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_split(frame, path, NULL);
  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 char *path, const char *name,
  61                                   void *value, size_t size)
  62 {
  63         struct file_id id;
  64         struct db_context *db;
  65         ssize_t xattr_size;
  66         int ret;
  67         DATA_BLOB blob;
  68         TALLOC_CTX *frame = talloc_stackframe();
  69
  70         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context,
  71                                 if (!xattr_tdb_init(-1, frame, &db))
  72                                 {
  73                                         TALLOC_FREE(frame); return -1;
  74                                 });
  75
  76         ret = xattr_tdb_get_file_id(handle, path, &id);
  77         if (ret == -1) {
  78                 TALLOC_FREE(frame);
  79                 return -1;
  80         }
  81
  82         xattr_size = xattr_tdb_getattr(db, frame, &id, name, &blob);
  83         if (xattr_size < 0) {
  84                 errno = ENOATTR;
  85                 TALLOC_FREE(frame);
  86                 return -1;
  87         }
  88         if (blob.length > size) {
  89                 TALLOC_FREE(frame);
  90                 errno = ERANGE;
  91                 return -1;
  92         }
  93         memcpy(value, blob.data, xattr_size);
  94         TALLOC_FREE(frame);
  95         return xattr_size;
  96 }
  97
  98 static ssize_t xattr_tdb_fgetxattr(struct vfs_handle_struct *handle,
  99                                    struct files_struct *fsp,
 100                                    const char *name, void *value, size_t size)
 101 {
 102         SMB_STRUCT_STAT sbuf;
 103         struct file_id id;
 104         struct db_context *db;
 105         ssize_t xattr_size;
 106         DATA_BLOB blob;
 107         TALLOC_CTX *frame = talloc_stackframe();
 108
 109         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context,
 110                                 if (!xattr_tdb_init(-1, frame, &db))
 111                                 {
 112                                         TALLOC_FREE(frame); return -1;
 113                                 });
 114
 115         if (SMB_VFS_NEXT_FSTAT(handle, fsp, &sbuf) == -1) {
 116                 TALLOC_FREE(frame);
 117                 return -1;
 118         }
 119
 120         id = SMB_VFS_NEXT_FILE_ID_CREATE(handle, &sbuf);
 121
 122         xattr_size = xattr_tdb_getattr(db, frame, &id, name, &blob);
 123         if (xattr_size < 0) {
 124                 errno = ENOATTR;
 125                 TALLOC_FREE(frame);
 126                 return -1;
 127         }
 128         if (blob.length > size) {
 129                 TALLOC_FREE(frame);
 130                 errno = ERANGE;
 131                 return -1;
 132         }
 133         memcpy(value, blob.data, xattr_size);
 134         TALLOC_FREE(frame);
 135         return xattr_size;
 136 }
 137
 138 static int xattr_tdb_setxattr(struct vfs_handle_struct *handle,
 139                               const char *path, const char *name,
 140                               const void *value, size_t size, int flags)
 141 {
 142         struct file_id id;
 143         struct db_context *db;
 144         int ret;
 145         TALLOC_CTX *frame = talloc_stackframe();
 146
 147         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context,
 148                                 if (!xattr_tdb_init(-1, frame, &db))
 149                                 {
 150                                         TALLOC_FREE(frame); return -1;
 151                                 });
 152
 153         ret = xattr_tdb_get_file_id(handle, path, &id);
 154         if (ret == -1) {
 155                 TALLOC_FREE(frame);
 156                 return -1;
 157         }
 158
 159         ret = xattr_tdb_setattr(db, &id, name, value, size, flags);
 160         TALLOC_FREE(frame);
 161         return ret;
 162 }
 163
 164 static int xattr_tdb_fsetxattr(struct vfs_handle_struct *handle,
 165                                struct files_struct *fsp,
 166                                const char *name, const void *value,
 167                                size_t size, int flags)
 168 {
 169         SMB_STRUCT_STAT sbuf;
 170         struct file_id id;
 171         struct db_context *db;
 172         int ret;
 173         TALLOC_CTX *frame = talloc_stackframe();
 174
 175         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context,
 176                                 if (!xattr_tdb_init(-1, frame, &db))
 177                                 {
 178                                         TALLOC_FREE(frame); return -1;
 179                                 });
 180
 181         if (SMB_VFS_NEXT_FSTAT(handle, fsp, &sbuf) == -1) {
 182                 TALLOC_FREE(frame);
 183                 return -1;
 184         }
 185
 186         id = SMB_VFS_NEXT_FILE_ID_CREATE(handle, &sbuf);
 187
 188         ret = xattr_tdb_setattr(db, &id, name, value, size, flags);
 189         TALLOC_FREE(frame);
 190         return ret;
 191
 192 }
 193
 194 static ssize_t xattr_tdb_listxattr(struct vfs_handle_struct *handle,
 195                                    const char *path, char *list, size_t size)
 196 {
 197         struct file_id id;
 198         struct db_context *db;
 199         int ret;
 200         TALLOC_CTX *frame = talloc_stackframe();
 201
 202         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context,
 203                                 if (!xattr_tdb_init(-1, frame, &db))
 204                                 {
 205                                         TALLOC_FREE(frame); return -1;
 206                                 });
 207
 208         ret = xattr_tdb_get_file_id(handle, path, &id);
 209         if (ret == -1) {
 210                 TALLOC_FREE(frame);
 211                 return -1;
 212         }
 213
 214         ret = xattr_tdb_listattr(db, &id, list, size);
 215         TALLOC_FREE(frame);
 216         return ret;
 217
 218 }
 219
 220 static ssize_t xattr_tdb_flistxattr(struct vfs_handle_struct *handle,
 221                                     struct files_struct *fsp, char *list,
 222                                     size_t size)
 223 {
 224         SMB_STRUCT_STAT sbuf;
 225         struct file_id id;
 226         struct db_context *db;
 227         int ret;
 228         TALLOC_CTX *frame = talloc_stackframe();
 229
 230         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context,
 231                                 if (!xattr_tdb_init(-1, frame, &db))
 232                                 {
 233                                         TALLOC_FREE(frame); return -1;
 234                                 });
 235
 236         if (SMB_VFS_NEXT_FSTAT(handle, fsp, &sbuf) == -1) {
 237                 TALLOC_FREE(frame);
 238                 return -1;
 239         }
 240
 241         id = SMB_VFS_NEXT_FILE_ID_CREATE(handle, &sbuf);
 242
 243         ret = xattr_tdb_listattr(db, &id, list, size);
 244         TALLOC_FREE(frame);
 245         return ret;
 246 }
 247
 248 static int xattr_tdb_removexattr(struct vfs_handle_struct *handle,
 249                                  const char *path, const char *name)
 250 {
 251         struct file_id id;
 252         struct db_context *db;
 253         int ret;
 254         TALLOC_CTX *frame = talloc_stackframe();
 255
 256         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context,
 257                                 if (!xattr_tdb_init(-1, frame, &db))
 258                                 {
 259                                         TALLOC_FREE(frame); return -1;
 260                                 });
 261
 262         ret = xattr_tdb_get_file_id(handle, path, &id);
 263         if (ret == -1) {
 264                 TALLOC_FREE(frame);
 265                 return ret;
 266         }
 267
 268
 269         ret = xattr_tdb_removeattr(db, &id, name);
 270         TALLOC_FREE(frame);
 271         return ret;
 272 }
 273
 274 static int xattr_tdb_fremovexattr(struct vfs_handle_struct *handle,
 275                                   struct files_struct *fsp, const char *name)
 276 {
 277         SMB_STRUCT_STAT sbuf;
 278         struct file_id id;
 279         struct db_context *db;
 280         int ret;
 281         TALLOC_CTX *frame = talloc_stackframe();
 282
 283         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context,
 284                                 if (!xattr_tdb_init(-1, frame, &db))
 285                                 {
 286                                         TALLOC_FREE(frame); return -1;
 287                                 });
 288
 289         if (SMB_VFS_NEXT_FSTAT(handle, fsp, &sbuf) == -1) {
 290                 TALLOC_FREE(frame);
 291                 return -1;
 292         }
 293
 294         id = SMB_VFS_NEXT_FILE_ID_CREATE(handle, &sbuf);
 295
 296         ret = xattr_tdb_removeattr(db, &id, name);
 297         TALLOC_FREE(frame);
 298         return ret;
 299 }
 300
 301 /*
 302  * Open the tdb file upon VFS_CONNECT
 303  */
 304
 305 static bool xattr_tdb_init(int snum, TALLOC_CTX *mem_ctx, struct db_context **p_db)
 306 {
 307         struct db_context *db;
 308         const char *dbname;
 309         char *def_dbname;
 310
 311         def_dbname = state_path("xattr.tdb");
 312         if (def_dbname == NULL) {
 313                 errno = ENOSYS;
 314                 return false;
 315         }
 316
 317         dbname = lp_parm_const_string(snum, "xattr_tdb", "file", def_dbname);
 318
 319         /* now we know dbname is not NULL */
 320
 321         become_root();
 322         db = db_open(NULL, dbname, 0, TDB_DEFAULT, O_RDWR|O_CREAT, 0600,
 323                      DBWRAP_LOCK_ORDER_2, DBWRAP_FLAG_NONE);
 324         unbecome_root();
 325
 326         if (db == NULL) {
 327 #if defined(ENOTSUP)
 328                 errno = ENOTSUP;
 329 #else
 330                 errno = ENOSYS;
 331 #endif
 332                 TALLOC_FREE(def_dbname);
 333                 return false;
 334         }
 335
 336         *p_db = db;
 337         TALLOC_FREE(def_dbname);
 338         return true;
 339 }
 340
 341 /*
 342  * On unlink we need to delete the tdb record
 343  */
 344 static int xattr_tdb_unlink(vfs_handle_struct *handle,
 345                             const struct smb_filename *smb_fname)
 346 {
 347         struct smb_filename *smb_fname_tmp = NULL;
 348         struct file_id id;
 349         struct db_context *db;
 350         int ret = -1;
 351         bool remove_record = false;
 352         TALLOC_CTX *frame = talloc_stackframe();
 353
 354         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context,
 355                                 if (!xattr_tdb_init(-1, frame, &db))
 356                                 {
 357                                         TALLOC_FREE(frame); return -1;
 358                                 });
 359
 360         smb_fname_tmp = cp_smb_filename(frame, smb_fname);
 361         if (smb_fname_tmp == NULL) {
 362                 TALLOC_FREE(frame);
 363                 errno = ENOMEM;
 364                 return -1;
 365         }
 366
 367         if (lp_posix_pathnames()) {
 368                 ret = SMB_VFS_NEXT_LSTAT(handle, smb_fname_tmp);
 369         } else {
 370                 ret = SMB_VFS_NEXT_STAT(handle, smb_fname_tmp);
 371         }
 372         if (ret == -1) {
 373                 goto out;
 374         }
 375
 376         if (smb_fname_tmp->st.st_ex_nlink == 1) {
 377                 /* Only remove record on last link to file. */
 378                 remove_record = true;
 379         }
 380
 381         ret = SMB_VFS_NEXT_UNLINK(handle, smb_fname_tmp);
 382
 383         if (ret == -1) {
 384                 goto out;
 385         }
 386
 387         if (!remove_record) {
 388                 goto out;
 389         }
 390
 391         id = SMB_VFS_NEXT_FILE_ID_CREATE(handle, &smb_fname_tmp->st);
 392
 393         xattr_tdb_remove_all_attrs(db, &id);
 394
 395  out:
 396         TALLOC_FREE(frame);
 397         return ret;
 398 }
 399
 400 /*
 401  * On rmdir we need to delete the tdb record
 402  */
 403 static int xattr_tdb_rmdir(vfs_handle_struct *handle, const char *path)
 404 {
 405         SMB_STRUCT_STAT sbuf;
 406         struct file_id id;
 407         struct db_context *db;
 408         int ret;
 409         TALLOC_CTX *frame = talloc_stackframe();
 410
 411         SMB_VFS_HANDLE_GET_DATA(handle, db, struct db_context,
 412                                 if (!xattr_tdb_init(-1, frame, &db))
 413                                 {
 414                                         TALLOC_FREE(frame); return -1;
 415                                 });
 416
 417         if (vfs_stat_smb_fname(handle->conn, path, &sbuf) == -1) {
 418                 TALLOC_FREE(frame);
 419                 return -1;
 420         }
 421
 422         ret = SMB_VFS_NEXT_RMDIR(handle, path);
 423
 424         if (ret == -1) {
 425                 TALLOC_FREE(frame);
 426                 return -1;
 427         }
 428
 429         id = SMB_VFS_NEXT_FILE_ID_CREATE(handle, &sbuf);
 430
 431         xattr_tdb_remove_all_attrs(db, &id);
 432
 433         TALLOC_FREE(frame);
 434         return 0;
 435 }
 436
 437 /*
 438  * Destructor for the VFS private data
 439  */
 440
 441 static void close_xattr_db(void **data)
 442 {
 443         struct db_context **p_db = (struct db_context **)data;
 444         TALLOC_FREE(*p_db);
 445 }
 446
 447 static int xattr_tdb_connect(vfs_handle_struct *handle, const char *service,
 448                           const char *user)
 449 {
 450         char *sname = NULL;
 451         int res, snum;
 452         struct db_context *db;
 453
 454         res = SMB_VFS_NEXT_CONNECT(handle, service, user);
 455         if (res < 0) {
 456                 return res;
 457         }
 458
 459         snum = find_service(talloc_tos(), service, &sname);
 460         if (snum == -1 || sname == NULL) {
 461                 /*
 462                  * Should not happen, but we should not fail just *here*.
 463                  */
 464                 return 0;
 465         }
 466
 467         if (!xattr_tdb_init(snum, NULL, &db)) {
 468                 DEBUG(5, ("Could not init xattr tdb\n"));
 469                 lp_do_parameter(snum, "ea support", "False");
 470                 return 0;
 471         }
 472
 473         lp_do_parameter(snum, "ea support", "True");
 474
 475         SMB_VFS_HANDLE_SET_DATA(handle, db, close_xattr_db,
 476                                 struct db_context, return -1);
 477
 478         return 0;
 479 }
 480
 481 static struct vfs_fn_pointers vfs_xattr_tdb_fns = {
 482         .getxattr_fn = xattr_tdb_getxattr,
 483         .fgetxattr_fn = xattr_tdb_fgetxattr,
 484         .setxattr_fn = xattr_tdb_setxattr,
 485         .fsetxattr_fn = xattr_tdb_fsetxattr,
 486         .listxattr_fn = xattr_tdb_listxattr,
 487         .flistxattr_fn = xattr_tdb_flistxattr,
 488         .removexattr_fn = xattr_tdb_removexattr,
 489         .fremovexattr_fn = xattr_tdb_fremovexattr,
 490         .unlink_fn = xattr_tdb_unlink,
 491         .rmdir_fn = xattr_tdb_rmdir,
 492         .connect_fn = xattr_tdb_connect,
 493 };
 494
 495 NTSTATUS vfs_xattr_tdb_init(void);
 496 NTSTATUS vfs_xattr_tdb_init(void)
 497 {
 498         return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "xattr_tdb",
 499                                 &vfs_xattr_tdb_fns);
 500 }