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