1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $FreeBSD$
29 */
30
31#ifndef _SYS_TTYHOOK_H_
32#define	_SYS_TTYHOOK_H_
33
34#ifndef _SYS_TTY_H_
35#error "can only be included through <sys/tty.h>"
36#endif /* !_SYS_TTY_H_ */
37
38struct tty;
39
40/*
41 * Hooks interface, which allows to capture and inject traffic into the
42 * input and output paths of a TTY.
43 */
44
45typedef int th_rint_t(struct tty *tp, char c, int flags);
46typedef size_t th_rint_bypass_t(struct tty *tp, const void *buf, size_t len);
47typedef void th_rint_done_t(struct tty *tp);
48typedef size_t th_rint_poll_t(struct tty *tp);
49
50typedef size_t th_getc_inject_t(struct tty *tp, void *buf, size_t len);
51typedef void th_getc_capture_t(struct tty *tp, const void *buf, size_t len);
52typedef size_t th_getc_poll_t(struct tty *tp);
53
54typedef void th_close_t(struct tty *tp);
55
56struct ttyhook {
57	/* Character input. */
58	th_rint_t		*th_rint;
59	th_rint_bypass_t	*th_rint_bypass;
60	th_rint_done_t		*th_rint_done;
61	th_rint_poll_t		*th_rint_poll;
62
63	/* Character output. */
64	th_getc_inject_t	*th_getc_inject;
65	th_getc_capture_t	*th_getc_capture;
66	th_getc_poll_t		*th_getc_poll;
67
68	th_close_t		*th_close;
69};
70
71int	ttyhook_register(struct tty **, struct proc *, int,
72    struct ttyhook *, void *);
73void	ttyhook_unregister(struct tty *);
74#define	ttyhook_softc(tp)		((tp)->t_hooksoftc)
75#define	ttyhook_hashook(tp,hook)	((tp)->t_hook != NULL && \
76					(tp)->t_hook->th_ ## hook != NULL)
77
78static __inline int
79ttyhook_rint(struct tty *tp, char c, int flags)
80{
81	tty_assert_locked(tp);
82	MPASS(!tty_gone(tp));
83
84	return tp->t_hook->th_rint(tp, c, flags);
85}
86
87static __inline size_t
88ttyhook_rint_bypass(struct tty *tp, const void *buf, size_t len)
89{
90	tty_assert_locked(tp);
91	MPASS(!tty_gone(tp));
92
93	return tp->t_hook->th_rint_bypass(tp, buf, len);
94}
95
96static __inline void
97ttyhook_rint_done(struct tty *tp)
98{
99	tty_assert_locked(tp);
100	MPASS(!tty_gone(tp));
101
102	tp->t_hook->th_rint_done(tp);
103}
104
105static __inline size_t
106ttyhook_rint_poll(struct tty *tp)
107{
108	tty_assert_locked(tp);
109	MPASS(!tty_gone(tp));
110
111	return tp->t_hook->th_rint_poll(tp);
112}
113
114static __inline size_t
115ttyhook_getc_inject(struct tty *tp, void *buf, size_t len)
116{
117	tty_assert_locked(tp);
118	MPASS(!tty_gone(tp));
119
120	return tp->t_hook->th_getc_inject(tp, buf, len);
121}
122
123static __inline void
124ttyhook_getc_capture(struct tty *tp, const void *buf, size_t len)
125{
126	tty_assert_locked(tp);
127	MPASS(!tty_gone(tp));
128
129	tp->t_hook->th_getc_capture(tp, buf, len);
130}
131
132static __inline size_t
133ttyhook_getc_poll(struct tty *tp)
134{
135	tty_assert_locked(tp);
136	MPASS(!tty_gone(tp));
137
138	return tp->t_hook->th_getc_poll(tp);
139}
140
141static __inline void
142ttyhook_close(struct tty *tp)
143{
144	tty_assert_locked(tp);
145
146	tp->t_hook->th_close(tp);
147}
148
149#endif /* !_SYS_TTYHOOK_H_ */
150