1/*-
  2 * SPDX-License-Identifier: BSD-2-Clause
  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
 29#ifndef _SYS_TTYHOOK_H_
 30#define	_SYS_TTYHOOK_H_
 31
 32#ifndef _SYS_TTY_H_
 33#error "can only be included through <sys/tty.h>"
 34#endif /* !_SYS_TTY_H_ */
 35
 36struct tty;
 37
 38/*
 39 * Hooks interface, which allows to capture and inject traffic into the
 40 * input and output paths of a TTY.
 41 */
 42
 43typedef int th_rint_t(struct tty *tp, char c, int flags);
 44typedef size_t th_rint_bypass_t(struct tty *tp, const void *buf, size_t len);
 45typedef void th_rint_done_t(struct tty *tp);
 46typedef size_t th_rint_poll_t(struct tty *tp);
 47
 48typedef size_t th_getc_inject_t(struct tty *tp, void *buf, size_t len);
 49typedef void th_getc_capture_t(struct tty *tp, const void *buf, size_t len);
 50typedef size_t th_getc_poll_t(struct tty *tp);
 51
 52typedef void th_close_t(struct tty *tp);
 53
 54struct ttyhook {
 55	/* Character input. */
 56	th_rint_t		*th_rint;
 57	th_rint_bypass_t	*th_rint_bypass;
 58	th_rint_done_t		*th_rint_done;
 59	th_rint_poll_t		*th_rint_poll;
 60
 61	/* Character output. */
 62	th_getc_inject_t	*th_getc_inject;
 63	th_getc_capture_t	*th_getc_capture;
 64	th_getc_poll_t		*th_getc_poll;
 65
 66	th_close_t		*th_close;
 67};
 68
 69int	ttyhook_register(struct tty **, struct proc *, int,
 70    struct ttyhook *, void *);
 71void	ttyhook_unregister(struct tty *);
 72#define	ttyhook_softc(tp)		((tp)->t_hooksoftc)
 73#define	ttyhook_hashook(tp,hook)	((tp)->t_hook != NULL && \
 74					(tp)->t_hook->th_ ## hook != NULL)
 75
 76static __inline int
 77ttyhook_rint(struct tty *tp, char c, int flags)
 78{
 79	tty_assert_locked(tp);
 80	MPASS(!tty_gone(tp));
 81
 82	return tp->t_hook->th_rint(tp, c, flags);
 83}
 84
 85static __inline size_t
 86ttyhook_rint_bypass(struct tty *tp, const void *buf, size_t len)
 87{
 88	tty_assert_locked(tp);
 89	MPASS(!tty_gone(tp));
 90
 91	return tp->t_hook->th_rint_bypass(tp, buf, len);
 92}
 93
 94static __inline void
 95ttyhook_rint_done(struct tty *tp)
 96{
 97	tty_assert_locked(tp);
 98	MPASS(!tty_gone(tp));
 99
100	tp->t_hook->th_rint_done(tp);
101}
102
103static __inline size_t
104ttyhook_rint_poll(struct tty *tp)
105{
106	tty_assert_locked(tp);
107	MPASS(!tty_gone(tp));
108
109	return tp->t_hook->th_rint_poll(tp);
110}
111
112static __inline size_t
113ttyhook_getc_inject(struct tty *tp, void *buf, size_t len)
114{
115	tty_assert_locked(tp);
116	MPASS(!tty_gone(tp));
117
118	return tp->t_hook->th_getc_inject(tp, buf, len);
119}
120
121static __inline void
122ttyhook_getc_capture(struct tty *tp, const void *buf, size_t len)
123{
124	tty_assert_locked(tp);
125	MPASS(!tty_gone(tp));
126
127	tp->t_hook->th_getc_capture(tp, buf, len);
128}
129
130static __inline size_t
131ttyhook_getc_poll(struct tty *tp)
132{
133	tty_assert_locked(tp);
134	MPASS(!tty_gone(tp));
135
136	return tp->t_hook->th_getc_poll(tp);
137}
138
139static __inline void
140ttyhook_close(struct tty *tp)
141{
142	tty_assert_locked(tp);
143
144	tp->t_hook->th_close(tp);
145}
146
147#endif /* !_SYS_TTYHOOK_H_ */