xref: /freebsd/sys/kern/tty.c (revision 52267f7411adcc76ede961420e08c0e42f42d415)
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/filio.h>
41 #ifdef COMPAT_43TTY
42 #include <sys/ioctl_compat.h>
43 #endif /* COMPAT_43TTY */
44 #include <sys/kernel.h>
45 #include <sys/limits.h>
46 #include <sys/malloc.h>
47 #include <sys/mount.h>
48 #include <sys/poll.h>
49 #include <sys/priv.h>
50 #include <sys/proc.h>
51 #include <sys/serial.h>
52 #include <sys/signal.h>
53 #include <sys/stat.h>
54 #include <sys/sx.h>
55 #include <sys/sysctl.h>
56 #include <sys/systm.h>
57 #include <sys/tty.h>
58 #include <sys/ttycom.h>
59 #define TTYDEFCHARS
60 #include <sys/ttydefaults.h>
61 #undef TTYDEFCHARS
62 #include <sys/ucred.h>
63 #include <sys/vnode.h>
64 
65 #include <machine/stdarg.h>
66 
67 static MALLOC_DEFINE(M_TTY, "tty", "tty device");
68 
69 static void tty_rel_free(struct tty *tp);
70 
71 static TAILQ_HEAD(, tty) tty_list = TAILQ_HEAD_INITIALIZER(tty_list);
72 static struct sx tty_list_sx;
73 SX_SYSINIT(tty_list, &tty_list_sx, "tty list");
74 static unsigned int tty_list_count = 0;
75 
76 /* Character device of /dev/console. */
77 static struct cdev	*dev_console;
78 static const char	*dev_console_filename;
79 
80 /*
81  * Flags that are supported and stored by this implementation.
82  */
83 #define TTYSUP_IFLAG	(IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK|ISTRIP|\
84 			INLCR|IGNCR|ICRNL|IXON|IXOFF|IXANY|IMAXBEL)
85 #define TTYSUP_OFLAG	(OPOST|ONLCR|TAB3|ONOEOT|OCRNL|ONOCR|ONLRET)
86 #define TTYSUP_LFLAG	(ECHOKE|ECHOE|ECHOK|ECHO|ECHONL|ECHOPRT|\
87 			ECHOCTL|ISIG|ICANON|ALTWERASE|IEXTEN|TOSTOP|\
88 			FLUSHO|NOKERNINFO|NOFLSH)
89 #define TTYSUP_CFLAG	(CIGNORE|CSIZE|CSTOPB|CREAD|PARENB|PARODD|\
90 			HUPCL|CLOCAL|CCTS_OFLOW|CRTS_IFLOW|CDTR_IFLOW|\
91 			CDSR_OFLOW|CCAR_OFLOW)
92 
93 #define	TTY_CALLOUT(tp,d) ((d) != (tp)->t_dev && (d) != dev_console)
94 
95 /*
96  * Set TTY buffer sizes.
97  */
98 
99 #define	TTYBUF_MAX	65536
100 
101 static void
102 tty_watermarks(struct tty *tp)
103 {
104 	size_t bs;
105 
106 	/* Provide an input buffer for 0.2 seconds of data. */
107 	bs = MIN(tp->t_termios.c_ispeed / 5, TTYBUF_MAX);
108 	ttyinq_setsize(&tp->t_inq, tp, bs);
109 
110 	/* Set low watermark at 10% (when 90% is available). */
111 	tp->t_inlow = (ttyinq_getsize(&tp->t_inq) * 9) / 10;
112 
113 	/* Provide an ouput buffer for 0.2 seconds of data. */
114 	bs = MIN(tp->t_termios.c_ospeed / 5, TTYBUF_MAX);
115 	ttyoutq_setsize(&tp->t_outq, tp, bs);
116 
117 	/* Set low watermark at 10% (when 90% is available). */
118 	tp->t_outlow = (ttyoutq_getsize(&tp->t_outq) * 9) / 10;
119 }
120 
121 static int
122 tty_drain(struct tty *tp)
123 {
124 	int error;
125 
126 	if (ttyhook_hashook(tp, getc_inject))
127 		/* buffer is inaccessible */
128 		return (0);
129 
130 	while (ttyoutq_bytesused(&tp->t_outq) > 0) {
131 		ttydevsw_outwakeup(tp);
132 		/* Could be handled synchronously. */
133 		if (ttyoutq_bytesused(&tp->t_outq) == 0)
134 			return (0);
135 
136 		/* Wait for data to be drained. */
137 		error = tty_wait(tp, &tp->t_outwait);
138 		if (error)
139 			return (error);
140 	}
141 
142 	return (0);
143 }
144 
145 /*
146  * Though ttydev_enter() and ttydev_leave() seem to be related, they
147  * don't have to be used together. ttydev_enter() is used by the cdev
148  * operations to prevent an actual operation from being processed when
149  * the TTY has been abandoned. ttydev_leave() is used by ttydev_open()
150  * and ttydev_close() to determine whether per-TTY data should be
151  * deallocated.
152  */
153 
154 static __inline int
155 ttydev_enter(struct tty *tp)
156 {
157 	tty_lock(tp);
158 
159 	if (tty_gone(tp) || !tty_opened(tp)) {
160 		/* Device is already gone. */
161 		tty_unlock(tp);
162 		return (ENXIO);
163 	}
164 
165 	return (0);
166 }
167 
168 static void
169 ttydev_leave(struct tty *tp)
170 {
171 	tty_lock_assert(tp, MA_OWNED);
172 
173 	if (tty_opened(tp) || tp->t_flags & TF_OPENCLOSE) {
174 		/* Device is still opened somewhere. */
175 		tty_unlock(tp);
176 		return;
177 	}
178 
179 	tp->t_flags |= TF_OPENCLOSE;
180 
181 	/* Stop asynchronous I/O. */
182 	funsetown(&tp->t_sigio);
183 
184 	/* Remove console TTY. */
185 	if (constty == tp)
186 		constty_clear();
187 
188 	/* Drain any output. */
189 	MPASS((tp->t_flags & TF_STOPPED) == 0);
190 	if (!tty_gone(tp))
191 		tty_drain(tp);
192 
193 	ttydisc_close(tp);
194 
195 	/* Destroy associated buffers already. */
196 	ttyinq_free(&tp->t_inq);
197 	tp->t_inlow = 0;
198 	ttyoutq_free(&tp->t_outq);
199 	tp->t_outlow = 0;
200 
201 	knlist_clear(&tp->t_inpoll.si_note, 1);
202 	knlist_clear(&tp->t_outpoll.si_note, 1);
203 
204 	if (!tty_gone(tp))
205 		ttydevsw_close(tp);
206 
207 	tp->t_flags &= ~TF_OPENCLOSE;
208 	tty_rel_free(tp);
209 }
210 
211 /*
212  * Operations that are exposed through the character device in /dev.
213  */
214 static int
215 ttydev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
216 {
217 	struct tty *tp = dev->si_drv1;
218 	int error = 0;
219 
220 	/* Disallow access when the TTY belongs to a different prison. */
221 	if (dev->si_cred != NULL &&
222 	    dev->si_cred->cr_prison != td->td_ucred->cr_prison &&
223 	    priv_check(td, PRIV_TTY_PRISON)) {
224 		return (EPERM);
225 	}
226 
227 	tty_lock(tp);
228 	if (tty_gone(tp)) {
229 		/* Device is already gone. */
230 		tty_unlock(tp);
231 		return (ENXIO);
232 	}
233 	/*
234 	 * Prevent the TTY from being opened when being torn down or
235 	 * built up by unrelated processes.
236 	 */
237 	if (tp->t_flags & TF_OPENCLOSE) {
238 		tty_unlock(tp);
239 		return (EBUSY);
240 	}
241 	tp->t_flags |= TF_OPENCLOSE;
242 
243 	/*
244 	 * Make sure the "tty" and "cua" device cannot be opened at the
245 	 * same time.
246 	 */
247 	if (TTY_CALLOUT(tp, dev)) {
248 		if (tp->t_flags & TF_OPENED_IN) {
249 			error = EBUSY;
250 			goto done;
251 		}
252 	} else {
253 		if (tp->t_flags & TF_OPENED_OUT) {
254 			error = EBUSY;
255 			goto done;
256 		}
257 	}
258 
259 	if (tp->t_flags & TF_EXCLUDE && priv_check(td, PRIV_TTY_EXCLUSIVE)) {
260 		error = EBUSY;
261 		goto done;
262 	}
263 
264 	if (!tty_opened(tp)) {
265 		/* Set proper termios flags. */
266 		if (TTY_CALLOUT(tp, dev)) {
267 			tp->t_termios = tp->t_termios_init_out;
268 		} else {
269 			tp->t_termios = tp->t_termios_init_in;
270 		}
271 		ttydevsw_param(tp, &tp->t_termios);
272 
273 		ttydevsw_modem(tp, SER_DTR|SER_RTS, 0);
274 
275 		error = ttydevsw_open(tp);
276 		if (error != 0)
277 			goto done;
278 
279 		ttydisc_open(tp);
280 		tty_watermarks(tp);
281 	}
282 
283 	/* Wait for Carrier Detect. */
284 	if (!TTY_CALLOUT(tp, dev) && (oflags & O_NONBLOCK) == 0 &&
285 	    (tp->t_termios.c_cflag & CLOCAL) == 0) {
286 		while ((ttydevsw_modem(tp, 0, 0) & SER_DCD) == 0) {
287 			error = tty_wait(tp, &tp->t_dcdwait);
288 			if (error != 0)
289 				goto done;
290 		}
291 	}
292 
293 	if (TTY_CALLOUT(tp, dev)) {
294 		tp->t_flags |= TF_OPENED_OUT;
295 	} else {
296 		tp->t_flags |= TF_OPENED_IN;
297 	}
298 
299 done:	tp->t_flags &= ~TF_OPENCLOSE;
300 	ttydev_leave(tp);
301 
302 	return (error);
303 }
304 
305 static int
306 ttydev_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
307 {
308 	struct tty *tp = dev->si_drv1;
309 
310 	tty_lock(tp);
311 
312 	/*
313 	 * This can only be called once. The callin and the callout
314 	 * devices cannot be opened at the same time.
315 	 */
316 	MPASS((tp->t_flags & TF_OPENED) != TF_OPENED);
317 	tp->t_flags &= ~(TF_OPENED|TF_EXCLUDE|TF_STOPPED);
318 
319 	/* Properly wake up threads that are stuck - revoke(). */
320 	tp->t_revokecnt++;
321 	tty_wakeup(tp, FREAD|FWRITE);
322 	cv_broadcast(&tp->t_bgwait);
323 
324 	ttydev_leave(tp);
325 
326 	return (0);
327 }
328 
329 static __inline int
330 tty_is_ctty(struct tty *tp, struct proc *p)
331 {
332 	tty_lock_assert(tp, MA_OWNED);
333 
334 	return (p->p_session == tp->t_session && p->p_flag & P_CONTROLT);
335 }
336 
337 static int
338 tty_wait_background(struct tty *tp, struct thread *td, int sig)
339 {
340 	struct proc *p = td->td_proc;
341 	struct pgrp *pg;
342 	int error;
343 
344 	MPASS(sig == SIGTTIN || sig == SIGTTOU);
345 	tty_lock_assert(tp, MA_OWNED);
346 
347 	for (;;) {
348 		PROC_LOCK(p);
349 		/*
350 		 * The process should only sleep, when:
351 		 * - This terminal is the controling terminal
352 		 * - Its process group is not the foreground process
353 		 *   group
354 		 * - The parent process isn't waiting for the child to
355 		 *   exit
356 		 * - the signal to send to the process isn't masked
357 		 */
358 		if (!tty_is_ctty(tp, p) ||
359 		    p->p_pgrp == tp->t_pgrp || p->p_flag & P_PPWAIT ||
360 		    SIGISMEMBER(p->p_sigacts->ps_sigignore, sig) ||
361 		    SIGISMEMBER(td->td_sigmask, sig)) {
362 			/* Allow the action to happen. */
363 			PROC_UNLOCK(p);
364 			return (0);
365 		}
366 
367 		/*
368 		 * Send the signal and sleep until we're the new
369 		 * foreground process group.
370 		 */
371 		pg = p->p_pgrp;
372 		PROC_UNLOCK(p);
373 		if (pg->pg_jobc == 0)
374 			return (EIO);
375 		PGRP_LOCK(pg);
376 		pgsignal(pg, sig, 1);
377 		PGRP_UNLOCK(pg);
378 
379 		error = tty_wait(tp, &tp->t_bgwait);
380 		if (error)
381 			return (error);
382 	}
383 }
384 
385 static int
386 ttydev_read(struct cdev *dev, struct uio *uio, int ioflag)
387 {
388 	struct tty *tp = dev->si_drv1;
389 	int error;
390 
391 	error = ttydev_enter(tp);
392 	if (error)
393 		goto done;
394 
395 	error = tty_wait_background(tp, curthread, SIGTTIN);
396 	if (error) {
397 		tty_unlock(tp);
398 		goto done;
399 	}
400 
401 	error = ttydisc_read(tp, uio, ioflag);
402 	tty_unlock(tp);
403 
404 	/*
405 	 * The read() call should not throw an error when the device is
406 	 * being destroyed. Silently convert it to an EOF.
407 	 */
408 done:	if (error == ENXIO)
409 		error = 0;
410 	return (error);
411 }
412 
413 static int
414 ttydev_write(struct cdev *dev, struct uio *uio, int ioflag)
415 {
416 	struct tty *tp = dev->si_drv1;
417 	int error;
418 
419 	error = ttydev_enter(tp);
420 	if (error)
421 		return (error);
422 
423 	if (tp->t_termios.c_lflag & TOSTOP) {
424 		error = tty_wait_background(tp, curthread, SIGTTOU);
425 		if (error) {
426 			tty_unlock(tp);
427 			return (error);
428 		}
429 	}
430 
431 	error = ttydisc_write(tp, uio, ioflag);
432 	tty_unlock(tp);
433 
434 	return (error);
435 }
436 
437 static int
438 ttydev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
439     struct thread *td)
440 {
441 	struct tty *tp = dev->si_drv1;
442 	int error;
443 
444 	error = ttydev_enter(tp);
445 	if (error)
446 		return (error);
447 
448 	switch (cmd) {
449 	case TIOCCBRK:
450 	case TIOCCONS:
451 	case TIOCDRAIN:
452 	case TIOCEXCL:
453 	case TIOCFLUSH:
454 	case TIOCNXCL:
455 	case TIOCSBRK:
456 	case TIOCSCTTY:
457 	case TIOCSETA:
458 	case TIOCSETAF:
459 	case TIOCSETAW:
460 	case TIOCSPGRP:
461 	case TIOCSTART:
462 	case TIOCSTAT:
463 	case TIOCSTOP:
464 	case TIOCSWINSZ:
465 #if 0
466 	case TIOCSDRAINWAIT:
467 	case TIOCSETD:
468 	case TIOCSTI:
469 #endif
470 #ifdef COMPAT_43TTY
471 	case  TIOCLBIC:
472 	case  TIOCLBIS:
473 	case  TIOCLSET:
474 	case  TIOCSETC:
475 	case OTIOCSETD:
476 	case  TIOCSETN:
477 	case  TIOCSETP:
478 	case  TIOCSLTC:
479 #endif /* COMPAT_43TTY */
480 		/*
481 		 * If the ioctl() causes the TTY to be modified, let it
482 		 * wait in the background.
483 		 */
484 		error = tty_wait_background(tp, curthread, SIGTTOU);
485 		if (error)
486 			goto done;
487 	}
488 
489 	error = tty_ioctl(tp, cmd, data, td);
490 done:	tty_unlock(tp);
491 
492 	return (error);
493 }
494 
495 static int
496 ttydev_poll(struct cdev *dev, int events, struct thread *td)
497 {
498 	struct tty *tp = dev->si_drv1;
499 	int error, revents = 0;
500 
501 	error = ttydev_enter(tp);
502 	if (error) {
503 		/* Don't return the error here, but the event mask. */
504 		return (events &
505 		    (POLLHUP|POLLIN|POLLRDNORM|POLLOUT|POLLWRNORM));
506 	}
507 
508 	if (events & (POLLIN|POLLRDNORM)) {
509 		/* See if we can read something. */
510 		if (ttydisc_read_poll(tp) > 0)
511 			revents |= events & (POLLIN|POLLRDNORM);
512 	}
513 	if (events & (POLLOUT|POLLWRNORM)) {
514 		/* See if we can write something. */
515 		if (ttydisc_write_poll(tp) > 0)
516 			revents |= events & (POLLOUT|POLLWRNORM);
517 	}
518 	if (tp->t_flags & TF_ZOMBIE)
519 		/* Hangup flag on zombie state. */
520 		revents |= events & POLLHUP;
521 
522 	if (revents == 0) {
523 		if (events & (POLLIN|POLLRDNORM))
524 			selrecord(td, &tp->t_inpoll);
525 		if (events & (POLLOUT|POLLWRNORM))
526 			selrecord(td, &tp->t_outpoll);
527 	}
528 
529 	tty_unlock(tp);
530 
531 	return (revents);
532 }
533 
534 static int
535 ttydev_mmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr, int nprot)
536 {
537 	struct tty *tp = dev->si_drv1;
538 	int error;
539 
540 	/* Handle mmap() through the driver. */
541 
542 	error = ttydev_enter(tp);
543 	if (error)
544 		return (-1);
545 	error = ttydevsw_mmap(tp, offset, paddr, nprot);
546 	tty_unlock(tp);
547 
548 	return (error);
549 }
550 
551 /*
552  * kqueue support.
553  */
554 
555 static void
556 tty_kqops_read_detach(struct knote *kn)
557 {
558 	struct tty *tp = kn->kn_hook;
559 
560 	knlist_remove(&tp->t_inpoll.si_note, kn, 0);
561 }
562 
563 static int
564 tty_kqops_read_event(struct knote *kn, long hint)
565 {
566 	struct tty *tp = kn->kn_hook;
567 
568 	tty_lock_assert(tp, MA_OWNED);
569 
570 	if (tty_gone(tp) || tp->t_flags & TF_ZOMBIE) {
571 		kn->kn_flags |= EV_EOF;
572 		return (1);
573 	} else {
574 		kn->kn_data = ttydisc_read_poll(tp);
575 		return (kn->kn_data > 0);
576 	}
577 }
578 
579 static void
580 tty_kqops_write_detach(struct knote *kn)
581 {
582 	struct tty *tp = kn->kn_hook;
583 
584 	knlist_remove(&tp->t_outpoll.si_note, kn, 0);
585 }
586 
587 static int
588 tty_kqops_write_event(struct knote *kn, long hint)
589 {
590 	struct tty *tp = kn->kn_hook;
591 
592 	tty_lock_assert(tp, MA_OWNED);
593 
594 	if (tty_gone(tp)) {
595 		kn->kn_flags |= EV_EOF;
596 		return (1);
597 	} else {
598 		kn->kn_data = ttydisc_write_poll(tp);
599 		return (kn->kn_data > 0);
600 	}
601 }
602 
603 static struct filterops tty_kqops_read =
604     { 1, NULL, tty_kqops_read_detach, tty_kqops_read_event };
605 static struct filterops tty_kqops_write =
606     { 1, NULL, tty_kqops_write_detach, tty_kqops_write_event };
607 
608 static int
609 ttydev_kqfilter(struct cdev *dev, struct knote *kn)
610 {
611 	struct tty *tp = dev->si_drv1;
612 	int error;
613 
614 	error = ttydev_enter(tp);
615 	if (error)
616 		return (error);
617 
618 	switch (kn->kn_filter) {
619 	case EVFILT_READ:
620 		kn->kn_hook = tp;
621 		kn->kn_fop = &tty_kqops_read;
622 		knlist_add(&tp->t_inpoll.si_note, kn, 1);
623 		break;
624 	case EVFILT_WRITE:
625 		kn->kn_hook = tp;
626 		kn->kn_fop = &tty_kqops_write;
627 		knlist_add(&tp->t_outpoll.si_note, kn, 1);
628 		break;
629 	default:
630 		error = EINVAL;
631 		break;
632 	}
633 
634 	tty_unlock(tp);
635 	return (error);
636 }
637 
638 static struct cdevsw ttydev_cdevsw = {
639 	.d_version	= D_VERSION,
640 	.d_open		= ttydev_open,
641 	.d_close	= ttydev_close,
642 	.d_read		= ttydev_read,
643 	.d_write	= ttydev_write,
644 	.d_ioctl	= ttydev_ioctl,
645 	.d_kqfilter	= ttydev_kqfilter,
646 	.d_poll		= ttydev_poll,
647 	.d_mmap		= ttydev_mmap,
648 	.d_name		= "ttydev",
649 	.d_flags	= D_TTY,
650 };
651 
652 /*
653  * Init/lock-state devices
654  */
655 
656 static int
657 ttyil_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
658 {
659 	struct tty *tp = dev->si_drv1;
660 	int error = 0;
661 
662 	tty_lock(tp);
663 	if (tty_gone(tp))
664 		error = ENODEV;
665 	tty_unlock(tp);
666 
667 	return (error);
668 }
669 
670 static int
671 ttyil_close(struct cdev *dev, int flag, int mode, struct thread *td)
672 {
673 	return (0);
674 }
675 
676 static int
677 ttyil_rdwr(struct cdev *dev, struct uio *uio, int ioflag)
678 {
679 	return (ENODEV);
680 }
681 
682 static int
683 ttyil_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
684     struct thread *td)
685 {
686 	struct tty *tp = dev->si_drv1;
687 	int error = 0;
688 
689 	tty_lock(tp);
690 	if (tty_gone(tp)) {
691 		error = ENODEV;
692 		goto done;
693 	}
694 
695 	switch (cmd) {
696 	case TIOCGETA:
697 		/* Obtain terminal flags through tcgetattr(). */
698 		bcopy(dev->si_drv2, data, sizeof(struct termios));
699 		break;
700 	case TIOCSETA:
701 		/* Set terminal flags through tcsetattr(). */
702 		error = priv_check(td, PRIV_TTY_SETA);
703 		if (error)
704 			break;
705 		bcopy(data, dev->si_drv2, sizeof(struct termios));
706 		break;
707 	case TIOCGETD:
708 		*(int *)data = TTYDISC;
709 		break;
710 	case TIOCGWINSZ:
711 		bzero(data, sizeof(struct winsize));
712 		break;
713 	default:
714 		error = ENOTTY;
715 	}
716 
717 done:	tty_unlock(tp);
718 	return (error);
719 }
720 
721 static struct cdevsw ttyil_cdevsw = {
722 	.d_version	= D_VERSION,
723 	.d_open		= ttyil_open,
724 	.d_close	= ttyil_close,
725 	.d_read		= ttyil_rdwr,
726 	.d_write	= ttyil_rdwr,
727 	.d_ioctl	= ttyil_ioctl,
728 	.d_name		= "ttyil",
729 	.d_flags	= D_TTY,
730 };
731 
732 static void
733 tty_init_termios(struct tty *tp)
734 {
735 	struct termios *t = &tp->t_termios_init_in;
736 
737 	t->c_cflag = TTYDEF_CFLAG;
738 	t->c_iflag = TTYDEF_IFLAG;
739 	t->c_lflag = TTYDEF_LFLAG;
740 	t->c_oflag = TTYDEF_OFLAG;
741 	t->c_ispeed = TTYDEF_SPEED;
742 	t->c_ospeed = TTYDEF_SPEED;
743 	bcopy(ttydefchars, &t->c_cc, sizeof ttydefchars);
744 
745 	tp->t_termios_init_out = *t;
746 }
747 
748 void
749 tty_init_console(struct tty *tp, speed_t s)
750 {
751 	struct termios *ti = &tp->t_termios_init_in;
752 	struct termios *to = &tp->t_termios_init_out;
753 
754 	if (s != 0) {
755 		ti->c_ispeed = ti->c_ospeed = s;
756 		to->c_ispeed = to->c_ospeed = s;
757 	}
758 
759 	ti->c_cflag |= CLOCAL;
760 	to->c_cflag |= CLOCAL;
761 }
762 
763 /*
764  * Standard device routine implementations, mostly meant for
765  * pseudo-terminal device drivers. When a driver creates a new terminal
766  * device class, missing routines are patched.
767  */
768 
769 static int
770 ttydevsw_defopen(struct tty *tp)
771 {
772 
773 	return (0);
774 }
775 
776 static void
777 ttydevsw_defclose(struct tty *tp)
778 {
779 }
780 
781 static void
782 ttydevsw_defoutwakeup(struct tty *tp)
783 {
784 
785 	panic("Terminal device has output, while not implemented");
786 }
787 
788 static void
789 ttydevsw_definwakeup(struct tty *tp)
790 {
791 }
792 
793 static int
794 ttydevsw_defioctl(struct tty *tp, u_long cmd, caddr_t data, struct thread *td)
795 {
796 
797 	return (ENOIOCTL);
798 }
799 
800 static int
801 ttydevsw_defparam(struct tty *tp, struct termios *t)
802 {
803 
804 	/* Use a fake baud rate, we're not a real device. */
805 	t->c_ispeed = t->c_ospeed = TTYDEF_SPEED;
806 
807 	return (0);
808 }
809 
810 static int
811 ttydevsw_defmodem(struct tty *tp, int sigon, int sigoff)
812 {
813 
814 	/* Simulate a carrier to make the TTY layer happy. */
815 	return (SER_DCD);
816 }
817 
818 static int
819 ttydevsw_defmmap(struct tty *tp, vm_offset_t offset, vm_paddr_t *paddr,
820     int nprot)
821 {
822 
823 	return (-1);
824 }
825 
826 static void
827 ttydevsw_defpktnotify(struct tty *tp, char event)
828 {
829 }
830 
831 static void
832 ttydevsw_deffree(void *softc)
833 {
834 
835 	panic("Terminal device freed without a free-handler");
836 }
837 
838 /*
839  * TTY allocation and deallocation. TTY devices can be deallocated when
840  * the driver doesn't use it anymore, when the TTY isn't a session's
841  * controlling TTY and when the device node isn't opened through devfs.
842  */
843 
844 struct tty *
845 tty_alloc(struct ttydevsw *tsw, void *sc, struct mtx *mutex)
846 {
847 	struct tty *tp;
848 
849 	/* Make sure the driver defines all routines. */
850 #define PATCH_FUNC(x) do {				\
851 	if (tsw->tsw_ ## x == NULL)			\
852 		tsw->tsw_ ## x = ttydevsw_def ## x;	\
853 } while (0)
854 	PATCH_FUNC(open);
855 	PATCH_FUNC(close);
856 	PATCH_FUNC(outwakeup);
857 	PATCH_FUNC(inwakeup);
858 	PATCH_FUNC(ioctl);
859 	PATCH_FUNC(param);
860 	PATCH_FUNC(modem);
861 	PATCH_FUNC(mmap);
862 	PATCH_FUNC(pktnotify);
863 	PATCH_FUNC(free);
864 #undef PATCH_FUNC
865 
866 	tp = malloc(sizeof(struct tty), M_TTY, M_WAITOK|M_ZERO);
867 	tp->t_devsw = tsw;
868 	tp->t_devswsoftc = sc;
869 	tp->t_flags = tsw->tsw_flags;
870 
871 	tty_init_termios(tp);
872 
873 	cv_init(&tp->t_inwait, "tty input");
874 	cv_init(&tp->t_outwait, "tty output");
875 	cv_init(&tp->t_bgwait, "tty background");
876 	cv_init(&tp->t_dcdwait, "tty dcd");
877 
878 	ttyinq_init(&tp->t_inq);
879 	ttyoutq_init(&tp->t_outq);
880 
881 	/* Allow drivers to use a custom mutex to lock the TTY. */
882 	if (mutex != NULL) {
883 		tp->t_mtx = mutex;
884 	} else {
885 		tp->t_mtx = &tp->t_mtxobj;
886 		mtx_init(&tp->t_mtxobj, "tty lock", NULL, MTX_DEF);
887 	}
888 
889 	knlist_init(&tp->t_inpoll.si_note, tp->t_mtx, NULL, NULL, NULL);
890 	knlist_init(&tp->t_outpoll.si_note, tp->t_mtx, NULL, NULL, NULL);
891 
892 	sx_xlock(&tty_list_sx);
893 	TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
894 	tty_list_count++;
895 	sx_xunlock(&tty_list_sx);
896 
897 	return (tp);
898 }
899 
900 static void
901 tty_dealloc(void *arg)
902 {
903 	struct tty *tp = arg;
904 
905 	sx_xlock(&tty_list_sx);
906 	TAILQ_REMOVE(&tty_list, tp, t_list);
907 	tty_list_count--;
908 	sx_xunlock(&tty_list_sx);
909 
910 	/* Make sure we haven't leaked buffers. */
911 	MPASS(ttyinq_getsize(&tp->t_inq) == 0);
912 	MPASS(ttyoutq_getsize(&tp->t_outq) == 0);
913 
914 	knlist_destroy(&tp->t_inpoll.si_note);
915 	knlist_destroy(&tp->t_outpoll.si_note);
916 
917 	cv_destroy(&tp->t_inwait);
918 	cv_destroy(&tp->t_outwait);
919 	cv_destroy(&tp->t_bgwait);
920 	cv_destroy(&tp->t_dcdwait);
921 
922 	if (tp->t_mtx == &tp->t_mtxobj)
923 		mtx_destroy(&tp->t_mtxobj);
924 	ttydevsw_free(tp);
925 	free(tp, M_TTY);
926 }
927 
928 static void
929 tty_rel_free(struct tty *tp)
930 {
931 	struct cdev *dev;
932 
933 	tty_lock_assert(tp, MA_OWNED);
934 
935 #define	TF_ACTIVITY	(TF_GONE|TF_OPENED|TF_HOOK|TF_OPENCLOSE)
936 	if (tp->t_sessioncnt != 0 || (tp->t_flags & TF_ACTIVITY) != TF_GONE) {
937 		/* TTY is still in use. */
938 		tty_unlock(tp);
939 		return;
940 	}
941 
942 	/* TTY can be deallocated. */
943 	dev = tp->t_dev;
944 	tp->t_dev = NULL;
945 	tty_unlock(tp);
946 
947 	destroy_dev_sched_cb(dev, tty_dealloc, tp);
948 }
949 
950 void
951 tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
952 {
953 	MPASS(tp->t_sessioncnt > 0);
954 	tty_lock_assert(tp, MA_OWNED);
955 
956 	if (tp->t_pgrp == pg)
957 		tp->t_pgrp = NULL;
958 
959 	tty_unlock(tp);
960 }
961 
962 void
963 tty_rel_sess(struct tty *tp, struct session *sess)
964 {
965 	MPASS(tp->t_sessioncnt > 0);
966 
967 	/* Current session has left. */
968 	if (tp->t_session == sess) {
969 		tp->t_session = NULL;
970 		MPASS(tp->t_pgrp == NULL);
971 	}
972 	tp->t_sessioncnt--;
973 	tty_rel_free(tp);
974 }
975 
976 void
977 tty_rel_gone(struct tty *tp)
978 {
979 	MPASS(!tty_gone(tp));
980 
981 	/* Simulate carrier removal. */
982 	ttydisc_modem(tp, 0);
983 
984 	/* Wake up all blocked threads. */
985 	tty_wakeup(tp, FREAD|FWRITE);
986 	cv_broadcast(&tp->t_bgwait);
987 	cv_broadcast(&tp->t_dcdwait);
988 
989 	tp->t_flags |= TF_GONE;
990 	tty_rel_free(tp);
991 }
992 
993 /*
994  * Exposing information about current TTY's through sysctl
995  */
996 
997 static void
998 tty_to_xtty(struct tty *tp, struct xtty *xt)
999 {
1000 	tty_lock_assert(tp, MA_OWNED);
1001 
1002 	xt->xt_size = sizeof(struct xtty);
1003 	xt->xt_insize = ttyinq_getsize(&tp->t_inq);
1004 	xt->xt_incc = ttyinq_bytescanonicalized(&tp->t_inq);
1005 	xt->xt_inlc = ttyinq_bytesline(&tp->t_inq);
1006 	xt->xt_inlow = tp->t_inlow;
1007 	xt->xt_outsize = ttyoutq_getsize(&tp->t_outq);
1008 	xt->xt_outcc = ttyoutq_bytesused(&tp->t_outq);
1009 	xt->xt_outlow = tp->t_outlow;
1010 	xt->xt_column = tp->t_column;
1011 	xt->xt_pgid = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
1012 	xt->xt_sid = tp->t_session ? tp->t_session->s_sid : 0;
1013 	xt->xt_flags = tp->t_flags;
1014 	xt->xt_dev = tp->t_dev ? dev2udev(tp->t_dev) : NODEV;
1015 }
1016 
1017 static int
1018 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
1019 {
1020 	unsigned long lsize;
1021 	struct xtty *xtlist, *xt;
1022 	struct tty *tp;
1023 	int error;
1024 
1025 	sx_slock(&tty_list_sx);
1026 	lsize = tty_list_count * sizeof(struct xtty);
1027 	if (lsize == 0) {
1028 		sx_sunlock(&tty_list_sx);
1029 		return (0);
1030 	}
1031 
1032 	xtlist = xt = malloc(lsize, M_TEMP, M_WAITOK);
1033 
1034 	TAILQ_FOREACH(tp, &tty_list, t_list) {
1035 		tty_lock(tp);
1036 		tty_to_xtty(tp, xt);
1037 		tty_unlock(tp);
1038 		xt++;
1039 	}
1040 	sx_sunlock(&tty_list_sx);
1041 
1042 	error = SYSCTL_OUT(req, xtlist, lsize);
1043 	free(xtlist, M_TEMP);
1044 	return (error);
1045 }
1046 
1047 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD,
1048 	0, 0, sysctl_kern_ttys, "S,xtty", "List of TTYs");
1049 
1050 /*
1051  * Device node creation. Device has been set up, now we can expose it to
1052  * the user.
1053  */
1054 
1055 void
1056 tty_makedev(struct tty *tp, struct ucred *cred, const char *fmt, ...)
1057 {
1058 	va_list ap;
1059 	struct cdev *dev;
1060 	const char *prefix = "tty";
1061 	char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
1062 	uid_t uid;
1063 	gid_t gid;
1064 	mode_t mode;
1065 
1066 	/* Remove "tty" prefix from devices like PTY's. */
1067 	if (tp->t_flags & TF_NOPREFIX)
1068 		prefix = "";
1069 
1070 	va_start(ap, fmt);
1071 	vsnrprintf(name, sizeof name, 32, fmt, ap);
1072 	va_end(ap);
1073 
1074 	if (cred == NULL) {
1075 		/* System device. */
1076 		uid = UID_ROOT;
1077 		gid = GID_WHEEL;
1078 		mode = S_IRUSR|S_IWUSR;
1079 	} else {
1080 		/* User device. */
1081 		uid = cred->cr_ruid;
1082 		gid = GID_TTY;
1083 		mode = S_IRUSR|S_IWUSR|S_IWGRP;
1084 	}
1085 
1086 	/* Master call-in device. */
1087 	dev = make_dev_cred(&ttydev_cdevsw, 0, cred,
1088 	    uid, gid, mode, "%s%s", prefix, name);
1089 	dev->si_drv1 = tp;
1090 	tp->t_dev = dev;
1091 
1092 	/* Slave call-in devices. */
1093 	if (tp->t_flags & TF_INITLOCK) {
1094 		dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1095 		    uid, gid, mode, "%s%s.init", prefix, name);
1096 		dev_depends(tp->t_dev, dev);
1097 		dev->si_drv1 = tp;
1098 		dev->si_drv2 = &tp->t_termios_init_in;
1099 
1100 		dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1101 		    uid, gid, mode, "%s%s.lock", prefix, name);
1102 		dev_depends(tp->t_dev, dev);
1103 		dev->si_drv1 = tp;
1104 		dev->si_drv2 = &tp->t_termios_lock_in;
1105 	}
1106 
1107 	/* Call-out devices. */
1108 	if (tp->t_flags & TF_CALLOUT) {
1109 		dev = make_dev_cred(&ttydev_cdevsw, 0, cred,
1110 		    UID_UUCP, GID_DIALER, 0660, "cua%s", name);
1111 		dev_depends(tp->t_dev, dev);
1112 		dev->si_drv1 = tp;
1113 
1114 		/* Slave call-out devices. */
1115 		if (tp->t_flags & TF_INITLOCK) {
1116 			dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1117 			    UID_UUCP, GID_DIALER, 0660, "cua%s.init", name);
1118 			dev_depends(tp->t_dev, dev);
1119 			dev->si_drv1 = tp;
1120 			dev->si_drv2 = &tp->t_termios_init_out;
1121 
1122 			dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1123 			    UID_UUCP, GID_DIALER, 0660, "cua%s.lock", name);
1124 			dev_depends(tp->t_dev, dev);
1125 			dev->si_drv1 = tp;
1126 			dev->si_drv2 = &tp->t_termios_lock_out;
1127 		}
1128 	}
1129 }
1130 
1131 /*
1132  * Signalling processes.
1133  */
1134 
1135 void
1136 tty_signal_sessleader(struct tty *tp, int sig)
1137 {
1138 	struct proc *p;
1139 
1140 	tty_lock_assert(tp, MA_OWNED);
1141 	MPASS(sig >= 1 && sig < NSIG);
1142 
1143 	/* Make signals start output again. */
1144 	tp->t_flags &= ~TF_STOPPED;
1145 
1146 	if (tp->t_session != NULL && tp->t_session->s_leader != NULL) {
1147 		p = tp->t_session->s_leader;
1148 		PROC_LOCK(p);
1149 		psignal(p, sig);
1150 		PROC_UNLOCK(p);
1151 	}
1152 }
1153 
1154 void
1155 tty_signal_pgrp(struct tty *tp, int sig)
1156 {
1157 	tty_lock_assert(tp, MA_OWNED);
1158 	MPASS(sig >= 1 && sig < NSIG);
1159 
1160 	/* Make signals start output again. */
1161 	tp->t_flags &= ~TF_STOPPED;
1162 
1163 	if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
1164 		tty_info(tp);
1165 	if (tp->t_pgrp != NULL) {
1166 		PGRP_LOCK(tp->t_pgrp);
1167 		pgsignal(tp->t_pgrp, sig, 1);
1168 		PGRP_UNLOCK(tp->t_pgrp);
1169 	}
1170 }
1171 
1172 void
1173 tty_wakeup(struct tty *tp, int flags)
1174 {
1175 	if (tp->t_flags & TF_ASYNC && tp->t_sigio != NULL)
1176 		pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
1177 
1178 	if (flags & FWRITE) {
1179 		cv_broadcast(&tp->t_outwait);
1180 		selwakeup(&tp->t_outpoll);
1181 		KNOTE_LOCKED(&tp->t_outpoll.si_note, 0);
1182 	}
1183 	if (flags & FREAD) {
1184 		cv_broadcast(&tp->t_inwait);
1185 		selwakeup(&tp->t_inpoll);
1186 		KNOTE_LOCKED(&tp->t_inpoll.si_note, 0);
1187 	}
1188 }
1189 
1190 int
1191 tty_wait(struct tty *tp, struct cv *cv)
1192 {
1193 	int error;
1194 	int revokecnt = tp->t_revokecnt;
1195 
1196 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1197 	MPASS(!tty_gone(tp));
1198 
1199 	error = cv_wait_sig(cv, tp->t_mtx);
1200 
1201 	/* Restart the system call when we may have been revoked. */
1202 	if (tp->t_revokecnt != revokecnt)
1203 		return (ERESTART);
1204 
1205 	/* Bail out when the device slipped away. */
1206 	if (tty_gone(tp))
1207 		return (ENXIO);
1208 
1209 	return (error);
1210 }
1211 
1212 int
1213 tty_timedwait(struct tty *tp, struct cv *cv, int hz)
1214 {
1215 	int error;
1216 	int revokecnt = tp->t_revokecnt;
1217 
1218 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1219 	MPASS(!tty_gone(tp));
1220 
1221 	error = cv_timedwait_sig(cv, tp->t_mtx, hz);
1222 
1223 	/* Restart the system call when we may have been revoked. */
1224 	if (tp->t_revokecnt != revokecnt)
1225 		return (ERESTART);
1226 
1227 	/* Bail out when the device slipped away. */
1228 	if (tty_gone(tp))
1229 		return (ENXIO);
1230 
1231 	return (error);
1232 }
1233 
1234 void
1235 tty_flush(struct tty *tp, int flags)
1236 {
1237 	if (flags & FWRITE) {
1238 		tp->t_flags &= ~TF_HIWAT_OUT;
1239 		ttyoutq_flush(&tp->t_outq);
1240 		tty_wakeup(tp, FWRITE);
1241 		ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
1242 	}
1243 	if (flags & FREAD) {
1244 		tty_hiwat_in_unblock(tp);
1245 		ttyinq_flush(&tp->t_inq);
1246 		ttydevsw_inwakeup(tp);
1247 		ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
1248 	}
1249 }
1250 
1251 static int
1252 tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, struct thread *td)
1253 {
1254 	int error;
1255 
1256 	switch (cmd) {
1257 	/*
1258 	 * Modem commands.
1259 	 * The SER_* and TIOCM_* flags are the same, but one bit
1260 	 * shifted. I don't know why.
1261 	 */
1262 	case TIOCSDTR:
1263 		ttydevsw_modem(tp, SER_DTR, 0);
1264 		return (0);
1265 	case TIOCCDTR:
1266 		ttydevsw_modem(tp, 0, SER_DTR);
1267 		return (0);
1268 	case TIOCMSET: {
1269 		int bits = *(int *)data;
1270 		ttydevsw_modem(tp,
1271 		    (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1,
1272 		    ((~bits) & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1273 		return (0);
1274 	}
1275 	case TIOCMBIS: {
1276 		int bits = *(int *)data;
1277 		ttydevsw_modem(tp, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1, 0);
1278 		return (0);
1279 	}
1280 	case TIOCMBIC: {
1281 		int bits = *(int *)data;
1282 		ttydevsw_modem(tp, 0, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1283 		return (0);
1284 	}
1285 	case TIOCMGET:
1286 		*(int *)data = TIOCM_LE + (ttydevsw_modem(tp, 0, 0) << 1);
1287 		return (0);
1288 
1289 	case FIOASYNC:
1290 		if (*(int *)data)
1291 			tp->t_flags |= TF_ASYNC;
1292 		else
1293 			tp->t_flags &= ~TF_ASYNC;
1294 		return (0);
1295 	case FIONBIO:
1296 		/* This device supports non-blocking operation. */
1297 		return (0);
1298 	case FIONREAD:
1299 		*(int *)data = ttyinq_bytescanonicalized(&tp->t_inq);
1300 		return (0);
1301 	case FIOSETOWN:
1302 		if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1303 			/* Not allowed to set ownership. */
1304 			return (ENOTTY);
1305 
1306 		/* Temporarily unlock the TTY to set ownership. */
1307 		tty_unlock(tp);
1308 		error = fsetown(*(int *)data, &tp->t_sigio);
1309 		tty_lock(tp);
1310 		return (error);
1311 	case FIOGETOWN:
1312 		if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1313 			/* Not allowed to set ownership. */
1314 			return (ENOTTY);
1315 
1316 		/* Get ownership. */
1317 		*(int *)data = fgetown(&tp->t_sigio);
1318 		return (0);
1319 	case TIOCGETA:
1320 		/* Obtain terminal flags through tcgetattr(). */
1321 		bcopy(&tp->t_termios, data, sizeof(struct termios));
1322 		return (0);
1323 	case TIOCSETA:
1324 	case TIOCSETAW:
1325 	case TIOCSETAF: {
1326 		struct termios *t = data;
1327 
1328 		/*
1329 		 * Who makes up these funny rules? According to POSIX,
1330 		 * input baud rate is set equal to the output baud rate
1331 		 * when zero.
1332 		 */
1333 		if (t->c_ispeed == 0)
1334 			t->c_ispeed = t->c_ospeed;
1335 
1336 		/* Discard any unsupported bits. */
1337 		t->c_iflag &= TTYSUP_IFLAG;
1338 		t->c_oflag &= TTYSUP_OFLAG;
1339 		t->c_lflag &= TTYSUP_LFLAG;
1340 		t->c_cflag &= TTYSUP_CFLAG;
1341 
1342 		/* Set terminal flags through tcsetattr(). */
1343 		if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
1344 			error = tty_drain(tp);
1345 			if (error)
1346 				return (error);
1347 			if (cmd == TIOCSETAF)
1348 				tty_flush(tp, FREAD);
1349 		}
1350 
1351 		/*
1352 		 * Only call param() when the flags really change.
1353 		 */
1354 		if ((t->c_cflag & CIGNORE) == 0 &&
1355 		    (tp->t_termios.c_cflag != t->c_cflag ||
1356 		    tp->t_termios.c_ispeed != t->c_ispeed ||
1357 		    tp->t_termios.c_ospeed != t->c_ospeed)) {
1358 			error = ttydevsw_param(tp, t);
1359 			if (error)
1360 				return (error);
1361 
1362 			/* XXX: CLOCAL? */
1363 
1364 			tp->t_termios.c_cflag = t->c_cflag & ~CIGNORE;
1365 			tp->t_termios.c_ispeed = t->c_ispeed;
1366 			tp->t_termios.c_ospeed = t->c_ospeed;
1367 
1368 			/* Baud rate has changed - update watermarks. */
1369 			tty_watermarks(tp);
1370 		}
1371 
1372 		/* Copy new non-device driver parameters. */
1373 		tp->t_termios.c_iflag = t->c_iflag;
1374 		tp->t_termios.c_oflag = t->c_oflag;
1375 		tp->t_termios.c_lflag = t->c_lflag;
1376 		bcopy(t->c_cc, &tp->t_termios.c_cc, sizeof(t->c_cc));
1377 
1378 		ttydisc_optimize(tp);
1379 
1380 		if ((t->c_lflag & ICANON) == 0) {
1381 			/*
1382 			 * When in non-canonical mode, wake up all
1383 			 * readers. Canonicalize any partial input. VMIN
1384 			 * and VTIME could also be adjusted.
1385 			 */
1386 			ttyinq_canonicalize(&tp->t_inq);
1387 			tty_wakeup(tp, FREAD);
1388 		}
1389 
1390 		/*
1391 		 * For packet mode: notify the PTY consumer that VSTOP
1392 		 * and VSTART may have been changed.
1393 		 */
1394 		if (tp->t_termios.c_iflag & IXON &&
1395 		    tp->t_termios.c_cc[VSTOP] == CTRL('S') &&
1396 		    tp->t_termios.c_cc[VSTART] == CTRL('Q'))
1397 			ttydevsw_pktnotify(tp, TIOCPKT_DOSTOP);
1398 		else
1399 			ttydevsw_pktnotify(tp, TIOCPKT_NOSTOP);
1400 		return (0);
1401 	}
1402 	case TIOCGETD:
1403 		/* For compatibility - we only support TTYDISC. */
1404 		*(int *)data = TTYDISC;
1405 		return (0);
1406 	case TIOCGPGRP:
1407 		if (!tty_is_ctty(tp, td->td_proc))
1408 			return (ENOTTY);
1409 
1410 		if (tp->t_pgrp != NULL)
1411 			*(int *)data = tp->t_pgrp->pg_id;
1412 		else
1413 			*(int *)data = NO_PID;
1414 		return (0);
1415 	case TIOCGSID:
1416 		if (!tty_is_ctty(tp, td->td_proc))
1417 			return (ENOTTY);
1418 
1419 		MPASS(tp->t_session);
1420 		*(int *)data = tp->t_session->s_sid;
1421 		return (0);
1422 	case TIOCSCTTY: {
1423 		struct proc *p = td->td_proc;
1424 
1425 		/* XXX: This looks awful. */
1426 		tty_unlock(tp);
1427 		sx_xlock(&proctree_lock);
1428 		tty_lock(tp);
1429 
1430 		if (!SESS_LEADER(p)) {
1431 			/* Only the session leader may do this. */
1432 			sx_xunlock(&proctree_lock);
1433 			return (EPERM);
1434 		}
1435 
1436 		if (tp->t_session != NULL && tp->t_session == p->p_session) {
1437 			/* This is already our controlling TTY. */
1438 			sx_xunlock(&proctree_lock);
1439 			return (0);
1440 		}
1441 
1442 		if (!SESS_LEADER(p) || p->p_session->s_ttyvp != NULL ||
1443 		    (tp->t_session != NULL && tp->t_session->s_ttyvp != NULL)) {
1444 			/*
1445 			 * There is already a relation between a TTY and
1446 			 * a session, or the caller is not the session
1447 			 * leader.
1448 			 *
1449 			 * Allow the TTY to be stolen when the vnode is
1450 			 * NULL, but the reference to the TTY is still
1451 			 * active.
1452 			 */
1453 			sx_xunlock(&proctree_lock);
1454 			return (EPERM);
1455 		}
1456 
1457 		/* Connect the session to the TTY. */
1458 		tp->t_session = p->p_session;
1459 		tp->t_session->s_ttyp = tp;
1460 		tp->t_sessioncnt++;
1461 		sx_xunlock(&proctree_lock);
1462 
1463 		/* Assign foreground process group. */
1464 		tp->t_pgrp = p->p_pgrp;
1465 		PROC_LOCK(p);
1466 		p->p_flag |= P_CONTROLT;
1467 		PROC_UNLOCK(p);
1468 
1469 		return (0);
1470 	}
1471 	case TIOCSPGRP: {
1472 		struct pgrp *pg;
1473 
1474 		/*
1475 		 * XXX: Temporarily unlock the TTY to locate the process
1476 		 * group. This code would be lot nicer if we would ever
1477 		 * decompose proctree_lock.
1478 		 */
1479 		tty_unlock(tp);
1480 		sx_slock(&proctree_lock);
1481 		pg = pgfind(*(int *)data);
1482 		if (pg != NULL)
1483 			PGRP_UNLOCK(pg);
1484 		if (pg == NULL || pg->pg_session != td->td_proc->p_session) {
1485 			sx_sunlock(&proctree_lock);
1486 			tty_lock(tp);
1487 			return (EPERM);
1488 		}
1489 		tty_lock(tp);
1490 
1491 		/*
1492 		 * Determine if this TTY is the controlling TTY after
1493 		 * relocking the TTY.
1494 		 */
1495 		if (!tty_is_ctty(tp, td->td_proc)) {
1496 			sx_sunlock(&proctree_lock);
1497 			return (ENOTTY);
1498 		}
1499 		tp->t_pgrp = pg;
1500 		sx_sunlock(&proctree_lock);
1501 
1502 		/* Wake up the background process groups. */
1503 		cv_broadcast(&tp->t_bgwait);
1504 		return (0);
1505 	}
1506 	case TIOCFLUSH: {
1507 		int flags = *(int *)data;
1508 
1509 		if (flags == 0)
1510 			flags = (FREAD|FWRITE);
1511 		else
1512 			flags &= (FREAD|FWRITE);
1513 		tty_flush(tp, flags);
1514 		return (0);
1515 	}
1516 	case TIOCDRAIN:
1517 		/* Drain TTY output. */
1518 		return tty_drain(tp);
1519 	case TIOCCONS:
1520 		/* Set terminal as console TTY. */
1521 		if (*(int *)data) {
1522 			error = priv_check(td, PRIV_TTY_CONSOLE);
1523 			if (error)
1524 				return (error);
1525 
1526 			/*
1527 			 * XXX: constty should really need to be locked!
1528 			 * XXX: allow disconnected constty's to be stolen!
1529 			 */
1530 
1531 			if (constty == tp)
1532 				return (0);
1533 			if (constty != NULL)
1534 				return (EBUSY);
1535 
1536 			tty_unlock(tp);
1537 			constty_set(tp);
1538 			tty_lock(tp);
1539 		} else if (constty == tp) {
1540 			constty_clear();
1541 		}
1542 		return (0);
1543 	case TIOCGWINSZ:
1544 		/* Obtain window size. */
1545 		bcopy(&tp->t_winsize, data, sizeof(struct winsize));
1546 		return (0);
1547 	case TIOCSWINSZ:
1548 		/* Set window size. */
1549 		if (bcmp(&tp->t_winsize, data, sizeof(struct winsize)) == 0)
1550 			return (0);
1551 		bcopy(data, &tp->t_winsize, sizeof(struct winsize));
1552 		tty_signal_pgrp(tp, SIGWINCH);
1553 		return (0);
1554 	case TIOCEXCL:
1555 		tp->t_flags |= TF_EXCLUDE;
1556 		return (0);
1557 	case TIOCNXCL:
1558 		tp->t_flags &= ~TF_EXCLUDE;
1559 		return (0);
1560 	case TIOCOUTQ:
1561 		*(unsigned int *)data = ttyoutq_bytesused(&tp->t_outq);
1562 		return (0);
1563 	case TIOCSTOP:
1564 		tp->t_flags |= TF_STOPPED;
1565 		ttydevsw_pktnotify(tp, TIOCPKT_STOP);
1566 		return (0);
1567 	case TIOCSTART:
1568 		tp->t_flags &= ~TF_STOPPED;
1569 		ttydevsw_outwakeup(tp);
1570 		ttydevsw_pktnotify(tp, TIOCPKT_START);
1571 		return (0);
1572 	case TIOCSTAT:
1573 		tty_info(tp);
1574 		return (0);
1575 	}
1576 
1577 #ifdef COMPAT_43TTY
1578 	return tty_ioctl_compat(tp, cmd, data, td);
1579 #else /* !COMPAT_43TTY */
1580 	return (ENOIOCTL);
1581 #endif /* COMPAT_43TTY */
1582 }
1583 
1584 int
1585 tty_ioctl(struct tty *tp, u_long cmd, void *data, struct thread *td)
1586 {
1587 	int error;
1588 
1589 	tty_lock_assert(tp, MA_OWNED);
1590 
1591 	if (tty_gone(tp))
1592 		return (ENXIO);
1593 
1594 	error = ttydevsw_ioctl(tp, cmd, data, td);
1595 	if (error == ENOIOCTL)
1596 		error = tty_generic_ioctl(tp, cmd, data, td);
1597 
1598 	return (error);
1599 }
1600 
1601 dev_t
1602 tty_udev(struct tty *tp)
1603 {
1604 	if (tp->t_dev)
1605 		return dev2udev(tp->t_dev);
1606 	else
1607 		return NODEV;
1608 }
1609 
1610 int
1611 tty_checkoutq(struct tty *tp)
1612 {
1613 
1614 	/* 256 bytes should be enough to print a log message. */
1615 	return (ttyoutq_bytesleft(&tp->t_outq) >= 256);
1616 }
1617 
1618 void
1619 tty_hiwat_in_block(struct tty *tp)
1620 {
1621 
1622 	if ((tp->t_flags & TF_HIWAT_IN) == 0 &&
1623 	    tp->t_termios.c_iflag & IXOFF &&
1624 	    tp->t_termios.c_cc[VSTOP] != _POSIX_VDISABLE) {
1625 		/*
1626 		 * Input flow control. Only enter the high watermark when we
1627 		 * can successfully store the VSTOP character.
1628 		 */
1629 		if (ttyoutq_write_nofrag(&tp->t_outq,
1630 		    &tp->t_termios.c_cc[VSTOP], 1) == 0)
1631 			tp->t_flags |= TF_HIWAT_IN;
1632 	} else {
1633 		/* No input flow control. */
1634 		tp->t_flags |= TF_HIWAT_IN;
1635 	}
1636 }
1637 
1638 void
1639 tty_hiwat_in_unblock(struct tty *tp)
1640 {
1641 
1642 	if (tp->t_flags & TF_HIWAT_IN &&
1643 	    tp->t_termios.c_iflag & IXOFF &&
1644 	    tp->t_termios.c_cc[VSTART] != _POSIX_VDISABLE) {
1645 		/*
1646 		 * Input flow control. Only leave the high watermark when we
1647 		 * can successfully store the VSTART character.
1648 		 */
1649 		if (ttyoutq_write_nofrag(&tp->t_outq,
1650 		    &tp->t_termios.c_cc[VSTART], 1) == 0)
1651 			tp->t_flags &= ~TF_HIWAT_IN;
1652 	} else {
1653 		/* No input flow control. */
1654 		tp->t_flags &= ~TF_HIWAT_IN;
1655 	}
1656 
1657 	if (!tty_gone(tp))
1658 		ttydevsw_inwakeup(tp);
1659 }
1660 
1661 /*
1662  * TTY hooks interface.
1663  */
1664 
1665 static int
1666 ttyhook_defrint(struct tty *tp, char c, int flags)
1667 {
1668 
1669 	if (ttyhook_rint_bypass(tp, &c, 1) != 1)
1670 		return (-1);
1671 
1672 	return (0);
1673 }
1674 
1675 int
1676 ttyhook_register(struct tty **rtp, struct thread *td, int fd,
1677     struct ttyhook *th, void *softc)
1678 {
1679 	struct tty *tp;
1680 	struct file *fp;
1681 	struct cdev *dev;
1682 	struct cdevsw *cdp;
1683 	int error;
1684 
1685 	/* Validate the file descriptor. */
1686 	if (fget(td, fd, &fp) != 0)
1687 		return (EINVAL);
1688 
1689 	/* Make sure the vnode is bound to a character device. */
1690 	error = EINVAL;
1691 	if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR ||
1692 	    fp->f_vnode->v_rdev == NULL)
1693 		goto done1;
1694 	dev = fp->f_vnode->v_rdev;
1695 
1696 	/* Make sure it is a TTY. */
1697 	cdp = dev_refthread(dev);
1698 	if (cdp == NULL)
1699 		goto done1;
1700 	if (cdp != &ttydev_cdevsw)
1701 		goto done2;
1702 	tp = dev->si_drv1;
1703 
1704 	/* Try to attach the hook to the TTY. */
1705 	error = EBUSY;
1706 	tty_lock(tp);
1707 	MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
1708 	if (tp->t_flags & TF_HOOK)
1709 		goto done3;
1710 
1711 	tp->t_flags |= TF_HOOK;
1712 	tp->t_hook = th;
1713 	tp->t_hooksoftc = softc;
1714 	*rtp = tp;
1715 	error = 0;
1716 
1717 	/* Maybe we can switch into bypass mode now. */
1718 	ttydisc_optimize(tp);
1719 
1720 	/* Silently convert rint() calls to rint_bypass() when possible. */
1721 	if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
1722 		th->th_rint = ttyhook_defrint;
1723 
1724 done3:	tty_unlock(tp);
1725 done2:	dev_relthread(dev);
1726 done1:	fdrop(fp, td);
1727 	return (error);
1728 }
1729 
1730 void
1731 ttyhook_unregister(struct tty *tp)
1732 {
1733 
1734 	tty_lock_assert(tp, MA_OWNED);
1735 	MPASS(tp->t_flags & TF_HOOK);
1736 
1737 	/* Disconnect the hook. */
1738 	tp->t_flags &= ~TF_HOOK;
1739 	tp->t_hook = NULL;
1740 
1741 	/* Maybe we need to leave bypass mode. */
1742 	ttydisc_optimize(tp);
1743 
1744 	/* Maybe deallocate the TTY as well. */
1745 	tty_rel_free(tp);
1746 }
1747 
1748 /*
1749  * /dev/console handling.
1750  */
1751 
1752 static int
1753 ttyconsdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
1754 {
1755 	struct tty *tp;
1756 
1757 	/* System has no console device. */
1758 	if (dev_console_filename == NULL)
1759 		return (ENXIO);
1760 
1761 	/* Look up corresponding TTY by device name. */
1762 	sx_slock(&tty_list_sx);
1763 	TAILQ_FOREACH(tp, &tty_list, t_list) {
1764 		if (strcmp(dev_console_filename, tty_devname(tp)) == 0) {
1765 			dev_console->si_drv1 = tp;
1766 			break;
1767 		}
1768 	}
1769 	sx_sunlock(&tty_list_sx);
1770 
1771 	/* System console has no TTY associated. */
1772 	if (dev_console->si_drv1 == NULL)
1773 		return (ENXIO);
1774 
1775 	return (ttydev_open(dev, oflags, devtype, td));
1776 }
1777 
1778 static int
1779 ttyconsdev_write(struct cdev *dev, struct uio *uio, int ioflag)
1780 {
1781 
1782 	log_console(uio);
1783 
1784 	return (ttydev_write(dev, uio, ioflag));
1785 }
1786 
1787 /*
1788  * /dev/console is a little different than normal TTY's. Unlike regular
1789  * TTY device nodes, this device node will not revoke the entire TTY
1790  * upon closure and all data written to it will be logged.
1791  */
1792 static struct cdevsw ttyconsdev_cdevsw = {
1793 	.d_version	= D_VERSION,
1794 	.d_open		= ttyconsdev_open,
1795 	.d_read		= ttydev_read,
1796 	.d_write	= ttyconsdev_write,
1797 	.d_ioctl	= ttydev_ioctl,
1798 	.d_kqfilter	= ttydev_kqfilter,
1799 	.d_poll		= ttydev_poll,
1800 	.d_mmap		= ttydev_mmap,
1801 	.d_name		= "ttyconsdev",
1802 	.d_flags	= D_TTY,
1803 };
1804 
1805 static void
1806 ttyconsdev_init(void *unused)
1807 {
1808 
1809 	dev_console = make_dev(&ttyconsdev_cdevsw, 0, UID_ROOT, GID_WHEEL,
1810 	    0600, "console");
1811 }
1812 
1813 SYSINIT(tty, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyconsdev_init, NULL);
1814 
1815 void
1816 ttyconsdev_select(const char *name)
1817 {
1818 
1819 	dev_console_filename = name;
1820 }
1821 
1822 /*
1823  * Debugging routines.
1824  */
1825 
1826 #include "opt_ddb.h"
1827 #ifdef DDB
1828 #include <ddb/ddb.h>
1829 #include <ddb/db_sym.h>
1830 
1831 static struct {
1832 	int flag;
1833 	char val;
1834 } ttystates[] = {
1835 #if 0
1836 	{ TF_NOPREFIX,	'N' },
1837 #endif
1838 	{ TF_INITLOCK,	'I' },
1839 	{ TF_CALLOUT,	'C' },
1840 
1841 	/* Keep these together -> 'Oi' and 'Oo'. */
1842 	{ TF_OPENED,	'O' },
1843 	{ TF_OPENED_IN,	'i' },
1844 	{ TF_OPENED_OUT,'o' },
1845 
1846 	{ TF_GONE,	'G' },
1847 	{ TF_OPENCLOSE,	'B' },
1848 	{ TF_ASYNC,	'Y' },
1849 	{ TF_LITERAL,	'L' },
1850 
1851 	/* Keep these together -> 'Hi' and 'Ho'. */
1852 	{ TF_HIWAT,	'H' },
1853 	{ TF_HIWAT_IN,	'i' },
1854 	{ TF_HIWAT_OUT,	'o' },
1855 
1856 	{ TF_STOPPED,	'S' },
1857 	{ TF_EXCLUDE,	'X' },
1858 	{ TF_BYPASS,	'l' },
1859 	{ TF_ZOMBIE,	'Z' },
1860 	{ TF_HOOK,	's' },
1861 
1862 	{ 0,	       '\0' },
1863 };
1864 
1865 #define	TTY_FLAG_BITS \
1866 	"\20\1NOPREFIX\2INITLOCK\3CALLOUT\4OPENED_IN\5OPENED_OUT\6GONE" \
1867 	"\7OPENCLOSE\10ASYNC\11LITERAL\12HIWAT_IN\13HIWAT_OUT\14STOPPED" \
1868 	"\15EXCLUDE\16BYPASS\17ZOMBIE\20HOOK"
1869 
1870 #define DB_PRINTSYM(name, addr) \
1871 	db_printf("%s  " #name ": ", sep); \
1872 	db_printsym((db_addr_t) addr, DB_STGY_ANY); \
1873 	db_printf("\n");
1874 
1875 static void
1876 _db_show_devsw(const char *sep, const struct ttydevsw *tsw)
1877 {
1878 	db_printf("%sdevsw: ", sep);
1879 	db_printsym((db_addr_t)tsw, DB_STGY_ANY);
1880 	db_printf(" (%p)\n", tsw);
1881 	DB_PRINTSYM(open, tsw->tsw_open);
1882 	DB_PRINTSYM(close, tsw->tsw_close);
1883 	DB_PRINTSYM(outwakeup, tsw->tsw_outwakeup);
1884 	DB_PRINTSYM(inwakeup, tsw->tsw_inwakeup);
1885 	DB_PRINTSYM(ioctl, tsw->tsw_ioctl);
1886 	DB_PRINTSYM(param, tsw->tsw_param);
1887 	DB_PRINTSYM(modem, tsw->tsw_modem);
1888 	DB_PRINTSYM(mmap, tsw->tsw_mmap);
1889 	DB_PRINTSYM(pktnotify, tsw->tsw_pktnotify);
1890 	DB_PRINTSYM(free, tsw->tsw_free);
1891 }
1892 static void
1893 _db_show_hooks(const char *sep, const struct ttyhook *th)
1894 {
1895 	db_printf("%shook: ", sep);
1896 	db_printsym((db_addr_t)th, DB_STGY_ANY);
1897 	db_printf(" (%p)\n", th);
1898 	if (th == NULL)
1899 		return;
1900 	DB_PRINTSYM(rint, th->th_rint);
1901 	DB_PRINTSYM(rint_bypass, th->th_rint_bypass);
1902 	DB_PRINTSYM(rint_done, th->th_rint_done);
1903 	DB_PRINTSYM(rint_poll, th->th_rint_poll);
1904 	DB_PRINTSYM(getc_inject, th->th_getc_inject);
1905 	DB_PRINTSYM(getc_capture, th->th_getc_capture);
1906 	DB_PRINTSYM(getc_poll, th->th_getc_poll);
1907 	DB_PRINTSYM(close, th->th_close);
1908 }
1909 
1910 static void
1911 _db_show_termios(const char *name, const struct termios *t)
1912 {
1913 
1914 	db_printf("%s: iflag 0x%x oflag 0x%x cflag 0x%x "
1915 	    "lflag 0x%x ispeed %u ospeed %u\n", name,
1916 	    t->c_iflag, t->c_oflag, t->c_cflag, t->c_lflag,
1917 	    t->c_ispeed, t->c_ospeed);
1918 }
1919 
1920 /* DDB command to show TTY statistics. */
1921 DB_SHOW_COMMAND(tty, db_show_tty)
1922 {
1923 	struct tty *tp;
1924 
1925 	if (!have_addr) {
1926 		db_printf("usage: show tty <addr>\n");
1927 		return;
1928 	}
1929 	tp = (struct tty *)addr;
1930 
1931 	db_printf("0x%p: %s\n", tp, tty_devname(tp));
1932 	db_printf("\tmtx: %p\n", tp->t_mtx);
1933 	db_printf("\tflags: %b\n", tp->t_flags, TTY_FLAG_BITS);
1934 	db_printf("\trevokecnt: %u\n", tp->t_revokecnt);
1935 
1936 	/* Buffering mechanisms. */
1937 	db_printf("\tinq: %p begin %u linestart %u reprint %u end %u "
1938 	    "nblocks %u quota %u\n", &tp->t_inq, tp->t_inq.ti_begin,
1939 	    tp->t_inq.ti_linestart, tp->t_inq.ti_reprint, tp->t_inq.ti_end,
1940 	    tp->t_inq.ti_nblocks, tp->t_inq.ti_quota);
1941 	db_printf("\toutq: %p begin %u end %u nblocks %u quota %u\n",
1942 	    &tp->t_outq, tp->t_outq.to_begin, tp->t_outq.to_end,
1943 	    tp->t_outq.to_nblocks, tp->t_outq.to_quota);
1944 	db_printf("\tinlow: %zu\n", tp->t_inlow);
1945 	db_printf("\toutlow: %zu\n", tp->t_outlow);
1946 	_db_show_termios("\ttermios", &tp->t_termios);
1947 	db_printf("\twinsize: row %u col %u xpixel %u ypixel %u\n",
1948 	    tp->t_winsize.ws_row, tp->t_winsize.ws_col,
1949 	    tp->t_winsize.ws_xpixel, tp->t_winsize.ws_ypixel);
1950 	db_printf("\tcolumn: %u\n", tp->t_column);
1951 	db_printf("\twritepos: %u\n", tp->t_writepos);
1952 	db_printf("\tcompatflags: 0x%x\n", tp->t_compatflags);
1953 
1954 	/* Init/lock-state devices. */
1955 	_db_show_termios("\ttermios_init_in", &tp->t_termios_init_in);
1956 	_db_show_termios("\ttermios_init_out", &tp->t_termios_init_out);
1957 	_db_show_termios("\ttermios_lock_in", &tp->t_termios_lock_in);
1958 	_db_show_termios("\ttermios_lock_out", &tp->t_termios_lock_out);
1959 
1960 	/* Hooks */
1961 	_db_show_devsw("\t", tp->t_devsw);
1962 	_db_show_hooks("\t", tp->t_hook);
1963 
1964 	/* Process info. */
1965 	db_printf("\tpgrp: %p gid %d jobc %d\n", tp->t_pgrp,
1966 	    tp->t_pgrp ? tp->t_pgrp->pg_id : 0,
1967 	    tp->t_pgrp ? tp->t_pgrp->pg_jobc : 0);
1968 	db_printf("\tsession: %p", tp->t_session);
1969 	if (tp->t_session != NULL)
1970 	    db_printf(" count %u leader %p tty %p sid %d login %s",
1971 		tp->t_session->s_count, tp->t_session->s_leader,
1972 		tp->t_session->s_ttyp, tp->t_session->s_sid,
1973 		tp->t_session->s_login);
1974 	db_printf("\n");
1975 	db_printf("\tsessioncnt: %u\n", tp->t_sessioncnt);
1976 	db_printf("\tdevswsoftc: %p\n", tp->t_devswsoftc);
1977 	db_printf("\thooksoftc: %p\n", tp->t_hooksoftc);
1978 	db_printf("\tdev: %p\n", tp->t_dev);
1979 }
1980 
1981 /* DDB command to list TTYs. */
1982 DB_SHOW_ALL_COMMAND(ttys, db_show_all_ttys)
1983 {
1984 	struct tty *tp;
1985 	size_t isiz, osiz;
1986 	int i, j;
1987 
1988 	/* Make the output look like `pstat -t'. */
1989 	db_printf("PTR        ");
1990 #if defined(__LP64__)
1991 	db_printf("        ");
1992 #endif
1993 	db_printf("      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   "
1994 	    "COL  SESS  PGID STATE\n");
1995 
1996 	TAILQ_FOREACH(tp, &tty_list, t_list) {
1997 		isiz = tp->t_inq.ti_nblocks * TTYINQ_DATASIZE;
1998 		osiz = tp->t_outq.to_nblocks * TTYOUTQ_DATASIZE;
1999 
2000 		db_printf("%p %10s %5zu %4u %4u %4zu %5zu %4u %4zu %5u %5d %5d ",
2001 		    tp,
2002 		    tty_devname(tp),
2003 		    isiz,
2004 		    tp->t_inq.ti_linestart - tp->t_inq.ti_begin,
2005 		    tp->t_inq.ti_end - tp->t_inq.ti_linestart,
2006 		    isiz - tp->t_inlow,
2007 		    osiz,
2008 		    tp->t_outq.to_end - tp->t_outq.to_begin,
2009 		    osiz - tp->t_outlow,
2010 		    MIN(tp->t_column, 99999),
2011 		    tp->t_session ? tp->t_session->s_sid : 0,
2012 		    tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
2013 
2014 		/* Flag bits. */
2015 		for (i = j = 0; ttystates[i].flag; i++)
2016 			if (tp->t_flags & ttystates[i].flag) {
2017 				db_printf("%c", ttystates[i].val);
2018 				j++;
2019 			}
2020 		if (j == 0)
2021 			db_printf("-");
2022 		db_printf("\n");
2023 	}
2024 }
2025 #endif /* DDB */
2026