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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/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#include <linux/termios_internal.h>
25#include "tty.h"
26
27#include <asm/io.h>
28#include <linux/uaccess.h>
29
30#undef TTY_DEBUG_WAIT_UNTIL_SENT
31
32#ifdef TTY_DEBUG_WAIT_UNTIL_SENT
33# define tty_debug_wait_until_sent(tty, f, args...) tty_debug(tty, f, ##args)
34#else
35# define tty_debug_wait_until_sent(tty, f, args...) do {} while (0)
36#endif
37
38#undef DEBUG
39
40/*
41 * Internal flag options for termios setting behavior
42 */
43#define TERMIOS_FLUSH 1
44#define TERMIOS_WAIT 2
45#define TERMIOS_TERMIO 4
46#define TERMIOS_OLD 8
47
48
49/**
50 * tty_chars_in_buffer - characters pending
51 * @tty: terminal
52 *
53 * Return the number of bytes of data in the device private
54 * output queue. If no private method is supplied there is assumed
55 * to be no queue on the device.
56 */
57
58unsigned int tty_chars_in_buffer(struct tty_struct *tty)
59{
60 if (tty->ops->chars_in_buffer)
61 return tty->ops->chars_in_buffer(tty);
62 return 0;
63}
64EXPORT_SYMBOL(tty_chars_in_buffer);
65
66/**
67 * tty_write_room - write queue space
68 * @tty: terminal
69 *
70 * Return the number of bytes that can be queued to this device
71 * at the present time. The result should be treated as a guarantee
72 * and the driver cannot offer a value it later shrinks by more than
73 * the number of bytes written. If no method is provided 2K is always
74 * returned and data may be lost as there will be no flow control.
75 */
76
77unsigned int tty_write_room(struct tty_struct *tty)
78{
79 if (tty->ops->write_room)
80 return tty->ops->write_room(tty);
81 return 2048;
82}
83EXPORT_SYMBOL(tty_write_room);
84
85/**
86 * tty_driver_flush_buffer - discard internal buffer
87 * @tty: terminal
88 *
89 * Discard the internal output buffer for this device. If no method
90 * is provided then either the buffer cannot be hardware flushed or
91 * there is no buffer driver side.
92 */
93void tty_driver_flush_buffer(struct tty_struct *tty)
94{
95 if (tty->ops->flush_buffer)
96 tty->ops->flush_buffer(tty);
97}
98EXPORT_SYMBOL(tty_driver_flush_buffer);
99
100/**
101 * tty_unthrottle - flow control
102 * @tty: terminal
103 *
104 * Indicate that a tty may continue transmitting data down the stack.
105 * Takes the termios rwsem to protect against parallel throttle/unthrottle
106 * and also to ensure the driver can consistently reference its own
107 * termios data at this point when implementing software flow control.
108 *
109 * Drivers should however remember that the stack can issue a throttle,
110 * then change flow control method, then unthrottle.
111 */
112
113void tty_unthrottle(struct tty_struct *tty)
114{
115 down_write(&tty->termios_rwsem);
116 if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) &&
117 tty->ops->unthrottle)
118 tty->ops->unthrottle(tty);
119 tty->flow_change = 0;
120 up_write(&tty->termios_rwsem);
121}
122EXPORT_SYMBOL(tty_unthrottle);
123
124/**
125 * tty_throttle_safe - flow control
126 * @tty: terminal
127 *
128 * Indicate that a tty should stop transmitting data down the stack.
129 * tty_throttle_safe will only attempt throttle if tty->flow_change is
130 * TTY_THROTTLE_SAFE. Prevents an accidental throttle due to race
131 * conditions when throttling is conditional on factors evaluated prior to
132 * throttling.
133 *
134 * Returns 0 if tty is throttled (or was already throttled)
135 */
136
137int tty_throttle_safe(struct tty_struct *tty)
138{
139 int ret = 0;
140
141 mutex_lock(&tty->throttle_mutex);
142 if (!tty_throttled(tty)) {
143 if (tty->flow_change != TTY_THROTTLE_SAFE)
144 ret = 1;
145 else {
146 set_bit(TTY_THROTTLED, &tty->flags);
147 if (tty->ops->throttle)
148 tty->ops->throttle(tty);
149 }
150 }
151 mutex_unlock(&tty->throttle_mutex);
152
153 return ret;
154}
155
156/**
157 * tty_unthrottle_safe - flow control
158 * @tty: terminal
159 *
160 * Similar to tty_unthrottle() but will only attempt unthrottle
161 * if tty->flow_change is TTY_UNTHROTTLE_SAFE. Prevents an accidental
162 * unthrottle due to race conditions when unthrottling is conditional
163 * on factors evaluated prior to unthrottling.
164 *
165 * Returns 0 if tty is unthrottled (or was already unthrottled)
166 */
167
168int tty_unthrottle_safe(struct tty_struct *tty)
169{
170 int ret = 0;
171
172 mutex_lock(&tty->throttle_mutex);
173 if (tty_throttled(tty)) {
174 if (tty->flow_change != TTY_UNTHROTTLE_SAFE)
175 ret = 1;
176 else {
177 clear_bit(TTY_THROTTLED, &tty->flags);
178 if (tty->ops->unthrottle)
179 tty->ops->unthrottle(tty);
180 }
181 }
182 mutex_unlock(&tty->throttle_mutex);
183
184 return ret;
185}
186
187/**
188 * tty_wait_until_sent - wait for I/O to finish
189 * @tty: tty we are waiting for
190 * @timeout: how long we will wait
191 *
192 * Wait for characters pending in a tty driver to hit the wire, or
193 * for a timeout to occur (eg due to flow control)
194 *
195 * Locking: none
196 */
197
198void tty_wait_until_sent(struct tty_struct *tty, long timeout)
199{
200 tty_debug_wait_until_sent(tty, "wait until sent, timeout=%ld\n", timeout);
201
202 if (!timeout)
203 timeout = MAX_SCHEDULE_TIMEOUT;
204
205 timeout = wait_event_interruptible_timeout(tty->write_wait,
206 !tty_chars_in_buffer(tty), timeout);
207 if (timeout <= 0)
208 return;
209
210 if (timeout == MAX_SCHEDULE_TIMEOUT)
211 timeout = 0;
212
213 if (tty->ops->wait_until_sent)
214 tty->ops->wait_until_sent(tty, timeout);
215}
216EXPORT_SYMBOL(tty_wait_until_sent);
217
218
219/*
220 * Termios Helper Methods
221 */
222
223static void unset_locked_termios(struct tty_struct *tty, const struct ktermios *old)
224{
225 struct ktermios *termios = &tty->termios;
226 struct ktermios *locked = &tty->termios_locked;
227 int i;
228
229#define NOSET_MASK(x, y, z) (x = ((x) & ~(z)) | ((y) & (z)))
230
231 NOSET_MASK(termios->c_iflag, old->c_iflag, locked->c_iflag);
232 NOSET_MASK(termios->c_oflag, old->c_oflag, locked->c_oflag);
233 NOSET_MASK(termios->c_cflag, old->c_cflag, locked->c_cflag);
234 NOSET_MASK(termios->c_lflag, old->c_lflag, locked->c_lflag);
235 termios->c_line = locked->c_line ? old->c_line : termios->c_line;
236 for (i = 0; i < NCCS; i++)
237 termios->c_cc[i] = locked->c_cc[i] ?
238 old->c_cc[i] : termios->c_cc[i];
239 /* FIXME: What should we do for i/ospeed */
240}
241
242/**
243 * tty_termios_copy_hw - copy hardware settings
244 * @new: New termios
245 * @old: Old termios
246 *
247 * Propagate the hardware specific terminal setting bits from
248 * the old termios structure to the new one. This is used in cases
249 * where the hardware does not support reconfiguration or as a helper
250 * in some cases where only minimal reconfiguration is supported
251 */
252
253void tty_termios_copy_hw(struct ktermios *new, const struct ktermios *old)
254{
255 /* The bits a dumb device handles in software. Smart devices need
256 to always provide a set_termios method */
257 new->c_cflag &= HUPCL | CREAD | CLOCAL;
258 new->c_cflag |= old->c_cflag & ~(HUPCL | CREAD | CLOCAL);
259 new->c_ispeed = old->c_ispeed;
260 new->c_ospeed = old->c_ospeed;
261}
262EXPORT_SYMBOL(tty_termios_copy_hw);
263
264/**
265 * tty_termios_hw_change - check for setting change
266 * @a: termios
267 * @b: termios to compare
268 *
269 * Check if any of the bits that affect a dumb device have changed
270 * between the two termios structures, or a speed change is needed.
271 */
272
273int tty_termios_hw_change(const struct ktermios *a, const struct ktermios *b)
274{
275 if (a->c_ispeed != b->c_ispeed || a->c_ospeed != b->c_ospeed)
276 return 1;
277 if ((a->c_cflag ^ b->c_cflag) & ~(HUPCL | CREAD | CLOCAL))
278 return 1;
279 return 0;
280}
281EXPORT_SYMBOL(tty_termios_hw_change);
282
283/**
284 * tty_get_char_size - get size of a character
285 * @cflag: termios cflag value
286 *
287 * Get the size (in bits) of a character depending on @cflag's %CSIZE
288 * setting.
289 */
290unsigned char tty_get_char_size(unsigned int cflag)
291{
292 switch (cflag & CSIZE) {
293 case CS5:
294 return 5;
295 case CS6:
296 return 6;
297 case CS7:
298 return 7;
299 case CS8:
300 default:
301 return 8;
302 }
303}
304EXPORT_SYMBOL_GPL(tty_get_char_size);
305
306/**
307 * tty_get_frame_size - get size of a frame
308 * @cflag: termios cflag value
309 *
310 * Get the size (in bits) of a frame depending on @cflag's %CSIZE, %CSTOPB,
311 * and %PARENB setting. The result is a sum of character size, start and
312 * stop bits -- one bit each -- second stop bit (if set), and parity bit
313 * (if set).
314 */
315unsigned char tty_get_frame_size(unsigned int cflag)
316{
317 unsigned char bits = 2 + tty_get_char_size(cflag);
318
319 if (cflag & CSTOPB)
320 bits++;
321 if (cflag & PARENB)
322 bits++;
323 if (cflag & ADDRB)
324 bits++;
325
326 return bits;
327}
328EXPORT_SYMBOL_GPL(tty_get_frame_size);
329
330/**
331 * tty_set_termios - update termios values
332 * @tty: tty to update
333 * @new_termios: desired new value
334 *
335 * Perform updates to the termios values set on this terminal.
336 * A master pty's termios should never be set.
337 *
338 * Locking: termios_rwsem
339 */
340
341int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios)
342{
343 struct ktermios old_termios;
344 struct tty_ldisc *ld;
345
346 WARN_ON(tty->driver->type == TTY_DRIVER_TYPE_PTY &&
347 tty->driver->subtype == PTY_TYPE_MASTER);
348 /*
349 * Perform the actual termios internal changes under lock.
350 */
351
352
353 /* FIXME: we need to decide on some locking/ordering semantics
354 for the set_termios notification eventually */
355 down_write(&tty->termios_rwsem);
356 old_termios = tty->termios;
357 tty->termios = *new_termios;
358 unset_locked_termios(tty, &old_termios);
359 /* Reset any ADDRB changes, ADDRB is changed through ->rs485_config() */
360 tty->termios.c_cflag ^= (tty->termios.c_cflag ^ old_termios.c_cflag) & ADDRB;
361
362 if (tty->ops->set_termios)
363 tty->ops->set_termios(tty, &old_termios);
364 else
365 tty_termios_copy_hw(&tty->termios, &old_termios);
366
367 ld = tty_ldisc_ref(tty);
368 if (ld != NULL) {
369 if (ld->ops->set_termios)
370 ld->ops->set_termios(tty, &old_termios);
371 tty_ldisc_deref(ld);
372 }
373 up_write(&tty->termios_rwsem);
374 return 0;
375}
376EXPORT_SYMBOL_GPL(tty_set_termios);
377
378
379/*
380 * Translate a "termio" structure into a "termios". Ugh.
381 */
382__weak int user_termio_to_kernel_termios(struct ktermios *termios,
383 struct termio __user *termio)
384{
385 struct termio v;
386
387 if (copy_from_user(&v, termio, sizeof(struct termio)))
388 return -EFAULT;
389
390 termios->c_iflag = (0xffff0000 & termios->c_iflag) | v.c_iflag;
391 termios->c_oflag = (0xffff0000 & termios->c_oflag) | v.c_oflag;
392 termios->c_cflag = (0xffff0000 & termios->c_cflag) | v.c_cflag;
393 termios->c_lflag = (0xffff0000 & termios->c_lflag) | v.c_lflag;
394 termios->c_line = (0xffff0000 & termios->c_lflag) | v.c_line;
395 memcpy(termios->c_cc, v.c_cc, NCC);
396 return 0;
397}
398
399/*
400 * Translate a "termios" structure into a "termio". Ugh.
401 */
402__weak int kernel_termios_to_user_termio(struct termio __user *termio,
403 struct ktermios *termios)
404{
405 struct termio v;
406 memset(&v, 0, sizeof(struct termio));
407 v.c_iflag = termios->c_iflag;
408 v.c_oflag = termios->c_oflag;
409 v.c_cflag = termios->c_cflag;
410 v.c_lflag = termios->c_lflag;
411 v.c_line = termios->c_line;
412 memcpy(v.c_cc, termios->c_cc, NCC);
413 return copy_to_user(termio, &v, sizeof(struct termio));
414}
415
416#ifdef TCGETS2
417__weak int user_termios_to_kernel_termios(struct ktermios *k,
418 struct termios2 __user *u)
419{
420 return copy_from_user(k, u, sizeof(struct termios2));
421}
422__weak int kernel_termios_to_user_termios(struct termios2 __user *u,
423 struct ktermios *k)
424{
425 return copy_to_user(u, k, sizeof(struct termios2));
426}
427__weak int user_termios_to_kernel_termios_1(struct ktermios *k,
428 struct termios __user *u)
429{
430 return copy_from_user(k, u, sizeof(struct termios));
431}
432__weak int kernel_termios_to_user_termios_1(struct termios __user *u,
433 struct ktermios *k)
434{
435 return copy_to_user(u, k, sizeof(struct termios));
436}
437
438#else
439
440__weak int user_termios_to_kernel_termios(struct ktermios *k,
441 struct termios __user *u)
442{
443 return copy_from_user(k, u, sizeof(struct termios));
444}
445__weak int kernel_termios_to_user_termios(struct termios __user *u,
446 struct ktermios *k)
447{
448 return copy_to_user(u, k, sizeof(struct termios));
449}
450#endif /* TCGETS2 */
451
452/**
453 * set_termios - set termios values for a tty
454 * @tty: terminal device
455 * @arg: user data
456 * @opt: option information
457 *
458 * Helper function to prepare termios data and run necessary other
459 * functions before using tty_set_termios to do the actual changes.
460 *
461 * Locking:
462 * Called functions take ldisc and termios_rwsem locks
463 */
464
465static int set_termios(struct tty_struct *tty, void __user *arg, int opt)
466{
467 struct ktermios tmp_termios;
468 struct tty_ldisc *ld;
469 int retval = tty_check_change(tty);
470
471 if (retval)
472 return retval;
473
474 down_read(&tty->termios_rwsem);
475 tmp_termios = tty->termios;
476 up_read(&tty->termios_rwsem);
477
478 if (opt & TERMIOS_TERMIO) {
479 if (user_termio_to_kernel_termios(&tmp_termios,
480 (struct termio __user *)arg))
481 return -EFAULT;
482#ifdef TCGETS2
483 } else if (opt & TERMIOS_OLD) {
484 if (user_termios_to_kernel_termios_1(&tmp_termios,
485 (struct termios __user *)arg))
486 return -EFAULT;
487 } else {
488 if (user_termios_to_kernel_termios(&tmp_termios,
489 (struct termios2 __user *)arg))
490 return -EFAULT;
491 }
492#else
493 } else if (user_termios_to_kernel_termios(&tmp_termios,
494 (struct termios __user *)arg))
495 return -EFAULT;
496#endif
497
498 /* If old style Bfoo values are used then load c_ispeed/c_ospeed
499 * with the real speed so its unconditionally usable */
500 tmp_termios.c_ispeed = tty_termios_input_baud_rate(&tmp_termios);
501 tmp_termios.c_ospeed = tty_termios_baud_rate(&tmp_termios);
502
503 ld = tty_ldisc_ref(tty);
504
505 if (ld != NULL) {
506 if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
507 ld->ops->flush_buffer(tty);
508 tty_ldisc_deref(ld);
509 }
510
511 if (opt & TERMIOS_WAIT) {
512 tty_wait_until_sent(tty, 0);
513 if (signal_pending(current))
514 return -ERESTARTSYS;
515 }
516
517 tty_set_termios(tty, &tmp_termios);
518
519 /* FIXME: Arguably if tmp_termios == tty->termios AND the
520 actual requested termios was not tmp_termios then we may
521 want to return an error as no user requested change has
522 succeeded */
523 return 0;
524}
525
526static void copy_termios(struct tty_struct *tty, struct ktermios *kterm)
527{
528 down_read(&tty->termios_rwsem);
529 *kterm = tty->termios;
530 up_read(&tty->termios_rwsem);
531}
532
533static void copy_termios_locked(struct tty_struct *tty, struct ktermios *kterm)
534{
535 down_read(&tty->termios_rwsem);
536 *kterm = tty->termios_locked;
537 up_read(&tty->termios_rwsem);
538}
539
540static int get_termio(struct tty_struct *tty, struct termio __user *termio)
541{
542 struct ktermios kterm;
543 copy_termios(tty, &kterm);
544 if (kernel_termios_to_user_termio(termio, &kterm))
545 return -EFAULT;
546 return 0;
547}
548
549#ifdef TIOCGETP
550/*
551 * These are deprecated, but there is limited support..
552 *
553 * The "sg_flags" translation is a joke..
554 */
555static int get_sgflags(struct tty_struct *tty)
556{
557 int flags = 0;
558
559 if (!L_ICANON(tty)) {
560 if (L_ISIG(tty))
561 flags |= 0x02; /* cbreak */
562 else
563 flags |= 0x20; /* raw */
564 }
565 if (L_ECHO(tty))
566 flags |= 0x08; /* echo */
567 if (O_OPOST(tty))
568 if (O_ONLCR(tty))
569 flags |= 0x10; /* crmod */
570 return flags;
571}
572
573static int get_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
574{
575 struct sgttyb tmp;
576
577 down_read(&tty->termios_rwsem);
578 tmp.sg_ispeed = tty->termios.c_ispeed;
579 tmp.sg_ospeed = tty->termios.c_ospeed;
580 tmp.sg_erase = tty->termios.c_cc[VERASE];
581 tmp.sg_kill = tty->termios.c_cc[VKILL];
582 tmp.sg_flags = get_sgflags(tty);
583 up_read(&tty->termios_rwsem);
584
585 return copy_to_user(sgttyb, &tmp, sizeof(tmp)) ? -EFAULT : 0;
586}
587
588static void set_sgflags(struct ktermios *termios, int flags)
589{
590 termios->c_iflag = ICRNL | IXON;
591 termios->c_oflag = 0;
592 termios->c_lflag = ISIG | ICANON;
593 if (flags & 0x02) { /* cbreak */
594 termios->c_iflag = 0;
595 termios->c_lflag &= ~ICANON;
596 }
597 if (flags & 0x08) { /* echo */
598 termios->c_lflag |= ECHO | ECHOE | ECHOK |
599 ECHOCTL | ECHOKE | IEXTEN;
600 }
601 if (flags & 0x10) { /* crmod */
602 termios->c_oflag |= OPOST | ONLCR;
603 }
604 if (flags & 0x20) { /* raw */
605 termios->c_iflag = 0;
606 termios->c_lflag &= ~(ISIG | ICANON);
607 }
608 if (!(termios->c_lflag & ICANON)) {
609 termios->c_cc[VMIN] = 1;
610 termios->c_cc[VTIME] = 0;
611 }
612}
613
614/**
615 * set_sgttyb - set legacy terminal values
616 * @tty: tty structure
617 * @sgttyb: pointer to old style terminal structure
618 *
619 * Updates a terminal from the legacy BSD style terminal information
620 * structure.
621 *
622 * Locking: termios_rwsem
623 */
624
625static int set_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
626{
627 int retval;
628 struct sgttyb tmp;
629 struct ktermios termios;
630
631 retval = tty_check_change(tty);
632 if (retval)
633 return retval;
634
635 if (copy_from_user(&tmp, sgttyb, sizeof(tmp)))
636 return -EFAULT;
637
638 down_write(&tty->termios_rwsem);
639 termios = tty->termios;
640 termios.c_cc[VERASE] = tmp.sg_erase;
641 termios.c_cc[VKILL] = tmp.sg_kill;
642 set_sgflags(&termios, tmp.sg_flags);
643 /* Try and encode into Bfoo format */
644 tty_termios_encode_baud_rate(&termios, termios.c_ispeed,
645 termios.c_ospeed);
646 up_write(&tty->termios_rwsem);
647 tty_set_termios(tty, &termios);
648 return 0;
649}
650#endif
651
652#ifdef TIOCGETC
653static int get_tchars(struct tty_struct *tty, struct tchars __user *tchars)
654{
655 struct tchars tmp;
656
657 down_read(&tty->termios_rwsem);
658 tmp.t_intrc = tty->termios.c_cc[VINTR];
659 tmp.t_quitc = tty->termios.c_cc[VQUIT];
660 tmp.t_startc = tty->termios.c_cc[VSTART];
661 tmp.t_stopc = tty->termios.c_cc[VSTOP];
662 tmp.t_eofc = tty->termios.c_cc[VEOF];
663 tmp.t_brkc = tty->termios.c_cc[VEOL2]; /* what is brkc anyway? */
664 up_read(&tty->termios_rwsem);
665 return copy_to_user(tchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
666}
667
668static int set_tchars(struct tty_struct *tty, struct tchars __user *tchars)
669{
670 struct tchars tmp;
671
672 if (copy_from_user(&tmp, tchars, sizeof(tmp)))
673 return -EFAULT;
674 down_write(&tty->termios_rwsem);
675 tty->termios.c_cc[VINTR] = tmp.t_intrc;
676 tty->termios.c_cc[VQUIT] = tmp.t_quitc;
677 tty->termios.c_cc[VSTART] = tmp.t_startc;
678 tty->termios.c_cc[VSTOP] = tmp.t_stopc;
679 tty->termios.c_cc[VEOF] = tmp.t_eofc;
680 tty->termios.c_cc[VEOL2] = tmp.t_brkc; /* what is brkc anyway? */
681 up_write(&tty->termios_rwsem);
682 return 0;
683}
684#endif
685
686#ifdef TIOCGLTC
687static int get_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
688{
689 struct ltchars tmp;
690
691 down_read(&tty->termios_rwsem);
692 tmp.t_suspc = tty->termios.c_cc[VSUSP];
693 /* what is dsuspc anyway? */
694 tmp.t_dsuspc = tty->termios.c_cc[VSUSP];
695 tmp.t_rprntc = tty->termios.c_cc[VREPRINT];
696 /* what is flushc anyway? */
697 tmp.t_flushc = tty->termios.c_cc[VEOL2];
698 tmp.t_werasc = tty->termios.c_cc[VWERASE];
699 tmp.t_lnextc = tty->termios.c_cc[VLNEXT];
700 up_read(&tty->termios_rwsem);
701 return copy_to_user(ltchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
702}
703
704static int set_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
705{
706 struct ltchars tmp;
707
708 if (copy_from_user(&tmp, ltchars, sizeof(tmp)))
709 return -EFAULT;
710
711 down_write(&tty->termios_rwsem);
712 tty->termios.c_cc[VSUSP] = tmp.t_suspc;
713 /* what is dsuspc anyway? */
714 tty->termios.c_cc[VEOL2] = tmp.t_dsuspc;
715 tty->termios.c_cc[VREPRINT] = tmp.t_rprntc;
716 /* what is flushc anyway? */
717 tty->termios.c_cc[VEOL2] = tmp.t_flushc;
718 tty->termios.c_cc[VWERASE] = tmp.t_werasc;
719 tty->termios.c_cc[VLNEXT] = tmp.t_lnextc;
720 up_write(&tty->termios_rwsem);
721 return 0;
722}
723#endif
724
725/**
726 * tty_change_softcar - carrier change ioctl helper
727 * @tty: tty to update
728 * @arg: enable/disable CLOCAL
729 *
730 * Perform a change to the CLOCAL state and call into the driver
731 * layer to make it visible. All done with the termios rwsem
732 */
733
734static int tty_change_softcar(struct tty_struct *tty, int arg)
735{
736 int ret = 0;
737 int bit = arg ? CLOCAL : 0;
738 struct ktermios old;
739
740 down_write(&tty->termios_rwsem);
741 old = tty->termios;
742 tty->termios.c_cflag &= ~CLOCAL;
743 tty->termios.c_cflag |= bit;
744 if (tty->ops->set_termios)
745 tty->ops->set_termios(tty, &old);
746 if (C_CLOCAL(tty) != bit)
747 ret = -EINVAL;
748 up_write(&tty->termios_rwsem);
749 return ret;
750}
751
752/**
753 * tty_mode_ioctl - mode related ioctls
754 * @tty: tty for the ioctl
755 * @cmd: command
756 * @arg: ioctl argument
757 *
758 * Perform non line discipline specific mode control ioctls. This
759 * is designed to be called by line disciplines to ensure they provide
760 * consistent mode setting.
761 */
762
763int tty_mode_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
764{
765 struct tty_struct *real_tty;
766 void __user *p = (void __user *)arg;
767 int ret = 0;
768 struct ktermios kterm;
769
770 if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
771 tty->driver->subtype == PTY_TYPE_MASTER)
772 real_tty = tty->link;
773 else
774 real_tty = tty;
775
776 switch (cmd) {
777#ifdef TIOCGETP
778 case TIOCGETP:
779 return get_sgttyb(real_tty, (struct sgttyb __user *) arg);
780 case TIOCSETP:
781 case TIOCSETN:
782 return set_sgttyb(real_tty, (struct sgttyb __user *) arg);
783#endif
784#ifdef TIOCGETC
785 case TIOCGETC:
786 return get_tchars(real_tty, p);
787 case TIOCSETC:
788 return set_tchars(real_tty, p);
789#endif
790#ifdef TIOCGLTC
791 case TIOCGLTC:
792 return get_ltchars(real_tty, p);
793 case TIOCSLTC:
794 return set_ltchars(real_tty, p);
795#endif
796 case TCSETSF:
797 return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_OLD);
798 case TCSETSW:
799 return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_OLD);
800 case TCSETS:
801 return set_termios(real_tty, p, TERMIOS_OLD);
802#ifndef TCGETS2
803 case TCGETS:
804 copy_termios(real_tty, &kterm);
805 if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
806 ret = -EFAULT;
807 return ret;
808#else
809 case TCGETS:
810 copy_termios(real_tty, &kterm);
811 if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
812 ret = -EFAULT;
813 return ret;
814 case TCGETS2:
815 copy_termios(real_tty, &kterm);
816 if (kernel_termios_to_user_termios((struct termios2 __user *)arg, &kterm))
817 ret = -EFAULT;
818 return ret;
819 case TCSETSF2:
820 return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT);
821 case TCSETSW2:
822 return set_termios(real_tty, p, TERMIOS_WAIT);
823 case TCSETS2:
824 return set_termios(real_tty, p, 0);
825#endif
826 case TCGETA:
827 return get_termio(real_tty, p);
828 case TCSETAF:
829 return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_TERMIO);
830 case TCSETAW:
831 return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_TERMIO);
832 case TCSETA:
833 return set_termios(real_tty, p, TERMIOS_TERMIO);
834#ifndef TCGETS2
835 case TIOCGLCKTRMIOS:
836 copy_termios_locked(real_tty, &kterm);
837 if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
838 ret = -EFAULT;
839 return ret;
840 case TIOCSLCKTRMIOS:
841 if (!capable(CAP_SYS_ADMIN))
842 return -EPERM;
843 copy_termios_locked(real_tty, &kterm);
844 if (user_termios_to_kernel_termios(&kterm,
845 (struct termios __user *) arg))
846 return -EFAULT;
847 down_write(&real_tty->termios_rwsem);
848 real_tty->termios_locked = kterm;
849 up_write(&real_tty->termios_rwsem);
850 return 0;
851#else
852 case TIOCGLCKTRMIOS:
853 copy_termios_locked(real_tty, &kterm);
854 if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
855 ret = -EFAULT;
856 return ret;
857 case TIOCSLCKTRMIOS:
858 if (!capable(CAP_SYS_ADMIN))
859 return -EPERM;
860 copy_termios_locked(real_tty, &kterm);
861 if (user_termios_to_kernel_termios_1(&kterm,
862 (struct termios __user *) arg))
863 return -EFAULT;
864 down_write(&real_tty->termios_rwsem);
865 real_tty->termios_locked = kterm;
866 up_write(&real_tty->termios_rwsem);
867 return ret;
868#endif
869#ifdef TCGETX
870 case TCGETX:
871 case TCSETX:
872 case TCSETXW:
873 case TCSETXF:
874 return -ENOTTY;
875#endif
876 case TIOCGSOFTCAR:
877 copy_termios(real_tty, &kterm);
878 ret = put_user((kterm.c_cflag & CLOCAL) ? 1 : 0,
879 (int __user *)arg);
880 return ret;
881 case TIOCSSOFTCAR:
882 if (get_user(arg, (unsigned int __user *) arg))
883 return -EFAULT;
884 return tty_change_softcar(real_tty, arg);
885 default:
886 return -ENOIOCTLCMD;
887 }
888}
889EXPORT_SYMBOL_GPL(tty_mode_ioctl);
890
891
892/* Caller guarantees ldisc reference is held */
893static int __tty_perform_flush(struct tty_struct *tty, unsigned long arg)
894{
895 struct tty_ldisc *ld = tty->ldisc;
896
897 switch (arg) {
898 case TCIFLUSH:
899 if (ld && ld->ops->flush_buffer) {
900 ld->ops->flush_buffer(tty);
901 tty_unthrottle(tty);
902 }
903 break;
904 case TCIOFLUSH:
905 if (ld && ld->ops->flush_buffer) {
906 ld->ops->flush_buffer(tty);
907 tty_unthrottle(tty);
908 }
909 fallthrough;
910 case TCOFLUSH:
911 tty_driver_flush_buffer(tty);
912 break;
913 default:
914 return -EINVAL;
915 }
916 return 0;
917}
918
919int tty_perform_flush(struct tty_struct *tty, unsigned long arg)
920{
921 struct tty_ldisc *ld;
922 int retval = tty_check_change(tty);
923 if (retval)
924 return retval;
925
926 ld = tty_ldisc_ref_wait(tty);
927 retval = __tty_perform_flush(tty, arg);
928 if (ld)
929 tty_ldisc_deref(ld);
930 return retval;
931}
932EXPORT_SYMBOL_GPL(tty_perform_flush);
933
934int n_tty_ioctl_helper(struct tty_struct *tty, unsigned int cmd,
935 unsigned long arg)
936{
937 int retval;
938
939 switch (cmd) {
940 case TCXONC:
941 retval = tty_check_change(tty);
942 if (retval)
943 return retval;
944 switch (arg) {
945 case TCOOFF:
946 spin_lock_irq(&tty->flow.lock);
947 if (!tty->flow.tco_stopped) {
948 tty->flow.tco_stopped = true;
949 __stop_tty(tty);
950 }
951 spin_unlock_irq(&tty->flow.lock);
952 break;
953 case TCOON:
954 spin_lock_irq(&tty->flow.lock);
955 if (tty->flow.tco_stopped) {
956 tty->flow.tco_stopped = false;
957 __start_tty(tty);
958 }
959 spin_unlock_irq(&tty->flow.lock);
960 break;
961 case TCIOFF:
962 if (STOP_CHAR(tty) != __DISABLED_CHAR)
963 retval = tty_send_xchar(tty, STOP_CHAR(tty));
964 break;
965 case TCION:
966 if (START_CHAR(tty) != __DISABLED_CHAR)
967 retval = tty_send_xchar(tty, START_CHAR(tty));
968 break;
969 default:
970 return -EINVAL;
971 }
972 return retval;
973 case TCFLSH:
974 retval = tty_check_change(tty);
975 if (retval)
976 return retval;
977 return __tty_perform_flush(tty, arg);
978 default:
979 /* Try the mode commands */
980 return tty_mode_ioctl(tty, cmd, arg);
981 }
982}
983EXPORT_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#include <linux/compat.h>
23
24#include <asm/io.h>
25#include <asm/uaccess.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);
1182
1183#ifdef CONFIG_COMPAT
1184long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file,
1185 unsigned int cmd, unsigned long arg)
1186{
1187 switch (cmd) {
1188 case TIOCGLCKTRMIOS:
1189 case TIOCSLCKTRMIOS:
1190 return tty_mode_ioctl(tty, file, cmd, (unsigned long) compat_ptr(arg));
1191 default:
1192 return -ENOIOCTLCMD;
1193 }
1194}
1195EXPORT_SYMBOL(n_tty_compat_ioctl_helper);
1196#endif
1197