source3/modules/vfs_acl_common.c

   1 /*
   2  * Store Windows ACLs in data store - common functions.
   3  * #included into modules/vfs_acl_xattr.c and modules/vfs_acl_tdb.c
   4  *
   5  * Copyright (C) Volker Lendecke, 2008
   6  * Copyright (C) Jeremy Allison, 2009
   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 "smbd/smbd.h"
  23 #include "system/filesys.h"
  24 #include "../libcli/security/security.h"
  25 #include "../librpc/gen_ndr/ndr_security.h"
  26 #include "../lib/util/bitmap.h"
  27
  28 static NTSTATUS create_acl_blob(const struct security_descriptor *psd,
  29                         DATA_BLOB *pblob,
  30                         uint16_t hash_type,
  31                         uint8_t hash[XATTR_SD_HASH_SIZE]);
  32
  33 static NTSTATUS get_acl_blob(TALLOC_CTX *ctx,
  34                         vfs_handle_struct *handle,
  35                         files_struct *fsp,
  36                         const char *name,
  37                         DATA_BLOB *pblob);
  38
  39 static NTSTATUS store_acl_blob_fsp(vfs_handle_struct *handle,
  40                         files_struct *fsp,
  41                         DATA_BLOB *pblob);
  42
  43 #define HASH_SECURITY_INFO (SECINFO_OWNER | \
  44                                 SECINFO_GROUP | \
  45                                 SECINFO_DACL | \
  46                                 SECINFO_SACL)
  47
  48 /*******************************************************************
  49  Hash a security descriptor.
  50 *******************************************************************/
  51
  52 static NTSTATUS hash_blob_sha256(DATA_BLOB blob,
  53                                  uint8_t *hash)
  54 {
  55         SHA256_CTX tctx;
  56
  57         memset(hash, '\0', XATTR_SD_HASH_SIZE);
  58
  59         samba_SHA256_Init(&tctx);
  60         samba_SHA256_Update(&tctx, blob.data, blob.length);
  61         samba_SHA256_Final(hash, &tctx);
  62
  63         return NT_STATUS_OK;
  64 }
  65
  66 /*******************************************************************
  67  Hash a security descriptor.
  68 *******************************************************************/
  69
  70 static NTSTATUS hash_sd_sha256(struct security_descriptor *psd,
  71                         uint8_t *hash)
  72 {
  73         DATA_BLOB blob;
  74         NTSTATUS status;
  75
  76         memset(hash, '\0', XATTR_SD_HASH_SIZE);
  77         status = create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash);
  78         if (!NT_STATUS_IS_OK(status)) {
  79                 return status;
  80         }
  81         return hash_blob_sha256(blob, hash);
  82 }
  83
  84 /*******************************************************************
  85  Parse out a struct security_descriptor from a DATA_BLOB.
  86 *******************************************************************/
  87
  88 static NTSTATUS parse_acl_blob(const DATA_BLOB *pblob,
  89                                TALLOC_CTX *mem_ctx,
  90                                struct security_descriptor **ppdesc,
  91                                uint16_t *p_hash_type,
  92                                uint16_t *p_version,
  93                                uint8_t hash[XATTR_SD_HASH_SIZE],
  94                                uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE])
  95 {
  96         struct xattr_NTACL xacl;
  97         enum ndr_err_code ndr_err;
  98         size_t sd_size;
  99         TALLOC_CTX *frame = talloc_stackframe();
 100
 101         ndr_err = ndr_pull_struct_blob(pblob, frame, &xacl,
 102                         (ndr_pull_flags_fn_t)ndr_pull_xattr_NTACL);
 103
 104         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 105                 DEBUG(5, ("parse_acl_blob: ndr_pull_xattr_NTACL failed: %s\n",
 106                         ndr_errstr(ndr_err)));
 107                 TALLOC_FREE(frame);
 108                 return ndr_map_error2ntstatus(ndr_err);
 109         }
 110
 111         *p_version = xacl.version;
 112
 113         switch (xacl.version) {
 114                 case 1:
 115                         *ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
 116                                         xacl.info.sd->type | SEC_DESC_SELF_RELATIVE,
 117                                         xacl.info.sd->owner_sid,
 118                                         xacl.info.sd->group_sid,
 119                                         xacl.info.sd->sacl,
 120                                         xacl.info.sd->dacl,
 121                                         &sd_size);
 122                         /* No hash - null out. */
 123                         *p_hash_type = XATTR_SD_HASH_TYPE_NONE;
 124                         memset(hash, '\0', XATTR_SD_HASH_SIZE);
 125                         break;
 126                 case 2:
 127                         *ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
 128                                         xacl.info.sd_hs2->sd->type | SEC_DESC_SELF_RELATIVE,
 129                                         xacl.info.sd_hs2->sd->owner_sid,
 130                                         xacl.info.sd_hs2->sd->group_sid,
 131                                         xacl.info.sd_hs2->sd->sacl,
 132                                         xacl.info.sd_hs2->sd->dacl,
 133                                         &sd_size);
 134                         /* No hash - null out. */
 135                         *p_hash_type = XATTR_SD_HASH_TYPE_NONE;
 136                         memset(hash, '\0', XATTR_SD_HASH_SIZE);
 137                         break;
 138                 case 3:
 139                         *ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
 140                                         xacl.info.sd_hs3->sd->type | SEC_DESC_SELF_RELATIVE,
 141                                         xacl.info.sd_hs3->sd->owner_sid,
 142                                         xacl.info.sd_hs3->sd->group_sid,
 143                                         xacl.info.sd_hs3->sd->sacl,
 144                                         xacl.info.sd_hs3->sd->dacl,
 145                                         &sd_size);
 146                         *p_hash_type = xacl.info.sd_hs3->hash_type;
 147                         /* Current version 3 (if no sys acl hash available). */
 148                         memcpy(hash, xacl.info.sd_hs3->hash, XATTR_SD_HASH_SIZE);
 149                         break;
 150                 case 4:
 151                         *ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
 152                                         xacl.info.sd_hs4->sd->type | SEC_DESC_SELF_RELATIVE,
 153                                         xacl.info.sd_hs4->sd->owner_sid,
 154                                         xacl.info.sd_hs4->sd->group_sid,
 155                                         xacl.info.sd_hs4->sd->sacl,
 156                                         xacl.info.sd_hs4->sd->dacl,
 157                                         &sd_size);
 158                         *p_hash_type = xacl.info.sd_hs4->hash_type;
 159                         /* Current version 4. */
 160                         memcpy(hash, xacl.info.sd_hs4->hash, XATTR_SD_HASH_SIZE);
 161                         memcpy(sys_acl_hash, xacl.info.sd_hs4->sys_acl_hash, XATTR_SD_HASH_SIZE);
 162                         break;
 163                 default:
 164                         TALLOC_FREE(frame);
 165                         return NT_STATUS_REVISION_MISMATCH;
 166         }
 167
 168         TALLOC_FREE(frame);
 169
 170         return (*ppdesc != NULL) ? NT_STATUS_OK : NT_STATUS_NO_MEMORY;
 171 }
 172
 173 /*******************************************************************
 174  Create a DATA_BLOB from a hash of the security descriptor storead at
 175  the system layer and the NT ACL we wish to preserve
 176 *******************************************************************/
 177
 178 static NTSTATUS create_acl_blob(const struct security_descriptor *psd,
 179                         DATA_BLOB *pblob,
 180                         uint16_t hash_type,
 181                         uint8_t hash[XATTR_SD_HASH_SIZE])
 182 {
 183         struct xattr_NTACL xacl;
 184         struct security_descriptor_hash_v3 sd_hs3;
 185         enum ndr_err_code ndr_err;
 186         TALLOC_CTX *ctx = talloc_tos();
 187
 188         ZERO_STRUCT(xacl);
 189         ZERO_STRUCT(sd_hs3);
 190
 191         xacl.version = 3;
 192         xacl.info.sd_hs3 = &sd_hs3;
 193         xacl.info.sd_hs3->sd = discard_const_p(struct security_descriptor, psd);
 194         xacl.info.sd_hs3->hash_type = hash_type;
 195         memcpy(&xacl.info.sd_hs3->hash[0], hash, XATTR_SD_HASH_SIZE);
 196
 197         ndr_err = ndr_push_struct_blob(
 198                         pblob, ctx, &xacl,
 199                         (ndr_push_flags_fn_t)ndr_push_xattr_NTACL);
 200
 201         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 202                 DEBUG(5, ("create_acl_blob: ndr_push_xattr_NTACL failed: %s\n",
 203                         ndr_errstr(ndr_err)));
 204                 return ndr_map_error2ntstatus(ndr_err);
 205         }
 206
 207         return NT_STATUS_OK;
 208 }
 209
 210 /*******************************************************************
 211  Create a DATA_BLOB from a hash of the security descriptors
 212  (system and NT) stored at the system layer and the NT ACL we wish
 213  to preserve.
 214 *******************************************************************/
 215
 216 static NTSTATUS create_sys_acl_blob(const struct security_descriptor *psd,
 217                                     DATA_BLOB *pblob,
 218                                     uint16_t hash_type,
 219                                     uint8_t hash[XATTR_SD_HASH_SIZE],
 220                                     const char *description,
 221                                     uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE])
 222 {
 223         struct xattr_NTACL xacl;
 224         struct security_descriptor_hash_v4 sd_hs4;
 225         enum ndr_err_code ndr_err;
 226         TALLOC_CTX *ctx = talloc_tos();
 227         NTTIME nttime_now;
 228         struct timeval now = timeval_current();
 229         nttime_now = timeval_to_nttime(&now);
 230
 231         ZERO_STRUCT(xacl);
 232         ZERO_STRUCT(sd_hs4);
 233
 234         xacl.version = 4;
 235         xacl.info.sd_hs4 = &sd_hs4;
 236         xacl.info.sd_hs4->sd = discard_const_p(struct security_descriptor, psd);
 237         xacl.info.sd_hs4->hash_type = hash_type;
 238         memcpy(&xacl.info.sd_hs4->hash[0], hash, XATTR_SD_HASH_SIZE);
 239         xacl.info.sd_hs4->description = description;
 240         xacl.info.sd_hs4->time = nttime_now;
 241         memcpy(&xacl.info.sd_hs4->sys_acl_hash[0], sys_acl_hash, XATTR_SD_HASH_SIZE);
 242
 243         ndr_err = ndr_push_struct_blob(
 244                         pblob, ctx, &xacl,
 245                         (ndr_push_flags_fn_t)ndr_push_xattr_NTACL);
 246
 247         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 248                 DEBUG(5, ("create_acl_blob: ndr_push_xattr_NTACL failed: %s\n",
 249                         ndr_errstr(ndr_err)));
 250                 return ndr_map_error2ntstatus(ndr_err);
 251         }
 252
 253         return NT_STATUS_OK;
 254 }
 255
 256 /*******************************************************************
 257  Add in 3 inheritable components for a non-inheritable directory ACL.
 258  CREATOR_OWNER/CREATOR_GROUP/WORLD.
 259 *******************************************************************/
 260
 261 static NTSTATUS add_directory_inheritable_components(vfs_handle_struct *handle,
 262                                 const char *name,
 263                                 SMB_STRUCT_STAT *psbuf,
 264                                 struct security_descriptor *psd)
 265 {
 266         struct connection_struct *conn = handle->conn;
 267         int num_aces = (psd->dacl ? psd->dacl->num_aces : 0);
 268         struct smb_filename smb_fname;
 269         enum security_ace_type acltype;
 270         uint32_t access_mask;
 271         mode_t dir_mode;
 272         mode_t file_mode;
 273         mode_t mode;
 274         struct security_ace *new_ace_list;
 275
 276         if (psd->dacl) {
 277                 new_ace_list = talloc_zero_array(psd->dacl,
 278                                                  struct security_ace,
 279                                                  num_aces + 3);
 280         } else {
 281                 /*
 282                  * make_sec_acl() at the bottom of this function
 283                  * dupliates new_ace_list
 284                  */
 285                 new_ace_list = talloc_zero_array(talloc_tos(),
 286                                                  struct security_ace,
 287                                                  num_aces + 3);
 288         }
 289
 290         if (new_ace_list == NULL) {
 291                 return NT_STATUS_NO_MEMORY;
 292         }
 293
 294         /* Fake a quick smb_filename. */
 295         ZERO_STRUCT(smb_fname);
 296         smb_fname.st = *psbuf;
 297         smb_fname.base_name = discard_const_p(char, name);
 298
 299         dir_mode = unix_mode(conn,
 300                         FILE_ATTRIBUTE_DIRECTORY, &smb_fname, NULL);
 301         file_mode = unix_mode(conn,
 302                         FILE_ATTRIBUTE_ARCHIVE, &smb_fname, NULL);
 303
 304         mode = dir_mode | file_mode;
 305
 306         DEBUG(10, ("add_directory_inheritable_components: directory %s, "
 307                 "mode = 0%o\n",
 308                 name,
 309                 (unsigned int)mode ));
 310
 311         if (num_aces) {
 312                 memcpy(new_ace_list, psd->dacl->aces,
 313                         num_aces * sizeof(struct security_ace));
 314         }
 315         access_mask = map_canon_ace_perms(SNUM(conn), &acltype,
 316                                 mode & 0700, false);
 317
 318         init_sec_ace(&new_ace_list[num_aces],
 319                         &global_sid_Creator_Owner,
 320                         acltype,
 321                         access_mask,
 322                         SEC_ACE_FLAG_CONTAINER_INHERIT|
 323                                 SEC_ACE_FLAG_OBJECT_INHERIT|
 324                                 SEC_ACE_FLAG_INHERIT_ONLY);
 325         access_mask = map_canon_ace_perms(SNUM(conn), &acltype,
 326                                 (mode << 3) & 0700, false);
 327         init_sec_ace(&new_ace_list[num_aces+1],
 328                         &global_sid_Creator_Group,
 329                         acltype,
 330                         access_mask,
 331                         SEC_ACE_FLAG_CONTAINER_INHERIT|
 332                                 SEC_ACE_FLAG_OBJECT_INHERIT|
 333                                 SEC_ACE_FLAG_INHERIT_ONLY);
 334         access_mask = map_canon_ace_perms(SNUM(conn), &acltype,
 335                                 (mode << 6) & 0700, false);
 336         init_sec_ace(&new_ace_list[num_aces+2],
 337                         &global_sid_World,
 338                         acltype,
 339                         access_mask,
 340                         SEC_ACE_FLAG_CONTAINER_INHERIT|
 341                                 SEC_ACE_FLAG_OBJECT_INHERIT|
 342                                 SEC_ACE_FLAG_INHERIT_ONLY);
 343         if (psd->dacl) {
 344                 psd->dacl->aces = new_ace_list;
 345                 psd->dacl->num_aces += 3;
 346                 psd->dacl->size += new_ace_list[num_aces].size +
 347                         new_ace_list[num_aces+1].size +
 348                         new_ace_list[num_aces+2].size;
 349         } else {
 350                 psd->dacl = make_sec_acl(psd,
 351                                 NT4_ACL_REVISION,
 352                                 3,
 353                                 new_ace_list);
 354                 if (psd->dacl == NULL) {
 355                         return NT_STATUS_NO_MEMORY;
 356                 }
 357         }
 358         return NT_STATUS_OK;
 359 }
 360
 361 /*******************************************************************
 362  Pull a DATA_BLOB from an xattr given a pathname.
 363  If the hash doesn't match, or doesn't exist - return the underlying
 364  filesystem sd.
 365 *******************************************************************/
 366
 367 static NTSTATUS get_nt_acl_internal(vfs_handle_struct *handle,
 368                                     files_struct *fsp,
 369                                     const char *name,
 370                                     uint32_t security_info,
 371                                     TALLOC_CTX *mem_ctx,
 372                                     struct security_descriptor **ppdesc)
 373 {
 374         DATA_BLOB blob = data_blob_null;
 375         NTSTATUS status;
 376         uint16_t hash_type = XATTR_SD_HASH_TYPE_NONE;
 377         uint16_t xattr_version = 0;
 378         uint8_t hash[XATTR_SD_HASH_SIZE];
 379         uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE];
 380         uint8_t hash_tmp[XATTR_SD_HASH_SIZE];
 381         uint8_t sys_acl_hash_tmp[XATTR_SD_HASH_SIZE];
 382         struct security_descriptor *psd = NULL;
 383         struct security_descriptor *pdesc_next = NULL;
 384         bool ignore_file_system_acl = lp_parm_bool(SNUM(handle->conn),
 385                                                 ACL_MODULE_NAME,
 386                                                 "ignore system acls",
 387                                                 false);
 388         TALLOC_CTX *frame = talloc_stackframe();
 389
 390         if (fsp && name == NULL) {
 391                 name = fsp->fsp_name->base_name;
 392         }
 393
 394         DEBUG(10, ("get_nt_acl_internal: name=%s\n", name));
 395
 396         status = get_acl_blob(frame, handle, fsp, name, &blob);
 397         if (!NT_STATUS_IS_OK(status)) {
 398                 DEBUG(10, ("get_nt_acl_internal: get_acl_blob returned %s\n",
 399                         nt_errstr(status)));
 400                 psd = NULL;
 401                 goto out;
 402         } else {
 403                 status = parse_acl_blob(&blob, mem_ctx, &psd,
 404                                         &hash_type, &xattr_version, &hash[0], &sys_acl_hash[0]);
 405                 if (!NT_STATUS_IS_OK(status)) {
 406                         DEBUG(10, ("parse_acl_blob returned %s\n",
 407                                    nt_errstr(status)));
 408                         psd = NULL;
 409                         goto out;
 410                 }
 411         }
 412
 413         /* Ensure we don't leak psd if we don't choose it.
 414          *
 415          * We don't allocate it onto frame as it is preferred not to
 416          * steal from a talloc pool.
 417          */
 418         talloc_steal(frame, psd);
 419
 420         /* determine which type of xattr we got */
 421         switch (xattr_version) {
 422         case 1:
 423         case 2:
 424                 /* These xattr types are unilatteral, they do not
 425                  * require confirmation of the hash.  In particular,
 426                  * the NTVFS file server uses version 1, but
 427                  * 'samba-tool ntacl' can set these as well */
 428                 goto out;
 429         case 3:
 430         case 4:
 431                 if (ignore_file_system_acl) {
 432                         goto out;
 433                 }
 434
 435                 break;
 436         default:
 437                 DEBUG(10, ("get_nt_acl_internal: ACL blob revision "
 438                            "mismatch (%u) for file %s\n",
 439                            (unsigned int)hash_type,
 440                            name));
 441                 TALLOC_FREE(psd);
 442                 psd = NULL;
 443                 goto out;
 444         }
 445
 446         /* determine which type of xattr we got */
 447         if (hash_type != XATTR_SD_HASH_TYPE_SHA256) {
 448                 DEBUG(10, ("get_nt_acl_internal: ACL blob hash type "
 449                            "(%u) unexpected for file %s\n",
 450                            (unsigned int)hash_type,
 451                            name));
 452                 TALLOC_FREE(psd);
 453                 psd = NULL;
 454                 goto out;
 455         }
 456
 457         /* determine which type of xattr we got */
 458         switch (xattr_version) {
 459         case 4:
 460         {
 461                 int ret;
 462                 char *sys_acl_blob_description;
 463                 DATA_BLOB sys_acl_blob;
 464                 if (fsp) {
 465                         /* Get the full underlying sd, then hash. */
 466                         ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FD(handle,
 467                                                                fsp,
 468                                                                frame,
 469                                                                &sys_acl_blob_description,
 470                                                                &sys_acl_blob);
 471                 } else {
 472                         /* Get the full underlying sd, then hash. */
 473                         ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FILE(handle,
 474                                                                  name,
 475                                                                  frame,
 476                                                                  &sys_acl_blob_description,
 477                                                                  &sys_acl_blob);
 478                 }
 479
 480                 /* If we fail to get the ACL blob (for some reason) then this
 481                  * is not fatal, we just work based on the NT ACL only */
 482                 if (ret == 0) {
 483                         status = hash_blob_sha256(sys_acl_blob, sys_acl_hash_tmp);
 484                         if (!NT_STATUS_IS_OK(status)) {
 485                                 TALLOC_FREE(frame);
 486                                 return status;
 487                         }
 488
 489                         if (memcmp(&sys_acl_hash[0], &sys_acl_hash_tmp[0],
 490                                    XATTR_SD_HASH_SIZE) == 0) {
 491                                 /* Hash matches, return blob sd. */
 492                                 DEBUG(10, ("get_nt_acl_internal: blob hash "
 493                                            "matches for file %s\n",
 494                                            name ));
 495                                 goto out;
 496                         }
 497                 }
 498
 499                 /* Otherwise, fall though and see if the NT ACL hash matches */
 500         }
 501         case 3:
 502                 /* Get the full underlying sd for the hash
 503                    or to return as backup. */
 504                 if (fsp) {
 505                         status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
 506                                                           fsp,
 507                                                           HASH_SECURITY_INFO,
 508                                                           mem_ctx,
 509                                                           &pdesc_next);
 510                 } else {
 511                         status = SMB_VFS_NEXT_GET_NT_ACL(handle,
 512                                                          name,
 513                                                          HASH_SECURITY_INFO,
 514                                                          mem_ctx,
 515                                                          &pdesc_next);
 516                 }
 517
 518                 if (!NT_STATUS_IS_OK(status)) {
 519                         DEBUG(10, ("get_nt_acl_internal: get_next_acl for file %s "
 520                                    "returned %s\n",
 521                                    name,
 522                                    nt_errstr(status)));
 523                         TALLOC_FREE(frame);
 524                         return status;
 525                 }
 526
 527                 /* Ensure we don't leak psd_next if we don't choose it.
 528                  *
 529                  * We don't allocate it onto frame as it is preferred not to
 530                  * steal from a talloc pool.
 531                  */
 532                 talloc_steal(frame, pdesc_next);
 533
 534                 status = hash_sd_sha256(pdesc_next, hash_tmp);
 535                 if (!NT_STATUS_IS_OK(status)) {
 536                         TALLOC_FREE(psd);
 537                         psd = pdesc_next;
 538                         goto out;
 539                 }
 540
 541                 if (memcmp(&hash[0], &hash_tmp[0], XATTR_SD_HASH_SIZE) == 0) {
 542                         /* Hash matches, return blob sd. */
 543                         DEBUG(10, ("get_nt_acl_internal: blob hash "
 544                                    "matches for file %s\n",
 545                                    name ));
 546                         goto out;
 547                 }
 548
 549                 /* Hash doesn't match, return underlying sd. */
 550                 DEBUG(10, ("get_nt_acl_internal: blob hash "
 551                            "does not match for file %s - returning "
 552                            "file system SD mapping.\n",
 553                            name ));
 554
 555                 if (DEBUGLEVEL >= 10) {
 556                         DEBUG(10,("get_nt_acl_internal: acl for blob hash for %s is:\n",
 557                                   name ));
 558                         NDR_PRINT_DEBUG(security_descriptor, pdesc_next);
 559                 }
 560
 561                 TALLOC_FREE(psd);
 562                 psd = pdesc_next;
 563         }
 564   out:
 565
 566         if (psd == NULL) {
 567                 /* Get the full underlying sd, as we failed to get the
 568                  * blob for the hash, or the revision/hash type wasn't
 569                  * known */
 570                 if (fsp) {
 571                         status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
 572                                                           fsp,
 573                                                           security_info,
 574                                                           mem_ctx,
 575                                                           &pdesc_next);
 576                 } else {
 577                         status = SMB_VFS_NEXT_GET_NT_ACL(handle,
 578                                                          name,
 579                                                          security_info,
 580                                                          mem_ctx,
 581                                                          &pdesc_next);
 582                 }
 583
 584                 if (!NT_STATUS_IS_OK(status)) {
 585                         DEBUG(10, ("get_nt_acl_internal: get_next_acl for file %s "
 586                                    "returned %s\n",
 587                                    name,
 588                                    nt_errstr(status)));
 589                         TALLOC_FREE(frame);
 590                         return status;
 591                 }
 592
 593                 /* Ensure we don't leak psd_next if we don't choose it.
 594                  *
 595                  * We don't allocate it onto frame as it is preferred not to
 596                  * steal from a talloc pool.
 597                  */
 598                 talloc_steal(frame, pdesc_next);
 599                 psd = pdesc_next;
 600         }
 601
 602         if (psd != pdesc_next) {
 603                 /* We're returning the blob, throw
 604                  * away the filesystem SD. */
 605                 TALLOC_FREE(pdesc_next);
 606         } else {
 607                 SMB_STRUCT_STAT sbuf;
 608                 SMB_STRUCT_STAT *psbuf = &sbuf;
 609                 bool is_directory = false;
 610                 /*
 611                  * We're returning the underlying ACL from the
 612                  * filesystem. If it's a directory, and has no
 613                  * inheritable ACE entries we have to fake them.
 614                  */
 615                 if (fsp) {
 616                         status = vfs_stat_fsp(fsp);
 617                         if (!NT_STATUS_IS_OK(status)) {
 618                                 TALLOC_FREE(frame);
 619                                 return status;
 620                         }
 621                         psbuf = &fsp->fsp_name->st;
 622                 } else {
 623                         int ret = vfs_stat_smb_fname(handle->conn,
 624                                                 name,
 625                                                 &sbuf);
 626                         if (ret == -1) {
 627                                 TALLOC_FREE(frame);
 628                                 return map_nt_error_from_unix(errno);
 629                         }
 630                 }
 631                 is_directory = S_ISDIR(psbuf->st_ex_mode);
 632
 633                 if (ignore_file_system_acl) {
 634                         TALLOC_FREE(pdesc_next);
 635                         status = make_default_filesystem_acl(mem_ctx,
 636                                                 name,
 637                                                 psbuf,
 638                                                 &psd);
 639                         if (!NT_STATUS_IS_OK(status)) {
 640                                 TALLOC_FREE(frame);
 641                                 return status;
 642                         }
 643                 } else {
 644                         if (is_directory &&
 645                                 !sd_has_inheritable_components(psd,
 646                                                         true)) {
 647                                 status = add_directory_inheritable_components(
 648                                                         handle,
 649                                                         name,
 650                                                         psbuf,
 651                                                         psd);
 652                                 if (!NT_STATUS_IS_OK(status)) {
 653                                         TALLOC_FREE(frame);
 654                                         return status;
 655                                 }
 656                         }
 657                         /* The underlying POSIX module always sets
 658                            the ~SEC_DESC_DACL_PROTECTED bit, as ACLs
 659                            can't be inherited in this way under POSIX.
 660                            Remove it for Windows-style ACLs. */
 661                         psd->type &= ~SEC_DESC_DACL_PROTECTED;
 662                 }
 663         }
 664
 665         if (!(security_info & SECINFO_OWNER)) {
 666                 psd->owner_sid = NULL;
 667         }
 668         if (!(security_info & SECINFO_GROUP)) {
 669                 psd->group_sid = NULL;
 670         }
 671         if (!(security_info & SECINFO_DACL)) {
 672                 psd->type &= ~SEC_DESC_DACL_PRESENT;
 673                 psd->dacl = NULL;
 674         }
 675         if (!(security_info & SECINFO_SACL)) {
 676                 psd->type &= ~SEC_DESC_SACL_PRESENT;
 677                 psd->sacl = NULL;
 678         }
 679
 680         TALLOC_FREE(blob.data);
 681
 682         if (DEBUGLEVEL >= 10) {
 683                 DEBUG(10,("get_nt_acl_internal: returning acl for %s is:\n",
 684                         name ));
 685                 NDR_PRINT_DEBUG(security_descriptor, psd);
 686         }
 687
 688         /* The VFS API is that the ACL is expected to be on mem_ctx */
 689         *ppdesc = talloc_move(mem_ctx, &psd);
 690
 691         TALLOC_FREE(frame);
 692         return NT_STATUS_OK;
 693 }
 694
 695 /*********************************************************************
 696  Fetch a security descriptor given an fsp.
 697 *********************************************************************/
 698
 699 static NTSTATUS fget_nt_acl_common(vfs_handle_struct *handle,
 700                                    files_struct *fsp,
 701                                    uint32_t security_info,
 702                                    TALLOC_CTX *mem_ctx,
 703                                    struct security_descriptor **ppdesc)
 704 {
 705         return get_nt_acl_internal(handle, fsp,
 706                                    NULL, security_info, mem_ctx, ppdesc);
 707 }
 708
 709 /*********************************************************************
 710  Fetch a security descriptor given a pathname.
 711 *********************************************************************/
 712
 713 static NTSTATUS get_nt_acl_common(vfs_handle_struct *handle,
 714                                   const char *name,
 715                                   uint32_t security_info,
 716                                   TALLOC_CTX *mem_ctx,
 717                                   struct security_descriptor **ppdesc)
 718 {
 719         return get_nt_acl_internal(handle, NULL,
 720                                    name, security_info, mem_ctx, ppdesc);
 721 }
 722
 723 /*********************************************************************
 724  Store a security descriptor given an fsp.
 725 *********************************************************************/
 726
 727 static NTSTATUS fset_nt_acl_common(vfs_handle_struct *handle, files_struct *fsp,
 728         uint32_t security_info_sent, const struct security_descriptor *orig_psd)
 729 {
 730         NTSTATUS status;
 731         int ret;
 732         DATA_BLOB blob, sys_acl_blob;
 733         struct security_descriptor *pdesc_next = NULL;
 734         struct security_descriptor *psd = NULL;
 735         uint8_t hash[XATTR_SD_HASH_SIZE];
 736         uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE];
 737         bool chown_needed = false;
 738         char *sys_acl_description;
 739         TALLOC_CTX *frame = talloc_stackframe();
 740
 741         if (DEBUGLEVEL >= 10) {
 742                 DEBUG(10,("fset_nt_acl_xattr: incoming sd for file %s\n",
 743                           fsp_str_dbg(fsp)));
 744                 NDR_PRINT_DEBUG(security_descriptor,
 745                         discard_const_p(struct security_descriptor, orig_psd));
 746         }
 747
 748         status = get_nt_acl_internal(handle, fsp,
 749                         NULL,
 750                         SECINFO_OWNER|SECINFO_GROUP|SECINFO_DACL|SECINFO_SACL,
 751                                      frame,
 752                         &psd);
 753
 754         if (!NT_STATUS_IS_OK(status)) {
 755                 TALLOC_FREE(frame);
 756                 return status;
 757         }
 758
 759         psd->revision = orig_psd->revision;
 760         /* All our SD's are self relative. */
 761         psd->type = orig_psd->type | SEC_DESC_SELF_RELATIVE;
 762
 763         if ((security_info_sent & SECINFO_OWNER) && (orig_psd->owner_sid != NULL)) {
 764                 if (!dom_sid_equal(orig_psd->owner_sid, psd->owner_sid)) {
 765                         /* We're changing the owner. */
 766                         chown_needed = true;
 767                 }
 768                 psd->owner_sid = orig_psd->owner_sid;
 769         }
 770         if ((security_info_sent & SECINFO_GROUP) && (orig_psd->group_sid != NULL)) {
 771                 if (!dom_sid_equal(orig_psd->group_sid, psd->group_sid)) {
 772                         /* We're changing the group. */
 773                         chown_needed = true;
 774                 }
 775                 psd->group_sid = orig_psd->group_sid;
 776         }
 777         if (security_info_sent & SECINFO_DACL) {
 778                 if (security_descriptor_with_ms_nfs(orig_psd)) {
 779                         /*
 780                          * If the sd contains a MS NFS SID, do
 781                          * nothing, it's a chmod() request from OS X
 782                          * with AAPL context.
 783                          */
 784                         TALLOC_FREE(frame);
 785                         return NT_STATUS_OK;
 786                 }
 787                 psd->dacl = orig_psd->dacl;
 788                 psd->type |= SEC_DESC_DACL_PRESENT;
 789         }
 790         if (security_info_sent & SECINFO_SACL) {
 791                 psd->sacl = orig_psd->sacl;
 792                 psd->type |= SEC_DESC_SACL_PRESENT;
 793         }
 794
 795         status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp, security_info_sent, psd);
 796         if (!NT_STATUS_IS_OK(status)) {
 797                 if (!NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) {
 798                         TALLOC_FREE(frame);
 799                         return status;
 800                 }
 801                 /* We got access denied here. If we're already root,
 802                    or we didn't need to do a chown, or the fsp isn't
 803                    open with WRITE_OWNER access, just return. */
 804                 if (get_current_uid(handle->conn) == 0 ||
 805                                 chown_needed == false ||
 806                                 !(fsp->access_mask & SEC_STD_WRITE_OWNER)) {
 807                         TALLOC_FREE(frame);
 808                         return NT_STATUS_ACCESS_DENIED;
 809                 }
 810
 811                 DEBUG(10,("fset_nt_acl_common: overriding chown on file %s "
 812                         "for sid %s\n",
 813                         fsp_str_dbg(fsp),
 814                         sid_string_tos(psd->owner_sid)
 815                         ));
 816
 817                 /* Ok, we failed to chown and we have
 818                    SEC_STD_WRITE_OWNER access - override. */
 819                 become_root();
 820                 status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp,
 821                                 security_info_sent, psd);
 822                 unbecome_root();
 823                 if (!NT_STATUS_IS_OK(status)) {
 824                         TALLOC_FREE(frame);
 825                         return status;
 826                 }
 827         }
 828
 829         /* Get the full underlying sd, then hash. */
 830         status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
 831                                           fsp,
 832                                           HASH_SECURITY_INFO,
 833                                           frame,
 834                                           &pdesc_next);
 835
 836         if (!NT_STATUS_IS_OK(status)) {
 837                 TALLOC_FREE(frame);
 838                 return status;
 839         }
 840
 841         status = hash_sd_sha256(pdesc_next, hash);
 842         if (!NT_STATUS_IS_OK(status)) {
 843                 TALLOC_FREE(frame);
 844                 return status;
 845         }
 846
 847         /* Get the full underlying sd, then hash. */
 848         ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FD(handle,
 849                                                fsp,
 850                                                frame,
 851                                                &sys_acl_description,
 852                                                &sys_acl_blob);
 853
 854         /* If we fail to get the ACL blob (for some reason) then this
 855          * is not fatal, we just work based on the NT ACL only */
 856         if (ret != 0) {
 857                 if (DEBUGLEVEL >= 10) {
 858                         DEBUG(10,("fset_nt_acl_xattr: storing xattr sd for file %s\n",
 859                                   fsp_str_dbg(fsp)));
 860                         NDR_PRINT_DEBUG(security_descriptor,
 861                                         discard_const_p(struct security_descriptor, psd));
 862
 863                         DEBUG(10,("fset_nt_acl_xattr: storing has in xattr sd based on \n"));
 864                         NDR_PRINT_DEBUG(security_descriptor,
 865                                         discard_const_p(struct security_descriptor, pdesc_next));
 866                 }
 867                 status = create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash);
 868                 if (!NT_STATUS_IS_OK(status)) {
 869                         DEBUG(10, ("fset_nt_acl_xattr: create_acl_blob failed\n"));
 870                         TALLOC_FREE(frame);
 871                         return status;
 872                 }
 873
 874                 status = store_acl_blob_fsp(handle, fsp, &blob);
 875
 876                 TALLOC_FREE(frame);
 877                 return status;
 878         }
 879
 880         status = hash_blob_sha256(sys_acl_blob, sys_acl_hash);
 881         if (!NT_STATUS_IS_OK(status)) {
 882                 TALLOC_FREE(frame);
 883                 return status;
 884         }
 885
 886         if (DEBUGLEVEL >= 10) {
 887                 DEBUG(10,("fset_nt_acl_xattr: storing xattr sd for file %s based on system ACL\n",
 888                           fsp_str_dbg(fsp)));
 889                 NDR_PRINT_DEBUG(security_descriptor,
 890                                 discard_const_p(struct security_descriptor, psd));
 891
 892                 DEBUG(10,("fset_nt_acl_xattr: storing hash in xattr sd based on system ACL and:\n"));
 893                 NDR_PRINT_DEBUG(security_descriptor,
 894                                 discard_const_p(struct security_descriptor, pdesc_next));
 895         }
 896
 897         /* We store hashes of both the sys ACL blob and the NT
 898          * security desciptor mapped from that ACL so as to improve
 899          * our chances against some inadvertant change breaking the
 900          * hash used */
 901         status = create_sys_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash,
 902                                      sys_acl_description, sys_acl_hash);
 903         if (!NT_STATUS_IS_OK(status)) {
 904                 DEBUG(10, ("fset_nt_acl_xattr: create_sys_acl_blob failed\n"));
 905                 TALLOC_FREE(frame);
 906                 return status;
 907         }
 908
 909         status = store_acl_blob_fsp(handle, fsp, &blob);
 910
 911         TALLOC_FREE(frame);
 912         return status;
 913 }
 914
 915 static int acl_common_remove_object(vfs_handle_struct *handle,
 916                                         const char *path,
 917                                         bool is_directory)
 918 {
 919         connection_struct *conn = handle->conn;
 920         struct file_id id;
 921         files_struct *fsp = NULL;
 922         int ret = 0;
 923         char *parent_dir = NULL;
 924         const char *final_component = NULL;
 925         struct smb_filename local_fname;
 926         int saved_errno = 0;
 927         char *saved_dir = NULL;
 928
 929         saved_dir = vfs_GetWd(talloc_tos(),conn);
 930         if (!saved_dir) {
 931                 saved_errno = errno;
 932                 goto out;
 933         }
 934
 935         if (!parent_dirname(talloc_tos(), path,
 936                         &parent_dir, &final_component)) {
 937                 saved_errno = ENOMEM;
 938                 goto out;
 939         }
 940
 941         DEBUG(10,("acl_common_remove_object: removing %s %s/%s\n",
 942                 is_directory ? "directory" : "file",
 943                 parent_dir, final_component ));
 944
 945         /* cd into the parent dir to pin it. */
 946         ret = vfs_ChDir(conn, parent_dir);
 947         if (ret == -1) {
 948                 saved_errno = errno;
 949                 goto out;
 950         }
 951
 952         ZERO_STRUCT(local_fname);
 953         local_fname.base_name = discard_const_p(char, final_component);
 954
 955         /* Must use lstat here. */
 956         ret = SMB_VFS_LSTAT(conn, &local_fname);
 957         if (ret == -1) {
 958                 saved_errno = errno;
 959                 goto out;
 960         }
 961
 962         /* Ensure we have this file open with DELETE access. */
 963         id = vfs_file_id_from_sbuf(conn, &local_fname.st);
 964         for (fsp = file_find_di_first(conn->sconn, id); fsp;
 965                      fsp = file_find_di_next(fsp)) {
 966                 if (fsp->access_mask & DELETE_ACCESS &&
 967                                 fsp->delete_on_close) {
 968                         /* We did open this for delete,
 969                          * allow the delete as root.
 970                          */
 971                         break;
 972                 }
 973         }
 974
 975         if (!fsp) {
 976                 DEBUG(10,("acl_common_remove_object: %s %s/%s "
 977                         "not an open file\n",
 978                         is_directory ? "directory" : "file",
 979                         parent_dir, final_component ));
 980                 saved_errno = EACCES;
 981                 goto out;
 982         }
 983
 984         become_root();
 985         if (is_directory) {
 986                 ret = SMB_VFS_NEXT_RMDIR(handle, final_component);
 987         } else {
 988                 ret = SMB_VFS_NEXT_UNLINK(handle, &local_fname);
 989         }
 990         unbecome_root();
 991
 992         if (ret == -1) {
 993                 saved_errno = errno;
 994         }
 995
 996   out:
 997
 998         TALLOC_FREE(parent_dir);
 999
1000         if (saved_dir) {
1001                 vfs_ChDir(conn, saved_dir);
1002         }
1003         if (saved_errno) {
1004                 errno = saved_errno;
1005         }
1006         return ret;
1007 }
1008
1009 static int rmdir_acl_common(struct vfs_handle_struct *handle,
1010                                 const char *path)
1011 {
1012         int ret;
1013
1014         /* Try the normal rmdir first. */
1015         ret = SMB_VFS_NEXT_RMDIR(handle, path);
1016         if (ret == 0) {
1017                 return 0;
1018         }
1019         if (errno == EACCES || errno == EPERM) {
1020                 /* Failed due to access denied,
1021                    see if we need to root override. */
1022                 return acl_common_remove_object(handle,
1023                                                 path,
1024                                                 true);
1025         }
1026
1027         DEBUG(10,("rmdir_acl_common: unlink of %s failed %s\n",
1028                 path,
1029                 strerror(errno) ));
1030         return -1;
1031 }
1032
1033 static int unlink_acl_common(struct vfs_handle_struct *handle,
1034                         const struct smb_filename *smb_fname)
1035 {
1036         int ret;
1037
1038         /* Try the normal unlink first. */
1039         ret = SMB_VFS_NEXT_UNLINK(handle, smb_fname);
1040         if (ret == 0) {
1041                 return 0;
1042         }
1043         if (errno == EACCES || errno == EPERM) {
1044                 /* Failed due to access denied,
1045                    see if we need to root override. */
1046
1047                 /* Don't do anything fancy for streams. */
1048                 if (smb_fname->stream_name) {
1049                         return -1;
1050                 }
1051                 return acl_common_remove_object(handle,
1052                                         smb_fname->base_name,
1053                                         false);
1054         }
1055
1056         DEBUG(10,("unlink_acl_common: unlink of %s failed %s\n",
1057                 smb_fname->base_name,
1058                 strerror(errno) ));
1059         return -1;
1060 }
1061
1062 static int chmod_acl_module_common(struct vfs_handle_struct *handle,
1063                         const char *path, mode_t mode)
1064 {
1065         if (lp_posix_pathnames()) {
1066                 /* Only allow this on POSIX pathnames. */
1067                 return SMB_VFS_NEXT_CHMOD(handle, path, mode);
1068         }
1069         return 0;
1070 }
1071
1072 static int fchmod_acl_module_common(struct vfs_handle_struct *handle,
1073                         struct files_struct *fsp, mode_t mode)
1074 {
1075         if (fsp->posix_open) {
1076                 /* Only allow this on POSIX opens. */
1077                 return SMB_VFS_NEXT_FCHMOD(handle, fsp, mode);
1078         }
1079         return 0;
1080 }
1081
1082 static int chmod_acl_acl_module_common(struct vfs_handle_struct *handle,
1083                         const char *name, mode_t mode)
1084 {
1085         if (lp_posix_pathnames()) {
1086                 /* Only allow this on POSIX pathnames. */
1087                 return SMB_VFS_NEXT_CHMOD_ACL(handle, name, mode);
1088         }
1089         return 0;
1090 }
1091
1092 static int fchmod_acl_acl_module_common(struct vfs_handle_struct *handle,
1093                         struct files_struct *fsp, mode_t mode)
1094 {
1095         if (fsp->posix_open) {
1096                 /* Only allow this on POSIX opens. */
1097                 return SMB_VFS_NEXT_FCHMOD_ACL(handle, fsp, mode);
1098         }
1099         return 0;
1100 }