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