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