Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/drivers/char/pty.c | |
3 | * | |
4 | * Copyright (C) 1991, 1992 Linus Torvalds | |
5 | * | |
6 | * Added support for a Unix98-style ptmx device. | |
7 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998 | |
1da177e4 | 8 | * |
fe9cd962 AC |
9 | * When reading this code see also fs/devpts. In particular note that the |
10 | * driver_data field is used by the devpts side as a binding to the devpts | |
11 | * inode. | |
1da177e4 LT |
12 | */ |
13 | ||
fe9cd962 | 14 | #include <linux/module.h> |
1da177e4 LT |
15 | |
16 | #include <linux/errno.h> | |
1da177e4 LT |
17 | #include <linux/interrupt.h> |
18 | #include <linux/tty.h> | |
19 | #include <linux/tty_flip.h> | |
20 | #include <linux/fcntl.h> | |
d43c36dc | 21 | #include <linux/sched.h> |
1da177e4 LT |
22 | #include <linux/string.h> |
23 | #include <linux/major.h> | |
24 | #include <linux/mm.h> | |
25 | #include <linux/init.h> | |
405f5571 | 26 | #include <linux/smp_lock.h> |
1da177e4 | 27 | #include <linux/sysctl.h> |
d81ed103 | 28 | #include <linux/device.h> |
fe9cd962 | 29 | #include <linux/uaccess.h> |
1da177e4 LT |
30 | #include <linux/bitops.h> |
31 | #include <linux/devpts_fs.h> | |
5a0e3ad6 | 32 | #include <linux/slab.h> |
1da177e4 | 33 | |
fe9cd962 AC |
34 | #include <asm/system.h> |
35 | ||
1da177e4 | 36 | #ifdef CONFIG_UNIX98_PTYS |
da2bdf9a | 37 | static struct tty_driver *ptm_driver; |
1da177e4 LT |
38 | static struct tty_driver *pts_driver; |
39 | #endif | |
40 | ||
fe9cd962 | 41 | static void pty_close(struct tty_struct *tty, struct file *filp) |
1da177e4 | 42 | { |
fe9cd962 AC |
43 | BUG_ON(!tty); |
44 | if (tty->driver->subtype == PTY_TYPE_MASTER) | |
45 | WARN_ON(tty->count > 1); | |
46 | else { | |
1da177e4 LT |
47 | if (tty->count > 2) |
48 | return; | |
49 | } | |
50 | wake_up_interruptible(&tty->read_wait); | |
51 | wake_up_interruptible(&tty->write_wait); | |
52 | tty->packet = 0; | |
53 | if (!tty->link) | |
54 | return; | |
55 | tty->link->packet = 0; | |
56 | set_bit(TTY_OTHER_CLOSED, &tty->link->flags); | |
57 | wake_up_interruptible(&tty->link->read_wait); | |
58 | wake_up_interruptible(&tty->link->write_wait); | |
59 | if (tty->driver->subtype == PTY_TYPE_MASTER) { | |
60 | set_bit(TTY_OTHER_CLOSED, &tty->flags); | |
61 | #ifdef CONFIG_UNIX98_PTYS | |
62 | if (tty->driver == ptm_driver) | |
15f1a633 | 63 | devpts_pty_kill(tty->link); |
1da177e4 LT |
64 | #endif |
65 | tty_vhangup(tty->link); | |
66 | } | |
67 | } | |
68 | ||
69 | /* | |
70 | * The unthrottle routine is called by the line discipline to signal | |
71 | * that it can receive more characters. For PTY's, the TTY_THROTTLED | |
72 | * flag is always set, to force the line discipline to always call the | |
fe9cd962 | 73 | * unthrottle routine when there are fewer than TTY_THRESHOLD_UNTHROTTLE |
1da177e4 LT |
74 | * characters in the queue. This is necessary since each time this |
75 | * happens, we need to wake up any sleeping processes that could be | |
76 | * (1) trying to send data to the pty, or (2) waiting in wait_until_sent() | |
77 | * for the pty buffer to be drained. | |
78 | */ | |
fe9cd962 | 79 | static void pty_unthrottle(struct tty_struct *tty) |
1da177e4 | 80 | { |
d945cb9c | 81 | tty_wakeup(tty->link); |
1da177e4 LT |
82 | set_bit(TTY_THROTTLED, &tty->flags); |
83 | } | |
84 | ||
d945cb9c AC |
85 | /** |
86 | * pty_space - report space left for writing | |
87 | * @to: tty we are writing into | |
1da177e4 | 88 | * |
d945cb9c AC |
89 | * The tty buffers allow 64K but we sneak a peak and clip at 8K this |
90 | * allows a lot of overspill room for echo and other fun messes to | |
91 | * be handled properly | |
92 | */ | |
93 | ||
94 | static int pty_space(struct tty_struct *to) | |
95 | { | |
96 | int n = 8192 - to->buf.memory_used; | |
97 | if (n < 0) | |
98 | return 0; | |
99 | return n; | |
100 | } | |
101 | ||
102 | /** | |
103 | * pty_write - write to a pty | |
104 | * @tty: the tty we write from | |
105 | * @buf: kernel buffer of data | |
106 | * @count: bytes to write | |
762faaed | 107 | * |
d945cb9c AC |
108 | * Our "hardware" write method. Data is coming from the ldisc which |
109 | * may be in a non sleeping state. We simply throw this at the other | |
110 | * end of the link as if we were an IRQ handler receiving stuff for | |
111 | * the other side of the pty/tty pair. | |
1da177e4 | 112 | */ |
d945cb9c | 113 | |
ac89a917 | 114 | static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c) |
1da177e4 LT |
115 | { |
116 | struct tty_struct *to = tty->link; | |
1da177e4 | 117 | |
d945cb9c | 118 | if (tty->stopped) |
1da177e4 | 119 | return 0; |
d945cb9c | 120 | |
d945cb9c AC |
121 | if (c > 0) { |
122 | /* Stuff the data into the input queue of the other end */ | |
123 | c = tty_insert_flip_string(to, buf, c); | |
124 | /* And shovel */ | |
202c4675 LT |
125 | if (c) { |
126 | tty_flip_buffer_push(to); | |
127 | tty_wakeup(tty); | |
128 | } | |
762faaed | 129 | } |
1da177e4 LT |
130 | return c; |
131 | } | |
132 | ||
d945cb9c AC |
133 | /** |
134 | * pty_write_room - write space | |
135 | * @tty: tty we are writing from | |
136 | * | |
137 | * Report how many bytes the ldisc can send into the queue for | |
138 | * the other device. | |
139 | */ | |
140 | ||
1da177e4 LT |
141 | static int pty_write_room(struct tty_struct *tty) |
142 | { | |
85dfd81d LT |
143 | if (tty->stopped) |
144 | return 0; | |
d945cb9c | 145 | return pty_space(tty->link); |
1da177e4 LT |
146 | } |
147 | ||
d945cb9c AC |
148 | /** |
149 | * pty_chars_in_buffer - characters currently in our tx queue | |
150 | * @tty: our tty | |
fe9cd962 | 151 | * |
d945cb9c AC |
152 | * Report how much we have in the transmit queue. As everything is |
153 | * instantly at the other end this is easy to implement. | |
1da177e4 | 154 | */ |
d945cb9c | 155 | |
1da177e4 LT |
156 | static int pty_chars_in_buffer(struct tty_struct *tty) |
157 | { | |
d945cb9c | 158 | return 0; |
1da177e4 LT |
159 | } |
160 | ||
161 | /* Set the lock flag on a pty */ | |
fe9cd962 | 162 | static int pty_set_lock(struct tty_struct *tty, int __user *arg) |
1da177e4 LT |
163 | { |
164 | int val; | |
fe9cd962 | 165 | if (get_user(val, arg)) |
1da177e4 LT |
166 | return -EFAULT; |
167 | if (val) | |
168 | set_bit(TTY_PTY_LOCK, &tty->flags); | |
169 | else | |
170 | clear_bit(TTY_PTY_LOCK, &tty->flags); | |
171 | return 0; | |
172 | } | |
173 | ||
174 | static void pty_flush_buffer(struct tty_struct *tty) | |
175 | { | |
176 | struct tty_struct *to = tty->link; | |
04f378b1 | 177 | unsigned long flags; |
fe9cd962 | 178 | |
1da177e4 LT |
179 | if (!to) |
180 | return; | |
d945cb9c | 181 | /* tty_buffer_flush(to); FIXME */ |
1da177e4 | 182 | if (to->packet) { |
04f378b1 | 183 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
1da177e4 LT |
184 | tty->ctrl_status |= TIOCPKT_FLUSHWRITE; |
185 | wake_up_interruptible(&to->read_wait); | |
04f378b1 | 186 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
1da177e4 LT |
187 | } |
188 | } | |
189 | ||
fe9cd962 | 190 | static int pty_open(struct tty_struct *tty, struct file *filp) |
1da177e4 LT |
191 | { |
192 | int retval = -ENODEV; | |
193 | ||
194 | if (!tty || !tty->link) | |
195 | goto out; | |
196 | ||
197 | retval = -EIO; | |
198 | if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) | |
199 | goto out; | |
200 | if (test_bit(TTY_PTY_LOCK, &tty->link->flags)) | |
201 | goto out; | |
202 | if (tty->link->count != 1) | |
203 | goto out; | |
204 | ||
205 | clear_bit(TTY_OTHER_CLOSED, &tty->link->flags); | |
206 | set_bit(TTY_THROTTLED, &tty->flags); | |
1da177e4 LT |
207 | retval = 0; |
208 | out: | |
209 | return retval; | |
210 | } | |
211 | ||
fe9cd962 AC |
212 | static void pty_set_termios(struct tty_struct *tty, |
213 | struct ktermios *old_termios) | |
1da177e4 | 214 | { |
fe9cd962 AC |
215 | tty->termios->c_cflag &= ~(CSIZE | PARENB); |
216 | tty->termios->c_cflag |= (CS8 | CREAD); | |
1da177e4 LT |
217 | } |
218 | ||
fc6f6238 AC |
219 | /** |
220 | * pty_do_resize - resize event | |
221 | * @tty: tty being resized | |
c774bda2 | 222 | * @ws: window size being set. |
fc6f6238 | 223 | * |
3ad2f3fb | 224 | * Update the termios variables and send the necessary signals to |
fc6f6238 AC |
225 | * peform a terminal resize correctly |
226 | */ | |
227 | ||
228 | int pty_resize(struct tty_struct *tty, struct winsize *ws) | |
229 | { | |
230 | struct pid *pgrp, *rpgrp; | |
231 | unsigned long flags; | |
232 | struct tty_struct *pty = tty->link; | |
233 | ||
234 | /* For a PTY we need to lock the tty side */ | |
235 | mutex_lock(&tty->termios_mutex); | |
236 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) | |
237 | goto done; | |
238 | ||
239 | /* Get the PID values and reference them so we can | |
240 | avoid holding the tty ctrl lock while sending signals. | |
241 | We need to lock these individually however. */ | |
242 | ||
243 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
244 | pgrp = get_pid(tty->pgrp); | |
245 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
246 | ||
247 | spin_lock_irqsave(&pty->ctrl_lock, flags); | |
248 | rpgrp = get_pid(pty->pgrp); | |
249 | spin_unlock_irqrestore(&pty->ctrl_lock, flags); | |
250 | ||
251 | if (pgrp) | |
252 | kill_pgrp(pgrp, SIGWINCH, 1); | |
253 | if (rpgrp != pgrp && rpgrp) | |
254 | kill_pgrp(rpgrp, SIGWINCH, 1); | |
255 | ||
256 | put_pid(pgrp); | |
257 | put_pid(rpgrp); | |
258 | ||
259 | tty->winsize = *ws; | |
260 | pty->winsize = *ws; /* Never used so will go away soon */ | |
261 | done: | |
262 | mutex_unlock(&tty->termios_mutex); | |
263 | return 0; | |
264 | } | |
265 | ||
342a5971 LT |
266 | /* Traditional BSD devices */ |
267 | #ifdef CONFIG_LEGACY_PTYS | |
268 | ||
bf970ee4 AC |
269 | static int pty_install(struct tty_driver *driver, struct tty_struct *tty) |
270 | { | |
271 | struct tty_struct *o_tty; | |
272 | int idx = tty->index; | |
273 | int retval; | |
274 | ||
275 | o_tty = alloc_tty_struct(); | |
276 | if (!o_tty) | |
277 | return -ENOMEM; | |
278 | if (!try_module_get(driver->other->owner)) { | |
279 | /* This cannot in fact currently happen */ | |
280 | free_tty_struct(o_tty); | |
281 | return -ENOMEM; | |
282 | } | |
283 | initialize_tty_struct(o_tty, driver->other, idx); | |
284 | ||
285 | /* We always use new tty termios data so we can do this | |
286 | the easy way .. */ | |
287 | retval = tty_init_termios(tty); | |
288 | if (retval) | |
289 | goto free_mem_out; | |
290 | ||
291 | retval = tty_init_termios(o_tty); | |
292 | if (retval) { | |
293 | tty_free_termios(tty); | |
294 | goto free_mem_out; | |
295 | } | |
fe9cd962 | 296 | |
bf970ee4 AC |
297 | /* |
298 | * Everything allocated ... set up the o_tty structure. | |
299 | */ | |
300 | driver->other->ttys[idx] = o_tty; | |
301 | tty_driver_kref_get(driver->other); | |
302 | if (driver->subtype == PTY_TYPE_MASTER) | |
303 | o_tty->count++; | |
304 | /* Establish the links in both directions */ | |
305 | tty->link = o_tty; | |
306 | o_tty->link = tty; | |
307 | ||
308 | tty_driver_kref_get(driver); | |
309 | tty->count++; | |
310 | driver->ttys[idx] = tty; | |
311 | return 0; | |
312 | free_mem_out: | |
313 | module_put(o_tty->driver->owner); | |
314 | free_tty_struct(o_tty); | |
315 | return -ENOMEM; | |
316 | } | |
317 | ||
1da177e4 LT |
318 | static int pty_bsd_ioctl(struct tty_struct *tty, struct file *file, |
319 | unsigned int cmd, unsigned long arg) | |
320 | { | |
321 | switch (cmd) { | |
322 | case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */ | |
323 | return pty_set_lock(tty, (int __user *) arg); | |
324 | } | |
325 | return -ENOIOCTLCMD; | |
326 | } | |
327 | ||
dc8c8587 KS |
328 | static int legacy_count = CONFIG_LEGACY_PTY_COUNT; |
329 | module_param(legacy_count, int, 0); | |
330 | ||
342a5971 LT |
331 | /* |
332 | * The master side of a pty can do TIOCSPTLCK and thus | |
333 | * has pty_bsd_ioctl. | |
334 | */ | |
335 | static const struct tty_operations master_pty_ops_bsd = { | |
336 | .install = pty_install, | |
3e8e88ca AC |
337 | .open = pty_open, |
338 | .close = pty_close, | |
339 | .write = pty_write, | |
340 | .write_room = pty_write_room, | |
341 | .flush_buffer = pty_flush_buffer, | |
342 | .chars_in_buffer = pty_chars_in_buffer, | |
343 | .unthrottle = pty_unthrottle, | |
344 | .set_termios = pty_set_termios, | |
345 | .ioctl = pty_bsd_ioctl, | |
fc6f6238 | 346 | .resize = pty_resize |
3e8e88ca AC |
347 | }; |
348 | ||
342a5971 LT |
349 | static const struct tty_operations slave_pty_ops_bsd = { |
350 | .install = pty_install, | |
351 | .open = pty_open, | |
352 | .close = pty_close, | |
353 | .write = pty_write, | |
354 | .write_room = pty_write_room, | |
355 | .flush_buffer = pty_flush_buffer, | |
356 | .chars_in_buffer = pty_chars_in_buffer, | |
357 | .unthrottle = pty_unthrottle, | |
358 | .set_termios = pty_set_termios, | |
359 | .resize = pty_resize | |
360 | }; | |
361 | ||
1da177e4 LT |
362 | static void __init legacy_pty_init(void) |
363 | { | |
342a5971 LT |
364 | struct tty_driver *pty_driver, *pty_slave_driver; |
365 | ||
dc8c8587 KS |
366 | if (legacy_count <= 0) |
367 | return; | |
1da177e4 | 368 | |
dc8c8587 | 369 | pty_driver = alloc_tty_driver(legacy_count); |
1da177e4 LT |
370 | if (!pty_driver) |
371 | panic("Couldn't allocate pty driver"); | |
372 | ||
dc8c8587 | 373 | pty_slave_driver = alloc_tty_driver(legacy_count); |
1da177e4 LT |
374 | if (!pty_slave_driver) |
375 | panic("Couldn't allocate pty slave driver"); | |
376 | ||
377 | pty_driver->owner = THIS_MODULE; | |
378 | pty_driver->driver_name = "pty_master"; | |
379 | pty_driver->name = "pty"; | |
1da177e4 LT |
380 | pty_driver->major = PTY_MASTER_MAJOR; |
381 | pty_driver->minor_start = 0; | |
382 | pty_driver->type = TTY_DRIVER_TYPE_PTY; | |
383 | pty_driver->subtype = PTY_TYPE_MASTER; | |
384 | pty_driver->init_termios = tty_std_termios; | |
385 | pty_driver->init_termios.c_iflag = 0; | |
386 | pty_driver->init_termios.c_oflag = 0; | |
387 | pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
388 | pty_driver->init_termios.c_lflag = 0; | |
606d099c AC |
389 | pty_driver->init_termios.c_ispeed = 38400; |
390 | pty_driver->init_termios.c_ospeed = 38400; | |
1da177e4 LT |
391 | pty_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW; |
392 | pty_driver->other = pty_slave_driver; | |
342a5971 | 393 | tty_set_operations(pty_driver, &master_pty_ops_bsd); |
1da177e4 LT |
394 | |
395 | pty_slave_driver->owner = THIS_MODULE; | |
396 | pty_slave_driver->driver_name = "pty_slave"; | |
397 | pty_slave_driver->name = "ttyp"; | |
1da177e4 LT |
398 | pty_slave_driver->major = PTY_SLAVE_MAJOR; |
399 | pty_slave_driver->minor_start = 0; | |
400 | pty_slave_driver->type = TTY_DRIVER_TYPE_PTY; | |
401 | pty_slave_driver->subtype = PTY_TYPE_SLAVE; | |
402 | pty_slave_driver->init_termios = tty_std_termios; | |
403 | pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
606d099c AC |
404 | pty_slave_driver->init_termios.c_ispeed = 38400; |
405 | pty_slave_driver->init_termios.c_ospeed = 38400; | |
1da177e4 LT |
406 | pty_slave_driver->flags = TTY_DRIVER_RESET_TERMIOS | |
407 | TTY_DRIVER_REAL_RAW; | |
408 | pty_slave_driver->other = pty_driver; | |
342a5971 | 409 | tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd); |
1da177e4 LT |
410 | |
411 | if (tty_register_driver(pty_driver)) | |
412 | panic("Couldn't register pty driver"); | |
413 | if (tty_register_driver(pty_slave_driver)) | |
414 | panic("Couldn't register pty slave driver"); | |
415 | } | |
416 | #else | |
417 | static inline void legacy_pty_init(void) { } | |
418 | #endif | |
419 | ||
420 | /* Unix98 devices */ | |
421 | #ifdef CONFIG_UNIX98_PTYS | |
422 | /* | |
423 | * sysctl support for setting limits on the number of Unix98 ptys allocated. | |
424 | * Otherwise one can eat up all kernel memory by opening /dev/ptmx repeatedly. | |
425 | */ | |
426 | int pty_limit = NR_UNIX98_PTY_DEFAULT; | |
fe9cd962 | 427 | static int pty_limit_min; |
1da177e4 | 428 | static int pty_limit_max = NR_UNIX98_PTY_MAX; |
fe9cd962 | 429 | static int pty_count; |
1da177e4 | 430 | |
d81ed103 AC |
431 | static struct cdev ptmx_cdev; |
432 | ||
35834ca1 | 433 | static struct ctl_table pty_table[] = { |
1da177e4 | 434 | { |
1da177e4 LT |
435 | .procname = "max", |
436 | .maxlen = sizeof(int), | |
437 | .mode = 0644, | |
438 | .data = &pty_limit, | |
6d456111 | 439 | .proc_handler = proc_dointvec_minmax, |
1da177e4 LT |
440 | .extra1 = &pty_limit_min, |
441 | .extra2 = &pty_limit_max, | |
442 | }, { | |
1da177e4 LT |
443 | .procname = "nr", |
444 | .maxlen = sizeof(int), | |
445 | .mode = 0444, | |
bf970ee4 | 446 | .data = &pty_count, |
6d456111 | 447 | .proc_handler = proc_dointvec, |
894d2491 EB |
448 | }, |
449 | {} | |
1da177e4 LT |
450 | }; |
451 | ||
35834ca1 EB |
452 | static struct ctl_table pty_kern_table[] = { |
453 | { | |
35834ca1 EB |
454 | .procname = "pty", |
455 | .mode = 0555, | |
456 | .child = pty_table, | |
457 | }, | |
458 | {} | |
459 | }; | |
460 | ||
461 | static struct ctl_table pty_root_table[] = { | |
462 | { | |
35834ca1 EB |
463 | .procname = "kernel", |
464 | .mode = 0555, | |
465 | .child = pty_kern_table, | |
466 | }, | |
467 | {} | |
468 | }; | |
469 | ||
470 | ||
1da177e4 LT |
471 | static int pty_unix98_ioctl(struct tty_struct *tty, struct file *file, |
472 | unsigned int cmd, unsigned long arg) | |
473 | { | |
474 | switch (cmd) { | |
475 | case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */ | |
476 | return pty_set_lock(tty, (int __user *)arg); | |
477 | case TIOCGPTN: /* Get PT Number */ | |
478 | return put_user(tty->index, (unsigned int __user *)arg); | |
479 | } | |
480 | ||
481 | return -ENOIOCTLCMD; | |
482 | } | |
483 | ||
99f1fe18 AC |
484 | /** |
485 | * ptm_unix98_lookup - find a pty master | |
486 | * @driver: ptm driver | |
487 | * @idx: tty index | |
488 | * | |
489 | * Look up a pty master device. Called under the tty_mutex for now. | |
490 | * This provides our locking. | |
491 | */ | |
492 | ||
15f1a633 SB |
493 | static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver, |
494 | struct inode *ptm_inode, int idx) | |
99f1fe18 | 495 | { |
15f1a633 | 496 | struct tty_struct *tty = devpts_get_tty(ptm_inode, idx); |
99f1fe18 AC |
497 | if (tty) |
498 | tty = tty->link; | |
499 | return tty; | |
500 | } | |
501 | ||
502 | /** | |
503 | * pts_unix98_lookup - find a pty slave | |
504 | * @driver: pts driver | |
505 | * @idx: tty index | |
506 | * | |
507 | * Look up a pty master device. Called under the tty_mutex for now. | |
508 | * This provides our locking. | |
509 | */ | |
510 | ||
15f1a633 SB |
511 | static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver, |
512 | struct inode *pts_inode, int idx) | |
99f1fe18 | 513 | { |
15f1a633 | 514 | struct tty_struct *tty = devpts_get_tty(pts_inode, idx); |
99f1fe18 AC |
515 | /* Master must be open before slave */ |
516 | if (!tty) | |
517 | return ERR_PTR(-EIO); | |
518 | return tty; | |
519 | } | |
520 | ||
bf970ee4 | 521 | static void pty_unix98_shutdown(struct tty_struct *tty) |
feebed65 AC |
522 | { |
523 | /* We have our own method as we don't use the tty index */ | |
524 | kfree(tty->termios); | |
feebed65 AC |
525 | } |
526 | ||
8b0a88d5 AC |
527 | /* We have no need to install and remove our tty objects as devpts does all |
528 | the work for us */ | |
529 | ||
bf970ee4 | 530 | static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 | 531 | { |
bf970ee4 AC |
532 | struct tty_struct *o_tty; |
533 | int idx = tty->index; | |
534 | ||
535 | o_tty = alloc_tty_struct(); | |
536 | if (!o_tty) | |
537 | return -ENOMEM; | |
538 | if (!try_module_get(driver->other->owner)) { | |
539 | /* This cannot in fact currently happen */ | |
540 | free_tty_struct(o_tty); | |
541 | return -ENOMEM; | |
542 | } | |
543 | initialize_tty_struct(o_tty, driver->other, idx); | |
544 | ||
8dff04ea | 545 | tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL); |
bf970ee4 AC |
546 | if (tty->termios == NULL) |
547 | goto free_mem_out; | |
548 | *tty->termios = driver->init_termios; | |
8dff04ea AC |
549 | tty->termios_locked = tty->termios + 1; |
550 | ||
551 | o_tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL); | |
bf970ee4 AC |
552 | if (o_tty->termios == NULL) |
553 | goto free_mem_out; | |
554 | *o_tty->termios = driver->other->init_termios; | |
8dff04ea | 555 | o_tty->termios_locked = o_tty->termios + 1; |
bf970ee4 AC |
556 | |
557 | tty_driver_kref_get(driver->other); | |
558 | if (driver->subtype == PTY_TYPE_MASTER) | |
559 | o_tty->count++; | |
560 | /* Establish the links in both directions */ | |
561 | tty->link = o_tty; | |
562 | o_tty->link = tty; | |
563 | /* | |
564 | * All structures have been allocated, so now we install them. | |
565 | * Failures after this point use release_tty to clean up, so | |
566 | * there's no need to null out the local pointers. | |
567 | */ | |
568 | tty_driver_kref_get(driver); | |
569 | tty->count++; | |
570 | pty_count++; | |
8b0a88d5 | 571 | return 0; |
bf970ee4 | 572 | free_mem_out: |
8dff04ea | 573 | kfree(o_tty->termios); |
bf970ee4 AC |
574 | module_put(o_tty->driver->owner); |
575 | free_tty_struct(o_tty); | |
8dff04ea | 576 | kfree(tty->termios); |
bf970ee4 | 577 | return -ENOMEM; |
8b0a88d5 AC |
578 | } |
579 | ||
bf970ee4 | 580 | static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 | 581 | { |
bf970ee4 | 582 | pty_count--; |
8b0a88d5 AC |
583 | } |
584 | ||
feebed65 | 585 | static const struct tty_operations ptm_unix98_ops = { |
99f1fe18 | 586 | .lookup = ptm_unix98_lookup, |
bf970ee4 AC |
587 | .install = pty_unix98_install, |
588 | .remove = pty_unix98_remove, | |
3e8e88ca AC |
589 | .open = pty_open, |
590 | .close = pty_close, | |
591 | .write = pty_write, | |
592 | .write_room = pty_write_room, | |
593 | .flush_buffer = pty_flush_buffer, | |
594 | .chars_in_buffer = pty_chars_in_buffer, | |
595 | .unthrottle = pty_unthrottle, | |
596 | .set_termios = pty_set_termios, | |
feebed65 | 597 | .ioctl = pty_unix98_ioctl, |
fc6f6238 AC |
598 | .shutdown = pty_unix98_shutdown, |
599 | .resize = pty_resize | |
3e8e88ca AC |
600 | }; |
601 | ||
99f1fe18 AC |
602 | static const struct tty_operations pty_unix98_ops = { |
603 | .lookup = pts_unix98_lookup, | |
bf970ee4 AC |
604 | .install = pty_unix98_install, |
605 | .remove = pty_unix98_remove, | |
99f1fe18 AC |
606 | .open = pty_open, |
607 | .close = pty_close, | |
608 | .write = pty_write, | |
609 | .write_room = pty_write_room, | |
610 | .flush_buffer = pty_flush_buffer, | |
611 | .chars_in_buffer = pty_chars_in_buffer, | |
612 | .unthrottle = pty_unthrottle, | |
613 | .set_termios = pty_set_termios, | |
bf970ee4 | 614 | .shutdown = pty_unix98_shutdown |
99f1fe18 | 615 | }; |
d81ed103 AC |
616 | |
617 | /** | |
618 | * ptmx_open - open a unix 98 pty master | |
619 | * @inode: inode of device file | |
620 | * @filp: file pointer to tty | |
621 | * | |
622 | * Allocate a unix98 pty master device from the ptmx driver. | |
623 | * | |
624 | * Locking: tty_mutex protects the init_dev work. tty->count should | |
625 | * protect the rest. | |
626 | * allocated_ptys_lock handles the list of free pty numbers | |
627 | */ | |
628 | ||
629 | static int __ptmx_open(struct inode *inode, struct file *filp) | |
630 | { | |
631 | struct tty_struct *tty; | |
632 | int retval; | |
633 | int index; | |
634 | ||
635 | nonseekable_open(inode, filp); | |
636 | ||
637 | /* find a device that is not in use. */ | |
15f1a633 | 638 | index = devpts_new_index(inode); |
d81ed103 AC |
639 | if (index < 0) |
640 | return index; | |
641 | ||
642 | mutex_lock(&tty_mutex); | |
73ec06fc | 643 | tty = tty_init_dev(ptm_driver, index, 1); |
d81ed103 AC |
644 | mutex_unlock(&tty_mutex); |
645 | ||
73ec06fc AC |
646 | if (IS_ERR(tty)) { |
647 | retval = PTR_ERR(tty); | |
d81ed103 | 648 | goto out; |
73ec06fc | 649 | } |
d81ed103 AC |
650 | |
651 | set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ | |
652 | filp->private_data = tty; | |
653 | file_move(filp, &tty->tty_files); | |
654 | ||
15f1a633 | 655 | retval = devpts_pty_new(inode, tty->link); |
d81ed103 AC |
656 | if (retval) |
657 | goto out1; | |
658 | ||
659 | retval = ptm_driver->ops->open(tty, filp); | |
660 | if (!retval) | |
661 | return 0; | |
662 | out1: | |
eeb89d91 | 663 | tty_release(inode, filp); |
d81ed103 AC |
664 | return retval; |
665 | out: | |
15f1a633 | 666 | devpts_kill_index(inode, index); |
d81ed103 AC |
667 | return retval; |
668 | } | |
669 | ||
670 | static int ptmx_open(struct inode *inode, struct file *filp) | |
671 | { | |
672 | int ret; | |
673 | ||
674 | lock_kernel(); | |
675 | ret = __ptmx_open(inode, filp); | |
676 | unlock_kernel(); | |
677 | return ret; | |
678 | } | |
679 | ||
680 | static struct file_operations ptmx_fops; | |
681 | ||
1da177e4 LT |
682 | static void __init unix98_pty_init(void) |
683 | { | |
1da177e4 LT |
684 | ptm_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX); |
685 | if (!ptm_driver) | |
686 | panic("Couldn't allocate Unix98 ptm driver"); | |
687 | pts_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX); | |
688 | if (!pts_driver) | |
689 | panic("Couldn't allocate Unix98 pts driver"); | |
690 | ||
691 | ptm_driver->owner = THIS_MODULE; | |
692 | ptm_driver->driver_name = "pty_master"; | |
693 | ptm_driver->name = "ptm"; | |
694 | ptm_driver->major = UNIX98_PTY_MASTER_MAJOR; | |
695 | ptm_driver->minor_start = 0; | |
696 | ptm_driver->type = TTY_DRIVER_TYPE_PTY; | |
697 | ptm_driver->subtype = PTY_TYPE_MASTER; | |
698 | ptm_driver->init_termios = tty_std_termios; | |
699 | ptm_driver->init_termios.c_iflag = 0; | |
700 | ptm_driver->init_termios.c_oflag = 0; | |
701 | ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
702 | ptm_driver->init_termios.c_lflag = 0; | |
606d099c AC |
703 | ptm_driver->init_termios.c_ispeed = 38400; |
704 | ptm_driver->init_termios.c_ospeed = 38400; | |
1da177e4 | 705 | ptm_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | |
331b8319 | 706 | TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM; |
1da177e4 | 707 | ptm_driver->other = pts_driver; |
feebed65 | 708 | tty_set_operations(ptm_driver, &ptm_unix98_ops); |
1da177e4 LT |
709 | |
710 | pts_driver->owner = THIS_MODULE; | |
711 | pts_driver->driver_name = "pty_slave"; | |
712 | pts_driver->name = "pts"; | |
713 | pts_driver->major = UNIX98_PTY_SLAVE_MAJOR; | |
714 | pts_driver->minor_start = 0; | |
715 | pts_driver->type = TTY_DRIVER_TYPE_PTY; | |
716 | pts_driver->subtype = PTY_TYPE_SLAVE; | |
717 | pts_driver->init_termios = tty_std_termios; | |
718 | pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
606d099c AC |
719 | pts_driver->init_termios.c_ispeed = 38400; |
720 | pts_driver->init_termios.c_ospeed = 38400; | |
1da177e4 | 721 | pts_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | |
331b8319 | 722 | TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM; |
1da177e4 | 723 | pts_driver->other = ptm_driver; |
99f1fe18 | 724 | tty_set_operations(pts_driver, &pty_unix98_ops); |
fe9cd962 | 725 | |
1da177e4 LT |
726 | if (tty_register_driver(ptm_driver)) |
727 | panic("Couldn't register Unix98 ptm driver"); | |
728 | if (tty_register_driver(pts_driver)) | |
729 | panic("Couldn't register Unix98 pts driver"); | |
730 | ||
fe9cd962 | 731 | register_sysctl_table(pty_root_table); |
d81ed103 AC |
732 | |
733 | /* Now create the /dev/ptmx special device */ | |
734 | tty_default_fops(&ptmx_fops); | |
735 | ptmx_fops.open = ptmx_open; | |
736 | ||
737 | cdev_init(&ptmx_cdev, &ptmx_fops); | |
738 | if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) || | |
739 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0) | |
740 | panic("Couldn't register /dev/ptmx driver\n"); | |
741 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx"); | |
1da177e4 | 742 | } |
d81ed103 | 743 | |
1da177e4 LT |
744 | #else |
745 | static inline void unix98_pty_init(void) { } | |
746 | #endif | |
747 | ||
748 | static int __init pty_init(void) | |
749 | { | |
750 | legacy_pty_init(); | |
751 | unix98_pty_init(); | |
752 | return 0; | |
753 | } | |
754 | module_init(pty_init); |