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

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