xref: /freebsd/sys/kern/vfs_syscalls.c (revision f35525ff2053e026a423e852136d73ed93c95803)
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 
37 #include "opt_capsicum.h"
38 #include "opt_ktrace.h"
39 
40 #include <sys/systm.h>
41 #ifdef COMPAT_FREEBSD11
42 #include <sys/abi_compat.h>
43 #endif
44 #include <sys/bio.h>
45 #include <sys/buf.h>
46 #include <sys/capsicum.h>
47 #include <sys/disk.h>
48 #include <sys/dirent.h>
49 #include <sys/fcntl.h>
50 #include <sys/file.h>
51 #include <sys/filedesc.h>
52 #include <sys/filio.h>
53 #include <sys/jail.h>
54 #include <sys/kernel.h>
55 #ifdef KTRACE
56 #include <sys/ktrace.h>
57 #endif
58 #include <sys/limits.h>
59 #include <sys/linker.h>
60 #include <sys/malloc.h>
61 #include <sys/mount.h>
62 #include <sys/mutex.h>
63 #include <sys/namei.h>
64 #include <sys/priv.h>
65 #include <sys/proc.h>
66 #include <sys/rwlock.h>
67 #include <sys/sdt.h>
68 #include <sys/stat.h>
69 #include <sys/stdarg.h>
70 #include <sys/sx.h>
71 #include <sys/syscallsubr.h>
72 #include <sys/sysctl.h>
73 #include <sys/sysproto.h>
74 #include <sys/unistd.h>
75 #include <sys/vnode.h>
76 
77 #include <security/audit/audit.h>
78 #include <security/mac/mac_framework.h>
79 
80 #include <vm/vm.h>
81 #include <vm/vm_object.h>
82 #include <vm/vm_page.h>
83 #include <vm/vnode_pager.h>
84 #include <vm/uma.h>
85 
86 #include <fs/devfs/devfs.h>
87 
88 MALLOC_DEFINE(M_FADVISE, "fadvise", "posix_fadvise(2) information");
89 
90 static int kern_chflagsat(struct thread *td, int fd, const char *path,
91     enum uio_seg pathseg, u_long flags, int atflag);
92 static int setfflags(struct thread *td, struct vnode *, u_long);
93 static int getutimes(const struct timeval *, enum uio_seg, struct timespec *);
94 static int getutimens(const struct timespec *, enum uio_seg,
95     struct timespec *, int *);
96 static int setutimes(struct thread *td, struct vnode *,
97     const struct timespec *, int, int);
98 static int vn_access(struct vnode *vp, int user_flags, struct ucred *cred,
99     struct thread *td);
100 static int kern_fhlinkat(struct thread *td, int fd, const char *path,
101     enum uio_seg pathseg, fhandle_t *fhp);
102 static int kern_readlink_vp(struct vnode *vp, char *buf, enum uio_seg bufseg,
103     size_t count, struct thread *td);
104 static int kern_linkat_vp(struct thread *td, struct vnode *vp, int fd,
105     const char *path, enum uio_seg segflag);
106 
107 uint64_t
at2cnpflags(u_int at_flags,u_int mask)108 at2cnpflags(u_int at_flags, u_int mask)
109 {
110 	uint64_t res;
111 
112 	MPASS((at_flags & (AT_SYMLINK_FOLLOW | AT_SYMLINK_NOFOLLOW)) !=
113 	    (AT_SYMLINK_FOLLOW | AT_SYMLINK_NOFOLLOW));
114 
115 	res = 0;
116 	at_flags &= mask;
117 	if ((at_flags & AT_RESOLVE_BENEATH) != 0)
118 		res |= RBENEATH;
119 	if ((at_flags & AT_SYMLINK_FOLLOW) != 0)
120 		res |= FOLLOW;
121 	/* NOFOLLOW is pseudo flag */
122 	if ((mask & AT_SYMLINK_NOFOLLOW) != 0) {
123 		res |= (at_flags & AT_SYMLINK_NOFOLLOW) != 0 ? NOFOLLOW :
124 		    FOLLOW;
125 	}
126 	if ((mask & AT_EMPTY_PATH) != 0 && (at_flags & AT_EMPTY_PATH) != 0)
127 		res |= EMPTYPATH;
128 	return (res);
129 }
130 
131 int
kern_sync(struct thread * td)132 kern_sync(struct thread *td)
133 {
134 	struct mount *mp, *nmp;
135 	int save;
136 
137 	mtx_lock(&mountlist_mtx);
138 	for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
139 		if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK)) {
140 			nmp = TAILQ_NEXT(mp, mnt_list);
141 			continue;
142 		}
143 		if ((mp->mnt_flag & MNT_RDONLY) == 0 &&
144 		    vn_start_write(NULL, &mp, V_NOWAIT) == 0) {
145 			save = curthread_pflags_set(TDP_SYNCIO);
146 			vfs_periodic(mp, MNT_NOWAIT);
147 			VFS_SYNC(mp, MNT_NOWAIT);
148 			curthread_pflags_restore(save);
149 			vn_finished_write(mp);
150 		}
151 		mtx_lock(&mountlist_mtx);
152 		nmp = TAILQ_NEXT(mp, mnt_list);
153 		vfs_unbusy(mp);
154 	}
155 	mtx_unlock(&mountlist_mtx);
156 	return (0);
157 }
158 
159 /*
160  * Sync each mounted filesystem.
161  */
162 #ifndef _SYS_SYSPROTO_H_
163 struct sync_args {
164 	int     dummy;
165 };
166 #endif
167 /* ARGSUSED */
168 int
sys_sync(struct thread * td,struct sync_args * uap)169 sys_sync(struct thread *td, struct sync_args *uap)
170 {
171 
172 	return (kern_sync(td));
173 }
174 
175 /*
176  * Change filesystem quotas.
177  */
178 #ifndef _SYS_SYSPROTO_H_
179 struct quotactl_args {
180 	char *path;
181 	int cmd;
182 	int uid;
183 	caddr_t arg;
184 };
185 #endif
186 int
sys_quotactl(struct thread * td,struct quotactl_args * uap)187 sys_quotactl(struct thread *td, struct quotactl_args *uap)
188 {
189 	struct mount *mp;
190 	struct nameidata nd;
191 	int error;
192 	bool mp_busy;
193 
194 	AUDIT_ARG_CMD(uap->cmd);
195 	AUDIT_ARG_UID(uap->uid);
196 	if (!prison_allow(td->td_ucred, PR_ALLOW_QUOTAS))
197 		return (EPERM);
198 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, UIO_USERSPACE,
199 	    uap->path);
200 	if ((error = namei(&nd)) != 0)
201 		return (error);
202 	NDFREE_PNBUF(&nd);
203 	mp = nd.ni_vp->v_mount;
204 	vfs_ref(mp);
205 	vput(nd.ni_vp);
206 	error = vfs_busy(mp, 0);
207 	if (error != 0) {
208 		vfs_rel(mp);
209 		return (error);
210 	}
211 	mp_busy = true;
212 	error = VFS_QUOTACTL(mp, uap->cmd, uap->uid, uap->arg, &mp_busy);
213 
214 	/*
215 	 * Since quota on/off operations typically need to open quota
216 	 * files, the implementation may need to unbusy the mount point
217 	 * before calling into namei.  Otherwise, unmount might be
218 	 * started between two vfs_busy() invocations (first is ours,
219 	 * second is from mount point cross-walk code in lookup()),
220 	 * causing deadlock.
221 	 *
222 	 * Avoid unbusying mp if the implementation indicates it has
223 	 * already done so.
224 	 */
225 	if (mp_busy)
226 		vfs_unbusy(mp);
227 	vfs_rel(mp);
228 	return (error);
229 }
230 
231 /*
232  * Used by statfs conversion routines to scale the block size up if
233  * necessary so that all of the block counts are <= 'max_size'.  Note
234  * that 'max_size' should be a bitmask, i.e. 2^n - 1 for some non-zero
235  * value of 'n'.
236  */
237 void
statfs_scale_blocks(struct statfs * sf,long max_size)238 statfs_scale_blocks(struct statfs *sf, long max_size)
239 {
240 	uint64_t count;
241 	int shift;
242 
243 	KASSERT(powerof2(max_size + 1), ("%s: invalid max_size", __func__));
244 
245 	/*
246 	 * Attempt to scale the block counts to give a more accurate
247 	 * overview to userland of the ratio of free space to used
248 	 * space.  To do this, find the largest block count and compute
249 	 * a divisor that lets it fit into a signed integer <= max_size.
250 	 */
251 	if (sf->f_bavail < 0)
252 		count = -sf->f_bavail;
253 	else
254 		count = sf->f_bavail;
255 	count = MAX(sf->f_blocks, MAX(sf->f_bfree, count));
256 	if (count <= max_size)
257 		return;
258 
259 	count >>= flsl(max_size);
260 	shift = 0;
261 	while (count > 0) {
262 		shift++;
263 		count >>=1;
264 	}
265 
266 	sf->f_bsize <<= shift;
267 	sf->f_blocks >>= shift;
268 	sf->f_bfree >>= shift;
269 	sf->f_bavail >>= shift;
270 }
271 
272 static int
kern_do_statfs(struct thread * td,struct mount * mp,struct statfs * buf)273 kern_do_statfs(struct thread *td, struct mount *mp, struct statfs *buf)
274 {
275 	int error;
276 
277 	if (mp == NULL)
278 		return (EBADF);
279 	error = vfs_busy(mp, 0);
280 	vfs_rel(mp);
281 	if (error != 0)
282 		return (error);
283 #ifdef MAC
284 	error = mac_mount_check_stat(td->td_ucred, mp);
285 	if (error != 0)
286 		goto out;
287 #endif
288 	error = VFS_STATFS(mp, buf);
289 	if (error != 0)
290 		goto out;
291 	if (priv_check_cred_vfs_generation(td->td_ucred)) {
292 		buf->f_fsid.val[0] = buf->f_fsid.val[1] = 0;
293 		prison_enforce_statfs(td->td_ucred, mp, buf);
294 	}
295 out:
296 	vfs_unbusy(mp);
297 	return (error);
298 }
299 
300 /*
301  * Get filesystem statistics.
302  */
303 #ifndef _SYS_SYSPROTO_H_
304 struct statfs_args {
305 	char *path;
306 	struct statfs *buf;
307 };
308 #endif
309 int
sys_statfs(struct thread * td,struct statfs_args * uap)310 sys_statfs(struct thread *td, struct statfs_args *uap)
311 {
312 	struct statfs *sfp;
313 	int error;
314 
315 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
316 	error = kern_statfs(td, uap->path, UIO_USERSPACE, sfp);
317 	if (error == 0)
318 		error = copyout(sfp, uap->buf, sizeof(struct statfs));
319 	free(sfp, M_STATFS);
320 	return (error);
321 }
322 
323 int
kern_statfs(struct thread * td,const char * path,enum uio_seg pathseg,struct statfs * buf)324 kern_statfs(struct thread *td, const char *path, enum uio_seg pathseg,
325     struct statfs *buf)
326 {
327 	struct mount *mp;
328 	struct nameidata nd;
329 	int error;
330 
331 	NDINIT(&nd, LOOKUP, FOLLOW | AUDITVNODE1, pathseg, path);
332 	error = namei(&nd);
333 	if (error != 0)
334 		return (error);
335 	NDFREE_PNBUF(&nd);
336 	mp = vfs_ref_from_vp(nd.ni_vp);
337 	vrele(nd.ni_vp);
338 	return (kern_do_statfs(td, mp, buf));
339 }
340 
341 /*
342  * Get filesystem statistics.
343  */
344 #ifndef _SYS_SYSPROTO_H_
345 struct fstatfs_args {
346 	int fd;
347 	struct statfs *buf;
348 };
349 #endif
350 int
sys_fstatfs(struct thread * td,struct fstatfs_args * uap)351 sys_fstatfs(struct thread *td, struct fstatfs_args *uap)
352 {
353 	struct statfs *sfp;
354 	int error;
355 
356 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
357 	error = kern_fstatfs(td, uap->fd, sfp);
358 	if (error == 0)
359 		error = copyout(sfp, uap->buf, sizeof(struct statfs));
360 	free(sfp, M_STATFS);
361 	return (error);
362 }
363 
364 int
kern_fstatfs(struct thread * td,int fd,struct statfs * buf)365 kern_fstatfs(struct thread *td, int fd, struct statfs *buf)
366 {
367 	struct file *fp;
368 	struct mount *mp;
369 	struct vnode *vp;
370 	int error;
371 
372 	AUDIT_ARG_FD(fd);
373 	error = getvnode_path(td, fd, &cap_fstatfs_rights, NULL, &fp);
374 	if (error != 0)
375 		return (error);
376 	vp = fp->f_vnode;
377 #ifdef AUDIT
378 	if (AUDITING_TD(td)) {
379 		vn_lock(vp, LK_SHARED | LK_RETRY);
380 		AUDIT_ARG_VNODE1(vp);
381 		VOP_UNLOCK(vp);
382 	}
383 #endif
384 	mp = vfs_ref_from_vp(vp);
385 	fdrop(fp, td);
386 	return (kern_do_statfs(td, mp, buf));
387 }
388 
389 /*
390  * Get statistics on all filesystems.
391  */
392 #ifndef _SYS_SYSPROTO_H_
393 struct getfsstat_args {
394 	struct statfs *buf;
395 	long bufsize;
396 	int mode;
397 };
398 #endif
399 int
sys_getfsstat(struct thread * td,struct getfsstat_args * uap)400 sys_getfsstat(struct thread *td, struct getfsstat_args *uap)
401 {
402 	size_t count;
403 	int error;
404 
405 	if (uap->bufsize < 0 || uap->bufsize > SIZE_MAX)
406 		return (EINVAL);
407 	error = kern_getfsstat(td, &uap->buf, uap->bufsize, &count,
408 	    UIO_USERSPACE, uap->mode);
409 	if (error == 0)
410 		td->td_retval[0] = count;
411 	return (error);
412 }
413 
414 /*
415  * If (bufsize > 0 && bufseg == UIO_SYSSPACE)
416  *	The caller is responsible for freeing memory which will be allocated
417  *	in '*buf'.
418  */
419 int
kern_getfsstat(struct thread * td,struct statfs ** buf,size_t bufsize,size_t * countp,enum uio_seg bufseg,int mode)420 kern_getfsstat(struct thread *td, struct statfs **buf, size_t bufsize,
421     size_t *countp, enum uio_seg bufseg, int mode)
422 {
423 	struct mount *mp, *nmp;
424 	struct statfs *sfsp, *sp, *sptmp, *tofree;
425 	size_t count, maxcount;
426 	int error;
427 
428 	switch (mode) {
429 	case MNT_WAIT:
430 	case MNT_NOWAIT:
431 		break;
432 	default:
433 		if (bufseg == UIO_SYSSPACE)
434 			*buf = NULL;
435 		return (EINVAL);
436 	}
437 restart:
438 	maxcount = bufsize / sizeof(struct statfs);
439 	if (bufsize == 0) {
440 		sfsp = NULL;
441 		tofree = NULL;
442 	} else if (bufseg == UIO_USERSPACE) {
443 		sfsp = *buf;
444 		tofree = NULL;
445 	} else /* if (bufseg == UIO_SYSSPACE) */ {
446 		count = 0;
447 		mtx_lock(&mountlist_mtx);
448 		TAILQ_FOREACH(mp, &mountlist, mnt_list) {
449 			count++;
450 		}
451 		mtx_unlock(&mountlist_mtx);
452 		if (maxcount > count)
453 			maxcount = count;
454 		tofree = sfsp = *buf = malloc(maxcount * sizeof(struct statfs),
455 		    M_STATFS, M_WAITOK);
456 	}
457 
458 	count = 0;
459 
460 	/*
461 	 * If there is no target buffer they only want the count.
462 	 *
463 	 * This could be TAILQ_FOREACH but it is open-coded to match the original
464 	 * code below.
465 	 */
466 	if (sfsp == NULL) {
467 		mtx_lock(&mountlist_mtx);
468 		for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
469 			if (prison_canseemount(td->td_ucred, mp) != 0) {
470 				nmp = TAILQ_NEXT(mp, mnt_list);
471 				continue;
472 			}
473 #ifdef MAC
474 			if (mac_mount_check_stat(td->td_ucred, mp) != 0) {
475 				nmp = TAILQ_NEXT(mp, mnt_list);
476 				continue;
477 			}
478 #endif
479 			count++;
480 			nmp = TAILQ_NEXT(mp, mnt_list);
481 		}
482 		mtx_unlock(&mountlist_mtx);
483 		*countp = count;
484 		return (0);
485 	}
486 
487 	/*
488 	 * They want the entire thing.
489 	 *
490 	 * Short-circuit the corner case of no room for anything, avoids
491 	 * relocking below.
492 	 */
493 	if (maxcount < 1) {
494 		goto out;
495 	}
496 
497 	mtx_lock(&mountlist_mtx);
498 	for (mp = TAILQ_FIRST(&mountlist); mp != NULL; mp = nmp) {
499 		if (prison_canseemount(td->td_ucred, mp) != 0) {
500 			nmp = TAILQ_NEXT(mp, mnt_list);
501 			continue;
502 		}
503 #ifdef MAC
504 		if (mac_mount_check_stat(td->td_ucred, mp) != 0) {
505 			nmp = TAILQ_NEXT(mp, mnt_list);
506 			continue;
507 		}
508 #endif
509 		if (mode == MNT_WAIT) {
510 			if (vfs_busy(mp, MBF_MNTLSTLOCK) != 0) {
511 				/*
512 				 * If vfs_busy() failed, and MBF_NOWAIT
513 				 * wasn't passed, then the mp is gone.
514 				 * Furthermore, because of MBF_MNTLSTLOCK,
515 				 * the mountlist_mtx was dropped.  We have
516 				 * no other choice than to start over.
517 				 */
518 				mtx_unlock(&mountlist_mtx);
519 				free(tofree, M_STATFS);
520 				goto restart;
521 			}
522 		} else {
523 			if (vfs_busy(mp, MBF_NOWAIT | MBF_MNTLSTLOCK) != 0) {
524 				nmp = TAILQ_NEXT(mp, mnt_list);
525 				continue;
526 			}
527 		}
528 		sp = &mp->mnt_stat;
529 		/*
530 		 * If MNT_NOWAIT is specified, do not refresh
531 		 * the fsstat cache.
532 		 */
533 		if (mode != MNT_NOWAIT) {
534 			error = VFS_STATFS(mp, sp);
535 			if (error != 0) {
536 				mtx_lock(&mountlist_mtx);
537 				nmp = TAILQ_NEXT(mp, mnt_list);
538 				vfs_unbusy(mp);
539 				continue;
540 			}
541 		}
542 		if (priv_check_cred_vfs_generation(td->td_ucred)) {
543 			sptmp = malloc(sizeof(struct statfs), M_STATFS,
544 			    M_WAITOK);
545 			*sptmp = *sp;
546 			sptmp->f_fsid.val[0] = sptmp->f_fsid.val[1] = 0;
547 			prison_enforce_statfs(td->td_ucred, mp, sptmp);
548 			sp = sptmp;
549 		} else
550 			sptmp = NULL;
551 		if (bufseg == UIO_SYSSPACE) {
552 			bcopy(sp, sfsp, sizeof(*sp));
553 			free(sptmp, M_STATFS);
554 		} else /* if (bufseg == UIO_USERSPACE) */ {
555 			error = copyout(sp, sfsp, sizeof(*sp));
556 			free(sptmp, M_STATFS);
557 			if (error != 0) {
558 				vfs_unbusy(mp);
559 				return (error);
560 			}
561 		}
562 		sfsp++;
563 		count++;
564 
565 		if (count == maxcount) {
566 			vfs_unbusy(mp);
567 			goto out;
568 		}
569 
570 		mtx_lock(&mountlist_mtx);
571 		nmp = TAILQ_NEXT(mp, mnt_list);
572 		vfs_unbusy(mp);
573 	}
574 	mtx_unlock(&mountlist_mtx);
575 out:
576 	*countp = count;
577 	return (0);
578 }
579 
580 #ifdef COMPAT_FREEBSD4
581 /*
582  * Get old format filesystem statistics.
583  */
584 static void freebsd4_cvtstatfs(struct statfs *, struct ostatfs *);
585 
586 #ifndef _SYS_SYSPROTO_H_
587 struct freebsd4_statfs_args {
588 	char *path;
589 	struct ostatfs *buf;
590 };
591 #endif
592 int
freebsd4_statfs(struct thread * td,struct freebsd4_statfs_args * uap)593 freebsd4_statfs(struct thread *td, struct freebsd4_statfs_args *uap)
594 {
595 	struct ostatfs osb;
596 	struct statfs *sfp;
597 	int error;
598 
599 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
600 	error = kern_statfs(td, uap->path, UIO_USERSPACE, sfp);
601 	if (error == 0) {
602 		freebsd4_cvtstatfs(sfp, &osb);
603 		error = copyout(&osb, uap->buf, sizeof(osb));
604 	}
605 	free(sfp, M_STATFS);
606 	return (error);
607 }
608 
609 /*
610  * Get filesystem statistics.
611  */
612 #ifndef _SYS_SYSPROTO_H_
613 struct freebsd4_fstatfs_args {
614 	int fd;
615 	struct ostatfs *buf;
616 };
617 #endif
618 int
freebsd4_fstatfs(struct thread * td,struct freebsd4_fstatfs_args * uap)619 freebsd4_fstatfs(struct thread *td, struct freebsd4_fstatfs_args *uap)
620 {
621 	struct ostatfs osb;
622 	struct statfs *sfp;
623 	int error;
624 
625 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
626 	error = kern_fstatfs(td, uap->fd, sfp);
627 	if (error == 0) {
628 		freebsd4_cvtstatfs(sfp, &osb);
629 		error = copyout(&osb, uap->buf, sizeof(osb));
630 	}
631 	free(sfp, M_STATFS);
632 	return (error);
633 }
634 
635 /*
636  * Get statistics on all filesystems.
637  */
638 #ifndef _SYS_SYSPROTO_H_
639 struct freebsd4_getfsstat_args {
640 	struct ostatfs *buf;
641 	long bufsize;
642 	int mode;
643 };
644 #endif
645 int
freebsd4_getfsstat(struct thread * td,struct freebsd4_getfsstat_args * uap)646 freebsd4_getfsstat(struct thread *td, struct freebsd4_getfsstat_args *uap)
647 {
648 	struct statfs *buf, *sp;
649 	struct ostatfs osb;
650 	size_t count, size;
651 	int error;
652 
653 	if (uap->bufsize < 0)
654 		return (EINVAL);
655 	count = uap->bufsize / sizeof(struct ostatfs);
656 	if (count > SIZE_MAX / sizeof(struct statfs))
657 		return (EINVAL);
658 	size = count * sizeof(struct statfs);
659 	error = kern_getfsstat(td, &buf, size, &count, UIO_SYSSPACE,
660 	    uap->mode);
661 	if (error == 0)
662 		td->td_retval[0] = count;
663 	if (size != 0) {
664 		sp = buf;
665 		while (count != 0 && error == 0) {
666 			freebsd4_cvtstatfs(sp, &osb);
667 			error = copyout(&osb, uap->buf, sizeof(osb));
668 			sp++;
669 			uap->buf++;
670 			count--;
671 		}
672 		free(buf, M_STATFS);
673 	}
674 	return (error);
675 }
676 
677 /*
678  * Implement fstatfs() for (NFS) file handles.
679  */
680 #ifndef _SYS_SYSPROTO_H_
681 struct freebsd4_fhstatfs_args {
682 	struct fhandle *u_fhp;
683 	struct ostatfs *buf;
684 };
685 #endif
686 int
freebsd4_fhstatfs(struct thread * td,struct freebsd4_fhstatfs_args * uap)687 freebsd4_fhstatfs(struct thread *td, struct freebsd4_fhstatfs_args *uap)
688 {
689 	struct ostatfs osb;
690 	struct statfs *sfp;
691 	fhandle_t fh;
692 	int error;
693 
694 	error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t));
695 	if (error != 0)
696 		return (error);
697 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
698 	error = kern_fhstatfs(td, fh, sfp);
699 	if (error == 0) {
700 		freebsd4_cvtstatfs(sfp, &osb);
701 		error = copyout(&osb, uap->buf, sizeof(osb));
702 	}
703 	free(sfp, M_STATFS);
704 	return (error);
705 }
706 
707 /*
708  * Convert a new format statfs structure to an old format statfs structure.
709  */
710 static void
freebsd4_cvtstatfs(struct statfs * nsp,struct ostatfs * osp)711 freebsd4_cvtstatfs(struct statfs *nsp, struct ostatfs *osp)
712 {
713 
714 	statfs_scale_blocks(nsp, LONG_MAX);
715 	bzero(osp, sizeof(*osp));
716 	osp->f_bsize = nsp->f_bsize;
717 	osp->f_iosize = MIN(nsp->f_iosize, LONG_MAX);
718 	osp->f_blocks = nsp->f_blocks;
719 	osp->f_bfree = nsp->f_bfree;
720 	osp->f_bavail = nsp->f_bavail;
721 	osp->f_files = MIN(nsp->f_files, LONG_MAX);
722 	osp->f_ffree = MIN(nsp->f_ffree, LONG_MAX);
723 	osp->f_owner = nsp->f_owner;
724 	osp->f_type = nsp->f_type;
725 	osp->f_flags = nsp->f_flags;
726 	osp->f_syncwrites = MIN(nsp->f_syncwrites, LONG_MAX);
727 	osp->f_asyncwrites = MIN(nsp->f_asyncwrites, LONG_MAX);
728 	osp->f_syncreads = MIN(nsp->f_syncreads, LONG_MAX);
729 	osp->f_asyncreads = MIN(nsp->f_asyncreads, LONG_MAX);
730 	strlcpy(osp->f_fstypename, nsp->f_fstypename,
731 	    MIN(MFSNAMELEN, OMFSNAMELEN));
732 	strlcpy(osp->f_mntonname, nsp->f_mntonname,
733 	    MIN(MNAMELEN, OMNAMELEN));
734 	strlcpy(osp->f_mntfromname, nsp->f_mntfromname,
735 	    MIN(MNAMELEN, OMNAMELEN));
736 	osp->f_fsid = nsp->f_fsid;
737 }
738 #endif /* COMPAT_FREEBSD4 */
739 
740 #if defined(COMPAT_FREEBSD11)
741 /*
742  * Get old format filesystem statistics.
743  */
744 static void freebsd11_cvtstatfs(struct statfs *, struct freebsd11_statfs *);
745 
746 int
freebsd11_statfs(struct thread * td,struct freebsd11_statfs_args * uap)747 freebsd11_statfs(struct thread *td, struct freebsd11_statfs_args *uap)
748 {
749 	struct freebsd11_statfs osb;
750 	struct statfs *sfp;
751 	int error;
752 
753 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
754 	error = kern_statfs(td, uap->path, UIO_USERSPACE, sfp);
755 	if (error == 0) {
756 		freebsd11_cvtstatfs(sfp, &osb);
757 		error = copyout(&osb, uap->buf, sizeof(osb));
758 	}
759 	free(sfp, M_STATFS);
760 	return (error);
761 }
762 
763 /*
764  * Get filesystem statistics.
765  */
766 int
freebsd11_fstatfs(struct thread * td,struct freebsd11_fstatfs_args * uap)767 freebsd11_fstatfs(struct thread *td, struct freebsd11_fstatfs_args *uap)
768 {
769 	struct freebsd11_statfs osb;
770 	struct statfs *sfp;
771 	int error;
772 
773 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
774 	error = kern_fstatfs(td, uap->fd, sfp);
775 	if (error == 0) {
776 		freebsd11_cvtstatfs(sfp, &osb);
777 		error = copyout(&osb, uap->buf, sizeof(osb));
778 	}
779 	free(sfp, M_STATFS);
780 	return (error);
781 }
782 
783 /*
784  * Get statistics on all filesystems.
785  */
786 int
freebsd11_getfsstat(struct thread * td,struct freebsd11_getfsstat_args * uap)787 freebsd11_getfsstat(struct thread *td, struct freebsd11_getfsstat_args *uap)
788 {
789 	return (kern_freebsd11_getfsstat(td, uap->buf, uap->bufsize, uap->mode));
790 }
791 
792 int
kern_freebsd11_getfsstat(struct thread * td,struct freebsd11_statfs * ubuf,long bufsize,int mode)793 kern_freebsd11_getfsstat(struct thread *td, struct freebsd11_statfs * ubuf,
794     long bufsize, int mode)
795 {
796 	struct freebsd11_statfs osb;
797 	struct statfs *buf, *sp;
798 	size_t count, size;
799 	int error;
800 
801 	if (bufsize < 0)
802 		return (EINVAL);
803 
804 	count = bufsize / sizeof(struct ostatfs);
805 	size = count * sizeof(struct statfs);
806 	error = kern_getfsstat(td, &buf, size, &count, UIO_SYSSPACE, mode);
807 	if (error == 0)
808 		td->td_retval[0] = count;
809 	if (size > 0) {
810 		sp = buf;
811 		while (count > 0 && error == 0) {
812 			freebsd11_cvtstatfs(sp, &osb);
813 			error = copyout(&osb, ubuf, sizeof(osb));
814 			sp++;
815 			ubuf++;
816 			count--;
817 		}
818 		free(buf, M_STATFS);
819 	}
820 	return (error);
821 }
822 
823 /*
824  * Implement fstatfs() for (NFS) file handles.
825  */
826 int
freebsd11_fhstatfs(struct thread * td,struct freebsd11_fhstatfs_args * uap)827 freebsd11_fhstatfs(struct thread *td, struct freebsd11_fhstatfs_args *uap)
828 {
829 	struct freebsd11_statfs osb;
830 	struct statfs *sfp;
831 	fhandle_t fh;
832 	int error;
833 
834 	error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t));
835 	if (error)
836 		return (error);
837 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
838 	error = kern_fhstatfs(td, fh, sfp);
839 	if (error == 0) {
840 		freebsd11_cvtstatfs(sfp, &osb);
841 		error = copyout(&osb, uap->buf, sizeof(osb));
842 	}
843 	free(sfp, M_STATFS);
844 	return (error);
845 }
846 
847 /*
848  * Convert a new format statfs structure to an old format statfs structure.
849  */
850 static void
freebsd11_cvtstatfs(struct statfs * nsp,struct freebsd11_statfs * osp)851 freebsd11_cvtstatfs(struct statfs *nsp, struct freebsd11_statfs *osp)
852 {
853 
854 	bzero(osp, sizeof(*osp));
855 	osp->f_version = FREEBSD11_STATFS_VERSION;
856 	osp->f_type = nsp->f_type;
857 	osp->f_flags = nsp->f_flags;
858 	osp->f_bsize = nsp->f_bsize;
859 	osp->f_iosize = nsp->f_iosize;
860 	osp->f_blocks = nsp->f_blocks;
861 	osp->f_bfree = nsp->f_bfree;
862 	osp->f_bavail = nsp->f_bavail;
863 	osp->f_files = nsp->f_files;
864 	osp->f_ffree = nsp->f_ffree;
865 	osp->f_syncwrites = nsp->f_syncwrites;
866 	osp->f_asyncwrites = nsp->f_asyncwrites;
867 	osp->f_syncreads = nsp->f_syncreads;
868 	osp->f_asyncreads = nsp->f_asyncreads;
869 	osp->f_namemax = nsp->f_namemax;
870 	osp->f_owner = nsp->f_owner;
871 	osp->f_fsid = nsp->f_fsid;
872 	strlcpy(osp->f_fstypename, nsp->f_fstypename,
873 	    MIN(MFSNAMELEN, sizeof(osp->f_fstypename)));
874 	strlcpy(osp->f_mntonname, nsp->f_mntonname,
875 	    MIN(MNAMELEN, sizeof(osp->f_mntonname)));
876 	strlcpy(osp->f_mntfromname, nsp->f_mntfromname,
877 	    MIN(MNAMELEN, sizeof(osp->f_mntfromname)));
878 }
879 #endif /* COMPAT_FREEBSD11 */
880 
881 /*
882  * Change current working directory to a given file descriptor.
883  */
884 #ifndef _SYS_SYSPROTO_H_
885 struct fchdir_args {
886 	int	fd;
887 };
888 #endif
889 int
sys_fchdir(struct thread * td,struct fchdir_args * uap)890 sys_fchdir(struct thread *td, struct fchdir_args *uap)
891 {
892 	struct vnode *vp, *tdp;
893 	struct mount *mp;
894 	struct file *fp;
895 	int error;
896 	uint8_t fdflags;
897 
898 	AUDIT_ARG_FD(uap->fd);
899 	error = getvnode_path(td, uap->fd, &cap_fchdir_rights, &fdflags,
900 	    &fp);
901 	if (error != 0)
902 		return (error);
903 	if ((fdflags & UF_RESOLVE_BENEATH) != 0) {
904 		fdrop(fp, td);
905 		return (ENOTCAPABLE);
906 	}
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 /*
974  * Takes locked vnode, unlocks it before returning.
975  */
976 static int
kern_chroot(struct thread * td,struct vnode * vp)977 kern_chroot(struct thread *td, struct vnode *vp)
978 {
979 	struct proc *p;
980 	int error;
981 
982 	error = priv_check(td, PRIV_VFS_CHROOT);
983 	if (error != 0) {
984 		p = td->td_proc;
985 		PROC_LOCK(p);
986 		if (unprivileged_chroot == 0 ||
987 		    (p->p_flag2 & P2_NO_NEW_PRIVS) == 0) {
988 			PROC_UNLOCK(p);
989 			goto e_vunlock;
990 		}
991 		PROC_UNLOCK(p);
992 	}
993 
994 	error = change_dir(vp, td);
995 	if (error != 0)
996 		goto e_vunlock;
997 #ifdef MAC
998 	error = mac_vnode_check_chroot(td->td_ucred, vp);
999 	if (error != 0)
1000 		goto e_vunlock;
1001 #endif
1002 	VOP_UNLOCK(vp);
1003 	error = pwd_chroot(td, vp);
1004 	vrele(vp);
1005 	return (error);
1006 e_vunlock:
1007 	vput(vp);
1008 	return (error);
1009 }
1010 
1011 /*
1012  * Change notion of root (``/'') directory.
1013  */
1014 #ifndef _SYS_SYSPROTO_H_
1015 struct chroot_args {
1016 	char	*path;
1017 };
1018 #endif
1019 int
sys_chroot(struct thread * td,struct chroot_args * uap)1020 sys_chroot(struct thread *td, struct chroot_args *uap)
1021 {
1022 	struct nameidata nd;
1023 	int error;
1024 
1025 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF | AUDITVNODE1,
1026 	    UIO_USERSPACE, uap->path);
1027 	error = namei(&nd);
1028 	if (error != 0)
1029 		return (error);
1030 	NDFREE_PNBUF(&nd);
1031 	error = kern_chroot(td, nd.ni_vp);
1032 	return (error);
1033 }
1034 
1035 /*
1036  * Change notion of root directory to a given file descriptor.
1037  */
1038 #ifndef _SYS_SYSPROTO_H_
1039 struct fchroot_args {
1040 	int	fd;
1041 };
1042 #endif
1043 int
sys_fchroot(struct thread * td,struct fchroot_args * uap)1044 sys_fchroot(struct thread *td, struct fchroot_args *uap)
1045 {
1046 	struct vnode *vp;
1047 	struct file *fp;
1048 	int error;
1049 	uint8_t fdflags;
1050 
1051 	error = getvnode_path(td, uap->fd, &cap_fchroot_rights, &fdflags, &fp);
1052 	if (error != 0)
1053 		return (error);
1054 	if ((fdflags & UF_RESOLVE_BENEATH) != 0) {
1055 		fdrop(fp, td);
1056 		return (ENOTCAPABLE);
1057 	}
1058 	vp = fp->f_vnode;
1059 	vrefact(vp);
1060 	fdrop(fp, td);
1061 	vn_lock(vp, LK_SHARED | LK_RETRY);
1062 	error = kern_chroot(td, vp);
1063 	return (error);
1064 }
1065 
1066 /*
1067  * Common routine for chroot and chdir.  Callers must provide a locked vnode
1068  * instance.
1069  */
1070 int
change_dir(struct vnode * vp,struct thread * td)1071 change_dir(struct vnode *vp, struct thread *td)
1072 {
1073 #ifdef MAC
1074 	int error;
1075 #endif
1076 
1077 	ASSERT_VOP_LOCKED(vp, "change_dir(): vp not locked");
1078 	if (vp->v_type != VDIR)
1079 		return (ENOTDIR);
1080 #ifdef MAC
1081 	error = mac_vnode_check_chdir(td->td_ucred, vp);
1082 	if (error != 0)
1083 		return (error);
1084 #endif
1085 	return (VOP_ACCESS(vp, VEXEC, td->td_ucred, td));
1086 }
1087 
1088 static __inline void
flags_to_rights(int flags,cap_rights_t * rightsp)1089 flags_to_rights(int flags, cap_rights_t *rightsp)
1090 {
1091 	if (flags & O_EXEC) {
1092 		cap_rights_set_one(rightsp, CAP_FEXECVE);
1093 		if (flags & O_PATH)
1094 			return;
1095 	} else {
1096 		switch ((flags & O_ACCMODE)) {
1097 		case O_RDONLY:
1098 			cap_rights_set_one(rightsp, CAP_READ);
1099 			break;
1100 		case O_RDWR:
1101 			cap_rights_set_one(rightsp, CAP_READ);
1102 			/* FALLTHROUGH */
1103 		case O_WRONLY:
1104 			cap_rights_set_one(rightsp, CAP_WRITE);
1105 			if (!(flags & (O_APPEND | O_TRUNC)))
1106 				cap_rights_set_one(rightsp, CAP_SEEK);
1107 			break;
1108 		}
1109 	}
1110 
1111 	if (flags & O_CREAT)
1112 		cap_rights_set_one(rightsp, CAP_CREATE);
1113 
1114 	if (flags & O_TRUNC)
1115 		cap_rights_set_one(rightsp, CAP_FTRUNCATE);
1116 
1117 	if (flags & (O_SYNC | O_FSYNC))
1118 		cap_rights_set_one(rightsp, CAP_FSYNC);
1119 
1120 	if (flags & (O_EXLOCK | O_SHLOCK))
1121 		cap_rights_set_one(rightsp, CAP_FLOCK);
1122 }
1123 
1124 /*
1125  * Check permissions, allocate an open file structure, and call the device
1126  * open routine if any.
1127  */
1128 #ifndef _SYS_SYSPROTO_H_
1129 struct open_args {
1130 	char	*path;
1131 	int	flags;
1132 	int	mode;
1133 };
1134 #endif
1135 int
sys_open(struct thread * td,struct open_args * uap)1136 sys_open(struct thread *td, struct open_args *uap)
1137 {
1138 
1139 	return (kern_openat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
1140 	    uap->flags, uap->mode));
1141 }
1142 
1143 #ifndef _SYS_SYSPROTO_H_
1144 struct openat_args {
1145 	int	fd;
1146 	char	*path;
1147 	int	flag;
1148 	int	mode;
1149 };
1150 #endif
1151 int
sys_openat(struct thread * td,struct openat_args * uap)1152 sys_openat(struct thread *td, struct openat_args *uap)
1153 {
1154 
1155 	AUDIT_ARG_FD(uap->fd);
1156 	return (kern_openat(td, uap->fd, uap->path, UIO_USERSPACE, uap->flag,
1157 	    uap->mode));
1158 }
1159 
1160 /*
1161  * Validate open(2) flags and convert access mode flags (O_RDONLY etc.) to their
1162  * in-kernel representations (FREAD etc.).
1163  */
1164 static int
openflags(int * flagsp)1165 openflags(int *flagsp)
1166 {
1167 	int flags;
1168 
1169 	/*
1170 	 * Only one of the O_EXEC, O_RDONLY, O_WRONLY and O_RDWR flags
1171 	 * may be specified.  On the other hand, for O_PATH any mode
1172 	 * except O_EXEC is ignored.
1173 	 */
1174 	flags = *flagsp;
1175 	if ((flags & O_PATH) != 0) {
1176 		flags &= ~O_ACCMODE;
1177 	} else if ((flags & O_EXEC) != 0) {
1178 		if ((flags & O_ACCMODE) != 0)
1179 			return (EINVAL);
1180 	} else if ((flags & O_ACCMODE) == O_ACCMODE) {
1181 		return (EINVAL);
1182 	} else {
1183 		flags = FFLAGS(flags);
1184 	}
1185 	*flagsp = flags;
1186 	return (0);
1187 }
1188 
1189 static void
finit_open(struct file * fp,struct vnode * vp,int flags)1190 finit_open(struct file *fp, struct vnode *vp, int flags)
1191 {
1192 	/*
1193 	 * Store the vnode, for any f_type. Typically, the vnode use count is
1194 	 * decremented by a direct call to vnops.fo_close() for files that
1195 	 * switched type.
1196 	 */
1197 	fp->f_vnode = vp;
1198 
1199 	/*
1200 	 * If the file wasn't claimed by devfs or fifofs, bind it to the normal
1201 	 * vnode operations here.
1202 	 */
1203 	if (fp->f_ops == &badfileops) {
1204 		KASSERT(vp->v_type != VFIFO || (flags & O_PATH) != 0,
1205 		    ("Unexpected fifo fp %p vp %p", fp, vp));
1206 		if ((flags & O_PATH) != 0) {
1207 			finit(fp, (flags & FMASK) | (fp->f_flag & FKQALLOWED),
1208 			    DTYPE_VNODE, NULL, &path_fileops);
1209 		} else {
1210 			finit_vnode(fp, flags, NULL, &vnops);
1211 		}
1212 	}
1213 }
1214 
1215 /*
1216  * If fpp != NULL, opened file is not installed into the file
1217  * descriptor table, instead it is returned in *fpp.  This is
1218  * incompatible with fdopen(), in which case we return EINVAL.
1219  */
1220 static int
openatfp(struct thread * td,int dirfd,const char * path,enum uio_seg pathseg,int flags,int mode,struct file ** fpp)1221 openatfp(struct thread *td, int dirfd, const char *path,
1222     enum uio_seg pathseg, int flags, int mode, struct file **fpp)
1223 {
1224 	struct proc *p;
1225 	struct filedesc *fdp;
1226 	struct pwddesc *pdp;
1227 	struct file *fp;
1228 	struct vnode *vp;
1229 	struct filecaps *fcaps;
1230 	struct nameidata nd;
1231 	cap_rights_t rights;
1232 	int cmode, error, indx;
1233 
1234 	indx = -1;
1235 	p = td->td_proc;
1236 	fdp = p->p_fd;
1237 	pdp = p->p_pd;
1238 
1239 	AUDIT_ARG_FFLAGS(flags);
1240 	AUDIT_ARG_MODE(mode);
1241 	cap_rights_init_one(&rights, CAP_LOOKUP);
1242 	flags_to_rights(flags, &rights);
1243 
1244 	error = openflags(&flags);
1245 	if (error != 0)
1246 		return (error);
1247 
1248 	/*
1249 	 * Allocate a file structure. The descriptor to reference it
1250 	 * is allocated and used by finstall_refed() below.
1251 	 */
1252 	error = falloc_noinstall(td, &fp);
1253 	if (error != 0)
1254 		return (error);
1255 	/* Set the flags early so the finit in devfs can pick them up. */
1256 	fp->f_flag = flags & FMASK;
1257 	cmode = ((mode & ~pdp->pd_cmask) & ALLPERMS) & ~S_ISTXT;
1258 	NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | AUDITVNODE1 | WANTIOCTLCAPS,
1259 	    pathseg, path, dirfd, &rights);
1260 	td->td_dupfd = -1;		/* XXX check for fdopen */
1261 	error = vn_open_cred(&nd, &flags, cmode, VN_OPEN_WANTIOCTLCAPS,
1262 	    td->td_ucred, fp);
1263 	if (error != 0) {
1264 		/*
1265 		 * If the vn_open replaced the method vector, something
1266 		 * wonderous happened deep below and we just pass it up
1267 		 * pretending we know what we do.
1268 		 */
1269 		if (error == ENXIO && fp->f_ops != &badfileops) {
1270 			MPASS((flags & O_PATH) == 0);
1271 			goto success;
1272 		}
1273 
1274 		/*
1275 		 * Handle special fdopen() case. bleh.
1276 		 *
1277 		 * Don't do this for relative (capability) lookups; we don't
1278 		 * understand exactly what would happen, and we don't think
1279 		 * that it ever should.
1280 		 */
1281 		if ((nd.ni_resflags & NIRES_STRICTREL) == 0 &&
1282 		    (error == ENODEV || error == ENXIO) &&
1283 		    td->td_dupfd >= 0) {
1284 			MPASS(fpp == NULL);
1285 			error = dupfdopen(td, fdp, td->td_dupfd, flags, error,
1286 			    &indx);
1287 			if (error == 0)
1288 				goto success;
1289 		}
1290 
1291 		goto bad;
1292 	}
1293 	td->td_dupfd = 0;
1294 	NDFREE_PNBUF(&nd);
1295 	vp = nd.ni_vp;
1296 
1297 	finit_open(fp, vp, flags);
1298 	VOP_UNLOCK(vp);
1299 	if (flags & O_TRUNC) {
1300 		error = fo_truncate(fp, 0, td->td_ucred, td);
1301 		if (error != 0)
1302 			goto bad;
1303 	}
1304 success:
1305 	if (fpp != NULL) {
1306 		MPASS(error == 0);
1307 		NDFREE_IOCTLCAPS(&nd);
1308 		*fpp = fp;
1309 		return (0);
1310 	}
1311 
1312 	/*
1313 	 * If we haven't already installed the FD (for dupfdopen), do so now.
1314 	 */
1315 	if (indx == -1) {
1316 #ifdef CAPABILITIES
1317 		if ((nd.ni_resflags & NIRES_STRICTREL) != 0)
1318 			fcaps = &nd.ni_filecaps;
1319 		else
1320 #endif
1321 			fcaps = NULL;
1322 		if ((nd.ni_resflags & NIRES_BENEATH) != 0)
1323 			flags |= O_RESOLVE_BENEATH;
1324 		else
1325 			flags &= ~O_RESOLVE_BENEATH;
1326 		error = finstall_refed(td, fp, &indx, flags, fcaps);
1327 		/* On success finstall_refed() consumes fcaps. */
1328 		if (error != 0) {
1329 			goto bad;
1330 		}
1331 	} else {
1332 		NDFREE_IOCTLCAPS(&nd);
1333 		falloc_abort(td, fp);
1334 	}
1335 
1336 	td->td_retval[0] = indx;
1337 	return (0);
1338 bad:
1339 	KASSERT(indx == -1, ("indx=%d, should be -1", indx));
1340 	NDFREE_IOCTLCAPS(&nd);
1341 	falloc_abort(td, fp);
1342 	return (error);
1343 }
1344 
1345 int
kern_openat(struct thread * td,int dirfd,const char * path,enum uio_seg pathseg,int flags,int mode)1346 kern_openat(struct thread *td, int dirfd, const char *path,
1347     enum uio_seg pathseg, int flags, int mode)
1348 {
1349 	return (openatfp(td, dirfd, path, pathseg, flags, mode, NULL));
1350 }
1351 
1352 int
kern_openatfp(struct thread * td,int dirfd,const char * path,enum uio_seg pathseg,int flags,int mode,struct file ** fpp)1353 kern_openatfp(struct thread *td, int dirfd, const char *path,
1354     enum uio_seg pathseg, int flags, int mode, struct file **fpp)
1355 {
1356 	int error, old_dupfd;
1357 
1358 	old_dupfd = td->td_dupfd;
1359 	td->td_dupfd = -1;
1360 	error = openatfp(td, dirfd, path, pathseg, flags, mode, fpp);
1361 	td->td_dupfd = old_dupfd;
1362 	return (error);
1363 }
1364 
1365 #ifdef COMPAT_43
1366 /*
1367  * Create a file.
1368  */
1369 #ifndef _SYS_SYSPROTO_H_
1370 struct ocreat_args {
1371 	char	*path;
1372 	int	mode;
1373 };
1374 #endif
1375 int
ocreat(struct thread * td,struct ocreat_args * uap)1376 ocreat(struct thread *td, struct ocreat_args *uap)
1377 {
1378 
1379 	return (kern_openat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
1380 	    O_WRONLY | O_CREAT | O_TRUNC, uap->mode));
1381 }
1382 #endif /* COMPAT_43 */
1383 
1384 /*
1385  * Create a special file.
1386  */
1387 #ifndef _SYS_SYSPROTO_H_
1388 struct mknodat_args {
1389 	int	fd;
1390 	char	*path;
1391 	mode_t	mode;
1392 	dev_t	dev;
1393 };
1394 #endif
1395 int
sys_mknodat(struct thread * td,struct mknodat_args * uap)1396 sys_mknodat(struct thread *td, struct mknodat_args *uap)
1397 {
1398 
1399 	return (kern_mknodat(td, uap->fd, uap->path, UIO_USERSPACE, uap->mode,
1400 	    uap->dev));
1401 }
1402 
1403 #if defined(COMPAT_FREEBSD11)
1404 int
freebsd11_mknod(struct thread * td,struct freebsd11_mknod_args * uap)1405 freebsd11_mknod(struct thread *td,
1406     struct freebsd11_mknod_args *uap)
1407 {
1408 
1409 	return (kern_mknodat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
1410 	    uap->mode, uap->dev));
1411 }
1412 
1413 int
freebsd11_mknodat(struct thread * td,struct freebsd11_mknodat_args * uap)1414 freebsd11_mknodat(struct thread *td,
1415     struct freebsd11_mknodat_args *uap)
1416 {
1417 
1418 	return (kern_mknodat(td, uap->fd, uap->path, UIO_USERSPACE, uap->mode,
1419 	    uap->dev));
1420 }
1421 #endif /* COMPAT_FREEBSD11 */
1422 
1423 int
kern_mknodat(struct thread * td,int fd,const char * path,enum uio_seg pathseg,int mode,dev_t dev)1424 kern_mknodat(struct thread *td, int fd, const char *path, enum uio_seg pathseg,
1425     int mode, dev_t dev)
1426 {
1427 	struct vnode *vp;
1428 	struct mount *mp;
1429 	struct vattr vattr;
1430 	struct nameidata nd;
1431 	int error, whiteout = 0;
1432 
1433 	AUDIT_ARG_MODE(mode);
1434 	AUDIT_ARG_DEV(dev);
1435 	switch (mode & S_IFMT) {
1436 	case S_IFCHR:
1437 	case S_IFBLK:
1438 		error = priv_check(td, PRIV_VFS_MKNOD_DEV);
1439 		if (error == 0 && dev == VNOVAL)
1440 			error = EINVAL;
1441 		break;
1442 	case S_IFWHT:
1443 		error = priv_check(td, PRIV_VFS_MKNOD_WHT);
1444 		break;
1445 	case S_IFIFO:
1446 		if (dev == 0)
1447 			return (kern_mkfifoat(td, fd, path, pathseg, mode));
1448 		/* FALLTHROUGH */
1449 	default:
1450 		error = EINVAL;
1451 		break;
1452 	}
1453 	if (error != 0)
1454 		return (error);
1455 	NDPREINIT(&nd);
1456 restart:
1457 	bwillwrite();
1458 	NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | AUDITVNODE1 | NOCACHE,
1459 	    pathseg, path, fd, &cap_mknodat_rights);
1460 	if ((error = namei(&nd)) != 0)
1461 		return (error);
1462 	vp = nd.ni_vp;
1463 	if (vp != NULL) {
1464 		NDFREE_PNBUF(&nd);
1465 		if (vp == nd.ni_dvp)
1466 			vrele(nd.ni_dvp);
1467 		else
1468 			vput(nd.ni_dvp);
1469 		vrele(vp);
1470 		return (EEXIST);
1471 	} else if ((vn_irflag_read(nd.ni_dvp) & VIRF_NAMEDDIR) != 0) {
1472 		NDFREE_PNBUF(&nd);
1473 		vput(nd.ni_dvp);
1474 		return (EINVAL);
1475 	} else {
1476 		VATTR_NULL(&vattr);
1477 		vattr.va_mode = (mode & ALLPERMS) &
1478 		    ~td->td_proc->p_pd->pd_cmask;
1479 		vattr.va_rdev = dev;
1480 		whiteout = 0;
1481 
1482 		switch (mode & S_IFMT) {
1483 		case S_IFCHR:
1484 			vattr.va_type = VCHR;
1485 			break;
1486 		case S_IFBLK:
1487 			vattr.va_type = VBLK;
1488 			break;
1489 		case S_IFWHT:
1490 			whiteout = 1;
1491 			break;
1492 		default:
1493 			panic("kern_mknod: invalid mode");
1494 		}
1495 	}
1496 	if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
1497 		NDFREE_PNBUF(&nd);
1498 		vput(nd.ni_dvp);
1499 		if ((error = vn_start_write(NULL, &mp, V_XSLEEP | V_PCATCH)) != 0)
1500 			return (error);
1501 		goto restart;
1502 	}
1503 #ifdef MAC
1504 	if (error == 0 && !whiteout)
1505 		error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp,
1506 		    &nd.ni_cnd, &vattr);
1507 #endif
1508 	if (error == 0) {
1509 		if (whiteout)
1510 			error = VOP_WHITEOUT(nd.ni_dvp, &nd.ni_cnd, CREATE);
1511 		else {
1512 			error = VOP_MKNOD(nd.ni_dvp, &nd.ni_vp,
1513 						&nd.ni_cnd, &vattr);
1514 		}
1515 	}
1516 	VOP_VPUT_PAIR(nd.ni_dvp, error == 0 && !whiteout ? &nd.ni_vp : NULL,
1517 	    true);
1518 	vn_finished_write(mp);
1519 	NDFREE_PNBUF(&nd);
1520 	if (error == ERELOOKUP)
1521 		goto restart;
1522 	return (error);
1523 }
1524 
1525 /*
1526  * Create a named pipe.
1527  */
1528 #ifndef _SYS_SYSPROTO_H_
1529 struct mkfifo_args {
1530 	char	*path;
1531 	int	mode;
1532 };
1533 #endif
1534 int
sys_mkfifo(struct thread * td,struct mkfifo_args * uap)1535 sys_mkfifo(struct thread *td, struct mkfifo_args *uap)
1536 {
1537 
1538 	return (kern_mkfifoat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
1539 	    uap->mode));
1540 }
1541 
1542 #ifndef _SYS_SYSPROTO_H_
1543 struct mkfifoat_args {
1544 	int	fd;
1545 	char	*path;
1546 	mode_t	mode;
1547 };
1548 #endif
1549 int
sys_mkfifoat(struct thread * td,struct mkfifoat_args * uap)1550 sys_mkfifoat(struct thread *td, struct mkfifoat_args *uap)
1551 {
1552 
1553 	return (kern_mkfifoat(td, uap->fd, uap->path, UIO_USERSPACE,
1554 	    uap->mode));
1555 }
1556 
1557 int
kern_mkfifoat(struct thread * td,int fd,const char * path,enum uio_seg pathseg,int mode)1558 kern_mkfifoat(struct thread *td, int fd, const char *path,
1559     enum uio_seg pathseg, int mode)
1560 {
1561 	struct mount *mp;
1562 	struct vattr vattr;
1563 	struct nameidata nd;
1564 	int error;
1565 
1566 	AUDIT_ARG_MODE(mode);
1567 	NDPREINIT(&nd);
1568 restart:
1569 	bwillwrite();
1570 	NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | AUDITVNODE1 | NOCACHE,
1571 	    pathseg, path, fd, &cap_mkfifoat_rights);
1572 	if ((error = namei(&nd)) != 0)
1573 		return (error);
1574 	if (nd.ni_vp != NULL) {
1575 		NDFREE_PNBUF(&nd);
1576 		if (nd.ni_vp == nd.ni_dvp)
1577 			vrele(nd.ni_dvp);
1578 		else
1579 			vput(nd.ni_dvp);
1580 		vrele(nd.ni_vp);
1581 		return (EEXIST);
1582 	}
1583 	if ((vn_irflag_read(nd.ni_dvp) & VIRF_NAMEDDIR) != 0) {
1584 		NDFREE_PNBUF(&nd);
1585 		vput(nd.ni_dvp);
1586 		return (EINVAL);
1587 	}
1588 	if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
1589 		NDFREE_PNBUF(&nd);
1590 		vput(nd.ni_dvp);
1591 		if ((error = vn_start_write(NULL, &mp, V_XSLEEP | V_PCATCH)) != 0)
1592 			return (error);
1593 		goto restart;
1594 	}
1595 	VATTR_NULL(&vattr);
1596 	vattr.va_type = VFIFO;
1597 	vattr.va_mode = (mode & ALLPERMS) & ~td->td_proc->p_pd->pd_cmask;
1598 #ifdef MAC
1599 	error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
1600 	    &vattr);
1601 	if (error != 0)
1602 		goto out;
1603 #endif
1604 	error = VOP_MKNOD(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
1605 #ifdef MAC
1606 out:
1607 #endif
1608 	VOP_VPUT_PAIR(nd.ni_dvp, error == 0 ? &nd.ni_vp : NULL, true);
1609 	vn_finished_write(mp);
1610 	NDFREE_PNBUF(&nd);
1611 	if (error == ERELOOKUP)
1612 		goto restart;
1613 	return (error);
1614 }
1615 
1616 /*
1617  * Make a hard file link.
1618  */
1619 #ifndef _SYS_SYSPROTO_H_
1620 struct link_args {
1621 	char	*path;
1622 	char	*link;
1623 };
1624 #endif
1625 int
sys_link(struct thread * td,struct link_args * uap)1626 sys_link(struct thread *td, struct link_args *uap)
1627 {
1628 
1629 	return (kern_linkat(td, AT_FDCWD, AT_FDCWD, uap->path, uap->link,
1630 	    UIO_USERSPACE, AT_SYMLINK_FOLLOW));
1631 }
1632 
1633 #ifndef _SYS_SYSPROTO_H_
1634 struct linkat_args {
1635 	int	fd1;
1636 	char	*path1;
1637 	int	fd2;
1638 	char	*path2;
1639 	int	flag;
1640 };
1641 #endif
1642 int
sys_linkat(struct thread * td,struct linkat_args * uap)1643 sys_linkat(struct thread *td, struct linkat_args *uap)
1644 {
1645 
1646 	return (kern_linkat(td, uap->fd1, uap->fd2, uap->path1, uap->path2,
1647 	    UIO_USERSPACE, uap->flag));
1648 }
1649 
1650 int hardlink_check_uid = 0;
1651 SYSCTL_INT(_security_bsd, OID_AUTO, hardlink_check_uid, CTLFLAG_RW,
1652     &hardlink_check_uid, 0,
1653     "Unprivileged processes cannot create hard links to files owned by other "
1654     "users");
1655 static int hardlink_check_gid = 0;
1656 SYSCTL_INT(_security_bsd, OID_AUTO, hardlink_check_gid, CTLFLAG_RW,
1657     &hardlink_check_gid, 0,
1658     "Unprivileged processes cannot create hard links to files owned by other "
1659     "groups");
1660 
1661 static int
can_hardlink(struct vnode * vp,struct ucred * cred)1662 can_hardlink(struct vnode *vp, struct ucred *cred)
1663 {
1664 	struct vattr va;
1665 	int error;
1666 
1667 	if (!hardlink_check_uid && !hardlink_check_gid)
1668 		return (0);
1669 
1670 	error = VOP_GETATTR(vp, &va, cred);
1671 	if (error != 0)
1672 		return (error);
1673 
1674 	if (hardlink_check_uid && cred->cr_uid != va.va_uid) {
1675 		error = priv_check_cred(cred, PRIV_VFS_LINK);
1676 		if (error != 0)
1677 			return (error);
1678 	}
1679 
1680 	if (hardlink_check_gid && !groupmember(va.va_gid, cred)) {
1681 		error = priv_check_cred(cred, PRIV_VFS_LINK);
1682 		if (error != 0)
1683 			return (error);
1684 	}
1685 
1686 	return (0);
1687 }
1688 
1689 int
kern_linkat(struct thread * td,int fd1,int fd2,const char * path1,const char * path2,enum uio_seg segflag,int flag)1690 kern_linkat(struct thread *td, int fd1, int fd2, const char *path1,
1691     const char *path2, enum uio_seg segflag, int flag)
1692 {
1693 	struct nameidata nd;
1694 	int error;
1695 
1696 	if ((flag & ~(AT_SYMLINK_FOLLOW | AT_RESOLVE_BENEATH |
1697 	    AT_EMPTY_PATH)) != 0)
1698 		return (EINVAL);
1699 
1700 	NDPREINIT(&nd);
1701 	do {
1702 		bwillwrite();
1703 		NDINIT_ATRIGHTS(&nd, LOOKUP, AUDITVNODE1 | at2cnpflags(flag,
1704 		    AT_SYMLINK_FOLLOW | AT_RESOLVE_BENEATH | AT_EMPTY_PATH),
1705 		    segflag, path1, fd1, &cap_linkat_source_rights);
1706 		if ((error = namei(&nd)) != 0)
1707 			return (error);
1708 		NDFREE_PNBUF(&nd);
1709 		if ((nd.ni_resflags & NIRES_EMPTYPATH) != 0) {
1710 			error = priv_check(td, PRIV_VFS_FHOPEN);
1711 			if (error != 0) {
1712 				vrele(nd.ni_vp);
1713 				return (error);
1714 			}
1715 		}
1716 		error = kern_linkat_vp(td, nd.ni_vp, fd2, path2, segflag);
1717 	} while (error ==  EAGAIN || error == ERELOOKUP);
1718 	return (error);
1719 }
1720 
1721 static int
kern_linkat_vp(struct thread * td,struct vnode * vp,int fd,const char * path,enum uio_seg segflag)1722 kern_linkat_vp(struct thread *td, struct vnode *vp, int fd, const char *path,
1723     enum uio_seg segflag)
1724 {
1725 	struct nameidata nd;
1726 	struct mount *mp;
1727 	int error;
1728 
1729 	if (vp->v_type == VDIR) {
1730 		vrele(vp);
1731 		return (EPERM);		/* POSIX */
1732 	}
1733 	if ((vn_irflag_read(vp) & (VIRF_NAMEDDIR | VIRF_NAMEDATTR)) != 0) {
1734 		vrele(vp);
1735 		return (EINVAL);
1736 	}
1737 	NDINIT_ATRIGHTS(&nd, CREATE,
1738 	    LOCKPARENT | AUDITVNODE2 | NOCACHE, segflag, path, fd,
1739 	    &cap_linkat_target_rights);
1740 	if ((error = namei(&nd)) == 0) {
1741 		if (nd.ni_vp != NULL) {
1742 			NDFREE_PNBUF(&nd);
1743 			if (nd.ni_dvp == nd.ni_vp)
1744 				vrele(nd.ni_dvp);
1745 			else
1746 				vput(nd.ni_dvp);
1747 			vrele(nd.ni_vp);
1748 			vrele(vp);
1749 			return (EEXIST);
1750 		} else if (nd.ni_dvp->v_mount != vp->v_mount) {
1751 			/*
1752 			 * Cross-device link.  No need to recheck
1753 			 * vp->v_type, since it cannot change, except
1754 			 * to VBAD.
1755 			 */
1756 			NDFREE_PNBUF(&nd);
1757 			vput(nd.ni_dvp);
1758 			vrele(vp);
1759 			return (EXDEV);
1760 		} else if (vn_lock(vp, LK_EXCLUSIVE) == 0) {
1761 			error = can_hardlink(vp, td->td_ucred);
1762 #ifdef MAC
1763 			if (error == 0)
1764 				error = mac_vnode_check_link(td->td_ucred,
1765 				    nd.ni_dvp, vp, &nd.ni_cnd);
1766 #endif
1767 			if (error != 0) {
1768 				vput(vp);
1769 				vput(nd.ni_dvp);
1770 				NDFREE_PNBUF(&nd);
1771 				return (error);
1772 			}
1773 			error = vn_start_write(vp, &mp, V_NOWAIT);
1774 			if (error != 0) {
1775 				vput(vp);
1776 				vput(nd.ni_dvp);
1777 				NDFREE_PNBUF(&nd);
1778 				error = vn_start_write(NULL, &mp,
1779 				    V_XSLEEP | V_PCATCH);
1780 				if (error != 0)
1781 					return (error);
1782 				return (EAGAIN);
1783 			}
1784 			error = VOP_LINK(nd.ni_dvp, vp, &nd.ni_cnd);
1785 			VOP_VPUT_PAIR(nd.ni_dvp, &vp, true);
1786 			vn_finished_write(mp);
1787 			NDFREE_PNBUF(&nd);
1788 			vp = NULL;
1789 		} else {
1790 			vput(nd.ni_dvp);
1791 			NDFREE_PNBUF(&nd);
1792 			vrele(vp);
1793 			return (EAGAIN);
1794 		}
1795 	}
1796 	if (vp != NULL)
1797 		vrele(vp);
1798 	return (error);
1799 }
1800 
1801 /*
1802  * Make a symbolic link.
1803  */
1804 #ifndef _SYS_SYSPROTO_H_
1805 struct symlink_args {
1806 	char	*path;
1807 	char	*link;
1808 };
1809 #endif
1810 int
sys_symlink(struct thread * td,struct symlink_args * uap)1811 sys_symlink(struct thread *td, struct symlink_args *uap)
1812 {
1813 
1814 	return (kern_symlinkat(td, uap->path, AT_FDCWD, uap->link,
1815 	    UIO_USERSPACE));
1816 }
1817 
1818 #ifndef _SYS_SYSPROTO_H_
1819 struct symlinkat_args {
1820 	char	*path;
1821 	int	fd;
1822 	char	*path2;
1823 };
1824 #endif
1825 int
sys_symlinkat(struct thread * td,struct symlinkat_args * uap)1826 sys_symlinkat(struct thread *td, struct symlinkat_args *uap)
1827 {
1828 
1829 	return (kern_symlinkat(td, uap->path1, uap->fd, uap->path2,
1830 	    UIO_USERSPACE));
1831 }
1832 
1833 int
kern_symlinkat(struct thread * td,const char * path1,int fd,const char * path2,enum uio_seg segflg)1834 kern_symlinkat(struct thread *td, const char *path1, int fd, const char *path2,
1835     enum uio_seg segflg)
1836 {
1837 	struct mount *mp;
1838 	struct vattr vattr;
1839 	const char *syspath;
1840 	char *tmppath;
1841 	struct nameidata nd;
1842 	int error;
1843 
1844 	if (segflg == UIO_SYSSPACE) {
1845 		syspath = path1;
1846 	} else {
1847 		tmppath = uma_zalloc(namei_zone, M_WAITOK);
1848 		if ((error = copyinstr(path1, tmppath, MAXPATHLEN, NULL)) != 0)
1849 			goto out;
1850 		syspath = tmppath;
1851 	}
1852 	AUDIT_ARG_TEXT(syspath);
1853 	NDPREINIT(&nd);
1854 restart:
1855 	bwillwrite();
1856 	NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | AUDITVNODE1 | NOCACHE, segflg,
1857 	    path2, fd, &cap_symlinkat_rights);
1858 	if ((error = namei(&nd)) != 0)
1859 		goto out;
1860 	if (nd.ni_vp) {
1861 		NDFREE_PNBUF(&nd);
1862 		if (nd.ni_vp == nd.ni_dvp)
1863 			vrele(nd.ni_dvp);
1864 		else
1865 			vput(nd.ni_dvp);
1866 		vrele(nd.ni_vp);
1867 		nd.ni_vp = NULL;
1868 		error = EEXIST;
1869 		goto out;
1870 	}
1871 	if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
1872 		NDFREE_PNBUF(&nd);
1873 		vput(nd.ni_dvp);
1874 		if ((error = vn_start_write(NULL, &mp, V_XSLEEP | V_PCATCH)) != 0)
1875 			goto out;
1876 		goto restart;
1877 	}
1878 	if ((vn_irflag_read(nd.ni_dvp) & VIRF_NAMEDDIR) != 0) {
1879 		error = EINVAL;
1880 		goto out;
1881 	}
1882 	VATTR_NULL(&vattr);
1883 	vattr.va_mode = ACCESSPERMS &~ td->td_proc->p_pd->pd_cmask;
1884 #ifdef MAC
1885 	vattr.va_type = VLNK;
1886 	error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
1887 	    &vattr);
1888 	if (error != 0)
1889 		goto out2;
1890 #endif
1891 	error = VOP_SYMLINK(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr, syspath);
1892 #ifdef MAC
1893 out2:
1894 #endif
1895 	VOP_VPUT_PAIR(nd.ni_dvp, error == 0 ? &nd.ni_vp : NULL, true);
1896 	vn_finished_write(mp);
1897 	NDFREE_PNBUF(&nd);
1898 	if (error == ERELOOKUP)
1899 		goto restart;
1900 out:
1901 	if (segflg != UIO_SYSSPACE)
1902 		uma_zfree(namei_zone, tmppath);
1903 	return (error);
1904 }
1905 
1906 /*
1907  * Delete a whiteout from the filesystem.
1908  */
1909 #ifndef _SYS_SYSPROTO_H_
1910 struct undelete_args {
1911 	char *path;
1912 };
1913 #endif
1914 int
sys_undelete(struct thread * td,struct undelete_args * uap)1915 sys_undelete(struct thread *td, struct undelete_args *uap)
1916 {
1917 	struct mount *mp;
1918 	struct nameidata nd;
1919 	int error;
1920 
1921 	NDPREINIT(&nd);
1922 restart:
1923 	bwillwrite();
1924 	NDINIT(&nd, DELETE, LOCKPARENT | DOWHITEOUT | AUDITVNODE1,
1925 	    UIO_USERSPACE, uap->path);
1926 	error = namei(&nd);
1927 	if (error != 0)
1928 		return (error);
1929 
1930 	if (nd.ni_vp != NULLVP || !(nd.ni_cnd.cn_flags & ISWHITEOUT)) {
1931 		NDFREE_PNBUF(&nd);
1932 		if (nd.ni_vp == nd.ni_dvp)
1933 			vrele(nd.ni_dvp);
1934 		else
1935 			vput(nd.ni_dvp);
1936 		if (nd.ni_vp)
1937 			vrele(nd.ni_vp);
1938 		return (EEXIST);
1939 	}
1940 	if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
1941 		NDFREE_PNBUF(&nd);
1942 		vput(nd.ni_dvp);
1943 		if ((error = vn_start_write(NULL, &mp, V_XSLEEP | V_PCATCH)) != 0)
1944 			return (error);
1945 		goto restart;
1946 	}
1947 	error = VOP_WHITEOUT(nd.ni_dvp, &nd.ni_cnd, DELETE);
1948 	NDFREE_PNBUF(&nd);
1949 	vput(nd.ni_dvp);
1950 	vn_finished_write(mp);
1951 	if (error == ERELOOKUP)
1952 		goto restart;
1953 	return (error);
1954 }
1955 
1956 /*
1957  * Delete a name from the filesystem.
1958  */
1959 #ifndef _SYS_SYSPROTO_H_
1960 struct unlink_args {
1961 	char	*path;
1962 };
1963 #endif
1964 int
sys_unlink(struct thread * td,struct unlink_args * uap)1965 sys_unlink(struct thread *td, struct unlink_args *uap)
1966 {
1967 
1968 	return (kern_funlinkat(td, AT_FDCWD, uap->path, FD_NONE, UIO_USERSPACE,
1969 	    0, 0));
1970 }
1971 
1972 static int
kern_funlinkat_ex(struct thread * td,int dfd,const char * path,int fd,int flag,enum uio_seg pathseg,ino_t oldinum)1973 kern_funlinkat_ex(struct thread *td, int dfd, const char *path, int fd,
1974     int flag, enum uio_seg pathseg, ino_t oldinum)
1975 {
1976 
1977 	if ((flag & ~(AT_REMOVEDIR | AT_RESOLVE_BENEATH)) != 0)
1978 		return (EINVAL);
1979 
1980 	if ((flag & AT_REMOVEDIR) != 0)
1981 		return (kern_frmdirat(td, dfd, path, fd, UIO_USERSPACE, 0));
1982 
1983 	return (kern_funlinkat(td, dfd, path, fd, UIO_USERSPACE, 0, 0));
1984 }
1985 
1986 #ifndef _SYS_SYSPROTO_H_
1987 struct unlinkat_args {
1988 	int	fd;
1989 	char	*path;
1990 	int	flag;
1991 };
1992 #endif
1993 int
sys_unlinkat(struct thread * td,struct unlinkat_args * uap)1994 sys_unlinkat(struct thread *td, struct unlinkat_args *uap)
1995 {
1996 
1997 	return (kern_funlinkat_ex(td, uap->fd, uap->path, FD_NONE, uap->flag,
1998 	    UIO_USERSPACE, 0));
1999 }
2000 
2001 #ifndef _SYS_SYSPROTO_H_
2002 struct funlinkat_args {
2003 	int		dfd;
2004 	const char	*path;
2005 	int		fd;
2006 	int		flag;
2007 };
2008 #endif
2009 int
sys_funlinkat(struct thread * td,struct funlinkat_args * uap)2010 sys_funlinkat(struct thread *td, struct funlinkat_args *uap)
2011 {
2012 
2013 	return (kern_funlinkat_ex(td, uap->dfd, uap->path, uap->fd, uap->flag,
2014 	    UIO_USERSPACE, 0));
2015 }
2016 
2017 int
kern_funlinkat(struct thread * td,int dfd,const char * path,int fd,enum uio_seg pathseg,int flag,ino_t oldinum)2018 kern_funlinkat(struct thread *td, int dfd, const char *path, int fd,
2019     enum uio_seg pathseg, int flag, ino_t oldinum)
2020 {
2021 	struct mount *mp;
2022 	struct file *fp;
2023 	struct vnode *vp;
2024 	struct nameidata nd;
2025 	struct stat sb;
2026 	int error;
2027 
2028 	fp = NULL;
2029 	if (fd != FD_NONE) {
2030 		error = getvnode_path(td, fd, &cap_no_rights, NULL, &fp);
2031 		if (error != 0)
2032 			return (error);
2033 	}
2034 
2035 	NDPREINIT(&nd);
2036 restart:
2037 	bwillwrite();
2038 	NDINIT_ATRIGHTS(&nd, DELETE, LOCKPARENT | LOCKLEAF | AUDITVNODE1 |
2039 	    at2cnpflags(flag, AT_RESOLVE_BENEATH),
2040 	    pathseg, path, dfd, &cap_unlinkat_rights);
2041 	if ((error = namei(&nd)) != 0) {
2042 		if (error == EINVAL)
2043 			error = EPERM;
2044 		goto fdout;
2045 	}
2046 	vp = nd.ni_vp;
2047 	if (vp->v_type == VDIR && oldinum == 0) {
2048 		error = EPERM;		/* POSIX */
2049 	} else if (oldinum != 0 &&
2050 	    ((error = VOP_STAT(vp, &sb, td->td_ucred, NOCRED)) == 0) &&
2051 	    sb.st_ino != oldinum) {
2052 		error = EIDRM;	/* Identifier removed */
2053 	} else if (fp != NULL && fp->f_vnode != vp) {
2054 		if (VN_IS_DOOMED(fp->f_vnode))
2055 			error = EBADF;
2056 		else
2057 			error = EDEADLK;
2058 	} else {
2059 		/*
2060 		 * The root of a mounted filesystem cannot be deleted.
2061 		 *
2062 		 * XXX: can this only be a VDIR case?
2063 		 */
2064 		if (vp->v_vflag & VV_ROOT)
2065 			error = EBUSY;
2066 	}
2067 	if (error == 0) {
2068 		if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
2069 			NDFREE_PNBUF(&nd);
2070 			vput(nd.ni_dvp);
2071 			if (vp == nd.ni_dvp)
2072 				vrele(vp);
2073 			else
2074 				vput(vp);
2075 			if ((error = vn_start_write(NULL, &mp,
2076 			    V_XSLEEP | V_PCATCH)) != 0) {
2077 				goto fdout;
2078 			}
2079 			goto restart;
2080 		}
2081 #ifdef MAC
2082 		error = mac_vnode_check_unlink(td->td_ucred, nd.ni_dvp, vp,
2083 		    &nd.ni_cnd);
2084 		if (error != 0)
2085 			goto out;
2086 #endif
2087 		error = VOP_REMOVE(nd.ni_dvp, vp, &nd.ni_cnd);
2088 #ifdef MAC
2089 out:
2090 #endif
2091 		vn_finished_write(mp);
2092 	}
2093 	NDFREE_PNBUF(&nd);
2094 	vput(nd.ni_dvp);
2095 	if (vp == nd.ni_dvp)
2096 		vrele(vp);
2097 	else
2098 		vput(vp);
2099 	if (error == ERELOOKUP)
2100 		goto restart;
2101 fdout:
2102 	if (fp != NULL)
2103 		fdrop(fp, td);
2104 	return (error);
2105 }
2106 
2107 /*
2108  * Reposition read/write file offset.
2109  */
2110 #ifndef _SYS_SYSPROTO_H_
2111 struct lseek_args {
2112 	int	fd;
2113 	int	pad;
2114 	off_t	offset;
2115 	int	whence;
2116 };
2117 #endif
2118 int
sys_lseek(struct thread * td,struct lseek_args * uap)2119 sys_lseek(struct thread *td, struct lseek_args *uap)
2120 {
2121 
2122 	return (kern_lseek(td, uap->fd, uap->offset, uap->whence));
2123 }
2124 
2125 int
kern_lseek(struct thread * td,int fd,off_t offset,int whence)2126 kern_lseek(struct thread *td, int fd, off_t offset, int whence)
2127 {
2128 	struct file *fp;
2129 	int error;
2130 
2131 	AUDIT_ARG_FD(fd);
2132 	error = fget(td, fd, &cap_seek_rights, &fp);
2133 	if (error != 0)
2134 		return (error);
2135 	error = (fp->f_ops->fo_flags & DFLAG_SEEKABLE) != 0 ?
2136 	    fo_seek(fp, offset, whence, td) : ESPIPE;
2137 	fdrop(fp, td);
2138 	return (error);
2139 }
2140 
2141 #if defined(COMPAT_43)
2142 /*
2143  * Reposition read/write file offset.
2144  */
2145 #ifndef _SYS_SYSPROTO_H_
2146 struct olseek_args {
2147 	int	fd;
2148 	long	offset;
2149 	int	whence;
2150 };
2151 #endif
2152 int
olseek(struct thread * td,struct olseek_args * uap)2153 olseek(struct thread *td, struct olseek_args *uap)
2154 {
2155 
2156 	return (kern_lseek(td, uap->fd, uap->offset, uap->whence));
2157 }
2158 #endif /* COMPAT_43 */
2159 
2160 #if defined(COMPAT_FREEBSD6)
2161 /* Version with the 'pad' argument */
2162 int
freebsd6_lseek(struct thread * td,struct freebsd6_lseek_args * uap)2163 freebsd6_lseek(struct thread *td, struct freebsd6_lseek_args *uap)
2164 {
2165 
2166 	return (kern_lseek(td, uap->fd, uap->offset, uap->whence));
2167 }
2168 #endif
2169 
2170 /*
2171  * Check access permissions using passed credentials.
2172  */
2173 static int
vn_access(struct vnode * vp,int user_flags,struct ucred * cred,struct thread * td)2174 vn_access(struct vnode *vp, int user_flags, struct ucred *cred,
2175      struct thread *td)
2176 {
2177 	accmode_t accmode;
2178 	int error;
2179 
2180 	/* Flags == 0 means only check for existence. */
2181 	if (user_flags == 0)
2182 		return (0);
2183 
2184 	accmode = 0;
2185 	if (user_flags & R_OK)
2186 		accmode |= VREAD;
2187 	if (user_flags & W_OK)
2188 		accmode |= VWRITE;
2189 	if (user_flags & X_OK)
2190 		accmode |= VEXEC;
2191 #ifdef MAC
2192 	error = mac_vnode_check_access(cred, vp, accmode);
2193 	if (error != 0)
2194 		return (error);
2195 #endif
2196 	if ((accmode & VWRITE) == 0 || (error = vn_writechk(vp)) == 0)
2197 		error = VOP_ACCESS(vp, accmode, cred, td);
2198 	return (error);
2199 }
2200 
2201 /*
2202  * Check access permissions using "real" credentials.
2203  */
2204 #ifndef _SYS_SYSPROTO_H_
2205 struct access_args {
2206 	char	*path;
2207 	int	amode;
2208 };
2209 #endif
2210 int
sys_access(struct thread * td,struct access_args * uap)2211 sys_access(struct thread *td, struct access_args *uap)
2212 {
2213 
2214 	return (kern_accessat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
2215 	    0, uap->amode));
2216 }
2217 
2218 #ifndef _SYS_SYSPROTO_H_
2219 struct faccessat_args {
2220 	int	dirfd;
2221 	char	*path;
2222 	int	amode;
2223 	int	flag;
2224 }
2225 #endif
2226 int
sys_faccessat(struct thread * td,struct faccessat_args * uap)2227 sys_faccessat(struct thread *td, struct faccessat_args *uap)
2228 {
2229 
2230 	return (kern_accessat(td, uap->fd, uap->path, UIO_USERSPACE, uap->flag,
2231 	    uap->amode));
2232 }
2233 
2234 int
kern_accessat(struct thread * td,int fd,const char * path,enum uio_seg pathseg,int flag,int amode)2235 kern_accessat(struct thread *td, int fd, const char *path,
2236     enum uio_seg pathseg, int flag, int amode)
2237 {
2238 	struct ucred *cred, *usecred;
2239 	struct vnode *vp;
2240 	struct nameidata nd;
2241 	int error;
2242 
2243 	if ((flag & ~(AT_EACCESS | AT_RESOLVE_BENEATH | AT_EMPTY_PATH |
2244 	    AT_SYMLINK_NOFOLLOW)) != 0)
2245 		return (EINVAL);
2246 	if (amode != F_OK && (amode & ~(R_OK | W_OK | X_OK)) != 0)
2247 		return (EINVAL);
2248 
2249 	/*
2250 	 * Create and modify a temporary credential instead of one that
2251 	 * is potentially shared (if we need one).
2252 	 */
2253 	cred = td->td_ucred;
2254 	if ((flag & AT_EACCESS) == 0 &&
2255 	    ((cred->cr_uid != cred->cr_ruid ||
2256 	    cred->cr_rgid != cred->cr_groups[0]))) {
2257 		usecred = crdup(cred);
2258 		usecred->cr_uid = cred->cr_ruid;
2259 		usecred->cr_groups[0] = cred->cr_rgid;
2260 		td->td_ucred = usecred;
2261 	} else
2262 		usecred = cred;
2263 	AUDIT_ARG_VALUE(amode);
2264 	NDINIT_ATRIGHTS(&nd, LOOKUP, LOCKSHARED | LOCKLEAF |
2265 	    AUDITVNODE1 | at2cnpflags(flag, AT_RESOLVE_BENEATH | AT_SYMLINK_NOFOLLOW |
2266 	    AT_EMPTY_PATH), pathseg, path, fd, &cap_fstat_rights);
2267 	if ((error = namei(&nd)) != 0)
2268 		goto out;
2269 	vp = nd.ni_vp;
2270 
2271 	error = vn_access(vp, amode, usecred, td);
2272 	NDFREE_PNBUF(&nd);
2273 	vput(vp);
2274 out:
2275 	if (usecred != cred) {
2276 		td->td_ucred = cred;
2277 		crfree(usecred);
2278 	}
2279 	return (error);
2280 }
2281 
2282 /*
2283  * Check access permissions using "effective" credentials.
2284  */
2285 #ifndef _SYS_SYSPROTO_H_
2286 struct eaccess_args {
2287 	char	*path;
2288 	int	amode;
2289 };
2290 #endif
2291 int
sys_eaccess(struct thread * td,struct eaccess_args * uap)2292 sys_eaccess(struct thread *td, struct eaccess_args *uap)
2293 {
2294 
2295 	return (kern_accessat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
2296 	    AT_EACCESS, uap->amode));
2297 }
2298 
2299 #if defined(COMPAT_43)
2300 /*
2301  * Get file status; this version follows links.
2302  */
2303 #ifndef _SYS_SYSPROTO_H_
2304 struct ostat_args {
2305 	char	*path;
2306 	struct ostat *ub;
2307 };
2308 #endif
2309 int
ostat(struct thread * td,struct ostat_args * uap)2310 ostat(struct thread *td, struct ostat_args *uap)
2311 {
2312 	struct stat sb;
2313 	struct ostat osb;
2314 	int error;
2315 
2316 	error = kern_statat(td, 0, AT_FDCWD, uap->path, UIO_USERSPACE, &sb);
2317 	if (error != 0)
2318 		return (error);
2319 	cvtstat(&sb, &osb);
2320 	return (copyout(&osb, uap->ub, sizeof (osb)));
2321 }
2322 
2323 /*
2324  * Get file status; this version does not follow links.
2325  */
2326 #ifndef _SYS_SYSPROTO_H_
2327 struct olstat_args {
2328 	char	*path;
2329 	struct ostat *ub;
2330 };
2331 #endif
2332 int
olstat(struct thread * td,struct olstat_args * uap)2333 olstat(struct thread *td, struct olstat_args *uap)
2334 {
2335 	struct stat sb;
2336 	struct ostat osb;
2337 	int error;
2338 
2339 	error = kern_statat(td, AT_SYMLINK_NOFOLLOW, AT_FDCWD, uap->path,
2340 	    UIO_USERSPACE, &sb);
2341 	if (error != 0)
2342 		return (error);
2343 	cvtstat(&sb, &osb);
2344 	return (copyout(&osb, uap->ub, sizeof (osb)));
2345 }
2346 
2347 /*
2348  * Convert from an old to a new stat structure.
2349  * XXX: many values are blindly truncated.
2350  */
2351 void
cvtstat(struct stat * st,struct ostat * ost)2352 cvtstat(struct stat *st, struct ostat *ost)
2353 {
2354 
2355 	bzero(ost, sizeof(*ost));
2356 	ost->st_dev = st->st_dev;
2357 	ost->st_ino = st->st_ino;
2358 	ost->st_mode = st->st_mode;
2359 	ost->st_nlink = st->st_nlink;
2360 	ost->st_uid = st->st_uid;
2361 	ost->st_gid = st->st_gid;
2362 	ost->st_rdev = st->st_rdev;
2363 	ost->st_size = MIN(st->st_size, INT32_MAX);
2364 	ost->st_atim = st->st_atim;
2365 	ost->st_mtim = st->st_mtim;
2366 	ost->st_ctim = st->st_ctim;
2367 	ost->st_blksize = st->st_blksize;
2368 	ost->st_blocks = st->st_blocks;
2369 	ost->st_flags = st->st_flags;
2370 	ost->st_gen = st->st_gen;
2371 }
2372 #endif /* COMPAT_43 */
2373 
2374 #if defined(COMPAT_43) || defined(COMPAT_FREEBSD11)
2375 int ino64_trunc_error;
2376 SYSCTL_INT(_vfs, OID_AUTO, ino64_trunc_error, CTLFLAG_RW,
2377     &ino64_trunc_error, 0,
2378     "Error on truncation of device, file or inode number, or link count");
2379 
2380 int
freebsd11_cvtstat(struct stat * st,struct freebsd11_stat * ost)2381 freebsd11_cvtstat(struct stat *st, struct freebsd11_stat *ost)
2382 {
2383 
2384 	ost->st_dev = st->st_dev;
2385 	if (ost->st_dev != st->st_dev) {
2386 		switch (ino64_trunc_error) {
2387 		default:
2388 			/*
2389 			 * Since dev_t is almost raw, don't clamp to the
2390 			 * maximum for case 2, but ignore the error.
2391 			 */
2392 			break;
2393 		case 1:
2394 			return (EOVERFLOW);
2395 		}
2396 	}
2397 	ost->st_ino = st->st_ino;
2398 	if (ost->st_ino != st->st_ino) {
2399 		switch (ino64_trunc_error) {
2400 		default:
2401 		case 0:
2402 			break;
2403 		case 1:
2404 			return (EOVERFLOW);
2405 		case 2:
2406 			ost->st_ino = UINT32_MAX;
2407 			break;
2408 		}
2409 	}
2410 	ost->st_mode = st->st_mode;
2411 	ost->st_nlink = st->st_nlink;
2412 	if (ost->st_nlink != st->st_nlink) {
2413 		switch (ino64_trunc_error) {
2414 		default:
2415 		case 0:
2416 			break;
2417 		case 1:
2418 			return (EOVERFLOW);
2419 		case 2:
2420 			ost->st_nlink = UINT16_MAX;
2421 			break;
2422 		}
2423 	}
2424 	ost->st_uid = st->st_uid;
2425 	ost->st_gid = st->st_gid;
2426 	ost->st_rdev = st->st_rdev;
2427 	if (ost->st_rdev != st->st_rdev) {
2428 		switch (ino64_trunc_error) {
2429 		default:
2430 			break;
2431 		case 1:
2432 			return (EOVERFLOW);
2433 		}
2434 	}
2435 	ost->st_atim = st->st_atim;
2436 	ost->st_mtim = st->st_mtim;
2437 	ost->st_ctim = st->st_ctim;
2438 	ost->st_size = st->st_size;
2439 	ost->st_blocks = st->st_blocks;
2440 	ost->st_blksize = st->st_blksize;
2441 	ost->st_flags = st->st_flags;
2442 	ost->st_gen = st->st_gen;
2443 	ost->st_lspare = 0;
2444 	ost->st_birthtim = st->st_birthtim;
2445 	bzero((char *)&ost->st_birthtim + sizeof(ost->st_birthtim),
2446 	    sizeof(*ost) - offsetof(struct freebsd11_stat,
2447 	    st_birthtim) - sizeof(ost->st_birthtim));
2448 	return (0);
2449 }
2450 
2451 int
freebsd11_stat(struct thread * td,struct freebsd11_stat_args * uap)2452 freebsd11_stat(struct thread *td, struct freebsd11_stat_args* uap)
2453 {
2454 	struct stat sb;
2455 	struct freebsd11_stat osb;
2456 	int error;
2457 
2458 	error = kern_statat(td, 0, AT_FDCWD, uap->path, UIO_USERSPACE, &sb);
2459 	if (error != 0)
2460 		return (error);
2461 	error = freebsd11_cvtstat(&sb, &osb);
2462 	if (error == 0)
2463 		error = copyout(&osb, uap->ub, sizeof(osb));
2464 	return (error);
2465 }
2466 
2467 int
freebsd11_lstat(struct thread * td,struct freebsd11_lstat_args * uap)2468 freebsd11_lstat(struct thread *td, struct freebsd11_lstat_args* uap)
2469 {
2470 	struct stat sb;
2471 	struct freebsd11_stat osb;
2472 	int error;
2473 
2474 	error = kern_statat(td, AT_SYMLINK_NOFOLLOW, AT_FDCWD, uap->path,
2475 	    UIO_USERSPACE, &sb);
2476 	if (error != 0)
2477 		return (error);
2478 	error = freebsd11_cvtstat(&sb, &osb);
2479 	if (error == 0)
2480 		error = copyout(&osb, uap->ub, sizeof(osb));
2481 	return (error);
2482 }
2483 
2484 int
freebsd11_fhstat(struct thread * td,struct freebsd11_fhstat_args * uap)2485 freebsd11_fhstat(struct thread *td, struct freebsd11_fhstat_args* uap)
2486 {
2487 	struct fhandle fh;
2488 	struct stat sb;
2489 	struct freebsd11_stat osb;
2490 	int error;
2491 
2492 	error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t));
2493 	if (error != 0)
2494 		return (error);
2495 	error = kern_fhstat(td, fh, &sb);
2496 	if (error != 0)
2497 		return (error);
2498 	error = freebsd11_cvtstat(&sb, &osb);
2499 	if (error == 0)
2500 		error = copyout(&osb, uap->sb, sizeof(osb));
2501 	return (error);
2502 }
2503 
2504 int
freebsd11_fstatat(struct thread * td,struct freebsd11_fstatat_args * uap)2505 freebsd11_fstatat(struct thread *td, struct freebsd11_fstatat_args* uap)
2506 {
2507 	struct stat sb;
2508 	struct freebsd11_stat osb;
2509 	int error;
2510 
2511 	error = kern_statat(td, uap->flag, uap->fd, uap->path,
2512 	    UIO_USERSPACE, &sb);
2513 	if (error != 0)
2514 		return (error);
2515 	error = freebsd11_cvtstat(&sb, &osb);
2516 	if (error == 0)
2517 		error = copyout(&osb, uap->buf, sizeof(osb));
2518 	return (error);
2519 }
2520 #endif	/* COMPAT_FREEBSD11 */
2521 
2522 /*
2523  * Get file status
2524  */
2525 #ifndef _SYS_SYSPROTO_H_
2526 struct fstatat_args {
2527 	int	fd;
2528 	char	*path;
2529 	struct stat	*buf;
2530 	int	flag;
2531 }
2532 #endif
2533 int
sys_fstatat(struct thread * td,struct fstatat_args * uap)2534 sys_fstatat(struct thread *td, struct fstatat_args *uap)
2535 {
2536 	struct stat sb;
2537 	int error;
2538 
2539 	error = kern_statat(td, uap->flag, uap->fd, uap->path,
2540 	    UIO_USERSPACE, &sb);
2541 	if (error == 0)
2542 		error = copyout(&sb, uap->buf, sizeof (sb));
2543 	return (error);
2544 }
2545 
2546 int
kern_statat(struct thread * td,int flag,int fd,const char * path,enum uio_seg pathseg,struct stat * sbp)2547 kern_statat(struct thread *td, int flag, int fd, const char *path,
2548     enum uio_seg pathseg, struct stat *sbp)
2549 {
2550 	struct nameidata nd;
2551 	int error;
2552 
2553 	if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_RESOLVE_BENEATH |
2554 	    AT_EMPTY_PATH)) != 0)
2555 		return (EINVAL);
2556 
2557 	NDINIT_ATRIGHTS(&nd, LOOKUP, at2cnpflags(flag, AT_RESOLVE_BENEATH |
2558 	    AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH) | LOCKSHARED | LOCKLEAF |
2559 	    AUDITVNODE1, pathseg, path, fd, &cap_fstat_rights);
2560 
2561 	if ((error = namei(&nd)) != 0) {
2562 		if (error == ENOTDIR &&
2563 		    (nd.ni_resflags & NIRES_EMPTYPATH) != 0)
2564 			error = kern_fstat(td, fd, sbp);
2565 		return (error);
2566 	}
2567 	error = VOP_STAT(nd.ni_vp, sbp, td->td_ucred, NOCRED);
2568 	NDFREE_PNBUF(&nd);
2569 	vput(nd.ni_vp);
2570 #ifdef __STAT_TIME_T_EXT
2571 	sbp->st_atim_ext = 0;
2572 	sbp->st_mtim_ext = 0;
2573 	sbp->st_ctim_ext = 0;
2574 	sbp->st_btim_ext = 0;
2575 #endif
2576 #ifdef KTRACE
2577 	if (KTRPOINT(td, KTR_STRUCT))
2578 		ktrstat_error(sbp, error);
2579 #endif
2580 	return (error);
2581 }
2582 
2583 #if defined(COMPAT_FREEBSD11)
2584 /*
2585  * Implementation of the NetBSD [l]stat() functions.
2586  */
2587 int
freebsd11_cvtnstat(struct stat * sb,struct nstat * nsb)2588 freebsd11_cvtnstat(struct stat *sb, struct nstat *nsb)
2589 {
2590 	struct freebsd11_stat sb11;
2591 	int error;
2592 
2593 	error = freebsd11_cvtstat(sb, &sb11);
2594 	if (error != 0)
2595 		return (error);
2596 
2597 	bzero(nsb, sizeof(*nsb));
2598 	CP(sb11, *nsb, st_dev);
2599 	CP(sb11, *nsb, st_ino);
2600 	CP(sb11, *nsb, st_mode);
2601 	CP(sb11, *nsb, st_nlink);
2602 	CP(sb11, *nsb, st_uid);
2603 	CP(sb11, *nsb, st_gid);
2604 	CP(sb11, *nsb, st_rdev);
2605 	CP(sb11, *nsb, st_atim);
2606 	CP(sb11, *nsb, st_mtim);
2607 	CP(sb11, *nsb, st_ctim);
2608 	CP(sb11, *nsb, st_size);
2609 	CP(sb11, *nsb, st_blocks);
2610 	CP(sb11, *nsb, st_blksize);
2611 	CP(sb11, *nsb, st_flags);
2612 	CP(sb11, *nsb, st_gen);
2613 	CP(sb11, *nsb, st_birthtim);
2614 	return (0);
2615 }
2616 
2617 #ifndef _SYS_SYSPROTO_H_
2618 struct freebsd11_nstat_args {
2619 	char	*path;
2620 	struct nstat *ub;
2621 };
2622 #endif
2623 int
freebsd11_nstat(struct thread * td,struct freebsd11_nstat_args * uap)2624 freebsd11_nstat(struct thread *td, struct freebsd11_nstat_args *uap)
2625 {
2626 	struct stat sb;
2627 	struct nstat nsb;
2628 	int error;
2629 
2630 	error = kern_statat(td, 0, AT_FDCWD, uap->path, UIO_USERSPACE, &sb);
2631 	if (error != 0)
2632 		return (error);
2633 	error = freebsd11_cvtnstat(&sb, &nsb);
2634 	if (error == 0)
2635 		error = copyout(&nsb, uap->ub, sizeof (nsb));
2636 	return (error);
2637 }
2638 
2639 /*
2640  * NetBSD lstat.  Get file status; this version does not follow links.
2641  */
2642 #ifndef _SYS_SYSPROTO_H_
2643 struct freebsd11_nlstat_args {
2644 	char	*path;
2645 	struct nstat *ub;
2646 };
2647 #endif
2648 int
freebsd11_nlstat(struct thread * td,struct freebsd11_nlstat_args * uap)2649 freebsd11_nlstat(struct thread *td, struct freebsd11_nlstat_args *uap)
2650 {
2651 	struct stat sb;
2652 	struct nstat nsb;
2653 	int error;
2654 
2655 	error = kern_statat(td, AT_SYMLINK_NOFOLLOW, AT_FDCWD, uap->path,
2656 	    UIO_USERSPACE, &sb);
2657 	if (error != 0)
2658 		return (error);
2659 	error = freebsd11_cvtnstat(&sb, &nsb);
2660 	if (error == 0)
2661 		error = copyout(&nsb, uap->ub, sizeof (nsb));
2662 	return (error);
2663 }
2664 #endif /* COMPAT_FREEBSD11 */
2665 
2666 /*
2667  * Get configurable pathname variables.
2668  */
2669 #ifndef _SYS_SYSPROTO_H_
2670 struct pathconf_args {
2671 	char	*path;
2672 	int	name;
2673 };
2674 #endif
2675 int
sys_pathconf(struct thread * td,struct pathconf_args * uap)2676 sys_pathconf(struct thread *td, struct pathconf_args *uap)
2677 {
2678 	long value;
2679 	int error;
2680 
2681 	error = kern_pathconf(td, uap->path, UIO_USERSPACE, uap->name, FOLLOW,
2682 	    &value);
2683 	if (error == 0)
2684 		td->td_retval[0] = value;
2685 	return (error);
2686 }
2687 
2688 #ifndef _SYS_SYSPROTO_H_
2689 struct lpathconf_args {
2690 	char	*path;
2691 	int	name;
2692 };
2693 #endif
2694 int
sys_lpathconf(struct thread * td,struct lpathconf_args * uap)2695 sys_lpathconf(struct thread *td, struct lpathconf_args *uap)
2696 {
2697 	long value;
2698 	int error;
2699 
2700 	error = kern_pathconf(td, uap->path, UIO_USERSPACE, uap->name,
2701 	    NOFOLLOW, &value);
2702 	if (error == 0)
2703 		td->td_retval[0] = value;
2704 	return (error);
2705 }
2706 
2707 int
kern_pathconf(struct thread * td,const char * path,enum uio_seg pathseg,int name,u_long flags,long * valuep)2708 kern_pathconf(struct thread *td, const char *path, enum uio_seg pathseg,
2709     int name, u_long flags, long *valuep)
2710 {
2711 	struct nameidata nd;
2712 	int error;
2713 
2714 	NDINIT(&nd, LOOKUP, LOCKSHARED | LOCKLEAF | AUDITVNODE1 | flags,
2715 	       pathseg, path);
2716 	if ((error = namei(&nd)) != 0)
2717 		return (error);
2718 	NDFREE_PNBUF(&nd);
2719 
2720 	error = VOP_PATHCONF(nd.ni_vp, name, valuep);
2721 	vput(nd.ni_vp);
2722 	return (error);
2723 }
2724 
2725 /*
2726  * Return target name of a symbolic link.
2727  */
2728 #ifndef _SYS_SYSPROTO_H_
2729 struct readlink_args {
2730 	char	*path;
2731 	char	*buf;
2732 	size_t	count;
2733 };
2734 #endif
2735 int
sys_readlink(struct thread * td,struct readlink_args * uap)2736 sys_readlink(struct thread *td, struct readlink_args *uap)
2737 {
2738 
2739 	return (kern_readlinkat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
2740 	    uap->buf, UIO_USERSPACE, uap->count));
2741 }
2742 #ifndef _SYS_SYSPROTO_H_
2743 struct readlinkat_args {
2744 	int	fd;
2745 	char	*path;
2746 	char	*buf;
2747 	size_t	bufsize;
2748 };
2749 #endif
2750 int
sys_readlinkat(struct thread * td,struct readlinkat_args * uap)2751 sys_readlinkat(struct thread *td, struct readlinkat_args *uap)
2752 {
2753 
2754 	return (kern_readlinkat(td, uap->fd, uap->path, UIO_USERSPACE,
2755 	    uap->buf, UIO_USERSPACE, uap->bufsize));
2756 }
2757 
2758 int
kern_readlinkat(struct thread * td,int fd,const char * path,enum uio_seg pathseg,char * buf,enum uio_seg bufseg,size_t count)2759 kern_readlinkat(struct thread *td, int fd, const char *path,
2760     enum uio_seg pathseg, char *buf, enum uio_seg bufseg, size_t count)
2761 {
2762 	struct vnode *vp;
2763 	struct nameidata nd;
2764 	int error;
2765 
2766 	if (count > IOSIZE_MAX)
2767 		return (EINVAL);
2768 
2769 	NDINIT_AT(&nd, LOOKUP, NOFOLLOW | LOCKSHARED | LOCKLEAF | AUDITVNODE1 |
2770 	    EMPTYPATH, pathseg, path, fd);
2771 
2772 	if ((error = namei(&nd)) != 0)
2773 		return (error);
2774 	NDFREE_PNBUF(&nd);
2775 	vp = nd.ni_vp;
2776 
2777 	error = kern_readlink_vp(vp, buf, bufseg, count, td);
2778 	vput(vp);
2779 
2780 	return (error);
2781 }
2782 
2783 /*
2784  * Helper function to readlink from a vnode
2785  */
2786 static int
kern_readlink_vp(struct vnode * vp,char * buf,enum uio_seg bufseg,size_t count,struct thread * td)2787 kern_readlink_vp(struct vnode *vp, char *buf, enum uio_seg bufseg, size_t count,
2788     struct thread *td)
2789 {
2790 	struct iovec aiov;
2791 	struct uio auio;
2792 	int error;
2793 
2794 	ASSERT_VOP_LOCKED(vp, "kern_readlink_vp(): vp not locked");
2795 #ifdef MAC
2796 	error = mac_vnode_check_readlink(td->td_ucred, vp);
2797 	if (error != 0)
2798 		return (error);
2799 #endif
2800 	if (vp->v_type != VLNK && (vp->v_vflag & VV_READLINK) == 0)
2801 		return (EINVAL);
2802 
2803 	aiov.iov_base = buf;
2804 	aiov.iov_len = count;
2805 	auio.uio_iov = &aiov;
2806 	auio.uio_iovcnt = 1;
2807 	auio.uio_offset = 0;
2808 	auio.uio_rw = UIO_READ;
2809 	auio.uio_segflg = bufseg;
2810 	auio.uio_td = td;
2811 	auio.uio_resid = count;
2812 	error = VOP_READLINK(vp, &auio, td->td_ucred);
2813 	td->td_retval[0] = count - auio.uio_resid;
2814 	return (error);
2815 }
2816 
2817 /*
2818  * Common implementation code for chflags() and fchflags().
2819  */
2820 static int
setfflags(struct thread * td,struct vnode * vp,u_long flags)2821 setfflags(struct thread *td, struct vnode *vp, u_long flags)
2822 {
2823 	struct mount *mp;
2824 	struct vattr vattr;
2825 	int error;
2826 
2827 	/* We can't support the value matching VNOVAL. */
2828 	if (flags == VNOVAL)
2829 		return (EOPNOTSUPP);
2830 
2831 	/*
2832 	 * Prevent non-root users from setting flags on devices.  When
2833 	 * a device is reused, users can retain ownership of the device
2834 	 * if they are allowed to set flags and programs assume that
2835 	 * chown can't fail when done as root.
2836 	 */
2837 	if (vp->v_type == VCHR || vp->v_type == VBLK) {
2838 		error = priv_check(td, PRIV_VFS_CHFLAGS_DEV);
2839 		if (error != 0)
2840 			return (error);
2841 	}
2842 
2843 	if ((error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH)) != 0)
2844 		return (error);
2845 	VATTR_NULL(&vattr);
2846 	vattr.va_flags = flags;
2847 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2848 #ifdef MAC
2849 	error = mac_vnode_check_setflags(td->td_ucred, vp, vattr.va_flags);
2850 	if (error == 0)
2851 #endif
2852 		error = VOP_SETATTR(vp, &vattr, td->td_ucred);
2853 	VOP_UNLOCK(vp);
2854 	vn_finished_write(mp);
2855 	return (error);
2856 }
2857 
2858 /*
2859  * Change flags of a file given a path name.
2860  */
2861 #ifndef _SYS_SYSPROTO_H_
2862 struct chflags_args {
2863 	const char *path;
2864 	u_long	flags;
2865 };
2866 #endif
2867 int
sys_chflags(struct thread * td,struct chflags_args * uap)2868 sys_chflags(struct thread *td, struct chflags_args *uap)
2869 {
2870 
2871 	return (kern_chflagsat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
2872 	    uap->flags, 0));
2873 }
2874 
2875 #ifndef _SYS_SYSPROTO_H_
2876 struct chflagsat_args {
2877 	int	fd;
2878 	const char *path;
2879 	u_long	flags;
2880 	int	atflag;
2881 }
2882 #endif
2883 int
sys_chflagsat(struct thread * td,struct chflagsat_args * uap)2884 sys_chflagsat(struct thread *td, struct chflagsat_args *uap)
2885 {
2886 
2887 	return (kern_chflagsat(td, uap->fd, uap->path, UIO_USERSPACE,
2888 	    uap->flags, uap->atflag));
2889 }
2890 
2891 /*
2892  * Same as chflags() but doesn't follow symlinks.
2893  */
2894 #ifndef _SYS_SYSPROTO_H_
2895 struct lchflags_args {
2896 	const char *path;
2897 	u_long flags;
2898 };
2899 #endif
2900 int
sys_lchflags(struct thread * td,struct lchflags_args * uap)2901 sys_lchflags(struct thread *td, struct lchflags_args *uap)
2902 {
2903 
2904 	return (kern_chflagsat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
2905 	    uap->flags, AT_SYMLINK_NOFOLLOW));
2906 }
2907 
2908 static int
kern_chflagsat(struct thread * td,int fd,const char * path,enum uio_seg pathseg,u_long flags,int atflag)2909 kern_chflagsat(struct thread *td, int fd, const char *path,
2910     enum uio_seg pathseg, u_long flags, int atflag)
2911 {
2912 	struct nameidata nd;
2913 	int error;
2914 
2915 	if ((atflag & ~(AT_SYMLINK_NOFOLLOW | AT_RESOLVE_BENEATH |
2916 	    AT_EMPTY_PATH)) != 0)
2917 		return (EINVAL);
2918 
2919 	AUDIT_ARG_FFLAGS(flags);
2920 	NDINIT_ATRIGHTS(&nd, LOOKUP, at2cnpflags(atflag, AT_SYMLINK_NOFOLLOW |
2921 	    AT_RESOLVE_BENEATH | AT_EMPTY_PATH) | AUDITVNODE1, pathseg, path,
2922 	    fd, &cap_fchflags_rights);
2923 	if ((error = namei(&nd)) != 0)
2924 		return (error);
2925 	NDFREE_PNBUF(&nd);
2926 	error = setfflags(td, nd.ni_vp, flags);
2927 	vrele(nd.ni_vp);
2928 	return (error);
2929 }
2930 
2931 /*
2932  * Change flags of a file given a file descriptor.
2933  */
2934 #ifndef _SYS_SYSPROTO_H_
2935 struct fchflags_args {
2936 	int	fd;
2937 	u_long	flags;
2938 };
2939 #endif
2940 int
sys_fchflags(struct thread * td,struct fchflags_args * uap)2941 sys_fchflags(struct thread *td, struct fchflags_args *uap)
2942 {
2943 	struct file *fp;
2944 	int error;
2945 
2946 	AUDIT_ARG_FD(uap->fd);
2947 	AUDIT_ARG_FFLAGS(uap->flags);
2948 	error = getvnode(td, uap->fd, &cap_fchflags_rights,
2949 	    &fp);
2950 	if (error != 0)
2951 		return (error);
2952 #ifdef AUDIT
2953 	if (AUDITING_TD(td)) {
2954 		vn_lock(fp->f_vnode, LK_SHARED | LK_RETRY);
2955 		AUDIT_ARG_VNODE1(fp->f_vnode);
2956 		VOP_UNLOCK(fp->f_vnode);
2957 	}
2958 #endif
2959 	error = setfflags(td, fp->f_vnode, uap->flags);
2960 	fdrop(fp, td);
2961 	return (error);
2962 }
2963 
2964 /*
2965  * Common implementation code for chmod(), lchmod() and fchmod().
2966  */
2967 int
setfmode(struct thread * td,struct ucred * cred,struct vnode * vp,int mode)2968 setfmode(struct thread *td, struct ucred *cred, struct vnode *vp, int mode)
2969 {
2970 	struct mount *mp;
2971 	struct vattr vattr;
2972 	int error;
2973 
2974 	if ((error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH)) != 0)
2975 		return (error);
2976 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
2977 	VATTR_NULL(&vattr);
2978 	vattr.va_mode = mode & ALLPERMS;
2979 #ifdef MAC
2980 	error = mac_vnode_check_setmode(cred, vp, vattr.va_mode);
2981 	if (error == 0)
2982 #endif
2983 		error = VOP_SETATTR(vp, &vattr, cred);
2984 	VOP_UNLOCK(vp);
2985 	vn_finished_write(mp);
2986 	return (error);
2987 }
2988 
2989 /*
2990  * Change mode of a file given path name.
2991  */
2992 #ifndef _SYS_SYSPROTO_H_
2993 struct chmod_args {
2994 	char	*path;
2995 	int	mode;
2996 };
2997 #endif
2998 int
sys_chmod(struct thread * td,struct chmod_args * uap)2999 sys_chmod(struct thread *td, struct chmod_args *uap)
3000 {
3001 
3002 	return (kern_fchmodat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
3003 	    uap->mode, 0));
3004 }
3005 
3006 #ifndef _SYS_SYSPROTO_H_
3007 struct fchmodat_args {
3008 	int	dirfd;
3009 	char	*path;
3010 	mode_t	mode;
3011 	int	flag;
3012 }
3013 #endif
3014 int
sys_fchmodat(struct thread * td,struct fchmodat_args * uap)3015 sys_fchmodat(struct thread *td, struct fchmodat_args *uap)
3016 {
3017 
3018 	return (kern_fchmodat(td, uap->fd, uap->path, UIO_USERSPACE,
3019 	    uap->mode, uap->flag));
3020 }
3021 
3022 /*
3023  * Change mode of a file given path name (don't follow links.)
3024  */
3025 #ifndef _SYS_SYSPROTO_H_
3026 struct lchmod_args {
3027 	char	*path;
3028 	int	mode;
3029 };
3030 #endif
3031 int
sys_lchmod(struct thread * td,struct lchmod_args * uap)3032 sys_lchmod(struct thread *td, struct lchmod_args *uap)
3033 {
3034 
3035 	return (kern_fchmodat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
3036 	    uap->mode, AT_SYMLINK_NOFOLLOW));
3037 }
3038 
3039 int
kern_fchmodat(struct thread * td,int fd,const char * path,enum uio_seg pathseg,mode_t mode,int flag)3040 kern_fchmodat(struct thread *td, int fd, const char *path,
3041     enum uio_seg pathseg, mode_t mode, int flag)
3042 {
3043 	struct nameidata nd;
3044 	int error;
3045 
3046 	if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_RESOLVE_BENEATH |
3047 	    AT_EMPTY_PATH)) != 0)
3048 		return (EINVAL);
3049 
3050 	AUDIT_ARG_MODE(mode);
3051 	NDINIT_ATRIGHTS(&nd, LOOKUP, at2cnpflags(flag, AT_SYMLINK_NOFOLLOW |
3052 	    AT_RESOLVE_BENEATH | AT_EMPTY_PATH) | AUDITVNODE1, pathseg, path,
3053 	    fd, &cap_fchmod_rights);
3054 	if ((error = namei(&nd)) != 0)
3055 		return (error);
3056 	NDFREE_PNBUF(&nd);
3057 	error = setfmode(td, td->td_ucred, nd.ni_vp, mode);
3058 	vrele(nd.ni_vp);
3059 	return (error);
3060 }
3061 
3062 /*
3063  * Change mode of a file given a file descriptor.
3064  */
3065 #ifndef _SYS_SYSPROTO_H_
3066 struct fchmod_args {
3067 	int	fd;
3068 	int	mode;
3069 };
3070 #endif
3071 int
sys_fchmod(struct thread * td,struct fchmod_args * uap)3072 sys_fchmod(struct thread *td, struct fchmod_args *uap)
3073 {
3074 	struct file *fp;
3075 	int error;
3076 
3077 	AUDIT_ARG_FD(uap->fd);
3078 	AUDIT_ARG_MODE(uap->mode);
3079 
3080 	error = fget(td, uap->fd, &cap_fchmod_rights, &fp);
3081 	if (error != 0)
3082 		return (error);
3083 	error = fo_chmod(fp, uap->mode, td->td_ucred, td);
3084 	fdrop(fp, td);
3085 	return (error);
3086 }
3087 
3088 /*
3089  * Common implementation for chown(), lchown(), and fchown()
3090  */
3091 int
setfown(struct thread * td,struct ucred * cred,struct vnode * vp,uid_t uid,gid_t gid)3092 setfown(struct thread *td, struct ucred *cred, struct vnode *vp, uid_t uid,
3093     gid_t gid)
3094 {
3095 	struct mount *mp;
3096 	struct vattr vattr;
3097 	int error;
3098 
3099 	if ((error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH)) != 0)
3100 		return (error);
3101 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3102 	VATTR_NULL(&vattr);
3103 	vattr.va_uid = uid;
3104 	vattr.va_gid = gid;
3105 #ifdef MAC
3106 	error = mac_vnode_check_setowner(cred, vp, vattr.va_uid,
3107 	    vattr.va_gid);
3108 	if (error == 0)
3109 #endif
3110 		error = VOP_SETATTR(vp, &vattr, cred);
3111 	VOP_UNLOCK(vp);
3112 	vn_finished_write(mp);
3113 	return (error);
3114 }
3115 
3116 /*
3117  * Set ownership given a path name.
3118  */
3119 #ifndef _SYS_SYSPROTO_H_
3120 struct chown_args {
3121 	char	*path;
3122 	int	uid;
3123 	int	gid;
3124 };
3125 #endif
3126 int
sys_chown(struct thread * td,struct chown_args * uap)3127 sys_chown(struct thread *td, struct chown_args *uap)
3128 {
3129 
3130 	return (kern_fchownat(td, AT_FDCWD, uap->path, UIO_USERSPACE, uap->uid,
3131 	    uap->gid, 0));
3132 }
3133 
3134 #ifndef _SYS_SYSPROTO_H_
3135 struct fchownat_args {
3136 	int fd;
3137 	const char * path;
3138 	uid_t uid;
3139 	gid_t gid;
3140 	int flag;
3141 };
3142 #endif
3143 int
sys_fchownat(struct thread * td,struct fchownat_args * uap)3144 sys_fchownat(struct thread *td, struct fchownat_args *uap)
3145 {
3146 
3147 	return (kern_fchownat(td, uap->fd, uap->path, UIO_USERSPACE, uap->uid,
3148 	    uap->gid, uap->flag));
3149 }
3150 
3151 int
kern_fchownat(struct thread * td,int fd,const char * path,enum uio_seg pathseg,int uid,int gid,int flag)3152 kern_fchownat(struct thread *td, int fd, const char *path,
3153     enum uio_seg pathseg, int uid, int gid, int flag)
3154 {
3155 	struct nameidata nd;
3156 	int error;
3157 
3158 	if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_RESOLVE_BENEATH |
3159 	    AT_EMPTY_PATH)) != 0)
3160 		return (EINVAL);
3161 
3162 	AUDIT_ARG_OWNER(uid, gid);
3163 	NDINIT_ATRIGHTS(&nd, LOOKUP, at2cnpflags(flag, AT_SYMLINK_NOFOLLOW |
3164 	    AT_RESOLVE_BENEATH | AT_EMPTY_PATH) | AUDITVNODE1, pathseg, path,
3165 	    fd, &cap_fchown_rights);
3166 
3167 	if ((error = namei(&nd)) != 0)
3168 		return (error);
3169 	NDFREE_PNBUF(&nd);
3170 	error = setfown(td, td->td_ucred, nd.ni_vp, uid, gid);
3171 	vrele(nd.ni_vp);
3172 	return (error);
3173 }
3174 
3175 /*
3176  * Set ownership given a path name, do not cross symlinks.
3177  */
3178 #ifndef _SYS_SYSPROTO_H_
3179 struct lchown_args {
3180 	char	*path;
3181 	int	uid;
3182 	int	gid;
3183 };
3184 #endif
3185 int
sys_lchown(struct thread * td,struct lchown_args * uap)3186 sys_lchown(struct thread *td, struct lchown_args *uap)
3187 {
3188 
3189 	return (kern_fchownat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
3190 	    uap->uid, uap->gid, AT_SYMLINK_NOFOLLOW));
3191 }
3192 
3193 /*
3194  * Set ownership given a file descriptor.
3195  */
3196 #ifndef _SYS_SYSPROTO_H_
3197 struct fchown_args {
3198 	int	fd;
3199 	int	uid;
3200 	int	gid;
3201 };
3202 #endif
3203 int
sys_fchown(struct thread * td,struct fchown_args * uap)3204 sys_fchown(struct thread *td, struct fchown_args *uap)
3205 {
3206 	struct file *fp;
3207 	int error;
3208 
3209 	AUDIT_ARG_FD(uap->fd);
3210 	AUDIT_ARG_OWNER(uap->uid, uap->gid);
3211 	error = fget(td, uap->fd, &cap_fchown_rights, &fp);
3212 	if (error != 0)
3213 		return (error);
3214 	error = fo_chown(fp, uap->uid, uap->gid, td->td_ucred, td);
3215 	fdrop(fp, td);
3216 	return (error);
3217 }
3218 
3219 /*
3220  * Common implementation code for utimes(), lutimes(), and futimes().
3221  */
3222 static int
getutimes(const struct timeval * usrtvp,enum uio_seg tvpseg,struct timespec * tsp)3223 getutimes(const struct timeval *usrtvp, enum uio_seg tvpseg,
3224     struct timespec *tsp)
3225 {
3226 	struct timeval tv[2];
3227 	const struct timeval *tvp;
3228 	int error;
3229 
3230 	if (usrtvp == NULL) {
3231 		vfs_timestamp(&tsp[0]);
3232 		tsp[1] = tsp[0];
3233 	} else {
3234 		if (tvpseg == UIO_SYSSPACE) {
3235 			tvp = usrtvp;
3236 		} else {
3237 			if ((error = copyin(usrtvp, tv, sizeof(tv))) != 0)
3238 				return (error);
3239 			tvp = tv;
3240 		}
3241 
3242 		if (tvp[0].tv_usec < 0 || tvp[0].tv_usec >= 1000000 ||
3243 		    tvp[1].tv_usec < 0 || tvp[1].tv_usec >= 1000000)
3244 			return (EINVAL);
3245 		TIMEVAL_TO_TIMESPEC(&tvp[0], &tsp[0]);
3246 		TIMEVAL_TO_TIMESPEC(&tvp[1], &tsp[1]);
3247 	}
3248 	return (0);
3249 }
3250 
3251 /*
3252  * Common implementation code for futimens(), utimensat().
3253  */
3254 #define	UTIMENS_NULL	0x1
3255 #define	UTIMENS_EXIT	0x2
3256 static int
getutimens(const struct timespec * usrtsp,enum uio_seg tspseg,struct timespec * tsp,int * retflags)3257 getutimens(const struct timespec *usrtsp, enum uio_seg tspseg,
3258     struct timespec *tsp, int *retflags)
3259 {
3260 	struct timespec tsnow;
3261 	int error;
3262 
3263 	vfs_timestamp(&tsnow);
3264 	*retflags = 0;
3265 	if (usrtsp == NULL) {
3266 		tsp[0] = tsnow;
3267 		tsp[1] = tsnow;
3268 		*retflags |= UTIMENS_NULL;
3269 		return (0);
3270 	}
3271 	if (tspseg == UIO_SYSSPACE) {
3272 		tsp[0] = usrtsp[0];
3273 		tsp[1] = usrtsp[1];
3274 	} else if ((error = copyin(usrtsp, tsp, sizeof(*tsp) * 2)) != 0)
3275 		return (error);
3276 	if (tsp[0].tv_nsec == UTIME_OMIT && tsp[1].tv_nsec == UTIME_OMIT)
3277 		*retflags |= UTIMENS_EXIT;
3278 	if (tsp[0].tv_nsec == UTIME_NOW && tsp[1].tv_nsec == UTIME_NOW)
3279 		*retflags |= UTIMENS_NULL;
3280 	if (tsp[0].tv_nsec == UTIME_OMIT)
3281 		tsp[0].tv_sec = VNOVAL;
3282 	else if (tsp[0].tv_nsec == UTIME_NOW)
3283 		tsp[0] = tsnow;
3284 	else if (tsp[0].tv_nsec < 0 || tsp[0].tv_nsec >= 1000000000L)
3285 		return (EINVAL);
3286 	if (tsp[1].tv_nsec == UTIME_OMIT)
3287 		tsp[1].tv_sec = VNOVAL;
3288 	else if (tsp[1].tv_nsec == UTIME_NOW)
3289 		tsp[1] = tsnow;
3290 	else if (tsp[1].tv_nsec < 0 || tsp[1].tv_nsec >= 1000000000L)
3291 		return (EINVAL);
3292 
3293 	return (0);
3294 }
3295 
3296 /*
3297  * Common implementation code for utimes(), lutimes(), futimes(), futimens(),
3298  * and utimensat().
3299  */
3300 static int
setutimes(struct thread * td,struct vnode * vp,const struct timespec * ts,int numtimes,int nullflag)3301 setutimes(struct thread *td, struct vnode *vp, const struct timespec *ts,
3302     int numtimes, int nullflag)
3303 {
3304 	struct mount *mp;
3305 	struct vattr vattr;
3306 	int error;
3307 	bool setbirthtime;
3308 
3309 	setbirthtime = false;
3310 	vattr.va_birthtime.tv_sec = VNOVAL;
3311 	vattr.va_birthtime.tv_nsec = 0;
3312 
3313 	if ((error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH)) != 0)
3314 		return (error);
3315 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3316 	if (numtimes < 3 && VOP_GETATTR(vp, &vattr, td->td_ucred) == 0 &&
3317 	    timespeccmp(&ts[1], &vattr.va_birthtime, < ))
3318 		setbirthtime = true;
3319 	VATTR_NULL(&vattr);
3320 	vattr.va_atime = ts[0];
3321 	vattr.va_mtime = ts[1];
3322 	if (setbirthtime)
3323 		vattr.va_birthtime = ts[1];
3324 	if (numtimes > 2)
3325 		vattr.va_birthtime = ts[2];
3326 	if (nullflag)
3327 		vattr.va_vaflags |= VA_UTIMES_NULL;
3328 #ifdef MAC
3329 	error = mac_vnode_check_setutimes(td->td_ucred, vp, vattr.va_atime,
3330 	    vattr.va_mtime);
3331 #endif
3332 	if (error == 0)
3333 		error = VOP_SETATTR(vp, &vattr, td->td_ucred);
3334 	VOP_UNLOCK(vp);
3335 	vn_finished_write(mp);
3336 	return (error);
3337 }
3338 
3339 /*
3340  * Set the access and modification times of a file.
3341  */
3342 #ifndef _SYS_SYSPROTO_H_
3343 struct utimes_args {
3344 	char	*path;
3345 	struct	timeval *tptr;
3346 };
3347 #endif
3348 int
sys_utimes(struct thread * td,struct utimes_args * uap)3349 sys_utimes(struct thread *td, struct utimes_args *uap)
3350 {
3351 
3352 	return (kern_utimesat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
3353 	    uap->tptr, UIO_USERSPACE));
3354 }
3355 
3356 #ifndef _SYS_SYSPROTO_H_
3357 struct futimesat_args {
3358 	int fd;
3359 	const char * path;
3360 	const struct timeval * times;
3361 };
3362 #endif
3363 int
sys_futimesat(struct thread * td,struct futimesat_args * uap)3364 sys_futimesat(struct thread *td, struct futimesat_args *uap)
3365 {
3366 
3367 	return (kern_utimesat(td, uap->fd, uap->path, UIO_USERSPACE,
3368 	    uap->times, UIO_USERSPACE));
3369 }
3370 
3371 int
kern_utimesat(struct thread * td,int fd,const char * path,enum uio_seg pathseg,const struct timeval * tptr,enum uio_seg tptrseg)3372 kern_utimesat(struct thread *td, int fd, const char *path,
3373     enum uio_seg pathseg, const struct timeval *tptr, enum uio_seg tptrseg)
3374 {
3375 	struct nameidata nd;
3376 	struct timespec ts[2];
3377 	int error;
3378 
3379 	if ((error = getutimes(tptr, tptrseg, ts)) != 0)
3380 		return (error);
3381 	NDINIT_ATRIGHTS(&nd, LOOKUP, FOLLOW | AUDITVNODE1, pathseg, path, fd,
3382 	    &cap_futimes_rights);
3383 
3384 	if ((error = namei(&nd)) != 0)
3385 		return (error);
3386 	NDFREE_PNBUF(&nd);
3387 	error = setutimes(td, nd.ni_vp, ts, 2, tptr == NULL);
3388 	vrele(nd.ni_vp);
3389 	return (error);
3390 }
3391 
3392 /*
3393  * Set the access and modification times of a file.
3394  */
3395 #ifndef _SYS_SYSPROTO_H_
3396 struct lutimes_args {
3397 	char	*path;
3398 	struct	timeval *tptr;
3399 };
3400 #endif
3401 int
sys_lutimes(struct thread * td,struct lutimes_args * uap)3402 sys_lutimes(struct thread *td, struct lutimes_args *uap)
3403 {
3404 
3405 	return (kern_lutimes(td, uap->path, UIO_USERSPACE, uap->tptr,
3406 	    UIO_USERSPACE));
3407 }
3408 
3409 int
kern_lutimes(struct thread * td,const char * path,enum uio_seg pathseg,const struct timeval * tptr,enum uio_seg tptrseg)3410 kern_lutimes(struct thread *td, const char *path, enum uio_seg pathseg,
3411     const struct timeval *tptr, enum uio_seg tptrseg)
3412 {
3413 	struct timespec ts[2];
3414 	struct nameidata nd;
3415 	int error;
3416 
3417 	if ((error = getutimes(tptr, tptrseg, ts)) != 0)
3418 		return (error);
3419 	NDINIT(&nd, LOOKUP, NOFOLLOW | AUDITVNODE1, pathseg, path);
3420 	if ((error = namei(&nd)) != 0)
3421 		return (error);
3422 	NDFREE_PNBUF(&nd);
3423 	error = setutimes(td, nd.ni_vp, ts, 2, tptr == NULL);
3424 	vrele(nd.ni_vp);
3425 	return (error);
3426 }
3427 
3428 /*
3429  * Set the access and modification times of a file.
3430  */
3431 #ifndef _SYS_SYSPROTO_H_
3432 struct futimes_args {
3433 	int	fd;
3434 	struct	timeval *tptr;
3435 };
3436 #endif
3437 int
sys_futimes(struct thread * td,struct futimes_args * uap)3438 sys_futimes(struct thread *td, struct futimes_args *uap)
3439 {
3440 
3441 	return (kern_futimes(td, uap->fd, uap->tptr, UIO_USERSPACE));
3442 }
3443 
3444 int
kern_futimes(struct thread * td,int fd,const struct timeval * tptr,enum uio_seg tptrseg)3445 kern_futimes(struct thread *td, int fd, const struct timeval *tptr,
3446     enum uio_seg tptrseg)
3447 {
3448 	struct timespec ts[2];
3449 	struct file *fp;
3450 	int error;
3451 
3452 	AUDIT_ARG_FD(fd);
3453 	error = getutimes(tptr, tptrseg, ts);
3454 	if (error != 0)
3455 		return (error);
3456 	error = getvnode(td, fd, &cap_futimes_rights, &fp);
3457 	if (error != 0)
3458 		return (error);
3459 #ifdef AUDIT
3460 	if (AUDITING_TD(td)) {
3461 		vn_lock(fp->f_vnode, LK_SHARED | LK_RETRY);
3462 		AUDIT_ARG_VNODE1(fp->f_vnode);
3463 		VOP_UNLOCK(fp->f_vnode);
3464 	}
3465 #endif
3466 	error = setutimes(td, fp->f_vnode, ts, 2, tptr == NULL);
3467 	fdrop(fp, td);
3468 	return (error);
3469 }
3470 
3471 int
sys_futimens(struct thread * td,struct futimens_args * uap)3472 sys_futimens(struct thread *td, struct futimens_args *uap)
3473 {
3474 
3475 	return (kern_futimens(td, uap->fd, uap->times, UIO_USERSPACE));
3476 }
3477 
3478 int
kern_futimens(struct thread * td,int fd,const struct timespec * tptr,enum uio_seg tptrseg)3479 kern_futimens(struct thread *td, int fd, const struct timespec *tptr,
3480     enum uio_seg tptrseg)
3481 {
3482 	struct timespec ts[2];
3483 	struct file *fp;
3484 	int error, flags;
3485 
3486 	AUDIT_ARG_FD(fd);
3487 	error = getutimens(tptr, tptrseg, ts, &flags);
3488 	if (error != 0)
3489 		return (error);
3490 	if (flags & UTIMENS_EXIT)
3491 		return (0);
3492 	error = getvnode(td, fd, &cap_futimes_rights, &fp);
3493 	if (error != 0)
3494 		return (error);
3495 #ifdef AUDIT
3496 	if (AUDITING_TD(td)) {
3497 		vn_lock(fp->f_vnode, LK_SHARED | LK_RETRY);
3498 		AUDIT_ARG_VNODE1(fp->f_vnode);
3499 		VOP_UNLOCK(fp->f_vnode);
3500 	}
3501 #endif
3502 	error = setutimes(td, fp->f_vnode, ts, 2, flags & UTIMENS_NULL);
3503 	fdrop(fp, td);
3504 	return (error);
3505 }
3506 
3507 int
sys_utimensat(struct thread * td,struct utimensat_args * uap)3508 sys_utimensat(struct thread *td, struct utimensat_args *uap)
3509 {
3510 
3511 	return (kern_utimensat(td, uap->fd, uap->path, UIO_USERSPACE,
3512 	    uap->times, UIO_USERSPACE, uap->flag));
3513 }
3514 
3515 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)3516 kern_utimensat(struct thread *td, int fd, const char *path,
3517     enum uio_seg pathseg, const struct timespec *tptr, enum uio_seg tptrseg,
3518     int flag)
3519 {
3520 	struct nameidata nd;
3521 	struct timespec ts[2];
3522 	int error, flags;
3523 
3524 	if ((flag & ~(AT_SYMLINK_NOFOLLOW | AT_RESOLVE_BENEATH |
3525 	    AT_EMPTY_PATH)) != 0)
3526 		return (EINVAL);
3527 
3528 	if ((error = getutimens(tptr, tptrseg, ts, &flags)) != 0)
3529 		return (error);
3530 	NDINIT_ATRIGHTS(&nd, LOOKUP, at2cnpflags(flag, AT_SYMLINK_NOFOLLOW |
3531 	    AT_RESOLVE_BENEATH | AT_EMPTY_PATH) | AUDITVNODE1,
3532 	    pathseg, path, fd, &cap_futimes_rights);
3533 	if ((error = namei(&nd)) != 0)
3534 		return (error);
3535 	/*
3536 	 * We are allowed to call namei() regardless of 2xUTIME_OMIT.
3537 	 * POSIX states:
3538 	 * "If both tv_nsec fields are UTIME_OMIT... EACCESS may be detected."
3539 	 * "Search permission is denied by a component of the path prefix."
3540 	 */
3541 	NDFREE_PNBUF(&nd);
3542 	if ((flags & UTIMENS_EXIT) == 0)
3543 		error = setutimes(td, nd.ni_vp, ts, 2, flags & UTIMENS_NULL);
3544 	vrele(nd.ni_vp);
3545 	return (error);
3546 }
3547 
3548 /*
3549  * Truncate a file given its path name.
3550  */
3551 #ifndef _SYS_SYSPROTO_H_
3552 struct truncate_args {
3553 	char	*path;
3554 	int	pad;
3555 	off_t	length;
3556 };
3557 #endif
3558 int
sys_truncate(struct thread * td,struct truncate_args * uap)3559 sys_truncate(struct thread *td, struct truncate_args *uap)
3560 {
3561 
3562 	return (kern_truncate(td, uap->path, UIO_USERSPACE, uap->length));
3563 }
3564 
3565 int
kern_truncate(struct thread * td,const char * path,enum uio_seg pathseg,off_t length)3566 kern_truncate(struct thread *td, const char *path, enum uio_seg pathseg,
3567     off_t length)
3568 {
3569 	struct mount *mp;
3570 	struct vnode *vp;
3571 	void *rl_cookie;
3572 	struct nameidata nd;
3573 	int error;
3574 
3575 	if (length < 0)
3576 		return (EINVAL);
3577 	NDPREINIT(&nd);
3578 retry:
3579 	NDINIT(&nd, LOOKUP, FOLLOW | AUDITVNODE1, pathseg, path);
3580 	if ((error = namei(&nd)) != 0)
3581 		return (error);
3582 	vp = nd.ni_vp;
3583 	NDFREE_PNBUF(&nd);
3584 	rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
3585 	if ((error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH)) != 0) {
3586 		vn_rangelock_unlock(vp, rl_cookie);
3587 		vrele(vp);
3588 		return (error);
3589 	}
3590 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
3591 	if (vp->v_type == VDIR) {
3592 		error = EISDIR;
3593 		goto out;
3594 	}
3595 #ifdef MAC
3596 	error = mac_vnode_check_write(td->td_ucred, NOCRED, vp);
3597 	if (error != 0)
3598 		goto out;
3599 #endif
3600 	error = VOP_ACCESS(vp, VWRITE, td->td_ucred, td);
3601 	if (error != 0)
3602 		goto out;
3603 
3604 	error = vn_truncate_locked(vp, length, false, td->td_ucred);
3605 out:
3606 	VOP_UNLOCK(vp);
3607 	vn_finished_write(mp);
3608 	vn_rangelock_unlock(vp, rl_cookie);
3609 	vrele(vp);
3610 	if (error == ERELOOKUP)
3611 		goto retry;
3612 	return (error);
3613 }
3614 
3615 #if defined(COMPAT_43)
3616 /*
3617  * Truncate a file given its path name.
3618  */
3619 #ifndef _SYS_SYSPROTO_H_
3620 struct otruncate_args {
3621 	char	*path;
3622 	long	length;
3623 };
3624 #endif
3625 int
otruncate(struct thread * td,struct otruncate_args * uap)3626 otruncate(struct thread *td, struct otruncate_args *uap)
3627 {
3628 
3629 	return (kern_truncate(td, uap->path, UIO_USERSPACE, uap->length));
3630 }
3631 #endif /* COMPAT_43 */
3632 
3633 #if defined(COMPAT_FREEBSD6)
3634 /* Versions with the pad argument */
3635 int
freebsd6_truncate(struct thread * td,struct freebsd6_truncate_args * uap)3636 freebsd6_truncate(struct thread *td, struct freebsd6_truncate_args *uap)
3637 {
3638 
3639 	return (kern_truncate(td, uap->path, UIO_USERSPACE, uap->length));
3640 }
3641 
3642 int
freebsd6_ftruncate(struct thread * td,struct freebsd6_ftruncate_args * uap)3643 freebsd6_ftruncate(struct thread *td, struct freebsd6_ftruncate_args *uap)
3644 {
3645 
3646 	return (kern_ftruncate(td, uap->fd, uap->length));
3647 }
3648 #endif
3649 
3650 int
kern_fsync(struct thread * td,int fd,bool fullsync)3651 kern_fsync(struct thread *td, int fd, bool fullsync)
3652 {
3653 	struct vnode *vp;
3654 	struct mount *mp;
3655 	struct file *fp;
3656 	int error;
3657 
3658 	AUDIT_ARG_FD(fd);
3659 	error = getvnode(td, fd, &cap_fsync_rights, &fp);
3660 	if (error != 0)
3661 		return (error);
3662 	vp = fp->f_vnode;
3663 #if 0
3664 	if (!fullsync)
3665 		/* XXXKIB: compete outstanding aio writes */;
3666 #endif
3667 retry:
3668 	error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH);
3669 	if (error != 0)
3670 		goto drop;
3671 	vn_lock(vp, vn_lktype_write(mp, vp) | LK_RETRY);
3672 	AUDIT_ARG_VNODE1(vp);
3673 	vnode_pager_clean_async(vp);
3674 	error = fullsync ? VOP_FSYNC(vp, MNT_WAIT, td) : VOP_FDATASYNC(vp, td);
3675 	VOP_UNLOCK(vp);
3676 	vn_finished_write(mp);
3677 	if (error == ERELOOKUP)
3678 		goto retry;
3679 drop:
3680 	fdrop(fp, td);
3681 	return (error);
3682 }
3683 
3684 /*
3685  * Sync an open file.
3686  */
3687 #ifndef _SYS_SYSPROTO_H_
3688 struct fsync_args {
3689 	int	fd;
3690 };
3691 #endif
3692 int
sys_fsync(struct thread * td,struct fsync_args * uap)3693 sys_fsync(struct thread *td, struct fsync_args *uap)
3694 {
3695 
3696 	return (kern_fsync(td, uap->fd, true));
3697 }
3698 
3699 int
sys_fdatasync(struct thread * td,struct fdatasync_args * uap)3700 sys_fdatasync(struct thread *td, struct fdatasync_args *uap)
3701 {
3702 
3703 	return (kern_fsync(td, uap->fd, false));
3704 }
3705 
3706 /*
3707  * Rename files.  Source and destination must either both be directories, or
3708  * both not be directories.  If target is a directory, it must be empty.
3709  */
3710 #ifndef _SYS_SYSPROTO_H_
3711 struct rename_args {
3712 	char	*from;
3713 	char	*to;
3714 };
3715 #endif
3716 int
sys_rename(struct thread * td,struct rename_args * uap)3717 sys_rename(struct thread *td, struct rename_args *uap)
3718 {
3719 
3720 	return (kern_renameat(td, AT_FDCWD, uap->from, AT_FDCWD,
3721 	    uap->to, UIO_USERSPACE));
3722 }
3723 
3724 #ifndef _SYS_SYSPROTO_H_
3725 struct renameat_args {
3726 	int	oldfd;
3727 	char	*old;
3728 	int	newfd;
3729 	char	*new;
3730 };
3731 #endif
3732 int
sys_renameat(struct thread * td,struct renameat_args * uap)3733 sys_renameat(struct thread *td, struct renameat_args *uap)
3734 {
3735 
3736 	return (kern_renameat(td, uap->oldfd, uap->old, uap->newfd, uap->new,
3737 	    UIO_USERSPACE));
3738 }
3739 
3740 #ifdef MAC
3741 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)3742 kern_renameat_mac(struct thread *td, int oldfd, const char *old, int newfd,
3743     const char *new, enum uio_seg pathseg, struct nameidata *fromnd)
3744 {
3745 	int error;
3746 
3747 	NDINIT_ATRIGHTS(fromnd, DELETE, LOCKPARENT | LOCKLEAF | AUDITVNODE1,
3748 	    pathseg, old, oldfd, &cap_renameat_source_rights);
3749 	if ((error = namei(fromnd)) != 0)
3750 		return (error);
3751 	error = mac_vnode_check_rename_from(td->td_ucred, fromnd->ni_dvp,
3752 	    fromnd->ni_vp, &fromnd->ni_cnd);
3753 	VOP_UNLOCK(fromnd->ni_dvp);
3754 	if (fromnd->ni_dvp != fromnd->ni_vp)
3755 		VOP_UNLOCK(fromnd->ni_vp);
3756 	if (error != 0) {
3757 		NDFREE_PNBUF(fromnd);
3758 		vrele(fromnd->ni_dvp);
3759 		vrele(fromnd->ni_vp);
3760 	}
3761 	return (error);
3762 }
3763 #endif
3764 
3765 int
kern_renameat(struct thread * td,int oldfd,const char * old,int newfd,const char * new,enum uio_seg pathseg)3766 kern_renameat(struct thread *td, int oldfd, const char *old, int newfd,
3767     const char *new, enum uio_seg pathseg)
3768 {
3769 	struct mount *mp = NULL;
3770 	struct vnode *tvp, *fvp, *tdvp;
3771 	struct nameidata fromnd, tond;
3772 	uint64_t tondflags;
3773 	int error;
3774 	short irflag;
3775 
3776 again:
3777 	bwillwrite();
3778 #ifdef MAC
3779 	if (mac_vnode_check_rename_from_enabled()) {
3780 		error = kern_renameat_mac(td, oldfd, old, newfd, new, pathseg,
3781 		    &fromnd);
3782 		if (error != 0)
3783 			return (error);
3784 	} else {
3785 #endif
3786 	NDINIT_ATRIGHTS(&fromnd, DELETE, WANTPARENT | AUDITVNODE1,
3787 	    pathseg, old, oldfd, &cap_renameat_source_rights);
3788 	if ((error = namei(&fromnd)) != 0)
3789 		return (error);
3790 #ifdef MAC
3791 	}
3792 #endif
3793 	fvp = fromnd.ni_vp;
3794 	tondflags = LOCKPARENT | LOCKLEAF | NOCACHE | AUDITVNODE2;
3795 	if (fromnd.ni_vp->v_type == VDIR)
3796 		tondflags |= WILLBEDIR;
3797 	NDINIT_ATRIGHTS(&tond, RENAME, tondflags, pathseg, new, newfd,
3798 	    &cap_renameat_target_rights);
3799 	if ((error = namei(&tond)) != 0) {
3800 		/* Translate error code for rename("dir1", "dir2/."). */
3801 		if (error == EISDIR && fvp->v_type == VDIR)
3802 			error = EINVAL;
3803 		NDFREE_PNBUF(&fromnd);
3804 		vrele(fromnd.ni_dvp);
3805 		vrele(fvp);
3806 		goto out1;
3807 	}
3808 	tdvp = tond.ni_dvp;
3809 	tvp = tond.ni_vp;
3810 	error = vn_start_write(fvp, &mp, V_NOWAIT);
3811 	if (error != 0) {
3812 		NDFREE_PNBUF(&fromnd);
3813 		NDFREE_PNBUF(&tond);
3814 		if (tvp != NULL)
3815 			vput(tvp);
3816 		if (tdvp == tvp)
3817 			vrele(tdvp);
3818 		else
3819 			vput(tdvp);
3820 		vrele(fromnd.ni_dvp);
3821 		vrele(fvp);
3822 		error = vn_start_write(NULL, &mp, V_XSLEEP | V_PCATCH);
3823 		if (error != 0)
3824 			return (error);
3825 		goto again;
3826 	}
3827 	irflag = vn_irflag_read(fvp);
3828 	if (((irflag & VIRF_NAMEDATTR) != 0 && tdvp != fromnd.ni_dvp) ||
3829 	    (irflag & VIRF_NAMEDDIR) != 0) {
3830 		error = EINVAL;
3831 		goto out;
3832 	}
3833 	if (tvp != NULL) {
3834 		if (fvp->v_type == VDIR && tvp->v_type != VDIR) {
3835 			error = ENOTDIR;
3836 			goto out;
3837 		} else if (fvp->v_type != VDIR && tvp->v_type == VDIR) {
3838 			error = EISDIR;
3839 			goto out;
3840 		}
3841 #ifdef CAPABILITIES
3842 		if (newfd != AT_FDCWD && (tond.ni_resflags & NIRES_ABS) == 0) {
3843 			/*
3844 			 * If the target already exists we require CAP_UNLINKAT
3845 			 * from 'newfd', when newfd was used for the lookup.
3846 			 */
3847 			error = cap_check(&tond.ni_filecaps.fc_rights,
3848 			    &cap_unlinkat_rights);
3849 			if (error != 0)
3850 				goto out;
3851 		}
3852 #endif
3853 	}
3854 	if (fvp == tdvp) {
3855 		error = EINVAL;
3856 		goto out;
3857 	}
3858 	/*
3859 	 * If the source is the same as the destination (that is, if they
3860 	 * are links to the same vnode), then there is nothing to do.
3861 	 */
3862 	if (fvp == tvp)
3863 		error = ERESTART;
3864 #ifdef MAC
3865 	else
3866 		error = mac_vnode_check_rename_to(td->td_ucred, tdvp,
3867 		    tond.ni_vp, fromnd.ni_dvp == tdvp, &tond.ni_cnd);
3868 #endif
3869 out:
3870 	if (error == 0) {
3871 		error = VOP_RENAME(fromnd.ni_dvp, fromnd.ni_vp, &fromnd.ni_cnd,
3872 		    tond.ni_dvp, tond.ni_vp, &tond.ni_cnd);
3873 		NDFREE_PNBUF(&fromnd);
3874 		NDFREE_PNBUF(&tond);
3875 	} else {
3876 		NDFREE_PNBUF(&fromnd);
3877 		NDFREE_PNBUF(&tond);
3878 		if (tvp != NULL)
3879 			vput(tvp);
3880 		if (tdvp == tvp)
3881 			vrele(tdvp);
3882 		else
3883 			vput(tdvp);
3884 		vrele(fromnd.ni_dvp);
3885 		vrele(fvp);
3886 	}
3887 	vn_finished_write(mp);
3888 out1:
3889 	if (error == ERESTART)
3890 		return (0);
3891 	if (error == ERELOOKUP)
3892 		goto again;
3893 	return (error);
3894 }
3895 
3896 /*
3897  * Make a directory file.
3898  */
3899 #ifndef _SYS_SYSPROTO_H_
3900 struct mkdir_args {
3901 	char	*path;
3902 	int	mode;
3903 };
3904 #endif
3905 int
sys_mkdir(struct thread * td,struct mkdir_args * uap)3906 sys_mkdir(struct thread *td, struct mkdir_args *uap)
3907 {
3908 
3909 	return (kern_mkdirat(td, AT_FDCWD, uap->path, UIO_USERSPACE,
3910 	    uap->mode));
3911 }
3912 
3913 #ifndef _SYS_SYSPROTO_H_
3914 struct mkdirat_args {
3915 	int	fd;
3916 	char	*path;
3917 	mode_t	mode;
3918 };
3919 #endif
3920 int
sys_mkdirat(struct thread * td,struct mkdirat_args * uap)3921 sys_mkdirat(struct thread *td, struct mkdirat_args *uap)
3922 {
3923 
3924 	return (kern_mkdirat(td, uap->fd, uap->path, UIO_USERSPACE, uap->mode));
3925 }
3926 
3927 int
kern_mkdirat(struct thread * td,int fd,const char * path,enum uio_seg segflg,int mode)3928 kern_mkdirat(struct thread *td, int fd, const char *path, enum uio_seg segflg,
3929     int mode)
3930 {
3931 	struct mount *mp;
3932 	struct vattr vattr;
3933 	struct nameidata nd;
3934 	int error;
3935 
3936 	AUDIT_ARG_MODE(mode);
3937 	NDPREINIT(&nd);
3938 restart:
3939 	bwillwrite();
3940 	NDINIT_ATRIGHTS(&nd, CREATE, LOCKPARENT | AUDITVNODE1 |
3941 	    NC_NOMAKEENTRY | NC_KEEPPOSENTRY | FAILIFEXISTS | WILLBEDIR,
3942 	    segflg, path, fd, &cap_mkdirat_rights);
3943 	if ((error = namei(&nd)) != 0)
3944 		return (error);
3945 	if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
3946 		NDFREE_PNBUF(&nd);
3947 		vput(nd.ni_dvp);
3948 		if ((error = vn_start_write(NULL, &mp, V_XSLEEP | V_PCATCH)) != 0)
3949 			return (error);
3950 		goto restart;
3951 	}
3952 	if ((vn_irflag_read(nd.ni_dvp) & VIRF_NAMEDDIR) != 0) {
3953 		error = EINVAL;
3954 		goto out;
3955 	}
3956 	VATTR_NULL(&vattr);
3957 	vattr.va_type = VDIR;
3958 	vattr.va_mode = (mode & ACCESSPERMS) &~ td->td_proc->p_pd->pd_cmask;
3959 #ifdef MAC
3960 	error = mac_vnode_check_create(td->td_ucred, nd.ni_dvp, &nd.ni_cnd,
3961 	    &vattr);
3962 	if (error != 0)
3963 		goto out;
3964 #endif
3965 	error = VOP_MKDIR(nd.ni_dvp, &nd.ni_vp, &nd.ni_cnd, &vattr);
3966 out:
3967 	NDFREE_PNBUF(&nd);
3968 	VOP_VPUT_PAIR(nd.ni_dvp, error == 0 ? &nd.ni_vp : NULL, true);
3969 	vn_finished_write(mp);
3970 	if (error == ERELOOKUP)
3971 		goto restart;
3972 	return (error);
3973 }
3974 
3975 /*
3976  * Remove a directory file.
3977  */
3978 #ifndef _SYS_SYSPROTO_H_
3979 struct rmdir_args {
3980 	char	*path;
3981 };
3982 #endif
3983 int
sys_rmdir(struct thread * td,struct rmdir_args * uap)3984 sys_rmdir(struct thread *td, struct rmdir_args *uap)
3985 {
3986 
3987 	return (kern_frmdirat(td, AT_FDCWD, uap->path, FD_NONE, UIO_USERSPACE,
3988 	    0));
3989 }
3990 
3991 int
kern_frmdirat(struct thread * td,int dfd,const char * path,int fd,enum uio_seg pathseg,int flag)3992 kern_frmdirat(struct thread *td, int dfd, const char *path, int fd,
3993     enum uio_seg pathseg, int flag)
3994 {
3995 	struct mount *mp;
3996 	struct vnode *vp;
3997 	struct file *fp;
3998 	struct nameidata nd;
3999 	cap_rights_t rights;
4000 	int error;
4001 
4002 	fp = NULL;
4003 	if (fd != FD_NONE) {
4004 		error = getvnode(td, fd, cap_rights_init_one(&rights,
4005 		    CAP_LOOKUP), &fp);
4006 		if (error != 0)
4007 			return (error);
4008 	}
4009 
4010 	NDPREINIT(&nd);
4011 restart:
4012 	bwillwrite();
4013 	NDINIT_ATRIGHTS(&nd, DELETE, LOCKPARENT | LOCKLEAF | AUDITVNODE1 |
4014 	    at2cnpflags(flag, AT_RESOLVE_BENEATH),
4015 	    pathseg, path, dfd, &cap_unlinkat_rights);
4016 	if ((error = namei(&nd)) != 0)
4017 		goto fdout;
4018 	vp = nd.ni_vp;
4019 	if (vp->v_type != VDIR) {
4020 		error = ENOTDIR;
4021 		goto out;
4022 	}
4023 	/*
4024 	 * No rmdir "." please.
4025 	 */
4026 	if (nd.ni_dvp == vp) {
4027 		error = EINVAL;
4028 		goto out;
4029 	}
4030 	/*
4031 	 * The root of a mounted filesystem cannot be deleted.
4032 	 */
4033 	if (vp->v_vflag & VV_ROOT) {
4034 		error = EBUSY;
4035 		goto out;
4036 	}
4037 
4038 	if (fp != NULL && fp->f_vnode != vp) {
4039 		if (VN_IS_DOOMED(fp->f_vnode))
4040 			error = EBADF;
4041 		else
4042 			error = EDEADLK;
4043 		goto out;
4044 	}
4045 
4046 #ifdef MAC
4047 	error = mac_vnode_check_unlink(td->td_ucred, nd.ni_dvp, vp,
4048 	    &nd.ni_cnd);
4049 	if (error != 0)
4050 		goto out;
4051 #endif
4052 	if (vn_start_write(nd.ni_dvp, &mp, V_NOWAIT) != 0) {
4053 		NDFREE_PNBUF(&nd);
4054 		vput(vp);
4055 		if (nd.ni_dvp == vp)
4056 			vrele(nd.ni_dvp);
4057 		else
4058 			vput(nd.ni_dvp);
4059 		if ((error = vn_start_write(NULL, &mp, V_XSLEEP | V_PCATCH)) != 0)
4060 			goto fdout;
4061 		goto restart;
4062 	}
4063 	error = VOP_RMDIR(nd.ni_dvp, nd.ni_vp, &nd.ni_cnd);
4064 	vn_finished_write(mp);
4065 out:
4066 	NDFREE_PNBUF(&nd);
4067 	vput(vp);
4068 	if (nd.ni_dvp == vp)
4069 		vrele(nd.ni_dvp);
4070 	else
4071 		vput(nd.ni_dvp);
4072 	if (error == ERELOOKUP)
4073 		goto restart;
4074 fdout:
4075 	if (fp != NULL)
4076 		fdrop(fp, td);
4077 	return (error);
4078 }
4079 
4080 #if defined(COMPAT_43) || defined(COMPAT_FREEBSD11)
4081 int
freebsd11_kern_getdirentries(struct thread * td,int fd,char * ubuf,u_int count,long * basep,void (* func)(struct freebsd11_dirent *))4082 freebsd11_kern_getdirentries(struct thread *td, int fd, char *ubuf, u_int count,
4083     long *basep, void (*func)(struct freebsd11_dirent *))
4084 {
4085 	struct freebsd11_dirent dstdp;
4086 	struct dirent *dp, *edp;
4087 	char *dirbuf;
4088 	off_t base;
4089 	ssize_t resid, ucount;
4090 	int error;
4091 
4092 	/* XXX arbitrary sanity limit on `count'. */
4093 	count = min(count, 64 * 1024);
4094 
4095 	dirbuf = malloc(count, M_TEMP, M_WAITOK);
4096 
4097 	error = kern_getdirentries(td, fd, dirbuf, count, &base, &resid,
4098 	    UIO_SYSSPACE);
4099 	if (error != 0)
4100 		goto done;
4101 	if (basep != NULL)
4102 		*basep = base;
4103 
4104 	ucount = 0;
4105 	for (dp = (struct dirent *)dirbuf,
4106 	    edp = (struct dirent *)&dirbuf[count - resid];
4107 	    ucount < count && dp < edp; ) {
4108 		if (dp->d_reclen == 0)
4109 			break;
4110 		MPASS(dp->d_reclen >= _GENERIC_DIRLEN(0));
4111 		if (dp->d_namlen >= sizeof(dstdp.d_name))
4112 			continue;
4113 		dstdp.d_type = dp->d_type;
4114 		dstdp.d_namlen = dp->d_namlen;
4115 		dstdp.d_fileno = dp->d_fileno;		/* truncate */
4116 		if (dstdp.d_fileno != dp->d_fileno) {
4117 			switch (ino64_trunc_error) {
4118 			default:
4119 			case 0:
4120 				break;
4121 			case 1:
4122 				error = EOVERFLOW;
4123 				goto done;
4124 			case 2:
4125 				dstdp.d_fileno = UINT32_MAX;
4126 				break;
4127 			}
4128 		}
4129 		dstdp.d_reclen = sizeof(dstdp) - sizeof(dstdp.d_name) +
4130 		    ((dp->d_namlen + 1 + 3) &~ 3);
4131 		bcopy(dp->d_name, dstdp.d_name, dstdp.d_namlen);
4132 		bzero(dstdp.d_name + dstdp.d_namlen,
4133 		    dstdp.d_reclen - offsetof(struct freebsd11_dirent, d_name) -
4134 		    dstdp.d_namlen);
4135 		MPASS(dstdp.d_reclen <= dp->d_reclen);
4136 		MPASS(ucount + dstdp.d_reclen <= count);
4137 		if (func != NULL)
4138 			func(&dstdp);
4139 		error = copyout(&dstdp, ubuf + ucount, dstdp.d_reclen);
4140 		if (error != 0)
4141 			break;
4142 		dp = (struct dirent *)((char *)dp + dp->d_reclen);
4143 		ucount += dstdp.d_reclen;
4144 	}
4145 
4146 done:
4147 	free(dirbuf, M_TEMP);
4148 	if (error == 0)
4149 		td->td_retval[0] = ucount;
4150 	return (error);
4151 }
4152 #endif /* COMPAT */
4153 
4154 #ifdef COMPAT_43
4155 static void
ogetdirentries_cvt(struct freebsd11_dirent * dp)4156 ogetdirentries_cvt(struct freebsd11_dirent *dp)
4157 {
4158 #if (BYTE_ORDER == LITTLE_ENDIAN)
4159 	/*
4160 	 * The expected low byte of dp->d_namlen is our dp->d_type.
4161 	 * The high MBZ byte of dp->d_namlen is our dp->d_namlen.
4162 	 */
4163 	dp->d_type = dp->d_namlen;
4164 	dp->d_namlen = 0;
4165 #else
4166 	/*
4167 	 * The dp->d_type is the high byte of the expected dp->d_namlen,
4168 	 * so must be zero'ed.
4169 	 */
4170 	dp->d_type = 0;
4171 #endif
4172 }
4173 
4174 /*
4175  * Read a block of directory entries in a filesystem independent format.
4176  */
4177 #ifndef _SYS_SYSPROTO_H_
4178 struct ogetdirentries_args {
4179 	int	fd;
4180 	char	*buf;
4181 	u_int	count;
4182 	long	*basep;
4183 };
4184 #endif
4185 int
ogetdirentries(struct thread * td,struct ogetdirentries_args * uap)4186 ogetdirentries(struct thread *td, struct ogetdirentries_args *uap)
4187 {
4188 	long loff;
4189 	int error;
4190 
4191 	error = kern_ogetdirentries(td, uap, &loff);
4192 	if (error == 0)
4193 		error = copyout(&loff, uap->basep, sizeof(long));
4194 	return (error);
4195 }
4196 
4197 int
kern_ogetdirentries(struct thread * td,struct ogetdirentries_args * uap,long * ploff)4198 kern_ogetdirentries(struct thread *td, struct ogetdirentries_args *uap,
4199     long *ploff)
4200 {
4201 	long base;
4202 	int error;
4203 
4204 	/* XXX arbitrary sanity limit on `count'. */
4205 	if (uap->count > 64 * 1024)
4206 		return (EINVAL);
4207 
4208 	error = freebsd11_kern_getdirentries(td, uap->fd, uap->buf, uap->count,
4209 	    &base, ogetdirentries_cvt);
4210 
4211 	if (error == 0 && uap->basep != NULL)
4212 		error = copyout(&base, uap->basep, sizeof(long));
4213 
4214 	return (error);
4215 }
4216 #endif /* COMPAT_43 */
4217 
4218 #if defined(COMPAT_FREEBSD11)
4219 #ifndef _SYS_SYSPROTO_H_
4220 struct freebsd11_getdirentries_args {
4221 	int	fd;
4222 	char	*buf;
4223 	u_int	count;
4224 	long	*basep;
4225 };
4226 #endif
4227 int
freebsd11_getdirentries(struct thread * td,struct freebsd11_getdirentries_args * uap)4228 freebsd11_getdirentries(struct thread *td,
4229     struct freebsd11_getdirentries_args *uap)
4230 {
4231 	long base;
4232 	int error;
4233 
4234 	error = freebsd11_kern_getdirentries(td, uap->fd, uap->buf, uap->count,
4235 	    &base, NULL);
4236 
4237 	if (error == 0 && uap->basep != NULL)
4238 		error = copyout(&base, uap->basep, sizeof(long));
4239 	return (error);
4240 }
4241 
4242 int
freebsd11_getdents(struct thread * td,struct freebsd11_getdents_args * uap)4243 freebsd11_getdents(struct thread *td, struct freebsd11_getdents_args *uap)
4244 {
4245 	struct freebsd11_getdirentries_args ap;
4246 
4247 	ap.fd = uap->fd;
4248 	ap.buf = uap->buf;
4249 	ap.count = uap->count;
4250 	ap.basep = NULL;
4251 	return (freebsd11_getdirentries(td, &ap));
4252 }
4253 #endif /* COMPAT_FREEBSD11 */
4254 
4255 /*
4256  * Read a block of directory entries in a filesystem independent format.
4257  */
4258 int
sys_getdirentries(struct thread * td,struct getdirentries_args * uap)4259 sys_getdirentries(struct thread *td, struct getdirentries_args *uap)
4260 {
4261 	off_t base;
4262 	int error;
4263 
4264 	error = kern_getdirentries(td, uap->fd, uap->buf, uap->count, &base,
4265 	    NULL, UIO_USERSPACE);
4266 	if (error != 0)
4267 		return (error);
4268 	if (uap->basep != NULL)
4269 		error = copyout(&base, uap->basep, sizeof(off_t));
4270 	return (error);
4271 }
4272 
4273 int
kern_getdirentries(struct thread * td,int fd,char * buf,size_t count,off_t * basep,ssize_t * residp,enum uio_seg bufseg)4274 kern_getdirentries(struct thread *td, int fd, char *buf, size_t count,
4275     off_t *basep, ssize_t *residp, enum uio_seg bufseg)
4276 {
4277 	struct vnode *vp;
4278 	struct file *fp;
4279 	struct uio auio;
4280 	struct iovec aiov;
4281 	off_t loff;
4282 	int error, eofflag;
4283 	off_t foffset;
4284 
4285 	AUDIT_ARG_FD(fd);
4286 	if (count > IOSIZE_MAX)
4287 		return (EINVAL);
4288 	auio.uio_resid = count;
4289 	error = getvnode(td, fd, &cap_read_rights, &fp);
4290 	if (error != 0)
4291 		return (error);
4292 	if ((fp->f_flag & FREAD) == 0) {
4293 		fdrop(fp, td);
4294 		return (EBADF);
4295 	}
4296 	vp = fp->f_vnode;
4297 	foffset = foffset_lock(fp, 0);
4298 unionread:
4299 	if (vp->v_type != VDIR) {
4300 		error = EINVAL;
4301 		goto fail;
4302 	}
4303 	if (__predict_false((vp->v_vflag & VV_UNLINKED) != 0)) {
4304 		error = ENOENT;
4305 		goto fail;
4306 	}
4307 	aiov.iov_base = buf;
4308 	aiov.iov_len = count;
4309 	auio.uio_iov = &aiov;
4310 	auio.uio_iovcnt = 1;
4311 	auio.uio_rw = UIO_READ;
4312 	auio.uio_segflg = bufseg;
4313 	auio.uio_td = td;
4314 	vn_lock(vp, LK_SHARED | LK_RETRY);
4315 	AUDIT_ARG_VNODE1(vp);
4316 	loff = auio.uio_offset = foffset;
4317 #ifdef MAC
4318 	error = mac_vnode_check_readdir(td->td_ucred, vp);
4319 	if (error == 0)
4320 #endif
4321 		error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, NULL,
4322 		    NULL);
4323 	foffset = auio.uio_offset;
4324 	if (error != 0) {
4325 		VOP_UNLOCK(vp);
4326 		goto fail;
4327 	}
4328 	if (count == auio.uio_resid &&
4329 	    (vp->v_vflag & VV_ROOT) &&
4330 	    (vp->v_mount->mnt_flag & MNT_UNION)) {
4331 		struct vnode *tvp = vp;
4332 
4333 		vp = vp->v_mount->mnt_vnodecovered;
4334 		VREF(vp);
4335 		fp->f_vnode = vp;
4336 		foffset = 0;
4337 		vput(tvp);
4338 		goto unionread;
4339 	}
4340 	VOP_UNLOCK(vp);
4341 	*basep = loff;
4342 	if (residp != NULL)
4343 		*residp = auio.uio_resid;
4344 	td->td_retval[0] = count - auio.uio_resid;
4345 fail:
4346 	foffset_unlock(fp, foffset, 0);
4347 	fdrop(fp, td);
4348 	return (error);
4349 }
4350 
4351 /*
4352  * Set the mode mask for creation of filesystem nodes.
4353  */
4354 #ifndef _SYS_SYSPROTO_H_
4355 struct umask_args {
4356 	int	newmask;
4357 };
4358 #endif
4359 int
sys_umask(struct thread * td,struct umask_args * uap)4360 sys_umask(struct thread *td, struct umask_args *uap)
4361 {
4362 	struct pwddesc *pdp;
4363 
4364 	pdp = td->td_proc->p_pd;
4365 	PWDDESC_XLOCK(pdp);
4366 	td->td_retval[0] = pdp->pd_cmask;
4367 	pdp->pd_cmask = uap->newmask & ALLPERMS;
4368 	PWDDESC_XUNLOCK(pdp);
4369 	return (0);
4370 }
4371 
4372 /*
4373  * Void all references to file by ripping underlying filesystem away from
4374  * vnode.
4375  */
4376 #ifndef _SYS_SYSPROTO_H_
4377 struct revoke_args {
4378 	char	*path;
4379 };
4380 #endif
4381 int
sys_revoke(struct thread * td,struct revoke_args * uap)4382 sys_revoke(struct thread *td, struct revoke_args *uap)
4383 {
4384 	struct vnode *vp;
4385 	struct vattr vattr;
4386 	struct nameidata nd;
4387 	int error;
4388 
4389 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, UIO_USERSPACE,
4390 	    uap->path);
4391 	if ((error = namei(&nd)) != 0)
4392 		return (error);
4393 	vp = nd.ni_vp;
4394 	NDFREE_PNBUF(&nd);
4395 	if (vp->v_type != VCHR || vp->v_rdev == NULL) {
4396 		error = EINVAL;
4397 		goto out;
4398 	}
4399 #ifdef MAC
4400 	error = mac_vnode_check_revoke(td->td_ucred, vp);
4401 	if (error != 0)
4402 		goto out;
4403 #endif
4404 	error = VOP_GETATTR(vp, &vattr, td->td_ucred);
4405 	if (error != 0)
4406 		goto out;
4407 	if (td->td_ucred->cr_uid != vattr.va_uid) {
4408 		error = priv_check(td, PRIV_VFS_ADMIN);
4409 		if (error != 0)
4410 			goto out;
4411 	}
4412 	if (devfs_usecount(vp) > 0)
4413 		VOP_REVOKE(vp, REVOKEALL);
4414 out:
4415 	vput(vp);
4416 	return (error);
4417 }
4418 
4419 /*
4420  * This variant of getvnode() allows O_PATH files.  Caller should
4421  * ensure that returned file and vnode are only used for compatible
4422  * semantics.
4423  */
4424 int
getvnode_path(struct thread * td,int fd,const cap_rights_t * rightsp,uint8_t * flagsp,struct file ** fpp)4425 getvnode_path(struct thread *td, int fd, const cap_rights_t *rightsp,
4426     uint8_t *flagsp, struct file **fpp)
4427 {
4428 	struct file *fp;
4429 	int error;
4430 
4431 	error = fget_unlocked_flags(td, fd, rightsp, flagsp, &fp);
4432 	if (error != 0)
4433 		return (error);
4434 
4435 	/*
4436 	 * The file could be not of the vnode type, or it may be not
4437 	 * yet fully initialized, in which case the f_vnode pointer
4438 	 * may be set, but f_ops is still badfileops.  E.g.,
4439 	 * devfs_open() transiently create such situation to
4440 	 * facilitate csw d_fdopen().
4441 	 *
4442 	 * Dupfdopen() handling in kern_openat() installs the
4443 	 * half-baked file into the process descriptor table, allowing
4444 	 * other thread to dereference it. Guard against the race by
4445 	 * checking f_ops.
4446 	 */
4447 	if (__predict_false(fp->f_vnode == NULL || fp->f_ops == &badfileops)) {
4448 		fdrop(fp, td);
4449 		*fpp = NULL;
4450 		return (EINVAL);
4451 	}
4452 
4453 	*fpp = fp;
4454 	return (0);
4455 }
4456 
4457 /*
4458  * Convert a user file descriptor to a kernel file entry and check
4459  * that, if it is a capability, the correct rights are present.
4460  * A reference on the file entry is held upon returning.
4461  */
4462 int
getvnode(struct thread * td,int fd,const cap_rights_t * rightsp,struct file ** fpp)4463 getvnode(struct thread *td, int fd, const cap_rights_t *rightsp,
4464     struct file **fpp)
4465 {
4466 	int error;
4467 
4468 	error = getvnode_path(td, fd, rightsp, NULL, fpp);
4469 	if (__predict_false(error != 0))
4470 		return (error);
4471 
4472 	/*
4473 	 * Filter out O_PATH file descriptors, most getvnode() callers
4474 	 * do not call fo_ methods.
4475 	 */
4476 	if (__predict_false((*fpp)->f_ops == &path_fileops)) {
4477 		fdrop(*fpp, td);
4478 		*fpp = NULL;
4479 		error = EBADF;
4480 	}
4481 
4482 	return (error);
4483 }
4484 
4485 /*
4486  * Get an (NFS) file handle.
4487  */
4488 #ifndef _SYS_SYSPROTO_H_
4489 struct lgetfh_args {
4490 	char *fname;
4491 	fhandle_t *fhp;
4492 };
4493 #endif
4494 int
sys_lgetfh(struct thread * td,struct lgetfh_args * uap)4495 sys_lgetfh(struct thread *td, struct lgetfh_args *uap)
4496 {
4497 
4498 	return (kern_getfhat(td, AT_SYMLINK_NOFOLLOW, AT_FDCWD, uap->fname,
4499 	    UIO_USERSPACE, uap->fhp, UIO_USERSPACE));
4500 }
4501 
4502 #ifndef _SYS_SYSPROTO_H_
4503 struct getfh_args {
4504 	char *fname;
4505 	fhandle_t *fhp;
4506 };
4507 #endif
4508 int
sys_getfh(struct thread * td,struct getfh_args * uap)4509 sys_getfh(struct thread *td, struct getfh_args *uap)
4510 {
4511 
4512 	return (kern_getfhat(td, 0, AT_FDCWD, uap->fname, UIO_USERSPACE,
4513 	    uap->fhp, UIO_USERSPACE));
4514 }
4515 
4516 /*
4517  * syscall for the rpc.lockd to use to translate an open descriptor into
4518  * a NFS file handle.
4519  *
4520  * warning: do not remove the priv_check() call or this becomes one giant
4521  * security hole.
4522  */
4523 #ifndef _SYS_SYSPROTO_H_
4524 struct getfhat_args {
4525 	int fd;
4526 	char *path;
4527 	fhandle_t *fhp;
4528 	int flags;
4529 };
4530 #endif
4531 int
sys_getfhat(struct thread * td,struct getfhat_args * uap)4532 sys_getfhat(struct thread *td, struct getfhat_args *uap)
4533 {
4534 
4535 	return (kern_getfhat(td, uap->flags, uap->fd, uap->path, UIO_USERSPACE,
4536 	    uap->fhp, UIO_USERSPACE));
4537 }
4538 
4539 int
kern_getfhat(struct thread * td,int flags,int fd,const char * path,enum uio_seg pathseg,fhandle_t * fhp,enum uio_seg fhseg)4540 kern_getfhat(struct thread *td, int flags, int fd, const char *path,
4541     enum uio_seg pathseg, fhandle_t *fhp, enum uio_seg fhseg)
4542 {
4543 	struct nameidata nd;
4544 	fhandle_t fh;
4545 	struct vnode *vp;
4546 	int error;
4547 
4548 	if ((flags & ~(AT_SYMLINK_NOFOLLOW | AT_RESOLVE_BENEATH)) != 0)
4549 		return (EINVAL);
4550 	error = priv_check(td, PRIV_VFS_GETFH);
4551 	if (error != 0)
4552 		return (error);
4553 	NDINIT_AT(&nd, LOOKUP, at2cnpflags(flags, AT_SYMLINK_NOFOLLOW |
4554 	    AT_RESOLVE_BENEATH) | LOCKLEAF | AUDITVNODE1, pathseg, path,
4555 	    fd);
4556 	error = namei(&nd);
4557 	if (error != 0)
4558 		return (error);
4559 	NDFREE_PNBUF(&nd);
4560 	vp = nd.ni_vp;
4561 	bzero(&fh, sizeof(fh));
4562 	fh.fh_fsid = vp->v_mount->mnt_stat.f_fsid;
4563 	error = VOP_VPTOFH(vp, &fh.fh_fid);
4564 	vput(vp);
4565 	if (error == 0) {
4566 		if (fhseg == UIO_USERSPACE)
4567 			error = copyout(&fh, fhp, sizeof (fh));
4568 		else
4569 			memcpy(fhp, &fh, sizeof(fh));
4570 	}
4571 	return (error);
4572 }
4573 
4574 #ifndef _SYS_SYSPROTO_H_
4575 struct fhlink_args {
4576 	fhandle_t *fhp;
4577 	const char *to;
4578 };
4579 #endif
4580 int
sys_fhlink(struct thread * td,struct fhlink_args * uap)4581 sys_fhlink(struct thread *td, struct fhlink_args *uap)
4582 {
4583 
4584 	return (kern_fhlinkat(td, AT_FDCWD, uap->to, UIO_USERSPACE, uap->fhp));
4585 }
4586 
4587 #ifndef _SYS_SYSPROTO_H_
4588 struct fhlinkat_args {
4589 	fhandle_t *fhp;
4590 	int tofd;
4591 	const char *to;
4592 };
4593 #endif
4594 int
sys_fhlinkat(struct thread * td,struct fhlinkat_args * uap)4595 sys_fhlinkat(struct thread *td, struct fhlinkat_args *uap)
4596 {
4597 
4598 	return (kern_fhlinkat(td, uap->tofd, uap->to, UIO_USERSPACE, uap->fhp));
4599 }
4600 
4601 static int
kern_fhlinkat(struct thread * td,int fd,const char * path,enum uio_seg pathseg,fhandle_t * fhp)4602 kern_fhlinkat(struct thread *td, int fd, const char *path,
4603     enum uio_seg pathseg, fhandle_t *fhp)
4604 {
4605 	fhandle_t fh;
4606 	struct mount *mp;
4607 	struct vnode *vp;
4608 	int error;
4609 
4610 	error = priv_check(td, PRIV_VFS_GETFH);
4611 	if (error != 0)
4612 		return (error);
4613 	error = copyin(fhp, &fh, sizeof(fh));
4614 	if (error != 0)
4615 		return (error);
4616 	do {
4617 		bwillwrite();
4618 		if ((mp = vfs_busyfs(&fh.fh_fsid)) == NULL)
4619 			return (ESTALE);
4620 		error = VFS_FHTOVP(mp, &fh.fh_fid, LK_SHARED, &vp);
4621 		vfs_unbusy(mp);
4622 		if (error != 0)
4623 			return (error);
4624 		VOP_UNLOCK(vp);
4625 		error = kern_linkat_vp(td, vp, fd, path, pathseg);
4626 	} while (error == EAGAIN || error == ERELOOKUP);
4627 	return (error);
4628 }
4629 
4630 #ifndef _SYS_SYSPROTO_H_
4631 struct fhreadlink_args {
4632 	fhandle_t *fhp;
4633 	char *buf;
4634 	size_t bufsize;
4635 };
4636 #endif
4637 int
sys_fhreadlink(struct thread * td,struct fhreadlink_args * uap)4638 sys_fhreadlink(struct thread *td, struct fhreadlink_args *uap)
4639 {
4640 	fhandle_t fh;
4641 	struct mount *mp;
4642 	struct vnode *vp;
4643 	int error;
4644 
4645 	error = priv_check(td, PRIV_VFS_GETFH);
4646 	if (error != 0)
4647 		return (error);
4648 	if (uap->bufsize > IOSIZE_MAX)
4649 		return (EINVAL);
4650 	error = copyin(uap->fhp, &fh, sizeof(fh));
4651 	if (error != 0)
4652 		return (error);
4653 	if ((mp = vfs_busyfs(&fh.fh_fsid)) == NULL)
4654 		return (ESTALE);
4655 	error = VFS_FHTOVP(mp, &fh.fh_fid, LK_SHARED, &vp);
4656 	vfs_unbusy(mp);
4657 	if (error != 0)
4658 		return (error);
4659 	error = kern_readlink_vp(vp, uap->buf, UIO_USERSPACE, uap->bufsize, td);
4660 	vput(vp);
4661 	return (error);
4662 }
4663 
4664 /*
4665  * syscall for the rpc.lockd to use to translate a NFS file handle into an
4666  * open descriptor.
4667  *
4668  * warning: do not remove the priv_check() call or this becomes one giant
4669  * security hole.
4670  */
4671 #ifndef _SYS_SYSPROTO_H_
4672 struct fhopen_args {
4673 	const struct fhandle *u_fhp;
4674 	int flags;
4675 };
4676 #endif
4677 int
sys_fhopen(struct thread * td,struct fhopen_args * uap)4678 sys_fhopen(struct thread *td, struct fhopen_args *uap)
4679 {
4680 	return (kern_fhopen(td, uap->u_fhp, uap->flags));
4681 }
4682 
4683 int
kern_fhopen(struct thread * td,const struct fhandle * u_fhp,int flags)4684 kern_fhopen(struct thread *td, const struct fhandle *u_fhp, int flags)
4685 {
4686 	struct mount *mp;
4687 	struct vnode *vp;
4688 	struct fhandle fhp;
4689 	struct file *fp;
4690 	int error, indx;
4691 	bool named_attr;
4692 
4693 	error = priv_check(td, PRIV_VFS_FHOPEN);
4694 	if (error != 0)
4695 		return (error);
4696 
4697 	indx = -1;
4698 	if ((flags & O_CREAT) != 0)
4699 		return (EINVAL);
4700 	error = openflags(&flags);
4701 	if (error != 0)
4702 		return (error);
4703 	error = copyin(u_fhp, &fhp, sizeof(fhp));
4704 	if (error != 0)
4705 		return (error);
4706 	/* find the mount point */
4707 	mp = vfs_busyfs(&fhp.fh_fsid);
4708 	if (mp == NULL)
4709 		return (ESTALE);
4710 	/* now give me my vnode, it gets returned to me locked */
4711 	error = VFS_FHTOVP(mp, &fhp.fh_fid, LK_EXCLUSIVE, &vp);
4712 	vfs_unbusy(mp);
4713 	if (error != 0)
4714 		return (error);
4715 
4716 	/*
4717 	 * Check to see if the file handle refers to a named attribute
4718 	 * directory or attribute.  If it does, the O_NAMEDATTR flag
4719 	 * must have been specified.
4720 	 */
4721 	named_attr = (vn_irflag_read(vp) &
4722 	    (VIRF_NAMEDDIR | VIRF_NAMEDATTR)) != 0;
4723 	if ((named_attr && (flags & O_NAMEDATTR) == 0) ||
4724 	    (!named_attr && (flags & O_NAMEDATTR) != 0)) {
4725 		vput(vp);
4726 		return (ENOATTR);
4727 	}
4728 
4729 	error = falloc_noinstall(td, &fp);
4730 	if (error != 0) {
4731 		vput(vp);
4732 		return (error);
4733 	}
4734 	/* Set the flags early so the finit in devfs can pick them up. */
4735 	fp->f_flag = flags & FMASK;
4736 
4737 #ifdef INVARIANTS
4738 	td->td_dupfd = -1;
4739 #endif
4740 	error = vn_open_vnode(vp, flags, td->td_ucred, td, fp);
4741 	if (error != 0) {
4742 		KASSERT(fp->f_ops == &badfileops,
4743 		    ("VOP_OPEN in fhopen() set f_ops"));
4744 		KASSERT(td->td_dupfd < 0,
4745 		    ("fhopen() encountered fdopen()"));
4746 
4747 		vput(vp);
4748 		goto bad;
4749 	}
4750 #ifdef INVARIANTS
4751 	td->td_dupfd = 0;
4752 #endif
4753 	finit_open(fp, vp, flags);
4754 	VOP_UNLOCK(vp);
4755 	if ((flags & O_TRUNC) != 0) {
4756 		error = fo_truncate(fp, 0, td->td_ucred, td);
4757 		if (error != 0)
4758 			goto bad;
4759 	}
4760 
4761 	error = finstall(td, fp, &indx, flags, NULL);
4762 bad:
4763 	fdrop(fp, td);
4764 	td->td_retval[0] = indx;
4765 	return (error);
4766 }
4767 
4768 /*
4769  * Stat an (NFS) file handle.
4770  */
4771 #ifndef _SYS_SYSPROTO_H_
4772 struct fhstat_args {
4773 	struct fhandle *u_fhp;
4774 	struct stat *sb;
4775 };
4776 #endif
4777 int
sys_fhstat(struct thread * td,struct fhstat_args * uap)4778 sys_fhstat(struct thread *td, struct fhstat_args *uap)
4779 {
4780 	struct stat sb;
4781 	struct fhandle fh;
4782 	int error;
4783 
4784 	error = copyin(uap->u_fhp, &fh, sizeof(fh));
4785 	if (error != 0)
4786 		return (error);
4787 	error = kern_fhstat(td, fh, &sb);
4788 	if (error == 0)
4789 		error = copyout(&sb, uap->sb, sizeof(sb));
4790 	return (error);
4791 }
4792 
4793 int
kern_fhstat(struct thread * td,struct fhandle fh,struct stat * sb)4794 kern_fhstat(struct thread *td, struct fhandle fh, struct stat *sb)
4795 {
4796 	struct mount *mp;
4797 	struct vnode *vp;
4798 	int error;
4799 
4800 	error = priv_check(td, PRIV_VFS_FHSTAT);
4801 	if (error != 0)
4802 		return (error);
4803 	if ((mp = vfs_busyfs(&fh.fh_fsid)) == NULL)
4804 		return (ESTALE);
4805 	error = VFS_FHTOVP(mp, &fh.fh_fid, LK_EXCLUSIVE, &vp);
4806 	vfs_unbusy(mp);
4807 	if (error != 0)
4808 		return (error);
4809 	error = VOP_STAT(vp, sb, td->td_ucred, NOCRED);
4810 	vput(vp);
4811 	return (error);
4812 }
4813 
4814 /*
4815  * Implement fstatfs() for (NFS) file handles.
4816  */
4817 #ifndef _SYS_SYSPROTO_H_
4818 struct fhstatfs_args {
4819 	struct fhandle *u_fhp;
4820 	struct statfs *buf;
4821 };
4822 #endif
4823 int
sys_fhstatfs(struct thread * td,struct fhstatfs_args * uap)4824 sys_fhstatfs(struct thread *td, struct fhstatfs_args *uap)
4825 {
4826 	struct statfs *sfp;
4827 	fhandle_t fh;
4828 	int error;
4829 
4830 	error = copyin(uap->u_fhp, &fh, sizeof(fhandle_t));
4831 	if (error != 0)
4832 		return (error);
4833 	sfp = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK);
4834 	error = kern_fhstatfs(td, fh, sfp);
4835 	if (error == 0)
4836 		error = copyout(sfp, uap->buf, sizeof(*sfp));
4837 	free(sfp, M_STATFS);
4838 	return (error);
4839 }
4840 
4841 int
kern_fhstatfs(struct thread * td,fhandle_t fh,struct statfs * buf)4842 kern_fhstatfs(struct thread *td, fhandle_t fh, struct statfs *buf)
4843 {
4844 	struct mount *mp;
4845 	struct vnode *vp;
4846 	int error;
4847 
4848 	error = priv_check(td, PRIV_VFS_FHSTATFS);
4849 	if (error != 0)
4850 		return (error);
4851 	if ((mp = vfs_busyfs(&fh.fh_fsid)) == NULL)
4852 		return (ESTALE);
4853 	error = VFS_FHTOVP(mp, &fh.fh_fid, LK_EXCLUSIVE, &vp);
4854 	if (error != 0) {
4855 		vfs_unbusy(mp);
4856 		return (error);
4857 	}
4858 	vput(vp);
4859 	error = prison_canseemount(td->td_ucred, mp);
4860 	if (error != 0)
4861 		goto out;
4862 #ifdef MAC
4863 	error = mac_mount_check_stat(td->td_ucred, mp);
4864 	if (error != 0)
4865 		goto out;
4866 #endif
4867 	error = VFS_STATFS(mp, buf);
4868 out:
4869 	vfs_unbusy(mp);
4870 	return (error);
4871 }
4872 
4873 /*
4874  * Unlike madvise(2), we do not make a best effort to remember every
4875  * possible caching hint.  Instead, we remember the last setting with
4876  * the exception that we will allow POSIX_FADV_NORMAL to adjust the
4877  * region of any current setting.
4878  */
4879 int
kern_posix_fadvise(struct thread * td,int fd,off_t offset,off_t len,int advice)4880 kern_posix_fadvise(struct thread *td, int fd, off_t offset, off_t len,
4881     int advice)
4882 {
4883 	struct fadvise_info *fa, *new;
4884 	struct file *fp;
4885 	struct vnode *vp;
4886 	off_t end;
4887 	int error;
4888 
4889 	if (offset < 0 || len < 0 || offset > OFF_MAX - len)
4890 		return (EINVAL);
4891 	AUDIT_ARG_VALUE(advice);
4892 	switch (advice) {
4893 	case POSIX_FADV_SEQUENTIAL:
4894 	case POSIX_FADV_RANDOM:
4895 	case POSIX_FADV_NOREUSE:
4896 		new = malloc(sizeof(*fa), M_FADVISE, M_WAITOK);
4897 		break;
4898 	case POSIX_FADV_NORMAL:
4899 	case POSIX_FADV_WILLNEED:
4900 	case POSIX_FADV_DONTNEED:
4901 		new = NULL;
4902 		break;
4903 	default:
4904 		return (EINVAL);
4905 	}
4906 	/* XXX: CAP_POSIX_FADVISE? */
4907 	AUDIT_ARG_FD(fd);
4908 	error = fget(td, fd, &cap_no_rights, &fp);
4909 	if (error != 0)
4910 		goto out;
4911 	AUDIT_ARG_FILE(td->td_proc, fp);
4912 	if ((fp->f_ops->fo_flags & DFLAG_SEEKABLE) == 0) {
4913 		error = ESPIPE;
4914 		goto out;
4915 	}
4916 	if (fp->f_type != DTYPE_VNODE) {
4917 		error = ENODEV;
4918 		goto out;
4919 	}
4920 	vp = fp->f_vnode;
4921 	if (vp->v_type != VREG) {
4922 		error = ENODEV;
4923 		goto out;
4924 	}
4925 	if (len == 0)
4926 		end = OFF_MAX;
4927 	else
4928 		end = offset + len - 1;
4929 	switch (advice) {
4930 	case POSIX_FADV_SEQUENTIAL:
4931 	case POSIX_FADV_RANDOM:
4932 	case POSIX_FADV_NOREUSE:
4933 		/*
4934 		 * Try to merge any existing non-standard region with
4935 		 * this new region if possible, otherwise create a new
4936 		 * non-standard region for this request.
4937 		 */
4938 		mtx_pool_lock(mtxpool_sleep, fp);
4939 		fa = fp->f_advice;
4940 		if (fa != NULL && fa->fa_advice == advice &&
4941 		    ((fa->fa_start <= end && fa->fa_end >= offset) ||
4942 		    (end != OFF_MAX && fa->fa_start == end + 1) ||
4943 		    (fa->fa_end != OFF_MAX && fa->fa_end + 1 == offset))) {
4944 			if (offset < fa->fa_start)
4945 				fa->fa_start = offset;
4946 			if (end > fa->fa_end)
4947 				fa->fa_end = end;
4948 		} else {
4949 			new->fa_advice = advice;
4950 			new->fa_start = offset;
4951 			new->fa_end = end;
4952 			fp->f_advice = new;
4953 			new = fa;
4954 		}
4955 		mtx_pool_unlock(mtxpool_sleep, fp);
4956 		break;
4957 	case POSIX_FADV_NORMAL:
4958 		/*
4959 		 * If a the "normal" region overlaps with an existing
4960 		 * non-standard region, trim or remove the
4961 		 * non-standard region.
4962 		 */
4963 		mtx_pool_lock(mtxpool_sleep, fp);
4964 		fa = fp->f_advice;
4965 		if (fa != NULL) {
4966 			if (offset <= fa->fa_start && end >= fa->fa_end) {
4967 				new = fa;
4968 				fp->f_advice = NULL;
4969 			} else if (offset <= fa->fa_start &&
4970 			    end >= fa->fa_start)
4971 				fa->fa_start = end + 1;
4972 			else if (offset <= fa->fa_end && end >= fa->fa_end)
4973 				fa->fa_end = offset - 1;
4974 			else if (offset >= fa->fa_start && end <= fa->fa_end) {
4975 				/*
4976 				 * If the "normal" region is a middle
4977 				 * portion of the existing
4978 				 * non-standard region, just remove
4979 				 * the whole thing rather than picking
4980 				 * one side or the other to
4981 				 * preserve.
4982 				 */
4983 				new = fa;
4984 				fp->f_advice = NULL;
4985 			}
4986 		}
4987 		mtx_pool_unlock(mtxpool_sleep, fp);
4988 		break;
4989 	case POSIX_FADV_WILLNEED:
4990 	case POSIX_FADV_DONTNEED:
4991 		error = VOP_ADVISE(vp, offset, end, advice);
4992 		break;
4993 	}
4994 out:
4995 	if (fp != NULL)
4996 		fdrop(fp, td);
4997 	free(new, M_FADVISE);
4998 	return (error);
4999 }
5000 
5001 int
sys_posix_fadvise(struct thread * td,struct posix_fadvise_args * uap)5002 sys_posix_fadvise(struct thread *td, struct posix_fadvise_args *uap)
5003 {
5004 	int error;
5005 
5006 	error = kern_posix_fadvise(td, uap->fd, uap->offset, uap->len,
5007 	    uap->advice);
5008 	return (kern_posix_error(td, error));
5009 }
5010 
5011 int
kern_copy_file_range(struct thread * td,int infd,off_t * inoffp,int outfd,off_t * outoffp,size_t len,unsigned int flags)5012 kern_copy_file_range(struct thread *td, int infd, off_t *inoffp, int outfd,
5013     off_t *outoffp, size_t len, unsigned int flags)
5014 {
5015 	struct file *infp, *infp1, *outfp, *outfp1;
5016 	struct vnode *invp, *outvp;
5017 	int error;
5018 	size_t retlen;
5019 	void *rl_rcookie, *rl_wcookie;
5020 	off_t inoff, outoff, savinoff, savoutoff;
5021 	bool foffsets_locked;
5022 
5023 	infp = outfp = NULL;
5024 	rl_rcookie = rl_wcookie = NULL;
5025 	foffsets_locked = false;
5026 	error = 0;
5027 	retlen = 0;
5028 
5029 	if (flags != 0) {
5030 		error = EINVAL;
5031 		goto out;
5032 	}
5033 	if (len > SSIZE_MAX)
5034 		/*
5035 		 * Although the len argument is size_t, the return argument
5036 		 * is ssize_t (which is signed).  Therefore a size that won't
5037 		 * fit in ssize_t can't be returned.
5038 		 */
5039 		len = SSIZE_MAX;
5040 
5041 	/* Get the file structures for the file descriptors. */
5042 	error = fget_read(td, infd,
5043 	    inoffp != NULL ? &cap_pread_rights : &cap_read_rights, &infp);
5044 	if (error != 0)
5045 		goto out;
5046 	if (infp->f_ops == &badfileops) {
5047 		error = EBADF;
5048 		goto out;
5049 	}
5050 	if (infp->f_vnode == NULL) {
5051 		error = EINVAL;
5052 		goto out;
5053 	}
5054 	error = fget_write(td, outfd,
5055 	    outoffp != NULL ? &cap_pwrite_rights : &cap_write_rights, &outfp);
5056 	if (error != 0)
5057 		goto out;
5058 	if (outfp->f_ops == &badfileops) {
5059 		error = EBADF;
5060 		goto out;
5061 	}
5062 	if (outfp->f_vnode == NULL) {
5063 		error = EINVAL;
5064 		goto out;
5065 	}
5066 
5067 	/*
5068 	 * Figure out which file offsets we're reading from and writing to.
5069 	 * If the offsets come from the file descriptions, we need to lock them,
5070 	 * and locking both offsets requires a loop to avoid deadlocks.
5071 	 */
5072 	infp1 = outfp1 = NULL;
5073 	if (inoffp != NULL)
5074 		inoff = *inoffp;
5075 	else
5076 		infp1 = infp;
5077 	if (outoffp != NULL)
5078 		outoff = *outoffp;
5079 	else
5080 		outfp1 = outfp;
5081 	if (infp1 != NULL || outfp1 != NULL) {
5082 		if (infp1 == outfp1) {
5083 			/*
5084 			 * Overlapping ranges are not allowed.  A more thorough
5085 			 * check appears below, but we must not lock the same
5086 			 * offset twice.
5087 			 */
5088 			error = EINVAL;
5089 			goto out;
5090 		}
5091 		foffset_lock_pair(infp1, &inoff, outfp1, &outoff, 0);
5092 		foffsets_locked = true;
5093 	}
5094 	savinoff = inoff;
5095 	savoutoff = outoff;
5096 
5097 	invp = infp->f_vnode;
5098 	outvp = outfp->f_vnode;
5099 	/* Sanity check the f_flag bits. */
5100 	if ((outfp->f_flag & (FWRITE | FAPPEND)) != FWRITE ||
5101 	    (infp->f_flag & FREAD) == 0) {
5102 		error = EBADF;
5103 		goto out;
5104 	}
5105 
5106 	/* If len == 0, just return 0. */
5107 	if (len == 0)
5108 		goto out;
5109 
5110 	/*
5111 	 * Make sure that the ranges we check and lock below are valid.  Note
5112 	 * that len is clamped to SSIZE_MAX above.
5113 	 */
5114 	if (inoff < 0 || outoff < 0) {
5115 		error = EINVAL;
5116 		goto out;
5117 	}
5118 
5119 	/*
5120 	 * If infp and outfp refer to the same file, the byte ranges cannot
5121 	 * overlap.
5122 	 */
5123 	if (invp == outvp) {
5124 		if ((inoff <= outoff && inoff + len > outoff) ||
5125 		    (inoff > outoff && outoff + len > inoff)) {
5126 			error = EINVAL;
5127 			goto out;
5128 		}
5129 		rangelock_may_recurse(&invp->v_rl);
5130 	}
5131 
5132 	/* Range lock the byte ranges for both invp and outvp. */
5133 	for (;;) {
5134 		rl_wcookie = vn_rangelock_wlock(outvp, outoff, outoff + len);
5135 		rl_rcookie = vn_rangelock_tryrlock(invp, inoff, inoff + len);
5136 		if (rl_rcookie != NULL)
5137 			break;
5138 		vn_rangelock_unlock(outvp, rl_wcookie);
5139 		rl_rcookie = vn_rangelock_rlock(invp, inoff, inoff + len);
5140 		vn_rangelock_unlock(invp, rl_rcookie);
5141 	}
5142 
5143 	retlen = len;
5144 	error = vn_copy_file_range(invp, &inoff, outvp, &outoff, &retlen,
5145 	    flags, infp->f_cred, outfp->f_cred, td);
5146 out:
5147 	if (rl_rcookie != NULL)
5148 		vn_rangelock_unlock(invp, rl_rcookie);
5149 	if (rl_wcookie != NULL)
5150 		vn_rangelock_unlock(outvp, rl_wcookie);
5151 	if (foffsets_locked) {
5152 		if (error == EINTR || error == ERESTART) {
5153 			inoff = savinoff;
5154 			outoff = savoutoff;
5155 		}
5156 		if (inoffp == NULL)
5157 			foffset_unlock(infp, inoff, 0);
5158 		else
5159 			*inoffp = inoff;
5160 		if (outoffp == NULL)
5161 			foffset_unlock(outfp, outoff, 0);
5162 		else
5163 			*outoffp = outoff;
5164 	}
5165 	if (outfp != NULL)
5166 		fdrop(outfp, td);
5167 	if (infp != NULL)
5168 		fdrop(infp, td);
5169 	td->td_retval[0] = retlen;
5170 	return (error);
5171 }
5172 
5173 int
sys_copy_file_range(struct thread * td,struct copy_file_range_args * uap)5174 sys_copy_file_range(struct thread *td, struct copy_file_range_args *uap)
5175 {
5176 	off_t inoff, outoff, *inoffp, *outoffp;
5177 	int error;
5178 
5179 	inoffp = outoffp = NULL;
5180 	if (uap->inoffp != NULL) {
5181 		error = copyin(uap->inoffp, &inoff, sizeof(off_t));
5182 		if (error != 0)
5183 			return (error);
5184 		inoffp = &inoff;
5185 	}
5186 	if (uap->outoffp != NULL) {
5187 		error = copyin(uap->outoffp, &outoff, sizeof(off_t));
5188 		if (error != 0)
5189 			return (error);
5190 		outoffp = &outoff;
5191 	}
5192 	error = kern_copy_file_range(td, uap->infd, inoffp, uap->outfd,
5193 	    outoffp, uap->len, uap->flags);
5194 	if (error == 0 && uap->inoffp != NULL)
5195 		error = copyout(inoffp, uap->inoffp, sizeof(off_t));
5196 	if (error == 0 && uap->outoffp != NULL)
5197 		error = copyout(outoffp, uap->outoffp, sizeof(off_t));
5198 	return (error);
5199 }
5200