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 "smbd/smbd.h"
  24 #include "system/filesys.h"
  25 #include "../libcli/security/security.h"
  26 #include "../librpc/gen_ndr/ndr_security.h"
  27 #include "../lib/util/bitmap.h"
  28 #include "passdb/lookup_sid.h"
  29
  30 static NTSTATUS create_acl_blob(const struct security_descriptor *psd,
  31                         DATA_BLOB *pblob,
  32                         uint16_t hash_type,
  33                         uint8_t hash[XATTR_SD_HASH_SIZE]);
  34
  35 static NTSTATUS get_acl_blob(TALLOC_CTX *ctx,
  36                         vfs_handle_struct *handle,
  37                         files_struct *fsp,
  38                         const struct smb_filename *smb_fname,
  39                         DATA_BLOB *pblob);
  40
  41 static NTSTATUS store_acl_blob_fsp(vfs_handle_struct *handle,
  42                         files_struct *fsp,
  43                         DATA_BLOB *pblob);
  44
  45 #define HASH_SECURITY_INFO (SECINFO_OWNER | \
  46                                 SECINFO_GROUP | \
  47                                 SECINFO_DACL | \
  48                                 SECINFO_SACL)
  49
  50 enum default_acl_style {DEFAULT_ACL_POSIX, DEFAULT_ACL_WINDOWS};
  51
  52 static const struct enum_list default_acl_style[] = {
  53         {DEFAULT_ACL_POSIX,     "posix"},
  54         {DEFAULT_ACL_WINDOWS,   "windows"}
  55 };
  56
  57 struct acl_common_config {
  58         bool ignore_system_acls;
  59         enum default_acl_style default_acl_style;
  60 };
  61
  62 static bool init_acl_common_config(vfs_handle_struct *handle)
  63 {
  64         struct acl_common_config *config = NULL;
  65
  66         config = talloc_zero(handle->conn, struct acl_common_config);
  67         if (config == NULL) {
  68                 DBG_ERR("talloc_zero() failed\n");
  69                 errno = ENOMEM;
  70                 return false;
  71         }
  72
  73         config->ignore_system_acls = lp_parm_bool(SNUM(handle->conn),
  74                                                   ACL_MODULE_NAME,
  75                                                   "ignore system acls",
  76                                                   false);
  77         config->default_acl_style = lp_parm_enum(SNUM(handle->conn),
  78                                                  ACL_MODULE_NAME,
  79                                                  "default acl style",
  80                                                  default_acl_style,
  81                                                  DEFAULT_ACL_POSIX);
  82
  83         SMB_VFS_HANDLE_SET_DATA(handle, config, NULL,
  84                                 struct acl_common_config,
  85                                 return false);
  86
  87         return true;
  88 }
  89
  90
  91 /*******************************************************************
  92  Hash a security descriptor.
  93 *******************************************************************/
  94
  95 static NTSTATUS hash_blob_sha256(DATA_BLOB blob,
  96                                  uint8_t *hash)
  97 {
  98         SHA256_CTX tctx;
  99
 100         memset(hash, '\0', XATTR_SD_HASH_SIZE);
 101
 102         samba_SHA256_Init(&tctx);
 103         samba_SHA256_Update(&tctx, blob.data, blob.length);
 104         samba_SHA256_Final(hash, &tctx);
 105
 106         return NT_STATUS_OK;
 107 }
 108
 109 /*******************************************************************
 110  Hash a security descriptor.
 111 *******************************************************************/
 112
 113 static NTSTATUS hash_sd_sha256(struct security_descriptor *psd,
 114                         uint8_t *hash)
 115 {
 116         DATA_BLOB blob;
 117         NTSTATUS status;
 118
 119         memset(hash, '\0', XATTR_SD_HASH_SIZE);
 120         status = create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash);
 121         if (!NT_STATUS_IS_OK(status)) {
 122                 return status;
 123         }
 124         return hash_blob_sha256(blob, hash);
 125 }
 126
 127 /*******************************************************************
 128  Parse out a struct security_descriptor from a DATA_BLOB.
 129 *******************************************************************/
 130
 131 static NTSTATUS parse_acl_blob(const DATA_BLOB *pblob,
 132                                TALLOC_CTX *mem_ctx,
 133                                struct security_descriptor **ppdesc,
 134                                uint16_t *p_hash_type,
 135                                uint16_t *p_version,
 136                                uint8_t hash[XATTR_SD_HASH_SIZE],
 137                                uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE])
 138 {
 139         struct xattr_NTACL xacl;
 140         enum ndr_err_code ndr_err;
 141         size_t sd_size;
 142         TALLOC_CTX *frame = talloc_stackframe();
 143
 144         ndr_err = ndr_pull_struct_blob(pblob, frame, &xacl,
 145                         (ndr_pull_flags_fn_t)ndr_pull_xattr_NTACL);
 146
 147         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 148                 DBG_INFO("ndr_pull_xattr_NTACL failed: %s\n",
 149                          ndr_errstr(ndr_err));
 150                 TALLOC_FREE(frame);
 151                 return ndr_map_error2ntstatus(ndr_err);
 152         }
 153
 154         *p_version = xacl.version;
 155
 156         switch (xacl.version) {
 157                 case 1:
 158                         *ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
 159                                         xacl.info.sd->type | SEC_DESC_SELF_RELATIVE,
 160                                         xacl.info.sd->owner_sid,
 161                                         xacl.info.sd->group_sid,
 162                                         xacl.info.sd->sacl,
 163                                         xacl.info.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 2:
 170                         *ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
 171                                         xacl.info.sd_hs2->sd->type | SEC_DESC_SELF_RELATIVE,
 172                                         xacl.info.sd_hs2->sd->owner_sid,
 173                                         xacl.info.sd_hs2->sd->group_sid,
 174                                         xacl.info.sd_hs2->sd->sacl,
 175                                         xacl.info.sd_hs2->sd->dacl,
 176                                         &sd_size);
 177                         /* No hash - null out. */
 178                         *p_hash_type = XATTR_SD_HASH_TYPE_NONE;
 179                         memset(hash, '\0', XATTR_SD_HASH_SIZE);
 180                         break;
 181                 case 3:
 182                         *ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
 183                                         xacl.info.sd_hs3->sd->type | SEC_DESC_SELF_RELATIVE,
 184                                         xacl.info.sd_hs3->sd->owner_sid,
 185                                         xacl.info.sd_hs3->sd->group_sid,
 186                                         xacl.info.sd_hs3->sd->sacl,
 187                                         xacl.info.sd_hs3->sd->dacl,
 188                                         &sd_size);
 189                         *p_hash_type = xacl.info.sd_hs3->hash_type;
 190                         /* Current version 3 (if no sys acl hash available). */
 191                         memcpy(hash, xacl.info.sd_hs3->hash, XATTR_SD_HASH_SIZE);
 192                         break;
 193                 case 4:
 194                         *ppdesc = make_sec_desc(mem_ctx, SD_REVISION,
 195                                         xacl.info.sd_hs4->sd->type | SEC_DESC_SELF_RELATIVE,
 196                                         xacl.info.sd_hs4->sd->owner_sid,
 197                                         xacl.info.sd_hs4->sd->group_sid,
 198                                         xacl.info.sd_hs4->sd->sacl,
 199                                         xacl.info.sd_hs4->sd->dacl,
 200                                         &sd_size);
 201                         *p_hash_type = xacl.info.sd_hs4->hash_type;
 202                         /* Current version 4. */
 203                         memcpy(hash, xacl.info.sd_hs4->hash, XATTR_SD_HASH_SIZE);
 204                         memcpy(sys_acl_hash, xacl.info.sd_hs4->sys_acl_hash, XATTR_SD_HASH_SIZE);
 205                         break;
 206                 default:
 207                         TALLOC_FREE(frame);
 208                         return NT_STATUS_REVISION_MISMATCH;
 209         }
 210
 211         TALLOC_FREE(frame);
 212
 213         return (*ppdesc != NULL) ? NT_STATUS_OK : NT_STATUS_NO_MEMORY;
 214 }
 215
 216 /*******************************************************************
 217  Create a DATA_BLOB from a hash of the security descriptor storead at
 218  the system layer and the NT ACL we wish to preserve
 219 *******************************************************************/
 220
 221 static NTSTATUS create_acl_blob(const struct security_descriptor *psd,
 222                         DATA_BLOB *pblob,
 223                         uint16_t hash_type,
 224                         uint8_t hash[XATTR_SD_HASH_SIZE])
 225 {
 226         struct xattr_NTACL xacl;
 227         struct security_descriptor_hash_v3 sd_hs3;
 228         enum ndr_err_code ndr_err;
 229         TALLOC_CTX *ctx = talloc_tos();
 230
 231         ZERO_STRUCT(xacl);
 232         ZERO_STRUCT(sd_hs3);
 233
 234         xacl.version = 3;
 235         xacl.info.sd_hs3 = &sd_hs3;
 236         xacl.info.sd_hs3->sd = discard_const_p(struct security_descriptor, psd);
 237         xacl.info.sd_hs3->hash_type = hash_type;
 238         memcpy(&xacl.info.sd_hs3->hash[0], hash, XATTR_SD_HASH_SIZE);
 239
 240         ndr_err = ndr_push_struct_blob(
 241                         pblob, ctx, &xacl,
 242                         (ndr_push_flags_fn_t)ndr_push_xattr_NTACL);
 243
 244         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 245                 DBG_INFO("ndr_push_xattr_NTACL failed: %s\n",
 246                          ndr_errstr(ndr_err));
 247                 return ndr_map_error2ntstatus(ndr_err);
 248         }
 249
 250         return NT_STATUS_OK;
 251 }
 252
 253 /*******************************************************************
 254  Create a DATA_BLOB from a hash of the security descriptors
 255  (system and NT) stored at the system layer and the NT ACL we wish
 256  to preserve.
 257 *******************************************************************/
 258
 259 static NTSTATUS create_sys_acl_blob(const struct security_descriptor *psd,
 260                                     DATA_BLOB *pblob,
 261                                     uint16_t hash_type,
 262                                     uint8_t hash[XATTR_SD_HASH_SIZE],
 263                                     const char *description,
 264                                     uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE])
 265 {
 266         struct xattr_NTACL xacl;
 267         struct security_descriptor_hash_v4 sd_hs4;
 268         enum ndr_err_code ndr_err;
 269         TALLOC_CTX *ctx = talloc_tos();
 270         NTTIME nttime_now;
 271         struct timeval now = timeval_current();
 272         nttime_now = timeval_to_nttime(&now);
 273
 274         ZERO_STRUCT(xacl);
 275         ZERO_STRUCT(sd_hs4);
 276
 277         xacl.version = 4;
 278         xacl.info.sd_hs4 = &sd_hs4;
 279         xacl.info.sd_hs4->sd = discard_const_p(struct security_descriptor, psd);
 280         xacl.info.sd_hs4->hash_type = hash_type;
 281         memcpy(&xacl.info.sd_hs4->hash[0], hash, XATTR_SD_HASH_SIZE);
 282         xacl.info.sd_hs4->description = description;
 283         xacl.info.sd_hs4->time = nttime_now;
 284         memcpy(&xacl.info.sd_hs4->sys_acl_hash[0], sys_acl_hash, XATTR_SD_HASH_SIZE);
 285
 286         ndr_err = ndr_push_struct_blob(
 287                         pblob, ctx, &xacl,
 288                         (ndr_push_flags_fn_t)ndr_push_xattr_NTACL);
 289
 290         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
 291                 DBG_INFO("ndr_push_xattr_NTACL failed: %s\n",
 292                          ndr_errstr(ndr_err));
 293                 return ndr_map_error2ntstatus(ndr_err);
 294         }
 295
 296         return NT_STATUS_OK;
 297 }
 298
 299 /*******************************************************************
 300  Add in 3 inheritable components for a non-inheritable directory ACL.
 301  CREATOR_OWNER/CREATOR_GROUP/WORLD.
 302 *******************************************************************/
 303
 304 static NTSTATUS add_directory_inheritable_components(vfs_handle_struct *handle,
 305                                 const char *name,
 306                                 SMB_STRUCT_STAT *psbuf,
 307                                 struct security_descriptor *psd)
 308 {
 309         struct connection_struct *conn = handle->conn;
 310         int num_aces = (psd->dacl ? psd->dacl->num_aces : 0);
 311         struct smb_filename smb_fname;
 312         enum security_ace_type acltype;
 313         uint32_t access_mask;
 314         mode_t dir_mode;
 315         mode_t file_mode;
 316         mode_t mode;
 317         struct security_ace *new_ace_list;
 318
 319         if (psd->dacl) {
 320                 new_ace_list = talloc_zero_array(psd->dacl,
 321                                                  struct security_ace,
 322                                                  num_aces + 3);
 323         } else {
 324                 /*
 325                  * make_sec_acl() at the bottom of this function
 326                  * dupliates new_ace_list
 327                  */
 328                 new_ace_list = talloc_zero_array(talloc_tos(),
 329                                                  struct security_ace,
 330                                                  num_aces + 3);
 331         }
 332
 333         if (new_ace_list == NULL) {
 334                 return NT_STATUS_NO_MEMORY;
 335         }
 336
 337         /* Fake a quick smb_filename. */
 338         ZERO_STRUCT(smb_fname);
 339         smb_fname.st = *psbuf;
 340         smb_fname.base_name = discard_const_p(char, name);
 341
 342         dir_mode = unix_mode(conn,
 343                         FILE_ATTRIBUTE_DIRECTORY, &smb_fname, NULL);
 344         file_mode = unix_mode(conn,
 345                         FILE_ATTRIBUTE_ARCHIVE, &smb_fname, NULL);
 346
 347         mode = dir_mode | file_mode;
 348
 349         DBG_DEBUG("directory %s, mode = 0%o\n", name, (unsigned int)mode);
 350
 351         if (num_aces) {
 352                 memcpy(new_ace_list, psd->dacl->aces,
 353                         num_aces * sizeof(struct security_ace));
 354         }
 355         access_mask = map_canon_ace_perms(SNUM(conn), &acltype,
 356                                 mode & 0700, false);
 357
 358         init_sec_ace(&new_ace_list[num_aces],
 359                         &global_sid_Creator_Owner,
 360                         acltype,
 361                         access_mask,
 362                         SEC_ACE_FLAG_CONTAINER_INHERIT|
 363                                 SEC_ACE_FLAG_OBJECT_INHERIT|
 364                                 SEC_ACE_FLAG_INHERIT_ONLY);
 365         access_mask = map_canon_ace_perms(SNUM(conn), &acltype,
 366                                 (mode << 3) & 0700, false);
 367         init_sec_ace(&new_ace_list[num_aces+1],
 368                         &global_sid_Creator_Group,
 369                         acltype,
 370                         access_mask,
 371                         SEC_ACE_FLAG_CONTAINER_INHERIT|
 372                                 SEC_ACE_FLAG_OBJECT_INHERIT|
 373                                 SEC_ACE_FLAG_INHERIT_ONLY);
 374         access_mask = map_canon_ace_perms(SNUM(conn), &acltype,
 375                                 (mode << 6) & 0700, false);
 376         init_sec_ace(&new_ace_list[num_aces+2],
 377                         &global_sid_World,
 378                         acltype,
 379                         access_mask,
 380                         SEC_ACE_FLAG_CONTAINER_INHERIT|
 381                                 SEC_ACE_FLAG_OBJECT_INHERIT|
 382                                 SEC_ACE_FLAG_INHERIT_ONLY);
 383         if (psd->dacl) {
 384                 psd->dacl->aces = new_ace_list;
 385                 psd->dacl->num_aces += 3;
 386                 psd->dacl->size += new_ace_list[num_aces].size +
 387                         new_ace_list[num_aces+1].size +
 388                         new_ace_list[num_aces+2].size;
 389         } else {
 390                 psd->dacl = make_sec_acl(psd,
 391                                 NT4_ACL_REVISION,
 392                                 3,
 393                                 new_ace_list);
 394                 if (psd->dacl == NULL) {
 395                         return NT_STATUS_NO_MEMORY;
 396                 }
 397         }
 398         return NT_STATUS_OK;
 399 }
 400
 401 static NTSTATUS make_default_acl_posix(TALLOC_CTX *ctx,
 402                                        const char *name,
 403                                        SMB_STRUCT_STAT *psbuf,
 404                                        struct security_descriptor **ppdesc)
 405 {
 406         struct dom_sid owner_sid, group_sid;
 407         size_t size = 0;
 408         struct security_ace aces[4];
 409         uint32_t access_mask = 0;
 410         mode_t mode = psbuf->st_ex_mode;
 411         struct security_acl *new_dacl = NULL;
 412         int idx = 0;
 413
 414         DBG_DEBUG("file %s mode = 0%o\n",name, (int)mode);
 415
 416         uid_to_sid(&owner_sid, psbuf->st_ex_uid);
 417         gid_to_sid(&group_sid, psbuf->st_ex_gid);
 418
 419         /*
 420          We provide up to 4 ACEs
 421                 - Owner
 422                 - Group
 423                 - Everyone
 424                 - NT System
 425         */
 426
 427         if (mode & S_IRUSR) {
 428                 if (mode & S_IWUSR) {
 429                         access_mask |= SEC_RIGHTS_FILE_ALL;
 430                 } else {
 431                         access_mask |= SEC_RIGHTS_FILE_READ | SEC_FILE_EXECUTE;
 432                 }
 433         }
 434         if (mode & S_IWUSR) {
 435                 access_mask |= SEC_RIGHTS_FILE_WRITE | SEC_STD_DELETE;
 436         }
 437
 438         init_sec_ace(&aces[idx],
 439                         &owner_sid,
 440                         SEC_ACE_TYPE_ACCESS_ALLOWED,
 441                         access_mask,
 442                         0);
 443         idx++;
 444
 445         access_mask = 0;
 446         if (mode & S_IRGRP) {
 447                 access_mask |= SEC_RIGHTS_FILE_READ | SEC_FILE_EXECUTE;
 448         }
 449         if (mode & S_IWGRP) {
 450                 /* note that delete is not granted - this matches posix behaviour */
 451                 access_mask |= SEC_RIGHTS_FILE_WRITE;
 452         }
 453         if (access_mask) {
 454                 init_sec_ace(&aces[idx],
 455                         &group_sid,
 456                         SEC_ACE_TYPE_ACCESS_ALLOWED,
 457                         access_mask,
 458                         0);
 459                 idx++;
 460         }
 461
 462         access_mask = 0;
 463         if (mode & S_IROTH) {
 464                 access_mask |= SEC_RIGHTS_FILE_READ | SEC_FILE_EXECUTE;
 465         }
 466         if (mode & S_IWOTH) {
 467                 access_mask |= SEC_RIGHTS_FILE_WRITE;
 468         }
 469         if (access_mask) {
 470                 init_sec_ace(&aces[idx],
 471                         &global_sid_World,
 472                         SEC_ACE_TYPE_ACCESS_ALLOWED,
 473                         access_mask,
 474                         0);
 475                 idx++;
 476         }
 477
 478         init_sec_ace(&aces[idx],
 479                         &global_sid_System,
 480                         SEC_ACE_TYPE_ACCESS_ALLOWED,
 481                         SEC_RIGHTS_FILE_ALL,
 482                         0);
 483         idx++;
 484
 485         new_dacl = make_sec_acl(ctx,
 486                         NT4_ACL_REVISION,
 487                         idx,
 488                         aces);
 489
 490         if (!new_dacl) {
 491                 return NT_STATUS_NO_MEMORY;
 492         }
 493
 494         *ppdesc = make_sec_desc(ctx,
 495                         SECURITY_DESCRIPTOR_REVISION_1,
 496                         SEC_DESC_SELF_RELATIVE|SEC_DESC_DACL_PRESENT,
 497                         &owner_sid,
 498                         &group_sid,
 499                         NULL,
 500                         new_dacl,
 501                         &size);
 502         if (!*ppdesc) {
 503                 return NT_STATUS_NO_MEMORY;
 504         }
 505         return NT_STATUS_OK;
 506 }
 507
 508 static NTSTATUS make_default_acl_windows(TALLOC_CTX *ctx,
 509                                          const char *name,
 510                                          SMB_STRUCT_STAT *psbuf,
 511                                          struct security_descriptor **ppdesc)
 512 {
 513         struct dom_sid owner_sid, group_sid;
 514         size_t size = 0;
 515         struct security_ace aces[4];
 516         uint32_t access_mask = 0;
 517         mode_t mode = psbuf->st_ex_mode;
 518         struct security_acl *new_dacl = NULL;
 519         int idx = 0;
 520
 521         DBG_DEBUG("file [%s] mode [0%o]\n", name, (int)mode);
 522
 523         uid_to_sid(&owner_sid, psbuf->st_ex_uid);
 524         gid_to_sid(&group_sid, psbuf->st_ex_gid);
 525
 526         /*
 527          * We provide 2 ACEs:
 528          * - Owner
 529          * - NT System
 530          */
 531
 532         if (mode & S_IRUSR) {
 533                 if (mode & S_IWUSR) {
 534                         access_mask |= SEC_RIGHTS_FILE_ALL;
 535                 } else {
 536                         access_mask |= SEC_RIGHTS_FILE_READ | SEC_FILE_EXECUTE;
 537                 }
 538         }
 539         if (mode & S_IWUSR) {
 540                 access_mask |= SEC_RIGHTS_FILE_WRITE | SEC_STD_DELETE;
 541         }
 542
 543         init_sec_ace(&aces[idx],
 544                      &owner_sid,
 545                      SEC_ACE_TYPE_ACCESS_ALLOWED,
 546                      access_mask,
 547                      0);
 548         idx++;
 549
 550         init_sec_ace(&aces[idx],
 551                      &global_sid_System,
 552                      SEC_ACE_TYPE_ACCESS_ALLOWED,
 553                      SEC_RIGHTS_FILE_ALL,
 554                      0);
 555         idx++;
 556
 557         new_dacl = make_sec_acl(ctx,
 558                                 NT4_ACL_REVISION,
 559                                 idx,
 560                                 aces);
 561
 562         if (!new_dacl) {
 563                 return NT_STATUS_NO_MEMORY;
 564         }
 565
 566         *ppdesc = make_sec_desc(ctx,
 567                                 SECURITY_DESCRIPTOR_REVISION_1,
 568                                 SEC_DESC_SELF_RELATIVE|SEC_DESC_DACL_PRESENT,
 569                                 &owner_sid,
 570                                 &group_sid,
 571                                 NULL,
 572                                 new_dacl,
 573                                 &size);
 574         if (!*ppdesc) {
 575                 return NT_STATUS_NO_MEMORY;
 576         }
 577         return NT_STATUS_OK;
 578 }
 579
 580 static NTSTATUS make_default_filesystem_acl(TALLOC_CTX *ctx,
 581                                             struct acl_common_config *config,
 582                                             const char *name,
 583                                             SMB_STRUCT_STAT *psbuf,
 584                                             struct security_descriptor **ppdesc)
 585 {
 586         NTSTATUS status;
 587
 588         switch (config->default_acl_style) {
 589
 590         case DEFAULT_ACL_POSIX:
 591                 status =  make_default_acl_posix(ctx, name, psbuf, ppdesc);
 592                 break;
 593
 594         case DEFAULT_ACL_WINDOWS:
 595                 status =  make_default_acl_windows(ctx, name, psbuf, ppdesc);
 596                 break;
 597
 598         default:
 599                 DBG_ERR("unknown acl style %d", config->default_acl_style);
 600                 status = NT_STATUS_INTERNAL_ERROR;
 601                 break;
 602         }
 603
 604         return status;
 605 }
 606
 607 /**
 608  * Validate an ACL blob
 609  *
 610  * This validates an ACL blob against the underlying filesystem ACL. If this
 611  * function returns NT_STATUS_OK ppsd can be
 612  *
 613  * 1. the ACL from the blob (psd_from_fs=false), or
 614  * 2. the ACL from the fs (psd_from_fs=true), or
 615  * 3. NULL (!)
 616  *
 617  * If the return value is anything else then NT_STATUS_OK, ppsd is set to NULL
 618  * and psd_from_fs set to false.
 619  *
 620  * Returning the underlying filesystem ACL in case no. 2 is really just an
 621  * optimisation, because some validations have to fetch the filesytem ACL as
 622  * part of the validation, so we already have it available and callers might
 623  * need it as well.
 624  **/
 625 static NTSTATUS validate_nt_acl_blob(TALLOC_CTX *mem_ctx,
 626                                      vfs_handle_struct *handle,
 627                                      files_struct *fsp,
 628                                      const struct smb_filename *smb_fname,
 629                                      const DATA_BLOB *blob,
 630                                      struct security_descriptor **ppsd,
 631                                      bool *psd_is_from_fs)
 632 {
 633         NTSTATUS status;
 634         uint16_t hash_type = XATTR_SD_HASH_TYPE_NONE;
 635         uint16_t xattr_version = 0;
 636         uint8_t hash[XATTR_SD_HASH_SIZE];
 637         uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE];
 638         uint8_t hash_tmp[XATTR_SD_HASH_SIZE];
 639         uint8_t sys_acl_hash_tmp[XATTR_SD_HASH_SIZE];
 640         struct security_descriptor *psd = NULL;
 641         struct security_descriptor *psd_blob = NULL;
 642         struct security_descriptor *psd_fs = NULL;
 643         char *sys_acl_blob_description = NULL;
 644         DATA_BLOB sys_acl_blob = { 0 };
 645         struct acl_common_config *config = NULL;
 646
 647         *ppsd = NULL;
 648         *psd_is_from_fs = false;
 649
 650         SMB_VFS_HANDLE_GET_DATA(handle, config,
 651                                 struct acl_common_config,
 652                                 return NT_STATUS_UNSUCCESSFUL);
 653
 654         status = parse_acl_blob(blob,
 655                                 mem_ctx,
 656                                 &psd_blob,
 657                                 &hash_type,
 658                                 &xattr_version,
 659                                 &hash[0],
 660                                 &sys_acl_hash[0]);
 661         if (!NT_STATUS_IS_OK(status)) {
 662                 DBG_DEBUG("parse_acl_blob returned %s\n", nt_errstr(status));
 663                 goto fail;
 664         }
 665
 666         /* determine which type of xattr we got */
 667         switch (xattr_version) {
 668         case 1:
 669         case 2:
 670                 /* These xattr types are unilatteral, they do not
 671                  * require confirmation of the hash.  In particular,
 672                  * the NTVFS file server uses version 1, but
 673                  * 'samba-tool ntacl' can set these as well */
 674                 *ppsd = psd_blob;
 675                 return NT_STATUS_OK;
 676         case 3:
 677         case 4:
 678                 if (config->ignore_system_acls) {
 679                         *ppsd = psd_blob;
 680                         return NT_STATUS_OK;
 681                 }
 682
 683                 break;
 684         default:
 685                 DBG_DEBUG("ACL blob revision mismatch (%u) for file %s\n",
 686                           (unsigned int)hash_type, smb_fname->base_name);
 687                 TALLOC_FREE(psd_blob);
 688                 return NT_STATUS_OK;
 689         }
 690
 691         /* determine which type of xattr we got */
 692         if (hash_type != XATTR_SD_HASH_TYPE_SHA256) {
 693                 DBG_DEBUG("ACL blob hash type (%u) unexpected for file %s\n",
 694                           (unsigned int)hash_type, smb_fname->base_name);
 695                 TALLOC_FREE(psd_blob);
 696                 return NT_STATUS_OK;
 697         }
 698
 699         /* determine which type of xattr we got */
 700         switch (xattr_version) {
 701         case 4:
 702         {
 703                 int ret;
 704                 if (fsp) {
 705                         /* Get the full underlying sd, then hash. */
 706                         ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FD(handle,
 707                                                                fsp,
 708                                                                mem_ctx,
 709                                                                &sys_acl_blob_description,
 710                                                                &sys_acl_blob);
 711                 } else {
 712                         /* Get the full underlying sd, then hash. */
 713                         ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FILE(handle,
 714                                                  smb_fname,
 715                                                  mem_ctx,
 716                                                  &sys_acl_blob_description,
 717                                                  &sys_acl_blob);
 718                 }
 719
 720                 /* If we fail to get the ACL blob (for some reason) then this
 721                  * is not fatal, we just work based on the NT ACL only */
 722                 if (ret == 0) {
 723                         status = hash_blob_sha256(sys_acl_blob, sys_acl_hash_tmp);
 724                         if (!NT_STATUS_IS_OK(status)) {
 725                                 goto fail;
 726                         }
 727
 728                         TALLOC_FREE(sys_acl_blob_description);
 729                         TALLOC_FREE(sys_acl_blob.data);
 730
 731                         if (memcmp(&sys_acl_hash[0], &sys_acl_hash_tmp[0],
 732                                    XATTR_SD_HASH_SIZE) == 0) {
 733                                 /* Hash matches, return blob sd. */
 734                                 DBG_DEBUG("blob hash matches for file %s\n",
 735                                           smb_fname->base_name);
 736                                 *ppsd = psd_blob;
 737                                 return NT_STATUS_OK;
 738                         }
 739                 }
 740
 741                 /* Otherwise, fall though and see if the NT ACL hash matches */
 742         }
 743         case 3:
 744                 /* Get the full underlying sd for the hash
 745                    or to return as backup. */
 746                 if (fsp) {
 747                         status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
 748                                                           fsp,
 749                                                           HASH_SECURITY_INFO,
 750                                                           mem_ctx,
 751                                                           &psd_fs);
 752                 } else {
 753                         status = SMB_VFS_NEXT_GET_NT_ACL(handle,
 754                                                          smb_fname,
 755                                                          HASH_SECURITY_INFO,
 756                                                          mem_ctx,
 757                                                          &psd_fs);
 758                 }
 759
 760                 if (!NT_STATUS_IS_OK(status)) {
 761                         DBG_DEBUG("get_next_acl for file %s returned %s\n",
 762                                   smb_fname->base_name, nt_errstr(status));
 763                         goto fail;
 764                 }
 765
 766                 status = hash_sd_sha256(psd_fs, hash_tmp);
 767                 if (!NT_STATUS_IS_OK(status)) {
 768                         TALLOC_FREE(psd_blob);
 769                         *ppsd = psd_fs;
 770                         *psd_is_from_fs = true;
 771                         return NT_STATUS_OK;
 772                 }
 773
 774                 if (memcmp(&hash[0], &hash_tmp[0], XATTR_SD_HASH_SIZE) == 0) {
 775                         /* Hash matches, return blob sd. */
 776                         DBG_DEBUG("blob hash matches for file %s\n",
 777                                   smb_fname->base_name);
 778                         *ppsd = psd_blob;
 779                         return NT_STATUS_OK;
 780                 }
 781
 782                 /* Hash doesn't match, return underlying sd. */
 783                 DBG_DEBUG("blob hash does not match for file %s - returning "
 784                           "file system SD mapping.\n",
 785                           smb_fname->base_name);
 786
 787                 if (DEBUGLEVEL >= 10) {
 788                         DBG_DEBUG("acl for blob hash for %s is:\n",
 789                                   smb_fname->base_name);
 790                         NDR_PRINT_DEBUG(security_descriptor, psd_fs);
 791                 }
 792
 793                 TALLOC_FREE(psd_blob);
 794                 *ppsd = psd_fs;
 795                 *psd_is_from_fs = true;
 796         }
 797
 798         return NT_STATUS_OK;
 799
 800 fail:
 801         TALLOC_FREE(psd);
 802         TALLOC_FREE(psd_blob);
 803         TALLOC_FREE(psd_fs);
 804         TALLOC_FREE(sys_acl_blob_description);
 805         TALLOC_FREE(sys_acl_blob.data);
 806         return status;
 807 }
 808
 809 static NTSTATUS stat_fsp_or_smb_fname(vfs_handle_struct *handle,
 810                                       files_struct *fsp,
 811                                       const struct smb_filename *smb_fname,
 812                                       SMB_STRUCT_STAT *sbuf,
 813                                       SMB_STRUCT_STAT **psbuf)
 814 {
 815         NTSTATUS status;
 816         int ret;
 817
 818         if (fsp) {
 819                 status = vfs_stat_fsp(fsp);
 820                 if (!NT_STATUS_IS_OK(status)) {
 821                         return status;
 822                 }
 823                 *psbuf = &fsp->fsp_name->st;
 824         } else {
 825                 /*
 826                  * https://bugzilla.samba.org/show_bug.cgi?id=11249
 827                  *
 828                  * We are currently guaranteed that 'name' here is a
 829                  * smb_fname->base_name, which *cannot* contain a stream name
 830                  * (':'). vfs_stat_smb_fname() splits a name into a base name +
 831                  * stream name, which when we get here we know we've already
 832                  * done.  So we have to call the stat or lstat VFS calls
 833                  * directly here. Else, a base_name that contains a ':' (from a
 834                  * demangled name) will get split again.
 835                  *
 836                  * FIXME.
 837                  * This uglyness will go away once smb_fname is fully plumbed
 838                  * through the VFS.
 839                  */
 840                 ret = vfs_stat_smb_basename(handle->conn,
 841                                             smb_fname,
 842                                             sbuf);
 843                 if (ret == -1) {
 844                         return map_nt_error_from_unix(errno);
 845                 }
 846         }
 847
 848         return NT_STATUS_OK;
 849 }
 850
 851 /*******************************************************************
 852  Pull a DATA_BLOB from an xattr given a pathname.
 853  If the hash doesn't match, or doesn't exist - return the underlying
 854  filesystem sd.
 855 *******************************************************************/
 856
 857 static NTSTATUS get_nt_acl_internal(
 858         NTSTATUS (*get_acl_blob_fn)(TALLOC_CTX *ctx,
 859                                     vfs_handle_struct *handle,
 860                                     files_struct *fsp,
 861                                     const struct smb_filename *smb_fname,
 862                                     DATA_BLOB *pblob),
 863         vfs_handle_struct *handle,
 864         files_struct *fsp,
 865         const struct smb_filename *smb_fname_in,
 866         uint32_t security_info,
 867         TALLOC_CTX *mem_ctx,
 868         struct security_descriptor **ppdesc)
 869 {
 870         DATA_BLOB blob = data_blob_null;
 871         NTSTATUS status;
 872         struct security_descriptor *psd = NULL;
 873         const struct smb_filename *smb_fname = NULL;
 874         bool psd_is_from_fs = false;
 875         struct acl_common_config *config = NULL;
 876
 877         SMB_VFS_HANDLE_GET_DATA(handle, config,
 878                                 struct acl_common_config,
 879                                 return NT_STATUS_UNSUCCESSFUL);
 880
 881         if (fsp && smb_fname_in == NULL) {
 882                 smb_fname = fsp->fsp_name;
 883         } else {
 884                 smb_fname = smb_fname_in;
 885         }
 886
 887         DBG_DEBUG("name=%s\n", smb_fname->base_name);
 888
 889         status = get_acl_blob_fn(mem_ctx, handle, fsp, smb_fname, &blob);
 890         if (NT_STATUS_IS_OK(status)) {
 891                 status = validate_nt_acl_blob(mem_ctx,
 892                                               handle,
 893                                               fsp,
 894                                               smb_fname,
 895                                               &blob,
 896                                               &psd,
 897                                               &psd_is_from_fs);
 898                 TALLOC_FREE(blob.data);
 899                 if (!NT_STATUS_IS_OK(status)) {
 900                         DBG_DEBUG("ACL validation for [%s] failed\n",
 901                                   smb_fname->base_name);
 902                         goto fail;
 903                 }
 904         }
 905
 906         if (psd == NULL) {
 907                 /* Get the full underlying sd, as we failed to get the
 908                  * blob for the hash, or the revision/hash type wasn't
 909                  * known */
 910
 911                 if (config->ignore_system_acls) {
 912                         SMB_STRUCT_STAT sbuf;
 913                         SMB_STRUCT_STAT *psbuf = &sbuf;
 914
 915                         status = stat_fsp_or_smb_fname(handle, fsp, smb_fname,
 916                                                        &sbuf, &psbuf);
 917                         if (!NT_STATUS_IS_OK(status)) {
 918                                 goto fail;
 919                         }
 920
 921                         status = make_default_filesystem_acl(
 922                                 mem_ctx,
 923                                 config,
 924                                 smb_fname->base_name,
 925                                 psbuf,
 926                                 &psd);
 927                         if (!NT_STATUS_IS_OK(status)) {
 928                                 goto fail;
 929                         }
 930                 } else {
 931                         if (fsp) {
 932                                 status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
 933                                                                   fsp,
 934                                                                   security_info,
 935                                                                   mem_ctx,
 936                                                                   &psd);
 937                         } else {
 938                                 status = SMB_VFS_NEXT_GET_NT_ACL(handle,
 939                                                                  smb_fname,
 940                                                                  security_info,
 941                                                                  mem_ctx,
 942                                                                  &psd);
 943                         }
 944
 945                         if (!NT_STATUS_IS_OK(status)) {
 946                                 DBG_DEBUG("get_next_acl for file %s "
 947                                           "returned %s\n",
 948                                           smb_fname->base_name,
 949                                           nt_errstr(status));
 950                                 goto fail;
 951                         }
 952
 953                         psd_is_from_fs = true;
 954                 }
 955         }
 956
 957         if (psd_is_from_fs) {
 958                 SMB_STRUCT_STAT sbuf;
 959                 SMB_STRUCT_STAT *psbuf = &sbuf;
 960                 bool is_directory = false;
 961
 962                 /*
 963                  * We're returning the underlying ACL from the
 964                  * filesystem. If it's a directory, and has no
 965                  * inheritable ACE entries we have to fake them.
 966                  */
 967
 968                 status = stat_fsp_or_smb_fname(handle, fsp, smb_fname,
 969                                                &sbuf, &psbuf);
 970                 if (!NT_STATUS_IS_OK(status)) {
 971                         goto fail;
 972                 }
 973
 974                 is_directory = S_ISDIR(psbuf->st_ex_mode);
 975
 976                 if (is_directory && !sd_has_inheritable_components(psd, true)) {
 977                         status = add_directory_inheritable_components(
 978                                 handle,
 979                                 smb_fname->base_name,
 980                                 psbuf,
 981                                 psd);
 982                         if (!NT_STATUS_IS_OK(status)) {
 983                                 goto fail;
 984                         }
 985                 }
 986
 987                 /*
 988                  * The underlying POSIX module always sets the
 989                  * ~SEC_DESC_DACL_PROTECTED bit, as ACLs can't be inherited in
 990                  * this way under POSIX. Remove it for Windows-style ACLs.
 991                  */
 992                 psd->type &= ~SEC_DESC_DACL_PROTECTED;
 993         }
 994
 995         if (!(security_info & SECINFO_OWNER)) {
 996                 psd->owner_sid = NULL;
 997         }
 998         if (!(security_info & SECINFO_GROUP)) {
 999                 psd->group_sid = NULL;
1000         }
1001         if (!(security_info & SECINFO_DACL)) {
1002                 psd->type &= ~SEC_DESC_DACL_PRESENT;
1003                 psd->dacl = NULL;
1004         }
1005         if (!(security_info & SECINFO_SACL)) {
1006                 psd->type &= ~SEC_DESC_SACL_PRESENT;
1007                 psd->sacl = NULL;
1008         }
1009
1010         if (DEBUGLEVEL >= 10) {
1011                 DBG_DEBUG("returning acl for %s is:\n",
1012                           smb_fname->base_name);
1013                 NDR_PRINT_DEBUG(security_descriptor, psd);
1014         }
1015
1016         *ppdesc = psd;
1017
1018         return NT_STATUS_OK;
1019
1020 fail:
1021         TALLOC_FREE(psd);
1022         return status;
1023 }
1024
1025 /*********************************************************************
1026  Fetch a security descriptor given an fsp.
1027 *********************************************************************/
1028
1029 static NTSTATUS fget_nt_acl_common(vfs_handle_struct *handle,
1030                                    files_struct *fsp,
1031                                    uint32_t security_info,
1032                                    TALLOC_CTX *mem_ctx,
1033                                    struct security_descriptor **ppdesc)
1034 {
1035         return get_nt_acl_internal(get_acl_blob, handle, fsp, NULL,
1036                                    security_info, mem_ctx, ppdesc);
1037 }
1038
1039 /*********************************************************************
1040  Fetch a security descriptor given a pathname.
1041 *********************************************************************/
1042
1043 static NTSTATUS get_nt_acl_common(vfs_handle_struct *handle,
1044                                   const struct smb_filename *smb_fname,
1045                                   uint32_t security_info,
1046                                   TALLOC_CTX *mem_ctx,
1047                                   struct security_descriptor **ppdesc)
1048 {
1049         return get_nt_acl_internal(get_acl_blob, handle, NULL, smb_fname,
1050                                    security_info, mem_ctx, ppdesc);
1051 }
1052
1053 /*********************************************************************
1054  Set the underlying ACL (e.g. POSIX ACLS, POSIX owner, etc)
1055 *********************************************************************/
1056 static NTSTATUS set_underlying_acl(vfs_handle_struct *handle, files_struct *fsp,
1057                                    struct security_descriptor *psd,
1058                                    uint32_t security_info_sent,
1059                                    bool chown_needed)
1060 {
1061         NTSTATUS status =
1062             SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp, security_info_sent, psd);
1063         if (!NT_STATUS_EQUAL(status, NT_STATUS_ACCESS_DENIED)) {
1064                 return status;
1065         }
1066
1067         /* We got access denied here. If we're already root,
1068            or we didn't need to do a chown, or the fsp isn't
1069            open with WRITE_OWNER access, just return. */
1070         if (get_current_uid(handle->conn) == 0 || chown_needed == false ||
1071             !(fsp->access_mask & SEC_STD_WRITE_OWNER)) {
1072                 return NT_STATUS_ACCESS_DENIED;
1073         }
1074
1075         DBG_DEBUG("overriding chown on file %s for sid %s\n",
1076                    fsp_str_dbg(fsp), sid_string_tos(psd->owner_sid));
1077
1078         /* Ok, we failed to chown and we have
1079            SEC_STD_WRITE_OWNER access - override. */
1080         become_root();
1081         status = SMB_VFS_NEXT_FSET_NT_ACL(handle, fsp, security_info_sent, psd);
1082         unbecome_root();
1083
1084         return status;
1085 }
1086
1087 /*********************************************************************
1088  Store a v3 security descriptor
1089 *********************************************************************/
1090 static NTSTATUS store_v3_blob(vfs_handle_struct *handle, files_struct *fsp,
1091                               struct security_descriptor *psd,
1092                               struct security_descriptor *pdesc_next,
1093                               uint8_t hash[XATTR_SD_HASH_SIZE])
1094 {
1095         NTSTATUS status;
1096         DATA_BLOB blob;
1097
1098         if (DEBUGLEVEL >= 10) {
1099                 DBG_DEBUG("storing xattr sd for file %s\n",
1100                           fsp_str_dbg(fsp));
1101                 NDR_PRINT_DEBUG(
1102                     security_descriptor,
1103                     discard_const_p(struct security_descriptor, psd));
1104
1105                 if (pdesc_next != NULL) {
1106                         DBG_DEBUG("storing xattr sd based on \n");
1107                         NDR_PRINT_DEBUG(
1108                             security_descriptor,
1109                             discard_const_p(struct security_descriptor,
1110                                             pdesc_next));
1111                 } else {
1112                         DBG_DEBUG("ignoring underlying sd\n");
1113                 }
1114         }
1115         status = create_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash);
1116         if (!NT_STATUS_IS_OK(status)) {
1117                 DBG_DEBUG("create_acl_blob failed\n");
1118                 return status;
1119         }
1120
1121         status = store_acl_blob_fsp(handle, fsp, &blob);
1122         return status;
1123 }
1124
1125 /*********************************************************************
1126  Store a security descriptor given an fsp.
1127 *********************************************************************/
1128
1129 static NTSTATUS fset_nt_acl_common(vfs_handle_struct *handle, files_struct *fsp,
1130         uint32_t security_info_sent, const struct security_descriptor *orig_psd)
1131 {
1132         NTSTATUS status;
1133         int ret;
1134         DATA_BLOB blob, sys_acl_blob;
1135         struct security_descriptor *pdesc_next = NULL;
1136         struct security_descriptor *psd = NULL;
1137         uint8_t hash[XATTR_SD_HASH_SIZE];
1138         uint8_t sys_acl_hash[XATTR_SD_HASH_SIZE];
1139         bool chown_needed = false;
1140         char *sys_acl_description;
1141         TALLOC_CTX *frame = talloc_stackframe();
1142         bool ignore_file_system_acl = lp_parm_bool(
1143             SNUM(handle->conn), ACL_MODULE_NAME, "ignore system acls", false);
1144
1145         if (DEBUGLEVEL >= 10) {
1146                 DBG_DEBUG("incoming sd for file %s\n", fsp_str_dbg(fsp));
1147                 NDR_PRINT_DEBUG(security_descriptor,
1148                         discard_const_p(struct security_descriptor, orig_psd));
1149         }
1150
1151         status = get_nt_acl_internal(get_acl_blob, handle, fsp,
1152                         NULL,
1153                         SECINFO_OWNER|SECINFO_GROUP|SECINFO_DACL|SECINFO_SACL,
1154                                      frame,
1155                         &psd);
1156
1157         if (!NT_STATUS_IS_OK(status)) {
1158                 TALLOC_FREE(frame);
1159                 return status;
1160         }
1161
1162         psd->revision = orig_psd->revision;
1163         /* All our SD's are self relative. */
1164         psd->type = orig_psd->type | SEC_DESC_SELF_RELATIVE;
1165
1166         if ((security_info_sent & SECINFO_OWNER) && (orig_psd->owner_sid != NULL)) {
1167                 if (!dom_sid_equal(orig_psd->owner_sid, psd->owner_sid)) {
1168                         /* We're changing the owner. */
1169                         chown_needed = true;
1170                 }
1171                 psd->owner_sid = orig_psd->owner_sid;
1172         }
1173         if ((security_info_sent & SECINFO_GROUP) && (orig_psd->group_sid != NULL)) {
1174                 if (!dom_sid_equal(orig_psd->group_sid, psd->group_sid)) {
1175                         /* We're changing the group. */
1176                         chown_needed = true;
1177                 }
1178                 psd->group_sid = orig_psd->group_sid;
1179         }
1180         if (security_info_sent & SECINFO_DACL) {
1181                 if (security_descriptor_with_ms_nfs(orig_psd)) {
1182                         /*
1183                          * If the sd contains a MS NFS SID, do
1184                          * nothing, it's a chmod() request from OS X
1185                          * with AAPL context.
1186                          */
1187                         TALLOC_FREE(frame);
1188                         return NT_STATUS_OK;
1189                 }
1190                 psd->dacl = orig_psd->dacl;
1191                 psd->type |= SEC_DESC_DACL_PRESENT;
1192         }
1193         if (security_info_sent & SECINFO_SACL) {
1194                 psd->sacl = orig_psd->sacl;
1195                 psd->type |= SEC_DESC_SACL_PRESENT;
1196         }
1197
1198         if (ignore_file_system_acl) {
1199                 if (chown_needed) {
1200                         /* send only ownership stuff to lower layer */
1201                         security_info_sent &= (SECINFO_OWNER | SECINFO_GROUP);
1202                         status = set_underlying_acl(handle, fsp, psd,
1203                                                     security_info_sent, true);
1204                         if (!NT_STATUS_IS_OK(status)) {
1205                                 TALLOC_FREE(frame);
1206                                 return status;
1207                         }
1208                 }
1209                 ZERO_ARRAY(hash);
1210                 status = store_v3_blob(handle, fsp, psd, NULL, hash);
1211
1212                 TALLOC_FREE(frame);
1213                 return status;
1214         }
1215
1216         status = set_underlying_acl(handle, fsp, psd, security_info_sent,
1217                                     chown_needed);
1218         if (!NT_STATUS_IS_OK(status)) {
1219                 TALLOC_FREE(frame);
1220                 return status;
1221         }
1222
1223         /* Get the full underlying sd, then hash. */
1224         status = SMB_VFS_NEXT_FGET_NT_ACL(handle,
1225                                           fsp,
1226                                           HASH_SECURITY_INFO,
1227                                           frame,
1228                                           &pdesc_next);
1229
1230         if (!NT_STATUS_IS_OK(status)) {
1231                 TALLOC_FREE(frame);
1232                 return status;
1233         }
1234
1235         status = hash_sd_sha256(pdesc_next, hash);
1236         if (!NT_STATUS_IS_OK(status)) {
1237                 TALLOC_FREE(frame);
1238                 return status;
1239         }
1240
1241         /* Get the full underlying sd, then hash. */
1242         ret = SMB_VFS_NEXT_SYS_ACL_BLOB_GET_FD(handle,
1243                                                fsp,
1244                                                frame,
1245                                                &sys_acl_description,
1246                                                &sys_acl_blob);
1247
1248         /* If we fail to get the ACL blob (for some reason) then this
1249          * is not fatal, we just work based on the NT ACL only */
1250         if (ret != 0) {
1251                 status = store_v3_blob(handle, fsp, psd, pdesc_next, hash);
1252
1253                 TALLOC_FREE(frame);
1254                 return status;
1255         }
1256
1257         status = hash_blob_sha256(sys_acl_blob, sys_acl_hash);
1258         if (!NT_STATUS_IS_OK(status)) {
1259                 TALLOC_FREE(frame);
1260                 return status;
1261         }
1262
1263         if (DEBUGLEVEL >= 10) {
1264                 DBG_DEBUG("storing xattr sd for file %s based on system ACL\n",
1265                           fsp_str_dbg(fsp));
1266                 NDR_PRINT_DEBUG(security_descriptor,
1267                                 discard_const_p(struct security_descriptor, psd));
1268
1269                 DBG_DEBUG("storing hash in xattr sd based on system ACL and:\n");
1270                 NDR_PRINT_DEBUG(security_descriptor,
1271                                 discard_const_p(struct security_descriptor, pdesc_next));
1272         }
1273
1274         /* We store hashes of both the sys ACL blob and the NT
1275          * security desciptor mapped from that ACL so as to improve
1276          * our chances against some inadvertant change breaking the
1277          * hash used */
1278         status = create_sys_acl_blob(psd, &blob, XATTR_SD_HASH_TYPE_SHA256, hash,
1279                                      sys_acl_description, sys_acl_hash);
1280         if (!NT_STATUS_IS_OK(status)) {
1281                 DBG_DEBUG("create_sys_acl_blob failed\n");
1282                 TALLOC_FREE(frame);
1283                 return status;
1284         }
1285
1286         status = store_acl_blob_fsp(handle, fsp, &blob);
1287
1288         TALLOC_FREE(frame);
1289         return status;
1290 }
1291
1292 static int acl_common_remove_object(vfs_handle_struct *handle,
1293                                         const struct smb_filename *smb_fname,
1294                                         bool is_directory)
1295 {
1296         connection_struct *conn = handle->conn;
1297         struct file_id id;
1298         files_struct *fsp = NULL;
1299         int ret = 0;
1300         char *parent_dir = NULL;
1301         const char *final_component = NULL;
1302         struct smb_filename local_fname = {0};
1303         struct smb_filename parent_dir_fname = {0};
1304         int saved_errno = 0;
1305         struct smb_filename *saved_dir_fname = NULL;
1306
1307         saved_dir_fname = vfs_GetWd(talloc_tos(),conn);
1308         if (saved_dir_fname == NULL) {
1309                 saved_errno = errno;
1310                 goto out;
1311         }
1312
1313         if (!parent_dirname(talloc_tos(), smb_fname->base_name,
1314                         &parent_dir, &final_component)) {
1315                 saved_errno = ENOMEM;
1316                 goto out;
1317         }
1318
1319         DBG_DEBUG("removing %s %s/%s\n", is_directory ? "directory" : "file",
1320                   parent_dir, final_component);
1321
1322         parent_dir_fname = (struct smb_filename) { .base_name = parent_dir };
1323
1324         /* cd into the parent dir to pin it. */
1325         ret = vfs_ChDir(conn, &parent_dir_fname);
1326         if (ret == -1) {
1327                 saved_errno = errno;
1328                 goto out;
1329         }
1330
1331         local_fname.base_name = discard_const_p(char, final_component);
1332
1333         /* Must use lstat here. */
1334         ret = SMB_VFS_LSTAT(conn, &local_fname);
1335         if (ret == -1) {
1336                 saved_errno = errno;
1337                 goto out;
1338         }
1339
1340         /* Ensure we have this file open with DELETE access. */
1341         id = vfs_file_id_from_sbuf(conn, &local_fname.st);
1342         for (fsp = file_find_di_first(conn->sconn, id); fsp;
1343                      fsp = file_find_di_next(fsp)) {
1344                 if (fsp->access_mask & DELETE_ACCESS &&
1345                                 fsp->delete_on_close) {
1346                         /* We did open this for delete,
1347                          * allow the delete as root.
1348                          */
1349                         break;
1350                 }
1351         }
1352
1353         if (!fsp) {
1354                 DBG_DEBUG("%s %s/%s not an open file\n",
1355                           is_directory ? "directory" : "file",
1356                           parent_dir, final_component);
1357                 saved_errno = EACCES;
1358                 goto out;
1359         }
1360
1361         become_root();
1362         if (is_directory) {
1363                 ret = SMB_VFS_NEXT_RMDIR(handle, &local_fname);
1364         } else {
1365                 ret = SMB_VFS_NEXT_UNLINK(handle, &local_fname);
1366         }
1367         unbecome_root();
1368
1369         if (ret == -1) {
1370                 saved_errno = errno;
1371         }
1372
1373   out:
1374
1375         TALLOC_FREE(parent_dir);
1376
1377         if (saved_dir_fname) {
1378                 vfs_ChDir(conn, saved_dir_fname);
1379                 TALLOC_FREE(saved_dir_fname);
1380         }
1381         if (saved_errno) {
1382                 errno = saved_errno;
1383         }
1384         return ret;
1385 }
1386
1387 static int rmdir_acl_common(struct vfs_handle_struct *handle,
1388                                 const struct smb_filename *smb_fname)
1389 {
1390         int ret;
1391
1392         /* Try the normal rmdir first. */
1393         ret = SMB_VFS_NEXT_RMDIR(handle, smb_fname);
1394         if (ret == 0) {
1395                 return 0;
1396         }
1397         if (errno == EACCES || errno == EPERM) {
1398                 /* Failed due to access denied,
1399                    see if we need to root override. */
1400                 return acl_common_remove_object(handle,
1401                                                 smb_fname,
1402                                                 true);
1403         }
1404
1405         DBG_DEBUG("unlink of %s failed %s\n",
1406                   smb_fname->base_name,
1407                   strerror(errno));
1408         return -1;
1409 }
1410
1411 static int unlink_acl_common(struct vfs_handle_struct *handle,
1412                         const struct smb_filename *smb_fname)
1413 {
1414         int ret;
1415
1416         /* Try the normal unlink first. */
1417         ret = SMB_VFS_NEXT_UNLINK(handle, smb_fname);
1418         if (ret == 0) {
1419                 return 0;
1420         }
1421         if (errno == EACCES || errno == EPERM) {
1422                 /* Failed due to access denied,
1423                    see if we need to root override. */
1424
1425                 /* Don't do anything fancy for streams. */
1426                 if (smb_fname->stream_name) {
1427                         return -1;
1428                 }
1429                 return acl_common_remove_object(handle,
1430                                         smb_fname,
1431                                         false);
1432         }
1433
1434         DBG_DEBUG("unlink of %s failed %s\n",
1435                   smb_fname->base_name,
1436                   strerror(errno));
1437         return -1;
1438 }
1439
1440 static int chmod_acl_module_common(struct vfs_handle_struct *handle,
1441                         const struct smb_filename *smb_fname,
1442                         mode_t mode)
1443 {
1444         if (smb_fname->flags & SMB_FILENAME_POSIX_PATH) {
1445                 /* Only allow this on POSIX pathnames. */
1446                 return SMB_VFS_NEXT_CHMOD(handle, smb_fname, mode);
1447         }
1448         return 0;
1449 }
1450
1451 static int fchmod_acl_module_common(struct vfs_handle_struct *handle,
1452                         struct files_struct *fsp, mode_t mode)
1453 {
1454         if (fsp->posix_flags & FSP_POSIX_FLAGS_OPEN) {
1455                 /* Only allow this on POSIX opens. */
1456                 return SMB_VFS_NEXT_FCHMOD(handle, fsp, mode);
1457         }
1458         return 0;
1459 }
1460
1461 static int chmod_acl_acl_module_common(struct vfs_handle_struct *handle,
1462                         const struct smb_filename *smb_fname,
1463                         mode_t mode)
1464 {
1465         if (smb_fname->flags & SMB_FILENAME_POSIX_PATH) {
1466                 /* Only allow this on POSIX pathnames. */
1467                 return SMB_VFS_NEXT_CHMOD_ACL(handle, smb_fname, mode);
1468         }
1469         return 0;
1470 }
1471
1472 static int fchmod_acl_acl_module_common(struct vfs_handle_struct *handle,
1473                         struct files_struct *fsp, mode_t mode)
1474 {
1475         if (fsp->posix_flags & FSP_POSIX_FLAGS_OPEN) {
1476                 /* Only allow this on POSIX opens. */
1477                 return SMB_VFS_NEXT_FCHMOD_ACL(handle, fsp, mode);
1478         }
1479         return 0;
1480 }