source3/winbindd/nss_info.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Idmap NSS headers
   4
   5    Copyright (C) Gerald Carter             2006
   6    Copyright (C) Michael Adam 2008
   7
   8    This library is free software; you can redistribute it and/or
   9    modify it under the terms of the GNU Lesser General Public
  10    License as published by the Free Software Foundation; either
  11    version 3 of the License, or (at your option) any later version.
  12
  13    This library is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16    Library General Public License for more details.
  17
  18    You should have received a copy of the GNU Lesser General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  20 */
  21
  22 #include "includes.h"
  23 #include "nss_info.h"
  24
  25 static struct nss_function_entry *backends = NULL;
  26 static struct nss_function_entry *default_backend = NULL;
  27 static struct nss_domain_entry *nss_domain_list = NULL;
  28
  29 /**********************************************************************
  30  Get idmap nss methods.
  31 **********************************************************************/
  32
  33 static struct nss_function_entry *nss_get_backend(const char *name )
  34 {
  35         struct nss_function_entry *entry = backends;
  36
  37         for(entry = backends; entry; entry = entry->next) {
  38                 if ( strequal(entry->name, name) )
  39                         return entry;
  40         }
  41
  42         return NULL;
  43 }
  44
  45 /*********************************************************************
  46  Allow a module to register itself as a backend.
  47 **********************************************************************/
  48
  49  NTSTATUS smb_register_idmap_nss(int version, const char *name, struct nss_info_methods *methods)
  50 {
  51         struct nss_function_entry *entry;
  52
  53         if ((version != SMB_NSS_INFO_INTERFACE_VERSION)) {
  54                 DEBUG(0, ("smb_register_idmap_nss: Failed to register idmap_nss module.\n"
  55                           "The module was compiled against SMB_NSS_INFO_INTERFACE_VERSION %d,\n"
  56                           "current SMB_NSS_INFO_INTERFACE_VERSION is %d.\n"
  57                           "Please recompile against the current version of samba!\n",
  58                           version, SMB_NSS_INFO_INTERFACE_VERSION));
  59                 return NT_STATUS_OBJECT_TYPE_MISMATCH;
  60         }
  61
  62         if (!name || !name[0] || !methods) {
  63                 DEBUG(0,("smb_register_idmap_nss: called with NULL pointer or empty name!\n"));
  64                 return NT_STATUS_INVALID_PARAMETER;
  65         }
  66
  67         if ( nss_get_backend(name) ) {
  68                 DEBUG(5,("smb_register_idmap_nss: idmap module %s "
  69                          "already registered!\n", name));
  70                 return NT_STATUS_OBJECT_NAME_COLLISION;
  71         }
  72
  73         entry = SMB_XMALLOC_P(struct nss_function_entry);
  74         entry->name = smb_xstrdup(name);
  75         entry->methods = methods;
  76
  77         DLIST_ADD(backends, entry);
  78         DEBUG(5, ("smb_register_idmap_nss: Successfully added idmap "
  79                   "nss backend '%s'\n", name));
  80
  81         return NT_STATUS_OK;
  82 }
  83
  84 /********************************************************************
  85  *******************************************************************/
  86
  87 static bool parse_nss_parm(TALLOC_CTX *mem_ctx,
  88                            const char *config,
  89                            char **backend,
  90                            char **domain)
  91 {
  92         char *p;
  93
  94         *backend = *domain = NULL;
  95
  96         if ( !config )
  97                 return False;
  98
  99         p = strchr( config, ':' );
 100
 101         /* if no : then the string must be the backend name only */
 102
 103         if ( !p ) {
 104                 *backend = talloc_strdup(mem_ctx, config);
 105                 return (*backend != NULL);
 106         }
 107
 108         /* split the string and return the two parts */
 109
 110         if ( strlen(p+1) > 0 ) {
 111                 *domain = talloc_strdup(mem_ctx, p + 1);
 112         }
 113
 114         *backend = talloc_strndup(mem_ctx, config, PTR_DIFF(p, config));
 115         return (*backend != NULL);
 116 }
 117
 118 static NTSTATUS nss_domain_list_add_domain(const char *domain,
 119                                            struct nss_function_entry *nss_backend)
 120 {
 121         struct nss_domain_entry *nss_domain;
 122
 123         nss_domain = talloc_zero(nss_domain_list, struct nss_domain_entry);
 124         if (!nss_domain) {
 125                 DEBUG(0, ("nss_domain_list_add_domain: talloc() failure!\n"));
 126                 return NT_STATUS_NO_MEMORY;
 127         }
 128
 129         nss_domain->backend = nss_backend;
 130         if (domain) {
 131                 nss_domain->domain  = talloc_strdup(nss_domain, domain);
 132                 if (!nss_domain->domain) {
 133                         DEBUG(0, ("nss_domain_list_add_domain: talloc() "
 134                                   "failure!\n"));
 135                         TALLOC_FREE(nss_domain);
 136                         return NT_STATUS_NO_MEMORY;
 137                 }
 138         }
 139
 140         nss_domain->init_status = nss_domain->backend->methods->init(nss_domain);
 141         if (!NT_STATUS_IS_OK(nss_domain->init_status))  {
 142                 DEBUG(0, ("nss_init: Failed to init backend '%s' for domain "
 143                           "'%s'!\n", nss_backend->name, nss_domain->domain));
 144         }
 145
 146         DLIST_ADD(nss_domain_list, nss_domain);
 147
 148         DEBUG(10, ("Added domain '%s' with backend '%s' to nss_domain_list.\n",
 149                    domain, nss_backend->name));
 150
 151         return NT_STATUS_OK;
 152 }
 153
 154 /********************************************************************
 155  Each nss backend must not store global state, but rather be able
 156  to initialize the state on a per domain basis.
 157  *******************************************************************/
 158
 159 static NTSTATUS nss_init(const char **nss_list)
 160 {
 161         NTSTATUS status;
 162         static bool nss_initialized = false;
 163         int i;
 164         char *backend = NULL, *domain = NULL;
 165         struct nss_function_entry *nss_backend;
 166         TALLOC_CTX *frame;
 167
 168         /* check for previous successful initializations */
 169
 170         if (nss_initialized) {
 171                 return NT_STATUS_OK;
 172         }
 173
 174         frame = talloc_stackframe();
 175
 176         /* The "template" backend should always be registered as it
 177            is a static module */
 178
 179         nss_backend = nss_get_backend("template");
 180         if (nss_backend == NULL) {
 181                 static_init_nss_info(NULL);
 182         }
 183
 184         /* Create the list of nss_domains (loading any shared plugins
 185            as necessary) */
 186
 187         for ( i=0; nss_list && nss_list[i]; i++ ) {
 188                 bool ok;
 189
 190                 ok = parse_nss_parm(frame, nss_list[i], &backend, &domain);
 191                 if (!ok) {
 192                         DEBUG(0,("nss_init: failed to parse \"%s\"!\n",
 193                                  nss_list[i]));
 194                         continue;
 195                 }
 196
 197                 DEBUG(10, ("parsed backend = '%s', domain = '%s'\n",
 198                            backend, domain));
 199
 200                 /* validate the backend */
 201
 202                 nss_backend = nss_get_backend(backend);
 203                 if (nss_backend == NULL) {
 204                         /*
 205                          * This is a freaking hack. We don't have proper
 206                          * modules for nss_info backends. Right now we have
 207                          * our standard nss_info backends in the ad backend.
 208                          */
 209                         status = smb_probe_module("idmap", "ad");
 210                         if ( !NT_STATUS_IS_OK(status) ) {
 211                                 continue;
 212                         }
 213                 }
 214
 215                 nss_backend = nss_get_backend(backend);
 216                 if (nss_backend == NULL) {
 217                         /* attempt to register the backend */
 218                         status = smb_probe_module( "nss_info", backend );
 219                         if ( !NT_STATUS_IS_OK(status) ) {
 220                                 continue;
 221                         }
 222                 }
 223
 224                 /* try again */
 225                 nss_backend = nss_get_backend(backend);
 226                 if (nss_backend == NULL) {
 227                         DEBUG(0, ("nss_init: unregistered backend %s!. "
 228                                   "Skipping\n", backend));
 229                         continue;
 230                 }
 231
 232                 /*
 233                  * The first config item of the list without an explicit domain
 234                  * is treated as the default nss info backend.
 235                  */
 236                 if ((domain == NULL) && (default_backend == NULL)) {
 237                         DEBUG(10, ("nss_init: using '%s' as default backend.\n",
 238                                    backend));
 239                         default_backend = nss_backend;
 240                 }
 241
 242                 status = nss_domain_list_add_domain(domain, nss_backend);
 243                 if (!NT_STATUS_IS_OK(status)) {
 244                         return status;
 245                 }
 246
 247                 /* cleanup */
 248
 249                 TALLOC_FREE(domain);
 250                 TALLOC_FREE(backend);
 251         }
 252
 253
 254         if ( !nss_domain_list ) {
 255                 DEBUG(3,("nss_init: no nss backends configured.  "
 256                          "Defaulting to \"template\".\n"));
 257
 258
 259                 /* we should default to use template here */
 260         }
 261
 262         nss_initialized = true;
 263
 264         TALLOC_FREE(frame);
 265         return NT_STATUS_OK;
 266 }
 267
 268 /********************************************************************
 269  *******************************************************************/
 270
 271 static struct nss_domain_entry *find_nss_domain( const char *domain )
 272 {
 273         NTSTATUS status;
 274         struct nss_domain_entry *p;
 275
 276         status = nss_init( lp_winbind_nss_info() );
 277         if ( !NT_STATUS_IS_OK(status) ) {
 278                 DEBUG(4,("find_nss_domain: Failed to init nss_info API "
 279                          "(%s)!\n", nt_errstr(status)));
 280                 return NULL;
 281         }
 282
 283         for ( p=nss_domain_list; p; p=p->next ) {
 284                 if ( strequal( p->domain, domain ) )
 285                         break;
 286         }
 287
 288         /* If we didn't find a match, then use the default nss backend */
 289
 290         if ( !p ) {
 291                 if (!default_backend) {
 292                         return NULL;
 293                 }
 294
 295                 status = nss_domain_list_add_domain(domain, default_backend);
 296                 if (!NT_STATUS_IS_OK(status)) {
 297                         return NULL;
 298                 }
 299
 300                 /*
 301                  * HACK ALERT:
 302                  * Here, we use the fact that the new domain was added at
 303                  * the beginning of the list...
 304                  */
 305                 p = nss_domain_list;
 306         }
 307
 308         if ( !NT_STATUS_IS_OK( p->init_status ) ) {
 309                p->init_status = p->backend->methods->init( p );
 310         }
 311
 312         return p;
 313 }
 314
 315 /********************************************************************
 316  *******************************************************************/
 317
 318  NTSTATUS nss_map_to_alias( TALLOC_CTX *mem_ctx, const char *domain,
 319                             const char *name, char **alias )
 320 {
 321         struct nss_domain_entry *p;
 322         struct nss_info_methods *m;
 323
 324         if ( (p = find_nss_domain( domain )) == NULL ) {
 325                 DEBUG(4,("nss_map_to_alias: Failed to find nss domain pointer for %s\n",
 326                          domain ));
 327                 return NT_STATUS_NOT_FOUND;
 328         }
 329
 330         m = p->backend->methods;
 331
 332         return m->map_to_alias(mem_ctx, p, name, alias);
 333 }
 334
 335
 336 /********************************************************************
 337  *******************************************************************/
 338
 339  NTSTATUS nss_map_from_alias( TALLOC_CTX *mem_ctx, const char *domain,
 340                               const char *alias, char **name )
 341 {
 342         struct nss_domain_entry *p;
 343         struct nss_info_methods *m;
 344
 345         if ( (p = find_nss_domain( domain )) == NULL ) {
 346                 DEBUG(4,("nss_map_from_alias: Failed to find nss domain pointer for %s\n",
 347                          domain ));
 348                 return NT_STATUS_NOT_FOUND;
 349         }
 350
 351         m = p->backend->methods;
 352
 353         return m->map_from_alias( mem_ctx, p, alias, name );
 354 }
 355
 356 /********************************************************************
 357  *******************************************************************/
 358
 359  NTSTATUS nss_close( const char *parameters )
 360 {
 361         struct nss_domain_entry *p = nss_domain_list;
 362         struct nss_domain_entry *q;
 363
 364         while ( p && p->backend && p->backend->methods ) {
 365                 /* close the backend */
 366                 p->backend->methods->close_fn();
 367
 368                 /* free the memory */
 369                 q = p;
 370                 p = p->next;
 371                 TALLOC_FREE( q );
 372         }
 373
 374         return NT_STATUS_OK;
 375 }
 376