xref: /freebsd/sys/kern/tty.c (revision 420428718da769ea72d3f18ed8eba7c3d998b1c8)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Portions of this software were developed under sponsorship from Snow
8  * B.V., the Netherlands.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #include "opt_capsicum.h"
34 #include "opt_printf.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/jail.h>
48 #include <sys/kernel.h>
49 #include <sys/limits.h>
50 #include <sys/malloc.h>
51 #include <sys/mount.h>
52 #include <sys/poll.h>
53 #include <sys/priv.h>
54 #include <sys/proc.h>
55 #include <sys/serial.h>
56 #include <sys/signal.h>
57 #include <sys/stat.h>
58 #include <sys/stdarg.h>
59 #include <sys/sx.h>
60 #include <sys/sysctl.h>
61 #include <sys/systm.h>
62 #include <sys/tty.h>
63 #include <sys/ttycom.h>
64 #define TTYDEFCHARS
65 #include <sys/ttydefaults.h>
66 #undef TTYDEFCHARS
67 #include <sys/ucred.h>
68 #include <sys/vnode.h>
69 #define EXTERR_CATEGORY EXTERR_CAT_TTY
70 #include <sys/exterrvar.h>
71 
72 #include <fs/devfs/devfs.h>
73 
74 static MALLOC_DEFINE(M_TTY, "tty", "tty device");
75 
76 static void tty_rel_free(struct tty *tp, bool inttydevclose);
77 static int tty_wait_proctree(struct tty *tp, struct cv *cv,
78     int proctree_lock_mode);
79 
80 static TAILQ_HEAD(, tty) tty_list = TAILQ_HEAD_INITIALIZER(tty_list);
81 static struct sx tty_list_sx;
82 SX_SYSINIT(tty_list, &tty_list_sx, "tty list");
83 static unsigned int tty_list_count = 0;
84 
85 /* Character device of /dev/console. */
86 static struct cdev	*dev_console;
87 static const char	*dev_console_filename;
88 
89 /*
90  * Flags that are supported and stored by this implementation.
91  */
92 #define TTYSUP_IFLAG	(IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK|ISTRIP|INLCR|\
93 			IGNCR|ICRNL|IXON|IXOFF|IXANY|IMAXBEL|IUTF8)
94 #define TTYSUP_OFLAG	(OPOST|ONLCR|TAB3|ONOEOT|OCRNL|ONOCR|ONLRET)
95 #define TTYSUP_LFLAG	(ECHOKE|ECHOE|ECHOK|ECHO|ECHONL|ECHOPRT|\
96 			ECHOCTL|ISIG|ICANON|ALTWERASE|IEXTEN|TOSTOP|\
97 			FLUSHO|NOKERNINFO|NOFLSH)
98 #define TTYSUP_CFLAG	(CIGNORE|CSIZE|CSTOPB|CREAD|PARENB|PARODD|\
99 			HUPCL|CLOCAL|CCTS_OFLOW|CRTS_IFLOW|CDTR_IFLOW|\
100 			CDSR_OFLOW|CCAR_OFLOW|CNO_RTSDTR)
101 
102 #define	TTY_CALLOUT(tp,d) (dev2unit(d) & TTYUNIT_CALLOUT)
103 
104 static int  tty_drainwait = 5 * 60;
105 SYSCTL_INT(_kern, OID_AUTO, tty_drainwait, CTLFLAG_RWTUN,
106     &tty_drainwait, 0, "Default output drain timeout in seconds");
107 
108 static bool tty_tiocsti = true;
109 SYSCTL_BOOL(_security_bsd, OID_AUTO, allow_tiocsti, CTLFLAG_RWTUN,
110     &tty_tiocsti, 0, "Allow TIOCSTI ioctl");
111 
112 /*
113  * Set TTY buffer sizes.
114  */
115 
116 #define	TTYBUF_MAX	65536
117 
118 #ifdef PRINTF_BUFR_SIZE
119 #define	TTY_PRBUF_SIZE	PRINTF_BUFR_SIZE
120 #else
121 #define	TTY_PRBUF_SIZE	256
122 #endif
123 
124 /*
125  * Allocate buffer space if necessary, and set low watermarks, based on speed.
126  * Note that the ttyxxxq_setsize() functions may drop and then reacquire the tty
127  * lock during memory allocation.  They will return ENXIO if the tty disappears
128  * while unlocked.
129  */
130 static int
tty_watermarks(struct tty * tp)131 tty_watermarks(struct tty *tp)
132 {
133 	size_t bs = 0;
134 	int error;
135 
136 	/* Provide an input buffer for 2 seconds of data. */
137 	if (tp->t_termios.c_cflag & CREAD)
138 		bs = MIN(tp->t_termios.c_ispeed / 5, TTYBUF_MAX);
139 	error = ttyinq_setsize(&tp->t_inq, tp, bs);
140 	if (error != 0)
141 		return (error);
142 
143 	/* Set low watermark at 10% (when 90% is available). */
144 	tp->t_inlow = (ttyinq_getallocatedsize(&tp->t_inq) * 9) / 10;
145 
146 	/* Provide an output buffer for 2 seconds of data. */
147 	bs = MIN(tp->t_termios.c_ospeed / 5, TTYBUF_MAX);
148 	error = ttyoutq_setsize(&tp->t_outq, tp, bs);
149 	if (error != 0)
150 		return (error);
151 
152 	/* Set low watermark at 10% (when 90% is available). */
153 	tp->t_outlow = (ttyoutq_getallocatedsize(&tp->t_outq) * 9) / 10;
154 
155 	return (0);
156 }
157 
158 static int
tty_drain(struct tty * tp,int leaving)159 tty_drain(struct tty *tp, int leaving)
160 {
161 	sbintime_t timeout_at;
162 	size_t bytes;
163 	int error;
164 
165 	if (ttyhook_hashook(tp, getc_inject))
166 		/* buffer is inaccessible */
167 		return (0);
168 
169 	/*
170 	 * For close(), use the recent historic timeout of "1 second without
171 	 * making progress".  For tcdrain(), use t_drainwait as the timeout,
172 	 * with zero meaning "no timeout" which gives POSIX behavior.
173 	 */
174 	if (leaving)
175 		timeout_at = getsbinuptime() + SBT_1S;
176 	else if (tp->t_drainwait != 0)
177 		timeout_at = getsbinuptime() + SBT_1S * tp->t_drainwait;
178 	else
179 		timeout_at = 0;
180 
181 	/*
182 	 * Poll the output buffer and the hardware for completion, at 10 Hz.
183 	 * Polling is required for devices which are not able to signal an
184 	 * interrupt when the transmitter becomes idle (most USB serial devs).
185 	 * The unusual structure of this loop ensures we check for busy one more
186 	 * time after tty_timedwait() returns EWOULDBLOCK, so that success has
187 	 * higher priority than timeout if the IO completed in the last 100mS.
188 	 */
189 	error = 0;
190 	bytes = ttyoutq_bytesused(&tp->t_outq);
191 	for (;;) {
192 		if (ttyoutq_bytesused(&tp->t_outq) == 0 && !ttydevsw_busy(tp))
193 			return (0);
194 		if (error != 0)
195 			return (error);
196 		ttydevsw_outwakeup(tp);
197 		error = tty_timedwait(tp, &tp->t_outwait, hz / 10);
198 		if (error != 0 && error != EWOULDBLOCK)
199 			return (error);
200 		else if (timeout_at == 0 || getsbinuptime() < timeout_at)
201 			error = 0;
202 		else if (leaving && ttyoutq_bytesused(&tp->t_outq) < bytes) {
203 			/* In close, making progress, grant an extra second. */
204 			error = 0;
205 			timeout_at += SBT_1S;
206 			bytes = ttyoutq_bytesused(&tp->t_outq);
207 		}
208 	}
209 }
210 
211 /*
212  * Though ttydev_enter() and ttydev_leave() seem to be related, they
213  * don't have to be used together. ttydev_enter() is used by the cdev
214  * operations to prevent an actual operation from being processed when
215  * the TTY has been abandoned. ttydev_leave() is used by ttydev_open()
216  * and ttydev_close() to determine whether per-TTY data should be
217  * deallocated.
218  */
219 
220 static __inline int
ttydev_enter(struct tty * tp)221 ttydev_enter(struct tty *tp)
222 {
223 
224 	tty_lock(tp);
225 
226 	if (tty_gone(tp) || !tty_opened(tp)) {
227 		/* Device is already gone. */
228 		tty_unlock(tp);
229 		return (EXTERROR(ENXIO, "ttydev_enter: device is gone"));
230 	}
231 
232 	return (0);
233 }
234 
235 static void
ttydev_leave(struct tty * tp,bool inttydevclose)236 ttydev_leave(struct tty *tp, bool inttydevclose)
237 {
238 
239 	tty_assert_locked(tp);
240 
241 	if (tty_opened(tp) || tp->t_flags & TF_OPENCLOSE) {
242 		/* Device is still opened somewhere. */
243 		if (inttydevclose)
244 			tp->t_flags &= ~TF_INDEVCLOSE;
245 		tty_unlock(tp);
246 		return;
247 	}
248 
249 	tp->t_flags |= TF_OPENCLOSE;
250 
251 	/* Remove console TTY. */
252 	constty_clear(tp);
253 
254 	/* Drain any output. */
255 	if (!tty_gone(tp))
256 		tty_drain(tp, 1);
257 
258 	ttydisc_close(tp);
259 
260 	/* Free i/o queues now since they might be large. */
261 	ttyinq_free(&tp->t_inq);
262 	tp->t_inlow = 0;
263 	ttyoutq_free(&tp->t_outq);
264 	tp->t_outlow = 0;
265 
266 	if (!tty_gone(tp))
267 		ttydevsw_close(tp);
268 
269 	tp->t_flags &= ~TF_OPENCLOSE;
270 	cv_broadcast(&tp->t_dcdwait);
271 	tty_rel_free(tp, inttydevclose);
272 }
273 
274 /*
275  * Operations that are exposed through the character device in /dev.
276  */
277 static int
ttydev_open(struct cdev * dev,int oflags,int devtype __unused,struct thread * td)278 ttydev_open(struct cdev *dev, int oflags, int devtype __unused,
279     struct thread *td)
280 {
281 	struct tty *tp;
282 	int error;
283 
284 	tp = dev->si_drv1;
285 	error = 0;
286 	tty_lock(tp);
287 	if (tty_gone(tp)) {
288 		/* Device is already gone. */
289 		tty_unlock(tp);
290 		return (EXTERROR(ENXIO, "ttydev_open: device is gone"));
291 	}
292 
293 	/*
294 	 * Block when other processes are currently opening or closing
295 	 * the TTY.
296 	 */
297 	while (tp->t_flags & TF_OPENCLOSE) {
298 		error = tty_wait(tp, &tp->t_dcdwait);
299 		if (error != 0) {
300 			tty_unlock(tp);
301 			return (error);
302 		}
303 	}
304 	tp->t_flags |= TF_OPENCLOSE;
305 
306 	/*
307 	 * Make sure the "tty" and "cua" device cannot be opened at the
308 	 * same time.  The console is a "tty" device.
309 	 */
310 	if (TTY_CALLOUT(tp, dev)) {
311 		if (tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) {
312 			error = EBUSY;
313 			goto done;
314 		}
315 	} else {
316 		if (tp->t_flags & TF_OPENED_OUT) {
317 			error = EBUSY;
318 			goto done;
319 		}
320 	}
321 
322 	if (tp->t_flags & TF_EXCLUDE && priv_check(td, PRIV_TTY_EXCLUSIVE)) {
323 		error = EBUSY;
324 		goto done;
325 	}
326 
327 	if (!tty_opened(tp)) {
328 		/* Set proper termios flags. */
329 		if (TTY_CALLOUT(tp, dev))
330 			tp->t_termios = tp->t_termios_init_out;
331 		else
332 			tp->t_termios = tp->t_termios_init_in;
333 		ttydevsw_param(tp, &tp->t_termios);
334 		/* Prevent modem control on callout devices and /dev/console. */
335 		if (TTY_CALLOUT(tp, dev) || dev == dev_console)
336 			tp->t_termios.c_cflag |= CLOCAL;
337 
338 		if ((tp->t_termios.c_cflag & CNO_RTSDTR) == 0)
339 			ttydevsw_modem(tp, SER_DTR|SER_RTS, 0);
340 
341 		error = ttydevsw_open(tp);
342 		if (error != 0)
343 			goto done;
344 
345 		ttydisc_open(tp);
346 		error = tty_watermarks(tp);
347 		if (error != 0)
348 			goto done;
349 	}
350 
351 	/* Wait for Carrier Detect. */
352 	if ((oflags & O_NONBLOCK) == 0 &&
353 	    (tp->t_termios.c_cflag & CLOCAL) == 0) {
354 		while ((ttydevsw_modem(tp, 0, 0) & SER_DCD) == 0) {
355 			error = tty_wait(tp, &tp->t_dcdwait);
356 			if (error != 0)
357 				goto done;
358 		}
359 	}
360 
361 	if (dev == dev_console)
362 		tp->t_flags |= TF_OPENED_CONS;
363 	else if (TTY_CALLOUT(tp, dev))
364 		tp->t_flags |= TF_OPENED_OUT;
365 	else
366 		tp->t_flags |= TF_OPENED_IN;
367 	MPASS((tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) == 0 ||
368 	    (tp->t_flags & TF_OPENED_OUT) == 0);
369 
370 done:	tp->t_flags &= ~TF_OPENCLOSE;
371 	cv_broadcast(&tp->t_dcdwait);
372 	ttydev_leave(tp, false);
373 
374 	return (error);
375 }
376 
377 static int
ttydev_close(struct cdev * dev,int fflag,int devtype __unused,struct thread * td)378 ttydev_close(struct cdev *dev, int fflag, int devtype __unused,
379     struct thread *td)
380 {
381 	struct tty *tp = dev->si_drv1;
382 
383 	tty_lock(tp);
384 	if ((tp->t_flags & TF_INDEVCLOSE) != 0) {
385 		tty_unlock(tp);
386 		return (0);
387 	}
388 	tp->t_flags |= TF_INDEVCLOSE;
389 
390 	/*
391 	 * Don't actually close the device if it is being used as the
392 	 * console.
393 	 */
394 	MPASS((tp->t_flags & (TF_OPENED_CONS | TF_OPENED_IN)) == 0 ||
395 	    (tp->t_flags & TF_OPENED_OUT) == 0);
396 	if (dev == dev_console)
397 		tp->t_flags &= ~TF_OPENED_CONS;
398 	else
399 		tp->t_flags &= ~(TF_OPENED_IN|TF_OPENED_OUT);
400 
401 	if (tp->t_flags & TF_OPENED) {
402 		tp->t_flags &= ~TF_INDEVCLOSE;
403 		tty_unlock(tp);
404 		return (0);
405 	}
406 
407 	/* If revoking, flush output now to avoid draining it later. */
408 	if ((fflag & FREVOKE) != 0) {
409 		tty_flush(tp, FWRITE);
410 		knlist_delete(&tp->t_inpoll.si_note, td, 1);
411 		knlist_delete(&tp->t_outpoll.si_note, td, 1);
412 	}
413 
414 	tp->t_flags &= ~TF_EXCLUDE;
415 
416 	/* Properly wake up threads that are stuck - revoke(). */
417 	tp->t_revokecnt++;
418 	tty_wakeup(tp, FREAD|FWRITE);
419 	cv_broadcast(&tp->t_bgwait);
420 	cv_broadcast(&tp->t_dcdwait);
421 
422 	ttydev_leave(tp, true);
423 
424 	return (0);
425 }
426 
427 static __inline int
tty_is_ctty(struct tty * tp,struct proc * p)428 tty_is_ctty(struct tty *tp, struct proc *p)
429 {
430 
431 	tty_assert_locked(tp);
432 
433 	return (p->p_session == tp->t_session && p->p_flag & P_CONTROLT);
434 }
435 
436 int
tty_wait_background(struct tty * tp,struct thread * td,int sig,int proctree_lock_mode)437 tty_wait_background(struct tty *tp, struct thread *td, int sig,
438     int proctree_lock_mode)
439 {
440 	struct proc *p;
441 	struct pgrp *pg;
442 	ksiginfo_t ksi;
443 	int error;
444 
445 	MPASS(sig == SIGTTIN || sig == SIGTTOU);
446 	tty_assert_locked(tp);
447 	MPASS(proctree_lock_mode == LA_UNLOCKED ||
448 	    proctree_lock_mode == LA_SLOCKED ||
449 	    proctree_lock_mode == LA_XLOCKED);
450 
451 	p = td->td_proc;
452 	for (;;) {
453 		pg = p->p_pgrp;
454 		PGRP_LOCK(pg);
455 		PROC_LOCK(p);
456 
457 		/*
458 		 * pg may no longer be our process group.
459 		 * Re-check after locking.
460 		 */
461 		if (p->p_pgrp != pg) {
462 			PROC_UNLOCK(p);
463 			PGRP_UNLOCK(pg);
464 			continue;
465 		}
466 
467 		/*
468 		 * The process should only sleep, when:
469 		 * - This terminal is the controlling terminal
470 		 * - Its process group is not the foreground process
471 		 *   group
472 		 * - The parent process isn't waiting for the child to
473 		 *   exit
474 		 * - the signal to send to the process isn't masked
475 		 */
476 		if (!tty_is_ctty(tp, p) || p->p_pgrp == tp->t_pgrp) {
477 			/* Allow the action to happen. */
478 			PROC_UNLOCK(p);
479 			PGRP_UNLOCK(pg);
480 			return (0);
481 		}
482 
483 		if (SIGISMEMBER(p->p_sigacts->ps_sigignore, sig) ||
484 		    SIGISMEMBER(td->td_sigmask, sig)) {
485 			/* Only allow them in write()/ioctl(). */
486 			PROC_UNLOCK(p);
487 			PGRP_UNLOCK(pg);
488 			return (sig == SIGTTOU ? 0 : EIO);
489 		}
490 
491 		if ((p->p_flag & P_PPWAIT) != 0 ||
492 		    (pg->pg_flags & PGRP_ORPHANED) != 0) {
493 			/* Don't allow the action to happen. */
494 			PROC_UNLOCK(p);
495 			PGRP_UNLOCK(pg);
496 			return (EXTERROR(EIO, "cannot wait in background"));
497 		}
498 		PROC_UNLOCK(p);
499 
500 		/*
501 		 * Send the signal and sleep until we're the new
502 		 * foreground process group.
503 		 */
504 		if (sig != 0) {
505 			ksiginfo_init(&ksi);
506 			ksi.ksi_code = SI_KERNEL;
507 			ksi.ksi_signo = sig;
508 			sig = 0;
509 		}
510 
511 		pgsignal(pg, ksi.ksi_signo, 1, &ksi);
512 		PGRP_UNLOCK(pg);
513 
514 		error = tty_wait_proctree(tp, &tp->t_bgwait, proctree_lock_mode);
515 		if (error != 0)
516 			return (error);
517 	}
518 }
519 
520 static int
ttydev_read(struct cdev * dev,struct uio * uio,int ioflag)521 ttydev_read(struct cdev *dev, struct uio *uio, int ioflag)
522 {
523 	struct tty *tp = dev->si_drv1;
524 	int error;
525 
526 	error = ttydev_enter(tp);
527 	if (error)
528 		goto done;
529 	error = ttydisc_read(tp, uio, ioflag);
530 	tty_unlock(tp);
531 
532 	/*
533 	 * The read() call should not throw an error when the device is
534 	 * being destroyed. Silently convert it to an EOF.
535 	 */
536 done:	if (error == ENXIO)
537 		error = 0;
538 	return (error);
539 }
540 
541 static int
ttydev_write(struct cdev * dev,struct uio * uio,int ioflag)542 ttydev_write(struct cdev *dev, struct uio *uio, int ioflag)
543 {
544 	struct tty *tp = dev->si_drv1;
545 	int defer, error;
546 
547 	error = ttydev_enter(tp);
548 	if (error)
549 		return (error);
550 
551 	if (tp->t_termios.c_lflag & TOSTOP) {
552 		error = tty_wait_background(tp, curthread, SIGTTOU,
553 		    LA_UNLOCKED);
554 		if (error)
555 			goto done;
556 	}
557 
558 	if (ioflag & IO_NDELAY && tp->t_flags & TF_BUSY_OUT) {
559 		/* Allow non-blocking writes to bypass serialization. */
560 		error = ttydisc_write(tp, uio, ioflag);
561 	} else {
562 		/* Serialize write() calls. */
563 		while (tp->t_flags & TF_BUSY_OUT) {
564 			error = tty_wait(tp, &tp->t_outserwait);
565 			if (error)
566 				goto done;
567 		}
568 
569 		tp->t_flags |= TF_BUSY_OUT;
570 		defer = sigdeferstop(SIGDEFERSTOP_ERESTART);
571 		error = ttydisc_write(tp, uio, ioflag);
572 		sigallowstop(defer);
573 		tp->t_flags &= ~TF_BUSY_OUT;
574 		cv_signal(&tp->t_outserwait);
575 	}
576 
577 done:	tty_unlock(tp);
578 	return (error);
579 }
580 
581 static int
tty_ioctl_cnotty(struct tty * tp,struct thread * td)582 tty_ioctl_cnotty(struct tty *tp, struct thread *td)
583 {
584 	struct session *session;
585 	struct vnode *vp;
586 	struct proc *p;
587 	int error;
588 
589 	p = td->td_proc;
590 	error = 0;
591 
592 	sx_xlock(&proctree_lock);
593 	error = ttydev_enter(tp);
594 	if (error != 0)
595 		goto out_unlock2;
596 
597 	/*
598 	 * If the session doesn't have a controlling TTY, or if we weren't
599 	 * invoked on the controlling TTY, we'll return ENOTTY as we've
600 	 * historically done.
601 	 */
602 	session = p->p_session;
603 	if (session->s_ttyp == NULL || session->s_ttyp != tp) {
604 		error = EXTERROR(ENOTTY, "no controlling tty");
605 		goto out_unlock1;
606 	}
607 
608 	if (!SESS_LEADER(p)) {
609 		error = EXTERROR(EPERM, "not a session leader");
610 		goto out_unlock1;
611 	}
612 
613 	PROC_LOCK(p);
614 	SESS_LOCK(session);
615 	vp = session->s_ttyvp;
616 	session->s_ttyp = NULL;
617 	session->s_ttyvp = NULL;
618 	session->s_ttydp = NULL;
619 	SESS_UNLOCK(session);
620 
621 	if (tp->t_session == session) {
622 		tp->t_session = NULL;
623 		tp->t_pgrp = NULL;
624 	}
625 	tp->t_sessioncnt--;
626 	p->p_flag &= ~P_CONTROLT;
627 	PROC_UNLOCK(p);
628 	sx_xunlock(&proctree_lock);
629 
630 	/*
631 	 * If we did have a vnode, release our reference.  Ordinarily
632 	 * we manage these at the devfs layer, but we can't
633 	 * necessarily know that we were invoked on the vnode
634 	 * referenced in the session (i.e. the vnode we hold a
635 	 * reference to).  We explicitly don't check VBAD/VIRF_DOOMED
636 	 * here to avoid a vnode leak -- in circumstances elsewhere
637 	 * where we'd hit a VIRF_DOOMED vnode, release has been
638 	 * deferred until the controlling TTY is either changed or
639 	 * released.
640 	 */
641 	if (vp != NULL)
642 		devfs_ctty_unref(vp);
643 
644 	tty_unlock(tp);
645 	return (error);
646 
647 out_unlock1:
648 	tty_unlock(tp);
649 out_unlock2:
650 	sx_xunlock(&proctree_lock);
651 	return (error);
652 }
653 
654 static int
ttydev_ioctl_sctty(struct tty * tp,caddr_t data,struct thread * td)655 ttydev_ioctl_sctty(struct tty *tp, caddr_t data, struct thread *td)
656 {
657 	struct proc *p;
658 	int error;
659 
660 	p = td->td_proc;
661 	error = 0;
662 
663 	error = ttydev_enter(tp);
664 	if (error != 0)
665 		return (error);
666 
667 	error = tty_wait_background(tp, td, SIGTTOU, LA_XLOCKED);
668 	if (error != 0)
669 		goto out;
670 
671 	if (!SESS_LEADER(p)) {
672 		/* Only the session leader may do this. */
673 		error = EXTERROR(EPERM, "not a session leader");
674 		goto out;
675 	}
676 
677 	if (tp->t_session != NULL && tp->t_session == p->p_session) {
678 		/* This is already our controlling TTY. */
679 		goto out;
680 	}
681 
682 	if (p->p_session->s_ttyp != NULL ||
683 	    (tp->t_session != NULL && tp->t_session->s_ttyvp != NULL &&
684 	    tp->t_session->s_ttyvp->v_type != VBAD)) {
685 		/*
686 		 * There is already a relation between a TTY and
687 		 * a session, or the caller is not the session
688 		 * leader.
689 		 *
690 		 * Allow the TTY to be stolen when the vnode is
691 		 * invalid, but the reference to the TTY is
692 		 * still active.  This allows immediate reuse of
693 		 * TTYs of which the session leader has been
694 		 * killed or the TTY revoked.
695 		 */
696 		error = EXTERROR(EPERM, "session already has CTTY");
697 		goto out;
698 	}
699 
700 	/* Connect the session to the TTY. */
701 	tp->t_session = p->p_session;
702 	tp->t_session->s_ttyp = tp;
703 	tp->t_sessioncnt++;
704 
705 	/* Assign foreground process group. */
706 	tp->t_pgrp = p->p_pgrp;
707 	PROC_LOCK(p);
708 	p->p_flag |= P_CONTROLT;
709 	PROC_UNLOCK(p);
710 out:
711 	tty_unlock(tp);
712 	return (error);
713 }
714 
715 static int
ttydev_ioctl_spgrp(struct tty * tp,caddr_t data,struct thread * td)716 ttydev_ioctl_spgrp(struct tty *tp, caddr_t data, struct thread *td)
717 {
718 	struct pgrp *pg;
719 	int error;
720 
721 	error = ttydev_enter(tp);
722 	if (error != 0)
723 		return (error);
724 
725 	error = tty_wait_background(tp, td, SIGTTOU, LA_SLOCKED);
726 	if (error != 0)
727 		goto out;
728 
729 	pg = pgfind(*(int *)data);
730 	if (pg != NULL)
731 		PGRP_UNLOCK(pg);
732 	if (pg == NULL || pg->pg_session != td->td_proc->p_session) {
733 		error = EXTERROR(EPERM,
734 		    "pgrp %jd belongs to other session %jd",
735 		    pg != NULL ? pg->pg_id : -1,
736 		    td->td_proc->p_session->s_sid);
737 		goto out;
738 	}
739 
740 	/*
741 	 * Determine if this TTY is the controlling TTY.
742 	 */
743 	if (!tty_is_ctty(tp, td->td_proc)) {
744 		error = EXTERROR(ENOTTY, "not a controlling tty");
745 		goto out;
746 	}
747 	tp->t_pgrp = pg;
748 
749 	/* Wake up the background process groups. */
750 	cv_broadcast(&tp->t_bgwait);
751 out:
752 	tty_unlock(tp);
753 	return (error);
754 }
755 
756 int
ttydev_ioctl_proctree(struct tty * tp,u_long cmd,caddr_t data,struct thread * td)757 ttydev_ioctl_proctree(struct tty *tp, u_long cmd, caddr_t data,
758     struct thread *td)
759 {
760 	int error;
761 
762 	switch (cmd) {
763 	case TIOCNOTTY:
764 		error = tty_ioctl_cnotty(tp, td);
765 		break;
766 	case TIOCSCTTY:
767 		sx_xlock(&proctree_lock);
768 		error = ttydev_ioctl_sctty(tp, data, td);
769 		sx_xunlock(&proctree_lock);
770 		break;
771 	case TIOCSPGRP:
772 		sx_slock(&proctree_lock);
773 		error = ttydev_ioctl_spgrp(tp, data, td);
774 		sx_sunlock(&proctree_lock);
775 		break;
776 	default:
777 		__unreachable();
778 	}
779 	return (error);
780 }
781 
782 static int
ttydev_ioctl(struct cdev * dev,u_long cmd,caddr_t data,int fflag,struct thread * td)783 ttydev_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
784     struct thread *td)
785 {
786 	struct tty *tp = dev->si_drv1;
787 	int error;
788 
789 	if (cmd == TIOCNOTTY || cmd == TIOCSCTTY || cmd == TIOCSPGRP)
790 		return (ttydev_ioctl_proctree(tp, cmd, data, td));
791 
792 	error = ttydev_enter(tp);
793 	if (error)
794 		return (error);
795 
796 	switch (cmd) {
797 	case TIOCCBRK:
798 	case TIOCCONS:
799 	case TIOCDRAIN:
800 	case TIOCEXCL:
801 	case TIOCFLUSH:
802 	case TIOCNXCL:
803 	case TIOCSBRK:
804 	case TIOCSETA:
805 	case TIOCSETAF:
806 	case TIOCSETAW:
807 	case TIOCSTART:
808 	case TIOCSTAT:
809 	case TIOCSTI:
810 	case TIOCSTOP:
811 	case TIOCSWINSZ:
812 #if 0
813 	case TIOCSDRAINWAIT:
814 	case TIOCSETD:
815 #endif
816 #ifdef COMPAT_43TTY
817 	case  TIOCLBIC:
818 	case  TIOCLBIS:
819 	case  TIOCLSET:
820 	case  TIOCSETC:
821 	case OTIOCSETD:
822 	case  TIOCSETN:
823 	case  TIOCSETP:
824 	case  TIOCSLTC:
825 #endif /* COMPAT_43TTY */
826 		/*
827 		 * If the ioctl() causes the TTY to be modified, let it
828 		 * wait in the background.
829 		 */
830 		error = tty_wait_background(tp, curthread, SIGTTOU,
831 		    LA_UNLOCKED);
832 		if (error)
833 			goto done;
834 	}
835 
836 	if (cmd == TIOCSETA || cmd == TIOCSETAW || cmd == TIOCSETAF) {
837 		struct termios *old = &tp->t_termios;
838 		struct termios *new = (struct termios *)data;
839 		struct termios *lock = TTY_CALLOUT(tp, dev) ?
840 		    &tp->t_termios_lock_out : &tp->t_termios_lock_in;
841 		int cc;
842 
843 		/*
844 		 * Lock state devices.  Just overwrite the values of the
845 		 * commands that are currently in use.
846 		 */
847 		new->c_iflag = (old->c_iflag & lock->c_iflag) |
848 		    (new->c_iflag & ~lock->c_iflag);
849 		new->c_oflag = (old->c_oflag & lock->c_oflag) |
850 		    (new->c_oflag & ~lock->c_oflag);
851 		new->c_cflag = (old->c_cflag & lock->c_cflag) |
852 		    (new->c_cflag & ~lock->c_cflag);
853 		new->c_lflag = (old->c_lflag & lock->c_lflag) |
854 		    (new->c_lflag & ~lock->c_lflag);
855 		for (cc = 0; cc < NCCS; ++cc)
856 			if (lock->c_cc[cc])
857 				new->c_cc[cc] = old->c_cc[cc];
858 		if (lock->c_ispeed)
859 			new->c_ispeed = old->c_ispeed;
860 		if (lock->c_ospeed)
861 			new->c_ospeed = old->c_ospeed;
862 	}
863 
864 	error = tty_ioctl(tp, cmd, data, fflag, td);
865 done:	tty_unlock(tp);
866 
867 	return (error);
868 }
869 
870 static int
ttydev_poll(struct cdev * dev,int events,struct thread * td)871 ttydev_poll(struct cdev *dev, int events, struct thread *td)
872 {
873 	struct tty *tp = dev->si_drv1;
874 	int error, revents = 0;
875 
876 	error = ttydev_enter(tp);
877 	if (error)
878 		return ((events & (POLLIN|POLLRDNORM)) | POLLHUP);
879 
880 	if (events & (POLLIN|POLLRDNORM)) {
881 		/* See if we can read something. */
882 		if (ttydisc_read_poll(tp) > 0)
883 			revents |= events & (POLLIN|POLLRDNORM);
884 	}
885 
886 	if (tp->t_flags & TF_ZOMBIE) {
887 		/* Hangup flag on zombie state. */
888 		revents |= POLLHUP;
889 	} else if (events & (POLLOUT|POLLWRNORM)) {
890 		/* See if we can write something. */
891 		if (ttydisc_write_poll(tp) > 0)
892 			revents |= events & (POLLOUT|POLLWRNORM);
893 	}
894 
895 	if (revents == 0) {
896 		if (events & (POLLIN|POLLRDNORM))
897 			selrecord(td, &tp->t_inpoll);
898 		if (events & (POLLOUT|POLLWRNORM))
899 			selrecord(td, &tp->t_outpoll);
900 	}
901 
902 	tty_unlock(tp);
903 
904 	return (revents);
905 }
906 
907 static int
ttydev_mmap(struct cdev * dev,vm_ooffset_t offset,vm_paddr_t * paddr,int nprot,vm_memattr_t * memattr)908 ttydev_mmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr,
909     int nprot, vm_memattr_t *memattr)
910 {
911 	struct tty *tp = dev->si_drv1;
912 	int error;
913 
914 	/* Handle mmap() through the driver. */
915 
916 	error = ttydev_enter(tp);
917 	if (error)
918 		return (-1);
919 	error = ttydevsw_mmap(tp, offset, paddr, nprot, memattr);
920 	tty_unlock(tp);
921 
922 	return (error);
923 }
924 
925 /*
926  * kqueue support.
927  */
928 
929 static void
tty_kqops_read_detach(struct knote * kn)930 tty_kqops_read_detach(struct knote *kn)
931 {
932 	struct tty *tp = kn->kn_hook;
933 
934 	knlist_remove(&tp->t_inpoll.si_note, kn, 0);
935 }
936 
937 static int
tty_kqops_read_event(struct knote * kn,long hint __unused)938 tty_kqops_read_event(struct knote *kn, long hint __unused)
939 {
940 	struct tty *tp = kn->kn_hook;
941 
942 	tty_assert_locked(tp);
943 
944 	if (tty_gone(tp) || tp->t_flags & TF_ZOMBIE) {
945 		kn->kn_flags |= EV_EOF;
946 		return (1);
947 	} else {
948 		kn->kn_data = ttydisc_read_poll(tp);
949 		return (kn->kn_data > 0);
950 	}
951 }
952 
953 static void
tty_kqops_write_detach(struct knote * kn)954 tty_kqops_write_detach(struct knote *kn)
955 {
956 	struct tty *tp = kn->kn_hook;
957 
958 	knlist_remove(&tp->t_outpoll.si_note, kn, 0);
959 }
960 
961 static int
tty_kqops_write_event(struct knote * kn,long hint __unused)962 tty_kqops_write_event(struct knote *kn, long hint __unused)
963 {
964 	struct tty *tp = kn->kn_hook;
965 
966 	tty_assert_locked(tp);
967 
968 	if (tty_gone(tp)) {
969 		kn->kn_flags |= EV_EOF;
970 		return (1);
971 	} else {
972 		kn->kn_data = ttydisc_write_poll(tp);
973 		return (kn->kn_data > 0);
974 	}
975 }
976 
977 static const struct filterops tty_kqops_read = {
978 	.f_isfd = 1,
979 	.f_detach = tty_kqops_read_detach,
980 	.f_event = tty_kqops_read_event,
981 	.f_copy = knote_triv_copy,
982 };
983 
984 static const struct filterops tty_kqops_write = {
985 	.f_isfd = 1,
986 	.f_detach = tty_kqops_write_detach,
987 	.f_event = tty_kqops_write_event,
988 	.f_copy = knote_triv_copy,
989 };
990 
991 static int
ttydev_kqfilter(struct cdev * dev,struct knote * kn)992 ttydev_kqfilter(struct cdev *dev, struct knote *kn)
993 {
994 	struct tty *tp = dev->si_drv1;
995 	int error;
996 
997 	error = ttydev_enter(tp);
998 	if (error)
999 		return (error);
1000 
1001 	switch (kn->kn_filter) {
1002 	case EVFILT_READ:
1003 		kn->kn_hook = tp;
1004 		kn->kn_fop = &tty_kqops_read;
1005 		knlist_add(&tp->t_inpoll.si_note, kn, 1);
1006 		break;
1007 	case EVFILT_WRITE:
1008 		kn->kn_hook = tp;
1009 		kn->kn_fop = &tty_kqops_write;
1010 		knlist_add(&tp->t_outpoll.si_note, kn, 1);
1011 		break;
1012 	default:
1013 		error = EINVAL;
1014 		break;
1015 	}
1016 
1017 	tty_unlock(tp);
1018 	return (error);
1019 }
1020 
1021 static struct cdevsw ttydev_cdevsw = {
1022 	.d_version	= D_VERSION,
1023 	.d_open		= ttydev_open,
1024 	.d_close	= ttydev_close,
1025 	.d_read		= ttydev_read,
1026 	.d_write	= ttydev_write,
1027 	.d_ioctl	= ttydev_ioctl,
1028 	.d_kqfilter	= ttydev_kqfilter,
1029 	.d_poll		= ttydev_poll,
1030 	.d_mmap		= ttydev_mmap,
1031 	.d_name		= "ttydev",
1032 	.d_flags	= D_TTY,
1033 };
1034 
1035 /*
1036  * Init/lock-state devices
1037  */
1038 
1039 static int
ttyil_open(struct cdev * dev,int oflags __unused,int devtype __unused,struct thread * td)1040 ttyil_open(struct cdev *dev, int oflags __unused, int devtype __unused,
1041     struct thread *td)
1042 {
1043 	struct tty *tp;
1044 	int error;
1045 
1046 	tp = dev->si_drv1;
1047 	error = 0;
1048 	tty_lock(tp);
1049 	if (tty_gone(tp))
1050 		error = ENODEV;
1051 	tty_unlock(tp);
1052 
1053 	return (error);
1054 }
1055 
1056 static int
ttyil_close(struct cdev * dev __unused,int flag __unused,int mode __unused,struct thread * td __unused)1057 ttyil_close(struct cdev *dev __unused, int flag __unused, int mode __unused,
1058     struct thread *td __unused)
1059 {
1060 
1061 	return (0);
1062 }
1063 
1064 static int
ttyil_rdwr(struct cdev * dev __unused,struct uio * uio __unused,int ioflag __unused)1065 ttyil_rdwr(struct cdev *dev __unused, struct uio *uio __unused,
1066     int ioflag __unused)
1067 {
1068 
1069 	return (ENODEV);
1070 }
1071 
1072 static int
ttyil_ioctl(struct cdev * dev,u_long cmd,caddr_t data,int fflag,struct thread * td)1073 ttyil_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int fflag,
1074     struct thread *td)
1075 {
1076 	struct tty *tp = dev->si_drv1;
1077 	int error;
1078 
1079 	tty_lock(tp);
1080 	if (tty_gone(tp)) {
1081 		error = (EXTERROR(ENODEV, "ttyil_ioctl: device is gone"));
1082 		goto done;
1083 	}
1084 
1085 	error = ttydevsw_cioctl(tp, dev2unit(dev), cmd, data, td);
1086 	if (error != ENOIOCTL)
1087 		goto done;
1088 	error = 0;
1089 
1090 	switch (cmd) {
1091 	case TIOCGETA:
1092 		/* Obtain terminal flags through tcgetattr(). */
1093 		*(struct termios*)data = *(struct termios*)dev->si_drv2;
1094 		break;
1095 	case TIOCSETA:
1096 		/* Set terminal flags through tcsetattr(). */
1097 		error = priv_check(td, PRIV_TTY_SETA);
1098 		if (error)
1099 			break;
1100 		*(struct termios*)dev->si_drv2 = *(struct termios*)data;
1101 		break;
1102 	case TIOCGETD:
1103 		*(int *)data = TTYDISC;
1104 		break;
1105 	case TIOCGWINSZ:
1106 		bzero(data, sizeof(struct winsize));
1107 		break;
1108 	default:
1109 		error = ENOTTY;
1110 	}
1111 
1112 done:	tty_unlock(tp);
1113 	return (error);
1114 }
1115 
1116 static struct cdevsw ttyil_cdevsw = {
1117 	.d_version	= D_VERSION,
1118 	.d_open		= ttyil_open,
1119 	.d_close	= ttyil_close,
1120 	.d_read		= ttyil_rdwr,
1121 	.d_write	= ttyil_rdwr,
1122 	.d_ioctl	= ttyil_ioctl,
1123 	.d_name		= "ttyil",
1124 	.d_flags	= D_TTY,
1125 };
1126 
1127 static void
tty_init_termios(struct tty * tp)1128 tty_init_termios(struct tty *tp)
1129 {
1130 	struct termios *t = &tp->t_termios_init_in;
1131 
1132 	t->c_cflag = TTYDEF_CFLAG;
1133 	t->c_iflag = TTYDEF_IFLAG;
1134 	t->c_lflag = TTYDEF_LFLAG;
1135 	t->c_oflag = TTYDEF_OFLAG;
1136 	t->c_ispeed = TTYDEF_SPEED;
1137 	t->c_ospeed = TTYDEF_SPEED;
1138 	memcpy(&t->c_cc, ttydefchars, sizeof ttydefchars);
1139 
1140 	tp->t_termios_init_out = *t;
1141 }
1142 
1143 void
tty_init_console(struct tty * tp,speed_t s)1144 tty_init_console(struct tty *tp, speed_t s)
1145 {
1146 	struct termios *ti = &tp->t_termios_init_in;
1147 	struct termios *to = &tp->t_termios_init_out;
1148 
1149 	if (s != 0) {
1150 		ti->c_ispeed = ti->c_ospeed = s;
1151 		to->c_ispeed = to->c_ospeed = s;
1152 	}
1153 
1154 	ti->c_cflag |= CLOCAL;
1155 	to->c_cflag |= CLOCAL;
1156 }
1157 
1158 /*
1159  * Standard device routine implementations, mostly meant for
1160  * pseudo-terminal device drivers. When a driver creates a new terminal
1161  * device class, missing routines are patched.
1162  */
1163 
1164 static int
ttydevsw_defopen(struct tty * tp __unused)1165 ttydevsw_defopen(struct tty *tp __unused)
1166 {
1167 
1168 	return (0);
1169 }
1170 
1171 static void
ttydevsw_defclose(struct tty * tp __unused)1172 ttydevsw_defclose(struct tty *tp __unused)
1173 {
1174 
1175 }
1176 
1177 static void
ttydevsw_defoutwakeup(struct tty * tp __unused)1178 ttydevsw_defoutwakeup(struct tty *tp __unused)
1179 {
1180 
1181 	panic("Terminal device has output, while not implemented");
1182 }
1183 
1184 static void
ttydevsw_definwakeup(struct tty * tp __unused)1185 ttydevsw_definwakeup(struct tty *tp __unused)
1186 {
1187 
1188 }
1189 
1190 static int
ttydevsw_defioctl(struct tty * tp __unused,u_long cmd __unused,caddr_t data __unused,struct thread * td __unused)1191 ttydevsw_defioctl(struct tty *tp __unused, u_long cmd __unused,
1192     caddr_t data __unused, struct thread *td __unused)
1193 {
1194 
1195 	return (ENOIOCTL);
1196 }
1197 
1198 static int
ttydevsw_defcioctl(struct tty * tp __unused,int unit __unused,u_long cmd __unused,caddr_t data __unused,struct thread * td __unused)1199 ttydevsw_defcioctl(struct tty *tp __unused, int unit __unused,
1200     u_long cmd __unused, caddr_t data __unused, struct thread *td __unused)
1201 {
1202 
1203 	return (ENOIOCTL);
1204 }
1205 
1206 static int
ttydevsw_defparam(struct tty * tp __unused,struct termios * t)1207 ttydevsw_defparam(struct tty *tp __unused, struct termios *t)
1208 {
1209 
1210 	/*
1211 	 * Allow the baud rate to be adjusted for pseudo-devices, but at
1212 	 * least restrict it to 115200 to prevent excessive buffer
1213 	 * usage.  Also disallow 0, to prevent foot shooting.
1214 	 */
1215 	if (t->c_ispeed < B50)
1216 		t->c_ispeed = B50;
1217 	else if (t->c_ispeed > B115200)
1218 		t->c_ispeed = B115200;
1219 	if (t->c_ospeed < B50)
1220 		t->c_ospeed = B50;
1221 	else if (t->c_ospeed > B115200)
1222 		t->c_ospeed = B115200;
1223 	t->c_cflag |= CREAD;
1224 
1225 	return (0);
1226 }
1227 
1228 static int
ttydevsw_defmodem(struct tty * tp __unused,int sigon __unused,int sigoff __unused)1229 ttydevsw_defmodem(struct tty *tp __unused, int sigon __unused,
1230     int sigoff __unused)
1231 {
1232 
1233 	/* Simulate a carrier to make the TTY layer happy. */
1234 	return (SER_DCD);
1235 }
1236 
1237 static int
ttydevsw_defmmap(struct tty * tp __unused,vm_ooffset_t offset __unused,vm_paddr_t * paddr __unused,int nprot __unused,vm_memattr_t * memattr __unused)1238 ttydevsw_defmmap(struct tty *tp __unused, vm_ooffset_t offset __unused,
1239     vm_paddr_t *paddr __unused, int nprot __unused,
1240     vm_memattr_t *memattr __unused)
1241 {
1242 
1243 	return (-1);
1244 }
1245 
1246 static void
ttydevsw_defpktnotify(struct tty * tp __unused,char event __unused)1247 ttydevsw_defpktnotify(struct tty *tp __unused, char event __unused)
1248 {
1249 
1250 }
1251 
1252 static void
ttydevsw_deffree(void * softc __unused)1253 ttydevsw_deffree(void *softc __unused)
1254 {
1255 
1256 	panic("Terminal device freed without a free-handler");
1257 }
1258 
1259 static bool
ttydevsw_defbusy(struct tty * tp __unused)1260 ttydevsw_defbusy(struct tty *tp __unused)
1261 {
1262 
1263 	return (false);
1264 }
1265 
1266 /*
1267  * TTY allocation and deallocation. TTY devices can be deallocated when
1268  * the driver doesn't use it anymore, when the TTY isn't a session's
1269  * controlling TTY and when the device node isn't opened through devfs.
1270  */
1271 
1272 struct tty *
tty_alloc(struct ttydevsw * tsw,void * sc)1273 tty_alloc(struct ttydevsw *tsw, void *sc)
1274 {
1275 
1276 	return (tty_alloc_mutex(tsw, sc, NULL));
1277 }
1278 
1279 struct tty *
tty_alloc_mutex(struct ttydevsw * tsw,void * sc,struct mtx * mutex)1280 tty_alloc_mutex(struct ttydevsw *tsw, void *sc, struct mtx *mutex)
1281 {
1282 	struct tty *tp;
1283 
1284 	/* Make sure the driver defines all routines. */
1285 #define PATCH_FUNC(x) do {				\
1286 	if (tsw->tsw_ ## x == NULL)			\
1287 		tsw->tsw_ ## x = ttydevsw_def ## x;	\
1288 } while (0)
1289 	PATCH_FUNC(open);
1290 	PATCH_FUNC(close);
1291 	PATCH_FUNC(outwakeup);
1292 	PATCH_FUNC(inwakeup);
1293 	PATCH_FUNC(ioctl);
1294 	PATCH_FUNC(cioctl);
1295 	PATCH_FUNC(param);
1296 	PATCH_FUNC(modem);
1297 	PATCH_FUNC(mmap);
1298 	PATCH_FUNC(pktnotify);
1299 	PATCH_FUNC(free);
1300 	PATCH_FUNC(busy);
1301 #undef PATCH_FUNC
1302 
1303 	tp = malloc(sizeof(struct tty) + TTY_PRBUF_SIZE, M_TTY,
1304 	    M_WAITOK | M_ZERO);
1305 	tp->t_prbufsz = TTY_PRBUF_SIZE;
1306 	tp->t_devsw = tsw;
1307 	tp->t_devswsoftc = sc;
1308 	tp->t_flags = tsw->tsw_flags;
1309 	tp->t_drainwait = tty_drainwait;
1310 
1311 	tty_init_termios(tp);
1312 
1313 	cv_init(&tp->t_inwait, "ttyin");
1314 	cv_init(&tp->t_outwait, "ttyout");
1315 	cv_init(&tp->t_outserwait, "ttyosr");
1316 	cv_init(&tp->t_bgwait, "ttybg");
1317 	cv_init(&tp->t_dcdwait, "ttydcd");
1318 
1319 	/* Allow drivers to use a custom mutex to lock the TTY. */
1320 	if (mutex != NULL) {
1321 		tp->t_mtx = mutex;
1322 	} else {
1323 		tp->t_mtx = &tp->t_mtxobj;
1324 		mtx_init(&tp->t_mtxobj, "ttymtx", NULL, MTX_DEF);
1325 	}
1326 
1327 	knlist_init_mtx(&tp->t_inpoll.si_note, tp->t_mtx);
1328 	knlist_init_mtx(&tp->t_outpoll.si_note, tp->t_mtx);
1329 
1330 	return (tp);
1331 }
1332 
1333 static void
tty_dealloc(void * arg)1334 tty_dealloc(void *arg)
1335 {
1336 	struct tty *tp = arg;
1337 
1338 	/*
1339 	 * ttyydev_leave() usually frees the i/o queues earlier, but it is
1340 	 * not always called between queue allocation and here.  The queues
1341 	 * may be allocated by ioctls on a pty control device without the
1342 	 * corresponding pty slave device ever being open, or after it is
1343 	 * closed.
1344 	 */
1345 	ttyinq_free(&tp->t_inq);
1346 	ttyoutq_free(&tp->t_outq);
1347 	seldrain(&tp->t_inpoll);
1348 	seldrain(&tp->t_outpoll);
1349 	knlist_clear(&tp->t_inpoll.si_note, 0);
1350 	knlist_clear(&tp->t_outpoll.si_note, 0);
1351 	knlist_destroy(&tp->t_inpoll.si_note);
1352 	knlist_destroy(&tp->t_outpoll.si_note);
1353 
1354 	cv_destroy(&tp->t_inwait);
1355 	cv_destroy(&tp->t_outwait);
1356 	cv_destroy(&tp->t_bgwait);
1357 	cv_destroy(&tp->t_dcdwait);
1358 	cv_destroy(&tp->t_outserwait);
1359 
1360 	if (tp->t_mtx == &tp->t_mtxobj)
1361 		mtx_destroy(&tp->t_mtxobj);
1362 	ttydevsw_free(tp);
1363 	free(tp, M_TTY);
1364 }
1365 
1366 static void
tty_rel_free(struct tty * tp,bool inttydevclose)1367 tty_rel_free(struct tty *tp, bool inttydevclose)
1368 {
1369 	struct cdev *dev;
1370 
1371 	tty_assert_locked(tp);
1372 
1373 #define	TF_ACTIVITY	(TF_GONE|TF_OPENED|TF_HOOK|TF_OPENCLOSE)
1374 	if (tp->t_sessioncnt != 0 || (tp->t_flags & TF_ACTIVITY) != TF_GONE) {
1375 		/* TTY is still in use. */
1376 		if (inttydevclose)
1377 			tp->t_flags &= ~TF_INDEVCLOSE;
1378 		tty_unlock(tp);
1379 		return;
1380 	}
1381 
1382 	/* Stop asynchronous I/O. */
1383 	funsetown(&tp->t_sigio);
1384 
1385 	/* TTY can be deallocated. */
1386 	dev = tp->t_dev;
1387 	tp->t_dev = NULL;
1388 	if (inttydevclose)
1389 		tp->t_flags &= ~TF_INDEVCLOSE;
1390 	tty_unlock(tp);
1391 
1392 	if (dev != NULL) {
1393 		sx_xlock(&tty_list_sx);
1394 		TAILQ_REMOVE(&tty_list, tp, t_list);
1395 		tty_list_count--;
1396 		sx_xunlock(&tty_list_sx);
1397 		destroy_dev_sched_cb(dev, tty_dealloc, tp);
1398 	}
1399 }
1400 
1401 void
tty_rel_pgrp(struct tty * tp,struct pgrp * pg)1402 tty_rel_pgrp(struct tty *tp, struct pgrp *pg)
1403 {
1404 
1405 	MPASS(tp->t_sessioncnt > 0);
1406 	tty_assert_locked(tp);
1407 
1408 	if (tp->t_pgrp == pg)
1409 		tp->t_pgrp = NULL;
1410 
1411 	tty_unlock(tp);
1412 }
1413 
1414 void
tty_rel_sess(struct tty * tp,struct session * sess)1415 tty_rel_sess(struct tty *tp, struct session *sess)
1416 {
1417 
1418 	MPASS(tp->t_sessioncnt > 0);
1419 
1420 	/* Current session has left. */
1421 	if (tp->t_session == sess) {
1422 		tp->t_session = NULL;
1423 		MPASS(tp->t_pgrp == NULL);
1424 	}
1425 	tp->t_sessioncnt--;
1426 	tty_rel_free(tp, false);
1427 }
1428 
1429 void
tty_rel_gone(struct tty * tp)1430 tty_rel_gone(struct tty *tp)
1431 {
1432 
1433 	tty_assert_locked(tp);
1434 	MPASS(!tty_gone(tp));
1435 
1436 	/* Simulate carrier removal. */
1437 	ttydisc_modem(tp, 0);
1438 
1439 	/* Wake up all blocked threads. */
1440 	tty_wakeup(tp, FREAD|FWRITE);
1441 	cv_broadcast(&tp->t_bgwait);
1442 	cv_broadcast(&tp->t_dcdwait);
1443 
1444 	tp->t_flags |= TF_GONE;
1445 	tty_rel_free(tp, false);
1446 }
1447 
1448 /*
1449  * Exposing information about current TTY's through sysctl
1450  */
1451 
1452 static void
tty_to_xtty(struct tty * tp,struct xtty * xt)1453 tty_to_xtty(struct tty *tp, struct xtty *xt)
1454 {
1455 
1456 	tty_assert_locked(tp);
1457 
1458 	memset(xt, 0, sizeof(*xt));
1459 	xt->xt_size = sizeof(struct xtty);
1460 	xt->xt_insize = ttyinq_getsize(&tp->t_inq);
1461 	xt->xt_incc = ttyinq_bytescanonicalized(&tp->t_inq);
1462 	xt->xt_inlc = ttyinq_bytesline(&tp->t_inq);
1463 	xt->xt_inlow = tp->t_inlow;
1464 	xt->xt_outsize = ttyoutq_getsize(&tp->t_outq);
1465 	xt->xt_outcc = ttyoutq_bytesused(&tp->t_outq);
1466 	xt->xt_outlow = tp->t_outlow;
1467 	xt->xt_column = tp->t_column;
1468 	xt->xt_pgid = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
1469 	xt->xt_sid = tp->t_session ? tp->t_session->s_sid : 0;
1470 	xt->xt_flags = tp->t_flags;
1471 	xt->xt_dev = tp->t_dev ? dev2udev(tp->t_dev) : (uint32_t)NODEV;
1472 }
1473 
1474 static int
sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)1475 sysctl_kern_ttys(SYSCTL_HANDLER_ARGS)
1476 {
1477 	unsigned long lsize;
1478 	struct thread *td = curthread;
1479 	struct xtty *xtlist, *xt;
1480 	struct tty *tp;
1481 	struct proc *p;
1482 	int error;
1483 	bool cansee;
1484 
1485 	sx_slock(&tty_list_sx);
1486 	lsize = tty_list_count * sizeof(struct xtty);
1487 	if (lsize == 0) {
1488 		sx_sunlock(&tty_list_sx);
1489 		return (0);
1490 	}
1491 
1492 	xtlist = xt = malloc(lsize, M_TTY, M_WAITOK);
1493 
1494 	TAILQ_FOREACH(tp, &tty_list, t_list) {
1495 		tty_lock(tp);
1496 		if (tp->t_session != NULL &&
1497 		    (p = atomic_load_ptr(&tp->t_session->s_leader)) != NULL) {
1498 			PROC_LOCK(p);
1499 			cansee = (p_cansee(td, p) == 0);
1500 			PROC_UNLOCK(p);
1501 		} else {
1502 			cansee = !jailed(td->td_ucred);
1503 		}
1504 		if (cansee) {
1505 			tty_to_xtty(tp, xt);
1506 			xt++;
1507 		}
1508 		tty_unlock(tp);
1509 	}
1510 	sx_sunlock(&tty_list_sx);
1511 
1512 	lsize = (xt - xtlist) * sizeof(struct xtty);
1513 	if (lsize > 0) {
1514 		error = SYSCTL_OUT(req, xtlist, lsize);
1515 	} else {
1516 		error = 0;
1517 	}
1518 	free(xtlist, M_TTY);
1519 	return (error);
1520 }
1521 
1522 SYSCTL_PROC(_kern, OID_AUTO, ttys, CTLTYPE_OPAQUE|CTLFLAG_RD|CTLFLAG_MPSAFE,
1523 	0, 0, sysctl_kern_ttys, "S,xtty", "List of TTYs");
1524 
1525 /*
1526  * Device node creation. Device has been set up, now we can expose it to
1527  * the user.
1528  */
1529 
1530 int
tty_makedevf(struct tty * tp,struct ucred * cred,int flags,const char * fmt,...)1531 tty_makedevf(struct tty *tp, struct ucred *cred, int flags,
1532     const char *fmt, ...)
1533 {
1534 	va_list ap;
1535 	struct make_dev_args args;
1536 	struct cdev *dev, *init, *lock, *cua, *cinit, *clock;
1537 	const char *prefix = "tty";
1538 	char name[SPECNAMELEN - 3]; /* for "tty" and "cua". */
1539 	uid_t uid;
1540 	gid_t gid;
1541 	mode_t mode;
1542 	int error;
1543 
1544 	/* Remove "tty" prefix from devices like PTY's. */
1545 	if (tp->t_flags & TF_NOPREFIX)
1546 		prefix = "";
1547 
1548 	va_start(ap, fmt);
1549 	vsnrprintf(name, sizeof name, 32, fmt, ap);
1550 	va_end(ap);
1551 
1552 	if (cred == NULL) {
1553 		/* System device. */
1554 		uid = UID_ROOT;
1555 		gid = GID_WHEEL;
1556 		mode = S_IRUSR|S_IWUSR;
1557 	} else {
1558 		/* User device. */
1559 		uid = cred->cr_ruid;
1560 		gid = GID_TTY;
1561 		mode = S_IRUSR|S_IWUSR|S_IWGRP;
1562 	}
1563 
1564 	flags = flags & TTYMK_CLONING ? MAKEDEV_REF : 0;
1565 	flags |= MAKEDEV_CHECKNAME;
1566 
1567 	/* Master call-in device. */
1568 	make_dev_args_init(&args);
1569 	args.mda_flags = flags;
1570 	args.mda_devsw = &ttydev_cdevsw;
1571 	args.mda_cr = cred;
1572 	args.mda_uid = uid;
1573 	args.mda_gid = gid;
1574 	args.mda_mode = mode;
1575 	args.mda_si_drv1 = tp;
1576 	error = make_dev_s(&args, &dev, "%s%s", prefix, name);
1577 	if (error != 0)
1578 		return (error);
1579 	tp->t_dev = dev;
1580 
1581 	init = lock = cua = cinit = clock = NULL;
1582 
1583 	/* Slave call-in devices. */
1584 	if (tp->t_flags & TF_INITLOCK) {
1585 		args.mda_devsw = &ttyil_cdevsw;
1586 		args.mda_unit = TTYUNIT_INIT;
1587 		args.mda_si_drv1 = tp;
1588 		args.mda_si_drv2 = &tp->t_termios_init_in;
1589 		error = make_dev_s(&args, &init, "%s%s.init", prefix, name);
1590 		if (error != 0)
1591 			goto fail;
1592 		dev_depends(dev, init);
1593 
1594 		args.mda_unit = TTYUNIT_LOCK;
1595 		args.mda_si_drv2 = &tp->t_termios_lock_in;
1596 		error = make_dev_s(&args, &lock, "%s%s.lock", prefix, name);
1597 		if (error != 0)
1598 			goto fail;
1599 		dev_depends(dev, lock);
1600 	}
1601 
1602 	/* Call-out devices. */
1603 	if (tp->t_flags & TF_CALLOUT) {
1604 		make_dev_args_init(&args);
1605 		args.mda_flags = flags;
1606 		args.mda_devsw = &ttydev_cdevsw;
1607 		args.mda_cr = cred;
1608 		args.mda_uid = UID_UUCP;
1609 		args.mda_gid = GID_DIALER;
1610 		args.mda_mode = 0660;
1611 		args.mda_unit = TTYUNIT_CALLOUT;
1612 		args.mda_si_drv1 = tp;
1613 		error = make_dev_s(&args, &cua, "cua%s", name);
1614 		if (error != 0)
1615 			goto fail;
1616 		dev_depends(dev, cua);
1617 
1618 		/* Slave call-out devices. */
1619 		if (tp->t_flags & TF_INITLOCK) {
1620 			args.mda_devsw = &ttyil_cdevsw;
1621 			args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_INIT;
1622 			args.mda_si_drv2 = &tp->t_termios_init_out;
1623 			error = make_dev_s(&args, &cinit, "cua%s.init", name);
1624 			if (error != 0)
1625 				goto fail;
1626 			dev_depends(dev, cinit);
1627 
1628 			args.mda_unit = TTYUNIT_CALLOUT | TTYUNIT_LOCK;
1629 			args.mda_si_drv2 = &tp->t_termios_lock_out;
1630 			error = make_dev_s(&args, &clock, "cua%s.lock", name);
1631 			if (error != 0)
1632 				goto fail;
1633 			dev_depends(dev, clock);
1634 		}
1635 	}
1636 
1637 	sx_xlock(&tty_list_sx);
1638 	TAILQ_INSERT_TAIL(&tty_list, tp, t_list);
1639 	tty_list_count++;
1640 	sx_xunlock(&tty_list_sx);
1641 
1642 	return (0);
1643 
1644 fail:
1645 	destroy_dev(dev);
1646 	if (init)
1647 		destroy_dev(init);
1648 	if (lock)
1649 		destroy_dev(lock);
1650 	if (cinit)
1651 		destroy_dev(cinit);
1652 	if (clock)
1653 		destroy_dev(clock);
1654 
1655 	return (error);
1656 }
1657 
1658 /*
1659  * Signalling processes.
1660  */
1661 
1662 void
tty_signal_sessleader(struct tty * tp,int sig)1663 tty_signal_sessleader(struct tty *tp, int sig)
1664 {
1665 	struct proc *p;
1666 	struct session *s;
1667 
1668 	tty_assert_locked(tp);
1669 	MPASS(sig >= 1 && sig < NSIG);
1670 
1671 	/* Make signals start output again. */
1672 	tp->t_flags &= ~TF_STOPPED;
1673 	tp->t_termios.c_lflag &= ~FLUSHO;
1674 
1675 	/*
1676 	 * Load s_leader exactly once to avoid race where s_leader is
1677 	 * set to NULL by a concurrent invocation of killjobc() by the
1678 	 * session leader.  Note that we are not holding t_session's
1679 	 * lock for the read.
1680 	 */
1681 	if ((s = tp->t_session) != NULL &&
1682 	    (p = atomic_load_ptr(&s->s_leader)) != NULL) {
1683 		PROC_LOCK(p);
1684 		kern_psignal(p, sig);
1685 		PROC_UNLOCK(p);
1686 	}
1687 }
1688 
1689 void
tty_signal_pgrp(struct tty * tp,int sig)1690 tty_signal_pgrp(struct tty *tp, int sig)
1691 {
1692 	ksiginfo_t ksi;
1693 
1694 	tty_assert_locked(tp);
1695 	MPASS(sig >= 1 && sig < NSIG);
1696 
1697 	/* Make signals start output again. */
1698 	tp->t_flags &= ~TF_STOPPED;
1699 	tp->t_termios.c_lflag &= ~FLUSHO;
1700 
1701 	if (sig == SIGINFO && !(tp->t_termios.c_lflag & NOKERNINFO))
1702 		tty_info(tp);
1703 	if (tp->t_pgrp != NULL) {
1704 		ksiginfo_init(&ksi);
1705 		ksi.ksi_signo = sig;
1706 		ksi.ksi_code = SI_KERNEL;
1707 		PGRP_LOCK(tp->t_pgrp);
1708 		pgsignal(tp->t_pgrp, sig, 1, &ksi);
1709 		PGRP_UNLOCK(tp->t_pgrp);
1710 	}
1711 }
1712 
1713 void
tty_wakeup(struct tty * tp,int flags)1714 tty_wakeup(struct tty *tp, int flags)
1715 {
1716 
1717 	if (tp->t_flags & TF_ASYNC && tp->t_sigio != NULL)
1718 		pgsigio(&tp->t_sigio, SIGIO, (tp->t_session != NULL));
1719 
1720 	if (flags & FWRITE) {
1721 		cv_broadcast(&tp->t_outwait);
1722 		selwakeup(&tp->t_outpoll);
1723 		KNOTE_LOCKED(&tp->t_outpoll.si_note, 0);
1724 	}
1725 	if (flags & FREAD) {
1726 		cv_broadcast(&tp->t_inwait);
1727 		selwakeup(&tp->t_inpoll);
1728 		KNOTE_LOCKED(&tp->t_inpoll.si_note, 0);
1729 	}
1730 }
1731 
1732 int
tty_wait(struct tty * tp,struct cv * cv)1733 tty_wait(struct tty *tp, struct cv *cv)
1734 {
1735 	int error;
1736 	int revokecnt = tp->t_revokecnt;
1737 
1738 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1739 	MPASS(!tty_gone(tp));
1740 
1741 	error = cv_wait_sig(cv, tp->t_mtx);
1742 
1743 	/* Bail out when the device slipped away. */
1744 	if (tty_gone(tp))
1745 		return (EXTERROR(ENXIO, "tty_wait: device is gone"));
1746 
1747 	/* Restart the system call when we may have been revoked. */
1748 	if (tp->t_revokecnt != revokecnt)
1749 		return (ERESTART);
1750 
1751 	return (error);
1752 }
1753 
1754 static int
tty_wait_proctree(struct tty * tp,struct cv * cv,int proctree_lock_mode)1755 tty_wait_proctree(struct tty *tp, struct cv *cv, int proctree_lock_mode)
1756 {
1757 	int error;
1758 	int revokecnt = tp->t_revokecnt;
1759 
1760 	tty_lock_assert(tp, MA_OWNED | MA_NOTRECURSED);
1761 	MPASS(!tty_gone(tp));
1762 	MPASS(proctree_lock_mode == LA_UNLOCKED ||
1763 	    proctree_lock_mode == LA_SLOCKED ||
1764 	    proctree_lock_mode == LA_XLOCKED);
1765 
1766 	if (proctree_lock_mode != LA_UNLOCKED)
1767 		sx_unlock(&proctree_lock);
1768 
1769 	error = cv_wait_sig_unlock(cv, tp->t_mtx);
1770 	switch (proctree_lock_mode) {
1771 	case LA_SLOCKED:
1772 		sx_slock(&proctree_lock);
1773 		break;
1774 	case LA_XLOCKED:
1775 		sx_xlock(&proctree_lock);
1776 		break;
1777 	}
1778 	tty_lock(tp);
1779 
1780 	/* Bail out when the device slipped away. */
1781 	if (tty_gone(tp))
1782 		return (EXTERROR(ENXIO, "tty_wait_proctree: device is gone"));
1783 
1784 	/* Restart the system call when we may have been revoked. */
1785 	if (tp->t_revokecnt != revokecnt)
1786 		return (ERESTART);
1787 
1788 	return (error);
1789 }
1790 
1791 int
tty_timedwait(struct tty * tp,struct cv * cv,int hz)1792 tty_timedwait(struct tty *tp, struct cv *cv, int hz)
1793 {
1794 	int error;
1795 	int revokecnt = tp->t_revokecnt;
1796 
1797 	tty_lock_assert(tp, MA_OWNED|MA_NOTRECURSED);
1798 	MPASS(!tty_gone(tp));
1799 
1800 	error = cv_timedwait_sig(cv, tp->t_mtx, hz);
1801 
1802 	/* Bail out when the device slipped away. */
1803 	if (tty_gone(tp))
1804 		return (EXTERROR(ENXIO, "tty_timedwait: device is gone"));
1805 
1806 	/* Restart the system call when we may have been revoked. */
1807 	if (tp->t_revokecnt != revokecnt)
1808 		return (ERESTART);
1809 
1810 	return (error);
1811 }
1812 
1813 void
tty_flush(struct tty * tp,int flags)1814 tty_flush(struct tty *tp, int flags)
1815 {
1816 
1817 	if (flags & FWRITE) {
1818 		tp->t_flags &= ~TF_HIWAT_OUT;
1819 		ttyoutq_flush(&tp->t_outq);
1820 		tty_wakeup(tp, FWRITE);
1821 		if (!tty_gone(tp)) {
1822 			ttydevsw_outwakeup(tp);
1823 			ttydevsw_pktnotify(tp, TIOCPKT_FLUSHWRITE);
1824 		}
1825 	}
1826 	if (flags & FREAD) {
1827 		tty_hiwat_in_unblock(tp);
1828 		ttyinq_flush(&tp->t_inq);
1829 		tty_wakeup(tp, FREAD);
1830 		if (!tty_gone(tp)) {
1831 			ttydevsw_inwakeup(tp);
1832 			ttydevsw_pktnotify(tp, TIOCPKT_FLUSHREAD);
1833 		}
1834 	}
1835 }
1836 
1837 void
tty_set_winsize(struct tty * tp,const struct winsize * wsz)1838 tty_set_winsize(struct tty *tp, const struct winsize *wsz)
1839 {
1840 
1841 	if (memcmp(&tp->t_winsize, wsz, sizeof(*wsz)) == 0)
1842 		return;
1843 	tp->t_winsize = *wsz;
1844 	tty_signal_pgrp(tp, SIGWINCH);
1845 }
1846 
1847 static int
tty_sti_check(struct tty * tp,int fflag,struct thread * td)1848 tty_sti_check(struct tty *tp, int fflag, struct thread *td)
1849 {
1850 	/* Check for global disable. */
1851 	if (!tty_tiocsti)
1852 		return (EXTERROR(EPERM, "security.bsd.allow_tiocsti"));
1853 
1854 	/* Root can bypass all of our constraints. */
1855 	if (priv_check(td, PRIV_TTY_STI) == 0)
1856 		return (0);
1857 
1858 	/* Unprivileged users must have it opened for read. */
1859 	if ((fflag & FREAD) == 0)
1860 		return (EXTERROR(EPERM, "opened read-only"));
1861 
1862 	/* It must also be their controlling tty. */
1863 	if (!tty_is_ctty(tp, td->td_proc))
1864 		return (EXTERROR(EACCES, "not a controlling tty"));
1865 
1866 	return (0);
1867 }
1868 
1869 static int
tty_generic_ioctl(struct tty * tp,u_long cmd,void * data,int fflag,struct thread * td)1870 tty_generic_ioctl(struct tty *tp, u_long cmd, void *data, int fflag,
1871     struct thread *td)
1872 {
1873 	int error;
1874 
1875 	switch (cmd) {
1876 	/*
1877 	 * Modem commands.
1878 	 * The SER_* and TIOCM_* flags are the same, but one bit
1879 	 * shifted. I don't know why.
1880 	 */
1881 	case TIOCSDTR:
1882 		ttydevsw_modem(tp, SER_DTR, 0);
1883 		return (0);
1884 	case TIOCCDTR:
1885 		ttydevsw_modem(tp, 0, SER_DTR);
1886 		return (0);
1887 	case TIOCMSET: {
1888 		int bits = *(int *)data;
1889 		ttydevsw_modem(tp,
1890 		    (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1,
1891 		    ((~bits) & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1892 		return (0);
1893 	}
1894 	case TIOCMBIS: {
1895 		int bits = *(int *)data;
1896 		ttydevsw_modem(tp, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1, 0);
1897 		return (0);
1898 	}
1899 	case TIOCMBIC: {
1900 		int bits = *(int *)data;
1901 		ttydevsw_modem(tp, 0, (bits & (TIOCM_DTR | TIOCM_RTS)) >> 1);
1902 		return (0);
1903 	}
1904 	case TIOCMGET:
1905 		*(int *)data = TIOCM_LE + (ttydevsw_modem(tp, 0, 0) << 1);
1906 		return (0);
1907 
1908 	case FIOASYNC:
1909 		if (*(int *)data)
1910 			tp->t_flags |= TF_ASYNC;
1911 		else
1912 			tp->t_flags &= ~TF_ASYNC;
1913 		return (0);
1914 	case FIONBIO:
1915 		/* This device supports non-blocking operation. */
1916 		return (0);
1917 	case FIONREAD:
1918 		*(int *)data = ttydisc_bytesavail(tp);
1919 		return (0);
1920 	case FIONWRITE:
1921 	case TIOCOUTQ:
1922 		*(int *)data = ttyoutq_bytesused(&tp->t_outq);
1923 		return (0);
1924 	case FIOSETOWN:
1925 		if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1926 			/* Not allowed to set ownership. */
1927 			return (ENOTTY);
1928 
1929 		/* Temporarily unlock the TTY to set ownership. */
1930 		tty_unlock(tp);
1931 		error = fsetown(*(int *)data, &tp->t_sigio);
1932 		tty_lock(tp);
1933 		return (error);
1934 	case FIOGETOWN:
1935 		if (tp->t_session != NULL && !tty_is_ctty(tp, td->td_proc))
1936 			/* Not allowed to set ownership. */
1937 			return (ENOTTY);
1938 
1939 		/* Get ownership. */
1940 		*(int *)data = fgetown(&tp->t_sigio);
1941 		return (0);
1942 	case TIOCGETA:
1943 		/* Obtain terminal flags through tcgetattr(). */
1944 		*(struct termios*)data = tp->t_termios;
1945 		return (0);
1946 	case TIOCSETA:
1947 	case TIOCSETAW:
1948 	case TIOCSETAF: {
1949 		struct termios *t = data;
1950 		bool canonicalize = false;
1951 
1952 		/*
1953 		 * Who makes up these funny rules? According to POSIX,
1954 		 * input baud rate is set equal to the output baud rate
1955 		 * when zero.
1956 		 */
1957 		if (t->c_ispeed == 0)
1958 			t->c_ispeed = t->c_ospeed;
1959 
1960 		/* Discard any unsupported bits. */
1961 		t->c_iflag &= TTYSUP_IFLAG;
1962 		t->c_oflag &= TTYSUP_OFLAG;
1963 		t->c_lflag &= TTYSUP_LFLAG;
1964 		t->c_cflag &= TTYSUP_CFLAG;
1965 
1966 		/* Set terminal flags through tcsetattr(). */
1967 		if (cmd == TIOCSETAW || cmd == TIOCSETAF) {
1968 			error = tty_drain(tp, 0);
1969 			if (error)
1970 				return (error);
1971 			if (cmd == TIOCSETAF)
1972 				tty_flush(tp, FREAD);
1973 		}
1974 
1975 		/*
1976 		 * Only call param() when the flags really change.
1977 		 */
1978 		if ((t->c_cflag & CIGNORE) == 0 &&
1979 		    (tp->t_termios.c_cflag != t->c_cflag ||
1980 		    ((tp->t_termios.c_iflag ^ t->c_iflag) &
1981 		    (IXON|IXOFF|IXANY)) ||
1982 		    tp->t_termios.c_ispeed != t->c_ispeed ||
1983 		    tp->t_termios.c_ospeed != t->c_ospeed)) {
1984 			error = ttydevsw_param(tp, t);
1985 			if (error)
1986 				return (error);
1987 
1988 			/* XXX: CLOCAL? */
1989 
1990 			tp->t_termios.c_cflag = t->c_cflag & ~CIGNORE;
1991 			tp->t_termios.c_ispeed = t->c_ispeed;
1992 			tp->t_termios.c_ospeed = t->c_ospeed;
1993 
1994 			/* Baud rate has changed - update watermarks. */
1995 			error = tty_watermarks(tp);
1996 			if (error)
1997 				return (error);
1998 		}
1999 
2000 		/*
2001 		 * We'll canonicalize any partial input if we're transitioning
2002 		 * ICANON one way or the other.  If we're going from -ICANON ->
2003 		 * ICANON, then in the worst case scenario we're in the middle
2004 		 * of a line but both ttydisc_read() and FIONREAD will search
2005 		 * for one of our line terminals.
2006 		 */
2007 		if ((t->c_lflag & ICANON) != (tp->t_termios.c_lflag & ICANON))
2008 			canonicalize = true;
2009 		else if (tp->t_termios.c_cc[VEOF] != t->c_cc[VEOF] ||
2010 		    tp->t_termios.c_cc[VEOL] != t->c_cc[VEOL])
2011 			canonicalize = true;
2012 
2013 		/* Copy new non-device driver parameters. */
2014 		tp->t_termios.c_iflag = t->c_iflag;
2015 		tp->t_termios.c_oflag = t->c_oflag;
2016 		tp->t_termios.c_lflag = t->c_lflag;
2017 		memcpy(&tp->t_termios.c_cc, t->c_cc, sizeof t->c_cc);
2018 
2019 		ttydisc_optimize(tp);
2020 
2021 		if (canonicalize)
2022 			ttydisc_canonicalize(tp);
2023 		if ((t->c_lflag & ICANON) == 0) {
2024 			/*
2025 			 * When in non-canonical mode, wake up all
2026 			 * readers. Any partial input has already been
2027 			 * canonicalized above if we were in canonical mode.
2028 			 * VMIN and VTIME could also be adjusted.
2029 			 */
2030 			tty_wakeup(tp, FREAD);
2031 		}
2032 
2033 		/*
2034 		 * For packet mode: notify the PTY consumer that VSTOP
2035 		 * and VSTART may have been changed.
2036 		 */
2037 		if (tp->t_termios.c_iflag & IXON &&
2038 		    tp->t_termios.c_cc[VSTOP] == CTRL('S') &&
2039 		    tp->t_termios.c_cc[VSTART] == CTRL('Q'))
2040 			ttydevsw_pktnotify(tp, TIOCPKT_DOSTOP);
2041 		else
2042 			ttydevsw_pktnotify(tp, TIOCPKT_NOSTOP);
2043 		return (0);
2044 	}
2045 	case TIOCGETD:
2046 		/* For compatibility - we only support TTYDISC. */
2047 		*(int *)data = TTYDISC;
2048 		return (0);
2049 	case TIOCGPGRP:
2050 		if (!tty_is_ctty(tp, td->td_proc))
2051 			return (EXTERROR(ENOTTY, "not a controlling tty"));
2052 
2053 		if (tp->t_pgrp != NULL)
2054 			*(int *)data = tp->t_pgrp->pg_id;
2055 		else
2056 			*(int *)data = NO_PID;
2057 		return (0);
2058 	case TIOCGSID:
2059 		if (!tty_is_ctty(tp, td->td_proc))
2060 			return (EXTERROR(ENOTTY, "not a controlling tty"));
2061 
2062 		MPASS(tp->t_session);
2063 		*(int *)data = tp->t_session->s_sid;
2064 		return (0);
2065 	case TIOCNOTTY:
2066 		panic("TIOCNOTTY");
2067 	case TIOCSCTTY:
2068 		panic("TIOCSCTTY");
2069 	case TIOCSPGRP:
2070 		panic("TIOCSPGRP");
2071 	case TIOCFLUSH: {
2072 		int flags = *(int *)data;
2073 
2074 		if (flags == 0)
2075 			flags = (FREAD|FWRITE);
2076 		else
2077 			flags &= (FREAD|FWRITE);
2078 		tty_flush(tp, flags);
2079 		return (0);
2080 	}
2081 	case TIOCDRAIN:
2082 		/* Drain TTY output. */
2083 		return tty_drain(tp, 0);
2084 	case TIOCGDRAINWAIT:
2085 		*(int *)data = tp->t_drainwait;
2086 		return (0);
2087 	case TIOCSDRAINWAIT:
2088 		error = priv_check(td, PRIV_TTY_DRAINWAIT);
2089 		if (error == 0)
2090 			tp->t_drainwait = *(int *)data;
2091 		return (error);
2092 	case TIOCCONS:
2093 		/* Set terminal as console TTY. */
2094 		if (*(int *)data) {
2095 			error = priv_check(td, PRIV_TTY_CONSOLE);
2096 			if (error)
2097 				return (error);
2098 			error = constty_set(tp);
2099 		} else {
2100 			error = constty_clear(tp);
2101 		}
2102 		return (error);
2103 	case TIOCGWINSZ:
2104 		/* Obtain window size. */
2105 		*(struct winsize*)data = tp->t_winsize;
2106 		return (0);
2107 	case TIOCSWINSZ:
2108 		/* Set window size. */
2109 		tty_set_winsize(tp, data);
2110 		return (0);
2111 	case TIOCEXCL:
2112 		tp->t_flags |= TF_EXCLUDE;
2113 		return (0);
2114 	case TIOCNXCL:
2115 		tp->t_flags &= ~TF_EXCLUDE;
2116 		return (0);
2117 	case TIOCSTOP:
2118 		tp->t_flags |= TF_STOPPED;
2119 		ttydevsw_pktnotify(tp, TIOCPKT_STOP);
2120 		return (0);
2121 	case TIOCSTART:
2122 		tp->t_flags &= ~TF_STOPPED;
2123 		tp->t_termios.c_lflag &= ~FLUSHO;
2124 		ttydevsw_outwakeup(tp);
2125 		ttydevsw_pktnotify(tp, TIOCPKT_START);
2126 		return (0);
2127 	case TIOCSTAT:
2128 		tty_info(tp);
2129 		return (0);
2130 	case TIOCSTI:
2131 		error = tty_sti_check(tp, fflag, td);
2132 		if (error != 0)
2133 			return (error);
2134 		ttydisc_rint(tp, *(char *)data, 0);
2135 		ttydisc_rint_done(tp);
2136 		return (0);
2137 	}
2138 
2139 #ifdef COMPAT_43TTY
2140 	return tty_ioctl_compat(tp, cmd, data, fflag, td);
2141 #else /* !COMPAT_43TTY */
2142 	return (ENOIOCTL);
2143 #endif /* COMPAT_43TTY */
2144 }
2145 
2146 int
tty_ioctl(struct tty * tp,u_long cmd,void * data,int fflag,struct thread * td)2147 tty_ioctl(struct tty *tp, u_long cmd, void *data, int fflag, struct thread *td)
2148 {
2149 	int error;
2150 
2151 	tty_assert_locked(tp);
2152 
2153 	if (tty_gone(tp))
2154 		return (EXTERROR(ENXIO, "tty_ioctl: device is gone"));
2155 
2156 	error = ttydevsw_ioctl(tp, cmd, data, td);
2157 	if (error == ENOIOCTL)
2158 		error = tty_generic_ioctl(tp, cmd, data, fflag, td);
2159 
2160 	return (error);
2161 }
2162 
2163 dev_t
tty_udev(struct tty * tp)2164 tty_udev(struct tty *tp)
2165 {
2166 
2167 	if (tp->t_dev)
2168 		return (dev2udev(tp->t_dev));
2169 	else
2170 		return (NODEV);
2171 }
2172 
2173 int
tty_checkoutq(struct tty * tp)2174 tty_checkoutq(struct tty *tp)
2175 {
2176 
2177 	/* 256 bytes should be enough to print a log message. */
2178 	return (ttyoutq_bytesleft(&tp->t_outq) >= 256);
2179 }
2180 
2181 void
tty_hiwat_in_block(struct tty * tp)2182 tty_hiwat_in_block(struct tty *tp)
2183 {
2184 
2185 	if ((tp->t_flags & TF_HIWAT_IN) == 0 &&
2186 	    tp->t_termios.c_iflag & IXOFF &&
2187 	    tp->t_termios.c_cc[VSTOP] != _POSIX_VDISABLE) {
2188 		/*
2189 		 * Input flow control. Only enter the high watermark when we
2190 		 * can successfully store the VSTOP character.
2191 		 */
2192 		if (ttyoutq_write_nofrag(&tp->t_outq,
2193 		    &tp->t_termios.c_cc[VSTOP], 1) == 0)
2194 			tp->t_flags |= TF_HIWAT_IN;
2195 	} else {
2196 		/* No input flow control. */
2197 		tp->t_flags |= TF_HIWAT_IN;
2198 	}
2199 }
2200 
2201 void
tty_hiwat_in_unblock(struct tty * tp)2202 tty_hiwat_in_unblock(struct tty *tp)
2203 {
2204 
2205 	if (tp->t_flags & TF_HIWAT_IN &&
2206 	    tp->t_termios.c_iflag & IXOFF &&
2207 	    tp->t_termios.c_cc[VSTART] != _POSIX_VDISABLE) {
2208 		/*
2209 		 * Input flow control. Only leave the high watermark when we
2210 		 * can successfully store the VSTART character.
2211 		 */
2212 		if (ttyoutq_write_nofrag(&tp->t_outq,
2213 		    &tp->t_termios.c_cc[VSTART], 1) == 0)
2214 			tp->t_flags &= ~TF_HIWAT_IN;
2215 	} else {
2216 		/* No input flow control. */
2217 		tp->t_flags &= ~TF_HIWAT_IN;
2218 	}
2219 
2220 	if (!tty_gone(tp))
2221 		ttydevsw_inwakeup(tp);
2222 }
2223 
2224 /*
2225  * TTY hooks interface.
2226  */
2227 
2228 static int
ttyhook_defrint(struct tty * tp,char c,int flags)2229 ttyhook_defrint(struct tty *tp, char c, int flags)
2230 {
2231 
2232 	if (ttyhook_rint_bypass(tp, &c, 1) != 1)
2233 		return (-1);
2234 
2235 	return (0);
2236 }
2237 
2238 int
ttyhook_register(struct tty ** rtp,struct proc * p,int fd,struct ttyhook * th,void * softc)2239 ttyhook_register(struct tty **rtp, struct proc *p, int fd, struct ttyhook *th,
2240     void *softc)
2241 {
2242 	struct tty *tp;
2243 	struct file *fp;
2244 	struct cdev *dev;
2245 	struct cdevsw *cdp;
2246 	struct filedesc *fdp;
2247 	cap_rights_t rights;
2248 	int error, ref;
2249 
2250 	/* Validate the file descriptor. */
2251 	/*
2252 	 * XXX this code inspects a file descriptor from a different process,
2253 	 * but there is no dedicated routine to do it in fd code, making the
2254 	 * ordeal highly questionable.
2255 	 */
2256 	fdp = p->p_fd;
2257 	FILEDESC_SLOCK(fdp);
2258 	error = fget_cap_noref(fdp, fd, cap_rights_init_one(&rights, CAP_TTYHOOK),
2259 	    &fp, NULL);
2260 	if (error == 0 && !fhold(fp))
2261 		error = EBADF;
2262 	FILEDESC_SUNLOCK(fdp);
2263 	if (error != 0)
2264 		return (error);
2265 	if (fp->f_ops == &badfileops) {
2266 		error = EBADF;
2267 		goto done1;
2268 	}
2269 
2270 	/*
2271 	 * Make sure the vnode is bound to a character device.
2272 	 * Unlocked check for the vnode type is ok there, because we
2273 	 * only shall prevent calling devvn_refthread on the file that
2274 	 * never has been opened over a character device.
2275 	 */
2276 	if (fp->f_type != DTYPE_VNODE || fp->f_vnode->v_type != VCHR) {
2277 		error = EINVAL;
2278 		goto done1;
2279 	}
2280 
2281 	/* Make sure it is a TTY. */
2282 	cdp = devvn_refthread(fp->f_vnode, &dev, &ref);
2283 	if (cdp == NULL) {
2284 		error = ENXIO;
2285 		goto done1;
2286 	}
2287 	if (dev != fp->f_data) {
2288 		error = ENXIO;
2289 		goto done2;
2290 	}
2291 	if (cdp != &ttydev_cdevsw) {
2292 		error = ENOTTY;
2293 		goto done2;
2294 	}
2295 	tp = dev->si_drv1;
2296 
2297 	/* Try to attach the hook to the TTY. */
2298 	error = EBUSY;
2299 	tty_lock(tp);
2300 	MPASS((tp->t_hook == NULL) == ((tp->t_flags & TF_HOOK) == 0));
2301 	if (tp->t_flags & TF_HOOK)
2302 		goto done3;
2303 
2304 	tp->t_flags |= TF_HOOK;
2305 	tp->t_hook = th;
2306 	tp->t_hooksoftc = softc;
2307 	*rtp = tp;
2308 	error = 0;
2309 
2310 	/* Maybe we can switch into bypass mode now. */
2311 	ttydisc_optimize(tp);
2312 
2313 	/* Silently convert rint() calls to rint_bypass() when possible. */
2314 	if (!ttyhook_hashook(tp, rint) && ttyhook_hashook(tp, rint_bypass))
2315 		th->th_rint = ttyhook_defrint;
2316 
2317 done3:	tty_unlock(tp);
2318 done2:	dev_relthread(dev, ref);
2319 done1:	fdrop(fp, curthread);
2320 	return (error);
2321 }
2322 
2323 void
ttyhook_unregister(struct tty * tp)2324 ttyhook_unregister(struct tty *tp)
2325 {
2326 
2327 	tty_assert_locked(tp);
2328 	MPASS(tp->t_flags & TF_HOOK);
2329 
2330 	/* Disconnect the hook. */
2331 	tp->t_flags &= ~TF_HOOK;
2332 	tp->t_hook = NULL;
2333 
2334 	/* Maybe we need to leave bypass mode. */
2335 	ttydisc_optimize(tp);
2336 
2337 	/* Maybe deallocate the TTY as well. */
2338 	tty_rel_free(tp, false);
2339 }
2340 
2341 /*
2342  * /dev/console handling.
2343  */
2344 
2345 static int
ttyconsdev_open(struct cdev * dev,int oflags,int devtype,struct thread * td)2346 ttyconsdev_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
2347 {
2348 	struct tty *tp;
2349 
2350 	/* System has no console device. */
2351 	if (dev_console_filename == NULL)
2352 		return (EXTERROR(ENXIO, "system has no console device"));
2353 
2354 	/* Look up corresponding TTY by device name. */
2355 	sx_slock(&tty_list_sx);
2356 	TAILQ_FOREACH(tp, &tty_list, t_list) {
2357 		if (strcmp(dev_console_filename, tty_devname(tp)) == 0) {
2358 			dev_console->si_drv1 = tp;
2359 			break;
2360 		}
2361 	}
2362 	sx_sunlock(&tty_list_sx);
2363 
2364 	/* System console has no TTY associated. */
2365 	if (dev_console->si_drv1 == NULL)
2366 		return (EXTERROR(ENXIO, "system console has no TTY attached"));
2367 
2368 	return (ttydev_open(dev, oflags, devtype, td));
2369 }
2370 
2371 static int
ttyconsdev_write(struct cdev * dev,struct uio * uio,int ioflag)2372 ttyconsdev_write(struct cdev *dev, struct uio *uio, int ioflag)
2373 {
2374 
2375 	log_console(uio);
2376 
2377 	return (ttydev_write(dev, uio, ioflag));
2378 }
2379 
2380 /*
2381  * /dev/console is a little different than normal TTY's.  When opened,
2382  * it determines which TTY to use.  When data gets written to it, it
2383  * will be logged in the kernel message buffer.
2384  */
2385 static struct cdevsw ttyconsdev_cdevsw = {
2386 	.d_version	= D_VERSION,
2387 	.d_open		= ttyconsdev_open,
2388 	.d_close	= ttydev_close,
2389 	.d_read		= ttydev_read,
2390 	.d_write	= ttyconsdev_write,
2391 	.d_ioctl	= ttydev_ioctl,
2392 	.d_kqfilter	= ttydev_kqfilter,
2393 	.d_poll		= ttydev_poll,
2394 	.d_mmap		= ttydev_mmap,
2395 	.d_name		= "ttyconsdev",
2396 	.d_flags	= D_TTY,
2397 };
2398 
2399 static void
ttyconsdev_init(void * unused __unused)2400 ttyconsdev_init(void *unused __unused)
2401 {
2402 
2403 	dev_console = make_dev_credf(MAKEDEV_ETERNAL, &ttyconsdev_cdevsw, 0,
2404 	    NULL, UID_ROOT, GID_WHEEL, 0600, "console");
2405 }
2406 
2407 SYSINIT(tty, SI_SUB_DRIVERS, SI_ORDER_FIRST, ttyconsdev_init, NULL);
2408 
2409 void
ttyconsdev_select(const char * name)2410 ttyconsdev_select(const char *name)
2411 {
2412 
2413 	dev_console_filename = name;
2414 }
2415 
2416 /*
2417  * Debugging routines.
2418  */
2419 
2420 #include "opt_ddb.h"
2421 #ifdef DDB
2422 #include <ddb/ddb.h>
2423 #include <ddb/db_sym.h>
2424 
2425 static const struct {
2426 	int flag;
2427 	char val;
2428 } ttystates[] = {
2429 #if 0
2430 	{ TF_NOPREFIX,		'N' },
2431 #endif
2432 	{ TF_INITLOCK,		'I' },
2433 	{ TF_CALLOUT,		'C' },
2434 
2435 	/* Keep these together -> 'Oi' and 'Oo'. */
2436 	{ TF_OPENED,		'O' },
2437 	{ TF_OPENED_IN,		'i' },
2438 	{ TF_OPENED_OUT,	'o' },
2439 	{ TF_OPENED_CONS,	'c' },
2440 
2441 	{ TF_GONE,		'G' },
2442 	{ TF_OPENCLOSE,		'B' },
2443 	{ TF_ASYNC,		'Y' },
2444 	{ TF_LITERAL,		'L' },
2445 
2446 	/* Keep these together -> 'Hi' and 'Ho'. */
2447 	{ TF_HIWAT,		'H' },
2448 	{ TF_HIWAT_IN,		'i' },
2449 	{ TF_HIWAT_OUT,		'o' },
2450 
2451 	{ TF_STOPPED,		'S' },
2452 	{ TF_EXCLUDE,		'X' },
2453 	{ TF_BYPASS,		'l' },
2454 	{ TF_ZOMBIE,		'Z' },
2455 	{ TF_HOOK,		's' },
2456 
2457 	/* Keep these together -> 'bi' and 'bo'. */
2458 	{ TF_BUSY,		'b' },
2459 	{ TF_BUSY_IN,		'i' },
2460 	{ TF_BUSY_OUT,		'o' },
2461 
2462 	{ 0,			'\0'},
2463 };
2464 
2465 #define	TTY_FLAG_BITS \
2466 	"\20\1NOPREFIX\2INITLOCK\3CALLOUT\4OPENED_IN" \
2467 	"\5OPENED_OUT\6OPENED_CONS\7GONE\10OPENCLOSE" \
2468 	"\11ASYNC\12LITERAL\13HIWAT_IN\14HIWAT_OUT" \
2469 	"\15STOPPED\16EXCLUDE\17BYPASS\20ZOMBIE" \
2470 	"\21HOOK\22BUSY_IN\23BUSY_OUT"
2471 
2472 #define DB_PRINTSYM(name, addr) \
2473 	db_printf("%s  " #name ": ", sep); \
2474 	db_printsym((db_addr_t) addr, DB_STGY_ANY); \
2475 	db_printf("\n");
2476 
2477 static void
_db_show_devsw(const char * sep,const struct ttydevsw * tsw)2478 _db_show_devsw(const char *sep, const struct ttydevsw *tsw)
2479 {
2480 
2481 	db_printf("%sdevsw: ", sep);
2482 	db_printsym((db_addr_t)tsw, DB_STGY_ANY);
2483 	db_printf(" (%p)\n", tsw);
2484 	DB_PRINTSYM(open, tsw->tsw_open);
2485 	DB_PRINTSYM(close, tsw->tsw_close);
2486 	DB_PRINTSYM(outwakeup, tsw->tsw_outwakeup);
2487 	DB_PRINTSYM(inwakeup, tsw->tsw_inwakeup);
2488 	DB_PRINTSYM(ioctl, tsw->tsw_ioctl);
2489 	DB_PRINTSYM(param, tsw->tsw_param);
2490 	DB_PRINTSYM(modem, tsw->tsw_modem);
2491 	DB_PRINTSYM(mmap, tsw->tsw_mmap);
2492 	DB_PRINTSYM(pktnotify, tsw->tsw_pktnotify);
2493 	DB_PRINTSYM(free, tsw->tsw_free);
2494 }
2495 
2496 static void
_db_show_hooks(const char * sep,const struct ttyhook * th)2497 _db_show_hooks(const char *sep, const struct ttyhook *th)
2498 {
2499 
2500 	db_printf("%shook: ", sep);
2501 	db_printsym((db_addr_t)th, DB_STGY_ANY);
2502 	db_printf(" (%p)\n", th);
2503 	if (th == NULL)
2504 		return;
2505 	DB_PRINTSYM(rint, th->th_rint);
2506 	DB_PRINTSYM(rint_bypass, th->th_rint_bypass);
2507 	DB_PRINTSYM(rint_done, th->th_rint_done);
2508 	DB_PRINTSYM(rint_poll, th->th_rint_poll);
2509 	DB_PRINTSYM(getc_inject, th->th_getc_inject);
2510 	DB_PRINTSYM(getc_capture, th->th_getc_capture);
2511 	DB_PRINTSYM(getc_poll, th->th_getc_poll);
2512 	DB_PRINTSYM(close, th->th_close);
2513 }
2514 
2515 static void
_db_show_termios(const char * name,const struct termios * t)2516 _db_show_termios(const char *name, const struct termios *t)
2517 {
2518 
2519 	db_printf("%s: iflag 0x%x oflag 0x%x cflag 0x%x "
2520 	    "lflag 0x%x ispeed %u ospeed %u\n", name,
2521 	    t->c_iflag, t->c_oflag, t->c_cflag, t->c_lflag,
2522 	    t->c_ispeed, t->c_ospeed);
2523 }
2524 
2525 /* DDB command to show TTY statistics. */
DB_SHOW_COMMAND(tty,db_show_tty)2526 DB_SHOW_COMMAND(tty, db_show_tty)
2527 {
2528 	struct tty *tp;
2529 
2530 	if (!have_addr) {
2531 		db_printf("usage: show tty <addr>\n");
2532 		return;
2533 	}
2534 	tp = (struct tty *)addr;
2535 
2536 	db_printf("%p: %s\n", tp, tty_devname(tp));
2537 	db_printf("\tmtx: %p\n", tp->t_mtx);
2538 	db_printf("\tflags: 0x%b\n", tp->t_flags, TTY_FLAG_BITS);
2539 	db_printf("\trevokecnt: %u\n", tp->t_revokecnt);
2540 
2541 	/* Buffering mechanisms. */
2542 	db_printf("\tinq: %p begin %u linestart %u reprint %u end %u "
2543 	    "nblocks %u quota %u\n", &tp->t_inq, tp->t_inq.ti_begin,
2544 	    tp->t_inq.ti_linestart, tp->t_inq.ti_reprint, tp->t_inq.ti_end,
2545 	    tp->t_inq.ti_nblocks, tp->t_inq.ti_quota);
2546 	db_printf("\toutq: %p begin %u end %u nblocks %u quota %u\n",
2547 	    &tp->t_outq, tp->t_outq.to_begin, tp->t_outq.to_end,
2548 	    tp->t_outq.to_nblocks, tp->t_outq.to_quota);
2549 	db_printf("\tinlow: %zu\n", tp->t_inlow);
2550 	db_printf("\toutlow: %zu\n", tp->t_outlow);
2551 	_db_show_termios("\ttermios", &tp->t_termios);
2552 	db_printf("\twinsize: row %u col %u xpixel %u ypixel %u\n",
2553 	    tp->t_winsize.ws_row, tp->t_winsize.ws_col,
2554 	    tp->t_winsize.ws_xpixel, tp->t_winsize.ws_ypixel);
2555 	db_printf("\tcolumn: %u\n", tp->t_column);
2556 	db_printf("\twritepos: %u\n", tp->t_writepos);
2557 	db_printf("\tcompatflags: 0x%x\n", tp->t_compatflags);
2558 
2559 	/* Init/lock-state devices. */
2560 	_db_show_termios("\ttermios_init_in", &tp->t_termios_init_in);
2561 	_db_show_termios("\ttermios_init_out", &tp->t_termios_init_out);
2562 	_db_show_termios("\ttermios_lock_in", &tp->t_termios_lock_in);
2563 	_db_show_termios("\ttermios_lock_out", &tp->t_termios_lock_out);
2564 
2565 	/* Hooks */
2566 	_db_show_devsw("\t", tp->t_devsw);
2567 	_db_show_hooks("\t", tp->t_hook);
2568 
2569 	/* Process info. */
2570 	db_printf("\tpgrp: %p gid %d\n", tp->t_pgrp,
2571 	    tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
2572 	db_printf("\tsession: %p", tp->t_session);
2573 	if (tp->t_session != NULL)
2574 	    db_printf(" count %u leader %p tty %p sid %d login %s",
2575 		tp->t_session->s_count, tp->t_session->s_leader,
2576 		tp->t_session->s_ttyp, tp->t_session->s_sid,
2577 		tp->t_session->s_login);
2578 	db_printf("\n");
2579 	db_printf("\tsessioncnt: %u\n", tp->t_sessioncnt);
2580 	db_printf("\tdevswsoftc: %p\n", tp->t_devswsoftc);
2581 	db_printf("\thooksoftc: %p\n", tp->t_hooksoftc);
2582 	db_printf("\tdev: %p\n", tp->t_dev);
2583 }
2584 
2585 /* DDB command to list TTYs. */
DB_SHOW_ALL_COMMAND(ttys,db_show_all_ttys)2586 DB_SHOW_ALL_COMMAND(ttys, db_show_all_ttys)
2587 {
2588 	struct tty *tp;
2589 	size_t isiz, osiz;
2590 	int i, j;
2591 
2592 	/* Make the output look like `pstat -t'. */
2593 	db_printf("PTR        ");
2594 #if defined(__LP64__)
2595 	db_printf("        ");
2596 #endif
2597 	db_printf("      LINE   INQ  CAN  LIN  LOW  OUTQ  USE  LOW   "
2598 	    "COL  SESS  PGID STATE\n");
2599 
2600 	TAILQ_FOREACH(tp, &tty_list, t_list) {
2601 		isiz = tp->t_inq.ti_nblocks * TTYINQ_DATASIZE;
2602 		osiz = tp->t_outq.to_nblocks * TTYOUTQ_DATASIZE;
2603 
2604 		db_printf("%p %10s %5zu %4u %4u %4zu %5zu %4u %4zu %5u %5d "
2605 		    "%5d ", tp, tty_devname(tp), isiz,
2606 		    tp->t_inq.ti_linestart - tp->t_inq.ti_begin,
2607 		    tp->t_inq.ti_end - tp->t_inq.ti_linestart,
2608 		    isiz - tp->t_inlow, osiz,
2609 		    tp->t_outq.to_end - tp->t_outq.to_begin,
2610 		    osiz - tp->t_outlow, MIN(tp->t_column, 99999),
2611 		    tp->t_session ? tp->t_session->s_sid : 0,
2612 		    tp->t_pgrp ? tp->t_pgrp->pg_id : 0);
2613 
2614 		/* Flag bits. */
2615 		for (i = j = 0; ttystates[i].flag; i++)
2616 			if (tp->t_flags & ttystates[i].flag) {
2617 				db_printf("%c", ttystates[i].val);
2618 				j++;
2619 			}
2620 		if (j == 0)
2621 			db_printf("-");
2622 		db_printf("\n");
2623 	}
2624 }
2625 #endif /* DDB */
2626