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 struct smb_filename *smb_fname,
 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         const char *name = NULL;
 385         bool ignore_file_system_acl = lp_parm_bool(SNUM(handle->conn),
 386                                                 ACL_MODULE_NAME,
 387                                                 "ignore system acls",
 388                                                 false);
 389         TALLOC_CTX *frame = talloc_stackframe();
 390
 391         if (fsp && smb_fname == NULL) {
 392                 name = fsp->fsp_name->base_name;
 393         } else {
 394                 name = smb_fname->base_name;
 395         }
 396
 397         DEBUG(10, ("get_nt_acl_internal: name=%s\n", name));
 398
 399         status = get_acl_blob(frame, handle, fsp, name, &blob);
 400         if (!NT_STATUS_IS_OK(status)) {
 401                 DEBUG(10, ("get_nt_acl_internal: get_acl_blob returned %s\n",
 402                         nt_errstr(status)));
 403                 psd = NULL;
 404                 goto out;
 405         } else {
 406                 status = parse_acl_blob(&blob, mem_ctx, &psd,
 407                                         &hash_type, &xattr_version, &hash[0], &sys_acl_hash[0]);
 408                 if (!NT_STATUS_IS_OK(status)) {
 409                         DEBUG(10, ("parse_acl_blob returned %s\n",
 410                                    nt_errstr(status)));
 411                         psd = NULL;
 412                         goto out;
 413                 }
 414         }
 415
 416         /* Ensure we don't leak psd if we don't choose it.
 417          *
 418          * We don't allocate it onto frame as it is preferred not to
 419          * steal from a talloc pool.
 420          */
 421         talloc_steal(frame, psd);
 422
 423         /* determine which type of xattr we got */
 424         switch (xattr_version) {
 425         case 1:
 426         case 2:
 427                 /* These xattr types are unilatteral, they do not
 428                  * require confirmation of the hash.  In particular,
 429                  * the NTVFS file server uses version 1, but
 430                  * 'samba-tool ntacl' can set these as well */
 431                 goto out;
 432         case 3:
 433         case 4:
 434                 if (ignore_file_system_acl) {
 435                         goto out;
 436                 }
 437
 438                 break;
 439         default:
 440                 DEBUG(10, ("get_nt_acl_internal: ACL blob revision "
 441                            "mismatch (%u) for file %s\n",
 442                            (unsigned int)hash_type,
 443                            name));
 444                 TALLOC_FREE(psd);
 445                 psd = NULL;
 446                 goto out;
 447         }
 448
 449         /* determine which type of xattr we got */
 450         if (hash_type != XATTR_SD_HASH_TYPE_SHA256) {
 451                 DEBUG(10, ("get_nt_acl_internal: ACL blob hash type "
 452                            "(%u) unexpected for file %s\n",
 453                            (unsigned int)hash_type,
 454                            name));
 455                 TALLOC_FREE(psd);
 456                 psd = NULL;
 457                 goto out;
 458         }
 459
 460         /* determine which type of xattr we got */
 461         switch (xattr_version) {
 462         case 4:
 463         {
 464                 int ret;
 465                 char *sys_acl_blob_description;
 466                 DATA_BLOB sys_acl_blob;
 467                 if (fsp) {
 468                         /* Get the full underlying sd, then hash. */
 469                         ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FD(handle,
 470                                                                fsp,
 471                                                                frame,
 472                                                                &sys_acl_blob_description,
 473                                                                &sys_acl_blob);
 474                 } else {
 475                         /* Get the full underlying sd, then hash. */
 476                         ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FILE(handle,
 477                                                                  name,
 478                                                                  frame,
 479                                                                  &sys_acl_blob_description,
 480                                                                  &sys_acl_blob);
 481                 }
 482
 483                 /* If we fail to get the ACL blob (for some reason) then this
 484                  * is not fatal, we just work based on the NT ACL only */
 485                 if (ret == 0) {
 486                         status = hash_blob_sha256(sys_acl_blob, sys_acl_hash_tmp);
 487                         if (!NT_STATUS_IS_OK(status)) {
 488                                 TALLOC_FREE(frame);
 489                                 return status;
 490                         }
 491
 492                         if (memcmp(&sys_acl_hash[0], &sys_acl_hash_tmp[0],
 493                                    XATTR_SD_HASH_SIZE) == 0) {
 494                                 /* Hash matches, return blob sd. */
 495                                 DEBUG(10, ("get_nt_acl_internal: blob hash "
 496                                            "matches for file %s\n",
 497                                            name ));
 498                                 goto out;
 499                         }
 500                 }
 501
 502                 /* Otherwise, fall though and see if the NT ACL hash matches */
 503         }
 504         case 3:
 505                 /* Get the full underlying sd for the hash
 506                    or to return as backup. */
 507                 if (fsp) {
 508                         status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
 509                                                           fsp,
 510                                                           HASH_SECURITY_INFO,
 511                                                           mem_ctx,
 512                                                           &pdesc_next);
 513                 } else {
 514                         status = SMB_VFS_NEXT_GET_NT_ACL(handle,
 515                                                          smb_fname,
 516                                                          HASH_SECURITY_INFO,
 517                                                          mem_ctx,
 518                                                          &pdesc_next);
 519                 }
 520
 521                 if (!NT_STATUS_IS_OK(status)) {
 522                         DEBUG(10, ("get_nt_acl_internal: get_next_acl for file %s "
 523                                    "returned %s\n",
 524                                    name,
 525                                    nt_errstr(status)));
 526                         TALLOC_FREE(frame);
 527                         return status;
 528                 }
 529
 530                 /* Ensure we don't leak psd_next if we don't choose it.
 531                  *
 532                  * We don't allocate it onto frame as it is preferred not to
 533                  * steal from a talloc pool.
 534                  */
 535                 talloc_steal(frame, pdesc_next);
 536
 537                 status = hash_sd_sha256(pdesc_next, hash_tmp);
 538                 if (!NT_STATUS_IS_OK(status)) {
 539                         TALLOC_FREE(psd);
 540                         psd = pdesc_next;
 541                         goto out;
 542                 }
 543
 544                 if (memcmp(&hash[0], &hash_tmp[0], XATTR_SD_HASH_SIZE) == 0) {
 545                         /* Hash matches, return blob sd. */
 546                         DEBUG(10, ("get_nt_acl_internal: blob hash "
 547                                    "matches for file %s\n",
 548                                    name ));
 549                         goto out;
 550                 }
 551
 552                 /* Hash doesn't match, return underlying sd. */
 553                 DEBUG(10, ("get_nt_acl_internal: blob hash "
 554                            "does not match for file %s - returning "
 555                            "file system SD mapping.\n",
 556                            name ));
 557
 558                 if (DEBUGLEVEL >= 10) {
 559                         DEBUG(10,("get_nt_acl_internal: acl for blob hash for %s is:\n",
 560                                   name ));
 561                         NDR_PRINT_DEBUG(security_descriptor, pdesc_next);
 562                 }
 563
 564                 TALLOC_FREE(psd);
 565                 psd = pdesc_next;
 566         }
 567   out:
 568
 569         if (psd == NULL) {
 570                 /* Get the full underlying sd, as we failed to get the
 571                  * blob for the hash, or the revision/hash type wasn't
 572                  * known */
 573                 if (fsp) {
 574                         status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
 575                                                           fsp,
 576                                                           security_info,
 577                                                           mem_ctx,
 578                                                           &pdesc_next);
 579                 } else {
 580                         status = SMB_VFS_NEXT_GET_NT_ACL(handle,
 581                                                          smb_fname,
 582                                                          security_info,
 583                                                          mem_ctx,
 584                                                          &pdesc_next);
 585                 }
 586
 587                 if (!NT_STATUS_IS_OK(status)) {
 588                         DEBUG(10, ("get_nt_acl_internal: get_next_acl for file %s "
 589                                    "returned %s\n",
 590                                    name,
 591                                    nt_errstr(status)));
 592                         TALLOC_FREE(frame);
 593                         return status;
 594                 }
 595
 596                 /* Ensure we don't leak psd_next if we don't choose it.
 597                  *
 598                  * We don't allocate it onto frame as it is preferred not to
 599                  * steal from a talloc pool.
 600                  */
 601                 talloc_steal(frame, pdesc_next);
 602                 psd = pdesc_next;
 603         }
 604
 605         if (psd != pdesc_next) {
 606                 /* We're returning the blob, throw
 607                  * away the filesystem SD. */
 608                 TALLOC_FREE(pdesc_next);
 609         } else {
 610                 SMB_STRUCT_STAT sbuf;
 611                 SMB_STRUCT_STAT *psbuf = &sbuf;
 612                 bool is_directory = false;
 613                 /*
 614                  * We're returning the underlying ACL from the
 615                  * filesystem. If it's a directory, and has no
 616                  * inheritable ACE entries we have to fake them.
 617                  */
 618                 if (fsp) {
 619                         status = vfs_stat_fsp(fsp);
 620                         if (!NT_STATUS_IS_OK(status)) {
 621                                 TALLOC_FREE(frame);
 622                                 return status;
 623                         }
 624                         psbuf = &fsp->fsp_name->st;
 625                 } else {
 626                         /*
 627                          * https://bugzilla.samba.org/show_bug.cgi?id=11249
 628                          *
 629                          * We are currently guaranteed that 'name' here is
 630                          * a smb_fname->base_name, which *cannot* contain
 631                          * a stream name (':'). vfs_stat_smb_fname() splits
 632                          * a name into a base name + stream name, which
 633                          * when we get here we know we've already done.
 634                          * So we have to call the stat or lstat VFS
 635                          * calls directly here. Else, a base_name that
 636                          * contains a ':' (from a demangled name) will
 637                          * get split again.
 638                          *
 639                          * FIXME.
 640                          * This uglyness will go away once smb_fname
 641                          * is fully plumbed through the VFS.
 642                          */
 643                         int ret = vfs_stat_smb_basename(handle->conn,
 644                                                 name,
 645                                                 &sbuf);
 646                         if (ret == -1) {
 647                                 TALLOC_FREE(frame);
 648                                 return map_nt_error_from_unix(errno);
 649                         }
 650                 }
 651                 is_directory = S_ISDIR(psbuf->st_ex_mode);
 652
 653                 if (ignore_file_system_acl) {
 654                         TALLOC_FREE(pdesc_next);
 655                         status = make_default_filesystem_acl(mem_ctx,
 656                                                 name,
 657                                                 psbuf,
 658                                                 &psd);
 659                         if (!NT_STATUS_IS_OK(status)) {
 660                                 TALLOC_FREE(frame);
 661                                 return status;
 662                         }
 663                 } else {
 664                         if (is_directory &&
 665                                 !sd_has_inheritable_components(psd,
 666                                                         true)) {
 667                                 status = add_directory_inheritable_components(
 668                                                         handle,
 669                                                         name,
 670                                                         psbuf,
 671                                                         psd);
 672                                 if (!NT_STATUS_IS_OK(status)) {
 673                                         TALLOC_FREE(frame);
 674                                         return status;
 675                                 }
 676                         }
 677                         /* The underlying POSIX module always sets
 678                            the ~SEC_DESC_DACL_PROTECTED bit, as ACLs
 679                            can't be inherited in this way under POSIX.
 680                            Remove it for Windows-style ACLs. */
 681                         psd->type &= ~SEC_DESC_DACL_PROTECTED;
 682                 }
 683         }
 684
 685         if (!(security_info & SECINFO_OWNER)) {
 686                 psd->owner_sid = NULL;
 687         }
 688         if (!(security_info & SECINFO_GROUP)) {
 689                 psd->group_sid = NULL;
 690         }
 691         if (!(security_info & SECINFO_DACL)) {
 692                 psd->type &= ~SEC_DESC_DACL_PRESENT;
 693                 psd->dacl = NULL;
 694         }
 695         if (!(security_info & SECINFO_SACL)) {
 696                 psd->type &= ~SEC_DESC_SACL_PRESENT;
 697                 psd->sacl = NULL;
 698         }
 699
 700         TALLOC_FREE(blob.data);
 701
 702         if (DEBUGLEVEL >= 10) {
 703                 DEBUG(10,("get_nt_acl_internal: returning acl for %s is:\n",
 704                         name ));
 705                 NDR_PRINT_DEBUG(security_descriptor, psd);
 706         }
 707
 708         /* The VFS API is that the ACL is expected to be on mem_ctx */
 709         *ppdesc = talloc_move(mem_ctx, &psd);
 710
 711         TALLOC_FREE(frame);
 712         return NT_STATUS_OK;
 713 }
 714
 715 /*********************************************************************
 716  Fetch a security descriptor given an fsp.
 717 *********************************************************************/
 718
 719 static NTSTATUS fget_nt_acl_common(vfs_handle_struct *handle,
 720                                    files_struct *fsp,
 721                                    uint32_t security_info,
 722                                    TALLOC_CTX *mem_ctx,
 723                                    struct security_descriptor **ppdesc)
 724 {
 725         return get_nt_acl_internal(handle, fsp,
 726                                    NULL, security_info, mem_ctx, ppdesc);
 727 }
 728
 729 /*********************************************************************
 730  Fetch a security descriptor given a pathname.
 731 *********************************************************************/
 732
 733 static NTSTATUS get_nt_acl_common(vfs_handle_struct *handle,
 734                                   const struct smb_filename *smb_fname,
 735                                   uint32_t security_info,
 736                                   TALLOC_CTX *mem_ctx,
 737                                   struct security_descriptor **ppdesc)
 738 {
 739         return get_nt_acl_internal(handle,
 740                                 NULL,
 741                                 smb_fname,
 742                                 security_info,
 743                                 mem_ctx,
 744                                 ppdesc);
 745 }
 746
 747 /*********************************************************************
 748  Store a security descriptor given an fsp.
 749 *********************************************************************/
 750
 751 static NTSTATUS fset_nt_acl_common(vfs_handle_struct *handle, files_struct *fsp,
 752         uint32_t security_info_sent, const struct security_descriptor *orig_psd)
 753 {
 754         NTSTATUS status;
 755         int ret;
 756         DATA_BLOB blob, sys_acl_blob;
 757         struct security_descriptor *pdesc_next = NULL;
 758         struct security_descriptor *psd = NULL;
 759         uint8_t hash[XATTR_SD_HASH_SIZE];
 760         uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE];
 761         bool chown_needed = false;
 762         char *sys_acl_description;
 763         TALLOC_CTX *frame = talloc_stackframe();
 764
 765         if (DEBUGLEVEL >= 10) {
 766                 DEBUG(10,("fset_nt_acl_xattr: incoming sd for file %s\n",
 767                           fsp_str_dbg(fsp)));
 768                 NDR_PRINT_DEBUG(security_descriptor,
 769                         discard_const_p(struct security_descriptor, orig_psd));
 770         }
 771
 772         status = get_nt_acl_internal(handle, fsp,
 773                         NULL,
 774                         SECINFO_OWNER|SECINFO_GROUP|SECINFO_DACL|SECINFO_SACL,
 775                                      frame,
 776                         &psd);
 777
 778         if (!NT_STATUS_IS_OK(status)) {
 779                 TALLOC_FREE(frame);
 780                 return status;
 781         }
 782
 783         psd->revision = orig_psd->revision;
 784         /* All our SD's are self relative. */
 785         psd->type = orig_psd->type | SEC_DESC_SELF_RELATIVE;
 786
 787         if ((security_info_sent & SECINFO_OWNER) && (orig_psd->owner_sid != NULL)) {
 788                 if (!dom_sid_equal(orig_psd->owner_sid, psd->owner_sid)) {
 789                         /* We're changing the owner. */
 790                         chown_needed = true;
 791                 }
 792                 psd->owner_sid = orig_psd->owner_sid;
 793         }
 794         if ((security_info_sent & SECINFO_GROUP) && (orig_psd->group_sid != NULL)) {
 795                 if (!dom_sid_equal(orig_psd->group_sid, psd->group_sid)) {
 796                         /* We're changing the group. */
 797                         chown_needed = true;
 798                 }
 799                 psd->group_sid = orig_psd->group_sid;
 800         }
 801         if (security_info_sent & SECINFO_DACL) {
 802                 if (security_descriptor_with_ms_nfs(orig_psd)) {
 803                         /*
 804                          * If the sd contains a MS NFS SID, do
 805                          * nothing, it's a chmod() request from OS X
 806                          * with AAPL context.
 807                          */
 808                         TALLOC_FREE(frame);
 809                         return NT_STATUS_OK;
 810                 }
 811                 psd->dacl = orig_psd->dacl;
 812                 psd->type |= SEC_DESC_DACL_PRESENT;
 813         }
 814         if (security_info_sent & SECINFO_SACL) {
 815                 psd->sacl = orig_psd->sacl;
 816                 psd->type |= SEC_DESC_SACL_PRESENT;
 817         }
 818
 819         status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp, security_info_sent, psd);
 820         if (!NT_STATUS_IS_OK(status)) {
 821                 if (!NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) {
 822                         TALLOC_FREE(frame);
 823                         return status;
 824                 }
 825                 /* We got access denied here. If we're already root,
 826                    or we didn't need to do a chown, or the fsp isn't
 827                    open with WRITE_OWNER access, just return. */
 828                 if (get_current_uid(handle->conn) == 0 ||
 829                                 chown_needed == false ||
 830                                 !(fsp->access_mask & SEC_STD_WRITE_OWNER)) {
 831                         TALLOC_FREE(frame);
 832                         return NT_STATUS_ACCESS_DENIED;
 833                 }
 834
 835                 DEBUG(10,("fset_nt_acl_common: overriding chown on file %s "
 836                         "for sid %s\n",
 837                         fsp_str_dbg(fsp),
 838                         sid_string_tos(psd->owner_sid)
 839                         ));
 840
 841                 /* Ok, we failed to chown and we have
 842                    SEC_STD_WRITE_OWNER access - override. */
 843                 become_root();
 844                 status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp,
 845                                 security_info_sent, psd);
 846                 unbecome_root();
 847                 if (!NT_STATUS_IS_OK(status)) {
 848                         TALLOC_FREE(frame);
 849                         return status;
 850                 }
 851         }
 852
 853         /* Get the full underlying sd, then hash. */
 854         status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
 855                                           fsp,
 856                                           HASH_SECURITY_INFO,
 857                                           frame,
 858                                           &pdesc_next);
 859
 860         if (!NT_STATUS_IS_OK(status)) {
 861                 TALLOC_FREE(frame);
 862                 return status;
 863         }
 864
 865         status = hash_sd_sha256(pdesc_next, hash);
 866         if (!NT_STATUS_IS_OK(status)) {
 867                 TALLOC_FREE(frame);
 868                 return status;
 869         }
 870
 871         /* Get the full underlying sd, then hash. */
 872         ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FD(handle,
 873                                                fsp,
 874                                                frame,
 875                                                &sys_acl_description,
 876                                                &sys_acl_blob);
 877
 878         /* If we fail to get the ACL blob (for some reason) then this
 879          * is not fatal, we just work based on the NT ACL only */
 880         if (ret != 0) {
 881                 if (DEBUGLEVEL >= 10) {
 882                         DEBUG(10,("fset_nt_acl_xattr: storing xattr sd for file %s\n",
 883                                   fsp_str_dbg(fsp)));
 884                         NDR_PRINT_DEBUG(security_descriptor,
 885                                         discard_const_p(struct security_descriptor, psd));
 886
 887                         DEBUG(10,("fset_nt_acl_xattr: storing has in xattr sd based on \n"));
 888                         NDR_PRINT_DEBUG(security_descriptor,
 889                                         discard_const_p(struct security_descriptor, pdesc_next));
 890                 }
 891                 status = create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash);
 892                 if (!NT_STATUS_IS_OK(status)) {
 893                         DEBUG(10, ("fset_nt_acl_xattr: create_acl_blob failed\n"));
 894                         TALLOC_FREE(frame);
 895                         return status;
 896                 }
 897
 898                 status = store_acl_blob_fsp(handle, fsp, &blob);
 899
 900                 TALLOC_FREE(frame);
 901                 return status;
 902         }
 903
 904         status = hash_blob_sha256(sys_acl_blob, sys_acl_hash);
 905         if (!NT_STATUS_IS_OK(status)) {
 906                 TALLOC_FREE(frame);
 907                 return status;
 908         }
 909
 910         if (DEBUGLEVEL >= 10) {
 911                 DEBUG(10,("fset_nt_acl_xattr: storing xattr sd for file %s based on system ACL\n",
 912                           fsp_str_dbg(fsp)));
 913                 NDR_PRINT_DEBUG(security_descriptor,
 914                                 discard_const_p(struct security_descriptor, psd));
 915
 916                 DEBUG(10,("fset_nt_acl_xattr: storing hash in xattr sd based on system ACL and:\n"));
 917                 NDR_PRINT_DEBUG(security_descriptor,
 918                                 discard_const_p(struct security_descriptor, pdesc_next));
 919         }
 920
 921         /* We store hashes of both the sys ACL blob and the NT
 922          * security desciptor mapped from that ACL so as to improve
 923          * our chances against some inadvertant change breaking the
 924          * hash used */
 925         status = create_sys_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash,
 926                                      sys_acl_description, sys_acl_hash);
 927         if (!NT_STATUS_IS_OK(status)) {
 928                 DEBUG(10, ("fset_nt_acl_xattr: create_sys_acl_blob failed\n"));
 929                 TALLOC_FREE(frame);
 930                 return status;
 931         }
 932
 933         status = store_acl_blob_fsp(handle, fsp, &blob);
 934
 935         TALLOC_FREE(frame);
 936         return status;
 937 }
 938
 939 static int acl_common_remove_object(vfs_handle_struct *handle,
 940                                         const char *path,
 941                                         bool is_directory)
 942 {
 943         connection_struct *conn = handle->conn;
 944         struct file_id id;
 945         files_struct *fsp = NULL;
 946         int ret = 0;
 947         char *parent_dir = NULL;
 948         const char *final_component = NULL;
 949         struct smb_filename local_fname;
 950         int saved_errno = 0;
 951         char *saved_dir = NULL;
 952
 953         saved_dir = vfs_GetWd(talloc_tos(),conn);
 954         if (!saved_dir) {
 955                 saved_errno = errno;
 956                 goto out;
 957         }
 958
 959         if (!parent_dirname(talloc_tos(), path,
 960                         &parent_dir, &final_component)) {
 961                 saved_errno = ENOMEM;
 962                 goto out;
 963         }
 964
 965         DEBUG(10,("acl_common_remove_object: removing %s %s/%s\n",
 966                 is_directory ? "directory" : "file",
 967                 parent_dir, final_component ));
 968
 969         /* cd into the parent dir to pin it. */
 970         ret = vfs_ChDir(conn, parent_dir);
 971         if (ret == -1) {
 972                 saved_errno = errno;
 973                 goto out;
 974         }
 975
 976         ZERO_STRUCT(local_fname);
 977         local_fname.base_name = discard_const_p(char, final_component);
 978
 979         /* Must use lstat here. */
 980         ret = SMB_VFS_LSTAT(conn, &local_fname);
 981         if (ret == -1) {
 982                 saved_errno = errno;
 983                 goto out;
 984         }
 985
 986         /* Ensure we have this file open with DELETE access. */
 987         id = vfs_file_id_from_sbuf(conn, &local_fname.st);
 988         for (fsp = file_find_di_first(conn->sconn, id); fsp;
 989                      fsp = file_find_di_next(fsp)) {
 990                 if (fsp->access_mask & DELETE_ACCESS &&
 991                                 fsp->delete_on_close) {
 992                         /* We did open this for delete,
 993                          * allow the delete as root.
 994                          */
 995                         break;
 996                 }
 997         }
 998
 999         if (!fsp) {
1000                 DEBUG(10,("acl_common_remove_object: %s %s/%s "
1001                         "not an open file\n",
1002                         is_directory ? "directory" : "file",
1003                         parent_dir, final_component ));
1004                 saved_errno = EACCES;
1005                 goto out;
1006         }
1007
1008         become_root();
1009         if (is_directory) {
1010                 ret = SMB_VFS_NEXT_RMDIR(handle, final_component);
1011         } else {
1012                 ret = SMB_VFS_NEXT_UNLINK(handle, &local_fname);
1013         }
1014         unbecome_root();
1015
1016         if (ret == -1) {
1017                 saved_errno = errno;
1018         }
1019
1020   out:
1021
1022         TALLOC_FREE(parent_dir);
1023
1024         if (saved_dir) {
1025                 vfs_ChDir(conn, saved_dir);
1026         }
1027         if (saved_errno) {
1028                 errno = saved_errno;
1029         }
1030         return ret;
1031 }
1032
1033 static int rmdir_acl_common(struct vfs_handle_struct *handle,
1034                                 const char *path)
1035 {
1036         int ret;
1037
1038         /* Try the normal rmdir first. */
1039         ret = SMB_VFS_NEXT_RMDIR(handle, path);
1040         if (ret == 0) {
1041                 return 0;
1042         }
1043         if (errno == EACCES || errno == EPERM) {
1044                 /* Failed due to access denied,
1045                    see if we need to root override. */
1046                 return acl_common_remove_object(handle,
1047                                                 path,
1048                                                 true);
1049         }
1050
1051         DEBUG(10,("rmdir_acl_common: unlink of %s failed %s\n",
1052                 path,
1053                 strerror(errno) ));
1054         return -1;
1055 }
1056
1057 static int unlink_acl_common(struct vfs_handle_struct *handle,
1058                         const struct smb_filename *smb_fname)
1059 {
1060         int ret;
1061
1062         /* Try the normal unlink first. */
1063         ret = SMB_VFS_NEXT_UNLINK(handle, smb_fname);
1064         if (ret == 0) {
1065                 return 0;
1066         }
1067         if (errno == EACCES || errno == EPERM) {
1068                 /* Failed due to access denied,
1069                    see if we need to root override. */
1070
1071                 /* Don't do anything fancy for streams. */
1072                 if (smb_fname->stream_name) {
1073                         return -1;
1074                 }
1075                 return acl_common_remove_object(handle,
1076                                         smb_fname->base_name,
1077                                         false);
1078         }
1079
1080         DEBUG(10,("unlink_acl_common: unlink of %s failed %s\n",
1081                 smb_fname->base_name,
1082                 strerror(errno) ));
1083         return -1;
1084 }
1085
1086 static int chmod_acl_module_common(struct vfs_handle_struct *handle,
1087                         const char *path, mode_t mode)
1088 {
1089         if (lp_posix_pathnames()) {
1090                 /* Only allow this on POSIX pathnames. */
1091                 return SMB_VFS_NEXT_CHMOD(handle, path, mode);
1092         }
1093         return 0;
1094 }
1095
1096 static int fchmod_acl_module_common(struct vfs_handle_struct *handle,
1097                         struct files_struct *fsp, mode_t mode)
1098 {
1099         if (fsp->posix_flags & FSP_POSIX_FLAGS_OPEN) {
1100                 /* Only allow this on POSIX opens. */
1101                 return SMB_VFS_NEXT_FCHMOD(handle, fsp, mode);
1102         }
1103         return 0;
1104 }
1105
1106 static int chmod_acl_acl_module_common(struct vfs_handle_struct *handle,
1107                         const char *name, mode_t mode)
1108 {
1109         if (lp_posix_pathnames()) {
1110                 /* Only allow this on POSIX pathnames. */
1111                 return SMB_VFS_NEXT_CHMOD_ACL(handle, name, mode);
1112         }
1113         return 0;
1114 }
1115
1116 static int fchmod_acl_acl_module_common(struct vfs_handle_struct *handle,
1117                         struct files_struct *fsp, mode_t mode)
1118 {
1119         if (fsp->posix_flags & FSP_POSIX_FLAGS_OPEN) {
1120                 /* Only allow this on POSIX opens. */
1121                 return SMB_VFS_NEXT_FCHMOD_ACL(handle, fsp, mode);
1122         }
1123         return 0;
1124 }