nis/nss_compat/compat-grp.c

   1 /* Copyright (C) 1996, 1997, 1998, 1999, 2001 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Thorsten Kukuk <kukuk@suse.de>, 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 Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the 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    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <errno.h>
  21 #include <fcntl.h>
  22 #include <nss.h>
  23 #include <grp.h>
  24 #include <ctype.h>
  25 #include <bits/libc-lock.h>
  26 #include <string.h>
  27 #include <rpcsvc/yp.h>
  28 #include <rpcsvc/ypclnt.h>
  29 #include <rpcsvc/nis.h>
  30 #include <nsswitch.h>
  31
  32 #include "nss-nisplus.h"
  33 #include "nisplus-parser.h"
  34
  35 static service_user *ni;
  36 static bool_t use_nisplus; /* default: group_compat: nis */
  37 static nis_name grptable; /* Name of the group table */
  38 static size_t grptablelen;
  39
  40 /* Get the declaration of the parser function.  */
  41 #define ENTNAME grent
  42 #define STRUCTURE group
  43 #define EXTERN_PARSER
  44 #include <nss/nss_files/files-parse.c>
  45
  46 /* Structure for remembering -group members ... */
  47 #define BLACKLIST_INITIAL_SIZE 512
  48 #define BLACKLIST_INCREMENT 256
  49 struct blacklist_t
  50   {
  51     char *data;
  52     int current;
  53     int size;
  54   };
  55
  56 struct ent_t
  57   {
  58     bool_t nis;
  59     bool_t nis_first;
  60     char *oldkey;
  61     int oldkeylen;
  62     nis_result *result;
  63     FILE *stream;
  64     struct blacklist_t blacklist;
  65 };
  66 typedef struct ent_t ent_t;
  67
  68 static ent_t ext_ent = {0, 0, NULL, 0, NULL, NULL, {NULL, 0, 0}};
  69
  70 /* Protect global state against multiple changers.  */
  71 __libc_lock_define_initialized (static, lock)
  72
  73 /* Prototypes for local functions.  */
  74 static void blacklist_store_name (const char *, ent_t *);
  75 static int in_blacklist (const char *, int, ent_t *);
  76
  77 static enum nss_status
  78 _nss_first_init (void)
  79 {
  80   if (ni == NULL)
  81     {
  82       __nss_database_lookup ("group_compat", NULL, "nis", &ni);
  83       use_nisplus = (strcmp (ni->name, "nisplus") == 0);
  84     }
  85
  86   if (grptable == NULL)
  87     {
  88       static const char key[] = "group.org_dir.";
  89       const char *local_dir = nis_local_directory ();
  90       size_t len_local_dir = strlen (local_dir);
  91
  92       grptable = malloc (sizeof (key) + len_local_dir);
  93       if (grptable == NULL)
  94         return NSS_STATUS_TRYAGAIN;
  95
  96       grptablelen = ((char *) mempcpy (mempcpy (grptable,
  97                                                 key, sizeof (key) - 1),
  98                                        local_dir, len_local_dir + 1)
  99                      - grptable) - 1;
 100     }
 101
 102   return NSS_STATUS_SUCCESS;
 103 }
 104
 105 static enum nss_status
 106 internal_setgrent (ent_t *ent)
 107 {
 108   enum nss_status status = NSS_STATUS_SUCCESS;
 109
 110   ent->nis = ent->nis_first = 0;
 111
 112   if (_nss_first_init () != NSS_STATUS_SUCCESS)
 113     return NSS_STATUS_UNAVAIL;
 114
 115   if (ent->oldkey != NULL)
 116     {
 117       free (ent->oldkey);
 118       ent->oldkey = NULL;
 119       ent->oldkeylen = 0;
 120     }
 121
 122   if (ent->result != NULL)
 123     {
 124       nis_freeresult (ent->result);
 125       ent->result = NULL;
 126     }
 127
 128   if (ent->blacklist.data != NULL)
 129     {
 130       ent->blacklist.current = 1;
 131       ent->blacklist.data[0] = '|';
 132       ent->blacklist.data[1] = '\0';
 133     }
 134   else
 135     ent->blacklist.current = 0;
 136
 137   if (ent->stream == NULL)
 138     {
 139       ent->stream = fopen ("/etc/group", "r");
 140
 141       if (ent->stream == NULL)
 142         status = errno == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;
 143       else
 144         {
 145           /* We have to make sure the file is  `closed on exec'.  */
 146           int result, flags;
 147
 148           result = flags = fcntl (fileno (ent->stream), F_GETFD, 0);
 149           if (result >= 0)
 150             {
 151               flags |= FD_CLOEXEC;
 152               result = fcntl (fileno (ent->stream), F_SETFD, flags);
 153             }
 154           if (result < 0)
 155             {
 156               /* Something went wrong.  Close the stream and return a
 157                  failure.  */
 158               fclose (ent->stream);
 159               ent->stream = NULL;
 160               status = NSS_STATUS_UNAVAIL;
 161             }
 162         }
 163     }
 164   else
 165     rewind (ent->stream);
 166
 167   return status;
 168 }
 169
 170
 171 enum nss_status
 172 _nss_compat_setgrent (int stayopen)
 173 {
 174   enum nss_status result;
 175
 176   __libc_lock_lock (lock);
 177
 178   result = internal_setgrent (&ext_ent);
 179
 180   __libc_lock_unlock (lock);
 181
 182   return result;
 183 }
 184
 185
 186 static enum nss_status
 187 internal_endgrent (ent_t *ent)
 188 {
 189   if (ent->stream != NULL)
 190     {
 191       fclose (ent->stream);
 192       ent->stream = NULL;
 193     }
 194
 195   ent->nis = ent->nis_first = 0;
 196
 197   if (ent->oldkey != NULL)
 198     {
 199       free (ent->oldkey);
 200       ent->oldkey = NULL;
 201       ent->oldkeylen = 0;
 202     }
 203
 204   if (ent->result != NULL)
 205     {
 206       nis_freeresult (ent->result);
 207       ent->result = NULL;
 208     }
 209
 210   if (ent->blacklist.data != NULL)
 211     {
 212       ent->blacklist.current = 1;
 213       ent->blacklist.data[0] = '|';
 214       ent->blacklist.data[1] = '\0';
 215     }
 216   else
 217     ent->blacklist.current = 0;
 218
 219   return NSS_STATUS_SUCCESS;
 220 }
 221
 222 enum nss_status
 223 _nss_compat_endgrent (void)
 224 {
 225   enum nss_status result;
 226
 227   __libc_lock_lock (lock);
 228
 229   result = internal_endgrent (&ext_ent);
 230
 231   __libc_lock_unlock (lock);
 232
 233   return result;
 234 }
 235
 236 static enum nss_status
 237 getgrent_next_nis (struct group *result, ent_t *ent, char *buffer,
 238                    size_t buflen, int *errnop)
 239 {
 240   struct parser_data *data = (void *) buffer;
 241   char *domain;
 242   char *outkey, *outval;
 243   int outkeylen, outvallen, parse_res;
 244   char *p;
 245
 246   if (yp_get_default_domain (&domain) != YPERR_SUCCESS)
 247     {
 248       ent->nis = 0;
 249       *errnop = ENOENT;
 250       return NSS_STATUS_NOTFOUND;
 251     }
 252
 253   do
 254     {
 255       char *save_oldkey;
 256       int save_oldlen;
 257       bool_t save_nis_first;
 258
 259       if (ent->nis_first)
 260         {
 261           if (yp_first (domain, "group.byname", &outkey, &outkeylen,
 262                         &outval, &outvallen) != YPERR_SUCCESS)
 263             {
 264               ent->nis = 0;
 265               return NSS_STATUS_UNAVAIL;
 266             }
 267
 268           if ( buflen < ((size_t) outvallen + 1))
 269             {
 270               free (outval);
 271               *errnop = ERANGE;
 272               return NSS_STATUS_TRYAGAIN;
 273             }
 274
 275           save_oldkey = ent->oldkey;
 276           save_oldlen = ent->oldkeylen;
 277           save_nis_first = TRUE;
 278           ent->oldkey = outkey;
 279           ent->oldkeylen = outkeylen;
 280           ent->nis_first = FALSE;
 281         }
 282       else
 283         {
 284           if (yp_next (domain, "group.byname", ent->oldkey, ent->oldkeylen,
 285                        &outkey, &outkeylen, &outval, &outvallen)
 286               != YPERR_SUCCESS)
 287             {
 288               ent->nis = 0;
 289               *errnop = ENOENT;
 290               return NSS_STATUS_NOTFOUND;
 291             }
 292
 293           if ( buflen < ((size_t) outvallen + 1))
 294             {
 295               free (outval);
 296               *errnop = ERANGE;
 297               return NSS_STATUS_TRYAGAIN;
 298             }
 299
 300           save_oldkey = ent->oldkey;
 301           save_oldlen = ent->oldkeylen;
 302           save_nis_first = FALSE;
 303           ent->oldkey = outkey;
 304           ent->oldkeylen = outkeylen;
 305         }
 306
 307       /* Copy the found data to our buffer...  */
 308       p = strncpy (buffer, outval, buflen);
 309
 310       /* ...and free the data.  */
 311       free (outval);
 312
 313       while (isspace (*p))
 314         ++p;
 315
 316       parse_res = _nss_files_parse_grent (p, result, data, buflen, errnop);
 317       if (parse_res == -1)
 318         {
 319           free (ent->oldkey);
 320           ent->oldkey = save_oldkey;
 321           ent->oldkeylen = save_oldlen;
 322           ent->nis_first = save_nis_first;
 323           *errnop = ERANGE;
 324           return NSS_STATUS_TRYAGAIN;
 325         }
 326       else
 327         {
 328           if (!save_nis_first)
 329             free (save_oldkey);
 330         }
 331
 332       if (parse_res &&
 333           in_blacklist (result->gr_name, strlen (result->gr_name), ent))
 334         parse_res = 0; /* if result->gr_name in blacklist,search next entry */
 335     }
 336   while (!parse_res);
 337
 338   return NSS_STATUS_SUCCESS;
 339 }
 340
 341 static enum nss_status
 342 getgrent_next_nisplus (struct group *result, ent_t *ent, char *buffer,
 343                        size_t buflen, int *errnop)
 344 {
 345   int parse_res;
 346
 347   do
 348     {
 349       nis_result *save_oldres;
 350       bool_t save_nis_first;
 351
 352       if (ent->nis_first)
 353         {
 354           save_oldres = ent->result;
 355           save_nis_first = TRUE;
 356           ent->result = nis_first_entry(grptable);
 357           if (niserr2nss (ent->result->status) != NSS_STATUS_SUCCESS)
 358             {
 359               ent->nis = 0;
 360               return niserr2nss (ent->result->status);
 361             }
 362           ent->nis_first = FALSE;
 363         }
 364       else
 365         {
 366           nis_result *res;
 367
 368           save_oldres = ent->result;
 369           save_nis_first = FALSE;
 370           res = nis_next_entry(grptable, &ent->result->cookie);
 371           ent->result = res;
 372           if (niserr2nss (ent->result->status) != NSS_STATUS_SUCCESS)
 373             {
 374               ent->nis = 0;
 375               return niserr2nss (ent->result->status);
 376             }
 377         }
 378       parse_res = _nss_nisplus_parse_grent (ent->result, 0, result,
 379                                             buffer, buflen, errnop);
 380       if (parse_res == -1)
 381         {
 382           nis_freeresult (ent->result);
 383           ent->result = save_oldres;
 384           ent->nis_first = save_nis_first;
 385           *errnop = ERANGE;
 386           return NSS_STATUS_TRYAGAIN;
 387         }
 388       else
 389         {
 390           if (!save_nis_first)
 391             nis_freeresult (save_oldres);
 392         }
 393
 394       if (parse_res &&
 395           in_blacklist (result->gr_name, strlen (result->gr_name), ent))
 396         parse_res = 0; /* if result->gr_name in blacklist,search next entry */
 397     }
 398   while (!parse_res);
 399
 400   return NSS_STATUS_SUCCESS;
 401 }
 402
 403 /* This function handle the +group entrys in /etc/group */
 404 static enum nss_status
 405 getgrnam_plusgroup (const char *name, struct group *result, char *buffer,
 406                     size_t buflen, int *errnop)
 407 {
 408   struct parser_data *data = (void *) buffer;
 409   int parse_res;
 410
 411   if (use_nisplus) /* Do the NIS+ query here */
 412     {
 413       nis_result *res;
 414       char buf[strlen (name) + 24 + grptablelen];
 415
 416       sprintf(buf, "[name=%s],%s", name, grptable);
 417       res = nis_list(buf, FOLLOW_PATH | FOLLOW_LINKS, NULL, NULL);
 418       if (niserr2nss (res->status) != NSS_STATUS_SUCCESS)
 419         {
 420           enum nss_status status =  niserr2nss (res->status);
 421
 422           nis_freeresult (res);
 423           return status;
 424         }
 425       parse_res = _nss_nisplus_parse_grent (res, 0, result, buffer, buflen,
 426                                             errnop);
 427       if (parse_res == -1)
 428         {
 429           nis_freeresult (res);
 430           *errnop = ERANGE;
 431           return NSS_STATUS_TRYAGAIN;
 432         }
 433       nis_freeresult (res);
 434     }
 435   else /* Use NIS */
 436     {
 437       char *domain, *outval, *p;
 438       int outvallen;
 439
 440       if (yp_get_default_domain (&domain) != YPERR_SUCCESS)
 441         {
 442           *errnop = ENOENT;
 443           return NSS_STATUS_NOTFOUND;
 444         }
 445
 446       if (yp_match (domain, "group.byname", name, strlen (name),
 447                     &outval, &outvallen) != YPERR_SUCCESS)
 448         {
 449           *errnop = ENOENT;
 450           return NSS_STATUS_NOTFOUND;
 451         }
 452
 453       if (buflen < ((size_t) outvallen + 1))
 454         {
 455           free (outval);
 456           *errnop = ERANGE;
 457           return NSS_STATUS_TRYAGAIN;
 458         }
 459
 460       /* Copy the found data to our buffer...  */
 461       p = strncpy (buffer, outval, buflen);
 462
 463       /* ... and free the data.  */
 464       free (outval);
 465       while (isspace (*p))
 466         ++p;
 467       parse_res = _nss_files_parse_grent (p, result, data, buflen, errnop);
 468       if (parse_res == -1)
 469         return NSS_STATUS_TRYAGAIN;
 470     }
 471
 472   if (parse_res)
 473     /* We found the entry.  */
 474     return NSS_STATUS_SUCCESS;
 475   else
 476     return NSS_STATUS_RETURN;
 477 }
 478
 479 static enum nss_status
 480 getgrent_next_file (struct group *result, ent_t *ent,
 481                     char *buffer, size_t buflen, int *errnop)
 482 {
 483   struct parser_data *data = (void *) buffer;
 484   while (1)
 485     {
 486       fpos_t pos;
 487       int parse_res = 0;
 488       char *p;
 489
 490       do
 491         {
 492           fgetpos (ent->stream, &pos);
 493           buffer[buflen - 1] = '\xff';
 494           p = fgets (buffer, buflen, ent->stream);
 495           if (p == NULL && feof (ent->stream))
 496             {
 497               *errnop = ENOENT;
 498               return NSS_STATUS_NOTFOUND;
 499             }
 500           if (p == NULL || buffer[buflen - 1] != '\xff')
 501             {
 502               fsetpos (ent->stream, &pos);
 503               *errnop = ERANGE;
 504               return NSS_STATUS_TRYAGAIN;
 505             }
 506
 507           /* Terminate the line for any case.  */
 508           buffer[buflen - 1] = '\0';
 509
 510           /* Skip leading blanks.  */
 511           while (isspace (*p))
 512             ++p;
 513         }
 514       while (*p == '\0' || *p == '#' || /* Ignore empty and comment lines. */
 515       /* Parse the line.  If it is invalid, loop to
 516          get the next line of the file to parse.  */
 517              !(parse_res = _nss_files_parse_grent (p, result, data, buflen,
 518                                                    errnop)));
 519
 520       if (parse_res == -1)
 521         {
 522           /* The parser ran out of space.  */
 523           fsetpos (ent->stream, &pos);
 524           *errnop = ERANGE;
 525           return NSS_STATUS_TRYAGAIN;
 526         }
 527
 528       if (result->gr_name[0] != '+' && result->gr_name[0] != '-')
 529         /* This is a real entry.  */
 530         break;
 531
 532       /* -group */
 533       if (result->gr_name[0] == '-' && result->gr_name[1] != '\0'
 534           && result->gr_name[1] != '@')
 535         {
 536           blacklist_store_name (&result->gr_name[1], ent);
 537           continue;
 538         }
 539
 540       /* +group */
 541       if (result->gr_name[0] == '+' && result->gr_name[1] != '\0'
 542           && result->gr_name[1] != '@')
 543         {
 544           enum nss_status status;
 545
 546           /* Store the group in the blacklist for the "+" at the end of
 547              /etc/group */
 548           blacklist_store_name (&result->gr_name[1], ent);
 549           status = getgrnam_plusgroup (&result->gr_name[1], result, buffer,
 550                                        buflen, errnop);
 551           if (status == NSS_STATUS_SUCCESS) /* We found the entry. */
 552             break;
 553           else
 554             if (status == NSS_STATUS_RETURN /* We couldn't parse the entry */
 555                 || status == NSS_STATUS_NOTFOUND) /* No group in NIS */
 556               continue;
 557             else
 558               {
 559                 if (status == NSS_STATUS_TRYAGAIN)
 560                   {
 561                     /* The parser ran out of space.  */
 562                     fsetpos (ent->stream, &pos);
 563                     *errnop = ERANGE;
 564                   }
 565                 return status;
 566               }
 567         }
 568
 569       /* +:... */
 570       if (result->gr_name[0] == '+' && result->gr_name[1] == '\0')
 571         {
 572           ent->nis = TRUE;
 573           ent->nis_first = TRUE;
 574
 575           if (use_nisplus)
 576             return getgrent_next_nisplus (result, ent, buffer, buflen, errnop);
 577           else
 578             return getgrent_next_nis (result, ent, buffer, buflen, errnop);
 579         }
 580     }
 581
 582   return NSS_STATUS_SUCCESS;
 583 }
 584
 585
 586 static enum nss_status
 587 internal_getgrent_r (struct group *gr, ent_t *ent, char *buffer,
 588                      size_t buflen, int *errnop)
 589 {
 590   if (ent->nis)
 591     {
 592       if (use_nisplus)
 593         return getgrent_next_nisplus (gr, ent, buffer, buflen, errnop);
 594       else
 595         return getgrent_next_nis (gr, ent, buffer, buflen, errnop);
 596     }
 597   else
 598     return getgrent_next_file (gr, ent, buffer, buflen, errnop);
 599 }
 600
 601 enum nss_status
 602 _nss_compat_getgrent_r (struct group *grp, char *buffer, size_t buflen,
 603                         int *errnop)
 604 {
 605   enum nss_status status = NSS_STATUS_SUCCESS;
 606
 607   __libc_lock_lock (lock);
 608
 609   /* Be prepared that the setgrent function was not called before.  */
 610   if (ext_ent.stream == NULL)
 611     status = internal_setgrent (&ext_ent);
 612
 613   if (status == NSS_STATUS_SUCCESS)
 614     status = internal_getgrent_r (grp, &ext_ent, buffer, buflen, errnop);
 615
 616   __libc_lock_unlock (lock);
 617
 618   return status;
 619 }
 620
 621 /* Searches in /etc/group and the NIS/NIS+ map for a special group */
 622 static enum nss_status
 623 internal_getgrnam_r (const char *name, struct group *result, ent_t *ent,
 624                      char *buffer, size_t buflen, int *errnop)
 625 {
 626   struct parser_data *data = (void *) buffer;
 627   while (1)
 628     {
 629       fpos_t pos;
 630       int parse_res = 0;
 631       char *p;
 632
 633       do
 634         {
 635           fgetpos (ent->stream, &pos);
 636           buffer[buflen - 1] = '\xff';
 637           p = fgets (buffer, buflen, ent->stream);
 638           if (p == NULL && feof (ent->stream))
 639             {
 640               *errnop = ENOENT;
 641               return NSS_STATUS_NOTFOUND;
 642             }
 643           if (p == NULL || buffer[buflen - 1] != '\xff')
 644             {
 645               fsetpos (ent->stream, &pos);
 646               *errnop = ERANGE;
 647               return NSS_STATUS_TRYAGAIN;
 648             }
 649
 650           /* Terminate the line for any case.  */
 651           buffer[buflen - 1] = '\0';
 652
 653           /* Skip leading blanks.  */
 654           while (isspace (*p))
 655             ++p;
 656         }
 657       while (*p == '\0' || *p == '#' || /* Ignore empty and comment lines. */
 658       /* Parse the line.  If it is invalid, loop to
 659          get the next line of the file to parse.  */
 660              !(parse_res = _nss_files_parse_grent (p, result, data, buflen,
 661                                                    errnop)));
 662
 663       if (parse_res == -1)
 664         {
 665           /* The parser ran out of space.  */
 666           fsetpos (ent->stream, &pos);
 667           *errnop = ERANGE;
 668           return NSS_STATUS_TRYAGAIN;
 669         }
 670
 671       /* This is a real entry.  */
 672       if (result->gr_name[0] != '+' && result->gr_name[0] != '-')
 673         {
 674           if (strcmp (result->gr_name, name) == 0)
 675             return NSS_STATUS_SUCCESS;
 676           else
 677             continue;
 678         }
 679
 680       /* -group */
 681       if (result->gr_name[0] == '-' && result->gr_name[1] != '\0')
 682         {
 683           if (strcmp (&result->gr_name[1], name) == 0)
 684             {
 685               *errnop = ENOENT;
 686               return NSS_STATUS_NOTFOUND;
 687             }
 688           else
 689             continue;
 690         }
 691
 692       /* +group */
 693       if (result->gr_name[0] == '+' && result->gr_name[1] != '\0')
 694         {
 695           if (strcmp (name, &result->gr_name[1]) == 0)
 696             {
 697               enum nss_status status;
 698
 699               status = getgrnam_plusgroup (name, result, buffer, buflen,
 700                                            errnop);
 701               if (status == NSS_STATUS_RETURN)
 702                 /* We couldn't parse the entry */
 703                 continue;
 704               else
 705                 return status;
 706             }
 707         }
 708       /* +:... */
 709       if (result->gr_name[0] == '+' && result->gr_name[1] == '\0')
 710         {
 711           enum nss_status status;
 712
 713           status = getgrnam_plusgroup (name, result, buffer, buflen, errnop);
 714           if (status == NSS_STATUS_RETURN)
 715             /* We couldn't parse the entry */
 716             continue;
 717           else
 718             return status;
 719         }
 720     }
 721
 722   return NSS_STATUS_SUCCESS;
 723 }
 724
 725 enum nss_status
 726 _nss_compat_getgrnam_r (const char *name, struct group *grp,
 727                         char *buffer, size_t buflen, int *errnop)
 728 {
 729   ent_t ent = {0, 0, NULL, 0, NULL, NULL, {NULL, 0, 0}};
 730   enum nss_status status;
 731
 732   if (name[0] == '-' || name[0] == '+')
 733     {
 734       *errnop = ENOENT;
 735       return NSS_STATUS_NOTFOUND;
 736     }
 737
 738   __libc_lock_lock (lock);
 739
 740   status = internal_setgrent (&ent);
 741
 742   __libc_lock_unlock (lock);
 743
 744   if (status != NSS_STATUS_SUCCESS)
 745     return status;
 746
 747   status = internal_getgrnam_r (name, grp, &ent, buffer, buflen, errnop);
 748
 749   internal_endgrent (&ent);
 750
 751   return status;
 752 }
 753
 754 /* This function handle the + entry in /etc/group */
 755 static enum nss_status
 756 getgrgid_plusgroup (gid_t gid, struct group *result, char *buffer,
 757                     size_t buflen, int *errnop)
 758 {
 759   struct parser_data *data = (void *) buffer;
 760   int parse_res;
 761
 762   if (use_nisplus) /* Do the NIS+ query here */
 763     {
 764       nis_result *res;
 765       char buf[24 + grptablelen];
 766
 767       sprintf(buf, "[gid=%d],%s", gid, grptable);
 768       res = nis_list(buf, FOLLOW_PATH | FOLLOW_LINKS, NULL, NULL);
 769       if (niserr2nss (res->status) != NSS_STATUS_SUCCESS)
 770         {
 771           enum nss_status status =  niserr2nss (res->status);
 772
 773           nis_freeresult (res);
 774           return status;
 775         }
 776       if ((parse_res = _nss_nisplus_parse_grent (res, 0, result, buffer,
 777                                                  buflen, errnop)) == -1)
 778         {
 779           nis_freeresult (res);
 780           *errnop = ERANGE;
 781           return NSS_STATUS_TRYAGAIN;
 782         }
 783       nis_freeresult (res);
 784     }
 785   else /* Use NIS */
 786     {
 787       char buf[24];
 788       char *domain, *outval, *p;
 789       int outvallen;
 790
 791       if (yp_get_default_domain (&domain) != YPERR_SUCCESS)
 792         {
 793           *errnop = ENOENT;
 794           return NSS_STATUS_NOTFOUND;
 795         }
 796
 797       snprintf (buf, sizeof (buf), "%d", gid);
 798
 799       if (yp_match (domain, "group.bygid", buf, strlen (buf),
 800                     &outval, &outvallen) != YPERR_SUCCESS)
 801         {
 802           *errnop = ENOENT;
 803           return NSS_STATUS_NOTFOUND;
 804         }
 805
 806       if (buflen < ((size_t) outvallen + 1))
 807         {
 808           free (outval);
 809           *errnop = ERANGE;
 810           return NSS_STATUS_TRYAGAIN;
 811         }
 812
 813       /* Copy the found data to our buffer...  */
 814       p = strncpy (buffer, outval, buflen);
 815
 816       /* ... and free the data.  */
 817       free (outval);
 818
 819       while (isspace (*p))
 820         p++;
 821       parse_res = _nss_files_parse_grent (p, result, data, buflen, errnop);
 822       if (parse_res == -1)
 823         return NSS_STATUS_TRYAGAIN;
 824     }
 825
 826   if (parse_res)
 827     /* We found the entry.  */
 828     return NSS_STATUS_SUCCESS;
 829   else
 830     return NSS_STATUS_RETURN;
 831 }
 832
 833 /* Searches in /etc/group and the NIS/NIS+ map for a special group id */
 834 static enum nss_status
 835 internal_getgrgid_r (gid_t gid, struct group *result, ent_t *ent,
 836                      char *buffer, size_t buflen, int *errnop)
 837 {
 838   struct parser_data *data = (void *) buffer;
 839   while (1)
 840     {
 841       fpos_t pos;
 842       int parse_res = 0;
 843       char *p;
 844
 845       do
 846         {
 847           fgetpos (ent->stream, &pos);
 848           buffer[buflen - 1] = '\xff';
 849           p = fgets (buffer, buflen, ent->stream);
 850           if (p == NULL && feof (ent->stream))
 851             {
 852               *errnop = ENOENT;
 853               return NSS_STATUS_NOTFOUND;
 854             }
 855           if (p == NULL || buffer[buflen - 1] != '\xff')
 856             {
 857               fsetpos (ent->stream, &pos);
 858               *errnop = ERANGE;
 859               return NSS_STATUS_TRYAGAIN;
 860             }
 861
 862           /* Terminate the line for any case.  */
 863           buffer[buflen - 1] = '\0';
 864
 865           /* Skip leading blanks.  */
 866           while (isspace (*p))
 867             ++p;
 868         }
 869       while (*p == '\0' || *p == '#' || /* Ignore empty and comment lines. */
 870       /* Parse the line.  If it is invalid, loop to
 871          get the next line of the file to parse.  */
 872              !(parse_res = _nss_files_parse_grent (p, result, data, buflen,
 873                                                    errnop)));
 874
 875       if (parse_res == -1)
 876         {
 877           /* The parser ran out of space.  */
 878           fsetpos (ent->stream, &pos);
 879           *errnop = ERANGE;
 880           return NSS_STATUS_TRYAGAIN;
 881         }
 882
 883       /* This is a real entry.  */
 884       if (result->gr_name[0] != '+' && result->gr_name[0] != '-')
 885         {
 886           if (result->gr_gid == gid)
 887             return NSS_STATUS_SUCCESS;
 888           else
 889             continue;
 890         }
 891
 892       /* -group */
 893       if (result->gr_name[0] == '-' && result->gr_name[1] != '\0')
 894         {
 895           blacklist_store_name (&result->gr_name[1], ent);
 896           continue;
 897         }
 898
 899       /* +group */
 900       if (result->gr_name[0] == '+' && result->gr_name[1] != '\0')
 901         {
 902           enum nss_status status;
 903
 904           /* Store the group in the blacklist for the "+" at the end of
 905              /etc/group */
 906           blacklist_store_name (&result->gr_name[1], ent);
 907           status = getgrnam_plusgroup (&result->gr_name[1], result, buffer,
 908                                       buflen, errnop);
 909           if (status == NSS_STATUS_SUCCESS && result->gr_gid == gid)
 910             break;
 911           else
 912             continue;
 913         }
 914       /* +:... */
 915       if (result->gr_name[0] == '+' && result->gr_name[1] == '\0')
 916         {
 917           enum nss_status status;
 918
 919           status = getgrgid_plusgroup (gid, result, buffer, buflen, errnop);
 920           if (status == NSS_STATUS_RETURN) /* We couldn't parse the entry */
 921             {
 922               *errnop = ENOENT;
 923               return NSS_STATUS_NOTFOUND;
 924             }
 925           else
 926             return status;
 927         }
 928     }
 929
 930   return NSS_STATUS_SUCCESS;
 931 }
 932
 933 enum nss_status
 934 _nss_compat_getgrgid_r (gid_t gid, struct group *grp,
 935                         char *buffer, size_t buflen, int *errnop)
 936 {
 937   ent_t ent = {0, 0, NULL, 0, NULL, NULL, {NULL, 0, 0}};
 938   enum nss_status status;
 939
 940   __libc_lock_lock (lock);
 941
 942   status = internal_setgrent (&ent);
 943
 944   __libc_lock_unlock (lock);
 945
 946   if (status != NSS_STATUS_SUCCESS)
 947     return status;
 948
 949   status = internal_getgrgid_r (gid, grp, &ent, buffer, buflen, errnop);
 950
 951   internal_endgrent (&ent);
 952
 953   return status;
 954 }
 955
 956
 957 /* Support routines for remembering -@netgroup and -user entries.
 958    The names are stored in a single string with `|' as separator. */
 959 static void
 960 blacklist_store_name (const char *name, ent_t *ent)
 961 {
 962   int namelen = strlen (name);
 963   char *tmp;
 964
 965   /* first call, setup cache */
 966   if (ent->blacklist.size == 0)
 967     {
 968       ent->blacklist.size = MAX (BLACKLIST_INITIAL_SIZE, 2 * namelen);
 969       ent->blacklist.data = malloc (ent->blacklist.size);
 970       if (ent->blacklist.data == NULL)
 971         return;
 972       ent->blacklist.data[0] = '|';
 973       ent->blacklist.data[1] = '\0';
 974       ent->blacklist.current = 1;
 975     }
 976   else
 977     {
 978       if (in_blacklist (name, namelen, ent))
 979         return;                 /* no duplicates */
 980
 981       if (ent->blacklist.current + namelen + 1 >= ent->blacklist.size)
 982         {
 983           ent->blacklist.size += MAX (BLACKLIST_INCREMENT, 2 * namelen);
 984           tmp = realloc (ent->blacklist.data, ent->blacklist.size);
 985           if (tmp == NULL)
 986             {
 987               free (ent->blacklist.data);
 988               ent->blacklist.size = 0;
 989               return;
 990             }
 991           ent->blacklist.data = tmp;
 992         }
 993     }
 994
 995   tmp = stpcpy (ent->blacklist.data + ent->blacklist.current, name);
 996   *tmp++ = '|';
 997   *tmp = '\0';
 998   ent->blacklist.current += namelen + 1;
 999
1000   return;
1001 }
1002
1003 /* returns TRUE if ent->blacklist contains name, else FALSE */
1004 static bool_t
1005 in_blacklist (const char *name, int namelen, ent_t *ent)
1006 {
1007   char buf[namelen + 3];
1008   char *cp;
1009
1010   if (ent->blacklist.data == NULL)
1011     return FALSE;
1012
1013   buf[0] = '|';
1014   cp = stpcpy (&buf[1], name);
1015   *cp++= '|';
1016   *cp = '\0';
1017   return strstr (ent->blacklist.data, buf) != NULL;
1018 }