nss/nsswitch.c

   1 /* Copyright (C) 1996, 1997 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 <link.h>       /* We need some help from ld.so.  */
  26 #include <search.h>
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  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
  72 #if !defined DO_STATIC_NSS || defined PIC
  73 /* String with revision number of the shared object files.  */
  74 static const char *const __nss_shlib_revision = LIBNSS_FILES_SO + 15;
  75 #endif
  76
  77 /* The root of the whole data base.  */
  78 static name_database *service_table;
  79
  80
  81 /* -1 == database not found
  82     0 == database entry pointer stored */
  83 int
  84 __nss_database_lookup (const char *database, const char *alternate_name,
  85                        const char *defconfig, service_user **ni)
  86 {
  87   /* Prevent multiple threads to change the service table.  */
  88   __libc_lock_lock (lock);
  89
  90   /* Reconsider database variable in case some other thread called
  91      `__nss_configure_lookup' while we waited for the lock.  */
  92   if (*ni != NULL)
  93     {
  94       __libc_lock_unlock (lock);
  95       return 0;
  96     }
  97
  98   /* Are we initialized yet?  */
  99   if (service_table == NULL)
 100     /* Read config file.  */
 101     service_table = nss_parse_file (_PATH_NSSWITCH_CONF);
 102
 103   /* Test whether configuration data is available.  */
 104   if (service_table != NULL)
 105     {
 106       /* Return first `service_user' entry for DATABASE.  */
 107       name_database_entry *entry;
 108
 109       /* XXX Could use some faster mechanism here.  But each database is
 110          only requested once and so this might not be critical.  */
 111       for (entry = service_table->entry; entry != NULL; entry = entry->next)
 112         if (strcmp (database, entry->name) == 0)
 113           *ni = entry->service;
 114
 115       if (*ni == NULL && alternate_name != NULL)
 116         /* We haven't found an entry so far.  Try to find it with the
 117            alternative name.  */
 118         for (entry = service_table->entry; entry != NULL; entry = entry->next)
 119           if (strcmp (alternate_name, entry->name) == 0)
 120             *ni = entry->service;
 121     }
 122
 123   /* No configuration data is available, either because nsswitch.conf
 124      doesn't exist or because it doesn't has a line for this database.
 125
 126      DEFCONFIG specifies the default service list for this database,
 127      or null to use the most common default.  */
 128   if (*ni == NULL)
 129     *ni = nss_parse_service_list (defconfig
 130                                   ?: "nis [NOTFOUND=return] files");
 131
 132   __libc_lock_unlock (lock);
 133
 134   return 0;
 135 }
 136
 137
 138 /* -1 == not found
 139     0 == adjusted for next function */
 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 : -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   const char *last_object_name = NULL;
 256   int result;
 257
 258   (void) _dl_catch_error (&last_errstring, &last_object_name, operate, args);
 259
 260   result = last_errstring != NULL;
 261   if (result)
 262     free (last_errstring);
 263
 264   return result;
 265 }
 266
 267
 268 struct do_open_args
 269 {
 270   /* Argument to do_open.  */
 271   char *shlib_name;
 272   service_user *ni;
 273 };
 274
 275 struct get_sym_args
 276 {
 277   /* Arguments to get_sym.  */
 278   struct link_map *map;
 279   char *name;
 280
 281   /* Return values of get_sym.  */
 282   ElfW(Addr) loadbase;
 283   const ElfW(Sym) *ref;
 284 };
 285
 286 static void
 287 do_open (void *a)
 288 {
 289   struct do_open_args *args = (struct do_open_args *) a;
 290   /* Open and relocate the shared object.  */
 291   args->ni->library->lib_handle = _dl_open (args->shlib_name, RTLD_LAZY);
 292 }
 293
 294 static void
 295 get_sym (void *a)
 296 {
 297   struct get_sym_args *args = (struct get_sym_args *) a;
 298   struct link_map *scope[2] = { args->map, NULL };
 299   args->ref = NULL;
 300   args->loadbase = _dl_lookup_symbol (args->name, &args->ref,
 301                                       scope, args->map->l_name, 0);
 302 }
 303 #endif
 304
 305 /* Comparison function for searching NI->known tree.  */
 306 static int
 307 known_compare (const void *p1, const void *p2)
 308 {
 309   return p1 == p2 ? 0 : strcmp (*(const char *const *) p1,
 310                                 *(const char *const *) p2);
 311 }
 312
 313
 314 static void *
 315 internal_function
 316 nss_lookup_function (service_user *ni, const char *fct_name)
 317 {
 318   void **found, *result;
 319
 320   /* We now modify global data.  Protect it.  */
 321   __libc_lock_lock (lock);
 322
 323   /* Search the tree of functions previously requested.  Data in the
 324      tree are `known_function' structures, whose first member is a
 325      `const char *', the lookup key.  The search returns a pointer to
 326      the tree node structure; the first member of the is a pointer to
 327      our structure (i.e. what will be a `known_function'); since the
 328      first member of that is the lookup key string, &FCT_NAME is close
 329      enough to a pointer to our structure to use as a lookup key that
 330      will be passed to `known_compare' (above).  */
 331
 332   found = __tsearch (&fct_name, (void **) &ni->known, &known_compare);
 333   if (*found != &fct_name)
 334     /* The search found an existing structure in the tree.  */
 335     result = ((known_function *) *found)->fct_ptr;
 336   else
 337     {
 338       /* This name was not known before.  Now we have a node in the tree
 339          (in the proper sorted position for FCT_NAME) that points to
 340          &FCT_NAME instead of any real `known_function' structure.
 341          Allocate a new structure and fill it in.  */
 342
 343       known_function *known = malloc (sizeof *known);
 344       if (! known)
 345         {
 346         remove_from_tree:
 347           /* Oops.  We can't instantiate this node properly.
 348              Remove it from the tree.  */
 349           __tdelete (&fct_name, (void **) &ni->known, &known_compare);
 350           result = NULL;
 351         }
 352       else
 353         {
 354           /* Point the tree node at this new structure.  */
 355           *found = known;
 356           known->fct_name = fct_name;
 357
 358           if (ni->library == NULL)
 359             {
 360               /* This service has not yet been used.  Fetch the service
 361                  library for it, creating a new one if need be.  If there
 362                  is no service table from the file, this static variable
 363                  holds the head of the service_library list made from the
 364                  default configuration.  */
 365               static name_database default_table;
 366               ni->library = nss_new_service (service_table ?: &default_table,
 367                                              ni->name);
 368               if (ni->library == NULL)
 369                 {
 370                   /* This only happens when out of memory.  */
 371                   free (known);
 372                   goto remove_from_tree;
 373                 }
 374             }
 375
 376 #if !defined DO_STATIC_NSS || defined PIC
 377           if (ni->library->lib_handle == NULL)
 378             {
 379               /* Load the shared library.  */
 380               size_t shlen = (7 + strlen (ni->library->name) + 3
 381                               + strlen (__nss_shlib_revision) + 1);
 382
 383               struct do_open_args args;
 384               args.shlib_name = __alloca (shlen);
 385               args.ni = ni;
 386
 387               /* Construct shared object name.  */
 388               __stpcpy (__stpcpy (__stpcpy (__stpcpy (args.shlib_name,
 389                                                       "libnss_"),
 390                                             ni->library->name),
 391                                   ".so"),
 392                         __nss_shlib_revision);
 393
 394               if (nss_dlerror_run (do_open, &args) != 0)
 395                 /* Failed to load the library.  */
 396                 ni->library->lib_handle = (void *) -1l;
 397             }
 398
 399           if (ni->library->lib_handle == (void *) -1l)
 400             /* Library not found => function not found.  */
 401             result = NULL;
 402           else
 403             {
 404               /* Get the desired function.  Again,  GNU ld.so magic ahead.  */
 405               size_t namlen = (5 + strlen (ni->library->name) + 1
 406                                + strlen (fct_name) + 1);
 407               struct get_sym_args args;
 408               args.name = __alloca (namlen);
 409               args.map = ni->library->lib_handle;
 410
 411               /* Construct the function name.  */
 412               __stpcpy (__stpcpy (__stpcpy (__stpcpy (args.name, "_nss_"),
 413                                             ni->library->name),
 414                                   "_"),
 415                         fct_name);
 416
 417               /* Look up the symbol.  */
 418               result = (nss_dlerror_run (get_sym, &args) ? NULL
 419                         : (void *) (args.loadbase + args.ref->st_value));
 420             }
 421 #else
 422           /* We can't get function address dynamically in static linking. */
 423           {
 424 # define DEFINE_ENT(h,nm)                                                     \
 425             extern void _nss_##h##_get##nm##ent_r (void);                     \
 426             extern void _nss_##h##_end##nm##ent (void);                       \
 427             extern void _nss_##h##_set##nm##ent (void);
 428 # define DEFINE_GET(h,nm)                                                     \
 429             extern void _nss_##h##_get##nm##_r (void);
 430 # define DEFINE_GETBY(h,nm,ky)                                                \
 431             extern void _nss_##h##_get##nm##by##ky##_r (void);
 432 # include "function.def"
 433 # undef DEFINE_ENT
 434 # undef DEFINE_GET
 435 # undef DEFINE_GETBY
 436 # define DEFINE_ENT(h,nm)                                                     \
 437             { #h"_get"#nm"ent_r", _nss_##h##_get##nm##ent_r },                \
 438             { #h"_end"#nm"ent", _nss_##h##_end##nm##ent },                    \
 439             { #h"_set"#nm"ent", _nss_##h##_set##nm##ent },
 440 # define DEFINE_GET(h,nm)                                                     \
 441             { #h"_get"#nm"_r", _nss_##h##_get##nm##_r },
 442 # define DEFINE_GETBY(h,nm,ky)                                                \
 443             { #h"_get"#nm"by"#ky"_r", _nss_##h##_get##nm##by##ky##_r },
 444             static struct fct_tbl { const char *fname; void *fp; } *tp, tbl[] =
 445               {
 446 # include "function.def"
 447                 { NULL, NULL }
 448               };
 449             size_t namlen = (5 + strlen (ni->library->name) + 1
 450                              + strlen (fct_name) + 1);
 451             char name[namlen];
 452
 453             /* Construct the function name.  */
 454             __stpcpy (__stpcpy (__stpcpy (name, ni->library->name),
 455                                 "_"),
 456                       fct_name);
 457
 458             result = NULL;
 459             for (tp = &tbl[0]; tp->fname; tp++)
 460               if (strcmp (tp->fname, name) == 0)
 461                 {
 462                   result = tp->fp;
 463                   break;
 464                 }
 465           }
 466 #endif
 467
 468           /* Remember function pointer for later calls.  Even if null, we
 469              record it so a second try needn't search the library again.  */
 470           known->fct_ptr = result;
 471         }
 472     }
 473
 474   /* Remove the lock.  */
 475   __libc_lock_unlock (lock);
 476
 477   return result;
 478 }
 479
 480
 481 static name_database *
 482 internal_function
 483 nss_parse_file (const char *fname)
 484 {
 485   FILE *fp;
 486   name_database *result;
 487   name_database_entry *last;
 488   char *line;
 489   size_t len;
 490
 491   /* Open the configuration file.  */
 492   fp = fopen (fname, "r");
 493   if (fp == NULL)
 494     return NULL;
 495
 496   result = (name_database *) malloc (sizeof (name_database));
 497   if (result == NULL)
 498     return NULL;
 499
 500   result->entry = NULL;
 501   result->library = NULL;
 502   last = NULL;
 503   line = NULL;
 504   len = 0;
 505   do
 506     {
 507       name_database_entry *this;
 508       ssize_t n;
 509       char *cp;
 510
 511       n = __getline (&line, &len, fp);
 512       if (n < 0)
 513         break;
 514       if (line[n - 1] == '\n')
 515         line[n - 1] = '\0';
 516
 517       /* Because the file format does not know any form of quoting we
 518          can search forward for the next '#' character and if found
 519          make it terminating the line.  */
 520       cp = strchr (line, '#');
 521       if (cp != NULL)
 522         *cp = '\0';
 523
 524       /* If the line is blank it is ignored.  */
 525       if (line[0] == '\0')
 526         continue;
 527
 528       /* Each line completely specifies the actions for a database.  */
 529       this = nss_getline (line);
 530       if (this != NULL)
 531         {
 532           if (last != NULL)
 533             last->next = this;
 534           else
 535             result->entry = this;
 536
 537           last = this;
 538         }
 539     }
 540   while (!feof (fp));
 541
 542   /* Free the buffer.  */
 543   free (line);
 544   /* Close configuration file.  */
 545   fclose (fp);
 546
 547   return result;
 548 }
 549
 550
 551 /* Read the source names:
 552         `( <source> ( "[" "!"? (<status> "=" <action> )+ "]" )? )*'
 553    */
 554 static service_user *
 555 internal_function
 556 nss_parse_service_list (const char *line)
 557 {
 558   service_user *result = NULL, **nextp = &result;
 559
 560   while (1)
 561     {
 562       service_user *new_service;
 563       const char *name;
 564
 565       while (isspace (line[0]))
 566         ++line;
 567       if (line[0] == '\0')
 568         /* No source specified.  */
 569         return result;
 570
 571       /* Read <source> identifier.  */
 572       name = line;
 573       while (line[0] != '\0' && !isspace (line[0]) && line[0] != '[')
 574         ++line;
 575       if (name == line)
 576         return result;
 577
 578
 579       new_service = (service_user *) malloc (sizeof (service_user));
 580       if (new_service == NULL)
 581         return result;
 582       else
 583         {
 584           char *source = (char *) malloc (line - name + 1);
 585           if (source == NULL)
 586             {
 587               free (new_service);
 588               return result;
 589             }
 590           memcpy (source, name, line - name);
 591           source[line - name] = '\0';
 592
 593           new_service->name = source;
 594         }
 595
 596       /* Set default actions.  */
 597       new_service->actions[2 + NSS_STATUS_TRYAGAIN] = NSS_ACTION_CONTINUE;
 598       new_service->actions[2 + NSS_STATUS_UNAVAIL] = NSS_ACTION_CONTINUE;
 599       new_service->actions[2 + NSS_STATUS_NOTFOUND] = NSS_ACTION_CONTINUE;
 600       new_service->actions[2 + NSS_STATUS_SUCCESS] = NSS_ACTION_RETURN;
 601       new_service->actions[2 + NSS_STATUS_RETURN] = NSS_ACTION_RETURN;
 602       new_service->library = NULL;
 603       new_service->known = NULL;
 604       new_service->next = NULL;
 605
 606       while (isspace (line[0]))
 607         ++line;
 608
 609       if (line[0] == '[')
 610         {
 611           /* Read criterions.  */
 612           do
 613             ++line;
 614           while (line[0] != '\0' && isspace (line[0]));
 615
 616           do
 617             {
 618               int not;
 619               enum nss_status status;
 620               lookup_actions action;
 621
 622               /* Grok ! before name to mean all statii but that one.  */
 623               if (not = line[0] == '!')
 624                 ++line;
 625
 626               /* Read status name.  */
 627               name = line;
 628               while (line[0] != '\0' && !isspace (line[0]) && line[0] != '='
 629                      && line[0] != ']')
 630                 ++line;
 631
 632               /* Compare with known statii.  */
 633               if (line - name == 7)
 634                 {
 635                   if (__strncasecmp (name, "SUCCESS", 7) == 0)
 636                     status = NSS_STATUS_SUCCESS;
 637                   else if (__strncasecmp (name, "UNAVAIL", 7) == 0)
 638                     status = NSS_STATUS_UNAVAIL;
 639                   else
 640                     return result;
 641                 }
 642               else if (line - name == 8)
 643                 {
 644                   if (__strncasecmp (name, "NOTFOUND", 8) == 0)
 645                     status = NSS_STATUS_NOTFOUND;
 646                   else if (__strncasecmp (name, "TRYAGAIN", 8) == 0)
 647                     status = NSS_STATUS_TRYAGAIN;
 648                   else
 649                     return result;
 650                 }
 651               else
 652                 return result;
 653
 654               while (isspace (line[0]))
 655                 ++line;
 656               if (line[0] != '=')
 657                 return result;
 658               do
 659                 ++line;
 660               while (isspace (line[0]));
 661
 662               name = line;
 663               while (line[0] != '\0' && !isspace (line[0]) && line[0] != '='
 664                      && line[0] != ']')
 665                 ++line;
 666
 667               if (line - name == 6 && __strncasecmp (name, "RETURN", 6) == 0)
 668                 action = NSS_ACTION_RETURN;
 669               else if (line - name == 8
 670                        && __strncasecmp (name, "CONTINUE", 8) == 0)
 671                 action = NSS_ACTION_CONTINUE;
 672               else
 673                 return result;
 674
 675               if (not)
 676                 {
 677                   /* Save the current action setting for this status,
 678                      set them all to the given action, and reset this one.  */
 679                   const lookup_actions save = new_service->actions[2 + status];
 680                   new_service->actions[2 + NSS_STATUS_TRYAGAIN] = action;
 681                   new_service->actions[2 + NSS_STATUS_UNAVAIL] = action;
 682                   new_service->actions[2 + NSS_STATUS_NOTFOUND] = action;
 683                   new_service->actions[2 + NSS_STATUS_SUCCESS] = action;
 684                   new_service->actions[2 + status] = save;
 685                 }
 686               else
 687                 new_service->actions[2 + status] = action;
 688
 689               /* Skip white spaces.  */
 690               while (isspace (line[0]))
 691                 ++line;
 692             }
 693           while (line[0] != ']');
 694
 695           /* Skip the ']'.  */
 696           ++line;
 697         }
 698
 699       *nextp = new_service;
 700       nextp = &new_service->next;
 701     }
 702 }
 703
 704 static name_database_entry *
 705 internal_function
 706 nss_getline (char *line)
 707 {
 708   const char *name;
 709   name_database_entry *result;
 710
 711   /* Ignore leading white spaces.  ATTENTION: this is different from
 712      what is implemented in Solaris.  The Solaris man page says a line
 713      beginning with a white space character is ignored.  We regard
 714      this as just another misfeature in Solaris.  */
 715   while (isspace (line[0]))
 716     ++line;
 717
 718   /* Recognize `<database> ":"'.  */
 719   name = line;
 720   while (line[0] != '\0' && !isspace (line[0]) && line[0] != ':')
 721     ++line;
 722   if (line[0] == '\0' || name == line)
 723     /* Syntax error.  */
 724     return NULL;
 725   *line++ = '\0';
 726
 727   result = (name_database_entry *) malloc (sizeof (name_database_entry));
 728   if (result == NULL)
 729     return NULL;
 730
 731   /* Save the database name.  */
 732   {
 733     const size_t len = strlen (name) + 1;
 734     char *new = malloc (len);
 735     if (new == NULL)
 736       {
 737         free (result);
 738         return NULL;
 739       }
 740     result->name = memcpy (new, name, len);
 741   }
 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 }