openldap/servers/slapd/back-shell/fork.c
2008-01-08 00:19:56 +00:00

119 lines
2.8 KiB
C

/* fork.c - fork and exec a process, connecting stdin/out w/pipes */
/* $OpenLDAP$ */
/* This work is part of OpenLDAP Software <http://www.openldap.org/>.
*
* Copyright 1998-2008 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>.
*/
/* Portions Copyright (c) 1995 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.
*/
/* ACKNOWLEDGEMENTS:
* This work was originally developed by the University of Michigan
* (as part of U-MICH LDAP).
*/
#include "portable.h"
#include <stdio.h>
#include <ac/errno.h>
#include <ac/string.h>
#include <ac/socket.h>
#include <ac/unistd.h>
#include "slap.h"
#include "shell.h"
pid_t
forkandexec(
char **args,
FILE **rfp,
FILE **wfp
)
{
int p2c[2] = { -1, -1 }, c2p[2];
pid_t pid;
if ( pipe( p2c ) != 0 || pipe( c2p ) != 0 ) {
Debug( LDAP_DEBUG_ANY, "pipe failed\n", 0, 0, 0 );
close( p2c[0] );
close( p2c[1] );
return( -1 );
}
/*
* what we're trying to set up looks like this:
* parent *wfp -> p2c[1] | p2c[0] -> stdin child
* parent *rfp <- c2p[0] | c2p[1] <- stdout child
*/
fflush( NULL );
# ifdef HAVE_THR
pid = fork1();
# else
pid = fork();
# endif
if ( pid == 0 ) { /* child */
/*
* child could deadlock here due to resources locked
* by our parent
*
* If so, configure --without-threads.
*/
if ( dup2( p2c[0], 0 ) == -1 || dup2( c2p[1], 1 ) == -1 ) {
Debug( LDAP_DEBUG_ANY, "dup2 failed\n", 0, 0, 0 );
exit( EXIT_FAILURE );
}
}
close( p2c[0] );
close( c2p[1] );
if ( pid <= 0 ) {
close( p2c[1] );
close( c2p[0] );
}
switch ( pid ) {
case 0:
execv( args[0], args );
Debug( LDAP_DEBUG_ANY, "execv failed\n", 0, 0, 0 );
exit( EXIT_FAILURE );
case -1: /* trouble */
Debug( LDAP_DEBUG_ANY, "fork failed\n", 0, 0, 0 );
return( -1 );
}
/* parent */
if ( (*rfp = fdopen( c2p[0], "r" )) == NULL || (*wfp = fdopen( p2c[1],
"w" )) == NULL ) {
Debug( LDAP_DEBUG_ANY, "fdopen failed\n", 0, 0, 0 );
if ( *rfp ) {
fclose( *rfp );
*rfp = NULL;
} else {
close( c2p[0] );
}
close( p2c[1] );
return( -1 );
}
return( pid );
}