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
  24 /**
  25  * Find a sid2uid mapping
  26  * @param[in] sid               the sid to map
  27  * @param[out] puid             where to put the result
  28  * @param[out] expired          is the cache entry expired?
  29  * @retval Was anything in the cache at all?
  30  *
  31  * If *puid == -1 this was a negative mapping.
  32  */
  33
  34 bool idmap_cache_find_sid2uid(const struct dom_sid *sid, uid_t *puid,
  35                               bool *expired)
  36 {
  37         fstring sidstr;
  38         char *key;
  39         char *value;
  40         char *endptr;
  41         time_t timeout;
  42         uid_t uid;
  43         bool ret;
  44
  45         key = talloc_asprintf(talloc_tos(), "IDMAP/SID2UID/%s",
  46                               sid_to_fstring(sidstr, sid));
  47         if (key == NULL) {
  48                 return false;
  49         }
  50         ret = gencache_get(key, &value, &timeout);
  51         TALLOC_FREE(key);
  52         if (!ret) {
  53                 return false;
  54         }
  55         uid = strtol(value, &endptr, 10);
  56         ret = (*endptr == '\0');
  57         SAFE_FREE(value);
  58         if (ret) {
  59                 *puid = uid;
  60                 *expired = (timeout <= time(NULL));
  61         }
  62         return ret;
  63 }
  64
  65 /**
  66  * Find a uid2sid mapping
  67  * @param[in] uid               the uid to map
  68  * @param[out] sid              where to put the result
  69  * @param[out] expired          is the cache entry expired?
  70  * @retval Was anything in the cache at all?
  71  *
  72  * If "is_null_sid(sid)", this was a negative mapping.
  73  */
  74
  75 bool idmap_cache_find_uid2sid(uid_t uid, struct dom_sid *sid, bool *expired)
  76 {
  77         char *key;
  78         char *value;
  79         time_t timeout;
  80         bool ret = true;
  81
  82         key = talloc_asprintf(talloc_tos(), "IDMAP/UID2SID/%d", (int)uid);
  83         if (key == NULL) {
  84                 return false;
  85         }
  86         ret = gencache_get(key, &value, &timeout);
  87         TALLOC_FREE(key);
  88         if (!ret) {
  89                 return false;
  90         }
  91         ZERO_STRUCTP(sid);
  92         if (value[0] != '-') {
  93                 ret = string_to_sid(sid, value);
  94         }
  95         SAFE_FREE(value);
  96         if (ret) {
  97                 *expired = (timeout <= time(NULL));
  98         }
  99         return ret;
 100 }
 101
 102 /**
 103  * Store a mapping in the idmap cache
 104  * @param[in] sid               the sid to map
 105  * @param[in] uid               the uid to map
 106  *
 107  * If both parameters are valid values, then a positive mapping in both
 108  * directions is stored. If "is_null_sid(sid)" is true, then this will be a
 109  * negative mapping of uid, we want to cache that for this uid we could not
 110  * find anything. Likewise if "uid==-1", then we want to cache that we did not
 111  * find a mapping for the sid passed here.
 112  */
 113
 114 void idmap_cache_set_sid2uid(const struct dom_sid *sid, uid_t uid)
 115 {
 116         time_t now = time(NULL);
 117         time_t timeout;
 118         fstring sidstr, key, value;
 119
 120         if (!is_null_sid(sid)) {
 121                 fstr_sprintf(key, "IDMAP/SID2UID/%s",
 122                              sid_to_fstring(sidstr, sid));
 123                 fstr_sprintf(value, "%d", (int)uid);
 124                 timeout = (uid == -1)
 125                         ? lp_idmap_negative_cache_time()
 126                         : lp_idmap_cache_time();
 127                 gencache_set(key, value, now + timeout);
 128         }
 129         if (uid != -1) {
 130                 fstr_sprintf(key, "IDMAP/UID2SID/%d", (int)uid);
 131                 if (is_null_sid(sid)) {
 132                         /* negative uid mapping */
 133                         fstrcpy(value, "-");
 134                         timeout = lp_idmap_negative_cache_time();
 135                 }
 136                 else {
 137                         sid_to_fstring(value, sid);
 138                         timeout = lp_idmap_cache_time();
 139                 }
 140                 gencache_set(key, value, now + timeout);
 141         }
 142 }
 143
 144 /**
 145  * Find a sid2gid mapping
 146  * @param[in] sid               the sid to map
 147  * @param[out] pgid             where to put the result
 148  * @param[out] expired          is the cache entry expired?
 149  * @retval Was anything in the cache at all?
 150  *
 151  * If *pgid == -1 this was a negative mapping.
 152  */
 153
 154 bool idmap_cache_find_sid2gid(const struct dom_sid *sid, gid_t *pgid,
 155                               bool *expired)
 156 {
 157         fstring sidstr;
 158         char *key;
 159         char *value;
 160         char *endptr;
 161         time_t timeout;
 162         gid_t gid;
 163         bool ret;
 164
 165         key = talloc_asprintf(talloc_tos(), "IDMAP/SID2GID/%s",
 166                               sid_to_fstring(sidstr, sid));
 167         if (key == NULL) {
 168                 return false;
 169         }
 170         ret = gencache_get(key, &value, &timeout);
 171         TALLOC_FREE(key);
 172         if (!ret) {
 173                 return false;
 174         }
 175         gid = strtol(value, &endptr, 10);
 176         ret = (*endptr == '\0');
 177         SAFE_FREE(value);
 178         if (ret) {
 179                 *pgid = gid;
 180                 *expired = (timeout <= time(NULL));
 181         }
 182         return ret;
 183 }
 184
 185 /**
 186  * Find a gid2sid mapping
 187  * @param[in] gid               the gid to map
 188  * @param[out] sid              where to put the result
 189  * @param[out] expired          is the cache entry expired?
 190  * @retval Was anything in the cache at all?
 191  *
 192  * If "is_null_sid(sid)", this was a negative mapping.
 193  */
 194
 195 bool idmap_cache_find_gid2sid(gid_t gid, struct dom_sid *sid, bool *expired)
 196 {
 197         char *key;
 198         char *value;
 199         time_t timeout;
 200         bool ret = true;
 201
 202         key = talloc_asprintf(talloc_tos(), "IDMAP/GID2SID/%d", (int)gid);
 203         if (key == NULL) {
 204                 return false;
 205         }
 206         ret = gencache_get(key, &value, &timeout);
 207         TALLOC_FREE(key);
 208         if (!ret) {
 209                 return false;
 210         }
 211         ZERO_STRUCTP(sid);
 212         if (value[0] != '-') {
 213                 ret = string_to_sid(sid, value);
 214         }
 215         SAFE_FREE(value);
 216         if (ret) {
 217                 *expired = (timeout <= time(NULL));
 218         }
 219         return ret;
 220 }
 221
 222 /**
 223  * Store a mapping in the idmap cache
 224  * @param[in] sid               the sid to map
 225  * @param[in] gid               the gid to map
 226  *
 227  * If both parameters are valid values, then a positive mapping in both
 228  * directions is stored. If "is_null_sid(sid)" is true, then this will be a
 229  * negative mapping of gid, we want to cache that for this gid we could not
 230  * find anything. Likewise if "gid==-1", then we want to cache that we did not
 231  * find a mapping for the sid passed here.
 232  */
 233
 234 void idmap_cache_set_sid2gid(const struct dom_sid *sid, gid_t gid)
 235 {
 236         time_t now = time(NULL);
 237         time_t timeout;
 238         fstring sidstr, key, value;
 239
 240         if (!is_null_sid(sid)) {
 241                 fstr_sprintf(key, "IDMAP/SID2GID/%s",
 242                              sid_to_fstring(sidstr, sid));
 243                 fstr_sprintf(value, "%d", (int)gid);
 244                 timeout = (gid == -1)
 245                         ? lp_idmap_negative_cache_time()
 246                         : lp_idmap_cache_time();
 247                 gencache_set(key, value, now + timeout);
 248         }
 249         if (gid != -1) {
 250                 fstr_sprintf(key, "IDMAP/GID2SID/%d", (int)gid);
 251                 if (is_null_sid(sid)) {
 252                         /* negative gid mapping */
 253                         fstrcpy(value, "-");
 254                         timeout = lp_idmap_negative_cache_time();
 255                 }
 256                 else {
 257                         sid_to_fstring(value, sid);
 258                         timeout = lp_idmap_cache_time();
 259                 }
 260                 gencache_set(key, value, now + timeout);
 261         }
 262 }
 263
 264 static char* key_xid2sid_str(TALLOC_CTX* mem_ctx, char t, const char* id) {
 265         return talloc_asprintf(mem_ctx, "IDMAP/%cID2SID/%s", t, id);
 266 }
 267
 268 static char* key_xid2sid(TALLOC_CTX* mem_ctx, char t, int id) {
 269         char str[32];
 270         snprintf(str, sizeof(str), "%d", id);
 271         return key_xid2sid_str(mem_ctx, t, str);
 272 }
 273
 274 static char* key_sid2xid_str(TALLOC_CTX* mem_ctx, char t, const char* sid) {
 275         return talloc_asprintf(mem_ctx, "IDMAP/SID2%cID/%s", t, sid);
 276 }
 277
 278 /* static char* key_sid2xid(TALLOC_CTX* mem_ctx, char t, const struct dom_sid* sid) */
 279 /* { */
 280 /*      char* sid_str = sid_string_talloc(mem_ctx, sid); */
 281 /*      char* key = key_sid2xid_str(mem_ctx, t, sid_str); */
 282 /*      talloc_free(sid_str); */
 283 /*      return key; */
 284 /* } */
 285
 286 static bool idmap_cache_del_xid(char t, int xid)
 287 {
 288         TALLOC_CTX* mem_ctx = talloc_stackframe();
 289         const char* key = key_xid2sid(mem_ctx, t, xid);
 290         char* sid_str = NULL;
 291         time_t timeout;
 292         bool ret = true;
 293
 294         if (!gencache_get(key, &sid_str, &timeout)) {
 295                 DEBUG(3, ("no entry: %s\n", key));
 296                 ret = false;
 297                 goto done;
 298         }
 299
 300         if (sid_str[0] != '-') {
 301                 const char* sid_key = key_sid2xid_str(mem_ctx, t, sid_str);
 302                 if (!gencache_del(sid_key)) {
 303                         DEBUG(2, ("failed to delete: %s\n", sid_key));
 304                         ret = false;
 305                 } else {
 306                         DEBUG(5, ("delete: %s\n", sid_key));
 307                 }
 308
 309         }
 310
 311         if (!gencache_del(key)) {
 312                 DEBUG(1, ("failed to delete: %s\n", key));
 313                 ret = false;
 314         } else {
 315                 DEBUG(5, ("delete: %s\n", key));
 316         }
 317
 318 done:
 319         talloc_free(mem_ctx);
 320         return ret;
 321 }
 322
 323 bool idmap_cache_del_uid(uid_t uid) {
 324         return idmap_cache_del_xid('U', uid);
 325 }
 326
 327 bool idmap_cache_del_gid(gid_t gid) {
 328         return idmap_cache_del_xid('G', gid);
 329 }
 330
 331 static bool idmap_cache_del_sid2xid(TALLOC_CTX* mem_ctx, char t, const char* sid)
 332 {
 333         const char* sid_key = key_sid2xid_str(mem_ctx, t, sid);
 334         char* xid_str;
 335         time_t timeout;
 336         bool ret = true;
 337
 338         if (!gencache_get(sid_key, &xid_str, &timeout)) {
 339                 ret = false;
 340                 goto done;
 341         }
 342
 343         if (atoi(xid_str) != -1) {
 344                 const char* xid_key = key_xid2sid_str(mem_ctx, t, xid_str);
 345                 if (!gencache_del(xid_key)) {
 346                         DEBUG(2, ("failed to delete: %s\n", xid_key));
 347                         ret = false;
 348                 } else {
 349                         DEBUG(5, ("delete: %s\n", xid_key));
 350                 }
 351         }
 352
 353         if (!gencache_del(sid_key)) {
 354                 DEBUG(2, ("failed to delete: %s\n", sid_key));
 355                 ret = false;
 356         } else {
 357                 DEBUG(5, ("delete: %s\n", sid_key));
 358         }
 359 done:
 360         return ret;
 361 }
 362
 363 bool idmap_cache_del_sid(const struct dom_sid *sid)
 364 {
 365         TALLOC_CTX* mem_ctx = talloc_stackframe();
 366         const char* sid_str = sid_string_talloc(mem_ctx, sid);
 367         bool ret = true;
 368
 369         if (!idmap_cache_del_sid2xid(mem_ctx, 'U', sid_str) &&
 370             !idmap_cache_del_sid2xid(mem_ctx, 'G', sid_str))
 371         {
 372                 DEBUG(3, ("no entry: %s\n", key_xid2sid_str(mem_ctx, '?', sid_str)));
 373                 ret = false;
 374         }
 375
 376         talloc_free(mem_ctx);
 377         return ret;
 378 }