1 /* fork.c - fork and exec a process, connecting stdin/out w/pipes */
2 /* $OpenLDAP$ */
3 /* This work is part of OpenLDAP Software <http://www.openldap.org/>.
4 *
5 * Copyright 1998-2021 The OpenLDAP Foundation.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted only as authorized by the OpenLDAP
10 * Public License.
11 *
12 * A copy of this license is available in the file LICENSE in the
13 * top-level directory of the distribution or, alternatively, at
14 * <http://www.OpenLDAP.org/license.html>.
15 */
16 /* Portions Copyright (c) 1995 Regents of the University of Michigan.
17 * All rights reserved.
18 *
19 * Redistribution and use in source and binary forms are permitted
20 * provided that this notice is preserved and that due credit is given
21 * to the University of Michigan at Ann Arbor. The name of the University
22 * may not be used to endorse or promote products derived from this
23 * software without specific prior written permission. This software
24 * is provided ``as is'' without express or implied warranty.
25 */
26 /* ACKNOWLEDGEMENTS:
27 * This work was originally developed by the University of Michigan
28 * (as part of U-MICH LDAP).
29 */
30
31 #include "portable.h"
32
33 #include <stdio.h>
34
35 #include <ac/errno.h>
36 #include <ac/string.h>
37 #include <ac/socket.h>
38 #include <ac/unistd.h>
39
40 #include "slap.h"
41 #include "shell.h"
42
43 pid_t
forkandexec(char ** args,FILE ** rfp,FILE ** wfp)44 forkandexec(
45 char **args,
46 FILE **rfp,
47 FILE **wfp
48 )
49 {
50 int p2c[2] = { -1, -1 }, c2p[2];
51 pid_t pid;
52
53 if ( pipe( p2c ) != 0 || pipe( c2p ) != 0 ) {
54 Debug( LDAP_DEBUG_ANY, "pipe failed\n", 0, 0, 0 );
55 close( p2c[0] );
56 close( p2c[1] );
57 return( -1 );
58 }
59
60 /*
61 * what we're trying to set up looks like this:
62 * parent *wfp -> p2c[1] | p2c[0] -> stdin child
63 * parent *rfp <- c2p[0] | c2p[1] <- stdout child
64 */
65
66 fflush( NULL );
67 # ifdef HAVE_THR
68 pid = fork1();
69 # else
70 pid = fork();
71 # endif
72 if ( pid == 0 ) { /* child */
73 /*
74 * child could deadlock here due to resources locked
75 * by our parent
76 *
77 * If so, configure --without-threads.
78 */
79 if ( dup2( p2c[0], 0 ) == -1 || dup2( c2p[1], 1 ) == -1 ) {
80 Debug( LDAP_DEBUG_ANY, "dup2 failed\n", 0, 0, 0 );
81 exit( EXIT_FAILURE );
82 }
83 }
84 close( p2c[0] );
85 close( c2p[1] );
86 if ( pid <= 0 ) {
87 close( p2c[1] );
88 close( c2p[0] );
89 }
90 switch ( pid ) {
91 case 0:
92 execv( args[0], args );
93
94 Debug( LDAP_DEBUG_ANY, "execv failed\n", 0, 0, 0 );
95 exit( EXIT_FAILURE );
96
97 case -1: /* trouble */
98 Debug( LDAP_DEBUG_ANY, "fork failed\n", 0, 0, 0 );
99 return( -1 );
100 }
101
102 /* parent */
103 if ( (*rfp = fdopen( c2p[0], "r" )) == NULL || (*wfp = fdopen( p2c[1],
104 "w" )) == NULL ) {
105 Debug( LDAP_DEBUG_ANY, "fdopen failed\n", 0, 0, 0 );
106 if ( *rfp ) {
107 fclose( *rfp );
108 *rfp = NULL;
109 } else {
110 close( c2p[0] );
111 }
112 close( p2c[1] );
113
114 return( -1 );
115 }
116
117 return( pid );
118 }
119