nis/nss_nis/nis-pwd.c

   1 /* Copyright (C) 1996-2017 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Thorsten Kukuk <kukuk@vt.uni-paderborn.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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <assert.h>
  20 #include <ctype.h>
  21 #include <errno.h>
  22 #include <nss.h>
  23 #include <pwd.h>
  24 #include <string.h>
  25 #include <libc-lock.h>
  26 #include <rpcsvc/yp.h>
  27 #include <rpcsvc/ypclnt.h>
  28
  29 #include "nss-nis.h"
  30 #include <libnsl.h>
  31
  32 /* Get the declaration of the parser function.  */
  33 #define ENTNAME pwent
  34 #define STRUCTURE passwd
  35 #define EXTERN_PARSER
  36 #include <nss/nss_files/files-parse.c>
  37
  38 /* Protect global state against multiple changers */
  39 __libc_lock_define_initialized (static, lock)
  40
  41 static bool new_start = true;
  42 static char *oldkey;
  43 static int oldkeylen;
  44 static intern_t intern;
  45
  46
  47 int
  48 _nis_saveit (int instatus, char *inkey, int inkeylen, char *inval,
  49              int invallen, char *indata)
  50 {
  51   intern_t *intern = (intern_t *) indata;
  52
  53   if (instatus != YP_TRUE)
  54     return 1;
  55
  56   if (inkey && inkeylen > 0 && inval && invallen > 0)
  57     {
  58       struct response_t *bucket = intern->next;
  59
  60       if (__glibc_unlikely (bucket == NULL))
  61         {
  62 #define MINSIZE 4096 - 4 * sizeof (void *)
  63           const size_t minsize = MAX (MINSIZE, 2 * (invallen + 1));
  64           bucket = malloc (sizeof (struct response_t) + minsize);
  65           if (bucket == NULL)
  66             /* We have no error code for out of memory.  */
  67             return 1;
  68
  69           bucket->next = NULL;
  70           bucket->size = minsize;
  71           intern->start = intern->next = bucket;
  72           intern->offset = 0;
  73         }
  74       else if (__builtin_expect (invallen + 1 > bucket->size - intern->offset,
  75                                  0))
  76         {
  77           /* We need a new (larger) buffer.  */
  78           const size_t newsize = 2 * MAX (bucket->size, invallen + 1);
  79           struct response_t *newp = malloc (sizeof (struct response_t)
  80                                             + newsize);
  81           if (newp == NULL)
  82             /* We have no error code for out of memory.  */
  83             return 1;
  84
  85           /* Mark the old bucket as full.  */
  86           bucket->size = intern->offset;
  87
  88           newp->next = NULL;
  89           newp->size = newsize;
  90           bucket = intern->next = bucket->next = newp;
  91           intern->offset = 0;
  92         }
  93
  94       char *p = mempcpy (&bucket->mem[intern->offset], inval, invallen);
  95       if (__glibc_unlikely (p[-1] != '\0'))
  96         {
  97           *p = '\0';
  98           ++invallen;
  99         }
 100       intern->offset += invallen;
 101     }
 102
 103   return 0;
 104 }
 105
 106
 107 static void
 108 internal_nis_endpwent (void)
 109 {
 110   new_start = true;
 111   free (oldkey);
 112   oldkey = NULL;
 113   oldkeylen = 0;
 114
 115   struct response_t *curr = intern.start;
 116
 117   while (curr != NULL)
 118     {
 119       struct response_t *last = curr;
 120       curr = curr->next;
 121       free (last);
 122     }
 123
 124   intern.next = intern.start = NULL;
 125 }
 126
 127
 128 enum nss_status
 129 _nss_nis_endpwent (void)
 130 {
 131   __libc_lock_lock (lock);
 132
 133   internal_nis_endpwent ();
 134
 135   __libc_lock_unlock (lock);
 136
 137   return NSS_STATUS_SUCCESS;
 138 }
 139
 140
 141 enum nss_status
 142 internal_nis_setpwent (void)
 143 {
 144   /* We have to read all the data now.  */
 145   char *domain;
 146   if (__glibc_unlikely (yp_get_default_domain (&domain)))
 147     return NSS_STATUS_UNAVAIL;
 148
 149   struct ypall_callback ypcb;
 150
 151   ypcb.foreach = _nis_saveit;
 152   ypcb.data = (char *) &intern;
 153   enum nss_status status = yperr2nss (yp_all (domain, "passwd.byname", &ypcb));
 154
 155
 156   /* Mark the last buffer as full.  */
 157   if (intern.next != NULL)
 158     intern.next->size = intern.offset;
 159
 160   intern.next = intern.start;
 161   intern.offset = 0;
 162
 163   return status;
 164 }
 165
 166
 167 enum nss_status
 168 _nss_nis_setpwent (int stayopen)
 169 {
 170   enum nss_status result = NSS_STATUS_SUCCESS;
 171
 172   __libc_lock_lock (lock);
 173
 174   internal_nis_endpwent ();
 175
 176   if (_nsl_default_nss () & NSS_FLAG_SETENT_BATCH_READ)
 177     result = internal_nis_setpwent ();
 178
 179   __libc_lock_unlock (lock);
 180
 181   return result;
 182 }
 183
 184
 185 static enum nss_status
 186 internal_nis_getpwent_r (struct passwd *pwd, char *buffer, size_t buflen,
 187                          int *errnop)
 188 {
 189   /* If we read the entire database at setpwent time we just iterate
 190      over the data we have in memory.  */
 191   bool batch_read = intern.start != NULL;
 192
 193   char *domain = NULL;
 194   if (!batch_read && __builtin_expect (yp_get_default_domain (&domain), 0))
 195     return NSS_STATUS_UNAVAIL;
 196
 197   /* Get the next entry until we found a correct one. */
 198   int parse_res;
 199   do
 200     {
 201       char *result;
 202       char *outkey;
 203       int len;
 204       int keylen;
 205
 206       if (batch_read)
 207         {
 208           struct response_t *bucket;
 209
 210         handle_batch_read:
 211           bucket = intern.next;
 212
 213           if (__glibc_unlikely (intern.offset >= bucket->size))
 214             {
 215               if (bucket->next == NULL)
 216                 return NSS_STATUS_NOTFOUND;
 217
 218               /* We look at all the content in the current bucket.  Go on
 219                  to the next.  */
 220               bucket = intern.next = bucket->next;
 221               intern.offset = 0;
 222             }
 223
 224           for (result = &bucket->mem[intern.offset]; isspace (*result);
 225                ++result)
 226             ++intern.offset;
 227
 228           len = strlen (result);
 229         }
 230       else
 231         {
 232           int yperr;
 233
 234           if (new_start)
 235             {
 236               /* Maybe we should read the database in one piece.  */
 237               if ((_nsl_default_nss () & NSS_FLAG_SETENT_BATCH_READ)
 238                   && internal_nis_setpwent () == NSS_STATUS_SUCCESS
 239                   && intern.start != NULL)
 240                 {
 241                   batch_read = true;
 242                   goto handle_batch_read;
 243                 }
 244
 245               yperr = yp_first (domain, "passwd.byname", &outkey, &keylen,
 246                                 &result, &len);
 247             }
 248           else
 249             yperr = yp_next (domain, "passwd.byname", oldkey, oldkeylen,
 250                              &outkey, &keylen, &result, &len);
 251
 252           if (__glibc_unlikely (yperr != YPERR_SUCCESS))
 253             {
 254               enum nss_status retval = yperr2nss (yperr);
 255
 256               if (retval == NSS_STATUS_TRYAGAIN)
 257                 *errnop = errno;
 258               return retval;
 259             }
 260         }
 261
 262       /* Check for adjunct style secret passwords.  They can be
 263          recognized by a password starting with "##".  We do not use
 264          it if the passwd.adjunct.byname table is supposed to be used
 265          as a shadow.byname replacement.  */
 266       char *p = strchr (result, ':');
 267       size_t namelen;
 268       char *result2;
 269       int len2;
 270       if ((_nsl_default_nss () & NSS_FLAG_ADJUNCT_AS_SHADOW) == 0
 271           && p != NULL  /* This better should be true in all cases.  */
 272           && p[1] == '#' && p[2] == '#'
 273           && (namelen = p - result,
 274               yp_match (domain, "passwd.adjunct.byname", result, namelen,
 275                         &result2, &len2)) == YPERR_SUCCESS)
 276         {
 277           /* We found a passwd.adjunct.byname entry.  Merge encrypted
 278              password therein into original result.  */
 279           char *encrypted = strchr (result2, ':');
 280           char *endp;
 281           size_t restlen;
 282
 283           if (encrypted == NULL
 284               || (endp = strchr (++encrypted, ':')) == NULL
 285               || (p = strchr (p + 1, ':')) == NULL)
 286             {
 287               /* Invalid format of the entry.  This never should happen
 288                  unless the data from which the NIS table is generated is
 289                  wrong.  We simply ignore it.  */
 290               free (result2);
 291               goto non_adjunct;
 292             }
 293
 294           restlen = len - (p - result);
 295           if (__builtin_expect ((size_t) (namelen + (endp - encrypted)
 296                                           + restlen + 2) > buflen, 0))
 297             {
 298               free (result2);
 299               free (result);
 300               *errnop = ERANGE;
 301               return NSS_STATUS_TRYAGAIN;
 302             }
 303
 304           mempcpy (mempcpy (mempcpy (mempcpy (buffer, result, namelen),
 305                                      ":", 1),
 306                             encrypted, endp - encrypted),
 307                    p, restlen + 1);
 308           p = buffer;
 309
 310           free (result2);
 311         }
 312       else
 313         {
 314         non_adjunct:
 315           if (__glibc_unlikely ((size_t) (len + 1) > buflen))
 316             {
 317               free (result);
 318               *errnop = ERANGE;
 319               return NSS_STATUS_TRYAGAIN;
 320             }
 321
 322           p = buffer;
 323           *((char *) mempcpy (buffer, result, len)) = '\0';
 324         }
 325
 326       while (isspace (*p))
 327         ++p;
 328       if (!batch_read)
 329         free (result);
 330
 331       parse_res = _nss_files_parse_pwent (p, pwd, (void *) buffer, buflen,
 332                                           errnop);
 333       if (__glibc_unlikely (parse_res == -1))
 334         {
 335           if (!batch_read)
 336             free (outkey);
 337           *errnop = ERANGE;
 338           return NSS_STATUS_TRYAGAIN;
 339         }
 340
 341       if (batch_read)
 342         intern.offset += len + 1;
 343       else
 344         {
 345           free (oldkey);
 346           oldkey = outkey;
 347           oldkeylen = keylen;
 348           new_start = false;
 349         }
 350     }
 351   while (parse_res < 1);
 352
 353   return NSS_STATUS_SUCCESS;
 354 }
 355
 356 enum nss_status
 357 _nss_nis_getpwent_r (struct passwd *result, char *buffer, size_t buflen,
 358                      int *errnop)
 359 {
 360   int status;
 361
 362   __libc_lock_lock (lock);
 363
 364   status = internal_nis_getpwent_r (result, buffer, buflen, errnop);
 365
 366   __libc_lock_unlock (lock);
 367
 368   return status;
 369 }
 370
 371 enum nss_status
 372 _nss_nis_getpwnam_r (const char *name, struct passwd *pwd,
 373                      char *buffer, size_t buflen, int *errnop)
 374 {
 375   if (name == NULL)
 376     {
 377       *errnop = EINVAL;
 378       return NSS_STATUS_UNAVAIL;
 379     }
 380
 381   char *domain;
 382   if (__glibc_unlikely (yp_get_default_domain (&domain)))
 383     return NSS_STATUS_UNAVAIL;
 384
 385   size_t namelen = strlen (name);
 386
 387   char *result;
 388   int len;
 389   int yperr = yp_match (domain, "passwd.byname", name, namelen, &result, &len);
 390
 391   if (__glibc_unlikely (yperr != YPERR_SUCCESS))
 392     {
 393       enum nss_status retval = yperr2nss (yperr);
 394
 395       if (retval == NSS_STATUS_TRYAGAIN)
 396         *errnop = errno;
 397       return retval;
 398     }
 399
 400   /* Check for adjunct style secret passwords.  They can be recognized
 401      by a password starting with "##". We do not use it if the
 402      passwd.adjunct.byname table is supposed to be used as a shadow.byname
 403      replacement.  */
 404   char *result2;
 405   int len2;
 406   char *p = strchr (result, ':');
 407   if ((_nsl_default_nss () & NSS_FLAG_ADJUNCT_AS_SHADOW) == 0
 408       && p != NULL      /* This better should be true in all cases.  */
 409       && p[1] == '#' && p[2] == '#'
 410       && yp_match (domain, "passwd.adjunct.byname", name, namelen,
 411                    &result2, &len2) == YPERR_SUCCESS)
 412     {
 413       /* We found a passwd.adjunct.byname entry.  Merge encrypted password
 414          therein into original result.  */
 415       char *encrypted = strchr (result2, ':');
 416       char *endp;
 417
 418       if (encrypted == NULL
 419           || (endp = strchr (++encrypted, ':')) == NULL
 420           || (p = strchr (p + 1, ':')) == NULL)
 421         {
 422           /* Invalid format of the entry.  This never should happen
 423              unless the data from which the NIS table is generated is
 424              wrong.  We simply ignore it.  */
 425           free (result2);
 426           goto non_adjunct;
 427         }
 428
 429       size_t restlen = len - (p - result);
 430       if (__builtin_expect ((size_t) (namelen + (endp - encrypted)
 431                                       + restlen + 2) > buflen, 0))
 432         {
 433           free (result2);
 434           free (result);
 435           *errnop = ERANGE;
 436           return NSS_STATUS_TRYAGAIN;
 437         }
 438
 439       __mempcpy (__mempcpy (__mempcpy (__mempcpy (buffer, name, namelen),
 440                                        ":", 1),
 441                             encrypted, endp - encrypted),
 442                  p, restlen + 1);
 443       p = buffer;
 444
 445       free (result2);
 446     }
 447   else
 448     {
 449     non_adjunct:
 450       if (__glibc_unlikely ((size_t) (len + 1) > buflen))
 451         {
 452           free (result);
 453           *errnop = ERANGE;
 454           return NSS_STATUS_TRYAGAIN;
 455         }
 456
 457       p = strncpy (buffer, result, len);
 458       buffer[len] = '\0';
 459     }
 460
 461   while (isspace (*p))
 462     ++p;
 463   free (result);
 464
 465   int parse_res = _nss_files_parse_pwent (p, pwd, (void *) buffer, buflen,
 466                                           errnop);
 467   if (__glibc_unlikely (parse_res < 1))
 468     {
 469       if (parse_res == -1)
 470         return NSS_STATUS_TRYAGAIN;
 471       else
 472         return NSS_STATUS_NOTFOUND;
 473     }
 474   else
 475     return NSS_STATUS_SUCCESS;
 476 }
 477
 478 enum nss_status
 479 _nss_nis_getpwuid_r (uid_t uid, struct passwd *pwd,
 480                      char *buffer, size_t buflen, int *errnop)
 481 {
 482   char *domain;
 483   if (__glibc_unlikely (yp_get_default_domain (&domain)))
 484     return NSS_STATUS_UNAVAIL;
 485
 486   char buf[32];
 487   int nlen = snprintf (buf, sizeof (buf), "%lu", (unsigned long int) uid);
 488
 489   char *result;
 490   int len;
 491   int yperr = yp_match (domain, "passwd.byuid", buf, nlen, &result, &len);
 492
 493   if (__glibc_unlikely (yperr != YPERR_SUCCESS))
 494     {
 495       enum nss_status retval = yperr2nss (yperr);
 496
 497       if (retval == NSS_STATUS_TRYAGAIN)
 498         *errnop = errno;
 499       return retval;
 500     }
 501
 502   /* Check for adjunct style secret passwords.  They can be recognized
 503      by a password starting with "##".  We do not use it if the
 504      passwd.adjunct.byname table is supposed to be used as a shadow.byname
 505      replacement.  */
 506   char *result2;
 507   int len2;
 508   size_t namelen;
 509   char *p = strchr (result, ':');
 510   if ((_nsl_default_nss () & NSS_FLAG_ADJUNCT_AS_SHADOW) == 0
 511       && p != NULL      /* This better should be true in all cases.  */
 512       && p[1] == '#' && p[2] == '#'
 513       && (namelen = p - result,
 514           yp_match (domain, "passwd.adjunct.byname", result, namelen,
 515                     &result2, &len2)) == YPERR_SUCCESS)
 516     {
 517       /* We found a passwd.adjunct.byname entry.  Merge encrypted password
 518          therein into original result.  */
 519       char *encrypted = strchr (result2, ':');
 520       char *endp;
 521       size_t restlen;
 522
 523       if (encrypted == NULL
 524           || (endp = strchr (++encrypted, ':')) == NULL
 525           || (p = strchr (p + 1, ':')) == NULL)
 526         {
 527           /* Invalid format of the entry.  This never should happen
 528              unless the data from which the NIS table is generated is
 529              wrong.  We simply ignore it.  */
 530           free (result2);
 531           goto non_adjunct;
 532         }
 533
 534       restlen = len - (p - result);
 535       if (__builtin_expect ((size_t) (namelen + (endp - encrypted)
 536                                       + restlen + 2) > buflen, 0))
 537         {
 538           free (result2);
 539           free (result);
 540           *errnop = ERANGE;
 541           return NSS_STATUS_TRYAGAIN;
 542         }
 543
 544       __mempcpy (__mempcpy (__mempcpy (__mempcpy (buffer, result, namelen),
 545                                        ":", 1),
 546                             encrypted, endp - encrypted),
 547                  p, restlen + 1);
 548       p = buffer;
 549
 550       free (result2);
 551     }
 552   else
 553     {
 554     non_adjunct:
 555       if (__glibc_unlikely ((size_t) (len + 1) > buflen))
 556         {
 557           free (result);
 558           *errnop = ERANGE;
 559           return NSS_STATUS_TRYAGAIN;
 560         }
 561
 562       p = strncpy (buffer, result, len);
 563       buffer[len] = '\0';
 564     }
 565
 566   while (isspace (*p))
 567     ++p;
 568   free (result);
 569
 570   int parse_res = _nss_files_parse_pwent (p, pwd, (void *) buffer, buflen,
 571                                           errnop);
 572   if (__glibc_unlikely (parse_res < 1))
 573     {
 574       if (parse_res == -1)
 575         return NSS_STATUS_TRYAGAIN;
 576      else
 577        return NSS_STATUS_NOTFOUND;
 578     }
 579   else
 580     return NSS_STATUS_SUCCESS;
 581 }