xref: /freebsd/sys/kern/tty.c (revision 1d02df3a10859833e19d36cfc0e14d0102b7bbd1)
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_capsicum.h"
34 #include "opt_compat.h"
35 
36 #include <sys/param.h>
37 #include <sys/capsicum.h>
38 #include <sys/conf.h>
39 #include <sys/cons.h>
40 #include <sys/fcntl.h>
41 #include <sys/file.h>
42 #include <sys/filedesc.h>
43 #include <sys/filio.h>
44 #ifdef COMPAT_43TTY
45 #include <sys/ioctl_compat.h>
46 #endif /* COMPAT_43TTY */
47 #include <sys/kernel.h>
48 #include <sys/limits.h>
49 #include <sys/malloc.h>
50 #include <sys/mount.h>
51 #include <sys/poll.h>
52 #include <sys/priv.h>
53 #include <sys/proc.h>
54 #include <sys/serial.h>
55 #include <sys/signal.h>
56 #include <sys/stat.h>
57 #include <sys/sx.h>
58 #include <sys/sysctl.h>
59 #include <sys/systm.h>
60 #include <sys/tty.h>
61 #include <sys/ttycom.h>
62 #define TTYDEFCHARS
63 #include <sys/ttydefaults.h>
64 #undef TTYDEFCHARS
65 #include <sys/ucred.h>
66 #include <sys/vnode.h>
67 
68 #include <machine/stdarg.h>
69 
70 static MALLOC_DEFINE(M_TTY, "tty", "tty device");
71 
72 static void tty_rel_free(struct tty *tp);
73 
74 static TAILQ_HEAD(, tty) tty_list = TAILQ_HEAD_INITIALIZER(tty_list);
75 static struct sx tty_list_sx;
76 SX_SYSINIT(tty_list, &tty_list_sx, "tty list");
77 static unsigned int tty_list_count = 0;
78 
79 /* Character device of /dev/console. */
80 static struct cdev	*dev_console;
81 static const char	*dev_console_filename;
82 
83 /*
84  * Flags that are supported and stored by this implementation.
85  */
86 #define TTYSUP_IFLAG	(IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK|ISTRIP|\
87 			INLCR|IGNCR|ICRNL|IXON|IXOFF|IXANY|IMAXBEL)
88 #define TTYSUP_OFLAG	(OPOST|ONLCR|TAB3|ONOEOT|OCRNL|ONOCR|ONLRET)
89 #define TTYSUP_LFLAG	(ECHOKE|ECHOE|ECHOK|ECHO|ECHONL|ECHOPRT|\
90 			ECHOCTL|ISIG|ICANON|ALTWERASE|IEXTEN|TOSTOP|\
91 			FLUSHO|NOKERNINFO|NOFLSH)
92 #define TTYSUP_CFLAG	(CIGNORE|CSIZE|CSTOPB|CREAD|PARENB|PARODD|\
93 			HUPCL|CLOCAL|CCTS_OFLOW|CRTS_IFLOW|CDTR_IFLOW|\
94 			CDSR_OFLOW|CCAR_OFLOW)
95 
96 #define	TTY_CALLOUT(tp,d) (dev2unit(d) & TTYUNIT_CALLOUT)
97 
98 /*
99  * Set TTY buffer sizes.
100  */
101 
102 #define	TTYBUF_MAX	65536
103 
104 static void
105 tty_watermarks(struct tty *tp)
106 {
107 	size_t bs = 0;
108 
109 	/* Provide an input buffer for 0.2 seconds of data. */
110 	if (tp->t_termios.c_cflag & CREAD)
111 		bs = MIN(tp->t_termios.c_ispeed / 5, TTYBUF_MAX);
112 	ttyinq_setsize(&tp->t_inq, tp, bs);
113 
114 	/* Set low watermark at 10% (when 90% is available). */
115 	tp->t_inlow = (ttyinq_getallocatedsize(&tp->t_inq) * 9) / 10;
116 
117 	/* Provide an output buffer for 0.2 seconds of data. */
118 	bs = MIN(tp->t_termios.c_ospeed / 5, TTYBUF_MAX);
119 	ttyoutq_setsize(&tp->t_outq, tp, bs);
120 
121 	/* Set low watermark at 10% (when 90% is available). */
122 	tp->t_outlow = (ttyoutq_getallocatedsize(&tp->t_outq) * 9) / 10;
123 }
124 
125 static int
126 tty_drain(struct tty *tp, int leaving)
127 {
128 	size_t bytesused;
129 	int error, revokecnt;
130 
131 	if (ttyhook_hashook(tp, getc_inject))
132 		/* buffer is inaccessible */
133 		return (0);
134 
135 	while (ttyoutq_bytesused(&tp->t_outq) > 0 || ttydevsw_busy(tp)) {
136 		ttydevsw_outwakeup(tp);
137 		/* Could be handled synchronously. */
138 		bytesused = ttyoutq_bytesused(&tp->t_outq);
139 		if (bytesused == 0 && !ttydevsw_busy(tp))
140 			return (0);
141 
142 		/* Wait for data to be drained. */
143 		if (leaving) {
144 			revokecnt = tp->t_revokecnt;
145 			error = tty_timedwait(tp, &tp->t_outwait, hz);
146 			switch (error) {
147 			case ERESTART:
148 				if (revokecnt != tp->t_revokecnt)
149 					error = 0;
150 				break;
151 			case EWOULDBLOCK:
152 				if (ttyoutq_bytesused(&tp->t_outq) < bytesused)
153 					error = 0;
154 				break;
155 			}
156 		} else
157 			error = tty_wait(tp, &tp->t_outwait);
158 
159 		if (error)
160 			return (error);
161 	}
162 
163 	return (0);
164 }
165 
166 /*
167  * Though ttydev_enter() and ttydev_leave() seem to be related, they
168  * don't have to be used together. ttydev_enter() is used by the cdev
169  * operations to prevent an actual operation from being processed when
170  * the TTY has been abandoned. ttydev_leave() is used by ttydev_open()
171  * and ttydev_close() to determine whether per-TTY data should be
172  * deallocated.
173  */
174 
175 static __inline int
176 ttydev_enter(struct tty *tp)
177 {
178 	tty_lock(tp);
179 
180 	if (tty_gone(tp) || !tty_opened(tp)) {
181 		/* Device is already gone. */
182 		tty_unlock(tp);
183 		return (ENXIO);
184 	}
185 
186 	return (0);
187 }
188 
189 static void
190 ttydev_leave(struct tty *tp)
191 {
192 	tty_lock_assert(tp, MA_OWNED);
193 
194 	if (tty_opened(tp) || tp->t_flags & TF_OPENCLOSE) {
195 		/* Device is still opened somewhere. */
196 		tty_unlock(tp);
197 		return;
198 	}
199 
200 	tp->t_flags |= TF_OPENCLOSE;
201 
202 	/* Stop asynchronous I/O. */
203 	funsetown(&tp->t_sigio);
204 
205 	/* Remove console TTY. */
206 	if (constty == tp)
207 		constty_clear();
208 
209 	/* Drain any output. */
210 	MPASS((tp->t_flags & TF_STOPPED) == 0);
211 	if (!tty_gone(tp))
212 		tty_drain(tp, 1);
213 
214 	ttydisc_close(tp);
215 
216 	/* Free i/o queues now since they might be large. */
217 	ttyinq_free(&tp->t_inq);
218 	tp->t_inlow = 0;
219 	ttyoutq_free(&tp->t_outq);
220 	tp->t_outlow = 0;
221 
222 	knlist_clear(&tp->t_inpoll.si_note, 1);
223 	knlist_clear(&tp->t_outpoll.si_note, 1);
224 
225 	if (!tty_gone(tp))
226 		ttydevsw_close(tp);
227 
228 	tp->t_flags &= ~TF_OPENCLOSE;
229 	cv_broadcast(&tp->t_dcdwait);
230 	tty_rel_free(tp);
231 }
232 
233 /*
234  * Operations that are exposed through the character device in /dev.
235  */
236 static int
237 ttydev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
238 {
239 	struct tty *tp;
240 	int error;
241 
242 	tp = dev->si_drv1;
243 	error = 0;
244 	tty_lock(tp);
245 	if (tty_gone(tp)) {
246 		/* Device is already gone. */
247 		tty_unlock(tp);
248 		return (ENXIO);
249 	}
250 
251 	/*
252 	 * Block when other processes are currently opening or closing
253 	 * the TTY.
254 	 */
255 	while (tp->t_flags & TF_OPENCLOSE) {
256 		error = tty_wait(tp, &tp->t_dcdwait);
257 		if (error != 0) {
258 			tty_unlock(tp);
259 			return (error);
260 		}
261 	}
262 	tp->t_flags |= TF_OPENCLOSE;
263 
264 	/*
265 	 * Make sure the "tty" and "cua" device cannot be opened at the
266 	 * same time.
267 	 */
268 	if (TTY_CALLOUT(tp, dev)) {
269 		if (tp->t_flags & TF_OPENED_IN) {
270 			error = EBUSY;
271 			goto done;
272 		}
273 	} else {
274 		if (tp->t_flags & TF_OPENED_OUT) {
275 			error = EBUSY;
276 			goto done;
277 		}
278 	}
279 
280 	if (tp->t_flags & TF_EXCLUDE && priv_check(td, PRIV_TTY_EXCLUSIVE)) {
281 		error = EBUSY;
282 		goto done;
283 	}
284 
285 	if (!tty_opened(tp)) {
286 		/* Set proper termios flags. */
287 		if (TTY_CALLOUT(tp, dev))
288 			tp->t_termios = tp->t_termios_init_out;
289 		else
290 			tp->t_termios = tp->t_termios_init_in;
291 		ttydevsw_param(tp, &tp->t_termios);
292 		/* Prevent modem control on callout devices and /dev/console. */
293 		if (TTY_CALLOUT(tp, dev) || dev == dev_console)
294 			tp->t_termios.c_cflag |= CLOCAL;
295 
296 		ttydevsw_modem(tp, SER_DTR|SER_RTS, 0);
297 
298 		error = ttydevsw_open(tp);
299 		if (error != 0)
300 			goto done;
301 
302 		ttydisc_open(tp);
303 		tty_watermarks(tp); /* XXXGL: drops lock */
304 	}
305 
306 	/* Wait for Carrier Detect. */
307 	if ((oflags & O_NONBLOCK) == 0 &&
308 	    (tp->t_termios.c_cflag & CLOCAL) == 0) {
309 		while ((ttydevsw_modem(tp, 0, 0) & SER_DCD) == 0) {
310 			error = tty_wait(tp, &tp->t_dcdwait);
311 			if (error != 0)
312 				goto done;
313 		}
314 	}
315 
316 	if (dev == dev_console)
317 		tp->t_flags |= TF_OPENED_CONS;
318 	else if (TTY_CALLOUT(tp, dev))
319 		tp->t_flags |= TF_OPENED_OUT;
320 	else
321 		tp->t_flags |= TF_OPENED_IN;
322 
323 done:	tp->t_flags &= ~TF_OPENCLOSE;
324 	cv_broadcast(&tp->t_dcdwait);
325 	ttydev_leave(tp);
326 
327 	return (error);
328 }
329 
330 static int
331 ttydev_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
332 {
333 	struct tty *tp = dev->si_drv1;
334 
335 	tty_lock(tp);
336 
337 	/*
338 	 * Don't actually close the device if it is being used as the
339 	 * console.
340 	 */
341 	MPASS((tp->t_flags & TF_OPENED) != TF_OPENED);
342 	if (dev == dev_console)
343 		tp->t_flags &= ~TF_OPENED_CONS;
344 	else
345 		tp->t_flags &= ~(TF_OPENED_IN|TF_OPENED_OUT);
346 
347 	if (tp->t_flags & TF_OPENED) {
348 		tty_unlock(tp);
349 		return (0);
350 	}
351 
352 	/*
353 	 * This can only be called once. The callin and the callout
354 	 * devices cannot be opened at the same time.
355 	 */
356 	tp->t_flags &= ~(TF_EXCLUDE|TF_STOPPED);
357 
358 	/* Properly wake up threads that are stuck - revoke(). */
359 	tp->t_revokecnt++;
360 	tty_wakeup(tp, FREAD|FWRITE);
361 	cv_broadcast(&tp->t_bgwait);
362 	cv_broadcast(&tp->t_dcdwait);
363 
364 	ttydev_leave(tp);
365 
366 	return (0);
367 }
368 
369 static __inline int
370 tty_is_ctty(struct tty *tp, struct proc *p)
371 {
372 	tty_lock_assert(tp, MA_OWNED);
373 
374 	return (p->p_session == tp->t_session && p->p_flag & P_CONTROLT);
375 }
376 
377 int
378 tty_wait_background(struct tty *tp, struct thread *td, int sig)
379 {
380 	struct proc *p = td->td_proc;
381 	struct pgrp *pg;
382 	ksiginfo_t ksi;
383 	int error;
384 
385 	MPASS(sig == SIGTTIN || sig == SIGTTOU);
386 	tty_lock_assert(tp, MA_OWNED);
387 
388 	for (;;) {
389 		PROC_LOCK(p);
390 		/*
391 		 * The process should only sleep, when:
392 		 * - This terminal is the controling terminal
393 		 * - Its process group is not the foreground process
394 		 *   group
395 		 * - The parent process isn't waiting for the child to
396 		 *   exit
397 		 * - the signal to send to the process isn't masked
398 		 */
399 		if (!tty_is_ctty(tp, p) || p->p_pgrp == tp->t_pgrp) {
400 			/* Allow the action to happen. */
401 			PROC_UNLOCK(p);
402 			return (0);
403 		}
404 
405 		if (SIGISMEMBER(p->p_sigacts->ps_sigignore, sig) ||
406 		    SIGISMEMBER(td->td_sigmask, sig)) {
407 			/* Only allow them in write()/ioctl(). */
408 			PROC_UNLOCK(p);
409 			return (sig == SIGTTOU ? 0 : EIO);
410 		}
411 
412 		pg = p->p_pgrp;
413 		if (p->p_flag & P_PPWAIT || pg->pg_jobc == 0) {
414 			/* Don't allow the action to happen. */
415 			PROC_UNLOCK(p);
416 			return (EIO);
417 		}
418 		PROC_UNLOCK(p);
419 
420 		/*
421 		 * Send the signal and sleep until we're the new
422 		 * foreground process group.
423 		 */
424 		if (sig != 0) {
425 			ksiginfo_init(&ksi);
426 			ksi.ksi_code = SI_KERNEL;
427 			ksi.ksi_signo = sig;
428 			sig = 0;
429 		}
430 		PGRP_LOCK(pg);
431 		pgsignal(pg, ksi.ksi_signo, 1, &ksi);
432 		PGRP_UNLOCK(pg);
433 
434 		error = tty_wait(tp, &tp->t_bgwait);
435 		if (error)
436 			return (error);
437 	}
438 }
439 
440 static int
441 ttydev_read(struct cdev *dev, struct uio *uio, int ioflag)
442 {
443 	struct tty *tp = dev->si_drv1;
444 	int error;
445 
446 	error = ttydev_enter(tp);
447 	if (error)
448 		goto done;
449 	error = ttydisc_read(tp, uio, ioflag);
450 	tty_unlock(tp);
451 
452 	/*
453 	 * The read() call should not throw an error when the device is
454 	 * being destroyed. Silently convert it to an EOF.
455 	 */
456 done:	if (error == ENXIO)
457 		error = 0;
458 	return (error);
459 }
460 
461 static int
462 ttydev_write(struct cdev *dev, struct uio *uio, int ioflag)
463 {
464 	struct tty *tp = dev->si_drv1;
465 	int error;
466 
467 	error = ttydev_enter(tp);
468 	if (error)
469 		return (error);
470 
471 	if (tp->t_termios.c_lflag & TOSTOP) {
472 		error = tty_wait_background(tp, curthread, SIGTTOU);
473 		if (error)
474 			goto done;
475 	}
476 
477 	if (ioflag & IO_NDELAY && tp->t_flags & TF_BUSY_OUT) {
478 		/* Allow non-blocking writes to bypass serialization. */
479 		error = ttydisc_write(tp, uio, ioflag);
480 	} else {
481 		/* Serialize write() calls. */
482 		while (tp->t_flags & TF_BUSY_OUT) {
483 			error = tty_wait(tp, &tp->t_outserwait);
484 			if (error)
485 				goto done;
486 		}
487 
488 		tp->t_flags |= TF_BUSY_OUT;
489 		error = ttydisc_write(tp, uio, ioflag);
490 		tp->t_flags &= ~TF_BUSY_OUT;
491 		cv_signal(&tp->t_outserwait);
492 	}
493 
494 done:	tty_unlock(tp);
495 	return (error);
496 }
497 
498 static int
499 ttydev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
500     struct thread *td)
501 {
502 	struct tty *tp = dev->si_drv1;
503 	int error;
504 
505 	error = ttydev_enter(tp);
506 	if (error)
507 		return (error);
508 
509 	switch (cmd) {
510 	case TIOCCBRK:
511 	case TIOCCONS:
512 	case TIOCDRAIN:
513 	case TIOCEXCL:
514 	case TIOCFLUSH:
515 	case TIOCNXCL:
516 	case TIOCSBRK:
517 	case TIOCSCTTY:
518 	case TIOCSETA:
519 	case TIOCSETAF:
520 	case TIOCSETAW:
521 	case TIOCSPGRP:
522 	case TIOCSTART:
523 	case TIOCSTAT:
524 	case TIOCSTI:
525 	case TIOCSTOP:
526 	case TIOCSWINSZ:
527 #if 0
528 	case TIOCSDRAINWAIT:
529 	case TIOCSETD:
530 #endif
531 #ifdef COMPAT_43TTY
532 	case  TIOCLBIC:
533 	case  TIOCLBIS:
534 	case  TIOCLSET:
535 	case  TIOCSETC:
536 	case OTIOCSETD:
537 	case  TIOCSETN:
538 	case  TIOCSETP:
539 	case  TIOCSLTC:
540 #endif /* COMPAT_43TTY */
541 		/*
542 		 * If the ioctl() causes the TTY to be modified, let it
543 		 * wait in the background.
544 		 */
545 		error = tty_wait_background(tp, curthread, SIGTTOU);
546 		if (error)
547 			goto done;
548 	}
549 
550 	if (cmd == TIOCSETA || cmd == TIOCSETAW || cmd == TIOCSETAF) {
551 		struct termios *old = &tp->t_termios;
552 		struct termios *new = (struct termios *)data;
553 		struct termios *lock = TTY_CALLOUT(tp, dev) ?
554 		    &tp->t_termios_lock_out : &tp->t_termios_lock_in;
555 		int cc;
556 
557 		/*
558 		 * Lock state devices.  Just overwrite the values of the
559 		 * commands that are currently in use.
560 		 */
561 		new->c_iflag = (old->c_iflag & lock->c_iflag) |
562 		    (new->c_iflag & ~lock->c_iflag);
563 		new->c_oflag = (old->c_oflag & lock->c_oflag) |
564 		    (new->c_oflag & ~lock->c_oflag);
565 		new->c_cflag = (old->c_cflag & lock->c_cflag) |
566 		    (new->c_cflag & ~lock->c_cflag);
567 		new->c_lflag = (old->c_lflag & lock->c_lflag) |
568 		    (new->c_lflag & ~lock->c_lflag);
569 		for (cc = 0; cc < NCCS; ++cc)
570 			if (lock->c_cc[cc])
571 				new->c_cc[cc] = old->c_cc[cc];
572 		if (lock->c_ispeed)
573 			new->c_ispeed = old->c_ispeed;
574 		if (lock->c_ospeed)
575 			new->c_ospeed = old->c_ospeed;
576 	}
577 
578 	error = tty_ioctl(tp, cmd, data, fflag, td);
579 done:	tty_unlock(tp);
580 
581 	return (error);
582 }
583 
584 static int
585 ttydev_poll(struct cdev *dev, int events, struct thread *td)
586 {
587 	struct tty *tp = dev->si_drv1;
588 	int error, revents = 0;
589 
590 	error = ttydev_enter(tp);
591 	if (error)
592 		return ((events & (POLLIN|POLLRDNORM)) | POLLHUP);
593 
594 	if (events & (POLLIN|POLLRDNORM)) {
595 		/* See if we can read something. */
596 		if (ttydisc_read_poll(tp) > 0)
597 			revents |= events & (POLLIN|POLLRDNORM);
598 	}
599 
600 	if (tp->t_flags & TF_ZOMBIE) {
601 		/* Hangup flag on zombie state. */
602 		revents |= POLLHUP;
603 	} else if (events & (POLLOUT|POLLWRNORM)) {
604 		/* See if we can write something. */
605 		if (ttydisc_write_poll(tp) > 0)
606 			revents |= events & (POLLOUT|POLLWRNORM);
607 	}
608 
609 	if (revents == 0) {
610 		if (events & (POLLIN|POLLRDNORM))
611 			selrecord(td, &tp->t_inpoll);
612 		if (events & (POLLOUT|POLLWRNORM))
613 			selrecord(td, &tp->t_outpoll);
614 	}
615 
616 	tty_unlock(tp);
617 
618 	return (revents);
619 }
620 
621 static int
622 ttydev_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
623     int nprot, vm_memattr_t *memattr)
624 {
625 	struct tty *tp = dev->si_drv1;
626 	int error;
627 
628 	/* Handle mmap() through the driver. */
629 
630 	error = ttydev_enter(tp);
631 	if (error)
632 		return (-1);
633 	error = ttydevsw_mmap(tp, offset, paddr, nprot, memattr);
634 	tty_unlock(tp);
635 
636 	return (error);
637 }
638 
639 /*
640  * kqueue support.
641  */
642 
643 static void
644 tty_kqops_read_detach(struct knote *kn)
645 {
646 	struct tty *tp = kn->kn_hook;
647 
648 	knlist_remove(&tp->t_inpoll.si_note, kn, 0);
649 }
650 
651 static int
652 tty_kqops_read_event(struct knote *kn, long hint)
653 {
654 	struct tty *tp = kn->kn_hook;
655 
656 	tty_lock_assert(tp, MA_OWNED);
657 
658 	if (tty_gone(tp) || tp->t_flags & TF_ZOMBIE) {
659 		kn->kn_flags |= EV_EOF;
660 		return (1);
661 	} else {
662 		kn->kn_data = ttydisc_read_poll(tp);
663 		return (kn->kn_data > 0);
664 	}
665 }
666 
667 static void
668 tty_kqops_write_detach(struct knote *kn)
669 {
670 	struct tty *tp = kn->kn_hook;
671 
672 	knlist_remove(&tp->t_outpoll.si_note, kn, 0);
673 }
674 
675 static int
676 tty_kqops_write_event(struct knote *kn, long hint)
677 {
678 	struct tty *tp = kn->kn_hook;
679 
680 	tty_lock_assert(tp, MA_OWNED);
681 
682 	if (tty_gone(tp)) {
683 		kn->kn_flags |= EV_EOF;
684 		return (1);
685 	} else {
686 		kn->kn_data = ttydisc_write_poll(tp);
687 		return (kn->kn_data > 0);
688 	}
689 }
690 
691 static struct filterops tty_kqops_read = {
692 	.f_isfd = 1,
693 	.f_detach = tty_kqops_read_detach,
694 	.f_event = tty_kqops_read_event,
695 };
696 static struct filterops tty_kqops_write = {
697 	.f_isfd = 1,
698 	.f_detach = tty_kqops_write_detach,
699 	.f_event = tty_kqops_write_event,
700 };
701 
702 static int
703 ttydev_kqfilter(struct cdev *dev, struct knote *kn)
704 {
705 	struct tty *tp = dev->si_drv1;
706 	int error;
707 
708 	error = ttydev_enter(tp);
709 	if (error)
710 		return (error);
711 
712 	switch (kn->kn_filter) {
713 	case EVFILT_READ:
714 		kn->kn_hook = tp;
715 		kn->kn_fop = &tty_kqops_read;
716 		knlist_add(&tp->t_inpoll.si_note, kn, 1);
717 		break;
718 	case EVFILT_WRITE:
719 		kn->kn_hook = tp;
720 		kn->kn_fop = &tty_kqops_write;
721 		knlist_add(&tp->t_outpoll.si_note, kn, 1);
722 		break;
723 	default:
724 		error = EINVAL;
725 		break;
726 	}
727 
728 	tty_unlock(tp);
729 	return (error);
730 }
731 
732 static struct cdevsw ttydev_cdevsw = {
733 	.d_version	= D_VERSION,
734 	.d_open		= ttydev_open,
735 	.d_close	= ttydev_close,
736 	.d_read		= ttydev_read,
737 	.d_write	= ttydev_write,
738 	.d_ioctl	= ttydev_ioctl,
739 	.d_kqfilter	= ttydev_kqfilter,
740 	.d_poll		= ttydev_poll,
741 	.d_mmap		= ttydev_mmap,
742 	.d_name		= "ttydev",
743 	.d_flags	= D_TTY,
744 };
745 
746 /*
747  * Init/lock-state devices
748  */
749 
750 static int
751 ttyil_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
752 {
753 	struct tty *tp;
754 	int error;
755 
756 	tp = dev->si_drv1;
757 	error = 0;
758 	tty_lock(tp);
759 	if (tty_gone(tp))
760 		error = ENODEV;
761 	tty_unlock(tp);
762 
763 	return (error);
764 }
765 
766 static int
767 ttyil_close(struct cdev *dev, int flag, int mode, struct thread *td)
768 {
769 	return (0);
770 }
771 
772 static int
773 ttyil_rdwr(struct cdev *dev, struct uio *uio, int ioflag)
774 {
775 	return (ENODEV);
776 }
777 
778 static int
779 ttyil_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
780     struct thread *td)
781 {
782 	struct tty *tp = dev->si_drv1;
783 	int error;
784 
785 	tty_lock(tp);
786 	if (tty_gone(tp)) {
787 		error = ENODEV;
788 		goto done;
789 	}
790 
791 	error = ttydevsw_cioctl(tp, dev2unit(dev), cmd, data, td);
792 	if (error != ENOIOCTL)
793 		goto done;
794 	error = 0;
795 
796 	switch (cmd) {
797 	case TIOCGETA:
798 		/* Obtain terminal flags through tcgetattr(). */
799 		*(struct termios*)data = *(struct termios*)dev->si_drv2;
800 		break;
801 	case TIOCSETA:
802 		/* Set terminal flags through tcsetattr(). */
803 		error = priv_check(td, PRIV_TTY_SETA);
804 		if (error)
805 			break;
806 		*(struct termios*)dev->si_drv2 = *(struct termios*)data;
807 		break;
808 	case TIOCGETD:
809 		*(int *)data = TTYDISC;
810 		break;
811 	case TIOCGWINSZ:
812 		bzero(data, sizeof(struct winsize));
813 		break;
814 	default:
815 		error = ENOTTY;
816 	}
817 
818 done:	tty_unlock(tp);
819 	return (error);
820 }
821 
822 static struct cdevsw ttyil_cdevsw = {
823 	.d_version	= D_VERSION,
824 	.d_open		= ttyil_open,
825 	.d_close	= ttyil_close,
826 	.d_read		= ttyil_rdwr,
827 	.d_write	= ttyil_rdwr,
828 	.d_ioctl	= ttyil_ioctl,
829 	.d_name		= "ttyil",
830 	.d_flags	= D_TTY,
831 };
832 
833 static void
834 tty_init_termios(struct tty *tp)
835 {
836 	struct termios *t = &tp->t_termios_init_in;
837 
838 	t->c_cflag = TTYDEF_CFLAG;
839 	t->c_iflag = TTYDEF_IFLAG;
840 	t->c_lflag = TTYDEF_LFLAG;
841 	t->c_oflag = TTYDEF_OFLAG;
842 	t->c_ispeed = TTYDEF_SPEED;
843 	t->c_ospeed = TTYDEF_SPEED;
844 	memcpy(&t->c_cc, ttydefchars, sizeof ttydefchars);
845 
846 	tp->t_termios_init_out = *t;
847 }
848 
849 void
850 tty_init_console(struct tty *tp, speed_t s)
851 {
852 	struct termios *ti = &tp->t_termios_init_in;
853 	struct termios *to = &tp->t_termios_init_out;
854 
855 	if (s != 0) {
856 		ti->c_ispeed = ti->c_ospeed = s;
857 		to->c_ispeed = to->c_ospeed = s;
858 	}
859 
860 	ti->c_cflag |= CLOCAL;
861 	to->c_cflag |= CLOCAL;
862 }
863 
864 /*
865  * Standard device routine implementations, mostly meant for
866  * pseudo-terminal device drivers. When a driver creates a new terminal
867  * device class, missing routines are patched.
868  */
869 
870 static int
871 ttydevsw_defopen(struct tty *tp)
872 {
873 
874 	return (0);
875 }
876 
877 static void
878 ttydevsw_defclose(struct tty *tp)
879 {
880 }
881 
882 static void
883 ttydevsw_defoutwakeup(struct tty *tp)
884 {
885 
886 	panic("Terminal device has output, while not implemented");
887 }
888 
889 static void
890 ttydevsw_definwakeup(struct tty *tp)
891 {
892 }
893 
894 static int
895 ttydevsw_defioctl(struct tty *tp, u_long cmd, caddr_t data, struct thread *td)
896 {
897 
898 	return (ENOIOCTL);
899 }
900 
901 static int
902 ttydevsw_defcioctl(struct tty *tp, int unit, u_long cmd, caddr_t data, struct thread *td)
903 {
904 
905 	return (ENOIOCTL);
906 }
907 
908 static int
909 ttydevsw_defparam(struct tty *tp, struct termios *t)
910 {
911 
912 	/*
913 	 * Allow the baud rate to be adjusted for pseudo-devices, but at
914 	 * least restrict it to 115200 to prevent excessive buffer
915 	 * usage.  Also disallow 0, to prevent foot shooting.
916 	 */
917 	if (t->c_ispeed < B50)
918 		t->c_ispeed = B50;
919 	else if (t->c_ispeed > B115200)
920 		t->c_ispeed = B115200;
921 	if (t->c_ospeed < B50)
922 		t->c_ospeed = B50;
923 	else if (t->c_ospeed > B115200)
924 		t->c_ospeed = B115200;
925 	t->c_cflag |= CREAD;
926 
927 	return (0);
928 }
929 
930 static int
931 ttydevsw_defmodem(struct tty *tp, int sigon, int sigoff)
932 {
933 
934 	/* Simulate a carrier to make the TTY layer happy. */
935 	return (SER_DCD);
936 }
937 
938 static int
939 ttydevsw_defmmap(struct tty *tp, vm_ooffset_t offset, vm_paddr_t *paddr,
940     int nprot, vm_memattr_t *memattr)
941 {
942 
943 	return (-1);
944 }
945 
946 static void
947 ttydevsw_defpktnotify(struct tty *tp, char event)
948 {
949 }
950 
951 static void
952 ttydevsw_deffree(void *softc)
953 {
954 
955 	panic("Terminal device freed without a free-handler");
956 }
957 
958 static bool
959 ttydevsw_defbusy(struct tty *tp __unused)
960 {
961 
962 	return (FALSE);
963 }
964 
965 /*
966  * TTY allocation and deallocation. TTY devices can be deallocated when
967  * the driver doesn't use it anymore, when the TTY isn't a session's
968  * controlling TTY and when the device node isn't opened through devfs.
969  */
970 
971 struct tty *
972 tty_alloc(struct ttydevsw *tsw, void *sc)
973 {
974 
975 	return (tty_alloc_mutex(tsw, sc, NULL));
976 }
977 
978 struct tty *
979 tty_alloc_mutex(struct ttydevsw *tsw, void *sc, struct mtx *mutex)
980 {
981 	struct tty *tp;
982 
983 	/* Make sure the driver defines all routines. */
984 #define PATCH_FUNC(x) do {				\
985 	if (tsw->tsw_ ## x == NULL)			\
986 		tsw->tsw_ ## x = ttydevsw_def ## x;	\
987 } while (0)
988 	PATCH_FUNC(open);
989 	PATCH_FUNC(close);
990 	PATCH_FUNC(outwakeup);
991 	PATCH_FUNC(inwakeup);
992 	PATCH_FUNC(ioctl);
993 	PATCH_FUNC(cioctl);
994 	PATCH_FUNC(param);
995 	PATCH_FUNC(modem);
996 	PATCH_FUNC(mmap);
997 	PATCH_FUNC(pktnotify);
998 	PATCH_FUNC(free);
999 	PATCH_FUNC(busy);
1000 #undef PATCH_FUNC
1001 
1002 	tp = malloc(sizeof(struct tty), M_TTY, M_WAITOK|M_ZERO);
1003 	tp->t_devsw = tsw;
1004 	tp->t_devswsoftc = sc;
1005 	tp->t_flags = tsw->tsw_flags;
1006 
1007 	tty_init_termios(tp);
1008 
1009 	cv_init(&tp->t_inwait, "ttyin");
1010 	cv_init(&tp->t_outwait, "ttyout");
1011 	cv_init(&tp->t_outserwait, "ttyosr");
1012 	cv_init(&tp->t_bgwait, "ttybg");
1013 	cv_init(&tp->t_dcdwait, "ttydcd");
1014 
1015 	/* Allow drivers to use a custom mutex to lock the TTY. */
1016 	if (mutex != NULL) {
1017 		tp->t_mtx = mutex;
1018 	} else {
1019 		tp->t_mtx = &tp->t_mtxobj;
1020 		mtx_init(&tp->t_mtxobj, "ttymtx", NULL, MTX_DEF);
1021 	}
1022 
1023 	knlist_init_mtx(&tp->t_inpoll.si_note, tp->t_mtx);
1024 	knlist_init_mtx(&tp->t_outpoll.si_note, tp->t_mtx);
1025 
1026 	return (tp);
1027 }
1028 
1029 static void
1030 tty_dealloc(void *arg)
1031 {
1032 	struct tty *tp = arg;
1033 
1034 	/*
1035 	 * ttyydev_leave() usually frees the i/o queues earlier, but it is
1036 	 * not always called between queue allocation and here.  The queues
1037 	 * may be allocated by ioctls on a pty control device without the
1038 	 * corresponding pty slave device ever being open, or after it is
1039 	 * closed.
1040 	 */
1041 	ttyinq_free(&tp->t_inq);
1042 	ttyoutq_free(&tp->t_outq);
1043 	seldrain(&tp->t_inpoll);
1044 	seldrain(&tp->t_outpoll);
1045 	knlist_destroy(&tp->t_inpoll.si_note);
1046 	knlist_destroy(&tp->t_outpoll.si_note);
1047 
1048 	cv_destroy(&tp->t_inwait);
1049 	cv_destroy(&tp->t_outwait);
1050 	cv_destroy(&tp->t_bgwait);
1051 	cv_destroy(&tp->t_dcdwait);
1052 	cv_destroy(&tp->t_outserwait);
1053 
1054 	if (tp->t_mtx == &tp->t_mtxobj)
1055 		mtx_destroy(&tp->t_mtxobj);
1056 	ttydevsw_free(tp);
1057 	free(tp, M_TTY);
1058 }
1059 
1060 static void
1061 tty_rel_free(struct tty *tp)
1062 {
1063 	struct cdev *dev;
1064 
1065 	tty_lock_assert(tp, MA_OWNED);
1066 
1067 #define	TF_ACTIVITY	(TF_GONE|TF_OPENED|TF_HOOK|TF_OPENCLOSE)
1068 	if (tp->t_sessioncnt != 0 || (tp->t_flags & TF_ACTIVITY) != TF_GONE) {
1069 		/* TTY is still in use. */
1070 		tty_unlock(tp);
1071 		return;
1072 	}
1073 
1074 	/* TTY can be deallocated. */
1075 	dev = tp->t_dev;
1076 	tp->t_dev = NULL;
1077 	tty_unlock(tp);
1078 
1079 	if (dev != NULL) {
1080 		sx_xlock(&tty_list_sx);
1081 		TAILQ_REMOVE(&tty_list, tp, t_list);
1082 		tty_list_count--;
1083 		sx_xunlock(&tty_list_sx);
1084 		destroy_dev_sched_cb(dev, tty_dealloc, tp);
1085 	}
1086 }
1087 
1088 void
1089 tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
1090 {
1091 	MPASS(tp->t_sessioncnt > 0);
1092 	tty_lock_assert(tp, MA_OWNED);
1093 
1094 	if (tp->t_pgrp == pg)
1095 		tp->t_pgrp = NULL;
1096 
1097 	tty_unlock(tp);
1098 }
1099 
1100 void
1101 tty_rel_sess(struct tty *tp, struct session *sess)
1102 {
1103 	MPASS(tp->t_sessioncnt > 0);
1104 
1105 	/* Current session has left. */
1106 	if (tp->t_session == sess) {
1107 		tp->t_session = NULL;
1108 		MPASS(tp->t_pgrp == NULL);
1109 	}
1110 	tp->t_sessioncnt--;
1111 	tty_rel_free(tp);
1112 }
1113 
1114 void
1115 tty_rel_gone(struct tty *tp)
1116 {
1117 	MPASS(!tty_gone(tp));
1118 
1119 	/* Simulate carrier removal. */
1120 	ttydisc_modem(tp, 0);
1121 
1122 	/* Wake up all blocked threads. */
1123 	tty_wakeup(tp, FREAD|FWRITE);
1124 	cv_broadcast(&tp->t_bgwait);
1125 	cv_broadcast(&tp->t_dcdwait);
1126 
1127 	tp->t_flags |= TF_GONE;
1128 	tty_rel_free(tp);
1129 }
1130 
1131 /*
1132  * Exposing information about current TTY's through sysctl
1133  */
1134 
1135 static void
1136 tty_to_xtty(struct tty *tp, struct xtty *xt)
1137 {
1138 	tty_lock_assert(tp, MA_OWNED);
1139 
1140 	xt->xt_size = sizeof(struct xtty);
1141 	xt->xt_insize = ttyinq_getsize(&tp->t_inq);
1142 	xt->xt_incc = ttyinq_bytescanonicalized(&tp->t_inq);
1143 	xt->xt_inlc = ttyinq_bytesline(&tp->t_inq);
1144 	xt->xt_inlow = tp->t_inlow;
1145 	xt->xt_outsize = ttyoutq_getsize(&tp->t_outq);
1146 	xt->xt_outcc = ttyoutq_bytesused(&tp->t_outq);
1147 	xt->xt_outlow = tp->t_outlow;
1148 	xt->xt_column = tp->t_column;
1149 	xt->xt_pgid = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
1150 	xt->xt_sid = tp->t_session ? tp->t_session->s_sid : 0;
1151 	xt->xt_flags = tp->t_flags;
1152 	xt->xt_dev = tp->t_dev ? dev2udev(tp->t_dev) : NODEV;
1153 }
1154 
1155 static int
1156 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
1157 {
1158 	unsigned long lsize;
1159 	struct xtty *xtlist, *xt;
1160 	struct tty *tp;
1161 	int error;
1162 
1163 	sx_slock(&tty_list_sx);
1164 	lsize = tty_list_count * sizeof(struct xtty);
1165 	if (lsize == 0) {
1166 		sx_sunlock(&tty_list_sx);
1167 		return (0);
1168 	}
1169 
1170 	xtlist = xt = malloc(lsize, M_TTY, M_WAITOK);
1171 
1172 	TAILQ_FOREACH(tp, &tty_list, t_list) {
1173 		tty_lock(tp);
1174 		tty_to_xtty(tp, xt);
1175 		tty_unlock(tp);
1176 		xt++;
1177 	}
1178 	sx_sunlock(&tty_list_sx);
1179 
1180 	error = SYSCTL_OUT(req, xtlist, lsize);
1181 	free(xtlist, M_TTY);
1182 	return (error);
1183 }
1184 
1185 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
1186 	0, 0, sysctl_kern_ttys, "S,xtty", "List of TTYs");
1187 
1188 /*
1189  * Device node creation. Device has been set up, now we can expose it to
1190  * the user.
1191  */
1192 
1193 int
1194 tty_makedevf(struct tty *tp, struct ucred *cred, int flags,
1195     const char *fmt, ...)
1196 {
1197 	va_list ap;
1198 	struct make_dev_args args;
1199 	struct cdev *dev, *init, *lock, *cua, *cinit, *clock;
1200 	const char *prefix = "tty";
1201 	char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
1202 	uid_t uid;
1203 	gid_t gid;
1204 	mode_t mode;
1205 	int error;
1206 
1207 	/* Remove "tty" prefix from devices like PTY's. */
1208 	if (tp->t_flags & TF_NOPREFIX)
1209 		prefix = "";
1210 
1211 	va_start(ap, fmt);
1212 	vsnrprintf(name, sizeof name, 32, fmt, ap);
1213 	va_end(ap);
1214 
1215 	if (cred == NULL) {
1216 		/* System device. */
1217 		uid = UID_ROOT;
1218 		gid = GID_WHEEL;
1219 		mode = S_IRUSR|S_IWUSR;
1220 	} else {
1221 		/* User device. */
1222 		uid = cred->cr_ruid;
1223 		gid = GID_TTY;
1224 		mode = S_IRUSR|S_IWUSR|S_IWGRP;
1225 	}
1226 
1227 	flags = flags & TTYMK_CLONING ? MAKEDEV_REF : 0;
1228 	flags |= MAKEDEV_CHECKNAME;
1229 
1230 	/* Master call-in device. */
1231 	make_dev_args_init(&args);
1232 	args.mda_flags = flags;
1233 	args.mda_devsw = &ttydev_cdevsw;
1234 	args.mda_cr = cred;
1235 	args.mda_uid = uid;
1236 	args.mda_gid = gid;
1237 	args.mda_mode = mode;
1238 	args.mda_si_drv1 = tp;
1239 	error = make_dev_s(&args, &dev, "%s%s", prefix, name);
1240 	if (error != 0)
1241 		return (error);
1242 	tp->t_dev = dev;
1243 
1244 	init = lock = cua = cinit = clock = NULL;
1245 
1246 	/* Slave call-in devices. */
1247 	if (tp->t_flags & TF_INITLOCK) {
1248 		args.mda_devsw = &ttyil_cdevsw;
1249 		args.mda_unit = TTYUNIT_INIT;
1250 		args.mda_si_drv1 = tp;
1251 		args.mda_si_drv2 = &tp->t_termios_init_in;
1252 		error = make_dev_s(&args, &init, "%s%s.init", prefix, name);
1253 		if (error != 0)
1254 			goto fail;
1255 		dev_depends(dev, init);
1256 
1257 		args.mda_unit = TTYUNIT_LOCK;
1258 		args.mda_si_drv2 = &tp->t_termios_lock_in;
1259 		error = make_dev_s(&args, &lock, "%s%s.lock", prefix, name);
1260 		if (error != 0)
1261 			goto fail;
1262 		dev_depends(dev, lock);
1263 	}
1264 
1265 	/* Call-out devices. */
1266 	if (tp->t_flags & TF_CALLOUT) {
1267 		make_dev_args_init(&args);
1268 		args.mda_flags = flags;
1269 		args.mda_devsw = &ttydev_cdevsw;
1270 		args.mda_cr = cred;
1271 		args.mda_uid = UID_UUCP;
1272 		args.mda_gid = GID_DIALER;
1273 		args.mda_mode = 0660;
1274 		args.mda_unit = TTYUNIT_CALLOUT;
1275 		args.mda_si_drv1 = tp;
1276 		error = make_dev_s(&args, &cua, "cua%s", name);
1277 		if (error != 0)
1278 			goto fail;
1279 		dev_depends(dev, cua);
1280 
1281 		/* Slave call-out devices. */
1282 		if (tp->t_flags & TF_INITLOCK) {
1283 			args.mda_devsw = &ttyil_cdevsw;
1284 			args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_INIT;
1285 			args.mda_si_drv2 = &tp->t_termios_init_out;
1286 			error = make_dev_s(&args, &cinit, "cua%s.init", name);
1287 			if (error != 0)
1288 				goto fail;
1289 			dev_depends(dev, cinit);
1290 
1291 			args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_LOCK;
1292 			args.mda_si_drv2 = &tp->t_termios_lock_out;
1293 			error = make_dev_s(&args, &clock, "cua%s.lock", name);
1294 			if (error != 0)
1295 				goto fail;
1296 			dev_depends(dev, clock);
1297 		}
1298 	}
1299 
1300 	sx_xlock(&tty_list_sx);
1301 	TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
1302 	tty_list_count++;
1303 	sx_xunlock(&tty_list_sx);
1304 
1305 	return (0);
1306 
1307 fail:
1308 	destroy_dev(dev);
1309 	if (init)
1310 		destroy_dev(init);
1311 	if (lock)
1312 		destroy_dev(lock);
1313 	if (cinit)
1314 		destroy_dev(cinit);
1315 	if (clock)
1316 		destroy_dev(clock);
1317 
1318 	return (error);
1319 }
1320 
1321 /*
1322  * Signalling processes.
1323  */
1324 
1325 void
1326 tty_signal_sessleader(struct tty *tp, int sig)
1327 {
1328 	struct proc *p;
1329 
1330 	tty_lock_assert(tp, MA_OWNED);
1331 	MPASS(sig >= 1 && sig < NSIG);
1332 
1333 	/* Make signals start output again. */
1334 	tp->t_flags &= ~TF_STOPPED;
1335 
1336 	if (tp->t_session != NULL && tp->t_session->s_leader != NULL) {
1337 		p = tp->t_session->s_leader;
1338 		PROC_LOCK(p);
1339 		kern_psignal(p, sig);
1340 		PROC_UNLOCK(p);
1341 	}
1342 }
1343 
1344 void
1345 tty_signal_pgrp(struct tty *tp, int sig)
1346 {
1347 	ksiginfo_t ksi;
1348 
1349 	tty_lock_assert(tp, MA_OWNED);
1350 	MPASS(sig >= 1 && sig < NSIG);
1351 
1352 	/* Make signals start output again. */
1353 	tp->t_flags &= ~TF_STOPPED;
1354 
1355 	if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
1356 		tty_info(tp);
1357 	if (tp->t_pgrp != NULL) {
1358 		ksiginfo_init(&ksi);
1359 		ksi.ksi_signo = sig;
1360 		ksi.ksi_code = SI_KERNEL;
1361 		PGRP_LOCK(tp->t_pgrp);
1362 		pgsignal(tp->t_pgrp, sig, 1, &ksi);
1363 		PGRP_UNLOCK(tp->t_pgrp);
1364 	}
1365 }
1366 
1367 void
1368 tty_wakeup(struct tty *tp, int flags)
1369 {
1370 	if (tp->t_flags & TF_ASYNC && tp->t_sigio != NULL)
1371 		pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
1372 
1373 	if (flags & FWRITE) {
1374 		cv_broadcast(&tp->t_outwait);
1375 		selwakeup(&tp->t_outpoll);
1376 		KNOTE_LOCKED(&tp->t_outpoll.si_note, 0);
1377 	}
1378 	if (flags & FREAD) {
1379 		cv_broadcast(&tp->t_inwait);
1380 		selwakeup(&tp->t_inpoll);
1381 		KNOTE_LOCKED(&tp->t_inpoll.si_note, 0);
1382 	}
1383 }
1384 
1385 int
1386 tty_wait(struct tty *tp, struct cv *cv)
1387 {
1388 	int error;
1389 	int revokecnt = tp->t_revokecnt;
1390 
1391 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1392 	MPASS(!tty_gone(tp));
1393 
1394 	error = cv_wait_sig(cv, tp->t_mtx);
1395 
1396 	/* Bail out when the device slipped away. */
1397 	if (tty_gone(tp))
1398 		return (ENXIO);
1399 
1400 	/* Restart the system call when we may have been revoked. */
1401 	if (tp->t_revokecnt != revokecnt)
1402 		return (ERESTART);
1403 
1404 	return (error);
1405 }
1406 
1407 int
1408 tty_timedwait(struct tty *tp, struct cv *cv, int hz)
1409 {
1410 	int error;
1411 	int revokecnt = tp->t_revokecnt;
1412 
1413 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1414 	MPASS(!tty_gone(tp));
1415 
1416 	error = cv_timedwait_sig(cv, tp->t_mtx, hz);
1417 
1418 	/* Bail out when the device slipped away. */
1419 	if (tty_gone(tp))
1420 		return (ENXIO);
1421 
1422 	/* Restart the system call when we may have been revoked. */
1423 	if (tp->t_revokecnt != revokecnt)
1424 		return (ERESTART);
1425 
1426 	return (error);
1427 }
1428 
1429 void
1430 tty_flush(struct tty *tp, int flags)
1431 {
1432 	if (flags & FWRITE) {
1433 		tp->t_flags &= ~TF_HIWAT_OUT;
1434 		ttyoutq_flush(&tp->t_outq);
1435 		tty_wakeup(tp, FWRITE);
1436 		ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
1437 	}
1438 	if (flags & FREAD) {
1439 		tty_hiwat_in_unblock(tp);
1440 		ttyinq_flush(&tp->t_inq);
1441 		ttydevsw_inwakeup(tp);
1442 		ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
1443 	}
1444 }
1445 
1446 void
1447 tty_set_winsize(struct tty *tp, const struct winsize *wsz)
1448 {
1449 
1450 	if (memcmp(&tp->t_winsize, wsz, sizeof(*wsz)) == 0)
1451 		return;
1452 	tp->t_winsize = *wsz;
1453 	tty_signal_pgrp(tp, SIGWINCH);
1454 }
1455 
1456 static int
1457 tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, int fflag,
1458     struct thread *td)
1459 {
1460 	int error;
1461 
1462 	switch (cmd) {
1463 	/*
1464 	 * Modem commands.
1465 	 * The SER_* and TIOCM_* flags are the same, but one bit
1466 	 * shifted. I don't know why.
1467 	 */
1468 	case TIOCSDTR:
1469 		ttydevsw_modem(tp, SER_DTR, 0);
1470 		return (0);
1471 	case TIOCCDTR:
1472 		ttydevsw_modem(tp, 0, SER_DTR);
1473 		return (0);
1474 	case TIOCMSET: {
1475 		int bits = *(int *)data;
1476 		ttydevsw_modem(tp,
1477 		    (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1,
1478 		    ((~bits) & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1479 		return (0);
1480 	}
1481 	case TIOCMBIS: {
1482 		int bits = *(int *)data;
1483 		ttydevsw_modem(tp, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1, 0);
1484 		return (0);
1485 	}
1486 	case TIOCMBIC: {
1487 		int bits = *(int *)data;
1488 		ttydevsw_modem(tp, 0, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1489 		return (0);
1490 	}
1491 	case TIOCMGET:
1492 		*(int *)data = TIOCM_LE + (ttydevsw_modem(tp, 0, 0) << 1);
1493 		return (0);
1494 
1495 	case FIOASYNC:
1496 		if (*(int *)data)
1497 			tp->t_flags |= TF_ASYNC;
1498 		else
1499 			tp->t_flags &= ~TF_ASYNC;
1500 		return (0);
1501 	case FIONBIO:
1502 		/* This device supports non-blocking operation. */
1503 		return (0);
1504 	case FIONREAD:
1505 		*(int *)data = ttyinq_bytescanonicalized(&tp->t_inq);
1506 		return (0);
1507 	case FIONWRITE:
1508 	case TIOCOUTQ:
1509 		*(int *)data = ttyoutq_bytesused(&tp->t_outq);
1510 		return (0);
1511 	case FIOSETOWN:
1512 		if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1513 			/* Not allowed to set ownership. */
1514 			return (ENOTTY);
1515 
1516 		/* Temporarily unlock the TTY to set ownership. */
1517 		tty_unlock(tp);
1518 		error = fsetown(*(int *)data, &tp->t_sigio);
1519 		tty_lock(tp);
1520 		return (error);
1521 	case FIOGETOWN:
1522 		if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1523 			/* Not allowed to set ownership. */
1524 			return (ENOTTY);
1525 
1526 		/* Get ownership. */
1527 		*(int *)data = fgetown(&tp->t_sigio);
1528 		return (0);
1529 	case TIOCGETA:
1530 		/* Obtain terminal flags through tcgetattr(). */
1531 		*(struct termios*)data = tp->t_termios;
1532 		return (0);
1533 	case TIOCSETA:
1534 	case TIOCSETAW:
1535 	case TIOCSETAF: {
1536 		struct termios *t = data;
1537 
1538 		/*
1539 		 * Who makes up these funny rules? According to POSIX,
1540 		 * input baud rate is set equal to the output baud rate
1541 		 * when zero.
1542 		 */
1543 		if (t->c_ispeed == 0)
1544 			t->c_ispeed = t->c_ospeed;
1545 
1546 		/* Discard any unsupported bits. */
1547 		t->c_iflag &= TTYSUP_IFLAG;
1548 		t->c_oflag &= TTYSUP_OFLAG;
1549 		t->c_lflag &= TTYSUP_LFLAG;
1550 		t->c_cflag &= TTYSUP_CFLAG;
1551 
1552 		/* Set terminal flags through tcsetattr(). */
1553 		if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
1554 			error = tty_drain(tp, 0);
1555 			if (error)
1556 				return (error);
1557 			if (cmd == TIOCSETAF)
1558 				tty_flush(tp, FREAD);
1559 		}
1560 
1561 		/*
1562 		 * Only call param() when the flags really change.
1563 		 */
1564 		if ((t->c_cflag & CIGNORE) == 0 &&
1565 		    (tp->t_termios.c_cflag != t->c_cflag ||
1566 		    ((tp->t_termios.c_iflag ^ t->c_iflag) &
1567 		    (IXON|IXOFF|IXANY)) ||
1568 		    tp->t_termios.c_ispeed != t->c_ispeed ||
1569 		    tp->t_termios.c_ospeed != t->c_ospeed)) {
1570 			error = ttydevsw_param(tp, t);
1571 			if (error)
1572 				return (error);
1573 
1574 			/* XXX: CLOCAL? */
1575 
1576 			tp->t_termios.c_cflag = t->c_cflag & ~CIGNORE;
1577 			tp->t_termios.c_ispeed = t->c_ispeed;
1578 			tp->t_termios.c_ospeed = t->c_ospeed;
1579 
1580 			/* Baud rate has changed - update watermarks. */
1581 			tty_watermarks(tp);
1582 		}
1583 
1584 		/* Copy new non-device driver parameters. */
1585 		tp->t_termios.c_iflag = t->c_iflag;
1586 		tp->t_termios.c_oflag = t->c_oflag;
1587 		tp->t_termios.c_lflag = t->c_lflag;
1588 		memcpy(&tp->t_termios.c_cc, t->c_cc, sizeof t->c_cc);
1589 
1590 		ttydisc_optimize(tp);
1591 
1592 		if ((t->c_lflag & ICANON) == 0) {
1593 			/*
1594 			 * When in non-canonical mode, wake up all
1595 			 * readers. Canonicalize any partial input. VMIN
1596 			 * and VTIME could also be adjusted.
1597 			 */
1598 			ttyinq_canonicalize(&tp->t_inq);
1599 			tty_wakeup(tp, FREAD);
1600 		}
1601 
1602 		/*
1603 		 * For packet mode: notify the PTY consumer that VSTOP
1604 		 * and VSTART may have been changed.
1605 		 */
1606 		if (tp->t_termios.c_iflag & IXON &&
1607 		    tp->t_termios.c_cc[VSTOP] == CTRL('S') &&
1608 		    tp->t_termios.c_cc[VSTART] == CTRL('Q'))
1609 			ttydevsw_pktnotify(tp, TIOCPKT_DOSTOP);
1610 		else
1611 			ttydevsw_pktnotify(tp, TIOCPKT_NOSTOP);
1612 		return (0);
1613 	}
1614 	case TIOCGETD:
1615 		/* For compatibility - we only support TTYDISC. */
1616 		*(int *)data = TTYDISC;
1617 		return (0);
1618 	case TIOCGPGRP:
1619 		if (!tty_is_ctty(tp, td->td_proc))
1620 			return (ENOTTY);
1621 
1622 		if (tp->t_pgrp != NULL)
1623 			*(int *)data = tp->t_pgrp->pg_id;
1624 		else
1625 			*(int *)data = NO_PID;
1626 		return (0);
1627 	case TIOCGSID:
1628 		if (!tty_is_ctty(tp, td->td_proc))
1629 			return (ENOTTY);
1630 
1631 		MPASS(tp->t_session);
1632 		*(int *)data = tp->t_session->s_sid;
1633 		return (0);
1634 	case TIOCSCTTY: {
1635 		struct proc *p = td->td_proc;
1636 
1637 		/* XXX: This looks awful. */
1638 		tty_unlock(tp);
1639 		sx_xlock(&proctree_lock);
1640 		tty_lock(tp);
1641 
1642 		if (!SESS_LEADER(p)) {
1643 			/* Only the session leader may do this. */
1644 			sx_xunlock(&proctree_lock);
1645 			return (EPERM);
1646 		}
1647 
1648 		if (tp->t_session != NULL && tp->t_session == p->p_session) {
1649 			/* This is already our controlling TTY. */
1650 			sx_xunlock(&proctree_lock);
1651 			return (0);
1652 		}
1653 
1654 		if (p->p_session->s_ttyp != NULL ||
1655 		    (tp->t_session != NULL && tp->t_session->s_ttyvp != NULL &&
1656 		    tp->t_session->s_ttyvp->v_type != VBAD)) {
1657 			/*
1658 			 * There is already a relation between a TTY and
1659 			 * a session, or the caller is not the session
1660 			 * leader.
1661 			 *
1662 			 * Allow the TTY to be stolen when the vnode is
1663 			 * invalid, but the reference to the TTY is
1664 			 * still active.  This allows immediate reuse of
1665 			 * TTYs of which the session leader has been
1666 			 * killed or the TTY revoked.
1667 			 */
1668 			sx_xunlock(&proctree_lock);
1669 			return (EPERM);
1670 		}
1671 
1672 		/* Connect the session to the TTY. */
1673 		tp->t_session = p->p_session;
1674 		tp->t_session->s_ttyp = tp;
1675 		tp->t_sessioncnt++;
1676 		sx_xunlock(&proctree_lock);
1677 
1678 		/* Assign foreground process group. */
1679 		tp->t_pgrp = p->p_pgrp;
1680 		PROC_LOCK(p);
1681 		p->p_flag |= P_CONTROLT;
1682 		PROC_UNLOCK(p);
1683 
1684 		return (0);
1685 	}
1686 	case TIOCSPGRP: {
1687 		struct pgrp *pg;
1688 
1689 		/*
1690 		 * XXX: Temporarily unlock the TTY to locate the process
1691 		 * group. This code would be lot nicer if we would ever
1692 		 * decompose proctree_lock.
1693 		 */
1694 		tty_unlock(tp);
1695 		sx_slock(&proctree_lock);
1696 		pg = pgfind(*(int *)data);
1697 		if (pg != NULL)
1698 			PGRP_UNLOCK(pg);
1699 		if (pg == NULL || pg->pg_session != td->td_proc->p_session) {
1700 			sx_sunlock(&proctree_lock);
1701 			tty_lock(tp);
1702 			return (EPERM);
1703 		}
1704 		tty_lock(tp);
1705 
1706 		/*
1707 		 * Determine if this TTY is the controlling TTY after
1708 		 * relocking the TTY.
1709 		 */
1710 		if (!tty_is_ctty(tp, td->td_proc)) {
1711 			sx_sunlock(&proctree_lock);
1712 			return (ENOTTY);
1713 		}
1714 		tp->t_pgrp = pg;
1715 		sx_sunlock(&proctree_lock);
1716 
1717 		/* Wake up the background process groups. */
1718 		cv_broadcast(&tp->t_bgwait);
1719 		return (0);
1720 	}
1721 	case TIOCFLUSH: {
1722 		int flags = *(int *)data;
1723 
1724 		if (flags == 0)
1725 			flags = (FREAD|FWRITE);
1726 		else
1727 			flags &= (FREAD|FWRITE);
1728 		tty_flush(tp, flags);
1729 		return (0);
1730 	}
1731 	case TIOCDRAIN:
1732 		/* Drain TTY output. */
1733 		return tty_drain(tp, 0);
1734 	case TIOCCONS:
1735 		/* Set terminal as console TTY. */
1736 		if (*(int *)data) {
1737 			error = priv_check(td, PRIV_TTY_CONSOLE);
1738 			if (error)
1739 				return (error);
1740 
1741 			/*
1742 			 * XXX: constty should really need to be locked!
1743 			 * XXX: allow disconnected constty's to be stolen!
1744 			 */
1745 
1746 			if (constty == tp)
1747 				return (0);
1748 			if (constty != NULL)
1749 				return (EBUSY);
1750 
1751 			tty_unlock(tp);
1752 			constty_set(tp);
1753 			tty_lock(tp);
1754 		} else if (constty == tp) {
1755 			constty_clear();
1756 		}
1757 		return (0);
1758 	case TIOCGWINSZ:
1759 		/* Obtain window size. */
1760 		*(struct winsize*)data = tp->t_winsize;
1761 		return (0);
1762 	case TIOCSWINSZ:
1763 		/* Set window size. */
1764 		tty_set_winsize(tp, data);
1765 		return (0);
1766 	case TIOCEXCL:
1767 		tp->t_flags |= TF_EXCLUDE;
1768 		return (0);
1769 	case TIOCNXCL:
1770 		tp->t_flags &= ~TF_EXCLUDE;
1771 		return (0);
1772 	case TIOCSTOP:
1773 		tp->t_flags |= TF_STOPPED;
1774 		ttydevsw_pktnotify(tp, TIOCPKT_STOP);
1775 		return (0);
1776 	case TIOCSTART:
1777 		tp->t_flags &= ~TF_STOPPED;
1778 		ttydevsw_outwakeup(tp);
1779 		ttydevsw_pktnotify(tp, TIOCPKT_START);
1780 		return (0);
1781 	case TIOCSTAT:
1782 		tty_info(tp);
1783 		return (0);
1784 	case TIOCSTI:
1785 		if ((fflag & FREAD) == 0 && priv_check(td, PRIV_TTY_STI))
1786 			return (EPERM);
1787 		if (!tty_is_ctty(tp, td->td_proc) &&
1788 		    priv_check(td, PRIV_TTY_STI))
1789 			return (EACCES);
1790 		ttydisc_rint(tp, *(char *)data, 0);
1791 		ttydisc_rint_done(tp);
1792 		return (0);
1793 	}
1794 
1795 #ifdef COMPAT_43TTY
1796 	return tty_ioctl_compat(tp, cmd, data, fflag, td);
1797 #else /* !COMPAT_43TTY */
1798 	return (ENOIOCTL);
1799 #endif /* COMPAT_43TTY */
1800 }
1801 
1802 int
1803 tty_ioctl(struct tty *tp, u_long cmd, void *data, int fflag, struct thread *td)
1804 {
1805 	int error;
1806 
1807 	tty_lock_assert(tp, MA_OWNED);
1808 
1809 	if (tty_gone(tp))
1810 		return (ENXIO);
1811 
1812 	error = ttydevsw_ioctl(tp, cmd, data, td);
1813 	if (error == ENOIOCTL)
1814 		error = tty_generic_ioctl(tp, cmd, data, fflag, td);
1815 
1816 	return (error);
1817 }
1818 
1819 dev_t
1820 tty_udev(struct tty *tp)
1821 {
1822 	if (tp->t_dev)
1823 		return dev2udev(tp->t_dev);
1824 	else
1825 		return NODEV;
1826 }
1827 
1828 int
1829 tty_checkoutq(struct tty *tp)
1830 {
1831 
1832 	/* 256 bytes should be enough to print a log message. */
1833 	return (ttyoutq_bytesleft(&tp->t_outq) >= 256);
1834 }
1835 
1836 void
1837 tty_hiwat_in_block(struct tty *tp)
1838 {
1839 
1840 	if ((tp->t_flags & TF_HIWAT_IN) == 0 &&
1841 	    tp->t_termios.c_iflag & IXOFF &&
1842 	    tp->t_termios.c_cc[VSTOP] != _POSIX_VDISABLE) {
1843 		/*
1844 		 * Input flow control. Only enter the high watermark when we
1845 		 * can successfully store the VSTOP character.
1846 		 */
1847 		if (ttyoutq_write_nofrag(&tp->t_outq,
1848 		    &tp->t_termios.c_cc[VSTOP], 1) == 0)
1849 			tp->t_flags |= TF_HIWAT_IN;
1850 	} else {
1851 		/* No input flow control. */
1852 		tp->t_flags |= TF_HIWAT_IN;
1853 	}
1854 }
1855 
1856 void
1857 tty_hiwat_in_unblock(struct tty *tp)
1858 {
1859 
1860 	if (tp->t_flags & TF_HIWAT_IN &&
1861 	    tp->t_termios.c_iflag & IXOFF &&
1862 	    tp->t_termios.c_cc[VSTART] != _POSIX_VDISABLE) {
1863 		/*
1864 		 * Input flow control. Only leave the high watermark when we
1865 		 * can successfully store the VSTART character.
1866 		 */
1867 		if (ttyoutq_write_nofrag(&tp->t_outq,
1868 		    &tp->t_termios.c_cc[VSTART], 1) == 0)
1869 			tp->t_flags &= ~TF_HIWAT_IN;
1870 	} else {
1871 		/* No input flow control. */
1872 		tp->t_flags &= ~TF_HIWAT_IN;
1873 	}
1874 
1875 	if (!tty_gone(tp))
1876 		ttydevsw_inwakeup(tp);
1877 }
1878 
1879 /*
1880  * TTY hooks interface.
1881  */
1882 
1883 static int
1884 ttyhook_defrint(struct tty *tp, char c, int flags)
1885 {
1886 
1887 	if (ttyhook_rint_bypass(tp, &c, 1) != 1)
1888 		return (-1);
1889 
1890 	return (0);
1891 }
1892 
1893 int
1894 ttyhook_register(struct tty **rtp, struct proc *p, int fd,
1895     struct ttyhook *th, void *softc)
1896 {
1897 	struct tty *tp;
1898 	struct file *fp;
1899 	struct cdev *dev;
1900 	struct cdevsw *cdp;
1901 	struct filedesc *fdp;
1902 	cap_rights_t rights;
1903 	int error, ref;
1904 
1905 	/* Validate the file descriptor. */
1906 	fdp = p->p_fd;
1907 	error = fget_unlocked(fdp, fd, cap_rights_init(&rights, CAP_TTYHOOK),
1908 	    &fp, NULL);
1909 	if (error != 0)
1910 		return (error);
1911 	if (fp->f_ops == &badfileops) {
1912 		error = EBADF;
1913 		goto done1;
1914 	}
1915 
1916 	/*
1917 	 * Make sure the vnode is bound to a character device.
1918 	 * Unlocked check for the vnode type is ok there, because we
1919 	 * only shall prevent calling devvn_refthread on the file that
1920 	 * never has been opened over a character device.
1921 	 */
1922 	if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR) {
1923 		error = EINVAL;
1924 		goto done1;
1925 	}
1926 
1927 	/* Make sure it is a TTY. */
1928 	cdp = devvn_refthread(fp->f_vnode, &dev, &ref);
1929 	if (cdp == NULL) {
1930 		error = ENXIO;
1931 		goto done1;
1932 	}
1933 	if (dev != fp->f_data) {
1934 		error = ENXIO;
1935 		goto done2;
1936 	}
1937 	if (cdp != &ttydev_cdevsw) {
1938 		error = ENOTTY;
1939 		goto done2;
1940 	}
1941 	tp = dev->si_drv1;
1942 
1943 	/* Try to attach the hook to the TTY. */
1944 	error = EBUSY;
1945 	tty_lock(tp);
1946 	MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
1947 	if (tp->t_flags & TF_HOOK)
1948 		goto done3;
1949 
1950 	tp->t_flags |= TF_HOOK;
1951 	tp->t_hook = th;
1952 	tp->t_hooksoftc = softc;
1953 	*rtp = tp;
1954 	error = 0;
1955 
1956 	/* Maybe we can switch into bypass mode now. */
1957 	ttydisc_optimize(tp);
1958 
1959 	/* Silently convert rint() calls to rint_bypass() when possible. */
1960 	if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
1961 		th->th_rint = ttyhook_defrint;
1962 
1963 done3:	tty_unlock(tp);
1964 done2:	dev_relthread(dev, ref);
1965 done1:	fdrop(fp, curthread);
1966 	return (error);
1967 }
1968 
1969 void
1970 ttyhook_unregister(struct tty *tp)
1971 {
1972 
1973 	tty_lock_assert(tp, MA_OWNED);
1974 	MPASS(tp->t_flags & TF_HOOK);
1975 
1976 	/* Disconnect the hook. */
1977 	tp->t_flags &= ~TF_HOOK;
1978 	tp->t_hook = NULL;
1979 
1980 	/* Maybe we need to leave bypass mode. */
1981 	ttydisc_optimize(tp);
1982 
1983 	/* Maybe deallocate the TTY as well. */
1984 	tty_rel_free(tp);
1985 }
1986 
1987 /*
1988  * /dev/console handling.
1989  */
1990 
1991 static int
1992 ttyconsdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
1993 {
1994 	struct tty *tp;
1995 
1996 	/* System has no console device. */
1997 	if (dev_console_filename == NULL)
1998 		return (ENXIO);
1999 
2000 	/* Look up corresponding TTY by device name. */
2001 	sx_slock(&tty_list_sx);
2002 	TAILQ_FOREACH(tp, &tty_list, t_list) {
2003 		if (strcmp(dev_console_filename, tty_devname(tp)) == 0) {
2004 			dev_console->si_drv1 = tp;
2005 			break;
2006 		}
2007 	}
2008 	sx_sunlock(&tty_list_sx);
2009 
2010 	/* System console has no TTY associated. */
2011 	if (dev_console->si_drv1 == NULL)
2012 		return (ENXIO);
2013 
2014 	return (ttydev_open(dev, oflags, devtype, td));
2015 }
2016 
2017 static int
2018 ttyconsdev_write(struct cdev *dev, struct uio *uio, int ioflag)
2019 {
2020 
2021 	log_console(uio);
2022 
2023 	return (ttydev_write(dev, uio, ioflag));
2024 }
2025 
2026 /*
2027  * /dev/console is a little different than normal TTY's.  When opened,
2028  * it determines which TTY to use.  When data gets written to it, it
2029  * will be logged in the kernel message buffer.
2030  */
2031 static struct cdevsw ttyconsdev_cdevsw = {
2032 	.d_version	= D_VERSION,
2033 	.d_open		= ttyconsdev_open,
2034 	.d_close	= ttydev_close,
2035 	.d_read		= ttydev_read,
2036 	.d_write	= ttyconsdev_write,
2037 	.d_ioctl	= ttydev_ioctl,
2038 	.d_kqfilter	= ttydev_kqfilter,
2039 	.d_poll		= ttydev_poll,
2040 	.d_mmap		= ttydev_mmap,
2041 	.d_name		= "ttyconsdev",
2042 	.d_flags	= D_TTY,
2043 };
2044 
2045 static void
2046 ttyconsdev_init(void *unused)
2047 {
2048 
2049 	dev_console = make_dev_credf(MAKEDEV_ETERNAL, &ttyconsdev_cdevsw, 0,
2050 	    NULL, UID_ROOT, GID_WHEEL, 0600, "console");
2051 }
2052 
2053 SYSINIT(tty, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyconsdev_init, NULL);
2054 
2055 void
2056 ttyconsdev_select(const char *name)
2057 {
2058 
2059 	dev_console_filename = name;
2060 }
2061 
2062 /*
2063  * Debugging routines.
2064  */
2065 
2066 #include "opt_ddb.h"
2067 #ifdef DDB
2068 #include <ddb/ddb.h>
2069 #include <ddb/db_sym.h>
2070 
2071 static struct {
2072 	int flag;
2073 	char val;
2074 } ttystates[] = {
2075 #if 0
2076 	{ TF_NOPREFIX,		'N' },
2077 #endif
2078 	{ TF_INITLOCK,		'I' },
2079 	{ TF_CALLOUT,		'C' },
2080 
2081 	/* Keep these together -> 'Oi' and 'Oo'. */
2082 	{ TF_OPENED,		'O' },
2083 	{ TF_OPENED_IN,		'i' },
2084 	{ TF_OPENED_OUT,	'o' },
2085 	{ TF_OPENED_CONS,	'c' },
2086 
2087 	{ TF_GONE,		'G' },
2088 	{ TF_OPENCLOSE,		'B' },
2089 	{ TF_ASYNC,		'Y' },
2090 	{ TF_LITERAL,		'L' },
2091 
2092 	/* Keep these together -> 'Hi' and 'Ho'. */
2093 	{ TF_HIWAT,		'H' },
2094 	{ TF_HIWAT_IN,		'i' },
2095 	{ TF_HIWAT_OUT,		'o' },
2096 
2097 	{ TF_STOPPED,		'S' },
2098 	{ TF_EXCLUDE,		'X' },
2099 	{ TF_BYPASS,		'l' },
2100 	{ TF_ZOMBIE,		'Z' },
2101 	{ TF_HOOK,		's' },
2102 
2103 	/* Keep these together -> 'bi' and 'bo'. */
2104 	{ TF_BUSY,		'b' },
2105 	{ TF_BUSY_IN,		'i' },
2106 	{ TF_BUSY_OUT,		'o' },
2107 
2108 	{ 0,			'\0'},
2109 };
2110 
2111 #define	TTY_FLAG_BITS \
2112 	"\20\1NOPREFIX\2INITLOCK\3CALLOUT\4OPENED_IN\5OPENED_OUT\6GONE" \
2113 	"\7OPENCLOSE\10ASYNC\11LITERAL\12HIWAT_IN\13HIWAT_OUT\14STOPPED" \
2114 	"\15EXCLUDE\16BYPASS\17ZOMBIE\20HOOK"
2115 
2116 #define DB_PRINTSYM(name, addr) \
2117 	db_printf("%s  " #name ": ", sep); \
2118 	db_printsym((db_addr_t) addr, DB_STGY_ANY); \
2119 	db_printf("\n");
2120 
2121 static void
2122 _db_show_devsw(const char *sep, const struct ttydevsw *tsw)
2123 {
2124 	db_printf("%sdevsw: ", sep);
2125 	db_printsym((db_addr_t)tsw, DB_STGY_ANY);
2126 	db_printf(" (%p)\n", tsw);
2127 	DB_PRINTSYM(open, tsw->tsw_open);
2128 	DB_PRINTSYM(close, tsw->tsw_close);
2129 	DB_PRINTSYM(outwakeup, tsw->tsw_outwakeup);
2130 	DB_PRINTSYM(inwakeup, tsw->tsw_inwakeup);
2131 	DB_PRINTSYM(ioctl, tsw->tsw_ioctl);
2132 	DB_PRINTSYM(param, tsw->tsw_param);
2133 	DB_PRINTSYM(modem, tsw->tsw_modem);
2134 	DB_PRINTSYM(mmap, tsw->tsw_mmap);
2135 	DB_PRINTSYM(pktnotify, tsw->tsw_pktnotify);
2136 	DB_PRINTSYM(free, tsw->tsw_free);
2137 }
2138 static void
2139 _db_show_hooks(const char *sep, const struct ttyhook *th)
2140 {
2141 	db_printf("%shook: ", sep);
2142 	db_printsym((db_addr_t)th, DB_STGY_ANY);
2143 	db_printf(" (%p)\n", th);
2144 	if (th == NULL)
2145 		return;
2146 	DB_PRINTSYM(rint, th->th_rint);
2147 	DB_PRINTSYM(rint_bypass, th->th_rint_bypass);
2148 	DB_PRINTSYM(rint_done, th->th_rint_done);
2149 	DB_PRINTSYM(rint_poll, th->th_rint_poll);
2150 	DB_PRINTSYM(getc_inject, th->th_getc_inject);
2151 	DB_PRINTSYM(getc_capture, th->th_getc_capture);
2152 	DB_PRINTSYM(getc_poll, th->th_getc_poll);
2153 	DB_PRINTSYM(close, th->th_close);
2154 }
2155 
2156 static void
2157 _db_show_termios(const char *name, const struct termios *t)
2158 {
2159 
2160 	db_printf("%s: iflag 0x%x oflag 0x%x cflag 0x%x "
2161 	    "lflag 0x%x ispeed %u ospeed %u\n", name,
2162 	    t->c_iflag, t->c_oflag, t->c_cflag, t->c_lflag,
2163 	    t->c_ispeed, t->c_ospeed);
2164 }
2165 
2166 /* DDB command to show TTY statistics. */
2167 DB_SHOW_COMMAND(tty, db_show_tty)
2168 {
2169 	struct tty *tp;
2170 
2171 	if (!have_addr) {
2172 		db_printf("usage: show tty <addr>\n");
2173 		return;
2174 	}
2175 	tp = (struct tty *)addr;
2176 
2177 	db_printf("0x%p: %s\n", tp, tty_devname(tp));
2178 	db_printf("\tmtx: %p\n", tp->t_mtx);
2179 	db_printf("\tflags: %b\n", tp->t_flags, TTY_FLAG_BITS);
2180 	db_printf("\trevokecnt: %u\n", tp->t_revokecnt);
2181 
2182 	/* Buffering mechanisms. */
2183 	db_printf("\tinq: %p begin %u linestart %u reprint %u end %u "
2184 	    "nblocks %u quota %u\n", &tp->t_inq, tp->t_inq.ti_begin,
2185 	    tp->t_inq.ti_linestart, tp->t_inq.ti_reprint, tp->t_inq.ti_end,
2186 	    tp->t_inq.ti_nblocks, tp->t_inq.ti_quota);
2187 	db_printf("\toutq: %p begin %u end %u nblocks %u quota %u\n",
2188 	    &tp->t_outq, tp->t_outq.to_begin, tp->t_outq.to_end,
2189 	    tp->t_outq.to_nblocks, tp->t_outq.to_quota);
2190 	db_printf("\tinlow: %zu\n", tp->t_inlow);
2191 	db_printf("\toutlow: %zu\n", tp->t_outlow);
2192 	_db_show_termios("\ttermios", &tp->t_termios);
2193 	db_printf("\twinsize: row %u col %u xpixel %u ypixel %u\n",
2194 	    tp->t_winsize.ws_row, tp->t_winsize.ws_col,
2195 	    tp->t_winsize.ws_xpixel, tp->t_winsize.ws_ypixel);
2196 	db_printf("\tcolumn: %u\n", tp->t_column);
2197 	db_printf("\twritepos: %u\n", tp->t_writepos);
2198 	db_printf("\tcompatflags: 0x%x\n", tp->t_compatflags);
2199 
2200 	/* Init/lock-state devices. */
2201 	_db_show_termios("\ttermios_init_in", &tp->t_termios_init_in);
2202 	_db_show_termios("\ttermios_init_out", &tp->t_termios_init_out);
2203 	_db_show_termios("\ttermios_lock_in", &tp->t_termios_lock_in);
2204 	_db_show_termios("\ttermios_lock_out", &tp->t_termios_lock_out);
2205 
2206 	/* Hooks */
2207 	_db_show_devsw("\t", tp->t_devsw);
2208 	_db_show_hooks("\t", tp->t_hook);
2209 
2210 	/* Process info. */
2211 	db_printf("\tpgrp: %p gid %d jobc %d\n", tp->t_pgrp,
2212 	    tp->t_pgrp ? tp->t_pgrp->pg_id : 0,
2213 	    tp->t_pgrp ? tp->t_pgrp->pg_jobc : 0);
2214 	db_printf("\tsession: %p", tp->t_session);
2215 	if (tp->t_session != NULL)
2216 	    db_printf(" count %u leader %p tty %p sid %d login %s",
2217 		tp->t_session->s_count, tp->t_session->s_leader,
2218 		tp->t_session->s_ttyp, tp->t_session->s_sid,
2219 		tp->t_session->s_login);
2220 	db_printf("\n");
2221 	db_printf("\tsessioncnt: %u\n", tp->t_sessioncnt);
2222 	db_printf("\tdevswsoftc: %p\n", tp->t_devswsoftc);
2223 	db_printf("\thooksoftc: %p\n", tp->t_hooksoftc);
2224 	db_printf("\tdev: %p\n", tp->t_dev);
2225 }
2226 
2227 /* DDB command to list TTYs. */
2228 DB_SHOW_ALL_COMMAND(ttys, db_show_all_ttys)
2229 {
2230 	struct tty *tp;
2231 	size_t isiz, osiz;
2232 	int i, j;
2233 
2234 	/* Make the output look like `pstat -t'. */
2235 	db_printf("PTR        ");
2236 #if defined(__LP64__)
2237 	db_printf("        ");
2238 #endif
2239 	db_printf("      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   "
2240 	    "COL  SESS  PGID STATE\n");
2241 
2242 	TAILQ_FOREACH(tp, &tty_list, t_list) {
2243 		isiz = tp->t_inq.ti_nblocks * TTYINQ_DATASIZE;
2244 		osiz = tp->t_outq.to_nblocks * TTYOUTQ_DATASIZE;
2245 
2246 		db_printf("%p %10s %5zu %4u %4u %4zu %5zu %4u %4zu %5u %5d %5d ",
2247 		    tp,
2248 		    tty_devname(tp),
2249 		    isiz,
2250 		    tp->t_inq.ti_linestart - tp->t_inq.ti_begin,
2251 		    tp->t_inq.ti_end - tp->t_inq.ti_linestart,
2252 		    isiz - tp->t_inlow,
2253 		    osiz,
2254 		    tp->t_outq.to_end - tp->t_outq.to_begin,
2255 		    osiz - tp->t_outlow,
2256 		    MIN(tp->t_column, 99999),
2257 		    tp->t_session ? tp->t_session->s_sid : 0,
2258 		    tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
2259 
2260 		/* Flag bits. */
2261 		for (i = j = 0; ttystates[i].flag; i++)
2262 			if (tp->t_flags & ttystates[i].flag) {
2263 				db_printf("%c", ttystates[i].val);
2264 				j++;
2265 			}
2266 		if (j == 0)
2267 			db_printf("-");
2268 		db_printf("\n");
2269 	}
2270 }
2271 #endif /* DDB */
2272