xref: /freebsd/sys/kern/tty.c (revision 84eacaf728a102612d83861d73c3aaa353ca3dc2)
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;
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 /*
959  * TTY allocation and deallocation. TTY devices can be deallocated when
960  * the driver doesn't use it anymore, when the TTY isn't a session's
961  * controlling TTY and when the device node isn't opened through devfs.
962  */
963 
964 struct tty *
965 tty_alloc(struct ttydevsw *tsw, void *sc)
966 {
967 
968 	return (tty_alloc_mutex(tsw, sc, NULL));
969 }
970 
971 struct tty *
972 tty_alloc_mutex(struct ttydevsw *tsw, void *sc, struct mtx *mutex)
973 {
974 	struct tty *tp;
975 
976 	/* Make sure the driver defines all routines. */
977 #define PATCH_FUNC(x) do {				\
978 	if (tsw->tsw_ ## x == NULL)			\
979 		tsw->tsw_ ## x = ttydevsw_def ## x;	\
980 } while (0)
981 	PATCH_FUNC(open);
982 	PATCH_FUNC(close);
983 	PATCH_FUNC(outwakeup);
984 	PATCH_FUNC(inwakeup);
985 	PATCH_FUNC(ioctl);
986 	PATCH_FUNC(cioctl);
987 	PATCH_FUNC(param);
988 	PATCH_FUNC(modem);
989 	PATCH_FUNC(mmap);
990 	PATCH_FUNC(pktnotify);
991 	PATCH_FUNC(free);
992 #undef PATCH_FUNC
993 
994 	tp = malloc(sizeof(struct tty), M_TTY, M_WAITOK|M_ZERO);
995 	tp->t_devsw = tsw;
996 	tp->t_devswsoftc = sc;
997 	tp->t_flags = tsw->tsw_flags;
998 
999 	tty_init_termios(tp);
1000 
1001 	cv_init(&tp->t_inwait, "ttyin");
1002 	cv_init(&tp->t_outwait, "ttyout");
1003 	cv_init(&tp->t_outserwait, "ttyosr");
1004 	cv_init(&tp->t_bgwait, "ttybg");
1005 	cv_init(&tp->t_dcdwait, "ttydcd");
1006 
1007 	/* Allow drivers to use a custom mutex to lock the TTY. */
1008 	if (mutex != NULL) {
1009 		tp->t_mtx = mutex;
1010 	} else {
1011 		tp->t_mtx = &tp->t_mtxobj;
1012 		mtx_init(&tp->t_mtxobj, "ttymtx", NULL, MTX_DEF);
1013 	}
1014 
1015 	knlist_init_mtx(&tp->t_inpoll.si_note, tp->t_mtx);
1016 	knlist_init_mtx(&tp->t_outpoll.si_note, tp->t_mtx);
1017 
1018 	return (tp);
1019 }
1020 
1021 static void
1022 tty_dealloc(void *arg)
1023 {
1024 	struct tty *tp = arg;
1025 
1026 	/* Make sure we haven't leaked buffers. */
1027 	MPASS(ttyinq_getsize(&tp->t_inq) == 0);
1028 	MPASS(ttyoutq_getsize(&tp->t_outq) == 0);
1029 
1030 	seldrain(&tp->t_inpoll);
1031 	seldrain(&tp->t_outpoll);
1032 	knlist_destroy(&tp->t_inpoll.si_note);
1033 	knlist_destroy(&tp->t_outpoll.si_note);
1034 
1035 	cv_destroy(&tp->t_inwait);
1036 	cv_destroy(&tp->t_outwait);
1037 	cv_destroy(&tp->t_bgwait);
1038 	cv_destroy(&tp->t_dcdwait);
1039 	cv_destroy(&tp->t_outserwait);
1040 
1041 	if (tp->t_mtx == &tp->t_mtxobj)
1042 		mtx_destroy(&tp->t_mtxobj);
1043 	ttydevsw_free(tp);
1044 	free(tp, M_TTY);
1045 }
1046 
1047 static void
1048 tty_rel_free(struct tty *tp)
1049 {
1050 	struct cdev *dev;
1051 
1052 	tty_lock_assert(tp, MA_OWNED);
1053 
1054 #define	TF_ACTIVITY	(TF_GONE|TF_OPENED|TF_HOOK|TF_OPENCLOSE)
1055 	if (tp->t_sessioncnt != 0 || (tp->t_flags & TF_ACTIVITY) != TF_GONE) {
1056 		/* TTY is still in use. */
1057 		tty_unlock(tp);
1058 		return;
1059 	}
1060 
1061 	/* TTY can be deallocated. */
1062 	dev = tp->t_dev;
1063 	tp->t_dev = NULL;
1064 	tty_unlock(tp);
1065 
1066 	if (dev != NULL) {
1067 		sx_xlock(&tty_list_sx);
1068 		TAILQ_REMOVE(&tty_list, tp, t_list);
1069 		tty_list_count--;
1070 		sx_xunlock(&tty_list_sx);
1071 		destroy_dev_sched_cb(dev, tty_dealloc, tp);
1072 	}
1073 }
1074 
1075 void
1076 tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
1077 {
1078 	MPASS(tp->t_sessioncnt > 0);
1079 	tty_lock_assert(tp, MA_OWNED);
1080 
1081 	if (tp->t_pgrp == pg)
1082 		tp->t_pgrp = NULL;
1083 
1084 	tty_unlock(tp);
1085 }
1086 
1087 void
1088 tty_rel_sess(struct tty *tp, struct session *sess)
1089 {
1090 	MPASS(tp->t_sessioncnt > 0);
1091 
1092 	/* Current session has left. */
1093 	if (tp->t_session == sess) {
1094 		tp->t_session = NULL;
1095 		MPASS(tp->t_pgrp == NULL);
1096 	}
1097 	tp->t_sessioncnt--;
1098 	tty_rel_free(tp);
1099 }
1100 
1101 void
1102 tty_rel_gone(struct tty *tp)
1103 {
1104 	MPASS(!tty_gone(tp));
1105 
1106 	/* Simulate carrier removal. */
1107 	ttydisc_modem(tp, 0);
1108 
1109 	/* Wake up all blocked threads. */
1110 	tty_wakeup(tp, FREAD|FWRITE);
1111 	cv_broadcast(&tp->t_bgwait);
1112 	cv_broadcast(&tp->t_dcdwait);
1113 
1114 	tp->t_flags |= TF_GONE;
1115 	tty_rel_free(tp);
1116 }
1117 
1118 /*
1119  * Exposing information about current TTY's through sysctl
1120  */
1121 
1122 static void
1123 tty_to_xtty(struct tty *tp, struct xtty *xt)
1124 {
1125 	tty_lock_assert(tp, MA_OWNED);
1126 
1127 	xt->xt_size = sizeof(struct xtty);
1128 	xt->xt_insize = ttyinq_getsize(&tp->t_inq);
1129 	xt->xt_incc = ttyinq_bytescanonicalized(&tp->t_inq);
1130 	xt->xt_inlc = ttyinq_bytesline(&tp->t_inq);
1131 	xt->xt_inlow = tp->t_inlow;
1132 	xt->xt_outsize = ttyoutq_getsize(&tp->t_outq);
1133 	xt->xt_outcc = ttyoutq_bytesused(&tp->t_outq);
1134 	xt->xt_outlow = tp->t_outlow;
1135 	xt->xt_column = tp->t_column;
1136 	xt->xt_pgid = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
1137 	xt->xt_sid = tp->t_session ? tp->t_session->s_sid : 0;
1138 	xt->xt_flags = tp->t_flags;
1139 	xt->xt_dev = tp->t_dev ? dev2udev(tp->t_dev) : NODEV;
1140 }
1141 
1142 static int
1143 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
1144 {
1145 	unsigned long lsize;
1146 	struct xtty *xtlist, *xt;
1147 	struct tty *tp;
1148 	int error;
1149 
1150 	sx_slock(&tty_list_sx);
1151 	lsize = tty_list_count * sizeof(struct xtty);
1152 	if (lsize == 0) {
1153 		sx_sunlock(&tty_list_sx);
1154 		return (0);
1155 	}
1156 
1157 	xtlist = xt = malloc(lsize, M_TTY, M_WAITOK);
1158 
1159 	TAILQ_FOREACH(tp, &tty_list, t_list) {
1160 		tty_lock(tp);
1161 		tty_to_xtty(tp, xt);
1162 		tty_unlock(tp);
1163 		xt++;
1164 	}
1165 	sx_sunlock(&tty_list_sx);
1166 
1167 	error = SYSCTL_OUT(req, xtlist, lsize);
1168 	free(xtlist, M_TTY);
1169 	return (error);
1170 }
1171 
1172 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
1173 	0, 0, sysctl_kern_ttys, "S,xtty", "List of TTYs");
1174 
1175 /*
1176  * Device node creation. Device has been set up, now we can expose it to
1177  * the user.
1178  */
1179 
1180 int
1181 tty_makedevf(struct tty *tp, struct ucred *cred, int flags,
1182     const char *fmt, ...)
1183 {
1184 	va_list ap;
1185 	struct make_dev_args args;
1186 	struct cdev *dev, *init, *lock, *cua, *cinit, *clock;
1187 	const char *prefix = "tty";
1188 	char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
1189 	uid_t uid;
1190 	gid_t gid;
1191 	mode_t mode;
1192 	int error;
1193 
1194 	/* Remove "tty" prefix from devices like PTY's. */
1195 	if (tp->t_flags & TF_NOPREFIX)
1196 		prefix = "";
1197 
1198 	va_start(ap, fmt);
1199 	vsnrprintf(name, sizeof name, 32, fmt, ap);
1200 	va_end(ap);
1201 
1202 	if (cred == NULL) {
1203 		/* System device. */
1204 		uid = UID_ROOT;
1205 		gid = GID_WHEEL;
1206 		mode = S_IRUSR|S_IWUSR;
1207 	} else {
1208 		/* User device. */
1209 		uid = cred->cr_ruid;
1210 		gid = GID_TTY;
1211 		mode = S_IRUSR|S_IWUSR|S_IWGRP;
1212 	}
1213 
1214 	flags = flags & TTYMK_CLONING ? MAKEDEV_REF : 0;
1215 	flags |= MAKEDEV_CHECKNAME;
1216 
1217 	/* Master call-in device. */
1218 	make_dev_args_init(&args);
1219 	args.mda_flags = flags;
1220 	args.mda_devsw = &ttydev_cdevsw;
1221 	args.mda_cr = cred;
1222 	args.mda_uid = uid;
1223 	args.mda_gid = gid;
1224 	args.mda_mode = mode;
1225 	args.mda_si_drv1 = tp;
1226 	error = make_dev_s(&args, &dev, "%s%s", prefix, name);
1227 	if (error != 0)
1228 		return (error);
1229 	tp->t_dev = dev;
1230 
1231 	init = lock = cua = cinit = clock = NULL;
1232 
1233 	/* Slave call-in devices. */
1234 	if (tp->t_flags & TF_INITLOCK) {
1235 		args.mda_devsw = &ttyil_cdevsw;
1236 		args.mda_unit = TTYUNIT_INIT;
1237 		args.mda_si_drv1 = tp;
1238 		args.mda_si_drv2 = &tp->t_termios_init_in;
1239 		error = make_dev_s(&args, &init, "%s%s.init", prefix, name);
1240 		if (error != 0)
1241 			goto fail;
1242 		dev_depends(dev, init);
1243 
1244 		args.mda_unit = TTYUNIT_LOCK;
1245 		args.mda_si_drv2 = &tp->t_termios_lock_in;
1246 		error = make_dev_s(&args, &lock, "%s%s.lock", prefix, name);
1247 		if (error != 0)
1248 			goto fail;
1249 		dev_depends(dev, lock);
1250 	}
1251 
1252 	/* Call-out devices. */
1253 	if (tp->t_flags & TF_CALLOUT) {
1254 		make_dev_args_init(&args);
1255 		args.mda_flags = flags;
1256 		args.mda_devsw = &ttydev_cdevsw;
1257 		args.mda_cr = cred;
1258 		args.mda_uid = UID_UUCP;
1259 		args.mda_gid = GID_DIALER;
1260 		args.mda_mode = 0660;
1261 		args.mda_unit = TTYUNIT_CALLOUT;
1262 		args.mda_si_drv1 = tp;
1263 		error = make_dev_s(&args, &cua, "cua%s", name);
1264 		if (error != 0)
1265 			goto fail;
1266 		dev_depends(dev, cua);
1267 
1268 		/* Slave call-out devices. */
1269 		if (tp->t_flags & TF_INITLOCK) {
1270 			args.mda_devsw = &ttyil_cdevsw;
1271 			args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_INIT;
1272 			args.mda_si_drv2 = &tp->t_termios_init_out;
1273 			error = make_dev_s(&args, &cinit, "cua%s.init", name);
1274 			if (error != 0)
1275 				goto fail;
1276 			dev_depends(dev, cinit);
1277 
1278 			args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_LOCK;
1279 			args.mda_si_drv2 = &tp->t_termios_lock_out;
1280 			error = make_dev_s(&args, &clock, "cua%s.lock", name);
1281 			if (error != 0)
1282 				goto fail;
1283 			dev_depends(dev, clock);
1284 		}
1285 	}
1286 
1287 	sx_xlock(&tty_list_sx);
1288 	TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
1289 	tty_list_count++;
1290 	sx_xunlock(&tty_list_sx);
1291 
1292 	return (0);
1293 
1294 fail:
1295 	destroy_dev(dev);
1296 	if (init)
1297 		destroy_dev(init);
1298 	if (lock)
1299 		destroy_dev(lock);
1300 	if (cinit)
1301 		destroy_dev(cinit);
1302 	if (clock)
1303 		destroy_dev(clock);
1304 
1305 	return (error);
1306 }
1307 
1308 /*
1309  * Signalling processes.
1310  */
1311 
1312 void
1313 tty_signal_sessleader(struct tty *tp, int sig)
1314 {
1315 	struct proc *p;
1316 
1317 	tty_lock_assert(tp, MA_OWNED);
1318 	MPASS(sig >= 1 && sig < NSIG);
1319 
1320 	/* Make signals start output again. */
1321 	tp->t_flags &= ~TF_STOPPED;
1322 
1323 	if (tp->t_session != NULL && tp->t_session->s_leader != NULL) {
1324 		p = tp->t_session->s_leader;
1325 		PROC_LOCK(p);
1326 		kern_psignal(p, sig);
1327 		PROC_UNLOCK(p);
1328 	}
1329 }
1330 
1331 void
1332 tty_signal_pgrp(struct tty *tp, int sig)
1333 {
1334 	ksiginfo_t ksi;
1335 
1336 	tty_lock_assert(tp, MA_OWNED);
1337 	MPASS(sig >= 1 && sig < NSIG);
1338 
1339 	/* Make signals start output again. */
1340 	tp->t_flags &= ~TF_STOPPED;
1341 
1342 	if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
1343 		tty_info(tp);
1344 	if (tp->t_pgrp != NULL) {
1345 		ksiginfo_init(&ksi);
1346 		ksi.ksi_signo = sig;
1347 		ksi.ksi_code = SI_KERNEL;
1348 		PGRP_LOCK(tp->t_pgrp);
1349 		pgsignal(tp->t_pgrp, sig, 1, &ksi);
1350 		PGRP_UNLOCK(tp->t_pgrp);
1351 	}
1352 }
1353 
1354 void
1355 tty_wakeup(struct tty *tp, int flags)
1356 {
1357 	if (tp->t_flags & TF_ASYNC && tp->t_sigio != NULL)
1358 		pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
1359 
1360 	if (flags & FWRITE) {
1361 		cv_broadcast(&tp->t_outwait);
1362 		selwakeup(&tp->t_outpoll);
1363 		KNOTE_LOCKED(&tp->t_outpoll.si_note, 0);
1364 	}
1365 	if (flags & FREAD) {
1366 		cv_broadcast(&tp->t_inwait);
1367 		selwakeup(&tp->t_inpoll);
1368 		KNOTE_LOCKED(&tp->t_inpoll.si_note, 0);
1369 	}
1370 }
1371 
1372 int
1373 tty_wait(struct tty *tp, struct cv *cv)
1374 {
1375 	int error;
1376 	int revokecnt = tp->t_revokecnt;
1377 
1378 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1379 	MPASS(!tty_gone(tp));
1380 
1381 	error = cv_wait_sig(cv, tp->t_mtx);
1382 
1383 	/* Bail out when the device slipped away. */
1384 	if (tty_gone(tp))
1385 		return (ENXIO);
1386 
1387 	/* Restart the system call when we may have been revoked. */
1388 	if (tp->t_revokecnt != revokecnt)
1389 		return (ERESTART);
1390 
1391 	return (error);
1392 }
1393 
1394 int
1395 tty_timedwait(struct tty *tp, struct cv *cv, int hz)
1396 {
1397 	int error;
1398 	int revokecnt = tp->t_revokecnt;
1399 
1400 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1401 	MPASS(!tty_gone(tp));
1402 
1403 	error = cv_timedwait_sig(cv, tp->t_mtx, hz);
1404 
1405 	/* Bail out when the device slipped away. */
1406 	if (tty_gone(tp))
1407 		return (ENXIO);
1408 
1409 	/* Restart the system call when we may have been revoked. */
1410 	if (tp->t_revokecnt != revokecnt)
1411 		return (ERESTART);
1412 
1413 	return (error);
1414 }
1415 
1416 void
1417 tty_flush(struct tty *tp, int flags)
1418 {
1419 	if (flags & FWRITE) {
1420 		tp->t_flags &= ~TF_HIWAT_OUT;
1421 		ttyoutq_flush(&tp->t_outq);
1422 		tty_wakeup(tp, FWRITE);
1423 		ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
1424 	}
1425 	if (flags & FREAD) {
1426 		tty_hiwat_in_unblock(tp);
1427 		ttyinq_flush(&tp->t_inq);
1428 		ttydevsw_inwakeup(tp);
1429 		ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
1430 	}
1431 }
1432 
1433 void
1434 tty_set_winsize(struct tty *tp, const struct winsize *wsz)
1435 {
1436 
1437 	if (memcmp(&tp->t_winsize, wsz, sizeof(*wsz)) == 0)
1438 		return;
1439 	tp->t_winsize = *wsz;
1440 	tty_signal_pgrp(tp, SIGWINCH);
1441 }
1442 
1443 static int
1444 tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, int fflag,
1445     struct thread *td)
1446 {
1447 	int error;
1448 
1449 	switch (cmd) {
1450 	/*
1451 	 * Modem commands.
1452 	 * The SER_* and TIOCM_* flags are the same, but one bit
1453 	 * shifted. I don't know why.
1454 	 */
1455 	case TIOCSDTR:
1456 		ttydevsw_modem(tp, SER_DTR, 0);
1457 		return (0);
1458 	case TIOCCDTR:
1459 		ttydevsw_modem(tp, 0, SER_DTR);
1460 		return (0);
1461 	case TIOCMSET: {
1462 		int bits = *(int *)data;
1463 		ttydevsw_modem(tp,
1464 		    (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1,
1465 		    ((~bits) & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1466 		return (0);
1467 	}
1468 	case TIOCMBIS: {
1469 		int bits = *(int *)data;
1470 		ttydevsw_modem(tp, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1, 0);
1471 		return (0);
1472 	}
1473 	case TIOCMBIC: {
1474 		int bits = *(int *)data;
1475 		ttydevsw_modem(tp, 0, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1476 		return (0);
1477 	}
1478 	case TIOCMGET:
1479 		*(int *)data = TIOCM_LE + (ttydevsw_modem(tp, 0, 0) << 1);
1480 		return (0);
1481 
1482 	case FIOASYNC:
1483 		if (*(int *)data)
1484 			tp->t_flags |= TF_ASYNC;
1485 		else
1486 			tp->t_flags &= ~TF_ASYNC;
1487 		return (0);
1488 	case FIONBIO:
1489 		/* This device supports non-blocking operation. */
1490 		return (0);
1491 	case FIONREAD:
1492 		*(int *)data = ttyinq_bytescanonicalized(&tp->t_inq);
1493 		return (0);
1494 	case FIONWRITE:
1495 	case TIOCOUTQ:
1496 		*(int *)data = ttyoutq_bytesused(&tp->t_outq);
1497 		return (0);
1498 	case FIOSETOWN:
1499 		if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1500 			/* Not allowed to set ownership. */
1501 			return (ENOTTY);
1502 
1503 		/* Temporarily unlock the TTY to set ownership. */
1504 		tty_unlock(tp);
1505 		error = fsetown(*(int *)data, &tp->t_sigio);
1506 		tty_lock(tp);
1507 		return (error);
1508 	case FIOGETOWN:
1509 		if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1510 			/* Not allowed to set ownership. */
1511 			return (ENOTTY);
1512 
1513 		/* Get ownership. */
1514 		*(int *)data = fgetown(&tp->t_sigio);
1515 		return (0);
1516 	case TIOCGETA:
1517 		/* Obtain terminal flags through tcgetattr(). */
1518 		*(struct termios*)data = tp->t_termios;
1519 		return (0);
1520 	case TIOCSETA:
1521 	case TIOCSETAW:
1522 	case TIOCSETAF: {
1523 		struct termios *t = data;
1524 
1525 		/*
1526 		 * Who makes up these funny rules? According to POSIX,
1527 		 * input baud rate is set equal to the output baud rate
1528 		 * when zero.
1529 		 */
1530 		if (t->c_ispeed == 0)
1531 			t->c_ispeed = t->c_ospeed;
1532 
1533 		/* Discard any unsupported bits. */
1534 		t->c_iflag &= TTYSUP_IFLAG;
1535 		t->c_oflag &= TTYSUP_OFLAG;
1536 		t->c_lflag &= TTYSUP_LFLAG;
1537 		t->c_cflag &= TTYSUP_CFLAG;
1538 
1539 		/* Set terminal flags through tcsetattr(). */
1540 		if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
1541 			error = tty_drain(tp, 0);
1542 			if (error)
1543 				return (error);
1544 			if (cmd == TIOCSETAF)
1545 				tty_flush(tp, FREAD);
1546 		}
1547 
1548 		/*
1549 		 * Only call param() when the flags really change.
1550 		 */
1551 		if ((t->c_cflag & CIGNORE) == 0 &&
1552 		    (tp->t_termios.c_cflag != t->c_cflag ||
1553 		    ((tp->t_termios.c_iflag ^ t->c_iflag) &
1554 		    (IXON|IXOFF|IXANY)) ||
1555 		    tp->t_termios.c_ispeed != t->c_ispeed ||
1556 		    tp->t_termios.c_ospeed != t->c_ospeed)) {
1557 			error = ttydevsw_param(tp, t);
1558 			if (error)
1559 				return (error);
1560 
1561 			/* XXX: CLOCAL? */
1562 
1563 			tp->t_termios.c_cflag = t->c_cflag & ~CIGNORE;
1564 			tp->t_termios.c_ispeed = t->c_ispeed;
1565 			tp->t_termios.c_ospeed = t->c_ospeed;
1566 
1567 			/* Baud rate has changed - update watermarks. */
1568 			tty_watermarks(tp);
1569 		}
1570 
1571 		/* Copy new non-device driver parameters. */
1572 		tp->t_termios.c_iflag = t->c_iflag;
1573 		tp->t_termios.c_oflag = t->c_oflag;
1574 		tp->t_termios.c_lflag = t->c_lflag;
1575 		memcpy(&tp->t_termios.c_cc, t->c_cc, sizeof t->c_cc);
1576 
1577 		ttydisc_optimize(tp);
1578 
1579 		if ((t->c_lflag & ICANON) == 0) {
1580 			/*
1581 			 * When in non-canonical mode, wake up all
1582 			 * readers. Canonicalize any partial input. VMIN
1583 			 * and VTIME could also be adjusted.
1584 			 */
1585 			ttyinq_canonicalize(&tp->t_inq);
1586 			tty_wakeup(tp, FREAD);
1587 		}
1588 
1589 		/*
1590 		 * For packet mode: notify the PTY consumer that VSTOP
1591 		 * and VSTART may have been changed.
1592 		 */
1593 		if (tp->t_termios.c_iflag & IXON &&
1594 		    tp->t_termios.c_cc[VSTOP] == CTRL('S') &&
1595 		    tp->t_termios.c_cc[VSTART] == CTRL('Q'))
1596 			ttydevsw_pktnotify(tp, TIOCPKT_DOSTOP);
1597 		else
1598 			ttydevsw_pktnotify(tp, TIOCPKT_NOSTOP);
1599 		return (0);
1600 	}
1601 	case TIOCGETD:
1602 		/* For compatibility - we only support TTYDISC. */
1603 		*(int *)data = TTYDISC;
1604 		return (0);
1605 	case TIOCGPGRP:
1606 		if (!tty_is_ctty(tp, td->td_proc))
1607 			return (ENOTTY);
1608 
1609 		if (tp->t_pgrp != NULL)
1610 			*(int *)data = tp->t_pgrp->pg_id;
1611 		else
1612 			*(int *)data = NO_PID;
1613 		return (0);
1614 	case TIOCGSID:
1615 		if (!tty_is_ctty(tp, td->td_proc))
1616 			return (ENOTTY);
1617 
1618 		MPASS(tp->t_session);
1619 		*(int *)data = tp->t_session->s_sid;
1620 		return (0);
1621 	case TIOCSCTTY: {
1622 		struct proc *p = td->td_proc;
1623 
1624 		/* XXX: This looks awful. */
1625 		tty_unlock(tp);
1626 		sx_xlock(&proctree_lock);
1627 		tty_lock(tp);
1628 
1629 		if (!SESS_LEADER(p)) {
1630 			/* Only the session leader may do this. */
1631 			sx_xunlock(&proctree_lock);
1632 			return (EPERM);
1633 		}
1634 
1635 		if (tp->t_session != NULL && tp->t_session == p->p_session) {
1636 			/* This is already our controlling TTY. */
1637 			sx_xunlock(&proctree_lock);
1638 			return (0);
1639 		}
1640 
1641 		if (p->p_session->s_ttyp != NULL ||
1642 		    (tp->t_session != NULL && tp->t_session->s_ttyvp != NULL &&
1643 		    tp->t_session->s_ttyvp->v_type != VBAD)) {
1644 			/*
1645 			 * There is already a relation between a TTY and
1646 			 * a session, or the caller is not the session
1647 			 * leader.
1648 			 *
1649 			 * Allow the TTY to be stolen when the vnode is
1650 			 * invalid, but the reference to the TTY is
1651 			 * still active.  This allows immediate reuse of
1652 			 * TTYs of which the session leader has been
1653 			 * killed or the TTY revoked.
1654 			 */
1655 			sx_xunlock(&proctree_lock);
1656 			return (EPERM);
1657 		}
1658 
1659 		/* Connect the session to the TTY. */
1660 		tp->t_session = p->p_session;
1661 		tp->t_session->s_ttyp = tp;
1662 		tp->t_sessioncnt++;
1663 		sx_xunlock(&proctree_lock);
1664 
1665 		/* Assign foreground process group. */
1666 		tp->t_pgrp = p->p_pgrp;
1667 		PROC_LOCK(p);
1668 		p->p_flag |= P_CONTROLT;
1669 		PROC_UNLOCK(p);
1670 
1671 		return (0);
1672 	}
1673 	case TIOCSPGRP: {
1674 		struct pgrp *pg;
1675 
1676 		/*
1677 		 * XXX: Temporarily unlock the TTY to locate the process
1678 		 * group. This code would be lot nicer if we would ever
1679 		 * decompose proctree_lock.
1680 		 */
1681 		tty_unlock(tp);
1682 		sx_slock(&proctree_lock);
1683 		pg = pgfind(*(int *)data);
1684 		if (pg != NULL)
1685 			PGRP_UNLOCK(pg);
1686 		if (pg == NULL || pg->pg_session != td->td_proc->p_session) {
1687 			sx_sunlock(&proctree_lock);
1688 			tty_lock(tp);
1689 			return (EPERM);
1690 		}
1691 		tty_lock(tp);
1692 
1693 		/*
1694 		 * Determine if this TTY is the controlling TTY after
1695 		 * relocking the TTY.
1696 		 */
1697 		if (!tty_is_ctty(tp, td->td_proc)) {
1698 			sx_sunlock(&proctree_lock);
1699 			return (ENOTTY);
1700 		}
1701 		tp->t_pgrp = pg;
1702 		sx_sunlock(&proctree_lock);
1703 
1704 		/* Wake up the background process groups. */
1705 		cv_broadcast(&tp->t_bgwait);
1706 		return (0);
1707 	}
1708 	case TIOCFLUSH: {
1709 		int flags = *(int *)data;
1710 
1711 		if (flags == 0)
1712 			flags = (FREAD|FWRITE);
1713 		else
1714 			flags &= (FREAD|FWRITE);
1715 		tty_flush(tp, flags);
1716 		return (0);
1717 	}
1718 	case TIOCDRAIN:
1719 		/* Drain TTY output. */
1720 		return tty_drain(tp, 0);
1721 	case TIOCCONS:
1722 		/* Set terminal as console TTY. */
1723 		if (*(int *)data) {
1724 			error = priv_check(td, PRIV_TTY_CONSOLE);
1725 			if (error)
1726 				return (error);
1727 
1728 			/*
1729 			 * XXX: constty should really need to be locked!
1730 			 * XXX: allow disconnected constty's to be stolen!
1731 			 */
1732 
1733 			if (constty == tp)
1734 				return (0);
1735 			if (constty != NULL)
1736 				return (EBUSY);
1737 
1738 			tty_unlock(tp);
1739 			constty_set(tp);
1740 			tty_lock(tp);
1741 		} else if (constty == tp) {
1742 			constty_clear();
1743 		}
1744 		return (0);
1745 	case TIOCGWINSZ:
1746 		/* Obtain window size. */
1747 		*(struct winsize*)data = tp->t_winsize;
1748 		return (0);
1749 	case TIOCSWINSZ:
1750 		/* Set window size. */
1751 		tty_set_winsize(tp, data);
1752 		return (0);
1753 	case TIOCEXCL:
1754 		tp->t_flags |= TF_EXCLUDE;
1755 		return (0);
1756 	case TIOCNXCL:
1757 		tp->t_flags &= ~TF_EXCLUDE;
1758 		return (0);
1759 	case TIOCSTOP:
1760 		tp->t_flags |= TF_STOPPED;
1761 		ttydevsw_pktnotify(tp, TIOCPKT_STOP);
1762 		return (0);
1763 	case TIOCSTART:
1764 		tp->t_flags &= ~TF_STOPPED;
1765 		ttydevsw_outwakeup(tp);
1766 		ttydevsw_pktnotify(tp, TIOCPKT_START);
1767 		return (0);
1768 	case TIOCSTAT:
1769 		tty_info(tp);
1770 		return (0);
1771 	case TIOCSTI:
1772 		if ((fflag & FREAD) == 0 && priv_check(td, PRIV_TTY_STI))
1773 			return (EPERM);
1774 		if (!tty_is_ctty(tp, td->td_proc) &&
1775 		    priv_check(td, PRIV_TTY_STI))
1776 			return (EACCES);
1777 		ttydisc_rint(tp, *(char *)data, 0);
1778 		ttydisc_rint_done(tp);
1779 		return (0);
1780 	}
1781 
1782 #ifdef COMPAT_43TTY
1783 	return tty_ioctl_compat(tp, cmd, data, fflag, td);
1784 #else /* !COMPAT_43TTY */
1785 	return (ENOIOCTL);
1786 #endif /* COMPAT_43TTY */
1787 }
1788 
1789 int
1790 tty_ioctl(struct tty *tp, u_long cmd, void *data, int fflag, struct thread *td)
1791 {
1792 	int error;
1793 
1794 	tty_lock_assert(tp, MA_OWNED);
1795 
1796 	if (tty_gone(tp))
1797 		return (ENXIO);
1798 
1799 	error = ttydevsw_ioctl(tp, cmd, data, td);
1800 	if (error == ENOIOCTL)
1801 		error = tty_generic_ioctl(tp, cmd, data, fflag, td);
1802 
1803 	return (error);
1804 }
1805 
1806 dev_t
1807 tty_udev(struct tty *tp)
1808 {
1809 	if (tp->t_dev)
1810 		return dev2udev(tp->t_dev);
1811 	else
1812 		return NODEV;
1813 }
1814 
1815 int
1816 tty_checkoutq(struct tty *tp)
1817 {
1818 
1819 	/* 256 bytes should be enough to print a log message. */
1820 	return (ttyoutq_bytesleft(&tp->t_outq) >= 256);
1821 }
1822 
1823 void
1824 tty_hiwat_in_block(struct tty *tp)
1825 {
1826 
1827 	if ((tp->t_flags & TF_HIWAT_IN) == 0 &&
1828 	    tp->t_termios.c_iflag & IXOFF &&
1829 	    tp->t_termios.c_cc[VSTOP] != _POSIX_VDISABLE) {
1830 		/*
1831 		 * Input flow control. Only enter the high watermark when we
1832 		 * can successfully store the VSTOP character.
1833 		 */
1834 		if (ttyoutq_write_nofrag(&tp->t_outq,
1835 		    &tp->t_termios.c_cc[VSTOP], 1) == 0)
1836 			tp->t_flags |= TF_HIWAT_IN;
1837 	} else {
1838 		/* No input flow control. */
1839 		tp->t_flags |= TF_HIWAT_IN;
1840 	}
1841 }
1842 
1843 void
1844 tty_hiwat_in_unblock(struct tty *tp)
1845 {
1846 
1847 	if (tp->t_flags & TF_HIWAT_IN &&
1848 	    tp->t_termios.c_iflag & IXOFF &&
1849 	    tp->t_termios.c_cc[VSTART] != _POSIX_VDISABLE) {
1850 		/*
1851 		 * Input flow control. Only leave the high watermark when we
1852 		 * can successfully store the VSTART character.
1853 		 */
1854 		if (ttyoutq_write_nofrag(&tp->t_outq,
1855 		    &tp->t_termios.c_cc[VSTART], 1) == 0)
1856 			tp->t_flags &= ~TF_HIWAT_IN;
1857 	} else {
1858 		/* No input flow control. */
1859 		tp->t_flags &= ~TF_HIWAT_IN;
1860 	}
1861 
1862 	if (!tty_gone(tp))
1863 		ttydevsw_inwakeup(tp);
1864 }
1865 
1866 /*
1867  * TTY hooks interface.
1868  */
1869 
1870 static int
1871 ttyhook_defrint(struct tty *tp, char c, int flags)
1872 {
1873 
1874 	if (ttyhook_rint_bypass(tp, &c, 1) != 1)
1875 		return (-1);
1876 
1877 	return (0);
1878 }
1879 
1880 int
1881 ttyhook_register(struct tty **rtp, struct proc *p, int fd,
1882     struct ttyhook *th, void *softc)
1883 {
1884 	struct tty *tp;
1885 	struct file *fp;
1886 	struct cdev *dev;
1887 	struct cdevsw *cdp;
1888 	struct filedesc *fdp;
1889 	cap_rights_t rights;
1890 	int error, ref;
1891 
1892 	/* Validate the file descriptor. */
1893 	fdp = p->p_fd;
1894 	error = fget_unlocked(fdp, fd, cap_rights_init(&rights, CAP_TTYHOOK),
1895 	    &fp, NULL);
1896 	if (error != 0)
1897 		return (error);
1898 	if (fp->f_ops == &badfileops) {
1899 		error = EBADF;
1900 		goto done1;
1901 	}
1902 
1903 	/*
1904 	 * Make sure the vnode is bound to a character device.
1905 	 * Unlocked check for the vnode type is ok there, because we
1906 	 * only shall prevent calling devvn_refthread on the file that
1907 	 * never has been opened over a character device.
1908 	 */
1909 	if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR) {
1910 		error = EINVAL;
1911 		goto done1;
1912 	}
1913 
1914 	/* Make sure it is a TTY. */
1915 	cdp = devvn_refthread(fp->f_vnode, &dev, &ref);
1916 	if (cdp == NULL) {
1917 		error = ENXIO;
1918 		goto done1;
1919 	}
1920 	if (dev != fp->f_data) {
1921 		error = ENXIO;
1922 		goto done2;
1923 	}
1924 	if (cdp != &ttydev_cdevsw) {
1925 		error = ENOTTY;
1926 		goto done2;
1927 	}
1928 	tp = dev->si_drv1;
1929 
1930 	/* Try to attach the hook to the TTY. */
1931 	error = EBUSY;
1932 	tty_lock(tp);
1933 	MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
1934 	if (tp->t_flags & TF_HOOK)
1935 		goto done3;
1936 
1937 	tp->t_flags |= TF_HOOK;
1938 	tp->t_hook = th;
1939 	tp->t_hooksoftc = softc;
1940 	*rtp = tp;
1941 	error = 0;
1942 
1943 	/* Maybe we can switch into bypass mode now. */
1944 	ttydisc_optimize(tp);
1945 
1946 	/* Silently convert rint() calls to rint_bypass() when possible. */
1947 	if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
1948 		th->th_rint = ttyhook_defrint;
1949 
1950 done3:	tty_unlock(tp);
1951 done2:	dev_relthread(dev, ref);
1952 done1:	fdrop(fp, curthread);
1953 	return (error);
1954 }
1955 
1956 void
1957 ttyhook_unregister(struct tty *tp)
1958 {
1959 
1960 	tty_lock_assert(tp, MA_OWNED);
1961 	MPASS(tp->t_flags & TF_HOOK);
1962 
1963 	/* Disconnect the hook. */
1964 	tp->t_flags &= ~TF_HOOK;
1965 	tp->t_hook = NULL;
1966 
1967 	/* Maybe we need to leave bypass mode. */
1968 	ttydisc_optimize(tp);
1969 
1970 	/* Maybe deallocate the TTY as well. */
1971 	tty_rel_free(tp);
1972 }
1973 
1974 /*
1975  * /dev/console handling.
1976  */
1977 
1978 static int
1979 ttyconsdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
1980 {
1981 	struct tty *tp;
1982 
1983 	/* System has no console device. */
1984 	if (dev_console_filename == NULL)
1985 		return (ENXIO);
1986 
1987 	/* Look up corresponding TTY by device name. */
1988 	sx_slock(&tty_list_sx);
1989 	TAILQ_FOREACH(tp, &tty_list, t_list) {
1990 		if (strcmp(dev_console_filename, tty_devname(tp)) == 0) {
1991 			dev_console->si_drv1 = tp;
1992 			break;
1993 		}
1994 	}
1995 	sx_sunlock(&tty_list_sx);
1996 
1997 	/* System console has no TTY associated. */
1998 	if (dev_console->si_drv1 == NULL)
1999 		return (ENXIO);
2000 
2001 	return (ttydev_open(dev, oflags, devtype, td));
2002 }
2003 
2004 static int
2005 ttyconsdev_write(struct cdev *dev, struct uio *uio, int ioflag)
2006 {
2007 
2008 	log_console(uio);
2009 
2010 	return (ttydev_write(dev, uio, ioflag));
2011 }
2012 
2013 /*
2014  * /dev/console is a little different than normal TTY's.  When opened,
2015  * it determines which TTY to use.  When data gets written to it, it
2016  * will be logged in the kernel message buffer.
2017  */
2018 static struct cdevsw ttyconsdev_cdevsw = {
2019 	.d_version	= D_VERSION,
2020 	.d_open		= ttyconsdev_open,
2021 	.d_close	= ttydev_close,
2022 	.d_read		= ttydev_read,
2023 	.d_write	= ttyconsdev_write,
2024 	.d_ioctl	= ttydev_ioctl,
2025 	.d_kqfilter	= ttydev_kqfilter,
2026 	.d_poll		= ttydev_poll,
2027 	.d_mmap		= ttydev_mmap,
2028 	.d_name		= "ttyconsdev",
2029 	.d_flags	= D_TTY,
2030 };
2031 
2032 static void
2033 ttyconsdev_init(void *unused)
2034 {
2035 
2036 	dev_console = make_dev_credf(MAKEDEV_ETERNAL, &ttyconsdev_cdevsw, 0,
2037 	    NULL, UID_ROOT, GID_WHEEL, 0600, "console");
2038 }
2039 
2040 SYSINIT(tty, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyconsdev_init, NULL);
2041 
2042 void
2043 ttyconsdev_select(const char *name)
2044 {
2045 
2046 	dev_console_filename = name;
2047 }
2048 
2049 /*
2050  * Debugging routines.
2051  */
2052 
2053 #include "opt_ddb.h"
2054 #ifdef DDB
2055 #include <ddb/ddb.h>
2056 #include <ddb/db_sym.h>
2057 
2058 static struct {
2059 	int flag;
2060 	char val;
2061 } ttystates[] = {
2062 #if 0
2063 	{ TF_NOPREFIX,		'N' },
2064 #endif
2065 	{ TF_INITLOCK,		'I' },
2066 	{ TF_CALLOUT,		'C' },
2067 
2068 	/* Keep these together -> 'Oi' and 'Oo'. */
2069 	{ TF_OPENED,		'O' },
2070 	{ TF_OPENED_IN,		'i' },
2071 	{ TF_OPENED_OUT,	'o' },
2072 	{ TF_OPENED_CONS,	'c' },
2073 
2074 	{ TF_GONE,		'G' },
2075 	{ TF_OPENCLOSE,		'B' },
2076 	{ TF_ASYNC,		'Y' },
2077 	{ TF_LITERAL,		'L' },
2078 
2079 	/* Keep these together -> 'Hi' and 'Ho'. */
2080 	{ TF_HIWAT,		'H' },
2081 	{ TF_HIWAT_IN,		'i' },
2082 	{ TF_HIWAT_OUT,		'o' },
2083 
2084 	{ TF_STOPPED,		'S' },
2085 	{ TF_EXCLUDE,		'X' },
2086 	{ TF_BYPASS,		'l' },
2087 	{ TF_ZOMBIE,		'Z' },
2088 	{ TF_HOOK,		's' },
2089 
2090 	/* Keep these together -> 'bi' and 'bo'. */
2091 	{ TF_BUSY,		'b' },
2092 	{ TF_BUSY_IN,		'i' },
2093 	{ TF_BUSY_OUT,		'o' },
2094 
2095 	{ 0,			'\0'},
2096 };
2097 
2098 #define	TTY_FLAG_BITS \
2099 	"\20\1NOPREFIX\2INITLOCK\3CALLOUT\4OPENED_IN\5OPENED_OUT\6GONE" \
2100 	"\7OPENCLOSE\10ASYNC\11LITERAL\12HIWAT_IN\13HIWAT_OUT\14STOPPED" \
2101 	"\15EXCLUDE\16BYPASS\17ZOMBIE\20HOOK"
2102 
2103 #define DB_PRINTSYM(name, addr) \
2104 	db_printf("%s  " #name ": ", sep); \
2105 	db_printsym((db_addr_t) addr, DB_STGY_ANY); \
2106 	db_printf("\n");
2107 
2108 static void
2109 _db_show_devsw(const char *sep, const struct ttydevsw *tsw)
2110 {
2111 	db_printf("%sdevsw: ", sep);
2112 	db_printsym((db_addr_t)tsw, DB_STGY_ANY);
2113 	db_printf(" (%p)\n", tsw);
2114 	DB_PRINTSYM(open, tsw->tsw_open);
2115 	DB_PRINTSYM(close, tsw->tsw_close);
2116 	DB_PRINTSYM(outwakeup, tsw->tsw_outwakeup);
2117 	DB_PRINTSYM(inwakeup, tsw->tsw_inwakeup);
2118 	DB_PRINTSYM(ioctl, tsw->tsw_ioctl);
2119 	DB_PRINTSYM(param, tsw->tsw_param);
2120 	DB_PRINTSYM(modem, tsw->tsw_modem);
2121 	DB_PRINTSYM(mmap, tsw->tsw_mmap);
2122 	DB_PRINTSYM(pktnotify, tsw->tsw_pktnotify);
2123 	DB_PRINTSYM(free, tsw->tsw_free);
2124 }
2125 static void
2126 _db_show_hooks(const char *sep, const struct ttyhook *th)
2127 {
2128 	db_printf("%shook: ", sep);
2129 	db_printsym((db_addr_t)th, DB_STGY_ANY);
2130 	db_printf(" (%p)\n", th);
2131 	if (th == NULL)
2132 		return;
2133 	DB_PRINTSYM(rint, th->th_rint);
2134 	DB_PRINTSYM(rint_bypass, th->th_rint_bypass);
2135 	DB_PRINTSYM(rint_done, th->th_rint_done);
2136 	DB_PRINTSYM(rint_poll, th->th_rint_poll);
2137 	DB_PRINTSYM(getc_inject, th->th_getc_inject);
2138 	DB_PRINTSYM(getc_capture, th->th_getc_capture);
2139 	DB_PRINTSYM(getc_poll, th->th_getc_poll);
2140 	DB_PRINTSYM(close, th->th_close);
2141 }
2142 
2143 static void
2144 _db_show_termios(const char *name, const struct termios *t)
2145 {
2146 
2147 	db_printf("%s: iflag 0x%x oflag 0x%x cflag 0x%x "
2148 	    "lflag 0x%x ispeed %u ospeed %u\n", name,
2149 	    t->c_iflag, t->c_oflag, t->c_cflag, t->c_lflag,
2150 	    t->c_ispeed, t->c_ospeed);
2151 }
2152 
2153 /* DDB command to show TTY statistics. */
2154 DB_SHOW_COMMAND(tty, db_show_tty)
2155 {
2156 	struct tty *tp;
2157 
2158 	if (!have_addr) {
2159 		db_printf("usage: show tty <addr>\n");
2160 		return;
2161 	}
2162 	tp = (struct tty *)addr;
2163 
2164 	db_printf("0x%p: %s\n", tp, tty_devname(tp));
2165 	db_printf("\tmtx: %p\n", tp->t_mtx);
2166 	db_printf("\tflags: %b\n", tp->t_flags, TTY_FLAG_BITS);
2167 	db_printf("\trevokecnt: %u\n", tp->t_revokecnt);
2168 
2169 	/* Buffering mechanisms. */
2170 	db_printf("\tinq: %p begin %u linestart %u reprint %u end %u "
2171 	    "nblocks %u quota %u\n", &tp->t_inq, tp->t_inq.ti_begin,
2172 	    tp->t_inq.ti_linestart, tp->t_inq.ti_reprint, tp->t_inq.ti_end,
2173 	    tp->t_inq.ti_nblocks, tp->t_inq.ti_quota);
2174 	db_printf("\toutq: %p begin %u end %u nblocks %u quota %u\n",
2175 	    &tp->t_outq, tp->t_outq.to_begin, tp->t_outq.to_end,
2176 	    tp->t_outq.to_nblocks, tp->t_outq.to_quota);
2177 	db_printf("\tinlow: %zu\n", tp->t_inlow);
2178 	db_printf("\toutlow: %zu\n", tp->t_outlow);
2179 	_db_show_termios("\ttermios", &tp->t_termios);
2180 	db_printf("\twinsize: row %u col %u xpixel %u ypixel %u\n",
2181 	    tp->t_winsize.ws_row, tp->t_winsize.ws_col,
2182 	    tp->t_winsize.ws_xpixel, tp->t_winsize.ws_ypixel);
2183 	db_printf("\tcolumn: %u\n", tp->t_column);
2184 	db_printf("\twritepos: %u\n", tp->t_writepos);
2185 	db_printf("\tcompatflags: 0x%x\n", tp->t_compatflags);
2186 
2187 	/* Init/lock-state devices. */
2188 	_db_show_termios("\ttermios_init_in", &tp->t_termios_init_in);
2189 	_db_show_termios("\ttermios_init_out", &tp->t_termios_init_out);
2190 	_db_show_termios("\ttermios_lock_in", &tp->t_termios_lock_in);
2191 	_db_show_termios("\ttermios_lock_out", &tp->t_termios_lock_out);
2192 
2193 	/* Hooks */
2194 	_db_show_devsw("\t", tp->t_devsw);
2195 	_db_show_hooks("\t", tp->t_hook);
2196 
2197 	/* Process info. */
2198 	db_printf("\tpgrp: %p gid %d jobc %d\n", tp->t_pgrp,
2199 	    tp->t_pgrp ? tp->t_pgrp->pg_id : 0,
2200 	    tp->t_pgrp ? tp->t_pgrp->pg_jobc : 0);
2201 	db_printf("\tsession: %p", tp->t_session);
2202 	if (tp->t_session != NULL)
2203 	    db_printf(" count %u leader %p tty %p sid %d login %s",
2204 		tp->t_session->s_count, tp->t_session->s_leader,
2205 		tp->t_session->s_ttyp, tp->t_session->s_sid,
2206 		tp->t_session->s_login);
2207 	db_printf("\n");
2208 	db_printf("\tsessioncnt: %u\n", tp->t_sessioncnt);
2209 	db_printf("\tdevswsoftc: %p\n", tp->t_devswsoftc);
2210 	db_printf("\thooksoftc: %p\n", tp->t_hooksoftc);
2211 	db_printf("\tdev: %p\n", tp->t_dev);
2212 }
2213 
2214 /* DDB command to list TTYs. */
2215 DB_SHOW_ALL_COMMAND(ttys, db_show_all_ttys)
2216 {
2217 	struct tty *tp;
2218 	size_t isiz, osiz;
2219 	int i, j;
2220 
2221 	/* Make the output look like `pstat -t'. */
2222 	db_printf("PTR        ");
2223 #if defined(__LP64__)
2224 	db_printf("        ");
2225 #endif
2226 	db_printf("      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   "
2227 	    "COL  SESS  PGID STATE\n");
2228 
2229 	TAILQ_FOREACH(tp, &tty_list, t_list) {
2230 		isiz = tp->t_inq.ti_nblocks * TTYINQ_DATASIZE;
2231 		osiz = tp->t_outq.to_nblocks * TTYOUTQ_DATASIZE;
2232 
2233 		db_printf("%p %10s %5zu %4u %4u %4zu %5zu %4u %4zu %5u %5d %5d ",
2234 		    tp,
2235 		    tty_devname(tp),
2236 		    isiz,
2237 		    tp->t_inq.ti_linestart - tp->t_inq.ti_begin,
2238 		    tp->t_inq.ti_end - tp->t_inq.ti_linestart,
2239 		    isiz - tp->t_inlow,
2240 		    osiz,
2241 		    tp->t_outq.to_end - tp->t_outq.to_begin,
2242 		    osiz - tp->t_outlow,
2243 		    MIN(tp->t_column, 99999),
2244 		    tp->t_session ? tp->t_session->s_sid : 0,
2245 		    tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
2246 
2247 		/* Flag bits. */
2248 		for (i = j = 0; ttystates[i].flag; i++)
2249 			if (tp->t_flags & ttystates[i].flag) {
2250 				db_printf("%c", ttystates[i].val);
2251 				j++;
2252 			}
2253 		if (j == 0)
2254 			db_printf("-");
2255 		db_printf("\n");
2256 	}
2257 }
2258 #endif /* DDB */
2259