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 struct idmap_cache_xid2sid_state {
 192         struct dom_sid *sid;
 193         bool *expired;
 194         bool ret;
 195 };
 196
 197 static void idmap_cache_xid2sid_parser(time_t timeout, DATA_BLOB blob,
 198                                        void *private_data)
 199 {
 200         struct idmap_cache_xid2sid_state *state =
 201                 (struct idmap_cache_xid2sid_state *)private_data;
 202         char *value;
 203
 204         ZERO_STRUCTP(state->sid);
 205         state->ret = false;
 206
 207         if ((blob.length == 0) || (blob.data[blob.length-1] != 0)) {
 208                 /*
 209                  * Not a string, can't be a valid mapping
 210                  */
 211                 return;
 212         }
 213
 214         value = (char *)blob.data;
 215
 216         if (value[0] != '-') {
 217                 state->ret = string_to_sid(state->sid, value);
 218         }
 219         if (state->ret) {
 220                 *state->expired = (timeout <= time(NULL));
 221         }
 222 }
 223
 224 /**
 225  * Find a uid2sid mapping
 226  * @param[in] uid               the uid 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_uid2sid(uid_t uid, struct dom_sid *sid, bool *expired)
 235 {
 236         fstring key;
 237         struct idmap_cache_xid2sid_state state;
 238
 239         fstr_sprintf(key, "IDMAP/UID2SID/%d", (int)uid);
 240
 241         state.sid = sid;
 242         state.expired = expired;
 243         state.ret = false;
 244
 245         gencache_parse(key, idmap_cache_xid2sid_parser, &state);
 246         return state.ret;
 247 }
 248
 249 /**
 250  * Find a gid2sid mapping
 251  * @param[in] gid               the gid to map
 252  * @param[out] sid              where to put the result
 253  * @param[out] expired          is the cache entry expired?
 254  * @retval Was anything in the cache at all?
 255  *
 256  * If "is_null_sid(sid)", this was a negative mapping.
 257  */
 258
 259 bool idmap_cache_find_gid2sid(gid_t gid, struct dom_sid *sid, bool *expired)
 260 {
 261         fstring key;
 262         struct idmap_cache_xid2sid_state state;
 263
 264         fstr_sprintf(key, "IDMAP/GID2SID/%d", (int)gid);
 265
 266         state.sid = sid;
 267         state.expired = expired;
 268         state.ret = false;
 269
 270         gencache_parse(key, idmap_cache_xid2sid_parser, &state);
 271         return state.ret;
 272 }
 273
 274 /**
 275  * Store a mapping in the idmap cache
 276  * @param[in] sid               the sid to map
 277  * @param[in] gid               the gid to map
 278  *
 279  * If both parameters are valid values, then a positive mapping in both
 280  * directions is stored. If "is_null_sid(sid)" is true, then this will be a
 281  * negative mapping of gid, we want to cache that for this gid we could not
 282  * find anything. Likewise if "gid==-1", then we want to cache that we did not
 283  * find a mapping for the sid passed here.
 284  */
 285
 286 void idmap_cache_set_sid2unixid(const struct dom_sid *sid, struct unixid *unix_id)
 287 {
 288         time_t now = time(NULL);
 289         time_t timeout;
 290         fstring sidstr, key, value;
 291
 292         if (!is_null_sid(sid)) {
 293                 fstr_sprintf(key, "IDMAP/SID2XID/%s",
 294                              sid_to_fstring(sidstr, sid));
 295                 switch (unix_id->type) {
 296                 case ID_TYPE_UID:
 297                         fstr_sprintf(value, "%d:U", (int)unix_id->id);
 298                         break;
 299                 case ID_TYPE_GID:
 300                         fstr_sprintf(value, "%d:G", (int)unix_id->id);
 301                         break;
 302                 case ID_TYPE_BOTH:
 303                         fstr_sprintf(value, "%d:B", (int)unix_id->id);
 304                         break;
 305                 case ID_TYPE_NOT_SPECIFIED:
 306                         fstr_sprintf(value, "%d:N", (int)unix_id->id);
 307                         break;
 308                 default:
 309                         return;
 310                 }
 311                 timeout = (unix_id->id == -1)
 312                         ? lp_idmap_negative_cache_time()
 313                         : lp_idmap_cache_time();
 314                 gencache_set(key, value, now + timeout);
 315         }
 316         if (unix_id->id != -1) {
 317                 if (is_null_sid(sid)) {
 318                         /* negative gid mapping */
 319                         fstrcpy(value, "-");
 320                         timeout = lp_idmap_negative_cache_time();
 321                 }
 322                 else {
 323                         sid_to_fstring(value, sid);
 324                         timeout = lp_idmap_cache_time();
 325                 }
 326                 switch (unix_id->type) {
 327                 case ID_TYPE_BOTH:
 328                         fstr_sprintf(key, "IDMAP/UID2SID/%d", (int)unix_id->id);
 329                         gencache_set(key, value, now + timeout);
 330                         fstr_sprintf(key, "IDMAP/GID2SID/%d", (int)unix_id->id);
 331                         gencache_set(key, value, now + timeout);
 332                         return;
 333
 334                 case ID_TYPE_UID:
 335                         fstr_sprintf(key, "IDMAP/UID2SID/%d", (int)unix_id->id);
 336                         break;
 337
 338                 case ID_TYPE_GID:
 339                         fstr_sprintf(key, "IDMAP/GID2SID/%d", (int)unix_id->id);
 340                         break;
 341
 342                 default:
 343                         return;
 344                 }
 345                 gencache_set(key, value, now + timeout);
 346         }
 347 }
 348
 349 /**
 350  * Store a mapping in the idmap cache
 351  * @param[in] sid               the sid to map
 352  * @param[in] uid               the uid to map
 353  *
 354  * If both parameters are valid values, then a positive mapping in both
 355  * directions is stored. If "is_null_sid(sid)" is true, then this will be a
 356  * negative mapping of uid, we want to cache that for this uid we could not
 357  * find anything. Likewise if "uid==-1", then we want to cache that we did not
 358  * find a mapping for the sid passed here.
 359  */
 360
 361 void idmap_cache_set_sid2uid(const struct dom_sid *sid, uid_t uid)
 362 {
 363         struct unixid id;
 364         id.type = ID_TYPE_UID;
 365         id.id = uid;
 366
 367         if (uid == -1) {
 368                 uid_t tmp_gid;
 369                 bool expired;
 370                 /* If we were asked to invalidate this SID -> UID
 371                  * mapping, it was because we found out that this was
 372                  * not a UID at all.  Do not overwrite a valid GID or
 373                  * BOTH mapping */
 374                 if (idmap_cache_find_sid2gid(sid, &tmp_gid, &expired)) {
 375                         if (!expired) {
 376                                 return;
 377                         }
 378                 }
 379         }
 380
 381         idmap_cache_set_sid2unixid(sid, &id);
 382         return;
 383 }
 384
 385 /**
 386  * Store a mapping in the idmap cache
 387  * @param[in] sid               the sid to map
 388  * @param[in] gid               the gid to map
 389  *
 390  * If both parameters are valid values, then a positive mapping in both
 391  * directions is stored. If "is_null_sid(sid)" is true, then this will be a
 392  * negative mapping of gid, we want to cache that for this gid we could not
 393  * find anything. Likewise if "gid==-1", then we want to cache that we did not
 394  * find a mapping for the sid passed here.
 395  */
 396
 397 void idmap_cache_set_sid2gid(const struct dom_sid *sid, gid_t gid)
 398 {
 399         struct unixid id;
 400         id.type = ID_TYPE_GID;
 401         id.id = gid;
 402
 403         if (gid == -1) {
 404                 uid_t tmp_uid;
 405                 bool expired;
 406                 /* If we were asked to invalidate this SID -> GID
 407                  * mapping, it was because we found out that this was
 408                  * not a GID at all.  Do not overwrite a valid UID or
 409                  * BOTH mapping */
 410                 if (idmap_cache_find_sid2uid(sid, &tmp_uid, &expired)) {
 411                         if (!expired) {
 412                                 return;
 413                         }
 414                 }
 415         }
 416
 417         idmap_cache_set_sid2unixid(sid, &id);
 418         return;
 419 }
 420
 421 static char* key_xid2sid_str(TALLOC_CTX* mem_ctx, char t, const char* id) {
 422         return talloc_asprintf(mem_ctx, "IDMAP/%cID2SID/%s", t, id);
 423 }
 424
 425 static char* key_xid2sid(TALLOC_CTX* mem_ctx, char t, int id) {
 426         char str[32];
 427         snprintf(str, sizeof(str), "%d", id);
 428         return key_xid2sid_str(mem_ctx, t, str);
 429 }
 430
 431 static char* key_sid2xid_str(TALLOC_CTX* mem_ctx, const char* id) {
 432         return talloc_asprintf(mem_ctx, "IDMAP/SID2XID/%s", id);
 433 }
 434
 435 static bool idmap_cache_del_xid(char t, int xid)
 436 {
 437         TALLOC_CTX* mem_ctx = talloc_stackframe();
 438         const char* key = key_xid2sid(mem_ctx, t, xid);
 439         char* sid_str = NULL;
 440         time_t timeout;
 441         bool ret = true;
 442
 443         if (!gencache_get(key, mem_ctx, &sid_str, &timeout)) {
 444                 DEBUG(3, ("no entry: %s\n", key));
 445                 ret = false;
 446                 goto done;
 447         }
 448
 449         if (sid_str[0] != '-') {
 450                 const char* sid_key = key_sid2xid_str(mem_ctx, sid_str);
 451                 if (!gencache_del(sid_key)) {
 452                         DEBUG(2, ("failed to delete: %s\n", sid_key));
 453                         ret = false;
 454                 } else {
 455                         DEBUG(5, ("delete: %s\n", sid_key));
 456                 }
 457
 458         }
 459
 460         if (!gencache_del(key)) {
 461                 DEBUG(1, ("failed to delete: %s\n", key));
 462                 ret = false;
 463         } else {
 464                 DEBUG(5, ("delete: %s\n", key));
 465         }
 466
 467 done:
 468         talloc_free(mem_ctx);
 469         return ret;
 470 }
 471
 472 bool idmap_cache_del_uid(uid_t uid) {
 473         return idmap_cache_del_xid('U', uid);
 474 }
 475
 476 bool idmap_cache_del_gid(gid_t gid) {
 477         return idmap_cache_del_xid('G', gid);
 478 }
 479
 480 bool idmap_cache_del_sid(const struct dom_sid *sid)
 481 {
 482         TALLOC_CTX* mem_ctx = talloc_stackframe();
 483         bool ret = true;
 484         bool expired;
 485         struct unixid id;
 486         const char *sid_key;
 487
 488         if (!idmap_cache_find_sid2unixid(sid, &id, &expired)) {
 489                 ret = false;
 490                 goto done;
 491         }
 492
 493         if (id.id != -1) {
 494                 switch (id.type) {
 495                 case ID_TYPE_BOTH:
 496                         idmap_cache_del_xid('U', id.id);
 497                         idmap_cache_del_xid('G', id.id);
 498                         break;
 499                 case ID_TYPE_UID:
 500                         idmap_cache_del_xid('U', id.id);
 501                         break;
 502                 case ID_TYPE_GID:
 503                         idmap_cache_del_xid('G', id.id);
 504                         break;
 505                 default:
 506                         break;
 507                 }
 508         }
 509
 510         sid_key = key_sid2xid_str(mem_ctx, dom_sid_string(mem_ctx, sid));
 511         if (sid_key == NULL) {
 512                 return false;
 513         }
 514         /* If the mapping was symmetric, then this should fail */
 515         gencache_del(sid_key);
 516 done:
 517         talloc_free(mem_ctx);
 518         return ret;
 519 }