nis/nss_nisplus/nisplus-ethers.c

   1 /* Copyright (C) 1997-2015 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <atomic.h>
  20 #include <ctype.h>
  21 #include <errno.h>
  22 #include <inttypes.h>
  23 #include <netdb.h>
  24 #include <nss.h>
  25 #include <string.h>
  26 #include <netinet/ether.h>
  27 #include <netinet/if_ether.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
  40 #define NISENTRYVAL(idx, col, res) \
  41         (NIS_RES_OBJECT (res)[idx].zo_data.objdata_u.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].zo_data.objdata_u.en_data.en_cols.en_cols_val[col].ec_value.ec_value_len)
  45
  46 static int
  47 _nss_nisplus_parse_etherent (nis_result *result, struct etherent *ether,
  48                              char *buffer, size_t buflen, int *errnop)
  49 {
  50   char *p = buffer;
  51   size_t room_left = buflen;
  52
  53   if (result == NULL)
  54     return 0;
  55
  56   if ((result->status != NIS_SUCCESS && result->status != NIS_S_SUCCESS)
  57       || NIS_RES_NUMOBJ (result) != 1
  58       || __type_of (NIS_RES_OBJECT (result)) != NIS_ENTRY_OBJ
  59       || strcmp (NIS_RES_OBJECT (result)->EN_data.en_type,
  60                  "ethers_tbl") != 0
  61       || NIS_RES_OBJECT (result)->EN_data.en_cols.en_cols_len < 2)
  62     return 0;
  63
  64   /* Generate the ether entry format and use the normal parser */
  65   if (NISENTRYLEN (0, 0, result) + 1 > room_left)
  66     {
  67       *errnop = ERANGE;
  68       return -1;
  69     }
  70   char *cp = __stpncpy (p, NISENTRYVAL (0, 0, result),
  71                         NISENTRYLEN (0, 0, result));
  72   *cp = '\0';
  73   room_left -= NISENTRYLEN (0, 0, result) + 1;
  74   ether->e_name = p;
  75
  76   struct ether_addr *ea = ether_aton (NISENTRYVAL (0, 1, result));
  77   if (ea == NULL)
  78     {
  79       *errnop = EINVAL;
  80       return -2;
  81     }
  82
  83   ether->e_addr = *ea;
  84
  85   return 1;
  86 }
  87
  88 static enum nss_status
  89 _nss_create_tablename (int *errnop)
  90 {
  91   if (tablename_val == NULL)
  92     {
  93       const char *local_dir = nis_local_directory ();
  94       size_t local_dir_len = strlen (local_dir);
  95       static const char prefix[] = "ethers.org_dir.";
  96
  97       char *p = malloc (sizeof (prefix) + local_dir_len);
  98       if (p == NULL)
  99         {
 100           *errnop = errno;
 101           return NSS_STATUS_TRYAGAIN;
 102         }
 103
 104       memcpy (__stpcpy (p, prefix), local_dir, local_dir_len + 1);
 105
 106       tablename_len = sizeof (prefix) - 1 + local_dir_len;
 107
 108       atomic_write_barrier ();
 109
 110       tablename_val = p;
 111     }
 112   return NSS_STATUS_SUCCESS;
 113 }
 114
 115
 116 enum nss_status
 117 _nss_nisplus_setetherent (int stayopen)
 118 {
 119   enum nss_status status;
 120   int err;
 121
 122   status = NSS_STATUS_SUCCESS;
 123
 124   __libc_lock_lock (lock);
 125
 126   if (result != NULL)
 127     {
 128       nis_freeresult (result);
 129       result = NULL;
 130     }
 131
 132   if (_nss_create_tablename (&err) != NSS_STATUS_SUCCESS)
 133     status = NSS_STATUS_UNAVAIL;
 134
 135   __libc_lock_unlock (lock);
 136
 137   return status;
 138 }
 139
 140 enum nss_status
 141 _nss_nisplus_endetherent (void)
 142 {
 143   __libc_lock_lock (lock);
 144
 145   if (result != NULL)
 146     {
 147       nis_freeresult (result);
 148       result = NULL;
 149     }
 150
 151   __libc_lock_unlock (lock);
 152
 153   return NSS_STATUS_SUCCESS;
 154 }
 155
 156 static enum nss_status
 157 internal_nisplus_getetherent_r (struct etherent *ether, char *buffer,
 158                                 size_t buflen, int *errnop)
 159 {
 160   if (tablename_val == NULL)
 161     {
 162       enum nss_status status = _nss_create_tablename (errnop);
 163
 164       if (status != NSS_STATUS_SUCCESS)
 165         return status;
 166     }
 167
 168   /* Get the next entry until we found a correct one. */
 169   int parse_res;
 170   do
 171     {
 172       nis_result *saved_result;
 173
 174       if (result == NULL)
 175         {
 176           saved_result = NULL;
 177           result = nis_first_entry (tablename_val);
 178           if (result == NULL)
 179             {
 180               *errnop = errno;
 181               return NSS_STATUS_TRYAGAIN;
 182             }
 183           if (niserr2nss (result->status) != NSS_STATUS_SUCCESS)
 184             return niserr2nss (result->status);
 185         }
 186       else
 187         {
 188           saved_result = result;
 189           result = nis_next_entry (tablename_val, &result->cookie);
 190           if (result == NULL)
 191             {
 192               *errnop = errno;
 193               return NSS_STATUS_TRYAGAIN;
 194             }
 195           if (niserr2nss (result->status) != NSS_STATUS_SUCCESS)
 196             {
 197               nis_freeresult (saved_result);
 198               return niserr2nss (result->status);
 199             }
 200         }
 201
 202       parse_res = _nss_nisplus_parse_etherent (result, ether, buffer,
 203                                                buflen, errnop);
 204       if (parse_res == -1)
 205         {
 206           nis_freeresult (result);
 207           result = saved_result;
 208           return NSS_STATUS_TRYAGAIN;
 209         }
 210
 211       if (saved_result != NULL)
 212         nis_freeresult (saved_result);
 213
 214     }
 215   while (!parse_res);
 216
 217   return NSS_STATUS_SUCCESS;
 218 }
 219
 220 enum nss_status
 221 _nss_nisplus_getetherent_r (struct etherent *result, char *buffer,
 222                             size_t buflen, int *errnop)
 223 {
 224   int status;
 225
 226   __libc_lock_lock (lock);
 227
 228   status = internal_nisplus_getetherent_r (result, buffer, buflen, errnop);
 229
 230   __libc_lock_unlock (lock);
 231
 232   return status;
 233 }
 234
 235 enum nss_status
 236 _nss_nisplus_gethostton_r (const char *name, struct etherent *eth,
 237                            char *buffer, size_t buflen, int *errnop)
 238 {
 239   if (tablename_val == NULL)
 240     {
 241       enum nss_status status = _nss_create_tablename (errnop);
 242
 243       if (status != NSS_STATUS_SUCCESS)
 244         return status;
 245     }
 246
 247   if (name == NULL)
 248     {
 249       *errnop = EINVAL;
 250       return NSS_STATUS_UNAVAIL;
 251     }
 252
 253   char buf[strlen (name) + 9 + tablename_len];
 254   int olderr = errno;
 255
 256   snprintf (buf, sizeof (buf), "[name=%s],%s", name, tablename_val);
 257
 258   nis_result *result = nis_list (buf, FOLLOW_PATH | FOLLOW_LINKS | USE_DGRAM,
 259                                  NULL, NULL);
 260
 261   if (result == NULL)
 262     {
 263       *errnop = ENOMEM;
 264       return NSS_STATUS_TRYAGAIN;
 265     }
 266
 267   if (__glibc_unlikely (niserr2nss (result->status) != NSS_STATUS_SUCCESS))
 268     {
 269       enum nss_status status = niserr2nss (result->status);
 270       nis_freeresult (result);
 271       return status;
 272     }
 273
 274   int parse_res = _nss_nisplus_parse_etherent (result, eth, buffer,
 275                                                buflen, errnop);
 276
 277   /* We do not need the lookup result anymore.  */
 278   nis_freeresult (result);
 279
 280   if (__glibc_unlikely (parse_res < 1))
 281     {
 282       __set_errno (olderr);
 283
 284       if (parse_res == -1)
 285         return NSS_STATUS_TRYAGAIN;
 286
 287       return NSS_STATUS_NOTFOUND;
 288     }
 289
 290   return NSS_STATUS_SUCCESS;
 291 }
 292
 293 enum nss_status
 294 _nss_nisplus_getntohost_r (const struct ether_addr *addr, struct etherent *eth,
 295                            char *buffer, size_t buflen, int *errnop)
 296 {
 297   if (tablename_val == NULL)
 298     {
 299       __libc_lock_lock (lock);
 300
 301       enum nss_status status = _nss_create_tablename (errnop);
 302
 303       __libc_lock_unlock (lock);
 304
 305       if (status != NSS_STATUS_SUCCESS)
 306         return status;
 307     }
 308
 309   if (addr == NULL)
 310     {
 311       *errnop = EINVAL;
 312       return NSS_STATUS_UNAVAIL;
 313     }
 314
 315   char buf[26 + tablename_len];
 316
 317   snprintf (buf, sizeof (buf),
 318             "[addr=%" PRIx8 ":%" PRIx8 ":%" PRIx8 ":%" PRIx8 ":%" PRIx8
 319             ":%" PRIx8 "],%s",
 320             addr->ether_addr_octet[0], addr->ether_addr_octet[1],
 321             addr->ether_addr_octet[2], addr->ether_addr_octet[3],
 322             addr->ether_addr_octet[4], addr->ether_addr_octet[5],
 323             tablename_val);
 324
 325   nis_result *result = nis_list (buf, FOLLOW_PATH | FOLLOW_LINKS | USE_DGRAM,
 326                                  NULL, NULL);
 327
 328   if (result == NULL)
 329     {
 330       *errnop = ENOMEM;
 331       return NSS_STATUS_TRYAGAIN;
 332     }
 333
 334   if (__glibc_unlikely (niserr2nss (result->status) != NSS_STATUS_SUCCESS))
 335     {
 336       enum nss_status status = niserr2nss (result->status);
 337       nis_freeresult (result);
 338       return status;
 339     }
 340
 341   int parse_res = _nss_nisplus_parse_etherent (result, eth, buffer,
 342                                                buflen, errnop);
 343
 344   /* We do not need the lookup result anymore.  */
 345   nis_freeresult (result);
 346
 347   if (__glibc_unlikely (parse_res < 1))
 348     {
 349       if (parse_res == -1)
 350         return NSS_STATUS_TRYAGAIN;
 351
 352       return NSS_STATUS_NOTFOUND;
 353     }
 354
 355   return NSS_STATUS_SUCCESS;
 356 }