xref: /freebsd/sys/kern/tty.c (revision abac203368a6069d3d557a71a60a843707694d65)
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 	/* Destroy associated buffers already. */
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 	/* Make sure we haven't leaked buffers. */
1035 	MPASS(ttyinq_getsize(&tp->t_inq) == 0);
1036 	MPASS(ttyoutq_getsize(&tp->t_outq) == 0);
1037 
1038 	seldrain(&tp->t_inpoll);
1039 	seldrain(&tp->t_outpoll);
1040 	knlist_destroy(&tp->t_inpoll.si_note);
1041 	knlist_destroy(&tp->t_outpoll.si_note);
1042 
1043 	cv_destroy(&tp->t_inwait);
1044 	cv_destroy(&tp->t_outwait);
1045 	cv_destroy(&tp->t_bgwait);
1046 	cv_destroy(&tp->t_dcdwait);
1047 	cv_destroy(&tp->t_outserwait);
1048 
1049 	if (tp->t_mtx == &tp->t_mtxobj)
1050 		mtx_destroy(&tp->t_mtxobj);
1051 	ttydevsw_free(tp);
1052 	free(tp, M_TTY);
1053 }
1054 
1055 static void
1056 tty_rel_free(struct tty *tp)
1057 {
1058 	struct cdev *dev;
1059 
1060 	tty_lock_assert(tp, MA_OWNED);
1061 
1062 #define	TF_ACTIVITY	(TF_GONE|TF_OPENED|TF_HOOK|TF_OPENCLOSE)
1063 	if (tp->t_sessioncnt != 0 || (tp->t_flags & TF_ACTIVITY) != TF_GONE) {
1064 		/* TTY is still in use. */
1065 		tty_unlock(tp);
1066 		return;
1067 	}
1068 
1069 	/* TTY can be deallocated. */
1070 	dev = tp->t_dev;
1071 	tp->t_dev = NULL;
1072 	tty_unlock(tp);
1073 
1074 	if (dev != NULL) {
1075 		sx_xlock(&tty_list_sx);
1076 		TAILQ_REMOVE(&tty_list, tp, t_list);
1077 		tty_list_count--;
1078 		sx_xunlock(&tty_list_sx);
1079 		destroy_dev_sched_cb(dev, tty_dealloc, tp);
1080 	}
1081 }
1082 
1083 void
1084 tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
1085 {
1086 	MPASS(tp->t_sessioncnt > 0);
1087 	tty_lock_assert(tp, MA_OWNED);
1088 
1089 	if (tp->t_pgrp == pg)
1090 		tp->t_pgrp = NULL;
1091 
1092 	tty_unlock(tp);
1093 }
1094 
1095 void
1096 tty_rel_sess(struct tty *tp, struct session *sess)
1097 {
1098 	MPASS(tp->t_sessioncnt > 0);
1099 
1100 	/* Current session has left. */
1101 	if (tp->t_session == sess) {
1102 		tp->t_session = NULL;
1103 		MPASS(tp->t_pgrp == NULL);
1104 	}
1105 	tp->t_sessioncnt--;
1106 	tty_rel_free(tp);
1107 }
1108 
1109 void
1110 tty_rel_gone(struct tty *tp)
1111 {
1112 	MPASS(!tty_gone(tp));
1113 
1114 	/* Simulate carrier removal. */
1115 	ttydisc_modem(tp, 0);
1116 
1117 	/* Wake up all blocked threads. */
1118 	tty_wakeup(tp, FREAD|FWRITE);
1119 	cv_broadcast(&tp->t_bgwait);
1120 	cv_broadcast(&tp->t_dcdwait);
1121 
1122 	tp->t_flags |= TF_GONE;
1123 	tty_rel_free(tp);
1124 }
1125 
1126 /*
1127  * Exposing information about current TTY's through sysctl
1128  */
1129 
1130 static void
1131 tty_to_xtty(struct tty *tp, struct xtty *xt)
1132 {
1133 	tty_lock_assert(tp, MA_OWNED);
1134 
1135 	xt->xt_size = sizeof(struct xtty);
1136 	xt->xt_insize = ttyinq_getsize(&tp->t_inq);
1137 	xt->xt_incc = ttyinq_bytescanonicalized(&tp->t_inq);
1138 	xt->xt_inlc = ttyinq_bytesline(&tp->t_inq);
1139 	xt->xt_inlow = tp->t_inlow;
1140 	xt->xt_outsize = ttyoutq_getsize(&tp->t_outq);
1141 	xt->xt_outcc = ttyoutq_bytesused(&tp->t_outq);
1142 	xt->xt_outlow = tp->t_outlow;
1143 	xt->xt_column = tp->t_column;
1144 	xt->xt_pgid = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
1145 	xt->xt_sid = tp->t_session ? tp->t_session->s_sid : 0;
1146 	xt->xt_flags = tp->t_flags;
1147 	xt->xt_dev = tp->t_dev ? dev2udev(tp->t_dev) : NODEV;
1148 }
1149 
1150 static int
1151 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
1152 {
1153 	unsigned long lsize;
1154 	struct xtty *xtlist, *xt;
1155 	struct tty *tp;
1156 	int error;
1157 
1158 	sx_slock(&tty_list_sx);
1159 	lsize = tty_list_count * sizeof(struct xtty);
1160 	if (lsize == 0) {
1161 		sx_sunlock(&tty_list_sx);
1162 		return (0);
1163 	}
1164 
1165 	xtlist = xt = malloc(lsize, M_TTY, M_WAITOK);
1166 
1167 	TAILQ_FOREACH(tp, &tty_list, t_list) {
1168 		tty_lock(tp);
1169 		tty_to_xtty(tp, xt);
1170 		tty_unlock(tp);
1171 		xt++;
1172 	}
1173 	sx_sunlock(&tty_list_sx);
1174 
1175 	error = SYSCTL_OUT(req, xtlist, lsize);
1176 	free(xtlist, M_TTY);
1177 	return (error);
1178 }
1179 
1180 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
1181 	0, 0, sysctl_kern_ttys, "S,xtty", "List of TTYs");
1182 
1183 /*
1184  * Device node creation. Device has been set up, now we can expose it to
1185  * the user.
1186  */
1187 
1188 int
1189 tty_makedevf(struct tty *tp, struct ucred *cred, int flags,
1190     const char *fmt, ...)
1191 {
1192 	va_list ap;
1193 	struct make_dev_args args;
1194 	struct cdev *dev, *init, *lock, *cua, *cinit, *clock;
1195 	const char *prefix = "tty";
1196 	char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
1197 	uid_t uid;
1198 	gid_t gid;
1199 	mode_t mode;
1200 	int error;
1201 
1202 	/* Remove "tty" prefix from devices like PTY's. */
1203 	if (tp->t_flags & TF_NOPREFIX)
1204 		prefix = "";
1205 
1206 	va_start(ap, fmt);
1207 	vsnrprintf(name, sizeof name, 32, fmt, ap);
1208 	va_end(ap);
1209 
1210 	if (cred == NULL) {
1211 		/* System device. */
1212 		uid = UID_ROOT;
1213 		gid = GID_WHEEL;
1214 		mode = S_IRUSR|S_IWUSR;
1215 	} else {
1216 		/* User device. */
1217 		uid = cred->cr_ruid;
1218 		gid = GID_TTY;
1219 		mode = S_IRUSR|S_IWUSR|S_IWGRP;
1220 	}
1221 
1222 	flags = flags & TTYMK_CLONING ? MAKEDEV_REF : 0;
1223 	flags |= MAKEDEV_CHECKNAME;
1224 
1225 	/* Master call-in device. */
1226 	make_dev_args_init(&args);
1227 	args.mda_flags = flags;
1228 	args.mda_devsw = &ttydev_cdevsw;
1229 	args.mda_cr = cred;
1230 	args.mda_uid = uid;
1231 	args.mda_gid = gid;
1232 	args.mda_mode = mode;
1233 	args.mda_si_drv1 = tp;
1234 	error = make_dev_s(&args, &dev, "%s%s", prefix, name);
1235 	if (error != 0)
1236 		return (error);
1237 	tp->t_dev = dev;
1238 
1239 	init = lock = cua = cinit = clock = NULL;
1240 
1241 	/* Slave call-in devices. */
1242 	if (tp->t_flags & TF_INITLOCK) {
1243 		args.mda_devsw = &ttyil_cdevsw;
1244 		args.mda_unit = TTYUNIT_INIT;
1245 		args.mda_si_drv1 = tp;
1246 		args.mda_si_drv2 = &tp->t_termios_init_in;
1247 		error = make_dev_s(&args, &init, "%s%s.init", prefix, name);
1248 		if (error != 0)
1249 			goto fail;
1250 		dev_depends(dev, init);
1251 
1252 		args.mda_unit = TTYUNIT_LOCK;
1253 		args.mda_si_drv2 = &tp->t_termios_lock_in;
1254 		error = make_dev_s(&args, &lock, "%s%s.lock", prefix, name);
1255 		if (error != 0)
1256 			goto fail;
1257 		dev_depends(dev, lock);
1258 	}
1259 
1260 	/* Call-out devices. */
1261 	if (tp->t_flags & TF_CALLOUT) {
1262 		make_dev_args_init(&args);
1263 		args.mda_flags = flags;
1264 		args.mda_devsw = &ttydev_cdevsw;
1265 		args.mda_cr = cred;
1266 		args.mda_uid = UID_UUCP;
1267 		args.mda_gid = GID_DIALER;
1268 		args.mda_mode = 0660;
1269 		args.mda_unit = TTYUNIT_CALLOUT;
1270 		args.mda_si_drv1 = tp;
1271 		error = make_dev_s(&args, &cua, "cua%s", name);
1272 		if (error != 0)
1273 			goto fail;
1274 		dev_depends(dev, cua);
1275 
1276 		/* Slave call-out devices. */
1277 		if (tp->t_flags & TF_INITLOCK) {
1278 			args.mda_devsw = &ttyil_cdevsw;
1279 			args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_INIT;
1280 			args.mda_si_drv2 = &tp->t_termios_init_out;
1281 			error = make_dev_s(&args, &cinit, "cua%s.init", name);
1282 			if (error != 0)
1283 				goto fail;
1284 			dev_depends(dev, cinit);
1285 
1286 			args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_LOCK;
1287 			args.mda_si_drv2 = &tp->t_termios_lock_out;
1288 			error = make_dev_s(&args, &clock, "cua%s.lock", name);
1289 			if (error != 0)
1290 				goto fail;
1291 			dev_depends(dev, clock);
1292 		}
1293 	}
1294 
1295 	sx_xlock(&tty_list_sx);
1296 	TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
1297 	tty_list_count++;
1298 	sx_xunlock(&tty_list_sx);
1299 
1300 	return (0);
1301 
1302 fail:
1303 	destroy_dev(dev);
1304 	if (init)
1305 		destroy_dev(init);
1306 	if (lock)
1307 		destroy_dev(lock);
1308 	if (cinit)
1309 		destroy_dev(cinit);
1310 	if (clock)
1311 		destroy_dev(clock);
1312 
1313 	return (error);
1314 }
1315 
1316 /*
1317  * Signalling processes.
1318  */
1319 
1320 void
1321 tty_signal_sessleader(struct tty *tp, int sig)
1322 {
1323 	struct proc *p;
1324 
1325 	tty_lock_assert(tp, MA_OWNED);
1326 	MPASS(sig >= 1 && sig < NSIG);
1327 
1328 	/* Make signals start output again. */
1329 	tp->t_flags &= ~TF_STOPPED;
1330 
1331 	if (tp->t_session != NULL && tp->t_session->s_leader != NULL) {
1332 		p = tp->t_session->s_leader;
1333 		PROC_LOCK(p);
1334 		kern_psignal(p, sig);
1335 		PROC_UNLOCK(p);
1336 	}
1337 }
1338 
1339 void
1340 tty_signal_pgrp(struct tty *tp, int sig)
1341 {
1342 	ksiginfo_t ksi;
1343 
1344 	tty_lock_assert(tp, MA_OWNED);
1345 	MPASS(sig >= 1 && sig < NSIG);
1346 
1347 	/* Make signals start output again. */
1348 	tp->t_flags &= ~TF_STOPPED;
1349 
1350 	if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
1351 		tty_info(tp);
1352 	if (tp->t_pgrp != NULL) {
1353 		ksiginfo_init(&ksi);
1354 		ksi.ksi_signo = sig;
1355 		ksi.ksi_code = SI_KERNEL;
1356 		PGRP_LOCK(tp->t_pgrp);
1357 		pgsignal(tp->t_pgrp, sig, 1, &ksi);
1358 		PGRP_UNLOCK(tp->t_pgrp);
1359 	}
1360 }
1361 
1362 void
1363 tty_wakeup(struct tty *tp, int flags)
1364 {
1365 	if (tp->t_flags & TF_ASYNC && tp->t_sigio != NULL)
1366 		pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
1367 
1368 	if (flags & FWRITE) {
1369 		cv_broadcast(&tp->t_outwait);
1370 		selwakeup(&tp->t_outpoll);
1371 		KNOTE_LOCKED(&tp->t_outpoll.si_note, 0);
1372 	}
1373 	if (flags & FREAD) {
1374 		cv_broadcast(&tp->t_inwait);
1375 		selwakeup(&tp->t_inpoll);
1376 		KNOTE_LOCKED(&tp->t_inpoll.si_note, 0);
1377 	}
1378 }
1379 
1380 int
1381 tty_wait(struct tty *tp, struct cv *cv)
1382 {
1383 	int error;
1384 	int revokecnt = tp->t_revokecnt;
1385 
1386 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1387 	MPASS(!tty_gone(tp));
1388 
1389 	error = cv_wait_sig(cv, tp->t_mtx);
1390 
1391 	/* Bail out when the device slipped away. */
1392 	if (tty_gone(tp))
1393 		return (ENXIO);
1394 
1395 	/* Restart the system call when we may have been revoked. */
1396 	if (tp->t_revokecnt != revokecnt)
1397 		return (ERESTART);
1398 
1399 	return (error);
1400 }
1401 
1402 int
1403 tty_timedwait(struct tty *tp, struct cv *cv, int hz)
1404 {
1405 	int error;
1406 	int revokecnt = tp->t_revokecnt;
1407 
1408 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1409 	MPASS(!tty_gone(tp));
1410 
1411 	error = cv_timedwait_sig(cv, tp->t_mtx, hz);
1412 
1413 	/* Bail out when the device slipped away. */
1414 	if (tty_gone(tp))
1415 		return (ENXIO);
1416 
1417 	/* Restart the system call when we may have been revoked. */
1418 	if (tp->t_revokecnt != revokecnt)
1419 		return (ERESTART);
1420 
1421 	return (error);
1422 }
1423 
1424 void
1425 tty_flush(struct tty *tp, int flags)
1426 {
1427 	if (flags & FWRITE) {
1428 		tp->t_flags &= ~TF_HIWAT_OUT;
1429 		ttyoutq_flush(&tp->t_outq);
1430 		tty_wakeup(tp, FWRITE);
1431 		ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
1432 	}
1433 	if (flags & FREAD) {
1434 		tty_hiwat_in_unblock(tp);
1435 		ttyinq_flush(&tp->t_inq);
1436 		ttydevsw_inwakeup(tp);
1437 		ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
1438 	}
1439 }
1440 
1441 void
1442 tty_set_winsize(struct tty *tp, const struct winsize *wsz)
1443 {
1444 
1445 	if (memcmp(&tp->t_winsize, wsz, sizeof(*wsz)) == 0)
1446 		return;
1447 	tp->t_winsize = *wsz;
1448 	tty_signal_pgrp(tp, SIGWINCH);
1449 }
1450 
1451 static int
1452 tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, int fflag,
1453     struct thread *td)
1454 {
1455 	int error;
1456 
1457 	switch (cmd) {
1458 	/*
1459 	 * Modem commands.
1460 	 * The SER_* and TIOCM_* flags are the same, but one bit
1461 	 * shifted. I don't know why.
1462 	 */
1463 	case TIOCSDTR:
1464 		ttydevsw_modem(tp, SER_DTR, 0);
1465 		return (0);
1466 	case TIOCCDTR:
1467 		ttydevsw_modem(tp, 0, SER_DTR);
1468 		return (0);
1469 	case TIOCMSET: {
1470 		int bits = *(int *)data;
1471 		ttydevsw_modem(tp,
1472 		    (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1,
1473 		    ((~bits) & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1474 		return (0);
1475 	}
1476 	case TIOCMBIS: {
1477 		int bits = *(int *)data;
1478 		ttydevsw_modem(tp, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1, 0);
1479 		return (0);
1480 	}
1481 	case TIOCMBIC: {
1482 		int bits = *(int *)data;
1483 		ttydevsw_modem(tp, 0, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1484 		return (0);
1485 	}
1486 	case TIOCMGET:
1487 		*(int *)data = TIOCM_LE + (ttydevsw_modem(tp, 0, 0) << 1);
1488 		return (0);
1489 
1490 	case FIOASYNC:
1491 		if (*(int *)data)
1492 			tp->t_flags |= TF_ASYNC;
1493 		else
1494 			tp->t_flags &= ~TF_ASYNC;
1495 		return (0);
1496 	case FIONBIO:
1497 		/* This device supports non-blocking operation. */
1498 		return (0);
1499 	case FIONREAD:
1500 		*(int *)data = ttyinq_bytescanonicalized(&tp->t_inq);
1501 		return (0);
1502 	case FIONWRITE:
1503 	case TIOCOUTQ:
1504 		*(int *)data = ttyoutq_bytesused(&tp->t_outq);
1505 		return (0);
1506 	case FIOSETOWN:
1507 		if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1508 			/* Not allowed to set ownership. */
1509 			return (ENOTTY);
1510 
1511 		/* Temporarily unlock the TTY to set ownership. */
1512 		tty_unlock(tp);
1513 		error = fsetown(*(int *)data, &tp->t_sigio);
1514 		tty_lock(tp);
1515 		return (error);
1516 	case FIOGETOWN:
1517 		if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1518 			/* Not allowed to set ownership. */
1519 			return (ENOTTY);
1520 
1521 		/* Get ownership. */
1522 		*(int *)data = fgetown(&tp->t_sigio);
1523 		return (0);
1524 	case TIOCGETA:
1525 		/* Obtain terminal flags through tcgetattr(). */
1526 		*(struct termios*)data = tp->t_termios;
1527 		return (0);
1528 	case TIOCSETA:
1529 	case TIOCSETAW:
1530 	case TIOCSETAF: {
1531 		struct termios *t = data;
1532 
1533 		/*
1534 		 * Who makes up these funny rules? According to POSIX,
1535 		 * input baud rate is set equal to the output baud rate
1536 		 * when zero.
1537 		 */
1538 		if (t->c_ispeed == 0)
1539 			t->c_ispeed = t->c_ospeed;
1540 
1541 		/* Discard any unsupported bits. */
1542 		t->c_iflag &= TTYSUP_IFLAG;
1543 		t->c_oflag &= TTYSUP_OFLAG;
1544 		t->c_lflag &= TTYSUP_LFLAG;
1545 		t->c_cflag &= TTYSUP_CFLAG;
1546 
1547 		/* Set terminal flags through tcsetattr(). */
1548 		if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
1549 			error = tty_drain(tp, 0);
1550 			if (error)
1551 				return (error);
1552 			if (cmd == TIOCSETAF)
1553 				tty_flush(tp, FREAD);
1554 		}
1555 
1556 		/*
1557 		 * Only call param() when the flags really change.
1558 		 */
1559 		if ((t->c_cflag & CIGNORE) == 0 &&
1560 		    (tp->t_termios.c_cflag != t->c_cflag ||
1561 		    ((tp->t_termios.c_iflag ^ t->c_iflag) &
1562 		    (IXON|IXOFF|IXANY)) ||
1563 		    tp->t_termios.c_ispeed != t->c_ispeed ||
1564 		    tp->t_termios.c_ospeed != t->c_ospeed)) {
1565 			error = ttydevsw_param(tp, t);
1566 			if (error)
1567 				return (error);
1568 
1569 			/* XXX: CLOCAL? */
1570 
1571 			tp->t_termios.c_cflag = t->c_cflag & ~CIGNORE;
1572 			tp->t_termios.c_ispeed = t->c_ispeed;
1573 			tp->t_termios.c_ospeed = t->c_ospeed;
1574 
1575 			/* Baud rate has changed - update watermarks. */
1576 			tty_watermarks(tp);
1577 		}
1578 
1579 		/* Copy new non-device driver parameters. */
1580 		tp->t_termios.c_iflag = t->c_iflag;
1581 		tp->t_termios.c_oflag = t->c_oflag;
1582 		tp->t_termios.c_lflag = t->c_lflag;
1583 		memcpy(&tp->t_termios.c_cc, t->c_cc, sizeof t->c_cc);
1584 
1585 		ttydisc_optimize(tp);
1586 
1587 		if ((t->c_lflag & ICANON) == 0) {
1588 			/*
1589 			 * When in non-canonical mode, wake up all
1590 			 * readers. Canonicalize any partial input. VMIN
1591 			 * and VTIME could also be adjusted.
1592 			 */
1593 			ttyinq_canonicalize(&tp->t_inq);
1594 			tty_wakeup(tp, FREAD);
1595 		}
1596 
1597 		/*
1598 		 * For packet mode: notify the PTY consumer that VSTOP
1599 		 * and VSTART may have been changed.
1600 		 */
1601 		if (tp->t_termios.c_iflag & IXON &&
1602 		    tp->t_termios.c_cc[VSTOP] == CTRL('S') &&
1603 		    tp->t_termios.c_cc[VSTART] == CTRL('Q'))
1604 			ttydevsw_pktnotify(tp, TIOCPKT_DOSTOP);
1605 		else
1606 			ttydevsw_pktnotify(tp, TIOCPKT_NOSTOP);
1607 		return (0);
1608 	}
1609 	case TIOCGETD:
1610 		/* For compatibility - we only support TTYDISC. */
1611 		*(int *)data = TTYDISC;
1612 		return (0);
1613 	case TIOCGPGRP:
1614 		if (!tty_is_ctty(tp, td->td_proc))
1615 			return (ENOTTY);
1616 
1617 		if (tp->t_pgrp != NULL)
1618 			*(int *)data = tp->t_pgrp->pg_id;
1619 		else
1620 			*(int *)data = NO_PID;
1621 		return (0);
1622 	case TIOCGSID:
1623 		if (!tty_is_ctty(tp, td->td_proc))
1624 			return (ENOTTY);
1625 
1626 		MPASS(tp->t_session);
1627 		*(int *)data = tp->t_session->s_sid;
1628 		return (0);
1629 	case TIOCSCTTY: {
1630 		struct proc *p = td->td_proc;
1631 
1632 		/* XXX: This looks awful. */
1633 		tty_unlock(tp);
1634 		sx_xlock(&proctree_lock);
1635 		tty_lock(tp);
1636 
1637 		if (!SESS_LEADER(p)) {
1638 			/* Only the session leader may do this. */
1639 			sx_xunlock(&proctree_lock);
1640 			return (EPERM);
1641 		}
1642 
1643 		if (tp->t_session != NULL && tp->t_session == p->p_session) {
1644 			/* This is already our controlling TTY. */
1645 			sx_xunlock(&proctree_lock);
1646 			return (0);
1647 		}
1648 
1649 		if (p->p_session->s_ttyp != NULL ||
1650 		    (tp->t_session != NULL && tp->t_session->s_ttyvp != NULL &&
1651 		    tp->t_session->s_ttyvp->v_type != VBAD)) {
1652 			/*
1653 			 * There is already a relation between a TTY and
1654 			 * a session, or the caller is not the session
1655 			 * leader.
1656 			 *
1657 			 * Allow the TTY to be stolen when the vnode is
1658 			 * invalid, but the reference to the TTY is
1659 			 * still active.  This allows immediate reuse of
1660 			 * TTYs of which the session leader has been
1661 			 * killed or the TTY revoked.
1662 			 */
1663 			sx_xunlock(&proctree_lock);
1664 			return (EPERM);
1665 		}
1666 
1667 		/* Connect the session to the TTY. */
1668 		tp->t_session = p->p_session;
1669 		tp->t_session->s_ttyp = tp;
1670 		tp->t_sessioncnt++;
1671 		sx_xunlock(&proctree_lock);
1672 
1673 		/* Assign foreground process group. */
1674 		tp->t_pgrp = p->p_pgrp;
1675 		PROC_LOCK(p);
1676 		p->p_flag |= P_CONTROLT;
1677 		PROC_UNLOCK(p);
1678 
1679 		return (0);
1680 	}
1681 	case TIOCSPGRP: {
1682 		struct pgrp *pg;
1683 
1684 		/*
1685 		 * XXX: Temporarily unlock the TTY to locate the process
1686 		 * group. This code would be lot nicer if we would ever
1687 		 * decompose proctree_lock.
1688 		 */
1689 		tty_unlock(tp);
1690 		sx_slock(&proctree_lock);
1691 		pg = pgfind(*(int *)data);
1692 		if (pg != NULL)
1693 			PGRP_UNLOCK(pg);
1694 		if (pg == NULL || pg->pg_session != td->td_proc->p_session) {
1695 			sx_sunlock(&proctree_lock);
1696 			tty_lock(tp);
1697 			return (EPERM);
1698 		}
1699 		tty_lock(tp);
1700 
1701 		/*
1702 		 * Determine if this TTY is the controlling TTY after
1703 		 * relocking the TTY.
1704 		 */
1705 		if (!tty_is_ctty(tp, td->td_proc)) {
1706 			sx_sunlock(&proctree_lock);
1707 			return (ENOTTY);
1708 		}
1709 		tp->t_pgrp = pg;
1710 		sx_sunlock(&proctree_lock);
1711 
1712 		/* Wake up the background process groups. */
1713 		cv_broadcast(&tp->t_bgwait);
1714 		return (0);
1715 	}
1716 	case TIOCFLUSH: {
1717 		int flags = *(int *)data;
1718 
1719 		if (flags == 0)
1720 			flags = (FREAD|FWRITE);
1721 		else
1722 			flags &= (FREAD|FWRITE);
1723 		tty_flush(tp, flags);
1724 		return (0);
1725 	}
1726 	case TIOCDRAIN:
1727 		/* Drain TTY output. */
1728 		return tty_drain(tp, 0);
1729 	case TIOCCONS:
1730 		/* Set terminal as console TTY. */
1731 		if (*(int *)data) {
1732 			error = priv_check(td, PRIV_TTY_CONSOLE);
1733 			if (error)
1734 				return (error);
1735 
1736 			/*
1737 			 * XXX: constty should really need to be locked!
1738 			 * XXX: allow disconnected constty's to be stolen!
1739 			 */
1740 
1741 			if (constty == tp)
1742 				return (0);
1743 			if (constty != NULL)
1744 				return (EBUSY);
1745 
1746 			tty_unlock(tp);
1747 			constty_set(tp);
1748 			tty_lock(tp);
1749 		} else if (constty == tp) {
1750 			constty_clear();
1751 		}
1752 		return (0);
1753 	case TIOCGWINSZ:
1754 		/* Obtain window size. */
1755 		*(struct winsize*)data = tp->t_winsize;
1756 		return (0);
1757 	case TIOCSWINSZ:
1758 		/* Set window size. */
1759 		tty_set_winsize(tp, data);
1760 		return (0);
1761 	case TIOCEXCL:
1762 		tp->t_flags |= TF_EXCLUDE;
1763 		return (0);
1764 	case TIOCNXCL:
1765 		tp->t_flags &= ~TF_EXCLUDE;
1766 		return (0);
1767 	case TIOCSTOP:
1768 		tp->t_flags |= TF_STOPPED;
1769 		ttydevsw_pktnotify(tp, TIOCPKT_STOP);
1770 		return (0);
1771 	case TIOCSTART:
1772 		tp->t_flags &= ~TF_STOPPED;
1773 		ttydevsw_outwakeup(tp);
1774 		ttydevsw_pktnotify(tp, TIOCPKT_START);
1775 		return (0);
1776 	case TIOCSTAT:
1777 		tty_info(tp);
1778 		return (0);
1779 	case TIOCSTI:
1780 		if ((fflag & FREAD) == 0 && priv_check(td, PRIV_TTY_STI))
1781 			return (EPERM);
1782 		if (!tty_is_ctty(tp, td->td_proc) &&
1783 		    priv_check(td, PRIV_TTY_STI))
1784 			return (EACCES);
1785 		ttydisc_rint(tp, *(char *)data, 0);
1786 		ttydisc_rint_done(tp);
1787 		return (0);
1788 	}
1789 
1790 #ifdef COMPAT_43TTY
1791 	return tty_ioctl_compat(tp, cmd, data, fflag, td);
1792 #else /* !COMPAT_43TTY */
1793 	return (ENOIOCTL);
1794 #endif /* COMPAT_43TTY */
1795 }
1796 
1797 int
1798 tty_ioctl(struct tty *tp, u_long cmd, void *data, int fflag, struct thread *td)
1799 {
1800 	int error;
1801 
1802 	tty_lock_assert(tp, MA_OWNED);
1803 
1804 	if (tty_gone(tp))
1805 		return (ENXIO);
1806 
1807 	error = ttydevsw_ioctl(tp, cmd, data, td);
1808 	if (error == ENOIOCTL)
1809 		error = tty_generic_ioctl(tp, cmd, data, fflag, td);
1810 
1811 	return (error);
1812 }
1813 
1814 dev_t
1815 tty_udev(struct tty *tp)
1816 {
1817 	if (tp->t_dev)
1818 		return dev2udev(tp->t_dev);
1819 	else
1820 		return NODEV;
1821 }
1822 
1823 int
1824 tty_checkoutq(struct tty *tp)
1825 {
1826 
1827 	/* 256 bytes should be enough to print a log message. */
1828 	return (ttyoutq_bytesleft(&tp->t_outq) >= 256);
1829 }
1830 
1831 void
1832 tty_hiwat_in_block(struct tty *tp)
1833 {
1834 
1835 	if ((tp->t_flags & TF_HIWAT_IN) == 0 &&
1836 	    tp->t_termios.c_iflag & IXOFF &&
1837 	    tp->t_termios.c_cc[VSTOP] != _POSIX_VDISABLE) {
1838 		/*
1839 		 * Input flow control. Only enter the high watermark when we
1840 		 * can successfully store the VSTOP character.
1841 		 */
1842 		if (ttyoutq_write_nofrag(&tp->t_outq,
1843 		    &tp->t_termios.c_cc[VSTOP], 1) == 0)
1844 			tp->t_flags |= TF_HIWAT_IN;
1845 	} else {
1846 		/* No input flow control. */
1847 		tp->t_flags |= TF_HIWAT_IN;
1848 	}
1849 }
1850 
1851 void
1852 tty_hiwat_in_unblock(struct tty *tp)
1853 {
1854 
1855 	if (tp->t_flags & TF_HIWAT_IN &&
1856 	    tp->t_termios.c_iflag & IXOFF &&
1857 	    tp->t_termios.c_cc[VSTART] != _POSIX_VDISABLE) {
1858 		/*
1859 		 * Input flow control. Only leave the high watermark when we
1860 		 * can successfully store the VSTART character.
1861 		 */
1862 		if (ttyoutq_write_nofrag(&tp->t_outq,
1863 		    &tp->t_termios.c_cc[VSTART], 1) == 0)
1864 			tp->t_flags &= ~TF_HIWAT_IN;
1865 	} else {
1866 		/* No input flow control. */
1867 		tp->t_flags &= ~TF_HIWAT_IN;
1868 	}
1869 
1870 	if (!tty_gone(tp))
1871 		ttydevsw_inwakeup(tp);
1872 }
1873 
1874 /*
1875  * TTY hooks interface.
1876  */
1877 
1878 static int
1879 ttyhook_defrint(struct tty *tp, char c, int flags)
1880 {
1881 
1882 	if (ttyhook_rint_bypass(tp, &c, 1) != 1)
1883 		return (-1);
1884 
1885 	return (0);
1886 }
1887 
1888 int
1889 ttyhook_register(struct tty **rtp, struct proc *p, int fd,
1890     struct ttyhook *th, void *softc)
1891 {
1892 	struct tty *tp;
1893 	struct file *fp;
1894 	struct cdev *dev;
1895 	struct cdevsw *cdp;
1896 	struct filedesc *fdp;
1897 	cap_rights_t rights;
1898 	int error, ref;
1899 
1900 	/* Validate the file descriptor. */
1901 	fdp = p->p_fd;
1902 	error = fget_unlocked(fdp, fd, cap_rights_init(&rights, CAP_TTYHOOK),
1903 	    &fp, NULL);
1904 	if (error != 0)
1905 		return (error);
1906 	if (fp->f_ops == &badfileops) {
1907 		error = EBADF;
1908 		goto done1;
1909 	}
1910 
1911 	/*
1912 	 * Make sure the vnode is bound to a character device.
1913 	 * Unlocked check for the vnode type is ok there, because we
1914 	 * only shall prevent calling devvn_refthread on the file that
1915 	 * never has been opened over a character device.
1916 	 */
1917 	if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR) {
1918 		error = EINVAL;
1919 		goto done1;
1920 	}
1921 
1922 	/* Make sure it is a TTY. */
1923 	cdp = devvn_refthread(fp->f_vnode, &dev, &ref);
1924 	if (cdp == NULL) {
1925 		error = ENXIO;
1926 		goto done1;
1927 	}
1928 	if (dev != fp->f_data) {
1929 		error = ENXIO;
1930 		goto done2;
1931 	}
1932 	if (cdp != &ttydev_cdevsw) {
1933 		error = ENOTTY;
1934 		goto done2;
1935 	}
1936 	tp = dev->si_drv1;
1937 
1938 	/* Try to attach the hook to the TTY. */
1939 	error = EBUSY;
1940 	tty_lock(tp);
1941 	MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
1942 	if (tp->t_flags & TF_HOOK)
1943 		goto done3;
1944 
1945 	tp->t_flags |= TF_HOOK;
1946 	tp->t_hook = th;
1947 	tp->t_hooksoftc = softc;
1948 	*rtp = tp;
1949 	error = 0;
1950 
1951 	/* Maybe we can switch into bypass mode now. */
1952 	ttydisc_optimize(tp);
1953 
1954 	/* Silently convert rint() calls to rint_bypass() when possible. */
1955 	if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
1956 		th->th_rint = ttyhook_defrint;
1957 
1958 done3:	tty_unlock(tp);
1959 done2:	dev_relthread(dev, ref);
1960 done1:	fdrop(fp, curthread);
1961 	return (error);
1962 }
1963 
1964 void
1965 ttyhook_unregister(struct tty *tp)
1966 {
1967 
1968 	tty_lock_assert(tp, MA_OWNED);
1969 	MPASS(tp->t_flags & TF_HOOK);
1970 
1971 	/* Disconnect the hook. */
1972 	tp->t_flags &= ~TF_HOOK;
1973 	tp->t_hook = NULL;
1974 
1975 	/* Maybe we need to leave bypass mode. */
1976 	ttydisc_optimize(tp);
1977 
1978 	/* Maybe deallocate the TTY as well. */
1979 	tty_rel_free(tp);
1980 }
1981 
1982 /*
1983  * /dev/console handling.
1984  */
1985 
1986 static int
1987 ttyconsdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
1988 {
1989 	struct tty *tp;
1990 
1991 	/* System has no console device. */
1992 	if (dev_console_filename == NULL)
1993 		return (ENXIO);
1994 
1995 	/* Look up corresponding TTY by device name. */
1996 	sx_slock(&tty_list_sx);
1997 	TAILQ_FOREACH(tp, &tty_list, t_list) {
1998 		if (strcmp(dev_console_filename, tty_devname(tp)) == 0) {
1999 			dev_console->si_drv1 = tp;
2000 			break;
2001 		}
2002 	}
2003 	sx_sunlock(&tty_list_sx);
2004 
2005 	/* System console has no TTY associated. */
2006 	if (dev_console->si_drv1 == NULL)
2007 		return (ENXIO);
2008 
2009 	return (ttydev_open(dev, oflags, devtype, td));
2010 }
2011 
2012 static int
2013 ttyconsdev_write(struct cdev *dev, struct uio *uio, int ioflag)
2014 {
2015 
2016 	log_console(uio);
2017 
2018 	return (ttydev_write(dev, uio, ioflag));
2019 }
2020 
2021 /*
2022  * /dev/console is a little different than normal TTY's.  When opened,
2023  * it determines which TTY to use.  When data gets written to it, it
2024  * will be logged in the kernel message buffer.
2025  */
2026 static struct cdevsw ttyconsdev_cdevsw = {
2027 	.d_version	= D_VERSION,
2028 	.d_open		= ttyconsdev_open,
2029 	.d_close	= ttydev_close,
2030 	.d_read		= ttydev_read,
2031 	.d_write	= ttyconsdev_write,
2032 	.d_ioctl	= ttydev_ioctl,
2033 	.d_kqfilter	= ttydev_kqfilter,
2034 	.d_poll		= ttydev_poll,
2035 	.d_mmap		= ttydev_mmap,
2036 	.d_name		= "ttyconsdev",
2037 	.d_flags	= D_TTY,
2038 };
2039 
2040 static void
2041 ttyconsdev_init(void *unused)
2042 {
2043 
2044 	dev_console = make_dev_credf(MAKEDEV_ETERNAL, &ttyconsdev_cdevsw, 0,
2045 	    NULL, UID_ROOT, GID_WHEEL, 0600, "console");
2046 }
2047 
2048 SYSINIT(tty, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyconsdev_init, NULL);
2049 
2050 void
2051 ttyconsdev_select(const char *name)
2052 {
2053 
2054 	dev_console_filename = name;
2055 }
2056 
2057 /*
2058  * Debugging routines.
2059  */
2060 
2061 #include "opt_ddb.h"
2062 #ifdef DDB
2063 #include <ddb/ddb.h>
2064 #include <ddb/db_sym.h>
2065 
2066 static struct {
2067 	int flag;
2068 	char val;
2069 } ttystates[] = {
2070 #if 0
2071 	{ TF_NOPREFIX,		'N' },
2072 #endif
2073 	{ TF_INITLOCK,		'I' },
2074 	{ TF_CALLOUT,		'C' },
2075 
2076 	/* Keep these together -> 'Oi' and 'Oo'. */
2077 	{ TF_OPENED,		'O' },
2078 	{ TF_OPENED_IN,		'i' },
2079 	{ TF_OPENED_OUT,	'o' },
2080 	{ TF_OPENED_CONS,	'c' },
2081 
2082 	{ TF_GONE,		'G' },
2083 	{ TF_OPENCLOSE,		'B' },
2084 	{ TF_ASYNC,		'Y' },
2085 	{ TF_LITERAL,		'L' },
2086 
2087 	/* Keep these together -> 'Hi' and 'Ho'. */
2088 	{ TF_HIWAT,		'H' },
2089 	{ TF_HIWAT_IN,		'i' },
2090 	{ TF_HIWAT_OUT,		'o' },
2091 
2092 	{ TF_STOPPED,		'S' },
2093 	{ TF_EXCLUDE,		'X' },
2094 	{ TF_BYPASS,		'l' },
2095 	{ TF_ZOMBIE,		'Z' },
2096 	{ TF_HOOK,		's' },
2097 
2098 	/* Keep these together -> 'bi' and 'bo'. */
2099 	{ TF_BUSY,		'b' },
2100 	{ TF_BUSY_IN,		'i' },
2101 	{ TF_BUSY_OUT,		'o' },
2102 
2103 	{ 0,			'\0'},
2104 };
2105 
2106 #define	TTY_FLAG_BITS \
2107 	"\20\1NOPREFIX\2INITLOCK\3CALLOUT\4OPENED_IN\5OPENED_OUT\6GONE" \
2108 	"\7OPENCLOSE\10ASYNC\11LITERAL\12HIWAT_IN\13HIWAT_OUT\14STOPPED" \
2109 	"\15EXCLUDE\16BYPASS\17ZOMBIE\20HOOK"
2110 
2111 #define DB_PRINTSYM(name, addr) \
2112 	db_printf("%s  " #name ": ", sep); \
2113 	db_printsym((db_addr_t) addr, DB_STGY_ANY); \
2114 	db_printf("\n");
2115 
2116 static void
2117 _db_show_devsw(const char *sep, const struct ttydevsw *tsw)
2118 {
2119 	db_printf("%sdevsw: ", sep);
2120 	db_printsym((db_addr_t)tsw, DB_STGY_ANY);
2121 	db_printf(" (%p)\n", tsw);
2122 	DB_PRINTSYM(open, tsw->tsw_open);
2123 	DB_PRINTSYM(close, tsw->tsw_close);
2124 	DB_PRINTSYM(outwakeup, tsw->tsw_outwakeup);
2125 	DB_PRINTSYM(inwakeup, tsw->tsw_inwakeup);
2126 	DB_PRINTSYM(ioctl, tsw->tsw_ioctl);
2127 	DB_PRINTSYM(param, tsw->tsw_param);
2128 	DB_PRINTSYM(modem, tsw->tsw_modem);
2129 	DB_PRINTSYM(mmap, tsw->tsw_mmap);
2130 	DB_PRINTSYM(pktnotify, tsw->tsw_pktnotify);
2131 	DB_PRINTSYM(free, tsw->tsw_free);
2132 }
2133 static void
2134 _db_show_hooks(const char *sep, const struct ttyhook *th)
2135 {
2136 	db_printf("%shook: ", sep);
2137 	db_printsym((db_addr_t)th, DB_STGY_ANY);
2138 	db_printf(" (%p)\n", th);
2139 	if (th == NULL)
2140 		return;
2141 	DB_PRINTSYM(rint, th->th_rint);
2142 	DB_PRINTSYM(rint_bypass, th->th_rint_bypass);
2143 	DB_PRINTSYM(rint_done, th->th_rint_done);
2144 	DB_PRINTSYM(rint_poll, th->th_rint_poll);
2145 	DB_PRINTSYM(getc_inject, th->th_getc_inject);
2146 	DB_PRINTSYM(getc_capture, th->th_getc_capture);
2147 	DB_PRINTSYM(getc_poll, th->th_getc_poll);
2148 	DB_PRINTSYM(close, th->th_close);
2149 }
2150 
2151 static void
2152 _db_show_termios(const char *name, const struct termios *t)
2153 {
2154 
2155 	db_printf("%s: iflag 0x%x oflag 0x%x cflag 0x%x "
2156 	    "lflag 0x%x ispeed %u ospeed %u\n", name,
2157 	    t->c_iflag, t->c_oflag, t->c_cflag, t->c_lflag,
2158 	    t->c_ispeed, t->c_ospeed);
2159 }
2160 
2161 /* DDB command to show TTY statistics. */
2162 DB_SHOW_COMMAND(tty, db_show_tty)
2163 {
2164 	struct tty *tp;
2165 
2166 	if (!have_addr) {
2167 		db_printf("usage: show tty <addr>\n");
2168 		return;
2169 	}
2170 	tp = (struct tty *)addr;
2171 
2172 	db_printf("0x%p: %s\n", tp, tty_devname(tp));
2173 	db_printf("\tmtx: %p\n", tp->t_mtx);
2174 	db_printf("\tflags: %b\n", tp->t_flags, TTY_FLAG_BITS);
2175 	db_printf("\trevokecnt: %u\n", tp->t_revokecnt);
2176 
2177 	/* Buffering mechanisms. */
2178 	db_printf("\tinq: %p begin %u linestart %u reprint %u end %u "
2179 	    "nblocks %u quota %u\n", &tp->t_inq, tp->t_inq.ti_begin,
2180 	    tp->t_inq.ti_linestart, tp->t_inq.ti_reprint, tp->t_inq.ti_end,
2181 	    tp->t_inq.ti_nblocks, tp->t_inq.ti_quota);
2182 	db_printf("\toutq: %p begin %u end %u nblocks %u quota %u\n",
2183 	    &tp->t_outq, tp->t_outq.to_begin, tp->t_outq.to_end,
2184 	    tp->t_outq.to_nblocks, tp->t_outq.to_quota);
2185 	db_printf("\tinlow: %zu\n", tp->t_inlow);
2186 	db_printf("\toutlow: %zu\n", tp->t_outlow);
2187 	_db_show_termios("\ttermios", &tp->t_termios);
2188 	db_printf("\twinsize: row %u col %u xpixel %u ypixel %u\n",
2189 	    tp->t_winsize.ws_row, tp->t_winsize.ws_col,
2190 	    tp->t_winsize.ws_xpixel, tp->t_winsize.ws_ypixel);
2191 	db_printf("\tcolumn: %u\n", tp->t_column);
2192 	db_printf("\twritepos: %u\n", tp->t_writepos);
2193 	db_printf("\tcompatflags: 0x%x\n", tp->t_compatflags);
2194 
2195 	/* Init/lock-state devices. */
2196 	_db_show_termios("\ttermios_init_in", &tp->t_termios_init_in);
2197 	_db_show_termios("\ttermios_init_out", &tp->t_termios_init_out);
2198 	_db_show_termios("\ttermios_lock_in", &tp->t_termios_lock_in);
2199 	_db_show_termios("\ttermios_lock_out", &tp->t_termios_lock_out);
2200 
2201 	/* Hooks */
2202 	_db_show_devsw("\t", tp->t_devsw);
2203 	_db_show_hooks("\t", tp->t_hook);
2204 
2205 	/* Process info. */
2206 	db_printf("\tpgrp: %p gid %d jobc %d\n", tp->t_pgrp,
2207 	    tp->t_pgrp ? tp->t_pgrp->pg_id : 0,
2208 	    tp->t_pgrp ? tp->t_pgrp->pg_jobc : 0);
2209 	db_printf("\tsession: %p", tp->t_session);
2210 	if (tp->t_session != NULL)
2211 	    db_printf(" count %u leader %p tty %p sid %d login %s",
2212 		tp->t_session->s_count, tp->t_session->s_leader,
2213 		tp->t_session->s_ttyp, tp->t_session->s_sid,
2214 		tp->t_session->s_login);
2215 	db_printf("\n");
2216 	db_printf("\tsessioncnt: %u\n", tp->t_sessioncnt);
2217 	db_printf("\tdevswsoftc: %p\n", tp->t_devswsoftc);
2218 	db_printf("\thooksoftc: %p\n", tp->t_hooksoftc);
2219 	db_printf("\tdev: %p\n", tp->t_dev);
2220 }
2221 
2222 /* DDB command to list TTYs. */
2223 DB_SHOW_ALL_COMMAND(ttys, db_show_all_ttys)
2224 {
2225 	struct tty *tp;
2226 	size_t isiz, osiz;
2227 	int i, j;
2228 
2229 	/* Make the output look like `pstat -t'. */
2230 	db_printf("PTR        ");
2231 #if defined(__LP64__)
2232 	db_printf("        ");
2233 #endif
2234 	db_printf("      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   "
2235 	    "COL  SESS  PGID STATE\n");
2236 
2237 	TAILQ_FOREACH(tp, &tty_list, t_list) {
2238 		isiz = tp->t_inq.ti_nblocks * TTYINQ_DATASIZE;
2239 		osiz = tp->t_outq.to_nblocks * TTYOUTQ_DATASIZE;
2240 
2241 		db_printf("%p %10s %5zu %4u %4u %4zu %5zu %4u %4zu %5u %5d %5d ",
2242 		    tp,
2243 		    tty_devname(tp),
2244 		    isiz,
2245 		    tp->t_inq.ti_linestart - tp->t_inq.ti_begin,
2246 		    tp->t_inq.ti_end - tp->t_inq.ti_linestart,
2247 		    isiz - tp->t_inlow,
2248 		    osiz,
2249 		    tp->t_outq.to_end - tp->t_outq.to_begin,
2250 		    osiz - tp->t_outlow,
2251 		    MIN(tp->t_column, 99999),
2252 		    tp->t_session ? tp->t_session->s_sid : 0,
2253 		    tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
2254 
2255 		/* Flag bits. */
2256 		for (i = j = 0; ttystates[i].flag; i++)
2257 			if (tp->t_flags & ttystates[i].flag) {
2258 				db_printf("%c", ttystates[i].val);
2259 				j++;
2260 			}
2261 		if (j == 0)
2262 			db_printf("-");
2263 		db_printf("\n");
2264 	}
2265 }
2266 #endif /* DDB */
2267