nis/nss_compat/compat-grp.c

   1 /* Copyright (C) 1996-1999,2001,2002,2003,2004 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           /* We need at least 3 characters for one line.  */
 257           if (__builtin_expect (buflen < 3, 0))
 258             {
 259             erange:
 260               *errnop = ERANGE;
 261               return NSS_STATUS_TRYAGAIN;
 262             }
 263
 264           fgetpos (ent->stream, &pos);
 265           buffer[buflen - 1] = '\xff';
 266           p = fgets_unlocked (buffer, buflen, ent->stream);
 267           if (p == NULL && feof_unlocked (ent->stream))
 268             return NSS_STATUS_NOTFOUND;
 269
 270           if (p == NULL || __builtin_expect (buffer[buflen - 1] != '\xff', 0))
 271             {
 272             erange_reset:
 273               fsetpos (ent->stream, &pos);
 274               goto erange;
 275             }
 276
 277           /* Terminate the line for any case.  */
 278           buffer[buflen - 1] = '\0';
 279
 280           /* Skip leading blanks.  */
 281           while (isspace (*p))
 282             ++p;
 283         }
 284       while (*p == '\0' || *p == '#' || /* Ignore empty and comment lines. */
 285              /* Parse the line.  If it is invalid, loop to
 286                 get the next line of the file to parse.  */
 287              !(parse_res = _nss_files_parse_grent (p, result, data, buflen,
 288                                                    errnop)));
 289
 290       if (__builtin_expect (parse_res == -1, 0))
 291         /* The parser ran out of space.  */
 292         goto erange_reset;
 293
 294       if (result->gr_name[0] != '+' && result->gr_name[0] != '-')
 295         /* This is a real entry.  */
 296         break;
 297
 298       /* -group */
 299       if (result->gr_name[0] == '-' && result->gr_name[1] != '\0'
 300           && result->gr_name[1] != '@')
 301         {
 302           blacklist_store_name (&result->gr_name[1], ent);
 303           continue;
 304         }
 305
 306       /* +group */
 307       if (result->gr_name[0] == '+' && result->gr_name[1] != '\0'
 308           && result->gr_name[1] != '@')
 309         {
 310           size_t len = strlen (result->gr_name);
 311           char buf[len];
 312           enum nss_status status;
 313
 314           /* Store the group in the blacklist for the "+" at the end of
 315              /etc/group */
 316           memcpy (buf, &result->gr_name[1], len);
 317           status = getgrnam_plusgroup (&result->gr_name[1], result, ent,
 318                                        buffer, buflen, errnop);
 319           blacklist_store_name (buf, ent);
 320           if (status == NSS_STATUS_SUCCESS)     /* We found the entry. */
 321             break;
 322           else if (status == NSS_STATUS_RETURN /* We couldn't parse the entry*/
 323                    || status == NSS_STATUS_NOTFOUND)    /* No group in NIS */
 324             continue;
 325           else
 326             {
 327               if (status == NSS_STATUS_TRYAGAIN)
 328                 /* The parser ran out of space.  */
 329                 goto erange_reset;
 330
 331               return status;
 332             }
 333         }
 334
 335       /* +:... */
 336       if (result->gr_name[0] == '+' && result->gr_name[1] == '\0')
 337         {
 338           ent->files = FALSE;
 339
 340           return getgrent_next_nss (result, ent, buffer, buflen, errnop);
 341         }
 342     }
 343
 344   return NSS_STATUS_SUCCESS;
 345 }
 346
 347
 348 enum nss_status
 349 _nss_compat_getgrent_r (struct group *grp, char *buffer, size_t buflen,
 350                         int *errnop)
 351 {
 352   enum nss_status result = NSS_STATUS_SUCCESS;
 353
 354   __libc_lock_lock (lock);
 355
 356   /* Be prepared that the setgrent function was not called before.  */
 357   if (ni == NULL)
 358     init_nss_interface ();
 359
 360   if (ext_ent.stream == NULL)
 361     result = internal_setgrent (&ext_ent, 1);
 362
 363   if (result == NSS_STATUS_SUCCESS)
 364     {
 365       if (ext_ent.files)
 366         result = getgrent_next_file (grp, &ext_ent, buffer, buflen, errnop);
 367       else
 368         result = getgrent_next_nss (grp, &ext_ent, buffer, buflen, errnop);
 369     }
 370   __libc_lock_unlock (lock);
 371
 372   return result;
 373 }
 374
 375 /* Searches in /etc/group and the NIS/NIS+ map for a special group */
 376 static enum nss_status
 377 internal_getgrnam_r (const char *name, struct group *result, ent_t *ent,
 378                      char *buffer, size_t buflen, int *errnop)
 379 {
 380   struct parser_data *data = (void *) buffer;
 381   while (1)
 382     {
 383       fpos_t pos;
 384       int parse_res = 0;
 385       char *p;
 386
 387       do
 388         {
 389           /* We need at least 3 characters for one line.  */
 390           if (__builtin_expect (buflen < 3, 0))
 391             {
 392             erange:
 393               *errnop = ERANGE;
 394               return NSS_STATUS_TRYAGAIN;
 395             }
 396
 397           fgetpos (ent->stream, &pos);
 398           buffer[buflen - 1] = '\xff';
 399           p = fgets_unlocked (buffer, buflen, ent->stream);
 400           if (p == NULL && feof_unlocked (ent->stream))
 401             return NSS_STATUS_NOTFOUND;
 402
 403           if (p == NULL || __builtin_expect (buffer[buflen - 1] != '\xff', 0))
 404             {
 405             erange_reset:
 406               fsetpos (ent->stream, &pos);
 407               goto erange;
 408             }
 409
 410           /* Terminate the line for any case.  */
 411           buffer[buflen - 1] = '\0';
 412
 413           /* Skip leading blanks.  */
 414           while (isspace (*p))
 415             ++p;
 416         }
 417       while (*p == '\0' || *p == '#' || /* Ignore empty and comment lines. */
 418              /* Parse the line.  If it is invalid, loop to
 419                 get the next line of the file to parse.  */
 420              !(parse_res = _nss_files_parse_grent (p, result, data, buflen,
 421                                                    errnop)));
 422
 423       if (__builtin_expect (parse_res == -1, 0))
 424         /* The parser ran out of space.  */
 425         goto erange_reset;
 426
 427       /* This is a real entry.  */
 428       if (result->gr_name[0] != '+' && result->gr_name[0] != '-')
 429         {
 430           if (strcmp (result->gr_name, name) == 0)
 431             return NSS_STATUS_SUCCESS;
 432           else
 433             continue;
 434         }
 435
 436       /* -group */
 437       if (result->gr_name[0] == '-' && result->gr_name[1] != '\0')
 438         {
 439           if (strcmp (&result->gr_name[1], name) == 0)
 440             return NSS_STATUS_NOTFOUND;
 441           else
 442             continue;
 443         }
 444
 445       /* +group */
 446       if (result->gr_name[0] == '+' && result->gr_name[1] != '\0')
 447         {
 448           if (strcmp (name, &result->gr_name[1]) == 0)
 449             {
 450               enum nss_status status;
 451
 452               status = getgrnam_plusgroup (name, result, ent,
 453                                            buffer, buflen, errnop);
 454               if (status == NSS_STATUS_RETURN)
 455                 /* We couldn't parse the entry */
 456                 continue;
 457               else
 458                 return status;
 459             }
 460         }
 461       /* +:... */
 462       if (result->gr_name[0] == '+' && result->gr_name[1] == '\0')
 463         {
 464           enum nss_status status;
 465
 466           status = getgrnam_plusgroup (name, result, ent,
 467                                        buffer, buflen, errnop);
 468           if (status == NSS_STATUS_RETURN)
 469             /* We couldn't parse the entry */
 470             continue;
 471           else
 472             return status;
 473         }
 474     }
 475
 476   return NSS_STATUS_SUCCESS;
 477 }
 478
 479 enum nss_status
 480 _nss_compat_getgrnam_r (const char *name, struct group *grp,
 481                         char *buffer, size_t buflen, int *errnop)
 482 {
 483   ent_t ent = {TRUE, NULL, {NULL, 0, 0}};
 484   enum nss_status result;
 485
 486   if (name[0] == '-' || name[0] == '+')
 487     return NSS_STATUS_NOTFOUND;
 488
 489   __libc_lock_lock (lock);
 490
 491   if (ni == NULL)
 492     init_nss_interface ();
 493
 494   __libc_lock_unlock (lock);
 495
 496   result = internal_setgrent (&ent, 0);
 497
 498   if (result == NSS_STATUS_SUCCESS)
 499     result = internal_getgrnam_r (name, grp, &ent, buffer, buflen, errnop);
 500
 501   internal_endgrent (&ent);
 502
 503   return result;
 504 }
 505
 506 /* Searches in /etc/group and the NIS/NIS+ map for a special group id */
 507 static enum nss_status
 508 internal_getgrgid_r (gid_t gid, struct group *result, ent_t *ent,
 509                      char *buffer, size_t buflen, int *errnop)
 510 {
 511   struct parser_data *data = (void *) buffer;
 512   while (1)
 513     {
 514       fpos_t pos;
 515       int parse_res = 0;
 516       char *p;
 517
 518       do
 519         {
 520           /* We need at least 3 characters for one line.  */
 521           if (__builtin_expect (buflen < 3, 0))
 522             {
 523             erange:
 524               *errnop = ERANGE;
 525               return NSS_STATUS_TRYAGAIN;
 526             }
 527
 528           fgetpos (ent->stream, &pos);
 529           buffer[buflen - 1] = '\xff';
 530           p = fgets_unlocked (buffer, buflen, ent->stream);
 531           if (p == NULL && feof_unlocked (ent->stream))
 532             return NSS_STATUS_NOTFOUND;
 533
 534           if (p == NULL || __builtin_expect (buffer[buflen - 1] != '\xff', 0))
 535             {
 536             erange_reset:
 537               fsetpos (ent->stream, &pos);
 538               goto erange;
 539             }
 540
 541           /* Terminate the line for any case.  */
 542           buffer[buflen - 1] = '\0';
 543
 544           /* Skip leading blanks.  */
 545           while (isspace (*p))
 546             ++p;
 547         }
 548       while (*p == '\0' || *p == '#' || /* Ignore empty and comment lines. */
 549              /* Parse the line.  If it is invalid, loop to
 550                 get the next line of the file to parse.  */
 551              !(parse_res = _nss_files_parse_grent (p, result, data, buflen,
 552                                                    errnop)));
 553
 554       if (parse_res == -1)
 555         /* The parser ran out of space.  */
 556         goto erange_reset;
 557
 558       /* This is a real entry.  */
 559       if (result->gr_name[0] != '+' && result->gr_name[0] != '-')
 560         {
 561           if (result->gr_gid == gid)
 562             return NSS_STATUS_SUCCESS;
 563           else
 564             continue;
 565         }
 566
 567       /* -group */
 568       if (result->gr_name[0] == '-' && result->gr_name[1] != '\0')
 569         {
 570           blacklist_store_name (&result->gr_name[1], ent);
 571           continue;
 572         }
 573
 574       /* +group */
 575       if (result->gr_name[0] == '+' && result->gr_name[1] != '\0')
 576         {
 577           enum nss_status status;
 578
 579           /* Store the group in the blacklist for the "+" at the end of
 580              /etc/group */
 581           blacklist_store_name (&result->gr_name[1], ent);
 582           status = getgrnam_plusgroup (&result->gr_name[1], result, ent,
 583                                        buffer, buflen, errnop);
 584           if (status == NSS_STATUS_SUCCESS && result->gr_gid == gid)
 585             break;
 586           else
 587             continue;
 588         }
 589       /* +:... */
 590       if (result->gr_name[0] == '+' && result->gr_name[1] == '\0')
 591         {
 592           enum nss_status status;
 593
 594           status = nss_getgrgid_r (gid, result, buffer, buflen, errnop);
 595           if (status == NSS_STATUS_RETURN) /* We couldn't parse the entry */
 596             return NSS_STATUS_NOTFOUND;
 597           else
 598             return status;
 599         }
 600     }
 601
 602   return NSS_STATUS_SUCCESS;
 603 }
 604
 605 enum nss_status
 606 _nss_compat_getgrgid_r (gid_t gid, struct group *grp,
 607                         char *buffer, size_t buflen, int *errnop)
 608 {
 609   ent_t ent = {TRUE, NULL, {NULL, 0, 0}};
 610   enum nss_status result;
 611
 612   __libc_lock_lock (lock);
 613
 614   if (ni == NULL)
 615     init_nss_interface ();
 616
 617   __libc_lock_unlock (lock);
 618
 619   result = internal_setgrent (&ent, 0);
 620
 621   if (result == NSS_STATUS_SUCCESS)
 622     result = internal_getgrgid_r (gid, grp, &ent, buffer, buflen, errnop);
 623
 624   internal_endgrent (&ent);
 625
 626   return result;
 627 }
 628
 629
 630 /* Support routines for remembering -@netgroup and -user entries.
 631    The names are stored in a single string with `|' as separator. */
 632 static void
 633 blacklist_store_name (const char *name, ent_t *ent)
 634 {
 635   int namelen = strlen (name);
 636   char *tmp;
 637
 638   /* first call, setup cache */
 639   if (ent->blacklist.size == 0)
 640     {
 641       ent->blacklist.size = MAX (BLACKLIST_INITIAL_SIZE, 2 * namelen);
 642       ent->blacklist.data = malloc (ent->blacklist.size);
 643       if (ent->blacklist.data == NULL)
 644         return;
 645       ent->blacklist.data[0] = '|';
 646       ent->blacklist.data[1] = '\0';
 647       ent->blacklist.current = 1;
 648     }
 649   else
 650     {
 651       if (in_blacklist (name, namelen, ent))
 652         return;                 /* no duplicates */
 653
 654       if (ent->blacklist.current + namelen + 1 >= ent->blacklist.size)
 655         {
 656           ent->blacklist.size += MAX (BLACKLIST_INCREMENT, 2 * namelen);
 657           tmp = realloc (ent->blacklist.data, ent->blacklist.size);
 658           if (tmp == NULL)
 659             {
 660               free (ent->blacklist.data);
 661               ent->blacklist.size = 0;
 662               return;
 663             }
 664           ent->blacklist.data = tmp;
 665         }
 666     }
 667
 668   tmp = stpcpy (ent->blacklist.data + ent->blacklist.current, name);
 669   *tmp++ = '|';
 670   *tmp = '\0';
 671   ent->blacklist.current += namelen + 1;
 672
 673   return;
 674 }
 675
 676 /* returns TRUE if ent->blacklist contains name, else FALSE */
 677 static bool_t
 678 in_blacklist (const char *name, int namelen, ent_t *ent)
 679 {
 680   char buf[namelen + 3];
 681   char *cp;
 682
 683   if (ent->blacklist.data == NULL)
 684     return FALSE;
 685
 686   buf[0] = '|';
 687   cp = stpcpy (&buf[1], name);
 688   *cp++ = '|';
 689   *cp = '\0';
 690   return strstr (ent->blacklist.data, buf) != NULL;
 691 }