xref: /freebsd/sys/kern/tty.c (revision f95c930e6701aa675377bc5871ea490dd565eeba)
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) {
136 		ttydevsw_outwakeup(tp);
137 		/* Could be handled synchronously. */
138 		bytesused = ttyoutq_bytesused(&tp->t_outq);
139 		if (bytesused == 0)
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 = 0;
241 
242 	while ((tp = dev->si_drv1) == NULL) {
243 		error = tsleep(&dev->si_drv1, PCATCH, "ttdrv1", 1);
244 		if (error != EWOULDBLOCK)
245 			return (error);
246 	}
247 
248 	tty_lock(tp);
249 	if (tty_gone(tp)) {
250 		/* Device is already gone. */
251 		tty_unlock(tp);
252 		return (ENXIO);
253 	}
254 
255 	/*
256 	 * Block when other processes are currently opening or closing
257 	 * the TTY.
258 	 */
259 	while (tp->t_flags & TF_OPENCLOSE) {
260 		error = tty_wait(tp, &tp->t_dcdwait);
261 		if (error != 0) {
262 			tty_unlock(tp);
263 			return (error);
264 		}
265 	}
266 	tp->t_flags |= TF_OPENCLOSE;
267 
268 	/*
269 	 * Make sure the "tty" and "cua" device cannot be opened at the
270 	 * same time.
271 	 */
272 	if (TTY_CALLOUT(tp, dev)) {
273 		if (tp->t_flags & TF_OPENED_IN) {
274 			error = EBUSY;
275 			goto done;
276 		}
277 	} else {
278 		if (tp->t_flags & TF_OPENED_OUT) {
279 			error = EBUSY;
280 			goto done;
281 		}
282 	}
283 
284 	if (tp->t_flags & TF_EXCLUDE && priv_check(td, PRIV_TTY_EXCLUSIVE)) {
285 		error = EBUSY;
286 		goto done;
287 	}
288 
289 	if (!tty_opened(tp)) {
290 		/* Set proper termios flags. */
291 		if (TTY_CALLOUT(tp, dev))
292 			tp->t_termios = tp->t_termios_init_out;
293 		else
294 			tp->t_termios = tp->t_termios_init_in;
295 		ttydevsw_param(tp, &tp->t_termios);
296 		/* Prevent modem control on callout devices and /dev/console. */
297 		if (TTY_CALLOUT(tp, dev) || dev == dev_console)
298 			tp->t_termios.c_cflag |= CLOCAL;
299 
300 		ttydevsw_modem(tp, SER_DTR|SER_RTS, 0);
301 
302 		error = ttydevsw_open(tp);
303 		if (error != 0)
304 			goto done;
305 
306 		ttydisc_open(tp);
307 		tty_watermarks(tp); /* XXXGL: drops lock */
308 	}
309 
310 	/* Wait for Carrier Detect. */
311 	if ((oflags & O_NONBLOCK) == 0 &&
312 	    (tp->t_termios.c_cflag & CLOCAL) == 0) {
313 		while ((ttydevsw_modem(tp, 0, 0) & SER_DCD) == 0) {
314 			error = tty_wait(tp, &tp->t_dcdwait);
315 			if (error != 0)
316 				goto done;
317 		}
318 	}
319 
320 	if (dev == dev_console)
321 		tp->t_flags |= TF_OPENED_CONS;
322 	else if (TTY_CALLOUT(tp, dev))
323 		tp->t_flags |= TF_OPENED_OUT;
324 	else
325 		tp->t_flags |= TF_OPENED_IN;
326 
327 done:	tp->t_flags &= ~TF_OPENCLOSE;
328 	cv_broadcast(&tp->t_dcdwait);
329 	ttydev_leave(tp);
330 
331 	return (error);
332 }
333 
334 static int
335 ttydev_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
336 {
337 	struct tty *tp = dev->si_drv1;
338 
339 	tty_lock(tp);
340 
341 	/*
342 	 * Don't actually close the device if it is being used as the
343 	 * console.
344 	 */
345 	MPASS((tp->t_flags & TF_OPENED) != TF_OPENED);
346 	if (dev == dev_console)
347 		tp->t_flags &= ~TF_OPENED_CONS;
348 	else
349 		tp->t_flags &= ~(TF_OPENED_IN|TF_OPENED_OUT);
350 
351 	if (tp->t_flags & TF_OPENED) {
352 		tty_unlock(tp);
353 		return (0);
354 	}
355 
356 	/*
357 	 * This can only be called once. The callin and the callout
358 	 * devices cannot be opened at the same time.
359 	 */
360 	tp->t_flags &= ~(TF_EXCLUDE|TF_STOPPED);
361 
362 	/* Properly wake up threads that are stuck - revoke(). */
363 	tp->t_revokecnt++;
364 	tty_wakeup(tp, FREAD|FWRITE);
365 	cv_broadcast(&tp->t_bgwait);
366 	cv_broadcast(&tp->t_dcdwait);
367 
368 	ttydev_leave(tp);
369 
370 	return (0);
371 }
372 
373 static __inline int
374 tty_is_ctty(struct tty *tp, struct proc *p)
375 {
376 	tty_lock_assert(tp, MA_OWNED);
377 
378 	return (p->p_session == tp->t_session && p->p_flag & P_CONTROLT);
379 }
380 
381 int
382 tty_wait_background(struct tty *tp, struct thread *td, int sig)
383 {
384 	struct proc *p = td->td_proc;
385 	struct pgrp *pg;
386 	ksiginfo_t ksi;
387 	int error;
388 
389 	MPASS(sig == SIGTTIN || sig == SIGTTOU);
390 	tty_lock_assert(tp, MA_OWNED);
391 
392 	for (;;) {
393 		PROC_LOCK(p);
394 		/*
395 		 * The process should only sleep, when:
396 		 * - This terminal is the controling terminal
397 		 * - Its process group is not the foreground process
398 		 *   group
399 		 * - The parent process isn't waiting for the child to
400 		 *   exit
401 		 * - the signal to send to the process isn't masked
402 		 */
403 		if (!tty_is_ctty(tp, p) || p->p_pgrp == tp->t_pgrp) {
404 			/* Allow the action to happen. */
405 			PROC_UNLOCK(p);
406 			return (0);
407 		}
408 
409 		if (SIGISMEMBER(p->p_sigacts->ps_sigignore, sig) ||
410 		    SIGISMEMBER(td->td_sigmask, sig)) {
411 			/* Only allow them in write()/ioctl(). */
412 			PROC_UNLOCK(p);
413 			return (sig == SIGTTOU ? 0 : EIO);
414 		}
415 
416 		pg = p->p_pgrp;
417 		if (p->p_flag & P_PPWAIT || pg->pg_jobc == 0) {
418 			/* Don't allow the action to happen. */
419 			PROC_UNLOCK(p);
420 			return (EIO);
421 		}
422 		PROC_UNLOCK(p);
423 
424 		/*
425 		 * Send the signal and sleep until we're the new
426 		 * foreground process group.
427 		 */
428 		if (sig != 0) {
429 			ksiginfo_init(&ksi);
430 			ksi.ksi_code = SI_KERNEL;
431 			ksi.ksi_signo = sig;
432 			sig = 0;
433 		}
434 		PGRP_LOCK(pg);
435 		pgsignal(pg, ksi.ksi_signo, 1, &ksi);
436 		PGRP_UNLOCK(pg);
437 
438 		error = tty_wait(tp, &tp->t_bgwait);
439 		if (error)
440 			return (error);
441 	}
442 }
443 
444 static int
445 ttydev_read(struct cdev *dev, struct uio *uio, int ioflag)
446 {
447 	struct tty *tp = dev->si_drv1;
448 	int error;
449 
450 	error = ttydev_enter(tp);
451 	if (error)
452 		goto done;
453 	error = ttydisc_read(tp, uio, ioflag);
454 	tty_unlock(tp);
455 
456 	/*
457 	 * The read() call should not throw an error when the device is
458 	 * being destroyed. Silently convert it to an EOF.
459 	 */
460 done:	if (error == ENXIO)
461 		error = 0;
462 	return (error);
463 }
464 
465 static int
466 ttydev_write(struct cdev *dev, struct uio *uio, int ioflag)
467 {
468 	struct tty *tp = dev->si_drv1;
469 	int error;
470 
471 	error = ttydev_enter(tp);
472 	if (error)
473 		return (error);
474 
475 	if (tp->t_termios.c_lflag & TOSTOP) {
476 		error = tty_wait_background(tp, curthread, SIGTTOU);
477 		if (error)
478 			goto done;
479 	}
480 
481 	if (ioflag & IO_NDELAY && tp->t_flags & TF_BUSY_OUT) {
482 		/* Allow non-blocking writes to bypass serialization. */
483 		error = ttydisc_write(tp, uio, ioflag);
484 	} else {
485 		/* Serialize write() calls. */
486 		while (tp->t_flags & TF_BUSY_OUT) {
487 			error = tty_wait(tp, &tp->t_outserwait);
488 			if (error)
489 				goto done;
490 		}
491 
492 		tp->t_flags |= TF_BUSY_OUT;
493 		error = ttydisc_write(tp, uio, ioflag);
494 		tp->t_flags &= ~TF_BUSY_OUT;
495 		cv_signal(&tp->t_outserwait);
496 	}
497 
498 done:	tty_unlock(tp);
499 	return (error);
500 }
501 
502 static int
503 ttydev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
504     struct thread *td)
505 {
506 	struct tty *tp = dev->si_drv1;
507 	int error;
508 
509 	error = ttydev_enter(tp);
510 	if (error)
511 		return (error);
512 
513 	switch (cmd) {
514 	case TIOCCBRK:
515 	case TIOCCONS:
516 	case TIOCDRAIN:
517 	case TIOCEXCL:
518 	case TIOCFLUSH:
519 	case TIOCNXCL:
520 	case TIOCSBRK:
521 	case TIOCSCTTY:
522 	case TIOCSETA:
523 	case TIOCSETAF:
524 	case TIOCSETAW:
525 	case TIOCSPGRP:
526 	case TIOCSTART:
527 	case TIOCSTAT:
528 	case TIOCSTI:
529 	case TIOCSTOP:
530 	case TIOCSWINSZ:
531 #if 0
532 	case TIOCSDRAINWAIT:
533 	case TIOCSETD:
534 #endif
535 #ifdef COMPAT_43TTY
536 	case  TIOCLBIC:
537 	case  TIOCLBIS:
538 	case  TIOCLSET:
539 	case  TIOCSETC:
540 	case OTIOCSETD:
541 	case  TIOCSETN:
542 	case  TIOCSETP:
543 	case  TIOCSLTC:
544 #endif /* COMPAT_43TTY */
545 		/*
546 		 * If the ioctl() causes the TTY to be modified, let it
547 		 * wait in the background.
548 		 */
549 		error = tty_wait_background(tp, curthread, SIGTTOU);
550 		if (error)
551 			goto done;
552 	}
553 
554 	if (cmd == TIOCSETA || cmd == TIOCSETAW || cmd == TIOCSETAF) {
555 		struct termios *old = &tp->t_termios;
556 		struct termios *new = (struct termios *)data;
557 		struct termios *lock = TTY_CALLOUT(tp, dev) ?
558 		    &tp->t_termios_lock_out : &tp->t_termios_lock_in;
559 		int cc;
560 
561 		/*
562 		 * Lock state devices.  Just overwrite the values of the
563 		 * commands that are currently in use.
564 		 */
565 		new->c_iflag = (old->c_iflag & lock->c_iflag) |
566 		    (new->c_iflag & ~lock->c_iflag);
567 		new->c_oflag = (old->c_oflag & lock->c_oflag) |
568 		    (new->c_oflag & ~lock->c_oflag);
569 		new->c_cflag = (old->c_cflag & lock->c_cflag) |
570 		    (new->c_cflag & ~lock->c_cflag);
571 		new->c_lflag = (old->c_lflag & lock->c_lflag) |
572 		    (new->c_lflag & ~lock->c_lflag);
573 		for (cc = 0; cc < NCCS; ++cc)
574 			if (lock->c_cc[cc])
575 				new->c_cc[cc] = old->c_cc[cc];
576 		if (lock->c_ispeed)
577 			new->c_ispeed = old->c_ispeed;
578 		if (lock->c_ospeed)
579 			new->c_ospeed = old->c_ospeed;
580 	}
581 
582 	error = tty_ioctl(tp, cmd, data, fflag, td);
583 done:	tty_unlock(tp);
584 
585 	return (error);
586 }
587 
588 static int
589 ttydev_poll(struct cdev *dev, int events, struct thread *td)
590 {
591 	struct tty *tp = dev->si_drv1;
592 	int error, revents = 0;
593 
594 	error = ttydev_enter(tp);
595 	if (error)
596 		return ((events & (POLLIN|POLLRDNORM)) | POLLHUP);
597 
598 	if (events & (POLLIN|POLLRDNORM)) {
599 		/* See if we can read something. */
600 		if (ttydisc_read_poll(tp) > 0)
601 			revents |= events & (POLLIN|POLLRDNORM);
602 	}
603 
604 	if (tp->t_flags & TF_ZOMBIE) {
605 		/* Hangup flag on zombie state. */
606 		revents |= POLLHUP;
607 	} else if (events & (POLLOUT|POLLWRNORM)) {
608 		/* See if we can write something. */
609 		if (ttydisc_write_poll(tp) > 0)
610 			revents |= events & (POLLOUT|POLLWRNORM);
611 	}
612 
613 	if (revents == 0) {
614 		if (events & (POLLIN|POLLRDNORM))
615 			selrecord(td, &tp->t_inpoll);
616 		if (events & (POLLOUT|POLLWRNORM))
617 			selrecord(td, &tp->t_outpoll);
618 	}
619 
620 	tty_unlock(tp);
621 
622 	return (revents);
623 }
624 
625 static int
626 ttydev_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
627     int nprot, vm_memattr_t *memattr)
628 {
629 	struct tty *tp = dev->si_drv1;
630 	int error;
631 
632 	/* Handle mmap() through the driver. */
633 
634 	error = ttydev_enter(tp);
635 	if (error)
636 		return (-1);
637 	error = ttydevsw_mmap(tp, offset, paddr, nprot, memattr);
638 	tty_unlock(tp);
639 
640 	return (error);
641 }
642 
643 /*
644  * kqueue support.
645  */
646 
647 static void
648 tty_kqops_read_detach(struct knote *kn)
649 {
650 	struct tty *tp = kn->kn_hook;
651 
652 	knlist_remove(&tp->t_inpoll.si_note, kn, 0);
653 }
654 
655 static int
656 tty_kqops_read_event(struct knote *kn, long hint)
657 {
658 	struct tty *tp = kn->kn_hook;
659 
660 	tty_lock_assert(tp, MA_OWNED);
661 
662 	if (tty_gone(tp) || tp->t_flags & TF_ZOMBIE) {
663 		kn->kn_flags |= EV_EOF;
664 		return (1);
665 	} else {
666 		kn->kn_data = ttydisc_read_poll(tp);
667 		return (kn->kn_data > 0);
668 	}
669 }
670 
671 static void
672 tty_kqops_write_detach(struct knote *kn)
673 {
674 	struct tty *tp = kn->kn_hook;
675 
676 	knlist_remove(&tp->t_outpoll.si_note, kn, 0);
677 }
678 
679 static int
680 tty_kqops_write_event(struct knote *kn, long hint)
681 {
682 	struct tty *tp = kn->kn_hook;
683 
684 	tty_lock_assert(tp, MA_OWNED);
685 
686 	if (tty_gone(tp)) {
687 		kn->kn_flags |= EV_EOF;
688 		return (1);
689 	} else {
690 		kn->kn_data = ttydisc_write_poll(tp);
691 		return (kn->kn_data > 0);
692 	}
693 }
694 
695 static struct filterops tty_kqops_read = {
696 	.f_isfd = 1,
697 	.f_detach = tty_kqops_read_detach,
698 	.f_event = tty_kqops_read_event,
699 };
700 static struct filterops tty_kqops_write = {
701 	.f_isfd = 1,
702 	.f_detach = tty_kqops_write_detach,
703 	.f_event = tty_kqops_write_event,
704 };
705 
706 static int
707 ttydev_kqfilter(struct cdev *dev, struct knote *kn)
708 {
709 	struct tty *tp = dev->si_drv1;
710 	int error;
711 
712 	error = ttydev_enter(tp);
713 	if (error)
714 		return (error);
715 
716 	switch (kn->kn_filter) {
717 	case EVFILT_READ:
718 		kn->kn_hook = tp;
719 		kn->kn_fop = &tty_kqops_read;
720 		knlist_add(&tp->t_inpoll.si_note, kn, 1);
721 		break;
722 	case EVFILT_WRITE:
723 		kn->kn_hook = tp;
724 		kn->kn_fop = &tty_kqops_write;
725 		knlist_add(&tp->t_outpoll.si_note, kn, 1);
726 		break;
727 	default:
728 		error = EINVAL;
729 		break;
730 	}
731 
732 	tty_unlock(tp);
733 	return (error);
734 }
735 
736 static struct cdevsw ttydev_cdevsw = {
737 	.d_version	= D_VERSION,
738 	.d_open		= ttydev_open,
739 	.d_close	= ttydev_close,
740 	.d_read		= ttydev_read,
741 	.d_write	= ttydev_write,
742 	.d_ioctl	= ttydev_ioctl,
743 	.d_kqfilter	= ttydev_kqfilter,
744 	.d_poll		= ttydev_poll,
745 	.d_mmap		= ttydev_mmap,
746 	.d_name		= "ttydev",
747 	.d_flags	= D_TTY,
748 };
749 
750 /*
751  * Init/lock-state devices
752  */
753 
754 static int
755 ttyil_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
756 {
757 	struct tty *tp;
758 	int error = 0;
759 
760 	while ((tp = dev->si_drv1) == NULL) {
761 		error = tsleep(&dev->si_drv1, PCATCH, "ttdrv1", 1);
762 		if (error != EWOULDBLOCK)
763 			return (error);
764 	}
765 	tty_lock(tp);
766 	if (tty_gone(tp))
767 		error = ENODEV;
768 	tty_unlock(tp);
769 
770 	return (error);
771 }
772 
773 static int
774 ttyil_close(struct cdev *dev, int flag, int mode, struct thread *td)
775 {
776 	return (0);
777 }
778 
779 static int
780 ttyil_rdwr(struct cdev *dev, struct uio *uio, int ioflag)
781 {
782 	return (ENODEV);
783 }
784 
785 static int
786 ttyil_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
787     struct thread *td)
788 {
789 	struct tty *tp = dev->si_drv1;
790 	int error;
791 
792 	tty_lock(tp);
793 	if (tty_gone(tp)) {
794 		error = ENODEV;
795 		goto done;
796 	}
797 
798 	error = ttydevsw_cioctl(tp, dev2unit(dev), cmd, data, td);
799 	if (error != ENOIOCTL)
800 		goto done;
801 	error = 0;
802 
803 	switch (cmd) {
804 	case TIOCGETA:
805 		/* Obtain terminal flags through tcgetattr(). */
806 		*(struct termios*)data = *(struct termios*)dev->si_drv2;
807 		break;
808 	case TIOCSETA:
809 		/* Set terminal flags through tcsetattr(). */
810 		error = priv_check(td, PRIV_TTY_SETA);
811 		if (error)
812 			break;
813 		*(struct termios*)dev->si_drv2 = *(struct termios*)data;
814 		break;
815 	case TIOCGETD:
816 		*(int *)data = TTYDISC;
817 		break;
818 	case TIOCGWINSZ:
819 		bzero(data, sizeof(struct winsize));
820 		break;
821 	default:
822 		error = ENOTTY;
823 	}
824 
825 done:	tty_unlock(tp);
826 	return (error);
827 }
828 
829 static struct cdevsw ttyil_cdevsw = {
830 	.d_version	= D_VERSION,
831 	.d_open		= ttyil_open,
832 	.d_close	= ttyil_close,
833 	.d_read		= ttyil_rdwr,
834 	.d_write	= ttyil_rdwr,
835 	.d_ioctl	= ttyil_ioctl,
836 	.d_name		= "ttyil",
837 	.d_flags	= D_TTY,
838 };
839 
840 static void
841 tty_init_termios(struct tty *tp)
842 {
843 	struct termios *t = &tp->t_termios_init_in;
844 
845 	t->c_cflag = TTYDEF_CFLAG;
846 	t->c_iflag = TTYDEF_IFLAG;
847 	t->c_lflag = TTYDEF_LFLAG;
848 	t->c_oflag = TTYDEF_OFLAG;
849 	t->c_ispeed = TTYDEF_SPEED;
850 	t->c_ospeed = TTYDEF_SPEED;
851 	memcpy(&t->c_cc, ttydefchars, sizeof ttydefchars);
852 
853 	tp->t_termios_init_out = *t;
854 }
855 
856 void
857 tty_init_console(struct tty *tp, speed_t s)
858 {
859 	struct termios *ti = &tp->t_termios_init_in;
860 	struct termios *to = &tp->t_termios_init_out;
861 
862 	if (s != 0) {
863 		ti->c_ispeed = ti->c_ospeed = s;
864 		to->c_ispeed = to->c_ospeed = s;
865 	}
866 
867 	ti->c_cflag |= CLOCAL;
868 	to->c_cflag |= CLOCAL;
869 }
870 
871 /*
872  * Standard device routine implementations, mostly meant for
873  * pseudo-terminal device drivers. When a driver creates a new terminal
874  * device class, missing routines are patched.
875  */
876 
877 static int
878 ttydevsw_defopen(struct tty *tp)
879 {
880 
881 	return (0);
882 }
883 
884 static void
885 ttydevsw_defclose(struct tty *tp)
886 {
887 }
888 
889 static void
890 ttydevsw_defoutwakeup(struct tty *tp)
891 {
892 
893 	panic("Terminal device has output, while not implemented");
894 }
895 
896 static void
897 ttydevsw_definwakeup(struct tty *tp)
898 {
899 }
900 
901 static int
902 ttydevsw_defioctl(struct tty *tp, u_long cmd, caddr_t data, struct thread *td)
903 {
904 
905 	return (ENOIOCTL);
906 }
907 
908 static int
909 ttydevsw_defcioctl(struct tty *tp, int unit, u_long cmd, caddr_t data, struct thread *td)
910 {
911 
912 	return (ENOIOCTL);
913 }
914 
915 static int
916 ttydevsw_defparam(struct tty *tp, struct termios *t)
917 {
918 
919 	/*
920 	 * Allow the baud rate to be adjusted for pseudo-devices, but at
921 	 * least restrict it to 115200 to prevent excessive buffer
922 	 * usage.  Also disallow 0, to prevent foot shooting.
923 	 */
924 	if (t->c_ispeed < B50)
925 		t->c_ispeed = B50;
926 	else if (t->c_ispeed > B115200)
927 		t->c_ispeed = B115200;
928 	if (t->c_ospeed < B50)
929 		t->c_ospeed = B50;
930 	else if (t->c_ospeed > B115200)
931 		t->c_ospeed = B115200;
932 	t->c_cflag |= CREAD;
933 
934 	return (0);
935 }
936 
937 static int
938 ttydevsw_defmodem(struct tty *tp, int sigon, int sigoff)
939 {
940 
941 	/* Simulate a carrier to make the TTY layer happy. */
942 	return (SER_DCD);
943 }
944 
945 static int
946 ttydevsw_defmmap(struct tty *tp, vm_ooffset_t offset, vm_paddr_t *paddr,
947     int nprot, vm_memattr_t *memattr)
948 {
949 
950 	return (-1);
951 }
952 
953 static void
954 ttydevsw_defpktnotify(struct tty *tp, char event)
955 {
956 }
957 
958 static void
959 ttydevsw_deffree(void *softc)
960 {
961 
962 	panic("Terminal device freed without a free-handler");
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 #undef PATCH_FUNC
1000 
1001 	tp = malloc(sizeof(struct tty), M_TTY, M_WAITOK|M_ZERO);
1002 	tp->t_devsw = tsw;
1003 	tp->t_devswsoftc = sc;
1004 	tp->t_flags = tsw->tsw_flags;
1005 
1006 	tty_init_termios(tp);
1007 
1008 	cv_init(&tp->t_inwait, "ttyin");
1009 	cv_init(&tp->t_outwait, "ttyout");
1010 	cv_init(&tp->t_outserwait, "ttyosr");
1011 	cv_init(&tp->t_bgwait, "ttybg");
1012 	cv_init(&tp->t_dcdwait, "ttydcd");
1013 
1014 	/* Allow drivers to use a custom mutex to lock the TTY. */
1015 	if (mutex != NULL) {
1016 		tp->t_mtx = mutex;
1017 	} else {
1018 		tp->t_mtx = &tp->t_mtxobj;
1019 		mtx_init(&tp->t_mtxobj, "ttymtx", NULL, MTX_DEF);
1020 	}
1021 
1022 	knlist_init_mtx(&tp->t_inpoll.si_note, tp->t_mtx);
1023 	knlist_init_mtx(&tp->t_outpoll.si_note, tp->t_mtx);
1024 
1025 	return (tp);
1026 }
1027 
1028 static void
1029 tty_dealloc(void *arg)
1030 {
1031 	struct tty *tp = arg;
1032 
1033 	/* Make sure we haven't leaked buffers. */
1034 	MPASS(ttyinq_getsize(&tp->t_inq) == 0);
1035 	MPASS(ttyoutq_getsize(&tp->t_outq) == 0);
1036 
1037 	seldrain(&tp->t_inpoll);
1038 	seldrain(&tp->t_outpoll);
1039 	knlist_destroy(&tp->t_inpoll.si_note);
1040 	knlist_destroy(&tp->t_outpoll.si_note);
1041 
1042 	cv_destroy(&tp->t_inwait);
1043 	cv_destroy(&tp->t_outwait);
1044 	cv_destroy(&tp->t_bgwait);
1045 	cv_destroy(&tp->t_dcdwait);
1046 	cv_destroy(&tp->t_outserwait);
1047 
1048 	if (tp->t_mtx == &tp->t_mtxobj)
1049 		mtx_destroy(&tp->t_mtxobj);
1050 	ttydevsw_free(tp);
1051 	free(tp, M_TTY);
1052 }
1053 
1054 static void
1055 tty_rel_free(struct tty *tp)
1056 {
1057 	struct cdev *dev;
1058 
1059 	tty_lock_assert(tp, MA_OWNED);
1060 
1061 #define	TF_ACTIVITY	(TF_GONE|TF_OPENED|TF_HOOK|TF_OPENCLOSE)
1062 	if (tp->t_sessioncnt != 0 || (tp->t_flags & TF_ACTIVITY) != TF_GONE) {
1063 		/* TTY is still in use. */
1064 		tty_unlock(tp);
1065 		return;
1066 	}
1067 
1068 	/* TTY can be deallocated. */
1069 	dev = tp->t_dev;
1070 	tp->t_dev = NULL;
1071 	tty_unlock(tp);
1072 
1073 	if (dev != NULL) {
1074 		sx_xlock(&tty_list_sx);
1075 		TAILQ_REMOVE(&tty_list, tp, t_list);
1076 		tty_list_count--;
1077 		sx_xunlock(&tty_list_sx);
1078 		destroy_dev_sched_cb(dev, tty_dealloc, tp);
1079 	}
1080 }
1081 
1082 void
1083 tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
1084 {
1085 	MPASS(tp->t_sessioncnt > 0);
1086 	tty_lock_assert(tp, MA_OWNED);
1087 
1088 	if (tp->t_pgrp == pg)
1089 		tp->t_pgrp = NULL;
1090 
1091 	tty_unlock(tp);
1092 }
1093 
1094 void
1095 tty_rel_sess(struct tty *tp, struct session *sess)
1096 {
1097 	MPASS(tp->t_sessioncnt > 0);
1098 
1099 	/* Current session has left. */
1100 	if (tp->t_session == sess) {
1101 		tp->t_session = NULL;
1102 		MPASS(tp->t_pgrp == NULL);
1103 	}
1104 	tp->t_sessioncnt--;
1105 	tty_rel_free(tp);
1106 }
1107 
1108 void
1109 tty_rel_gone(struct tty *tp)
1110 {
1111 	MPASS(!tty_gone(tp));
1112 
1113 	/* Simulate carrier removal. */
1114 	ttydisc_modem(tp, 0);
1115 
1116 	/* Wake up all blocked threads. */
1117 	tty_wakeup(tp, FREAD|FWRITE);
1118 	cv_broadcast(&tp->t_bgwait);
1119 	cv_broadcast(&tp->t_dcdwait);
1120 
1121 	tp->t_flags |= TF_GONE;
1122 	tty_rel_free(tp);
1123 }
1124 
1125 /*
1126  * Exposing information about current TTY's through sysctl
1127  */
1128 
1129 static void
1130 tty_to_xtty(struct tty *tp, struct xtty *xt)
1131 {
1132 	tty_lock_assert(tp, MA_OWNED);
1133 
1134 	xt->xt_size = sizeof(struct xtty);
1135 	xt->xt_insize = ttyinq_getsize(&tp->t_inq);
1136 	xt->xt_incc = ttyinq_bytescanonicalized(&tp->t_inq);
1137 	xt->xt_inlc = ttyinq_bytesline(&tp->t_inq);
1138 	xt->xt_inlow = tp->t_inlow;
1139 	xt->xt_outsize = ttyoutq_getsize(&tp->t_outq);
1140 	xt->xt_outcc = ttyoutq_bytesused(&tp->t_outq);
1141 	xt->xt_outlow = tp->t_outlow;
1142 	xt->xt_column = tp->t_column;
1143 	xt->xt_pgid = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
1144 	xt->xt_sid = tp->t_session ? tp->t_session->s_sid : 0;
1145 	xt->xt_flags = tp->t_flags;
1146 	xt->xt_dev = tp->t_dev ? dev2udev(tp->t_dev) : NODEV;
1147 }
1148 
1149 static int
1150 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
1151 {
1152 	unsigned long lsize;
1153 	struct xtty *xtlist, *xt;
1154 	struct tty *tp;
1155 	int error;
1156 
1157 	sx_slock(&tty_list_sx);
1158 	lsize = tty_list_count * sizeof(struct xtty);
1159 	if (lsize == 0) {
1160 		sx_sunlock(&tty_list_sx);
1161 		return (0);
1162 	}
1163 
1164 	xtlist = xt = malloc(lsize, M_TTY, M_WAITOK);
1165 
1166 	TAILQ_FOREACH(tp, &tty_list, t_list) {
1167 		tty_lock(tp);
1168 		tty_to_xtty(tp, xt);
1169 		tty_unlock(tp);
1170 		xt++;
1171 	}
1172 	sx_sunlock(&tty_list_sx);
1173 
1174 	error = SYSCTL_OUT(req, xtlist, lsize);
1175 	free(xtlist, M_TTY);
1176 	return (error);
1177 }
1178 
1179 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
1180 	0, 0, sysctl_kern_ttys, "S,xtty", "List of TTYs");
1181 
1182 /*
1183  * Device node creation. Device has been set up, now we can expose it to
1184  * the user.
1185  */
1186 
1187 int
1188 tty_makedevf(struct tty *tp, struct ucred *cred, int flags,
1189     const char *fmt, ...)
1190 {
1191 	va_list ap;
1192 	struct cdev *dev, *init, *lock, *cua, *cinit, *clock;
1193 	const char *prefix = "tty";
1194 	char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
1195 	uid_t uid;
1196 	gid_t gid;
1197 	mode_t mode;
1198 	int error;
1199 
1200 	/* Remove "tty" prefix from devices like PTY's. */
1201 	if (tp->t_flags & TF_NOPREFIX)
1202 		prefix = "";
1203 
1204 	va_start(ap, fmt);
1205 	vsnrprintf(name, sizeof name, 32, fmt, ap);
1206 	va_end(ap);
1207 
1208 	if (cred == NULL) {
1209 		/* System device. */
1210 		uid = UID_ROOT;
1211 		gid = GID_WHEEL;
1212 		mode = S_IRUSR|S_IWUSR;
1213 	} else {
1214 		/* User device. */
1215 		uid = cred->cr_ruid;
1216 		gid = GID_TTY;
1217 		mode = S_IRUSR|S_IWUSR|S_IWGRP;
1218 	}
1219 
1220 	flags = flags & TTYMK_CLONING ? MAKEDEV_REF : 0;
1221 	flags |= MAKEDEV_CHECKNAME;
1222 
1223 	/* Master call-in device. */
1224 	error = make_dev_p(flags, &dev, &ttydev_cdevsw, cred, uid, gid, mode,
1225 	    "%s%s", prefix, name);
1226 	if (error)
1227 		return (error);
1228 	dev->si_drv1 = tp;
1229 	wakeup(&dev->si_drv1);
1230 	tp->t_dev = dev;
1231 
1232 	init = lock = cua = cinit = clock = NULL;
1233 
1234 	/* Slave call-in devices. */
1235 	if (tp->t_flags & TF_INITLOCK) {
1236 		error = make_dev_p(flags, &init, &ttyil_cdevsw, cred, uid,
1237 		    gid, mode, "%s%s.init", prefix, name);
1238 		if (error)
1239 			goto fail;
1240 		dev_depends(dev, init);
1241 		dev2unit(init) = TTYUNIT_INIT;
1242 		init->si_drv1 = tp;
1243 		wakeup(&init->si_drv1);
1244 		init->si_drv2 = &tp->t_termios_init_in;
1245 
1246 		error = make_dev_p(flags, &lock, &ttyil_cdevsw, cred, uid,
1247 		    gid, mode, "%s%s.lock", prefix, name);
1248 		if (error)
1249 			goto fail;
1250 		dev_depends(dev, lock);
1251 		dev2unit(lock) = TTYUNIT_LOCK;
1252 		lock->si_drv1 = tp;
1253 		wakeup(&lock->si_drv1);
1254 		lock->si_drv2 = &tp->t_termios_lock_in;
1255 	}
1256 
1257 	/* Call-out devices. */
1258 	if (tp->t_flags & TF_CALLOUT) {
1259 		error = make_dev_p(flags, &cua, &ttydev_cdevsw, cred,
1260 		    UID_UUCP, GID_DIALER, 0660, "cua%s", name);
1261 		if (error)
1262 			goto fail;
1263 		dev_depends(dev, cua);
1264 		dev2unit(cua) = TTYUNIT_CALLOUT;
1265 		cua->si_drv1 = tp;
1266 		wakeup(&cua->si_drv1);
1267 
1268 		/* Slave call-out devices. */
1269 		if (tp->t_flags & TF_INITLOCK) {
1270 			error = make_dev_p(flags, &cinit, &ttyil_cdevsw, cred,
1271 			    UID_UUCP, GID_DIALER, 0660, "cua%s.init", name);
1272 			if (error)
1273 				goto fail;
1274 			dev_depends(dev, cinit);
1275 			dev2unit(cinit) = TTYUNIT_CALLOUT | TTYUNIT_INIT;
1276 			cinit->si_drv1 = tp;
1277 			wakeup(&cinit->si_drv1);
1278 			cinit->si_drv2 = &tp->t_termios_init_out;
1279 
1280 			error = make_dev_p(flags, &clock, &ttyil_cdevsw, cred,
1281 			    UID_UUCP, GID_DIALER, 0660, "cua%s.lock", name);
1282 			if (error)
1283 				goto fail;
1284 			dev_depends(dev, clock);
1285 			dev2unit(clock) = TTYUNIT_CALLOUT | TTYUNIT_LOCK;
1286 			clock->si_drv1 = tp;
1287 			wakeup(&clock->si_drv1);
1288 			clock->si_drv2 = &tp->t_termios_lock_out;
1289 		}
1290 	}
1291 
1292 	sx_xlock(&tty_list_sx);
1293 	TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
1294 	tty_list_count++;
1295 	sx_xunlock(&tty_list_sx);
1296 
1297 	return (0);
1298 
1299 fail:
1300 	destroy_dev(dev);
1301 	if (init)
1302 		destroy_dev(init);
1303 	if (lock)
1304 		destroy_dev(lock);
1305 	if (cinit)
1306 		destroy_dev(cinit);
1307 	if (clock)
1308 		destroy_dev(clock);
1309 
1310 	return (error);
1311 }
1312 
1313 /*
1314  * Signalling processes.
1315  */
1316 
1317 void
1318 tty_signal_sessleader(struct tty *tp, int sig)
1319 {
1320 	struct proc *p;
1321 
1322 	tty_lock_assert(tp, MA_OWNED);
1323 	MPASS(sig >= 1 && sig < NSIG);
1324 
1325 	/* Make signals start output again. */
1326 	tp->t_flags &= ~TF_STOPPED;
1327 
1328 	if (tp->t_session != NULL && tp->t_session->s_leader != NULL) {
1329 		p = tp->t_session->s_leader;
1330 		PROC_LOCK(p);
1331 		kern_psignal(p, sig);
1332 		PROC_UNLOCK(p);
1333 	}
1334 }
1335 
1336 void
1337 tty_signal_pgrp(struct tty *tp, int sig)
1338 {
1339 	ksiginfo_t ksi;
1340 
1341 	tty_lock_assert(tp, MA_OWNED);
1342 	MPASS(sig >= 1 && sig < NSIG);
1343 
1344 	/* Make signals start output again. */
1345 	tp->t_flags &= ~TF_STOPPED;
1346 
1347 	if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
1348 		tty_info(tp);
1349 	if (tp->t_pgrp != NULL) {
1350 		ksiginfo_init(&ksi);
1351 		ksi.ksi_signo = sig;
1352 		ksi.ksi_code = SI_KERNEL;
1353 		PGRP_LOCK(tp->t_pgrp);
1354 		pgsignal(tp->t_pgrp, sig, 1, &ksi);
1355 		PGRP_UNLOCK(tp->t_pgrp);
1356 	}
1357 }
1358 
1359 void
1360 tty_wakeup(struct tty *tp, int flags)
1361 {
1362 	if (tp->t_flags & TF_ASYNC && tp->t_sigio != NULL)
1363 		pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
1364 
1365 	if (flags & FWRITE) {
1366 		cv_broadcast(&tp->t_outwait);
1367 		selwakeup(&tp->t_outpoll);
1368 		KNOTE_LOCKED(&tp->t_outpoll.si_note, 0);
1369 	}
1370 	if (flags & FREAD) {
1371 		cv_broadcast(&tp->t_inwait);
1372 		selwakeup(&tp->t_inpoll);
1373 		KNOTE_LOCKED(&tp->t_inpoll.si_note, 0);
1374 	}
1375 }
1376 
1377 int
1378 tty_wait(struct tty *tp, struct cv *cv)
1379 {
1380 	int error;
1381 	int revokecnt = tp->t_revokecnt;
1382 
1383 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1384 	MPASS(!tty_gone(tp));
1385 
1386 	error = cv_wait_sig(cv, tp->t_mtx);
1387 
1388 	/* Bail out when the device slipped away. */
1389 	if (tty_gone(tp))
1390 		return (ENXIO);
1391 
1392 	/* Restart the system call when we may have been revoked. */
1393 	if (tp->t_revokecnt != revokecnt)
1394 		return (ERESTART);
1395 
1396 	return (error);
1397 }
1398 
1399 int
1400 tty_timedwait(struct tty *tp, struct cv *cv, int hz)
1401 {
1402 	int error;
1403 	int revokecnt = tp->t_revokecnt;
1404 
1405 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1406 	MPASS(!tty_gone(tp));
1407 
1408 	error = cv_timedwait_sig(cv, tp->t_mtx, hz);
1409 
1410 	/* Bail out when the device slipped away. */
1411 	if (tty_gone(tp))
1412 		return (ENXIO);
1413 
1414 	/* Restart the system call when we may have been revoked. */
1415 	if (tp->t_revokecnt != revokecnt)
1416 		return (ERESTART);
1417 
1418 	return (error);
1419 }
1420 
1421 void
1422 tty_flush(struct tty *tp, int flags)
1423 {
1424 	if (flags & FWRITE) {
1425 		tp->t_flags &= ~TF_HIWAT_OUT;
1426 		ttyoutq_flush(&tp->t_outq);
1427 		tty_wakeup(tp, FWRITE);
1428 		ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
1429 	}
1430 	if (flags & FREAD) {
1431 		tty_hiwat_in_unblock(tp);
1432 		ttyinq_flush(&tp->t_inq);
1433 		ttydevsw_inwakeup(tp);
1434 		ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
1435 	}
1436 }
1437 
1438 void
1439 tty_set_winsize(struct tty *tp, const struct winsize *wsz)
1440 {
1441 
1442 	if (memcmp(&tp->t_winsize, wsz, sizeof(*wsz)) == 0)
1443 		return;
1444 	tp->t_winsize = *wsz;
1445 	tty_signal_pgrp(tp, SIGWINCH);
1446 }
1447 
1448 static int
1449 tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, int fflag,
1450     struct thread *td)
1451 {
1452 	int error;
1453 
1454 	switch (cmd) {
1455 	/*
1456 	 * Modem commands.
1457 	 * The SER_* and TIOCM_* flags are the same, but one bit
1458 	 * shifted. I don't know why.
1459 	 */
1460 	case TIOCSDTR:
1461 		ttydevsw_modem(tp, SER_DTR, 0);
1462 		return (0);
1463 	case TIOCCDTR:
1464 		ttydevsw_modem(tp, 0, SER_DTR);
1465 		return (0);
1466 	case TIOCMSET: {
1467 		int bits = *(int *)data;
1468 		ttydevsw_modem(tp,
1469 		    (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1,
1470 		    ((~bits) & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1471 		return (0);
1472 	}
1473 	case TIOCMBIS: {
1474 		int bits = *(int *)data;
1475 		ttydevsw_modem(tp, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1, 0);
1476 		return (0);
1477 	}
1478 	case TIOCMBIC: {
1479 		int bits = *(int *)data;
1480 		ttydevsw_modem(tp, 0, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1481 		return (0);
1482 	}
1483 	case TIOCMGET:
1484 		*(int *)data = TIOCM_LE + (ttydevsw_modem(tp, 0, 0) << 1);
1485 		return (0);
1486 
1487 	case FIOASYNC:
1488 		if (*(int *)data)
1489 			tp->t_flags |= TF_ASYNC;
1490 		else
1491 			tp->t_flags &= ~TF_ASYNC;
1492 		return (0);
1493 	case FIONBIO:
1494 		/* This device supports non-blocking operation. */
1495 		return (0);
1496 	case FIONREAD:
1497 		*(int *)data = ttyinq_bytescanonicalized(&tp->t_inq);
1498 		return (0);
1499 	case FIONWRITE:
1500 	case TIOCOUTQ:
1501 		*(int *)data = ttyoutq_bytesused(&tp->t_outq);
1502 		return (0);
1503 	case FIOSETOWN:
1504 		if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1505 			/* Not allowed to set ownership. */
1506 			return (ENOTTY);
1507 
1508 		/* Temporarily unlock the TTY to set ownership. */
1509 		tty_unlock(tp);
1510 		error = fsetown(*(int *)data, &tp->t_sigio);
1511 		tty_lock(tp);
1512 		return (error);
1513 	case FIOGETOWN:
1514 		if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1515 			/* Not allowed to set ownership. */
1516 			return (ENOTTY);
1517 
1518 		/* Get ownership. */
1519 		*(int *)data = fgetown(&tp->t_sigio);
1520 		return (0);
1521 	case TIOCGETA:
1522 		/* Obtain terminal flags through tcgetattr(). */
1523 		*(struct termios*)data = tp->t_termios;
1524 		return (0);
1525 	case TIOCSETA:
1526 	case TIOCSETAW:
1527 	case TIOCSETAF: {
1528 		struct termios *t = data;
1529 
1530 		/*
1531 		 * Who makes up these funny rules? According to POSIX,
1532 		 * input baud rate is set equal to the output baud rate
1533 		 * when zero.
1534 		 */
1535 		if (t->c_ispeed == 0)
1536 			t->c_ispeed = t->c_ospeed;
1537 
1538 		/* Discard any unsupported bits. */
1539 		t->c_iflag &= TTYSUP_IFLAG;
1540 		t->c_oflag &= TTYSUP_OFLAG;
1541 		t->c_lflag &= TTYSUP_LFLAG;
1542 		t->c_cflag &= TTYSUP_CFLAG;
1543 
1544 		/* Set terminal flags through tcsetattr(). */
1545 		if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
1546 			error = tty_drain(tp, 0);
1547 			if (error)
1548 				return (error);
1549 			if (cmd == TIOCSETAF)
1550 				tty_flush(tp, FREAD);
1551 		}
1552 
1553 		/*
1554 		 * Only call param() when the flags really change.
1555 		 */
1556 		if ((t->c_cflag & CIGNORE) == 0 &&
1557 		    (tp->t_termios.c_cflag != t->c_cflag ||
1558 		    ((tp->t_termios.c_iflag ^ t->c_iflag) &
1559 		    (IXON|IXOFF|IXANY)) ||
1560 		    tp->t_termios.c_ispeed != t->c_ispeed ||
1561 		    tp->t_termios.c_ospeed != t->c_ospeed)) {
1562 			error = ttydevsw_param(tp, t);
1563 			if (error)
1564 				return (error);
1565 
1566 			/* XXX: CLOCAL? */
1567 
1568 			tp->t_termios.c_cflag = t->c_cflag & ~CIGNORE;
1569 			tp->t_termios.c_ispeed = t->c_ispeed;
1570 			tp->t_termios.c_ospeed = t->c_ospeed;
1571 
1572 			/* Baud rate has changed - update watermarks. */
1573 			tty_watermarks(tp);
1574 		}
1575 
1576 		/* Copy new non-device driver parameters. */
1577 		tp->t_termios.c_iflag = t->c_iflag;
1578 		tp->t_termios.c_oflag = t->c_oflag;
1579 		tp->t_termios.c_lflag = t->c_lflag;
1580 		memcpy(&tp->t_termios.c_cc, t->c_cc, sizeof t->c_cc);
1581 
1582 		ttydisc_optimize(tp);
1583 
1584 		if ((t->c_lflag & ICANON) == 0) {
1585 			/*
1586 			 * When in non-canonical mode, wake up all
1587 			 * readers. Canonicalize any partial input. VMIN
1588 			 * and VTIME could also be adjusted.
1589 			 */
1590 			ttyinq_canonicalize(&tp->t_inq);
1591 			tty_wakeup(tp, FREAD);
1592 		}
1593 
1594 		/*
1595 		 * For packet mode: notify the PTY consumer that VSTOP
1596 		 * and VSTART may have been changed.
1597 		 */
1598 		if (tp->t_termios.c_iflag & IXON &&
1599 		    tp->t_termios.c_cc[VSTOP] == CTRL('S') &&
1600 		    tp->t_termios.c_cc[VSTART] == CTRL('Q'))
1601 			ttydevsw_pktnotify(tp, TIOCPKT_DOSTOP);
1602 		else
1603 			ttydevsw_pktnotify(tp, TIOCPKT_NOSTOP);
1604 		return (0);
1605 	}
1606 	case TIOCGETD:
1607 		/* For compatibility - we only support TTYDISC. */
1608 		*(int *)data = TTYDISC;
1609 		return (0);
1610 	case TIOCGPGRP:
1611 		if (!tty_is_ctty(tp, td->td_proc))
1612 			return (ENOTTY);
1613 
1614 		if (tp->t_pgrp != NULL)
1615 			*(int *)data = tp->t_pgrp->pg_id;
1616 		else
1617 			*(int *)data = NO_PID;
1618 		return (0);
1619 	case TIOCGSID:
1620 		if (!tty_is_ctty(tp, td->td_proc))
1621 			return (ENOTTY);
1622 
1623 		MPASS(tp->t_session);
1624 		*(int *)data = tp->t_session->s_sid;
1625 		return (0);
1626 	case TIOCSCTTY: {
1627 		struct proc *p = td->td_proc;
1628 
1629 		/* XXX: This looks awful. */
1630 		tty_unlock(tp);
1631 		sx_xlock(&proctree_lock);
1632 		tty_lock(tp);
1633 
1634 		if (!SESS_LEADER(p)) {
1635 			/* Only the session leader may do this. */
1636 			sx_xunlock(&proctree_lock);
1637 			return (EPERM);
1638 		}
1639 
1640 		if (tp->t_session != NULL && tp->t_session == p->p_session) {
1641 			/* This is already our controlling TTY. */
1642 			sx_xunlock(&proctree_lock);
1643 			return (0);
1644 		}
1645 
1646 		if (p->p_session->s_ttyp != NULL ||
1647 		    (tp->t_session != NULL && tp->t_session->s_ttyvp != NULL &&
1648 		    tp->t_session->s_ttyvp->v_type != VBAD)) {
1649 			/*
1650 			 * There is already a relation between a TTY and
1651 			 * a session, or the caller is not the session
1652 			 * leader.
1653 			 *
1654 			 * Allow the TTY to be stolen when the vnode is
1655 			 * invalid, but the reference to the TTY is
1656 			 * still active.  This allows immediate reuse of
1657 			 * TTYs of which the session leader has been
1658 			 * killed or the TTY revoked.
1659 			 */
1660 			sx_xunlock(&proctree_lock);
1661 			return (EPERM);
1662 		}
1663 
1664 		/* Connect the session to the TTY. */
1665 		tp->t_session = p->p_session;
1666 		tp->t_session->s_ttyp = tp;
1667 		tp->t_sessioncnt++;
1668 		sx_xunlock(&proctree_lock);
1669 
1670 		/* Assign foreground process group. */
1671 		tp->t_pgrp = p->p_pgrp;
1672 		PROC_LOCK(p);
1673 		p->p_flag |= P_CONTROLT;
1674 		PROC_UNLOCK(p);
1675 
1676 		return (0);
1677 	}
1678 	case TIOCSPGRP: {
1679 		struct pgrp *pg;
1680 
1681 		/*
1682 		 * XXX: Temporarily unlock the TTY to locate the process
1683 		 * group. This code would be lot nicer if we would ever
1684 		 * decompose proctree_lock.
1685 		 */
1686 		tty_unlock(tp);
1687 		sx_slock(&proctree_lock);
1688 		pg = pgfind(*(int *)data);
1689 		if (pg != NULL)
1690 			PGRP_UNLOCK(pg);
1691 		if (pg == NULL || pg->pg_session != td->td_proc->p_session) {
1692 			sx_sunlock(&proctree_lock);
1693 			tty_lock(tp);
1694 			return (EPERM);
1695 		}
1696 		tty_lock(tp);
1697 
1698 		/*
1699 		 * Determine if this TTY is the controlling TTY after
1700 		 * relocking the TTY.
1701 		 */
1702 		if (!tty_is_ctty(tp, td->td_proc)) {
1703 			sx_sunlock(&proctree_lock);
1704 			return (ENOTTY);
1705 		}
1706 		tp->t_pgrp = pg;
1707 		sx_sunlock(&proctree_lock);
1708 
1709 		/* Wake up the background process groups. */
1710 		cv_broadcast(&tp->t_bgwait);
1711 		return (0);
1712 	}
1713 	case TIOCFLUSH: {
1714 		int flags = *(int *)data;
1715 
1716 		if (flags == 0)
1717 			flags = (FREAD|FWRITE);
1718 		else
1719 			flags &= (FREAD|FWRITE);
1720 		tty_flush(tp, flags);
1721 		return (0);
1722 	}
1723 	case TIOCDRAIN:
1724 		/* Drain TTY output. */
1725 		return tty_drain(tp, 0);
1726 	case TIOCCONS:
1727 		/* Set terminal as console TTY. */
1728 		if (*(int *)data) {
1729 			error = priv_check(td, PRIV_TTY_CONSOLE);
1730 			if (error)
1731 				return (error);
1732 
1733 			/*
1734 			 * XXX: constty should really need to be locked!
1735 			 * XXX: allow disconnected constty's to be stolen!
1736 			 */
1737 
1738 			if (constty == tp)
1739 				return (0);
1740 			if (constty != NULL)
1741 				return (EBUSY);
1742 
1743 			tty_unlock(tp);
1744 			constty_set(tp);
1745 			tty_lock(tp);
1746 		} else if (constty == tp) {
1747 			constty_clear();
1748 		}
1749 		return (0);
1750 	case TIOCGWINSZ:
1751 		/* Obtain window size. */
1752 		*(struct winsize*)data = tp->t_winsize;
1753 		return (0);
1754 	case TIOCSWINSZ:
1755 		/* Set window size. */
1756 		tty_set_winsize(tp, data);
1757 		return (0);
1758 	case TIOCEXCL:
1759 		tp->t_flags |= TF_EXCLUDE;
1760 		return (0);
1761 	case TIOCNXCL:
1762 		tp->t_flags &= ~TF_EXCLUDE;
1763 		return (0);
1764 	case TIOCSTOP:
1765 		tp->t_flags |= TF_STOPPED;
1766 		ttydevsw_pktnotify(tp, TIOCPKT_STOP);
1767 		return (0);
1768 	case TIOCSTART:
1769 		tp->t_flags &= ~TF_STOPPED;
1770 		ttydevsw_outwakeup(tp);
1771 		ttydevsw_pktnotify(tp, TIOCPKT_START);
1772 		return (0);
1773 	case TIOCSTAT:
1774 		tty_info(tp);
1775 		return (0);
1776 	case TIOCSTI:
1777 		if ((fflag & FREAD) == 0 && priv_check(td, PRIV_TTY_STI))
1778 			return (EPERM);
1779 		if (!tty_is_ctty(tp, td->td_proc) &&
1780 		    priv_check(td, PRIV_TTY_STI))
1781 			return (EACCES);
1782 		ttydisc_rint(tp, *(char *)data, 0);
1783 		ttydisc_rint_done(tp);
1784 		return (0);
1785 	}
1786 
1787 #ifdef COMPAT_43TTY
1788 	return tty_ioctl_compat(tp, cmd, data, fflag, td);
1789 #else /* !COMPAT_43TTY */
1790 	return (ENOIOCTL);
1791 #endif /* COMPAT_43TTY */
1792 }
1793 
1794 int
1795 tty_ioctl(struct tty *tp, u_long cmd, void *data, int fflag, struct thread *td)
1796 {
1797 	int error;
1798 
1799 	tty_lock_assert(tp, MA_OWNED);
1800 
1801 	if (tty_gone(tp))
1802 		return (ENXIO);
1803 
1804 	error = ttydevsw_ioctl(tp, cmd, data, td);
1805 	if (error == ENOIOCTL)
1806 		error = tty_generic_ioctl(tp, cmd, data, fflag, td);
1807 
1808 	return (error);
1809 }
1810 
1811 dev_t
1812 tty_udev(struct tty *tp)
1813 {
1814 	if (tp->t_dev)
1815 		return dev2udev(tp->t_dev);
1816 	else
1817 		return NODEV;
1818 }
1819 
1820 int
1821 tty_checkoutq(struct tty *tp)
1822 {
1823 
1824 	/* 256 bytes should be enough to print a log message. */
1825 	return (ttyoutq_bytesleft(&tp->t_outq) >= 256);
1826 }
1827 
1828 void
1829 tty_hiwat_in_block(struct tty *tp)
1830 {
1831 
1832 	if ((tp->t_flags & TF_HIWAT_IN) == 0 &&
1833 	    tp->t_termios.c_iflag & IXOFF &&
1834 	    tp->t_termios.c_cc[VSTOP] != _POSIX_VDISABLE) {
1835 		/*
1836 		 * Input flow control. Only enter the high watermark when we
1837 		 * can successfully store the VSTOP character.
1838 		 */
1839 		if (ttyoutq_write_nofrag(&tp->t_outq,
1840 		    &tp->t_termios.c_cc[VSTOP], 1) == 0)
1841 			tp->t_flags |= TF_HIWAT_IN;
1842 	} else {
1843 		/* No input flow control. */
1844 		tp->t_flags |= TF_HIWAT_IN;
1845 	}
1846 }
1847 
1848 void
1849 tty_hiwat_in_unblock(struct tty *tp)
1850 {
1851 
1852 	if (tp->t_flags & TF_HIWAT_IN &&
1853 	    tp->t_termios.c_iflag & IXOFF &&
1854 	    tp->t_termios.c_cc[VSTART] != _POSIX_VDISABLE) {
1855 		/*
1856 		 * Input flow control. Only leave the high watermark when we
1857 		 * can successfully store the VSTART character.
1858 		 */
1859 		if (ttyoutq_write_nofrag(&tp->t_outq,
1860 		    &tp->t_termios.c_cc[VSTART], 1) == 0)
1861 			tp->t_flags &= ~TF_HIWAT_IN;
1862 	} else {
1863 		/* No input flow control. */
1864 		tp->t_flags &= ~TF_HIWAT_IN;
1865 	}
1866 
1867 	if (!tty_gone(tp))
1868 		ttydevsw_inwakeup(tp);
1869 }
1870 
1871 /*
1872  * TTY hooks interface.
1873  */
1874 
1875 static int
1876 ttyhook_defrint(struct tty *tp, char c, int flags)
1877 {
1878 
1879 	if (ttyhook_rint_bypass(tp, &c, 1) != 1)
1880 		return (-1);
1881 
1882 	return (0);
1883 }
1884 
1885 int
1886 ttyhook_register(struct tty **rtp, struct proc *p, int fd,
1887     struct ttyhook *th, void *softc)
1888 {
1889 	struct tty *tp;
1890 	struct file *fp;
1891 	struct cdev *dev;
1892 	struct cdevsw *cdp;
1893 	struct filedesc *fdp;
1894 	cap_rights_t rights;
1895 	int error, ref;
1896 
1897 	/* Validate the file descriptor. */
1898 	fdp = p->p_fd;
1899 	error = fget_unlocked(fdp, fd, cap_rights_init(&rights, CAP_TTYHOOK),
1900 	    &fp, NULL);
1901 	if (error != 0)
1902 		return (error);
1903 	if (fp->f_ops == &badfileops) {
1904 		error = EBADF;
1905 		goto done1;
1906 	}
1907 
1908 	/*
1909 	 * Make sure the vnode is bound to a character device.
1910 	 * Unlocked check for the vnode type is ok there, because we
1911 	 * only shall prevent calling devvn_refthread on the file that
1912 	 * never has been opened over a character device.
1913 	 */
1914 	if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR) {
1915 		error = EINVAL;
1916 		goto done1;
1917 	}
1918 
1919 	/* Make sure it is a TTY. */
1920 	cdp = devvn_refthread(fp->f_vnode, &dev, &ref);
1921 	if (cdp == NULL) {
1922 		error = ENXIO;
1923 		goto done1;
1924 	}
1925 	if (dev != fp->f_data) {
1926 		error = ENXIO;
1927 		goto done2;
1928 	}
1929 	if (cdp != &ttydev_cdevsw) {
1930 		error = ENOTTY;
1931 		goto done2;
1932 	}
1933 	tp = dev->si_drv1;
1934 
1935 	/* Try to attach the hook to the TTY. */
1936 	error = EBUSY;
1937 	tty_lock(tp);
1938 	MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
1939 	if (tp->t_flags & TF_HOOK)
1940 		goto done3;
1941 
1942 	tp->t_flags |= TF_HOOK;
1943 	tp->t_hook = th;
1944 	tp->t_hooksoftc = softc;
1945 	*rtp = tp;
1946 	error = 0;
1947 
1948 	/* Maybe we can switch into bypass mode now. */
1949 	ttydisc_optimize(tp);
1950 
1951 	/* Silently convert rint() calls to rint_bypass() when possible. */
1952 	if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
1953 		th->th_rint = ttyhook_defrint;
1954 
1955 done3:	tty_unlock(tp);
1956 done2:	dev_relthread(dev, ref);
1957 done1:	fdrop(fp, curthread);
1958 	return (error);
1959 }
1960 
1961 void
1962 ttyhook_unregister(struct tty *tp)
1963 {
1964 
1965 	tty_lock_assert(tp, MA_OWNED);
1966 	MPASS(tp->t_flags & TF_HOOK);
1967 
1968 	/* Disconnect the hook. */
1969 	tp->t_flags &= ~TF_HOOK;
1970 	tp->t_hook = NULL;
1971 
1972 	/* Maybe we need to leave bypass mode. */
1973 	ttydisc_optimize(tp);
1974 
1975 	/* Maybe deallocate the TTY as well. */
1976 	tty_rel_free(tp);
1977 }
1978 
1979 /*
1980  * /dev/console handling.
1981  */
1982 
1983 static int
1984 ttyconsdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
1985 {
1986 	struct tty *tp;
1987 
1988 	/* System has no console device. */
1989 	if (dev_console_filename == NULL)
1990 		return (ENXIO);
1991 
1992 	/* Look up corresponding TTY by device name. */
1993 	sx_slock(&tty_list_sx);
1994 	TAILQ_FOREACH(tp, &tty_list, t_list) {
1995 		if (strcmp(dev_console_filename, tty_devname(tp)) == 0) {
1996 			dev_console->si_drv1 = tp;
1997 			break;
1998 		}
1999 	}
2000 	sx_sunlock(&tty_list_sx);
2001 
2002 	/* System console has no TTY associated. */
2003 	if (dev_console->si_drv1 == NULL)
2004 		return (ENXIO);
2005 
2006 	return (ttydev_open(dev, oflags, devtype, td));
2007 }
2008 
2009 static int
2010 ttyconsdev_write(struct cdev *dev, struct uio *uio, int ioflag)
2011 {
2012 
2013 	log_console(uio);
2014 
2015 	return (ttydev_write(dev, uio, ioflag));
2016 }
2017 
2018 /*
2019  * /dev/console is a little different than normal TTY's.  When opened,
2020  * it determines which TTY to use.  When data gets written to it, it
2021  * will be logged in the kernel message buffer.
2022  */
2023 static struct cdevsw ttyconsdev_cdevsw = {
2024 	.d_version	= D_VERSION,
2025 	.d_open		= ttyconsdev_open,
2026 	.d_close	= ttydev_close,
2027 	.d_read		= ttydev_read,
2028 	.d_write	= ttyconsdev_write,
2029 	.d_ioctl	= ttydev_ioctl,
2030 	.d_kqfilter	= ttydev_kqfilter,
2031 	.d_poll		= ttydev_poll,
2032 	.d_mmap		= ttydev_mmap,
2033 	.d_name		= "ttyconsdev",
2034 	.d_flags	= D_TTY,
2035 };
2036 
2037 static void
2038 ttyconsdev_init(void *unused)
2039 {
2040 
2041 	dev_console = make_dev_credf(MAKEDEV_ETERNAL, &ttyconsdev_cdevsw, 0,
2042 	    NULL, UID_ROOT, GID_WHEEL, 0600, "console");
2043 }
2044 
2045 SYSINIT(tty, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyconsdev_init, NULL);
2046 
2047 void
2048 ttyconsdev_select(const char *name)
2049 {
2050 
2051 	dev_console_filename = name;
2052 }
2053 
2054 /*
2055  * Debugging routines.
2056  */
2057 
2058 #include "opt_ddb.h"
2059 #ifdef DDB
2060 #include <ddb/ddb.h>
2061 #include <ddb/db_sym.h>
2062 
2063 static struct {
2064 	int flag;
2065 	char val;
2066 } ttystates[] = {
2067 #if 0
2068 	{ TF_NOPREFIX,		'N' },
2069 #endif
2070 	{ TF_INITLOCK,		'I' },
2071 	{ TF_CALLOUT,		'C' },
2072 
2073 	/* Keep these together -> 'Oi' and 'Oo'. */
2074 	{ TF_OPENED,		'O' },
2075 	{ TF_OPENED_IN,		'i' },
2076 	{ TF_OPENED_OUT,	'o' },
2077 	{ TF_OPENED_CONS,	'c' },
2078 
2079 	{ TF_GONE,		'G' },
2080 	{ TF_OPENCLOSE,		'B' },
2081 	{ TF_ASYNC,		'Y' },
2082 	{ TF_LITERAL,		'L' },
2083 
2084 	/* Keep these together -> 'Hi' and 'Ho'. */
2085 	{ TF_HIWAT,		'H' },
2086 	{ TF_HIWAT_IN,		'i' },
2087 	{ TF_HIWAT_OUT,		'o' },
2088 
2089 	{ TF_STOPPED,		'S' },
2090 	{ TF_EXCLUDE,		'X' },
2091 	{ TF_BYPASS,		'l' },
2092 	{ TF_ZOMBIE,		'Z' },
2093 	{ TF_HOOK,		's' },
2094 
2095 	/* Keep these together -> 'bi' and 'bo'. */
2096 	{ TF_BUSY,		'b' },
2097 	{ TF_BUSY_IN,		'i' },
2098 	{ TF_BUSY_OUT,		'o' },
2099 
2100 	{ 0,			'\0'},
2101 };
2102 
2103 #define	TTY_FLAG_BITS \
2104 	"\20\1NOPREFIX\2INITLOCK\3CALLOUT\4OPENED_IN\5OPENED_OUT\6GONE" \
2105 	"\7OPENCLOSE\10ASYNC\11LITERAL\12HIWAT_IN\13HIWAT_OUT\14STOPPED" \
2106 	"\15EXCLUDE\16BYPASS\17ZOMBIE\20HOOK"
2107 
2108 #define DB_PRINTSYM(name, addr) \
2109 	db_printf("%s  " #name ": ", sep); \
2110 	db_printsym((db_addr_t) addr, DB_STGY_ANY); \
2111 	db_printf("\n");
2112 
2113 static void
2114 _db_show_devsw(const char *sep, const struct ttydevsw *tsw)
2115 {
2116 	db_printf("%sdevsw: ", sep);
2117 	db_printsym((db_addr_t)tsw, DB_STGY_ANY);
2118 	db_printf(" (%p)\n", tsw);
2119 	DB_PRINTSYM(open, tsw->tsw_open);
2120 	DB_PRINTSYM(close, tsw->tsw_close);
2121 	DB_PRINTSYM(outwakeup, tsw->tsw_outwakeup);
2122 	DB_PRINTSYM(inwakeup, tsw->tsw_inwakeup);
2123 	DB_PRINTSYM(ioctl, tsw->tsw_ioctl);
2124 	DB_PRINTSYM(param, tsw->tsw_param);
2125 	DB_PRINTSYM(modem, tsw->tsw_modem);
2126 	DB_PRINTSYM(mmap, tsw->tsw_mmap);
2127 	DB_PRINTSYM(pktnotify, tsw->tsw_pktnotify);
2128 	DB_PRINTSYM(free, tsw->tsw_free);
2129 }
2130 static void
2131 _db_show_hooks(const char *sep, const struct ttyhook *th)
2132 {
2133 	db_printf("%shook: ", sep);
2134 	db_printsym((db_addr_t)th, DB_STGY_ANY);
2135 	db_printf(" (%p)\n", th);
2136 	if (th == NULL)
2137 		return;
2138 	DB_PRINTSYM(rint, th->th_rint);
2139 	DB_PRINTSYM(rint_bypass, th->th_rint_bypass);
2140 	DB_PRINTSYM(rint_done, th->th_rint_done);
2141 	DB_PRINTSYM(rint_poll, th->th_rint_poll);
2142 	DB_PRINTSYM(getc_inject, th->th_getc_inject);
2143 	DB_PRINTSYM(getc_capture, th->th_getc_capture);
2144 	DB_PRINTSYM(getc_poll, th->th_getc_poll);
2145 	DB_PRINTSYM(close, th->th_close);
2146 }
2147 
2148 static void
2149 _db_show_termios(const char *name, const struct termios *t)
2150 {
2151 
2152 	db_printf("%s: iflag 0x%x oflag 0x%x cflag 0x%x "
2153 	    "lflag 0x%x ispeed %u ospeed %u\n", name,
2154 	    t->c_iflag, t->c_oflag, t->c_cflag, t->c_lflag,
2155 	    t->c_ispeed, t->c_ospeed);
2156 }
2157 
2158 /* DDB command to show TTY statistics. */
2159 DB_SHOW_COMMAND(tty, db_show_tty)
2160 {
2161 	struct tty *tp;
2162 
2163 	if (!have_addr) {
2164 		db_printf("usage: show tty <addr>\n");
2165 		return;
2166 	}
2167 	tp = (struct tty *)addr;
2168 
2169 	db_printf("0x%p: %s\n", tp, tty_devname(tp));
2170 	db_printf("\tmtx: %p\n", tp->t_mtx);
2171 	db_printf("\tflags: %b\n", tp->t_flags, TTY_FLAG_BITS);
2172 	db_printf("\trevokecnt: %u\n", tp->t_revokecnt);
2173 
2174 	/* Buffering mechanisms. */
2175 	db_printf("\tinq: %p begin %u linestart %u reprint %u end %u "
2176 	    "nblocks %u quota %u\n", &tp->t_inq, tp->t_inq.ti_begin,
2177 	    tp->t_inq.ti_linestart, tp->t_inq.ti_reprint, tp->t_inq.ti_end,
2178 	    tp->t_inq.ti_nblocks, tp->t_inq.ti_quota);
2179 	db_printf("\toutq: %p begin %u end %u nblocks %u quota %u\n",
2180 	    &tp->t_outq, tp->t_outq.to_begin, tp->t_outq.to_end,
2181 	    tp->t_outq.to_nblocks, tp->t_outq.to_quota);
2182 	db_printf("\tinlow: %zu\n", tp->t_inlow);
2183 	db_printf("\toutlow: %zu\n", tp->t_outlow);
2184 	_db_show_termios("\ttermios", &tp->t_termios);
2185 	db_printf("\twinsize: row %u col %u xpixel %u ypixel %u\n",
2186 	    tp->t_winsize.ws_row, tp->t_winsize.ws_col,
2187 	    tp->t_winsize.ws_xpixel, tp->t_winsize.ws_ypixel);
2188 	db_printf("\tcolumn: %u\n", tp->t_column);
2189 	db_printf("\twritepos: %u\n", tp->t_writepos);
2190 	db_printf("\tcompatflags: 0x%x\n", tp->t_compatflags);
2191 
2192 	/* Init/lock-state devices. */
2193 	_db_show_termios("\ttermios_init_in", &tp->t_termios_init_in);
2194 	_db_show_termios("\ttermios_init_out", &tp->t_termios_init_out);
2195 	_db_show_termios("\ttermios_lock_in", &tp->t_termios_lock_in);
2196 	_db_show_termios("\ttermios_lock_out", &tp->t_termios_lock_out);
2197 
2198 	/* Hooks */
2199 	_db_show_devsw("\t", tp->t_devsw);
2200 	_db_show_hooks("\t", tp->t_hook);
2201 
2202 	/* Process info. */
2203 	db_printf("\tpgrp: %p gid %d jobc %d\n", tp->t_pgrp,
2204 	    tp->t_pgrp ? tp->t_pgrp->pg_id : 0,
2205 	    tp->t_pgrp ? tp->t_pgrp->pg_jobc : 0);
2206 	db_printf("\tsession: %p", tp->t_session);
2207 	if (tp->t_session != NULL)
2208 	    db_printf(" count %u leader %p tty %p sid %d login %s",
2209 		tp->t_session->s_count, tp->t_session->s_leader,
2210 		tp->t_session->s_ttyp, tp->t_session->s_sid,
2211 		tp->t_session->s_login);
2212 	db_printf("\n");
2213 	db_printf("\tsessioncnt: %u\n", tp->t_sessioncnt);
2214 	db_printf("\tdevswsoftc: %p\n", tp->t_devswsoftc);
2215 	db_printf("\thooksoftc: %p\n", tp->t_hooksoftc);
2216 	db_printf("\tdev: %p\n", tp->t_dev);
2217 }
2218 
2219 /* DDB command to list TTYs. */
2220 DB_SHOW_ALL_COMMAND(ttys, db_show_all_ttys)
2221 {
2222 	struct tty *tp;
2223 	size_t isiz, osiz;
2224 	int i, j;
2225 
2226 	/* Make the output look like `pstat -t'. */
2227 	db_printf("PTR        ");
2228 #if defined(__LP64__)
2229 	db_printf("        ");
2230 #endif
2231 	db_printf("      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   "
2232 	    "COL  SESS  PGID STATE\n");
2233 
2234 	TAILQ_FOREACH(tp, &tty_list, t_list) {
2235 		isiz = tp->t_inq.ti_nblocks * TTYINQ_DATASIZE;
2236 		osiz = tp->t_outq.to_nblocks * TTYOUTQ_DATASIZE;
2237 
2238 		db_printf("%p %10s %5zu %4u %4u %4zu %5zu %4u %4zu %5u %5d %5d ",
2239 		    tp,
2240 		    tty_devname(tp),
2241 		    isiz,
2242 		    tp->t_inq.ti_linestart - tp->t_inq.ti_begin,
2243 		    tp->t_inq.ti_end - tp->t_inq.ti_linestart,
2244 		    isiz - tp->t_inlow,
2245 		    osiz,
2246 		    tp->t_outq.to_end - tp->t_outq.to_begin,
2247 		    osiz - tp->t_outlow,
2248 		    MIN(tp->t_column, 99999),
2249 		    tp->t_session ? tp->t_session->s_sid : 0,
2250 		    tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
2251 
2252 		/* Flag bits. */
2253 		for (i = j = 0; ttystates[i].flag; i++)
2254 			if (tp->t_flags & ttystates[i].flag) {
2255 				db_printf("%c", ttystates[i].val);
2256 				j++;
2257 			}
2258 		if (j == 0)
2259 			db_printf("-");
2260 		db_printf("\n");
2261 	}
2262 }
2263 #endif /* DDB */
2264