external/bsd/openldap/dist/servers/slapd/lock.c

   1 /* lock.c - routines to open and apply an advisory lock to a file */
   2 /* $OpenLDAP: pkg/ldap/servers/slapd/lock.c,v 1.32.2.3 2008/02/11 23:26:44 kurt Exp $ */
   3 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
   4  *
   5  * Copyright 1998-2008 The OpenLDAP Foundation.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted only as authorized by the OpenLDAP
  10  * Public License.
  11  *
  12  * A copy of this license is available in the file LICENSE in the
  13  * top-level directory of the distribution or, alternatively, at
  14  * <http://www.OpenLDAP.org/license.html>.
  15  */
  16 /* Portions Copyright (c) 1995 Regents of the University of Michigan.
  17  * All rights reserved.
  18  *
  19  * Redistribution and use in source and binary forms are permitted
  20  * provided that this notice is preserved and that due credit is given
  21  * to the University of Michigan at Ann Arbor. The name of the University
  22  * may not be used to endorse or promote products derived from this
  23  * software without specific prior written permission. This software
  24  * is provided ``as is'' without express or implied warranty.
  25  */
  26
  27 #include "portable.h"
  28
  29 #include <stdio.h>
  30
  31 #include <ac/string.h>
  32 #include <ac/socket.h>
  33 #include <ac/time.h>
  34 #include <ac/unistd.h>
  35
  36 #ifdef HAVE_SYS_FILE_H
  37 #include <sys/file.h>
  38 #endif
  39
  40 #include "slap.h"
  41 #include <lutil.h>
  42
  43 FILE *
  44 lock_fopen( const char *fname, const char *type, FILE **lfp )
  45 {
  46         FILE    *fp;
  47         char    buf[MAXPATHLEN];
  48
  49         /* open the lock file */
  50         snprintf( buf, sizeof buf, "%s.lock", fname );
  51
  52         if ( (*lfp = fopen( buf, "w" )) == NULL ) {
  53                 Debug( LDAP_DEBUG_ANY, "could not open \"%s\"\n", buf, 0, 0 );
  54
  55                 return( NULL );
  56         }
  57
  58         /* acquire the lock */
  59         ldap_lockf( fileno(*lfp) );
  60
  61         /* open the log file */
  62         if ( (fp = fopen( fname, type )) == NULL ) {
  63                 Debug( LDAP_DEBUG_ANY, "could not open \"%s\"\n", fname, 0, 0 );
  64
  65                 ldap_unlockf( fileno(*lfp) );
  66                 fclose( *lfp );
  67                 *lfp = NULL;
  68                 return( NULL );
  69         }
  70
  71         return( fp );
  72 }
  73
  74 int
  75 lock_fclose( FILE *fp, FILE *lfp )
  76 {
  77         int rc = fclose( fp );
  78         /* unlock */
  79         ldap_unlockf( fileno(lfp) );
  80         fclose( lfp );
  81
  82         return( rc );
  83 }