xref: /freebsd/sys/kern/tty.c (revision 830940567b49bb0c08dfaed40418999e76616909)
1 /*-
2  * Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Portions of this software were developed under sponsorship from Snow
6  * B.V., the Netherlands.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include "opt_compat.h"
34 
35 #include <sys/param.h>
36 #include <sys/conf.h>
37 #include <sys/cons.h>
38 #include <sys/fcntl.h>
39 #include <sys/file.h>
40 #include <sys/filedesc.h>
41 #include <sys/filio.h>
42 #ifdef COMPAT_43TTY
43 #include <sys/ioctl_compat.h>
44 #endif /* COMPAT_43TTY */
45 #include <sys/kernel.h>
46 #include <sys/limits.h>
47 #include <sys/malloc.h>
48 #include <sys/mount.h>
49 #include <sys/poll.h>
50 #include <sys/priv.h>
51 #include <sys/proc.h>
52 #include <sys/serial.h>
53 #include <sys/signal.h>
54 #include <sys/stat.h>
55 #include <sys/sx.h>
56 #include <sys/sysctl.h>
57 #include <sys/systm.h>
58 #include <sys/tty.h>
59 #include <sys/ttycom.h>
60 #define TTYDEFCHARS
61 #include <sys/ttydefaults.h>
62 #undef TTYDEFCHARS
63 #include <sys/ucred.h>
64 #include <sys/vnode.h>
65 
66 #include <machine/stdarg.h>
67 
68 static MALLOC_DEFINE(M_TTY, "tty", "tty device");
69 
70 static void tty_rel_free(struct tty *tp);
71 
72 static TAILQ_HEAD(, tty) tty_list = TAILQ_HEAD_INITIALIZER(tty_list);
73 static struct sx tty_list_sx;
74 SX_SYSINIT(tty_list, &tty_list_sx, "tty list");
75 static unsigned int tty_list_count = 0;
76 
77 /* Character device of /dev/console. */
78 static struct cdev	*dev_console;
79 static const char	*dev_console_filename;
80 
81 /*
82  * Flags that are supported and stored by this implementation.
83  */
84 #define TTYSUP_IFLAG	(IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK|ISTRIP|\
85 			INLCR|IGNCR|ICRNL|IXON|IXOFF|IXANY|IMAXBEL)
86 #define TTYSUP_OFLAG	(OPOST|ONLCR|TAB3|ONOEOT|OCRNL|ONOCR|ONLRET)
87 #define TTYSUP_LFLAG	(ECHOKE|ECHOE|ECHOK|ECHO|ECHONL|ECHOPRT|\
88 			ECHOCTL|ISIG|ICANON|ALTWERASE|IEXTEN|TOSTOP|\
89 			FLUSHO|NOKERNINFO|NOFLSH)
90 #define TTYSUP_CFLAG	(CIGNORE|CSIZE|CSTOPB|CREAD|PARENB|PARODD|\
91 			HUPCL|CLOCAL|CCTS_OFLOW|CRTS_IFLOW|CDTR_IFLOW|\
92 			CDSR_OFLOW|CCAR_OFLOW)
93 
94 #define	TTY_CALLOUT(tp,d) ((d) != (tp)->t_dev && (d) != dev_console)
95 
96 /*
97  * Set TTY buffer sizes.
98  */
99 
100 #define	TTYBUF_MAX	65536
101 
102 static void
103 tty_watermarks(struct tty *tp)
104 {
105 	size_t bs;
106 
107 	/* Provide an input buffer for 0.2 seconds of data. */
108 	bs = MIN(tp->t_termios.c_ispeed / 5, TTYBUF_MAX);
109 	ttyinq_setsize(&tp->t_inq, tp, bs);
110 
111 	/* Set low watermark at 10% (when 90% is available). */
112 	tp->t_inlow = (ttyinq_getsize(&tp->t_inq) * 9) / 10;
113 
114 	/* Provide an ouput buffer for 0.2 seconds of data. */
115 	bs = MIN(tp->t_termios.c_ospeed / 5, TTYBUF_MAX);
116 	ttyoutq_setsize(&tp->t_outq, tp, bs);
117 
118 	/* Set low watermark at 10% (when 90% is available). */
119 	tp->t_outlow = (ttyoutq_getsize(&tp->t_outq) * 9) / 10;
120 }
121 
122 static int
123 tty_drain(struct tty *tp)
124 {
125 	int error;
126 
127 	if (ttyhook_hashook(tp, getc_inject))
128 		/* buffer is inaccessible */
129 		return (0);
130 
131 	while (ttyoutq_bytesused(&tp->t_outq) > 0) {
132 		ttydevsw_outwakeup(tp);
133 		/* Could be handled synchronously. */
134 		if (ttyoutq_bytesused(&tp->t_outq) == 0)
135 			return (0);
136 
137 		/* Wait for data to be drained. */
138 		error = tty_wait(tp, &tp->t_outwait);
139 		if (error)
140 			return (error);
141 	}
142 
143 	return (0);
144 }
145 
146 /*
147  * Though ttydev_enter() and ttydev_leave() seem to be related, they
148  * don't have to be used together. ttydev_enter() is used by the cdev
149  * operations to prevent an actual operation from being processed when
150  * the TTY has been abandoned. ttydev_leave() is used by ttydev_open()
151  * and ttydev_close() to determine whether per-TTY data should be
152  * deallocated.
153  */
154 
155 static __inline int
156 ttydev_enter(struct tty *tp)
157 {
158 	tty_lock(tp);
159 
160 	if (tty_gone(tp) || !tty_opened(tp)) {
161 		/* Device is already gone. */
162 		tty_unlock(tp);
163 		return (ENXIO);
164 	}
165 
166 	return (0);
167 }
168 
169 static void
170 ttydev_leave(struct tty *tp)
171 {
172 	tty_lock_assert(tp, MA_OWNED);
173 
174 	if (tty_opened(tp) || tp->t_flags & TF_OPENCLOSE) {
175 		/* Device is still opened somewhere. */
176 		tty_unlock(tp);
177 		return;
178 	}
179 
180 	tp->t_flags |= TF_OPENCLOSE;
181 
182 	/* Stop asynchronous I/O. */
183 	funsetown(&tp->t_sigio);
184 
185 	/* Remove console TTY. */
186 	if (constty == tp)
187 		constty_clear();
188 
189 	/* Drain any output. */
190 	MPASS((tp->t_flags & TF_STOPPED) == 0);
191 	if (!tty_gone(tp))
192 		tty_drain(tp);
193 
194 	ttydisc_close(tp);
195 
196 	/* Destroy associated buffers already. */
197 	ttyinq_free(&tp->t_inq);
198 	tp->t_inlow = 0;
199 	ttyoutq_free(&tp->t_outq);
200 	tp->t_outlow = 0;
201 
202 	knlist_clear(&tp->t_inpoll.si_note, 1);
203 	knlist_clear(&tp->t_outpoll.si_note, 1);
204 
205 	if (!tty_gone(tp))
206 		ttydevsw_close(tp);
207 
208 	tp->t_flags &= ~TF_OPENCLOSE;
209 	cv_broadcast(&tp->t_dcdwait);
210 	tty_rel_free(tp);
211 }
212 
213 /*
214  * Operations that are exposed through the character device in /dev.
215  */
216 static int
217 ttydev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
218 {
219 	struct tty *tp = dev->si_drv1;
220 	int error = 0;
221 
222 	tty_lock(tp);
223 	if (tty_gone(tp)) {
224 		/* Device is already gone. */
225 		tty_unlock(tp);
226 		return (ENXIO);
227 	}
228 
229 	/*
230 	 * Block when other processes are currently opening or closing
231 	 * the TTY.
232 	 */
233 	while (tp->t_flags & TF_OPENCLOSE) {
234 		error = tty_wait(tp, &tp->t_dcdwait);
235 		if (error != 0) {
236 			tty_unlock(tp);
237 			return (error);
238 		}
239 	}
240 	tp->t_flags |= TF_OPENCLOSE;
241 
242 	/*
243 	 * Make sure the "tty" and "cua" device cannot be opened at the
244 	 * same time.
245 	 */
246 	if (TTY_CALLOUT(tp, dev)) {
247 		if (tp->t_flags & TF_OPENED_IN) {
248 			error = EBUSY;
249 			goto done;
250 		}
251 	} else {
252 		if (tp->t_flags & TF_OPENED_OUT) {
253 			error = EBUSY;
254 			goto done;
255 		}
256 	}
257 
258 	if (tp->t_flags & TF_EXCLUDE && priv_check(td, PRIV_TTY_EXCLUSIVE)) {
259 		error = EBUSY;
260 		goto done;
261 	}
262 
263 	if (!tty_opened(tp)) {
264 		/* Set proper termios flags. */
265 		if (TTY_CALLOUT(tp, dev)) {
266 			tp->t_termios = tp->t_termios_init_out;
267 		} else {
268 			tp->t_termios = tp->t_termios_init_in;
269 		}
270 		ttydevsw_param(tp, &tp->t_termios);
271 
272 		ttydevsw_modem(tp, SER_DTR|SER_RTS, 0);
273 
274 		error = ttydevsw_open(tp);
275 		if (error != 0)
276 			goto done;
277 
278 		ttydisc_open(tp);
279 		tty_watermarks(tp);
280 	}
281 
282 	/* Wait for Carrier Detect. */
283 	if (!TTY_CALLOUT(tp, dev) && (oflags & O_NONBLOCK) == 0 &&
284 	    (tp->t_termios.c_cflag & CLOCAL) == 0) {
285 		while ((ttydevsw_modem(tp, 0, 0) & SER_DCD) == 0) {
286 			error = tty_wait(tp, &tp->t_dcdwait);
287 			if (error != 0)
288 				goto done;
289 		}
290 	}
291 
292 	if (dev == dev_console)
293 		tp->t_flags |= TF_OPENED_CONS;
294 	else if (TTY_CALLOUT(tp, dev))
295 		tp->t_flags |= TF_OPENED_OUT;
296 	else
297 		tp->t_flags |= TF_OPENED_IN;
298 
299 done:	tp->t_flags &= ~TF_OPENCLOSE;
300 	cv_broadcast(&tp->t_dcdwait);
301 	ttydev_leave(tp);
302 
303 	return (error);
304 }
305 
306 static int
307 ttydev_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
308 {
309 	struct tty *tp = dev->si_drv1;
310 
311 	tty_lock(tp);
312 
313 	/*
314 	 * Don't actually close the device if it is being used as the
315 	 * console.
316 	 */
317 	MPASS((tp->t_flags & TF_OPENED) != TF_OPENED);
318 	if (dev == dev_console)
319 		tp->t_flags &= ~TF_OPENED_CONS;
320 	else
321 		tp->t_flags &= ~(TF_OPENED_IN|TF_OPENED_OUT);
322 
323 	if (tp->t_flags & TF_OPENED) {
324 		tty_unlock(tp);
325 		return (0);
326 	}
327 
328 	/*
329 	 * This can only be called once. The callin and the callout
330 	 * devices cannot be opened at the same time.
331 	 */
332 	tp->t_flags &= ~(TF_EXCLUDE|TF_STOPPED);
333 
334 	/* Properly wake up threads that are stuck - revoke(). */
335 	tp->t_revokecnt++;
336 	tty_wakeup(tp, FREAD|FWRITE);
337 	cv_broadcast(&tp->t_bgwait);
338 	cv_broadcast(&tp->t_dcdwait);
339 
340 	ttydev_leave(tp);
341 
342 	return (0);
343 }
344 
345 static __inline int
346 tty_is_ctty(struct tty *tp, struct proc *p)
347 {
348 	tty_lock_assert(tp, MA_OWNED);
349 
350 	return (p->p_session == tp->t_session && p->p_flag & P_CONTROLT);
351 }
352 
353 static int
354 tty_wait_background(struct tty *tp, struct thread *td, int sig)
355 {
356 	struct proc *p = td->td_proc;
357 	struct pgrp *pg;
358 	int error;
359 
360 	MPASS(sig == SIGTTIN || sig == SIGTTOU);
361 	tty_lock_assert(tp, MA_OWNED);
362 
363 	for (;;) {
364 		PROC_LOCK(p);
365 		/*
366 		 * The process should only sleep, when:
367 		 * - This terminal is the controling terminal
368 		 * - Its process group is not the foreground process
369 		 *   group
370 		 * - The parent process isn't waiting for the child to
371 		 *   exit
372 		 * - the signal to send to the process isn't masked
373 		 */
374 		if (!tty_is_ctty(tp, p) || p->p_pgrp == tp->t_pgrp) {
375 			/* Allow the action to happen. */
376 			PROC_UNLOCK(p);
377 			return (0);
378 		}
379 
380 		if (SIGISMEMBER(p->p_sigacts->ps_sigignore, sig) ||
381 		    SIGISMEMBER(td->td_sigmask, sig)) {
382 			/* Only allow them in write()/ioctl(). */
383 			PROC_UNLOCK(p);
384 			return (sig == SIGTTOU ? 0 : EIO);
385 		}
386 
387 		pg = p->p_pgrp;
388 		if (p->p_flag & P_PPWAIT || pg->pg_jobc == 0) {
389 			/* Don't allow the action to happen. */
390 			PROC_UNLOCK(p);
391 			return (EIO);
392 		}
393 		PROC_UNLOCK(p);
394 
395 		/*
396 		 * Send the signal and sleep until we're the new
397 		 * foreground process group.
398 		 */
399 		PGRP_LOCK(pg);
400 		pgsignal(pg, sig, 1);
401 		PGRP_UNLOCK(pg);
402 
403 		error = tty_wait(tp, &tp->t_bgwait);
404 		if (error)
405 			return (error);
406 	}
407 }
408 
409 static int
410 ttydev_read(struct cdev *dev, struct uio *uio, int ioflag)
411 {
412 	struct tty *tp = dev->si_drv1;
413 	int error;
414 
415 	error = ttydev_enter(tp);
416 	if (error)
417 		goto done;
418 
419 	error = tty_wait_background(tp, curthread, SIGTTIN);
420 	if (error) {
421 		tty_unlock(tp);
422 		goto done;
423 	}
424 
425 	error = ttydisc_read(tp, uio, ioflag);
426 	tty_unlock(tp);
427 
428 	/*
429 	 * The read() call should not throw an error when the device is
430 	 * being destroyed. Silently convert it to an EOF.
431 	 */
432 done:	if (error == ENXIO)
433 		error = 0;
434 	return (error);
435 }
436 
437 static int
438 ttydev_write(struct cdev *dev, struct uio *uio, int ioflag)
439 {
440 	struct tty *tp = dev->si_drv1;
441 	int error;
442 
443 	error = ttydev_enter(tp);
444 	if (error)
445 		return (error);
446 
447 	if (tp->t_termios.c_lflag & TOSTOP) {
448 		error = tty_wait_background(tp, curthread, SIGTTOU);
449 		if (error)
450 			goto done;
451 	}
452 
453 	if (ioflag & IO_NDELAY && tp->t_flags & TF_BUSY_OUT) {
454 		/* Allow non-blocking writes to bypass serialization. */
455 		error = ttydisc_write(tp, uio, ioflag);
456 	} else {
457 		/* Serialize write() calls. */
458 		while (tp->t_flags & TF_BUSY_OUT) {
459 			error = tty_wait(tp, &tp->t_outserwait);
460 			if (error)
461 				goto done;
462 		}
463 
464  		tp->t_flags |= TF_BUSY_OUT;
465 		error = ttydisc_write(tp, uio, ioflag);
466  		tp->t_flags &= ~TF_BUSY_OUT;
467 		cv_signal(&tp->t_outserwait);
468 	}
469 
470 done:	tty_unlock(tp);
471 	return (error);
472 }
473 
474 static int
475 ttydev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
476     struct thread *td)
477 {
478 	struct tty *tp = dev->si_drv1;
479 	int error;
480 
481 	error = ttydev_enter(tp);
482 	if (error)
483 		return (error);
484 
485 	switch (cmd) {
486 	case TIOCCBRK:
487 	case TIOCCONS:
488 	case TIOCDRAIN:
489 	case TIOCEXCL:
490 	case TIOCFLUSH:
491 	case TIOCNXCL:
492 	case TIOCSBRK:
493 	case TIOCSCTTY:
494 	case TIOCSETA:
495 	case TIOCSETAF:
496 	case TIOCSETAW:
497 	case TIOCSPGRP:
498 	case TIOCSTART:
499 	case TIOCSTAT:
500 	case TIOCSTOP:
501 	case TIOCSWINSZ:
502 #if 0
503 	case TIOCSDRAINWAIT:
504 	case TIOCSETD:
505 	case TIOCSTI:
506 #endif
507 #ifdef COMPAT_43TTY
508 	case  TIOCLBIC:
509 	case  TIOCLBIS:
510 	case  TIOCLSET:
511 	case  TIOCSETC:
512 	case OTIOCSETD:
513 	case  TIOCSETN:
514 	case  TIOCSETP:
515 	case  TIOCSLTC:
516 #endif /* COMPAT_43TTY */
517 		/*
518 		 * If the ioctl() causes the TTY to be modified, let it
519 		 * wait in the background.
520 		 */
521 		error = tty_wait_background(tp, curthread, SIGTTOU);
522 		if (error)
523 			goto done;
524 	}
525 
526 	error = tty_ioctl(tp, cmd, data, td);
527 done:	tty_unlock(tp);
528 
529 	return (error);
530 }
531 
532 static int
533 ttydev_poll(struct cdev *dev, int events, struct thread *td)
534 {
535 	struct tty *tp = dev->si_drv1;
536 	int error, revents = 0;
537 
538 	error = ttydev_enter(tp);
539 	if (error)
540 		return ((events & (POLLIN|POLLRDNORM)) | POLLHUP);
541 
542 	if (events & (POLLIN|POLLRDNORM)) {
543 		/* See if we can read something. */
544 		if (ttydisc_read_poll(tp) > 0)
545 			revents |= events & (POLLIN|POLLRDNORM);
546 	}
547 
548 	if (tp->t_flags & TF_ZOMBIE) {
549 		/* Hangup flag on zombie state. */
550 		revents |= POLLHUP;
551 	} else if (events & (POLLOUT|POLLWRNORM)) {
552 		/* See if we can write something. */
553 		if (ttydisc_write_poll(tp) > 0)
554 			revents |= events & (POLLOUT|POLLWRNORM);
555 	}
556 
557 	if (revents == 0) {
558 		if (events & (POLLIN|POLLRDNORM))
559 			selrecord(td, &tp->t_inpoll);
560 		if (events & (POLLOUT|POLLWRNORM))
561 			selrecord(td, &tp->t_outpoll);
562 	}
563 
564 	tty_unlock(tp);
565 
566 	return (revents);
567 }
568 
569 static int
570 ttydev_mmap(struct cdev *dev, vm_offset_t offset, vm_paddr_t *paddr, int nprot)
571 {
572 	struct tty *tp = dev->si_drv1;
573 	int error;
574 
575 	/* Handle mmap() through the driver. */
576 
577 	error = ttydev_enter(tp);
578 	if (error)
579 		return (-1);
580 	error = ttydevsw_mmap(tp, offset, paddr, nprot);
581 	tty_unlock(tp);
582 
583 	return (error);
584 }
585 
586 /*
587  * kqueue support.
588  */
589 
590 static void
591 tty_kqops_read_detach(struct knote *kn)
592 {
593 	struct tty *tp = kn->kn_hook;
594 
595 	knlist_remove(&tp->t_inpoll.si_note, kn, 0);
596 }
597 
598 static int
599 tty_kqops_read_event(struct knote *kn, long hint)
600 {
601 	struct tty *tp = kn->kn_hook;
602 
603 	tty_lock_assert(tp, MA_OWNED);
604 
605 	if (tty_gone(tp) || tp->t_flags & TF_ZOMBIE) {
606 		kn->kn_flags |= EV_EOF;
607 		return (1);
608 	} else {
609 		kn->kn_data = ttydisc_read_poll(tp);
610 		return (kn->kn_data > 0);
611 	}
612 }
613 
614 static void
615 tty_kqops_write_detach(struct knote *kn)
616 {
617 	struct tty *tp = kn->kn_hook;
618 
619 	knlist_remove(&tp->t_outpoll.si_note, kn, 0);
620 }
621 
622 static int
623 tty_kqops_write_event(struct knote *kn, long hint)
624 {
625 	struct tty *tp = kn->kn_hook;
626 
627 	tty_lock_assert(tp, MA_OWNED);
628 
629 	if (tty_gone(tp)) {
630 		kn->kn_flags |= EV_EOF;
631 		return (1);
632 	} else {
633 		kn->kn_data = ttydisc_write_poll(tp);
634 		return (kn->kn_data > 0);
635 	}
636 }
637 
638 static struct filterops tty_kqops_read =
639     { 1, NULL, tty_kqops_read_detach, tty_kqops_read_event };
640 static struct filterops tty_kqops_write =
641     { 1, NULL, tty_kqops_write_detach, tty_kqops_write_event };
642 
643 static int
644 ttydev_kqfilter(struct cdev *dev, struct knote *kn)
645 {
646 	struct tty *tp = dev->si_drv1;
647 	int error;
648 
649 	error = ttydev_enter(tp);
650 	if (error)
651 		return (error);
652 
653 	switch (kn->kn_filter) {
654 	case EVFILT_READ:
655 		kn->kn_hook = tp;
656 		kn->kn_fop = &tty_kqops_read;
657 		knlist_add(&tp->t_inpoll.si_note, kn, 1);
658 		break;
659 	case EVFILT_WRITE:
660 		kn->kn_hook = tp;
661 		kn->kn_fop = &tty_kqops_write;
662 		knlist_add(&tp->t_outpoll.si_note, kn, 1);
663 		break;
664 	default:
665 		error = EINVAL;
666 		break;
667 	}
668 
669 	tty_unlock(tp);
670 	return (error);
671 }
672 
673 static struct cdevsw ttydev_cdevsw = {
674 	.d_version	= D_VERSION,
675 	.d_open		= ttydev_open,
676 	.d_close	= ttydev_close,
677 	.d_read		= ttydev_read,
678 	.d_write	= ttydev_write,
679 	.d_ioctl	= ttydev_ioctl,
680 	.d_kqfilter	= ttydev_kqfilter,
681 	.d_poll		= ttydev_poll,
682 	.d_mmap		= ttydev_mmap,
683 	.d_name		= "ttydev",
684 	.d_flags	= D_TTY,
685 };
686 
687 /*
688  * Init/lock-state devices
689  */
690 
691 static int
692 ttyil_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
693 {
694 	struct tty *tp = dev->si_drv1;
695 	int error = 0;
696 
697 	tty_lock(tp);
698 	if (tty_gone(tp))
699 		error = ENODEV;
700 	tty_unlock(tp);
701 
702 	return (error);
703 }
704 
705 static int
706 ttyil_close(struct cdev *dev, int flag, int mode, struct thread *td)
707 {
708 	return (0);
709 }
710 
711 static int
712 ttyil_rdwr(struct cdev *dev, struct uio *uio, int ioflag)
713 {
714 	return (ENODEV);
715 }
716 
717 static int
718 ttyil_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
719     struct thread *td)
720 {
721 	struct tty *tp = dev->si_drv1;
722 	int error = 0;
723 
724 	tty_lock(tp);
725 	if (tty_gone(tp)) {
726 		error = ENODEV;
727 		goto done;
728 	}
729 
730 	switch (cmd) {
731 	case TIOCGETA:
732 		/* Obtain terminal flags through tcgetattr(). */
733 		*(struct termios*)data = *(struct termios*)dev->si_drv2;
734 		break;
735 	case TIOCSETA:
736 		/* Set terminal flags through tcsetattr(). */
737 		error = priv_check(td, PRIV_TTY_SETA);
738 		if (error)
739 			break;
740 		*(struct termios*)dev->si_drv2 = *(struct termios*)data;
741 		break;
742 	case TIOCGETD:
743 		*(int *)data = TTYDISC;
744 		break;
745 	case TIOCGWINSZ:
746 		bzero(data, sizeof(struct winsize));
747 		break;
748 	default:
749 		error = ENOTTY;
750 	}
751 
752 done:	tty_unlock(tp);
753 	return (error);
754 }
755 
756 static struct cdevsw ttyil_cdevsw = {
757 	.d_version	= D_VERSION,
758 	.d_open		= ttyil_open,
759 	.d_close	= ttyil_close,
760 	.d_read		= ttyil_rdwr,
761 	.d_write	= ttyil_rdwr,
762 	.d_ioctl	= ttyil_ioctl,
763 	.d_name		= "ttyil",
764 	.d_flags	= D_TTY,
765 };
766 
767 static void
768 tty_init_termios(struct tty *tp)
769 {
770 	struct termios *t = &tp->t_termios_init_in;
771 
772 	t->c_cflag = TTYDEF_CFLAG;
773 	t->c_iflag = TTYDEF_IFLAG;
774 	t->c_lflag = TTYDEF_LFLAG;
775 	t->c_oflag = TTYDEF_OFLAG;
776 	t->c_ispeed = TTYDEF_SPEED;
777 	t->c_ospeed = TTYDEF_SPEED;
778 	memcpy(&t->c_cc, ttydefchars, sizeof ttydefchars);
779 
780 	tp->t_termios_init_out = *t;
781 }
782 
783 void
784 tty_init_console(struct tty *tp, speed_t s)
785 {
786 	struct termios *ti = &tp->t_termios_init_in;
787 	struct termios *to = &tp->t_termios_init_out;
788 
789 	if (s != 0) {
790 		ti->c_ispeed = ti->c_ospeed = s;
791 		to->c_ispeed = to->c_ospeed = s;
792 	}
793 
794 	ti->c_cflag |= CLOCAL;
795 	to->c_cflag |= CLOCAL;
796 }
797 
798 /*
799  * Standard device routine implementations, mostly meant for
800  * pseudo-terminal device drivers. When a driver creates a new terminal
801  * device class, missing routines are patched.
802  */
803 
804 static int
805 ttydevsw_defopen(struct tty *tp)
806 {
807 
808 	return (0);
809 }
810 
811 static void
812 ttydevsw_defclose(struct tty *tp)
813 {
814 }
815 
816 static void
817 ttydevsw_defoutwakeup(struct tty *tp)
818 {
819 
820 	panic("Terminal device has output, while not implemented");
821 }
822 
823 static void
824 ttydevsw_definwakeup(struct tty *tp)
825 {
826 }
827 
828 static int
829 ttydevsw_defioctl(struct tty *tp, u_long cmd, caddr_t data, struct thread *td)
830 {
831 
832 	return (ENOIOCTL);
833 }
834 
835 static int
836 ttydevsw_defparam(struct tty *tp, struct termios *t)
837 {
838 
839 	/* Use a fake baud rate, we're not a real device. */
840 	t->c_ispeed = t->c_ospeed = TTYDEF_SPEED;
841 
842 	return (0);
843 }
844 
845 static int
846 ttydevsw_defmodem(struct tty *tp, int sigon, int sigoff)
847 {
848 
849 	/* Simulate a carrier to make the TTY layer happy. */
850 	return (SER_DCD);
851 }
852 
853 static int
854 ttydevsw_defmmap(struct tty *tp, vm_offset_t offset, vm_paddr_t *paddr,
855     int nprot)
856 {
857 
858 	return (-1);
859 }
860 
861 static void
862 ttydevsw_defpktnotify(struct tty *tp, char event)
863 {
864 }
865 
866 static void
867 ttydevsw_deffree(void *softc)
868 {
869 
870 	panic("Terminal device freed without a free-handler");
871 }
872 
873 /*
874  * TTY allocation and deallocation. TTY devices can be deallocated when
875  * the driver doesn't use it anymore, when the TTY isn't a session's
876  * controlling TTY and when the device node isn't opened through devfs.
877  */
878 
879 struct tty *
880 tty_alloc(struct ttydevsw *tsw, void *sc)
881 {
882 
883 	return (tty_alloc_mutex(tsw, sc, NULL));
884 }
885 
886 struct tty *
887 tty_alloc_mutex(struct ttydevsw *tsw, void *sc, struct mtx *mutex)
888 {
889 	struct tty *tp;
890 
891 	/* Make sure the driver defines all routines. */
892 #define PATCH_FUNC(x) do {				\
893 	if (tsw->tsw_ ## x == NULL)			\
894 		tsw->tsw_ ## x = ttydevsw_def ## x;	\
895 } while (0)
896 	PATCH_FUNC(open);
897 	PATCH_FUNC(close);
898 	PATCH_FUNC(outwakeup);
899 	PATCH_FUNC(inwakeup);
900 	PATCH_FUNC(ioctl);
901 	PATCH_FUNC(param);
902 	PATCH_FUNC(modem);
903 	PATCH_FUNC(mmap);
904 	PATCH_FUNC(pktnotify);
905 	PATCH_FUNC(free);
906 #undef PATCH_FUNC
907 
908 	tp = malloc(sizeof(struct tty), M_TTY, M_WAITOK|M_ZERO);
909 	tp->t_devsw = tsw;
910 	tp->t_devswsoftc = sc;
911 	tp->t_flags = tsw->tsw_flags;
912 
913 	tty_init_termios(tp);
914 
915 	cv_init(&tp->t_inwait, "ttyin");
916 	cv_init(&tp->t_outwait, "ttyout");
917 	cv_init(&tp->t_outserwait, "ttyosr");
918 	cv_init(&tp->t_bgwait, "ttybg");
919 	cv_init(&tp->t_dcdwait, "ttydcd");
920 
921 	/* Allow drivers to use a custom mutex to lock the TTY. */
922 	if (mutex != NULL) {
923 		tp->t_mtx = mutex;
924 	} else {
925 		tp->t_mtx = &tp->t_mtxobj;
926 		mtx_init(&tp->t_mtxobj, "ttymtx", NULL, MTX_DEF);
927 	}
928 
929 	knlist_init_mtx(&tp->t_inpoll.si_note, tp->t_mtx);
930 	knlist_init_mtx(&tp->t_outpoll.si_note, tp->t_mtx);
931 
932 	sx_xlock(&tty_list_sx);
933 	TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
934 	tty_list_count++;
935 	sx_xunlock(&tty_list_sx);
936 
937 	return (tp);
938 }
939 
940 static void
941 tty_dealloc(void *arg)
942 {
943 	struct tty *tp = arg;
944 
945 	sx_xlock(&tty_list_sx);
946 	TAILQ_REMOVE(&tty_list, tp, t_list);
947 	tty_list_count--;
948 	sx_xunlock(&tty_list_sx);
949 
950 	/* Make sure we haven't leaked buffers. */
951 	MPASS(ttyinq_getsize(&tp->t_inq) == 0);
952 	MPASS(ttyoutq_getsize(&tp->t_outq) == 0);
953 
954 	knlist_destroy(&tp->t_inpoll.si_note);
955 	knlist_destroy(&tp->t_outpoll.si_note);
956 
957 	cv_destroy(&tp->t_inwait);
958 	cv_destroy(&tp->t_outwait);
959 	cv_destroy(&tp->t_bgwait);
960 	cv_destroy(&tp->t_dcdwait);
961 	cv_destroy(&tp->t_outserwait);
962 
963 	if (tp->t_mtx == &tp->t_mtxobj)
964 		mtx_destroy(&tp->t_mtxobj);
965 	ttydevsw_free(tp);
966 	free(tp, M_TTY);
967 }
968 
969 static void
970 tty_rel_free(struct tty *tp)
971 {
972 	struct cdev *dev;
973 
974 	tty_lock_assert(tp, MA_OWNED);
975 
976 #define	TF_ACTIVITY	(TF_GONE|TF_OPENED|TF_HOOK|TF_OPENCLOSE)
977 	if (tp->t_sessioncnt != 0 || (tp->t_flags & TF_ACTIVITY) != TF_GONE) {
978 		/* TTY is still in use. */
979 		tty_unlock(tp);
980 		return;
981 	}
982 
983 	/* TTY can be deallocated. */
984 	dev = tp->t_dev;
985 	tp->t_dev = NULL;
986 	tty_unlock(tp);
987 
988 	destroy_dev_sched_cb(dev, tty_dealloc, tp);
989 }
990 
991 void
992 tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
993 {
994 	MPASS(tp->t_sessioncnt > 0);
995 	tty_lock_assert(tp, MA_OWNED);
996 
997 	if (tp->t_pgrp == pg)
998 		tp->t_pgrp = NULL;
999 
1000 	tty_unlock(tp);
1001 }
1002 
1003 void
1004 tty_rel_sess(struct tty *tp, struct session *sess)
1005 {
1006 	MPASS(tp->t_sessioncnt > 0);
1007 
1008 	/* Current session has left. */
1009 	if (tp->t_session == sess) {
1010 		tp->t_session = NULL;
1011 		MPASS(tp->t_pgrp == NULL);
1012 	}
1013 	tp->t_sessioncnt--;
1014 	tty_rel_free(tp);
1015 }
1016 
1017 void
1018 tty_rel_gone(struct tty *tp)
1019 {
1020 	MPASS(!tty_gone(tp));
1021 
1022 	/* Simulate carrier removal. */
1023 	ttydisc_modem(tp, 0);
1024 
1025 	/* Wake up all blocked threads. */
1026 	tty_wakeup(tp, FREAD|FWRITE);
1027 	cv_broadcast(&tp->t_bgwait);
1028 	cv_broadcast(&tp->t_dcdwait);
1029 
1030 	tp->t_flags |= TF_GONE;
1031 	tty_rel_free(tp);
1032 }
1033 
1034 /*
1035  * Exposing information about current TTY's through sysctl
1036  */
1037 
1038 static void
1039 tty_to_xtty(struct tty *tp, struct xtty *xt)
1040 {
1041 	tty_lock_assert(tp, MA_OWNED);
1042 
1043 	xt->xt_size = sizeof(struct xtty);
1044 	xt->xt_insize = ttyinq_getsize(&tp->t_inq);
1045 	xt->xt_incc = ttyinq_bytescanonicalized(&tp->t_inq);
1046 	xt->xt_inlc = ttyinq_bytesline(&tp->t_inq);
1047 	xt->xt_inlow = tp->t_inlow;
1048 	xt->xt_outsize = ttyoutq_getsize(&tp->t_outq);
1049 	xt->xt_outcc = ttyoutq_bytesused(&tp->t_outq);
1050 	xt->xt_outlow = tp->t_outlow;
1051 	xt->xt_column = tp->t_column;
1052 	xt->xt_pgid = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
1053 	xt->xt_sid = tp->t_session ? tp->t_session->s_sid : 0;
1054 	xt->xt_flags = tp->t_flags;
1055 	xt->xt_dev = tp->t_dev ? dev2udev(tp->t_dev) : NODEV;
1056 }
1057 
1058 static int
1059 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
1060 {
1061 	unsigned long lsize;
1062 	struct xtty *xtlist, *xt;
1063 	struct tty *tp;
1064 	int error;
1065 
1066 	sx_slock(&tty_list_sx);
1067 	lsize = tty_list_count * sizeof(struct xtty);
1068 	if (lsize == 0) {
1069 		sx_sunlock(&tty_list_sx);
1070 		return (0);
1071 	}
1072 
1073 	xtlist = xt = malloc(lsize, M_TTY, M_WAITOK);
1074 
1075 	TAILQ_FOREACH(tp, &tty_list, t_list) {
1076 		tty_lock(tp);
1077 		tty_to_xtty(tp, xt);
1078 		tty_unlock(tp);
1079 		xt++;
1080 	}
1081 	sx_sunlock(&tty_list_sx);
1082 
1083 	error = SYSCTL_OUT(req, xtlist, lsize);
1084 	free(xtlist, M_TTY);
1085 	return (error);
1086 }
1087 
1088 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
1089 	0, 0, sysctl_kern_ttys, "S,xtty", "List of TTYs");
1090 
1091 /*
1092  * Device node creation. Device has been set up, now we can expose it to
1093  * the user.
1094  */
1095 
1096 void
1097 tty_makedev(struct tty *tp, struct ucred *cred, const char *fmt, ...)
1098 {
1099 	va_list ap;
1100 	struct cdev *dev;
1101 	const char *prefix = "tty";
1102 	char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
1103 	uid_t uid;
1104 	gid_t gid;
1105 	mode_t mode;
1106 
1107 	/* Remove "tty" prefix from devices like PTY's. */
1108 	if (tp->t_flags & TF_NOPREFIX)
1109 		prefix = "";
1110 
1111 	va_start(ap, fmt);
1112 	vsnrprintf(name, sizeof name, 32, fmt, ap);
1113 	va_end(ap);
1114 
1115 	if (cred == NULL) {
1116 		/* System device. */
1117 		uid = UID_ROOT;
1118 		gid = GID_WHEEL;
1119 		mode = S_IRUSR|S_IWUSR;
1120 	} else {
1121 		/* User device. */
1122 		uid = cred->cr_ruid;
1123 		gid = GID_TTY;
1124 		mode = S_IRUSR|S_IWUSR|S_IWGRP;
1125 	}
1126 
1127 	/* Master call-in device. */
1128 	dev = make_dev_cred(&ttydev_cdevsw, 0, cred,
1129 	    uid, gid, mode, "%s%s", prefix, name);
1130 	dev->si_drv1 = tp;
1131 	tp->t_dev = dev;
1132 
1133 	/* Slave call-in devices. */
1134 	if (tp->t_flags & TF_INITLOCK) {
1135 		dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1136 		    uid, gid, mode, "%s%s.init", prefix, name);
1137 		dev_depends(tp->t_dev, dev);
1138 		dev->si_drv1 = tp;
1139 		dev->si_drv2 = &tp->t_termios_init_in;
1140 
1141 		dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1142 		    uid, gid, mode, "%s%s.lock", prefix, name);
1143 		dev_depends(tp->t_dev, dev);
1144 		dev->si_drv1 = tp;
1145 		dev->si_drv2 = &tp->t_termios_lock_in;
1146 	}
1147 
1148 	/* Call-out devices. */
1149 	if (tp->t_flags & TF_CALLOUT) {
1150 		dev = make_dev_cred(&ttydev_cdevsw, 0, cred,
1151 		    UID_UUCP, GID_DIALER, 0660, "cua%s", name);
1152 		dev_depends(tp->t_dev, dev);
1153 		dev->si_drv1 = tp;
1154 
1155 		/* Slave call-out devices. */
1156 		if (tp->t_flags & TF_INITLOCK) {
1157 			dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1158 			    UID_UUCP, GID_DIALER, 0660, "cua%s.init", name);
1159 			dev_depends(tp->t_dev, dev);
1160 			dev->si_drv1 = tp;
1161 			dev->si_drv2 = &tp->t_termios_init_out;
1162 
1163 			dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1164 			    UID_UUCP, GID_DIALER, 0660, "cua%s.lock", name);
1165 			dev_depends(tp->t_dev, dev);
1166 			dev->si_drv1 = tp;
1167 			dev->si_drv2 = &tp->t_termios_lock_out;
1168 		}
1169 	}
1170 }
1171 
1172 /*
1173  * Signalling processes.
1174  */
1175 
1176 void
1177 tty_signal_sessleader(struct tty *tp, int sig)
1178 {
1179 	struct proc *p;
1180 
1181 	tty_lock_assert(tp, MA_OWNED);
1182 	MPASS(sig >= 1 && sig < NSIG);
1183 
1184 	/* Make signals start output again. */
1185 	tp->t_flags &= ~TF_STOPPED;
1186 
1187 	if (tp->t_session != NULL && tp->t_session->s_leader != NULL) {
1188 		p = tp->t_session->s_leader;
1189 		PROC_LOCK(p);
1190 		psignal(p, sig);
1191 		PROC_UNLOCK(p);
1192 	}
1193 }
1194 
1195 void
1196 tty_signal_pgrp(struct tty *tp, int sig)
1197 {
1198 	tty_lock_assert(tp, MA_OWNED);
1199 	MPASS(sig >= 1 && sig < NSIG);
1200 
1201 	/* Make signals start output again. */
1202 	tp->t_flags &= ~TF_STOPPED;
1203 
1204 	if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
1205 		tty_info(tp);
1206 	if (tp->t_pgrp != NULL) {
1207 		PGRP_LOCK(tp->t_pgrp);
1208 		pgsignal(tp->t_pgrp, sig, 1);
1209 		PGRP_UNLOCK(tp->t_pgrp);
1210 	}
1211 }
1212 
1213 void
1214 tty_wakeup(struct tty *tp, int flags)
1215 {
1216 	if (tp->t_flags & TF_ASYNC && tp->t_sigio != NULL)
1217 		pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
1218 
1219 	if (flags & FWRITE) {
1220 		cv_broadcast(&tp->t_outwait);
1221 		selwakeup(&tp->t_outpoll);
1222 		KNOTE_LOCKED(&tp->t_outpoll.si_note, 0);
1223 	}
1224 	if (flags & FREAD) {
1225 		cv_broadcast(&tp->t_inwait);
1226 		selwakeup(&tp->t_inpoll);
1227 		KNOTE_LOCKED(&tp->t_inpoll.si_note, 0);
1228 	}
1229 }
1230 
1231 int
1232 tty_wait(struct tty *tp, struct cv *cv)
1233 {
1234 	int error;
1235 	int revokecnt = tp->t_revokecnt;
1236 
1237 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1238 	MPASS(!tty_gone(tp));
1239 
1240 	error = cv_wait_sig(cv, tp->t_mtx);
1241 
1242 	/* Restart the system call when we may have been revoked. */
1243 	if (tp->t_revokecnt != revokecnt)
1244 		return (ERESTART);
1245 
1246 	/* Bail out when the device slipped away. */
1247 	if (tty_gone(tp))
1248 		return (ENXIO);
1249 
1250 	return (error);
1251 }
1252 
1253 int
1254 tty_timedwait(struct tty *tp, struct cv *cv, int hz)
1255 {
1256 	int error;
1257 	int revokecnt = tp->t_revokecnt;
1258 
1259 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1260 	MPASS(!tty_gone(tp));
1261 
1262 	error = cv_timedwait_sig(cv, tp->t_mtx, hz);
1263 
1264 	/* Restart the system call when we may have been revoked. */
1265 	if (tp->t_revokecnt != revokecnt)
1266 		return (ERESTART);
1267 
1268 	/* Bail out when the device slipped away. */
1269 	if (tty_gone(tp))
1270 		return (ENXIO);
1271 
1272 	return (error);
1273 }
1274 
1275 void
1276 tty_flush(struct tty *tp, int flags)
1277 {
1278 	if (flags & FWRITE) {
1279 		tp->t_flags &= ~TF_HIWAT_OUT;
1280 		ttyoutq_flush(&tp->t_outq);
1281 		tty_wakeup(tp, FWRITE);
1282 		ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
1283 	}
1284 	if (flags & FREAD) {
1285 		tty_hiwat_in_unblock(tp);
1286 		ttyinq_flush(&tp->t_inq);
1287 		ttydevsw_inwakeup(tp);
1288 		ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
1289 	}
1290 }
1291 
1292 static int
1293 tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, struct thread *td)
1294 {
1295 	int error;
1296 
1297 	switch (cmd) {
1298 	/*
1299 	 * Modem commands.
1300 	 * The SER_* and TIOCM_* flags are the same, but one bit
1301 	 * shifted. I don't know why.
1302 	 */
1303 	case TIOCSDTR:
1304 		ttydevsw_modem(tp, SER_DTR, 0);
1305 		return (0);
1306 	case TIOCCDTR:
1307 		ttydevsw_modem(tp, 0, SER_DTR);
1308 		return (0);
1309 	case TIOCMSET: {
1310 		int bits = *(int *)data;
1311 		ttydevsw_modem(tp,
1312 		    (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1,
1313 		    ((~bits) & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1314 		return (0);
1315 	}
1316 	case TIOCMBIS: {
1317 		int bits = *(int *)data;
1318 		ttydevsw_modem(tp, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1, 0);
1319 		return (0);
1320 	}
1321 	case TIOCMBIC: {
1322 		int bits = *(int *)data;
1323 		ttydevsw_modem(tp, 0, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1324 		return (0);
1325 	}
1326 	case TIOCMGET:
1327 		*(int *)data = TIOCM_LE + (ttydevsw_modem(tp, 0, 0) << 1);
1328 		return (0);
1329 
1330 	case FIOASYNC:
1331 		if (*(int *)data)
1332 			tp->t_flags |= TF_ASYNC;
1333 		else
1334 			tp->t_flags &= ~TF_ASYNC;
1335 		return (0);
1336 	case FIONBIO:
1337 		/* This device supports non-blocking operation. */
1338 		return (0);
1339 	case FIONREAD:
1340 		*(int *)data = ttyinq_bytescanonicalized(&tp->t_inq);
1341 		return (0);
1342 	case FIONWRITE:
1343 	case TIOCOUTQ:
1344 		*(int *)data = ttyoutq_bytesused(&tp->t_outq);
1345 		return (0);
1346 	case FIOSETOWN:
1347 		if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1348 			/* Not allowed to set ownership. */
1349 			return (ENOTTY);
1350 
1351 		/* Temporarily unlock the TTY to set ownership. */
1352 		tty_unlock(tp);
1353 		error = fsetown(*(int *)data, &tp->t_sigio);
1354 		tty_lock(tp);
1355 		return (error);
1356 	case FIOGETOWN:
1357 		if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1358 			/* Not allowed to set ownership. */
1359 			return (ENOTTY);
1360 
1361 		/* Get ownership. */
1362 		*(int *)data = fgetown(&tp->t_sigio);
1363 		return (0);
1364 	case TIOCGETA:
1365 		/* Obtain terminal flags through tcgetattr(). */
1366 		*(struct termios*)data = tp->t_termios;
1367 		return (0);
1368 	case TIOCSETA:
1369 	case TIOCSETAW:
1370 	case TIOCSETAF: {
1371 		struct termios *t = data;
1372 
1373 		/*
1374 		 * Who makes up these funny rules? According to POSIX,
1375 		 * input baud rate is set equal to the output baud rate
1376 		 * when zero.
1377 		 */
1378 		if (t->c_ispeed == 0)
1379 			t->c_ispeed = t->c_ospeed;
1380 
1381 		/* Discard any unsupported bits. */
1382 		t->c_iflag &= TTYSUP_IFLAG;
1383 		t->c_oflag &= TTYSUP_OFLAG;
1384 		t->c_lflag &= TTYSUP_LFLAG;
1385 		t->c_cflag &= TTYSUP_CFLAG;
1386 
1387 		/* Set terminal flags through tcsetattr(). */
1388 		if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
1389 			error = tty_drain(tp);
1390 			if (error)
1391 				return (error);
1392 			if (cmd == TIOCSETAF)
1393 				tty_flush(tp, FREAD);
1394 		}
1395 
1396 		/*
1397 		 * Only call param() when the flags really change.
1398 		 */
1399 		if ((t->c_cflag & CIGNORE) == 0 &&
1400 		    (tp->t_termios.c_cflag != t->c_cflag ||
1401 		    tp->t_termios.c_ispeed != t->c_ispeed ||
1402 		    tp->t_termios.c_ospeed != t->c_ospeed)) {
1403 			error = ttydevsw_param(tp, t);
1404 			if (error)
1405 				return (error);
1406 
1407 			/* XXX: CLOCAL? */
1408 
1409 			tp->t_termios.c_cflag = t->c_cflag & ~CIGNORE;
1410 			tp->t_termios.c_ispeed = t->c_ispeed;
1411 			tp->t_termios.c_ospeed = t->c_ospeed;
1412 
1413 			/* Baud rate has changed - update watermarks. */
1414 			tty_watermarks(tp);
1415 		}
1416 
1417 		/* Copy new non-device driver parameters. */
1418 		tp->t_termios.c_iflag = t->c_iflag;
1419 		tp->t_termios.c_oflag = t->c_oflag;
1420 		tp->t_termios.c_lflag = t->c_lflag;
1421 		memcpy(&tp->t_termios.c_cc, t->c_cc, sizeof t->c_cc);
1422 
1423 		ttydisc_optimize(tp);
1424 
1425 		if ((t->c_lflag & ICANON) == 0) {
1426 			/*
1427 			 * When in non-canonical mode, wake up all
1428 			 * readers. Canonicalize any partial input. VMIN
1429 			 * and VTIME could also be adjusted.
1430 			 */
1431 			ttyinq_canonicalize(&tp->t_inq);
1432 			tty_wakeup(tp, FREAD);
1433 		}
1434 
1435 		/*
1436 		 * For packet mode: notify the PTY consumer that VSTOP
1437 		 * and VSTART may have been changed.
1438 		 */
1439 		if (tp->t_termios.c_iflag & IXON &&
1440 		    tp->t_termios.c_cc[VSTOP] == CTRL('S') &&
1441 		    tp->t_termios.c_cc[VSTART] == CTRL('Q'))
1442 			ttydevsw_pktnotify(tp, TIOCPKT_DOSTOP);
1443 		else
1444 			ttydevsw_pktnotify(tp, TIOCPKT_NOSTOP);
1445 		return (0);
1446 	}
1447 	case TIOCGETD:
1448 		/* For compatibility - we only support TTYDISC. */
1449 		*(int *)data = TTYDISC;
1450 		return (0);
1451 	case TIOCGPGRP:
1452 		if (!tty_is_ctty(tp, td->td_proc))
1453 			return (ENOTTY);
1454 
1455 		if (tp->t_pgrp != NULL)
1456 			*(int *)data = tp->t_pgrp->pg_id;
1457 		else
1458 			*(int *)data = NO_PID;
1459 		return (0);
1460 	case TIOCGSID:
1461 		if (!tty_is_ctty(tp, td->td_proc))
1462 			return (ENOTTY);
1463 
1464 		MPASS(tp->t_session);
1465 		*(int *)data = tp->t_session->s_sid;
1466 		return (0);
1467 	case TIOCSCTTY: {
1468 		struct proc *p = td->td_proc;
1469 
1470 		/* XXX: This looks awful. */
1471 		tty_unlock(tp);
1472 		sx_xlock(&proctree_lock);
1473 		tty_lock(tp);
1474 
1475 		if (!SESS_LEADER(p)) {
1476 			/* Only the session leader may do this. */
1477 			sx_xunlock(&proctree_lock);
1478 			return (EPERM);
1479 		}
1480 
1481 		if (tp->t_session != NULL && tp->t_session == p->p_session) {
1482 			/* This is already our controlling TTY. */
1483 			sx_xunlock(&proctree_lock);
1484 			return (0);
1485 		}
1486 
1487 		if (p->p_session->s_ttyp != NULL ||
1488 		    (tp->t_session != NULL && tp->t_session->s_ttyvp != NULL &&
1489 		    tp->t_session->s_ttyvp->v_type != VBAD)) {
1490 			/*
1491 			 * There is already a relation between a TTY and
1492 			 * a session, or the caller is not the session
1493 			 * leader.
1494 			 *
1495 			 * Allow the TTY to be stolen when the vnode is
1496 			 * invalid, but the reference to the TTY is
1497 			 * still active.  This allows immediate reuse of
1498 			 * TTYs of which the session leader has been
1499 			 * killed or the TTY revoked.
1500 			 */
1501 			sx_xunlock(&proctree_lock);
1502 			return (EPERM);
1503 		}
1504 
1505 		/* Connect the session to the TTY. */
1506 		tp->t_session = p->p_session;
1507 		tp->t_session->s_ttyp = tp;
1508 		tp->t_sessioncnt++;
1509 		sx_xunlock(&proctree_lock);
1510 
1511 		/* Assign foreground process group. */
1512 		tp->t_pgrp = p->p_pgrp;
1513 		PROC_LOCK(p);
1514 		p->p_flag |= P_CONTROLT;
1515 		PROC_UNLOCK(p);
1516 
1517 		return (0);
1518 	}
1519 	case TIOCSPGRP: {
1520 		struct pgrp *pg;
1521 
1522 		/*
1523 		 * XXX: Temporarily unlock the TTY to locate the process
1524 		 * group. This code would be lot nicer if we would ever
1525 		 * decompose proctree_lock.
1526 		 */
1527 		tty_unlock(tp);
1528 		sx_slock(&proctree_lock);
1529 		pg = pgfind(*(int *)data);
1530 		if (pg != NULL)
1531 			PGRP_UNLOCK(pg);
1532 		if (pg == NULL || pg->pg_session != td->td_proc->p_session) {
1533 			sx_sunlock(&proctree_lock);
1534 			tty_lock(tp);
1535 			return (EPERM);
1536 		}
1537 		tty_lock(tp);
1538 
1539 		/*
1540 		 * Determine if this TTY is the controlling TTY after
1541 		 * relocking the TTY.
1542 		 */
1543 		if (!tty_is_ctty(tp, td->td_proc)) {
1544 			sx_sunlock(&proctree_lock);
1545 			return (ENOTTY);
1546 		}
1547 		tp->t_pgrp = pg;
1548 		sx_sunlock(&proctree_lock);
1549 
1550 		/* Wake up the background process groups. */
1551 		cv_broadcast(&tp->t_bgwait);
1552 		return (0);
1553 	}
1554 	case TIOCFLUSH: {
1555 		int flags = *(int *)data;
1556 
1557 		if (flags == 0)
1558 			flags = (FREAD|FWRITE);
1559 		else
1560 			flags &= (FREAD|FWRITE);
1561 		tty_flush(tp, flags);
1562 		return (0);
1563 	}
1564 	case TIOCDRAIN:
1565 		/* Drain TTY output. */
1566 		return tty_drain(tp);
1567 	case TIOCCONS:
1568 		/* Set terminal as console TTY. */
1569 		if (*(int *)data) {
1570 			error = priv_check(td, PRIV_TTY_CONSOLE);
1571 			if (error)
1572 				return (error);
1573 
1574 			/*
1575 			 * XXX: constty should really need to be locked!
1576 			 * XXX: allow disconnected constty's to be stolen!
1577 			 */
1578 
1579 			if (constty == tp)
1580 				return (0);
1581 			if (constty != NULL)
1582 				return (EBUSY);
1583 
1584 			tty_unlock(tp);
1585 			constty_set(tp);
1586 			tty_lock(tp);
1587 		} else if (constty == tp) {
1588 			constty_clear();
1589 		}
1590 		return (0);
1591 	case TIOCGWINSZ:
1592 		/* Obtain window size. */
1593 		*(struct winsize*)data = tp->t_winsize;
1594 		return (0);
1595 	case TIOCSWINSZ:
1596 		/* Set window size. */
1597 		if (bcmp(&tp->t_winsize, data, sizeof(struct winsize)) == 0)
1598 			return (0);
1599 		tp->t_winsize = *(struct winsize*)data;
1600 		tty_signal_pgrp(tp, SIGWINCH);
1601 		return (0);
1602 	case TIOCEXCL:
1603 		tp->t_flags |= TF_EXCLUDE;
1604 		return (0);
1605 	case TIOCNXCL:
1606 		tp->t_flags &= ~TF_EXCLUDE;
1607 		return (0);
1608 	case TIOCSTOP:
1609 		tp->t_flags |= TF_STOPPED;
1610 		ttydevsw_pktnotify(tp, TIOCPKT_STOP);
1611 		return (0);
1612 	case TIOCSTART:
1613 		tp->t_flags &= ~TF_STOPPED;
1614 		ttydevsw_outwakeup(tp);
1615 		ttydevsw_pktnotify(tp, TIOCPKT_START);
1616 		return (0);
1617 	case TIOCSTAT:
1618 		tty_info(tp);
1619 		return (0);
1620 	}
1621 
1622 #ifdef COMPAT_43TTY
1623 	return tty_ioctl_compat(tp, cmd, data, td);
1624 #else /* !COMPAT_43TTY */
1625 	return (ENOIOCTL);
1626 #endif /* COMPAT_43TTY */
1627 }
1628 
1629 int
1630 tty_ioctl(struct tty *tp, u_long cmd, void *data, struct thread *td)
1631 {
1632 	int error;
1633 
1634 	tty_lock_assert(tp, MA_OWNED);
1635 
1636 	if (tty_gone(tp))
1637 		return (ENXIO);
1638 
1639 	error = ttydevsw_ioctl(tp, cmd, data, td);
1640 	if (error == ENOIOCTL)
1641 		error = tty_generic_ioctl(tp, cmd, data, td);
1642 
1643 	return (error);
1644 }
1645 
1646 dev_t
1647 tty_udev(struct tty *tp)
1648 {
1649 	if (tp->t_dev)
1650 		return dev2udev(tp->t_dev);
1651 	else
1652 		return NODEV;
1653 }
1654 
1655 int
1656 tty_checkoutq(struct tty *tp)
1657 {
1658 
1659 	/* 256 bytes should be enough to print a log message. */
1660 	return (ttyoutq_bytesleft(&tp->t_outq) >= 256);
1661 }
1662 
1663 void
1664 tty_hiwat_in_block(struct tty *tp)
1665 {
1666 
1667 	if ((tp->t_flags & TF_HIWAT_IN) == 0 &&
1668 	    tp->t_termios.c_iflag & IXOFF &&
1669 	    tp->t_termios.c_cc[VSTOP] != _POSIX_VDISABLE) {
1670 		/*
1671 		 * Input flow control. Only enter the high watermark when we
1672 		 * can successfully store the VSTOP character.
1673 		 */
1674 		if (ttyoutq_write_nofrag(&tp->t_outq,
1675 		    &tp->t_termios.c_cc[VSTOP], 1) == 0)
1676 			tp->t_flags |= TF_HIWAT_IN;
1677 	} else {
1678 		/* No input flow control. */
1679 		tp->t_flags |= TF_HIWAT_IN;
1680 	}
1681 }
1682 
1683 void
1684 tty_hiwat_in_unblock(struct tty *tp)
1685 {
1686 
1687 	if (tp->t_flags & TF_HIWAT_IN &&
1688 	    tp->t_termios.c_iflag & IXOFF &&
1689 	    tp->t_termios.c_cc[VSTART] != _POSIX_VDISABLE) {
1690 		/*
1691 		 * Input flow control. Only leave the high watermark when we
1692 		 * can successfully store the VSTART character.
1693 		 */
1694 		if (ttyoutq_write_nofrag(&tp->t_outq,
1695 		    &tp->t_termios.c_cc[VSTART], 1) == 0)
1696 			tp->t_flags &= ~TF_HIWAT_IN;
1697 	} else {
1698 		/* No input flow control. */
1699 		tp->t_flags &= ~TF_HIWAT_IN;
1700 	}
1701 
1702 	if (!tty_gone(tp))
1703 		ttydevsw_inwakeup(tp);
1704 }
1705 
1706 /*
1707  * TTY hooks interface.
1708  */
1709 
1710 static int
1711 ttyhook_defrint(struct tty *tp, char c, int flags)
1712 {
1713 
1714 	if (ttyhook_rint_bypass(tp, &c, 1) != 1)
1715 		return (-1);
1716 
1717 	return (0);
1718 }
1719 
1720 int
1721 ttyhook_register(struct tty **rtp, struct proc *p, int fd,
1722     struct ttyhook *th, void *softc)
1723 {
1724 	struct tty *tp;
1725 	struct file *fp;
1726 	struct cdev *dev;
1727 	struct cdevsw *cdp;
1728 	struct filedesc *fdp;
1729 	int error;
1730 
1731 	/* Validate the file descriptor. */
1732 	if ((fdp = p->p_fd) == NULL)
1733 		return (EBADF);
1734 
1735 	fp = fget_unlocked(fdp, fd);
1736 	if (fp == NULL)
1737 		return (EBADF);
1738 	if (fp->f_ops == &badfileops) {
1739 		error = EBADF;
1740 		goto done1;
1741 	}
1742 
1743 	/*
1744 	 * Make sure the vnode is bound to a character device.
1745 	 * Unlocked check for the vnode type is ok there, because we
1746 	 * only shall prevent calling devvn_refthread on the file that
1747 	 * never has been opened over a character device.
1748 	 */
1749 	if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR) {
1750 		error = EINVAL;
1751 		goto done1;
1752 	}
1753 
1754 	/* Make sure it is a TTY. */
1755 	cdp = devvn_refthread(fp->f_vnode, &dev);
1756 	if (cdp == NULL) {
1757 		error = ENXIO;
1758 		goto done1;
1759 	}
1760 	if (dev != fp->f_data) {
1761 		error = ENXIO;
1762 		goto done2;
1763 	}
1764 	if (cdp != &ttydev_cdevsw) {
1765 		error = ENOTTY;
1766 		goto done2;
1767 	}
1768 	tp = dev->si_drv1;
1769 
1770 	/* Try to attach the hook to the TTY. */
1771 	error = EBUSY;
1772 	tty_lock(tp);
1773 	MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
1774 	if (tp->t_flags & TF_HOOK)
1775 		goto done3;
1776 
1777 	tp->t_flags |= TF_HOOK;
1778 	tp->t_hook = th;
1779 	tp->t_hooksoftc = softc;
1780 	*rtp = tp;
1781 	error = 0;
1782 
1783 	/* Maybe we can switch into bypass mode now. */
1784 	ttydisc_optimize(tp);
1785 
1786 	/* Silently convert rint() calls to rint_bypass() when possible. */
1787 	if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
1788 		th->th_rint = ttyhook_defrint;
1789 
1790 done3:	tty_unlock(tp);
1791 done2:	dev_relthread(dev);
1792 done1:	fdrop(fp, curthread);
1793 	return (error);
1794 }
1795 
1796 void
1797 ttyhook_unregister(struct tty *tp)
1798 {
1799 
1800 	tty_lock_assert(tp, MA_OWNED);
1801 	MPASS(tp->t_flags & TF_HOOK);
1802 
1803 	/* Disconnect the hook. */
1804 	tp->t_flags &= ~TF_HOOK;
1805 	tp->t_hook = NULL;
1806 
1807 	/* Maybe we need to leave bypass mode. */
1808 	ttydisc_optimize(tp);
1809 
1810 	/* Maybe deallocate the TTY as well. */
1811 	tty_rel_free(tp);
1812 }
1813 
1814 /*
1815  * /dev/console handling.
1816  */
1817 
1818 static int
1819 ttyconsdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
1820 {
1821 	struct tty *tp;
1822 
1823 	/* System has no console device. */
1824 	if (dev_console_filename == NULL)
1825 		return (ENXIO);
1826 
1827 	/* Look up corresponding TTY by device name. */
1828 	sx_slock(&tty_list_sx);
1829 	TAILQ_FOREACH(tp, &tty_list, t_list) {
1830 		if (strcmp(dev_console_filename, tty_devname(tp)) == 0) {
1831 			dev_console->si_drv1 = tp;
1832 			break;
1833 		}
1834 	}
1835 	sx_sunlock(&tty_list_sx);
1836 
1837 	/* System console has no TTY associated. */
1838 	if (dev_console->si_drv1 == NULL)
1839 		return (ENXIO);
1840 
1841 	return (ttydev_open(dev, oflags, devtype, td));
1842 }
1843 
1844 static int
1845 ttyconsdev_write(struct cdev *dev, struct uio *uio, int ioflag)
1846 {
1847 
1848 	log_console(uio);
1849 
1850 	return (ttydev_write(dev, uio, ioflag));
1851 }
1852 
1853 /*
1854  * /dev/console is a little different than normal TTY's.  When opened,
1855  * it determines which TTY to use.  When data gets written to it, it
1856  * will be logged in the kernel message buffer.
1857  */
1858 static struct cdevsw ttyconsdev_cdevsw = {
1859 	.d_version	= D_VERSION,
1860 	.d_open		= ttyconsdev_open,
1861 	.d_close	= ttydev_close,
1862 	.d_read		= ttydev_read,
1863 	.d_write	= ttyconsdev_write,
1864 	.d_ioctl	= ttydev_ioctl,
1865 	.d_kqfilter	= ttydev_kqfilter,
1866 	.d_poll		= ttydev_poll,
1867 	.d_mmap		= ttydev_mmap,
1868 	.d_name		= "ttyconsdev",
1869 	.d_flags	= D_TTY,
1870 };
1871 
1872 static void
1873 ttyconsdev_init(void *unused)
1874 {
1875 
1876 	dev_console = make_dev(&ttyconsdev_cdevsw, 0, UID_ROOT, GID_WHEEL,
1877 	    0600, "console");
1878 }
1879 
1880 SYSINIT(tty, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyconsdev_init, NULL);
1881 
1882 void
1883 ttyconsdev_select(const char *name)
1884 {
1885 
1886 	dev_console_filename = name;
1887 }
1888 
1889 /*
1890  * Debugging routines.
1891  */
1892 
1893 #include "opt_ddb.h"
1894 #ifdef DDB
1895 #include <ddb/ddb.h>
1896 #include <ddb/db_sym.h>
1897 
1898 static struct {
1899 	int flag;
1900 	char val;
1901 } ttystates[] = {
1902 #if 0
1903 	{ TF_NOPREFIX,		'N' },
1904 #endif
1905 	{ TF_INITLOCK,		'I' },
1906 	{ TF_CALLOUT,		'C' },
1907 
1908 	/* Keep these together -> 'Oi' and 'Oo'. */
1909 	{ TF_OPENED,		'O' },
1910 	{ TF_OPENED_IN,		'i' },
1911 	{ TF_OPENED_OUT,	'o' },
1912 	{ TF_OPENED_CONS,	'c' },
1913 
1914 	{ TF_GONE,		'G' },
1915 	{ TF_OPENCLOSE,		'B' },
1916 	{ TF_ASYNC,		'Y' },
1917 	{ TF_LITERAL,		'L' },
1918 
1919 	/* Keep these together -> 'Hi' and 'Ho'. */
1920 	{ TF_HIWAT,		'H' },
1921 	{ TF_HIWAT_IN,		'i' },
1922 	{ TF_HIWAT_OUT,		'o' },
1923 
1924 	{ TF_STOPPED,		'S' },
1925 	{ TF_EXCLUDE,		'X' },
1926 	{ TF_BYPASS,		'l' },
1927 	{ TF_ZOMBIE,		'Z' },
1928 	{ TF_HOOK,		's' },
1929 
1930 	/* Keep these together -> 'bi' and 'bo'. */
1931 	{ TF_BUSY,		'b' },
1932 	{ TF_BUSY_IN,		'i' },
1933 	{ TF_BUSY_OUT,		'o' },
1934 
1935 	{ 0,			'\0'},
1936 };
1937 
1938 #define	TTY_FLAG_BITS \
1939 	"\20\1NOPREFIX\2INITLOCK\3CALLOUT\4OPENED_IN\5OPENED_OUT\6GONE" \
1940 	"\7OPENCLOSE\10ASYNC\11LITERAL\12HIWAT_IN\13HIWAT_OUT\14STOPPED" \
1941 	"\15EXCLUDE\16BYPASS\17ZOMBIE\20HOOK"
1942 
1943 #define DB_PRINTSYM(name, addr) \
1944 	db_printf("%s  " #name ": ", sep); \
1945 	db_printsym((db_addr_t) addr, DB_STGY_ANY); \
1946 	db_printf("\n");
1947 
1948 static void
1949 _db_show_devsw(const char *sep, const struct ttydevsw *tsw)
1950 {
1951 	db_printf("%sdevsw: ", sep);
1952 	db_printsym((db_addr_t)tsw, DB_STGY_ANY);
1953 	db_printf(" (%p)\n", tsw);
1954 	DB_PRINTSYM(open, tsw->tsw_open);
1955 	DB_PRINTSYM(close, tsw->tsw_close);
1956 	DB_PRINTSYM(outwakeup, tsw->tsw_outwakeup);
1957 	DB_PRINTSYM(inwakeup, tsw->tsw_inwakeup);
1958 	DB_PRINTSYM(ioctl, tsw->tsw_ioctl);
1959 	DB_PRINTSYM(param, tsw->tsw_param);
1960 	DB_PRINTSYM(modem, tsw->tsw_modem);
1961 	DB_PRINTSYM(mmap, tsw->tsw_mmap);
1962 	DB_PRINTSYM(pktnotify, tsw->tsw_pktnotify);
1963 	DB_PRINTSYM(free, tsw->tsw_free);
1964 }
1965 static void
1966 _db_show_hooks(const char *sep, const struct ttyhook *th)
1967 {
1968 	db_printf("%shook: ", sep);
1969 	db_printsym((db_addr_t)th, DB_STGY_ANY);
1970 	db_printf(" (%p)\n", th);
1971 	if (th == NULL)
1972 		return;
1973 	DB_PRINTSYM(rint, th->th_rint);
1974 	DB_PRINTSYM(rint_bypass, th->th_rint_bypass);
1975 	DB_PRINTSYM(rint_done, th->th_rint_done);
1976 	DB_PRINTSYM(rint_poll, th->th_rint_poll);
1977 	DB_PRINTSYM(getc_inject, th->th_getc_inject);
1978 	DB_PRINTSYM(getc_capture, th->th_getc_capture);
1979 	DB_PRINTSYM(getc_poll, th->th_getc_poll);
1980 	DB_PRINTSYM(close, th->th_close);
1981 }
1982 
1983 static void
1984 _db_show_termios(const char *name, const struct termios *t)
1985 {
1986 
1987 	db_printf("%s: iflag 0x%x oflag 0x%x cflag 0x%x "
1988 	    "lflag 0x%x ispeed %u ospeed %u\n", name,
1989 	    t->c_iflag, t->c_oflag, t->c_cflag, t->c_lflag,
1990 	    t->c_ispeed, t->c_ospeed);
1991 }
1992 
1993 /* DDB command to show TTY statistics. */
1994 DB_SHOW_COMMAND(tty, db_show_tty)
1995 {
1996 	struct tty *tp;
1997 
1998 	if (!have_addr) {
1999 		db_printf("usage: show tty <addr>\n");
2000 		return;
2001 	}
2002 	tp = (struct tty *)addr;
2003 
2004 	db_printf("0x%p: %s\n", tp, tty_devname(tp));
2005 	db_printf("\tmtx: %p\n", tp->t_mtx);
2006 	db_printf("\tflags: %b\n", tp->t_flags, TTY_FLAG_BITS);
2007 	db_printf("\trevokecnt: %u\n", tp->t_revokecnt);
2008 
2009 	/* Buffering mechanisms. */
2010 	db_printf("\tinq: %p begin %u linestart %u reprint %u end %u "
2011 	    "nblocks %u quota %u\n", &tp->t_inq, tp->t_inq.ti_begin,
2012 	    tp->t_inq.ti_linestart, tp->t_inq.ti_reprint, tp->t_inq.ti_end,
2013 	    tp->t_inq.ti_nblocks, tp->t_inq.ti_quota);
2014 	db_printf("\toutq: %p begin %u end %u nblocks %u quota %u\n",
2015 	    &tp->t_outq, tp->t_outq.to_begin, tp->t_outq.to_end,
2016 	    tp->t_outq.to_nblocks, tp->t_outq.to_quota);
2017 	db_printf("\tinlow: %zu\n", tp->t_inlow);
2018 	db_printf("\toutlow: %zu\n", tp->t_outlow);
2019 	_db_show_termios("\ttermios", &tp->t_termios);
2020 	db_printf("\twinsize: row %u col %u xpixel %u ypixel %u\n",
2021 	    tp->t_winsize.ws_row, tp->t_winsize.ws_col,
2022 	    tp->t_winsize.ws_xpixel, tp->t_winsize.ws_ypixel);
2023 	db_printf("\tcolumn: %u\n", tp->t_column);
2024 	db_printf("\twritepos: %u\n", tp->t_writepos);
2025 	db_printf("\tcompatflags: 0x%x\n", tp->t_compatflags);
2026 
2027 	/* Init/lock-state devices. */
2028 	_db_show_termios("\ttermios_init_in", &tp->t_termios_init_in);
2029 	_db_show_termios("\ttermios_init_out", &tp->t_termios_init_out);
2030 	_db_show_termios("\ttermios_lock_in", &tp->t_termios_lock_in);
2031 	_db_show_termios("\ttermios_lock_out", &tp->t_termios_lock_out);
2032 
2033 	/* Hooks */
2034 	_db_show_devsw("\t", tp->t_devsw);
2035 	_db_show_hooks("\t", tp->t_hook);
2036 
2037 	/* Process info. */
2038 	db_printf("\tpgrp: %p gid %d jobc %d\n", tp->t_pgrp,
2039 	    tp->t_pgrp ? tp->t_pgrp->pg_id : 0,
2040 	    tp->t_pgrp ? tp->t_pgrp->pg_jobc : 0);
2041 	db_printf("\tsession: %p", tp->t_session);
2042 	if (tp->t_session != NULL)
2043 	    db_printf(" count %u leader %p tty %p sid %d login %s",
2044 		tp->t_session->s_count, tp->t_session->s_leader,
2045 		tp->t_session->s_ttyp, tp->t_session->s_sid,
2046 		tp->t_session->s_login);
2047 	db_printf("\n");
2048 	db_printf("\tsessioncnt: %u\n", tp->t_sessioncnt);
2049 	db_printf("\tdevswsoftc: %p\n", tp->t_devswsoftc);
2050 	db_printf("\thooksoftc: %p\n", tp->t_hooksoftc);
2051 	db_printf("\tdev: %p\n", tp->t_dev);
2052 }
2053 
2054 /* DDB command to list TTYs. */
2055 DB_SHOW_ALL_COMMAND(ttys, db_show_all_ttys)
2056 {
2057 	struct tty *tp;
2058 	size_t isiz, osiz;
2059 	int i, j;
2060 
2061 	/* Make the output look like `pstat -t'. */
2062 	db_printf("PTR        ");
2063 #if defined(__LP64__)
2064 	db_printf("        ");
2065 #endif
2066 	db_printf("      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   "
2067 	    "COL  SESS  PGID STATE\n");
2068 
2069 	TAILQ_FOREACH(tp, &tty_list, t_list) {
2070 		isiz = tp->t_inq.ti_nblocks * TTYINQ_DATASIZE;
2071 		osiz = tp->t_outq.to_nblocks * TTYOUTQ_DATASIZE;
2072 
2073 		db_printf("%p %10s %5zu %4u %4u %4zu %5zu %4u %4zu %5u %5d %5d ",
2074 		    tp,
2075 		    tty_devname(tp),
2076 		    isiz,
2077 		    tp->t_inq.ti_linestart - tp->t_inq.ti_begin,
2078 		    tp->t_inq.ti_end - tp->t_inq.ti_linestart,
2079 		    isiz - tp->t_inlow,
2080 		    osiz,
2081 		    tp->t_outq.to_end - tp->t_outq.to_begin,
2082 		    osiz - tp->t_outlow,
2083 		    MIN(tp->t_column, 99999),
2084 		    tp->t_session ? tp->t_session->s_sid : 0,
2085 		    tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
2086 
2087 		/* Flag bits. */
2088 		for (i = j = 0; ttystates[i].flag; i++)
2089 			if (tp->t_flags & ttystates[i].flag) {
2090 				db_printf("%c", ttystates[i].val);
2091 				j++;
2092 			}
2093 		if (j == 0)
2094 			db_printf("-");
2095 		db_printf("\n");
2096 	}
2097 }
2098 #endif /* DDB */
2099