aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/char/tty_ioctl.c
blob: f19cf9d7792d57816b53cf0e697bda80fe07a50e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
/*
 *  linux/drivers/char/tty_ioctl.c
 *
 *  Copyright (C) 1991, 1992, 1993, 1994  Linus Torvalds
 *
 * Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
 * which can be dynamically activated and de-activated by the line
 * discipline handling modules (like SLIP).
 */

#include <linux/types.h>
#include <linux/termios.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/major.h>
#include <linux/tty.h>
#include <linux/fcntl.h>
#include <linux/string.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/bitops.h>

#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/system.h>

#undef TTY_DEBUG_WAIT_UNTIL_SENT

#undef	DEBUG

/*
 * Internal flag options for termios setting behavior
 */
#define TERMIOS_FLUSH	1
#define TERMIOS_WAIT	2
#define TERMIOS_TERMIO	4

void tty_wait_until_sent(struct tty_struct * tty, long timeout)
{
	DECLARE_WAITQUEUE(wait, current);

#ifdef TTY_DEBUG_WAIT_UNTIL_SENT
	char buf[64];
	
	printk(KERN_DEBUG "%s wait until sent...\n", tty_name(tty, buf));
#endif
	if (!tty->driver->chars_in_buffer)
		return;
	add_wait_queue(&tty->write_wait, &wait);
	if (!timeout)
		timeout = MAX_SCHEDULE_TIMEOUT;
	do {
#ifdef TTY_DEBUG_WAIT_UNTIL_SENT
		printk(KERN_DEBUG "waiting %s...(%d)\n", tty_name(tty, buf),
		       tty->driver->chars_in_buffer(tty));
#endif
		set_current_state(TASK_INTERRUPTIBLE);
		if (signal_pending(current))
			goto stop_waiting;
		if (!tty->driver->chars_in_buffer(tty))
			break;
		timeout = schedule_timeout(timeout);
	} while (timeout);
	if (tty->driver->wait_until_sent)
		tty->driver->wait_until_sent(tty, timeout);
stop_waiting:
	set_current_state(TASK_RUNNING);
	remove_wait_queue(&tty->write_wait, &wait);
}

EXPORT_SYMBOL(tty_wait_until_sent);

static void unset_locked_termios(struct termios *termios,
				 struct termios *old,
				 struct termios *locked)
{
	int	i;
	
#define NOSET_MASK(x,y,z) (x = ((x) & ~(z)) | ((y) & (z)))

	if (!locked) {
		printk(KERN_WARNING "Warning?!? termios_locked is NULL.\n");
		return;
	}

	NOSET_MASK(termios->c_iflag, old->c_iflag, locked->c_iflag);
	NOSET_MASK(termios->c_oflag, old->c_oflag, locked->c_oflag);
	NOSET_MASK(termios->c_cflag, old->c_cflag, locked->c_cflag);
	NOSET_MASK(termios->c_lflag, old->c_lflag, locked->c_lflag);
	termios->c_line = locked->c_line ? old->c_line : termios->c_line;
	for (i=0; i < NCCS; i++)
		termios->c_cc[i] = locked->c_cc[i] ?
			old->c_cc[i] : termios->c_cc[i];
}

static void change_termios(struct tty_struct * tty, struct termios * new_termios)
{
	int canon_change;
	struct termios old_termios = *tty->termios;
	struct tty_ldisc *ld;
	
	/*
	 *	Perform the actual termios internal changes under lock.
	 */
	 

	/* FIXME: we need to decide on some locking/ordering semantics
	   for the set_termios notification eventually */
	down(&tty->termios_sem);

	*tty->termios = *new_termios;
	unset_locked_termios(tty->termios, &old_termios, tty->termios_locked);
	canon_change = (old_termios.c_lflag ^ tty->termios->c_lflag) & ICANON;
	if (canon_change) {
		memset(&tty->read_flags, 0, sizeof tty->read_flags);
		tty->canon_head = tty->read_tail;
		tty->canon_data = 0;
		tty->erasing = 0;
	}
	
	
	if (canon_change && !L_ICANON(tty) && tty->read_cnt)
		/* Get characters left over from canonical mode. */
		wake_up_interruptible(&tty->read_wait);

	/* See if packet mode change of state. */

	if (tty->link && tty->link->packet) {
		int old_flow = ((old_termios.c_iflag & IXON) &&
				(old_termios.c_cc[VSTOP] == '\023') &&
				(old_termios.c_cc[VSTART] == '\021'));
		int new_flow = (I_IXON(tty) &&
				STOP_CHAR(tty) == '\023' &&
				START_CHAR(tty) == '\021');
		if (old_flow != new_flow) {
			tty->ctrl_status &= ~(TIOCPKT_DOSTOP | TIOCPKT_NOSTOP);
			if (new_flow)
				tty->ctrl_status |= TIOCPKT_DOSTOP;
			else
				tty->ctrl_status |= TIOCPKT_NOSTOP;
			wake_up_interruptible(&tty->link->read_wait);
		}
	}
	   
	if (tty->driver->set_termios)
		(*tty->driver->set_termios)(tty, &old_termios);

	ld = tty_ldisc_ref(tty);
	if (ld != NULL) {
		if (ld->set_termios)
			(ld->set_termios)(tty, &old_termios);
		tty_ldisc_deref(ld);
	}
	up(&tty->termios_sem);
}

static int set_termios(struct tty_struct * tty, void __user *arg, int opt)
{
	struct termios tmp_termios;
	struct tty_ldisc *ld;
	int retval = tty_check_change(tty);

	if (retval)
		return retval;

	if (opt & TERMIOS_TERMIO) {
		memcpy(&tmp_termios, tty->termios, sizeof(struct termios));
		if (user_termio_to_kernel_termios(&tmp_termios,
						(struct termio __user *)arg))
			return -EFAULT;
	} else {
		if (user_termios_to_kernel_termios(&tmp_termios,
						(struct termios __user *)arg))
			return -EFAULT;
	}

	ld = tty_ldisc_ref(tty);
	
	if (ld != NULL) {
		if ((opt & TERMIOS_FLUSH) && ld->flush_buffer)
			ld->flush_buffer(tty);
		tty_ldisc_deref(ld);
	}
	
	if (opt & TERMIOS_WAIT) {
		tty_wait_until_sent(tty, 0);
		if (signal_pending(current))
			return -EINTR;
	}

	change_termios(tty, &tmp_termios);
	return 0;
}

static int get_termio(struct tty_struct * tty, struct termio __user * termio)
{
	if (kernel_termios_to_user_termio(termio, tty->termios))
		return -EFAULT;
	return 0;
}

static unsigned long inq_canon(struct tty_struct * tty)
{
	int nr, head, tail;

	if (!tty->canon_data || !tty->read_buf)
		return 0;
	head = tty->canon_head;
	tail = tty->read_tail;
	nr = (head - tail) & (N_TTY_BUF_SIZE-1);
	/* Skip EOF-chars.. */
	while (head != tail) {
		if (test_bit(tail, tty->read_flags) &&
		    tty->read_buf[tail] == __DISABLED_CHAR)
			nr--;
		tail = (tail+1) & (N_TTY_BUF_SIZE-1);
	}
	return nr;
}

#ifdef TIOCGETP
/*
 * These are deprecated, but there is limited support..
 *
 * The "sg_flags" translation is a joke..
 */
static int get_sgflags(struct tty_struct * tty)
{
	int flags = 0;

	if (!(tty->termios->c_lflag & ICANON)) {
		if (tty->termios->c_lflag & ISIG)
			flags |= 0x02;		/* cbreak */
		else
			flags |= 0x20;		/* raw */
	}
	if (tty->termios->c_lflag & ECHO)
		flags |= 0x08;			/* echo */
	if (tty->termios->c_oflag & OPOST)
		if (tty->termios->c_oflag & ONLCR)
			flags |= 0x10;		/* crmod */
	return flags;
}

static int get_sgttyb(struct tty_struct * tty, struct sgttyb __user * sgttyb)
{
	struct sgttyb tmp;

	down(&tty->termios_sem);
	tmp.sg_ispeed = 0;
	tmp.sg_ospeed = 0;
	tmp.sg_erase = tty->termios->c_cc[VERASE];
	tmp.sg_kill = tty->termios->c_cc[VKILL];
	tmp.sg_flags = get_sgflags(tty);
	up(&tty->termios_sem);
	
	return copy_to_user(sgttyb, &tmp, sizeof(tmp)) ? -EFAULT : 0;
}

static void set_sgflags(struct termios * termios, int flags)
{
	termios->c_iflag = ICRNL | IXON;
	termios->c_oflag = 0;
	termios->c_lflag = ISIG | ICANON;
	if (flags & 0x02) {	/* cbreak */
		termios->c_iflag = 0;
		termios->c_lflag &= ~ICANON;
	}
	if (flags & 0x08) {		/* echo */
		termios->c_lflag |= ECHO | ECHOE | ECHOK |
				    ECHOCTL | ECHOKE | IEXTEN;
	}
	if (flags & 0x10) {		/* crmod */
		termios->c_oflag |= OPOST | ONLCR;
	}
	if (flags & 0x20) {	/* raw */
		termios->c_iflag = 0;
		termios->c_lflag &= ~(ISIG | ICANON);
	}
	if (!(termios->c_lflag & ICANON)) {
		termios->c_cc[VMIN] = 1;
		termios->c_cc[VTIME] = 0;
	}
}

static int set_sgttyb(struct tty_struct * tty, struct sgttyb __user * sgttyb)
{
	int retval;
	struct sgttyb tmp;
	struct termios termios;

	retval = tty_check_change(tty);
	if (retval)
		return retval;
	
	if (copy_from_user(&tmp, sgttyb, sizeof(tmp)))
		return -EFAULT;

	down(&tty->termios_sem);		
	termios =  *tty->termios;
	termios.c_cc[VERASE] = tmp.sg_erase;
	termios.c_cc[VKILL] = tmp.sg_kill;
	set_sgflags(&termios, tmp.sg_flags);
	up(&tty->termios_sem);
	change_termios(tty, &termios);
	return 0;
}
#endif

#ifdef TIOCGETC
static int get_tchars(struct tty_struct * tty, struct tchars __user * tchars)
{
	struct tchars tmp;

	tmp.t_intrc = tty->termios->c_cc[VINTR];
	tmp.t_quitc = tty->termios->c_cc[VQUIT];
	tmp.t_startc = tty->termios->c_cc[VSTART];
	tmp.t_stopc = tty->termios->c_cc[VSTOP];
	tmp.t_eofc = tty->termios->c_cc[VEOF];
	tmp.t_brkc = tty->termios->c_cc[VEOL2];	/* what is brkc anyway? */
	return copy_to_user(tchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
}

static int set_tchars(struct tty_struct * tty, struct tchars __user * tchars)
{
	struct tchars tmp;

	if (copy_from_user(&tmp, tchars, sizeof(tmp)))
		return -EFAULT;
	tty->termios->c_cc[VINTR] = tmp.t_intrc;
	tty->termios->c_cc[VQUIT] = tmp.t_quitc;
	tty->termios->c_cc[VSTART] = tmp.t_startc;
	tty->termios->c_cc[VSTOP] = tmp.t_stopc;
	tty->termios->c_cc[VEOF] = tmp.t_eofc;
	tty->termios->c_cc[VEOL2] = tmp.t_brkc;	/* what is brkc anyway? */
	return 0;
}
#endif

#ifdef TIOCGLTC
static int get_ltchars(struct tty_struct * tty, struct ltchars __user * ltchars)
{
	struct ltchars tmp;

	tmp.t_suspc = tty->termios->c_cc[VSUSP];
	tmp.t_dsuspc = tty->termios->c_cc[VSUSP];	/* what is dsuspc anyway? */
	tmp.t_rprntc = tty->termios->c_cc[VREPRINT];
	tmp.t_flushc = tty->termios->c_cc[VEOL2];	/* what is flushc anyway? */
	tmp.t_werasc = tty->termios->c_cc[VWERASE];
	tmp.t_lnextc = tty->termios->c_cc[VLNEXT];
	return copy_to_user(ltchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
}

static int set_ltchars(struct tty_struct * tty, struct ltchars __user * ltchars)
{
	struct ltchars tmp;

	if (copy_from_user(&tmp, ltchars, sizeof(tmp)))
		return -EFAULT;

	tty->termios->c_cc[VSUSP] = tmp.t_suspc;
	tty->termios->c_cc[VEOL2] = tmp.t_dsuspc;	/* what is dsuspc anyway? */
	tty->termios->c_cc[VREPRINT] = tmp.t_rprntc;
	tty->termios->c_cc[VEOL2] = tmp.t_flushc;	/* what is flushc anyway? */
	tty->termios->c_cc[VWERASE] = tmp.t_werasc;
	tty->termios->c_cc[VLNEXT] = tmp.t_lnextc;
	return 0;
}
#endif

/*
 * Send a high priority character to the tty.
 */
static void send_prio_char(struct tty_struct *tty, char ch)
{
	int	was_stopped = tty->stopped;

	if (tty->driver->send_xchar) {
		tty->driver->send_xchar(tty, ch);
		return;
	}
	if (was_stopped)
		start_tty(tty);
	tty->driver->write(tty, &ch, 1);
	if (was_stopped)
		stop_tty(tty);
}

int n_tty_ioctl(struct tty_struct * tty, struct file * file,
		       unsigned int cmd, unsigned long arg)
{
	struct tty_struct * real_tty;
	void __user *p = (void __user *)arg;
	int retval;
	struct tty_ldisc *ld;

	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
	    tty->driver->subtype == PTY_TYPE_MASTER)
		real_tty = tty->link;
	else
		real_tty = tty;

	switch (cmd) {
#ifdef TIOCGETP
		case TIOCGETP:
			return get_sgttyb(real_tty, (struct sgttyb __user *) arg);
		case TIOCSETP:
		case TIOCSETN:
			return set_sgttyb(real_tty, (struct sgttyb __user *) arg);
#endif
#ifdef TIOCGETC
		case TIOCGETC:
			return get_tchars(real_tty, p);
		case TIOCSETC:
			return set_tchars(real_tty, p);
#endif
#ifdef TIOCGLTC
		case TIOCGLTC:
			return get_ltchars(real_tty, p);
		case TIOCSLTC:
			return set_ltchars(real_tty, p);
#endif
		case TCGETS:
			if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios))
				return -EFAULT;
			return 0;
		case TCSETSF:
			return set_termios(real_tty, p,  TERMIOS_FLUSH | TERMIOS_WAIT);
		case TCSETSW:
			return set_termios(real_tty, p, TERMIOS_WAIT);
		case TCSETS:
			return set_termios(real_tty, p, 0);
		case TCGETA:
			return get_termio(real_tty, p);
		case TCSETAF:
			return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_TERMIO);
		case TCSETAW:
			return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_TERMIO);
		case TCSETA:
			return set_termios(real_tty, p, TERMIOS_TERMIO);
		case TCXONC:
			retval = tty_check_change(tty);
			if (retval)
				return retval;
			switch (arg) {
			case TCOOFF:
				if (!tty->flow_stopped) {
					tty->flow_stopped = 1;
					stop_tty(tty);
				}
				break;
			case TCOON:
				if (tty->flow_stopped) {
					tty->flow_stopped = 0;
					start_tty(tty);
				}
				break;
			case TCIOFF:
				if (STOP_CHAR(tty) != __DISABLED_CHAR)
					send_prio_char(tty, STOP_CHAR(tty));
				break;
			case TCION:
				if (START_CHAR(tty) != __DISABLED_CHAR)
					send_prio_char(tty, START_CHAR(tty));
				break;
			default:
				return -EINVAL;
			}
			return 0;
		case TCFLSH:
			retval = tty_check_change(tty);
			if (retval)
				return retval;
				
			ld = tty_ldisc_ref(tty);
			switch (arg) {
			case TCIFLUSH:
				if (ld && ld->flush_buffer)
					ld->flush_buffer(tty);
				break;
			case TCIOFLUSH:
				if (ld && ld->flush_buffer)
					ld->flush_buffer(tty);
				/* fall through */
			case TCOFLUSH:
				if (tty->driver->flush_buffer)
					tty->driver->flush_buffer(tty);
				break;
			default:
				tty_ldisc_deref(ld);
				return -EINVAL;
			}
			tty_ldisc_deref(ld);
			return 0;
		case TIOCOUTQ:
			return put_user(tty->driver->chars_in_buffer ?
					tty->driver->chars_in_buffer(tty) : 0,
					(int __user *) arg);
		case TIOCINQ:
			retval = tty->read_cnt;
			if (L_ICANON(tty))
				retval = inq_canon(tty);
			return put_user(retval, (unsigned int __user *) arg);
		case TIOCGLCKTRMIOS:
			if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios_locked))
				return -EFAULT;
			return 0;

		case TIOCSLCKTRMIOS:
			if (!capable(CAP_SYS_ADMIN))
				return -EPERM;
			if (user_termios_to_kernel_termios(real_tty->termios_locked, (struct termios __user *) arg))
				return -EFAULT;
			return 0;

		case TIOCPKT:
		{
			int pktmode;

			if (tty->driver->type != TTY_DRIVER_TYPE_PTY ||
			    tty->driver->subtype != PTY_TYPE_MASTER)
				return -ENOTTY;
			if (get_user(pktmode, (int __user *) arg))
				return -EFAULT;
			if (pktmode) {
				if (!tty->packet) {
					tty->packet = 1;
					tty->link->ctrl_status = 0;
				}
			} else
				tty->packet = 0;
			return 0;
		}
		case TIOCGSOFTCAR:
			return put_user(C_CLOCAL(tty) ? 1 : 0, (int __user *)arg);
		case TIOCSSOFTCAR:
			if (get_user(arg, (unsigned int __user *) arg))
				return -EFAULT;
			down(&tty->termios_sem);
			tty->termios->c_cflag =
				((tty->termios->c_cflag & ~CLOCAL) |
				 (arg ? CLOCAL : 0));
			up(&tty->termios_sem);
			return 0;
		default:
			return -ENOIOCTLCMD;
		}
}

EXPORT_SYMBOL(n_tty_ioctl);