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         } else {
 347                 psd->dacl = make_sec_acl(psd,
 348                                 NT4_ACL_REVISION,
 349                                 3,
 350                                 new_ace_list);
 351                 if (psd->dacl == NULL) {
 352                         return NT_STATUS_NO_MEMORY;
 353                 }
 354         }
 355         return NT_STATUS_OK;
 356 }
 357
 358 /*******************************************************************
 359  Pull a DATA_BLOB from an xattr given a pathname.
 360  If the hash doesn't match, or doesn't exist - return the underlying
 361  filesystem sd.
 362 *******************************************************************/
 363
 364 static NTSTATUS get_nt_acl_internal(vfs_handle_struct *handle,
 365                                     files_struct *fsp,
 366                                     const char *name,
 367                                     uint32_t security_info,
 368                                     TALLOC_CTX *mem_ctx,
 369                                     struct security_descriptor **ppdesc)
 370 {
 371         DATA_BLOB blob = data_blob_null;
 372         NTSTATUS status;
 373         uint16_t hash_type = XATTR_SD_HASH_TYPE_NONE;
 374         uint16_t xattr_version = 0;
 375         uint8_t hash[XATTR_SD_HASH_SIZE];
 376         uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE];
 377         uint8_t hash_tmp[XATTR_SD_HASH_SIZE];
 378         uint8_t sys_acl_hash_tmp[XATTR_SD_HASH_SIZE];
 379         struct security_descriptor *psd = NULL;
 380         struct security_descriptor *pdesc_next = NULL;
 381         bool ignore_file_system_acl = lp_parm_bool(SNUM(handle->conn),
 382                                                 ACL_MODULE_NAME,
 383                                                 "ignore system acls",
 384                                                 false);
 385         TALLOC_CTX *frame = talloc_stackframe();
 386
 387         if (fsp && name == NULL) {
 388                 name = fsp->fsp_name->base_name;
 389         }
 390
 391         DEBUG(10, ("get_nt_acl_internal: name=%s\n", name));
 392
 393         status = get_acl_blob(frame, handle, fsp, name, &blob);
 394         if (!NT_STATUS_IS_OK(status)) {
 395                 DEBUG(10, ("get_nt_acl_internal: get_acl_blob returned %s\n",
 396                         nt_errstr(status)));
 397                 psd = NULL;
 398                 goto out;
 399         } else {
 400                 status = parse_acl_blob(&blob, mem_ctx, &psd,
 401                                         &hash_type, &xattr_version, &hash[0], &sys_acl_hash[0]);
 402                 if (!NT_STATUS_IS_OK(status)) {
 403                         DEBUG(10, ("parse_acl_blob returned %s\n",
 404                                    nt_errstr(status)));
 405                         psd = NULL;
 406                         goto out;
 407                 }
 408         }
 409
 410         /* Ensure we don't leak psd if we don't choose it.
 411          *
 412          * We don't allocate it onto frame as it is preferred not to
 413          * steal from a talloc pool.
 414          */
 415         talloc_steal(frame, psd);
 416
 417         /* determine which type of xattr we got */
 418         switch (xattr_version) {
 419         case 1:
 420         case 2:
 421                 /* These xattr types are unilatteral, they do not
 422                  * require confirmation of the hash.  In particular,
 423                  * the NTVFS file server uses version 1, but
 424                  * 'samba-tool ntacl' can set these as well */
 425                 goto out;
 426         case 3:
 427         case 4:
 428                 if (ignore_file_system_acl) {
 429                         goto out;
 430                 }
 431
 432                 break;
 433         default:
 434                 DEBUG(10, ("get_nt_acl_internal: ACL blob revision "
 435                            "mismatch (%u) for file %s\n",
 436                            (unsigned int)hash_type,
 437                            name));
 438                 TALLOC_FREE(psd);
 439                 psd = NULL;
 440                 goto out;
 441         }
 442
 443         /* determine which type of xattr we got */
 444         if (hash_type != XATTR_SD_HASH_TYPE_SHA256) {
 445                 DEBUG(10, ("get_nt_acl_internal: ACL blob hash type "
 446                            "(%u) unexpected for file %s\n",
 447                            (unsigned int)hash_type,
 448                            name));
 449                 TALLOC_FREE(psd);
 450                 psd = NULL;
 451                 goto out;
 452         }
 453
 454         /* determine which type of xattr we got */
 455         switch (xattr_version) {
 456         case 4:
 457         {
 458                 int ret;
 459                 char *sys_acl_blob_description;
 460                 DATA_BLOB sys_acl_blob;
 461                 if (fsp) {
 462                         /* Get the full underlying sd, then hash. */
 463                         ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FD(handle,
 464                                                                fsp,
 465                                                                frame,
 466                                                                &sys_acl_blob_description,
 467                                                                &sys_acl_blob);
 468                 } else {
 469                         /* Get the full underlying sd, then hash. */
 470                         ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FILE(handle,
 471                                                                  name,
 472                                                                  frame,
 473                                                                  &sys_acl_blob_description,
 474                                                                  &sys_acl_blob);
 475                 }
 476
 477                 /* If we fail to get the ACL blob (for some reason) then this
 478                  * is not fatal, we just work based on the NT ACL only */
 479                 if (ret == 0) {
 480                         status = hash_blob_sha256(sys_acl_blob, sys_acl_hash_tmp);
 481                         if (!NT_STATUS_IS_OK(status)) {
 482                                 TALLOC_FREE(frame);
 483                                 return status;
 484                         }
 485
 486                         if (memcmp(&sys_acl_hash[0], &sys_acl_hash_tmp[0],
 487                                    XATTR_SD_HASH_SIZE) == 0) {
 488                                 /* Hash matches, return blob sd. */
 489                                 DEBUG(10, ("get_nt_acl_internal: blob hash "
 490                                            "matches for file %s\n",
 491                                            name ));
 492                                 goto out;
 493                         }
 494                 }
 495
 496                 /* Otherwise, fall though and see if the NT ACL hash matches */
 497         }
 498         case 3:
 499                 /* Get the full underlying sd for the hash
 500                    or to return as backup. */
 501                 if (fsp) {
 502                         status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
 503                                                           fsp,
 504                                                           HASH_SECURITY_INFO,
 505                                                           mem_ctx,
 506                                                           &pdesc_next);
 507                 } else {
 508                         status = SMB_VFS_NEXT_GET_NT_ACL(handle,
 509                                                          name,
 510                                                          HASH_SECURITY_INFO,
 511                                                          mem_ctx,
 512                                                          &pdesc_next);
 513                 }
 514
 515                 if (!NT_STATUS_IS_OK(status)) {
 516                         DEBUG(10, ("get_nt_acl_internal: get_next_acl for file %s "
 517                                    "returned %s\n",
 518                                    name,
 519                                    nt_errstr(status)));
 520                         TALLOC_FREE(frame);
 521                         return status;
 522                 }
 523
 524                 /* Ensure we don't leak psd_next if we don't choose it.
 525                  *
 526                  * We don't allocate it onto frame as it is preferred not to
 527                  * steal from a talloc pool.
 528                  */
 529                 talloc_steal(frame, pdesc_next);
 530
 531                 status = hash_sd_sha256(pdesc_next, hash_tmp);
 532                 if (!NT_STATUS_IS_OK(status)) {
 533                         TALLOC_FREE(psd);
 534                         psd = pdesc_next;
 535                         goto out;
 536                 }
 537
 538                 if (memcmp(&hash[0], &hash_tmp[0], XATTR_SD_HASH_SIZE) == 0) {
 539                         /* Hash matches, return blob sd. */
 540                         DEBUG(10, ("get_nt_acl_internal: blob hash "
 541                                    "matches for file %s\n",
 542                                    name ));
 543                         goto out;
 544                 }
 545
 546                 /* Hash doesn't match, return underlying sd. */
 547                 DEBUG(10, ("get_nt_acl_internal: blob hash "
 548                            "does not match for file %s - returning "
 549                            "file system SD mapping.\n",
 550                            name ));
 551
 552                 if (DEBUGLEVEL >= 10) {
 553                         DEBUG(10,("get_nt_acl_internal: acl for blob hash for %s is:\n",
 554                                   name ));
 555                         NDR_PRINT_DEBUG(security_descriptor, pdesc_next);
 556                 }
 557
 558                 TALLOC_FREE(psd);
 559                 psd = pdesc_next;
 560         }
 561   out:
 562
 563         if (psd == NULL) {
 564                 /* Get the full underlying sd, as we failed to get the
 565                  * blob for the hash, or the revision/hash type wasn't
 566                  * known */
 567                 if (fsp) {
 568                         status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
 569                                                           fsp,
 570                                                           security_info,
 571                                                           mem_ctx,
 572                                                           &pdesc_next);
 573                 } else {
 574                         status = SMB_VFS_NEXT_GET_NT_ACL(handle,
 575                                                          name,
 576                                                          security_info,
 577                                                          mem_ctx,
 578                                                          &pdesc_next);
 579                 }
 580
 581                 if (!NT_STATUS_IS_OK(status)) {
 582                         DEBUG(10, ("get_nt_acl_internal: get_next_acl for file %s "
 583                                    "returned %s\n",
 584                                    name,
 585                                    nt_errstr(status)));
 586                         TALLOC_FREE(frame);
 587                         return status;
 588                 }
 589
 590                 /* Ensure we don't leak psd_next if we don't choose it.
 591                  *
 592                  * We don't allocate it onto frame as it is preferred not to
 593                  * steal from a talloc pool.
 594                  */
 595                 talloc_steal(frame, pdesc_next);
 596                 psd = pdesc_next;
 597         }
 598
 599         if (psd != pdesc_next) {
 600                 /* We're returning the blob, throw
 601                  * away the filesystem SD. */
 602                 TALLOC_FREE(pdesc_next);
 603         } else {
 604                 SMB_STRUCT_STAT sbuf;
 605                 SMB_STRUCT_STAT *psbuf = &sbuf;
 606                 bool is_directory = false;
 607                 /*
 608                  * We're returning the underlying ACL from the
 609                  * filesystem. If it's a directory, and has no
 610                  * inheritable ACE entries we have to fake them.
 611                  */
 612                 if (fsp) {
 613                         status = vfs_stat_fsp(fsp);
 614                         if (!NT_STATUS_IS_OK(status)) {
 615                                 TALLOC_FREE(frame);
 616                                 return status;
 617                         }
 618                         psbuf = &fsp->fsp_name->st;
 619                 } else {
 620                         int ret = vfs_stat_smb_fname(handle->conn,
 621                                                 name,
 622                                                 &sbuf);
 623                         if (ret == -1) {
 624                                 TALLOC_FREE(frame);
 625                                 return map_nt_error_from_unix(errno);
 626                         }
 627                 }
 628                 is_directory = S_ISDIR(psbuf->st_ex_mode);
 629
 630                 if (ignore_file_system_acl) {
 631                         TALLOC_FREE(pdesc_next);
 632                         status = make_default_filesystem_acl(mem_ctx,
 633                                                 name,
 634                                                 psbuf,
 635                                                 &psd);
 636                         if (!NT_STATUS_IS_OK(status)) {
 637                                 TALLOC_FREE(frame);
 638                                 return status;
 639                         }
 640                 } else {
 641                         if (is_directory &&
 642                                 !sd_has_inheritable_components(psd,
 643                                                         true)) {
 644                                 status = add_directory_inheritable_components(
 645                                                         handle,
 646                                                         name,
 647                                                         psbuf,
 648                                                         psd);
 649                                 if (!NT_STATUS_IS_OK(status)) {
 650                                         TALLOC_FREE(frame);
 651                                         return status;
 652                                 }
 653                         }
 654                         /* The underlying POSIX module always sets
 655                            the ~SEC_DESC_DACL_PROTECTED bit, as ACLs
 656                            can't be inherited in this way under POSIX.
 657                            Remove it for Windows-style ACLs. */
 658                         psd->type &= ~SEC_DESC_DACL_PROTECTED;
 659                 }
 660         }
 661
 662         if (!(security_info & SECINFO_OWNER)) {
 663                 psd->owner_sid = NULL;
 664         }
 665         if (!(security_info & SECINFO_GROUP)) {
 666                 psd->group_sid = NULL;
 667         }
 668         if (!(security_info & SECINFO_DACL)) {
 669                 psd->type &= ~SEC_DESC_DACL_PRESENT;
 670                 psd->dacl = NULL;
 671         }
 672         if (!(security_info & SECINFO_SACL)) {
 673                 psd->type &= ~SEC_DESC_SACL_PRESENT;
 674                 psd->sacl = NULL;
 675         }
 676
 677         TALLOC_FREE(blob.data);
 678
 679         if (DEBUGLEVEL >= 10) {
 680                 DEBUG(10,("get_nt_acl_internal: returning acl for %s is:\n",
 681                         name ));
 682                 NDR_PRINT_DEBUG(security_descriptor, psd);
 683         }
 684
 685         /* The VFS API is that the ACL is expected to be on mem_ctx */
 686         *ppdesc = talloc_move(mem_ctx, &psd);
 687
 688         TALLOC_FREE(frame);
 689         return NT_STATUS_OK;
 690 }
 691
 692 /*********************************************************************
 693  Fetch a security descriptor given an fsp.
 694 *********************************************************************/
 695
 696 static NTSTATUS fget_nt_acl_common(vfs_handle_struct *handle,
 697                                    files_struct *fsp,
 698                                    uint32_t security_info,
 699                                    TALLOC_CTX *mem_ctx,
 700                                    struct security_descriptor **ppdesc)
 701 {
 702         return get_nt_acl_internal(handle, fsp,
 703                                    NULL, security_info, mem_ctx, ppdesc);
 704 }
 705
 706 /*********************************************************************
 707  Fetch a security descriptor given a pathname.
 708 *********************************************************************/
 709
 710 static NTSTATUS get_nt_acl_common(vfs_handle_struct *handle,
 711                                   const char *name,
 712                                   uint32_t security_info,
 713                                   TALLOC_CTX *mem_ctx,
 714                                   struct security_descriptor **ppdesc)
 715 {
 716         return get_nt_acl_internal(handle, NULL,
 717                                    name, security_info, mem_ctx, ppdesc);
 718 }
 719
 720 /*********************************************************************
 721  Store a security descriptor given an fsp.
 722 *********************************************************************/
 723
 724 static NTSTATUS fset_nt_acl_common(vfs_handle_struct *handle, files_struct *fsp,
 725         uint32_t security_info_sent, const struct security_descriptor *orig_psd)
 726 {
 727         NTSTATUS status;
 728         int ret;
 729         DATA_BLOB blob, sys_acl_blob;
 730         struct security_descriptor *pdesc_next = NULL;
 731         struct security_descriptor *psd = NULL;
 732         uint8_t hash[XATTR_SD_HASH_SIZE];
 733         uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE];
 734         bool chown_needed = false;
 735         char *sys_acl_description;
 736         TALLOC_CTX *frame = talloc_stackframe();
 737
 738         if (DEBUGLEVEL >= 10) {
 739                 DEBUG(10,("fset_nt_acl_xattr: incoming sd for file %s\n",
 740                           fsp_str_dbg(fsp)));
 741                 NDR_PRINT_DEBUG(security_descriptor,
 742                         discard_const_p(struct security_descriptor, orig_psd));
 743         }
 744
 745         status = get_nt_acl_internal(handle, fsp,
 746                         NULL,
 747                         SECINFO_OWNER|SECINFO_GROUP|SECINFO_DACL|SECINFO_SACL,
 748                                      frame,
 749                         &psd);
 750
 751         if (!NT_STATUS_IS_OK(status)) {
 752                 TALLOC_FREE(frame);
 753                 return status;
 754         }
 755
 756         psd->revision = orig_psd->revision;
 757         /* All our SD's are self relative. */
 758         psd->type = orig_psd->type | SEC_DESC_SELF_RELATIVE;
 759
 760         if ((security_info_sent & SECINFO_OWNER) && (orig_psd->owner_sid != NULL)) {
 761                 if (!dom_sid_equal(orig_psd->owner_sid, psd->owner_sid)) {
 762                         /* We're changing the owner. */
 763                         chown_needed = true;
 764                 }
 765                 psd->owner_sid = orig_psd->owner_sid;
 766         }
 767         if ((security_info_sent & SECINFO_GROUP) && (orig_psd->group_sid != NULL)) {
 768                 if (!dom_sid_equal(orig_psd->group_sid, psd->group_sid)) {
 769                         /* We're changing the group. */
 770                         chown_needed = true;
 771                 }
 772                 psd->group_sid = orig_psd->group_sid;
 773         }
 774         if (security_info_sent & SECINFO_DACL) {
 775                 psd->dacl = orig_psd->dacl;
 776                 psd->type |= SEC_DESC_DACL_PRESENT;
 777         }
 778         if (security_info_sent & SECINFO_SACL) {
 779                 psd->sacl = orig_psd->sacl;
 780                 psd->type |= SEC_DESC_SACL_PRESENT;
 781         }
 782
 783         status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp, security_info_sent, psd);
 784         if (!NT_STATUS_IS_OK(status)) {
 785                 if (!NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) {
 786                         TALLOC_FREE(frame);
 787                         return status;
 788                 }
 789                 /* We got access denied here. If we're already root,
 790                    or we didn't need to do a chown, or the fsp isn't
 791                    open with WRITE_OWNER access, just return. */
 792                 if (get_current_uid(handle->conn) == 0 ||
 793                                 chown_needed == false ||
 794                                 !(fsp->access_mask & SEC_STD_WRITE_OWNER)) {
 795                         TALLOC_FREE(frame);
 796                         return NT_STATUS_ACCESS_DENIED;
 797                 }
 798
 799                 DEBUG(10,("fset_nt_acl_common: overriding chown on file %s "
 800                         "for sid %s\n",
 801                         fsp_str_dbg(fsp),
 802                         sid_string_tos(psd->owner_sid)
 803                         ));
 804
 805                 /* Ok, we failed to chown and we have
 806                    SEC_STD_WRITE_OWNER access - override. */
 807                 become_root();
 808                 status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp,
 809                                 security_info_sent, psd);
 810                 unbecome_root();
 811                 if (!NT_STATUS_IS_OK(status)) {
 812                         TALLOC_FREE(frame);
 813                         return status;
 814                 }
 815         }
 816
 817         /* Get the full underlying sd, then hash. */
 818         status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
 819                                           fsp,
 820                                           HASH_SECURITY_INFO,
 821                                           frame,
 822                                           &pdesc_next);
 823
 824         if (!NT_STATUS_IS_OK(status)) {
 825                 TALLOC_FREE(frame);
 826                 return status;
 827         }
 828
 829         status = hash_sd_sha256(pdesc_next, hash);
 830         if (!NT_STATUS_IS_OK(status)) {
 831                 TALLOC_FREE(frame);
 832                 return status;
 833         }
 834
 835         /* Get the full underlying sd, then hash. */
 836         ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FD(handle,
 837                                                fsp,
 838                                                frame,
 839                                                &sys_acl_description,
 840                                                &sys_acl_blob);
 841
 842         /* If we fail to get the ACL blob (for some reason) then this
 843          * is not fatal, we just work based on the NT ACL only */
 844         if (ret != 0) {
 845                 if (DEBUGLEVEL >= 10) {
 846                         DEBUG(10,("fset_nt_acl_xattr: storing xattr sd for file %s\n",
 847                                   fsp_str_dbg(fsp)));
 848                         NDR_PRINT_DEBUG(security_descriptor,
 849                                         discard_const_p(struct security_descriptor, psd));
 850
 851                         DEBUG(10,("fset_nt_acl_xattr: storing has in xattr sd based on \n"));
 852                         NDR_PRINT_DEBUG(security_descriptor,
 853                                         discard_const_p(struct security_descriptor, pdesc_next));
 854                 }
 855                 status = create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash);
 856                 if (!NT_STATUS_IS_OK(status)) {
 857                         DEBUG(10, ("fset_nt_acl_xattr: create_acl_blob failed\n"));
 858                         TALLOC_FREE(frame);
 859                         return status;
 860                 }
 861
 862                 status = store_acl_blob_fsp(handle, fsp, &blob);
 863
 864                 TALLOC_FREE(frame);
 865                 return status;
 866         }
 867
 868         status = hash_blob_sha256(sys_acl_blob, sys_acl_hash);
 869         if (!NT_STATUS_IS_OK(status)) {
 870                 TALLOC_FREE(frame);
 871                 return status;
 872         }
 873
 874         if (DEBUGLEVEL >= 10) {
 875                 DEBUG(10,("fset_nt_acl_xattr: storing xattr sd for file %s based on system ACL\n",
 876                           fsp_str_dbg(fsp)));
 877                 NDR_PRINT_DEBUG(security_descriptor,
 878                                 discard_const_p(struct security_descriptor, psd));
 879
 880                 DEBUG(10,("fset_nt_acl_xattr: storing hash in xattr sd based on system ACL and:\n"));
 881                 NDR_PRINT_DEBUG(security_descriptor,
 882                                 discard_const_p(struct security_descriptor, pdesc_next));
 883         }
 884
 885         /* We store hashes of both the sys ACL blob and the NT
 886          * security desciptor mapped from that ACL so as to improve
 887          * our chances against some inadvertant change breaking the
 888          * hash used */
 889         status = create_sys_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash,
 890                                      sys_acl_description, sys_acl_hash);
 891         if (!NT_STATUS_IS_OK(status)) {
 892                 DEBUG(10, ("fset_nt_acl_xattr: create_sys_acl_blob failed\n"));
 893                 TALLOC_FREE(frame);
 894                 return status;
 895         }
 896
 897         status = store_acl_blob_fsp(handle, fsp, &blob);
 898
 899         TALLOC_FREE(frame);
 900         return status;
 901 }
 902
 903 static int acl_common_remove_object(vfs_handle_struct *handle,
 904                                         const char *path,
 905                                         bool is_directory)
 906 {
 907         connection_struct *conn = handle->conn;
 908         struct file_id id;
 909         files_struct *fsp = NULL;
 910         int ret = 0;
 911         char *parent_dir = NULL;
 912         const char *final_component = NULL;
 913         struct smb_filename local_fname;
 914         int saved_errno = 0;
 915         char *saved_dir = NULL;
 916
 917         saved_dir = vfs_GetWd(talloc_tos(),conn);
 918         if (!saved_dir) {
 919                 saved_errno = errno;
 920                 goto out;
 921         }
 922
 923         if (!parent_dirname(talloc_tos(), path,
 924                         &parent_dir, &final_component)) {
 925                 saved_errno = ENOMEM;
 926                 goto out;
 927         }
 928
 929         DEBUG(10,("acl_common_remove_object: removing %s %s/%s\n",
 930                 is_directory ? "directory" : "file",
 931                 parent_dir, final_component ));
 932
 933         /* cd into the parent dir to pin it. */
 934         ret = vfs_ChDir(conn, parent_dir);
 935         if (ret == -1) {
 936                 saved_errno = errno;
 937                 goto out;
 938         }
 939
 940         ZERO_STRUCT(local_fname);
 941         local_fname.base_name = discard_const_p(char, final_component);
 942
 943         /* Must use lstat here. */
 944         ret = SMB_VFS_LSTAT(conn, &local_fname);
 945         if (ret == -1) {
 946                 saved_errno = errno;
 947                 goto out;
 948         }
 949
 950         /* Ensure we have this file open with DELETE access. */
 951         id = vfs_file_id_from_sbuf(conn, &local_fname.st);
 952         for (fsp = file_find_di_first(conn->sconn, id); fsp;
 953                      fsp = file_find_di_next(fsp)) {
 954                 if (fsp->access_mask & DELETE_ACCESS &&
 955                                 fsp->delete_on_close) {
 956                         /* We did open this for delete,
 957                          * allow the delete as root.
 958                          */
 959                         break;
 960                 }
 961         }
 962
 963         if (!fsp) {
 964                 DEBUG(10,("acl_common_remove_object: %s %s/%s "
 965                         "not an open file\n",
 966                         is_directory ? "directory" : "file",
 967                         parent_dir, final_component ));
 968                 saved_errno = EACCES;
 969                 goto out;
 970         }
 971
 972         become_root();
 973         if (is_directory) {
 974                 ret = SMB_VFS_NEXT_RMDIR(handle, final_component);
 975         } else {
 976                 ret = SMB_VFS_NEXT_UNLINK(handle, &local_fname);
 977         }
 978         unbecome_root();
 979
 980         if (ret == -1) {
 981                 saved_errno = errno;
 982         }
 983
 984   out:
 985
 986         TALLOC_FREE(parent_dir);
 987
 988         if (saved_dir) {
 989                 vfs_ChDir(conn, saved_dir);
 990         }
 991         if (saved_errno) {
 992                 errno = saved_errno;
 993         }
 994         return ret;
 995 }
 996
 997 static int rmdir_acl_common(struct vfs_handle_struct *handle,
 998                                 const char *path)
 999 {
1000         int ret;
1001
1002         /* Try the normal rmdir first. */
1003         ret = SMB_VFS_NEXT_RMDIR(handle, path);
1004         if (ret == 0) {
1005                 return 0;
1006         }
1007         if (errno == EACCES || errno == EPERM) {
1008                 /* Failed due to access denied,
1009                    see if we need to root override. */
1010                 return acl_common_remove_object(handle,
1011                                                 path,
1012                                                 true);
1013         }
1014
1015         DEBUG(10,("rmdir_acl_common: unlink of %s failed %s\n",
1016                 path,
1017                 strerror(errno) ));
1018         return -1;
1019 }
1020
1021 static int unlink_acl_common(struct vfs_handle_struct *handle,
1022                         const struct smb_filename *smb_fname)
1023 {
1024         int ret;
1025
1026         /* Try the normal unlink first. */
1027         ret = SMB_VFS_NEXT_UNLINK(handle, smb_fname);
1028         if (ret == 0) {
1029                 return 0;
1030         }
1031         if (errno == EACCES || errno == EPERM) {
1032                 /* Failed due to access denied,
1033                    see if we need to root override. */
1034
1035                 /* Don't do anything fancy for streams. */
1036                 if (smb_fname->stream_name) {
1037                         return -1;
1038                 }
1039                 return acl_common_remove_object(handle,
1040                                         smb_fname->base_name,
1041                                         false);
1042         }
1043
1044         DEBUG(10,("unlink_acl_common: unlink of %s failed %s\n",
1045                 smb_fname->base_name,
1046                 strerror(errno) ));
1047         return -1;
1048 }
1049
1050 static int chmod_acl_module_common(struct vfs_handle_struct *handle,
1051                         const char *path, mode_t mode)
1052 {
1053         if (lp_posix_pathnames()) {
1054                 /* Only allow this on POSIX pathnames. */
1055                 return SMB_VFS_NEXT_CHMOD(handle, path, mode);
1056         }
1057         return 0;
1058 }
1059
1060 static int fchmod_acl_module_common(struct vfs_handle_struct *handle,
1061                         struct files_struct *fsp, mode_t mode)
1062 {
1063         if (fsp->posix_open) {
1064                 /* Only allow this on POSIX opens. */
1065                 return SMB_VFS_NEXT_FCHMOD(handle, fsp, mode);
1066         }
1067         return 0;
1068 }
1069
1070 static int chmod_acl_acl_module_common(struct vfs_handle_struct *handle,
1071                         const char *name, mode_t mode)
1072 {
1073         if (lp_posix_pathnames()) {
1074                 /* Only allow this on POSIX pathnames. */
1075                 return SMB_VFS_NEXT_CHMOD_ACL(handle, name, mode);
1076         }
1077         return 0;
1078 }
1079
1080 static int fchmod_acl_acl_module_common(struct vfs_handle_struct *handle,
1081                         struct files_struct *fsp, mode_t mode)
1082 {
1083         if (fsp->posix_open) {
1084                 /* Only allow this on POSIX opens. */
1085                 return SMB_VFS_NEXT_FCHMOD_ACL(handle, fsp, mode);
1086         }
1087         return 0;
1088 }