openldap/servers/slapd/back-shell/fork.c
2000-05-15 16:35:48 +00:00

87 lines
1.7 KiB
C

/* fork.c - fork and exec a process, connecting stdin/out w/pipes */
/* $OpenLDAP$ */
/*
* Copyright 1998-2000 The OpenLDAP Foundation, All Rights Reserved.
* COPYING RESTRICTIONS APPLY, see COPYRIGHT file
*/
#include "portable.h"
#include <stdio.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], c2p[2];
pid_t pid;
if ( pipe( p2c ) != 0 || pipe( c2p ) != 0 ) {
Debug( LDAP_DEBUG_ANY, "pipe failed\n", 0, 0, 0 );
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
*/
#ifdef HAVE_THR
switch ( (pid = fork1()) )
#else
switch ( (pid = fork()) )
#endif
{
case 0: /* child */
/*
* child could deadlock here due to resources locked
* by our parent
*
* If so, configure --without-threads or implement forking
* via a surrogate parent.
*/
close( p2c[1] );
close( c2p[0] );
if ( dup2( p2c[0], 0 ) == -1 || dup2( c2p[1], 1 ) == -1 ) {
Debug( LDAP_DEBUG_ANY, "dup2 failed\n", 0, 0, 0 );
exit( EXIT_FAILURE );
}
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 );
default: /* parent */
close( p2c[0] );
close( c2p[1] );
break;
}
if ( (*rfp = fdopen( c2p[0], "r" )) == NULL || (*wfp = fdopen( p2c[1],
"w" )) == NULL ) {
Debug( LDAP_DEBUG_ANY, "fdopen failed\n", 0, 0, 0 );
close( c2p[0] );
close( p2c[1] );
return( -1 );
}
return( pid );
}