nis/nss_nisplus/nisplus-hosts.c

   1 /* Copyright (C) 1997-2002, 2003, 2005 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Thorsten Kukuk <kukuk@suse.de>, 1997.
   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 <atomic.h>
  21 #include <ctype.h>
  22 #include <errno.h>
  23 #include <netdb.h>
  24 #include <nss.h>
  25 #include <string.h>
  26 #include <arpa/inet.h>
  27 #include <netinet/in.h>
  28 #include <rpcsvc/nis.h>
  29 #include <bits/libc-lock.h>
  30
  31 #include "nss-nisplus.h"
  32
  33 __libc_lock_define_initialized (static, lock)
  34
  35 static nis_result *result;
  36 static nis_name tablename_val;
  37 static u_long tablename_len;
  38
  39 #define NISENTRYVAL(idx,col,res) \
  40         ((res)->objects.objects_val[(idx)].EN_data.en_cols.en_cols_val[(col)].ec_value.ec_value_val)
  41
  42 #define NISENTRYLEN(idx,col,res) \
  43         ((res)->objects.objects_val[(idx)].EN_data.en_cols.en_cols_val[(col)].ec_value.ec_value_len)
  44
  45 /* Get implementation for some internal functions. */
  46 #include <resolv/mapv4v6addr.h>
  47
  48 static int
  49 _nss_nisplus_parse_hostent (nis_result *result, int af, struct hostent *host,
  50                             char *buffer, size_t buflen, int *errnop,
  51                             int flags)
  52 {
  53   unsigned int i;
  54   char *first_unused = buffer;
  55   size_t room_left = buflen;
  56   char *data, *p, *line;
  57
  58   if (result == NULL)
  59     return 0;
  60
  61   if ((result->status != NIS_SUCCESS && result->status != NIS_S_SUCCESS) ||
  62       __type_of (result->objects.objects_val) != NIS_ENTRY_OBJ ||
  63       strcmp(result->objects.objects_val[0].EN_data.en_type,
  64              "hosts_tbl") != 0 ||
  65       result->objects.objects_val[0].EN_data.en_cols.en_cols_len < 4)
  66     return 0;
  67
  68   if (room_left < NISENTRYLEN (0, 2, result) + 1)
  69     {
  70     no_more_room:
  71       *errnop = ERANGE;
  72       return -1;
  73     }
  74
  75   data = first_unused;
  76
  77   /* Parse address.  */
  78   if (af == AF_INET && inet_pton (af, NISENTRYVAL (0, 2, result), data) > 0)
  79     {
  80       if (flags & AI_V4MAPPED)
  81         {
  82           map_v4v6_address (data, data);
  83           host->h_addrtype = AF_INET6;
  84           host->h_length = IN6ADDRSZ;
  85         }
  86       else
  87         {
  88           host->h_addrtype = AF_INET;
  89           host->h_length = INADDRSZ;
  90         }
  91     }
  92   else if (af == AF_INET6
  93            && inet_pton (AF_INET6, NISENTRYVAL (0, 2, result), data) > 0)
  94     {
  95       host->h_addrtype = AF_INET6;
  96       host->h_length = IN6ADDRSZ;
  97     }
  98   else
  99     /* Illegal address: ignore line.  */
 100     return 0;
 101
 102   first_unused+=host->h_length;
 103   room_left-=host->h_length;
 104
 105   if (NISENTRYLEN (0, 0, result) + 1 > room_left)
 106     goto no_more_room;
 107
 108   p = __stpncpy (first_unused, NISENTRYVAL (0, 0, result),
 109                  NISENTRYLEN (0, 0, result));
 110   *p = '\0';
 111   room_left -= (NISENTRYLEN (0, 0, result) + 1);
 112   host->h_name = first_unused;
 113   first_unused += NISENTRYLEN (0, 0, result) +1;
 114   p = first_unused;
 115
 116   line = p;
 117   for (i = 0; i < result->objects.objects_len; ++i)
 118     {
 119       if (strcmp (NISENTRYVAL (i, 1, result), host->h_name) != 0)
 120         {
 121           if (NISENTRYLEN (i, 1, result) + 2 > room_left)
 122             goto no_more_room;
 123
 124           *p++ = ' ';
 125           p = __stpncpy (p, NISENTRYVAL (i, 1, result),
 126                          NISENTRYLEN (i, 1, result));
 127           *p = '\0';
 128           room_left -= (NISENTRYLEN (i, 1, result) + 1);
 129         }
 130     }
 131   *p++ = '\0';
 132   first_unused = p;
 133
 134   /* Adjust the pointer so it is aligned for
 135      storing pointers.  */
 136   first_unused += __alignof__ (char *) - 1;
 137   first_unused -= ((first_unused - (char *) 0) % __alignof__ (char *));
 138   host->h_addr_list = (char **) first_unused;
 139   if (room_left < 2 * sizeof (char *))
 140     goto no_more_room;
 141
 142   room_left -= (2 * sizeof (char *));
 143   host->h_addr_list[0] = data;
 144   host->h_addr_list[1] = NULL;
 145   host->h_aliases = &host->h_addr_list[2];
 146   host->h_aliases[0] = NULL;
 147
 148   i = 0;
 149   while (*line != '\0')
 150     {
 151       /* Skip leading blanks.  */
 152       while (isspace (*line))
 153         ++line;
 154
 155       if (*line == '\0')
 156         break;
 157
 158       if (room_left < sizeof (char *))
 159         goto no_more_room;
 160
 161       room_left -= sizeof (char *);
 162       host->h_aliases[i] = line;
 163
 164       while (*line != '\0' && *line != ' ')
 165         ++line;
 166
 167       if (*line == ' ')
 168         {
 169           *line = '\0';
 170           ++line;
 171           ++i;
 172         }
 173       else
 174         host->h_aliases[i+1] = NULL;
 175     }
 176   return 1;
 177 }
 178
 179 static enum nss_status
 180 _nss_create_tablename (int *errnop)
 181 {
 182   if (tablename_val == NULL)
 183     {
 184       const char *local_dir = nis_local_directory ();
 185       size_t local_dir_len = strlen (local_dir);
 186       static const char prefix[] = "hosts.org_dir.";
 187
 188       char *p = malloc (sizeof (prefix) + local_dir_len);
 189       if (tablename_val == NULL)
 190         {
 191           *errnop = errno;
 192           return NSS_STATUS_TRYAGAIN;
 193         }
 194
 195       memcpy (__stpcpy (p, prefix), local_dir, local_dir_len + 1);
 196
 197       tablename_len = sizeof (prefix) - 1 + local_dir_len;
 198
 199       atomic_write_barrier ();
 200
 201       tablename_val = p;
 202     }
 203
 204   return NSS_STATUS_SUCCESS;
 205 }
 206
 207 enum nss_status
 208 _nss_nisplus_sethostent (int stayopen)
 209 {
 210   enum nss_status status = NSS_STATUS_SUCCESS;
 211   int err;
 212
 213   __libc_lock_lock (lock);
 214
 215   if (result != NULL)
 216     {
 217       nis_freeresult (result);
 218       result = NULL;
 219     }
 220
 221   if (tablename_val == NULL)
 222     status = _nss_create_tablename (&err);
 223
 224   __libc_lock_unlock (lock);
 225
 226   return status;
 227 }
 228
 229 enum nss_status
 230 _nss_nisplus_endhostent (void)
 231 {
 232   __libc_lock_lock (lock);
 233
 234   if (result != NULL)
 235     {
 236       nis_freeresult (result);
 237       result = NULL;
 238     }
 239
 240   __libc_lock_unlock (lock);
 241
 242   return NSS_STATUS_SUCCESS;
 243 }
 244
 245 static enum nss_status
 246 internal_nisplus_gethostent_r (struct hostent *host, char *buffer,
 247                                size_t buflen, int *errnop, int *herrnop)
 248 {
 249   int parse_res;
 250
 251   /* Get the next entry until we found a correct one. */
 252   do
 253     {
 254       nis_result *saved_res;
 255
 256       if (result == NULL)
 257         {
 258           saved_res = NULL;
 259           if (tablename_val == NULL)
 260             {
 261               enum nss_status status = _nss_create_tablename (errnop);
 262
 263               if (status != NSS_STATUS_SUCCESS)
 264                 return status;
 265             }
 266
 267           result = nis_first_entry (tablename_val);
 268           if (niserr2nss (result->status) != NSS_STATUS_SUCCESS)
 269             {
 270               enum nss_status retval = niserr2nss (result->status);
 271               if (retval == NSS_STATUS_TRYAGAIN)
 272                 {
 273                   *herrnop = NETDB_INTERNAL;
 274                   *errnop = errno;
 275                 }
 276               return retval;
 277             }
 278
 279         }
 280       else
 281         {
 282           nis_result *res2;
 283
 284           saved_res = result;
 285           res2 = nis_next_entry(tablename_val, &result->cookie);
 286           result = res2;
 287           if (niserr2nss (result->status) != NSS_STATUS_SUCCESS)
 288             {
 289               enum nss_status retval= niserr2nss (result->status);
 290
 291               nis_freeresult (result);
 292               result = saved_res;
 293               if (retval == NSS_STATUS_TRYAGAIN)
 294                 {
 295                   *herrnop = NETDB_INTERNAL;
 296                   *errnop = errno;
 297                 }
 298               return retval;
 299             }
 300         }
 301
 302       if (_res.options & RES_USE_INET6)
 303         parse_res = _nss_nisplus_parse_hostent (result, AF_INET6, host, buffer,
 304                                                 buflen, errnop, AI_V4MAPPED);
 305       else
 306         parse_res = _nss_nisplus_parse_hostent (result, AF_INET, host, buffer,
 307                                                 buflen, errnop, 0);
 308
 309       if (parse_res == -1)
 310         {
 311           nis_freeresult (result);
 312           result = saved_res;
 313           *herrnop = NETDB_INTERNAL;
 314           *errnop = ERANGE;
 315           return NSS_STATUS_TRYAGAIN;
 316         }
 317       if (saved_res != NULL)
 318         nis_freeresult (saved_res);
 319
 320     } while (!parse_res);
 321
 322   return NSS_STATUS_SUCCESS;
 323 }
 324
 325 enum nss_status
 326 _nss_nisplus_gethostent_r (struct hostent *result, char *buffer,
 327                            size_t buflen, int *errnop, int *herrnop)
 328 {
 329   int status;
 330
 331   __libc_lock_lock (lock);
 332
 333   status = internal_nisplus_gethostent_r (result, buffer, buflen, errnop,
 334                                           herrnop);
 335
 336   __libc_lock_unlock (lock);
 337
 338   return status;
 339 }
 340
 341 static enum nss_status
 342 internal_gethostbyname2_r (const char *name, int af, struct hostent *host,
 343                            char *buffer, size_t buflen, int *errnop,
 344                            int *herrnop, int flags)
 345 {
 346   int parse_res, retval;
 347
 348   if (tablename_val == NULL)
 349     {
 350       __libc_lock_lock (lock);
 351
 352       enum nss_status status = _nss_create_tablename (errnop);
 353
 354       __libc_lock_unlock (lock);
 355
 356       if (status != NSS_STATUS_SUCCESS)
 357         {
 358           *herrnop = NETDB_INTERNAL;
 359           return NSS_STATUS_UNAVAIL;
 360         }
 361     }
 362
 363   if (name == NULL)
 364     {
 365       *errnop = EINVAL;
 366       *herrnop = NETDB_INTERNAL;
 367       return NSS_STATUS_NOTFOUND;
 368     }
 369
 370   nis_result *result;
 371   char buf[strlen (name) + 10 + tablename_len];
 372   int olderr = errno;
 373
 374   /* Search at first in the alias list, and use the correct name
 375      for the next search.  */
 376   snprintf (buf, sizeof (buf), "[name=%s],%s", name, tablename_val);
 377   result = nis_list (buf, FOLLOW_PATH | FOLLOW_LINKS, NULL, NULL);
 378
 379   if (result != NULL)
 380     {
 381       char *bufptr = buf;
 382
 383       /* If we did not find it, try it as original name. But if the
 384          database is correct, we should find it in the first case, too.  */
 385       if ((result->status != NIS_SUCCESS
 386            && result->status != NIS_S_SUCCESS)
 387           || __type_of (result->objects.objects_val) != NIS_ENTRY_OBJ
 388           || strcmp (result->objects.objects_val->EN_data.en_type,
 389                      "hosts_tbl") != 0
 390           || result->objects.objects_val->EN_data.en_cols.en_cols_len < 3)
 391         snprintf (buf, sizeof (buf), "[cname=%s],%s", name, tablename_val);
 392       else
 393         {
 394           /* We need to allocate a new buffer since there is no
 395              guarantee the returned name has a length limit.  */
 396           const char *entryval = NISENTRYVAL(0, 0, result);
 397           size_t buflen = strlen (entryval) + 10 + tablename_len;
 398           bufptr = alloca (buflen);
 399           snprintf (bufptr, buflen, "[cname=%s],%s",
 400                     entryval, tablename_val);
 401         }
 402
 403       nis_freeresult (result);
 404       result = nis_list (bufptr, FOLLOW_PATH | FOLLOW_LINKS, NULL, NULL);
 405     }
 406
 407   if (result == NULL)
 408     {
 409       *errnop = ENOMEM;
 410       return NSS_STATUS_TRYAGAIN;
 411     }
 412
 413   retval = niserr2nss (result->status);
 414   if (__builtin_expect (retval != NSS_STATUS_SUCCESS, 0))
 415     {
 416       if (retval == NSS_STATUS_TRYAGAIN)
 417         {
 418           *errnop = errno;
 419           *herrnop = NETDB_INTERNAL;
 420         }
 421       else
 422         __set_errno (olderr);
 423       nis_freeresult (result);
 424       return retval;
 425     }
 426
 427   parse_res = _nss_nisplus_parse_hostent (result, af, host, buffer,
 428                                           buflen, errnop, flags);
 429
 430   nis_freeresult (result);
 431
 432   if (parse_res > 0)
 433     return NSS_STATUS_SUCCESS;
 434
 435   *herrnop = NETDB_INTERNAL;
 436   if (parse_res == -1)
 437     {
 438       *errnop = ERANGE;
 439       return NSS_STATUS_TRYAGAIN;
 440     }
 441
 442   __set_errno (olderr);
 443   return NSS_STATUS_NOTFOUND;
 444 }
 445
 446 enum nss_status
 447 _nss_nisplus_gethostbyname2_r (const char *name, int af, struct hostent *host,
 448                                char *buffer, size_t buflen, int *errnop,
 449                                int *herrnop)
 450 {
 451   return internal_gethostbyname2_r (name, af, host, buffer, buflen, errnop,
 452                                     herrnop,
 453                          ((_res.options & RES_USE_INET6) ? AI_V4MAPPED : 0));
 454 }
 455
 456 enum nss_status
 457 _nss_nisplus_gethostbyname_r (const char *name, struct hostent *host,
 458                               char *buffer, size_t buflen, int *errnop,
 459                               int *h_errnop)
 460 {
 461   if (_res.options & RES_USE_INET6)
 462     {
 463       enum nss_status status;
 464
 465       status = internal_gethostbyname2_r (name, AF_INET6, host, buffer,
 466                                           buflen, errnop, h_errnop,
 467                                           AI_V4MAPPED);
 468       if (status == NSS_STATUS_SUCCESS)
 469         return status;
 470     }
 471
 472   return internal_gethostbyname2_r (name, AF_INET, host, buffer,
 473                                    buflen, errnop, h_errnop, 0);
 474 }
 475
 476 enum nss_status
 477 _nss_nisplus_gethostbyaddr_r (const void *addr, socklen_t addrlen, int af,
 478                               struct hostent *host, char *buffer,
 479                               size_t buflen, int *errnop, int *herrnop)
 480 {
 481   if (tablename_val == NULL)
 482     {
 483       __libc_lock_lock (lock);
 484
 485       enum nss_status status = _nss_create_tablename (errnop);
 486
 487       __libc_lock_unlock (lock);
 488
 489       if (status != NSS_STATUS_SUCCESS)
 490         return status;
 491     }
 492
 493   if (addr == NULL)
 494     return NSS_STATUS_NOTFOUND;
 495
 496   char buf[24 + tablename_len];
 497   int retval, parse_res;
 498   int olderr = errno;
 499
 500   snprintf (buf, sizeof (buf), "[addr=%s],%s",
 501            inet_ntoa (*(const struct in_addr *) addr), tablename_val);
 502   nis_result *result = nis_list (buf, FOLLOW_PATH | FOLLOW_LINKS, NULL, NULL);
 503
 504   if (result == NULL)
 505     {
 506       __set_errno (ENOMEM);
 507       return NSS_STATUS_TRYAGAIN;
 508     }
 509
 510   retval = niserr2nss (result->status);
 511   if (__builtin_expect (retval != NSS_STATUS_SUCCESS, 0))
 512     {
 513       if (retval == NSS_STATUS_TRYAGAIN)
 514         {
 515           *errnop = errno;
 516           *herrnop = NETDB_INTERNAL;
 517         }
 518       else
 519         __set_errno (olderr);
 520       nis_freeresult (result);
 521       return retval;
 522     }
 523
 524   parse_res = _nss_nisplus_parse_hostent (result, af, host,
 525                                           buffer, buflen, errnop,
 526                                           ((_res.options & RES_USE_INET6)
 527                                            ? AI_V4MAPPED : 0));
 528   nis_freeresult (result);
 529
 530   if (parse_res > 0)
 531     return NSS_STATUS_SUCCESS;
 532
 533   *herrnop = NETDB_INTERNAL;
 534   if (parse_res == -1)
 535     {
 536       *errnop = ERANGE;
 537       return NSS_STATUS_TRYAGAIN;
 538     }
 539
 540   __set_errno (olderr);
 541   return NSS_STATUS_NOTFOUND;
 542 }