nss/nsswitch.c

   1 /* Copyright (C) 1996-2018 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    <http://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 #ifdef LINK_OBSOLETE_NSL
  46 # define DEFAULT_CONFIG    "compat [NOTFOUND=return] files"
  47 # define DEFAULT_DEFCONFIG "nis [NOTFOUND=return] files"
  48 #else
  49 # define DEFAULT_CONFIG    "files"
  50 # define DEFAULT_DEFCONFIG "files"
  51 #endif
  52
  53 /* Prototypes for the local functions.  */
  54 static name_database *nss_parse_file (const char *fname);
  55 static name_database_entry *nss_getline (char *line);
  56 static service_user *nss_parse_service_list (const char *line);
  57 #if !defined DO_STATIC_NSS || defined SHARED
  58 static service_library *nss_new_service (name_database *database,
  59                                          const char *name);
  60 #endif
  61
  62
  63 /* Declare external database variables.  */
  64 #define DEFINE_DATABASE(name)                                                 \
  65   service_user *__nss_##name##_database attribute_hidden;                     \
  66   weak_extern (__nss_##name##_database)
  67 #include "databases.def"
  68 #undef DEFINE_DATABASE
  69
  70 /* Structure to map database name to variable.  */
  71 static const struct
  72 {
  73   const char name[10];
  74   service_user **dbp;
  75 } databases[] =
  76 {
  77 #define DEFINE_DATABASE(name)                                                 \
  78   { #name, &__nss_##name##_database },
  79 #include "databases.def"
  80 #undef DEFINE_DATABASE
  81 };
  82 #define ndatabases (sizeof (databases) / sizeof (databases[0]))
  83
  84 #ifdef USE_NSCD
  85 /* Flags whether custom rules for database is set.  */
  86 bool __nss_database_custom[NSS_DBSIDX_max];
  87 #endif
  88
  89
  90 __libc_lock_define_initialized (static, lock)
  91
  92 #if !defined DO_STATIC_NSS || defined SHARED
  93 /* String with revision number of the shared object files.  */
  94 static const char *const __nss_shlib_revision = LIBNSS_FILES_SO + 15;
  95 #endif
  96
  97 /* The root of the whole data base.  */
  98 static name_database *service_table;
  99
 100 /* List of default service lists that were generated by glibc because
 101    /etc/nsswitch.conf did not provide a value.
 102    The list is only maintained so we can free such service lists in
 103    __libc_freeres.  */
 104 static name_database_entry *defconfig_entries;
 105
 106
 107 #if defined USE_NSCD && (!defined DO_STATIC_NSS || defined SHARED)
 108 /* Nonzero if this is the nscd process.  */
 109 static bool is_nscd;
 110 /* The callback passed to the init functions when nscd is used.  */
 111 static void (*nscd_init_cb) (size_t, struct traced_file *);
 112 #endif
 113
 114
 115 /* -1 == database not found
 116     0 == database entry pointer stored */
 117 int
 118 __nss_database_lookup (const char *database, const char *alternate_name,
 119                        const char *defconfig, service_user **ni)
 120 {
 121   /* Prevent multiple threads to change the service table.  */
 122   __libc_lock_lock (lock);
 123
 124   /* Reconsider database variable in case some other thread called
 125      `__nss_configure_lookup' while we waited for the lock.  */
 126   if (*ni != NULL)
 127     {
 128       __libc_lock_unlock (lock);
 129       return 0;
 130     }
 131
 132   /* Are we initialized yet?  */
 133   if (service_table == NULL)
 134     /* Read config file.  */
 135     service_table = nss_parse_file (_PATH_NSSWITCH_CONF);
 136
 137   /* Test whether configuration data is available.  */
 138   if (service_table != NULL)
 139     {
 140       /* Return first `service_user' entry for DATABASE.  */
 141       name_database_entry *entry;
 142
 143       /* XXX Could use some faster mechanism here.  But each database is
 144          only requested once and so this might not be critical.  */
 145       for (entry = service_table->entry; entry != NULL; entry = entry->next)
 146         if (strcmp (database, entry->name) == 0)
 147           *ni = entry->service;
 148
 149       if (*ni == NULL && alternate_name != NULL)
 150         /* We haven't found an entry so far.  Try to find it with the
 151            alternative name.  */
 152         for (entry = service_table->entry; entry != NULL; entry = entry->next)
 153           if (strcmp (alternate_name, entry->name) == 0)
 154             *ni = entry->service;
 155     }
 156
 157   /* No configuration data is available, either because nsswitch.conf
 158      doesn't exist or because it doesn't have a line for this database.
 159
 160      DEFCONFIG specifies the default service list for this database,
 161      or null to use the most common default.  */
 162   if (*ni == NULL)
 163     {
 164       *ni = nss_parse_service_list (defconfig ?: DEFAULT_DEFCONFIG);
 165       if (*ni != NULL)
 166         {
 167           /* Record the memory we've just allocated in defconfig_entries list,
 168              so we can free it later.  */
 169           name_database_entry *entry;
 170
 171           /* Allocate ENTRY plus size of name (1 here).  */
 172           entry = (name_database_entry *) malloc (sizeof (*entry) + 1);
 173
 174           if (entry != NULL)
 175             {
 176               entry->next = defconfig_entries;
 177               entry->service = *ni;
 178               entry->name[0] = '\0';
 179               defconfig_entries = entry;
 180             }
 181         }
 182     }
 183
 184   __libc_lock_unlock (lock);
 185
 186   return *ni != NULL ? 0 : -1;
 187 }
 188 libc_hidden_def (__nss_database_lookup)
 189
 190
 191 /* -1 == not found
 192     0 == function found
 193     1 == finished */
 194 int
 195 __nss_lookup (service_user **ni, const char *fct_name, const char *fct2_name,
 196               void **fctp)
 197 {
 198   *fctp = __nss_lookup_function (*ni, fct_name);
 199   if (*fctp == NULL && fct2_name != NULL)
 200     *fctp = __nss_lookup_function (*ni, fct2_name);
 201
 202   while (*fctp == NULL
 203          && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_CONTINUE
 204          && (*ni)->next != NULL)
 205     {
 206       *ni = (*ni)->next;
 207
 208       *fctp = __nss_lookup_function (*ni, fct_name);
 209       if (*fctp == NULL && fct2_name != NULL)
 210         *fctp = __nss_lookup_function (*ni, fct2_name);
 211     }
 212
 213   return *fctp != NULL ? 0 : (*ni)->next == NULL ? 1 : -1;
 214 }
 215 libc_hidden_def (__nss_lookup)
 216
 217
 218 /* -1 == not found
 219     0 == adjusted for next function
 220     1 == finished */
 221 int
 222 __nss_next2 (service_user **ni, const char *fct_name, const char *fct2_name,
 223              void **fctp, int status, int all_values)
 224 {
 225   if (all_values)
 226     {
 227       if (nss_next_action (*ni, NSS_STATUS_TRYAGAIN) == NSS_ACTION_RETURN
 228           && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_RETURN
 229           && nss_next_action (*ni, NSS_STATUS_NOTFOUND) == NSS_ACTION_RETURN
 230           && nss_next_action (*ni, NSS_STATUS_SUCCESS) == NSS_ACTION_RETURN)
 231         return 1;
 232     }
 233   else
 234     {
 235       /* This is really only for debugging.  */
 236       if (__builtin_expect (NSS_STATUS_TRYAGAIN > status
 237                             || status > NSS_STATUS_RETURN, 0))
 238          __libc_fatal ("Illegal status in __nss_next.\n");
 239
 240        if (nss_next_action (*ni, status) == NSS_ACTION_RETURN)
 241          return 1;
 242     }
 243
 244   if ((*ni)->next == NULL)
 245     return -1;
 246
 247   do
 248     {
 249       *ni = (*ni)->next;
 250
 251       *fctp = __nss_lookup_function (*ni, fct_name);
 252       if (*fctp == NULL && fct2_name != NULL)
 253         *fctp = __nss_lookup_function (*ni, fct2_name);
 254     }
 255   while (*fctp == NULL
 256          && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_CONTINUE
 257          && (*ni)->next != NULL);
 258
 259   return *fctp != NULL ? 0 : -1;
 260 }
 261 libc_hidden_def (__nss_next2)
 262
 263
 264 int
 265 attribute_compat_text_section
 266 __nss_next (service_user **ni, const char *fct_name, void **fctp, int status,
 267             int all_values)
 268 {
 269   return __nss_next2 (ni, fct_name, NULL, fctp, status, all_values);
 270 }
 271
 272
 273 int
 274 __nss_configure_lookup (const char *dbname, const char *service_line)
 275 {
 276   service_user *new_db;
 277   size_t cnt;
 278
 279   for (cnt = 0; cnt < ndatabases; ++cnt)
 280     {
 281       int cmp = strcmp (dbname, databases[cnt].name);
 282       if (cmp == 0)
 283         break;
 284       if (cmp < 0)
 285         {
 286           __set_errno (EINVAL);
 287           return -1;
 288         }
 289     }
 290
 291   if (cnt == ndatabases)
 292     {
 293       __set_errno (EINVAL);
 294       return -1;
 295     }
 296
 297   /* Test whether it is really used.  */
 298   if (databases[cnt].dbp == NULL)
 299     /* Nothing to do, but we could do.  */
 300     return 0;
 301
 302   /* Try to generate new data.  */
 303   new_db = nss_parse_service_list (service_line);
 304   if (new_db == NULL)
 305     {
 306       /* Illegal service specification.  */
 307       __set_errno (EINVAL);
 308       return -1;
 309     }
 310
 311   /* Prevent multiple threads to change the service table.  */
 312   __libc_lock_lock (lock);
 313
 314   /* Install new rules.  */
 315   *databases[cnt].dbp = new_db;
 316 #ifdef USE_NSCD
 317   __nss_database_custom[cnt] = true;
 318 #endif
 319
 320   __libc_lock_unlock (lock);
 321
 322   return 0;
 323 }
 324
 325
 326 /* Comparison function for searching NI->known tree.  */
 327 static int
 328 known_compare (const void *p1, const void *p2)
 329 {
 330   return p1 == p2 ? 0 : strcmp (*(const char *const *) p1,
 331                                 *(const char *const *) p2);
 332 }
 333
 334
 335 #if !defined DO_STATIC_NSS || defined SHARED
 336 /* Load library.  */
 337 static int
 338 nss_load_library (service_user *ni)
 339 {
 340   if (ni->library == NULL)
 341     {
 342       /* This service has not yet been used.  Fetch the service
 343          library for it, creating a new one if need be.  If there
 344          is no service table from the file, this static variable
 345          holds the head of the service_library list made from the
 346          default configuration.  */
 347       static name_database default_table;
 348       ni->library = nss_new_service (service_table ?: &default_table,
 349                                      ni->name);
 350       if (ni->library == NULL)
 351         return -1;
 352     }
 353
 354   if (ni->library->lib_handle == NULL)
 355     {
 356       /* Load the shared library.  */
 357       size_t shlen = (7 + strlen (ni->name) + 3
 358                       + strlen (__nss_shlib_revision) + 1);
 359       int saved_errno = errno;
 360       char shlib_name[shlen];
 361
 362       /* Construct shared object name.  */
 363       __stpcpy (__stpcpy (__stpcpy (__stpcpy (shlib_name,
 364                                               "libnss_"),
 365                                     ni->name),
 366                           ".so"),
 367                 __nss_shlib_revision);
 368
 369       ni->library->lib_handle = __libc_dlopen (shlib_name);
 370       if (ni->library->lib_handle == NULL)
 371         {
 372           /* Failed to load the library.  */
 373           ni->library->lib_handle = (void *) -1l;
 374           __set_errno (saved_errno);
 375         }
 376 # ifdef USE_NSCD
 377       else if (is_nscd)
 378         {
 379           /* Call the init function when nscd is used.  */
 380           size_t initlen = (5 + strlen (ni->name)
 381                             + strlen ("_init") + 1);
 382           char init_name[initlen];
 383
 384           /* Construct the init function name.  */
 385           __stpcpy (__stpcpy (__stpcpy (init_name,
 386                                         "_nss_"),
 387                               ni->name),
 388                     "_init");
 389
 390           /* Find the optional init function.  */
 391           void (*ifct) (void (*) (size_t, struct traced_file *))
 392             = __libc_dlsym (ni->library->lib_handle, init_name);
 393           if (ifct != NULL)
 394             {
 395               void (*cb) (size_t, struct traced_file *) = nscd_init_cb;
 396 #  ifdef PTR_DEMANGLE
 397               PTR_DEMANGLE (cb);
 398 #  endif
 399               ifct (cb);
 400             }
 401         }
 402 # endif
 403     }
 404
 405   return 0;
 406 }
 407 #endif
 408
 409
 410 void *
 411 __nss_lookup_function (service_user *ni, const char *fct_name)
 412 {
 413   void **found, *result;
 414
 415   /* We now modify global data.  Protect it.  */
 416   __libc_lock_lock (lock);
 417
 418   /* Search the tree of functions previously requested.  Data in the
 419      tree are `known_function' structures, whose first member is a
 420      `const char *', the lookup key.  The search returns a pointer to
 421      the tree node structure; the first member of the is a pointer to
 422      our structure (i.e. what will be a `known_function'); since the
 423      first member of that is the lookup key string, &FCT_NAME is close
 424      enough to a pointer to our structure to use as a lookup key that
 425      will be passed to `known_compare' (above).  */
 426
 427   found = __tsearch (&fct_name, &ni->known, &known_compare);
 428   if (found == NULL)
 429     /* This means out-of-memory.  */
 430     result = NULL;
 431   else if (*found != &fct_name)
 432     {
 433       /* The search found an existing structure in the tree.  */
 434       result = ((known_function *) *found)->fct_ptr;
 435 #ifdef PTR_DEMANGLE
 436       PTR_DEMANGLE (result);
 437 #endif
 438     }
 439   else
 440     {
 441       /* This name was not known before.  Now we have a node in the tree
 442          (in the proper sorted position for FCT_NAME) that points to
 443          &FCT_NAME instead of any real `known_function' structure.
 444          Allocate a new structure and fill it in.  */
 445
 446       known_function *known = malloc (sizeof *known);
 447       if (! known)
 448         {
 449 #if !defined DO_STATIC_NSS || defined SHARED
 450         remove_from_tree:
 451 #endif
 452           /* Oops.  We can't instantiate this node properly.
 453              Remove it from the tree.  */
 454           __tdelete (&fct_name, &ni->known, &known_compare);
 455           free (known);
 456           result = NULL;
 457         }
 458       else
 459         {
 460           /* Point the tree node at this new structure.  */
 461           *found = known;
 462           known->fct_name = fct_name;
 463
 464 #if !defined DO_STATIC_NSS || defined SHARED
 465           /* Load the appropriate library.  */
 466           if (nss_load_library (ni) != 0)
 467             /* This only happens when out of memory.  */
 468             goto remove_from_tree;
 469
 470           if (ni->library->lib_handle == (void *) -1l)
 471             /* Library not found => function not found.  */
 472             result = NULL;
 473           else
 474             {
 475               /* Get the desired function.  */
 476               size_t namlen = (5 + strlen (ni->name) + 1
 477                                + strlen (fct_name) + 1);
 478               char name[namlen];
 479
 480               /* Construct the function name.  */
 481               __stpcpy (__stpcpy (__stpcpy (__stpcpy (name, "_nss_"),
 482                                             ni->name),
 483                                   "_"),
 484                         fct_name);
 485
 486               /* Look up the symbol.  */
 487               result = __libc_dlsym (ni->library->lib_handle, name);
 488             }
 489 #else
 490           /* We can't get function address dynamically in static linking. */
 491           {
 492 # define DEFINE_ENT(h,nm)                                                     \
 493             { #h"_get"#nm"ent_r", _nss_##h##_get##nm##ent_r },                \
 494             { #h"_end"#nm"ent", _nss_##h##_end##nm##ent },                    \
 495             { #h"_set"#nm"ent", _nss_##h##_set##nm##ent },
 496 # define DEFINE_GET(h,nm)                                                     \
 497             { #h"_get"#nm"_r", _nss_##h##_get##nm##_r },
 498 # define DEFINE_GETBY(h,nm,ky)                                                \
 499             { #h"_get"#nm"by"#ky"_r", _nss_##h##_get##nm##by##ky##_r },
 500             static struct fct_tbl { const char *fname; void *fp; } *tp, tbl[] =
 501               {
 502 # include "function.def"
 503                 { NULL, NULL }
 504               };
 505             size_t namlen = (5 + strlen (ni->name) + 1
 506                              + strlen (fct_name) + 1);
 507             char name[namlen];
 508
 509             /* Construct the function name.  */
 510             __stpcpy (__stpcpy (__stpcpy (name, ni->name),
 511                                 "_"),
 512                       fct_name);
 513
 514             result = NULL;
 515             for (tp = &tbl[0]; tp->fname; tp++)
 516               if (strcmp (tp->fname, name) == 0)
 517                 {
 518                   result = tp->fp;
 519                   break;
 520                 }
 521           }
 522 #endif
 523
 524           /* Remember function pointer for later calls.  Even if null, we
 525              record it so a second try needn't search the library again.  */
 526           known->fct_ptr = result;
 527 #ifdef PTR_MANGLE
 528           PTR_MANGLE (known->fct_ptr);
 529 #endif
 530         }
 531     }
 532
 533   /* Remove the lock.  */
 534   __libc_lock_unlock (lock);
 535
 536   return result;
 537 }
 538 libc_hidden_def (__nss_lookup_function)
 539
 540
 541 static name_database *
 542 nss_parse_file (const char *fname)
 543 {
 544   FILE *fp;
 545   name_database *result;
 546   name_database_entry *last;
 547   char *line;
 548   size_t len;
 549
 550   /* Open the configuration file.  */
 551   fp = fopen (fname, "rce");
 552   if (fp == NULL)
 553     return NULL;
 554
 555   /* No threads use this stream.  */
 556   __fsetlocking (fp, FSETLOCKING_BYCALLER);
 557
 558   result = (name_database *) malloc (sizeof (name_database));
 559   if (result == NULL)
 560     {
 561       fclose (fp);
 562       return NULL;
 563     }
 564
 565   result->entry = NULL;
 566   result->library = NULL;
 567   last = NULL;
 568   line = NULL;
 569   len = 0;
 570   do
 571     {
 572       name_database_entry *this;
 573       ssize_t n;
 574
 575       n = __getline (&line, &len, fp);
 576       if (n < 0)
 577         break;
 578       if (line[n - 1] == '\n')
 579         line[n - 1] = '\0';
 580
 581       /* Because the file format does not know any form of quoting we
 582          can search forward for the next '#' character and if found
 583          make it terminating the line.  */
 584       *__strchrnul (line, '#') = '\0';
 585
 586       /* If the line is blank it is ignored.  */
 587       if (line[0] == '\0')
 588         continue;
 589
 590       /* Each line completely specifies the actions for a database.  */
 591       this = nss_getline (line);
 592       if (this != NULL)
 593         {
 594           if (last != NULL)
 595             last->next = this;
 596           else
 597             result->entry = this;
 598
 599           last = this;
 600         }
 601     }
 602   while (!__feof_unlocked (fp));
 603
 604   /* Free the buffer.  */
 605   free (line);
 606   /* Close configuration file.  */
 607   fclose (fp);
 608
 609   return result;
 610 }
 611
 612
 613 /* Read the source names:
 614         `( <source> ( "[" "!"? (<status> "=" <action> )+ "]" )? )*'
 615    */
 616 static service_user *
 617 nss_parse_service_list (const char *line)
 618 {
 619   service_user *result = NULL, **nextp = &result;
 620
 621   while (1)
 622     {
 623       service_user *new_service;
 624       const char *name;
 625
 626       while (isspace (line[0]))
 627         ++line;
 628       if (line[0] == '\0')
 629         /* No source specified.  */
 630         return result;
 631
 632       /* Read <source> identifier.  */
 633       name = line;
 634       while (line[0] != '\0' && !isspace (line[0]) && line[0] != '[')
 635         ++line;
 636       if (name == line)
 637         return result;
 638
 639
 640       new_service = (service_user *) malloc (sizeof (service_user)
 641                                              + (line - name + 1));
 642       if (new_service == NULL)
 643         return result;
 644
 645       *((char *) __mempcpy (new_service->name, name, line - name)) = '\0';
 646
 647       /* Set default actions.  */
 648       new_service->actions[2 + NSS_STATUS_TRYAGAIN] = NSS_ACTION_CONTINUE;
 649       new_service->actions[2 + NSS_STATUS_UNAVAIL] = NSS_ACTION_CONTINUE;
 650       new_service->actions[2 + NSS_STATUS_NOTFOUND] = NSS_ACTION_CONTINUE;
 651       new_service->actions[2 + NSS_STATUS_SUCCESS] = NSS_ACTION_RETURN;
 652       new_service->actions[2 + NSS_STATUS_RETURN] = NSS_ACTION_RETURN;
 653       new_service->library = NULL;
 654       new_service->known = NULL;
 655       new_service->next = NULL;
 656
 657       while (isspace (line[0]))
 658         ++line;
 659
 660       if (line[0] == '[')
 661         {
 662           /* Read criterions.  */
 663           do
 664             ++line;
 665           while (line[0] != '\0' && isspace (line[0]));
 666
 667           do
 668             {
 669               int not;
 670               enum nss_status status;
 671               lookup_actions action;
 672
 673               /* Grok ! before name to mean all statii but that one.  */
 674               not = line[0] == '!';
 675               if (not)
 676                 ++line;
 677
 678               /* Read status name.  */
 679               name = line;
 680               while (line[0] != '\0' && !isspace (line[0]) && line[0] != '='
 681                      && line[0] != ']')
 682                 ++line;
 683
 684               /* Compare with known statii.  */
 685               if (line - name == 7)
 686                 {
 687                   if (__strncasecmp (name, "SUCCESS", 7) == 0)
 688                     status = NSS_STATUS_SUCCESS;
 689                   else if (__strncasecmp (name, "UNAVAIL", 7) == 0)
 690                     status = NSS_STATUS_UNAVAIL;
 691                   else
 692                     goto finish;
 693                 }
 694               else if (line - name == 8)
 695                 {
 696                   if (__strncasecmp (name, "NOTFOUND", 8) == 0)
 697                     status = NSS_STATUS_NOTFOUND;
 698                   else if (__strncasecmp (name, "TRYAGAIN", 8) == 0)
 699                     status = NSS_STATUS_TRYAGAIN;
 700                   else
 701                     goto finish;
 702                 }
 703               else
 704                 goto finish;
 705
 706               while (isspace (line[0]))
 707                 ++line;
 708               if (line[0] != '=')
 709                 goto finish;
 710               do
 711                 ++line;
 712               while (isspace (line[0]));
 713
 714               name = line;
 715               while (line[0] != '\0' && !isspace (line[0]) && line[0] != '='
 716                      && line[0] != ']')
 717                 ++line;
 718
 719               if (line - name == 6 && __strncasecmp (name, "RETURN", 6) == 0)
 720                 action = NSS_ACTION_RETURN;
 721               else if (line - name == 8
 722                        && __strncasecmp (name, "CONTINUE", 8) == 0)
 723                 action = NSS_ACTION_CONTINUE;
 724               else if (line - name == 5
 725                        && __strncasecmp (name, "MERGE", 5) == 0)
 726                 action = NSS_ACTION_MERGE;
 727               else
 728                 goto finish;
 729
 730               if (not)
 731                 {
 732                   /* Save the current action setting for this status,
 733                      set them all to the given action, and reset this one.  */
 734                   const lookup_actions save = new_service->actions[2 + status];
 735                   new_service->actions[2 + NSS_STATUS_TRYAGAIN] = action;
 736                   new_service->actions[2 + NSS_STATUS_UNAVAIL] = action;
 737                   new_service->actions[2 + NSS_STATUS_NOTFOUND] = action;
 738                   new_service->actions[2 + NSS_STATUS_SUCCESS] = action;
 739                   new_service->actions[2 + status] = save;
 740                 }
 741               else
 742                 new_service->actions[2 + status] = action;
 743
 744               /* Skip white spaces.  */
 745               while (isspace (line[0]))
 746                 ++line;
 747             }
 748           while (line[0] != ']');
 749
 750           /* Skip the ']'.  */
 751           ++line;
 752         }
 753
 754       *nextp = new_service;
 755       nextp = &new_service->next;
 756       continue;
 757
 758     finish:
 759       free (new_service);
 760       return result;
 761     }
 762 }
 763
 764 static name_database_entry *
 765 nss_getline (char *line)
 766 {
 767   const char *name;
 768   name_database_entry *result;
 769   size_t len;
 770
 771   /* Ignore leading white spaces.  ATTENTION: this is different from
 772      what is implemented in Solaris.  The Solaris man page says a line
 773      beginning with a white space character is ignored.  We regard
 774      this as just another misfeature in Solaris.  */
 775   while (isspace (line[0]))
 776     ++line;
 777
 778   /* Recognize `<database> ":"'.  */
 779   name = line;
 780   while (line[0] != '\0' && !isspace (line[0]) && line[0] != ':')
 781     ++line;
 782   if (line[0] == '\0' || name == line)
 783     /* Syntax error.  */
 784     return NULL;
 785   *line++ = '\0';
 786
 787   len = strlen (name) + 1;
 788
 789   result = (name_database_entry *) malloc (sizeof (name_database_entry) + len);
 790   if (result == NULL)
 791     return NULL;
 792
 793   /* Save the database name.  */
 794   memcpy (result->name, name, len);
 795
 796   /* Parse the list of services.  */
 797   result->service = nss_parse_service_list (line);
 798
 799   result->next = NULL;
 800   return result;
 801 }
 802
 803
 804 #if !defined DO_STATIC_NSS || defined SHARED
 805 static service_library *
 806 nss_new_service (name_database *database, const char *name)
 807 {
 808   service_library **currentp = &database->library;
 809
 810   while (*currentp != NULL)
 811     {
 812       if (strcmp ((*currentp)->name, name) == 0)
 813         return *currentp;
 814       currentp = &(*currentp)->next;
 815     }
 816
 817   /* We have to add the new service.  */
 818   *currentp = (service_library *) malloc (sizeof (service_library));
 819   if (*currentp == NULL)
 820     return NULL;
 821
 822   (*currentp)->name = name;
 823   (*currentp)->lib_handle = NULL;
 824   (*currentp)->next = NULL;
 825
 826   return *currentp;
 827 }
 828 #endif
 829
 830
 831 #if defined SHARED && defined USE_NSCD
 832 /* Load all libraries for the service.  */
 833 static void
 834 nss_load_all_libraries (const char *service, const char *def)
 835 {
 836   service_user *ni = NULL;
 837
 838   if (__nss_database_lookup (service, NULL, def, &ni) == 0)
 839     while (ni != NULL)
 840       {
 841         nss_load_library (ni);
 842         ni = ni->next;
 843       }
 844 }
 845
 846
 847 /* Called by nscd and nscd alone.  */
 848 void
 849 __nss_disable_nscd (void (*cb) (size_t, struct traced_file *))
 850 {
 851 # ifdef PTR_MANGLE
 852   PTR_MANGLE (cb);
 853 # endif
 854   nscd_init_cb = cb;
 855   is_nscd = true;
 856
 857   /* Find all the relevant modules so that the init functions are called.  */
 858   nss_load_all_libraries ("passwd", DEFAULT_CONFIG);
 859   nss_load_all_libraries ("group", DEFAULT_CONFIG);
 860   nss_load_all_libraries ("hosts", "dns [!UNAVAIL=return] files");
 861   nss_load_all_libraries ("services", NULL);
 862
 863   /* Disable all uses of NSCD.  */
 864   __nss_not_use_nscd_passwd = -1;
 865   __nss_not_use_nscd_group = -1;
 866   __nss_not_use_nscd_hosts = -1;
 867   __nss_not_use_nscd_services = -1;
 868   __nss_not_use_nscd_netgroup = -1;
 869 }
 870 #endif
 871
 872 static void
 873 free_database_entries (name_database_entry *entry)
 874 {
 875   while (entry != NULL)
 876     {
 877       name_database_entry *olde = entry;
 878       service_user *service = entry->service;
 879
 880       while (service != NULL)
 881         {
 882           service_user *olds = service;
 883
 884           if (service->known != NULL)
 885             __tdestroy (service->known, free);
 886
 887           service = service->next;
 888           free (olds);
 889         }
 890
 891       entry = entry->next;
 892       free (olde);
 893     }
 894 }
 895
 896 /* Free all resources if necessary.  */
 897 libc_freeres_fn (free_defconfig)
 898 {
 899   name_database_entry *entry = defconfig_entries;
 900
 901   if (entry == NULL)
 902     /* defconfig was not used.  */
 903     return;
 904
 905   /* Don't disturb ongoing other threads (if there are any).  */
 906   defconfig_entries = NULL;
 907
 908   free_database_entries (entry);
 909 }
 910
 911 libc_freeres_fn (free_mem)
 912 {
 913   name_database *top = service_table;
 914   service_library *library;
 915
 916   if (top == NULL)
 917     /* Maybe we have not read the nsswitch.conf file.  */
 918     return;
 919
 920   /* Don't disturb ongoing other threads (if there are any).  */
 921   service_table = NULL;
 922
 923   free_database_entries (top->entry);
 924
 925   library = top->library;
 926   while (library != NULL)
 927     {
 928       service_library *oldl = library;
 929
 930       if (library->lib_handle && library->lib_handle != (void *) -1l)
 931         __libc_dlclose (library->lib_handle);
 932
 933       library = library->next;
 934       free (oldl);
 935     }
 936
 937   free (top);
 938 }