nis/nss_nisplus/nisplus-network.c

   1 /* Copyright (C) 1997,1998,2000-2003,2005,2006,2007
   2    Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Thorsten Kukuk <kukuk@vt.uni-paderborn.de>, 1997.
   5
   6    The GNU C Library is free software; you can redistribute it and/or
   7    modify it under the terms of the GNU Lesser General Public
   8    License as published by the Free Software Foundation; either
   9    version 2.1 of the License, or (at your option) any later version.
  10
  11    The GNU C Library is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Lesser General Public License for more details.
  15
  16    You should have received a copy of the GNU Lesser General Public
  17    License along with the GNU C Library; if not, write to the Free
  18    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19    02111-1307 USA.  */
  20
  21 #include <atomic.h>
  22 #include <ctype.h>
  23 #include <errno.h>
  24 #include <netdb.h>
  25 #include <nss.h>
  26 #include <stdint.h>
  27 #include <string.h>
  28 #include <arpa/inet.h>
  29 #include <rpcsvc/nis.h>
  30 #include <bits/libc-lock.h>
  31
  32 #include "nss-nisplus.h"
  33
  34 __libc_lock_define_initialized (static, lock)
  35
  36 static nis_result *result;
  37 static nis_name tablename_val;
  38 static u_long tablename_len;
  39
  40 #define NISENTRYVAL(idx, col, res) \
  41         (NIS_RES_OBJECT (res)[idx].EN_data.en_cols.en_cols_val[col].ec_value.ec_value_val)
  42
  43 #define NISENTRYLEN(idx, col, res) \
  44         (NIS_RES_OBJECT (res)[idx].EN_data.en_cols.en_cols_val[col].ec_value.ec_value_len)
  45
  46
  47 static int
  48 _nss_nisplus_parse_netent (nis_result *result, struct netent *network,
  49                            char *buffer, size_t buflen, int *errnop)
  50 {
  51   char *first_unused = buffer;
  52   size_t room_left = buflen;
  53
  54   if (result == NULL)
  55     return 0;
  56
  57   if ((result->status != NIS_SUCCESS && result->status != NIS_S_SUCCESS)
  58       || __type_of (NIS_RES_OBJECT (result)) != NIS_ENTRY_OBJ
  59       || strcmp (NIS_RES_OBJECT (result)[0].EN_data.en_type,
  60                  "networks_tbl") != 0
  61       || NIS_RES_OBJECT (result)[0].EN_data.en_cols.en_cols_len < 3)
  62     return 0;
  63
  64   if (NISENTRYLEN (0, 0, result) >= room_left)
  65     {
  66       /* The line is too long for our buffer.  */
  67     no_more_room:
  68       *errnop = ERANGE;
  69       return -1;
  70     }
  71
  72   strncpy (first_unused, NISENTRYVAL (0, 0, result),
  73            NISENTRYLEN (0, 0, result));
  74   first_unused[NISENTRYLEN (0, 0, result)] = '\0';
  75   network->n_name = first_unused;
  76   size_t len = strlen (first_unused) + 1;
  77   room_left -= len;
  78   first_unused += len;
  79
  80   network->n_addrtype = 0;
  81   network->n_net = inet_network (NISENTRYVAL (0, 2, result));
  82
  83   /* XXX Rewrite at some point to allocate the array first and then
  84      copy the strings.  It wasteful to first concatenate the strings
  85      to just split them again later.  */
  86   char *line = first_unused;
  87   for (unsigned int i = 0; i < NIS_RES_NUMOBJ (result); ++i)
  88     {
  89       if (strcmp (NISENTRYVAL (i, 1, result), network->n_name) != 0)
  90         {
  91           if (NISENTRYLEN (i, 1, result) + 2 > room_left)
  92             goto no_more_room;
  93
  94           *first_unused++ = ' ';
  95           first_unused = __stpncpy (first_unused, NISENTRYVAL (i, 1, result),
  96                                     NISENTRYLEN (i, 1, result));
  97           room_left -= (NISENTRYLEN (i, 1, result) + 1);
  98         }
  99     }
 100   *first_unused++ = '\0';
 101
 102   /* Adjust the pointer so it is aligned for
 103      storing pointers.  */
 104   size_t adjust = ((__alignof__ (char *)
 105                     - (first_unused - (char *) 0) % __alignof__ (char *))
 106                    % __alignof__ (char *));
 107   if (room_left < adjust + sizeof (char *))
 108     goto no_more_room;
 109   first_unused += adjust;
 110   room_left -= adjust;
 111   network->n_aliases = (char **) first_unused;
 112
 113   /* For the terminating NULL pointer.  */
 114   room_left -= sizeof (char *);
 115
 116   unsigned int i = 0;
 117   while (*line != '\0')
 118     {
 119       /* Skip leading blanks.  */
 120       while (isspace (*line))
 121         ++line;
 122
 123       if (*line == '\0')
 124         break;
 125
 126       if (room_left < sizeof (char *))
 127         goto no_more_room;
 128
 129       room_left -= sizeof (char *);
 130       network->n_aliases[i++] = line;
 131
 132       while (*line != '\0' && *line != ' ')
 133         ++line;
 134
 135       if (*line == ' ')
 136         *line++ = '\0';
 137     }
 138   network->n_aliases[i] = NULL;
 139
 140   return 1;
 141 }
 142
 143
 144 static enum nss_status
 145 _nss_create_tablename (int *errnop)
 146 {
 147   if (tablename_val == NULL)
 148     {
 149       const char *local_dir = nis_local_directory ();
 150       size_t local_dir_len = strlen (local_dir);
 151       static const char prefix[] = "networks.org_dir.";
 152
 153       char *p = malloc (sizeof (prefix) + local_dir_len);
 154       if (p == NULL)
 155         {
 156           *errnop = errno;
 157           return NSS_STATUS_TRYAGAIN;
 158         }
 159
 160       memcpy (__stpcpy (p, prefix), local_dir, local_dir_len + 1);
 161
 162       tablename_len = sizeof (prefix) - 1 + local_dir_len;
 163
 164       atomic_write_barrier ();
 165
 166       tablename_val = p;
 167     }
 168
 169   return NSS_STATUS_SUCCESS;
 170 }
 171
 172 enum nss_status
 173 _nss_nisplus_setnetent (int stayopen)
 174 {
 175   enum nss_status status = NSS_STATUS_SUCCESS;
 176
 177   __libc_lock_lock (lock);
 178
 179   if (result != NULL)
 180     {
 181       nis_freeresult (result);
 182       result = NULL;
 183     }
 184
 185   if (tablename_val == NULL)
 186     {
 187       int err;
 188       status = _nss_create_tablename (&err);
 189     }
 190
 191   __libc_lock_unlock (lock);
 192
 193   return status;
 194 }
 195
 196 enum nss_status
 197 _nss_nisplus_endnetent (void)
 198 {
 199   __libc_lock_lock (lock);
 200
 201   if (result != NULL)
 202     {
 203       nis_freeresult (result);
 204       result = NULL;
 205     }
 206
 207   __libc_lock_unlock (lock);
 208
 209   return NSS_STATUS_SUCCESS;
 210 }
 211
 212 static enum nss_status
 213 internal_nisplus_getnetent_r (struct netent *network, char *buffer,
 214                                size_t buflen, int *errnop, int *herrnop)
 215 {
 216   int parse_res;
 217
 218   /* Get the next entry until we found a correct one. */
 219   do
 220     {
 221       nis_result *saved_res;
 222
 223       if (result == NULL)
 224         {
 225           saved_res = NULL;
 226
 227           if (tablename_val == NULL)
 228             {
 229               enum nss_status status = _nss_create_tablename (errnop);
 230
 231               if (status != NSS_STATUS_SUCCESS)
 232                 return status;
 233             }
 234
 235           result = nis_first_entry (tablename_val);
 236           if (result == NULL)
 237             {
 238               *errnop = errno;
 239               return NSS_STATUS_TRYAGAIN;
 240             }
 241           if (niserr2nss (result->status) != NSS_STATUS_SUCCESS)
 242             {
 243               int retval = niserr2nss (result->status);
 244               nis_freeresult (result);
 245               result = NULL;
 246               if (retval == NSS_STATUS_TRYAGAIN)
 247                 {
 248                   *herrnop = NETDB_INTERNAL;
 249                   *errnop = errno;
 250                   return retval;
 251                 }
 252               else
 253                 return retval;
 254             }
 255         }
 256       else
 257         {
 258           saved_res = result;
 259           result = nis_next_entry (tablename_val, &result->cookie);
 260           if (result == NULL)
 261             {
 262               *errnop = errno;
 263               return NSS_STATUS_TRYAGAIN;
 264             }
 265           if (niserr2nss (result->status) != NSS_STATUS_SUCCESS)
 266             {
 267               int retval = niserr2nss (result->status);
 268               nis_freeresult (result);
 269               result = saved_res;
 270               if (retval == NSS_STATUS_TRYAGAIN)
 271                 {
 272                   *herrnop = NETDB_INTERNAL;
 273                   *errnop = errno;
 274                 }
 275               return retval;
 276             }
 277         }
 278
 279       parse_res = _nss_nisplus_parse_netent (result, network, buffer,
 280                                              buflen, errnop);
 281       if (parse_res == -1)
 282         {
 283           *herrnop = NETDB_INTERNAL;
 284           return NSS_STATUS_TRYAGAIN;
 285         }
 286
 287     }
 288   while (!parse_res);
 289
 290   return NSS_STATUS_SUCCESS;
 291 }
 292
 293 enum nss_status
 294 _nss_nisplus_getnetent_r (struct netent *result, char *buffer,
 295                            size_t buflen, int *errnop, int *herrnop)
 296 {
 297   int status;
 298
 299   __libc_lock_lock (lock);
 300
 301   status = internal_nisplus_getnetent_r (result, buffer, buflen, errnop,
 302                                          herrnop);
 303
 304   __libc_lock_unlock (lock);
 305
 306   return status;
 307 }
 308
 309 enum nss_status
 310 _nss_nisplus_getnetbyname_r (const char *name, struct netent *network,
 311                               char *buffer, size_t buflen, int *errnop,
 312                              int *herrnop)
 313 {
 314   int parse_res, retval;
 315
 316   if (tablename_val == NULL)
 317     {
 318       __libc_lock_lock (lock);
 319
 320       enum nss_status status = _nss_create_tablename (errnop);
 321
 322       __libc_lock_unlock (lock);
 323
 324       if (status != NSS_STATUS_SUCCESS)
 325         return status;
 326     }
 327
 328   if (name == NULL)
 329     {
 330       *errnop = EINVAL;
 331       *herrnop = NETDB_INTERNAL;
 332       return NSS_STATUS_UNAVAIL;
 333     }
 334
 335   nis_result *result;
 336   char buf[strlen (name) + 10 + tablename_len];
 337   int olderr = errno;
 338
 339   /* Search at first in the alias list, and use the correct name
 340      for the next search */
 341   snprintf (buf, sizeof (buf), "[name=%s],%s", name, tablename_val);
 342   result = nis_list (buf, FOLLOW_LINKS | FOLLOW_PATH | USE_DGRAM, NULL, NULL);
 343
 344   if (result != NULL)
 345     {
 346       char *bufptr = buf;
 347
 348       /* If we do not find it, try it as original name. But if the
 349          database is correct, we should find it in the first case, too */
 350       if ((result->status != NIS_SUCCESS
 351            && result->status != NIS_S_SUCCESS)
 352           || __type_of (result->objects.objects_val) != NIS_ENTRY_OBJ
 353           || strcmp (result->objects.objects_val[0].EN_data.en_type,
 354                      "networks_tbl") != 0
 355           || (result->objects.objects_val[0].EN_data.en_cols.en_cols_len
 356               < 3))
 357         snprintf (buf, sizeof (buf), "[cname=%s],%s", name, tablename_val);
 358       else
 359         {
 360           /* We need to allocate a new buffer since there is no
 361              guarantee the returned name has a length limit.  */
 362           const char *entryval = NISENTRYVAL (0, 0, result);
 363           size_t buflen = strlen (entryval) + 10 + tablename_len;
 364           bufptr = alloca (buflen);
 365           snprintf (bufptr, buflen, "[cname=%s],%s",
 366                     entryval, tablename_val);
 367         }
 368
 369       nis_freeresult (result);
 370       result = nis_list (bufptr, FOLLOW_LINKS | FOLLOW_PATH | USE_DGRAM,
 371                          NULL, NULL);
 372     }
 373
 374   if (result == NULL)
 375     {
 376       __set_errno (ENOMEM);
 377       return NSS_STATUS_TRYAGAIN;
 378     }
 379
 380   retval = niserr2nss (result->status);
 381   if (__builtin_expect (retval != NSS_STATUS_SUCCESS, 0))
 382     {
 383       if (retval == NSS_STATUS_TRYAGAIN)
 384         {
 385           *errnop = errno;
 386           *herrnop = NETDB_INTERNAL;
 387         }
 388       else
 389         __set_errno (olderr);
 390       nis_freeresult (result);
 391       return retval;
 392     }
 393
 394   parse_res = _nss_nisplus_parse_netent (result, network, buffer, buflen,
 395                                          errnop);
 396
 397   nis_freeresult (result);
 398
 399   if (parse_res > 0)
 400     return NSS_STATUS_SUCCESS;
 401
 402   *herrnop = NETDB_INTERNAL;
 403   if (parse_res == -1)
 404     {
 405       *errnop = ERANGE;
 406       return NSS_STATUS_TRYAGAIN;
 407     }
 408
 409   __set_errno (olderr);
 410   return NSS_STATUS_NOTFOUND;
 411 }
 412
 413 /* XXX type is ignored, SUN's NIS+ table doesn't support it */
 414 enum nss_status
 415 _nss_nisplus_getnetbyaddr_r (uint32_t addr, const int type,
 416                              struct netent *network, char *buffer,
 417                              size_t buflen, int *errnop, int *herrnop)
 418 {
 419   if (tablename_val == NULL)
 420     {
 421       __libc_lock_lock (lock);
 422
 423       enum nss_status status = _nss_create_tablename (errnop);
 424
 425       __libc_lock_unlock (lock);
 426
 427       if (status != NSS_STATUS_SUCCESS)
 428         return status;
 429     }
 430
 431   {
 432     char buf[27 + tablename_len];
 433     char buf2[18];
 434     int olderr = errno;
 435
 436     struct in_addr in = { .s_addr = htonl (addr) };
 437     strcpy (buf2, inet_ntoa (in));
 438     size_t b2len = strlen (buf2);
 439
 440     while (1)
 441       {
 442         snprintf (buf, sizeof (buf), "[addr=%s],%s", buf2, tablename_val);
 443         nis_result *result = nis_list (buf, EXPAND_NAME | USE_DGRAM,
 444                                        NULL, NULL);
 445
 446         if (result == NULL)
 447           {
 448             __set_errno (ENOMEM);
 449             return NSS_STATUS_TRYAGAIN;
 450           }
 451         enum nss_status retval = niserr2nss (result->status);
 452         if (__builtin_expect (retval != NSS_STATUS_SUCCESS, 0))
 453           {
 454             if (b2len > 2 && buf2[b2len - 2] == '.' && buf2[b2len - 1] == '0')
 455               {
 456                 /* Try again, but with trailing dot(s)
 457                    removed (one by one) */
 458                 buf2[b2len - 2] = '\0';
 459                 b2len -= 2;
 460                 nis_freeresult (result);
 461                 continue;
 462               }
 463
 464             if (retval == NSS_STATUS_TRYAGAIN)
 465               {
 466                 *errnop = errno;
 467                 *herrnop = NETDB_INTERNAL;
 468               }
 469             else
 470               __set_errno (olderr);
 471             nis_freeresult (result);
 472             return retval;
 473           }
 474
 475         int parse_res = _nss_nisplus_parse_netent (result, network, buffer,
 476                                                    buflen, errnop);
 477
 478         nis_freeresult (result);
 479
 480         if (parse_res > 0)
 481           return NSS_STATUS_SUCCESS;
 482
 483         *herrnop = NETDB_INTERNAL;
 484         if (parse_res == -1)
 485           {
 486             *errnop = ERANGE;
 487             return NSS_STATUS_TRYAGAIN;
 488           }
 489         else
 490           {
 491             __set_errno (olderr);
 492             return NSS_STATUS_NOTFOUND;
 493           }
 494       }
 495   }
 496 }