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