nss/nsswitch.c

   1 /* Copyright (C) 1996-1999,2001-2007,2009,2010,2011
   2    Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library 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 GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <ctype.h>
  21 #include <dlfcn.h>
  22 #include <errno.h>
  23 #include <netdb.h>
  24 #include <bits/libc-lock.h>
  25 #include <search.h>
  26 #include <stdio.h>
  27 #include <stdio_ext.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30
  31 #include <aliases.h>
  32 #include <grp.h>
  33 #include <netinet/ether.h>
  34 #include <pwd.h>
  35 #include <shadow.h>
  36
  37 #if !defined DO_STATIC_NSS || defined SHARED
  38 # include <gnu/lib-names.h>
  39 #endif
  40
  41 #include "nsswitch.h"
  42 #include "../nscd/nscd_proto.h"
  43 #include <sysdep.h>
  44
  45 /* Prototypes for the local functions.  */
  46 static name_database *nss_parse_file (const char *fname) internal_function;
  47 static name_database_entry *nss_getline (char *line) internal_function;
  48 static service_user *nss_parse_service_list (const char *line)
  49      internal_function;
  50 static service_library *nss_new_service (name_database *database,
  51                                          const char *name) internal_function;
  52
  53
  54 /* Declare external database variables.  */
  55 #define DEFINE_DATABASE(name)                                                 \
  56   extern service_user *__nss_##name##_database attribute_hidden;              \
  57   weak_extern (__nss_##name##_database)
  58 #include "databases.def"
  59 #undef DEFINE_DATABASE
  60
  61 /* Structure to map database name to variable.  */
  62 static const struct
  63 {
  64   const char name[10];
  65   service_user **dbp;
  66 } databases[] =
  67 {
  68 #define DEFINE_DATABASE(name)                                                 \
  69   { #name, &__nss_##name##_database },
  70 #include "databases.def"
  71 #undef DEFINE_DATABASE
  72 };
  73 #define ndatabases (sizeof (databases) / sizeof (databases[0]))
  74
  75 /* Flags whether custom rules for database is set.  */
  76 bool __nss_database_custom[NSS_DBSIDX_max];
  77
  78
  79 __libc_lock_define_initialized (static, lock)
  80
  81 #if !defined DO_STATIC_NSS || defined SHARED
  82 /* String with revision number of the shared object files.  */
  83 static const char *const __nss_shlib_revision = LIBNSS_FILES_SO + 15;
  84 #endif
  85
  86 /* The root of the whole data base.  */
  87 static name_database *service_table;
  88
  89
  90 /* Nonzero if this is the nscd process.  */
  91 static bool is_nscd;
  92 /* The callback passed to the init functions when nscd is used.  */
  93 static void (*nscd_init_cb) (size_t, struct traced_file *);
  94
  95
  96 /* -1 == database not found
  97     0 == database entry pointer stored */
  98 int
  99 __nss_database_lookup (const char *database, const char *alternate_name,
 100                        const char *defconfig, service_user **ni)
 101 {
 102   /* Prevent multiple threads to change the service table.  */
 103   __libc_lock_lock (lock);
 104
 105   /* Reconsider database variable in case some other thread called
 106      `__nss_configure_lookup' while we waited for the lock.  */
 107   if (*ni != NULL)
 108     {
 109       __libc_lock_unlock (lock);
 110       return 0;
 111     }
 112
 113   /* Are we initialized yet?  */
 114   if (service_table == NULL)
 115     /* Read config file.  */
 116     service_table = nss_parse_file (_PATH_NSSWITCH_CONF);
 117
 118   /* Test whether configuration data is available.  */
 119   if (service_table != NULL)
 120     {
 121       /* Return first `service_user' entry for DATABASE.  */
 122       name_database_entry *entry;
 123
 124       /* XXX Could use some faster mechanism here.  But each database is
 125          only requested once and so this might not be critical.  */
 126       for (entry = service_table->entry; entry != NULL; entry = entry->next)
 127         if (strcmp (database, entry->name) == 0)
 128           *ni = entry->service;
 129
 130       if (*ni == NULL && alternate_name != NULL)
 131         /* We haven't found an entry so far.  Try to find it with the
 132            alternative name.  */
 133         for (entry = service_table->entry; entry != NULL; entry = entry->next)
 134           if (strcmp (alternate_name, entry->name) == 0)
 135             *ni = entry->service;
 136     }
 137
 138   /* No configuration data is available, either because nsswitch.conf
 139      doesn't exist or because it doesn't have a line for this database.
 140
 141      DEFCONFIG specifies the default service list for this database,
 142      or null to use the most common default.  */
 143   if (*ni == NULL)
 144     *ni = nss_parse_service_list (defconfig
 145                                   ?: "nis [NOTFOUND=return] files");
 146
 147   __libc_lock_unlock (lock);
 148
 149   return *ni != NULL ? 0 : -1;
 150 }
 151 libc_hidden_def (__nss_database_lookup)
 152
 153
 154 /* -1 == not found
 155     0 == function found
 156     1 == finished */
 157 int
 158 __nss_lookup (service_user **ni, const char *fct_name, const char *fct2_name,
 159               void **fctp)
 160 {
 161   *fctp = __nss_lookup_function (*ni, fct_name);
 162   if (*fctp == NULL && fct2_name != NULL)
 163     *fctp = __nss_lookup_function (*ni, fct2_name);
 164
 165   while (*fctp == NULL
 166          && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_CONTINUE
 167          && (*ni)->next != NULL)
 168     {
 169       *ni = (*ni)->next;
 170
 171       *fctp = __nss_lookup_function (*ni, fct_name);
 172       if (*fctp == NULL && fct2_name != NULL)
 173         *fctp = __nss_lookup_function (*ni, fct2_name);
 174     }
 175
 176   return *fctp != NULL ? 0 : (*ni)->next == NULL ? 1 : -1;
 177 }
 178 libc_hidden_def (__nss_lookup)
 179
 180
 181 /* -1 == not found
 182     0 == adjusted for next function
 183     1 == finished */
 184 int
 185 __nss_next2 (service_user **ni, const char *fct_name, const char *fct2_name,
 186              void **fctp, int status, int all_values)
 187 {
 188   if (all_values)
 189     {
 190       if (nss_next_action (*ni, NSS_STATUS_TRYAGAIN) == NSS_ACTION_RETURN
 191           && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_RETURN
 192           && nss_next_action (*ni, NSS_STATUS_NOTFOUND) == NSS_ACTION_RETURN
 193           && nss_next_action (*ni, NSS_STATUS_SUCCESS) == NSS_ACTION_RETURN)
 194         return 1;
 195     }
 196   else
 197     {
 198       /* This is really only for debugging.  */
 199       if (__builtin_expect (NSS_STATUS_TRYAGAIN > status
 200                             || status > NSS_STATUS_RETURN, 0))
 201          __libc_fatal ("illegal status in __nss_next");
 202
 203        if (nss_next_action (*ni, status) == NSS_ACTION_RETURN)
 204          return 1;
 205     }
 206
 207   if ((*ni)->next == NULL)
 208     return -1;
 209
 210   do
 211     {
 212       *ni = (*ni)->next;
 213
 214       *fctp = __nss_lookup_function (*ni, fct_name);
 215       if (*fctp == NULL && fct2_name != NULL)
 216         *fctp = __nss_lookup_function (*ni, fct2_name);
 217     }
 218   while (*fctp == NULL
 219          && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_CONTINUE
 220          && (*ni)->next != NULL);
 221
 222   return *fctp != NULL ? 0 : -1;
 223 }
 224 libc_hidden_def (__nss_next2)
 225
 226
 227 int
 228 attribute_compat_text_section
 229 __nss_next (service_user **ni, const char *fct_name, void **fctp, int status,
 230             int all_values)
 231 {
 232   return __nss_next2 (ni, fct_name, NULL, fctp, status, all_values);
 233 }
 234
 235
 236 int
 237 __nss_configure_lookup (const char *dbname, const char *service_line)
 238 {
 239   service_user *new_db;
 240   size_t cnt;
 241
 242   for (cnt = 0; cnt < ndatabases; ++cnt)
 243     {
 244       int cmp = strcmp (dbname, databases[cnt].name);
 245       if (cmp == 0)
 246         break;
 247       if (cmp < 0)
 248         {
 249           __set_errno (EINVAL);
 250           return -1;
 251         }
 252     }
 253
 254   if (cnt == ndatabases)
 255     {
 256       __set_errno (EINVAL);
 257       return -1;
 258     }
 259
 260   /* Test whether it is really used.  */
 261   if (databases[cnt].dbp == NULL)
 262     /* Nothing to do, but we could do.  */
 263     return 0;
 264
 265   /* Try to generate new data.  */
 266   new_db = nss_parse_service_list (service_line);
 267   if (new_db == NULL)
 268     {
 269       /* Illegal service specification.  */
 270       __set_errno (EINVAL);
 271       return -1;
 272     }
 273
 274   /* Prevent multiple threads to change the service table.  */
 275   __libc_lock_lock (lock);
 276
 277   /* Install new rules.  */
 278   *databases[cnt].dbp = new_db;
 279   __nss_database_custom[cnt] = true;
 280
 281   __libc_lock_unlock (lock);
 282
 283   return 0;
 284 }
 285
 286
 287 /* Comparison function for searching NI->known tree.  */
 288 static int
 289 known_compare (const void *p1, const void *p2)
 290 {
 291   return p1 == p2 ? 0 : strcmp (*(const char *const *) p1,
 292                                 *(const char *const *) p2);
 293 }
 294
 295
 296 #if !defined DO_STATIC_NSS || defined SHARED
 297 /* Load library.  */
 298 static int
 299 nss_load_library (service_user *ni)
 300 {
 301   if (ni->library == NULL)
 302     {
 303       /* This service has not yet been used.  Fetch the service
 304          library for it, creating a new one if need be.  If there
 305          is no service table from the file, this static variable
 306          holds the head of the service_library list made from the
 307          default configuration.  */
 308       static name_database default_table;
 309       ni->library = nss_new_service (service_table ?: &default_table,
 310                                      ni->name);
 311       if (ni->library == NULL)
 312         return -1;
 313     }
 314
 315   if (ni->library->lib_handle == NULL)
 316     {
 317       /* Load the shared library.  */
 318       size_t shlen = (7 + strlen (ni->library->name) + 3
 319                       + strlen (__nss_shlib_revision) + 1);
 320       int saved_errno = errno;
 321       char shlib_name[shlen];
 322
 323       /* Construct shared object name.  */
 324       __stpcpy (__stpcpy (__stpcpy (__stpcpy (shlib_name,
 325                                               "libnss_"),
 326                                     ni->library->name),
 327                           ".so"),
 328                 __nss_shlib_revision);
 329
 330       ni->library->lib_handle = __libc_dlopen (shlib_name);
 331       if (ni->library->lib_handle == NULL)
 332         {
 333           /* Failed to load the library.  */
 334           ni->library->lib_handle = (void *) -1l;
 335           __set_errno (saved_errno);
 336         }
 337       else if (is_nscd)
 338         {
 339           /* Call the init function when nscd is used.  */
 340           size_t initlen = (5 + strlen (ni->library->name)
 341                             + strlen ("_init") + 1);
 342           char init_name[initlen];
 343
 344           /* Construct the init function name.  */
 345           __stpcpy (__stpcpy (__stpcpy (init_name,
 346                                         "_nss_"),
 347                               ni->library->name),
 348                     "_init");
 349
 350           /* Find the optional init function.  */
 351           void (*ifct) (void (*) (size_t, struct traced_file *))
 352             = __libc_dlsym (ni->library->lib_handle, init_name);
 353           if (ifct != NULL)
 354             {
 355               void (*cb) (size_t, struct traced_file *) = nscd_init_cb;
 356 # ifdef PTR_DEMANGLE
 357               PTR_DEMANGLE (cb);
 358 # endif
 359               ifct (cb);
 360             }
 361         }
 362     }
 363
 364   return 0;
 365 }
 366 #endif
 367
 368
 369 void *
 370 __nss_lookup_function (service_user *ni, const char *fct_name)
 371 {
 372   void **found, *result;
 373
 374   /* We now modify global data.  Protect it.  */
 375   __libc_lock_lock (lock);
 376
 377   /* Search the tree of functions previously requested.  Data in the
 378      tree are `known_function' structures, whose first member is a
 379      `const char *', the lookup key.  The search returns a pointer to
 380      the tree node structure; the first member of the is a pointer to
 381      our structure (i.e. what will be a `known_function'); since the
 382      first member of that is the lookup key string, &FCT_NAME is close
 383      enough to a pointer to our structure to use as a lookup key that
 384      will be passed to `known_compare' (above).  */
 385
 386   found = __tsearch (&fct_name, &ni->known, &known_compare);
 387   if (found == NULL)
 388     /* This means out-of-memory.  */
 389     result = NULL;
 390   else if (*found != &fct_name)
 391     {
 392       /* The search found an existing structure in the tree.  */
 393       result = ((known_function *) *found)->fct_ptr;
 394       PTR_DEMANGLE (result);
 395     }
 396   else
 397     {
 398       /* This name was not known before.  Now we have a node in the tree
 399          (in the proper sorted position for FCT_NAME) that points to
 400          &FCT_NAME instead of any real `known_function' structure.
 401          Allocate a new structure and fill it in.  */
 402
 403       known_function *known = malloc (sizeof *known);
 404       if (! known)
 405         {
 406         remove_from_tree:
 407           /* Oops.  We can't instantiate this node properly.
 408              Remove it from the tree.  */
 409           __tdelete (&fct_name, &ni->known, &known_compare);
 410           free (known);
 411           result = NULL;
 412         }
 413       else
 414         {
 415           /* Point the tree node at this new structure.  */
 416           *found = known;
 417           known->fct_name = fct_name;
 418
 419 #if !defined DO_STATIC_NSS || defined SHARED
 420           /* Load the appropriate library.  */
 421           if (nss_load_library (ni) != 0)
 422             /* This only happens when out of memory.  */
 423             goto remove_from_tree;
 424
 425           if (ni->library->lib_handle == (void *) -1l)
 426             /* Library not found => function not found.  */
 427             result = NULL;
 428           else
 429             {
 430               /* Get the desired function.  */
 431               size_t namlen = (5 + strlen (ni->library->name) + 1
 432                                + strlen (fct_name) + 1);
 433               char name[namlen];
 434
 435               /* Construct the function name.  */
 436               __stpcpy (__stpcpy (__stpcpy (__stpcpy (name, "_nss_"),
 437                                             ni->library->name),
 438                                   "_"),
 439                         fct_name);
 440
 441               /* Look up the symbol.  */
 442               result = __libc_dlsym (ni->library->lib_handle, name);
 443             }
 444 #else
 445           /* We can't get function address dynamically in static linking. */
 446           {
 447 # define DEFINE_ENT(h,nm)                                                     \
 448             { #h"_get"#nm"ent_r", _nss_##h##_get##nm##ent_r },                \
 449             { #h"_end"#nm"ent", _nss_##h##_end##nm##ent },                    \
 450             { #h"_set"#nm"ent", _nss_##h##_set##nm##ent },
 451 # define DEFINE_GET(h,nm)                                                     \
 452             { #h"_get"#nm"_r", _nss_##h##_get##nm##_r },
 453 # define DEFINE_GETBY(h,nm,ky)                                                \
 454             { #h"_get"#nm"by"#ky"_r", _nss_##h##_get##nm##by##ky##_r },
 455             static struct fct_tbl { const char *fname; void *fp; } *tp, tbl[] =
 456               {
 457 # include "function.def"
 458                 { NULL, NULL }
 459               };
 460             size_t namlen = (5 + strlen (ni->library->name) + 1
 461                              + strlen (fct_name) + 1);
 462             char name[namlen];
 463
 464             /* Construct the function name.  */
 465             __stpcpy (__stpcpy (__stpcpy (name, ni->library->name),
 466                                 "_"),
 467                       fct_name);
 468
 469             result = NULL;
 470             for (tp = &tbl[0]; tp->fname; tp++)
 471               if (strcmp (tp->fname, name) == 0)
 472                 {
 473                   result = tp->fp;
 474                   break;
 475                 }
 476           }
 477 #endif
 478
 479           /* Remember function pointer for later calls.  Even if null, we
 480              record it so a second try needn't search the library again.  */
 481           known->fct_ptr = result;
 482           PTR_MANGLE (known->fct_ptr);
 483         }
 484     }
 485
 486   /* Remove the lock.  */
 487   __libc_lock_unlock (lock);
 488
 489   return result;
 490 }
 491 libc_hidden_def (__nss_lookup_function)
 492
 493
 494 static name_database *
 495 internal_function
 496 nss_parse_file (const char *fname)
 497 {
 498   FILE *fp;
 499   name_database *result;
 500   name_database_entry *last;
 501   char *line;
 502   size_t len;
 503
 504   /* Open the configuration file.  */
 505   fp = fopen (fname, "rce");
 506   if (fp == NULL)
 507     return NULL;
 508
 509   /* No threads use this stream.  */
 510   __fsetlocking (fp, FSETLOCKING_BYCALLER);
 511
 512   result = (name_database *) malloc (sizeof (name_database));
 513   if (result == NULL)
 514     {
 515       fclose (fp);
 516       return NULL;
 517     }
 518
 519   result->entry = NULL;
 520   result->library = NULL;
 521   last = NULL;
 522   line = NULL;
 523   len = 0;
 524   do
 525     {
 526       name_database_entry *this;
 527       ssize_t n;
 528
 529       n = __getline (&line, &len, fp);
 530       if (n < 0)
 531         break;
 532       if (line[n - 1] == '\n')
 533         line[n - 1] = '\0';
 534
 535       /* Because the file format does not know any form of quoting we
 536          can search forward for the next '#' character and if found
 537          make it terminating the line.  */
 538       *__strchrnul (line, '#') = '\0';
 539
 540       /* If the line is blank it is ignored.  */
 541       if (line[0] == '\0')
 542         continue;
 543
 544       /* Each line completely specifies the actions for a database.  */
 545       this = nss_getline (line);
 546       if (this != NULL)
 547         {
 548           if (last != NULL)
 549             last->next = this;
 550           else
 551             result->entry = this;
 552
 553           last = this;
 554         }
 555     }
 556   while (!feof_unlocked (fp));
 557
 558   /* Free the buffer.  */
 559   free (line);
 560   /* Close configuration file.  */
 561   fclose (fp);
 562
 563   return result;
 564 }
 565
 566
 567 /* Read the source names:
 568         `( <source> ( "[" "!"? (<status> "=" <action> )+ "]" )? )*'
 569    */
 570 static service_user *
 571 internal_function
 572 nss_parse_service_list (const char *line)
 573 {
 574   service_user *result = NULL, **nextp = &result;
 575
 576   while (1)
 577     {
 578       service_user *new_service;
 579       const char *name;
 580
 581       while (isspace (line[0]))
 582         ++line;
 583       if (line[0] == '\0')
 584         /* No source specified.  */
 585         return result;
 586
 587       /* Read <source> identifier.  */
 588       name = line;
 589       while (line[0] != '\0' && !isspace (line[0]) && line[0] != '[')
 590         ++line;
 591       if (name == line)
 592         return result;
 593
 594
 595       new_service = (service_user *) malloc (sizeof (service_user)
 596                                              + (line - name + 1));
 597       if (new_service == NULL)
 598         return result;
 599
 600       *((char *) __mempcpy (new_service->name, name, line - name)) = '\0';
 601
 602       /* Set default actions.  */
 603       new_service->actions[2 + NSS_STATUS_TRYAGAIN] = NSS_ACTION_CONTINUE;
 604       new_service->actions[2 + NSS_STATUS_UNAVAIL] = NSS_ACTION_CONTINUE;
 605       new_service->actions[2 + NSS_STATUS_NOTFOUND] = NSS_ACTION_CONTINUE;
 606       new_service->actions[2 + NSS_STATUS_SUCCESS] = NSS_ACTION_RETURN;
 607       new_service->actions[2 + NSS_STATUS_RETURN] = NSS_ACTION_RETURN;
 608       new_service->library = NULL;
 609       new_service->known = NULL;
 610       new_service->next = NULL;
 611
 612       while (isspace (line[0]))
 613         ++line;
 614
 615       if (line[0] == '[')
 616         {
 617           /* Read criterions.  */
 618           do
 619             ++line;
 620           while (line[0] != '\0' && isspace (line[0]));
 621
 622           do
 623             {
 624               int not;
 625               enum nss_status status;
 626               lookup_actions action;
 627
 628               /* Grok ! before name to mean all statii but that one.  */
 629               not = line[0] == '!';
 630               if (not)
 631                 ++line;
 632
 633               /* Read status name.  */
 634               name = line;
 635               while (line[0] != '\0' && !isspace (line[0]) && line[0] != '='
 636                      && line[0] != ']')
 637                 ++line;
 638
 639               /* Compare with known statii.  */
 640               if (line - name == 7)
 641                 {
 642                   if (__strncasecmp (name, "SUCCESS", 7) == 0)
 643                     status = NSS_STATUS_SUCCESS;
 644                   else if (__strncasecmp (name, "UNAVAIL", 7) == 0)
 645                     status = NSS_STATUS_UNAVAIL;
 646                   else
 647                     return result;
 648                 }
 649               else if (line - name == 8)
 650                 {
 651                   if (__strncasecmp (name, "NOTFOUND", 8) == 0)
 652                     status = NSS_STATUS_NOTFOUND;
 653                   else if (__strncasecmp (name, "TRYAGAIN", 8) == 0)
 654                     status = NSS_STATUS_TRYAGAIN;
 655                   else
 656                     return result;
 657                 }
 658               else
 659                 return result;
 660
 661               while (isspace (line[0]))
 662                 ++line;
 663               if (line[0] != '=')
 664                 return result;
 665               do
 666                 ++line;
 667               while (isspace (line[0]));
 668
 669               name = line;
 670               while (line[0] != '\0' && !isspace (line[0]) && line[0] != '='
 671                      && line[0] != ']')
 672                 ++line;
 673
 674               if (line - name == 6 && __strncasecmp (name, "RETURN", 6) == 0)
 675                 action = NSS_ACTION_RETURN;
 676               else if (line - name == 8
 677                        && __strncasecmp (name, "CONTINUE", 8) == 0)
 678                 action = NSS_ACTION_CONTINUE;
 679               else
 680                 return result;
 681
 682               if (not)
 683                 {
 684                   /* Save the current action setting for this status,
 685                      set them all to the given action, and reset this one.  */
 686                   const lookup_actions save = new_service->actions[2 + status];
 687                   new_service->actions[2 + NSS_STATUS_TRYAGAIN] = action;
 688                   new_service->actions[2 + NSS_STATUS_UNAVAIL] = action;
 689                   new_service->actions[2 + NSS_STATUS_NOTFOUND] = action;
 690                   new_service->actions[2 + NSS_STATUS_SUCCESS] = action;
 691                   new_service->actions[2 + status] = save;
 692                 }
 693               else
 694                 new_service->actions[2 + status] = action;
 695
 696               /* Skip white spaces.  */
 697               while (isspace (line[0]))
 698                 ++line;
 699             }
 700           while (line[0] != ']');
 701
 702           /* Skip the ']'.  */
 703           ++line;
 704         }
 705
 706       *nextp = new_service;
 707       nextp = &new_service->next;
 708     }
 709 }
 710
 711 static name_database_entry *
 712 internal_function
 713 nss_getline (char *line)
 714 {
 715   const char *name;
 716   name_database_entry *result;
 717   size_t len;
 718
 719   /* Ignore leading white spaces.  ATTENTION: this is different from
 720      what is implemented in Solaris.  The Solaris man page says a line
 721      beginning with a white space character is ignored.  We regard
 722      this as just another misfeature in Solaris.  */
 723   while (isspace (line[0]))
 724     ++line;
 725
 726   /* Recognize `<database> ":"'.  */
 727   name = line;
 728   while (line[0] != '\0' && !isspace (line[0]) && line[0] != ':')
 729     ++line;
 730   if (line[0] == '\0' || name == line)
 731     /* Syntax error.  */
 732     return NULL;
 733   *line++ = '\0';
 734
 735   len = strlen (name) + 1;
 736
 737   result = (name_database_entry *) malloc (sizeof (name_database_entry) + len);
 738   if (result == NULL)
 739     return NULL;
 740
 741   /* Save the database name.  */
 742   memcpy (result->name, name, len);
 743
 744   /* Parse the list of services.  */
 745   result->service = nss_parse_service_list (line);
 746
 747   result->next = NULL;
 748   return result;
 749 }
 750
 751
 752 static service_library *
 753 internal_function
 754 nss_new_service (name_database *database, const char *name)
 755 {
 756   service_library **currentp = &database->library;
 757
 758   while (*currentp != NULL)
 759     {
 760       if (strcmp ((*currentp)->name, name) == 0)
 761         return *currentp;
 762       currentp = &(*currentp)->next;
 763     }
 764
 765   /* We have to add the new service.  */
 766   *currentp = (service_library *) malloc (sizeof (service_library));
 767   if (*currentp == NULL)
 768     return NULL;
 769
 770   (*currentp)->name = name;
 771   (*currentp)->lib_handle = NULL;
 772   (*currentp)->next = NULL;
 773
 774   return *currentp;
 775 }
 776
 777
 778 #ifdef SHARED
 779 /* Load all libraries for the service.  */
 780 static void
 781 nss_load_all_libraries (const char *service, const char *def)
 782 {
 783   service_user *ni = NULL;
 784
 785   if (__nss_database_lookup (service, NULL, def, &ni) == 0)
 786     while (ni != NULL)
 787       {
 788         nss_load_library (ni);
 789         ni = ni->next;
 790       }
 791 }
 792
 793
 794 /* Called by nscd and nscd alone.  */
 795 void
 796 __nss_disable_nscd (void (*cb) (size_t, struct traced_file *))
 797 {
 798 # ifdef PTR_MANGLE
 799   PTR_MANGLE (cb);
 800 # endif
 801   nscd_init_cb = cb;
 802   is_nscd = true;
 803
 804   /* Find all the relevant modules so that the init functions are called.  */
 805   nss_load_all_libraries ("passwd", "compat [NOTFOUND=return] files");
 806   nss_load_all_libraries ("group", "compat [NOTFOUND=return] files");
 807   nss_load_all_libraries ("hosts", "dns [!UNAVAIL=return] files");
 808   nss_load_all_libraries ("services", NULL);
 809
 810   /* Disable all uses of NSCD.  */
 811   __nss_not_use_nscd_passwd = -1;
 812   __nss_not_use_nscd_group = -1;
 813   __nss_not_use_nscd_hosts = -1;
 814   __nss_not_use_nscd_services = -1;
 815   __nss_not_use_nscd_netgroup = -1;
 816 }
 817 #endif
 818
 819
 820 /* Free all resources if necessary.  */
 821 libc_freeres_fn (free_mem)
 822 {
 823   name_database *top = service_table;
 824   name_database_entry *entry;
 825   service_library *library;
 826
 827   if (top == NULL)
 828     /* Maybe we have not read the nsswitch.conf file.  */
 829     return;
 830
 831   /* Don't disturb ongoing other threads (if there are any).  */
 832   service_table = NULL;
 833
 834   entry = top->entry;
 835   while (entry != NULL)
 836     {
 837       name_database_entry *olde = entry;
 838       service_user *service = entry->service;
 839
 840       while (service != NULL)
 841         {
 842           service_user *olds = service;
 843
 844           if (service->known != NULL)
 845             __tdestroy (service->known, free);
 846
 847           service = service->next;
 848           free (olds);
 849         }
 850
 851       entry = entry->next;
 852       free (olde);
 853     }
 854
 855   library = top->library;
 856   while (library != NULL)
 857     {
 858       service_library *oldl = library;
 859
 860       if (library->lib_handle && library->lib_handle != (void *) -1l)
 861         __libc_dlclose (library->lib_handle);
 862
 863       library = library->next;
 864       free (oldl);
 865     }
 866
 867   free (top);
 868 }