/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */

/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*      Copyright (c) 1988 AT&T */
/*        All Rights Reserved   */

/*
 * Similar to popen(3C) but with pipe to cmd's stdin and from stdout.
 */

#include <sys/types.h>
#include <libgen.h>
#include <stdio.h>
#include <signal.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/wait.h>
#include <errno.h>
#include "lib_gen.h"

/* functions in libc */
extern int _insert(pid_t pid, int fd);
extern pid_t _delete(int fd);

int
p2open(const char *cmd, FILE *fp[2])
{
        int     fds[2];

        if (__p2open(cmd, fds) == -1)
                return (-1);

        fp[0] = fdopen(fds[0], "w");
        fp[1] = fdopen(fds[1], "r");
        return (0);
}

int
p2close(FILE *fp[2])
{
        return (__p2close(NULL, fp, 0));
}

int
__p2open(const char *cmd, int fds[2])
{
        int     tocmd[2];
        int     fromcmd[2];
        pid_t   pid;

        if (pipe(tocmd) < 0 || pipe(fromcmd) < 0)
                return (-1);
#ifndef _LP64
        if (tocmd[1] >= 256 || fromcmd[0] >= 256) {
                (void) close(tocmd[0]);
                (void) close(tocmd[1]);
                (void) close(fromcmd[0]);
                (void) close(fromcmd[1]);
                return (-1);
        }
#endif  /*      _LP64   */
        if ((pid = fork()) == 0) {
                (void) close(tocmd[1]);
                (void) close(0);
                (void) fcntl(tocmd[0], F_DUPFD, 0);
                (void) close(tocmd[0]);
                (void) close(fromcmd[0]);
                (void) close(1);
                (void) fcntl(fromcmd[1], F_DUPFD, 1);
                (void) close(fromcmd[1]);
                (void) execl("/bin/sh", "sh", "-c", cmd, 0);
                _exit(1);
        }
        if (pid == (pid_t)-1)
                return (-1);
        (void) _insert(pid, tocmd[1]);
        (void) _insert(pid, fromcmd[0]);
        (void) close(tocmd[0]);
        (void) close(fromcmd[1]);
        fds[0] = tocmd[1];
        fds[1] = fromcmd[0];
        return (0);
}

int
__p2close(int *fdp, FILE **fpp, int kill_sig)
{
        int             fds[2];
        int             status;
        void            (*hstat)(int), (*istat)(int), (*qstat)(int);
        pid_t pid, r;

        if (fdp != NULL) {
                fds[0] = fdp[0];
                fds[1] = fdp[1];
        } else if (fpp != NULL) {
                fds[0] = fileno(fpp[0]);
                fds[1] = fileno(fpp[1]);
        } else {
                return (-1);
        }

        pid = _delete(fds[0]);
        if (pid != _delete(fds[1]))
                return (-1);

        if (pid == (pid_t)-1)
                return (-1);

        if (kill_sig != 0) {
                (void) kill(pid, kill_sig);
        }

        if (fdp != NULL) {
                (void) close(fds[0]);
                (void) close(fds[1]);
        } else {
                (void) fclose(fpp[0]);
                (void) fclose(fpp[1]);
        }

        istat = signal(SIGINT, SIG_IGN);
        qstat = signal(SIGQUIT, SIG_IGN);
        hstat = signal(SIGHUP, SIG_IGN);
        while ((r = waitpid(pid, &status, 0)) == (pid_t)-1 && errno == EINTR)
                ;
        if (r == (pid_t)-1)
                status = -1;
        (void) signal(SIGINT, istat);
        (void) signal(SIGQUIT, qstat);
        (void) signal(SIGHUP, hstat);
        return (status);
}