1 /* $NetBSD: detach.c,v 1.8 2021/08/14 16:14:58 christos Exp $ */
2
3 /* detach.c -- routines to daemonize a process */
4 /* $OpenLDAP$ */
5 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
6 *
7 * Copyright 1998-2021 The OpenLDAP Foundation.
8 * All rights reserved.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted only as authorized by the OpenLDAP
12 * Public License.
13 *
14 * A copy of this license is available in the file LICENSE in the
15 * top-level directory of the distribution or, alternatively, at
16 * <http://www.OpenLDAP.org/license.html>.
17 */
18 /*
19 * Copyright (c) 1990, 1994 Regents of the University of Michigan.
20 * All rights reserved.
21 *
22 * Redistribution and use in source and binary forms are permitted
23 * provided that this notice is preserved and that due credit is given
24 * to the University of Michigan at Ann Arbor. The name of the University
25 * may not be used to endorse or promote products derived from this
26 * software without specific prior written permission. This software
27 * is provided ``as is'' without express or implied warranty.
28 */
29 /* This work was originally developed by the University of Michigan
30 * and distributed as part of U-MICH LDAP.
31 */
32
33 #include <sys/cdefs.h>
34 __RCSID("$NetBSD: detach.c,v 1.8 2021/08/14 16:14:58 christos Exp $");
35
36 #include "portable.h"
37
38 #include <stdio.h>
39
40 #include <ac/stdlib.h>
41 #include <ac/signal.h>
42 #include <ac/socket.h>
43 #include <ac/unistd.h>
44
45 #include <sys/stat.h>
46 #include <fcntl.h>
47
48 #ifdef HAVE_SYS_FILE_H
49 #include <sys/file.h>
50 #endif
51 #ifdef HAVE_SYS_IOCTL_H
52 #include <sys/ioctl.h>
53 #endif
54
55 #include "lutil.h"
56
57 int
lutil_detach(int debug,int do_close)58 lutil_detach( int debug, int do_close )
59 {
60 int i, sd, nbits, pid;
61
62 #ifdef HAVE_SYSCONF
63 nbits = sysconf( _SC_OPEN_MAX );
64 #elif defined(HAVE_GETDTABLESIZE)
65 nbits = getdtablesize();
66 #else
67 nbits = FD_SETSIZE;
68 #endif
69
70 #ifdef FD_SETSIZE
71 if ( nbits > FD_SETSIZE ) {
72 nbits = FD_SETSIZE;
73 }
74 #endif /* FD_SETSIZE */
75
76 if ( debug == 0 ) {
77 for ( i = 0; i < 5; i++ ) {
78 #ifdef HAVE_THR
79 pid = fork1();
80 #else
81 pid = fork();
82 #endif
83 switch ( pid )
84 {
85 case -1:
86 sleep( 5 );
87 continue;
88
89 case 0:
90 break;
91
92 default:
93 return pid;
94 }
95 break;
96 }
97
98 if ( (sd = open( "/dev/null", O_RDWR )) == -1 &&
99 (sd = open( "/dev/null", O_RDONLY )) == -1 &&
100 /* Panic -- open *something* */
101 (sd = open( "/", O_RDONLY )) == -1 ) {
102 perror("/dev/null");
103 } else {
104 /* redirect stdin, stdout, stderr to /dev/null */
105 dup2( sd, STDIN_FILENO );
106 dup2( sd, STDOUT_FILENO );
107 dup2( sd, STDERR_FILENO );
108
109 switch( sd ) {
110 default:
111 close( sd );
112 case STDIN_FILENO:
113 case STDOUT_FILENO:
114 case STDERR_FILENO:
115 break;
116 }
117 }
118
119 if ( do_close ) {
120 /* close everything else */
121 for ( i = 0; i < nbits; i++ ) {
122 if( i != STDIN_FILENO &&
123 i != STDOUT_FILENO &&
124 i != STDERR_FILENO )
125 {
126 close( i );
127 }
128 }
129 }
130
131 #ifdef CHDIR_TO_ROOT
132 (void) chdir( "/" );
133 #endif
134
135 #ifdef HAVE_SETSID
136 (void) setsid();
137 #elif defined(TIOCNOTTY)
138 if ( (sd = open( "/dev/tty", O_RDWR )) != -1 ) {
139 (void) ioctl( sd, TIOCNOTTY, NULL );
140 (void) close( sd );
141 }
142 #endif
143 }
144
145 #ifdef SIGPIPE
146 (void) SIGNAL( SIGPIPE, SIG_IGN );
147 #endif
148 return 0;
149 }
150