nis/nss_compat/compat-grp.c

   1 /* Copyright (C) 1996,1997,1998,1999,2001,2002, 2003 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 <ctype.h>
  21 #include <errno.h>
  22 #include <fcntl.h>
  23 #include <grp.h>
  24 #include <nss.h>
  25 #include <nsswitch.h>
  26 #include <stdio_ext.h>
  27 #include <string.h>
  28 #include <rpc/types.h>
  29 #include <bits/libc-lock.h>
  30
  31 static service_user *ni;
  32 static enum nss_status (*nss_setgrent) (int stayopen);
  33 static enum nss_status (*nss_getgrnam_r) (const char *name,
  34                                           struct group * grp, char *buffer,
  35                                           size_t buflen, int *errnop);
  36 static enum nss_status (*nss_getgrgid_r) (gid_t gid, struct group * grp,
  37                                           char *buffer, size_t buflen,
  38                                           int *errnop);
  39 static enum nss_status (*nss_getgrent_r) (struct group * grp, char *buffer,
  40                                           size_t buflen, int *errnop);
  41 static enum nss_status (*nss_endgrent) (void);
  42
  43 /* Get the declaration of the parser function.  */
  44 #define ENTNAME grent
  45 #define STRUCTURE group
  46 #define EXTERN_PARSER
  47 #include <nss/nss_files/files-parse.c>
  48
  49 /* Structure for remembering -group members ... */
  50 #define BLACKLIST_INITIAL_SIZE 512
  51 #define BLACKLIST_INCREMENT 256
  52 struct blacklist_t
  53 {
  54   char *data;
  55   int current;
  56   int size;
  57 };
  58
  59 struct ent_t
  60 {
  61   bool_t files;
  62   FILE *stream;
  63   struct blacklist_t blacklist;
  64 };
  65 typedef struct ent_t ent_t;
  66
  67 static ent_t ext_ent = {TRUE, NULL, {NULL, 0, 0}};
  68
  69 /* Protect global state against multiple changers.  */
  70 __libc_lock_define_initialized (static, lock)
  71
  72 /* Prototypes for local functions.  */
  73 static void blacklist_store_name (const char *, ent_t *);
  74 static int in_blacklist (const char *, int, ent_t *);
  75
  76 /* Initialize the NSS interface/functions. The calling function must
  77    hold the lock.  */
  78 static void
  79 init_nss_interface (void)
  80 {
  81   if (__nss_database_lookup ("group_compat", NULL, "nis", &ni) >= 0)
  82     {
  83       nss_setgrent = __nss_lookup_function (ni, "setgrent");
  84       nss_getgrnam_r = __nss_lookup_function (ni, "getgrnam_r");
  85       nss_getgrgid_r = __nss_lookup_function (ni, "getgrgid_r");
  86       nss_getgrent_r = __nss_lookup_function (ni, "getgrent_r");
  87       nss_endgrent = __nss_lookup_function (ni, "endgrent");
  88     }
  89 }
  90
  91 static enum nss_status
  92 internal_setgrent (ent_t *ent, int stayopen)
  93 {
  94   enum nss_status status = NSS_STATUS_SUCCESS;
  95
  96   ent->files = TRUE;
  97
  98   if (ent->blacklist.data != NULL)
  99     {
 100       ent->blacklist.current = 1;
 101       ent->blacklist.data[0] = '|';
 102       ent->blacklist.data[1] = '\0';
 103     }
 104   else
 105     ent->blacklist.current = 0;
 106
 107   if (ent->stream == NULL)
 108     {
 109       ent->stream = fopen ("/etc/group", "rm");
 110
 111       if (ent->stream == NULL)
 112         status = errno == EAGAIN ? NSS_STATUS_TRYAGAIN : NSS_STATUS_UNAVAIL;
 113       else
 114         {
 115           /* We have to make sure the file is  `closed on exec'.  */
 116           int result, flags;
 117
 118           result = flags = fcntl (fileno_unlocked (ent->stream), F_GETFD, 0);
 119           if (result >= 0)
 120             {
 121               flags |= FD_CLOEXEC;
 122               result = fcntl (fileno_unlocked (ent->stream), F_SETFD, flags);
 123             }
 124           if (result < 0)
 125             {
 126               /* Something went wrong.  Close the stream and return a
 127                  failure.  */
 128               fclose (ent->stream);
 129               ent->stream = NULL;
 130               status = NSS_STATUS_UNAVAIL;
 131             }
 132           else
 133             /* We take care of locking ourself.  */
 134             __fsetlocking (ent->stream, FSETLOCKING_BYCALLER);
 135         }
 136     }
 137   else
 138     rewind (ent->stream);
 139
 140   if (status == NSS_STATUS_SUCCESS && nss_setgrent)
 141     return nss_setgrent (stayopen);
 142
 143   return status;
 144 }
 145
 146
 147 enum nss_status
 148 _nss_compat_setgrent (int stayopen)
 149 {
 150   enum nss_status result;
 151
 152   __libc_lock_lock (lock);
 153
 154   if (ni == NULL)
 155     init_nss_interface ();
 156
 157   result = internal_setgrent (&ext_ent, stayopen);
 158
 159   __libc_lock_unlock (lock);
 160
 161   return result;
 162 }
 163
 164
 165 static enum nss_status
 166 internal_endgrent (ent_t *ent)
 167 {
 168   if (nss_endgrent)
 169     nss_endgrent ();
 170
 171   if (ent->stream != NULL)
 172     {
 173       fclose (ent->stream);
 174       ent->stream = NULL;
 175     }
 176
 177   if (ent->blacklist.data != NULL)
 178     {
 179       ent->blacklist.current = 1;
 180       ent->blacklist.data[0] = '|';
 181       ent->blacklist.data[1] = '\0';
 182     }
 183   else
 184     ent->blacklist.current = 0;
 185
 186   return NSS_STATUS_SUCCESS;
 187 }
 188
 189 enum nss_status
 190 _nss_compat_endgrent (void)
 191 {
 192   enum nss_status result;
 193
 194   __libc_lock_lock (lock);
 195
 196   result = internal_endgrent (&ext_ent);
 197
 198   __libc_lock_unlock (lock);
 199
 200   return result;
 201 }
 202
 203 /* get the next group from NSS  (+ entry) */
 204 static enum nss_status
 205 getgrent_next_nss (struct group *result, ent_t *ent, char *buffer,
 206                    size_t buflen, int *errnop)
 207 {
 208   if (!nss_getgrent_r)
 209     return NSS_STATUS_UNAVAIL;
 210
 211   do
 212     {
 213       enum nss_status status;
 214
 215       if ((status = nss_getgrent_r (result, buffer, buflen, errnop)) !=
 216           NSS_STATUS_SUCCESS)
 217         return status;
 218     }
 219   while (in_blacklist (result->gr_name, strlen (result->gr_name), ent));
 220
 221   return NSS_STATUS_SUCCESS;
 222 }
 223
 224 /* This function handle the +group entrys in /etc/group */
 225 static enum nss_status
 226 getgrnam_plusgroup (const char *name, struct group *result, ent_t *ent,
 227                     char *buffer, size_t buflen, int *errnop)
 228 {
 229   if (!nss_getgrnam_r)
 230     return NSS_STATUS_UNAVAIL;
 231
 232   if (nss_getgrnam_r (name, result, buffer, buflen, errnop) !=
 233       NSS_STATUS_SUCCESS)
 234     return NSS_STATUS_NOTFOUND;
 235
 236   if (in_blacklist (result->gr_name, strlen (result->gr_name), ent))
 237     return NSS_STATUS_NOTFOUND;
 238
 239   /* We found the entry.  */
 240   return NSS_STATUS_SUCCESS;
 241 }
 242
 243 static enum nss_status
 244 getgrent_next_file (struct group *result, ent_t *ent,
 245                     char *buffer, size_t buflen, int *errnop)
 246 {
 247   struct parser_data *data = (void *) buffer;
 248   while (1)
 249     {
 250       fpos_t pos;
 251       int parse_res = 0;
 252       char *p;
 253
 254       do
 255         {
 256           fgetpos (ent->stream, &pos);
 257           buffer[buflen - 1] = '\xff';
 258           p = fgets_unlocked (buffer, buflen, ent->stream);
 259           if (p == NULL && feof_unlocked (ent->stream))
 260             return NSS_STATUS_NOTFOUND;
 261
 262           if (p == NULL || buffer[buflen - 1] != '\xff')
 263             {
 264               fsetpos (ent->stream, &pos);
 265               *errnop = ERANGE;
 266               return NSS_STATUS_TRYAGAIN;
 267             }
 268
 269           /* Terminate the line for any case.  */
 270           buffer[buflen - 1] = '\0';
 271
 272           /* Skip leading blanks.  */
 273           while (isspace (*p))
 274             ++p;
 275         }
 276       while (*p == '\0' || *p == '#' || /* Ignore empty and comment lines. */
 277              /* Parse the line.  If it is invalid, loop to
 278                 get the next line of the file to parse.  */
 279              !(parse_res = _nss_files_parse_grent (p, result, data, buflen,
 280                                                    errnop)));
 281
 282       if (parse_res == -1)
 283         {
 284           /* The parser ran out of space.  */
 285           fsetpos (ent->stream, &pos);
 286           *errnop = ERANGE;
 287           return NSS_STATUS_TRYAGAIN;
 288         }
 289
 290       if (result->gr_name[0] != '+' && result->gr_name[0] != '-')
 291         /* This is a real entry.  */
 292         break;
 293
 294       /* -group */
 295       if (result->gr_name[0] == '-' && result->gr_name[1] != '\0'
 296           && result->gr_name[1] != '@')
 297         {
 298           blacklist_store_name (&result->gr_name[1], ent);
 299           continue;
 300         }
 301
 302       /* +group */
 303       if (result->gr_name[0] == '+' && result->gr_name[1] != '\0'
 304           && result->gr_name[1] != '@')
 305         {
 306           size_t len = strlen (result->gr_name);
 307           char buf[len];
 308           enum nss_status status;
 309
 310           /* Store the group in the blacklist for the "+" at the end of
 311              /etc/group */
 312           memcpy (buf, &result->gr_name[1], len);
 313           status = getgrnam_plusgroup (&result->gr_name[1], result, ent,
 314                                        buffer, buflen, errnop);
 315           blacklist_store_name (buf, ent);
 316           if (status == NSS_STATUS_SUCCESS)     /* We found the entry. */
 317             break;
 318           else if (status == NSS_STATUS_RETURN  /* We couldn't parse the entry */
 319                    || status == NSS_STATUS_NOTFOUND)    /* No group in NIS */
 320             continue;
 321           else
 322             {
 323               if (status == NSS_STATUS_TRYAGAIN)
 324                 {
 325                   /* The parser ran out of space.  */
 326                   fsetpos (ent->stream, &pos);
 327                   *errnop = ERANGE;
 328                 }
 329               return status;
 330             }
 331         }
 332
 333       /* +:... */
 334       if (result->gr_name[0] == '+' && result->gr_name[1] == '\0')
 335         {
 336           ent->files = FALSE;
 337
 338           return getgrent_next_nss (result, ent, buffer, buflen, errnop);
 339         }
 340     }
 341
 342   return NSS_STATUS_SUCCESS;
 343 }
 344
 345
 346 enum nss_status
 347 _nss_compat_getgrent_r (struct group *grp, char *buffer, size_t buflen,
 348                         int *errnop)
 349 {
 350   enum nss_status result = NSS_STATUS_SUCCESS;
 351
 352   __libc_lock_lock (lock);
 353
 354   /* Be prepared that the setgrent function was not called before.  */
 355   if (ni == NULL)
 356     init_nss_interface ();
 357
 358   if (ext_ent.stream == NULL)
 359     result = internal_setgrent (&ext_ent, 1);
 360
 361   if (result == NSS_STATUS_SUCCESS)
 362     {
 363       if (ext_ent.files)
 364         result = getgrent_next_file (grp, &ext_ent, buffer, buflen, errnop);
 365       else
 366         result = getgrent_next_nss (grp, &ext_ent, buffer, buflen, errnop);
 367     }
 368   __libc_lock_unlock (lock);
 369
 370   return result;
 371 }
 372
 373 /* Searches in /etc/group and the NIS/NIS+ map for a special group */
 374 static enum nss_status
 375 internal_getgrnam_r (const char *name, struct group *result, ent_t *ent,
 376                      char *buffer, size_t buflen, int *errnop)
 377 {
 378   struct parser_data *data = (void *) buffer;
 379   while (1)
 380     {
 381       fpos_t pos;
 382       int parse_res = 0;
 383       char *p;
 384
 385       do
 386         {
 387           fgetpos (ent->stream, &pos);
 388           buffer[buflen - 1] = '\xff';
 389           p = fgets_unlocked (buffer, buflen, ent->stream);
 390           if (p == NULL && feof_unlocked (ent->stream))
 391             return NSS_STATUS_NOTFOUND;
 392
 393           if (p == NULL || buffer[buflen - 1] != '\xff')
 394             {
 395               fsetpos (ent->stream, &pos);
 396               *errnop = ERANGE;
 397               return NSS_STATUS_TRYAGAIN;
 398             }
 399
 400           /* Terminate the line for any case.  */
 401           buffer[buflen - 1] = '\0';
 402
 403           /* Skip leading blanks.  */
 404           while (isspace (*p))
 405             ++p;
 406         }
 407       while (*p == '\0' || *p == '#' || /* Ignore empty and comment lines. */
 408              /* Parse the line.  If it is invalid, loop to
 409                 get the next line of the file to parse.  */
 410              !(parse_res = _nss_files_parse_grent (p, result, data, buflen,
 411                                                    errnop)));
 412
 413       if (parse_res == -1)
 414         {
 415           /* The parser ran out of space.  */
 416           fsetpos (ent->stream, &pos);
 417           *errnop = ERANGE;
 418           return NSS_STATUS_TRYAGAIN;
 419         }
 420
 421       /* This is a real entry.  */
 422       if (result->gr_name[0] != '+' && result->gr_name[0] != '-')
 423         {
 424           if (strcmp (result->gr_name, name) == 0)
 425             return NSS_STATUS_SUCCESS;
 426           else
 427             continue;
 428         }
 429
 430       /* -group */
 431       if (result->gr_name[0] == '-' && result->gr_name[1] != '\0')
 432         {
 433           if (strcmp (&result->gr_name[1], name) == 0)
 434             return NSS_STATUS_NOTFOUND;
 435           else
 436             continue;
 437         }
 438
 439       /* +group */
 440       if (result->gr_name[0] == '+' && result->gr_name[1] != '\0')
 441         {
 442           if (strcmp (name, &result->gr_name[1]) == 0)
 443             {
 444               enum nss_status status;
 445
 446               status = getgrnam_plusgroup (name, result, ent,
 447                                            buffer, buflen, errnop);
 448               if (status == NSS_STATUS_RETURN)
 449                 /* We couldn't parse the entry */
 450                 continue;
 451               else
 452                 return status;
 453             }
 454         }
 455       /* +:... */
 456       if (result->gr_name[0] == '+' && result->gr_name[1] == '\0')
 457         {
 458           enum nss_status status;
 459
 460           status = getgrnam_plusgroup (name, result, ent,
 461                                        buffer, buflen, errnop);
 462           if (status == NSS_STATUS_RETURN)
 463             /* We couldn't parse the entry */
 464             continue;
 465           else
 466             return status;
 467         }
 468     }
 469
 470   return NSS_STATUS_SUCCESS;
 471 }
 472
 473 enum nss_status
 474 _nss_compat_getgrnam_r (const char *name, struct group *grp,
 475                         char *buffer, size_t buflen, int *errnop)
 476 {
 477   ent_t ent = {TRUE, NULL, {NULL, 0, 0}};
 478   enum nss_status result;
 479
 480   if (name[0] == '-' || name[0] == '+')
 481     return NSS_STATUS_NOTFOUND;
 482
 483   __libc_lock_lock (lock);
 484
 485   if (ni == NULL)
 486     init_nss_interface ();
 487
 488   __libc_lock_unlock (lock);
 489
 490   result = internal_setgrent (&ent, 0);
 491
 492   if (result == NSS_STATUS_SUCCESS)
 493     result = internal_getgrnam_r (name, grp, &ent, buffer, buflen, errnop);
 494
 495   internal_endgrent (&ent);
 496
 497   return result;
 498 }
 499
 500 /* Searches in /etc/group and the NIS/NIS+ map for a special group id */
 501 static enum nss_status
 502 internal_getgrgid_r (gid_t gid, struct group *result, ent_t *ent,
 503                      char *buffer, size_t buflen, int *errnop)
 504 {
 505   struct parser_data *data = (void *) buffer;
 506   while (1)
 507     {
 508       fpos_t pos;
 509       int parse_res = 0;
 510       char *p;
 511
 512       do
 513         {
 514           fgetpos (ent->stream, &pos);
 515           buffer[buflen - 1] = '\xff';
 516           p = fgets_unlocked (buffer, buflen, ent->stream);
 517           if (p == NULL && feof_unlocked (ent->stream))
 518             return NSS_STATUS_NOTFOUND;
 519
 520           if (p == NULL || buffer[buflen - 1] != '\xff')
 521             {
 522               fsetpos (ent->stream, &pos);
 523               *errnop = ERANGE;
 524               return NSS_STATUS_TRYAGAIN;
 525             }
 526
 527           /* Terminate the line for any case.  */
 528           buffer[buflen - 1] = '\0';
 529
 530           /* Skip leading blanks.  */
 531           while (isspace (*p))
 532             ++p;
 533         }
 534       while (*p == '\0' || *p == '#' || /* Ignore empty and comment lines. */
 535              /* Parse the line.  If it is invalid, loop to
 536                 get the next line of the file to parse.  */
 537              !(parse_res = _nss_files_parse_grent (p, result, data, buflen,
 538                                                    errnop)));
 539
 540       if (parse_res == -1)
 541         {
 542           /* The parser ran out of space.  */
 543           fsetpos (ent->stream, &pos);
 544           *errnop = ERANGE;
 545           return NSS_STATUS_TRYAGAIN;
 546         }
 547
 548       /* This is a real entry.  */
 549       if (result->gr_name[0] != '+' && result->gr_name[0] != '-')
 550         {
 551           if (result->gr_gid == gid)
 552             return NSS_STATUS_SUCCESS;
 553           else
 554             continue;
 555         }
 556
 557       /* -group */
 558       if (result->gr_name[0] == '-' && result->gr_name[1] != '\0')
 559         {
 560           blacklist_store_name (&result->gr_name[1], ent);
 561           continue;
 562         }
 563
 564       /* +group */
 565       if (result->gr_name[0] == '+' && result->gr_name[1] != '\0')
 566         {
 567           enum nss_status status;
 568
 569           /* Store the group in the blacklist for the "+" at the end of
 570              /etc/group */
 571           blacklist_store_name (&result->gr_name[1], ent);
 572           status = getgrnam_plusgroup (&result->gr_name[1], result, ent,
 573                                        buffer, buflen, errnop);
 574           if (status == NSS_STATUS_SUCCESS && result->gr_gid == gid)
 575             break;
 576           else
 577             continue;
 578         }
 579       /* +:... */
 580       if (result->gr_name[0] == '+' && result->gr_name[1] == '\0')
 581         {
 582           enum nss_status status;
 583
 584           status = nss_getgrgid_r (gid, result, buffer, buflen, errnop);
 585           if (status == NSS_STATUS_RETURN) /* We couldn't parse the entry */
 586             return NSS_STATUS_NOTFOUND;
 587           else
 588             return status;
 589         }
 590     }
 591
 592   return NSS_STATUS_SUCCESS;
 593 }
 594
 595 enum nss_status
 596 _nss_compat_getgrgid_r (gid_t gid, struct group *grp,
 597                         char *buffer, size_t buflen, int *errnop)
 598 {
 599   ent_t ent = {TRUE, NULL, {NULL, 0, 0}};
 600   enum nss_status result;
 601
 602   __libc_lock_lock (lock);
 603
 604   if (ni == NULL)
 605     init_nss_interface ();
 606
 607   __libc_lock_unlock (lock);
 608
 609   result = internal_setgrent (&ent, 0);
 610
 611   if (result == NSS_STATUS_SUCCESS)
 612     result = internal_getgrgid_r (gid, grp, &ent, buffer, buflen, errnop);
 613
 614   internal_endgrent (&ent);
 615
 616   return result;
 617 }
 618
 619
 620 /* Support routines for remembering -@netgroup and -user entries.
 621    The names are stored in a single string with `|' as separator. */
 622 static void
 623 blacklist_store_name (const char *name, ent_t *ent)
 624 {
 625   int namelen = strlen (name);
 626   char *tmp;
 627
 628   /* first call, setup cache */
 629   if (ent->blacklist.size == 0)
 630     {
 631       ent->blacklist.size = MAX (BLACKLIST_INITIAL_SIZE, 2 * namelen);
 632       ent->blacklist.data = malloc (ent->blacklist.size);
 633       if (ent->blacklist.data == NULL)
 634         return;
 635       ent->blacklist.data[0] = '|';
 636       ent->blacklist.data[1] = '\0';
 637       ent->blacklist.current = 1;
 638     }
 639   else
 640     {
 641       if (in_blacklist (name, namelen, ent))
 642         return;                 /* no duplicates */
 643
 644       if (ent->blacklist.current + namelen + 1 >= ent->blacklist.size)
 645         {
 646           ent->blacklist.size += MAX (BLACKLIST_INCREMENT, 2 * namelen);
 647           tmp = realloc (ent->blacklist.data, ent->blacklist.size);
 648           if (tmp == NULL)
 649             {
 650               free (ent->blacklist.data);
 651               ent->blacklist.size = 0;
 652               return;
 653             }
 654           ent->blacklist.data = tmp;
 655         }
 656     }
 657
 658   tmp = stpcpy (ent->blacklist.data + ent->blacklist.current, name);
 659   *tmp++ = '|';
 660   *tmp = '\0';
 661   ent->blacklist.current += namelen + 1;
 662
 663   return;
 664 }
 665
 666 /* returns TRUE if ent->blacklist contains name, else FALSE */
 667 static bool_t
 668 in_blacklist (const char *name, int namelen, ent_t *ent)
 669 {
 670   char buf[namelen + 3];
 671   char *cp;
 672
 673   if (ent->blacklist.data == NULL)
 674     return FALSE;
 675
 676   buf[0] = '|';
 677   cp = stpcpy (&buf[1], name);
 678   *cp++ = '|';
 679   *cp = '\0';
 680   return strstr (ent->blacklist.data, buf) != NULL;
 681 }