source3/lib/xattr_tdb.c

   1 /*
   2  * Store posix-level xattrs in a tdb
   3  *
   4  * Copyright (C) Andrew Bartlett 2011
   5  *
   6  * extracted from vfs_xattr_tdb by
   7  *
   8  * Copyright (C) Volker Lendecke, 2007
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 3 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  22  */
  23
  24 #include "source3/include/includes.h"
  25 #include "system/filesys.h"
  26 #include "librpc/gen_ndr/xattr.h"
  27 #include "librpc/gen_ndr/ndr_xattr.h"
  28 #include "librpc/gen_ndr/file_id.h"
  29 #include "dbwrap/dbwrap.h"
  30 #include "lib/util/util_tdb.h"
  31 #include "source3/lib/xattr_tdb.h"
  32 #include "source3/lib/file_id.h"
  33
  34 #undef DBGC_CLASS
  35 #define DBGC_CLASS DBGC_VFS
  36
  37 /*
  38  * unmarshall tdb_xattrs
  39  */
  40
  41 static NTSTATUS xattr_tdb_pull_attrs(TALLOC_CTX *mem_ctx,
  42                                      const TDB_DATA *data,
  43                                      struct tdb_xattrs **presult)
  44 {
  45         DATA_BLOB blob;
  46         enum ndr_err_code ndr_err;
  47         struct tdb_xattrs *result;
  48
  49         if (!(result = talloc_zero(mem_ctx, struct tdb_xattrs))) {
  50                 return NT_STATUS_NO_MEMORY;
  51         }
  52
  53         if (data->dsize == 0) {
  54                 *presult = result;
  55                 return NT_STATUS_OK;
  56         }
  57
  58         blob = data_blob_const(data->dptr, data->dsize);
  59
  60         ndr_err = ndr_pull_struct_blob(&blob, result, result,
  61                 (ndr_pull_flags_fn_t)ndr_pull_tdb_xattrs);
  62
  63         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
  64                 DEBUG(0, ("ndr_pull_tdb_xattrs failed: %s\n",
  65                           ndr_errstr(ndr_err)));
  66                 TALLOC_FREE(result);
  67                 return ndr_map_error2ntstatus(ndr_err);
  68         }
  69
  70         *presult = result;
  71         return NT_STATUS_OK;
  72 }
  73
  74 /*
  75  * marshall tdb_xattrs
  76  */
  77
  78 static NTSTATUS xattr_tdb_push_attrs(TALLOC_CTX *mem_ctx,
  79                                      const struct tdb_xattrs *attribs,
  80                                      TDB_DATA *data)
  81 {
  82         DATA_BLOB blob;
  83         enum ndr_err_code ndr_err;
  84
  85         ndr_err = ndr_push_struct_blob(&blob, mem_ctx, attribs,
  86                 (ndr_push_flags_fn_t)ndr_push_tdb_xattrs);
  87
  88         if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
  89                 DEBUG(0, ("ndr_push_tdb_xattrs failed: %s\n",
  90                           ndr_errstr(ndr_err)));
  91                 return ndr_map_error2ntstatus(ndr_err);
  92         }
  93
  94         *data = make_tdb_data(blob.data, blob.length);
  95         return NT_STATUS_OK;
  96 }
  97
  98 /*
  99  * Load tdb_xattrs for a file from the tdb
 100  */
 101
 102 static NTSTATUS xattr_tdb_load_attrs(TALLOC_CTX *mem_ctx,
 103                                      struct db_context *db_ctx,
 104                                      const struct file_id *id,
 105                                      struct tdb_xattrs **presult)
 106 {
 107         uint8_t id_buf[16];
 108         NTSTATUS status;
 109         TDB_DATA data;
 110
 111         /* For backwards compatibility only store the dev/inode. */
 112         push_file_id_16(id_buf, id);
 113
 114         status = dbwrap_fetch(db_ctx, mem_ctx,
 115                               make_tdb_data(id_buf, sizeof(id_buf)),
 116                               &data);
 117         if (!NT_STATUS_IS_OK(status)) {
 118                 if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
 119                         return status;
 120                 }
 121                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 122         }
 123
 124         status = xattr_tdb_pull_attrs(mem_ctx, &data, presult);
 125         TALLOC_FREE(data.dptr);
 126         return status;
 127 }
 128
 129 /*
 130  * fetch_lock the tdb_ea record for a file
 131  */
 132
 133 static struct db_record *xattr_tdb_lock_attrs(TALLOC_CTX *mem_ctx,
 134                                               struct db_context *db_ctx,
 135                                               const struct file_id *id)
 136 {
 137         uint8_t id_buf[16];
 138
 139         /* For backwards compatibility only store the dev/inode. */
 140         push_file_id_16(id_buf, id);
 141         return dbwrap_fetch_locked(db_ctx, mem_ctx,
 142                                    make_tdb_data(id_buf, sizeof(id_buf)));
 143 }
 144
 145 /*
 146  * Save tdb_xattrs to a previously fetch_locked record
 147  */
 148
 149 static NTSTATUS xattr_tdb_save_attrs(struct db_record *rec,
 150                                      const struct tdb_xattrs *attribs)
 151 {
 152         TDB_DATA data = tdb_null;
 153         NTSTATUS status;
 154
 155         status = xattr_tdb_push_attrs(talloc_tos(), attribs, &data);
 156
 157         if (!NT_STATUS_IS_OK(status)) {
 158                 DEBUG(0, ("xattr_tdb_push_attrs failed: %s\n",
 159                           nt_errstr(status)));
 160                 return status;
 161         }
 162
 163         status = dbwrap_record_store(rec, data, 0);
 164
 165         TALLOC_FREE(data.dptr);
 166
 167         return status;
 168 }
 169
 170 /*
 171  * Worker routine for getxattr and fgetxattr
 172  */
 173
 174 ssize_t xattr_tdb_getattr(struct db_context *db_ctx,
 175                           TALLOC_CTX *mem_ctx,
 176                           const struct file_id *id,
 177                           const char *name, DATA_BLOB *blob)
 178 {
 179         struct tdb_xattrs *attribs;
 180         uint32_t i;
 181         ssize_t result = -1;
 182         NTSTATUS status;
 183         TALLOC_CTX *frame = talloc_stackframe();
 184         struct file_id_buf buf;
 185
 186         DBG_DEBUG("xattr_tdb_getattr called for file %s, name %s\n",
 187                   file_id_str_buf(*id, &buf), name);
 188
 189         status = xattr_tdb_load_attrs(frame, db_ctx, id, &attribs);
 190
 191         if (!NT_STATUS_IS_OK(status)) {
 192                 DEBUG(10, ("xattr_tdb_fetch_attrs failed: %s\n",
 193                            nt_errstr(status)));
 194                 TALLOC_FREE(frame);
 195                 errno = EINVAL;
 196                 return -1;
 197         }
 198
 199         for (i=0; i<attribs->num_eas; i++) {
 200                 if (strcmp(attribs->eas[i].name, name) == 0) {
 201                         break;
 202                 }
 203         }
 204
 205         if (i == attribs->num_eas) {
 206                 errno = ENOATTR;
 207                 goto fail;
 208         }
 209
 210         *blob = attribs->eas[i].value;
 211         talloc_steal(mem_ctx, blob->data);
 212         result = attribs->eas[i].value.length;
 213
 214  fail:
 215         TALLOC_FREE(frame);
 216         return result;
 217 }
 218
 219 /*
 220  * Worker routine for setxattr and fsetxattr
 221  */
 222
 223 int xattr_tdb_setattr(struct db_context *db_ctx,
 224                       const struct file_id *id, const char *name,
 225                       const void *value, size_t size, int flags)
 226 {
 227         NTSTATUS status;
 228         struct db_record *rec;
 229         struct tdb_xattrs *attribs;
 230         uint32_t i;
 231         TDB_DATA data;
 232         TALLOC_CTX *frame = talloc_stackframe();
 233         struct file_id_buf buf;
 234
 235         DBG_DEBUG("xattr_tdb_setattr called for file %s, name %s\n",
 236                   file_id_str_buf(*id, &buf), name);
 237
 238         rec = xattr_tdb_lock_attrs(frame, db_ctx, id);
 239
 240         if (rec == NULL) {
 241                 DEBUG(0, ("xattr_tdb_lock_attrs failed\n"));
 242                 errno = EINVAL;
 243                 return -1;
 244         }
 245
 246         data = dbwrap_record_get_value(rec);
 247
 248         status = xattr_tdb_pull_attrs(rec, &data, &attribs);
 249
 250         if (!NT_STATUS_IS_OK(status)) {
 251                 DEBUG(10, ("xattr_tdb_fetch_attrs failed: %s\n",
 252                            nt_errstr(status)));
 253                 TALLOC_FREE(frame);
 254                 return -1;
 255         }
 256
 257         for (i=0; i<attribs->num_eas; i++) {
 258                 if (strcmp(attribs->eas[i].name, name) == 0) {
 259                         if (flags & XATTR_CREATE) {
 260                                 TALLOC_FREE(frame);
 261                                 errno = EEXIST;
 262                                 return -1;
 263                         }
 264                         break;
 265                 }
 266         }
 267
 268         if (i == attribs->num_eas) {
 269                 struct xattr_EA *tmp;
 270
 271                 if (flags & XATTR_REPLACE) {
 272                         TALLOC_FREE(frame);
 273                         errno = ENOATTR;
 274                         return -1;
 275                 }
 276
 277                 tmp = talloc_realloc(
 278                         attribs, attribs->eas, struct xattr_EA,
 279                         attribs->num_eas+ 1);
 280
 281                 if (tmp == NULL) {
 282                         DEBUG(0, ("talloc_realloc failed\n"));
 283                         TALLOC_FREE(frame);
 284                         errno = ENOMEM;
 285                         return -1;
 286                 }
 287
 288                 attribs->eas = tmp;
 289                 attribs->num_eas += 1;
 290         }
 291
 292         attribs->eas[i].name = name;
 293         attribs->eas[i].value.data = discard_const_p(uint8_t, value);
 294         attribs->eas[i].value.length = size;
 295
 296         status = xattr_tdb_save_attrs(rec, attribs);
 297
 298         TALLOC_FREE(frame);
 299
 300         if (!NT_STATUS_IS_OK(status)) {
 301                 DEBUG(1, ("save failed: %s\n", nt_errstr(status)));
 302                 return -1;
 303         }
 304
 305         return 0;
 306 }
 307
 308 /*
 309  * Worker routine for listxattr and flistxattr
 310  */
 311
 312 ssize_t xattr_tdb_listattr(struct db_context *db_ctx,
 313                            const struct file_id *id, char *list,
 314                            size_t size)
 315 {
 316         NTSTATUS status;
 317         struct tdb_xattrs *attribs;
 318         uint32_t i;
 319         size_t len = 0;
 320         TALLOC_CTX *frame = talloc_stackframe();
 321
 322         status = xattr_tdb_load_attrs(frame, db_ctx, id, &attribs);
 323
 324         if (!NT_STATUS_IS_OK(status) &&
 325             !NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND))
 326         {
 327                 DEBUG(0, ("xattr_tdb_fetch_attrs failed: %s\n",
 328                            nt_errstr(status)));
 329                 errno = EINVAL;
 330                 TALLOC_FREE(frame);
 331                 return -1;
 332         }
 333
 334         if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
 335                 TALLOC_FREE(frame);
 336                 return 0;
 337         }
 338
 339         DEBUG(10, ("xattr_tdb_listattr: Found %d xattrs\n",
 340                    attribs->num_eas));
 341
 342         for (i=0; i<attribs->num_eas; i++) {
 343                 size_t tmp;
 344
 345                 DEBUG(10, ("xattr_tdb_listattr: xattrs[i].name: %s\n",
 346                            attribs->eas[i].name));
 347
 348                 tmp = strlen(attribs->eas[i].name);
 349
 350                 /*
 351                  * Try to protect against overflow
 352                  */
 353
 354                 if (len + (tmp+1) < len) {
 355                         TALLOC_FREE(frame);
 356                         errno = EINVAL;
 357                         return -1;
 358                 }
 359
 360                 /*
 361                  * Take care of the terminating NULL
 362                  */
 363                 len += (tmp + 1);
 364         }
 365
 366         if (len > size) {
 367                 TALLOC_FREE(frame);
 368                 errno = ERANGE;
 369                 return len;
 370         }
 371
 372         len = 0;
 373
 374         for (i=0; i<attribs->num_eas; i++) {
 375                 strlcpy(list+len, attribs->eas[i].name,
 376                         size-len);
 377                 len += (strlen(attribs->eas[i].name) + 1);
 378         }
 379
 380         TALLOC_FREE(frame);
 381         return len;
 382 }
 383
 384 /*
 385  * Worker routine for removexattr and fremovexattr
 386  */
 387
 388 int xattr_tdb_removeattr(struct db_context *db_ctx,
 389                          const struct file_id *id, const char *name)
 390 {
 391         NTSTATUS status;
 392         struct db_record *rec;
 393         struct tdb_xattrs *attribs;
 394         uint32_t i;
 395         TDB_DATA value;
 396
 397         rec = xattr_tdb_lock_attrs(talloc_tos(), db_ctx, id);
 398
 399         if (rec == NULL) {
 400                 DEBUG(0, ("xattr_tdb_lock_attrs failed\n"));
 401                 errno = EINVAL;
 402                 return -1;
 403         }
 404
 405         value = dbwrap_record_get_value(rec);
 406
 407         status = xattr_tdb_pull_attrs(rec, &value, &attribs);
 408
 409         if (!NT_STATUS_IS_OK(status)) {
 410                 DEBUG(10, ("xattr_tdb_fetch_attrs failed: %s\n",
 411                            nt_errstr(status)));
 412                 TALLOC_FREE(rec);
 413                 return -1;
 414         }
 415
 416         for (i=0; i<attribs->num_eas; i++) {
 417                 if (strcmp(attribs->eas[i].name, name) == 0) {
 418                         break;
 419                 }
 420         }
 421
 422         if (i == attribs->num_eas) {
 423                 TALLOC_FREE(rec);
 424                 errno = ENOATTR;
 425                 return -1;
 426         }
 427
 428         attribs->eas[i] =
 429                 attribs->eas[attribs->num_eas-1];
 430         attribs->num_eas -= 1;
 431
 432         if (attribs->num_eas == 0) {
 433                 dbwrap_record_delete(rec);
 434                 TALLOC_FREE(rec);
 435                 return 0;
 436         }
 437
 438         status = xattr_tdb_save_attrs(rec, attribs);
 439
 440         TALLOC_FREE(rec);
 441
 442         if (!NT_STATUS_IS_OK(status)) {
 443                 DEBUG(1, ("save failed: %s\n", nt_errstr(status)));
 444                 return -1;
 445         }
 446
 447         return 0;
 448 }
 449
 450 /*
 451  * Worker routine for unlink and rmdir
 452  */
 453
 454 void xattr_tdb_remove_all_attrs(struct db_context *db_ctx,
 455                                const struct file_id *id)
 456 {
 457         struct db_record *rec;
 458         rec = xattr_tdb_lock_attrs(talloc_tos(), db_ctx, id);
 459
 460         /*
 461          * If rec == NULL there's not much we can do about it
 462          */
 463
 464         if (rec != NULL) {
 465                 dbwrap_record_delete(rec);
 466                 TALLOC_FREE(rec);
 467         }
 468 }