blob: 973be2f441951ed0e68d658c1192c94524f33aff [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * n_tty.c --- implements the N_TTY line discipline.
Alan Cox4edf1822008-02-08 04:18:44 -08003 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 * This code used to be in tty_io.c, but things are getting hairy
5 * enough that it made sense to split things off. (The N_TTY
6 * processing has changed so much that it's hardly recognizable,
7 * anyway...)
8 *
9 * Note that the open routine for N_TTY is guaranteed never to return
10 * an error. This is because Linux will fall back to setting a line
Alan Cox4edf1822008-02-08 04:18:44 -080011 * to N_TTY if it can not switch to any other line discipline.
Linus Torvalds1da177e2005-04-16 15:20:36 -070012 *
13 * Written by Theodore Ts'o, Copyright 1994.
Alan Cox4edf1822008-02-08 04:18:44 -080014 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070015 * This file also contains code originally written by Linus Torvalds,
16 * Copyright 1991, 1992, 1993, and by Julian Cowley, Copyright 1994.
Alan Cox4edf1822008-02-08 04:18:44 -080017 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070018 * This file may be redistributed under the terms of the GNU General Public
19 * License.
20 *
21 * Reduced memory usage for older ARM systems - Russell King.
22 *
Alan Cox4edf1822008-02-08 04:18:44 -080023 * 2000/01/20 Fixed SMP locking on put_tty_queue using bits of
Linus Torvalds1da177e2005-04-16 15:20:36 -070024 * the patch by Andrew J. Kroll <ag784@freenet.buffalo.edu>
25 * who actually finally proved there really was a race.
26 *
27 * 2002/03/18 Implemented n_tty_wakeup to send SIGIO POLL_OUTs to
28 * waiting writing processes-Sapan Bhatia <sapan@corewars.org>.
Alan Cox11a96d12008-10-13 10:46:24 +010029 * Also fixed a bug in BLOCKING mode where n_tty_write returns
Linus Torvalds1da177e2005-04-16 15:20:36 -070030 * EAGAIN
31 */
32
33#include <linux/types.h>
34#include <linux/major.h>
35#include <linux/errno.h>
36#include <linux/signal.h>
37#include <linux/fcntl.h>
38#include <linux/sched.h>
39#include <linux/interrupt.h>
40#include <linux/tty.h>
41#include <linux/timer.h>
42#include <linux/ctype.h>
43#include <linux/mm.h>
44#include <linux/string.h>
45#include <linux/slab.h>
46#include <linux/poll.h>
47#include <linux/bitops.h>
Miloslav Trmac522ed772007-07-15 23:40:56 -070048#include <linux/audit.h>
49#include <linux/file.h>
Alan Cox300a6202009-01-02 13:41:04 +000050#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070051
Linus Torvalds1da177e2005-04-16 15:20:36 -070052#include <asm/system.h>
53
54/* number of characters left in xmit buffer before select has we have room */
55#define WAKEUP_CHARS 256
56
57/*
58 * This defines the low- and high-watermarks for throttling and
59 * unthrottling the TTY driver. These watermarks are used for
60 * controlling the space in the read buffer.
61 */
62#define TTY_THRESHOLD_THROTTLE 128 /* now based on remaining room */
63#define TTY_THRESHOLD_UNTHROTTLE 128
64
Joe Petersona88a69c2009-01-02 13:40:53 +000065/*
66 * Special byte codes used in the echo buffer to represent operations
67 * or special handling of characters. Bytes in the echo buffer that
68 * are not part of such special blocks are treated as normal character
69 * codes.
70 */
71#define ECHO_OP_START 0xff
72#define ECHO_OP_MOVE_BACK_COL 0x80
73#define ECHO_OP_SET_CANON_COL 0x81
74#define ECHO_OP_ERASE_TAB 0x82
75
Miloslav Trmac522ed772007-07-15 23:40:56 -070076static inline int tty_put_user(struct tty_struct *tty, unsigned char x,
77 unsigned char __user *ptr)
78{
79 tty_audit_add_data(tty, &x, 1);
80 return put_user(x, ptr);
81}
82
Alan Cox33f0f882006-01-09 20:54:13 -080083/**
84 * n_tty_set__room - receive space
85 * @tty: terminal
86 *
87 * Called by the driver to find out how much data it is
88 * permitted to feed to the line discipline without any being lost
89 * and thus to manage flow control. Not serialized. Answers for the
90 * "instant".
91 */
92
93static void n_tty_set_room(struct tty_struct *tty)
94{
Alan Cox17b82062008-10-13 10:45:06 +010095 /* tty->read_cnt is not read locked ? */
Alan Cox33f0f882006-01-09 20:54:13 -080096 int left = N_TTY_BUF_SIZE - tty->read_cnt - 1;
97
98 /*
99 * If we are doing input canonicalization, and there are no
100 * pending newlines, let characters through without limit, so
101 * that erase characters will be handled. Other excess
102 * characters will be beeped.
103 */
104 if (left <= 0)
105 left = tty->icanon && !tty->canon_data;
106 tty->receive_room = left;
107}
108
109static void put_tty_queue_nolock(unsigned char c, struct tty_struct *tty)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700110{
111 if (tty->read_cnt < N_TTY_BUF_SIZE) {
112 tty->read_buf[tty->read_head] = c;
113 tty->read_head = (tty->read_head + 1) & (N_TTY_BUF_SIZE-1);
114 tty->read_cnt++;
115 }
116}
117
Alan Cox17b82062008-10-13 10:45:06 +0100118/**
119 * put_tty_queue - add character to tty
120 * @c: character
121 * @tty: tty device
122 *
123 * Add a character to the tty read_buf queue. This is done under the
124 * read_lock to serialize character addition and also to protect us
125 * against parallel reads or flushes
126 */
127
Alan Cox33f0f882006-01-09 20:54:13 -0800128static void put_tty_queue(unsigned char c, struct tty_struct *tty)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129{
130 unsigned long flags;
131 /*
132 * The problem of stomping on the buffers ends here.
133 * Why didn't anyone see this one coming? --AJK
134 */
135 spin_lock_irqsave(&tty->read_lock, flags);
136 put_tty_queue_nolock(c, tty);
137 spin_unlock_irqrestore(&tty->read_lock, flags);
138}
139
140/**
141 * check_unthrottle - allow new receive data
142 * @tty; tty device
143 *
Alan Cox17b82062008-10-13 10:45:06 +0100144 * Check whether to call the driver unthrottle functions
145 *
Ingo Molnar70522e12006-03-23 03:00:31 -0800146 * Can sleep, may be called under the atomic_read_lock mutex but
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 * this is not guaranteed.
148 */
Alan Cox4edf1822008-02-08 04:18:44 -0800149static void check_unthrottle(struct tty_struct *tty)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150{
Alan Cox39c2e602008-04-30 00:54:18 -0700151 if (tty->count)
152 tty_unthrottle(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153}
154
155/**
156 * reset_buffer_flags - reset buffer state
157 * @tty: terminal to reset
158 *
Alan Cox4edf1822008-02-08 04:18:44 -0800159 * Reset the read buffer counters, clear the flags,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 * and make sure the driver is unthrottled. Called
161 * from n_tty_open() and n_tty_flush_buffer().
Alan Cox17b82062008-10-13 10:45:06 +0100162 *
163 * Locking: tty_read_lock for read fields.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 */
Joe Petersona88a69c2009-01-02 13:40:53 +0000165
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166static void reset_buffer_flags(struct tty_struct *tty)
167{
168 unsigned long flags;
169
170 spin_lock_irqsave(&tty->read_lock, flags);
171 tty->read_head = tty->read_tail = tty->read_cnt = 0;
172 spin_unlock_irqrestore(&tty->read_lock, flags);
Joe Petersona88a69c2009-01-02 13:40:53 +0000173
174 mutex_lock(&tty->echo_lock);
175 tty->echo_pos = tty->echo_cnt = tty->echo_overrun = 0;
176 mutex_unlock(&tty->echo_lock);
177
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 tty->canon_head = tty->canon_data = tty->erasing = 0;
179 memset(&tty->read_flags, 0, sizeof tty->read_flags);
Alan Cox33f0f882006-01-09 20:54:13 -0800180 n_tty_set_room(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 check_unthrottle(tty);
182}
183
184/**
185 * n_tty_flush_buffer - clean input queue
186 * @tty: terminal device
187 *
188 * Flush the input buffer. Called when the line discipline is
189 * being closed, when the tty layer wants the buffer flushed (eg
190 * at hangup) or when the N_TTY line discipline internally has to
191 * clean the pending queue (for example some signals).
192 *
Alan Cox17b82062008-10-13 10:45:06 +0100193 * Locking: ctrl_lock, read_lock.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194 */
Alan Cox4edf1822008-02-08 04:18:44 -0800195
196static void n_tty_flush_buffer(struct tty_struct *tty)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197{
Alan Cox04f378b2008-04-30 00:53:29 -0700198 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 /* clear everything and unthrottle the driver */
200 reset_buffer_flags(tty);
Alan Cox4edf1822008-02-08 04:18:44 -0800201
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 if (!tty->link)
203 return;
204
Alan Cox04f378b2008-04-30 00:53:29 -0700205 spin_lock_irqsave(&tty->ctrl_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 if (tty->link->packet) {
207 tty->ctrl_status |= TIOCPKT_FLUSHREAD;
208 wake_up_interruptible(&tty->link->read_wait);
209 }
Alan Cox04f378b2008-04-30 00:53:29 -0700210 spin_unlock_irqrestore(&tty->ctrl_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211}
212
213/**
214 * n_tty_chars_in_buffer - report available bytes
215 * @tty: tty device
216 *
217 * Report the number of characters buffered to be delivered to user
Alan Cox4edf1822008-02-08 04:18:44 -0800218 * at this instant in time.
Alan Cox17b82062008-10-13 10:45:06 +0100219 *
220 * Locking: read_lock
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 */
Alan Cox4edf1822008-02-08 04:18:44 -0800222
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223static ssize_t n_tty_chars_in_buffer(struct tty_struct *tty)
224{
225 unsigned long flags;
226 ssize_t n = 0;
227
228 spin_lock_irqsave(&tty->read_lock, flags);
229 if (!tty->icanon) {
230 n = tty->read_cnt;
231 } else if (tty->canon_data) {
232 n = (tty->canon_head > tty->read_tail) ?
233 tty->canon_head - tty->read_tail :
234 tty->canon_head + (N_TTY_BUF_SIZE - tty->read_tail);
235 }
236 spin_unlock_irqrestore(&tty->read_lock, flags);
237 return n;
238}
239
240/**
241 * is_utf8_continuation - utf8 multibyte check
242 * @c: byte to check
243 *
244 * Returns true if the utf8 character 'c' is a multibyte continuation
245 * character. We use this to correctly compute the on screen size
246 * of the character when printing
247 */
Alan Cox4edf1822008-02-08 04:18:44 -0800248
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249static inline int is_utf8_continuation(unsigned char c)
250{
251 return (c & 0xc0) == 0x80;
252}
253
254/**
255 * is_continuation - multibyte check
256 * @c: byte to check
257 *
258 * Returns true if the utf8 character 'c' is a multibyte continuation
259 * character and the terminal is in unicode mode.
260 */
Alan Cox4edf1822008-02-08 04:18:44 -0800261
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262static inline int is_continuation(unsigned char c, struct tty_struct *tty)
263{
264 return I_IUTF8(tty) && is_utf8_continuation(c);
265}
266
267/**
Joe Petersona88a69c2009-01-02 13:40:53 +0000268 * do_output_char - output one character
269 * @c: character (or partial unicode symbol)
270 * @tty: terminal device
271 * @space: space available in tty driver write buffer
272 *
273 * This is a helper function that handles one output character
274 * (including special characters like TAB, CR, LF, etc.),
275 * putting the results in the tty driver's write buffer.
276 *
277 * Note that Linux currently ignores TABDLY, CRDLY, VTDLY, FFDLY
278 * and NLDLY. They simply aren't relevant in the world today.
279 * If you ever need them, add them here.
280 *
281 * Returns the number of bytes of buffer space used or -1 if
282 * no space left.
283 *
284 * Locking: should be called under the output_lock to protect
285 * the column state and space left in the buffer
286 */
287
288static int do_output_char(unsigned char c, struct tty_struct *tty, int space)
289{
290 int spaces;
291
292 if (!space)
293 return -1;
Alan Cox300a6202009-01-02 13:41:04 +0000294
Joe Petersona88a69c2009-01-02 13:40:53 +0000295 switch (c) {
296 case '\n':
297 if (O_ONLRET(tty))
298 tty->column = 0;
299 if (O_ONLCR(tty)) {
300 if (space < 2)
301 return -1;
302 tty->canon_column = tty->column = 0;
303 tty_put_char(tty, '\r');
304 tty_put_char(tty, c);
305 return 2;
306 }
307 tty->canon_column = tty->column;
308 break;
309 case '\r':
310 if (O_ONOCR(tty) && tty->column == 0)
311 return 0;
312 if (O_OCRNL(tty)) {
313 c = '\n';
314 if (O_ONLRET(tty))
315 tty->canon_column = tty->column = 0;
316 break;
317 }
318 tty->canon_column = tty->column = 0;
319 break;
320 case '\t':
321 spaces = 8 - (tty->column & 7);
322 if (O_TABDLY(tty) == XTABS) {
323 if (space < spaces)
324 return -1;
325 tty->column += spaces;
326 tty->ops->write(tty, " ", spaces);
327 return spaces;
328 }
329 tty->column += spaces;
330 break;
331 case '\b':
332 if (tty->column > 0)
333 tty->column--;
334 break;
335 default:
Joe Petersona59c0d62009-01-02 13:43:25 +0000336 if (!iscntrl(c)) {
337 if (O_OLCUC(tty))
338 c = toupper(c);
339 if (!is_continuation(c, tty))
340 tty->column++;
341 }
Joe Petersona88a69c2009-01-02 13:40:53 +0000342 break;
343 }
344
345 tty_put_char(tty, c);
346 return 1;
347}
348
349/**
350 * process_output - output post processor
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 * @c: character (or partial unicode symbol)
352 * @tty: terminal device
353 *
354 * Perform OPOST processing. Returns -1 when the output device is
Joe Petersona88a69c2009-01-02 13:40:53 +0000355 * full and the character must be retried.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356 *
Joe Petersona88a69c2009-01-02 13:40:53 +0000357 * Locking: output_lock to protect column state and space left
358 * (also, this is called from n_tty_write under the
359 * tty layer write lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 */
Alan Cox4edf1822008-02-08 04:18:44 -0800361
Joe Petersona88a69c2009-01-02 13:40:53 +0000362static int process_output(unsigned char c, struct tty_struct *tty)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363{
Joe Petersona88a69c2009-01-02 13:40:53 +0000364 int space, retval;
365
366 mutex_lock(&tty->output_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367
Alan Coxf34d7a52008-04-30 00:54:13 -0700368 space = tty_write_room(tty);
Joe Petersona88a69c2009-01-02 13:40:53 +0000369 retval = do_output_char(c, tty, space);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370
Joe Petersona88a69c2009-01-02 13:40:53 +0000371 mutex_unlock(&tty->output_lock);
372 if (retval < 0)
373 return -1;
374 else
375 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376}
377
378/**
Joe Petersona88a69c2009-01-02 13:40:53 +0000379 * process_output_block - block post processor
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 * @tty: terminal device
381 * @inbuf: user buffer
382 * @nr: number of bytes
383 *
384 * This path is used to speed up block console writes, among other
385 * things when processing blocks of output data. It handles only
386 * the simple cases normally found and helps to generate blocks of
387 * symbols for the console driver and thus improve performance.
388 *
Joe Petersona88a69c2009-01-02 13:40:53 +0000389 * Locking: output_lock to protect column state and space left
390 * (also, this is called from n_tty_write under the
391 * tty layer write lock)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 */
Alan Cox4edf1822008-02-08 04:18:44 -0800393
Joe Petersona88a69c2009-01-02 13:40:53 +0000394static ssize_t process_output_block(struct tty_struct *tty,
395 const unsigned char *buf, unsigned int nr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396{
397 int space;
398 int i;
399 const unsigned char *cp;
400
Joe Petersona88a69c2009-01-02 13:40:53 +0000401 mutex_lock(&tty->output_lock);
402
Alan Coxf34d7a52008-04-30 00:54:13 -0700403 space = tty_write_room(tty);
Alan Cox300a6202009-01-02 13:41:04 +0000404 if (!space) {
Joe Petersona88a69c2009-01-02 13:40:53 +0000405 mutex_unlock(&tty->output_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 return 0;
Joe Petersona88a69c2009-01-02 13:40:53 +0000407 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408 if (nr > space)
409 nr = space;
410
411 for (i = 0, cp = buf; i < nr; i++, cp++) {
Joe Petersona59c0d62009-01-02 13:43:25 +0000412 unsigned char c = *cp;
413
414 switch (c) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415 case '\n':
416 if (O_ONLRET(tty))
417 tty->column = 0;
418 if (O_ONLCR(tty))
419 goto break_out;
420 tty->canon_column = tty->column;
421 break;
422 case '\r':
423 if (O_ONOCR(tty) && tty->column == 0)
424 goto break_out;
425 if (O_OCRNL(tty))
426 goto break_out;
427 tty->canon_column = tty->column = 0;
428 break;
429 case '\t':
430 goto break_out;
431 case '\b':
432 if (tty->column > 0)
433 tty->column--;
434 break;
435 default:
Joe Petersona59c0d62009-01-02 13:43:25 +0000436 if (!iscntrl(c)) {
437 if (O_OLCUC(tty))
438 goto break_out;
439 if (!is_continuation(c, tty))
440 tty->column++;
441 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442 break;
443 }
444 }
445break_out:
Alan Coxf34d7a52008-04-30 00:54:13 -0700446 i = tty->ops->write(tty, buf, i);
Joe Petersona88a69c2009-01-02 13:40:53 +0000447
448 mutex_unlock(&tty->output_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 return i;
450}
451
Joe Petersona88a69c2009-01-02 13:40:53 +0000452/**
453 * process_echoes - write pending echo characters
454 * @tty: terminal device
455 *
456 * Write previously buffered echo (and other ldisc-generated)
457 * characters to the tty.
458 *
459 * Characters generated by the ldisc (including echoes) need to
460 * be buffered because the driver's write buffer can fill during
461 * heavy program output. Echoing straight to the driver will
462 * often fail under these conditions, causing lost characters and
463 * resulting mismatches of ldisc state information.
464 *
465 * Since the ldisc state must represent the characters actually sent
466 * to the driver at the time of the write, operations like certain
467 * changes in column state are also saved in the buffer and executed
468 * here.
469 *
470 * A circular fifo buffer is used so that the most recent characters
471 * are prioritized. Also, when control characters are echoed with a
472 * prefixed "^", the pair is treated atomically and thus not separated.
473 *
474 * Locking: output_lock to protect column state and space left,
475 * echo_lock to protect the echo buffer
476 */
477
478static void process_echoes(struct tty_struct *tty)
479{
480 int space, nr;
481 unsigned char c;
482 unsigned char *cp, *buf_end;
483
484 if (!tty->echo_cnt)
485 return;
486
487 mutex_lock(&tty->output_lock);
488 mutex_lock(&tty->echo_lock);
489
490 space = tty_write_room(tty);
491
492 buf_end = tty->echo_buf + N_TTY_BUF_SIZE;
493 cp = tty->echo_buf + tty->echo_pos;
494 nr = tty->echo_cnt;
495 while (nr > 0) {
496 c = *cp;
497 if (c == ECHO_OP_START) {
498 unsigned char op;
499 unsigned char *opp;
500 int no_space_left = 0;
501
502 /*
503 * If the buffer byte is the start of a multi-byte
504 * operation, get the next byte, which is either the
505 * op code or a control character value.
506 */
507 opp = cp + 1;
508 if (opp == buf_end)
509 opp -= N_TTY_BUF_SIZE;
510 op = *opp;
Alan Cox300a6202009-01-02 13:41:04 +0000511
Joe Petersona88a69c2009-01-02 13:40:53 +0000512 switch (op) {
513 unsigned int num_chars, num_bs;
514
515 case ECHO_OP_ERASE_TAB:
516 if (++opp == buf_end)
517 opp -= N_TTY_BUF_SIZE;
518 num_chars = *opp;
519
520 /*
521 * Determine how many columns to go back
522 * in order to erase the tab.
523 * This depends on the number of columns
524 * used by other characters within the tab
525 * area. If this (modulo 8) count is from
526 * the start of input rather than from a
527 * previous tab, we offset by canon column.
528 * Otherwise, tab spacing is normal.
529 */
530 if (!(num_chars & 0x80))
531 num_chars += tty->canon_column;
532 num_bs = 8 - (num_chars & 7);
533
534 if (num_bs > space) {
535 no_space_left = 1;
536 break;
537 }
538 space -= num_bs;
539 while (num_bs--) {
540 tty_put_char(tty, '\b');
541 if (tty->column > 0)
542 tty->column--;
543 }
544 cp += 3;
545 nr -= 3;
546 break;
547
548 case ECHO_OP_SET_CANON_COL:
549 tty->canon_column = tty->column;
550 cp += 2;
551 nr -= 2;
552 break;
553
554 case ECHO_OP_MOVE_BACK_COL:
555 if (tty->column > 0)
556 tty->column--;
557 cp += 2;
558 nr -= 2;
559 break;
560
561 case ECHO_OP_START:
562 /* This is an escaped echo op start code */
563 if (!space) {
564 no_space_left = 1;
565 break;
566 }
567 tty_put_char(tty, ECHO_OP_START);
568 tty->column++;
569 space--;
570 cp += 2;
571 nr -= 2;
572 break;
573
574 default:
575 if (iscntrl(op)) {
576 if (L_ECHOCTL(tty)) {
577 /*
578 * Ensure there is enough space
579 * for the whole ctrl pair.
580 */
581 if (space < 2) {
582 no_space_left = 1;
583 break;
584 }
585 tty_put_char(tty, '^');
586 tty_put_char(tty, op ^ 0100);
587 tty->column += 2;
588 space -= 2;
589 } else {
590 if (!space) {
591 no_space_left = 1;
592 break;
593 }
594 tty_put_char(tty, op);
595 space--;
596 }
597 }
598 /*
599 * If above falls through, this was an
600 * undefined op.
601 */
602 cp += 2;
603 nr -= 2;
604 }
605
606 if (no_space_left)
607 break;
608 } else {
609 int retval;
610
Alan Cox300a6202009-01-02 13:41:04 +0000611 retval = do_output_char(c, tty, space);
612 if (retval < 0)
Joe Petersona88a69c2009-01-02 13:40:53 +0000613 break;
614 space -= retval;
615 cp += 1;
616 nr -= 1;
617 }
618
619 /* When end of circular buffer reached, wrap around */
620 if (cp >= buf_end)
621 cp -= N_TTY_BUF_SIZE;
622 }
623
624 if (nr == 0) {
625 tty->echo_pos = 0;
626 tty->echo_cnt = 0;
627 tty->echo_overrun = 0;
628 } else {
629 int num_processed = tty->echo_cnt - nr;
630 tty->echo_pos += num_processed;
631 tty->echo_pos &= N_TTY_BUF_SIZE - 1;
632 tty->echo_cnt = nr;
633 if (num_processed > 0)
634 tty->echo_overrun = 0;
635 }
636
637 mutex_unlock(&tty->echo_lock);
638 mutex_unlock(&tty->output_lock);
639
640 if (tty->ops->flush_chars)
641 tty->ops->flush_chars(tty);
642}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643
644/**
Joe Petersona88a69c2009-01-02 13:40:53 +0000645 * add_echo_byte - add a byte to the echo buffer
646 * @c: unicode byte to echo
647 * @tty: terminal device
648 *
649 * Add a character or operation byte to the echo buffer.
650 *
651 * Should be called under the echo lock to protect the echo buffer.
652 */
653
654static void add_echo_byte(unsigned char c, struct tty_struct *tty)
655{
656 int new_byte_pos;
657
658 if (tty->echo_cnt == N_TTY_BUF_SIZE) {
659 /* Circular buffer is already at capacity */
660 new_byte_pos = tty->echo_pos;
661
662 /*
663 * Since the buffer start position needs to be advanced,
664 * be sure to step by a whole operation byte group.
665 */
Alan Cox300a6202009-01-02 13:41:04 +0000666 if (tty->echo_buf[tty->echo_pos] == ECHO_OP_START) {
Joe Petersona88a69c2009-01-02 13:40:53 +0000667 if (tty->echo_buf[(tty->echo_pos + 1) &
668 (N_TTY_BUF_SIZE - 1)] ==
669 ECHO_OP_ERASE_TAB) {
670 tty->echo_pos += 3;
671 tty->echo_cnt -= 2;
672 } else {
673 tty->echo_pos += 2;
674 tty->echo_cnt -= 1;
675 }
676 } else {
677 tty->echo_pos++;
678 }
679 tty->echo_pos &= N_TTY_BUF_SIZE - 1;
680
681 tty->echo_overrun = 1;
682 } else {
683 new_byte_pos = tty->echo_pos + tty->echo_cnt;
684 new_byte_pos &= N_TTY_BUF_SIZE - 1;
685 tty->echo_cnt++;
686 }
687
688 tty->echo_buf[new_byte_pos] = c;
689}
690
691/**
692 * echo_move_back_col - add operation to move back a column
693 * @tty: terminal device
694 *
695 * Add an operation to the echo buffer to move back one column.
696 *
697 * Locking: echo_lock to protect the echo buffer
698 */
699
700static void echo_move_back_col(struct tty_struct *tty)
701{
702 mutex_lock(&tty->echo_lock);
703
704 add_echo_byte(ECHO_OP_START, tty);
705 add_echo_byte(ECHO_OP_MOVE_BACK_COL, tty);
706
707 mutex_unlock(&tty->echo_lock);
708}
709
710/**
711 * echo_set_canon_col - add operation to set the canon column
712 * @tty: terminal device
713 *
714 * Add an operation to the echo buffer to set the canon column
715 * to the current column.
716 *
717 * Locking: echo_lock to protect the echo buffer
718 */
719
720static void echo_set_canon_col(struct tty_struct *tty)
721{
722 mutex_lock(&tty->echo_lock);
723
724 add_echo_byte(ECHO_OP_START, tty);
725 add_echo_byte(ECHO_OP_SET_CANON_COL, tty);
726
727 mutex_unlock(&tty->echo_lock);
728}
729
730/**
731 * echo_erase_tab - add operation to erase a tab
732 * @num_chars: number of character columns already used
733 * @after_tab: true if num_chars starts after a previous tab
734 * @tty: terminal device
735 *
736 * Add an operation to the echo buffer to erase a tab.
737 *
738 * Called by the eraser function, which knows how many character
739 * columns have been used since either a previous tab or the start
740 * of input. This information will be used later, along with
741 * canon column (if applicable), to go back the correct number
742 * of columns.
743 *
744 * Locking: echo_lock to protect the echo buffer
745 */
746
747static void echo_erase_tab(unsigned int num_chars, int after_tab,
748 struct tty_struct *tty)
749{
750 mutex_lock(&tty->echo_lock);
751
752 add_echo_byte(ECHO_OP_START, tty);
753 add_echo_byte(ECHO_OP_ERASE_TAB, tty);
754
755 /* We only need to know this modulo 8 (tab spacing) */
756 num_chars &= 7;
757
758 /* Set the high bit as a flag if num_chars is after a previous tab */
759 if (after_tab)
760 num_chars |= 0x80;
Alan Cox300a6202009-01-02 13:41:04 +0000761
Joe Petersona88a69c2009-01-02 13:40:53 +0000762 add_echo_byte(num_chars, tty);
763
764 mutex_unlock(&tty->echo_lock);
765}
766
767/**
768 * echo_char_raw - echo a character raw
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769 * @c: unicode byte to echo
770 * @tty: terminal device
771 *
Alan Cox4edf1822008-02-08 04:18:44 -0800772 * Echo user input back onto the screen. This must be called only when
Linus Torvalds1da177e2005-04-16 15:20:36 -0700773 * L_ECHO(tty) is true. Called from the driver receive_buf path.
Alan Cox17b82062008-10-13 10:45:06 +0100774 *
Joe Petersona88a69c2009-01-02 13:40:53 +0000775 * This variant does not treat control characters specially.
776 *
777 * Locking: echo_lock to protect the echo buffer
778 */
779
780static void echo_char_raw(unsigned char c, struct tty_struct *tty)
781{
782 mutex_lock(&tty->echo_lock);
783
784 if (c == ECHO_OP_START) {
785 add_echo_byte(ECHO_OP_START, tty);
786 add_echo_byte(ECHO_OP_START, tty);
787 } else {
788 add_echo_byte(c, tty);
789 }
790
791 mutex_unlock(&tty->echo_lock);
792}
793
794/**
795 * echo_char - echo a character
796 * @c: unicode byte to echo
797 * @tty: terminal device
798 *
799 * Echo user input back onto the screen. This must be called only when
800 * L_ECHO(tty) is true. Called from the driver receive_buf path.
801 *
802 * This variant tags control characters to be possibly echoed as
803 * as "^X" (where X is the letter representing the control char).
804 *
805 * Locking: echo_lock to protect the echo buffer
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806 */
807
808static void echo_char(unsigned char c, struct tty_struct *tty)
809{
Joe Petersona88a69c2009-01-02 13:40:53 +0000810 mutex_lock(&tty->echo_lock);
811
812 if (c == ECHO_OP_START) {
813 add_echo_byte(ECHO_OP_START, tty);
814 add_echo_byte(ECHO_OP_START, tty);
815 } else {
816 if (iscntrl(c) && c != '\t')
817 add_echo_byte(ECHO_OP_START, tty);
818 add_echo_byte(c, tty);
819 }
820
821 mutex_unlock(&tty->echo_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700822}
823
Alan Cox17b82062008-10-13 10:45:06 +0100824/**
Joe Petersona88a69c2009-01-02 13:40:53 +0000825 * finish_erasing - complete erase
Alan Cox17b82062008-10-13 10:45:06 +0100826 * @tty: tty doing the erase
Alan Cox17b82062008-10-13 10:45:06 +0100827 */
Joe Petersona88a69c2009-01-02 13:40:53 +0000828
Linus Torvalds1da177e2005-04-16 15:20:36 -0700829static inline void finish_erasing(struct tty_struct *tty)
830{
831 if (tty->erasing) {
Joe Petersona88a69c2009-01-02 13:40:53 +0000832 echo_char_raw('/', tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700833 tty->erasing = 0;
834 }
835}
836
837/**
838 * eraser - handle erase function
839 * @c: character input
840 * @tty: terminal device
841 *
Robert P. J. Day3a4fa0a2007-10-19 23:10:43 +0200842 * Perform erase and necessary output when an erase character is
Linus Torvalds1da177e2005-04-16 15:20:36 -0700843 * present in the stream from the driver layer. Handles the complexities
844 * of UTF-8 multibyte symbols.
Alan Cox17b82062008-10-13 10:45:06 +0100845 *
Joe Petersona88a69c2009-01-02 13:40:53 +0000846 * Locking: read_lock for tty buffers
Linus Torvalds1da177e2005-04-16 15:20:36 -0700847 */
Alan Cox4edf1822008-02-08 04:18:44 -0800848
Linus Torvalds1da177e2005-04-16 15:20:36 -0700849static void eraser(unsigned char c, struct tty_struct *tty)
850{
851 enum { ERASE, WERASE, KILL } kill_type;
852 int head, seen_alnums, cnt;
853 unsigned long flags;
854
Alan Cox17b82062008-10-13 10:45:06 +0100855 /* FIXME: locking needed ? */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856 if (tty->read_head == tty->canon_head) {
Joe Peterson7e94b1d2009-01-02 13:43:40 +0000857 /* process_output('\a', tty); */ /* what do you think? */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700858 return;
859 }
860 if (c == ERASE_CHAR(tty))
861 kill_type = ERASE;
862 else if (c == WERASE_CHAR(tty))
863 kill_type = WERASE;
864 else {
865 if (!L_ECHO(tty)) {
866 spin_lock_irqsave(&tty->read_lock, flags);
867 tty->read_cnt -= ((tty->read_head - tty->canon_head) &
868 (N_TTY_BUF_SIZE - 1));
869 tty->read_head = tty->canon_head;
870 spin_unlock_irqrestore(&tty->read_lock, flags);
871 return;
872 }
873 if (!L_ECHOK(tty) || !L_ECHOKE(tty) || !L_ECHOE(tty)) {
874 spin_lock_irqsave(&tty->read_lock, flags);
875 tty->read_cnt -= ((tty->read_head - tty->canon_head) &
876 (N_TTY_BUF_SIZE - 1));
877 tty->read_head = tty->canon_head;
878 spin_unlock_irqrestore(&tty->read_lock, flags);
879 finish_erasing(tty);
880 echo_char(KILL_CHAR(tty), tty);
881 /* Add a newline if ECHOK is on and ECHOKE is off. */
882 if (L_ECHOK(tty))
Joe Petersona88a69c2009-01-02 13:40:53 +0000883 echo_char_raw('\n', tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700884 return;
885 }
886 kill_type = KILL;
887 }
888
889 seen_alnums = 0;
Alan Cox17b82062008-10-13 10:45:06 +0100890 /* FIXME: Locking ?? */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700891 while (tty->read_head != tty->canon_head) {
892 head = tty->read_head;
893
894 /* erase a single possibly multibyte character */
895 do {
896 head = (head - 1) & (N_TTY_BUF_SIZE-1);
897 c = tty->read_buf[head];
898 } while (is_continuation(c, tty) && head != tty->canon_head);
899
900 /* do not partially erase */
901 if (is_continuation(c, tty))
902 break;
903
904 if (kill_type == WERASE) {
905 /* Equivalent to BSD's ALTWERASE. */
906 if (isalnum(c) || c == '_')
907 seen_alnums++;
908 else if (seen_alnums)
909 break;
910 }
911 cnt = (tty->read_head - head) & (N_TTY_BUF_SIZE-1);
912 spin_lock_irqsave(&tty->read_lock, flags);
913 tty->read_head = head;
914 tty->read_cnt -= cnt;
915 spin_unlock_irqrestore(&tty->read_lock, flags);
916 if (L_ECHO(tty)) {
917 if (L_ECHOPRT(tty)) {
918 if (!tty->erasing) {
Joe Petersona88a69c2009-01-02 13:40:53 +0000919 echo_char_raw('\\', tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700920 tty->erasing = 1;
921 }
922 /* if cnt > 1, output a multi-byte character */
923 echo_char(c, tty);
924 while (--cnt > 0) {
925 head = (head+1) & (N_TTY_BUF_SIZE-1);
Joe Petersona88a69c2009-01-02 13:40:53 +0000926 echo_char_raw(tty->read_buf[head], tty);
927 echo_move_back_col(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700928 }
929 } else if (kill_type == ERASE && !L_ECHOE(tty)) {
930 echo_char(ERASE_CHAR(tty), tty);
931 } else if (c == '\t') {
Joe Petersona88a69c2009-01-02 13:40:53 +0000932 unsigned int num_chars = 0;
933 int after_tab = 0;
934 unsigned long tail = tty->read_head;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700935
Joe Petersona88a69c2009-01-02 13:40:53 +0000936 /*
937 * Count the columns used for characters
938 * since the start of input or after a
939 * previous tab.
940 * This info is used to go back the correct
941 * number of columns.
942 */
943 while (tail != tty->canon_head) {
944 tail = (tail-1) & (N_TTY_BUF_SIZE-1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700945 c = tty->read_buf[tail];
Joe Petersona88a69c2009-01-02 13:40:53 +0000946 if (c == '\t') {
947 after_tab = 1;
948 break;
Alan Cox300a6202009-01-02 13:41:04 +0000949 } else if (iscntrl(c)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950 if (L_ECHOCTL(tty))
Joe Petersona88a69c2009-01-02 13:40:53 +0000951 num_chars += 2;
952 } else if (!is_continuation(c, tty)) {
953 num_chars++;
954 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955 }
Joe Petersona88a69c2009-01-02 13:40:53 +0000956 echo_erase_tab(num_chars, after_tab, tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700957 } else {
958 if (iscntrl(c) && L_ECHOCTL(tty)) {
Joe Petersona88a69c2009-01-02 13:40:53 +0000959 echo_char_raw('\b', tty);
960 echo_char_raw(' ', tty);
961 echo_char_raw('\b', tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962 }
963 if (!iscntrl(c) || L_ECHOCTL(tty)) {
Joe Petersona88a69c2009-01-02 13:40:53 +0000964 echo_char_raw('\b', tty);
965 echo_char_raw(' ', tty);
966 echo_char_raw('\b', tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967 }
968 }
969 }
970 if (kill_type == ERASE)
971 break;
972 }
Joe Petersona88a69c2009-01-02 13:40:53 +0000973 if (tty->read_head == tty->canon_head && L_ECHO(tty))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974 finish_erasing(tty);
975}
976
977/**
978 * isig - handle the ISIG optio
979 * @sig: signal
980 * @tty: terminal
981 * @flush: force flush
982 *
983 * Called when a signal is being sent due to terminal input. This
984 * may caus terminal flushing to take place according to the termios
985 * settings and character used. Called from the driver receive_buf
986 * path so serialized.
Alan Cox17b82062008-10-13 10:45:06 +0100987 *
988 * Locking: ctrl_lock, read_lock (both via flush buffer)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700989 */
Alan Cox4edf1822008-02-08 04:18:44 -0800990
Linus Torvalds1da177e2005-04-16 15:20:36 -0700991static inline void isig(int sig, struct tty_struct *tty, int flush)
992{
Eric W. Biedermanab521dc2007-02-12 00:53:00 -0800993 if (tty->pgrp)
994 kill_pgrp(tty->pgrp, sig, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700995 if (flush || !L_NOFLSH(tty)) {
996 n_tty_flush_buffer(tty);
Alan Coxf34d7a52008-04-30 00:54:13 -0700997 tty_driver_flush_buffer(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700998 }
999}
1000
1001/**
1002 * n_tty_receive_break - handle break
1003 * @tty: terminal
1004 *
1005 * An RS232 break event has been hit in the incoming bitstream. This
1006 * can cause a variety of events depending upon the termios settings.
1007 *
1008 * Called from the receive_buf path so single threaded.
1009 */
Alan Cox4edf1822008-02-08 04:18:44 -08001010
Linus Torvalds1da177e2005-04-16 15:20:36 -07001011static inline void n_tty_receive_break(struct tty_struct *tty)
1012{
1013 if (I_IGNBRK(tty))
1014 return;
1015 if (I_BRKINT(tty)) {
1016 isig(SIGINT, tty, 1);
1017 return;
1018 }
1019 if (I_PARMRK(tty)) {
1020 put_tty_queue('\377', tty);
1021 put_tty_queue('\0', tty);
1022 }
1023 put_tty_queue('\0', tty);
1024 wake_up_interruptible(&tty->read_wait);
1025}
1026
1027/**
1028 * n_tty_receive_overrun - handle overrun reporting
1029 * @tty: terminal
1030 *
1031 * Data arrived faster than we could process it. While the tty
1032 * driver has flagged this the bits that were missed are gone
1033 * forever.
1034 *
1035 * Called from the receive_buf path so single threaded. Does not
1036 * need locking as num_overrun and overrun_time are function
1037 * private.
1038 */
Alan Cox4edf1822008-02-08 04:18:44 -08001039
Linus Torvalds1da177e2005-04-16 15:20:36 -07001040static inline void n_tty_receive_overrun(struct tty_struct *tty)
1041{
1042 char buf[64];
1043
1044 tty->num_overrun++;
1045 if (time_before(tty->overrun_time, jiffies - HZ) ||
1046 time_after(tty->overrun_time, jiffies)) {
1047 printk(KERN_WARNING "%s: %d input overrun(s)\n",
1048 tty_name(tty, buf),
1049 tty->num_overrun);
1050 tty->overrun_time = jiffies;
1051 tty->num_overrun = 0;
1052 }
1053}
1054
1055/**
1056 * n_tty_receive_parity_error - error notifier
1057 * @tty: terminal device
1058 * @c: character
1059 *
1060 * Process a parity error and queue the right data to indicate
Robert P. J. Day3a4fa0a2007-10-19 23:10:43 +02001061 * the error case if necessary. Locking as per n_tty_receive_buf.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001062 */
1063static inline void n_tty_receive_parity_error(struct tty_struct *tty,
1064 unsigned char c)
1065{
Alan Cox4edf1822008-02-08 04:18:44 -08001066 if (I_IGNPAR(tty))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001067 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001068 if (I_PARMRK(tty)) {
1069 put_tty_queue('\377', tty);
1070 put_tty_queue('\0', tty);
1071 put_tty_queue(c, tty);
1072 } else if (I_INPCK(tty))
1073 put_tty_queue('\0', tty);
1074 else
1075 put_tty_queue(c, tty);
1076 wake_up_interruptible(&tty->read_wait);
1077}
1078
1079/**
1080 * n_tty_receive_char - perform processing
1081 * @tty: terminal device
1082 * @c: character
1083 *
1084 * Process an individual character of input received from the driver.
Alan Cox4edf1822008-02-08 04:18:44 -08001085 * This is serialized with respect to itself by the rules for the
Linus Torvalds1da177e2005-04-16 15:20:36 -07001086 * driver above.
1087 */
1088
1089static inline void n_tty_receive_char(struct tty_struct *tty, unsigned char c)
1090{
1091 unsigned long flags;
Joe Petersonacc71bb2009-01-02 13:43:32 +00001092 int parmrk;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001093
1094 if (tty->raw) {
1095 put_tty_queue(c, tty);
1096 return;
1097 }
Alan Cox4edf1822008-02-08 04:18:44 -08001098
Linus Torvalds1da177e2005-04-16 15:20:36 -07001099 if (I_ISTRIP(tty))
1100 c &= 0x7f;
1101 if (I_IUCLC(tty) && L_IEXTEN(tty))
Alan Cox300a6202009-01-02 13:41:04 +00001102 c = tolower(c);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001103
Joe Peterson54d2a372008-02-06 01:37:59 -08001104 if (tty->stopped && !tty->flow_stopped && I_IXON(tty) &&
Joe Petersona88a69c2009-01-02 13:40:53 +00001105 I_IXANY(tty) && c != START_CHAR(tty) && c != STOP_CHAR(tty) &&
1106 c != INTR_CHAR(tty) && c != QUIT_CHAR(tty) && c != SUSP_CHAR(tty)) {
Joe Peterson54d2a372008-02-06 01:37:59 -08001107 start_tty(tty);
Joe Petersona88a69c2009-01-02 13:40:53 +00001108 process_echoes(tty);
1109 }
Joe Peterson54d2a372008-02-06 01:37:59 -08001110
Linus Torvalds1da177e2005-04-16 15:20:36 -07001111 if (tty->closing) {
1112 if (I_IXON(tty)) {
Joe Petersona88a69c2009-01-02 13:40:53 +00001113 if (c == START_CHAR(tty)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001114 start_tty(tty);
Joe Petersona88a69c2009-01-02 13:40:53 +00001115 process_echoes(tty);
Alan Cox300a6202009-01-02 13:41:04 +00001116 } else if (c == STOP_CHAR(tty))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001117 stop_tty(tty);
1118 }
1119 return;
1120 }
1121
1122 /*
1123 * If the previous character was LNEXT, or we know that this
1124 * character is not one of the characters that we'll have to
1125 * handle specially, do shortcut processing to speed things
1126 * up.
1127 */
1128 if (!test_bit(c, tty->process_char_map) || tty->lnext) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001129 tty->lnext = 0;
Joe Petersonacc71bb2009-01-02 13:43:32 +00001130 parmrk = (c == (unsigned char) '\377' && I_PARMRK(tty)) ? 1 : 0;
1131 if (tty->read_cnt >= (N_TTY_BUF_SIZE - parmrk - 1)) {
1132 /* beep if no space */
Joe Peterson7e94b1d2009-01-02 13:43:40 +00001133 if (L_ECHO(tty))
1134 process_output('\a', tty);
Joe Petersonacc71bb2009-01-02 13:43:32 +00001135 return;
1136 }
1137 if (L_ECHO(tty)) {
1138 finish_erasing(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001139 /* Record the column of first canon char. */
1140 if (tty->canon_head == tty->read_head)
Joe Petersona88a69c2009-01-02 13:40:53 +00001141 echo_set_canon_col(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001142 echo_char(c, tty);
Joe Petersona88a69c2009-01-02 13:40:53 +00001143 process_echoes(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001144 }
Joe Petersonacc71bb2009-01-02 13:43:32 +00001145 if (parmrk)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001146 put_tty_queue(c, tty);
1147 put_tty_queue(c, tty);
1148 return;
1149 }
Alan Cox4edf1822008-02-08 04:18:44 -08001150
Linus Torvalds1da177e2005-04-16 15:20:36 -07001151 if (I_IXON(tty)) {
1152 if (c == START_CHAR(tty)) {
1153 start_tty(tty);
Joe Petersona88a69c2009-01-02 13:40:53 +00001154 process_echoes(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001155 return;
1156 }
1157 if (c == STOP_CHAR(tty)) {
1158 stop_tty(tty);
1159 return;
1160 }
1161 }
Joe Peterson575537b2008-04-30 00:53:30 -07001162
Linus Torvalds1da177e2005-04-16 15:20:36 -07001163 if (L_ISIG(tty)) {
1164 int signal;
1165 signal = SIGINT;
1166 if (c == INTR_CHAR(tty))
1167 goto send_signal;
1168 signal = SIGQUIT;
1169 if (c == QUIT_CHAR(tty))
1170 goto send_signal;
1171 signal = SIGTSTP;
1172 if (c == SUSP_CHAR(tty)) {
1173send_signal:
Joe Petersonec5b1152008-02-06 01:37:38 -08001174 /*
Joe Petersonec5b1152008-02-06 01:37:38 -08001175 * Note that we do not use isig() here because we want
1176 * the order to be:
1177 * 1) flush, 2) echo, 3) signal
1178 */
1179 if (!L_NOFLSH(tty)) {
1180 n_tty_flush_buffer(tty);
Alan Coxf34d7a52008-04-30 00:54:13 -07001181 tty_driver_flush_buffer(tty);
Joe Petersonec5b1152008-02-06 01:37:38 -08001182 }
Joe Petersona88a69c2009-01-02 13:40:53 +00001183 if (I_IXON(tty))
1184 start_tty(tty);
1185 if (L_ECHO(tty)) {
Joe Petersonec5b1152008-02-06 01:37:38 -08001186 echo_char(c, tty);
Joe Petersona88a69c2009-01-02 13:40:53 +00001187 process_echoes(tty);
1188 }
Joe Petersonec5b1152008-02-06 01:37:38 -08001189 if (tty->pgrp)
1190 kill_pgrp(tty->pgrp, signal, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001191 return;
1192 }
1193 }
Joe Peterson575537b2008-04-30 00:53:30 -07001194
1195 if (c == '\r') {
1196 if (I_IGNCR(tty))
1197 return;
1198 if (I_ICRNL(tty))
1199 c = '\n';
1200 } else if (c == '\n' && I_INLCR(tty))
1201 c = '\r';
1202
Linus Torvalds1da177e2005-04-16 15:20:36 -07001203 if (tty->icanon) {
1204 if (c == ERASE_CHAR(tty) || c == KILL_CHAR(tty) ||
1205 (c == WERASE_CHAR(tty) && L_IEXTEN(tty))) {
1206 eraser(c, tty);
Joe Petersona88a69c2009-01-02 13:40:53 +00001207 process_echoes(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001208 return;
1209 }
1210 if (c == LNEXT_CHAR(tty) && L_IEXTEN(tty)) {
1211 tty->lnext = 1;
1212 if (L_ECHO(tty)) {
1213 finish_erasing(tty);
1214 if (L_ECHOCTL(tty)) {
Joe Petersona88a69c2009-01-02 13:40:53 +00001215 echo_char_raw('^', tty);
1216 echo_char_raw('\b', tty);
1217 process_echoes(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001218 }
1219 }
1220 return;
1221 }
1222 if (c == REPRINT_CHAR(tty) && L_ECHO(tty) &&
1223 L_IEXTEN(tty)) {
1224 unsigned long tail = tty->canon_head;
1225
1226 finish_erasing(tty);
1227 echo_char(c, tty);
Joe Petersona88a69c2009-01-02 13:40:53 +00001228 echo_char_raw('\n', tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001229 while (tail != tty->read_head) {
1230 echo_char(tty->read_buf[tail], tty);
1231 tail = (tail+1) & (N_TTY_BUF_SIZE-1);
1232 }
Joe Petersona88a69c2009-01-02 13:40:53 +00001233 process_echoes(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001234 return;
1235 }
1236 if (c == '\n') {
Joe Petersonacc71bb2009-01-02 13:43:32 +00001237 if (tty->read_cnt >= N_TTY_BUF_SIZE) {
Joe Peterson7e94b1d2009-01-02 13:43:40 +00001238 if (L_ECHO(tty))
1239 process_output('\a', tty);
Joe Petersonacc71bb2009-01-02 13:43:32 +00001240 return;
1241 }
1242 if (L_ECHO(tty) || L_ECHONL(tty)) {
Joe Petersona88a69c2009-01-02 13:40:53 +00001243 echo_char_raw('\n', tty);
1244 process_echoes(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001245 }
1246 goto handle_newline;
1247 }
1248 if (c == EOF_CHAR(tty)) {
Joe Petersonacc71bb2009-01-02 13:43:32 +00001249 if (tty->read_cnt >= N_TTY_BUF_SIZE)
1250 return;
Alan Cox4edf1822008-02-08 04:18:44 -08001251 if (tty->canon_head != tty->read_head)
1252 set_bit(TTY_PUSH, &tty->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001253 c = __DISABLED_CHAR;
1254 goto handle_newline;
1255 }
1256 if ((c == EOL_CHAR(tty)) ||
1257 (c == EOL2_CHAR(tty) && L_IEXTEN(tty))) {
Joe Petersonacc71bb2009-01-02 13:43:32 +00001258 parmrk = (c == (unsigned char) '\377' && I_PARMRK(tty))
1259 ? 1 : 0;
1260 if (tty->read_cnt >= (N_TTY_BUF_SIZE - parmrk)) {
Joe Peterson7e94b1d2009-01-02 13:43:40 +00001261 if (L_ECHO(tty))
1262 process_output('\a', tty);
Joe Petersonacc71bb2009-01-02 13:43:32 +00001263 return;
1264 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001265 /*
1266 * XXX are EOL_CHAR and EOL2_CHAR echoed?!?
1267 */
1268 if (L_ECHO(tty)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001269 /* Record the column of first canon char. */
1270 if (tty->canon_head == tty->read_head)
Joe Petersona88a69c2009-01-02 13:40:53 +00001271 echo_set_canon_col(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001272 echo_char(c, tty);
Joe Petersona88a69c2009-01-02 13:40:53 +00001273 process_echoes(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001274 }
1275 /*
1276 * XXX does PARMRK doubling happen for
1277 * EOL_CHAR and EOL2_CHAR?
1278 */
Joe Petersonacc71bb2009-01-02 13:43:32 +00001279 if (parmrk)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001280 put_tty_queue(c, tty);
1281
Alan Cox4edf1822008-02-08 04:18:44 -08001282handle_newline:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001283 spin_lock_irqsave(&tty->read_lock, flags);
1284 set_bit(tty->read_head, tty->read_flags);
1285 put_tty_queue_nolock(c, tty);
1286 tty->canon_head = tty->read_head;
1287 tty->canon_data++;
1288 spin_unlock_irqrestore(&tty->read_lock, flags);
1289 kill_fasync(&tty->fasync, SIGIO, POLL_IN);
1290 if (waitqueue_active(&tty->read_wait))
1291 wake_up_interruptible(&tty->read_wait);
1292 return;
1293 }
1294 }
Alan Cox4edf1822008-02-08 04:18:44 -08001295
Joe Petersonacc71bb2009-01-02 13:43:32 +00001296 parmrk = (c == (unsigned char) '\377' && I_PARMRK(tty)) ? 1 : 0;
1297 if (tty->read_cnt >= (N_TTY_BUF_SIZE - parmrk - 1)) {
1298 /* beep if no space */
Joe Peterson7e94b1d2009-01-02 13:43:40 +00001299 if (L_ECHO(tty))
1300 process_output('\a', tty);
Joe Petersonacc71bb2009-01-02 13:43:32 +00001301 return;
1302 }
1303 if (L_ECHO(tty)) {
1304 finish_erasing(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001305 if (c == '\n')
Joe Petersona88a69c2009-01-02 13:40:53 +00001306 echo_char_raw('\n', tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001307 else {
1308 /* Record the column of first canon char. */
1309 if (tty->canon_head == tty->read_head)
Joe Petersona88a69c2009-01-02 13:40:53 +00001310 echo_set_canon_col(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001311 echo_char(c, tty);
1312 }
Joe Petersona88a69c2009-01-02 13:40:53 +00001313 process_echoes(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001314 }
1315
Joe Petersonacc71bb2009-01-02 13:43:32 +00001316 if (parmrk)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001317 put_tty_queue(c, tty);
1318
1319 put_tty_queue(c, tty);
Alan Cox4edf1822008-02-08 04:18:44 -08001320}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001321
Linus Torvalds1da177e2005-04-16 15:20:36 -07001322
1323/**
1324 * n_tty_write_wakeup - asynchronous I/O notifier
1325 * @tty: tty device
1326 *
1327 * Required for the ptys, serial driver etc. since processes
1328 * that attach themselves to the master and rely on ASYNC
1329 * IO must be woken up
1330 */
1331
1332static void n_tty_write_wakeup(struct tty_struct *tty)
1333{
Thomas Pfaffff8cb0f2009-01-02 13:47:13 +00001334 if (tty->fasync && test_and_clear_bit(TTY_DO_WRITE_WAKEUP, &tty->flags))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001335 kill_fasync(&tty->fasync, SIGIO, POLL_OUT);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001336}
1337
1338/**
1339 * n_tty_receive_buf - data receive
1340 * @tty: terminal device
1341 * @cp: buffer
1342 * @fp: flag buffer
1343 * @count: characters
1344 *
1345 * Called by the terminal driver when a block of characters has
1346 * been received. This function must be called from soft contexts
1347 * not from interrupt context. The driver is responsible for making
1348 * calls one at a time and in order (or using flush_to_ldisc)
1349 */
Alan Cox4edf1822008-02-08 04:18:44 -08001350
Linus Torvalds1da177e2005-04-16 15:20:36 -07001351static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
1352 char *fp, int count)
1353{
1354 const unsigned char *p;
1355 char *f, flags = TTY_NORMAL;
1356 int i;
1357 char buf[64];
1358 unsigned long cpuflags;
1359
1360 if (!tty->read_buf)
1361 return;
1362
1363 if (tty->real_raw) {
1364 spin_lock_irqsave(&tty->read_lock, cpuflags);
1365 i = min(N_TTY_BUF_SIZE - tty->read_cnt,
1366 N_TTY_BUF_SIZE - tty->read_head);
1367 i = min(count, i);
1368 memcpy(tty->read_buf + tty->read_head, cp, i);
1369 tty->read_head = (tty->read_head + i) & (N_TTY_BUF_SIZE-1);
1370 tty->read_cnt += i;
1371 cp += i;
1372 count -= i;
1373
1374 i = min(N_TTY_BUF_SIZE - tty->read_cnt,
1375 N_TTY_BUF_SIZE - tty->read_head);
1376 i = min(count, i);
1377 memcpy(tty->read_buf + tty->read_head, cp, i);
1378 tty->read_head = (tty->read_head + i) & (N_TTY_BUF_SIZE-1);
1379 tty->read_cnt += i;
1380 spin_unlock_irqrestore(&tty->read_lock, cpuflags);
1381 } else {
Alan Cox4edf1822008-02-08 04:18:44 -08001382 for (i = count, p = cp, f = fp; i; i--, p++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001383 if (f)
1384 flags = *f++;
1385 switch (flags) {
1386 case TTY_NORMAL:
1387 n_tty_receive_char(tty, *p);
1388 break;
1389 case TTY_BREAK:
1390 n_tty_receive_break(tty);
1391 break;
1392 case TTY_PARITY:
1393 case TTY_FRAME:
1394 n_tty_receive_parity_error(tty, *p);
1395 break;
1396 case TTY_OVERRUN:
1397 n_tty_receive_overrun(tty);
1398 break;
1399 default:
Alan Cox4edf1822008-02-08 04:18:44 -08001400 printk(KERN_ERR "%s: unknown flag %d\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -07001401 tty_name(tty, buf), flags);
1402 break;
1403 }
1404 }
Alan Coxf34d7a52008-04-30 00:54:13 -07001405 if (tty->ops->flush_chars)
1406 tty->ops->flush_chars(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001407 }
1408
Alan Cox33f0f882006-01-09 20:54:13 -08001409 n_tty_set_room(tty);
1410
Linus Torvalds1da177e2005-04-16 15:20:36 -07001411 if (!tty->icanon && (tty->read_cnt >= tty->minimum_to_wake)) {
1412 kill_fasync(&tty->fasync, SIGIO, POLL_IN);
1413 if (waitqueue_active(&tty->read_wait))
1414 wake_up_interruptible(&tty->read_wait);
1415 }
1416
1417 /*
1418 * Check the remaining room for the input canonicalization
1419 * mode. We don't want to throttle the driver if we're in
1420 * canonical mode and don't have a newline yet!
1421 */
Alan Cox39c2e602008-04-30 00:54:18 -07001422 if (tty->receive_room < TTY_THRESHOLD_THROTTLE)
1423 tty_throttle(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001424}
1425
1426int is_ignored(int sig)
1427{
1428 return (sigismember(&current->blocked, sig) ||
Alan Cox4edf1822008-02-08 04:18:44 -08001429 current->sighand->action[sig-1].sa.sa_handler == SIG_IGN);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001430}
1431
1432/**
1433 * n_tty_set_termios - termios data changed
1434 * @tty: terminal
1435 * @old: previous data
1436 *
1437 * Called by the tty layer when the user changes termios flags so
1438 * that the line discipline can plan ahead. This function cannot sleep
Alan Cox4edf1822008-02-08 04:18:44 -08001439 * and is protected from re-entry by the tty layer. The user is
Linus Torvalds1da177e2005-04-16 15:20:36 -07001440 * guaranteed that this function will not be re-entered or in progress
1441 * when the ldisc is closed.
Alan Cox17b82062008-10-13 10:45:06 +01001442 *
1443 * Locking: Caller holds tty->termios_mutex
Linus Torvalds1da177e2005-04-16 15:20:36 -07001444 */
Alan Cox4edf1822008-02-08 04:18:44 -08001445
1446static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001447{
Alan Cox47afa7a2008-10-13 10:44:17 +01001448 int canon_change = 1;
1449 BUG_ON(!tty);
1450
1451 if (old)
1452 canon_change = (old->c_lflag ^ tty->termios->c_lflag) & ICANON;
1453 if (canon_change) {
1454 memset(&tty->read_flags, 0, sizeof tty->read_flags);
1455 tty->canon_head = tty->read_tail;
1456 tty->canon_data = 0;
1457 tty->erasing = 0;
1458 }
1459
1460 if (canon_change && !L_ICANON(tty) && tty->read_cnt)
1461 wake_up_interruptible(&tty->read_wait);
Alan Cox4edf1822008-02-08 04:18:44 -08001462
Linus Torvalds1da177e2005-04-16 15:20:36 -07001463 tty->icanon = (L_ICANON(tty) != 0);
1464 if (test_bit(TTY_HW_COOK_IN, &tty->flags)) {
1465 tty->raw = 1;
1466 tty->real_raw = 1;
Alan Cox33f0f882006-01-09 20:54:13 -08001467 n_tty_set_room(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001468 return;
1469 }
1470 if (I_ISTRIP(tty) || I_IUCLC(tty) || I_IGNCR(tty) ||
1471 I_ICRNL(tty) || I_INLCR(tty) || L_ICANON(tty) ||
1472 I_IXON(tty) || L_ISIG(tty) || L_ECHO(tty) ||
1473 I_PARMRK(tty)) {
1474 memset(tty->process_char_map, 0, 256/8);
1475
1476 if (I_IGNCR(tty) || I_ICRNL(tty))
1477 set_bit('\r', tty->process_char_map);
1478 if (I_INLCR(tty))
1479 set_bit('\n', tty->process_char_map);
1480
1481 if (L_ICANON(tty)) {
1482 set_bit(ERASE_CHAR(tty), tty->process_char_map);
1483 set_bit(KILL_CHAR(tty), tty->process_char_map);
1484 set_bit(EOF_CHAR(tty), tty->process_char_map);
1485 set_bit('\n', tty->process_char_map);
1486 set_bit(EOL_CHAR(tty), tty->process_char_map);
1487 if (L_IEXTEN(tty)) {
1488 set_bit(WERASE_CHAR(tty),
1489 tty->process_char_map);
1490 set_bit(LNEXT_CHAR(tty),
1491 tty->process_char_map);
1492 set_bit(EOL2_CHAR(tty),
1493 tty->process_char_map);
1494 if (L_ECHO(tty))
1495 set_bit(REPRINT_CHAR(tty),
1496 tty->process_char_map);
1497 }
1498 }
1499 if (I_IXON(tty)) {
1500 set_bit(START_CHAR(tty), tty->process_char_map);
1501 set_bit(STOP_CHAR(tty), tty->process_char_map);
1502 }
1503 if (L_ISIG(tty)) {
1504 set_bit(INTR_CHAR(tty), tty->process_char_map);
1505 set_bit(QUIT_CHAR(tty), tty->process_char_map);
1506 set_bit(SUSP_CHAR(tty), tty->process_char_map);
1507 }
1508 clear_bit(__DISABLED_CHAR, tty->process_char_map);
1509 tty->raw = 0;
1510 tty->real_raw = 0;
1511 } else {
1512 tty->raw = 1;
1513 if ((I_IGNBRK(tty) || (!I_BRKINT(tty) && !I_PARMRK(tty))) &&
1514 (I_IGNPAR(tty) || !I_INPCK(tty)) &&
1515 (tty->driver->flags & TTY_DRIVER_REAL_RAW))
1516 tty->real_raw = 1;
1517 else
1518 tty->real_raw = 0;
1519 }
Alan Cox33f0f882006-01-09 20:54:13 -08001520 n_tty_set_room(tty);
Alan Coxf34d7a52008-04-30 00:54:13 -07001521 /* The termios change make the tty ready for I/O */
1522 wake_up_interruptible(&tty->write_wait);
1523 wake_up_interruptible(&tty->read_wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001524}
1525
1526/**
1527 * n_tty_close - close the ldisc for this tty
1528 * @tty: device
1529 *
Alan Cox4edf1822008-02-08 04:18:44 -08001530 * Called from the terminal layer when this line discipline is
1531 * being shut down, either because of a close or becsuse of a
Linus Torvalds1da177e2005-04-16 15:20:36 -07001532 * discipline change. The function will not be called while other
1533 * ldisc methods are in progress.
1534 */
Alan Cox4edf1822008-02-08 04:18:44 -08001535
Linus Torvalds1da177e2005-04-16 15:20:36 -07001536static void n_tty_close(struct tty_struct *tty)
1537{
1538 n_tty_flush_buffer(tty);
1539 if (tty->read_buf) {
Alan Cox0b4068a2009-06-11 13:05:49 +01001540 kfree(tty->read_buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001541 tty->read_buf = NULL;
1542 }
Joe Petersona88a69c2009-01-02 13:40:53 +00001543 if (tty->echo_buf) {
Alan Cox0b4068a2009-06-11 13:05:49 +01001544 kfree(tty->echo_buf);
Joe Petersona88a69c2009-01-02 13:40:53 +00001545 tty->echo_buf = NULL;
1546 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001547}
1548
1549/**
1550 * n_tty_open - open an ldisc
1551 * @tty: terminal to open
1552 *
Alan Cox4edf1822008-02-08 04:18:44 -08001553 * Called when this line discipline is being attached to the
Linus Torvalds1da177e2005-04-16 15:20:36 -07001554 * terminal device. Can sleep. Called serialized so that no
1555 * other events will occur in parallel. No further open will occur
1556 * until a close.
1557 */
1558
1559static int n_tty_open(struct tty_struct *tty)
1560{
1561 if (!tty)
1562 return -EINVAL;
1563
Joe Petersona88a69c2009-01-02 13:40:53 +00001564 /* These are ugly. Currently a malloc failure here can panic */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001565 if (!tty->read_buf) {
Alan Cox0b4068a2009-06-11 13:05:49 +01001566 tty->read_buf = kzalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001567 if (!tty->read_buf)
1568 return -ENOMEM;
1569 }
Joe Petersona88a69c2009-01-02 13:40:53 +00001570 if (!tty->echo_buf) {
Alan Cox0b4068a2009-06-11 13:05:49 +01001571 tty->echo_buf = kzalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
1572
Joe Petersona88a69c2009-01-02 13:40:53 +00001573 if (!tty->echo_buf)
1574 return -ENOMEM;
1575 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001576 reset_buffer_flags(tty);
1577 tty->column = 0;
1578 n_tty_set_termios(tty, NULL);
1579 tty->minimum_to_wake = 1;
1580 tty->closing = 0;
1581 return 0;
1582}
1583
1584static inline int input_available_p(struct tty_struct *tty, int amt)
1585{
OGAWA Hirofumie043e422009-07-29 12:15:56 -07001586 tty_flush_to_ldisc(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001587 if (tty->icanon) {
1588 if (tty->canon_data)
1589 return 1;
1590 } else if (tty->read_cnt >= (amt ? amt : 1))
1591 return 1;
1592
1593 return 0;
1594}
1595
1596/**
1597 * copy_from_read_buf - copy read data directly
1598 * @tty: terminal device
1599 * @b: user data
1600 * @nr: size of data
1601 *
Alan Cox11a96d12008-10-13 10:46:24 +01001602 * Helper function to speed up n_tty_read. It is only called when
Linus Torvalds1da177e2005-04-16 15:20:36 -07001603 * ICANON is off; it copies characters straight from the tty queue to
1604 * user space directly. It can be profitably called twice; once to
1605 * drain the space from the tail pointer to the (physical) end of the
1606 * buffer, and once to drain the space from the (physical) beginning of
1607 * the buffer to head pointer.
1608 *
Paul Fulghum817d6d32006-06-28 04:26:47 -07001609 * Called under the tty->atomic_read_lock sem
Linus Torvalds1da177e2005-04-16 15:20:36 -07001610 *
1611 */
Alan Cox4edf1822008-02-08 04:18:44 -08001612
Alan Cox33f0f882006-01-09 20:54:13 -08001613static int copy_from_read_buf(struct tty_struct *tty,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001614 unsigned char __user **b,
1615 size_t *nr)
1616
1617{
1618 int retval;
1619 size_t n;
1620 unsigned long flags;
1621
1622 retval = 0;
1623 spin_lock_irqsave(&tty->read_lock, flags);
1624 n = min(tty->read_cnt, N_TTY_BUF_SIZE - tty->read_tail);
1625 n = min(*nr, n);
1626 spin_unlock_irqrestore(&tty->read_lock, flags);
1627 if (n) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001628 retval = copy_to_user(*b, &tty->read_buf[tty->read_tail], n);
1629 n -= retval;
Miloslav Trmac522ed772007-07-15 23:40:56 -07001630 tty_audit_add_data(tty, &tty->read_buf[tty->read_tail], n);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001631 spin_lock_irqsave(&tty->read_lock, flags);
1632 tty->read_tail = (tty->read_tail + n) & (N_TTY_BUF_SIZE-1);
1633 tty->read_cnt -= n;
1634 spin_unlock_irqrestore(&tty->read_lock, flags);
1635 *b += n;
1636 *nr -= n;
1637 }
1638 return retval;
1639}
1640
Al Virocc4191d2008-03-29 03:08:48 +00001641extern ssize_t redirected_tty_write(struct file *, const char __user *,
Alan Cox4edf1822008-02-08 04:18:44 -08001642 size_t, loff_t *);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001643
1644/**
1645 * job_control - check job control
1646 * @tty: tty
1647 * @file: file handle
1648 *
1649 * Perform job control management checks on this file/tty descriptor
Alan Cox4edf1822008-02-08 04:18:44 -08001650 * and if appropriate send any needed signals and return a negative
Linus Torvalds1da177e2005-04-16 15:20:36 -07001651 * error code if action should be taken.
Alan Cox04f378b2008-04-30 00:53:29 -07001652 *
1653 * FIXME:
1654 * Locking: None - redirected write test is safe, testing
1655 * current->signal should possibly lock current->sighand
1656 * pgrp locking ?
Linus Torvalds1da177e2005-04-16 15:20:36 -07001657 */
Alan Cox4edf1822008-02-08 04:18:44 -08001658
Linus Torvalds1da177e2005-04-16 15:20:36 -07001659static int job_control(struct tty_struct *tty, struct file *file)
1660{
1661 /* Job control check -- must be done at start and after
1662 every sleep (POSIX.1 7.1.1.4). */
1663 /* NOTE: not yet done after every sleep pending a thorough
1664 check of the logic of this change. -- jlc */
1665 /* don't stop on /dev/console */
1666 if (file->f_op->write != redirected_tty_write &&
1667 current->signal->tty == tty) {
Eric W. Biedermanab521dc2007-02-12 00:53:00 -08001668 if (!tty->pgrp)
Alan Cox11a96d12008-10-13 10:46:24 +01001669 printk(KERN_ERR "n_tty_read: no tty->pgrp!\n");
Eric W. Biedermanab521dc2007-02-12 00:53:00 -08001670 else if (task_pgrp(current) != tty->pgrp) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001671 if (is_ignored(SIGTTIN) ||
Eric W. Biederman3e7cd6c2007-02-12 00:52:58 -08001672 is_current_pgrp_orphaned())
Linus Torvalds1da177e2005-04-16 15:20:36 -07001673 return -EIO;
Eric W. Biedermanab521dc2007-02-12 00:53:00 -08001674 kill_pgrp(task_pgrp(current), SIGTTIN, 1);
Oleg Nesterov040b6362007-06-01 00:46:53 -07001675 set_thread_flag(TIF_SIGPENDING);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001676 return -ERESTARTSYS;
1677 }
1678 }
1679 return 0;
1680}
Alan Cox4edf1822008-02-08 04:18:44 -08001681
Linus Torvalds1da177e2005-04-16 15:20:36 -07001682
1683/**
Alan Cox11a96d12008-10-13 10:46:24 +01001684 * n_tty_read - read function for tty
Linus Torvalds1da177e2005-04-16 15:20:36 -07001685 * @tty: tty device
1686 * @file: file object
1687 * @buf: userspace buffer pointer
1688 * @nr: size of I/O
1689 *
1690 * Perform reads for the line discipline. We are guaranteed that the
1691 * line discipline will not be closed under us but we may get multiple
1692 * parallel readers and must handle this ourselves. We may also get
1693 * a hangup. Always called in user context, may sleep.
1694 *
1695 * This code must be sure never to sleep through a hangup.
1696 */
Alan Cox4edf1822008-02-08 04:18:44 -08001697
Alan Cox11a96d12008-10-13 10:46:24 +01001698static ssize_t n_tty_read(struct tty_struct *tty, struct file *file,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001699 unsigned char __user *buf, size_t nr)
1700{
1701 unsigned char __user *b = buf;
1702 DECLARE_WAITQUEUE(wait, current);
1703 int c;
1704 int minimum, time;
1705 ssize_t retval = 0;
1706 ssize_t size;
1707 long timeout;
1708 unsigned long flags;
Alan Cox04f378b2008-04-30 00:53:29 -07001709 int packet;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001710
1711do_it_again:
1712
Alan Cox17b82062008-10-13 10:45:06 +01001713 BUG_ON(!tty->read_buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001714
1715 c = job_control(tty, file);
Alan Cox4edf1822008-02-08 04:18:44 -08001716 if (c < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001717 return c;
Alan Cox4edf1822008-02-08 04:18:44 -08001718
Linus Torvalds1da177e2005-04-16 15:20:36 -07001719 minimum = time = 0;
1720 timeout = MAX_SCHEDULE_TIMEOUT;
1721 if (!tty->icanon) {
1722 time = (HZ / 10) * TIME_CHAR(tty);
1723 minimum = MIN_CHAR(tty);
1724 if (minimum) {
1725 if (time)
1726 tty->minimum_to_wake = 1;
1727 else if (!waitqueue_active(&tty->read_wait) ||
1728 (tty->minimum_to_wake > minimum))
1729 tty->minimum_to_wake = minimum;
1730 } else {
1731 timeout = 0;
1732 if (time) {
1733 timeout = time;
1734 time = 0;
1735 }
1736 tty->minimum_to_wake = minimum = 1;
1737 }
1738 }
1739
1740 /*
1741 * Internal serialization of reads.
1742 */
1743 if (file->f_flags & O_NONBLOCK) {
Ingo Molnar70522e12006-03-23 03:00:31 -08001744 if (!mutex_trylock(&tty->atomic_read_lock))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001745 return -EAGAIN;
Alan Cox4edf1822008-02-08 04:18:44 -08001746 } else {
Ingo Molnar70522e12006-03-23 03:00:31 -08001747 if (mutex_lock_interruptible(&tty->atomic_read_lock))
Linus Torvalds1da177e2005-04-16 15:20:36 -07001748 return -ERESTARTSYS;
1749 }
Alan Cox04f378b2008-04-30 00:53:29 -07001750 packet = tty->packet;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001751
1752 add_wait_queue(&tty->read_wait, &wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001753 while (nr) {
1754 /* First test for status change. */
Alan Cox04f378b2008-04-30 00:53:29 -07001755 if (packet && tty->link->ctrl_status) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001756 unsigned char cs;
1757 if (b != buf)
1758 break;
Alan Cox04f378b2008-04-30 00:53:29 -07001759 spin_lock_irqsave(&tty->link->ctrl_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001760 cs = tty->link->ctrl_status;
1761 tty->link->ctrl_status = 0;
Alan Cox04f378b2008-04-30 00:53:29 -07001762 spin_unlock_irqrestore(&tty->link->ctrl_lock, flags);
Miloslav Trmac522ed772007-07-15 23:40:56 -07001763 if (tty_put_user(tty, cs, b++)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001764 retval = -EFAULT;
1765 b--;
1766 break;
1767 }
1768 nr--;
1769 break;
1770 }
1771 /* This statement must be first before checking for input
1772 so that any interrupt will set the state back to
1773 TASK_RUNNING. */
1774 set_current_state(TASK_INTERRUPTIBLE);
Alan Cox4edf1822008-02-08 04:18:44 -08001775
Linus Torvalds1da177e2005-04-16 15:20:36 -07001776 if (((minimum - (b - buf)) < tty->minimum_to_wake) &&
1777 ((minimum - (b - buf)) >= 1))
1778 tty->minimum_to_wake = (minimum - (b - buf));
Alan Cox4edf1822008-02-08 04:18:44 -08001779
Linus Torvalds1da177e2005-04-16 15:20:36 -07001780 if (!input_available_p(tty, 0)) {
1781 if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) {
1782 retval = -EIO;
1783 break;
1784 }
1785 if (tty_hung_up_p(file))
1786 break;
1787 if (!timeout)
1788 break;
1789 if (file->f_flags & O_NONBLOCK) {
1790 retval = -EAGAIN;
1791 break;
1792 }
1793 if (signal_pending(current)) {
1794 retval = -ERESTARTSYS;
1795 break;
1796 }
Alan Cox04f378b2008-04-30 00:53:29 -07001797 /* FIXME: does n_tty_set_room need locking ? */
Alan Cox33f0f882006-01-09 20:54:13 -08001798 n_tty_set_room(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001799 timeout = schedule_timeout(timeout);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001800 continue;
1801 }
1802 __set_current_state(TASK_RUNNING);
1803
1804 /* Deal with packet mode. */
Alan Cox04f378b2008-04-30 00:53:29 -07001805 if (packet && b == buf) {
Miloslav Trmac522ed772007-07-15 23:40:56 -07001806 if (tty_put_user(tty, TIOCPKT_DATA, b++)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001807 retval = -EFAULT;
1808 b--;
1809 break;
1810 }
1811 nr--;
1812 }
1813
1814 if (tty->icanon) {
1815 /* N.B. avoid overrun if nr == 0 */
1816 while (nr && tty->read_cnt) {
Alan Cox4edf1822008-02-08 04:18:44 -08001817 int eol;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001818
1819 eol = test_and_clear_bit(tty->read_tail,
1820 tty->read_flags);
1821 c = tty->read_buf[tty->read_tail];
1822 spin_lock_irqsave(&tty->read_lock, flags);
1823 tty->read_tail = ((tty->read_tail+1) &
1824 (N_TTY_BUF_SIZE-1));
1825 tty->read_cnt--;
1826 if (eol) {
1827 /* this test should be redundant:
1828 * we shouldn't be reading data if
1829 * canon_data is 0
1830 */
1831 if (--tty->canon_data < 0)
1832 tty->canon_data = 0;
1833 }
1834 spin_unlock_irqrestore(&tty->read_lock, flags);
1835
1836 if (!eol || (c != __DISABLED_CHAR)) {
Miloslav Trmac522ed772007-07-15 23:40:56 -07001837 if (tty_put_user(tty, c, b++)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001838 retval = -EFAULT;
1839 b--;
1840 break;
1841 }
1842 nr--;
1843 }
Miloslav Trmac522ed772007-07-15 23:40:56 -07001844 if (eol) {
1845 tty_audit_push(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001846 break;
Miloslav Trmac522ed772007-07-15 23:40:56 -07001847 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001848 }
1849 if (retval)
1850 break;
1851 } else {
1852 int uncopied;
Alan Cox04f378b2008-04-30 00:53:29 -07001853 /* The copy function takes the read lock and handles
1854 locking internally for this case */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001855 uncopied = copy_from_read_buf(tty, &b, &nr);
1856 uncopied += copy_from_read_buf(tty, &b, &nr);
1857 if (uncopied) {
1858 retval = -EFAULT;
1859 break;
1860 }
1861 }
1862
1863 /* If there is enough space in the read buffer now, let the
1864 * low-level driver know. We use n_tty_chars_in_buffer() to
1865 * check the buffer, as it now knows about canonical mode.
1866 * Otherwise, if the driver is throttled and the line is
1867 * longer than TTY_THRESHOLD_UNTHROTTLE in canonical mode,
1868 * we won't get any more characters.
1869 */
Paul Mackerras289a1e92006-06-12 12:16:26 +10001870 if (n_tty_chars_in_buffer(tty) <= TTY_THRESHOLD_UNTHROTTLE) {
1871 n_tty_set_room(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001872 check_unthrottle(tty);
Paul Mackerras289a1e92006-06-12 12:16:26 +10001873 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001874
1875 if (b - buf >= minimum)
1876 break;
1877 if (time)
1878 timeout = time;
1879 }
Ingo Molnar70522e12006-03-23 03:00:31 -08001880 mutex_unlock(&tty->atomic_read_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001881 remove_wait_queue(&tty->read_wait, &wait);
1882
1883 if (!waitqueue_active(&tty->read_wait))
1884 tty->minimum_to_wake = minimum;
1885
1886 __set_current_state(TASK_RUNNING);
1887 size = b - buf;
1888 if (size) {
1889 retval = size;
1890 if (nr)
Alan Cox4edf1822008-02-08 04:18:44 -08001891 clear_bit(TTY_PUSH, &tty->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001892 } else if (test_and_clear_bit(TTY_PUSH, &tty->flags))
1893 goto do_it_again;
1894
Alan Cox33f0f882006-01-09 20:54:13 -08001895 n_tty_set_room(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001896 return retval;
1897}
1898
1899/**
Alan Cox11a96d12008-10-13 10:46:24 +01001900 * n_tty_write - write function for tty
Linus Torvalds1da177e2005-04-16 15:20:36 -07001901 * @tty: tty device
1902 * @file: file object
1903 * @buf: userspace buffer pointer
1904 * @nr: size of I/O
1905 *
Joe Petersona88a69c2009-01-02 13:40:53 +00001906 * Write function of the terminal device. This is serialized with
Linus Torvalds1da177e2005-04-16 15:20:36 -07001907 * respect to other write callers but not to termios changes, reads
Joe Petersona88a69c2009-01-02 13:40:53 +00001908 * and other such events. Since the receive code will echo characters,
1909 * thus calling driver write methods, the output_lock is used in
1910 * the output processing functions called here as well as in the
1911 * echo processing function to protect the column state and space
1912 * left in the buffer.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001913 *
1914 * This code must be sure never to sleep through a hangup.
Joe Petersona88a69c2009-01-02 13:40:53 +00001915 *
1916 * Locking: output_lock to protect column state and space left
1917 * (note that the process_output*() functions take this
1918 * lock themselves)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001919 */
Alan Cox4edf1822008-02-08 04:18:44 -08001920
Alan Cox11a96d12008-10-13 10:46:24 +01001921static ssize_t n_tty_write(struct tty_struct *tty, struct file *file,
Joe Petersona88a69c2009-01-02 13:40:53 +00001922 const unsigned char *buf, size_t nr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001923{
1924 const unsigned char *b = buf;
1925 DECLARE_WAITQUEUE(wait, current);
1926 int c;
1927 ssize_t retval = 0;
1928
1929 /* Job control check -- must be done at start (POSIX.1 7.1.1.4). */
1930 if (L_TOSTOP(tty) && file->f_op->write != redirected_tty_write) {
1931 retval = tty_check_change(tty);
1932 if (retval)
1933 return retval;
1934 }
1935
Joe Petersona88a69c2009-01-02 13:40:53 +00001936 /* Write out any echoed characters that are still pending */
1937 process_echoes(tty);
Alan Cox300a6202009-01-02 13:41:04 +00001938
Linus Torvalds1da177e2005-04-16 15:20:36 -07001939 add_wait_queue(&tty->write_wait, &wait);
1940 while (1) {
1941 set_current_state(TASK_INTERRUPTIBLE);
1942 if (signal_pending(current)) {
1943 retval = -ERESTARTSYS;
1944 break;
1945 }
1946 if (tty_hung_up_p(file) || (tty->link && !tty->link->count)) {
1947 retval = -EIO;
1948 break;
1949 }
1950 if (O_OPOST(tty) && !(test_bit(TTY_HW_COOK_OUT, &tty->flags))) {
1951 while (nr > 0) {
Joe Petersona88a69c2009-01-02 13:40:53 +00001952 ssize_t num = process_output_block(tty, b, nr);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001953 if (num < 0) {
1954 if (num == -EAGAIN)
1955 break;
1956 retval = num;
1957 goto break_out;
1958 }
1959 b += num;
1960 nr -= num;
1961 if (nr == 0)
1962 break;
1963 c = *b;
Joe Petersona88a69c2009-01-02 13:40:53 +00001964 if (process_output(c, tty) < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001965 break;
1966 b++; nr--;
1967 }
Alan Coxf34d7a52008-04-30 00:54:13 -07001968 if (tty->ops->flush_chars)
1969 tty->ops->flush_chars(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001970 } else {
Roman Zippeld6afe272005-07-07 17:56:55 -07001971 while (nr > 0) {
Alan Coxf34d7a52008-04-30 00:54:13 -07001972 c = tty->ops->write(tty, b, nr);
Roman Zippeld6afe272005-07-07 17:56:55 -07001973 if (c < 0) {
1974 retval = c;
1975 goto break_out;
1976 }
1977 if (!c)
1978 break;
1979 b += c;
1980 nr -= c;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001981 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001982 }
1983 if (!nr)
1984 break;
1985 if (file->f_flags & O_NONBLOCK) {
1986 retval = -EAGAIN;
1987 break;
1988 }
1989 schedule();
1990 }
1991break_out:
1992 __set_current_state(TASK_RUNNING);
1993 remove_wait_queue(&tty->write_wait, &wait);
Thomas Pfaffff8cb0f2009-01-02 13:47:13 +00001994 if (b - buf != nr && tty->fasync)
1995 set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001996 return (b - buf) ? b - buf : retval;
1997}
1998
1999/**
Alan Cox11a96d12008-10-13 10:46:24 +01002000 * n_tty_poll - poll method for N_TTY
Linus Torvalds1da177e2005-04-16 15:20:36 -07002001 * @tty: terminal device
2002 * @file: file accessing it
2003 * @wait: poll table
2004 *
2005 * Called when the line discipline is asked to poll() for data or
2006 * for special events. This code is not serialized with respect to
2007 * other events save open/close.
2008 *
2009 * This code must be sure never to sleep through a hangup.
2010 * Called without the kernel lock held - fine
Linus Torvalds1da177e2005-04-16 15:20:36 -07002011 */
Alan Cox4edf1822008-02-08 04:18:44 -08002012
Alan Cox11a96d12008-10-13 10:46:24 +01002013static unsigned int n_tty_poll(struct tty_struct *tty, struct file *file,
Alan Cox4edf1822008-02-08 04:18:44 -08002014 poll_table *wait)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002015{
2016 unsigned int mask = 0;
2017
2018 poll_wait(file, &tty->read_wait, wait);
2019 poll_wait(file, &tty->write_wait, wait);
2020 if (input_available_p(tty, TIME_CHAR(tty) ? 0 : MIN_CHAR(tty)))
2021 mask |= POLLIN | POLLRDNORM;
2022 if (tty->packet && tty->link->ctrl_status)
2023 mask |= POLLPRI | POLLIN | POLLRDNORM;
2024 if (test_bit(TTY_OTHER_CLOSED, &tty->flags))
2025 mask |= POLLHUP;
2026 if (tty_hung_up_p(file))
2027 mask |= POLLHUP;
2028 if (!(mask & (POLLHUP | POLLIN | POLLRDNORM))) {
2029 if (MIN_CHAR(tty) && !TIME_CHAR(tty))
2030 tty->minimum_to_wake = MIN_CHAR(tty);
2031 else
2032 tty->minimum_to_wake = 1;
2033 }
Alan Coxf34d7a52008-04-30 00:54:13 -07002034 if (tty->ops->write && !tty_is_writelocked(tty) &&
2035 tty_chars_in_buffer(tty) < WAKEUP_CHARS &&
2036 tty_write_room(tty) > 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -07002037 mask |= POLLOUT | POLLWRNORM;
2038 return mask;
2039}
2040
Alan Cox47afa7a2008-10-13 10:44:17 +01002041static unsigned long inq_canon(struct tty_struct *tty)
2042{
2043 int nr, head, tail;
2044
Alan Cox17b82062008-10-13 10:45:06 +01002045 if (!tty->canon_data)
Alan Cox47afa7a2008-10-13 10:44:17 +01002046 return 0;
2047 head = tty->canon_head;
2048 tail = tty->read_tail;
2049 nr = (head - tail) & (N_TTY_BUF_SIZE-1);
2050 /* Skip EOF-chars.. */
2051 while (head != tail) {
2052 if (test_bit(tail, tty->read_flags) &&
2053 tty->read_buf[tail] == __DISABLED_CHAR)
2054 nr--;
2055 tail = (tail+1) & (N_TTY_BUF_SIZE-1);
2056 }
2057 return nr;
2058}
2059
2060static int n_tty_ioctl(struct tty_struct *tty, struct file *file,
2061 unsigned int cmd, unsigned long arg)
2062{
2063 int retval;
2064
2065 switch (cmd) {
2066 case TIOCOUTQ:
2067 return put_user(tty_chars_in_buffer(tty), (int __user *) arg);
2068 case TIOCINQ:
Alan Cox17b82062008-10-13 10:45:06 +01002069 /* FIXME: Locking */
Alan Cox47afa7a2008-10-13 10:44:17 +01002070 retval = tty->read_cnt;
2071 if (L_ICANON(tty))
2072 retval = inq_canon(tty);
2073 return put_user(retval, (unsigned int __user *) arg);
2074 default:
2075 return n_tty_ioctl_helper(tty, file, cmd, arg);
2076 }
2077}
2078
Alan Coxa352def2008-07-16 21:53:12 +01002079struct tty_ldisc_ops tty_ldisc_N_TTY = {
Paul Fulghume10cc1d2007-05-10 22:22:50 -07002080 .magic = TTY_LDISC_MAGIC,
2081 .name = "n_tty",
2082 .open = n_tty_open,
2083 .close = n_tty_close,
2084 .flush_buffer = n_tty_flush_buffer,
2085 .chars_in_buffer = n_tty_chars_in_buffer,
Alan Cox11a96d12008-10-13 10:46:24 +01002086 .read = n_tty_read,
2087 .write = n_tty_write,
Paul Fulghume10cc1d2007-05-10 22:22:50 -07002088 .ioctl = n_tty_ioctl,
2089 .set_termios = n_tty_set_termios,
Alan Cox11a96d12008-10-13 10:46:24 +01002090 .poll = n_tty_poll,
Paul Fulghume10cc1d2007-05-10 22:22:50 -07002091 .receive_buf = n_tty_receive_buf,
2092 .write_wakeup = n_tty_write_wakeup
Linus Torvalds1da177e2005-04-16 15:20:36 -07002093};