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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 rwsem 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 down_write(&tty->termios_rwsem);
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 tty->flow_change = 0;
110 up_write(&tty->termios_rwsem);
111}
112EXPORT_SYMBOL(tty_throttle);
113
114/**
115 * tty_unthrottle - flow control
116 * @tty: terminal
117 *
118 * Indicate that a tty may continue transmitting data down the stack.
119 * Takes the termios rwsem to protect against parallel throttle/unthrottle
120 * and also to ensure the driver can consistently reference its own
121 * termios data at this point when implementing software flow control.
122 *
123 * Drivers should however remember that the stack can issue a throttle,
124 * then change flow control method, then unthrottle.
125 */
126
127void tty_unthrottle(struct tty_struct *tty)
128{
129 down_write(&tty->termios_rwsem);
130 if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) &&
131 tty->ops->unthrottle)
132 tty->ops->unthrottle(tty);
133 tty->flow_change = 0;
134 up_write(&tty->termios_rwsem);
135}
136EXPORT_SYMBOL(tty_unthrottle);
137
138/**
139 * tty_throttle_safe - flow control
140 * @tty: terminal
141 *
142 * Similar to tty_throttle() but will only attempt throttle
143 * if tty->flow_change is TTY_THROTTLE_SAFE. Prevents an accidental
144 * throttle due to race conditions when throttling is conditional
145 * on factors evaluated prior to throttling.
146 *
147 * Returns 0 if tty is throttled (or was already throttled)
148 */
149
150int tty_throttle_safe(struct tty_struct *tty)
151{
152 int ret = 0;
153
154 mutex_lock(&tty->throttle_mutex);
155 if (!test_bit(TTY_THROTTLED, &tty->flags)) {
156 if (tty->flow_change != TTY_THROTTLE_SAFE)
157 ret = 1;
158 else {
159 set_bit(TTY_THROTTLED, &tty->flags);
160 if (tty->ops->throttle)
161 tty->ops->throttle(tty);
162 }
163 }
164 mutex_unlock(&tty->throttle_mutex);
165
166 return ret;
167}
168
169/**
170 * tty_unthrottle_safe - flow control
171 * @tty: terminal
172 *
173 * Similar to tty_unthrottle() but will only attempt unthrottle
174 * if tty->flow_change is TTY_UNTHROTTLE_SAFE. Prevents an accidental
175 * unthrottle due to race conditions when unthrottling is conditional
176 * on factors evaluated prior to unthrottling.
177 *
178 * Returns 0 if tty is unthrottled (or was already unthrottled)
179 */
180
181int tty_unthrottle_safe(struct tty_struct *tty)
182{
183 int ret = 0;
184
185 mutex_lock(&tty->throttle_mutex);
186 if (test_bit(TTY_THROTTLED, &tty->flags)) {
187 if (tty->flow_change != TTY_UNTHROTTLE_SAFE)
188 ret = 1;
189 else {
190 clear_bit(TTY_THROTTLED, &tty->flags);
191 if (tty->ops->unthrottle)
192 tty->ops->unthrottle(tty);
193 }
194 }
195 mutex_unlock(&tty->throttle_mutex);
196
197 return ret;
198}
199
200/**
201 * tty_wait_until_sent - wait for I/O to finish
202 * @tty: tty we are waiting for
203 * @timeout: how long we will wait
204 *
205 * Wait for characters pending in a tty driver to hit the wire, or
206 * for a timeout to occur (eg due to flow control)
207 *
208 * Locking: none
209 */
210
211void tty_wait_until_sent(struct tty_struct *tty, long timeout)
212{
213#ifdef TTY_DEBUG_WAIT_UNTIL_SENT
214 char buf[64];
215
216 printk(KERN_DEBUG "%s wait until sent...\n", tty_name(tty, buf));
217#endif
218 if (!timeout)
219 timeout = MAX_SCHEDULE_TIMEOUT;
220 if (wait_event_interruptible_timeout(tty->write_wait,
221 !tty_chars_in_buffer(tty), timeout) >= 0) {
222 if (tty->ops->wait_until_sent)
223 tty->ops->wait_until_sent(tty, timeout);
224 }
225}
226EXPORT_SYMBOL(tty_wait_until_sent);
227
228
229/*
230 * Termios Helper Methods
231 */
232
233static void unset_locked_termios(struct ktermios *termios,
234 struct ktermios *old,
235 struct ktermios *locked)
236{
237 int i;
238
239#define NOSET_MASK(x, y, z) (x = ((x) & ~(z)) | ((y) & (z)))
240
241 if (!locked) {
242 printk(KERN_WARNING "Warning?!? termios_locked is NULL.\n");
243 return;
244 }
245
246 NOSET_MASK(termios->c_iflag, old->c_iflag, locked->c_iflag);
247 NOSET_MASK(termios->c_oflag, old->c_oflag, locked->c_oflag);
248 NOSET_MASK(termios->c_cflag, old->c_cflag, locked->c_cflag);
249 NOSET_MASK(termios->c_lflag, old->c_lflag, locked->c_lflag);
250 termios->c_line = locked->c_line ? old->c_line : termios->c_line;
251 for (i = 0; i < NCCS; i++)
252 termios->c_cc[i] = locked->c_cc[i] ?
253 old->c_cc[i] : termios->c_cc[i];
254 /* FIXME: What should we do for i/ospeed */
255}
256
257/*
258 * Routine which returns the baud rate of the tty
259 *
260 * Note that the baud_table needs to be kept in sync with the
261 * include/asm/termbits.h file.
262 */
263static const speed_t baud_table[] = {
264 0, 50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
265 9600, 19200, 38400, 57600, 115200, 230400, 460800,
266#ifdef __sparc__
267 76800, 153600, 307200, 614400, 921600
268#else
269 500000, 576000, 921600, 1000000, 1152000, 1500000, 2000000,
270 2500000, 3000000, 3500000, 4000000
271#endif
272};
273
274#ifndef __sparc__
275static const tcflag_t baud_bits[] = {
276 B0, B50, B75, B110, B134, B150, B200, B300, B600,
277 B1200, B1800, B2400, B4800, B9600, B19200, B38400,
278 B57600, B115200, B230400, B460800, B500000, B576000,
279 B921600, B1000000, B1152000, B1500000, B2000000, B2500000,
280 B3000000, B3500000, B4000000
281};
282#else
283static const tcflag_t baud_bits[] = {
284 B0, B50, B75, B110, B134, B150, B200, B300, B600,
285 B1200, B1800, B2400, B4800, B9600, B19200, B38400,
286 B57600, B115200, B230400, B460800, B76800, B153600,
287 B307200, B614400, B921600
288};
289#endif
290
291static int n_baud_table = ARRAY_SIZE(baud_table);
292
293/**
294 * tty_termios_baud_rate
295 * @termios: termios structure
296 *
297 * Convert termios baud rate data into a speed. This should be called
298 * with the termios lock held if this termios is a terminal termios
299 * structure. May change the termios data. Device drivers can call this
300 * function but should use ->c_[io]speed directly as they are updated.
301 *
302 * Locking: none
303 */
304
305speed_t tty_termios_baud_rate(struct ktermios *termios)
306{
307 unsigned int cbaud;
308
309 cbaud = termios->c_cflag & CBAUD;
310
311#ifdef BOTHER
312 /* Magic token for arbitrary speed via c_ispeed/c_ospeed */
313 if (cbaud == BOTHER)
314 return termios->c_ospeed;
315#endif
316 if (cbaud & CBAUDEX) {
317 cbaud &= ~CBAUDEX;
318
319 if (cbaud < 1 || cbaud + 15 > n_baud_table)
320 termios->c_cflag &= ~CBAUDEX;
321 else
322 cbaud += 15;
323 }
324 return baud_table[cbaud];
325}
326EXPORT_SYMBOL(tty_termios_baud_rate);
327
328/**
329 * tty_termios_input_baud_rate
330 * @termios: termios structure
331 *
332 * Convert termios baud rate data into a speed. This should be called
333 * with the termios lock held if this termios is a terminal termios
334 * structure. May change the termios data. Device drivers can call this
335 * function but should use ->c_[io]speed directly as they are updated.
336 *
337 * Locking: none
338 */
339
340speed_t tty_termios_input_baud_rate(struct ktermios *termios)
341{
342#ifdef IBSHIFT
343 unsigned int cbaud = (termios->c_cflag >> IBSHIFT) & CBAUD;
344
345 if (cbaud == B0)
346 return tty_termios_baud_rate(termios);
347
348 /* Magic token for arbitrary speed via c_ispeed*/
349 if (cbaud == BOTHER)
350 return termios->c_ispeed;
351
352 if (cbaud & CBAUDEX) {
353 cbaud &= ~CBAUDEX;
354
355 if (cbaud < 1 || cbaud + 15 > n_baud_table)
356 termios->c_cflag &= ~(CBAUDEX << IBSHIFT);
357 else
358 cbaud += 15;
359 }
360 return baud_table[cbaud];
361#else
362 return tty_termios_baud_rate(termios);
363#endif
364}
365EXPORT_SYMBOL(tty_termios_input_baud_rate);
366
367/**
368 * tty_termios_encode_baud_rate
369 * @termios: ktermios structure holding user requested state
370 * @ispeed: input speed
371 * @ospeed: output speed
372 *
373 * Encode the speeds set into the passed termios structure. This is
374 * used as a library helper for drivers so that they can report back
375 * the actual speed selected when it differs from the speed requested
376 *
377 * For maximal back compatibility with legacy SYS5/POSIX *nix behaviour
378 * we need to carefully set the bits when the user does not get the
379 * desired speed. We allow small margins and preserve as much of possible
380 * of the input intent to keep compatibility.
381 *
382 * Locking: Caller should hold termios lock. This is already held
383 * when calling this function from the driver termios handler.
384 *
385 * The ifdefs deal with platforms whose owners have yet to update them
386 * and will all go away once this is done.
387 */
388
389void tty_termios_encode_baud_rate(struct ktermios *termios,
390 speed_t ibaud, speed_t obaud)
391{
392 int i = 0;
393 int ifound = -1, ofound = -1;
394 int iclose = ibaud/50, oclose = obaud/50;
395 int ibinput = 0;
396
397 if (obaud == 0) /* CD dropped */
398 ibaud = 0; /* Clear ibaud to be sure */
399
400 termios->c_ispeed = ibaud;
401 termios->c_ospeed = obaud;
402
403#ifdef BOTHER
404 /* If the user asked for a precise weird speed give a precise weird
405 answer. If they asked for a Bfoo speed they many have problems
406 digesting non-exact replies so fuzz a bit */
407
408 if ((termios->c_cflag & CBAUD) == BOTHER)
409 oclose = 0;
410 if (((termios->c_cflag >> IBSHIFT) & CBAUD) == BOTHER)
411 iclose = 0;
412 if ((termios->c_cflag >> IBSHIFT) & CBAUD)
413 ibinput = 1; /* An input speed was specified */
414#endif
415 termios->c_cflag &= ~CBAUD;
416
417 /*
418 * Our goal is to find a close match to the standard baud rate
419 * returned. Walk the baud rate table and if we get a very close
420 * match then report back the speed as a POSIX Bxxxx value by
421 * preference
422 */
423
424 do {
425 if (obaud - oclose <= baud_table[i] &&
426 obaud + oclose >= baud_table[i]) {
427 termios->c_cflag |= baud_bits[i];
428 ofound = i;
429 }
430 if (ibaud - iclose <= baud_table[i] &&
431 ibaud + iclose >= baud_table[i]) {
432 /* For the case input == output don't set IBAUD bits
433 if the user didn't do so */
434 if (ofound == i && !ibinput)
435 ifound = i;
436#ifdef IBSHIFT
437 else {
438 ifound = i;
439 termios->c_cflag |= (baud_bits[i] << IBSHIFT);
440 }
441#endif
442 }
443 } while (++i < n_baud_table);
444
445 /*
446 * If we found no match then use BOTHER if provided or warn
447 * the user their platform maintainer needs to wake up if not.
448 */
449#ifdef BOTHER
450 if (ofound == -1)
451 termios->c_cflag |= BOTHER;
452 /* Set exact input bits only if the input and output differ or the
453 user already did */
454 if (ifound == -1 && (ibaud != obaud || ibinput))
455 termios->c_cflag |= (BOTHER << IBSHIFT);
456#else
457 if (ifound == -1 || ofound == -1) {
458 printk_once(KERN_WARNING "tty: Unable to return correct "
459 "speed data as your architecture needs updating.\n");
460 }
461#endif
462}
463EXPORT_SYMBOL_GPL(tty_termios_encode_baud_rate);
464
465/**
466 * tty_encode_baud_rate - set baud rate of the tty
467 * @ibaud: input baud rate
468 * @obad: output baud rate
469 *
470 * Update the current termios data for the tty with the new speed
471 * settings. The caller must hold the termios_rwsem for the tty in
472 * question.
473 */
474
475void tty_encode_baud_rate(struct tty_struct *tty, speed_t ibaud, speed_t obaud)
476{
477 tty_termios_encode_baud_rate(&tty->termios, ibaud, obaud);
478}
479EXPORT_SYMBOL_GPL(tty_encode_baud_rate);
480
481/**
482 * tty_termios_copy_hw - copy hardware settings
483 * @new: New termios
484 * @old: Old termios
485 *
486 * Propagate the hardware specific terminal setting bits from
487 * the old termios structure to the new one. This is used in cases
488 * where the hardware does not support reconfiguration or as a helper
489 * in some cases where only minimal reconfiguration is supported
490 */
491
492void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old)
493{
494 /* The bits a dumb device handles in software. Smart devices need
495 to always provide a set_termios method */
496 new->c_cflag &= HUPCL | CREAD | CLOCAL;
497 new->c_cflag |= old->c_cflag & ~(HUPCL | CREAD | CLOCAL);
498 new->c_ispeed = old->c_ispeed;
499 new->c_ospeed = old->c_ospeed;
500}
501EXPORT_SYMBOL(tty_termios_copy_hw);
502
503/**
504 * tty_termios_hw_change - check for setting change
505 * @a: termios
506 * @b: termios to compare
507 *
508 * Check if any of the bits that affect a dumb device have changed
509 * between the two termios structures, or a speed change is needed.
510 */
511
512int tty_termios_hw_change(struct ktermios *a, struct ktermios *b)
513{
514 if (a->c_ispeed != b->c_ispeed || a->c_ospeed != b->c_ospeed)
515 return 1;
516 if ((a->c_cflag ^ b->c_cflag) & ~(HUPCL | CREAD | CLOCAL))
517 return 1;
518 return 0;
519}
520EXPORT_SYMBOL(tty_termios_hw_change);
521
522/**
523 * tty_set_termios - update termios values
524 * @tty: tty to update
525 * @new_termios: desired new value
526 *
527 * Perform updates to the termios values set on this terminal. There
528 * is a bit of layering violation here with n_tty in terms of the
529 * internal knowledge of this function.
530 *
531 * Locking: termios_rwsem
532 */
533
534int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios)
535{
536 struct ktermios old_termios;
537 struct tty_ldisc *ld;
538 unsigned long flags;
539
540 /*
541 * Perform the actual termios internal changes under lock.
542 */
543
544
545 /* FIXME: we need to decide on some locking/ordering semantics
546 for the set_termios notification eventually */
547 down_write(&tty->termios_rwsem);
548 old_termios = tty->termios;
549 tty->termios = *new_termios;
550 unset_locked_termios(&tty->termios, &old_termios, &tty->termios_locked);
551
552 /* See if packet mode change of state. */
553 if (tty->link && tty->link->packet) {
554 int extproc = (old_termios.c_lflag & EXTPROC) |
555 (tty->termios.c_lflag & EXTPROC);
556 int old_flow = ((old_termios.c_iflag & IXON) &&
557 (old_termios.c_cc[VSTOP] == '\023') &&
558 (old_termios.c_cc[VSTART] == '\021'));
559 int new_flow = (I_IXON(tty) &&
560 STOP_CHAR(tty) == '\023' &&
561 START_CHAR(tty) == '\021');
562 if ((old_flow != new_flow) || extproc) {
563 spin_lock_irqsave(&tty->ctrl_lock, flags);
564 if (old_flow != new_flow) {
565 tty->ctrl_status &= ~(TIOCPKT_DOSTOP | TIOCPKT_NOSTOP);
566 if (new_flow)
567 tty->ctrl_status |= TIOCPKT_DOSTOP;
568 else
569 tty->ctrl_status |= TIOCPKT_NOSTOP;
570 }
571 if (extproc)
572 tty->ctrl_status |= TIOCPKT_IOCTL;
573 spin_unlock_irqrestore(&tty->ctrl_lock, flags);
574 wake_up_interruptible(&tty->link->read_wait);
575 }
576 }
577
578 if (tty->ops->set_termios)
579 (*tty->ops->set_termios)(tty, &old_termios);
580 else
581 tty_termios_copy_hw(&tty->termios, &old_termios);
582
583 ld = tty_ldisc_ref(tty);
584 if (ld != NULL) {
585 if (ld->ops->set_termios)
586 (ld->ops->set_termios)(tty, &old_termios);
587 tty_ldisc_deref(ld);
588 }
589 up_write(&tty->termios_rwsem);
590 return 0;
591}
592EXPORT_SYMBOL_GPL(tty_set_termios);
593
594/**
595 * set_termios - set termios values for a tty
596 * @tty: terminal device
597 * @arg: user data
598 * @opt: option information
599 *
600 * Helper function to prepare termios data and run necessary other
601 * functions before using tty_set_termios to do the actual changes.
602 *
603 * Locking:
604 * Called functions take ldisc and termios_rwsem locks
605 */
606
607static int set_termios(struct tty_struct *tty, void __user *arg, int opt)
608{
609 struct ktermios tmp_termios;
610 struct tty_ldisc *ld;
611 int retval = tty_check_change(tty);
612
613 if (retval)
614 return retval;
615
616 down_read(&tty->termios_rwsem);
617 tmp_termios = tty->termios;
618 up_read(&tty->termios_rwsem);
619
620 if (opt & TERMIOS_TERMIO) {
621 if (user_termio_to_kernel_termios(&tmp_termios,
622 (struct termio __user *)arg))
623 return -EFAULT;
624#ifdef TCGETS2
625 } else if (opt & TERMIOS_OLD) {
626 if (user_termios_to_kernel_termios_1(&tmp_termios,
627 (struct termios __user *)arg))
628 return -EFAULT;
629 } else {
630 if (user_termios_to_kernel_termios(&tmp_termios,
631 (struct termios2 __user *)arg))
632 return -EFAULT;
633 }
634#else
635 } else if (user_termios_to_kernel_termios(&tmp_termios,
636 (struct termios __user *)arg))
637 return -EFAULT;
638#endif
639
640 /* If old style Bfoo values are used then load c_ispeed/c_ospeed
641 * with the real speed so its unconditionally usable */
642 tmp_termios.c_ispeed = tty_termios_input_baud_rate(&tmp_termios);
643 tmp_termios.c_ospeed = tty_termios_baud_rate(&tmp_termios);
644
645 ld = tty_ldisc_ref(tty);
646
647 if (ld != NULL) {
648 if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
649 ld->ops->flush_buffer(tty);
650 tty_ldisc_deref(ld);
651 }
652
653 if (opt & TERMIOS_WAIT) {
654 tty_wait_until_sent(tty, 0);
655 if (signal_pending(current))
656 return -ERESTARTSYS;
657 }
658
659 tty_set_termios(tty, &tmp_termios);
660
661 /* FIXME: Arguably if tmp_termios == tty->termios AND the
662 actual requested termios was not tmp_termios then we may
663 want to return an error as no user requested change has
664 succeeded */
665 return 0;
666}
667
668static void copy_termios(struct tty_struct *tty, struct ktermios *kterm)
669{
670 down_read(&tty->termios_rwsem);
671 *kterm = tty->termios;
672 up_read(&tty->termios_rwsem);
673}
674
675static void copy_termios_locked(struct tty_struct *tty, struct ktermios *kterm)
676{
677 down_read(&tty->termios_rwsem);
678 *kterm = tty->termios_locked;
679 up_read(&tty->termios_rwsem);
680}
681
682static int get_termio(struct tty_struct *tty, struct termio __user *termio)
683{
684 struct ktermios kterm;
685 copy_termios(tty, &kterm);
686 if (kernel_termios_to_user_termio(termio, &kterm))
687 return -EFAULT;
688 return 0;
689}
690
691
692#ifdef TCGETX
693
694/**
695 * set_termiox - set termiox fields if possible
696 * @tty: terminal
697 * @arg: termiox structure from user
698 * @opt: option flags for ioctl type
699 *
700 * Implement the device calling points for the SYS5 termiox ioctl
701 * interface in Linux
702 */
703
704static int set_termiox(struct tty_struct *tty, void __user *arg, int opt)
705{
706 struct termiox tnew;
707 struct tty_ldisc *ld;
708
709 if (tty->termiox == NULL)
710 return -EINVAL;
711 if (copy_from_user(&tnew, arg, sizeof(struct termiox)))
712 return -EFAULT;
713
714 ld = tty_ldisc_ref(tty);
715 if (ld != NULL) {
716 if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
717 ld->ops->flush_buffer(tty);
718 tty_ldisc_deref(ld);
719 }
720 if (opt & TERMIOS_WAIT) {
721 tty_wait_until_sent(tty, 0);
722 if (signal_pending(current))
723 return -ERESTARTSYS;
724 }
725
726 down_write(&tty->termios_rwsem);
727 if (tty->ops->set_termiox)
728 tty->ops->set_termiox(tty, &tnew);
729 up_write(&tty->termios_rwsem);
730 return 0;
731}
732
733#endif
734
735
736#ifdef TIOCGETP
737/*
738 * These are deprecated, but there is limited support..
739 *
740 * The "sg_flags" translation is a joke..
741 */
742static int get_sgflags(struct tty_struct *tty)
743{
744 int flags = 0;
745
746 if (!(tty->termios.c_lflag & ICANON)) {
747 if (tty->termios.c_lflag & ISIG)
748 flags |= 0x02; /* cbreak */
749 else
750 flags |= 0x20; /* raw */
751 }
752 if (tty->termios.c_lflag & ECHO)
753 flags |= 0x08; /* echo */
754 if (tty->termios.c_oflag & OPOST)
755 if (tty->termios.c_oflag & ONLCR)
756 flags |= 0x10; /* crmod */
757 return flags;
758}
759
760static int get_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
761{
762 struct sgttyb tmp;
763
764 down_read(&tty->termios_rwsem);
765 tmp.sg_ispeed = tty->termios.c_ispeed;
766 tmp.sg_ospeed = tty->termios.c_ospeed;
767 tmp.sg_erase = tty->termios.c_cc[VERASE];
768 tmp.sg_kill = tty->termios.c_cc[VKILL];
769 tmp.sg_flags = get_sgflags(tty);
770 up_read(&tty->termios_rwsem);
771
772 return copy_to_user(sgttyb, &tmp, sizeof(tmp)) ? -EFAULT : 0;
773}
774
775static void set_sgflags(struct ktermios *termios, int flags)
776{
777 termios->c_iflag = ICRNL | IXON;
778 termios->c_oflag = 0;
779 termios->c_lflag = ISIG | ICANON;
780 if (flags & 0x02) { /* cbreak */
781 termios->c_iflag = 0;
782 termios->c_lflag &= ~ICANON;
783 }
784 if (flags & 0x08) { /* echo */
785 termios->c_lflag |= ECHO | ECHOE | ECHOK |
786 ECHOCTL | ECHOKE | IEXTEN;
787 }
788 if (flags & 0x10) { /* crmod */
789 termios->c_oflag |= OPOST | ONLCR;
790 }
791 if (flags & 0x20) { /* raw */
792 termios->c_iflag = 0;
793 termios->c_lflag &= ~(ISIG | ICANON);
794 }
795 if (!(termios->c_lflag & ICANON)) {
796 termios->c_cc[VMIN] = 1;
797 termios->c_cc[VTIME] = 0;
798 }
799}
800
801/**
802 * set_sgttyb - set legacy terminal values
803 * @tty: tty structure
804 * @sgttyb: pointer to old style terminal structure
805 *
806 * Updates a terminal from the legacy BSD style terminal information
807 * structure.
808 *
809 * Locking: termios_rwsem
810 */
811
812static int set_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
813{
814 int retval;
815 struct sgttyb tmp;
816 struct ktermios termios;
817
818 retval = tty_check_change(tty);
819 if (retval)
820 return retval;
821
822 if (copy_from_user(&tmp, sgttyb, sizeof(tmp)))
823 return -EFAULT;
824
825 down_write(&tty->termios_rwsem);
826 termios = tty->termios;
827 termios.c_cc[VERASE] = tmp.sg_erase;
828 termios.c_cc[VKILL] = tmp.sg_kill;
829 set_sgflags(&termios, tmp.sg_flags);
830 /* Try and encode into Bfoo format */
831#ifdef BOTHER
832 tty_termios_encode_baud_rate(&termios, termios.c_ispeed,
833 termios.c_ospeed);
834#endif
835 up_write(&tty->termios_rwsem);
836 tty_set_termios(tty, &termios);
837 return 0;
838}
839#endif
840
841#ifdef TIOCGETC
842static int get_tchars(struct tty_struct *tty, struct tchars __user *tchars)
843{
844 struct tchars tmp;
845
846 down_read(&tty->termios_rwsem);
847 tmp.t_intrc = tty->termios.c_cc[VINTR];
848 tmp.t_quitc = tty->termios.c_cc[VQUIT];
849 tmp.t_startc = tty->termios.c_cc[VSTART];
850 tmp.t_stopc = tty->termios.c_cc[VSTOP];
851 tmp.t_eofc = tty->termios.c_cc[VEOF];
852 tmp.t_brkc = tty->termios.c_cc[VEOL2]; /* what is brkc anyway? */
853 up_read(&tty->termios_rwsem);
854 return copy_to_user(tchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
855}
856
857static int set_tchars(struct tty_struct *tty, struct tchars __user *tchars)
858{
859 struct tchars tmp;
860
861 if (copy_from_user(&tmp, tchars, sizeof(tmp)))
862 return -EFAULT;
863 down_write(&tty->termios_rwsem);
864 tty->termios.c_cc[VINTR] = tmp.t_intrc;
865 tty->termios.c_cc[VQUIT] = tmp.t_quitc;
866 tty->termios.c_cc[VSTART] = tmp.t_startc;
867 tty->termios.c_cc[VSTOP] = tmp.t_stopc;
868 tty->termios.c_cc[VEOF] = tmp.t_eofc;
869 tty->termios.c_cc[VEOL2] = tmp.t_brkc; /* what is brkc anyway? */
870 up_write(&tty->termios_rwsem);
871 return 0;
872}
873#endif
874
875#ifdef TIOCGLTC
876static int get_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
877{
878 struct ltchars tmp;
879
880 down_read(&tty->termios_rwsem);
881 tmp.t_suspc = tty->termios.c_cc[VSUSP];
882 /* what is dsuspc anyway? */
883 tmp.t_dsuspc = tty->termios.c_cc[VSUSP];
884 tmp.t_rprntc = tty->termios.c_cc[VREPRINT];
885 /* what is flushc anyway? */
886 tmp.t_flushc = tty->termios.c_cc[VEOL2];
887 tmp.t_werasc = tty->termios.c_cc[VWERASE];
888 tmp.t_lnextc = tty->termios.c_cc[VLNEXT];
889 up_read(&tty->termios_rwsem);
890 return copy_to_user(ltchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
891}
892
893static int set_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
894{
895 struct ltchars tmp;
896
897 if (copy_from_user(&tmp, ltchars, sizeof(tmp)))
898 return -EFAULT;
899
900 down_write(&tty->termios_rwsem);
901 tty->termios.c_cc[VSUSP] = tmp.t_suspc;
902 /* what is dsuspc anyway? */
903 tty->termios.c_cc[VEOL2] = tmp.t_dsuspc;
904 tty->termios.c_cc[VREPRINT] = tmp.t_rprntc;
905 /* what is flushc anyway? */
906 tty->termios.c_cc[VEOL2] = tmp.t_flushc;
907 tty->termios.c_cc[VWERASE] = tmp.t_werasc;
908 tty->termios.c_cc[VLNEXT] = tmp.t_lnextc;
909 up_write(&tty->termios_rwsem);
910 return 0;
911}
912#endif
913
914/**
915 * send_prio_char - send priority character
916 *
917 * Send a high priority character to the tty even if stopped
918 *
919 * Locking: none for xchar method, write ordering for write method.
920 */
921
922static int send_prio_char(struct tty_struct *tty, char ch)
923{
924 int was_stopped = tty->stopped;
925
926 if (tty->ops->send_xchar) {
927 tty->ops->send_xchar(tty, ch);
928 return 0;
929 }
930
931 if (tty_write_lock(tty, 0) < 0)
932 return -ERESTARTSYS;
933
934 if (was_stopped)
935 start_tty(tty);
936 tty->ops->write(tty, &ch, 1);
937 if (was_stopped)
938 stop_tty(tty);
939 tty_write_unlock(tty);
940 return 0;
941}
942
943/**
944 * tty_change_softcar - carrier change ioctl helper
945 * @tty: tty to update
946 * @arg: enable/disable CLOCAL
947 *
948 * Perform a change to the CLOCAL state and call into the driver
949 * layer to make it visible. All done with the termios rwsem
950 */
951
952static int tty_change_softcar(struct tty_struct *tty, int arg)
953{
954 int ret = 0;
955 int bit = arg ? CLOCAL : 0;
956 struct ktermios old;
957
958 down_write(&tty->termios_rwsem);
959 old = tty->termios;
960 tty->termios.c_cflag &= ~CLOCAL;
961 tty->termios.c_cflag |= bit;
962 if (tty->ops->set_termios)
963 tty->ops->set_termios(tty, &old);
964 if ((tty->termios.c_cflag & CLOCAL) != bit)
965 ret = -EINVAL;
966 up_write(&tty->termios_rwsem);
967 return ret;
968}
969
970/**
971 * tty_mode_ioctl - mode related ioctls
972 * @tty: tty for the ioctl
973 * @file: file pointer for the tty
974 * @cmd: command
975 * @arg: ioctl argument
976 *
977 * Perform non line discipline specific mode control ioctls. This
978 * is designed to be called by line disciplines to ensure they provide
979 * consistent mode setting.
980 */
981
982int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
983 unsigned int cmd, unsigned long arg)
984{
985 struct tty_struct *real_tty;
986 void __user *p = (void __user *)arg;
987 int ret = 0;
988 struct ktermios kterm;
989
990 BUG_ON(file == NULL);
991
992 if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
993 tty->driver->subtype == PTY_TYPE_MASTER)
994 real_tty = tty->link;
995 else
996 real_tty = tty;
997
998 switch (cmd) {
999#ifdef TIOCGETP
1000 case TIOCGETP:
1001 return get_sgttyb(real_tty, (struct sgttyb __user *) arg);
1002 case TIOCSETP:
1003 case TIOCSETN:
1004 return set_sgttyb(real_tty, (struct sgttyb __user *) arg);
1005#endif
1006#ifdef TIOCGETC
1007 case TIOCGETC:
1008 return get_tchars(real_tty, p);
1009 case TIOCSETC:
1010 return set_tchars(real_tty, p);
1011#endif
1012#ifdef TIOCGLTC
1013 case TIOCGLTC:
1014 return get_ltchars(real_tty, p);
1015 case TIOCSLTC:
1016 return set_ltchars(real_tty, p);
1017#endif
1018 case TCSETSF:
1019 return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_OLD);
1020 case TCSETSW:
1021 return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_OLD);
1022 case TCSETS:
1023 return set_termios(real_tty, p, TERMIOS_OLD);
1024#ifndef TCGETS2
1025 case TCGETS:
1026 copy_termios(real_tty, &kterm);
1027 if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
1028 ret = -EFAULT;
1029 return ret;
1030#else
1031 case TCGETS:
1032 copy_termios(real_tty, &kterm);
1033 if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
1034 ret = -EFAULT;
1035 return ret;
1036 case TCGETS2:
1037 copy_termios(real_tty, &kterm);
1038 if (kernel_termios_to_user_termios((struct termios2 __user *)arg, &kterm))
1039 ret = -EFAULT;
1040 return ret;
1041 case TCSETSF2:
1042 return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT);
1043 case TCSETSW2:
1044 return set_termios(real_tty, p, TERMIOS_WAIT);
1045 case TCSETS2:
1046 return set_termios(real_tty, p, 0);
1047#endif
1048 case TCGETA:
1049 return get_termio(real_tty, p);
1050 case TCSETAF:
1051 return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_TERMIO);
1052 case TCSETAW:
1053 return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_TERMIO);
1054 case TCSETA:
1055 return set_termios(real_tty, p, TERMIOS_TERMIO);
1056#ifndef TCGETS2
1057 case TIOCGLCKTRMIOS:
1058 copy_termios_locked(real_tty, &kterm);
1059 if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
1060 ret = -EFAULT;
1061 return ret;
1062 case TIOCSLCKTRMIOS:
1063 if (!capable(CAP_SYS_ADMIN))
1064 return -EPERM;
1065 copy_termios_locked(real_tty, &kterm);
1066 if (user_termios_to_kernel_termios(&kterm,
1067 (struct termios __user *) arg))
1068 return -EFAULT;
1069 down_write(&real_tty->termios_rwsem);
1070 real_tty->termios_locked = kterm;
1071 up_write(&real_tty->termios_rwsem);
1072 return 0;
1073#else
1074 case TIOCGLCKTRMIOS:
1075 copy_termios_locked(real_tty, &kterm);
1076 if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
1077 ret = -EFAULT;
1078 return ret;
1079 case TIOCSLCKTRMIOS:
1080 if (!capable(CAP_SYS_ADMIN))
1081 return -EPERM;
1082 copy_termios_locked(real_tty, &kterm);
1083 if (user_termios_to_kernel_termios_1(&kterm,
1084 (struct termios __user *) arg))
1085 return -EFAULT;
1086 down_write(&real_tty->termios_rwsem);
1087 real_tty->termios_locked = kterm;
1088 up_write(&real_tty->termios_rwsem);
1089 return ret;
1090#endif
1091#ifdef TCGETX
1092 case TCGETX: {
1093 struct termiox ktermx;
1094 if (real_tty->termiox == NULL)
1095 return -EINVAL;
1096 down_read(&real_tty->termios_rwsem);
1097 memcpy(&ktermx, real_tty->termiox, sizeof(struct termiox));
1098 up_read(&real_tty->termios_rwsem);
1099 if (copy_to_user(p, &ktermx, sizeof(struct termiox)))
1100 ret = -EFAULT;
1101 return ret;
1102 }
1103 case TCSETX:
1104 return set_termiox(real_tty, p, 0);
1105 case TCSETXW:
1106 return set_termiox(real_tty, p, TERMIOS_WAIT);
1107 case TCSETXF:
1108 return set_termiox(real_tty, p, TERMIOS_FLUSH);
1109#endif
1110 case TIOCGSOFTCAR:
1111 copy_termios(real_tty, &kterm);
1112 ret = put_user((kterm.c_cflag & CLOCAL) ? 1 : 0,
1113 (int __user *)arg);
1114 return ret;
1115 case TIOCSSOFTCAR:
1116 if (get_user(arg, (unsigned int __user *) arg))
1117 return -EFAULT;
1118 return tty_change_softcar(real_tty, arg);
1119 default:
1120 return -ENOIOCTLCMD;
1121 }
1122}
1123EXPORT_SYMBOL_GPL(tty_mode_ioctl);
1124
1125
1126/* Caller guarantees ldisc reference is held */
1127static int __tty_perform_flush(struct tty_struct *tty, unsigned long arg)
1128{
1129 struct tty_ldisc *ld = tty->ldisc;
1130
1131 switch (arg) {
1132 case TCIFLUSH:
1133 if (ld && ld->ops->flush_buffer) {
1134 ld->ops->flush_buffer(tty);
1135 tty_unthrottle(tty);
1136 }
1137 break;
1138 case TCIOFLUSH:
1139 if (ld && ld->ops->flush_buffer) {
1140 ld->ops->flush_buffer(tty);
1141 tty_unthrottle(tty);
1142 }
1143 /* fall through */
1144 case TCOFLUSH:
1145 tty_driver_flush_buffer(tty);
1146 break;
1147 default:
1148 return -EINVAL;
1149 }
1150 return 0;
1151}
1152
1153int tty_perform_flush(struct tty_struct *tty, unsigned long arg)
1154{
1155 struct tty_ldisc *ld;
1156 int retval = tty_check_change(tty);
1157 if (retval)
1158 return retval;
1159
1160 ld = tty_ldisc_ref_wait(tty);
1161 retval = __tty_perform_flush(tty, arg);
1162 if (ld)
1163 tty_ldisc_deref(ld);
1164 return retval;
1165}
1166EXPORT_SYMBOL_GPL(tty_perform_flush);
1167
1168int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
1169 unsigned int cmd, unsigned long arg)
1170{
1171 int retval;
1172
1173 switch (cmd) {
1174 case TCXONC:
1175 retval = tty_check_change(tty);
1176 if (retval)
1177 return retval;
1178 switch (arg) {
1179 case TCOOFF:
1180 if (!tty->flow_stopped) {
1181 tty->flow_stopped = 1;
1182 stop_tty(tty);
1183 }
1184 break;
1185 case TCOON:
1186 if (tty->flow_stopped) {
1187 tty->flow_stopped = 0;
1188 start_tty(tty);
1189 }
1190 break;
1191 case TCIOFF:
1192 if (STOP_CHAR(tty) != __DISABLED_CHAR)
1193 return send_prio_char(tty, STOP_CHAR(tty));
1194 break;
1195 case TCION:
1196 if (START_CHAR(tty) != __DISABLED_CHAR)
1197 return send_prio_char(tty, START_CHAR(tty));
1198 break;
1199 default:
1200 return -EINVAL;
1201 }
1202 return 0;
1203 case TCFLSH:
1204 retval = tty_check_change(tty);
1205 if (retval)
1206 return retval;
1207 return __tty_perform_flush(tty, arg);
1208 default:
1209 /* Try the mode commands */
1210 return tty_mode_ioctl(tty, file, cmd, arg);
1211 }
1212}
1213EXPORT_SYMBOL(n_tty_ioctl_helper);
1214
1215#ifdef CONFIG_COMPAT
1216long n_tty_compat_ioctl_helper(struct tty_struct *tty, struct file *file,
1217 unsigned int cmd, unsigned long arg)
1218{
1219 switch (cmd) {
1220 case TIOCGLCKTRMIOS:
1221 case TIOCSLCKTRMIOS:
1222 return tty_mode_ioctl(tty, file, cmd, (unsigned long) compat_ptr(arg));
1223 default:
1224 return -ENOIOCTLCMD;
1225 }
1226}
1227EXPORT_SYMBOL(n_tty_compat_ioctl_helper);
1228#endif
1229