1 /* $OpenBSD: tcflow.c,v 1.6 2017/09/10 18:20:00 guenther Exp $ */
2 /*-
3 * Copyright (c) 1989, 1993
4 * The Regents of the University of California. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the University nor the names of its contributors
15 * may be used to endorse or promote products derived from this software
16 * without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31 #include <sys/ioctl.h>
32 #include <termios.h>
33 #include <unistd.h>
34 #include <errno.h>
35
36 int
tcflow(int fd,int action)37 tcflow(int fd, int action)
38 {
39 struct termios term;
40 u_char c;
41
42 switch (action) {
43 case TCOOFF:
44 return (ioctl(fd, TIOCSTOP, 0));
45 case TCOON:
46 return (ioctl(fd, TIOCSTART, 0));
47 case TCION:
48 case TCIOFF:
49 if (tcgetattr(fd, &term) == -1)
50 return (-1);
51 c = term.c_cc[action == TCIOFF ? VSTOP : VSTART];
52 if (c != _POSIX_VDISABLE &&
53 HIDDEN(write)(fd, &c, sizeof(c)) == -1)
54 return (-1);
55 return (0);
56 default:
57 errno = EINVAL;
58 return (-1);
59 }
60 /* NOTREACHED */
61 }
62