Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * n_tty.c --- implements the N_TTY line discipline. | |
4edf1827 | 3 | * |
1da177e4 LT |
4 | * 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 | |
4edf1827 | 11 | * to N_TTY if it can not switch to any other line discipline. |
1da177e4 LT |
12 | * |
13 | * Written by Theodore Ts'o, Copyright 1994. | |
4edf1827 | 14 | * |
1da177e4 LT |
15 | * This file also contains code originally written by Linus Torvalds, |
16 | * Copyright 1991, 1992, 1993, and by Julian Cowley, Copyright 1994. | |
4edf1827 | 17 | * |
1da177e4 LT |
18 | * 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 | * | |
4edf1827 | 23 | * 2000/01/20 Fixed SMP locking on put_tty_queue using bits of |
1da177e4 LT |
24 | * 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>. | |
11a96d18 | 29 | * Also fixed a bug in BLOCKING mode where n_tty_write returns |
1da177e4 LT |
30 | * 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> | |
522ed776 MT |
48 | #include <linux/audit.h> |
49 | #include <linux/file.h> | |
1da177e4 LT |
50 | |
51 | #include <asm/uaccess.h> | |
52 | #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 | ||
65 | static inline unsigned char *alloc_buf(void) | |
66 | { | |
b4e3ca1a | 67 | gfp_t prio = in_interrupt() ? GFP_ATOMIC : GFP_KERNEL; |
1da177e4 LT |
68 | |
69 | if (PAGE_SIZE != N_TTY_BUF_SIZE) | |
70 | return kmalloc(N_TTY_BUF_SIZE, prio); | |
71 | else | |
72 | return (unsigned char *)__get_free_page(prio); | |
73 | } | |
74 | ||
75 | static inline void free_buf(unsigned char *buf) | |
76 | { | |
77 | if (PAGE_SIZE != N_TTY_BUF_SIZE) | |
78 | kfree(buf); | |
79 | else | |
80 | free_page((unsigned long) buf); | |
81 | } | |
82 | ||
522ed776 MT |
83 | static inline int tty_put_user(struct tty_struct *tty, unsigned char x, |
84 | unsigned char __user *ptr) | |
85 | { | |
86 | tty_audit_add_data(tty, &x, 1); | |
87 | return put_user(x, ptr); | |
88 | } | |
89 | ||
33f0f88f AC |
90 | /** |
91 | * n_tty_set__room - receive space | |
92 | * @tty: terminal | |
93 | * | |
94 | * Called by the driver to find out how much data it is | |
95 | * permitted to feed to the line discipline without any being lost | |
96 | * and thus to manage flow control. Not serialized. Answers for the | |
97 | * "instant". | |
98 | */ | |
99 | ||
100 | static void n_tty_set_room(struct tty_struct *tty) | |
101 | { | |
17b82060 | 102 | /* tty->read_cnt is not read locked ? */ |
33f0f88f AC |
103 | int left = N_TTY_BUF_SIZE - tty->read_cnt - 1; |
104 | ||
105 | /* | |
106 | * If we are doing input canonicalization, and there are no | |
107 | * pending newlines, let characters through without limit, so | |
108 | * that erase characters will be handled. Other excess | |
109 | * characters will be beeped. | |
110 | */ | |
111 | if (left <= 0) | |
112 | left = tty->icanon && !tty->canon_data; | |
113 | tty->receive_room = left; | |
114 | } | |
115 | ||
116 | static void put_tty_queue_nolock(unsigned char c, struct tty_struct *tty) | |
1da177e4 LT |
117 | { |
118 | if (tty->read_cnt < N_TTY_BUF_SIZE) { | |
119 | tty->read_buf[tty->read_head] = c; | |
120 | tty->read_head = (tty->read_head + 1) & (N_TTY_BUF_SIZE-1); | |
121 | tty->read_cnt++; | |
122 | } | |
123 | } | |
124 | ||
17b82060 AC |
125 | /** |
126 | * put_tty_queue - add character to tty | |
127 | * @c: character | |
128 | * @tty: tty device | |
129 | * | |
130 | * Add a character to the tty read_buf queue. This is done under the | |
131 | * read_lock to serialize character addition and also to protect us | |
132 | * against parallel reads or flushes | |
133 | */ | |
134 | ||
33f0f88f | 135 | static void put_tty_queue(unsigned char c, struct tty_struct *tty) |
1da177e4 LT |
136 | { |
137 | unsigned long flags; | |
138 | /* | |
139 | * The problem of stomping on the buffers ends here. | |
140 | * Why didn't anyone see this one coming? --AJK | |
141 | */ | |
142 | spin_lock_irqsave(&tty->read_lock, flags); | |
143 | put_tty_queue_nolock(c, tty); | |
144 | spin_unlock_irqrestore(&tty->read_lock, flags); | |
145 | } | |
146 | ||
147 | /** | |
148 | * check_unthrottle - allow new receive data | |
149 | * @tty; tty device | |
150 | * | |
17b82060 AC |
151 | * Check whether to call the driver unthrottle functions |
152 | * | |
70522e12 | 153 | * Can sleep, may be called under the atomic_read_lock mutex but |
1da177e4 LT |
154 | * this is not guaranteed. |
155 | */ | |
4edf1827 | 156 | static void check_unthrottle(struct tty_struct *tty) |
1da177e4 | 157 | { |
39c2e60f AC |
158 | if (tty->count) |
159 | tty_unthrottle(tty); | |
1da177e4 LT |
160 | } |
161 | ||
162 | /** | |
163 | * reset_buffer_flags - reset buffer state | |
164 | * @tty: terminal to reset | |
165 | * | |
4edf1827 | 166 | * Reset the read buffer counters, clear the flags, |
1da177e4 LT |
167 | * and make sure the driver is unthrottled. Called |
168 | * from n_tty_open() and n_tty_flush_buffer(). | |
17b82060 AC |
169 | * |
170 | * Locking: tty_read_lock for read fields. | |
1da177e4 LT |
171 | */ |
172 | static void reset_buffer_flags(struct tty_struct *tty) | |
173 | { | |
174 | unsigned long flags; | |
175 | ||
176 | spin_lock_irqsave(&tty->read_lock, flags); | |
177 | tty->read_head = tty->read_tail = tty->read_cnt = 0; | |
178 | spin_unlock_irqrestore(&tty->read_lock, flags); | |
179 | tty->canon_head = tty->canon_data = tty->erasing = 0; | |
180 | memset(&tty->read_flags, 0, sizeof tty->read_flags); | |
33f0f88f | 181 | n_tty_set_room(tty); |
1da177e4 LT |
182 | check_unthrottle(tty); |
183 | } | |
184 | ||
185 | /** | |
186 | * n_tty_flush_buffer - clean input queue | |
187 | * @tty: terminal device | |
188 | * | |
189 | * Flush the input buffer. Called when the line discipline is | |
190 | * being closed, when the tty layer wants the buffer flushed (eg | |
191 | * at hangup) or when the N_TTY line discipline internally has to | |
192 | * clean the pending queue (for example some signals). | |
193 | * | |
17b82060 | 194 | * Locking: ctrl_lock, read_lock. |
1da177e4 | 195 | */ |
4edf1827 AC |
196 | |
197 | static void n_tty_flush_buffer(struct tty_struct *tty) | |
1da177e4 | 198 | { |
04f378b1 | 199 | unsigned long flags; |
1da177e4 LT |
200 | /* clear everything and unthrottle the driver */ |
201 | reset_buffer_flags(tty); | |
4edf1827 | 202 | |
1da177e4 LT |
203 | if (!tty->link) |
204 | return; | |
205 | ||
04f378b1 | 206 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
1da177e4 LT |
207 | if (tty->link->packet) { |
208 | tty->ctrl_status |= TIOCPKT_FLUSHREAD; | |
209 | wake_up_interruptible(&tty->link->read_wait); | |
210 | } | |
04f378b1 | 211 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
1da177e4 LT |
212 | } |
213 | ||
214 | /** | |
215 | * n_tty_chars_in_buffer - report available bytes | |
216 | * @tty: tty device | |
217 | * | |
218 | * Report the number of characters buffered to be delivered to user | |
4edf1827 | 219 | * at this instant in time. |
17b82060 AC |
220 | * |
221 | * Locking: read_lock | |
1da177e4 | 222 | */ |
4edf1827 | 223 | |
1da177e4 LT |
224 | static ssize_t n_tty_chars_in_buffer(struct tty_struct *tty) |
225 | { | |
226 | unsigned long flags; | |
227 | ssize_t n = 0; | |
228 | ||
229 | spin_lock_irqsave(&tty->read_lock, flags); | |
230 | if (!tty->icanon) { | |
231 | n = tty->read_cnt; | |
232 | } else if (tty->canon_data) { | |
233 | n = (tty->canon_head > tty->read_tail) ? | |
234 | tty->canon_head - tty->read_tail : | |
235 | tty->canon_head + (N_TTY_BUF_SIZE - tty->read_tail); | |
236 | } | |
237 | spin_unlock_irqrestore(&tty->read_lock, flags); | |
238 | return n; | |
239 | } | |
240 | ||
241 | /** | |
242 | * is_utf8_continuation - utf8 multibyte check | |
243 | * @c: byte to check | |
244 | * | |
245 | * Returns true if the utf8 character 'c' is a multibyte continuation | |
246 | * character. We use this to correctly compute the on screen size | |
247 | * of the character when printing | |
248 | */ | |
4edf1827 | 249 | |
1da177e4 LT |
250 | static inline int is_utf8_continuation(unsigned char c) |
251 | { | |
252 | return (c & 0xc0) == 0x80; | |
253 | } | |
254 | ||
255 | /** | |
256 | * is_continuation - multibyte check | |
257 | * @c: byte to check | |
258 | * | |
259 | * Returns true if the utf8 character 'c' is a multibyte continuation | |
260 | * character and the terminal is in unicode mode. | |
261 | */ | |
4edf1827 | 262 | |
1da177e4 LT |
263 | static inline int is_continuation(unsigned char c, struct tty_struct *tty) |
264 | { | |
265 | return I_IUTF8(tty) && is_utf8_continuation(c); | |
266 | } | |
267 | ||
268 | /** | |
269 | * opost - output post processor | |
270 | * @c: character (or partial unicode symbol) | |
271 | * @tty: terminal device | |
272 | * | |
273 | * Perform OPOST processing. Returns -1 when the output device is | |
274 | * full and the character must be retried. Note that Linux currently | |
275 | * ignores TABDLY, CRDLY, VTDLY, FFDLY and NLDLY. They simply aren't | |
276 | * relevant in the world today. If you ever need them, add them here. | |
277 | * | |
278 | * Called from both the receive and transmit sides and can be called | |
04f378b1 | 279 | * re-entrantly. Relies on lock_kernel() for tty->column state. |
1da177e4 | 280 | */ |
4edf1827 | 281 | |
1da177e4 LT |
282 | static int opost(unsigned char c, struct tty_struct *tty) |
283 | { | |
284 | int space, spaces; | |
285 | ||
f34d7a5b | 286 | space = tty_write_room(tty); |
1da177e4 LT |
287 | if (!space) |
288 | return -1; | |
289 | ||
04f378b1 | 290 | lock_kernel(); |
1da177e4 LT |
291 | if (O_OPOST(tty)) { |
292 | switch (c) { | |
293 | case '\n': | |
294 | if (O_ONLRET(tty)) | |
295 | tty->column = 0; | |
296 | if (O_ONLCR(tty)) { | |
487ad7ef IM |
297 | if (space < 2) { |
298 | unlock_kernel(); | |
1da177e4 | 299 | return -1; |
487ad7ef | 300 | } |
f34d7a5b | 301 | tty_put_char(tty, '\r'); |
1da177e4 LT |
302 | tty->column = 0; |
303 | } | |
304 | tty->canon_column = tty->column; | |
305 | break; | |
306 | case '\r': | |
487ad7ef IM |
307 | if (O_ONOCR(tty) && tty->column == 0) { |
308 | unlock_kernel(); | |
1da177e4 | 309 | return 0; |
487ad7ef | 310 | } |
1da177e4 LT |
311 | if (O_OCRNL(tty)) { |
312 | c = '\n'; | |
313 | if (O_ONLRET(tty)) | |
314 | tty->canon_column = tty->column = 0; | |
315 | break; | |
316 | } | |
317 | tty->canon_column = tty->column = 0; | |
318 | break; | |
319 | case '\t': | |
320 | spaces = 8 - (tty->column & 7); | |
321 | if (O_TABDLY(tty) == XTABS) { | |
487ad7ef IM |
322 | if (space < spaces) { |
323 | unlock_kernel(); | |
1da177e4 | 324 | return -1; |
487ad7ef | 325 | } |
1da177e4 | 326 | tty->column += spaces; |
f34d7a5b | 327 | tty->ops->write(tty, " ", spaces); |
487ad7ef | 328 | unlock_kernel(); |
1da177e4 LT |
329 | return 0; |
330 | } | |
331 | tty->column += spaces; | |
332 | break; | |
333 | case '\b': | |
334 | if (tty->column > 0) | |
335 | tty->column--; | |
336 | break; | |
337 | default: | |
338 | if (O_OLCUC(tty)) | |
339 | c = toupper(c); | |
340 | if (!iscntrl(c) && !is_continuation(c, tty)) | |
341 | tty->column++; | |
342 | break; | |
343 | } | |
344 | } | |
f34d7a5b | 345 | tty_put_char(tty, c); |
04f378b1 | 346 | unlock_kernel(); |
1da177e4 LT |
347 | return 0; |
348 | } | |
349 | ||
350 | /** | |
351 | * opost_block - block postprocess | |
352 | * @tty: terminal device | |
353 | * @inbuf: user buffer | |
354 | * @nr: number of bytes | |
355 | * | |
356 | * This path is used to speed up block console writes, among other | |
357 | * things when processing blocks of output data. It handles only | |
358 | * the simple cases normally found and helps to generate blocks of | |
359 | * symbols for the console driver and thus improve performance. | |
360 | * | |
11a96d18 | 361 | * Called from n_tty_write under the tty layer write lock. Relies |
04f378b1 | 362 | * on lock_kernel for the tty->column state. |
1da177e4 | 363 | */ |
4edf1827 AC |
364 | |
365 | static ssize_t opost_block(struct tty_struct *tty, | |
366 | const unsigned char *buf, unsigned int nr) | |
1da177e4 LT |
367 | { |
368 | int space; | |
369 | int i; | |
370 | const unsigned char *cp; | |
371 | ||
f34d7a5b | 372 | space = tty_write_room(tty); |
1da177e4 LT |
373 | if (!space) |
374 | return 0; | |
375 | if (nr > space) | |
376 | nr = space; | |
377 | ||
04f378b1 | 378 | lock_kernel(); |
1da177e4 LT |
379 | for (i = 0, cp = buf; i < nr; i++, cp++) { |
380 | switch (*cp) { | |
381 | case '\n': | |
382 | if (O_ONLRET(tty)) | |
383 | tty->column = 0; | |
384 | if (O_ONLCR(tty)) | |
385 | goto break_out; | |
386 | tty->canon_column = tty->column; | |
387 | break; | |
388 | case '\r': | |
389 | if (O_ONOCR(tty) && tty->column == 0) | |
390 | goto break_out; | |
391 | if (O_OCRNL(tty)) | |
392 | goto break_out; | |
393 | tty->canon_column = tty->column = 0; | |
394 | break; | |
395 | case '\t': | |
396 | goto break_out; | |
397 | case '\b': | |
398 | if (tty->column > 0) | |
399 | tty->column--; | |
400 | break; | |
401 | default: | |
402 | if (O_OLCUC(tty)) | |
403 | goto break_out; | |
404 | if (!iscntrl(*cp)) | |
405 | tty->column++; | |
406 | break; | |
407 | } | |
408 | } | |
409 | break_out: | |
f34d7a5b AC |
410 | if (tty->ops->flush_chars) |
411 | tty->ops->flush_chars(tty); | |
412 | i = tty->ops->write(tty, buf, i); | |
04f378b1 | 413 | unlock_kernel(); |
1da177e4 LT |
414 | return i; |
415 | } | |
416 | ||
417 | ||
1da177e4 LT |
418 | /** |
419 | * echo_char - echo characters | |
420 | * @c: unicode byte to echo | |
421 | * @tty: terminal device | |
422 | * | |
4edf1827 | 423 | * Echo user input back onto the screen. This must be called only when |
1da177e4 | 424 | * L_ECHO(tty) is true. Called from the driver receive_buf path. |
17b82060 AC |
425 | * |
426 | * Relies on BKL for tty column locking | |
1da177e4 LT |
427 | */ |
428 | ||
429 | static void echo_char(unsigned char c, struct tty_struct *tty) | |
430 | { | |
431 | if (L_ECHOCTL(tty) && iscntrl(c) && c != '\t') { | |
f34d7a5b AC |
432 | tty_put_char(tty, '^'); |
433 | tty_put_char(tty, c ^ 0100); | |
1da177e4 LT |
434 | tty->column += 2; |
435 | } else | |
436 | opost(c, tty); | |
437 | } | |
438 | ||
17b82060 AC |
439 | /** |
440 | * finsh_erasing - complete erase | |
441 | * @tty: tty doing the erase | |
442 | * | |
443 | * Relies on BKL for tty column locking | |
444 | */ | |
1da177e4 LT |
445 | static inline void finish_erasing(struct tty_struct *tty) |
446 | { | |
447 | if (tty->erasing) { | |
f34d7a5b | 448 | tty_put_char(tty, '/'); |
1da177e4 LT |
449 | tty->column++; |
450 | tty->erasing = 0; | |
451 | } | |
452 | } | |
453 | ||
454 | /** | |
455 | * eraser - handle erase function | |
456 | * @c: character input | |
457 | * @tty: terminal device | |
458 | * | |
3a4fa0a2 | 459 | * Perform erase and necessary output when an erase character is |
1da177e4 LT |
460 | * present in the stream from the driver layer. Handles the complexities |
461 | * of UTF-8 multibyte symbols. | |
17b82060 AC |
462 | * |
463 | * Locking: read_lock for tty buffers, BKL for column/erasing state | |
1da177e4 | 464 | */ |
4edf1827 | 465 | |
1da177e4 LT |
466 | static void eraser(unsigned char c, struct tty_struct *tty) |
467 | { | |
468 | enum { ERASE, WERASE, KILL } kill_type; | |
469 | int head, seen_alnums, cnt; | |
470 | unsigned long flags; | |
471 | ||
17b82060 | 472 | /* FIXME: locking needed ? */ |
1da177e4 LT |
473 | if (tty->read_head == tty->canon_head) { |
474 | /* opost('\a', tty); */ /* what do you think? */ | |
475 | return; | |
476 | } | |
477 | if (c == ERASE_CHAR(tty)) | |
478 | kill_type = ERASE; | |
479 | else if (c == WERASE_CHAR(tty)) | |
480 | kill_type = WERASE; | |
481 | else { | |
482 | if (!L_ECHO(tty)) { | |
483 | spin_lock_irqsave(&tty->read_lock, flags); | |
484 | tty->read_cnt -= ((tty->read_head - tty->canon_head) & | |
485 | (N_TTY_BUF_SIZE - 1)); | |
486 | tty->read_head = tty->canon_head; | |
487 | spin_unlock_irqrestore(&tty->read_lock, flags); | |
488 | return; | |
489 | } | |
490 | if (!L_ECHOK(tty) || !L_ECHOKE(tty) || !L_ECHOE(tty)) { | |
491 | spin_lock_irqsave(&tty->read_lock, flags); | |
492 | tty->read_cnt -= ((tty->read_head - tty->canon_head) & | |
493 | (N_TTY_BUF_SIZE - 1)); | |
494 | tty->read_head = tty->canon_head; | |
495 | spin_unlock_irqrestore(&tty->read_lock, flags); | |
496 | finish_erasing(tty); | |
497 | echo_char(KILL_CHAR(tty), tty); | |
498 | /* Add a newline if ECHOK is on and ECHOKE is off. */ | |
499 | if (L_ECHOK(tty)) | |
500 | opost('\n', tty); | |
501 | return; | |
502 | } | |
503 | kill_type = KILL; | |
504 | } | |
505 | ||
506 | seen_alnums = 0; | |
17b82060 | 507 | /* FIXME: Locking ?? */ |
1da177e4 LT |
508 | while (tty->read_head != tty->canon_head) { |
509 | head = tty->read_head; | |
510 | ||
511 | /* erase a single possibly multibyte character */ | |
512 | do { | |
513 | head = (head - 1) & (N_TTY_BUF_SIZE-1); | |
514 | c = tty->read_buf[head]; | |
515 | } while (is_continuation(c, tty) && head != tty->canon_head); | |
516 | ||
517 | /* do not partially erase */ | |
518 | if (is_continuation(c, tty)) | |
519 | break; | |
520 | ||
521 | if (kill_type == WERASE) { | |
522 | /* Equivalent to BSD's ALTWERASE. */ | |
523 | if (isalnum(c) || c == '_') | |
524 | seen_alnums++; | |
525 | else if (seen_alnums) | |
526 | break; | |
527 | } | |
528 | cnt = (tty->read_head - head) & (N_TTY_BUF_SIZE-1); | |
529 | spin_lock_irqsave(&tty->read_lock, flags); | |
530 | tty->read_head = head; | |
531 | tty->read_cnt -= cnt; | |
532 | spin_unlock_irqrestore(&tty->read_lock, flags); | |
533 | if (L_ECHO(tty)) { | |
534 | if (L_ECHOPRT(tty)) { | |
535 | if (!tty->erasing) { | |
f34d7a5b | 536 | tty_put_char(tty, '\\'); |
1da177e4 LT |
537 | tty->column++; |
538 | tty->erasing = 1; | |
539 | } | |
540 | /* if cnt > 1, output a multi-byte character */ | |
541 | echo_char(c, tty); | |
542 | while (--cnt > 0) { | |
543 | head = (head+1) & (N_TTY_BUF_SIZE-1); | |
f34d7a5b | 544 | tty_put_char(tty, tty->read_buf[head]); |
1da177e4 LT |
545 | } |
546 | } else if (kill_type == ERASE && !L_ECHOE(tty)) { | |
547 | echo_char(ERASE_CHAR(tty), tty); | |
548 | } else if (c == '\t') { | |
549 | unsigned int col = tty->canon_column; | |
550 | unsigned long tail = tty->canon_head; | |
551 | ||
552 | /* Find the column of the last char. */ | |
553 | while (tail != tty->read_head) { | |
554 | c = tty->read_buf[tail]; | |
555 | if (c == '\t') | |
556 | col = (col | 7) + 1; | |
557 | else if (iscntrl(c)) { | |
558 | if (L_ECHOCTL(tty)) | |
559 | col += 2; | |
560 | } else if (!is_continuation(c, tty)) | |
561 | col++; | |
562 | tail = (tail+1) & (N_TTY_BUF_SIZE-1); | |
563 | } | |
564 | ||
565 | /* should never happen */ | |
566 | if (tty->column > 0x80000000) | |
4edf1827 | 567 | tty->column = 0; |
1da177e4 LT |
568 | |
569 | /* Now backup to that column. */ | |
570 | while (tty->column > col) { | |
571 | /* Can't use opost here. */ | |
f34d7a5b | 572 | tty_put_char(tty, '\b'); |
1da177e4 LT |
573 | if (tty->column > 0) |
574 | tty->column--; | |
575 | } | |
576 | } else { | |
577 | if (iscntrl(c) && L_ECHOCTL(tty)) { | |
f34d7a5b AC |
578 | tty_put_char(tty, '\b'); |
579 | tty_put_char(tty, ' '); | |
580 | tty_put_char(tty, '\b'); | |
1da177e4 LT |
581 | if (tty->column > 0) |
582 | tty->column--; | |
583 | } | |
584 | if (!iscntrl(c) || L_ECHOCTL(tty)) { | |
f34d7a5b AC |
585 | tty_put_char(tty, '\b'); |
586 | tty_put_char(tty, ' '); | |
587 | tty_put_char(tty, '\b'); | |
1da177e4 LT |
588 | if (tty->column > 0) |
589 | tty->column--; | |
590 | } | |
591 | } | |
592 | } | |
593 | if (kill_type == ERASE) | |
594 | break; | |
595 | } | |
596 | if (tty->read_head == tty->canon_head) | |
597 | finish_erasing(tty); | |
598 | } | |
599 | ||
600 | /** | |
601 | * isig - handle the ISIG optio | |
602 | * @sig: signal | |
603 | * @tty: terminal | |
604 | * @flush: force flush | |
605 | * | |
606 | * Called when a signal is being sent due to terminal input. This | |
607 | * may caus terminal flushing to take place according to the termios | |
608 | * settings and character used. Called from the driver receive_buf | |
609 | * path so serialized. | |
17b82060 AC |
610 | * |
611 | * Locking: ctrl_lock, read_lock (both via flush buffer) | |
1da177e4 | 612 | */ |
4edf1827 | 613 | |
1da177e4 LT |
614 | static inline void isig(int sig, struct tty_struct *tty, int flush) |
615 | { | |
ab521dc0 EB |
616 | if (tty->pgrp) |
617 | kill_pgrp(tty->pgrp, sig, 1); | |
1da177e4 LT |
618 | if (flush || !L_NOFLSH(tty)) { |
619 | n_tty_flush_buffer(tty); | |
f34d7a5b | 620 | tty_driver_flush_buffer(tty); |
1da177e4 LT |
621 | } |
622 | } | |
623 | ||
624 | /** | |
625 | * n_tty_receive_break - handle break | |
626 | * @tty: terminal | |
627 | * | |
628 | * An RS232 break event has been hit in the incoming bitstream. This | |
629 | * can cause a variety of events depending upon the termios settings. | |
630 | * | |
631 | * Called from the receive_buf path so single threaded. | |
632 | */ | |
4edf1827 | 633 | |
1da177e4 LT |
634 | static inline void n_tty_receive_break(struct tty_struct *tty) |
635 | { | |
636 | if (I_IGNBRK(tty)) | |
637 | return; | |
638 | if (I_BRKINT(tty)) { | |
639 | isig(SIGINT, tty, 1); | |
640 | return; | |
641 | } | |
642 | if (I_PARMRK(tty)) { | |
643 | put_tty_queue('\377', tty); | |
644 | put_tty_queue('\0', tty); | |
645 | } | |
646 | put_tty_queue('\0', tty); | |
647 | wake_up_interruptible(&tty->read_wait); | |
648 | } | |
649 | ||
650 | /** | |
651 | * n_tty_receive_overrun - handle overrun reporting | |
652 | * @tty: terminal | |
653 | * | |
654 | * Data arrived faster than we could process it. While the tty | |
655 | * driver has flagged this the bits that were missed are gone | |
656 | * forever. | |
657 | * | |
658 | * Called from the receive_buf path so single threaded. Does not | |
659 | * need locking as num_overrun and overrun_time are function | |
660 | * private. | |
661 | */ | |
4edf1827 | 662 | |
1da177e4 LT |
663 | static inline void n_tty_receive_overrun(struct tty_struct *tty) |
664 | { | |
665 | char buf[64]; | |
666 | ||
667 | tty->num_overrun++; | |
668 | if (time_before(tty->overrun_time, jiffies - HZ) || | |
669 | time_after(tty->overrun_time, jiffies)) { | |
670 | printk(KERN_WARNING "%s: %d input overrun(s)\n", | |
671 | tty_name(tty, buf), | |
672 | tty->num_overrun); | |
673 | tty->overrun_time = jiffies; | |
674 | tty->num_overrun = 0; | |
675 | } | |
676 | } | |
677 | ||
678 | /** | |
679 | * n_tty_receive_parity_error - error notifier | |
680 | * @tty: terminal device | |
681 | * @c: character | |
682 | * | |
683 | * Process a parity error and queue the right data to indicate | |
3a4fa0a2 | 684 | * the error case if necessary. Locking as per n_tty_receive_buf. |
1da177e4 LT |
685 | */ |
686 | static inline void n_tty_receive_parity_error(struct tty_struct *tty, | |
687 | unsigned char c) | |
688 | { | |
4edf1827 | 689 | if (I_IGNPAR(tty)) |
1da177e4 | 690 | return; |
1da177e4 LT |
691 | if (I_PARMRK(tty)) { |
692 | put_tty_queue('\377', tty); | |
693 | put_tty_queue('\0', tty); | |
694 | put_tty_queue(c, tty); | |
695 | } else if (I_INPCK(tty)) | |
696 | put_tty_queue('\0', tty); | |
697 | else | |
698 | put_tty_queue(c, tty); | |
699 | wake_up_interruptible(&tty->read_wait); | |
700 | } | |
701 | ||
702 | /** | |
703 | * n_tty_receive_char - perform processing | |
704 | * @tty: terminal device | |
705 | * @c: character | |
706 | * | |
707 | * Process an individual character of input received from the driver. | |
4edf1827 | 708 | * This is serialized with respect to itself by the rules for the |
1da177e4 LT |
709 | * driver above. |
710 | */ | |
711 | ||
712 | static inline void n_tty_receive_char(struct tty_struct *tty, unsigned char c) | |
713 | { | |
714 | unsigned long flags; | |
715 | ||
716 | if (tty->raw) { | |
717 | put_tty_queue(c, tty); | |
718 | return; | |
719 | } | |
4edf1827 | 720 | |
1da177e4 LT |
721 | if (I_ISTRIP(tty)) |
722 | c &= 0x7f; | |
723 | if (I_IUCLC(tty) && L_IEXTEN(tty)) | |
724 | c=tolower(c); | |
725 | ||
54d2a37e JP |
726 | if (tty->stopped && !tty->flow_stopped && I_IXON(tty) && |
727 | ((I_IXANY(tty) && c != START_CHAR(tty) && c != STOP_CHAR(tty)) || | |
575537b3 | 728 | c == INTR_CHAR(tty) || c == QUIT_CHAR(tty) || c == SUSP_CHAR(tty))) |
54d2a37e JP |
729 | start_tty(tty); |
730 | ||
1da177e4 LT |
731 | if (tty->closing) { |
732 | if (I_IXON(tty)) { | |
733 | if (c == START_CHAR(tty)) | |
734 | start_tty(tty); | |
735 | else if (c == STOP_CHAR(tty)) | |
736 | stop_tty(tty); | |
737 | } | |
738 | return; | |
739 | } | |
740 | ||
741 | /* | |
742 | * If the previous character was LNEXT, or we know that this | |
743 | * character is not one of the characters that we'll have to | |
744 | * handle specially, do shortcut processing to speed things | |
745 | * up. | |
746 | */ | |
747 | if (!test_bit(c, tty->process_char_map) || tty->lnext) { | |
748 | finish_erasing(tty); | |
749 | tty->lnext = 0; | |
750 | if (L_ECHO(tty)) { | |
751 | if (tty->read_cnt >= N_TTY_BUF_SIZE-1) { | |
f34d7a5b | 752 | tty_put_char(tty, '\a'); /* beep if no space */ |
1da177e4 LT |
753 | return; |
754 | } | |
755 | /* Record the column of first canon char. */ | |
756 | if (tty->canon_head == tty->read_head) | |
757 | tty->canon_column = tty->column; | |
758 | echo_char(c, tty); | |
759 | } | |
760 | if (I_PARMRK(tty) && c == (unsigned char) '\377') | |
761 | put_tty_queue(c, tty); | |
762 | put_tty_queue(c, tty); | |
763 | return; | |
764 | } | |
4edf1827 | 765 | |
1da177e4 LT |
766 | if (I_IXON(tty)) { |
767 | if (c == START_CHAR(tty)) { | |
768 | start_tty(tty); | |
769 | return; | |
770 | } | |
771 | if (c == STOP_CHAR(tty)) { | |
772 | stop_tty(tty); | |
773 | return; | |
774 | } | |
775 | } | |
575537b3 | 776 | |
1da177e4 LT |
777 | if (L_ISIG(tty)) { |
778 | int signal; | |
779 | signal = SIGINT; | |
780 | if (c == INTR_CHAR(tty)) | |
781 | goto send_signal; | |
782 | signal = SIGQUIT; | |
783 | if (c == QUIT_CHAR(tty)) | |
784 | goto send_signal; | |
785 | signal = SIGTSTP; | |
786 | if (c == SUSP_CHAR(tty)) { | |
787 | send_signal: | |
ec5b1157 JP |
788 | /* |
789 | * Echo character, and then send the signal. | |
790 | * Note that we do not use isig() here because we want | |
791 | * the order to be: | |
792 | * 1) flush, 2) echo, 3) signal | |
793 | */ | |
794 | if (!L_NOFLSH(tty)) { | |
795 | n_tty_flush_buffer(tty); | |
f34d7a5b | 796 | tty_driver_flush_buffer(tty); |
ec5b1157 JP |
797 | } |
798 | if (L_ECHO(tty)) | |
799 | echo_char(c, tty); | |
800 | if (tty->pgrp) | |
801 | kill_pgrp(tty->pgrp, signal, 1); | |
1da177e4 LT |
802 | return; |
803 | } | |
804 | } | |
575537b3 JP |
805 | |
806 | if (c == '\r') { | |
807 | if (I_IGNCR(tty)) | |
808 | return; | |
809 | if (I_ICRNL(tty)) | |
810 | c = '\n'; | |
811 | } else if (c == '\n' && I_INLCR(tty)) | |
812 | c = '\r'; | |
813 | ||
1da177e4 LT |
814 | if (tty->icanon) { |
815 | if (c == ERASE_CHAR(tty) || c == KILL_CHAR(tty) || | |
816 | (c == WERASE_CHAR(tty) && L_IEXTEN(tty))) { | |
817 | eraser(c, tty); | |
818 | return; | |
819 | } | |
820 | if (c == LNEXT_CHAR(tty) && L_IEXTEN(tty)) { | |
821 | tty->lnext = 1; | |
822 | if (L_ECHO(tty)) { | |
823 | finish_erasing(tty); | |
824 | if (L_ECHOCTL(tty)) { | |
f34d7a5b AC |
825 | tty_put_char(tty, '^'); |
826 | tty_put_char(tty, '\b'); | |
1da177e4 LT |
827 | } |
828 | } | |
829 | return; | |
830 | } | |
831 | if (c == REPRINT_CHAR(tty) && L_ECHO(tty) && | |
832 | L_IEXTEN(tty)) { | |
833 | unsigned long tail = tty->canon_head; | |
834 | ||
835 | finish_erasing(tty); | |
836 | echo_char(c, tty); | |
837 | opost('\n', tty); | |
838 | while (tail != tty->read_head) { | |
839 | echo_char(tty->read_buf[tail], tty); | |
840 | tail = (tail+1) & (N_TTY_BUF_SIZE-1); | |
841 | } | |
842 | return; | |
843 | } | |
844 | if (c == '\n') { | |
845 | if (L_ECHO(tty) || L_ECHONL(tty)) { | |
d6afe27b | 846 | if (tty->read_cnt >= N_TTY_BUF_SIZE-1) |
f34d7a5b | 847 | tty_put_char(tty, '\a'); |
1da177e4 LT |
848 | opost('\n', tty); |
849 | } | |
850 | goto handle_newline; | |
851 | } | |
852 | if (c == EOF_CHAR(tty)) { | |
4edf1827 AC |
853 | if (tty->canon_head != tty->read_head) |
854 | set_bit(TTY_PUSH, &tty->flags); | |
1da177e4 LT |
855 | c = __DISABLED_CHAR; |
856 | goto handle_newline; | |
857 | } | |
858 | if ((c == EOL_CHAR(tty)) || | |
859 | (c == EOL2_CHAR(tty) && L_IEXTEN(tty))) { | |
860 | /* | |
861 | * XXX are EOL_CHAR and EOL2_CHAR echoed?!? | |
862 | */ | |
863 | if (L_ECHO(tty)) { | |
d6afe27b | 864 | if (tty->read_cnt >= N_TTY_BUF_SIZE-1) |
f34d7a5b | 865 | tty_put_char(tty, '\a'); |
1da177e4 LT |
866 | /* Record the column of first canon char. */ |
867 | if (tty->canon_head == tty->read_head) | |
868 | tty->canon_column = tty->column; | |
869 | echo_char(c, tty); | |
870 | } | |
871 | /* | |
872 | * XXX does PARMRK doubling happen for | |
873 | * EOL_CHAR and EOL2_CHAR? | |
874 | */ | |
875 | if (I_PARMRK(tty) && c == (unsigned char) '\377') | |
876 | put_tty_queue(c, tty); | |
877 | ||
4edf1827 | 878 | handle_newline: |
1da177e4 LT |
879 | spin_lock_irqsave(&tty->read_lock, flags); |
880 | set_bit(tty->read_head, tty->read_flags); | |
881 | put_tty_queue_nolock(c, tty); | |
882 | tty->canon_head = tty->read_head; | |
883 | tty->canon_data++; | |
884 | spin_unlock_irqrestore(&tty->read_lock, flags); | |
885 | kill_fasync(&tty->fasync, SIGIO, POLL_IN); | |
886 | if (waitqueue_active(&tty->read_wait)) | |
887 | wake_up_interruptible(&tty->read_wait); | |
888 | return; | |
889 | } | |
890 | } | |
4edf1827 | 891 | |
1da177e4 LT |
892 | finish_erasing(tty); |
893 | if (L_ECHO(tty)) { | |
894 | if (tty->read_cnt >= N_TTY_BUF_SIZE-1) { | |
f34d7a5b | 895 | tty_put_char(tty, '\a'); /* beep if no space */ |
1da177e4 LT |
896 | return; |
897 | } | |
898 | if (c == '\n') | |
899 | opost('\n', tty); | |
900 | else { | |
901 | /* Record the column of first canon char. */ | |
902 | if (tty->canon_head == tty->read_head) | |
903 | tty->canon_column = tty->column; | |
904 | echo_char(c, tty); | |
905 | } | |
906 | } | |
907 | ||
908 | if (I_PARMRK(tty) && c == (unsigned char) '\377') | |
909 | put_tty_queue(c, tty); | |
910 | ||
911 | put_tty_queue(c, tty); | |
4edf1827 | 912 | } |
1da177e4 | 913 | |
1da177e4 LT |
914 | |
915 | /** | |
916 | * n_tty_write_wakeup - asynchronous I/O notifier | |
917 | * @tty: tty device | |
918 | * | |
919 | * Required for the ptys, serial driver etc. since processes | |
920 | * that attach themselves to the master and rely on ASYNC | |
921 | * IO must be woken up | |
922 | */ | |
923 | ||
924 | static void n_tty_write_wakeup(struct tty_struct *tty) | |
925 | { | |
4edf1827 AC |
926 | if (tty->fasync) { |
927 | set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); | |
1da177e4 LT |
928 | kill_fasync(&tty->fasync, SIGIO, POLL_OUT); |
929 | } | |
1da177e4 LT |
930 | } |
931 | ||
932 | /** | |
933 | * n_tty_receive_buf - data receive | |
934 | * @tty: terminal device | |
935 | * @cp: buffer | |
936 | * @fp: flag buffer | |
937 | * @count: characters | |
938 | * | |
939 | * Called by the terminal driver when a block of characters has | |
940 | * been received. This function must be called from soft contexts | |
941 | * not from interrupt context. The driver is responsible for making | |
942 | * calls one at a time and in order (or using flush_to_ldisc) | |
943 | */ | |
4edf1827 | 944 | |
1da177e4 LT |
945 | static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp, |
946 | char *fp, int count) | |
947 | { | |
948 | const unsigned char *p; | |
949 | char *f, flags = TTY_NORMAL; | |
950 | int i; | |
951 | char buf[64]; | |
952 | unsigned long cpuflags; | |
953 | ||
954 | if (!tty->read_buf) | |
955 | return; | |
956 | ||
957 | if (tty->real_raw) { | |
958 | spin_lock_irqsave(&tty->read_lock, cpuflags); | |
959 | i = min(N_TTY_BUF_SIZE - tty->read_cnt, | |
960 | N_TTY_BUF_SIZE - tty->read_head); | |
961 | i = min(count, i); | |
962 | memcpy(tty->read_buf + tty->read_head, cp, i); | |
963 | tty->read_head = (tty->read_head + i) & (N_TTY_BUF_SIZE-1); | |
964 | tty->read_cnt += i; | |
965 | cp += i; | |
966 | count -= i; | |
967 | ||
968 | i = min(N_TTY_BUF_SIZE - tty->read_cnt, | |
969 | N_TTY_BUF_SIZE - tty->read_head); | |
970 | i = min(count, i); | |
971 | memcpy(tty->read_buf + tty->read_head, cp, i); | |
972 | tty->read_head = (tty->read_head + i) & (N_TTY_BUF_SIZE-1); | |
973 | tty->read_cnt += i; | |
974 | spin_unlock_irqrestore(&tty->read_lock, cpuflags); | |
975 | } else { | |
4edf1827 | 976 | for (i = count, p = cp, f = fp; i; i--, p++) { |
1da177e4 LT |
977 | if (f) |
978 | flags = *f++; | |
979 | switch (flags) { | |
980 | case TTY_NORMAL: | |
981 | n_tty_receive_char(tty, *p); | |
982 | break; | |
983 | case TTY_BREAK: | |
984 | n_tty_receive_break(tty); | |
985 | break; | |
986 | case TTY_PARITY: | |
987 | case TTY_FRAME: | |
988 | n_tty_receive_parity_error(tty, *p); | |
989 | break; | |
990 | case TTY_OVERRUN: | |
991 | n_tty_receive_overrun(tty); | |
992 | break; | |
993 | default: | |
4edf1827 | 994 | printk(KERN_ERR "%s: unknown flag %d\n", |
1da177e4 LT |
995 | tty_name(tty, buf), flags); |
996 | break; | |
997 | } | |
998 | } | |
f34d7a5b AC |
999 | if (tty->ops->flush_chars) |
1000 | tty->ops->flush_chars(tty); | |
1da177e4 LT |
1001 | } |
1002 | ||
33f0f88f AC |
1003 | n_tty_set_room(tty); |
1004 | ||
1da177e4 LT |
1005 | if (!tty->icanon && (tty->read_cnt >= tty->minimum_to_wake)) { |
1006 | kill_fasync(&tty->fasync, SIGIO, POLL_IN); | |
1007 | if (waitqueue_active(&tty->read_wait)) | |
1008 | wake_up_interruptible(&tty->read_wait); | |
1009 | } | |
1010 | ||
1011 | /* | |
1012 | * Check the remaining room for the input canonicalization | |
1013 | * mode. We don't want to throttle the driver if we're in | |
1014 | * canonical mode and don't have a newline yet! | |
1015 | */ | |
39c2e60f AC |
1016 | if (tty->receive_room < TTY_THRESHOLD_THROTTLE) |
1017 | tty_throttle(tty); | |
1da177e4 LT |
1018 | } |
1019 | ||
1020 | int is_ignored(int sig) | |
1021 | { | |
1022 | return (sigismember(¤t->blocked, sig) || | |
4edf1827 | 1023 | current->sighand->action[sig-1].sa.sa_handler == SIG_IGN); |
1da177e4 LT |
1024 | } |
1025 | ||
1026 | /** | |
1027 | * n_tty_set_termios - termios data changed | |
1028 | * @tty: terminal | |
1029 | * @old: previous data | |
1030 | * | |
1031 | * Called by the tty layer when the user changes termios flags so | |
1032 | * that the line discipline can plan ahead. This function cannot sleep | |
4edf1827 | 1033 | * and is protected from re-entry by the tty layer. The user is |
1da177e4 LT |
1034 | * guaranteed that this function will not be re-entered or in progress |
1035 | * when the ldisc is closed. | |
17b82060 AC |
1036 | * |
1037 | * Locking: Caller holds tty->termios_mutex | |
1da177e4 | 1038 | */ |
4edf1827 AC |
1039 | |
1040 | static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old) | |
1da177e4 | 1041 | { |
47afa7a5 AC |
1042 | int canon_change = 1; |
1043 | BUG_ON(!tty); | |
1044 | ||
1045 | if (old) | |
1046 | canon_change = (old->c_lflag ^ tty->termios->c_lflag) & ICANON; | |
1047 | if (canon_change) { | |
1048 | memset(&tty->read_flags, 0, sizeof tty->read_flags); | |
1049 | tty->canon_head = tty->read_tail; | |
1050 | tty->canon_data = 0; | |
1051 | tty->erasing = 0; | |
1052 | } | |
1053 | ||
1054 | if (canon_change && !L_ICANON(tty) && tty->read_cnt) | |
1055 | wake_up_interruptible(&tty->read_wait); | |
4edf1827 | 1056 | |
1da177e4 LT |
1057 | tty->icanon = (L_ICANON(tty) != 0); |
1058 | if (test_bit(TTY_HW_COOK_IN, &tty->flags)) { | |
1059 | tty->raw = 1; | |
1060 | tty->real_raw = 1; | |
33f0f88f | 1061 | n_tty_set_room(tty); |
1da177e4 LT |
1062 | return; |
1063 | } | |
1064 | if (I_ISTRIP(tty) || I_IUCLC(tty) || I_IGNCR(tty) || | |
1065 | I_ICRNL(tty) || I_INLCR(tty) || L_ICANON(tty) || | |
1066 | I_IXON(tty) || L_ISIG(tty) || L_ECHO(tty) || | |
1067 | I_PARMRK(tty)) { | |
1068 | memset(tty->process_char_map, 0, 256/8); | |
1069 | ||
1070 | if (I_IGNCR(tty) || I_ICRNL(tty)) | |
1071 | set_bit('\r', tty->process_char_map); | |
1072 | if (I_INLCR(tty)) | |
1073 | set_bit('\n', tty->process_char_map); | |
1074 | ||
1075 | if (L_ICANON(tty)) { | |
1076 | set_bit(ERASE_CHAR(tty), tty->process_char_map); | |
1077 | set_bit(KILL_CHAR(tty), tty->process_char_map); | |
1078 | set_bit(EOF_CHAR(tty), tty->process_char_map); | |
1079 | set_bit('\n', tty->process_char_map); | |
1080 | set_bit(EOL_CHAR(tty), tty->process_char_map); | |
1081 | if (L_IEXTEN(tty)) { | |
1082 | set_bit(WERASE_CHAR(tty), | |
1083 | tty->process_char_map); | |
1084 | set_bit(LNEXT_CHAR(tty), | |
1085 | tty->process_char_map); | |
1086 | set_bit(EOL2_CHAR(tty), | |
1087 | tty->process_char_map); | |
1088 | if (L_ECHO(tty)) | |
1089 | set_bit(REPRINT_CHAR(tty), | |
1090 | tty->process_char_map); | |
1091 | } | |
1092 | } | |
1093 | if (I_IXON(tty)) { | |
1094 | set_bit(START_CHAR(tty), tty->process_char_map); | |
1095 | set_bit(STOP_CHAR(tty), tty->process_char_map); | |
1096 | } | |
1097 | if (L_ISIG(tty)) { | |
1098 | set_bit(INTR_CHAR(tty), tty->process_char_map); | |
1099 | set_bit(QUIT_CHAR(tty), tty->process_char_map); | |
1100 | set_bit(SUSP_CHAR(tty), tty->process_char_map); | |
1101 | } | |
1102 | clear_bit(__DISABLED_CHAR, tty->process_char_map); | |
1103 | tty->raw = 0; | |
1104 | tty->real_raw = 0; | |
1105 | } else { | |
1106 | tty->raw = 1; | |
1107 | if ((I_IGNBRK(tty) || (!I_BRKINT(tty) && !I_PARMRK(tty))) && | |
1108 | (I_IGNPAR(tty) || !I_INPCK(tty)) && | |
1109 | (tty->driver->flags & TTY_DRIVER_REAL_RAW)) | |
1110 | tty->real_raw = 1; | |
1111 | else | |
1112 | tty->real_raw = 0; | |
1113 | } | |
33f0f88f | 1114 | n_tty_set_room(tty); |
f34d7a5b AC |
1115 | /* The termios change make the tty ready for I/O */ |
1116 | wake_up_interruptible(&tty->write_wait); | |
1117 | wake_up_interruptible(&tty->read_wait); | |
1da177e4 LT |
1118 | } |
1119 | ||
1120 | /** | |
1121 | * n_tty_close - close the ldisc for this tty | |
1122 | * @tty: device | |
1123 | * | |
4edf1827 AC |
1124 | * Called from the terminal layer when this line discipline is |
1125 | * being shut down, either because of a close or becsuse of a | |
1da177e4 LT |
1126 | * discipline change. The function will not be called while other |
1127 | * ldisc methods are in progress. | |
1128 | */ | |
4edf1827 | 1129 | |
1da177e4 LT |
1130 | static void n_tty_close(struct tty_struct *tty) |
1131 | { | |
1132 | n_tty_flush_buffer(tty); | |
1133 | if (tty->read_buf) { | |
1134 | free_buf(tty->read_buf); | |
1135 | tty->read_buf = NULL; | |
1136 | } | |
1137 | } | |
1138 | ||
1139 | /** | |
1140 | * n_tty_open - open an ldisc | |
1141 | * @tty: terminal to open | |
1142 | * | |
4edf1827 | 1143 | * Called when this line discipline is being attached to the |
1da177e4 LT |
1144 | * terminal device. Can sleep. Called serialized so that no |
1145 | * other events will occur in parallel. No further open will occur | |
1146 | * until a close. | |
1147 | */ | |
1148 | ||
1149 | static int n_tty_open(struct tty_struct *tty) | |
1150 | { | |
1151 | if (!tty) | |
1152 | return -EINVAL; | |
1153 | ||
1154 | /* This one is ugly. Currently a malloc failure here can panic */ | |
1155 | if (!tty->read_buf) { | |
1156 | tty->read_buf = alloc_buf(); | |
1157 | if (!tty->read_buf) | |
1158 | return -ENOMEM; | |
1159 | } | |
1160 | memset(tty->read_buf, 0, N_TTY_BUF_SIZE); | |
1161 | reset_buffer_flags(tty); | |
1162 | tty->column = 0; | |
1163 | n_tty_set_termios(tty, NULL); | |
1164 | tty->minimum_to_wake = 1; | |
1165 | tty->closing = 0; | |
1166 | return 0; | |
1167 | } | |
1168 | ||
1169 | static inline int input_available_p(struct tty_struct *tty, int amt) | |
1170 | { | |
1171 | if (tty->icanon) { | |
1172 | if (tty->canon_data) | |
1173 | return 1; | |
1174 | } else if (tty->read_cnt >= (amt ? amt : 1)) | |
1175 | return 1; | |
1176 | ||
1177 | return 0; | |
1178 | } | |
1179 | ||
1180 | /** | |
1181 | * copy_from_read_buf - copy read data directly | |
1182 | * @tty: terminal device | |
1183 | * @b: user data | |
1184 | * @nr: size of data | |
1185 | * | |
11a96d18 | 1186 | * Helper function to speed up n_tty_read. It is only called when |
1da177e4 LT |
1187 | * ICANON is off; it copies characters straight from the tty queue to |
1188 | * user space directly. It can be profitably called twice; once to | |
1189 | * drain the space from the tail pointer to the (physical) end of the | |
1190 | * buffer, and once to drain the space from the (physical) beginning of | |
1191 | * the buffer to head pointer. | |
1192 | * | |
817d6d3b | 1193 | * Called under the tty->atomic_read_lock sem |
1da177e4 LT |
1194 | * |
1195 | */ | |
4edf1827 | 1196 | |
33f0f88f | 1197 | static int copy_from_read_buf(struct tty_struct *tty, |
1da177e4 LT |
1198 | unsigned char __user **b, |
1199 | size_t *nr) | |
1200 | ||
1201 | { | |
1202 | int retval; | |
1203 | size_t n; | |
1204 | unsigned long flags; | |
1205 | ||
1206 | retval = 0; | |
1207 | spin_lock_irqsave(&tty->read_lock, flags); | |
1208 | n = min(tty->read_cnt, N_TTY_BUF_SIZE - tty->read_tail); | |
1209 | n = min(*nr, n); | |
1210 | spin_unlock_irqrestore(&tty->read_lock, flags); | |
1211 | if (n) { | |
1da177e4 LT |
1212 | retval = copy_to_user(*b, &tty->read_buf[tty->read_tail], n); |
1213 | n -= retval; | |
522ed776 | 1214 | tty_audit_add_data(tty, &tty->read_buf[tty->read_tail], n); |
1da177e4 LT |
1215 | spin_lock_irqsave(&tty->read_lock, flags); |
1216 | tty->read_tail = (tty->read_tail + n) & (N_TTY_BUF_SIZE-1); | |
1217 | tty->read_cnt -= n; | |
1218 | spin_unlock_irqrestore(&tty->read_lock, flags); | |
1219 | *b += n; | |
1220 | *nr -= n; | |
1221 | } | |
1222 | return retval; | |
1223 | } | |
1224 | ||
cc4191dc | 1225 | extern ssize_t redirected_tty_write(struct file *, const char __user *, |
4edf1827 | 1226 | size_t, loff_t *); |
1da177e4 LT |
1227 | |
1228 | /** | |
1229 | * job_control - check job control | |
1230 | * @tty: tty | |
1231 | * @file: file handle | |
1232 | * | |
1233 | * Perform job control management checks on this file/tty descriptor | |
4edf1827 | 1234 | * and if appropriate send any needed signals and return a negative |
1da177e4 | 1235 | * error code if action should be taken. |
04f378b1 AC |
1236 | * |
1237 | * FIXME: | |
1238 | * Locking: None - redirected write test is safe, testing | |
1239 | * current->signal should possibly lock current->sighand | |
1240 | * pgrp locking ? | |
1da177e4 | 1241 | */ |
4edf1827 | 1242 | |
1da177e4 LT |
1243 | static int job_control(struct tty_struct *tty, struct file *file) |
1244 | { | |
1245 | /* Job control check -- must be done at start and after | |
1246 | every sleep (POSIX.1 7.1.1.4). */ | |
1247 | /* NOTE: not yet done after every sleep pending a thorough | |
1248 | check of the logic of this change. -- jlc */ | |
1249 | /* don't stop on /dev/console */ | |
1250 | if (file->f_op->write != redirected_tty_write && | |
1251 | current->signal->tty == tty) { | |
ab521dc0 | 1252 | if (!tty->pgrp) |
11a96d18 | 1253 | printk(KERN_ERR "n_tty_read: no tty->pgrp!\n"); |
ab521dc0 | 1254 | else if (task_pgrp(current) != tty->pgrp) { |
1da177e4 | 1255 | if (is_ignored(SIGTTIN) || |
3e7cd6c4 | 1256 | is_current_pgrp_orphaned()) |
1da177e4 | 1257 | return -EIO; |
ab521dc0 | 1258 | kill_pgrp(task_pgrp(current), SIGTTIN, 1); |
040b6362 | 1259 | set_thread_flag(TIF_SIGPENDING); |
1da177e4 LT |
1260 | return -ERESTARTSYS; |
1261 | } | |
1262 | } | |
1263 | return 0; | |
1264 | } | |
4edf1827 | 1265 | |
1da177e4 LT |
1266 | |
1267 | /** | |
11a96d18 | 1268 | * n_tty_read - read function for tty |
1da177e4 LT |
1269 | * @tty: tty device |
1270 | * @file: file object | |
1271 | * @buf: userspace buffer pointer | |
1272 | * @nr: size of I/O | |
1273 | * | |
1274 | * Perform reads for the line discipline. We are guaranteed that the | |
1275 | * line discipline will not be closed under us but we may get multiple | |
1276 | * parallel readers and must handle this ourselves. We may also get | |
1277 | * a hangup. Always called in user context, may sleep. | |
1278 | * | |
1279 | * This code must be sure never to sleep through a hangup. | |
1280 | */ | |
4edf1827 | 1281 | |
11a96d18 | 1282 | static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, |
1da177e4 LT |
1283 | unsigned char __user *buf, size_t nr) |
1284 | { | |
1285 | unsigned char __user *b = buf; | |
1286 | DECLARE_WAITQUEUE(wait, current); | |
1287 | int c; | |
1288 | int minimum, time; | |
1289 | ssize_t retval = 0; | |
1290 | ssize_t size; | |
1291 | long timeout; | |
1292 | unsigned long flags; | |
04f378b1 | 1293 | int packet; |
1da177e4 LT |
1294 | |
1295 | do_it_again: | |
1296 | ||
17b82060 | 1297 | BUG_ON(!tty->read_buf); |
1da177e4 LT |
1298 | |
1299 | c = job_control(tty, file); | |
4edf1827 | 1300 | if (c < 0) |
1da177e4 | 1301 | return c; |
4edf1827 | 1302 | |
1da177e4 LT |
1303 | minimum = time = 0; |
1304 | timeout = MAX_SCHEDULE_TIMEOUT; | |
1305 | if (!tty->icanon) { | |
1306 | time = (HZ / 10) * TIME_CHAR(tty); | |
1307 | minimum = MIN_CHAR(tty); | |
1308 | if (minimum) { | |
1309 | if (time) | |
1310 | tty->minimum_to_wake = 1; | |
1311 | else if (!waitqueue_active(&tty->read_wait) || | |
1312 | (tty->minimum_to_wake > minimum)) | |
1313 | tty->minimum_to_wake = minimum; | |
1314 | } else { | |
1315 | timeout = 0; | |
1316 | if (time) { | |
1317 | timeout = time; | |
1318 | time = 0; | |
1319 | } | |
1320 | tty->minimum_to_wake = minimum = 1; | |
1321 | } | |
1322 | } | |
1323 | ||
1324 | /* | |
1325 | * Internal serialization of reads. | |
1326 | */ | |
1327 | if (file->f_flags & O_NONBLOCK) { | |
70522e12 | 1328 | if (!mutex_trylock(&tty->atomic_read_lock)) |
1da177e4 | 1329 | return -EAGAIN; |
4edf1827 | 1330 | } else { |
70522e12 | 1331 | if (mutex_lock_interruptible(&tty->atomic_read_lock)) |
1da177e4 LT |
1332 | return -ERESTARTSYS; |
1333 | } | |
04f378b1 | 1334 | packet = tty->packet; |
1da177e4 LT |
1335 | |
1336 | add_wait_queue(&tty->read_wait, &wait); | |
1da177e4 LT |
1337 | while (nr) { |
1338 | /* First test for status change. */ | |
04f378b1 | 1339 | if (packet && tty->link->ctrl_status) { |
1da177e4 LT |
1340 | unsigned char cs; |
1341 | if (b != buf) | |
1342 | break; | |
04f378b1 | 1343 | spin_lock_irqsave(&tty->link->ctrl_lock, flags); |
1da177e4 LT |
1344 | cs = tty->link->ctrl_status; |
1345 | tty->link->ctrl_status = 0; | |
04f378b1 | 1346 | spin_unlock_irqrestore(&tty->link->ctrl_lock, flags); |
522ed776 | 1347 | if (tty_put_user(tty, cs, b++)) { |
1da177e4 LT |
1348 | retval = -EFAULT; |
1349 | b--; | |
1350 | break; | |
1351 | } | |
1352 | nr--; | |
1353 | break; | |
1354 | } | |
1355 | /* This statement must be first before checking for input | |
1356 | so that any interrupt will set the state back to | |
1357 | TASK_RUNNING. */ | |
1358 | set_current_state(TASK_INTERRUPTIBLE); | |
4edf1827 | 1359 | |
1da177e4 LT |
1360 | if (((minimum - (b - buf)) < tty->minimum_to_wake) && |
1361 | ((minimum - (b - buf)) >= 1)) | |
1362 | tty->minimum_to_wake = (minimum - (b - buf)); | |
4edf1827 | 1363 | |
1da177e4 LT |
1364 | if (!input_available_p(tty, 0)) { |
1365 | if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) { | |
1366 | retval = -EIO; | |
1367 | break; | |
1368 | } | |
1369 | if (tty_hung_up_p(file)) | |
1370 | break; | |
1371 | if (!timeout) | |
1372 | break; | |
1373 | if (file->f_flags & O_NONBLOCK) { | |
1374 | retval = -EAGAIN; | |
1375 | break; | |
1376 | } | |
1377 | if (signal_pending(current)) { | |
1378 | retval = -ERESTARTSYS; | |
1379 | break; | |
1380 | } | |
04f378b1 | 1381 | /* FIXME: does n_tty_set_room need locking ? */ |
33f0f88f | 1382 | n_tty_set_room(tty); |
1da177e4 | 1383 | timeout = schedule_timeout(timeout); |
1da177e4 LT |
1384 | continue; |
1385 | } | |
1386 | __set_current_state(TASK_RUNNING); | |
1387 | ||
1388 | /* Deal with packet mode. */ | |
04f378b1 | 1389 | if (packet && b == buf) { |
522ed776 | 1390 | if (tty_put_user(tty, TIOCPKT_DATA, b++)) { |
1da177e4 LT |
1391 | retval = -EFAULT; |
1392 | b--; | |
1393 | break; | |
1394 | } | |
1395 | nr--; | |
1396 | } | |
1397 | ||
1398 | if (tty->icanon) { | |
1399 | /* N.B. avoid overrun if nr == 0 */ | |
1400 | while (nr && tty->read_cnt) { | |
4edf1827 | 1401 | int eol; |
1da177e4 LT |
1402 | |
1403 | eol = test_and_clear_bit(tty->read_tail, | |
1404 | tty->read_flags); | |
1405 | c = tty->read_buf[tty->read_tail]; | |
1406 | spin_lock_irqsave(&tty->read_lock, flags); | |
1407 | tty->read_tail = ((tty->read_tail+1) & | |
1408 | (N_TTY_BUF_SIZE-1)); | |
1409 | tty->read_cnt--; | |
1410 | if (eol) { | |
1411 | /* this test should be redundant: | |
1412 | * we shouldn't be reading data if | |
1413 | * canon_data is 0 | |
1414 | */ | |
1415 | if (--tty->canon_data < 0) | |
1416 | tty->canon_data = 0; | |
1417 | } | |
1418 | spin_unlock_irqrestore(&tty->read_lock, flags); | |
1419 | ||
1420 | if (!eol || (c != __DISABLED_CHAR)) { | |
522ed776 | 1421 | if (tty_put_user(tty, c, b++)) { |
1da177e4 LT |
1422 | retval = -EFAULT; |
1423 | b--; | |
1424 | break; | |
1425 | } | |
1426 | nr--; | |
1427 | } | |
522ed776 MT |
1428 | if (eol) { |
1429 | tty_audit_push(tty); | |
1da177e4 | 1430 | break; |
522ed776 | 1431 | } |
1da177e4 LT |
1432 | } |
1433 | if (retval) | |
1434 | break; | |
1435 | } else { | |
1436 | int uncopied; | |
04f378b1 AC |
1437 | /* The copy function takes the read lock and handles |
1438 | locking internally for this case */ | |
1da177e4 LT |
1439 | uncopied = copy_from_read_buf(tty, &b, &nr); |
1440 | uncopied += copy_from_read_buf(tty, &b, &nr); | |
1441 | if (uncopied) { | |
1442 | retval = -EFAULT; | |
1443 | break; | |
1444 | } | |
1445 | } | |
1446 | ||
1447 | /* If there is enough space in the read buffer now, let the | |
1448 | * low-level driver know. We use n_tty_chars_in_buffer() to | |
1449 | * check the buffer, as it now knows about canonical mode. | |
1450 | * Otherwise, if the driver is throttled and the line is | |
1451 | * longer than TTY_THRESHOLD_UNTHROTTLE in canonical mode, | |
1452 | * we won't get any more characters. | |
1453 | */ | |
289a1e99 PM |
1454 | if (n_tty_chars_in_buffer(tty) <= TTY_THRESHOLD_UNTHROTTLE) { |
1455 | n_tty_set_room(tty); | |
1da177e4 | 1456 | check_unthrottle(tty); |
289a1e99 | 1457 | } |
1da177e4 LT |
1458 | |
1459 | if (b - buf >= minimum) | |
1460 | break; | |
1461 | if (time) | |
1462 | timeout = time; | |
1463 | } | |
70522e12 | 1464 | mutex_unlock(&tty->atomic_read_lock); |
1da177e4 LT |
1465 | remove_wait_queue(&tty->read_wait, &wait); |
1466 | ||
1467 | if (!waitqueue_active(&tty->read_wait)) | |
1468 | tty->minimum_to_wake = minimum; | |
1469 | ||
1470 | __set_current_state(TASK_RUNNING); | |
1471 | size = b - buf; | |
1472 | if (size) { | |
1473 | retval = size; | |
1474 | if (nr) | |
4edf1827 | 1475 | clear_bit(TTY_PUSH, &tty->flags); |
1da177e4 LT |
1476 | } else if (test_and_clear_bit(TTY_PUSH, &tty->flags)) |
1477 | goto do_it_again; | |
1478 | ||
33f0f88f | 1479 | n_tty_set_room(tty); |
1da177e4 LT |
1480 | return retval; |
1481 | } | |
1482 | ||
1483 | /** | |
11a96d18 | 1484 | * n_tty_write - write function for tty |
1da177e4 LT |
1485 | * @tty: tty device |
1486 | * @file: file object | |
1487 | * @buf: userspace buffer pointer | |
1488 | * @nr: size of I/O | |
1489 | * | |
1490 | * Write function of the terminal device. This is serialized with | |
1491 | * respect to other write callers but not to termios changes, reads | |
1492 | * and other such events. We must be careful with N_TTY as the receive | |
1493 | * code will echo characters, thus calling driver write methods. | |
1494 | * | |
1495 | * This code must be sure never to sleep through a hangup. | |
1496 | */ | |
4edf1827 | 1497 | |
11a96d18 | 1498 | static ssize_t n_tty_write(struct tty_struct *tty, struct file *file, |
4edf1827 | 1499 | const unsigned char *buf, size_t nr) |
1da177e4 LT |
1500 | { |
1501 | const unsigned char *b = buf; | |
1502 | DECLARE_WAITQUEUE(wait, current); | |
1503 | int c; | |
1504 | ssize_t retval = 0; | |
1505 | ||
1506 | /* Job control check -- must be done at start (POSIX.1 7.1.1.4). */ | |
1507 | if (L_TOSTOP(tty) && file->f_op->write != redirected_tty_write) { | |
1508 | retval = tty_check_change(tty); | |
1509 | if (retval) | |
1510 | return retval; | |
1511 | } | |
1512 | ||
1513 | add_wait_queue(&tty->write_wait, &wait); | |
1514 | while (1) { | |
1515 | set_current_state(TASK_INTERRUPTIBLE); | |
1516 | if (signal_pending(current)) { | |
1517 | retval = -ERESTARTSYS; | |
1518 | break; | |
1519 | } | |
1520 | if (tty_hung_up_p(file) || (tty->link && !tty->link->count)) { | |
1521 | retval = -EIO; | |
1522 | break; | |
1523 | } | |
1524 | if (O_OPOST(tty) && !(test_bit(TTY_HW_COOK_OUT, &tty->flags))) { | |
1525 | while (nr > 0) { | |
1526 | ssize_t num = opost_block(tty, b, nr); | |
1527 | if (num < 0) { | |
1528 | if (num == -EAGAIN) | |
1529 | break; | |
1530 | retval = num; | |
1531 | goto break_out; | |
1532 | } | |
1533 | b += num; | |
1534 | nr -= num; | |
1535 | if (nr == 0) | |
1536 | break; | |
1537 | c = *b; | |
1538 | if (opost(c, tty) < 0) | |
1539 | break; | |
1540 | b++; nr--; | |
1541 | } | |
f34d7a5b AC |
1542 | if (tty->ops->flush_chars) |
1543 | tty->ops->flush_chars(tty); | |
1da177e4 | 1544 | } else { |
d6afe27b | 1545 | while (nr > 0) { |
f34d7a5b | 1546 | c = tty->ops->write(tty, b, nr); |
d6afe27b RZ |
1547 | if (c < 0) { |
1548 | retval = c; | |
1549 | goto break_out; | |
1550 | } | |
1551 | if (!c) | |
1552 | break; | |
1553 | b += c; | |
1554 | nr -= c; | |
1da177e4 | 1555 | } |
1da177e4 LT |
1556 | } |
1557 | if (!nr) | |
1558 | break; | |
1559 | if (file->f_flags & O_NONBLOCK) { | |
1560 | retval = -EAGAIN; | |
1561 | break; | |
1562 | } | |
1563 | schedule(); | |
1564 | } | |
1565 | break_out: | |
1566 | __set_current_state(TASK_RUNNING); | |
1567 | remove_wait_queue(&tty->write_wait, &wait); | |
1568 | return (b - buf) ? b - buf : retval; | |
1569 | } | |
1570 | ||
1571 | /** | |
11a96d18 | 1572 | * n_tty_poll - poll method for N_TTY |
1da177e4 LT |
1573 | * @tty: terminal device |
1574 | * @file: file accessing it | |
1575 | * @wait: poll table | |
1576 | * | |
1577 | * Called when the line discipline is asked to poll() for data or | |
1578 | * for special events. This code is not serialized with respect to | |
1579 | * other events save open/close. | |
1580 | * | |
1581 | * This code must be sure never to sleep through a hangup. | |
1582 | * Called without the kernel lock held - fine | |
1da177e4 | 1583 | */ |
4edf1827 | 1584 | |
11a96d18 | 1585 | static unsigned int n_tty_poll(struct tty_struct *tty, struct file *file, |
4edf1827 | 1586 | poll_table *wait) |
1da177e4 LT |
1587 | { |
1588 | unsigned int mask = 0; | |
1589 | ||
1590 | poll_wait(file, &tty->read_wait, wait); | |
1591 | poll_wait(file, &tty->write_wait, wait); | |
1592 | if (input_available_p(tty, TIME_CHAR(tty) ? 0 : MIN_CHAR(tty))) | |
1593 | mask |= POLLIN | POLLRDNORM; | |
1594 | if (tty->packet && tty->link->ctrl_status) | |
1595 | mask |= POLLPRI | POLLIN | POLLRDNORM; | |
1596 | if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) | |
1597 | mask |= POLLHUP; | |
1598 | if (tty_hung_up_p(file)) | |
1599 | mask |= POLLHUP; | |
1600 | if (!(mask & (POLLHUP | POLLIN | POLLRDNORM))) { | |
1601 | if (MIN_CHAR(tty) && !TIME_CHAR(tty)) | |
1602 | tty->minimum_to_wake = MIN_CHAR(tty); | |
1603 | else | |
1604 | tty->minimum_to_wake = 1; | |
1605 | } | |
f34d7a5b AC |
1606 | if (tty->ops->write && !tty_is_writelocked(tty) && |
1607 | tty_chars_in_buffer(tty) < WAKEUP_CHARS && | |
1608 | tty_write_room(tty) > 0) | |
1da177e4 LT |
1609 | mask |= POLLOUT | POLLWRNORM; |
1610 | return mask; | |
1611 | } | |
1612 | ||
47afa7a5 AC |
1613 | static unsigned long inq_canon(struct tty_struct *tty) |
1614 | { | |
1615 | int nr, head, tail; | |
1616 | ||
17b82060 | 1617 | if (!tty->canon_data) |
47afa7a5 AC |
1618 | return 0; |
1619 | head = tty->canon_head; | |
1620 | tail = tty->read_tail; | |
1621 | nr = (head - tail) & (N_TTY_BUF_SIZE-1); | |
1622 | /* Skip EOF-chars.. */ | |
1623 | while (head != tail) { | |
1624 | if (test_bit(tail, tty->read_flags) && | |
1625 | tty->read_buf[tail] == __DISABLED_CHAR) | |
1626 | nr--; | |
1627 | tail = (tail+1) & (N_TTY_BUF_SIZE-1); | |
1628 | } | |
1629 | return nr; | |
1630 | } | |
1631 | ||
1632 | static int n_tty_ioctl(struct tty_struct *tty, struct file *file, | |
1633 | unsigned int cmd, unsigned long arg) | |
1634 | { | |
1635 | int retval; | |
1636 | ||
1637 | switch (cmd) { | |
1638 | case TIOCOUTQ: | |
1639 | return put_user(tty_chars_in_buffer(tty), (int __user *) arg); | |
1640 | case TIOCINQ: | |
17b82060 | 1641 | /* FIXME: Locking */ |
47afa7a5 AC |
1642 | retval = tty->read_cnt; |
1643 | if (L_ICANON(tty)) | |
1644 | retval = inq_canon(tty); | |
1645 | return put_user(retval, (unsigned int __user *) arg); | |
1646 | default: | |
1647 | return n_tty_ioctl_helper(tty, file, cmd, arg); | |
1648 | } | |
1649 | } | |
1650 | ||
a352def2 | 1651 | struct tty_ldisc_ops tty_ldisc_N_TTY = { |
e10cc1df PF |
1652 | .magic = TTY_LDISC_MAGIC, |
1653 | .name = "n_tty", | |
1654 | .open = n_tty_open, | |
1655 | .close = n_tty_close, | |
1656 | .flush_buffer = n_tty_flush_buffer, | |
1657 | .chars_in_buffer = n_tty_chars_in_buffer, | |
11a96d18 AC |
1658 | .read = n_tty_read, |
1659 | .write = n_tty_write, | |
e10cc1df PF |
1660 | .ioctl = n_tty_ioctl, |
1661 | .set_termios = n_tty_set_termios, | |
11a96d18 | 1662 | .poll = n_tty_poll, |
e10cc1df PF |
1663 | .receive_buf = n_tty_receive_buf, |
1664 | .write_wakeup = n_tty_write_wakeup | |
1da177e4 LT |
1665 | }; |
1666 |