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Diffstat (limited to 'libraries/liblutil/detach.c')
-rw-r--r-- | libraries/liblutil/detach.c | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/libraries/liblutil/detach.c b/libraries/liblutil/detach.c new file mode 100644 index 0000000..b2ce7c0 --- /dev/null +++ b/libraries/liblutil/detach.c @@ -0,0 +1,144 @@ +/* detach.c -- routines to daemonize a process */ +/* $OpenLDAP$ */ +/* This work is part of OpenLDAP Software <http://www.openldap.org/>. + * + * Copyright 1998-2021 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 + * <http://www.OpenLDAP.org/license.html>. + */ +/* + * 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 "portable.h" + +#include <stdio.h> + +#include <ac/stdlib.h> +#include <ac/signal.h> +#include <ac/socket.h> +#include <ac/unistd.h> + +#include <sys/stat.h> +#include <fcntl.h> + +#ifdef HAVE_SYS_FILE_H +#include <sys/file.h> +#endif +#ifdef HAVE_SYS_IOCTL_H +#include <sys/ioctl.h> +#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; +} |