nss/nsswitch.c

   1 /* Copyright (C) 1996, 1997, 1998 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 Library General Public License as
   7    published by the Free Software Foundation; either version 2 of the
   8    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    Library General Public License for more details.
  14
  15    You should have received a copy of the GNU Library General Public
  16    License along with the GNU C Library; see the file COPYING.LIB.  If not,
  17    write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18    Boston, MA 02111-1307, USA.  */
  19
  20 #include <ctype.h>
  21 #include <dlfcn.h>
  22 #include <errno.h>
  23 #include <netdb.h>
  24 #include <bits/libc-lock.h>
  25 #include <search.h>
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <string.h>
  29 #include <elf/ldsodefs.h>       /* We need some help from ld.so.  */
  30
  31 #if !defined DO_STATIC_NSS || defined PIC
  32 # include <gnu/lib-names.h>
  33 #endif
  34
  35 #include "nsswitch.h"
  36
  37 /* Prototypes for the local functions.  */
  38 static void *nss_lookup_function (service_user *ni, const char *fct_name)
  39      internal_function;
  40 static name_database *nss_parse_file (const char *fname) internal_function;
  41 static name_database_entry *nss_getline (char *line) internal_function;
  42 static service_user *nss_parse_service_list (const char *line)
  43      internal_function;
  44 static service_library *nss_new_service (name_database *database,
  45                                          const char *name) internal_function;
  46
  47
  48 /* Declare external database variables.  */
  49 #define DEFINE_DATABASE(name)                                                 \
  50   extern service_user *__nss_##name##_database;                               \
  51   weak_extern (__nss_##name##_database)
  52 #include "databases.def"
  53 #undef DEFINE_DATABASE
  54
  55 /* Structure to map database name to variable.  */
  56 static struct
  57 {
  58   const char *name;
  59   service_user **dbp;
  60 } databases[] =
  61 {
  62 #define DEFINE_DATABASE(name)                                                 \
  63   { #name, &__nss_##name##_database },
  64 #include "databases.def"
  65 #undef DEFINE_DATABASE
  66 };
  67
  68
  69 __libc_lock_define_initialized (static, lock)
  70
  71 #if !defined DO_STATIC_NSS || defined PIC
  72 /* String with revision number of the shared object files.  */
  73 static const char *const __nss_shlib_revision = LIBNSS_FILES_SO + 15;
  74 #endif
  75
  76 /* The root of the whole data base.  */
  77 static name_database *service_table;
  78
  79
  80 /* -1 == database not found
  81     0 == database entry pointer stored */
  82 int
  83 __nss_database_lookup (const char *database, const char *alternate_name,
  84                        const char *defconfig, service_user **ni)
  85 {
  86   /* Prevent multiple threads to change the service table.  */
  87   __libc_lock_lock (lock);
  88
  89   /* Reconsider database variable in case some other thread called
  90      `__nss_configure_lookup' while we waited for the lock.  */
  91   if (*ni != NULL)
  92     {
  93       __libc_lock_unlock (lock);
  94       return 0;
  95     }
  96
  97   /* Are we initialized yet?  */
  98   if (service_table == NULL)
  99     /* Read config file.  */
 100     service_table = nss_parse_file (_PATH_NSSWITCH_CONF);
 101
 102   /* Test whether configuration data is available.  */
 103   if (service_table != NULL)
 104     {
 105       /* Return first `service_user' entry for DATABASE.  */
 106       name_database_entry *entry;
 107
 108       /* XXX Could use some faster mechanism here.  But each database is
 109          only requested once and so this might not be critical.  */
 110       for (entry = service_table->entry; entry != NULL; entry = entry->next)
 111         if (strcmp (database, entry->name) == 0)
 112           *ni = entry->service;
 113
 114       if (*ni == NULL && alternate_name != NULL)
 115         /* We haven't found an entry so far.  Try to find it with the
 116            alternative name.  */
 117         for (entry = service_table->entry; entry != NULL; entry = entry->next)
 118           if (strcmp (alternate_name, entry->name) == 0)
 119             *ni = entry->service;
 120     }
 121
 122   /* No configuration data is available, either because nsswitch.conf
 123      doesn't exist or because it doesn't has a line for this database.
 124
 125      DEFCONFIG specifies the default service list for this database,
 126      or null to use the most common default.  */
 127   if (*ni == NULL)
 128     *ni = nss_parse_service_list (defconfig
 129                                   ?: "nis [NOTFOUND=return] files");
 130
 131   __libc_lock_unlock (lock);
 132
 133   return 0;
 134 }
 135
 136
 137 /* -1 == not found
 138     0 == function found
 139     1 == finished */
 140 int
 141 __nss_lookup (service_user **ni, const char *fct_name, void **fctp)
 142 {
 143   *fctp = nss_lookup_function (*ni, fct_name);
 144
 145   while (*fctp == NULL
 146          && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_CONTINUE
 147          && (*ni)->next != NULL)
 148     {
 149       *ni = (*ni)->next;
 150
 151       *fctp = nss_lookup_function (*ni, fct_name);
 152     }
 153
 154   return *fctp != NULL ? 0 : (*ni)->next == NULL ? 1 : -1;
 155 }
 156
 157
 158 /* -1 == not found
 159     0 == adjusted for next function
 160     1 == finished */
 161 int
 162 __nss_next (service_user **ni, const char *fct_name, void **fctp, int status,
 163             int all_values)
 164 {
 165   if (all_values)
 166     {
 167       if (nss_next_action (*ni, NSS_STATUS_TRYAGAIN) == NSS_ACTION_RETURN
 168           && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_RETURN
 169           && nss_next_action (*ni, NSS_STATUS_NOTFOUND) == NSS_ACTION_RETURN
 170           && nss_next_action (*ni, NSS_STATUS_SUCCESS) == NSS_ACTION_RETURN)
 171         return 1;
 172     }
 173   else
 174     {
 175       /* This is really only for debugging.  */
 176        if (NSS_STATUS_TRYAGAIN > status || status > NSS_STATUS_RETURN)
 177          __libc_fatal ("illegal status in " __FUNCTION__);
 178
 179        if (nss_next_action (*ni, status) == NSS_ACTION_RETURN)
 180          return 1;
 181     }
 182
 183   if ((*ni)->next == NULL)
 184     return -1;
 185
 186   do
 187     {
 188       *ni = (*ni)->next;
 189
 190       *fctp = nss_lookup_function (*ni, fct_name);
 191     }
 192   while (*fctp == NULL
 193          && nss_next_action (*ni, NSS_STATUS_UNAVAIL) == NSS_ACTION_CONTINUE
 194          && (*ni)->next != NULL);
 195
 196   return *fctp != NULL ? 0 : -1;
 197 }
 198
 199
 200 int
 201 __nss_configure_lookup (const char *dbname, const char *service_line)
 202 {
 203   service_user *new_db;
 204   size_t cnt;
 205
 206   for (cnt = 0; cnt < sizeof databases; ++cnt)
 207     {
 208       int cmp = strcmp (dbname, databases[cnt].name);
 209       if (cmp == 0)
 210         break;
 211       if (cmp < 0)
 212         {
 213           __set_errno (EINVAL);
 214           return -1;
 215         }
 216     }
 217
 218   if (cnt == sizeof databases)
 219     {
 220       __set_errno (EINVAL);
 221       return -1;
 222     }
 223
 224   /* Test whether it is really used.  */
 225   if (databases[cnt].dbp == NULL)
 226     /* Nothing to do, but we could do.  */
 227     return 0;
 228
 229   /* Try to generate new data.  */
 230   new_db = nss_parse_service_list (service_line);
 231   if (new_db == NULL)
 232     {
 233       /* Illegal service specification.  */
 234       __set_errno (EINVAL);
 235       return -1;
 236     }
 237
 238   /* Prevent multiple threads to change the service table.  */
 239   __libc_lock_lock (lock);
 240
 241   /* Install new rules.  */
 242   *databases[cnt].dbp = new_db;
 243
 244   __libc_lock_unlock (lock);
 245
 246   return 0;
 247 }
 248
 249
 250 #if !defined DO_STATIC_NSS || defined PIC
 251 static int
 252 nss_dlerror_run (void (*operate) (void *), void *args)
 253 {
 254   char *last_errstring = NULL;
 255   int result;
 256
 257   (void) _dl_catch_error (&last_errstring, operate, args);
 258
 259   result = last_errstring != NULL;
 260   if (result)
 261     free (last_errstring);
 262
 263   return result;
 264 }
 265
 266
 267 struct do_open_args
 268 {
 269   /* Argument to do_open.  */
 270   char *shlib_name;
 271   service_user *ni;
 272 };
 273
 274 struct get_sym_args
 275 {
 276   /* Arguments to get_sym.  */
 277   struct link_map *map;
 278   char *name;
 279
 280   /* Return values of get_sym.  */
 281   ElfW(Addr) loadbase;
 282   const ElfW(Sym) *ref;
 283 };
 284
 285 static void
 286 do_open (void *a)
 287 {
 288   struct do_open_args *args = (struct do_open_args *) a;
 289   /* Open and relocate the shared object.  */
 290   args->ni->library->lib_handle = _dl_open (args->shlib_name, RTLD_LAZY);
 291 }
 292
 293 static void
 294 get_sym (void *a)
 295 {
 296   struct get_sym_args *args = (struct get_sym_args *) a;
 297   struct link_map *scope[2] = { args->map, NULL };
 298   args->ref = NULL;
 299   args->loadbase = _dl_lookup_symbol (args->name, &args->ref,
 300                                       scope, args->map->l_name, 0);
 301 }
 302 #endif
 303
 304 /* Comparison function for searching NI->known tree.  */
 305 static int
 306 known_compare (const void *p1, const void *p2)
 307 {
 308   return p1 == p2 ? 0 : strcmp (*(const char *const *) p1,
 309                                 *(const char *const *) p2);
 310 }
 311
 312
 313 static void *
 314 internal_function
 315 nss_lookup_function (service_user *ni, const char *fct_name)
 316 {
 317   void **found, *result;
 318
 319   /* We now modify global data.  Protect it.  */
 320   __libc_lock_lock (lock);
 321
 322   /* Search the tree of functions previously requested.  Data in the
 323      tree are `known_function' structures, whose first member is a
 324      `const char *', the lookup key.  The search returns a pointer to
 325      the tree node structure; the first member of the is a pointer to
 326      our structure (i.e. what will be a `known_function'); since the
 327      first member of that is the lookup key string, &FCT_NAME is close
 328      enough to a pointer to our structure to use as a lookup key that
 329      will be passed to `known_compare' (above).  */
 330
 331   found = __tsearch (&fct_name, (void **) &ni->known, &known_compare);
 332   if (*found != &fct_name)
 333     /* The search found an existing structure in the tree.  */
 334     result = ((known_function *) *found)->fct_ptr;
 335   else
 336     {
 337       /* This name was not known before.  Now we have a node in the tree
 338          (in the proper sorted position for FCT_NAME) that points to
 339          &FCT_NAME instead of any real `known_function' structure.
 340          Allocate a new structure and fill it in.  */
 341
 342       known_function *known = malloc (sizeof *known);
 343       if (! known)
 344         {
 345         remove_from_tree:
 346           /* Oops.  We can't instantiate this node properly.
 347              Remove it from the tree.  */
 348           __tdelete (&fct_name, (void **) &ni->known, &known_compare);
 349           result = NULL;
 350         }
 351       else
 352         {
 353           /* Point the tree node at this new structure.  */
 354           *found = known;
 355           known->fct_name = fct_name;
 356
 357           if (ni->library == NULL)
 358             {
 359               /* This service has not yet been used.  Fetch the service
 360                  library for it, creating a new one if need be.  If there
 361                  is no service table from the file, this static variable
 362                  holds the head of the service_library list made from the
 363                  default configuration.  */
 364               static name_database default_table;
 365               ni->library = nss_new_service (service_table ?: &default_table,
 366                                              ni->name);
 367               if (ni->library == NULL)
 368                 {
 369                   /* This only happens when out of memory.  */
 370                   free (known);
 371                   goto remove_from_tree;
 372                 }
 373             }
 374
 375 #if !defined DO_STATIC_NSS || defined PIC
 376           if (ni->library->lib_handle == NULL)
 377             {
 378               /* Load the shared library.  */
 379               size_t shlen = (7 + strlen (ni->library->name) + 3
 380                               + strlen (__nss_shlib_revision) + 1);
 381               int saved_errno = errno;
 382               struct do_open_args args;
 383               args.shlib_name = __alloca (shlen);
 384               args.ni = ni;
 385
 386               /* Construct shared object name.  */
 387               __stpcpy (__stpcpy (__stpcpy (__stpcpy (args.shlib_name,
 388                                                       "libnss_"),
 389                                             ni->library->name),
 390                                   ".so"),
 391                         __nss_shlib_revision);
 392
 393               if (nss_dlerror_run (do_open, &args) != 0)
 394                 {
 395                   /* Failed to load the library.  */
 396                   ni->library->lib_handle = (void *) -1l;
 397                   __set_errno (saved_errno);
 398                 }
 399             }
 400
 401           if (ni->library->lib_handle == (void *) -1l)
 402             /* Library not found => function not found.  */
 403             result = NULL;
 404           else
 405             {
 406               /* Get the desired function.  Again,  GNU ld.so magic ahead.  */
 407               size_t namlen = (5 + strlen (ni->library->name) + 1
 408                                + strlen (fct_name) + 1);
 409               struct get_sym_args args;
 410               args.name = __alloca (namlen);
 411               args.map = ni->library->lib_handle;
 412
 413               /* Construct the function name.  */
 414               __stpcpy (__stpcpy (__stpcpy (__stpcpy (args.name, "_nss_"),
 415                                             ni->library->name),
 416                                   "_"),
 417                         fct_name);
 418
 419               /* Look up the symbol.  */
 420               result = (nss_dlerror_run (get_sym, &args) ? NULL
 421                         : (void *) (args.loadbase + args.ref->st_value));
 422             }
 423 #else
 424           /* We can't get function address dynamically in static linking. */
 425           {
 426 # define DEFINE_ENT(h,nm)                                                     \
 427             extern void _nss_##h##_get##nm##ent_r (void);                     \
 428             extern void _nss_##h##_end##nm##ent (void);                       \
 429             extern void _nss_##h##_set##nm##ent (void);
 430 # define DEFINE_GET(h,nm)                                                     \
 431             extern void _nss_##h##_get##nm##_r (void);
 432 # define DEFINE_GETBY(h,nm,ky)                                                \
 433             extern void _nss_##h##_get##nm##by##ky##_r (void);
 434 # include "function.def"
 435 # undef DEFINE_ENT
 436 # undef DEFINE_GET
 437 # undef DEFINE_GETBY
 438 # define DEFINE_ENT(h,nm)                                                     \
 439             { #h"_get"#nm"ent_r", _nss_##h##_get##nm##ent_r },                \
 440             { #h"_end"#nm"ent", _nss_##h##_end##nm##ent },                    \
 441             { #h"_set"#nm"ent", _nss_##h##_set##nm##ent },
 442 # define DEFINE_GET(h,nm)                                                     \
 443             { #h"_get"#nm"_r", _nss_##h##_get##nm##_r },
 444 # define DEFINE_GETBY(h,nm,ky)                                                \
 445             { #h"_get"#nm"by"#ky"_r", _nss_##h##_get##nm##by##ky##_r },
 446             static struct fct_tbl { const char *fname; void *fp; } *tp, tbl[] =
 447               {
 448 # include "function.def"
 449                 { NULL, NULL }
 450               };
 451             size_t namlen = (5 + strlen (ni->library->name) + 1
 452                              + strlen (fct_name) + 1);
 453             char name[namlen];
 454
 455             /* Construct the function name.  */
 456             __stpcpy (__stpcpy (__stpcpy (name, ni->library->name),
 457                                 "_"),
 458                       fct_name);
 459
 460             result = NULL;
 461             for (tp = &tbl[0]; tp->fname; tp++)
 462               if (strcmp (tp->fname, name) == 0)
 463                 {
 464                   result = tp->fp;
 465                   break;
 466                 }
 467           }
 468 #endif
 469
 470           /* Remember function pointer for later calls.  Even if null, we
 471              record it so a second try needn't search the library again.  */
 472           known->fct_ptr = result;
 473         }
 474     }
 475
 476   /* Remove the lock.  */
 477   __libc_lock_unlock (lock);
 478
 479   return result;
 480 }
 481
 482
 483 static name_database *
 484 internal_function
 485 nss_parse_file (const char *fname)
 486 {
 487   FILE *fp;
 488   name_database *result;
 489   name_database_entry *last;
 490   char *line;
 491   size_t len;
 492
 493   /* Open the configuration file.  */
 494   fp = fopen (fname, "r");
 495   if (fp == NULL)
 496     return NULL;
 497
 498   result = (name_database *) malloc (sizeof (name_database));
 499   if (result == NULL)
 500     return NULL;
 501
 502   result->entry = NULL;
 503   result->library = NULL;
 504   last = NULL;
 505   line = NULL;
 506   len = 0;
 507   do
 508     {
 509       name_database_entry *this;
 510       ssize_t n;
 511       char *cp;
 512
 513       n = __getline (&line, &len, fp);
 514       if (n < 0)
 515         break;
 516       if (line[n - 1] == '\n')
 517         line[n - 1] = '\0';
 518
 519       /* Because the file format does not know any form of quoting we
 520          can search forward for the next '#' character and if found
 521          make it terminating the line.  */
 522       cp = strchr (line, '#');
 523       if (cp != NULL)
 524         *cp = '\0';
 525
 526       /* If the line is blank it is ignored.  */
 527       if (line[0] == '\0')
 528         continue;
 529
 530       /* Each line completely specifies the actions for a database.  */
 531       this = nss_getline (line);
 532       if (this != NULL)
 533         {
 534           if (last != NULL)
 535             last->next = this;
 536           else
 537             result->entry = this;
 538
 539           last = this;
 540         }
 541     }
 542   while (!feof (fp));
 543
 544   /* Free the buffer.  */
 545   free (line);
 546   /* Close configuration file.  */
 547   fclose (fp);
 548
 549   return result;
 550 }
 551
 552
 553 /* Read the source names:
 554         `( <source> ( "[" "!"? (<status> "=" <action> )+ "]" )? )*'
 555    */
 556 static service_user *
 557 internal_function
 558 nss_parse_service_list (const char *line)
 559 {
 560   service_user *result = NULL, **nextp = &result;
 561
 562   while (1)
 563     {
 564       service_user *new_service;
 565       const char *name;
 566
 567       while (isspace (line[0]))
 568         ++line;
 569       if (line[0] == '\0')
 570         /* No source specified.  */
 571         return result;
 572
 573       /* Read <source> identifier.  */
 574       name = line;
 575       while (line[0] != '\0' && !isspace (line[0]) && line[0] != '[')
 576         ++line;
 577       if (name == line)
 578         return result;
 579
 580
 581       new_service = (service_user *) malloc (sizeof (service_user));
 582       if (new_service == NULL)
 583         return result;
 584       else
 585         {
 586           char *source = (char *) malloc (line - name + 1);
 587           if (source == NULL)
 588             {
 589               free (new_service);
 590               return result;
 591             }
 592           *((char *) __mempcpy (source, name, line - name)) = '\0';
 593
 594           new_service->name = source;
 595         }
 596
 597       /* Set default actions.  */
 598       new_service->actions[2 + NSS_STATUS_TRYAGAIN] = NSS_ACTION_CONTINUE;
 599       new_service->actions[2 + NSS_STATUS_UNAVAIL] = NSS_ACTION_CONTINUE;
 600       new_service->actions[2 + NSS_STATUS_NOTFOUND] = NSS_ACTION_CONTINUE;
 601       new_service->actions[2 + NSS_STATUS_SUCCESS] = NSS_ACTION_RETURN;
 602       new_service->actions[2 + NSS_STATUS_RETURN] = NSS_ACTION_RETURN;
 603       new_service->library = NULL;
 604       new_service->known = NULL;
 605       new_service->next = NULL;
 606
 607       while (isspace (line[0]))
 608         ++line;
 609
 610       if (line[0] == '[')
 611         {
 612           /* Read criterions.  */
 613           do
 614             ++line;
 615           while (line[0] != '\0' && isspace (line[0]));
 616
 617           do
 618             {
 619               int not;
 620               enum nss_status status;
 621               lookup_actions action;
 622
 623               /* Grok ! before name to mean all statii but that one.  */
 624               if (not = line[0] == '!')
 625                 ++line;
 626
 627               /* Read status name.  */
 628               name = line;
 629               while (line[0] != '\0' && !isspace (line[0]) && line[0] != '='
 630                      && line[0] != ']')
 631                 ++line;
 632
 633               /* Compare with known statii.  */
 634               if (line - name == 7)
 635                 {
 636                   if (__strncasecmp (name, "SUCCESS", 7) == 0)
 637                     status = NSS_STATUS_SUCCESS;
 638                   else if (__strncasecmp (name, "UNAVAIL", 7) == 0)
 639                     status = NSS_STATUS_UNAVAIL;
 640                   else
 641                     return result;
 642                 }
 643               else if (line - name == 8)
 644                 {
 645                   if (__strncasecmp (name, "NOTFOUND", 8) == 0)
 646                     status = NSS_STATUS_NOTFOUND;
 647                   else if (__strncasecmp (name, "TRYAGAIN", 8) == 0)
 648                     status = NSS_STATUS_TRYAGAIN;
 649                   else
 650                     return result;
 651                 }
 652               else
 653                 return result;
 654
 655               while (isspace (line[0]))
 656                 ++line;
 657               if (line[0] != '=')
 658                 return result;
 659               do
 660                 ++line;
 661               while (isspace (line[0]));
 662
 663               name = line;
 664               while (line[0] != '\0' && !isspace (line[0]) && line[0] != '='
 665                      && line[0] != ']')
 666                 ++line;
 667
 668               if (line - name == 6 && __strncasecmp (name, "RETURN", 6) == 0)
 669                 action = NSS_ACTION_RETURN;
 670               else if (line - name == 8
 671                        && __strncasecmp (name, "CONTINUE", 8) == 0)
 672                 action = NSS_ACTION_CONTINUE;
 673               else
 674                 return result;
 675
 676               if (not)
 677                 {
 678                   /* Save the current action setting for this status,
 679                      set them all to the given action, and reset this one.  */
 680                   const lookup_actions save = new_service->actions[2 + status];
 681                   new_service->actions[2 + NSS_STATUS_TRYAGAIN] = action;
 682                   new_service->actions[2 + NSS_STATUS_UNAVAIL] = action;
 683                   new_service->actions[2 + NSS_STATUS_NOTFOUND] = action;
 684                   new_service->actions[2 + NSS_STATUS_SUCCESS] = action;
 685                   new_service->actions[2 + status] = save;
 686                 }
 687               else
 688                 new_service->actions[2 + status] = action;
 689
 690               /* Skip white spaces.  */
 691               while (isspace (line[0]))
 692                 ++line;
 693             }
 694           while (line[0] != ']');
 695
 696           /* Skip the ']'.  */
 697           ++line;
 698         }
 699
 700       *nextp = new_service;
 701       nextp = &new_service->next;
 702     }
 703 }
 704
 705 static name_database_entry *
 706 internal_function
 707 nss_getline (char *line)
 708 {
 709   const char *name;
 710   name_database_entry *result;
 711
 712   /* Ignore leading white spaces.  ATTENTION: this is different from
 713      what is implemented in Solaris.  The Solaris man page says a line
 714      beginning with a white space character is ignored.  We regard
 715      this as just another misfeature in Solaris.  */
 716   while (isspace (line[0]))
 717     ++line;
 718
 719   /* Recognize `<database> ":"'.  */
 720   name = line;
 721   while (line[0] != '\0' && !isspace (line[0]) && line[0] != ':')
 722     ++line;
 723   if (line[0] == '\0' || name == line)
 724     /* Syntax error.  */
 725     return NULL;
 726   *line++ = '\0';
 727
 728   result = (name_database_entry *) malloc (sizeof (name_database_entry));
 729   if (result == NULL)
 730     return NULL;
 731
 732   /* Save the database name.  */
 733   {
 734     const size_t len = strlen (name) + 1;
 735     char *new = malloc (len);
 736     if (new == NULL)
 737       {
 738         free (result);
 739         return NULL;
 740       }
 741     result->name = memcpy (new, name, len);
 742   }
 743
 744   /* Parse the list of services.  */
 745   result->service = nss_parse_service_list (line);
 746
 747   result->next = NULL;
 748   return result;
 749 }
 750
 751
 752 static service_library *
 753 internal_function
 754 nss_new_service (name_database *database, const char *name)
 755 {
 756   service_library **currentp = &database->library;
 757
 758   while (*currentp != NULL)
 759     {
 760       if (strcmp ((*currentp)->name, name) == 0)
 761         return *currentp;
 762       currentp = &(*currentp)->next;
 763     }
 764
 765   /* We have to add the new service.  */
 766   *currentp = (service_library *) malloc (sizeof (service_library));
 767   if (*currentp == NULL)
 768     return NULL;
 769
 770   (*currentp)->name = name;
 771   (*currentp)->lib_handle = NULL;
 772   (*currentp)->next = NULL;
 773
 774   return *currentp;
 775 }