source4/ntvfs/posix/pvfs_acl.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3
   4    POSIX NTVFS backend - ACL support
   5
   6    Copyright (C) Andrew Tridgell 2004
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "auth/auth.h"
  24 #include "vfs_posix.h"
  25 #include "librpc/gen_ndr/xattr.h"
  26 #include "libcli/security/security.h"
  27 #include "param/param.h"
  28
  29
  30 /* the list of currently registered ACL backends */
  31 static struct pvfs_acl_backend {
  32         const struct pvfs_acl_ops *ops;
  33 } *backends = NULL;
  34 static int num_backends;
  35
  36 /*
  37   register a pvfs acl backend.
  38
  39   The 'name' can be later used by other backends to find the operations
  40   structure for this backend.
  41 */
  42 NTSTATUS pvfs_acl_register(const struct pvfs_acl_ops *ops)
  43 {
  44         struct pvfs_acl_ops *new_ops;
  45
  46         if (pvfs_acl_backend_byname(ops->name) != NULL) {
  47                 DEBUG(0,("pvfs acl backend '%s' already registered\n", ops->name));
  48                 return NT_STATUS_OBJECT_NAME_COLLISION;
  49         }
  50
  51         backends = talloc_realloc(talloc_autofree_context(), backends, struct pvfs_acl_backend, num_backends+1);
  52         NT_STATUS_HAVE_NO_MEMORY(backends);
  53
  54         new_ops = (struct pvfs_acl_ops *)talloc_memdup(backends, ops, sizeof(*ops));
  55         new_ops->name = talloc_strdup(new_ops, ops->name);
  56
  57         backends[num_backends].ops = new_ops;
  58
  59         num_backends++;
  60
  61         DEBUG(3,("NTVFS backend '%s' registered\n", ops->name));
  62
  63         return NT_STATUS_OK;
  64 }
  65
  66
  67 /*
  68   return the operations structure for a named backend
  69 */
  70 const struct pvfs_acl_ops *pvfs_acl_backend_byname(const char *name)
  71 {
  72         int i;
  73
  74         for (i=0;i<num_backends;i++) {
  75                 if (strcmp(backends[i].ops->name, name) == 0) {
  76                         return backends[i].ops;
  77                 }
  78         }
  79
  80         return NULL;
  81 }
  82
  83 NTSTATUS pvfs_acl_init(struct loadparm_context *lp_ctx)
  84 {
  85         static bool initialized = false;
  86         extern NTSTATUS pvfs_acl_nfs4_init(void);
  87         extern NTSTATUS pvfs_acl_xattr_init(void);
  88         init_module_fn static_init[] = { STATIC_pvfs_acl_MODULES };
  89         init_module_fn *shared_init;
  90
  91         if (initialized) return NT_STATUS_OK;
  92         initialized = true;
  93
  94         shared_init = load_samba_modules(NULL, lp_ctx, "pvfs_acl");
  95
  96         run_init_functions(static_init);
  97         run_init_functions(shared_init);
  98
  99         talloc_free(shared_init);
 100
 101         return NT_STATUS_OK;
 102 }
 103
 104
 105 /*
 106   map a single access_mask from generic to specific bits for files/dirs
 107 */
 108 static uint32_t pvfs_translate_mask(uint32_t access_mask)
 109 {
 110         if (access_mask & SEC_MASK_GENERIC) {
 111                 if (access_mask & SEC_GENERIC_READ)    access_mask |= SEC_RIGHTS_FILE_READ;
 112                 if (access_mask & SEC_GENERIC_WRITE)   access_mask |= SEC_RIGHTS_FILE_WRITE;
 113                 if (access_mask & SEC_GENERIC_EXECUTE) access_mask |= SEC_RIGHTS_FILE_EXECUTE;
 114                 if (access_mask & SEC_GENERIC_ALL)     access_mask |= SEC_RIGHTS_FILE_ALL;
 115                 access_mask &= ~SEC_MASK_GENERIC;
 116         }
 117         return access_mask;
 118 }
 119
 120
 121 /*
 122   map any generic access bits in the given acl
 123   this relies on the fact that the mappings for files and directories
 124   are the same
 125 */
 126 static void pvfs_translate_generic_bits(struct security_acl *acl)
 127 {
 128         unsigned i;
 129
 130         if (!acl) return;
 131
 132         for (i=0;i<acl->num_aces;i++) {
 133                 struct security_ace *ace = &acl->aces[i];
 134                 ace->access_mask = pvfs_translate_mask(ace->access_mask);
 135         }
 136 }
 137
 138
 139 /*
 140   setup a default ACL for a file
 141 */
 142 static NTSTATUS pvfs_default_acl(struct pvfs_state *pvfs,
 143                                  struct ntvfs_request *req,
 144                                  struct pvfs_filename *name, int fd,
 145                                  struct security_descriptor **psd)
 146 {
 147         struct security_descriptor *sd;
 148         NTSTATUS status;
 149         struct security_ace ace;
 150         mode_t mode;
 151         struct id_mapping *ids;
 152         struct composite_context *ctx;
 153
 154         *psd = security_descriptor_initialise(req);
 155         if (*psd == NULL) {
 156                 return NT_STATUS_NO_MEMORY;
 157         }
 158         sd = *psd;
 159
 160         ids = talloc_zero_array(sd, struct id_mapping, 2);
 161         NT_STATUS_HAVE_NO_MEMORY(ids);
 162
 163         ids[0].unixid = talloc(ids, struct unixid);
 164         NT_STATUS_HAVE_NO_MEMORY(ids[0].unixid);
 165
 166         ids[0].unixid->id = name->st.st_uid;
 167         ids[0].unixid->type = ID_TYPE_UID;
 168         ids[0].sid = NULL;
 169
 170         ids[1].unixid = talloc(ids, struct unixid);
 171         NT_STATUS_HAVE_NO_MEMORY(ids[1].unixid);
 172
 173         ids[1].unixid->id = name->st.st_gid;
 174         ids[1].unixid->type = ID_TYPE_GID;
 175         ids[1].sid = NULL;
 176
 177         ctx = wbc_xids_to_sids_send(pvfs->wbc_ctx, ids, 2, ids);
 178         NT_STATUS_HAVE_NO_MEMORY(ctx);
 179
 180         status = wbc_xids_to_sids_recv(ctx, &ids);
 181         NT_STATUS_NOT_OK_RETURN(status);
 182
 183         sd->owner_sid = talloc_steal(sd, ids[0].sid);
 184         sd->group_sid = talloc_steal(sd, ids[1].sid);
 185
 186         talloc_free(ids);
 187         sd->type |= SEC_DESC_DACL_PRESENT;
 188
 189         mode = name->st.st_mode;
 190
 191         /*
 192           we provide up to 4 ACEs
 193             - Owner
 194             - Group
 195             - Everyone
 196             - Administrator
 197          */
 198
 199
 200         /* setup owner ACE */
 201         ace.type = SEC_ACE_TYPE_ACCESS_ALLOWED;
 202         ace.flags = 0;
 203         ace.trustee = *sd->owner_sid;
 204         ace.access_mask = 0;
 205
 206         if (mode & S_IRUSR) {
 207                 if (mode & S_IWUSR) {
 208                         ace.access_mask |= SEC_RIGHTS_FILE_ALL;
 209                 } else {
 210                         ace.access_mask |= SEC_RIGHTS_FILE_READ | SEC_FILE_EXECUTE;
 211                 }
 212         }
 213         if (mode & S_IWUSR) {
 214                 ace.access_mask |= SEC_RIGHTS_FILE_WRITE | SEC_STD_DELETE;
 215         }
 216         if (ace.access_mask) {
 217                 security_descriptor_dacl_add(sd, &ace);
 218         }
 219
 220
 221         /* setup group ACE */
 222         ace.trustee = *sd->group_sid;
 223         ace.access_mask = 0;
 224         if (mode & S_IRGRP) {
 225                 ace.access_mask |= SEC_RIGHTS_FILE_READ | SEC_FILE_EXECUTE;
 226         }
 227         if (mode & S_IWGRP) {
 228                 /* note that delete is not granted - this matches posix behaviour */
 229                 ace.access_mask |= SEC_RIGHTS_FILE_WRITE;
 230         }
 231         if (ace.access_mask) {
 232                 security_descriptor_dacl_add(sd, &ace);
 233         }
 234
 235         /* setup other ACE */
 236         ace.trustee = *dom_sid_parse_talloc(req, SID_WORLD);
 237         ace.access_mask = 0;
 238         if (mode & S_IROTH) {
 239                 ace.access_mask |= SEC_RIGHTS_FILE_READ | SEC_FILE_EXECUTE;
 240         }
 241         if (mode & S_IWOTH) {
 242                 ace.access_mask |= SEC_RIGHTS_FILE_WRITE;
 243         }
 244         if (ace.access_mask) {
 245                 security_descriptor_dacl_add(sd, &ace);
 246         }
 247
 248         /* setup system ACE */
 249         ace.trustee = *dom_sid_parse_talloc(req, SID_NT_SYSTEM);
 250         ace.access_mask = SEC_RIGHTS_FILE_ALL;
 251         security_descriptor_dacl_add(sd, &ace);
 252
 253         return NT_STATUS_OK;
 254 }
 255
 256
 257 /*
 258   omit any security_descriptor elements not specified in the given
 259   secinfo flags
 260 */
 261 static void normalise_sd_flags(struct security_descriptor *sd, uint32_t secinfo_flags)
 262 {
 263         if (!(secinfo_flags & SECINFO_OWNER)) {
 264                 sd->owner_sid = NULL;
 265         }
 266         if (!(secinfo_flags & SECINFO_GROUP)) {
 267                 sd->group_sid = NULL;
 268         }
 269         if (!(secinfo_flags & SECINFO_DACL)) {
 270                 sd->dacl = NULL;
 271         }
 272         if (!(secinfo_flags & SECINFO_SACL)) {
 273                 sd->sacl = NULL;
 274         }
 275 }
 276
 277 /*
 278   answer a setfileinfo for an ACL
 279 */
 280 NTSTATUS pvfs_acl_set(struct pvfs_state *pvfs,
 281                       struct ntvfs_request *req,
 282                       struct pvfs_filename *name, int fd,
 283                       uint32_t access_mask,
 284                       union smb_setfileinfo *info)
 285 {
 286         uint32_t secinfo_flags = info->set_secdesc.in.secinfo_flags;
 287         struct security_descriptor *new_sd, *sd, orig_sd;
 288         NTSTATUS status = NT_STATUS_NOT_FOUND;
 289         uid_t old_uid = -1;
 290         gid_t old_gid = -1;
 291         uid_t new_uid = -1;
 292         gid_t new_gid = -1;
 293         struct id_mapping *ids;
 294         struct composite_context *ctx;
 295
 296         if (pvfs->acl_ops != NULL) {
 297                 status = pvfs->acl_ops->acl_load(pvfs, name, fd, req, &sd);
 298         }
 299         if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
 300                 status = pvfs_default_acl(pvfs, req, name, fd, &sd);
 301         }
 302         if (!NT_STATUS_IS_OK(status)) {
 303                 return status;
 304         }
 305
 306         ids = talloc(req, struct id_mapping);
 307         NT_STATUS_HAVE_NO_MEMORY(ids);
 308         ids->unixid = NULL;
 309         ids->sid = NULL;
 310         ids->status = NT_STATUS_NONE_MAPPED;
 311
 312         new_sd = info->set_secdesc.in.sd;
 313         orig_sd = *sd;
 314
 315         old_uid = name->st.st_uid;
 316         old_gid = name->st.st_gid;
 317
 318         /* only set the elements that have been specified */
 319         if (secinfo_flags & SECINFO_OWNER) {
 320                 if (!(access_mask & SEC_STD_WRITE_OWNER)) {
 321                         return NT_STATUS_ACCESS_DENIED;
 322                 }
 323                 if (!dom_sid_equal(sd->owner_sid, new_sd->owner_sid)) {
 324                         ids->sid = new_sd->owner_sid;
 325                         ctx = wbc_sids_to_xids_send(pvfs->wbc_ctx, ids, 1, ids);
 326                         NT_STATUS_HAVE_NO_MEMORY(ctx);
 327                         status = wbc_sids_to_xids_recv(ctx, &ids);
 328                         NT_STATUS_NOT_OK_RETURN(status);
 329
 330                         if (ids->unixid->type == ID_TYPE_BOTH ||
 331                             ids->unixid->type == ID_TYPE_UID) {
 332                                 new_uid = ids->unixid->id;
 333                         }
 334                 }
 335                 sd->owner_sid = new_sd->owner_sid;
 336         }
 337         if (secinfo_flags & SECINFO_GROUP) {
 338                 if (!(access_mask & SEC_STD_WRITE_OWNER)) {
 339                         return NT_STATUS_ACCESS_DENIED;
 340                 }
 341                 if (!dom_sid_equal(sd->group_sid, new_sd->group_sid)) {
 342                         ids->sid = new_sd->group_sid;
 343                         ctx = wbc_sids_to_xids_send(pvfs->wbc_ctx, ids, 1, ids);
 344                         NT_STATUS_HAVE_NO_MEMORY(ctx);
 345                         status = wbc_sids_to_xids_recv(ctx, &ids);
 346                         NT_STATUS_NOT_OK_RETURN(status);
 347
 348                         if (ids->unixid->type == ID_TYPE_BOTH ||
 349                             ids->unixid->type == ID_TYPE_GID) {
 350                                 new_gid = ids->unixid->id;
 351                         }
 352
 353                 }
 354                 sd->group_sid = new_sd->group_sid;
 355         }
 356         if (secinfo_flags & SECINFO_DACL) {
 357                 if (!(access_mask & SEC_STD_WRITE_DAC)) {
 358                         return NT_STATUS_ACCESS_DENIED;
 359                 }
 360                 sd->dacl = new_sd->dacl;
 361                 pvfs_translate_generic_bits(sd->dacl);
 362         }
 363         if (secinfo_flags & SECINFO_SACL) {
 364                 if (!(access_mask & SEC_FLAG_SYSTEM_SECURITY)) {
 365                         return NT_STATUS_ACCESS_DENIED;
 366                 }
 367                 sd->sacl = new_sd->sacl;
 368                 pvfs_translate_generic_bits(sd->sacl);
 369         }
 370
 371         if (new_uid == old_uid) {
 372                 new_uid = -1;
 373         }
 374
 375         if (new_gid == old_gid) {
 376                 new_gid = -1;
 377         }
 378
 379         /* if there's something to change try it */
 380         if (new_uid != -1 || new_gid != -1) {
 381                 int ret;
 382                 if (fd == -1) {
 383                         ret = chown(name->full_name, new_uid, new_gid);
 384                 } else {
 385                         ret = fchown(fd, new_uid, new_gid);
 386                 }
 387                 if (errno == EPERM && uwrap_enabled()) {
 388                         ret = 0;
 389                 }
 390                 if (ret == -1) {
 391                         return pvfs_map_errno(pvfs, errno);
 392                 }
 393         }
 394
 395         /* we avoid saving if the sd is the same. This means when clients
 396            copy files and end up copying the default sd that we don't
 397            needlessly use xattrs */
 398         if (!security_descriptor_equal(sd, &orig_sd) && pvfs->acl_ops) {
 399                 status = pvfs->acl_ops->acl_save(pvfs, name, fd, sd);
 400         }
 401
 402         return status;
 403 }
 404
 405
 406 /*
 407   answer a fileinfo query for the ACL
 408 */
 409 NTSTATUS pvfs_acl_query(struct pvfs_state *pvfs,
 410                         struct ntvfs_request *req,
 411                         struct pvfs_filename *name, int fd,
 412                         union smb_fileinfo *info)
 413 {
 414         NTSTATUS status = NT_STATUS_NOT_FOUND;
 415         struct security_descriptor *sd;
 416
 417         if (pvfs->acl_ops) {
 418                 status = pvfs->acl_ops->acl_load(pvfs, name, fd, req, &sd);
 419         }
 420         if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
 421                 status = pvfs_default_acl(pvfs, req, name, fd, &sd);
 422         }
 423         if (!NT_STATUS_IS_OK(status)) {
 424                 return status;
 425         }
 426
 427         normalise_sd_flags(sd, info->query_secdesc.in.secinfo_flags);
 428
 429         info->query_secdesc.out.sd = sd;
 430
 431         return NT_STATUS_OK;
 432 }
 433
 434
 435 /*
 436   check the read only bit against any of the write access bits
 437 */
 438 static bool pvfs_read_only(struct pvfs_state *pvfs, uint32_t access_mask)
 439 {
 440         if ((pvfs->flags & PVFS_FLAG_READONLY) &&
 441             (access_mask & (SEC_FILE_WRITE_DATA |
 442                             SEC_FILE_APPEND_DATA |
 443                             SEC_FILE_WRITE_EA |
 444                             SEC_FILE_WRITE_ATTRIBUTE |
 445                             SEC_STD_DELETE |
 446                             SEC_STD_WRITE_DAC |
 447                             SEC_STD_WRITE_OWNER |
 448                             SEC_DIR_DELETE_CHILD))) {
 449                 return true;
 450         }
 451         return false;
 452 }
 453
 454 /*
 455   see if we are a member of the appropriate unix group
 456  */
 457 static bool pvfs_group_member(struct pvfs_state *pvfs, gid_t gid)
 458 {
 459         int i, ngroups;
 460         gid_t *groups;
 461         if (getegid() == gid) {
 462                 return true;
 463         }
 464         ngroups = getgroups(0, NULL);
 465         if (ngroups == 0) {
 466                 return false;
 467         }
 468         groups = talloc_array(pvfs, gid_t, ngroups);
 469         if (groups == NULL) {
 470                 return false;
 471         }
 472         if (getgroups(ngroups, groups) != ngroups) {
 473                 talloc_free(groups);
 474                 return false;
 475         }
 476         for (i=0; i<ngroups; i++) {
 477                 if (groups[i] == gid) break;
 478         }
 479         talloc_free(groups);
 480         return i < ngroups;
 481 }
 482
 483 /*
 484   default access check function based on unix permissions
 485   doing this saves on building a full security descriptor
 486   for the common case of access check on files with no
 487   specific NT ACL
 488
 489   If name is NULL then treat as a new file creation
 490 */
 491 NTSTATUS pvfs_access_check_unix(struct pvfs_state *pvfs,
 492                                 struct ntvfs_request *req,
 493                                 struct pvfs_filename *name,
 494                                 uint32_t *access_mask)
 495 {
 496         uid_t uid = geteuid();
 497         uint32_t max_bits = SEC_RIGHTS_FILE_READ | SEC_FILE_ALL;
 498         struct security_token *token = req->session_info->security_token;
 499
 500         if (pvfs_read_only(pvfs, *access_mask)) {
 501                 return NT_STATUS_ACCESS_DENIED;
 502         }
 503
 504         if (name == NULL || uid == name->st.st_uid) {
 505                 max_bits |= SEC_STD_ALL;
 506         } else if (security_token_has_privilege(token, SEC_PRIV_RESTORE)) {
 507                 max_bits |= SEC_STD_DELETE;
 508         }
 509
 510         if (name == NULL ||
 511             (name->st.st_mode & S_IWOTH) ||
 512             ((name->st.st_mode & S_IWGRP) &&
 513              pvfs_group_member(pvfs, name->st.st_gid))) {
 514                 max_bits |= SEC_STD_ALL;
 515         }
 516
 517         if (uwrap_enabled()) {
 518                 /* when running with the uid wrapper, files will be created
 519                    owned by the ruid, but we may have a different simulated
 520                    euid. We need to force the permission bits as though the
 521                    files owner matches the euid */
 522                 max_bits |= SEC_STD_ALL;
 523         }
 524
 525         if (*access_mask & SEC_FLAG_MAXIMUM_ALLOWED) {
 526                 *access_mask |= max_bits;
 527                 *access_mask &= ~SEC_FLAG_MAXIMUM_ALLOWED;
 528         }
 529
 530         if ((*access_mask & SEC_FLAG_SYSTEM_SECURITY) &&
 531             security_token_has_privilege(token, SEC_PRIV_SECURITY)) {
 532                 max_bits |= SEC_FLAG_SYSTEM_SECURITY;
 533         }
 534
 535         if (((*access_mask & ~max_bits) & SEC_RIGHTS_PRIV_RESTORE) &&
 536             security_token_has_privilege(token, SEC_PRIV_RESTORE)) {
 537                 max_bits |= ~(SEC_RIGHTS_PRIV_RESTORE);
 538         }
 539         if (((*access_mask & ~max_bits) & SEC_RIGHTS_PRIV_BACKUP) &&
 540             security_token_has_privilege(token, SEC_PRIV_BACKUP)) {
 541                 max_bits |= ~(SEC_RIGHTS_PRIV_BACKUP);
 542         }
 543
 544         if (*access_mask & ~max_bits) {
 545                 DEBUG(0,(__location__ " denied access to '%s' - wanted 0x%08x but got 0x%08x (missing 0x%08x)\n",
 546                          name?name->full_name:"(new file)", *access_mask, max_bits, *access_mask & ~max_bits));
 547                 return NT_STATUS_ACCESS_DENIED;
 548         }
 549
 550         if (pvfs->ntvfs->ctx->protocol != PROTOCOL_SMB2) {
 551                 /* on SMB, this bit is always granted, even if not
 552                    asked for */
 553                 *access_mask |= SEC_FILE_READ_ATTRIBUTE;
 554         }
 555
 556         return NT_STATUS_OK;
 557 }
 558
 559
 560 /*
 561   check the security descriptor on a file, if any
 562
 563   *access_mask is modified with the access actually granted
 564 */
 565 NTSTATUS pvfs_access_check(struct pvfs_state *pvfs,
 566                            struct ntvfs_request *req,
 567                            struct pvfs_filename *name,
 568                            uint32_t *access_mask)
 569 {
 570         struct security_token *token = req->session_info->security_token;
 571         struct xattr_NTACL *acl;
 572         NTSTATUS status;
 573         struct security_descriptor *sd;
 574
 575         /* on SMB2 a blank access mask is always denied */
 576         if (pvfs->ntvfs->ctx->protocol == PROTOCOL_SMB2 &&
 577             *access_mask == 0) {
 578                 return NT_STATUS_ACCESS_DENIED;
 579         }
 580
 581         if (pvfs_read_only(pvfs, *access_mask)) {
 582                 return NT_STATUS_ACCESS_DENIED;
 583         }
 584
 585         acl = talloc(req, struct xattr_NTACL);
 586         if (acl == NULL) {
 587                 return NT_STATUS_NO_MEMORY;
 588         }
 589
 590         /* expand the generic access bits to file specific bits */
 591         *access_mask = pvfs_translate_mask(*access_mask);
 592         if (pvfs->ntvfs->ctx->protocol != PROTOCOL_SMB2) {
 593                 *access_mask &= ~SEC_FILE_READ_ATTRIBUTE;
 594         }
 595
 596         status = pvfs_acl_load(pvfs, name, -1, acl);
 597         if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
 598                 talloc_free(acl);
 599                 return pvfs_access_check_unix(pvfs, req, name, access_mask);
 600         }
 601         if (!NT_STATUS_IS_OK(status)) {
 602                 return status;
 603         }
 604
 605         switch (acl->version) {
 606         case 1:
 607                 sd = acl->info.sd;
 608                 break;
 609         default:
 610                 return NT_STATUS_INVALID_ACL;
 611         }
 612
 613         /* check the acl against the required access mask */
 614         status = sec_access_check(sd, token, *access_mask, access_mask);
 615
 616         if (pvfs->ntvfs->ctx->protocol != PROTOCOL_SMB2) {
 617                 /* on SMB, this bit is always granted, even if not
 618                    asked for */
 619                 *access_mask |= SEC_FILE_READ_ATTRIBUTE;
 620         }
 621
 622         talloc_free(acl);
 623
 624         return status;
 625 }
 626
 627
 628 /*
 629   a simplified interface to access check, designed for calls that
 630   do not take or return an access check mask
 631 */
 632 NTSTATUS pvfs_access_check_simple(struct pvfs_state *pvfs,
 633                                   struct ntvfs_request *req,
 634                                   struct pvfs_filename *name,
 635                                   uint32_t access_needed)
 636 {
 637         if (access_needed == 0) {
 638                 return NT_STATUS_OK;
 639         }
 640         return pvfs_access_check(pvfs, req, name, &access_needed);
 641 }
 642
 643 /*
 644   access check for creating a new file/directory
 645 */
 646 NTSTATUS pvfs_access_check_create(struct pvfs_state *pvfs,
 647                                   struct ntvfs_request *req,
 648                                   struct pvfs_filename *name,
 649                                   uint32_t *access_mask,
 650                                   bool container,
 651                                   struct security_descriptor **sd)
 652 {
 653         struct pvfs_filename *parent;
 654         NTSTATUS status;
 655
 656         if (pvfs_read_only(pvfs, *access_mask)) {
 657                 return NT_STATUS_ACCESS_DENIED;
 658         }
 659
 660         status = pvfs_resolve_parent(pvfs, req, name, &parent);
 661         NT_STATUS_NOT_OK_RETURN(status);
 662
 663         status = pvfs_access_check_simple(pvfs, req, parent, SEC_DIR_ADD_FILE);
 664         NT_STATUS_NOT_OK_RETURN(status);
 665
 666         if (*sd == NULL) {
 667                 status = pvfs_acl_inherited_sd(pvfs, req, req, parent, container, sd);
 668         }
 669
 670         talloc_free(parent);
 671         if (!NT_STATUS_IS_OK(status)) {
 672                 return status;
 673         }
 674
 675         /* expand the generic access bits to file specific bits */
 676         *access_mask = pvfs_translate_mask(*access_mask);
 677
 678         if (*access_mask & SEC_FLAG_MAXIMUM_ALLOWED) {
 679                 *access_mask |= SEC_RIGHTS_FILE_ALL;
 680                 *access_mask &= ~SEC_FLAG_MAXIMUM_ALLOWED;
 681         }
 682
 683         if (pvfs->ntvfs->ctx->protocol != PROTOCOL_SMB2) {
 684                 /* on SMB, this bit is always granted, even if not
 685                    asked for */
 686                 *access_mask |= SEC_FILE_READ_ATTRIBUTE;
 687         }
 688
 689         return NT_STATUS_OK;
 690 }
 691
 692 /*
 693   access check for creating a new file/directory - no access mask supplied
 694 */
 695 NTSTATUS pvfs_access_check_parent(struct pvfs_state *pvfs,
 696                                   struct ntvfs_request *req,
 697                                   struct pvfs_filename *name,
 698                                   uint32_t access_mask)
 699 {
 700         struct pvfs_filename *parent;
 701         NTSTATUS status;
 702
 703         status = pvfs_resolve_parent(pvfs, req, name, &parent);
 704         if (!NT_STATUS_IS_OK(status)) {
 705                 return status;
 706         }
 707
 708         return pvfs_access_check_simple(pvfs, req, parent, access_mask);
 709 }
 710
 711
 712 /*
 713   determine if an ACE is inheritable
 714 */
 715 static bool pvfs_inheritable_ace(struct pvfs_state *pvfs,
 716                                  const struct security_ace *ace,
 717                                  bool container)
 718 {
 719         if (!container) {
 720                 return (ace->flags & SEC_ACE_FLAG_OBJECT_INHERIT) != 0;
 721         }
 722
 723         if (ace->flags & SEC_ACE_FLAG_CONTAINER_INHERIT) {
 724                 return true;
 725         }
 726
 727         if ((ace->flags & SEC_ACE_FLAG_OBJECT_INHERIT) &&
 728             !(ace->flags & SEC_ACE_FLAG_NO_PROPAGATE_INHERIT)) {
 729                 return true;
 730         }
 731
 732         return false;
 733 }
 734
 735 /*
 736   this is the core of ACL inheritance. It copies any inheritable
 737   aces from the parent SD to the child SD. Note that the algorithm
 738   depends on whether the child is a container or not
 739 */
 740 static NTSTATUS pvfs_acl_inherit_aces(struct pvfs_state *pvfs,
 741                                       struct security_descriptor *parent_sd,
 742                                       struct security_descriptor *sd,
 743                                       bool container)
 744 {
 745         int i;
 746
 747         for (i=0;i<parent_sd->dacl->num_aces;i++) {
 748                 struct security_ace ace = parent_sd->dacl->aces[i];
 749                 NTSTATUS status;
 750                 const struct dom_sid *creator = NULL, *new_id = NULL;
 751                 uint32_t orig_flags;
 752
 753                 if (!pvfs_inheritable_ace(pvfs, &ace, container)) {
 754                         continue;
 755                 }
 756
 757                 orig_flags = ace.flags;
 758
 759                 /* see the RAW-ACLS inheritance test for details on these rules */
 760                 if (!container) {
 761                         ace.flags = 0;
 762                 } else {
 763                         ace.flags &= ~SEC_ACE_FLAG_INHERIT_ONLY;
 764
 765                         if (!(ace.flags & SEC_ACE_FLAG_CONTAINER_INHERIT)) {
 766                                 ace.flags |= SEC_ACE_FLAG_INHERIT_ONLY;
 767                         }
 768                         if (ace.flags & SEC_ACE_FLAG_NO_PROPAGATE_INHERIT) {
 769                                 ace.flags = 0;
 770                         }
 771                 }
 772
 773                 /* the CREATOR sids are special when inherited */
 774                 if (dom_sid_equal(&ace.trustee, pvfs->sid_cache.creator_owner)) {
 775                         creator = pvfs->sid_cache.creator_owner;
 776                         new_id = sd->owner_sid;
 777                 } else if (dom_sid_equal(&ace.trustee, pvfs->sid_cache.creator_group)) {
 778                         creator = pvfs->sid_cache.creator_group;
 779                         new_id = sd->group_sid;
 780                 } else {
 781                         new_id = &ace.trustee;
 782                 }
 783
 784                 if (creator && container &&
 785                     (ace.flags & SEC_ACE_FLAG_CONTAINER_INHERIT)) {
 786                         uint32_t flags = ace.flags;
 787
 788                         ace.trustee = *new_id;
 789                         ace.flags = 0;
 790                         status = security_descriptor_dacl_add(sd, &ace);
 791                         if (!NT_STATUS_IS_OK(status)) {
 792                                 return status;
 793                         }
 794
 795                         ace.trustee = *creator;
 796                         ace.flags = flags | SEC_ACE_FLAG_INHERIT_ONLY;
 797                         status = security_descriptor_dacl_add(sd, &ace);
 798                 } else if (container &&
 799                            !(orig_flags & SEC_ACE_FLAG_NO_PROPAGATE_INHERIT)) {
 800                         status = security_descriptor_dacl_add(sd, &ace);
 801                 } else {
 802                         ace.trustee = *new_id;
 803                         status = security_descriptor_dacl_add(sd, &ace);
 804                 }
 805
 806                 if (!NT_STATUS_IS_OK(status)) {
 807                         return status;
 808                 }
 809         }
 810
 811         return NT_STATUS_OK;
 812 }
 813
 814
 815
 816 /*
 817   calculate the ACL on a new file/directory based on the inherited ACL
 818   from the parent. If there is no inherited ACL then return a NULL
 819   ACL, which means the default ACL should be used
 820 */
 821 NTSTATUS pvfs_acl_inherited_sd(struct pvfs_state *pvfs,
 822                                TALLOC_CTX *mem_ctx,
 823                                struct ntvfs_request *req,
 824                                struct pvfs_filename *parent,
 825                                bool container,
 826                                struct security_descriptor **ret_sd)
 827 {
 828         struct xattr_NTACL *acl;
 829         NTSTATUS status;
 830         struct security_descriptor *parent_sd, *sd;
 831         struct id_mapping *ids;
 832         struct composite_context *ctx;
 833         TALLOC_CTX *tmp_ctx = talloc_new(mem_ctx);
 834
 835         *ret_sd = NULL;
 836
 837         acl = talloc(req, struct xattr_NTACL);
 838         NT_STATUS_HAVE_NO_MEMORY_AND_FREE(acl, tmp_ctx);
 839
 840         status = pvfs_acl_load(pvfs, parent, -1, acl);
 841         if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
 842                 talloc_free(tmp_ctx);
 843                 return NT_STATUS_OK;
 844         }
 845         NT_STATUS_NOT_OK_RETURN_AND_FREE(status, tmp_ctx);
 846
 847         switch (acl->version) {
 848         case 1:
 849                 parent_sd = acl->info.sd;
 850                 break;
 851         default:
 852                 talloc_free(tmp_ctx);
 853                 return NT_STATUS_INVALID_ACL;
 854         }
 855
 856         if (parent_sd == NULL ||
 857             parent_sd->dacl == NULL ||
 858             parent_sd->dacl->num_aces == 0) {
 859                 /* go with the default ACL */
 860                 talloc_free(tmp_ctx);
 861                 return NT_STATUS_OK;
 862         }
 863
 864         /* create the new sd */
 865         sd = security_descriptor_initialise(req);
 866         NT_STATUS_HAVE_NO_MEMORY_AND_FREE(sd, tmp_ctx);
 867
 868         ids = talloc_array(sd, struct id_mapping, 2);
 869         NT_STATUS_HAVE_NO_MEMORY_AND_FREE(ids, tmp_ctx);
 870
 871         ids[0].unixid = talloc(ids, struct unixid);
 872         NT_STATUS_HAVE_NO_MEMORY_AND_FREE(ids[0].unixid, tmp_ctx);
 873         ids[0].unixid->id = geteuid();
 874         ids[0].unixid->type = ID_TYPE_UID;
 875         ids[0].sid = NULL;
 876         ids[0].status = NT_STATUS_NONE_MAPPED;
 877
 878         ids[1].unixid = talloc(ids, struct unixid);
 879         NT_STATUS_HAVE_NO_MEMORY_AND_FREE(ids[1].unixid, tmp_ctx);
 880         ids[1].unixid->id = getegid();
 881         ids[1].unixid->type = ID_TYPE_GID;
 882         ids[1].sid = NULL;
 883         ids[1].status = NT_STATUS_NONE_MAPPED;
 884
 885         ctx = wbc_xids_to_sids_send(pvfs->wbc_ctx, ids, 2, ids);
 886         NT_STATUS_HAVE_NO_MEMORY_AND_FREE(ctx, tmp_ctx);
 887
 888         status = wbc_xids_to_sids_recv(ctx, &ids);
 889         NT_STATUS_NOT_OK_RETURN_AND_FREE(status, tmp_ctx);
 890
 891         sd->owner_sid = talloc_steal(sd, ids[0].sid);
 892         sd->group_sid = talloc_steal(sd, ids[1].sid);
 893
 894         sd->type |= SEC_DESC_DACL_PRESENT;
 895
 896         /* fill in the aces from the parent */
 897         status = pvfs_acl_inherit_aces(pvfs, parent_sd, sd, container);
 898         NT_STATUS_NOT_OK_RETURN_AND_FREE(status, tmp_ctx);
 899
 900         /* if there is nothing to inherit then we fallback to the
 901            default acl */
 902         if (sd->dacl == NULL || sd->dacl->num_aces == 0) {
 903                 talloc_free(tmp_ctx);
 904                 return NT_STATUS_OK;
 905         }
 906
 907         *ret_sd = talloc_steal(mem_ctx, sd);
 908
 909         talloc_free(tmp_ctx);
 910         return NT_STATUS_OK;
 911 }
 912
 913
 914 /*
 915   setup an ACL on a new file/directory based on the inherited ACL from
 916   the parent. If there is no inherited ACL then we don't set anything,
 917   as the default ACL applies anyway
 918 */
 919 NTSTATUS pvfs_acl_inherit(struct pvfs_state *pvfs,
 920                           struct ntvfs_request *req,
 921                           struct pvfs_filename *name,
 922                           int fd)
 923 {
 924         struct xattr_NTACL acl;
 925         NTSTATUS status;
 926         struct security_descriptor *sd;
 927         struct pvfs_filename *parent;
 928         bool container;
 929
 930         /* form the parents path */
 931         status = pvfs_resolve_parent(pvfs, req, name, &parent);
 932         NT_STATUS_NOT_OK_RETURN(status);
 933
 934         container = (name->dos.attrib & FILE_ATTRIBUTE_DIRECTORY) ? true:false;
 935
 936         status = pvfs_acl_inherited_sd(pvfs, req, req, parent, container, &sd);
 937         if (!NT_STATUS_IS_OK(status)) {
 938                 talloc_free(parent);
 939                 return status;
 940         }
 941
 942         if (sd == NULL) {
 943                 return NT_STATUS_OK;
 944         }
 945
 946         acl.version = 1;
 947         acl.info.sd = sd;
 948
 949         status = pvfs_acl_save(pvfs, name, fd, &acl);
 950         talloc_free(sd);
 951         talloc_free(parent);
 952
 953         return status;
 954 }
 955
 956 /*
 957   return the maximum allowed access mask
 958 */
 959 NTSTATUS pvfs_access_maximal_allowed(struct pvfs_state *pvfs,
 960                                      struct ntvfs_request *req,
 961                                      struct pvfs_filename *name,
 962                                      uint32_t *maximal_access)
 963 {
 964         *maximal_access = SEC_FLAG_MAXIMUM_ALLOWED;
 965         return pvfs_access_check(pvfs, req, name, maximal_access);
 966 }