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Commit | Line | Data |
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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> | |
21 | #include <linux/string.h> | |
22 | #include <linux/major.h> | |
23 | #include <linux/mm.h> | |
24 | #include <linux/init.h> | |
405f5571 | 25 | #include <linux/smp_lock.h> |
1da177e4 | 26 | #include <linux/sysctl.h> |
d81ed103 | 27 | #include <linux/device.h> |
fe9cd962 | 28 | #include <linux/uaccess.h> |
1da177e4 LT |
29 | #include <linux/bitops.h> |
30 | #include <linux/devpts_fs.h> | |
31 | ||
fe9cd962 AC |
32 | #include <asm/system.h> |
33 | ||
1da177e4 | 34 | #ifdef CONFIG_UNIX98_PTYS |
da2bdf9a | 35 | static struct tty_driver *ptm_driver; |
1da177e4 LT |
36 | static struct tty_driver *pts_driver; |
37 | #endif | |
38 | ||
fe9cd962 | 39 | static void pty_close(struct tty_struct *tty, struct file *filp) |
1da177e4 | 40 | { |
fe9cd962 AC |
41 | BUG_ON(!tty); |
42 | if (tty->driver->subtype == PTY_TYPE_MASTER) | |
43 | WARN_ON(tty->count > 1); | |
44 | else { | |
1da177e4 LT |
45 | if (tty->count > 2) |
46 | return; | |
47 | } | |
48 | wake_up_interruptible(&tty->read_wait); | |
49 | wake_up_interruptible(&tty->write_wait); | |
50 | tty->packet = 0; | |
51 | if (!tty->link) | |
52 | return; | |
53 | tty->link->packet = 0; | |
54 | set_bit(TTY_OTHER_CLOSED, &tty->link->flags); | |
55 | wake_up_interruptible(&tty->link->read_wait); | |
56 | wake_up_interruptible(&tty->link->write_wait); | |
57 | if (tty->driver->subtype == PTY_TYPE_MASTER) { | |
58 | set_bit(TTY_OTHER_CLOSED, &tty->flags); | |
59 | #ifdef CONFIG_UNIX98_PTYS | |
60 | if (tty->driver == ptm_driver) | |
15f1a633 | 61 | devpts_pty_kill(tty->link); |
1da177e4 LT |
62 | #endif |
63 | tty_vhangup(tty->link); | |
64 | } | |
65 | } | |
66 | ||
67 | /* | |
68 | * The unthrottle routine is called by the line discipline to signal | |
69 | * that it can receive more characters. For PTY's, the TTY_THROTTLED | |
70 | * flag is always set, to force the line discipline to always call the | |
fe9cd962 | 71 | * unthrottle routine when there are fewer than TTY_THRESHOLD_UNTHROTTLE |
1da177e4 LT |
72 | * characters in the queue. This is necessary since each time this |
73 | * happens, we need to wake up any sleeping processes that could be | |
74 | * (1) trying to send data to the pty, or (2) waiting in wait_until_sent() | |
75 | * for the pty buffer to be drained. | |
76 | */ | |
fe9cd962 | 77 | static void pty_unthrottle(struct tty_struct *tty) |
1da177e4 | 78 | { |
d945cb9c | 79 | tty_wakeup(tty->link); |
1da177e4 LT |
80 | set_bit(TTY_THROTTLED, &tty->flags); |
81 | } | |
82 | ||
d945cb9c AC |
83 | /** |
84 | * pty_space - report space left for writing | |
85 | * @to: tty we are writing into | |
1da177e4 | 86 | * |
d945cb9c AC |
87 | * The tty buffers allow 64K but we sneak a peak and clip at 8K this |
88 | * allows a lot of overspill room for echo and other fun messes to | |
89 | * be handled properly | |
90 | */ | |
91 | ||
92 | static int pty_space(struct tty_struct *to) | |
93 | { | |
94 | int n = 8192 - to->buf.memory_used; | |
95 | if (n < 0) | |
96 | return 0; | |
97 | return n; | |
98 | } | |
99 | ||
100 | /** | |
101 | * pty_write - write to a pty | |
102 | * @tty: the tty we write from | |
103 | * @buf: kernel buffer of data | |
104 | * @count: bytes to write | |
762faaed | 105 | * |
d945cb9c AC |
106 | * Our "hardware" write method. Data is coming from the ldisc which |
107 | * may be in a non sleeping state. We simply throw this at the other | |
108 | * end of the link as if we were an IRQ handler receiving stuff for | |
109 | * the other side of the pty/tty pair. | |
1da177e4 | 110 | */ |
d945cb9c | 111 | |
ac89a917 | 112 | static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c) |
1da177e4 LT |
113 | { |
114 | struct tty_struct *to = tty->link; | |
1da177e4 | 115 | |
d945cb9c | 116 | if (tty->stopped) |
1da177e4 | 117 | return 0; |
d945cb9c | 118 | |
d945cb9c AC |
119 | if (c > 0) { |
120 | /* Stuff the data into the input queue of the other end */ | |
121 | c = tty_insert_flip_string(to, buf, c); | |
122 | /* And shovel */ | |
123 | tty_flip_buffer_push(to); | |
124 | tty_wakeup(tty); | |
762faaed | 125 | } |
1da177e4 LT |
126 | return c; |
127 | } | |
128 | ||
d945cb9c AC |
129 | /** |
130 | * pty_write_room - write space | |
131 | * @tty: tty we are writing from | |
132 | * | |
133 | * Report how many bytes the ldisc can send into the queue for | |
134 | * the other device. | |
135 | */ | |
136 | ||
1da177e4 LT |
137 | static int pty_write_room(struct tty_struct *tty) |
138 | { | |
85dfd81d LT |
139 | if (tty->stopped) |
140 | return 0; | |
d945cb9c | 141 | return pty_space(tty->link); |
1da177e4 LT |
142 | } |
143 | ||
d945cb9c AC |
144 | /** |
145 | * pty_chars_in_buffer - characters currently in our tx queue | |
146 | * @tty: our tty | |
fe9cd962 | 147 | * |
d945cb9c AC |
148 | * Report how much we have in the transmit queue. As everything is |
149 | * instantly at the other end this is easy to implement. | |
1da177e4 | 150 | */ |
d945cb9c | 151 | |
1da177e4 LT |
152 | static int pty_chars_in_buffer(struct tty_struct *tty) |
153 | { | |
d945cb9c | 154 | return 0; |
1da177e4 LT |
155 | } |
156 | ||
157 | /* Set the lock flag on a pty */ | |
fe9cd962 | 158 | static int pty_set_lock(struct tty_struct *tty, int __user *arg) |
1da177e4 LT |
159 | { |
160 | int val; | |
fe9cd962 | 161 | if (get_user(val, arg)) |
1da177e4 LT |
162 | return -EFAULT; |
163 | if (val) | |
164 | set_bit(TTY_PTY_LOCK, &tty->flags); | |
165 | else | |
166 | clear_bit(TTY_PTY_LOCK, &tty->flags); | |
167 | return 0; | |
168 | } | |
169 | ||
170 | static void pty_flush_buffer(struct tty_struct *tty) | |
171 | { | |
172 | struct tty_struct *to = tty->link; | |
04f378b1 | 173 | unsigned long flags; |
fe9cd962 | 174 | |
1da177e4 LT |
175 | if (!to) |
176 | return; | |
d945cb9c | 177 | /* tty_buffer_flush(to); FIXME */ |
1da177e4 | 178 | if (to->packet) { |
04f378b1 | 179 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
1da177e4 LT |
180 | tty->ctrl_status |= TIOCPKT_FLUSHWRITE; |
181 | wake_up_interruptible(&to->read_wait); | |
04f378b1 | 182 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
1da177e4 LT |
183 | } |
184 | } | |
185 | ||
fe9cd962 | 186 | static int pty_open(struct tty_struct *tty, struct file *filp) |
1da177e4 LT |
187 | { |
188 | int retval = -ENODEV; | |
189 | ||
190 | if (!tty || !tty->link) | |
191 | goto out; | |
192 | ||
193 | retval = -EIO; | |
194 | if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) | |
195 | goto out; | |
196 | if (test_bit(TTY_PTY_LOCK, &tty->link->flags)) | |
197 | goto out; | |
198 | if (tty->link->count != 1) | |
199 | goto out; | |
200 | ||
201 | clear_bit(TTY_OTHER_CLOSED, &tty->link->flags); | |
202 | set_bit(TTY_THROTTLED, &tty->flags); | |
1da177e4 LT |
203 | retval = 0; |
204 | out: | |
205 | return retval; | |
206 | } | |
207 | ||
fe9cd962 AC |
208 | static void pty_set_termios(struct tty_struct *tty, |
209 | struct ktermios *old_termios) | |
1da177e4 | 210 | { |
fe9cd962 AC |
211 | tty->termios->c_cflag &= ~(CSIZE | PARENB); |
212 | tty->termios->c_cflag |= (CS8 | CREAD); | |
1da177e4 LT |
213 | } |
214 | ||
fc6f6238 AC |
215 | /** |
216 | * pty_do_resize - resize event | |
217 | * @tty: tty being resized | |
c774bda2 | 218 | * @ws: window size being set. |
fc6f6238 AC |
219 | * |
220 | * Update the termios variables and send the neccessary signals to | |
221 | * peform a terminal resize correctly | |
222 | */ | |
223 | ||
224 | int pty_resize(struct tty_struct *tty, struct winsize *ws) | |
225 | { | |
226 | struct pid *pgrp, *rpgrp; | |
227 | unsigned long flags; | |
228 | struct tty_struct *pty = tty->link; | |
229 | ||
230 | /* For a PTY we need to lock the tty side */ | |
231 | mutex_lock(&tty->termios_mutex); | |
232 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) | |
233 | goto done; | |
234 | ||
235 | /* Get the PID values and reference them so we can | |
236 | avoid holding the tty ctrl lock while sending signals. | |
237 | We need to lock these individually however. */ | |
238 | ||
239 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
240 | pgrp = get_pid(tty->pgrp); | |
241 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
242 | ||
243 | spin_lock_irqsave(&pty->ctrl_lock, flags); | |
244 | rpgrp = get_pid(pty->pgrp); | |
245 | spin_unlock_irqrestore(&pty->ctrl_lock, flags); | |
246 | ||
247 | if (pgrp) | |
248 | kill_pgrp(pgrp, SIGWINCH, 1); | |
249 | if (rpgrp != pgrp && rpgrp) | |
250 | kill_pgrp(rpgrp, SIGWINCH, 1); | |
251 | ||
252 | put_pid(pgrp); | |
253 | put_pid(rpgrp); | |
254 | ||
255 | tty->winsize = *ws; | |
256 | pty->winsize = *ws; /* Never used so will go away soon */ | |
257 | done: | |
258 | mutex_unlock(&tty->termios_mutex); | |
259 | return 0; | |
260 | } | |
261 | ||
bf970ee4 AC |
262 | static int pty_install(struct tty_driver *driver, struct tty_struct *tty) |
263 | { | |
264 | struct tty_struct *o_tty; | |
265 | int idx = tty->index; | |
266 | int retval; | |
267 | ||
268 | o_tty = alloc_tty_struct(); | |
269 | if (!o_tty) | |
270 | return -ENOMEM; | |
271 | if (!try_module_get(driver->other->owner)) { | |
272 | /* This cannot in fact currently happen */ | |
273 | free_tty_struct(o_tty); | |
274 | return -ENOMEM; | |
275 | } | |
276 | initialize_tty_struct(o_tty, driver->other, idx); | |
277 | ||
278 | /* We always use new tty termios data so we can do this | |
279 | the easy way .. */ | |
280 | retval = tty_init_termios(tty); | |
281 | if (retval) | |
282 | goto free_mem_out; | |
283 | ||
284 | retval = tty_init_termios(o_tty); | |
285 | if (retval) { | |
286 | tty_free_termios(tty); | |
287 | goto free_mem_out; | |
288 | } | |
fe9cd962 | 289 | |
bf970ee4 AC |
290 | /* |
291 | * Everything allocated ... set up the o_tty structure. | |
292 | */ | |
293 | driver->other->ttys[idx] = o_tty; | |
294 | tty_driver_kref_get(driver->other); | |
295 | if (driver->subtype == PTY_TYPE_MASTER) | |
296 | o_tty->count++; | |
297 | /* Establish the links in both directions */ | |
298 | tty->link = o_tty; | |
299 | o_tty->link = tty; | |
300 | ||
301 | tty_driver_kref_get(driver); | |
302 | tty->count++; | |
303 | driver->ttys[idx] = tty; | |
304 | return 0; | |
305 | free_mem_out: | |
306 | module_put(o_tty->driver->owner); | |
307 | free_tty_struct(o_tty); | |
308 | return -ENOMEM; | |
309 | } | |
310 | ||
311 | ||
b68e31d0 | 312 | static const struct tty_operations pty_ops = { |
bf970ee4 | 313 | .install = pty_install, |
1da177e4 LT |
314 | .open = pty_open, |
315 | .close = pty_close, | |
316 | .write = pty_write, | |
317 | .write_room = pty_write_room, | |
318 | .flush_buffer = pty_flush_buffer, | |
319 | .chars_in_buffer = pty_chars_in_buffer, | |
320 | .unthrottle = pty_unthrottle, | |
321 | .set_termios = pty_set_termios, | |
fc6f6238 | 322 | .resize = pty_resize |
1da177e4 LT |
323 | }; |
324 | ||
325 | /* Traditional BSD devices */ | |
326 | #ifdef CONFIG_LEGACY_PTYS | |
327 | static struct tty_driver *pty_driver, *pty_slave_driver; | |
328 | ||
329 | static int pty_bsd_ioctl(struct tty_struct *tty, struct file *file, | |
330 | unsigned int cmd, unsigned long arg) | |
331 | { | |
332 | switch (cmd) { | |
333 | case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */ | |
334 | return pty_set_lock(tty, (int __user *) arg); | |
335 | } | |
336 | return -ENOIOCTLCMD; | |
337 | } | |
338 | ||
dc8c8587 KS |
339 | static int legacy_count = CONFIG_LEGACY_PTY_COUNT; |
340 | module_param(legacy_count, int, 0); | |
341 | ||
3e8e88ca AC |
342 | static const struct tty_operations pty_ops_bsd = { |
343 | .open = pty_open, | |
344 | .close = pty_close, | |
345 | .write = pty_write, | |
346 | .write_room = pty_write_room, | |
347 | .flush_buffer = pty_flush_buffer, | |
348 | .chars_in_buffer = pty_chars_in_buffer, | |
349 | .unthrottle = pty_unthrottle, | |
350 | .set_termios = pty_set_termios, | |
351 | .ioctl = pty_bsd_ioctl, | |
fc6f6238 | 352 | .resize = pty_resize |
3e8e88ca AC |
353 | }; |
354 | ||
1da177e4 LT |
355 | static void __init legacy_pty_init(void) |
356 | { | |
dc8c8587 KS |
357 | if (legacy_count <= 0) |
358 | return; | |
1da177e4 | 359 | |
dc8c8587 | 360 | pty_driver = alloc_tty_driver(legacy_count); |
1da177e4 LT |
361 | if (!pty_driver) |
362 | panic("Couldn't allocate pty driver"); | |
363 | ||
dc8c8587 | 364 | pty_slave_driver = alloc_tty_driver(legacy_count); |
1da177e4 LT |
365 | if (!pty_slave_driver) |
366 | panic("Couldn't allocate pty slave driver"); | |
367 | ||
368 | pty_driver->owner = THIS_MODULE; | |
369 | pty_driver->driver_name = "pty_master"; | |
370 | pty_driver->name = "pty"; | |
1da177e4 LT |
371 | pty_driver->major = PTY_MASTER_MAJOR; |
372 | pty_driver->minor_start = 0; | |
373 | pty_driver->type = TTY_DRIVER_TYPE_PTY; | |
374 | pty_driver->subtype = PTY_TYPE_MASTER; | |
375 | pty_driver->init_termios = tty_std_termios; | |
376 | pty_driver->init_termios.c_iflag = 0; | |
377 | pty_driver->init_termios.c_oflag = 0; | |
378 | pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
379 | pty_driver->init_termios.c_lflag = 0; | |
606d099c AC |
380 | pty_driver->init_termios.c_ispeed = 38400; |
381 | pty_driver->init_termios.c_ospeed = 38400; | |
1da177e4 LT |
382 | pty_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW; |
383 | pty_driver->other = pty_slave_driver; | |
384 | tty_set_operations(pty_driver, &pty_ops); | |
1da177e4 LT |
385 | |
386 | pty_slave_driver->owner = THIS_MODULE; | |
387 | pty_slave_driver->driver_name = "pty_slave"; | |
388 | pty_slave_driver->name = "ttyp"; | |
1da177e4 LT |
389 | pty_slave_driver->major = PTY_SLAVE_MAJOR; |
390 | pty_slave_driver->minor_start = 0; | |
391 | pty_slave_driver->type = TTY_DRIVER_TYPE_PTY; | |
392 | pty_slave_driver->subtype = PTY_TYPE_SLAVE; | |
393 | pty_slave_driver->init_termios = tty_std_termios; | |
394 | pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
606d099c AC |
395 | pty_slave_driver->init_termios.c_ispeed = 38400; |
396 | pty_slave_driver->init_termios.c_ospeed = 38400; | |
1da177e4 LT |
397 | pty_slave_driver->flags = TTY_DRIVER_RESET_TERMIOS | |
398 | TTY_DRIVER_REAL_RAW; | |
399 | pty_slave_driver->other = pty_driver; | |
400 | tty_set_operations(pty_slave_driver, &pty_ops); | |
401 | ||
402 | if (tty_register_driver(pty_driver)) | |
403 | panic("Couldn't register pty driver"); | |
404 | if (tty_register_driver(pty_slave_driver)) | |
405 | panic("Couldn't register pty slave driver"); | |
406 | } | |
407 | #else | |
408 | static inline void legacy_pty_init(void) { } | |
409 | #endif | |
410 | ||
411 | /* Unix98 devices */ | |
412 | #ifdef CONFIG_UNIX98_PTYS | |
413 | /* | |
414 | * sysctl support for setting limits on the number of Unix98 ptys allocated. | |
415 | * Otherwise one can eat up all kernel memory by opening /dev/ptmx repeatedly. | |
416 | */ | |
417 | int pty_limit = NR_UNIX98_PTY_DEFAULT; | |
fe9cd962 | 418 | static int pty_limit_min; |
1da177e4 | 419 | static int pty_limit_max = NR_UNIX98_PTY_MAX; |
fe9cd962 | 420 | static int pty_count; |
1da177e4 | 421 | |
d81ed103 AC |
422 | static struct cdev ptmx_cdev; |
423 | ||
35834ca1 | 424 | static struct ctl_table pty_table[] = { |
1da177e4 LT |
425 | { |
426 | .ctl_name = PTY_MAX, | |
427 | .procname = "max", | |
428 | .maxlen = sizeof(int), | |
429 | .mode = 0644, | |
430 | .data = &pty_limit, | |
431 | .proc_handler = &proc_dointvec_minmax, | |
432 | .strategy = &sysctl_intvec, | |
433 | .extra1 = &pty_limit_min, | |
434 | .extra2 = &pty_limit_max, | |
435 | }, { | |
436 | .ctl_name = PTY_NR, | |
437 | .procname = "nr", | |
438 | .maxlen = sizeof(int), | |
439 | .mode = 0444, | |
bf970ee4 | 440 | .data = &pty_count, |
1da177e4 LT |
441 | .proc_handler = &proc_dointvec, |
442 | }, { | |
443 | .ctl_name = 0 | |
444 | } | |
445 | }; | |
446 | ||
35834ca1 EB |
447 | static struct ctl_table pty_kern_table[] = { |
448 | { | |
449 | .ctl_name = KERN_PTY, | |
450 | .procname = "pty", | |
451 | .mode = 0555, | |
452 | .child = pty_table, | |
453 | }, | |
454 | {} | |
455 | }; | |
456 | ||
457 | static struct ctl_table pty_root_table[] = { | |
458 | { | |
459 | .ctl_name = CTL_KERN, | |
460 | .procname = "kernel", | |
461 | .mode = 0555, | |
462 | .child = pty_kern_table, | |
463 | }, | |
464 | {} | |
465 | }; | |
466 | ||
467 | ||
1da177e4 LT |
468 | static int pty_unix98_ioctl(struct tty_struct *tty, struct file *file, |
469 | unsigned int cmd, unsigned long arg) | |
470 | { | |
471 | switch (cmd) { | |
472 | case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */ | |
473 | return pty_set_lock(tty, (int __user *)arg); | |
474 | case TIOCGPTN: /* Get PT Number */ | |
475 | return put_user(tty->index, (unsigned int __user *)arg); | |
476 | } | |
477 | ||
478 | return -ENOIOCTLCMD; | |
479 | } | |
480 | ||
99f1fe18 AC |
481 | /** |
482 | * ptm_unix98_lookup - find a pty master | |
483 | * @driver: ptm driver | |
484 | * @idx: tty index | |
485 | * | |
486 | * Look up a pty master device. Called under the tty_mutex for now. | |
487 | * This provides our locking. | |
488 | */ | |
489 | ||
15f1a633 SB |
490 | static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver, |
491 | struct inode *ptm_inode, int idx) | |
99f1fe18 | 492 | { |
15f1a633 | 493 | struct tty_struct *tty = devpts_get_tty(ptm_inode, idx); |
99f1fe18 AC |
494 | if (tty) |
495 | tty = tty->link; | |
496 | return tty; | |
497 | } | |
498 | ||
499 | /** | |
500 | * pts_unix98_lookup - find a pty slave | |
501 | * @driver: pts driver | |
502 | * @idx: tty index | |
503 | * | |
504 | * Look up a pty master device. Called under the tty_mutex for now. | |
505 | * This provides our locking. | |
506 | */ | |
507 | ||
15f1a633 SB |
508 | static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver, |
509 | struct inode *pts_inode, int idx) | |
99f1fe18 | 510 | { |
15f1a633 | 511 | struct tty_struct *tty = devpts_get_tty(pts_inode, idx); |
99f1fe18 AC |
512 | /* Master must be open before slave */ |
513 | if (!tty) | |
514 | return ERR_PTR(-EIO); | |
515 | return tty; | |
516 | } | |
517 | ||
bf970ee4 | 518 | static void pty_unix98_shutdown(struct tty_struct *tty) |
feebed65 AC |
519 | { |
520 | /* We have our own method as we don't use the tty index */ | |
521 | kfree(tty->termios); | |
feebed65 AC |
522 | } |
523 | ||
8b0a88d5 AC |
524 | /* We have no need to install and remove our tty objects as devpts does all |
525 | the work for us */ | |
526 | ||
bf970ee4 | 527 | static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 | 528 | { |
bf970ee4 AC |
529 | struct tty_struct *o_tty; |
530 | int idx = tty->index; | |
531 | ||
532 | o_tty = alloc_tty_struct(); | |
533 | if (!o_tty) | |
534 | return -ENOMEM; | |
535 | if (!try_module_get(driver->other->owner)) { | |
536 | /* This cannot in fact currently happen */ | |
537 | free_tty_struct(o_tty); | |
538 | return -ENOMEM; | |
539 | } | |
540 | initialize_tty_struct(o_tty, driver->other, idx); | |
541 | ||
8dff04ea | 542 | tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL); |
bf970ee4 AC |
543 | if (tty->termios == NULL) |
544 | goto free_mem_out; | |
545 | *tty->termios = driver->init_termios; | |
8dff04ea AC |
546 | tty->termios_locked = tty->termios + 1; |
547 | ||
548 | o_tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL); | |
bf970ee4 AC |
549 | if (o_tty->termios == NULL) |
550 | goto free_mem_out; | |
551 | *o_tty->termios = driver->other->init_termios; | |
8dff04ea | 552 | o_tty->termios_locked = o_tty->termios + 1; |
bf970ee4 AC |
553 | |
554 | tty_driver_kref_get(driver->other); | |
555 | if (driver->subtype == PTY_TYPE_MASTER) | |
556 | o_tty->count++; | |
557 | /* Establish the links in both directions */ | |
558 | tty->link = o_tty; | |
559 | o_tty->link = tty; | |
560 | /* | |
561 | * All structures have been allocated, so now we install them. | |
562 | * Failures after this point use release_tty to clean up, so | |
563 | * there's no need to null out the local pointers. | |
564 | */ | |
565 | tty_driver_kref_get(driver); | |
566 | tty->count++; | |
567 | pty_count++; | |
8b0a88d5 | 568 | return 0; |
bf970ee4 | 569 | free_mem_out: |
8dff04ea | 570 | kfree(o_tty->termios); |
bf970ee4 AC |
571 | module_put(o_tty->driver->owner); |
572 | free_tty_struct(o_tty); | |
8dff04ea | 573 | kfree(tty->termios); |
bf970ee4 | 574 | return -ENOMEM; |
8b0a88d5 AC |
575 | } |
576 | ||
bf970ee4 | 577 | static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 | 578 | { |
bf970ee4 | 579 | pty_count--; |
8b0a88d5 AC |
580 | } |
581 | ||
feebed65 | 582 | static const struct tty_operations ptm_unix98_ops = { |
99f1fe18 | 583 | .lookup = ptm_unix98_lookup, |
bf970ee4 AC |
584 | .install = pty_unix98_install, |
585 | .remove = pty_unix98_remove, | |
3e8e88ca AC |
586 | .open = pty_open, |
587 | .close = pty_close, | |
588 | .write = pty_write, | |
589 | .write_room = pty_write_room, | |
590 | .flush_buffer = pty_flush_buffer, | |
591 | .chars_in_buffer = pty_chars_in_buffer, | |
592 | .unthrottle = pty_unthrottle, | |
593 | .set_termios = pty_set_termios, | |
feebed65 | 594 | .ioctl = pty_unix98_ioctl, |
fc6f6238 AC |
595 | .shutdown = pty_unix98_shutdown, |
596 | .resize = pty_resize | |
3e8e88ca AC |
597 | }; |
598 | ||
99f1fe18 AC |
599 | static const struct tty_operations pty_unix98_ops = { |
600 | .lookup = pts_unix98_lookup, | |
bf970ee4 AC |
601 | .install = pty_unix98_install, |
602 | .remove = pty_unix98_remove, | |
99f1fe18 AC |
603 | .open = pty_open, |
604 | .close = pty_close, | |
605 | .write = pty_write, | |
606 | .write_room = pty_write_room, | |
607 | .flush_buffer = pty_flush_buffer, | |
608 | .chars_in_buffer = pty_chars_in_buffer, | |
609 | .unthrottle = pty_unthrottle, | |
610 | .set_termios = pty_set_termios, | |
bf970ee4 | 611 | .shutdown = pty_unix98_shutdown |
99f1fe18 | 612 | }; |
d81ed103 AC |
613 | |
614 | /** | |
615 | * ptmx_open - open a unix 98 pty master | |
616 | * @inode: inode of device file | |
617 | * @filp: file pointer to tty | |
618 | * | |
619 | * Allocate a unix98 pty master device from the ptmx driver. | |
620 | * | |
621 | * Locking: tty_mutex protects the init_dev work. tty->count should | |
622 | * protect the rest. | |
623 | * allocated_ptys_lock handles the list of free pty numbers | |
624 | */ | |
625 | ||
626 | static int __ptmx_open(struct inode *inode, struct file *filp) | |
627 | { | |
628 | struct tty_struct *tty; | |
629 | int retval; | |
630 | int index; | |
631 | ||
632 | nonseekable_open(inode, filp); | |
633 | ||
634 | /* find a device that is not in use. */ | |
15f1a633 | 635 | index = devpts_new_index(inode); |
d81ed103 AC |
636 | if (index < 0) |
637 | return index; | |
638 | ||
639 | mutex_lock(&tty_mutex); | |
73ec06fc | 640 | tty = tty_init_dev(ptm_driver, index, 1); |
d81ed103 AC |
641 | mutex_unlock(&tty_mutex); |
642 | ||
73ec06fc AC |
643 | if (IS_ERR(tty)) { |
644 | retval = PTR_ERR(tty); | |
d81ed103 | 645 | goto out; |
73ec06fc | 646 | } |
d81ed103 AC |
647 | |
648 | set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ | |
649 | filp->private_data = tty; | |
650 | file_move(filp, &tty->tty_files); | |
651 | ||
15f1a633 | 652 | retval = devpts_pty_new(inode, tty->link); |
d81ed103 AC |
653 | if (retval) |
654 | goto out1; | |
655 | ||
656 | retval = ptm_driver->ops->open(tty, filp); | |
657 | if (!retval) | |
658 | return 0; | |
659 | out1: | |
660 | tty_release_dev(filp); | |
661 | return retval; | |
662 | out: | |
15f1a633 | 663 | devpts_kill_index(inode, index); |
d81ed103 AC |
664 | return retval; |
665 | } | |
666 | ||
667 | static int ptmx_open(struct inode *inode, struct file *filp) | |
668 | { | |
669 | int ret; | |
670 | ||
671 | lock_kernel(); | |
672 | ret = __ptmx_open(inode, filp); | |
673 | unlock_kernel(); | |
674 | return ret; | |
675 | } | |
676 | ||
677 | static struct file_operations ptmx_fops; | |
678 | ||
1da177e4 LT |
679 | static void __init unix98_pty_init(void) |
680 | { | |
1da177e4 LT |
681 | ptm_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX); |
682 | if (!ptm_driver) | |
683 | panic("Couldn't allocate Unix98 ptm driver"); | |
684 | pts_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX); | |
685 | if (!pts_driver) | |
686 | panic("Couldn't allocate Unix98 pts driver"); | |
687 | ||
688 | ptm_driver->owner = THIS_MODULE; | |
689 | ptm_driver->driver_name = "pty_master"; | |
690 | ptm_driver->name = "ptm"; | |
691 | ptm_driver->major = UNIX98_PTY_MASTER_MAJOR; | |
692 | ptm_driver->minor_start = 0; | |
693 | ptm_driver->type = TTY_DRIVER_TYPE_PTY; | |
694 | ptm_driver->subtype = PTY_TYPE_MASTER; | |
695 | ptm_driver->init_termios = tty_std_termios; | |
696 | ptm_driver->init_termios.c_iflag = 0; | |
697 | ptm_driver->init_termios.c_oflag = 0; | |
698 | ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
699 | ptm_driver->init_termios.c_lflag = 0; | |
606d099c AC |
700 | ptm_driver->init_termios.c_ispeed = 38400; |
701 | ptm_driver->init_termios.c_ospeed = 38400; | |
1da177e4 | 702 | ptm_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | |
331b8319 | 703 | TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM; |
1da177e4 | 704 | ptm_driver->other = pts_driver; |
feebed65 | 705 | tty_set_operations(ptm_driver, &ptm_unix98_ops); |
1da177e4 LT |
706 | |
707 | pts_driver->owner = THIS_MODULE; | |
708 | pts_driver->driver_name = "pty_slave"; | |
709 | pts_driver->name = "pts"; | |
710 | pts_driver->major = UNIX98_PTY_SLAVE_MAJOR; | |
711 | pts_driver->minor_start = 0; | |
712 | pts_driver->type = TTY_DRIVER_TYPE_PTY; | |
713 | pts_driver->subtype = PTY_TYPE_SLAVE; | |
714 | pts_driver->init_termios = tty_std_termios; | |
715 | pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
606d099c AC |
716 | pts_driver->init_termios.c_ispeed = 38400; |
717 | pts_driver->init_termios.c_ospeed = 38400; | |
1da177e4 | 718 | pts_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | |
331b8319 | 719 | TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM; |
1da177e4 | 720 | pts_driver->other = ptm_driver; |
99f1fe18 | 721 | tty_set_operations(pts_driver, &pty_unix98_ops); |
fe9cd962 | 722 | |
1da177e4 LT |
723 | if (tty_register_driver(ptm_driver)) |
724 | panic("Couldn't register Unix98 ptm driver"); | |
725 | if (tty_register_driver(pts_driver)) | |
726 | panic("Couldn't register Unix98 pts driver"); | |
727 | ||
fe9cd962 | 728 | register_sysctl_table(pty_root_table); |
d81ed103 AC |
729 | |
730 | /* Now create the /dev/ptmx special device */ | |
731 | tty_default_fops(&ptmx_fops); | |
732 | ptmx_fops.open = ptmx_open; | |
733 | ||
734 | cdev_init(&ptmx_cdev, &ptmx_fops); | |
735 | if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) || | |
736 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0) | |
737 | panic("Couldn't register /dev/ptmx driver\n"); | |
738 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx"); | |
1da177e4 | 739 | } |
d81ed103 | 740 | |
1da177e4 LT |
741 | #else |
742 | static inline void unix98_pty_init(void) { } | |
743 | #endif | |
744 | ||
745 | static int __init pty_init(void) | |
746 | { | |
747 | legacy_pty_init(); | |
748 | unix98_pty_init(); | |
749 | return 0; | |
750 | } | |
751 | module_init(pty_init); |