source3/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.h"
  24 #include "idmap_hash.h"
  25 #include "ads.h"
  26 #include "nss_info.h"
  27 #include "../libcli/security/dom_sid.h"
  28
  29 #undef DBGC_CLASS
  30 #define DBGC_CLASS DBGC_IDMAP
  31
  32 struct sid_hash_table {
  33         struct dom_sid *sid;
  34 };
  35
  36 /*********************************************************************
  37  Hash a domain SID (S-1-5-12-aaa-bbb-ccc) to a 12bit number
  38  ********************************************************************/
  39
  40 static uint32_t hash_domain_sid(const struct dom_sid *sid)
  41 {
  42         uint32_t hash;
  43
  44         if (sid->num_auths != 4)
  45                 return 0;
  46
  47         /* XOR the last three subauths */
  48
  49         hash = ((sid->sub_auths[1] ^ sid->sub_auths[2]) ^ sid->sub_auths[3]);
  50
  51         /* Take all 32-bits into account when generating the 12-bit
  52            hash value */
  53         hash = (((hash & 0xFFF00000) >> 20)
  54                 + ((hash & 0x000FFF00) >> 8)
  55                 + (hash & 0x000000FF)) & 0x0000FFF;
  56
  57         /* return a 12-bit hash value */
  58
  59         return hash;
  60 }
  61
  62 /*********************************************************************
  63  Hash a Relative ID to a 20 bit number
  64  ********************************************************************/
  65
  66 static uint32_t hash_rid(uint32_t rid)
  67 {
  68         /* 20 bits for the rid which allows us to support
  69            the first 100K users/groups in a domain */
  70
  71         return (rid & 0x0007FFFF);
  72 }
  73
  74 /*********************************************************************
  75  ********************************************************************/
  76
  77 static uint32_t combine_hashes(uint32_t h_domain,
  78                                uint32_t h_rid)
  79 {
  80         uint32_t return_id = 0;
  81
  82         /* shift the hash_domain 19 bits to the left and OR with the
  83            hash_rid */
  84
  85         return_id = ((h_domain<<19) | h_rid);
  86
  87         return return_id;
  88 }
  89
  90 /*********************************************************************
  91  ********************************************************************/
  92
  93 static void separate_hashes(uint32_t id,
  94                             uint32_t *h_domain,
  95                             uint32_t *h_rid)
  96 {
  97         *h_rid = id & 0x0007FFFF;
  98         *h_domain = (id & 0x7FF80000) >> 19;
  99
 100         return;
 101 }
 102
 103
 104 /*********************************************************************
 105  ********************************************************************/
 106
 107 static NTSTATUS be_init(struct idmap_domain *dom)
 108 {
 109         struct sid_hash_table *hashed_domains;
 110         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 111         struct winbindd_tdc_domain *dom_list = NULL;
 112         size_t num_domains = 0;
 113         int i;
 114
 115         /* If the domain SID hash table has been initialized, assume
 116            that we completed this function previously */
 117
 118         if (dom->private_data != NULL) {
 119                 nt_status = NT_STATUS_OK;
 120                 goto done;
 121         }
 122
 123         if (!wcache_tdc_fetch_list(&dom_list, &num_domains)) {
 124                 nt_status = NT_STATUS_TRUSTED_DOMAIN_FAILURE;
 125                 BAIL_ON_NTSTATUS_ERROR(nt_status);
 126         }
 127
 128         /* Create the hash table of domain SIDs */
 129
 130         hashed_domains = talloc_zero_array(dom, struct sid_hash_table, 4096);
 131         BAIL_ON_PTR_NT_ERROR(hashed_domains, nt_status);
 132
 133         /* create the hash table of domain SIDs */
 134
 135         for (i=0; i<num_domains; i++) {
 136                 uint32_t hash;
 137
 138                 if (is_null_sid(&dom_list[i].sid))
 139                         continue;
 140                 if ((hash = hash_domain_sid(&dom_list[i].sid)) == 0)
 141                         continue;
 142
 143                 DEBUG(5,("hash:be_init() Adding %s (%s) -> %d\n",
 144                          dom_list[i].domain_name,
 145                          sid_string_dbg(&dom_list[i].sid),
 146                          hash));
 147
 148                 hashed_domains[hash].sid = talloc(hashed_domains, struct dom_sid);
 149                 sid_copy(hashed_domains[hash].sid, &dom_list[i].sid);
 150         }
 151
 152         dom->private_data = hashed_domains;
 153
 154 done:
 155         return nt_status;
 156 }
 157
 158 /*********************************************************************
 159  ********************************************************************/
 160
 161 static NTSTATUS unixids_to_sids(struct idmap_domain *dom,
 162                                 struct id_map **ids)
 163 {
 164         struct sid_hash_table *hashed_domains = talloc_get_type_abort(
 165                 dom->private_data, struct sid_hash_table);
 166         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 167         int i;
 168
 169         if (!ids) {
 170                 nt_status = NT_STATUS_INVALID_PARAMETER;
 171                 BAIL_ON_NTSTATUS_ERROR(nt_status);
 172         }
 173
 174         /* initialize the status to avoid suprise */
 175         for (i = 0; ids[i]; i++) {
 176                 ids[i]->status = ID_UNKNOWN;
 177         }
 178
 179         nt_status = be_init(dom);
 180         BAIL_ON_NTSTATUS_ERROR(nt_status);
 181
 182         for (i=0; ids[i]; i++) {
 183                 uint32_t h_domain, h_rid;
 184
 185                 ids[i]->status = ID_UNMAPPED;
 186
 187                 separate_hashes(ids[i]->xid.id, &h_domain, &h_rid);
 188
 189                 /* Make sure the caller allocated memor for us */
 190
 191                 if (!ids[i]->sid) {
 192                         nt_status = NT_STATUS_INVALID_PARAMETER;
 193                         BAIL_ON_NTSTATUS_ERROR(nt_status);
 194                 }
 195
 196                 /* If the domain hash doesn't find a SID in the table,
 197                    skip it */
 198
 199                 if (!hashed_domains[h_domain].sid)
 200                         continue;
 201
 202                 sid_compose(ids[i]->sid, hashed_domains[h_domain].sid, h_rid);
 203                 ids[i]->status = ID_MAPPED;
 204         }
 205
 206 done:
 207         return nt_status;
 208 }
 209
 210 /*********************************************************************
 211  ********************************************************************/
 212
 213 static NTSTATUS sids_to_unixids(struct idmap_domain *dom,
 214                                 struct id_map **ids)
 215 {
 216         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 217         int i;
 218
 219         if (!ids) {
 220                 nt_status = NT_STATUS_INVALID_PARAMETER;
 221                 BAIL_ON_NTSTATUS_ERROR(nt_status);
 222         }
 223
 224         /* initialize the status to avoid suprise */
 225         for (i = 0; ids[i]; i++) {
 226                 ids[i]->status = ID_UNKNOWN;
 227         }
 228
 229         nt_status = be_init(dom);
 230         BAIL_ON_NTSTATUS_ERROR(nt_status);
 231
 232         for (i=0; ids[i]; i++) {
 233                 struct dom_sid sid;
 234                 uint32_t rid;
 235                 uint32_t h_domain, h_rid;
 236
 237                 ids[i]->status = ID_UNMAPPED;
 238
 239                 sid_copy(&sid, ids[i]->sid);
 240                 sid_split_rid(&sid, &rid);
 241
 242                 h_domain = hash_domain_sid(&sid);
 243                 h_rid = hash_rid(rid);
 244
 245                 /* Check that both hashes are non-zero*/
 246
 247                 if (h_domain && h_rid) {
 248                         ids[i]->xid.id = combine_hashes(h_domain, h_rid);
 249                         ids[i]->status = ID_MAPPED;
 250                 }
 251         }
 252
 253 done:
 254         return nt_status;
 255 }
 256
 257 /*********************************************************************
 258  ********************************************************************/
 259
 260 static NTSTATUS nss_hash_init(struct nss_domain_entry *e )
 261 {
 262         return NT_STATUS_OK;
 263 }
 264
 265 /**********************************************************************
 266  *********************************************************************/
 267
 268 static NTSTATUS nss_hash_get_info(struct nss_domain_entry *e,
 269                                     const struct dom_sid *sid,
 270                                     TALLOC_CTX *ctx,
 271                                     const char **homedir,
 272                                     const char **shell,
 273                                     const char **gecos,
 274                                     gid_t *p_gid )
 275 {
 276         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 277
 278         nt_status = nss_hash_init(e);
 279         BAIL_ON_NTSTATUS_ERROR(nt_status);
 280
 281         if (!homedir || !shell || !gecos) {
 282                 nt_status = NT_STATUS_INVALID_PARAMETER;
 283                 BAIL_ON_NTSTATUS_ERROR(nt_status);
 284         }
 285
 286         *homedir = talloc_strdup(ctx, lp_template_homedir());
 287         BAIL_ON_PTR_NT_ERROR(*homedir, nt_status);
 288
 289         *shell   = talloc_strdup(ctx, lp_template_shell());
 290         BAIL_ON_PTR_NT_ERROR(*shell, nt_status);
 291
 292         *gecos   = NULL;
 293
 294         /* Initialize the gid so that the upper layer fills
 295            in the proper Windows primary group */
 296
 297         if (*p_gid) {
 298                 *p_gid = (gid_t)-1;
 299         }
 300
 301 done:
 302         return nt_status;
 303 }
 304
 305 /**********************************************************************
 306  *********************************************************************/
 307
 308 static NTSTATUS nss_hash_map_to_alias(TALLOC_CTX *mem_ctx,
 309                                         struct nss_domain_entry *e,
 310                                         const char *name,
 311                                         char **alias)
 312 {
 313         NTSTATUS nt_status = NT_STATUS_UNSUCCESSFUL;
 314         const char *value;
 315
 316         value = talloc_asprintf(mem_ctx, "%s\\%s", e->domain, name);
 317         BAIL_ON_PTR_NT_ERROR(value, nt_status);
 318
 319         nt_status = mapfile_lookup_key(mem_ctx, value, alias);
 320         BAIL_ON_NTSTATUS_ERROR(nt_status);
 321
 322 done:
 323         return nt_status;
 324 }
 325
 326 /**********************************************************************
 327  *********************************************************************/
 328
 329 static NTSTATUS nss_hash_map_from_alias(TALLOC_CTX *mem_ctx,
 330                                           struct nss_domain_entry *e,
 331                                           const char *alias,
 332                                           char **name)
 333 {
 334         return mapfile_lookup_value(mem_ctx, alias, name);
 335 }
 336
 337 /**********************************************************************
 338  *********************************************************************/
 339
 340 static NTSTATUS nss_hash_close(void)
 341 {
 342         return NT_STATUS_OK;
 343 }
 344
 345 /*********************************************************************
 346  Dispatch Tables for IDMap and NssInfo Methods
 347 ********************************************************************/
 348
 349 static struct idmap_methods hash_idmap_methods = {
 350         .init            = be_init,
 351         .unixids_to_sids = unixids_to_sids,
 352         .sids_to_unixids = sids_to_unixids,
 353 };
 354
 355 static struct nss_info_methods hash_nss_methods = {
 356         .init           = nss_hash_init,
 357         .get_nss_info   = nss_hash_get_info,
 358         .map_to_alias   = nss_hash_map_to_alias,
 359         .map_from_alias = nss_hash_map_from_alias,
 360         .close_fn       = nss_hash_close
 361 };
 362
 363 /**********************************************************************
 364  Register with the idmap and idmap_nss subsystems. We have to protect
 365  against the idmap and nss_info interfaces being in a half-registered
 366  state.
 367  **********************************************************************/
 368
 369 NTSTATUS samba_init_module(void)
 370 {
 371         static NTSTATUS idmap_status = NT_STATUS_UNSUCCESSFUL;
 372         static NTSTATUS nss_status = NT_STATUS_UNSUCCESSFUL;
 373
 374         if ( !NT_STATUS_IS_OK(idmap_status) ) {
 375                 idmap_status =  smb_register_idmap(SMB_IDMAP_INTERFACE_VERSION,
 376                                                    "hash", &hash_idmap_methods);
 377
 378                 if ( !NT_STATUS_IS_OK(idmap_status) ) {
 379                         DEBUG(0,("Failed to register hash idmap plugin.\n"));
 380                         return idmap_status;
 381                 }
 382         }
 383
 384         if ( !NT_STATUS_IS_OK(nss_status) ) {
 385                 nss_status = smb_register_idmap_nss(SMB_NSS_INFO_INTERFACE_VERSION,
 386                                                     "hash", &hash_nss_methods);
 387                 if ( !NT_STATUS_IS_OK(nss_status) ) {
 388                         DEBUG(0,("Failed to register hash idmap nss plugin.\n"));
 389                         return nss_status;
 390                 }
 391         }
 392
 393         return NT_STATUS_OK;
 394 }