xref: /freebsd/sys/kern/tty.c (revision 361e428888e630eb708c72cf31579a25ba5d4f03)
1 /*-
2  * Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Portions of this software were developed under sponsorship from Snow
6  * B.V., the Netherlands.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include "opt_capsicum.h"
34 #include "opt_compat.h"
35 
36 #include <sys/param.h>
37 #include <sys/capsicum.h>
38 #include <sys/conf.h>
39 #include <sys/cons.h>
40 #include <sys/fcntl.h>
41 #include <sys/file.h>
42 #include <sys/filedesc.h>
43 #include <sys/filio.h>
44 #ifdef COMPAT_43TTY
45 #include <sys/ioctl_compat.h>
46 #endif /* COMPAT_43TTY */
47 #include <sys/kernel.h>
48 #include <sys/limits.h>
49 #include <sys/malloc.h>
50 #include <sys/mount.h>
51 #include <sys/poll.h>
52 #include <sys/priv.h>
53 #include <sys/proc.h>
54 #include <sys/serial.h>
55 #include <sys/signal.h>
56 #include <sys/stat.h>
57 #include <sys/sx.h>
58 #include <sys/sysctl.h>
59 #include <sys/systm.h>
60 #include <sys/tty.h>
61 #include <sys/ttycom.h>
62 #define TTYDEFCHARS
63 #include <sys/ttydefaults.h>
64 #undef TTYDEFCHARS
65 #include <sys/ucred.h>
66 #include <sys/vnode.h>
67 
68 #include <machine/stdarg.h>
69 
70 static MALLOC_DEFINE(M_TTY, "tty", "tty device");
71 
72 static void tty_rel_free(struct tty *tp);
73 
74 static TAILQ_HEAD(, tty) tty_list = TAILQ_HEAD_INITIALIZER(tty_list);
75 static struct sx tty_list_sx;
76 SX_SYSINIT(tty_list, &tty_list_sx, "tty list");
77 static unsigned int tty_list_count = 0;
78 
79 /* Character device of /dev/console. */
80 static struct cdev	*dev_console;
81 static const char	*dev_console_filename;
82 
83 /*
84  * Flags that are supported and stored by this implementation.
85  */
86 #define TTYSUP_IFLAG	(IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK|ISTRIP|\
87 			INLCR|IGNCR|ICRNL|IXON|IXOFF|IXANY|IMAXBEL)
88 #define TTYSUP_OFLAG	(OPOST|ONLCR|TAB3|ONOEOT|OCRNL|ONOCR|ONLRET)
89 #define TTYSUP_LFLAG	(ECHOKE|ECHOE|ECHOK|ECHO|ECHONL|ECHOPRT|\
90 			ECHOCTL|ISIG|ICANON|ALTWERASE|IEXTEN|TOSTOP|\
91 			FLUSHO|NOKERNINFO|NOFLSH)
92 #define TTYSUP_CFLAG	(CIGNORE|CSIZE|CSTOPB|CREAD|PARENB|PARODD|\
93 			HUPCL|CLOCAL|CCTS_OFLOW|CRTS_IFLOW|CDTR_IFLOW|\
94 			CDSR_OFLOW|CCAR_OFLOW)
95 
96 #define	TTY_CALLOUT(tp,d) (dev2unit(d) & TTYUNIT_CALLOUT)
97 
98 /*
99  * Set TTY buffer sizes.
100  */
101 
102 #define	TTYBUF_MAX	65536
103 
104 static void
105 tty_watermarks(struct tty *tp)
106 {
107 	size_t bs = 0;
108 
109 	/* Provide an input buffer for 0.2 seconds of data. */
110 	if (tp->t_termios.c_cflag & CREAD)
111 		bs = MIN(tp->t_termios.c_ispeed / 5, TTYBUF_MAX);
112 	ttyinq_setsize(&tp->t_inq, tp, bs);
113 
114 	/* Set low watermark at 10% (when 90% is available). */
115 	tp->t_inlow = (ttyinq_getallocatedsize(&tp->t_inq) * 9) / 10;
116 
117 	/* Provide an output buffer for 0.2 seconds of data. */
118 	bs = MIN(tp->t_termios.c_ospeed / 5, TTYBUF_MAX);
119 	ttyoutq_setsize(&tp->t_outq, tp, bs);
120 
121 	/* Set low watermark at 10% (when 90% is available). */
122 	tp->t_outlow = (ttyoutq_getallocatedsize(&tp->t_outq) * 9) / 10;
123 }
124 
125 static int
126 tty_drain(struct tty *tp, int leaving)
127 {
128 	size_t bytesused;
129 	int error, revokecnt;
130 
131 	if (ttyhook_hashook(tp, getc_inject))
132 		/* buffer is inaccessible */
133 		return (0);
134 
135 	while (ttyoutq_bytesused(&tp->t_outq) > 0 || ttydevsw_busy(tp)) {
136 		ttydevsw_outwakeup(tp);
137 		/* Could be handled synchronously. */
138 		bytesused = ttyoutq_bytesused(&tp->t_outq);
139 		if (bytesused == 0 && !ttydevsw_busy(tp))
140 			return (0);
141 
142 		/* Wait for data to be drained. */
143 		if (leaving) {
144 			revokecnt = tp->t_revokecnt;
145 			error = tty_timedwait(tp, &tp->t_outwait, hz);
146 			switch (error) {
147 			case ERESTART:
148 				if (revokecnt != tp->t_revokecnt)
149 					error = 0;
150 				break;
151 			case EWOULDBLOCK:
152 				if (ttyoutq_bytesused(&tp->t_outq) < bytesused)
153 					error = 0;
154 				break;
155 			}
156 		} else
157 			error = tty_wait(tp, &tp->t_outwait);
158 
159 		if (error)
160 			return (error);
161 	}
162 
163 	return (0);
164 }
165 
166 /*
167  * Though ttydev_enter() and ttydev_leave() seem to be related, they
168  * don't have to be used together. ttydev_enter() is used by the cdev
169  * operations to prevent an actual operation from being processed when
170  * the TTY has been abandoned. ttydev_leave() is used by ttydev_open()
171  * and ttydev_close() to determine whether per-TTY data should be
172  * deallocated.
173  */
174 
175 static __inline int
176 ttydev_enter(struct tty *tp)
177 {
178 
179 	tty_lock(tp);
180 
181 	if (tty_gone(tp) || !tty_opened(tp)) {
182 		/* Device is already gone. */
183 		tty_unlock(tp);
184 		return (ENXIO);
185 	}
186 
187 	return (0);
188 }
189 
190 static void
191 ttydev_leave(struct tty *tp)
192 {
193 
194 	tty_lock_assert(tp, MA_OWNED);
195 
196 	if (tty_opened(tp) || tp->t_flags & TF_OPENCLOSE) {
197 		/* Device is still opened somewhere. */
198 		tty_unlock(tp);
199 		return;
200 	}
201 
202 	tp->t_flags |= TF_OPENCLOSE;
203 
204 	/* Stop asynchronous I/O. */
205 	funsetown(&tp->t_sigio);
206 
207 	/* Remove console TTY. */
208 	if (constty == tp)
209 		constty_clear();
210 
211 	/* Drain any output. */
212 	MPASS((tp->t_flags & TF_STOPPED) == 0);
213 	if (!tty_gone(tp))
214 		tty_drain(tp, 1);
215 
216 	ttydisc_close(tp);
217 
218 	/* Free i/o queues now since they might be large. */
219 	ttyinq_free(&tp->t_inq);
220 	tp->t_inlow = 0;
221 	ttyoutq_free(&tp->t_outq);
222 	tp->t_outlow = 0;
223 
224 	knlist_clear(&tp->t_inpoll.si_note, 1);
225 	knlist_clear(&tp->t_outpoll.si_note, 1);
226 
227 	if (!tty_gone(tp))
228 		ttydevsw_close(tp);
229 
230 	tp->t_flags &= ~TF_OPENCLOSE;
231 	cv_broadcast(&tp->t_dcdwait);
232 	tty_rel_free(tp);
233 }
234 
235 /*
236  * Operations that are exposed through the character device in /dev.
237  */
238 static int
239 ttydev_open(struct cdev *dev, int oflags, int devtype __unused,
240     struct thread *td)
241 {
242 	struct tty *tp;
243 	int error;
244 
245 	tp = dev->si_drv1;
246 	error = 0;
247 	tty_lock(tp);
248 	if (tty_gone(tp)) {
249 		/* Device is already gone. */
250 		tty_unlock(tp);
251 		return (ENXIO);
252 	}
253 
254 	/*
255 	 * Block when other processes are currently opening or closing
256 	 * the TTY.
257 	 */
258 	while (tp->t_flags & TF_OPENCLOSE) {
259 		error = tty_wait(tp, &tp->t_dcdwait);
260 		if (error != 0) {
261 			tty_unlock(tp);
262 			return (error);
263 		}
264 	}
265 	tp->t_flags |= TF_OPENCLOSE;
266 
267 	/*
268 	 * Make sure the "tty" and "cua" device cannot be opened at the
269 	 * same time.  The console is a "tty" device.
270 	 */
271 	if (TTY_CALLOUT(tp, dev)) {
272 		if (tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) {
273 			error = EBUSY;
274 			goto done;
275 		}
276 	} else {
277 		if (tp->t_flags & TF_OPENED_OUT) {
278 			error = EBUSY;
279 			goto done;
280 		}
281 	}
282 
283 	if (tp->t_flags & TF_EXCLUDE && priv_check(td, PRIV_TTY_EXCLUSIVE)) {
284 		error = EBUSY;
285 		goto done;
286 	}
287 
288 	if (!tty_opened(tp)) {
289 		/* Set proper termios flags. */
290 		if (TTY_CALLOUT(tp, dev))
291 			tp->t_termios = tp->t_termios_init_out;
292 		else
293 			tp->t_termios = tp->t_termios_init_in;
294 		ttydevsw_param(tp, &tp->t_termios);
295 		/* Prevent modem control on callout devices and /dev/console. */
296 		if (TTY_CALLOUT(tp, dev) || dev == dev_console)
297 			tp->t_termios.c_cflag |= CLOCAL;
298 
299 		ttydevsw_modem(tp, SER_DTR|SER_RTS, 0);
300 
301 		error = ttydevsw_open(tp);
302 		if (error != 0)
303 			goto done;
304 
305 		ttydisc_open(tp);
306 		tty_watermarks(tp); /* XXXGL: drops lock */
307 	}
308 
309 	/* Wait for Carrier Detect. */
310 	if ((oflags & O_NONBLOCK) == 0 &&
311 	    (tp->t_termios.c_cflag & CLOCAL) == 0) {
312 		while ((ttydevsw_modem(tp, 0, 0) & SER_DCD) == 0) {
313 			error = tty_wait(tp, &tp->t_dcdwait);
314 			if (error != 0)
315 				goto done;
316 		}
317 	}
318 
319 	if (dev == dev_console)
320 		tp->t_flags |= TF_OPENED_CONS;
321 	else if (TTY_CALLOUT(tp, dev))
322 		tp->t_flags |= TF_OPENED_OUT;
323 	else
324 		tp->t_flags |= TF_OPENED_IN;
325 	MPASS((tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) == 0 ||
326 	    (tp->t_flags & TF_OPENED_OUT) == 0);
327 
328 done:	tp->t_flags &= ~TF_OPENCLOSE;
329 	cv_broadcast(&tp->t_dcdwait);
330 	ttydev_leave(tp);
331 
332 	return (error);
333 }
334 
335 static int
336 ttydev_close(struct cdev *dev, int fflag, int devtype __unused,
337     struct thread *td __unused)
338 {
339 	struct tty *tp = dev->si_drv1;
340 
341 	tty_lock(tp);
342 
343 	/*
344 	 * Don't actually close the device if it is being used as the
345 	 * console.
346 	 */
347 	MPASS((tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) == 0 ||
348 	    (tp->t_flags & TF_OPENED_OUT) == 0);
349 	if (dev == dev_console)
350 		tp->t_flags &= ~TF_OPENED_CONS;
351 	else
352 		tp->t_flags &= ~(TF_OPENED_IN|TF_OPENED_OUT);
353 
354 	if (tp->t_flags & TF_OPENED) {
355 		tty_unlock(tp);
356 		return (0);
357 	}
358 
359 	/*
360 	 * This can only be called once. The callin and the callout
361 	 * devices cannot be opened at the same time.
362 	 */
363 	tp->t_flags &= ~(TF_EXCLUDE|TF_STOPPED);
364 
365 	/* Properly wake up threads that are stuck - revoke(). */
366 	tp->t_revokecnt++;
367 	tty_wakeup(tp, FREAD|FWRITE);
368 	cv_broadcast(&tp->t_bgwait);
369 	cv_broadcast(&tp->t_dcdwait);
370 
371 	ttydev_leave(tp);
372 
373 	return (0);
374 }
375 
376 static __inline int
377 tty_is_ctty(struct tty *tp, struct proc *p)
378 {
379 
380 	tty_lock_assert(tp, MA_OWNED);
381 
382 	return (p->p_session == tp->t_session && p->p_flag & P_CONTROLT);
383 }
384 
385 int
386 tty_wait_background(struct tty *tp, struct thread *td, int sig)
387 {
388 	struct proc *p = td->td_proc;
389 	struct pgrp *pg;
390 	ksiginfo_t ksi;
391 	int error;
392 
393 	MPASS(sig == SIGTTIN || sig == SIGTTOU);
394 	tty_lock_assert(tp, MA_OWNED);
395 
396 	for (;;) {
397 		PROC_LOCK(p);
398 		/*
399 		 * The process should only sleep, when:
400 		 * - This terminal is the controling terminal
401 		 * - Its process group is not the foreground process
402 		 *   group
403 		 * - The parent process isn't waiting for the child to
404 		 *   exit
405 		 * - the signal to send to the process isn't masked
406 		 */
407 		if (!tty_is_ctty(tp, p) || p->p_pgrp == tp->t_pgrp) {
408 			/* Allow the action to happen. */
409 			PROC_UNLOCK(p);
410 			return (0);
411 		}
412 
413 		if (SIGISMEMBER(p->p_sigacts->ps_sigignore, sig) ||
414 		    SIGISMEMBER(td->td_sigmask, sig)) {
415 			/* Only allow them in write()/ioctl(). */
416 			PROC_UNLOCK(p);
417 			return (sig == SIGTTOU ? 0 : EIO);
418 		}
419 
420 		pg = p->p_pgrp;
421 		if (p->p_flag & P_PPWAIT || pg->pg_jobc == 0) {
422 			/* Don't allow the action to happen. */
423 			PROC_UNLOCK(p);
424 			return (EIO);
425 		}
426 		PROC_UNLOCK(p);
427 
428 		/*
429 		 * Send the signal and sleep until we're the new
430 		 * foreground process group.
431 		 */
432 		if (sig != 0) {
433 			ksiginfo_init(&ksi);
434 			ksi.ksi_code = SI_KERNEL;
435 			ksi.ksi_signo = sig;
436 			sig = 0;
437 		}
438 		PGRP_LOCK(pg);
439 		pgsignal(pg, ksi.ksi_signo, 1, &ksi);
440 		PGRP_UNLOCK(pg);
441 
442 		error = tty_wait(tp, &tp->t_bgwait);
443 		if (error)
444 			return (error);
445 	}
446 }
447 
448 static int
449 ttydev_read(struct cdev *dev, struct uio *uio, int ioflag)
450 {
451 	struct tty *tp = dev->si_drv1;
452 	int error;
453 
454 	error = ttydev_enter(tp);
455 	if (error)
456 		goto done;
457 	error = ttydisc_read(tp, uio, ioflag);
458 	tty_unlock(tp);
459 
460 	/*
461 	 * The read() call should not throw an error when the device is
462 	 * being destroyed. Silently convert it to an EOF.
463 	 */
464 done:	if (error == ENXIO)
465 		error = 0;
466 	return (error);
467 }
468 
469 static int
470 ttydev_write(struct cdev *dev, struct uio *uio, int ioflag)
471 {
472 	struct tty *tp = dev->si_drv1;
473 	int error;
474 
475 	error = ttydev_enter(tp);
476 	if (error)
477 		return (error);
478 
479 	if (tp->t_termios.c_lflag & TOSTOP) {
480 		error = tty_wait_background(tp, curthread, SIGTTOU);
481 		if (error)
482 			goto done;
483 	}
484 
485 	if (ioflag & IO_NDELAY && tp->t_flags & TF_BUSY_OUT) {
486 		/* Allow non-blocking writes to bypass serialization. */
487 		error = ttydisc_write(tp, uio, ioflag);
488 	} else {
489 		/* Serialize write() calls. */
490 		while (tp->t_flags & TF_BUSY_OUT) {
491 			error = tty_wait(tp, &tp->t_outserwait);
492 			if (error)
493 				goto done;
494 		}
495 
496 		tp->t_flags |= TF_BUSY_OUT;
497 		error = ttydisc_write(tp, uio, ioflag);
498 		tp->t_flags &= ~TF_BUSY_OUT;
499 		cv_signal(&tp->t_outserwait);
500 	}
501 
502 done:	tty_unlock(tp);
503 	return (error);
504 }
505 
506 static int
507 ttydev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
508     struct thread *td)
509 {
510 	struct tty *tp = dev->si_drv1;
511 	int error;
512 
513 	error = ttydev_enter(tp);
514 	if (error)
515 		return (error);
516 
517 	switch (cmd) {
518 	case TIOCCBRK:
519 	case TIOCCONS:
520 	case TIOCDRAIN:
521 	case TIOCEXCL:
522 	case TIOCFLUSH:
523 	case TIOCNXCL:
524 	case TIOCSBRK:
525 	case TIOCSCTTY:
526 	case TIOCSETA:
527 	case TIOCSETAF:
528 	case TIOCSETAW:
529 	case TIOCSPGRP:
530 	case TIOCSTART:
531 	case TIOCSTAT:
532 	case TIOCSTI:
533 	case TIOCSTOP:
534 	case TIOCSWINSZ:
535 #if 0
536 	case TIOCSDRAINWAIT:
537 	case TIOCSETD:
538 #endif
539 #ifdef COMPAT_43TTY
540 	case  TIOCLBIC:
541 	case  TIOCLBIS:
542 	case  TIOCLSET:
543 	case  TIOCSETC:
544 	case OTIOCSETD:
545 	case  TIOCSETN:
546 	case  TIOCSETP:
547 	case  TIOCSLTC:
548 #endif /* COMPAT_43TTY */
549 		/*
550 		 * If the ioctl() causes the TTY to be modified, let it
551 		 * wait in the background.
552 		 */
553 		error = tty_wait_background(tp, curthread, SIGTTOU);
554 		if (error)
555 			goto done;
556 	}
557 
558 	if (cmd == TIOCSETA || cmd == TIOCSETAW || cmd == TIOCSETAF) {
559 		struct termios *old = &tp->t_termios;
560 		struct termios *new = (struct termios *)data;
561 		struct termios *lock = TTY_CALLOUT(tp, dev) ?
562 		    &tp->t_termios_lock_out : &tp->t_termios_lock_in;
563 		int cc;
564 
565 		/*
566 		 * Lock state devices.  Just overwrite the values of the
567 		 * commands that are currently in use.
568 		 */
569 		new->c_iflag = (old->c_iflag & lock->c_iflag) |
570 		    (new->c_iflag & ~lock->c_iflag);
571 		new->c_oflag = (old->c_oflag & lock->c_oflag) |
572 		    (new->c_oflag & ~lock->c_oflag);
573 		new->c_cflag = (old->c_cflag & lock->c_cflag) |
574 		    (new->c_cflag & ~lock->c_cflag);
575 		new->c_lflag = (old->c_lflag & lock->c_lflag) |
576 		    (new->c_lflag & ~lock->c_lflag);
577 		for (cc = 0; cc < NCCS; ++cc)
578 			if (lock->c_cc[cc])
579 				new->c_cc[cc] = old->c_cc[cc];
580 		if (lock->c_ispeed)
581 			new->c_ispeed = old->c_ispeed;
582 		if (lock->c_ospeed)
583 			new->c_ospeed = old->c_ospeed;
584 	}
585 
586 	error = tty_ioctl(tp, cmd, data, fflag, td);
587 done:	tty_unlock(tp);
588 
589 	return (error);
590 }
591 
592 static int
593 ttydev_poll(struct cdev *dev, int events, struct thread *td)
594 {
595 	struct tty *tp = dev->si_drv1;
596 	int error, revents = 0;
597 
598 	error = ttydev_enter(tp);
599 	if (error)
600 		return ((events & (POLLIN|POLLRDNORM)) | POLLHUP);
601 
602 	if (events & (POLLIN|POLLRDNORM)) {
603 		/* See if we can read something. */
604 		if (ttydisc_read_poll(tp) > 0)
605 			revents |= events & (POLLIN|POLLRDNORM);
606 	}
607 
608 	if (tp->t_flags & TF_ZOMBIE) {
609 		/* Hangup flag on zombie state. */
610 		revents |= POLLHUP;
611 	} else if (events & (POLLOUT|POLLWRNORM)) {
612 		/* See if we can write something. */
613 		if (ttydisc_write_poll(tp) > 0)
614 			revents |= events & (POLLOUT|POLLWRNORM);
615 	}
616 
617 	if (revents == 0) {
618 		if (events & (POLLIN|POLLRDNORM))
619 			selrecord(td, &tp->t_inpoll);
620 		if (events & (POLLOUT|POLLWRNORM))
621 			selrecord(td, &tp->t_outpoll);
622 	}
623 
624 	tty_unlock(tp);
625 
626 	return (revents);
627 }
628 
629 static int
630 ttydev_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
631     int nprot, vm_memattr_t *memattr)
632 {
633 	struct tty *tp = dev->si_drv1;
634 	int error;
635 
636 	/* Handle mmap() through the driver. */
637 
638 	error = ttydev_enter(tp);
639 	if (error)
640 		return (-1);
641 	error = ttydevsw_mmap(tp, offset, paddr, nprot, memattr);
642 	tty_unlock(tp);
643 
644 	return (error);
645 }
646 
647 /*
648  * kqueue support.
649  */
650 
651 static void
652 tty_kqops_read_detach(struct knote *kn)
653 {
654 	struct tty *tp = kn->kn_hook;
655 
656 	knlist_remove(&tp->t_inpoll.si_note, kn, 0);
657 }
658 
659 static int
660 tty_kqops_read_event(struct knote *kn, long hint __unused)
661 {
662 	struct tty *tp = kn->kn_hook;
663 
664 	tty_lock_assert(tp, MA_OWNED);
665 
666 	if (tty_gone(tp) || tp->t_flags & TF_ZOMBIE) {
667 		kn->kn_flags |= EV_EOF;
668 		return (1);
669 	} else {
670 		kn->kn_data = ttydisc_read_poll(tp);
671 		return (kn->kn_data > 0);
672 	}
673 }
674 
675 static void
676 tty_kqops_write_detach(struct knote *kn)
677 {
678 	struct tty *tp = kn->kn_hook;
679 
680 	knlist_remove(&tp->t_outpoll.si_note, kn, 0);
681 }
682 
683 static int
684 tty_kqops_write_event(struct knote *kn, long hint __unused)
685 {
686 	struct tty *tp = kn->kn_hook;
687 
688 	tty_lock_assert(tp, MA_OWNED);
689 
690 	if (tty_gone(tp)) {
691 		kn->kn_flags |= EV_EOF;
692 		return (1);
693 	} else {
694 		kn->kn_data = ttydisc_write_poll(tp);
695 		return (kn->kn_data > 0);
696 	}
697 }
698 
699 static struct filterops tty_kqops_read = {
700 	.f_isfd = 1,
701 	.f_detach = tty_kqops_read_detach,
702 	.f_event = tty_kqops_read_event,
703 };
704 
705 static struct filterops tty_kqops_write = {
706 	.f_isfd = 1,
707 	.f_detach = tty_kqops_write_detach,
708 	.f_event = tty_kqops_write_event,
709 };
710 
711 static int
712 ttydev_kqfilter(struct cdev *dev, struct knote *kn)
713 {
714 	struct tty *tp = dev->si_drv1;
715 	int error;
716 
717 	error = ttydev_enter(tp);
718 	if (error)
719 		return (error);
720 
721 	switch (kn->kn_filter) {
722 	case EVFILT_READ:
723 		kn->kn_hook = tp;
724 		kn->kn_fop = &tty_kqops_read;
725 		knlist_add(&tp->t_inpoll.si_note, kn, 1);
726 		break;
727 	case EVFILT_WRITE:
728 		kn->kn_hook = tp;
729 		kn->kn_fop = &tty_kqops_write;
730 		knlist_add(&tp->t_outpoll.si_note, kn, 1);
731 		break;
732 	default:
733 		error = EINVAL;
734 		break;
735 	}
736 
737 	tty_unlock(tp);
738 	return (error);
739 }
740 
741 static struct cdevsw ttydev_cdevsw = {
742 	.d_version	= D_VERSION,
743 	.d_open		= ttydev_open,
744 	.d_close	= ttydev_close,
745 	.d_read		= ttydev_read,
746 	.d_write	= ttydev_write,
747 	.d_ioctl	= ttydev_ioctl,
748 	.d_kqfilter	= ttydev_kqfilter,
749 	.d_poll		= ttydev_poll,
750 	.d_mmap		= ttydev_mmap,
751 	.d_name		= "ttydev",
752 	.d_flags	= D_TTY,
753 };
754 
755 /*
756  * Init/lock-state devices
757  */
758 
759 static int
760 ttyil_open(struct cdev *dev, int oflags __unused, int devtype __unused,
761     struct thread *td)
762 {
763 	struct tty *tp;
764 	int error;
765 
766 	tp = dev->si_drv1;
767 	error = 0;
768 	tty_lock(tp);
769 	if (tty_gone(tp))
770 		error = ENODEV;
771 	tty_unlock(tp);
772 
773 	return (error);
774 }
775 
776 static int
777 ttyil_close(struct cdev *dev __unused, int flag __unused, int mode __unused,
778     struct thread *td __unused)
779 {
780 
781 	return (0);
782 }
783 
784 static int
785 ttyil_rdwr(struct cdev *dev __unused, struct uio *uio __unused,
786     int ioflag __unused)
787 {
788 
789 	return (ENODEV);
790 }
791 
792 static int
793 ttyil_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
794     struct thread *td)
795 {
796 	struct tty *tp = dev->si_drv1;
797 	int error;
798 
799 	tty_lock(tp);
800 	if (tty_gone(tp)) {
801 		error = ENODEV;
802 		goto done;
803 	}
804 
805 	error = ttydevsw_cioctl(tp, dev2unit(dev), cmd, data, td);
806 	if (error != ENOIOCTL)
807 		goto done;
808 	error = 0;
809 
810 	switch (cmd) {
811 	case TIOCGETA:
812 		/* Obtain terminal flags through tcgetattr(). */
813 		*(struct termios*)data = *(struct termios*)dev->si_drv2;
814 		break;
815 	case TIOCSETA:
816 		/* Set terminal flags through tcsetattr(). */
817 		error = priv_check(td, PRIV_TTY_SETA);
818 		if (error)
819 			break;
820 		*(struct termios*)dev->si_drv2 = *(struct termios*)data;
821 		break;
822 	case TIOCGETD:
823 		*(int *)data = TTYDISC;
824 		break;
825 	case TIOCGWINSZ:
826 		bzero(data, sizeof(struct winsize));
827 		break;
828 	default:
829 		error = ENOTTY;
830 	}
831 
832 done:	tty_unlock(tp);
833 	return (error);
834 }
835 
836 static struct cdevsw ttyil_cdevsw = {
837 	.d_version	= D_VERSION,
838 	.d_open		= ttyil_open,
839 	.d_close	= ttyil_close,
840 	.d_read		= ttyil_rdwr,
841 	.d_write	= ttyil_rdwr,
842 	.d_ioctl	= ttyil_ioctl,
843 	.d_name		= "ttyil",
844 	.d_flags	= D_TTY,
845 };
846 
847 static void
848 tty_init_termios(struct tty *tp)
849 {
850 	struct termios *t = &tp->t_termios_init_in;
851 
852 	t->c_cflag = TTYDEF_CFLAG;
853 	t->c_iflag = TTYDEF_IFLAG;
854 	t->c_lflag = TTYDEF_LFLAG;
855 	t->c_oflag = TTYDEF_OFLAG;
856 	t->c_ispeed = TTYDEF_SPEED;
857 	t->c_ospeed = TTYDEF_SPEED;
858 	memcpy(&t->c_cc, ttydefchars, sizeof ttydefchars);
859 
860 	tp->t_termios_init_out = *t;
861 }
862 
863 void
864 tty_init_console(struct tty *tp, speed_t s)
865 {
866 	struct termios *ti = &tp->t_termios_init_in;
867 	struct termios *to = &tp->t_termios_init_out;
868 
869 	if (s != 0) {
870 		ti->c_ispeed = ti->c_ospeed = s;
871 		to->c_ispeed = to->c_ospeed = s;
872 	}
873 
874 	ti->c_cflag |= CLOCAL;
875 	to->c_cflag |= CLOCAL;
876 }
877 
878 /*
879  * Standard device routine implementations, mostly meant for
880  * pseudo-terminal device drivers. When a driver creates a new terminal
881  * device class, missing routines are patched.
882  */
883 
884 static int
885 ttydevsw_defopen(struct tty *tp __unused)
886 {
887 
888 	return (0);
889 }
890 
891 static void
892 ttydevsw_defclose(struct tty *tp __unused)
893 {
894 
895 }
896 
897 static void
898 ttydevsw_defoutwakeup(struct tty *tp __unused)
899 {
900 
901 	panic("Terminal device has output, while not implemented");
902 }
903 
904 static void
905 ttydevsw_definwakeup(struct tty *tp __unused)
906 {
907 
908 }
909 
910 static int
911 ttydevsw_defioctl(struct tty *tp __unused, u_long cmd __unused,
912     caddr_t data __unused, struct thread *td __unused)
913 {
914 
915 	return (ENOIOCTL);
916 }
917 
918 static int
919 ttydevsw_defcioctl(struct tty *tp __unused, int unit __unused,
920     u_long cmd __unused, caddr_t data __unused, struct thread *td __unused)
921 {
922 
923 	return (ENOIOCTL);
924 }
925 
926 static int
927 ttydevsw_defparam(struct tty *tp __unused, struct termios *t)
928 {
929 
930 	/*
931 	 * Allow the baud rate to be adjusted for pseudo-devices, but at
932 	 * least restrict it to 115200 to prevent excessive buffer
933 	 * usage.  Also disallow 0, to prevent foot shooting.
934 	 */
935 	if (t->c_ispeed < B50)
936 		t->c_ispeed = B50;
937 	else if (t->c_ispeed > B115200)
938 		t->c_ispeed = B115200;
939 	if (t->c_ospeed < B50)
940 		t->c_ospeed = B50;
941 	else if (t->c_ospeed > B115200)
942 		t->c_ospeed = B115200;
943 	t->c_cflag |= CREAD;
944 
945 	return (0);
946 }
947 
948 static int
949 ttydevsw_defmodem(struct tty *tp __unused, int sigon __unused,
950     int sigoff __unused)
951 {
952 
953 	/* Simulate a carrier to make the TTY layer happy. */
954 	return (SER_DCD);
955 }
956 
957 static int
958 ttydevsw_defmmap(struct tty *tp __unused, vm_ooffset_t offset __unused,
959     vm_paddr_t *paddr __unused, int nprot __unused,
960     vm_memattr_t *memattr __unused)
961 {
962 
963 	return (-1);
964 }
965 
966 static void
967 ttydevsw_defpktnotify(struct tty *tp __unused, char event __unused)
968 {
969 
970 }
971 
972 static void
973 ttydevsw_deffree(void *softc __unused)
974 {
975 
976 	panic("Terminal device freed without a free-handler");
977 }
978 
979 static bool
980 ttydevsw_defbusy(struct tty *tp __unused)
981 {
982 
983 	return (FALSE);
984 }
985 
986 /*
987  * TTY allocation and deallocation. TTY devices can be deallocated when
988  * the driver doesn't use it anymore, when the TTY isn't a session's
989  * controlling TTY and when the device node isn't opened through devfs.
990  */
991 
992 struct tty *
993 tty_alloc(struct ttydevsw *tsw, void *sc)
994 {
995 
996 	return (tty_alloc_mutex(tsw, sc, NULL));
997 }
998 
999 struct tty *
1000 tty_alloc_mutex(struct ttydevsw *tsw, void *sc, struct mtx *mutex)
1001 {
1002 	struct tty *tp;
1003 
1004 	/* Make sure the driver defines all routines. */
1005 #define PATCH_FUNC(x) do {				\
1006 	if (tsw->tsw_ ## x == NULL)			\
1007 		tsw->tsw_ ## x = ttydevsw_def ## x;	\
1008 } while (0)
1009 	PATCH_FUNC(open);
1010 	PATCH_FUNC(close);
1011 	PATCH_FUNC(outwakeup);
1012 	PATCH_FUNC(inwakeup);
1013 	PATCH_FUNC(ioctl);
1014 	PATCH_FUNC(cioctl);
1015 	PATCH_FUNC(param);
1016 	PATCH_FUNC(modem);
1017 	PATCH_FUNC(mmap);
1018 	PATCH_FUNC(pktnotify);
1019 	PATCH_FUNC(free);
1020 	PATCH_FUNC(busy);
1021 #undef PATCH_FUNC
1022 
1023 	tp = malloc(sizeof(struct tty), M_TTY, M_WAITOK|M_ZERO);
1024 	tp->t_devsw = tsw;
1025 	tp->t_devswsoftc = sc;
1026 	tp->t_flags = tsw->tsw_flags;
1027 
1028 	tty_init_termios(tp);
1029 
1030 	cv_init(&tp->t_inwait, "ttyin");
1031 	cv_init(&tp->t_outwait, "ttyout");
1032 	cv_init(&tp->t_outserwait, "ttyosr");
1033 	cv_init(&tp->t_bgwait, "ttybg");
1034 	cv_init(&tp->t_dcdwait, "ttydcd");
1035 
1036 	/* Allow drivers to use a custom mutex to lock the TTY. */
1037 	if (mutex != NULL) {
1038 		tp->t_mtx = mutex;
1039 	} else {
1040 		tp->t_mtx = &tp->t_mtxobj;
1041 		mtx_init(&tp->t_mtxobj, "ttymtx", NULL, MTX_DEF);
1042 	}
1043 
1044 	knlist_init_mtx(&tp->t_inpoll.si_note, tp->t_mtx);
1045 	knlist_init_mtx(&tp->t_outpoll.si_note, tp->t_mtx);
1046 
1047 	return (tp);
1048 }
1049 
1050 static void
1051 tty_dealloc(void *arg)
1052 {
1053 	struct tty *tp = arg;
1054 
1055 	/*
1056 	 * ttyydev_leave() usually frees the i/o queues earlier, but it is
1057 	 * not always called between queue allocation and here.  The queues
1058 	 * may be allocated by ioctls on a pty control device without the
1059 	 * corresponding pty slave device ever being open, or after it is
1060 	 * closed.
1061 	 */
1062 	ttyinq_free(&tp->t_inq);
1063 	ttyoutq_free(&tp->t_outq);
1064 	seldrain(&tp->t_inpoll);
1065 	seldrain(&tp->t_outpoll);
1066 	knlist_destroy(&tp->t_inpoll.si_note);
1067 	knlist_destroy(&tp->t_outpoll.si_note);
1068 
1069 	cv_destroy(&tp->t_inwait);
1070 	cv_destroy(&tp->t_outwait);
1071 	cv_destroy(&tp->t_bgwait);
1072 	cv_destroy(&tp->t_dcdwait);
1073 	cv_destroy(&tp->t_outserwait);
1074 
1075 	if (tp->t_mtx == &tp->t_mtxobj)
1076 		mtx_destroy(&tp->t_mtxobj);
1077 	ttydevsw_free(tp);
1078 	free(tp, M_TTY);
1079 }
1080 
1081 static void
1082 tty_rel_free(struct tty *tp)
1083 {
1084 	struct cdev *dev;
1085 
1086 	tty_lock_assert(tp, MA_OWNED);
1087 
1088 #define	TF_ACTIVITY	(TF_GONE|TF_OPENED|TF_HOOK|TF_OPENCLOSE)
1089 	if (tp->t_sessioncnt != 0 || (tp->t_flags & TF_ACTIVITY) != TF_GONE) {
1090 		/* TTY is still in use. */
1091 		tty_unlock(tp);
1092 		return;
1093 	}
1094 
1095 	/* TTY can be deallocated. */
1096 	dev = tp->t_dev;
1097 	tp->t_dev = NULL;
1098 	tty_unlock(tp);
1099 
1100 	if (dev != NULL) {
1101 		sx_xlock(&tty_list_sx);
1102 		TAILQ_REMOVE(&tty_list, tp, t_list);
1103 		tty_list_count--;
1104 		sx_xunlock(&tty_list_sx);
1105 		destroy_dev_sched_cb(dev, tty_dealloc, tp);
1106 	}
1107 }
1108 
1109 void
1110 tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
1111 {
1112 
1113 	MPASS(tp->t_sessioncnt > 0);
1114 	tty_lock_assert(tp, MA_OWNED);
1115 
1116 	if (tp->t_pgrp == pg)
1117 		tp->t_pgrp = NULL;
1118 
1119 	tty_unlock(tp);
1120 }
1121 
1122 void
1123 tty_rel_sess(struct tty *tp, struct session *sess)
1124 {
1125 
1126 	MPASS(tp->t_sessioncnt > 0);
1127 
1128 	/* Current session has left. */
1129 	if (tp->t_session == sess) {
1130 		tp->t_session = NULL;
1131 		MPASS(tp->t_pgrp == NULL);
1132 	}
1133 	tp->t_sessioncnt--;
1134 	tty_rel_free(tp);
1135 }
1136 
1137 void
1138 tty_rel_gone(struct tty *tp)
1139 {
1140 
1141 	MPASS(!tty_gone(tp));
1142 
1143 	/* Simulate carrier removal. */
1144 	ttydisc_modem(tp, 0);
1145 
1146 	/* Wake up all blocked threads. */
1147 	tty_wakeup(tp, FREAD|FWRITE);
1148 	cv_broadcast(&tp->t_bgwait);
1149 	cv_broadcast(&tp->t_dcdwait);
1150 
1151 	tp->t_flags |= TF_GONE;
1152 	tty_rel_free(tp);
1153 }
1154 
1155 /*
1156  * Exposing information about current TTY's through sysctl
1157  */
1158 
1159 static void
1160 tty_to_xtty(struct tty *tp, struct xtty *xt)
1161 {
1162 
1163 	tty_lock_assert(tp, MA_OWNED);
1164 
1165 	xt->xt_size = sizeof(struct xtty);
1166 	xt->xt_insize = ttyinq_getsize(&tp->t_inq);
1167 	xt->xt_incc = ttyinq_bytescanonicalized(&tp->t_inq);
1168 	xt->xt_inlc = ttyinq_bytesline(&tp->t_inq);
1169 	xt->xt_inlow = tp->t_inlow;
1170 	xt->xt_outsize = ttyoutq_getsize(&tp->t_outq);
1171 	xt->xt_outcc = ttyoutq_bytesused(&tp->t_outq);
1172 	xt->xt_outlow = tp->t_outlow;
1173 	xt->xt_column = tp->t_column;
1174 	xt->xt_pgid = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
1175 	xt->xt_sid = tp->t_session ? tp->t_session->s_sid : 0;
1176 	xt->xt_flags = tp->t_flags;
1177 	xt->xt_dev = tp->t_dev ? dev2udev(tp->t_dev) : NODEV;
1178 }
1179 
1180 static int
1181 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
1182 {
1183 	unsigned long lsize;
1184 	struct xtty *xtlist, *xt;
1185 	struct tty *tp;
1186 	int error;
1187 
1188 	sx_slock(&tty_list_sx);
1189 	lsize = tty_list_count * sizeof(struct xtty);
1190 	if (lsize == 0) {
1191 		sx_sunlock(&tty_list_sx);
1192 		return (0);
1193 	}
1194 
1195 	xtlist = xt = malloc(lsize, M_TTY, M_WAITOK);
1196 
1197 	TAILQ_FOREACH(tp, &tty_list, t_list) {
1198 		tty_lock(tp);
1199 		tty_to_xtty(tp, xt);
1200 		tty_unlock(tp);
1201 		xt++;
1202 	}
1203 	sx_sunlock(&tty_list_sx);
1204 
1205 	error = SYSCTL_OUT(req, xtlist, lsize);
1206 	free(xtlist, M_TTY);
1207 	return (error);
1208 }
1209 
1210 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
1211 	0, 0, sysctl_kern_ttys, "S,xtty", "List of TTYs");
1212 
1213 /*
1214  * Device node creation. Device has been set up, now we can expose it to
1215  * the user.
1216  */
1217 
1218 int
1219 tty_makedevf(struct tty *tp, struct ucred *cred, int flags,
1220     const char *fmt, ...)
1221 {
1222 	va_list ap;
1223 	struct make_dev_args args;
1224 	struct cdev *dev, *init, *lock, *cua, *cinit, *clock;
1225 	const char *prefix = "tty";
1226 	char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
1227 	uid_t uid;
1228 	gid_t gid;
1229 	mode_t mode;
1230 	int error;
1231 
1232 	/* Remove "tty" prefix from devices like PTY's. */
1233 	if (tp->t_flags & TF_NOPREFIX)
1234 		prefix = "";
1235 
1236 	va_start(ap, fmt);
1237 	vsnrprintf(name, sizeof name, 32, fmt, ap);
1238 	va_end(ap);
1239 
1240 	if (cred == NULL) {
1241 		/* System device. */
1242 		uid = UID_ROOT;
1243 		gid = GID_WHEEL;
1244 		mode = S_IRUSR|S_IWUSR;
1245 	} else {
1246 		/* User device. */
1247 		uid = cred->cr_ruid;
1248 		gid = GID_TTY;
1249 		mode = S_IRUSR|S_IWUSR|S_IWGRP;
1250 	}
1251 
1252 	flags = flags & TTYMK_CLONING ? MAKEDEV_REF : 0;
1253 	flags |= MAKEDEV_CHECKNAME;
1254 
1255 	/* Master call-in device. */
1256 	make_dev_args_init(&args);
1257 	args.mda_flags = flags;
1258 	args.mda_devsw = &ttydev_cdevsw;
1259 	args.mda_cr = cred;
1260 	args.mda_uid = uid;
1261 	args.mda_gid = gid;
1262 	args.mda_mode = mode;
1263 	args.mda_si_drv1 = tp;
1264 	error = make_dev_s(&args, &dev, "%s%s", prefix, name);
1265 	if (error != 0)
1266 		return (error);
1267 	tp->t_dev = dev;
1268 
1269 	init = lock = cua = cinit = clock = NULL;
1270 
1271 	/* Slave call-in devices. */
1272 	if (tp->t_flags & TF_INITLOCK) {
1273 		args.mda_devsw = &ttyil_cdevsw;
1274 		args.mda_unit = TTYUNIT_INIT;
1275 		args.mda_si_drv1 = tp;
1276 		args.mda_si_drv2 = &tp->t_termios_init_in;
1277 		error = make_dev_s(&args, &init, "%s%s.init", prefix, name);
1278 		if (error != 0)
1279 			goto fail;
1280 		dev_depends(dev, init);
1281 
1282 		args.mda_unit = TTYUNIT_LOCK;
1283 		args.mda_si_drv2 = &tp->t_termios_lock_in;
1284 		error = make_dev_s(&args, &lock, "%s%s.lock", prefix, name);
1285 		if (error != 0)
1286 			goto fail;
1287 		dev_depends(dev, lock);
1288 	}
1289 
1290 	/* Call-out devices. */
1291 	if (tp->t_flags & TF_CALLOUT) {
1292 		make_dev_args_init(&args);
1293 		args.mda_flags = flags;
1294 		args.mda_devsw = &ttydev_cdevsw;
1295 		args.mda_cr = cred;
1296 		args.mda_uid = UID_UUCP;
1297 		args.mda_gid = GID_DIALER;
1298 		args.mda_mode = 0660;
1299 		args.mda_unit = TTYUNIT_CALLOUT;
1300 		args.mda_si_drv1 = tp;
1301 		error = make_dev_s(&args, &cua, "cua%s", name);
1302 		if (error != 0)
1303 			goto fail;
1304 		dev_depends(dev, cua);
1305 
1306 		/* Slave call-out devices. */
1307 		if (tp->t_flags & TF_INITLOCK) {
1308 			args.mda_devsw = &ttyil_cdevsw;
1309 			args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_INIT;
1310 			args.mda_si_drv2 = &tp->t_termios_init_out;
1311 			error = make_dev_s(&args, &cinit, "cua%s.init", name);
1312 			if (error != 0)
1313 				goto fail;
1314 			dev_depends(dev, cinit);
1315 
1316 			args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_LOCK;
1317 			args.mda_si_drv2 = &tp->t_termios_lock_out;
1318 			error = make_dev_s(&args, &clock, "cua%s.lock", name);
1319 			if (error != 0)
1320 				goto fail;
1321 			dev_depends(dev, clock);
1322 		}
1323 	}
1324 
1325 	sx_xlock(&tty_list_sx);
1326 	TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
1327 	tty_list_count++;
1328 	sx_xunlock(&tty_list_sx);
1329 
1330 	return (0);
1331 
1332 fail:
1333 	destroy_dev(dev);
1334 	if (init)
1335 		destroy_dev(init);
1336 	if (lock)
1337 		destroy_dev(lock);
1338 	if (cinit)
1339 		destroy_dev(cinit);
1340 	if (clock)
1341 		destroy_dev(clock);
1342 
1343 	return (error);
1344 }
1345 
1346 /*
1347  * Signalling processes.
1348  */
1349 
1350 void
1351 tty_signal_sessleader(struct tty *tp, int sig)
1352 {
1353 	struct proc *p;
1354 
1355 	tty_lock_assert(tp, MA_OWNED);
1356 	MPASS(sig >= 1 && sig < NSIG);
1357 
1358 	/* Make signals start output again. */
1359 	tp->t_flags &= ~TF_STOPPED;
1360 
1361 	if (tp->t_session != NULL && tp->t_session->s_leader != NULL) {
1362 		p = tp->t_session->s_leader;
1363 		PROC_LOCK(p);
1364 		kern_psignal(p, sig);
1365 		PROC_UNLOCK(p);
1366 	}
1367 }
1368 
1369 void
1370 tty_signal_pgrp(struct tty *tp, int sig)
1371 {
1372 	ksiginfo_t ksi;
1373 
1374 	tty_lock_assert(tp, MA_OWNED);
1375 	MPASS(sig >= 1 && sig < NSIG);
1376 
1377 	/* Make signals start output again. */
1378 	tp->t_flags &= ~TF_STOPPED;
1379 
1380 	if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
1381 		tty_info(tp);
1382 	if (tp->t_pgrp != NULL) {
1383 		ksiginfo_init(&ksi);
1384 		ksi.ksi_signo = sig;
1385 		ksi.ksi_code = SI_KERNEL;
1386 		PGRP_LOCK(tp->t_pgrp);
1387 		pgsignal(tp->t_pgrp, sig, 1, &ksi);
1388 		PGRP_UNLOCK(tp->t_pgrp);
1389 	}
1390 }
1391 
1392 void
1393 tty_wakeup(struct tty *tp, int flags)
1394 {
1395 
1396 	if (tp->t_flags & TF_ASYNC && tp->t_sigio != NULL)
1397 		pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
1398 
1399 	if (flags & FWRITE) {
1400 		cv_broadcast(&tp->t_outwait);
1401 		selwakeup(&tp->t_outpoll);
1402 		KNOTE_LOCKED(&tp->t_outpoll.si_note, 0);
1403 	}
1404 	if (flags & FREAD) {
1405 		cv_broadcast(&tp->t_inwait);
1406 		selwakeup(&tp->t_inpoll);
1407 		KNOTE_LOCKED(&tp->t_inpoll.si_note, 0);
1408 	}
1409 }
1410 
1411 int
1412 tty_wait(struct tty *tp, struct cv *cv)
1413 {
1414 	int error;
1415 	int revokecnt = tp->t_revokecnt;
1416 
1417 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1418 	MPASS(!tty_gone(tp));
1419 
1420 	error = cv_wait_sig(cv, tp->t_mtx);
1421 
1422 	/* Bail out when the device slipped away. */
1423 	if (tty_gone(tp))
1424 		return (ENXIO);
1425 
1426 	/* Restart the system call when we may have been revoked. */
1427 	if (tp->t_revokecnt != revokecnt)
1428 		return (ERESTART);
1429 
1430 	return (error);
1431 }
1432 
1433 int
1434 tty_timedwait(struct tty *tp, struct cv *cv, int hz)
1435 {
1436 	int error;
1437 	int revokecnt = tp->t_revokecnt;
1438 
1439 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1440 	MPASS(!tty_gone(tp));
1441 
1442 	error = cv_timedwait_sig(cv, tp->t_mtx, hz);
1443 
1444 	/* Bail out when the device slipped away. */
1445 	if (tty_gone(tp))
1446 		return (ENXIO);
1447 
1448 	/* Restart the system call when we may have been revoked. */
1449 	if (tp->t_revokecnt != revokecnt)
1450 		return (ERESTART);
1451 
1452 	return (error);
1453 }
1454 
1455 void
1456 tty_flush(struct tty *tp, int flags)
1457 {
1458 
1459 	if (flags & FWRITE) {
1460 		tp->t_flags &= ~TF_HIWAT_OUT;
1461 		ttyoutq_flush(&tp->t_outq);
1462 		tty_wakeup(tp, FWRITE);
1463 		ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
1464 	}
1465 	if (flags & FREAD) {
1466 		tty_hiwat_in_unblock(tp);
1467 		ttyinq_flush(&tp->t_inq);
1468 		ttydevsw_inwakeup(tp);
1469 		ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
1470 	}
1471 }
1472 
1473 void
1474 tty_set_winsize(struct tty *tp, const struct winsize *wsz)
1475 {
1476 
1477 	if (memcmp(&tp->t_winsize, wsz, sizeof(*wsz)) == 0)
1478 		return;
1479 	tp->t_winsize = *wsz;
1480 	tty_signal_pgrp(tp, SIGWINCH);
1481 }
1482 
1483 static int
1484 tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, int fflag,
1485     struct thread *td)
1486 {
1487 	int error;
1488 
1489 	switch (cmd) {
1490 	/*
1491 	 * Modem commands.
1492 	 * The SER_* and TIOCM_* flags are the same, but one bit
1493 	 * shifted. I don't know why.
1494 	 */
1495 	case TIOCSDTR:
1496 		ttydevsw_modem(tp, SER_DTR, 0);
1497 		return (0);
1498 	case TIOCCDTR:
1499 		ttydevsw_modem(tp, 0, SER_DTR);
1500 		return (0);
1501 	case TIOCMSET: {
1502 		int bits = *(int *)data;
1503 		ttydevsw_modem(tp,
1504 		    (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1,
1505 		    ((~bits) & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1506 		return (0);
1507 	}
1508 	case TIOCMBIS: {
1509 		int bits = *(int *)data;
1510 		ttydevsw_modem(tp, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1, 0);
1511 		return (0);
1512 	}
1513 	case TIOCMBIC: {
1514 		int bits = *(int *)data;
1515 		ttydevsw_modem(tp, 0, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1516 		return (0);
1517 	}
1518 	case TIOCMGET:
1519 		*(int *)data = TIOCM_LE + (ttydevsw_modem(tp, 0, 0) << 1);
1520 		return (0);
1521 
1522 	case FIOASYNC:
1523 		if (*(int *)data)
1524 			tp->t_flags |= TF_ASYNC;
1525 		else
1526 			tp->t_flags &= ~TF_ASYNC;
1527 		return (0);
1528 	case FIONBIO:
1529 		/* This device supports non-blocking operation. */
1530 		return (0);
1531 	case FIONREAD:
1532 		*(int *)data = ttyinq_bytescanonicalized(&tp->t_inq);
1533 		return (0);
1534 	case FIONWRITE:
1535 	case TIOCOUTQ:
1536 		*(int *)data = ttyoutq_bytesused(&tp->t_outq);
1537 		return (0);
1538 	case FIOSETOWN:
1539 		if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1540 			/* Not allowed to set ownership. */
1541 			return (ENOTTY);
1542 
1543 		/* Temporarily unlock the TTY to set ownership. */
1544 		tty_unlock(tp);
1545 		error = fsetown(*(int *)data, &tp->t_sigio);
1546 		tty_lock(tp);
1547 		return (error);
1548 	case FIOGETOWN:
1549 		if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1550 			/* Not allowed to set ownership. */
1551 			return (ENOTTY);
1552 
1553 		/* Get ownership. */
1554 		*(int *)data = fgetown(&tp->t_sigio);
1555 		return (0);
1556 	case TIOCGETA:
1557 		/* Obtain terminal flags through tcgetattr(). */
1558 		*(struct termios*)data = tp->t_termios;
1559 		return (0);
1560 	case TIOCSETA:
1561 	case TIOCSETAW:
1562 	case TIOCSETAF: {
1563 		struct termios *t = data;
1564 
1565 		/*
1566 		 * Who makes up these funny rules? According to POSIX,
1567 		 * input baud rate is set equal to the output baud rate
1568 		 * when zero.
1569 		 */
1570 		if (t->c_ispeed == 0)
1571 			t->c_ispeed = t->c_ospeed;
1572 
1573 		/* Discard any unsupported bits. */
1574 		t->c_iflag &= TTYSUP_IFLAG;
1575 		t->c_oflag &= TTYSUP_OFLAG;
1576 		t->c_lflag &= TTYSUP_LFLAG;
1577 		t->c_cflag &= TTYSUP_CFLAG;
1578 
1579 		/* Set terminal flags through tcsetattr(). */
1580 		if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
1581 			error = tty_drain(tp, 0);
1582 			if (error)
1583 				return (error);
1584 			if (cmd == TIOCSETAF)
1585 				tty_flush(tp, FREAD);
1586 		}
1587 
1588 		/*
1589 		 * Only call param() when the flags really change.
1590 		 */
1591 		if ((t->c_cflag & CIGNORE) == 0 &&
1592 		    (tp->t_termios.c_cflag != t->c_cflag ||
1593 		    ((tp->t_termios.c_iflag ^ t->c_iflag) &
1594 		    (IXON|IXOFF|IXANY)) ||
1595 		    tp->t_termios.c_ispeed != t->c_ispeed ||
1596 		    tp->t_termios.c_ospeed != t->c_ospeed)) {
1597 			error = ttydevsw_param(tp, t);
1598 			if (error)
1599 				return (error);
1600 
1601 			/* XXX: CLOCAL? */
1602 
1603 			tp->t_termios.c_cflag = t->c_cflag & ~CIGNORE;
1604 			tp->t_termios.c_ispeed = t->c_ispeed;
1605 			tp->t_termios.c_ospeed = t->c_ospeed;
1606 
1607 			/* Baud rate has changed - update watermarks. */
1608 			tty_watermarks(tp);
1609 		}
1610 
1611 		/* Copy new non-device driver parameters. */
1612 		tp->t_termios.c_iflag = t->c_iflag;
1613 		tp->t_termios.c_oflag = t->c_oflag;
1614 		tp->t_termios.c_lflag = t->c_lflag;
1615 		memcpy(&tp->t_termios.c_cc, t->c_cc, sizeof t->c_cc);
1616 
1617 		ttydisc_optimize(tp);
1618 
1619 		if ((t->c_lflag & ICANON) == 0) {
1620 			/*
1621 			 * When in non-canonical mode, wake up all
1622 			 * readers. Canonicalize any partial input. VMIN
1623 			 * and VTIME could also be adjusted.
1624 			 */
1625 			ttyinq_canonicalize(&tp->t_inq);
1626 			tty_wakeup(tp, FREAD);
1627 		}
1628 
1629 		/*
1630 		 * For packet mode: notify the PTY consumer that VSTOP
1631 		 * and VSTART may have been changed.
1632 		 */
1633 		if (tp->t_termios.c_iflag & IXON &&
1634 		    tp->t_termios.c_cc[VSTOP] == CTRL('S') &&
1635 		    tp->t_termios.c_cc[VSTART] == CTRL('Q'))
1636 			ttydevsw_pktnotify(tp, TIOCPKT_DOSTOP);
1637 		else
1638 			ttydevsw_pktnotify(tp, TIOCPKT_NOSTOP);
1639 		return (0);
1640 	}
1641 	case TIOCGETD:
1642 		/* For compatibility - we only support TTYDISC. */
1643 		*(int *)data = TTYDISC;
1644 		return (0);
1645 	case TIOCGPGRP:
1646 		if (!tty_is_ctty(tp, td->td_proc))
1647 			return (ENOTTY);
1648 
1649 		if (tp->t_pgrp != NULL)
1650 			*(int *)data = tp->t_pgrp->pg_id;
1651 		else
1652 			*(int *)data = NO_PID;
1653 		return (0);
1654 	case TIOCGSID:
1655 		if (!tty_is_ctty(tp, td->td_proc))
1656 			return (ENOTTY);
1657 
1658 		MPASS(tp->t_session);
1659 		*(int *)data = tp->t_session->s_sid;
1660 		return (0);
1661 	case TIOCSCTTY: {
1662 		struct proc *p = td->td_proc;
1663 
1664 		/* XXX: This looks awful. */
1665 		tty_unlock(tp);
1666 		sx_xlock(&proctree_lock);
1667 		tty_lock(tp);
1668 
1669 		if (!SESS_LEADER(p)) {
1670 			/* Only the session leader may do this. */
1671 			sx_xunlock(&proctree_lock);
1672 			return (EPERM);
1673 		}
1674 
1675 		if (tp->t_session != NULL && tp->t_session == p->p_session) {
1676 			/* This is already our controlling TTY. */
1677 			sx_xunlock(&proctree_lock);
1678 			return (0);
1679 		}
1680 
1681 		if (p->p_session->s_ttyp != NULL ||
1682 		    (tp->t_session != NULL && tp->t_session->s_ttyvp != NULL &&
1683 		    tp->t_session->s_ttyvp->v_type != VBAD)) {
1684 			/*
1685 			 * There is already a relation between a TTY and
1686 			 * a session, or the caller is not the session
1687 			 * leader.
1688 			 *
1689 			 * Allow the TTY to be stolen when the vnode is
1690 			 * invalid, but the reference to the TTY is
1691 			 * still active.  This allows immediate reuse of
1692 			 * TTYs of which the session leader has been
1693 			 * killed or the TTY revoked.
1694 			 */
1695 			sx_xunlock(&proctree_lock);
1696 			return (EPERM);
1697 		}
1698 
1699 		/* Connect the session to the TTY. */
1700 		tp->t_session = p->p_session;
1701 		tp->t_session->s_ttyp = tp;
1702 		tp->t_sessioncnt++;
1703 		sx_xunlock(&proctree_lock);
1704 
1705 		/* Assign foreground process group. */
1706 		tp->t_pgrp = p->p_pgrp;
1707 		PROC_LOCK(p);
1708 		p->p_flag |= P_CONTROLT;
1709 		PROC_UNLOCK(p);
1710 
1711 		return (0);
1712 	}
1713 	case TIOCSPGRP: {
1714 		struct pgrp *pg;
1715 
1716 		/*
1717 		 * XXX: Temporarily unlock the TTY to locate the process
1718 		 * group. This code would be lot nicer if we would ever
1719 		 * decompose proctree_lock.
1720 		 */
1721 		tty_unlock(tp);
1722 		sx_slock(&proctree_lock);
1723 		pg = pgfind(*(int *)data);
1724 		if (pg != NULL)
1725 			PGRP_UNLOCK(pg);
1726 		if (pg == NULL || pg->pg_session != td->td_proc->p_session) {
1727 			sx_sunlock(&proctree_lock);
1728 			tty_lock(tp);
1729 			return (EPERM);
1730 		}
1731 		tty_lock(tp);
1732 
1733 		/*
1734 		 * Determine if this TTY is the controlling TTY after
1735 		 * relocking the TTY.
1736 		 */
1737 		if (!tty_is_ctty(tp, td->td_proc)) {
1738 			sx_sunlock(&proctree_lock);
1739 			return (ENOTTY);
1740 		}
1741 		tp->t_pgrp = pg;
1742 		sx_sunlock(&proctree_lock);
1743 
1744 		/* Wake up the background process groups. */
1745 		cv_broadcast(&tp->t_bgwait);
1746 		return (0);
1747 	}
1748 	case TIOCFLUSH: {
1749 		int flags = *(int *)data;
1750 
1751 		if (flags == 0)
1752 			flags = (FREAD|FWRITE);
1753 		else
1754 			flags &= (FREAD|FWRITE);
1755 		tty_flush(tp, flags);
1756 		return (0);
1757 	}
1758 	case TIOCDRAIN:
1759 		/* Drain TTY output. */
1760 		return tty_drain(tp, 0);
1761 	case TIOCCONS:
1762 		/* Set terminal as console TTY. */
1763 		if (*(int *)data) {
1764 			error = priv_check(td, PRIV_TTY_CONSOLE);
1765 			if (error)
1766 				return (error);
1767 
1768 			/*
1769 			 * XXX: constty should really need to be locked!
1770 			 * XXX: allow disconnected constty's to be stolen!
1771 			 */
1772 
1773 			if (constty == tp)
1774 				return (0);
1775 			if (constty != NULL)
1776 				return (EBUSY);
1777 
1778 			tty_unlock(tp);
1779 			constty_set(tp);
1780 			tty_lock(tp);
1781 		} else if (constty == tp) {
1782 			constty_clear();
1783 		}
1784 		return (0);
1785 	case TIOCGWINSZ:
1786 		/* Obtain window size. */
1787 		*(struct winsize*)data = tp->t_winsize;
1788 		return (0);
1789 	case TIOCSWINSZ:
1790 		/* Set window size. */
1791 		tty_set_winsize(tp, data);
1792 		return (0);
1793 	case TIOCEXCL:
1794 		tp->t_flags |= TF_EXCLUDE;
1795 		return (0);
1796 	case TIOCNXCL:
1797 		tp->t_flags &= ~TF_EXCLUDE;
1798 		return (0);
1799 	case TIOCSTOP:
1800 		tp->t_flags |= TF_STOPPED;
1801 		ttydevsw_pktnotify(tp, TIOCPKT_STOP);
1802 		return (0);
1803 	case TIOCSTART:
1804 		tp->t_flags &= ~TF_STOPPED;
1805 		ttydevsw_outwakeup(tp);
1806 		ttydevsw_pktnotify(tp, TIOCPKT_START);
1807 		return (0);
1808 	case TIOCSTAT:
1809 		tty_info(tp);
1810 		return (0);
1811 	case TIOCSTI:
1812 		if ((fflag & FREAD) == 0 && priv_check(td, PRIV_TTY_STI))
1813 			return (EPERM);
1814 		if (!tty_is_ctty(tp, td->td_proc) &&
1815 		    priv_check(td, PRIV_TTY_STI))
1816 			return (EACCES);
1817 		ttydisc_rint(tp, *(char *)data, 0);
1818 		ttydisc_rint_done(tp);
1819 		return (0);
1820 	}
1821 
1822 #ifdef COMPAT_43TTY
1823 	return tty_ioctl_compat(tp, cmd, data, fflag, td);
1824 #else /* !COMPAT_43TTY */
1825 	return (ENOIOCTL);
1826 #endif /* COMPAT_43TTY */
1827 }
1828 
1829 int
1830 tty_ioctl(struct tty *tp, u_long cmd, void *data, int fflag, struct thread *td)
1831 {
1832 	int error;
1833 
1834 	tty_lock_assert(tp, MA_OWNED);
1835 
1836 	if (tty_gone(tp))
1837 		return (ENXIO);
1838 
1839 	error = ttydevsw_ioctl(tp, cmd, data, td);
1840 	if (error == ENOIOCTL)
1841 		error = tty_generic_ioctl(tp, cmd, data, fflag, td);
1842 
1843 	return (error);
1844 }
1845 
1846 dev_t
1847 tty_udev(struct tty *tp)
1848 {
1849 
1850 	if (tp->t_dev)
1851 		return (dev2udev(tp->t_dev));
1852 	else
1853 		return (NODEV);
1854 }
1855 
1856 int
1857 tty_checkoutq(struct tty *tp)
1858 {
1859 
1860 	/* 256 bytes should be enough to print a log message. */
1861 	return (ttyoutq_bytesleft(&tp->t_outq) >= 256);
1862 }
1863 
1864 void
1865 tty_hiwat_in_block(struct tty *tp)
1866 {
1867 
1868 	if ((tp->t_flags & TF_HIWAT_IN) == 0 &&
1869 	    tp->t_termios.c_iflag & IXOFF &&
1870 	    tp->t_termios.c_cc[VSTOP] != _POSIX_VDISABLE) {
1871 		/*
1872 		 * Input flow control. Only enter the high watermark when we
1873 		 * can successfully store the VSTOP character.
1874 		 */
1875 		if (ttyoutq_write_nofrag(&tp->t_outq,
1876 		    &tp->t_termios.c_cc[VSTOP], 1) == 0)
1877 			tp->t_flags |= TF_HIWAT_IN;
1878 	} else {
1879 		/* No input flow control. */
1880 		tp->t_flags |= TF_HIWAT_IN;
1881 	}
1882 }
1883 
1884 void
1885 tty_hiwat_in_unblock(struct tty *tp)
1886 {
1887 
1888 	if (tp->t_flags & TF_HIWAT_IN &&
1889 	    tp->t_termios.c_iflag & IXOFF &&
1890 	    tp->t_termios.c_cc[VSTART] != _POSIX_VDISABLE) {
1891 		/*
1892 		 * Input flow control. Only leave the high watermark when we
1893 		 * can successfully store the VSTART character.
1894 		 */
1895 		if (ttyoutq_write_nofrag(&tp->t_outq,
1896 		    &tp->t_termios.c_cc[VSTART], 1) == 0)
1897 			tp->t_flags &= ~TF_HIWAT_IN;
1898 	} else {
1899 		/* No input flow control. */
1900 		tp->t_flags &= ~TF_HIWAT_IN;
1901 	}
1902 
1903 	if (!tty_gone(tp))
1904 		ttydevsw_inwakeup(tp);
1905 }
1906 
1907 /*
1908  * TTY hooks interface.
1909  */
1910 
1911 static int
1912 ttyhook_defrint(struct tty *tp, char c, int flags)
1913 {
1914 
1915 	if (ttyhook_rint_bypass(tp, &c, 1) != 1)
1916 		return (-1);
1917 
1918 	return (0);
1919 }
1920 
1921 int
1922 ttyhook_register(struct tty **rtp, struct proc *p, int fd, struct ttyhook *th,
1923     void *softc)
1924 {
1925 	struct tty *tp;
1926 	struct file *fp;
1927 	struct cdev *dev;
1928 	struct cdevsw *cdp;
1929 	struct filedesc *fdp;
1930 	cap_rights_t rights;
1931 	int error, ref;
1932 
1933 	/* Validate the file descriptor. */
1934 	fdp = p->p_fd;
1935 	error = fget_unlocked(fdp, fd, cap_rights_init(&rights, CAP_TTYHOOK),
1936 	    &fp, NULL);
1937 	if (error != 0)
1938 		return (error);
1939 	if (fp->f_ops == &badfileops) {
1940 		error = EBADF;
1941 		goto done1;
1942 	}
1943 
1944 	/*
1945 	 * Make sure the vnode is bound to a character device.
1946 	 * Unlocked check for the vnode type is ok there, because we
1947 	 * only shall prevent calling devvn_refthread on the file that
1948 	 * never has been opened over a character device.
1949 	 */
1950 	if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR) {
1951 		error = EINVAL;
1952 		goto done1;
1953 	}
1954 
1955 	/* Make sure it is a TTY. */
1956 	cdp = devvn_refthread(fp->f_vnode, &dev, &ref);
1957 	if (cdp == NULL) {
1958 		error = ENXIO;
1959 		goto done1;
1960 	}
1961 	if (dev != fp->f_data) {
1962 		error = ENXIO;
1963 		goto done2;
1964 	}
1965 	if (cdp != &ttydev_cdevsw) {
1966 		error = ENOTTY;
1967 		goto done2;
1968 	}
1969 	tp = dev->si_drv1;
1970 
1971 	/* Try to attach the hook to the TTY. */
1972 	error = EBUSY;
1973 	tty_lock(tp);
1974 	MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
1975 	if (tp->t_flags & TF_HOOK)
1976 		goto done3;
1977 
1978 	tp->t_flags |= TF_HOOK;
1979 	tp->t_hook = th;
1980 	tp->t_hooksoftc = softc;
1981 	*rtp = tp;
1982 	error = 0;
1983 
1984 	/* Maybe we can switch into bypass mode now. */
1985 	ttydisc_optimize(tp);
1986 
1987 	/* Silently convert rint() calls to rint_bypass() when possible. */
1988 	if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
1989 		th->th_rint = ttyhook_defrint;
1990 
1991 done3:	tty_unlock(tp);
1992 done2:	dev_relthread(dev, ref);
1993 done1:	fdrop(fp, curthread);
1994 	return (error);
1995 }
1996 
1997 void
1998 ttyhook_unregister(struct tty *tp)
1999 {
2000 
2001 	tty_lock_assert(tp, MA_OWNED);
2002 	MPASS(tp->t_flags & TF_HOOK);
2003 
2004 	/* Disconnect the hook. */
2005 	tp->t_flags &= ~TF_HOOK;
2006 	tp->t_hook = NULL;
2007 
2008 	/* Maybe we need to leave bypass mode. */
2009 	ttydisc_optimize(tp);
2010 
2011 	/* Maybe deallocate the TTY as well. */
2012 	tty_rel_free(tp);
2013 }
2014 
2015 /*
2016  * /dev/console handling.
2017  */
2018 
2019 static int
2020 ttyconsdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
2021 {
2022 	struct tty *tp;
2023 
2024 	/* System has no console device. */
2025 	if (dev_console_filename == NULL)
2026 		return (ENXIO);
2027 
2028 	/* Look up corresponding TTY by device name. */
2029 	sx_slock(&tty_list_sx);
2030 	TAILQ_FOREACH(tp, &tty_list, t_list) {
2031 		if (strcmp(dev_console_filename, tty_devname(tp)) == 0) {
2032 			dev_console->si_drv1 = tp;
2033 			break;
2034 		}
2035 	}
2036 	sx_sunlock(&tty_list_sx);
2037 
2038 	/* System console has no TTY associated. */
2039 	if (dev_console->si_drv1 == NULL)
2040 		return (ENXIO);
2041 
2042 	return (ttydev_open(dev, oflags, devtype, td));
2043 }
2044 
2045 static int
2046 ttyconsdev_write(struct cdev *dev, struct uio *uio, int ioflag)
2047 {
2048 
2049 	log_console(uio);
2050 
2051 	return (ttydev_write(dev, uio, ioflag));
2052 }
2053 
2054 /*
2055  * /dev/console is a little different than normal TTY's.  When opened,
2056  * it determines which TTY to use.  When data gets written to it, it
2057  * will be logged in the kernel message buffer.
2058  */
2059 static struct cdevsw ttyconsdev_cdevsw = {
2060 	.d_version	= D_VERSION,
2061 	.d_open		= ttyconsdev_open,
2062 	.d_close	= ttydev_close,
2063 	.d_read		= ttydev_read,
2064 	.d_write	= ttyconsdev_write,
2065 	.d_ioctl	= ttydev_ioctl,
2066 	.d_kqfilter	= ttydev_kqfilter,
2067 	.d_poll		= ttydev_poll,
2068 	.d_mmap		= ttydev_mmap,
2069 	.d_name		= "ttyconsdev",
2070 	.d_flags	= D_TTY,
2071 };
2072 
2073 static void
2074 ttyconsdev_init(void *unused __unused)
2075 {
2076 
2077 	dev_console = make_dev_credf(MAKEDEV_ETERNAL, &ttyconsdev_cdevsw, 0,
2078 	    NULL, UID_ROOT, GID_WHEEL, 0600, "console");
2079 }
2080 
2081 SYSINIT(tty, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyconsdev_init, NULL);
2082 
2083 void
2084 ttyconsdev_select(const char *name)
2085 {
2086 
2087 	dev_console_filename = name;
2088 }
2089 
2090 /*
2091  * Debugging routines.
2092  */
2093 
2094 #include "opt_ddb.h"
2095 #ifdef DDB
2096 #include <ddb/ddb.h>
2097 #include <ddb/db_sym.h>
2098 
2099 static const struct {
2100 	int flag;
2101 	char val;
2102 } ttystates[] = {
2103 #if 0
2104 	{ TF_NOPREFIX,		'N' },
2105 #endif
2106 	{ TF_INITLOCK,		'I' },
2107 	{ TF_CALLOUT,		'C' },
2108 
2109 	/* Keep these together -> 'Oi' and 'Oo'. */
2110 	{ TF_OPENED,		'O' },
2111 	{ TF_OPENED_IN,		'i' },
2112 	{ TF_OPENED_OUT,	'o' },
2113 	{ TF_OPENED_CONS,	'c' },
2114 
2115 	{ TF_GONE,		'G' },
2116 	{ TF_OPENCLOSE,		'B' },
2117 	{ TF_ASYNC,		'Y' },
2118 	{ TF_LITERAL,		'L' },
2119 
2120 	/* Keep these together -> 'Hi' and 'Ho'. */
2121 	{ TF_HIWAT,		'H' },
2122 	{ TF_HIWAT_IN,		'i' },
2123 	{ TF_HIWAT_OUT,		'o' },
2124 
2125 	{ TF_STOPPED,		'S' },
2126 	{ TF_EXCLUDE,		'X' },
2127 	{ TF_BYPASS,		'l' },
2128 	{ TF_ZOMBIE,		'Z' },
2129 	{ TF_HOOK,		's' },
2130 
2131 	/* Keep these together -> 'bi' and 'bo'. */
2132 	{ TF_BUSY,		'b' },
2133 	{ TF_BUSY_IN,		'i' },
2134 	{ TF_BUSY_OUT,		'o' },
2135 
2136 	{ 0,			'\0'},
2137 };
2138 
2139 #define	TTY_FLAG_BITS \
2140 	"\20\1NOPREFIX\2INITLOCK\3CALLOUT\4OPENED_IN" \
2141 	"\5OPENED_OUT\6OPENED_CONS\7GONE\10OPENCLOSE" \
2142 	"\11ASYNC\12LITERAL\13HIWAT_IN\14HIWAT_OUT" \
2143 	"\15STOPPED\16EXCLUDE\17BYPASS\20ZOMBIE" \
2144 	"\21HOOK\22BUSY_IN\23BUSY_OUT"
2145 
2146 #define DB_PRINTSYM(name, addr) \
2147 	db_printf("%s  " #name ": ", sep); \
2148 	db_printsym((db_addr_t) addr, DB_STGY_ANY); \
2149 	db_printf("\n");
2150 
2151 static void
2152 _db_show_devsw(const char *sep, const struct ttydevsw *tsw)
2153 {
2154 
2155 	db_printf("%sdevsw: ", sep);
2156 	db_printsym((db_addr_t)tsw, DB_STGY_ANY);
2157 	db_printf(" (%p)\n", tsw);
2158 	DB_PRINTSYM(open, tsw->tsw_open);
2159 	DB_PRINTSYM(close, tsw->tsw_close);
2160 	DB_PRINTSYM(outwakeup, tsw->tsw_outwakeup);
2161 	DB_PRINTSYM(inwakeup, tsw->tsw_inwakeup);
2162 	DB_PRINTSYM(ioctl, tsw->tsw_ioctl);
2163 	DB_PRINTSYM(param, tsw->tsw_param);
2164 	DB_PRINTSYM(modem, tsw->tsw_modem);
2165 	DB_PRINTSYM(mmap, tsw->tsw_mmap);
2166 	DB_PRINTSYM(pktnotify, tsw->tsw_pktnotify);
2167 	DB_PRINTSYM(free, tsw->tsw_free);
2168 }
2169 
2170 static void
2171 _db_show_hooks(const char *sep, const struct ttyhook *th)
2172 {
2173 
2174 	db_printf("%shook: ", sep);
2175 	db_printsym((db_addr_t)th, DB_STGY_ANY);
2176 	db_printf(" (%p)\n", th);
2177 	if (th == NULL)
2178 		return;
2179 	DB_PRINTSYM(rint, th->th_rint);
2180 	DB_PRINTSYM(rint_bypass, th->th_rint_bypass);
2181 	DB_PRINTSYM(rint_done, th->th_rint_done);
2182 	DB_PRINTSYM(rint_poll, th->th_rint_poll);
2183 	DB_PRINTSYM(getc_inject, th->th_getc_inject);
2184 	DB_PRINTSYM(getc_capture, th->th_getc_capture);
2185 	DB_PRINTSYM(getc_poll, th->th_getc_poll);
2186 	DB_PRINTSYM(close, th->th_close);
2187 }
2188 
2189 static void
2190 _db_show_termios(const char *name, const struct termios *t)
2191 {
2192 
2193 	db_printf("%s: iflag 0x%x oflag 0x%x cflag 0x%x "
2194 	    "lflag 0x%x ispeed %u ospeed %u\n", name,
2195 	    t->c_iflag, t->c_oflag, t->c_cflag, t->c_lflag,
2196 	    t->c_ispeed, t->c_ospeed);
2197 }
2198 
2199 /* DDB command to show TTY statistics. */
2200 DB_SHOW_COMMAND(tty, db_show_tty)
2201 {
2202 	struct tty *tp;
2203 
2204 	if (!have_addr) {
2205 		db_printf("usage: show tty <addr>\n");
2206 		return;
2207 	}
2208 	tp = (struct tty *)addr;
2209 
2210 	db_printf("%p: %s\n", tp, tty_devname(tp));
2211 	db_printf("\tmtx: %p\n", tp->t_mtx);
2212 	db_printf("\tflags: 0x%b\n", tp->t_flags, TTY_FLAG_BITS);
2213 	db_printf("\trevokecnt: %u\n", tp->t_revokecnt);
2214 
2215 	/* Buffering mechanisms. */
2216 	db_printf("\tinq: %p begin %u linestart %u reprint %u end %u "
2217 	    "nblocks %u quota %u\n", &tp->t_inq, tp->t_inq.ti_begin,
2218 	    tp->t_inq.ti_linestart, tp->t_inq.ti_reprint, tp->t_inq.ti_end,
2219 	    tp->t_inq.ti_nblocks, tp->t_inq.ti_quota);
2220 	db_printf("\toutq: %p begin %u end %u nblocks %u quota %u\n",
2221 	    &tp->t_outq, tp->t_outq.to_begin, tp->t_outq.to_end,
2222 	    tp->t_outq.to_nblocks, tp->t_outq.to_quota);
2223 	db_printf("\tinlow: %zu\n", tp->t_inlow);
2224 	db_printf("\toutlow: %zu\n", tp->t_outlow);
2225 	_db_show_termios("\ttermios", &tp->t_termios);
2226 	db_printf("\twinsize: row %u col %u xpixel %u ypixel %u\n",
2227 	    tp->t_winsize.ws_row, tp->t_winsize.ws_col,
2228 	    tp->t_winsize.ws_xpixel, tp->t_winsize.ws_ypixel);
2229 	db_printf("\tcolumn: %u\n", tp->t_column);
2230 	db_printf("\twritepos: %u\n", tp->t_writepos);
2231 	db_printf("\tcompatflags: 0x%x\n", tp->t_compatflags);
2232 
2233 	/* Init/lock-state devices. */
2234 	_db_show_termios("\ttermios_init_in", &tp->t_termios_init_in);
2235 	_db_show_termios("\ttermios_init_out", &tp->t_termios_init_out);
2236 	_db_show_termios("\ttermios_lock_in", &tp->t_termios_lock_in);
2237 	_db_show_termios("\ttermios_lock_out", &tp->t_termios_lock_out);
2238 
2239 	/* Hooks */
2240 	_db_show_devsw("\t", tp->t_devsw);
2241 	_db_show_hooks("\t", tp->t_hook);
2242 
2243 	/* Process info. */
2244 	db_printf("\tpgrp: %p gid %d jobc %d\n", tp->t_pgrp,
2245 	    tp->t_pgrp ? tp->t_pgrp->pg_id : 0,
2246 	    tp->t_pgrp ? tp->t_pgrp->pg_jobc : 0);
2247 	db_printf("\tsession: %p", tp->t_session);
2248 	if (tp->t_session != NULL)
2249 	    db_printf(" count %u leader %p tty %p sid %d login %s",
2250 		tp->t_session->s_count, tp->t_session->s_leader,
2251 		tp->t_session->s_ttyp, tp->t_session->s_sid,
2252 		tp->t_session->s_login);
2253 	db_printf("\n");
2254 	db_printf("\tsessioncnt: %u\n", tp->t_sessioncnt);
2255 	db_printf("\tdevswsoftc: %p\n", tp->t_devswsoftc);
2256 	db_printf("\thooksoftc: %p\n", tp->t_hooksoftc);
2257 	db_printf("\tdev: %p\n", tp->t_dev);
2258 }
2259 
2260 /* DDB command to list TTYs. */
2261 DB_SHOW_ALL_COMMAND(ttys, db_show_all_ttys)
2262 {
2263 	struct tty *tp;
2264 	size_t isiz, osiz;
2265 	int i, j;
2266 
2267 	/* Make the output look like `pstat -t'. */
2268 	db_printf("PTR        ");
2269 #if defined(__LP64__)
2270 	db_printf("        ");
2271 #endif
2272 	db_printf("      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   "
2273 	    "COL  SESS  PGID STATE\n");
2274 
2275 	TAILQ_FOREACH(tp, &tty_list, t_list) {
2276 		isiz = tp->t_inq.ti_nblocks * TTYINQ_DATASIZE;
2277 		osiz = tp->t_outq.to_nblocks * TTYOUTQ_DATASIZE;
2278 
2279 		db_printf("%p %10s %5zu %4u %4u %4zu %5zu %4u %4zu %5u %5d "
2280 		    "%5d ", tp, tty_devname(tp), isiz,
2281 		    tp->t_inq.ti_linestart - tp->t_inq.ti_begin,
2282 		    tp->t_inq.ti_end - tp->t_inq.ti_linestart,
2283 		    isiz - tp->t_inlow, osiz,
2284 		    tp->t_outq.to_end - tp->t_outq.to_begin,
2285 		    osiz - tp->t_outlow, MIN(tp->t_column, 99999),
2286 		    tp->t_session ? tp->t_session->s_sid : 0,
2287 		    tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
2288 
2289 		/* Flag bits. */
2290 		for (i = j = 0; ttystates[i].flag; i++)
2291 			if (tp->t_flags & ttystates[i].flag) {
2292 				db_printf("%c", ttystates[i].val);
2293 				j++;
2294 			}
2295 		if (j == 0)
2296 			db_printf("-");
2297 		db_printf("\n");
2298 	}
2299 }
2300 #endif /* DDB */
2301