nss/nss_db/db-netgrp.c

   1 /* Netgroup file parser in nss_db modules.
   2    Copyright (C) 1996-2014 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4    Contributed by Ulrich Drepper <drepper@cygnus.com>, 1996.
   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, see
  18    <http://www.gnu.org/licenses/>.  */
  19
  20 #include <ctype.h>
  21 #include <dlfcn.h>
  22 #include <errno.h>
  23 #include <fcntl.h>
  24 #include <netgroup.h>
  25 #include <string.h>
  26 #include <stdint.h>
  27 #include <bits/libc-lock.h>
  28 #include <paths.h>
  29 #include <stdlib.h>
  30
  31 #include "nsswitch.h"
  32 #include "nss_db.h"
  33
  34 /* The hashing function we use.  */
  35 #include "../intl/hash-string.h"
  36
  37
  38 #define DBFILE          _PATH_VARDB "netgroup.db"
  39 \f
  40 /* Maintenance of the shared handle open on the database.  */
  41 enum nss_status
  42 _nss_db_setnetgrent (const char *group, struct __netgrent *result)
  43 {
  44   struct nss_db_map state;
  45   enum nss_status status = internal_setent (DBFILE, &state);
  46
  47   if (status == NSS_STATUS_SUCCESS)
  48     {
  49       const struct nss_db_header *header = state.header;
  50       const stridx_t *hashtable
  51         = (const stridx_t *) ((const char *) header
  52                               + header->dbs[0].hashoffset);
  53       const char *valstrtab = (const char *) header + header->valstroffset;
  54       uint32_t hashval = __hash_string (group);
  55       size_t grouplen = strlen (group);
  56       size_t hidx = hashval % header->dbs[0].hashsize;
  57       size_t hval2 = 1 + hashval % (header->dbs[0].hashsize - 2);
  58
  59       status = NSS_STATUS_NOTFOUND;
  60       while (hashtable[hidx] != ~((stridx_t) 0))
  61         {
  62           const char *valstr = valstrtab + hashtable[hidx];
  63
  64           if (strncmp (valstr, group, grouplen) == 0
  65               && isblank (valstr[grouplen]))
  66             {
  67               const char *cp = &valstr[grouplen + 1];
  68               while (isblank (*cp))
  69                 ++cp;
  70               if (*cp != '\0')
  71                 {
  72                   result->data = strdup (cp);
  73                   if (result->data == NULL)
  74                     status = NSS_STATUS_TRYAGAIN;
  75                   else
  76                     {
  77                       status = NSS_STATUS_SUCCESS;
  78                       result->cursor = result->data;
  79                     }
  80                   break;
  81                 }
  82             }
  83
  84           if ((hidx += hval2) >= header->dbs[0].hashsize)
  85             hidx -= header->dbs[0].hashsize;
  86         }
  87
  88       internal_endent (&state);
  89     }
  90
  91   return status;
  92
  93 }
  94
  95
  96 enum nss_status
  97 _nss_db_endnetgrent (struct __netgrent *result)
  98 {
  99   free (result->data);
 100   result->data = NULL;
 101   result->data_size = 0;
 102   result->cursor = NULL;
 103   return NSS_STATUS_SUCCESS;
 104 }
 105
 106
 107 extern enum nss_status _nss_netgroup_parseline (char **cursor,
 108                                                 struct __netgrent *result,
 109                                                 char *buffer, size_t buflen,
 110                                                 int *errnop);
 111
 112 enum nss_status
 113 _nss_db_getnetgrent_r (struct __netgrent *result, char *buffer, size_t buflen,
 114                        int *errnop)
 115 {
 116   enum nss_status status;
 117
 118   status = _nss_netgroup_parseline (&result->cursor, result, buffer, buflen,
 119                                     errnop);
 120
 121   return status;
 122 }