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
   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 struct autorid_global_config {
  36         uint32_t minvalue;
  37         uint32_t rangesize;
  38         uint32_t maxranges;
  39 };
  40
  41 struct autorid_domain_config {
  42         struct dom_sid sid;
  43         uint32_t domainnum;
  44         struct autorid_global_config *globalcfg;
  45 };
  46
  47 /* handle to the tdb storing domain <-> range assignments */
  48 static struct db_context *autorid_db;
  49
  50 static NTSTATUS idmap_autorid_get_domainrange(struct db_context *db,
  51                                               void *private_data)
  52 {
  53         NTSTATUS ret;
  54         uint32_t domainnum, hwm;
  55         char *sidstr, *numstr;
  56         struct autorid_domain_config *cfg;
  57
  58         cfg = (struct autorid_domain_config *)private_data;
  59         sidstr = dom_sid_string(talloc_tos(), &(cfg->sid));
  60
  61         if (!sidstr) {
  62                 return NT_STATUS_NO_MEMORY;
  63         }
  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                         goto error;
  73                 }
  74
  75                 /* do we have a range left? */
  76                 if (hwm >= cfg->globalcfg->maxranges) {
  77                         DEBUG(1, ("No more domain ranges available!\n"));
  78                         ret = NT_STATUS_NO_MEMORY;
  79                         goto error;
  80                 }
  81
  82                 /* increase the HWM */
  83                 ret = dbwrap_change_uint32_atomic(db, HWM, &domainnum, 1);
  84                 if (!NT_STATUS_IS_OK(ret)) {
  85                         DEBUG(1, ("Fatal error while fetching a new "
  86                                   "domain range value!\n"));
  87                         goto error;
  88                 }
  89
  90                 /* store away the new mapping in both directions */
  91                 ret = dbwrap_trans_store_uint32(db, sidstr, domainnum);
  92                 if (!NT_STATUS_IS_OK(ret)) {
  93                         DEBUG(1, ("Fatal error while storing new "
  94                                   "domain->range assignment!\n"));
  95                         goto error;
  96                 }
  97
  98                 numstr = talloc_asprintf(db, "%u", domainnum);
  99                 if (!numstr) {
 100                         ret = NT_STATUS_NO_MEMORY;
 101                         goto error;
 102                 }
 103
 104                 ret = dbwrap_trans_store_bystring(db, numstr,
 105                                                   string_term_tdb_data(sidstr),
 106                                                   TDB_INSERT);
 107                 if (!NT_STATUS_IS_OK(ret)) {
 108                         talloc_free(numstr);
 109                         DEBUG(1, ("Fatal error while storing "
 110                                   "new domain->range assignment!\n"));
 111                         goto error;
 112                 }
 113                 talloc_free(numstr);
 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         talloc_free(sidstr);
 122         return NT_STATUS_OK;
 123
 124       error:
 125         talloc_free(sidstr);
 126         return ret;
 127
 128 }
 129
 130 static NTSTATUS idmap_autorid_id_to_sid(TALLOC_CTX * memctx,
 131                                         struct autorid_global_config *cfg,
 132                                         struct id_map *map)
 133 {
 134         uint32_t range;
 135         TDB_DATA data;
 136         char *keystr;
 137         struct dom_sid sid;
 138
 139         /* can this be one of our ids? */
 140         if (map->xid.id < cfg->minvalue) {
 141                 DEBUG(10, ("id %d is lower than minimum value, "
 142                            "ignoring mapping request\n", map->xid.id));
 143                 map->status = ID_UNKNOWN;
 144                 return NT_STATUS_OK;
 145         }
 146
 147         if (map->xid.id > (cfg->minvalue + cfg->rangesize * cfg->maxranges)) {
 148                 DEBUG(10, ("id %d is outside of maximum id value, "
 149                            "ignoring mapping request\n", map->xid.id));
 150                 map->status = ID_UNKNOWN;
 151                 return NT_STATUS_OK;
 152         }
 153
 154         /* determine the range of this uid */
 155         range = ((map->xid.id - cfg->minvalue) / cfg->rangesize);
 156
 157         keystr = talloc_asprintf(memctx, "%u", range);
 158         if (!keystr) {
 159                 return NT_STATUS_NO_MEMORY;
 160         }
 161
 162         data = dbwrap_fetch_bystring(autorid_db, memctx, keystr);
 163
 164         if (!data.dptr) {
 165                 DEBUG(4, ("id %d belongs to range %d which does not have "
 166                           "domain mapping, ignoring mapping request\n",
 167                           map->xid.id, range));
 168         } else {
 169                 string_to_sid(&sid, (const char *)data.dptr);
 170
 171                 sid_compose(map->sid, &sid,
 172                             (map->xid.id - cfg->minvalue -
 173                              range * cfg->rangesize));
 174
 175                 /* We **really** should have some way of validating
 176                    the SID exists and is the correct type here.  But
 177                    that is a deficiency in the idmap_rid design. */
 178
 179                 map->status = ID_MAPPED;
 180         }
 181         return NT_STATUS_OK;
 182 }
 183
 184 /**********************************
 185  Single sid to id lookup function.
 186 **********************************/
 187
 188 static NTSTATUS idmap_autorid_sid_to_id(TALLOC_CTX * memctx,
 189                                         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         TALLOC_CTX *ctx;
 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         ctx = talloc_new(dom);
 237         if (!ctx) {
 238                 DEBUG(0, ("Out of memory!\n"));
 239                 return NT_STATUS_NO_MEMORY;
 240         }
 241
 242         for (i = 0; ids[i]; i++) {
 243
 244                 ret = idmap_autorid_id_to_sid(ctx, globalcfg, ids[i]);
 245
 246                 if ((!NT_STATUS_IS_OK(ret)) &&
 247                     (!NT_STATUS_EQUAL(ret, NT_STATUS_NONE_MAPPED))) {
 248                         /* some fatal error occurred, log it */
 249                         DEBUG(3, ("Unexpected error resolving an ID "
 250                                   " (%d)\n", ids[i]->xid.id));
 251                         goto failure;
 252                 }
 253         }
 254
 255         talloc_free(ctx);
 256         return NT_STATUS_OK;
 257
 258       failure:
 259         talloc_free(ctx);
 260         return ret;
 261
 262 }
 263
 264 /**********************************
 265  lookup a set of sids.
 266 **********************************/
 267
 268 static NTSTATUS idmap_autorid_sids_to_unixids(struct idmap_domain *dom,
 269                                               struct id_map **ids)
 270 {
 271         struct autorid_global_config *global;
 272         struct autorid_domain_config *domaincfg;
 273         struct dom_sid *domainsid;
 274         struct winbindd_tdc_domain *domain;
 275         uint32_t rid;
 276         TALLOC_CTX *ctx;
 277         NTSTATUS ret;
 278         int i;
 279
 280         ctx = talloc_new(dom);
 281         domainsid = talloc(ctx, struct dom_sid);
 282         if (!ctx || !domainsid) {
 283                 DEBUG(0, ("Out of memory!\n"));
 284                 ret = NT_STATUS_NO_MEMORY;
 285                 goto failure;
 286         }
 287
 288         if ((domaincfg = TALLOC_ZERO_P(ctx,
 289                                        struct autorid_domain_config)) == NULL) {
 290                 DEBUG(0, ("Out of memory!\n"));
 291                 ret = NT_STATUS_NO_MEMORY;
 292                 goto failure;
 293         }
 294
 295         /* initialize the status to avoid surprise */
 296         for (i = 0; ids[i]; i++) {
 297                 ids[i]->status = ID_UNKNOWN;
 298         }
 299
 300         global = talloc_get_type(dom->private_data,
 301                                  struct autorid_global_config);
 302
 303         for (i = 0; ids[i]; i++) {
 304                 ZERO_STRUCTP(domainsid);
 305                 sid_copy(domainsid, ids[i]->sid);
 306                 if (!sid_split_rid(domainsid, &rid)) {
 307                         DEBUG(4, ("Could not determine domain SID from %s, "
 308                                   "ignoring mapping request\n",
 309                                   sid_string_dbg(ids[i]->sid)));
 310                         continue;
 311                 }
 312
 313                 domain = wcache_tdc_fetch_domainbysid(ctx, domainsid);
 314                 if (domain == NULL) {
 315                         DEBUG(10, ("Ignoring unknown domain sid %s\n",
 316                                    sid_string_dbg(domainsid)));
 317                         continue;
 318                 }
 319
 320                 ZERO_STRUCTP(domaincfg);
 321                 domaincfg->sid = domain->sid;
 322                 domaincfg->globalcfg = global;
 323
 324                 ret = dbwrap_trans_do(autorid_db, idmap_autorid_get_domainrange,
 325                                       domaincfg);
 326
 327                 if (!NT_STATUS_IS_OK(ret)) {
 328                         DEBUG(3, ("Could not determine range for domain, "
 329                                   "check previous messages for reason\n"));
 330                         goto failure;
 331                 }
 332
 333                 ret = idmap_autorid_sid_to_id(ctx, global, domaincfg, ids[i]);
 334
 335                 if ((!NT_STATUS_IS_OK(ret)) &&
 336                     (!NT_STATUS_EQUAL(ret, NT_STATUS_NONE_MAPPED))) {
 337                         /* some fatal error occurred, log it */
 338                         DEBUG(3, ("Unexpected error resolving a SID (%s)\n",
 339                                   sid_string_dbg(ids[i]->sid)));
 340                         goto failure;
 341                 }
 342         }
 343
 344         talloc_free(ctx);
 345         return NT_STATUS_OK;
 346
 347       failure:
 348         talloc_free(ctx);
 349         return ret;
 350
 351 }
 352
 353 /*
 354  * open and initialize the database which stores the ranges for the domains
 355  */
 356 static NTSTATUS idmap_autorid_db_init(void)
 357 {
 358         int32_t hwm;
 359
 360         if (autorid_db) {
 361                 /* its already open */
 362                 return NT_STATUS_OK;
 363         }
 364
 365         /* Open idmap repository */
 366         autorid_db = db_open(NULL, state_path("autorid.tdb"), 0,
 367                              TDB_DEFAULT, O_RDWR | O_CREAT, 0644);
 368
 369         if (!autorid_db) {
 370                 DEBUG(0, ("Unable to open idmap_autorid database '%s'\n",
 371                           state_path("autorid.tdb")));
 372                 return NT_STATUS_UNSUCCESSFUL;
 373         }
 374
 375         /* Initialize high water mark for the currently used range to 0 */
 376         hwm = dbwrap_fetch_int32(autorid_db, HWM);
 377         if ((hwm < 0)) {
 378                 if (!NT_STATUS_IS_OK
 379                     (dbwrap_trans_store_int32(autorid_db, HWM, 0))) {
 380                         DEBUG(0,
 381                               ("Unable to initialise HWM in autorid "
 382                                "database\n"));
 383                         return NT_STATUS_INTERNAL_DB_ERROR;
 384                 }
 385         }
 386
 387         return NT_STATUS_OK;
 388 }
 389
 390 static NTSTATUS idmap_autorid_initialize(struct idmap_domain *dom,
 391                                          const char *params)
 392 {
 393         struct autorid_global_config *config;
 394         NTSTATUS status;
 395
 396         config = TALLOC_ZERO_P(dom, struct autorid_global_config);
 397         if (!config) {
 398                 DEBUG(0, ("Out of memory!\n"));
 399                 return NT_STATUS_NO_MEMORY;
 400         }
 401
 402         status = idmap_autorid_db_init();
 403         if (!NT_STATUS_IS_OK(status)) {
 404                 goto error;
 405         }
 406
 407         config->minvalue = dom->low_id;
 408         config->rangesize = lp_parm_int(-1, "autorid", "rangesize", 100000);
 409
 410         if (config->rangesize < 2000) {
 411                 DEBUG(1, ("autorid rangesize must be at least 2000\n"));
 412                 status = NT_STATUS_INVALID_PARAMETER;
 413                 goto error;
 414         }
 415
 416         config->maxranges = (dom->high_id - dom->low_id + 1) /
 417             config->rangesize;
 418
 419         if (config->maxranges == 0) {
 420                 DEBUG(1, ("allowed uid range is smaller then rangesize, "
 421                           "increase uid range or decrease rangesize\n"));
 422                 status = NT_STATUS_INVALID_PARAMETER;
 423                 goto error;
 424         }
 425
 426         /* check if the high-low limit is a multiple of the rangesize */
 427         if ((dom->high_id - dom->low_id + 1) % config->rangesize != 0) {
 428                 DEBUG(5, ("High uid-low uid difference of %d "
 429                           "is not a multiple of the rangesize %d, "
 430                           "limiting ranges to lower boundary number of %d\n",
 431                           (dom->high_id - dom->low_id + 1), config->rangesize,
 432                           config->maxranges));
 433         }
 434
 435         DEBUG(5, ("%d domain ranges with a size of %d are available\n",
 436                   config->maxranges, config->rangesize));
 437
 438         dom->private_data = config;
 439
 440         if (!NT_STATUS_IS_OK(status)) {
 441                 goto error;
 442         }
 443
 444         return NT_STATUS_OK;
 445
 446       error:
 447         talloc_free(config);
 448         return status;
 449 }
 450
 451 /*
 452   Close the idmap tdb instance
 453 */
 454 static NTSTATUS idmap_autorid_close(struct idmap_domain *dom)
 455 {
 456         /* don't do anything */
 457         return NT_STATUS_OK;
 458 }
 459
 460 static struct idmap_methods autorid_methods = {
 461         .init = idmap_autorid_initialize,
 462         .unixids_to_sids = idmap_autorid_unixids_to_sids,
 463         .sids_to_unixids = idmap_autorid_sids_to_unixids,
 464         .close_fn = idmap_autorid_close
 465 };
 466
 467 NTSTATUS idmap_autorid_init(void)
 468 {
 469         return smb_register_idmap(SMB_IDMAP_INTERFACE_VERSION,
 470                                   "autorid", &autorid_methods);
 471 }