xref: /freebsd-14.2/sys/kern/vfs_syscalls.c (revision ddbbc129)
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 #include "opt_capsicum.h"
41 #include "opt_ktrace.h"
42 
43 #include <sys/param.h>
44 #include <sys/systm.h>
45 #ifdef COMPAT_FREEBSD11
46 #include <sys/abi_compat.h>
47 #endif
48 #include <sys/bio.h>
49 #include <sys/buf.h>
50 #include <sys/capsicum.h>
51 #include <sys/disk.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/vnode_pager.h>
89 #include <vm/uma.h>
90 
91 #include <fs/devfs/devfs.h>
92 
93 MALLOC_DEFINE(M_FADVISE, "fadvise", "posix_fadvise(2) information");
94 
95 static int kern_chflagsat(struct thread *td, int fd, const char *path,
96     enum uio_seg pathseg, u_long flags, int atflag);
97 static int setfflags(struct thread *td, struct vnode *, u_long);
98 static int getutimes(const struct timeval *, enum uio_seg, struct timespec *);
99 static int getutimens(const struct timespec *, enum uio_seg,
100     struct timespec *, int *);
101 static int setutimes(struct thread *td, struct vnode *,
102     const struct timespec *, int, int);
103 static int vn_access(struct vnode *vp, int user_flags, struct ucred *cred,
104     struct thread *td);
105 static int kern_fhlinkat(struct thread *td, int fd, const char *path,
106     enum uio_seg pathseg, fhandle_t *fhp);
107 static int kern_readlink_vp(struct vnode *vp, char *buf, enum uio_seg bufseg,
108     size_t count, struct thread *td);
109 static int kern_linkat_vp(struct thread *td, struct vnode *vp, int fd,
110     const char *path, enum uio_seg segflag);
111 
112 uint64_t
at2cnpflags(u_int at_flags,u_int mask)113 at2cnpflags(u_int at_flags, u_int mask)
114 {
115 	uint64_t res;
116 
117 	MPASS((at_flags & (AT_SYMLINK_FOLLOW | AT_SYMLINK_NOFOLLOW)) !=
118 	    (AT_SYMLINK_FOLLOW | AT_SYMLINK_NOFOLLOW));
119 
120 	res = 0;
121 	at_flags &= mask;
122 	if ((at_flags & AT_RESOLVE_BENEATH) != 0)
123 		res |= RBENEATH;
124 	if ((at_flags & AT_SYMLINK_FOLLOW) != 0)
125 		res |= FOLLOW;
126 	/* NOFOLLOW is pseudo flag */
127 	if ((mask & AT_SYMLINK_NOFOLLOW) != 0) {
128 		res |= (at_flags & AT_SYMLINK_NOFOLLOW) != 0 ? NOFOLLOW :
129 		    FOLLOW;
130 	}
131 	if ((mask & AT_EMPTY_PATH) != 0 && (at_flags & AT_EMPTY_PATH) != 0)
132 		res |= EMPTYPATH;
133 	return (res);
134 }
135 
136 int
kern_sync(struct thread * td)137 kern_sync(struct thread *td)
138 {
139 	struct mount *mp, *nmp;
140 	int save;
141 
142 	mtx_lock(&mountlist_mtx);
143 	for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
144 		if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) {
145 			nmp = TAILQ_NEXT(mp, mnt_list);
146 			continue;
147 		}
148 		if ((mp->mnt_flag & MNT_RDONLY) == 0 &&
149 		    vn_start_write(NULL, &mp, V_NOWAIT) == 0) {
150 			save = curthread_pflags_set(TDP_SYNCIO);
151 			vfs_periodic(mp, MNT_NOWAIT);
152 			VFS_SYNC(mp, MNT_NOWAIT);
153 			curthread_pflags_restore(save);
154 			vn_finished_write(mp);
155 		}
156 		mtx_lock(&mountlist_mtx);
157 		nmp = TAILQ_NEXT(mp, mnt_list);
158 		vfs_unbusy(mp);
159 	}
160 	mtx_unlock(&mountlist_mtx);
161 	return (0);
162 }
163 
164 /*
165  * Sync each mounted filesystem.
166  */
167 #ifndef _SYS_SYSPROTO_H_
168 struct sync_args {
169 	int     dummy;
170 };
171 #endif
172 /* ARGSUSED */
173 int
sys_sync(struct thread * td,struct sync_args * uap)174 sys_sync(struct thread *td, struct sync_args *uap)
175 {
176 
177 	return (kern_sync(td));
178 }
179 
180 /*
181  * Change filesystem quotas.
182  */
183 #ifndef _SYS_SYSPROTO_H_
184 struct quotactl_args {
185 	char *path;
186 	int cmd;
187 	int uid;
188 	caddr_t arg;
189 };
190 #endif
191 int
sys_quotactl(struct thread * td,struct quotactl_args * uap)192 sys_quotactl(struct thread *td, struct quotactl_args *uap)
193 {
194 	struct mount *mp;
195 	struct nameidata nd;
196 	int error;
197 	bool mp_busy;
198 
199 	AUDIT_ARG_CMD(uap->cmd);
200 	AUDIT_ARG_UID(uap->uid);
201 	if (!prison_allow(td->td_ucred, PR_ALLOW_QUOTAS))
202 		return (EPERM);
203 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, UIO_USERSPACE,
204 	    uap->path);
205 	if ((error = namei(&nd)) != 0)
206 		return (error);
207 	NDFREE_PNBUF(&nd);
208 	mp = nd.ni_vp->v_mount;
209 	vfs_ref(mp);
210 	vput(nd.ni_vp);
211 	error = vfs_busy(mp, 0);
212 	if (error != 0) {
213 		vfs_rel(mp);
214 		return (error);
215 	}
216 	mp_busy = true;
217 	error = VFS_QUOTACTL(mp, uap->cmd, uap->uid, uap->arg, &mp_busy);
218 
219 	/*
220 	 * Since quota on/off operations typically need to open quota
221 	 * files, the implementation may need to unbusy the mount point
222 	 * before calling into namei.  Otherwise, unmount might be
223 	 * started between two vfs_busy() invocations (first is ours,
224 	 * second is from mount point cross-walk code in lookup()),
225 	 * causing deadlock.
226 	 *
227 	 * Avoid unbusying mp if the implementation indicates it has
228 	 * already done so.
229 	 */
230 	if (mp_busy)
231 		vfs_unbusy(mp);
232 	vfs_rel(mp);
233 	return (error);
234 }
235 
236 /*
237  * Used by statfs conversion routines to scale the block size up if
238  * necessary so that all of the block counts are <= 'max_size'.  Note
239  * that 'max_size' should be a bitmask, i.e. 2^n - 1 for some non-zero
240  * value of 'n'.
241  */
242 void
statfs_scale_blocks(struct statfs * sf,long max_size)243 statfs_scale_blocks(struct statfs *sf, long max_size)
244 {
245 	uint64_t count;
246 	int shift;
247 
248 	KASSERT(powerof2(max_size + 1), ("%s: invalid max_size", __func__));
249 
250 	/*
251 	 * Attempt to scale the block counts to give a more accurate
252 	 * overview to userland of the ratio of free space to used
253 	 * space.  To do this, find the largest block count and compute
254 	 * a divisor that lets it fit into a signed integer <= max_size.
255 	 */
256 	if (sf->f_bavail < 0)
257 		count = -sf->f_bavail;
258 	else
259 		count = sf->f_bavail;
260 	count = MAX(sf->f_blocks, MAX(sf->f_bfree, count));
261 	if (count <= max_size)
262 		return;
263 
264 	count >>= flsl(max_size);
265 	shift = 0;
266 	while (count > 0) {
267 		shift++;
268 		count >>=1;
269 	}
270 
271 	sf->f_bsize <<= shift;
272 	sf->f_blocks >>= shift;
273 	sf->f_bfree >>= shift;
274 	sf->f_bavail >>= shift;
275 }
276 
277 static int
kern_do_statfs(struct thread * td,struct mount * mp,struct statfs * buf)278 kern_do_statfs(struct thread *td, struct mount *mp, struct statfs *buf)
279 {
280 	int error;
281 
282 	if (mp == NULL)
283 		return (EBADF);
284 	error = vfs_busy(mp, 0);
285 	vfs_rel(mp);
286 	if (error != 0)
287 		return (error);
288 #ifdef MAC
289 	error = mac_mount_check_stat(td->td_ucred, mp);
290 	if (error != 0)
291 		goto out;
292 #endif
293 	error = VFS_STATFS(mp, buf);
294 	if (error != 0)
295 		goto out;
296 	if (priv_check_cred_vfs_generation(td->td_ucred)) {
297 		buf->f_fsid.val[0] = buf->f_fsid.val[1] = 0;
298 		prison_enforce_statfs(td->td_ucred, mp, buf);
299 	}
300 out:
301 	vfs_unbusy(mp);
302 	return (error);
303 }
304 
305 /*
306  * Get filesystem statistics.
307  */
308 #ifndef _SYS_SYSPROTO_H_
309 struct statfs_args {
310 	char *path;
311 	struct statfs *buf;
312 };
313 #endif
314 int
sys_statfs(struct thread * td,struct statfs_args * uap)315 sys_statfs(struct thread *td, struct statfs_args *uap)
316 {
317 	struct statfs *sfp;
318 	int error;
319 
320 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
321 	error = kern_statfs(td, uap->path, UIO_USERSPACE, sfp);
322 	if (error == 0)
323 		error = copyout(sfp, uap->buf, sizeof(struct statfs));
324 	free(sfp, M_STATFS);
325 	return (error);
326 }
327 
328 int
kern_statfs(struct thread * td,const char * path,enum uio_seg pathseg,struct statfs * buf)329 kern_statfs(struct thread *td, const char *path, enum uio_seg pathseg,
330     struct statfs *buf)
331 {
332 	struct mount *mp;
333 	struct nameidata nd;
334 	int error;
335 
336 	NDINIT(&nd, LOOKUP, FOLLOW | AUDITVNODE1, pathseg, path);
337 	error = namei(&nd);
338 	if (error != 0)
339 		return (error);
340 	NDFREE_PNBUF(&nd);
341 	mp = vfs_ref_from_vp(nd.ni_vp);
342 	vrele(nd.ni_vp);
343 	return (kern_do_statfs(td, mp, buf));
344 }
345 
346 /*
347  * Get filesystem statistics.
348  */
349 #ifndef _SYS_SYSPROTO_H_
350 struct fstatfs_args {
351 	int fd;
352 	struct statfs *buf;
353 };
354 #endif
355 int
sys_fstatfs(struct thread * td,struct fstatfs_args * uap)356 sys_fstatfs(struct thread *td, struct fstatfs_args *uap)
357 {
358 	struct statfs *sfp;
359 	int error;
360 
361 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
362 	error = kern_fstatfs(td, uap->fd, sfp);
363 	if (error == 0)
364 		error = copyout(sfp, uap->buf, sizeof(struct statfs));
365 	free(sfp, M_STATFS);
366 	return (error);
367 }
368 
369 int
kern_fstatfs(struct thread * td,int fd,struct statfs * buf)370 kern_fstatfs(struct thread *td, int fd, struct statfs *buf)
371 {
372 	struct file *fp;
373 	struct mount *mp;
374 	struct vnode *vp;
375 	int error;
376 
377 	AUDIT_ARG_FD(fd);
378 	error = getvnode_path(td, fd, &cap_fstatfs_rights, &fp);
379 	if (error != 0)
380 		return (error);
381 	vp = fp->f_vnode;
382 #ifdef AUDIT
383 	if (AUDITING_TD(td)) {
384 		vn_lock(vp, LK_SHARED | LK_RETRY);
385 		AUDIT_ARG_VNODE1(vp);
386 		VOP_UNLOCK(vp);
387 	}
388 #endif
389 	mp = vfs_ref_from_vp(vp);
390 	fdrop(fp, td);
391 	return (kern_do_statfs(td, mp, buf));
392 }
393 
394 /*
395  * Get statistics on all filesystems.
396  */
397 #ifndef _SYS_SYSPROTO_H_
398 struct getfsstat_args {
399 	struct statfs *buf;
400 	long bufsize;
401 	int mode;
402 };
403 #endif
404 int
sys_getfsstat(struct thread * td,struct getfsstat_args * uap)405 sys_getfsstat(struct thread *td, struct getfsstat_args *uap)
406 {
407 	size_t count;
408 	int error;
409 
410 	if (uap->bufsize < 0 || uap->bufsize > SIZE_MAX)
411 		return (EINVAL);
412 	error = kern_getfsstat(td, &uap->buf, uap->bufsize, &count,
413 	    UIO_USERSPACE, uap->mode);
414 	if (error == 0)
415 		td->td_retval[0] = count;
416 	return (error);
417 }
418 
419 /*
420  * If (bufsize > 0 && bufseg == UIO_SYSSPACE)
421  *	The caller is responsible for freeing memory which will be allocated
422  *	in '*buf'.
423  */
424 int
kern_getfsstat(struct thread * td,struct statfs ** buf,size_t bufsize,size_t * countp,enum uio_seg bufseg,int mode)425 kern_getfsstat(struct thread *td, struct statfs **buf, size_t bufsize,
426     size_t *countp, enum uio_seg bufseg, int mode)
427 {
428 	struct mount *mp, *nmp;
429 	struct statfs *sfsp, *sp, *sptmp, *tofree;
430 	size_t count, maxcount;
431 	int error;
432 
433 	switch (mode) {
434 	case MNT_WAIT:
435 	case MNT_NOWAIT:
436 		break;
437 	default:
438 		if (bufseg == UIO_SYSSPACE)
439 			*buf = NULL;
440 		return (EINVAL);
441 	}
442 restart:
443 	maxcount = bufsize / sizeof(struct statfs);
444 	if (bufsize == 0) {
445 		sfsp = NULL;
446 		tofree = NULL;
447 	} else if (bufseg == UIO_USERSPACE) {
448 		sfsp = *buf;
449 		tofree = NULL;
450 	} else /* if (bufseg == UIO_SYSSPACE) */ {
451 		count = 0;
452 		mtx_lock(&mountlist_mtx);
453 		TAILQ_FOREACH(mp, &mountlist, mnt_list) {
454 			count++;
455 		}
456 		mtx_unlock(&mountlist_mtx);
457 		if (maxcount > count)
458 			maxcount = count;
459 		tofree = sfsp = *buf = malloc(maxcount * sizeof(struct statfs),
460 		    M_STATFS, M_WAITOK);
461 	}
462 
463 	count = 0;
464 
465 	/*
466 	 * If there is no target buffer they only want the count.
467 	 *
468 	 * This could be TAILQ_FOREACH but it is open-coded to match the original
469 	 * code below.
470 	 */
471 	if (sfsp == NULL) {
472 		mtx_lock(&mountlist_mtx);
473 		for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
474 			if (prison_canseemount(td->td_ucred, mp) != 0) {
475 				nmp = TAILQ_NEXT(mp, mnt_list);
476 				continue;
477 			}
478 #ifdef MAC
479 			if (mac_mount_check_stat(td->td_ucred, mp) != 0) {
480 				nmp = TAILQ_NEXT(mp, mnt_list);
481 				continue;
482 			}
483 #endif
484 			count++;
485 			nmp = TAILQ_NEXT(mp, mnt_list);
486 		}
487 		mtx_unlock(&mountlist_mtx);
488 		*countp = count;
489 		return (0);
490 	}
491 
492 	/*
493 	 * They want the entire thing.
494 	 *
495 	 * Short-circuit the corner case of no room for anything, avoids
496 	 * relocking below.
497 	 */
498 	if (maxcount < 1) {
499 		goto out;
500 	}
501 
502 	mtx_lock(&mountlist_mtx);
503 	for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
504 		if (prison_canseemount(td->td_ucred, mp) != 0) {
505 			nmp = TAILQ_NEXT(mp, mnt_list);
506 			continue;
507 		}
508 #ifdef MAC
509 		if (mac_mount_check_stat(td->td_ucred, mp) != 0) {
510 			nmp = TAILQ_NEXT(mp, mnt_list);
511 			continue;
512 		}
513 #endif
514 		if (mode == MNT_WAIT) {
515 			if (vfs_busy(mp, MBF_MNTLSTLOCK) != 0) {
516 				/*
517 				 * If vfs_busy() failed, and MBF_NOWAIT
518 				 * wasn't passed, then the mp is gone.
519 				 * Furthermore, because of MBF_MNTLSTLOCK,
520 				 * the mountlist_mtx was dropped.  We have
521 				 * no other choice than to start over.
522 				 */
523 				mtx_unlock(&mountlist_mtx);
524 				free(tofree, M_STATFS);
525 				goto restart;
526 			}
527 		} else {
528 			if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK) != 0) {
529 				nmp = TAILQ_NEXT(mp, mnt_list);
530 				continue;
531 			}
532 		}
533 		sp = &mp->mnt_stat;
534 		/*
535 		 * If MNT_NOWAIT is specified, do not refresh
536 		 * the fsstat cache.
537 		 */
538 		if (mode != MNT_NOWAIT) {
539 			error = VFS_STATFS(mp, sp);
540 			if (error != 0) {
541 				mtx_lock(&mountlist_mtx);
542 				nmp = TAILQ_NEXT(mp, mnt_list);
543 				vfs_unbusy(mp);
544 				continue;
545 			}
546 		}
547 		if (priv_check_cred_vfs_generation(td->td_ucred)) {
548 			sptmp = malloc(sizeof(struct statfs), M_STATFS,
549 			    M_WAITOK);
550 			*sptmp = *sp;
551 			sptmp->f_fsid.val[0] = sptmp->f_fsid.val[1] = 0;
552 			prison_enforce_statfs(td->td_ucred, mp, sptmp);
553 			sp = sptmp;
554 		} else
555 			sptmp = NULL;
556 		if (bufseg == UIO_SYSSPACE) {
557 			bcopy(sp, sfsp, sizeof(*sp));
558 			free(sptmp, M_STATFS);
559 		} else /* if (bufseg == UIO_USERSPACE) */ {
560 			error = copyout(sp, sfsp, sizeof(*sp));
561 			free(sptmp, M_STATFS);
562 			if (error != 0) {
563 				vfs_unbusy(mp);
564 				return (error);
565 			}
566 		}
567 		sfsp++;
568 		count++;
569 
570 		if (count == maxcount) {
571 			vfs_unbusy(mp);
572 			goto out;
573 		}
574 
575 		mtx_lock(&mountlist_mtx);
576 		nmp = TAILQ_NEXT(mp, mnt_list);
577 		vfs_unbusy(mp);
578 	}
579 	mtx_unlock(&mountlist_mtx);
580 out:
581 	*countp = count;
582 	return (0);
583 }
584 
585 #ifdef COMPAT_FREEBSD4
586 /*
587  * Get old format filesystem statistics.
588  */
589 static void freebsd4_cvtstatfs(struct statfs *, struct ostatfs *);
590 
591 #ifndef _SYS_SYSPROTO_H_
592 struct freebsd4_statfs_args {
593 	char *path;
594 	struct ostatfs *buf;
595 };
596 #endif
597 int
freebsd4_statfs(struct thread * td,struct freebsd4_statfs_args * uap)598 freebsd4_statfs(struct thread *td, struct freebsd4_statfs_args *uap)
599 {
600 	struct ostatfs osb;
601 	struct statfs *sfp;
602 	int error;
603 
604 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
605 	error = kern_statfs(td, uap->path, UIO_USERSPACE, sfp);
606 	if (error == 0) {
607 		freebsd4_cvtstatfs(sfp, &osb);
608 		error = copyout(&osb, uap->buf, sizeof(osb));
609 	}
610 	free(sfp, M_STATFS);
611 	return (error);
612 }
613 
614 /*
615  * Get filesystem statistics.
616  */
617 #ifndef _SYS_SYSPROTO_H_
618 struct freebsd4_fstatfs_args {
619 	int fd;
620 	struct ostatfs *buf;
621 };
622 #endif
623 int
freebsd4_fstatfs(struct thread * td,struct freebsd4_fstatfs_args * uap)624 freebsd4_fstatfs(struct thread *td, struct freebsd4_fstatfs_args *uap)
625 {
626 	struct ostatfs osb;
627 	struct statfs *sfp;
628 	int error;
629 
630 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
631 	error = kern_fstatfs(td, uap->fd, sfp);
632 	if (error == 0) {
633 		freebsd4_cvtstatfs(sfp, &osb);
634 		error = copyout(&osb, uap->buf, sizeof(osb));
635 	}
636 	free(sfp, M_STATFS);
637 	return (error);
638 }
639 
640 /*
641  * Get statistics on all filesystems.
642  */
643 #ifndef _SYS_SYSPROTO_H_
644 struct freebsd4_getfsstat_args {
645 	struct ostatfs *buf;
646 	long bufsize;
647 	int mode;
648 };
649 #endif
650 int
freebsd4_getfsstat(struct thread * td,struct freebsd4_getfsstat_args * uap)651 freebsd4_getfsstat(struct thread *td, struct freebsd4_getfsstat_args *uap)
652 {
653 	struct statfs *buf, *sp;
654 	struct ostatfs osb;
655 	size_t count, size;
656 	int error;
657 
658 	if (uap->bufsize < 0)
659 		return (EINVAL);
660 	count = uap->bufsize / sizeof(struct ostatfs);
661 	if (count > SIZE_MAX / sizeof(struct statfs))
662 		return (EINVAL);
663 	size = count * sizeof(struct statfs);
664 	error = kern_getfsstat(td, &buf, size, &count, UIO_SYSSPACE,
665 	    uap->mode);
666 	if (error == 0)
667 		td->td_retval[0] = count;
668 	if (size != 0) {
669 		sp = buf;
670 		while (count != 0 && error == 0) {
671 			freebsd4_cvtstatfs(sp, &osb);
672 			error = copyout(&osb, uap->buf, sizeof(osb));
673 			sp++;
674 			uap->buf++;
675 			count--;
676 		}
677 		free(buf, M_STATFS);
678 	}
679 	return (error);
680 }
681 
682 /*
683  * Implement fstatfs() for (NFS) file handles.
684  */
685 #ifndef _SYS_SYSPROTO_H_
686 struct freebsd4_fhstatfs_args {
687 	struct fhandle *u_fhp;
688 	struct ostatfs *buf;
689 };
690 #endif
691 int
freebsd4_fhstatfs(struct thread * td,struct freebsd4_fhstatfs_args * uap)692 freebsd4_fhstatfs(struct thread *td, struct freebsd4_fhstatfs_args *uap)
693 {
694 	struct ostatfs osb;
695 	struct statfs *sfp;
696 	fhandle_t fh;
697 	int error;
698 
699 	error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t));
700 	if (error != 0)
701 		return (error);
702 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
703 	error = kern_fhstatfs(td, fh, sfp);
704 	if (error == 0) {
705 		freebsd4_cvtstatfs(sfp, &osb);
706 		error = copyout(&osb, uap->buf, sizeof(osb));
707 	}
708 	free(sfp, M_STATFS);
709 	return (error);
710 }
711 
712 /*
713  * Convert a new format statfs structure to an old format statfs structure.
714  */
715 static void
freebsd4_cvtstatfs(struct statfs * nsp,struct ostatfs * osp)716 freebsd4_cvtstatfs(struct statfs *nsp, struct ostatfs *osp)
717 {
718 
719 	statfs_scale_blocks(nsp, LONG_MAX);
720 	bzero(osp, sizeof(*osp));
721 	osp->f_bsize = nsp->f_bsize;
722 	osp->f_iosize = MIN(nsp->f_iosize, LONG_MAX);
723 	osp->f_blocks = nsp->f_blocks;
724 	osp->f_bfree = nsp->f_bfree;
725 	osp->f_bavail = nsp->f_bavail;
726 	osp->f_files = MIN(nsp->f_files, LONG_MAX);
727 	osp->f_ffree = MIN(nsp->f_ffree, LONG_MAX);
728 	osp->f_owner = nsp->f_owner;
729 	osp->f_type = nsp->f_type;
730 	osp->f_flags = nsp->f_flags;
731 	osp->f_syncwrites = MIN(nsp->f_syncwrites, LONG_MAX);
732 	osp->f_asyncwrites = MIN(nsp->f_asyncwrites, LONG_MAX);
733 	osp->f_syncreads = MIN(nsp->f_syncreads, LONG_MAX);
734 	osp->f_asyncreads = MIN(nsp->f_asyncreads, LONG_MAX);
735 	strlcpy(osp->f_fstypename, nsp->f_fstypename,
736 	    MIN(MFSNAMELEN, OMFSNAMELEN));
737 	strlcpy(osp->f_mntonname, nsp->f_mntonname,
738 	    MIN(MNAMELEN, OMNAMELEN));
739 	strlcpy(osp->f_mntfromname, nsp->f_mntfromname,
740 	    MIN(MNAMELEN, OMNAMELEN));
741 	osp->f_fsid = nsp->f_fsid;
742 }
743 #endif /* COMPAT_FREEBSD4 */
744 
745 #if defined(COMPAT_FREEBSD11)
746 /*
747  * Get old format filesystem statistics.
748  */
749 static void freebsd11_cvtstatfs(struct statfs *, struct freebsd11_statfs *);
750 
751 int
freebsd11_statfs(struct thread * td,struct freebsd11_statfs_args * uap)752 freebsd11_statfs(struct thread *td, struct freebsd11_statfs_args *uap)
753 {
754 	struct freebsd11_statfs osb;
755 	struct statfs *sfp;
756 	int error;
757 
758 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
759 	error = kern_statfs(td, uap->path, UIO_USERSPACE, sfp);
760 	if (error == 0) {
761 		freebsd11_cvtstatfs(sfp, &osb);
762 		error = copyout(&osb, uap->buf, sizeof(osb));
763 	}
764 	free(sfp, M_STATFS);
765 	return (error);
766 }
767 
768 /*
769  * Get filesystem statistics.
770  */
771 int
freebsd11_fstatfs(struct thread * td,struct freebsd11_fstatfs_args * uap)772 freebsd11_fstatfs(struct thread *td, struct freebsd11_fstatfs_args *uap)
773 {
774 	struct freebsd11_statfs osb;
775 	struct statfs *sfp;
776 	int error;
777 
778 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
779 	error = kern_fstatfs(td, uap->fd, sfp);
780 	if (error == 0) {
781 		freebsd11_cvtstatfs(sfp, &osb);
782 		error = copyout(&osb, uap->buf, sizeof(osb));
783 	}
784 	free(sfp, M_STATFS);
785 	return (error);
786 }
787 
788 /*
789  * Get statistics on all filesystems.
790  */
791 int
freebsd11_getfsstat(struct thread * td,struct freebsd11_getfsstat_args * uap)792 freebsd11_getfsstat(struct thread *td, struct freebsd11_getfsstat_args *uap)
793 {
794 	return (kern_freebsd11_getfsstat(td, uap->buf, uap->bufsize, uap->mode));
795 }
796 
797 int
kern_freebsd11_getfsstat(struct thread * td,struct freebsd11_statfs * ubuf,long bufsize,int mode)798 kern_freebsd11_getfsstat(struct thread *td, struct freebsd11_statfs * ubuf,
799     long bufsize, int mode)
800 {
801 	struct freebsd11_statfs osb;
802 	struct statfs *buf, *sp;
803 	size_t count, size;
804 	int error;
805 
806 	if (bufsize < 0)
807 		return (EINVAL);
808 
809 	count = bufsize / sizeof(struct ostatfs);
810 	size = count * sizeof(struct statfs);
811 	error = kern_getfsstat(td, &buf, size, &count, UIO_SYSSPACE, mode);
812 	if (error == 0)
813 		td->td_retval[0] = count;
814 	if (size > 0) {
815 		sp = buf;
816 		while (count > 0 && error == 0) {
817 			freebsd11_cvtstatfs(sp, &osb);
818 			error = copyout(&osb, ubuf, sizeof(osb));
819 			sp++;
820 			ubuf++;
821 			count--;
822 		}
823 		free(buf, M_STATFS);
824 	}
825 	return (error);
826 }
827 
828 /*
829  * Implement fstatfs() for (NFS) file handles.
830  */
831 int
freebsd11_fhstatfs(struct thread * td,struct freebsd11_fhstatfs_args * uap)832 freebsd11_fhstatfs(struct thread *td, struct freebsd11_fhstatfs_args *uap)
833 {
834 	struct freebsd11_statfs osb;
835 	struct statfs *sfp;
836 	fhandle_t fh;
837 	int error;
838 
839 	error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t));
840 	if (error)
841 		return (error);
842 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
843 	error = kern_fhstatfs(td, fh, sfp);
844 	if (error == 0) {
845 		freebsd11_cvtstatfs(sfp, &osb);
846 		error = copyout(&osb, uap->buf, sizeof(osb));
847 	}
848 	free(sfp, M_STATFS);
849 	return (error);
850 }
851 
852 /*
853  * Convert a new format statfs structure to an old format statfs structure.
854  */
855 static void
freebsd11_cvtstatfs(struct statfs * nsp,struct freebsd11_statfs * osp)856 freebsd11_cvtstatfs(struct statfs *nsp, struct freebsd11_statfs *osp)
857 {
858 
859 	bzero(osp, sizeof(*osp));
860 	osp->f_version = FREEBSD11_STATFS_VERSION;
861 	osp->f_type = nsp->f_type;
862 	osp->f_flags = nsp->f_flags;
863 	osp->f_bsize = nsp->f_bsize;
864 	osp->f_iosize = nsp->f_iosize;
865 	osp->f_blocks = nsp->f_blocks;
866 	osp->f_bfree = nsp->f_bfree;
867 	osp->f_bavail = nsp->f_bavail;
868 	osp->f_files = nsp->f_files;
869 	osp->f_ffree = nsp->f_ffree;
870 	osp->f_syncwrites = nsp->f_syncwrites;
871 	osp->f_asyncwrites = nsp->f_asyncwrites;
872 	osp->f_syncreads = nsp->f_syncreads;
873 	osp->f_asyncreads = nsp->f_asyncreads;
874 	osp->f_namemax = nsp->f_namemax;
875 	osp->f_owner = nsp->f_owner;
876 	osp->f_fsid = nsp->f_fsid;
877 	strlcpy(osp->f_fstypename, nsp->f_fstypename,
878 	    MIN(MFSNAMELEN, sizeof(osp->f_fstypename)));
879 	strlcpy(osp->f_mntonname, nsp->f_mntonname,
880 	    MIN(MNAMELEN, sizeof(osp->f_mntonname)));
881 	strlcpy(osp->f_mntfromname, nsp->f_mntfromname,
882 	    MIN(MNAMELEN, sizeof(osp->f_mntfromname)));
883 }
884 #endif /* COMPAT_FREEBSD11 */
885 
886 /*
887  * Change current working directory to a given file descriptor.
888  */
889 #ifndef _SYS_SYSPROTO_H_
890 struct fchdir_args {
891 	int	fd;
892 };
893 #endif
894 int
sys_fchdir(struct thread * td,struct fchdir_args * uap)895 sys_fchdir(struct thread *td, struct fchdir_args *uap)
896 {
897 	struct vnode *vp, *tdp;
898 	struct mount *mp;
899 	struct file *fp;
900 	int error;
901 
902 	AUDIT_ARG_FD(uap->fd);
903 	error = getvnode_path(td, uap->fd, &cap_fchdir_rights,
904 	    &fp);
905 	if (error != 0)
906 		return (error);
907 	vp = fp->f_vnode;
908 	vrefact(vp);
909 	fdrop(fp, td);
910 	vn_lock(vp, LK_SHARED | LK_RETRY);
911 	AUDIT_ARG_VNODE1(vp);
912 	error = change_dir(vp, td);
913 	while (!error && (mp = vp->v_mountedhere) != NULL) {
914 		if (vfs_busy(mp, 0))
915 			continue;
916 		error = VFS_ROOT(mp, LK_SHARED, &tdp);
917 		vfs_unbusy(mp);
918 		if (error != 0)
919 			break;
920 		vput(vp);
921 		vp = tdp;
922 	}
923 	if (error != 0) {
924 		vput(vp);
925 		return (error);
926 	}
927 	VOP_UNLOCK(vp);
928 	pwd_chdir(td, vp);
929 	return (0);
930 }
931 
932 /*
933  * Change current working directory (``.'').
934  */
935 #ifndef _SYS_SYSPROTO_H_
936 struct chdir_args {
937 	char	*path;
938 };
939 #endif
940 int
sys_chdir(struct thread * td,struct chdir_args * uap)941 sys_chdir(struct thread *td, struct chdir_args *uap)
942 {
943 
944 	return (kern_chdir(td, uap->path, UIO_USERSPACE));
945 }
946 
947 int
kern_chdir(struct thread * td,const char * path,enum uio_seg pathseg)948 kern_chdir(struct thread *td, const char *path, enum uio_seg pathseg)
949 {
950 	struct nameidata nd;
951 	int error;
952 
953 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF | AUDITVNODE1,
954 	    pathseg, path);
955 	if ((error = namei(&nd)) != 0)
956 		return (error);
957 	if ((error = change_dir(nd.ni_vp, td)) != 0) {
958 		vput(nd.ni_vp);
959 		NDFREE_PNBUF(&nd);
960 		return (error);
961 	}
962 	VOP_UNLOCK(nd.ni_vp);
963 	NDFREE_PNBUF(&nd);
964 	pwd_chdir(td, nd.ni_vp);
965 	return (0);
966 }
967 
968 static int unprivileged_chroot = 0;
969 SYSCTL_INT(_security_bsd, OID_AUTO, unprivileged_chroot, CTLFLAG_RW,
970     &unprivileged_chroot, 0,
971     "Unprivileged processes can use chroot(2)");
972 /*
973  * Change notion of root (``/'') directory.
974  */
975 #ifndef _SYS_SYSPROTO_H_
976 struct chroot_args {
977 	char	*path;
978 };
979 #endif
980 int
sys_chroot(struct thread * td,struct chroot_args * uap)981 sys_chroot(struct thread *td, struct chroot_args *uap)
982 {
983 	struct nameidata nd;
984 	struct proc *p;
985 	int error;
986 
987 	error = priv_check(td, PRIV_VFS_CHROOT);
988 	if (error != 0) {
989 		p = td->td_proc;
990 		PROC_LOCK(p);
991 		if (unprivileged_chroot == 0 ||
992 		    (p->p_flag2 & P2_NO_NEW_PRIVS) == 0) {
993 			PROC_UNLOCK(p);
994 			return (error);
995 		}
996 		PROC_UNLOCK(p);
997 	}
998 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF | AUDITVNODE1,
999 	    UIO_USERSPACE, uap->path);
1000 	error = namei(&nd);
1001 	if (error != 0)
1002 		return (error);
1003 	NDFREE_PNBUF(&nd);
1004 	error = change_dir(nd.ni_vp, td);
1005 	if (error != 0)
1006 		goto e_vunlock;
1007 #ifdef MAC
1008 	error = mac_vnode_check_chroot(td->td_ucred, nd.ni_vp);
1009 	if (error != 0)
1010 		goto e_vunlock;
1011 #endif
1012 	VOP_UNLOCK(nd.ni_vp);
1013 	error = pwd_chroot(td, nd.ni_vp);
1014 	vrele(nd.ni_vp);
1015 	return (error);
1016 e_vunlock:
1017 	vput(nd.ni_vp);
1018 	return (error);
1019 }
1020 
1021 /*
1022  * Common routine for chroot and chdir.  Callers must provide a locked vnode
1023  * instance.
1024  */
1025 int
change_dir(struct vnode * vp,struct thread * td)1026 change_dir(struct vnode *vp, struct thread *td)
1027 {
1028 #ifdef MAC
1029 	int error;
1030 #endif
1031 
1032 	ASSERT_VOP_LOCKED(vp, "change_dir(): vp not locked");
1033 	if (vp->v_type != VDIR)
1034 		return (ENOTDIR);
1035 #ifdef MAC
1036 	error = mac_vnode_check_chdir(td->td_ucred, vp);
1037 	if (error != 0)
1038 		return (error);
1039 #endif
1040 	return (VOP_ACCESS(vp, VEXEC, td->td_ucred, td));
1041 }
1042 
1043 static __inline void
flags_to_rights(int flags,cap_rights_t * rightsp)1044 flags_to_rights(int flags, cap_rights_t *rightsp)
1045 {
1046 	if (flags & O_EXEC) {
1047 		cap_rights_set_one(rightsp, CAP_FEXECVE);
1048 		if (flags & O_PATH)
1049 			return;
1050 	} else {
1051 		switch ((flags & O_ACCMODE)) {
1052 		case O_RDONLY:
1053 			cap_rights_set_one(rightsp, CAP_READ);
1054 			break;
1055 		case O_RDWR:
1056 			cap_rights_set_one(rightsp, CAP_READ);
1057 			/* FALLTHROUGH */
1058 		case O_WRONLY:
1059 			cap_rights_set_one(rightsp, CAP_WRITE);
1060 			if (!(flags & (O_APPEND | O_TRUNC)))
1061 				cap_rights_set_one(rightsp, CAP_SEEK);
1062 			break;
1063 		}
1064 	}
1065 
1066 	if (flags & O_CREAT)
1067 		cap_rights_set_one(rightsp, CAP_CREATE);
1068 
1069 	if (flags & O_TRUNC)
1070 		cap_rights_set_one(rightsp, CAP_FTRUNCATE);
1071 
1072 	if (flags & (O_SYNC | O_FSYNC))
1073 		cap_rights_set_one(rightsp, CAP_FSYNC);
1074 
1075 	if (flags & (O_EXLOCK | O_SHLOCK))
1076 		cap_rights_set_one(rightsp, CAP_FLOCK);
1077 }
1078 
1079 /*
1080  * Check permissions, allocate an open file structure, and call the device
1081  * open routine if any.
1082  */
1083 #ifndef _SYS_SYSPROTO_H_
1084 struct open_args {
1085 	char	*path;
1086 	int	flags;
1087 	int	mode;
1088 };
1089 #endif
1090 int
sys_open(struct thread * td,struct open_args * uap)1091 sys_open(struct thread *td, struct open_args *uap)
1092 {
1093 
1094 	return (kern_openat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
1095 	    uap->flags, uap->mode));
1096 }
1097 
1098 #ifndef _SYS_SYSPROTO_H_
1099 struct openat_args {
1100 	int	fd;
1101 	char	*path;
1102 	int	flag;
1103 	int	mode;
1104 };
1105 #endif
1106 int
sys_openat(struct thread * td,struct openat_args * uap)1107 sys_openat(struct thread *td, struct openat_args *uap)
1108 {
1109 
1110 	AUDIT_ARG_FD(uap->fd);
1111 	return (kern_openat(td, uap->fd, uap->path, UIO_USERSPACE, uap->flag,
1112 	    uap->mode));
1113 }
1114 
1115 /*
1116  * If fpp != NULL, opened file is not installed into the file
1117  * descriptor table, instead it is returned in *fpp.  This is
1118  * incompatible with fdopen(), in which case we return EINVAL.
1119  */
1120 static int
openatfp(struct thread * td,int dirfd,const char * path,enum uio_seg pathseg,int flags,int mode,struct file ** fpp)1121 openatfp(struct thread *td, int dirfd, const char *path,
1122     enum uio_seg pathseg, int flags, int mode, struct file **fpp)
1123 {
1124 	struct proc *p;
1125 	struct filedesc *fdp;
1126 	struct pwddesc *pdp;
1127 	struct file *fp;
1128 	struct vnode *vp;
1129 	struct filecaps *fcaps;
1130 	struct nameidata nd;
1131 	cap_rights_t rights;
1132 	int cmode, error, indx;
1133 
1134 	indx = -1;
1135 	p = td->td_proc;
1136 	fdp = p->p_fd;
1137 	pdp = p->p_pd;
1138 
1139 	AUDIT_ARG_FFLAGS(flags);
1140 	AUDIT_ARG_MODE(mode);
1141 	cap_rights_init_one(&rights, CAP_LOOKUP);
1142 	flags_to_rights(flags, &rights);
1143 
1144 	/*
1145 	 * Only one of the O_EXEC, O_RDONLY, O_WRONLY and O_RDWR flags
1146 	 * may be specified.  On the other hand, for O_PATH any mode
1147 	 * except O_EXEC is ignored.
1148 	 */
1149 	if ((flags & O_PATH) != 0) {
1150 		flags &= ~(O_CREAT | O_ACCMODE);
1151 	} else if ((flags & O_EXEC) != 0) {
1152 		if (flags & O_ACCMODE)
1153 			return (EINVAL);
1154 	} else if ((flags & O_ACCMODE) == O_ACCMODE) {
1155 		return (EINVAL);
1156 	} else {
1157 		flags = FFLAGS(flags);
1158 	}
1159 
1160 	/*
1161 	 * Allocate a file structure. The descriptor to reference it
1162 	 * is allocated and used by finstall_refed() below.
1163 	 */
1164 	error = falloc_noinstall(td, &fp);
1165 	if (error != 0)
1166 		return (error);
1167 	/* Set the flags early so the finit in devfs can pick them up. */
1168 	fp->f_flag = flags & FMASK;
1169 	cmode = ((mode & ~pdp->pd_cmask) & ALLPERMS) & ~S_ISTXT;
1170 	NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | AUDITVNODE1 | WANTIOCTLCAPS,
1171 	    pathseg, path, dirfd, &rights);
1172 	td->td_dupfd = -1;		/* XXX check for fdopen */
1173 	error = vn_open_cred(&nd, &flags, cmode, VN_OPEN_WANTIOCTLCAPS,
1174 	    td->td_ucred, fp);
1175 	if (error != 0) {
1176 		/*
1177 		 * If the vn_open replaced the method vector, something
1178 		 * wonderous happened deep below and we just pass it up
1179 		 * pretending we know what we do.
1180 		 */
1181 		if (error == ENXIO && fp->f_ops != &badfileops) {
1182 			MPASS((flags & O_PATH) == 0);
1183 			goto success;
1184 		}
1185 
1186 		/*
1187 		 * Handle special fdopen() case. bleh.
1188 		 *
1189 		 * Don't do this for relative (capability) lookups; we don't
1190 		 * understand exactly what would happen, and we don't think
1191 		 * that it ever should.
1192 		 */
1193 		if ((nd.ni_resflags & NIRES_STRICTREL) == 0 &&
1194 		    (error == ENODEV || error == ENXIO) &&
1195 		    td->td_dupfd >= 0) {
1196 			MPASS(fpp == NULL);
1197 			error = dupfdopen(td, fdp, td->td_dupfd, flags, error,
1198 			    &indx);
1199 			if (error == 0)
1200 				goto success;
1201 		}
1202 
1203 		goto bad;
1204 	}
1205 	td->td_dupfd = 0;
1206 	NDFREE_PNBUF(&nd);
1207 	vp = nd.ni_vp;
1208 
1209 	/*
1210 	 * Store the vnode, for any f_type. Typically, the vnode use
1211 	 * count is decremented by direct call to vn_closefile() for
1212 	 * files that switched type in the cdevsw fdopen() method.
1213 	 */
1214 	fp->f_vnode = vp;
1215 
1216 	/*
1217 	 * If the file wasn't claimed by devfs bind it to the normal
1218 	 * vnode operations here.
1219 	 */
1220 	if (fp->f_ops == &badfileops) {
1221 		KASSERT(vp->v_type != VFIFO || (flags & O_PATH) != 0,
1222 		    ("Unexpected fifo fp %p vp %p", fp, vp));
1223 		if ((flags & O_PATH) != 0) {
1224 			finit(fp, (flags & FMASK) | (fp->f_flag & FKQALLOWED),
1225 			    DTYPE_VNODE, NULL, &path_fileops);
1226 		} else {
1227 			finit_vnode(fp, flags, NULL, &vnops);
1228 		}
1229 	}
1230 
1231 	VOP_UNLOCK(vp);
1232 	if (flags & O_TRUNC) {
1233 		error = fo_truncate(fp, 0, td->td_ucred, td);
1234 		if (error != 0)
1235 			goto bad;
1236 	}
1237 success:
1238 	if (fpp != NULL) {
1239 		MPASS(error == 0);
1240 		NDFREE_IOCTLCAPS(&nd);
1241 		*fpp = fp;
1242 		return (0);
1243 	}
1244 
1245 	/*
1246 	 * If we haven't already installed the FD (for dupfdopen), do so now.
1247 	 */
1248 	if (indx == -1) {
1249 #ifdef CAPABILITIES
1250 		if ((nd.ni_resflags & NIRES_STRICTREL) != 0)
1251 			fcaps = &nd.ni_filecaps;
1252 		else
1253 #endif
1254 			fcaps = NULL;
1255 		error = finstall_refed(td, fp, &indx, flags, fcaps);
1256 		/* On success finstall_refed() consumes fcaps. */
1257 		if (error != 0) {
1258 			goto bad;
1259 		}
1260 	} else {
1261 		NDFREE_IOCTLCAPS(&nd);
1262 		falloc_abort(td, fp);
1263 	}
1264 
1265 	td->td_retval[0] = indx;
1266 	return (0);
1267 bad:
1268 	KASSERT(indx == -1, ("indx=%d, should be -1", indx));
1269 	NDFREE_IOCTLCAPS(&nd);
1270 	falloc_abort(td, fp);
1271 	return (error);
1272 }
1273 
1274 int
kern_openat(struct thread * td,int dirfd,const char * path,enum uio_seg pathseg,int flags,int mode)1275 kern_openat(struct thread *td, int dirfd, const char *path,
1276     enum uio_seg pathseg, int flags, int mode)
1277 {
1278 	return (openatfp(td, dirfd, path, pathseg, flags, mode, NULL));
1279 }
1280 
1281 int
kern_openatfp(struct thread * td,int dirfd,const char * path,enum uio_seg pathseg,int flags,int mode,struct file ** fpp)1282 kern_openatfp(struct thread *td, int dirfd, const char *path,
1283     enum uio_seg pathseg, int flags, int mode, struct file **fpp)
1284 {
1285 	int error, old_dupfd;
1286 
1287 	old_dupfd = td->td_dupfd;
1288 	td->td_dupfd = -1;
1289 	error = openatfp(td, dirfd, path, pathseg, flags, mode, fpp);
1290 	td->td_dupfd = old_dupfd;
1291 	return (error);
1292 }
1293 
1294 #ifdef COMPAT_43
1295 /*
1296  * Create a file.
1297  */
1298 #ifndef _SYS_SYSPROTO_H_
1299 struct ocreat_args {
1300 	char	*path;
1301 	int	mode;
1302 };
1303 #endif
1304 int
ocreat(struct thread * td,struct ocreat_args * uap)1305 ocreat(struct thread *td, struct ocreat_args *uap)
1306 {
1307 
1308 	return (kern_openat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
1309 	    O_WRONLY | O_CREAT | O_TRUNC, uap->mode));
1310 }
1311 #endif /* COMPAT_43 */
1312 
1313 /*
1314  * Create a special file.
1315  */
1316 #ifndef _SYS_SYSPROTO_H_
1317 struct mknodat_args {
1318 	int	fd;
1319 	char	*path;
1320 	mode_t	mode;
1321 	dev_t	dev;
1322 };
1323 #endif
1324 int
sys_mknodat(struct thread * td,struct mknodat_args * uap)1325 sys_mknodat(struct thread *td, struct mknodat_args *uap)
1326 {
1327 
1328 	return (kern_mknodat(td, uap->fd, uap->path, UIO_USERSPACE, uap->mode,
1329 	    uap->dev));
1330 }
1331 
1332 #if defined(COMPAT_FREEBSD11)
1333 int
freebsd11_mknod(struct thread * td,struct freebsd11_mknod_args * uap)1334 freebsd11_mknod(struct thread *td,
1335     struct freebsd11_mknod_args *uap)
1336 {
1337 
1338 	return (kern_mknodat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
1339 	    uap->mode, uap->dev));
1340 }
1341 
1342 int
freebsd11_mknodat(struct thread * td,struct freebsd11_mknodat_args * uap)1343 freebsd11_mknodat(struct thread *td,
1344     struct freebsd11_mknodat_args *uap)
1345 {
1346 
1347 	return (kern_mknodat(td, uap->fd, uap->path, UIO_USERSPACE, uap->mode,
1348 	    uap->dev));
1349 }
1350 #endif /* COMPAT_FREEBSD11 */
1351 
1352 int
kern_mknodat(struct thread * td,int fd,const char * path,enum uio_seg pathseg,int mode,dev_t dev)1353 kern_mknodat(struct thread *td, int fd, const char *path, enum uio_seg pathseg,
1354     int mode, dev_t dev)
1355 {
1356 	struct vnode *vp;
1357 	struct mount *mp;
1358 	struct vattr vattr;
1359 	struct nameidata nd;
1360 	int error, whiteout = 0;
1361 
1362 	AUDIT_ARG_MODE(mode);
1363 	AUDIT_ARG_DEV(dev);
1364 	switch (mode & S_IFMT) {
1365 	case S_IFCHR:
1366 	case S_IFBLK:
1367 		error = priv_check(td, PRIV_VFS_MKNOD_DEV);
1368 		if (error == 0 && dev == VNOVAL)
1369 			error = EINVAL;
1370 		break;
1371 	case S_IFWHT:
1372 		error = priv_check(td, PRIV_VFS_MKNOD_WHT);
1373 		break;
1374 	case S_IFIFO:
1375 		if (dev == 0)
1376 			return (kern_mkfifoat(td, fd, path, pathseg, mode));
1377 		/* FALLTHROUGH */
1378 	default:
1379 		error = EINVAL;
1380 		break;
1381 	}
1382 	if (error != 0)
1383 		return (error);
1384 	NDPREINIT(&nd);
1385 restart:
1386 	bwillwrite();
1387 	NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | AUDITVNODE1 | NOCACHE,
1388 	    pathseg, path, fd, &cap_mknodat_rights);
1389 	if ((error = namei(&nd)) != 0)
1390 		return (error);
1391 	vp = nd.ni_vp;
1392 	if (vp != NULL) {
1393 		NDFREE_PNBUF(&nd);
1394 		if (vp == nd.ni_dvp)
1395 			vrele(nd.ni_dvp);
1396 		else
1397 			vput(nd.ni_dvp);
1398 		vrele(vp);
1399 		return (EEXIST);
1400 	} else {
1401 		VATTR_NULL(&vattr);
1402 		vattr.va_mode = (mode & ALLPERMS) &
1403 		    ~td->td_proc->p_pd->pd_cmask;
1404 		vattr.va_rdev = dev;
1405 		whiteout = 0;
1406 
1407 		switch (mode & S_IFMT) {
1408 		case S_IFCHR:
1409 			vattr.va_type = VCHR;
1410 			break;
1411 		case S_IFBLK:
1412 			vattr.va_type = VBLK;
1413 			break;
1414 		case S_IFWHT:
1415 			whiteout = 1;
1416 			break;
1417 		default:
1418 			panic("kern_mknod: invalid mode");
1419 		}
1420 	}
1421 	if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
1422 		NDFREE_PNBUF(&nd);
1423 		vput(nd.ni_dvp);
1424 		if ((error = vn_start_write(NULL, &mp, V_XSLEEP | V_PCATCH)) != 0)
1425 			return (error);
1426 		goto restart;
1427 	}
1428 #ifdef MAC
1429 	if (error == 0 && !whiteout)
1430 		error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp,
1431 		    &nd.ni_cnd, &vattr);
1432 #endif
1433 	if (error == 0) {
1434 		if (whiteout)
1435 			error = VOP_WHITEOUT(nd.ni_dvp, &nd.ni_cnd, CREATE);
1436 		else {
1437 			error = VOP_MKNOD(nd.ni_dvp, &nd.ni_vp,
1438 						&nd.ni_cnd, &vattr);
1439 		}
1440 	}
1441 	VOP_VPUT_PAIR(nd.ni_dvp, error == 0 && !whiteout ? &nd.ni_vp : NULL,
1442 	    true);
1443 	vn_finished_write(mp);
1444 	NDFREE_PNBUF(&nd);
1445 	if (error == ERELOOKUP)
1446 		goto restart;
1447 	return (error);
1448 }
1449 
1450 /*
1451  * Create a named pipe.
1452  */
1453 #ifndef _SYS_SYSPROTO_H_
1454 struct mkfifo_args {
1455 	char	*path;
1456 	int	mode;
1457 };
1458 #endif
1459 int
sys_mkfifo(struct thread * td,struct mkfifo_args * uap)1460 sys_mkfifo(struct thread *td, struct mkfifo_args *uap)
1461 {
1462 
1463 	return (kern_mkfifoat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
1464 	    uap->mode));
1465 }
1466 
1467 #ifndef _SYS_SYSPROTO_H_
1468 struct mkfifoat_args {
1469 	int	fd;
1470 	char	*path;
1471 	mode_t	mode;
1472 };
1473 #endif
1474 int
sys_mkfifoat(struct thread * td,struct mkfifoat_args * uap)1475 sys_mkfifoat(struct thread *td, struct mkfifoat_args *uap)
1476 {
1477 
1478 	return (kern_mkfifoat(td, uap->fd, uap->path, UIO_USERSPACE,
1479 	    uap->mode));
1480 }
1481 
1482 int
kern_mkfifoat(struct thread * td,int fd,const char * path,enum uio_seg pathseg,int mode)1483 kern_mkfifoat(struct thread *td, int fd, const char *path,
1484     enum uio_seg pathseg, int mode)
1485 {
1486 	struct mount *mp;
1487 	struct vattr vattr;
1488 	struct nameidata nd;
1489 	int error;
1490 
1491 	AUDIT_ARG_MODE(mode);
1492 	NDPREINIT(&nd);
1493 restart:
1494 	bwillwrite();
1495 	NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | AUDITVNODE1 | NOCACHE,
1496 	    pathseg, path, fd, &cap_mkfifoat_rights);
1497 	if ((error = namei(&nd)) != 0)
1498 		return (error);
1499 	if (nd.ni_vp != NULL) {
1500 		NDFREE_PNBUF(&nd);
1501 		if (nd.ni_vp == nd.ni_dvp)
1502 			vrele(nd.ni_dvp);
1503 		else
1504 			vput(nd.ni_dvp);
1505 		vrele(nd.ni_vp);
1506 		return (EEXIST);
1507 	}
1508 	if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
1509 		NDFREE_PNBUF(&nd);
1510 		vput(nd.ni_dvp);
1511 		if ((error = vn_start_write(NULL, &mp, V_XSLEEP | V_PCATCH)) != 0)
1512 			return (error);
1513 		goto restart;
1514 	}
1515 	VATTR_NULL(&vattr);
1516 	vattr.va_type = VFIFO;
1517 	vattr.va_mode = (mode & ALLPERMS) & ~td->td_proc->p_pd->pd_cmask;
1518 #ifdef MAC
1519 	error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
1520 	    &vattr);
1521 	if (error != 0)
1522 		goto out;
1523 #endif
1524 	error = VOP_MKNOD(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
1525 #ifdef MAC
1526 out:
1527 #endif
1528 	VOP_VPUT_PAIR(nd.ni_dvp, error == 0 ? &nd.ni_vp : NULL, true);
1529 	vn_finished_write(mp);
1530 	NDFREE_PNBUF(&nd);
1531 	if (error == ERELOOKUP)
1532 		goto restart;
1533 	return (error);
1534 }
1535 
1536 /*
1537  * Make a hard file link.
1538  */
1539 #ifndef _SYS_SYSPROTO_H_
1540 struct link_args {
1541 	char	*path;
1542 	char	*link;
1543 };
1544 #endif
1545 int
sys_link(struct thread * td,struct link_args * uap)1546 sys_link(struct thread *td, struct link_args *uap)
1547 {
1548 
1549 	return (kern_linkat(td, AT_FDCWD, AT_FDCWD, uap->path, uap->link,
1550 	    UIO_USERSPACE, AT_SYMLINK_FOLLOW));
1551 }
1552 
1553 #ifndef _SYS_SYSPROTO_H_
1554 struct linkat_args {
1555 	int	fd1;
1556 	char	*path1;
1557 	int	fd2;
1558 	char	*path2;
1559 	int	flag;
1560 };
1561 #endif
1562 int
sys_linkat(struct thread * td,struct linkat_args * uap)1563 sys_linkat(struct thread *td, struct linkat_args *uap)
1564 {
1565 
1566 	return (kern_linkat(td, uap->fd1, uap->fd2, uap->path1, uap->path2,
1567 	    UIO_USERSPACE, uap->flag));
1568 }
1569 
1570 int hardlink_check_uid = 0;
1571 SYSCTL_INT(_security_bsd, OID_AUTO, hardlink_check_uid, CTLFLAG_RW,
1572     &hardlink_check_uid, 0,
1573     "Unprivileged processes cannot create hard links to files owned by other "
1574     "users");
1575 static int hardlink_check_gid = 0;
1576 SYSCTL_INT(_security_bsd, OID_AUTO, hardlink_check_gid, CTLFLAG_RW,
1577     &hardlink_check_gid, 0,
1578     "Unprivileged processes cannot create hard links to files owned by other "
1579     "groups");
1580 
1581 static int
can_hardlink(struct vnode * vp,struct ucred * cred)1582 can_hardlink(struct vnode *vp, struct ucred *cred)
1583 {
1584 	struct vattr va;
1585 	int error;
1586 
1587 	if (!hardlink_check_uid && !hardlink_check_gid)
1588 		return (0);
1589 
1590 	error = VOP_GETATTR(vp, &va, cred);
1591 	if (error != 0)
1592 		return (error);
1593 
1594 	if (hardlink_check_uid && cred->cr_uid != va.va_uid) {
1595 		error = priv_check_cred(cred, PRIV_VFS_LINK);
1596 		if (error != 0)
1597 			return (error);
1598 	}
1599 
1600 	if (hardlink_check_gid && !groupmember(va.va_gid, cred)) {
1601 		error = priv_check_cred(cred, PRIV_VFS_LINK);
1602 		if (error != 0)
1603 			return (error);
1604 	}
1605 
1606 	return (0);
1607 }
1608 
1609 int
kern_linkat(struct thread * td,int fd1,int fd2,const char * path1,const char * path2,enum uio_seg segflag,int flag)1610 kern_linkat(struct thread *td, int fd1, int fd2, const char *path1,
1611     const char *path2, enum uio_seg segflag, int flag)
1612 {
1613 	struct nameidata nd;
1614 	int error;
1615 
1616 	if ((flag & ~(AT_SYMLINK_FOLLOW | AT_RESOLVE_BENEATH |
1617 	    AT_EMPTY_PATH)) != 0)
1618 		return (EINVAL);
1619 
1620 	NDPREINIT(&nd);
1621 	do {
1622 		bwillwrite();
1623 		NDINIT_ATRIGHTS(&nd, LOOKUP, AUDITVNODE1 | at2cnpflags(flag,
1624 		    AT_SYMLINK_FOLLOW | AT_RESOLVE_BENEATH | AT_EMPTY_PATH),
1625 		    segflag, path1, fd1, &cap_linkat_source_rights);
1626 		if ((error = namei(&nd)) != 0)
1627 			return (error);
1628 		NDFREE_PNBUF(&nd);
1629 		if ((nd.ni_resflags & NIRES_EMPTYPATH) != 0) {
1630 			error = priv_check(td, PRIV_VFS_FHOPEN);
1631 			if (error != 0) {
1632 				vrele(nd.ni_vp);
1633 				return (error);
1634 			}
1635 		}
1636 		error = kern_linkat_vp(td, nd.ni_vp, fd2, path2, segflag);
1637 	} while (error ==  EAGAIN || error == ERELOOKUP);
1638 	return (error);
1639 }
1640 
1641 static int
kern_linkat_vp(struct thread * td,struct vnode * vp,int fd,const char * path,enum uio_seg segflag)1642 kern_linkat_vp(struct thread *td, struct vnode *vp, int fd, const char *path,
1643     enum uio_seg segflag)
1644 {
1645 	struct nameidata nd;
1646 	struct mount *mp;
1647 	int error;
1648 
1649 	if (vp->v_type == VDIR) {
1650 		vrele(vp);
1651 		return (EPERM);		/* POSIX */
1652 	}
1653 	NDINIT_ATRIGHTS(&nd, CREATE,
1654 	    LOCKPARENT | AUDITVNODE2 | NOCACHE, segflag, path, fd,
1655 	    &cap_linkat_target_rights);
1656 	if ((error = namei(&nd)) == 0) {
1657 		if (nd.ni_vp != NULL) {
1658 			NDFREE_PNBUF(&nd);
1659 			if (nd.ni_dvp == nd.ni_vp)
1660 				vrele(nd.ni_dvp);
1661 			else
1662 				vput(nd.ni_dvp);
1663 			vrele(nd.ni_vp);
1664 			vrele(vp);
1665 			return (EEXIST);
1666 		} else if (nd.ni_dvp->v_mount != vp->v_mount) {
1667 			/*
1668 			 * Cross-device link.  No need to recheck
1669 			 * vp->v_type, since it cannot change, except
1670 			 * to VBAD.
1671 			 */
1672 			NDFREE_PNBUF(&nd);
1673 			vput(nd.ni_dvp);
1674 			vrele(vp);
1675 			return (EXDEV);
1676 		} else if (vn_lock(vp, LK_EXCLUSIVE) == 0) {
1677 			error = can_hardlink(vp, td->td_ucred);
1678 #ifdef MAC
1679 			if (error == 0)
1680 				error = mac_vnode_check_link(td->td_ucred,
1681 				    nd.ni_dvp, vp, &nd.ni_cnd);
1682 #endif
1683 			if (error != 0) {
1684 				vput(vp);
1685 				vput(nd.ni_dvp);
1686 				NDFREE_PNBUF(&nd);
1687 				return (error);
1688 			}
1689 			error = vn_start_write(vp, &mp, V_NOWAIT);
1690 			if (error != 0) {
1691 				vput(vp);
1692 				vput(nd.ni_dvp);
1693 				NDFREE_PNBUF(&nd);
1694 				error = vn_start_write(NULL, &mp,
1695 				    V_XSLEEP | V_PCATCH);
1696 				if (error != 0)
1697 					return (error);
1698 				return (EAGAIN);
1699 			}
1700 			error = VOP_LINK(nd.ni_dvp, vp, &nd.ni_cnd);
1701 			VOP_VPUT_PAIR(nd.ni_dvp, &vp, true);
1702 			vn_finished_write(mp);
1703 			NDFREE_PNBUF(&nd);
1704 			vp = NULL;
1705 		} else {
1706 			vput(nd.ni_dvp);
1707 			NDFREE_PNBUF(&nd);
1708 			vrele(vp);
1709 			return (EAGAIN);
1710 		}
1711 	}
1712 	if (vp != NULL)
1713 		vrele(vp);
1714 	return (error);
1715 }
1716 
1717 /*
1718  * Make a symbolic link.
1719  */
1720 #ifndef _SYS_SYSPROTO_H_
1721 struct symlink_args {
1722 	char	*path;
1723 	char	*link;
1724 };
1725 #endif
1726 int
sys_symlink(struct thread * td,struct symlink_args * uap)1727 sys_symlink(struct thread *td, struct symlink_args *uap)
1728 {
1729 
1730 	return (kern_symlinkat(td, uap->path, AT_FDCWD, uap->link,
1731 	    UIO_USERSPACE));
1732 }
1733 
1734 #ifndef _SYS_SYSPROTO_H_
1735 struct symlinkat_args {
1736 	char	*path;
1737 	int	fd;
1738 	char	*path2;
1739 };
1740 #endif
1741 int
sys_symlinkat(struct thread * td,struct symlinkat_args * uap)1742 sys_symlinkat(struct thread *td, struct symlinkat_args *uap)
1743 {
1744 
1745 	return (kern_symlinkat(td, uap->path1, uap->fd, uap->path2,
1746 	    UIO_USERSPACE));
1747 }
1748 
1749 int
kern_symlinkat(struct thread * td,const char * path1,int fd,const char * path2,enum uio_seg segflg)1750 kern_symlinkat(struct thread *td, const char *path1, int fd, const char *path2,
1751     enum uio_seg segflg)
1752 {
1753 	struct mount *mp;
1754 	struct vattr vattr;
1755 	const char *syspath;
1756 	char *tmppath;
1757 	struct nameidata nd;
1758 	int error;
1759 
1760 	if (segflg == UIO_SYSSPACE) {
1761 		syspath = path1;
1762 	} else {
1763 		tmppath = uma_zalloc(namei_zone, M_WAITOK);
1764 		if ((error = copyinstr(path1, tmppath, MAXPATHLEN, NULL)) != 0)
1765 			goto out;
1766 		syspath = tmppath;
1767 	}
1768 	AUDIT_ARG_TEXT(syspath);
1769 	NDPREINIT(&nd);
1770 restart:
1771 	bwillwrite();
1772 	NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | AUDITVNODE1 | NOCACHE, segflg,
1773 	    path2, fd, &cap_symlinkat_rights);
1774 	if ((error = namei(&nd)) != 0)
1775 		goto out;
1776 	if (nd.ni_vp) {
1777 		NDFREE_PNBUF(&nd);
1778 		if (nd.ni_vp == nd.ni_dvp)
1779 			vrele(nd.ni_dvp);
1780 		else
1781 			vput(nd.ni_dvp);
1782 		vrele(nd.ni_vp);
1783 		nd.ni_vp = NULL;
1784 		error = EEXIST;
1785 		goto out;
1786 	}
1787 	if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
1788 		NDFREE_PNBUF(&nd);
1789 		vput(nd.ni_dvp);
1790 		if ((error = vn_start_write(NULL, &mp, V_XSLEEP | V_PCATCH)) != 0)
1791 			goto out;
1792 		goto restart;
1793 	}
1794 	VATTR_NULL(&vattr);
1795 	vattr.va_mode = ACCESSPERMS &~ td->td_proc->p_pd->pd_cmask;
1796 #ifdef MAC
1797 	vattr.va_type = VLNK;
1798 	error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
1799 	    &vattr);
1800 	if (error != 0)
1801 		goto out2;
1802 #endif
1803 	error = VOP_SYMLINK(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr, syspath);
1804 #ifdef MAC
1805 out2:
1806 #endif
1807 	VOP_VPUT_PAIR(nd.ni_dvp, error == 0 ? &nd.ni_vp : NULL, true);
1808 	vn_finished_write(mp);
1809 	NDFREE_PNBUF(&nd);
1810 	if (error == ERELOOKUP)
1811 		goto restart;
1812 out:
1813 	if (segflg != UIO_SYSSPACE)
1814 		uma_zfree(namei_zone, tmppath);
1815 	return (error);
1816 }
1817 
1818 /*
1819  * Delete a whiteout from the filesystem.
1820  */
1821 #ifndef _SYS_SYSPROTO_H_
1822 struct undelete_args {
1823 	char *path;
1824 };
1825 #endif
1826 int
sys_undelete(struct thread * td,struct undelete_args * uap)1827 sys_undelete(struct thread *td, struct undelete_args *uap)
1828 {
1829 	struct mount *mp;
1830 	struct nameidata nd;
1831 	int error;
1832 
1833 	NDPREINIT(&nd);
1834 restart:
1835 	bwillwrite();
1836 	NDINIT(&nd, DELETE, LOCKPARENT | DOWHITEOUT | AUDITVNODE1,
1837 	    UIO_USERSPACE, uap->path);
1838 	error = namei(&nd);
1839 	if (error != 0)
1840 		return (error);
1841 
1842 	if (nd.ni_vp != NULLVP || !(nd.ni_cnd.cn_flags & ISWHITEOUT)) {
1843 		NDFREE_PNBUF(&nd);
1844 		if (nd.ni_vp == nd.ni_dvp)
1845 			vrele(nd.ni_dvp);
1846 		else
1847 			vput(nd.ni_dvp);
1848 		if (nd.ni_vp)
1849 			vrele(nd.ni_vp);
1850 		return (EEXIST);
1851 	}
1852 	if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
1853 		NDFREE_PNBUF(&nd);
1854 		vput(nd.ni_dvp);
1855 		if ((error = vn_start_write(NULL, &mp, V_XSLEEP | V_PCATCH)) != 0)
1856 			return (error);
1857 		goto restart;
1858 	}
1859 	error = VOP_WHITEOUT(nd.ni_dvp, &nd.ni_cnd, DELETE);
1860 	NDFREE_PNBUF(&nd);
1861 	vput(nd.ni_dvp);
1862 	vn_finished_write(mp);
1863 	if (error == ERELOOKUP)
1864 		goto restart;
1865 	return (error);
1866 }
1867 
1868 /*
1869  * Delete a name from the filesystem.
1870  */
1871 #ifndef _SYS_SYSPROTO_H_
1872 struct unlink_args {
1873 	char	*path;
1874 };
1875 #endif
1876 int
sys_unlink(struct thread * td,struct unlink_args * uap)1877 sys_unlink(struct thread *td, struct unlink_args *uap)
1878 {
1879 
1880 	return (kern_funlinkat(td, AT_FDCWD, uap->path, FD_NONE, UIO_USERSPACE,
1881 	    0, 0));
1882 }
1883 
1884 static int
kern_funlinkat_ex(struct thread * td,int dfd,const char * path,int fd,int flag,enum uio_seg pathseg,ino_t oldinum)1885 kern_funlinkat_ex(struct thread *td, int dfd, const char *path, int fd,
1886     int flag, enum uio_seg pathseg, ino_t oldinum)
1887 {
1888 
1889 	if ((flag & ~(AT_REMOVEDIR | AT_RESOLVE_BENEATH)) != 0)
1890 		return (EINVAL);
1891 
1892 	if ((flag & AT_REMOVEDIR) != 0)
1893 		return (kern_frmdirat(td, dfd, path, fd, UIO_USERSPACE, 0));
1894 
1895 	return (kern_funlinkat(td, dfd, path, fd, UIO_USERSPACE, 0, 0));
1896 }
1897 
1898 #ifndef _SYS_SYSPROTO_H_
1899 struct unlinkat_args {
1900 	int	fd;
1901 	char	*path;
1902 	int	flag;
1903 };
1904 #endif
1905 int
sys_unlinkat(struct thread * td,struct unlinkat_args * uap)1906 sys_unlinkat(struct thread *td, struct unlinkat_args *uap)
1907 {
1908 
1909 	return (kern_funlinkat_ex(td, uap->fd, uap->path, FD_NONE, uap->flag,
1910 	    UIO_USERSPACE, 0));
1911 }
1912 
1913 #ifndef _SYS_SYSPROTO_H_
1914 struct funlinkat_args {
1915 	int		dfd;
1916 	const char	*path;
1917 	int		fd;
1918 	int		flag;
1919 };
1920 #endif
1921 int
sys_funlinkat(struct thread * td,struct funlinkat_args * uap)1922 sys_funlinkat(struct thread *td, struct funlinkat_args *uap)
1923 {
1924 
1925 	return (kern_funlinkat_ex(td, uap->dfd, uap->path, uap->fd, uap->flag,
1926 	    UIO_USERSPACE, 0));
1927 }
1928 
1929 int
kern_funlinkat(struct thread * td,int dfd,const char * path,int fd,enum uio_seg pathseg,int flag,ino_t oldinum)1930 kern_funlinkat(struct thread *td, int dfd, const char *path, int fd,
1931     enum uio_seg pathseg, int flag, ino_t oldinum)
1932 {
1933 	struct mount *mp;
1934 	struct file *fp;
1935 	struct vnode *vp;
1936 	struct nameidata nd;
1937 	struct stat sb;
1938 	int error;
1939 
1940 	fp = NULL;
1941 	if (fd != FD_NONE) {
1942 		error = getvnode_path(td, fd, &cap_no_rights, &fp);
1943 		if (error != 0)
1944 			return (error);
1945 	}
1946 
1947 	NDPREINIT(&nd);
1948 restart:
1949 	bwillwrite();
1950 	NDINIT_ATRIGHTS(&nd, DELETE, LOCKPARENT | LOCKLEAF | AUDITVNODE1 |
1951 	    at2cnpflags(flag, AT_RESOLVE_BENEATH),
1952 	    pathseg, path, dfd, &cap_unlinkat_rights);
1953 	if ((error = namei(&nd)) != 0) {
1954 		if (error == EINVAL)
1955 			error = EPERM;
1956 		goto fdout;
1957 	}
1958 	vp = nd.ni_vp;
1959 	if (vp->v_type == VDIR && oldinum == 0) {
1960 		error = EPERM;		/* POSIX */
1961 	} else if (oldinum != 0 &&
1962 	    ((error = VOP_STAT(vp, &sb, td->td_ucred, NOCRED)) == 0) &&
1963 	    sb.st_ino != oldinum) {
1964 		error = EIDRM;	/* Identifier removed */
1965 	} else if (fp != NULL && fp->f_vnode != vp) {
1966 		if (VN_IS_DOOMED(fp->f_vnode))
1967 			error = EBADF;
1968 		else
1969 			error = EDEADLK;
1970 	} else {
1971 		/*
1972 		 * The root of a mounted filesystem cannot be deleted.
1973 		 *
1974 		 * XXX: can this only be a VDIR case?
1975 		 */
1976 		if (vp->v_vflag & VV_ROOT)
1977 			error = EBUSY;
1978 	}
1979 	if (error == 0) {
1980 		if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
1981 			NDFREE_PNBUF(&nd);
1982 			vput(nd.ni_dvp);
1983 			if (vp == nd.ni_dvp)
1984 				vrele(vp);
1985 			else
1986 				vput(vp);
1987 			if ((error = vn_start_write(NULL, &mp,
1988 			    V_XSLEEP | V_PCATCH)) != 0) {
1989 				goto fdout;
1990 			}
1991 			goto restart;
1992 		}
1993 #ifdef MAC
1994 		error = mac_vnode_check_unlink(td->td_ucred, nd.ni_dvp, vp,
1995 		    &nd.ni_cnd);
1996 		if (error != 0)
1997 			goto out;
1998 #endif
1999 		vfs_notify_upper(vp, VFS_NOTIFY_UPPER_UNLINK);
2000 		error = VOP_REMOVE(nd.ni_dvp, vp, &nd.ni_cnd);
2001 #ifdef MAC
2002 out:
2003 #endif
2004 		vn_finished_write(mp);
2005 	}
2006 	NDFREE_PNBUF(&nd);
2007 	vput(nd.ni_dvp);
2008 	if (vp == nd.ni_dvp)
2009 		vrele(vp);
2010 	else
2011 		vput(vp);
2012 	if (error == ERELOOKUP)
2013 		goto restart;
2014 fdout:
2015 	if (fp != NULL)
2016 		fdrop(fp, td);
2017 	return (error);
2018 }
2019 
2020 /*
2021  * Reposition read/write file offset.
2022  */
2023 #ifndef _SYS_SYSPROTO_H_
2024 struct lseek_args {
2025 	int	fd;
2026 	int	pad;
2027 	off_t	offset;
2028 	int	whence;
2029 };
2030 #endif
2031 int
sys_lseek(struct thread * td,struct lseek_args * uap)2032 sys_lseek(struct thread *td, struct lseek_args *uap)
2033 {
2034 
2035 	return (kern_lseek(td, uap->fd, uap->offset, uap->whence));
2036 }
2037 
2038 int
kern_lseek(struct thread * td,int fd,off_t offset,int whence)2039 kern_lseek(struct thread *td, int fd, off_t offset, int whence)
2040 {
2041 	struct file *fp;
2042 	int error;
2043 
2044 	AUDIT_ARG_FD(fd);
2045 	error = fget(td, fd, &cap_seek_rights, &fp);
2046 	if (error != 0)
2047 		return (error);
2048 	error = (fp->f_ops->fo_flags & DFLAG_SEEKABLE) != 0 ?
2049 	    fo_seek(fp, offset, whence, td) : ESPIPE;
2050 	fdrop(fp, td);
2051 	return (error);
2052 }
2053 
2054 #if defined(COMPAT_43)
2055 /*
2056  * Reposition read/write file offset.
2057  */
2058 #ifndef _SYS_SYSPROTO_H_
2059 struct olseek_args {
2060 	int	fd;
2061 	long	offset;
2062 	int	whence;
2063 };
2064 #endif
2065 int
olseek(struct thread * td,struct olseek_args * uap)2066 olseek(struct thread *td, struct olseek_args *uap)
2067 {
2068 
2069 	return (kern_lseek(td, uap->fd, uap->offset, uap->whence));
2070 }
2071 #endif /* COMPAT_43 */
2072 
2073 #if defined(COMPAT_FREEBSD6)
2074 /* Version with the 'pad' argument */
2075 int
freebsd6_lseek(struct thread * td,struct freebsd6_lseek_args * uap)2076 freebsd6_lseek(struct thread *td, struct freebsd6_lseek_args *uap)
2077 {
2078 
2079 	return (kern_lseek(td, uap->fd, uap->offset, uap->whence));
2080 }
2081 #endif
2082 
2083 /*
2084  * Check access permissions using passed credentials.
2085  */
2086 static int
vn_access(struct vnode * vp,int user_flags,struct ucred * cred,struct thread * td)2087 vn_access(struct vnode *vp, int user_flags, struct ucred *cred,
2088      struct thread *td)
2089 {
2090 	accmode_t accmode;
2091 	int error;
2092 
2093 	/* Flags == 0 means only check for existence. */
2094 	if (user_flags == 0)
2095 		return (0);
2096 
2097 	accmode = 0;
2098 	if (user_flags & R_OK)
2099 		accmode |= VREAD;
2100 	if (user_flags & W_OK)
2101 		accmode |= VWRITE;
2102 	if (user_flags & X_OK)
2103 		accmode |= VEXEC;
2104 #ifdef MAC
2105 	error = mac_vnode_check_access(cred, vp, accmode);
2106 	if (error != 0)
2107 		return (error);
2108 #endif
2109 	if ((accmode & VWRITE) == 0 || (error = vn_writechk(vp)) == 0)
2110 		error = VOP_ACCESS(vp, accmode, cred, td);
2111 	return (error);
2112 }
2113 
2114 /*
2115  * Check access permissions using "real" credentials.
2116  */
2117 #ifndef _SYS_SYSPROTO_H_
2118 struct access_args {
2119 	char	*path;
2120 	int	amode;
2121 };
2122 #endif
2123 int
sys_access(struct thread * td,struct access_args * uap)2124 sys_access(struct thread *td, struct access_args *uap)
2125 {
2126 
2127 	return (kern_accessat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
2128 	    0, uap->amode));
2129 }
2130 
2131 #ifndef _SYS_SYSPROTO_H_
2132 struct faccessat_args {
2133 	int	dirfd;
2134 	char	*path;
2135 	int	amode;
2136 	int	flag;
2137 }
2138 #endif
2139 int
sys_faccessat(struct thread * td,struct faccessat_args * uap)2140 sys_faccessat(struct thread *td, struct faccessat_args *uap)
2141 {
2142 
2143 	return (kern_accessat(td, uap->fd, uap->path, UIO_USERSPACE, uap->flag,
2144 	    uap->amode));
2145 }
2146 
2147 int
kern_accessat(struct thread * td,int fd,const char * path,enum uio_seg pathseg,int flag,int amode)2148 kern_accessat(struct thread *td, int fd, const char *path,
2149     enum uio_seg pathseg, int flag, int amode)
2150 {
2151 	struct ucred *cred, *usecred;
2152 	struct vnode *vp;
2153 	struct nameidata nd;
2154 	int error;
2155 
2156 	if ((flag & ~(AT_EACCESS | AT_RESOLVE_BENEATH | AT_EMPTY_PATH |
2157 	    AT_SYMLINK_NOFOLLOW)) != 0)
2158 		return (EINVAL);
2159 	if (amode != F_OK && (amode & ~(R_OK | W_OK | X_OK)) != 0)
2160 		return (EINVAL);
2161 
2162 	/*
2163 	 * Create and modify a temporary credential instead of one that
2164 	 * is potentially shared (if we need one).
2165 	 */
2166 	cred = td->td_ucred;
2167 	if ((flag & AT_EACCESS) == 0 &&
2168 	    ((cred->cr_uid != cred->cr_ruid ||
2169 	    cred->cr_rgid != cred->cr_groups[0]))) {
2170 		usecred = crdup(cred);
2171 		usecred->cr_uid = cred->cr_ruid;
2172 		usecred->cr_groups[0] = cred->cr_rgid;
2173 		td->td_ucred = usecred;
2174 	} else
2175 		usecred = cred;
2176 	AUDIT_ARG_VALUE(amode);
2177 	NDINIT_ATRIGHTS(&nd, LOOKUP, LOCKSHARED | LOCKLEAF |
2178 	    AUDITVNODE1 | at2cnpflags(flag, AT_RESOLVE_BENEATH | AT_SYMLINK_NOFOLLOW |
2179 	    AT_EMPTY_PATH), pathseg, path, fd, &cap_fstat_rights);
2180 	if ((error = namei(&nd)) != 0)
2181 		goto out;
2182 	vp = nd.ni_vp;
2183 
2184 	error = vn_access(vp, amode, usecred, td);
2185 	NDFREE_PNBUF(&nd);
2186 	vput(vp);
2187 out:
2188 	if (usecred != cred) {
2189 		td->td_ucred = cred;
2190 		crfree(usecred);
2191 	}
2192 	return (error);
2193 }
2194 
2195 /*
2196  * Check access permissions using "effective" credentials.
2197  */
2198 #ifndef _SYS_SYSPROTO_H_
2199 struct eaccess_args {
2200 	char	*path;
2201 	int	amode;
2202 };
2203 #endif
2204 int
sys_eaccess(struct thread * td,struct eaccess_args * uap)2205 sys_eaccess(struct thread *td, struct eaccess_args *uap)
2206 {
2207 
2208 	return (kern_accessat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
2209 	    AT_EACCESS, uap->amode));
2210 }
2211 
2212 #if defined(COMPAT_43)
2213 /*
2214  * Get file status; this version follows links.
2215  */
2216 #ifndef _SYS_SYSPROTO_H_
2217 struct ostat_args {
2218 	char	*path;
2219 	struct ostat *ub;
2220 };
2221 #endif
2222 int
ostat(struct thread * td,struct ostat_args * uap)2223 ostat(struct thread *td, struct ostat_args *uap)
2224 {
2225 	struct stat sb;
2226 	struct ostat osb;
2227 	int error;
2228 
2229 	error = kern_statat(td, 0, AT_FDCWD, uap->path, UIO_USERSPACE, &sb);
2230 	if (error != 0)
2231 		return (error);
2232 	cvtstat(&sb, &osb);
2233 	return (copyout(&osb, uap->ub, sizeof (osb)));
2234 }
2235 
2236 /*
2237  * Get file status; this version does not follow links.
2238  */
2239 #ifndef _SYS_SYSPROTO_H_
2240 struct olstat_args {
2241 	char	*path;
2242 	struct ostat *ub;
2243 };
2244 #endif
2245 int
olstat(struct thread * td,struct olstat_args * uap)2246 olstat(struct thread *td, struct olstat_args *uap)
2247 {
2248 	struct stat sb;
2249 	struct ostat osb;
2250 	int error;
2251 
2252 	error = kern_statat(td, AT_SYMLINK_NOFOLLOW, AT_FDCWD, uap->path,
2253 	    UIO_USERSPACE, &sb);
2254 	if (error != 0)
2255 		return (error);
2256 	cvtstat(&sb, &osb);
2257 	return (copyout(&osb, uap->ub, sizeof (osb)));
2258 }
2259 
2260 /*
2261  * Convert from an old to a new stat structure.
2262  * XXX: many values are blindly truncated.
2263  */
2264 void
cvtstat(struct stat * st,struct ostat * ost)2265 cvtstat(struct stat *st, struct ostat *ost)
2266 {
2267 
2268 	bzero(ost, sizeof(*ost));
2269 	ost->st_dev = st->st_dev;
2270 	ost->st_ino = st->st_ino;
2271 	ost->st_mode = st->st_mode;
2272 	ost->st_nlink = st->st_nlink;
2273 	ost->st_uid = st->st_uid;
2274 	ost->st_gid = st->st_gid;
2275 	ost->st_rdev = st->st_rdev;
2276 	ost->st_size = MIN(st->st_size, INT32_MAX);
2277 	ost->st_atim = st->st_atim;
2278 	ost->st_mtim = st->st_mtim;
2279 	ost->st_ctim = st->st_ctim;
2280 	ost->st_blksize = st->st_blksize;
2281 	ost->st_blocks = st->st_blocks;
2282 	ost->st_flags = st->st_flags;
2283 	ost->st_gen = st->st_gen;
2284 }
2285 #endif /* COMPAT_43 */
2286 
2287 #if defined(COMPAT_43) || defined(COMPAT_FREEBSD11)
2288 int ino64_trunc_error;
2289 SYSCTL_INT(_vfs, OID_AUTO, ino64_trunc_error, CTLFLAG_RW,
2290     &ino64_trunc_error, 0,
2291     "Error on truncation of device, file or inode number, or link count");
2292 
2293 int
freebsd11_cvtstat(struct stat * st,struct freebsd11_stat * ost)2294 freebsd11_cvtstat(struct stat *st, struct freebsd11_stat *ost)
2295 {
2296 
2297 	ost->st_dev = st->st_dev;
2298 	if (ost->st_dev != st->st_dev) {
2299 		switch (ino64_trunc_error) {
2300 		default:
2301 			/*
2302 			 * Since dev_t is almost raw, don't clamp to the
2303 			 * maximum for case 2, but ignore the error.
2304 			 */
2305 			break;
2306 		case 1:
2307 			return (EOVERFLOW);
2308 		}
2309 	}
2310 	ost->st_ino = st->st_ino;
2311 	if (ost->st_ino != st->st_ino) {
2312 		switch (ino64_trunc_error) {
2313 		default:
2314 		case 0:
2315 			break;
2316 		case 1:
2317 			return (EOVERFLOW);
2318 		case 2:
2319 			ost->st_ino = UINT32_MAX;
2320 			break;
2321 		}
2322 	}
2323 	ost->st_mode = st->st_mode;
2324 	ost->st_nlink = st->st_nlink;
2325 	if (ost->st_nlink != st->st_nlink) {
2326 		switch (ino64_trunc_error) {
2327 		default:
2328 		case 0:
2329 			break;
2330 		case 1:
2331 			return (EOVERFLOW);
2332 		case 2:
2333 			ost->st_nlink = UINT16_MAX;
2334 			break;
2335 		}
2336 	}
2337 	ost->st_uid = st->st_uid;
2338 	ost->st_gid = st->st_gid;
2339 	ost->st_rdev = st->st_rdev;
2340 	if (ost->st_rdev != st->st_rdev) {
2341 		switch (ino64_trunc_error) {
2342 		default:
2343 			break;
2344 		case 1:
2345 			return (EOVERFLOW);
2346 		}
2347 	}
2348 	ost->st_atim = st->st_atim;
2349 	ost->st_mtim = st->st_mtim;
2350 	ost->st_ctim = st->st_ctim;
2351 	ost->st_size = st->st_size;
2352 	ost->st_blocks = st->st_blocks;
2353 	ost->st_blksize = st->st_blksize;
2354 	ost->st_flags = st->st_flags;
2355 	ost->st_gen = st->st_gen;
2356 	ost->st_lspare = 0;
2357 	ost->st_birthtim = st->st_birthtim;
2358 	bzero((char *)&ost->st_birthtim + sizeof(ost->st_birthtim),
2359 	    sizeof(*ost) - offsetof(struct freebsd11_stat,
2360 	    st_birthtim) - sizeof(ost->st_birthtim));
2361 	return (0);
2362 }
2363 
2364 int
freebsd11_stat(struct thread * td,struct freebsd11_stat_args * uap)2365 freebsd11_stat(struct thread *td, struct freebsd11_stat_args* uap)
2366 {
2367 	struct stat sb;
2368 	struct freebsd11_stat osb;
2369 	int error;
2370 
2371 	error = kern_statat(td, 0, AT_FDCWD, uap->path, UIO_USERSPACE, &sb);
2372 	if (error != 0)
2373 		return (error);
2374 	error = freebsd11_cvtstat(&sb, &osb);
2375 	if (error == 0)
2376 		error = copyout(&osb, uap->ub, sizeof(osb));
2377 	return (error);
2378 }
2379 
2380 int
freebsd11_lstat(struct thread * td,struct freebsd11_lstat_args * uap)2381 freebsd11_lstat(struct thread *td, struct freebsd11_lstat_args* uap)
2382 {
2383 	struct stat sb;
2384 	struct freebsd11_stat osb;
2385 	int error;
2386 
2387 	error = kern_statat(td, AT_SYMLINK_NOFOLLOW, AT_FDCWD, uap->path,
2388 	    UIO_USERSPACE, &sb);
2389 	if (error != 0)
2390 		return (error);
2391 	error = freebsd11_cvtstat(&sb, &osb);
2392 	if (error == 0)
2393 		error = copyout(&osb, uap->ub, sizeof(osb));
2394 	return (error);
2395 }
2396 
2397 int
freebsd11_fhstat(struct thread * td,struct freebsd11_fhstat_args * uap)2398 freebsd11_fhstat(struct thread *td, struct freebsd11_fhstat_args* uap)
2399 {
2400 	struct fhandle fh;
2401 	struct stat sb;
2402 	struct freebsd11_stat osb;
2403 	int error;
2404 
2405 	error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t));
2406 	if (error != 0)
2407 		return (error);
2408 	error = kern_fhstat(td, fh, &sb);
2409 	if (error != 0)
2410 		return (error);
2411 	error = freebsd11_cvtstat(&sb, &osb);
2412 	if (error == 0)
2413 		error = copyout(&osb, uap->sb, sizeof(osb));
2414 	return (error);
2415 }
2416 
2417 int
freebsd11_fstatat(struct thread * td,struct freebsd11_fstatat_args * uap)2418 freebsd11_fstatat(struct thread *td, struct freebsd11_fstatat_args* uap)
2419 {
2420 	struct stat sb;
2421 	struct freebsd11_stat osb;
2422 	int error;
2423 
2424 	error = kern_statat(td, uap->flag, uap->fd, uap->path,
2425 	    UIO_USERSPACE, &sb);
2426 	if (error != 0)
2427 		return (error);
2428 	error = freebsd11_cvtstat(&sb, &osb);
2429 	if (error == 0)
2430 		error = copyout(&osb, uap->buf, sizeof(osb));
2431 	return (error);
2432 }
2433 #endif	/* COMPAT_FREEBSD11 */
2434 
2435 /*
2436  * Get file status
2437  */
2438 #ifndef _SYS_SYSPROTO_H_
2439 struct fstatat_args {
2440 	int	fd;
2441 	char	*path;
2442 	struct stat	*buf;
2443 	int	flag;
2444 }
2445 #endif
2446 int
sys_fstatat(struct thread * td,struct fstatat_args * uap)2447 sys_fstatat(struct thread *td, struct fstatat_args *uap)
2448 {
2449 	struct stat sb;
2450 	int error;
2451 
2452 	error = kern_statat(td, uap->flag, uap->fd, uap->path,
2453 	    UIO_USERSPACE, &sb);
2454 	if (error == 0)
2455 		error = copyout(&sb, uap->buf, sizeof (sb));
2456 	return (error);
2457 }
2458 
2459 int
kern_statat(struct thread * td,int flag,int fd,const char * path,enum uio_seg pathseg,struct stat * sbp)2460 kern_statat(struct thread *td, int flag, int fd, const char *path,
2461     enum uio_seg pathseg, struct stat *sbp)
2462 {
2463 	struct nameidata nd;
2464 	int error;
2465 
2466 	if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_RESOLVE_BENEATH |
2467 	    AT_EMPTY_PATH)) != 0)
2468 		return (EINVAL);
2469 
2470 	NDINIT_ATRIGHTS(&nd, LOOKUP, at2cnpflags(flag, AT_RESOLVE_BENEATH |
2471 	    AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH) | LOCKSHARED | LOCKLEAF |
2472 	    AUDITVNODE1, pathseg, path, fd, &cap_fstat_rights);
2473 
2474 	if ((error = namei(&nd)) != 0) {
2475 		if (error == ENOTDIR &&
2476 		    (nd.ni_resflags & NIRES_EMPTYPATH) != 0)
2477 			error = kern_fstat(td, fd, sbp);
2478 		return (error);
2479 	}
2480 	error = VOP_STAT(nd.ni_vp, sbp, td->td_ucred, NOCRED);
2481 	NDFREE_PNBUF(&nd);
2482 	vput(nd.ni_vp);
2483 #ifdef __STAT_TIME_T_EXT
2484 	sbp->st_atim_ext = 0;
2485 	sbp->st_mtim_ext = 0;
2486 	sbp->st_ctim_ext = 0;
2487 	sbp->st_btim_ext = 0;
2488 #endif
2489 #ifdef KTRACE
2490 	if (KTRPOINT(td, KTR_STRUCT))
2491 		ktrstat_error(sbp, error);
2492 #endif
2493 	return (error);
2494 }
2495 
2496 #if defined(COMPAT_FREEBSD11)
2497 /*
2498  * Implementation of the NetBSD [l]stat() functions.
2499  */
2500 int
freebsd11_cvtnstat(struct stat * sb,struct nstat * nsb)2501 freebsd11_cvtnstat(struct stat *sb, struct nstat *nsb)
2502 {
2503 	struct freebsd11_stat sb11;
2504 	int error;
2505 
2506 	error = freebsd11_cvtstat(sb, &sb11);
2507 	if (error != 0)
2508 		return (error);
2509 
2510 	bzero(nsb, sizeof(*nsb));
2511 	CP(sb11, *nsb, st_dev);
2512 	CP(sb11, *nsb, st_ino);
2513 	CP(sb11, *nsb, st_mode);
2514 	CP(sb11, *nsb, st_nlink);
2515 	CP(sb11, *nsb, st_uid);
2516 	CP(sb11, *nsb, st_gid);
2517 	CP(sb11, *nsb, st_rdev);
2518 	CP(sb11, *nsb, st_atim);
2519 	CP(sb11, *nsb, st_mtim);
2520 	CP(sb11, *nsb, st_ctim);
2521 	CP(sb11, *nsb, st_size);
2522 	CP(sb11, *nsb, st_blocks);
2523 	CP(sb11, *nsb, st_blksize);
2524 	CP(sb11, *nsb, st_flags);
2525 	CP(sb11, *nsb, st_gen);
2526 	CP(sb11, *nsb, st_birthtim);
2527 	return (0);
2528 }
2529 
2530 #ifndef _SYS_SYSPROTO_H_
2531 struct freebsd11_nstat_args {
2532 	char	*path;
2533 	struct nstat *ub;
2534 };
2535 #endif
2536 int
freebsd11_nstat(struct thread * td,struct freebsd11_nstat_args * uap)2537 freebsd11_nstat(struct thread *td, struct freebsd11_nstat_args *uap)
2538 {
2539 	struct stat sb;
2540 	struct nstat nsb;
2541 	int error;
2542 
2543 	error = kern_statat(td, 0, AT_FDCWD, uap->path, UIO_USERSPACE, &sb);
2544 	if (error != 0)
2545 		return (error);
2546 	error = freebsd11_cvtnstat(&sb, &nsb);
2547 	if (error == 0)
2548 		error = copyout(&nsb, uap->ub, sizeof (nsb));
2549 	return (error);
2550 }
2551 
2552 /*
2553  * NetBSD lstat.  Get file status; this version does not follow links.
2554  */
2555 #ifndef _SYS_SYSPROTO_H_
2556 struct freebsd11_nlstat_args {
2557 	char	*path;
2558 	struct nstat *ub;
2559 };
2560 #endif
2561 int
freebsd11_nlstat(struct thread * td,struct freebsd11_nlstat_args * uap)2562 freebsd11_nlstat(struct thread *td, struct freebsd11_nlstat_args *uap)
2563 {
2564 	struct stat sb;
2565 	struct nstat nsb;
2566 	int error;
2567 
2568 	error = kern_statat(td, AT_SYMLINK_NOFOLLOW, AT_FDCWD, uap->path,
2569 	    UIO_USERSPACE, &sb);
2570 	if (error != 0)
2571 		return (error);
2572 	error = freebsd11_cvtnstat(&sb, &nsb);
2573 	if (error == 0)
2574 		error = copyout(&nsb, uap->ub, sizeof (nsb));
2575 	return (error);
2576 }
2577 #endif /* COMPAT_FREEBSD11 */
2578 
2579 /*
2580  * Get configurable pathname variables.
2581  */
2582 #ifndef _SYS_SYSPROTO_H_
2583 struct pathconf_args {
2584 	char	*path;
2585 	int	name;
2586 };
2587 #endif
2588 int
sys_pathconf(struct thread * td,struct pathconf_args * uap)2589 sys_pathconf(struct thread *td, struct pathconf_args *uap)
2590 {
2591 	long value;
2592 	int error;
2593 
2594 	error = kern_pathconf(td, uap->path, UIO_USERSPACE, uap->name, FOLLOW,
2595 	    &value);
2596 	if (error == 0)
2597 		td->td_retval[0] = value;
2598 	return (error);
2599 }
2600 
2601 #ifndef _SYS_SYSPROTO_H_
2602 struct lpathconf_args {
2603 	char	*path;
2604 	int	name;
2605 };
2606 #endif
2607 int
sys_lpathconf(struct thread * td,struct lpathconf_args * uap)2608 sys_lpathconf(struct thread *td, struct lpathconf_args *uap)
2609 {
2610 	long value;
2611 	int error;
2612 
2613 	error = kern_pathconf(td, uap->path, UIO_USERSPACE, uap->name,
2614 	    NOFOLLOW, &value);
2615 	if (error == 0)
2616 		td->td_retval[0] = value;
2617 	return (error);
2618 }
2619 
2620 int
kern_pathconf(struct thread * td,const char * path,enum uio_seg pathseg,int name,u_long flags,long * valuep)2621 kern_pathconf(struct thread *td, const char *path, enum uio_seg pathseg,
2622     int name, u_long flags, long *valuep)
2623 {
2624 	struct nameidata nd;
2625 	int error;
2626 
2627 	NDINIT(&nd, LOOKUP, LOCKSHARED | LOCKLEAF | AUDITVNODE1 | flags,
2628 	       pathseg, path);
2629 	if ((error = namei(&nd)) != 0)
2630 		return (error);
2631 	NDFREE_PNBUF(&nd);
2632 
2633 	error = VOP_PATHCONF(nd.ni_vp, name, valuep);
2634 	vput(nd.ni_vp);
2635 	return (error);
2636 }
2637 
2638 /*
2639  * Return target name of a symbolic link.
2640  */
2641 #ifndef _SYS_SYSPROTO_H_
2642 struct readlink_args {
2643 	char	*path;
2644 	char	*buf;
2645 	size_t	count;
2646 };
2647 #endif
2648 int
sys_readlink(struct thread * td,struct readlink_args * uap)2649 sys_readlink(struct thread *td, struct readlink_args *uap)
2650 {
2651 
2652 	return (kern_readlinkat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
2653 	    uap->buf, UIO_USERSPACE, uap->count));
2654 }
2655 #ifndef _SYS_SYSPROTO_H_
2656 struct readlinkat_args {
2657 	int	fd;
2658 	char	*path;
2659 	char	*buf;
2660 	size_t	bufsize;
2661 };
2662 #endif
2663 int
sys_readlinkat(struct thread * td,struct readlinkat_args * uap)2664 sys_readlinkat(struct thread *td, struct readlinkat_args *uap)
2665 {
2666 
2667 	return (kern_readlinkat(td, uap->fd, uap->path, UIO_USERSPACE,
2668 	    uap->buf, UIO_USERSPACE, uap->bufsize));
2669 }
2670 
2671 int
kern_readlinkat(struct thread * td,int fd,const char * path,enum uio_seg pathseg,char * buf,enum uio_seg bufseg,size_t count)2672 kern_readlinkat(struct thread *td, int fd, const char *path,
2673     enum uio_seg pathseg, char *buf, enum uio_seg bufseg, size_t count)
2674 {
2675 	struct vnode *vp;
2676 	struct nameidata nd;
2677 	int error;
2678 
2679 	if (count > IOSIZE_MAX)
2680 		return (EINVAL);
2681 
2682 	NDINIT_AT(&nd, LOOKUP, NOFOLLOW | LOCKSHARED | LOCKLEAF | AUDITVNODE1 |
2683 	    EMPTYPATH, pathseg, path, fd);
2684 
2685 	if ((error = namei(&nd)) != 0)
2686 		return (error);
2687 	NDFREE_PNBUF(&nd);
2688 	vp = nd.ni_vp;
2689 
2690 	error = kern_readlink_vp(vp, buf, bufseg, count, td);
2691 	vput(vp);
2692 
2693 	return (error);
2694 }
2695 
2696 /*
2697  * Helper function to readlink from a vnode
2698  */
2699 static int
kern_readlink_vp(struct vnode * vp,char * buf,enum uio_seg bufseg,size_t count,struct thread * td)2700 kern_readlink_vp(struct vnode *vp, char *buf, enum uio_seg bufseg, size_t count,
2701     struct thread *td)
2702 {
2703 	struct iovec aiov;
2704 	struct uio auio;
2705 	int error;
2706 
2707 	ASSERT_VOP_LOCKED(vp, "kern_readlink_vp(): vp not locked");
2708 #ifdef MAC
2709 	error = mac_vnode_check_readlink(td->td_ucred, vp);
2710 	if (error != 0)
2711 		return (error);
2712 #endif
2713 	if (vp->v_type != VLNK && (vp->v_vflag & VV_READLINK) == 0)
2714 		return (EINVAL);
2715 
2716 	aiov.iov_base = buf;
2717 	aiov.iov_len = count;
2718 	auio.uio_iov = &aiov;
2719 	auio.uio_iovcnt = 1;
2720 	auio.uio_offset = 0;
2721 	auio.uio_rw = UIO_READ;
2722 	auio.uio_segflg = bufseg;
2723 	auio.uio_td = td;
2724 	auio.uio_resid = count;
2725 	error = VOP_READLINK(vp, &auio, td->td_ucred);
2726 	td->td_retval[0] = count - auio.uio_resid;
2727 	return (error);
2728 }
2729 
2730 /*
2731  * Common implementation code for chflags() and fchflags().
2732  */
2733 static int
setfflags(struct thread * td,struct vnode * vp,u_long flags)2734 setfflags(struct thread *td, struct vnode *vp, u_long flags)
2735 {
2736 	struct mount *mp;
2737 	struct vattr vattr;
2738 	int error;
2739 
2740 	/* We can't support the value matching VNOVAL. */
2741 	if (flags == VNOVAL)
2742 		return (EOPNOTSUPP);
2743 
2744 	/*
2745 	 * Prevent non-root users from setting flags on devices.  When
2746 	 * a device is reused, users can retain ownership of the device
2747 	 * if they are allowed to set flags and programs assume that
2748 	 * chown can't fail when done as root.
2749 	 */
2750 	if (vp->v_type == VCHR || vp->v_type == VBLK) {
2751 		error = priv_check(td, PRIV_VFS_CHFLAGS_DEV);
2752 		if (error != 0)
2753 			return (error);
2754 	}
2755 
2756 	if ((error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH)) != 0)
2757 		return (error);
2758 	VATTR_NULL(&vattr);
2759 	vattr.va_flags = flags;
2760 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2761 #ifdef MAC
2762 	error = mac_vnode_check_setflags(td->td_ucred, vp, vattr.va_flags);
2763 	if (error == 0)
2764 #endif
2765 		error = VOP_SETATTR(vp, &vattr, td->td_ucred);
2766 	VOP_UNLOCK(vp);
2767 	vn_finished_write(mp);
2768 	return (error);
2769 }
2770 
2771 /*
2772  * Change flags of a file given a path name.
2773  */
2774 #ifndef _SYS_SYSPROTO_H_
2775 struct chflags_args {
2776 	const char *path;
2777 	u_long	flags;
2778 };
2779 #endif
2780 int
sys_chflags(struct thread * td,struct chflags_args * uap)2781 sys_chflags(struct thread *td, struct chflags_args *uap)
2782 {
2783 
2784 	return (kern_chflagsat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
2785 	    uap->flags, 0));
2786 }
2787 
2788 #ifndef _SYS_SYSPROTO_H_
2789 struct chflagsat_args {
2790 	int	fd;
2791 	const char *path;
2792 	u_long	flags;
2793 	int	atflag;
2794 }
2795 #endif
2796 int
sys_chflagsat(struct thread * td,struct chflagsat_args * uap)2797 sys_chflagsat(struct thread *td, struct chflagsat_args *uap)
2798 {
2799 
2800 	return (kern_chflagsat(td, uap->fd, uap->path, UIO_USERSPACE,
2801 	    uap->flags, uap->atflag));
2802 }
2803 
2804 /*
2805  * Same as chflags() but doesn't follow symlinks.
2806  */
2807 #ifndef _SYS_SYSPROTO_H_
2808 struct lchflags_args {
2809 	const char *path;
2810 	u_long flags;
2811 };
2812 #endif
2813 int
sys_lchflags(struct thread * td,struct lchflags_args * uap)2814 sys_lchflags(struct thread *td, struct lchflags_args *uap)
2815 {
2816 
2817 	return (kern_chflagsat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
2818 	    uap->flags, AT_SYMLINK_NOFOLLOW));
2819 }
2820 
2821 static int
kern_chflagsat(struct thread * td,int fd,const char * path,enum uio_seg pathseg,u_long flags,int atflag)2822 kern_chflagsat(struct thread *td, int fd, const char *path,
2823     enum uio_seg pathseg, u_long flags, int atflag)
2824 {
2825 	struct nameidata nd;
2826 	int error;
2827 
2828 	if ((atflag & ~(AT_SYMLINK_NOFOLLOW | AT_RESOLVE_BENEATH |
2829 	    AT_EMPTY_PATH)) != 0)
2830 		return (EINVAL);
2831 
2832 	AUDIT_ARG_FFLAGS(flags);
2833 	NDINIT_ATRIGHTS(&nd, LOOKUP, at2cnpflags(atflag, AT_SYMLINK_NOFOLLOW |
2834 	    AT_RESOLVE_BENEATH | AT_EMPTY_PATH) | AUDITVNODE1, pathseg, path,
2835 	    fd, &cap_fchflags_rights);
2836 	if ((error = namei(&nd)) != 0)
2837 		return (error);
2838 	NDFREE_PNBUF(&nd);
2839 	error = setfflags(td, nd.ni_vp, flags);
2840 	vrele(nd.ni_vp);
2841 	return (error);
2842 }
2843 
2844 /*
2845  * Change flags of a file given a file descriptor.
2846  */
2847 #ifndef _SYS_SYSPROTO_H_
2848 struct fchflags_args {
2849 	int	fd;
2850 	u_long	flags;
2851 };
2852 #endif
2853 int
sys_fchflags(struct thread * td,struct fchflags_args * uap)2854 sys_fchflags(struct thread *td, struct fchflags_args *uap)
2855 {
2856 	struct file *fp;
2857 	int error;
2858 
2859 	AUDIT_ARG_FD(uap->fd);
2860 	AUDIT_ARG_FFLAGS(uap->flags);
2861 	error = getvnode(td, uap->fd, &cap_fchflags_rights,
2862 	    &fp);
2863 	if (error != 0)
2864 		return (error);
2865 #ifdef AUDIT
2866 	if (AUDITING_TD(td)) {
2867 		vn_lock(fp->f_vnode, LK_SHARED | LK_RETRY);
2868 		AUDIT_ARG_VNODE1(fp->f_vnode);
2869 		VOP_UNLOCK(fp->f_vnode);
2870 	}
2871 #endif
2872 	error = setfflags(td, fp->f_vnode, uap->flags);
2873 	fdrop(fp, td);
2874 	return (error);
2875 }
2876 
2877 /*
2878  * Common implementation code for chmod(), lchmod() and fchmod().
2879  */
2880 int
setfmode(struct thread * td,struct ucred * cred,struct vnode * vp,int mode)2881 setfmode(struct thread *td, struct ucred *cred, struct vnode *vp, int mode)
2882 {
2883 	struct mount *mp;
2884 	struct vattr vattr;
2885 	int error;
2886 
2887 	if ((error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH)) != 0)
2888 		return (error);
2889 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2890 	VATTR_NULL(&vattr);
2891 	vattr.va_mode = mode & ALLPERMS;
2892 #ifdef MAC
2893 	error = mac_vnode_check_setmode(cred, vp, vattr.va_mode);
2894 	if (error == 0)
2895 #endif
2896 		error = VOP_SETATTR(vp, &vattr, cred);
2897 	VOP_UNLOCK(vp);
2898 	vn_finished_write(mp);
2899 	return (error);
2900 }
2901 
2902 /*
2903  * Change mode of a file given path name.
2904  */
2905 #ifndef _SYS_SYSPROTO_H_
2906 struct chmod_args {
2907 	char	*path;
2908 	int	mode;
2909 };
2910 #endif
2911 int
sys_chmod(struct thread * td,struct chmod_args * uap)2912 sys_chmod(struct thread *td, struct chmod_args *uap)
2913 {
2914 
2915 	return (kern_fchmodat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
2916 	    uap->mode, 0));
2917 }
2918 
2919 #ifndef _SYS_SYSPROTO_H_
2920 struct fchmodat_args {
2921 	int	dirfd;
2922 	char	*path;
2923 	mode_t	mode;
2924 	int	flag;
2925 }
2926 #endif
2927 int
sys_fchmodat(struct thread * td,struct fchmodat_args * uap)2928 sys_fchmodat(struct thread *td, struct fchmodat_args *uap)
2929 {
2930 
2931 	return (kern_fchmodat(td, uap->fd, uap->path, UIO_USERSPACE,
2932 	    uap->mode, uap->flag));
2933 }
2934 
2935 /*
2936  * Change mode of a file given path name (don't follow links.)
2937  */
2938 #ifndef _SYS_SYSPROTO_H_
2939 struct lchmod_args {
2940 	char	*path;
2941 	int	mode;
2942 };
2943 #endif
2944 int
sys_lchmod(struct thread * td,struct lchmod_args * uap)2945 sys_lchmod(struct thread *td, struct lchmod_args *uap)
2946 {
2947 
2948 	return (kern_fchmodat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
2949 	    uap->mode, AT_SYMLINK_NOFOLLOW));
2950 }
2951 
2952 int
kern_fchmodat(struct thread * td,int fd,const char * path,enum uio_seg pathseg,mode_t mode,int flag)2953 kern_fchmodat(struct thread *td, int fd, const char *path,
2954     enum uio_seg pathseg, mode_t mode, int flag)
2955 {
2956 	struct nameidata nd;
2957 	int error;
2958 
2959 	if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_RESOLVE_BENEATH |
2960 	    AT_EMPTY_PATH)) != 0)
2961 		return (EINVAL);
2962 
2963 	AUDIT_ARG_MODE(mode);
2964 	NDINIT_ATRIGHTS(&nd, LOOKUP, at2cnpflags(flag, AT_SYMLINK_NOFOLLOW |
2965 	    AT_RESOLVE_BENEATH | AT_EMPTY_PATH) | AUDITVNODE1, pathseg, path,
2966 	    fd, &cap_fchmod_rights);
2967 	if ((error = namei(&nd)) != 0)
2968 		return (error);
2969 	NDFREE_PNBUF(&nd);
2970 	error = setfmode(td, td->td_ucred, nd.ni_vp, mode);
2971 	vrele(nd.ni_vp);
2972 	return (error);
2973 }
2974 
2975 /*
2976  * Change mode of a file given a file descriptor.
2977  */
2978 #ifndef _SYS_SYSPROTO_H_
2979 struct fchmod_args {
2980 	int	fd;
2981 	int	mode;
2982 };
2983 #endif
2984 int
sys_fchmod(struct thread * td,struct fchmod_args * uap)2985 sys_fchmod(struct thread *td, struct fchmod_args *uap)
2986 {
2987 	struct file *fp;
2988 	int error;
2989 
2990 	AUDIT_ARG_FD(uap->fd);
2991 	AUDIT_ARG_MODE(uap->mode);
2992 
2993 	error = fget(td, uap->fd, &cap_fchmod_rights, &fp);
2994 	if (error != 0)
2995 		return (error);
2996 	error = fo_chmod(fp, uap->mode, td->td_ucred, td);
2997 	fdrop(fp, td);
2998 	return (error);
2999 }
3000 
3001 /*
3002  * Common implementation for chown(), lchown(), and fchown()
3003  */
3004 int
setfown(struct thread * td,struct ucred * cred,struct vnode * vp,uid_t uid,gid_t gid)3005 setfown(struct thread *td, struct ucred *cred, struct vnode *vp, uid_t uid,
3006     gid_t gid)
3007 {
3008 	struct mount *mp;
3009 	struct vattr vattr;
3010 	int error;
3011 
3012 	if ((error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH)) != 0)
3013 		return (error);
3014 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3015 	VATTR_NULL(&vattr);
3016 	vattr.va_uid = uid;
3017 	vattr.va_gid = gid;
3018 #ifdef MAC
3019 	error = mac_vnode_check_setowner(cred, vp, vattr.va_uid,
3020 	    vattr.va_gid);
3021 	if (error == 0)
3022 #endif
3023 		error = VOP_SETATTR(vp, &vattr, cred);
3024 	VOP_UNLOCK(vp);
3025 	vn_finished_write(mp);
3026 	return (error);
3027 }
3028 
3029 /*
3030  * Set ownership given a path name.
3031  */
3032 #ifndef _SYS_SYSPROTO_H_
3033 struct chown_args {
3034 	char	*path;
3035 	int	uid;
3036 	int	gid;
3037 };
3038 #endif
3039 int
sys_chown(struct thread * td,struct chown_args * uap)3040 sys_chown(struct thread *td, struct chown_args *uap)
3041 {
3042 
3043 	return (kern_fchownat(td, AT_FDCWD, uap->path, UIO_USERSPACE, uap->uid,
3044 	    uap->gid, 0));
3045 }
3046 
3047 #ifndef _SYS_SYSPROTO_H_
3048 struct fchownat_args {
3049 	int fd;
3050 	const char * path;
3051 	uid_t uid;
3052 	gid_t gid;
3053 	int flag;
3054 };
3055 #endif
3056 int
sys_fchownat(struct thread * td,struct fchownat_args * uap)3057 sys_fchownat(struct thread *td, struct fchownat_args *uap)
3058 {
3059 
3060 	return (kern_fchownat(td, uap->fd, uap->path, UIO_USERSPACE, uap->uid,
3061 	    uap->gid, uap->flag));
3062 }
3063 
3064 int
kern_fchownat(struct thread * td,int fd,const char * path,enum uio_seg pathseg,int uid,int gid,int flag)3065 kern_fchownat(struct thread *td, int fd, const char *path,
3066     enum uio_seg pathseg, int uid, int gid, int flag)
3067 {
3068 	struct nameidata nd;
3069 	int error;
3070 
3071 	if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_RESOLVE_BENEATH |
3072 	    AT_EMPTY_PATH)) != 0)
3073 		return (EINVAL);
3074 
3075 	AUDIT_ARG_OWNER(uid, gid);
3076 	NDINIT_ATRIGHTS(&nd, LOOKUP, at2cnpflags(flag, AT_SYMLINK_NOFOLLOW |
3077 	    AT_RESOLVE_BENEATH | AT_EMPTY_PATH) | AUDITVNODE1, pathseg, path,
3078 	    fd, &cap_fchown_rights);
3079 
3080 	if ((error = namei(&nd)) != 0)
3081 		return (error);
3082 	NDFREE_PNBUF(&nd);
3083 	error = setfown(td, td->td_ucred, nd.ni_vp, uid, gid);
3084 	vrele(nd.ni_vp);
3085 	return (error);
3086 }
3087 
3088 /*
3089  * Set ownership given a path name, do not cross symlinks.
3090  */
3091 #ifndef _SYS_SYSPROTO_H_
3092 struct lchown_args {
3093 	char	*path;
3094 	int	uid;
3095 	int	gid;
3096 };
3097 #endif
3098 int
sys_lchown(struct thread * td,struct lchown_args * uap)3099 sys_lchown(struct thread *td, struct lchown_args *uap)
3100 {
3101 
3102 	return (kern_fchownat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
3103 	    uap->uid, uap->gid, AT_SYMLINK_NOFOLLOW));
3104 }
3105 
3106 /*
3107  * Set ownership given a file descriptor.
3108  */
3109 #ifndef _SYS_SYSPROTO_H_
3110 struct fchown_args {
3111 	int	fd;
3112 	int	uid;
3113 	int	gid;
3114 };
3115 #endif
3116 int
sys_fchown(struct thread * td,struct fchown_args * uap)3117 sys_fchown(struct thread *td, struct fchown_args *uap)
3118 {
3119 	struct file *fp;
3120 	int error;
3121 
3122 	AUDIT_ARG_FD(uap->fd);
3123 	AUDIT_ARG_OWNER(uap->uid, uap->gid);
3124 	error = fget(td, uap->fd, &cap_fchown_rights, &fp);
3125 	if (error != 0)
3126 		return (error);
3127 	error = fo_chown(fp, uap->uid, uap->gid, td->td_ucred, td);
3128 	fdrop(fp, td);
3129 	return (error);
3130 }
3131 
3132 /*
3133  * Common implementation code for utimes(), lutimes(), and futimes().
3134  */
3135 static int
getutimes(const struct timeval * usrtvp,enum uio_seg tvpseg,struct timespec * tsp)3136 getutimes(const struct timeval *usrtvp, enum uio_seg tvpseg,
3137     struct timespec *tsp)
3138 {
3139 	struct timeval tv[2];
3140 	const struct timeval *tvp;
3141 	int error;
3142 
3143 	if (usrtvp == NULL) {
3144 		vfs_timestamp(&tsp[0]);
3145 		tsp[1] = tsp[0];
3146 	} else {
3147 		if (tvpseg == UIO_SYSSPACE) {
3148 			tvp = usrtvp;
3149 		} else {
3150 			if ((error = copyin(usrtvp, tv, sizeof(tv))) != 0)
3151 				return (error);
3152 			tvp = tv;
3153 		}
3154 
3155 		if (tvp[0].tv_usec < 0 || tvp[0].tv_usec >= 1000000 ||
3156 		    tvp[1].tv_usec < 0 || tvp[1].tv_usec >= 1000000)
3157 			return (EINVAL);
3158 		TIMEVAL_TO_TIMESPEC(&tvp[0], &tsp[0]);
3159 		TIMEVAL_TO_TIMESPEC(&tvp[1], &tsp[1]);
3160 	}
3161 	return (0);
3162 }
3163 
3164 /*
3165  * Common implementation code for futimens(), utimensat().
3166  */
3167 #define	UTIMENS_NULL	0x1
3168 #define	UTIMENS_EXIT	0x2
3169 static int
getutimens(const struct timespec * usrtsp,enum uio_seg tspseg,struct timespec * tsp,int * retflags)3170 getutimens(const struct timespec *usrtsp, enum uio_seg tspseg,
3171     struct timespec *tsp, int *retflags)
3172 {
3173 	struct timespec tsnow;
3174 	int error;
3175 
3176 	vfs_timestamp(&tsnow);
3177 	*retflags = 0;
3178 	if (usrtsp == NULL) {
3179 		tsp[0] = tsnow;
3180 		tsp[1] = tsnow;
3181 		*retflags |= UTIMENS_NULL;
3182 		return (0);
3183 	}
3184 	if (tspseg == UIO_SYSSPACE) {
3185 		tsp[0] = usrtsp[0];
3186 		tsp[1] = usrtsp[1];
3187 	} else if ((error = copyin(usrtsp, tsp, sizeof(*tsp) * 2)) != 0)
3188 		return (error);
3189 	if (tsp[0].tv_nsec == UTIME_OMIT && tsp[1].tv_nsec == UTIME_OMIT)
3190 		*retflags |= UTIMENS_EXIT;
3191 	if (tsp[0].tv_nsec == UTIME_NOW && tsp[1].tv_nsec == UTIME_NOW)
3192 		*retflags |= UTIMENS_NULL;
3193 	if (tsp[0].tv_nsec == UTIME_OMIT)
3194 		tsp[0].tv_sec = VNOVAL;
3195 	else if (tsp[0].tv_nsec == UTIME_NOW)
3196 		tsp[0] = tsnow;
3197 	else if (tsp[0].tv_nsec < 0 || tsp[0].tv_nsec >= 1000000000L)
3198 		return (EINVAL);
3199 	if (tsp[1].tv_nsec == UTIME_OMIT)
3200 		tsp[1].tv_sec = VNOVAL;
3201 	else if (tsp[1].tv_nsec == UTIME_NOW)
3202 		tsp[1] = tsnow;
3203 	else if (tsp[1].tv_nsec < 0 || tsp[1].tv_nsec >= 1000000000L)
3204 		return (EINVAL);
3205 
3206 	return (0);
3207 }
3208 
3209 /*
3210  * Common implementation code for utimes(), lutimes(), futimes(), futimens(),
3211  * and utimensat().
3212  */
3213 static int
setutimes(struct thread * td,struct vnode * vp,const struct timespec * ts,int numtimes,int nullflag)3214 setutimes(struct thread *td, struct vnode *vp, const struct timespec *ts,
3215     int numtimes, int nullflag)
3216 {
3217 	struct mount *mp;
3218 	struct vattr vattr;
3219 	int error;
3220 	bool setbirthtime;
3221 
3222 	setbirthtime = false;
3223 	vattr.va_birthtime.tv_sec = VNOVAL;
3224 	vattr.va_birthtime.tv_nsec = 0;
3225 
3226 	if ((error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH)) != 0)
3227 		return (error);
3228 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3229 	if (numtimes < 3 && VOP_GETATTR(vp, &vattr, td->td_ucred) == 0 &&
3230 	    timespeccmp(&ts[1], &vattr.va_birthtime, < ))
3231 		setbirthtime = true;
3232 	VATTR_NULL(&vattr);
3233 	vattr.va_atime = ts[0];
3234 	vattr.va_mtime = ts[1];
3235 	if (setbirthtime)
3236 		vattr.va_birthtime = ts[1];
3237 	if (numtimes > 2)
3238 		vattr.va_birthtime = ts[2];
3239 	if (nullflag)
3240 		vattr.va_vaflags |= VA_UTIMES_NULL;
3241 #ifdef MAC
3242 	error = mac_vnode_check_setutimes(td->td_ucred, vp, vattr.va_atime,
3243 	    vattr.va_mtime);
3244 #endif
3245 	if (error == 0)
3246 		error = VOP_SETATTR(vp, &vattr, td->td_ucred);
3247 	VOP_UNLOCK(vp);
3248 	vn_finished_write(mp);
3249 	return (error);
3250 }
3251 
3252 /*
3253  * Set the access and modification times of a file.
3254  */
3255 #ifndef _SYS_SYSPROTO_H_
3256 struct utimes_args {
3257 	char	*path;
3258 	struct	timeval *tptr;
3259 };
3260 #endif
3261 int
sys_utimes(struct thread * td,struct utimes_args * uap)3262 sys_utimes(struct thread *td, struct utimes_args *uap)
3263 {
3264 
3265 	return (kern_utimesat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
3266 	    uap->tptr, UIO_USERSPACE));
3267 }
3268 
3269 #ifndef _SYS_SYSPROTO_H_
3270 struct futimesat_args {
3271 	int fd;
3272 	const char * path;
3273 	const struct timeval * times;
3274 };
3275 #endif
3276 int
sys_futimesat(struct thread * td,struct futimesat_args * uap)3277 sys_futimesat(struct thread *td, struct futimesat_args *uap)
3278 {
3279 
3280 	return (kern_utimesat(td, uap->fd, uap->path, UIO_USERSPACE,
3281 	    uap->times, UIO_USERSPACE));
3282 }
3283 
3284 int
kern_utimesat(struct thread * td,int fd,const char * path,enum uio_seg pathseg,const struct timeval * tptr,enum uio_seg tptrseg)3285 kern_utimesat(struct thread *td, int fd, const char *path,
3286     enum uio_seg pathseg, const struct timeval *tptr, enum uio_seg tptrseg)
3287 {
3288 	struct nameidata nd;
3289 	struct timespec ts[2];
3290 	int error;
3291 
3292 	if ((error = getutimes(tptr, tptrseg, ts)) != 0)
3293 		return (error);
3294 	NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | AUDITVNODE1, pathseg, path, fd,
3295 	    &cap_futimes_rights);
3296 
3297 	if ((error = namei(&nd)) != 0)
3298 		return (error);
3299 	NDFREE_PNBUF(&nd);
3300 	error = setutimes(td, nd.ni_vp, ts, 2, tptr == NULL);
3301 	vrele(nd.ni_vp);
3302 	return (error);
3303 }
3304 
3305 /*
3306  * Set the access and modification times of a file.
3307  */
3308 #ifndef _SYS_SYSPROTO_H_
3309 struct lutimes_args {
3310 	char	*path;
3311 	struct	timeval *tptr;
3312 };
3313 #endif
3314 int
sys_lutimes(struct thread * td,struct lutimes_args * uap)3315 sys_lutimes(struct thread *td, struct lutimes_args *uap)
3316 {
3317 
3318 	return (kern_lutimes(td, uap->path, UIO_USERSPACE, uap->tptr,
3319 	    UIO_USERSPACE));
3320 }
3321 
3322 int
kern_lutimes(struct thread * td,const char * path,enum uio_seg pathseg,const struct timeval * tptr,enum uio_seg tptrseg)3323 kern_lutimes(struct thread *td, const char *path, enum uio_seg pathseg,
3324     const struct timeval *tptr, enum uio_seg tptrseg)
3325 {
3326 	struct timespec ts[2];
3327 	struct nameidata nd;
3328 	int error;
3329 
3330 	if ((error = getutimes(tptr, tptrseg, ts)) != 0)
3331 		return (error);
3332 	NDINIT(&nd, LOOKUP, NOFOLLOW | AUDITVNODE1, pathseg, path);
3333 	if ((error = namei(&nd)) != 0)
3334 		return (error);
3335 	NDFREE_PNBUF(&nd);
3336 	error = setutimes(td, nd.ni_vp, ts, 2, tptr == NULL);
3337 	vrele(nd.ni_vp);
3338 	return (error);
3339 }
3340 
3341 /*
3342  * Set the access and modification times of a file.
3343  */
3344 #ifndef _SYS_SYSPROTO_H_
3345 struct futimes_args {
3346 	int	fd;
3347 	struct	timeval *tptr;
3348 };
3349 #endif
3350 int
sys_futimes(struct thread * td,struct futimes_args * uap)3351 sys_futimes(struct thread *td, struct futimes_args *uap)
3352 {
3353 
3354 	return (kern_futimes(td, uap->fd, uap->tptr, UIO_USERSPACE));
3355 }
3356 
3357 int
kern_futimes(struct thread * td,int fd,const struct timeval * tptr,enum uio_seg tptrseg)3358 kern_futimes(struct thread *td, int fd, const struct timeval *tptr,
3359     enum uio_seg tptrseg)
3360 {
3361 	struct timespec ts[2];
3362 	struct file *fp;
3363 	int error;
3364 
3365 	AUDIT_ARG_FD(fd);
3366 	error = getutimes(tptr, tptrseg, ts);
3367 	if (error != 0)
3368 		return (error);
3369 	error = getvnode(td, fd, &cap_futimes_rights, &fp);
3370 	if (error != 0)
3371 		return (error);
3372 #ifdef AUDIT
3373 	if (AUDITING_TD(td)) {
3374 		vn_lock(fp->f_vnode, LK_SHARED | LK_RETRY);
3375 		AUDIT_ARG_VNODE1(fp->f_vnode);
3376 		VOP_UNLOCK(fp->f_vnode);
3377 	}
3378 #endif
3379 	error = setutimes(td, fp->f_vnode, ts, 2, tptr == NULL);
3380 	fdrop(fp, td);
3381 	return (error);
3382 }
3383 
3384 int
sys_futimens(struct thread * td,struct futimens_args * uap)3385 sys_futimens(struct thread *td, struct futimens_args *uap)
3386 {
3387 
3388 	return (kern_futimens(td, uap->fd, uap->times, UIO_USERSPACE));
3389 }
3390 
3391 int
kern_futimens(struct thread * td,int fd,const struct timespec * tptr,enum uio_seg tptrseg)3392 kern_futimens(struct thread *td, int fd, const struct timespec *tptr,
3393     enum uio_seg tptrseg)
3394 {
3395 	struct timespec ts[2];
3396 	struct file *fp;
3397 	int error, flags;
3398 
3399 	AUDIT_ARG_FD(fd);
3400 	error = getutimens(tptr, tptrseg, ts, &flags);
3401 	if (error != 0)
3402 		return (error);
3403 	if (flags & UTIMENS_EXIT)
3404 		return (0);
3405 	error = getvnode(td, fd, &cap_futimes_rights, &fp);
3406 	if (error != 0)
3407 		return (error);
3408 #ifdef AUDIT
3409 	if (AUDITING_TD(td)) {
3410 		vn_lock(fp->f_vnode, LK_SHARED | LK_RETRY);
3411 		AUDIT_ARG_VNODE1(fp->f_vnode);
3412 		VOP_UNLOCK(fp->f_vnode);
3413 	}
3414 #endif
3415 	error = setutimes(td, fp->f_vnode, ts, 2, flags & UTIMENS_NULL);
3416 	fdrop(fp, td);
3417 	return (error);
3418 }
3419 
3420 int
sys_utimensat(struct thread * td,struct utimensat_args * uap)3421 sys_utimensat(struct thread *td, struct utimensat_args *uap)
3422 {
3423 
3424 	return (kern_utimensat(td, uap->fd, uap->path, UIO_USERSPACE,
3425 	    uap->times, UIO_USERSPACE, uap->flag));
3426 }
3427 
3428 int
kern_utimensat(struct thread * td,int fd,const char * path,enum uio_seg pathseg,const struct timespec * tptr,enum uio_seg tptrseg,int flag)3429 kern_utimensat(struct thread *td, int fd, const char *path,
3430     enum uio_seg pathseg, const struct timespec *tptr, enum uio_seg tptrseg,
3431     int flag)
3432 {
3433 	struct nameidata nd;
3434 	struct timespec ts[2];
3435 	int error, flags;
3436 
3437 	if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_RESOLVE_BENEATH |
3438 	    AT_EMPTY_PATH)) != 0)
3439 		return (EINVAL);
3440 
3441 	if ((error = getutimens(tptr, tptrseg, ts, &flags)) != 0)
3442 		return (error);
3443 	NDINIT_ATRIGHTS(&nd, LOOKUP, at2cnpflags(flag, AT_SYMLINK_NOFOLLOW |
3444 	    AT_RESOLVE_BENEATH | AT_EMPTY_PATH) | AUDITVNODE1,
3445 	    pathseg, path, fd, &cap_futimes_rights);
3446 	if ((error = namei(&nd)) != 0)
3447 		return (error);
3448 	/*
3449 	 * We are allowed to call namei() regardless of 2xUTIME_OMIT.
3450 	 * POSIX states:
3451 	 * "If both tv_nsec fields are UTIME_OMIT... EACCESS may be detected."
3452 	 * "Search permission is denied by a component of the path prefix."
3453 	 */
3454 	NDFREE_PNBUF(&nd);
3455 	if ((flags & UTIMENS_EXIT) == 0)
3456 		error = setutimes(td, nd.ni_vp, ts, 2, flags & UTIMENS_NULL);
3457 	vrele(nd.ni_vp);
3458 	return (error);
3459 }
3460 
3461 /*
3462  * Truncate a file given its path name.
3463  */
3464 #ifndef _SYS_SYSPROTO_H_
3465 struct truncate_args {
3466 	char	*path;
3467 	int	pad;
3468 	off_t	length;
3469 };
3470 #endif
3471 int
sys_truncate(struct thread * td,struct truncate_args * uap)3472 sys_truncate(struct thread *td, struct truncate_args *uap)
3473 {
3474 
3475 	return (kern_truncate(td, uap->path, UIO_USERSPACE, uap->length));
3476 }
3477 
3478 int
kern_truncate(struct thread * td,const char * path,enum uio_seg pathseg,off_t length)3479 kern_truncate(struct thread *td, const char *path, enum uio_seg pathseg,
3480     off_t length)
3481 {
3482 	struct mount *mp;
3483 	struct vnode *vp;
3484 	void *rl_cookie;
3485 	struct nameidata nd;
3486 	int error;
3487 
3488 	if (length < 0)
3489 		return (EINVAL);
3490 	NDPREINIT(&nd);
3491 retry:
3492 	NDINIT(&nd, LOOKUP, FOLLOW | AUDITVNODE1, pathseg, path);
3493 	if ((error = namei(&nd)) != 0)
3494 		return (error);
3495 	vp = nd.ni_vp;
3496 	NDFREE_PNBUF(&nd);
3497 	rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
3498 	if ((error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH)) != 0) {
3499 		vn_rangelock_unlock(vp, rl_cookie);
3500 		vrele(vp);
3501 		return (error);
3502 	}
3503 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3504 	if (vp->v_type == VDIR) {
3505 		error = EISDIR;
3506 		goto out;
3507 	}
3508 #ifdef MAC
3509 	error = mac_vnode_check_write(td->td_ucred, NOCRED, vp);
3510 	if (error != 0)
3511 		goto out;
3512 #endif
3513 	error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td);
3514 	if (error != 0)
3515 		goto out;
3516 
3517 	error = vn_truncate_locked(vp, length, false, td->td_ucred);
3518 out:
3519 	VOP_UNLOCK(vp);
3520 	vn_finished_write(mp);
3521 	vn_rangelock_unlock(vp, rl_cookie);
3522 	vrele(vp);
3523 	if (error == ERELOOKUP)
3524 		goto retry;
3525 	return (error);
3526 }
3527 
3528 #if defined(COMPAT_43)
3529 /*
3530  * Truncate a file given its path name.
3531  */
3532 #ifndef _SYS_SYSPROTO_H_
3533 struct otruncate_args {
3534 	char	*path;
3535 	long	length;
3536 };
3537 #endif
3538 int
otruncate(struct thread * td,struct otruncate_args * uap)3539 otruncate(struct thread *td, struct otruncate_args *uap)
3540 {
3541 
3542 	return (kern_truncate(td, uap->path, UIO_USERSPACE, uap->length));
3543 }
3544 #endif /* COMPAT_43 */
3545 
3546 #if defined(COMPAT_FREEBSD6)
3547 /* Versions with the pad argument */
3548 int
freebsd6_truncate(struct thread * td,struct freebsd6_truncate_args * uap)3549 freebsd6_truncate(struct thread *td, struct freebsd6_truncate_args *uap)
3550 {
3551 
3552 	return (kern_truncate(td, uap->path, UIO_USERSPACE, uap->length));
3553 }
3554 
3555 int
freebsd6_ftruncate(struct thread * td,struct freebsd6_ftruncate_args * uap)3556 freebsd6_ftruncate(struct thread *td, struct freebsd6_ftruncate_args *uap)
3557 {
3558 
3559 	return (kern_ftruncate(td, uap->fd, uap->length));
3560 }
3561 #endif
3562 
3563 int
kern_fsync(struct thread * td,int fd,bool fullsync)3564 kern_fsync(struct thread *td, int fd, bool fullsync)
3565 {
3566 	struct vnode *vp;
3567 	struct mount *mp;
3568 	struct file *fp;
3569 	int error;
3570 
3571 	AUDIT_ARG_FD(fd);
3572 	error = getvnode(td, fd, &cap_fsync_rights, &fp);
3573 	if (error != 0)
3574 		return (error);
3575 	vp = fp->f_vnode;
3576 #if 0
3577 	if (!fullsync)
3578 		/* XXXKIB: compete outstanding aio writes */;
3579 #endif
3580 retry:
3581 	error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH);
3582 	if (error != 0)
3583 		goto drop;
3584 	vn_lock(vp, vn_lktype_write(mp, vp) | LK_RETRY);
3585 	AUDIT_ARG_VNODE1(vp);
3586 	vnode_pager_clean_async(vp);
3587 	error = fullsync ? VOP_FSYNC(vp, MNT_WAIT, td) : VOP_FDATASYNC(vp, td);
3588 	VOP_UNLOCK(vp);
3589 	vn_finished_write(mp);
3590 	if (error == ERELOOKUP)
3591 		goto retry;
3592 drop:
3593 	fdrop(fp, td);
3594 	return (error);
3595 }
3596 
3597 /*
3598  * Sync an open file.
3599  */
3600 #ifndef _SYS_SYSPROTO_H_
3601 struct fsync_args {
3602 	int	fd;
3603 };
3604 #endif
3605 int
sys_fsync(struct thread * td,struct fsync_args * uap)3606 sys_fsync(struct thread *td, struct fsync_args *uap)
3607 {
3608 
3609 	return (kern_fsync(td, uap->fd, true));
3610 }
3611 
3612 int
sys_fdatasync(struct thread * td,struct fdatasync_args * uap)3613 sys_fdatasync(struct thread *td, struct fdatasync_args *uap)
3614 {
3615 
3616 	return (kern_fsync(td, uap->fd, false));
3617 }
3618 
3619 /*
3620  * Rename files.  Source and destination must either both be directories, or
3621  * both not be directories.  If target is a directory, it must be empty.
3622  */
3623 #ifndef _SYS_SYSPROTO_H_
3624 struct rename_args {
3625 	char	*from;
3626 	char	*to;
3627 };
3628 #endif
3629 int
sys_rename(struct thread * td,struct rename_args * uap)3630 sys_rename(struct thread *td, struct rename_args *uap)
3631 {
3632 
3633 	return (kern_renameat(td, AT_FDCWD, uap->from, AT_FDCWD,
3634 	    uap->to, UIO_USERSPACE));
3635 }
3636 
3637 #ifndef _SYS_SYSPROTO_H_
3638 struct renameat_args {
3639 	int	oldfd;
3640 	char	*old;
3641 	int	newfd;
3642 	char	*new;
3643 };
3644 #endif
3645 int
sys_renameat(struct thread * td,struct renameat_args * uap)3646 sys_renameat(struct thread *td, struct renameat_args *uap)
3647 {
3648 
3649 	return (kern_renameat(td, uap->oldfd, uap->old, uap->newfd, uap->new,
3650 	    UIO_USERSPACE));
3651 }
3652 
3653 #ifdef MAC
3654 static int
kern_renameat_mac(struct thread * td,int oldfd,const char * old,int newfd,const char * new,enum uio_seg pathseg,struct nameidata * fromnd)3655 kern_renameat_mac(struct thread *td, int oldfd, const char *old, int newfd,
3656     const char *new, enum uio_seg pathseg, struct nameidata *fromnd)
3657 {
3658 	int error;
3659 
3660 	NDINIT_ATRIGHTS(fromnd, DELETE, LOCKPARENT | LOCKLEAF | AUDITVNODE1,
3661 	    pathseg, old, oldfd, &cap_renameat_source_rights);
3662 	if ((error = namei(fromnd)) != 0)
3663 		return (error);
3664 	error = mac_vnode_check_rename_from(td->td_ucred, fromnd->ni_dvp,
3665 	    fromnd->ni_vp, &fromnd->ni_cnd);
3666 	VOP_UNLOCK(fromnd->ni_dvp);
3667 	if (fromnd->ni_dvp != fromnd->ni_vp)
3668 		VOP_UNLOCK(fromnd->ni_vp);
3669 	if (error != 0) {
3670 		NDFREE_PNBUF(fromnd);
3671 		vrele(fromnd->ni_dvp);
3672 		vrele(fromnd->ni_vp);
3673 	}
3674 	return (error);
3675 }
3676 #endif
3677 
3678 int
kern_renameat(struct thread * td,int oldfd,const char * old,int newfd,const char * new,enum uio_seg pathseg)3679 kern_renameat(struct thread *td, int oldfd, const char *old, int newfd,
3680     const char *new, enum uio_seg pathseg)
3681 {
3682 	struct mount *mp = NULL;
3683 	struct vnode *tvp, *fvp, *tdvp;
3684 	struct nameidata fromnd, tond;
3685 	uint64_t tondflags;
3686 	int error;
3687 
3688 again:
3689 	bwillwrite();
3690 #ifdef MAC
3691 	if (mac_vnode_check_rename_from_enabled()) {
3692 		error = kern_renameat_mac(td, oldfd, old, newfd, new, pathseg,
3693 		    &fromnd);
3694 		if (error != 0)
3695 			return (error);
3696 	} else {
3697 #endif
3698 	NDINIT_ATRIGHTS(&fromnd, DELETE, WANTPARENT | AUDITVNODE1,
3699 	    pathseg, old, oldfd, &cap_renameat_source_rights);
3700 	if ((error = namei(&fromnd)) != 0)
3701 		return (error);
3702 #ifdef MAC
3703 	}
3704 #endif
3705 	fvp = fromnd.ni_vp;
3706 	tondflags = LOCKPARENT | LOCKLEAF | NOCACHE | AUDITVNODE2;
3707 	if (fromnd.ni_vp->v_type == VDIR)
3708 		tondflags |= WILLBEDIR;
3709 	NDINIT_ATRIGHTS(&tond, RENAME, tondflags, pathseg, new, newfd,
3710 	    &cap_renameat_target_rights);
3711 	if ((error = namei(&tond)) != 0) {
3712 		/* Translate error code for rename("dir1", "dir2/."). */
3713 		if (error == EISDIR && fvp->v_type == VDIR)
3714 			error = EINVAL;
3715 		NDFREE_PNBUF(&fromnd);
3716 		vrele(fromnd.ni_dvp);
3717 		vrele(fvp);
3718 		goto out1;
3719 	}
3720 	tdvp = tond.ni_dvp;
3721 	tvp = tond.ni_vp;
3722 	error = vn_start_write(fvp, &mp, V_NOWAIT);
3723 	if (error != 0) {
3724 		NDFREE_PNBUF(&fromnd);
3725 		NDFREE_PNBUF(&tond);
3726 		if (tvp != NULL)
3727 			vput(tvp);
3728 		if (tdvp == tvp)
3729 			vrele(tdvp);
3730 		else
3731 			vput(tdvp);
3732 		vrele(fromnd.ni_dvp);
3733 		vrele(fvp);
3734 		error = vn_start_write(NULL, &mp, V_XSLEEP | V_PCATCH);
3735 		if (error != 0)
3736 			return (error);
3737 		goto again;
3738 	}
3739 	if (tvp != NULL) {
3740 		if (fvp->v_type == VDIR && tvp->v_type != VDIR) {
3741 			error = ENOTDIR;
3742 			goto out;
3743 		} else if (fvp->v_type != VDIR && tvp->v_type == VDIR) {
3744 			error = EISDIR;
3745 			goto out;
3746 		}
3747 #ifdef CAPABILITIES
3748 		if (newfd != AT_FDCWD && (tond.ni_resflags & NIRES_ABS) == 0) {
3749 			/*
3750 			 * If the target already exists we require CAP_UNLINKAT
3751 			 * from 'newfd', when newfd was used for the lookup.
3752 			 */
3753 			error = cap_check(&tond.ni_filecaps.fc_rights,
3754 			    &cap_unlinkat_rights);
3755 			if (error != 0)
3756 				goto out;
3757 		}
3758 #endif
3759 	}
3760 	if (fvp == tdvp) {
3761 		error = EINVAL;
3762 		goto out;
3763 	}
3764 	/*
3765 	 * If the source is the same as the destination (that is, if they
3766 	 * are links to the same vnode), then there is nothing to do.
3767 	 */
3768 	if (fvp == tvp)
3769 		error = ERESTART;
3770 #ifdef MAC
3771 	else
3772 		error = mac_vnode_check_rename_to(td->td_ucred, tdvp,
3773 		    tond.ni_vp, fromnd.ni_dvp == tdvp, &tond.ni_cnd);
3774 #endif
3775 out:
3776 	if (error == 0) {
3777 		error = VOP_RENAME(fromnd.ni_dvp, fromnd.ni_vp, &fromnd.ni_cnd,
3778 		    tond.ni_dvp, tond.ni_vp, &tond.ni_cnd);
3779 		NDFREE_PNBUF(&fromnd);
3780 		NDFREE_PNBUF(&tond);
3781 	} else {
3782 		NDFREE_PNBUF(&fromnd);
3783 		NDFREE_PNBUF(&tond);
3784 		if (tvp != NULL)
3785 			vput(tvp);
3786 		if (tdvp == tvp)
3787 			vrele(tdvp);
3788 		else
3789 			vput(tdvp);
3790 		vrele(fromnd.ni_dvp);
3791 		vrele(fvp);
3792 	}
3793 	vn_finished_write(mp);
3794 out1:
3795 	if (error == ERESTART)
3796 		return (0);
3797 	if (error == ERELOOKUP)
3798 		goto again;
3799 	return (error);
3800 }
3801 
3802 /*
3803  * Make a directory file.
3804  */
3805 #ifndef _SYS_SYSPROTO_H_
3806 struct mkdir_args {
3807 	char	*path;
3808 	int	mode;
3809 };
3810 #endif
3811 int
sys_mkdir(struct thread * td,struct mkdir_args * uap)3812 sys_mkdir(struct thread *td, struct mkdir_args *uap)
3813 {
3814 
3815 	return (kern_mkdirat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
3816 	    uap->mode));
3817 }
3818 
3819 #ifndef _SYS_SYSPROTO_H_
3820 struct mkdirat_args {
3821 	int	fd;
3822 	char	*path;
3823 	mode_t	mode;
3824 };
3825 #endif
3826 int
sys_mkdirat(struct thread * td,struct mkdirat_args * uap)3827 sys_mkdirat(struct thread *td, struct mkdirat_args *uap)
3828 {
3829 
3830 	return (kern_mkdirat(td, uap->fd, uap->path, UIO_USERSPACE, uap->mode));
3831 }
3832 
3833 int
kern_mkdirat(struct thread * td,int fd,const char * path,enum uio_seg segflg,int mode)3834 kern_mkdirat(struct thread *td, int fd, const char *path, enum uio_seg segflg,
3835     int mode)
3836 {
3837 	struct mount *mp;
3838 	struct vattr vattr;
3839 	struct nameidata nd;
3840 	int error;
3841 
3842 	AUDIT_ARG_MODE(mode);
3843 	NDPREINIT(&nd);
3844 restart:
3845 	bwillwrite();
3846 	NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | AUDITVNODE1 |
3847 	    NC_NOMAKEENTRY | NC_KEEPPOSENTRY | FAILIFEXISTS | WILLBEDIR,
3848 	    segflg, path, fd, &cap_mkdirat_rights);
3849 	if ((error = namei(&nd)) != 0)
3850 		return (error);
3851 	if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
3852 		NDFREE_PNBUF(&nd);
3853 		vput(nd.ni_dvp);
3854 		if ((error = vn_start_write(NULL, &mp, V_XSLEEP | V_PCATCH)) != 0)
3855 			return (error);
3856 		goto restart;
3857 	}
3858 	VATTR_NULL(&vattr);
3859 	vattr.va_type = VDIR;
3860 	vattr.va_mode = (mode & ACCESSPERMS) &~ td->td_proc->p_pd->pd_cmask;
3861 #ifdef MAC
3862 	error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
3863 	    &vattr);
3864 	if (error != 0)
3865 		goto out;
3866 #endif
3867 	error = VOP_MKDIR(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
3868 #ifdef MAC
3869 out:
3870 #endif
3871 	NDFREE_PNBUF(&nd);
3872 	VOP_VPUT_PAIR(nd.ni_dvp, error == 0 ? &nd.ni_vp : NULL, true);
3873 	vn_finished_write(mp);
3874 	if (error == ERELOOKUP)
3875 		goto restart;
3876 	return (error);
3877 }
3878 
3879 /*
3880  * Remove a directory file.
3881  */
3882 #ifndef _SYS_SYSPROTO_H_
3883 struct rmdir_args {
3884 	char	*path;
3885 };
3886 #endif
3887 int
sys_rmdir(struct thread * td,struct rmdir_args * uap)3888 sys_rmdir(struct thread *td, struct rmdir_args *uap)
3889 {
3890 
3891 	return (kern_frmdirat(td, AT_FDCWD, uap->path, FD_NONE, UIO_USERSPACE,
3892 	    0));
3893 }
3894 
3895 int
kern_frmdirat(struct thread * td,int dfd,const char * path,int fd,enum uio_seg pathseg,int flag)3896 kern_frmdirat(struct thread *td, int dfd, const char *path, int fd,
3897     enum uio_seg pathseg, int flag)
3898 {
3899 	struct mount *mp;
3900 	struct vnode *vp;
3901 	struct file *fp;
3902 	struct nameidata nd;
3903 	cap_rights_t rights;
3904 	int error;
3905 
3906 	fp = NULL;
3907 	if (fd != FD_NONE) {
3908 		error = getvnode(td, fd, cap_rights_init_one(&rights,
3909 		    CAP_LOOKUP), &fp);
3910 		if (error != 0)
3911 			return (error);
3912 	}
3913 
3914 	NDPREINIT(&nd);
3915 restart:
3916 	bwillwrite();
3917 	NDINIT_ATRIGHTS(&nd, DELETE, LOCKPARENT | LOCKLEAF | AUDITVNODE1 |
3918 	    at2cnpflags(flag, AT_RESOLVE_BENEATH),
3919 	    pathseg, path, dfd, &cap_unlinkat_rights);
3920 	if ((error = namei(&nd)) != 0)
3921 		goto fdout;
3922 	vp = nd.ni_vp;
3923 	if (vp->v_type != VDIR) {
3924 		error = ENOTDIR;
3925 		goto out;
3926 	}
3927 	/*
3928 	 * No rmdir "." please.
3929 	 */
3930 	if (nd.ni_dvp == vp) {
3931 		error = EINVAL;
3932 		goto out;
3933 	}
3934 	/*
3935 	 * The root of a mounted filesystem cannot be deleted.
3936 	 */
3937 	if (vp->v_vflag & VV_ROOT) {
3938 		error = EBUSY;
3939 		goto out;
3940 	}
3941 
3942 	if (fp != NULL && fp->f_vnode != vp) {
3943 		if (VN_IS_DOOMED(fp->f_vnode))
3944 			error = EBADF;
3945 		else
3946 			error = EDEADLK;
3947 		goto out;
3948 	}
3949 
3950 #ifdef MAC
3951 	error = mac_vnode_check_unlink(td->td_ucred, nd.ni_dvp, vp,
3952 	    &nd.ni_cnd);
3953 	if (error != 0)
3954 		goto out;
3955 #endif
3956 	if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
3957 		NDFREE_PNBUF(&nd);
3958 		vput(vp);
3959 		if (nd.ni_dvp == vp)
3960 			vrele(nd.ni_dvp);
3961 		else
3962 			vput(nd.ni_dvp);
3963 		if ((error = vn_start_write(NULL, &mp, V_XSLEEP | V_PCATCH)) != 0)
3964 			goto fdout;
3965 		goto restart;
3966 	}
3967 	vfs_notify_upper(vp, VFS_NOTIFY_UPPER_UNLINK);
3968 	error = VOP_RMDIR(nd.ni_dvp, nd.ni_vp, &nd.ni_cnd);
3969 	vn_finished_write(mp);
3970 out:
3971 	NDFREE_PNBUF(&nd);
3972 	vput(vp);
3973 	if (nd.ni_dvp == vp)
3974 		vrele(nd.ni_dvp);
3975 	else
3976 		vput(nd.ni_dvp);
3977 	if (error == ERELOOKUP)
3978 		goto restart;
3979 fdout:
3980 	if (fp != NULL)
3981 		fdrop(fp, td);
3982 	return (error);
3983 }
3984 
3985 #if defined(COMPAT_43) || defined(COMPAT_FREEBSD11)
3986 int
freebsd11_kern_getdirentries(struct thread * td,int fd,char * ubuf,u_int count,long * basep,void (* func)(struct freebsd11_dirent *))3987 freebsd11_kern_getdirentries(struct thread *td, int fd, char *ubuf, u_int count,
3988     long *basep, void (*func)(struct freebsd11_dirent *))
3989 {
3990 	struct freebsd11_dirent dstdp;
3991 	struct dirent *dp, *edp;
3992 	char *dirbuf;
3993 	off_t base;
3994 	ssize_t resid, ucount;
3995 	int error;
3996 
3997 	/* XXX arbitrary sanity limit on `count'. */
3998 	count = min(count, 64 * 1024);
3999 
4000 	dirbuf = malloc(count, M_TEMP, M_WAITOK);
4001 
4002 	error = kern_getdirentries(td, fd, dirbuf, count, &base, &resid,
4003 	    UIO_SYSSPACE);
4004 	if (error != 0)
4005 		goto done;
4006 	if (basep != NULL)
4007 		*basep = base;
4008 
4009 	ucount = 0;
4010 	for (dp = (struct dirent *)dirbuf,
4011 	    edp = (struct dirent *)&dirbuf[count - resid];
4012 	    ucount < count && dp < edp; ) {
4013 		if (dp->d_reclen == 0)
4014 			break;
4015 		MPASS(dp->d_reclen >= _GENERIC_DIRLEN(0));
4016 		if (dp->d_namlen >= sizeof(dstdp.d_name))
4017 			continue;
4018 		dstdp.d_type = dp->d_type;
4019 		dstdp.d_namlen = dp->d_namlen;
4020 		dstdp.d_fileno = dp->d_fileno;		/* truncate */
4021 		if (dstdp.d_fileno != dp->d_fileno) {
4022 			switch (ino64_trunc_error) {
4023 			default:
4024 			case 0:
4025 				break;
4026 			case 1:
4027 				error = EOVERFLOW;
4028 				goto done;
4029 			case 2:
4030 				dstdp.d_fileno = UINT32_MAX;
4031 				break;
4032 			}
4033 		}
4034 		dstdp.d_reclen = sizeof(dstdp) - sizeof(dstdp.d_name) +
4035 		    ((dp->d_namlen + 1 + 3) &~ 3);
4036 		bcopy(dp->d_name, dstdp.d_name, dstdp.d_namlen);
4037 		bzero(dstdp.d_name + dstdp.d_namlen,
4038 		    dstdp.d_reclen - offsetof(struct freebsd11_dirent, d_name) -
4039 		    dstdp.d_namlen);
4040 		MPASS(dstdp.d_reclen <= dp->d_reclen);
4041 		MPASS(ucount + dstdp.d_reclen <= count);
4042 		if (func != NULL)
4043 			func(&dstdp);
4044 		error = copyout(&dstdp, ubuf + ucount, dstdp.d_reclen);
4045 		if (error != 0)
4046 			break;
4047 		dp = (struct dirent *)((char *)dp + dp->d_reclen);
4048 		ucount += dstdp.d_reclen;
4049 	}
4050 
4051 done:
4052 	free(dirbuf, M_TEMP);
4053 	if (error == 0)
4054 		td->td_retval[0] = ucount;
4055 	return (error);
4056 }
4057 #endif /* COMPAT */
4058 
4059 #ifdef COMPAT_43
4060 static void
ogetdirentries_cvt(struct freebsd11_dirent * dp)4061 ogetdirentries_cvt(struct freebsd11_dirent *dp)
4062 {
4063 #if (BYTE_ORDER == LITTLE_ENDIAN)
4064 	/*
4065 	 * The expected low byte of dp->d_namlen is our dp->d_type.
4066 	 * The high MBZ byte of dp->d_namlen is our dp->d_namlen.
4067 	 */
4068 	dp->d_type = dp->d_namlen;
4069 	dp->d_namlen = 0;
4070 #else
4071 	/*
4072 	 * The dp->d_type is the high byte of the expected dp->d_namlen,
4073 	 * so must be zero'ed.
4074 	 */
4075 	dp->d_type = 0;
4076 #endif
4077 }
4078 
4079 /*
4080  * Read a block of directory entries in a filesystem independent format.
4081  */
4082 #ifndef _SYS_SYSPROTO_H_
4083 struct ogetdirentries_args {
4084 	int	fd;
4085 	char	*buf;
4086 	u_int	count;
4087 	long	*basep;
4088 };
4089 #endif
4090 int
ogetdirentries(struct thread * td,struct ogetdirentries_args * uap)4091 ogetdirentries(struct thread *td, struct ogetdirentries_args *uap)
4092 {
4093 	long loff;
4094 	int error;
4095 
4096 	error = kern_ogetdirentries(td, uap, &loff);
4097 	if (error == 0)
4098 		error = copyout(&loff, uap->basep, sizeof(long));
4099 	return (error);
4100 }
4101 
4102 int
kern_ogetdirentries(struct thread * td,struct ogetdirentries_args * uap,long * ploff)4103 kern_ogetdirentries(struct thread *td, struct ogetdirentries_args *uap,
4104     long *ploff)
4105 {
4106 	long base;
4107 	int error;
4108 
4109 	/* XXX arbitrary sanity limit on `count'. */
4110 	if (uap->count > 64 * 1024)
4111 		return (EINVAL);
4112 
4113 	error = freebsd11_kern_getdirentries(td, uap->fd, uap->buf, uap->count,
4114 	    &base, ogetdirentries_cvt);
4115 
4116 	if (error == 0 && uap->basep != NULL)
4117 		error = copyout(&base, uap->basep, sizeof(long));
4118 
4119 	return (error);
4120 }
4121 #endif /* COMPAT_43 */
4122 
4123 #if defined(COMPAT_FREEBSD11)
4124 #ifndef _SYS_SYSPROTO_H_
4125 struct freebsd11_getdirentries_args {
4126 	int	fd;
4127 	char	*buf;
4128 	u_int	count;
4129 	long	*basep;
4130 };
4131 #endif
4132 int
freebsd11_getdirentries(struct thread * td,struct freebsd11_getdirentries_args * uap)4133 freebsd11_getdirentries(struct thread *td,
4134     struct freebsd11_getdirentries_args *uap)
4135 {
4136 	long base;
4137 	int error;
4138 
4139 	error = freebsd11_kern_getdirentries(td, uap->fd, uap->buf, uap->count,
4140 	    &base, NULL);
4141 
4142 	if (error == 0 && uap->basep != NULL)
4143 		error = copyout(&base, uap->basep, sizeof(long));
4144 	return (error);
4145 }
4146 
4147 int
freebsd11_getdents(struct thread * td,struct freebsd11_getdents_args * uap)4148 freebsd11_getdents(struct thread *td, struct freebsd11_getdents_args *uap)
4149 {
4150 	struct freebsd11_getdirentries_args ap;
4151 
4152 	ap.fd = uap->fd;
4153 	ap.buf = uap->buf;
4154 	ap.count = uap->count;
4155 	ap.basep = NULL;
4156 	return (freebsd11_getdirentries(td, &ap));
4157 }
4158 #endif /* COMPAT_FREEBSD11 */
4159 
4160 /*
4161  * Read a block of directory entries in a filesystem independent format.
4162  */
4163 int
sys_getdirentries(struct thread * td,struct getdirentries_args * uap)4164 sys_getdirentries(struct thread *td, struct getdirentries_args *uap)
4165 {
4166 	off_t base;
4167 	int error;
4168 
4169 	error = kern_getdirentries(td, uap->fd, uap->buf, uap->count, &base,
4170 	    NULL, UIO_USERSPACE);
4171 	if (error != 0)
4172 		return (error);
4173 	if (uap->basep != NULL)
4174 		error = copyout(&base, uap->basep, sizeof(off_t));
4175 	return (error);
4176 }
4177 
4178 int
kern_getdirentries(struct thread * td,int fd,char * buf,size_t count,off_t * basep,ssize_t * residp,enum uio_seg bufseg)4179 kern_getdirentries(struct thread *td, int fd, char *buf, size_t count,
4180     off_t *basep, ssize_t *residp, enum uio_seg bufseg)
4181 {
4182 	struct vnode *vp;
4183 	struct file *fp;
4184 	struct uio auio;
4185 	struct iovec aiov;
4186 	off_t loff;
4187 	int error, eofflag;
4188 	off_t foffset;
4189 
4190 	AUDIT_ARG_FD(fd);
4191 	if (count > IOSIZE_MAX)
4192 		return (EINVAL);
4193 	auio.uio_resid = count;
4194 	error = getvnode(td, fd, &cap_read_rights, &fp);
4195 	if (error != 0)
4196 		return (error);
4197 	if ((fp->f_flag & FREAD) == 0) {
4198 		fdrop(fp, td);
4199 		return (EBADF);
4200 	}
4201 	vp = fp->f_vnode;
4202 	foffset = foffset_lock(fp, 0);
4203 unionread:
4204 	if (vp->v_type != VDIR) {
4205 		error = EINVAL;
4206 		goto fail;
4207 	}
4208 	if (__predict_false((vp->v_vflag & VV_UNLINKED) != 0)) {
4209 		error = ENOENT;
4210 		goto fail;
4211 	}
4212 	aiov.iov_base = buf;
4213 	aiov.iov_len = count;
4214 	auio.uio_iov = &aiov;
4215 	auio.uio_iovcnt = 1;
4216 	auio.uio_rw = UIO_READ;
4217 	auio.uio_segflg = bufseg;
4218 	auio.uio_td = td;
4219 	vn_lock(vp, LK_SHARED | LK_RETRY);
4220 	AUDIT_ARG_VNODE1(vp);
4221 	loff = auio.uio_offset = foffset;
4222 #ifdef MAC
4223 	error = mac_vnode_check_readdir(td->td_ucred, vp);
4224 	if (error == 0)
4225 #endif
4226 		error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, NULL,
4227 		    NULL);
4228 	foffset = auio.uio_offset;
4229 	if (error != 0) {
4230 		VOP_UNLOCK(vp);
4231 		goto fail;
4232 	}
4233 	if (count == auio.uio_resid &&
4234 	    (vp->v_vflag & VV_ROOT) &&
4235 	    (vp->v_mount->mnt_flag & MNT_UNION)) {
4236 		struct vnode *tvp = vp;
4237 
4238 		vp = vp->v_mount->mnt_vnodecovered;
4239 		VREF(vp);
4240 		fp->f_vnode = vp;
4241 		foffset = 0;
4242 		vput(tvp);
4243 		goto unionread;
4244 	}
4245 	VOP_UNLOCK(vp);
4246 	*basep = loff;
4247 	if (residp != NULL)
4248 		*residp = auio.uio_resid;
4249 	td->td_retval[0] = count - auio.uio_resid;
4250 fail:
4251 	foffset_unlock(fp, foffset, 0);
4252 	fdrop(fp, td);
4253 	return (error);
4254 }
4255 
4256 /*
4257  * Set the mode mask for creation of filesystem nodes.
4258  */
4259 #ifndef _SYS_SYSPROTO_H_
4260 struct umask_args {
4261 	int	newmask;
4262 };
4263 #endif
4264 int
sys_umask(struct thread * td,struct umask_args * uap)4265 sys_umask(struct thread *td, struct umask_args *uap)
4266 {
4267 	struct pwddesc *pdp;
4268 
4269 	pdp = td->td_proc->p_pd;
4270 	PWDDESC_XLOCK(pdp);
4271 	td->td_retval[0] = pdp->pd_cmask;
4272 	pdp->pd_cmask = uap->newmask & ALLPERMS;
4273 	PWDDESC_XUNLOCK(pdp);
4274 	return (0);
4275 }
4276 
4277 /*
4278  * Void all references to file by ripping underlying filesystem away from
4279  * vnode.
4280  */
4281 #ifndef _SYS_SYSPROTO_H_
4282 struct revoke_args {
4283 	char	*path;
4284 };
4285 #endif
4286 int
sys_revoke(struct thread * td,struct revoke_args * uap)4287 sys_revoke(struct thread *td, struct revoke_args *uap)
4288 {
4289 	struct vnode *vp;
4290 	struct vattr vattr;
4291 	struct nameidata nd;
4292 	int error;
4293 
4294 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, UIO_USERSPACE,
4295 	    uap->path);
4296 	if ((error = namei(&nd)) != 0)
4297 		return (error);
4298 	vp = nd.ni_vp;
4299 	NDFREE_PNBUF(&nd);
4300 	if (vp->v_type != VCHR || vp->v_rdev == NULL) {
4301 		error = EINVAL;
4302 		goto out;
4303 	}
4304 #ifdef MAC
4305 	error = mac_vnode_check_revoke(td->td_ucred, vp);
4306 	if (error != 0)
4307 		goto out;
4308 #endif
4309 	error = VOP_GETATTR(vp, &vattr, td->td_ucred);
4310 	if (error != 0)
4311 		goto out;
4312 	if (td->td_ucred->cr_uid != vattr.va_uid) {
4313 		error = priv_check(td, PRIV_VFS_ADMIN);
4314 		if (error != 0)
4315 			goto out;
4316 	}
4317 	if (devfs_usecount(vp) > 0)
4318 		VOP_REVOKE(vp, REVOKEALL);
4319 out:
4320 	vput(vp);
4321 	return (error);
4322 }
4323 
4324 /*
4325  * This variant of getvnode() allows O_PATH files.  Caller should
4326  * ensure that returned file and vnode are only used for compatible
4327  * semantics.
4328  */
4329 int
getvnode_path(struct thread * td,int fd,cap_rights_t * rightsp,struct file ** fpp)4330 getvnode_path(struct thread *td, int fd, cap_rights_t *rightsp,
4331     struct file **fpp)
4332 {
4333 	struct file *fp;
4334 	int error;
4335 
4336 	error = fget_unlocked(td, fd, rightsp, &fp);
4337 	if (error != 0)
4338 		return (error);
4339 
4340 	/*
4341 	 * The file could be not of the vnode type, or it may be not
4342 	 * yet fully initialized, in which case the f_vnode pointer
4343 	 * may be set, but f_ops is still badfileops.  E.g.,
4344 	 * devfs_open() transiently create such situation to
4345 	 * facilitate csw d_fdopen().
4346 	 *
4347 	 * Dupfdopen() handling in kern_openat() installs the
4348 	 * half-baked file into the process descriptor table, allowing
4349 	 * other thread to dereference it. Guard against the race by
4350 	 * checking f_ops.
4351 	 */
4352 	if (__predict_false(fp->f_vnode == NULL || fp->f_ops == &badfileops)) {
4353 		fdrop(fp, td);
4354 		*fpp = NULL;
4355 		return (EINVAL);
4356 	}
4357 
4358 	*fpp = fp;
4359 	return (0);
4360 }
4361 
4362 /*
4363  * Convert a user file descriptor to a kernel file entry and check
4364  * that, if it is a capability, the correct rights are present.
4365  * A reference on the file entry is held upon returning.
4366  */
4367 int
getvnode(struct thread * td,int fd,cap_rights_t * rightsp,struct file ** fpp)4368 getvnode(struct thread *td, int fd, cap_rights_t *rightsp, struct file **fpp)
4369 {
4370 	int error;
4371 
4372 	error = getvnode_path(td, fd, rightsp, fpp);
4373 	if (__predict_false(error != 0))
4374 		return (error);
4375 
4376 	/*
4377 	 * Filter out O_PATH file descriptors, most getvnode() callers
4378 	 * do not call fo_ methods.
4379 	 */
4380 	if (__predict_false((*fpp)->f_ops == &path_fileops)) {
4381 		fdrop(*fpp, td);
4382 		*fpp = NULL;
4383 		error = EBADF;
4384 	}
4385 
4386 	return (error);
4387 }
4388 
4389 /*
4390  * Get an (NFS) file handle.
4391  */
4392 #ifndef _SYS_SYSPROTO_H_
4393 struct lgetfh_args {
4394 	char *fname;
4395 	fhandle_t *fhp;
4396 };
4397 #endif
4398 int
sys_lgetfh(struct thread * td,struct lgetfh_args * uap)4399 sys_lgetfh(struct thread *td, struct lgetfh_args *uap)
4400 {
4401 
4402 	return (kern_getfhat(td, AT_SYMLINK_NOFOLLOW, AT_FDCWD, uap->fname,
4403 	    UIO_USERSPACE, uap->fhp, UIO_USERSPACE));
4404 }
4405 
4406 #ifndef _SYS_SYSPROTO_H_
4407 struct getfh_args {
4408 	char *fname;
4409 	fhandle_t *fhp;
4410 };
4411 #endif
4412 int
sys_getfh(struct thread * td,struct getfh_args * uap)4413 sys_getfh(struct thread *td, struct getfh_args *uap)
4414 {
4415 
4416 	return (kern_getfhat(td, 0, AT_FDCWD, uap->fname, UIO_USERSPACE,
4417 	    uap->fhp, UIO_USERSPACE));
4418 }
4419 
4420 /*
4421  * syscall for the rpc.lockd to use to translate an open descriptor into
4422  * a NFS file handle.
4423  *
4424  * warning: do not remove the priv_check() call or this becomes one giant
4425  * security hole.
4426  */
4427 #ifndef _SYS_SYSPROTO_H_
4428 struct getfhat_args {
4429 	int fd;
4430 	char *path;
4431 	fhandle_t *fhp;
4432 	int flags;
4433 };
4434 #endif
4435 int
sys_getfhat(struct thread * td,struct getfhat_args * uap)4436 sys_getfhat(struct thread *td, struct getfhat_args *uap)
4437 {
4438 
4439 	return (kern_getfhat(td, uap->flags, uap->fd, uap->path, UIO_USERSPACE,
4440 	    uap->fhp, UIO_USERSPACE));
4441 }
4442 
4443 int
kern_getfhat(struct thread * td,int flags,int fd,const char * path,enum uio_seg pathseg,fhandle_t * fhp,enum uio_seg fhseg)4444 kern_getfhat(struct thread *td, int flags, int fd, const char *path,
4445     enum uio_seg pathseg, fhandle_t *fhp, enum uio_seg fhseg)
4446 {
4447 	struct nameidata nd;
4448 	fhandle_t fh;
4449 	struct vnode *vp;
4450 	int error;
4451 
4452 	if ((flags & ~(AT_SYMLINK_NOFOLLOW | AT_RESOLVE_BENEATH)) != 0)
4453 		return (EINVAL);
4454 	error = priv_check(td, PRIV_VFS_GETFH);
4455 	if (error != 0)
4456 		return (error);
4457 	NDINIT_AT(&nd, LOOKUP, at2cnpflags(flags, AT_SYMLINK_NOFOLLOW |
4458 	    AT_RESOLVE_BENEATH) | LOCKLEAF | AUDITVNODE1, pathseg, path,
4459 	    fd);
4460 	error = namei(&nd);
4461 	if (error != 0)
4462 		return (error);
4463 	NDFREE_PNBUF(&nd);
4464 	vp = nd.ni_vp;
4465 	bzero(&fh, sizeof(fh));
4466 	fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
4467 	error = VOP_VPTOFH(vp, &fh.fh_fid);
4468 	vput(vp);
4469 	if (error == 0) {
4470 		if (fhseg == UIO_USERSPACE)
4471 			error = copyout(&fh, fhp, sizeof (fh));
4472 		else
4473 			memcpy(fhp, &fh, sizeof(fh));
4474 	}
4475 	return (error);
4476 }
4477 
4478 #ifndef _SYS_SYSPROTO_H_
4479 struct fhlink_args {
4480 	fhandle_t *fhp;
4481 	const char *to;
4482 };
4483 #endif
4484 int
sys_fhlink(struct thread * td,struct fhlink_args * uap)4485 sys_fhlink(struct thread *td, struct fhlink_args *uap)
4486 {
4487 
4488 	return (kern_fhlinkat(td, AT_FDCWD, uap->to, UIO_USERSPACE, uap->fhp));
4489 }
4490 
4491 #ifndef _SYS_SYSPROTO_H_
4492 struct fhlinkat_args {
4493 	fhandle_t *fhp;
4494 	int tofd;
4495 	const char *to;
4496 };
4497 #endif
4498 int
sys_fhlinkat(struct thread * td,struct fhlinkat_args * uap)4499 sys_fhlinkat(struct thread *td, struct fhlinkat_args *uap)
4500 {
4501 
4502 	return (kern_fhlinkat(td, uap->tofd, uap->to, UIO_USERSPACE, uap->fhp));
4503 }
4504 
4505 static int
kern_fhlinkat(struct thread * td,int fd,const char * path,enum uio_seg pathseg,fhandle_t * fhp)4506 kern_fhlinkat(struct thread *td, int fd, const char *path,
4507     enum uio_seg pathseg, fhandle_t *fhp)
4508 {
4509 	fhandle_t fh;
4510 	struct mount *mp;
4511 	struct vnode *vp;
4512 	int error;
4513 
4514 	error = priv_check(td, PRIV_VFS_GETFH);
4515 	if (error != 0)
4516 		return (error);
4517 	error = copyin(fhp, &fh, sizeof(fh));
4518 	if (error != 0)
4519 		return (error);
4520 	do {
4521 		bwillwrite();
4522 		if ((mp = vfs_busyfs(&fh.fh_fsid)) == NULL)
4523 			return (ESTALE);
4524 		error = VFS_FHTOVP(mp, &fh.fh_fid, LK_SHARED, &vp);
4525 		vfs_unbusy(mp);
4526 		if (error != 0)
4527 			return (error);
4528 		VOP_UNLOCK(vp);
4529 		error = kern_linkat_vp(td, vp, fd, path, pathseg);
4530 	} while (error == EAGAIN || error == ERELOOKUP);
4531 	return (error);
4532 }
4533 
4534 #ifndef _SYS_SYSPROTO_H_
4535 struct fhreadlink_args {
4536 	fhandle_t *fhp;
4537 	char *buf;
4538 	size_t bufsize;
4539 };
4540 #endif
4541 int
sys_fhreadlink(struct thread * td,struct fhreadlink_args * uap)4542 sys_fhreadlink(struct thread *td, struct fhreadlink_args *uap)
4543 {
4544 	fhandle_t fh;
4545 	struct mount *mp;
4546 	struct vnode *vp;
4547 	int error;
4548 
4549 	error = priv_check(td, PRIV_VFS_GETFH);
4550 	if (error != 0)
4551 		return (error);
4552 	if (uap->bufsize > IOSIZE_MAX)
4553 		return (EINVAL);
4554 	error = copyin(uap->fhp, &fh, sizeof(fh));
4555 	if (error != 0)
4556 		return (error);
4557 	if ((mp = vfs_busyfs(&fh.fh_fsid)) == NULL)
4558 		return (ESTALE);
4559 	error = VFS_FHTOVP(mp, &fh.fh_fid, LK_SHARED, &vp);
4560 	vfs_unbusy(mp);
4561 	if (error != 0)
4562 		return (error);
4563 	error = kern_readlink_vp(vp, uap->buf, UIO_USERSPACE, uap->bufsize, td);
4564 	vput(vp);
4565 	return (error);
4566 }
4567 
4568 /*
4569  * syscall for the rpc.lockd to use to translate a NFS file handle into an
4570  * open descriptor.
4571  *
4572  * warning: do not remove the priv_check() call or this becomes one giant
4573  * security hole.
4574  */
4575 #ifndef _SYS_SYSPROTO_H_
4576 struct fhopen_args {
4577 	const struct fhandle *u_fhp;
4578 	int flags;
4579 };
4580 #endif
4581 int
sys_fhopen(struct thread * td,struct fhopen_args * uap)4582 sys_fhopen(struct thread *td, struct fhopen_args *uap)
4583 {
4584 	return (kern_fhopen(td, uap->u_fhp, uap->flags));
4585 }
4586 
4587 int
kern_fhopen(struct thread * td,const struct fhandle * u_fhp,int flags)4588 kern_fhopen(struct thread *td, const struct fhandle *u_fhp, int flags)
4589 {
4590 	struct mount *mp;
4591 	struct vnode *vp;
4592 	struct fhandle fhp;
4593 	struct file *fp;
4594 	int fmode, error;
4595 	int indx;
4596 
4597 	error = priv_check(td, PRIV_VFS_FHOPEN);
4598 	if (error != 0)
4599 		return (error);
4600 	indx = -1;
4601 	fmode = FFLAGS(flags);
4602 	/* why not allow a non-read/write open for our lockd? */
4603 	if (((fmode & (FREAD | FWRITE)) == 0) || (fmode & O_CREAT))
4604 		return (EINVAL);
4605 	error = copyin(u_fhp, &fhp, sizeof(fhp));
4606 	if (error != 0)
4607 		return(error);
4608 	/* find the mount point */
4609 	mp = vfs_busyfs(&fhp.fh_fsid);
4610 	if (mp == NULL)
4611 		return (ESTALE);
4612 	/* now give me my vnode, it gets returned to me locked */
4613 	error = VFS_FHTOVP(mp, &fhp.fh_fid, LK_EXCLUSIVE, &vp);
4614 	vfs_unbusy(mp);
4615 	if (error != 0)
4616 		return (error);
4617 
4618 	error = falloc_noinstall(td, &fp);
4619 	if (error != 0) {
4620 		vput(vp);
4621 		return (error);
4622 	}
4623 	/*
4624 	 * An extra reference on `fp' has been held for us by
4625 	 * falloc_noinstall().
4626 	 */
4627 
4628 #ifdef INVARIANTS
4629 	td->td_dupfd = -1;
4630 #endif
4631 	error = vn_open_vnode(vp, fmode, td->td_ucred, td, fp);
4632 	if (error != 0) {
4633 		KASSERT(fp->f_ops == &badfileops,
4634 		    ("VOP_OPEN in fhopen() set f_ops"));
4635 		KASSERT(td->td_dupfd < 0,
4636 		    ("fhopen() encountered fdopen()"));
4637 
4638 		vput(vp);
4639 		goto bad;
4640 	}
4641 #ifdef INVARIANTS
4642 	td->td_dupfd = 0;
4643 #endif
4644 	fp->f_vnode = vp;
4645 	finit_vnode(fp, fmode, NULL, &vnops);
4646 	VOP_UNLOCK(vp);
4647 	if ((fmode & O_TRUNC) != 0) {
4648 		error = fo_truncate(fp, 0, td->td_ucred, td);
4649 		if (error != 0)
4650 			goto bad;
4651 	}
4652 
4653 	error = finstall(td, fp, &indx, fmode, NULL);
4654 bad:
4655 	fdrop(fp, td);
4656 	td->td_retval[0] = indx;
4657 	return (error);
4658 }
4659 
4660 /*
4661  * Stat an (NFS) file handle.
4662  */
4663 #ifndef _SYS_SYSPROTO_H_
4664 struct fhstat_args {
4665 	struct fhandle *u_fhp;
4666 	struct stat *sb;
4667 };
4668 #endif
4669 int
sys_fhstat(struct thread * td,struct fhstat_args * uap)4670 sys_fhstat(struct thread *td, struct fhstat_args *uap)
4671 {
4672 	struct stat sb;
4673 	struct fhandle fh;
4674 	int error;
4675 
4676 	error = copyin(uap->u_fhp, &fh, sizeof(fh));
4677 	if (error != 0)
4678 		return (error);
4679 	error = kern_fhstat(td, fh, &sb);
4680 	if (error == 0)
4681 		error = copyout(&sb, uap->sb, sizeof(sb));
4682 	return (error);
4683 }
4684 
4685 int
kern_fhstat(struct thread * td,struct fhandle fh,struct stat * sb)4686 kern_fhstat(struct thread *td, struct fhandle fh, struct stat *sb)
4687 {
4688 	struct mount *mp;
4689 	struct vnode *vp;
4690 	int error;
4691 
4692 	error = priv_check(td, PRIV_VFS_FHSTAT);
4693 	if (error != 0)
4694 		return (error);
4695 	if ((mp = vfs_busyfs(&fh.fh_fsid)) == NULL)
4696 		return (ESTALE);
4697 	error = VFS_FHTOVP(mp, &fh.fh_fid, LK_EXCLUSIVE, &vp);
4698 	vfs_unbusy(mp);
4699 	if (error != 0)
4700 		return (error);
4701 	error = VOP_STAT(vp, sb, td->td_ucred, NOCRED);
4702 	vput(vp);
4703 	return (error);
4704 }
4705 
4706 /*
4707  * Implement fstatfs() for (NFS) file handles.
4708  */
4709 #ifndef _SYS_SYSPROTO_H_
4710 struct fhstatfs_args {
4711 	struct fhandle *u_fhp;
4712 	struct statfs *buf;
4713 };
4714 #endif
4715 int
sys_fhstatfs(struct thread * td,struct fhstatfs_args * uap)4716 sys_fhstatfs(struct thread *td, struct fhstatfs_args *uap)
4717 {
4718 	struct statfs *sfp;
4719 	fhandle_t fh;
4720 	int error;
4721 
4722 	error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t));
4723 	if (error != 0)
4724 		return (error);
4725 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
4726 	error = kern_fhstatfs(td, fh, sfp);
4727 	if (error == 0)
4728 		error = copyout(sfp, uap->buf, sizeof(*sfp));
4729 	free(sfp, M_STATFS);
4730 	return (error);
4731 }
4732 
4733 int
kern_fhstatfs(struct thread * td,fhandle_t fh,struct statfs * buf)4734 kern_fhstatfs(struct thread *td, fhandle_t fh, struct statfs *buf)
4735 {
4736 	struct mount *mp;
4737 	struct vnode *vp;
4738 	int error;
4739 
4740 	error = priv_check(td, PRIV_VFS_FHSTATFS);
4741 	if (error != 0)
4742 		return (error);
4743 	if ((mp = vfs_busyfs(&fh.fh_fsid)) == NULL)
4744 		return (ESTALE);
4745 	error = VFS_FHTOVP(mp, &fh.fh_fid, LK_EXCLUSIVE, &vp);
4746 	if (error != 0) {
4747 		vfs_unbusy(mp);
4748 		return (error);
4749 	}
4750 	vput(vp);
4751 	error = prison_canseemount(td->td_ucred, mp);
4752 	if (error != 0)
4753 		goto out;
4754 #ifdef MAC
4755 	error = mac_mount_check_stat(td->td_ucred, mp);
4756 	if (error != 0)
4757 		goto out;
4758 #endif
4759 	error = VFS_STATFS(mp, buf);
4760 out:
4761 	vfs_unbusy(mp);
4762 	return (error);
4763 }
4764 
4765 /*
4766  * Unlike madvise(2), we do not make a best effort to remember every
4767  * possible caching hint.  Instead, we remember the last setting with
4768  * the exception that we will allow POSIX_FADV_NORMAL to adjust the
4769  * region of any current setting.
4770  */
4771 int
kern_posix_fadvise(struct thread * td,int fd,off_t offset,off_t len,int advice)4772 kern_posix_fadvise(struct thread *td, int fd, off_t offset, off_t len,
4773     int advice)
4774 {
4775 	struct fadvise_info *fa, *new;
4776 	struct file *fp;
4777 	struct vnode *vp;
4778 	off_t end;
4779 	int error;
4780 
4781 	if (offset < 0 || len < 0 || offset > OFF_MAX - len)
4782 		return (EINVAL);
4783 	AUDIT_ARG_VALUE(advice);
4784 	switch (advice) {
4785 	case POSIX_FADV_SEQUENTIAL:
4786 	case POSIX_FADV_RANDOM:
4787 	case POSIX_FADV_NOREUSE:
4788 		new = malloc(sizeof(*fa), M_FADVISE, M_WAITOK);
4789 		break;
4790 	case POSIX_FADV_NORMAL:
4791 	case POSIX_FADV_WILLNEED:
4792 	case POSIX_FADV_DONTNEED:
4793 		new = NULL;
4794 		break;
4795 	default:
4796 		return (EINVAL);
4797 	}
4798 	/* XXX: CAP_POSIX_FADVISE? */
4799 	AUDIT_ARG_FD(fd);
4800 	error = fget(td, fd, &cap_no_rights, &fp);
4801 	if (error != 0)
4802 		goto out;
4803 	AUDIT_ARG_FILE(td->td_proc, fp);
4804 	if ((fp->f_ops->fo_flags & DFLAG_SEEKABLE) == 0) {
4805 		error = ESPIPE;
4806 		goto out;
4807 	}
4808 	if (fp->f_type != DTYPE_VNODE) {
4809 		error = ENODEV;
4810 		goto out;
4811 	}
4812 	vp = fp->f_vnode;
4813 	if (vp->v_type != VREG) {
4814 		error = ENODEV;
4815 		goto out;
4816 	}
4817 	if (len == 0)
4818 		end = OFF_MAX;
4819 	else
4820 		end = offset + len - 1;
4821 	switch (advice) {
4822 	case POSIX_FADV_SEQUENTIAL:
4823 	case POSIX_FADV_RANDOM:
4824 	case POSIX_FADV_NOREUSE:
4825 		/*
4826 		 * Try to merge any existing non-standard region with
4827 		 * this new region if possible, otherwise create a new
4828 		 * non-standard region for this request.
4829 		 */
4830 		mtx_pool_lock(mtxpool_sleep, fp);
4831 		fa = fp->f_advice;
4832 		if (fa != NULL && fa->fa_advice == advice &&
4833 		    ((fa->fa_start <= end && fa->fa_end >= offset) ||
4834 		    (end != OFF_MAX && fa->fa_start == end + 1) ||
4835 		    (fa->fa_end != OFF_MAX && fa->fa_end + 1 == offset))) {
4836 			if (offset < fa->fa_start)
4837 				fa->fa_start = offset;
4838 			if (end > fa->fa_end)
4839 				fa->fa_end = end;
4840 		} else {
4841 			new->fa_advice = advice;
4842 			new->fa_start = offset;
4843 			new->fa_end = end;
4844 			fp->f_advice = new;
4845 			new = fa;
4846 		}
4847 		mtx_pool_unlock(mtxpool_sleep, fp);
4848 		break;
4849 	case POSIX_FADV_NORMAL:
4850 		/*
4851 		 * If a the "normal" region overlaps with an existing
4852 		 * non-standard region, trim or remove the
4853 		 * non-standard region.
4854 		 */
4855 		mtx_pool_lock(mtxpool_sleep, fp);
4856 		fa = fp->f_advice;
4857 		if (fa != NULL) {
4858 			if (offset <= fa->fa_start && end >= fa->fa_end) {
4859 				new = fa;
4860 				fp->f_advice = NULL;
4861 			} else if (offset <= fa->fa_start &&
4862 			    end >= fa->fa_start)
4863 				fa->fa_start = end + 1;
4864 			else if (offset <= fa->fa_end && end >= fa->fa_end)
4865 				fa->fa_end = offset - 1;
4866 			else if (offset >= fa->fa_start && end <= fa->fa_end) {
4867 				/*
4868 				 * If the "normal" region is a middle
4869 				 * portion of the existing
4870 				 * non-standard region, just remove
4871 				 * the whole thing rather than picking
4872 				 * one side or the other to
4873 				 * preserve.
4874 				 */
4875 				new = fa;
4876 				fp->f_advice = NULL;
4877 			}
4878 		}
4879 		mtx_pool_unlock(mtxpool_sleep, fp);
4880 		break;
4881 	case POSIX_FADV_WILLNEED:
4882 	case POSIX_FADV_DONTNEED:
4883 		error = VOP_ADVISE(vp, offset, end, advice);
4884 		break;
4885 	}
4886 out:
4887 	if (fp != NULL)
4888 		fdrop(fp, td);
4889 	free(new, M_FADVISE);
4890 	return (error);
4891 }
4892 
4893 int
sys_posix_fadvise(struct thread * td,struct posix_fadvise_args * uap)4894 sys_posix_fadvise(struct thread *td, struct posix_fadvise_args *uap)
4895 {
4896 	int error;
4897 
4898 	error = kern_posix_fadvise(td, uap->fd, uap->offset, uap->len,
4899 	    uap->advice);
4900 	return (kern_posix_error(td, error));
4901 }
4902 
4903 int
kern_copy_file_range(struct thread * td,int infd,off_t * inoffp,int outfd,off_t * outoffp,size_t len,unsigned int flags)4904 kern_copy_file_range(struct thread *td, int infd, off_t *inoffp, int outfd,
4905     off_t *outoffp, size_t len, unsigned int flags)
4906 {
4907 	struct file *infp, *outfp;
4908 	struct vnode *invp, *outvp;
4909 	int error;
4910 	size_t retlen;
4911 	void *rl_rcookie, *rl_wcookie;
4912 	off_t savinoff, savoutoff;
4913 
4914 	infp = outfp = NULL;
4915 	rl_rcookie = rl_wcookie = NULL;
4916 	savinoff = -1;
4917 	error = 0;
4918 	retlen = 0;
4919 
4920 	if (flags != 0) {
4921 		error = EINVAL;
4922 		goto out;
4923 	}
4924 	if (len > SSIZE_MAX)
4925 		/*
4926 		 * Although the len argument is size_t, the return argument
4927 		 * is ssize_t (which is signed).  Therefore a size that won't
4928 		 * fit in ssize_t can't be returned.
4929 		 */
4930 		len = SSIZE_MAX;
4931 
4932 	/* Get the file structures for the file descriptors. */
4933 	error = fget_read(td, infd,
4934 	    inoffp != NULL ? &cap_pread_rights : &cap_read_rights, &infp);
4935 	if (error != 0)
4936 		goto out;
4937 	if (infp->f_ops == &badfileops) {
4938 		error = EBADF;
4939 		goto out;
4940 	}
4941 	if (infp->f_vnode == NULL) {
4942 		error = EINVAL;
4943 		goto out;
4944 	}
4945 	error = fget_write(td, outfd,
4946 	    outoffp != NULL ? &cap_pwrite_rights : &cap_write_rights, &outfp);
4947 	if (error != 0)
4948 		goto out;
4949 	if (outfp->f_ops == &badfileops) {
4950 		error = EBADF;
4951 		goto out;
4952 	}
4953 	if (outfp->f_vnode == NULL) {
4954 		error = EINVAL;
4955 		goto out;
4956 	}
4957 
4958 	/* Set the offset pointers to the correct place. */
4959 	if (inoffp == NULL)
4960 		inoffp = &infp->f_offset;
4961 	if (outoffp == NULL)
4962 		outoffp = &outfp->f_offset;
4963 	savinoff = *inoffp;
4964 	savoutoff = *outoffp;
4965 
4966 	invp = infp->f_vnode;
4967 	outvp = outfp->f_vnode;
4968 	/* Sanity check the f_flag bits. */
4969 	if ((outfp->f_flag & (FWRITE | FAPPEND)) != FWRITE ||
4970 	    (infp->f_flag & FREAD) == 0) {
4971 		error = EBADF;
4972 		goto out;
4973 	}
4974 
4975 	/* If len == 0, just return 0. */
4976 	if (len == 0)
4977 		goto out;
4978 
4979 	/*
4980 	 * If infp and outfp refer to the same file, the byte ranges cannot
4981 	 * overlap.
4982 	 */
4983 	if (invp == outvp && ((savinoff <= savoutoff && savinoff + len >
4984 	    savoutoff) || (savinoff > savoutoff && savoutoff + len >
4985 	    savinoff))) {
4986 		error = EINVAL;
4987 		goto out;
4988 	}
4989 
4990 	/* Range lock the byte ranges for both invp and outvp. */
4991 	for (;;) {
4992 		rl_wcookie = vn_rangelock_wlock(outvp, *outoffp, *outoffp +
4993 		    len);
4994 		rl_rcookie = vn_rangelock_tryrlock(invp, *inoffp, *inoffp +
4995 		    len);
4996 		if (rl_rcookie != NULL)
4997 			break;
4998 		vn_rangelock_unlock(outvp, rl_wcookie);
4999 		rl_rcookie = vn_rangelock_rlock(invp, *inoffp, *inoffp + len);
5000 		vn_rangelock_unlock(invp, rl_rcookie);
5001 	}
5002 
5003 	retlen = len;
5004 	error = vn_copy_file_range(invp, inoffp, outvp, outoffp, &retlen,
5005 	    flags, infp->f_cred, outfp->f_cred, td);
5006 out:
5007 	if (rl_rcookie != NULL)
5008 		vn_rangelock_unlock(invp, rl_rcookie);
5009 	if (rl_wcookie != NULL)
5010 		vn_rangelock_unlock(outvp, rl_wcookie);
5011 	if (savinoff != -1 && (error == EINTR || error == ERESTART)) {
5012 		*inoffp = savinoff;
5013 		*outoffp = savoutoff;
5014 	}
5015 	if (outfp != NULL)
5016 		fdrop(outfp, td);
5017 	if (infp != NULL)
5018 		fdrop(infp, td);
5019 	td->td_retval[0] = retlen;
5020 	return (error);
5021 }
5022 
5023 int
sys_copy_file_range(struct thread * td,struct copy_file_range_args * uap)5024 sys_copy_file_range(struct thread *td, struct copy_file_range_args *uap)
5025 {
5026 	off_t inoff, outoff, *inoffp, *outoffp;
5027 	int error;
5028 
5029 	inoffp = outoffp = NULL;
5030 	if (uap->inoffp != NULL) {
5031 		error = copyin(uap->inoffp, &inoff, sizeof(off_t));
5032 		if (error != 0)
5033 			return (error);
5034 		inoffp = &inoff;
5035 	}
5036 	if (uap->outoffp != NULL) {
5037 		error = copyin(uap->outoffp, &outoff, sizeof(off_t));
5038 		if (error != 0)
5039 			return (error);
5040 		outoffp = &outoff;
5041 	}
5042 	error = kern_copy_file_range(td, uap->infd, inoffp, uap->outfd,
5043 	    outoffp, uap->len, uap->flags);
5044 	if (error == 0 && uap->inoffp != NULL)
5045 		error = copyout(inoffp, uap->inoffp, sizeof(off_t));
5046 	if (error == 0 && uap->outoffp != NULL)
5047 		error = copyout(outoffp, uap->outoffp, sizeof(off_t));
5048 	return (error);
5049 }
5050