xref: /freebsd/sys/kern/tty.c (revision 7850fa71f55a16f414bb21163d80a03a5ab34522)
1 /*-
2  * Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Portions of this software were developed under sponsorship from Snow
6  * B.V., the Netherlands.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include "opt_compat.h"
34 
35 #include <sys/param.h>
36 #include <sys/conf.h>
37 #include <sys/cons.h>
38 #include <sys/fcntl.h>
39 #include <sys/file.h>
40 #include <sys/filedesc.h>
41 #include <sys/filio.h>
42 #ifdef COMPAT_43TTY
43 #include <sys/ioctl_compat.h>
44 #endif /* COMPAT_43TTY */
45 #include <sys/kernel.h>
46 #include <sys/limits.h>
47 #include <sys/malloc.h>
48 #include <sys/mount.h>
49 #include <sys/poll.h>
50 #include <sys/priv.h>
51 #include <sys/proc.h>
52 #include <sys/serial.h>
53 #include <sys/signal.h>
54 #include <sys/stat.h>
55 #include <sys/sx.h>
56 #include <sys/sysctl.h>
57 #include <sys/systm.h>
58 #include <sys/tty.h>
59 #include <sys/ttycom.h>
60 #define TTYDEFCHARS
61 #include <sys/ttydefaults.h>
62 #undef TTYDEFCHARS
63 #include <sys/ucred.h>
64 #include <sys/vnode.h>
65 
66 #include <machine/stdarg.h>
67 
68 static MALLOC_DEFINE(M_TTY, "tty", "tty device");
69 
70 static void tty_rel_free(struct tty *tp);
71 
72 static TAILQ_HEAD(, tty) tty_list = TAILQ_HEAD_INITIALIZER(tty_list);
73 static struct sx tty_list_sx;
74 SX_SYSINIT(tty_list, &tty_list_sx, "tty list");
75 static unsigned int tty_list_count = 0;
76 
77 /* Character device of /dev/console. */
78 static struct cdev	*dev_console;
79 static const char	*dev_console_filename;
80 
81 /*
82  * Flags that are supported and stored by this implementation.
83  */
84 #define TTYSUP_IFLAG	(IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK|ISTRIP|\
85 			INLCR|IGNCR|ICRNL|IXON|IXOFF|IXANY|IMAXBEL)
86 #define TTYSUP_OFLAG	(OPOST|ONLCR|TAB3|ONOEOT|OCRNL|ONOCR|ONLRET)
87 #define TTYSUP_LFLAG	(ECHOKE|ECHOE|ECHOK|ECHO|ECHONL|ECHOPRT|\
88 			ECHOCTL|ISIG|ICANON|ALTWERASE|IEXTEN|TOSTOP|\
89 			FLUSHO|NOKERNINFO|NOFLSH)
90 #define TTYSUP_CFLAG	(CIGNORE|CSIZE|CSTOPB|CREAD|PARENB|PARODD|\
91 			HUPCL|CLOCAL|CCTS_OFLOW|CRTS_IFLOW|CDTR_IFLOW|\
92 			CDSR_OFLOW|CCAR_OFLOW)
93 
94 #define	TTY_CALLOUT(tp,d) ((d) != (tp)->t_dev && (d) != dev_console)
95 
96 /*
97  * Set TTY buffer sizes.
98  */
99 
100 #define	TTYBUF_MAX	65536
101 
102 static void
103 tty_watermarks(struct tty *tp)
104 {
105 	size_t bs;
106 
107 	/* Provide an input buffer for 0.2 seconds of data. */
108 	bs = MIN(tp->t_termios.c_ispeed / 5, TTYBUF_MAX);
109 	ttyinq_setsize(&tp->t_inq, tp, bs);
110 
111 	/* Set low watermark at 10% (when 90% is available). */
112 	tp->t_inlow = (ttyinq_getsize(&tp->t_inq) * 9) / 10;
113 
114 	/* Provide an ouput buffer for 0.2 seconds of data. */
115 	bs = MIN(tp->t_termios.c_ospeed / 5, TTYBUF_MAX);
116 	ttyoutq_setsize(&tp->t_outq, tp, bs);
117 
118 	/* Set low watermark at 10% (when 90% is available). */
119 	tp->t_outlow = (ttyoutq_getsize(&tp->t_outq) * 9) / 10;
120 }
121 
122 static int
123 tty_drain(struct tty *tp)
124 {
125 	int error;
126 
127 	if (ttyhook_hashook(tp, getc_inject))
128 		/* buffer is inaccessible */
129 		return (0);
130 
131 	while (ttyoutq_bytesused(&tp->t_outq) > 0) {
132 		ttydevsw_outwakeup(tp);
133 		/* Could be handled synchronously. */
134 		if (ttyoutq_bytesused(&tp->t_outq) == 0)
135 			return (0);
136 
137 		/* Wait for data to be drained. */
138 		error = tty_wait(tp, &tp->t_outwait);
139 		if (error)
140 			return (error);
141 	}
142 
143 	return (0);
144 }
145 
146 /*
147  * Though ttydev_enter() and ttydev_leave() seem to be related, they
148  * don't have to be used together. ttydev_enter() is used by the cdev
149  * operations to prevent an actual operation from being processed when
150  * the TTY has been abandoned. ttydev_leave() is used by ttydev_open()
151  * and ttydev_close() to determine whether per-TTY data should be
152  * deallocated.
153  */
154 
155 static __inline int
156 ttydev_enter(struct tty *tp)
157 {
158 	tty_lock(tp);
159 
160 	if (tty_gone(tp) || !tty_opened(tp)) {
161 		/* Device is already gone. */
162 		tty_unlock(tp);
163 		return (ENXIO);
164 	}
165 
166 	return (0);
167 }
168 
169 static void
170 ttydev_leave(struct tty *tp)
171 {
172 	tty_lock_assert(tp, MA_OWNED);
173 
174 	if (tty_opened(tp) || tp->t_flags & TF_OPENCLOSE) {
175 		/* Device is still opened somewhere. */
176 		tty_unlock(tp);
177 		return;
178 	}
179 
180 	tp->t_flags |= TF_OPENCLOSE;
181 
182 	/* Stop asynchronous I/O. */
183 	funsetown(&tp->t_sigio);
184 
185 	/* Remove console TTY. */
186 	if (constty == tp)
187 		constty_clear();
188 
189 	/* Drain any output. */
190 	MPASS((tp->t_flags & TF_STOPPED) == 0);
191 	if (!tty_gone(tp))
192 		tty_drain(tp);
193 
194 	ttydisc_close(tp);
195 
196 	/* Destroy associated buffers already. */
197 	ttyinq_free(&tp->t_inq);
198 	tp->t_inlow = 0;
199 	ttyoutq_free(&tp->t_outq);
200 	tp->t_outlow = 0;
201 
202 	knlist_clear(&tp->t_inpoll.si_note, 1);
203 	knlist_clear(&tp->t_outpoll.si_note, 1);
204 
205 	if (!tty_gone(tp))
206 		ttydevsw_close(tp);
207 
208 	tp->t_flags &= ~TF_OPENCLOSE;
209 	cv_broadcast(&tp->t_dcdwait);
210 	tty_rel_free(tp);
211 }
212 
213 /*
214  * Operations that are exposed through the character device in /dev.
215  */
216 static int
217 ttydev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
218 {
219 	struct tty *tp = dev->si_drv1;
220 	int error = 0;
221 
222 	tty_lock(tp);
223 	if (tty_gone(tp)) {
224 		/* Device is already gone. */
225 		tty_unlock(tp);
226 		return (ENXIO);
227 	}
228 
229 	/*
230 	 * Block when other processes are currently opening or closing
231 	 * the TTY.
232 	 */
233 	while (tp->t_flags & TF_OPENCLOSE) {
234 		error = tty_wait(tp, &tp->t_dcdwait);
235 		if (error != 0) {
236 			tty_unlock(tp);
237 			return (error);
238 		}
239 	}
240 	tp->t_flags |= TF_OPENCLOSE;
241 
242 	/*
243 	 * Make sure the "tty" and "cua" device cannot be opened at the
244 	 * same time.
245 	 */
246 	if (TTY_CALLOUT(tp, dev)) {
247 		if (tp->t_flags & TF_OPENED_IN) {
248 			error = EBUSY;
249 			goto done;
250 		}
251 	} else {
252 		if (tp->t_flags & TF_OPENED_OUT) {
253 			error = EBUSY;
254 			goto done;
255 		}
256 	}
257 
258 	if (tp->t_flags & TF_EXCLUDE && priv_check(td, PRIV_TTY_EXCLUSIVE)) {
259 		error = EBUSY;
260 		goto done;
261 	}
262 
263 	if (!tty_opened(tp)) {
264 		/* Set proper termios flags. */
265 		if (TTY_CALLOUT(tp, dev)) {
266 			tp->t_termios = tp->t_termios_init_out;
267 		} else {
268 			tp->t_termios = tp->t_termios_init_in;
269 		}
270 		ttydevsw_param(tp, &tp->t_termios);
271 
272 		ttydevsw_modem(tp, SER_DTR|SER_RTS, 0);
273 
274 		error = ttydevsw_open(tp);
275 		if (error != 0)
276 			goto done;
277 
278 		ttydisc_open(tp);
279 		tty_watermarks(tp);
280 	}
281 
282 	/* Wait for Carrier Detect. */
283 	if (!TTY_CALLOUT(tp, dev) && (oflags & O_NONBLOCK) == 0 &&
284 	    (tp->t_termios.c_cflag & CLOCAL) == 0) {
285 		while ((ttydevsw_modem(tp, 0, 0) & SER_DCD) == 0) {
286 			error = tty_wait(tp, &tp->t_dcdwait);
287 			if (error != 0)
288 				goto done;
289 		}
290 	}
291 
292 	if (dev == dev_console)
293 		tp->t_flags |= TF_OPENED_CONS;
294 	else if (TTY_CALLOUT(tp, dev))
295 		tp->t_flags |= TF_OPENED_OUT;
296 	else
297 		tp->t_flags |= TF_OPENED_IN;
298 
299 done:	tp->t_flags &= ~TF_OPENCLOSE;
300 	cv_broadcast(&tp->t_dcdwait);
301 	ttydev_leave(tp);
302 
303 	return (error);
304 }
305 
306 static int
307 ttydev_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
308 {
309 	struct tty *tp = dev->si_drv1;
310 
311 	tty_lock(tp);
312 
313 	/*
314 	 * Don't actually close the device if it is being used as the
315 	 * console.
316 	 */
317 	MPASS((tp->t_flags & TF_OPENED) != TF_OPENED);
318 	if (dev == dev_console)
319 		tp->t_flags &= ~TF_OPENED_CONS;
320 	else
321 		tp->t_flags &= ~(TF_OPENED_IN|TF_OPENED_OUT);
322 
323 	if (tp->t_flags & TF_OPENED) {
324 		tty_unlock(tp);
325 		return (0);
326 	}
327 
328 	/*
329 	 * This can only be called once. The callin and the callout
330 	 * devices cannot be opened at the same time.
331 	 */
332 	tp->t_flags &= ~(TF_EXCLUDE|TF_STOPPED);
333 
334 	/* Properly wake up threads that are stuck - revoke(). */
335 	tp->t_revokecnt++;
336 	tty_wakeup(tp, FREAD|FWRITE);
337 	cv_broadcast(&tp->t_bgwait);
338 	cv_broadcast(&tp->t_dcdwait);
339 
340 	ttydev_leave(tp);
341 
342 	return (0);
343 }
344 
345 static __inline int
346 tty_is_ctty(struct tty *tp, struct proc *p)
347 {
348 	tty_lock_assert(tp, MA_OWNED);
349 
350 	return (p->p_session == tp->t_session && p->p_flag & P_CONTROLT);
351 }
352 
353 static int
354 tty_wait_background(struct tty *tp, struct thread *td, int sig)
355 {
356 	struct proc *p = td->td_proc;
357 	struct pgrp *pg;
358 	int error;
359 
360 	MPASS(sig == SIGTTIN || sig == SIGTTOU);
361 	tty_lock_assert(tp, MA_OWNED);
362 
363 	for (;;) {
364 		PROC_LOCK(p);
365 		/*
366 		 * The process should only sleep, when:
367 		 * - This terminal is the controling terminal
368 		 * - Its process group is not the foreground process
369 		 *   group
370 		 * - The parent process isn't waiting for the child to
371 		 *   exit
372 		 * - the signal to send to the process isn't masked
373 		 */
374 		if (!tty_is_ctty(tp, p) || p->p_pgrp == tp->t_pgrp) {
375 			/* Allow the action to happen. */
376 			PROC_UNLOCK(p);
377 			return (0);
378 		}
379 
380 		if (SIGISMEMBER(p->p_sigacts->ps_sigignore, sig) ||
381 		    SIGISMEMBER(td->td_sigmask, sig)) {
382 			/* Only allow them in write()/ioctl(). */
383 			PROC_UNLOCK(p);
384 			return (sig == SIGTTOU ? 0 : EIO);
385 		}
386 
387 		pg = p->p_pgrp;
388 		if (p->p_flag & P_PPWAIT || pg->pg_jobc == 0) {
389 			/* Don't allow the action to happen. */
390 			PROC_UNLOCK(p);
391 			return (EIO);
392 		}
393 		PROC_UNLOCK(p);
394 
395 		/*
396 		 * Send the signal and sleep until we're the new
397 		 * foreground process group.
398 		 */
399 		PGRP_LOCK(pg);
400 		pgsignal(pg, sig, 1);
401 		PGRP_UNLOCK(pg);
402 
403 		error = tty_wait(tp, &tp->t_bgwait);
404 		if (error)
405 			return (error);
406 	}
407 }
408 
409 static int
410 ttydev_read(struct cdev *dev, struct uio *uio, int ioflag)
411 {
412 	struct tty *tp = dev->si_drv1;
413 	int error;
414 
415 	error = ttydev_enter(tp);
416 	if (error)
417 		goto done;
418 
419 	error = tty_wait_background(tp, curthread, SIGTTIN);
420 	if (error) {
421 		tty_unlock(tp);
422 		goto done;
423 	}
424 
425 	error = ttydisc_read(tp, uio, ioflag);
426 	tty_unlock(tp);
427 
428 	/*
429 	 * The read() call should not throw an error when the device is
430 	 * being destroyed. Silently convert it to an EOF.
431 	 */
432 done:	if (error == ENXIO)
433 		error = 0;
434 	return (error);
435 }
436 
437 static int
438 ttydev_write(struct cdev *dev, struct uio *uio, int ioflag)
439 {
440 	struct tty *tp = dev->si_drv1;
441 	int error;
442 
443 	error = ttydev_enter(tp);
444 	if (error)
445 		return (error);
446 
447 	if (tp->t_termios.c_lflag & TOSTOP) {
448 		error = tty_wait_background(tp, curthread, SIGTTOU);
449 		if (error)
450 			goto done;
451 	}
452 
453 	if (ioflag & IO_NDELAY && tp->t_flags & TF_BUSY_OUT) {
454 		/* Allow non-blocking writes to bypass serialization. */
455 		error = ttydisc_write(tp, uio, ioflag);
456 	} else {
457 		/* Serialize write() calls. */
458 		while (tp->t_flags & TF_BUSY_OUT) {
459 			error = tty_wait(tp, &tp->t_outserwait);
460 			if (error)
461 				goto done;
462 		}
463 
464  		tp->t_flags |= TF_BUSY_OUT;
465 		error = ttydisc_write(tp, uio, ioflag);
466  		tp->t_flags &= ~TF_BUSY_OUT;
467 		cv_signal(&tp->t_outserwait);
468 	}
469 
470 done:	tty_unlock(tp);
471 	return (error);
472 }
473 
474 static int
475 ttydev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
476     struct thread *td)
477 {
478 	struct tty *tp = dev->si_drv1;
479 	int error;
480 
481 	error = ttydev_enter(tp);
482 	if (error)
483 		return (error);
484 
485 	switch (cmd) {
486 	case TIOCCBRK:
487 	case TIOCCONS:
488 	case TIOCDRAIN:
489 	case TIOCEXCL:
490 	case TIOCFLUSH:
491 	case TIOCNXCL:
492 	case TIOCSBRK:
493 	case TIOCSCTTY:
494 	case TIOCSETA:
495 	case TIOCSETAF:
496 	case TIOCSETAW:
497 	case TIOCSPGRP:
498 	case TIOCSTART:
499 	case TIOCSTAT:
500 	case TIOCSTOP:
501 	case TIOCSWINSZ:
502 #if 0
503 	case TIOCSDRAINWAIT:
504 	case TIOCSETD:
505 	case TIOCSTI:
506 #endif
507 #ifdef COMPAT_43TTY
508 	case  TIOCLBIC:
509 	case  TIOCLBIS:
510 	case  TIOCLSET:
511 	case  TIOCSETC:
512 	case OTIOCSETD:
513 	case  TIOCSETN:
514 	case  TIOCSETP:
515 	case  TIOCSLTC:
516 #endif /* COMPAT_43TTY */
517 		/*
518 		 * If the ioctl() causes the TTY to be modified, let it
519 		 * wait in the background.
520 		 */
521 		error = tty_wait_background(tp, curthread, SIGTTOU);
522 		if (error)
523 			goto done;
524 	}
525 
526 	error = tty_ioctl(tp, cmd, data, td);
527 done:	tty_unlock(tp);
528 
529 	return (error);
530 }
531 
532 static int
533 ttydev_poll(struct cdev *dev, int events, struct thread *td)
534 {
535 	struct tty *tp = dev->si_drv1;
536 	int error, revents = 0;
537 
538 	error = ttydev_enter(tp);
539 	if (error) {
540 		/* Don't return the error here, but the event mask. */
541 		return (events &
542 		    (POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM));
543 	}
544 
545 	if (events & (POLLIN|POLLRDNORM)) {
546 		/* See if we can read something. */
547 		if (ttydisc_read_poll(tp) > 0)
548 			revents |= events & (POLLIN|POLLRDNORM);
549 	}
550 	if (events & (POLLOUT|POLLWRNORM)) {
551 		/* See if we can write something. */
552 		if (ttydisc_write_poll(tp) > 0)
553 			revents |= events & (POLLOUT|POLLWRNORM);
554 	}
555 	if (tp->t_flags & TF_ZOMBIE)
556 		/* Hangup flag on zombie state. */
557 		revents |= events & POLLHUP;
558 
559 	if (revents == 0) {
560 		if (events & (POLLIN|POLLRDNORM))
561 			selrecord(td, &tp->t_inpoll);
562 		if (events & (POLLOUT|POLLWRNORM))
563 			selrecord(td, &tp->t_outpoll);
564 	}
565 
566 	tty_unlock(tp);
567 
568 	return (revents);
569 }
570 
571 static int
572 ttydev_mmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr, int nprot)
573 {
574 	struct tty *tp = dev->si_drv1;
575 	int error;
576 
577 	/* Handle mmap() through the driver. */
578 
579 	error = ttydev_enter(tp);
580 	if (error)
581 		return (-1);
582 	error = ttydevsw_mmap(tp, offset, paddr, nprot);
583 	tty_unlock(tp);
584 
585 	return (error);
586 }
587 
588 /*
589  * kqueue support.
590  */
591 
592 static void
593 tty_kqops_read_detach(struct knote *kn)
594 {
595 	struct tty *tp = kn->kn_hook;
596 
597 	knlist_remove(&tp->t_inpoll.si_note, kn, 0);
598 }
599 
600 static int
601 tty_kqops_read_event(struct knote *kn, long hint)
602 {
603 	struct tty *tp = kn->kn_hook;
604 
605 	tty_lock_assert(tp, MA_OWNED);
606 
607 	if (tty_gone(tp) || tp->t_flags & TF_ZOMBIE) {
608 		kn->kn_flags |= EV_EOF;
609 		return (1);
610 	} else {
611 		kn->kn_data = ttydisc_read_poll(tp);
612 		return (kn->kn_data > 0);
613 	}
614 }
615 
616 static void
617 tty_kqops_write_detach(struct knote *kn)
618 {
619 	struct tty *tp = kn->kn_hook;
620 
621 	knlist_remove(&tp->t_outpoll.si_note, kn, 0);
622 }
623 
624 static int
625 tty_kqops_write_event(struct knote *kn, long hint)
626 {
627 	struct tty *tp = kn->kn_hook;
628 
629 	tty_lock_assert(tp, MA_OWNED);
630 
631 	if (tty_gone(tp)) {
632 		kn->kn_flags |= EV_EOF;
633 		return (1);
634 	} else {
635 		kn->kn_data = ttydisc_write_poll(tp);
636 		return (kn->kn_data > 0);
637 	}
638 }
639 
640 static struct filterops tty_kqops_read =
641     { 1, NULL, tty_kqops_read_detach, tty_kqops_read_event };
642 static struct filterops tty_kqops_write =
643     { 1, NULL, tty_kqops_write_detach, tty_kqops_write_event };
644 
645 static int
646 ttydev_kqfilter(struct cdev *dev, struct knote *kn)
647 {
648 	struct tty *tp = dev->si_drv1;
649 	int error;
650 
651 	error = ttydev_enter(tp);
652 	if (error)
653 		return (error);
654 
655 	switch (kn->kn_filter) {
656 	case EVFILT_READ:
657 		kn->kn_hook = tp;
658 		kn->kn_fop = &tty_kqops_read;
659 		knlist_add(&tp->t_inpoll.si_note, kn, 1);
660 		break;
661 	case EVFILT_WRITE:
662 		kn->kn_hook = tp;
663 		kn->kn_fop = &tty_kqops_write;
664 		knlist_add(&tp->t_outpoll.si_note, kn, 1);
665 		break;
666 	default:
667 		error = EINVAL;
668 		break;
669 	}
670 
671 	tty_unlock(tp);
672 	return (error);
673 }
674 
675 static struct cdevsw ttydev_cdevsw = {
676 	.d_version	= D_VERSION,
677 	.d_open		= ttydev_open,
678 	.d_close	= ttydev_close,
679 	.d_read		= ttydev_read,
680 	.d_write	= ttydev_write,
681 	.d_ioctl	= ttydev_ioctl,
682 	.d_kqfilter	= ttydev_kqfilter,
683 	.d_poll		= ttydev_poll,
684 	.d_mmap		= ttydev_mmap,
685 	.d_name		= "ttydev",
686 	.d_flags	= D_TTY,
687 };
688 
689 /*
690  * Init/lock-state devices
691  */
692 
693 static int
694 ttyil_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
695 {
696 	struct tty *tp = dev->si_drv1;
697 	int error = 0;
698 
699 	tty_lock(tp);
700 	if (tty_gone(tp))
701 		error = ENODEV;
702 	tty_unlock(tp);
703 
704 	return (error);
705 }
706 
707 static int
708 ttyil_close(struct cdev *dev, int flag, int mode, struct thread *td)
709 {
710 	return (0);
711 }
712 
713 static int
714 ttyil_rdwr(struct cdev *dev, struct uio *uio, int ioflag)
715 {
716 	return (ENODEV);
717 }
718 
719 static int
720 ttyil_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
721     struct thread *td)
722 {
723 	struct tty *tp = dev->si_drv1;
724 	int error = 0;
725 
726 	tty_lock(tp);
727 	if (tty_gone(tp)) {
728 		error = ENODEV;
729 		goto done;
730 	}
731 
732 	switch (cmd) {
733 	case TIOCGETA:
734 		/* Obtain terminal flags through tcgetattr(). */
735 		*(struct termios*)data = *(struct termios*)dev->si_drv2;
736 		break;
737 	case TIOCSETA:
738 		/* Set terminal flags through tcsetattr(). */
739 		error = priv_check(td, PRIV_TTY_SETA);
740 		if (error)
741 			break;
742 		*(struct termios*)dev->si_drv2 = *(struct termios*)data;
743 		break;
744 	case TIOCGETD:
745 		*(int *)data = TTYDISC;
746 		break;
747 	case TIOCGWINSZ:
748 		bzero(data, sizeof(struct winsize));
749 		break;
750 	default:
751 		error = ENOTTY;
752 	}
753 
754 done:	tty_unlock(tp);
755 	return (error);
756 }
757 
758 static struct cdevsw ttyil_cdevsw = {
759 	.d_version	= D_VERSION,
760 	.d_open		= ttyil_open,
761 	.d_close	= ttyil_close,
762 	.d_read		= ttyil_rdwr,
763 	.d_write	= ttyil_rdwr,
764 	.d_ioctl	= ttyil_ioctl,
765 	.d_name		= "ttyil",
766 	.d_flags	= D_TTY,
767 };
768 
769 static void
770 tty_init_termios(struct tty *tp)
771 {
772 	struct termios *t = &tp->t_termios_init_in;
773 
774 	t->c_cflag = TTYDEF_CFLAG;
775 	t->c_iflag = TTYDEF_IFLAG;
776 	t->c_lflag = TTYDEF_LFLAG;
777 	t->c_oflag = TTYDEF_OFLAG;
778 	t->c_ispeed = TTYDEF_SPEED;
779 	t->c_ospeed = TTYDEF_SPEED;
780 	memcpy(&t->c_cc, ttydefchars, sizeof ttydefchars);
781 
782 	tp->t_termios_init_out = *t;
783 }
784 
785 void
786 tty_init_console(struct tty *tp, speed_t s)
787 {
788 	struct termios *ti = &tp->t_termios_init_in;
789 	struct termios *to = &tp->t_termios_init_out;
790 
791 	if (s != 0) {
792 		ti->c_ispeed = ti->c_ospeed = s;
793 		to->c_ispeed = to->c_ospeed = s;
794 	}
795 
796 	ti->c_cflag |= CLOCAL;
797 	to->c_cflag |= CLOCAL;
798 }
799 
800 /*
801  * Standard device routine implementations, mostly meant for
802  * pseudo-terminal device drivers. When a driver creates a new terminal
803  * device class, missing routines are patched.
804  */
805 
806 static int
807 ttydevsw_defopen(struct tty *tp)
808 {
809 
810 	return (0);
811 }
812 
813 static void
814 ttydevsw_defclose(struct tty *tp)
815 {
816 }
817 
818 static void
819 ttydevsw_defoutwakeup(struct tty *tp)
820 {
821 
822 	panic("Terminal device has output, while not implemented");
823 }
824 
825 static void
826 ttydevsw_definwakeup(struct tty *tp)
827 {
828 }
829 
830 static int
831 ttydevsw_defioctl(struct tty *tp, u_long cmd, caddr_t data, struct thread *td)
832 {
833 
834 	return (ENOIOCTL);
835 }
836 
837 static int
838 ttydevsw_defparam(struct tty *tp, struct termios *t)
839 {
840 
841 	/* Use a fake baud rate, we're not a real device. */
842 	t->c_ispeed = t->c_ospeed = TTYDEF_SPEED;
843 
844 	return (0);
845 }
846 
847 static int
848 ttydevsw_defmodem(struct tty *tp, int sigon, int sigoff)
849 {
850 
851 	/* Simulate a carrier to make the TTY layer happy. */
852 	return (SER_DCD);
853 }
854 
855 static int
856 ttydevsw_defmmap(struct tty *tp, vm_offset_t offset, vm_paddr_t *paddr,
857     int nprot)
858 {
859 
860 	return (-1);
861 }
862 
863 static void
864 ttydevsw_defpktnotify(struct tty *tp, char event)
865 {
866 }
867 
868 static void
869 ttydevsw_deffree(void *softc)
870 {
871 
872 	panic("Terminal device freed without a free-handler");
873 }
874 
875 /*
876  * TTY allocation and deallocation. TTY devices can be deallocated when
877  * the driver doesn't use it anymore, when the TTY isn't a session's
878  * controlling TTY and when the device node isn't opened through devfs.
879  */
880 
881 struct tty *
882 tty_alloc(struct ttydevsw *tsw, void *sc)
883 {
884 
885 	return (tty_alloc_mutex(tsw, sc, NULL));
886 }
887 
888 struct tty *
889 tty_alloc_mutex(struct ttydevsw *tsw, void *sc, struct mtx *mutex)
890 {
891 	struct tty *tp;
892 
893 	/* Make sure the driver defines all routines. */
894 #define PATCH_FUNC(x) do {				\
895 	if (tsw->tsw_ ## x == NULL)			\
896 		tsw->tsw_ ## x = ttydevsw_def ## x;	\
897 } while (0)
898 	PATCH_FUNC(open);
899 	PATCH_FUNC(close);
900 	PATCH_FUNC(outwakeup);
901 	PATCH_FUNC(inwakeup);
902 	PATCH_FUNC(ioctl);
903 	PATCH_FUNC(param);
904 	PATCH_FUNC(modem);
905 	PATCH_FUNC(mmap);
906 	PATCH_FUNC(pktnotify);
907 	PATCH_FUNC(free);
908 #undef PATCH_FUNC
909 
910 	tp = malloc(sizeof(struct tty), M_TTY, M_WAITOK|M_ZERO);
911 	tp->t_devsw = tsw;
912 	tp->t_devswsoftc = sc;
913 	tp->t_flags = tsw->tsw_flags;
914 
915 	tty_init_termios(tp);
916 
917 	cv_init(&tp->t_inwait, "ttyin");
918 	cv_init(&tp->t_outwait, "ttyout");
919 	cv_init(&tp->t_outserwait, "ttyosr");
920 	cv_init(&tp->t_bgwait, "ttybg");
921 	cv_init(&tp->t_dcdwait, "ttydcd");
922 
923 	/* Allow drivers to use a custom mutex to lock the TTY. */
924 	if (mutex != NULL) {
925 		tp->t_mtx = mutex;
926 	} else {
927 		tp->t_mtx = &tp->t_mtxobj;
928 		mtx_init(&tp->t_mtxobj, "ttymtx", NULL, MTX_DEF);
929 	}
930 
931 	knlist_init_mtx(&tp->t_inpoll.si_note, tp->t_mtx);
932 	knlist_init_mtx(&tp->t_outpoll.si_note, tp->t_mtx);
933 
934 	sx_xlock(&tty_list_sx);
935 	TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
936 	tty_list_count++;
937 	sx_xunlock(&tty_list_sx);
938 
939 	return (tp);
940 }
941 
942 static void
943 tty_dealloc(void *arg)
944 {
945 	struct tty *tp = arg;
946 
947 	sx_xlock(&tty_list_sx);
948 	TAILQ_REMOVE(&tty_list, tp, t_list);
949 	tty_list_count--;
950 	sx_xunlock(&tty_list_sx);
951 
952 	/* Make sure we haven't leaked buffers. */
953 	MPASS(ttyinq_getsize(&tp->t_inq) == 0);
954 	MPASS(ttyoutq_getsize(&tp->t_outq) == 0);
955 
956 	knlist_destroy(&tp->t_inpoll.si_note);
957 	knlist_destroy(&tp->t_outpoll.si_note);
958 
959 	cv_destroy(&tp->t_inwait);
960 	cv_destroy(&tp->t_outwait);
961 	cv_destroy(&tp->t_bgwait);
962 	cv_destroy(&tp->t_dcdwait);
963 	cv_destroy(&tp->t_outserwait);
964 
965 	if (tp->t_mtx == &tp->t_mtxobj)
966 		mtx_destroy(&tp->t_mtxobj);
967 	ttydevsw_free(tp);
968 	free(tp, M_TTY);
969 }
970 
971 static void
972 tty_rel_free(struct tty *tp)
973 {
974 	struct cdev *dev;
975 
976 	tty_lock_assert(tp, MA_OWNED);
977 
978 #define	TF_ACTIVITY	(TF_GONE|TF_OPENED|TF_HOOK|TF_OPENCLOSE)
979 	if (tp->t_sessioncnt != 0 || (tp->t_flags & TF_ACTIVITY) != TF_GONE) {
980 		/* TTY is still in use. */
981 		tty_unlock(tp);
982 		return;
983 	}
984 
985 	/* TTY can be deallocated. */
986 	dev = tp->t_dev;
987 	tp->t_dev = NULL;
988 	tty_unlock(tp);
989 
990 	destroy_dev_sched_cb(dev, tty_dealloc, tp);
991 }
992 
993 void
994 tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
995 {
996 	MPASS(tp->t_sessioncnt > 0);
997 	tty_lock_assert(tp, MA_OWNED);
998 
999 	if (tp->t_pgrp == pg)
1000 		tp->t_pgrp = NULL;
1001 
1002 	tty_unlock(tp);
1003 }
1004 
1005 void
1006 tty_rel_sess(struct tty *tp, struct session *sess)
1007 {
1008 	MPASS(tp->t_sessioncnt > 0);
1009 
1010 	/* Current session has left. */
1011 	if (tp->t_session == sess) {
1012 		tp->t_session = NULL;
1013 		MPASS(tp->t_pgrp == NULL);
1014 	}
1015 	tp->t_sessioncnt--;
1016 	tty_rel_free(tp);
1017 }
1018 
1019 void
1020 tty_rel_gone(struct tty *tp)
1021 {
1022 	MPASS(!tty_gone(tp));
1023 
1024 	/* Simulate carrier removal. */
1025 	ttydisc_modem(tp, 0);
1026 
1027 	/* Wake up all blocked threads. */
1028 	tty_wakeup(tp, FREAD|FWRITE);
1029 	cv_broadcast(&tp->t_bgwait);
1030 	cv_broadcast(&tp->t_dcdwait);
1031 
1032 	tp->t_flags |= TF_GONE;
1033 	tty_rel_free(tp);
1034 }
1035 
1036 /*
1037  * Exposing information about current TTY's through sysctl
1038  */
1039 
1040 static void
1041 tty_to_xtty(struct tty *tp, struct xtty *xt)
1042 {
1043 	tty_lock_assert(tp, MA_OWNED);
1044 
1045 	xt->xt_size = sizeof(struct xtty);
1046 	xt->xt_insize = ttyinq_getsize(&tp->t_inq);
1047 	xt->xt_incc = ttyinq_bytescanonicalized(&tp->t_inq);
1048 	xt->xt_inlc = ttyinq_bytesline(&tp->t_inq);
1049 	xt->xt_inlow = tp->t_inlow;
1050 	xt->xt_outsize = ttyoutq_getsize(&tp->t_outq);
1051 	xt->xt_outcc = ttyoutq_bytesused(&tp->t_outq);
1052 	xt->xt_outlow = tp->t_outlow;
1053 	xt->xt_column = tp->t_column;
1054 	xt->xt_pgid = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
1055 	xt->xt_sid = tp->t_session ? tp->t_session->s_sid : 0;
1056 	xt->xt_flags = tp->t_flags;
1057 	xt->xt_dev = tp->t_dev ? dev2udev(tp->t_dev) : NODEV;
1058 }
1059 
1060 static int
1061 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
1062 {
1063 	unsigned long lsize;
1064 	struct xtty *xtlist, *xt;
1065 	struct tty *tp;
1066 	int error;
1067 
1068 	sx_slock(&tty_list_sx);
1069 	lsize = tty_list_count * sizeof(struct xtty);
1070 	if (lsize == 0) {
1071 		sx_sunlock(&tty_list_sx);
1072 		return (0);
1073 	}
1074 
1075 	xtlist = xt = malloc(lsize, M_TTY, M_WAITOK);
1076 
1077 	TAILQ_FOREACH(tp, &tty_list, t_list) {
1078 		tty_lock(tp);
1079 		tty_to_xtty(tp, xt);
1080 		tty_unlock(tp);
1081 		xt++;
1082 	}
1083 	sx_sunlock(&tty_list_sx);
1084 
1085 	error = SYSCTL_OUT(req, xtlist, lsize);
1086 	free(xtlist, M_TTY);
1087 	return (error);
1088 }
1089 
1090 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
1091 	0, 0, sysctl_kern_ttys, "S,xtty", "List of TTYs");
1092 
1093 /*
1094  * Device node creation. Device has been set up, now we can expose it to
1095  * the user.
1096  */
1097 
1098 void
1099 tty_makedev(struct tty *tp, struct ucred *cred, const char *fmt, ...)
1100 {
1101 	va_list ap;
1102 	struct cdev *dev;
1103 	const char *prefix = "tty";
1104 	char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
1105 	uid_t uid;
1106 	gid_t gid;
1107 	mode_t mode;
1108 
1109 	/* Remove "tty" prefix from devices like PTY's. */
1110 	if (tp->t_flags & TF_NOPREFIX)
1111 		prefix = "";
1112 
1113 	va_start(ap, fmt);
1114 	vsnrprintf(name, sizeof name, 32, fmt, ap);
1115 	va_end(ap);
1116 
1117 	if (cred == NULL) {
1118 		/* System device. */
1119 		uid = UID_ROOT;
1120 		gid = GID_WHEEL;
1121 		mode = S_IRUSR|S_IWUSR;
1122 	} else {
1123 		/* User device. */
1124 		uid = cred->cr_ruid;
1125 		gid = GID_TTY;
1126 		mode = S_IRUSR|S_IWUSR|S_IWGRP;
1127 	}
1128 
1129 	/* Master call-in device. */
1130 	dev = make_dev_cred(&ttydev_cdevsw, 0, cred,
1131 	    uid, gid, mode, "%s%s", prefix, name);
1132 	dev->si_drv1 = tp;
1133 	tp->t_dev = dev;
1134 
1135 	/* Slave call-in devices. */
1136 	if (tp->t_flags & TF_INITLOCK) {
1137 		dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1138 		    uid, gid, mode, "%s%s.init", prefix, name);
1139 		dev_depends(tp->t_dev, dev);
1140 		dev->si_drv1 = tp;
1141 		dev->si_drv2 = &tp->t_termios_init_in;
1142 
1143 		dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1144 		    uid, gid, mode, "%s%s.lock", prefix, name);
1145 		dev_depends(tp->t_dev, dev);
1146 		dev->si_drv1 = tp;
1147 		dev->si_drv2 = &tp->t_termios_lock_in;
1148 	}
1149 
1150 	/* Call-out devices. */
1151 	if (tp->t_flags & TF_CALLOUT) {
1152 		dev = make_dev_cred(&ttydev_cdevsw, 0, cred,
1153 		    UID_UUCP, GID_DIALER, 0660, "cua%s", name);
1154 		dev_depends(tp->t_dev, dev);
1155 		dev->si_drv1 = tp;
1156 
1157 		/* Slave call-out devices. */
1158 		if (tp->t_flags & TF_INITLOCK) {
1159 			dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1160 			    UID_UUCP, GID_DIALER, 0660, "cua%s.init", name);
1161 			dev_depends(tp->t_dev, dev);
1162 			dev->si_drv1 = tp;
1163 			dev->si_drv2 = &tp->t_termios_init_out;
1164 
1165 			dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1166 			    UID_UUCP, GID_DIALER, 0660, "cua%s.lock", name);
1167 			dev_depends(tp->t_dev, dev);
1168 			dev->si_drv1 = tp;
1169 			dev->si_drv2 = &tp->t_termios_lock_out;
1170 		}
1171 	}
1172 }
1173 
1174 /*
1175  * Signalling processes.
1176  */
1177 
1178 void
1179 tty_signal_sessleader(struct tty *tp, int sig)
1180 {
1181 	struct proc *p;
1182 
1183 	tty_lock_assert(tp, MA_OWNED);
1184 	MPASS(sig >= 1 && sig < NSIG);
1185 
1186 	/* Make signals start output again. */
1187 	tp->t_flags &= ~TF_STOPPED;
1188 
1189 	if (tp->t_session != NULL && tp->t_session->s_leader != NULL) {
1190 		p = tp->t_session->s_leader;
1191 		PROC_LOCK(p);
1192 		psignal(p, sig);
1193 		PROC_UNLOCK(p);
1194 	}
1195 }
1196 
1197 void
1198 tty_signal_pgrp(struct tty *tp, int sig)
1199 {
1200 	tty_lock_assert(tp, MA_OWNED);
1201 	MPASS(sig >= 1 && sig < NSIG);
1202 
1203 	/* Make signals start output again. */
1204 	tp->t_flags &= ~TF_STOPPED;
1205 
1206 	if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
1207 		tty_info(tp);
1208 	if (tp->t_pgrp != NULL) {
1209 		PGRP_LOCK(tp->t_pgrp);
1210 		pgsignal(tp->t_pgrp, sig, 1);
1211 		PGRP_UNLOCK(tp->t_pgrp);
1212 	}
1213 }
1214 
1215 void
1216 tty_wakeup(struct tty *tp, int flags)
1217 {
1218 	if (tp->t_flags & TF_ASYNC && tp->t_sigio != NULL)
1219 		pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
1220 
1221 	if (flags & FWRITE) {
1222 		cv_broadcast(&tp->t_outwait);
1223 		selwakeup(&tp->t_outpoll);
1224 		KNOTE_LOCKED(&tp->t_outpoll.si_note, 0);
1225 	}
1226 	if (flags & FREAD) {
1227 		cv_broadcast(&tp->t_inwait);
1228 		selwakeup(&tp->t_inpoll);
1229 		KNOTE_LOCKED(&tp->t_inpoll.si_note, 0);
1230 	}
1231 }
1232 
1233 int
1234 tty_wait(struct tty *tp, struct cv *cv)
1235 {
1236 	int error;
1237 	int revokecnt = tp->t_revokecnt;
1238 
1239 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1240 	MPASS(!tty_gone(tp));
1241 
1242 	error = cv_wait_sig(cv, tp->t_mtx);
1243 
1244 	/* Restart the system call when we may have been revoked. */
1245 	if (tp->t_revokecnt != revokecnt)
1246 		return (ERESTART);
1247 
1248 	/* Bail out when the device slipped away. */
1249 	if (tty_gone(tp))
1250 		return (ENXIO);
1251 
1252 	return (error);
1253 }
1254 
1255 int
1256 tty_timedwait(struct tty *tp, struct cv *cv, int hz)
1257 {
1258 	int error;
1259 	int revokecnt = tp->t_revokecnt;
1260 
1261 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1262 	MPASS(!tty_gone(tp));
1263 
1264 	error = cv_timedwait_sig(cv, tp->t_mtx, hz);
1265 
1266 	/* Restart the system call when we may have been revoked. */
1267 	if (tp->t_revokecnt != revokecnt)
1268 		return (ERESTART);
1269 
1270 	/* Bail out when the device slipped away. */
1271 	if (tty_gone(tp))
1272 		return (ENXIO);
1273 
1274 	return (error);
1275 }
1276 
1277 void
1278 tty_flush(struct tty *tp, int flags)
1279 {
1280 	if (flags & FWRITE) {
1281 		tp->t_flags &= ~TF_HIWAT_OUT;
1282 		ttyoutq_flush(&tp->t_outq);
1283 		tty_wakeup(tp, FWRITE);
1284 		ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
1285 	}
1286 	if (flags & FREAD) {
1287 		tty_hiwat_in_unblock(tp);
1288 		ttyinq_flush(&tp->t_inq);
1289 		ttydevsw_inwakeup(tp);
1290 		ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
1291 	}
1292 }
1293 
1294 static int
1295 tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, struct thread *td)
1296 {
1297 	int error;
1298 
1299 	switch (cmd) {
1300 	/*
1301 	 * Modem commands.
1302 	 * The SER_* and TIOCM_* flags are the same, but one bit
1303 	 * shifted. I don't know why.
1304 	 */
1305 	case TIOCSDTR:
1306 		ttydevsw_modem(tp, SER_DTR, 0);
1307 		return (0);
1308 	case TIOCCDTR:
1309 		ttydevsw_modem(tp, 0, SER_DTR);
1310 		return (0);
1311 	case TIOCMSET: {
1312 		int bits = *(int *)data;
1313 		ttydevsw_modem(tp,
1314 		    (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1,
1315 		    ((~bits) & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1316 		return (0);
1317 	}
1318 	case TIOCMBIS: {
1319 		int bits = *(int *)data;
1320 		ttydevsw_modem(tp, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1, 0);
1321 		return (0);
1322 	}
1323 	case TIOCMBIC: {
1324 		int bits = *(int *)data;
1325 		ttydevsw_modem(tp, 0, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1326 		return (0);
1327 	}
1328 	case TIOCMGET:
1329 		*(int *)data = TIOCM_LE + (ttydevsw_modem(tp, 0, 0) << 1);
1330 		return (0);
1331 
1332 	case FIOASYNC:
1333 		if (*(int *)data)
1334 			tp->t_flags |= TF_ASYNC;
1335 		else
1336 			tp->t_flags &= ~TF_ASYNC;
1337 		return (0);
1338 	case FIONBIO:
1339 		/* This device supports non-blocking operation. */
1340 		return (0);
1341 	case FIONREAD:
1342 		*(int *)data = ttyinq_bytescanonicalized(&tp->t_inq);
1343 		return (0);
1344 	case FIONWRITE:
1345 	case TIOCOUTQ:
1346 		*(int *)data = ttyoutq_bytesused(&tp->t_outq);
1347 		return (0);
1348 	case FIOSETOWN:
1349 		if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1350 			/* Not allowed to set ownership. */
1351 			return (ENOTTY);
1352 
1353 		/* Temporarily unlock the TTY to set ownership. */
1354 		tty_unlock(tp);
1355 		error = fsetown(*(int *)data, &tp->t_sigio);
1356 		tty_lock(tp);
1357 		return (error);
1358 	case FIOGETOWN:
1359 		if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1360 			/* Not allowed to set ownership. */
1361 			return (ENOTTY);
1362 
1363 		/* Get ownership. */
1364 		*(int *)data = fgetown(&tp->t_sigio);
1365 		return (0);
1366 	case TIOCGETA:
1367 		/* Obtain terminal flags through tcgetattr(). */
1368 		*(struct termios*)data = tp->t_termios;
1369 		return (0);
1370 	case TIOCSETA:
1371 	case TIOCSETAW:
1372 	case TIOCSETAF: {
1373 		struct termios *t = data;
1374 
1375 		/*
1376 		 * Who makes up these funny rules? According to POSIX,
1377 		 * input baud rate is set equal to the output baud rate
1378 		 * when zero.
1379 		 */
1380 		if (t->c_ispeed == 0)
1381 			t->c_ispeed = t->c_ospeed;
1382 
1383 		/* Discard any unsupported bits. */
1384 		t->c_iflag &= TTYSUP_IFLAG;
1385 		t->c_oflag &= TTYSUP_OFLAG;
1386 		t->c_lflag &= TTYSUP_LFLAG;
1387 		t->c_cflag &= TTYSUP_CFLAG;
1388 
1389 		/* Set terminal flags through tcsetattr(). */
1390 		if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
1391 			error = tty_drain(tp);
1392 			if (error)
1393 				return (error);
1394 			if (cmd == TIOCSETAF)
1395 				tty_flush(tp, FREAD);
1396 		}
1397 
1398 		/*
1399 		 * Only call param() when the flags really change.
1400 		 */
1401 		if ((t->c_cflag & CIGNORE) == 0 &&
1402 		    (tp->t_termios.c_cflag != t->c_cflag ||
1403 		    tp->t_termios.c_ispeed != t->c_ispeed ||
1404 		    tp->t_termios.c_ospeed != t->c_ospeed)) {
1405 			error = ttydevsw_param(tp, t);
1406 			if (error)
1407 				return (error);
1408 
1409 			/* XXX: CLOCAL? */
1410 
1411 			tp->t_termios.c_cflag = t->c_cflag & ~CIGNORE;
1412 			tp->t_termios.c_ispeed = t->c_ispeed;
1413 			tp->t_termios.c_ospeed = t->c_ospeed;
1414 
1415 			/* Baud rate has changed - update watermarks. */
1416 			tty_watermarks(tp);
1417 		}
1418 
1419 		/* Copy new non-device driver parameters. */
1420 		tp->t_termios.c_iflag = t->c_iflag;
1421 		tp->t_termios.c_oflag = t->c_oflag;
1422 		tp->t_termios.c_lflag = t->c_lflag;
1423 		memcpy(&tp->t_termios.c_cc, t->c_cc, sizeof t->c_cc);
1424 
1425 		ttydisc_optimize(tp);
1426 
1427 		if ((t->c_lflag & ICANON) == 0) {
1428 			/*
1429 			 * When in non-canonical mode, wake up all
1430 			 * readers. Canonicalize any partial input. VMIN
1431 			 * and VTIME could also be adjusted.
1432 			 */
1433 			ttyinq_canonicalize(&tp->t_inq);
1434 			tty_wakeup(tp, FREAD);
1435 		}
1436 
1437 		/*
1438 		 * For packet mode: notify the PTY consumer that VSTOP
1439 		 * and VSTART may have been changed.
1440 		 */
1441 		if (tp->t_termios.c_iflag & IXON &&
1442 		    tp->t_termios.c_cc[VSTOP] == CTRL('S') &&
1443 		    tp->t_termios.c_cc[VSTART] == CTRL('Q'))
1444 			ttydevsw_pktnotify(tp, TIOCPKT_DOSTOP);
1445 		else
1446 			ttydevsw_pktnotify(tp, TIOCPKT_NOSTOP);
1447 		return (0);
1448 	}
1449 	case TIOCGETD:
1450 		/* For compatibility - we only support TTYDISC. */
1451 		*(int *)data = TTYDISC;
1452 		return (0);
1453 	case TIOCGPGRP:
1454 		if (!tty_is_ctty(tp, td->td_proc))
1455 			return (ENOTTY);
1456 
1457 		if (tp->t_pgrp != NULL)
1458 			*(int *)data = tp->t_pgrp->pg_id;
1459 		else
1460 			*(int *)data = NO_PID;
1461 		return (0);
1462 	case TIOCGSID:
1463 		if (!tty_is_ctty(tp, td->td_proc))
1464 			return (ENOTTY);
1465 
1466 		MPASS(tp->t_session);
1467 		*(int *)data = tp->t_session->s_sid;
1468 		return (0);
1469 	case TIOCSCTTY: {
1470 		struct proc *p = td->td_proc;
1471 
1472 		/* XXX: This looks awful. */
1473 		tty_unlock(tp);
1474 		sx_xlock(&proctree_lock);
1475 		tty_lock(tp);
1476 
1477 		if (!SESS_LEADER(p)) {
1478 			/* Only the session leader may do this. */
1479 			sx_xunlock(&proctree_lock);
1480 			return (EPERM);
1481 		}
1482 
1483 		if (tp->t_session != NULL && tp->t_session == p->p_session) {
1484 			/* This is already our controlling TTY. */
1485 			sx_xunlock(&proctree_lock);
1486 			return (0);
1487 		}
1488 
1489 		if (p->p_session->s_ttyp != NULL ||
1490 		    (tp->t_session != NULL && tp->t_session->s_ttyvp != NULL &&
1491 		    tp->t_session->s_ttyvp->v_type != VBAD)) {
1492 			/*
1493 			 * There is already a relation between a TTY and
1494 			 * a session, or the caller is not the session
1495 			 * leader.
1496 			 *
1497 			 * Allow the TTY to be stolen when the vnode is
1498 			 * invalid, but the reference to the TTY is
1499 			 * still active.  This allows immediate reuse of
1500 			 * TTYs of which the session leader has been
1501 			 * killed or the TTY revoked.
1502 			 */
1503 			sx_xunlock(&proctree_lock);
1504 			return (EPERM);
1505 		}
1506 
1507 		/* Connect the session to the TTY. */
1508 		tp->t_session = p->p_session;
1509 		tp->t_session->s_ttyp = tp;
1510 		tp->t_sessioncnt++;
1511 		sx_xunlock(&proctree_lock);
1512 
1513 		/* Assign foreground process group. */
1514 		tp->t_pgrp = p->p_pgrp;
1515 		PROC_LOCK(p);
1516 		p->p_flag |= P_CONTROLT;
1517 		PROC_UNLOCK(p);
1518 
1519 		return (0);
1520 	}
1521 	case TIOCSPGRP: {
1522 		struct pgrp *pg;
1523 
1524 		/*
1525 		 * XXX: Temporarily unlock the TTY to locate the process
1526 		 * group. This code would be lot nicer if we would ever
1527 		 * decompose proctree_lock.
1528 		 */
1529 		tty_unlock(tp);
1530 		sx_slock(&proctree_lock);
1531 		pg = pgfind(*(int *)data);
1532 		if (pg != NULL)
1533 			PGRP_UNLOCK(pg);
1534 		if (pg == NULL || pg->pg_session != td->td_proc->p_session) {
1535 			sx_sunlock(&proctree_lock);
1536 			tty_lock(tp);
1537 			return (EPERM);
1538 		}
1539 		tty_lock(tp);
1540 
1541 		/*
1542 		 * Determine if this TTY is the controlling TTY after
1543 		 * relocking the TTY.
1544 		 */
1545 		if (!tty_is_ctty(tp, td->td_proc)) {
1546 			sx_sunlock(&proctree_lock);
1547 			return (ENOTTY);
1548 		}
1549 		tp->t_pgrp = pg;
1550 		sx_sunlock(&proctree_lock);
1551 
1552 		/* Wake up the background process groups. */
1553 		cv_broadcast(&tp->t_bgwait);
1554 		return (0);
1555 	}
1556 	case TIOCFLUSH: {
1557 		int flags = *(int *)data;
1558 
1559 		if (flags == 0)
1560 			flags = (FREAD|FWRITE);
1561 		else
1562 			flags &= (FREAD|FWRITE);
1563 		tty_flush(tp, flags);
1564 		return (0);
1565 	}
1566 	case TIOCDRAIN:
1567 		/* Drain TTY output. */
1568 		return tty_drain(tp);
1569 	case TIOCCONS:
1570 		/* Set terminal as console TTY. */
1571 		if (*(int *)data) {
1572 			error = priv_check(td, PRIV_TTY_CONSOLE);
1573 			if (error)
1574 				return (error);
1575 
1576 			/*
1577 			 * XXX: constty should really need to be locked!
1578 			 * XXX: allow disconnected constty's to be stolen!
1579 			 */
1580 
1581 			if (constty == tp)
1582 				return (0);
1583 			if (constty != NULL)
1584 				return (EBUSY);
1585 
1586 			tty_unlock(tp);
1587 			constty_set(tp);
1588 			tty_lock(tp);
1589 		} else if (constty == tp) {
1590 			constty_clear();
1591 		}
1592 		return (0);
1593 	case TIOCGWINSZ:
1594 		/* Obtain window size. */
1595 		*(struct winsize*)data = tp->t_winsize;
1596 		return (0);
1597 	case TIOCSWINSZ:
1598 		/* Set window size. */
1599 		if (bcmp(&tp->t_winsize, data, sizeof(struct winsize)) == 0)
1600 			return (0);
1601 		tp->t_winsize = *(struct winsize*)data;
1602 		tty_signal_pgrp(tp, SIGWINCH);
1603 		return (0);
1604 	case TIOCEXCL:
1605 		tp->t_flags |= TF_EXCLUDE;
1606 		return (0);
1607 	case TIOCNXCL:
1608 		tp->t_flags &= ~TF_EXCLUDE;
1609 		return (0);
1610 	case TIOCSTOP:
1611 		tp->t_flags |= TF_STOPPED;
1612 		ttydevsw_pktnotify(tp, TIOCPKT_STOP);
1613 		return (0);
1614 	case TIOCSTART:
1615 		tp->t_flags &= ~TF_STOPPED;
1616 		ttydevsw_outwakeup(tp);
1617 		ttydevsw_pktnotify(tp, TIOCPKT_START);
1618 		return (0);
1619 	case TIOCSTAT:
1620 		tty_info(tp);
1621 		return (0);
1622 	}
1623 
1624 #ifdef COMPAT_43TTY
1625 	return tty_ioctl_compat(tp, cmd, data, td);
1626 #else /* !COMPAT_43TTY */
1627 	return (ENOIOCTL);
1628 #endif /* COMPAT_43TTY */
1629 }
1630 
1631 int
1632 tty_ioctl(struct tty *tp, u_long cmd, void *data, struct thread *td)
1633 {
1634 	int error;
1635 
1636 	tty_lock_assert(tp, MA_OWNED);
1637 
1638 	if (tty_gone(tp))
1639 		return (ENXIO);
1640 
1641 	error = ttydevsw_ioctl(tp, cmd, data, td);
1642 	if (error == ENOIOCTL)
1643 		error = tty_generic_ioctl(tp, cmd, data, td);
1644 
1645 	return (error);
1646 }
1647 
1648 dev_t
1649 tty_udev(struct tty *tp)
1650 {
1651 	if (tp->t_dev)
1652 		return dev2udev(tp->t_dev);
1653 	else
1654 		return NODEV;
1655 }
1656 
1657 int
1658 tty_checkoutq(struct tty *tp)
1659 {
1660 
1661 	/* 256 bytes should be enough to print a log message. */
1662 	return (ttyoutq_bytesleft(&tp->t_outq) >= 256);
1663 }
1664 
1665 void
1666 tty_hiwat_in_block(struct tty *tp)
1667 {
1668 
1669 	if ((tp->t_flags & TF_HIWAT_IN) == 0 &&
1670 	    tp->t_termios.c_iflag & IXOFF &&
1671 	    tp->t_termios.c_cc[VSTOP] != _POSIX_VDISABLE) {
1672 		/*
1673 		 * Input flow control. Only enter the high watermark when we
1674 		 * can successfully store the VSTOP character.
1675 		 */
1676 		if (ttyoutq_write_nofrag(&tp->t_outq,
1677 		    &tp->t_termios.c_cc[VSTOP], 1) == 0)
1678 			tp->t_flags |= TF_HIWAT_IN;
1679 	} else {
1680 		/* No input flow control. */
1681 		tp->t_flags |= TF_HIWAT_IN;
1682 	}
1683 }
1684 
1685 void
1686 tty_hiwat_in_unblock(struct tty *tp)
1687 {
1688 
1689 	if (tp->t_flags & TF_HIWAT_IN &&
1690 	    tp->t_termios.c_iflag & IXOFF &&
1691 	    tp->t_termios.c_cc[VSTART] != _POSIX_VDISABLE) {
1692 		/*
1693 		 * Input flow control. Only leave the high watermark when we
1694 		 * can successfully store the VSTART character.
1695 		 */
1696 		if (ttyoutq_write_nofrag(&tp->t_outq,
1697 		    &tp->t_termios.c_cc[VSTART], 1) == 0)
1698 			tp->t_flags &= ~TF_HIWAT_IN;
1699 	} else {
1700 		/* No input flow control. */
1701 		tp->t_flags &= ~TF_HIWAT_IN;
1702 	}
1703 
1704 	if (!tty_gone(tp))
1705 		ttydevsw_inwakeup(tp);
1706 }
1707 
1708 /*
1709  * TTY hooks interface.
1710  */
1711 
1712 static int
1713 ttyhook_defrint(struct tty *tp, char c, int flags)
1714 {
1715 
1716 	if (ttyhook_rint_bypass(tp, &c, 1) != 1)
1717 		return (-1);
1718 
1719 	return (0);
1720 }
1721 
1722 int
1723 ttyhook_register(struct tty **rtp, struct proc *p, int fd,
1724     struct ttyhook *th, void *softc)
1725 {
1726 	struct tty *tp;
1727 	struct file *fp;
1728 	struct cdev *dev;
1729 	struct cdevsw *cdp;
1730 	struct filedesc *fdp;
1731 	int error;
1732 
1733 	/* Validate the file descriptor. */
1734 	if ((fdp = p->p_fd) == NULL)
1735 		return (EBADF);
1736 
1737 	fp = fget_unlocked(fdp, fd);
1738 	if (fp == NULL)
1739 		return (EBADF);
1740 	if (fp->f_ops == &badfileops) {
1741 		error = EBADF;
1742 		goto done1;
1743 	}
1744 
1745 	/*
1746 	 * Make sure the vnode is bound to a character device.
1747 	 * Unlocked check for the vnode type is ok there, because we
1748 	 * only shall prevent calling devvn_refthread on the file that
1749 	 * never has been opened over a character device.
1750 	 */
1751 	if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR) {
1752 		error = EINVAL;
1753 		goto done1;
1754 	}
1755 
1756 	/* Make sure it is a TTY. */
1757 	cdp = devvn_refthread(fp->f_vnode, &dev);
1758 	if (cdp == NULL) {
1759 		error = ENXIO;
1760 		goto done1;
1761 	}
1762 	if (dev != fp->f_data) {
1763 		error = ENXIO;
1764 		goto done2;
1765 	}
1766 	if (cdp != &ttydev_cdevsw) {
1767 		error = ENOTTY;
1768 		goto done2;
1769 	}
1770 	tp = dev->si_drv1;
1771 
1772 	/* Try to attach the hook to the TTY. */
1773 	error = EBUSY;
1774 	tty_lock(tp);
1775 	MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
1776 	if (tp->t_flags & TF_HOOK)
1777 		goto done3;
1778 
1779 	tp->t_flags |= TF_HOOK;
1780 	tp->t_hook = th;
1781 	tp->t_hooksoftc = softc;
1782 	*rtp = tp;
1783 	error = 0;
1784 
1785 	/* Maybe we can switch into bypass mode now. */
1786 	ttydisc_optimize(tp);
1787 
1788 	/* Silently convert rint() calls to rint_bypass() when possible. */
1789 	if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
1790 		th->th_rint = ttyhook_defrint;
1791 
1792 done3:	tty_unlock(tp);
1793 done2:	dev_relthread(dev);
1794 done1:	fdrop(fp, curthread);
1795 	return (error);
1796 }
1797 
1798 void
1799 ttyhook_unregister(struct tty *tp)
1800 {
1801 
1802 	tty_lock_assert(tp, MA_OWNED);
1803 	MPASS(tp->t_flags & TF_HOOK);
1804 
1805 	/* Disconnect the hook. */
1806 	tp->t_flags &= ~TF_HOOK;
1807 	tp->t_hook = NULL;
1808 
1809 	/* Maybe we need to leave bypass mode. */
1810 	ttydisc_optimize(tp);
1811 
1812 	/* Maybe deallocate the TTY as well. */
1813 	tty_rel_free(tp);
1814 }
1815 
1816 /*
1817  * /dev/console handling.
1818  */
1819 
1820 static int
1821 ttyconsdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
1822 {
1823 	struct tty *tp;
1824 
1825 	/* System has no console device. */
1826 	if (dev_console_filename == NULL)
1827 		return (ENXIO);
1828 
1829 	/* Look up corresponding TTY by device name. */
1830 	sx_slock(&tty_list_sx);
1831 	TAILQ_FOREACH(tp, &tty_list, t_list) {
1832 		if (strcmp(dev_console_filename, tty_devname(tp)) == 0) {
1833 			dev_console->si_drv1 = tp;
1834 			break;
1835 		}
1836 	}
1837 	sx_sunlock(&tty_list_sx);
1838 
1839 	/* System console has no TTY associated. */
1840 	if (dev_console->si_drv1 == NULL)
1841 		return (ENXIO);
1842 
1843 	return (ttydev_open(dev, oflags, devtype, td));
1844 }
1845 
1846 static int
1847 ttyconsdev_write(struct cdev *dev, struct uio *uio, int ioflag)
1848 {
1849 
1850 	log_console(uio);
1851 
1852 	return (ttydev_write(dev, uio, ioflag));
1853 }
1854 
1855 /*
1856  * /dev/console is a little different than normal TTY's.  When opened,
1857  * it determines which TTY to use.  When data gets written to it, it
1858  * will be logged in the kernel message buffer.
1859  */
1860 static struct cdevsw ttyconsdev_cdevsw = {
1861 	.d_version	= D_VERSION,
1862 	.d_open		= ttyconsdev_open,
1863 	.d_close	= ttydev_close,
1864 	.d_read		= ttydev_read,
1865 	.d_write	= ttyconsdev_write,
1866 	.d_ioctl	= ttydev_ioctl,
1867 	.d_kqfilter	= ttydev_kqfilter,
1868 	.d_poll		= ttydev_poll,
1869 	.d_mmap		= ttydev_mmap,
1870 	.d_name		= "ttyconsdev",
1871 	.d_flags	= D_TTY,
1872 };
1873 
1874 static void
1875 ttyconsdev_init(void *unused)
1876 {
1877 
1878 	dev_console = make_dev(&ttyconsdev_cdevsw, 0, UID_ROOT, GID_WHEEL,
1879 	    0600, "console");
1880 }
1881 
1882 SYSINIT(tty, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyconsdev_init, NULL);
1883 
1884 void
1885 ttyconsdev_select(const char *name)
1886 {
1887 
1888 	dev_console_filename = name;
1889 }
1890 
1891 /*
1892  * Debugging routines.
1893  */
1894 
1895 #include "opt_ddb.h"
1896 #ifdef DDB
1897 #include <ddb/ddb.h>
1898 #include <ddb/db_sym.h>
1899 
1900 static struct {
1901 	int flag;
1902 	char val;
1903 } ttystates[] = {
1904 #if 0
1905 	{ TF_NOPREFIX,		'N' },
1906 #endif
1907 	{ TF_INITLOCK,		'I' },
1908 	{ TF_CALLOUT,		'C' },
1909 
1910 	/* Keep these together -> 'Oi' and 'Oo'. */
1911 	{ TF_OPENED,		'O' },
1912 	{ TF_OPENED_IN,		'i' },
1913 	{ TF_OPENED_OUT,	'o' },
1914 	{ TF_OPENED_CONS,	'c' },
1915 
1916 	{ TF_GONE,		'G' },
1917 	{ TF_OPENCLOSE,		'B' },
1918 	{ TF_ASYNC,		'Y' },
1919 	{ TF_LITERAL,		'L' },
1920 
1921 	/* Keep these together -> 'Hi' and 'Ho'. */
1922 	{ TF_HIWAT,		'H' },
1923 	{ TF_HIWAT_IN,		'i' },
1924 	{ TF_HIWAT_OUT,		'o' },
1925 
1926 	{ TF_STOPPED,		'S' },
1927 	{ TF_EXCLUDE,		'X' },
1928 	{ TF_BYPASS,		'l' },
1929 	{ TF_ZOMBIE,		'Z' },
1930 	{ TF_HOOK,		's' },
1931 
1932 	/* Keep these together -> 'bi' and 'bo'. */
1933 	{ TF_BUSY,		'b' },
1934 	{ TF_BUSY_IN,		'i' },
1935 	{ TF_BUSY_OUT,		'o' },
1936 
1937 	{ 0,			'\0'},
1938 };
1939 
1940 #define	TTY_FLAG_BITS \
1941 	"\20\1NOPREFIX\2INITLOCK\3CALLOUT\4OPENED_IN\5OPENED_OUT\6GONE" \
1942 	"\7OPENCLOSE\10ASYNC\11LITERAL\12HIWAT_IN\13HIWAT_OUT\14STOPPED" \
1943 	"\15EXCLUDE\16BYPASS\17ZOMBIE\20HOOK"
1944 
1945 #define DB_PRINTSYM(name, addr) \
1946 	db_printf("%s  " #name ": ", sep); \
1947 	db_printsym((db_addr_t) addr, DB_STGY_ANY); \
1948 	db_printf("\n");
1949 
1950 static void
1951 _db_show_devsw(const char *sep, const struct ttydevsw *tsw)
1952 {
1953 	db_printf("%sdevsw: ", sep);
1954 	db_printsym((db_addr_t)tsw, DB_STGY_ANY);
1955 	db_printf(" (%p)\n", tsw);
1956 	DB_PRINTSYM(open, tsw->tsw_open);
1957 	DB_PRINTSYM(close, tsw->tsw_close);
1958 	DB_PRINTSYM(outwakeup, tsw->tsw_outwakeup);
1959 	DB_PRINTSYM(inwakeup, tsw->tsw_inwakeup);
1960 	DB_PRINTSYM(ioctl, tsw->tsw_ioctl);
1961 	DB_PRINTSYM(param, tsw->tsw_param);
1962 	DB_PRINTSYM(modem, tsw->tsw_modem);
1963 	DB_PRINTSYM(mmap, tsw->tsw_mmap);
1964 	DB_PRINTSYM(pktnotify, tsw->tsw_pktnotify);
1965 	DB_PRINTSYM(free, tsw->tsw_free);
1966 }
1967 static void
1968 _db_show_hooks(const char *sep, const struct ttyhook *th)
1969 {
1970 	db_printf("%shook: ", sep);
1971 	db_printsym((db_addr_t)th, DB_STGY_ANY);
1972 	db_printf(" (%p)\n", th);
1973 	if (th == NULL)
1974 		return;
1975 	DB_PRINTSYM(rint, th->th_rint);
1976 	DB_PRINTSYM(rint_bypass, th->th_rint_bypass);
1977 	DB_PRINTSYM(rint_done, th->th_rint_done);
1978 	DB_PRINTSYM(rint_poll, th->th_rint_poll);
1979 	DB_PRINTSYM(getc_inject, th->th_getc_inject);
1980 	DB_PRINTSYM(getc_capture, th->th_getc_capture);
1981 	DB_PRINTSYM(getc_poll, th->th_getc_poll);
1982 	DB_PRINTSYM(close, th->th_close);
1983 }
1984 
1985 static void
1986 _db_show_termios(const char *name, const struct termios *t)
1987 {
1988 
1989 	db_printf("%s: iflag 0x%x oflag 0x%x cflag 0x%x "
1990 	    "lflag 0x%x ispeed %u ospeed %u\n", name,
1991 	    t->c_iflag, t->c_oflag, t->c_cflag, t->c_lflag,
1992 	    t->c_ispeed, t->c_ospeed);
1993 }
1994 
1995 /* DDB command to show TTY statistics. */
1996 DB_SHOW_COMMAND(tty, db_show_tty)
1997 {
1998 	struct tty *tp;
1999 
2000 	if (!have_addr) {
2001 		db_printf("usage: show tty <addr>\n");
2002 		return;
2003 	}
2004 	tp = (struct tty *)addr;
2005 
2006 	db_printf("0x%p: %s\n", tp, tty_devname(tp));
2007 	db_printf("\tmtx: %p\n", tp->t_mtx);
2008 	db_printf("\tflags: %b\n", tp->t_flags, TTY_FLAG_BITS);
2009 	db_printf("\trevokecnt: %u\n", tp->t_revokecnt);
2010 
2011 	/* Buffering mechanisms. */
2012 	db_printf("\tinq: %p begin %u linestart %u reprint %u end %u "
2013 	    "nblocks %u quota %u\n", &tp->t_inq, tp->t_inq.ti_begin,
2014 	    tp->t_inq.ti_linestart, tp->t_inq.ti_reprint, tp->t_inq.ti_end,
2015 	    tp->t_inq.ti_nblocks, tp->t_inq.ti_quota);
2016 	db_printf("\toutq: %p begin %u end %u nblocks %u quota %u\n",
2017 	    &tp->t_outq, tp->t_outq.to_begin, tp->t_outq.to_end,
2018 	    tp->t_outq.to_nblocks, tp->t_outq.to_quota);
2019 	db_printf("\tinlow: %zu\n", tp->t_inlow);
2020 	db_printf("\toutlow: %zu\n", tp->t_outlow);
2021 	_db_show_termios("\ttermios", &tp->t_termios);
2022 	db_printf("\twinsize: row %u col %u xpixel %u ypixel %u\n",
2023 	    tp->t_winsize.ws_row, tp->t_winsize.ws_col,
2024 	    tp->t_winsize.ws_xpixel, tp->t_winsize.ws_ypixel);
2025 	db_printf("\tcolumn: %u\n", tp->t_column);
2026 	db_printf("\twritepos: %u\n", tp->t_writepos);
2027 	db_printf("\tcompatflags: 0x%x\n", tp->t_compatflags);
2028 
2029 	/* Init/lock-state devices. */
2030 	_db_show_termios("\ttermios_init_in", &tp->t_termios_init_in);
2031 	_db_show_termios("\ttermios_init_out", &tp->t_termios_init_out);
2032 	_db_show_termios("\ttermios_lock_in", &tp->t_termios_lock_in);
2033 	_db_show_termios("\ttermios_lock_out", &tp->t_termios_lock_out);
2034 
2035 	/* Hooks */
2036 	_db_show_devsw("\t", tp->t_devsw);
2037 	_db_show_hooks("\t", tp->t_hook);
2038 
2039 	/* Process info. */
2040 	db_printf("\tpgrp: %p gid %d jobc %d\n", tp->t_pgrp,
2041 	    tp->t_pgrp ? tp->t_pgrp->pg_id : 0,
2042 	    tp->t_pgrp ? tp->t_pgrp->pg_jobc : 0);
2043 	db_printf("\tsession: %p", tp->t_session);
2044 	if (tp->t_session != NULL)
2045 	    db_printf(" count %u leader %p tty %p sid %d login %s",
2046 		tp->t_session->s_count, tp->t_session->s_leader,
2047 		tp->t_session->s_ttyp, tp->t_session->s_sid,
2048 		tp->t_session->s_login);
2049 	db_printf("\n");
2050 	db_printf("\tsessioncnt: %u\n", tp->t_sessioncnt);
2051 	db_printf("\tdevswsoftc: %p\n", tp->t_devswsoftc);
2052 	db_printf("\thooksoftc: %p\n", tp->t_hooksoftc);
2053 	db_printf("\tdev: %p\n", tp->t_dev);
2054 }
2055 
2056 /* DDB command to list TTYs. */
2057 DB_SHOW_ALL_COMMAND(ttys, db_show_all_ttys)
2058 {
2059 	struct tty *tp;
2060 	size_t isiz, osiz;
2061 	int i, j;
2062 
2063 	/* Make the output look like `pstat -t'. */
2064 	db_printf("PTR        ");
2065 #if defined(__LP64__)
2066 	db_printf("        ");
2067 #endif
2068 	db_printf("      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   "
2069 	    "COL  SESS  PGID STATE\n");
2070 
2071 	TAILQ_FOREACH(tp, &tty_list, t_list) {
2072 		isiz = tp->t_inq.ti_nblocks * TTYINQ_DATASIZE;
2073 		osiz = tp->t_outq.to_nblocks * TTYOUTQ_DATASIZE;
2074 
2075 		db_printf("%p %10s %5zu %4u %4u %4zu %5zu %4u %4zu %5u %5d %5d ",
2076 		    tp,
2077 		    tty_devname(tp),
2078 		    isiz,
2079 		    tp->t_inq.ti_linestart - tp->t_inq.ti_begin,
2080 		    tp->t_inq.ti_end - tp->t_inq.ti_linestart,
2081 		    isiz - tp->t_inlow,
2082 		    osiz,
2083 		    tp->t_outq.to_end - tp->t_outq.to_begin,
2084 		    osiz - tp->t_outlow,
2085 		    MIN(tp->t_column, 99999),
2086 		    tp->t_session ? tp->t_session->s_sid : 0,
2087 		    tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
2088 
2089 		/* Flag bits. */
2090 		for (i = j = 0; ttystates[i].flag; i++)
2091 			if (tp->t_flags & ttystates[i].flag) {
2092 				db_printf("%c", ttystates[i].val);
2093 				j++;
2094 			}
2095 		if (j == 0)
2096 			db_printf("-");
2097 		db_printf("\n");
2098 	}
2099 }
2100 #endif /* DDB */
2101