xref: /freebsd/sys/kern/tty.c (revision 00a5db46de56179184c0f000eaacad695e2b0859)
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 	/* Disallow access when the TTY belongs to a different prison. */
223 	if (dev->si_cred != NULL &&
224 	    dev->si_cred->cr_prison != td->td_ucred->cr_prison &&
225 	    priv_check(td, PRIV_TTY_PRISON)) {
226 		return (EPERM);
227 	}
228 
229 	tty_lock(tp);
230 	if (tty_gone(tp)) {
231 		/* Device is already gone. */
232 		tty_unlock(tp);
233 		return (ENXIO);
234 	}
235 
236 	/*
237 	 * Block when other processes are currently opening or closing
238 	 * the TTY.
239 	 */
240 	while (tp->t_flags & TF_OPENCLOSE) {
241 		error = tty_wait(tp, &tp->t_dcdwait);
242 		if (error != 0) {
243 			tty_unlock(tp);
244 			return (error);
245 		}
246 	}
247 	tp->t_flags |= TF_OPENCLOSE;
248 
249 	/*
250 	 * Make sure the "tty" and "cua" device cannot be opened at the
251 	 * same time.
252 	 */
253 	if (TTY_CALLOUT(tp, dev)) {
254 		if (tp->t_flags & TF_OPENED_IN) {
255 			error = EBUSY;
256 			goto done;
257 		}
258 	} else {
259 		if (tp->t_flags & TF_OPENED_OUT) {
260 			error = EBUSY;
261 			goto done;
262 		}
263 	}
264 
265 	if (tp->t_flags & TF_EXCLUDE && priv_check(td, PRIV_TTY_EXCLUSIVE)) {
266 		error = EBUSY;
267 		goto done;
268 	}
269 
270 	if (!tty_opened(tp)) {
271 		/* Set proper termios flags. */
272 		if (TTY_CALLOUT(tp, dev)) {
273 			tp->t_termios = tp->t_termios_init_out;
274 		} else {
275 			tp->t_termios = tp->t_termios_init_in;
276 		}
277 		ttydevsw_param(tp, &tp->t_termios);
278 
279 		ttydevsw_modem(tp, SER_DTR|SER_RTS, 0);
280 
281 		error = ttydevsw_open(tp);
282 		if (error != 0)
283 			goto done;
284 
285 		ttydisc_open(tp);
286 		tty_watermarks(tp);
287 	}
288 
289 	/* Wait for Carrier Detect. */
290 	if (!TTY_CALLOUT(tp, dev) && (oflags & O_NONBLOCK) == 0 &&
291 	    (tp->t_termios.c_cflag & CLOCAL) == 0) {
292 		while ((ttydevsw_modem(tp, 0, 0) & SER_DCD) == 0) {
293 			error = tty_wait(tp, &tp->t_dcdwait);
294 			if (error != 0)
295 				goto done;
296 		}
297 	}
298 
299 	if (dev == dev_console)
300 		tp->t_flags |= TF_OPENED_CONS;
301 	else if (TTY_CALLOUT(tp, dev))
302 		tp->t_flags |= TF_OPENED_OUT;
303 	else
304 		tp->t_flags |= TF_OPENED_IN;
305 
306 done:	tp->t_flags &= ~TF_OPENCLOSE;
307 	cv_broadcast(&tp->t_dcdwait);
308 	ttydev_leave(tp);
309 
310 	return (error);
311 }
312 
313 static int
314 ttydev_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
315 {
316 	struct tty *tp = dev->si_drv1;
317 
318 	tty_lock(tp);
319 
320 	/*
321 	 * Don't actually close the device if it is being used as the
322 	 * console.
323 	 */
324 	MPASS((tp->t_flags & TF_OPENED) != TF_OPENED);
325 	if (dev == dev_console)
326 		tp->t_flags &= ~TF_OPENED_CONS;
327 	else
328 		tp->t_flags &= ~(TF_OPENED_IN|TF_OPENED_OUT);
329 
330 	if (tp->t_flags & TF_OPENED) {
331 		tty_unlock(tp);
332 		return (0);
333 	}
334 
335 	/*
336 	 * This can only be called once. The callin and the callout
337 	 * devices cannot be opened at the same time.
338 	 */
339 	tp->t_flags &= ~(TF_EXCLUDE|TF_STOPPED);
340 
341 	/* Properly wake up threads that are stuck - revoke(). */
342 	tp->t_revokecnt++;
343 	tty_wakeup(tp, FREAD|FWRITE);
344 	cv_broadcast(&tp->t_bgwait);
345 
346 	ttydev_leave(tp);
347 
348 	return (0);
349 }
350 
351 static __inline int
352 tty_is_ctty(struct tty *tp, struct proc *p)
353 {
354 	tty_lock_assert(tp, MA_OWNED);
355 
356 	return (p->p_session == tp->t_session && p->p_flag & P_CONTROLT);
357 }
358 
359 static int
360 tty_wait_background(struct tty *tp, struct thread *td, int sig)
361 {
362 	struct proc *p = td->td_proc;
363 	struct pgrp *pg;
364 	int error;
365 
366 	MPASS(sig == SIGTTIN || sig == SIGTTOU);
367 	tty_lock_assert(tp, MA_OWNED);
368 
369 	for (;;) {
370 		PROC_LOCK(p);
371 		/*
372 		 * The process should only sleep, when:
373 		 * - This terminal is the controling terminal
374 		 * - Its process group is not the foreground process
375 		 *   group
376 		 * - The parent process isn't waiting for the child to
377 		 *   exit
378 		 * - the signal to send to the process isn't masked
379 		 */
380 		if (!tty_is_ctty(tp, p) || p->p_pgrp == tp->t_pgrp) {
381 			/* Allow the action to happen. */
382 			PROC_UNLOCK(p);
383 			return (0);
384 		}
385 
386 		if (SIGISMEMBER(p->p_sigacts->ps_sigignore, sig) ||
387 		    SIGISMEMBER(td->td_sigmask, sig)) {
388 			/* Only allow them in write()/ioctl(). */
389 			PROC_UNLOCK(p);
390 			return (sig == SIGTTOU ? 0 : EIO);
391 		}
392 
393 		pg = p->p_pgrp;
394 		if (p->p_flag & P_PPWAIT || pg->pg_jobc == 0) {
395 			/* Don't allow the action to happen. */
396 			PROC_UNLOCK(p);
397 			return (EIO);
398 		}
399 		PROC_UNLOCK(p);
400 
401 		/*
402 		 * Send the signal and sleep until we're the new
403 		 * foreground process group.
404 		 */
405 		PGRP_LOCK(pg);
406 		pgsignal(pg, sig, 1);
407 		PGRP_UNLOCK(pg);
408 
409 		error = tty_wait(tp, &tp->t_bgwait);
410 		if (error)
411 			return (error);
412 	}
413 }
414 
415 static int
416 ttydev_read(struct cdev *dev, struct uio *uio, int ioflag)
417 {
418 	struct tty *tp = dev->si_drv1;
419 	int error;
420 
421 	error = ttydev_enter(tp);
422 	if (error)
423 		goto done;
424 
425 	error = tty_wait_background(tp, curthread, SIGTTIN);
426 	if (error) {
427 		tty_unlock(tp);
428 		goto done;
429 	}
430 
431 	error = ttydisc_read(tp, uio, ioflag);
432 	tty_unlock(tp);
433 
434 	/*
435 	 * The read() call should not throw an error when the device is
436 	 * being destroyed. Silently convert it to an EOF.
437 	 */
438 done:	if (error == ENXIO)
439 		error = 0;
440 	return (error);
441 }
442 
443 static int
444 ttydev_write(struct cdev *dev, struct uio *uio, int ioflag)
445 {
446 	struct tty *tp = dev->si_drv1;
447 	int error;
448 
449 	error = ttydev_enter(tp);
450 	if (error)
451 		return (error);
452 
453 	if (tp->t_termios.c_lflag & TOSTOP) {
454 		error = tty_wait_background(tp, curthread, SIGTTOU);
455 		if (error)
456 			goto done;
457 	}
458 
459 	if (ioflag & IO_NDELAY && tp->t_flags & TF_BUSY_OUT) {
460 		/* Allow non-blocking writes to bypass serialization. */
461 		error = ttydisc_write(tp, uio, ioflag);
462 	} else {
463 		/* Serialize write() calls. */
464 		while (tp->t_flags & TF_BUSY_OUT) {
465 			error = tty_wait(tp, &tp->t_bgwait);
466 			if (error)
467 				goto done;
468 		}
469 
470  		tp->t_flags |= TF_BUSY_OUT;
471 		error = ttydisc_write(tp, uio, ioflag);
472  		tp->t_flags &= ~TF_BUSY_OUT;
473 		cv_broadcast(&tp->t_bgwait);
474 	}
475 
476 done:	tty_unlock(tp);
477 	return (error);
478 }
479 
480 static int
481 ttydev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
482     struct thread *td)
483 {
484 	struct tty *tp = dev->si_drv1;
485 	int error;
486 
487 	error = ttydev_enter(tp);
488 	if (error)
489 		return (error);
490 
491 	switch (cmd) {
492 	case TIOCCBRK:
493 	case TIOCCONS:
494 	case TIOCDRAIN:
495 	case TIOCEXCL:
496 	case TIOCFLUSH:
497 	case TIOCNXCL:
498 	case TIOCSBRK:
499 	case TIOCSCTTY:
500 	case TIOCSETA:
501 	case TIOCSETAF:
502 	case TIOCSETAW:
503 	case TIOCSPGRP:
504 	case TIOCSTART:
505 	case TIOCSTAT:
506 	case TIOCSTOP:
507 	case TIOCSWINSZ:
508 #if 0
509 	case TIOCSDRAINWAIT:
510 	case TIOCSETD:
511 	case TIOCSTI:
512 #endif
513 #ifdef COMPAT_43TTY
514 	case  TIOCLBIC:
515 	case  TIOCLBIS:
516 	case  TIOCLSET:
517 	case  TIOCSETC:
518 	case OTIOCSETD:
519 	case  TIOCSETN:
520 	case  TIOCSETP:
521 	case  TIOCSLTC:
522 #endif /* COMPAT_43TTY */
523 		/*
524 		 * If the ioctl() causes the TTY to be modified, let it
525 		 * wait in the background.
526 		 */
527 		error = tty_wait_background(tp, curthread, SIGTTOU);
528 		if (error)
529 			goto done;
530 	}
531 
532 	error = tty_ioctl(tp, cmd, data, td);
533 done:	tty_unlock(tp);
534 
535 	return (error);
536 }
537 
538 static int
539 ttydev_poll(struct cdev *dev, int events, struct thread *td)
540 {
541 	struct tty *tp = dev->si_drv1;
542 	int error, revents = 0;
543 
544 	error = ttydev_enter(tp);
545 	if (error) {
546 		/* Don't return the error here, but the event mask. */
547 		return (events &
548 		    (POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM));
549 	}
550 
551 	if (events & (POLLIN|POLLRDNORM)) {
552 		/* See if we can read something. */
553 		if (ttydisc_read_poll(tp) > 0)
554 			revents |= events & (POLLIN|POLLRDNORM);
555 	}
556 	if (events & (POLLOUT|POLLWRNORM)) {
557 		/* See if we can write something. */
558 		if (ttydisc_write_poll(tp) > 0)
559 			revents |= events & (POLLOUT|POLLWRNORM);
560 	}
561 	if (tp->t_flags & TF_ZOMBIE)
562 		/* Hangup flag on zombie state. */
563 		revents |= events & POLLHUP;
564 
565 	if (revents == 0) {
566 		if (events & (POLLIN|POLLRDNORM))
567 			selrecord(td, &tp->t_inpoll);
568 		if (events & (POLLOUT|POLLWRNORM))
569 			selrecord(td, &tp->t_outpoll);
570 	}
571 
572 	tty_unlock(tp);
573 
574 	return (revents);
575 }
576 
577 static int
578 ttydev_mmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr, int nprot)
579 {
580 	struct tty *tp = dev->si_drv1;
581 	int error;
582 
583 	/* Handle mmap() through the driver. */
584 
585 	error = ttydev_enter(tp);
586 	if (error)
587 		return (-1);
588 	error = ttydevsw_mmap(tp, offset, paddr, nprot);
589 	tty_unlock(tp);
590 
591 	return (error);
592 }
593 
594 /*
595  * kqueue support.
596  */
597 
598 static void
599 tty_kqops_read_detach(struct knote *kn)
600 {
601 	struct tty *tp = kn->kn_hook;
602 
603 	knlist_remove(&tp->t_inpoll.si_note, kn, 0);
604 }
605 
606 static int
607 tty_kqops_read_event(struct knote *kn, long hint)
608 {
609 	struct tty *tp = kn->kn_hook;
610 
611 	tty_lock_assert(tp, MA_OWNED);
612 
613 	if (tty_gone(tp) || tp->t_flags & TF_ZOMBIE) {
614 		kn->kn_flags |= EV_EOF;
615 		return (1);
616 	} else {
617 		kn->kn_data = ttydisc_read_poll(tp);
618 		return (kn->kn_data > 0);
619 	}
620 }
621 
622 static void
623 tty_kqops_write_detach(struct knote *kn)
624 {
625 	struct tty *tp = kn->kn_hook;
626 
627 	knlist_remove(&tp->t_outpoll.si_note, kn, 0);
628 }
629 
630 static int
631 tty_kqops_write_event(struct knote *kn, long hint)
632 {
633 	struct tty *tp = kn->kn_hook;
634 
635 	tty_lock_assert(tp, MA_OWNED);
636 
637 	if (tty_gone(tp)) {
638 		kn->kn_flags |= EV_EOF;
639 		return (1);
640 	} else {
641 		kn->kn_data = ttydisc_write_poll(tp);
642 		return (kn->kn_data > 0);
643 	}
644 }
645 
646 static struct filterops tty_kqops_read =
647     { 1, NULL, tty_kqops_read_detach, tty_kqops_read_event };
648 static struct filterops tty_kqops_write =
649     { 1, NULL, tty_kqops_write_detach, tty_kqops_write_event };
650 
651 static int
652 ttydev_kqfilter(struct cdev *dev, struct knote *kn)
653 {
654 	struct tty *tp = dev->si_drv1;
655 	int error;
656 
657 	error = ttydev_enter(tp);
658 	if (error)
659 		return (error);
660 
661 	switch (kn->kn_filter) {
662 	case EVFILT_READ:
663 		kn->kn_hook = tp;
664 		kn->kn_fop = &tty_kqops_read;
665 		knlist_add(&tp->t_inpoll.si_note, kn, 1);
666 		break;
667 	case EVFILT_WRITE:
668 		kn->kn_hook = tp;
669 		kn->kn_fop = &tty_kqops_write;
670 		knlist_add(&tp->t_outpoll.si_note, kn, 1);
671 		break;
672 	default:
673 		error = EINVAL;
674 		break;
675 	}
676 
677 	tty_unlock(tp);
678 	return (error);
679 }
680 
681 static struct cdevsw ttydev_cdevsw = {
682 	.d_version	= D_VERSION,
683 	.d_open		= ttydev_open,
684 	.d_close	= ttydev_close,
685 	.d_read		= ttydev_read,
686 	.d_write	= ttydev_write,
687 	.d_ioctl	= ttydev_ioctl,
688 	.d_kqfilter	= ttydev_kqfilter,
689 	.d_poll		= ttydev_poll,
690 	.d_mmap		= ttydev_mmap,
691 	.d_name		= "ttydev",
692 	.d_flags	= D_TTY,
693 };
694 
695 /*
696  * Init/lock-state devices
697  */
698 
699 static int
700 ttyil_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
701 {
702 	struct tty *tp = dev->si_drv1;
703 	int error = 0;
704 
705 	tty_lock(tp);
706 	if (tty_gone(tp))
707 		error = ENODEV;
708 	tty_unlock(tp);
709 
710 	return (error);
711 }
712 
713 static int
714 ttyil_close(struct cdev *dev, int flag, int mode, struct thread *td)
715 {
716 	return (0);
717 }
718 
719 static int
720 ttyil_rdwr(struct cdev *dev, struct uio *uio, int ioflag)
721 {
722 	return (ENODEV);
723 }
724 
725 static int
726 ttyil_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
727     struct thread *td)
728 {
729 	struct tty *tp = dev->si_drv1;
730 	int error = 0;
731 
732 	tty_lock(tp);
733 	if (tty_gone(tp)) {
734 		error = ENODEV;
735 		goto done;
736 	}
737 
738 	switch (cmd) {
739 	case TIOCGETA:
740 		/* Obtain terminal flags through tcgetattr(). */
741 		*(struct termios*)data = *(struct termios*)dev->si_drv2;
742 		break;
743 	case TIOCSETA:
744 		/* Set terminal flags through tcsetattr(). */
745 		error = priv_check(td, PRIV_TTY_SETA);
746 		if (error)
747 			break;
748 		*(struct termios*)dev->si_drv2 = *(struct termios*)data;
749 		break;
750 	case TIOCGETD:
751 		*(int *)data = TTYDISC;
752 		break;
753 	case TIOCGWINSZ:
754 		bzero(data, sizeof(struct winsize));
755 		break;
756 	default:
757 		error = ENOTTY;
758 	}
759 
760 done:	tty_unlock(tp);
761 	return (error);
762 }
763 
764 static struct cdevsw ttyil_cdevsw = {
765 	.d_version	= D_VERSION,
766 	.d_open		= ttyil_open,
767 	.d_close	= ttyil_close,
768 	.d_read		= ttyil_rdwr,
769 	.d_write	= ttyil_rdwr,
770 	.d_ioctl	= ttyil_ioctl,
771 	.d_name		= "ttyil",
772 	.d_flags	= D_TTY,
773 };
774 
775 static void
776 tty_init_termios(struct tty *tp)
777 {
778 	struct termios *t = &tp->t_termios_init_in;
779 
780 	t->c_cflag = TTYDEF_CFLAG;
781 	t->c_iflag = TTYDEF_IFLAG;
782 	t->c_lflag = TTYDEF_LFLAG;
783 	t->c_oflag = TTYDEF_OFLAG;
784 	t->c_ispeed = TTYDEF_SPEED;
785 	t->c_ospeed = TTYDEF_SPEED;
786 	memcpy(&t->c_cc, ttydefchars, sizeof ttydefchars);
787 
788 	tp->t_termios_init_out = *t;
789 }
790 
791 void
792 tty_init_console(struct tty *tp, speed_t s)
793 {
794 	struct termios *ti = &tp->t_termios_init_in;
795 	struct termios *to = &tp->t_termios_init_out;
796 
797 	if (s != 0) {
798 		ti->c_ispeed = ti->c_ospeed = s;
799 		to->c_ispeed = to->c_ospeed = s;
800 	}
801 
802 	ti->c_cflag |= CLOCAL;
803 	to->c_cflag |= CLOCAL;
804 }
805 
806 /*
807  * Standard device routine implementations, mostly meant for
808  * pseudo-terminal device drivers. When a driver creates a new terminal
809  * device class, missing routines are patched.
810  */
811 
812 static int
813 ttydevsw_defopen(struct tty *tp)
814 {
815 
816 	return (0);
817 }
818 
819 static void
820 ttydevsw_defclose(struct tty *tp)
821 {
822 }
823 
824 static void
825 ttydevsw_defoutwakeup(struct tty *tp)
826 {
827 
828 	panic("Terminal device has output, while not implemented");
829 }
830 
831 static void
832 ttydevsw_definwakeup(struct tty *tp)
833 {
834 }
835 
836 static int
837 ttydevsw_defioctl(struct tty *tp, u_long cmd, caddr_t data, struct thread *td)
838 {
839 
840 	return (ENOIOCTL);
841 }
842 
843 static int
844 ttydevsw_defparam(struct tty *tp, struct termios *t)
845 {
846 
847 	/* Use a fake baud rate, we're not a real device. */
848 	t->c_ispeed = t->c_ospeed = TTYDEF_SPEED;
849 
850 	return (0);
851 }
852 
853 static int
854 ttydevsw_defmodem(struct tty *tp, int sigon, int sigoff)
855 {
856 
857 	/* Simulate a carrier to make the TTY layer happy. */
858 	return (SER_DCD);
859 }
860 
861 static int
862 ttydevsw_defmmap(struct tty *tp, vm_offset_t offset, vm_paddr_t *paddr,
863     int nprot)
864 {
865 
866 	return (-1);
867 }
868 
869 static void
870 ttydevsw_defpktnotify(struct tty *tp, char event)
871 {
872 }
873 
874 static void
875 ttydevsw_deffree(void *softc)
876 {
877 
878 	panic("Terminal device freed without a free-handler");
879 }
880 
881 /*
882  * TTY allocation and deallocation. TTY devices can be deallocated when
883  * the driver doesn't use it anymore, when the TTY isn't a session's
884  * controlling TTY and when the device node isn't opened through devfs.
885  */
886 
887 struct tty *
888 tty_alloc(struct ttydevsw *tsw, void *sc, struct mtx *mutex)
889 {
890 	struct tty *tp;
891 
892 	/* Make sure the driver defines all routines. */
893 #define PATCH_FUNC(x) do {				\
894 	if (tsw->tsw_ ## x == NULL)			\
895 		tsw->tsw_ ## x = ttydevsw_def ## x;	\
896 } while (0)
897 	PATCH_FUNC(open);
898 	PATCH_FUNC(close);
899 	PATCH_FUNC(outwakeup);
900 	PATCH_FUNC(inwakeup);
901 	PATCH_FUNC(ioctl);
902 	PATCH_FUNC(param);
903 	PATCH_FUNC(modem);
904 	PATCH_FUNC(mmap);
905 	PATCH_FUNC(pktnotify);
906 	PATCH_FUNC(free);
907 #undef PATCH_FUNC
908 
909 	tp = malloc(sizeof(struct tty), M_TTY, M_WAITOK|M_ZERO);
910 	tp->t_devsw = tsw;
911 	tp->t_devswsoftc = sc;
912 	tp->t_flags = tsw->tsw_flags;
913 
914 	tty_init_termios(tp);
915 
916 	cv_init(&tp->t_inwait, "ttyin");
917 	cv_init(&tp->t_outwait, "ttyout");
918 	cv_init(&tp->t_bgwait, "ttybg");
919 	cv_init(&tp->t_dcdwait, "ttydcd");
920 
921 	/* Allow drivers to use a custom mutex to lock the TTY. */
922 	if (mutex != NULL) {
923 		tp->t_mtx = mutex;
924 	} else {
925 		tp->t_mtx = &tp->t_mtxobj;
926 		mtx_init(&tp->t_mtxobj, "ttymtx", NULL, MTX_DEF);
927 	}
928 
929 	knlist_init(&tp->t_inpoll.si_note, tp->t_mtx, NULL, NULL, NULL);
930 	knlist_init(&tp->t_outpoll.si_note, tp->t_mtx, NULL, NULL, NULL);
931 
932 	sx_xlock(&tty_list_sx);
933 	TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
934 	tty_list_count++;
935 	sx_xunlock(&tty_list_sx);
936 
937 	return (tp);
938 }
939 
940 static void
941 tty_dealloc(void *arg)
942 {
943 	struct tty *tp = arg;
944 
945 	sx_xlock(&tty_list_sx);
946 	TAILQ_REMOVE(&tty_list, tp, t_list);
947 	tty_list_count--;
948 	sx_xunlock(&tty_list_sx);
949 
950 	/* Make sure we haven't leaked buffers. */
951 	MPASS(ttyinq_getsize(&tp->t_inq) == 0);
952 	MPASS(ttyoutq_getsize(&tp->t_outq) == 0);
953 
954 	knlist_destroy(&tp->t_inpoll.si_note);
955 	knlist_destroy(&tp->t_outpoll.si_note);
956 
957 	cv_destroy(&tp->t_inwait);
958 	cv_destroy(&tp->t_outwait);
959 	cv_destroy(&tp->t_bgwait);
960 	cv_destroy(&tp->t_dcdwait);
961 
962 	if (tp->t_mtx == &tp->t_mtxobj)
963 		mtx_destroy(&tp->t_mtxobj);
964 	ttydevsw_free(tp);
965 	free(tp, M_TTY);
966 }
967 
968 static void
969 tty_rel_free(struct tty *tp)
970 {
971 	struct cdev *dev;
972 
973 	tty_lock_assert(tp, MA_OWNED);
974 
975 #define	TF_ACTIVITY	(TF_GONE|TF_OPENED|TF_HOOK|TF_OPENCLOSE)
976 	if (tp->t_sessioncnt != 0 || (tp->t_flags & TF_ACTIVITY) != TF_GONE) {
977 		/* TTY is still in use. */
978 		tty_unlock(tp);
979 		return;
980 	}
981 
982 	/* TTY can be deallocated. */
983 	dev = tp->t_dev;
984 	tp->t_dev = NULL;
985 	tty_unlock(tp);
986 
987 	destroy_dev_sched_cb(dev, tty_dealloc, tp);
988 }
989 
990 void
991 tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
992 {
993 	MPASS(tp->t_sessioncnt > 0);
994 	tty_lock_assert(tp, MA_OWNED);
995 
996 	if (tp->t_pgrp == pg)
997 		tp->t_pgrp = NULL;
998 
999 	tty_unlock(tp);
1000 }
1001 
1002 void
1003 tty_rel_sess(struct tty *tp, struct session *sess)
1004 {
1005 	MPASS(tp->t_sessioncnt > 0);
1006 
1007 	/* Current session has left. */
1008 	if (tp->t_session == sess) {
1009 		tp->t_session = NULL;
1010 		MPASS(tp->t_pgrp == NULL);
1011 	}
1012 	tp->t_sessioncnt--;
1013 	tty_rel_free(tp);
1014 }
1015 
1016 void
1017 tty_rel_gone(struct tty *tp)
1018 {
1019 	MPASS(!tty_gone(tp));
1020 
1021 	/* Simulate carrier removal. */
1022 	ttydisc_modem(tp, 0);
1023 
1024 	/* Wake up all blocked threads. */
1025 	tty_wakeup(tp, FREAD|FWRITE);
1026 	cv_broadcast(&tp->t_bgwait);
1027 	cv_broadcast(&tp->t_dcdwait);
1028 
1029 	tp->t_flags |= TF_GONE;
1030 	tty_rel_free(tp);
1031 }
1032 
1033 /*
1034  * Exposing information about current TTY's through sysctl
1035  */
1036 
1037 static void
1038 tty_to_xtty(struct tty *tp, struct xtty *xt)
1039 {
1040 	tty_lock_assert(tp, MA_OWNED);
1041 
1042 	xt->xt_size = sizeof(struct xtty);
1043 	xt->xt_insize = ttyinq_getsize(&tp->t_inq);
1044 	xt->xt_incc = ttyinq_bytescanonicalized(&tp->t_inq);
1045 	xt->xt_inlc = ttyinq_bytesline(&tp->t_inq);
1046 	xt->xt_inlow = tp->t_inlow;
1047 	xt->xt_outsize = ttyoutq_getsize(&tp->t_outq);
1048 	xt->xt_outcc = ttyoutq_bytesused(&tp->t_outq);
1049 	xt->xt_outlow = tp->t_outlow;
1050 	xt->xt_column = tp->t_column;
1051 	xt->xt_pgid = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
1052 	xt->xt_sid = tp->t_session ? tp->t_session->s_sid : 0;
1053 	xt->xt_flags = tp->t_flags;
1054 	xt->xt_dev = tp->t_dev ? dev2udev(tp->t_dev) : NODEV;
1055 }
1056 
1057 static int
1058 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
1059 {
1060 	unsigned long lsize;
1061 	struct xtty *xtlist, *xt;
1062 	struct tty *tp;
1063 	int error;
1064 
1065 	sx_slock(&tty_list_sx);
1066 	lsize = tty_list_count * sizeof(struct xtty);
1067 	if (lsize == 0) {
1068 		sx_sunlock(&tty_list_sx);
1069 		return (0);
1070 	}
1071 
1072 	xtlist = xt = malloc(lsize, M_TTY, M_WAITOK);
1073 
1074 	TAILQ_FOREACH(tp, &tty_list, t_list) {
1075 		tty_lock(tp);
1076 		tty_to_xtty(tp, xt);
1077 		tty_unlock(tp);
1078 		xt++;
1079 	}
1080 	sx_sunlock(&tty_list_sx);
1081 
1082 	error = SYSCTL_OUT(req, xtlist, lsize);
1083 	free(xtlist, M_TTY);
1084 	return (error);
1085 }
1086 
1087 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
1088 	0, 0, sysctl_kern_ttys, "S,xtty", "List of TTYs");
1089 
1090 /*
1091  * Device node creation. Device has been set up, now we can expose it to
1092  * the user.
1093  */
1094 
1095 void
1096 tty_makedev(struct tty *tp, struct ucred *cred, const char *fmt, ...)
1097 {
1098 	va_list ap;
1099 	struct cdev *dev;
1100 	const char *prefix = "tty";
1101 	char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
1102 	uid_t uid;
1103 	gid_t gid;
1104 	mode_t mode;
1105 
1106 	/* Remove "tty" prefix from devices like PTY's. */
1107 	if (tp->t_flags & TF_NOPREFIX)
1108 		prefix = "";
1109 
1110 	va_start(ap, fmt);
1111 	vsnrprintf(name, sizeof name, 32, fmt, ap);
1112 	va_end(ap);
1113 
1114 	if (cred == NULL) {
1115 		/* System device. */
1116 		uid = UID_ROOT;
1117 		gid = GID_WHEEL;
1118 		mode = S_IRUSR|S_IWUSR;
1119 	} else {
1120 		/* User device. */
1121 		uid = cred->cr_ruid;
1122 		gid = GID_TTY;
1123 		mode = S_IRUSR|S_IWUSR|S_IWGRP;
1124 	}
1125 
1126 	/* Master call-in device. */
1127 	dev = make_dev_cred(&ttydev_cdevsw, 0, cred,
1128 	    uid, gid, mode, "%s%s", prefix, name);
1129 	dev->si_drv1 = tp;
1130 	tp->t_dev = dev;
1131 
1132 	/* Slave call-in devices. */
1133 	if (tp->t_flags & TF_INITLOCK) {
1134 		dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1135 		    uid, gid, mode, "%s%s.init", prefix, name);
1136 		dev_depends(tp->t_dev, dev);
1137 		dev->si_drv1 = tp;
1138 		dev->si_drv2 = &tp->t_termios_init_in;
1139 
1140 		dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1141 		    uid, gid, mode, "%s%s.lock", prefix, name);
1142 		dev_depends(tp->t_dev, dev);
1143 		dev->si_drv1 = tp;
1144 		dev->si_drv2 = &tp->t_termios_lock_in;
1145 	}
1146 
1147 	/* Call-out devices. */
1148 	if (tp->t_flags & TF_CALLOUT) {
1149 		dev = make_dev_cred(&ttydev_cdevsw, 0, cred,
1150 		    UID_UUCP, GID_DIALER, 0660, "cua%s", name);
1151 		dev_depends(tp->t_dev, dev);
1152 		dev->si_drv1 = tp;
1153 
1154 		/* Slave call-out devices. */
1155 		if (tp->t_flags & TF_INITLOCK) {
1156 			dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1157 			    UID_UUCP, GID_DIALER, 0660, "cua%s.init", name);
1158 			dev_depends(tp->t_dev, dev);
1159 			dev->si_drv1 = tp;
1160 			dev->si_drv2 = &tp->t_termios_init_out;
1161 
1162 			dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1163 			    UID_UUCP, GID_DIALER, 0660, "cua%s.lock", name);
1164 			dev_depends(tp->t_dev, dev);
1165 			dev->si_drv1 = tp;
1166 			dev->si_drv2 = &tp->t_termios_lock_out;
1167 		}
1168 	}
1169 }
1170 
1171 /*
1172  * Signalling processes.
1173  */
1174 
1175 void
1176 tty_signal_sessleader(struct tty *tp, int sig)
1177 {
1178 	struct proc *p;
1179 
1180 	tty_lock_assert(tp, MA_OWNED);
1181 	MPASS(sig >= 1 && sig < NSIG);
1182 
1183 	/* Make signals start output again. */
1184 	tp->t_flags &= ~TF_STOPPED;
1185 
1186 	if (tp->t_session != NULL && tp->t_session->s_leader != NULL) {
1187 		p = tp->t_session->s_leader;
1188 		PROC_LOCK(p);
1189 		psignal(p, sig);
1190 		PROC_UNLOCK(p);
1191 	}
1192 }
1193 
1194 void
1195 tty_signal_pgrp(struct tty *tp, int sig)
1196 {
1197 	tty_lock_assert(tp, MA_OWNED);
1198 	MPASS(sig >= 1 && sig < NSIG);
1199 
1200 	/* Make signals start output again. */
1201 	tp->t_flags &= ~TF_STOPPED;
1202 
1203 	if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
1204 		tty_info(tp);
1205 	if (tp->t_pgrp != NULL) {
1206 		PGRP_LOCK(tp->t_pgrp);
1207 		pgsignal(tp->t_pgrp, sig, 1);
1208 		PGRP_UNLOCK(tp->t_pgrp);
1209 	}
1210 }
1211 
1212 void
1213 tty_wakeup(struct tty *tp, int flags)
1214 {
1215 	if (tp->t_flags & TF_ASYNC && tp->t_sigio != NULL)
1216 		pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
1217 
1218 	if (flags & FWRITE) {
1219 		cv_broadcast(&tp->t_outwait);
1220 		selwakeup(&tp->t_outpoll);
1221 		KNOTE_LOCKED(&tp->t_outpoll.si_note, 0);
1222 	}
1223 	if (flags & FREAD) {
1224 		cv_broadcast(&tp->t_inwait);
1225 		selwakeup(&tp->t_inpoll);
1226 		KNOTE_LOCKED(&tp->t_inpoll.si_note, 0);
1227 	}
1228 }
1229 
1230 int
1231 tty_wait(struct tty *tp, struct cv *cv)
1232 {
1233 	int error;
1234 	int revokecnt = tp->t_revokecnt;
1235 
1236 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1237 	MPASS(!tty_gone(tp));
1238 
1239 	error = cv_wait_sig(cv, tp->t_mtx);
1240 
1241 	/* Restart the system call when we may have been revoked. */
1242 	if (tp->t_revokecnt != revokecnt)
1243 		return (ERESTART);
1244 
1245 	/* Bail out when the device slipped away. */
1246 	if (tty_gone(tp))
1247 		return (ENXIO);
1248 
1249 	return (error);
1250 }
1251 
1252 int
1253 tty_timedwait(struct tty *tp, struct cv *cv, int hz)
1254 {
1255 	int error;
1256 	int revokecnt = tp->t_revokecnt;
1257 
1258 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1259 	MPASS(!tty_gone(tp));
1260 
1261 	error = cv_timedwait_sig(cv, tp->t_mtx, hz);
1262 
1263 	/* Restart the system call when we may have been revoked. */
1264 	if (tp->t_revokecnt != revokecnt)
1265 		return (ERESTART);
1266 
1267 	/* Bail out when the device slipped away. */
1268 	if (tty_gone(tp))
1269 		return (ENXIO);
1270 
1271 	return (error);
1272 }
1273 
1274 void
1275 tty_flush(struct tty *tp, int flags)
1276 {
1277 	if (flags & FWRITE) {
1278 		tp->t_flags &= ~TF_HIWAT_OUT;
1279 		ttyoutq_flush(&tp->t_outq);
1280 		tty_wakeup(tp, FWRITE);
1281 		ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
1282 	}
1283 	if (flags & FREAD) {
1284 		tty_hiwat_in_unblock(tp);
1285 		ttyinq_flush(&tp->t_inq);
1286 		ttydevsw_inwakeup(tp);
1287 		ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
1288 	}
1289 }
1290 
1291 static int
1292 tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, struct thread *td)
1293 {
1294 	int error;
1295 
1296 	switch (cmd) {
1297 	/*
1298 	 * Modem commands.
1299 	 * The SER_* and TIOCM_* flags are the same, but one bit
1300 	 * shifted. I don't know why.
1301 	 */
1302 	case TIOCSDTR:
1303 		ttydevsw_modem(tp, SER_DTR, 0);
1304 		return (0);
1305 	case TIOCCDTR:
1306 		ttydevsw_modem(tp, 0, SER_DTR);
1307 		return (0);
1308 	case TIOCMSET: {
1309 		int bits = *(int *)data;
1310 		ttydevsw_modem(tp,
1311 		    (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1,
1312 		    ((~bits) & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1313 		return (0);
1314 	}
1315 	case TIOCMBIS: {
1316 		int bits = *(int *)data;
1317 		ttydevsw_modem(tp, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1, 0);
1318 		return (0);
1319 	}
1320 	case TIOCMBIC: {
1321 		int bits = *(int *)data;
1322 		ttydevsw_modem(tp, 0, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1323 		return (0);
1324 	}
1325 	case TIOCMGET:
1326 		*(int *)data = TIOCM_LE + (ttydevsw_modem(tp, 0, 0) << 1);
1327 		return (0);
1328 
1329 	case FIOASYNC:
1330 		if (*(int *)data)
1331 			tp->t_flags |= TF_ASYNC;
1332 		else
1333 			tp->t_flags &= ~TF_ASYNC;
1334 		return (0);
1335 	case FIONBIO:
1336 		/* This device supports non-blocking operation. */
1337 		return (0);
1338 	case FIONREAD:
1339 		*(int *)data = ttyinq_bytescanonicalized(&tp->t_inq);
1340 		return (0);
1341 	case FIOSETOWN:
1342 		if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1343 			/* Not allowed to set ownership. */
1344 			return (ENOTTY);
1345 
1346 		/* Temporarily unlock the TTY to set ownership. */
1347 		tty_unlock(tp);
1348 		error = fsetown(*(int *)data, &tp->t_sigio);
1349 		tty_lock(tp);
1350 		return (error);
1351 	case FIOGETOWN:
1352 		if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1353 			/* Not allowed to set ownership. */
1354 			return (ENOTTY);
1355 
1356 		/* Get ownership. */
1357 		*(int *)data = fgetown(&tp->t_sigio);
1358 		return (0);
1359 	case TIOCGETA:
1360 		/* Obtain terminal flags through tcgetattr(). */
1361 		*(struct termios*)data = tp->t_termios;
1362 		return (0);
1363 	case TIOCSETA:
1364 	case TIOCSETAW:
1365 	case TIOCSETAF: {
1366 		struct termios *t = data;
1367 
1368 		/*
1369 		 * Who makes up these funny rules? According to POSIX,
1370 		 * input baud rate is set equal to the output baud rate
1371 		 * when zero.
1372 		 */
1373 		if (t->c_ispeed == 0)
1374 			t->c_ispeed = t->c_ospeed;
1375 
1376 		/* Discard any unsupported bits. */
1377 		t->c_iflag &= TTYSUP_IFLAG;
1378 		t->c_oflag &= TTYSUP_OFLAG;
1379 		t->c_lflag &= TTYSUP_LFLAG;
1380 		t->c_cflag &= TTYSUP_CFLAG;
1381 
1382 		/* Set terminal flags through tcsetattr(). */
1383 		if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
1384 			error = tty_drain(tp);
1385 			if (error)
1386 				return (error);
1387 			if (cmd == TIOCSETAF)
1388 				tty_flush(tp, FREAD);
1389 		}
1390 
1391 		/*
1392 		 * Only call param() when the flags really change.
1393 		 */
1394 		if ((t->c_cflag & CIGNORE) == 0 &&
1395 		    (tp->t_termios.c_cflag != t->c_cflag ||
1396 		    tp->t_termios.c_ispeed != t->c_ispeed ||
1397 		    tp->t_termios.c_ospeed != t->c_ospeed)) {
1398 			error = ttydevsw_param(tp, t);
1399 			if (error)
1400 				return (error);
1401 
1402 			/* XXX: CLOCAL? */
1403 
1404 			tp->t_termios.c_cflag = t->c_cflag & ~CIGNORE;
1405 			tp->t_termios.c_ispeed = t->c_ispeed;
1406 			tp->t_termios.c_ospeed = t->c_ospeed;
1407 
1408 			/* Baud rate has changed - update watermarks. */
1409 			tty_watermarks(tp);
1410 		}
1411 
1412 		/* Copy new non-device driver parameters. */
1413 		tp->t_termios.c_iflag = t->c_iflag;
1414 		tp->t_termios.c_oflag = t->c_oflag;
1415 		tp->t_termios.c_lflag = t->c_lflag;
1416 		memcpy(&tp->t_termios.c_cc, t->c_cc, sizeof t->c_cc);
1417 
1418 		ttydisc_optimize(tp);
1419 
1420 		if ((t->c_lflag & ICANON) == 0) {
1421 			/*
1422 			 * When in non-canonical mode, wake up all
1423 			 * readers. Canonicalize any partial input. VMIN
1424 			 * and VTIME could also be adjusted.
1425 			 */
1426 			ttyinq_canonicalize(&tp->t_inq);
1427 			tty_wakeup(tp, FREAD);
1428 		}
1429 
1430 		/*
1431 		 * For packet mode: notify the PTY consumer that VSTOP
1432 		 * and VSTART may have been changed.
1433 		 */
1434 		if (tp->t_termios.c_iflag & IXON &&
1435 		    tp->t_termios.c_cc[VSTOP] == CTRL('S') &&
1436 		    tp->t_termios.c_cc[VSTART] == CTRL('Q'))
1437 			ttydevsw_pktnotify(tp, TIOCPKT_DOSTOP);
1438 		else
1439 			ttydevsw_pktnotify(tp, TIOCPKT_NOSTOP);
1440 		return (0);
1441 	}
1442 	case TIOCGETD:
1443 		/* For compatibility - we only support TTYDISC. */
1444 		*(int *)data = TTYDISC;
1445 		return (0);
1446 	case TIOCGPGRP:
1447 		if (!tty_is_ctty(tp, td->td_proc))
1448 			return (ENOTTY);
1449 
1450 		if (tp->t_pgrp != NULL)
1451 			*(int *)data = tp->t_pgrp->pg_id;
1452 		else
1453 			*(int *)data = NO_PID;
1454 		return (0);
1455 	case TIOCGSID:
1456 		if (!tty_is_ctty(tp, td->td_proc))
1457 			return (ENOTTY);
1458 
1459 		MPASS(tp->t_session);
1460 		*(int *)data = tp->t_session->s_sid;
1461 		return (0);
1462 	case TIOCSCTTY: {
1463 		struct proc *p = td->td_proc;
1464 
1465 		/* XXX: This looks awful. */
1466 		tty_unlock(tp);
1467 		sx_xlock(&proctree_lock);
1468 		tty_lock(tp);
1469 
1470 		if (!SESS_LEADER(p)) {
1471 			/* Only the session leader may do this. */
1472 			sx_xunlock(&proctree_lock);
1473 			return (EPERM);
1474 		}
1475 
1476 		if (tp->t_session != NULL && tp->t_session == p->p_session) {
1477 			/* This is already our controlling TTY. */
1478 			sx_xunlock(&proctree_lock);
1479 			return (0);
1480 		}
1481 
1482 		if (p->p_session->s_ttyvp != NULL ||
1483 		    (tp->t_session != NULL && tp->t_session->s_ttyvp != NULL)) {
1484 			/*
1485 			 * There is already a relation between a TTY and
1486 			 * a session, or the caller is not the session
1487 			 * leader.
1488 			 *
1489 			 * Allow the TTY to be stolen when the vnode is
1490 			 * NULL, but the reference to the TTY is still
1491 			 * active.
1492 			 */
1493 			sx_xunlock(&proctree_lock);
1494 			return (EPERM);
1495 		}
1496 
1497 		/* Connect the session to the TTY. */
1498 		tp->t_session = p->p_session;
1499 		tp->t_session->s_ttyp = tp;
1500 		tp->t_sessioncnt++;
1501 		sx_xunlock(&proctree_lock);
1502 
1503 		/* Assign foreground process group. */
1504 		tp->t_pgrp = p->p_pgrp;
1505 		PROC_LOCK(p);
1506 		p->p_flag |= P_CONTROLT;
1507 		PROC_UNLOCK(p);
1508 
1509 		return (0);
1510 	}
1511 	case TIOCSPGRP: {
1512 		struct pgrp *pg;
1513 
1514 		/*
1515 		 * XXX: Temporarily unlock the TTY to locate the process
1516 		 * group. This code would be lot nicer if we would ever
1517 		 * decompose proctree_lock.
1518 		 */
1519 		tty_unlock(tp);
1520 		sx_slock(&proctree_lock);
1521 		pg = pgfind(*(int *)data);
1522 		if (pg != NULL)
1523 			PGRP_UNLOCK(pg);
1524 		if (pg == NULL || pg->pg_session != td->td_proc->p_session) {
1525 			sx_sunlock(&proctree_lock);
1526 			tty_lock(tp);
1527 			return (EPERM);
1528 		}
1529 		tty_lock(tp);
1530 
1531 		/*
1532 		 * Determine if this TTY is the controlling TTY after
1533 		 * relocking the TTY.
1534 		 */
1535 		if (!tty_is_ctty(tp, td->td_proc)) {
1536 			sx_sunlock(&proctree_lock);
1537 			return (ENOTTY);
1538 		}
1539 		tp->t_pgrp = pg;
1540 		sx_sunlock(&proctree_lock);
1541 
1542 		/* Wake up the background process groups. */
1543 		cv_broadcast(&tp->t_bgwait);
1544 		return (0);
1545 	}
1546 	case TIOCFLUSH: {
1547 		int flags = *(int *)data;
1548 
1549 		if (flags == 0)
1550 			flags = (FREAD|FWRITE);
1551 		else
1552 			flags &= (FREAD|FWRITE);
1553 		tty_flush(tp, flags);
1554 		return (0);
1555 	}
1556 	case TIOCDRAIN:
1557 		/* Drain TTY output. */
1558 		return tty_drain(tp);
1559 	case TIOCCONS:
1560 		/* Set terminal as console TTY. */
1561 		if (*(int *)data) {
1562 			error = priv_check(td, PRIV_TTY_CONSOLE);
1563 			if (error)
1564 				return (error);
1565 
1566 			/*
1567 			 * XXX: constty should really need to be locked!
1568 			 * XXX: allow disconnected constty's to be stolen!
1569 			 */
1570 
1571 			if (constty == tp)
1572 				return (0);
1573 			if (constty != NULL)
1574 				return (EBUSY);
1575 
1576 			tty_unlock(tp);
1577 			constty_set(tp);
1578 			tty_lock(tp);
1579 		} else if (constty == tp) {
1580 			constty_clear();
1581 		}
1582 		return (0);
1583 	case TIOCGWINSZ:
1584 		/* Obtain window size. */
1585 		*(struct winsize*)data = tp->t_winsize;
1586 		return (0);
1587 	case TIOCSWINSZ:
1588 		/* Set window size. */
1589 		if (bcmp(&tp->t_winsize, data, sizeof(struct winsize)) == 0)
1590 			return (0);
1591 		tp->t_winsize = *(struct winsize*)data;
1592 		tty_signal_pgrp(tp, SIGWINCH);
1593 		return (0);
1594 	case TIOCEXCL:
1595 		tp->t_flags |= TF_EXCLUDE;
1596 		return (0);
1597 	case TIOCNXCL:
1598 		tp->t_flags &= ~TF_EXCLUDE;
1599 		return (0);
1600 	case TIOCOUTQ:
1601 		*(unsigned int *)data = ttyoutq_bytesused(&tp->t_outq);
1602 		return (0);
1603 	case TIOCSTOP:
1604 		tp->t_flags |= TF_STOPPED;
1605 		ttydevsw_pktnotify(tp, TIOCPKT_STOP);
1606 		return (0);
1607 	case TIOCSTART:
1608 		tp->t_flags &= ~TF_STOPPED;
1609 		ttydevsw_outwakeup(tp);
1610 		ttydevsw_pktnotify(tp, TIOCPKT_START);
1611 		return (0);
1612 	case TIOCSTAT:
1613 		tty_info(tp);
1614 		return (0);
1615 	}
1616 
1617 #ifdef COMPAT_43TTY
1618 	return tty_ioctl_compat(tp, cmd, data, td);
1619 #else /* !COMPAT_43TTY */
1620 	return (ENOIOCTL);
1621 #endif /* COMPAT_43TTY */
1622 }
1623 
1624 int
1625 tty_ioctl(struct tty *tp, u_long cmd, void *data, struct thread *td)
1626 {
1627 	int error;
1628 
1629 	tty_lock_assert(tp, MA_OWNED);
1630 
1631 	if (tty_gone(tp))
1632 		return (ENXIO);
1633 
1634 	error = ttydevsw_ioctl(tp, cmd, data, td);
1635 	if (error == ENOIOCTL)
1636 		error = tty_generic_ioctl(tp, cmd, data, td);
1637 
1638 	return (error);
1639 }
1640 
1641 dev_t
1642 tty_udev(struct tty *tp)
1643 {
1644 	if (tp->t_dev)
1645 		return dev2udev(tp->t_dev);
1646 	else
1647 		return NODEV;
1648 }
1649 
1650 int
1651 tty_checkoutq(struct tty *tp)
1652 {
1653 
1654 	/* 256 bytes should be enough to print a log message. */
1655 	return (ttyoutq_bytesleft(&tp->t_outq) >= 256);
1656 }
1657 
1658 void
1659 tty_hiwat_in_block(struct tty *tp)
1660 {
1661 
1662 	if ((tp->t_flags & TF_HIWAT_IN) == 0 &&
1663 	    tp->t_termios.c_iflag & IXOFF &&
1664 	    tp->t_termios.c_cc[VSTOP] != _POSIX_VDISABLE) {
1665 		/*
1666 		 * Input flow control. Only enter the high watermark when we
1667 		 * can successfully store the VSTOP character.
1668 		 */
1669 		if (ttyoutq_write_nofrag(&tp->t_outq,
1670 		    &tp->t_termios.c_cc[VSTOP], 1) == 0)
1671 			tp->t_flags |= TF_HIWAT_IN;
1672 	} else {
1673 		/* No input flow control. */
1674 		tp->t_flags |= TF_HIWAT_IN;
1675 	}
1676 }
1677 
1678 void
1679 tty_hiwat_in_unblock(struct tty *tp)
1680 {
1681 
1682 	if (tp->t_flags & TF_HIWAT_IN &&
1683 	    tp->t_termios.c_iflag & IXOFF &&
1684 	    tp->t_termios.c_cc[VSTART] != _POSIX_VDISABLE) {
1685 		/*
1686 		 * Input flow control. Only leave the high watermark when we
1687 		 * can successfully store the VSTART character.
1688 		 */
1689 		if (ttyoutq_write_nofrag(&tp->t_outq,
1690 		    &tp->t_termios.c_cc[VSTART], 1) == 0)
1691 			tp->t_flags &= ~TF_HIWAT_IN;
1692 	} else {
1693 		/* No input flow control. */
1694 		tp->t_flags &= ~TF_HIWAT_IN;
1695 	}
1696 
1697 	if (!tty_gone(tp))
1698 		ttydevsw_inwakeup(tp);
1699 }
1700 
1701 /*
1702  * TTY hooks interface.
1703  */
1704 
1705 static int
1706 ttyhook_defrint(struct tty *tp, char c, int flags)
1707 {
1708 
1709 	if (ttyhook_rint_bypass(tp, &c, 1) != 1)
1710 		return (-1);
1711 
1712 	return (0);
1713 }
1714 
1715 int
1716 ttyhook_register(struct tty **rtp, struct proc *p, int fd,
1717     struct ttyhook *th, void *softc)
1718 {
1719 	struct tty *tp;
1720 	struct file *fp;
1721 	struct cdev *dev;
1722 	struct cdevsw *cdp;
1723 	struct filedesc *fdp;
1724 	int error;
1725 
1726 	/* Validate the file descriptor. */
1727 	if ((fdp = p->p_fd) == NULL)
1728 		return (EBADF);
1729 
1730 	fp = fget_unlocked(fdp, fd);
1731 	if (fp == NULL)
1732 		return (EBADF);
1733 	if (fp->f_ops == &badfileops) {
1734 		error = EBADF;
1735 		goto done1;
1736 	}
1737 
1738 	/* Make sure the vnode is bound to a character device. */
1739 	error = EINVAL;
1740 	if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR ||
1741 	    fp->f_vnode->v_rdev == NULL)
1742 		goto done1;
1743 	dev = fp->f_vnode->v_rdev;
1744 
1745 	/* Make sure it is a TTY. */
1746 	cdp = dev_refthread(dev);
1747 	if (cdp == NULL)
1748 		goto done1;
1749 	if (cdp != &ttydev_cdevsw)
1750 		goto done2;
1751 	tp = dev->si_drv1;
1752 
1753 	/* Try to attach the hook to the TTY. */
1754 	error = EBUSY;
1755 	tty_lock(tp);
1756 	MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
1757 	if (tp->t_flags & TF_HOOK)
1758 		goto done3;
1759 
1760 	tp->t_flags |= TF_HOOK;
1761 	tp->t_hook = th;
1762 	tp->t_hooksoftc = softc;
1763 	*rtp = tp;
1764 	error = 0;
1765 
1766 	/* Maybe we can switch into bypass mode now. */
1767 	ttydisc_optimize(tp);
1768 
1769 	/* Silently convert rint() calls to rint_bypass() when possible. */
1770 	if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
1771 		th->th_rint = ttyhook_defrint;
1772 
1773 done3:	tty_unlock(tp);
1774 done2:	dev_relthread(dev);
1775 done1:	fdrop(fp, curthread);
1776 	return (error);
1777 }
1778 
1779 void
1780 ttyhook_unregister(struct tty *tp)
1781 {
1782 
1783 	tty_lock_assert(tp, MA_OWNED);
1784 	MPASS(tp->t_flags & TF_HOOK);
1785 
1786 	/* Disconnect the hook. */
1787 	tp->t_flags &= ~TF_HOOK;
1788 	tp->t_hook = NULL;
1789 
1790 	/* Maybe we need to leave bypass mode. */
1791 	ttydisc_optimize(tp);
1792 
1793 	/* Maybe deallocate the TTY as well. */
1794 	tty_rel_free(tp);
1795 }
1796 
1797 /*
1798  * /dev/console handling.
1799  */
1800 
1801 static int
1802 ttyconsdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
1803 {
1804 	struct tty *tp;
1805 
1806 	/* System has no console device. */
1807 	if (dev_console_filename == NULL)
1808 		return (ENXIO);
1809 
1810 	/* Look up corresponding TTY by device name. */
1811 	sx_slock(&tty_list_sx);
1812 	TAILQ_FOREACH(tp, &tty_list, t_list) {
1813 		if (strcmp(dev_console_filename, tty_devname(tp)) == 0) {
1814 			dev_console->si_drv1 = tp;
1815 			break;
1816 		}
1817 	}
1818 	sx_sunlock(&tty_list_sx);
1819 
1820 	/* System console has no TTY associated. */
1821 	if (dev_console->si_drv1 == NULL)
1822 		return (ENXIO);
1823 
1824 	return (ttydev_open(dev, oflags, devtype, td));
1825 }
1826 
1827 static int
1828 ttyconsdev_write(struct cdev *dev, struct uio *uio, int ioflag)
1829 {
1830 
1831 	log_console(uio);
1832 
1833 	return (ttydev_write(dev, uio, ioflag));
1834 }
1835 
1836 /*
1837  * /dev/console is a little different than normal TTY's.  When opened,
1838  * it determines which TTY to use.  When data gets written to it, it
1839  * will be logged in the kernel message buffer.
1840  */
1841 static struct cdevsw ttyconsdev_cdevsw = {
1842 	.d_version	= D_VERSION,
1843 	.d_open		= ttyconsdev_open,
1844 	.d_close	= ttydev_close,
1845 	.d_read		= ttydev_read,
1846 	.d_write	= ttyconsdev_write,
1847 	.d_ioctl	= ttydev_ioctl,
1848 	.d_kqfilter	= ttydev_kqfilter,
1849 	.d_poll		= ttydev_poll,
1850 	.d_mmap		= ttydev_mmap,
1851 	.d_name		= "ttyconsdev",
1852 	.d_flags	= D_TTY,
1853 };
1854 
1855 static void
1856 ttyconsdev_init(void *unused)
1857 {
1858 
1859 	dev_console = make_dev(&ttyconsdev_cdevsw, 0, UID_ROOT, GID_WHEEL,
1860 	    0600, "console");
1861 }
1862 
1863 SYSINIT(tty, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyconsdev_init, NULL);
1864 
1865 void
1866 ttyconsdev_select(const char *name)
1867 {
1868 
1869 	dev_console_filename = name;
1870 }
1871 
1872 /*
1873  * Debugging routines.
1874  */
1875 
1876 #include "opt_ddb.h"
1877 #ifdef DDB
1878 #include <ddb/ddb.h>
1879 #include <ddb/db_sym.h>
1880 
1881 static struct {
1882 	int flag;
1883 	char val;
1884 } ttystates[] = {
1885 #if 0
1886 	{ TF_NOPREFIX,		'N' },
1887 #endif
1888 	{ TF_INITLOCK,		'I' },
1889 	{ TF_CALLOUT,		'C' },
1890 
1891 	/* Keep these together -> 'Oi' and 'Oo'. */
1892 	{ TF_OPENED,		'O' },
1893 	{ TF_OPENED_IN,		'i' },
1894 	{ TF_OPENED_OUT,	'o' },
1895 	{ TF_OPENED_CONS,	'c' },
1896 
1897 	{ TF_GONE,		'G' },
1898 	{ TF_OPENCLOSE,		'B' },
1899 	{ TF_ASYNC,		'Y' },
1900 	{ TF_LITERAL,		'L' },
1901 
1902 	/* Keep these together -> 'Hi' and 'Ho'. */
1903 	{ TF_HIWAT,		'H' },
1904 	{ TF_HIWAT_IN,		'i' },
1905 	{ TF_HIWAT_OUT,		'o' },
1906 
1907 	{ TF_STOPPED,		'S' },
1908 	{ TF_EXCLUDE,		'X' },
1909 	{ TF_BYPASS,		'l' },
1910 	{ TF_ZOMBIE,		'Z' },
1911 	{ TF_HOOK,		's' },
1912 
1913 	/* Keep these together -> 'bi' and 'bo'. */
1914 	{ TF_BUSY,		'b' },
1915 	{ TF_BUSY_IN,		'i' },
1916 	{ TF_BUSY_OUT,		'o' },
1917 
1918 	{ 0,			'\0'},
1919 };
1920 
1921 #define	TTY_FLAG_BITS \
1922 	"\20\1NOPREFIX\2INITLOCK\3CALLOUT\4OPENED_IN\5OPENED_OUT\6GONE" \
1923 	"\7OPENCLOSE\10ASYNC\11LITERAL\12HIWAT_IN\13HIWAT_OUT\14STOPPED" \
1924 	"\15EXCLUDE\16BYPASS\17ZOMBIE\20HOOK"
1925 
1926 #define DB_PRINTSYM(name, addr) \
1927 	db_printf("%s  " #name ": ", sep); \
1928 	db_printsym((db_addr_t) addr, DB_STGY_ANY); \
1929 	db_printf("\n");
1930 
1931 static void
1932 _db_show_devsw(const char *sep, const struct ttydevsw *tsw)
1933 {
1934 	db_printf("%sdevsw: ", sep);
1935 	db_printsym((db_addr_t)tsw, DB_STGY_ANY);
1936 	db_printf(" (%p)\n", tsw);
1937 	DB_PRINTSYM(open, tsw->tsw_open);
1938 	DB_PRINTSYM(close, tsw->tsw_close);
1939 	DB_PRINTSYM(outwakeup, tsw->tsw_outwakeup);
1940 	DB_PRINTSYM(inwakeup, tsw->tsw_inwakeup);
1941 	DB_PRINTSYM(ioctl, tsw->tsw_ioctl);
1942 	DB_PRINTSYM(param, tsw->tsw_param);
1943 	DB_PRINTSYM(modem, tsw->tsw_modem);
1944 	DB_PRINTSYM(mmap, tsw->tsw_mmap);
1945 	DB_PRINTSYM(pktnotify, tsw->tsw_pktnotify);
1946 	DB_PRINTSYM(free, tsw->tsw_free);
1947 }
1948 static void
1949 _db_show_hooks(const char *sep, const struct ttyhook *th)
1950 {
1951 	db_printf("%shook: ", sep);
1952 	db_printsym((db_addr_t)th, DB_STGY_ANY);
1953 	db_printf(" (%p)\n", th);
1954 	if (th == NULL)
1955 		return;
1956 	DB_PRINTSYM(rint, th->th_rint);
1957 	DB_PRINTSYM(rint_bypass, th->th_rint_bypass);
1958 	DB_PRINTSYM(rint_done, th->th_rint_done);
1959 	DB_PRINTSYM(rint_poll, th->th_rint_poll);
1960 	DB_PRINTSYM(getc_inject, th->th_getc_inject);
1961 	DB_PRINTSYM(getc_capture, th->th_getc_capture);
1962 	DB_PRINTSYM(getc_poll, th->th_getc_poll);
1963 	DB_PRINTSYM(close, th->th_close);
1964 }
1965 
1966 static void
1967 _db_show_termios(const char *name, const struct termios *t)
1968 {
1969 
1970 	db_printf("%s: iflag 0x%x oflag 0x%x cflag 0x%x "
1971 	    "lflag 0x%x ispeed %u ospeed %u\n", name,
1972 	    t->c_iflag, t->c_oflag, t->c_cflag, t->c_lflag,
1973 	    t->c_ispeed, t->c_ospeed);
1974 }
1975 
1976 /* DDB command to show TTY statistics. */
1977 DB_SHOW_COMMAND(tty, db_show_tty)
1978 {
1979 	struct tty *tp;
1980 
1981 	if (!have_addr) {
1982 		db_printf("usage: show tty <addr>\n");
1983 		return;
1984 	}
1985 	tp = (struct tty *)addr;
1986 
1987 	db_printf("0x%p: %s\n", tp, tty_devname(tp));
1988 	db_printf("\tmtx: %p\n", tp->t_mtx);
1989 	db_printf("\tflags: %b\n", tp->t_flags, TTY_FLAG_BITS);
1990 	db_printf("\trevokecnt: %u\n", tp->t_revokecnt);
1991 
1992 	/* Buffering mechanisms. */
1993 	db_printf("\tinq: %p begin %u linestart %u reprint %u end %u "
1994 	    "nblocks %u quota %u\n", &tp->t_inq, tp->t_inq.ti_begin,
1995 	    tp->t_inq.ti_linestart, tp->t_inq.ti_reprint, tp->t_inq.ti_end,
1996 	    tp->t_inq.ti_nblocks, tp->t_inq.ti_quota);
1997 	db_printf("\toutq: %p begin %u end %u nblocks %u quota %u\n",
1998 	    &tp->t_outq, tp->t_outq.to_begin, tp->t_outq.to_end,
1999 	    tp->t_outq.to_nblocks, tp->t_outq.to_quota);
2000 	db_printf("\tinlow: %zu\n", tp->t_inlow);
2001 	db_printf("\toutlow: %zu\n", tp->t_outlow);
2002 	_db_show_termios("\ttermios", &tp->t_termios);
2003 	db_printf("\twinsize: row %u col %u xpixel %u ypixel %u\n",
2004 	    tp->t_winsize.ws_row, tp->t_winsize.ws_col,
2005 	    tp->t_winsize.ws_xpixel, tp->t_winsize.ws_ypixel);
2006 	db_printf("\tcolumn: %u\n", tp->t_column);
2007 	db_printf("\twritepos: %u\n", tp->t_writepos);
2008 	db_printf("\tcompatflags: 0x%x\n", tp->t_compatflags);
2009 
2010 	/* Init/lock-state devices. */
2011 	_db_show_termios("\ttermios_init_in", &tp->t_termios_init_in);
2012 	_db_show_termios("\ttermios_init_out", &tp->t_termios_init_out);
2013 	_db_show_termios("\ttermios_lock_in", &tp->t_termios_lock_in);
2014 	_db_show_termios("\ttermios_lock_out", &tp->t_termios_lock_out);
2015 
2016 	/* Hooks */
2017 	_db_show_devsw("\t", tp->t_devsw);
2018 	_db_show_hooks("\t", tp->t_hook);
2019 
2020 	/* Process info. */
2021 	db_printf("\tpgrp: %p gid %d jobc %d\n", tp->t_pgrp,
2022 	    tp->t_pgrp ? tp->t_pgrp->pg_id : 0,
2023 	    tp->t_pgrp ? tp->t_pgrp->pg_jobc : 0);
2024 	db_printf("\tsession: %p", tp->t_session);
2025 	if (tp->t_session != NULL)
2026 	    db_printf(" count %u leader %p tty %p sid %d login %s",
2027 		tp->t_session->s_count, tp->t_session->s_leader,
2028 		tp->t_session->s_ttyp, tp->t_session->s_sid,
2029 		tp->t_session->s_login);
2030 	db_printf("\n");
2031 	db_printf("\tsessioncnt: %u\n", tp->t_sessioncnt);
2032 	db_printf("\tdevswsoftc: %p\n", tp->t_devswsoftc);
2033 	db_printf("\thooksoftc: %p\n", tp->t_hooksoftc);
2034 	db_printf("\tdev: %p\n", tp->t_dev);
2035 }
2036 
2037 /* DDB command to list TTYs. */
2038 DB_SHOW_ALL_COMMAND(ttys, db_show_all_ttys)
2039 {
2040 	struct tty *tp;
2041 	size_t isiz, osiz;
2042 	int i, j;
2043 
2044 	/* Make the output look like `pstat -t'. */
2045 	db_printf("PTR        ");
2046 #if defined(__LP64__)
2047 	db_printf("        ");
2048 #endif
2049 	db_printf("      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   "
2050 	    "COL  SESS  PGID STATE\n");
2051 
2052 	TAILQ_FOREACH(tp, &tty_list, t_list) {
2053 		isiz = tp->t_inq.ti_nblocks * TTYINQ_DATASIZE;
2054 		osiz = tp->t_outq.to_nblocks * TTYOUTQ_DATASIZE;
2055 
2056 		db_printf("%p %10s %5zu %4u %4u %4zu %5zu %4u %4zu %5u %5d %5d ",
2057 		    tp,
2058 		    tty_devname(tp),
2059 		    isiz,
2060 		    tp->t_inq.ti_linestart - tp->t_inq.ti_begin,
2061 		    tp->t_inq.ti_end - tp->t_inq.ti_linestart,
2062 		    isiz - tp->t_inlow,
2063 		    osiz,
2064 		    tp->t_outq.to_end - tp->t_outq.to_begin,
2065 		    osiz - tp->t_outlow,
2066 		    MIN(tp->t_column, 99999),
2067 		    tp->t_session ? tp->t_session->s_sid : 0,
2068 		    tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
2069 
2070 		/* Flag bits. */
2071 		for (i = j = 0; ttystates[i].flag; i++)
2072 			if (tp->t_flags & ttystates[i].flag) {
2073 				db_printf("%c", ttystates[i].val);
2074 				j++;
2075 			}
2076 		if (j == 0)
2077 			db_printf("-");
2078 		db_printf("\n");
2079 	}
2080 }
2081 #endif /* DDB */
2082