/* $NetBSD: detach.c,v 1.5.6.1 2019/08/10 06:17:16 martin Exp $ */ /* detach.c -- routines to daemonize a process */ /* $OpenLDAP$ */ /* This work is part of OpenLDAP Software . * * Copyright 1998-2019 The OpenLDAP Foundation. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted only as authorized by the OpenLDAP * Public License. * * A copy of this license is available in the file LICENSE in the * top-level directory of the distribution or, alternatively, at * . */ /* * Copyright (c) 1990, 1994 Regents of the University of Michigan. * All rights reserved. * * Redistribution and use in source and binary forms are permitted * provided that this notice is preserved and that due credit is given * to the University of Michigan at Ann Arbor. The name of the University * may not be used to endorse or promote products derived from this * software without specific prior written permission. This software * is provided ``as is'' without express or implied warranty. */ /* This work was originally developed by the University of Michigan * and distributed as part of U-MICH LDAP. */ #include __RCSID("$NetBSD: detach.c,v 1.5.6.1 2019/08/10 06:17:16 martin Exp $"); #include "portable.h" #include #include #include #include #include #include #include #ifdef HAVE_SYS_FILE_H #include #endif #ifdef HAVE_SYS_IOCTL_H #include #endif #include "lutil.h" int lutil_detach( int debug, int do_close ) { int i, sd, nbits, pid; #ifdef HAVE_SYSCONF nbits = sysconf( _SC_OPEN_MAX ); #elif defined(HAVE_GETDTABLESIZE) nbits = getdtablesize(); #else nbits = FD_SETSIZE; #endif #ifdef FD_SETSIZE if ( nbits > FD_SETSIZE ) { nbits = FD_SETSIZE; } #endif /* FD_SETSIZE */ if ( debug == 0 ) { for ( i = 0; i < 5; i++ ) { #ifdef HAVE_THR pid = fork1(); #else pid = fork(); #endif switch ( pid ) { case -1: sleep( 5 ); continue; case 0: break; default: return pid; } break; } if ( (sd = open( "/dev/null", O_RDWR )) == -1 && (sd = open( "/dev/null", O_RDONLY )) == -1 && /* Panic -- open *something* */ (sd = open( "/", O_RDONLY )) == -1 ) { perror("/dev/null"); } else { /* redirect stdin, stdout, stderr to /dev/null */ dup2( sd, STDIN_FILENO ); dup2( sd, STDOUT_FILENO ); dup2( sd, STDERR_FILENO ); switch( sd ) { default: close( sd ); case STDIN_FILENO: case STDOUT_FILENO: case STDERR_FILENO: break; } } if ( do_close ) { /* close everything else */ for ( i = 0; i < nbits; i++ ) { if( i != STDIN_FILENO && i != STDOUT_FILENO && i != STDERR_FILENO ) { close( i ); } } } #ifdef CHDIR_TO_ROOT (void) chdir( "/" ); #endif #ifdef HAVE_SETSID (void) setsid(); #elif defined(TIOCNOTTY) if ( (sd = open( "/dev/tty", O_RDWR )) != -1 ) { (void) ioctl( sd, TIOCNOTTY, NULL ); (void) close( sd ); } #endif } #ifdef SIGPIPE (void) SIGNAL( SIGPIPE, SIG_IGN ); #endif return 0; }