source/winbindd/idmap_hash/idmap_hash.c

   1 /*
   2  *  idmap_hash.c
   3  *
   4  * Copyright (C) Gerald Carter  <jerry@samba.org>      2007 - 2008
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  18  *
  19  */
  20
  21 #include "includes.h"
  22 #include "winbindd/winbindd.h"
  23 #include "idmap_hash.h"
  24
  25 #undef DBGC_CLASS
  26 #define DBGC_CLASS DBGC_IDMAP
  27
  28 struct sid_hash_table {
  29         DOM_SID *sid;
  30 };
  31
  32 struct sid_hash_table *hashed_domains = NULL;
  33
  34 /*********************************************************************
  35  Hash a domain SID (S-1-5-12-aaa-bbb-ccc) to a 12bit number
  36  ********************************************************************/
  37
  38 static uint32_t hash_domain_sid(const DOM_SID *sid)
  39 {
  40         uint32_t hash;
  41
  42         if (sid->num_auths != 4)
  43                 return 0;
  44
  45         /* XOR the last three subauths */
  46
  47         hash = ((sid->sub_auths[1] ^ sid->sub_auths[2]) ^ sid->sub_auths[3]);
  48
  49         /* Take all 32-bits into account when generating the 12-bit
  50            hash value */
  51         hash = (((hash & 0xFFF00000) >> 20)
  52                 + ((hash & 0x000FFF00) >> 8)
  53                 + (hash & 0x000000FF)) & 0x0000FFF;
  54
  55         /* return a 12-bit hash value */
  56
  57         return hash;
  58 }
  59
  60 /*********************************************************************
  61  Hash a Relative ID to a 20 bit number
  62  ********************************************************************/
  63
  64 static uint32_t hash_rid(uint32_t rid)
  65 {
  66         /* 20 bits for the rid which allows us to support
  67            the first 100K users/groups in a domain */
  68
  69         return (rid & 0x0007FFFF);
  70 }
  71
  72 /*********************************************************************
  73  ********************************************************************/
  74
  75 static uint32_t combine_hashes(uint32_t h_domain,
  76                                uint32_t h_rid)
  77 {
  78         uint32_t return_id = 0;
  79
  80         /* shift the hash_domain 19 bits to the left and OR with the
  81            hash_rid */
  82
  83         return_id = ((h_domain<<19) | h_rid);
  84
  85         return return_id;
  86 }
  87
  88 /*********************************************************************
  89  ********************************************************************/
  90
  91 static void separate_hashes(uint32_t id,
  92                             uint32_t *h_domain,
  93                             uint32_t *h_rid)
  94 {
  95         *h_rid = id & 0x0007FFFF;
  96         *h_domain = (id & 0x7FF80000) >> 19;
  97
  98         return;
  99 }
 100
 101
 102 /*********************************************************************
 103  ********************************************************************/
 104
 105 static NTSTATUS be_init(struct idmap_domain *dom,
 106                         const char *params)
 107 {
 108         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 109         struct winbindd_tdc_domain *dom_list = NULL;
 110         size_t num_domains = 0;
 111         int i;
 112
 113         /* If the domain SID hash talbe has been initialized, assume
 114            that we completed this function previously */
 115
 116         if ( hashed_domains ) {
 117                 nt_status = NT_STATUS_OK;
 118                 goto done;
 119         }
 120
 121         if (!wcache_tdc_fetch_list(&dom_list, &num_domains)) {
 122                 nt_status = NT_STATUS_TRUSTED_DOMAIN_FAILURE;
 123                 BAIL_ON_NTSTATUS_ERROR(nt_status);
 124         }
 125
 126         /* Create the hash table of domain SIDs */
 127
 128         hashed_domains = TALLOC_ZERO_ARRAY(NULL, struct sid_hash_table, 4096);
 129         BAIL_ON_PTR_NT_ERROR(hashed_domains, nt_status);
 130
 131         /* create the hash table of domain SIDs */
 132
 133         for (i=0; i<num_domains; i++) {
 134                 uint32_t hash;
 135
 136                 if (is_null_sid(&dom_list[i].sid))
 137                         continue;
 138                 if ((hash = hash_domain_sid(&dom_list[i].sid)) == 0)
 139                         continue;
 140
 141                 DEBUG(5,("hash:be_init() Adding %s (%s) -> %d\n",
 142                          dom_list[i].domain_name,
 143                          sid_string_dbg(&dom_list[i].sid),
 144                          hash));
 145
 146                 hashed_domains[hash].sid = talloc(hashed_domains, DOM_SID);
 147                 sid_copy(hashed_domains[hash].sid, &dom_list[i].sid);
 148         }
 149
 150 done:
 151         return nt_status;
 152 }
 153
 154 /*********************************************************************
 155  ********************************************************************/
 156
 157 static NTSTATUS unixids_to_sids(struct idmap_domain *dom,
 158                                 struct id_map **ids)
 159 {
 160         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 161         int i;
 162
 163         nt_status = be_init(dom, NULL);
 164         BAIL_ON_NTSTATUS_ERROR(nt_status);
 165
 166         if (!ids) {
 167                 nt_status = NT_STATUS_INVALID_PARAMETER;
 168                 BAIL_ON_NTSTATUS_ERROR(nt_status);
 169         }
 170
 171         for (i=0; ids[i]; i++) {
 172                 uint32_t h_domain, h_rid;
 173
 174                 ids[i]->status = ID_UNMAPPED;
 175
 176                 separate_hashes(ids[i]->xid.id, &h_domain, &h_rid);
 177
 178                 /* Make sure the caller allocated memor for us */
 179
 180                 if (!ids[i]->sid) {
 181                         nt_status = NT_STATUS_INVALID_PARAMETER;
 182                         BAIL_ON_NTSTATUS_ERROR(nt_status);
 183                 }
 184
 185                 /* If the domain hash doesn't find a SID in the table,
 186                    skip it */
 187
 188                 if (!hashed_domains[h_domain].sid)
 189                         continue;
 190
 191                 sid_copy(ids[i]->sid, hashed_domains[h_domain].sid);
 192                 sid_append_rid(ids[i]->sid, h_rid);
 193                 ids[i]->status = ID_MAPPED;
 194         }
 195
 196 done:
 197         return nt_status;
 198 }
 199
 200 /*********************************************************************
 201  ********************************************************************/
 202
 203 static NTSTATUS sids_to_unixids(struct idmap_domain *dom,
 204                                 struct id_map **ids)
 205 {
 206         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 207         int i;
 208
 209         nt_status = be_init(dom, NULL);
 210         BAIL_ON_NTSTATUS_ERROR(nt_status);
 211
 212         if (!ids) {
 213                 nt_status = NT_STATUS_INVALID_PARAMETER;
 214                 BAIL_ON_NTSTATUS_ERROR(nt_status);
 215         }
 216
 217         for (i=0; ids[i]; i++) {
 218                 DOM_SID sid;
 219                 uint32_t rid;
 220                 uint32_t h_domain, h_rid;
 221
 222                 ids[i]->status = ID_UNMAPPED;
 223
 224                 sid_copy(&sid, ids[i]->sid);
 225                 sid_split_rid(&sid, &rid);
 226
 227                 h_domain = hash_domain_sid(&sid);
 228                 h_rid = hash_rid(rid);
 229
 230                 /* Check that both hashes are non-zero*/
 231
 232                 if (h_domain && h_rid) {
 233                         ids[i]->xid.id = combine_hashes(h_domain, h_rid);
 234                         ids[i]->status = ID_MAPPED;
 235                 }
 236         }
 237
 238 done:
 239         return nt_status;
 240 }
 241
 242 /*********************************************************************
 243  ********************************************************************/
 244
 245 static NTSTATUS be_close(struct idmap_domain *dom)
 246 {
 247         if (hashed_domains)
 248                 talloc_free(hashed_domains);
 249
 250         return NT_STATUS_OK;
 251 }
 252
 253 /*********************************************************************
 254  ********************************************************************/
 255
 256 static NTSTATUS nss_hash_init(struct nss_domain_entry *e )
 257 {
 258         return be_init(NULL, NULL);
 259 }
 260
 261 /**********************************************************************
 262  *********************************************************************/
 263
 264 static NTSTATUS nss_hash_get_info(struct nss_domain_entry *e,
 265                                     const DOM_SID *sid,
 266                                     TALLOC_CTX *ctx,
 267                                     ADS_STRUCT *ads,
 268                                     LDAPMessage *msg,
 269                                     char **homedir,
 270                                     char **shell,
 271                                     char **gecos,
 272                                     gid_t *p_gid )
 273 {
 274         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 275
 276         nt_status = nss_hash_init(e);
 277         BAIL_ON_NTSTATUS_ERROR(nt_status);
 278
 279         if (!homedir || !shell || !gecos) {
 280                 nt_status = NT_STATUS_INVALID_PARAMETER;
 281                 BAIL_ON_NTSTATUS_ERROR(nt_status);
 282         }
 283
 284         *homedir = talloc_strdup(ctx, lp_template_homedir());
 285         BAIL_ON_PTR_NT_ERROR(*homedir, nt_status);
 286
 287         *shell   = talloc_strdup(ctx, lp_template_shell());
 288         BAIL_ON_PTR_NT_ERROR(*shell, nt_status);
 289
 290         *gecos   = NULL;
 291
 292         /* Initialize the gid so that the upper layer fills
 293            in the proper Windows primary group */
 294
 295         if (*p_gid) {
 296                 *p_gid = (gid_t)-1;
 297         }
 298
 299 done:
 300         return nt_status;
 301 }
 302
 303 /**********************************************************************
 304  *********************************************************************/
 305
 306 static NTSTATUS nss_hash_map_to_alias(TALLOC_CTX *mem_ctx,
 307                                         const char *domain,
 308                                         const char *name,
 309                                         char **alias)
 310 {
 311         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 312         const char *value;
 313
 314         value = talloc_asprintf(mem_ctx, "%s\\%s", domain, name);
 315         BAIL_ON_PTR_NT_ERROR(value, nt_status);
 316
 317         nt_status = mapfile_lookup_key(mem_ctx, value, alias);
 318         BAIL_ON_NTSTATUS_ERROR(nt_status);
 319
 320 done:
 321         return nt_status;
 322 }
 323
 324 /**********************************************************************
 325  *********************************************************************/
 326
 327 static NTSTATUS nss_hash_map_from_alias(TALLOC_CTX *mem_ctx,
 328                                           const char *domain,
 329                                           const char *alias,
 330                                           char **name)
 331 {
 332         return mapfile_lookup_value(mem_ctx, alias, name);
 333 }
 334
 335 /**********************************************************************
 336  *********************************************************************/
 337
 338 static NTSTATUS nss_hash_close(void)
 339 {
 340         return NT_STATUS_OK;
 341 }
 342
 343 /*********************************************************************
 344  Dispatch Tables for IDMap and NssInfo Methods
 345 ********************************************************************/
 346
 347 static struct idmap_methods hash_idmap_methods = {
 348         .init            = be_init,
 349         .unixids_to_sids = unixids_to_sids,
 350         .sids_to_unixids = sids_to_unixids,
 351         .close_fn        = be_close
 352 };
 353
 354 static struct nss_info_methods hash_nss_methods = {
 355         .init           = nss_hash_init,
 356         .get_nss_info   = nss_hash_get_info,
 357         .map_to_alias   = nss_hash_map_to_alias,
 358         .map_from_alias = nss_hash_map_from_alias,
 359         .close_fn       = nss_hash_close
 360 };
 361
 362 /**********************************************************************
 363  Register with the idmap and idmap_nss subsystems. We have to protect
 364  against the idmap and nss_info interfaces being in a half-registered
 365  state.
 366  **********************************************************************/
 367
 368 NTSTATUS idmap_hash_init(void)
 369 {
 370         static NTSTATUS idmap_status = NT_STATUS_UNSUCCESSFUL;
 371         static NTSTATUS nss_status = NT_STATUS_UNSUCCESSFUL;
 372
 373         if ( !NT_STATUS_IS_OK(idmap_status) ) {
 374                 idmap_status =  smb_register_idmap(SMB_IDMAP_INTERFACE_VERSION,
 375                                                    "hash", &hash_idmap_methods);
 376
 377                 if ( !NT_STATUS_IS_OK(idmap_status) ) {
 378                         DEBUG(0,("Failed to register hash idmap plugin.\n"));
 379                         return idmap_status;
 380                 }
 381         }
 382
 383         if ( !NT_STATUS_IS_OK(nss_status) ) {
 384                 nss_status = smb_register_idmap_nss(SMB_NSS_INFO_INTERFACE_VERSION,
 385                                                     "hash", &hash_nss_methods);
 386                 if ( !NT_STATUS_IS_OK(nss_status) ) {
 387                         DEBUG(0,("Failed to register hash idmap nss plugin.\n"));
 388                         return nss_status;
 389                 }
 390         }
 391
 392         return NT_STATUS_OK;
 393 }