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