nss/nsswitch.c

   1 /* Copyright (C) 1996-2020 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <ctype.h>
  20 #include <dlfcn.h>
  21 #include <errno.h>
  22 #include <netdb.h>
  23 #include <libc-lock.h>
  24 #include <search.h>
  25 #include <stdio.h>
  26 #include <stdio_ext.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29
  30 #include <aliases.h>
  31 #include <grp.h>
  32 #include <netinet/ether.h>
  33 #include <pwd.h>
  34 #include <shadow.h>
  35
  36 #if !defined DO_STATIC_NSS || defined SHARED
  37 # include <gnu/lib-names.h>
  38 #endif
  39
  40 #include "nsswitch.h"
  41 #include "../nscd/nscd_proto.h"
  42 #include <sysdep.h>
  43 #include <config.h>
  44
  45 /* Prototypes for the local functions.  */
  46 static name_database *nss_parse_file (const char *fname);
  47 static name_database_entry *nss_getline (char *line);
  48 static service_user *nss_parse_service_list (const char *line);
  49 #if !defined DO_STATIC_NSS || defined SHARED
  50 static service_library *nss_new_service (name_database *database,
  51                                          const char *name);
  52 #endif
  53
  54
  55 /* Declare external database variables.  */
  56 #define DEFINE_DATABASE(name)                                                 \
  57   service_user *__nss_##name##_database attribute_hidden;                     \
  58   weak_extern (__nss_##name##_database)
  59 #include "databases.def"
  60 #undef DEFINE_DATABASE
  61
  62 /* Structure to map database name to variable.  */
  63 static const struct
  64 {
  65   const char name[10];
  66   service_user **dbp;
  67 } databases[] =
  68 {
  69 #define DEFINE_DATABASE(name)                                                 \
  70   { #name, &__nss_##name##_database },
  71 #include "databases.def"
  72 #undef DEFINE_DATABASE
  73 };
  74 #define ndatabases (sizeof (databases) / sizeof (databases[0]))
  75
  76 #ifdef USE_NSCD
  77 /* Flags whether custom rules for database is set.  */
  78 bool __nss_database_custom[NSS_DBSIDX_max];
  79 #endif
  80
  81
  82 __libc_lock_define_initialized (static, lock)
  83
  84 #if !defined DO_STATIC_NSS || defined SHARED
  85 /* String with revision number of the shared object files.  */
  86 static const char *const __nss_shlib_revision = LIBNSS_FILES_SO + 15;
  87 #endif
  88
  89 /* The root of the whole data base.  */
  90 static name_database *service_table;
  91
  92 /* List of default service lists that were generated by glibc because
  93    /etc/nsswitch.conf did not provide a value.
  94    The list is only maintained so we can free such service lists in
  95    __libc_freeres.  */
  96 static name_database_entry *defconfig_entries;
  97
  98
  99 #if defined USE_NSCD && (!defined DO_STATIC_NSS || defined SHARED)
 100 /* Nonzero if this is the nscd process.  */
 101 static bool is_nscd;
 102 /* The callback passed to the init functions when nscd is used.  */
 103 static void (*nscd_init_cb) (size_t, struct traced_file *);
 104 #endif
 105
 106
 107 /* -1 == database not found
 108     0 == database entry pointer stored */
 109 int
 110 __nss_database_lookup2 (const char *database, const char *alternate_name,
 111                         const char *defconfig, service_user **ni)
 112 {
 113   /* Prevent multiple threads to change the service table.  */
 114   __libc_lock_lock (lock);
 115
 116   /* Reconsider database variable in case some other thread called
 117      `__nss_configure_lookup' while we waited for the lock.  */
 118   if (*ni != NULL)
 119     {
 120       __libc_lock_unlock (lock);
 121       return 0;
 122     }
 123
 124   /* Are we initialized yet?  */
 125   if (service_table == NULL)
 126     /* Read config file.  */
 127     service_table = nss_parse_file (_PATH_NSSWITCH_CONF);
 128
 129   /* Test whether configuration data is available.  */
 130   if (service_table != NULL)
 131     {
 132       /* Return first `service_user' entry for DATABASE.  */
 133       name_database_entry *entry;
 134
 135       /* XXX Could use some faster mechanism here.  But each database is
 136          only requested once and so this might not be critical.  */
 137       for (entry = service_table->entry; entry != NULL; entry = entry->next)
 138         if (strcmp (database, entry->name) == 0)
 139           *ni = entry->service;
 140
 141       if (*ni == NULL && alternate_name != NULL)
 142         /* We haven't found an entry so far.  Try to find it with the
 143            alternative name.  */
 144         for (entry = service_table->entry; entry != NULL; entry = entry->next)
 145           if (strcmp (alternate_name, entry->name) == 0)
 146             *ni = entry->service;
 147     }
 148
 149   /* No configuration data is available, either because nsswitch.conf
 150      doesn't exist or because it doesn't have a line for this database.
 151
 152      DEFCONFIG specifies the default service list for this database,
 153      or null to use the most common default.  */
 154   if (*ni == NULL)
 155     {
 156       *ni = nss_parse_service_list (defconfig ?: "files");
 157       if (*ni != NULL)
 158         {
 159           /* Record the memory we've just allocated in defconfig_entries list,
 160              so we can free it later.  */
 161           name_database_entry *entry;
 162
 163           /* Allocate ENTRY plus size of name (1 here).  */
 164           entry = (name_database_entry *) malloc (sizeof (*entry) + 1);
 165
 166           if (entry != NULL)
 167             {
 168               entry->next = defconfig_entries;
 169               entry->service = *ni;
 170               entry->name[0] = '\0';
 171               defconfig_entries = entry;
 172             }
 173         }
 174     }
 175
 176   __libc_lock_unlock (lock);
 177
 178   return *ni != NULL ? 0 : -1;
 179 }
 180 libc_hidden_def (__nss_database_lookup2)
 181
 182
 183 /* -1 == not found
 184     0 == function found
 185     1 == finished */
 186 int
 187 __nss_lookup (service_user **ni, const char *fct_name, const char *fct2_name,
 188               void **fctp)
 189 {
 190   *fctp = __nss_lookup_function (*ni, fct_name);
 191   if (*fctp == NULL && fct2_name != NULL)
 192     *fctp = __nss_lookup_function (*ni, fct2_name);
 193
 194   while (*fctp == NULL
 195          && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_CONTINUE
 196          && (*ni)->next != NULL)
 197     {
 198       *ni = (*ni)->next;
 199
 200       *fctp = __nss_lookup_function (*ni, fct_name);
 201       if (*fctp == NULL && fct2_name != NULL)
 202         *fctp = __nss_lookup_function (*ni, fct2_name);
 203     }
 204
 205   return *fctp != NULL ? 0 : (*ni)->next == NULL ? 1 : -1;
 206 }
 207 libc_hidden_def (__nss_lookup)
 208
 209
 210 /* -1 == not found
 211     0 == adjusted for next function
 212     1 == finished */
 213 int
 214 __nss_next2 (service_user **ni, const char *fct_name, const char *fct2_name,
 215              void **fctp, int status, int all_values)
 216 {
 217   if (all_values)
 218     {
 219       if (nss_next_action (*ni, NSS_STATUS_TRYAGAIN) == NSS_ACTION_RETURN
 220           && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_RETURN
 221           && nss_next_action (*ni, NSS_STATUS_NOTFOUND) == NSS_ACTION_RETURN
 222           && nss_next_action (*ni, NSS_STATUS_SUCCESS) == NSS_ACTION_RETURN)
 223         return 1;
 224     }
 225   else
 226     {
 227       /* This is really only for debugging.  */
 228       if (__builtin_expect (NSS_STATUS_TRYAGAIN > status
 229                             || status > NSS_STATUS_RETURN, 0))
 230          __libc_fatal ("Illegal status in __nss_next.\n");
 231
 232        if (nss_next_action (*ni, status) == NSS_ACTION_RETURN)
 233          return 1;
 234     }
 235
 236   if ((*ni)->next == NULL)
 237     return -1;
 238
 239   do
 240     {
 241       *ni = (*ni)->next;
 242
 243       *fctp = __nss_lookup_function (*ni, fct_name);
 244       if (*fctp == NULL && fct2_name != NULL)
 245         *fctp = __nss_lookup_function (*ni, fct2_name);
 246     }
 247   while (*fctp == NULL
 248          && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_CONTINUE
 249          && (*ni)->next != NULL);
 250
 251   return *fctp != NULL ? 0 : -1;
 252 }
 253 libc_hidden_def (__nss_next2)
 254
 255 int
 256 __nss_configure_lookup (const char *dbname, const char *service_line)
 257 {
 258   service_user *new_db;
 259   size_t cnt;
 260
 261   for (cnt = 0; cnt < ndatabases; ++cnt)
 262     {
 263       int cmp = strcmp (dbname, databases[cnt].name);
 264       if (cmp == 0)
 265         break;
 266       if (cmp < 0)
 267         {
 268           __set_errno (EINVAL);
 269           return -1;
 270         }
 271     }
 272
 273   if (cnt == ndatabases)
 274     {
 275       __set_errno (EINVAL);
 276       return -1;
 277     }
 278
 279   /* Test whether it is really used.  */
 280   if (databases[cnt].dbp == NULL)
 281     /* Nothing to do, but we could do.  */
 282     return 0;
 283
 284   /* Try to generate new data.  */
 285   new_db = nss_parse_service_list (service_line);
 286   if (new_db == NULL)
 287     {
 288       /* Illegal service specification.  */
 289       __set_errno (EINVAL);
 290       return -1;
 291     }
 292
 293   /* Prevent multiple threads to change the service table.  */
 294   __libc_lock_lock (lock);
 295
 296   /* Install new rules.  */
 297   *databases[cnt].dbp = new_db;
 298 #ifdef USE_NSCD
 299   __nss_database_custom[cnt] = true;
 300 #endif
 301
 302   __libc_lock_unlock (lock);
 303
 304   return 0;
 305 }
 306
 307
 308 /* Comparison function for searching NI->known tree.  */
 309 static int
 310 known_compare (const void *p1, const void *p2)
 311 {
 312   return p1 == p2 ? 0 : strcmp (*(const char *const *) p1,
 313                                 *(const char *const *) p2);
 314 }
 315
 316
 317 #if !defined DO_STATIC_NSS || defined SHARED
 318 /* Load library.  */
 319 static int
 320 nss_load_library (service_user *ni)
 321 {
 322   if (ni->library == NULL)
 323     {
 324       /* This service has not yet been used.  Fetch the service
 325          library for it, creating a new one if need be.  If there
 326          is no service table from the file, this static variable
 327          holds the head of the service_library list made from the
 328          default configuration.  */
 329       static name_database default_table;
 330       ni->library = nss_new_service (service_table ?: &default_table,
 331                                      ni->name);
 332       if (ni->library == NULL)
 333         return -1;
 334     }
 335
 336   if (ni->library->lib_handle == NULL)
 337     {
 338       /* Load the shared library.  */
 339       size_t shlen = (7 + strlen (ni->name) + 3
 340                       + strlen (__nss_shlib_revision) + 1);
 341       int saved_errno = errno;
 342       char shlib_name[shlen];
 343
 344       /* Construct shared object name.  */
 345       __stpcpy (__stpcpy (__stpcpy (__stpcpy (shlib_name,
 346                                               "libnss_"),
 347                                     ni->name),
 348                           ".so"),
 349                 __nss_shlib_revision);
 350
 351       ni->library->lib_handle = __libc_dlopen (shlib_name);
 352       if (ni->library->lib_handle == NULL)
 353         {
 354           /* Failed to load the library.  */
 355           ni->library->lib_handle = (void *) -1l;
 356           __set_errno (saved_errno);
 357         }
 358 # ifdef USE_NSCD
 359       else if (is_nscd)
 360         {
 361           /* Call the init function when nscd is used.  */
 362           size_t initlen = (5 + strlen (ni->name)
 363                             + strlen ("_init") + 1);
 364           char init_name[initlen];
 365
 366           /* Construct the init function name.  */
 367           __stpcpy (__stpcpy (__stpcpy (init_name,
 368                                         "_nss_"),
 369                               ni->name),
 370                     "_init");
 371
 372           /* Find the optional init function.  */
 373           void (*ifct) (void (*) (size_t, struct traced_file *))
 374             = __libc_dlsym (ni->library->lib_handle, init_name);
 375           if (ifct != NULL)
 376             {
 377               void (*cb) (size_t, struct traced_file *) = nscd_init_cb;
 378 #  ifdef PTR_DEMANGLE
 379               PTR_DEMANGLE (cb);
 380 #  endif
 381               ifct (cb);
 382             }
 383         }
 384 # endif
 385     }
 386
 387   return 0;
 388 }
 389 #endif
 390
 391
 392 void *
 393 __nss_lookup_function (service_user *ni, const char *fct_name)
 394 {
 395   void **found, *result;
 396
 397   /* We now modify global data.  Protect it.  */
 398   __libc_lock_lock (lock);
 399
 400   /* Search the tree of functions previously requested.  Data in the
 401      tree are `known_function' structures, whose first member is a
 402      `const char *', the lookup key.  The search returns a pointer to
 403      the tree node structure; the first member of the is a pointer to
 404      our structure (i.e. what will be a `known_function'); since the
 405      first member of that is the lookup key string, &FCT_NAME is close
 406      enough to a pointer to our structure to use as a lookup key that
 407      will be passed to `known_compare' (above).  */
 408
 409   found = __tsearch (&fct_name, &ni->known, &known_compare);
 410   if (found == NULL)
 411     /* This means out-of-memory.  */
 412     result = NULL;
 413   else if (*found != &fct_name)
 414     {
 415       /* The search found an existing structure in the tree.  */
 416       result = ((known_function *) *found)->fct_ptr;
 417 #ifdef PTR_DEMANGLE
 418       PTR_DEMANGLE (result);
 419 #endif
 420     }
 421   else
 422     {
 423       /* This name was not known before.  Now we have a node in the tree
 424          (in the proper sorted position for FCT_NAME) that points to
 425          &FCT_NAME instead of any real `known_function' structure.
 426          Allocate a new structure and fill it in.  */
 427
 428       known_function *known = malloc (sizeof *known);
 429       if (! known)
 430         {
 431 #if !defined DO_STATIC_NSS || defined SHARED
 432         remove_from_tree:
 433 #endif
 434           /* Oops.  We can't instantiate this node properly.
 435              Remove it from the tree.  */
 436           __tdelete (&fct_name, &ni->known, &known_compare);
 437           free (known);
 438           result = NULL;
 439         }
 440       else
 441         {
 442           /* Point the tree node at this new structure.  */
 443           *found = known;
 444           known->fct_name = fct_name;
 445
 446 #if !defined DO_STATIC_NSS || defined SHARED
 447           /* Load the appropriate library.  */
 448           if (nss_load_library (ni) != 0)
 449             /* This only happens when out of memory.  */
 450             goto remove_from_tree;
 451
 452           if (ni->library->lib_handle == (void *) -1l)
 453             /* Library not found => function not found.  */
 454             result = NULL;
 455           else
 456             {
 457               /* Get the desired function.  */
 458               size_t namlen = (5 + strlen (ni->name) + 1
 459                                + strlen (fct_name) + 1);
 460               char name[namlen];
 461
 462               /* Construct the function name.  */
 463               __stpcpy (__stpcpy (__stpcpy (__stpcpy (name, "_nss_"),
 464                                             ni->name),
 465                                   "_"),
 466                         fct_name);
 467
 468               /* Look up the symbol.  */
 469               result = __libc_dlsym (ni->library->lib_handle, name);
 470             }
 471 #else
 472           /* We can't get function address dynamically in static linking. */
 473           {
 474 # define DEFINE_ENT(h,nm)                                                     \
 475             { #h"_get"#nm"ent_r", _nss_##h##_get##nm##ent_r },                \
 476             { #h"_end"#nm"ent", _nss_##h##_end##nm##ent },                    \
 477             { #h"_set"#nm"ent", _nss_##h##_set##nm##ent },
 478 # define DEFINE_GET(h,nm)                                                     \
 479             { #h"_get"#nm"_r", _nss_##h##_get##nm##_r },
 480 # define DEFINE_GETBY(h,nm,ky)                                                \
 481             { #h"_get"#nm"by"#ky"_r", _nss_##h##_get##nm##by##ky##_r },
 482             static struct fct_tbl { const char *fname; void *fp; } *tp, tbl[] =
 483               {
 484 # include "function.def"
 485                 { NULL, NULL }
 486               };
 487             size_t namlen = (5 + strlen (ni->name) + 1
 488                              + strlen (fct_name) + 1);
 489             char name[namlen];
 490
 491             /* Construct the function name.  */
 492             __stpcpy (__stpcpy (__stpcpy (name, ni->name),
 493                                 "_"),
 494                       fct_name);
 495
 496             result = NULL;
 497             for (tp = &tbl[0]; tp->fname; tp++)
 498               if (strcmp (tp->fname, name) == 0)
 499                 {
 500                   result = tp->fp;
 501                   break;
 502                 }
 503           }
 504 #endif
 505
 506           /* Remember function pointer for later calls.  Even if null, we
 507              record it so a second try needn't search the library again.  */
 508           known->fct_ptr = result;
 509 #ifdef PTR_MANGLE
 510           PTR_MANGLE (known->fct_ptr);
 511 #endif
 512         }
 513     }
 514
 515   /* Remove the lock.  */
 516   __libc_lock_unlock (lock);
 517
 518   return result;
 519 }
 520 libc_hidden_def (__nss_lookup_function)
 521
 522
 523 static name_database *
 524 nss_parse_file (const char *fname)
 525 {
 526   FILE *fp;
 527   name_database *result;
 528   name_database_entry *last;
 529   char *line;
 530   size_t len;
 531
 532   /* Open the configuration file.  */
 533   fp = fopen (fname, "rce");
 534   if (fp == NULL)
 535     return NULL;
 536
 537   /* No threads use this stream.  */
 538   __fsetlocking (fp, FSETLOCKING_BYCALLER);
 539
 540   result = (name_database *) malloc (sizeof (name_database));
 541   if (result == NULL)
 542     {
 543       fclose (fp);
 544       return NULL;
 545     }
 546
 547   result->entry = NULL;
 548   result->library = NULL;
 549   last = NULL;
 550   line = NULL;
 551   len = 0;
 552   do
 553     {
 554       name_database_entry *this;
 555       ssize_t n;
 556
 557       n = __getline (&line, &len, fp);
 558       if (n < 0)
 559         break;
 560       if (line[n - 1] == '\n')
 561         line[n - 1] = '\0';
 562
 563       /* Because the file format does not know any form of quoting we
 564          can search forward for the next '#' character and if found
 565          make it terminating the line.  */
 566       *__strchrnul (line, '#') = '\0';
 567
 568       /* If the line is blank it is ignored.  */
 569       if (line[0] == '\0')
 570         continue;
 571
 572       /* Each line completely specifies the actions for a database.  */
 573       this = nss_getline (line);
 574       if (this != NULL)
 575         {
 576           if (last != NULL)
 577             last->next = this;
 578           else
 579             result->entry = this;
 580
 581           last = this;
 582         }
 583     }
 584   while (!__feof_unlocked (fp));
 585
 586   /* Free the buffer.  */
 587   free (line);
 588   /* Close configuration file.  */
 589   fclose (fp);
 590
 591   return result;
 592 }
 593
 594
 595 /* Read the source names:
 596         `( <source> ( "[" "!"? (<status> "=" <action> )+ "]" )? )*'
 597    */
 598 static service_user *
 599 nss_parse_service_list (const char *line)
 600 {
 601   service_user *result = NULL, **nextp = &result;
 602
 603   while (1)
 604     {
 605       service_user *new_service;
 606       const char *name;
 607
 608       while (isspace (line[0]))
 609         ++line;
 610       if (line[0] == '\0')
 611         /* No source specified.  */
 612         return result;
 613
 614       /* Read <source> identifier.  */
 615       name = line;
 616       while (line[0] != '\0' && !isspace (line[0]) && line[0] != '[')
 617         ++line;
 618       if (name == line)
 619         return result;
 620
 621
 622       new_service = (service_user *) malloc (sizeof (service_user)
 623                                              + (line - name + 1));
 624       if (new_service == NULL)
 625         return result;
 626
 627       *((char *) __mempcpy (new_service->name, name, line - name)) = '\0';
 628
 629       /* Set default actions.  */
 630       new_service->actions[2 + NSS_STATUS_TRYAGAIN] = NSS_ACTION_CONTINUE;
 631       new_service->actions[2 + NSS_STATUS_UNAVAIL] = NSS_ACTION_CONTINUE;
 632       new_service->actions[2 + NSS_STATUS_NOTFOUND] = NSS_ACTION_CONTINUE;
 633       new_service->actions[2 + NSS_STATUS_SUCCESS] = NSS_ACTION_RETURN;
 634       new_service->actions[2 + NSS_STATUS_RETURN] = NSS_ACTION_RETURN;
 635       new_service->library = NULL;
 636       new_service->known = NULL;
 637       new_service->next = NULL;
 638
 639       while (isspace (line[0]))
 640         ++line;
 641
 642       if (line[0] == '[')
 643         {
 644           /* Read criterions.  */
 645           do
 646             ++line;
 647           while (line[0] != '\0' && isspace (line[0]));
 648
 649           do
 650             {
 651               int not;
 652               enum nss_status status;
 653               lookup_actions action;
 654
 655               /* Grok ! before name to mean all statii but that one.  */
 656               not = line[0] == '!';
 657               if (not)
 658                 ++line;
 659
 660               /* Read status name.  */
 661               name = line;
 662               while (line[0] != '\0' && !isspace (line[0]) && line[0] != '='
 663                      && line[0] != ']')
 664                 ++line;
 665
 666               /* Compare with known statii.  */
 667               if (line - name == 7)
 668                 {
 669                   if (__strncasecmp (name, "SUCCESS", 7) == 0)
 670                     status = NSS_STATUS_SUCCESS;
 671                   else if (__strncasecmp (name, "UNAVAIL", 7) == 0)
 672                     status = NSS_STATUS_UNAVAIL;
 673                   else
 674                     goto finish;
 675                 }
 676               else if (line - name == 8)
 677                 {
 678                   if (__strncasecmp (name, "NOTFOUND", 8) == 0)
 679                     status = NSS_STATUS_NOTFOUND;
 680                   else if (__strncasecmp (name, "TRYAGAIN", 8) == 0)
 681                     status = NSS_STATUS_TRYAGAIN;
 682                   else
 683                     goto finish;
 684                 }
 685               else
 686                 goto finish;
 687
 688               while (isspace (line[0]))
 689                 ++line;
 690               if (line[0] != '=')
 691                 goto finish;
 692               do
 693                 ++line;
 694               while (isspace (line[0]));
 695
 696               name = line;
 697               while (line[0] != '\0' && !isspace (line[0]) && line[0] != '='
 698                      && line[0] != ']')
 699                 ++line;
 700
 701               if (line - name == 6 && __strncasecmp (name, "RETURN", 6) == 0)
 702                 action = NSS_ACTION_RETURN;
 703               else if (line - name == 8
 704                        && __strncasecmp (name, "CONTINUE", 8) == 0)
 705                 action = NSS_ACTION_CONTINUE;
 706               else if (line - name == 5
 707                        && __strncasecmp (name, "MERGE", 5) == 0)
 708                 action = NSS_ACTION_MERGE;
 709               else
 710                 goto finish;
 711
 712               if (not)
 713                 {
 714                   /* Save the current action setting for this status,
 715                      set them all to the given action, and reset this one.  */
 716                   const lookup_actions save = new_service->actions[2 + status];
 717                   new_service->actions[2 + NSS_STATUS_TRYAGAIN] = action;
 718                   new_service->actions[2 + NSS_STATUS_UNAVAIL] = action;
 719                   new_service->actions[2 + NSS_STATUS_NOTFOUND] = action;
 720                   new_service->actions[2 + NSS_STATUS_SUCCESS] = action;
 721                   new_service->actions[2 + status] = save;
 722                 }
 723               else
 724                 new_service->actions[2 + status] = action;
 725
 726               /* Skip white spaces.  */
 727               while (isspace (line[0]))
 728                 ++line;
 729             }
 730           while (line[0] != ']');
 731
 732           /* Skip the ']'.  */
 733           ++line;
 734         }
 735
 736       *nextp = new_service;
 737       nextp = &new_service->next;
 738       continue;
 739
 740     finish:
 741       free (new_service);
 742       return result;
 743     }
 744 }
 745
 746 static name_database_entry *
 747 nss_getline (char *line)
 748 {
 749   const char *name;
 750   name_database_entry *result;
 751   size_t len;
 752
 753   /* Ignore leading white spaces.  ATTENTION: this is different from
 754      what is implemented in Solaris.  The Solaris man page says a line
 755      beginning with a white space character is ignored.  We regard
 756      this as just another misfeature in Solaris.  */
 757   while (isspace (line[0]))
 758     ++line;
 759
 760   /* Recognize `<database> ":"'.  */
 761   name = line;
 762   while (line[0] != '\0' && !isspace (line[0]) && line[0] != ':')
 763     ++line;
 764   if (line[0] == '\0' || name == line)
 765     /* Syntax error.  */
 766     return NULL;
 767   *line++ = '\0';
 768
 769   len = strlen (name) + 1;
 770
 771   result = (name_database_entry *) malloc (sizeof (name_database_entry) + len);
 772   if (result == NULL)
 773     return NULL;
 774
 775   /* Save the database name.  */
 776   memcpy (result->name, name, len);
 777
 778   /* Parse the list of services.  */
 779   result->service = nss_parse_service_list (line);
 780
 781   result->next = NULL;
 782   return result;
 783 }
 784
 785
 786 #if !defined DO_STATIC_NSS || defined SHARED
 787 static service_library *
 788 nss_new_service (name_database *database, const char *name)
 789 {
 790   service_library **currentp = &database->library;
 791
 792   while (*currentp != NULL)
 793     {
 794       if (strcmp ((*currentp)->name, name) == 0)
 795         return *currentp;
 796       currentp = &(*currentp)->next;
 797     }
 798
 799   /* We have to add the new service.  */
 800   *currentp = (service_library *) malloc (sizeof (service_library));
 801   if (*currentp == NULL)
 802     return NULL;
 803
 804   (*currentp)->name = name;
 805   (*currentp)->lib_handle = NULL;
 806   (*currentp)->next = NULL;
 807
 808   return *currentp;
 809 }
 810 #endif
 811
 812
 813 #if defined SHARED && defined USE_NSCD
 814 /* Load all libraries for the service.  */
 815 static void
 816 nss_load_all_libraries (const char *service, const char *def)
 817 {
 818   service_user *ni = NULL;
 819
 820   if (__nss_database_lookup2 (service, NULL, def, &ni) == 0)
 821     while (ni != NULL)
 822       {
 823         nss_load_library (ni);
 824         ni = ni->next;
 825       }
 826 }
 827
 828
 829 /* Called by nscd and nscd alone.  */
 830 void
 831 __nss_disable_nscd (void (*cb) (size_t, struct traced_file *))
 832 {
 833 # ifdef PTR_MANGLE
 834   PTR_MANGLE (cb);
 835 # endif
 836   nscd_init_cb = cb;
 837   is_nscd = true;
 838
 839   /* Find all the relevant modules so that the init functions are called.  */
 840   nss_load_all_libraries ("passwd", "files");
 841   nss_load_all_libraries ("group", "files");
 842   nss_load_all_libraries ("hosts", "dns [!UNAVAIL=return] files");
 843   nss_load_all_libraries ("services", NULL);
 844
 845   /* Disable all uses of NSCD.  */
 846   __nss_not_use_nscd_passwd = -1;
 847   __nss_not_use_nscd_group = -1;
 848   __nss_not_use_nscd_hosts = -1;
 849   __nss_not_use_nscd_services = -1;
 850   __nss_not_use_nscd_netgroup = -1;
 851 }
 852 #endif
 853
 854 static void
 855 free_database_entries (name_database_entry *entry)
 856 {
 857   while (entry != NULL)
 858     {
 859       name_database_entry *olde = entry;
 860       service_user *service = entry->service;
 861
 862       while (service != NULL)
 863         {
 864           service_user *olds = service;
 865
 866           if (service->known != NULL)
 867             __tdestroy (service->known, free);
 868
 869           service = service->next;
 870           free (olds);
 871         }
 872
 873       entry = entry->next;
 874       free (olde);
 875     }
 876 }
 877
 878 /* Free all resources if necessary.  */
 879 libc_freeres_fn (free_defconfig)
 880 {
 881   name_database_entry *entry = defconfig_entries;
 882
 883   if (entry == NULL)
 884     /* defconfig was not used.  */
 885     return;
 886
 887   /* Don't disturb ongoing other threads (if there are any).  */
 888   defconfig_entries = NULL;
 889
 890   free_database_entries (entry);
 891 }
 892
 893 libc_freeres_fn (free_mem)
 894 {
 895   name_database *top = service_table;
 896   service_library *library;
 897
 898   if (top == NULL)
 899     /* Maybe we have not read the nsswitch.conf file.  */
 900     return;
 901
 902   /* Don't disturb ongoing other threads (if there are any).  */
 903   service_table = NULL;
 904
 905   free_database_entries (top->entry);
 906
 907   library = top->library;
 908   while (library != NULL)
 909     {
 910       service_library *oldl = library;
 911
 912       if (library->lib_handle && library->lib_handle != (void *) -1l)
 913         __libc_dlclose (library->lib_handle);
 914
 915       library = library->next;
 916       free (oldl);
 917     }
 918
 919   free (top);
 920 }