1 /* $NetBSD: ulfs_extattr.c,v 1.7 2014/02/07 15:29:23 hannken Exp $ */
2 /* from NetBSD: ufs_extattr.c,v 1.41 2012/12/08 13:42:36 manu Exp */
3
4 /*-
5 * Copyright (c) 1999-2002 Robert N. M. Watson
6 * Copyright (c) 2002-2003 Networks Associates Technology, Inc.
7 * All rights reserved.
8 *
9 * This software was developed by Robert Watson for the TrustedBSD Project.
10 *
11 * This software was developed for the FreeBSD Project in part by Network
12 * Associates Laboratories, the Security Research Division of Network
13 * Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"),
14 * as part of the DARPA CHATS research program.
15 *
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions
18 * are met:
19 * 1. Redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer.
21 * 2. Redistributions in binary form must reproduce the above copyright
22 * notice, this list of conditions and the following disclaimer in the
23 * documentation and/or other materials provided with the distribution.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 *
37 */
38
39 /*
40 * Support for file system extended attributes on the ULFS1 file system.
41 *
42 * Extended attributes are defined in the form name=value, where name is
43 * a nul-terminated string in the style of a file name, and value is a
44 * binary blob of zero or more bytes. The ULFS1 extended attribute service
45 * layers support for extended attributes onto a backing file, in the style
46 * of the quota implementation, meaning that it requires no underlying format
47 * changes to the file system. This design choice exchanges simplicity,
48 * usability, and easy deployment for performance.
49 */
50
51 #include <sys/cdefs.h>
52 __KERNEL_RCSID(0, "$NetBSD: ulfs_extattr.c,v 1.7 2014/02/07 15:29:23 hannken Exp $");
53
54 #ifdef _KERNEL_OPT
55 #include "opt_lfs.h"
56 #endif
57
58 #include <sys/param.h>
59 #include <sys/systm.h>
60 #include <sys/reboot.h>
61 #include <sys/kauth.h>
62 #include <sys/kernel.h>
63 #include <sys/namei.h>
64 #include <sys/kmem.h>
65 #include <sys/fcntl.h>
66 #include <sys/lwp.h>
67 #include <sys/vnode.h>
68 #include <sys/mount.h>
69 #include <sys/lock.h>
70 #include <sys/dirent.h>
71 #include <sys/extattr.h>
72 #include <sys/sysctl.h>
73
74 #include <ufs/lfs/ulfs_extattr.h>
75 #include <ufs/lfs/ulfsmount.h>
76 #include <ufs/lfs/ulfs_inode.h>
77 #include <ufs/lfs/ulfs_bswap.h>
78 #include <ufs/lfs/ulfs_extern.h>
79
80 int ulfs_extattr_sync = 1;
81 int ulfs_extattr_autocreate = 1024;
82
83 static int ulfs_extattr_valid_attrname(int attrnamespace,
84 const char *attrname);
85 static int ulfs_extattr_enable_with_open(struct ulfsmount *ump,
86 struct vnode *vp, int attrnamespace, const char *attrname,
87 struct lwp *l);
88 static int ulfs_extattr_enable(struct ulfsmount *ump, int attrnamespace,
89 const char *attrname, struct vnode *backing_vnode,
90 struct lwp *l);
91 static int ulfs_extattr_disable(struct ulfsmount *ump, int attrnamespace,
92 const char *attrname, struct lwp *l);
93 static int ulfs_extattr_get(struct vnode *vp, int attrnamespace,
94 const char *name, struct uio *uio, size_t *size,
95 kauth_cred_t cred, struct lwp *l);
96 static int ulfs_extattr_list(struct vnode *vp, int attrnamespace,
97 struct uio *uio, size_t *size, int flag,
98 kauth_cred_t cred, struct lwp *l);
99 static int ulfs_extattr_set(struct vnode *vp, int attrnamespace,
100 const char *name, struct uio *uio, kauth_cred_t cred,
101 struct lwp *l);
102 static int ulfs_extattr_rm(struct vnode *vp, int attrnamespace,
103 const char *name, kauth_cred_t cred, struct lwp *l);
104 static struct ulfs_extattr_list_entry *ulfs_extattr_find_attr(struct ulfsmount *,
105 int, const char *);
106 static int ulfs_extattr_get_header(struct vnode *,
107 struct ulfs_extattr_list_entry *,
108 struct ulfs_extattr_header *, off_t *);
109
110 /*
111 * Convert a FreeBSD extended attribute and namespace to a consistent string
112 * representation.
113 *
114 * The returned value, if not NULL, is guaranteed to be an allocated object
115 * of its size as returned by strlen() + 1 and must be freed by the caller.
116 */
117 static char *
from_freebsd_extattr(int attrnamespace,const char * attrname)118 from_freebsd_extattr(int attrnamespace, const char *attrname)
119 {
120 const char *namespace;
121 char *attr;
122 size_t len;
123
124 if (attrnamespace == EXTATTR_NAMESPACE_SYSTEM)
125 namespace = "system";
126 else if (attrnamespace == EXTATTR_NAMESPACE_USER)
127 namespace = "user";
128 else
129 return NULL;
130
131 /* <namespace>.<attrname>\0 */
132 len = strlen(namespace) + 1 + strlen(attrname) + 1;
133
134 attr = kmem_alloc(len, KM_SLEEP);
135
136 snprintf(attr, len, "%s.%s", namespace, attrname);
137
138 return attr;
139 }
140
141 /*
142 * Internal wrapper around a conversion-check-free sequence.
143 */
144 static int
internal_extattr_check_cred(vnode_t * vp,int attrnamespace,const char * name,kauth_cred_t cred,int access_mode)145 internal_extattr_check_cred(vnode_t *vp, int attrnamespace, const char *name,
146 kauth_cred_t cred, int access_mode)
147 {
148 char *attr;
149 int error;
150
151 attr = from_freebsd_extattr(attrnamespace, name);
152 if (attr == NULL)
153 return EINVAL;
154
155 error = extattr_check_cred(vp, attr, cred, access_mode);
156
157 kmem_free(attr, strlen(attr) + 1);
158
159 return error;
160 }
161
162 /*
163 * Per-FS attribute lock protecting attribute operations.
164 * XXX Right now there is a lot of lock contention due to having a single
165 * lock per-FS; really, this should be far more fine-grained.
166 */
167 static void
ulfs_extattr_uepm_lock(struct ulfsmount * ump)168 ulfs_extattr_uepm_lock(struct ulfsmount *ump)
169 {
170
171 /* XXX Why does this need to be recursive? */
172 if (mutex_owned(&ump->um_extattr.uepm_lock)) {
173 ump->um_extattr.uepm_lockcnt++;
174 return;
175 }
176 mutex_enter(&ump->um_extattr.uepm_lock);
177 }
178
179 static void
ulfs_extattr_uepm_unlock(struct ulfsmount * ump)180 ulfs_extattr_uepm_unlock(struct ulfsmount *ump)
181 {
182
183 if (ump->um_extattr.uepm_lockcnt != 0) {
184 KASSERT(mutex_owned(&ump->um_extattr.uepm_lock));
185 ump->um_extattr.uepm_lockcnt--;
186 return;
187 }
188 mutex_exit(&ump->um_extattr.uepm_lock);
189 }
190
191 /*-
192 * Determine whether the name passed is a valid name for an actual
193 * attribute.
194 *
195 * Invalid currently consists of:
196 * NULL pointer for attrname
197 * zero-length attrname (used to retrieve application attribute list)
198 */
199 static int
ulfs_extattr_valid_attrname(int attrnamespace,const char * attrname)200 ulfs_extattr_valid_attrname(int attrnamespace, const char *attrname)
201 {
202
203 if (attrname == NULL)
204 return (0);
205 if (strlen(attrname) == 0)
206 return (0);
207 return (1);
208 }
209
210 /*
211 * Autocreate an attribute storage
212 */
213 static struct ulfs_extattr_list_entry *
ulfs_extattr_autocreate_attr(struct vnode * vp,int attrnamespace,const char * attrname,struct lwp * l)214 ulfs_extattr_autocreate_attr(struct vnode *vp, int attrnamespace,
215 const char *attrname, struct lwp *l)
216 {
217 struct mount *mp = vp->v_mount;
218 struct ulfsmount *ump = VFSTOULFS(mp);
219 struct vnode *backing_vp;
220 struct nameidata nd;
221 struct pathbuf *pb;
222 char *path;
223 struct ulfs_extattr_fileheader uef;
224 struct ulfs_extattr_list_entry *uele;
225 int error;
226
227 path = PNBUF_GET();
228
229 /*
230 * We only support system and user namespace autocreation
231 */
232 switch (attrnamespace) {
233 case EXTATTR_NAMESPACE_SYSTEM:
234 (void)snprintf(path, PATH_MAX, "%s/%s/%s/%s",
235 mp->mnt_stat.f_mntonname,
236 ULFS_EXTATTR_FSROOTSUBDIR,
237 ULFS_EXTATTR_SUBDIR_SYSTEM,
238 attrname);
239 break;
240 case EXTATTR_NAMESPACE_USER:
241 (void)snprintf(path, PATH_MAX, "%s/%s/%s/%s",
242 mp->mnt_stat.f_mntonname,
243 ULFS_EXTATTR_FSROOTSUBDIR,
244 ULFS_EXTATTR_SUBDIR_USER,
245 attrname);
246 break;
247 default:
248 PNBUF_PUT(path);
249 return NULL;
250 break;
251 }
252
253 /*
254 * XXX unlock/lock should only be done when setting extattr
255 * on backing store or one of its parent directory
256 * including root, but we always do it for now.
257 */
258 KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE);
259 VOP_UNLOCK(vp);
260
261 pb = pathbuf_create(path);
262 NDINIT(&nd, CREATE, LOCKPARENT, pb);
263
264 error = vn_open(&nd, O_CREAT|O_RDWR, 0600);
265
266 /*
267 * Reacquire the lock on the vnode
268 */
269 KASSERT(VOP_ISLOCKED(vp) == 0);
270 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
271
272 if (error != 0) {
273 pathbuf_destroy(pb);
274 PNBUF_PUT(path);
275 return NULL;
276 }
277
278 KASSERT(nd.ni_vp != NULL);
279 KASSERT(VOP_ISLOCKED(nd.ni_vp) == LK_EXCLUSIVE);
280 KASSERT(VOP_ISLOCKED(nd.ni_dvp) == 0);
281
282 /*
283 * backing_vp is the backing store.
284 */
285 backing_vp = nd.ni_vp;
286 pathbuf_destroy(pb);
287 PNBUF_PUT(path);
288
289 uef.uef_magic = ULFS_EXTATTR_MAGIC;
290 uef.uef_version = ULFS_EXTATTR_VERSION;
291 uef.uef_size = ulfs_extattr_autocreate;
292
293 error = vn_rdwr(UIO_WRITE, backing_vp, &uef, sizeof(uef), 0,
294 UIO_SYSSPACE, IO_NODELOCKED|IO_APPEND,
295 l->l_cred, NULL, l);
296
297 VOP_UNLOCK(backing_vp);
298
299 if (error != 0) {
300 printf("%s: write uef header failed for %s, error = %d\n",
301 __func__, attrname, error);
302 vn_close(backing_vp, FREAD|FWRITE, l->l_cred);
303 return NULL;
304 }
305
306 /*
307 * Now enable attribute.
308 */
309 error = ulfs_extattr_enable(ump,attrnamespace, attrname, backing_vp, l);
310 KASSERT(VOP_ISLOCKED(backing_vp) == 0);
311
312 if (error != 0) {
313 printf("%s: enable %s failed, error %d\n",
314 __func__, attrname, error);
315 vn_close(backing_vp, FREAD|FWRITE, l->l_cred);
316 return NULL;
317 }
318
319 uele = ulfs_extattr_find_attr(ump, attrnamespace, attrname);
320 if (uele == NULL) {
321 printf("%s: atttribute %s created but not found!\n",
322 __func__, attrname);
323 vn_close(backing_vp, FREAD|FWRITE, l->l_cred);
324 return NULL;
325 }
326
327 printf("%s: EA backing store autocreated for %s\n",
328 mp->mnt_stat.f_mntonname, attrname);
329
330 return uele;
331 }
332
333 /*
334 * Locate an attribute given a name and mountpoint.
335 * Must be holding uepm lock for the mount point.
336 */
337 static struct ulfs_extattr_list_entry *
ulfs_extattr_find_attr(struct ulfsmount * ump,int attrnamespace,const char * attrname)338 ulfs_extattr_find_attr(struct ulfsmount *ump, int attrnamespace,
339 const char *attrname)
340 {
341 struct ulfs_extattr_list_entry *search_attribute;
342
343 for (search_attribute = LIST_FIRST(&ump->um_extattr.uepm_list);
344 search_attribute != NULL;
345 search_attribute = LIST_NEXT(search_attribute, uele_entries)) {
346 if (!(strncmp(attrname, search_attribute->uele_attrname,
347 ULFS_EXTATTR_MAXEXTATTRNAME)) &&
348 (attrnamespace == search_attribute->uele_attrnamespace)) {
349 return (search_attribute);
350 }
351 }
352
353 return (0);
354 }
355
356 /*
357 * Initialize per-FS structures supporting extended attributes. Do not
358 * start extended attributes yet.
359 */
360 void
ulfs_extattr_uepm_init(struct ulfs_extattr_per_mount * uepm)361 ulfs_extattr_uepm_init(struct ulfs_extattr_per_mount *uepm)
362 {
363
364 uepm->uepm_flags = 0;
365 uepm->uepm_lockcnt = 0;
366
367 LIST_INIT(&uepm->uepm_list);
368 mutex_init(&uepm->uepm_lock, MUTEX_DEFAULT, IPL_NONE);
369 uepm->uepm_flags |= ULFS_EXTATTR_UEPM_INITIALIZED;
370 }
371
372 /*
373 * Destroy per-FS structures supporting extended attributes. Assumes
374 * that EAs have already been stopped, and will panic if not.
375 */
376 void
ulfs_extattr_uepm_destroy(struct ulfs_extattr_per_mount * uepm)377 ulfs_extattr_uepm_destroy(struct ulfs_extattr_per_mount *uepm)
378 {
379
380 if (!(uepm->uepm_flags & ULFS_EXTATTR_UEPM_INITIALIZED))
381 panic("ulfs_extattr_uepm_destroy: not initialized");
382
383 if ((uepm->uepm_flags & ULFS_EXTATTR_UEPM_STARTED))
384 panic("ulfs_extattr_uepm_destroy: called while still started");
385
386 /*
387 * It's not clear that either order for the next two lines is
388 * ideal, and it should never be a problem if this is only called
389 * during unmount, and with vfs_busy().
390 */
391 uepm->uepm_flags &= ~ULFS_EXTATTR_UEPM_INITIALIZED;
392 mutex_destroy(&uepm->uepm_lock);
393 }
394
395 /*
396 * Start extended attribute support on an FS.
397 */
398 int
ulfs_extattr_start(struct mount * mp,struct lwp * l)399 ulfs_extattr_start(struct mount *mp, struct lwp *l)
400 {
401 struct ulfsmount *ump;
402 int error = 0;
403
404 ump = VFSTOULFS(mp);
405
406 ulfs_extattr_uepm_lock(ump);
407
408 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_INITIALIZED)) {
409 error = EOPNOTSUPP;
410 goto unlock;
411 }
412 if (ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_STARTED) {
413 error = EBUSY;
414 goto unlock;
415 }
416
417 ump->um_extattr.uepm_flags |= ULFS_EXTATTR_UEPM_STARTED;
418
419 ump->um_extattr.uepm_ucred = l->l_cred;
420 kauth_cred_hold(ump->um_extattr.uepm_ucred);
421
422 unlock:
423 ulfs_extattr_uepm_unlock(ump);
424
425 return (error);
426 }
427
428 /*
429 * Helper routine: given a locked parent directory and filename, return
430 * the locked vnode of the inode associated with the name. Will not
431 * follow symlinks, may return any type of vnode. Lock on parent will
432 * be released even in the event of a failure. In the event that the
433 * target is the parent (i.e., "."), there will be two references and
434 * one lock, requiring the caller to possibly special-case.
435 */
436 static int
ulfs_extattr_lookup(struct vnode * start_dvp,int lockparent,const char * dirname,struct vnode ** vp,struct lwp * l)437 ulfs_extattr_lookup(struct vnode *start_dvp, int lockparent, const char *dirname,
438 struct vnode **vp, struct lwp *l)
439 {
440 struct vop_lookup_v2_args vargs;
441 struct componentname cnp;
442 struct vnode *target_vp;
443 char *pnbuf;
444 int error;
445
446 KASSERT(VOP_ISLOCKED(start_dvp) == LK_EXCLUSIVE);
447
448 pnbuf = PNBUF_GET();
449
450 memset(&cnp, 0, sizeof(cnp));
451 cnp.cn_nameiop = LOOKUP;
452 cnp.cn_flags = ISLASTCN | lockparent;
453 cnp.cn_cred = l->l_cred;
454 cnp.cn_nameptr = pnbuf;
455 error = copystr(dirname, pnbuf, MAXPATHLEN, &cnp.cn_namelen);
456 if (error) {
457 if (lockparent == 0) {
458 VOP_UNLOCK(start_dvp);
459 }
460 PNBUF_PUT(pnbuf);
461 printf("ulfs_extattr_lookup: copystr failed\n");
462 return (error);
463 }
464 cnp.cn_namelen--; /* trim nul termination */
465 vargs.a_desc = NULL;
466 vargs.a_dvp = start_dvp;
467 vargs.a_vpp = &target_vp;
468 vargs.a_cnp = &cnp;
469 error = ulfs_lookup(&vargs);
470 PNBUF_PUT(pnbuf);
471 if (error) {
472 if (lockparent == 0) {
473 VOP_UNLOCK(start_dvp);
474 }
475 return (error);
476 }
477 #if 0
478 if (target_vp == start_dvp)
479 panic("ulfs_extattr_lookup: target_vp == start_dvp");
480 #endif
481
482 if (target_vp != start_dvp) {
483 error = vn_lock(target_vp, LK_EXCLUSIVE);
484 if (lockparent == 0)
485 VOP_UNLOCK(start_dvp);
486 if (error) {
487 vrele(target_vp);
488 return error;
489 }
490 }
491
492 KASSERT(VOP_ISLOCKED(target_vp) == LK_EXCLUSIVE);
493 *vp = target_vp;
494 return (0);
495 }
496
497 /*
498 * Enable an EA using the passed filesystem, backing vnode, attribute name,
499 * namespace, and proc. Will perform a VOP_OPEN() on the vp, so expects vp
500 * to be locked when passed in. The vnode will be returned unlocked,
501 * regardless of success/failure of the function. As a result, the caller
502 * will always need to vrele(), but not vput().
503 */
504 static int
ulfs_extattr_enable_with_open(struct ulfsmount * ump,struct vnode * vp,int attrnamespace,const char * attrname,struct lwp * l)505 ulfs_extattr_enable_with_open(struct ulfsmount *ump, struct vnode *vp,
506 int attrnamespace, const char *attrname, struct lwp *l)
507 {
508 int error;
509
510 error = VOP_OPEN(vp, FREAD|FWRITE, l->l_cred);
511 if (error) {
512 printf("ulfs_extattr_enable_with_open.VOP_OPEN(): failed "
513 "with %d\n", error);
514 VOP_UNLOCK(vp);
515 return (error);
516 }
517
518 mutex_enter(vp->v_interlock);
519 vp->v_writecount++;
520 mutex_exit(vp->v_interlock);
521
522 vref(vp);
523
524 VOP_UNLOCK(vp);
525
526 error = ulfs_extattr_enable(ump, attrnamespace, attrname, vp, l);
527 if (error != 0)
528 vn_close(vp, FREAD|FWRITE, l->l_cred);
529 return (error);
530 }
531
532 /*
533 * Given a locked directory vnode, iterate over the names in the directory
534 * and use ulfs_extattr_lookup() to retrieve locked vnodes of potential
535 * attribute files. Then invoke ulfs_extattr_enable_with_open() on each
536 * to attempt to start the attribute. Leaves the directory locked on
537 * exit.
538 */
539 static int
ulfs_extattr_iterate_directory(struct ulfsmount * ump,struct vnode * dvp,int attrnamespace,struct lwp * l)540 ulfs_extattr_iterate_directory(struct ulfsmount *ump, struct vnode *dvp,
541 int attrnamespace, struct lwp *l)
542 {
543 struct vop_readdir_args vargs;
544 struct statvfs *sbp = &ump->um_mountp->mnt_stat;
545 struct dirent *dp, *edp;
546 struct vnode *attr_vp;
547 struct uio auio;
548 struct iovec aiov;
549 char *dirbuf;
550 int error, eofflag = 0;
551
552 if (dvp->v_type != VDIR)
553 return (ENOTDIR);
554
555 dirbuf = kmem_alloc(LFS_DIRBLKSIZ, KM_SLEEP);
556
557 auio.uio_iov = &aiov;
558 auio.uio_iovcnt = 1;
559 auio.uio_rw = UIO_READ;
560 auio.uio_offset = 0;
561 UIO_SETUP_SYSSPACE(&auio);
562
563 vargs.a_desc = NULL;
564 vargs.a_vp = dvp;
565 vargs.a_uio = &auio;
566 vargs.a_cred = l->l_cred;
567 vargs.a_eofflag = &eofflag;
568 vargs.a_ncookies = NULL;
569 vargs.a_cookies = NULL;
570
571 while (!eofflag) {
572 auio.uio_resid = LFS_DIRBLKSIZ;
573 aiov.iov_base = dirbuf;
574 aiov.iov_len = LFS_DIRBLKSIZ;
575 error = ulfs_readdir(&vargs);
576 if (error) {
577 printf("ulfs_extattr_iterate_directory: ulfs_readdir "
578 "%d\n", error);
579 return (error);
580 }
581
582 /*
583 * XXXRW: While in LFS, we always get LFS_DIRBLKSIZ returns from
584 * the directory code on success, on other file systems this
585 * may not be the case. For portability, we should check the
586 * read length on return from ulfs_readdir().
587 */
588 edp = (struct dirent *)&dirbuf[LFS_DIRBLKSIZ];
589 for (dp = (struct dirent *)dirbuf; dp < edp; ) {
590 if (dp->d_reclen == 0)
591 break;
592 /* Skip "." and ".." */
593 if (dp->d_name[0] == '.' &&
594 (dp->d_name[1] == '\0' ||
595 (dp->d_name[1] == '.' && dp->d_name[2] == '\0')))
596 goto next;
597 error = ulfs_extattr_lookup(dvp, LOCKPARENT,
598 dp->d_name, &attr_vp, l);
599 if (error == ENOENT) {
600 goto next; /* keep silent */
601 } else if (error) {
602 printf("ulfs_extattr_iterate_directory: lookup "
603 "%s %d\n", dp->d_name, error);
604 } else if (attr_vp == dvp) {
605 vrele(attr_vp);
606 } else if (attr_vp->v_type != VREG) {
607 vput(attr_vp);
608 } else {
609 error = ulfs_extattr_enable_with_open(ump,
610 attr_vp, attrnamespace, dp->d_name, l);
611 vrele(attr_vp);
612 if (error) {
613 printf("ulfs_extattr_iterate_directory: "
614 "enable %s %d\n", dp->d_name,
615 error);
616 } else if (bootverbose) {
617 printf("%s: EA %s loaded\n",
618 sbp->f_mntonname, dp->d_name);
619 }
620 }
621 next:
622 dp = (struct dirent *) ((char *)dp + dp->d_reclen);
623 if (dp >= edp)
624 break;
625 }
626 }
627 kmem_free(dirbuf, LFS_DIRBLKSIZ);
628
629 return (0);
630 }
631
632 /*
633 * Auto-start of extended attributes, to be executed (optionally) at
634 * mount-time.
635 */
636 int
ulfs_extattr_autostart(struct mount * mp,struct lwp * l)637 ulfs_extattr_autostart(struct mount *mp, struct lwp *l)
638 {
639 struct vnode *rvp, *attr_dvp, *attr_system_dvp, *attr_user_dvp;
640 int error;
641
642 /*
643 * Does ULFS_EXTATTR_FSROOTSUBDIR exist off the filesystem root?
644 * If so, automatically start EA's.
645 */
646 error = VFS_ROOT(mp, &rvp);
647 if (error) {
648 printf("ulfs_extattr_autostart.VFS_ROOT() returned %d\n",
649 error);
650 return (error);
651 }
652
653 KASSERT(VOP_ISLOCKED(rvp) == LK_EXCLUSIVE);
654
655 error = ulfs_extattr_lookup(rvp, 0,
656 ULFS_EXTATTR_FSROOTSUBDIR, &attr_dvp, l);
657 if (error) {
658 /* rvp ref'd but now unlocked */
659 KASSERT(VOP_ISLOCKED(rvp) == 0);
660 vrele(rvp);
661 return (error);
662 }
663 if (rvp == attr_dvp) {
664 /* Should never happen. */
665 KASSERT(VOP_ISLOCKED(rvp) == LK_EXCLUSIVE);
666 vrele(attr_dvp);
667 vput(rvp);
668 return (EINVAL);
669 }
670 KASSERT(VOP_ISLOCKED(rvp) == 0);
671 vrele(rvp);
672
673 KASSERT(VOP_ISLOCKED(attr_dvp) == LK_EXCLUSIVE);
674
675 if (attr_dvp->v_type != VDIR) {
676 printf("ulfs_extattr_autostart: %s != VDIR\n",
677 ULFS_EXTATTR_FSROOTSUBDIR);
678 goto return_vput_attr_dvp;
679 }
680
681 error = ulfs_extattr_start(mp, l);
682 if (error) {
683 printf("ulfs_extattr_autostart: ulfs_extattr_start failed (%d)\n",
684 error);
685 goto return_vput_attr_dvp;
686 }
687
688 /*
689 * Look for two subdirectories: ULFS_EXTATTR_SUBDIR_SYSTEM,
690 * ULFS_EXTATTR_SUBDIR_USER. For each, iterate over the sub-directory,
691 * and start with appropriate type. Failures in either don't
692 * result in an over-all failure. attr_dvp is left locked to
693 * be cleaned up on exit.
694 */
695 error = ulfs_extattr_lookup(attr_dvp, LOCKPARENT,
696 ULFS_EXTATTR_SUBDIR_SYSTEM, &attr_system_dvp, l);
697 KASSERT(VOP_ISLOCKED(attr_dvp) == LK_EXCLUSIVE);
698 if (error == 0) {
699 KASSERT(VOP_ISLOCKED(attr_system_dvp) == LK_EXCLUSIVE);
700 error = ulfs_extattr_iterate_directory(VFSTOULFS(mp),
701 attr_system_dvp, EXTATTR_NAMESPACE_SYSTEM, l);
702 if (error)
703 printf("ulfs_extattr_iterate_directory returned %d\n",
704 error);
705 KASSERT(VOP_ISLOCKED(attr_system_dvp) == LK_EXCLUSIVE);
706 vput(attr_system_dvp);
707 }
708
709 error = ulfs_extattr_lookup(attr_dvp, LOCKPARENT,
710 ULFS_EXTATTR_SUBDIR_USER, &attr_user_dvp, l);
711 KASSERT(VOP_ISLOCKED(attr_dvp) == LK_EXCLUSIVE);
712 if (error == 0) {
713 KASSERT(VOP_ISLOCKED(attr_user_dvp) == LK_EXCLUSIVE);
714 error = ulfs_extattr_iterate_directory(VFSTOULFS(mp),
715 attr_user_dvp, EXTATTR_NAMESPACE_USER, l);
716 if (error)
717 printf("ulfs_extattr_iterate_directory returned %d\n",
718 error);
719 KASSERT(VOP_ISLOCKED(attr_user_dvp) == LK_EXCLUSIVE);
720 vput(attr_user_dvp);
721 }
722
723 /* Mask startup failures in sub-directories. */
724 error = 0;
725
726 return_vput_attr_dvp:
727 KASSERT(VOP_ISLOCKED(attr_dvp) == LK_EXCLUSIVE);
728 vput(attr_dvp);
729
730 return (error);
731 }
732
733 /*
734 * Stop extended attribute support on an FS.
735 */
736 void
ulfs_extattr_stop(struct mount * mp,struct lwp * l)737 ulfs_extattr_stop(struct mount *mp, struct lwp *l)
738 {
739 struct ulfs_extattr_list_entry *uele;
740 struct ulfsmount *ump = VFSTOULFS(mp);
741
742 ulfs_extattr_uepm_lock(ump);
743
744 /*
745 * If we haven't been started, no big deal. Just short-circuit
746 * the processing work.
747 */
748 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_STARTED)) {
749 goto unlock;
750 }
751
752 while (LIST_FIRST(&ump->um_extattr.uepm_list) != NULL) {
753 uele = LIST_FIRST(&ump->um_extattr.uepm_list);
754 ulfs_extattr_disable(ump, uele->uele_attrnamespace,
755 uele->uele_attrname, l);
756 }
757
758 ump->um_extattr.uepm_flags &= ~ULFS_EXTATTR_UEPM_STARTED;
759
760 kauth_cred_free(ump->um_extattr.uepm_ucred);
761 ump->um_extattr.uepm_ucred = NULL;
762
763 unlock:
764 ulfs_extattr_uepm_unlock(ump);
765 }
766
767 /*
768 * Enable a named attribute on the specified filesystem; provide an
769 * unlocked backing vnode to hold the attribute data.
770 */
771 static int
ulfs_extattr_enable(struct ulfsmount * ump,int attrnamespace,const char * attrname,struct vnode * backing_vnode,struct lwp * l)772 ulfs_extattr_enable(struct ulfsmount *ump, int attrnamespace,
773 const char *attrname, struct vnode *backing_vnode, struct lwp *l)
774 {
775 struct ulfs_extattr_list_entry *attribute;
776 struct iovec aiov;
777 struct uio auio;
778 int error = 0;
779
780 if (!ulfs_extattr_valid_attrname(attrnamespace, attrname))
781 return (EINVAL);
782 if (backing_vnode->v_type != VREG)
783 return (EINVAL);
784
785 attribute = kmem_zalloc(sizeof(*attribute), KM_SLEEP);
786
787 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_STARTED)) {
788 error = EOPNOTSUPP;
789 goto free_exit;
790 }
791
792 if (ulfs_extattr_find_attr(ump, attrnamespace, attrname)) {
793 error = EEXIST;
794 goto free_exit;
795 }
796
797 strncpy(attribute->uele_attrname, attrname,
798 ULFS_EXTATTR_MAXEXTATTRNAME);
799 attribute->uele_attrnamespace = attrnamespace;
800 memset(&attribute->uele_fileheader, 0,
801 sizeof(struct ulfs_extattr_fileheader));
802
803 attribute->uele_backing_vnode = backing_vnode;
804
805 auio.uio_iov = &aiov;
806 auio.uio_iovcnt = 1;
807 aiov.iov_base = (void *) &attribute->uele_fileheader;
808 aiov.iov_len = sizeof(struct ulfs_extattr_fileheader);
809 auio.uio_resid = sizeof(struct ulfs_extattr_fileheader);
810 auio.uio_offset = (off_t) 0;
811 auio.uio_rw = UIO_READ;
812 UIO_SETUP_SYSSPACE(&auio);
813
814 vn_lock(backing_vnode, LK_SHARED | LK_RETRY);
815 error = VOP_READ(backing_vnode, &auio, IO_NODELOCKED,
816 ump->um_extattr.uepm_ucred);
817
818 if (error)
819 goto unlock_free_exit;
820
821 if (auio.uio_resid != 0) {
822 printf("ulfs_extattr_enable: malformed attribute header\n");
823 error = EINVAL;
824 goto unlock_free_exit;
825 }
826
827 /*
828 * Try to determine the byte order of the attribute file.
829 */
830 if (attribute->uele_fileheader.uef_magic != ULFS_EXTATTR_MAGIC) {
831 attribute->uele_flags |= UELE_F_NEEDSWAP;
832 attribute->uele_fileheader.uef_magic =
833 ulfs_rw32(attribute->uele_fileheader.uef_magic,
834 UELE_NEEDSWAP(attribute));
835 if (attribute->uele_fileheader.uef_magic != ULFS_EXTATTR_MAGIC) {
836 printf("ulfs_extattr_enable: invalid attribute header "
837 "magic\n");
838 error = EINVAL;
839 goto unlock_free_exit;
840 }
841 }
842 attribute->uele_fileheader.uef_version =
843 ulfs_rw32(attribute->uele_fileheader.uef_version,
844 UELE_NEEDSWAP(attribute));
845 attribute->uele_fileheader.uef_size =
846 ulfs_rw32(attribute->uele_fileheader.uef_size,
847 UELE_NEEDSWAP(attribute));
848
849 if (attribute->uele_fileheader.uef_version != ULFS_EXTATTR_VERSION) {
850 printf("ulfs_extattr_enable: incorrect attribute header "
851 "version\n");
852 error = EINVAL;
853 goto unlock_free_exit;
854 }
855
856 LIST_INSERT_HEAD(&ump->um_extattr.uepm_list, attribute,
857 uele_entries);
858
859 VOP_UNLOCK(backing_vnode);
860 return (0);
861
862 unlock_free_exit:
863 VOP_UNLOCK(backing_vnode);
864
865 free_exit:
866 kmem_free(attribute, sizeof(*attribute));
867 return (error);
868 }
869
870 /*
871 * Disable extended attribute support on an FS.
872 */
873 static int
ulfs_extattr_disable(struct ulfsmount * ump,int attrnamespace,const char * attrname,struct lwp * l)874 ulfs_extattr_disable(struct ulfsmount *ump, int attrnamespace,
875 const char *attrname, struct lwp *l)
876 {
877 struct ulfs_extattr_list_entry *uele;
878 int error = 0;
879
880 if (!ulfs_extattr_valid_attrname(attrnamespace, attrname))
881 return (EINVAL);
882
883 uele = ulfs_extattr_find_attr(ump, attrnamespace, attrname);
884 if (!uele)
885 return (ENODATA);
886
887 LIST_REMOVE(uele, uele_entries);
888
889 error = vn_close(uele->uele_backing_vnode, FREAD|FWRITE,
890 l->l_cred);
891
892 kmem_free(uele, sizeof(*uele));
893
894 return (error);
895 }
896
897 /*
898 * VFS call to manage extended attributes in ULFS. If filename_vp is
899 * non-NULL, it must be passed in locked, and regardless of errors in
900 * processing, will be unlocked.
901 */
902 int
ulfs_extattrctl(struct mount * mp,int cmd,struct vnode * filename_vp,int attrnamespace,const char * attrname)903 ulfs_extattrctl(struct mount *mp, int cmd, struct vnode *filename_vp,
904 int attrnamespace, const char *attrname)
905 {
906 struct lwp *l = curlwp;
907 struct ulfsmount *ump = VFSTOULFS(mp);
908 int error;
909
910 /*
911 * Only privileged processes can configure extended attributes.
912 */
913 error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_FS_EXTATTR,
914 0, mp, NULL, NULL);
915 if (error) {
916 if (filename_vp != NULL)
917 VOP_UNLOCK(filename_vp);
918 return (error);
919 }
920
921 switch(cmd) {
922 case ULFS_EXTATTR_CMD_START:
923 if (filename_vp != NULL) {
924 VOP_UNLOCK(filename_vp);
925 return (EINVAL);
926 }
927 if (attrname != NULL)
928 return (EINVAL);
929
930 error = ulfs_extattr_autostart(mp, l);
931 return (error);
932
933 case ULFS_EXTATTR_CMD_STOP:
934 if (filename_vp != NULL) {
935 VOP_UNLOCK(filename_vp);
936 return (EINVAL);
937 }
938 if (attrname != NULL)
939 return (EINVAL);
940
941 ulfs_extattr_stop(mp, l);
942 return (0);
943
944 case ULFS_EXTATTR_CMD_ENABLE:
945 if (filename_vp == NULL)
946 return (EINVAL);
947 if (attrname == NULL) {
948 VOP_UNLOCK(filename_vp);
949 return (EINVAL);
950 }
951
952 /*
953 * ulfs_extattr_enable_with_open() will always unlock the
954 * vnode, regardless of failure.
955 */
956 ulfs_extattr_uepm_lock(ump);
957 error = ulfs_extattr_enable_with_open(ump, filename_vp,
958 attrnamespace, attrname, l);
959 ulfs_extattr_uepm_unlock(ump);
960 return (error);
961
962 case ULFS_EXTATTR_CMD_DISABLE:
963 if (filename_vp != NULL) {
964 VOP_UNLOCK(filename_vp);
965 return (EINVAL);
966 }
967 if (attrname == NULL)
968 return (EINVAL);
969
970 ulfs_extattr_uepm_lock(ump);
971 error = ulfs_extattr_disable(ump, attrnamespace, attrname, l);
972 ulfs_extattr_uepm_unlock(ump);
973 return (error);
974
975 default:
976 return (EINVAL);
977 }
978 }
979
980 /*
981 * Read extended attribute header for a given vnode and attribute.
982 * Backing vnode should be locked and unlocked by caller.
983 */
984 static int
ulfs_extattr_get_header(struct vnode * vp,struct ulfs_extattr_list_entry * uele,struct ulfs_extattr_header * ueh,off_t * bap)985 ulfs_extattr_get_header(struct vnode *vp, struct ulfs_extattr_list_entry *uele,
986 struct ulfs_extattr_header *ueh, off_t *bap)
987 {
988 struct mount *mp = vp->v_mount;
989 struct ulfsmount *ump = VFSTOULFS(mp);
990 struct inode *ip = VTOI(vp);
991 off_t base_offset;
992 struct iovec aiov;
993 struct uio aio;
994 int error;
995
996 /*
997 * Find base offset of header in file based on file header size, and
998 * data header size + maximum data size, indexed by inode number.
999 */
1000 base_offset = sizeof(struct ulfs_extattr_fileheader) +
1001 ip->i_number * (sizeof(struct ulfs_extattr_header) +
1002 uele->uele_fileheader.uef_size);
1003
1004 /*
1005 * Read in the data header to see if the data is defined, and if so
1006 * how much.
1007 */
1008 memset(ueh, 0, sizeof(struct ulfs_extattr_header));
1009 aiov.iov_base = ueh;
1010 aiov.iov_len = sizeof(struct ulfs_extattr_header);
1011 aio.uio_iov = &aiov;
1012 aio.uio_iovcnt = 1;
1013 aio.uio_rw = UIO_READ;
1014 aio.uio_offset = base_offset;
1015 aio.uio_resid = sizeof(struct ulfs_extattr_header);
1016 UIO_SETUP_SYSSPACE(&aio);
1017
1018 error = VOP_READ(uele->uele_backing_vnode, &aio,
1019 IO_NODELOCKED, ump->um_extattr.uepm_ucred);
1020 if (error)
1021 return error;
1022
1023 /*
1024 * Attribute headers are kept in file system byte order.
1025 * XXX What about the blob of data?
1026 */
1027 ueh->ueh_flags = ulfs_rw32(ueh->ueh_flags, UELE_NEEDSWAP(uele));
1028 ueh->ueh_len = ulfs_rw32(ueh->ueh_len, UELE_NEEDSWAP(uele));
1029 ueh->ueh_i_gen = ulfs_rw32(ueh->ueh_i_gen, UELE_NEEDSWAP(uele));
1030
1031 /* Defined? */
1032 if ((ueh->ueh_flags & ULFS_EXTATTR_ATTR_FLAG_INUSE) == 0)
1033 return ENODATA;
1034
1035 /* Valid for the current inode generation? */
1036 if (ueh->ueh_i_gen != ip->i_gen) {
1037 /*
1038 * The inode itself has a different generation number
1039 * than the uele data. For now, the best solution
1040 * is to coerce this to undefined, and let it get cleaned
1041 * up by the next write or extattrctl clean.
1042 */
1043 printf("%s (%s): inode gen inconsistency (%u, %jd)\n",
1044 __func__, mp->mnt_stat.f_mntonname, ueh->ueh_i_gen,
1045 (intmax_t)ip->i_gen);
1046 return ENODATA;
1047 }
1048
1049 /* Local size consistency check. */
1050 if (ueh->ueh_len > uele->uele_fileheader.uef_size)
1051 return ENXIO;
1052
1053 /* Return base offset */
1054 if (bap != NULL)
1055 *bap = base_offset;
1056
1057 return 0;
1058 }
1059
1060 /*
1061 * Vnode operation to retrieve a named extended attribute.
1062 */
1063 int
ulfs_getextattr(struct vop_getextattr_args * ap)1064 ulfs_getextattr(struct vop_getextattr_args *ap)
1065 /*
1066 vop_getextattr {
1067 IN struct vnode *a_vp;
1068 IN int a_attrnamespace;
1069 IN const char *a_name;
1070 INOUT struct uio *a_uio;
1071 OUT size_t *a_size;
1072 IN kauth_cred_t a_cred;
1073 };
1074 */
1075 {
1076 struct mount *mp = ap->a_vp->v_mount;
1077 struct ulfsmount *ump = VFSTOULFS(mp);
1078 int error;
1079
1080 ulfs_extattr_uepm_lock(ump);
1081
1082 error = ulfs_extattr_get(ap->a_vp, ap->a_attrnamespace, ap->a_name,
1083 ap->a_uio, ap->a_size, ap->a_cred, curlwp);
1084
1085 ulfs_extattr_uepm_unlock(ump);
1086
1087 return (error);
1088 }
1089
1090 /*
1091 * Real work associated with retrieving a named attribute--assumes that
1092 * the attribute lock has already been grabbed.
1093 */
1094 static int
ulfs_extattr_get(struct vnode * vp,int attrnamespace,const char * name,struct uio * uio,size_t * size,kauth_cred_t cred,struct lwp * l)1095 ulfs_extattr_get(struct vnode *vp, int attrnamespace, const char *name,
1096 struct uio *uio, size_t *size, kauth_cred_t cred, struct lwp *l)
1097 {
1098 struct ulfs_extattr_list_entry *attribute;
1099 struct ulfs_extattr_header ueh;
1100 struct mount *mp = vp->v_mount;
1101 struct ulfsmount *ump = VFSTOULFS(mp);
1102 off_t base_offset;
1103 size_t len, old_len;
1104 int error = 0;
1105
1106 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_STARTED))
1107 return (EOPNOTSUPP);
1108
1109 if (strlen(name) == 0)
1110 return (EINVAL);
1111
1112 error = internal_extattr_check_cred(vp, attrnamespace, name, cred,
1113 VREAD);
1114 if (error)
1115 return (error);
1116
1117 attribute = ulfs_extattr_find_attr(ump, attrnamespace, name);
1118 if (!attribute)
1119 return (ENODATA);
1120
1121 /*
1122 * Allow only offsets of zero to encourage the read/replace
1123 * extended attribute semantic. Otherwise we can't guarantee
1124 * atomicity, as we don't provide locks for extended attributes.
1125 */
1126 if (uio != NULL && uio->uio_offset != 0)
1127 return (ENXIO);
1128
1129 /*
1130 * Don't need to get a lock on the backing file if the getattr is
1131 * being applied to the backing file, as the lock is already held.
1132 */
1133 if (attribute->uele_backing_vnode != vp)
1134 vn_lock(attribute->uele_backing_vnode, LK_SHARED | LK_RETRY);
1135
1136 error = ulfs_extattr_get_header(vp, attribute, &ueh, &base_offset);
1137 if (error)
1138 goto vopunlock_exit;
1139
1140 /* Return full data size if caller requested it. */
1141 if (size != NULL)
1142 *size = ueh.ueh_len;
1143
1144 /* Return data if the caller requested it. */
1145 if (uio != NULL) {
1146 /* Allow for offset into the attribute data. */
1147 uio->uio_offset = base_offset + sizeof(struct
1148 ulfs_extattr_header);
1149
1150 /*
1151 * Figure out maximum to transfer -- use buffer size and
1152 * local data limit.
1153 */
1154 len = MIN(uio->uio_resid, ueh.ueh_len);
1155 old_len = uio->uio_resid;
1156 uio->uio_resid = len;
1157
1158 error = VOP_READ(attribute->uele_backing_vnode, uio,
1159 IO_NODELOCKED, ump->um_extattr.uepm_ucred);
1160 if (error)
1161 goto vopunlock_exit;
1162
1163 uio->uio_resid = old_len - (len - uio->uio_resid);
1164 }
1165
1166 vopunlock_exit:
1167
1168 if (uio != NULL)
1169 uio->uio_offset = 0;
1170
1171 if (attribute->uele_backing_vnode != vp)
1172 VOP_UNLOCK(attribute->uele_backing_vnode);
1173
1174 return (error);
1175 }
1176
1177 /*
1178 * Vnode operation to list extended attribute for a vnode
1179 */
1180 int
ulfs_listextattr(struct vop_listextattr_args * ap)1181 ulfs_listextattr(struct vop_listextattr_args *ap)
1182 /*
1183 vop_listextattr {
1184 IN struct vnode *a_vp;
1185 IN int a_attrnamespace;
1186 INOUT struct uio *a_uio;
1187 OUT size_t *a_size;
1188 IN int flag;
1189 IN kauth_cred_t a_cred;
1190 struct proc *a_p;
1191 };
1192 */
1193 {
1194 struct mount *mp = ap->a_vp->v_mount;
1195 struct ulfsmount *ump = VFSTOULFS(mp);
1196 int error;
1197
1198 ulfs_extattr_uepm_lock(ump);
1199
1200 error = ulfs_extattr_list(ap->a_vp, ap->a_attrnamespace,
1201 ap->a_uio, ap->a_size, ap->a_flag, ap->a_cred, curlwp);
1202
1203 ulfs_extattr_uepm_unlock(ump);
1204
1205 return (error);
1206 }
1207
1208 /*
1209 * Real work associated with retrieving list of attributes--assumes that
1210 * the attribute lock has already been grabbed.
1211 */
1212 static int
ulfs_extattr_list(struct vnode * vp,int attrnamespace,struct uio * uio,size_t * size,int flag,kauth_cred_t cred,struct lwp * l)1213 ulfs_extattr_list(struct vnode *vp, int attrnamespace,
1214 struct uio *uio, size_t *size, int flag,
1215 kauth_cred_t cred, struct lwp *l)
1216 {
1217 struct ulfs_extattr_list_entry *uele;
1218 struct ulfs_extattr_header ueh;
1219 struct mount *mp = vp->v_mount;
1220 struct ulfsmount *ump = VFSTOULFS(mp);
1221 size_t listsize = 0;
1222 int error = 0;
1223
1224 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_STARTED))
1225 return (EOPNOTSUPP);
1226
1227 /*
1228 * XXX: We can move this inside the loop and iterate on individual
1229 * attributes.
1230 */
1231 error = internal_extattr_check_cred(vp, attrnamespace, "", cred,
1232 VREAD);
1233 if (error)
1234 return (error);
1235
1236 LIST_FOREACH(uele, &ump->um_extattr.uepm_list, uele_entries) {
1237 unsigned char attrnamelen;
1238
1239 if (uele->uele_attrnamespace != attrnamespace)
1240 continue;
1241
1242 error = ulfs_extattr_get_header(vp, uele, &ueh, NULL);
1243 if (error == ENODATA)
1244 continue;
1245 if (error != 0)
1246 return error;
1247
1248 /*
1249 * Don't need to get a lock on the backing file if
1250 * the listattr is being applied to the backing file,
1251 * as the lock is already held.
1252 */
1253 if (uele->uele_backing_vnode != vp)
1254 vn_lock(uele->uele_backing_vnode, LK_SHARED | LK_RETRY);
1255
1256 /*
1257 * +1 for trailing NUL (listxattr flavor)
1258 * or leading name length (extattr_list_file flavor)
1259 */
1260 attrnamelen = strlen(uele->uele_attrname);
1261 listsize += attrnamelen + 1;
1262
1263 /* Return data if the caller requested it. */
1264 if (uio != NULL) {
1265 /*
1266 * We support two flavors. Either NUL-terminated
1267 * strings (a la listxattr), or non NUL-terminated,
1268 * one byte length prefixed strings (for
1269 * extattr_list_file). EXTATTR_LIST_LENPREFIX switches
1270 * that second behavior.
1271 */
1272 if (flag & EXTATTR_LIST_LENPREFIX) {
1273 uint8_t len = (uint8_t)attrnamelen;
1274
1275 /* Copy leading name length */
1276 error = uiomove(&len, sizeof(len), uio);
1277 if (error != 0)
1278 break;
1279 } else {
1280 /* Include trailing NULL */
1281 attrnamelen++;
1282 }
1283
1284 error = uiomove(uele->uele_attrname,
1285 (size_t)attrnamelen, uio);
1286 if (error != 0)
1287 break;
1288 }
1289
1290 if (uele->uele_backing_vnode != vp)
1291 VOP_UNLOCK(uele->uele_backing_vnode);
1292
1293 if (error != 0)
1294 return error;
1295 }
1296
1297 if (uio != NULL)
1298 uio->uio_offset = 0;
1299
1300 /* Return full data size if caller requested it. */
1301 if (size != NULL)
1302 *size = listsize;
1303
1304 return 0;
1305 }
1306
1307 /*
1308 * Vnode operation to remove a named attribute.
1309 */
1310 int
ulfs_deleteextattr(struct vop_deleteextattr_args * ap)1311 ulfs_deleteextattr(struct vop_deleteextattr_args *ap)
1312 /*
1313 vop_deleteextattr {
1314 IN struct vnode *a_vp;
1315 IN int a_attrnamespace;
1316 IN const char *a_name;
1317 IN kauth_cred_t a_cred;
1318 };
1319 */
1320 {
1321 struct mount *mp = ap->a_vp->v_mount;
1322 struct ulfsmount *ump = VFSTOULFS(mp);
1323 int error;
1324
1325 ulfs_extattr_uepm_lock(ump);
1326
1327 error = ulfs_extattr_rm(ap->a_vp, ap->a_attrnamespace, ap->a_name,
1328 ap->a_cred, curlwp);
1329
1330 ulfs_extattr_uepm_unlock(ump);
1331
1332 return (error);
1333 }
1334
1335 /*
1336 * Vnode operation to set a named attribute.
1337 */
1338 int
ulfs_setextattr(struct vop_setextattr_args * ap)1339 ulfs_setextattr(struct vop_setextattr_args *ap)
1340 /*
1341 vop_setextattr {
1342 IN struct vnode *a_vp;
1343 IN int a_attrnamespace;
1344 IN const char *a_name;
1345 INOUT struct uio *a_uio;
1346 IN kauth_cred_t a_cred;
1347 };
1348 */
1349 {
1350 struct mount *mp = ap->a_vp->v_mount;
1351 struct ulfsmount *ump = VFSTOULFS(mp);
1352 int error;
1353
1354 ulfs_extattr_uepm_lock(ump);
1355
1356 /*
1357 * XXX: No longer a supported way to delete extended attributes.
1358 */
1359 if (ap->a_uio == NULL) {
1360 ulfs_extattr_uepm_unlock(ump);
1361 return (EINVAL);
1362 }
1363
1364 error = ulfs_extattr_set(ap->a_vp, ap->a_attrnamespace, ap->a_name,
1365 ap->a_uio, ap->a_cred, curlwp);
1366
1367 ulfs_extattr_uepm_unlock(ump);
1368
1369 return (error);
1370 }
1371
1372 /*
1373 * Real work associated with setting a vnode's extended attributes;
1374 * assumes that the attribute lock has already been grabbed.
1375 */
1376 static int
ulfs_extattr_set(struct vnode * vp,int attrnamespace,const char * name,struct uio * uio,kauth_cred_t cred,struct lwp * l)1377 ulfs_extattr_set(struct vnode *vp, int attrnamespace, const char *name,
1378 struct uio *uio, kauth_cred_t cred, struct lwp *l)
1379 {
1380 struct ulfs_extattr_list_entry *attribute;
1381 struct ulfs_extattr_header ueh;
1382 struct iovec local_aiov;
1383 struct uio local_aio;
1384 struct mount *mp = vp->v_mount;
1385 struct ulfsmount *ump = VFSTOULFS(mp);
1386 struct inode *ip = VTOI(vp);
1387 off_t base_offset;
1388 int error = 0, ioflag;
1389
1390 if (vp->v_mount->mnt_flag & MNT_RDONLY)
1391 return (EROFS);
1392 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_STARTED))
1393 return (EOPNOTSUPP);
1394 if (!ulfs_extattr_valid_attrname(attrnamespace, name))
1395 return (EINVAL);
1396
1397 error = internal_extattr_check_cred(vp, attrnamespace, name, cred,
1398 VWRITE);
1399 if (error)
1400 return (error);
1401
1402 attribute = ulfs_extattr_find_attr(ump, attrnamespace, name);
1403 if (!attribute) {
1404 attribute = ulfs_extattr_autocreate_attr(vp, attrnamespace,
1405 name, l);
1406 if (!attribute)
1407 return (ENODATA);
1408 }
1409
1410 /*
1411 * Early rejection of invalid offsets/length.
1412 * Reject: any offset but 0 (replace)
1413 * Any size greater than attribute size limit
1414 */
1415 if (uio->uio_offset != 0 ||
1416 uio->uio_resid > attribute->uele_fileheader.uef_size)
1417 return (ENXIO);
1418
1419 /*
1420 * Find base offset of header in file based on file header size, and
1421 * data header size + maximum data size, indexed by inode number.
1422 */
1423 base_offset = sizeof(struct ulfs_extattr_fileheader) +
1424 ip->i_number * (sizeof(struct ulfs_extattr_header) +
1425 attribute->uele_fileheader.uef_size);
1426
1427 /*
1428 * Write out a data header for the data.
1429 */
1430 ueh.ueh_len = ulfs_rw32((uint32_t) uio->uio_resid,
1431 UELE_NEEDSWAP(attribute));
1432 ueh.ueh_flags = ulfs_rw32(ULFS_EXTATTR_ATTR_FLAG_INUSE,
1433 UELE_NEEDSWAP(attribute));
1434 ueh.ueh_i_gen = ulfs_rw32(ip->i_gen, UELE_NEEDSWAP(attribute));
1435 local_aiov.iov_base = &ueh;
1436 local_aiov.iov_len = sizeof(struct ulfs_extattr_header);
1437 local_aio.uio_iov = &local_aiov;
1438 local_aio.uio_iovcnt = 1;
1439 local_aio.uio_rw = UIO_WRITE;
1440 local_aio.uio_offset = base_offset;
1441 local_aio.uio_resid = sizeof(struct ulfs_extattr_header);
1442 UIO_SETUP_SYSSPACE(&local_aio);
1443
1444 /*
1445 * Don't need to get a lock on the backing file if the setattr is
1446 * being applied to the backing file, as the lock is already held.
1447 */
1448 if (attribute->uele_backing_vnode != vp)
1449 vn_lock(attribute->uele_backing_vnode,
1450 LK_EXCLUSIVE | LK_RETRY);
1451
1452 ioflag = IO_NODELOCKED;
1453 if (ulfs_extattr_sync)
1454 ioflag |= IO_SYNC;
1455 error = VOP_WRITE(attribute->uele_backing_vnode, &local_aio, ioflag,
1456 ump->um_extattr.uepm_ucred);
1457 if (error)
1458 goto vopunlock_exit;
1459
1460 if (local_aio.uio_resid != 0) {
1461 error = ENXIO;
1462 goto vopunlock_exit;
1463 }
1464
1465 /*
1466 * Write out user data.
1467 * XXX NOT ATOMIC WITH RESPECT TO THE HEADER.
1468 */
1469 uio->uio_offset = base_offset + sizeof(struct ulfs_extattr_header);
1470
1471 ioflag = IO_NODELOCKED;
1472 if (ulfs_extattr_sync)
1473 ioflag |= IO_SYNC;
1474 error = VOP_WRITE(attribute->uele_backing_vnode, uio, ioflag,
1475 ump->um_extattr.uepm_ucred);
1476
1477 vopunlock_exit:
1478 uio->uio_offset = 0;
1479
1480 if (attribute->uele_backing_vnode != vp)
1481 VOP_UNLOCK(attribute->uele_backing_vnode);
1482
1483 return (error);
1484 }
1485
1486 /*
1487 * Real work associated with removing an extended attribute from a vnode.
1488 * Assumes the attribute lock has already been grabbed.
1489 */
1490 static int
ulfs_extattr_rm(struct vnode * vp,int attrnamespace,const char * name,kauth_cred_t cred,struct lwp * l)1491 ulfs_extattr_rm(struct vnode *vp, int attrnamespace, const char *name,
1492 kauth_cred_t cred, struct lwp *l)
1493 {
1494 struct ulfs_extattr_list_entry *attribute;
1495 struct ulfs_extattr_header ueh;
1496 struct mount *mp = vp->v_mount;
1497 struct ulfsmount *ump = VFSTOULFS(mp);
1498 struct iovec local_aiov;
1499 struct uio local_aio;
1500 off_t base_offset;
1501 int error = 0, ioflag;
1502
1503 if (vp->v_mount->mnt_flag & MNT_RDONLY)
1504 return (EROFS);
1505 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_STARTED))
1506 return (EOPNOTSUPP);
1507 if (!ulfs_extattr_valid_attrname(attrnamespace, name))
1508 return (EINVAL);
1509
1510 error = internal_extattr_check_cred(vp, attrnamespace, name, cred,
1511 VWRITE);
1512 if (error)
1513 return (error);
1514
1515 attribute = ulfs_extattr_find_attr(ump, attrnamespace, name);
1516 if (!attribute)
1517 return (ENODATA);
1518
1519 /*
1520 * Don't need to get a lock on the backing file if the getattr is
1521 * being applied to the backing file, as the lock is already held.
1522 */
1523 if (attribute->uele_backing_vnode != vp)
1524 vn_lock(attribute->uele_backing_vnode, LK_EXCLUSIVE | LK_RETRY);
1525
1526 error = ulfs_extattr_get_header(vp, attribute, &ueh, &base_offset);
1527 if (error)
1528 goto vopunlock_exit;
1529
1530 /* Flag it as not in use. */
1531 ueh.ueh_flags = 0; /* No need to byte swap 0 */
1532 ueh.ueh_len = 0; /* ...ditto... */
1533
1534 local_aiov.iov_base = &ueh;
1535 local_aiov.iov_len = sizeof(struct ulfs_extattr_header);
1536 local_aio.uio_iov = &local_aiov;
1537 local_aio.uio_iovcnt = 1;
1538 local_aio.uio_rw = UIO_WRITE;
1539 local_aio.uio_offset = base_offset;
1540 local_aio.uio_resid = sizeof(struct ulfs_extattr_header);
1541 UIO_SETUP_SYSSPACE(&local_aio);
1542
1543 ioflag = IO_NODELOCKED;
1544 if (ulfs_extattr_sync)
1545 ioflag |= IO_SYNC;
1546 error = VOP_WRITE(attribute->uele_backing_vnode, &local_aio, ioflag,
1547 ump->um_extattr.uepm_ucred);
1548 if (error)
1549 goto vopunlock_exit;
1550
1551 if (local_aio.uio_resid != 0)
1552 error = ENXIO;
1553
1554 vopunlock_exit:
1555 VOP_UNLOCK(attribute->uele_backing_vnode);
1556
1557 return (error);
1558 }
1559
1560 /*
1561 * Called by ULFS when an inode is no longer active and should have its
1562 * attributes stripped.
1563 */
1564 void
ulfs_extattr_vnode_inactive(struct vnode * vp,struct lwp * l)1565 ulfs_extattr_vnode_inactive(struct vnode *vp, struct lwp *l)
1566 {
1567 struct ulfs_extattr_list_entry *uele;
1568 struct mount *mp = vp->v_mount;
1569 struct ulfsmount *ump = VFSTOULFS(mp);
1570
1571 /*
1572 * In that case, we cannot lock. We should not have any active vnodes
1573 * on the fs if this is not yet initialized but is going to be, so
1574 * this can go unlocked.
1575 */
1576 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_INITIALIZED))
1577 return;
1578
1579 ulfs_extattr_uepm_lock(ump);
1580
1581 if (!(ump->um_extattr.uepm_flags & ULFS_EXTATTR_UEPM_STARTED)) {
1582 ulfs_extattr_uepm_unlock(ump);
1583 return;
1584 }
1585
1586 LIST_FOREACH(uele, &ump->um_extattr.uepm_list, uele_entries)
1587 ulfs_extattr_rm(vp, uele->uele_attrnamespace,
1588 uele->uele_attrname, lwp0.l_cred, l);
1589
1590 ulfs_extattr_uepm_unlock(ump);
1591 }
1592
1593 void
ulfs_extattr_init(void)1594 ulfs_extattr_init(void)
1595 {
1596
1597 }
1598
1599 void
ulfs_extattr_done(void)1600 ulfs_extattr_done(void)
1601 {
1602
1603 }
1604