/*      $OpenBSD: tcflow.c,v 1.6 2017/09/10 18:20:00 guenther Exp $ */
/*-
 * Copyright (c) 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/ioctl.h>
#include <termios.h>
#include <unistd.h>
#include <errno.h>

int
tcflow(int fd, int action)
{
        struct termios term;
        u_char c;

        switch (action) {
        case TCOOFF:
                return (ioctl(fd, TIOCSTOP, 0));
        case TCOON:
                return (ioctl(fd, TIOCSTART, 0));
        case TCION:
        case TCIOFF:
                if (tcgetattr(fd, &term) == -1)
                        return (-1);
                c = term.c_cc[action == TCIOFF ? VSTOP : VSTART];
                if (c != _POSIX_VDISABLE &&
                    HIDDEN(write)(fd, &c, sizeof(c)) == -1)
                        return (-1);
                return (0);
        default:
                errno = EINVAL;
                return (-1);
        }
        /* NOTREACHED */
}