xref: /titanic_41/usr/src/uts/common/fs/zfs/dsl_deleg.c (revision fc0105de770cee6a3fd91de949b9927fba6e894b)
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 2008 Sun Microsystems, Inc.  All rights reserved.
23  * Use is subject to license terms.
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 #pragma ident	"%Z%%M%	%I%	%E% SMI"
70 
71 #include <sys/dmu.h>
72 #include <sys/dmu_objset.h>
73 #include <sys/dmu_tx.h>
74 #include <sys/dsl_dataset.h>
75 #include <sys/dsl_dir.h>
76 #include <sys/dsl_prop.h>
77 #include <sys/dsl_synctask.h>
78 #include <sys/dsl_deleg.h>
79 #include <sys/spa.h>
80 #include <sys/spa_impl.h>
81 #include <sys/zio_checksum.h> /* for the default checksum value */
82 #include <sys/zap.h>
83 #include <sys/fs/zfs.h>
84 #include <sys/cred.h>
85 #include <sys/sunddi.h>
86 
87 #include "zfs_deleg.h"
88 
89 /*
90  * Validate that user is allowed to delegate specified permissions.
91  *
92  * In order to delegate "create" you must have "create"
93  * and "allow".
94  */
95 int
96 dsl_deleg_can_allow(char *ddname, nvlist_t *nvp, cred_t *cr)
97 {
98 	nvpair_t *whopair = NULL;
99 	int error;
100 
101 	if ((error = dsl_deleg_access(ddname, ZFS_DELEG_PERM_ALLOW, cr)) != 0)
102 		return (error);
103 
104 	while (whopair = nvlist_next_nvpair(nvp, whopair)) {
105 		nvlist_t *perms;
106 		nvpair_t *permpair = NULL;
107 
108 		VERIFY(nvpair_value_nvlist(whopair, &perms) == 0);
109 
110 		while (permpair = nvlist_next_nvpair(perms, permpair)) {
111 			const char *perm = nvpair_name(permpair);
112 
113 			if (strcmp(perm, ZFS_DELEG_PERM_ALLOW) == 0)
114 				return (EPERM);
115 
116 			if ((error = dsl_deleg_access(ddname, perm, cr)) != 0)
117 				return (error);
118 		}
119 	}
120 	return (0);
121 }
122 
123 /*
124  * Validate that user is allowed to unallow specified permissions.  They
125  * must have the 'allow' permission, and even then can only unallow
126  * perms for their uid.
127  */
128 int
129 dsl_deleg_can_unallow(char *ddname, nvlist_t *nvp, cred_t *cr)
130 {
131 	nvpair_t *whopair = NULL;
132 	int error;
133 	char idstr[32];
134 
135 	if ((error = dsl_deleg_access(ddname, ZFS_DELEG_PERM_ALLOW, cr)) != 0)
136 		return (error);
137 
138 	(void) snprintf(idstr, sizeof (idstr), "%lld",
139 	    (longlong_t)crgetuid(cr));
140 
141 	while (whopair = nvlist_next_nvpair(nvp, whopair)) {
142 		zfs_deleg_who_type_t type = nvpair_name(whopair)[0];
143 
144 		if (type != ZFS_DELEG_USER &&
145 		    type != ZFS_DELEG_USER_SETS)
146 			return (EPERM);
147 
148 		if (strcmp(idstr, &nvpair_name(whopair)[3]) != 0)
149 			return (EPERM);
150 	}
151 	return (0);
152 }
153 
154 static void
155 dsl_deleg_set_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
156 {
157 	dsl_dir_t *dd = arg1;
158 	nvlist_t *nvp = arg2;
159 	objset_t *mos = dd->dd_pool->dp_meta_objset;
160 	nvpair_t *whopair = NULL;
161 	uint64_t zapobj = dd->dd_phys->dd_deleg_zapobj;
162 
163 	if (zapobj == 0) {
164 		dmu_buf_will_dirty(dd->dd_dbuf, tx);
165 		zapobj = dd->dd_phys->dd_deleg_zapobj = zap_create(mos,
166 		    DMU_OT_DSL_PERMS, DMU_OT_NONE, 0, tx);
167 	}
168 
169 	while (whopair = nvlist_next_nvpair(nvp, whopair)) {
170 		const char *whokey = nvpair_name(whopair);
171 		nvlist_t *perms;
172 		nvpair_t *permpair = NULL;
173 		uint64_t jumpobj;
174 
175 		VERIFY(nvpair_value_nvlist(whopair, &perms) == 0);
176 
177 		if (zap_lookup(mos, zapobj, whokey, 8, 1, &jumpobj) != 0) {
178 			jumpobj = zap_create(mos, DMU_OT_DSL_PERMS,
179 			    DMU_OT_NONE, 0, tx);
180 			VERIFY(zap_update(mos, zapobj,
181 			    whokey, 8, 1, &jumpobj, tx) == 0);
182 		}
183 
184 		while (permpair = nvlist_next_nvpair(perms, permpair)) {
185 			const char *perm = nvpair_name(permpair);
186 			uint64_t n = 0;
187 
188 			VERIFY(zap_update(mos, jumpobj,
189 			    perm, 8, 1, &n, tx) == 0);
190 			spa_history_internal_log(LOG_DS_PERM_UPDATE,
191 			    dd->dd_pool->dp_spa, tx, cr,
192 			    "%s %s dataset = %llu", whokey, perm,
193 			    dd->dd_phys->dd_head_dataset_obj);
194 		}
195 	}
196 }
197 
198 static void
199 dsl_deleg_unset_sync(void *arg1, void *arg2, cred_t *cr, dmu_tx_t *tx)
200 {
201 	dsl_dir_t *dd = arg1;
202 	nvlist_t *nvp = arg2;
203 	objset_t *mos = dd->dd_pool->dp_meta_objset;
204 	nvpair_t *whopair = NULL;
205 	uint64_t zapobj = dd->dd_phys->dd_deleg_zapobj;
206 
207 	if (zapobj == 0)
208 		return;
209 
210 	while (whopair = nvlist_next_nvpair(nvp, whopair)) {
211 		const char *whokey = nvpair_name(whopair);
212 		nvlist_t *perms;
213 		nvpair_t *permpair = NULL;
214 		uint64_t jumpobj;
215 
216 		if (nvpair_value_nvlist(whopair, &perms) != 0) {
217 			if (zap_lookup(mos, zapobj, whokey, 8,
218 			    1, &jumpobj) == 0) {
219 				(void) zap_remove(mos, zapobj, whokey, tx);
220 				VERIFY(0 == zap_destroy(mos, jumpobj, tx));
221 			}
222 			spa_history_internal_log(LOG_DS_PERM_WHO_REMOVE,
223 			    dd->dd_pool->dp_spa, tx, cr,
224 			    "%s dataset = %llu", whokey,
225 			    dd->dd_phys->dd_head_dataset_obj);
226 			continue;
227 		}
228 
229 		if (zap_lookup(mos, zapobj, whokey, 8, 1, &jumpobj) != 0)
230 			continue;
231 
232 		while (permpair = nvlist_next_nvpair(perms, permpair)) {
233 			const char *perm = nvpair_name(permpair);
234 			uint64_t n = 0;
235 
236 			(void) zap_remove(mos, jumpobj, perm, tx);
237 			if (zap_count(mos, jumpobj, &n) == 0 && n == 0) {
238 				(void) zap_remove(mos, zapobj,
239 				    whokey, tx);
240 				VERIFY(0 == zap_destroy(mos,
241 				    jumpobj, tx));
242 			}
243 			spa_history_internal_log(LOG_DS_PERM_REMOVE,
244 			    dd->dd_pool->dp_spa, tx, cr,
245 			    "%s %s dataset = %llu", whokey, perm,
246 			    dd->dd_phys->dd_head_dataset_obj);
247 		}
248 	}
249 }
250 
251 int
252 dsl_deleg_set(const char *ddname, nvlist_t *nvp, boolean_t unset)
253 {
254 	dsl_dir_t *dd;
255 	int error;
256 	nvpair_t *whopair = NULL;
257 	int blocks_modified = 0;
258 
259 	error = dsl_dir_open(ddname, FTAG, &dd, NULL);
260 	if (error)
261 		return (error);
262 
263 	if (spa_version(dmu_objset_spa(dd->dd_pool->dp_meta_objset)) <
264 	    SPA_VERSION_DELEGATED_PERMS) {
265 		dsl_dir_close(dd, FTAG);
266 		return (ENOTSUP);
267 	}
268 
269 	while (whopair = nvlist_next_nvpair(nvp, whopair))
270 		blocks_modified++;
271 
272 	error = dsl_sync_task_do(dd->dd_pool, NULL,
273 	    unset ? dsl_deleg_unset_sync : dsl_deleg_set_sync,
274 	    dd, nvp, blocks_modified);
275 	dsl_dir_close(dd, FTAG);
276 
277 	return (error);
278 }
279 
280 /*
281  * Find all 'allow' permissions from a given point and then continue
282  * traversing up to the root.
283  *
284  * This function constructs an nvlist of nvlists.
285  * each setpoint is an nvlist composed of an nvlist of an nvlist
286  * of the individual * users/groups/everyone/create
287  * permissions.
288  *
289  * The nvlist will look like this.
290  *
291  * { source fsname -> { whokeys { permissions,...}, ...}}
292  *
293  * The fsname nvpairs will be arranged in a bottom up order.  For example,
294  * if we have the following structure a/b/c then the nvpairs for the fsnames
295  * will be ordered a/b/c, a/b, a.
296  */
297 int
298 dsl_deleg_get(const char *ddname, nvlist_t **nvp)
299 {
300 	dsl_dir_t *dd, *startdd;
301 	dsl_pool_t *dp;
302 	int error;
303 	objset_t *mos;
304 
305 	error = dsl_dir_open(ddname, FTAG, &startdd, NULL);
306 	if (error)
307 		return (error);
308 
309 	dp = startdd->dd_pool;
310 	mos = dp->dp_meta_objset;
311 
312 	VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
313 
314 	rw_enter(&dp->dp_config_rwlock, RW_READER);
315 	for (dd = startdd; dd != NULL; dd = dd->dd_parent) {
316 		zap_cursor_t basezc;
317 		zap_attribute_t baseza;
318 		nvlist_t *sp_nvp;
319 		uint64_t n;
320 		char source[MAXNAMELEN];
321 
322 		if (dd->dd_phys->dd_deleg_zapobj &&
323 		    (zap_count(mos, dd->dd_phys->dd_deleg_zapobj,
324 		    &n) == 0) && n) {
325 			VERIFY(nvlist_alloc(&sp_nvp,
326 			    NV_UNIQUE_NAME, KM_SLEEP) == 0);
327 		} else {
328 			continue;
329 		}
330 
331 		for (zap_cursor_init(&basezc, mos,
332 		    dd->dd_phys->dd_deleg_zapobj);
333 		    zap_cursor_retrieve(&basezc, &baseza) == 0;
334 		    zap_cursor_advance(&basezc)) {
335 			zap_cursor_t zc;
336 			zap_attribute_t za;
337 			nvlist_t *perms_nvp;
338 
339 			ASSERT(baseza.za_integer_length == 8);
340 			ASSERT(baseza.za_num_integers == 1);
341 
342 			VERIFY(nvlist_alloc(&perms_nvp,
343 			    NV_UNIQUE_NAME, KM_SLEEP) == 0);
344 			for (zap_cursor_init(&zc, mos, baseza.za_first_integer);
345 			    zap_cursor_retrieve(&zc, &za) == 0;
346 			    zap_cursor_advance(&zc)) {
347 				VERIFY(nvlist_add_boolean(perms_nvp,
348 				    za.za_name) == 0);
349 			}
350 			zap_cursor_fini(&zc);
351 			VERIFY(nvlist_add_nvlist(sp_nvp, baseza.za_name,
352 			    perms_nvp) == 0);
353 			nvlist_free(perms_nvp);
354 		}
355 
356 		zap_cursor_fini(&basezc);
357 
358 		dsl_dir_name(dd, source);
359 		VERIFY(nvlist_add_nvlist(*nvp, source, sp_nvp) == 0);
360 		nvlist_free(sp_nvp);
361 	}
362 	rw_exit(&dp->dp_config_rwlock);
363 
364 	dsl_dir_close(startdd, FTAG);
365 	return (0);
366 }
367 
368 /*
369  * Routines for dsl_deleg_access() -- access checking.
370  */
371 typedef struct perm_set {
372 	avl_node_t	p_node;
373 	boolean_t	p_matched;
374 	char		p_setname[ZFS_MAX_DELEG_NAME];
375 } perm_set_t;
376 
377 static int
378 perm_set_compare(const void *arg1, const void *arg2)
379 {
380 	const perm_set_t *node1 = arg1;
381 	const perm_set_t *node2 = arg2;
382 	int val;
383 
384 	val = strcmp(node1->p_setname, node2->p_setname);
385 	if (val == 0)
386 		return (0);
387 	return (val > 0 ? 1 : -1);
388 }
389 
390 /*
391  * Determine whether a specified permission exists.
392  *
393  * First the base attribute has to be retrieved.  i.e. ul$12
394  * Once the base object has been retrieved the actual permission
395  * is lookup up in the zap object the base object points to.
396  *
397  * Return 0 if permission exists, ENOENT if there is no whokey, EPERM if
398  * there is no perm in that jumpobj.
399  */
400 static int
401 dsl_check_access(objset_t *mos, uint64_t zapobj,
402     char type, char checkflag, void *valp, const char *perm)
403 {
404 	int error;
405 	uint64_t jumpobj, zero;
406 	char whokey[ZFS_MAX_DELEG_NAME];
407 
408 	zfs_deleg_whokey(whokey, type, checkflag, valp);
409 	error = zap_lookup(mos, zapobj, whokey, 8, 1, &jumpobj);
410 	if (error == 0) {
411 		error = zap_lookup(mos, jumpobj, perm, 8, 1, &zero);
412 		if (error == ENOENT)
413 			error = EPERM;
414 	}
415 	return (error);
416 }
417 
418 /*
419  * check a specified user/group for a requested permission
420  */
421 static int
422 dsl_check_user_access(objset_t *mos, uint64_t zapobj, const char *perm,
423     int checkflag, cred_t *cr)
424 {
425 	const	gid_t *gids;
426 	int	ngids;
427 	int	i;
428 	uint64_t id;
429 
430 	/* check for user */
431 	id = crgetuid(cr);
432 	if (dsl_check_access(mos, zapobj,
433 	    ZFS_DELEG_USER, checkflag, &id, perm) == 0)
434 		return (0);
435 
436 	/* check for users primary group */
437 	id = crgetgid(cr);
438 	if (dsl_check_access(mos, zapobj,
439 	    ZFS_DELEG_GROUP, checkflag, &id, perm) == 0)
440 		return (0);
441 
442 	/* check for everyone entry */
443 	id = -1;
444 	if (dsl_check_access(mos, zapobj,
445 	    ZFS_DELEG_EVERYONE, checkflag, &id, perm) == 0)
446 		return (0);
447 
448 	/* check each supplemental group user is a member of */
449 	ngids = crgetngroups(cr);
450 	gids = crgetgroups(cr);
451 	for (i = 0; i != ngids; i++) {
452 		id = gids[i];
453 		if (dsl_check_access(mos, zapobj,
454 		    ZFS_DELEG_GROUP, checkflag, &id, perm) == 0)
455 			return (0);
456 	}
457 
458 	return (EPERM);
459 }
460 
461 /*
462  * Iterate over the sets specified in the specified zapobj
463  * and load them into the permsets avl tree.
464  */
465 static int
466 dsl_load_sets(objset_t *mos, uint64_t zapobj,
467     char type, char checkflag, void *valp, avl_tree_t *avl)
468 {
469 	zap_cursor_t zc;
470 	zap_attribute_t za;
471 	perm_set_t *permnode;
472 	avl_index_t idx;
473 	uint64_t jumpobj;
474 	int error;
475 	char whokey[ZFS_MAX_DELEG_NAME];
476 
477 	zfs_deleg_whokey(whokey, type, checkflag, valp);
478 
479 	error = zap_lookup(mos, zapobj, whokey, 8, 1, &jumpobj);
480 	if (error != 0)
481 		return (error);
482 
483 	for (zap_cursor_init(&zc, mos, jumpobj);
484 	    zap_cursor_retrieve(&zc, &za) == 0;
485 	    zap_cursor_advance(&zc)) {
486 		permnode = kmem_alloc(sizeof (perm_set_t), KM_SLEEP);
487 		(void) strlcpy(permnode->p_setname, za.za_name,
488 		    sizeof (permnode->p_setname));
489 		permnode->p_matched = B_FALSE;
490 
491 		if (avl_find(avl, permnode, &idx) == NULL) {
492 			avl_insert(avl, permnode, idx);
493 		} else {
494 			kmem_free(permnode, sizeof (perm_set_t));
495 		}
496 	}
497 	zap_cursor_fini(&zc);
498 	return (0);
499 }
500 
501 /*
502  * Load all permissions user based on cred belongs to.
503  */
504 static void
505 dsl_load_user_sets(objset_t *mos, uint64_t zapobj, avl_tree_t *avl,
506     char checkflag, cred_t *cr)
507 {
508 	const	gid_t *gids;
509 	int	ngids, i;
510 	uint64_t id;
511 
512 	id = crgetuid(cr);
513 	(void) dsl_load_sets(mos, zapobj,
514 	    ZFS_DELEG_USER_SETS, checkflag, &id, avl);
515 
516 	id = crgetgid(cr);
517 	(void) dsl_load_sets(mos, zapobj,
518 	    ZFS_DELEG_GROUP_SETS, checkflag, &id, avl);
519 
520 	(void) dsl_load_sets(mos, zapobj,
521 	    ZFS_DELEG_EVERYONE_SETS, checkflag, NULL, avl);
522 
523 	ngids = crgetngroups(cr);
524 	gids = crgetgroups(cr);
525 	for (i = 0; i != ngids; i++) {
526 		id = gids[i];
527 		(void) dsl_load_sets(mos, zapobj,
528 		    ZFS_DELEG_GROUP_SETS, checkflag, &id, avl);
529 	}
530 }
531 
532 /*
533  * Check if user has requested permission.
534  */
535 int
536 dsl_deleg_access(const char *dsname, const char *perm, cred_t *cr)
537 {
538 	dsl_dataset_t *ds;
539 	dsl_dir_t *dd;
540 	dsl_pool_t *dp;
541 	void *cookie;
542 	int	error;
543 	char	checkflag = ZFS_DELEG_LOCAL;
544 	objset_t *mos;
545 	avl_tree_t permsets;
546 	perm_set_t *setnode;
547 
548 	error = dsl_dataset_hold(dsname, FTAG, &ds);
549 	if (error)
550 		return (error);
551 
552 	dp = ds->ds_dir->dd_pool;
553 	mos = dp->dp_meta_objset;
554 
555 	if (dsl_delegation_on(mos) == B_FALSE) {
556 		dsl_dataset_rele(ds, FTAG);
557 		return (ECANCELED);
558 	}
559 
560 	if (spa_version(dmu_objset_spa(dp->dp_meta_objset)) <
561 	    SPA_VERSION_DELEGATED_PERMS) {
562 		dsl_dataset_rele(ds, FTAG);
563 		return (EPERM);
564 	}
565 
566 	avl_create(&permsets, perm_set_compare, sizeof (perm_set_t),
567 	    offsetof(perm_set_t, p_node));
568 
569 	rw_enter(&dp->dp_config_rwlock, RW_READER);
570 	for (dd = ds->ds_dir; dd != NULL; dd = dd->dd_parent,
571 	    checkflag = ZFS_DELEG_DESCENDENT) {
572 		uint64_t zapobj;
573 		boolean_t expanded;
574 
575 		/*
576 		 * If not in global zone then make sure
577 		 * the zoned property is set
578 		 */
579 		if (!INGLOBALZONE(curproc)) {
580 			uint64_t zoned;
581 
582 			if (dsl_prop_get_dd(dd,
583 			    zfs_prop_to_name(ZFS_PROP_ZONED),
584 			    8, 1, &zoned, NULL) != 0)
585 				break;
586 			if (!zoned)
587 				break;
588 		}
589 		zapobj = dd->dd_phys->dd_deleg_zapobj;
590 
591 		if (zapobj == 0)
592 			continue;
593 
594 		dsl_load_user_sets(mos, zapobj, &permsets, checkflag, cr);
595 again:
596 		expanded = B_FALSE;
597 		for (setnode = avl_first(&permsets); setnode;
598 		    setnode = AVL_NEXT(&permsets, setnode)) {
599 			if (setnode->p_matched == B_TRUE)
600 				continue;
601 
602 			/* See if this set directly grants this permission */
603 			error = dsl_check_access(mos, zapobj,
604 			    ZFS_DELEG_NAMED_SET, 0, setnode->p_setname, perm);
605 			if (error == 0)
606 				goto success;
607 			if (error == EPERM)
608 				setnode->p_matched = B_TRUE;
609 
610 			/* See if this set includes other sets */
611 			error = dsl_load_sets(mos, zapobj,
612 			    ZFS_DELEG_NAMED_SET_SETS, 0,
613 			    setnode->p_setname, &permsets);
614 			if (error == 0)
615 				setnode->p_matched = expanded = B_TRUE;
616 		}
617 		/*
618 		 * If we expanded any sets, that will define more sets,
619 		 * which we need to check.
620 		 */
621 		if (expanded)
622 			goto again;
623 
624 		error = dsl_check_user_access(mos, zapobj, perm, checkflag, cr);
625 		if (error == 0)
626 			goto success;
627 	}
628 	error = EPERM;
629 success:
630 	rw_exit(&dp->dp_config_rwlock);
631 	dsl_dataset_rele(ds, FTAG);
632 
633 	cookie = NULL;
634 	while ((setnode = avl_destroy_nodes(&permsets, &cookie)) != NULL)
635 		kmem_free(setnode, sizeof (perm_set_t));
636 
637 	return (error);
638 }
639 
640 /*
641  * Other routines.
642  */
643 
644 static void
645 copy_create_perms(dsl_dir_t *dd, uint64_t pzapobj,
646     boolean_t dosets, uint64_t uid, dmu_tx_t *tx)
647 {
648 	objset_t *mos = dd->dd_pool->dp_meta_objset;
649 	uint64_t jumpobj, pjumpobj;
650 	uint64_t zapobj = dd->dd_phys->dd_deleg_zapobj;
651 	zap_cursor_t zc;
652 	zap_attribute_t za;
653 	char whokey[ZFS_MAX_DELEG_NAME];
654 
655 	zfs_deleg_whokey(whokey,
656 	    dosets ? ZFS_DELEG_CREATE_SETS : ZFS_DELEG_CREATE,
657 	    ZFS_DELEG_LOCAL, NULL);
658 	if (zap_lookup(mos, pzapobj, whokey, 8, 1, &pjumpobj) != 0)
659 		return;
660 
661 	if (zapobj == 0) {
662 		dmu_buf_will_dirty(dd->dd_dbuf, tx);
663 		zapobj = dd->dd_phys->dd_deleg_zapobj = zap_create(mos,
664 		    DMU_OT_DSL_PERMS, DMU_OT_NONE, 0, tx);
665 	}
666 
667 	zfs_deleg_whokey(whokey,
668 	    dosets ? ZFS_DELEG_USER_SETS : ZFS_DELEG_USER,
669 	    ZFS_DELEG_LOCAL, &uid);
670 	if (zap_lookup(mos, zapobj, whokey, 8, 1, &jumpobj) == ENOENT) {
671 		jumpobj = zap_create(mos, DMU_OT_DSL_PERMS, DMU_OT_NONE, 0, tx);
672 		VERIFY(zap_add(mos, zapobj, whokey, 8, 1, &jumpobj, tx) == 0);
673 	}
674 
675 	for (zap_cursor_init(&zc, mos, pjumpobj);
676 	    zap_cursor_retrieve(&zc, &za) == 0;
677 	    zap_cursor_advance(&zc)) {
678 		uint64_t zero = 0;
679 		ASSERT(za.za_integer_length == 8 && za.za_num_integers == 1);
680 
681 		VERIFY(zap_update(mos, jumpobj, za.za_name,
682 		    8, 1, &zero, tx) == 0);
683 	}
684 	zap_cursor_fini(&zc);
685 }
686 
687 /*
688  * set all create time permission on new dataset.
689  */
690 void
691 dsl_deleg_set_create_perms(dsl_dir_t *sdd, dmu_tx_t *tx, cred_t *cr)
692 {
693 	dsl_dir_t *dd;
694 	uint64_t uid = crgetuid(cr);
695 
696 	if (spa_version(dmu_objset_spa(sdd->dd_pool->dp_meta_objset)) <
697 	    SPA_VERSION_DELEGATED_PERMS)
698 		return;
699 
700 	for (dd = sdd->dd_parent; dd != NULL; dd = dd->dd_parent) {
701 		uint64_t pzapobj = dd->dd_phys->dd_deleg_zapobj;
702 
703 		if (pzapobj == 0)
704 			continue;
705 
706 		copy_create_perms(sdd, pzapobj, B_FALSE, uid, tx);
707 		copy_create_perms(sdd, pzapobj, B_TRUE, uid, tx);
708 	}
709 }
710 
711 int
712 dsl_deleg_destroy(objset_t *mos, uint64_t zapobj, dmu_tx_t *tx)
713 {
714 	zap_cursor_t zc;
715 	zap_attribute_t za;
716 
717 	if (zapobj == 0)
718 		return (0);
719 
720 	for (zap_cursor_init(&zc, mos, zapobj);
721 	    zap_cursor_retrieve(&zc, &za) == 0;
722 	    zap_cursor_advance(&zc)) {
723 		ASSERT(za.za_integer_length == 8 && za.za_num_integers == 1);
724 		VERIFY(0 == zap_destroy(mos, za.za_first_integer, tx));
725 	}
726 	zap_cursor_fini(&zc);
727 	VERIFY(0 == zap_destroy(mos, zapobj, tx));
728 	return (0);
729 }
730 
731 boolean_t
732 dsl_delegation_on(objset_t *os)
733 {
734 	return (os->os->os_spa->spa_delegation);
735 }
736