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                         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                 if (!NT_STATUS_IS_OK(ret)) {
 109                         talloc_free(numstr);
 110                         DEBUG(1, ("Fatal error while storing "
 111                                   "new domain->range assignment!\n"));
 112                         goto error;
 113                 }
 114                 talloc_free(numstr);
 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         talloc_free(sidstr);
 123         return NT_STATUS_OK;
 124
 125       error:
 126         talloc_free(sidstr);
 127         return ret;
 128
 129 }
 130
 131 static NTSTATUS idmap_autorid_id_to_sid(TALLOC_CTX * memctx,
 132                                         struct autorid_global_config *cfg,
 133                                         struct id_map *map)
 134 {
 135         uint32_t range;
 136         TDB_DATA data;
 137         char *keystr;
 138         struct dom_sid sid;
 139
 140         /* can this be one of our ids? */
 141         if (map->xid.id < cfg->minvalue) {
 142                 DEBUG(10, ("id %d is lower than minimum value, "
 143                            "ignoring mapping request\n", map->xid.id));
 144                 map->status = ID_UNKNOWN;
 145                 return NT_STATUS_OK;
 146         }
 147
 148         if (map->xid.id > (cfg->minvalue + cfg->rangesize * cfg->maxranges)) {
 149                 DEBUG(10, ("id %d is outside of maximum id value, "
 150                            "ignoring mapping request\n", map->xid.id));
 151                 map->status = ID_UNKNOWN;
 152                 return NT_STATUS_OK;
 153         }
 154
 155         /* determine the range of this uid */
 156         range = ((map->xid.id - cfg->minvalue) / cfg->rangesize);
 157
 158         keystr = talloc_asprintf(memctx, "%u", range);
 159         if (!keystr) {
 160                 return NT_STATUS_NO_MEMORY;
 161         }
 162
 163         data = dbwrap_fetch_bystring(autorid_db, memctx, keystr);
 164
 165         if (!data.dptr) {
 166                 DEBUG(4, ("id %d belongs to range %d which does not have "
 167                           "domain mapping, ignoring mapping request\n",
 168                           map->xid.id, range));
 169         } else {
 170                 string_to_sid(&sid, (const char *)data.dptr);
 171
 172                 sid_compose(map->sid, &sid,
 173                             (map->xid.id - cfg->minvalue -
 174                              range * cfg->rangesize));
 175
 176                 /* We **really** should have some way of validating
 177                    the SID exists and is the correct type here.  But
 178                    that is a deficiency in the idmap_rid design. */
 179
 180                 map->status = ID_MAPPED;
 181         }
 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(TALLOC_CTX * memctx,
 190                                         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         TALLOC_CTX *ctx;
 226         NTSTATUS ret;
 227         int i;
 228
 229         /* initialize the status to avoid surprise */
 230         for (i = 0; ids[i]; i++) {
 231                 ids[i]->status = ID_UNKNOWN;
 232         }
 233
 234         globalcfg = talloc_get_type(dom->private_data,
 235                                     struct autorid_global_config);
 236
 237         ctx = talloc_new(dom);
 238         if (!ctx) {
 239                 DEBUG(0, ("Out of memory!\n"));
 240                 return NT_STATUS_NO_MEMORY;
 241         }
 242
 243         for (i = 0; ids[i]; i++) {
 244
 245                 ret = idmap_autorid_id_to_sid(ctx, globalcfg, ids[i]);
 246
 247                 if ((!NT_STATUS_IS_OK(ret)) &&
 248                     (!NT_STATUS_EQUAL(ret, NT_STATUS_NONE_MAPPED))) {
 249                         /* some fatal error occurred, log it */
 250                         DEBUG(3, ("Unexpected error resolving an ID "
 251                                   " (%d)\n", ids[i]->xid.id));
 252                         goto failure;
 253                 }
 254         }
 255
 256         talloc_free(ctx);
 257         return NT_STATUS_OK;
 258
 259       failure:
 260         talloc_free(ctx);
 261         return ret;
 262
 263 }
 264
 265 /**********************************
 266  lookup a set of sids.
 267 **********************************/
 268
 269 static NTSTATUS idmap_autorid_sids_to_unixids(struct idmap_domain *dom,
 270                                               struct id_map **ids)
 271 {
 272         struct autorid_global_config *global;
 273         struct autorid_domain_config *domaincfg;
 274         struct dom_sid *domainsid;
 275         struct winbindd_tdc_domain *domain;
 276         uint32_t rid;
 277         TALLOC_CTX *ctx;
 278         NTSTATUS ret;
 279         int i;
 280
 281         ctx = talloc_new(dom);
 282         domainsid = talloc(ctx, struct dom_sid);
 283         if (!ctx || !domainsid) {
 284                 DEBUG(0, ("Out of memory!\n"));
 285                 ret = NT_STATUS_NO_MEMORY;
 286                 goto failure;
 287         }
 288
 289         if ((domaincfg = TALLOC_ZERO_P(ctx,
 290                                        struct autorid_domain_config)) == NULL) {
 291                 DEBUG(0, ("Out of memory!\n"));
 292                 ret = NT_STATUS_NO_MEMORY;
 293                 goto failure;
 294         }
 295
 296         /* initialize the status to avoid surprise */
 297         for (i = 0; ids[i]; i++) {
 298                 ids[i]->status = ID_UNKNOWN;
 299         }
 300
 301         global = talloc_get_type(dom->private_data,
 302                                  struct autorid_global_config);
 303
 304         for (i = 0; ids[i]; i++) {
 305                 ZERO_STRUCTP(domainsid);
 306                 sid_copy(domainsid, ids[i]->sid);
 307                 if (!sid_split_rid(domainsid, &rid)) {
 308                         DEBUG(4, ("Could not determine domain SID from %s, "
 309                                   "ignoring mapping request\n",
 310                                   sid_string_dbg(ids[i]->sid)));
 311                         continue;
 312                 }
 313
 314                 domain = wcache_tdc_fetch_domainbysid(ctx, domainsid);
 315                 if (domain == NULL) {
 316                         DEBUG(10, ("Ignoring unknown domain sid %s\n",
 317                                    sid_string_dbg(domainsid)));
 318                         continue;
 319                 }
 320
 321                 ZERO_STRUCTP(domaincfg);
 322                 domaincfg->sid = domain->sid;
 323                 domaincfg->globalcfg = global;
 324
 325                 ret = dbwrap_trans_do(autorid_db, idmap_autorid_get_domainrange,
 326                                       domaincfg);
 327
 328                 if (!NT_STATUS_IS_OK(ret)) {
 329                         DEBUG(3, ("Could not determine range for domain, "
 330                                   "check previous messages for reason\n"));
 331                         goto failure;
 332                 }
 333
 334                 ret = idmap_autorid_sid_to_id(ctx, global, domaincfg, ids[i]);
 335
 336                 if ((!NT_STATUS_IS_OK(ret)) &&
 337                     (!NT_STATUS_EQUAL(ret, NT_STATUS_NONE_MAPPED))) {
 338                         /* some fatal error occurred, log it */
 339                         DEBUG(3, ("Unexpected error resolving a SID (%s)\n",
 340                                   sid_string_dbg(ids[i]->sid)));
 341                         goto failure;
 342                 }
 343         }
 344
 345         talloc_free(ctx);
 346         return NT_STATUS_OK;
 347
 348       failure:
 349         talloc_free(ctx);
 350         return ret;
 351
 352 }
 353
 354 /*
 355  * open and initialize the database which stores the ranges for the domains
 356  */
 357 static NTSTATUS idmap_autorid_db_init(void)
 358 {
 359         int32_t hwm;
 360
 361         if (autorid_db) {
 362                 /* its already open */
 363                 return NT_STATUS_OK;
 364         }
 365
 366         /* Open idmap repository */
 367         autorid_db = db_open(NULL, state_path("autorid.tdb"), 0,
 368                              TDB_DEFAULT, O_RDWR | O_CREAT, 0644);
 369
 370         if (!autorid_db) {
 371                 DEBUG(0, ("Unable to open idmap_autorid database '%s'\n",
 372                           state_path("autorid.tdb")));
 373                 return NT_STATUS_UNSUCCESSFUL;
 374         }
 375
 376         /* Initialize high water mark for the currently used range to 0 */
 377         hwm = dbwrap_fetch_int32(autorid_db, HWM);
 378         if ((hwm < 0)) {
 379                 if (!NT_STATUS_IS_OK
 380                     (dbwrap_trans_store_int32(autorid_db, HWM, 0))) {
 381                         DEBUG(0,
 382                               ("Unable to initialise HWM in autorid "
 383                                "database\n"));
 384                         return NT_STATUS_INTERNAL_DB_ERROR;
 385                 }
 386         }
 387
 388         return NT_STATUS_OK;
 389 }
 390
 391 static NTSTATUS idmap_autorid_initialize(struct idmap_domain *dom,
 392                                          const char *params)
 393 {
 394         struct autorid_global_config *config;
 395         NTSTATUS status;
 396
 397         config = TALLOC_ZERO_P(dom, struct autorid_global_config);
 398         if (!config) {
 399                 DEBUG(0, ("Out of memory!\n"));
 400                 return NT_STATUS_NO_MEMORY;
 401         }
 402
 403         status = idmap_autorid_db_init();
 404         if (!NT_STATUS_IS_OK(status)) {
 405                 goto error;
 406         }
 407
 408         config->minvalue = dom->low_id;
 409         config->rangesize = lp_parm_int(-1, "autorid", "rangesize", 100000);
 410
 411         if (config->rangesize < 2000) {
 412                 DEBUG(1, ("autorid rangesize must be at least 2000\n"));
 413                 status = NT_STATUS_INVALID_PARAMETER;
 414                 goto error;
 415         }
 416
 417         config->maxranges = (dom->high_id - dom->low_id + 1) /
 418             config->rangesize;
 419
 420         if (config->maxranges == 0) {
 421                 DEBUG(1, ("allowed uid range is smaller then rangesize, "
 422                           "increase uid range or decrease rangesize\n"));
 423                 status = NT_STATUS_INVALID_PARAMETER;
 424                 goto error;
 425         }
 426
 427         /* check if the high-low limit is a multiple of the rangesize */
 428         if ((dom->high_id - dom->low_id + 1) % config->rangesize != 0) {
 429                 DEBUG(5, ("High uid-low uid difference of %d "
 430                           "is not a multiple of the rangesize %d, "
 431                           "limiting ranges to lower boundary number of %d\n",
 432                           (dom->high_id - dom->low_id + 1), config->rangesize,
 433                           config->maxranges));
 434         }
 435
 436         DEBUG(5, ("%d domain ranges with a size of %d are available\n",
 437                   config->maxranges, config->rangesize));
 438
 439         dom->private_data = config;
 440
 441         if (!NT_STATUS_IS_OK(status)) {
 442                 goto error;
 443         }
 444
 445         return NT_STATUS_OK;
 446
 447       error:
 448         talloc_free(config);
 449         return status;
 450 }
 451
 452 /*
 453   Close the idmap tdb instance
 454 */
 455 static NTSTATUS idmap_autorid_close(struct idmap_domain *dom)
 456 {
 457         /* don't do anything */
 458         return NT_STATUS_OK;
 459 }
 460
 461 static struct idmap_methods autorid_methods = {
 462         .init = idmap_autorid_initialize,
 463         .unixids_to_sids = idmap_autorid_unixids_to_sids,
 464         .sids_to_unixids = idmap_autorid_sids_to_unixids,
 465         .close_fn = idmap_autorid_close
 466 };
 467
 468 NTSTATUS idmap_autorid_init(void)
 469 {
 470         return smb_register_idmap(SMB_IDMAP_INTERFACE_VERSION,
 471                                   "autorid", &autorid_methods);
 472 }