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, talloc_tos(), &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         TALLOC_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         fstring key;
 204         char *value;
 205         time_t timeout;
 206         bool ret = true;
 207
 208         fstr_sprintf(key, "IDMAP/UID2SID/%d", (int)uid);
 209
 210         ret = gencache_get(key, talloc_tos(), &value, &timeout);
 211         if (!ret) {
 212                 return false;
 213         }
 214         ZERO_STRUCTP(sid);
 215         if (value[0] != '-') {
 216                 ret = string_to_sid(sid, value);
 217         }
 218         TALLOC_FREE(value);
 219         if (ret) {
 220                 *expired = (timeout <= time(NULL));
 221         }
 222         return ret;
 223 }
 224
 225 /**
 226  * Find a gid2sid mapping
 227  * @param[in] gid               the gid to map
 228  * @param[out] sid              where to put the result
 229  * @param[out] expired          is the cache entry expired?
 230  * @retval Was anything in the cache at all?
 231  *
 232  * If "is_null_sid(sid)", this was a negative mapping.
 233  */
 234
 235 bool idmap_cache_find_gid2sid(gid_t gid, struct dom_sid *sid, bool *expired)
 236 {
 237         fstring key;
 238         char *value;
 239         time_t timeout;
 240         bool ret = true;
 241
 242         fstr_sprintf(key, "IDMAP/GID2SID/%d", (int)gid);
 243
 244         ret = gencache_get(key, talloc_tos(), &value, &timeout);
 245         if (!ret) {
 246                 return false;
 247         }
 248         ZERO_STRUCTP(sid);
 249         if (value[0] != '-') {
 250                 ret = string_to_sid(sid, value);
 251         }
 252         TALLOC_FREE(value);
 253         if (ret) {
 254                 *expired = (timeout <= time(NULL));
 255         }
 256         return ret;
 257 }
 258
 259 /**
 260  * Store a mapping in the idmap cache
 261  * @param[in] sid               the sid to map
 262  * @param[in] gid               the gid to map
 263  *
 264  * If both parameters are valid values, then a positive mapping in both
 265  * directions is stored. If "is_null_sid(sid)" is true, then this will be a
 266  * negative mapping of gid, we want to cache that for this gid we could not
 267  * find anything. Likewise if "gid==-1", then we want to cache that we did not
 268  * find a mapping for the sid passed here.
 269  */
 270
 271 void idmap_cache_set_sid2unixid(const struct dom_sid *sid, struct unixid *unix_id)
 272 {
 273         time_t now = time(NULL);
 274         time_t timeout;
 275         fstring sidstr, key, value;
 276
 277         if (!is_null_sid(sid)) {
 278                 fstr_sprintf(key, "IDMAP/SID2XID/%s",
 279                              sid_to_fstring(sidstr, sid));
 280                 switch (unix_id->type) {
 281                 case ID_TYPE_UID:
 282                         fstr_sprintf(value, "%d:U", (int)unix_id->id);
 283                         break;
 284                 case ID_TYPE_GID:
 285                         fstr_sprintf(value, "%d:G", (int)unix_id->id);
 286                         break;
 287                 case ID_TYPE_BOTH:
 288                         fstr_sprintf(value, "%d:B", (int)unix_id->id);
 289                         break;
 290                 case ID_TYPE_NOT_SPECIFIED:
 291                         fstr_sprintf(value, "%d:N", (int)unix_id->id);
 292                         break;
 293                 default:
 294                         return;
 295                 }
 296                 timeout = (unix_id->id == -1)
 297                         ? lp_idmap_negative_cache_time()
 298                         : lp_idmap_cache_time();
 299                 gencache_set(key, value, now + timeout);
 300         }
 301         if (unix_id->id != -1) {
 302                 if (is_null_sid(sid)) {
 303                         /* negative gid mapping */
 304                         fstrcpy(value, "-");
 305                         timeout = lp_idmap_negative_cache_time();
 306                 }
 307                 else {
 308                         sid_to_fstring(value, sid);
 309                         timeout = lp_idmap_cache_time();
 310                 }
 311                 switch (unix_id->type) {
 312                 case ID_TYPE_BOTH:
 313                         fstr_sprintf(key, "IDMAP/UID2SID/%d", (int)unix_id->id);
 314                         gencache_set(key, value, now + timeout);
 315                         fstr_sprintf(key, "IDMAP/GID2SID/%d", (int)unix_id->id);
 316                         gencache_set(key, value, now + timeout);
 317                         return;
 318
 319                 case ID_TYPE_UID:
 320                         fstr_sprintf(key, "IDMAP/UID2SID/%d", (int)unix_id->id);
 321                         break;
 322
 323                 case ID_TYPE_GID:
 324                         fstr_sprintf(key, "IDMAP/GID2SID/%d", (int)unix_id->id);
 325                         break;
 326
 327                 default:
 328                         return;
 329                 }
 330                 gencache_set(key, value, now + timeout);
 331         }
 332 }
 333
 334 /**
 335  * Store a mapping in the idmap cache
 336  * @param[in] sid               the sid to map
 337  * @param[in] uid               the uid to map
 338  *
 339  * If both parameters are valid values, then a positive mapping in both
 340  * directions is stored. If "is_null_sid(sid)" is true, then this will be a
 341  * negative mapping of uid, we want to cache that for this uid we could not
 342  * find anything. Likewise if "uid==-1", then we want to cache that we did not
 343  * find a mapping for the sid passed here.
 344  */
 345
 346 void idmap_cache_set_sid2uid(const struct dom_sid *sid, uid_t uid)
 347 {
 348         struct unixid id;
 349         id.type = ID_TYPE_UID;
 350         id.id = uid;
 351
 352         if (uid == -1) {
 353                 uid_t tmp_gid;
 354                 bool expired;
 355                 /* If we were asked to invalidate this SID -> UID
 356                  * mapping, it was because we found out that this was
 357                  * not a UID at all.  Do not overwrite a valid GID or
 358                  * BOTH mapping */
 359                 if (idmap_cache_find_sid2gid(sid, &tmp_gid, &expired)) {
 360                         if (!expired) {
 361                                 return;
 362                         }
 363                 }
 364         }
 365
 366         idmap_cache_set_sid2unixid(sid, &id);
 367         return;
 368 }
 369
 370 /**
 371  * Store a mapping in the idmap cache
 372  * @param[in] sid               the sid to map
 373  * @param[in] gid               the gid to map
 374  *
 375  * If both parameters are valid values, then a positive mapping in both
 376  * directions is stored. If "is_null_sid(sid)" is true, then this will be a
 377  * negative mapping of gid, we want to cache that for this gid we could not
 378  * find anything. Likewise if "gid==-1", then we want to cache that we did not
 379  * find a mapping for the sid passed here.
 380  */
 381
 382 void idmap_cache_set_sid2gid(const struct dom_sid *sid, gid_t gid)
 383 {
 384         struct unixid id;
 385         id.type = ID_TYPE_GID;
 386         id.id = gid;
 387
 388         if (gid == -1) {
 389                 uid_t tmp_uid;
 390                 bool expired;
 391                 /* If we were asked to invalidate this SID -> GID
 392                  * mapping, it was because we found out that this was
 393                  * not a GID at all.  Do not overwrite a valid UID or
 394                  * BOTH mapping */
 395                 if (idmap_cache_find_sid2uid(sid, &tmp_uid, &expired)) {
 396                         if (!expired) {
 397                                 return;
 398                         }
 399                 }
 400         }
 401
 402         idmap_cache_set_sid2unixid(sid, &id);
 403         return;
 404 }
 405
 406 static char* key_xid2sid_str(TALLOC_CTX* mem_ctx, char t, const char* id) {
 407         return talloc_asprintf(mem_ctx, "IDMAP/%cID2SID/%s", t, id);
 408 }
 409
 410 static char* key_xid2sid(TALLOC_CTX* mem_ctx, char t, int id) {
 411         char str[32];
 412         snprintf(str, sizeof(str), "%d", id);
 413         return key_xid2sid_str(mem_ctx, t, str);
 414 }
 415
 416 static char* key_sid2xid_str(TALLOC_CTX* mem_ctx, const char* id) {
 417         return talloc_asprintf(mem_ctx, "IDMAP/SID2XID/%s", id);
 418 }
 419
 420 static bool idmap_cache_del_xid(char t, int xid)
 421 {
 422         TALLOC_CTX* mem_ctx = talloc_stackframe();
 423         const char* key = key_xid2sid(mem_ctx, t, xid);
 424         char* sid_str = NULL;
 425         time_t timeout;
 426         bool ret = true;
 427
 428         if (!gencache_get(key, mem_ctx, &sid_str, &timeout)) {
 429                 DEBUG(3, ("no entry: %s\n", key));
 430                 ret = false;
 431                 goto done;
 432         }
 433
 434         if (sid_str[0] != '-') {
 435                 const char* sid_key = key_sid2xid_str(mem_ctx, sid_str);
 436                 if (!gencache_del(sid_key)) {
 437                         DEBUG(2, ("failed to delete: %s\n", sid_key));
 438                         ret = false;
 439                 } else {
 440                         DEBUG(5, ("delete: %s\n", sid_key));
 441                 }
 442
 443         }
 444
 445         if (!gencache_del(key)) {
 446                 DEBUG(1, ("failed to delete: %s\n", key));
 447                 ret = false;
 448         } else {
 449                 DEBUG(5, ("delete: %s\n", key));
 450         }
 451
 452 done:
 453         talloc_free(mem_ctx);
 454         return ret;
 455 }
 456
 457 bool idmap_cache_del_uid(uid_t uid) {
 458         return idmap_cache_del_xid('U', uid);
 459 }
 460
 461 bool idmap_cache_del_gid(gid_t gid) {
 462         return idmap_cache_del_xid('G', gid);
 463 }
 464
 465 bool idmap_cache_del_sid(const struct dom_sid *sid)
 466 {
 467         TALLOC_CTX* mem_ctx = talloc_stackframe();
 468         bool ret = true;
 469         bool expired;
 470         struct unixid id;
 471         const char *sid_key;
 472
 473         if (!idmap_cache_find_sid2unixid(sid, &id, &expired)) {
 474                 ret = false;
 475                 goto done;
 476         }
 477
 478         if (id.id != -1) {
 479                 switch (id.type) {
 480                 case ID_TYPE_BOTH:
 481                         idmap_cache_del_xid('U', id.id);
 482                         idmap_cache_del_xid('G', id.id);
 483                         break;
 484                 case ID_TYPE_UID:
 485                         idmap_cache_del_xid('U', id.id);
 486                         break;
 487                 case ID_TYPE_GID:
 488                         idmap_cache_del_xid('G', id.id);
 489                         break;
 490                 default:
 491                         break;
 492                 }
 493         }
 494
 495         sid_key = key_sid2xid_str(mem_ctx, dom_sid_string(mem_ctx, sid));
 496         if (sid_key == NULL) {
 497                 return false;
 498         }
 499         /* If the mapping was symmetric, then this should fail */
 500         gencache_del(sid_key);
 501 done:
 502         talloc_free(mem_ctx);
 503         return ret;
 504 }