source3/lib/idmap_cache.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    ID Mapping Cache
   4
   5    Copyright (C) Volker Lendecke        2008
   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 #include "includes.h"
  21 #include "idmap_cache.h"
  22 #include "../libcli/security/security.h"
  23 #include "../librpc/gen_ndr/idmap.h"
  24
  25 /**
  26  * Find a sid2xid mapping
  27  * @param[in] sid               the sid to map
  28  * @param[out] id               where to put the result
  29  * @param[out] expired          is the cache entry expired?
  30  * @retval Was anything in the cache at all?
  31  *
  32  * If id->id == -1 this was a negative mapping.
  33  */
  34
  35 bool idmap_cache_find_sid2unixid(const struct dom_sid *sid, struct unixid *id,
  36                                  bool *expired)
  37 {
  38         fstring sidstr;
  39         char *key;
  40         char *value = NULL;
  41         char *endptr;
  42         time_t timeout;
  43         bool ret;
  44         struct unixid tmp_id;
  45
  46         key = talloc_asprintf(talloc_tos(), "IDMAP/SID2XID/%s",
  47                               sid_to_fstring(sidstr, sid));
  48         if (key == NULL) {
  49                 return false;
  50         }
  51         ret = gencache_get(key, &value, &timeout);
  52         if (!ret) {
  53                 goto done;
  54         }
  55
  56         DEBUG(10, ("Parsing value for key [%s]: value=[%s]\n", key, value));
  57
  58         if (value[0] == '\0') {
  59                 DEBUG(0, ("Failed to parse value for key [%s]: "
  60                           "value is empty\n", key));
  61                 ret = false;
  62                 goto done;
  63         }
  64
  65         tmp_id.id = strtol(value, &endptr, 10);
  66
  67         if ((value == endptr) && (tmp_id.id == 0)) {
  68                 DEBUG(0, ("Failed to parse value for key [%s]: value[%s] does "
  69                           "not start with a number\n", key, value));
  70                 ret = false;
  71                 goto done;
  72         }
  73
  74         DEBUG(10, ("Parsing value for key [%s]: id=[%llu], endptr=[%s]\n",
  75                    key, (unsigned long long)tmp_id.id, endptr));
  76
  77         ret = (*endptr == ':');
  78         if (ret) {
  79                 switch (endptr[1]) {
  80                 case 'U':
  81                         tmp_id.type = ID_TYPE_UID;
  82                         break;
  83
  84                 case 'G':
  85                         tmp_id.type = ID_TYPE_GID;
  86                         break;
  87
  88                 case 'B':
  89                         tmp_id.type = ID_TYPE_BOTH;
  90                         break;
  91
  92                 case 'N':
  93                         tmp_id.type = ID_TYPE_NOT_SPECIFIED;
  94                         break;
  95
  96                 case '\0':
  97                         DEBUG(0, ("FAILED to parse value for key [%s] "
  98                                   "(id=[%llu], endptr=[%s]): "
  99                                   "no type character after colon\n",
 100                                   key, (unsigned long long)tmp_id.id, endptr));
 101                         ret = false;
 102                         goto done;
 103                 default:
 104                         DEBUG(0, ("FAILED to parse value for key [%s] "
 105                                   "(id=[%llu], endptr=[%s]): "
 106                                   "illegal type character '%c'\n",
 107                                   key, (unsigned long long)tmp_id.id, endptr,
 108                                   endptr[1]));
 109                         ret = false;
 110                         goto done;
 111                 }
 112                 if (endptr[2] != '\0') {
 113                         DEBUG(0, ("FAILED to parse value for key [%s] "
 114                                   "(id=[%llu], endptr=[%s]): "
 115                                   "more than 1 type character after colon\n",
 116                                   key, (unsigned long long)tmp_id.id, endptr));
 117                         ret = false;
 118                         goto done;
 119                 }
 120
 121                 *id = tmp_id;
 122                 *expired = (timeout <= time(NULL));
 123         } else {
 124                 DEBUG(0, ("FAILED to parse value for key [%s] (value=[%s]): "
 125                           "colon missing after id=[%llu]\n",
 126                           key, value, (unsigned long long)tmp_id.id));
 127         }
 128
 129 done:
 130         TALLOC_FREE(key);
 131         SAFE_FREE(value);
 132         return ret;
 133 }
 134
 135 /**
 136  * Find a sid2uid mapping
 137  * @param[in] sid               the sid to map
 138  * @param[out] puid             where to put the result
 139  * @param[out] expired          is the cache entry expired?
 140  * @retval Was anything in the cache at all?
 141  *
 142  * If *puid == -1 this was a negative mapping.
 143  */
 144
 145 bool idmap_cache_find_sid2uid(const struct dom_sid *sid, uid_t *puid,
 146                               bool *expired)
 147 {
 148         bool ret;
 149         struct unixid id;
 150         ret = idmap_cache_find_sid2unixid(sid, &id, expired);
 151         if (!ret) {
 152                 return false;
 153         }
 154
 155         if (id.type == ID_TYPE_BOTH || id.type == ID_TYPE_UID) {
 156                 *puid = id.id;
 157         } else {
 158                 *puid = -1;
 159         }
 160         return true;
 161 }
 162
 163 /**
 164  * Find a sid2gid mapping
 165  * @param[in] sid               the sid to map
 166  * @param[out] pgid             where to put the result
 167  * @param[out] expired          is the cache entry expired?
 168  * @retval Was anything in the cache at all?
 169  *
 170  * If *pgid == -1 this was a negative mapping.
 171  */
 172
 173 bool idmap_cache_find_sid2gid(const struct dom_sid *sid, gid_t *pgid,
 174                               bool *expired)
 175 {
 176         bool ret;
 177         struct unixid id;
 178         ret = idmap_cache_find_sid2unixid(sid, &id, expired);
 179         if (!ret) {
 180                 return false;
 181         }
 182
 183         if (id.type == ID_TYPE_BOTH || id.type == ID_TYPE_GID) {
 184                 *pgid = id.id;
 185         } else {
 186                 *pgid = -1;
 187         }
 188         return true;
 189 }
 190
 191 /**
 192  * Find a uid2sid mapping
 193  * @param[in] uid               the uid to map
 194  * @param[out] sid              where to put the result
 195  * @param[out] expired          is the cache entry expired?
 196  * @retval Was anything in the cache at all?
 197  *
 198  * If "is_null_sid(sid)", this was a negative mapping.
 199  */
 200
 201 bool idmap_cache_find_uid2sid(uid_t uid, struct dom_sid *sid, bool *expired)
 202 {
 203         char *key;
 204         char *value;
 205         time_t timeout;
 206         bool ret = true;
 207
 208         key = talloc_asprintf(talloc_tos(), "IDMAP/UID2SID/%d", (int)uid);
 209         if (key == NULL) {
 210                 return false;
 211         }
 212         ret = gencache_get(key, &value, &timeout);
 213         TALLOC_FREE(key);
 214         if (!ret) {
 215                 return false;
 216         }
 217         ZERO_STRUCTP(sid);
 218         if (value[0] != '-') {
 219                 ret = string_to_sid(sid, value);
 220         }
 221         SAFE_FREE(value);
 222         if (ret) {
 223                 *expired = (timeout <= time(NULL));
 224         }
 225         return ret;
 226 }
 227
 228 /**
 229  * Find a gid2sid mapping
 230  * @param[in] gid               the gid to map
 231  * @param[out] sid              where to put the result
 232  * @param[out] expired          is the cache entry expired?
 233  * @retval Was anything in the cache at all?
 234  *
 235  * If "is_null_sid(sid)", this was a negative mapping.
 236  */
 237
 238 bool idmap_cache_find_gid2sid(gid_t gid, struct dom_sid *sid, bool *expired)
 239 {
 240         char *key;
 241         char *value;
 242         time_t timeout;
 243         bool ret = true;
 244
 245         key = talloc_asprintf(talloc_tos(), "IDMAP/GID2SID/%d", (int)gid);
 246         if (key == NULL) {
 247                 return false;
 248         }
 249         ret = gencache_get(key, &value, &timeout);
 250         TALLOC_FREE(key);
 251         if (!ret) {
 252                 return false;
 253         }
 254         ZERO_STRUCTP(sid);
 255         if (value[0] != '-') {
 256                 ret = string_to_sid(sid, value);
 257         }
 258         SAFE_FREE(value);
 259         if (ret) {
 260                 *expired = (timeout <= time(NULL));
 261         }
 262         return ret;
 263 }
 264
 265 /**
 266  * Store a mapping in the idmap cache
 267  * @param[in] sid               the sid to map
 268  * @param[in] gid               the gid to map
 269  *
 270  * If both parameters are valid values, then a positive mapping in both
 271  * directions is stored. If "is_null_sid(sid)" is true, then this will be a
 272  * negative mapping of gid, we want to cache that for this gid we could not
 273  * find anything. Likewise if "gid==-1", then we want to cache that we did not
 274  * find a mapping for the sid passed here.
 275  */
 276
 277 void idmap_cache_set_sid2unixid(const struct dom_sid *sid, struct unixid *unix_id)
 278 {
 279         time_t now = time(NULL);
 280         time_t timeout;
 281         fstring sidstr, key, value;
 282
 283         if (!is_null_sid(sid)) {
 284                 fstr_sprintf(key, "IDMAP/SID2XID/%s",
 285                              sid_to_fstring(sidstr, sid));
 286                 switch (unix_id->type) {
 287                 case ID_TYPE_UID:
 288                         fstr_sprintf(value, "%d:U", (int)unix_id->id);
 289                         break;
 290                 case ID_TYPE_GID:
 291                         fstr_sprintf(value, "%d:G", (int)unix_id->id);
 292                         break;
 293                 case ID_TYPE_BOTH:
 294                         fstr_sprintf(value, "%d:B", (int)unix_id->id);
 295                         break;
 296                 case ID_TYPE_NOT_SPECIFIED:
 297                         fstr_sprintf(value, "%d:N", (int)unix_id->id);
 298                         break;
 299                 default:
 300                         return;
 301                 }
 302                 timeout = (unix_id->id == -1)
 303                         ? lp_idmap_negative_cache_time()
 304                         : lp_idmap_cache_time();
 305                 gencache_set(key, value, now + timeout);
 306         }
 307         if (unix_id->id != -1) {
 308                 if (is_null_sid(sid)) {
 309                         /* negative gid mapping */
 310                         fstrcpy(value, "-");
 311                         timeout = lp_idmap_negative_cache_time();
 312                 }
 313                 else {
 314                         sid_to_fstring(value, sid);
 315                         timeout = lp_idmap_cache_time();
 316                 }
 317                 switch (unix_id->type) {
 318                 case ID_TYPE_BOTH:
 319                         fstr_sprintf(key, "IDMAP/UID2SID/%d", (int)unix_id->id);
 320                         gencache_set(key, value, now + timeout);
 321                         fstr_sprintf(key, "IDMAP/GID2SID/%d", (int)unix_id->id);
 322                         gencache_set(key, value, now + timeout);
 323                         return;
 324
 325                 case ID_TYPE_UID:
 326                         fstr_sprintf(key, "IDMAP/UID2SID/%d", (int)unix_id->id);
 327                         break;
 328
 329                 case ID_TYPE_GID:
 330                         fstr_sprintf(key, "IDMAP/GID2SID/%d", (int)unix_id->id);
 331                         break;
 332
 333                 default:
 334                         return;
 335                 }
 336                 gencache_set(key, value, now + timeout);
 337         }
 338 }
 339
 340 /**
 341  * Store a mapping in the idmap cache
 342  * @param[in] sid               the sid to map
 343  * @param[in] uid               the uid to map
 344  *
 345  * If both parameters are valid values, then a positive mapping in both
 346  * directions is stored. If "is_null_sid(sid)" is true, then this will be a
 347  * negative mapping of uid, we want to cache that for this uid we could not
 348  * find anything. Likewise if "uid==-1", then we want to cache that we did not
 349  * find a mapping for the sid passed here.
 350  */
 351
 352 void idmap_cache_set_sid2uid(const struct dom_sid *sid, uid_t uid)
 353 {
 354         struct unixid id;
 355         id.type = ID_TYPE_UID;
 356         id.id = uid;
 357
 358         if (uid == -1) {
 359                 uid_t tmp_gid;
 360                 bool expired;
 361                 /* If we were asked to invalidate this SID -> UID
 362                  * mapping, it was because we found out that this was
 363                  * not a UID at all.  Do not overwrite a valid GID or
 364                  * BOTH mapping */
 365                 if (idmap_cache_find_sid2gid(sid, &tmp_gid, &expired)) {
 366                         if (!expired) {
 367                                 return;
 368                         }
 369                 }
 370         }
 371
 372         idmap_cache_set_sid2unixid(sid, &id);
 373         return;
 374 }
 375
 376 /**
 377  * Store a mapping in the idmap cache
 378  * @param[in] sid               the sid to map
 379  * @param[in] gid               the gid to map
 380  *
 381  * If both parameters are valid values, then a positive mapping in both
 382  * directions is stored. If "is_null_sid(sid)" is true, then this will be a
 383  * negative mapping of gid, we want to cache that for this gid we could not
 384  * find anything. Likewise if "gid==-1", then we want to cache that we did not
 385  * find a mapping for the sid passed here.
 386  */
 387
 388 void idmap_cache_set_sid2gid(const struct dom_sid *sid, gid_t gid)
 389 {
 390         struct unixid id;
 391         id.type = ID_TYPE_GID;
 392         id.id = gid;
 393
 394         if (gid == -1) {
 395                 uid_t tmp_uid;
 396                 bool expired;
 397                 /* If we were asked to invalidate this SID -> GID
 398                  * mapping, it was because we found out that this was
 399                  * not a GID at all.  Do not overwrite a valid UID or
 400                  * BOTH mapping */
 401                 if (idmap_cache_find_sid2uid(sid, &tmp_uid, &expired)) {
 402                         if (!expired) {
 403                                 return;
 404                         }
 405                 }
 406         }
 407
 408         idmap_cache_set_sid2unixid(sid, &id);
 409         return;
 410 }
 411
 412 static char* key_xid2sid_str(TALLOC_CTX* mem_ctx, char t, const char* id) {
 413         return talloc_asprintf(mem_ctx, "IDMAP/%cID2SID/%s", t, id);
 414 }
 415
 416 static char* key_xid2sid(TALLOC_CTX* mem_ctx, char t, int id) {
 417         char str[32];
 418         snprintf(str, sizeof(str), "%d", id);
 419         return key_xid2sid_str(mem_ctx, t, str);
 420 }
 421
 422 static char* key_sid2xid_str(TALLOC_CTX* mem_ctx, const char* id) {
 423         return talloc_asprintf(mem_ctx, "IDMAP/SID2XID/%s", id);
 424 }
 425
 426 static bool idmap_cache_del_xid(char t, int xid)
 427 {
 428         TALLOC_CTX* mem_ctx = talloc_stackframe();
 429         const char* key = key_xid2sid(mem_ctx, t, xid);
 430         char* sid_str = NULL;
 431         time_t timeout;
 432         bool ret = true;
 433
 434         if (!gencache_get(key, &sid_str, &timeout)) {
 435                 DEBUG(3, ("no entry: %s\n", key));
 436                 ret = false;
 437                 goto done;
 438         }
 439
 440         if (sid_str[0] != '-') {
 441                 const char* sid_key = key_sid2xid_str(mem_ctx, sid_str);
 442                 if (!gencache_del(sid_key)) {
 443                         DEBUG(2, ("failed to delete: %s\n", sid_key));
 444                         ret = false;
 445                 } else {
 446                         DEBUG(5, ("delete: %s\n", sid_key));
 447                 }
 448
 449         }
 450
 451         if (!gencache_del(key)) {
 452                 DEBUG(1, ("failed to delete: %s\n", key));
 453                 ret = false;
 454         } else {
 455                 DEBUG(5, ("delete: %s\n", key));
 456         }
 457
 458 done:
 459         talloc_free(mem_ctx);
 460         return ret;
 461 }
 462
 463 bool idmap_cache_del_uid(uid_t uid) {
 464         return idmap_cache_del_xid('U', uid);
 465 }
 466
 467 bool idmap_cache_del_gid(gid_t gid) {
 468         return idmap_cache_del_xid('G', gid);
 469 }
 470
 471 bool idmap_cache_del_sid(const struct dom_sid *sid)
 472 {
 473         TALLOC_CTX* mem_ctx = talloc_stackframe();
 474         bool ret = true;
 475         bool expired;
 476         struct unixid id;
 477         const char *sid_key;
 478
 479         if (!idmap_cache_find_sid2unixid(sid, &id, &expired)) {
 480                 ret = false;
 481                 goto done;
 482         }
 483
 484         if (id.id != -1) {
 485                 switch (id.type) {
 486                 case ID_TYPE_BOTH:
 487                         idmap_cache_del_xid('U', id.id);
 488                         idmap_cache_del_xid('G', id.id);
 489                         break;
 490                 case ID_TYPE_UID:
 491                         idmap_cache_del_xid('U', id.id);
 492                         break;
 493                 case ID_TYPE_GID:
 494                         idmap_cache_del_xid('G', id.id);
 495                         break;
 496                 default:
 497                         break;
 498                 }
 499         }
 500
 501         sid_key = key_sid2xid_str(mem_ctx, dom_sid_string(mem_ctx, sid));
 502         if (sid_key == NULL) {
 503                 return false;
 504         }
 505         /* If the mapping was symmetric, then this should fail */
 506         gencache_del(sid_key);
 507 done:
 508         talloc_free(mem_ctx);
 509         return ret;
 510 }