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