nis/nss_nisplus/nisplus-network.c

   1 /* Copyright (C) 1997-2018 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Thorsten Kukuk <kukuk@vt.uni-paderborn.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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <atomic.h>
  20 #include <ctype.h>
  21 #include <errno.h>
  22 #include <netdb.h>
  23 #include <nss.h>
  24 #include <stdint.h>
  25 #include <string.h>
  26 #include <arpa/inet.h>
  27 #include <rpcsvc/nis.h>
  28 #include <libc-lock.h>
  29
  30 #include "nss-nisplus.h"
  31
  32 __libc_lock_define_initialized (static, lock)
  33
  34 static nis_result *result;
  35 static nis_name tablename_val;
  36 static u_long tablename_len;
  37
  38 #define NISENTRYVAL(idx, col, res) \
  39         (NIS_RES_OBJECT (res)[idx].EN_data.en_cols.en_cols_val[col].ec_value.ec_value_val)
  40
  41 #define NISENTRYLEN(idx, col, res) \
  42         (NIS_RES_OBJECT (res)[idx].EN_data.en_cols.en_cols_val[col].ec_value.ec_value_len)
  43
  44
  45 static int
  46 _nss_nisplus_parse_netent (nis_result *result, struct netent *network,
  47                            char *buffer, size_t buflen, int *errnop)
  48 {
  49   char *first_unused = buffer;
  50   size_t room_left = buflen;
  51
  52   if (result == NULL)
  53     return 0;
  54
  55   if ((result->status != NIS_SUCCESS && result->status != NIS_S_SUCCESS)
  56       || __type_of (NIS_RES_OBJECT (result)) != NIS_ENTRY_OBJ
  57       || strcmp (NIS_RES_OBJECT (result)[0].EN_data.en_type,
  58                  "networks_tbl") != 0
  59       || NIS_RES_OBJECT (result)[0].EN_data.en_cols.en_cols_len < 3)
  60     return 0;
  61
  62   if (NISENTRYLEN (0, 0, result) >= room_left)
  63     {
  64       /* The line is too long for our buffer.  */
  65     no_more_room:
  66       *errnop = ERANGE;
  67       return -1;
  68     }
  69
  70   strncpy (first_unused, NISENTRYVAL (0, 0, result),
  71            NISENTRYLEN (0, 0, result));
  72   first_unused[NISENTRYLEN (0, 0, result)] = '\0';
  73   network->n_name = first_unused;
  74   size_t len = strlen (first_unused) + 1;
  75   room_left -= len;
  76   first_unused += len;
  77
  78   network->n_addrtype = 0;
  79   network->n_net = inet_network (NISENTRYVAL (0, 2, result));
  80
  81   /* XXX Rewrite at some point to allocate the array first and then
  82      copy the strings.  It wasteful to first concatenate the strings
  83      to just split them again later.  */
  84   char *line = first_unused;
  85   for (unsigned int i = 0; i < NIS_RES_NUMOBJ (result); ++i)
  86     {
  87       if (strcmp (NISENTRYVAL (i, 1, result), network->n_name) != 0)
  88         {
  89           if (NISENTRYLEN (i, 1, result) + 2 > room_left)
  90             goto no_more_room;
  91
  92           *first_unused++ = ' ';
  93           first_unused = __stpncpy (first_unused, NISENTRYVAL (i, 1, result),
  94                                     NISENTRYLEN (i, 1, result));
  95           room_left -= (NISENTRYLEN (i, 1, result) + 1);
  96         }
  97     }
  98   *first_unused++ = '\0';
  99
 100   /* Adjust the pointer so it is aligned for
 101      storing pointers.  */
 102   size_t adjust = ((__alignof__ (char *)
 103                     - (first_unused - (char *) 0) % __alignof__ (char *))
 104                    % __alignof__ (char *));
 105   if (room_left < adjust + sizeof (char *))
 106     goto no_more_room;
 107   first_unused += adjust;
 108   room_left -= adjust;
 109   network->n_aliases = (char **) first_unused;
 110
 111   /* For the terminating NULL pointer.  */
 112   room_left -= sizeof (char *);
 113
 114   unsigned int i = 0;
 115   while (*line != '\0')
 116     {
 117       /* Skip leading blanks.  */
 118       while (isspace (*line))
 119         ++line;
 120
 121       if (*line == '\0')
 122         break;
 123
 124       if (room_left < sizeof (char *))
 125         goto no_more_room;
 126
 127       room_left -= sizeof (char *);
 128       network->n_aliases[i++] = line;
 129
 130       while (*line != '\0' && *line != ' ')
 131         ++line;
 132
 133       if (*line == ' ')
 134         *line++ = '\0';
 135     }
 136   network->n_aliases[i] = NULL;
 137
 138   return 1;
 139 }
 140
 141
 142 static enum nss_status
 143 _nss_create_tablename (int *errnop)
 144 {
 145   if (tablename_val == NULL)
 146     {
 147       const char *local_dir = nis_local_directory ();
 148       size_t local_dir_len = strlen (local_dir);
 149       static const char prefix[] = "networks.org_dir.";
 150
 151       char *p = malloc (sizeof (prefix) + local_dir_len);
 152       if (p == NULL)
 153         {
 154           *errnop = errno;
 155           return NSS_STATUS_TRYAGAIN;
 156         }
 157
 158       memcpy (__stpcpy (p, prefix), local_dir, local_dir_len + 1);
 159
 160       tablename_len = sizeof (prefix) - 1 + local_dir_len;
 161
 162       atomic_write_barrier ();
 163
 164       tablename_val = p;
 165     }
 166
 167   return NSS_STATUS_SUCCESS;
 168 }
 169
 170 enum nss_status
 171 _nss_nisplus_setnetent (int stayopen)
 172 {
 173   enum nss_status status = NSS_STATUS_SUCCESS;
 174
 175   __libc_lock_lock (lock);
 176
 177   if (result != NULL)
 178     {
 179       nis_freeresult (result);
 180       result = NULL;
 181     }
 182
 183   if (tablename_val == NULL)
 184     {
 185       int err;
 186       status = _nss_create_tablename (&err);
 187     }
 188
 189   __libc_lock_unlock (lock);
 190
 191   return status;
 192 }
 193
 194 enum nss_status
 195 _nss_nisplus_endnetent (void)
 196 {
 197   __libc_lock_lock (lock);
 198
 199   if (result != NULL)
 200     {
 201       nis_freeresult (result);
 202       result = NULL;
 203     }
 204
 205   __libc_lock_unlock (lock);
 206
 207   return NSS_STATUS_SUCCESS;
 208 }
 209
 210 static enum nss_status
 211 internal_nisplus_getnetent_r (struct netent *network, char *buffer,
 212                                size_t buflen, int *errnop, int *herrnop)
 213 {
 214   int parse_res;
 215
 216   /* Get the next entry until we found a correct one. */
 217   do
 218     {
 219       nis_result *saved_res;
 220
 221       if (result == NULL)
 222         {
 223           saved_res = NULL;
 224
 225           if (tablename_val == NULL)
 226             {
 227               enum nss_status status = _nss_create_tablename (errnop);
 228
 229               if (status != NSS_STATUS_SUCCESS)
 230                 return status;
 231             }
 232
 233           result = nis_first_entry (tablename_val);
 234           if (result == NULL)
 235             {
 236               *errnop = errno;
 237               return NSS_STATUS_TRYAGAIN;
 238             }
 239           if (niserr2nss (result->status) != NSS_STATUS_SUCCESS)
 240             {
 241               int retval = niserr2nss (result->status);
 242               nis_freeresult (result);
 243               result = NULL;
 244               if (retval == NSS_STATUS_TRYAGAIN)
 245                 {
 246                   *herrnop = NETDB_INTERNAL;
 247                   *errnop = errno;
 248                   return retval;
 249                 }
 250               else
 251                 return retval;
 252             }
 253         }
 254       else
 255         {
 256           saved_res = result;
 257           result = nis_next_entry (tablename_val, &result->cookie);
 258           if (result == NULL)
 259             {
 260               *errnop = errno;
 261               return NSS_STATUS_TRYAGAIN;
 262             }
 263           if (niserr2nss (result->status) != NSS_STATUS_SUCCESS)
 264             {
 265               int retval = niserr2nss (result->status);
 266               nis_freeresult (result);
 267               result = saved_res;
 268               if (retval == NSS_STATUS_TRYAGAIN)
 269                 {
 270                   *herrnop = NETDB_INTERNAL;
 271                   *errnop = errno;
 272                 }
 273               return retval;
 274             }
 275         }
 276
 277       parse_res = _nss_nisplus_parse_netent (result, network, buffer,
 278                                              buflen, errnop);
 279       if (parse_res == -1)
 280         {
 281           *herrnop = NETDB_INTERNAL;
 282           return NSS_STATUS_TRYAGAIN;
 283         }
 284
 285     }
 286   while (!parse_res);
 287
 288   return NSS_STATUS_SUCCESS;
 289 }
 290
 291 enum nss_status
 292 _nss_nisplus_getnetent_r (struct netent *result, char *buffer,
 293                            size_t buflen, int *errnop, int *herrnop)
 294 {
 295   int status;
 296
 297   __libc_lock_lock (lock);
 298
 299   status = internal_nisplus_getnetent_r (result, buffer, buflen, errnop,
 300                                          herrnop);
 301
 302   __libc_lock_unlock (lock);
 303
 304   return status;
 305 }
 306
 307 enum nss_status
 308 _nss_nisplus_getnetbyname_r (const char *name, struct netent *network,
 309                               char *buffer, size_t buflen, int *errnop,
 310                              int *herrnop)
 311 {
 312   int parse_res, retval;
 313
 314   if (tablename_val == NULL)
 315     {
 316       __libc_lock_lock (lock);
 317
 318       enum nss_status status = _nss_create_tablename (errnop);
 319
 320       __libc_lock_unlock (lock);
 321
 322       if (status != NSS_STATUS_SUCCESS)
 323         return status;
 324     }
 325
 326   if (name == NULL)
 327     {
 328       *errnop = EINVAL;
 329       *herrnop = NETDB_INTERNAL;
 330       return NSS_STATUS_UNAVAIL;
 331     }
 332
 333   nis_result *result;
 334   char buf[strlen (name) + 10 + tablename_len];
 335   int olderr = errno;
 336
 337   /* Search at first in the alias list, and use the correct name
 338      for the next search */
 339   snprintf (buf, sizeof (buf), "[name=%s],%s", name, tablename_val);
 340   result = nis_list (buf, FOLLOW_LINKS | FOLLOW_PATH | USE_DGRAM, NULL, NULL);
 341
 342   if (result != NULL)
 343     {
 344       char *bufptr = buf;
 345
 346       /* If we do not find it, try it as original name. But if the
 347          database is correct, we should find it in the first case, too */
 348       if ((result->status != NIS_SUCCESS
 349            && result->status != NIS_S_SUCCESS)
 350           || __type_of (result->objects.objects_val) != NIS_ENTRY_OBJ
 351           || strcmp (result->objects.objects_val[0].EN_data.en_type,
 352                      "networks_tbl") != 0
 353           || (result->objects.objects_val[0].EN_data.en_cols.en_cols_len
 354               < 3))
 355         snprintf (buf, sizeof (buf), "[cname=%s],%s", name, tablename_val);
 356       else
 357         {
 358           /* We need to allocate a new buffer since there is no
 359              guarantee the returned name has a length limit.  */
 360           const char *entryval = NISENTRYVAL (0, 0, result);
 361           size_t buflen = strlen (entryval) + 10 + tablename_len;
 362           bufptr = alloca (buflen);
 363           snprintf (bufptr, buflen, "[cname=%s],%s",
 364                     entryval, tablename_val);
 365         }
 366
 367       nis_freeresult (result);
 368       result = nis_list (bufptr, FOLLOW_LINKS | FOLLOW_PATH | USE_DGRAM,
 369                          NULL, NULL);
 370     }
 371
 372   if (result == NULL)
 373     {
 374       __set_errno (ENOMEM);
 375       return NSS_STATUS_TRYAGAIN;
 376     }
 377
 378   retval = niserr2nss (result->status);
 379   if (__glibc_unlikely (retval != NSS_STATUS_SUCCESS))
 380     {
 381       if (retval == NSS_STATUS_TRYAGAIN)
 382         {
 383           *errnop = errno;
 384           *herrnop = NETDB_INTERNAL;
 385         }
 386       else
 387         __set_errno (olderr);
 388       nis_freeresult (result);
 389       return retval;
 390     }
 391
 392   parse_res = _nss_nisplus_parse_netent (result, network, buffer, buflen,
 393                                          errnop);
 394
 395   nis_freeresult (result);
 396
 397   if (parse_res > 0)
 398     return NSS_STATUS_SUCCESS;
 399
 400   *herrnop = NETDB_INTERNAL;
 401   if (parse_res == -1)
 402     {
 403       *errnop = ERANGE;
 404       return NSS_STATUS_TRYAGAIN;
 405     }
 406
 407   __set_errno (olderr);
 408   return NSS_STATUS_NOTFOUND;
 409 }
 410
 411 /* XXX type is ignored, SUN's NIS+ table doesn't support it */
 412 enum nss_status
 413 _nss_nisplus_getnetbyaddr_r (uint32_t addr, const int type,
 414                              struct netent *network, char *buffer,
 415                              size_t buflen, int *errnop, int *herrnop)
 416 {
 417   if (tablename_val == NULL)
 418     {
 419       __libc_lock_lock (lock);
 420
 421       enum nss_status status = _nss_create_tablename (errnop);
 422
 423       __libc_lock_unlock (lock);
 424
 425       if (status != NSS_STATUS_SUCCESS)
 426         return status;
 427     }
 428
 429   {
 430     char buf[27 + tablename_len];
 431     char buf2[18];
 432     int olderr = errno;
 433
 434     struct in_addr in = { .s_addr = htonl (addr) };
 435     strcpy (buf2, inet_ntoa (in));
 436     size_t b2len = strlen (buf2);
 437
 438     while (1)
 439       {
 440         snprintf (buf, sizeof (buf), "[addr=%s],%s", buf2, tablename_val);
 441         nis_result *result = nis_list (buf, EXPAND_NAME | USE_DGRAM,
 442                                        NULL, NULL);
 443
 444         if (result == NULL)
 445           {
 446             __set_errno (ENOMEM);
 447             return NSS_STATUS_TRYAGAIN;
 448           }
 449         enum nss_status retval = niserr2nss (result->status);
 450         if (__glibc_unlikely (retval != NSS_STATUS_SUCCESS))
 451           {
 452             if (b2len > 2 && buf2[b2len - 2] == '.' && buf2[b2len - 1] == '0')
 453               {
 454                 /* Try again, but with trailing dot(s)
 455                    removed (one by one) */
 456                 buf2[b2len - 2] = '\0';
 457                 b2len -= 2;
 458                 nis_freeresult (result);
 459                 continue;
 460               }
 461
 462             if (retval == NSS_STATUS_TRYAGAIN)
 463               {
 464                 *errnop = errno;
 465                 *herrnop = NETDB_INTERNAL;
 466               }
 467             else
 468               __set_errno (olderr);
 469             nis_freeresult (result);
 470             return retval;
 471           }
 472
 473         int parse_res = _nss_nisplus_parse_netent (result, network, buffer,
 474                                                    buflen, errnop);
 475
 476         nis_freeresult (result);
 477
 478         if (parse_res > 0)
 479           return NSS_STATUS_SUCCESS;
 480
 481         *herrnop = NETDB_INTERNAL;
 482         if (parse_res == -1)
 483           {
 484             *errnop = ERANGE;
 485             return NSS_STATUS_TRYAGAIN;
 486           }
 487         else
 488           {
 489             __set_errno (olderr);
 490             return NSS_STATUS_NOTFOUND;
 491           }
 492       }
 493   }
 494 }