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, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <ctype.h>
  22 #include <dlfcn.h>
  23 #include <errno.h>
  24 #include <netdb.h>
  25 #include <bits/libc-lock.h>
  26 #include <search.h>
  27 #include <stdio.h>
  28 #include <stdio_ext.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31
  32 #include <aliases.h>
  33 #include <grp.h>
  34 #include <netinet/ether.h>
  35 #include <pwd.h>
  36 #include <shadow.h>
  37
  38 #if !defined DO_STATIC_NSS || defined SHARED
  39 # include <gnu/lib-names.h>
  40 #endif
  41
  42 #include "nsswitch.h"
  43 #include "../nscd/nscd_proto.h"
  44 #include <sysdep.h>
  45
  46 /* Prototypes for the local functions.  */
  47 static name_database *nss_parse_file (const char *fname) internal_function;
  48 static name_database_entry *nss_getline (char *line) internal_function;
  49 static service_user *nss_parse_service_list (const char *line)
  50      internal_function;
  51 static service_library *nss_new_service (name_database *database,
  52                                          const char *name) internal_function;
  53
  54
  55 /* Declare external database variables.  */
  56 #define DEFINE_DATABASE(name)                                                 \
  57   extern 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 /* Flags whether custom rules for database is set.  */
  77 bool __nss_database_custom[NSS_DBSIDX_max];
  78
  79
  80 __libc_lock_define_initialized (static, lock)
  81
  82 #if !defined DO_STATIC_NSS || defined SHARED
  83 /* String with revision number of the shared object files.  */
  84 static const char *const __nss_shlib_revision = LIBNSS_FILES_SO + 15;
  85 #endif
  86
  87 /* The root of the whole data base.  */
  88 static name_database *service_table;
  89
  90
  91 /* Nonzero if this is the nscd process.  */
  92 static bool is_nscd;
  93 /* The callback passed to the init functions when nscd is used.  */
  94 static void (*nscd_init_cb) (size_t, struct traced_file *);
  95
  96
  97 /* -1 == database not found
  98     0 == database entry pointer stored */
  99 int
 100 __nss_database_lookup (const char *database, const char *alternate_name,
 101                        const char *defconfig, service_user **ni)
 102 {
 103   /* Prevent multiple threads to change the service table.  */
 104   __libc_lock_lock (lock);
 105
 106   /* Reconsider database variable in case some other thread called
 107      `__nss_configure_lookup' while we waited for the lock.  */
 108   if (*ni != NULL)
 109     {
 110       __libc_lock_unlock (lock);
 111       return 0;
 112     }
 113
 114   /* Are we initialized yet?  */
 115   if (service_table == NULL)
 116     /* Read config file.  */
 117     service_table = nss_parse_file (_PATH_NSSWITCH_CONF);
 118
 119   /* Test whether configuration data is available.  */
 120   if (service_table != NULL)
 121     {
 122       /* Return first `service_user' entry for DATABASE.  */
 123       name_database_entry *entry;
 124
 125       /* XXX Could use some faster mechanism here.  But each database is
 126          only requested once and so this might not be critical.  */
 127       for (entry = service_table->entry; entry != NULL; entry = entry->next)
 128         if (strcmp (database, entry->name) == 0)
 129           *ni = entry->service;
 130
 131       if (*ni == NULL && alternate_name != NULL)
 132         /* We haven't found an entry so far.  Try to find it with the
 133            alternative name.  */
 134         for (entry = service_table->entry; entry != NULL; entry = entry->next)
 135           if (strcmp (alternate_name, entry->name) == 0)
 136             *ni = entry->service;
 137     }
 138
 139   /* No configuration data is available, either because nsswitch.conf
 140      doesn't exist or because it doesn't have a line for this database.
 141
 142      DEFCONFIG specifies the default service list for this database,
 143      or null to use the most common default.  */
 144   if (*ni == NULL)
 145     *ni = nss_parse_service_list (defconfig
 146                                   ?: "nis [NOTFOUND=return] files");
 147
 148   __libc_lock_unlock (lock);
 149
 150   return 0;
 151 }
 152 libc_hidden_def (__nss_database_lookup)
 153
 154
 155 /* -1 == not found
 156     0 == function found
 157     1 == finished */
 158 int
 159 __nss_lookup (service_user **ni, const char *fct_name, const char *fct2_name,
 160               void **fctp)
 161 {
 162   *fctp = __nss_lookup_function (*ni, fct_name);
 163   if (*fctp == NULL && fct2_name != NULL)
 164     *fctp = __nss_lookup_function (*ni, fct2_name);
 165
 166   while (*fctp == NULL
 167          && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_CONTINUE
 168          && (*ni)->next != NULL)
 169     {
 170       *ni = (*ni)->next;
 171
 172       *fctp = __nss_lookup_function (*ni, fct_name);
 173       if (*fctp == NULL && fct2_name != NULL)
 174         *fctp = __nss_lookup_function (*ni, fct2_name);
 175     }
 176
 177   return *fctp != NULL ? 0 : (*ni)->next == NULL ? 1 : -1;
 178 }
 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 != &fct_name)
 388     {
 389       /* The search found an existing structure in the tree.  */
 390       result = ((known_function *) *found)->fct_ptr;
 391       PTR_DEMANGLE (result);
 392     }
 393   else
 394     {
 395       /* This name was not known before.  Now we have a node in the tree
 396          (in the proper sorted position for FCT_NAME) that points to
 397          &FCT_NAME instead of any real `known_function' structure.
 398          Allocate a new structure and fill it in.  */
 399
 400       known_function *known = malloc (sizeof *known);
 401       if (! known)
 402         {
 403         remove_from_tree:
 404           /* Oops.  We can't instantiate this node properly.
 405              Remove it from the tree.  */
 406           __tdelete (&fct_name, &ni->known, &known_compare);
 407           result = NULL;
 408         }
 409       else
 410         {
 411           /* Point the tree node at this new structure.  */
 412           *found = known;
 413           known->fct_name = fct_name;
 414
 415 #if !defined DO_STATIC_NSS || defined SHARED
 416           /* Load the appropriate library.  */
 417           if (nss_load_library (ni) != 0)
 418             {
 419               /* This only happens when out of memory.  */
 420               free (known);
 421               goto remove_from_tree;
 422             }
 423
 424           if (ni->library->lib_handle == (void *) -1l)
 425             /* Library not found => function not found.  */
 426             result = NULL;
 427           else
 428             {
 429               /* Get the desired function.  */
 430               size_t namlen = (5 + strlen (ni->library->name) + 1
 431                                + strlen (fct_name) + 1);
 432               char name[namlen];
 433
 434               /* Construct the function name.  */
 435               __stpcpy (__stpcpy (__stpcpy (__stpcpy (name, "_nss_"),
 436                                             ni->library->name),
 437                                   "_"),
 438                         fct_name);
 439
 440               /* Look up the symbol.  */
 441               result = __libc_dlsym (ni->library->lib_handle, name);
 442             }
 443 #else
 444           /* We can't get function address dynamically in static linking. */
 445           {
 446 # define DEFINE_ENT(h,nm)                                                     \
 447             { #h"_get"#nm"ent_r", _nss_##h##_get##nm##ent_r },                \
 448             { #h"_end"#nm"ent", _nss_##h##_end##nm##ent },                    \
 449             { #h"_set"#nm"ent", _nss_##h##_set##nm##ent },
 450 # define DEFINE_GET(h,nm)                                                     \
 451             { #h"_get"#nm"_r", _nss_##h##_get##nm##_r },
 452 # define DEFINE_GETBY(h,nm,ky)                                                \
 453             { #h"_get"#nm"by"#ky"_r", _nss_##h##_get##nm##by##ky##_r },
 454             static struct fct_tbl { const char *fname; void *fp; } *tp, tbl[] =
 455               {
 456 # include "function.def"
 457                 { NULL, NULL }
 458               };
 459             size_t namlen = (5 + strlen (ni->library->name) + 1
 460                              + strlen (fct_name) + 1);
 461             char name[namlen];
 462
 463             /* Construct the function name.  */
 464             __stpcpy (__stpcpy (__stpcpy (name, ni->library->name),
 465                                 "_"),
 466                       fct_name);
 467
 468             result = NULL;
 469             for (tp = &tbl[0]; tp->fname; tp++)
 470               if (strcmp (tp->fname, name) == 0)
 471                 {
 472                   result = tp->fp;
 473                   break;
 474                 }
 475           }
 476 #endif
 477
 478           /* Remember function pointer for later calls.  Even if null, we
 479              record it so a second try needn't search the library again.  */
 480           known->fct_ptr = result;
 481           PTR_MANGLE (known->fct_ptr);
 482         }
 483     }
 484
 485   /* Remove the lock.  */
 486   __libc_lock_unlock (lock);
 487
 488   return result;
 489 }
 490 libc_hidden_def (__nss_lookup_function)
 491
 492
 493 static name_database *
 494 internal_function
 495 nss_parse_file (const char *fname)
 496 {
 497   FILE *fp;
 498   name_database *result;
 499   name_database_entry *last;
 500   char *line;
 501   size_t len;
 502
 503   /* Open the configuration file.  */
 504   fp = fopen (fname, "rc");
 505   if (fp == NULL)
 506     return NULL;
 507
 508   /* No threads use this stream.  */
 509   __fsetlocking (fp, FSETLOCKING_BYCALLER);
 510
 511   result = (name_database *) malloc (sizeof (name_database));
 512   if (result == NULL)
 513     {
 514       fclose (fp);
 515       return NULL;
 516     }
 517
 518   result->entry = NULL;
 519   result->library = NULL;
 520   last = NULL;
 521   line = NULL;
 522   len = 0;
 523   do
 524     {
 525       name_database_entry *this;
 526       ssize_t n;
 527
 528       n = __getline (&line, &len, fp);
 529       if (n < 0)
 530         break;
 531       if (line[n - 1] == '\n')
 532         line[n - 1] = '\0';
 533
 534       /* Because the file format does not know any form of quoting we
 535          can search forward for the next '#' character and if found
 536          make it terminating the line.  */
 537       *__strchrnul (line, '#') = '\0';
 538
 539       /* If the line is blank it is ignored.  */
 540       if (line[0] == '\0')
 541         continue;
 542
 543       /* Each line completely specifies the actions for a database.  */
 544       this = nss_getline (line);
 545       if (this != NULL)
 546         {
 547           if (last != NULL)
 548             last->next = this;
 549           else
 550             result->entry = this;
 551
 552           last = this;
 553         }
 554     }
 555   while (!feof_unlocked (fp));
 556
 557   /* Free the buffer.  */
 558   free (line);
 559   /* Close configuration file.  */
 560   fclose (fp);
 561
 562   return result;
 563 }
 564
 565
 566 /* Read the source names:
 567         `( <source> ( "[" "!"? (<status> "=" <action> )+ "]" )? )*'
 568    */
 569 static service_user *
 570 internal_function
 571 nss_parse_service_list (const char *line)
 572 {
 573   service_user *result = NULL, **nextp = &result;
 574
 575   while (1)
 576     {
 577       service_user *new_service;
 578       const char *name;
 579
 580       while (isspace (line[0]))
 581         ++line;
 582       if (line[0] == '\0')
 583         /* No source specified.  */
 584         return result;
 585
 586       /* Read <source> identifier.  */
 587       name = line;
 588       while (line[0] != '\0' && !isspace (line[0]) && line[0] != '[')
 589         ++line;
 590       if (name == line)
 591         return result;
 592
 593
 594       new_service = (service_user *) malloc (sizeof (service_user)
 595                                              + (line - name + 1));
 596       if (new_service == NULL)
 597         return result;
 598
 599       *((char *) __mempcpy (new_service->name, name, line - name)) = '\0';
 600
 601       /* Set default actions.  */
 602       new_service->actions[2 + NSS_STATUS_TRYAGAIN] = NSS_ACTION_CONTINUE;
 603       new_service->actions[2 + NSS_STATUS_UNAVAIL] = NSS_ACTION_CONTINUE;
 604       new_service->actions[2 + NSS_STATUS_NOTFOUND] = NSS_ACTION_CONTINUE;
 605       new_service->actions[2 + NSS_STATUS_SUCCESS] = NSS_ACTION_RETURN;
 606       new_service->actions[2 + NSS_STATUS_RETURN] = NSS_ACTION_RETURN;
 607       new_service->library = NULL;
 608       new_service->known = NULL;
 609       new_service->next = NULL;
 610
 611       while (isspace (line[0]))
 612         ++line;
 613
 614       if (line[0] == '[')
 615         {
 616           /* Read criterions.  */
 617           do
 618             ++line;
 619           while (line[0] != '\0' && isspace (line[0]));
 620
 621           do
 622             {
 623               int not;
 624               enum nss_status status;
 625               lookup_actions action;
 626
 627               /* Grok ! before name to mean all statii but that one.  */
 628               not = line[0] == '!';
 629               if (not)
 630                 ++line;
 631
 632               /* Read status name.  */
 633               name = line;
 634               while (line[0] != '\0' && !isspace (line[0]) && line[0] != '='
 635                      && line[0] != ']')
 636                 ++line;
 637
 638               /* Compare with known statii.  */
 639               if (line - name == 7)
 640                 {
 641                   if (__strncasecmp (name, "SUCCESS", 7) == 0)
 642                     status = NSS_STATUS_SUCCESS;
 643                   else if (__strncasecmp (name, "UNAVAIL", 7) == 0)
 644                     status = NSS_STATUS_UNAVAIL;
 645                   else
 646                     return result;
 647                 }
 648               else if (line - name == 8)
 649                 {
 650                   if (__strncasecmp (name, "NOTFOUND", 8) == 0)
 651                     status = NSS_STATUS_NOTFOUND;
 652                   else if (__strncasecmp (name, "TRYAGAIN", 8) == 0)
 653                     status = NSS_STATUS_TRYAGAIN;
 654                   else
 655                     return result;
 656                 }
 657               else
 658                 return result;
 659
 660               while (isspace (line[0]))
 661                 ++line;
 662               if (line[0] != '=')
 663                 return result;
 664               do
 665                 ++line;
 666               while (isspace (line[0]));
 667
 668               name = line;
 669               while (line[0] != '\0' && !isspace (line[0]) && line[0] != '='
 670                      && line[0] != ']')
 671                 ++line;
 672
 673               if (line - name == 6 && __strncasecmp (name, "RETURN", 6) == 0)
 674                 action = NSS_ACTION_RETURN;
 675               else if (line - name == 8
 676                        && __strncasecmp (name, "CONTINUE", 8) == 0)
 677                 action = NSS_ACTION_CONTINUE;
 678               else
 679                 return result;
 680
 681               if (not)
 682                 {
 683                   /* Save the current action setting for this status,
 684                      set them all to the given action, and reset this one.  */
 685                   const lookup_actions save = new_service->actions[2 + status];
 686                   new_service->actions[2 + NSS_STATUS_TRYAGAIN] = action;
 687                   new_service->actions[2 + NSS_STATUS_UNAVAIL] = action;
 688                   new_service->actions[2 + NSS_STATUS_NOTFOUND] = action;
 689                   new_service->actions[2 + NSS_STATUS_SUCCESS] = action;
 690                   new_service->actions[2 + status] = save;
 691                 }
 692               else
 693                 new_service->actions[2 + status] = action;
 694
 695               /* Skip white spaces.  */
 696               while (isspace (line[0]))
 697                 ++line;
 698             }
 699           while (line[0] != ']');
 700
 701           /* Skip the ']'.  */
 702           ++line;
 703         }
 704
 705       *nextp = new_service;
 706       nextp = &new_service->next;
 707     }
 708 }
 709
 710 static name_database_entry *
 711 internal_function
 712 nss_getline (char *line)
 713 {
 714   const char *name;
 715   name_database_entry *result;
 716   size_t len;
 717
 718   /* Ignore leading white spaces.  ATTENTION: this is different from
 719      what is implemented in Solaris.  The Solaris man page says a line
 720      beginning with a white space character is ignored.  We regard
 721      this as just another misfeature in Solaris.  */
 722   while (isspace (line[0]))
 723     ++line;
 724
 725   /* Recognize `<database> ":"'.  */
 726   name = line;
 727   while (line[0] != '\0' && !isspace (line[0]) && line[0] != ':')
 728     ++line;
 729   if (line[0] == '\0' || name == line)
 730     /* Syntax error.  */
 731     return NULL;
 732   *line++ = '\0';
 733
 734   len = strlen (name) + 1;
 735
 736   result = (name_database_entry *) malloc (sizeof (name_database_entry) + len);
 737   if (result == NULL)
 738     return NULL;
 739
 740   /* Save the database name.  */
 741   memcpy (result->name, name, len);
 742
 743   /* Parse the list of services.  */
 744   result->service = nss_parse_service_list (line);
 745
 746   result->next = NULL;
 747   return result;
 748 }
 749
 750
 751 static service_library *
 752 internal_function
 753 nss_new_service (name_database *database, const char *name)
 754 {
 755   service_library **currentp = &database->library;
 756
 757   while (*currentp != NULL)
 758     {
 759       if (strcmp ((*currentp)->name, name) == 0)
 760         return *currentp;
 761       currentp = &(*currentp)->next;
 762     }
 763
 764   /* We have to add the new service.  */
 765   *currentp = (service_library *) malloc (sizeof (service_library));
 766   if (*currentp == NULL)
 767     return NULL;
 768
 769   (*currentp)->name = name;
 770   (*currentp)->lib_handle = NULL;
 771   (*currentp)->next = NULL;
 772
 773   return *currentp;
 774 }
 775
 776
 777 #ifdef SHARED
 778 /* Load all libraries for the service.  */
 779 static void
 780 nss_load_all_libraries (const char *service, const char *def)
 781 {
 782   service_user *ni = NULL;
 783
 784   if (__nss_database_lookup (service, NULL, def, &ni) == 0)
 785     while (ni != NULL)
 786       {
 787         nss_load_library (ni);
 788         ni = ni->next;
 789       }
 790 }
 791
 792
 793 /* Called by nscd and nscd alone.  */
 794 void
 795 __nss_disable_nscd (void (*cb) (size_t, struct traced_file *))
 796 {
 797 # ifdef PTR_MANGLE
 798   PTR_MANGLE (cb);
 799 # endif
 800   nscd_init_cb = cb;
 801   is_nscd = true;
 802
 803   /* Find all the relevant modules so that the init functions are called.  */
 804   nss_load_all_libraries ("passwd", "compat [NOTFOUND=return] files");
 805   nss_load_all_libraries ("group", "compat [NOTFOUND=return] files");
 806   nss_load_all_libraries ("hosts", "dns [!UNAVAIL=return] files");
 807   nss_load_all_libraries ("services", NULL);
 808
 809   /* Disable all uses of NSCD.  */
 810   __nss_not_use_nscd_passwd = -1;
 811   __nss_not_use_nscd_group = -1;
 812   __nss_not_use_nscd_hosts = -1;
 813   __nss_not_use_nscd_services = -1;
 814 }
 815 #endif
 816
 817
 818 /* Free all resources if necessary.  */
 819 libc_freeres_fn (free_mem)
 820 {
 821   name_database *top = service_table;
 822   name_database_entry *entry;
 823   service_library *library;
 824
 825   if (top == NULL)
 826     /* Maybe we have not read the nsswitch.conf file.  */
 827     return;
 828
 829   /* Don't disturb ongoing other threads (if there are any).  */
 830   service_table = NULL;
 831
 832   entry = top->entry;
 833   while (entry != NULL)
 834     {
 835       name_database_entry *olde = entry;
 836       service_user *service = entry->service;
 837
 838       while (service != NULL)
 839         {
 840           service_user *olds = service;
 841
 842           if (service->known != NULL)
 843             __tdestroy (service->known, free);
 844
 845           service = service->next;
 846           free (olds);
 847         }
 848
 849       entry = entry->next;
 850       free (olde);
 851     }
 852
 853   library = top->library;
 854   while (library != NULL)
 855     {
 856       service_library *oldl = library;
 857
 858       if (library->lib_handle && library->lib_handle != (void *) -1l)
 859         __libc_dlclose (library->lib_handle);
 860
 861       library = library->next;
 862       free (oldl);
 863     }
 864
 865   free (top);
 866 }