git.sur5r.net Git - openldap/blob - libraries/liblutil/detach.c

   1 /* $OpenLDAP$ */
   2 /*
   3  * Copyright 1998-2003 The OpenLDAP Foundation, All Rights Reserved.
   4  * COPYING RESTRICTIONS APPLY, see COPYRIGHT file
   5  */
   6 /*
   7  * Copyright (c) 1990, 1994 Regents of the University of Michigan.
   8  * All rights reserved.
   9  *
  10  * Redistribution and use in source and binary forms are permitted
  11  * provided that this notice is preserved and that due credit is given
  12  * to the University of Michigan at Ann Arbor. The name of the University
  13  * may not be used to endorse or promote products derived from this
  14  * software without specific prior written permission. This software
  15  * is provided ``as is'' without express or implied warranty.
  16  */
  17
  18 #include "portable.h"
  19
  20 #include <stdio.h>
  21
  22 #include <ac/stdlib.h>
  23 #include <ac/signal.h>
  24 #include <ac/socket.h>
  25 #include <ac/unistd.h>
  26
  27 #include <sys/stat.h>
  28 #include <fcntl.h>
  29
  30 #ifdef HAVE_SYS_FILE_H
  31 #include <sys/file.h>
  32 #endif
  33 #ifdef HAVE_SYS_IOCTL_H
  34 #include <sys/ioctl.h>
  35 #endif
  36
  37 #include "lutil.h"
  38
  39 void
  40 lutil_detach( int debug, int do_close )
  41 {
  42         int             i, sd, nbits;
  43
  44 #ifdef HAVE_SYSCONF
  45         nbits = sysconf( _SC_OPEN_MAX );
  46 #elif HAVE_GETDTABLESIZE
  47         nbits = getdtablesize();
  48 #else
  49         nbits = FD_SETSIZE;
  50 #endif
  51
  52 #ifdef FD_SETSIZE
  53         if ( nbits > FD_SETSIZE ) {
  54                 nbits = FD_SETSIZE;
  55         }
  56 #endif /* FD_SETSIZE */
  57
  58         if ( debug == 0 ) {
  59                 for ( i = 0; i < 5; i++ ) {
  60 #if HAVE_THR
  61                         switch ( fork1() )
  62 #else
  63                         switch ( fork() )
  64 #endif
  65                         {
  66                         case -1:
  67                                 sleep( 5 );
  68                                 continue;
  69
  70                         case 0:
  71                                 break;
  72
  73                         default:
  74                                 _exit( EXIT_SUCCESS );
  75                         }
  76                         break;
  77                 }
  78
  79                 if ( (sd = open( "/dev/null", O_RDWR   )) == -1 &&
  80                          (sd = open( "/dev/null", O_RDONLY )) == -1 &&
  81                          /* Panic -- open *something* */
  82                          (sd = open( "/",         O_RDONLY )) == -1    ) {
  83                         perror("/dev/null");
  84                 } else {
  85                         /* redirect stdin, stdout, stderr to /dev/null */
  86                         dup2( sd, STDIN_FILENO );
  87                         dup2( sd, STDOUT_FILENO );
  88                         dup2( sd, STDERR_FILENO );
  89
  90                         switch( sd ) {
  91                         default:
  92                                 close( sd );
  93                         case STDIN_FILENO:
  94                         case STDOUT_FILENO:
  95                         case STDERR_FILENO:
  96                                 break;
  97                         }
  98                 }
  99
 100                 if ( do_close ) {
 101                         /* close everything else */
 102                         for ( i = 0; i < nbits; i++ ) {
 103                                 if( i != STDIN_FILENO &&
 104                                         i != STDOUT_FILENO &&
 105                                         i != STDERR_FILENO )
 106                                 {
 107                                         close( i );
 108                                 }
 109                         }
 110                 }
 111
 112 #ifdef CHDIR_TO_ROOT
 113                 (void) chdir( "/" );
 114 #endif
 115
 116 #ifdef HAVE_SETSID
 117                 (void) setsid();
 118 #elif TIOCNOTTY
 119                 if ( (sd = open( "/dev/tty", O_RDWR )) != -1 ) {
 120                         (void) ioctl( sd, TIOCNOTTY, NULL );
 121                         (void) close( sd );
 122                 }
 123 #endif
 124         }
 125
 126 #ifdef SIGPIPE
 127         (void) SIGNAL( SIGPIPE, SIG_IGN );
 128 #endif
 129 }