xref: /freebsd/sys/kern/tty.c (revision 129d3046ef0427d3b22b78a71f3494854d817fba)
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)
889 {
890 
891 	return (tty_alloc_mutex(tsw, sc, NULL));
892 }
893 
894 struct tty *
895 tty_alloc_mutex(struct ttydevsw *tsw, void *sc, struct mtx *mutex)
896 {
897 	struct tty *tp;
898 
899 	/* Make sure the driver defines all routines. */
900 #define PATCH_FUNC(x) do {				\
901 	if (tsw->tsw_ ## x == NULL)			\
902 		tsw->tsw_ ## x = ttydevsw_def ## x;	\
903 } while (0)
904 	PATCH_FUNC(open);
905 	PATCH_FUNC(close);
906 	PATCH_FUNC(outwakeup);
907 	PATCH_FUNC(inwakeup);
908 	PATCH_FUNC(ioctl);
909 	PATCH_FUNC(param);
910 	PATCH_FUNC(modem);
911 	PATCH_FUNC(mmap);
912 	PATCH_FUNC(pktnotify);
913 	PATCH_FUNC(free);
914 #undef PATCH_FUNC
915 
916 	tp = malloc(sizeof(struct tty), M_TTY, M_WAITOK|M_ZERO);
917 	tp->t_devsw = tsw;
918 	tp->t_devswsoftc = sc;
919 	tp->t_flags = tsw->tsw_flags;
920 
921 	tty_init_termios(tp);
922 
923 	cv_init(&tp->t_inwait, "ttyin");
924 	cv_init(&tp->t_outwait, "ttyout");
925 	cv_init(&tp->t_bgwait, "ttybg");
926 	cv_init(&tp->t_dcdwait, "ttydcd");
927 
928 	/* Allow drivers to use a custom mutex to lock the TTY. */
929 	if (mutex != NULL) {
930 		tp->t_mtx = mutex;
931 	} else {
932 		tp->t_mtx = &tp->t_mtxobj;
933 		mtx_init(&tp->t_mtxobj, "ttymtx", NULL, MTX_DEF);
934 	}
935 
936 	knlist_init(&tp->t_inpoll.si_note, tp->t_mtx, NULL, NULL, NULL);
937 	knlist_init(&tp->t_outpoll.si_note, tp->t_mtx, NULL, NULL, NULL);
938 
939 	sx_xlock(&tty_list_sx);
940 	TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
941 	tty_list_count++;
942 	sx_xunlock(&tty_list_sx);
943 
944 	return (tp);
945 }
946 
947 static void
948 tty_dealloc(void *arg)
949 {
950 	struct tty *tp = arg;
951 
952 	sx_xlock(&tty_list_sx);
953 	TAILQ_REMOVE(&tty_list, tp, t_list);
954 	tty_list_count--;
955 	sx_xunlock(&tty_list_sx);
956 
957 	/* Make sure we haven't leaked buffers. */
958 	MPASS(ttyinq_getsize(&tp->t_inq) == 0);
959 	MPASS(ttyoutq_getsize(&tp->t_outq) == 0);
960 
961 	knlist_destroy(&tp->t_inpoll.si_note);
962 	knlist_destroy(&tp->t_outpoll.si_note);
963 
964 	cv_destroy(&tp->t_inwait);
965 	cv_destroy(&tp->t_outwait);
966 	cv_destroy(&tp->t_bgwait);
967 	cv_destroy(&tp->t_dcdwait);
968 
969 	if (tp->t_mtx == &tp->t_mtxobj)
970 		mtx_destroy(&tp->t_mtxobj);
971 	ttydevsw_free(tp);
972 	free(tp, M_TTY);
973 }
974 
975 static void
976 tty_rel_free(struct tty *tp)
977 {
978 	struct cdev *dev;
979 
980 	tty_lock_assert(tp, MA_OWNED);
981 
982 #define	TF_ACTIVITY	(TF_GONE|TF_OPENED|TF_HOOK|TF_OPENCLOSE)
983 	if (tp->t_sessioncnt != 0 || (tp->t_flags & TF_ACTIVITY) != TF_GONE) {
984 		/* TTY is still in use. */
985 		tty_unlock(tp);
986 		return;
987 	}
988 
989 	/* TTY can be deallocated. */
990 	dev = tp->t_dev;
991 	tp->t_dev = NULL;
992 	tty_unlock(tp);
993 
994 	destroy_dev_sched_cb(dev, tty_dealloc, tp);
995 }
996 
997 void
998 tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
999 {
1000 	MPASS(tp->t_sessioncnt > 0);
1001 	tty_lock_assert(tp, MA_OWNED);
1002 
1003 	if (tp->t_pgrp == pg)
1004 		tp->t_pgrp = NULL;
1005 
1006 	tty_unlock(tp);
1007 }
1008 
1009 void
1010 tty_rel_sess(struct tty *tp, struct session *sess)
1011 {
1012 	MPASS(tp->t_sessioncnt > 0);
1013 
1014 	/* Current session has left. */
1015 	if (tp->t_session == sess) {
1016 		tp->t_session = NULL;
1017 		MPASS(tp->t_pgrp == NULL);
1018 	}
1019 	tp->t_sessioncnt--;
1020 	tty_rel_free(tp);
1021 }
1022 
1023 void
1024 tty_rel_gone(struct tty *tp)
1025 {
1026 	MPASS(!tty_gone(tp));
1027 
1028 	/* Simulate carrier removal. */
1029 	ttydisc_modem(tp, 0);
1030 
1031 	/* Wake up all blocked threads. */
1032 	tty_wakeup(tp, FREAD|FWRITE);
1033 	cv_broadcast(&tp->t_bgwait);
1034 	cv_broadcast(&tp->t_dcdwait);
1035 
1036 	tp->t_flags |= TF_GONE;
1037 	tty_rel_free(tp);
1038 }
1039 
1040 /*
1041  * Exposing information about current TTY's through sysctl
1042  */
1043 
1044 static void
1045 tty_to_xtty(struct tty *tp, struct xtty *xt)
1046 {
1047 	tty_lock_assert(tp, MA_OWNED);
1048 
1049 	xt->xt_size = sizeof(struct xtty);
1050 	xt->xt_insize = ttyinq_getsize(&tp->t_inq);
1051 	xt->xt_incc = ttyinq_bytescanonicalized(&tp->t_inq);
1052 	xt->xt_inlc = ttyinq_bytesline(&tp->t_inq);
1053 	xt->xt_inlow = tp->t_inlow;
1054 	xt->xt_outsize = ttyoutq_getsize(&tp->t_outq);
1055 	xt->xt_outcc = ttyoutq_bytesused(&tp->t_outq);
1056 	xt->xt_outlow = tp->t_outlow;
1057 	xt->xt_column = tp->t_column;
1058 	xt->xt_pgid = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
1059 	xt->xt_sid = tp->t_session ? tp->t_session->s_sid : 0;
1060 	xt->xt_flags = tp->t_flags;
1061 	xt->xt_dev = tp->t_dev ? dev2udev(tp->t_dev) : NODEV;
1062 }
1063 
1064 static int
1065 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
1066 {
1067 	unsigned long lsize;
1068 	struct xtty *xtlist, *xt;
1069 	struct tty *tp;
1070 	int error;
1071 
1072 	sx_slock(&tty_list_sx);
1073 	lsize = tty_list_count * sizeof(struct xtty);
1074 	if (lsize == 0) {
1075 		sx_sunlock(&tty_list_sx);
1076 		return (0);
1077 	}
1078 
1079 	xtlist = xt = malloc(lsize, M_TTY, M_WAITOK);
1080 
1081 	TAILQ_FOREACH(tp, &tty_list, t_list) {
1082 		tty_lock(tp);
1083 		tty_to_xtty(tp, xt);
1084 		tty_unlock(tp);
1085 		xt++;
1086 	}
1087 	sx_sunlock(&tty_list_sx);
1088 
1089 	error = SYSCTL_OUT(req, xtlist, lsize);
1090 	free(xtlist, M_TTY);
1091 	return (error);
1092 }
1093 
1094 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
1095 	0, 0, sysctl_kern_ttys, "S,xtty", "List of TTYs");
1096 
1097 /*
1098  * Device node creation. Device has been set up, now we can expose it to
1099  * the user.
1100  */
1101 
1102 void
1103 tty_makedev(struct tty *tp, struct ucred *cred, const char *fmt, ...)
1104 {
1105 	va_list ap;
1106 	struct cdev *dev;
1107 	const char *prefix = "tty";
1108 	char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
1109 	uid_t uid;
1110 	gid_t gid;
1111 	mode_t mode;
1112 
1113 	/* Remove "tty" prefix from devices like PTY's. */
1114 	if (tp->t_flags & TF_NOPREFIX)
1115 		prefix = "";
1116 
1117 	va_start(ap, fmt);
1118 	vsnrprintf(name, sizeof name, 32, fmt, ap);
1119 	va_end(ap);
1120 
1121 	if (cred == NULL) {
1122 		/* System device. */
1123 		uid = UID_ROOT;
1124 		gid = GID_WHEEL;
1125 		mode = S_IRUSR|S_IWUSR;
1126 	} else {
1127 		/* User device. */
1128 		uid = cred->cr_ruid;
1129 		gid = GID_TTY;
1130 		mode = S_IRUSR|S_IWUSR|S_IWGRP;
1131 	}
1132 
1133 	/* Master call-in device. */
1134 	dev = make_dev_cred(&ttydev_cdevsw, 0, cred,
1135 	    uid, gid, mode, "%s%s", prefix, name);
1136 	dev->si_drv1 = tp;
1137 	tp->t_dev = dev;
1138 
1139 	/* Slave call-in devices. */
1140 	if (tp->t_flags & TF_INITLOCK) {
1141 		dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1142 		    uid, gid, mode, "%s%s.init", prefix, name);
1143 		dev_depends(tp->t_dev, dev);
1144 		dev->si_drv1 = tp;
1145 		dev->si_drv2 = &tp->t_termios_init_in;
1146 
1147 		dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1148 		    uid, gid, mode, "%s%s.lock", prefix, name);
1149 		dev_depends(tp->t_dev, dev);
1150 		dev->si_drv1 = tp;
1151 		dev->si_drv2 = &tp->t_termios_lock_in;
1152 	}
1153 
1154 	/* Call-out devices. */
1155 	if (tp->t_flags & TF_CALLOUT) {
1156 		dev = make_dev_cred(&ttydev_cdevsw, 0, cred,
1157 		    UID_UUCP, GID_DIALER, 0660, "cua%s", name);
1158 		dev_depends(tp->t_dev, dev);
1159 		dev->si_drv1 = tp;
1160 
1161 		/* Slave call-out devices. */
1162 		if (tp->t_flags & TF_INITLOCK) {
1163 			dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1164 			    UID_UUCP, GID_DIALER, 0660, "cua%s.init", name);
1165 			dev_depends(tp->t_dev, dev);
1166 			dev->si_drv1 = tp;
1167 			dev->si_drv2 = &tp->t_termios_init_out;
1168 
1169 			dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1170 			    UID_UUCP, GID_DIALER, 0660, "cua%s.lock", name);
1171 			dev_depends(tp->t_dev, dev);
1172 			dev->si_drv1 = tp;
1173 			dev->si_drv2 = &tp->t_termios_lock_out;
1174 		}
1175 	}
1176 }
1177 
1178 /*
1179  * Signalling processes.
1180  */
1181 
1182 void
1183 tty_signal_sessleader(struct tty *tp, int sig)
1184 {
1185 	struct proc *p;
1186 
1187 	tty_lock_assert(tp, MA_OWNED);
1188 	MPASS(sig >= 1 && sig < NSIG);
1189 
1190 	/* Make signals start output again. */
1191 	tp->t_flags &= ~TF_STOPPED;
1192 
1193 	if (tp->t_session != NULL && tp->t_session->s_leader != NULL) {
1194 		p = tp->t_session->s_leader;
1195 		PROC_LOCK(p);
1196 		psignal(p, sig);
1197 		PROC_UNLOCK(p);
1198 	}
1199 }
1200 
1201 void
1202 tty_signal_pgrp(struct tty *tp, int sig)
1203 {
1204 	tty_lock_assert(tp, MA_OWNED);
1205 	MPASS(sig >= 1 && sig < NSIG);
1206 
1207 	/* Make signals start output again. */
1208 	tp->t_flags &= ~TF_STOPPED;
1209 
1210 	if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
1211 		tty_info(tp);
1212 	if (tp->t_pgrp != NULL) {
1213 		PGRP_LOCK(tp->t_pgrp);
1214 		pgsignal(tp->t_pgrp, sig, 1);
1215 		PGRP_UNLOCK(tp->t_pgrp);
1216 	}
1217 }
1218 
1219 void
1220 tty_wakeup(struct tty *tp, int flags)
1221 {
1222 	if (tp->t_flags & TF_ASYNC && tp->t_sigio != NULL)
1223 		pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
1224 
1225 	if (flags & FWRITE) {
1226 		cv_broadcast(&tp->t_outwait);
1227 		selwakeup(&tp->t_outpoll);
1228 		KNOTE_LOCKED(&tp->t_outpoll.si_note, 0);
1229 	}
1230 	if (flags & FREAD) {
1231 		cv_broadcast(&tp->t_inwait);
1232 		selwakeup(&tp->t_inpoll);
1233 		KNOTE_LOCKED(&tp->t_inpoll.si_note, 0);
1234 	}
1235 }
1236 
1237 int
1238 tty_wait(struct tty *tp, struct cv *cv)
1239 {
1240 	int error;
1241 	int revokecnt = tp->t_revokecnt;
1242 
1243 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1244 	MPASS(!tty_gone(tp));
1245 
1246 	error = cv_wait_sig(cv, tp->t_mtx);
1247 
1248 	/* Restart the system call when we may have been revoked. */
1249 	if (tp->t_revokecnt != revokecnt)
1250 		return (ERESTART);
1251 
1252 	/* Bail out when the device slipped away. */
1253 	if (tty_gone(tp))
1254 		return (ENXIO);
1255 
1256 	return (error);
1257 }
1258 
1259 int
1260 tty_timedwait(struct tty *tp, struct cv *cv, int hz)
1261 {
1262 	int error;
1263 	int revokecnt = tp->t_revokecnt;
1264 
1265 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1266 	MPASS(!tty_gone(tp));
1267 
1268 	error = cv_timedwait_sig(cv, tp->t_mtx, hz);
1269 
1270 	/* Restart the system call when we may have been revoked. */
1271 	if (tp->t_revokecnt != revokecnt)
1272 		return (ERESTART);
1273 
1274 	/* Bail out when the device slipped away. */
1275 	if (tty_gone(tp))
1276 		return (ENXIO);
1277 
1278 	return (error);
1279 }
1280 
1281 void
1282 tty_flush(struct tty *tp, int flags)
1283 {
1284 	if (flags & FWRITE) {
1285 		tp->t_flags &= ~TF_HIWAT_OUT;
1286 		ttyoutq_flush(&tp->t_outq);
1287 		tty_wakeup(tp, FWRITE);
1288 		ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
1289 	}
1290 	if (flags & FREAD) {
1291 		tty_hiwat_in_unblock(tp);
1292 		ttyinq_flush(&tp->t_inq);
1293 		ttydevsw_inwakeup(tp);
1294 		ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
1295 	}
1296 }
1297 
1298 static int
1299 tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, struct thread *td)
1300 {
1301 	int error;
1302 
1303 	switch (cmd) {
1304 	/*
1305 	 * Modem commands.
1306 	 * The SER_* and TIOCM_* flags are the same, but one bit
1307 	 * shifted. I don't know why.
1308 	 */
1309 	case TIOCSDTR:
1310 		ttydevsw_modem(tp, SER_DTR, 0);
1311 		return (0);
1312 	case TIOCCDTR:
1313 		ttydevsw_modem(tp, 0, SER_DTR);
1314 		return (0);
1315 	case TIOCMSET: {
1316 		int bits = *(int *)data;
1317 		ttydevsw_modem(tp,
1318 		    (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1,
1319 		    ((~bits) & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1320 		return (0);
1321 	}
1322 	case TIOCMBIS: {
1323 		int bits = *(int *)data;
1324 		ttydevsw_modem(tp, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1, 0);
1325 		return (0);
1326 	}
1327 	case TIOCMBIC: {
1328 		int bits = *(int *)data;
1329 		ttydevsw_modem(tp, 0, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1330 		return (0);
1331 	}
1332 	case TIOCMGET:
1333 		*(int *)data = TIOCM_LE + (ttydevsw_modem(tp, 0, 0) << 1);
1334 		return (0);
1335 
1336 	case FIOASYNC:
1337 		if (*(int *)data)
1338 			tp->t_flags |= TF_ASYNC;
1339 		else
1340 			tp->t_flags &= ~TF_ASYNC;
1341 		return (0);
1342 	case FIONBIO:
1343 		/* This device supports non-blocking operation. */
1344 		return (0);
1345 	case FIONREAD:
1346 		*(int *)data = ttyinq_bytescanonicalized(&tp->t_inq);
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_ttyvp != NULL ||
1490 		    (tp->t_session != NULL && tp->t_session->s_ttyvp != NULL)) {
1491 			/*
1492 			 * There is already a relation between a TTY and
1493 			 * a session, or the caller is not the session
1494 			 * leader.
1495 			 *
1496 			 * Allow the TTY to be stolen when the vnode is
1497 			 * NULL, but the reference to the TTY is still
1498 			 * active.
1499 			 */
1500 			sx_xunlock(&proctree_lock);
1501 			return (EPERM);
1502 		}
1503 
1504 		/* Connect the session to the TTY. */
1505 		tp->t_session = p->p_session;
1506 		tp->t_session->s_ttyp = tp;
1507 		tp->t_sessioncnt++;
1508 		sx_xunlock(&proctree_lock);
1509 
1510 		/* Assign foreground process group. */
1511 		tp->t_pgrp = p->p_pgrp;
1512 		PROC_LOCK(p);
1513 		p->p_flag |= P_CONTROLT;
1514 		PROC_UNLOCK(p);
1515 
1516 		return (0);
1517 	}
1518 	case TIOCSPGRP: {
1519 		struct pgrp *pg;
1520 
1521 		/*
1522 		 * XXX: Temporarily unlock the TTY to locate the process
1523 		 * group. This code would be lot nicer if we would ever
1524 		 * decompose proctree_lock.
1525 		 */
1526 		tty_unlock(tp);
1527 		sx_slock(&proctree_lock);
1528 		pg = pgfind(*(int *)data);
1529 		if (pg != NULL)
1530 			PGRP_UNLOCK(pg);
1531 		if (pg == NULL || pg->pg_session != td->td_proc->p_session) {
1532 			sx_sunlock(&proctree_lock);
1533 			tty_lock(tp);
1534 			return (EPERM);
1535 		}
1536 		tty_lock(tp);
1537 
1538 		/*
1539 		 * Determine if this TTY is the controlling TTY after
1540 		 * relocking the TTY.
1541 		 */
1542 		if (!tty_is_ctty(tp, td->td_proc)) {
1543 			sx_sunlock(&proctree_lock);
1544 			return (ENOTTY);
1545 		}
1546 		tp->t_pgrp = pg;
1547 		sx_sunlock(&proctree_lock);
1548 
1549 		/* Wake up the background process groups. */
1550 		cv_broadcast(&tp->t_bgwait);
1551 		return (0);
1552 	}
1553 	case TIOCFLUSH: {
1554 		int flags = *(int *)data;
1555 
1556 		if (flags == 0)
1557 			flags = (FREAD|FWRITE);
1558 		else
1559 			flags &= (FREAD|FWRITE);
1560 		tty_flush(tp, flags);
1561 		return (0);
1562 	}
1563 	case TIOCDRAIN:
1564 		/* Drain TTY output. */
1565 		return tty_drain(tp);
1566 	case TIOCCONS:
1567 		/* Set terminal as console TTY. */
1568 		if (*(int *)data) {
1569 			error = priv_check(td, PRIV_TTY_CONSOLE);
1570 			if (error)
1571 				return (error);
1572 
1573 			/*
1574 			 * XXX: constty should really need to be locked!
1575 			 * XXX: allow disconnected constty's to be stolen!
1576 			 */
1577 
1578 			if (constty == tp)
1579 				return (0);
1580 			if (constty != NULL)
1581 				return (EBUSY);
1582 
1583 			tty_unlock(tp);
1584 			constty_set(tp);
1585 			tty_lock(tp);
1586 		} else if (constty == tp) {
1587 			constty_clear();
1588 		}
1589 		return (0);
1590 	case TIOCGWINSZ:
1591 		/* Obtain window size. */
1592 		*(struct winsize*)data = tp->t_winsize;
1593 		return (0);
1594 	case TIOCSWINSZ:
1595 		/* Set window size. */
1596 		if (bcmp(&tp->t_winsize, data, sizeof(struct winsize)) == 0)
1597 			return (0);
1598 		tp->t_winsize = *(struct winsize*)data;
1599 		tty_signal_pgrp(tp, SIGWINCH);
1600 		return (0);
1601 	case TIOCEXCL:
1602 		tp->t_flags |= TF_EXCLUDE;
1603 		return (0);
1604 	case TIOCNXCL:
1605 		tp->t_flags &= ~TF_EXCLUDE;
1606 		return (0);
1607 	case TIOCOUTQ:
1608 		*(unsigned int *)data = ttyoutq_bytesused(&tp->t_outq);
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 	/* Make sure the vnode is bound to a character device. */
1746 	error = EINVAL;
1747 	if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR ||
1748 	    fp->f_vnode->v_rdev == NULL)
1749 		goto done1;
1750 	dev = fp->f_vnode->v_rdev;
1751 
1752 	/* Make sure it is a TTY. */
1753 	cdp = dev_refthread(dev);
1754 	if (cdp == NULL)
1755 		goto done1;
1756 	if (cdp != &ttydev_cdevsw)
1757 		goto done2;
1758 	tp = dev->si_drv1;
1759 
1760 	/* Try to attach the hook to the TTY. */
1761 	error = EBUSY;
1762 	tty_lock(tp);
1763 	MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
1764 	if (tp->t_flags & TF_HOOK)
1765 		goto done3;
1766 
1767 	tp->t_flags |= TF_HOOK;
1768 	tp->t_hook = th;
1769 	tp->t_hooksoftc = softc;
1770 	*rtp = tp;
1771 	error = 0;
1772 
1773 	/* Maybe we can switch into bypass mode now. */
1774 	ttydisc_optimize(tp);
1775 
1776 	/* Silently convert rint() calls to rint_bypass() when possible. */
1777 	if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
1778 		th->th_rint = ttyhook_defrint;
1779 
1780 done3:	tty_unlock(tp);
1781 done2:	dev_relthread(dev);
1782 done1:	fdrop(fp, curthread);
1783 	return (error);
1784 }
1785 
1786 void
1787 ttyhook_unregister(struct tty *tp)
1788 {
1789 
1790 	tty_lock_assert(tp, MA_OWNED);
1791 	MPASS(tp->t_flags & TF_HOOK);
1792 
1793 	/* Disconnect the hook. */
1794 	tp->t_flags &= ~TF_HOOK;
1795 	tp->t_hook = NULL;
1796 
1797 	/* Maybe we need to leave bypass mode. */
1798 	ttydisc_optimize(tp);
1799 
1800 	/* Maybe deallocate the TTY as well. */
1801 	tty_rel_free(tp);
1802 }
1803 
1804 /*
1805  * /dev/console handling.
1806  */
1807 
1808 static int
1809 ttyconsdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
1810 {
1811 	struct tty *tp;
1812 
1813 	/* System has no console device. */
1814 	if (dev_console_filename == NULL)
1815 		return (ENXIO);
1816 
1817 	/* Look up corresponding TTY by device name. */
1818 	sx_slock(&tty_list_sx);
1819 	TAILQ_FOREACH(tp, &tty_list, t_list) {
1820 		if (strcmp(dev_console_filename, tty_devname(tp)) == 0) {
1821 			dev_console->si_drv1 = tp;
1822 			break;
1823 		}
1824 	}
1825 	sx_sunlock(&tty_list_sx);
1826 
1827 	/* System console has no TTY associated. */
1828 	if (dev_console->si_drv1 == NULL)
1829 		return (ENXIO);
1830 
1831 	return (ttydev_open(dev, oflags, devtype, td));
1832 }
1833 
1834 static int
1835 ttyconsdev_write(struct cdev *dev, struct uio *uio, int ioflag)
1836 {
1837 
1838 	log_console(uio);
1839 
1840 	return (ttydev_write(dev, uio, ioflag));
1841 }
1842 
1843 /*
1844  * /dev/console is a little different than normal TTY's.  When opened,
1845  * it determines which TTY to use.  When data gets written to it, it
1846  * will be logged in the kernel message buffer.
1847  */
1848 static struct cdevsw ttyconsdev_cdevsw = {
1849 	.d_version	= D_VERSION,
1850 	.d_open		= ttyconsdev_open,
1851 	.d_close	= ttydev_close,
1852 	.d_read		= ttydev_read,
1853 	.d_write	= ttyconsdev_write,
1854 	.d_ioctl	= ttydev_ioctl,
1855 	.d_kqfilter	= ttydev_kqfilter,
1856 	.d_poll		= ttydev_poll,
1857 	.d_mmap		= ttydev_mmap,
1858 	.d_name		= "ttyconsdev",
1859 	.d_flags	= D_TTY,
1860 };
1861 
1862 static void
1863 ttyconsdev_init(void *unused)
1864 {
1865 
1866 	dev_console = make_dev(&ttyconsdev_cdevsw, 0, UID_ROOT, GID_WHEEL,
1867 	    0600, "console");
1868 }
1869 
1870 SYSINIT(tty, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyconsdev_init, NULL);
1871 
1872 void
1873 ttyconsdev_select(const char *name)
1874 {
1875 
1876 	dev_console_filename = name;
1877 }
1878 
1879 /*
1880  * Debugging routines.
1881  */
1882 
1883 #include "opt_ddb.h"
1884 #ifdef DDB
1885 #include <ddb/ddb.h>
1886 #include <ddb/db_sym.h>
1887 
1888 static struct {
1889 	int flag;
1890 	char val;
1891 } ttystates[] = {
1892 #if 0
1893 	{ TF_NOPREFIX,		'N' },
1894 #endif
1895 	{ TF_INITLOCK,		'I' },
1896 	{ TF_CALLOUT,		'C' },
1897 
1898 	/* Keep these together -> 'Oi' and 'Oo'. */
1899 	{ TF_OPENED,		'O' },
1900 	{ TF_OPENED_IN,		'i' },
1901 	{ TF_OPENED_OUT,	'o' },
1902 	{ TF_OPENED_CONS,	'c' },
1903 
1904 	{ TF_GONE,		'G' },
1905 	{ TF_OPENCLOSE,		'B' },
1906 	{ TF_ASYNC,		'Y' },
1907 	{ TF_LITERAL,		'L' },
1908 
1909 	/* Keep these together -> 'Hi' and 'Ho'. */
1910 	{ TF_HIWAT,		'H' },
1911 	{ TF_HIWAT_IN,		'i' },
1912 	{ TF_HIWAT_OUT,		'o' },
1913 
1914 	{ TF_STOPPED,		'S' },
1915 	{ TF_EXCLUDE,		'X' },
1916 	{ TF_BYPASS,		'l' },
1917 	{ TF_ZOMBIE,		'Z' },
1918 	{ TF_HOOK,		's' },
1919 
1920 	/* Keep these together -> 'bi' and 'bo'. */
1921 	{ TF_BUSY,		'b' },
1922 	{ TF_BUSY_IN,		'i' },
1923 	{ TF_BUSY_OUT,		'o' },
1924 
1925 	{ 0,			'\0'},
1926 };
1927 
1928 #define	TTY_FLAG_BITS \
1929 	"\20\1NOPREFIX\2INITLOCK\3CALLOUT\4OPENED_IN\5OPENED_OUT\6GONE" \
1930 	"\7OPENCLOSE\10ASYNC\11LITERAL\12HIWAT_IN\13HIWAT_OUT\14STOPPED" \
1931 	"\15EXCLUDE\16BYPASS\17ZOMBIE\20HOOK"
1932 
1933 #define DB_PRINTSYM(name, addr) \
1934 	db_printf("%s  " #name ": ", sep); \
1935 	db_printsym((db_addr_t) addr, DB_STGY_ANY); \
1936 	db_printf("\n");
1937 
1938 static void
1939 _db_show_devsw(const char *sep, const struct ttydevsw *tsw)
1940 {
1941 	db_printf("%sdevsw: ", sep);
1942 	db_printsym((db_addr_t)tsw, DB_STGY_ANY);
1943 	db_printf(" (%p)\n", tsw);
1944 	DB_PRINTSYM(open, tsw->tsw_open);
1945 	DB_PRINTSYM(close, tsw->tsw_close);
1946 	DB_PRINTSYM(outwakeup, tsw->tsw_outwakeup);
1947 	DB_PRINTSYM(inwakeup, tsw->tsw_inwakeup);
1948 	DB_PRINTSYM(ioctl, tsw->tsw_ioctl);
1949 	DB_PRINTSYM(param, tsw->tsw_param);
1950 	DB_PRINTSYM(modem, tsw->tsw_modem);
1951 	DB_PRINTSYM(mmap, tsw->tsw_mmap);
1952 	DB_PRINTSYM(pktnotify, tsw->tsw_pktnotify);
1953 	DB_PRINTSYM(free, tsw->tsw_free);
1954 }
1955 static void
1956 _db_show_hooks(const char *sep, const struct ttyhook *th)
1957 {
1958 	db_printf("%shook: ", sep);
1959 	db_printsym((db_addr_t)th, DB_STGY_ANY);
1960 	db_printf(" (%p)\n", th);
1961 	if (th == NULL)
1962 		return;
1963 	DB_PRINTSYM(rint, th->th_rint);
1964 	DB_PRINTSYM(rint_bypass, th->th_rint_bypass);
1965 	DB_PRINTSYM(rint_done, th->th_rint_done);
1966 	DB_PRINTSYM(rint_poll, th->th_rint_poll);
1967 	DB_PRINTSYM(getc_inject, th->th_getc_inject);
1968 	DB_PRINTSYM(getc_capture, th->th_getc_capture);
1969 	DB_PRINTSYM(getc_poll, th->th_getc_poll);
1970 	DB_PRINTSYM(close, th->th_close);
1971 }
1972 
1973 static void
1974 _db_show_termios(const char *name, const struct termios *t)
1975 {
1976 
1977 	db_printf("%s: iflag 0x%x oflag 0x%x cflag 0x%x "
1978 	    "lflag 0x%x ispeed %u ospeed %u\n", name,
1979 	    t->c_iflag, t->c_oflag, t->c_cflag, t->c_lflag,
1980 	    t->c_ispeed, t->c_ospeed);
1981 }
1982 
1983 /* DDB command to show TTY statistics. */
1984 DB_SHOW_COMMAND(tty, db_show_tty)
1985 {
1986 	struct tty *tp;
1987 
1988 	if (!have_addr) {
1989 		db_printf("usage: show tty <addr>\n");
1990 		return;
1991 	}
1992 	tp = (struct tty *)addr;
1993 
1994 	db_printf("0x%p: %s\n", tp, tty_devname(tp));
1995 	db_printf("\tmtx: %p\n", tp->t_mtx);
1996 	db_printf("\tflags: %b\n", tp->t_flags, TTY_FLAG_BITS);
1997 	db_printf("\trevokecnt: %u\n", tp->t_revokecnt);
1998 
1999 	/* Buffering mechanisms. */
2000 	db_printf("\tinq: %p begin %u linestart %u reprint %u end %u "
2001 	    "nblocks %u quota %u\n", &tp->t_inq, tp->t_inq.ti_begin,
2002 	    tp->t_inq.ti_linestart, tp->t_inq.ti_reprint, tp->t_inq.ti_end,
2003 	    tp->t_inq.ti_nblocks, tp->t_inq.ti_quota);
2004 	db_printf("\toutq: %p begin %u end %u nblocks %u quota %u\n",
2005 	    &tp->t_outq, tp->t_outq.to_begin, tp->t_outq.to_end,
2006 	    tp->t_outq.to_nblocks, tp->t_outq.to_quota);
2007 	db_printf("\tinlow: %zu\n", tp->t_inlow);
2008 	db_printf("\toutlow: %zu\n", tp->t_outlow);
2009 	_db_show_termios("\ttermios", &tp->t_termios);
2010 	db_printf("\twinsize: row %u col %u xpixel %u ypixel %u\n",
2011 	    tp->t_winsize.ws_row, tp->t_winsize.ws_col,
2012 	    tp->t_winsize.ws_xpixel, tp->t_winsize.ws_ypixel);
2013 	db_printf("\tcolumn: %u\n", tp->t_column);
2014 	db_printf("\twritepos: %u\n", tp->t_writepos);
2015 	db_printf("\tcompatflags: 0x%x\n", tp->t_compatflags);
2016 
2017 	/* Init/lock-state devices. */
2018 	_db_show_termios("\ttermios_init_in", &tp->t_termios_init_in);
2019 	_db_show_termios("\ttermios_init_out", &tp->t_termios_init_out);
2020 	_db_show_termios("\ttermios_lock_in", &tp->t_termios_lock_in);
2021 	_db_show_termios("\ttermios_lock_out", &tp->t_termios_lock_out);
2022 
2023 	/* Hooks */
2024 	_db_show_devsw("\t", tp->t_devsw);
2025 	_db_show_hooks("\t", tp->t_hook);
2026 
2027 	/* Process info. */
2028 	db_printf("\tpgrp: %p gid %d jobc %d\n", tp->t_pgrp,
2029 	    tp->t_pgrp ? tp->t_pgrp->pg_id : 0,
2030 	    tp->t_pgrp ? tp->t_pgrp->pg_jobc : 0);
2031 	db_printf("\tsession: %p", tp->t_session);
2032 	if (tp->t_session != NULL)
2033 	    db_printf(" count %u leader %p tty %p sid %d login %s",
2034 		tp->t_session->s_count, tp->t_session->s_leader,
2035 		tp->t_session->s_ttyp, tp->t_session->s_sid,
2036 		tp->t_session->s_login);
2037 	db_printf("\n");
2038 	db_printf("\tsessioncnt: %u\n", tp->t_sessioncnt);
2039 	db_printf("\tdevswsoftc: %p\n", tp->t_devswsoftc);
2040 	db_printf("\thooksoftc: %p\n", tp->t_hooksoftc);
2041 	db_printf("\tdev: %p\n", tp->t_dev);
2042 }
2043 
2044 /* DDB command to list TTYs. */
2045 DB_SHOW_ALL_COMMAND(ttys, db_show_all_ttys)
2046 {
2047 	struct tty *tp;
2048 	size_t isiz, osiz;
2049 	int i, j;
2050 
2051 	/* Make the output look like `pstat -t'. */
2052 	db_printf("PTR        ");
2053 #if defined(__LP64__)
2054 	db_printf("        ");
2055 #endif
2056 	db_printf("      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   "
2057 	    "COL  SESS  PGID STATE\n");
2058 
2059 	TAILQ_FOREACH(tp, &tty_list, t_list) {
2060 		isiz = tp->t_inq.ti_nblocks * TTYINQ_DATASIZE;
2061 		osiz = tp->t_outq.to_nblocks * TTYOUTQ_DATASIZE;
2062 
2063 		db_printf("%p %10s %5zu %4u %4u %4zu %5zu %4u %4zu %5u %5d %5d ",
2064 		    tp,
2065 		    tty_devname(tp),
2066 		    isiz,
2067 		    tp->t_inq.ti_linestart - tp->t_inq.ti_begin,
2068 		    tp->t_inq.ti_end - tp->t_inq.ti_linestart,
2069 		    isiz - tp->t_inlow,
2070 		    osiz,
2071 		    tp->t_outq.to_end - tp->t_outq.to_begin,
2072 		    osiz - tp->t_outlow,
2073 		    MIN(tp->t_column, 99999),
2074 		    tp->t_session ? tp->t_session->s_sid : 0,
2075 		    tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
2076 
2077 		/* Flag bits. */
2078 		for (i = j = 0; ttystates[i].flag; i++)
2079 			if (tp->t_flags & ttystates[i].flag) {
2080 				db_printf("%c", ttystates[i].val);
2081 				j++;
2082 			}
2083 		if (j == 0)
2084 			db_printf("-");
2085 		db_printf("\n");
2086 	}
2087 }
2088 #endif /* DDB */
2089