 	sbp->st_mtim_ext = 0;
2324 	sbp->st_ctim_ext = 0;
2325 	sbp->st_btim_ext = 0;
2326 #endif
2327 #ifdef KTRACE
2328 	if (KTRPOINT(td, KTR_STRUCT))
2329 		ktrstat(sbp);
2330 #endif
2331 	return (0);
2332 }
2333 
2334 #if defined(COMPAT_FREEBSD11)
2335 /*
2336  * Implementation of the NetBSD [l]stat() functions.
2337  */
2338 void
2339 freebsd11_cvtnstat(struct stat *sb, struct nstat *nsb)
2340 {
2341 
2342 	bzero(nsb, sizeof(*nsb));
2343 	nsb->st_dev = sb->st_dev;
2344 	nsb->st_ino = sb->st_ino;
2345 	nsb->st_mode = sb->st_mode;
2346 	nsb->st_nlink = sb->st_nlink;
2347 	nsb->st_uid = sb->st_uid;
2348 	nsb->st_gid = sb->st_gid;
2349 	nsb->st_rdev = sb->st_rdev;
2350 	nsb->st_atim = sb->st_atim;
2351 	nsb->st_mtim = sb->st_mtim;
2352 	nsb->st_ctim = sb->st_ctim;
2353 	nsb->st_size = sb->st_size;
2354 	nsb->st_blocks = sb->st_blocks;
2355 	nsb->st_blksize = sb->st_blksize;
2356 	nsb->st_flags = sb->st_flags;
2357 	nsb->st_gen = sb->st_gen;
2358 	nsb->st_birthtim = sb->st_birthtim;
2359 }
2360 
2361 #ifndef _SYS_SYSPROTO_H_
2362 struct freebsd11_nstat_args {
2363 	char	*path;
2364 	struct nstat *ub;
2365 };
2366 #endif
2367 int
2368 freebsd11_nstat(struct thread *td, struct freebsd11_nstat_args *uap)
2369 {
2370 	struct stat sb;
2371 	struct nstat nsb;
2372 	int error;
2373 
2374 	error = kern_statat(td, 0, AT_FDCWD, uap->path, UIO_USERSPACE,
2375 	    &sb, NULL);
2376 	if (error != 0)
2377 		return (error);
2378 	freebsd11_cvtnstat(&sb, &nsb);
2379 	return (copyout(&nsb, uap->ub, sizeof (nsb)));
2380 }
2381 
2382 /*
2383  * NetBSD lstat.  Get file status; this version does not follow links.
2384  */
2385 #ifndef _SYS_SYSPROTO_H_
2386 struct freebsd11_nlstat_args {
2387 	char	*path;
2388 	struct nstat *ub;
2389 };
2390 #endif
2391 int
2392 freebsd11_nlstat(struct thread *td, struct freebsd11_nlstat_args *uap)
2393 {
2394 	struct stat sb;
2395 	struct nstat nsb;
2396 	int error;
2397 
2398 	error = kern_statat(td, AT_SYMLINK_NOFOLLOW, AT_FDCWD, uap->path,
2399 	    UIO_USERSPACE, &sb, NULL);
2400 	if (error != 0)
2401 		return (error);
2402 	freebsd11_cvtnstat(&sb, &nsb);
2403 	return (copyout(&nsb, uap->ub, sizeof (nsb)));
2404 }
2405 #endif /* COMPAT_FREEBSD11 */
2406 
2407 /*
2408  * Get configurable pathname variables.
2409  */
2410 #ifndef _SYS_SYSPROTO_H_
2411 struct pathconf_args {
2412 	char	*path;
2413 	int	name;
2414 };
2415 #endif
2416 int
2417 sys_pathconf(struct thread *td, struct pathconf_args *uap)
2418 {
2419 	long value;
2420 	int error;
2421 
2422 	error = kern_pathconf(td, uap->path, UIO_USERSPACE, uap->name, FOLLOW,
2423 	    &value);
2424 	if (error == 0)
2425 		td->td_retval[0] = value;
2426 	return (error);
2427 }
2428 
2429 #ifndef _SYS_SYSPROTO_H_
2430 struct lpathconf_args {
2431 	char	*path;
2432 	int	name;
2433 };
2434 #endif
2435 int
2436 sys_lpathconf(struct thread *td, struct lpathconf_args *uap)
2437 {
2438 	long value;
2439 	int error;
2440 
2441 	error = kern_pathconf(td, uap->path, UIO_USERSPACE, uap->name,
2442 	    NOFOLLOW, &value);
2443 	if (error == 0)
2444 		td->td_retval[0] = value;
2445 	return (error);
2446 }
2447 
2448 int
2449 kern_pathconf(struct thread *td, const char *path, enum uio_seg pathseg,
2450     int name, u_long flags, long *valuep)
2451 {
2452 	struct nameidata nd;
2453 	int error;
2454 
2455 	NDINIT(&nd, LOOKUP, LOCKSHARED | LOCKLEAF | AUDITVNODE1 | flags,
2456 	    pathseg, path, td);
2457 	if ((error = namei(&nd)) != 0)
2458 		return (error);
2459 	NDFREE(&nd, NDF_ONLY_PNBUF);
2460 
2461 	error = VOP_PATHCONF(nd.ni_vp, name, valuep);
2462 	vput(nd.ni_vp);
2463 	return (error);
2464 }
2465 
2466 /*
2467  * Return target name of a symbolic link.
2468  */
2469 #ifndef _SYS_SYSPROTO_H_
2470 struct readlink_args {
2471 	char	*path;
2472 	char	*buf;
2473 	size_t	count;
2474 };
2475 #endif
2476 int
2477 sys_readlink(struct thread *td, struct readlink_args *uap)
2478 {
2479 
2480 	return (kern_readlinkat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
2481 	    uap->buf, UIO_USERSPACE, uap->count));
2482 }
2483 #ifndef _SYS_SYSPROTO_H_
2484 struct readlinkat_args {
2485 	int	fd;
2486 	char	*path;
2487 	char	*buf;
2488 	size_t	bufsize;
2489 };
2490 #endif
2491 int
2492 sys_readlinkat(struct thread *td, struct readlinkat_args *uap)
2493 {
2494 
2495 	return (kern_readlinkat(td, uap->fd, uap->path, UIO_USERSPACE,
2496 	    uap->buf, UIO_USERSPACE, uap->bufsize));
2497 }
2498 
2499 int
2500 kern_readlinkat(struct thread *td, int fd, const char *path,
2501     enum uio_seg pathseg, char *buf, enum uio_seg bufseg, size_t count)
2502 {
2503 	struct vnode *vp;
2504 	struct nameidata nd;
2505 	int error;
2506 
2507 	if (count > IOSIZE_MAX)
2508 		return (EINVAL);
2509 
2510 	NDINIT_AT(&nd, LOOKUP, NOFOLLOW | LOCKSHARED | LOCKLEAF | AUDITVNODE1,
2511 	    pathseg, path, fd, td);
2512 
2513 	if ((error = namei(&nd)) != 0)
2514 		return (error);
2515 	NDFREE(&nd, NDF_ONLY_PNBUF);
2516 	vp = nd.ni_vp;
2517 
2518 	error = kern_readlink_vp(vp, buf, bufseg, count, td);
2519 	vput(vp);
2520 
2521 	return (error);
2522 }
2523 
2524 /*
2525  * Helper function to readlink from a vnode
2526  */
2527 static int
2528 kern_readlink_vp(struct vnode *vp, char *buf, enum uio_seg bufseg, size_t count,
2529     struct thread *td)
2530 {
2531 	struct iovec aiov;
2532 	struct uio auio;
2533 	int error;
2534 
2535 	ASSERT_VOP_LOCKED(vp, "kern_readlink_vp(): vp not locked");
2536 #ifdef MAC
2537 	error = mac_vnode_check_readlink(td->td_ucred, vp);
2538 	if (error != 0)
2539 		return (error);
2540 #endif
2541 	if (vp->v_type != VLNK && (vp->v_vflag & VV_READLINK) == 0)
2542 		return (EINVAL);
2543 
2544 	aiov.iov_base = buf;
2545 	aiov.iov_len = count;
2546 	auio.uio_iov = &aiov;
2547 	auio.uio_iovcnt = 1;
2548 	auio.uio_offset = 0;
2549 	auio.uio_rw = UIO_READ;
2550 	auio.uio_segflg = bufseg;
2551 	auio.uio_td = td;
2552 	auio.uio_resid = count;
2553 	error = VOP_READLINK(vp, &auio, td->td_ucred);
2554 	td->td_retval[0] = count - auio.uio_resid;
2555 	return (error);
2556 }
2557 
2558 /*
2559  * Common implementation code for chflags() and fchflags().
2560  */
2561 static int
2562 setfflags(struct thread *td, struct vnode *vp, u_long flags)
2563 {
2564 	struct mount *mp;
2565 	struct vattr vattr;
2566 	int error;
2567 
2568 	/* We can't support the value matching VNOVAL. */
2569 	if (flags == VNOVAL)
2570 		return (EOPNOTSUPP);
2571 
2572 	/*
2573 	 * Prevent non-root users from setting flags on devices.  When
2574 	 * a device is reused, users can retain ownership of the device
2575 	 * if they are allowed to set flags and programs assume that
2576 	 * chown can't fail when done as root.
2577 	 */
2578 	if (vp->v_type == VCHR || vp->v_type == VBLK) {
2579 		error = priv_check(td, PRIV_VFS_CHFLAGS_DEV);
2580 		if (error != 0)
2581 			return (error);
2582 	}
2583 
2584 	if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
2585 		return (error);
2586 	VATTR_NULL(&vattr);
2587 	vattr.va_flags = flags;
2588 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2589 #ifdef MAC
2590 	error = mac_vnode_check_setflags(td->td_ucred, vp, vattr.va_flags);
2591 	if (error == 0)
2592 #endif
2593 		error = VOP_SETATTR(vp, &vattr, td->td_ucred);
2594 	VOP_UNLOCK(vp, 0);
2595 	vn_finished_write(mp);
2596 	return (error);
2597 }
2598 
2599 /*
2600  * Change flags of a file given a path name.
2601  */
2602 #ifndef _SYS_SYSPROTO_H_
2603 struct chflags_args {
2604 	const char *path;
2605 	u_long	flags;
2606 };
2607 #endif
2608 int
2609 sys_chflags(struct thread *td, struct chflags_args *uap)
2610 {
2611 
2612 	return (kern_chflagsat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
2613 	    uap->flags, 0));
2614 }
2615 
2616 #ifndef _SYS_SYSPROTO_H_
2617 struct chflagsat_args {
2618 	int	fd;
2619 	const char *path;
2620 	u_long	flags;
2621 	int	atflag;
2622 }
2623 #endif
2624 int
2625 sys_chflagsat(struct thread *td, struct chflagsat_args *uap)
2626 {
2627 
2628 	if ((uap->atflag & ~(AT_SYMLINK_NOFOLLOW | AT_BENEATH)) != 0)
2629 		return (EINVAL);
2630 
2631 	return (kern_chflagsat(td, uap->fd, uap->path, UIO_USERSPACE,
2632 	    uap->flags, uap->atflag));
2633 }
2634 
2635 /*
2636  * Same as chflags() but doesn't follow symlinks.
2637  */
2638 #ifndef _SYS_SYSPROTO_H_
2639 struct lchflags_args {
2640 	const char *path;
2641 	u_long flags;
2642 };
2643 #endif
2644 int
2645 sys_lchflags(struct thread *td, struct lchflags_args *uap)
2646 {
2647 
2648 	return (kern_chflagsat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
2649 	    uap->flags, AT_SYMLINK_NOFOLLOW));
2650 }
2651 
2652 static int
2653 kern_chflagsat(struct thread *td, int fd, const char *path,
2654     enum uio_seg pathseg, u_long flags, int atflag)
2655 {
2656 	struct nameidata nd;
2657 	int error, follow;
2658 
2659 	AUDIT_ARG_FFLAGS(flags);
2660 	follow = (atflag & AT_SYMLINK_NOFOLLOW) ? NOFOLLOW : FOLLOW;
2661 	follow |= (atflag & AT_BENEATH) != 0 ? BENEATH : 0;
2662 	NDINIT_ATRIGHTS(&nd, LOOKUP, follow | AUDITVNODE1, pathseg, path, fd,
2663 	    &cap_fchflags_rights, td);
2664 	if ((error = namei(&nd)) != 0)
2665 		return (error);
2666 	NDFREE(&nd, NDF_ONLY_PNBUF);
2667 	error = setfflags(td, nd.ni_vp, flags);
2668 	vrele(nd.ni_vp);
2669 	return (error);
2670 }
2671 
2672 /*
2673  * Change flags of a file given a file descriptor.
2674  */
2675 #ifndef _SYS_SYSPROTO_H_
2676 struct fchflags_args {
2677 	int	fd;
2678 	u_long	flags;
2679 };
2680 #endif
2681 int
2682 sys_fchflags(struct thread *td, struct fchflags_args *uap)
2683 {
2684 	struct file *fp;
2685 	int error;
2686 
2687 	AUDIT_ARG_FD(uap->fd);
2688 	AUDIT_ARG_FFLAGS(uap->flags);
2689 	error = getvnode(td, uap->fd, &cap_fchflags_rights,
2690 	    &fp);
2691 	if (error != 0)
2692 		return (error);
2693 #ifdef AUDIT
2694 	vn_lock(fp->f_vnode, LK_SHARED | LK_RETRY);
2695 	AUDIT_ARG_VNODE1(fp->f_vnode);
2696 	VOP_UNLOCK(fp->f_vnode, 0);
2697 #endif
2698 	error = setfflags(td, fp->f_vnode, uap->flags);
2699 	fdrop(fp, td);
2700 	return (error);
2701 }
2702 
2703 /*
2704  * Common implementation code for chmod(), lchmod() and fchmod().
2705  */
2706 int
2707 setfmode(struct thread *td, struct ucred *cred, struct vnode *vp, int mode)
2708 {
2709 	struct mount *mp;
2710 	struct vattr vattr;
2711 	int error;
2712 
2713 	if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
2714 		return (error);
2715 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2716 	VATTR_NULL(&vattr);
2717 	vattr.va_mode = mode & ALLPERMS;
2718 #ifdef MAC
2719 	error = mac_vnode_check_setmode(cred, vp, vattr.va_mode);
2720 	if (error == 0)
2721 #endif
2722 		error = VOP_SETATTR(vp, &vattr, cred);
2723 	VOP_UNLOCK(vp, 0);
2724 	vn_finished_write(mp);
2725 	return (error);
2726 }
2727 
2728 /*
2729  * Change mode of a file given path name.
2730  */
2731 #ifndef _SYS_SYSPROTO_H_
2732 struct chmod_args {
2733 	char	*path;
2734 	int	mode;
2735 };
2736 #endif
2737 int
2738 sys_chmod(struct thread *td, struct chmod_args *uap)
2739 {
2740 
2741 	return (kern_fchmodat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
2742 	    uap->mode, 0));
2743 }
2744 
2745 #ifndef _SYS_SYSPROTO_H_
2746 struct fchmodat_args {
2747 	int	dirfd;
2748 	char	*path;
2749 	mode_t	mode;
2750 	int	flag;
2751 }
2752 #endif
2753 int
2754 sys_fchmodat(struct thread *td, struct fchmodat_args *uap)
2755 {
2756 
2757 	if ((uap->flag & ~(AT_SYMLINK_NOFOLLOW | AT_BENEATH)) != 0)
2758 		return (EINVAL);
2759 
2760 	return (kern_fchmodat(td, uap->fd, uap->path, UIO_USERSPACE,
2761 	    uap->mode, uap->flag));
2762 }
2763 
2764 /*
2765  * Change mode of a file given path name (don't follow links.)
2766  */
2767 #ifndef _SYS_SYSPROTO_H_
2768 struct lchmod_args {
2769 	char	*path;
2770 	int	mode;
2771 };
2772 #endif
2773 int
2774 sys_lchmod(struct thread *td, struct lchmod_args *uap)
2775 {
2776 
2777 	return (kern_fchmodat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
2778 	    uap->mode, AT_SYMLINK_NOFOLLOW));
2779 }
2780 
2781 int
2782 kern_fchmodat(struct thread *td, int fd, const char *path,
2783     enum uio_seg pathseg, mode_t mode, int flag)
2784 {
2785 	struct nameidata nd;
2786 	int error, follow;
2787 
2788 	AUDIT_ARG_MODE(mode);
2789 	follow = (flag & AT_SYMLINK_NOFOLLOW) != 0 ? NOFOLLOW : FOLLOW;
2790 	follow |= (flag & AT_BENEATH) != 0 ? BENEATH : 0;
2791 	NDINIT_ATRIGHTS(&nd, LOOKUP, follow | AUDITVNODE1, pathseg, path, fd,
2792 	    &cap_fchmod_rights, td);
2793 	if ((error = namei(&nd)) != 0)
2794 		return (error);
2795 	NDFREE(&nd, NDF_ONLY_PNBUF);
2796 	error = setfmode(td, td->td_ucred, nd.ni_vp, mode);
2797 	vrele(nd.ni_vp);
2798 	return (error);
2799 }
2800 
2801 /*
2802  * Change mode of a file given a file descriptor.
2803  */
2804 #ifndef _SYS_SYSPROTO_H_
2805 struct fchmod_args {
2806 	int	fd;
2807 	int	mode;
2808 };
2809 #endif
2810 int
2811 sys_fchmod(struct thread *td, struct fchmod_args *uap)
2812 {
2813 	struct file *fp;
2814 	int error;
2815 
2816 	AUDIT_ARG_FD(uap->fd);
2817 	AUDIT_ARG_MODE(uap->mode);
2818 
2819 	error = fget(td, uap->fd, &cap_fchmod_rights, &fp);
2820 	if (error != 0)
2821 		return (error);
2822 	error = fo_chmod(fp, uap->mode, td->td_ucred, td);
2823 	fdrop(fp, td);
2824 	return (error);
2825 }
2826 
2827 /*
2828  * Common implementation for chown(), lchown(), and fchown()
2829  */
2830 int
2831 setfown(struct thread *td, struct ucred *cred, struct vnode *vp, uid_t uid,
2832     gid_t gid)
2833 {
2834 	struct mount *mp;
2835 	struct vattr vattr;
2836 	int error;
2837 
2838 	if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
2839 		return (error);
2840 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2841 	VATTR_NULL(&vattr);
2842 	vattr.va_uid = uid;
2843 	vattr.va_gid = gid;
2844 #ifdef MAC
2845 	error = mac_vnode_check_setowner(cred, vp, vattr.va_uid,
2846 	    vattr.va_gid);
2847 	if (error == 0)
2848 #endif
2849 		error = VOP_SETATTR(vp, &vattr, cred);
2850 	VOP_UNLOCK(vp, 0);
2851 	vn_finished_write(mp);
2852 	return (error);
2853 }
2854 
2855 /*
2856  * Set ownership given a path name.
2857  */
2858 #ifndef _SYS_SYSPROTO_H_
2859 struct chown_args {
2860 	char	*path;
2861 	int	uid;
2862 	int	gid;
2863 };
2864 #endif
2865 int
2866 sys_chown(struct thread *td, struct chown_args *uap)
2867 {
2868 
2869 	return (kern_fchownat(td, AT_FDCWD, uap->path, UIO_USERSPACE, uap->uid,
2870 	    uap->gid, 0));
2871 }
2872 
2873 #ifndef _SYS_SYSPROTO_H_
2874 struct fchownat_args {
2875 	int fd;
2876 	const char * path;
2877 	uid_t uid;
2878 	gid_t gid;
2879 	int flag;
2880 };
2881 #endif
2882 int
2883 sys_fchownat(struct thread *td, struct fchownat_args *uap)
2884 {
2885 
2886 	if ((uap->flag & ~(AT_SYMLINK_NOFOLLOW | AT_BENEATH)) != 0)
2887 		return (EINVAL);
2888 
2889 	return (kern_fchownat(td, uap->fd, uap->path, UIO_USERSPACE, uap->uid,
2890 	    uap->gid, uap->flag));
2891 }
2892 
2893 int
2894 kern_fchownat(struct thread *td, int fd, const char *path,
2895     enum uio_seg pathseg, int uid, int gid, int flag)
2896 {
2897 	struct nameidata nd;
2898 	int error, follow;
2899 
2900 	AUDIT_ARG_OWNER(uid, gid);
2901 	follow = (flag & AT_SYMLINK_NOFOLLOW) ? NOFOLLOW : FOLLOW;
2902 	follow |= (flag & AT_BENEATH) != 0 ? BENEATH : 0;
2903 	NDINIT_ATRIGHTS(&nd, LOOKUP, follow | AUDITVNODE1, pathseg, path, fd,
2904 	    &cap_fchown_rights, td);
2905 
2906 	if ((error = namei(&nd)) != 0)
2907 		return (error);
2908 	NDFREE(&nd, NDF_ONLY_PNBUF);
2909 	error = setfown(td, td->td_ucred, nd.ni_vp, uid, gid);
2910 	vrele(nd.ni_vp);
2911 	return (error);
2912 }
2913 
2914 /*
2915  * Set ownership given a path name, do not cross symlinks.
2916  */
2917 #ifndef _SYS_SYSPROTO_H_
2918 struct lchown_args {
2919 	char	*path;
2920 	int	uid;
2921 	int	gid;
2922 };
2923 #endif
2924 int
2925 sys_lchown(struct thread *td, struct lchown_args *uap)
2926 {
2927 
2928 	return (kern_fchownat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
2929 	    uap->uid, uap->gid, AT_SYMLINK_NOFOLLOW));
2930 }
2931 
2932 /*
2933  * Set ownership given a file descriptor.
2934  */
2935 #ifndef _SYS_SYSPROTO_H_
2936 struct fchown_args {
2937 	int	fd;
2938 	int	uid;
2939 	int	gid;
2940 };
2941 #endif
2942 int
2943 sys_fchown(struct thread *td, struct fchown_args *uap)
2944 {
2945 	struct file *fp;
2946 	int error;
2947 
2948 	AUDIT_ARG_FD(uap->fd);
2949 	AUDIT_ARG_OWNER(uap->uid, uap->gid);
2950 	error = fget(td, uap->fd, &cap_fchown_rights, &fp);
2951 	if (error != 0)
2952 		return (error);
2953 	error = fo_chown(fp, uap->uid, uap->gid, td->td_ucred, td);
2954 	fdrop(fp, td);
2955 	return (error);
2956 }
2957 
2958 /*
2959  * Common implementation code for utimes(), lutimes(), and futimes().
2960  */
2961 static int
2962 getutimes(const struct timeval *usrtvp, enum uio_seg tvpseg,
2963     struct timespec *tsp)
2964 {
2965 	struct timeval tv[2];
2966 	const struct timeval *tvp;
2967 	int error;
2968 
2969 	if (usrtvp == NULL) {
2970 		vfs_timestamp(&tsp[0]);
2971 		tsp[1] = tsp[0];
2972 	} else {
2973 		if (tvpseg == UIO_SYSSPACE) {
2974 			tvp = usrtvp;
2975 		} else {
2976 			if ((error = copyin(usrtvp, tv, sizeof(tv))) != 0)
2977 				return (error);
2978 			tvp = tv;
2979 		}
2980 
2981 		if (tvp[0].tv_usec < 0 || tvp[0].tv_usec >= 1000000 ||
2982 		    tvp[1].tv_usec < 0 || tvp[1].tv_usec >= 1000000)
2983 			return (EINVAL);
2984 		TIMEVAL_TO_TIMESPEC(&tvp[0], &tsp[0]);
2985 		TIMEVAL_TO_TIMESPEC(&tvp[1], &tsp[1]);
2986 	}
2987 	return (0);
2988 }
2989 
2990 /*
2991  * Common implementation code for futimens(), utimensat().
2992  */
2993 #define	UTIMENS_NULL	0x1
2994 #define	UTIMENS_EXIT	0x2
2995 static int
2996 getutimens(const struct timespec *usrtsp, enum uio_seg tspseg,
2997     struct timespec *tsp, int *retflags)
2998 {
2999 	struct timespec tsnow;
3000 	int error;
3001 
3002 	vfs_timestamp(&tsnow);
3003 	*retflags = 0;
3004 	if (usrtsp == NULL) {
3005 		tsp[0] = tsnow;
3006 		tsp[1] = tsnow;
3007 		*retflags |= UTIMENS_NULL;
3008 		return (0);
3009 	}
3010 	if (tspseg == UIO_SYSSPACE) {
3011 		tsp[0] = usrtsp[0];
3012 		tsp[1] = usrtsp[1];
3013 	} else if ((error = copyin(usrtsp, tsp, sizeof(*tsp) * 2)) != 0)
3014 		return (error);
3015 	if (tsp[0].tv_nsec == UTIME_OMIT && tsp[1].tv_nsec == UTIME_OMIT)
3016 		*retflags |= UTIMENS_EXIT;
3017 	if (tsp[0].tv_nsec == UTIME_NOW && tsp[1].tv_nsec == UTIME_NOW)
3018 		*retflags |= UTIMENS_NULL;
3019 	if (tsp[0].tv_nsec == UTIME_OMIT)
3020 		tsp[0].tv_sec = VNOVAL;
3021 	else if (tsp[0].tv_nsec == UTIME_NOW)
3022 		tsp[0] = tsnow;
3023 	else if (tsp[0].tv_nsec < 0 || tsp[0].tv_nsec >= 1000000000L)
3024 		return (EINVAL);
3025 	if (tsp[1].tv_nsec == UTIME_OMIT)
3026 		tsp[1].tv_sec = VNOVAL;
3027 	else if (tsp[1].tv_nsec == UTIME_NOW)
3028 		tsp[1] = tsnow;
3029 	else if (tsp[1].tv_nsec < 0 || tsp[1].tv_nsec >= 1000000000L)
3030 		return (EINVAL);
3031 
3032 	return (0);
3033 }
3034 
3035 /*
3036  * Common implementation code for utimes(), lutimes(), futimes(), futimens(),
3037  * and utimensat().
3038  */
3039 static int
3040 setutimes(struct thread *td, struct vnode *vp, const struct timespec *ts,
3041     int numtimes, int nullflag)
3042 {
3043 	struct mount *mp;
3044 	struct vattr vattr;
3045 	int error, setbirthtime;
3046 
3047 	if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0)
3048 		return (error);
3049 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3050 	setbirthtime = 0;
3051 	if (numtimes < 3 && !VOP_GETATTR(vp, &vattr, td->td_ucred) &&
3052 	    timespeccmp(&ts[1], &vattr.va_birthtime, < ))
3053 		setbirthtime = 1;
3054 	VATTR_NULL(&vattr);
3055 	vattr.va_atime = ts[0];
3056 	vattr.va_mtime = ts[1];
3057 	if (setbirthtime)
3058 		vattr.va_birthtime = ts[1];
3059 	if (numtimes > 2)
3060 		vattr.va_birthtime = ts[2];
3061 	if (nullflag)
3062 		vattr.va_vaflags |= VA_UTIMES_NULL;
3063 #ifdef MAC
3064 	error = mac_vnode_check_setutimes(td->td_ucred, vp, vattr.va_atime,
3065 	    vattr.va_mtime);
3066 #endif
3067 	if (error == 0)
3068 		error = VOP_SETATTR(vp, &vattr, td->td_ucred);
3069 	VOP_UNLOCK(vp, 0);
3070 	vn_finished_write(mp);
3071 	return (error);
3072 }
3073 
3074 /*
3075  * Set the access and modification times of a file.
3076  */
3077 #ifndef _SYS_SYSPROTO_H_
3078 struct utimes_args {
3079 	char	*path;
3080 	struct	timeval *tptr;
3081 };
3082 #endif
3083 int
3084 sys_utimes(struct thread *td, struct utimes_args *uap)
3085 {
3086 
3087 	return (kern_utimesat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
3088 	    uap->tptr, UIO_USERSPACE));
3089 }
3090 
3091 #ifndef _SYS_SYSPROTO_H_
3092 struct futimesat_args {
3093 	int fd;
3094 	const char * path;
3095 	const struct timeval * times;
3096 };
3097 #endif
3098 int
3099 sys_futimesat(struct thread *td, struct futimesat_args *uap)
3100 {
3101 
3102 	return (kern_utimesat(td, uap->fd, uap->path, UIO_USERSPACE,
3103 	    uap->times, UIO_USERSPACE));
3104 }
3105 
3106 int
3107 kern_utimesat(struct thread *td, int fd, const char *path,
3108     enum uio_seg pathseg, struct timeval *tptr, enum uio_seg tptrseg)
3109 {
3110 	struct nameidata nd;
3111 	struct timespec ts[2];
3112 	int error;
3113 
3114 	if ((error = getutimes(tptr, tptrseg, ts)) != 0)
3115 		return (error);
3116 	NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | AUDITVNODE1, pathseg, path, fd,
3117 	    &cap_futimes_rights, td);
3118 
3119 	if ((error = namei(&nd)) != 0)
3120 		return (error);
3121 	NDFREE(&nd, NDF_ONLY_PNBUF);
3122 	error = setutimes(td, nd.ni_vp, ts, 2, tptr == NULL);
3123 	vrele(nd.ni_vp);
3124 	return (error);
3125 }
3126 
3127 /*
3128  * Set the access and modification times of a file.
3129  */
3130 #ifndef _SYS_SYSPROTO_H_
3131 struct lutimes_args {
3132 	char	*path;
3133 	struct	timeval *tptr;
3134 };
3135 #endif
3136 int
3137 sys_lutimes(struct thread *td, struct lutimes_args *uap)
3138 {
3139 
3140 	return (kern_lutimes(td, uap->path, UIO_USERSPACE, uap->tptr,
3141 	    UIO_USERSPACE));
3142 }
3143 
3144 int
3145 kern_lutimes(struct thread *td, const char *path, enum uio_seg pathseg,
3146     struct timeval *tptr, enum uio_seg tptrseg)
3147 {
3148 	struct timespec ts[2];
3149 	struct nameidata nd;
3150 	int error;
3151 
3152 	if ((error = getutimes(tptr, tptrseg, ts)) != 0)
3153 		return (error);
3154 	NDINIT(&nd, LOOKUP, NOFOLLOW | AUDITVNODE1, pathseg, path, td);
3155 	if ((error = namei(&nd)) != 0)
3156 		return (error);
3157 	NDFREE(&nd, NDF_ONLY_PNBUF);
3158 	error = setutimes(td, nd.ni_vp, ts, 2, tptr == NULL);
3159 	vrele(nd.ni_vp);
3160 	return (error);
3161 }
3162 
3163 /*
3164  * Set the access and modification times of a file.
3165  */
3166 #ifndef _SYS_SYSPROTO_H_
3167 struct futimes_args {
3168 	int	fd;
3169 	struct	timeval *tptr;
3170 };
3171 #endif
3172 int
3173 sys_futimes(struct thread *td, struct futimes_args *uap)
3174 {
3175 
3176 	return (kern_futimes(td, uap->fd, uap->tptr, UIO_USERSPACE));
3177 }
3178 
3179 int
3180 kern_futimes(struct thread *td, int fd, struct timeval *tptr,
3181     enum uio_seg tptrseg)
3182 {
3183 	struct timespec ts[2];
3184 	struct file *fp;
3185 	int error;
3186 
3187 	AUDIT_ARG_FD(fd);
3188 	error = getutimes(tptr, tptrseg, ts);
3189 	if (error != 0)
3190 		return (error);
3191 	error = getvnode(td, fd, &cap_futimes_rights, &fp);
3192 	if (error != 0)
3193 		return (error);
3194 #ifdef AUDIT
3195 	vn_lock(fp->f_vnode, LK_SHARED | LK_RETRY);
3196 	AUDIT_ARG_VNODE1(fp->f_vnode);
3197 	VOP_UNLOCK(fp->f_vnode, 0);
3198 #endif
3199 	error = setutimes(td, fp->f_vnode, ts, 2, tptr == NULL);
3200 	fdrop(fp, td);
3201 	return (error);
3202 }
3203 
3204 int
3205 sys_futimens(struct thread *td, struct futimens_args *uap)
3206 {
3207 
3208 	return (kern_futimens(td, uap->fd, uap->times, UIO_USERSPACE));
3209 }
3210 
3211 int
3212 kern_futimens(struct thread *td, int fd, struct timespec *tptr,
3213     enum uio_seg tptrseg)
3214 {
3215 	struct timespec ts[2];
3216 	struct file *fp;
3217 	int error, flags;
3218 
3219 	AUDIT_ARG_FD(fd);
3220 	error = getutimens(tptr, tptrseg, ts, &flags);
3221 	if (error != 0)
3222 		return (error);
3223 	if (flags & UTIMENS_EXIT)
3224 		return (0);
3225 	error = getvnode(td, fd, &cap_futimes_rights, &fp);
3226 	if (error != 0)
3227 		return (error);
3228 #ifdef AUDIT
3229 	vn_lock(fp->f_vnode, LK_SHARED | LK_RETRY);
3230 	AUDIT_ARG_VNODE1(fp->f_vnode);
3231 	VOP_UNLOCK(fp->f_vnode, 0);
3232 #endif
3233 	error = setutimes(td, fp->f_vnode, ts, 2, flags & UTIMENS_NULL);
3234 	fdrop(fp, td);
3235 	return (error);
3236 }
3237 
3238 int
3239 sys_utimensat(struct thread *td, struct utimensat_args *uap)
3240 {
3241 
3242 	return (kern_utimensat(td, uap->fd, uap->path, UIO_USERSPACE,
3243 	    uap->times, UIO_USERSPACE, uap->flag));
3244 }
3245 
3246 int
3247 kern_utimensat(struct thread *td, int fd, const char *path,
3248     enum uio_seg pathseg, struct timespec *tptr, enum uio_seg tptrseg,
3249     int flag)
3250 {
3251 	struct nameidata nd;
3252 	struct timespec ts[2];
3253 	int error, flags;
3254 
3255 	if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_BENEATH)) != 0)
3256 		return (EINVAL);
3257 
3258 	if ((error = getutimens(tptr, tptrseg, ts, &flags)) != 0)
3259 		return (error);
3260 	NDINIT_ATRIGHTS(&nd, LOOKUP, ((flag & AT_SYMLINK_NOFOLLOW) ? NOFOLLOW :
3261 	    FOLLOW) |  ((flag & AT_BENEATH) != 0 ? BENEATH : 0) | AUDITVNODE1,
3262 	    pathseg, path, fd, &cap_futimes_rights, td);
3263 	if ((error = namei(&nd)) != 0)
3264 		return (error);
3265 	/*
3266 	 * We are allowed to call namei() regardless of 2xUTIME_OMIT.
3267 	 * POSIX states:
3268 	 * "If both tv_nsec fields are UTIME_OMIT... EACCESS may be detected."
3269 	 * "Search permission is denied by a component of the path prefix."
3270 	 */
3271 	NDFREE(&nd, NDF_ONLY_PNBUF);
3272 	if ((flags & UTIMENS_EXIT) == 0)
3273 		error = setutimes(td, nd.ni_vp, ts, 2, flags & UTIMENS_NULL);
3274 	vrele(nd.ni_vp);
3275 	return (error);
3276 }
3277 
3278 /*
3279  * Truncate a file given its path name.
3280  */
3281 #ifndef _SYS_SYSPROTO_H_
3282 struct truncate_args {
3283 	char	*path;
3284 	int	pad;
3285 	off_t	length;
3286 };
3287 #endif
3288 int
3289 sys_truncate(struct thread *td, struct truncate_args *uap)
3290 {
3291 
3292 	return (kern_truncate(td, uap->path, UIO_USERSPACE, uap->length));
3293 }
3294 
3295 int
3296 kern_truncate(struct thread *td, const char *path, enum uio_seg pathseg,
3297     off_t length)
3298 {
3299 	struct mount *mp;
3300 	struct vnode *vp;
3301 	void *rl_cookie;
3302 	struct vattr vattr;
3303 	struct nameidata nd;
3304 	int error;
3305 
3306 	if (length < 0)
3307 		return(EINVAL);
3308 	NDINIT(&nd, LOOKUP, FOLLOW | AUDITVNODE1, pathseg, path, td);
3309 	if ((error = namei(&nd)) != 0)
3310 		return (error);
3311 	vp = nd.ni_vp;
3312 	rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
3313 	if ((error = vn_start_write(vp, &mp, V_WAIT | PCATCH)) != 0) {
3314 		vn_rangelock_unlock(vp, rl_cookie);
3315 		vrele(vp);
3316 		return (error);
3317 	}
3318 	NDFREE(&nd, NDF_ONLY_PNBUF);
3319 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3320 	if (vp->v_type == VDIR)
3321 		error = EISDIR;
3322 #ifdef MAC
3323 	else if ((error = mac_vnode_check_write(td->td_ucred, NOCRED, vp))) {
3324 	}
3325 #endif
3326 	else if ((error = vn_writechk(vp)) == 0 &&
3327 	    (error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td)) == 0) {
3328 		VATTR_NULL(&vattr);
3329 		vattr.va_size = length;
3330 		error = VOP_SETATTR(vp, &vattr, td->td_ucred);
3331 	}
3332 	VOP_UNLOCK(vp, 0);
3333 	vn_finished_write(mp);
3334 	vn_rangelock_unlock(vp, rl_cookie);
3335 	vrele(vp);
3336 	return (error);
3337 }
3338 
3339 #if defined(COMPAT_43)
3340 /*
3341  * Truncate a file given its path name.
3342  */
3343 #ifndef _SYS_SYSPROTO_H_
3344 struct otruncate_args {
3345 	char	*path;
3346 	long	length;
3347 };
3348 #endif
3349 int
3350 otruncate(struct thread *td, struct otruncate_args *uap)
3351 {
3352 
3353 	return (kern_truncate(td, uap->path, UIO_USERSPACE, uap->length));
3354 }
3355 #endif /* COMPAT_43 */
3356 
3357 #if defined(COMPAT_FREEBSD6)
3358 /* Versions with the pad argument */
3359 int
3360 freebsd6_truncate(struct thread *td, struct freebsd6_truncate_args *uap)
3361 {
3362 
3363 	return (kern_truncate(td, uap->path, UIO_USERSPACE, uap->length));
3364 }
3365 
3366 int
3367 freebsd6_ftruncate(struct thread *td, struct freebsd6_ftruncate_args *uap)
3368 {
3369 
3370 	return (kern_ftruncate(td, uap->fd, uap->length));
3371 }
3372 #endif
3373 
3374 int
3375 kern_fsync(struct thread *td, int fd, bool fullsync)
3376 {
3377 	struct vnode *vp;
3378 	struct mount *mp;
3379 	struct file *fp;
3380 	int error, lock_flags;
3381 
3382 	AUDIT_ARG_FD(fd);
3383 	error = getvnode(td, fd, &cap_fsync_rights, &fp);
3384 	if (error != 0)
3385 		return (error);
3386 	vp = fp->f_vnode;
3387 #if 0
3388 	if (!fullsync)
3389 		/* XXXKIB: compete outstanding aio writes */;
3390 #endif
3391 	error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
3392 	if (error != 0)
3393 		goto drop;
3394 	if (MNT_SHARED_WRITES(mp) ||
3395 	    ((mp == NULL) && MNT_SHARED_WRITES(vp->v_mount))) {
3396 		lock_flags = LK_SHARED;
3397 	} else {
3398 		lock_flags = LK_EXCLUSIVE;
3399 	}
3400 	vn_lock(vp, lock_flags | LK_RETRY);
3401 	AUDIT_ARG_VNODE1(vp);
3402 	if (vp->v_object != NULL) {
3403 		VM_OBJECT_WLOCK(vp->v_object);
3404 		vm_object_page_clean(vp->v_object, 0, 0, 0);
3405 		VM_OBJECT_WUNLOCK(vp->v_object);
3406 	}
3407 	error = fullsync ? VOP_FSYNC(vp, MNT_WAIT, td) : VOP_FDATASYNC(vp, td);
3408 	VOP_UNLOCK(vp, 0);
3409 	vn_finished_write(mp);
3410 drop:
3411 	fdrop(fp, td);
3412 	return (error);
3413 }
3414 
3415 /*
3416  * Sync an open file.
3417  */
3418 #ifndef _SYS_SYSPROTO_H_
3419 struct fsync_args {
3420 	int	fd;
3421 };
3422 #endif
3423 int
3424 sys_fsync(struct thread *td, struct fsync_args *uap)
3425 {
3426 
3427 	return (kern_fsync(td, uap->fd, true));
3428 }
3429 
3430 int
3431 sys_fdatasync(struct thread *td, struct fdatasync_args *uap)
3432 {
3433 
3434 	return (kern_fsync(td, uap->fd, false));
3435 }
3436 
3437 /*
3438  * Rename files.  Source and destination must either both be directories, or
3439  * both not be directories.  If target is a directory, it must be empty.
3440  */
3441 #ifndef _SYS_SYSPROTO_H_
3442 struct rename_args {
3443 	char	*from;
3444 	char	*to;
3445 };
3446 #endif
3447 int
3448 sys_rename(struct thread *td, struct rename_args *uap)
3449 {
3450 
3451 	return (kern_renameat(td, AT_FDCWD, uap->from, AT_FDCWD,
3452 	    uap->to, UIO_USERSPACE));
3453 }
3454 
3455 #ifndef _SYS_SYSPROTO_H_
3456 struct renameat_args {
3457 	int	oldfd;
3458 	char	*old;
3459 	int	newfd;
3460 	char	*new;
3461 };
3462 #endif
3463 int
3464 sys_renameat(struct thread *td, struct renameat_args *uap)
3465 {
3466 
3467 	return (kern_renameat(td, uap->oldfd, uap->old, uap->newfd, uap->new,
3468 	    UIO_USERSPACE));
3469 }
3470 
3471 int
3472 kern_renameat(struct thread *td, int oldfd, const char *old, int newfd,
3473     const char *new, enum uio_seg pathseg)
3474 {
3475 	struct mount *mp = NULL;
3476 	struct vnode *tvp, *fvp, *tdvp;
3477 	struct nameidata fromnd, tond;
3478 	int error;
3479 
3480 again:
3481 	bwillwrite();
3482 #ifdef MAC
3483 	NDINIT_ATRIGHTS(&fromnd, DELETE, LOCKPARENT | LOCKLEAF | SAVESTART |
3484 	    AUDITVNODE1, pathseg, old, oldfd,
3485 	    &cap_renameat_source_rights, td);
3486 #else
3487 	NDINIT_ATRIGHTS(&fromnd, DELETE, WANTPARENT | SAVESTART | AUDITVNODE1,
3488 	    pathseg, old, oldfd,
3489 	    &cap_renameat_source_rights, td);
3490 #endif
3491 
3492 	if ((error = namei(&fromnd)) != 0)
3493 		return (error);
3494 #ifdef MAC
3495 	error = mac_vnode_check_rename_from(td->td_ucred, fromnd.ni_dvp,
3496 	    fromnd.ni_vp, &fromnd.ni_cnd);
3497 	VOP_UNLOCK(fromnd.ni_dvp, 0);
3498 	if (fromnd.ni_dvp != fromnd.ni_vp)
3499 		VOP_UNLOCK(fromnd.ni_vp, 0);
3500 #endif
3501 	fvp = fromnd.ni_vp;
3502 	NDINIT_ATRIGHTS(&tond, RENAME, LOCKPARENT | LOCKLEAF | NOCACHE |
3503 	    SAVESTART | AUDITVNODE2, pathseg, new, newfd,
3504 	    &cap_renameat_target_rights, td);
3505 	if (fromnd.ni_vp->v_type == VDIR)
3506 		tond.ni_cnd.cn_flags |= WILLBEDIR;
3507 	if ((error = namei(&tond)) != 0) {
3508 		/* Translate error code for rename("dir1", "dir2/."). */
3509 		if (error == EISDIR && fvp->v_type == VDIR)
3510 			error = EINVAL;
3511 		NDFREE(&fromnd, NDF_ONLY_PNBUF);
3512 		vrele(fromnd.ni_dvp);
3513 		vrele(fvp);
3514 		goto out1;
3515 	}
3516 	tdvp = tond.ni_dvp;
3517 	tvp = tond.ni_vp;
3518 	error = vn_start_write(fvp, &mp, V_NOWAIT);
3519 	if (error != 0) {
3520 		NDFREE(&fromnd, NDF_ONLY_PNBUF);
3521 		NDFREE(&tond, NDF_ONLY_PNBUF);
3522 		if (tvp != NULL)
3523 			vput(tvp);
3524 		if (tdvp == tvp)
3525 			vrele(tdvp);
3526 		else
3527 			vput(tdvp);
3528 		vrele(fromnd.ni_dvp);
3529 		vrele(fvp);
3530 		vrele(tond.ni_startdir);
3531 		if (fromnd.ni_startdir != NULL)
3532 			vrele(fromnd.ni_startdir);
3533 		error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH);
3534 		if (error != 0)
3535 			return (error);
3536 		goto again;
3537 	}
3538 	if (tvp != NULL) {
3539 		if (fvp->v_type == VDIR && tvp->v_type != VDIR) {
3540 			error = ENOTDIR;
3541 			goto out;
3542 		} else if (fvp->v_type != VDIR && tvp->v_type == VDIR) {
3543 			error = EISDIR;
3544 			goto out;
3545 		}
3546 #ifdef CAPABILITIES
3547 		if (newfd != AT_FDCWD && (tond.ni_resflags & NIRES_ABS) == 0) {
3548 			/*
3549 			 * If the target already exists we require CAP_UNLINKAT
3550 			 * from 'newfd', when newfd was used for the lookup.
3551 			 */
3552 			error = cap_check(&tond.ni_filecaps.fc_rights,
3553 			    &cap_unlinkat_rights);
3554 			if (error != 0)
3555 				goto out;
3556 		}
3557 #endif
3558 	}
3559 	if (fvp == tdvp) {
3560 		error = EINVAL;
3561 		goto out;
3562 	}
3563 	/*
3564 	 * If the source is the same as the destination (that is, if they
3565 	 * are links to the same vnode), then there is nothing to do.
3566 	 */
3567 	if (fvp == tvp)
3568 		error = -1;
3569 #ifdef MAC
3570 	else
3571 		error = mac_vnode_check_rename_to(td->td_ucred, tdvp,
3572 		    tond.ni_vp, fromnd.ni_dvp == tdvp, &tond.ni_cnd);
3573 #endif
3574 out:
3575 	if (error == 0) {
3576 		error = VOP_RENAME(fromnd.ni_dvp, fromnd.ni_vp, &fromnd.ni_cnd,
3577 		    tond.ni_dvp, tond.ni_vp, &tond.ni_cnd);
3578 		NDFREE(&fromnd, NDF_ONLY_PNBUF);
3579 		NDFREE(&tond, NDF_ONLY_PNBUF);
3580 	} else {
3581 		NDFREE(&fromnd, NDF_ONLY_PNBUF);
3582 		NDFREE(&tond, NDF_ONLY_PNBUF);
3583 		if (tvp != NULL)
3584 			vput(tvp);
3585 		if (tdvp == tvp)
3586 			vrele(tdvp);
3587 		else
3588 			vput(tdvp);
3589 		vrele(fromnd.ni_dvp);
3590 		vrele(fvp);
3591 	}
3592 	vrele(tond.ni_startdir);
3593 	vn_finished_write(mp);
3594 out1:
3595 	if (fromnd.ni_startdir)
3596 		vrele(fromnd.ni_startdir);
3597 	if (error == -1)
3598 		return (0);
3599 	return (error);
3600 }
3601 
3602 /*
3603  * Make a directory file.
3604  */
3605 #ifndef _SYS_SYSPROTO_H_
3606 struct mkdir_args {
3607 	char	*path;
3608 	int	mode;
3609 };
3610 #endif
3611 int
3612 sys_mkdir(struct thread *td, struct mkdir_args *uap)
3613 {
3614 
3615 	return (kern_mkdirat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
3616 	    uap->mode));
3617 }
3618 
3619 #ifndef _SYS_SYSPROTO_H_
3620 struct mkdirat_args {
3621 	int	fd;
3622 	char	*path;
3623 	mode_t	mode;
3624 };
3625 #endif
3626 int
3627 sys_mkdirat(struct thread *td, struct mkdirat_args *uap)
3628 {
3629 
3630 	return (kern_mkdirat(td, uap->fd, uap->path, UIO_USERSPACE, uap->mode));
3631 }
3632 
3633 int
3634 kern_mkdirat(struct thread *td, int fd, const char *path, enum uio_seg segflg,
3635     int mode)
3636 {
3637 	struct mount *mp;
3638 	struct vnode *vp;
3639 	struct vattr vattr;
3640 	struct nameidata nd;
3641 	int error;
3642 
3643 	AUDIT_ARG_MODE(mode);
3644 restart:
3645 	bwillwrite();
3646 	NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | SAVENAME | AUDITVNODE1 |
3647 	    NOCACHE, segflg, path, fd, &cap_mkdirat_rights,
3648 	    td);
3649 	nd.ni_cnd.cn_flags |= WILLBEDIR;
3650 	if ((error = namei(&nd)) != 0)
3651 		return (error);
3652 	vp = nd.ni_vp;
3653 	if (vp != NULL) {
3654 		NDFREE(&nd, NDF_ONLY_PNBUF);
3655 		/*
3656 		 * XXX namei called with LOCKPARENT but not LOCKLEAF has
3657 		 * the strange behaviour of leaving the vnode unlocked
3658 		 * if the target is the same vnode as the parent.
3659 		 */
3660 		if (vp == nd.ni_dvp)
3661 			vrele(nd.ni_dvp);
3662 		else
3663 			vput(nd.ni_dvp);
3664 		vrele(vp);
3665 		return (EEXIST);
3666 	}
3667 	if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
3668 		NDFREE(&nd, NDF_ONLY_PNBUF);
3669 		vput(nd.ni_dvp);
3670 		if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
3671 			return (error);
3672 		goto restart;
3673 	}
3674 	VATTR_NULL(&vattr);
3675 	vattr.va_type = VDIR;
3676 	vattr.va_mode = (mode & ACCESSPERMS) &~ td->td_proc->p_fd->fd_cmask;
3677 #ifdef MAC
3678 	error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
3679 	    &vattr);
3680 	if (error != 0)
3681 		goto out;
3682 #endif
3683 	error = VOP_MKDIR(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
3684 #ifdef MAC
3685 out:
3686 #endif
3687 	NDFREE(&nd, NDF_ONLY_PNBUF);
3688 	vput(nd.ni_dvp);
3689 	if (error == 0)
3690 		vput(nd.ni_vp);
3691 	vn_finished_write(mp);
3692 	return (error);
3693 }
3694 
3695 /*
3696  * Remove a directory file.
3697  */
3698 #ifndef _SYS_SYSPROTO_H_
3699 struct rmdir_args {
3700 	char	*path;
3701 };
3702 #endif
3703 int
3704 sys_rmdir(struct thread *td, struct rmdir_args *uap)
3705 {
3706 
3707 	return (kern_rmdirat(td, AT_FDCWD, uap->path, UIO_USERSPACE, 0));
3708 }
3709 
3710 int
3711 kern_rmdirat(struct thread *td, int fd, const char *path, enum uio_seg pathseg,
3712     int flag)
3713 {
3714 	struct mount *mp;
3715 	struct vnode *vp;
3716 	struct nameidata nd;
3717 	int error;
3718 
3719 restart:
3720 	bwillwrite();
3721 	NDINIT_ATRIGHTS(&nd, DELETE, LOCKPARENT | LOCKLEAF | AUDITVNODE1 |
3722 	    ((flag & AT_BENEATH) != 0 ? BENEATH : 0),
3723 	    pathseg, path, fd, &cap_unlinkat_rights, td);
3724 	if ((error = namei(&nd)) != 0)
3725 		return (error);
3726 	vp = nd.ni_vp;
3727 	if (vp->v_type != VDIR) {
3728 		error = ENOTDIR;
3729 		goto out;
3730 	}
3731 	/*
3732 	 * No rmdir "." please.
3733 	 */
3734 	if (nd.ni_dvp == vp) {
3735 		error = EINVAL;
3736 		goto out;
3737 	}
3738 	/*
3739 	 * The root of a mounted filesystem cannot be deleted.
3740 	 */
3741 	if (vp->v_vflag & VV_ROOT) {
3742 		error = EBUSY;
3743 		goto out;
3744 	}
3745 #ifdef MAC
3746 	error = mac_vnode_check_unlink(td->td_ucred, nd.ni_dvp, vp,
3747 	    &nd.ni_cnd);
3748 	if (error != 0)
3749 		goto out;
3750 #endif
3751 	if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
3752 		NDFREE(&nd, NDF_ONLY_PNBUF);
3753 		vput(vp);
3754 		if (nd.ni_dvp == vp)
3755 			vrele(nd.ni_dvp);
3756 		else
3757 			vput(nd.ni_dvp);
3758 		if ((error = vn_start_write(NULL, &mp, V_XSLEEP | PCATCH)) != 0)
3759 			return (error);
3760 		goto restart;
3761 	}
3762 	vfs_notify_upper(vp, VFS_NOTIFY_UPPER_UNLINK);
3763 	error = VOP_RMDIR(nd.ni_dvp, nd.ni_vp, &nd.ni_cnd);
3764 	vn_finished_write(mp);
3765 out:
3766 	NDFREE(&nd, NDF_ONLY_PNBUF);
3767 	vput(vp);
3768 	if (nd.ni_dvp == vp)
3769 		vrele(nd.ni_dvp);
3770 	else
3771 		vput(nd.ni_dvp);
3772 	return (error);
3773 }
3774 
3775 #if defined(COMPAT_43) || defined(COMPAT_FREEBSD11)
3776 int
3777 freebsd11_kern_getdirentries(struct thread *td, int fd, char *ubuf, u_int count,
3778     long *basep, void (*func)(struct freebsd11_dirent *))
3779 {
3780 	struct freebsd11_dirent dstdp;
3781 	struct dirent *dp, *edp;
3782 	char *dirbuf;
3783 	off_t base;
3784 	ssize_t resid, ucount;
3785 	int error;
3786 
3787 	/* XXX arbitrary sanity limit on `count'. */
3788 	count = min(count, 64 * 1024);
3789 
3790 	dirbuf = malloc(count, M_TEMP, M_WAITOK);
3791 
3792 	error = kern_getdirentries(td, fd, dirbuf, count, &base, &resid,
3793 	    UIO_SYSSPACE);
3794 	if (error != 0)
3795 		goto done;
3796 	if (basep != NULL)
3797 		*basep = base;
3798 
3799 	ucount = 0;
3800 	for (dp = (struct dirent *)dirbuf,
3801 	    edp = (struct dirent *)&dirbuf[count - resid];
3802 	    ucount < count && dp < edp; ) {
3803 		if (dp->d_reclen == 0)
3804 			break;
3805 		MPASS(dp->d_reclen >= _GENERIC_DIRLEN(0));
3806 		if (dp->d_namlen >= sizeof(dstdp.d_name))
3807 			continue;
3808 		dstdp.d_type = dp->d_type;
3809 		dstdp.d_namlen = dp->d_namlen;
3810 		dstdp.d_fileno = dp->d_fileno;		/* truncate */
3811 		if (dstdp.d_fileno != dp->d_fileno) {
3812 			switch (ino64_trunc_error) {
3813 			default:
3814 			case 0:
3815 				break;
3816 			case 1:
3817 				error = EOVERFLOW;
3818 				goto done;
3819 			case 2:
3820 				dstdp.d_fileno = UINT32_MAX;
3821 				break;
3822 			}
3823 		}
3824 		dstdp.d_reclen = sizeof(dstdp) - sizeof(dstdp.d_name) +
3825 		    ((dp->d_namlen + 1 + 3) &~ 3);
3826 		bcopy(dp->d_name, dstdp.d_name, dstdp.d_namlen);
3827 		bzero(dstdp.d_name + dstdp.d_namlen,
3828 		    dstdp.d_reclen - offsetof(struct freebsd11_dirent, d_name) -
3829 		    dstdp.d_namlen);
3830 		MPASS(dstdp.d_reclen <= dp->d_reclen);
3831 		MPASS(ucount + dstdp.d_reclen <= count);
3832 		if (func != NULL)
3833 			func(&dstdp);
3834 		error = copyout(&dstdp, ubuf + ucount, dstdp.d_reclen);
3835 		if (error != 0)
3836 			break;
3837 		dp = (struct dirent *)((char *)dp + dp->d_reclen);
3838 		ucount += dstdp.d_reclen;
3839 	}
3840 
3841 done:
3842 	free(dirbuf, M_TEMP);
3843 	if (error == 0)
3844 		td->td_retval[0] = ucount;
3845 	return (error);
3846 }
3847 #endif /* COMPAT */
3848 
3849 #ifdef COMPAT_43
3850 static void
3851 ogetdirentries_cvt(struct freebsd11_dirent *dp)
3852 {
3853 #if (BYTE_ORDER == LITTLE_ENDIAN)
3854 	/*
3855 	 * The expected low byte of dp->d_namlen is our dp->d_type.
3856 	 * The high MBZ byte of dp->d_namlen is our dp->d_namlen.
3857 	 */
3858 	dp->d_type = dp->d_namlen;
3859 	dp->d_namlen = 0;
3860 #else
3861 	/*
3862 	 * The dp->d_type is the high byte of the expected dp->d_namlen,
3863 	 * so must be zero'ed.
3864 	 */
3865 	dp->d_type = 0;
3866 #endif
3867 }
3868 
3869 /*
3870  * Read a block of directory entries in a filesystem independent format.
3871  */
3872 #ifndef _SYS_SYSPROTO_H_
3873 struct ogetdirentries_args {
3874 	int	fd;
3875 	char	*buf;
3876 	u_int	count;
3877 	long	*basep;
3878 };
3879 #endif
3880 int
3881 ogetdirentries(struct thread *td, struct ogetdirentries_args *uap)
3882 {
3883 	long loff;
3884 	int error;
3885 
3886 	error = kern_ogetdirentries(td, uap, &loff);
3887 	if (error == 0)
3888 		error = copyout(&loff, uap->basep, sizeof(long));
3889 	return (error);
3890 }
3891 
3892 int
3893 kern_ogetdirentries(struct thread *td, struct ogetdirentries_args *uap,
3894     long *ploff)
3895 {
3896 	long base;
3897 	int error;
3898 
3899 	/* XXX arbitrary sanity limit on `count'. */
3900 	if (uap->count > 64 * 1024)
3901 		return (EINVAL);
3902 
3903 	error = freebsd11_kern_getdirentries(td, uap->fd, uap->buf, uap->count,
3904 	    &base, ogetdirentries_cvt);
3905 
3906 	if (error == 0 && uap->basep != NULL)
3907 		error = copyout(&base, uap->basep, sizeof(long));
3908 
3909 	return (error);
3910 }
3911 #endif /* COMPAT_43 */
3912 
3913 #if defined(COMPAT_FREEBSD11)
3914 #ifndef _SYS_SYSPROTO_H_
3915 struct freebsd11_getdirentries_args {
3916 	int	fd;
3917 	char	*buf;
3918 	u_int	count;
3919 	long	*basep;
3920 };
3921 #endif
3922 int
3923 freebsd11_getdirentries(struct thread *td,
3924     struct freebsd11_getdirentries_args *uap)
3925 {
3926 	long base;
3927 	int error;
3928 
3929 	error = freebsd11_kern_getdirentries(td, uap->fd, uap->buf, uap->count,
3930 	    &base, NULL);
3931 
3932 	if (error == 0 && uap->basep != NULL)
3933 		error = copyout(&base, uap->basep, sizeof(long));
3934 	return (error);
3935 }
3936 
3937 int
3938 freebsd11_getdents(struct thread *td, struct freebsd11_getdents_args *uap)
3939 {
3940 	struct freebsd11_getdirentries_args ap;
3941 
3942 	ap.fd = uap->fd;
3943 	ap.buf = uap->buf;
3944 	ap.count = uap->count;
3945 	ap.basep = NULL;
3946 	return (freebsd11_getdirentries(td, &ap));
3947 }
3948 #endif /* COMPAT_FREEBSD11 */
3949 
3950 /*
3951  * Read a block of directory entries in a filesystem independent format.
3952  */
3953 int
3954 sys_getdirentries(struct thread *td, struct getdirentries_args *uap)
3955 {
3956 	off_t base;
3957 	int error;
3958 
3959 	error = kern_getdirentries(td, uap->fd, uap->buf, uap->count, &base,
3960 	    NULL, UIO_USERSPACE);
3961 	if (error != 0)
3962 		return (error);
3963 	if (uap->basep != NULL)
3964 		error = copyout(&base, uap->basep, sizeof(off_t));
3965 	return (error);
3966 }
3967 
3968 int
3969 kern_getdirentries(struct thread *td, int fd, char *buf, size_t count,
3970     off_t *basep, ssize_t *residp, enum uio_seg bufseg)
3971 {
3972 	struct vnode *vp;
3973 	struct file *fp;
3974 	struct uio auio;
3975 	struct iovec aiov;
3976 	off_t loff;
3977 	int error, eofflag;
3978 	off_t foffset;
3979 
3980 	AUDIT_ARG_FD(fd);
3981 	if (count > IOSIZE_MAX)
3982 		return (EINVAL);
3983 	auio.uio_resid = count;
3984 	error = getvnode(td, fd, &cap_read_rights, &fp);
3985 	if (error != 0)
3986 		return (error);
3987 	if ((fp->f_flag & FREAD) == 0) {
3988 		fdrop(fp, td);
3989 		return (EBADF);
3990 	}
3991 	vp = fp->f_vnode;
3992 	foffset = foffset_lock(fp, 0);
3993 unionread:
3994 	if (vp->v_type != VDIR) {
3995 		error = EINVAL;
3996 		goto fail;
3997 	}
3998 	aiov.iov_base = buf;
3999 	aiov.iov_len = count;
4000 	auio.uio_iov = &aiov;
4001 	auio.uio_iovcnt = 1;
4002 	auio.uio_rw = UIO_READ;
4003 	auio.uio_segflg = bufseg;
4004 	auio.uio_td = td;
4005 	vn_lock(vp, LK_SHARED | LK_RETRY);
4006 	AUDIT_ARG_VNODE1(vp);
4007 	loff = auio.uio_offset = foffset;
4008 #ifdef MAC
4009 	error = mac_vnode_check_readdir(td->td_ucred, vp);
4010 	if (error == 0)
4011 #endif
4012 		error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, NULL,
4013 		    NULL);
4014 	foffset = auio.uio_offset;
4015 	if (error != 0) {
4016 		VOP_UNLOCK(vp, 0);
4017 		goto fail;
4018 	}
4019 	if (count == auio.uio_resid &&
4020 	    (vp->v_vflag & VV_ROOT) &&
4021 	    (vp->v_mount->mnt_flag & MNT_UNION)) {
4022 		struct vnode *tvp = vp;
4023 
4024 		vp = vp->v_mount->mnt_vnodecovered;
4025 		VREF(vp);
4026 		fp->f_vnode = vp;
4027 		fp->f_data = vp;
4028 		foffset = 0;
4029 		vput(tvp);
4030 		goto unionread;
4031 	}
4032 	VOP_UNLOCK(vp, 0);
4033 	*basep = loff;
4034 	if (residp != NULL)
4035 		*residp = auio.uio_resid;
4036 	td->td_retval[0] = count - auio.uio_resid;
4037 fail:
4038 	foffset_unlock(fp, foffset, 0);
4039 	fdrop(fp, td);
4040 	return (error);
4041 }
4042 
4043 /*
4044  * Set the mode mask for creation of filesystem nodes.
4045  */
4046 #ifndef _SYS_SYSPROTO_H_
4047 struct umask_args {
4048 	int	newmask;
4049 };
4050 #endif
4051 int
4052 sys_umask(struct thread *td, struct umask_args *uap)
4053 {
4054 	struct filedesc *fdp;
4055 
4056 	fdp = td->td_proc->p_fd;
4057 	FILEDESC_XLOCK(fdp);
4058 	td->td_retval[0] = fdp->fd_cmask;
4059 	fdp->fd_cmask = uap->newmask & ALLPERMS;
4060 	FILEDESC_XUNLOCK(fdp);
4061 	return (0);
4062 }
4063 
4064 /*
4065  * Void all references to file by ripping underlying filesystem away from
4066  * vnode.
4067  */
4068 #ifndef _SYS_SYSPROTO_H_
4069 struct revoke_args {
4070 	char	*path;
4071 };
4072 #endif
4073 int
4074 sys_revoke(struct thread *td, struct revoke_args *uap)
4075 {
4076 	struct vnode *vp;
4077 	struct vattr vattr;
4078 	struct nameidata nd;
4079 	int error;
4080 
4081 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, UIO_USERSPACE,
4082 	    uap->path, td);
4083 	if ((error = namei(&nd)) != 0)
4084 		return (error);
4085 	vp = nd.ni_vp;
4086 	NDFREE(&nd, NDF_ONLY_PNBUF);
4087 	if (vp->v_type != VCHR || vp->v_rdev == NULL) {
4088 		error = EINVAL;
4089 		goto out;
4090 	}
4091 #ifdef MAC
4092 	error = mac_vnode_check_revoke(td->td_ucred, vp);
4093 	if (error != 0)
4094 		goto out;
4095 #endif
4096 	error = VOP_GETATTR(vp, &vattr, td->td_ucred);
4097 	if (error != 0)
4098 		goto out;
4099 	if (td->td_ucred->cr_uid != vattr.va_uid) {
4100 		error = priv_check(td, PRIV_VFS_ADMIN);
4101 		if (error != 0)
4102 			goto out;
4103 	}
4104 	if (vcount(vp) > 1)
4105 		VOP_REVOKE(vp, REVOKEALL);
4106 out:
4107 	vput(vp);
4108 	return (error);
4109 }
4110 
4111 /*
4112  * Convert a user file descriptor to a kernel file entry and check that, if it
4113  * is a capability, the correct rights are present. A reference on the file
4114  * entry is held upon returning.
4115  */
4116 int
4117 getvnode(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp)
4118 {
4119 	struct file *fp;
4120 	int error;
4121 
4122 	error = fget_unlocked(td->td_proc->p_fd, fd, rightsp, &fp, NULL);
4123 	if (error != 0)
4124 		return (error);
4125 
4126 	/*
4127 	 * The file could be not of the vnode type, or it may be not
4128 	 * yet fully initialized, in which case the f_vnode pointer
4129 	 * may be set, but f_ops is still badfileops.  E.g.,
4130 	 * devfs_open() transiently create such situation to
4131 	 * facilitate csw d_fdopen().
4132 	 *
4133 	 * Dupfdopen() handling in kern_openat() installs the
4134 	 * half-baked file into the process descriptor table, allowing
4135 	 * other thread to dereference it. Guard against the race by
4136 	 * checking f_ops.
4137 	 */
4138 	if (fp->f_vnode == NULL || fp->f_ops == &badfileops) {
4139 		fdrop(fp, td);
4140 		return (EINVAL);
4141 	}
4142 	*fpp = fp;
4143 	return (0);
4144 }
4145 
4146 
4147 /*
4148  * Get an (NFS) file handle.
4149  */
4150 #ifndef _SYS_SYSPROTO_H_
4151 struct lgetfh_args {
4152 	char *fname;
4153 	fhandle_t *fhp;
4154 };
4155 #endif
4156 int
4157 sys_lgetfh(struct thread *td, struct lgetfh_args *uap)
4158 {
4159 
4160 	return (kern_getfhat(td, AT_SYMLINK_NOFOLLOW, AT_FDCWD, uap->fname,
4161 	    UIO_USERSPACE, uap->fhp));
4162 }
4163 
4164 #ifndef _SYS_SYSPROTO_H_
4165 struct getfh_args {
4166 	char *fname;
4167 	fhandle_t *fhp;
4168 };
4169 #endif
4170 int
4171 sys_getfh(struct thread *td, struct getfh_args *uap)
4172 {
4173 
4174 	return (kern_getfhat(td, 0, AT_FDCWD, uap->fname, UIO_USERSPACE,
4175 	    uap->fhp));
4176 }
4177 
4178 /*
4179  * syscall for the rpc.lockd to use to translate an open descriptor into
4180  * a NFS file handle.
4181  *
4182  * warning: do not remove the priv_check() call or this becomes one giant
4183  * security hole.
4184  */
4185 #ifndef _SYS_SYSPROTO_H_
4186 struct getfhat_args {
4187 	int fd;
4188 	char *path;
4189 	fhandle_t *fhp;
4190 	int flags;
4191 };
4192 #endif
4193 int
4194 sys_getfhat(struct thread *td, struct getfhat_args *uap)
4195 {
4196 
4197 	if ((uap->flags & ~(AT_SYMLINK_NOFOLLOW | AT_BENEATH)) != 0)
4198 		return (EINVAL);
4199 	return (kern_getfhat(td, uap->flags, uap->fd, uap->path, UIO_USERSPACE,
4200 	    uap->fhp));
4201 }
4202 
4203 static int
4204 kern_getfhat(struct thread *td, int flags, int fd, const char *path,
4205     enum uio_seg pathseg, fhandle_t *fhp)
4206 {
4207 	struct nameidata nd;
4208 	fhandle_t fh;
4209 	struct vnode *vp;
4210 	int error;
4211 
4212 	error = priv_check(td, PRIV_VFS_GETFH);
4213 	if (error != 0)
4214 		return (error);
4215 	NDINIT_AT(&nd, LOOKUP, ((flags & AT_SYMLINK_NOFOLLOW) != 0 ? NOFOLLOW :
4216 	    FOLLOW) | ((flags & AT_BENEATH) != 0 ? BENEATH : 0) | LOCKLEAF |
4217 	    AUDITVNODE1, pathseg, path, fd, td);
4218 	error = namei(&nd);
4219 	if (error != 0)
4220 		return (error);
4221 	NDFREE(&nd, NDF_ONLY_PNBUF);
4222 	vp = nd.ni_vp;
4223 	bzero(&fh, sizeof(fh));
4224 	fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
4225 	error = VOP_VPTOFH(vp, &fh.fh_fid);
4226 	vput(vp);
4227 	if (error == 0)
4228 		error = copyout(&fh, fhp, sizeof (fh));
4229 	return (error);
4230 }
4231 
4232 #ifndef _SYS_SYSPROTO_H_
4233 struct fhlink_args {
4234 	fhandle_t *fhp;
4235 	const char *to;
4236 };
4237 #endif
4238 int
4239 sys_fhlink(struct thread *td, struct fhlink_args *uap)
4240 {
4241 
4242 	return (kern_fhlinkat(td, AT_FDCWD, uap->to, UIO_USERSPACE, uap->fhp));
4243 }
4244 
4245 #ifndef _SYS_SYSPROTO_H_
4246 struct fhlinkat_args {
4247 	fhandle_t *fhp;
4248 	int tofd;
4249 	const char *to;
4250 };
4251 #endif
4252 int
4253 sys_fhlinkat(struct thread *td, struct fhlinkat_args *uap)
4254 {
4255 
4256 	return (kern_fhlinkat(td, uap->tofd, uap->to, UIO_USERSPACE, uap->fhp));
4257 }
4258 
4259 static int
4260 kern_fhlinkat(struct thread *td, int fd, const char *path,
4261     enum uio_seg pathseg, fhandle_t *fhp)
4262 {
4263 	fhandle_t fh;
4264 	struct mount *mp;
4265 	struct vnode *vp;
4266 	int error;
4267 
4268 	error = priv_check(td, PRIV_VFS_GETFH);
4269 	if (error != 0)
4270 		return (error);
4271 	error = copyin(fhp, &fh, sizeof(fh));
4272 	if (error != 0)
4273 		return (error);
4274 	do {
4275 		bwillwrite();
4276 		if ((mp = vfs_busyfs(&fh.fh_fsid)) == NULL)
4277 			return (ESTALE);
4278 		error = VFS_FHTOVP(mp, &fh.fh_fid, LK_SHARED, &vp);
4279 		vfs_unbusy(mp);
4280 		if (error != 0)
4281 			return (error);
4282 		VOP_UNLOCK(vp, 0);
4283 	} while ((error = kern_linkat_vp(td, vp, fd, path, pathseg)) == EAGAIN);
4284 	return (error);
4285 }
4286 
4287 #ifndef _SYS_SYSPROTO_H_
4288 struct fhreadlink_args {
4289 	fhandle_t *fhp;
4290 	char *buf;
4291 	size_t bufsize;
4292 };
4293 #endif
4294 int
4295 sys_fhreadlink(struct thread *td, struct fhreadlink_args *uap)
4296 {
4297 	fhandle_t fh;
4298 	struct mount *mp;
4299 	struct vnode *vp;
4300 	int error;
4301 
4302 	error = priv_check(td, PRIV_VFS_GETFH);
4303 	if (error != 0)
4304 		return (error);
4305 	if (uap->bufsize > IOSIZE_MAX)
4306 		return (EINVAL);
4307 	error = copyin(uap->fhp, &fh, sizeof(fh));
4308 	if (error != 0)
4309 		return (error);
4310 	if ((mp = vfs_busyfs(&fh.fh_fsid)) == NULL)
4311 		return (ESTALE);
4312 	error = VFS_FHTOVP(mp, &fh.fh_fid, LK_SHARED, &vp);
4313 	vfs_unbusy(mp);
4314 	if (error != 0)
4315 		return (error);
4316 	error = kern_readlink_vp(vp, uap->buf, UIO_USERSPACE, uap->bufsize, td);
4317 	vput(vp);
4318 	return (error);
4319 }
4320 
4321 /*
4322  * syscall for the rpc.lockd to use to translate a NFS file handle into an
4323  * open descriptor.
4324  *
4325  * warning: do not remove the priv_check() call or this becomes one giant
4326  * security hole.
4327  */
4328 #ifndef _SYS_SYSPROTO_H_
4329 struct fhopen_args {
4330 	const struct fhandle *u_fhp;
4331 	int flags;
4332 };
4333 #endif
4334 int
4335 sys_fhopen(struct thread *td, struct fhopen_args *uap)
4336 {
4337 	struct mount *mp;
4338 	struct vnode *vp;
4339 	struct fhandle fhp;
4340 	struct file *fp;
4341 	int fmode, error;
4342 	int indx;
4343 
4344 	error = priv_check(td, PRIV_VFS_FHOPEN);
4345 	if (error != 0)
4346 		return (error);
4347 	indx = -1;
4348 	fmode = FFLAGS(uap->flags);
4349 	/* why not allow a non-read/write open for our lockd? */
4350 	if (((fmode & (FREAD | FWRITE)) == 0) || (fmode & O_CREAT))
4351 		return (EINVAL);
4352 	error = copyin(uap->u_fhp, &fhp, sizeof(fhp));
4353 	if (error != 0)
4354 		return(error);
4355 	/* find the mount point */
4356 	mp = vfs_busyfs(&fhp.fh_fsid);
4357 	if (mp == NULL)
4358 		return (ESTALE);
4359 	/* now give me my vnode, it gets returned to me locked */
4360 	error = VFS_FHTOVP(mp, &fhp.fh_fid, LK_EXCLUSIVE, &vp);
4361 	vfs_unbusy(mp);
4362 	if (error != 0)
4363 		return (error);
4364 
4365 	error = falloc_noinstall(td, &fp);
4366 	if (error != 0) {
4367 		vput(vp);
4368 		return (error);
4369 	}
4370 	/*
4371 	 * An extra reference on `fp' has been held for us by
4372 	 * falloc_noinstall().
4373 	 */
4374 
4375 #ifdef INVARIANTS
4376 	td->td_dupfd = -1;
4377 #endif
4378 	error = vn_open_vnode(vp, fmode, td->td_ucred, td, fp);
4379 	if (error != 0) {
4380 		KASSERT(fp->f_ops == &badfileops,
4381 		    ("VOP_OPEN in fhopen() set f_ops"));
4382 		KASSERT(td->td_dupfd < 0,
4383 		    ("fhopen() encountered fdopen()"));
4384 
4385 		vput(vp);
4386 		goto bad;
4387 	}
4388 #ifdef INVARIANTS
4389 	td->td_dupfd = 0;
4390 #endif
4391 	fp->f_vnode = vp;
4392 	fp->f_seqcount = 1;
4393 	finit(fp, (fmode & FMASK) | (fp->f_flag & FHASLOCK), DTYPE_VNODE, vp,
4394 	    &vnops);
4395 	VOP_UNLOCK(vp, 0);
4396 	if ((fmode & O_TRUNC) != 0) {
4397 		error = fo_truncate(fp, 0, td->td_ucred, td);
4398 		if (error != 0)
4399 			goto bad;
4400 	}
4401 
4402 	error = finstall(td, fp, &indx, fmode, NULL);
4403 bad:
4404 	fdrop(fp, td);
4405 	td->td_retval[0] = indx;
4406 	return (error);
4407 }
4408 
4409 /*
4410  * Stat an (NFS) file handle.
4411  */
4412 #ifndef _SYS_SYSPROTO_H_
4413 struct fhstat_args {
4414 	struct fhandle *u_fhp;
4415 	struct stat *sb;
4416 };
4417 #endif
4418 int
4419 sys_fhstat(struct thread *td, struct fhstat_args *uap)
4420 {
4421 	struct stat sb;
4422 	struct fhandle fh;
4423 	int error;
4424 
4425 	error = copyin(uap->u_fhp, &fh, sizeof(fh));
4426 	if (error != 0)
4427 		return (error);
4428 	error = kern_fhstat(td, fh, &sb);
4429 	if (error == 0)
4430 		error = copyout(&sb, uap->sb, sizeof(sb));
4431 	return (error);
4432 }
4433 
4434 int
4435 kern_fhstat(struct thread *td, struct fhandle fh, struct stat *sb)
4436 {
4437 	struct mount *mp;
4438 	struct vnode *vp;
4439 	int error;
4440 
4441 	error = priv_check(td, PRIV_VFS_FHSTAT);
4442 	if (error != 0)
4443 		return (error);
4444 	if ((mp = vfs_busyfs(&fh.fh_fsid)) == NULL)
4445 		return (ESTALE);
4446 	error = VFS_FHTOVP(mp, &fh.fh_fid, LK_EXCLUSIVE, &vp);
4447 	vfs_unbusy(mp);
4448 	if (error != 0)
4449 		return (error);
4450 	error = vn_stat(vp, sb, td->td_ucred, NOCRED, td);
4451 	vput(vp);
4452 	return (error);
4453 }
4454 
4455 /*
4456  * Implement fstatfs() for (NFS) file handles.
4457  */
4458 #ifndef _SYS_SYSPROTO_H_
4459 struct fhstatfs_args {
4460 	struct fhandle *u_fhp;
4461 	struct statfs *buf;
4462 };
4463 #endif
4464 int
4465 sys_fhstatfs(struct thread *td, struct fhstatfs_args *uap)
4466 {
4467 	struct statfs *sfp;
4468 	fhandle_t fh;
4469 	int error;
4470 
4471 	error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t));
4472 	if (error != 0)
4473 		return (error);
4474 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
4475 	error = kern_fhstatfs(td, fh, sfp);
4476 	if (error == 0)
4477 		error = copyout(sfp, uap->buf, sizeof(*sfp));
4478 	free(sfp, M_STATFS);
4479 	return (error);
4480 }
4481 
4482 int
4483 kern_fhstatfs(struct thread *td, fhandle_t fh, struct statfs *buf)
4484 {
4485 	struct statfs *sp;
4486 	struct mount *mp;
4487 	struct vnode *vp;
4488 	int error;
4489 
4490 	error = priv_check(td, PRIV_VFS_FHSTATFS);
4491 	if (error != 0)
4492 		return (error);
4493 	if ((mp = vfs_busyfs(&fh.fh_fsid)) == NULL)
4494 		return (ESTALE);
4495 	error = VFS_FHTOVP(mp, &fh.fh_fid, LK_EXCLUSIVE, &vp);
4496 	if (error != 0) {
4497 		vfs_unbusy(mp);
4498 		return (error);
4499 	}
4500 	vput(vp);
4501 	error = prison_canseemount(td->td_ucred, mp);
4502 	if (error != 0)
4503 		goto out;
4504 #ifdef MAC
4505 	error = mac_mount_check_stat(td->td_ucred, mp);
4506 	if (error != 0)
4507 		goto out;
4508 #endif
4509 	/*
4510 	 * Set these in case the underlying filesystem fails to do so.
4511 	 */
4512 	sp = &mp->mnt_stat;
4513 	sp->f_version = STATFS_VERSION;
4514 	sp->f_namemax = NAME_MAX;
4515 	sp->f_flags = mp->mnt_flag & MNT_VISFLAGMASK;
4516 	error = VFS_STATFS(mp, sp);
4517 	if (error == 0)
4518 		*buf = *sp;
4519 out:
4520 	vfs_unbusy(mp);
4521 	return (error);
4522 }
4523 
4524 int
4525 kern_posix_fallocate(struct thread *td, int fd, off_t offset, off_t len)
4526 {
4527 	struct file *fp;
4528 	struct mount *mp;
4529 	struct vnode *vp;
4530 	off_t olen, ooffset;
4531 	int error;
4532 #ifdef AUDIT
4533 	int audited_vnode1 = 0;
4534 #endif
4535 
4536 	AUDIT_ARG_FD(fd);
4537 	if (offset < 0 || len <= 0)
4538 		return (EINVAL);
4539 	/* Check for wrap. */
4540 	if (offset > OFF_MAX - len)
4541 		return (EFBIG);
4542 	AUDIT_ARG_FD(fd);
4543 	error = fget(td, fd, &cap_pwrite_rights, &fp);
4544 	if (error != 0)
4545 		return (error);
4546 	AUDIT_ARG_FILE(td->td_proc, fp);
4547 	if ((fp->f_ops->fo_flags & DFLAG_SEEKABLE) == 0) {
4548 		error = ESPIPE;
4549 		goto out;
4550 	}
4551 	if ((fp->f_flag & FWRITE) == 0) {
4552 		error = EBADF;
4553 		goto out;
4554 	}
4555 	if (fp->f_type != DTYPE_VNODE) {
4556 		error = ENODEV;
4557 		goto out;
4558 	}
4559 	vp = fp->f_vnode;
4560 	if (vp->v_type != VREG) {
4561 		error = ENODEV;
4562 		goto out;
4563 	}
4564 
4565 	/* Allocating blocks may take a long time, so iterate. */
4566 	for (;;) {
4567 		olen = len;
4568 		ooffset = offset;
4569 
4570 		bwillwrite();
4571 		mp = NULL;
4572 		error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
4573 		if (error != 0)
4574 			break;
4575 		error = vn_lock(vp, LK_EXCLUSIVE);
4576 		if (error != 0) {
4577 			vn_finished_write(mp);
4578 			break;
4579 		}
4580 #ifdef AUDIT
4581 		if (!audited_vnode1) {
4582 			AUDIT_ARG_VNODE1(vp);
4583 			audited_vnode1 = 1;
4584 		}
4585 #endif
4586 #ifdef MAC
4587 		error = mac_vnode_check_write(td->td_ucred, fp->f_cred, vp);
4588 		if (error == 0)
4589 #endif
4590 			error = VOP_ALLOCATE(vp, &offset, &len);
4591 		VOP_UNLOCK(vp, 0);
4592 		vn_finished_write(mp);
4593 
4594 		if (olen + ooffset != offset + len) {
4595 			panic("offset + len changed from %jx/%jx to %jx/%jx",
4596 			    ooffset, olen, offset, len);
4597 		}
4598 		if (error != 0 || len == 0)
4599 			break;
4600 		KASSERT(olen > len, ("Iteration did not make progress?"));
4601 		maybe_yield();
4602 	}
4603  out:
4604 	fdrop(fp, td);
4605 	return (error);
4606 }
4607 
4608 int
4609 sys_posix_fallocate(struct thread *td, struct posix_fallocate_args *uap)
4610 {
4611 	int error;
4612 
4613 	error = kern_posix_fallocate(td, uap->fd, uap->offset, uap->len);
4614 	return (kern_posix_error(td, error));
4615 }
4616 
4617 /*
4618  * Unlike madvise(2), we do not make a best effort to remember every
4619  * possible caching hint.  Instead, we remember the last setting with
4620  * the exception that we will allow POSIX_FADV_NORMAL to adjust the
4621  * region of any current setting.
4622  */
4623 int
4624 kern_posix_fadvise(struct thread *td, int fd, off_t offset, off_t len,
4625     int advice)
4626 {
4627 	struct fadvise_info *fa, *new;
4628 	struct file *fp;
4629 	struct vnode *vp;
4630 	off_t end;
4631 	int error;
4632 
4633 	if (offset < 0 || len < 0 || offset > OFF_MAX - len)
4634 		return (EINVAL);
4635 	AUDIT_ARG_VALUE(advice);
4636 	switch (advice) {
4637 	case POSIX_FADV_SEQUENTIAL:
4638 	case POSIX_FADV_RANDOM:
4639 	case POSIX_FADV_NOREUSE:
4640 		new = malloc(sizeof(*fa), M_FADVISE, M_WAITOK);
4641 		break;
4642 	case POSIX_FADV_NORMAL:
4643 	case POSIX_FADV_WILLNEED:
4644 	case POSIX_FADV_DONTNEED:
4645 		new = NULL;
4646 		break;
4647 	default:
4648 		return (EINVAL);
4649 	}
4650 	/* XXX: CAP_POSIX_FADVISE? */
4651 	AUDIT_ARG_FD(fd);
4652 	error = fget(td, fd, &cap_no_rights, &fp);
4653 	if (error != 0)
4654 		goto out;
4655 	AUDIT_ARG_FILE(td->td_proc, fp);
4656 	if ((fp->f_ops->fo_flags & DFLAG_SEEKABLE) == 0) {
4657 		error = ESPIPE;
4658 		goto out;
4659 	}
4660 	if (fp->f_type != DTYPE_VNODE) {
4661 		error = ENODEV;
4662 		goto out;
4663 	}
4664 	vp = fp->f_vnode;
4665 	if (vp->v_type != VREG) {
4666 		error = ENODEV;
4667 		goto out;
4668 	}
4669 	if (len == 0)
4670 		end = OFF_MAX;
4671 	else
4672 		end = offset + len - 1;
4673 	switch (advice) {
4674 	case POSIX_FADV_SEQUENTIAL:
4675 	case POSIX_FADV_RANDOM:
4676 	case POSIX_FADV_NOREUSE:
4677 		/*
4678 		 * Try to merge any existing non-standard region with
4679 		 * this new region if possible, otherwise create a new
4680 		 * non-standard region for this request.
4681 		 */
4682 		mtx_pool_lock(mtxpool_sleep, fp);
4683 		fa = fp->f_advice;
4684 		if (fa != NULL && fa->fa_advice == advice &&
4685 		    ((fa->fa_start <= end && fa->fa_end >= offset) ||
4686 		    (end != OFF_MAX && fa->fa_start == end + 1) ||
4687 		    (fa->fa_end != OFF_MAX && fa->fa_end + 1 == offset))) {
4688 			if (offset < fa->fa_start)
4689 				fa->fa_start = offset;
4690 			if (end > fa->fa_end)
4691 				fa->fa_end = end;
4692 		} else {
4693 			new->fa_advice = advice;
4694 			new->fa_start = offset;
4695 			new->fa_end = end;
4696 			fp->f_advice = new;
4697 			new = fa;
4698 		}
4699 		mtx_pool_unlock(mtxpool_sleep, fp);
4700 		break;
4701 	case POSIX_FADV_NORMAL:
4702 		/*
4703 		 * If a the "normal" region overlaps with an existing
4704 		 * non-standard region, trim or remove the
4705 		 * non-standard region.
4706 		 */
4707 		mtx_pool_lock(mtxpool_sleep, fp);
4708 		fa = fp->f_advice;
4709 		if (fa != NULL) {
4710 			if (offset <= fa->fa_start && end >= fa->fa_end) {
4711 				new = fa;
4712 				fp->f_advice = NULL;
4713 			} else if (offset <= fa->fa_start &&
4714 			    end >= fa->fa_start)
4715 				fa->fa_start = end + 1;
4716 			else if (offset <= fa->fa_end && end >= fa->fa_end)
4717 				fa->fa_end = offset - 1;
4718 			else if (offset >= fa->fa_start && end <= fa->fa_end) {
4719 				/*
4720 				 * If the "normal" region is a middle
4721 				 * portion of the existing
4722 				 * non-standard region, just remove
4723 				 * the whole thing rather than picking
4724 				 * one side or the other to
4725 				 * preserve.
4726 				 */
4727 				new = fa;
4728 				fp->f_advice = NULL;
4729 			}
4730 		}
4731 		mtx_pool_unlock(mtxpool_sleep, fp);
4732 		break;
4733 	case POSIX_FADV_WILLNEED:
4734 	case POSIX_FADV_DONTNEED:
4735 		error = VOP_ADVISE(vp, offset, end, advice);
4736 		break;
4737 	}
4738 out:
4739 	if (fp != NULL)
4740 		fdrop(fp, td);
4741 	free(new, M_FADVISE);
4742 	return (error);
4743 }
4744 
4745 int
4746 sys_posix_fadvise(struct thread *td, struct posix_fadvise_args *uap)
4747 {
4748 	int error;
4749 
4750 	error = kern_posix_fadvise(td, uap->fd, uap->offset, uap->len,
4751 	    uap->advice);
4752 	return (kern_posix_error(td, error));
4753 }
4754