source3/modules/vfs_acl_common.c

   1 /*
   2  * Store Windows ACLs in data store - common functions.
   3  * #included into modules/vfs_acl_xattr.c and modules/vfs_acl_tdb.c
   4  *
   5  * Copyright (C) Volker Lendecke, 2008
   6  * Copyright (C) Jeremy Allison, 2009
   7  * Copyright (C) Ralph Böhme, 2016
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 3 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  21  */
  22
  23 #include "includes.h"
  24 #include "vfs_acl_common.h"
  25 #include "smbd/smbd.h"
  26 #include "system/filesys.h"
  27 #include "librpc/gen_ndr/ndr_xattr.h"
  28 #include "../libcli/security/security.h"
  29 #include "../librpc/gen_ndr/ndr_security.h"
  30 #include "../lib/util/bitmap.h"
  31 #include "lib/crypto/sha256.h"
  32 #include "passdb/lookup_sid.h"
  33
  34 static NTSTATUS create_acl_blob(const struct security_descriptor *psd,
  35                         DATA_BLOB *pblob,
  36                         uint16_t hash_type,
  37                         uint8_t hash[XATTR_SD_HASH_SIZE]);
  38
  39 #define HASH_SECURITY_INFO (SECINFO_OWNER | \
  40                                 SECINFO_GROUP | \
  41                                 SECINFO_DACL | \
  42                                 SECINFO_SACL)
  43
  44 static const struct enum_list default_acl_style[] = {
  45         {DEFAULT_ACL_POSIX,     "posix"},
  46         {DEFAULT_ACL_WINDOWS,   "windows"}
  47 };
  48
  49 bool init_acl_common_config(vfs_handle_struct *handle,
  50                             const char *module_name)
  51 {
  52         struct acl_common_config *config = NULL;
  53
  54         config = talloc_zero(handle->conn, struct acl_common_config);
  55         if (config == NULL) {
  56                 DBG_ERR("talloc_zero() failed\n");
  57                 errno = ENOMEM;
  58                 return false;
  59         }
  60
  61         config->ignore_system_acls = lp_parm_bool(SNUM(handle->conn),
  62                                                   module_name,
  63                                                   "ignore system acls",
  64                                                   false);
  65         config->default_acl_style = lp_parm_enum(SNUM(handle->conn),
  66                                                  module_name,
  67                                                  "default acl style",
  68                                                  default_acl_style,
  69                                                  DEFAULT_ACL_POSIX);
  70
  71         SMB_VFS_HANDLE_SET_DATA(handle, config, NULL,
  72                                 struct acl_common_config,
  73                                 return false);
  74
  75         return true;
  76 }
  77
  78
  79 /*******************************************************************
  80  Hash a security descriptor.
  81 *******************************************************************/
  82
  83 static NTSTATUS hash_blob_sha256(DATA_BLOB blob,
  84                                  uint8_t *hash)
  85 {
  86         SHA256_CTX tctx;
  87
  88         memset(hash, '\0', XATTR_SD_HASH_SIZE);
  89
  90         samba_SHA256_Init(&tctx);
  91         samba_SHA256_Update(&tctx, blob.data, blob.length);
  92         samba_SHA256_Final(hash, &tctx);
  93
  94         return NT_STATUS_OK;
  95 }
  96
  97 /*******************************************************************
  98  Hash a security descriptor.
  99 *******************************************************************/
 100
 101 static NTSTATUS hash_sd_sha256(struct security_descriptor *psd,
 102                         uint8_t *hash)
 103 {
 104         DATA_BLOB blob;
 105         NTSTATUS status;
 106
 107         memset(hash, '\0', XATTR_SD_HASH_SIZE);
 108         status = create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash);
 109         if (!NT_STATUS_IS_OK(status)) {
 110                 return status;
 111         }
 112         return hash_blob_sha256(blob, hash);
 113 }
 114
 115 /*******************************************************************
 116  Parse out a struct security_descriptor from a DATA_BLOB.
 117 *******************************************************************/
 118
 119 static NTSTATUS parse_acl_blob(const DATA_BLOB *pblob,
 120                                TALLOC_CTX *mem_ctx,
 121                                struct security_descriptor **ppdesc,
 122                                uint16_t *p_hash_type,
 123                                uint16_t *p_version,
 124                                uint8_t hash[XATTR_SD_HASH_SIZE],
 125                                uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE])
 126 {
 127         struct xattr_NTACL xacl;
 128         enum ndr_err_code ndr_err;
 129         size_t sd_size;
 130         TALLOC_CTX *frame = talloc_stackframe();
 131
 132         ndr_err = ndr_pull_struct_blob(pblob, frame, &xacl,
 133                         (ndr_pull_flags_fn_t)ndr_pull_xattr_NTACL);
 134
 135         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 136                 DBG_INFO("ndr_pull_xattr_NTACL failed: %s\n",
 137                          ndr_errstr(ndr_err));
 138                 TALLOC_FREE(frame);
 139                 return ndr_map_error2ntstatus(ndr_err);
 140         }
 141
 142         *p_version = xacl.version;
 143
 144         switch (xacl.version) {
 145                 case 1:
 146                         *ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
 147                                         xacl.info.sd->type | SEC_DESC_SELF_RELATIVE,
 148                                         xacl.info.sd->owner_sid,
 149                                         xacl.info.sd->group_sid,
 150                                         xacl.info.sd->sacl,
 151                                         xacl.info.sd->dacl,
 152                                         &sd_size);
 153                         /* No hash - null out. */
 154                         *p_hash_type = XATTR_SD_HASH_TYPE_NONE;
 155                         memset(hash, '\0', XATTR_SD_HASH_SIZE);
 156                         break;
 157                 case 2:
 158                         *ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
 159                                         xacl.info.sd_hs2->sd->type | SEC_DESC_SELF_RELATIVE,
 160                                         xacl.info.sd_hs2->sd->owner_sid,
 161                                         xacl.info.sd_hs2->sd->group_sid,
 162                                         xacl.info.sd_hs2->sd->sacl,
 163                                         xacl.info.sd_hs2->sd->dacl,
 164                                         &sd_size);
 165                         /* No hash - null out. */
 166                         *p_hash_type = XATTR_SD_HASH_TYPE_NONE;
 167                         memset(hash, '\0', XATTR_SD_HASH_SIZE);
 168                         break;
 169                 case 3:
 170                         *ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
 171                                         xacl.info.sd_hs3->sd->type | SEC_DESC_SELF_RELATIVE,
 172                                         xacl.info.sd_hs3->sd->owner_sid,
 173                                         xacl.info.sd_hs3->sd->group_sid,
 174                                         xacl.info.sd_hs3->sd->sacl,
 175                                         xacl.info.sd_hs3->sd->dacl,
 176                                         &sd_size);
 177                         *p_hash_type = xacl.info.sd_hs3->hash_type;
 178                         /* Current version 3 (if no sys acl hash available). */
 179                         memcpy(hash, xacl.info.sd_hs3->hash, XATTR_SD_HASH_SIZE);
 180                         break;
 181                 case 4:
 182                         *ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
 183                                         xacl.info.sd_hs4->sd->type | SEC_DESC_SELF_RELATIVE,
 184                                         xacl.info.sd_hs4->sd->owner_sid,
 185                                         xacl.info.sd_hs4->sd->group_sid,
 186                                         xacl.info.sd_hs4->sd->sacl,
 187                                         xacl.info.sd_hs4->sd->dacl,
 188                                         &sd_size);
 189                         *p_hash_type = xacl.info.sd_hs4->hash_type;
 190                         /* Current version 4. */
 191                         memcpy(hash, xacl.info.sd_hs4->hash, XATTR_SD_HASH_SIZE);
 192                         memcpy(sys_acl_hash, xacl.info.sd_hs4->sys_acl_hash, XATTR_SD_HASH_SIZE);
 193                         break;
 194                 default:
 195                         TALLOC_FREE(frame);
 196                         return NT_STATUS_REVISION_MISMATCH;
 197         }
 198
 199         TALLOC_FREE(frame);
 200
 201         return (*ppdesc != NULL) ? NT_STATUS_OK : NT_STATUS_NO_MEMORY;
 202 }
 203
 204 /*******************************************************************
 205  Create a DATA_BLOB from a hash of the security descriptor storead at
 206  the system layer and the NT ACL we wish to preserve
 207 *******************************************************************/
 208
 209 static NTSTATUS create_acl_blob(const struct security_descriptor *psd,
 210                         DATA_BLOB *pblob,
 211                         uint16_t hash_type,
 212                         uint8_t hash[XATTR_SD_HASH_SIZE])
 213 {
 214         struct xattr_NTACL xacl;
 215         struct security_descriptor_hash_v3 sd_hs3;
 216         enum ndr_err_code ndr_err;
 217         TALLOC_CTX *ctx = talloc_tos();
 218
 219         ZERO_STRUCT(xacl);
 220         ZERO_STRUCT(sd_hs3);
 221
 222         xacl.version = 3;
 223         xacl.info.sd_hs3 = &sd_hs3;
 224         xacl.info.sd_hs3->sd = discard_const_p(struct security_descriptor, psd);
 225         xacl.info.sd_hs3->hash_type = hash_type;
 226         memcpy(&xacl.info.sd_hs3->hash[0], hash, XATTR_SD_HASH_SIZE);
 227
 228         ndr_err = ndr_push_struct_blob(
 229                         pblob, ctx, &xacl,
 230                         (ndr_push_flags_fn_t)ndr_push_xattr_NTACL);
 231
 232         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 233                 DBG_INFO("ndr_push_xattr_NTACL failed: %s\n",
 234                          ndr_errstr(ndr_err));
 235                 return ndr_map_error2ntstatus(ndr_err);
 236         }
 237
 238         return NT_STATUS_OK;
 239 }
 240
 241 /*******************************************************************
 242  Create a DATA_BLOB from a hash of the security descriptors
 243  (system and NT) stored at the system layer and the NT ACL we wish
 244  to preserve.
 245 *******************************************************************/
 246
 247 static NTSTATUS create_sys_acl_blob(const struct security_descriptor *psd,
 248                                     DATA_BLOB *pblob,
 249                                     uint16_t hash_type,
 250                                     uint8_t hash[XATTR_SD_HASH_SIZE],
 251                                     const char *description,
 252                                     uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE])
 253 {
 254         struct xattr_NTACL xacl;
 255         struct security_descriptor_hash_v4 sd_hs4;
 256         enum ndr_err_code ndr_err;
 257         TALLOC_CTX *ctx = talloc_tos();
 258         NTTIME nttime_now;
 259         struct timeval now = timeval_current();
 260         nttime_now = timeval_to_nttime(&now);
 261
 262         ZERO_STRUCT(xacl);
 263         ZERO_STRUCT(sd_hs4);
 264
 265         xacl.version = 4;
 266         xacl.info.sd_hs4 = &sd_hs4;
 267         xacl.info.sd_hs4->sd = discard_const_p(struct security_descriptor, psd);
 268         xacl.info.sd_hs4->hash_type = hash_type;
 269         memcpy(&xacl.info.sd_hs4->hash[0], hash, XATTR_SD_HASH_SIZE);
 270         xacl.info.sd_hs4->description = description;
 271         xacl.info.sd_hs4->time = nttime_now;
 272         memcpy(&xacl.info.sd_hs4->sys_acl_hash[0], sys_acl_hash, XATTR_SD_HASH_SIZE);
 273
 274         ndr_err = ndr_push_struct_blob(
 275                         pblob, ctx, &xacl,
 276                         (ndr_push_flags_fn_t)ndr_push_xattr_NTACL);
 277
 278         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 279                 DBG_INFO("ndr_push_xattr_NTACL failed: %s\n",
 280                          ndr_errstr(ndr_err));
 281                 return ndr_map_error2ntstatus(ndr_err);
 282         }
 283
 284         return NT_STATUS_OK;
 285 }
 286
 287 /*******************************************************************
 288  Add in 3 inheritable components for a non-inheritable directory ACL.
 289  CREATOR_OWNER/CREATOR_GROUP/WORLD.
 290 *******************************************************************/
 291
 292 static NTSTATUS add_directory_inheritable_components(vfs_handle_struct *handle,
 293                                 const char *name,
 294                                 SMB_STRUCT_STAT *psbuf,
 295                                 struct security_descriptor *psd)
 296 {
 297         struct connection_struct *conn = handle->conn;
 298         int num_aces = (psd->dacl ? psd->dacl->num_aces : 0);
 299         struct smb_filename smb_fname;
 300         enum security_ace_type acltype;
 301         uint32_t access_mask;
 302         mode_t dir_mode;
 303         mode_t file_mode;
 304         mode_t mode;
 305         struct security_ace *new_ace_list;
 306
 307         if (psd->dacl) {
 308                 new_ace_list = talloc_zero_array(psd->dacl,
 309                                                  struct security_ace,
 310                                                  num_aces + 3);
 311         } else {
 312                 /*
 313                  * make_sec_acl() at the bottom of this function
 314                  * dupliates new_ace_list
 315                  */
 316                 new_ace_list = talloc_zero_array(talloc_tos(),
 317                                                  struct security_ace,
 318                                                  num_aces + 3);
 319         }
 320
 321         if (new_ace_list == NULL) {
 322                 return NT_STATUS_NO_MEMORY;
 323         }
 324
 325         /* Fake a quick smb_filename. */
 326         ZERO_STRUCT(smb_fname);
 327         smb_fname.st = *psbuf;
 328         smb_fname.base_name = discard_const_p(char, name);
 329
 330         dir_mode = unix_mode(conn,
 331                         FILE_ATTRIBUTE_DIRECTORY, &smb_fname, NULL);
 332         file_mode = unix_mode(conn,
 333                         FILE_ATTRIBUTE_ARCHIVE, &smb_fname, NULL);
 334
 335         mode = dir_mode | file_mode;
 336
 337         DBG_DEBUG("directory %s, mode = 0%o\n", name, (unsigned int)mode);
 338
 339         if (num_aces) {
 340                 memcpy(new_ace_list, psd->dacl->aces,
 341                         num_aces * sizeof(struct security_ace));
 342         }
 343         access_mask = map_canon_ace_perms(SNUM(conn), &acltype,
 344                                 mode & 0700, false);
 345
 346         init_sec_ace(&new_ace_list[num_aces],
 347                         &global_sid_Creator_Owner,
 348                         acltype,
 349                         access_mask,
 350                         SEC_ACE_FLAG_CONTAINER_INHERIT|
 351                                 SEC_ACE_FLAG_OBJECT_INHERIT|
 352                                 SEC_ACE_FLAG_INHERIT_ONLY);
 353         access_mask = map_canon_ace_perms(SNUM(conn), &acltype,
 354                                 (mode << 3) & 0700, false);
 355         init_sec_ace(&new_ace_list[num_aces+1],
 356                         &global_sid_Creator_Group,
 357                         acltype,
 358                         access_mask,
 359                         SEC_ACE_FLAG_CONTAINER_INHERIT|
 360                                 SEC_ACE_FLAG_OBJECT_INHERIT|
 361                                 SEC_ACE_FLAG_INHERIT_ONLY);
 362         access_mask = map_canon_ace_perms(SNUM(conn), &acltype,
 363                                 (mode << 6) & 0700, false);
 364         init_sec_ace(&new_ace_list[num_aces+2],
 365                         &global_sid_World,
 366                         acltype,
 367                         access_mask,
 368                         SEC_ACE_FLAG_CONTAINER_INHERIT|
 369                                 SEC_ACE_FLAG_OBJECT_INHERIT|
 370                                 SEC_ACE_FLAG_INHERIT_ONLY);
 371         if (psd->dacl) {
 372                 psd->dacl->aces = new_ace_list;
 373                 psd->dacl->num_aces += 3;
 374                 psd->dacl->size += new_ace_list[num_aces].size +
 375                         new_ace_list[num_aces+1].size +
 376                         new_ace_list[num_aces+2].size;
 377         } else {
 378                 psd->dacl = make_sec_acl(psd,
 379                                 NT4_ACL_REVISION,
 380                                 3,
 381                                 new_ace_list);
 382                 if (psd->dacl == NULL) {
 383                         return NT_STATUS_NO_MEMORY;
 384                 }
 385         }
 386         return NT_STATUS_OK;
 387 }
 388
 389 static NTSTATUS make_default_acl_posix(TALLOC_CTX *ctx,
 390                                        const char *name,
 391                                        SMB_STRUCT_STAT *psbuf,
 392                                        struct security_descriptor **ppdesc)
 393 {
 394         struct dom_sid owner_sid, group_sid;
 395         size_t size = 0;
 396         struct security_ace aces[4];
 397         uint32_t access_mask = 0;
 398         mode_t mode = psbuf->st_ex_mode;
 399         struct security_acl *new_dacl = NULL;
 400         int idx = 0;
 401
 402         DBG_DEBUG("file %s mode = 0%o\n",name, (int)mode);
 403
 404         uid_to_sid(&owner_sid, psbuf->st_ex_uid);
 405         gid_to_sid(&group_sid, psbuf->st_ex_gid);
 406
 407         /*
 408          We provide up to 4 ACEs
 409                 - Owner
 410                 - Group
 411                 - Everyone
 412                 - NT System
 413         */
 414
 415         if (mode & S_IRUSR) {
 416                 if (mode & S_IWUSR) {
 417                         access_mask |= SEC_RIGHTS_FILE_ALL;
 418                 } else {
 419                         access_mask |= SEC_RIGHTS_FILE_READ | SEC_FILE_EXECUTE;
 420                 }
 421         }
 422         if (mode & S_IWUSR) {
 423                 access_mask |= SEC_RIGHTS_FILE_WRITE | SEC_STD_DELETE;
 424         }
 425
 426         init_sec_ace(&aces[idx],
 427                         &owner_sid,
 428                         SEC_ACE_TYPE_ACCESS_ALLOWED,
 429                         access_mask,
 430                         0);
 431         idx++;
 432
 433         access_mask = 0;
 434         if (mode & S_IRGRP) {
 435                 access_mask |= SEC_RIGHTS_FILE_READ | SEC_FILE_EXECUTE;
 436         }
 437         if (mode & S_IWGRP) {
 438                 /* note that delete is not granted - this matches posix behaviour */
 439                 access_mask |= SEC_RIGHTS_FILE_WRITE;
 440         }
 441         if (access_mask) {
 442                 init_sec_ace(&aces[idx],
 443                         &group_sid,
 444                         SEC_ACE_TYPE_ACCESS_ALLOWED,
 445                         access_mask,
 446                         0);
 447                 idx++;
 448         }
 449
 450         access_mask = 0;
 451         if (mode & S_IROTH) {
 452                 access_mask |= SEC_RIGHTS_FILE_READ | SEC_FILE_EXECUTE;
 453         }
 454         if (mode & S_IWOTH) {
 455                 access_mask |= SEC_RIGHTS_FILE_WRITE;
 456         }
 457         if (access_mask) {
 458                 init_sec_ace(&aces[idx],
 459                         &global_sid_World,
 460                         SEC_ACE_TYPE_ACCESS_ALLOWED,
 461                         access_mask,
 462                         0);
 463                 idx++;
 464         }
 465
 466         init_sec_ace(&aces[idx],
 467                         &global_sid_System,
 468                         SEC_ACE_TYPE_ACCESS_ALLOWED,
 469                         SEC_RIGHTS_FILE_ALL,
 470                         0);
 471         idx++;
 472
 473         new_dacl = make_sec_acl(ctx,
 474                         NT4_ACL_REVISION,
 475                         idx,
 476                         aces);
 477
 478         if (!new_dacl) {
 479                 return NT_STATUS_NO_MEMORY;
 480         }
 481
 482         *ppdesc = make_sec_desc(ctx,
 483                         SECURITY_DESCRIPTOR_REVISION_1,
 484                         SEC_DESC_SELF_RELATIVE|SEC_DESC_DACL_PRESENT,
 485                         &owner_sid,
 486                         &group_sid,
 487                         NULL,
 488                         new_dacl,
 489                         &size);
 490         if (!*ppdesc) {
 491                 return NT_STATUS_NO_MEMORY;
 492         }
 493         return NT_STATUS_OK;
 494 }
 495
 496 static NTSTATUS make_default_acl_windows(TALLOC_CTX *ctx,
 497                                          const char *name,
 498                                          SMB_STRUCT_STAT *psbuf,
 499                                          struct security_descriptor **ppdesc)
 500 {
 501         struct dom_sid owner_sid, group_sid;
 502         size_t size = 0;
 503         struct security_ace aces[4];
 504         uint32_t access_mask = 0;
 505         mode_t mode = psbuf->st_ex_mode;
 506         struct security_acl *new_dacl = NULL;
 507         int idx = 0;
 508
 509         DBG_DEBUG("file [%s] mode [0%o]\n", name, (int)mode);
 510
 511         uid_to_sid(&owner_sid, psbuf->st_ex_uid);
 512         gid_to_sid(&group_sid, psbuf->st_ex_gid);
 513
 514         /*
 515          * We provide 2 ACEs:
 516          * - Owner
 517          * - NT System
 518          */
 519
 520         if (mode & S_IRUSR) {
 521                 if (mode & S_IWUSR) {
 522                         access_mask |= SEC_RIGHTS_FILE_ALL;
 523                 } else {
 524                         access_mask |= SEC_RIGHTS_FILE_READ | SEC_FILE_EXECUTE;
 525                 }
 526         }
 527         if (mode & S_IWUSR) {
 528                 access_mask |= SEC_RIGHTS_FILE_WRITE | SEC_STD_DELETE;
 529         }
 530
 531         init_sec_ace(&aces[idx],
 532                      &owner_sid,
 533                      SEC_ACE_TYPE_ACCESS_ALLOWED,
 534                      access_mask,
 535                      0);
 536         idx++;
 537
 538         init_sec_ace(&aces[idx],
 539                      &global_sid_System,
 540                      SEC_ACE_TYPE_ACCESS_ALLOWED,
 541                      SEC_RIGHTS_FILE_ALL,
 542                      0);
 543         idx++;
 544
 545         new_dacl = make_sec_acl(ctx,
 546                                 NT4_ACL_REVISION,
 547                                 idx,
 548                                 aces);
 549
 550         if (!new_dacl) {
 551                 return NT_STATUS_NO_MEMORY;
 552         }
 553
 554         *ppdesc = make_sec_desc(ctx,
 555                                 SECURITY_DESCRIPTOR_REVISION_1,
 556                                 SEC_DESC_SELF_RELATIVE|SEC_DESC_DACL_PRESENT,
 557                                 &owner_sid,
 558                                 &group_sid,
 559                                 NULL,
 560                                 new_dacl,
 561                                 &size);
 562         if (!*ppdesc) {
 563                 return NT_STATUS_NO_MEMORY;
 564         }
 565         return NT_STATUS_OK;
 566 }
 567
 568 static NTSTATUS make_default_filesystem_acl(
 569         TALLOC_CTX *ctx,
 570         enum default_acl_style acl_style,
 571         const char *name,
 572         SMB_STRUCT_STAT *psbuf,
 573         struct security_descriptor **ppdesc)
 574 {
 575         NTSTATUS status;
 576
 577         switch (acl_style) {
 578         case DEFAULT_ACL_POSIX:
 579                 status =  make_default_acl_posix(ctx, name, psbuf, ppdesc);
 580                 break;
 581
 582         case DEFAULT_ACL_WINDOWS:
 583                 status =  make_default_acl_windows(ctx, name, psbuf, ppdesc);
 584                 break;
 585
 586         default:
 587                 DBG_ERR("unknown acl style %d", acl_style);
 588                 status = NT_STATUS_INTERNAL_ERROR;
 589                 break;
 590         }
 591
 592         return status;
 593 }
 594
 595 /**
 596  * Validate an ACL blob
 597  *
 598  * This validates an ACL blob against the underlying filesystem ACL. If this
 599  * function returns NT_STATUS_OK ppsd can be
 600  *
 601  * 1. the ACL from the blob (psd_from_fs=false), or
 602  * 2. the ACL from the fs (psd_from_fs=true), or
 603  * 3. NULL (!)
 604  *
 605  * If the return value is anything else then NT_STATUS_OK, ppsd is set to NULL
 606  * and psd_from_fs set to false.
 607  *
 608  * Returning the underlying filesystem ACL in case no. 2 is really just an
 609  * optimisation, because some validations have to fetch the filesytem ACL as
 610  * part of the validation, so we already have it available and callers might
 611  * need it as well.
 612  **/
 613 static NTSTATUS validate_nt_acl_blob(TALLOC_CTX *mem_ctx,
 614                                      vfs_handle_struct *handle,
 615                                      files_struct *fsp,
 616                                      const struct smb_filename *smb_fname,
 617                                      const DATA_BLOB *blob,
 618                                      struct security_descriptor **ppsd,
 619                                      bool *psd_is_from_fs)
 620 {
 621         NTSTATUS status;
 622         uint16_t hash_type = XATTR_SD_HASH_TYPE_NONE;
 623         uint16_t xattr_version = 0;
 624         uint8_t hash[XATTR_SD_HASH_SIZE];
 625         uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE];
 626         uint8_t hash_tmp[XATTR_SD_HASH_SIZE];
 627         uint8_t sys_acl_hash_tmp[XATTR_SD_HASH_SIZE];
 628         struct security_descriptor *psd = NULL;
 629         struct security_descriptor *psd_blob = NULL;
 630         struct security_descriptor *psd_fs = NULL;
 631         char *sys_acl_blob_description = NULL;
 632         DATA_BLOB sys_acl_blob = { 0 };
 633         struct acl_common_config *config = NULL;
 634
 635         *ppsd = NULL;
 636         *psd_is_from_fs = false;
 637
 638         SMB_VFS_HANDLE_GET_DATA(handle, config,
 639                                 struct acl_common_config,
 640                                 return NT_STATUS_UNSUCCESSFUL);
 641
 642         status = parse_acl_blob(blob,
 643                                 mem_ctx,
 644                                 &psd_blob,
 645                                 &hash_type,
 646                                 &xattr_version,
 647                                 &hash[0],
 648                                 &sys_acl_hash[0]);
 649         if (!NT_STATUS_IS_OK(status)) {
 650                 DBG_DEBUG("parse_acl_blob returned %s\n", nt_errstr(status));
 651                 goto fail;
 652         }
 653
 654         /* determine which type of xattr we got */
 655         switch (xattr_version) {
 656         case 1:
 657         case 2:
 658                 /* These xattr types are unilatteral, they do not
 659                  * require confirmation of the hash.  In particular,
 660                  * the NTVFS file server uses version 1, but
 661                  * 'samba-tool ntacl' can set these as well */
 662                 *ppsd = psd_blob;
 663                 return NT_STATUS_OK;
 664         case 3:
 665         case 4:
 666                 if (config->ignore_system_acls) {
 667                         *ppsd = psd_blob;
 668                         return NT_STATUS_OK;
 669                 }
 670
 671                 break;
 672         default:
 673                 DBG_DEBUG("ACL blob revision mismatch (%u) for file %s\n",
 674                           (unsigned int)hash_type, smb_fname->base_name);
 675                 TALLOC_FREE(psd_blob);
 676                 return NT_STATUS_OK;
 677         }
 678
 679         /* determine which type of xattr we got */
 680         if (hash_type != XATTR_SD_HASH_TYPE_SHA256) {
 681                 DBG_DEBUG("ACL blob hash type (%u) unexpected for file %s\n",
 682                           (unsigned int)hash_type, smb_fname->base_name);
 683                 TALLOC_FREE(psd_blob);
 684                 return NT_STATUS_OK;
 685         }
 686
 687         /* determine which type of xattr we got */
 688         switch (xattr_version) {
 689         case 4:
 690         {
 691                 int ret;
 692                 if (fsp) {
 693                         /* Get the full underlying sd, then hash. */
 694                         ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FD(handle,
 695                                                                fsp,
 696                                                                mem_ctx,
 697                                                                &sys_acl_blob_description,
 698                                                                &sys_acl_blob);
 699                 } else {
 700                         /* Get the full underlying sd, then hash. */
 701                         ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FILE(handle,
 702                                                  smb_fname,
 703                                                  mem_ctx,
 704                                                  &sys_acl_blob_description,
 705                                                  &sys_acl_blob);
 706                 }
 707
 708                 /* If we fail to get the ACL blob (for some reason) then this
 709                  * is not fatal, we just work based on the NT ACL only */
 710                 if (ret == 0) {
 711                         status = hash_blob_sha256(sys_acl_blob, sys_acl_hash_tmp);
 712                         if (!NT_STATUS_IS_OK(status)) {
 713                                 goto fail;
 714                         }
 715
 716                         TALLOC_FREE(sys_acl_blob_description);
 717                         TALLOC_FREE(sys_acl_blob.data);
 718
 719                         if (memcmp(&sys_acl_hash[0], &sys_acl_hash_tmp[0],
 720                                    XATTR_SD_HASH_SIZE) == 0) {
 721                                 /* Hash matches, return blob sd. */
 722                                 DBG_DEBUG("blob hash matches for file %s\n",
 723                                           smb_fname->base_name);
 724                                 *ppsd = psd_blob;
 725                                 return NT_STATUS_OK;
 726                         }
 727                 }
 728
 729                 /* Otherwise, fall though and see if the NT ACL hash matches */
 730         }
 731         case 3:
 732                 /* Get the full underlying sd for the hash
 733                    or to return as backup. */
 734                 if (fsp) {
 735                         status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
 736                                                           fsp,
 737                                                           HASH_SECURITY_INFO,
 738                                                           mem_ctx,
 739                                                           &psd_fs);
 740                 } else {
 741                         status = SMB_VFS_NEXT_GET_NT_ACL(handle,
 742                                                          smb_fname,
 743                                                          HASH_SECURITY_INFO,
 744                                                          mem_ctx,
 745                                                          &psd_fs);
 746                 }
 747
 748                 if (!NT_STATUS_IS_OK(status)) {
 749                         DBG_DEBUG("get_next_acl for file %s returned %s\n",
 750                                   smb_fname->base_name, nt_errstr(status));
 751                         goto fail;
 752                 }
 753
 754                 status = hash_sd_sha256(psd_fs, hash_tmp);
 755                 if (!NT_STATUS_IS_OK(status)) {
 756                         TALLOC_FREE(psd_blob);
 757                         *ppsd = psd_fs;
 758                         *psd_is_from_fs = true;
 759                         return NT_STATUS_OK;
 760                 }
 761
 762                 if (memcmp(&hash[0], &hash_tmp[0], XATTR_SD_HASH_SIZE) == 0) {
 763                         /* Hash matches, return blob sd. */
 764                         DBG_DEBUG("blob hash matches for file %s\n",
 765                                   smb_fname->base_name);
 766                         *ppsd = psd_blob;
 767                         return NT_STATUS_OK;
 768                 }
 769
 770                 /* Hash doesn't match, return underlying sd. */
 771                 DBG_DEBUG("blob hash does not match for file %s - returning "
 772                           "file system SD mapping.\n",
 773                           smb_fname->base_name);
 774
 775                 if (DEBUGLEVEL >= 10) {
 776                         DBG_DEBUG("acl for blob hash for %s is:\n",
 777                                   smb_fname->base_name);
 778                         NDR_PRINT_DEBUG(security_descriptor, psd_fs);
 779                 }
 780
 781                 TALLOC_FREE(psd_blob);
 782                 *ppsd = psd_fs;
 783                 *psd_is_from_fs = true;
 784         }
 785
 786         return NT_STATUS_OK;
 787
 788 fail:
 789         TALLOC_FREE(psd);
 790         TALLOC_FREE(psd_blob);
 791         TALLOC_FREE(psd_fs);
 792         TALLOC_FREE(sys_acl_blob_description);
 793         TALLOC_FREE(sys_acl_blob.data);
 794         return status;
 795 }
 796
 797 static NTSTATUS stat_fsp_or_smb_fname(vfs_handle_struct *handle,
 798                                       files_struct *fsp,
 799                                       const struct smb_filename *smb_fname,
 800                                       SMB_STRUCT_STAT *sbuf,
 801                                       SMB_STRUCT_STAT **psbuf)
 802 {
 803         NTSTATUS status;
 804         int ret;
 805
 806         if (fsp) {
 807                 status = vfs_stat_fsp(fsp);
 808                 if (!NT_STATUS_IS_OK(status)) {
 809                         return status;
 810                 }
 811                 *psbuf = &fsp->fsp_name->st;
 812         } else {
 813                 /*
 814                  * https://bugzilla.samba.org/show_bug.cgi?id=11249
 815                  *
 816                  * We are currently guaranteed that 'name' here is a
 817                  * smb_fname->base_name, which *cannot* contain a stream name
 818                  * (':'). vfs_stat_smb_fname() splits a name into a base name +
 819                  * stream name, which when we get here we know we've already
 820                  * done.  So we have to call the stat or lstat VFS calls
 821                  * directly here. Else, a base_name that contains a ':' (from a
 822                  * demangled name) will get split again.
 823                  *
 824                  * FIXME.
 825                  * This uglyness will go away once smb_fname is fully plumbed
 826                  * through the VFS.
 827                  */
 828                 ret = vfs_stat_smb_basename(handle->conn,
 829                                             smb_fname,
 830                                             sbuf);
 831                 if (ret == -1) {
 832                         return map_nt_error_from_unix(errno);
 833                 }
 834         }
 835
 836         return NT_STATUS_OK;
 837 }
 838
 839 /*******************************************************************
 840  Pull a DATA_BLOB from an xattr given a pathname.
 841  If the hash doesn't match, or doesn't exist - return the underlying
 842  filesystem sd.
 843 *******************************************************************/
 844
 845 NTSTATUS get_nt_acl_common(
 846         NTSTATUS (*get_acl_blob_fn)(TALLOC_CTX *ctx,
 847                                     vfs_handle_struct *handle,
 848                                     files_struct *fsp,
 849                                     const struct smb_filename *smb_fname,
 850                                     DATA_BLOB *pblob),
 851         vfs_handle_struct *handle,
 852         files_struct *fsp,
 853         const struct smb_filename *smb_fname_in,
 854         uint32_t security_info,
 855         TALLOC_CTX *mem_ctx,
 856         struct security_descriptor **ppdesc)
 857 {
 858         DATA_BLOB blob = data_blob_null;
 859         NTSTATUS status;
 860         struct security_descriptor *psd = NULL;
 861         const struct smb_filename *smb_fname = NULL;
 862         bool psd_is_from_fs = false;
 863         struct acl_common_config *config = NULL;
 864
 865         SMB_VFS_HANDLE_GET_DATA(handle, config,
 866                                 struct acl_common_config,
 867                                 return NT_STATUS_UNSUCCESSFUL);
 868
 869         if (fsp && smb_fname_in == NULL) {
 870                 smb_fname = fsp->fsp_name;
 871         } else {
 872                 smb_fname = smb_fname_in;
 873         }
 874
 875         DBG_DEBUG("name=%s\n", smb_fname->base_name);
 876
 877         status = get_acl_blob_fn(mem_ctx, handle, fsp, smb_fname, &blob);
 878         if (NT_STATUS_IS_OK(status)) {
 879                 status = validate_nt_acl_blob(mem_ctx,
 880                                               handle,
 881                                               fsp,
 882                                               smb_fname,
 883                                               &blob,
 884                                               &psd,
 885                                               &psd_is_from_fs);
 886                 TALLOC_FREE(blob.data);
 887                 if (!NT_STATUS_IS_OK(status)) {
 888                         DBG_DEBUG("ACL validation for [%s] failed\n",
 889                                   smb_fname->base_name);
 890                         goto fail;
 891                 }
 892         }
 893
 894         if (psd == NULL) {
 895                 /* Get the full underlying sd, as we failed to get the
 896                  * blob for the hash, or the revision/hash type wasn't
 897                  * known */
 898
 899                 if (config->ignore_system_acls) {
 900                         SMB_STRUCT_STAT sbuf;
 901                         SMB_STRUCT_STAT *psbuf = &sbuf;
 902
 903                         status = stat_fsp_or_smb_fname(handle, fsp, smb_fname,
 904                                                        &sbuf, &psbuf);
 905                         if (!NT_STATUS_IS_OK(status)) {
 906                                 goto fail;
 907                         }
 908
 909                         status = make_default_filesystem_acl(
 910                                 mem_ctx,
 911                                 config->default_acl_style,
 912                                 smb_fname->base_name,
 913                                 psbuf,
 914                                 &psd);
 915                         if (!NT_STATUS_IS_OK(status)) {
 916                                 goto fail;
 917                         }
 918                 } else {
 919                         if (fsp) {
 920                                 status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
 921                                                                   fsp,
 922                                                                   security_info,
 923                                                                   mem_ctx,
 924                                                                   &psd);
 925                         } else {
 926                                 status = SMB_VFS_NEXT_GET_NT_ACL(handle,
 927                                                                  smb_fname,
 928                                                                  security_info,
 929                                                                  mem_ctx,
 930                                                                  &psd);
 931                         }
 932
 933                         if (!NT_STATUS_IS_OK(status)) {
 934                                 DBG_DEBUG("get_next_acl for file %s "
 935                                           "returned %s\n",
 936                                           smb_fname->base_name,
 937                                           nt_errstr(status));
 938                                 goto fail;
 939                         }
 940
 941                         psd_is_from_fs = true;
 942                 }
 943         }
 944
 945         if (psd_is_from_fs) {
 946                 SMB_STRUCT_STAT sbuf;
 947                 SMB_STRUCT_STAT *psbuf = &sbuf;
 948                 bool is_directory = false;
 949
 950                 /*
 951                  * We're returning the underlying ACL from the
 952                  * filesystem. If it's a directory, and has no
 953                  * inheritable ACE entries we have to fake them.
 954                  */
 955
 956                 status = stat_fsp_or_smb_fname(handle, fsp, smb_fname,
 957                                                &sbuf, &psbuf);
 958                 if (!NT_STATUS_IS_OK(status)) {
 959                         goto fail;
 960                 }
 961
 962                 is_directory = S_ISDIR(psbuf->st_ex_mode);
 963
 964                 if (is_directory && !sd_has_inheritable_components(psd, true)) {
 965                         status = add_directory_inheritable_components(
 966                                 handle,
 967                                 smb_fname->base_name,
 968                                 psbuf,
 969                                 psd);
 970                         if (!NT_STATUS_IS_OK(status)) {
 971                                 goto fail;
 972                         }
 973                 }
 974
 975                 /*
 976                  * The underlying POSIX module always sets the
 977                  * ~SEC_DESC_DACL_PROTECTED bit, as ACLs can't be inherited in
 978                  * this way under POSIX. Remove it for Windows-style ACLs.
 979                  */
 980                 psd->type &= ~SEC_DESC_DACL_PROTECTED;
 981         }
 982
 983         if (!(security_info & SECINFO_OWNER)) {
 984                 psd->owner_sid = NULL;
 985         }
 986         if (!(security_info & SECINFO_GROUP)) {
 987                 psd->group_sid = NULL;
 988         }
 989         if (!(security_info & SECINFO_DACL)) {
 990                 psd->type &= ~SEC_DESC_DACL_PRESENT;
 991                 psd->dacl = NULL;
 992         }
 993         if (!(security_info & SECINFO_SACL)) {
 994                 psd->type &= ~SEC_DESC_SACL_PRESENT;
 995                 psd->sacl = NULL;
 996         }
 997
 998         if (DEBUGLEVEL >= 10) {
 999                 DBG_DEBUG("returning acl for %s is:\n",
1000                           smb_fname->base_name);
1001                 NDR_PRINT_DEBUG(security_descriptor, psd);
1002         }
1003
1004         *ppdesc = psd;
1005
1006         return NT_STATUS_OK;
1007
1008 fail:
1009         TALLOC_FREE(psd);
1010         return status;
1011 }
1012
1013 /*********************************************************************
1014  Set the underlying ACL (e.g. POSIX ACLS, POSIX owner, etc)
1015 *********************************************************************/
1016 static NTSTATUS set_underlying_acl(vfs_handle_struct *handle, files_struct *fsp,
1017                                    struct security_descriptor *psd,
1018                                    uint32_t security_info_sent,
1019                                    bool chown_needed)
1020 {
1021         NTSTATUS status;
1022         const struct security_token *token = NULL;
1023
1024         status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp, security_info_sent, psd);
1025         if (!NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) {
1026                 return status;
1027         }
1028
1029         /* We got access denied here. If we're already root,
1030            or we didn't need to do a chown, or the fsp isn't
1031            open with WRITE_OWNER access, just return. */
1032         if (get_current_uid(handle->conn) == 0 || chown_needed == false ||
1033             !(fsp->access_mask & SEC_STD_WRITE_OWNER)) {
1034                 return NT_STATUS_ACCESS_DENIED;
1035         }
1036
1037         /*
1038          * Only allow take-ownership, not give-ownership. That's the way Windows
1039          * implements SEC_STD_WRITE_OWNER. MS-FSA 2.1.5.16 just states: If
1040          * InputBuffer.OwnerSid is not a valid owner SID for a file in the
1041          * objectstore, as determined in an implementation specific manner, the
1042          * object store MUST return STATUS_INVALID_OWNER.
1043          */
1044         token = get_current_nttok(fsp->conn);
1045         if (!security_token_is_sid(token, psd->owner_sid)) {
1046                 return NT_STATUS_INVALID_OWNER;
1047         }
1048
1049         DBG_DEBUG("overriding chown on file %s for sid %s\n",
1050                    fsp_str_dbg(fsp), sid_string_tos(psd->owner_sid));
1051
1052         /* Ok, we failed to chown and we have
1053            SEC_STD_WRITE_OWNER access - override. */
1054         become_root();
1055         status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp, security_info_sent, psd);
1056         unbecome_root();
1057
1058         return status;
1059 }
1060
1061 /*********************************************************************
1062  Store a v3 security descriptor
1063 *********************************************************************/
1064 static NTSTATUS store_v3_blob(
1065         NTSTATUS (*store_acl_blob_fsp_fn)(vfs_handle_struct *handle,
1066                                           files_struct *fsp,
1067                                           DATA_BLOB *pblob),
1068         vfs_handle_struct *handle, files_struct *fsp,
1069         struct security_descriptor *psd,
1070         struct security_descriptor *pdesc_next,
1071         uint8_t hash[XATTR_SD_HASH_SIZE])
1072 {
1073         NTSTATUS status;
1074         DATA_BLOB blob;
1075
1076         if (DEBUGLEVEL >= 10) {
1077                 DBG_DEBUG("storing xattr sd for file %s\n",
1078                           fsp_str_dbg(fsp));
1079                 NDR_PRINT_DEBUG(
1080                     security_descriptor,
1081                     discard_const_p(struct security_descriptor, psd));
1082
1083                 if (pdesc_next != NULL) {
1084                         DBG_DEBUG("storing xattr sd based on \n");
1085                         NDR_PRINT_DEBUG(
1086                             security_descriptor,
1087                             discard_const_p(struct security_descriptor,
1088                                             pdesc_next));
1089                 } else {
1090                         DBG_DEBUG("ignoring underlying sd\n");
1091                 }
1092         }
1093         status = create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash);
1094         if (!NT_STATUS_IS_OK(status)) {
1095                 DBG_DEBUG("create_acl_blob failed\n");
1096                 return status;
1097         }
1098
1099         status = store_acl_blob_fsp_fn(handle, fsp, &blob);
1100         return status;
1101 }
1102
1103 /*********************************************************************
1104  Store a security descriptor given an fsp.
1105 *********************************************************************/
1106
1107 NTSTATUS fset_nt_acl_common(
1108         NTSTATUS (*get_acl_blob_fn)(TALLOC_CTX *ctx,
1109                                     vfs_handle_struct *handle,
1110                                     files_struct *fsp,
1111                                     const struct smb_filename *smb_fname,
1112                                     DATA_BLOB *pblob),
1113         NTSTATUS (*store_acl_blob_fsp_fn)(vfs_handle_struct *handle,
1114                                           files_struct *fsp,
1115                                           DATA_BLOB *pblob),
1116         const char *module_name,
1117         vfs_handle_struct *handle, files_struct *fsp,
1118         uint32_t security_info_sent,
1119         const struct security_descriptor *orig_psd)
1120 {
1121         NTSTATUS status;
1122         int ret;
1123         DATA_BLOB blob, sys_acl_blob;
1124         struct security_descriptor *pdesc_next = NULL;
1125         struct security_descriptor *psd = NULL;
1126         uint8_t hash[XATTR_SD_HASH_SIZE];
1127         uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE];
1128         bool chown_needed = false;
1129         char *sys_acl_description;
1130         TALLOC_CTX *frame = talloc_stackframe();
1131         bool ignore_file_system_acl = lp_parm_bool(
1132             SNUM(handle->conn), module_name, "ignore system acls", false);
1133
1134         if (DEBUGLEVEL >= 10) {
1135                 DBG_DEBUG("incoming sd for file %s\n", fsp_str_dbg(fsp));
1136                 NDR_PRINT_DEBUG(security_descriptor,
1137                         discard_const_p(struct security_descriptor, orig_psd));
1138         }
1139
1140         status = get_nt_acl_common(get_acl_blob_fn, handle, fsp,
1141                         NULL,
1142                         SECINFO_OWNER|SECINFO_GROUP|SECINFO_DACL|SECINFO_SACL,
1143                                      frame,
1144                         &psd);
1145
1146         if (!NT_STATUS_IS_OK(status)) {
1147                 TALLOC_FREE(frame);
1148                 return status;
1149         }
1150
1151         psd->revision = orig_psd->revision;
1152         /* All our SD's are self relative. */
1153         psd->type = orig_psd->type | SEC_DESC_SELF_RELATIVE;
1154
1155         if ((security_info_sent & SECINFO_OWNER) && (orig_psd->owner_sid != NULL)) {
1156                 if (!dom_sid_equal(orig_psd->owner_sid, psd->owner_sid)) {
1157                         /* We're changing the owner. */
1158                         chown_needed = true;
1159                 }
1160                 psd->owner_sid = orig_psd->owner_sid;
1161         }
1162         if ((security_info_sent & SECINFO_GROUP) && (orig_psd->group_sid != NULL)) {
1163                 if (!dom_sid_equal(orig_psd->group_sid, psd->group_sid)) {
1164                         /* We're changing the group. */
1165                         chown_needed = true;
1166                 }
1167                 psd->group_sid = orig_psd->group_sid;
1168         }
1169         if (security_info_sent & SECINFO_DACL) {
1170                 if (security_descriptor_with_ms_nfs(orig_psd)) {
1171                         /*
1172                          * If the sd contains a MS NFS SID, do
1173                          * nothing, it's a chmod() request from OS X
1174                          * with AAPL context.
1175                          */
1176                         TALLOC_FREE(frame);
1177                         return NT_STATUS_OK;
1178                 }
1179                 psd->dacl = orig_psd->dacl;
1180                 psd->type |= SEC_DESC_DACL_PRESENT;
1181         }
1182         if (security_info_sent & SECINFO_SACL) {
1183                 psd->sacl = orig_psd->sacl;
1184                 psd->type |= SEC_DESC_SACL_PRESENT;
1185         }
1186
1187         if (ignore_file_system_acl) {
1188                 if (chown_needed) {
1189                         /* send only ownership stuff to lower layer */
1190                         security_info_sent &= (SECINFO_OWNER | SECINFO_GROUP);
1191                         status = set_underlying_acl(handle, fsp, psd,
1192                                                     security_info_sent, true);
1193                         if (!NT_STATUS_IS_OK(status)) {
1194                                 TALLOC_FREE(frame);
1195                                 return status;
1196                         }
1197                 }
1198                 ZERO_ARRAY(hash);
1199                 status = store_v3_blob(store_acl_blob_fsp_fn, handle, fsp, psd,
1200                                        NULL, hash);
1201
1202                 TALLOC_FREE(frame);
1203                 return status;
1204         }
1205
1206         status = set_underlying_acl(handle, fsp, psd, security_info_sent,
1207                                     chown_needed);
1208         if (!NT_STATUS_IS_OK(status)) {
1209                 TALLOC_FREE(frame);
1210                 return status;
1211         }
1212
1213         /* Get the full underlying sd, then hash. */
1214         status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
1215                                           fsp,
1216                                           HASH_SECURITY_INFO,
1217                                           frame,
1218                                           &pdesc_next);
1219
1220         if (!NT_STATUS_IS_OK(status)) {
1221                 TALLOC_FREE(frame);
1222                 return status;
1223         }
1224
1225         status = hash_sd_sha256(pdesc_next, hash);
1226         if (!NT_STATUS_IS_OK(status)) {
1227                 TALLOC_FREE(frame);
1228                 return status;
1229         }
1230
1231         /* Get the full underlying sd, then hash. */
1232         ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FD(handle,
1233                                                fsp,
1234                                                frame,
1235                                                &sys_acl_description,
1236                                                &sys_acl_blob);
1237
1238         /* If we fail to get the ACL blob (for some reason) then this
1239          * is not fatal, we just work based on the NT ACL only */
1240         if (ret != 0) {
1241                 status = store_v3_blob(store_acl_blob_fsp_fn, handle, fsp, psd,
1242                                        pdesc_next, hash);
1243
1244                 TALLOC_FREE(frame);
1245                 return status;
1246         }
1247
1248         status = hash_blob_sha256(sys_acl_blob, sys_acl_hash);
1249         if (!NT_STATUS_IS_OK(status)) {
1250                 TALLOC_FREE(frame);
1251                 return status;
1252         }
1253
1254         if (DEBUGLEVEL >= 10) {
1255                 DBG_DEBUG("storing xattr sd for file %s based on system ACL\n",
1256                           fsp_str_dbg(fsp));
1257                 NDR_PRINT_DEBUG(security_descriptor,
1258                                 discard_const_p(struct security_descriptor, psd));
1259
1260                 DBG_DEBUG("storing hash in xattr sd based on system ACL and:\n");
1261                 NDR_PRINT_DEBUG(security_descriptor,
1262                                 discard_const_p(struct security_descriptor, pdesc_next));
1263         }
1264
1265         /* We store hashes of both the sys ACL blob and the NT
1266          * security desciptor mapped from that ACL so as to improve
1267          * our chances against some inadvertant change breaking the
1268          * hash used */
1269         status = create_sys_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash,
1270                                      sys_acl_description, sys_acl_hash);
1271         if (!NT_STATUS_IS_OK(status)) {
1272                 DBG_DEBUG("create_sys_acl_blob failed\n");
1273                 TALLOC_FREE(frame);
1274                 return status;
1275         }
1276
1277         status = store_acl_blob_fsp_fn(handle, fsp, &blob);
1278
1279         TALLOC_FREE(frame);
1280         return status;
1281 }
1282
1283 static int acl_common_remove_object(vfs_handle_struct *handle,
1284                                         const struct smb_filename *smb_fname,
1285                                         bool is_directory)
1286 {
1287         connection_struct *conn = handle->conn;
1288         struct file_id id;
1289         files_struct *fsp = NULL;
1290         int ret = 0;
1291         char *parent_dir = NULL;
1292         const char *final_component = NULL;
1293         struct smb_filename local_fname = {0};
1294         struct smb_filename parent_dir_fname = {0};
1295         int saved_errno = 0;
1296         struct smb_filename *saved_dir_fname = NULL;
1297
1298         saved_dir_fname = vfs_GetWd(talloc_tos(),conn);
1299         if (saved_dir_fname == NULL) {
1300                 saved_errno = errno;
1301                 goto out;
1302         }
1303
1304         if (!parent_dirname(talloc_tos(), smb_fname->base_name,
1305                         &parent_dir, &final_component)) {
1306                 saved_errno = ENOMEM;
1307                 goto out;
1308         }
1309
1310         DBG_DEBUG("removing %s %s/%s\n", is_directory ? "directory" : "file",
1311                   parent_dir, final_component);
1312
1313         parent_dir_fname = (struct smb_filename) { .base_name = parent_dir };
1314
1315         /* cd into the parent dir to pin it. */
1316         ret = vfs_ChDir(conn, &parent_dir_fname);
1317         if (ret == -1) {
1318                 saved_errno = errno;
1319                 goto out;
1320         }
1321
1322         local_fname.base_name = discard_const_p(char, final_component);
1323
1324         /* Must use lstat here. */
1325         ret = SMB_VFS_LSTAT(conn, &local_fname);
1326         if (ret == -1) {
1327                 saved_errno = errno;
1328                 goto out;
1329         }
1330
1331         /* Ensure we have this file open with DELETE access. */
1332         id = vfs_file_id_from_sbuf(conn, &local_fname.st);
1333         for (fsp = file_find_di_first(conn->sconn, id); fsp;
1334                      fsp = file_find_di_next(fsp)) {
1335                 if (fsp->access_mask & DELETE_ACCESS &&
1336                                 fsp->delete_on_close) {
1337                         /* We did open this for delete,
1338                          * allow the delete as root.
1339                          */
1340                         break;
1341                 }
1342         }
1343
1344         if (!fsp) {
1345                 DBG_DEBUG("%s %s/%s not an open file\n",
1346                           is_directory ? "directory" : "file",
1347                           parent_dir, final_component);
1348                 saved_errno = EACCES;
1349                 goto out;
1350         }
1351
1352         become_root();
1353         if (is_directory) {
1354                 ret = SMB_VFS_NEXT_RMDIR(handle, &local_fname);
1355         } else {
1356                 ret = SMB_VFS_NEXT_UNLINK(handle, &local_fname);
1357         }
1358         unbecome_root();
1359
1360         if (ret == -1) {
1361                 saved_errno = errno;
1362         }
1363
1364   out:
1365
1366         TALLOC_FREE(parent_dir);
1367
1368         if (saved_dir_fname) {
1369                 vfs_ChDir(conn, saved_dir_fname);
1370                 TALLOC_FREE(saved_dir_fname);
1371         }
1372         if (saved_errno) {
1373                 errno = saved_errno;
1374         }
1375         return ret;
1376 }
1377
1378 int rmdir_acl_common(struct vfs_handle_struct *handle,
1379                      const struct smb_filename *smb_fname)
1380 {
1381         int ret;
1382
1383         /* Try the normal rmdir first. */
1384         ret = SMB_VFS_NEXT_RMDIR(handle, smb_fname);
1385         if (ret == 0) {
1386                 return 0;
1387         }
1388         if (errno == EACCES || errno == EPERM) {
1389                 /* Failed due to access denied,
1390                    see if we need to root override. */
1391                 return acl_common_remove_object(handle,
1392                                                 smb_fname,
1393                                                 true);
1394         }
1395
1396         DBG_DEBUG("unlink of %s failed %s\n",
1397                   smb_fname->base_name,
1398                   strerror(errno));
1399         return -1;
1400 }
1401
1402 int unlink_acl_common(struct vfs_handle_struct *handle,
1403                         const struct smb_filename *smb_fname)
1404 {
1405         int ret;
1406
1407         /* Try the normal unlink first. */
1408         ret = SMB_VFS_NEXT_UNLINK(handle, smb_fname);
1409         if (ret == 0) {
1410                 return 0;
1411         }
1412         if (errno == EACCES || errno == EPERM) {
1413                 /* Failed due to access denied,
1414                    see if we need to root override. */
1415
1416                 /* Don't do anything fancy for streams. */
1417                 if (smb_fname->stream_name) {
1418                         return -1;
1419                 }
1420                 return acl_common_remove_object(handle,
1421                                         smb_fname,
1422                                         false);
1423         }
1424
1425         DBG_DEBUG("unlink of %s failed %s\n",
1426                   smb_fname->base_name,
1427                   strerror(errno));
1428         return -1;
1429 }
1430
1431 int chmod_acl_module_common(struct vfs_handle_struct *handle,
1432                             const struct smb_filename *smb_fname,
1433                             mode_t mode)
1434 {
1435         if (smb_fname->flags & SMB_FILENAME_POSIX_PATH) {
1436                 /* Only allow this on POSIX pathnames. */
1437                 return SMB_VFS_NEXT_CHMOD(handle, smb_fname, mode);
1438         }
1439         return 0;
1440 }
1441
1442 int fchmod_acl_module_common(struct vfs_handle_struct *handle,
1443                              struct files_struct *fsp, mode_t mode)
1444 {
1445         if (fsp->posix_flags & FSP_POSIX_FLAGS_OPEN) {
1446                 /* Only allow this on POSIX opens. */
1447                 return SMB_VFS_NEXT_FCHMOD(handle, fsp, mode);
1448         }
1449         return 0;
1450 }
1451
1452 int chmod_acl_acl_module_common(struct vfs_handle_struct *handle,
1453                                 const struct smb_filename *smb_fname,
1454                                 mode_t mode)
1455 {
1456         if (smb_fname->flags & SMB_FILENAME_POSIX_PATH) {
1457                 /* Only allow this on POSIX pathnames. */
1458                 return SMB_VFS_NEXT_CHMOD_ACL(handle, smb_fname, mode);
1459         }
1460         return 0;
1461 }
1462
1463 int fchmod_acl_acl_module_common(struct vfs_handle_struct *handle,
1464                                  struct files_struct *fsp, mode_t mode)
1465 {
1466         if (fsp->posix_flags & FSP_POSIX_FLAGS_OPEN) {
1467                 /* Only allow this on POSIX opens. */
1468                 return SMB_VFS_NEXT_FCHMOD_ACL(handle, fsp, mode);
1469         }
1470         return 0;
1471 }