nis/nss_nisplus/nisplus-rpc.c

   1 /* Copyright (C) 1997-2017 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3    Contributed by Thorsten Kukuk <kukuk@vt.uni-paderborn.de>, 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 <nss.h>
  23 #include <string.h>
  24 #include <rpc/netdb.h>
  25 #include <rpcsvc/nis.h>
  26 #include <libc-lock.h>
  27
  28 #include "nss-nisplus.h"
  29
  30 __libc_lock_define_initialized (static, lock)
  31
  32 static nis_result *result;
  33 static nis_name tablename_val;
  34 static u_long tablename_len;
  35
  36 #define NISENTRYVAL(idx, col, res) \
  37         (NIS_RES_OBJECT (res)[idx].EN_data.en_cols.en_cols_val[col].ec_value.ec_value_val)
  38
  39 #define NISENTRYLEN(idx, col, res) \
  40         (NIS_RES_OBJECT (res)[idx].EN_data.en_cols.en_cols_val[col].ec_value.ec_value_len)
  41
  42
  43 static int
  44 _nss_nisplus_parse_rpcent (nis_result *result, struct rpcent *rpc,
  45                            char *buffer, size_t buflen, int *errnop)
  46 {
  47   char *first_unused = buffer;
  48   size_t room_left = buflen;
  49   unsigned int i;
  50   char *line;
  51
  52
  53   if (result == NULL)
  54     return 0;
  55
  56   if ((result->status != NIS_SUCCESS && result->status != NIS_S_SUCCESS)
  57       || __type_of (NIS_RES_OBJECT (result)) != NIS_ENTRY_OBJ
  58       || strcmp (NIS_RES_OBJECT (result)[0].EN_data.en_type, "rpc_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     no_more_room:
  65       *errnop = ERANGE;
  66       return -1;
  67     }
  68   strncpy (first_unused, NISENTRYVAL (0, 0, result),
  69            NISENTRYLEN (0, 0, result));
  70   first_unused[NISENTRYLEN (0, 0, result)] = '\0';
  71   rpc->r_name = first_unused;
  72   size_t len = strlen (first_unused) + 1;
  73   room_left -= len;
  74   first_unused += len;
  75
  76   rpc->r_number = atoi (NISENTRYVAL (0, 2, result));
  77
  78   /* XXX Rewrite at some point to allocate the array first and then
  79      copy the strings.  It wasteful to first concatenate the strings
  80      to just split them again later.  */
  81   line = first_unused;
  82   for (i = 0; i < NIS_RES_NUMOBJ (result); ++i)
  83     {
  84       if (strcmp (NISENTRYVAL (i, 1, result), rpc->r_name) != 0)
  85         {
  86           if (NISENTRYLEN (i, 1, result) + 2 > room_left)
  87             goto no_more_room;
  88           *first_unused++ = ' ';
  89           first_unused = __stpncpy (first_unused, NISENTRYVAL (i, 1, result),
  90                                     NISENTRYLEN (i, 1, result));
  91           room_left -= NISENTRYLEN (i, 1, result) + 1;
  92         }
  93     }
  94   *first_unused++ = '\0';
  95
  96   /* Adjust the pointer so it is aligned for
  97      storing pointers.  */
  98   size_t adjust = ((__alignof__ (char *)
  99                     - (first_unused - (char *) 0) % __alignof__ (char *))
 100                    % __alignof__ (char *));
 101   if (room_left < adjust + sizeof (char *))
 102     goto no_more_room;
 103   first_unused += adjust;
 104   room_left -= adjust;
 105   rpc->r_aliases = (char **) first_unused;
 106
 107   /* For the terminating NULL pointer.  */
 108   room_left -= sizeof (char *);
 109
 110   i = 0;
 111   while (*line != '\0')
 112     {
 113       /* Skip leading blanks.  */
 114       while (isspace (*line))
 115         ++line;
 116
 117       if (*line == '\0')
 118         break;
 119
 120       if (room_left < sizeof (char *))
 121         goto no_more_room;
 122
 123       room_left -= sizeof (char *);
 124       rpc->r_aliases[i++] = line;
 125
 126       while (*line != '\0' && *line != ' ')
 127         ++line;
 128
 129       if (*line == ' ')
 130         *line++ = '\0';
 131     }
 132   rpc->r_aliases[i] = NULL;
 133
 134   return 1;
 135 }
 136
 137
 138 static enum nss_status
 139 _nss_create_tablename (int *errnop)
 140 {
 141   if (tablename_val == NULL)
 142     {
 143       const char *local_dir = nis_local_directory ();
 144       size_t local_dir_len = strlen (local_dir);
 145       static const char prefix[] = "rpc.org_dir.";
 146
 147       char *p = malloc (sizeof (prefix) + local_dir_len);
 148       if (p == NULL)
 149         {
 150           *errnop = errno;
 151           return NSS_STATUS_TRYAGAIN;
 152         }
 153
 154       memcpy (__stpcpy (p, prefix), local_dir, local_dir_len + 1);
 155
 156       tablename_len = sizeof (prefix) - 1 + local_dir_len;
 157
 158       atomic_write_barrier ();
 159
 160       tablename_val = p;
 161     }
 162
 163   return NSS_STATUS_SUCCESS;
 164 }
 165
 166
 167 enum nss_status
 168 _nss_nisplus_setrpcent (int stayopen)
 169 {
 170   enum nss_status status = NSS_STATUS_SUCCESS;
 171
 172   __libc_lock_lock (lock);
 173
 174   if (result != NULL)
 175     {
 176       nis_freeresult (result);
 177       result = NULL;
 178     }
 179
 180   if (tablename_val == NULL)
 181     {
 182       int err;
 183       status = _nss_create_tablename (&err);
 184     }
 185
 186   __libc_lock_unlock (lock);
 187
 188   return status;
 189 }
 190
 191 enum nss_status
 192 _nss_nisplus_endrpcent (void)
 193 {
 194   __libc_lock_lock (lock);
 195
 196   if (result != NULL)
 197     {
 198       nis_freeresult (result);
 199       result = NULL;
 200     }
 201
 202   __libc_lock_unlock (lock);
 203
 204   return NSS_STATUS_SUCCESS;
 205 }
 206
 207 static enum nss_status
 208 internal_nisplus_getrpcent_r (struct rpcent *rpc, char *buffer,
 209                               size_t buflen, int *errnop)
 210 {
 211   int parse_res;
 212
 213   /* Get the next entry until we found a correct one. */
 214   do
 215     {
 216       nis_result *saved_res;
 217
 218       if (result == NULL)
 219         {
 220           saved_res = NULL;
 221           if (tablename_val == NULL)
 222             {
 223               enum nss_status status =  _nss_create_tablename (errnop);
 224
 225               if (status != NSS_STATUS_SUCCESS)
 226                 return status;
 227             }
 228
 229           result = nis_first_entry (tablename_val);
 230           if (result == NULL)
 231             {
 232               *errnop = errno;
 233               return NSS_STATUS_TRYAGAIN;
 234             }
 235           if (niserr2nss (result->status) != NSS_STATUS_SUCCESS)
 236             return niserr2nss (result->status);
 237         }
 238       else
 239         {
 240           saved_res = result;
 241           result = nis_next_entry (tablename_val, &result->cookie);
 242           if (result == NULL)
 243             {
 244               *errnop = errno;
 245               return NSS_STATUS_TRYAGAIN;
 246             }
 247           if (niserr2nss (result->status) != NSS_STATUS_SUCCESS)
 248             {
 249               nis_freeresult (saved_res);
 250               return niserr2nss (result->status);
 251             }
 252         }
 253
 254       parse_res = _nss_nisplus_parse_rpcent (result, rpc, buffer,
 255                                              buflen, errnop);
 256       if (parse_res == -1)
 257         {
 258           nis_freeresult (result);
 259           result = saved_res;
 260           *errnop = ERANGE;
 261           return NSS_STATUS_TRYAGAIN;
 262         }
 263       else
 264         {
 265           if (saved_res)
 266             nis_freeresult (saved_res);
 267         }
 268     }
 269   while (!parse_res);
 270
 271   return NSS_STATUS_SUCCESS;
 272 }
 273
 274 enum nss_status
 275 _nss_nisplus_getrpcent_r (struct rpcent *result, char *buffer,
 276                           size_t buflen, int *errnop)
 277 {
 278   int status;
 279
 280   __libc_lock_lock (lock);
 281
 282   status = internal_nisplus_getrpcent_r (result, buffer, buflen, errnop);
 283
 284   __libc_lock_unlock (lock);
 285
 286   return status;
 287 }
 288
 289 enum nss_status
 290 _nss_nisplus_getrpcbyname_r (const char *name, struct rpcent *rpc,
 291                              char *buffer, size_t buflen, int *errnop)
 292 {
 293   int parse_res;
 294
 295   if (tablename_val == NULL)
 296     {
 297       __libc_lock_lock (lock);
 298
 299       enum nss_status status = _nss_create_tablename (errnop);
 300
 301       __libc_lock_unlock (lock);
 302
 303       if (status != NSS_STATUS_SUCCESS)
 304         return status;
 305     }
 306
 307   if (name == NULL)
 308     return NSS_STATUS_NOTFOUND;
 309
 310   char buf[strlen (name) + 10 + tablename_len];
 311   int olderr = errno;
 312
 313   /* Search at first in the alias list, and use the correct name
 314      for the next search */
 315   snprintf (buf, sizeof (buf), "[name=%s],%s", name, tablename_val);
 316   nis_result *result = nis_list (buf, FOLLOW_PATH | FOLLOW_LINKS | USE_DGRAM,
 317                                  NULL, NULL);
 318
 319   if (result != NULL)
 320     {
 321       char *bufptr = buf;
 322
 323       /* If we did not find it, try it as original name. But if the
 324          database is correct, we should find it in the first case, too */
 325       if ((result->status != NIS_SUCCESS
 326            && result->status != NIS_S_SUCCESS)
 327           || __type_of (result->objects.objects_val) != NIS_ENTRY_OBJ
 328           || strcmp (result->objects.objects_val->EN_data.en_type,
 329                      "rpc_tbl") != 0
 330           || result->objects.objects_val->EN_data.en_cols.en_cols_len < 3)
 331         snprintf (buf, sizeof (buf), "[cname=%s],%s", name, tablename_val);
 332       else
 333         {
 334           /* We need to allocate a new buffer since there is no
 335              guarantee the returned name has a length limit.  */
 336           const char *entryval = NISENTRYVAL (0, 0, result);
 337           size_t buflen = strlen (entryval) + 10 + tablename_len;
 338           bufptr = alloca (buflen);
 339           snprintf (bufptr, buflen, "[cname=%s],%s",
 340                     entryval, tablename_val);
 341         }
 342
 343       nis_freeresult (result);
 344       result = nis_list (bufptr, FOLLOW_PATH | FOLLOW_LINKS | USE_DGRAM,
 345                          NULL, NULL);
 346     }
 347
 348   if (result == NULL)
 349     {
 350       *errnop = ENOMEM;
 351       return NSS_STATUS_TRYAGAIN;
 352     }
 353
 354   if (__glibc_unlikely (niserr2nss (result->status) != NSS_STATUS_SUCCESS))
 355     {
 356       enum nss_status status = niserr2nss (result->status);
 357
 358       __set_errno (olderr);
 359
 360       nis_freeresult (result);
 361       return status;
 362     }
 363
 364   parse_res = _nss_nisplus_parse_rpcent (result, rpc, buffer, buflen,
 365                                              errnop);
 366
 367   nis_freeresult (result);
 368
 369   if (parse_res < 1)
 370     {
 371       if (parse_res == -1)
 372         {
 373           *errnop = ERANGE;
 374           return NSS_STATUS_TRYAGAIN;
 375         }
 376
 377       __set_errno (olderr);
 378       return NSS_STATUS_NOTFOUND;
 379     }
 380
 381   return NSS_STATUS_SUCCESS;
 382 }
 383
 384 enum nss_status
 385 _nss_nisplus_getrpcbynumber_r (const int number, struct rpcent *rpc,
 386                                char *buffer, size_t buflen, int *errnop)
 387 {
 388   if (tablename_val == NULL)
 389     {
 390       __libc_lock_lock (lock);
 391
 392       enum nss_status status = _nss_create_tablename (errnop);
 393
 394       __libc_lock_unlock (lock);
 395
 396       if (status != NSS_STATUS_SUCCESS)
 397         return status;
 398     }
 399
 400   char buf[12 + 3 * sizeof (number) + tablename_len];
 401   int olderr = errno;
 402
 403   snprintf (buf, sizeof (buf), "[number=%d],%s", number, tablename_val);
 404
 405   nis_result *result = nis_list (buf, FOLLOW_LINKS | FOLLOW_PATH | USE_DGRAM,
 406                                  NULL, NULL);
 407
 408   if (result == NULL)
 409     {
 410       *errnop = ENOMEM;
 411       return NSS_STATUS_TRYAGAIN;
 412     }
 413
 414   if (__builtin_expect (niserr2nss (result->status) != NSS_STATUS_SUCCESS,  0))
 415     {
 416       enum nss_status status = niserr2nss (result->status);
 417
 418       __set_errno (olderr);
 419
 420       nis_freeresult (result);
 421       return status;
 422     }
 423
 424   int parse_res = _nss_nisplus_parse_rpcent (result, rpc, buffer, buflen,
 425                                              errnop);
 426
 427   nis_freeresult (result);
 428
 429   if (parse_res < 1)
 430     {
 431       if (parse_res == -1)
 432         {
 433           *errnop = ERANGE;
 434           return NSS_STATUS_TRYAGAIN;
 435         }
 436       else
 437         {
 438           __set_errno (olderr);
 439           return NSS_STATUS_NOTFOUND;
 440         }
 441     }
 442
 443   return NSS_STATUS_SUCCESS;
 444 }