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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/bits.h>
11#include <linux/types.h>
12#include <linux/termios.h>
13#include <linux/errno.h>
14#include <linux/sched/signal.h>
15#include <linux/kernel.h>
16#include <linux/major.h>
17#include <linux/tty.h>
18#include <linux/fcntl.h>
19#include <linux/string.h>
20#include <linux/mm.h>
21#include <linux/module.h>
22#include <linux/bitops.h>
23#include <linux/mutex.h>
24#include <linux/compat.h>
25#include <linux/termios_internal.h>
26#include "tty.h"
27
28#include <asm/io.h>
29#include <linux/uaccess.h>
30
31#undef DEBUG
32
33/*
34 * Internal flag options for termios setting behavior
35 */
36#define TERMIOS_FLUSH BIT(0)
37#define TERMIOS_WAIT BIT(1)
38#define TERMIOS_TERMIO BIT(2)
39#define TERMIOS_OLD BIT(3)
40
41/**
42 * tty_chars_in_buffer - characters pending
43 * @tty: terminal
44 *
45 * Returns: the number of bytes of data in the device private output queue. If
46 * no private method is supplied there is assumed to be no queue on the device.
47 */
48unsigned int tty_chars_in_buffer(struct tty_struct *tty)
49{
50 if (tty->ops->chars_in_buffer)
51 return tty->ops->chars_in_buffer(tty);
52 return 0;
53}
54EXPORT_SYMBOL(tty_chars_in_buffer);
55
56/**
57 * tty_write_room - write queue space
58 * @tty: terminal
59 *
60 * Returns: the number of bytes that can be queued to this device at the present
61 * time. The result should be treated as a guarantee and the driver cannot
62 * offer a value it later shrinks by more than the number of bytes written. If
63 * no method is provided, 2K is always returned and data may be lost as there
64 * will be no flow control.
65 */
66unsigned int tty_write_room(struct tty_struct *tty)
67{
68 if (tty->ops->write_room)
69 return tty->ops->write_room(tty);
70 return 2048;
71}
72EXPORT_SYMBOL(tty_write_room);
73
74/**
75 * tty_driver_flush_buffer - discard internal buffer
76 * @tty: terminal
77 *
78 * Discard the internal output buffer for this device. If no method is provided,
79 * then either the buffer cannot be hardware flushed or there is no buffer
80 * driver side.
81 */
82void tty_driver_flush_buffer(struct tty_struct *tty)
83{
84 if (tty->ops->flush_buffer)
85 tty->ops->flush_buffer(tty);
86}
87EXPORT_SYMBOL(tty_driver_flush_buffer);
88
89/**
90 * tty_unthrottle - flow control
91 * @tty: terminal
92 *
93 * Indicate that a @tty may continue transmitting data down the stack. Takes
94 * the &tty_struct->termios_rwsem to protect against parallel
95 * throttle/unthrottle and also to ensure the driver can consistently reference
96 * its own termios data at this point when implementing software flow control.
97 *
98 * Drivers should however remember that the stack can issue a throttle, then
99 * change flow control method, then unthrottle.
100 */
101void tty_unthrottle(struct tty_struct *tty)
102{
103 down_write(&tty->termios_rwsem);
104 if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) &&
105 tty->ops->unthrottle)
106 tty->ops->unthrottle(tty);
107 tty->flow_change = TTY_FLOW_NO_CHANGE;
108 up_write(&tty->termios_rwsem);
109}
110EXPORT_SYMBOL(tty_unthrottle);
111
112/**
113 * tty_throttle_safe - flow control
114 * @tty: terminal
115 *
116 * Indicate that a @tty should stop transmitting data down the stack.
117 * tty_throttle_safe() will only attempt throttle if @tty->flow_change is
118 * %TTY_THROTTLE_SAFE. Prevents an accidental throttle due to race conditions
119 * when throttling is conditional on factors evaluated prior to throttling.
120 *
121 * Returns: %true if @tty is throttled (or was already throttled)
122 */
123bool tty_throttle_safe(struct tty_struct *tty)
124{
125 bool ret = true;
126
127 mutex_lock(&tty->throttle_mutex);
128 if (!tty_throttled(tty)) {
129 if (tty->flow_change != TTY_THROTTLE_SAFE)
130 ret = false;
131 else {
132 set_bit(TTY_THROTTLED, &tty->flags);
133 if (tty->ops->throttle)
134 tty->ops->throttle(tty);
135 }
136 }
137 mutex_unlock(&tty->throttle_mutex);
138
139 return ret;
140}
141
142/**
143 * tty_unthrottle_safe - flow control
144 * @tty: terminal
145 *
146 * Similar to tty_unthrottle() but will only attempt unthrottle if
147 * @tty->flow_change is %TTY_UNTHROTTLE_SAFE. Prevents an accidental unthrottle
148 * due to race conditions when unthrottling is conditional on factors evaluated
149 * prior to unthrottling.
150 *
151 * Returns: %true if @tty is unthrottled (or was already unthrottled)
152 */
153bool tty_unthrottle_safe(struct tty_struct *tty)
154{
155 bool ret = true;
156
157 mutex_lock(&tty->throttle_mutex);
158 if (tty_throttled(tty)) {
159 if (tty->flow_change != TTY_UNTHROTTLE_SAFE)
160 ret = false;
161 else {
162 clear_bit(TTY_THROTTLED, &tty->flags);
163 if (tty->ops->unthrottle)
164 tty->ops->unthrottle(tty);
165 }
166 }
167 mutex_unlock(&tty->throttle_mutex);
168
169 return ret;
170}
171
172/**
173 * tty_wait_until_sent - wait for I/O to finish
174 * @tty: tty we are waiting for
175 * @timeout: how long we will wait
176 *
177 * Wait for characters pending in a tty driver to hit the wire, or for a
178 * timeout to occur (eg due to flow control).
179 *
180 * Locking: none
181 */
182
183void tty_wait_until_sent(struct tty_struct *tty, long timeout)
184{
185 if (!timeout)
186 timeout = MAX_SCHEDULE_TIMEOUT;
187
188 timeout = wait_event_interruptible_timeout(tty->write_wait,
189 !tty_chars_in_buffer(tty), timeout);
190 if (timeout <= 0)
191 return;
192
193 if (timeout == MAX_SCHEDULE_TIMEOUT)
194 timeout = 0;
195
196 if (tty->ops->wait_until_sent)
197 tty->ops->wait_until_sent(tty, timeout);
198}
199EXPORT_SYMBOL(tty_wait_until_sent);
200
201
202/*
203 * Termios Helper Methods
204 */
205
206static void unset_locked_termios(struct tty_struct *tty, const struct ktermios *old)
207{
208 struct ktermios *termios = &tty->termios;
209 struct ktermios *locked = &tty->termios_locked;
210 int i;
211
212#define NOSET_MASK(x, y, z) (x = ((x) & ~(z)) | ((y) & (z)))
213
214 NOSET_MASK(termios->c_iflag, old->c_iflag, locked->c_iflag);
215 NOSET_MASK(termios->c_oflag, old->c_oflag, locked->c_oflag);
216 NOSET_MASK(termios->c_cflag, old->c_cflag, locked->c_cflag);
217 NOSET_MASK(termios->c_lflag, old->c_lflag, locked->c_lflag);
218 termios->c_line = locked->c_line ? old->c_line : termios->c_line;
219 for (i = 0; i < NCCS; i++)
220 termios->c_cc[i] = locked->c_cc[i] ?
221 old->c_cc[i] : termios->c_cc[i];
222 /* FIXME: What should we do for i/ospeed */
223}
224
225/**
226 * tty_termios_copy_hw - copy hardware settings
227 * @new: new termios
228 * @old: old termios
229 *
230 * Propagate the hardware specific terminal setting bits from the @old termios
231 * structure to the @new one. This is used in cases where the hardware does not
232 * support reconfiguration or as a helper in some cases where only minimal
233 * reconfiguration is supported.
234 */
235void tty_termios_copy_hw(struct ktermios *new, const struct ktermios *old)
236{
237 /* The bits a dumb device handles in software. Smart devices need
238 to always provide a set_termios method */
239 new->c_cflag &= HUPCL | CREAD | CLOCAL;
240 new->c_cflag |= old->c_cflag & ~(HUPCL | CREAD | CLOCAL);
241 new->c_ispeed = old->c_ispeed;
242 new->c_ospeed = old->c_ospeed;
243}
244EXPORT_SYMBOL(tty_termios_copy_hw);
245
246/**
247 * tty_termios_hw_change - check for setting change
248 * @a: termios
249 * @b: termios to compare
250 *
251 * Check if any of the bits that affect a dumb device have changed between the
252 * two termios structures, or a speed change is needed.
253 *
254 * Returns: %true if change is needed
255 */
256bool tty_termios_hw_change(const struct ktermios *a, const struct ktermios *b)
257{
258 if (a->c_ispeed != b->c_ispeed || a->c_ospeed != b->c_ospeed)
259 return true;
260 if ((a->c_cflag ^ b->c_cflag) & ~(HUPCL | CREAD | CLOCAL))
261 return true;
262 return false;
263}
264EXPORT_SYMBOL(tty_termios_hw_change);
265
266/**
267 * tty_get_char_size - get size of a character
268 * @cflag: termios cflag value
269 *
270 * Returns: size (in bits) of a character depending on @cflag's %CSIZE setting
271 */
272unsigned char tty_get_char_size(unsigned int cflag)
273{
274 switch (cflag & CSIZE) {
275 case CS5:
276 return 5;
277 case CS6:
278 return 6;
279 case CS7:
280 return 7;
281 case CS8:
282 default:
283 return 8;
284 }
285}
286EXPORT_SYMBOL_GPL(tty_get_char_size);
287
288/**
289 * tty_get_frame_size - get size of a frame
290 * @cflag: termios cflag value
291 *
292 * Get the size (in bits) of a frame depending on @cflag's %CSIZE, %CSTOPB, and
293 * %PARENB setting. The result is a sum of character size, start and stop bits
294 * -- one bit each -- second stop bit (if set), and parity bit (if set).
295 *
296 * Returns: size (in bits) of a frame depending on @cflag's setting.
297 */
298unsigned char tty_get_frame_size(unsigned int cflag)
299{
300 unsigned char bits = 2 + tty_get_char_size(cflag);
301
302 if (cflag & CSTOPB)
303 bits++;
304 if (cflag & PARENB)
305 bits++;
306 if (cflag & ADDRB)
307 bits++;
308
309 return bits;
310}
311EXPORT_SYMBOL_GPL(tty_get_frame_size);
312
313/**
314 * tty_set_termios - update termios values
315 * @tty: tty to update
316 * @new_termios: desired new value
317 *
318 * Perform updates to the termios values set on this @tty. A master pty's
319 * termios should never be set.
320 *
321 * Locking: &tty_struct->termios_rwsem
322 */
323int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios)
324{
325 struct ktermios old_termios;
326 struct tty_ldisc *ld;
327
328 WARN_ON(tty->driver->type == TTY_DRIVER_TYPE_PTY &&
329 tty->driver->subtype == PTY_TYPE_MASTER);
330 /*
331 * Perform the actual termios internal changes under lock.
332 */
333
334
335 /* FIXME: we need to decide on some locking/ordering semantics
336 for the set_termios notification eventually */
337 down_write(&tty->termios_rwsem);
338 old_termios = tty->termios;
339 tty->termios = *new_termios;
340 unset_locked_termios(tty, &old_termios);
341 /* Reset any ADDRB changes, ADDRB is changed through ->rs485_config() */
342 tty->termios.c_cflag ^= (tty->termios.c_cflag ^ old_termios.c_cflag) & ADDRB;
343
344 if (tty->ops->set_termios)
345 tty->ops->set_termios(tty, &old_termios);
346 else
347 tty_termios_copy_hw(&tty->termios, &old_termios);
348
349 ld = tty_ldisc_ref(tty);
350 if (ld != NULL) {
351 if (ld->ops->set_termios)
352 ld->ops->set_termios(tty, &old_termios);
353 tty_ldisc_deref(ld);
354 }
355 up_write(&tty->termios_rwsem);
356 return 0;
357}
358EXPORT_SYMBOL_GPL(tty_set_termios);
359
360
361/*
362 * Translate a "termio" structure into a "termios". Ugh.
363 */
364__weak int user_termio_to_kernel_termios(struct ktermios *termios,
365 struct termio __user *termio)
366{
367 struct termio v;
368
369 if (copy_from_user(&v, termio, sizeof(struct termio)))
370 return -EFAULT;
371
372 termios->c_iflag = (0xffff0000 & termios->c_iflag) | v.c_iflag;
373 termios->c_oflag = (0xffff0000 & termios->c_oflag) | v.c_oflag;
374 termios->c_cflag = (0xffff0000 & termios->c_cflag) | v.c_cflag;
375 termios->c_lflag = (0xffff0000 & termios->c_lflag) | v.c_lflag;
376 termios->c_line = (0xffff0000 & termios->c_lflag) | v.c_line;
377 memcpy(termios->c_cc, v.c_cc, NCC);
378 return 0;
379}
380
381/*
382 * Translate a "termios" structure into a "termio". Ugh.
383 */
384__weak int kernel_termios_to_user_termio(struct termio __user *termio,
385 struct ktermios *termios)
386{
387 struct termio v;
388 memset(&v, 0, sizeof(struct termio));
389 v.c_iflag = termios->c_iflag;
390 v.c_oflag = termios->c_oflag;
391 v.c_cflag = termios->c_cflag;
392 v.c_lflag = termios->c_lflag;
393 v.c_line = termios->c_line;
394 memcpy(v.c_cc, termios->c_cc, NCC);
395 return copy_to_user(termio, &v, sizeof(struct termio));
396}
397
398#ifdef TCGETS2
399__weak int user_termios_to_kernel_termios(struct ktermios *k,
400 struct termios2 __user *u)
401{
402 return copy_from_user(k, u, sizeof(struct termios2));
403}
404__weak int kernel_termios_to_user_termios(struct termios2 __user *u,
405 struct ktermios *k)
406{
407 return copy_to_user(u, k, sizeof(struct termios2));
408}
409__weak int user_termios_to_kernel_termios_1(struct ktermios *k,
410 struct termios __user *u)
411{
412 return copy_from_user(k, u, sizeof(struct termios));
413}
414__weak int kernel_termios_to_user_termios_1(struct termios __user *u,
415 struct ktermios *k)
416{
417 return copy_to_user(u, k, sizeof(struct termios));
418}
419
420#else
421
422__weak int user_termios_to_kernel_termios(struct ktermios *k,
423 struct termios __user *u)
424{
425 return copy_from_user(k, u, sizeof(struct termios));
426}
427__weak int kernel_termios_to_user_termios(struct termios __user *u,
428 struct ktermios *k)
429{
430 return copy_to_user(u, k, sizeof(struct termios));
431}
432#endif /* TCGETS2 */
433
434/**
435 * set_termios - set termios values for a tty
436 * @tty: terminal device
437 * @arg: user data
438 * @opt: option information
439 *
440 * Helper function to prepare termios data and run necessary other functions
441 * before using tty_set_termios() to do the actual changes.
442 *
443 * Locking: called functions take &tty_struct->ldisc_sem and
444 * &tty_struct->termios_rwsem locks
445 *
446 * Returns: 0 on success, an error otherwise
447 */
448static int set_termios(struct tty_struct *tty, void __user *arg, int opt)
449{
450 struct ktermios tmp_termios;
451 struct tty_ldisc *ld;
452 int retval = tty_check_change(tty);
453
454 if (retval)
455 return retval;
456
457 down_read(&tty->termios_rwsem);
458 tmp_termios = tty->termios;
459 up_read(&tty->termios_rwsem);
460
461 if (opt & TERMIOS_TERMIO) {
462 if (user_termio_to_kernel_termios(&tmp_termios,
463 (struct termio __user *)arg))
464 return -EFAULT;
465#ifdef TCGETS2
466 } else if (opt & TERMIOS_OLD) {
467 if (user_termios_to_kernel_termios_1(&tmp_termios,
468 (struct termios __user *)arg))
469 return -EFAULT;
470 } else {
471 if (user_termios_to_kernel_termios(&tmp_termios,
472 (struct termios2 __user *)arg))
473 return -EFAULT;
474 }
475#else
476 } else if (user_termios_to_kernel_termios(&tmp_termios,
477 (struct termios __user *)arg))
478 return -EFAULT;
479#endif
480
481 /* If old style Bfoo values are used then load c_ispeed/c_ospeed
482 * with the real speed so its unconditionally usable */
483 tmp_termios.c_ispeed = tty_termios_input_baud_rate(&tmp_termios);
484 tmp_termios.c_ospeed = tty_termios_baud_rate(&tmp_termios);
485
486 if (opt & (TERMIOS_FLUSH|TERMIOS_WAIT)) {
487retry_write_wait:
488 retval = wait_event_interruptible(tty->write_wait, !tty_chars_in_buffer(tty));
489 if (retval < 0)
490 return retval;
491
492 if (tty_write_lock(tty, false) < 0)
493 goto retry_write_wait;
494
495 /* Racing writer? */
496 if (tty_chars_in_buffer(tty)) {
497 tty_write_unlock(tty);
498 goto retry_write_wait;
499 }
500
501 ld = tty_ldisc_ref(tty);
502 if (ld != NULL) {
503 if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
504 ld->ops->flush_buffer(tty);
505 tty_ldisc_deref(ld);
506 }
507
508 if ((opt & TERMIOS_WAIT) && tty->ops->wait_until_sent) {
509 tty->ops->wait_until_sent(tty, 0);
510 if (signal_pending(current)) {
511 tty_write_unlock(tty);
512 return -ERESTARTSYS;
513 }
514 }
515
516 tty_set_termios(tty, &tmp_termios);
517
518 tty_write_unlock(tty);
519 } else {
520 tty_set_termios(tty, &tmp_termios);
521 }
522
523 /* FIXME: Arguably if tmp_termios == tty->termios AND the
524 actual requested termios was not tmp_termios then we may
525 want to return an error as no user requested change has
526 succeeded */
527 return 0;
528}
529
530static void copy_termios(struct tty_struct *tty, struct ktermios *kterm)
531{
532 down_read(&tty->termios_rwsem);
533 *kterm = tty->termios;
534 up_read(&tty->termios_rwsem);
535}
536
537static void copy_termios_locked(struct tty_struct *tty, struct ktermios *kterm)
538{
539 down_read(&tty->termios_rwsem);
540 *kterm = tty->termios_locked;
541 up_read(&tty->termios_rwsem);
542}
543
544static int get_termio(struct tty_struct *tty, struct termio __user *termio)
545{
546 struct ktermios kterm;
547 copy_termios(tty, &kterm);
548 if (kernel_termios_to_user_termio(termio, &kterm))
549 return -EFAULT;
550 return 0;
551}
552
553#ifdef TIOCGETP
554/*
555 * These are deprecated, but there is limited support..
556 *
557 * The "sg_flags" translation is a joke..
558 */
559static int get_sgflags(struct tty_struct *tty)
560{
561 int flags = 0;
562
563 if (!L_ICANON(tty)) {
564 if (L_ISIG(tty))
565 flags |= 0x02; /* cbreak */
566 else
567 flags |= 0x20; /* raw */
568 }
569 if (L_ECHO(tty))
570 flags |= 0x08; /* echo */
571 if (O_OPOST(tty))
572 if (O_ONLCR(tty))
573 flags |= 0x10; /* crmod */
574 return flags;
575}
576
577static int get_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
578{
579 struct sgttyb tmp;
580
581 down_read(&tty->termios_rwsem);
582 tmp.sg_ispeed = tty->termios.c_ispeed;
583 tmp.sg_ospeed = tty->termios.c_ospeed;
584 tmp.sg_erase = tty->termios.c_cc[VERASE];
585 tmp.sg_kill = tty->termios.c_cc[VKILL];
586 tmp.sg_flags = get_sgflags(tty);
587 up_read(&tty->termios_rwsem);
588
589 return copy_to_user(sgttyb, &tmp, sizeof(tmp)) ? -EFAULT : 0;
590}
591
592static void set_sgflags(struct ktermios *termios, int flags)
593{
594 termios->c_iflag = ICRNL | IXON;
595 termios->c_oflag = 0;
596 termios->c_lflag = ISIG | ICANON;
597 if (flags & 0x02) { /* cbreak */
598 termios->c_iflag = 0;
599 termios->c_lflag &= ~ICANON;
600 }
601 if (flags & 0x08) { /* echo */
602 termios->c_lflag |= ECHO | ECHOE | ECHOK |
603 ECHOCTL | ECHOKE | IEXTEN;
604 }
605 if (flags & 0x10) { /* crmod */
606 termios->c_oflag |= OPOST | ONLCR;
607 }
608 if (flags & 0x20) { /* raw */
609 termios->c_iflag = 0;
610 termios->c_lflag &= ~(ISIG | ICANON);
611 }
612 if (!(termios->c_lflag & ICANON)) {
613 termios->c_cc[VMIN] = 1;
614 termios->c_cc[VTIME] = 0;
615 }
616}
617
618/**
619 * set_sgttyb - set legacy terminal values
620 * @tty: tty structure
621 * @sgttyb: pointer to old style terminal structure
622 *
623 * Updates a terminal from the legacy BSD style terminal information structure.
624 *
625 * Locking: &tty_struct->termios_rwsem
626 *
627 * Returns: 0 on success, an error otherwise
628 */
629static int set_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
630{
631 int retval;
632 struct sgttyb tmp;
633 struct ktermios termios;
634
635 retval = tty_check_change(tty);
636 if (retval)
637 return retval;
638
639 if (copy_from_user(&tmp, sgttyb, sizeof(tmp)))
640 return -EFAULT;
641
642 down_write(&tty->termios_rwsem);
643 termios = tty->termios;
644 termios.c_cc[VERASE] = tmp.sg_erase;
645 termios.c_cc[VKILL] = tmp.sg_kill;
646 set_sgflags(&termios, tmp.sg_flags);
647 /* Try and encode into Bfoo format */
648 tty_termios_encode_baud_rate(&termios, termios.c_ispeed,
649 termios.c_ospeed);
650 up_write(&tty->termios_rwsem);
651 tty_set_termios(tty, &termios);
652 return 0;
653}
654#endif
655
656#ifdef TIOCGETC
657static int get_tchars(struct tty_struct *tty, struct tchars __user *tchars)
658{
659 struct tchars tmp;
660
661 down_read(&tty->termios_rwsem);
662 tmp.t_intrc = tty->termios.c_cc[VINTR];
663 tmp.t_quitc = tty->termios.c_cc[VQUIT];
664 tmp.t_startc = tty->termios.c_cc[VSTART];
665 tmp.t_stopc = tty->termios.c_cc[VSTOP];
666 tmp.t_eofc = tty->termios.c_cc[VEOF];
667 tmp.t_brkc = tty->termios.c_cc[VEOL2]; /* what is brkc anyway? */
668 up_read(&tty->termios_rwsem);
669 return copy_to_user(tchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
670}
671
672static int set_tchars(struct tty_struct *tty, struct tchars __user *tchars)
673{
674 struct tchars tmp;
675
676 if (copy_from_user(&tmp, tchars, sizeof(tmp)))
677 return -EFAULT;
678 down_write(&tty->termios_rwsem);
679 tty->termios.c_cc[VINTR] = tmp.t_intrc;
680 tty->termios.c_cc[VQUIT] = tmp.t_quitc;
681 tty->termios.c_cc[VSTART] = tmp.t_startc;
682 tty->termios.c_cc[VSTOP] = tmp.t_stopc;
683 tty->termios.c_cc[VEOF] = tmp.t_eofc;
684 tty->termios.c_cc[VEOL2] = tmp.t_brkc; /* what is brkc anyway? */
685 up_write(&tty->termios_rwsem);
686 return 0;
687}
688#endif
689
690#ifdef TIOCGLTC
691static int get_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
692{
693 struct ltchars tmp;
694
695 down_read(&tty->termios_rwsem);
696 tmp.t_suspc = tty->termios.c_cc[VSUSP];
697 /* what is dsuspc anyway? */
698 tmp.t_dsuspc = tty->termios.c_cc[VSUSP];
699 tmp.t_rprntc = tty->termios.c_cc[VREPRINT];
700 /* what is flushc anyway? */
701 tmp.t_flushc = tty->termios.c_cc[VEOL2];
702 tmp.t_werasc = tty->termios.c_cc[VWERASE];
703 tmp.t_lnextc = tty->termios.c_cc[VLNEXT];
704 up_read(&tty->termios_rwsem);
705 return copy_to_user(ltchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
706}
707
708static int set_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
709{
710 struct ltchars tmp;
711
712 if (copy_from_user(&tmp, ltchars, sizeof(tmp)))
713 return -EFAULT;
714
715 down_write(&tty->termios_rwsem);
716 tty->termios.c_cc[VSUSP] = tmp.t_suspc;
717 /* what is dsuspc anyway? */
718 tty->termios.c_cc[VEOL2] = tmp.t_dsuspc;
719 tty->termios.c_cc[VREPRINT] = tmp.t_rprntc;
720 /* what is flushc anyway? */
721 tty->termios.c_cc[VEOL2] = tmp.t_flushc;
722 tty->termios.c_cc[VWERASE] = tmp.t_werasc;
723 tty->termios.c_cc[VLNEXT] = tmp.t_lnextc;
724 up_write(&tty->termios_rwsem);
725 return 0;
726}
727#endif
728
729/**
730 * tty_change_softcar - carrier change ioctl helper
731 * @tty: tty to update
732 * @enable: enable/disable %CLOCAL
733 *
734 * Perform a change to the %CLOCAL state and call into the driver layer to make
735 * it visible.
736 *
737 * Locking: &tty_struct->termios_rwsem.
738 *
739 * Returns: 0 on success, an error otherwise
740 */
741static int tty_change_softcar(struct tty_struct *tty, bool enable)
742{
743 int ret = 0;
744 struct ktermios old;
745 tcflag_t bit = enable ? CLOCAL : 0;
746
747 down_write(&tty->termios_rwsem);
748 old = tty->termios;
749 tty->termios.c_cflag &= ~CLOCAL;
750 tty->termios.c_cflag |= bit;
751 if (tty->ops->set_termios)
752 tty->ops->set_termios(tty, &old);
753 if (C_CLOCAL(tty) != bit)
754 ret = -EINVAL;
755 up_write(&tty->termios_rwsem);
756 return ret;
757}
758
759/**
760 * tty_mode_ioctl - mode related ioctls
761 * @tty: tty for the ioctl
762 * @cmd: command
763 * @arg: ioctl argument
764 *
765 * Perform non-line discipline specific mode control ioctls. This is designed
766 * to be called by line disciplines to ensure they provide consistent mode
767 * setting.
768 */
769int tty_mode_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
770{
771 struct tty_struct *real_tty;
772 void __user *p = (void __user *)arg;
773 int ret = 0;
774 struct ktermios kterm;
775
776 if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
777 tty->driver->subtype == PTY_TYPE_MASTER)
778 real_tty = tty->link;
779 else
780 real_tty = tty;
781
782 switch (cmd) {
783#ifdef TIOCGETP
784 case TIOCGETP:
785 return get_sgttyb(real_tty, (struct sgttyb __user *) arg);
786 case TIOCSETP:
787 case TIOCSETN:
788 return set_sgttyb(real_tty, (struct sgttyb __user *) arg);
789#endif
790#ifdef TIOCGETC
791 case TIOCGETC:
792 return get_tchars(real_tty, p);
793 case TIOCSETC:
794 return set_tchars(real_tty, p);
795#endif
796#ifdef TIOCGLTC
797 case TIOCGLTC:
798 return get_ltchars(real_tty, p);
799 case TIOCSLTC:
800 return set_ltchars(real_tty, p);
801#endif
802 case TCSETSF:
803 return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_OLD);
804 case TCSETSW:
805 return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_OLD);
806 case TCSETS:
807 return set_termios(real_tty, p, TERMIOS_OLD);
808#ifndef TCGETS2
809 case TCGETS:
810 copy_termios(real_tty, &kterm);
811 if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
812 ret = -EFAULT;
813 return ret;
814#else
815 case TCGETS:
816 copy_termios(real_tty, &kterm);
817 if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
818 ret = -EFAULT;
819 return ret;
820 case TCGETS2:
821 copy_termios(real_tty, &kterm);
822 if (kernel_termios_to_user_termios((struct termios2 __user *)arg, &kterm))
823 ret = -EFAULT;
824 return ret;
825 case TCSETSF2:
826 return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT);
827 case TCSETSW2:
828 return set_termios(real_tty, p, TERMIOS_WAIT);
829 case TCSETS2:
830 return set_termios(real_tty, p, 0);
831#endif
832 case TCGETA:
833 return get_termio(real_tty, p);
834 case TCSETAF:
835 return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_TERMIO);
836 case TCSETAW:
837 return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_TERMIO);
838 case TCSETA:
839 return set_termios(real_tty, p, TERMIOS_TERMIO);
840#ifndef TCGETS2
841 case TIOCGLCKTRMIOS:
842 copy_termios_locked(real_tty, &kterm);
843 if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
844 ret = -EFAULT;
845 return ret;
846 case TIOCSLCKTRMIOS:
847 if (!checkpoint_restore_ns_capable(&init_user_ns))
848 return -EPERM;
849 copy_termios_locked(real_tty, &kterm);
850 if (user_termios_to_kernel_termios(&kterm,
851 (struct termios __user *) arg))
852 return -EFAULT;
853 down_write(&real_tty->termios_rwsem);
854 real_tty->termios_locked = kterm;
855 up_write(&real_tty->termios_rwsem);
856 return 0;
857#else
858 case TIOCGLCKTRMIOS:
859 copy_termios_locked(real_tty, &kterm);
860 if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
861 ret = -EFAULT;
862 return ret;
863 case TIOCSLCKTRMIOS:
864 if (!checkpoint_restore_ns_capable(&init_user_ns))
865 return -EPERM;
866 copy_termios_locked(real_tty, &kterm);
867 if (user_termios_to_kernel_termios_1(&kterm,
868 (struct termios __user *) arg))
869 return -EFAULT;
870 down_write(&real_tty->termios_rwsem);
871 real_tty->termios_locked = kterm;
872 up_write(&real_tty->termios_rwsem);
873 return ret;
874#endif
875#ifdef TCGETX
876 case TCGETX:
877 case TCSETX:
878 case TCSETXW:
879 case TCSETXF:
880 return -ENOTTY;
881#endif
882 case TIOCGSOFTCAR:
883 copy_termios(real_tty, &kterm);
884 ret = put_user((kterm.c_cflag & CLOCAL) ? 1 : 0,
885 (int __user *)arg);
886 return ret;
887 case TIOCSSOFTCAR:
888 if (get_user(arg, (unsigned int __user *) arg))
889 return -EFAULT;
890 return tty_change_softcar(real_tty, arg);
891 default:
892 return -ENOIOCTLCMD;
893 }
894}
895EXPORT_SYMBOL_GPL(tty_mode_ioctl);
896
897
898/* Caller guarantees ldisc reference is held */
899static int __tty_perform_flush(struct tty_struct *tty, unsigned long arg)
900{
901 struct tty_ldisc *ld = tty->ldisc;
902
903 switch (arg) {
904 case TCIFLUSH:
905 if (ld && ld->ops->flush_buffer) {
906 ld->ops->flush_buffer(tty);
907 tty_unthrottle(tty);
908 }
909 break;
910 case TCIOFLUSH:
911 if (ld && ld->ops->flush_buffer) {
912 ld->ops->flush_buffer(tty);
913 tty_unthrottle(tty);
914 }
915 fallthrough;
916 case TCOFLUSH:
917 tty_driver_flush_buffer(tty);
918 break;
919 default:
920 return -EINVAL;
921 }
922 return 0;
923}
924
925int tty_perform_flush(struct tty_struct *tty, unsigned long arg)
926{
927 struct tty_ldisc *ld;
928 int retval = tty_check_change(tty);
929 if (retval)
930 return retval;
931
932 ld = tty_ldisc_ref_wait(tty);
933 retval = __tty_perform_flush(tty, arg);
934 if (ld)
935 tty_ldisc_deref(ld);
936 return retval;
937}
938EXPORT_SYMBOL_GPL(tty_perform_flush);
939
940int n_tty_ioctl_helper(struct tty_struct *tty, unsigned int cmd,
941 unsigned long arg)
942{
943 int retval;
944
945 switch (cmd) {
946 case TCXONC:
947 retval = tty_check_change(tty);
948 if (retval)
949 return retval;
950 switch (arg) {
951 case TCOOFF:
952 spin_lock_irq(&tty->flow.lock);
953 if (!tty->flow.tco_stopped) {
954 tty->flow.tco_stopped = true;
955 __stop_tty(tty);
956 }
957 spin_unlock_irq(&tty->flow.lock);
958 break;
959 case TCOON:
960 spin_lock_irq(&tty->flow.lock);
961 if (tty->flow.tco_stopped) {
962 tty->flow.tco_stopped = false;
963 __start_tty(tty);
964 }
965 spin_unlock_irq(&tty->flow.lock);
966 break;
967 case TCIOFF:
968 if (STOP_CHAR(tty) != __DISABLED_CHAR)
969 retval = tty_send_xchar(tty, STOP_CHAR(tty));
970 break;
971 case TCION:
972 if (START_CHAR(tty) != __DISABLED_CHAR)
973 retval = tty_send_xchar(tty, START_CHAR(tty));
974 break;
975 default:
976 return -EINVAL;
977 }
978 return retval;
979 case TCFLSH:
980 retval = tty_check_change(tty);
981 if (retval)
982 return retval;
983 return __tty_perform_flush(tty, arg);
984 default:
985 /* Try the mode commands */
986 return tty_mode_ioctl(tty, cmd, arg);
987 }
988}
989EXPORT_SYMBOL(n_tty_ioctl_helper);
1/*
2 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
3 *
4 * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
5 * which can be dynamically activated and de-activated by the line
6 * discipline handling modules (like SLIP).
7 */
8
9#include <linux/types.h>
10#include <linux/termios.h>
11#include <linux/errno.h>
12#include <linux/sched.h>
13#include <linux/kernel.h>
14#include <linux/major.h>
15#include <linux/tty.h>
16#include <linux/fcntl.h>
17#include <linux/string.h>
18#include <linux/mm.h>
19#include <linux/module.h>
20#include <linux/bitops.h>
21#include <linux/mutex.h>
22
23#include <asm/io.h>
24#include <asm/uaccess.h>
25#include <asm/system.h>
26
27#undef TTY_DEBUG_WAIT_UNTIL_SENT
28
29#undef DEBUG
30
31/*
32 * Internal flag options for termios setting behavior
33 */
34#define TERMIOS_FLUSH 1
35#define TERMIOS_WAIT 2
36#define TERMIOS_TERMIO 4
37#define TERMIOS_OLD 8
38
39
40/**
41 * tty_chars_in_buffer - characters pending
42 * @tty: terminal
43 *
44 * Return the number of bytes of data in the device private
45 * output queue. If no private method is supplied there is assumed
46 * to be no queue on the device.
47 */
48
49int tty_chars_in_buffer(struct tty_struct *tty)
50{
51 if (tty->ops->chars_in_buffer)
52 return tty->ops->chars_in_buffer(tty);
53 else
54 return 0;
55}
56EXPORT_SYMBOL(tty_chars_in_buffer);
57
58/**
59 * tty_write_room - write queue space
60 * @tty: terminal
61 *
62 * Return the number of bytes that can be queued to this device
63 * at the present time. The result should be treated as a guarantee
64 * and the driver cannot offer a value it later shrinks by more than
65 * the number of bytes written. If no method is provided 2K is always
66 * returned and data may be lost as there will be no flow control.
67 */
68
69int tty_write_room(struct tty_struct *tty)
70{
71 if (tty->ops->write_room)
72 return tty->ops->write_room(tty);
73 return 2048;
74}
75EXPORT_SYMBOL(tty_write_room);
76
77/**
78 * tty_driver_flush_buffer - discard internal buffer
79 * @tty: terminal
80 *
81 * Discard the internal output buffer for this device. If no method
82 * is provided then either the buffer cannot be hardware flushed or
83 * there is no buffer driver side.
84 */
85void tty_driver_flush_buffer(struct tty_struct *tty)
86{
87 if (tty->ops->flush_buffer)
88 tty->ops->flush_buffer(tty);
89}
90EXPORT_SYMBOL(tty_driver_flush_buffer);
91
92/**
93 * tty_throttle - flow control
94 * @tty: terminal
95 *
96 * Indicate that a tty should stop transmitting data down the stack.
97 * Takes the termios mutex to protect against parallel throttle/unthrottle
98 * and also to ensure the driver can consistently reference its own
99 * termios data at this point when implementing software flow control.
100 */
101
102void tty_throttle(struct tty_struct *tty)
103{
104 mutex_lock(&tty->termios_mutex);
105 /* check TTY_THROTTLED first so it indicates our state */
106 if (!test_and_set_bit(TTY_THROTTLED, &tty->flags) &&
107 tty->ops->throttle)
108 tty->ops->throttle(tty);
109 mutex_unlock(&tty->termios_mutex);
110}
111EXPORT_SYMBOL(tty_throttle);
112
113/**
114 * tty_unthrottle - flow control
115 * @tty: terminal
116 *
117 * Indicate that a tty may continue transmitting data down the stack.
118 * Takes the termios mutex to protect against parallel throttle/unthrottle
119 * and also to ensure the driver can consistently reference its own
120 * termios data at this point when implementing software flow control.
121 *
122 * Drivers should however remember that the stack can issue a throttle,
123 * then change flow control method, then unthrottle.
124 */
125
126void tty_unthrottle(struct tty_struct *tty)
127{
128 mutex_lock(&tty->termios_mutex);
129 if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) &&
130 tty->ops->unthrottle)
131 tty->ops->unthrottle(tty);
132 mutex_unlock(&tty->termios_mutex);
133}
134EXPORT_SYMBOL(tty_unthrottle);
135
136/**
137 * tty_wait_until_sent - wait for I/O to finish
138 * @tty: tty we are waiting for
139 * @timeout: how long we will wait
140 *
141 * Wait for characters pending in a tty driver to hit the wire, or
142 * for a timeout to occur (eg due to flow control)
143 *
144 * Locking: none
145 */
146
147void tty_wait_until_sent(struct tty_struct *tty, long timeout)
148{
149#ifdef TTY_DEBUG_WAIT_UNTIL_SENT
150 char buf[64];
151
152 printk(KERN_DEBUG "%s wait until sent...\n", tty_name(tty, buf));
153#endif
154 if (!timeout)
155 timeout = MAX_SCHEDULE_TIMEOUT;
156 if (wait_event_interruptible_timeout(tty->write_wait,
157 !tty_chars_in_buffer(tty), timeout) >= 0) {
158 if (tty->ops->wait_until_sent)
159 tty->ops->wait_until_sent(tty, timeout);
160 }
161}
162EXPORT_SYMBOL(tty_wait_until_sent);
163
164
165/*
166 * Termios Helper Methods
167 */
168
169static void unset_locked_termios(struct ktermios *termios,
170 struct ktermios *old,
171 struct ktermios *locked)
172{
173 int i;
174
175#define NOSET_MASK(x, y, z) (x = ((x) & ~(z)) | ((y) & (z)))
176
177 if (!locked) {
178 printk(KERN_WARNING "Warning?!? termios_locked is NULL.\n");
179 return;
180 }
181
182 NOSET_MASK(termios->c_iflag, old->c_iflag, locked->c_iflag);
183 NOSET_MASK(termios->c_oflag, old->c_oflag, locked->c_oflag);
184 NOSET_MASK(termios->c_cflag, old->c_cflag, locked->c_cflag);
185 NOSET_MASK(termios->c_lflag, old->c_lflag, locked->c_lflag);
186 termios->c_line = locked->c_line ? old->c_line : termios->c_line;
187 for (i = 0; i < NCCS; i++)
188 termios->c_cc[i] = locked->c_cc[i] ?
189 old->c_cc[i] : termios->c_cc[i];
190 /* FIXME: What should we do for i/ospeed */
191}
192
193/*
194 * Routine which returns the baud rate of the tty
195 *
196 * Note that the baud_table needs to be kept in sync with the
197 * include/asm/termbits.h file.
198 */
199static const speed_t baud_table[] = {
200 0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
201 9600, 19200, 38400, 57600, 115200, 230400, 460800,
202#ifdef __sparc__
203 76800, 153600, 307200, 614400, 921600
204#else
205 500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000,
206 2500000, 3000000, 3500000, 4000000
207#endif
208};
209
210#ifndef __sparc__
211static const tcflag_t baud_bits[] = {
212 B0, B50, B75, B110, B134, B150, B200, B300, B600,
213 B1200, B1800, B2400, B4800, B9600, B19200, B38400,
214 B57600, B115200, B230400, B460800, B500000, B576000,
215 B921600, B1000000, B1152000, B1500000, B2000000, B2500000,
216 B3000000, B3500000, B4000000
217};
218#else
219static const tcflag_t baud_bits[] = {
220 B0, B50, B75, B110, B134, B150, B200, B300, B600,
221 B1200, B1800, B2400, B4800, B9600, B19200, B38400,
222 B57600, B115200, B230400, B460800, B76800, B153600,
223 B307200, B614400, B921600
224};
225#endif
226
227static int n_baud_table = ARRAY_SIZE(baud_table);
228
229/**
230 * tty_termios_baud_rate
231 * @termios: termios structure
232 *
233 * Convert termios baud rate data into a speed. This should be called
234 * with the termios lock held if this termios is a terminal termios
235 * structure. May change the termios data. Device drivers can call this
236 * function but should use ->c_[io]speed directly as they are updated.
237 *
238 * Locking: none
239 */
240
241speed_t tty_termios_baud_rate(struct ktermios *termios)
242{
243 unsigned int cbaud;
244
245 cbaud = termios->c_cflag & CBAUD;
246
247#ifdef BOTHER
248 /* Magic token for arbitrary speed via c_ispeed/c_ospeed */
249 if (cbaud == BOTHER)
250 return termios->c_ospeed;
251#endif
252 if (cbaud & CBAUDEX) {
253 cbaud &= ~CBAUDEX;
254
255 if (cbaud < 1 || cbaud + 15 > n_baud_table)
256 termios->c_cflag &= ~CBAUDEX;
257 else
258 cbaud += 15;
259 }
260 return baud_table[cbaud];
261}
262EXPORT_SYMBOL(tty_termios_baud_rate);
263
264/**
265 * tty_termios_input_baud_rate
266 * @termios: termios structure
267 *
268 * Convert termios baud rate data into a speed. This should be called
269 * with the termios lock held if this termios is a terminal termios
270 * structure. May change the termios data. Device drivers can call this
271 * function but should use ->c_[io]speed directly as they are updated.
272 *
273 * Locking: none
274 */
275
276speed_t tty_termios_input_baud_rate(struct ktermios *termios)
277{
278#ifdef IBSHIFT
279 unsigned int cbaud = (termios->c_cflag >> IBSHIFT) & CBAUD;
280
281 if (cbaud == B0)
282 return tty_termios_baud_rate(termios);
283
284 /* Magic token for arbitrary speed via c_ispeed*/
285 if (cbaud == BOTHER)
286 return termios->c_ispeed;
287
288 if (cbaud & CBAUDEX) {
289 cbaud &= ~CBAUDEX;
290
291 if (cbaud < 1 || cbaud + 15 > n_baud_table)
292 termios->c_cflag &= ~(CBAUDEX << IBSHIFT);
293 else
294 cbaud += 15;
295 }
296 return baud_table[cbaud];
297#else
298 return tty_termios_baud_rate(termios);
299#endif
300}
301EXPORT_SYMBOL(tty_termios_input_baud_rate);
302
303/**
304 * tty_termios_encode_baud_rate
305 * @termios: ktermios structure holding user requested state
306 * @ispeed: input speed
307 * @ospeed: output speed
308 *
309 * Encode the speeds set into the passed termios structure. This is
310 * used as a library helper for drivers so that they can report back
311 * the actual speed selected when it differs from the speed requested
312 *
313 * For maximal back compatibility with legacy SYS5/POSIX *nix behaviour
314 * we need to carefully set the bits when the user does not get the
315 * desired speed. We allow small margins and preserve as much of possible
316 * of the input intent to keep compatibility.
317 *
318 * Locking: Caller should hold termios lock. This is already held
319 * when calling this function from the driver termios handler.
320 *
321 * The ifdefs deal with platforms whose owners have yet to update them
322 * and will all go away once this is done.
323 */
324
325void tty_termios_encode_baud_rate(struct ktermios *termios,
326 speed_t ibaud, speed_t obaud)
327{
328 int i = 0;
329 int ifound = -1, ofound = -1;
330 int iclose = ibaud/50, oclose = obaud/50;
331 int ibinput = 0;
332
333 if (obaud == 0) /* CD dropped */
334 ibaud = 0; /* Clear ibaud to be sure */
335
336 termios->c_ispeed = ibaud;
337 termios->c_ospeed = obaud;
338
339#ifdef BOTHER
340 /* If the user asked for a precise weird speed give a precise weird
341 answer. If they asked for a Bfoo speed they many have problems
342 digesting non-exact replies so fuzz a bit */
343
344 if ((termios->c_cflag & CBAUD) == BOTHER)
345 oclose = 0;
346 if (((termios->c_cflag >> IBSHIFT) & CBAUD) == BOTHER)
347 iclose = 0;
348 if ((termios->c_cflag >> IBSHIFT) & CBAUD)
349 ibinput = 1; /* An input speed was specified */
350#endif
351 termios->c_cflag &= ~CBAUD;
352
353 /*
354 * Our goal is to find a close match to the standard baud rate
355 * returned. Walk the baud rate table and if we get a very close
356 * match then report back the speed as a POSIX Bxxxx value by
357 * preference
358 */
359
360 do {
361 if (obaud - oclose <= baud_table[i] &&
362 obaud + oclose >= baud_table[i]) {
363 termios->c_cflag |= baud_bits[i];
364 ofound = i;
365 }
366 if (ibaud - iclose <= baud_table[i] &&
367 ibaud + iclose >= baud_table[i]) {
368 /* For the case input == output don't set IBAUD bits
369 if the user didn't do so */
370 if (ofound == i && !ibinput)
371 ifound = i;
372#ifdef IBSHIFT
373 else {
374 ifound = i;
375 termios->c_cflag |= (baud_bits[i] << IBSHIFT);
376 }
377#endif
378 }
379 } while (++i < n_baud_table);
380
381 /*
382 * If we found no match then use BOTHER if provided or warn
383 * the user their platform maintainer needs to wake up if not.
384 */
385#ifdef BOTHER
386 if (ofound == -1)
387 termios->c_cflag |= BOTHER;
388 /* Set exact input bits only if the input and output differ or the
389 user already did */
390 if (ifound == -1 && (ibaud != obaud || ibinput))
391 termios->c_cflag |= (BOTHER << IBSHIFT);
392#else
393 if (ifound == -1 || ofound == -1) {
394 printk_once(KERN_WARNING "tty: Unable to return correct "
395 "speed data as your architecture needs updating.\n");
396 }
397#endif
398}
399EXPORT_SYMBOL_GPL(tty_termios_encode_baud_rate);
400
401/**
402 * tty_encode_baud_rate - set baud rate of the tty
403 * @ibaud: input baud rate
404 * @obad: output baud rate
405 *
406 * Update the current termios data for the tty with the new speed
407 * settings. The caller must hold the termios_mutex for the tty in
408 * question.
409 */
410
411void tty_encode_baud_rate(struct tty_struct *tty, speed_t ibaud, speed_t obaud)
412{
413 tty_termios_encode_baud_rate(tty->termios, ibaud, obaud);
414}
415EXPORT_SYMBOL_GPL(tty_encode_baud_rate);
416
417/**
418 * tty_get_baud_rate - get tty bit rates
419 * @tty: tty to query
420 *
421 * Returns the baud rate as an integer for this terminal. The
422 * termios lock must be held by the caller and the terminal bit
423 * flags may be updated.
424 *
425 * Locking: none
426 */
427
428speed_t tty_get_baud_rate(struct tty_struct *tty)
429{
430 speed_t baud = tty_termios_baud_rate(tty->termios);
431
432 if (baud == 38400 && tty->alt_speed) {
433 if (!tty->warned) {
434 printk(KERN_WARNING "Use of setserial/setrocket to "
435 "set SPD_* flags is deprecated\n");
436 tty->warned = 1;
437 }
438 baud = tty->alt_speed;
439 }
440
441 return baud;
442}
443EXPORT_SYMBOL(tty_get_baud_rate);
444
445/**
446 * tty_termios_copy_hw - copy hardware settings
447 * @new: New termios
448 * @old: Old termios
449 *
450 * Propagate the hardware specific terminal setting bits from
451 * the old termios structure to the new one. This is used in cases
452 * where the hardware does not support reconfiguration or as a helper
453 * in some cases where only minimal reconfiguration is supported
454 */
455
456void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old)
457{
458 /* The bits a dumb device handles in software. Smart devices need
459 to always provide a set_termios method */
460 new->c_cflag &= HUPCL | CREAD | CLOCAL;
461 new->c_cflag |= old->c_cflag & ~(HUPCL | CREAD | CLOCAL);
462 new->c_ispeed = old->c_ispeed;
463 new->c_ospeed = old->c_ospeed;
464}
465EXPORT_SYMBOL(tty_termios_copy_hw);
466
467/**
468 * tty_termios_hw_change - check for setting change
469 * @a: termios
470 * @b: termios to compare
471 *
472 * Check if any of the bits that affect a dumb device have changed
473 * between the two termios structures, or a speed change is needed.
474 */
475
476int tty_termios_hw_change(struct ktermios *a, struct ktermios *b)
477{
478 if (a->c_ispeed != b->c_ispeed || a->c_ospeed != b->c_ospeed)
479 return 1;
480 if ((a->c_cflag ^ b->c_cflag) & ~(HUPCL | CREAD | CLOCAL))
481 return 1;
482 return 0;
483}
484EXPORT_SYMBOL(tty_termios_hw_change);
485
486/**
487 * tty_set_termios - update termios values
488 * @tty: tty to update
489 * @new_termios: desired new value
490 *
491 * Perform updates to the termios values set on this terminal. There
492 * is a bit of layering violation here with n_tty in terms of the
493 * internal knowledge of this function.
494 *
495 * Locking: termios_mutex
496 */
497
498int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios)
499{
500 struct ktermios old_termios;
501 struct tty_ldisc *ld;
502 unsigned long flags;
503
504 /*
505 * Perform the actual termios internal changes under lock.
506 */
507
508
509 /* FIXME: we need to decide on some locking/ordering semantics
510 for the set_termios notification eventually */
511 mutex_lock(&tty->termios_mutex);
512 old_termios = *tty->termios;
513 *tty->termios = *new_termios;
514 unset_locked_termios(tty->termios, &old_termios, tty->termios_locked);
515
516 /* See if packet mode change of state. */
517 if (tty->link && tty->link->packet) {
518 int extproc = (old_termios.c_lflag & EXTPROC) |
519 (tty->termios->c_lflag & EXTPROC);
520 int old_flow = ((old_termios.c_iflag & IXON) &&
521 (old_termios.c_cc[VSTOP] == '\023') &&
522 (old_termios.c_cc[VSTART] == '\021'));
523 int new_flow = (I_IXON(tty) &&
524 STOP_CHAR(tty) == '\023' &&
525 START_CHAR(tty) == '\021');
526 if ((old_flow != new_flow) || extproc) {
527 spin_lock_irqsave(&tty->ctrl_lock, flags);
528 if (old_flow != new_flow) {
529 tty->ctrl_status &= ~(TIOCPKT_DOSTOP | TIOCPKT_NOSTOP);
530 if (new_flow)
531 tty->ctrl_status |= TIOCPKT_DOSTOP;
532 else
533 tty->ctrl_status |= TIOCPKT_NOSTOP;
534 }
535 if (extproc)
536 tty->ctrl_status |= TIOCPKT_IOCTL;
537 spin_unlock_irqrestore(&tty->ctrl_lock, flags);
538 wake_up_interruptible(&tty->link->read_wait);
539 }
540 }
541
542 if (tty->ops->set_termios)
543 (*tty->ops->set_termios)(tty, &old_termios);
544 else
545 tty_termios_copy_hw(tty->termios, &old_termios);
546
547 ld = tty_ldisc_ref(tty);
548 if (ld != NULL) {
549 if (ld->ops->set_termios)
550 (ld->ops->set_termios)(tty, &old_termios);
551 tty_ldisc_deref(ld);
552 }
553 mutex_unlock(&tty->termios_mutex);
554 return 0;
555}
556EXPORT_SYMBOL_GPL(tty_set_termios);
557
558/**
559 * set_termios - set termios values for a tty
560 * @tty: terminal device
561 * @arg: user data
562 * @opt: option information
563 *
564 * Helper function to prepare termios data and run necessary other
565 * functions before using tty_set_termios to do the actual changes.
566 *
567 * Locking:
568 * Called functions take ldisc and termios_mutex locks
569 */
570
571static int set_termios(struct tty_struct *tty, void __user *arg, int opt)
572{
573 struct ktermios tmp_termios;
574 struct tty_ldisc *ld;
575 int retval = tty_check_change(tty);
576
577 if (retval)
578 return retval;
579
580 mutex_lock(&tty->termios_mutex);
581 memcpy(&tmp_termios, tty->termios, sizeof(struct ktermios));
582 mutex_unlock(&tty->termios_mutex);
583
584 if (opt & TERMIOS_TERMIO) {
585 if (user_termio_to_kernel_termios(&tmp_termios,
586 (struct termio __user *)arg))
587 return -EFAULT;
588#ifdef TCGETS2
589 } else if (opt & TERMIOS_OLD) {
590 if (user_termios_to_kernel_termios_1(&tmp_termios,
591 (struct termios __user *)arg))
592 return -EFAULT;
593 } else {
594 if (user_termios_to_kernel_termios(&tmp_termios,
595 (struct termios2 __user *)arg))
596 return -EFAULT;
597 }
598#else
599 } else if (user_termios_to_kernel_termios(&tmp_termios,
600 (struct termios __user *)arg))
601 return -EFAULT;
602#endif
603
604 /* If old style Bfoo values are used then load c_ispeed/c_ospeed
605 * with the real speed so its unconditionally usable */
606 tmp_termios.c_ispeed = tty_termios_input_baud_rate(&tmp_termios);
607 tmp_termios.c_ospeed = tty_termios_baud_rate(&tmp_termios);
608
609 ld = tty_ldisc_ref(tty);
610
611 if (ld != NULL) {
612 if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
613 ld->ops->flush_buffer(tty);
614 tty_ldisc_deref(ld);
615 }
616
617 if (opt & TERMIOS_WAIT) {
618 tty_wait_until_sent(tty, 0);
619 if (signal_pending(current))
620 return -EINTR;
621 }
622
623 tty_set_termios(tty, &tmp_termios);
624
625 /* FIXME: Arguably if tmp_termios == tty->termios AND the
626 actual requested termios was not tmp_termios then we may
627 want to return an error as no user requested change has
628 succeeded */
629 return 0;
630}
631
632static void copy_termios(struct tty_struct *tty, struct ktermios *kterm)
633{
634 mutex_lock(&tty->termios_mutex);
635 memcpy(kterm, tty->termios, sizeof(struct ktermios));
636 mutex_unlock(&tty->termios_mutex);
637}
638
639static void copy_termios_locked(struct tty_struct *tty, struct ktermios *kterm)
640{
641 mutex_lock(&tty->termios_mutex);
642 memcpy(kterm, tty->termios_locked, sizeof(struct ktermios));
643 mutex_unlock(&tty->termios_mutex);
644}
645
646static int get_termio(struct tty_struct *tty, struct termio __user *termio)
647{
648 struct ktermios kterm;
649 copy_termios(tty, &kterm);
650 if (kernel_termios_to_user_termio(termio, &kterm))
651 return -EFAULT;
652 return 0;
653}
654
655
656#ifdef TCGETX
657
658/**
659 * set_termiox - set termiox fields if possible
660 * @tty: terminal
661 * @arg: termiox structure from user
662 * @opt: option flags for ioctl type
663 *
664 * Implement the device calling points for the SYS5 termiox ioctl
665 * interface in Linux
666 */
667
668static int set_termiox(struct tty_struct *tty, void __user *arg, int opt)
669{
670 struct termiox tnew;
671 struct tty_ldisc *ld;
672
673 if (tty->termiox == NULL)
674 return -EINVAL;
675 if (copy_from_user(&tnew, arg, sizeof(struct termiox)))
676 return -EFAULT;
677
678 ld = tty_ldisc_ref(tty);
679 if (ld != NULL) {
680 if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
681 ld->ops->flush_buffer(tty);
682 tty_ldisc_deref(ld);
683 }
684 if (opt & TERMIOS_WAIT) {
685 tty_wait_until_sent(tty, 0);
686 if (signal_pending(current))
687 return -EINTR;
688 }
689
690 mutex_lock(&tty->termios_mutex);
691 if (tty->ops->set_termiox)
692 tty->ops->set_termiox(tty, &tnew);
693 mutex_unlock(&tty->termios_mutex);
694 return 0;
695}
696
697#endif
698
699
700#ifdef TIOCGETP
701/*
702 * These are deprecated, but there is limited support..
703 *
704 * The "sg_flags" translation is a joke..
705 */
706static int get_sgflags(struct tty_struct *tty)
707{
708 int flags = 0;
709
710 if (!(tty->termios->c_lflag & ICANON)) {
711 if (tty->termios->c_lflag & ISIG)
712 flags |= 0x02; /* cbreak */
713 else
714 flags |= 0x20; /* raw */
715 }
716 if (tty->termios->c_lflag & ECHO)
717 flags |= 0x08; /* echo */
718 if (tty->termios->c_oflag & OPOST)
719 if (tty->termios->c_oflag & ONLCR)
720 flags |= 0x10; /* crmod */
721 return flags;
722}
723
724static int get_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
725{
726 struct sgttyb tmp;
727
728 mutex_lock(&tty->termios_mutex);
729 tmp.sg_ispeed = tty->termios->c_ispeed;
730 tmp.sg_ospeed = tty->termios->c_ospeed;
731 tmp.sg_erase = tty->termios->c_cc[VERASE];
732 tmp.sg_kill = tty->termios->c_cc[VKILL];
733 tmp.sg_flags = get_sgflags(tty);
734 mutex_unlock(&tty->termios_mutex);
735
736 return copy_to_user(sgttyb, &tmp, sizeof(tmp)) ? -EFAULT : 0;
737}
738
739static void set_sgflags(struct ktermios *termios, int flags)
740{
741 termios->c_iflag = ICRNL | IXON;
742 termios->c_oflag = 0;
743 termios->c_lflag = ISIG | ICANON;
744 if (flags & 0x02) { /* cbreak */
745 termios->c_iflag = 0;
746 termios->c_lflag &= ~ICANON;
747 }
748 if (flags & 0x08) { /* echo */
749 termios->c_lflag |= ECHO | ECHOE | ECHOK |
750 ECHOCTL | ECHOKE | IEXTEN;
751 }
752 if (flags & 0x10) { /* crmod */
753 termios->c_oflag |= OPOST | ONLCR;
754 }
755 if (flags & 0x20) { /* raw */
756 termios->c_iflag = 0;
757 termios->c_lflag &= ~(ISIG | ICANON);
758 }
759 if (!(termios->c_lflag & ICANON)) {
760 termios->c_cc[VMIN] = 1;
761 termios->c_cc[VTIME] = 0;
762 }
763}
764
765/**
766 * set_sgttyb - set legacy terminal values
767 * @tty: tty structure
768 * @sgttyb: pointer to old style terminal structure
769 *
770 * Updates a terminal from the legacy BSD style terminal information
771 * structure.
772 *
773 * Locking: termios_mutex
774 */
775
776static int set_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
777{
778 int retval;
779 struct sgttyb tmp;
780 struct ktermios termios;
781
782 retval = tty_check_change(tty);
783 if (retval)
784 return retval;
785
786 if (copy_from_user(&tmp, sgttyb, sizeof(tmp)))
787 return -EFAULT;
788
789 mutex_lock(&tty->termios_mutex);
790 termios = *tty->termios;
791 termios.c_cc[VERASE] = tmp.sg_erase;
792 termios.c_cc[VKILL] = tmp.sg_kill;
793 set_sgflags(&termios, tmp.sg_flags);
794 /* Try and encode into Bfoo format */
795#ifdef BOTHER
796 tty_termios_encode_baud_rate(&termios, termios.c_ispeed,
797 termios.c_ospeed);
798#endif
799 mutex_unlock(&tty->termios_mutex);
800 tty_set_termios(tty, &termios);
801 return 0;
802}
803#endif
804
805#ifdef TIOCGETC
806static int get_tchars(struct tty_struct *tty, struct tchars __user *tchars)
807{
808 struct tchars tmp;
809
810 mutex_lock(&tty->termios_mutex);
811 tmp.t_intrc = tty->termios->c_cc[VINTR];
812 tmp.t_quitc = tty->termios->c_cc[VQUIT];
813 tmp.t_startc = tty->termios->c_cc[VSTART];
814 tmp.t_stopc = tty->termios->c_cc[VSTOP];
815 tmp.t_eofc = tty->termios->c_cc[VEOF];
816 tmp.t_brkc = tty->termios->c_cc[VEOL2]; /* what is brkc anyway? */
817 mutex_unlock(&tty->termios_mutex);
818 return copy_to_user(tchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
819}
820
821static int set_tchars(struct tty_struct *tty, struct tchars __user *tchars)
822{
823 struct tchars tmp;
824
825 if (copy_from_user(&tmp, tchars, sizeof(tmp)))
826 return -EFAULT;
827 mutex_lock(&tty->termios_mutex);
828 tty->termios->c_cc[VINTR] = tmp.t_intrc;
829 tty->termios->c_cc[VQUIT] = tmp.t_quitc;
830 tty->termios->c_cc[VSTART] = tmp.t_startc;
831 tty->termios->c_cc[VSTOP] = tmp.t_stopc;
832 tty->termios->c_cc[VEOF] = tmp.t_eofc;
833 tty->termios->c_cc[VEOL2] = tmp.t_brkc; /* what is brkc anyway? */
834 mutex_unlock(&tty->termios_mutex);
835 return 0;
836}
837#endif
838
839#ifdef TIOCGLTC
840static int get_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
841{
842 struct ltchars tmp;
843
844 mutex_lock(&tty->termios_mutex);
845 tmp.t_suspc = tty->termios->c_cc[VSUSP];
846 /* what is dsuspc anyway? */
847 tmp.t_dsuspc = tty->termios->c_cc[VSUSP];
848 tmp.t_rprntc = tty->termios->c_cc[VREPRINT];
849 /* what is flushc anyway? */
850 tmp.t_flushc = tty->termios->c_cc[VEOL2];
851 tmp.t_werasc = tty->termios->c_cc[VWERASE];
852 tmp.t_lnextc = tty->termios->c_cc[VLNEXT];
853 mutex_unlock(&tty->termios_mutex);
854 return copy_to_user(ltchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
855}
856
857static int set_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
858{
859 struct ltchars tmp;
860
861 if (copy_from_user(&tmp, ltchars, sizeof(tmp)))
862 return -EFAULT;
863
864 mutex_lock(&tty->termios_mutex);
865 tty->termios->c_cc[VSUSP] = tmp.t_suspc;
866 /* what is dsuspc anyway? */
867 tty->termios->c_cc[VEOL2] = tmp.t_dsuspc;
868 tty->termios->c_cc[VREPRINT] = tmp.t_rprntc;
869 /* what is flushc anyway? */
870 tty->termios->c_cc[VEOL2] = tmp.t_flushc;
871 tty->termios->c_cc[VWERASE] = tmp.t_werasc;
872 tty->termios->c_cc[VLNEXT] = tmp.t_lnextc;
873 mutex_unlock(&tty->termios_mutex);
874 return 0;
875}
876#endif
877
878/**
879 * send_prio_char - send priority character
880 *
881 * Send a high priority character to the tty even if stopped
882 *
883 * Locking: none for xchar method, write ordering for write method.
884 */
885
886static int send_prio_char(struct tty_struct *tty, char ch)
887{
888 int was_stopped = tty->stopped;
889
890 if (tty->ops->send_xchar) {
891 tty->ops->send_xchar(tty, ch);
892 return 0;
893 }
894
895 if (tty_write_lock(tty, 0) < 0)
896 return -ERESTARTSYS;
897
898 if (was_stopped)
899 start_tty(tty);
900 tty->ops->write(tty, &ch, 1);
901 if (was_stopped)
902 stop_tty(tty);
903 tty_write_unlock(tty);
904 return 0;
905}
906
907/**
908 * tty_change_softcar - carrier change ioctl helper
909 * @tty: tty to update
910 * @arg: enable/disable CLOCAL
911 *
912 * Perform a change to the CLOCAL state and call into the driver
913 * layer to make it visible. All done with the termios mutex
914 */
915
916static int tty_change_softcar(struct tty_struct *tty, int arg)
917{
918 int ret = 0;
919 int bit = arg ? CLOCAL : 0;
920 struct ktermios old;
921
922 mutex_lock(&tty->termios_mutex);
923 old = *tty->termios;
924 tty->termios->c_cflag &= ~CLOCAL;
925 tty->termios->c_cflag |= bit;
926 if (tty->ops->set_termios)
927 tty->ops->set_termios(tty, &old);
928 if ((tty->termios->c_cflag & CLOCAL) != bit)
929 ret = -EINVAL;
930 mutex_unlock(&tty->termios_mutex);
931 return ret;
932}
933
934/**
935 * tty_mode_ioctl - mode related ioctls
936 * @tty: tty for the ioctl
937 * @file: file pointer for the tty
938 * @cmd: command
939 * @arg: ioctl argument
940 *
941 * Perform non line discipline specific mode control ioctls. This
942 * is designed to be called by line disciplines to ensure they provide
943 * consistent mode setting.
944 */
945
946int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
947 unsigned int cmd, unsigned long arg)
948{
949 struct tty_struct *real_tty;
950 void __user *p = (void __user *)arg;
951 int ret = 0;
952 struct ktermios kterm;
953
954 BUG_ON(file == NULL);
955
956 if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
957 tty->driver->subtype == PTY_TYPE_MASTER)
958 real_tty = tty->link;
959 else
960 real_tty = tty;
961
962 switch (cmd) {
963#ifdef TIOCGETP
964 case TIOCGETP:
965 return get_sgttyb(real_tty, (struct sgttyb __user *) arg);
966 case TIOCSETP:
967 case TIOCSETN:
968 return set_sgttyb(real_tty, (struct sgttyb __user *) arg);
969#endif
970#ifdef TIOCGETC
971 case TIOCGETC:
972 return get_tchars(real_tty, p);
973 case TIOCSETC:
974 return set_tchars(real_tty, p);
975#endif
976#ifdef TIOCGLTC
977 case TIOCGLTC:
978 return get_ltchars(real_tty, p);
979 case TIOCSLTC:
980 return set_ltchars(real_tty, p);
981#endif
982 case TCSETSF:
983 return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_OLD);
984 case TCSETSW:
985 return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_OLD);
986 case TCSETS:
987 return set_termios(real_tty, p, TERMIOS_OLD);
988#ifndef TCGETS2
989 case TCGETS:
990 copy_termios(real_tty, &kterm);
991 if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
992 ret = -EFAULT;
993 return ret;
994#else
995 case TCGETS:
996 copy_termios(real_tty, &kterm);
997 if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
998 ret = -EFAULT;
999 return ret;
1000 case TCGETS2:
1001 copy_termios(real_tty, &kterm);
1002 if (kernel_termios_to_user_termios((struct termios2 __user *)arg, &kterm))
1003 ret = -EFAULT;
1004 return ret;
1005 case TCSETSF2:
1006 return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT);
1007 case TCSETSW2:
1008 return set_termios(real_tty, p, TERMIOS_WAIT);
1009 case TCSETS2:
1010 return set_termios(real_tty, p, 0);
1011#endif
1012 case TCGETA:
1013 return get_termio(real_tty, p);
1014 case TCSETAF:
1015 return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_TERMIO);
1016 case TCSETAW:
1017 return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_TERMIO);
1018 case TCSETA:
1019 return set_termios(real_tty, p, TERMIOS_TERMIO);
1020#ifndef TCGETS2
1021 case TIOCGLCKTRMIOS:
1022 copy_termios_locked(real_tty, &kterm);
1023 if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
1024 ret = -EFAULT;
1025 return ret;
1026 case TIOCSLCKTRMIOS:
1027 if (!capable(CAP_SYS_ADMIN))
1028 return -EPERM;
1029 copy_termios_locked(real_tty, &kterm);
1030 if (user_termios_to_kernel_termios(&kterm,
1031 (struct termios __user *) arg))
1032 return -EFAULT;
1033 mutex_lock(&real_tty->termios_mutex);
1034 memcpy(real_tty->termios_locked, &kterm, sizeof(struct ktermios));
1035 mutex_unlock(&real_tty->termios_mutex);
1036 return 0;
1037#else
1038 case TIOCGLCKTRMIOS:
1039 copy_termios_locked(real_tty, &kterm);
1040 if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
1041 ret = -EFAULT;
1042 return ret;
1043 case TIOCSLCKTRMIOS:
1044 if (!capable(CAP_SYS_ADMIN))
1045 return -EPERM;
1046 copy_termios_locked(real_tty, &kterm);
1047 if (user_termios_to_kernel_termios_1(&kterm,
1048 (struct termios __user *) arg))
1049 return -EFAULT;
1050 mutex_lock(&real_tty->termios_mutex);
1051 memcpy(real_tty->termios_locked, &kterm, sizeof(struct ktermios));
1052 mutex_unlock(&real_tty->termios_mutex);
1053 return ret;
1054#endif
1055#ifdef TCGETX
1056 case TCGETX: {
1057 struct termiox ktermx;
1058 if (real_tty->termiox == NULL)
1059 return -EINVAL;
1060 mutex_lock(&real_tty->termios_mutex);
1061 memcpy(&ktermx, real_tty->termiox, sizeof(struct termiox));
1062 mutex_unlock(&real_tty->termios_mutex);
1063 if (copy_to_user(p, &ktermx, sizeof(struct termiox)))
1064 ret = -EFAULT;
1065 return ret;
1066 }
1067 case TCSETX:
1068 return set_termiox(real_tty, p, 0);
1069 case TCSETXW:
1070 return set_termiox(real_tty, p, TERMIOS_WAIT);
1071 case TCSETXF:
1072 return set_termiox(real_tty, p, TERMIOS_FLUSH);
1073#endif
1074 case TIOCGSOFTCAR:
1075 copy_termios(real_tty, &kterm);
1076 ret = put_user((kterm.c_cflag & CLOCAL) ? 1 : 0,
1077 (int __user *)arg);
1078 return ret;
1079 case TIOCSSOFTCAR:
1080 if (get_user(arg, (unsigned int __user *) arg))
1081 return -EFAULT;
1082 return tty_change_softcar(real_tty, arg);
1083 default:
1084 return -ENOIOCTLCMD;
1085 }
1086}
1087EXPORT_SYMBOL_GPL(tty_mode_ioctl);
1088
1089int tty_perform_flush(struct tty_struct *tty, unsigned long arg)
1090{
1091 struct tty_ldisc *ld;
1092 int retval = tty_check_change(tty);
1093 if (retval)
1094 return retval;
1095
1096 ld = tty_ldisc_ref_wait(tty);
1097 switch (arg) {
1098 case TCIFLUSH:
1099 if (ld && ld->ops->flush_buffer)
1100 ld->ops->flush_buffer(tty);
1101 break;
1102 case TCIOFLUSH:
1103 if (ld && ld->ops->flush_buffer)
1104 ld->ops->flush_buffer(tty);
1105 /* fall through */
1106 case TCOFLUSH:
1107 tty_driver_flush_buffer(tty);
1108 break;
1109 default:
1110 tty_ldisc_deref(ld);
1111 return -EINVAL;
1112 }
1113 tty_ldisc_deref(ld);
1114 return 0;
1115}
1116EXPORT_SYMBOL_GPL(tty_perform_flush);
1117
1118int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
1119 unsigned int cmd, unsigned long arg)
1120{
1121 unsigned long flags;
1122 int retval;
1123
1124 switch (cmd) {
1125 case TCXONC:
1126 retval = tty_check_change(tty);
1127 if (retval)
1128 return retval;
1129 switch (arg) {
1130 case TCOOFF:
1131 if (!tty->flow_stopped) {
1132 tty->flow_stopped = 1;
1133 stop_tty(tty);
1134 }
1135 break;
1136 case TCOON:
1137 if (tty->flow_stopped) {
1138 tty->flow_stopped = 0;
1139 start_tty(tty);
1140 }
1141 break;
1142 case TCIOFF:
1143 if (STOP_CHAR(tty) != __DISABLED_CHAR)
1144 return send_prio_char(tty, STOP_CHAR(tty));
1145 break;
1146 case TCION:
1147 if (START_CHAR(tty) != __DISABLED_CHAR)
1148 return send_prio_char(tty, START_CHAR(tty));
1149 break;
1150 default:
1151 return -EINVAL;
1152 }
1153 return 0;
1154 case TCFLSH:
1155 return tty_perform_flush(tty, arg);
1156 case TIOCPKT:
1157 {
1158 int pktmode;
1159
1160 if (tty->driver->type != TTY_DRIVER_TYPE_PTY ||
1161 tty->driver->subtype != PTY_TYPE_MASTER)
1162 return -ENOTTY;
1163 if (get_user(pktmode, (int __user *) arg))
1164 return -EFAULT;
1165 spin_lock_irqsave(&tty->ctrl_lock, flags);
1166 if (pktmode) {
1167 if (!tty->packet) {
1168 tty->packet = 1;
1169 tty->link->ctrl_status = 0;
1170 }
1171 } else
1172 tty->packet = 0;
1173 spin_unlock_irqrestore(&tty->ctrl_lock, flags);
1174 return 0;
1175 }
1176 default:
1177 /* Try the mode commands */
1178 return tty_mode_ioctl(tty, file, cmd, arg);
1179 }
1180}
1181EXPORT_SYMBOL(n_tty_ioctl_helper);