nss/nsswitch.c

   1 /* Copyright (C) 1996, 1997, 1998, 1999, 2001, 2002, 2003, 2004
   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
  45 /* Prototypes for the local functions.  */
  46 static name_database *nss_parse_file (const char *fname) internal_function;
  47 static name_database_entry *nss_getline (char *line) internal_function;
  48 static service_user *nss_parse_service_list (const char *line)
  49      internal_function;
  50 static service_library *nss_new_service (name_database *database,
  51                                          const char *name) internal_function;
  52
  53
  54 /* Declare external database variables.  */
  55 #define DEFINE_DATABASE(name)                                                 \
  56   extern service_user *__nss_##name##_database attribute_hidden;              \
  57   weak_extern (__nss_##name##_database)
  58 #include "databases.def"
  59 #undef DEFINE_DATABASE
  60
  61 /* Structure to map database name to variable.  */
  62 static struct
  63 {
  64   const char *name;
  65   service_user **dbp;
  66 } databases[] =
  67 {
  68 #define DEFINE_DATABASE(name)                                                 \
  69   { #name, &__nss_##name##_database },
  70 #include "databases.def"
  71 #undef DEFINE_DATABASE
  72 };
  73
  74
  75 __libc_lock_define_initialized (static, lock)
  76
  77 #if !defined DO_STATIC_NSS || defined SHARED
  78 /* String with revision number of the shared object files.  */
  79 static const char *const __nss_shlib_revision = LIBNSS_FILES_SO + 15;
  80 #endif
  81
  82 /* The root of the whole data base.  */
  83 static name_database *service_table;
  84
  85
  86 /* -1 == database not found
  87     0 == database entry pointer stored */
  88 int
  89 __nss_database_lookup (const char *database, const char *alternate_name,
  90                        const char *defconfig, service_user **ni)
  91 {
  92   /* Prevent multiple threads to change the service table.  */
  93   __libc_lock_lock (lock);
  94
  95   /* Reconsider database variable in case some other thread called
  96      `__nss_configure_lookup' while we waited for the lock.  */
  97   if (*ni != NULL)
  98     {
  99       __libc_lock_unlock (lock);
 100       return 0;
 101     }
 102
 103   /* Are we initialized yet?  */
 104   if (service_table == NULL)
 105     /* Read config file.  */
 106     service_table = nss_parse_file (_PATH_NSSWITCH_CONF);
 107
 108   /* Test whether configuration data is available.  */
 109   if (service_table != NULL)
 110     {
 111       /* Return first `service_user' entry for DATABASE.  */
 112       name_database_entry *entry;
 113
 114       /* XXX Could use some faster mechanism here.  But each database is
 115          only requested once and so this might not be critical.  */
 116       for (entry = service_table->entry; entry != NULL; entry = entry->next)
 117         if (strcmp (database, entry->name) == 0)
 118           *ni = entry->service;
 119
 120       if (*ni == NULL && alternate_name != NULL)
 121         /* We haven't found an entry so far.  Try to find it with the
 122            alternative name.  */
 123         for (entry = service_table->entry; entry != NULL; entry = entry->next)
 124           if (strcmp (alternate_name, entry->name) == 0)
 125             *ni = entry->service;
 126     }
 127
 128   /* No configuration data is available, either because nsswitch.conf
 129      doesn't exist or because it doesn't has a line for this database.
 130
 131      DEFCONFIG specifies the default service list for this database,
 132      or null to use the most common default.  */
 133   if (*ni == NULL)
 134     *ni = nss_parse_service_list (defconfig
 135                                   ?: "nis [NOTFOUND=return] files");
 136
 137   __libc_lock_unlock (lock);
 138
 139   return 0;
 140 }
 141 libc_hidden_def (__nss_database_lookup)
 142
 143
 144 /* -1 == not found
 145     0 == function found
 146     1 == finished */
 147 int
 148 __nss_lookup (service_user **ni, const char *fct_name, void **fctp)
 149 {
 150   *fctp = __nss_lookup_function (*ni, fct_name);
 151
 152   while (*fctp == NULL
 153          && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_CONTINUE
 154          && (*ni)->next != NULL)
 155     {
 156       *ni = (*ni)->next;
 157
 158       *fctp = __nss_lookup_function (*ni, fct_name);
 159     }
 160
 161   return *fctp != NULL ? 0 : (*ni)->next == NULL ? 1 : -1;
 162 }
 163
 164
 165 /* -1 == not found
 166     0 == adjusted for next function
 167     1 == finished */
 168 int
 169 __nss_next (service_user **ni, const char *fct_name, void **fctp, int status,
 170             int all_values)
 171 {
 172   if (all_values)
 173     {
 174       if (nss_next_action (*ni, NSS_STATUS_TRYAGAIN) == NSS_ACTION_RETURN
 175           && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_RETURN
 176           && nss_next_action (*ni, NSS_STATUS_NOTFOUND) == NSS_ACTION_RETURN
 177           && nss_next_action (*ni, NSS_STATUS_SUCCESS) == NSS_ACTION_RETURN)
 178         return 1;
 179     }
 180   else
 181     {
 182       /* This is really only for debugging.  */
 183        if (NSS_STATUS_TRYAGAIN > status || status > NSS_STATUS_RETURN)
 184          __libc_fatal ("illegal status in __nss_next");
 185
 186        if (nss_next_action (*ni, status) == NSS_ACTION_RETURN)
 187          return 1;
 188     }
 189
 190   if ((*ni)->next == NULL)
 191     return -1;
 192
 193   do
 194     {
 195       *ni = (*ni)->next;
 196
 197       *fctp = __nss_lookup_function (*ni, fct_name);
 198     }
 199   while (*fctp == NULL
 200          && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_CONTINUE
 201          && (*ni)->next != NULL);
 202
 203   return *fctp != NULL ? 0 : -1;
 204 }
 205 libc_hidden_def (__nss_next)
 206
 207
 208 int
 209 __nss_configure_lookup (const char *dbname, const char *service_line)
 210 {
 211   service_user *new_db;
 212   size_t cnt;
 213
 214   for (cnt = 0; cnt < sizeof databases; ++cnt)
 215     {
 216       int cmp = strcmp (dbname, databases[cnt].name);
 217       if (cmp == 0)
 218         break;
 219       if (cmp < 0)
 220         {
 221           __set_errno (EINVAL);
 222           return -1;
 223         }
 224     }
 225
 226   if (cnt == sizeof databases)
 227     {
 228       __set_errno (EINVAL);
 229       return -1;
 230     }
 231
 232   /* Test whether it is really used.  */
 233   if (databases[cnt].dbp == NULL)
 234     /* Nothing to do, but we could do.  */
 235     return 0;
 236
 237   /* Try to generate new data.  */
 238   new_db = nss_parse_service_list (service_line);
 239   if (new_db == NULL)
 240     {
 241       /* Illegal service specification.  */
 242       __set_errno (EINVAL);
 243       return -1;
 244     }
 245
 246   /* Prevent multiple threads to change the service table.  */
 247   __libc_lock_lock (lock);
 248
 249   /* Install new rules.  */
 250   *databases[cnt].dbp = new_db;
 251
 252   __libc_lock_unlock (lock);
 253
 254   return 0;
 255 }
 256
 257
 258 /* Comparison function for searching NI->known tree.  */
 259 static int
 260 known_compare (const void *p1, const void *p2)
 261 {
 262   return p1 == p2 ? 0 : strcmp (*(const char *const *) p1,
 263                                 *(const char *const *) p2);
 264 }
 265
 266
 267 void *
 268 __nss_lookup_function (service_user *ni, const char *fct_name)
 269 {
 270   void **found, *result;
 271
 272   /* We now modify global data.  Protect it.  */
 273   __libc_lock_lock (lock);
 274
 275   /* Search the tree of functions previously requested.  Data in the
 276      tree are `known_function' structures, whose first member is a
 277      `const char *', the lookup key.  The search returns a pointer to
 278      the tree node structure; the first member of the is a pointer to
 279      our structure (i.e. what will be a `known_function'); since the
 280      first member of that is the lookup key string, &FCT_NAME is close
 281      enough to a pointer to our structure to use as a lookup key that
 282      will be passed to `known_compare' (above).  */
 283
 284   found = __tsearch (&fct_name, (void **) &ni->known, &known_compare);
 285   if (*found != &fct_name)
 286     /* The search found an existing structure in the tree.  */
 287     result = ((known_function *) *found)->fct_ptr;
 288   else
 289     {
 290       /* This name was not known before.  Now we have a node in the tree
 291          (in the proper sorted position for FCT_NAME) that points to
 292          &FCT_NAME instead of any real `known_function' structure.
 293          Allocate a new structure and fill it in.  */
 294
 295       known_function *known = malloc (sizeof *known);
 296       if (! known)
 297         {
 298         remove_from_tree:
 299           /* Oops.  We can't instantiate this node properly.
 300              Remove it from the tree.  */
 301           __tdelete (&fct_name, (void **) &ni->known, &known_compare);
 302           result = NULL;
 303         }
 304       else
 305         {
 306           /* Point the tree node at this new structure.  */
 307           *found = known;
 308           known->fct_name = fct_name;
 309
 310           if (ni->library == NULL)
 311             {
 312               /* This service has not yet been used.  Fetch the service
 313                  library for it, creating a new one if need be.  If there
 314                  is no service table from the file, this static variable
 315                  holds the head of the service_library list made from the
 316                  default configuration.  */
 317               static name_database default_table;
 318               ni->library = nss_new_service (service_table ?: &default_table,
 319                                              ni->name);
 320               if (ni->library == NULL)
 321                 {
 322                   /* This only happens when out of memory.  */
 323                   free (known);
 324                   goto remove_from_tree;
 325                 }
 326             }
 327
 328 #if !defined DO_STATIC_NSS || defined SHARED
 329           if (ni->library->lib_handle == NULL)
 330             {
 331               /* Load the shared library.  */
 332               size_t shlen = (7 + strlen (ni->library->name) + 3
 333                               + strlen (__nss_shlib_revision) + 1);
 334               int saved_errno = errno;
 335               char shlib_name[shlen];
 336
 337               /* Construct shared object name.  */
 338               __stpcpy (__stpcpy (__stpcpy (__stpcpy (shlib_name,
 339                                                       "libnss_"),
 340                                             ni->library->name),
 341                                   ".so"),
 342                         __nss_shlib_revision);
 343
 344               ni->library->lib_handle = __libc_dlopen (shlib_name);
 345               if (ni->library->lib_handle == NULL)
 346                 {
 347                   /* Failed to load the library.  */
 348                   ni->library->lib_handle = (void *) -1l;
 349                   __set_errno (saved_errno);
 350                 }
 351             }
 352
 353           if (ni->library->lib_handle == (void *) -1l)
 354             /* Library not found => function not found.  */
 355             result = NULL;
 356           else
 357             {
 358               /* Get the desired function.  */
 359               size_t namlen = (5 + strlen (ni->library->name) + 1
 360                                + strlen (fct_name) + 1);
 361               char name[namlen];
 362
 363               /* Construct the function name.  */
 364               __stpcpy (__stpcpy (__stpcpy (__stpcpy (name, "_nss_"),
 365                                             ni->library->name),
 366                                   "_"),
 367                         fct_name);
 368
 369               /* Look up the symbol.  */
 370               result = __libc_dlsym (ni->library->lib_handle, name);
 371             }
 372 #else
 373           /* We can't get function address dynamically in static linking. */
 374           {
 375 # define DEFINE_ENT(h,nm)                                                     \
 376             { #h"_get"#nm"ent_r", _nss_##h##_get##nm##ent_r },                \
 377             { #h"_end"#nm"ent", _nss_##h##_end##nm##ent },                    \
 378             { #h"_set"#nm"ent", _nss_##h##_set##nm##ent },
 379 # define DEFINE_GET(h,nm)                                                     \
 380             { #h"_get"#nm"_r", _nss_##h##_get##nm##_r },
 381 # define DEFINE_GETBY(h,nm,ky)                                                \
 382             { #h"_get"#nm"by"#ky"_r", _nss_##h##_get##nm##by##ky##_r },
 383             static struct fct_tbl { const char *fname; void *fp; } *tp, tbl[] =
 384               {
 385 # include "function.def"
 386                 { NULL, NULL }
 387               };
 388             size_t namlen = (5 + strlen (ni->library->name) + 1
 389                              + strlen (fct_name) + 1);
 390             char name[namlen];
 391
 392             /* Construct the function name.  */
 393             __stpcpy (__stpcpy (__stpcpy (name, ni->library->name),
 394                                 "_"),
 395                       fct_name);
 396
 397             result = NULL;
 398             for (tp = &tbl[0]; tp->fname; tp++)
 399               if (strcmp (tp->fname, name) == 0)
 400                 {
 401                   result = tp->fp;
 402                   break;
 403                 }
 404           }
 405 #endif
 406
 407           /* Remember function pointer for later calls.  Even if null, we
 408              record it so a second try needn't search the library again.  */
 409           known->fct_ptr = result;
 410         }
 411     }
 412
 413   /* Remove the lock.  */
 414   __libc_lock_unlock (lock);
 415
 416   return result;
 417 }
 418 libc_hidden_def (__nss_lookup_function)
 419
 420
 421 static name_database *
 422 internal_function
 423 nss_parse_file (const char *fname)
 424 {
 425   FILE *fp;
 426   name_database *result;
 427   name_database_entry *last;
 428   char *line;
 429   size_t len;
 430
 431   /* Open the configuration file.  */
 432   fp = fopen (fname, "rc");
 433   if (fp == NULL)
 434     return NULL;
 435
 436   /* No threads use this stream.  */
 437   __fsetlocking (fp, FSETLOCKING_BYCALLER);
 438
 439   result = (name_database *) malloc (sizeof (name_database));
 440   if (result == NULL)
 441     return NULL;
 442
 443   result->entry = NULL;
 444   result->library = NULL;
 445   last = NULL;
 446   line = NULL;
 447   len = 0;
 448   do
 449     {
 450       name_database_entry *this;
 451       ssize_t n;
 452
 453       n = __getline (&line, &len, fp);
 454       if (n < 0)
 455         break;
 456       if (line[n - 1] == '\n')
 457         line[n - 1] = '\0';
 458
 459       /* Because the file format does not know any form of quoting we
 460          can search forward for the next '#' character and if found
 461          make it terminating the line.  */
 462       *__strchrnul (line, '#') = '\0';
 463
 464       /* If the line is blank it is ignored.  */
 465       if (line[0] == '\0')
 466         continue;
 467
 468       /* Each line completely specifies the actions for a database.  */
 469       this = nss_getline (line);
 470       if (this != NULL)
 471         {
 472           if (last != NULL)
 473             last->next = this;
 474           else
 475             result->entry = this;
 476
 477           last = this;
 478         }
 479     }
 480   while (!feof_unlocked (fp));
 481
 482   /* Free the buffer.  */
 483   free (line);
 484   /* Close configuration file.  */
 485   fclose (fp);
 486
 487   return result;
 488 }
 489
 490
 491 /* Read the source names:
 492         `( <source> ( "[" "!"? (<status> "=" <action> )+ "]" )? )*'
 493    */
 494 static service_user *
 495 internal_function
 496 nss_parse_service_list (const char *line)
 497 {
 498   service_user *result = NULL, **nextp = &result;
 499
 500   while (1)
 501     {
 502       service_user *new_service;
 503       const char *name;
 504
 505       while (isspace (line[0]))
 506         ++line;
 507       if (line[0] == '\0')
 508         /* No source specified.  */
 509         return result;
 510
 511       /* Read <source> identifier.  */
 512       name = line;
 513       while (line[0] != '\0' && !isspace (line[0]) && line[0] != '[')
 514         ++line;
 515       if (name == line)
 516         return result;
 517
 518
 519       new_service = (service_user *) malloc (sizeof (service_user)
 520                                              + (line - name + 1));
 521       if (new_service == NULL)
 522         return result;
 523
 524       *((char *) __mempcpy (new_service->name, name, line - name)) = '\0';
 525
 526       /* Set default actions.  */
 527       new_service->actions[2 + NSS_STATUS_TRYAGAIN] = NSS_ACTION_CONTINUE;
 528       new_service->actions[2 + NSS_STATUS_UNAVAIL] = NSS_ACTION_CONTINUE;
 529       new_service->actions[2 + NSS_STATUS_NOTFOUND] = NSS_ACTION_CONTINUE;
 530       new_service->actions[2 + NSS_STATUS_SUCCESS] = NSS_ACTION_RETURN;
 531       new_service->actions[2 + NSS_STATUS_RETURN] = NSS_ACTION_RETURN;
 532       new_service->library = NULL;
 533       new_service->known = NULL;
 534       new_service->next = NULL;
 535
 536       while (isspace (line[0]))
 537         ++line;
 538
 539       if (line[0] == '[')
 540         {
 541           /* Read criterions.  */
 542           do
 543             ++line;
 544           while (line[0] != '\0' && isspace (line[0]));
 545
 546           do
 547             {
 548               int not;
 549               enum nss_status status;
 550               lookup_actions action;
 551
 552               /* Grok ! before name to mean all statii but that one.  */
 553               not = line[0] == '!';
 554               if (not)
 555                 ++line;
 556
 557               /* Read status name.  */
 558               name = line;
 559               while (line[0] != '\0' && !isspace (line[0]) && line[0] != '='
 560                      && line[0] != ']')
 561                 ++line;
 562
 563               /* Compare with known statii.  */
 564               if (line - name == 7)
 565                 {
 566                   if (__strncasecmp (name, "SUCCESS", 7) == 0)
 567                     status = NSS_STATUS_SUCCESS;
 568                   else if (__strncasecmp (name, "UNAVAIL", 7) == 0)
 569                     status = NSS_STATUS_UNAVAIL;
 570                   else
 571                     return result;
 572                 }
 573               else if (line - name == 8)
 574                 {
 575                   if (__strncasecmp (name, "NOTFOUND", 8) == 0)
 576                     status = NSS_STATUS_NOTFOUND;
 577                   else if (__strncasecmp (name, "TRYAGAIN", 8) == 0)
 578                     status = NSS_STATUS_TRYAGAIN;
 579                   else
 580                     return result;
 581                 }
 582               else
 583                 return result;
 584
 585               while (isspace (line[0]))
 586                 ++line;
 587               if (line[0] != '=')
 588                 return result;
 589               do
 590                 ++line;
 591               while (isspace (line[0]));
 592
 593               name = line;
 594               while (line[0] != '\0' && !isspace (line[0]) && line[0] != '='
 595                      && line[0] != ']')
 596                 ++line;
 597
 598               if (line - name == 6 && __strncasecmp (name, "RETURN", 6) == 0)
 599                 action = NSS_ACTION_RETURN;
 600               else if (line - name == 8
 601                        && __strncasecmp (name, "CONTINUE", 8) == 0)
 602                 action = NSS_ACTION_CONTINUE;
 603               else
 604                 return result;
 605
 606               if (not)
 607                 {
 608                   /* Save the current action setting for this status,
 609                      set them all to the given action, and reset this one.  */
 610                   const lookup_actions save = new_service->actions[2 + status];
 611                   new_service->actions[2 + NSS_STATUS_TRYAGAIN] = action;
 612                   new_service->actions[2 + NSS_STATUS_UNAVAIL] = action;
 613                   new_service->actions[2 + NSS_STATUS_NOTFOUND] = action;
 614                   new_service->actions[2 + NSS_STATUS_SUCCESS] = action;
 615                   new_service->actions[2 + status] = save;
 616                 }
 617               else
 618                 new_service->actions[2 + status] = action;
 619
 620               /* Skip white spaces.  */
 621               while (isspace (line[0]))
 622                 ++line;
 623             }
 624           while (line[0] != ']');
 625
 626           /* Skip the ']'.  */
 627           ++line;
 628         }
 629
 630       *nextp = new_service;
 631       nextp = &new_service->next;
 632     }
 633 }
 634
 635 static name_database_entry *
 636 internal_function
 637 nss_getline (char *line)
 638 {
 639   const char *name;
 640   name_database_entry *result;
 641   size_t len;
 642
 643   /* Ignore leading white spaces.  ATTENTION: this is different from
 644      what is implemented in Solaris.  The Solaris man page says a line
 645      beginning with a white space character is ignored.  We regard
 646      this as just another misfeature in Solaris.  */
 647   while (isspace (line[0]))
 648     ++line;
 649
 650   /* Recognize `<database> ":"'.  */
 651   name = line;
 652   while (line[0] != '\0' && !isspace (line[0]) && line[0] != ':')
 653     ++line;
 654   if (line[0] == '\0' || name == line)
 655     /* Syntax error.  */
 656     return NULL;
 657   *line++ = '\0';
 658
 659   len = strlen (name) + 1;
 660
 661   result = (name_database_entry *) malloc (sizeof (name_database_entry) + len);
 662   if (result == NULL)
 663     return NULL;
 664
 665   /* Save the database name.  */
 666   memcpy (result->name, name, len);
 667
 668   /* Parse the list of services.  */
 669   result->service = nss_parse_service_list (line);
 670
 671   result->next = NULL;
 672   return result;
 673 }
 674
 675
 676 static service_library *
 677 internal_function
 678 nss_new_service (name_database *database, const char *name)
 679 {
 680   service_library **currentp = &database->library;
 681
 682   while (*currentp != NULL)
 683     {
 684       if (strcmp ((*currentp)->name, name) == 0)
 685         return *currentp;
 686       currentp = &(*currentp)->next;
 687     }
 688
 689   /* We have to add the new service.  */
 690   *currentp = (service_library *) malloc (sizeof (service_library));
 691   if (*currentp == NULL)
 692     return NULL;
 693
 694   (*currentp)->name = name;
 695   (*currentp)->lib_handle = NULL;
 696   (*currentp)->next = NULL;
 697
 698   return *currentp;
 699 }
 700
 701
 702 /* Called by nscd and nscd alone.  */
 703 void
 704 __nss_disable_nscd (void)
 705 {
 706   /* Disable all uses of NSCD.  */
 707   __nss_not_use_nscd_passwd = -1;
 708   __nss_not_use_nscd_group = -1;
 709   __nss_not_use_nscd_hosts = -1;
 710 }
 711
 712
 713 /* Free all resources if necessary.  */
 714 libc_freeres_fn (free_mem)
 715 {
 716   name_database *top = service_table;
 717   name_database_entry *entry;
 718   service_library *library;
 719
 720   if (top == NULL)
 721     /* Maybe we have not read the nsswitch.conf file.  */
 722     return;
 723
 724   /* Don't disturb ongoing other threads (if there are any).  */
 725   service_table = NULL;
 726
 727   entry = top->entry;
 728   while (entry != NULL)
 729     {
 730       name_database_entry *olde = entry;
 731       service_user *service = entry->service;
 732
 733       while (service != NULL)
 734         {
 735           service_user *olds = service;
 736
 737           if (service->known != NULL)
 738             __tdestroy (service->known, free);
 739
 740           service = service->next;
 741           free (olds);
 742         }
 743
 744       entry = entry->next;
 745       free (olde);
 746     }
 747
 748   library = top->library;
 749   while (library != NULL)
 750     {
 751       service_library *oldl = library;
 752
 753       if (library->lib_handle && library->lib_handle != (void *) -1l)
 754         __libc_dlclose (library->lib_handle);
 755
 756       library = library->next;
 757       free (oldl);
 758     }
 759
 760   free (top);
 761 }