source3/modules/vfs_xattr_tdb.c

   1 /*
   2  * Store posix-level xattrs in a tdb
   3  *
   4  * Copyright (C) Volker Lendecke, 2007
   5  * Copyright (C) Andrew Bartlett, 2012
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 3 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include "includes.h"
  22 #include "system/filesys.h"
  23 #include "smbd/smbd.h"
  24 #include "dbwrap/dbwrap.h"
  25 #include "dbwrap/dbwrap_open.h"
  26 #include "source3/lib/xattr_tdb.h"
  27
  28 #undef DBGC_CLASS
  29 #define DBGC_CLASS DBGC_VFS
  30
  31 static bool xattr_tdb_init(int snum, TALLOC_CTX *mem_ctx, struct db_context **p_db);
  32
  33 static int xattr_tdb_get_file_id(struct vfs_handle_struct *handle,
  34                                 const char *path, struct file_id *id)
  35 {
  36         int ret;
  37         TALLOC_CTX *frame = talloc_stackframe();
  38         struct smb_filename *smb_fname;
  39
  40         smb_fname = synthetic_smb_fname(frame, path, NULL, NULL, 0);
  41         if (smb_fname == NULL) {
  42                 TALLOC_FREE(frame);
  43                 errno = ENOMEM;
  44                 return -1;
  45         }
  46
  47         ret = SMB_VFS_NEXT_STAT(handle, smb_fname);
  48
  49         if (ret == -1) {
  50                 TALLOC_FREE(frame);
  51                 return -1;
  52         }
  53
  54         *id = SMB_VFS_NEXT_FILE_ID_CREATE(handle, &smb_fname->st);
  55         TALLOC_FREE(frame);
  56         return 0;
  57 }
  58
  59 static ssize_t xattr_tdb_getxattr(struct vfs_handle_struct *handle,
  60                                 const struct smb_filename *smb_fname,
  61                                 const char *name,
  62                                 void *value,
  63                                 size_t size)
  64 {
  65         struct file_id id;
  66         struct db_context *db;
  67         ssize_t xattr_size;
  68         int ret;
  69         DATA_BLOB blob;
  70         TALLOC_CTX *frame = talloc_stackframe();
  71
  72         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context,
  73                                 if (!xattr_tdb_init(-1, frame, &db))
  74                                 {
  75                                         TALLOC_FREE(frame); return -1;
  76                                 });
  77
  78         ret = xattr_tdb_get_file_id(handle, smb_fname->base_name, &id);
  79         if (ret == -1) {
  80                 TALLOC_FREE(frame);
  81                 return -1;
  82         }
  83
  84         xattr_size = xattr_tdb_getattr(db, frame, &id, name, &blob);
  85         if (xattr_size < 0) {
  86                 errno = ENOATTR;
  87                 TALLOC_FREE(frame);
  88                 return -1;
  89         }
  90
  91         if (size == 0) {
  92                 TALLOC_FREE(frame);
  93                 return xattr_size;
  94         }
  95
  96         if (blob.length > size) {
  97                 TALLOC_FREE(frame);
  98                 errno = ERANGE;
  99                 return -1;
 100         }
 101         memcpy(value, blob.data, xattr_size);
 102         TALLOC_FREE(frame);
 103         return xattr_size;
 104 }
 105
 106 static ssize_t xattr_tdb_fgetxattr(struct vfs_handle_struct *handle,
 107                                    struct files_struct *fsp,
 108                                    const char *name, void *value, size_t size)
 109 {
 110         SMB_STRUCT_STAT sbuf;
 111         struct file_id id;
 112         struct db_context *db;
 113         ssize_t xattr_size;
 114         DATA_BLOB blob;
 115         TALLOC_CTX *frame = talloc_stackframe();
 116
 117         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context,
 118                                 if (!xattr_tdb_init(-1, frame, &db))
 119                                 {
 120                                         TALLOC_FREE(frame); return -1;
 121                                 });
 122
 123         if (SMB_VFS_NEXT_FSTAT(handle, fsp, &sbuf) == -1) {
 124                 TALLOC_FREE(frame);
 125                 return -1;
 126         }
 127
 128         id = SMB_VFS_NEXT_FILE_ID_CREATE(handle, &sbuf);
 129
 130         xattr_size = xattr_tdb_getattr(db, frame, &id, name, &blob);
 131         if (xattr_size < 0) {
 132                 errno = ENOATTR;
 133                 TALLOC_FREE(frame);
 134                 return -1;
 135         }
 136
 137         if (size == 0) {
 138                 TALLOC_FREE(frame);
 139                 return xattr_size;
 140         }
 141
 142         if (blob.length > size) {
 143                 TALLOC_FREE(frame);
 144                 errno = ERANGE;
 145                 return -1;
 146         }
 147         memcpy(value, blob.data, xattr_size);
 148         TALLOC_FREE(frame);
 149         return xattr_size;
 150 }
 151
 152 static int xattr_tdb_setxattr(struct vfs_handle_struct *handle,
 153                                 const struct smb_filename *smb_fname,
 154                                 const char *name,
 155                                 const void *value,
 156                                 size_t size,
 157                                 int flags)
 158 {
 159         struct file_id id;
 160         struct db_context *db;
 161         int ret;
 162         TALLOC_CTX *frame = talloc_stackframe();
 163
 164         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context,
 165                                 if (!xattr_tdb_init(-1, frame, &db))
 166                                 {
 167                                         TALLOC_FREE(frame); return -1;
 168                                 });
 169
 170         ret = xattr_tdb_get_file_id(handle, smb_fname->base_name, &id);
 171         if (ret == -1) {
 172                 TALLOC_FREE(frame);
 173                 return -1;
 174         }
 175
 176         ret = xattr_tdb_setattr(db, &id, name, value, size, flags);
 177         TALLOC_FREE(frame);
 178         return ret;
 179 }
 180
 181 static int xattr_tdb_fsetxattr(struct vfs_handle_struct *handle,
 182                                struct files_struct *fsp,
 183                                const char *name, const void *value,
 184                                size_t size, int flags)
 185 {
 186         SMB_STRUCT_STAT sbuf;
 187         struct file_id id;
 188         struct db_context *db;
 189         int ret;
 190         TALLOC_CTX *frame = talloc_stackframe();
 191
 192         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context,
 193                                 if (!xattr_tdb_init(-1, frame, &db))
 194                                 {
 195                                         TALLOC_FREE(frame); return -1;
 196                                 });
 197
 198         if (SMB_VFS_NEXT_FSTAT(handle, fsp, &sbuf) == -1) {
 199                 TALLOC_FREE(frame);
 200                 return -1;
 201         }
 202
 203         id = SMB_VFS_NEXT_FILE_ID_CREATE(handle, &sbuf);
 204
 205         ret = xattr_tdb_setattr(db, &id, name, value, size, flags);
 206         TALLOC_FREE(frame);
 207         return ret;
 208
 209 }
 210
 211 static ssize_t xattr_tdb_listxattr(struct vfs_handle_struct *handle,
 212                                 const struct smb_filename *smb_fname,
 213                                 char *list,
 214                                 size_t size)
 215 {
 216         struct file_id id;
 217         struct db_context *db;
 218         int ret;
 219         TALLOC_CTX *frame = talloc_stackframe();
 220
 221         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context,
 222                                 if (!xattr_tdb_init(-1, frame, &db))
 223                                 {
 224                                         TALLOC_FREE(frame); return -1;
 225                                 });
 226
 227         ret = xattr_tdb_get_file_id(handle, smb_fname->base_name, &id);
 228         if (ret == -1) {
 229                 TALLOC_FREE(frame);
 230                 return -1;
 231         }
 232
 233         ret = xattr_tdb_listattr(db, &id, list, size);
 234         TALLOC_FREE(frame);
 235         return ret;
 236
 237 }
 238
 239 static ssize_t xattr_tdb_flistxattr(struct vfs_handle_struct *handle,
 240                                     struct files_struct *fsp, char *list,
 241                                     size_t size)
 242 {
 243         SMB_STRUCT_STAT sbuf;
 244         struct file_id id;
 245         struct db_context *db;
 246         int ret;
 247         TALLOC_CTX *frame = talloc_stackframe();
 248
 249         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context,
 250                                 if (!xattr_tdb_init(-1, frame, &db))
 251                                 {
 252                                         TALLOC_FREE(frame); return -1;
 253                                 });
 254
 255         if (SMB_VFS_NEXT_FSTAT(handle, fsp, &sbuf) == -1) {
 256                 TALLOC_FREE(frame);
 257                 return -1;
 258         }
 259
 260         id = SMB_VFS_NEXT_FILE_ID_CREATE(handle, &sbuf);
 261
 262         ret = xattr_tdb_listattr(db, &id, list, size);
 263         TALLOC_FREE(frame);
 264         return ret;
 265 }
 266
 267 static int xattr_tdb_removexattr(struct vfs_handle_struct *handle,
 268                                 const struct smb_filename *smb_fname,
 269                                 const char *name)
 270 {
 271         struct file_id id;
 272         struct db_context *db;
 273         int ret;
 274         TALLOC_CTX *frame = talloc_stackframe();
 275
 276         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context,
 277                                 if (!xattr_tdb_init(-1, frame, &db))
 278                                 {
 279                                         TALLOC_FREE(frame); return -1;
 280                                 });
 281
 282         ret = xattr_tdb_get_file_id(handle, smb_fname->base_name, &id);
 283         if (ret == -1) {
 284                 TALLOC_FREE(frame);
 285                 return ret;
 286         }
 287
 288
 289         ret = xattr_tdb_removeattr(db, &id, name);
 290         TALLOC_FREE(frame);
 291         return ret;
 292 }
 293
 294 static int xattr_tdb_fremovexattr(struct vfs_handle_struct *handle,
 295                                   struct files_struct *fsp, const char *name)
 296 {
 297         SMB_STRUCT_STAT sbuf;
 298         struct file_id id;
 299         struct db_context *db;
 300         int ret;
 301         TALLOC_CTX *frame = talloc_stackframe();
 302
 303         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context,
 304                                 if (!xattr_tdb_init(-1, frame, &db))
 305                                 {
 306                                         TALLOC_FREE(frame); return -1;
 307                                 });
 308
 309         if (SMB_VFS_NEXT_FSTAT(handle, fsp, &sbuf) == -1) {
 310                 TALLOC_FREE(frame);
 311                 return -1;
 312         }
 313
 314         id = SMB_VFS_NEXT_FILE_ID_CREATE(handle, &sbuf);
 315
 316         ret = xattr_tdb_removeattr(db, &id, name);
 317         TALLOC_FREE(frame);
 318         return ret;
 319 }
 320
 321 /*
 322  * Open the tdb file upon VFS_CONNECT
 323  */
 324
 325 static bool xattr_tdb_init(int snum, TALLOC_CTX *mem_ctx, struct db_context **p_db)
 326 {
 327         struct db_context *db;
 328         const char *dbname;
 329         char *def_dbname;
 330
 331         def_dbname = state_path("xattr.tdb");
 332         if (def_dbname == NULL) {
 333                 errno = ENOSYS;
 334                 return false;
 335         }
 336
 337         dbname = lp_parm_const_string(snum, "xattr_tdb", "file", def_dbname);
 338
 339         /* now we know dbname is not NULL */
 340
 341         become_root();
 342         db = db_open(NULL, dbname, 0, TDB_DEFAULT, O_RDWR|O_CREAT, 0600,
 343                      DBWRAP_LOCK_ORDER_2, DBWRAP_FLAG_NONE);
 344         unbecome_root();
 345
 346         if (db == NULL) {
 347 #if defined(ENOTSUP)
 348                 errno = ENOTSUP;
 349 #else
 350                 errno = ENOSYS;
 351 #endif
 352                 TALLOC_FREE(def_dbname);
 353                 return false;
 354         }
 355
 356         *p_db = db;
 357         TALLOC_FREE(def_dbname);
 358         return true;
 359 }
 360
 361 static int xattr_tdb_open(vfs_handle_struct *handle,
 362                         struct smb_filename *smb_fname,
 363                         files_struct *fsp,
 364                         int flags,
 365                         mode_t mode)
 366 {
 367         struct db_context *db = NULL;
 368         TALLOC_CTX *frame = NULL;
 369         int ret;
 370
 371         fsp->fh->fd = SMB_VFS_NEXT_OPEN(handle,
 372                                 smb_fname, fsp,
 373                                 flags,
 374                                 mode);
 375
 376         if (fsp->fh->fd < 0) {
 377                 return fsp->fh->fd;
 378         }
 379
 380         if ((flags & (O_CREAT|O_EXCL)) != (O_CREAT|O_EXCL)) {
 381                 return fsp->fh->fd;
 382         }
 383
 384         /*
 385          * We know we used O_CREAT|O_EXCL and it worked.
 386          * We must have created the file.
 387          */
 388
 389         ret = SMB_VFS_FSTAT(fsp, &smb_fname->st);
 390         if (ret == -1) {
 391                 /* Can't happen... */
 392                 DBG_WARNING("SMB_VFS_FSTAT failed on file %s (%s)\n",
 393                         smb_fname_str_dbg(smb_fname),
 394                         strerror(errno));
 395                 return -1;
 396         }
 397         fsp->file_id = SMB_VFS_FILE_ID_CREATE(fsp->conn, &smb_fname->st);
 398
 399         frame = talloc_stackframe();
 400         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context,
 401                                 if (!xattr_tdb_init(-1, frame, &db))
 402                                 {
 403                                         TALLOC_FREE(frame); return -1;
 404                                 });
 405
 406         xattr_tdb_remove_all_attrs(db, &fsp->file_id);
 407         TALLOC_FREE(frame);
 408         return fsp->fh->fd;
 409 }
 410
 411 static int xattr_tdb_mkdir(vfs_handle_struct *handle,
 412                 const struct smb_filename *smb_fname,
 413                 mode_t mode)
 414 {
 415         struct db_context *db = NULL;
 416         TALLOC_CTX *frame = NULL;
 417         struct file_id fileid;
 418         int ret;
 419         struct smb_filename *smb_fname_tmp = NULL;
 420
 421         ret = SMB_VFS_NEXT_MKDIR(handle, smb_fname, mode);
 422         if (ret < 0) {
 423                 return ret;
 424         }
 425
 426         frame = talloc_stackframe();
 427         smb_fname_tmp = cp_smb_filename(frame, smb_fname);
 428         if (smb_fname_tmp == NULL) {
 429                 TALLOC_FREE(frame);
 430                 errno = ENOMEM;
 431                 return -1;
 432         }
 433
 434         /* Always use LSTAT here - we just creaded the directory. */
 435         ret = SMB_VFS_LSTAT(handle->conn, smb_fname_tmp);
 436         if (ret == -1) {
 437                 /* Rename race. Let upper level take care of it. */
 438                 TALLOC_FREE(frame);
 439                 return -1;
 440         }
 441         if (!S_ISDIR(smb_fname_tmp->st.st_ex_mode)) {
 442                 /* Rename race. Let upper level take care of it. */
 443                 TALLOC_FREE(frame);
 444                 return -1;
 445         }
 446
 447         fileid = SMB_VFS_FILE_ID_CREATE(handle->conn, &smb_fname_tmp->st);
 448
 449         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context,
 450                                 if (!xattr_tdb_init(-1, frame, &db))
 451                                 {
 452                                         TALLOC_FREE(frame); return -1;
 453                                 });
 454
 455         xattr_tdb_remove_all_attrs(db, &fileid);
 456         TALLOC_FREE(frame);
 457         return 0;
 458 }
 459
 460 /*
 461  * On unlink we need to delete the tdb record
 462  */
 463 static int xattr_tdb_unlink(vfs_handle_struct *handle,
 464                             const struct smb_filename *smb_fname)
 465 {
 466         struct smb_filename *smb_fname_tmp = NULL;
 467         struct file_id id;
 468         struct db_context *db;
 469         int ret = -1;
 470         bool remove_record = false;
 471         TALLOC_CTX *frame = talloc_stackframe();
 472
 473         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context,
 474                                 if (!xattr_tdb_init(-1, frame, &db))
 475                                 {
 476                                         TALLOC_FREE(frame); return -1;
 477                                 });
 478
 479         smb_fname_tmp = cp_smb_filename(frame, smb_fname);
 480         if (smb_fname_tmp == NULL) {
 481                 TALLOC_FREE(frame);
 482                 errno = ENOMEM;
 483                 return -1;
 484         }
 485
 486         if (smb_fname_tmp->flags & SMB_FILENAME_POSIX_PATH) {
 487                 ret = SMB_VFS_NEXT_LSTAT(handle, smb_fname_tmp);
 488         } else {
 489                 ret = SMB_VFS_NEXT_STAT(handle, smb_fname_tmp);
 490         }
 491         if (ret == -1) {
 492                 goto out;
 493         }
 494
 495         if (smb_fname_tmp->st.st_ex_nlink == 1) {
 496                 /* Only remove record on last link to file. */
 497                 remove_record = true;
 498         }
 499
 500         ret = SMB_VFS_NEXT_UNLINK(handle, smb_fname_tmp);
 501
 502         if (ret == -1) {
 503                 goto out;
 504         }
 505
 506         if (!remove_record) {
 507                 goto out;
 508         }
 509
 510         id = SMB_VFS_NEXT_FILE_ID_CREATE(handle, &smb_fname_tmp->st);
 511
 512         xattr_tdb_remove_all_attrs(db, &id);
 513
 514  out:
 515         TALLOC_FREE(frame);
 516         return ret;
 517 }
 518
 519 /*
 520  * On rmdir we need to delete the tdb record
 521  */
 522 static int xattr_tdb_rmdir(vfs_handle_struct *handle,
 523                         const struct smb_filename *smb_fname)
 524 {
 525         SMB_STRUCT_STAT sbuf;
 526         struct file_id id;
 527         struct db_context *db;
 528         int ret;
 529         TALLOC_CTX *frame = talloc_stackframe();
 530
 531         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context,
 532                                 if (!xattr_tdb_init(-1, frame, &db))
 533                                 {
 534                                         TALLOC_FREE(frame); return -1;
 535                                 });
 536
 537         if (vfs_stat_smb_basename(handle->conn,
 538                                 smb_fname,
 539                                 &sbuf) == -1) {
 540                 TALLOC_FREE(frame);
 541                 return -1;
 542         }
 543
 544         ret = SMB_VFS_NEXT_RMDIR(handle, smb_fname);
 545
 546         if (ret == -1) {
 547                 TALLOC_FREE(frame);
 548                 return -1;
 549         }
 550
 551         id = SMB_VFS_NEXT_FILE_ID_CREATE(handle, &sbuf);
 552
 553         xattr_tdb_remove_all_attrs(db, &id);
 554
 555         TALLOC_FREE(frame);
 556         return 0;
 557 }
 558
 559 /*
 560  * Destructor for the VFS private data
 561  */
 562
 563 static void close_xattr_db(void **data)
 564 {
 565         struct db_context **p_db = (struct db_context **)data;
 566         TALLOC_FREE(*p_db);
 567 }
 568
 569 static int xattr_tdb_connect(vfs_handle_struct *handle, const char *service,
 570                           const char *user)
 571 {
 572         char *sname = NULL;
 573         int res, snum;
 574         struct db_context *db;
 575
 576         res = SMB_VFS_NEXT_CONNECT(handle, service, user);
 577         if (res < 0) {
 578                 return res;
 579         }
 580
 581         snum = find_service(talloc_tos(), service, &sname);
 582         if (snum == -1 || sname == NULL) {
 583                 /*
 584                  * Should not happen, but we should not fail just *here*.
 585                  */
 586                 return 0;
 587         }
 588
 589         if (!xattr_tdb_init(snum, NULL, &db)) {
 590                 DEBUG(5, ("Could not init xattr tdb\n"));
 591                 lp_do_parameter(snum, "ea support", "False");
 592                 return 0;
 593         }
 594
 595         lp_do_parameter(snum, "ea support", "True");
 596
 597         SMB_VFS_HANDLE_SET_DATA(handle, db, close_xattr_db,
 598                                 struct db_context, return -1);
 599
 600         return 0;
 601 }
 602
 603 static struct vfs_fn_pointers vfs_xattr_tdb_fns = {
 604         .getxattr_fn = xattr_tdb_getxattr,
 605         .fgetxattr_fn = xattr_tdb_fgetxattr,
 606         .setxattr_fn = xattr_tdb_setxattr,
 607         .fsetxattr_fn = xattr_tdb_fsetxattr,
 608         .listxattr_fn = xattr_tdb_listxattr,
 609         .flistxattr_fn = xattr_tdb_flistxattr,
 610         .removexattr_fn = xattr_tdb_removexattr,
 611         .fremovexattr_fn = xattr_tdb_fremovexattr,
 612         .open_fn = xattr_tdb_open,
 613         .mkdir_fn = xattr_tdb_mkdir,
 614         .unlink_fn = xattr_tdb_unlink,
 615         .rmdir_fn = xattr_tdb_rmdir,
 616         .connect_fn = xattr_tdb_connect,
 617 };
 618
 619 static_decl_vfs;
 620 NTSTATUS vfs_xattr_tdb_init(TALLOC_CTX *ctx)
 621 {
 622         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "xattr_tdb",
 623                                 &vfs_xattr_tdb_fns);
 624 }