1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
4 *
5 * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
6 * which can be dynamically activated and de-activated by the line
7 * discipline handling modules (like SLIP).
8 */
9
10#include <linux/types.h>
11#include <linux/termios.h>
12#include <linux/errno.h>
13#include <linux/sched/signal.h>
14#include <linux/kernel.h>
15#include <linux/major.h>
16#include <linux/tty.h>
17#include <linux/fcntl.h>
18#include <linux/string.h>
19#include <linux/mm.h>
20#include <linux/module.h>
21#include <linux/bitops.h>
22#include <linux/mutex.h>
23#include <linux/compat.h>
24
25#include <asm/io.h>
26#include <linux/uaccess.h>
27
28#undef TTY_DEBUG_WAIT_UNTIL_SENT
29
30#ifdef TTY_DEBUG_WAIT_UNTIL_SENT
31# define tty_debug_wait_until_sent(tty, f, args...) tty_debug(tty, f, ##args)
32#else
33# define tty_debug_wait_until_sent(tty, f, args...) do {} while (0)
34#endif
35
36#undef DEBUG
37
38/*
39 * Internal flag options for termios setting behavior
40 */
41#define TERMIOS_FLUSH 1
42#define TERMIOS_WAIT 2
43#define TERMIOS_TERMIO 4
44#define TERMIOS_OLD 8
45
46
47/**
48 * tty_chars_in_buffer - characters pending
49 * @tty: terminal
50 *
51 * Return the number of bytes of data in the device private
52 * output queue. If no private method is supplied there is assumed
53 * to be no queue on the device.
54 */
55
56int tty_chars_in_buffer(struct tty_struct *tty)
57{
58 if (tty->ops->chars_in_buffer)
59 return tty->ops->chars_in_buffer(tty);
60 else
61 return 0;
62}
63EXPORT_SYMBOL(tty_chars_in_buffer);
64
65/**
66 * tty_write_room - write queue space
67 * @tty: terminal
68 *
69 * Return the number of bytes that can be queued to this device
70 * at the present time. The result should be treated as a guarantee
71 * and the driver cannot offer a value it later shrinks by more than
72 * the number of bytes written. If no method is provided 2K is always
73 * returned and data may be lost as there will be no flow control.
74 */
75
76int tty_write_room(struct tty_struct *tty)
77{
78 if (tty->ops->write_room)
79 return tty->ops->write_room(tty);
80 return 2048;
81}
82EXPORT_SYMBOL(tty_write_room);
83
84/**
85 * tty_driver_flush_buffer - discard internal buffer
86 * @tty: terminal
87 *
88 * Discard the internal output buffer for this device. If no method
89 * is provided then either the buffer cannot be hardware flushed or
90 * there is no buffer driver side.
91 */
92void tty_driver_flush_buffer(struct tty_struct *tty)
93{
94 if (tty->ops->flush_buffer)
95 tty->ops->flush_buffer(tty);
96}
97EXPORT_SYMBOL(tty_driver_flush_buffer);
98
99/**
100 * tty_throttle - flow control
101 * @tty: terminal
102 *
103 * Indicate that a tty should stop transmitting data down the stack.
104 * Takes the termios rwsem to protect against parallel throttle/unthrottle
105 * and also to ensure the driver can consistently reference its own
106 * termios data at this point when implementing software flow control.
107 */
108
109void tty_throttle(struct tty_struct *tty)
110{
111 down_write(&tty->termios_rwsem);
112 /* check TTY_THROTTLED first so it indicates our state */
113 if (!test_and_set_bit(TTY_THROTTLED, &tty->flags) &&
114 tty->ops->throttle)
115 tty->ops->throttle(tty);
116 tty->flow_change = 0;
117 up_write(&tty->termios_rwsem);
118}
119EXPORT_SYMBOL(tty_throttle);
120
121/**
122 * tty_unthrottle - flow control
123 * @tty: terminal
124 *
125 * Indicate that a tty may continue transmitting data down the stack.
126 * Takes the termios rwsem to protect against parallel throttle/unthrottle
127 * and also to ensure the driver can consistently reference its own
128 * termios data at this point when implementing software flow control.
129 *
130 * Drivers should however remember that the stack can issue a throttle,
131 * then change flow control method, then unthrottle.
132 */
133
134void tty_unthrottle(struct tty_struct *tty)
135{
136 down_write(&tty->termios_rwsem);
137 if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) &&
138 tty->ops->unthrottle)
139 tty->ops->unthrottle(tty);
140 tty->flow_change = 0;
141 up_write(&tty->termios_rwsem);
142}
143EXPORT_SYMBOL(tty_unthrottle);
144
145/**
146 * tty_throttle_safe - flow control
147 * @tty: terminal
148 *
149 * Similar to tty_throttle() but will only attempt throttle
150 * if tty->flow_change is TTY_THROTTLE_SAFE. Prevents an accidental
151 * throttle due to race conditions when throttling is conditional
152 * on factors evaluated prior to throttling.
153 *
154 * Returns 0 if tty is throttled (or was already throttled)
155 */
156
157int tty_throttle_safe(struct tty_struct *tty)
158{
159 int ret = 0;
160
161 mutex_lock(&tty->throttle_mutex);
162 if (!tty_throttled(tty)) {
163 if (tty->flow_change != TTY_THROTTLE_SAFE)
164 ret = 1;
165 else {
166 set_bit(TTY_THROTTLED, &tty->flags);
167 if (tty->ops->throttle)
168 tty->ops->throttle(tty);
169 }
170 }
171 mutex_unlock(&tty->throttle_mutex);
172
173 return ret;
174}
175
176/**
177 * tty_unthrottle_safe - flow control
178 * @tty: terminal
179 *
180 * Similar to tty_unthrottle() but will only attempt unthrottle
181 * if tty->flow_change is TTY_UNTHROTTLE_SAFE. Prevents an accidental
182 * unthrottle due to race conditions when unthrottling is conditional
183 * on factors evaluated prior to unthrottling.
184 *
185 * Returns 0 if tty is unthrottled (or was already unthrottled)
186 */
187
188int tty_unthrottle_safe(struct tty_struct *tty)
189{
190 int ret = 0;
191
192 mutex_lock(&tty->throttle_mutex);
193 if (tty_throttled(tty)) {
194 if (tty->flow_change != TTY_UNTHROTTLE_SAFE)
195 ret = 1;
196 else {
197 clear_bit(TTY_THROTTLED, &tty->flags);
198 if (tty->ops->unthrottle)
199 tty->ops->unthrottle(tty);
200 }
201 }
202 mutex_unlock(&tty->throttle_mutex);
203
204 return ret;
205}
206
207/**
208 * tty_wait_until_sent - wait for I/O to finish
209 * @tty: tty we are waiting for
210 * @timeout: how long we will wait
211 *
212 * Wait for characters pending in a tty driver to hit the wire, or
213 * for a timeout to occur (eg due to flow control)
214 *
215 * Locking: none
216 */
217
218void tty_wait_until_sent(struct tty_struct *tty, long timeout)
219{
220 tty_debug_wait_until_sent(tty, "wait until sent, timeout=%ld\n", timeout);
221
222 if (!timeout)
223 timeout = MAX_SCHEDULE_TIMEOUT;
224
225 timeout = wait_event_interruptible_timeout(tty->write_wait,
226 !tty_chars_in_buffer(tty), timeout);
227 if (timeout <= 0)
228 return;
229
230 if (timeout == MAX_SCHEDULE_TIMEOUT)
231 timeout = 0;
232
233 if (tty->ops->wait_until_sent)
234 tty->ops->wait_until_sent(tty, timeout);
235}
236EXPORT_SYMBOL(tty_wait_until_sent);
237
238
239/*
240 * Termios Helper Methods
241 */
242
243static void unset_locked_termios(struct tty_struct *tty, struct ktermios *old)
244{
245 struct ktermios *termios = &tty->termios;
246 struct ktermios *locked = &tty->termios_locked;
247 int i;
248
249#define NOSET_MASK(x, y, z) (x = ((x) & ~(z)) | ((y) & (z)))
250
251 NOSET_MASK(termios->c_iflag, old->c_iflag, locked->c_iflag);
252 NOSET_MASK(termios->c_oflag, old->c_oflag, locked->c_oflag);
253 NOSET_MASK(termios->c_cflag, old->c_cflag, locked->c_cflag);
254 NOSET_MASK(termios->c_lflag, old->c_lflag, locked->c_lflag);
255 termios->c_line = locked->c_line ? old->c_line : termios->c_line;
256 for (i = 0; i < NCCS; i++)
257 termios->c_cc[i] = locked->c_cc[i] ?
258 old->c_cc[i] : termios->c_cc[i];
259 /* FIXME: What should we do for i/ospeed */
260}
261
262/**
263 * tty_termios_copy_hw - copy hardware settings
264 * @new: New termios
265 * @old: Old termios
266 *
267 * Propagate the hardware specific terminal setting bits from
268 * the old termios structure to the new one. This is used in cases
269 * where the hardware does not support reconfiguration or as a helper
270 * in some cases where only minimal reconfiguration is supported
271 */
272
273void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old)
274{
275 /* The bits a dumb device handles in software. Smart devices need
276 to always provide a set_termios method */
277 new->c_cflag &= HUPCL | CREAD | CLOCAL;
278 new->c_cflag |= old->c_cflag & ~(HUPCL | CREAD | CLOCAL);
279 new->c_ispeed = old->c_ispeed;
280 new->c_ospeed = old->c_ospeed;
281}
282EXPORT_SYMBOL(tty_termios_copy_hw);
283
284/**
285 * tty_termios_hw_change - check for setting change
286 * @a: termios
287 * @b: termios to compare
288 *
289 * Check if any of the bits that affect a dumb device have changed
290 * between the two termios structures, or a speed change is needed.
291 */
292
293int tty_termios_hw_change(const struct ktermios *a, const struct ktermios *b)
294{
295 if (a->c_ispeed != b->c_ispeed || a->c_ospeed != b->c_ospeed)
296 return 1;
297 if ((a->c_cflag ^ b->c_cflag) & ~(HUPCL | CREAD | CLOCAL))
298 return 1;
299 return 0;
300}
301EXPORT_SYMBOL(tty_termios_hw_change);
302
303/**
304 * tty_set_termios - update termios values
305 * @tty: tty to update
306 * @new_termios: desired new value
307 *
308 * Perform updates to the termios values set on this terminal.
309 * A master pty's termios should never be set.
310 *
311 * Locking: termios_rwsem
312 */
313
314int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios)
315{
316 struct ktermios old_termios;
317 struct tty_ldisc *ld;
318
319 WARN_ON(tty->driver->type == TTY_DRIVER_TYPE_PTY &&
320 tty->driver->subtype == PTY_TYPE_MASTER);
321 /*
322 * Perform the actual termios internal changes under lock.
323 */
324
325
326 /* FIXME: we need to decide on some locking/ordering semantics
327 for the set_termios notification eventually */
328 down_write(&tty->termios_rwsem);
329 old_termios = tty->termios;
330 tty->termios = *new_termios;
331 unset_locked_termios(tty, &old_termios);
332
333 if (tty->ops->set_termios)
334 tty->ops->set_termios(tty, &old_termios);
335 else
336 tty_termios_copy_hw(&tty->termios, &old_termios);
337
338 ld = tty_ldisc_ref(tty);
339 if (ld != NULL) {
340 if (ld->ops->set_termios)
341 ld->ops->set_termios(tty, &old_termios);
342 tty_ldisc_deref(ld);
343 }
344 up_write(&tty->termios_rwsem);
345 return 0;
346}
347EXPORT_SYMBOL_GPL(tty_set_termios);
348
349/**
350 * set_termios - set termios values for a tty
351 * @tty: terminal device
352 * @arg: user data
353 * @opt: option information
354 *
355 * Helper function to prepare termios data and run necessary other
356 * functions before using tty_set_termios to do the actual changes.
357 *
358 * Locking:
359 * Called functions take ldisc and termios_rwsem locks
360 */
361
362static int set_termios(struct tty_struct *tty, void __user *arg, int opt)
363{
364 struct ktermios tmp_termios;
365 struct tty_ldisc *ld;
366 int retval = tty_check_change(tty);
367
368 if (retval)
369 return retval;
370
371 down_read(&tty->termios_rwsem);
372 tmp_termios = tty->termios;
373 up_read(&tty->termios_rwsem);
374
375 if (opt & TERMIOS_TERMIO) {
376 if (user_termio_to_kernel_termios(&tmp_termios,
377 (struct termio __user *)arg))
378 return -EFAULT;
379#ifdef TCGETS2
380 } else if (opt & TERMIOS_OLD) {
381 if (user_termios_to_kernel_termios_1(&tmp_termios,
382 (struct termios __user *)arg))
383 return -EFAULT;
384 } else {
385 if (user_termios_to_kernel_termios(&tmp_termios,
386 (struct termios2 __user *)arg))
387 return -EFAULT;
388 }
389#else
390 } else if (user_termios_to_kernel_termios(&tmp_termios,
391 (struct termios __user *)arg))
392 return -EFAULT;
393#endif
394
395 /* If old style Bfoo values are used then load c_ispeed/c_ospeed
396 * with the real speed so its unconditionally usable */
397 tmp_termios.c_ispeed = tty_termios_input_baud_rate(&tmp_termios);
398 tmp_termios.c_ospeed = tty_termios_baud_rate(&tmp_termios);
399
400 ld = tty_ldisc_ref(tty);
401
402 if (ld != NULL) {
403 if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
404 ld->ops->flush_buffer(tty);
405 tty_ldisc_deref(ld);
406 }
407
408 if (opt & TERMIOS_WAIT) {
409 tty_wait_until_sent(tty, 0);
410 if (signal_pending(current))
411 return -ERESTARTSYS;
412 }
413
414 tty_set_termios(tty, &tmp_termios);
415
416 /* FIXME: Arguably if tmp_termios == tty->termios AND the
417 actual requested termios was not tmp_termios then we may
418 want to return an error as no user requested change has
419 succeeded */
420 return 0;
421}
422
423static void copy_termios(struct tty_struct *tty, struct ktermios *kterm)
424{
425 down_read(&tty->termios_rwsem);
426 *kterm = tty->termios;
427 up_read(&tty->termios_rwsem);
428}
429
430static void copy_termios_locked(struct tty_struct *tty, struct ktermios *kterm)
431{
432 down_read(&tty->termios_rwsem);
433 *kterm = tty->termios_locked;
434 up_read(&tty->termios_rwsem);
435}
436
437static int get_termio(struct tty_struct *tty, struct termio __user *termio)
438{
439 struct ktermios kterm;
440 copy_termios(tty, &kterm);
441 if (kernel_termios_to_user_termio(termio, &kterm))
442 return -EFAULT;
443 return 0;
444}
445
446
447#ifdef TCGETX
448
449/**
450 * set_termiox - set termiox fields if possible
451 * @tty: terminal
452 * @arg: termiox structure from user
453 * @opt: option flags for ioctl type
454 *
455 * Implement the device calling points for the SYS5 termiox ioctl
456 * interface in Linux
457 */
458
459static int set_termiox(struct tty_struct *tty, void __user *arg, int opt)
460{
461 struct termiox tnew;
462 struct tty_ldisc *ld;
463
464 if (tty->termiox == NULL)
465 return -EINVAL;
466 if (copy_from_user(&tnew, arg, sizeof(struct termiox)))
467 return -EFAULT;
468
469 ld = tty_ldisc_ref(tty);
470 if (ld != NULL) {
471 if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
472 ld->ops->flush_buffer(tty);
473 tty_ldisc_deref(ld);
474 }
475 if (opt & TERMIOS_WAIT) {
476 tty_wait_until_sent(tty, 0);
477 if (signal_pending(current))
478 return -ERESTARTSYS;
479 }
480
481 down_write(&tty->termios_rwsem);
482 if (tty->ops->set_termiox)
483 tty->ops->set_termiox(tty, &tnew);
484 up_write(&tty->termios_rwsem);
485 return 0;
486}
487
488#endif
489
490
491#ifdef TIOCGETP
492/*
493 * These are deprecated, but there is limited support..
494 *
495 * The "sg_flags" translation is a joke..
496 */
497static int get_sgflags(struct tty_struct *tty)
498{
499 int flags = 0;
500
501 if (!L_ICANON(tty)) {
502 if (L_ISIG(tty))
503 flags |= 0x02; /* cbreak */
504 else
505 flags |= 0x20; /* raw */
506 }
507 if (L_ECHO(tty))
508 flags |= 0x08; /* echo */
509 if (O_OPOST(tty))
510 if (O_ONLCR(tty))
511 flags |= 0x10; /* crmod */
512 return flags;
513}
514
515static int get_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
516{
517 struct sgttyb tmp;
518
519 down_read(&tty->termios_rwsem);
520 tmp.sg_ispeed = tty->termios.c_ispeed;
521 tmp.sg_ospeed = tty->termios.c_ospeed;
522 tmp.sg_erase = tty->termios.c_cc[VERASE];
523 tmp.sg_kill = tty->termios.c_cc[VKILL];
524 tmp.sg_flags = get_sgflags(tty);
525 up_read(&tty->termios_rwsem);
526
527 return copy_to_user(sgttyb, &tmp, sizeof(tmp)) ? -EFAULT : 0;
528}
529
530static void set_sgflags(struct ktermios *termios, int flags)
531{
532 termios->c_iflag = ICRNL | IXON;
533 termios->c_oflag = 0;
534 termios->c_lflag = ISIG | ICANON;
535 if (flags & 0x02) { /* cbreak */
536 termios->c_iflag = 0;
537 termios->c_lflag &= ~ICANON;
538 }
539 if (flags & 0x08) { /* echo */
540 termios->c_lflag |= ECHO | ECHOE | ECHOK |
541 ECHOCTL | ECHOKE | IEXTEN;
542 }
543 if (flags & 0x10) { /* crmod */
544 termios->c_oflag |= OPOST | ONLCR;
545 }
546 if (flags & 0x20) { /* raw */
547 termios->c_iflag = 0;
548 termios->c_lflag &= ~(ISIG | ICANON);
549 }
550 if (!(termios->c_lflag & ICANON)) {
551 termios->c_cc[VMIN] = 1;
552 termios->c_cc[VTIME] = 0;
553 }
554}
555
556/**
557 * set_sgttyb - set legacy terminal values
558 * @tty: tty structure
559 * @sgttyb: pointer to old style terminal structure
560 *
561 * Updates a terminal from the legacy BSD style terminal information
562 * structure.
563 *
564 * Locking: termios_rwsem
565 */
566
567static int set_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
568{
569 int retval;
570 struct sgttyb tmp;
571 struct ktermios termios;
572
573 retval = tty_check_change(tty);
574 if (retval)
575 return retval;
576
577 if (copy_from_user(&tmp, sgttyb, sizeof(tmp)))
578 return -EFAULT;
579
580 down_write(&tty->termios_rwsem);
581 termios = tty->termios;
582 termios.c_cc[VERASE] = tmp.sg_erase;
583 termios.c_cc[VKILL] = tmp.sg_kill;
584 set_sgflags(&termios, tmp.sg_flags);
585 /* Try and encode into Bfoo format */
586#ifdef BOTHER
587 tty_termios_encode_baud_rate(&termios, termios.c_ispeed,
588 termios.c_ospeed);
589#endif
590 up_write(&tty->termios_rwsem);
591 tty_set_termios(tty, &termios);
592 return 0;
593}
594#endif
595
596#ifdef TIOCGETC
597static int get_tchars(struct tty_struct *tty, struct tchars __user *tchars)
598{
599 struct tchars tmp;
600
601 down_read(&tty->termios_rwsem);
602 tmp.t_intrc = tty->termios.c_cc[VINTR];
603 tmp.t_quitc = tty->termios.c_cc[VQUIT];
604 tmp.t_startc = tty->termios.c_cc[VSTART];
605 tmp.t_stopc = tty->termios.c_cc[VSTOP];
606 tmp.t_eofc = tty->termios.c_cc[VEOF];
607 tmp.t_brkc = tty->termios.c_cc[VEOL2]; /* what is brkc anyway? */
608 up_read(&tty->termios_rwsem);
609 return copy_to_user(tchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
610}
611
612static int set_tchars(struct tty_struct *tty, struct tchars __user *tchars)
613{
614 struct tchars tmp;
615
616 if (copy_from_user(&tmp, tchars, sizeof(tmp)))
617 return -EFAULT;
618 down_write(&tty->termios_rwsem);
619 tty->termios.c_cc[VINTR] = tmp.t_intrc;
620 tty->termios.c_cc[VQUIT] = tmp.t_quitc;
621 tty->termios.c_cc[VSTART] = tmp.t_startc;
622 tty->termios.c_cc[VSTOP] = tmp.t_stopc;
623 tty->termios.c_cc[VEOF] = tmp.t_eofc;
624 tty->termios.c_cc[VEOL2] = tmp.t_brkc; /* what is brkc anyway? */
625 up_write(&tty->termios_rwsem);
626 return 0;
627}
628#endif
629
630#ifdef TIOCGLTC
631static int get_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
632{
633 struct ltchars tmp;
634
635 down_read(&tty->termios_rwsem);
636 tmp.t_suspc = tty->termios.c_cc[VSUSP];
637 /* what is dsuspc anyway? */
638 tmp.t_dsuspc = tty->termios.c_cc[VSUSP];
639 tmp.t_rprntc = tty->termios.c_cc[VREPRINT];
640 /* what is flushc anyway? */
641 tmp.t_flushc = tty->termios.c_cc[VEOL2];
642 tmp.t_werasc = tty->termios.c_cc[VWERASE];
643 tmp.t_lnextc = tty->termios.c_cc[VLNEXT];
644 up_read(&tty->termios_rwsem);
645 return copy_to_user(ltchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
646}
647
648static int set_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
649{
650 struct ltchars tmp;
651
652 if (copy_from_user(&tmp, ltchars, sizeof(tmp)))
653 return -EFAULT;
654
655 down_write(&tty->termios_rwsem);
656 tty->termios.c_cc[VSUSP] = tmp.t_suspc;
657 /* what is dsuspc anyway? */
658 tty->termios.c_cc[VEOL2] = tmp.t_dsuspc;
659 tty->termios.c_cc[VREPRINT] = tmp.t_rprntc;
660 /* what is flushc anyway? */
661 tty->termios.c_cc[VEOL2] = tmp.t_flushc;
662 tty->termios.c_cc[VWERASE] = tmp.t_werasc;
663 tty->termios.c_cc[VLNEXT] = tmp.t_lnextc;
664 up_write(&tty->termios_rwsem);
665 return 0;
666}
667#endif
668
669/**
670 * tty_change_softcar - carrier change ioctl helper
671 * @tty: tty to update
672 * @arg: enable/disable CLOCAL
673 *
674 * Perform a change to the CLOCAL state and call into the driver
675 * layer to make it visible. All done with the termios rwsem
676 */
677
678static int tty_change_softcar(struct tty_struct *tty, int arg)
679{
680 int ret = 0;
681 int bit = arg ? CLOCAL : 0;
682 struct ktermios old;
683
684 down_write(&tty->termios_rwsem);
685 old = tty->termios;
686 tty->termios.c_cflag &= ~CLOCAL;
687 tty->termios.c_cflag |= bit;
688 if (tty->ops->set_termios)
689 tty->ops->set_termios(tty, &old);
690 if (C_CLOCAL(tty) != bit)
691 ret = -EINVAL;
692 up_write(&tty->termios_rwsem);
693 return ret;
694}
695
696/**
697 * tty_mode_ioctl - mode related ioctls
698 * @tty: tty for the ioctl
699 * @file: file pointer for the tty
700 * @cmd: command
701 * @arg: ioctl argument
702 *
703 * Perform non line discipline specific mode control ioctls. This
704 * is designed to be called by line disciplines to ensure they provide
705 * consistent mode setting.
706 */
707
708int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
709 unsigned int cmd, unsigned long arg)
710{
711 struct tty_struct *real_tty;
712 void __user *p = (void __user *)arg;
713 int ret = 0;
714 struct ktermios kterm;
715
716 BUG_ON(file == NULL);
717
718 if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
719 tty->driver->subtype == PTY_TYPE_MASTER)
720 real_tty = tty->link;
721 else
722 real_tty = tty;
723
724 switch (cmd) {
725#ifdef TIOCGETP
726 case TIOCGETP:
727 return get_sgttyb(real_tty, (struct sgttyb __user *) arg);
728 case TIOCSETP:
729 case TIOCSETN:
730 return set_sgttyb(real_tty, (struct sgttyb __user *) arg);
731#endif
732#ifdef TIOCGETC
733 case TIOCGETC:
734 return get_tchars(real_tty, p);
735 case TIOCSETC:
736 return set_tchars(real_tty, p);
737#endif
738#ifdef TIOCGLTC
739 case TIOCGLTC:
740 return get_ltchars(real_tty, p);
741 case TIOCSLTC:
742 return set_ltchars(real_tty, p);
743#endif
744 case TCSETSF:
745 return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_OLD);
746 case TCSETSW:
747 return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_OLD);
748 case TCSETS:
749 return set_termios(real_tty, p, TERMIOS_OLD);
750#ifndef TCGETS2
751 case TCGETS:
752 copy_termios(real_tty, &kterm);
753 if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
754 ret = -EFAULT;
755 return ret;
756#else
757 case TCGETS:
758 copy_termios(real_tty, &kterm);
759 if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
760 ret = -EFAULT;
761 return ret;
762 case TCGETS2:
763 copy_termios(real_tty, &kterm);
764 if (kernel_termios_to_user_termios((struct termios2 __user *)arg, &kterm))
765 ret = -EFAULT;
766 return ret;
767 case TCSETSF2:
768 return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT);
769 case TCSETSW2:
770 return set_termios(real_tty, p, TERMIOS_WAIT);
771 case TCSETS2:
772 return set_termios(real_tty, p, 0);
773#endif
774 case TCGETA:
775 return get_termio(real_tty, p);
776 case TCSETAF:
777 return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_TERMIO);
778 case TCSETAW:
779 return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_TERMIO);
780 case TCSETA:
781 return set_termios(real_tty, p, TERMIOS_TERMIO);
782#ifndef TCGETS2
783 case TIOCGLCKTRMIOS:
784 copy_termios_locked(real_tty, &kterm);
785 if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
786 ret = -EFAULT;
787 return ret;
788 case TIOCSLCKTRMIOS:
789 if (!capable(CAP_SYS_ADMIN))
790 return -EPERM;
791 copy_termios_locked(real_tty, &kterm);
792 if (user_termios_to_kernel_termios(&kterm,
793 (struct termios __user *) arg))
794 return -EFAULT;
795 down_write(&real_tty->termios_rwsem);
796 real_tty->termios_locked = kterm;
797 up_write(&real_tty->termios_rwsem);
798 return 0;
799#else
800 case TIOCGLCKTRMIOS:
801 copy_termios_locked(real_tty, &kterm);
802 if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
803 ret = -EFAULT;
804 return ret;
805 case TIOCSLCKTRMIOS:
806 if (!capable(CAP_SYS_ADMIN))
807 return -EPERM;
808 copy_termios_locked(real_tty, &kterm);
809 if (user_termios_to_kernel_termios_1(&kterm,
810 (struct termios __user *) arg))
811 return -EFAULT;
812 down_write(&real_tty->termios_rwsem);
813 real_tty->termios_locked = kterm;
814 up_write(&real_tty->termios_rwsem);
815 return ret;
816#endif
817#ifdef TCGETX
818 case TCGETX: {
819 struct termiox ktermx;
820 if (real_tty->termiox == NULL)
821 return -EINVAL;
822 down_read(&real_tty->termios_rwsem);
823 memcpy(&ktermx, real_tty->termiox, sizeof(struct termiox));
824 up_read(&real_tty->termios_rwsem);
825 if (copy_to_user(p, &ktermx, sizeof(struct termiox)))
826 ret = -EFAULT;
827 return ret;
828 }
829 case TCSETX:
830 return set_termiox(real_tty, p, 0);
831 case TCSETXW:
832 return set_termiox(real_tty, p, TERMIOS_WAIT);
833 case TCSETXF:
834 return set_termiox(real_tty, p, TERMIOS_FLUSH);
835#endif
836 case TIOCGSOFTCAR:
837 copy_termios(real_tty, &kterm);
838 ret = put_user((kterm.c_cflag & CLOCAL) ? 1 : 0,
839 (int __user *)arg);
840 return ret;
841 case TIOCSSOFTCAR:
842 if (get_user(arg, (unsigned int __user *) arg))
843 return -EFAULT;
844 return tty_change_softcar(real_tty, arg);
845 default:
846 return -ENOIOCTLCMD;
847 }
848}
849EXPORT_SYMBOL_GPL(tty_mode_ioctl);
850
851
852/* Caller guarantees ldisc reference is held */
853static int __tty_perform_flush(struct tty_struct *tty, unsigned long arg)
854{
855 struct tty_ldisc *ld = tty->ldisc;
856
857 switch (arg) {
858 case TCIFLUSH:
859 if (ld && ld->ops->flush_buffer) {
860 ld->ops->flush_buffer(tty);
861 tty_unthrottle(tty);
862 }
863 break;
864 case TCIOFLUSH:
865 if (ld && ld->ops->flush_buffer) {
866 ld->ops->flush_buffer(tty);
867 tty_unthrottle(tty);
868 }
869 /* fall through */
870 case TCOFLUSH:
871 tty_driver_flush_buffer(tty);
872 break;
873 default:
874 return -EINVAL;
875 }
876 return 0;
877}
878
879int tty_perform_flush(struct tty_struct *tty, unsigned long arg)
880{
881 struct tty_ldisc *ld;
882 int retval = tty_check_change(tty);
883 if (retval)
884 return retval;
885
886 ld = tty_ldisc_ref_wait(tty);
887 retval = __tty_perform_flush(tty, arg);
888 if (ld)
889 tty_ldisc_deref(ld);
890 return retval;
891}
892EXPORT_SYMBOL_GPL(tty_perform_flush);
893
894int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
895 unsigned int cmd, unsigned long arg)
896{
897 int retval;
898
899 switch (cmd) {
900 case TCXONC:
901 retval = tty_check_change(tty);
902 if (retval)
903 return retval;
904 switch (arg) {
905 case TCOOFF:
906 spin_lock_irq(&tty->flow_lock);
907 if (!tty->flow_stopped) {
908 tty->flow_stopped = 1;
909 __stop_tty(tty);
910 }
911 spin_unlock_irq(&tty->flow_lock);
912 break;
913 case TCOON:
914 spin_lock_irq(&tty->flow_lock);
915 if (tty->flow_stopped) {
916 tty->flow_stopped = 0;
917 __start_tty(tty);
918 }
919 spin_unlock_irq(&tty->flow_lock);
920 break;
921 case TCIOFF:
922 if (STOP_CHAR(tty) != __DISABLED_CHAR)
923 retval = tty_send_xchar(tty, STOP_CHAR(tty));
924 break;
925 case TCION:
926 if (START_CHAR(tty) != __DISABLED_CHAR)
927 retval = tty_send_xchar(tty, START_CHAR(tty));
928 break;
929 default:
930 return -EINVAL;
931 }
932 return retval;
933 case TCFLSH:
934 retval = tty_check_change(tty);
935 if (retval)
936 return retval;
937 return __tty_perform_flush(tty, arg);
938 default:
939 /* Try the mode commands */
940 return tty_mode_ioctl(tty, file, cmd, arg);
941 }
942}
943EXPORT_SYMBOL(n_tty_ioctl_helper);
944