xref: /freebsd/sys/kern/vfs_extattr.c (revision fdafd315ad0d0f28a11b9fb4476a9ab059c62b92)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 1999-2001 Robert N. M. Watson
5  * All rights reserved.
6  *
7  * This software was developed by Robert Watson for the TrustedBSD Project.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include <sys/param.h>
32 #include <sys/systm.h>
33 #include <sys/capsicum.h>
34 #include <sys/lock.h>
35 #include <sys/mount.h>
36 #include <sys/mutex.h>
37 #include <sys/sysproto.h>
38 #include <sys/fcntl.h>
39 #include <sys/namei.h>
40 #include <sys/filedesc.h>
41 #include <sys/limits.h>
42 #include <sys/vnode.h>
43 #include <sys/proc.h>
44 #include <sys/extattr.h>
45 #include <sys/syscallsubr.h>
46 
47 #include <security/audit/audit.h>
48 #include <security/mac/mac_framework.h>
49 
50 static int	user_extattr_set_path(struct thread *td, const char *path,
51 		    int attrnamespace, const char *attrname, void *data,
52 		    size_t nbytes, int follow);
53 static int	user_extattr_get_path(struct thread *td, const char *path,
54 		    int attrnamespace, const char *attrname, void *data,
55 		    size_t nbytes, int follow);
56 static int	user_extattr_delete_path(struct thread *td, const char *path,
57 		    int attrnamespace, const char *attrname, int follow);
58 static int	user_extattr_list_path(struct thread *td, const char *path,
59 		    int attrnamespace, void *data, size_t nbytes, int follow);
60 
61 /*
62  * Syscall to push extended attribute configuration information into the VFS.
63  * Accepts a path, which it converts to a mountpoint, as well as a command
64  * (int cmd), and attribute name and misc data.
65  *
66  * Currently this is used only by UFS1 extended attributes.
67  */
68 #ifndef _SYS_SYSPROTO_H_
69 struct extattrctl_args {
70 	const char *path;
71 	int cmd;
72 	const char *filename;
73 	int attrnamespace;
74 	const char *attrname;
75 };
76 #endif
77 int
sys_extattrctl(struct thread * td,struct extattrctl_args * uap)78 sys_extattrctl(struct thread *td, struct extattrctl_args *uap)
79 {
80 	struct vnode *filename_vp;
81 	struct nameidata nd;
82 	struct mount *mp, *mp_writable;
83 	char attrname[EXTATTR_MAXNAMELEN + 1];
84 	int error;
85 
86 	AUDIT_ARG_CMD(uap->cmd);
87 	AUDIT_ARG_VALUE(uap->attrnamespace);
88 	/*
89 	 * uap->attrname is not always defined.  We check again later when we
90 	 * invoke the VFS call so as to pass in NULL there if needed.
91 	 */
92 	if (uap->attrname != NULL) {
93 		error = copyinstr(uap->attrname, attrname, sizeof(attrname),
94 		    NULL);
95 		if (error)
96 			return (error);
97 	}
98 	AUDIT_ARG_TEXT(attrname);
99 
100 	mp = NULL;
101 	filename_vp = NULL;
102 	if (uap->filename != NULL) {
103 		NDINIT(&nd, LOOKUP, FOLLOW | AUDITVNODE2, UIO_USERSPACE,
104 		    uap->filename);
105 		error = namei(&nd);
106 		if (error)
107 			return (error);
108 		filename_vp = nd.ni_vp;
109 		NDFREE_PNBUF(&nd);
110 	}
111 
112 	/* uap->path is always defined. */
113 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | AUDITVNODE1, UIO_USERSPACE,
114 	    uap->path);
115 	error = namei(&nd);
116 	if (error)
117 		goto out;
118 	mp = nd.ni_vp->v_mount;
119 	error = vfs_busy(mp, 0);
120 	if (error) {
121 		vput(nd.ni_vp);
122 		NDFREE_PNBUF(&nd);
123 		mp = NULL;
124 		goto out;
125 	}
126 	VOP_UNLOCK(nd.ni_vp);
127 	error = vn_start_write(nd.ni_vp, &mp_writable, V_WAIT | V_PCATCH);
128 	vrele(nd.ni_vp);
129 	NDFREE_PNBUF(&nd);
130 	if (error)
131 		goto out;
132 	if (filename_vp != NULL) {
133 		/*
134 		 * uap->filename is not always defined.  If it is,
135 		 * grab a vnode lock, which VFS_EXTATTRCTL() will
136 		 * later release.
137 		 */
138 		error = vn_lock(filename_vp, LK_EXCLUSIVE);
139 		if (error) {
140 			vn_finished_write(mp_writable);
141 			goto out;
142 		}
143 	}
144 
145 	error = VFS_EXTATTRCTL(mp, uap->cmd, filename_vp, uap->attrnamespace,
146 	    uap->attrname != NULL ? attrname : NULL);
147 
148 	vn_finished_write(mp_writable);
149 out:
150 	if (mp != NULL)
151 		vfs_unbusy(mp);
152 
153 	/*
154 	 * VFS_EXTATTRCTL will have unlocked, but not de-ref'd, filename_vp,
155 	 * so vrele it if it is defined.
156 	 */
157 	if (filename_vp != NULL)
158 		vrele(filename_vp);
159 	return (error);
160 }
161 
162 /*-
163  * Set a named extended attribute on a file or directory
164  *
165  * Arguments: unlocked vnode "vp", attribute namespace "attrnamespace",
166  *            kernelspace string pointer "attrname", userspace buffer
167  *            pointer "data", buffer length "nbytes", thread "td".
168  * Returns: 0 on success, an error number otherwise
169  * Locks: none
170  * References: vp must be a valid reference for the duration of the call
171  */
172 static int
extattr_set_vp(struct vnode * vp,int attrnamespace,const char * attrname,void * data,size_t nbytes,struct thread * td)173 extattr_set_vp(struct vnode *vp, int attrnamespace, const char *attrname,
174     void *data, size_t nbytes, struct thread *td)
175 {
176 	struct mount *mp;
177 	struct uio auio;
178 	struct iovec aiov;
179 	ssize_t cnt;
180 	int error;
181 
182 	if (nbytes > IOSIZE_MAX)
183 		return (EINVAL);
184 
185 	error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH);
186 	if (error)
187 		return (error);
188 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
189 
190 	aiov.iov_base = data;
191 	aiov.iov_len = nbytes;
192 	auio.uio_iov = &aiov;
193 	auio.uio_iovcnt = 1;
194 	auio.uio_offset = 0;
195 	auio.uio_resid = nbytes;
196 	auio.uio_rw = UIO_WRITE;
197 	auio.uio_segflg = UIO_USERSPACE;
198 	auio.uio_td = td;
199 	cnt = nbytes;
200 
201 #ifdef MAC
202 	error = mac_vnode_check_setextattr(td->td_ucred, vp, attrnamespace,
203 	    attrname);
204 	if (error)
205 		goto done;
206 #endif
207 
208 	error = VOP_SETEXTATTR(vp, attrnamespace, attrname, &auio,
209 	    td->td_ucred, td);
210 	cnt -= auio.uio_resid;
211 	td->td_retval[0] = cnt;
212 
213 #ifdef MAC
214 done:
215 #endif
216 	VOP_UNLOCK(vp);
217 	vn_finished_write(mp);
218 	return (error);
219 }
220 
221 #ifndef _SYS_SYSPROTO_H_
222 struct extattr_set_fd_args {
223 	int fd;
224 	int attrnamespace;
225 	const char *attrname;
226 	void *data;
227 	size_t nbytes;
228 };
229 #endif
230 int
sys_extattr_set_fd(struct thread * td,struct extattr_set_fd_args * uap)231 sys_extattr_set_fd(struct thread *td, struct extattr_set_fd_args *uap)
232 {
233 	char attrname[EXTATTR_MAXNAMELEN + 1];
234 	int error;
235 
236 	error = copyinstr(uap->attrname, attrname, sizeof(attrname), NULL);
237 	if (error)
238 		return (error);
239 	return (kern_extattr_set_fd(td, uap->fd, uap->attrnamespace,
240 	    attrname, uap->data, uap->nbytes));
241 }
242 
243 int
kern_extattr_set_fd(struct thread * td,int fd,int attrnamespace,const char * attrname,void * data,size_t nbytes)244 kern_extattr_set_fd(struct thread *td, int fd, int attrnamespace,
245     const char *attrname, void *data, size_t nbytes)
246 {
247 	struct file *fp;
248 	cap_rights_t rights;
249 	int error;
250 
251 	AUDIT_ARG_FD(fd);
252 	AUDIT_ARG_VALUE(attrnamespace);
253 	AUDIT_ARG_TEXT(attrname);
254 
255 	error = getvnode_path(td, fd,
256 	    cap_rights_init_one(&rights, CAP_EXTATTR_SET), &fp);
257 	if (error)
258 		return (error);
259 
260 	error = extattr_set_vp(fp->f_vnode, attrnamespace,
261 	    attrname, data, nbytes, td);
262 	fdrop(fp, td);
263 
264 	return (error);
265 }
266 
267 #ifndef _SYS_SYSPROTO_H_
268 struct extattr_set_file_args {
269 	const char *path;
270 	int attrnamespace;
271 	const char *attrname;
272 	void *data;
273 	size_t nbytes;
274 };
275 #endif
276 int
sys_extattr_set_file(struct thread * td,struct extattr_set_file_args * uap)277 sys_extattr_set_file(struct thread *td, struct extattr_set_file_args *uap)
278 {
279 
280 	return (user_extattr_set_path(td, uap->path, uap->attrnamespace,
281 	    uap->attrname, uap->data, uap->nbytes, FOLLOW));
282 }
283 
284 #ifndef _SYS_SYSPROTO_H_
285 struct extattr_set_link_args {
286 	const char *path;
287 	int attrnamespace;
288 	const char *attrname;
289 	void *data;
290 	size_t nbytes;
291 };
292 #endif
293 int
sys_extattr_set_link(struct thread * td,struct extattr_set_link_args * uap)294 sys_extattr_set_link(struct thread *td, struct extattr_set_link_args *uap)
295 {
296 
297 	return (user_extattr_set_path(td, uap->path, uap->attrnamespace,
298 	    uap->attrname, uap->data, uap->nbytes, NOFOLLOW));
299 }
300 
301 static int
user_extattr_set_path(struct thread * td,const char * path,int attrnamespace,const char * uattrname,void * data,size_t nbytes,int follow)302 user_extattr_set_path(struct thread *td, const char *path, int attrnamespace,
303     const char *uattrname, void *data, size_t nbytes, int follow)
304 {
305 	char attrname[EXTATTR_MAXNAMELEN + 1];
306 	int error;
307 
308 	error = copyinstr(uattrname, attrname, sizeof(attrname), NULL);
309 	if (error)
310 		return (error);
311 	return (kern_extattr_set_path(td, path, attrnamespace,
312 	    attrname, data, nbytes, follow, UIO_USERSPACE));
313 }
314 
315 int
kern_extattr_set_path(struct thread * td,const char * path,int attrnamespace,const char * attrname,void * data,size_t nbytes,int follow,enum uio_seg pathseg)316 kern_extattr_set_path(struct thread *td, const char *path, int attrnamespace,
317     const char *attrname, void *data, size_t nbytes, int follow,
318     enum uio_seg pathseg)
319 {
320 	struct nameidata nd;
321 	int error;
322 
323 	AUDIT_ARG_VALUE(attrnamespace);
324 	AUDIT_ARG_TEXT(attrname);
325 
326 	NDINIT(&nd, LOOKUP, follow | AUDITVNODE1, pathseg, path);
327 	error = namei(&nd);
328 	if (error)
329 		return (error);
330 	NDFREE_PNBUF(&nd);
331 
332 	error = extattr_set_vp(nd.ni_vp, attrnamespace, attrname, data,
333 	    nbytes, td);
334 
335 	vrele(nd.ni_vp);
336 	return (error);
337 }
338 
339 /*-
340  * Get a named extended attribute on a file or directory
341  *
342  * Arguments: unlocked vnode "vp", attribute namespace "attrnamespace",
343  *            kernelspace string pointer "attrname", userspace buffer
344  *            pointer "data", buffer length "nbytes", thread "td".
345  * Returns: 0 on success, an error number otherwise
346  * Locks: none
347  * References: vp must be a valid reference for the duration of the call
348  */
349 static int
extattr_get_vp(struct vnode * vp,int attrnamespace,const char * attrname,void * data,size_t nbytes,struct thread * td)350 extattr_get_vp(struct vnode *vp, int attrnamespace, const char *attrname,
351     void *data, size_t nbytes, struct thread *td)
352 {
353 	struct uio auio, *auiop;
354 	struct iovec aiov;
355 	ssize_t cnt;
356 	size_t size, *sizep;
357 	int error;
358 
359 	if (nbytes > IOSIZE_MAX)
360 		return (EINVAL);
361 
362 	vn_lock(vp, LK_SHARED | LK_RETRY);
363 
364 	/*
365 	 * Slightly unusual semantics: if the user provides a NULL data
366 	 * pointer, they don't want to receive the data, just the maximum
367 	 * read length.
368 	 */
369 	auiop = NULL;
370 	sizep = NULL;
371 	cnt = 0;
372 	if (data != NULL) {
373 		aiov.iov_base = data;
374 		aiov.iov_len = nbytes;
375 		auio.uio_iov = &aiov;
376 		auio.uio_iovcnt = 1;
377 		auio.uio_offset = 0;
378 		auio.uio_resid = nbytes;
379 		auio.uio_rw = UIO_READ;
380 		auio.uio_segflg = UIO_USERSPACE;
381 		auio.uio_td = td;
382 		auiop = &auio;
383 		cnt = nbytes;
384 	} else
385 		sizep = &size;
386 
387 #ifdef MAC
388 	error = mac_vnode_check_getextattr(td->td_ucred, vp, attrnamespace,
389 	    attrname);
390 	if (error)
391 		goto done;
392 #endif
393 
394 	error = VOP_GETEXTATTR(vp, attrnamespace, attrname, auiop, sizep,
395 	    td->td_ucred, td);
396 
397 	if (auiop != NULL) {
398 		cnt -= auio.uio_resid;
399 		td->td_retval[0] = cnt;
400 	} else
401 		td->td_retval[0] = size;
402 #ifdef MAC
403 done:
404 #endif
405 	VOP_UNLOCK(vp);
406 	return (error);
407 }
408 
409 #ifndef _SYS_SYSPROTO_H_
410 struct extattr_get_fd_args {
411 	int fd;
412 	int attrnamespace;
413 	const char *attrname;
414 	void *data;
415 	size_t nbytes;
416 };
417 #endif
418 int
sys_extattr_get_fd(struct thread * td,struct extattr_get_fd_args * uap)419 sys_extattr_get_fd(struct thread *td, struct extattr_get_fd_args *uap)
420 {
421 	char attrname[EXTATTR_MAXNAMELEN + 1];
422 	int error;
423 
424 	error = copyinstr(uap->attrname, attrname, sizeof(attrname), NULL);
425 	if (error)
426 		return (error);
427 	return (kern_extattr_get_fd(td, uap->fd, uap->attrnamespace,
428 	    attrname, uap->data, uap->nbytes));
429 }
430 
431 int
kern_extattr_get_fd(struct thread * td,int fd,int attrnamespace,const char * attrname,void * data,size_t nbytes)432 kern_extattr_get_fd(struct thread *td, int fd, int attrnamespace,
433     const char *attrname, void *data, size_t nbytes)
434 {
435 	struct file *fp;
436 	cap_rights_t rights;
437 	int error;
438 
439 	AUDIT_ARG_FD(fd);
440 	AUDIT_ARG_VALUE(attrnamespace);
441 	AUDIT_ARG_TEXT(attrname);
442 
443 	error = getvnode_path(td, fd,
444 	    cap_rights_init_one(&rights, CAP_EXTATTR_GET), &fp);
445 	if (error)
446 		return (error);
447 
448 	error = extattr_get_vp(fp->f_vnode, attrnamespace,
449 	    attrname, data, nbytes, td);
450 
451 	fdrop(fp, td);
452 	return (error);
453 }
454 
455 #ifndef _SYS_SYSPROTO_H_
456 struct extattr_get_file_args {
457 	const char *path;
458 	int attrnamespace;
459 	const char *attrname;
460 	void *data;
461 	size_t nbytes;
462 };
463 #endif
464 int
sys_extattr_get_file(struct thread * td,struct extattr_get_file_args * uap)465 sys_extattr_get_file(struct thread *td, struct extattr_get_file_args *uap)
466 {
467 	return (user_extattr_get_path(td, uap->path, uap->attrnamespace,
468 	    uap->attrname, uap->data, uap->nbytes, FOLLOW));
469 }
470 
471 #ifndef _SYS_SYSPROTO_H_
472 struct extattr_get_link_args {
473 	const char *path;
474 	int attrnamespace;
475 	const char *attrname;
476 	void *data;
477 	size_t nbytes;
478 };
479 #endif
480 int
sys_extattr_get_link(struct thread * td,struct extattr_get_link_args * uap)481 sys_extattr_get_link(struct thread *td, struct extattr_get_link_args *uap)
482 {
483 	return (user_extattr_get_path(td, uap->path, uap->attrnamespace,
484 	    uap->attrname, uap->data, uap->nbytes, NOFOLLOW));
485 }
486 
487 static int
user_extattr_get_path(struct thread * td,const char * path,int attrnamespace,const char * uattrname,void * data,size_t nbytes,int follow)488 user_extattr_get_path(struct thread *td, const char *path, int attrnamespace,
489     const char *uattrname, void *data, size_t nbytes, int follow)
490 {
491 	char attrname[EXTATTR_MAXNAMELEN + 1];
492 	int error;
493 
494 	error = copyinstr(uattrname, attrname, sizeof(attrname), NULL);
495 	if (error)
496 		return (error);
497 	return (kern_extattr_get_path(td, path, attrnamespace,
498 	    attrname, data, nbytes, follow, UIO_USERSPACE));
499 }
500 
501 int
kern_extattr_get_path(struct thread * td,const char * path,int attrnamespace,const char * attrname,void * data,size_t nbytes,int follow,enum uio_seg pathseg)502 kern_extattr_get_path(struct thread *td, const char *path, int attrnamespace,
503     const char *attrname, void *data, size_t nbytes, int follow,
504     enum uio_seg pathseg)
505 {
506 	struct nameidata nd;
507 	int error;
508 
509 	AUDIT_ARG_VALUE(attrnamespace);
510 	AUDIT_ARG_TEXT(attrname);
511 
512 	NDINIT(&nd, LOOKUP, follow | AUDITVNODE1, pathseg, path);
513 	error = namei(&nd);
514 	if (error)
515 		return (error);
516 	NDFREE_PNBUF(&nd);
517 
518 	error = extattr_get_vp(nd.ni_vp, attrnamespace, attrname, data,
519 	    nbytes, td);
520 
521 	vrele(nd.ni_vp);
522 	return (error);
523 }
524 
525 /*
526  * extattr_delete_vp(): Delete a named extended attribute on a file or
527  *                      directory
528  *
529  * Arguments: unlocked vnode "vp", attribute namespace "attrnamespace",
530  *            kernelspace string pointer "attrname", proc "p"
531  * Returns: 0 on success, an error number otherwise
532  * Locks: none
533  * References: vp must be a valid reference for the duration of the call
534  */
535 static int
extattr_delete_vp(struct vnode * vp,int attrnamespace,const char * attrname,struct thread * td)536 extattr_delete_vp(struct vnode *vp, int attrnamespace, const char *attrname,
537     struct thread *td)
538 {
539 	struct mount *mp;
540 	int error;
541 
542 	error = vn_start_write(vp, &mp, V_WAIT | V_PCATCH);
543 	if (error)
544 		return (error);
545 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
546 
547 #ifdef MAC
548 	error = mac_vnode_check_deleteextattr(td->td_ucred, vp, attrnamespace,
549 	    attrname);
550 	if (error)
551 		goto done;
552 #endif
553 
554 	error = VOP_DELETEEXTATTR(vp, attrnamespace, attrname, td->td_ucred,
555 	    td);
556 	if (error == EOPNOTSUPP)
557 		error = VOP_SETEXTATTR(vp, attrnamespace, attrname, NULL,
558 		    td->td_ucred, td);
559 #ifdef MAC
560 done:
561 #endif
562 	VOP_UNLOCK(vp);
563 	vn_finished_write(mp);
564 	return (error);
565 }
566 
567 #ifndef _SYS_SYSPROTO_H_
568 struct extattr_delete_fd_args {
569 	int fd;
570 	int attrnamespace;
571 	const char *attrname;
572 };
573 #endif
574 int
sys_extattr_delete_fd(struct thread * td,struct extattr_delete_fd_args * uap)575 sys_extattr_delete_fd(struct thread *td, struct extattr_delete_fd_args *uap)
576 {
577 	char attrname[EXTATTR_MAXNAMELEN + 1];
578 	int error;
579 
580 	error = copyinstr(uap->attrname, attrname, sizeof(attrname), NULL);
581 	if (error)
582 		return (error);
583 	return (kern_extattr_delete_fd(td, uap->fd, uap->attrnamespace,
584 	    attrname));
585 }
586 
587 int
kern_extattr_delete_fd(struct thread * td,int fd,int attrnamespace,const char * attrname)588 kern_extattr_delete_fd(struct thread *td, int fd, int attrnamespace,
589     const char *attrname)
590 {
591 	struct file *fp;
592 	cap_rights_t rights;
593 	int error;
594 
595 	AUDIT_ARG_FD(fd);
596 	AUDIT_ARG_VALUE(attrnamespace);
597 	AUDIT_ARG_TEXT(attrname);
598 
599 	error = getvnode_path(td, fd,
600 	    cap_rights_init_one(&rights, CAP_EXTATTR_DELETE), &fp);
601 	if (error)
602 		return (error);
603 
604 	error = extattr_delete_vp(fp->f_vnode, attrnamespace,
605 	    attrname, td);
606 	fdrop(fp, td);
607 	return (error);
608 }
609 
610 #ifndef _SYS_SYSPROTO_H_
611 struct extattr_delete_file_args {
612 	const char *path;
613 	int attrnamespace;
614 	const char *attrname;
615 };
616 #endif
617 int
sys_extattr_delete_file(struct thread * td,struct extattr_delete_file_args * uap)618 sys_extattr_delete_file(struct thread *td, struct extattr_delete_file_args *uap)
619 {
620 
621 	return (user_extattr_delete_path(td, uap->path, uap->attrnamespace,
622 	    uap->attrname, FOLLOW));
623 }
624 
625 #ifndef _SYS_SYSPROTO_H_
626 struct extattr_delete_link_args {
627 	const char *path;
628 	int attrnamespace;
629 	const char *attrname;
630 };
631 #endif
632 int
sys_extattr_delete_link(struct thread * td,struct extattr_delete_link_args * uap)633 sys_extattr_delete_link(struct thread *td, struct extattr_delete_link_args *uap)
634 {
635 
636 	return (user_extattr_delete_path(td, uap->path, uap->attrnamespace,
637 	    uap->attrname, NOFOLLOW));
638 }
639 
640 int
user_extattr_delete_path(struct thread * td,const char * path,int attrnamespace,const char * uattrname,int follow)641 user_extattr_delete_path(struct thread *td, const char *path, int attrnamespace,
642     const char *uattrname, int follow)
643 {
644 	char attrname[EXTATTR_MAXNAMELEN + 1];
645 	int error;
646 
647 	error = copyinstr(uattrname, attrname, sizeof(attrname), NULL);
648 	if (error)
649 		return(error);
650 	return (kern_extattr_delete_path(td, path, attrnamespace,
651 	    attrname, follow, UIO_USERSPACE));
652 }
653 
654 int
kern_extattr_delete_path(struct thread * td,const char * path,int attrnamespace,const char * attrname,int follow,enum uio_seg pathseg)655 kern_extattr_delete_path(struct thread *td, const char *path, int attrnamespace,
656     const char *attrname, int follow, enum uio_seg pathseg)
657 {
658 	struct nameidata nd;
659 	int error;
660 
661 	AUDIT_ARG_VALUE(attrnamespace);
662 	AUDIT_ARG_TEXT(attrname);
663 
664 	NDINIT(&nd, LOOKUP, follow | AUDITVNODE1, pathseg, path);
665 	error = namei(&nd);
666 	if (error)
667 		return(error);
668 	NDFREE_PNBUF(&nd);
669 
670 	error = extattr_delete_vp(nd.ni_vp, attrnamespace, attrname, td);
671 	vrele(nd.ni_vp);
672 	return(error);
673 }
674 
675 /*-
676  * Retrieve a list of extended attributes on a file or directory.
677  *
678  * Arguments: unlocked vnode "vp", attribute namespace 'attrnamespace",
679  *            userspace buffer pointer "data", buffer length "nbytes",
680  *            thread "td".
681  * Returns: 0 on success, an error number otherwise
682  * Locks: none
683  * References: vp must be a valid reference for the duration of the call
684  */
685 static int
extattr_list_vp(struct vnode * vp,int attrnamespace,struct uio * auiop,struct thread * td)686 extattr_list_vp(struct vnode *vp, int attrnamespace, struct uio *auiop,
687     struct thread *td)
688 {
689 	size_t size, *sizep;
690 	ssize_t cnt;
691 	int error;
692 
693 	sizep = NULL;
694 	cnt = 0;
695 	if (auiop != NULL) {
696 		if (auiop->uio_resid > IOSIZE_MAX)
697 			return (EINVAL);
698 		cnt = auiop->uio_resid;
699 	} else
700 		sizep = &size;
701 
702 	vn_lock(vp, LK_SHARED | LK_RETRY);
703 
704 #ifdef MAC
705 	error = mac_vnode_check_listextattr(td->td_ucred, vp, attrnamespace);
706 	if (error) {
707 		VOP_UNLOCK(vp);
708 		return (error);
709 	}
710 #endif
711 
712 	error = VOP_LISTEXTATTR(vp, attrnamespace, auiop, sizep,
713 	    td->td_ucred, td);
714 	VOP_UNLOCK(vp);
715 
716 	if (auiop != NULL) {
717 		cnt -= auiop->uio_resid;
718 		td->td_retval[0] = cnt;
719 	} else
720 		td->td_retval[0] = size;
721 	return (error);
722 }
723 
724 #ifndef _SYS_SYSPROTO_H_
725 struct extattr_list_fd_args {
726 	int fd;
727 	int attrnamespace;
728 	void *data;
729 	size_t nbytes;
730 };
731 #endif
732 int
sys_extattr_list_fd(struct thread * td,struct extattr_list_fd_args * uap)733 sys_extattr_list_fd(struct thread *td, struct extattr_list_fd_args *uap)
734 {
735 	struct uio auio, *auiop;
736 	struct iovec aiov;
737 
738 	if (uap->data != NULL) {
739 		aiov.iov_base = uap->data;
740 		aiov.iov_len = uap->nbytes;
741 		auio.uio_iov = &aiov;
742 		auio.uio_iovcnt = 1;
743 		auio.uio_offset = 0;
744 		auio.uio_resid = uap->nbytes;
745 		auio.uio_rw = UIO_READ;
746 		auio.uio_segflg = UIO_USERSPACE;
747 		auio.uio_td = td;
748 		auiop = &auio;
749 	} else
750 		auiop = NULL;
751 
752 	return (kern_extattr_list_fd(td, uap->fd, uap->attrnamespace,
753 	    auiop));
754 }
755 
756 int
kern_extattr_list_fd(struct thread * td,int fd,int attrnamespace,struct uio * auiop)757 kern_extattr_list_fd(struct thread *td, int fd, int attrnamespace,
758     struct uio *auiop)
759 {
760 	struct file *fp;
761 	cap_rights_t rights;
762 	int error;
763 
764 	AUDIT_ARG_FD(fd);
765 	AUDIT_ARG_VALUE(attrnamespace);
766 	error = getvnode_path(td, fd,
767 	    cap_rights_init_one(&rights, CAP_EXTATTR_LIST), &fp);
768 	if (error)
769 		return (error);
770 
771 	error = extattr_list_vp(fp->f_vnode, attrnamespace, auiop, td);
772 
773 	fdrop(fp, td);
774 	return (error);
775 }
776 
777 #ifndef _SYS_SYSPROTO_H_
778 struct extattr_list_file_args {
779 	const char *path;
780 	int attrnamespace;
781 	void *data;
782 	size_t nbytes;
783 }
784 #endif
785 int
sys_extattr_list_file(struct thread * td,struct extattr_list_file_args * uap)786 sys_extattr_list_file(struct thread *td, struct extattr_list_file_args *uap)
787 {
788 
789 	return (user_extattr_list_path(td, uap->path, uap->attrnamespace,
790 	    uap->data, uap->nbytes, FOLLOW));
791 }
792 
793 #ifndef _SYS_SYSPROTO_H_
794 struct extattr_list_link_args {
795 	const char *path;
796 	int attrnamespace;
797 	void *data;
798 	size_t nbytes;
799 };
800 #endif
801 int
sys_extattr_list_link(struct thread * td,struct extattr_list_link_args * uap)802 sys_extattr_list_link(struct thread *td, struct extattr_list_link_args *uap)
803 {
804 
805 	return (user_extattr_list_path(td, uap->path, uap->attrnamespace,
806 	    uap->data, uap->nbytes, NOFOLLOW));
807 }
808 
809 static int
user_extattr_list_path(struct thread * td,const char * path,int attrnamespace,void * data,size_t nbytes,int follow)810 user_extattr_list_path(struct thread *td, const char *path, int attrnamespace,
811     void *data, size_t nbytes, int follow)
812 {
813 	struct uio auio, *auiop;
814 	struct iovec aiov;
815 
816 	if (data != NULL) {
817 		aiov.iov_base = data;
818 		aiov.iov_len = nbytes;
819 		auio.uio_iov = &aiov;
820 		auio.uio_iovcnt = 1;
821 		auio.uio_offset = 0;
822 		auio.uio_resid = nbytes;
823 		auio.uio_rw = UIO_READ;
824 		auio.uio_segflg = UIO_USERSPACE;
825 		auio.uio_td = td;
826 		auiop = &auio;
827 	} else
828 		auiop = NULL;
829 
830 	return (kern_extattr_list_path(td, path, attrnamespace,
831 	    auiop, follow, UIO_USERSPACE));
832 }
833 
834 int
kern_extattr_list_path(struct thread * td,const char * path,int attrnamespace,struct uio * auiop,int follow,enum uio_seg pathseg)835 kern_extattr_list_path(struct thread *td, const char *path, int attrnamespace,
836     struct uio *auiop, int follow, enum uio_seg pathseg)
837 {
838 	struct nameidata nd;
839 	int error;
840 
841 	AUDIT_ARG_VALUE(attrnamespace);
842 	NDINIT(&nd, LOOKUP, follow | AUDITVNODE1, pathseg, path);
843 	error = namei(&nd);
844 	if (error)
845 		return (error);
846 	NDFREE_PNBUF(&nd);
847 
848 	error = extattr_list_vp(nd.ni_vp, attrnamespace, auiop, td);
849 
850 	vrele(nd.ni_vp);
851 	return (error);
852 }
853