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 "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((char *)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                 return NT_STATUS_INTERNAL_DB_CORRUPTION;
 119         }
 120
 121         status = xattr_tdb_pull_attrs(mem_ctx, &data, presult);
 122         TALLOC_FREE(data.dptr);
 123         return status;
 124 }
 125
 126 /*
 127  * fetch_lock the tdb_ea record for a file
 128  */
 129
 130 static struct db_record *xattr_tdb_lock_attrs(TALLOC_CTX *mem_ctx,
 131                                               struct db_context *db_ctx,
 132                                               const struct file_id *id)
 133 {
 134         uint8_t id_buf[16];
 135
 136         /* For backwards compatibility only store the dev/inode. */
 137         push_file_id_16((char *)id_buf, id);
 138         return dbwrap_fetch_locked(db_ctx, mem_ctx,
 139                                    make_tdb_data(id_buf, sizeof(id_buf)));
 140 }
 141
 142 /*
 143  * Save tdb_xattrs to a previously fetch_locked record
 144  */
 145
 146 static NTSTATUS xattr_tdb_save_attrs(struct db_record *rec,
 147                                      const struct tdb_xattrs *attribs)
 148 {
 149         TDB_DATA data = tdb_null;
 150         NTSTATUS status;
 151
 152         status = xattr_tdb_push_attrs(talloc_tos(), attribs, &data);
 153
 154         if (!NT_STATUS_IS_OK(status)) {
 155                 DEBUG(0, ("xattr_tdb_push_attrs failed: %s\n",
 156                           nt_errstr(status)));
 157                 return status;
 158         }
 159
 160         status = dbwrap_record_store(rec, data, 0);
 161
 162         TALLOC_FREE(data.dptr);
 163
 164         return status;
 165 }
 166
 167 /*
 168  * Worker routine for getxattr and fgetxattr
 169  */
 170
 171 ssize_t xattr_tdb_getattr(struct db_context *db_ctx,
 172                           TALLOC_CTX *mem_ctx,
 173                           const struct file_id *id,
 174                           const char *name, DATA_BLOB *blob)
 175 {
 176         struct tdb_xattrs *attribs;
 177         uint32_t i;
 178         ssize_t result = -1;
 179         NTSTATUS status;
 180         TALLOC_CTX *frame = talloc_stackframe();
 181
 182         DEBUG(10, ("xattr_tdb_getattr called for file %s, name %s\n",
 183                    file_id_string(frame, id), name));
 184
 185         status = xattr_tdb_load_attrs(frame, db_ctx, id, &attribs);
 186
 187         if (!NT_STATUS_IS_OK(status)) {
 188                 DEBUG(10, ("xattr_tdb_fetch_attrs failed: %s\n",
 189                            nt_errstr(status)));
 190                 TALLOC_FREE(frame);
 191                 errno = EINVAL;
 192                 return -1;
 193         }
 194
 195         for (i=0; i<attribs->num_eas; i++) {
 196                 if (strcmp(attribs->eas[i].name, name) == 0) {
 197                         break;
 198                 }
 199         }
 200
 201         if (i == attribs->num_eas) {
 202                 errno = ENOATTR;
 203                 goto fail;
 204         }
 205
 206         *blob = attribs->eas[i].value;
 207         talloc_steal(mem_ctx, blob->data);
 208         result = attribs->eas[i].value.length;
 209
 210  fail:
 211         TALLOC_FREE(frame);
 212         return result;
 213 }
 214
 215 /*
 216  * Worker routine for setxattr and fsetxattr
 217  */
 218
 219 int xattr_tdb_setattr(struct db_context *db_ctx,
 220                       const struct file_id *id, const char *name,
 221                       const void *value, size_t size, int flags)
 222 {
 223         NTSTATUS status;
 224         struct db_record *rec;
 225         struct tdb_xattrs *attribs;
 226         uint32_t i;
 227         TDB_DATA data;
 228         TALLOC_CTX *frame = talloc_stackframe();
 229
 230         DEBUG(10, ("xattr_tdb_setattr called for file %s, name %s\n",
 231                    file_id_string(frame, id), name));
 232
 233         rec = xattr_tdb_lock_attrs(frame, db_ctx, id);
 234
 235         if (rec == NULL) {
 236                 DEBUG(0, ("xattr_tdb_lock_attrs failed\n"));
 237                 errno = EINVAL;
 238                 return -1;
 239         }
 240
 241         data = dbwrap_record_get_value(rec);
 242
 243         status = xattr_tdb_pull_attrs(rec, &data, &attribs);
 244
 245         if (!NT_STATUS_IS_OK(status)) {
 246                 DEBUG(10, ("xattr_tdb_fetch_attrs failed: %s\n",
 247                            nt_errstr(status)));
 248                 TALLOC_FREE(frame);
 249                 return -1;
 250         }
 251
 252         for (i=0; i<attribs->num_eas; i++) {
 253                 if (strcmp(attribs->eas[i].name, name) == 0) {
 254                         if (flags & XATTR_CREATE) {
 255                                 TALLOC_FREE(frame);
 256                                 errno = EEXIST;
 257                                 return -1;
 258                         }
 259                         break;
 260                 }
 261         }
 262
 263         if (i == attribs->num_eas) {
 264                 struct xattr_EA *tmp;
 265
 266                 if (flags & XATTR_REPLACE) {
 267                         TALLOC_FREE(frame);
 268                         errno = ENOATTR;
 269                         return -1;
 270                 }
 271
 272                 tmp = talloc_realloc(
 273                         attribs, attribs->eas, struct xattr_EA,
 274                         attribs->num_eas+ 1);
 275
 276                 if (tmp == NULL) {
 277                         DEBUG(0, ("talloc_realloc failed\n"));
 278                         TALLOC_FREE(frame);
 279                         errno = ENOMEM;
 280                         return -1;
 281                 }
 282
 283                 attribs->eas = tmp;
 284                 attribs->num_eas += 1;
 285         }
 286
 287         attribs->eas[i].name = name;
 288         attribs->eas[i].value.data = discard_const_p(uint8_t, value);
 289         attribs->eas[i].value.length = size;
 290
 291         status = xattr_tdb_save_attrs(rec, attribs);
 292
 293         TALLOC_FREE(frame);
 294
 295         if (!NT_STATUS_IS_OK(status)) {
 296                 DEBUG(1, ("save failed: %s\n", nt_errstr(status)));
 297                 return -1;
 298         }
 299
 300         return 0;
 301 }
 302
 303 /*
 304  * Worker routine for listxattr and flistxattr
 305  */
 306
 307 ssize_t xattr_tdb_listattr(struct db_context *db_ctx,
 308                            const struct file_id *id, char *list,
 309                            size_t size)
 310 {
 311         NTSTATUS status;
 312         struct tdb_xattrs *attribs;
 313         uint32_t i;
 314         size_t len = 0;
 315         TALLOC_CTX *frame = talloc_stackframe();
 316
 317         status = xattr_tdb_load_attrs(frame, db_ctx, id, &attribs);
 318
 319         if (!NT_STATUS_IS_OK(status)) {
 320                 DEBUG(10, ("xattr_tdb_fetch_attrs failed: %s\n",
 321                            nt_errstr(status)));
 322                 errno = EINVAL;
 323                 TALLOC_FREE(frame);
 324                 return -1;
 325         }
 326
 327         DEBUG(10, ("xattr_tdb_listattr: Found %d xattrs\n",
 328                    attribs->num_eas));
 329
 330         for (i=0; i<attribs->num_eas; i++) {
 331                 size_t tmp;
 332
 333                 DEBUG(10, ("xattr_tdb_listattr: xattrs[i].name: %s\n",
 334                            attribs->eas[i].name));
 335
 336                 tmp = strlen(attribs->eas[i].name);
 337
 338                 /*
 339                  * Try to protect against overflow
 340                  */
 341
 342                 if (len + (tmp+1) < len) {
 343                         TALLOC_FREE(frame);
 344                         errno = EINVAL;
 345                         return -1;
 346                 }
 347
 348                 /*
 349                  * Take care of the terminating NULL
 350                  */
 351                 len += (tmp + 1);
 352         }
 353
 354         if (len > size) {
 355                 TALLOC_FREE(frame);
 356                 errno = ERANGE;
 357                 return len;
 358         }
 359
 360         len = 0;
 361
 362         for (i=0; i<attribs->num_eas; i++) {
 363                 strlcpy(list+len, attribs->eas[i].name,
 364                         size-len);
 365                 len += (strlen(attribs->eas[i].name) + 1);
 366         }
 367
 368         TALLOC_FREE(frame);
 369         return len;
 370 }
 371
 372 /*
 373  * Worker routine for removexattr and fremovexattr
 374  */
 375
 376 int xattr_tdb_removeattr(struct db_context *db_ctx,
 377                          const struct file_id *id, const char *name)
 378 {
 379         NTSTATUS status;
 380         struct db_record *rec;
 381         struct tdb_xattrs *attribs;
 382         uint32_t i;
 383         TDB_DATA value;
 384
 385         rec = xattr_tdb_lock_attrs(talloc_tos(), db_ctx, id);
 386
 387         if (rec == NULL) {
 388                 DEBUG(0, ("xattr_tdb_lock_attrs failed\n"));
 389                 errno = EINVAL;
 390                 return -1;
 391         }
 392
 393         value = dbwrap_record_get_value(rec);
 394
 395         status = xattr_tdb_pull_attrs(rec, &value, &attribs);
 396
 397         if (!NT_STATUS_IS_OK(status)) {
 398                 DEBUG(10, ("xattr_tdb_fetch_attrs failed: %s\n",
 399                            nt_errstr(status)));
 400                 TALLOC_FREE(rec);
 401                 return -1;
 402         }
 403
 404         for (i=0; i<attribs->num_eas; i++) {
 405                 if (strcmp(attribs->eas[i].name, name) == 0) {
 406                         break;
 407                 }
 408         }
 409
 410         if (i == attribs->num_eas) {
 411                 TALLOC_FREE(rec);
 412                 errno = ENOATTR;
 413                 return -1;
 414         }
 415
 416         attribs->eas[i] =
 417                 attribs->eas[attribs->num_eas-1];
 418         attribs->num_eas -= 1;
 419
 420         if (attribs->num_eas == 0) {
 421                 dbwrap_record_delete(rec);
 422                 TALLOC_FREE(rec);
 423                 return 0;
 424         }
 425
 426         status = xattr_tdb_save_attrs(rec, attribs);
 427
 428         TALLOC_FREE(rec);
 429
 430         if (!NT_STATUS_IS_OK(status)) {
 431                 DEBUG(1, ("save failed: %s\n", nt_errstr(status)));
 432                 return -1;
 433         }
 434
 435         return 0;
 436 }
 437
 438 /*
 439  * Worker routine for unlink and rmdir
 440  */
 441
 442 void xattr_tdb_remove_all_attrs(struct db_context *db_ctx,
 443                                const struct file_id *id)
 444 {
 445         struct db_record *rec;
 446         rec = xattr_tdb_lock_attrs(talloc_tos(), db_ctx, id);
 447
 448         /*
 449          * If rec == NULL there's not much we can do about it
 450          */
 451
 452         if (rec != NULL) {
 453                 dbwrap_record_delete(rec);
 454                 TALLOC_FREE(rec);
 455         }
 456 }