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