nss/nss_db/db-netgrp.c

   1 /* Netgroup file parser in nss_db modules.
   2    Copyright (C) 1996, 1997, 1999, 2000, 2011 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 <bits/libc-lock.h>
  27 #include <paths.h>
  28
  29 #include "nsswitch.h"
  30 #include "nss_db.h"
  31
  32 /* The hashing function we use.  */
  33 #include "../intl/hash-string.h"
  34
  35
  36 #define DBFILE          _PATH_VARDB "netgroup.db"
  37 \f
  38 /* Maintenance of the shared handle open on the database.  */
  39 enum nss_status
  40 _nss_db_setnetgrent (const char *group, struct __netgrent *result)
  41 {
  42   struct nss_db_map state;
  43   enum nss_status status = internal_setent (DBFILE, &state);
  44
  45   if (status == NSS_STATUS_SUCCESS)
  46     {
  47       const struct nss_db_header *header = state.header;
  48       const stridx_t *hashtable
  49         = (const stridx_t *) ((const char *) header
  50                               + header->dbs[0].hashoffset);
  51       const char *valstrtab = (const char *) header + header->valstroffset;
  52       uint32_t hashval = __hash_string (group);
  53       size_t grouplen = strlen (group);
  54       size_t hidx = hashval % header->dbs[0].hashsize;
  55       size_t hval2 = 1 + hashval % (header->dbs[0].hashsize - 2);
  56
  57       status = NSS_STATUS_NOTFOUND;
  58       while (hashtable[hidx] != ~((stridx_t) 0))
  59         {
  60           const char *valstr = valstrtab + hashtable[hidx];
  61
  62           if (strncmp (valstr, group, grouplen) == 0
  63               && isblank (valstr[grouplen]))
  64             {
  65               const char *cp = &valstr[grouplen + 1];
  66               while (isblank (*cp))
  67                 ++cp;
  68               if (*cp != '\0')
  69                 {
  70                   result->data = strdup (cp);
  71                   if (result->data == NULL)
  72                     status = NSS_STATUS_TRYAGAIN;
  73                   else
  74                     {
  75                       status = NSS_STATUS_SUCCESS;
  76                       result->cursor = result->data;
  77                     }
  78                   break;
  79                 }
  80             }
  81
  82           if ((hidx += hval2) >= header->dbs[0].hashsize)
  83             hidx -= header->dbs[0].hashsize;
  84         }
  85
  86       internal_endent (&state);
  87     }
  88
  89   return status;
  90
  91 }
  92
  93
  94 enum nss_status
  95 _nss_db_endnetgrent (struct __netgrent *result)
  96 {
  97   free (result->data);
  98   result->data = NULL;
  99   result->data_size = 0;
 100   result->cursor = NULL;
 101   return NSS_STATUS_SUCCESS;
 102 }
 103
 104
 105 extern enum nss_status _nss_netgroup_parseline (char **cursor,
 106                                                 struct __netgrent *result,
 107                                                 char *buffer, size_t buflen,
 108                                                 int *errnop);
 109
 110 enum nss_status
 111 _nss_db_getnetgrent_r (struct __netgrent *result, char *buffer, size_t buflen,
 112                        int *errnop)
 113 {
 114   enum nss_status status;
 115
 116   status = _nss_netgroup_parseline (&result->cursor, result, buffer, buflen,
 117                                     errnop);
 118
 119   return status;
 120 }