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 "winbindd.h"
  27 #include "dbwrap.h"
  28 #include "idmap.h"
  29 #include "../libcli/security/dom_sid.h"
  30
  31 #undef DBGC_CLASS
  32 #define DBGC_CLASS DBGC_IDMAP
  33
  34 #define HWM "NEXT RANGE"
  35 #define CONFIGKEY "CONFIG"
  36
  37 struct autorid_global_config {
  38         uint32_t minvalue;
  39         uint32_t rangesize;
  40         uint32_t maxranges;
  41 };
  42
  43 struct autorid_domain_config {
  44         struct dom_sid sid;
  45         uint32_t domainnum;
  46         struct autorid_global_config *globalcfg;
  47 };
  48
  49 /* handle to the tdb storing domain <-> range assignments */
  50 static struct db_context *autorid_db;
  51
  52 static NTSTATUS idmap_autorid_get_domainrange(struct db_context *db,
  53                                               void *private_data)
  54 {
  55         NTSTATUS ret;
  56         uint32_t domainnum, hwm;
  57         char *sidstr, *numstr;
  58         struct autorid_domain_config *cfg;
  59
  60         cfg = (struct autorid_domain_config *)private_data;
  61         sidstr = dom_sid_string(talloc_tos(), &(cfg->sid));
  62
  63         if (!sidstr) {
  64                 return NT_STATUS_NO_MEMORY;
  65         }
  66
  67         if (!dbwrap_fetch_uint32(db, sidstr, &domainnum)) {
  68                 DEBUG(10, ("Acquiring new range for domain %s\n", sidstr));
  69
  70                 /* fetch the current HWM */
  71                 if (!dbwrap_fetch_uint32(db, HWM, &hwm)) {
  72                         DEBUG(1, ("Fatal error while fetching current "
  73                                   "HWM value!\n"));
  74                         ret = NT_STATUS_INTERNAL_ERROR;
  75                         goto error;
  76                 }
  77
  78                 /* do we have a range left? */
  79                 if (hwm >= cfg->globalcfg->maxranges) {
  80                         DEBUG(1, ("No more domain ranges available!\n"));
  81                         ret = NT_STATUS_NO_MEMORY;
  82                         goto error;
  83                 }
  84
  85                 /* increase the HWM */
  86                 ret = dbwrap_change_uint32_atomic(db, HWM, &domainnum, 1);
  87                 if (!NT_STATUS_IS_OK(ret)) {
  88                         DEBUG(1, ("Fatal error while fetching a new "
  89                                   "domain range value!\n"));
  90                         goto error;
  91                 }
  92
  93                 /* store away the new mapping in both directions */
  94                 ret = dbwrap_trans_store_uint32(db, sidstr, domainnum);
  95                 if (!NT_STATUS_IS_OK(ret)) {
  96                         DEBUG(1, ("Fatal error while storing new "
  97                                   "domain->range assignment!\n"));
  98                         goto error;
  99                 }
 100
 101                 numstr = talloc_asprintf(db, "%u", domainnum);
 102                 if (!numstr) {
 103                         ret = NT_STATUS_NO_MEMORY;
 104                         goto error;
 105                 }
 106
 107                 ret = dbwrap_trans_store_bystring(db, numstr,
 108                                                   string_term_tdb_data(sidstr),
 109                                                   TDB_INSERT);
 110                 if (!NT_STATUS_IS_OK(ret)) {
 111                         talloc_free(numstr);
 112                         DEBUG(1, ("Fatal error while storing "
 113                                   "new domain->range assignment!\n"));
 114                         goto error;
 115                 }
 116                 talloc_free(numstr);
 117                 DEBUG(5, ("Acquired new range #%d for domain %s\n",
 118                           domainnum, sidstr));
 119         }
 120
 121         DEBUG(10, ("Using range #%d for domain %s\n", domainnum, sidstr));
 122         cfg->domainnum = domainnum;
 123
 124         talloc_free(sidstr);
 125         return NT_STATUS_OK;
 126
 127       error:
 128         talloc_free(sidstr);
 129         return ret;
 130
 131 }
 132
 133 static NTSTATUS idmap_autorid_id_to_sid(TALLOC_CTX * memctx,
 134                                         struct autorid_global_config *cfg,
 135                                         struct id_map *map)
 136 {
 137         uint32_t range;
 138         TDB_DATA data;
 139         char *keystr;
 140         struct dom_sid sid;
 141
 142         /* can this be one of our ids? */
 143         if (map->xid.id < cfg->minvalue) {
 144                 DEBUG(10, ("id %d is lower than minimum value, "
 145                            "ignoring mapping request\n", map->xid.id));
 146                 map->status = ID_UNKNOWN;
 147                 return NT_STATUS_OK;
 148         }
 149
 150         if (map->xid.id > (cfg->minvalue + cfg->rangesize * cfg->maxranges)) {
 151                 DEBUG(10, ("id %d is outside of maximum id value, "
 152                            "ignoring mapping request\n", map->xid.id));
 153                 map->status = ID_UNKNOWN;
 154                 return NT_STATUS_OK;
 155         }
 156
 157         /* determine the range of this uid */
 158         range = ((map->xid.id - cfg->minvalue) / cfg->rangesize);
 159
 160         keystr = talloc_asprintf(memctx, "%u", range);
 161         if (!keystr) {
 162                 return NT_STATUS_NO_MEMORY;
 163         }
 164
 165         data = dbwrap_fetch_bystring(autorid_db, memctx, keystr);
 166
 167         if (!data.dptr) {
 168                 DEBUG(4, ("id %d belongs to range %d which does not have "
 169                           "domain mapping, ignoring mapping request\n",
 170                           map->xid.id, range));
 171         } else {
 172                 string_to_sid(&sid, (const char *)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         }
 184         return NT_STATUS_OK;
 185 }
 186
 187 /**********************************
 188  Single sid to id lookup function.
 189 **********************************/
 190
 191 static NTSTATUS idmap_autorid_sid_to_id(struct autorid_global_config *global,
 192                                         struct autorid_domain_config *domain,
 193                                         struct id_map *map)
 194 {
 195         uint32_t rid;
 196
 197         sid_peek_rid(map->sid, &rid);
 198
 199         /* if the rid is higher than the size of the range, we cannot map it */
 200         if (rid >= global->rangesize) {
 201                 map->status = ID_UNKNOWN;
 202                 DEBUG(2, ("RID %d is larger then size of range (%d), "
 203                           "user cannot be mapped\n", rid, global->rangesize));
 204                 return NT_STATUS_UNSUCCESSFUL;
 205         }
 206         map->xid.id = global->minvalue +
 207             (global->rangesize * domain->domainnum)+rid;
 208
 209         /* We **really** should have some way of validating
 210            the SID exists and is the correct type here.  But
 211            that is a deficiency in the idmap_rid design. */
 212
 213         map->status = ID_MAPPED;
 214
 215         return NT_STATUS_OK;
 216 }
 217
 218 /**********************************
 219  lookup a set of unix ids.
 220 **********************************/
 221
 222 static NTSTATUS idmap_autorid_unixids_to_sids(struct idmap_domain *dom,
 223                                               struct id_map **ids)
 224 {
 225         struct autorid_global_config *globalcfg;
 226         TALLOC_CTX *ctx;
 227         NTSTATUS ret;
 228         int i;
 229
 230         /* initialize the status to avoid surprise */
 231         for (i = 0; ids[i]; i++) {
 232                 ids[i]->status = ID_UNKNOWN;
 233         }
 234
 235         globalcfg = talloc_get_type(dom->private_data,
 236                                     struct autorid_global_config);
 237
 238         ctx = talloc_new(dom);
 239         if (!ctx) {
 240                 DEBUG(0, ("Out of memory!\n"));
 241                 return NT_STATUS_NO_MEMORY;
 242         }
 243
 244         for (i = 0; ids[i]; i++) {
 245
 246                 ret = idmap_autorid_id_to_sid(ctx, globalcfg, ids[i]);
 247
 248                 if ((!NT_STATUS_IS_OK(ret)) &&
 249                     (!NT_STATUS_EQUAL(ret, NT_STATUS_NONE_MAPPED))) {
 250                         /* some fatal error occurred, log it */
 251                         DEBUG(3, ("Unexpected error resolving an ID "
 252                                   " (%d)\n", ids[i]->xid.id));
 253                         goto failure;
 254                 }
 255         }
 256
 257         talloc_free(ctx);
 258         return NT_STATUS_OK;
 259
 260       failure:
 261         talloc_free(ctx);
 262         return ret;
 263
 264 }
 265
 266 /**********************************
 267  lookup a set of sids.
 268 **********************************/
 269
 270 static NTSTATUS idmap_autorid_sids_to_unixids(struct idmap_domain *dom,
 271                                               struct id_map **ids)
 272 {
 273         struct autorid_global_config *global;
 274         TALLOC_CTX *ctx;
 275         NTSTATUS ret;
 276         int i;
 277
 278         ctx = talloc_new(dom);
 279         if (!ctx) {
 280                 DEBUG(0, ("Out of memory!\n"));
 281                 ret = NT_STATUS_NO_MEMORY;
 282                 goto failure;
 283         }
 284
 285         /* initialize the status to avoid surprise */
 286         for (i = 0; ids[i]; i++) {
 287                 ids[i]->status = ID_UNKNOWN;
 288         }
 289
 290         global = talloc_get_type(dom->private_data,
 291                                  struct autorid_global_config);
 292
 293         for (i = 0; ids[i]; i++) {
 294                 struct winbindd_tdc_domain *domain;
 295                 struct autorid_domain_config domaincfg;
 296                 uint32_t rid;
 297
 298                 ZERO_STRUCT(domaincfg);
 299
 300                 sid_copy(&domaincfg.sid, ids[i]->sid);
 301                 if (!sid_split_rid(&domaincfg.sid, &rid)) {
 302                         DEBUG(4, ("Could not determine domain SID from %s, "
 303                                   "ignoring mapping request\n",
 304                                   sid_string_dbg(ids[i]->sid)));
 305                         continue;
 306                 }
 307
 308                 /*
 309                  * Check if the domain is around
 310                  */
 311                 domain = wcache_tdc_fetch_domainbysid(talloc_tos(),
 312                                                       &domaincfg.sid);
 313                 if (domain == NULL) {
 314                         DEBUG(10, ("Ignoring unknown domain sid %s\n",
 315                                    sid_string_dbg(&domaincfg.sid)));
 316                         continue;
 317                 }
 318                 TALLOC_FREE(domain);
 319
 320                 domaincfg.globalcfg = global;
 321
 322                 ret = dbwrap_trans_do(autorid_db,
 323                                       idmap_autorid_get_domainrange,
 324                                       &domaincfg);
 325
 326                 if (!NT_STATUS_IS_OK(ret)) {
 327                         DEBUG(3, ("Could not determine range for domain, "
 328                                   "check previous messages for reason\n"));
 329                         goto failure;
 330                 }
 331
 332                 ret = idmap_autorid_sid_to_id(global, &domaincfg, ids[i]);
 333
 334                 if ((!NT_STATUS_IS_OK(ret)) &&
 335                     (!NT_STATUS_EQUAL(ret, NT_STATUS_NONE_MAPPED))) {
 336                         /* some fatal error occurred, log it */
 337                         DEBUG(3, ("Unexpected error resolving a SID (%s)\n",
 338                                   sid_string_dbg(ids[i]->sid)));
 339                         goto failure;
 340                 }
 341         }
 342
 343         talloc_free(ctx);
 344         return NT_STATUS_OK;
 345
 346       failure:
 347         talloc_free(ctx);
 348         return ret;
 349
 350 }
 351
 352 /*
 353  * open and initialize the database which stores the ranges for the domains
 354  */
 355 static NTSTATUS idmap_autorid_db_init(void)
 356 {
 357         int32_t hwm;
 358
 359         if (autorid_db) {
 360                 /* its already open */
 361                 return NT_STATUS_OK;
 362         }
 363
 364         /* Open idmap repository */
 365         autorid_db = db_open(NULL, state_path("autorid.tdb"), 0,
 366                              TDB_DEFAULT, O_RDWR | O_CREAT, 0644);
 367
 368         if (!autorid_db) {
 369                 DEBUG(0, ("Unable to open idmap_autorid database '%s'\n",
 370                           state_path("autorid.tdb")));
 371                 return NT_STATUS_UNSUCCESSFUL;
 372         }
 373
 374         /* Initialize high water mark for the currently used range to 0 */
 375         hwm = dbwrap_fetch_int32(autorid_db, HWM);
 376         if ((hwm < 0)) {
 377                 if (!NT_STATUS_IS_OK
 378                     (dbwrap_trans_store_int32(autorid_db, HWM, 0))) {
 379                         DEBUG(0,
 380                               ("Unable to initialise HWM in autorid "
 381                                "database\n"));
 382                         return NT_STATUS_INTERNAL_DB_ERROR;
 383                 }
 384         }
 385
 386         return NT_STATUS_OK;
 387 }
 388
 389 static struct autorid_global_config *idmap_autorid_loadconfig(TALLOC_CTX * ctx)
 390 {
 391
 392         TDB_DATA data;
 393         struct autorid_global_config *cfg;
 394         unsigned long minvalue, rangesize, maxranges;
 395
 396         data = dbwrap_fetch_bystring(autorid_db, ctx, CONFIGKEY);
 397
 398         if (!data.dptr) {
 399                 DEBUG(10, ("No saved config found\n"));
 400                 return NULL;
 401         }
 402
 403         cfg = TALLOC_ZERO_P(ctx, struct autorid_global_config);
 404         if (!cfg) {
 405                 return NULL;
 406         }
 407
 408         if (sscanf((char *)data.dptr,
 409                    "minvalue:%lu rangesize:%lu maxranges:%lu",
 410                    &minvalue, &rangesize, &maxranges) != 3) {
 411                 DEBUG(1,
 412                       ("Found invalid configuration data"
 413                        "creating new config\n"));
 414                 return NULL;
 415         }
 416
 417         cfg->minvalue = minvalue;
 418         cfg->rangesize = rangesize;
 419         cfg->maxranges = maxranges;
 420
 421         DEBUG(10, ("Loaded previously stored configuration "
 422                    "minvalue:%d rangesize:%d\n",
 423                    cfg->minvalue, cfg->rangesize));
 424
 425         return cfg;
 426
 427 }
 428
 429 static NTSTATUS idmap_autorid_saveconfig(struct autorid_global_config *cfg)
 430 {
 431
 432         NTSTATUS status;
 433         TDB_DATA data;
 434         char *cfgstr;
 435
 436         cfgstr =
 437             talloc_asprintf(talloc_tos(),
 438                             "minvalue:%u rangesize:%u maxranges:%u",
 439                             cfg->minvalue, cfg->rangesize, cfg->maxranges);
 440
 441         if (!cfgstr) {
 442                 return NT_STATUS_NO_MEMORY;
 443         }
 444
 445         data = string_tdb_data(cfgstr);
 446
 447         status = dbwrap_trans_store_bystring(autorid_db, CONFIGKEY,
 448                                              data, TDB_REPLACE);
 449
 450         talloc_free(cfgstr);
 451
 452         return status;
 453 }
 454
 455 static NTSTATUS idmap_autorid_initialize(struct idmap_domain *dom,
 456                                          const char *params)
 457 {
 458         struct autorid_global_config *config;
 459         struct autorid_global_config *storedconfig = NULL;
 460         NTSTATUS status;
 461         uint32_t hwm;
 462
 463         config = TALLOC_ZERO_P(dom, struct autorid_global_config);
 464         if (!config) {
 465                 DEBUG(0, ("Out of memory!\n"));
 466                 return NT_STATUS_NO_MEMORY;
 467         }
 468
 469         status = idmap_autorid_db_init();
 470         if (!NT_STATUS_IS_OK(status)) {
 471                 goto error;
 472         }
 473
 474         config->minvalue = dom->low_id;
 475         config->rangesize = lp_parm_int(-1, "autorid", "rangesize", 100000);
 476
 477         if (config->rangesize < 2000) {
 478                 DEBUG(1, ("autorid rangesize must be at least 2000\n"));
 479                 status = NT_STATUS_INVALID_PARAMETER;
 480                 goto error;
 481         }
 482
 483         config->maxranges = (dom->high_id - dom->low_id + 1) /
 484             config->rangesize;
 485
 486         if (config->maxranges == 0) {
 487                 DEBUG(1, ("allowed uid range is smaller then rangesize, "
 488                           "increase uid range or decrease rangesize\n"));
 489                 status = NT_STATUS_INVALID_PARAMETER;
 490                 goto error;
 491         }
 492
 493         /* check if the high-low limit is a multiple of the rangesize */
 494         if ((dom->high_id - dom->low_id + 1) % config->rangesize != 0) {
 495                 DEBUG(5, ("High uid-low uid difference of %d "
 496                           "is not a multiple of the rangesize %d, "
 497                           "limiting ranges to lower boundary number of %d\n",
 498                           (dom->high_id - dom->low_id + 1), config->rangesize,
 499                           config->maxranges));
 500         }
 501
 502         DEBUG(10, ("Current configuration in config is "
 503                    "minvalue:%d rangesize:%d maxranges:%d\n",
 504                    config->minvalue, config->rangesize, config->maxranges));
 505
 506         /* read previously stored config and current HWM */
 507         storedconfig = idmap_autorid_loadconfig(talloc_tos());
 508
 509         if (!dbwrap_fetch_uint32(autorid_db, HWM, &hwm)) {
 510                 DEBUG(1, ("Fatal error while fetching current "
 511                           "HWM value!\n"));
 512                 status = NT_STATUS_INTERNAL_ERROR;
 513                 goto error;
 514         }
 515
 516         /* did the minimum value or rangesize change? */
 517         if (storedconfig &&
 518             ((storedconfig->minvalue != config->minvalue) ||
 519              (storedconfig->rangesize != config->rangesize))) {
 520                 DEBUG(1, ("New configuration values for rangesize or "
 521                           "minimum uid value conflict with previously "
 522                           "used values! Aborting initialization\n"));
 523                 status = NT_STATUS_INVALID_PARAMETER;
 524                 goto error;
 525         }
 526
 527         /*
 528          * has the highest uid value been reduced to setting that is not
 529          * sufficient any more for already existing ranges?
 530          */
 531         if (hwm > config->maxranges) {
 532                 DEBUG(1, ("New upper uid limit is too low to cover "
 533                           "existing mappings! Aborting initialization\n"));
 534                 status = NT_STATUS_INVALID_PARAMETER;
 535                 goto error;
 536         }
 537
 538         status = idmap_autorid_saveconfig(config);
 539
 540         if (!NT_STATUS_IS_OK(status)) {
 541                 DEBUG(1, ("Failed to store configuration data!\n"));
 542                 goto error;
 543         }
 544
 545         DEBUG(5, ("%d domain ranges with a size of %d are available\n",
 546                   config->maxranges, config->rangesize));
 547
 548         dom->private_data = config;
 549
 550         if (!NT_STATUS_IS_OK(status)) {
 551                 goto error;
 552         }
 553
 554         return NT_STATUS_OK;
 555
 556       error:
 557         talloc_free(config);
 558         talloc_free(storedconfig);
 559
 560         return status;
 561 }
 562
 563 /*
 564   Close the idmap tdb instance
 565 */
 566 static struct idmap_methods autorid_methods = {
 567         .init = idmap_autorid_initialize,
 568         .unixids_to_sids = idmap_autorid_unixids_to_sids,
 569         .sids_to_unixids = idmap_autorid_sids_to_unixids,
 570 };
 571
 572 NTSTATUS idmap_autorid_init(void)
 573 {
 574         return smb_register_idmap(SMB_IDMAP_INTERFACE_VERSION,
 575                                   "autorid", &autorid_methods);
 576 }