xref: /titanic_50/usr/src/uts/common/fs/zfs/dsl_deleg.c (revision 33c41f2b7f5e60517664bd7f392221865f833526)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 /*
22  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
23  * Copyright (c) 2012 by Delphix. All rights reserved.
24  */
25 
26 /*
27  * DSL permissions are stored in a two level zap attribute
28  * mechanism.   The first level identifies the "class" of
29  * entry.  The class is identified by the first 2 letters of
30  * the attribute.  The second letter "l" or "d" identifies whether
31  * it is a local or descendent permission.  The first letter
32  * identifies the type of entry.
33  *
34  * ul$<id>    identifies permissions granted locally for this userid.
35  * ud$<id>    identifies permissions granted on descendent datasets for
36  *            this userid.
37  * Ul$<id>    identifies permission sets granted locally for this userid.
38  * Ud$<id>    identifies permission sets granted on descendent datasets for
39  *            this userid.
40  * gl$<id>    identifies permissions granted locally for this groupid.
41  * gd$<id>    identifies permissions granted on descendent datasets for
42  *            this groupid.
43  * Gl$<id>    identifies permission sets granted locally for this groupid.
44  * Gd$<id>    identifies permission sets granted on descendent datasets for
45  *            this groupid.
46  * el$        identifies permissions granted locally for everyone.
47  * ed$        identifies permissions granted on descendent datasets
48  *            for everyone.
49  * El$        identifies permission sets granted locally for everyone.
50  * Ed$        identifies permission sets granted to descendent datasets for
51  *            everyone.
52  * c-$        identifies permission to create at dataset creation time.
53  * C-$        identifies permission sets to grant locally at dataset creation
54  *            time.
55  * s-$@<name> permissions defined in specified set @<name>
56  * S-$@<name> Sets defined in named set @<name>
57  *
58  * Each of the above entities points to another zap attribute that contains one
59  * attribute for each allowed permission, such as create, destroy,...
60  * All of the "upper" case class types will specify permission set names
61  * rather than permissions.
62  *
63  * Basically it looks something like this:
64  * ul$12 -> ZAP OBJ -> permissions...
65  *
66  * The ZAP OBJ is referred to as the jump object.
67  */
68 
69 #include <sys/dmu.h>
70 #include <sys/dmu_objset.h>
71 #include <sys/dmu_tx.h>
72 #include <sys/dsl_dataset.h>
73 #include <sys/dsl_dir.h>
74 #include <sys/dsl_prop.h>
75 #include <sys/dsl_synctask.h>
76 #include <sys/dsl_deleg.h>
77 #include <sys/spa.h>
78 #include <sys/zap.h>
79 #include <sys/fs/zfs.h>
80 #include <sys/cred.h>
81 #include <sys/sunddi.h>
82 
83 #include "zfs_deleg.h"
84 
85 /*
86  * Validate that user is allowed to delegate specified permissions.
87  *
88  * In order to delegate "create" you must have "create"
89  * and "allow".
90  */
91 int
92 dsl_deleg_can_allow(char *ddname, nvlist_t *nvp, cred_t *cr)
93 {
94 	nvpair_t *whopair = NULL;
95 	int error;
96 
97 	if ((error = dsl_deleg_access(ddname, ZFS_DELEG_PERM_ALLOW, cr)) != 0)
98 		return (error);
99 
100 	while (whopair = nvlist_next_nvpair(nvp, whopair)) {
101 		nvlist_t *perms;
102 		nvpair_t *permpair = NULL;
103 
104 		VERIFY(nvpair_value_nvlist(whopair, &perms) == 0);
105 
106 		while (permpair = nvlist_next_nvpair(perms, permpair)) {
107 			const char *perm = nvpair_name(permpair);
108 
109 			if (strcmp(perm, ZFS_DELEG_PERM_ALLOW) == 0)
110 				return (EPERM);
111 
112 			if ((error = dsl_deleg_access(ddname, perm, cr)) != 0)
113 				return (error);
114 		}
115 	}
116 	return (0);
117 }
118 
119 /*
120  * Validate that user is allowed to unallow specified permissions.  They
121  * must have the 'allow' permission, and even then can only unallow
122  * perms for their uid.
123  */
124 int
125 dsl_deleg_can_unallow(char *ddname, nvlist_t *nvp, cred_t *cr)
126 {
127 	nvpair_t *whopair = NULL;
128 	int error;
129 	char idstr[32];
130 
131 	if ((error = dsl_deleg_access(ddname, ZFS_DELEG_PERM_ALLOW, cr)) != 0)
132 		return (error);
133 
134 	(void) snprintf(idstr, sizeof (idstr), "%lld",
135 	    (longlong_t)crgetuid(cr));
136 
137 	while (whopair = nvlist_next_nvpair(nvp, whopair)) {
138 		zfs_deleg_who_type_t type = nvpair_name(whopair)[0];
139 
140 		if (type != ZFS_DELEG_USER &&
141 		    type != ZFS_DELEG_USER_SETS)
142 			return (EPERM);
143 
144 		if (strcmp(idstr, &nvpair_name(whopair)[3]) != 0)
145 			return (EPERM);
146 	}
147 	return (0);
148 }
149 
150 static void
151 dsl_deleg_set_sync(void *arg1, void *arg2, dmu_tx_t *tx)
152 {
153 	dsl_dir_t *dd = arg1;
154 	nvlist_t *nvp = arg2;
155 	objset_t *mos = dd->dd_pool->dp_meta_objset;
156 	nvpair_t *whopair = NULL;
157 	uint64_t zapobj = dd->dd_phys->dd_deleg_zapobj;
158 
159 	if (zapobj == 0) {
160 		dmu_buf_will_dirty(dd->dd_dbuf, tx);
161 		zapobj = dd->dd_phys->dd_deleg_zapobj = zap_create(mos,
162 		    DMU_OT_DSL_PERMS, DMU_OT_NONE, 0, tx);
163 	}
164 
165 	while (whopair = nvlist_next_nvpair(nvp, whopair)) {
166 		const char *whokey = nvpair_name(whopair);
167 		nvlist_t *perms;
168 		nvpair_t *permpair = NULL;
169 		uint64_t jumpobj;
170 
171 		VERIFY(nvpair_value_nvlist(whopair, &perms) == 0);
172 
173 		if (zap_lookup(mos, zapobj, whokey, 8, 1, &jumpobj) != 0) {
174 			jumpobj = zap_create_link(mos, DMU_OT_DSL_PERMS,
175 			    zapobj, whokey, tx);
176 		}
177 
178 		while (permpair = nvlist_next_nvpair(perms, permpair)) {
179 			const char *perm = nvpair_name(permpair);
180 			uint64_t n = 0;
181 
182 			VERIFY(zap_update(mos, jumpobj,
183 			    perm, 8, 1, &n, tx) == 0);
184 			spa_history_log_internal_dd(dd, "permission update", tx,
185 			    "%s %s", whokey, perm);
186 		}
187 	}
188 }
189 
190 static void
191 dsl_deleg_unset_sync(void *arg1, void *arg2, dmu_tx_t *tx)
192 {
193 	dsl_dir_t *dd = arg1;
194 	nvlist_t *nvp = arg2;
195 	objset_t *mos = dd->dd_pool->dp_meta_objset;
196 	nvpair_t *whopair = NULL;
197 	uint64_t zapobj = dd->dd_phys->dd_deleg_zapobj;
198 
199 	if (zapobj == 0)
200 		return;
201 
202 	while (whopair = nvlist_next_nvpair(nvp, whopair)) {
203 		const char *whokey = nvpair_name(whopair);
204 		nvlist_t *perms;
205 		nvpair_t *permpair = NULL;
206 		uint64_t jumpobj;
207 
208 		if (nvpair_value_nvlist(whopair, &perms) != 0) {
209 			if (zap_lookup(mos, zapobj, whokey, 8,
210 			    1, &jumpobj) == 0) {
211 				(void) zap_remove(mos, zapobj, whokey, tx);
212 				VERIFY(0 == zap_destroy(mos, jumpobj, tx));
213 			}
214 			spa_history_log_internal_dd(dd, "permission who remove",
215 			    tx, "%s", whokey);
216 			continue;
217 		}
218 
219 		if (zap_lookup(mos, zapobj, whokey, 8, 1, &jumpobj) != 0)
220 			continue;
221 
222 		while (permpair = nvlist_next_nvpair(perms, permpair)) {
223 			const char *perm = nvpair_name(permpair);
224 			uint64_t n = 0;
225 
226 			(void) zap_remove(mos, jumpobj, perm, tx);
227 			if (zap_count(mos, jumpobj, &n) == 0 && n == 0) {
228 				(void) zap_remove(mos, zapobj,
229 				    whokey, tx);
230 				VERIFY(0 == zap_destroy(mos,
231 				    jumpobj, tx));
232 			}
233 			spa_history_log_internal_dd(dd, "permission remove", tx,
234 			    "%s %s", whokey, perm);
235 		}
236 	}
237 }
238 
239 int
240 dsl_deleg_set(const char *ddname, nvlist_t *nvp, boolean_t unset)
241 {
242 	dsl_dir_t *dd;
243 	int error;
244 	nvpair_t *whopair = NULL;
245 	int blocks_modified = 0;
246 
247 	error = dsl_dir_open(ddname, FTAG, &dd, NULL);
248 	if (error)
249 		return (error);
250 
251 	if (spa_version(dmu_objset_spa(dd->dd_pool->dp_meta_objset)) <
252 	    SPA_VERSION_DELEGATED_PERMS) {
253 		dsl_dir_close(dd, FTAG);
254 		return (ENOTSUP);
255 	}
256 
257 	while (whopair = nvlist_next_nvpair(nvp, whopair))
258 		blocks_modified++;
259 
260 	error = dsl_sync_task_do(dd->dd_pool, NULL,
261 	    unset ? dsl_deleg_unset_sync : dsl_deleg_set_sync,
262 	    dd, nvp, blocks_modified);
263 	dsl_dir_close(dd, FTAG);
264 
265 	return (error);
266 }
267 
268 /*
269  * Find all 'allow' permissions from a given point and then continue
270  * traversing up to the root.
271  *
272  * This function constructs an nvlist of nvlists.
273  * each setpoint is an nvlist composed of an nvlist of an nvlist
274  * of the individual * users/groups/everyone/create
275  * permissions.
276  *
277  * The nvlist will look like this.
278  *
279  * { source fsname -> { whokeys { permissions,...}, ...}}
280  *
281  * The fsname nvpairs will be arranged in a bottom up order.  For example,
282  * if we have the following structure a/b/c then the nvpairs for the fsnames
283  * will be ordered a/b/c, a/b, a.
284  */
285 int
286 dsl_deleg_get(const char *ddname, nvlist_t **nvp)
287 {
288 	dsl_dir_t *dd, *startdd;
289 	dsl_pool_t *dp;
290 	int error;
291 	objset_t *mos;
292 
293 	error = dsl_dir_open(ddname, FTAG, &startdd, NULL);
294 	if (error)
295 		return (error);
296 
297 	dp = startdd->dd_pool;
298 	mos = dp->dp_meta_objset;
299 
300 	VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
301 
302 	rw_enter(&dp->dp_config_rwlock, RW_READER);
303 	for (dd = startdd; dd != NULL; dd = dd->dd_parent) {
304 		zap_cursor_t basezc;
305 		zap_attribute_t baseza;
306 		nvlist_t *sp_nvp;
307 		uint64_t n;
308 		char source[MAXNAMELEN];
309 
310 		if (dd->dd_phys->dd_deleg_zapobj &&
311 		    (zap_count(mos, dd->dd_phys->dd_deleg_zapobj,
312 		    &n) == 0) && n) {
313 			VERIFY(nvlist_alloc(&sp_nvp,
314 			    NV_UNIQUE_NAME, KM_SLEEP) == 0);
315 		} else {
316 			continue;
317 		}
318 
319 		for (zap_cursor_init(&basezc, mos,
320 		    dd->dd_phys->dd_deleg_zapobj);
321 		    zap_cursor_retrieve(&basezc, &baseza) == 0;
322 		    zap_cursor_advance(&basezc)) {
323 			zap_cursor_t zc;
324 			zap_attribute_t za;
325 			nvlist_t *perms_nvp;
326 
327 			ASSERT(baseza.za_integer_length == 8);
328 			ASSERT(baseza.za_num_integers == 1);
329 
330 			VERIFY(nvlist_alloc(&perms_nvp,
331 			    NV_UNIQUE_NAME, KM_SLEEP) == 0);
332 			for (zap_cursor_init(&zc, mos, baseza.za_first_integer);
333 			    zap_cursor_retrieve(&zc, &za) == 0;
334 			    zap_cursor_advance(&zc)) {
335 				VERIFY(nvlist_add_boolean(perms_nvp,
336 				    za.za_name) == 0);
337 			}
338 			zap_cursor_fini(&zc);
339 			VERIFY(nvlist_add_nvlist(sp_nvp, baseza.za_name,
340 			    perms_nvp) == 0);
341 			nvlist_free(perms_nvp);
342 		}
343 
344 		zap_cursor_fini(&basezc);
345 
346 		dsl_dir_name(dd, source);
347 		VERIFY(nvlist_add_nvlist(*nvp, source, sp_nvp) == 0);
348 		nvlist_free(sp_nvp);
349 	}
350 	rw_exit(&dp->dp_config_rwlock);
351 
352 	dsl_dir_close(startdd, FTAG);
353 	return (0);
354 }
355 
356 /*
357  * Routines for dsl_deleg_access() -- access checking.
358  */
359 typedef struct perm_set {
360 	avl_node_t	p_node;
361 	boolean_t	p_matched;
362 	char		p_setname[ZFS_MAX_DELEG_NAME];
363 } perm_set_t;
364 
365 static int
366 perm_set_compare(const void *arg1, const void *arg2)
367 {
368 	const perm_set_t *node1 = arg1;
369 	const perm_set_t *node2 = arg2;
370 	int val;
371 
372 	val = strcmp(node1->p_setname, node2->p_setname);
373 	if (val == 0)
374 		return (0);
375 	return (val > 0 ? 1 : -1);
376 }
377 
378 /*
379  * Determine whether a specified permission exists.
380  *
381  * First the base attribute has to be retrieved.  i.e. ul$12
382  * Once the base object has been retrieved the actual permission
383  * is lookup up in the zap object the base object points to.
384  *
385  * Return 0 if permission exists, ENOENT if there is no whokey, EPERM if
386  * there is no perm in that jumpobj.
387  */
388 static int
389 dsl_check_access(objset_t *mos, uint64_t zapobj,
390     char type, char checkflag, void *valp, const char *perm)
391 {
392 	int error;
393 	uint64_t jumpobj, zero;
394 	char whokey[ZFS_MAX_DELEG_NAME];
395 
396 	zfs_deleg_whokey(whokey, type, checkflag, valp);
397 	error = zap_lookup(mos, zapobj, whokey, 8, 1, &jumpobj);
398 	if (error == 0) {
399 		error = zap_lookup(mos, jumpobj, perm, 8, 1, &zero);
400 		if (error == ENOENT)
401 			error = EPERM;
402 	}
403 	return (error);
404 }
405 
406 /*
407  * check a specified user/group for a requested permission
408  */
409 static int
410 dsl_check_user_access(objset_t *mos, uint64_t zapobj, const char *perm,
411     int checkflag, cred_t *cr)
412 {
413 	const	gid_t *gids;
414 	int	ngids;
415 	int	i;
416 	uint64_t id;
417 
418 	/* check for user */
419 	id = crgetuid(cr);
420 	if (dsl_check_access(mos, zapobj,
421 	    ZFS_DELEG_USER, checkflag, &id, perm) == 0)
422 		return (0);
423 
424 	/* check for users primary group */
425 	id = crgetgid(cr);
426 	if (dsl_check_access(mos, zapobj,
427 	    ZFS_DELEG_GROUP, checkflag, &id, perm) == 0)
428 		return (0);
429 
430 	/* check for everyone entry */
431 	id = -1;
432 	if (dsl_check_access(mos, zapobj,
433 	    ZFS_DELEG_EVERYONE, checkflag, &id, perm) == 0)
434 		return (0);
435 
436 	/* check each supplemental group user is a member of */
437 	ngids = crgetngroups(cr);
438 	gids = crgetgroups(cr);
439 	for (i = 0; i != ngids; i++) {
440 		id = gids[i];
441 		if (dsl_check_access(mos, zapobj,
442 		    ZFS_DELEG_GROUP, checkflag, &id, perm) == 0)
443 			return (0);
444 	}
445 
446 	return (EPERM);
447 }
448 
449 /*
450  * Iterate over the sets specified in the specified zapobj
451  * and load them into the permsets avl tree.
452  */
453 static int
454 dsl_load_sets(objset_t *mos, uint64_t zapobj,
455     char type, char checkflag, void *valp, avl_tree_t *avl)
456 {
457 	zap_cursor_t zc;
458 	zap_attribute_t za;
459 	perm_set_t *permnode;
460 	avl_index_t idx;
461 	uint64_t jumpobj;
462 	int error;
463 	char whokey[ZFS_MAX_DELEG_NAME];
464 
465 	zfs_deleg_whokey(whokey, type, checkflag, valp);
466 
467 	error = zap_lookup(mos, zapobj, whokey, 8, 1, &jumpobj);
468 	if (error != 0)
469 		return (error);
470 
471 	for (zap_cursor_init(&zc, mos, jumpobj);
472 	    zap_cursor_retrieve(&zc, &za) == 0;
473 	    zap_cursor_advance(&zc)) {
474 		permnode = kmem_alloc(sizeof (perm_set_t), KM_SLEEP);
475 		(void) strlcpy(permnode->p_setname, za.za_name,
476 		    sizeof (permnode->p_setname));
477 		permnode->p_matched = B_FALSE;
478 
479 		if (avl_find(avl, permnode, &idx) == NULL) {
480 			avl_insert(avl, permnode, idx);
481 		} else {
482 			kmem_free(permnode, sizeof (perm_set_t));
483 		}
484 	}
485 	zap_cursor_fini(&zc);
486 	return (0);
487 }
488 
489 /*
490  * Load all permissions user based on cred belongs to.
491  */
492 static void
493 dsl_load_user_sets(objset_t *mos, uint64_t zapobj, avl_tree_t *avl,
494     char checkflag, cred_t *cr)
495 {
496 	const	gid_t *gids;
497 	int	ngids, i;
498 	uint64_t id;
499 
500 	id = crgetuid(cr);
501 	(void) dsl_load_sets(mos, zapobj,
502 	    ZFS_DELEG_USER_SETS, checkflag, &id, avl);
503 
504 	id = crgetgid(cr);
505 	(void) dsl_load_sets(mos, zapobj,
506 	    ZFS_DELEG_GROUP_SETS, checkflag, &id, avl);
507 
508 	(void) dsl_load_sets(mos, zapobj,
509 	    ZFS_DELEG_EVERYONE_SETS, checkflag, NULL, avl);
510 
511 	ngids = crgetngroups(cr);
512 	gids = crgetgroups(cr);
513 	for (i = 0; i != ngids; i++) {
514 		id = gids[i];
515 		(void) dsl_load_sets(mos, zapobj,
516 		    ZFS_DELEG_GROUP_SETS, checkflag, &id, avl);
517 	}
518 }
519 
520 /*
521  * Check if user has requested permission.
522  */
523 int
524 dsl_deleg_access_impl(dsl_dataset_t *ds, const char *perm, cred_t *cr)
525 {
526 	dsl_dir_t *dd;
527 	dsl_pool_t *dp;
528 	void *cookie;
529 	int	error;
530 	char	checkflag;
531 	objset_t *mos;
532 	avl_tree_t permsets;
533 	perm_set_t *setnode;
534 
535 	dp = ds->ds_dir->dd_pool;
536 	mos = dp->dp_meta_objset;
537 
538 	if (dsl_delegation_on(mos) == B_FALSE)
539 		return (ECANCELED);
540 
541 	if (spa_version(dmu_objset_spa(dp->dp_meta_objset)) <
542 	    SPA_VERSION_DELEGATED_PERMS)
543 		return (EPERM);
544 
545 	if (dsl_dataset_is_snapshot(ds)) {
546 		/*
547 		 * Snapshots are treated as descendents only,
548 		 * local permissions do not apply.
549 		 */
550 		checkflag = ZFS_DELEG_DESCENDENT;
551 	} else {
552 		checkflag = ZFS_DELEG_LOCAL;
553 	}
554 
555 	avl_create(&permsets, perm_set_compare, sizeof (perm_set_t),
556 	    offsetof(perm_set_t, p_node));
557 
558 	rw_enter(&dp->dp_config_rwlock, RW_READER);
559 	for (dd = ds->ds_dir; dd != NULL; dd = dd->dd_parent,
560 	    checkflag = ZFS_DELEG_DESCENDENT) {
561 		uint64_t zapobj;
562 		boolean_t expanded;
563 
564 		/*
565 		 * If not in global zone then make sure
566 		 * the zoned property is set
567 		 */
568 		if (!INGLOBALZONE(curproc)) {
569 			uint64_t zoned;
570 
571 			if (dsl_prop_get_dd(dd,
572 			    zfs_prop_to_name(ZFS_PROP_ZONED),
573 			    8, 1, &zoned, NULL, B_FALSE) != 0)
574 				break;
575 			if (!zoned)
576 				break;
577 		}
578 		zapobj = dd->dd_phys->dd_deleg_zapobj;
579 
580 		if (zapobj == 0)
581 			continue;
582 
583 		dsl_load_user_sets(mos, zapobj, &permsets, checkflag, cr);
584 again:
585 		expanded = B_FALSE;
586 		for (setnode = avl_first(&permsets); setnode;
587 		    setnode = AVL_NEXT(&permsets, setnode)) {
588 			if (setnode->p_matched == B_TRUE)
589 				continue;
590 
591 			/* See if this set directly grants this permission */
592 			error = dsl_check_access(mos, zapobj,
593 			    ZFS_DELEG_NAMED_SET, 0, setnode->p_setname, perm);
594 			if (error == 0)
595 				goto success;
596 			if (error == EPERM)
597 				setnode->p_matched = B_TRUE;
598 
599 			/* See if this set includes other sets */
600 			error = dsl_load_sets(mos, zapobj,
601 			    ZFS_DELEG_NAMED_SET_SETS, 0,
602 			    setnode->p_setname, &permsets);
603 			if (error == 0)
604 				setnode->p_matched = expanded = B_TRUE;
605 		}
606 		/*
607 		 * If we expanded any sets, that will define more sets,
608 		 * which we need to check.
609 		 */
610 		if (expanded)
611 			goto again;
612 
613 		error = dsl_check_user_access(mos, zapobj, perm, checkflag, cr);
614 		if (error == 0)
615 			goto success;
616 	}
617 	error = EPERM;
618 success:
619 	rw_exit(&dp->dp_config_rwlock);
620 
621 	cookie = NULL;
622 	while ((setnode = avl_destroy_nodes(&permsets, &cookie)) != NULL)
623 		kmem_free(setnode, sizeof (perm_set_t));
624 
625 	return (error);
626 }
627 
628 int
629 dsl_deleg_access(const char *dsname, const char *perm, cred_t *cr)
630 {
631 	dsl_dataset_t *ds;
632 	int error;
633 
634 	error = dsl_dataset_hold(dsname, FTAG, &ds);
635 	if (error)
636 		return (error);
637 
638 	error = dsl_deleg_access_impl(ds, perm, cr);
639 	dsl_dataset_rele(ds, FTAG);
640 
641 	return (error);
642 }
643 
644 /*
645  * Other routines.
646  */
647 
648 static void
649 copy_create_perms(dsl_dir_t *dd, uint64_t pzapobj,
650     boolean_t dosets, uint64_t uid, dmu_tx_t *tx)
651 {
652 	objset_t *mos = dd->dd_pool->dp_meta_objset;
653 	uint64_t jumpobj, pjumpobj;
654 	uint64_t zapobj = dd->dd_phys->dd_deleg_zapobj;
655 	zap_cursor_t zc;
656 	zap_attribute_t za;
657 	char whokey[ZFS_MAX_DELEG_NAME];
658 
659 	zfs_deleg_whokey(whokey,
660 	    dosets ? ZFS_DELEG_CREATE_SETS : ZFS_DELEG_CREATE,
661 	    ZFS_DELEG_LOCAL, NULL);
662 	if (zap_lookup(mos, pzapobj, whokey, 8, 1, &pjumpobj) != 0)
663 		return;
664 
665 	if (zapobj == 0) {
666 		dmu_buf_will_dirty(dd->dd_dbuf, tx);
667 		zapobj = dd->dd_phys->dd_deleg_zapobj = zap_create(mos,
668 		    DMU_OT_DSL_PERMS, DMU_OT_NONE, 0, tx);
669 	}
670 
671 	zfs_deleg_whokey(whokey,
672 	    dosets ? ZFS_DELEG_USER_SETS : ZFS_DELEG_USER,
673 	    ZFS_DELEG_LOCAL, &uid);
674 	if (zap_lookup(mos, zapobj, whokey, 8, 1, &jumpobj) == ENOENT) {
675 		jumpobj = zap_create(mos, DMU_OT_DSL_PERMS, DMU_OT_NONE, 0, tx);
676 		VERIFY(zap_add(mos, zapobj, whokey, 8, 1, &jumpobj, tx) == 0);
677 	}
678 
679 	for (zap_cursor_init(&zc, mos, pjumpobj);
680 	    zap_cursor_retrieve(&zc, &za) == 0;
681 	    zap_cursor_advance(&zc)) {
682 		uint64_t zero = 0;
683 		ASSERT(za.za_integer_length == 8 && za.za_num_integers == 1);
684 
685 		VERIFY(zap_update(mos, jumpobj, za.za_name,
686 		    8, 1, &zero, tx) == 0);
687 	}
688 	zap_cursor_fini(&zc);
689 }
690 
691 /*
692  * set all create time permission on new dataset.
693  */
694 void
695 dsl_deleg_set_create_perms(dsl_dir_t *sdd, dmu_tx_t *tx, cred_t *cr)
696 {
697 	dsl_dir_t *dd;
698 	uint64_t uid = crgetuid(cr);
699 
700 	if (spa_version(dmu_objset_spa(sdd->dd_pool->dp_meta_objset)) <
701 	    SPA_VERSION_DELEGATED_PERMS)
702 		return;
703 
704 	for (dd = sdd->dd_parent; dd != NULL; dd = dd->dd_parent) {
705 		uint64_t pzapobj = dd->dd_phys->dd_deleg_zapobj;
706 
707 		if (pzapobj == 0)
708 			continue;
709 
710 		copy_create_perms(sdd, pzapobj, B_FALSE, uid, tx);
711 		copy_create_perms(sdd, pzapobj, B_TRUE, uid, tx);
712 	}
713 }
714 
715 int
716 dsl_deleg_destroy(objset_t *mos, uint64_t zapobj, dmu_tx_t *tx)
717 {
718 	zap_cursor_t zc;
719 	zap_attribute_t za;
720 
721 	if (zapobj == 0)
722 		return (0);
723 
724 	for (zap_cursor_init(&zc, mos, zapobj);
725 	    zap_cursor_retrieve(&zc, &za) == 0;
726 	    zap_cursor_advance(&zc)) {
727 		ASSERT(za.za_integer_length == 8 && za.za_num_integers == 1);
728 		VERIFY(0 == zap_destroy(mos, za.za_first_integer, tx));
729 	}
730 	zap_cursor_fini(&zc);
731 	VERIFY(0 == zap_destroy(mos, zapobj, tx));
732 	return (0);
733 }
734 
735 boolean_t
736 dsl_delegation_on(objset_t *os)
737 {
738 	return (!!spa_delegation(os->os_spa));
739 }
740