1  /* Netgroup file parser in nss_db modules.
       2     Copyright (C) 1996-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       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     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <ctype.h>
      20  #include <dlfcn.h>
      21  #include <errno.h>
      22  #include <fcntl.h>
      23  #include <netgroup.h>
      24  #include <string.h>
      25  #include <stdint.h>
      26  #include <libc-lock.h>
      27  #include <paths.h>
      28  #include <stdlib.h>
      29  
      30  #include "nsswitch.h"
      31  #include "nss_db.h"
      32  
      33  /* The hashing function we use.  */
      34  #include "../intl/hash-string.h"
      35  
      36  
      37  #define DBFILE		_PATH_VARDB "netgroup.db"
      38  
      39  /* Maintenance of the shared handle open on the database.  */
      40  enum nss_status
      41  _nss_db_setnetgrent (const char *group, struct __netgrent *result)
      42  {
      43    struct nss_db_map state;
      44    enum nss_status status = internal_setent (DBFILE, &state);
      45  
      46    if (status == NSS_STATUS_SUCCESS)
      47      {
      48        const struct nss_db_header *header = state.header;
      49        const stridx_t *hashtable
      50  	= (const stridx_t *) ((const char *) header
      51  			      + header->dbs[0].hashoffset);
      52        const char *valstrtab = (const char *) header + header->valstroffset;
      53        uint32_t hashval = __hash_string (group);
      54        size_t grouplen = strlen (group);
      55        size_t hidx = hashval % header->dbs[0].hashsize;
      56        size_t hval2 = 1 + hashval % (header->dbs[0].hashsize - 2);
      57  
      58        status = NSS_STATUS_NOTFOUND;
      59        while (hashtable[hidx] != ~((stridx_t) 0))
      60  	{
      61  	  const char *valstr = valstrtab + hashtable[hidx];
      62  
      63  	  if (strncmp (valstr, group, grouplen) == 0
      64  	      && isblank (valstr[grouplen]))
      65  	    {
      66  	      const char *cp = &valstr[grouplen + 1];
      67  	      while (isblank (*cp))
      68  		++cp;
      69  	      if (*cp != '\0')
      70  		{
      71  		  result->data = strdup (cp);
      72  		  if (result->data == NULL)
      73  		    status = NSS_STATUS_TRYAGAIN;
      74  		  else
      75  		    {
      76  		      status = NSS_STATUS_SUCCESS;
      77  		      result->cursor = result->data;
      78  		    }
      79  		  break;
      80  		}
      81  	    }
      82  
      83  	  if ((hidx += hval2) >= header->dbs[0].hashsize)
      84  	    hidx -= header->dbs[0].hashsize;
      85  	}
      86  
      87        internal_endent (&state);
      88      }
      89  
      90    return status;
      91  
      92  }
      93  
      94  
      95  enum nss_status
      96  _nss_db_endnetgrent (struct __netgrent *result)
      97  {
      98    free (result->data);
      99    result->data = NULL;
     100    result->data_size = 0;
     101    result->cursor = NULL;
     102    return NSS_STATUS_SUCCESS;
     103  }
     104  
     105  
     106  extern enum nss_status _nss_netgroup_parseline (char **cursor,
     107  						struct __netgrent *result,
     108  						char *buffer, size_t buflen,
     109  						int *errnop);
     110  
     111  enum nss_status
     112  _nss_db_getnetgrent_r (struct __netgrent *result, char *buffer, size_t buflen,
     113  		       int *errnop)
     114  {
     115    enum nss_status status;
     116  
     117    status = _nss_netgroup_parseline (&result->cursor, result, buffer, buflen,
     118  				    errnop);
     119  
     120    return status;
     121  }