source3/sam/idmap.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    ID Mapping
   4    Copyright (C) Tim Potter 2000
   5    Copyright (C) Jim McDonough <jmcd@us.ibm.com>        2003
   6    Copyright (C) Simo Sorce 2003
   7    Copyright (C) Jeremy Allison 2003.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 2 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program; if not, write to the Free Software
  21    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.*/
  22
  23 #include "includes.h"
  24
  25 #undef DBGC_CLASS
  26 #define DBGC_CLASS DBGC_IDMAP
  27
  28 struct idmap_function_entry {
  29         const char *name;
  30         struct idmap_methods *methods;
  31         struct idmap_function_entry *prev,*next;
  32 };
  33
  34 static struct idmap_function_entry *backends = NULL;
  35
  36 static struct idmap_methods *cache_map;
  37 static struct idmap_methods *remote_map;
  38
  39 static BOOL proxyonly = False;
  40
  41 /**********************************************************************
  42  Get idmap methods. Don't allow tdb to be a remote method.
  43 **********************************************************************/
  44
  45 static struct idmap_methods *get_methods(const char *name, BOOL cache_method)
  46 {
  47         struct idmap_function_entry *entry = backends;
  48
  49         for(entry = backends; entry; entry = entry->next) {
  50                 if (!cache_method && strequal(entry->name, "tdb"))
  51                         continue; /* tdb is only cache method. */
  52                 if (strequal(entry->name, name))
  53                         return entry->methods;
  54         }
  55
  56         return NULL;
  57 }
  58
  59 /**********************************************************************
  60  Allow a module to register itself as a method.
  61 **********************************************************************/
  62
  63 NTSTATUS smb_register_idmap(int version, const char *name, struct idmap_methods *methods)
  64 {
  65         struct idmap_function_entry *entry;
  66
  67         if ((version != SMB_IDMAP_INTERFACE_VERSION)) {
  68                 DEBUG(0, ("smb_register_idmap: Failed to register idmap module.\n"
  69                           "The module was compiled against SMB_IDMAP_INTERFACE_VERSION %d,\n"
  70                           "current SMB_IDMAP_INTERFACE_VERSION is %d.\n"
  71                           "Please recompile against the current version of samba!\n",
  72                           version, SMB_IDMAP_INTERFACE_VERSION));
  73                 return NT_STATUS_OBJECT_TYPE_MISMATCH;
  74         }
  75
  76         if (!name || !name[0] || !methods) {
  77                 DEBUG(0,("smb_register_idmap: called with NULL pointer or empty name!\n"));
  78                 return NT_STATUS_INVALID_PARAMETER;
  79         }
  80
  81         if (get_methods(name, False)) {
  82                 DEBUG(0,("smb_register_idmap: idmap module %s already registered!\n", name));
  83                 return NT_STATUS_OBJECT_NAME_COLLISION;
  84         }
  85
  86         entry = SMB_XMALLOC_P(struct idmap_function_entry);
  87         entry->name = smb_xstrdup(name);
  88         entry->methods = methods;
  89
  90         DLIST_ADD(backends, entry);
  91         DEBUG(5, ("smb_register_idmap: Successfully added idmap backend '%s'\n", name));
  92         return NT_STATUS_OK;
  93 }
  94
  95 /**********************************************************************
  96  Initialise idmap cache and a remote backend (if configured).
  97 **********************************************************************/
  98
  99 BOOL idmap_init(const char **remote_backend)
 100 {
 101         if (!backends)
 102                 static_init_idmap;
 103
 104         if (!cache_map) {
 105                 cache_map = get_methods("tdb", True);
 106
 107                 if (!cache_map) {
 108                         DEBUG(0, ("idmap_init: could not find tdb cache backend!\n"));
 109                         return False;
 110                 }
 111
 112                 if (!NT_STATUS_IS_OK(cache_map->init( NULL ))) {
 113                         DEBUG(0, ("idmap_init: could not initialise tdb cache backend!\n"));
 114                         return False;
 115                 }
 116         }
 117
 118         if ((remote_map == NULL) && (remote_backend != NULL) &&
 119             (*remote_backend != NULL) && (**remote_backend != '\0'))  {
 120                 char *rem_backend = smb_xstrdup(*remote_backend);
 121                 fstring params = "";
 122                 char *pparams;
 123
 124                 /* get any mode parameters passed in */
 125
 126                 if ( (pparams = strchr( rem_backend, ':' )) != NULL ) {
 127                         *pparams = '\0';
 128                         pparams++;
 129                         fstrcpy( params, pparams );
 130                 }
 131
 132                 DEBUG(3, ("idmap_init: using '%s' as remote backend\n", rem_backend));
 133
 134                 if((remote_map = get_methods(rem_backend, False)) ||
 135                     (NT_STATUS_IS_OK(smb_probe_module("idmap", rem_backend)) &&
 136                     (remote_map = get_methods(rem_backend, False)))) {
 137                         if (!NT_STATUS_IS_OK(remote_map->init(params))) {
 138                                 DEBUG(0, ("idmap_init: failed to initialize remote backend!\n"));
 139                                 return False;
 140                         }
 141                 } else {
 142                         DEBUG(0, ("idmap_init: could not load remote backend '%s'\n", rem_backend));
 143                         SAFE_FREE(rem_backend);
 144                         return False;
 145                 }
 146                 SAFE_FREE(rem_backend);
 147         }
 148
 149         return True;
 150 }
 151
 152 /**************************************************************************
 153  Don't do id mapping. This is used to make winbind a netlogon proxy only.
 154 **************************************************************************/
 155
 156 void idmap_set_proxyonly(void)
 157 {
 158         proxyonly = True;
 159 }
 160
 161 BOOL idmap_proxyonly(void)
 162 {
 163         return proxyonly;
 164 }
 165
 166 /**************************************************************************
 167  This is a rare operation, designed to allow an explicit mapping to be
 168  set up for a sid to a POSIX id.
 169 **************************************************************************/
 170
 171 NTSTATUS idmap_set_mapping(const DOM_SID *sid, unid_t id, int id_type)
 172 {
 173         struct idmap_methods *map = remote_map;
 174         DOM_SID tmp_sid;
 175
 176         if (proxyonly)
 177                 return NT_STATUS_UNSUCCESSFUL;
 178
 179         DEBUG(10, ("idmap_set_mapping: Set %s to %s %lu\n",
 180                    sid_string_static(sid),
 181                    ((id_type & ID_TYPEMASK) == ID_USERID) ? "UID" : "GID",
 182                    ((id_type & ID_TYPEMASK) == ID_USERID) ? (unsigned long)id.uid :
 183                    (unsigned long)id.gid));
 184
 185         if ( (NT_STATUS_IS_OK(cache_map->
 186                               get_sid_from_id(&tmp_sid, id,
 187                                               id_type | ID_QUERY_ONLY))) &&
 188              sid_equal(sid, &tmp_sid) ) {
 189                 /* Nothing to do, we already have that mapping */
 190                 DEBUG(10, ("idmap_set_mapping: Mapping already there\n"));
 191                 return NT_STATUS_OK;
 192         }
 193
 194         if (map == NULL) {
 195                 /* Ok, we don't have a authoritative remote
 196                         mapping. So update our local cache only. */
 197                 map = cache_map;
 198         }
 199
 200         return map->set_mapping(sid, id, id_type);
 201 }
 202
 203 /**************************************************************************
 204  Get ID from SID. This can create a mapping for a SID to a POSIX id.
 205 **************************************************************************/
 206
 207 NTSTATUS idmap_get_id_from_sid(unid_t *id, int *id_type, const DOM_SID *sid)
 208 {
 209         NTSTATUS ret;
 210         int loc_type;
 211         unid_t loc_id;
 212
 213         if (proxyonly)
 214                 return NT_STATUS_UNSUCCESSFUL;
 215
 216         loc_type = *id_type;
 217
 218         if (remote_map) {
 219                 /* We have a central remote idmap so only look in
 220                    cache, don't allocate */
 221                 loc_type |= ID_QUERY_ONLY;
 222         }
 223
 224         ret = cache_map->get_id_from_sid(id, &loc_type, sid);
 225
 226         if (NT_STATUS_IS_OK(ret)) {
 227                 *id_type = loc_type & ID_TYPEMASK;
 228                 return NT_STATUS_OK;
 229         }
 230
 231         if ((remote_map == NULL) || (loc_type & ID_CACHE_ONLY)) {
 232                 return ret;
 233         }
 234
 235         /* Before forking out to the possibly slow remote map, lets see if we
 236          * already have the sid as uid when asking for a gid or vice versa. */
 237
 238         loc_type = *id_type & ID_TYPEMASK;
 239
 240         switch (loc_type) {
 241         case ID_USERID:
 242                 loc_type = ID_GROUPID;
 243                 break;
 244         case ID_GROUPID:
 245                 loc_type = ID_USERID;
 246                 break;
 247         default:
 248                 loc_type = ID_EMPTY;
 249         }
 250
 251         loc_type |= ID_QUERY_ONLY;
 252
 253         ret = cache_map->get_id_from_sid(&loc_id, &loc_type, sid);
 254
 255         if (NT_STATUS_IS_OK(ret)) {
 256                 /* Ok, we have the uid as gid or vice versa. The remote map
 257                  * would not know anything different, so return here. */
 258                 return NT_STATUS_UNSUCCESSFUL;
 259         }
 260
 261         /* Ok, the mapping was not in the cache, give the remote map a
 262            second try. */
 263
 264         ret = remote_map->get_id_from_sid(id, id_type, sid);
 265
 266         if (NT_STATUS_IS_OK(ret)) {
 267                 /* The remote backend gave us a valid mapping, cache it. */
 268                 ret = cache_map->set_mapping(sid, *id, *id_type);
 269         }
 270
 271         return ret;
 272 }
 273
 274 /**************************************************************************
 275  Get SID from ID. This must have been created before.
 276 **************************************************************************/
 277
 278 NTSTATUS idmap_get_sid_from_id(DOM_SID *sid, unid_t id, int id_type)
 279 {
 280         NTSTATUS ret;
 281         int loc_type;
 282
 283         if (proxyonly)
 284                 return NT_STATUS_UNSUCCESSFUL;
 285
 286         loc_type = id_type;
 287         if (remote_map) {
 288                 loc_type = id_type | ID_QUERY_ONLY;
 289         }
 290
 291         ret = cache_map->get_sid_from_id(sid, id, loc_type);
 292
 293         if (NT_STATUS_IS_OK(ret))
 294                 return ret;
 295
 296         if ((remote_map == NULL) || (loc_type & ID_CACHE_ONLY))
 297                 return ret;
 298
 299         /* We have a second chance, ask our authoritative backend */
 300
 301         ret = remote_map->get_sid_from_id(sid, id, id_type);
 302
 303         if (NT_STATUS_IS_OK(ret)) {
 304                 /* The remote backend gave us a valid mapping, cache it. */
 305                 ret = cache_map->set_mapping(sid, id, id_type);
 306         }
 307
 308         return ret;
 309 }
 310
 311 /**************************************************************************
 312  Alloocate a new UNIX uid/gid
 313 **************************************************************************/
 314
 315 NTSTATUS idmap_allocate_id(unid_t *id, int id_type)
 316 {
 317         /* we have to allocate from the authoritative backend */
 318
 319         if (proxyonly)
 320                 return NT_STATUS_UNSUCCESSFUL;
 321
 322         if ( remote_map )
 323                 return remote_map->allocate_id( id, id_type );
 324
 325         return cache_map->allocate_id( id, id_type );
 326 }
 327
 328 /**************************************************************************
 329  Alloocate a new RID
 330 **************************************************************************/
 331
 332 NTSTATUS idmap_allocate_rid(uint32 *rid, int type)
 333 {
 334         /* we have to allocate from the authoritative backend */
 335
 336         if (proxyonly)
 337                 return NT_STATUS_UNSUCCESSFUL;
 338
 339         if ( remote_map )
 340                 return remote_map->allocate_rid( rid, type );
 341
 342         return cache_map->allocate_rid( rid, type );
 343 }
 344
 345 /**************************************************************************
 346  Shutdown maps.
 347 **************************************************************************/
 348
 349 NTSTATUS idmap_close(void)
 350 {
 351         NTSTATUS ret;
 352
 353         if (proxyonly)
 354                 return NT_STATUS_OK;
 355
 356         ret = cache_map->close_fn();
 357         if (!NT_STATUS_IS_OK(ret)) {
 358                 DEBUG(3, ("idmap_close: failed to close local tdb cache!\n"));
 359         }
 360         cache_map = NULL;
 361
 362         if (remote_map) {
 363                 ret = remote_map->close_fn();
 364                 if (!NT_STATUS_IS_OK(ret)) {
 365                         DEBUG(3, ("idmap_close: failed to close remote idmap repository!\n"));
 366                 }
 367                 remote_map = NULL;
 368         }
 369
 370         return ret;
 371 }
 372
 373 /**************************************************************************
 374  Dump backend status.
 375 **************************************************************************/
 376
 377 void idmap_status(void)
 378 {
 379         cache_map->status();
 380         if (remote_map)
 381                 remote_map->status();
 382 }