nis/nss_nisplus/nisplus-hosts.c

   1 /* Copyright (C) 1997-2002, 2003, 2005, 2006 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         (NIS_RES_OBJECT (res)[idx].EN_data.en_cols.en_cols_val[col].ec_value.ec_value_val)
  41
  42 #define NISENTRYLEN(idx, col, res) \
  43         (NIS_RES_OBJECT (res)[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
  49 static int
  50 _nss_nisplus_parse_hostent (nis_result *result, int af, struct hostent *host,
  51                             char *buffer, size_t buflen, int *errnop,
  52                             int flags)
  53 {
  54   unsigned int i;
  55   char *first_unused = buffer;
  56   size_t room_left = buflen;
  57
  58   if (result == NULL)
  59     return 0;
  60
  61   if ((result->status != NIS_SUCCESS && result->status != NIS_S_SUCCESS) ||
  62       __type_of (NIS_RES_OBJECT (result)) != NIS_ENTRY_OBJ ||
  63       strcmp(NIS_RES_OBJECT (result)[0].EN_data.en_type, "hosts_tbl") != 0 ||
  64       NIS_RES_OBJECT (result)[0].EN_data.en_cols.en_cols_len < 4)
  65     return 0;
  66
  67   char *data = first_unused;
  68
  69   if (room_left < (af == AF_INET6 || (flags & AI_V4MAPPED) != 0
  70                    ? IN6ADDRSZ : INADDRSZ))
  71     {
  72     no_more_room:
  73       *errnop = ERANGE;
  74       return -1;
  75     }
  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   host->h_name = first_unused;
 109   first_unused = __stpncpy (first_unused, NISENTRYVAL (0, 0, result),
 110                             NISENTRYLEN (0, 0, result));
 111   *first_unused++ = '\0';
 112   room_left -= NISENTRYLEN (0, 0, result) + 1;
 113
 114   /* XXX Rewrite at some point to allocate the array first and then
 115      copy the strings.  It wasteful to first concatenate the strings
 116      to just split them again later.  */
 117   char *line = first_unused;
 118   for (i = 0; i < NIS_RES_NUMOBJ (result); ++i)
 119     {
 120       if (strcmp (NISENTRYVAL (i, 1, result), host->h_name) != 0)
 121         {
 122           if (NISENTRYLEN (i, 1, result) + 2 > room_left)
 123             goto no_more_room;
 124
 125           *first_unused++ = ' ';
 126           first_unused = __stpncpy (first_unused, NISENTRYVAL (i, 1, result),
 127                                     NISENTRYLEN (i, 1, result));
 128           *first_unused = '\0';
 129           room_left -= NISENTRYLEN (i, 1, result) + 1;
 130         }
 131     }
 132   *first_unused++ = '\0';
 133
 134   /* Adjust the pointer so it is aligned for
 135      storing pointers.  */
 136   size_t adjust = ((__alignof__ (char *)
 137                     - (first_unused - (char *) 0) % __alignof__ (char *))
 138                    % __alignof__ (char *));
 139   if (room_left < adjust + 3 * sizeof (char *))
 140     goto no_more_room;
 141   first_unused += adjust;
 142   room_left -= adjust;
 143   host->h_addr_list = (char **) first_unused;
 144
 145   room_left -= 3 * sizeof (char *);
 146   host->h_addr_list[0] = data;
 147   host->h_addr_list[1] = NULL;
 148   host->h_aliases = &host->h_addr_list[2];
 149
 150   i = 0;
 151   while (*line != '\0')
 152     {
 153       /* Skip leading blanks.  */
 154       while (isspace (*line))
 155         ++line;
 156
 157       if (*line == '\0')
 158         break;
 159
 160       if (room_left < sizeof (char *))
 161         goto no_more_room;
 162
 163       room_left -= sizeof (char *);
 164       host->h_aliases[i++] = line;
 165
 166       while (*line != '\0' && *line != ' ')
 167         ++line;
 168
 169       if (*line == ' ')
 170         *line++ = '\0';
 171     }
 172
 173   host->h_aliases[i] = NULL;
 174
 175   return 1;
 176 }
 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 (p == 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 (result == NULL)
 269             {
 270               *errnop = errno;
 271               return NSS_STATUS_TRYAGAIN;
 272             }
 273           if (niserr2nss (result->status) != NSS_STATUS_SUCCESS)
 274             {
 275               enum nss_status retval = niserr2nss (result->status);
 276               if (retval == NSS_STATUS_TRYAGAIN)
 277                 {
 278                   *herrnop = NETDB_INTERNAL;
 279                   *errnop = errno;
 280                 }
 281               return retval;
 282             }
 283
 284         }
 285       else
 286         {
 287           saved_res = result;
 288           result = nis_next_entry (tablename_val, &result->cookie);
 289           if (result == NULL)
 290             {
 291               *errnop = errno;
 292               return NSS_STATUS_TRYAGAIN;
 293             }
 294           if (niserr2nss (result->status) != NSS_STATUS_SUCCESS)
 295             {
 296               enum nss_status retval= niserr2nss (result->status);
 297
 298               nis_freeresult (result);
 299               result = saved_res;
 300               if (retval == NSS_STATUS_TRYAGAIN)
 301                 {
 302                   *herrnop = NETDB_INTERNAL;
 303                   *errnop = errno;
 304                 }
 305               return retval;
 306             }
 307         }
 308
 309       if (_res.options & RES_USE_INET6)
 310         parse_res = _nss_nisplus_parse_hostent (result, AF_INET6, host, buffer,
 311                                                 buflen, errnop, AI_V4MAPPED);
 312       else
 313         parse_res = _nss_nisplus_parse_hostent (result, AF_INET, host, buffer,
 314                                                 buflen, errnop, 0);
 315
 316       if (parse_res == -1)
 317         {
 318           nis_freeresult (result);
 319           result = saved_res;
 320           *herrnop = NETDB_INTERNAL;
 321           *errnop = ERANGE;
 322           return NSS_STATUS_TRYAGAIN;
 323         }
 324       if (saved_res != NULL)
 325         nis_freeresult (saved_res);
 326
 327     } while (!parse_res);
 328
 329   return NSS_STATUS_SUCCESS;
 330 }
 331
 332 enum nss_status
 333 _nss_nisplus_gethostent_r (struct hostent *result, char *buffer,
 334                            size_t buflen, int *errnop, int *herrnop)
 335 {
 336   int status;
 337
 338   __libc_lock_lock (lock);
 339
 340   status = internal_nisplus_gethostent_r (result, buffer, buflen, errnop,
 341                                           herrnop);
 342
 343   __libc_lock_unlock (lock);
 344
 345   return status;
 346 }
 347
 348 static enum nss_status
 349 internal_gethostbyname2_r (const char *name, int af, struct hostent *host,
 350                            char *buffer, size_t buflen, int *errnop,
 351                            int *herrnop, int flags)
 352 {
 353   int parse_res, retval;
 354
 355   if (tablename_val == NULL)
 356     {
 357       __libc_lock_lock (lock);
 358
 359       enum nss_status status = _nss_create_tablename (errnop);
 360
 361       __libc_lock_unlock (lock);
 362
 363       if (status != NSS_STATUS_SUCCESS)
 364         {
 365           *herrnop = NETDB_INTERNAL;
 366           return NSS_STATUS_UNAVAIL;
 367         }
 368     }
 369
 370   if (name == NULL)
 371     {
 372       *errnop = EINVAL;
 373       *herrnop = NETDB_INTERNAL;
 374       return NSS_STATUS_NOTFOUND;
 375     }
 376
 377   nis_result *result;
 378   char buf[strlen (name) + 10 + tablename_len];
 379   int olderr = errno;
 380
 381   /* Search at first in the alias list, and use the correct name
 382      for the next search.  */
 383   snprintf (buf, sizeof (buf), "[name=%s],%s", name, tablename_val);
 384   result = nis_list (buf, FOLLOW_PATH | FOLLOW_LINKS, NULL, NULL);
 385
 386   if (result != NULL)
 387     {
 388       char *bufptr = buf;
 389
 390       /* If we did not find it, try it as original name. But if the
 391          database is correct, we should find it in the first case, too.  */
 392       if ((result->status != NIS_SUCCESS
 393            && result->status != NIS_S_SUCCESS)
 394           || __type_of (result->objects.objects_val) != NIS_ENTRY_OBJ
 395           || strcmp (result->objects.objects_val->EN_data.en_type,
 396                      "hosts_tbl") != 0
 397           || result->objects.objects_val->EN_data.en_cols.en_cols_len < 3)
 398         snprintf (buf, sizeof (buf), "[cname=%s],%s", name, tablename_val);
 399       else
 400         {
 401           /* We need to allocate a new buffer since there is no
 402              guarantee the returned name has a length limit.  */
 403           const char *entryval = NISENTRYVAL(0, 0, result);
 404           size_t buflen = strlen (entryval) + 10 + tablename_len;
 405           bufptr = alloca (buflen);
 406           snprintf (bufptr, buflen, "[cname=%s],%s",
 407                     entryval, tablename_val);
 408         }
 409
 410       nis_freeresult (result);
 411       result = nis_list (bufptr, FOLLOW_PATH | FOLLOW_LINKS, NULL, NULL);
 412     }
 413
 414   if (result == NULL)
 415     {
 416       *errnop = ENOMEM;
 417       return NSS_STATUS_TRYAGAIN;
 418     }
 419
 420   retval = niserr2nss (result->status);
 421   if (__builtin_expect (retval != NSS_STATUS_SUCCESS, 0))
 422     {
 423       if (retval == NSS_STATUS_TRYAGAIN)
 424         {
 425           *errnop = errno;
 426           *herrnop = NETDB_INTERNAL;
 427         }
 428       else
 429         __set_errno (olderr);
 430       nis_freeresult (result);
 431       return retval;
 432     }
 433
 434   parse_res = _nss_nisplus_parse_hostent (result, af, host, buffer,
 435                                           buflen, errnop, flags);
 436
 437   nis_freeresult (result);
 438
 439   if (parse_res > 0)
 440     return NSS_STATUS_SUCCESS;
 441
 442   *herrnop = NETDB_INTERNAL;
 443   if (parse_res == -1)
 444     {
 445       *errnop = ERANGE;
 446       return NSS_STATUS_TRYAGAIN;
 447     }
 448
 449   __set_errno (olderr);
 450   return NSS_STATUS_NOTFOUND;
 451 }
 452
 453 enum nss_status
 454 _nss_nisplus_gethostbyname2_r (const char *name, int af, struct hostent *host,
 455                                char *buffer, size_t buflen, int *errnop,
 456                                int *herrnop)
 457 {
 458   return internal_gethostbyname2_r (name, af, host, buffer, buflen, errnop,
 459                                     herrnop,
 460                          ((_res.options & RES_USE_INET6) ? AI_V4MAPPED : 0));
 461 }
 462
 463 enum nss_status
 464 _nss_nisplus_gethostbyname_r (const char *name, struct hostent *host,
 465                               char *buffer, size_t buflen, int *errnop,
 466                               int *h_errnop)
 467 {
 468   if (_res.options & RES_USE_INET6)
 469     {
 470       enum nss_status status;
 471
 472       status = internal_gethostbyname2_r (name, AF_INET6, host, buffer,
 473                                           buflen, errnop, h_errnop,
 474                                           AI_V4MAPPED);
 475       if (status == NSS_STATUS_SUCCESS)
 476         return status;
 477     }
 478
 479   return internal_gethostbyname2_r (name, AF_INET, host, buffer,
 480                                    buflen, errnop, h_errnop, 0);
 481 }
 482
 483 enum nss_status
 484 _nss_nisplus_gethostbyaddr_r (const void *addr, socklen_t addrlen, int af,
 485                               struct hostent *host, char *buffer,
 486                               size_t buflen, int *errnop, int *herrnop)
 487 {
 488   if (tablename_val == NULL)
 489     {
 490       __libc_lock_lock (lock);
 491
 492       enum nss_status status = _nss_create_tablename (errnop);
 493
 494       __libc_lock_unlock (lock);
 495
 496       if (status != NSS_STATUS_SUCCESS)
 497         return status;
 498     }
 499
 500   if (addr == NULL)
 501     return NSS_STATUS_NOTFOUND;
 502
 503   char buf[24 + tablename_len];
 504   int retval, parse_res;
 505   int olderr = errno;
 506
 507   snprintf (buf, sizeof (buf), "[addr=%s],%s",
 508            inet_ntoa (*(const struct in_addr *) addr), tablename_val);
 509   nis_result *result = nis_list (buf, FOLLOW_PATH | FOLLOW_LINKS, NULL, NULL);
 510
 511   if (result == NULL)
 512     {
 513       __set_errno (ENOMEM);
 514       return NSS_STATUS_TRYAGAIN;
 515     }
 516
 517   retval = niserr2nss (result->status);
 518   if (__builtin_expect (retval != NSS_STATUS_SUCCESS, 0))
 519     {
 520       if (retval == NSS_STATUS_TRYAGAIN)
 521         {
 522           *errnop = errno;
 523           *herrnop = NETDB_INTERNAL;
 524         }
 525       else
 526         __set_errno (olderr);
 527       nis_freeresult (result);
 528       return retval;
 529     }
 530
 531   parse_res = _nss_nisplus_parse_hostent (result, af, host,
 532                                           buffer, buflen, errnop,
 533                                           ((_res.options & RES_USE_INET6)
 534                                            ? AI_V4MAPPED : 0));
 535   nis_freeresult (result);
 536
 537   if (parse_res > 0)
 538     return NSS_STATUS_SUCCESS;
 539
 540   *herrnop = NETDB_INTERNAL;
 541   if (parse_res == -1)
 542     {
 543       *errnop = ERANGE;
 544       return NSS_STATUS_TRYAGAIN;
 545     }
 546
 547   __set_errno (olderr);
 548   return NSS_STATUS_NOTFOUND;
 549 }