xref: /freebsd/sys/kern/tty.c (revision 884a2a699669ec61e2366e3e358342dbc94be24a)
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 		ttydevsw_param(tp, &tp->t_termios);
271 		/* Prevent modem control on callout devices and /dev/console. */
272 		if (TTY_CALLOUT(tp, dev) || dev == dev_console)
273 			tp->t_termios.c_cflag |= CLOCAL;
274 
275 		ttydevsw_modem(tp, SER_DTR|SER_RTS, 0);
276 
277 		error = ttydevsw_open(tp);
278 		if (error != 0)
279 			goto done;
280 
281 		ttydisc_open(tp);
282 		tty_watermarks(tp);
283 	}
284 
285 	/* Wait for Carrier Detect. */
286 	if ((oflags & O_NONBLOCK) == 0 &&
287 	    (tp->t_termios.c_cflag & CLOCAL) == 0) {
288 		while ((ttydevsw_modem(tp, 0, 0) & SER_DCD) == 0) {
289 			error = tty_wait(tp, &tp->t_dcdwait);
290 			if (error != 0)
291 				goto done;
292 		}
293 	}
294 
295 	if (dev == dev_console)
296 		tp->t_flags |= TF_OPENED_CONS;
297 	else if (TTY_CALLOUT(tp, dev))
298 		tp->t_flags |= TF_OPENED_OUT;
299 	else
300 		tp->t_flags |= TF_OPENED_IN;
301 
302 done:	tp->t_flags &= ~TF_OPENCLOSE;
303 	cv_broadcast(&tp->t_dcdwait);
304 	ttydev_leave(tp);
305 
306 	return (error);
307 }
308 
309 static int
310 ttydev_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
311 {
312 	struct tty *tp = dev->si_drv1;
313 
314 	tty_lock(tp);
315 
316 	/*
317 	 * Don't actually close the device if it is being used as the
318 	 * console.
319 	 */
320 	MPASS((tp->t_flags & TF_OPENED) != TF_OPENED);
321 	if (dev == dev_console)
322 		tp->t_flags &= ~TF_OPENED_CONS;
323 	else
324 		tp->t_flags &= ~(TF_OPENED_IN|TF_OPENED_OUT);
325 
326 	if (tp->t_flags & TF_OPENED) {
327 		tty_unlock(tp);
328 		return (0);
329 	}
330 
331 	/*
332 	 * This can only be called once. The callin and the callout
333 	 * devices cannot be opened at the same time.
334 	 */
335 	tp->t_flags &= ~(TF_EXCLUDE|TF_STOPPED);
336 
337 	/* Properly wake up threads that are stuck - revoke(). */
338 	tp->t_revokecnt++;
339 	tty_wakeup(tp, FREAD|FWRITE);
340 	cv_broadcast(&tp->t_bgwait);
341 	cv_broadcast(&tp->t_dcdwait);
342 
343 	ttydev_leave(tp);
344 
345 	return (0);
346 }
347 
348 static __inline int
349 tty_is_ctty(struct tty *tp, struct proc *p)
350 {
351 	tty_lock_assert(tp, MA_OWNED);
352 
353 	return (p->p_session == tp->t_session && p->p_flag & P_CONTROLT);
354 }
355 
356 static int
357 tty_wait_background(struct tty *tp, struct thread *td, int sig)
358 {
359 	struct proc *p = td->td_proc;
360 	struct pgrp *pg;
361 	ksiginfo_t ksi;
362 	int error;
363 
364 	MPASS(sig == SIGTTIN || sig == SIGTTOU);
365 	tty_lock_assert(tp, MA_OWNED);
366 
367 	for (;;) {
368 		PROC_LOCK(p);
369 		/*
370 		 * The process should only sleep, when:
371 		 * - This terminal is the controling terminal
372 		 * - Its process group is not the foreground process
373 		 *   group
374 		 * - The parent process isn't waiting for the child to
375 		 *   exit
376 		 * - the signal to send to the process isn't masked
377 		 */
378 		if (!tty_is_ctty(tp, p) || p->p_pgrp == tp->t_pgrp) {
379 			/* Allow the action to happen. */
380 			PROC_UNLOCK(p);
381 			return (0);
382 		}
383 
384 		if (SIGISMEMBER(p->p_sigacts->ps_sigignore, sig) ||
385 		    SIGISMEMBER(td->td_sigmask, sig)) {
386 			/* Only allow them in write()/ioctl(). */
387 			PROC_UNLOCK(p);
388 			return (sig == SIGTTOU ? 0 : EIO);
389 		}
390 
391 		pg = p->p_pgrp;
392 		if (p->p_flag & P_PPWAIT || pg->pg_jobc == 0) {
393 			/* Don't allow the action to happen. */
394 			PROC_UNLOCK(p);
395 			return (EIO);
396 		}
397 		PROC_UNLOCK(p);
398 
399 		/*
400 		 * Send the signal and sleep until we're the new
401 		 * foreground process group.
402 		 */
403 		if (sig != 0) {
404 			ksiginfo_init(&ksi);
405 			ksi.ksi_code = SI_KERNEL;
406 			ksi.ksi_signo = sig;
407 			sig = 0;
408 		}
409 		PGRP_LOCK(pg);
410 		pgsignal(pg, ksi.ksi_signo, 1, &ksi);
411 		PGRP_UNLOCK(pg);
412 
413 		error = tty_wait(tp, &tp->t_bgwait);
414 		if (error)
415 			return (error);
416 	}
417 }
418 
419 static int
420 ttydev_read(struct cdev *dev, struct uio *uio, int ioflag)
421 {
422 	struct tty *tp = dev->si_drv1;
423 	int error;
424 
425 	error = ttydev_enter(tp);
426 	if (error)
427 		goto done;
428 
429 	error = tty_wait_background(tp, curthread, SIGTTIN);
430 	if (error) {
431 		tty_unlock(tp);
432 		goto done;
433 	}
434 
435 	error = ttydisc_read(tp, uio, ioflag);
436 	tty_unlock(tp);
437 
438 	/*
439 	 * The read() call should not throw an error when the device is
440 	 * being destroyed. Silently convert it to an EOF.
441 	 */
442 done:	if (error == ENXIO)
443 		error = 0;
444 	return (error);
445 }
446 
447 static int
448 ttydev_write(struct cdev *dev, struct uio *uio, int ioflag)
449 {
450 	struct tty *tp = dev->si_drv1;
451 	int error;
452 
453 	error = ttydev_enter(tp);
454 	if (error)
455 		return (error);
456 
457 	if (tp->t_termios.c_lflag & TOSTOP) {
458 		error = tty_wait_background(tp, curthread, SIGTTOU);
459 		if (error)
460 			goto done;
461 	}
462 
463 	if (ioflag & IO_NDELAY && tp->t_flags & TF_BUSY_OUT) {
464 		/* Allow non-blocking writes to bypass serialization. */
465 		error = ttydisc_write(tp, uio, ioflag);
466 	} else {
467 		/* Serialize write() calls. */
468 		while (tp->t_flags & TF_BUSY_OUT) {
469 			error = tty_wait(tp, &tp->t_outserwait);
470 			if (error)
471 				goto done;
472 		}
473 
474  		tp->t_flags |= TF_BUSY_OUT;
475 		error = ttydisc_write(tp, uio, ioflag);
476  		tp->t_flags &= ~TF_BUSY_OUT;
477 		cv_signal(&tp->t_outserwait);
478 	}
479 
480 done:	tty_unlock(tp);
481 	return (error);
482 }
483 
484 static int
485 ttydev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
486     struct thread *td)
487 {
488 	struct tty *tp = dev->si_drv1;
489 	int error;
490 
491 	error = ttydev_enter(tp);
492 	if (error)
493 		return (error);
494 
495 	switch (cmd) {
496 	case TIOCCBRK:
497 	case TIOCCONS:
498 	case TIOCDRAIN:
499 	case TIOCEXCL:
500 	case TIOCFLUSH:
501 	case TIOCNXCL:
502 	case TIOCSBRK:
503 	case TIOCSCTTY:
504 	case TIOCSETA:
505 	case TIOCSETAF:
506 	case TIOCSETAW:
507 	case TIOCSPGRP:
508 	case TIOCSTART:
509 	case TIOCSTAT:
510 	case TIOCSTI:
511 	case TIOCSTOP:
512 	case TIOCSWINSZ:
513 #if 0
514 	case TIOCSDRAINWAIT:
515 	case TIOCSETD:
516 #endif
517 #ifdef COMPAT_43TTY
518 	case  TIOCLBIC:
519 	case  TIOCLBIS:
520 	case  TIOCLSET:
521 	case  TIOCSETC:
522 	case OTIOCSETD:
523 	case  TIOCSETN:
524 	case  TIOCSETP:
525 	case  TIOCSLTC:
526 #endif /* COMPAT_43TTY */
527 		/*
528 		 * If the ioctl() causes the TTY to be modified, let it
529 		 * wait in the background.
530 		 */
531 		error = tty_wait_background(tp, curthread, SIGTTOU);
532 		if (error)
533 			goto done;
534 	}
535 
536 	if (cmd == TIOCSETA || cmd == TIOCSETAW || cmd == TIOCSETAF) {
537 		struct termios *old = &tp->t_termios;
538 		struct termios *new = (struct termios *)data;
539 		struct termios *lock = TTY_CALLOUT(tp, dev) ?
540 		    &tp->t_termios_lock_out : &tp->t_termios_lock_in;
541 		int cc;
542 
543 		/*
544 		 * Lock state devices.  Just overwrite the values of the
545 		 * commands that are currently in use.
546 		 */
547 		new->c_iflag = (old->c_iflag & lock->c_iflag) |
548 		    (new->c_iflag & ~lock->c_iflag);
549 		new->c_oflag = (old->c_oflag & lock->c_oflag) |
550 		    (new->c_oflag & ~lock->c_oflag);
551 		new->c_cflag = (old->c_cflag & lock->c_cflag) |
552 		    (new->c_cflag & ~lock->c_cflag);
553 		new->c_lflag = (old->c_lflag & lock->c_lflag) |
554 		    (new->c_lflag & ~lock->c_lflag);
555 		for (cc = 0; cc < NCCS; ++cc)
556 			if (lock->c_cc[cc])
557 				new->c_cc[cc] = old->c_cc[cc];
558 		if (lock->c_ispeed)
559 			new->c_ispeed = old->c_ispeed;
560 		if (lock->c_ospeed)
561 			new->c_ospeed = old->c_ospeed;
562 	}
563 
564 	error = tty_ioctl(tp, cmd, data, fflag, td);
565 done:	tty_unlock(tp);
566 
567 	return (error);
568 }
569 
570 static int
571 ttydev_poll(struct cdev *dev, int events, struct thread *td)
572 {
573 	struct tty *tp = dev->si_drv1;
574 	int error, revents = 0;
575 
576 	error = ttydev_enter(tp);
577 	if (error)
578 		return ((events & (POLLIN|POLLRDNORM)) | POLLHUP);
579 
580 	if (events & (POLLIN|POLLRDNORM)) {
581 		/* See if we can read something. */
582 		if (ttydisc_read_poll(tp) > 0)
583 			revents |= events & (POLLIN|POLLRDNORM);
584 	}
585 
586 	if (tp->t_flags & TF_ZOMBIE) {
587 		/* Hangup flag on zombie state. */
588 		revents |= POLLHUP;
589 	} else if (events & (POLLOUT|POLLWRNORM)) {
590 		/* See if we can write something. */
591 		if (ttydisc_write_poll(tp) > 0)
592 			revents |= events & (POLLOUT|POLLWRNORM);
593 	}
594 
595 	if (revents == 0) {
596 		if (events & (POLLIN|POLLRDNORM))
597 			selrecord(td, &tp->t_inpoll);
598 		if (events & (POLLOUT|POLLWRNORM))
599 			selrecord(td, &tp->t_outpoll);
600 	}
601 
602 	tty_unlock(tp);
603 
604 	return (revents);
605 }
606 
607 static int
608 ttydev_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
609     int nprot, vm_memattr_t *memattr)
610 {
611 	struct tty *tp = dev->si_drv1;
612 	int error;
613 
614 	/* Handle mmap() through the driver. */
615 
616 	error = ttydev_enter(tp);
617 	if (error)
618 		return (-1);
619 	error = ttydevsw_mmap(tp, offset, paddr, nprot, memattr);
620 	tty_unlock(tp);
621 
622 	return (error);
623 }
624 
625 /*
626  * kqueue support.
627  */
628 
629 static void
630 tty_kqops_read_detach(struct knote *kn)
631 {
632 	struct tty *tp = kn->kn_hook;
633 
634 	knlist_remove(&tp->t_inpoll.si_note, kn, 0);
635 }
636 
637 static int
638 tty_kqops_read_event(struct knote *kn, long hint)
639 {
640 	struct tty *tp = kn->kn_hook;
641 
642 	tty_lock_assert(tp, MA_OWNED);
643 
644 	if (tty_gone(tp) || tp->t_flags & TF_ZOMBIE) {
645 		kn->kn_flags |= EV_EOF;
646 		return (1);
647 	} else {
648 		kn->kn_data = ttydisc_read_poll(tp);
649 		return (kn->kn_data > 0);
650 	}
651 }
652 
653 static void
654 tty_kqops_write_detach(struct knote *kn)
655 {
656 	struct tty *tp = kn->kn_hook;
657 
658 	knlist_remove(&tp->t_outpoll.si_note, kn, 0);
659 }
660 
661 static int
662 tty_kqops_write_event(struct knote *kn, long hint)
663 {
664 	struct tty *tp = kn->kn_hook;
665 
666 	tty_lock_assert(tp, MA_OWNED);
667 
668 	if (tty_gone(tp)) {
669 		kn->kn_flags |= EV_EOF;
670 		return (1);
671 	} else {
672 		kn->kn_data = ttydisc_write_poll(tp);
673 		return (kn->kn_data > 0);
674 	}
675 }
676 
677 static struct filterops tty_kqops_read = {
678 	.f_isfd = 1,
679 	.f_detach = tty_kqops_read_detach,
680 	.f_event = tty_kqops_read_event,
681 };
682 static struct filterops tty_kqops_write = {
683 	.f_isfd = 1,
684 	.f_detach = tty_kqops_write_detach,
685 	.f_event = tty_kqops_write_event,
686 };
687 
688 static int
689 ttydev_kqfilter(struct cdev *dev, struct knote *kn)
690 {
691 	struct tty *tp = dev->si_drv1;
692 	int error;
693 
694 	error = ttydev_enter(tp);
695 	if (error)
696 		return (error);
697 
698 	switch (kn->kn_filter) {
699 	case EVFILT_READ:
700 		kn->kn_hook = tp;
701 		kn->kn_fop = &tty_kqops_read;
702 		knlist_add(&tp->t_inpoll.si_note, kn, 1);
703 		break;
704 	case EVFILT_WRITE:
705 		kn->kn_hook = tp;
706 		kn->kn_fop = &tty_kqops_write;
707 		knlist_add(&tp->t_outpoll.si_note, kn, 1);
708 		break;
709 	default:
710 		error = EINVAL;
711 		break;
712 	}
713 
714 	tty_unlock(tp);
715 	return (error);
716 }
717 
718 static struct cdevsw ttydev_cdevsw = {
719 	.d_version	= D_VERSION,
720 	.d_open		= ttydev_open,
721 	.d_close	= ttydev_close,
722 	.d_read		= ttydev_read,
723 	.d_write	= ttydev_write,
724 	.d_ioctl	= ttydev_ioctl,
725 	.d_kqfilter	= ttydev_kqfilter,
726 	.d_poll		= ttydev_poll,
727 	.d_mmap		= ttydev_mmap,
728 	.d_name		= "ttydev",
729 	.d_flags	= D_TTY,
730 };
731 
732 /*
733  * Init/lock-state devices
734  */
735 
736 static int
737 ttyil_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
738 {
739 	struct tty *tp = dev->si_drv1;
740 	int error = 0;
741 
742 	tty_lock(tp);
743 	if (tty_gone(tp))
744 		error = ENODEV;
745 	tty_unlock(tp);
746 
747 	return (error);
748 }
749 
750 static int
751 ttyil_close(struct cdev *dev, int flag, int mode, struct thread *td)
752 {
753 	return (0);
754 }
755 
756 static int
757 ttyil_rdwr(struct cdev *dev, struct uio *uio, int ioflag)
758 {
759 	return (ENODEV);
760 }
761 
762 static int
763 ttyil_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
764     struct thread *td)
765 {
766 	struct tty *tp = dev->si_drv1;
767 	int error = 0;
768 
769 	tty_lock(tp);
770 	if (tty_gone(tp)) {
771 		error = ENODEV;
772 		goto done;
773 	}
774 
775 	switch (cmd) {
776 	case TIOCGETA:
777 		/* Obtain terminal flags through tcgetattr(). */
778 		*(struct termios*)data = *(struct termios*)dev->si_drv2;
779 		break;
780 	case TIOCSETA:
781 		/* Set terminal flags through tcsetattr(). */
782 		error = priv_check(td, PRIV_TTY_SETA);
783 		if (error)
784 			break;
785 		*(struct termios*)dev->si_drv2 = *(struct termios*)data;
786 		break;
787 	case TIOCGETD:
788 		*(int *)data = TTYDISC;
789 		break;
790 	case TIOCGWINSZ:
791 		bzero(data, sizeof(struct winsize));
792 		break;
793 	default:
794 		error = ENOTTY;
795 	}
796 
797 done:	tty_unlock(tp);
798 	return (error);
799 }
800 
801 static struct cdevsw ttyil_cdevsw = {
802 	.d_version	= D_VERSION,
803 	.d_open		= ttyil_open,
804 	.d_close	= ttyil_close,
805 	.d_read		= ttyil_rdwr,
806 	.d_write	= ttyil_rdwr,
807 	.d_ioctl	= ttyil_ioctl,
808 	.d_name		= "ttyil",
809 	.d_flags	= D_TTY,
810 };
811 
812 static void
813 tty_init_termios(struct tty *tp)
814 {
815 	struct termios *t = &tp->t_termios_init_in;
816 
817 	t->c_cflag = TTYDEF_CFLAG;
818 	t->c_iflag = TTYDEF_IFLAG;
819 	t->c_lflag = TTYDEF_LFLAG;
820 	t->c_oflag = TTYDEF_OFLAG;
821 	t->c_ispeed = TTYDEF_SPEED;
822 	t->c_ospeed = TTYDEF_SPEED;
823 	memcpy(&t->c_cc, ttydefchars, sizeof ttydefchars);
824 
825 	tp->t_termios_init_out = *t;
826 }
827 
828 void
829 tty_init_console(struct tty *tp, speed_t s)
830 {
831 	struct termios *ti = &tp->t_termios_init_in;
832 	struct termios *to = &tp->t_termios_init_out;
833 
834 	if (s != 0) {
835 		ti->c_ispeed = ti->c_ospeed = s;
836 		to->c_ispeed = to->c_ospeed = s;
837 	}
838 
839 	ti->c_cflag |= CLOCAL;
840 	to->c_cflag |= CLOCAL;
841 }
842 
843 /*
844  * Standard device routine implementations, mostly meant for
845  * pseudo-terminal device drivers. When a driver creates a new terminal
846  * device class, missing routines are patched.
847  */
848 
849 static int
850 ttydevsw_defopen(struct tty *tp)
851 {
852 
853 	return (0);
854 }
855 
856 static void
857 ttydevsw_defclose(struct tty *tp)
858 {
859 }
860 
861 static void
862 ttydevsw_defoutwakeup(struct tty *tp)
863 {
864 
865 	panic("Terminal device has output, while not implemented");
866 }
867 
868 static void
869 ttydevsw_definwakeup(struct tty *tp)
870 {
871 }
872 
873 static int
874 ttydevsw_defioctl(struct tty *tp, u_long cmd, caddr_t data, struct thread *td)
875 {
876 
877 	return (ENOIOCTL);
878 }
879 
880 static int
881 ttydevsw_defparam(struct tty *tp, struct termios *t)
882 {
883 
884 	/*
885 	 * Allow the baud rate to be adjusted for pseudo-devices, but at
886 	 * least restrict it to 115200 to prevent excessive buffer
887 	 * usage.  Also disallow 0, to prevent foot shooting.
888 	 */
889 	if (t->c_ispeed < B50)
890 		t->c_ispeed = B50;
891 	else if (t->c_ispeed > B115200)
892 		t->c_ispeed = B115200;
893 	if (t->c_ospeed < B50)
894 		t->c_ospeed = B50;
895 	else if (t->c_ospeed > B115200)
896 		t->c_ospeed = B115200;
897 	t->c_cflag |= CREAD;
898 
899 	return (0);
900 }
901 
902 static int
903 ttydevsw_defmodem(struct tty *tp, int sigon, int sigoff)
904 {
905 
906 	/* Simulate a carrier to make the TTY layer happy. */
907 	return (SER_DCD);
908 }
909 
910 static int
911 ttydevsw_defmmap(struct tty *tp, vm_ooffset_t offset, vm_paddr_t *paddr,
912     int nprot, vm_memattr_t *memattr)
913 {
914 
915 	return (-1);
916 }
917 
918 static void
919 ttydevsw_defpktnotify(struct tty *tp, char event)
920 {
921 }
922 
923 static void
924 ttydevsw_deffree(void *softc)
925 {
926 
927 	panic("Terminal device freed without a free-handler");
928 }
929 
930 /*
931  * TTY allocation and deallocation. TTY devices can be deallocated when
932  * the driver doesn't use it anymore, when the TTY isn't a session's
933  * controlling TTY and when the device node isn't opened through devfs.
934  */
935 
936 struct tty *
937 tty_alloc(struct ttydevsw *tsw, void *sc)
938 {
939 
940 	return (tty_alloc_mutex(tsw, sc, NULL));
941 }
942 
943 struct tty *
944 tty_alloc_mutex(struct ttydevsw *tsw, void *sc, struct mtx *mutex)
945 {
946 	struct tty *tp;
947 
948 	/* Make sure the driver defines all routines. */
949 #define PATCH_FUNC(x) do {				\
950 	if (tsw->tsw_ ## x == NULL)			\
951 		tsw->tsw_ ## x = ttydevsw_def ## x;	\
952 } while (0)
953 	PATCH_FUNC(open);
954 	PATCH_FUNC(close);
955 	PATCH_FUNC(outwakeup);
956 	PATCH_FUNC(inwakeup);
957 	PATCH_FUNC(ioctl);
958 	PATCH_FUNC(param);
959 	PATCH_FUNC(modem);
960 	PATCH_FUNC(mmap);
961 	PATCH_FUNC(pktnotify);
962 	PATCH_FUNC(free);
963 #undef PATCH_FUNC
964 
965 	tp = malloc(sizeof(struct tty), M_TTY, M_WAITOK|M_ZERO);
966 	tp->t_devsw = tsw;
967 	tp->t_devswsoftc = sc;
968 	tp->t_flags = tsw->tsw_flags;
969 
970 	tty_init_termios(tp);
971 
972 	cv_init(&tp->t_inwait, "ttyin");
973 	cv_init(&tp->t_outwait, "ttyout");
974 	cv_init(&tp->t_outserwait, "ttyosr");
975 	cv_init(&tp->t_bgwait, "ttybg");
976 	cv_init(&tp->t_dcdwait, "ttydcd");
977 
978 	/* Allow drivers to use a custom mutex to lock the TTY. */
979 	if (mutex != NULL) {
980 		tp->t_mtx = mutex;
981 	} else {
982 		tp->t_mtx = &tp->t_mtxobj;
983 		mtx_init(&tp->t_mtxobj, "ttymtx", NULL, MTX_DEF);
984 	}
985 
986 	knlist_init_mtx(&tp->t_inpoll.si_note, tp->t_mtx);
987 	knlist_init_mtx(&tp->t_outpoll.si_note, tp->t_mtx);
988 
989 	sx_xlock(&tty_list_sx);
990 	TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
991 	tty_list_count++;
992 	sx_xunlock(&tty_list_sx);
993 
994 	return (tp);
995 }
996 
997 static void
998 tty_dealloc(void *arg)
999 {
1000 	struct tty *tp = arg;
1001 
1002 	sx_xlock(&tty_list_sx);
1003 	TAILQ_REMOVE(&tty_list, tp, t_list);
1004 	tty_list_count--;
1005 	sx_xunlock(&tty_list_sx);
1006 
1007 	/* Make sure we haven't leaked buffers. */
1008 	MPASS(ttyinq_getsize(&tp->t_inq) == 0);
1009 	MPASS(ttyoutq_getsize(&tp->t_outq) == 0);
1010 
1011 	knlist_destroy(&tp->t_inpoll.si_note);
1012 	knlist_destroy(&tp->t_outpoll.si_note);
1013 
1014 	cv_destroy(&tp->t_inwait);
1015 	cv_destroy(&tp->t_outwait);
1016 	cv_destroy(&tp->t_bgwait);
1017 	cv_destroy(&tp->t_dcdwait);
1018 	cv_destroy(&tp->t_outserwait);
1019 
1020 	if (tp->t_mtx == &tp->t_mtxobj)
1021 		mtx_destroy(&tp->t_mtxobj);
1022 	ttydevsw_free(tp);
1023 	free(tp, M_TTY);
1024 }
1025 
1026 static void
1027 tty_rel_free(struct tty *tp)
1028 {
1029 	struct cdev *dev;
1030 
1031 	tty_lock_assert(tp, MA_OWNED);
1032 
1033 #define	TF_ACTIVITY	(TF_GONE|TF_OPENED|TF_HOOK|TF_OPENCLOSE)
1034 	if (tp->t_sessioncnt != 0 || (tp->t_flags & TF_ACTIVITY) != TF_GONE) {
1035 		/* TTY is still in use. */
1036 		tty_unlock(tp);
1037 		return;
1038 	}
1039 
1040 	/* TTY can be deallocated. */
1041 	dev = tp->t_dev;
1042 	tp->t_dev = NULL;
1043 	tty_unlock(tp);
1044 
1045 	if (dev != NULL)
1046 		destroy_dev_sched_cb(dev, tty_dealloc, tp);
1047 }
1048 
1049 void
1050 tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
1051 {
1052 	MPASS(tp->t_sessioncnt > 0);
1053 	tty_lock_assert(tp, MA_OWNED);
1054 
1055 	if (tp->t_pgrp == pg)
1056 		tp->t_pgrp = NULL;
1057 
1058 	tty_unlock(tp);
1059 }
1060 
1061 void
1062 tty_rel_sess(struct tty *tp, struct session *sess)
1063 {
1064 	MPASS(tp->t_sessioncnt > 0);
1065 
1066 	/* Current session has left. */
1067 	if (tp->t_session == sess) {
1068 		tp->t_session = NULL;
1069 		MPASS(tp->t_pgrp == NULL);
1070 	}
1071 	tp->t_sessioncnt--;
1072 	tty_rel_free(tp);
1073 }
1074 
1075 void
1076 tty_rel_gone(struct tty *tp)
1077 {
1078 	MPASS(!tty_gone(tp));
1079 
1080 	/* Simulate carrier removal. */
1081 	ttydisc_modem(tp, 0);
1082 
1083 	/* Wake up all blocked threads. */
1084 	tty_wakeup(tp, FREAD|FWRITE);
1085 	cv_broadcast(&tp->t_bgwait);
1086 	cv_broadcast(&tp->t_dcdwait);
1087 
1088 	tp->t_flags |= TF_GONE;
1089 	tty_rel_free(tp);
1090 }
1091 
1092 /*
1093  * Exposing information about current TTY's through sysctl
1094  */
1095 
1096 static void
1097 tty_to_xtty(struct tty *tp, struct xtty *xt)
1098 {
1099 	tty_lock_assert(tp, MA_OWNED);
1100 
1101 	xt->xt_size = sizeof(struct xtty);
1102 	xt->xt_insize = ttyinq_getsize(&tp->t_inq);
1103 	xt->xt_incc = ttyinq_bytescanonicalized(&tp->t_inq);
1104 	xt->xt_inlc = ttyinq_bytesline(&tp->t_inq);
1105 	xt->xt_inlow = tp->t_inlow;
1106 	xt->xt_outsize = ttyoutq_getsize(&tp->t_outq);
1107 	xt->xt_outcc = ttyoutq_bytesused(&tp->t_outq);
1108 	xt->xt_outlow = tp->t_outlow;
1109 	xt->xt_column = tp->t_column;
1110 	xt->xt_pgid = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
1111 	xt->xt_sid = tp->t_session ? tp->t_session->s_sid : 0;
1112 	xt->xt_flags = tp->t_flags;
1113 	xt->xt_dev = tp->t_dev ? dev2udev(tp->t_dev) : NODEV;
1114 }
1115 
1116 static int
1117 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
1118 {
1119 	unsigned long lsize;
1120 	struct xtty *xtlist, *xt;
1121 	struct tty *tp;
1122 	int error;
1123 
1124 	sx_slock(&tty_list_sx);
1125 	lsize = tty_list_count * sizeof(struct xtty);
1126 	if (lsize == 0) {
1127 		sx_sunlock(&tty_list_sx);
1128 		return (0);
1129 	}
1130 
1131 	xtlist = xt = malloc(lsize, M_TTY, M_WAITOK);
1132 
1133 	TAILQ_FOREACH(tp, &tty_list, t_list) {
1134 		tty_lock(tp);
1135 		tty_to_xtty(tp, xt);
1136 		tty_unlock(tp);
1137 		xt++;
1138 	}
1139 	sx_sunlock(&tty_list_sx);
1140 
1141 	error = SYSCTL_OUT(req, xtlist, lsize);
1142 	free(xtlist, M_TTY);
1143 	return (error);
1144 }
1145 
1146 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
1147 	0, 0, sysctl_kern_ttys, "S,xtty", "List of TTYs");
1148 
1149 /*
1150  * Device node creation. Device has been set up, now we can expose it to
1151  * the user.
1152  */
1153 
1154 void
1155 tty_makedev(struct tty *tp, struct ucred *cred, const char *fmt, ...)
1156 {
1157 	va_list ap;
1158 	struct cdev *dev;
1159 	const char *prefix = "tty";
1160 	char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
1161 	uid_t uid;
1162 	gid_t gid;
1163 	mode_t mode;
1164 
1165 	/* Remove "tty" prefix from devices like PTY's. */
1166 	if (tp->t_flags & TF_NOPREFIX)
1167 		prefix = "";
1168 
1169 	va_start(ap, fmt);
1170 	vsnrprintf(name, sizeof name, 32, fmt, ap);
1171 	va_end(ap);
1172 
1173 	if (cred == NULL) {
1174 		/* System device. */
1175 		uid = UID_ROOT;
1176 		gid = GID_WHEEL;
1177 		mode = S_IRUSR|S_IWUSR;
1178 	} else {
1179 		/* User device. */
1180 		uid = cred->cr_ruid;
1181 		gid = GID_TTY;
1182 		mode = S_IRUSR|S_IWUSR|S_IWGRP;
1183 	}
1184 
1185 	/* Master call-in device. */
1186 	dev = make_dev_cred(&ttydev_cdevsw, 0, cred,
1187 	    uid, gid, mode, "%s%s", prefix, name);
1188 	dev->si_drv1 = tp;
1189 	tp->t_dev = dev;
1190 
1191 	/* Slave call-in devices. */
1192 	if (tp->t_flags & TF_INITLOCK) {
1193 		dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1194 		    uid, gid, mode, "%s%s.init", prefix, name);
1195 		dev_depends(tp->t_dev, dev);
1196 		dev->si_drv1 = tp;
1197 		dev->si_drv2 = &tp->t_termios_init_in;
1198 
1199 		dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1200 		    uid, gid, mode, "%s%s.lock", prefix, name);
1201 		dev_depends(tp->t_dev, dev);
1202 		dev->si_drv1 = tp;
1203 		dev->si_drv2 = &tp->t_termios_lock_in;
1204 	}
1205 
1206 	/* Call-out devices. */
1207 	if (tp->t_flags & TF_CALLOUT) {
1208 		dev = make_dev_cred(&ttydev_cdevsw, 0, cred,
1209 		    UID_UUCP, GID_DIALER, 0660, "cua%s", name);
1210 		dev_depends(tp->t_dev, dev);
1211 		dev->si_drv1 = tp;
1212 
1213 		/* Slave call-out devices. */
1214 		if (tp->t_flags & TF_INITLOCK) {
1215 			dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1216 			    UID_UUCP, GID_DIALER, 0660, "cua%s.init", name);
1217 			dev_depends(tp->t_dev, dev);
1218 			dev->si_drv1 = tp;
1219 			dev->si_drv2 = &tp->t_termios_init_out;
1220 
1221 			dev = make_dev_cred(&ttyil_cdevsw, 0, cred,
1222 			    UID_UUCP, GID_DIALER, 0660, "cua%s.lock", name);
1223 			dev_depends(tp->t_dev, dev);
1224 			dev->si_drv1 = tp;
1225 			dev->si_drv2 = &tp->t_termios_lock_out;
1226 		}
1227 	}
1228 }
1229 
1230 /*
1231  * Signalling processes.
1232  */
1233 
1234 void
1235 tty_signal_sessleader(struct tty *tp, int sig)
1236 {
1237 	struct proc *p;
1238 
1239 	tty_lock_assert(tp, MA_OWNED);
1240 	MPASS(sig >= 1 && sig < NSIG);
1241 
1242 	/* Make signals start output again. */
1243 	tp->t_flags &= ~TF_STOPPED;
1244 
1245 	if (tp->t_session != NULL && tp->t_session->s_leader != NULL) {
1246 		p = tp->t_session->s_leader;
1247 		PROC_LOCK(p);
1248 		psignal(p, sig);
1249 		PROC_UNLOCK(p);
1250 	}
1251 }
1252 
1253 void
1254 tty_signal_pgrp(struct tty *tp, int sig)
1255 {
1256 	ksiginfo_t ksi;
1257 
1258 	tty_lock_assert(tp, MA_OWNED);
1259 	MPASS(sig >= 1 && sig < NSIG);
1260 
1261 	/* Make signals start output again. */
1262 	tp->t_flags &= ~TF_STOPPED;
1263 
1264 	if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
1265 		tty_info(tp);
1266 	if (tp->t_pgrp != NULL) {
1267 		ksiginfo_init(&ksi);
1268 		ksi.ksi_signo = sig;
1269 		ksi.ksi_code = SI_KERNEL;
1270 		PGRP_LOCK(tp->t_pgrp);
1271 		pgsignal(tp->t_pgrp, sig, 1, &ksi);
1272 		PGRP_UNLOCK(tp->t_pgrp);
1273 	}
1274 }
1275 
1276 void
1277 tty_wakeup(struct tty *tp, int flags)
1278 {
1279 	if (tp->t_flags & TF_ASYNC && tp->t_sigio != NULL)
1280 		pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
1281 
1282 	if (flags & FWRITE) {
1283 		cv_broadcast(&tp->t_outwait);
1284 		selwakeup(&tp->t_outpoll);
1285 		KNOTE_LOCKED(&tp->t_outpoll.si_note, 0);
1286 	}
1287 	if (flags & FREAD) {
1288 		cv_broadcast(&tp->t_inwait);
1289 		selwakeup(&tp->t_inpoll);
1290 		KNOTE_LOCKED(&tp->t_inpoll.si_note, 0);
1291 	}
1292 }
1293 
1294 int
1295 tty_wait(struct tty *tp, struct cv *cv)
1296 {
1297 	int error;
1298 	int revokecnt = tp->t_revokecnt;
1299 
1300 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1301 	MPASS(!tty_gone(tp));
1302 
1303 	error = cv_wait_sig(cv, tp->t_mtx);
1304 
1305 	/* Restart the system call when we may have been revoked. */
1306 	if (tp->t_revokecnt != revokecnt)
1307 		return (ERESTART);
1308 
1309 	/* Bail out when the device slipped away. */
1310 	if (tty_gone(tp))
1311 		return (ENXIO);
1312 
1313 	return (error);
1314 }
1315 
1316 int
1317 tty_timedwait(struct tty *tp, struct cv *cv, int hz)
1318 {
1319 	int error;
1320 	int revokecnt = tp->t_revokecnt;
1321 
1322 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1323 	MPASS(!tty_gone(tp));
1324 
1325 	error = cv_timedwait_sig(cv, tp->t_mtx, hz);
1326 
1327 	/* Restart the system call when we may have been revoked. */
1328 	if (tp->t_revokecnt != revokecnt)
1329 		return (ERESTART);
1330 
1331 	/* Bail out when the device slipped away. */
1332 	if (tty_gone(tp))
1333 		return (ENXIO);
1334 
1335 	return (error);
1336 }
1337 
1338 void
1339 tty_flush(struct tty *tp, int flags)
1340 {
1341 	if (flags & FWRITE) {
1342 		tp->t_flags &= ~TF_HIWAT_OUT;
1343 		ttyoutq_flush(&tp->t_outq);
1344 		tty_wakeup(tp, FWRITE);
1345 		ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
1346 	}
1347 	if (flags & FREAD) {
1348 		tty_hiwat_in_unblock(tp);
1349 		ttyinq_flush(&tp->t_inq);
1350 		ttydevsw_inwakeup(tp);
1351 		ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
1352 	}
1353 }
1354 
1355 static int
1356 tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, int fflag,
1357     struct thread *td)
1358 {
1359 	int error;
1360 
1361 	switch (cmd) {
1362 	/*
1363 	 * Modem commands.
1364 	 * The SER_* and TIOCM_* flags are the same, but one bit
1365 	 * shifted. I don't know why.
1366 	 */
1367 	case TIOCSDTR:
1368 		ttydevsw_modem(tp, SER_DTR, 0);
1369 		return (0);
1370 	case TIOCCDTR:
1371 		ttydevsw_modem(tp, 0, SER_DTR);
1372 		return (0);
1373 	case TIOCMSET: {
1374 		int bits = *(int *)data;
1375 		ttydevsw_modem(tp,
1376 		    (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1,
1377 		    ((~bits) & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1378 		return (0);
1379 	}
1380 	case TIOCMBIS: {
1381 		int bits = *(int *)data;
1382 		ttydevsw_modem(tp, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1, 0);
1383 		return (0);
1384 	}
1385 	case TIOCMBIC: {
1386 		int bits = *(int *)data;
1387 		ttydevsw_modem(tp, 0, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1388 		return (0);
1389 	}
1390 	case TIOCMGET:
1391 		*(int *)data = TIOCM_LE + (ttydevsw_modem(tp, 0, 0) << 1);
1392 		return (0);
1393 
1394 	case FIOASYNC:
1395 		if (*(int *)data)
1396 			tp->t_flags |= TF_ASYNC;
1397 		else
1398 			tp->t_flags &= ~TF_ASYNC;
1399 		return (0);
1400 	case FIONBIO:
1401 		/* This device supports non-blocking operation. */
1402 		return (0);
1403 	case FIONREAD:
1404 		*(int *)data = ttyinq_bytescanonicalized(&tp->t_inq);
1405 		return (0);
1406 	case FIONWRITE:
1407 	case TIOCOUTQ:
1408 		*(int *)data = ttyoutq_bytesused(&tp->t_outq);
1409 		return (0);
1410 	case FIOSETOWN:
1411 		if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1412 			/* Not allowed to set ownership. */
1413 			return (ENOTTY);
1414 
1415 		/* Temporarily unlock the TTY to set ownership. */
1416 		tty_unlock(tp);
1417 		error = fsetown(*(int *)data, &tp->t_sigio);
1418 		tty_lock(tp);
1419 		return (error);
1420 	case FIOGETOWN:
1421 		if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1422 			/* Not allowed to set ownership. */
1423 			return (ENOTTY);
1424 
1425 		/* Get ownership. */
1426 		*(int *)data = fgetown(&tp->t_sigio);
1427 		return (0);
1428 	case TIOCGETA:
1429 		/* Obtain terminal flags through tcgetattr(). */
1430 		*(struct termios*)data = tp->t_termios;
1431 		return (0);
1432 	case TIOCSETA:
1433 	case TIOCSETAW:
1434 	case TIOCSETAF: {
1435 		struct termios *t = data;
1436 
1437 		/*
1438 		 * Who makes up these funny rules? According to POSIX,
1439 		 * input baud rate is set equal to the output baud rate
1440 		 * when zero.
1441 		 */
1442 		if (t->c_ispeed == 0)
1443 			t->c_ispeed = t->c_ospeed;
1444 
1445 		/* Discard any unsupported bits. */
1446 		t->c_iflag &= TTYSUP_IFLAG;
1447 		t->c_oflag &= TTYSUP_OFLAG;
1448 		t->c_lflag &= TTYSUP_LFLAG;
1449 		t->c_cflag &= TTYSUP_CFLAG;
1450 
1451 		/* Set terminal flags through tcsetattr(). */
1452 		if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
1453 			error = tty_drain(tp);
1454 			if (error)
1455 				return (error);
1456 			if (cmd == TIOCSETAF)
1457 				tty_flush(tp, FREAD);
1458 		}
1459 
1460 		/*
1461 		 * Only call param() when the flags really change.
1462 		 */
1463 		if ((t->c_cflag & CIGNORE) == 0 &&
1464 		    (tp->t_termios.c_cflag != t->c_cflag ||
1465 		    tp->t_termios.c_ispeed != t->c_ispeed ||
1466 		    tp->t_termios.c_ospeed != t->c_ospeed)) {
1467 			error = ttydevsw_param(tp, t);
1468 			if (error)
1469 				return (error);
1470 
1471 			/* XXX: CLOCAL? */
1472 
1473 			tp->t_termios.c_cflag = t->c_cflag & ~CIGNORE;
1474 			tp->t_termios.c_ispeed = t->c_ispeed;
1475 			tp->t_termios.c_ospeed = t->c_ospeed;
1476 
1477 			/* Baud rate has changed - update watermarks. */
1478 			tty_watermarks(tp);
1479 		}
1480 
1481 		/* Copy new non-device driver parameters. */
1482 		tp->t_termios.c_iflag = t->c_iflag;
1483 		tp->t_termios.c_oflag = t->c_oflag;
1484 		tp->t_termios.c_lflag = t->c_lflag;
1485 		memcpy(&tp->t_termios.c_cc, t->c_cc, sizeof t->c_cc);
1486 
1487 		ttydisc_optimize(tp);
1488 
1489 		if ((t->c_lflag & ICANON) == 0) {
1490 			/*
1491 			 * When in non-canonical mode, wake up all
1492 			 * readers. Canonicalize any partial input. VMIN
1493 			 * and VTIME could also be adjusted.
1494 			 */
1495 			ttyinq_canonicalize(&tp->t_inq);
1496 			tty_wakeup(tp, FREAD);
1497 		}
1498 
1499 		/*
1500 		 * For packet mode: notify the PTY consumer that VSTOP
1501 		 * and VSTART may have been changed.
1502 		 */
1503 		if (tp->t_termios.c_iflag & IXON &&
1504 		    tp->t_termios.c_cc[VSTOP] == CTRL('S') &&
1505 		    tp->t_termios.c_cc[VSTART] == CTRL('Q'))
1506 			ttydevsw_pktnotify(tp, TIOCPKT_DOSTOP);
1507 		else
1508 			ttydevsw_pktnotify(tp, TIOCPKT_NOSTOP);
1509 		return (0);
1510 	}
1511 	case TIOCGETD:
1512 		/* For compatibility - we only support TTYDISC. */
1513 		*(int *)data = TTYDISC;
1514 		return (0);
1515 	case TIOCGPGRP:
1516 		if (!tty_is_ctty(tp, td->td_proc))
1517 			return (ENOTTY);
1518 
1519 		if (tp->t_pgrp != NULL)
1520 			*(int *)data = tp->t_pgrp->pg_id;
1521 		else
1522 			*(int *)data = NO_PID;
1523 		return (0);
1524 	case TIOCGSID:
1525 		if (!tty_is_ctty(tp, td->td_proc))
1526 			return (ENOTTY);
1527 
1528 		MPASS(tp->t_session);
1529 		*(int *)data = tp->t_session->s_sid;
1530 		return (0);
1531 	case TIOCSCTTY: {
1532 		struct proc *p = td->td_proc;
1533 
1534 		/* XXX: This looks awful. */
1535 		tty_unlock(tp);
1536 		sx_xlock(&proctree_lock);
1537 		tty_lock(tp);
1538 
1539 		if (!SESS_LEADER(p)) {
1540 			/* Only the session leader may do this. */
1541 			sx_xunlock(&proctree_lock);
1542 			return (EPERM);
1543 		}
1544 
1545 		if (tp->t_session != NULL && tp->t_session == p->p_session) {
1546 			/* This is already our controlling TTY. */
1547 			sx_xunlock(&proctree_lock);
1548 			return (0);
1549 		}
1550 
1551 		if (p->p_session->s_ttyp != NULL ||
1552 		    (tp->t_session != NULL && tp->t_session->s_ttyvp != NULL &&
1553 		    tp->t_session->s_ttyvp->v_type != VBAD)) {
1554 			/*
1555 			 * There is already a relation between a TTY and
1556 			 * a session, or the caller is not the session
1557 			 * leader.
1558 			 *
1559 			 * Allow the TTY to be stolen when the vnode is
1560 			 * invalid, but the reference to the TTY is
1561 			 * still active.  This allows immediate reuse of
1562 			 * TTYs of which the session leader has been
1563 			 * killed or the TTY revoked.
1564 			 */
1565 			sx_xunlock(&proctree_lock);
1566 			return (EPERM);
1567 		}
1568 
1569 		/* Connect the session to the TTY. */
1570 		tp->t_session = p->p_session;
1571 		tp->t_session->s_ttyp = tp;
1572 		tp->t_sessioncnt++;
1573 		sx_xunlock(&proctree_lock);
1574 
1575 		/* Assign foreground process group. */
1576 		tp->t_pgrp = p->p_pgrp;
1577 		PROC_LOCK(p);
1578 		p->p_flag |= P_CONTROLT;
1579 		PROC_UNLOCK(p);
1580 
1581 		return (0);
1582 	}
1583 	case TIOCSPGRP: {
1584 		struct pgrp *pg;
1585 
1586 		/*
1587 		 * XXX: Temporarily unlock the TTY to locate the process
1588 		 * group. This code would be lot nicer if we would ever
1589 		 * decompose proctree_lock.
1590 		 */
1591 		tty_unlock(tp);
1592 		sx_slock(&proctree_lock);
1593 		pg = pgfind(*(int *)data);
1594 		if (pg != NULL)
1595 			PGRP_UNLOCK(pg);
1596 		if (pg == NULL || pg->pg_session != td->td_proc->p_session) {
1597 			sx_sunlock(&proctree_lock);
1598 			tty_lock(tp);
1599 			return (EPERM);
1600 		}
1601 		tty_lock(tp);
1602 
1603 		/*
1604 		 * Determine if this TTY is the controlling TTY after
1605 		 * relocking the TTY.
1606 		 */
1607 		if (!tty_is_ctty(tp, td->td_proc)) {
1608 			sx_sunlock(&proctree_lock);
1609 			return (ENOTTY);
1610 		}
1611 		tp->t_pgrp = pg;
1612 		sx_sunlock(&proctree_lock);
1613 
1614 		/* Wake up the background process groups. */
1615 		cv_broadcast(&tp->t_bgwait);
1616 		return (0);
1617 	}
1618 	case TIOCFLUSH: {
1619 		int flags = *(int *)data;
1620 
1621 		if (flags == 0)
1622 			flags = (FREAD|FWRITE);
1623 		else
1624 			flags &= (FREAD|FWRITE);
1625 		tty_flush(tp, flags);
1626 		return (0);
1627 	}
1628 	case TIOCDRAIN:
1629 		/* Drain TTY output. */
1630 		return tty_drain(tp);
1631 	case TIOCCONS:
1632 		/* Set terminal as console TTY. */
1633 		if (*(int *)data) {
1634 			error = priv_check(td, PRIV_TTY_CONSOLE);
1635 			if (error)
1636 				return (error);
1637 
1638 			/*
1639 			 * XXX: constty should really need to be locked!
1640 			 * XXX: allow disconnected constty's to be stolen!
1641 			 */
1642 
1643 			if (constty == tp)
1644 				return (0);
1645 			if (constty != NULL)
1646 				return (EBUSY);
1647 
1648 			tty_unlock(tp);
1649 			constty_set(tp);
1650 			tty_lock(tp);
1651 		} else if (constty == tp) {
1652 			constty_clear();
1653 		}
1654 		return (0);
1655 	case TIOCGWINSZ:
1656 		/* Obtain window size. */
1657 		*(struct winsize*)data = tp->t_winsize;
1658 		return (0);
1659 	case TIOCSWINSZ:
1660 		/* Set window size. */
1661 		if (bcmp(&tp->t_winsize, data, sizeof(struct winsize)) == 0)
1662 			return (0);
1663 		tp->t_winsize = *(struct winsize*)data;
1664 		tty_signal_pgrp(tp, SIGWINCH);
1665 		return (0);
1666 	case TIOCEXCL:
1667 		tp->t_flags |= TF_EXCLUDE;
1668 		return (0);
1669 	case TIOCNXCL:
1670 		tp->t_flags &= ~TF_EXCLUDE;
1671 		return (0);
1672 	case TIOCSTOP:
1673 		tp->t_flags |= TF_STOPPED;
1674 		ttydevsw_pktnotify(tp, TIOCPKT_STOP);
1675 		return (0);
1676 	case TIOCSTART:
1677 		tp->t_flags &= ~TF_STOPPED;
1678 		ttydevsw_outwakeup(tp);
1679 		ttydevsw_pktnotify(tp, TIOCPKT_START);
1680 		return (0);
1681 	case TIOCSTAT:
1682 		tty_info(tp);
1683 		return (0);
1684 	case TIOCSTI:
1685 		if ((fflag & FREAD) == 0 && priv_check(td, PRIV_TTY_STI))
1686 			return (EPERM);
1687 		if (!tty_is_ctty(tp, td->td_proc) &&
1688 		    priv_check(td, PRIV_TTY_STI))
1689 			return (EACCES);
1690 		ttydisc_rint(tp, *(char *)data, 0);
1691 		ttydisc_rint_done(tp);
1692 		return (0);
1693 	}
1694 
1695 #ifdef COMPAT_43TTY
1696 	return tty_ioctl_compat(tp, cmd, data, fflag, td);
1697 #else /* !COMPAT_43TTY */
1698 	return (ENOIOCTL);
1699 #endif /* COMPAT_43TTY */
1700 }
1701 
1702 int
1703 tty_ioctl(struct tty *tp, u_long cmd, void *data, int fflag, struct thread *td)
1704 {
1705 	int error;
1706 
1707 	tty_lock_assert(tp, MA_OWNED);
1708 
1709 	if (tty_gone(tp))
1710 		return (ENXIO);
1711 
1712 	error = ttydevsw_ioctl(tp, cmd, data, td);
1713 	if (error == ENOIOCTL)
1714 		error = tty_generic_ioctl(tp, cmd, data, fflag, td);
1715 
1716 	return (error);
1717 }
1718 
1719 dev_t
1720 tty_udev(struct tty *tp)
1721 {
1722 	if (tp->t_dev)
1723 		return dev2udev(tp->t_dev);
1724 	else
1725 		return NODEV;
1726 }
1727 
1728 int
1729 tty_checkoutq(struct tty *tp)
1730 {
1731 
1732 	/* 256 bytes should be enough to print a log message. */
1733 	return (ttyoutq_bytesleft(&tp->t_outq) >= 256);
1734 }
1735 
1736 void
1737 tty_hiwat_in_block(struct tty *tp)
1738 {
1739 
1740 	if ((tp->t_flags & TF_HIWAT_IN) == 0 &&
1741 	    tp->t_termios.c_iflag & IXOFF &&
1742 	    tp->t_termios.c_cc[VSTOP] != _POSIX_VDISABLE) {
1743 		/*
1744 		 * Input flow control. Only enter the high watermark when we
1745 		 * can successfully store the VSTOP character.
1746 		 */
1747 		if (ttyoutq_write_nofrag(&tp->t_outq,
1748 		    &tp->t_termios.c_cc[VSTOP], 1) == 0)
1749 			tp->t_flags |= TF_HIWAT_IN;
1750 	} else {
1751 		/* No input flow control. */
1752 		tp->t_flags |= TF_HIWAT_IN;
1753 	}
1754 }
1755 
1756 void
1757 tty_hiwat_in_unblock(struct tty *tp)
1758 {
1759 
1760 	if (tp->t_flags & TF_HIWAT_IN &&
1761 	    tp->t_termios.c_iflag & IXOFF &&
1762 	    tp->t_termios.c_cc[VSTART] != _POSIX_VDISABLE) {
1763 		/*
1764 		 * Input flow control. Only leave the high watermark when we
1765 		 * can successfully store the VSTART character.
1766 		 */
1767 		if (ttyoutq_write_nofrag(&tp->t_outq,
1768 		    &tp->t_termios.c_cc[VSTART], 1) == 0)
1769 			tp->t_flags &= ~TF_HIWAT_IN;
1770 	} else {
1771 		/* No input flow control. */
1772 		tp->t_flags &= ~TF_HIWAT_IN;
1773 	}
1774 
1775 	if (!tty_gone(tp))
1776 		ttydevsw_inwakeup(tp);
1777 }
1778 
1779 /*
1780  * TTY hooks interface.
1781  */
1782 
1783 static int
1784 ttyhook_defrint(struct tty *tp, char c, int flags)
1785 {
1786 
1787 	if (ttyhook_rint_bypass(tp, &c, 1) != 1)
1788 		return (-1);
1789 
1790 	return (0);
1791 }
1792 
1793 int
1794 ttyhook_register(struct tty **rtp, struct proc *p, int fd,
1795     struct ttyhook *th, void *softc)
1796 {
1797 	struct tty *tp;
1798 	struct file *fp;
1799 	struct cdev *dev;
1800 	struct cdevsw *cdp;
1801 	struct filedesc *fdp;
1802 	int error, ref;
1803 
1804 	/* Validate the file descriptor. */
1805 	if ((fdp = p->p_fd) == NULL)
1806 		return (EBADF);
1807 
1808 	fp = fget_unlocked(fdp, fd);
1809 	if (fp == NULL)
1810 		return (EBADF);
1811 	if (fp->f_ops == &badfileops) {
1812 		error = EBADF;
1813 		goto done1;
1814 	}
1815 
1816 	/*
1817 	 * Make sure the vnode is bound to a character device.
1818 	 * Unlocked check for the vnode type is ok there, because we
1819 	 * only shall prevent calling devvn_refthread on the file that
1820 	 * never has been opened over a character device.
1821 	 */
1822 	if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR) {
1823 		error = EINVAL;
1824 		goto done1;
1825 	}
1826 
1827 	/* Make sure it is a TTY. */
1828 	cdp = devvn_refthread(fp->f_vnode, &dev, &ref);
1829 	if (cdp == NULL) {
1830 		error = ENXIO;
1831 		goto done1;
1832 	}
1833 	if (dev != fp->f_data) {
1834 		error = ENXIO;
1835 		goto done2;
1836 	}
1837 	if (cdp != &ttydev_cdevsw) {
1838 		error = ENOTTY;
1839 		goto done2;
1840 	}
1841 	tp = dev->si_drv1;
1842 
1843 	/* Try to attach the hook to the TTY. */
1844 	error = EBUSY;
1845 	tty_lock(tp);
1846 	MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
1847 	if (tp->t_flags & TF_HOOK)
1848 		goto done3;
1849 
1850 	tp->t_flags |= TF_HOOK;
1851 	tp->t_hook = th;
1852 	tp->t_hooksoftc = softc;
1853 	*rtp = tp;
1854 	error = 0;
1855 
1856 	/* Maybe we can switch into bypass mode now. */
1857 	ttydisc_optimize(tp);
1858 
1859 	/* Silently convert rint() calls to rint_bypass() when possible. */
1860 	if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
1861 		th->th_rint = ttyhook_defrint;
1862 
1863 done3:	tty_unlock(tp);
1864 done2:	dev_relthread(dev, ref);
1865 done1:	fdrop(fp, curthread);
1866 	return (error);
1867 }
1868 
1869 void
1870 ttyhook_unregister(struct tty *tp)
1871 {
1872 
1873 	tty_lock_assert(tp, MA_OWNED);
1874 	MPASS(tp->t_flags & TF_HOOK);
1875 
1876 	/* Disconnect the hook. */
1877 	tp->t_flags &= ~TF_HOOK;
1878 	tp->t_hook = NULL;
1879 
1880 	/* Maybe we need to leave bypass mode. */
1881 	ttydisc_optimize(tp);
1882 
1883 	/* Maybe deallocate the TTY as well. */
1884 	tty_rel_free(tp);
1885 }
1886 
1887 /*
1888  * /dev/console handling.
1889  */
1890 
1891 static int
1892 ttyconsdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
1893 {
1894 	struct tty *tp;
1895 
1896 	/* System has no console device. */
1897 	if (dev_console_filename == NULL)
1898 		return (ENXIO);
1899 
1900 	/* Look up corresponding TTY by device name. */
1901 	sx_slock(&tty_list_sx);
1902 	TAILQ_FOREACH(tp, &tty_list, t_list) {
1903 		if (strcmp(dev_console_filename, tty_devname(tp)) == 0) {
1904 			dev_console->si_drv1 = tp;
1905 			break;
1906 		}
1907 	}
1908 	sx_sunlock(&tty_list_sx);
1909 
1910 	/* System console has no TTY associated. */
1911 	if (dev_console->si_drv1 == NULL)
1912 		return (ENXIO);
1913 
1914 	return (ttydev_open(dev, oflags, devtype, td));
1915 }
1916 
1917 static int
1918 ttyconsdev_write(struct cdev *dev, struct uio *uio, int ioflag)
1919 {
1920 
1921 	log_console(uio);
1922 
1923 	return (ttydev_write(dev, uio, ioflag));
1924 }
1925 
1926 /*
1927  * /dev/console is a little different than normal TTY's.  When opened,
1928  * it determines which TTY to use.  When data gets written to it, it
1929  * will be logged in the kernel message buffer.
1930  */
1931 static struct cdevsw ttyconsdev_cdevsw = {
1932 	.d_version	= D_VERSION,
1933 	.d_open		= ttyconsdev_open,
1934 	.d_close	= ttydev_close,
1935 	.d_read		= ttydev_read,
1936 	.d_write	= ttyconsdev_write,
1937 	.d_ioctl	= ttydev_ioctl,
1938 	.d_kqfilter	= ttydev_kqfilter,
1939 	.d_poll		= ttydev_poll,
1940 	.d_mmap		= ttydev_mmap,
1941 	.d_name		= "ttyconsdev",
1942 	.d_flags	= D_TTY,
1943 };
1944 
1945 static void
1946 ttyconsdev_init(void *unused)
1947 {
1948 
1949 	dev_console = make_dev_credf(MAKEDEV_ETERNAL, &ttyconsdev_cdevsw, 0,
1950 	    NULL, UID_ROOT, GID_WHEEL, 0600, "console");
1951 }
1952 
1953 SYSINIT(tty, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyconsdev_init, NULL);
1954 
1955 void
1956 ttyconsdev_select(const char *name)
1957 {
1958 
1959 	dev_console_filename = name;
1960 }
1961 
1962 /*
1963  * Debugging routines.
1964  */
1965 
1966 #include "opt_ddb.h"
1967 #ifdef DDB
1968 #include <ddb/ddb.h>
1969 #include <ddb/db_sym.h>
1970 
1971 static struct {
1972 	int flag;
1973 	char val;
1974 } ttystates[] = {
1975 #if 0
1976 	{ TF_NOPREFIX,		'N' },
1977 #endif
1978 	{ TF_INITLOCK,		'I' },
1979 	{ TF_CALLOUT,		'C' },
1980 
1981 	/* Keep these together -> 'Oi' and 'Oo'. */
1982 	{ TF_OPENED,		'O' },
1983 	{ TF_OPENED_IN,		'i' },
1984 	{ TF_OPENED_OUT,	'o' },
1985 	{ TF_OPENED_CONS,	'c' },
1986 
1987 	{ TF_GONE,		'G' },
1988 	{ TF_OPENCLOSE,		'B' },
1989 	{ TF_ASYNC,		'Y' },
1990 	{ TF_LITERAL,		'L' },
1991 
1992 	/* Keep these together -> 'Hi' and 'Ho'. */
1993 	{ TF_HIWAT,		'H' },
1994 	{ TF_HIWAT_IN,		'i' },
1995 	{ TF_HIWAT_OUT,		'o' },
1996 
1997 	{ TF_STOPPED,		'S' },
1998 	{ TF_EXCLUDE,		'X' },
1999 	{ TF_BYPASS,		'l' },
2000 	{ TF_ZOMBIE,		'Z' },
2001 	{ TF_HOOK,		's' },
2002 
2003 	/* Keep these together -> 'bi' and 'bo'. */
2004 	{ TF_BUSY,		'b' },
2005 	{ TF_BUSY_IN,		'i' },
2006 	{ TF_BUSY_OUT,		'o' },
2007 
2008 	{ 0,			'\0'},
2009 };
2010 
2011 #define	TTY_FLAG_BITS \
2012 	"\20\1NOPREFIX\2INITLOCK\3CALLOUT\4OPENED_IN\5OPENED_OUT\6GONE" \
2013 	"\7OPENCLOSE\10ASYNC\11LITERAL\12HIWAT_IN\13HIWAT_OUT\14STOPPED" \
2014 	"\15EXCLUDE\16BYPASS\17ZOMBIE\20HOOK"
2015 
2016 #define DB_PRINTSYM(name, addr) \
2017 	db_printf("%s  " #name ": ", sep); \
2018 	db_printsym((db_addr_t) addr, DB_STGY_ANY); \
2019 	db_printf("\n");
2020 
2021 static void
2022 _db_show_devsw(const char *sep, const struct ttydevsw *tsw)
2023 {
2024 	db_printf("%sdevsw: ", sep);
2025 	db_printsym((db_addr_t)tsw, DB_STGY_ANY);
2026 	db_printf(" (%p)\n", tsw);
2027 	DB_PRINTSYM(open, tsw->tsw_open);
2028 	DB_PRINTSYM(close, tsw->tsw_close);
2029 	DB_PRINTSYM(outwakeup, tsw->tsw_outwakeup);
2030 	DB_PRINTSYM(inwakeup, tsw->tsw_inwakeup);
2031 	DB_PRINTSYM(ioctl, tsw->tsw_ioctl);
2032 	DB_PRINTSYM(param, tsw->tsw_param);
2033 	DB_PRINTSYM(modem, tsw->tsw_modem);
2034 	DB_PRINTSYM(mmap, tsw->tsw_mmap);
2035 	DB_PRINTSYM(pktnotify, tsw->tsw_pktnotify);
2036 	DB_PRINTSYM(free, tsw->tsw_free);
2037 }
2038 static void
2039 _db_show_hooks(const char *sep, const struct ttyhook *th)
2040 {
2041 	db_printf("%shook: ", sep);
2042 	db_printsym((db_addr_t)th, DB_STGY_ANY);
2043 	db_printf(" (%p)\n", th);
2044 	if (th == NULL)
2045 		return;
2046 	DB_PRINTSYM(rint, th->th_rint);
2047 	DB_PRINTSYM(rint_bypass, th->th_rint_bypass);
2048 	DB_PRINTSYM(rint_done, th->th_rint_done);
2049 	DB_PRINTSYM(rint_poll, th->th_rint_poll);
2050 	DB_PRINTSYM(getc_inject, th->th_getc_inject);
2051 	DB_PRINTSYM(getc_capture, th->th_getc_capture);
2052 	DB_PRINTSYM(getc_poll, th->th_getc_poll);
2053 	DB_PRINTSYM(close, th->th_close);
2054 }
2055 
2056 static void
2057 _db_show_termios(const char *name, const struct termios *t)
2058 {
2059 
2060 	db_printf("%s: iflag 0x%x oflag 0x%x cflag 0x%x "
2061 	    "lflag 0x%x ispeed %u ospeed %u\n", name,
2062 	    t->c_iflag, t->c_oflag, t->c_cflag, t->c_lflag,
2063 	    t->c_ispeed, t->c_ospeed);
2064 }
2065 
2066 /* DDB command to show TTY statistics. */
2067 DB_SHOW_COMMAND(tty, db_show_tty)
2068 {
2069 	struct tty *tp;
2070 
2071 	if (!have_addr) {
2072 		db_printf("usage: show tty <addr>\n");
2073 		return;
2074 	}
2075 	tp = (struct tty *)addr;
2076 
2077 	db_printf("0x%p: %s\n", tp, tty_devname(tp));
2078 	db_printf("\tmtx: %p\n", tp->t_mtx);
2079 	db_printf("\tflags: %b\n", tp->t_flags, TTY_FLAG_BITS);
2080 	db_printf("\trevokecnt: %u\n", tp->t_revokecnt);
2081 
2082 	/* Buffering mechanisms. */
2083 	db_printf("\tinq: %p begin %u linestart %u reprint %u end %u "
2084 	    "nblocks %u quota %u\n", &tp->t_inq, tp->t_inq.ti_begin,
2085 	    tp->t_inq.ti_linestart, tp->t_inq.ti_reprint, tp->t_inq.ti_end,
2086 	    tp->t_inq.ti_nblocks, tp->t_inq.ti_quota);
2087 	db_printf("\toutq: %p begin %u end %u nblocks %u quota %u\n",
2088 	    &tp->t_outq, tp->t_outq.to_begin, tp->t_outq.to_end,
2089 	    tp->t_outq.to_nblocks, tp->t_outq.to_quota);
2090 	db_printf("\tinlow: %zu\n", tp->t_inlow);
2091 	db_printf("\toutlow: %zu\n", tp->t_outlow);
2092 	_db_show_termios("\ttermios", &tp->t_termios);
2093 	db_printf("\twinsize: row %u col %u xpixel %u ypixel %u\n",
2094 	    tp->t_winsize.ws_row, tp->t_winsize.ws_col,
2095 	    tp->t_winsize.ws_xpixel, tp->t_winsize.ws_ypixel);
2096 	db_printf("\tcolumn: %u\n", tp->t_column);
2097 	db_printf("\twritepos: %u\n", tp->t_writepos);
2098 	db_printf("\tcompatflags: 0x%x\n", tp->t_compatflags);
2099 
2100 	/* Init/lock-state devices. */
2101 	_db_show_termios("\ttermios_init_in", &tp->t_termios_init_in);
2102 	_db_show_termios("\ttermios_init_out", &tp->t_termios_init_out);
2103 	_db_show_termios("\ttermios_lock_in", &tp->t_termios_lock_in);
2104 	_db_show_termios("\ttermios_lock_out", &tp->t_termios_lock_out);
2105 
2106 	/* Hooks */
2107 	_db_show_devsw("\t", tp->t_devsw);
2108 	_db_show_hooks("\t", tp->t_hook);
2109 
2110 	/* Process info. */
2111 	db_printf("\tpgrp: %p gid %d jobc %d\n", tp->t_pgrp,
2112 	    tp->t_pgrp ? tp->t_pgrp->pg_id : 0,
2113 	    tp->t_pgrp ? tp->t_pgrp->pg_jobc : 0);
2114 	db_printf("\tsession: %p", tp->t_session);
2115 	if (tp->t_session != NULL)
2116 	    db_printf(" count %u leader %p tty %p sid %d login %s",
2117 		tp->t_session->s_count, tp->t_session->s_leader,
2118 		tp->t_session->s_ttyp, tp->t_session->s_sid,
2119 		tp->t_session->s_login);
2120 	db_printf("\n");
2121 	db_printf("\tsessioncnt: %u\n", tp->t_sessioncnt);
2122 	db_printf("\tdevswsoftc: %p\n", tp->t_devswsoftc);
2123 	db_printf("\thooksoftc: %p\n", tp->t_hooksoftc);
2124 	db_printf("\tdev: %p\n", tp->t_dev);
2125 }
2126 
2127 /* DDB command to list TTYs. */
2128 DB_SHOW_ALL_COMMAND(ttys, db_show_all_ttys)
2129 {
2130 	struct tty *tp;
2131 	size_t isiz, osiz;
2132 	int i, j;
2133 
2134 	/* Make the output look like `pstat -t'. */
2135 	db_printf("PTR        ");
2136 #if defined(__LP64__)
2137 	db_printf("        ");
2138 #endif
2139 	db_printf("      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   "
2140 	    "COL  SESS  PGID STATE\n");
2141 
2142 	TAILQ_FOREACH(tp, &tty_list, t_list) {
2143 		isiz = tp->t_inq.ti_nblocks * TTYINQ_DATASIZE;
2144 		osiz = tp->t_outq.to_nblocks * TTYOUTQ_DATASIZE;
2145 
2146 		db_printf("%p %10s %5zu %4u %4u %4zu %5zu %4u %4zu %5u %5d %5d ",
2147 		    tp,
2148 		    tty_devname(tp),
2149 		    isiz,
2150 		    tp->t_inq.ti_linestart - tp->t_inq.ti_begin,
2151 		    tp->t_inq.ti_end - tp->t_inq.ti_linestart,
2152 		    isiz - tp->t_inlow,
2153 		    osiz,
2154 		    tp->t_outq.to_end - tp->t_outq.to_begin,
2155 		    osiz - tp->t_outlow,
2156 		    MIN(tp->t_column, 99999),
2157 		    tp->t_session ? tp->t_session->s_sid : 0,
2158 		    tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
2159 
2160 		/* Flag bits. */
2161 		for (i = j = 0; ttystates[i].flag; i++)
2162 			if (tp->t_flags & ttystates[i].flag) {
2163 				db_printf("%c", ttystates[i].val);
2164 				j++;
2165 			}
2166 		if (j == 0)
2167 			db_printf("-");
2168 		db_printf("\n");
2169 	}
2170 }
2171 #endif /* DDB */
2172