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 = NULL;
  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,
  50                                  const struct nss_info_methods *methods)
  51 {
  52         struct nss_function_entry *entry;
  53
  54         if ((version != SMB_NSS_INFO_INTERFACE_VERSION)) {
  55                 DEBUG(0, ("smb_register_idmap_nss: Failed to register idmap_nss module.\n"
  56                           "The module was compiled against SMB_NSS_INFO_INTERFACE_VERSION %d,\n"
  57                           "current SMB_NSS_INFO_INTERFACE_VERSION is %d.\n"
  58                           "Please recompile against the current version of samba!\n",
  59                           version, SMB_NSS_INFO_INTERFACE_VERSION));
  60                 return NT_STATUS_OBJECT_TYPE_MISMATCH;
  61         }
  62
  63         if (!name || !name[0] || !methods) {
  64                 DEBUG(0,("smb_register_idmap_nss: called with NULL pointer or empty name!\n"));
  65                 return NT_STATUS_INVALID_PARAMETER;
  66         }
  67
  68         if ( nss_get_backend(name) ) {
  69                 DEBUG(5,("smb_register_idmap_nss: idmap module %s "
  70                          "already registered!\n", name));
  71                 return NT_STATUS_OBJECT_NAME_COLLISION;
  72         }
  73
  74         entry = SMB_XMALLOC_P(struct nss_function_entry);
  75         entry->name = smb_xstrdup(name);
  76         entry->methods = methods;
  77
  78         DLIST_ADD(backends, entry);
  79         DEBUG(5, ("smb_register_idmap_nss: Successfully added idmap "
  80                   "nss backend '%s'\n", name));
  81
  82         return NT_STATUS_OK;
  83 }
  84
  85 /********************************************************************
  86  *******************************************************************/
  87
  88 static bool parse_nss_parm(TALLOC_CTX *mem_ctx,
  89                            const char *config,
  90                            char **backend,
  91                            char **domain)
  92 {
  93         char *p;
  94
  95         *backend = *domain = NULL;
  96
  97         if ( !config )
  98                 return False;
  99
 100         p = strchr( config, ':' );
 101
 102         /* if no : then the string must be the backend name only */
 103
 104         if ( !p ) {
 105                 *backend = talloc_strdup(mem_ctx, config);
 106                 return (*backend != NULL);
 107         }
 108
 109         /* split the string and return the two parts */
 110
 111         if ( strlen(p+1) > 0 ) {
 112                 *domain = talloc_strdup(mem_ctx, p + 1);
 113         }
 114
 115         *backend = talloc_strndup(mem_ctx, config, PTR_DIFF(p, config));
 116         return (*backend != NULL);
 117 }
 118
 119 static NTSTATUS nss_domain_list_add_domain(const char *domain,
 120                                            struct nss_function_entry *nss_backend)
 121 {
 122         struct nss_domain_entry *nss_domain;
 123
 124         nss_domain = talloc_zero(nss_domain_list, struct nss_domain_entry);
 125         if (!nss_domain) {
 126                 DEBUG(0, ("nss_domain_list_add_domain: talloc() failure!\n"));
 127                 return NT_STATUS_NO_MEMORY;
 128         }
 129
 130         nss_domain->backend = nss_backend;
 131         if (domain) {
 132                 nss_domain->domain  = talloc_strdup(nss_domain, domain);
 133                 if (!nss_domain->domain) {
 134                         DEBUG(0, ("nss_domain_list_add_domain: talloc() "
 135                                   "failure!\n"));
 136                         TALLOC_FREE(nss_domain);
 137                         return NT_STATUS_NO_MEMORY;
 138                 }
 139         }
 140
 141         nss_domain->init_status = nss_domain->backend->methods->init(nss_domain);
 142         if (!NT_STATUS_IS_OK(nss_domain->init_status))  {
 143                 DEBUG(0, ("nss_init: Failed to init backend '%s' for domain "
 144                           "'%s'!\n", nss_backend->name, nss_domain->domain));
 145         }
 146
 147         DLIST_ADD(nss_domain_list, nss_domain);
 148
 149         DEBUG(10, ("Added domain '%s' with backend '%s' to nss_domain_list.\n",
 150                    domain, nss_backend->name));
 151
 152         return NT_STATUS_OK;
 153 }
 154
 155 /********************************************************************
 156  Each nss backend must not store global state, but rather be able
 157  to initialize the state on a per domain basis.
 158  *******************************************************************/
 159
 160 static NTSTATUS nss_init(const char **nss_list)
 161 {
 162         NTSTATUS status;
 163         static bool nss_initialized = false;
 164         int i;
 165         char *backend = NULL, *domain = NULL;
 166         struct nss_function_entry *nss_backend;
 167         TALLOC_CTX *frame;
 168
 169         /* check for previous successful initializations */
 170
 171         if (nss_initialized) {
 172                 return NT_STATUS_OK;
 173         }
 174
 175         frame = talloc_stackframe();
 176
 177         /* The "template" backend should always be registered as it
 178            is a static module */
 179
 180         nss_backend = nss_get_backend("template");
 181         if (nss_backend == NULL) {
 182                 static_init_nss_info(NULL);
 183         }
 184
 185         /* Create the list of nss_domains (loading any shared plugins
 186            as necessary) */
 187
 188         for ( i=0; nss_list && nss_list[i]; i++ ) {
 189                 bool ok;
 190
 191                 ok = parse_nss_parm(frame, nss_list[i], &backend, &domain);
 192                 if (!ok) {
 193                         DEBUG(0,("nss_init: failed to parse \"%s\"!\n",
 194                                  nss_list[i]));
 195                         continue;
 196                 }
 197
 198                 DEBUG(10, ("parsed backend = '%s', domain = '%s'\n",
 199                            backend, domain));
 200
 201                 /* validate the backend */
 202
 203                 nss_backend = nss_get_backend(backend);
 204                 if (nss_backend == NULL) {
 205                         /*
 206                          * This is a freaking hack. We don't have proper
 207                          * modules for nss_info backends. Right now we have
 208                          * our standard nss_info backends in the ad backend.
 209                          */
 210                         status = smb_probe_module("idmap", "ad");
 211                         if ( !NT_STATUS_IS_OK(status) ) {
 212                                 continue;
 213                         }
 214                 }
 215
 216                 nss_backend = nss_get_backend(backend);
 217                 if (nss_backend == NULL) {
 218                         /* attempt to register the backend */
 219                         status = smb_probe_module( "nss_info", backend );
 220                         if ( !NT_STATUS_IS_OK(status) ) {
 221                                 continue;
 222                         }
 223                 }
 224
 225                 /* try again */
 226                 nss_backend = nss_get_backend(backend);
 227                 if (nss_backend == NULL) {
 228                         DEBUG(0, ("nss_init: unregistered backend %s!. "
 229                                   "Skipping\n", backend));
 230                         continue;
 231                 }
 232
 233                 /*
 234                  * The first config item of the list without an explicit domain
 235                  * is treated as the default nss info backend.
 236                  */
 237                 if ((domain == NULL) && (default_backend == NULL)) {
 238                         DEBUG(10, ("nss_init: using '%s' as default backend.\n",
 239                                    backend));
 240                         default_backend = nss_backend;
 241                 }
 242
 243                 status = nss_domain_list_add_domain(domain, nss_backend);
 244                 if (!NT_STATUS_IS_OK(status)) {
 245                         return status;
 246                 }
 247
 248                 /* cleanup */
 249
 250                 TALLOC_FREE(domain);
 251                 TALLOC_FREE(backend);
 252         }
 253
 254
 255         if ( !nss_domain_list ) {
 256                 DEBUG(3,("nss_init: no nss backends configured.  "
 257                          "Defaulting to \"template\".\n"));
 258
 259
 260                 /* we should default to use template here */
 261         }
 262
 263         nss_initialized = true;
 264
 265         TALLOC_FREE(frame);
 266         return NT_STATUS_OK;
 267 }
 268
 269 /********************************************************************
 270  *******************************************************************/
 271
 272 static struct nss_domain_entry *find_nss_domain( const char *domain )
 273 {
 274         NTSTATUS status;
 275         struct nss_domain_entry *p;
 276
 277         status = nss_init( lp_winbind_nss_info() );
 278         if ( !NT_STATUS_IS_OK(status) ) {
 279                 DEBUG(4,("find_nss_domain: Failed to init nss_info API "
 280                          "(%s)!\n", nt_errstr(status)));
 281                 return NULL;
 282         }
 283
 284         for ( p=nss_domain_list; p; p=p->next ) {
 285                 if ( strequal( p->domain, domain ) )
 286                         break;
 287         }
 288
 289         /* If we didn't find a match, then use the default nss backend */
 290
 291         if ( !p ) {
 292                 if (!default_backend) {
 293                         return NULL;
 294                 }
 295
 296                 status = nss_domain_list_add_domain(domain, default_backend);
 297                 if (!NT_STATUS_IS_OK(status)) {
 298                         return NULL;
 299                 }
 300
 301                 /*
 302                  * HACK ALERT:
 303                  * Here, we use the fact that the new domain was added at
 304                  * the beginning of the list...
 305                  */
 306                 p = nss_domain_list;
 307         }
 308
 309         if ( !NT_STATUS_IS_OK( p->init_status ) ) {
 310                p->init_status = p->backend->methods->init( p );
 311         }
 312
 313         return p;
 314 }
 315
 316 /********************************************************************
 317  *******************************************************************/
 318
 319  NTSTATUS nss_map_to_alias( TALLOC_CTX *mem_ctx, const char *domain,
 320                             const char *name, char **alias )
 321 {
 322         struct nss_domain_entry *p;
 323         const struct nss_info_methods *m;
 324
 325         if ( (p = find_nss_domain( domain )) == NULL ) {
 326                 DEBUG(4,("nss_map_to_alias: Failed to find nss domain pointer for %s\n",
 327                          domain ));
 328                 return NT_STATUS_NOT_FOUND;
 329         }
 330
 331         m = p->backend->methods;
 332
 333         return m->map_to_alias(mem_ctx, p, name, alias);
 334 }
 335
 336
 337 /********************************************************************
 338  *******************************************************************/
 339
 340  NTSTATUS nss_map_from_alias( TALLOC_CTX *mem_ctx, const char *domain,
 341                               const char *alias, char **name )
 342 {
 343         struct nss_domain_entry *p;
 344         const struct nss_info_methods *m;
 345
 346         if ( (p = find_nss_domain( domain )) == NULL ) {
 347                 DEBUG(4,("nss_map_from_alias: Failed to find nss domain pointer for %s\n",
 348                          domain ));
 349                 return NT_STATUS_NOT_FOUND;
 350         }
 351
 352         m = p->backend->methods;
 353
 354         return m->map_from_alias( mem_ctx, p, alias, name );
 355 }
 356
 357 /********************************************************************
 358  *******************************************************************/
 359
 360  NTSTATUS nss_close( const char *parameters )
 361 {
 362         struct nss_domain_entry *p = nss_domain_list;
 363         struct nss_domain_entry *q;
 364
 365         while ( p && p->backend && p->backend->methods ) {
 366                 /* close the backend */
 367                 p->backend->methods->close_fn();
 368
 369                 /* free the memory */
 370                 q = p;
 371                 p = p->next;
 372                 TALLOC_FREE( q );
 373         }
 374
 375         return NT_STATUS_OK;
 376 }
 377