FreeBSD/Linux Kernel Cross Reference
sys/kern/kern_acl.c
1 /*-
2 * Copyright (c) 1999-2003 Robert N. M. Watson
3 * All rights reserved.
4 *
5 * This software was developed by Robert Watson for the TrustedBSD Project.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28 /*
29 * Developed by the TrustedBSD Project.
30 * Support for POSIX.1e access control lists.
31 */
32
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD: releng/6.1/sys/kern/kern_acl.c 158179 2006-04-30 16:44:43Z cvs2svn $");
35
36 #include "opt_mac.h"
37
38 #include <sys/param.h>
39 #include <sys/systm.h>
40 #include <sys/sysproto.h>
41 #include <sys/kernel.h>
42 #include <sys/mac.h>
43 #include <sys/malloc.h>
44 #include <sys/mount.h>
45 #include <sys/vnode.h>
46 #include <sys/lock.h>
47 #include <sys/mutex.h>
48 #include <sys/namei.h>
49 #include <sys/file.h>
50 #include <sys/filedesc.h>
51 #include <sys/proc.h>
52 #include <sys/sysent.h>
53 #include <sys/errno.h>
54 #include <sys/stat.h>
55 #include <sys/acl.h>
56
57 #include <vm/uma.h>
58
59 uma_zone_t acl_zone;
60 static int vacl_set_acl(struct thread *td, struct vnode *vp,
61 acl_type_t type, struct acl *aclp);
62 static int vacl_get_acl(struct thread *td, struct vnode *vp,
63 acl_type_t type, struct acl *aclp);
64 static int vacl_aclcheck(struct thread *td, struct vnode *vp,
65 acl_type_t type, struct acl *aclp);
66
67 /*
68 * Implement a version of vaccess() that understands POSIX.1e ACL semantics.
69 * Return 0 on success, else an errno value. Should be merged into
70 * vaccess() eventually.
71 */
72 int
73 vaccess_acl_posix1e(enum vtype type, uid_t file_uid, gid_t file_gid,
74 struct acl *acl, mode_t acc_mode, struct ucred *cred, int *privused)
75 {
76 struct acl_entry *acl_other, *acl_mask;
77 mode_t dac_granted;
78 mode_t cap_granted;
79 mode_t acl_mask_granted;
80 int group_matched, i;
81
82 /*
83 * Look for a normal, non-privileged way to access the file/directory
84 * as requested. If it exists, go with that. Otherwise, attempt
85 * to use privileges granted via cap_granted. In some cases,
86 * which privileges to use may be ambiguous due to "best match",
87 * in which case fall back on first match for the time being.
88 */
89 if (privused != NULL)
90 *privused = 0;
91
92 /*
93 * Determine privileges now, but don't apply until we've found
94 * a DAC entry that matches but has failed to allow access.
95 */
96 #ifndef CAPABILITIES
97 if (suser_cred(cred, SUSER_ALLOWJAIL) == 0)
98 cap_granted = VALLPERM;
99 else
100 cap_granted = 0;
101 #else
102 cap_granted = 0;
103
104 if (type == VDIR) {
105 if ((acc_mode & VEXEC) && !cap_check(cred, NULL,
106 CAP_DAC_READ_SEARCH, SUSER_ALLOWJAIL))
107 cap_granted |= VEXEC;
108 } else {
109 if ((acc_mode & VEXEC) && !cap_check(cred, NULL,
110 CAP_DAC_EXECUTE, SUSER_ALLOWJAIL))
111 cap_granted |= VEXEC;
112 }
113
114 if ((acc_mode & VREAD) && !cap_check(cred, NULL, CAP_DAC_READ_SEARCH,
115 SUSER_ALLOWJAIL))
116 cap_granted |= VREAD;
117
118 if (((acc_mode & VWRITE) || (acc_mode & VAPPEND)) &&
119 !cap_check(cred, NULL, CAP_DAC_WRITE, SUSER_ALLOWJAIL))
120 cap_granted |= (VWRITE | VAPPEND);
121
122 if ((acc_mode & VADMIN) && !cap_check(cred, NULL, CAP_FOWNER,
123 SUSER_ALLOWJAIL))
124 cap_granted |= VADMIN;
125 #endif /* CAPABILITIES */
126
127 /*
128 * The owner matches if the effective uid associated with the
129 * credential matches that of the ACL_USER_OBJ entry. While we're
130 * doing the first scan, also cache the location of the ACL_MASK
131 * and ACL_OTHER entries, preventing some future iterations.
132 */
133 acl_mask = acl_other = NULL;
134 for (i = 0; i < acl->acl_cnt; i++) {
135 switch (acl->acl_entry[i].ae_tag) {
136 case ACL_USER_OBJ:
137 if (file_uid != cred->cr_uid)
138 break;
139 dac_granted = 0;
140 dac_granted |= VADMIN;
141 if (acl->acl_entry[i].ae_perm & ACL_EXECUTE)
142 dac_granted |= VEXEC;
143 if (acl->acl_entry[i].ae_perm & ACL_READ)
144 dac_granted |= VREAD;
145 if (acl->acl_entry[i].ae_perm & ACL_WRITE)
146 dac_granted |= (VWRITE | VAPPEND);
147 if ((acc_mode & dac_granted) == acc_mode)
148 return (0);
149 if ((acc_mode & (dac_granted | cap_granted)) ==
150 acc_mode) {
151 if (privused != NULL)
152 *privused = 1;
153 return (0);
154 }
155 goto error;
156
157 case ACL_MASK:
158 acl_mask = &acl->acl_entry[i];
159 break;
160
161 case ACL_OTHER:
162 acl_other = &acl->acl_entry[i];
163 break;
164
165 default:
166 break;
167 }
168 }
169
170 /*
171 * An ACL_OTHER entry should always exist in a valid access
172 * ACL. If it doesn't, then generate a serious failure. For now,
173 * this means a debugging message and EPERM, but in the future
174 * should probably be a panic.
175 */
176 if (acl_other == NULL) {
177 /*
178 * XXX This should never happen
179 */
180 printf("vaccess_acl_posix1e: ACL_OTHER missing\n");
181 return (EPERM);
182 }
183
184 /*
185 * Checks against ACL_USER, ACL_GROUP_OBJ, and ACL_GROUP fields
186 * are masked by an ACL_MASK entry, if any. As such, first identify
187 * the ACL_MASK field, then iterate through identifying potential
188 * user matches, then group matches. If there is no ACL_MASK,
189 * assume that the mask allows all requests to succeed.
190 */
191 if (acl_mask != NULL) {
192 acl_mask_granted = 0;
193 if (acl_mask->ae_perm & ACL_EXECUTE)
194 acl_mask_granted |= VEXEC;
195 if (acl_mask->ae_perm & ACL_READ)
196 acl_mask_granted |= VREAD;
197 if (acl_mask->ae_perm & ACL_WRITE)
198 acl_mask_granted |= (VWRITE | VAPPEND);
199 } else
200 acl_mask_granted = VEXEC | VREAD | VWRITE | VAPPEND;
201
202 /*
203 * Iterate through user ACL entries. Do checks twice, first
204 * without privilege, and then if a match is found but failed,
205 * a second time with privilege.
206 */
207
208 /*
209 * Check ACL_USER ACL entries.
210 */
211 for (i = 0; i < acl->acl_cnt; i++) {
212 switch (acl->acl_entry[i].ae_tag) {
213 case ACL_USER:
214 if (acl->acl_entry[i].ae_id != cred->cr_uid)
215 break;
216 dac_granted = 0;
217 if (acl->acl_entry[i].ae_perm & ACL_EXECUTE)
218 dac_granted |= VEXEC;
219 if (acl->acl_entry[i].ae_perm & ACL_READ)
220 dac_granted |= VREAD;
221 if (acl->acl_entry[i].ae_perm & ACL_WRITE)
222 dac_granted |= (VWRITE | VAPPEND);
223 dac_granted &= acl_mask_granted;
224 if ((acc_mode & dac_granted) == acc_mode)
225 return (0);
226 if ((acc_mode & (dac_granted | cap_granted)) !=
227 acc_mode)
228 goto error;
229
230 if (privused != NULL)
231 *privused = 1;
232 return (0);
233 }
234 }
235
236 /*
237 * Group match is best-match, not first-match, so find a
238 * "best" match. Iterate across, testing each potential group
239 * match. Make sure we keep track of whether we found a match
240 * or not, so that we know if we should try again with any
241 * available privilege, or if we should move on to ACL_OTHER.
242 */
243 group_matched = 0;
244 for (i = 0; i < acl->acl_cnt; i++) {
245 switch (acl->acl_entry[i].ae_tag) {
246 case ACL_GROUP_OBJ:
247 if (!groupmember(file_gid, cred))
248 break;
249 dac_granted = 0;
250 if (acl->acl_entry[i].ae_perm & ACL_EXECUTE)
251 dac_granted |= VEXEC;
252 if (acl->acl_entry[i].ae_perm & ACL_READ)
253 dac_granted |= VREAD;
254 if (acl->acl_entry[i].ae_perm & ACL_WRITE)
255 dac_granted |= (VWRITE | VAPPEND);
256 dac_granted &= acl_mask_granted;
257
258 if ((acc_mode & dac_granted) == acc_mode)
259 return (0);
260
261 group_matched = 1;
262 break;
263
264 case ACL_GROUP:
265 if (!groupmember(acl->acl_entry[i].ae_id, cred))
266 break;
267 dac_granted = 0;
268 if (acl->acl_entry[i].ae_perm & ACL_EXECUTE)
269 dac_granted |= VEXEC;
270 if (acl->acl_entry[i].ae_perm & ACL_READ)
271 dac_granted |= VREAD;
272 if (acl->acl_entry[i].ae_perm & ACL_WRITE)
273 dac_granted |= (VWRITE | VAPPEND);
274 dac_granted &= acl_mask_granted;
275
276 if ((acc_mode & dac_granted) == acc_mode)
277 return (0);
278
279 group_matched = 1;
280 break;
281
282 default:
283 break;
284 }
285 }
286
287 if (group_matched == 1) {
288 /*
289 * There was a match, but it did not grant rights via
290 * pure DAC. Try again, this time with privilege.
291 */
292 for (i = 0; i < acl->acl_cnt; i++) {
293 switch (acl->acl_entry[i].ae_tag) {
294 case ACL_GROUP_OBJ:
295 if (!groupmember(file_gid, cred))
296 break;
297 dac_granted = 0;
298 if (acl->acl_entry[i].ae_perm & ACL_EXECUTE)
299 dac_granted |= VEXEC;
300 if (acl->acl_entry[i].ae_perm & ACL_READ)
301 dac_granted |= VREAD;
302 if (acl->acl_entry[i].ae_perm & ACL_WRITE)
303 dac_granted |= (VWRITE | VAPPEND);
304 dac_granted &= acl_mask_granted;
305
306 if ((acc_mode & (dac_granted | cap_granted)) !=
307 acc_mode)
308 break;
309
310 if (privused != NULL)
311 *privused = 1;
312 return (0);
313
314 case ACL_GROUP:
315 if (!groupmember(acl->acl_entry[i].ae_id,
316 cred))
317 break;
318 dac_granted = 0;
319 if (acl->acl_entry[i].ae_perm & ACL_EXECUTE)
320 dac_granted |= VEXEC;
321 if (acl->acl_entry[i].ae_perm & ACL_READ)
322 dac_granted |= VREAD;
323 if (acl->acl_entry[i].ae_perm & ACL_WRITE)
324 dac_granted |= (VWRITE | VAPPEND);
325 dac_granted &= acl_mask_granted;
326
327 if ((acc_mode & (dac_granted | cap_granted)) !=
328 acc_mode)
329 break;
330
331 if (privused != NULL)
332 *privused = 1;
333 return (0);
334
335 default:
336 break;
337 }
338 }
339 /*
340 * Even with privilege, group membership was not sufficient.
341 * Return failure.
342 */
343 goto error;
344 }
345
346 /*
347 * Fall back on ACL_OTHER. ACL_MASK is not applied to ACL_OTHER.
348 */
349 dac_granted = 0;
350 if (acl_other->ae_perm & ACL_EXECUTE)
351 dac_granted |= VEXEC;
352 if (acl_other->ae_perm & ACL_READ)
353 dac_granted |= VREAD;
354 if (acl_other->ae_perm & ACL_WRITE)
355 dac_granted |= (VWRITE | VAPPEND);
356
357 if ((acc_mode & dac_granted) == acc_mode)
358 return (0);
359 if ((acc_mode & (dac_granted | cap_granted)) == acc_mode) {
360 if (privused != NULL)
361 *privused = 1;
362 return (0);
363 }
364
365 error:
366 return ((acc_mode & VADMIN) ? EPERM : EACCES);
367 }
368
369 /*
370 * For the purposes of filesystems maintaining the _OBJ entries in an
371 * inode with a mode_t field, this routine converts a mode_t entry
372 * to an acl_perm_t.
373 */
374 acl_perm_t
375 acl_posix1e_mode_to_perm(acl_tag_t tag, mode_t mode)
376 {
377 acl_perm_t perm = 0;
378
379 switch(tag) {
380 case ACL_USER_OBJ:
381 if (mode & S_IXUSR)
382 perm |= ACL_EXECUTE;
383 if (mode & S_IRUSR)
384 perm |= ACL_READ;
385 if (mode & S_IWUSR)
386 perm |= ACL_WRITE;
387 return (perm);
388
389 case ACL_GROUP_OBJ:
390 if (mode & S_IXGRP)
391 perm |= ACL_EXECUTE;
392 if (mode & S_IRGRP)
393 perm |= ACL_READ;
394 if (mode & S_IWGRP)
395 perm |= ACL_WRITE;
396 return (perm);
397
398 case ACL_OTHER:
399 if (mode & S_IXOTH)
400 perm |= ACL_EXECUTE;
401 if (mode & S_IROTH)
402 perm |= ACL_READ;
403 if (mode & S_IWOTH)
404 perm |= ACL_WRITE;
405 return (perm);
406
407 default:
408 printf("acl_posix1e_mode_to_perm: invalid tag (%d)\n", tag);
409 return (0);
410 }
411 }
412
413 /*
414 * Given inode information (uid, gid, mode), return an acl entry of the
415 * appropriate type.
416 */
417 struct acl_entry
418 acl_posix1e_mode_to_entry(acl_tag_t tag, uid_t uid, gid_t gid, mode_t mode)
419 {
420 struct acl_entry acl_entry;
421
422 acl_entry.ae_tag = tag;
423 acl_entry.ae_perm = acl_posix1e_mode_to_perm(tag, mode);
424 switch(tag) {
425 case ACL_USER_OBJ:
426 acl_entry.ae_id = uid;
427 break;
428
429 case ACL_GROUP_OBJ:
430 acl_entry.ae_id = gid;
431 break;
432
433 case ACL_OTHER:
434 acl_entry.ae_id = ACL_UNDEFINED_ID;
435 break;
436
437 default:
438 acl_entry.ae_id = ACL_UNDEFINED_ID;
439 printf("acl_posix1e_mode_to_entry: invalid tag (%d)\n", tag);
440 }
441
442 return (acl_entry);
443 }
444
445 /*
446 * Utility function to generate a file mode given appropriate ACL entries.
447 */
448 mode_t
449 acl_posix1e_perms_to_mode(struct acl_entry *acl_user_obj_entry,
450 struct acl_entry *acl_group_obj_entry, struct acl_entry *acl_other_entry)
451 {
452 mode_t mode;
453
454 mode = 0;
455 if (acl_user_obj_entry->ae_perm & ACL_EXECUTE)
456 mode |= S_IXUSR;
457 if (acl_user_obj_entry->ae_perm & ACL_READ)
458 mode |= S_IRUSR;
459 if (acl_user_obj_entry->ae_perm & ACL_WRITE)
460 mode |= S_IWUSR;
461 if (acl_group_obj_entry->ae_perm & ACL_EXECUTE)
462 mode |= S_IXGRP;
463 if (acl_group_obj_entry->ae_perm & ACL_READ)
464 mode |= S_IRGRP;
465 if (acl_group_obj_entry->ae_perm & ACL_WRITE)
466 mode |= S_IWGRP;
467 if (acl_other_entry->ae_perm & ACL_EXECUTE)
468 mode |= S_IXOTH;
469 if (acl_other_entry->ae_perm & ACL_READ)
470 mode |= S_IROTH;
471 if (acl_other_entry->ae_perm & ACL_WRITE)
472 mode |= S_IWOTH;
473
474 return (mode);
475 }
476
477 /*
478 * Utility function to generate a file mode given a complete POSIX.1e
479 * access ACL. Note that if the ACL is improperly formed, this may
480 * result in a panic.
481 */
482 mode_t
483 acl_posix1e_acl_to_mode(struct acl *acl)
484 {
485 struct acl_entry *acl_mask, *acl_user_obj, *acl_group_obj, *acl_other;
486 int i;
487
488 /*
489 * Find the ACL entries relevant to a POSIX permission mode.
490 */
491 acl_user_obj = acl_group_obj = acl_other = acl_mask = NULL;
492 for (i = 0; i < acl->acl_cnt; i++) {
493 switch (acl->acl_entry[i].ae_tag) {
494 case ACL_USER_OBJ:
495 acl_user_obj = &acl->acl_entry[i];
496 break;
497
498 case ACL_GROUP_OBJ:
499 acl_group_obj = &acl->acl_entry[i];
500 break;
501
502 case ACL_OTHER:
503 acl_other = &acl->acl_entry[i];
504 break;
505
506 case ACL_MASK:
507 acl_mask = &acl->acl_entry[i];
508 break;
509
510 case ACL_USER:
511 case ACL_GROUP:
512 break;
513
514 default:
515 panic("acl_posix1e_acl_to_mode: bad ae_tag");
516 }
517 }
518
519 if (acl_user_obj == NULL || acl_group_obj == NULL || acl_other == NULL)
520 panic("acl_posix1e_acl_to_mode: missing base ae_tags");
521
522 /*
523 * POSIX.1e specifies that if there is an ACL_MASK entry, we replace
524 * the mode "group" bits with its permissions. If there isn't, we
525 * use the ACL_GROUP_OBJ permissions.
526 */
527 if (acl_mask != NULL)
528 return (acl_posix1e_perms_to_mode(acl_user_obj, acl_mask,
529 acl_other));
530 else
531 return (acl_posix1e_perms_to_mode(acl_user_obj, acl_group_obj,
532 acl_other));
533 }
534
535 /*
536 * Perform a syntactic check of the ACL, sufficient to allow an
537 * implementing filesystem to determine if it should accept this and
538 * rely on the POSIX.1e ACL properties.
539 */
540 int
541 acl_posix1e_check(struct acl *acl)
542 {
543 int num_acl_user_obj, num_acl_user, num_acl_group_obj, num_acl_group;
544 int num_acl_mask, num_acl_other, i;
545
546 /*
547 * Verify that the number of entries does not exceed the maximum
548 * defined for acl_t.
549 * Verify that the correct number of various sorts of ae_tags are
550 * present:
551 * Exactly one ACL_USER_OBJ
552 * Exactly one ACL_GROUP_OBJ
553 * Exactly one ACL_OTHER
554 * If any ACL_USER or ACL_GROUP entries appear, then exactly one
555 * ACL_MASK entry must also appear.
556 * Verify that all ae_perm entries are in ACL_PERM_BITS.
557 * Verify all ae_tag entries are understood by this implementation.
558 * Note: Does not check for uniqueness of qualifier (ae_id) field.
559 */
560 num_acl_user_obj = num_acl_user = num_acl_group_obj = num_acl_group =
561 num_acl_mask = num_acl_other = 0;
562 if (acl->acl_cnt > ACL_MAX_ENTRIES || acl->acl_cnt < 0)
563 return (EINVAL);
564 for (i = 0; i < acl->acl_cnt; i++) {
565 /*
566 * Check for a valid tag.
567 */
568 switch(acl->acl_entry[i].ae_tag) {
569 case ACL_USER_OBJ:
570 acl->acl_entry[i].ae_id = ACL_UNDEFINED_ID; /* XXX */
571 if (acl->acl_entry[i].ae_id != ACL_UNDEFINED_ID)
572 return (EINVAL);
573 num_acl_user_obj++;
574 break;
575 case ACL_GROUP_OBJ:
576 acl->acl_entry[i].ae_id = ACL_UNDEFINED_ID; /* XXX */
577 if (acl->acl_entry[i].ae_id != ACL_UNDEFINED_ID)
578 return (EINVAL);
579 num_acl_group_obj++;
580 break;
581 case ACL_USER:
582 if (acl->acl_entry[i].ae_id == ACL_UNDEFINED_ID)
583 return (EINVAL);
584 num_acl_user++;
585 break;
586 case ACL_GROUP:
587 if (acl->acl_entry[i].ae_id == ACL_UNDEFINED_ID)
588 return (EINVAL);
589 num_acl_group++;
590 break;
591 case ACL_OTHER:
592 acl->acl_entry[i].ae_id = ACL_UNDEFINED_ID; /* XXX */
593 if (acl->acl_entry[i].ae_id != ACL_UNDEFINED_ID)
594 return (EINVAL);
595 num_acl_other++;
596 break;
597 case ACL_MASK:
598 acl->acl_entry[i].ae_id = ACL_UNDEFINED_ID; /* XXX */
599 if (acl->acl_entry[i].ae_id != ACL_UNDEFINED_ID)
600 return (EINVAL);
601 num_acl_mask++;
602 break;
603 default:
604 return (EINVAL);
605 }
606 /*
607 * Check for valid perm entries.
608 */
609 if ((acl->acl_entry[i].ae_perm | ACL_PERM_BITS) !=
610 ACL_PERM_BITS)
611 return (EINVAL);
612 }
613 if ((num_acl_user_obj != 1) || (num_acl_group_obj != 1) ||
614 (num_acl_other != 1) || (num_acl_mask != 0 && num_acl_mask != 1))
615 return (EINVAL);
616 if (((num_acl_group != 0) || (num_acl_user != 0)) &&
617 (num_acl_mask != 1))
618 return (EINVAL);
619 return (0);
620 }
621
622 /*
623 * Given a requested mode for a new object, and a default ACL, combine
624 * the two to produce a new mode. Be careful not to clear any bits that
625 * aren't intended to be affected by the POSIX.1e ACL. Eventually,
626 * this might also take the cmask as an argument, if we push that down
627 * into per-filesystem-code.
628 */
629 mode_t
630 acl_posix1e_newfilemode(mode_t cmode, struct acl *dacl)
631 {
632 mode_t mode;
633
634 mode = cmode;
635 /*
636 * The current composition policy is that a permission bit must
637 * be set in *both* the ACL and the requested creation mode for
638 * it to appear in the resulting mode/ACL. First clear any
639 * possibly effected bits, then reconstruct.
640 */
641 mode &= ACL_PRESERVE_MASK;
642 mode |= (ACL_OVERRIDE_MASK & cmode & acl_posix1e_acl_to_mode(dacl));
643
644 return (mode);
645 }
646
647 /*
648 * These calls wrap the real vnode operations, and are called by the
649 * syscall code once the syscall has converted the path or file
650 * descriptor to a vnode (unlocked). The aclp pointer is assumed
651 * still to point to userland, so this should not be consumed within
652 * the kernel except by syscall code. Other code should directly
653 * invoke VOP_{SET,GET}ACL.
654 */
655
656 /*
657 * Given a vnode, set its ACL.
658 */
659 static int
660 vacl_set_acl(struct thread *td, struct vnode *vp, acl_type_t type,
661 struct acl *aclp)
662 {
663 struct acl inkernacl;
664 struct mount *mp;
665 int error;
666
667 error = copyin(aclp, &inkernacl, sizeof(struct acl));
668 if (error)
669 return(error);
670 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
671 if (error != 0)
672 return (error);
673 VOP_LEASE(vp, td, td->td_ucred, LEASE_WRITE);
674 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
675 #ifdef MAC
676 error = mac_check_vnode_setacl(td->td_ucred, vp, type, &inkernacl);
677 if (error != 0)
678 goto out;
679 #endif
680 error = VOP_SETACL(vp, type, &inkernacl, td->td_ucred, td);
681 #ifdef MAC
682 out:
683 #endif
684 VOP_UNLOCK(vp, 0, td);
685 vn_finished_write(mp);
686 return(error);
687 }
688
689 /*
690 * Given a vnode, get its ACL.
691 */
692 static int
693 vacl_get_acl(struct thread *td, struct vnode *vp, acl_type_t type,
694 struct acl *aclp)
695 {
696 struct acl inkernelacl;
697 int error;
698
699 VOP_LEASE(vp, td, td->td_ucred, LEASE_WRITE);
700 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
701 #ifdef MAC
702 error = mac_check_vnode_getacl(td->td_ucred, vp, type);
703 if (error != 0)
704 goto out;
705 #endif
706 error = VOP_GETACL(vp, type, &inkernelacl, td->td_ucred, td);
707 #ifdef MAC
708 out:
709 #endif
710 VOP_UNLOCK(vp, 0, td);
711 if (error == 0)
712 error = copyout(&inkernelacl, aclp, sizeof(struct acl));
713 return (error);
714 }
715
716 /*
717 * Given a vnode, delete its ACL.
718 */
719 static int
720 vacl_delete(struct thread *td, struct vnode *vp, acl_type_t type)
721 {
722 struct mount *mp;
723 int error;
724
725 error = vn_start_write(vp, &mp, V_WAIT | PCATCH);
726 if (error)
727 return (error);
728 VOP_LEASE(vp, td, td->td_ucred, LEASE_WRITE);
729 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, td);
730 #ifdef MAC
731 error = mac_check_vnode_deleteacl(td->td_ucred, vp, type);
732 if (error)
733 goto out;
734 #endif
735 error = VOP_SETACL(vp, type, 0, td->td_ucred, td);
736 #ifdef MAC
737 out:
738 #endif
739 VOP_UNLOCK(vp, 0, td);
740 vn_finished_write(mp);
741 return (error);
742 }
743
744 /*
745 * Given a vnode, check whether an ACL is appropriate for it
746 */
747 static int
748 vacl_aclcheck(struct thread *td, struct vnode *vp, acl_type_t type,
749 struct acl *aclp)
750 {
751 struct acl inkernelacl;
752 int error;
753
754 error = copyin(aclp, &inkernelacl, sizeof(struct acl));
755 if (error)
756 return(error);
757 error = VOP_ACLCHECK(vp, type, &inkernelacl, td->td_ucred, td);
758 return (error);
759 }
760
761 /*
762 * syscalls -- convert the path/fd to a vnode, and call vacl_whatever.
763 * Don't need to lock, as the vacl_ code will get/release any locks
764 * required.
765 */
766
767 /*
768 * Given a file path, get an ACL for it
769 *
770 * MPSAFE
771 */
772 int
773 __acl_get_file(struct thread *td, struct __acl_get_file_args *uap)
774 {
775 struct nameidata nd;
776 int vfslocked, error;
777
778 NDINIT(&nd, LOOKUP, MPSAFE|FOLLOW, UIO_USERSPACE, uap->path, td);
779 error = namei(&nd);
780 vfslocked = NDHASGIANT(&nd);
781 if (error == 0) {
782 error = vacl_get_acl(td, nd.ni_vp, uap->type, uap->aclp);
783 NDFREE(&nd, 0);
784 }
785 VFS_UNLOCK_GIANT(vfslocked);
786 return (error);
787 }
788
789 /*
790 * Given a file path, get an ACL for it; don't follow links.
791 *
792 * MPSAFE
793 */
794 int
795 __acl_get_link(struct thread *td, struct __acl_get_link_args *uap)
796 {
797 struct nameidata nd;
798 int vfslocked, error;
799
800 NDINIT(&nd, LOOKUP, MPSAFE|NOFOLLOW, UIO_USERSPACE, uap->path, td);
801 error = namei(&nd);
802 vfslocked = NDHASGIANT(&nd);
803 if (error == 0) {
804 error = vacl_get_acl(td, nd.ni_vp, uap->type, uap->aclp);
805 NDFREE(&nd, 0);
806 }
807 VFS_UNLOCK_GIANT(vfslocked);
808 return (error);
809 }
810
811 /*
812 * Given a file path, set an ACL for it
813 *
814 * MPSAFE
815 */
816 int
817 __acl_set_file(struct thread *td, struct __acl_set_file_args *uap)
818 {
819 struct nameidata nd;
820 int vfslocked, error;
821
822 NDINIT(&nd, LOOKUP, MPSAFE|FOLLOW, UIO_USERSPACE, uap->path, td);
823 error = namei(&nd);
824 vfslocked = NDHASGIANT(&nd);
825 if (error == 0) {
826 error = vacl_set_acl(td, nd.ni_vp, uap->type, uap->aclp);
827 NDFREE(&nd, 0);
828 }
829 VFS_UNLOCK_GIANT(vfslocked);
830 return (error);
831 }
832
833 /*
834 * Given a file path, set an ACL for it; don't follow links.
835 *
836 * MPSAFE
837 */
838 int
839 __acl_set_link(struct thread *td, struct __acl_set_link_args *uap)
840 {
841 struct nameidata nd;
842 int vfslocked, error;
843
844 NDINIT(&nd, LOOKUP, MPSAFE|NOFOLLOW, UIO_USERSPACE, uap->path, td);
845 error = namei(&nd);
846 vfslocked = NDHASGIANT(&nd);
847 if (error == 0) {
848 error = vacl_set_acl(td, nd.ni_vp, uap->type, uap->aclp);
849 NDFREE(&nd, 0);
850 }
851 VFS_UNLOCK_GIANT(vfslocked);
852 return (error);
853 }
854
855 /*
856 * Given a file descriptor, get an ACL for it
857 *
858 * MPSAFE
859 */
860 int
861 __acl_get_fd(struct thread *td, struct __acl_get_fd_args *uap)
862 {
863 struct file *fp;
864 int vfslocked, error;
865
866 error = getvnode(td->td_proc->p_fd, uap->filedes, &fp);
867 if (error == 0) {
868 vfslocked = VFS_LOCK_GIANT(fp->f_vnode->v_mount);
869 error = vacl_get_acl(td, fp->f_vnode, uap->type, uap->aclp);
870 fdrop(fp, td);
871 VFS_UNLOCK_GIANT(vfslocked);
872 }
873 return (error);
874 }
875
876 /*
877 * Given a file descriptor, set an ACL for it
878 *
879 * MPSAFE
880 */
881 int
882 __acl_set_fd(struct thread *td, struct __acl_set_fd_args *uap)
883 {
884 struct file *fp;
885 int vfslocked, error;
886
887 error = getvnode(td->td_proc->p_fd, uap->filedes, &fp);
888 if (error == 0) {
889 vfslocked = VFS_LOCK_GIANT(fp->f_vnode->v_mount);
890 error = vacl_set_acl(td, fp->f_vnode, uap->type, uap->aclp);
891 fdrop(fp, td);
892 VFS_UNLOCK_GIANT(vfslocked);
893 }
894 return (error);
895 }
896
897 /*
898 * Given a file path, delete an ACL from it.
899 *
900 * MPSAFE
901 */
902 int
903 __acl_delete_file(struct thread *td, struct __acl_delete_file_args *uap)
904 {
905 struct nameidata nd;
906 int vfslocked, error;
907
908 NDINIT(&nd, LOOKUP, MPSAFE|FOLLOW, UIO_USERSPACE, uap->path, td);
909 error = namei(&nd);
910 vfslocked = NDHASGIANT(&nd);
911 if (error == 0) {
912 error = vacl_delete(td, nd.ni_vp, uap->type);
913 NDFREE(&nd, 0);
914 }
915 VFS_UNLOCK_GIANT(vfslocked);
916 return (error);
917 }
918
919 /*
920 * Given a file path, delete an ACL from it; don't follow links.
921 *
922 * MPSAFE
923 */
924 int
925 __acl_delete_link(struct thread *td, struct __acl_delete_link_args *uap)
926 {
927 struct nameidata nd;
928 int vfslocked, error;
929
930 NDINIT(&nd, LOOKUP, MPSAFE|NOFOLLOW, UIO_USERSPACE, uap->path, td);
931 error = namei(&nd);
932 vfslocked = NDHASGIANT(&nd);
933 if (error == 0) {
934 error = vacl_delete(td, nd.ni_vp, uap->type);
935 NDFREE(&nd, 0);
936 }
937 VFS_UNLOCK_GIANT(vfslocked);
938 return (error);
939 }
940
941 /*
942 * Given a file path, delete an ACL from it.
943 *
944 * MPSAFE
945 */
946 int
947 __acl_delete_fd(struct thread *td, struct __acl_delete_fd_args *uap)
948 {
949 struct file *fp;
950 int vfslocked, error;
951
952 error = getvnode(td->td_proc->p_fd, uap->filedes, &fp);
953 if (error == 0) {
954 vfslocked = VFS_LOCK_GIANT(fp->f_vnode->v_mount);
955 error = vacl_delete(td, fp->f_vnode, uap->type);
956 fdrop(fp, td);
957 VFS_UNLOCK_GIANT(vfslocked);
958 }
959 return (error);
960 }
961
962 /*
963 * Given a file path, check an ACL for it
964 *
965 * MPSAFE
966 */
967 int
968 __acl_aclcheck_file(struct thread *td, struct __acl_aclcheck_file_args *uap)
969 {
970 struct nameidata nd;
971 int vfslocked, error;
972
973 NDINIT(&nd, LOOKUP, MPSAFE|FOLLOW, UIO_USERSPACE, uap->path, td);
974 error = namei(&nd);
975 vfslocked = NDHASGIANT(&nd);
976 if (error == 0) {
977 error = vacl_aclcheck(td, nd.ni_vp, uap->type, uap->aclp);
978 NDFREE(&nd, 0);
979 }
980 VFS_UNLOCK_GIANT(vfslocked);
981 return (error);
982 }
983
984 /*
985 * Given a file path, check an ACL for it; don't follow links.
986 *
987 * MPSAFE
988 */
989 int
990 __acl_aclcheck_link(struct thread *td, struct __acl_aclcheck_link_args *uap)
991 {
992 struct nameidata nd;
993 int vfslocked, error;
994
995 NDINIT(&nd, LOOKUP, MPSAFE|NOFOLLOW, UIO_USERSPACE, uap->path, td);
996 error = namei(&nd);
997 vfslocked = NDHASGIANT(&nd);
998 if (error == 0) {
999 error = vacl_aclcheck(td, nd.ni_vp, uap->type, uap->aclp);
1000 NDFREE(&nd, 0);
1001 }
1002 VFS_UNLOCK_GIANT(vfslocked);
1003 return (error);
1004 }
1005
1006 /*
1007 * Given a file descriptor, check an ACL for it
1008 *
1009 * MPSAFE
1010 */
1011 int
1012 __acl_aclcheck_fd(struct thread *td, struct __acl_aclcheck_fd_args *uap)
1013 {
1014 struct file *fp;
1015 int vfslocked, error;
1016
1017 error = getvnode(td->td_proc->p_fd, uap->filedes, &fp);
1018 if (error == 0) {
1019 vfslocked = VFS_LOCK_GIANT(fp->f_vnode->v_mount);
1020 error = vacl_aclcheck(td, fp->f_vnode, uap->type, uap->aclp);
1021 fdrop(fp, td);
1022 VFS_UNLOCK_GIANT(vfslocked);
1023 }
1024 return (error);
1025 }
1026
1027 /* ARGUSED */
1028
1029 static void
1030 aclinit(void *dummy __unused)
1031 {
1032
1033 acl_zone = uma_zcreate("ACL UMA zone", sizeof(struct acl),
1034 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
1035 }
1036 SYSINIT(acls, SI_SUB_ACL, SI_ORDER_FIRST, aclinit, NULL)
Cache object: 3eec3df3e915ec3a75924854c646abc1
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