xref: /freebsd/sys/contrib/openzfs/module/zfs/dsl_deleg.c (revision 7a7741af18d6c8a804cc643cb7ecda9d730c6aa6)
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 https://opensource.org/licenses/CDDL-1.0.
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) 2011, 2015 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
dsl_deleg_can_allow(char * ddname,nvlist_t * nvp,cred_t * cr)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 (SET_ERROR(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
dsl_deleg_can_unallow(char * ddname,nvlist_t * nvp,cred_t * cr)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 (SET_ERROR(EPERM));
143 
144 		if (strcmp(idstr, &nvpair_name(whopair)[3]) != 0)
145 			return (SET_ERROR(EPERM));
146 	}
147 	return (0);
148 }
149 
150 typedef struct dsl_deleg_arg {
151 	const char *dda_name;
152 	nvlist_t *dda_nvlist;
153 } dsl_deleg_arg_t;
154 
155 static void
dsl_deleg_set_sync(void * arg,dmu_tx_t * tx)156 dsl_deleg_set_sync(void *arg, dmu_tx_t *tx)
157 {
158 	dsl_deleg_arg_t *dda = arg;
159 	dsl_dir_t *dd;
160 	dsl_pool_t *dp = dmu_tx_pool(tx);
161 	objset_t *mos = dp->dp_meta_objset;
162 	nvpair_t *whopair = NULL;
163 	uint64_t zapobj;
164 
165 	VERIFY0(dsl_dir_hold(dp, dda->dda_name, FTAG, &dd, NULL));
166 
167 	zapobj = dsl_dir_phys(dd)->dd_deleg_zapobj;
168 	if (zapobj == 0) {
169 		dmu_buf_will_dirty(dd->dd_dbuf, tx);
170 		zapobj = dsl_dir_phys(dd)->dd_deleg_zapobj = zap_create(mos,
171 		    DMU_OT_DSL_PERMS, DMU_OT_NONE, 0, tx);
172 	}
173 
174 	while ((whopair = nvlist_next_nvpair(dda->dda_nvlist, whopair))) {
175 		const char *whokey = nvpair_name(whopair);
176 		nvlist_t *perms;
177 		nvpair_t *permpair = NULL;
178 		uint64_t jumpobj;
179 
180 		perms = fnvpair_value_nvlist(whopair);
181 
182 		if (zap_lookup(mos, zapobj, whokey, 8, 1, &jumpobj) != 0) {
183 			jumpobj = zap_create_link(mos, DMU_OT_DSL_PERMS,
184 			    zapobj, whokey, tx);
185 		}
186 
187 		while ((permpair = nvlist_next_nvpair(perms, permpair))) {
188 			const char *perm = nvpair_name(permpair);
189 			uint64_t n = 0;
190 
191 			VERIFY(zap_update(mos, jumpobj,
192 			    perm, 8, 1, &n, tx) == 0);
193 			spa_history_log_internal_dd(dd, "permission update", tx,
194 			    "%s %s", whokey, perm);
195 		}
196 	}
197 	dsl_dir_rele(dd, FTAG);
198 }
199 
200 static void
dsl_deleg_unset_sync(void * arg,dmu_tx_t * tx)201 dsl_deleg_unset_sync(void *arg, dmu_tx_t *tx)
202 {
203 	dsl_deleg_arg_t *dda = arg;
204 	dsl_dir_t *dd;
205 	dsl_pool_t *dp = dmu_tx_pool(tx);
206 	objset_t *mos = dp->dp_meta_objset;
207 	nvpair_t *whopair = NULL;
208 	uint64_t zapobj;
209 
210 	VERIFY0(dsl_dir_hold(dp, dda->dda_name, FTAG, &dd, NULL));
211 	zapobj = dsl_dir_phys(dd)->dd_deleg_zapobj;
212 	if (zapobj == 0) {
213 		dsl_dir_rele(dd, FTAG);
214 		return;
215 	}
216 
217 	while ((whopair = nvlist_next_nvpair(dda->dda_nvlist, whopair))) {
218 		const char *whokey = nvpair_name(whopair);
219 		nvlist_t *perms;
220 		nvpair_t *permpair = NULL;
221 		uint64_t jumpobj;
222 
223 		if (nvpair_value_nvlist(whopair, &perms) != 0) {
224 			if (zap_lookup(mos, zapobj, whokey, 8,
225 			    1, &jumpobj) == 0) {
226 				(void) zap_remove(mos, zapobj, whokey, tx);
227 				VERIFY(0 == zap_destroy(mos, jumpobj, tx));
228 			}
229 			spa_history_log_internal_dd(dd, "permission who remove",
230 			    tx, "%s", whokey);
231 			continue;
232 		}
233 
234 		if (zap_lookup(mos, zapobj, whokey, 8, 1, &jumpobj) != 0)
235 			continue;
236 
237 		while ((permpair = nvlist_next_nvpair(perms, permpair))) {
238 			const char *perm = nvpair_name(permpair);
239 			uint64_t n = 0;
240 
241 			(void) zap_remove(mos, jumpobj, perm, tx);
242 			if (zap_count(mos, jumpobj, &n) == 0 && n == 0) {
243 				(void) zap_remove(mos, zapobj,
244 				    whokey, tx);
245 				VERIFY(0 == zap_destroy(mos,
246 				    jumpobj, tx));
247 			}
248 			spa_history_log_internal_dd(dd, "permission remove", tx,
249 			    "%s %s", whokey, perm);
250 		}
251 	}
252 	dsl_dir_rele(dd, FTAG);
253 }
254 
255 static int
dsl_deleg_check(void * arg,dmu_tx_t * tx)256 dsl_deleg_check(void *arg, dmu_tx_t *tx)
257 {
258 	dsl_deleg_arg_t *dda = arg;
259 	dsl_dir_t *dd;
260 	int error;
261 
262 	if (spa_version(dmu_tx_pool(tx)->dp_spa) <
263 	    SPA_VERSION_DELEGATED_PERMS) {
264 		return (SET_ERROR(ENOTSUP));
265 	}
266 
267 	error = dsl_dir_hold(dmu_tx_pool(tx), dda->dda_name, FTAG, &dd, NULL);
268 	if (error == 0)
269 		dsl_dir_rele(dd, FTAG);
270 	return (error);
271 }
272 
273 int
dsl_deleg_set(const char * ddname,nvlist_t * nvp,boolean_t unset)274 dsl_deleg_set(const char *ddname, nvlist_t *nvp, boolean_t unset)
275 {
276 	dsl_deleg_arg_t dda;
277 
278 	/* nvp must already have been verified to be valid */
279 
280 	dda.dda_name = ddname;
281 	dda.dda_nvlist = nvp;
282 
283 	return (dsl_sync_task(ddname, dsl_deleg_check,
284 	    unset ? dsl_deleg_unset_sync : dsl_deleg_set_sync,
285 	    &dda, fnvlist_num_pairs(nvp), ZFS_SPACE_CHECK_RESERVED));
286 }
287 
288 /*
289  * Find all 'allow' permissions from a given point and then continue
290  * traversing up to the root.
291  *
292  * This function constructs an nvlist of nvlists.
293  * each setpoint is an nvlist composed of an nvlist of an nvlist
294  * of the individual * users/groups/everyone/create
295  * permissions.
296  *
297  * The nvlist will look like this.
298  *
299  * { source fsname -> { whokeys { permissions,...}, ...}}
300  *
301  * The fsname nvpairs will be arranged in a bottom up order.  For example,
302  * if we have the following structure a/b/c then the nvpairs for the fsnames
303  * will be ordered a/b/c, a/b, a.
304  */
305 int
dsl_deleg_get(const char * ddname,nvlist_t ** nvp)306 dsl_deleg_get(const char *ddname, nvlist_t **nvp)
307 {
308 	dsl_dir_t *dd, *startdd;
309 	dsl_pool_t *dp;
310 	int error;
311 	objset_t *mos;
312 	zap_cursor_t *basezc, *zc;
313 	zap_attribute_t *baseza, *za;
314 	char *source;
315 
316 	error = dsl_pool_hold(ddname, FTAG, &dp);
317 	if (error != 0)
318 		return (error);
319 
320 	error = dsl_dir_hold(dp, ddname, FTAG, &startdd, NULL);
321 	if (error != 0) {
322 		dsl_pool_rele(dp, FTAG);
323 		return (error);
324 	}
325 
326 	dp = startdd->dd_pool;
327 	mos = dp->dp_meta_objset;
328 
329 	zc = kmem_alloc(sizeof (zap_cursor_t), KM_SLEEP);
330 	za = zap_attribute_alloc();
331 	basezc = kmem_alloc(sizeof (zap_cursor_t), KM_SLEEP);
332 	baseza = zap_attribute_alloc();
333 	source = kmem_alloc(ZFS_MAX_DATASET_NAME_LEN, KM_SLEEP);
334 	VERIFY(nvlist_alloc(nvp, NV_UNIQUE_NAME, KM_SLEEP) == 0);
335 
336 	for (dd = startdd; dd != NULL; dd = dd->dd_parent) {
337 		nvlist_t *sp_nvp;
338 		uint64_t n;
339 
340 		if (dsl_dir_phys(dd)->dd_deleg_zapobj == 0 ||
341 		    zap_count(mos,
342 		    dsl_dir_phys(dd)->dd_deleg_zapobj, &n) != 0 || n == 0)
343 			continue;
344 
345 		sp_nvp = fnvlist_alloc();
346 		for (zap_cursor_init(basezc, mos,
347 		    dsl_dir_phys(dd)->dd_deleg_zapobj);
348 		    zap_cursor_retrieve(basezc, baseza) == 0;
349 		    zap_cursor_advance(basezc)) {
350 			nvlist_t *perms_nvp;
351 
352 			ASSERT(baseza->za_integer_length == 8);
353 			ASSERT(baseza->za_num_integers == 1);
354 
355 			perms_nvp = fnvlist_alloc();
356 			for (zap_cursor_init(zc, mos, baseza->za_first_integer);
357 			    zap_cursor_retrieve(zc, za) == 0;
358 			    zap_cursor_advance(zc)) {
359 				fnvlist_add_boolean(perms_nvp, za->za_name);
360 			}
361 			zap_cursor_fini(zc);
362 			fnvlist_add_nvlist(sp_nvp, baseza->za_name, perms_nvp);
363 			fnvlist_free(perms_nvp);
364 		}
365 
366 		zap_cursor_fini(basezc);
367 
368 		dsl_dir_name(dd, source);
369 		fnvlist_add_nvlist(*nvp, source, sp_nvp);
370 		nvlist_free(sp_nvp);
371 	}
372 
373 	kmem_free(source, ZFS_MAX_DATASET_NAME_LEN);
374 	zap_attribute_free(baseza);
375 	kmem_free(basezc, sizeof (zap_cursor_t));
376 	zap_attribute_free(za);
377 	kmem_free(zc, sizeof (zap_cursor_t));
378 
379 	dsl_dir_rele(startdd, FTAG);
380 	dsl_pool_rele(dp, FTAG);
381 	return (0);
382 }
383 
384 /*
385  * Routines for dsl_deleg_access() -- access checking.
386  */
387 typedef struct perm_set {
388 	avl_node_t	p_node;
389 	boolean_t	p_matched;
390 	char		p_setname[ZFS_MAX_DELEG_NAME];
391 } perm_set_t;
392 
393 static int
perm_set_compare(const void * arg1,const void * arg2)394 perm_set_compare(const void *arg1, const void *arg2)
395 {
396 	const perm_set_t *node1 = (const perm_set_t *)arg1;
397 	const perm_set_t *node2 = (const perm_set_t *)arg2;
398 	int val;
399 
400 	val = strcmp(node1->p_setname, node2->p_setname);
401 
402 	return (TREE_ISIGN(val));
403 }
404 
405 /*
406  * Determine whether a specified permission exists.
407  *
408  * First the base attribute has to be retrieved.  i.e. ul$12
409  * Once the base object has been retrieved the actual permission
410  * is lookup up in the zap object the base object points to.
411  *
412  * Return 0 if permission exists, ENOENT if there is no whokey, EPERM if
413  * there is no perm in that jumpobj.
414  */
415 static int
dsl_check_access(objset_t * mos,uint64_t zapobj,char type,char checkflag,void * valp,const char * perm)416 dsl_check_access(objset_t *mos, uint64_t zapobj,
417     char type, char checkflag, void *valp, const char *perm)
418 {
419 	int error;
420 	uint64_t jumpobj, zero;
421 	char whokey[ZFS_MAX_DELEG_NAME];
422 
423 	zfs_deleg_whokey(whokey, type, checkflag, valp);
424 	error = zap_lookup(mos, zapobj, whokey, 8, 1, &jumpobj);
425 	if (error == 0) {
426 		error = zap_lookup(mos, jumpobj, perm, 8, 1, &zero);
427 		if (error == ENOENT)
428 			error = SET_ERROR(EPERM);
429 	}
430 	return (error);
431 }
432 
433 /*
434  * check a specified user/group for a requested permission
435  */
436 static int
dsl_check_user_access(objset_t * mos,uint64_t zapobj,const char * perm,int checkflag,cred_t * cr)437 dsl_check_user_access(objset_t *mos, uint64_t zapobj, const char *perm,
438     int checkflag, cred_t *cr)
439 {
440 	const	gid_t *gids;
441 	int	ngids;
442 	int	i;
443 	uint64_t id;
444 
445 	/* check for user */
446 	id = crgetuid(cr);
447 	if (dsl_check_access(mos, zapobj,
448 	    ZFS_DELEG_USER, checkflag, &id, perm) == 0)
449 		return (0);
450 
451 	/* check for users primary group */
452 	id = crgetgid(cr);
453 	if (dsl_check_access(mos, zapobj,
454 	    ZFS_DELEG_GROUP, checkflag, &id, perm) == 0)
455 		return (0);
456 
457 	/* check for everyone entry */
458 	id = -1;
459 	if (dsl_check_access(mos, zapobj,
460 	    ZFS_DELEG_EVERYONE, checkflag, &id, perm) == 0)
461 		return (0);
462 
463 	/* check each supplemental group user is a member of */
464 	ngids = crgetngroups(cr);
465 	gids = crgetgroups(cr);
466 	for (i = 0; i != ngids; i++) {
467 		id = gids[i];
468 		if (dsl_check_access(mos, zapobj,
469 		    ZFS_DELEG_GROUP, checkflag, &id, perm) == 0)
470 			return (0);
471 	}
472 
473 	return (SET_ERROR(EPERM));
474 }
475 
476 /*
477  * Iterate over the sets specified in the specified zapobj
478  * and load them into the permsets avl tree.
479  */
480 static int
dsl_load_sets(objset_t * mos,uint64_t zapobj,char type,char checkflag,void * valp,avl_tree_t * avl)481 dsl_load_sets(objset_t *mos, uint64_t zapobj,
482     char type, char checkflag, void *valp, avl_tree_t *avl)
483 {
484 	zap_cursor_t zc;
485 	zap_attribute_t *za;
486 	perm_set_t *permnode;
487 	avl_index_t idx;
488 	uint64_t jumpobj;
489 	int error;
490 	char whokey[ZFS_MAX_DELEG_NAME];
491 
492 	zfs_deleg_whokey(whokey, type, checkflag, valp);
493 
494 	error = zap_lookup(mos, zapobj, whokey, 8, 1, &jumpobj);
495 	if (error != 0)
496 		return (error);
497 
498 	za = zap_attribute_alloc();
499 	for (zap_cursor_init(&zc, mos, jumpobj);
500 	    zap_cursor_retrieve(&zc, za) == 0;
501 	    zap_cursor_advance(&zc)) {
502 		permnode = kmem_alloc(sizeof (perm_set_t), KM_SLEEP);
503 		(void) strlcpy(permnode->p_setname, za->za_name,
504 		    sizeof (permnode->p_setname));
505 		permnode->p_matched = B_FALSE;
506 
507 		if (avl_find(avl, permnode, &idx) == NULL) {
508 			avl_insert(avl, permnode, idx);
509 		} else {
510 			kmem_free(permnode, sizeof (perm_set_t));
511 		}
512 	}
513 	zap_cursor_fini(&zc);
514 	zap_attribute_free(za);
515 	return (0);
516 }
517 
518 /*
519  * Load all permissions user based on cred belongs to.
520  */
521 static void
dsl_load_user_sets(objset_t * mos,uint64_t zapobj,avl_tree_t * avl,char checkflag,cred_t * cr)522 dsl_load_user_sets(objset_t *mos, uint64_t zapobj, avl_tree_t *avl,
523     char checkflag, cred_t *cr)
524 {
525 	const	gid_t *gids;
526 	int	ngids, i;
527 	uint64_t id;
528 
529 	id = crgetuid(cr);
530 	(void) dsl_load_sets(mos, zapobj,
531 	    ZFS_DELEG_USER_SETS, checkflag, &id, avl);
532 
533 	id = crgetgid(cr);
534 	(void) dsl_load_sets(mos, zapobj,
535 	    ZFS_DELEG_GROUP_SETS, checkflag, &id, avl);
536 
537 	(void) dsl_load_sets(mos, zapobj,
538 	    ZFS_DELEG_EVERYONE_SETS, checkflag, NULL, avl);
539 
540 	ngids = crgetngroups(cr);
541 	gids = crgetgroups(cr);
542 	for (i = 0; i != ngids; i++) {
543 		id = gids[i];
544 		(void) dsl_load_sets(mos, zapobj,
545 		    ZFS_DELEG_GROUP_SETS, checkflag, &id, avl);
546 	}
547 }
548 
549 /*
550  * Check if user has requested permission.
551  */
552 int
dsl_deleg_access_impl(dsl_dataset_t * ds,const char * perm,cred_t * cr)553 dsl_deleg_access_impl(dsl_dataset_t *ds, const char *perm, cred_t *cr)
554 {
555 	dsl_dir_t *dd;
556 	dsl_pool_t *dp;
557 	void *cookie;
558 	int	error;
559 	char	checkflag;
560 	objset_t *mos;
561 	avl_tree_t permsets;
562 	perm_set_t *setnode;
563 
564 	dp = ds->ds_dir->dd_pool;
565 	mos = dp->dp_meta_objset;
566 
567 	if (dsl_delegation_on(mos) == B_FALSE)
568 		return (SET_ERROR(ECANCELED));
569 
570 	if (spa_version(dmu_objset_spa(dp->dp_meta_objset)) <
571 	    SPA_VERSION_DELEGATED_PERMS)
572 		return (SET_ERROR(EPERM));
573 
574 	if (ds->ds_is_snapshot) {
575 		/*
576 		 * Snapshots are treated as descendents only,
577 		 * local permissions do not apply.
578 		 */
579 		checkflag = ZFS_DELEG_DESCENDENT;
580 	} else {
581 		checkflag = ZFS_DELEG_LOCAL;
582 	}
583 
584 	avl_create(&permsets, perm_set_compare, sizeof (perm_set_t),
585 	    offsetof(perm_set_t, p_node));
586 
587 	ASSERT(dsl_pool_config_held(dp));
588 	for (dd = ds->ds_dir; dd != NULL; dd = dd->dd_parent,
589 	    checkflag = ZFS_DELEG_DESCENDENT) {
590 		uint64_t zapobj;
591 		boolean_t expanded;
592 
593 		/*
594 		 * If not in global zone then make sure
595 		 * the zoned property is set
596 		 */
597 		if (!INGLOBALZONE(curproc)) {
598 			uint64_t zoned;
599 
600 			if (dsl_prop_get_dd(dd,
601 			    zfs_prop_to_name(ZFS_PROP_ZONED),
602 			    8, 1, &zoned, NULL, B_FALSE) != 0)
603 				break;
604 			if (!zoned)
605 				break;
606 		}
607 		zapobj = dsl_dir_phys(dd)->dd_deleg_zapobj;
608 
609 		if (zapobj == 0)
610 			continue;
611 
612 		dsl_load_user_sets(mos, zapobj, &permsets, checkflag, cr);
613 again:
614 		expanded = B_FALSE;
615 		for (setnode = avl_first(&permsets); setnode;
616 		    setnode = AVL_NEXT(&permsets, setnode)) {
617 			if (setnode->p_matched == B_TRUE)
618 				continue;
619 
620 			/* See if this set directly grants this permission */
621 			error = dsl_check_access(mos, zapobj,
622 			    ZFS_DELEG_NAMED_SET, 0, setnode->p_setname, perm);
623 			if (error == 0)
624 				goto success;
625 			if (error == EPERM)
626 				setnode->p_matched = B_TRUE;
627 
628 			/* See if this set includes other sets */
629 			error = dsl_load_sets(mos, zapobj,
630 			    ZFS_DELEG_NAMED_SET_SETS, 0,
631 			    setnode->p_setname, &permsets);
632 			if (error == 0)
633 				setnode->p_matched = expanded = B_TRUE;
634 		}
635 		/*
636 		 * If we expanded any sets, that will define more sets,
637 		 * which we need to check.
638 		 */
639 		if (expanded)
640 			goto again;
641 
642 		error = dsl_check_user_access(mos, zapobj, perm, checkflag, cr);
643 		if (error == 0)
644 			goto success;
645 	}
646 	error = SET_ERROR(EPERM);
647 success:
648 
649 	cookie = NULL;
650 	while ((setnode = avl_destroy_nodes(&permsets, &cookie)) != NULL)
651 		kmem_free(setnode, sizeof (perm_set_t));
652 
653 	return (error);
654 }
655 
656 int
dsl_deleg_access(const char * dsname,const char * perm,cred_t * cr)657 dsl_deleg_access(const char *dsname, const char *perm, cred_t *cr)
658 {
659 	dsl_pool_t *dp;
660 	dsl_dataset_t *ds;
661 	int error;
662 
663 	error = dsl_pool_hold(dsname, FTAG, &dp);
664 	if (error != 0)
665 		return (error);
666 	error = dsl_dataset_hold(dp, dsname, FTAG, &ds);
667 	if (error == 0) {
668 		error = dsl_deleg_access_impl(ds, perm, cr);
669 		dsl_dataset_rele(ds, FTAG);
670 	}
671 	dsl_pool_rele(dp, FTAG);
672 
673 	return (error);
674 }
675 
676 /*
677  * Other routines.
678  */
679 
680 static void
copy_create_perms(dsl_dir_t * dd,uint64_t pzapobj,boolean_t dosets,uint64_t uid,dmu_tx_t * tx)681 copy_create_perms(dsl_dir_t *dd, uint64_t pzapobj,
682     boolean_t dosets, uint64_t uid, dmu_tx_t *tx)
683 {
684 	objset_t *mos = dd->dd_pool->dp_meta_objset;
685 	uint64_t jumpobj, pjumpobj;
686 	uint64_t zapobj = dsl_dir_phys(dd)->dd_deleg_zapobj;
687 	zap_cursor_t zc;
688 	zap_attribute_t *za;
689 	char whokey[ZFS_MAX_DELEG_NAME];
690 
691 	zfs_deleg_whokey(whokey,
692 	    dosets ? ZFS_DELEG_CREATE_SETS : ZFS_DELEG_CREATE,
693 	    ZFS_DELEG_LOCAL, NULL);
694 	if (zap_lookup(mos, pzapobj, whokey, 8, 1, &pjumpobj) != 0)
695 		return;
696 
697 	if (zapobj == 0) {
698 		dmu_buf_will_dirty(dd->dd_dbuf, tx);
699 		zapobj = dsl_dir_phys(dd)->dd_deleg_zapobj = zap_create(mos,
700 		    DMU_OT_DSL_PERMS, DMU_OT_NONE, 0, tx);
701 	}
702 
703 	zfs_deleg_whokey(whokey,
704 	    dosets ? ZFS_DELEG_USER_SETS : ZFS_DELEG_USER,
705 	    ZFS_DELEG_LOCAL, &uid);
706 	if (zap_lookup(mos, zapobj, whokey, 8, 1, &jumpobj) == ENOENT) {
707 		jumpobj = zap_create(mos, DMU_OT_DSL_PERMS, DMU_OT_NONE, 0, tx);
708 		VERIFY(zap_add(mos, zapobj, whokey, 8, 1, &jumpobj, tx) == 0);
709 	}
710 
711 	za = zap_attribute_alloc();
712 	for (zap_cursor_init(&zc, mos, pjumpobj);
713 	    zap_cursor_retrieve(&zc, za) == 0;
714 	    zap_cursor_advance(&zc)) {
715 		uint64_t zero = 0;
716 		ASSERT(za->za_integer_length == 8 && za->za_num_integers == 1);
717 
718 		VERIFY(zap_update(mos, jumpobj, za->za_name,
719 		    8, 1, &zero, tx) == 0);
720 	}
721 	zap_cursor_fini(&zc);
722 	zap_attribute_free(za);
723 }
724 
725 /*
726  * set all create time permission on new dataset.
727  */
728 void
dsl_deleg_set_create_perms(dsl_dir_t * sdd,dmu_tx_t * tx,cred_t * cr)729 dsl_deleg_set_create_perms(dsl_dir_t *sdd, dmu_tx_t *tx, cred_t *cr)
730 {
731 	dsl_dir_t *dd;
732 	uint64_t uid = crgetuid(cr);
733 
734 	if (spa_version(dmu_objset_spa(sdd->dd_pool->dp_meta_objset)) <
735 	    SPA_VERSION_DELEGATED_PERMS)
736 		return;
737 
738 	for (dd = sdd->dd_parent; dd != NULL; dd = dd->dd_parent) {
739 		uint64_t pzapobj = dsl_dir_phys(dd)->dd_deleg_zapobj;
740 
741 		if (pzapobj == 0)
742 			continue;
743 
744 		copy_create_perms(sdd, pzapobj, B_FALSE, uid, tx);
745 		copy_create_perms(sdd, pzapobj, B_TRUE, uid, tx);
746 	}
747 }
748 
749 int
dsl_deleg_destroy(objset_t * mos,uint64_t zapobj,dmu_tx_t * tx)750 dsl_deleg_destroy(objset_t *mos, uint64_t zapobj, dmu_tx_t *tx)
751 {
752 	zap_cursor_t zc;
753 	zap_attribute_t *za;
754 
755 	if (zapobj == 0)
756 		return (0);
757 
758 	za = zap_attribute_alloc();
759 	for (zap_cursor_init(&zc, mos, zapobj);
760 	    zap_cursor_retrieve(&zc, za) == 0;
761 	    zap_cursor_advance(&zc)) {
762 		ASSERT(za->za_integer_length == 8 && za->za_num_integers == 1);
763 		VERIFY(0 == zap_destroy(mos, za->za_first_integer, tx));
764 	}
765 	zap_cursor_fini(&zc);
766 	VERIFY(0 == zap_destroy(mos, zapobj, tx));
767 	zap_attribute_free(za);
768 	return (0);
769 }
770 
771 boolean_t
dsl_delegation_on(objset_t * os)772 dsl_delegation_on(objset_t *os)
773 {
774 	return (!!spa_delegation(os->os_spa));
775 }
776 
777 #if defined(_KERNEL)
778 EXPORT_SYMBOL(dsl_deleg_get);
779 EXPORT_SYMBOL(dsl_deleg_set);
780 #endif
781