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((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                 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((char *)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
 185         DEBUG(10, ("xattr_tdb_getattr called for file %s, name %s\n",
 186                    file_id_string(frame, id), name));
 187
 188         status = xattr_tdb_load_attrs(frame, db_ctx, id, &attribs);
 189
 190         if (!NT_STATUS_IS_OK(status)) {
 191                 DEBUG(10, ("xattr_tdb_fetch_attrs failed: %s\n",
 192                            nt_errstr(status)));
 193                 TALLOC_FREE(frame);
 194                 errno = EINVAL;
 195                 return -1;
 196         }
 197
 198         for (i=0; i<attribs->num_eas; i++) {
 199                 if (strcmp(attribs->eas[i].name, name) == 0) {
 200                         break;
 201                 }
 202         }
 203
 204         if (i == attribs->num_eas) {
 205                 errno = ENOATTR;
 206                 goto fail;
 207         }
 208
 209         *blob = attribs->eas[i].value;
 210         talloc_steal(mem_ctx, blob->data);
 211         result = attribs->eas[i].value.length;
 212
 213  fail:
 214         TALLOC_FREE(frame);
 215         return result;
 216 }
 217
 218 /*
 219  * Worker routine for setxattr and fsetxattr
 220  */
 221
 222 int xattr_tdb_setattr(struct db_context *db_ctx,
 223                       const struct file_id *id, const char *name,
 224                       const void *value, size_t size, int flags)
 225 {
 226         NTSTATUS status;
 227         struct db_record *rec;
 228         struct tdb_xattrs *attribs;
 229         uint32_t i;
 230         TDB_DATA data;
 231         TALLOC_CTX *frame = talloc_stackframe();
 232
 233         DEBUG(10, ("xattr_tdb_setattr called for file %s, name %s\n",
 234                    file_id_string(frame, id), name));
 235
 236         rec = xattr_tdb_lock_attrs(frame, db_ctx, id);
 237
 238         if (rec == NULL) {
 239                 DEBUG(0, ("xattr_tdb_lock_attrs failed\n"));
 240                 errno = EINVAL;
 241                 return -1;
 242         }
 243
 244         data = dbwrap_record_get_value(rec);
 245
 246         status = xattr_tdb_pull_attrs(rec, &data, &attribs);
 247
 248         if (!NT_STATUS_IS_OK(status)) {
 249                 DEBUG(10, ("xattr_tdb_fetch_attrs failed: %s\n",
 250                            nt_errstr(status)));
 251                 TALLOC_FREE(frame);
 252                 return -1;
 253         }
 254
 255         for (i=0; i<attribs->num_eas; i++) {
 256                 if (strcmp(attribs->eas[i].name, name) == 0) {
 257                         if (flags & XATTR_CREATE) {
 258                                 TALLOC_FREE(frame);
 259                                 errno = EEXIST;
 260                                 return -1;
 261                         }
 262                         break;
 263                 }
 264         }
 265
 266         if (i == attribs->num_eas) {
 267                 struct xattr_EA *tmp;
 268
 269                 if (flags & XATTR_REPLACE) {
 270                         TALLOC_FREE(frame);
 271                         errno = ENOATTR;
 272                         return -1;
 273                 }
 274
 275                 tmp = talloc_realloc(
 276                         attribs, attribs->eas, struct xattr_EA,
 277                         attribs->num_eas+ 1);
 278
 279                 if (tmp == NULL) {
 280                         DEBUG(0, ("talloc_realloc failed\n"));
 281                         TALLOC_FREE(frame);
 282                         errno = ENOMEM;
 283                         return -1;
 284                 }
 285
 286                 attribs->eas = tmp;
 287                 attribs->num_eas += 1;
 288         }
 289
 290         attribs->eas[i].name = name;
 291         attribs->eas[i].value.data = discard_const_p(uint8_t, value);
 292         attribs->eas[i].value.length = size;
 293
 294         status = xattr_tdb_save_attrs(rec, attribs);
 295
 296         TALLOC_FREE(frame);
 297
 298         if (!NT_STATUS_IS_OK(status)) {
 299                 DEBUG(1, ("save failed: %s\n", nt_errstr(status)));
 300                 return -1;
 301         }
 302
 303         return 0;
 304 }
 305
 306 /*
 307  * Worker routine for listxattr and flistxattr
 308  */
 309
 310 ssize_t xattr_tdb_listattr(struct db_context *db_ctx,
 311                            const struct file_id *id, char *list,
 312                            size_t size)
 313 {
 314         NTSTATUS status;
 315         struct tdb_xattrs *attribs;
 316         uint32_t i;
 317         size_t len = 0;
 318         TALLOC_CTX *frame = talloc_stackframe();
 319
 320         status = xattr_tdb_load_attrs(frame, db_ctx, id, &attribs);
 321
 322         if (!NT_STATUS_IS_OK(status) &&
 323             !NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND))
 324         {
 325                 DEBUG(0, ("xattr_tdb_fetch_attrs failed: %s\n",
 326                            nt_errstr(status)));
 327                 errno = EINVAL;
 328                 TALLOC_FREE(frame);
 329                 return -1;
 330         }
 331
 332         if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
 333                 TALLOC_FREE(frame);
 334                 return 0;
 335         }
 336
 337         DEBUG(10, ("xattr_tdb_listattr: Found %d xattrs\n",
 338                    attribs->num_eas));
 339
 340         for (i=0; i<attribs->num_eas; i++) {
 341                 size_t tmp;
 342
 343                 DEBUG(10, ("xattr_tdb_listattr: xattrs[i].name: %s\n",
 344                            attribs->eas[i].name));
 345
 346                 tmp = strlen(attribs->eas[i].name);
 347
 348                 /*
 349                  * Try to protect against overflow
 350                  */
 351
 352                 if (len + (tmp+1) < len) {
 353                         TALLOC_FREE(frame);
 354                         errno = EINVAL;
 355                         return -1;
 356                 }
 357
 358                 /*
 359                  * Take care of the terminating NULL
 360                  */
 361                 len += (tmp + 1);
 362         }
 363
 364         if (len > size) {
 365                 TALLOC_FREE(frame);
 366                 errno = ERANGE;
 367                 return len;
 368         }
 369
 370         len = 0;
 371
 372         for (i=0; i<attribs->num_eas; i++) {
 373                 strlcpy(list+len, attribs->eas[i].name,
 374                         size-len);
 375                 len += (strlen(attribs->eas[i].name) + 1);
 376         }
 377
 378         TALLOC_FREE(frame);
 379         return len;
 380 }
 381
 382 /*
 383  * Worker routine for removexattr and fremovexattr
 384  */
 385
 386 int xattr_tdb_removeattr(struct db_context *db_ctx,
 387                          const struct file_id *id, const char *name)
 388 {
 389         NTSTATUS status;
 390         struct db_record *rec;
 391         struct tdb_xattrs *attribs;
 392         uint32_t i;
 393         TDB_DATA value;
 394
 395         rec = xattr_tdb_lock_attrs(talloc_tos(), db_ctx, id);
 396
 397         if (rec == NULL) {
 398                 DEBUG(0, ("xattr_tdb_lock_attrs failed\n"));
 399                 errno = EINVAL;
 400                 return -1;
 401         }
 402
 403         value = dbwrap_record_get_value(rec);
 404
 405         status = xattr_tdb_pull_attrs(rec, &value, &attribs);
 406
 407         if (!NT_STATUS_IS_OK(status)) {
 408                 DEBUG(10, ("xattr_tdb_fetch_attrs failed: %s\n",
 409                            nt_errstr(status)));
 410                 TALLOC_FREE(rec);
 411                 return -1;
 412         }
 413
 414         for (i=0; i<attribs->num_eas; i++) {
 415                 if (strcmp(attribs->eas[i].name, name) == 0) {
 416                         break;
 417                 }
 418         }
 419
 420         if (i == attribs->num_eas) {
 421                 TALLOC_FREE(rec);
 422                 errno = ENOATTR;
 423                 return -1;
 424         }
 425
 426         attribs->eas[i] =
 427                 attribs->eas[attribs->num_eas-1];
 428         attribs->num_eas -= 1;
 429
 430         if (attribs->num_eas == 0) {
 431                 dbwrap_record_delete(rec);
 432                 TALLOC_FREE(rec);
 433                 return 0;
 434         }
 435
 436         status = xattr_tdb_save_attrs(rec, attribs);
 437
 438         TALLOC_FREE(rec);
 439
 440         if (!NT_STATUS_IS_OK(status)) {
 441                 DEBUG(1, ("save failed: %s\n", nt_errstr(status)));
 442                 return -1;
 443         }
 444
 445         return 0;
 446 }
 447
 448 /*
 449  * Worker routine for unlink and rmdir
 450  */
 451
 452 void xattr_tdb_remove_all_attrs(struct db_context *db_ctx,
 453                                const struct file_id *id)
 454 {
 455         struct db_record *rec;
 456         rec = xattr_tdb_lock_attrs(talloc_tos(), db_ctx, id);
 457
 458         /*
 459          * If rec == NULL there's not much we can do about it
 460          */
 461
 462         if (rec != NULL) {
 463                 dbwrap_record_delete(rec);
 464                 TALLOC_FREE(rec);
 465         }
 466 }