source3/winbindd/idmap_autorid.c

   1 /*
   2  *  idmap_autorid: static map between Active Directory/NT RIDs
   3  *  and RFC 2307 accounts
   4  *
   5  *  based on the idmap_rid module, but this module defines the ranges
   6  *  for the domains by automatically allocating a range for each domain
   7  *
   8  *  Copyright (C) Christian Ambach, 2010-2011
   9  *
  10  *  This program is free software; you can redistribute it and/or modify
  11  *  it under the terms of the GNU General Public License as published by
  12  *  the Free Software Foundation; either version 3 of the License, or
  13  *  (at your option) any later version.
  14  *
  15  *  This program is distributed in the hope that it will be useful,
  16  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  *  GNU General Public License for more details.
  19  *
  20  *  You should have received a copy of the GNU General Public License
  21  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  22  *
  23  */
  24
  25 #include "includes.h"
  26 #include "system/filesys.h"
  27 #include "winbindd.h"
  28 #include "dbwrap.h"
  29 #include "idmap.h"
  30 #include "../libcli/security/dom_sid.h"
  31 #include "util_tdb.h"
  32
  33 #undef DBGC_CLASS
  34 #define DBGC_CLASS DBGC_IDMAP
  35
  36 #define HWM "NEXT RANGE"
  37 #define CONFIGKEY "CONFIG"
  38
  39 struct autorid_global_config {
  40         uint32_t minvalue;
  41         uint32_t rangesize;
  42         uint32_t maxranges;
  43 };
  44
  45 struct autorid_domain_config {
  46         struct dom_sid sid;
  47         uint32_t domainnum;
  48         struct autorid_global_config *globalcfg;
  49 };
  50
  51 /* handle to the tdb storing domain <-> range assignments */
  52 static struct db_context *autorid_db;
  53
  54 static NTSTATUS idmap_autorid_get_domainrange(struct db_context *db,
  55                                               void *private_data)
  56 {
  57         NTSTATUS ret;
  58         uint32_t domainnum, hwm;
  59         fstring sidstr;
  60         char *numstr;
  61         struct autorid_domain_config *cfg;
  62
  63         cfg = (struct autorid_domain_config *)private_data;
  64         dom_sid_string_buf(&(cfg->sid), sidstr, sizeof(sidstr));
  65
  66         if (!dbwrap_fetch_uint32(db, sidstr, &domainnum)) {
  67                 DEBUG(10, ("Acquiring new range for domain %s\n", sidstr));
  68
  69                 /* fetch the current HWM */
  70                 if (!dbwrap_fetch_uint32(db, HWM, &hwm)) {
  71                         DEBUG(1, ("Fatal error while fetching current "
  72                                   "HWM value!\n"));
  73                         ret = NT_STATUS_INTERNAL_ERROR;
  74                         goto error;
  75                 }
  76
  77                 /* do we have a range left? */
  78                 if (hwm >= cfg->globalcfg->maxranges) {
  79                         DEBUG(1, ("No more domain ranges available!\n"));
  80                         ret = NT_STATUS_NO_MEMORY;
  81                         goto error;
  82                 }
  83
  84                 /* increase the HWM */
  85                 ret = dbwrap_change_uint32_atomic(db, HWM, &domainnum, 1);
  86                 if (!NT_STATUS_IS_OK(ret)) {
  87                         DEBUG(1, ("Fatal error while fetching a new "
  88                                   "domain range value!\n"));
  89                         goto error;
  90                 }
  91
  92                 /* store away the new mapping in both directions */
  93                 ret = dbwrap_trans_store_uint32(db, sidstr, domainnum);
  94                 if (!NT_STATUS_IS_OK(ret)) {
  95                         DEBUG(1, ("Fatal error while storing new "
  96                                   "domain->range assignment!\n"));
  97                         goto error;
  98                 }
  99
 100                 numstr = talloc_asprintf(db, "%u", domainnum);
 101                 if (!numstr) {
 102                         ret = NT_STATUS_NO_MEMORY;
 103                         goto error;
 104                 }
 105
 106                 ret = dbwrap_trans_store_bystring(db, numstr,
 107                                                   string_term_tdb_data(sidstr),
 108                                                   TDB_INSERT);
 109                 talloc_free(numstr);
 110                 if (!NT_STATUS_IS_OK(ret)) {
 111                         DEBUG(1, ("Fatal error while storing "
 112                                   "new domain->range assignment!\n"));
 113                         goto error;
 114                 }
 115                 DEBUG(5, ("Acquired new range #%d for domain %s\n",
 116                           domainnum, sidstr));
 117         }
 118
 119         DEBUG(10, ("Using range #%d for domain %s\n", domainnum, sidstr));
 120         cfg->domainnum = domainnum;
 121
 122         return NT_STATUS_OK;
 123
 124       error:
 125         return ret;
 126
 127 }
 128
 129 static NTSTATUS idmap_autorid_id_to_sid(struct autorid_global_config *cfg,
 130                                         struct id_map *map)
 131 {
 132         uint32_t range;
 133         TDB_DATA data;
 134         char *keystr;
 135         struct dom_sid sid;
 136
 137         /* can this be one of our ids? */
 138         if (map->xid.id < cfg->minvalue) {
 139                 DEBUG(10, ("id %d is lower than minimum value, "
 140                            "ignoring mapping request\n", map->xid.id));
 141                 map->status = ID_UNKNOWN;
 142                 return NT_STATUS_OK;
 143         }
 144
 145         if (map->xid.id > (cfg->minvalue + cfg->rangesize * cfg->maxranges)) {
 146                 DEBUG(10, ("id %d is outside of maximum id value, "
 147                            "ignoring mapping request\n", map->xid.id));
 148                 map->status = ID_UNKNOWN;
 149                 return NT_STATUS_OK;
 150         }
 151
 152         /* determine the range of this uid */
 153         range = ((map->xid.id - cfg->minvalue) / cfg->rangesize);
 154
 155         keystr = talloc_asprintf(talloc_tos(), "%u", range);
 156         if (!keystr) {
 157                 return NT_STATUS_NO_MEMORY;
 158         }
 159
 160         data = dbwrap_fetch_bystring(autorid_db, talloc_tos(), keystr);
 161         TALLOC_FREE(keystr);
 162
 163         if (!data.dptr) {
 164                 DEBUG(4, ("id %d belongs to range %d which does not have "
 165                           "domain mapping, ignoring mapping request\n",
 166                           map->xid.id, range));
 167                 map->status = ID_UNKNOWN;
 168                 return NT_STATUS_OK;
 169         }
 170
 171         string_to_sid(&sid, (const char *)data.dptr);
 172         TALLOC_FREE(data.dptr);
 173
 174         sid_compose(map->sid, &sid,
 175                     (map->xid.id - cfg->minvalue -
 176                      range * cfg->rangesize));
 177
 178         /* We **really** should have some way of validating
 179            the SID exists and is the correct type here.  But
 180            that is a deficiency in the idmap_rid design. */
 181
 182         map->status = ID_MAPPED;
 183         return NT_STATUS_OK;
 184 }
 185
 186 /**********************************
 187  Single sid to id lookup function.
 188 **********************************/
 189
 190 static NTSTATUS idmap_autorid_sid_to_id(struct autorid_global_config *global,
 191                                         struct autorid_domain_config *domain,
 192                                         struct id_map *map)
 193 {
 194         uint32_t rid;
 195
 196         sid_peek_rid(map->sid, &rid);
 197
 198         /* if the rid is higher than the size of the range, we cannot map it */
 199         if (rid >= global->rangesize) {
 200                 map->status = ID_UNKNOWN;
 201                 DEBUG(2, ("RID %d is larger then size of range (%d), "
 202                           "user cannot be mapped\n", rid, global->rangesize));
 203                 return NT_STATUS_UNSUCCESSFUL;
 204         }
 205         map->xid.id = global->minvalue +
 206             (global->rangesize * domain->domainnum)+rid;
 207
 208         /* We **really** should have some way of validating
 209            the SID exists and is the correct type here.  But
 210            that is a deficiency in the idmap_rid design. */
 211
 212         map->status = ID_MAPPED;
 213
 214         return NT_STATUS_OK;
 215 }
 216
 217 /**********************************
 218  lookup a set of unix ids.
 219 **********************************/
 220
 221 static NTSTATUS idmap_autorid_unixids_to_sids(struct idmap_domain *dom,
 222                                               struct id_map **ids)
 223 {
 224         struct autorid_global_config *globalcfg;
 225         NTSTATUS ret;
 226         int i;
 227
 228         /* initialize the status to avoid surprise */
 229         for (i = 0; ids[i]; i++) {
 230                 ids[i]->status = ID_UNKNOWN;
 231         }
 232
 233         globalcfg = talloc_get_type(dom->private_data,
 234                                     struct autorid_global_config);
 235
 236         for (i = 0; ids[i]; i++) {
 237
 238                 ret = idmap_autorid_id_to_sid(globalcfg, ids[i]);
 239
 240                 if ((!NT_STATUS_IS_OK(ret)) &&
 241                     (!NT_STATUS_EQUAL(ret, NT_STATUS_NONE_MAPPED))) {
 242                         /* some fatal error occurred, log it */
 243                         DEBUG(3, ("Unexpected error resolving an ID "
 244                                   " (%d)\n", ids[i]->xid.id));
 245                         goto failure;
 246                 }
 247         }
 248         return NT_STATUS_OK;
 249
 250       failure:
 251         return ret;
 252 }
 253
 254 /**********************************
 255  lookup a set of sids.
 256 **********************************/
 257
 258 static NTSTATUS idmap_autorid_sids_to_unixids(struct idmap_domain *dom,
 259                                               struct id_map **ids)
 260 {
 261         struct autorid_global_config *global;
 262         NTSTATUS ret;
 263         int i;
 264
 265         /* initialize the status to avoid surprise */
 266         for (i = 0; ids[i]; i++) {
 267                 ids[i]->status = ID_UNKNOWN;
 268         }
 269
 270         global = talloc_get_type(dom->private_data,
 271                                  struct autorid_global_config);
 272
 273         for (i = 0; ids[i]; i++) {
 274                 struct winbindd_tdc_domain *domain;
 275                 struct autorid_domain_config domaincfg;
 276                 uint32_t rid;
 277
 278                 ZERO_STRUCT(domaincfg);
 279
 280                 sid_copy(&domaincfg.sid, ids[i]->sid);
 281                 if (!sid_split_rid(&domaincfg.sid, &rid)) {
 282                         DEBUG(4, ("Could not determine domain SID from %s, "
 283                                   "ignoring mapping request\n",
 284                                   sid_string_dbg(ids[i]->sid)));
 285                         continue;
 286                 }
 287
 288                 /*
 289                  * Check if the domain is around
 290                  */
 291                 domain = wcache_tdc_fetch_domainbysid(talloc_tos(),
 292                                                       &domaincfg.sid);
 293                 if (domain == NULL) {
 294                         DEBUG(10, ("Ignoring unknown domain sid %s\n",
 295                                    sid_string_dbg(&domaincfg.sid)));
 296                         continue;
 297                 }
 298                 TALLOC_FREE(domain);
 299
 300                 domaincfg.globalcfg = global;
 301
 302                 ret = dbwrap_trans_do(autorid_db,
 303                                       idmap_autorid_get_domainrange,
 304                                       &domaincfg);
 305
 306                 if (!NT_STATUS_IS_OK(ret)) {
 307                         DEBUG(3, ("Could not determine range for domain, "
 308                                   "check previous messages for reason\n"));
 309                         goto failure;
 310                 }
 311
 312                 ret = idmap_autorid_sid_to_id(global, &domaincfg, ids[i]);
 313
 314                 if ((!NT_STATUS_IS_OK(ret)) &&
 315                     (!NT_STATUS_EQUAL(ret, NT_STATUS_NONE_MAPPED))) {
 316                         /* some fatal error occurred, log it */
 317                         DEBUG(3, ("Unexpected error resolving a SID (%s)\n",
 318                                   sid_string_dbg(ids[i]->sid)));
 319                         goto failure;
 320                 }
 321         }
 322         return NT_STATUS_OK;
 323
 324       failure:
 325         return ret;
 326
 327 }
 328
 329 /*
 330  * open and initialize the database which stores the ranges for the domains
 331  */
 332 static NTSTATUS idmap_autorid_db_init(void)
 333 {
 334         int32_t hwm;
 335
 336         if (autorid_db) {
 337                 /* its already open */
 338                 return NT_STATUS_OK;
 339         }
 340
 341         /* Open idmap repository */
 342         autorid_db = db_open(NULL, state_path("autorid.tdb"), 0,
 343                              TDB_DEFAULT, O_RDWR | O_CREAT, 0644);
 344
 345         if (!autorid_db) {
 346                 DEBUG(0, ("Unable to open idmap_autorid database '%s'\n",
 347                           state_path("autorid.tdb")));
 348                 return NT_STATUS_UNSUCCESSFUL;
 349         }
 350
 351         /* Initialize high water mark for the currently used range to 0 */
 352         hwm = dbwrap_fetch_int32(autorid_db, HWM);
 353         if ((hwm < 0)) {
 354                 if (!NT_STATUS_IS_OK
 355                     (dbwrap_trans_store_int32(autorid_db, HWM, 0))) {
 356                         DEBUG(0,
 357                               ("Unable to initialise HWM in autorid "
 358                                "database\n"));
 359                         return NT_STATUS_INTERNAL_DB_ERROR;
 360                 }
 361         }
 362
 363         return NT_STATUS_OK;
 364 }
 365
 366 static struct autorid_global_config *idmap_autorid_loadconfig(TALLOC_CTX * ctx)
 367 {
 368
 369         TDB_DATA data;
 370         struct autorid_global_config *cfg;
 371         unsigned long minvalue, rangesize, maxranges;
 372
 373         data = dbwrap_fetch_bystring(autorid_db, ctx, CONFIGKEY);
 374
 375         if (!data.dptr) {
 376                 DEBUG(10, ("No saved config found\n"));
 377                 return NULL;
 378         }
 379
 380         cfg = talloc_zero(ctx, struct autorid_global_config);
 381         if (!cfg) {
 382                 return NULL;
 383         }
 384
 385         if (sscanf((char *)data.dptr,
 386                    "minvalue:%lu rangesize:%lu maxranges:%lu",
 387                    &minvalue, &rangesize, &maxranges) != 3) {
 388                 DEBUG(1,
 389                       ("Found invalid configuration data"
 390                        "creating new config\n"));
 391                 return NULL;
 392         }
 393
 394         cfg->minvalue = minvalue;
 395         cfg->rangesize = rangesize;
 396         cfg->maxranges = maxranges;
 397
 398         DEBUG(10, ("Loaded previously stored configuration "
 399                    "minvalue:%d rangesize:%d\n",
 400                    cfg->minvalue, cfg->rangesize));
 401
 402         return cfg;
 403
 404 }
 405
 406 static NTSTATUS idmap_autorid_saveconfig(struct autorid_global_config *cfg)
 407 {
 408
 409         NTSTATUS status;
 410         TDB_DATA data;
 411         char *cfgstr;
 412
 413         cfgstr =
 414             talloc_asprintf(talloc_tos(),
 415                             "minvalue:%u rangesize:%u maxranges:%u",
 416                             cfg->minvalue, cfg->rangesize, cfg->maxranges);
 417
 418         if (!cfgstr) {
 419                 return NT_STATUS_NO_MEMORY;
 420         }
 421
 422         data = string_tdb_data(cfgstr);
 423
 424         status = dbwrap_trans_store_bystring(autorid_db, CONFIGKEY,
 425                                              data, TDB_REPLACE);
 426
 427         talloc_free(cfgstr);
 428
 429         return status;
 430 }
 431
 432 static NTSTATUS idmap_autorid_initialize(struct idmap_domain *dom)
 433 {
 434         struct autorid_global_config *config;
 435         struct autorid_global_config *storedconfig = NULL;
 436         NTSTATUS status;
 437         uint32_t hwm;
 438
 439         config = talloc_zero(dom, struct autorid_global_config);
 440         if (!config) {
 441                 DEBUG(0, ("Out of memory!\n"));
 442                 return NT_STATUS_NO_MEMORY;
 443         }
 444
 445         status = idmap_autorid_db_init();
 446         if (!NT_STATUS_IS_OK(status)) {
 447                 goto error;
 448         }
 449
 450         config->minvalue = dom->low_id;
 451         config->rangesize = lp_parm_int(-1, "autorid", "rangesize", 100000);
 452
 453         if (config->rangesize < 2000) {
 454                 DEBUG(1, ("autorid rangesize must be at least 2000\n"));
 455                 status = NT_STATUS_INVALID_PARAMETER;
 456                 goto error;
 457         }
 458
 459         config->maxranges = (dom->high_id - dom->low_id + 1) /
 460             config->rangesize;
 461
 462         if (config->maxranges == 0) {
 463                 DEBUG(1, ("allowed uid range is smaller then rangesize, "
 464                           "increase uid range or decrease rangesize\n"));
 465                 status = NT_STATUS_INVALID_PARAMETER;
 466                 goto error;
 467         }
 468
 469         /* check if the high-low limit is a multiple of the rangesize */
 470         if ((dom->high_id - dom->low_id + 1) % config->rangesize != 0) {
 471                 DEBUG(5, ("High uid-low uid difference of %d "
 472                           "is not a multiple of the rangesize %d, "
 473                           "limiting ranges to lower boundary number of %d\n",
 474                           (dom->high_id - dom->low_id + 1), config->rangesize,
 475                           config->maxranges));
 476         }
 477
 478         DEBUG(10, ("Current configuration in config is "
 479                    "minvalue:%d rangesize:%d maxranges:%d\n",
 480                    config->minvalue, config->rangesize, config->maxranges));
 481
 482         /* read previously stored config and current HWM */
 483         storedconfig = idmap_autorid_loadconfig(talloc_tos());
 484
 485         if (!dbwrap_fetch_uint32(autorid_db, HWM, &hwm)) {
 486                 DEBUG(1, ("Fatal error while fetching current "
 487                           "HWM value!\n"));
 488                 status = NT_STATUS_INTERNAL_ERROR;
 489                 goto error;
 490         }
 491
 492         /* did the minimum value or rangesize change? */
 493         if (storedconfig &&
 494             ((storedconfig->minvalue != config->minvalue) ||
 495              (storedconfig->rangesize != config->rangesize))) {
 496                 DEBUG(1, ("New configuration values for rangesize or "
 497                           "minimum uid value conflict with previously "
 498                           "used values! Aborting initialization\n"));
 499                 status = NT_STATUS_INVALID_PARAMETER;
 500                 goto error;
 501         }
 502
 503         /*
 504          * has the highest uid value been reduced to setting that is not
 505          * sufficient any more for already existing ranges?
 506          */
 507         if (hwm > config->maxranges) {
 508                 DEBUG(1, ("New upper uid limit is too low to cover "
 509                           "existing mappings! Aborting initialization\n"));
 510                 status = NT_STATUS_INVALID_PARAMETER;
 511                 goto error;
 512         }
 513
 514         status = idmap_autorid_saveconfig(config);
 515
 516         if (!NT_STATUS_IS_OK(status)) {
 517                 DEBUG(1, ("Failed to store configuration data!\n"));
 518                 goto error;
 519         }
 520
 521         DEBUG(5, ("%d domain ranges with a size of %d are available\n",
 522                   config->maxranges, config->rangesize));
 523
 524         dom->private_data = config;
 525
 526         if (!NT_STATUS_IS_OK(status)) {
 527                 goto error;
 528         }
 529
 530         return NT_STATUS_OK;
 531
 532       error:
 533         talloc_free(config);
 534         talloc_free(storedconfig);
 535
 536         return status;
 537 }
 538
 539 /*
 540   Close the idmap tdb instance
 541 */
 542 static struct idmap_methods autorid_methods = {
 543         .init = idmap_autorid_initialize,
 544         .unixids_to_sids = idmap_autorid_unixids_to_sids,
 545         .sids_to_unixids = idmap_autorid_sids_to_unixids,
 546 };
 547
 548 NTSTATUS idmap_autorid_init(void)
 549 {
 550         return smb_register_idmap(SMB_IDMAP_INTERFACE_VERSION,
 551                                   "autorid", &autorid_methods);
 552 }