xref: /freebsd/sys/kern/tty.c (revision 71ccf09269546d398fa847168fc74c22d6338a62)
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 = 0;
106 
107 	/* Provide an input buffer for 0.2 seconds of data. */
108 	if (tp->t_termios.c_cflag & CREAD)
109 		bs = MIN(tp->t_termios.c_ispeed / 5, TTYBUF_MAX);
110 	ttyinq_setsize(&tp->t_inq, tp, bs);
111 
112 	/* Set low watermark at 10% (when 90% is available). */
113 	tp->t_inlow = (ttyinq_getallocatedsize(&tp->t_inq) * 9) / 10;
114 
115 	/* Provide an ouput buffer for 0.2 seconds of data. */
116 	bs = MIN(tp->t_termios.c_ospeed / 5, TTYBUF_MAX);
117 	ttyoutq_setsize(&tp->t_outq, tp, bs);
118 
119 	/* Set low watermark at 10% (when 90% is available). */
120 	tp->t_outlow = (ttyoutq_getallocatedsize(&tp->t_outq) * 9) / 10;
121 }
122 
123 static int
124 tty_drain(struct tty *tp)
125 {
126 	int error;
127 
128 	if (ttyhook_hashook(tp, getc_inject))
129 		/* buffer is inaccessible */
130 		return (0);
131 
132 	while (ttyoutq_bytesused(&tp->t_outq) > 0) {
133 		ttydevsw_outwakeup(tp);
134 		/* Could be handled synchronously. */
135 		if (ttyoutq_bytesused(&tp->t_outq) == 0)
136 			return (0);
137 
138 		/* Wait for data to be drained. */
139 		error = tty_wait(tp, &tp->t_outwait);
140 		if (error)
141 			return (error);
142 	}
143 
144 	return (0);
145 }
146 
147 /*
148  * Though ttydev_enter() and ttydev_leave() seem to be related, they
149  * don't have to be used together. ttydev_enter() is used by the cdev
150  * operations to prevent an actual operation from being processed when
151  * the TTY has been abandoned. ttydev_leave() is used by ttydev_open()
152  * and ttydev_close() to determine whether per-TTY data should be
153  * deallocated.
154  */
155 
156 static __inline int
157 ttydev_enter(struct tty *tp)
158 {
159 	tty_lock(tp);
160 
161 	if (tty_gone(tp) || !tty_opened(tp)) {
162 		/* Device is already gone. */
163 		tty_unlock(tp);
164 		return (ENXIO);
165 	}
166 
167 	return (0);
168 }
169 
170 static void
171 ttydev_leave(struct tty *tp)
172 {
173 	tty_lock_assert(tp, MA_OWNED);
174 
175 	if (tty_opened(tp) || tp->t_flags & TF_OPENCLOSE) {
176 		/* Device is still opened somewhere. */
177 		tty_unlock(tp);
178 		return;
179 	}
180 
181 	tp->t_flags |= TF_OPENCLOSE;
182 
183 	/* Stop asynchronous I/O. */
184 	funsetown(&tp->t_sigio);
185 
186 	/* Remove console TTY. */
187 	if (constty == tp)
188 		constty_clear();
189 
190 	/* Drain any output. */
191 	MPASS((tp->t_flags & TF_STOPPED) == 0);
192 	if (!tty_gone(tp))
193 		tty_drain(tp);
194 
195 	ttydisc_close(tp);
196 
197 	/* Destroy associated buffers already. */
198 	ttyinq_free(&tp->t_inq);
199 	tp->t_inlow = 0;
200 	ttyoutq_free(&tp->t_outq);
201 	tp->t_outlow = 0;
202 
203 	knlist_clear(&tp->t_inpoll.si_note, 1);
204 	knlist_clear(&tp->t_outpoll.si_note, 1);
205 
206 	if (!tty_gone(tp))
207 		ttydevsw_close(tp);
208 
209 	tp->t_flags &= ~TF_OPENCLOSE;
210 	cv_broadcast(&tp->t_dcdwait);
211 	tty_rel_free(tp);
212 }
213 
214 /*
215  * Operations that are exposed through the character device in /dev.
216  */
217 static int
218 ttydev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
219 {
220 	struct tty *tp = dev->si_drv1;
221 	int error = 0;
222 
223 	tty_lock(tp);
224 	if (tty_gone(tp)) {
225 		/* Device is already gone. */
226 		tty_unlock(tp);
227 		return (ENXIO);
228 	}
229 
230 	/*
231 	 * Block when other processes are currently opening or closing
232 	 * the TTY.
233 	 */
234 	while (tp->t_flags & TF_OPENCLOSE) {
235 		error = tty_wait(tp, &tp->t_dcdwait);
236 		if (error != 0) {
237 			tty_unlock(tp);
238 			return (error);
239 		}
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 (dev == dev_console)
294 		tp->t_flags |= TF_OPENED_CONS;
295 	else if (TTY_CALLOUT(tp, dev))
296 		tp->t_flags |= TF_OPENED_OUT;
297 	else
298 		tp->t_flags |= TF_OPENED_IN;
299 
300 done:	tp->t_flags &= ~TF_OPENCLOSE;
301 	cv_broadcast(&tp->t_dcdwait);
302 	ttydev_leave(tp);
303 
304 	return (error);
305 }
306 
307 static int
308 ttydev_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
309 {
310 	struct tty *tp = dev->si_drv1;
311 
312 	tty_lock(tp);
313 
314 	/*
315 	 * Don't actually close the device if it is being used as the
316 	 * console.
317 	 */
318 	MPASS((tp->t_flags & TF_OPENED) != TF_OPENED);
319 	if (dev == dev_console)
320 		tp->t_flags &= ~TF_OPENED_CONS;
321 	else
322 		tp->t_flags &= ~(TF_OPENED_IN|TF_OPENED_OUT);
323 
324 	if (tp->t_flags & TF_OPENED) {
325 		tty_unlock(tp);
326 		return (0);
327 	}
328 
329 	/*
330 	 * This can only be called once. The callin and the callout
331 	 * devices cannot be opened at the same time.
332 	 */
333 	tp->t_flags &= ~(TF_EXCLUDE|TF_STOPPED);
334 
335 	/* Properly wake up threads that are stuck - revoke(). */
336 	tp->t_revokecnt++;
337 	tty_wakeup(tp, FREAD|FWRITE);
338 	cv_broadcast(&tp->t_bgwait);
339 	cv_broadcast(&tp->t_dcdwait);
340 
341 	ttydev_leave(tp);
342 
343 	return (0);
344 }
345 
346 static __inline int
347 tty_is_ctty(struct tty *tp, struct proc *p)
348 {
349 	tty_lock_assert(tp, MA_OWNED);
350 
351 	return (p->p_session == tp->t_session && p->p_flag & P_CONTROLT);
352 }
353 
354 static int
355 tty_wait_background(struct tty *tp, struct thread *td, int sig)
356 {
357 	struct proc *p = td->td_proc;
358 	struct pgrp *pg;
359 	ksiginfo_t ksi;
360 	int error;
361 
362 	MPASS(sig == SIGTTIN || sig == SIGTTOU);
363 	tty_lock_assert(tp, MA_OWNED);
364 
365 	for (;;) {
366 		PROC_LOCK(p);
367 		/*
368 		 * The process should only sleep, when:
369 		 * - This terminal is the controling terminal
370 		 * - Its process group is not the foreground process
371 		 *   group
372 		 * - The parent process isn't waiting for the child to
373 		 *   exit
374 		 * - the signal to send to the process isn't masked
375 		 */
376 		if (!tty_is_ctty(tp, p) || p->p_pgrp == tp->t_pgrp) {
377 			/* Allow the action to happen. */
378 			PROC_UNLOCK(p);
379 			return (0);
380 		}
381 
382 		if (SIGISMEMBER(p->p_sigacts->ps_sigignore, sig) ||
383 		    SIGISMEMBER(td->td_sigmask, sig)) {
384 			/* Only allow them in write()/ioctl(). */
385 			PROC_UNLOCK(p);
386 			return (sig == SIGTTOU ? 0 : EIO);
387 		}
388 
389 		pg = p->p_pgrp;
390 		if (p->p_flag & P_PPWAIT || pg->pg_jobc == 0) {
391 			/* Don't allow the action to happen. */
392 			PROC_UNLOCK(p);
393 			return (EIO);
394 		}
395 		PROC_UNLOCK(p);
396 
397 		/*
398 		 * Send the signal and sleep until we're the new
399 		 * foreground process group.
400 		 */
401 		if (sig != 0) {
402 			ksiginfo_init(&ksi);
403 			ksi.ksi_code = SI_KERNEL;
404 			ksi.ksi_signo = sig;
405 			sig = 0;
406 		}
407 		PGRP_LOCK(pg);
408 		pgsignal(pg, ksi.ksi_signo, 1, &ksi);
409 		PGRP_UNLOCK(pg);
410 
411 		error = tty_wait(tp, &tp->t_bgwait);
412 		if (error)
413 			return (error);
414 	}
415 }
416 
417 static int
418 ttydev_read(struct cdev *dev, struct uio *uio, int ioflag)
419 {
420 	struct tty *tp = dev->si_drv1;
421 	int error;
422 
423 	error = ttydev_enter(tp);
424 	if (error)
425 		goto done;
426 
427 	error = tty_wait_background(tp, curthread, SIGTTIN);
428 	if (error) {
429 		tty_unlock(tp);
430 		goto done;
431 	}
432 
433 	error = ttydisc_read(tp, uio, ioflag);
434 	tty_unlock(tp);
435 
436 	/*
437 	 * The read() call should not throw an error when the device is
438 	 * being destroyed. Silently convert it to an EOF.
439 	 */
440 done:	if (error == ENXIO)
441 		error = 0;
442 	return (error);
443 }
444 
445 static int
446 ttydev_write(struct cdev *dev, struct uio *uio, int ioflag)
447 {
448 	struct tty *tp = dev->si_drv1;
449 	int error;
450 
451 	error = ttydev_enter(tp);
452 	if (error)
453 		return (error);
454 
455 	if (tp->t_termios.c_lflag & TOSTOP) {
456 		error = tty_wait_background(tp, curthread, SIGTTOU);
457 		if (error)
458 			goto done;
459 	}
460 
461 	if (ioflag & IO_NDELAY && tp->t_flags & TF_BUSY_OUT) {
462 		/* Allow non-blocking writes to bypass serialization. */
463 		error = ttydisc_write(tp, uio, ioflag);
464 	} else {
465 		/* Serialize write() calls. */
466 		while (tp->t_flags & TF_BUSY_OUT) {
467 			error = tty_wait(tp, &tp->t_outserwait);
468 			if (error)
469 				goto done;
470 		}
471 
472  		tp->t_flags |= TF_BUSY_OUT;
473 		error = ttydisc_write(tp, uio, ioflag);
474  		tp->t_flags &= ~TF_BUSY_OUT;
475 		cv_signal(&tp->t_outserwait);
476 	}
477 
478 done:	tty_unlock(tp);
479 	return (error);
480 }
481 
482 static int
483 ttydev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
484     struct thread *td)
485 {
486 	struct tty *tp = dev->si_drv1;
487 	int error;
488 
489 	error = ttydev_enter(tp);
490 	if (error)
491 		return (error);
492 
493 	switch (cmd) {
494 	case TIOCCBRK:
495 	case TIOCCONS:
496 	case TIOCDRAIN:
497 	case TIOCEXCL:
498 	case TIOCFLUSH:
499 	case TIOCNXCL:
500 	case TIOCSBRK:
501 	case TIOCSCTTY:
502 	case TIOCSETA:
503 	case TIOCSETAF:
504 	case TIOCSETAW:
505 	case TIOCSPGRP:
506 	case TIOCSTART:
507 	case TIOCSTAT:
508 	case TIOCSTOP:
509 	case TIOCSWINSZ:
510 #if 0
511 	case TIOCSDRAINWAIT:
512 	case TIOCSETD:
513 	case TIOCSTI:
514 #endif
515 #ifdef COMPAT_43TTY
516 	case  TIOCLBIC:
517 	case  TIOCLBIS:
518 	case  TIOCLSET:
519 	case  TIOCSETC:
520 	case OTIOCSETD:
521 	case  TIOCSETN:
522 	case  TIOCSETP:
523 	case  TIOCSLTC:
524 #endif /* COMPAT_43TTY */
525 		/*
526 		 * If the ioctl() causes the TTY to be modified, let it
527 		 * wait in the background.
528 		 */
529 		error = tty_wait_background(tp, curthread, SIGTTOU);
530 		if (error)
531 			goto done;
532 	}
533 
534 	if (cmd == TIOCSETA || cmd == TIOCSETAW || cmd == TIOCSETAF) {
535 		struct termios *old = &tp->t_termios;
536 		struct termios *new = (struct termios *)data;
537 		struct termios *lock = TTY_CALLOUT(tp, dev) ?
538 		    &tp->t_termios_lock_out : &tp->t_termios_lock_in;
539 		int cc;
540 
541 		/*
542 		 * Lock state devices.  Just overwrite the values of the
543 		 * commands that are currently in use.
544 		 */
545 		new->c_iflag = (old->c_iflag & lock->c_iflag) |
546 		    (new->c_iflag & ~lock->c_iflag);
547 		new->c_oflag = (old->c_oflag & lock->c_oflag) |
548 		    (new->c_oflag & ~lock->c_oflag);
549 		new->c_cflag = (old->c_cflag & lock->c_cflag) |
550 		    (new->c_cflag & ~lock->c_cflag);
551 		new->c_lflag = (old->c_lflag & lock->c_lflag) |
552 		    (new->c_lflag & ~lock->c_lflag);
553 		for (cc = 0; cc < NCCS; ++cc)
554 			if (lock->c_cc[cc])
555 				new->c_cc[cc] = old->c_cc[cc];
556 		if (lock->c_ispeed)
557 			new->c_ispeed = old->c_ispeed;
558 		if (lock->c_ospeed)
559 			new->c_ospeed = old->c_ospeed;
560 	}
561 
562 	error = tty_ioctl(tp, cmd, data, td);
563 done:	tty_unlock(tp);
564 
565 	return (error);
566 }
567 
568 static int
569 ttydev_poll(struct cdev *dev, int events, struct thread *td)
570 {
571 	struct tty *tp = dev->si_drv1;
572 	int error, revents = 0;
573 
574 	error = ttydev_enter(tp);
575 	if (error)
576 		return ((events & (POLLIN|POLLRDNORM)) | POLLHUP);
577 
578 	if (events & (POLLIN|POLLRDNORM)) {
579 		/* See if we can read something. */
580 		if (ttydisc_read_poll(tp) > 0)
581 			revents |= events & (POLLIN|POLLRDNORM);
582 	}
583 
584 	if (tp->t_flags & TF_ZOMBIE) {
585 		/* Hangup flag on zombie state. */
586 		revents |= POLLHUP;
587 	} else if (events & (POLLOUT|POLLWRNORM)) {
588 		/* See if we can write something. */
589 		if (ttydisc_write_poll(tp) > 0)
590 			revents |= events & (POLLOUT|POLLWRNORM);
591 	}
592 
593 	if (revents == 0) {
594 		if (events & (POLLIN|POLLRDNORM))
595 			selrecord(td, &tp->t_inpoll);
596 		if (events & (POLLOUT|POLLWRNORM))
597 			selrecord(td, &tp->t_outpoll);
598 	}
599 
600 	tty_unlock(tp);
601 
602 	return (revents);
603 }
604 
605 static int
606 ttydev_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
607     int nprot, vm_memattr_t *memattr)
608 {
609 	struct tty *tp = dev->si_drv1;
610 	int error;
611 
612 	/* Handle mmap() through the driver. */
613 
614 	error = ttydev_enter(tp);
615 	if (error)
616 		return (-1);
617 	error = ttydevsw_mmap(tp, offset, paddr, nprot, memattr);
618 	tty_unlock(tp);
619 
620 	return (error);
621 }
622 
623 /*
624  * kqueue support.
625  */
626 
627 static void
628 tty_kqops_read_detach(struct knote *kn)
629 {
630 	struct tty *tp = kn->kn_hook;
631 
632 	knlist_remove(&tp->t_inpoll.si_note, kn, 0);
633 }
634 
635 static int
636 tty_kqops_read_event(struct knote *kn, long hint)
637 {
638 	struct tty *tp = kn->kn_hook;
639 
640 	tty_lock_assert(tp, MA_OWNED);
641 
642 	if (tty_gone(tp) || tp->t_flags & TF_ZOMBIE) {
643 		kn->kn_flags |= EV_EOF;
644 		return (1);
645 	} else {
646 		kn->kn_data = ttydisc_read_poll(tp);
647 		return (kn->kn_data > 0);
648 	}
649 }
650 
651 static void
652 tty_kqops_write_detach(struct knote *kn)
653 {
654 	struct tty *tp = kn->kn_hook;
655 
656 	knlist_remove(&tp->t_outpoll.si_note, kn, 0);
657 }
658 
659 static int
660 tty_kqops_write_event(struct knote *kn, long hint)
661 {
662 	struct tty *tp = kn->kn_hook;
663 
664 	tty_lock_assert(tp, MA_OWNED);
665 
666 	if (tty_gone(tp)) {
667 		kn->kn_flags |= EV_EOF;
668 		return (1);
669 	} else {
670 		kn->kn_data = ttydisc_write_poll(tp);
671 		return (kn->kn_data > 0);
672 	}
673 }
674 
675 static struct filterops tty_kqops_read = {
676 	.f_isfd = 1,
677 	.f_detach = tty_kqops_read_detach,
678 	.f_event = tty_kqops_read_event,
679 };
680 static struct filterops tty_kqops_write = {
681 	.f_isfd = 1,
682 	.f_detach = tty_kqops_write_detach,
683 	.f_event = tty_kqops_write_event,
684 };
685 
686 static int
687 ttydev_kqfilter(struct cdev *dev, struct knote *kn)
688 {
689 	struct tty *tp = dev->si_drv1;
690 	int error;
691 
692 	error = ttydev_enter(tp);
693 	if (error)
694 		return (error);
695 
696 	switch (kn->kn_filter) {
697 	case EVFILT_READ:
698 		kn->kn_hook = tp;
699 		kn->kn_fop = &tty_kqops_read;
700 		knlist_add(&tp->t_inpoll.si_note, kn, 1);
701 		break;
702 	case EVFILT_WRITE:
703 		kn->kn_hook = tp;
704 		kn->kn_fop = &tty_kqops_write;
705 		knlist_add(&tp->t_outpoll.si_note, kn, 1);
706 		break;
707 	default:
708 		error = EINVAL;
709 		break;
710 	}
711 
712 	tty_unlock(tp);
713 	return (error);
714 }
715 
716 static struct cdevsw ttydev_cdevsw = {
717 	.d_version	= D_VERSION,
718 	.d_open		= ttydev_open,
719 	.d_close	= ttydev_close,
720 	.d_read		= ttydev_read,
721 	.d_write	= ttydev_write,
722 	.d_ioctl	= ttydev_ioctl,
723 	.d_kqfilter	= ttydev_kqfilter,
724 	.d_poll		= ttydev_poll,
725 	.d_mmap		= ttydev_mmap,
726 	.d_name		= "ttydev",
727 	.d_flags	= D_TTY,
728 };
729 
730 /*
731  * Init/lock-state devices
732  */
733 
734 static int
735 ttyil_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
736 {
737 	struct tty *tp = dev->si_drv1;
738 	int error = 0;
739 
740 	tty_lock(tp);
741 	if (tty_gone(tp))
742 		error = ENODEV;
743 	tty_unlock(tp);
744 
745 	return (error);
746 }
747 
748 static int
749 ttyil_close(struct cdev *dev, int flag, int mode, struct thread *td)
750 {
751 	return (0);
752 }
753 
754 static int
755 ttyil_rdwr(struct cdev *dev, struct uio *uio, int ioflag)
756 {
757 	return (ENODEV);
758 }
759 
760 static int
761 ttyil_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
762     struct thread *td)
763 {
764 	struct tty *tp = dev->si_drv1;
765 	int error = 0;
766 
767 	tty_lock(tp);
768 	if (tty_gone(tp)) {
769 		error = ENODEV;
770 		goto done;
771 	}
772 
773 	switch (cmd) {
774 	case TIOCGETA:
775 		/* Obtain terminal flags through tcgetattr(). */
776 		*(struct termios*)data = *(struct termios*)dev->si_drv2;
777 		break;
778 	case TIOCSETA:
779 		/* Set terminal flags through tcsetattr(). */
780 		error = priv_check(td, PRIV_TTY_SETA);
781 		if (error)
782 			break;
783 		*(struct termios*)dev->si_drv2 = *(struct termios*)data;
784 		break;
785 	case TIOCGETD:
786 		*(int *)data = TTYDISC;
787 		break;
788 	case TIOCGWINSZ:
789 		bzero(data, sizeof(struct winsize));
790 		break;
791 	default:
792 		error = ENOTTY;
793 	}
794 
795 done:	tty_unlock(tp);
796 	return (error);
797 }
798 
799 static struct cdevsw ttyil_cdevsw = {
800 	.d_version	= D_VERSION,
801 	.d_open		= ttyil_open,
802 	.d_close	= ttyil_close,
803 	.d_read		= ttyil_rdwr,
804 	.d_write	= ttyil_rdwr,
805 	.d_ioctl	= ttyil_ioctl,
806 	.d_name		= "ttyil",
807 	.d_flags	= D_TTY,
808 };
809 
810 static void
811 tty_init_termios(struct tty *tp)
812 {
813 	struct termios *t = &tp->t_termios_init_in;
814 
815 	t->c_cflag = TTYDEF_CFLAG;
816 	t->c_iflag = TTYDEF_IFLAG;
817 	t->c_lflag = TTYDEF_LFLAG;
818 	t->c_oflag = TTYDEF_OFLAG;
819 	t->c_ispeed = TTYDEF_SPEED;
820 	t->c_ospeed = TTYDEF_SPEED;
821 	memcpy(&t->c_cc, ttydefchars, sizeof ttydefchars);
822 
823 	tp->t_termios_init_out = *t;
824 }
825 
826 void
827 tty_init_console(struct tty *tp, speed_t s)
828 {
829 	struct termios *ti = &tp->t_termios_init_in;
830 	struct termios *to = &tp->t_termios_init_out;
831 
832 	if (s != 0) {
833 		ti->c_ispeed = ti->c_ospeed = s;
834 		to->c_ispeed = to->c_ospeed = s;
835 	}
836 
837 	ti->c_cflag |= CLOCAL;
838 	to->c_cflag |= CLOCAL;
839 }
840 
841 /*
842  * Standard device routine implementations, mostly meant for
843  * pseudo-terminal device drivers. When a driver creates a new terminal
844  * device class, missing routines are patched.
845  */
846 
847 static int
848 ttydevsw_defopen(struct tty *tp)
849 {
850 
851 	return (0);
852 }
853 
854 static void
855 ttydevsw_defclose(struct tty *tp)
856 {
857 }
858 
859 static void
860 ttydevsw_defoutwakeup(struct tty *tp)
861 {
862 
863 	panic("Terminal device has output, while not implemented");
864 }
865 
866 static void
867 ttydevsw_definwakeup(struct tty *tp)
868 {
869 }
870 
871 static int
872 ttydevsw_defioctl(struct tty *tp, u_long cmd, caddr_t data, struct thread *td)
873 {
874 
875 	return (ENOIOCTL);
876 }
877 
878 static int
879 ttydevsw_defparam(struct tty *tp, struct termios *t)
880 {
881 
882 	/*
883 	 * Allow the baud rate to be adjusted for pseudo-devices, but at
884 	 * least restrict it to 115200 to prevent excessive buffer
885 	 * usage.  Also disallow 0, to prevent foot shooting.
886 	 */
887 	if (t->c_ispeed < B50)
888 		t->c_ispeed = B50;
889 	else if (t->c_ispeed > B115200)
890 		t->c_ispeed = B115200;
891 	if (t->c_ospeed < B50)
892 		t->c_ospeed = B50;
893 	else if (t->c_ospeed > B115200)
894 		t->c_ospeed = B115200;
895 	t->c_cflag |= CREAD;
896 
897 	return (0);
898 }
899 
900 static int
901 ttydevsw_defmodem(struct tty *tp, int sigon, int sigoff)
902 {
903 
904 	/* Simulate a carrier to make the TTY layer happy. */
905 	return (SER_DCD);
906 }
907 
908 static int
909 ttydevsw_defmmap(struct tty *tp, vm_ooffset_t offset, vm_paddr_t *paddr,
910     int nprot, vm_memattr_t *memattr)
911 {
912 
913 	return (-1);
914 }
915 
916 static void
917 ttydevsw_defpktnotify(struct tty *tp, char event)
918 {
919 }
920 
921 static void
922 ttydevsw_deffree(void *softc)
923 {
924 
925 	panic("Terminal device freed without a free-handler");
926 }
927 
928 /*
929  * TTY allocation and deallocation. TTY devices can be deallocated when
930  * the driver doesn't use it anymore, when the TTY isn't a session's
931  * controlling TTY and when the device node isn't opened through devfs.
932  */
933 
934 struct tty *
935 tty_alloc(struct ttydevsw *tsw, void *sc)
936 {
937 
938 	return (tty_alloc_mutex(tsw, sc, NULL));
939 }
940 
941 struct tty *
942 tty_alloc_mutex(struct ttydevsw *tsw, void *sc, struct mtx *mutex)
943 {
944 	struct tty *tp;
945 
946 	/* Make sure the driver defines all routines. */
947 #define PATCH_FUNC(x) do {				\
948 	if (tsw->tsw_ ## x == NULL)			\
949 		tsw->tsw_ ## x = ttydevsw_def ## x;	\
950 } while (0)
951 	PATCH_FUNC(open);
952 	PATCH_FUNC(close);
953 	PATCH_FUNC(outwakeup);
954 	PATCH_FUNC(inwakeup);
955 	PATCH_FUNC(ioctl);
956 	PATCH_FUNC(param);
957 	PATCH_FUNC(modem);
958 	PATCH_FUNC(mmap);
959 	PATCH_FUNC(pktnotify);
960 	PATCH_FUNC(free);
961 #undef PATCH_FUNC
962 
963 	tp = malloc(sizeof(struct tty), M_TTY, M_WAITOK|M_ZERO);
964 	tp->t_devsw = tsw;
965 	tp->t_devswsoftc = sc;
966 	tp->t_flags = tsw->tsw_flags;
967 
968 	tty_init_termios(tp);
969 
970 	cv_init(&tp->t_inwait, "ttyin");
971 	cv_init(&tp->t_outwait, "ttyout");
972 	cv_init(&tp->t_outserwait, "ttyosr");
973 	cv_init(&tp->t_bgwait, "ttybg");
974 	cv_init(&tp->t_dcdwait, "ttydcd");
975 
976 	/* Allow drivers to use a custom mutex to lock the TTY. */
977 	if (mutex != NULL) {
978 		tp->t_mtx = mutex;
979 	} else {
980 		tp->t_mtx = &tp->t_mtxobj;
981 		mtx_init(&tp->t_mtxobj, "ttymtx", NULL, MTX_DEF);
982 	}
983 
984 	knlist_init_mtx(&tp->t_inpoll.si_note, tp->t_mtx);
985 	knlist_init_mtx(&tp->t_outpoll.si_note, tp->t_mtx);
986 
987 	sx_xlock(&tty_list_sx);
988 	TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
989 	tty_list_count++;
990 	sx_xunlock(&tty_list_sx);
991 
992 	return (tp);
993 }
994 
995 static void
996 tty_dealloc(void *arg)
997 {
998 	struct tty *tp = arg;
999 
1000 	sx_xlock(&tty_list_sx);
1001 	TAILQ_REMOVE(&tty_list, tp, t_list);
1002 	tty_list_count--;
1003 	sx_xunlock(&tty_list_sx);
1004 
1005 	/* Make sure we haven't leaked buffers. */
1006 	MPASS(ttyinq_getsize(&tp->t_inq) == 0);
1007 	MPASS(ttyoutq_getsize(&tp->t_outq) == 0);
1008 
1009 	knlist_destroy(&tp->t_inpoll.si_note);
1010 	knlist_destroy(&tp->t_outpoll.si_note);
1011 
1012 	cv_destroy(&tp->t_inwait);
1013 	cv_destroy(&tp->t_outwait);
1014 	cv_destroy(&tp->t_bgwait);
1015 	cv_destroy(&tp->t_dcdwait);
1016 	cv_destroy(&tp->t_outserwait);
1017 
1018 	if (tp->t_mtx == &tp->t_mtxobj)
1019 		mtx_destroy(&tp->t_mtxobj);
1020 	ttydevsw_free(tp);
1021 	free(tp, M_TTY);
1022 }
1023 
1024 static void
1025 tty_rel_free(struct tty *tp)
1026 {
1027 	struct cdev *dev;
1028 
1029 	tty_lock_assert(tp, MA_OWNED);
1030 
1031 #define	TF_ACTIVITY	(TF_GONE|TF_OPENED|TF_HOOK|TF_OPENCLOSE)
1032 	if (tp->t_sessioncnt != 0 || (tp->t_flags & TF_ACTIVITY) != TF_GONE) {
1033 		/* TTY is still in use. */
1034 		tty_unlock(tp);
1035 		return;
1036 	}
1037 
1038 	/* TTY can be deallocated. */
1039 	dev = tp->t_dev;
1040 	tp->t_dev = NULL;
1041 	tty_unlock(tp);
1042 
1043 	destroy_dev_sched_cb(dev, tty_dealloc, tp);
1044 }
1045 
1046 void
1047 tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
1048 {
1049 	MPASS(tp->t_sessioncnt > 0);
1050 	tty_lock_assert(tp, MA_OWNED);
1051 
1052 	if (tp->t_pgrp == pg)
1053 		tp->t_pgrp = NULL;
1054 
1055 	tty_unlock(tp);
1056 }
1057 
1058 void
1059 tty_rel_sess(struct tty *tp, struct session *sess)
1060 {
1061 	MPASS(tp->t_sessioncnt > 0);
1062 
1063 	/* Current session has left. */
1064 	if (tp->t_session == sess) {
1065 		tp->t_session = NULL;
1066 		MPASS(tp->t_pgrp == NULL);
1067 	}
1068 	tp->t_sessioncnt--;
1069 	tty_rel_free(tp);
1070 }
1071 
1072 void
1073 tty_rel_gone(struct tty *tp)
1074 {
1075 	MPASS(!tty_gone(tp));
1076 
1077 	/* Simulate carrier removal. */
1078 	ttydisc_modem(tp, 0);
1079 
1080 	/* Wake up all blocked threads. */
1081 	tty_wakeup(tp, FREAD|FWRITE);
1082 	cv_broadcast(&tp->t_bgwait);
1083 	cv_broadcast(&tp->t_dcdwait);
1084 
1085 	tp->t_flags |= TF_GONE;
1086 	tty_rel_free(tp);
1087 }
1088 
1089 /*
1090  * Exposing information about current TTY's through sysctl
1091  */
1092 
1093 static void
1094 tty_to_xtty(struct tty *tp, struct xtty *xt)
1095 {
1096 	tty_lock_assert(tp, MA_OWNED);
1097 
1098 	xt->xt_size = sizeof(struct xtty);
1099 	xt->xt_insize = ttyinq_getsize(&tp->t_inq);
1100 	xt->xt_incc = ttyinq_bytescanonicalized(&tp->t_inq);
1101 	xt->xt_inlc = ttyinq_bytesline(&tp->t_inq);
1102 	xt->xt_inlow = tp->t_inlow;
1103 	xt->xt_outsize = ttyoutq_getsize(&tp->t_outq);
1104 	xt->xt_outcc = ttyoutq_bytesused(&tp->t_outq);
1105 	xt->xt_outlow = tp->t_outlow;
1106 	xt->xt_column = tp->t_column;
1107 	xt->xt_pgid = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
1108 	xt->xt_sid = tp->t_session ? tp->t_session->s_sid : 0;
1109 	xt->xt_flags = tp->t_flags;
1110 	xt->xt_dev = tp->t_dev ? dev2udev(tp->t_dev) : NODEV;
1111 }
1112 
1113 static int
1114 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
1115 {
1116 	unsigned long lsize;
1117 	struct xtty *xtlist, *xt;
1118 	struct tty *tp;
1119 	int error;
1120 
1121 	sx_slock(&tty_list_sx);
1122 	lsize = tty_list_count * sizeof(struct xtty);
1123 	if (lsize == 0) {
1124 		sx_sunlock(&tty_list_sx);
1125 		return (0);
1126 	}
1127 
1128 	xtlist = xt = malloc(lsize, M_TTY, M_WAITOK);
1129 
1130 	TAILQ_FOREACH(tp, &tty_list, t_list) {
1131 		tty_lock(tp);
1132 		tty_to_xtty(tp, xt);
1133 		tty_unlock(tp);
1134 		xt++;
1135 	}
1136 	sx_sunlock(&tty_list_sx);
1137 
1138 	error = SYSCTL_OUT(req, xtlist, lsize);
1139 	free(xtlist, M_TTY);
1140 	return (error);
1141 }
1142 
1143 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
1144 	0, 0, sysctl_kern_ttys, "S,xtty", "List of TTYs");
1145 
1146 /*
1147  * Device node creation. Device has been set up, now we can expose it to
1148  * the user.
1149  */
1150 
1151 void
1152 tty_makedev(struct tty *tp, struct ucred *cred, const char *fmt, ...)
1153 {
1154 	va_list ap;
1155 	struct cdev *dev;
1156 	const char *prefix = "tty";
1157 	char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
1158 	uid_t uid;
1159 	gid_t gid;
1160 	mode_t mode;
1161 
1162 	/* Remove "tty" prefix from devices like PTY's. */
1163 	if (tp->t_flags & TF_NOPREFIX)
1164 		prefix = "";
1165 
1166 	va_start(ap, fmt);
1167 	vsnrprintf(name, sizeof name, 32, fmt, ap);
1168 	va_end(ap);
1169 
1170 	if (cred == NULL) {
1171 		/* System device. */
1172 		uid = UID_ROOT;
1173 		gid = GID_WHEEL;
1174 		mode = S_IRUSR|S_IWUSR;
1175 	} else {
1176 		/* User device. */
1177 		uid = cred->cr_ruid;
1178 		gid = GID_TTY;
1179 		mode = S_IRUSR|S_IWUSR|S_IWGRP;
1180 	}
1181 
1182 	/* Master call-in device. */
1183 	dev = make_dev_cred(&ttydev_cdevsw, 0, cred,
1184 	    uid, gid, mode, "%s%s", prefix, name);
1185 	dev->si_drv1 = tp;
1186 	tp->t_dev = dev;
1187 
1188 	/* Slave call-in devices. */
1189 	if (tp->t_flags & TF_INITLOCK) {
1190 		dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1191 		    uid, gid, mode, "%s%s.init", prefix, name);
1192 		dev_depends(tp->t_dev, dev);
1193 		dev->si_drv1 = tp;
1194 		dev->si_drv2 = &tp->t_termios_init_in;
1195 
1196 		dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1197 		    uid, gid, mode, "%s%s.lock", prefix, name);
1198 		dev_depends(tp->t_dev, dev);
1199 		dev->si_drv1 = tp;
1200 		dev->si_drv2 = &tp->t_termios_lock_in;
1201 	}
1202 
1203 	/* Call-out devices. */
1204 	if (tp->t_flags & TF_CALLOUT) {
1205 		dev = make_dev_cred(&ttydev_cdevsw, 0, cred,
1206 		    UID_UUCP, GID_DIALER, 0660, "cua%s", name);
1207 		dev_depends(tp->t_dev, dev);
1208 		dev->si_drv1 = tp;
1209 
1210 		/* Slave call-out devices. */
1211 		if (tp->t_flags & TF_INITLOCK) {
1212 			dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1213 			    UID_UUCP, GID_DIALER, 0660, "cua%s.init", name);
1214 			dev_depends(tp->t_dev, dev);
1215 			dev->si_drv1 = tp;
1216 			dev->si_drv2 = &tp->t_termios_init_out;
1217 
1218 			dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1219 			    UID_UUCP, GID_DIALER, 0660, "cua%s.lock", name);
1220 			dev_depends(tp->t_dev, dev);
1221 			dev->si_drv1 = tp;
1222 			dev->si_drv2 = &tp->t_termios_lock_out;
1223 		}
1224 	}
1225 }
1226 
1227 /*
1228  * Signalling processes.
1229  */
1230 
1231 void
1232 tty_signal_sessleader(struct tty *tp, int sig)
1233 {
1234 	struct proc *p;
1235 
1236 	tty_lock_assert(tp, MA_OWNED);
1237 	MPASS(sig >= 1 && sig < NSIG);
1238 
1239 	/* Make signals start output again. */
1240 	tp->t_flags &= ~TF_STOPPED;
1241 
1242 	if (tp->t_session != NULL && tp->t_session->s_leader != NULL) {
1243 		p = tp->t_session->s_leader;
1244 		PROC_LOCK(p);
1245 		psignal(p, sig);
1246 		PROC_UNLOCK(p);
1247 	}
1248 }
1249 
1250 void
1251 tty_signal_pgrp(struct tty *tp, int sig)
1252 {
1253 	ksiginfo_t ksi;
1254 
1255 	tty_lock_assert(tp, MA_OWNED);
1256 	MPASS(sig >= 1 && sig < NSIG);
1257 
1258 	/* Make signals start output again. */
1259 	tp->t_flags &= ~TF_STOPPED;
1260 
1261 	if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
1262 		tty_info(tp);
1263 	if (tp->t_pgrp != NULL) {
1264 		ksiginfo_init(&ksi);
1265 		ksi.ksi_signo = sig;
1266 		ksi.ksi_code = SI_KERNEL;
1267 		PGRP_LOCK(tp->t_pgrp);
1268 		pgsignal(tp->t_pgrp, sig, 1, &ksi);
1269 		PGRP_UNLOCK(tp->t_pgrp);
1270 	}
1271 }
1272 
1273 void
1274 tty_wakeup(struct tty *tp, int flags)
1275 {
1276 	if (tp->t_flags & TF_ASYNC && tp->t_sigio != NULL)
1277 		pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
1278 
1279 	if (flags & FWRITE) {
1280 		cv_broadcast(&tp->t_outwait);
1281 		selwakeup(&tp->t_outpoll);
1282 		KNOTE_LOCKED(&tp->t_outpoll.si_note, 0);
1283 	}
1284 	if (flags & FREAD) {
1285 		cv_broadcast(&tp->t_inwait);
1286 		selwakeup(&tp->t_inpoll);
1287 		KNOTE_LOCKED(&tp->t_inpoll.si_note, 0);
1288 	}
1289 }
1290 
1291 int
1292 tty_wait(struct tty *tp, struct cv *cv)
1293 {
1294 	int error;
1295 	int revokecnt = tp->t_revokecnt;
1296 
1297 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1298 	MPASS(!tty_gone(tp));
1299 
1300 	error = cv_wait_sig(cv, tp->t_mtx);
1301 
1302 	/* Restart the system call when we may have been revoked. */
1303 	if (tp->t_revokecnt != revokecnt)
1304 		return (ERESTART);
1305 
1306 	/* Bail out when the device slipped away. */
1307 	if (tty_gone(tp))
1308 		return (ENXIO);
1309 
1310 	return (error);
1311 }
1312 
1313 int
1314 tty_timedwait(struct tty *tp, struct cv *cv, int hz)
1315 {
1316 	int error;
1317 	int revokecnt = tp->t_revokecnt;
1318 
1319 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1320 	MPASS(!tty_gone(tp));
1321 
1322 	error = cv_timedwait_sig(cv, tp->t_mtx, hz);
1323 
1324 	/* Restart the system call when we may have been revoked. */
1325 	if (tp->t_revokecnt != revokecnt)
1326 		return (ERESTART);
1327 
1328 	/* Bail out when the device slipped away. */
1329 	if (tty_gone(tp))
1330 		return (ENXIO);
1331 
1332 	return (error);
1333 }
1334 
1335 void
1336 tty_flush(struct tty *tp, int flags)
1337 {
1338 	if (flags & FWRITE) {
1339 		tp->t_flags &= ~TF_HIWAT_OUT;
1340 		ttyoutq_flush(&tp->t_outq);
1341 		tty_wakeup(tp, FWRITE);
1342 		ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
1343 	}
1344 	if (flags & FREAD) {
1345 		tty_hiwat_in_unblock(tp);
1346 		ttyinq_flush(&tp->t_inq);
1347 		ttydevsw_inwakeup(tp);
1348 		ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
1349 	}
1350 }
1351 
1352 static int
1353 tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, struct thread *td)
1354 {
1355 	int error;
1356 
1357 	switch (cmd) {
1358 	/*
1359 	 * Modem commands.
1360 	 * The SER_* and TIOCM_* flags are the same, but one bit
1361 	 * shifted. I don't know why.
1362 	 */
1363 	case TIOCSDTR:
1364 		ttydevsw_modem(tp, SER_DTR, 0);
1365 		return (0);
1366 	case TIOCCDTR:
1367 		ttydevsw_modem(tp, 0, SER_DTR);
1368 		return (0);
1369 	case TIOCMSET: {
1370 		int bits = *(int *)data;
1371 		ttydevsw_modem(tp,
1372 		    (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1,
1373 		    ((~bits) & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1374 		return (0);
1375 	}
1376 	case TIOCMBIS: {
1377 		int bits = *(int *)data;
1378 		ttydevsw_modem(tp, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1, 0);
1379 		return (0);
1380 	}
1381 	case TIOCMBIC: {
1382 		int bits = *(int *)data;
1383 		ttydevsw_modem(tp, 0, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1384 		return (0);
1385 	}
1386 	case TIOCMGET:
1387 		*(int *)data = TIOCM_LE + (ttydevsw_modem(tp, 0, 0) << 1);
1388 		return (0);
1389 
1390 	case FIOASYNC:
1391 		if (*(int *)data)
1392 			tp->t_flags |= TF_ASYNC;
1393 		else
1394 			tp->t_flags &= ~TF_ASYNC;
1395 		return (0);
1396 	case FIONBIO:
1397 		/* This device supports non-blocking operation. */
1398 		return (0);
1399 	case FIONREAD:
1400 		*(int *)data = ttyinq_bytescanonicalized(&tp->t_inq);
1401 		return (0);
1402 	case FIONWRITE:
1403 	case TIOCOUTQ:
1404 		*(int *)data = ttyoutq_bytesused(&tp->t_outq);
1405 		return (0);
1406 	case FIOSETOWN:
1407 		if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1408 			/* Not allowed to set ownership. */
1409 			return (ENOTTY);
1410 
1411 		/* Temporarily unlock the TTY to set ownership. */
1412 		tty_unlock(tp);
1413 		error = fsetown(*(int *)data, &tp->t_sigio);
1414 		tty_lock(tp);
1415 		return (error);
1416 	case FIOGETOWN:
1417 		if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1418 			/* Not allowed to set ownership. */
1419 			return (ENOTTY);
1420 
1421 		/* Get ownership. */
1422 		*(int *)data = fgetown(&tp->t_sigio);
1423 		return (0);
1424 	case TIOCGETA:
1425 		/* Obtain terminal flags through tcgetattr(). */
1426 		*(struct termios*)data = tp->t_termios;
1427 		return (0);
1428 	case TIOCSETA:
1429 	case TIOCSETAW:
1430 	case TIOCSETAF: {
1431 		struct termios *t = data;
1432 
1433 		/*
1434 		 * Who makes up these funny rules? According to POSIX,
1435 		 * input baud rate is set equal to the output baud rate
1436 		 * when zero.
1437 		 */
1438 		if (t->c_ispeed == 0)
1439 			t->c_ispeed = t->c_ospeed;
1440 
1441 		/* Discard any unsupported bits. */
1442 		t->c_iflag &= TTYSUP_IFLAG;
1443 		t->c_oflag &= TTYSUP_OFLAG;
1444 		t->c_lflag &= TTYSUP_LFLAG;
1445 		t->c_cflag &= TTYSUP_CFLAG;
1446 
1447 		/* Set terminal flags through tcsetattr(). */
1448 		if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
1449 			error = tty_drain(tp);
1450 			if (error)
1451 				return (error);
1452 			if (cmd == TIOCSETAF)
1453 				tty_flush(tp, FREAD);
1454 		}
1455 
1456 		/*
1457 		 * Only call param() when the flags really change.
1458 		 */
1459 		if ((t->c_cflag & CIGNORE) == 0 &&
1460 		    (tp->t_termios.c_cflag != t->c_cflag ||
1461 		    tp->t_termios.c_ispeed != t->c_ispeed ||
1462 		    tp->t_termios.c_ospeed != t->c_ospeed)) {
1463 			error = ttydevsw_param(tp, t);
1464 			if (error)
1465 				return (error);
1466 
1467 			/* XXX: CLOCAL? */
1468 
1469 			tp->t_termios.c_cflag = t->c_cflag & ~CIGNORE;
1470 			tp->t_termios.c_ispeed = t->c_ispeed;
1471 			tp->t_termios.c_ospeed = t->c_ospeed;
1472 
1473 			/* Baud rate has changed - update watermarks. */
1474 			tty_watermarks(tp);
1475 		}
1476 
1477 		/* Copy new non-device driver parameters. */
1478 		tp->t_termios.c_iflag = t->c_iflag;
1479 		tp->t_termios.c_oflag = t->c_oflag;
1480 		tp->t_termios.c_lflag = t->c_lflag;
1481 		memcpy(&tp->t_termios.c_cc, t->c_cc, sizeof t->c_cc);
1482 
1483 		ttydisc_optimize(tp);
1484 
1485 		if ((t->c_lflag & ICANON) == 0) {
1486 			/*
1487 			 * When in non-canonical mode, wake up all
1488 			 * readers. Canonicalize any partial input. VMIN
1489 			 * and VTIME could also be adjusted.
1490 			 */
1491 			ttyinq_canonicalize(&tp->t_inq);
1492 			tty_wakeup(tp, FREAD);
1493 		}
1494 
1495 		/*
1496 		 * For packet mode: notify the PTY consumer that VSTOP
1497 		 * and VSTART may have been changed.
1498 		 */
1499 		if (tp->t_termios.c_iflag & IXON &&
1500 		    tp->t_termios.c_cc[VSTOP] == CTRL('S') &&
1501 		    tp->t_termios.c_cc[VSTART] == CTRL('Q'))
1502 			ttydevsw_pktnotify(tp, TIOCPKT_DOSTOP);
1503 		else
1504 			ttydevsw_pktnotify(tp, TIOCPKT_NOSTOP);
1505 		return (0);
1506 	}
1507 	case TIOCGETD:
1508 		/* For compatibility - we only support TTYDISC. */
1509 		*(int *)data = TTYDISC;
1510 		return (0);
1511 	case TIOCGPGRP:
1512 		if (!tty_is_ctty(tp, td->td_proc))
1513 			return (ENOTTY);
1514 
1515 		if (tp->t_pgrp != NULL)
1516 			*(int *)data = tp->t_pgrp->pg_id;
1517 		else
1518 			*(int *)data = NO_PID;
1519 		return (0);
1520 	case TIOCGSID:
1521 		if (!tty_is_ctty(tp, td->td_proc))
1522 			return (ENOTTY);
1523 
1524 		MPASS(tp->t_session);
1525 		*(int *)data = tp->t_session->s_sid;
1526 		return (0);
1527 	case TIOCSCTTY: {
1528 		struct proc *p = td->td_proc;
1529 
1530 		/* XXX: This looks awful. */
1531 		tty_unlock(tp);
1532 		sx_xlock(&proctree_lock);
1533 		tty_lock(tp);
1534 
1535 		if (!SESS_LEADER(p)) {
1536 			/* Only the session leader may do this. */
1537 			sx_xunlock(&proctree_lock);
1538 			return (EPERM);
1539 		}
1540 
1541 		if (tp->t_session != NULL && tp->t_session == p->p_session) {
1542 			/* This is already our controlling TTY. */
1543 			sx_xunlock(&proctree_lock);
1544 			return (0);
1545 		}
1546 
1547 		if (p->p_session->s_ttyp != NULL ||
1548 		    (tp->t_session != NULL && tp->t_session->s_ttyvp != NULL &&
1549 		    tp->t_session->s_ttyvp->v_type != VBAD)) {
1550 			/*
1551 			 * There is already a relation between a TTY and
1552 			 * a session, or the caller is not the session
1553 			 * leader.
1554 			 *
1555 			 * Allow the TTY to be stolen when the vnode is
1556 			 * invalid, but the reference to the TTY is
1557 			 * still active.  This allows immediate reuse of
1558 			 * TTYs of which the session leader has been
1559 			 * killed or the TTY revoked.
1560 			 */
1561 			sx_xunlock(&proctree_lock);
1562 			return (EPERM);
1563 		}
1564 
1565 		/* Connect the session to the TTY. */
1566 		tp->t_session = p->p_session;
1567 		tp->t_session->s_ttyp = tp;
1568 		tp->t_sessioncnt++;
1569 		sx_xunlock(&proctree_lock);
1570 
1571 		/* Assign foreground process group. */
1572 		tp->t_pgrp = p->p_pgrp;
1573 		PROC_LOCK(p);
1574 		p->p_flag |= P_CONTROLT;
1575 		PROC_UNLOCK(p);
1576 
1577 		return (0);
1578 	}
1579 	case TIOCSPGRP: {
1580 		struct pgrp *pg;
1581 
1582 		/*
1583 		 * XXX: Temporarily unlock the TTY to locate the process
1584 		 * group. This code would be lot nicer if we would ever
1585 		 * decompose proctree_lock.
1586 		 */
1587 		tty_unlock(tp);
1588 		sx_slock(&proctree_lock);
1589 		pg = pgfind(*(int *)data);
1590 		if (pg != NULL)
1591 			PGRP_UNLOCK(pg);
1592 		if (pg == NULL || pg->pg_session != td->td_proc->p_session) {
1593 			sx_sunlock(&proctree_lock);
1594 			tty_lock(tp);
1595 			return (EPERM);
1596 		}
1597 		tty_lock(tp);
1598 
1599 		/*
1600 		 * Determine if this TTY is the controlling TTY after
1601 		 * relocking the TTY.
1602 		 */
1603 		if (!tty_is_ctty(tp, td->td_proc)) {
1604 			sx_sunlock(&proctree_lock);
1605 			return (ENOTTY);
1606 		}
1607 		tp->t_pgrp = pg;
1608 		sx_sunlock(&proctree_lock);
1609 
1610 		/* Wake up the background process groups. */
1611 		cv_broadcast(&tp->t_bgwait);
1612 		return (0);
1613 	}
1614 	case TIOCFLUSH: {
1615 		int flags = *(int *)data;
1616 
1617 		if (flags == 0)
1618 			flags = (FREAD|FWRITE);
1619 		else
1620 			flags &= (FREAD|FWRITE);
1621 		tty_flush(tp, flags);
1622 		return (0);
1623 	}
1624 	case TIOCDRAIN:
1625 		/* Drain TTY output. */
1626 		return tty_drain(tp);
1627 	case TIOCCONS:
1628 		/* Set terminal as console TTY. */
1629 		if (*(int *)data) {
1630 			error = priv_check(td, PRIV_TTY_CONSOLE);
1631 			if (error)
1632 				return (error);
1633 
1634 			/*
1635 			 * XXX: constty should really need to be locked!
1636 			 * XXX: allow disconnected constty's to be stolen!
1637 			 */
1638 
1639 			if (constty == tp)
1640 				return (0);
1641 			if (constty != NULL)
1642 				return (EBUSY);
1643 
1644 			tty_unlock(tp);
1645 			constty_set(tp);
1646 			tty_lock(tp);
1647 		} else if (constty == tp) {
1648 			constty_clear();
1649 		}
1650 		return (0);
1651 	case TIOCGWINSZ:
1652 		/* Obtain window size. */
1653 		*(struct winsize*)data = tp->t_winsize;
1654 		return (0);
1655 	case TIOCSWINSZ:
1656 		/* Set window size. */
1657 		if (bcmp(&tp->t_winsize, data, sizeof(struct winsize)) == 0)
1658 			return (0);
1659 		tp->t_winsize = *(struct winsize*)data;
1660 		tty_signal_pgrp(tp, SIGWINCH);
1661 		return (0);
1662 	case TIOCEXCL:
1663 		tp->t_flags |= TF_EXCLUDE;
1664 		return (0);
1665 	case TIOCNXCL:
1666 		tp->t_flags &= ~TF_EXCLUDE;
1667 		return (0);
1668 	case TIOCSTOP:
1669 		tp->t_flags |= TF_STOPPED;
1670 		ttydevsw_pktnotify(tp, TIOCPKT_STOP);
1671 		return (0);
1672 	case TIOCSTART:
1673 		tp->t_flags &= ~TF_STOPPED;
1674 		ttydevsw_outwakeup(tp);
1675 		ttydevsw_pktnotify(tp, TIOCPKT_START);
1676 		return (0);
1677 	case TIOCSTAT:
1678 		tty_info(tp);
1679 		return (0);
1680 	}
1681 
1682 #ifdef COMPAT_43TTY
1683 	return tty_ioctl_compat(tp, cmd, data, td);
1684 #else /* !COMPAT_43TTY */
1685 	return (ENOIOCTL);
1686 #endif /* COMPAT_43TTY */
1687 }
1688 
1689 int
1690 tty_ioctl(struct tty *tp, u_long cmd, void *data, struct thread *td)
1691 {
1692 	int error;
1693 
1694 	tty_lock_assert(tp, MA_OWNED);
1695 
1696 	if (tty_gone(tp))
1697 		return (ENXIO);
1698 
1699 	error = ttydevsw_ioctl(tp, cmd, data, td);
1700 	if (error == ENOIOCTL)
1701 		error = tty_generic_ioctl(tp, cmd, data, td);
1702 
1703 	return (error);
1704 }
1705 
1706 dev_t
1707 tty_udev(struct tty *tp)
1708 {
1709 	if (tp->t_dev)
1710 		return dev2udev(tp->t_dev);
1711 	else
1712 		return NODEV;
1713 }
1714 
1715 int
1716 tty_checkoutq(struct tty *tp)
1717 {
1718 
1719 	/* 256 bytes should be enough to print a log message. */
1720 	return (ttyoutq_bytesleft(&tp->t_outq) >= 256);
1721 }
1722 
1723 void
1724 tty_hiwat_in_block(struct tty *tp)
1725 {
1726 
1727 	if ((tp->t_flags & TF_HIWAT_IN) == 0 &&
1728 	    tp->t_termios.c_iflag & IXOFF &&
1729 	    tp->t_termios.c_cc[VSTOP] != _POSIX_VDISABLE) {
1730 		/*
1731 		 * Input flow control. Only enter the high watermark when we
1732 		 * can successfully store the VSTOP character.
1733 		 */
1734 		if (ttyoutq_write_nofrag(&tp->t_outq,
1735 		    &tp->t_termios.c_cc[VSTOP], 1) == 0)
1736 			tp->t_flags |= TF_HIWAT_IN;
1737 	} else {
1738 		/* No input flow control. */
1739 		tp->t_flags |= TF_HIWAT_IN;
1740 	}
1741 }
1742 
1743 void
1744 tty_hiwat_in_unblock(struct tty *tp)
1745 {
1746 
1747 	if (tp->t_flags & TF_HIWAT_IN &&
1748 	    tp->t_termios.c_iflag & IXOFF &&
1749 	    tp->t_termios.c_cc[VSTART] != _POSIX_VDISABLE) {
1750 		/*
1751 		 * Input flow control. Only leave the high watermark when we
1752 		 * can successfully store the VSTART character.
1753 		 */
1754 		if (ttyoutq_write_nofrag(&tp->t_outq,
1755 		    &tp->t_termios.c_cc[VSTART], 1) == 0)
1756 			tp->t_flags &= ~TF_HIWAT_IN;
1757 	} else {
1758 		/* No input flow control. */
1759 		tp->t_flags &= ~TF_HIWAT_IN;
1760 	}
1761 
1762 	if (!tty_gone(tp))
1763 		ttydevsw_inwakeup(tp);
1764 }
1765 
1766 /*
1767  * TTY hooks interface.
1768  */
1769 
1770 static int
1771 ttyhook_defrint(struct tty *tp, char c, int flags)
1772 {
1773 
1774 	if (ttyhook_rint_bypass(tp, &c, 1) != 1)
1775 		return (-1);
1776 
1777 	return (0);
1778 }
1779 
1780 int
1781 ttyhook_register(struct tty **rtp, struct proc *p, int fd,
1782     struct ttyhook *th, void *softc)
1783 {
1784 	struct tty *tp;
1785 	struct file *fp;
1786 	struct cdev *dev;
1787 	struct cdevsw *cdp;
1788 	struct filedesc *fdp;
1789 	int error;
1790 
1791 	/* Validate the file descriptor. */
1792 	if ((fdp = p->p_fd) == NULL)
1793 		return (EBADF);
1794 
1795 	fp = fget_unlocked(fdp, fd);
1796 	if (fp == NULL)
1797 		return (EBADF);
1798 	if (fp->f_ops == &badfileops) {
1799 		error = EBADF;
1800 		goto done1;
1801 	}
1802 
1803 	/*
1804 	 * Make sure the vnode is bound to a character device.
1805 	 * Unlocked check for the vnode type is ok there, because we
1806 	 * only shall prevent calling devvn_refthread on the file that
1807 	 * never has been opened over a character device.
1808 	 */
1809 	if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR) {
1810 		error = EINVAL;
1811 		goto done1;
1812 	}
1813 
1814 	/* Make sure it is a TTY. */
1815 	cdp = devvn_refthread(fp->f_vnode, &dev);
1816 	if (cdp == NULL) {
1817 		error = ENXIO;
1818 		goto done1;
1819 	}
1820 	if (dev != fp->f_data) {
1821 		error = ENXIO;
1822 		goto done2;
1823 	}
1824 	if (cdp != &ttydev_cdevsw) {
1825 		error = ENOTTY;
1826 		goto done2;
1827 	}
1828 	tp = dev->si_drv1;
1829 
1830 	/* Try to attach the hook to the TTY. */
1831 	error = EBUSY;
1832 	tty_lock(tp);
1833 	MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
1834 	if (tp->t_flags & TF_HOOK)
1835 		goto done3;
1836 
1837 	tp->t_flags |= TF_HOOK;
1838 	tp->t_hook = th;
1839 	tp->t_hooksoftc = softc;
1840 	*rtp = tp;
1841 	error = 0;
1842 
1843 	/* Maybe we can switch into bypass mode now. */
1844 	ttydisc_optimize(tp);
1845 
1846 	/* Silently convert rint() calls to rint_bypass() when possible. */
1847 	if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
1848 		th->th_rint = ttyhook_defrint;
1849 
1850 done3:	tty_unlock(tp);
1851 done2:	dev_relthread(dev);
1852 done1:	fdrop(fp, curthread);
1853 	return (error);
1854 }
1855 
1856 void
1857 ttyhook_unregister(struct tty *tp)
1858 {
1859 
1860 	tty_lock_assert(tp, MA_OWNED);
1861 	MPASS(tp->t_flags & TF_HOOK);
1862 
1863 	/* Disconnect the hook. */
1864 	tp->t_flags &= ~TF_HOOK;
1865 	tp->t_hook = NULL;
1866 
1867 	/* Maybe we need to leave bypass mode. */
1868 	ttydisc_optimize(tp);
1869 
1870 	/* Maybe deallocate the TTY as well. */
1871 	tty_rel_free(tp);
1872 }
1873 
1874 /*
1875  * /dev/console handling.
1876  */
1877 
1878 static int
1879 ttyconsdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
1880 {
1881 	struct tty *tp;
1882 
1883 	/* System has no console device. */
1884 	if (dev_console_filename == NULL)
1885 		return (ENXIO);
1886 
1887 	/* Look up corresponding TTY by device name. */
1888 	sx_slock(&tty_list_sx);
1889 	TAILQ_FOREACH(tp, &tty_list, t_list) {
1890 		if (strcmp(dev_console_filename, tty_devname(tp)) == 0) {
1891 			dev_console->si_drv1 = tp;
1892 			break;
1893 		}
1894 	}
1895 	sx_sunlock(&tty_list_sx);
1896 
1897 	/* System console has no TTY associated. */
1898 	if (dev_console->si_drv1 == NULL)
1899 		return (ENXIO);
1900 
1901 	return (ttydev_open(dev, oflags, devtype, td));
1902 }
1903 
1904 static int
1905 ttyconsdev_write(struct cdev *dev, struct uio *uio, int ioflag)
1906 {
1907 
1908 	log_console(uio);
1909 
1910 	return (ttydev_write(dev, uio, ioflag));
1911 }
1912 
1913 /*
1914  * /dev/console is a little different than normal TTY's.  When opened,
1915  * it determines which TTY to use.  When data gets written to it, it
1916  * will be logged in the kernel message buffer.
1917  */
1918 static struct cdevsw ttyconsdev_cdevsw = {
1919 	.d_version	= D_VERSION,
1920 	.d_open		= ttyconsdev_open,
1921 	.d_close	= ttydev_close,
1922 	.d_read		= ttydev_read,
1923 	.d_write	= ttyconsdev_write,
1924 	.d_ioctl	= ttydev_ioctl,
1925 	.d_kqfilter	= ttydev_kqfilter,
1926 	.d_poll		= ttydev_poll,
1927 	.d_mmap		= ttydev_mmap,
1928 	.d_name		= "ttyconsdev",
1929 	.d_flags	= D_TTY,
1930 };
1931 
1932 static void
1933 ttyconsdev_init(void *unused)
1934 {
1935 
1936 	dev_console = make_dev(&ttyconsdev_cdevsw, 0, UID_ROOT, GID_WHEEL,
1937 	    0600, "console");
1938 }
1939 
1940 SYSINIT(tty, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyconsdev_init, NULL);
1941 
1942 void
1943 ttyconsdev_select(const char *name)
1944 {
1945 
1946 	dev_console_filename = name;
1947 }
1948 
1949 /*
1950  * Debugging routines.
1951  */
1952 
1953 #include "opt_ddb.h"
1954 #ifdef DDB
1955 #include <ddb/ddb.h>
1956 #include <ddb/db_sym.h>
1957 
1958 static struct {
1959 	int flag;
1960 	char val;
1961 } ttystates[] = {
1962 #if 0
1963 	{ TF_NOPREFIX,		'N' },
1964 #endif
1965 	{ TF_INITLOCK,		'I' },
1966 	{ TF_CALLOUT,		'C' },
1967 
1968 	/* Keep these together -> 'Oi' and 'Oo'. */
1969 	{ TF_OPENED,		'O' },
1970 	{ TF_OPENED_IN,		'i' },
1971 	{ TF_OPENED_OUT,	'o' },
1972 	{ TF_OPENED_CONS,	'c' },
1973 
1974 	{ TF_GONE,		'G' },
1975 	{ TF_OPENCLOSE,		'B' },
1976 	{ TF_ASYNC,		'Y' },
1977 	{ TF_LITERAL,		'L' },
1978 
1979 	/* Keep these together -> 'Hi' and 'Ho'. */
1980 	{ TF_HIWAT,		'H' },
1981 	{ TF_HIWAT_IN,		'i' },
1982 	{ TF_HIWAT_OUT,		'o' },
1983 
1984 	{ TF_STOPPED,		'S' },
1985 	{ TF_EXCLUDE,		'X' },
1986 	{ TF_BYPASS,		'l' },
1987 	{ TF_ZOMBIE,		'Z' },
1988 	{ TF_HOOK,		's' },
1989 
1990 	/* Keep these together -> 'bi' and 'bo'. */
1991 	{ TF_BUSY,		'b' },
1992 	{ TF_BUSY_IN,		'i' },
1993 	{ TF_BUSY_OUT,		'o' },
1994 
1995 	{ 0,			'\0'},
1996 };
1997 
1998 #define	TTY_FLAG_BITS \
1999 	"\20\1NOPREFIX\2INITLOCK\3CALLOUT\4OPENED_IN\5OPENED_OUT\6GONE" \
2000 	"\7OPENCLOSE\10ASYNC\11LITERAL\12HIWAT_IN\13HIWAT_OUT\14STOPPED" \
2001 	"\15EXCLUDE\16BYPASS\17ZOMBIE\20HOOK"
2002 
2003 #define DB_PRINTSYM(name, addr) \
2004 	db_printf("%s  " #name ": ", sep); \
2005 	db_printsym((db_addr_t) addr, DB_STGY_ANY); \
2006 	db_printf("\n");
2007 
2008 static void
2009 _db_show_devsw(const char *sep, const struct ttydevsw *tsw)
2010 {
2011 	db_printf("%sdevsw: ", sep);
2012 	db_printsym((db_addr_t)tsw, DB_STGY_ANY);
2013 	db_printf(" (%p)\n", tsw);
2014 	DB_PRINTSYM(open, tsw->tsw_open);
2015 	DB_PRINTSYM(close, tsw->tsw_close);
2016 	DB_PRINTSYM(outwakeup, tsw->tsw_outwakeup);
2017 	DB_PRINTSYM(inwakeup, tsw->tsw_inwakeup);
2018 	DB_PRINTSYM(ioctl, tsw->tsw_ioctl);
2019 	DB_PRINTSYM(param, tsw->tsw_param);
2020 	DB_PRINTSYM(modem, tsw->tsw_modem);
2021 	DB_PRINTSYM(mmap, tsw->tsw_mmap);
2022 	DB_PRINTSYM(pktnotify, tsw->tsw_pktnotify);
2023 	DB_PRINTSYM(free, tsw->tsw_free);
2024 }
2025 static void
2026 _db_show_hooks(const char *sep, const struct ttyhook *th)
2027 {
2028 	db_printf("%shook: ", sep);
2029 	db_printsym((db_addr_t)th, DB_STGY_ANY);
2030 	db_printf(" (%p)\n", th);
2031 	if (th == NULL)
2032 		return;
2033 	DB_PRINTSYM(rint, th->th_rint);
2034 	DB_PRINTSYM(rint_bypass, th->th_rint_bypass);
2035 	DB_PRINTSYM(rint_done, th->th_rint_done);
2036 	DB_PRINTSYM(rint_poll, th->th_rint_poll);
2037 	DB_PRINTSYM(getc_inject, th->th_getc_inject);
2038 	DB_PRINTSYM(getc_capture, th->th_getc_capture);
2039 	DB_PRINTSYM(getc_poll, th->th_getc_poll);
2040 	DB_PRINTSYM(close, th->th_close);
2041 }
2042 
2043 static void
2044 _db_show_termios(const char *name, const struct termios *t)
2045 {
2046 
2047 	db_printf("%s: iflag 0x%x oflag 0x%x cflag 0x%x "
2048 	    "lflag 0x%x ispeed %u ospeed %u\n", name,
2049 	    t->c_iflag, t->c_oflag, t->c_cflag, t->c_lflag,
2050 	    t->c_ispeed, t->c_ospeed);
2051 }
2052 
2053 /* DDB command to show TTY statistics. */
2054 DB_SHOW_COMMAND(tty, db_show_tty)
2055 {
2056 	struct tty *tp;
2057 
2058 	if (!have_addr) {
2059 		db_printf("usage: show tty <addr>\n");
2060 		return;
2061 	}
2062 	tp = (struct tty *)addr;
2063 
2064 	db_printf("0x%p: %s\n", tp, tty_devname(tp));
2065 	db_printf("\tmtx: %p\n", tp->t_mtx);
2066 	db_printf("\tflags: %b\n", tp->t_flags, TTY_FLAG_BITS);
2067 	db_printf("\trevokecnt: %u\n", tp->t_revokecnt);
2068 
2069 	/* Buffering mechanisms. */
2070 	db_printf("\tinq: %p begin %u linestart %u reprint %u end %u "
2071 	    "nblocks %u quota %u\n", &tp->t_inq, tp->t_inq.ti_begin,
2072 	    tp->t_inq.ti_linestart, tp->t_inq.ti_reprint, tp->t_inq.ti_end,
2073 	    tp->t_inq.ti_nblocks, tp->t_inq.ti_quota);
2074 	db_printf("\toutq: %p begin %u end %u nblocks %u quota %u\n",
2075 	    &tp->t_outq, tp->t_outq.to_begin, tp->t_outq.to_end,
2076 	    tp->t_outq.to_nblocks, tp->t_outq.to_quota);
2077 	db_printf("\tinlow: %zu\n", tp->t_inlow);
2078 	db_printf("\toutlow: %zu\n", tp->t_outlow);
2079 	_db_show_termios("\ttermios", &tp->t_termios);
2080 	db_printf("\twinsize: row %u col %u xpixel %u ypixel %u\n",
2081 	    tp->t_winsize.ws_row, tp->t_winsize.ws_col,
2082 	    tp->t_winsize.ws_xpixel, tp->t_winsize.ws_ypixel);
2083 	db_printf("\tcolumn: %u\n", tp->t_column);
2084 	db_printf("\twritepos: %u\n", tp->t_writepos);
2085 	db_printf("\tcompatflags: 0x%x\n", tp->t_compatflags);
2086 
2087 	/* Init/lock-state devices. */
2088 	_db_show_termios("\ttermios_init_in", &tp->t_termios_init_in);
2089 	_db_show_termios("\ttermios_init_out", &tp->t_termios_init_out);
2090 	_db_show_termios("\ttermios_lock_in", &tp->t_termios_lock_in);
2091 	_db_show_termios("\ttermios_lock_out", &tp->t_termios_lock_out);
2092 
2093 	/* Hooks */
2094 	_db_show_devsw("\t", tp->t_devsw);
2095 	_db_show_hooks("\t", tp->t_hook);
2096 
2097 	/* Process info. */
2098 	db_printf("\tpgrp: %p gid %d jobc %d\n", tp->t_pgrp,
2099 	    tp->t_pgrp ? tp->t_pgrp->pg_id : 0,
2100 	    tp->t_pgrp ? tp->t_pgrp->pg_jobc : 0);
2101 	db_printf("\tsession: %p", tp->t_session);
2102 	if (tp->t_session != NULL)
2103 	    db_printf(" count %u leader %p tty %p sid %d login %s",
2104 		tp->t_session->s_count, tp->t_session->s_leader,
2105 		tp->t_session->s_ttyp, tp->t_session->s_sid,
2106 		tp->t_session->s_login);
2107 	db_printf("\n");
2108 	db_printf("\tsessioncnt: %u\n", tp->t_sessioncnt);
2109 	db_printf("\tdevswsoftc: %p\n", tp->t_devswsoftc);
2110 	db_printf("\thooksoftc: %p\n", tp->t_hooksoftc);
2111 	db_printf("\tdev: %p\n", tp->t_dev);
2112 }
2113 
2114 /* DDB command to list TTYs. */
2115 DB_SHOW_ALL_COMMAND(ttys, db_show_all_ttys)
2116 {
2117 	struct tty *tp;
2118 	size_t isiz, osiz;
2119 	int i, j;
2120 
2121 	/* Make the output look like `pstat -t'. */
2122 	db_printf("PTR        ");
2123 #if defined(__LP64__)
2124 	db_printf("        ");
2125 #endif
2126 	db_printf("      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   "
2127 	    "COL  SESS  PGID STATE\n");
2128 
2129 	TAILQ_FOREACH(tp, &tty_list, t_list) {
2130 		isiz = tp->t_inq.ti_nblocks * TTYINQ_DATASIZE;
2131 		osiz = tp->t_outq.to_nblocks * TTYOUTQ_DATASIZE;
2132 
2133 		db_printf("%p %10s %5zu %4u %4u %4zu %5zu %4u %4zu %5u %5d %5d ",
2134 		    tp,
2135 		    tty_devname(tp),
2136 		    isiz,
2137 		    tp->t_inq.ti_linestart - tp->t_inq.ti_begin,
2138 		    tp->t_inq.ti_end - tp->t_inq.ti_linestart,
2139 		    isiz - tp->t_inlow,
2140 		    osiz,
2141 		    tp->t_outq.to_end - tp->t_outq.to_begin,
2142 		    osiz - tp->t_outlow,
2143 		    MIN(tp->t_column, 99999),
2144 		    tp->t_session ? tp->t_session->s_sid : 0,
2145 		    tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
2146 
2147 		/* Flag bits. */
2148 		for (i = j = 0; ttystates[i].flag; i++)
2149 			if (tp->t_flags & ttystates[i].flag) {
2150 				db_printf("%c", ttystates[i].val);
2151 				j++;
2152 			}
2153 		if (j == 0)
2154 			db_printf("-");
2155 		db_printf("\n");
2156 	}
2157 }
2158 #endif /* DDB */
2159