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                         /*
 624                          * https://bugzilla.samba.org/show_bug.cgi?id=11249
 625                          *
 626                          * We are currently guaranteed that 'name' here is
 627                          * a smb_fname->base_name, which *cannot* contain
 628                          * a stream name (':'). vfs_stat_smb_fname() splits
 629                          * a name into a base name + stream name, which
 630                          * when we get here we know we've already done.
 631                          * So we have to call the stat or lstat VFS
 632                          * calls directly here. Else, a base_name that
 633                          * contains a ':' (from a demangled name) will
 634                          * get split again.
 635                          *
 636                          * FIXME.
 637                          * This uglyness will go away once smb_fname
 638                          * is fully plumbed through the VFS.
 639                          */
 640                         int ret = vfs_stat_smb_basename(handle->conn,
 641                                                 name,
 642                                                 &sbuf);
 643                         if (ret == -1) {
 644                                 TALLOC_FREE(frame);
 645                                 return map_nt_error_from_unix(errno);
 646                         }
 647                 }
 648                 is_directory = S_ISDIR(psbuf->st_ex_mode);
 649
 650                 if (ignore_file_system_acl) {
 651                         TALLOC_FREE(pdesc_next);
 652                         status = make_default_filesystem_acl(mem_ctx,
 653                                                 name,
 654                                                 psbuf,
 655                                                 &psd);
 656                         if (!NT_STATUS_IS_OK(status)) {
 657                                 TALLOC_FREE(frame);
 658                                 return status;
 659                         }
 660                 } else {
 661                         if (is_directory &&
 662                                 !sd_has_inheritable_components(psd,
 663                                                         true)) {
 664                                 status = add_directory_inheritable_components(
 665                                                         handle,
 666                                                         name,
 667                                                         psbuf,
 668                                                         psd);
 669                                 if (!NT_STATUS_IS_OK(status)) {
 670                                         TALLOC_FREE(frame);
 671                                         return status;
 672                                 }
 673                         }
 674                         /* The underlying POSIX module always sets
 675                            the ~SEC_DESC_DACL_PROTECTED bit, as ACLs
 676                            can't be inherited in this way under POSIX.
 677                            Remove it for Windows-style ACLs. */
 678                         psd->type &= ~SEC_DESC_DACL_PROTECTED;
 679                 }
 680         }
 681
 682         if (!(security_info & SECINFO_OWNER)) {
 683                 psd->owner_sid = NULL;
 684         }
 685         if (!(security_info & SECINFO_GROUP)) {
 686                 psd->group_sid = NULL;
 687         }
 688         if (!(security_info & SECINFO_DACL)) {
 689                 psd->type &= ~SEC_DESC_DACL_PRESENT;
 690                 psd->dacl = NULL;
 691         }
 692         if (!(security_info & SECINFO_SACL)) {
 693                 psd->type &= ~SEC_DESC_SACL_PRESENT;
 694                 psd->sacl = NULL;
 695         }
 696
 697         TALLOC_FREE(blob.data);
 698
 699         if (DEBUGLEVEL >= 10) {
 700                 DEBUG(10,("get_nt_acl_internal: returning acl for %s is:\n",
 701                         name ));
 702                 NDR_PRINT_DEBUG(security_descriptor, psd);
 703         }
 704
 705         /* The VFS API is that the ACL is expected to be on mem_ctx */
 706         *ppdesc = talloc_move(mem_ctx, &psd);
 707
 708         TALLOC_FREE(frame);
 709         return NT_STATUS_OK;
 710 }
 711
 712 /*********************************************************************
 713  Fetch a security descriptor given an fsp.
 714 *********************************************************************/
 715
 716 static NTSTATUS fget_nt_acl_common(vfs_handle_struct *handle,
 717                                    files_struct *fsp,
 718                                    uint32_t security_info,
 719                                    TALLOC_CTX *mem_ctx,
 720                                    struct security_descriptor **ppdesc)
 721 {
 722         return get_nt_acl_internal(handle, fsp,
 723                                    NULL, security_info, mem_ctx, ppdesc);
 724 }
 725
 726 /*********************************************************************
 727  Fetch a security descriptor given a pathname.
 728 *********************************************************************/
 729
 730 static NTSTATUS get_nt_acl_common(vfs_handle_struct *handle,
 731                                   const char *name,
 732                                   uint32_t security_info,
 733                                   TALLOC_CTX *mem_ctx,
 734                                   struct security_descriptor **ppdesc)
 735 {
 736         return get_nt_acl_internal(handle, NULL,
 737                                    name, security_info, mem_ctx, ppdesc);
 738 }
 739
 740 /*********************************************************************
 741  Store a security descriptor given an fsp.
 742 *********************************************************************/
 743
 744 static NTSTATUS fset_nt_acl_common(vfs_handle_struct *handle, files_struct *fsp,
 745         uint32_t security_info_sent, const struct security_descriptor *orig_psd)
 746 {
 747         NTSTATUS status;
 748         int ret;
 749         DATA_BLOB blob, sys_acl_blob;
 750         struct security_descriptor *pdesc_next = NULL;
 751         struct security_descriptor *psd = NULL;
 752         uint8_t hash[XATTR_SD_HASH_SIZE];
 753         uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE];
 754         bool chown_needed = false;
 755         char *sys_acl_description;
 756         TALLOC_CTX *frame = talloc_stackframe();
 757
 758         if (DEBUGLEVEL >= 10) {
 759                 DEBUG(10,("fset_nt_acl_xattr: incoming sd for file %s\n",
 760                           fsp_str_dbg(fsp)));
 761                 NDR_PRINT_DEBUG(security_descriptor,
 762                         discard_const_p(struct security_descriptor, orig_psd));
 763         }
 764
 765         status = get_nt_acl_internal(handle, fsp,
 766                         NULL,
 767                         SECINFO_OWNER|SECINFO_GROUP|SECINFO_DACL|SECINFO_SACL,
 768                                      frame,
 769                         &psd);
 770
 771         if (!NT_STATUS_IS_OK(status)) {
 772                 TALLOC_FREE(frame);
 773                 return status;
 774         }
 775
 776         psd->revision = orig_psd->revision;
 777         /* All our SD's are self relative. */
 778         psd->type = orig_psd->type | SEC_DESC_SELF_RELATIVE;
 779
 780         if ((security_info_sent & SECINFO_OWNER) && (orig_psd->owner_sid != NULL)) {
 781                 if (!dom_sid_equal(orig_psd->owner_sid, psd->owner_sid)) {
 782                         /* We're changing the owner. */
 783                         chown_needed = true;
 784                 }
 785                 psd->owner_sid = orig_psd->owner_sid;
 786         }
 787         if ((security_info_sent & SECINFO_GROUP) && (orig_psd->group_sid != NULL)) {
 788                 if (!dom_sid_equal(orig_psd->group_sid, psd->group_sid)) {
 789                         /* We're changing the group. */
 790                         chown_needed = true;
 791                 }
 792                 psd->group_sid = orig_psd->group_sid;
 793         }
 794         if (security_info_sent & SECINFO_DACL) {
 795                 if (security_descriptor_with_ms_nfs(orig_psd)) {
 796                         /*
 797                          * If the sd contains a MS NFS SID, do
 798                          * nothing, it's a chmod() request from OS X
 799                          * with AAPL context.
 800                          */
 801                         TALLOC_FREE(frame);
 802                         return NT_STATUS_OK;
 803                 }
 804                 psd->dacl = orig_psd->dacl;
 805                 psd->type |= SEC_DESC_DACL_PRESENT;
 806         }
 807         if (security_info_sent & SECINFO_SACL) {
 808                 psd->sacl = orig_psd->sacl;
 809                 psd->type |= SEC_DESC_SACL_PRESENT;
 810         }
 811
 812         status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp, security_info_sent, psd);
 813         if (!NT_STATUS_IS_OK(status)) {
 814                 if (!NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) {
 815                         TALLOC_FREE(frame);
 816                         return status;
 817                 }
 818                 /* We got access denied here. If we're already root,
 819                    or we didn't need to do a chown, or the fsp isn't
 820                    open with WRITE_OWNER access, just return. */
 821                 if (get_current_uid(handle->conn) == 0 ||
 822                                 chown_needed == false ||
 823                                 !(fsp->access_mask & SEC_STD_WRITE_OWNER)) {
 824                         TALLOC_FREE(frame);
 825                         return NT_STATUS_ACCESS_DENIED;
 826                 }
 827
 828                 DEBUG(10,("fset_nt_acl_common: overriding chown on file %s "
 829                         "for sid %s\n",
 830                         fsp_str_dbg(fsp),
 831                         sid_string_tos(psd->owner_sid)
 832                         ));
 833
 834                 /* Ok, we failed to chown and we have
 835                    SEC_STD_WRITE_OWNER access - override. */
 836                 become_root();
 837                 status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp,
 838                                 security_info_sent, psd);
 839                 unbecome_root();
 840                 if (!NT_STATUS_IS_OK(status)) {
 841                         TALLOC_FREE(frame);
 842                         return status;
 843                 }
 844         }
 845
 846         /* Get the full underlying sd, then hash. */
 847         status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
 848                                           fsp,
 849                                           HASH_SECURITY_INFO,
 850                                           frame,
 851                                           &pdesc_next);
 852
 853         if (!NT_STATUS_IS_OK(status)) {
 854                 TALLOC_FREE(frame);
 855                 return status;
 856         }
 857
 858         status = hash_sd_sha256(pdesc_next, hash);
 859         if (!NT_STATUS_IS_OK(status)) {
 860                 TALLOC_FREE(frame);
 861                 return status;
 862         }
 863
 864         /* Get the full underlying sd, then hash. */
 865         ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FD(handle,
 866                                                fsp,
 867                                                frame,
 868                                                &sys_acl_description,
 869                                                &sys_acl_blob);
 870
 871         /* If we fail to get the ACL blob (for some reason) then this
 872          * is not fatal, we just work based on the NT ACL only */
 873         if (ret != 0) {
 874                 if (DEBUGLEVEL >= 10) {
 875                         DEBUG(10,("fset_nt_acl_xattr: storing xattr sd for file %s\n",
 876                                   fsp_str_dbg(fsp)));
 877                         NDR_PRINT_DEBUG(security_descriptor,
 878                                         discard_const_p(struct security_descriptor, psd));
 879
 880                         DEBUG(10,("fset_nt_acl_xattr: storing has in xattr sd based on \n"));
 881                         NDR_PRINT_DEBUG(security_descriptor,
 882                                         discard_const_p(struct security_descriptor, pdesc_next));
 883                 }
 884                 status = create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash);
 885                 if (!NT_STATUS_IS_OK(status)) {
 886                         DEBUG(10, ("fset_nt_acl_xattr: create_acl_blob failed\n"));
 887                         TALLOC_FREE(frame);
 888                         return status;
 889                 }
 890
 891                 status = store_acl_blob_fsp(handle, fsp, &blob);
 892
 893                 TALLOC_FREE(frame);
 894                 return status;
 895         }
 896
 897         status = hash_blob_sha256(sys_acl_blob, sys_acl_hash);
 898         if (!NT_STATUS_IS_OK(status)) {
 899                 TALLOC_FREE(frame);
 900                 return status;
 901         }
 902
 903         if (DEBUGLEVEL >= 10) {
 904                 DEBUG(10,("fset_nt_acl_xattr: storing xattr sd for file %s based on system ACL\n",
 905                           fsp_str_dbg(fsp)));
 906                 NDR_PRINT_DEBUG(security_descriptor,
 907                                 discard_const_p(struct security_descriptor, psd));
 908
 909                 DEBUG(10,("fset_nt_acl_xattr: storing hash in xattr sd based on system ACL and:\n"));
 910                 NDR_PRINT_DEBUG(security_descriptor,
 911                                 discard_const_p(struct security_descriptor, pdesc_next));
 912         }
 913
 914         /* We store hashes of both the sys ACL blob and the NT
 915          * security desciptor mapped from that ACL so as to improve
 916          * our chances against some inadvertant change breaking the
 917          * hash used */
 918         status = create_sys_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash,
 919                                      sys_acl_description, sys_acl_hash);
 920         if (!NT_STATUS_IS_OK(status)) {
 921                 DEBUG(10, ("fset_nt_acl_xattr: create_sys_acl_blob failed\n"));
 922                 TALLOC_FREE(frame);
 923                 return status;
 924         }
 925
 926         status = store_acl_blob_fsp(handle, fsp, &blob);
 927
 928         TALLOC_FREE(frame);
 929         return status;
 930 }
 931
 932 static int acl_common_remove_object(vfs_handle_struct *handle,
 933                                         const char *path,
 934                                         bool is_directory)
 935 {
 936         connection_struct *conn = handle->conn;
 937         struct file_id id;
 938         files_struct *fsp = NULL;
 939         int ret = 0;
 940         char *parent_dir = NULL;
 941         const char *final_component = NULL;
 942         struct smb_filename local_fname;
 943         int saved_errno = 0;
 944         char *saved_dir = NULL;
 945
 946         saved_dir = vfs_GetWd(talloc_tos(),conn);
 947         if (!saved_dir) {
 948                 saved_errno = errno;
 949                 goto out;
 950         }
 951
 952         if (!parent_dirname(talloc_tos(), path,
 953                         &parent_dir, &final_component)) {
 954                 saved_errno = ENOMEM;
 955                 goto out;
 956         }
 957
 958         DEBUG(10,("acl_common_remove_object: removing %s %s/%s\n",
 959                 is_directory ? "directory" : "file",
 960                 parent_dir, final_component ));
 961
 962         /* cd into the parent dir to pin it. */
 963         ret = vfs_ChDir(conn, parent_dir);
 964         if (ret == -1) {
 965                 saved_errno = errno;
 966                 goto out;
 967         }
 968
 969         ZERO_STRUCT(local_fname);
 970         local_fname.base_name = discard_const_p(char, final_component);
 971
 972         /* Must use lstat here. */
 973         ret = SMB_VFS_LSTAT(conn, &local_fname);
 974         if (ret == -1) {
 975                 saved_errno = errno;
 976                 goto out;
 977         }
 978
 979         /* Ensure we have this file open with DELETE access. */
 980         id = vfs_file_id_from_sbuf(conn, &local_fname.st);
 981         for (fsp = file_find_di_first(conn->sconn, id); fsp;
 982                      fsp = file_find_di_next(fsp)) {
 983                 if (fsp->access_mask & DELETE_ACCESS &&
 984                                 fsp->delete_on_close) {
 985                         /* We did open this for delete,
 986                          * allow the delete as root.
 987                          */
 988                         break;
 989                 }
 990         }
 991
 992         if (!fsp) {
 993                 DEBUG(10,("acl_common_remove_object: %s %s/%s "
 994                         "not an open file\n",
 995                         is_directory ? "directory" : "file",
 996                         parent_dir, final_component ));
 997                 saved_errno = EACCES;
 998                 goto out;
 999         }
1000
1001         become_root();
1002         if (is_directory) {
1003                 ret = SMB_VFS_NEXT_RMDIR(handle, final_component);
1004         } else {
1005                 ret = SMB_VFS_NEXT_UNLINK(handle, &local_fname);
1006         }
1007         unbecome_root();
1008
1009         if (ret == -1) {
1010                 saved_errno = errno;
1011         }
1012
1013   out:
1014
1015         TALLOC_FREE(parent_dir);
1016
1017         if (saved_dir) {
1018                 vfs_ChDir(conn, saved_dir);
1019         }
1020         if (saved_errno) {
1021                 errno = saved_errno;
1022         }
1023         return ret;
1024 }
1025
1026 static int rmdir_acl_common(struct vfs_handle_struct *handle,
1027                                 const char *path)
1028 {
1029         int ret;
1030
1031         /* Try the normal rmdir first. */
1032         ret = SMB_VFS_NEXT_RMDIR(handle, path);
1033         if (ret == 0) {
1034                 return 0;
1035         }
1036         if (errno == EACCES || errno == EPERM) {
1037                 /* Failed due to access denied,
1038                    see if we need to root override. */
1039                 return acl_common_remove_object(handle,
1040                                                 path,
1041                                                 true);
1042         }
1043
1044         DEBUG(10,("rmdir_acl_common: unlink of %s failed %s\n",
1045                 path,
1046                 strerror(errno) ));
1047         return -1;
1048 }
1049
1050 static int unlink_acl_common(struct vfs_handle_struct *handle,
1051                         const struct smb_filename *smb_fname)
1052 {
1053         int ret;
1054
1055         /* Try the normal unlink first. */
1056         ret = SMB_VFS_NEXT_UNLINK(handle, smb_fname);
1057         if (ret == 0) {
1058                 return 0;
1059         }
1060         if (errno == EACCES || errno == EPERM) {
1061                 /* Failed due to access denied,
1062                    see if we need to root override. */
1063
1064                 /* Don't do anything fancy for streams. */
1065                 if (smb_fname->stream_name) {
1066                         return -1;
1067                 }
1068                 return acl_common_remove_object(handle,
1069                                         smb_fname->base_name,
1070                                         false);
1071         }
1072
1073         DEBUG(10,("unlink_acl_common: unlink of %s failed %s\n",
1074                 smb_fname->base_name,
1075                 strerror(errno) ));
1076         return -1;
1077 }
1078
1079 static int chmod_acl_module_common(struct vfs_handle_struct *handle,
1080                         const char *path, mode_t mode)
1081 {
1082         if (lp_posix_pathnames()) {
1083                 /* Only allow this on POSIX pathnames. */
1084                 return SMB_VFS_NEXT_CHMOD(handle, path, mode);
1085         }
1086         return 0;
1087 }
1088
1089 static int fchmod_acl_module_common(struct vfs_handle_struct *handle,
1090                         struct files_struct *fsp, mode_t mode)
1091 {
1092         if (fsp->posix_open) {
1093                 /* Only allow this on POSIX opens. */
1094                 return SMB_VFS_NEXT_FCHMOD(handle, fsp, mode);
1095         }
1096         return 0;
1097 }
1098
1099 static int chmod_acl_acl_module_common(struct vfs_handle_struct *handle,
1100                         const char *name, mode_t mode)
1101 {
1102         if (lp_posix_pathnames()) {
1103                 /* Only allow this on POSIX pathnames. */
1104                 return SMB_VFS_NEXT_CHMOD_ACL(handle, name, mode);
1105         }
1106         return 0;
1107 }
1108
1109 static int fchmod_acl_acl_module_common(struct vfs_handle_struct *handle,
1110                         struct files_struct *fsp, mode_t mode)
1111 {
1112         if (fsp->posix_open) {
1113                 /* Only allow this on POSIX opens. */
1114                 return SMB_VFS_NEXT_FCHMOD_ACL(handle, fsp, mode);
1115         }
1116         return 0;
1117 }