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  * Copyright (C) Ralph Böhme, 2016
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 3 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  21  */
  22
  23 #include "includes.h"
  24 #include "vfs_acl_common.h"
  25 #include "smbd/smbd.h"
  26 #include "system/filesys.h"
  27 #include "librpc/gen_ndr/ndr_xattr.h"
  28 #include "../libcli/security/security.h"
  29 #include "../librpc/gen_ndr/ndr_security.h"
  30 #include "../lib/util/bitmap.h"
  31 #include "lib/crypto/sha256.h"
  32 #include "passdb/lookup_sid.h"
  33
  34 static NTSTATUS create_acl_blob(const struct security_descriptor *psd,
  35                         DATA_BLOB *pblob,
  36                         uint16_t hash_type,
  37                         uint8_t hash[XATTR_SD_HASH_SIZE]);
  38
  39 #define HASH_SECURITY_INFO (SECINFO_OWNER | \
  40                                 SECINFO_GROUP | \
  41                                 SECINFO_DACL | \
  42                                 SECINFO_SACL)
  43
  44 bool init_acl_common_config(vfs_handle_struct *handle,
  45                             const char *module_name)
  46 {
  47         struct acl_common_config *config = NULL;
  48         const struct enum_list *default_acl_style_list = NULL;
  49
  50         default_acl_style_list = get_default_acl_style_list();
  51
  52         config = talloc_zero(handle->conn, struct acl_common_config);
  53         if (config == NULL) {
  54                 DBG_ERR("talloc_zero() failed\n");
  55                 errno = ENOMEM;
  56                 return false;
  57         }
  58
  59         config->ignore_system_acls = lp_parm_bool(SNUM(handle->conn),
  60                                                   module_name,
  61                                                   "ignore system acls",
  62                                                   false);
  63         config->default_acl_style = lp_parm_enum(SNUM(handle->conn),
  64                                                  module_name,
  65                                                  "default acl style",
  66                                                  default_acl_style_list,
  67                                                  DEFAULT_ACL_POSIX);
  68
  69         SMB_VFS_HANDLE_SET_DATA(handle, config, NULL,
  70                                 struct acl_common_config,
  71                                 return false);
  72
  73         return true;
  74 }
  75
  76
  77 /*******************************************************************
  78  Hash a security descriptor.
  79 *******************************************************************/
  80
  81 static NTSTATUS hash_blob_sha256(DATA_BLOB blob,
  82                                  uint8_t *hash)
  83 {
  84         SHA256_CTX tctx;
  85
  86         memset(hash, '\0', XATTR_SD_HASH_SIZE);
  87
  88         samba_SHA256_Init(&tctx);
  89         samba_SHA256_Update(&tctx, blob.data, blob.length);
  90         samba_SHA256_Final(hash, &tctx);
  91
  92         return NT_STATUS_OK;
  93 }
  94
  95 /*******************************************************************
  96  Hash a security descriptor.
  97 *******************************************************************/
  98
  99 static NTSTATUS hash_sd_sha256(struct security_descriptor *psd,
 100                         uint8_t *hash)
 101 {
 102         DATA_BLOB blob;
 103         NTSTATUS status;
 104
 105         memset(hash, '\0', XATTR_SD_HASH_SIZE);
 106         status = create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash);
 107         if (!NT_STATUS_IS_OK(status)) {
 108                 return status;
 109         }
 110         return hash_blob_sha256(blob, hash);
 111 }
 112
 113 /*******************************************************************
 114  Parse out a struct security_descriptor from a DATA_BLOB.
 115 *******************************************************************/
 116
 117 static NTSTATUS parse_acl_blob(const DATA_BLOB *pblob,
 118                                TALLOC_CTX *mem_ctx,
 119                                struct security_descriptor **ppdesc,
 120                                uint16_t *p_hash_type,
 121                                uint16_t *p_version,
 122                                uint8_t hash[XATTR_SD_HASH_SIZE],
 123                                uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE])
 124 {
 125         struct xattr_NTACL xacl;
 126         enum ndr_err_code ndr_err;
 127         size_t sd_size;
 128         TALLOC_CTX *frame = talloc_stackframe();
 129
 130         ndr_err = ndr_pull_struct_blob(pblob, frame, &xacl,
 131                         (ndr_pull_flags_fn_t)ndr_pull_xattr_NTACL);
 132
 133         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 134                 DBG_INFO("ndr_pull_xattr_NTACL failed: %s\n",
 135                          ndr_errstr(ndr_err));
 136                 TALLOC_FREE(frame);
 137                 return ndr_map_error2ntstatus(ndr_err);
 138         }
 139
 140         *p_version = xacl.version;
 141
 142         switch (xacl.version) {
 143                 case 1:
 144                         *ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
 145                                         xacl.info.sd->type | SEC_DESC_SELF_RELATIVE,
 146                                         xacl.info.sd->owner_sid,
 147                                         xacl.info.sd->group_sid,
 148                                         xacl.info.sd->sacl,
 149                                         xacl.info.sd->dacl,
 150                                         &sd_size);
 151                         /* No hash - null out. */
 152                         *p_hash_type = XATTR_SD_HASH_TYPE_NONE;
 153                         memset(hash, '\0', XATTR_SD_HASH_SIZE);
 154                         break;
 155                 case 2:
 156                         *ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
 157                                         xacl.info.sd_hs2->sd->type | SEC_DESC_SELF_RELATIVE,
 158                                         xacl.info.sd_hs2->sd->owner_sid,
 159                                         xacl.info.sd_hs2->sd->group_sid,
 160                                         xacl.info.sd_hs2->sd->sacl,
 161                                         xacl.info.sd_hs2->sd->dacl,
 162                                         &sd_size);
 163                         /* No hash - null out. */
 164                         *p_hash_type = XATTR_SD_HASH_TYPE_NONE;
 165                         memset(hash, '\0', XATTR_SD_HASH_SIZE);
 166                         break;
 167                 case 3:
 168                         *ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
 169                                         xacl.info.sd_hs3->sd->type | SEC_DESC_SELF_RELATIVE,
 170                                         xacl.info.sd_hs3->sd->owner_sid,
 171                                         xacl.info.sd_hs3->sd->group_sid,
 172                                         xacl.info.sd_hs3->sd->sacl,
 173                                         xacl.info.sd_hs3->sd->dacl,
 174                                         &sd_size);
 175                         *p_hash_type = xacl.info.sd_hs3->hash_type;
 176                         /* Current version 3 (if no sys acl hash available). */
 177                         memcpy(hash, xacl.info.sd_hs3->hash, XATTR_SD_HASH_SIZE);
 178                         break;
 179                 case 4:
 180                         *ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
 181                                         xacl.info.sd_hs4->sd->type | SEC_DESC_SELF_RELATIVE,
 182                                         xacl.info.sd_hs4->sd->owner_sid,
 183                                         xacl.info.sd_hs4->sd->group_sid,
 184                                         xacl.info.sd_hs4->sd->sacl,
 185                                         xacl.info.sd_hs4->sd->dacl,
 186                                         &sd_size);
 187                         *p_hash_type = xacl.info.sd_hs4->hash_type;
 188                         /* Current version 4. */
 189                         memcpy(hash, xacl.info.sd_hs4->hash, XATTR_SD_HASH_SIZE);
 190                         memcpy(sys_acl_hash, xacl.info.sd_hs4->sys_acl_hash, XATTR_SD_HASH_SIZE);
 191                         break;
 192                 default:
 193                         TALLOC_FREE(frame);
 194                         return NT_STATUS_REVISION_MISMATCH;
 195         }
 196
 197         TALLOC_FREE(frame);
 198
 199         return (*ppdesc != NULL) ? NT_STATUS_OK : NT_STATUS_NO_MEMORY;
 200 }
 201
 202 /*******************************************************************
 203  Create a DATA_BLOB from a hash of the security descriptor storead at
 204  the system layer and the NT ACL we wish to preserve
 205 *******************************************************************/
 206
 207 static NTSTATUS create_acl_blob(const struct security_descriptor *psd,
 208                         DATA_BLOB *pblob,
 209                         uint16_t hash_type,
 210                         uint8_t hash[XATTR_SD_HASH_SIZE])
 211 {
 212         struct xattr_NTACL xacl;
 213         struct security_descriptor_hash_v3 sd_hs3;
 214         enum ndr_err_code ndr_err;
 215         TALLOC_CTX *ctx = talloc_tos();
 216
 217         ZERO_STRUCT(xacl);
 218         ZERO_STRUCT(sd_hs3);
 219
 220         xacl.version = 3;
 221         xacl.info.sd_hs3 = &sd_hs3;
 222         xacl.info.sd_hs3->sd = discard_const_p(struct security_descriptor, psd);
 223         xacl.info.sd_hs3->hash_type = hash_type;
 224         memcpy(&xacl.info.sd_hs3->hash[0], hash, XATTR_SD_HASH_SIZE);
 225
 226         ndr_err = ndr_push_struct_blob(
 227                         pblob, ctx, &xacl,
 228                         (ndr_push_flags_fn_t)ndr_push_xattr_NTACL);
 229
 230         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 231                 DBG_INFO("ndr_push_xattr_NTACL failed: %s\n",
 232                          ndr_errstr(ndr_err));
 233                 return ndr_map_error2ntstatus(ndr_err);
 234         }
 235
 236         return NT_STATUS_OK;
 237 }
 238
 239 /*******************************************************************
 240  Create a DATA_BLOB from a hash of the security descriptors
 241  (system and NT) stored at the system layer and the NT ACL we wish
 242  to preserve.
 243 *******************************************************************/
 244
 245 static NTSTATUS create_sys_acl_blob(const struct security_descriptor *psd,
 246                                     DATA_BLOB *pblob,
 247                                     uint16_t hash_type,
 248                                     uint8_t hash[XATTR_SD_HASH_SIZE],
 249                                     const char *description,
 250                                     uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE])
 251 {
 252         struct xattr_NTACL xacl;
 253         struct security_descriptor_hash_v4 sd_hs4;
 254         enum ndr_err_code ndr_err;
 255         TALLOC_CTX *ctx = talloc_tos();
 256         NTTIME nttime_now;
 257         struct timeval now = timeval_current();
 258         nttime_now = timeval_to_nttime(&now);
 259
 260         ZERO_STRUCT(xacl);
 261         ZERO_STRUCT(sd_hs4);
 262
 263         xacl.version = 4;
 264         xacl.info.sd_hs4 = &sd_hs4;
 265         xacl.info.sd_hs4->sd = discard_const_p(struct security_descriptor, psd);
 266         xacl.info.sd_hs4->hash_type = hash_type;
 267         memcpy(&xacl.info.sd_hs4->hash[0], hash, XATTR_SD_HASH_SIZE);
 268         xacl.info.sd_hs4->description = description;
 269         xacl.info.sd_hs4->time = nttime_now;
 270         memcpy(&xacl.info.sd_hs4->sys_acl_hash[0], sys_acl_hash, XATTR_SD_HASH_SIZE);
 271
 272         ndr_err = ndr_push_struct_blob(
 273                         pblob, ctx, &xacl,
 274                         (ndr_push_flags_fn_t)ndr_push_xattr_NTACL);
 275
 276         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 277                 DBG_INFO("ndr_push_xattr_NTACL failed: %s\n",
 278                          ndr_errstr(ndr_err));
 279                 return ndr_map_error2ntstatus(ndr_err);
 280         }
 281
 282         return NT_STATUS_OK;
 283 }
 284
 285 /*******************************************************************
 286  Add in 3 inheritable components for a non-inheritable directory ACL.
 287  CREATOR_OWNER/CREATOR_GROUP/WORLD.
 288 *******************************************************************/
 289
 290 static NTSTATUS add_directory_inheritable_components(vfs_handle_struct *handle,
 291                                 const char *name,
 292                                 SMB_STRUCT_STAT *psbuf,
 293                                 struct security_descriptor *psd)
 294 {
 295         struct connection_struct *conn = handle->conn;
 296         int num_aces = (psd->dacl ? psd->dacl->num_aces : 0);
 297         struct smb_filename smb_fname;
 298         enum security_ace_type acltype;
 299         uint32_t access_mask;
 300         mode_t dir_mode;
 301         mode_t file_mode;
 302         mode_t mode;
 303         struct security_ace *new_ace_list;
 304
 305         if (psd->dacl) {
 306                 new_ace_list = talloc_zero_array(psd->dacl,
 307                                                  struct security_ace,
 308                                                  num_aces + 3);
 309         } else {
 310                 /*
 311                  * make_sec_acl() at the bottom of this function
 312                  * dupliates new_ace_list
 313                  */
 314                 new_ace_list = talloc_zero_array(talloc_tos(),
 315                                                  struct security_ace,
 316                                                  num_aces + 3);
 317         }
 318
 319         if (new_ace_list == NULL) {
 320                 return NT_STATUS_NO_MEMORY;
 321         }
 322
 323         /* Fake a quick smb_filename. */
 324         ZERO_STRUCT(smb_fname);
 325         smb_fname.st = *psbuf;
 326         smb_fname.base_name = discard_const_p(char, name);
 327
 328         dir_mode = unix_mode(conn,
 329                         FILE_ATTRIBUTE_DIRECTORY, &smb_fname, NULL);
 330         file_mode = unix_mode(conn,
 331                         FILE_ATTRIBUTE_ARCHIVE, &smb_fname, NULL);
 332
 333         mode = dir_mode | file_mode;
 334
 335         DBG_DEBUG("directory %s, mode = 0%o\n", name, (unsigned int)mode);
 336
 337         if (num_aces) {
 338                 memcpy(new_ace_list, psd->dacl->aces,
 339                         num_aces * sizeof(struct security_ace));
 340         }
 341         access_mask = map_canon_ace_perms(SNUM(conn), &acltype,
 342                                 mode & 0700, false);
 343
 344         init_sec_ace(&new_ace_list[num_aces],
 345                         &global_sid_Creator_Owner,
 346                         acltype,
 347                         access_mask,
 348                         SEC_ACE_FLAG_CONTAINER_INHERIT|
 349                                 SEC_ACE_FLAG_OBJECT_INHERIT|
 350                                 SEC_ACE_FLAG_INHERIT_ONLY);
 351         access_mask = map_canon_ace_perms(SNUM(conn), &acltype,
 352                                 (mode << 3) & 0700, false);
 353         init_sec_ace(&new_ace_list[num_aces+1],
 354                         &global_sid_Creator_Group,
 355                         acltype,
 356                         access_mask,
 357                         SEC_ACE_FLAG_CONTAINER_INHERIT|
 358                                 SEC_ACE_FLAG_OBJECT_INHERIT|
 359                                 SEC_ACE_FLAG_INHERIT_ONLY);
 360         access_mask = map_canon_ace_perms(SNUM(conn), &acltype,
 361                                 (mode << 6) & 0700, false);
 362         init_sec_ace(&new_ace_list[num_aces+2],
 363                         &global_sid_World,
 364                         acltype,
 365                         access_mask,
 366                         SEC_ACE_FLAG_CONTAINER_INHERIT|
 367                                 SEC_ACE_FLAG_OBJECT_INHERIT|
 368                                 SEC_ACE_FLAG_INHERIT_ONLY);
 369         if (psd->dacl) {
 370                 psd->dacl->aces = new_ace_list;
 371                 psd->dacl->num_aces += 3;
 372                 psd->dacl->size += new_ace_list[num_aces].size +
 373                         new_ace_list[num_aces+1].size +
 374                         new_ace_list[num_aces+2].size;
 375         } else {
 376                 psd->dacl = make_sec_acl(psd,
 377                                 NT4_ACL_REVISION,
 378                                 3,
 379                                 new_ace_list);
 380                 if (psd->dacl == NULL) {
 381                         return NT_STATUS_NO_MEMORY;
 382                 }
 383         }
 384         return NT_STATUS_OK;
 385 }
 386
 387 /**
 388  * Validate an ACL blob
 389  *
 390  * This validates an ACL blob against the underlying filesystem ACL. If this
 391  * function returns NT_STATUS_OK ppsd can be
 392  *
 393  * 1. the ACL from the blob (psd_from_fs=false), or
 394  * 2. the ACL from the fs (psd_from_fs=true), or
 395  * 3. NULL (!)
 396  *
 397  * If the return value is anything else then NT_STATUS_OK, ppsd is set to NULL
 398  * and psd_from_fs set to false.
 399  *
 400  * Returning the underlying filesystem ACL in case no. 2 is really just an
 401  * optimisation, because some validations have to fetch the filesytem ACL as
 402  * part of the validation, so we already have it available and callers might
 403  * need it as well.
 404  **/
 405 static NTSTATUS validate_nt_acl_blob(TALLOC_CTX *mem_ctx,
 406                                      vfs_handle_struct *handle,
 407                                      files_struct *fsp,
 408                                      const struct smb_filename *smb_fname,
 409                                      const DATA_BLOB *blob,
 410                                      struct security_descriptor **ppsd,
 411                                      bool *psd_is_from_fs)
 412 {
 413         NTSTATUS status;
 414         uint16_t hash_type = XATTR_SD_HASH_TYPE_NONE;
 415         uint16_t xattr_version = 0;
 416         uint8_t hash[XATTR_SD_HASH_SIZE];
 417         uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE];
 418         uint8_t hash_tmp[XATTR_SD_HASH_SIZE];
 419         uint8_t sys_acl_hash_tmp[XATTR_SD_HASH_SIZE];
 420         struct security_descriptor *psd = NULL;
 421         struct security_descriptor *psd_blob = NULL;
 422         struct security_descriptor *psd_fs = NULL;
 423         char *sys_acl_blob_description = NULL;
 424         DATA_BLOB sys_acl_blob = { 0 };
 425         struct acl_common_config *config = NULL;
 426
 427         *ppsd = NULL;
 428         *psd_is_from_fs = false;
 429
 430         SMB_VFS_HANDLE_GET_DATA(handle, config,
 431                                 struct acl_common_config,
 432                                 return NT_STATUS_UNSUCCESSFUL);
 433
 434         status = parse_acl_blob(blob,
 435                                 mem_ctx,
 436                                 &psd_blob,
 437                                 &hash_type,
 438                                 &xattr_version,
 439                                 &hash[0],
 440                                 &sys_acl_hash[0]);
 441         if (!NT_STATUS_IS_OK(status)) {
 442                 DBG_DEBUG("parse_acl_blob returned %s\n", nt_errstr(status));
 443                 goto fail;
 444         }
 445
 446         /* determine which type of xattr we got */
 447         switch (xattr_version) {
 448         case 1:
 449         case 2:
 450                 /* These xattr types are unilatteral, they do not
 451                  * require confirmation of the hash.  In particular,
 452                  * the NTVFS file server uses version 1, but
 453                  * 'samba-tool ntacl' can set these as well */
 454                 *ppsd = psd_blob;
 455                 return NT_STATUS_OK;
 456         case 3:
 457         case 4:
 458                 if (config->ignore_system_acls) {
 459                         *ppsd = psd_blob;
 460                         return NT_STATUS_OK;
 461                 }
 462
 463                 break;
 464         default:
 465                 DBG_DEBUG("ACL blob revision mismatch (%u) for file %s\n",
 466                           (unsigned int)hash_type, smb_fname->base_name);
 467                 TALLOC_FREE(psd_blob);
 468                 return NT_STATUS_OK;
 469         }
 470
 471         /* determine which type of xattr we got */
 472         if (hash_type != XATTR_SD_HASH_TYPE_SHA256) {
 473                 DBG_DEBUG("ACL blob hash type (%u) unexpected for file %s\n",
 474                           (unsigned int)hash_type, smb_fname->base_name);
 475                 TALLOC_FREE(psd_blob);
 476                 return NT_STATUS_OK;
 477         }
 478
 479         /* determine which type of xattr we got */
 480         switch (xattr_version) {
 481         case 4:
 482         {
 483                 int ret;
 484                 if (fsp) {
 485                         /* Get the full underlying sd, then hash. */
 486                         ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FD(handle,
 487                                                                fsp,
 488                                                                mem_ctx,
 489                                                                &sys_acl_blob_description,
 490                                                                &sys_acl_blob);
 491                 } else {
 492                         /* Get the full underlying sd, then hash. */
 493                         ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FILE(handle,
 494                                                  smb_fname,
 495                                                  mem_ctx,
 496                                                  &sys_acl_blob_description,
 497                                                  &sys_acl_blob);
 498                 }
 499
 500                 /* If we fail to get the ACL blob (for some reason) then this
 501                  * is not fatal, we just work based on the NT ACL only */
 502                 if (ret == 0) {
 503                         status = hash_blob_sha256(sys_acl_blob, sys_acl_hash_tmp);
 504                         if (!NT_STATUS_IS_OK(status)) {
 505                                 goto fail;
 506                         }
 507
 508                         TALLOC_FREE(sys_acl_blob_description);
 509                         TALLOC_FREE(sys_acl_blob.data);
 510
 511                         if (memcmp(&sys_acl_hash[0], &sys_acl_hash_tmp[0],
 512                                    XATTR_SD_HASH_SIZE) == 0) {
 513                                 /* Hash matches, return blob sd. */
 514                                 DBG_DEBUG("blob hash matches for file %s\n",
 515                                           smb_fname->base_name);
 516                                 *ppsd = psd_blob;
 517                                 return NT_STATUS_OK;
 518                         }
 519                 }
 520
 521                 /* Otherwise, fall though and see if the NT ACL hash matches */
 522                 FALL_THROUGH;
 523         }
 524         case 3:
 525                 /* Get the full underlying sd for the hash
 526                    or to return as backup. */
 527                 if (fsp) {
 528                         status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
 529                                                           fsp,
 530                                                           HASH_SECURITY_INFO,
 531                                                           mem_ctx,
 532                                                           &psd_fs);
 533                 } else {
 534                         status = SMB_VFS_NEXT_GET_NT_ACL(handle,
 535                                                          smb_fname,
 536                                                          HASH_SECURITY_INFO,
 537                                                          mem_ctx,
 538                                                          &psd_fs);
 539                 }
 540
 541                 if (!NT_STATUS_IS_OK(status)) {
 542                         DBG_DEBUG("get_next_acl for file %s returned %s\n",
 543                                   smb_fname->base_name, nt_errstr(status));
 544                         goto fail;
 545                 }
 546
 547                 status = hash_sd_sha256(psd_fs, hash_tmp);
 548                 if (!NT_STATUS_IS_OK(status)) {
 549                         TALLOC_FREE(psd_blob);
 550                         *ppsd = psd_fs;
 551                         *psd_is_from_fs = true;
 552                         return NT_STATUS_OK;
 553                 }
 554
 555                 if (memcmp(&hash[0], &hash_tmp[0], XATTR_SD_HASH_SIZE) == 0) {
 556                         /* Hash matches, return blob sd. */
 557                         DBG_DEBUG("blob hash matches for file %s\n",
 558                                   smb_fname->base_name);
 559                         *ppsd = psd_blob;
 560                         return NT_STATUS_OK;
 561                 }
 562
 563                 /* Hash doesn't match, return underlying sd. */
 564                 DBG_DEBUG("blob hash does not match for file %s - returning "
 565                           "file system SD mapping.\n",
 566                           smb_fname->base_name);
 567
 568                 if (DEBUGLEVEL >= 10) {
 569                         DBG_DEBUG("acl for blob hash for %s is:\n",
 570                                   smb_fname->base_name);
 571                         NDR_PRINT_DEBUG(security_descriptor, psd_fs);
 572                 }
 573
 574                 TALLOC_FREE(psd_blob);
 575                 *ppsd = psd_fs;
 576                 *psd_is_from_fs = true;
 577         }
 578
 579         return NT_STATUS_OK;
 580
 581 fail:
 582         TALLOC_FREE(psd);
 583         TALLOC_FREE(psd_blob);
 584         TALLOC_FREE(psd_fs);
 585         TALLOC_FREE(sys_acl_blob_description);
 586         TALLOC_FREE(sys_acl_blob.data);
 587         return status;
 588 }
 589
 590 static NTSTATUS stat_fsp_or_smb_fname(vfs_handle_struct *handle,
 591                                       files_struct *fsp,
 592                                       const struct smb_filename *smb_fname,
 593                                       SMB_STRUCT_STAT *sbuf,
 594                                       SMB_STRUCT_STAT **psbuf)
 595 {
 596         NTSTATUS status;
 597         int ret;
 598
 599         if (fsp) {
 600                 status = vfs_stat_fsp(fsp);
 601                 if (!NT_STATUS_IS_OK(status)) {
 602                         return status;
 603                 }
 604                 *psbuf = &fsp->fsp_name->st;
 605         } else {
 606                 /*
 607                  * https://bugzilla.samba.org/show_bug.cgi?id=11249
 608                  *
 609                  * We are currently guaranteed that 'name' here is a
 610                  * smb_fname->base_name, which *cannot* contain a stream name
 611                  * (':'). vfs_stat_smb_fname() splits a name into a base name +
 612                  * stream name, which when we get here we know we've already
 613                  * done.  So we have to call the stat or lstat VFS calls
 614                  * directly here. Else, a base_name that contains a ':' (from a
 615                  * demangled name) will get split again.
 616                  *
 617                  * FIXME.
 618                  * This uglyness will go away once smb_fname is fully plumbed
 619                  * through the VFS.
 620                  */
 621                 ret = vfs_stat_smb_basename(handle->conn,
 622                                             smb_fname,
 623                                             sbuf);
 624                 if (ret == -1) {
 625                         return map_nt_error_from_unix(errno);
 626                 }
 627         }
 628
 629         return NT_STATUS_OK;
 630 }
 631
 632 /*******************************************************************
 633  Pull a DATA_BLOB from an xattr given a pathname.
 634  If the hash doesn't match, or doesn't exist - return the underlying
 635  filesystem sd.
 636 *******************************************************************/
 637
 638 NTSTATUS get_nt_acl_common(
 639         NTSTATUS (*get_acl_blob_fn)(TALLOC_CTX *ctx,
 640                                     vfs_handle_struct *handle,
 641                                     files_struct *fsp,
 642                                     const struct smb_filename *smb_fname,
 643                                     DATA_BLOB *pblob),
 644         vfs_handle_struct *handle,
 645         files_struct *fsp,
 646         const struct smb_filename *smb_fname_in,
 647         uint32_t security_info,
 648         TALLOC_CTX *mem_ctx,
 649         struct security_descriptor **ppdesc)
 650 {
 651         DATA_BLOB blob = data_blob_null;
 652         NTSTATUS status;
 653         struct security_descriptor *psd = NULL;
 654         const struct smb_filename *smb_fname = NULL;
 655         bool psd_is_from_fs = false;
 656         struct acl_common_config *config = NULL;
 657
 658         SMB_VFS_HANDLE_GET_DATA(handle, config,
 659                                 struct acl_common_config,
 660                                 return NT_STATUS_UNSUCCESSFUL);
 661
 662         if (fsp && smb_fname_in == NULL) {
 663                 smb_fname = fsp->fsp_name;
 664         } else {
 665                 smb_fname = smb_fname_in;
 666         }
 667
 668         DBG_DEBUG("name=%s\n", smb_fname->base_name);
 669
 670         status = get_acl_blob_fn(mem_ctx, handle, fsp, smb_fname, &blob);
 671         if (NT_STATUS_IS_OK(status)) {
 672                 status = validate_nt_acl_blob(mem_ctx,
 673                                               handle,
 674                                               fsp,
 675                                               smb_fname,
 676                                               &blob,
 677                                               &psd,
 678                                               &psd_is_from_fs);
 679                 TALLOC_FREE(blob.data);
 680                 if (!NT_STATUS_IS_OK(status)) {
 681                         DBG_DEBUG("ACL validation for [%s] failed\n",
 682                                   smb_fname->base_name);
 683                         goto fail;
 684                 }
 685         }
 686
 687         if (psd == NULL) {
 688                 /* Get the full underlying sd, as we failed to get the
 689                  * blob for the hash, or the revision/hash type wasn't
 690                  * known */
 691
 692                 if (config->ignore_system_acls) {
 693                         SMB_STRUCT_STAT sbuf;
 694                         SMB_STRUCT_STAT *psbuf = &sbuf;
 695
 696                         status = stat_fsp_or_smb_fname(handle, fsp, smb_fname,
 697                                                        &sbuf, &psbuf);
 698                         if (!NT_STATUS_IS_OK(status)) {
 699                                 goto fail;
 700                         }
 701
 702                         status = make_default_filesystem_acl(
 703                                 mem_ctx,
 704                                 config->default_acl_style,
 705                                 smb_fname->base_name,
 706                                 psbuf,
 707                                 &psd);
 708                         if (!NT_STATUS_IS_OK(status)) {
 709                                 goto fail;
 710                         }
 711                 } else {
 712                         if (fsp) {
 713                                 status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
 714                                                                   fsp,
 715                                                                   security_info,
 716                                                                   mem_ctx,
 717                                                                   &psd);
 718                         } else {
 719                                 status = SMB_VFS_NEXT_GET_NT_ACL(handle,
 720                                                                  smb_fname,
 721                                                                  security_info,
 722                                                                  mem_ctx,
 723                                                                  &psd);
 724                         }
 725
 726                         if (!NT_STATUS_IS_OK(status)) {
 727                                 DBG_DEBUG("get_next_acl for file %s "
 728                                           "returned %s\n",
 729                                           smb_fname->base_name,
 730                                           nt_errstr(status));
 731                                 goto fail;
 732                         }
 733
 734                         psd_is_from_fs = true;
 735                 }
 736         }
 737
 738         if (psd_is_from_fs) {
 739                 SMB_STRUCT_STAT sbuf;
 740                 SMB_STRUCT_STAT *psbuf = &sbuf;
 741                 bool is_directory = false;
 742
 743                 /*
 744                  * We're returning the underlying ACL from the
 745                  * filesystem. If it's a directory, and has no
 746                  * inheritable ACE entries we have to fake them.
 747                  */
 748
 749                 status = stat_fsp_or_smb_fname(handle, fsp, smb_fname,
 750                                                &sbuf, &psbuf);
 751                 if (!NT_STATUS_IS_OK(status)) {
 752                         goto fail;
 753                 }
 754
 755                 is_directory = S_ISDIR(psbuf->st_ex_mode);
 756
 757                 if (is_directory && !sd_has_inheritable_components(psd, true)) {
 758                         status = add_directory_inheritable_components(
 759                                 handle,
 760                                 smb_fname->base_name,
 761                                 psbuf,
 762                                 psd);
 763                         if (!NT_STATUS_IS_OK(status)) {
 764                                 goto fail;
 765                         }
 766                 }
 767
 768                 /*
 769                  * The underlying POSIX module always sets the
 770                  * ~SEC_DESC_DACL_PROTECTED bit, as ACLs can't be inherited in
 771                  * this way under POSIX. Remove it for Windows-style ACLs.
 772                  */
 773                 psd->type &= ~SEC_DESC_DACL_PROTECTED;
 774         }
 775
 776         if (!(security_info & SECINFO_OWNER)) {
 777                 psd->owner_sid = NULL;
 778         }
 779         if (!(security_info & SECINFO_GROUP)) {
 780                 psd->group_sid = NULL;
 781         }
 782         if (!(security_info & SECINFO_DACL)) {
 783                 psd->type &= ~SEC_DESC_DACL_PRESENT;
 784                 psd->dacl = NULL;
 785         }
 786         if (!(security_info & SECINFO_SACL)) {
 787                 psd->type &= ~SEC_DESC_SACL_PRESENT;
 788                 psd->sacl = NULL;
 789         }
 790
 791         if (DEBUGLEVEL >= 10) {
 792                 DBG_DEBUG("returning acl for %s is:\n",
 793                           smb_fname->base_name);
 794                 NDR_PRINT_DEBUG(security_descriptor, psd);
 795         }
 796
 797         *ppdesc = psd;
 798
 799         return NT_STATUS_OK;
 800
 801 fail:
 802         TALLOC_FREE(psd);
 803         return status;
 804 }
 805
 806 /*********************************************************************
 807  Set the underlying ACL (e.g. POSIX ACLS, POSIX owner, etc)
 808 *********************************************************************/
 809 static NTSTATUS set_underlying_acl(vfs_handle_struct *handle, files_struct *fsp,
 810                                    struct security_descriptor *psd,
 811                                    uint32_t security_info_sent,
 812                                    bool chown_needed)
 813 {
 814         NTSTATUS status;
 815         const struct security_token *token = NULL;
 816
 817         status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp, security_info_sent, psd);
 818         if (!NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) {
 819                 return status;
 820         }
 821
 822         /* We got access denied here. If we're already root,
 823            or we didn't need to do a chown, or the fsp isn't
 824            open with WRITE_OWNER access, just return. */
 825         if (get_current_uid(handle->conn) == 0 || chown_needed == false ||
 826             !(fsp->access_mask & SEC_STD_WRITE_OWNER)) {
 827                 return NT_STATUS_ACCESS_DENIED;
 828         }
 829
 830         /*
 831          * Only allow take-ownership, not give-ownership. That's the way Windows
 832          * implements SEC_STD_WRITE_OWNER. MS-FSA 2.1.5.16 just states: If
 833          * InputBuffer.OwnerSid is not a valid owner SID for a file in the
 834          * objectstore, as determined in an implementation specific manner, the
 835          * object store MUST return STATUS_INVALID_OWNER.
 836          */
 837         token = get_current_nttok(fsp->conn);
 838         if (!security_token_is_sid(token, psd->owner_sid)) {
 839                 return NT_STATUS_INVALID_OWNER;
 840         }
 841
 842         DBG_DEBUG("overriding chown on file %s for sid %s\n",
 843                    fsp_str_dbg(fsp), sid_string_tos(psd->owner_sid));
 844
 845         /* Ok, we failed to chown and we have
 846            SEC_STD_WRITE_OWNER access - override. */
 847         become_root();
 848         status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp, security_info_sent, psd);
 849         unbecome_root();
 850
 851         return status;
 852 }
 853
 854 /*********************************************************************
 855  Store a v3 security descriptor
 856 *********************************************************************/
 857 static NTSTATUS store_v3_blob(
 858         NTSTATUS (*store_acl_blob_fsp_fn)(vfs_handle_struct *handle,
 859                                           files_struct *fsp,
 860                                           DATA_BLOB *pblob),
 861         vfs_handle_struct *handle, files_struct *fsp,
 862         struct security_descriptor *psd,
 863         struct security_descriptor *pdesc_next,
 864         uint8_t hash[XATTR_SD_HASH_SIZE])
 865 {
 866         NTSTATUS status;
 867         DATA_BLOB blob;
 868
 869         if (DEBUGLEVEL >= 10) {
 870                 DBG_DEBUG("storing xattr sd for file %s\n",
 871                           fsp_str_dbg(fsp));
 872                 NDR_PRINT_DEBUG(
 873                     security_descriptor,
 874                     discard_const_p(struct security_descriptor, psd));
 875
 876                 if (pdesc_next != NULL) {
 877                         DBG_DEBUG("storing xattr sd based on \n");
 878                         NDR_PRINT_DEBUG(
 879                             security_descriptor,
 880                             discard_const_p(struct security_descriptor,
 881                                             pdesc_next));
 882                 } else {
 883                         DBG_DEBUG("ignoring underlying sd\n");
 884                 }
 885         }
 886         status = create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash);
 887         if (!NT_STATUS_IS_OK(status)) {
 888                 DBG_DEBUG("create_acl_blob failed\n");
 889                 return status;
 890         }
 891
 892         status = store_acl_blob_fsp_fn(handle, fsp, &blob);
 893         return status;
 894 }
 895
 896 /*********************************************************************
 897  Store a security descriptor given an fsp.
 898 *********************************************************************/
 899
 900 NTSTATUS fset_nt_acl_common(
 901         NTSTATUS (*get_acl_blob_fn)(TALLOC_CTX *ctx,
 902                                     vfs_handle_struct *handle,
 903                                     files_struct *fsp,
 904                                     const struct smb_filename *smb_fname,
 905                                     DATA_BLOB *pblob),
 906         NTSTATUS (*store_acl_blob_fsp_fn)(vfs_handle_struct *handle,
 907                                           files_struct *fsp,
 908                                           DATA_BLOB *pblob),
 909         const char *module_name,
 910         vfs_handle_struct *handle, files_struct *fsp,
 911         uint32_t security_info_sent,
 912         const struct security_descriptor *orig_psd)
 913 {
 914         NTSTATUS status;
 915         int ret;
 916         DATA_BLOB blob, sys_acl_blob;
 917         struct security_descriptor *pdesc_next = NULL;
 918         struct security_descriptor *psd = NULL;
 919         uint8_t hash[XATTR_SD_HASH_SIZE];
 920         uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE];
 921         bool chown_needed = false;
 922         char *sys_acl_description;
 923         TALLOC_CTX *frame = talloc_stackframe();
 924         bool ignore_file_system_acl = lp_parm_bool(
 925             SNUM(handle->conn), module_name, "ignore system acls", false);
 926
 927         if (DEBUGLEVEL >= 10) {
 928                 DBG_DEBUG("incoming sd for file %s\n", fsp_str_dbg(fsp));
 929                 NDR_PRINT_DEBUG(security_descriptor,
 930                         discard_const_p(struct security_descriptor, orig_psd));
 931         }
 932
 933         status = get_nt_acl_common(get_acl_blob_fn, handle, fsp,
 934                         NULL,
 935                         SECINFO_OWNER|SECINFO_GROUP|SECINFO_DACL|SECINFO_SACL,
 936                                      frame,
 937                         &psd);
 938
 939         if (!NT_STATUS_IS_OK(status)) {
 940                 TALLOC_FREE(frame);
 941                 return status;
 942         }
 943
 944         psd->revision = orig_psd->revision;
 945         if (security_info_sent & SECINFO_DACL) {
 946                 psd->type = orig_psd->type;
 947                 /* All our SD's are self relative. */
 948                 psd->type |= SEC_DESC_SELF_RELATIVE;
 949         }
 950
 951         if ((security_info_sent & SECINFO_OWNER) && (orig_psd->owner_sid != NULL)) {
 952                 if (!dom_sid_equal(orig_psd->owner_sid, psd->owner_sid)) {
 953                         /* We're changing the owner. */
 954                         chown_needed = true;
 955                 }
 956                 psd->owner_sid = orig_psd->owner_sid;
 957         }
 958         if ((security_info_sent & SECINFO_GROUP) && (orig_psd->group_sid != NULL)) {
 959                 if (!dom_sid_equal(orig_psd->group_sid, psd->group_sid)) {
 960                         /* We're changing the group. */
 961                         chown_needed = true;
 962                 }
 963                 psd->group_sid = orig_psd->group_sid;
 964         }
 965         if (security_info_sent & SECINFO_DACL) {
 966                 if (security_descriptor_with_ms_nfs(orig_psd)) {
 967                         /*
 968                          * If the sd contains a MS NFS SID, do
 969                          * nothing, it's a chmod() request from OS X
 970                          * with AAPL context.
 971                          */
 972                         TALLOC_FREE(frame);
 973                         return NT_STATUS_OK;
 974                 }
 975                 psd->dacl = orig_psd->dacl;
 976                 psd->type |= SEC_DESC_DACL_PRESENT;
 977         }
 978         if (security_info_sent & SECINFO_SACL) {
 979                 psd->sacl = orig_psd->sacl;
 980                 psd->type |= SEC_DESC_SACL_PRESENT;
 981         }
 982
 983         if (ignore_file_system_acl) {
 984                 if (chown_needed) {
 985                         /* send only ownership stuff to lower layer */
 986                         security_info_sent &= (SECINFO_OWNER | SECINFO_GROUP);
 987                         status = set_underlying_acl(handle, fsp, psd,
 988                                                     security_info_sent, true);
 989                         if (!NT_STATUS_IS_OK(status)) {
 990                                 TALLOC_FREE(frame);
 991                                 return status;
 992                         }
 993                 }
 994                 ZERO_ARRAY(hash);
 995                 status = store_v3_blob(store_acl_blob_fsp_fn, handle, fsp, psd,
 996                                        NULL, hash);
 997
 998                 TALLOC_FREE(frame);
 999                 return status;
1000         }
1001
1002         status = set_underlying_acl(handle, fsp, psd, security_info_sent,
1003                                     chown_needed);
1004         if (!NT_STATUS_IS_OK(status)) {
1005                 TALLOC_FREE(frame);
1006                 return status;
1007         }
1008
1009         /* Get the full underlying sd, then hash. */
1010         status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
1011                                           fsp,
1012                                           HASH_SECURITY_INFO,
1013                                           frame,
1014                                           &pdesc_next);
1015
1016         if (!NT_STATUS_IS_OK(status)) {
1017                 TALLOC_FREE(frame);
1018                 return status;
1019         }
1020
1021         status = hash_sd_sha256(pdesc_next, hash);
1022         if (!NT_STATUS_IS_OK(status)) {
1023                 TALLOC_FREE(frame);
1024                 return status;
1025         }
1026
1027         /* Get the full underlying sd, then hash. */
1028         ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FD(handle,
1029                                                fsp,
1030                                                frame,
1031                                                &sys_acl_description,
1032                                                &sys_acl_blob);
1033
1034         /* If we fail to get the ACL blob (for some reason) then this
1035          * is not fatal, we just work based on the NT ACL only */
1036         if (ret != 0) {
1037                 status = store_v3_blob(store_acl_blob_fsp_fn, handle, fsp, psd,
1038                                        pdesc_next, hash);
1039
1040                 TALLOC_FREE(frame);
1041                 return status;
1042         }
1043
1044         status = hash_blob_sha256(sys_acl_blob, sys_acl_hash);
1045         if (!NT_STATUS_IS_OK(status)) {
1046                 TALLOC_FREE(frame);
1047                 return status;
1048         }
1049
1050         if (DEBUGLEVEL >= 10) {
1051                 DBG_DEBUG("storing xattr sd for file %s based on system ACL\n",
1052                           fsp_str_dbg(fsp));
1053                 NDR_PRINT_DEBUG(security_descriptor,
1054                                 discard_const_p(struct security_descriptor, psd));
1055
1056                 DBG_DEBUG("storing hash in xattr sd based on system ACL and:\n");
1057                 NDR_PRINT_DEBUG(security_descriptor,
1058                                 discard_const_p(struct security_descriptor, pdesc_next));
1059         }
1060
1061         /* We store hashes of both the sys ACL blob and the NT
1062          * security desciptor mapped from that ACL so as to improve
1063          * our chances against some inadvertant change breaking the
1064          * hash used */
1065         status = create_sys_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash,
1066                                      sys_acl_description, sys_acl_hash);
1067         if (!NT_STATUS_IS_OK(status)) {
1068                 DBG_DEBUG("create_sys_acl_blob failed\n");
1069                 TALLOC_FREE(frame);
1070                 return status;
1071         }
1072
1073         status = store_acl_blob_fsp_fn(handle, fsp, &blob);
1074
1075         TALLOC_FREE(frame);
1076         return status;
1077 }
1078
1079 static int acl_common_remove_object(vfs_handle_struct *handle,
1080                                         const struct smb_filename *smb_fname,
1081                                         bool is_directory)
1082 {
1083         connection_struct *conn = handle->conn;
1084         struct file_id id;
1085         files_struct *fsp = NULL;
1086         int ret = 0;
1087         char *parent_dir = NULL;
1088         const char *final_component = NULL;
1089         struct smb_filename local_fname = {0};
1090         struct smb_filename parent_dir_fname = {0};
1091         int saved_errno = 0;
1092         struct smb_filename *saved_dir_fname = NULL;
1093
1094         saved_dir_fname = vfs_GetWd(talloc_tos(),conn);
1095         if (saved_dir_fname == NULL) {
1096                 saved_errno = errno;
1097                 goto out;
1098         }
1099
1100         if (!parent_dirname(talloc_tos(), smb_fname->base_name,
1101                         &parent_dir, &final_component)) {
1102                 saved_errno = ENOMEM;
1103                 goto out;
1104         }
1105
1106         DBG_DEBUG("removing %s %s/%s\n", is_directory ? "directory" : "file",
1107                   parent_dir, final_component);
1108
1109         parent_dir_fname = (struct smb_filename) { .base_name = parent_dir };
1110
1111         /* cd into the parent dir to pin it. */
1112         ret = vfs_ChDir(conn, &parent_dir_fname);
1113         if (ret == -1) {
1114                 saved_errno = errno;
1115                 goto out;
1116         }
1117
1118         local_fname.base_name = discard_const_p(char, final_component);
1119
1120         /* Must use lstat here. */
1121         ret = SMB_VFS_LSTAT(conn, &local_fname);
1122         if (ret == -1) {
1123                 saved_errno = errno;
1124                 goto out;
1125         }
1126
1127         /* Ensure we have this file open with DELETE access. */
1128         id = vfs_file_id_from_sbuf(conn, &local_fname.st);
1129         for (fsp = file_find_di_first(conn->sconn, id); fsp;
1130                      fsp = file_find_di_next(fsp)) {
1131                 if (fsp->access_mask & DELETE_ACCESS &&
1132                                 fsp->delete_on_close) {
1133                         /* We did open this for delete,
1134                          * allow the delete as root.
1135                          */
1136                         break;
1137                 }
1138         }
1139
1140         if (!fsp) {
1141                 DBG_DEBUG("%s %s/%s not an open file\n",
1142                           is_directory ? "directory" : "file",
1143                           parent_dir, final_component);
1144                 saved_errno = EACCES;
1145                 goto out;
1146         }
1147
1148         become_root();
1149         if (is_directory) {
1150                 ret = SMB_VFS_NEXT_RMDIR(handle, &local_fname);
1151         } else {
1152                 ret = SMB_VFS_NEXT_UNLINK(handle, &local_fname);
1153         }
1154         unbecome_root();
1155
1156         if (ret == -1) {
1157                 saved_errno = errno;
1158         }
1159
1160   out:
1161
1162         TALLOC_FREE(parent_dir);
1163
1164         if (saved_dir_fname) {
1165                 vfs_ChDir(conn, saved_dir_fname);
1166                 TALLOC_FREE(saved_dir_fname);
1167         }
1168         if (saved_errno) {
1169                 errno = saved_errno;
1170         }
1171         return ret;
1172 }
1173
1174 int rmdir_acl_common(struct vfs_handle_struct *handle,
1175                      const struct smb_filename *smb_fname)
1176 {
1177         int ret;
1178
1179         /* Try the normal rmdir first. */
1180         ret = SMB_VFS_NEXT_RMDIR(handle, smb_fname);
1181         if (ret == 0) {
1182                 return 0;
1183         }
1184         if (errno == EACCES || errno == EPERM) {
1185                 /* Failed due to access denied,
1186                    see if we need to root override. */
1187                 return acl_common_remove_object(handle,
1188                                                 smb_fname,
1189                                                 true);
1190         }
1191
1192         DBG_DEBUG("unlink of %s failed %s\n",
1193                   smb_fname->base_name,
1194                   strerror(errno));
1195         return -1;
1196 }
1197
1198 int unlink_acl_common(struct vfs_handle_struct *handle,
1199                         const struct smb_filename *smb_fname)
1200 {
1201         int ret;
1202
1203         /* Try the normal unlink first. */
1204         ret = SMB_VFS_NEXT_UNLINK(handle, smb_fname);
1205         if (ret == 0) {
1206                 return 0;
1207         }
1208         if (errno == EACCES || errno == EPERM) {
1209                 /* Failed due to access denied,
1210                    see if we need to root override. */
1211
1212                 /* Don't do anything fancy for streams. */
1213                 if (smb_fname->stream_name) {
1214                         return -1;
1215                 }
1216                 return acl_common_remove_object(handle,
1217                                         smb_fname,
1218                                         false);
1219         }
1220
1221         DBG_DEBUG("unlink of %s failed %s\n",
1222                   smb_fname->base_name,
1223                   strerror(errno));
1224         return -1;
1225 }
1226
1227 int chmod_acl_module_common(struct vfs_handle_struct *handle,
1228                             const struct smb_filename *smb_fname,
1229                             mode_t mode)
1230 {
1231         if (smb_fname->flags & SMB_FILENAME_POSIX_PATH) {
1232                 /* Only allow this on POSIX pathnames. */
1233                 return SMB_VFS_NEXT_CHMOD(handle, smb_fname, mode);
1234         }
1235         return 0;
1236 }
1237
1238 int fchmod_acl_module_common(struct vfs_handle_struct *handle,
1239                              struct files_struct *fsp, mode_t mode)
1240 {
1241         if (fsp->posix_flags & FSP_POSIX_FLAGS_OPEN) {
1242                 /* Only allow this on POSIX opens. */
1243                 return SMB_VFS_NEXT_FCHMOD(handle, fsp, mode);
1244         }
1245         return 0;
1246 }
1247
1248 int fchmod_acl_acl_module_common(struct vfs_handle_struct *handle,
1249                                  struct files_struct *fsp, mode_t mode)
1250 {
1251         if (fsp->posix_flags & FSP_POSIX_FLAGS_OPEN) {
1252                 /* Only allow this on POSIX opens. */
1253                 return SMB_VFS_NEXT_FCHMOD_ACL(handle, fsp, mode);
1254         }
1255         return 0;
1256 }