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> | |
21 | #include <linux/string.h> | |
22 | #include <linux/major.h> | |
23 | #include <linux/mm.h> | |
24 | #include <linux/init.h> | |
1da177e4 | 25 | #include <linux/sysctl.h> |
d81ed103 | 26 | #include <linux/device.h> |
fe9cd962 | 27 | #include <linux/uaccess.h> |
1da177e4 LT |
28 | #include <linux/bitops.h> |
29 | #include <linux/devpts_fs.h> | |
30 | ||
fe9cd962 AC |
31 | #include <asm/system.h> |
32 | ||
1da177e4 | 33 | #ifdef CONFIG_UNIX98_PTYS |
da2bdf9a | 34 | static struct tty_driver *ptm_driver; |
1da177e4 LT |
35 | static struct tty_driver *pts_driver; |
36 | #endif | |
37 | ||
fe9cd962 | 38 | static void pty_close(struct tty_struct *tty, struct file *filp) |
1da177e4 | 39 | { |
fe9cd962 AC |
40 | BUG_ON(!tty); |
41 | if (tty->driver->subtype == PTY_TYPE_MASTER) | |
42 | WARN_ON(tty->count > 1); | |
43 | else { | |
1da177e4 LT |
44 | if (tty->count > 2) |
45 | return; | |
46 | } | |
47 | wake_up_interruptible(&tty->read_wait); | |
48 | wake_up_interruptible(&tty->write_wait); | |
49 | tty->packet = 0; | |
50 | if (!tty->link) | |
51 | return; | |
52 | tty->link->packet = 0; | |
53 | set_bit(TTY_OTHER_CLOSED, &tty->link->flags); | |
54 | wake_up_interruptible(&tty->link->read_wait); | |
55 | wake_up_interruptible(&tty->link->write_wait); | |
56 | if (tty->driver->subtype == PTY_TYPE_MASTER) { | |
57 | set_bit(TTY_OTHER_CLOSED, &tty->flags); | |
58 | #ifdef CONFIG_UNIX98_PTYS | |
59 | if (tty->driver == ptm_driver) | |
15f1a633 | 60 | devpts_pty_kill(tty->link); |
1da177e4 LT |
61 | #endif |
62 | tty_vhangup(tty->link); | |
63 | } | |
64 | } | |
65 | ||
66 | /* | |
67 | * The unthrottle routine is called by the line discipline to signal | |
68 | * that it can receive more characters. For PTY's, the TTY_THROTTLED | |
69 | * flag is always set, to force the line discipline to always call the | |
fe9cd962 | 70 | * unthrottle routine when there are fewer than TTY_THRESHOLD_UNTHROTTLE |
1da177e4 LT |
71 | * characters in the queue. This is necessary since each time this |
72 | * happens, we need to wake up any sleeping processes that could be | |
73 | * (1) trying to send data to the pty, or (2) waiting in wait_until_sent() | |
74 | * for the pty buffer to be drained. | |
75 | */ | |
fe9cd962 | 76 | static void pty_unthrottle(struct tty_struct *tty) |
1da177e4 | 77 | { |
d945cb9c | 78 | tty_wakeup(tty->link); |
1da177e4 LT |
79 | set_bit(TTY_THROTTLED, &tty->flags); |
80 | } | |
81 | ||
d945cb9c AC |
82 | /** |
83 | * pty_space - report space left for writing | |
84 | * @to: tty we are writing into | |
1da177e4 | 85 | * |
d945cb9c AC |
86 | * The tty buffers allow 64K but we sneak a peak and clip at 8K this |
87 | * allows a lot of overspill room for echo and other fun messes to | |
88 | * be handled properly | |
89 | */ | |
90 | ||
91 | static int pty_space(struct tty_struct *to) | |
92 | { | |
93 | int n = 8192 - to->buf.memory_used; | |
94 | if (n < 0) | |
95 | return 0; | |
96 | return n; | |
97 | } | |
98 | ||
99 | /** | |
100 | * pty_write - write to a pty | |
101 | * @tty: the tty we write from | |
102 | * @buf: kernel buffer of data | |
103 | * @count: bytes to write | |
762faaed | 104 | * |
d945cb9c AC |
105 | * Our "hardware" write method. Data is coming from the ldisc which |
106 | * may be in a non sleeping state. We simply throw this at the other | |
107 | * end of the link as if we were an IRQ handler receiving stuff for | |
108 | * the other side of the pty/tty pair. | |
1da177e4 | 109 | */ |
d945cb9c | 110 | |
fe9cd962 AC |
111 | static int pty_write(struct tty_struct *tty, const unsigned char *buf, |
112 | int count) | |
1da177e4 LT |
113 | { |
114 | struct tty_struct *to = tty->link; | |
d945cb9c | 115 | int c; |
1da177e4 | 116 | |
d945cb9c | 117 | if (tty->stopped) |
1da177e4 | 118 | return 0; |
d945cb9c AC |
119 | |
120 | /* This isn't locked but our 8K is quite sloppy so no | |
121 | big deal */ | |
122 | ||
123 | c = pty_space(to); | |
124 | if (c > count) | |
125 | c = count; | |
126 | if (c > 0) { | |
127 | /* Stuff the data into the input queue of the other end */ | |
128 | c = tty_insert_flip_string(to, buf, c); | |
129 | /* And shovel */ | |
130 | tty_flip_buffer_push(to); | |
131 | tty_wakeup(tty); | |
762faaed | 132 | } |
1da177e4 LT |
133 | return c; |
134 | } | |
135 | ||
d945cb9c AC |
136 | /** |
137 | * pty_write_room - write space | |
138 | * @tty: tty we are writing from | |
139 | * | |
140 | * Report how many bytes the ldisc can send into the queue for | |
141 | * the other device. | |
142 | */ | |
143 | ||
1da177e4 LT |
144 | static int pty_write_room(struct tty_struct *tty) |
145 | { | |
d945cb9c | 146 | return pty_space(tty->link); |
1da177e4 LT |
147 | } |
148 | ||
d945cb9c AC |
149 | /** |
150 | * pty_chars_in_buffer - characters currently in our tx queue | |
151 | * @tty: our tty | |
fe9cd962 | 152 | * |
d945cb9c AC |
153 | * Report how much we have in the transmit queue. As everything is |
154 | * instantly at the other end this is easy to implement. | |
1da177e4 | 155 | */ |
d945cb9c | 156 | |
1da177e4 LT |
157 | static int pty_chars_in_buffer(struct tty_struct *tty) |
158 | { | |
d945cb9c | 159 | return 0; |
1da177e4 LT |
160 | } |
161 | ||
162 | /* Set the lock flag on a pty */ | |
fe9cd962 | 163 | static int pty_set_lock(struct tty_struct *tty, int __user *arg) |
1da177e4 LT |
164 | { |
165 | int val; | |
fe9cd962 | 166 | if (get_user(val, arg)) |
1da177e4 LT |
167 | return -EFAULT; |
168 | if (val) | |
169 | set_bit(TTY_PTY_LOCK, &tty->flags); | |
170 | else | |
171 | clear_bit(TTY_PTY_LOCK, &tty->flags); | |
172 | return 0; | |
173 | } | |
174 | ||
175 | static void pty_flush_buffer(struct tty_struct *tty) | |
176 | { | |
177 | struct tty_struct *to = tty->link; | |
04f378b1 | 178 | unsigned long flags; |
fe9cd962 | 179 | |
1da177e4 LT |
180 | if (!to) |
181 | return; | |
d945cb9c | 182 | /* tty_buffer_flush(to); FIXME */ |
1da177e4 | 183 | if (to->packet) { |
04f378b1 | 184 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
1da177e4 LT |
185 | tty->ctrl_status |= TIOCPKT_FLUSHWRITE; |
186 | wake_up_interruptible(&to->read_wait); | |
04f378b1 | 187 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
1da177e4 LT |
188 | } |
189 | } | |
190 | ||
fe9cd962 | 191 | static int pty_open(struct tty_struct *tty, struct file *filp) |
1da177e4 LT |
192 | { |
193 | int retval = -ENODEV; | |
194 | ||
195 | if (!tty || !tty->link) | |
196 | goto out; | |
197 | ||
198 | retval = -EIO; | |
199 | if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) | |
200 | goto out; | |
201 | if (test_bit(TTY_PTY_LOCK, &tty->link->flags)) | |
202 | goto out; | |
203 | if (tty->link->count != 1) | |
204 | goto out; | |
205 | ||
206 | clear_bit(TTY_OTHER_CLOSED, &tty->link->flags); | |
207 | set_bit(TTY_THROTTLED, &tty->flags); | |
1da177e4 LT |
208 | retval = 0; |
209 | out: | |
210 | return retval; | |
211 | } | |
212 | ||
fe9cd962 AC |
213 | static void pty_set_termios(struct tty_struct *tty, |
214 | struct ktermios *old_termios) | |
1da177e4 | 215 | { |
fe9cd962 AC |
216 | tty->termios->c_cflag &= ~(CSIZE | PARENB); |
217 | tty->termios->c_cflag |= (CS8 | CREAD); | |
1da177e4 LT |
218 | } |
219 | ||
fc6f6238 AC |
220 | /** |
221 | * pty_do_resize - resize event | |
222 | * @tty: tty being resized | |
c774bda2 | 223 | * @ws: window size being set. |
fc6f6238 AC |
224 | * |
225 | * Update the termios variables and send the neccessary signals to | |
226 | * peform a terminal resize correctly | |
227 | */ | |
228 | ||
229 | int pty_resize(struct tty_struct *tty, struct winsize *ws) | |
230 | { | |
231 | struct pid *pgrp, *rpgrp; | |
232 | unsigned long flags; | |
233 | struct tty_struct *pty = tty->link; | |
234 | ||
235 | /* For a PTY we need to lock the tty side */ | |
236 | mutex_lock(&tty->termios_mutex); | |
237 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) | |
238 | goto done; | |
239 | ||
240 | /* Get the PID values and reference them so we can | |
241 | avoid holding the tty ctrl lock while sending signals. | |
242 | We need to lock these individually however. */ | |
243 | ||
244 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
245 | pgrp = get_pid(tty->pgrp); | |
246 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
247 | ||
248 | spin_lock_irqsave(&pty->ctrl_lock, flags); | |
249 | rpgrp = get_pid(pty->pgrp); | |
250 | spin_unlock_irqrestore(&pty->ctrl_lock, flags); | |
251 | ||
252 | if (pgrp) | |
253 | kill_pgrp(pgrp, SIGWINCH, 1); | |
254 | if (rpgrp != pgrp && rpgrp) | |
255 | kill_pgrp(rpgrp, SIGWINCH, 1); | |
256 | ||
257 | put_pid(pgrp); | |
258 | put_pid(rpgrp); | |
259 | ||
260 | tty->winsize = *ws; | |
261 | pty->winsize = *ws; /* Never used so will go away soon */ | |
262 | done: | |
263 | mutex_unlock(&tty->termios_mutex); | |
264 | return 0; | |
265 | } | |
266 | ||
bf970ee4 AC |
267 | static int pty_install(struct tty_driver *driver, struct tty_struct *tty) |
268 | { | |
269 | struct tty_struct *o_tty; | |
270 | int idx = tty->index; | |
271 | int retval; | |
272 | ||
273 | o_tty = alloc_tty_struct(); | |
274 | if (!o_tty) | |
275 | return -ENOMEM; | |
276 | if (!try_module_get(driver->other->owner)) { | |
277 | /* This cannot in fact currently happen */ | |
278 | free_tty_struct(o_tty); | |
279 | return -ENOMEM; | |
280 | } | |
281 | initialize_tty_struct(o_tty, driver->other, idx); | |
282 | ||
283 | /* We always use new tty termios data so we can do this | |
284 | the easy way .. */ | |
285 | retval = tty_init_termios(tty); | |
286 | if (retval) | |
287 | goto free_mem_out; | |
288 | ||
289 | retval = tty_init_termios(o_tty); | |
290 | if (retval) { | |
291 | tty_free_termios(tty); | |
292 | goto free_mem_out; | |
293 | } | |
fe9cd962 | 294 | |
bf970ee4 AC |
295 | /* |
296 | * Everything allocated ... set up the o_tty structure. | |
297 | */ | |
298 | driver->other->ttys[idx] = o_tty; | |
299 | tty_driver_kref_get(driver->other); | |
300 | if (driver->subtype == PTY_TYPE_MASTER) | |
301 | o_tty->count++; | |
302 | /* Establish the links in both directions */ | |
303 | tty->link = o_tty; | |
304 | o_tty->link = tty; | |
305 | ||
306 | tty_driver_kref_get(driver); | |
307 | tty->count++; | |
308 | driver->ttys[idx] = tty; | |
309 | return 0; | |
310 | free_mem_out: | |
311 | module_put(o_tty->driver->owner); | |
312 | free_tty_struct(o_tty); | |
313 | return -ENOMEM; | |
314 | } | |
315 | ||
316 | ||
b68e31d0 | 317 | static const struct tty_operations pty_ops = { |
bf970ee4 | 318 | .install = pty_install, |
1da177e4 LT |
319 | .open = pty_open, |
320 | .close = pty_close, | |
321 | .write = pty_write, | |
322 | .write_room = pty_write_room, | |
323 | .flush_buffer = pty_flush_buffer, | |
324 | .chars_in_buffer = pty_chars_in_buffer, | |
325 | .unthrottle = pty_unthrottle, | |
326 | .set_termios = pty_set_termios, | |
fc6f6238 | 327 | .resize = pty_resize |
1da177e4 LT |
328 | }; |
329 | ||
330 | /* Traditional BSD devices */ | |
331 | #ifdef CONFIG_LEGACY_PTYS | |
332 | static struct tty_driver *pty_driver, *pty_slave_driver; | |
333 | ||
334 | static int pty_bsd_ioctl(struct tty_struct *tty, struct file *file, | |
335 | unsigned int cmd, unsigned long arg) | |
336 | { | |
337 | switch (cmd) { | |
338 | case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */ | |
339 | return pty_set_lock(tty, (int __user *) arg); | |
340 | } | |
341 | return -ENOIOCTLCMD; | |
342 | } | |
343 | ||
dc8c8587 KS |
344 | static int legacy_count = CONFIG_LEGACY_PTY_COUNT; |
345 | module_param(legacy_count, int, 0); | |
346 | ||
3e8e88ca AC |
347 | static const struct tty_operations pty_ops_bsd = { |
348 | .open = pty_open, | |
349 | .close = pty_close, | |
350 | .write = pty_write, | |
351 | .write_room = pty_write_room, | |
352 | .flush_buffer = pty_flush_buffer, | |
353 | .chars_in_buffer = pty_chars_in_buffer, | |
354 | .unthrottle = pty_unthrottle, | |
355 | .set_termios = pty_set_termios, | |
356 | .ioctl = pty_bsd_ioctl, | |
fc6f6238 | 357 | .resize = pty_resize |
3e8e88ca AC |
358 | }; |
359 | ||
1da177e4 LT |
360 | static void __init legacy_pty_init(void) |
361 | { | |
dc8c8587 KS |
362 | if (legacy_count <= 0) |
363 | return; | |
1da177e4 | 364 | |
dc8c8587 | 365 | pty_driver = alloc_tty_driver(legacy_count); |
1da177e4 LT |
366 | if (!pty_driver) |
367 | panic("Couldn't allocate pty driver"); | |
368 | ||
dc8c8587 | 369 | pty_slave_driver = alloc_tty_driver(legacy_count); |
1da177e4 LT |
370 | if (!pty_slave_driver) |
371 | panic("Couldn't allocate pty slave driver"); | |
372 | ||
373 | pty_driver->owner = THIS_MODULE; | |
374 | pty_driver->driver_name = "pty_master"; | |
375 | pty_driver->name = "pty"; | |
1da177e4 LT |
376 | pty_driver->major = PTY_MASTER_MAJOR; |
377 | pty_driver->minor_start = 0; | |
378 | pty_driver->type = TTY_DRIVER_TYPE_PTY; | |
379 | pty_driver->subtype = PTY_TYPE_MASTER; | |
380 | pty_driver->init_termios = tty_std_termios; | |
381 | pty_driver->init_termios.c_iflag = 0; | |
382 | pty_driver->init_termios.c_oflag = 0; | |
383 | pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
384 | pty_driver->init_termios.c_lflag = 0; | |
606d099c AC |
385 | pty_driver->init_termios.c_ispeed = 38400; |
386 | pty_driver->init_termios.c_ospeed = 38400; | |
1da177e4 LT |
387 | pty_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW; |
388 | pty_driver->other = pty_slave_driver; | |
389 | tty_set_operations(pty_driver, &pty_ops); | |
1da177e4 LT |
390 | |
391 | pty_slave_driver->owner = THIS_MODULE; | |
392 | pty_slave_driver->driver_name = "pty_slave"; | |
393 | pty_slave_driver->name = "ttyp"; | |
1da177e4 LT |
394 | pty_slave_driver->major = PTY_SLAVE_MAJOR; |
395 | pty_slave_driver->minor_start = 0; | |
396 | pty_slave_driver->type = TTY_DRIVER_TYPE_PTY; | |
397 | pty_slave_driver->subtype = PTY_TYPE_SLAVE; | |
398 | pty_slave_driver->init_termios = tty_std_termios; | |
399 | pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
606d099c AC |
400 | pty_slave_driver->init_termios.c_ispeed = 38400; |
401 | pty_slave_driver->init_termios.c_ospeed = 38400; | |
1da177e4 LT |
402 | pty_slave_driver->flags = TTY_DRIVER_RESET_TERMIOS | |
403 | TTY_DRIVER_REAL_RAW; | |
404 | pty_slave_driver->other = pty_driver; | |
405 | tty_set_operations(pty_slave_driver, &pty_ops); | |
406 | ||
407 | if (tty_register_driver(pty_driver)) | |
408 | panic("Couldn't register pty driver"); | |
409 | if (tty_register_driver(pty_slave_driver)) | |
410 | panic("Couldn't register pty slave driver"); | |
411 | } | |
412 | #else | |
413 | static inline void legacy_pty_init(void) { } | |
414 | #endif | |
415 | ||
416 | /* Unix98 devices */ | |
417 | #ifdef CONFIG_UNIX98_PTYS | |
418 | /* | |
419 | * sysctl support for setting limits on the number of Unix98 ptys allocated. | |
420 | * Otherwise one can eat up all kernel memory by opening /dev/ptmx repeatedly. | |
421 | */ | |
422 | int pty_limit = NR_UNIX98_PTY_DEFAULT; | |
fe9cd962 | 423 | static int pty_limit_min; |
1da177e4 | 424 | static int pty_limit_max = NR_UNIX98_PTY_MAX; |
fe9cd962 | 425 | static int pty_count; |
1da177e4 | 426 | |
d81ed103 AC |
427 | static struct cdev ptmx_cdev; |
428 | ||
35834ca1 | 429 | static struct ctl_table pty_table[] = { |
1da177e4 LT |
430 | { |
431 | .ctl_name = PTY_MAX, | |
432 | .procname = "max", | |
433 | .maxlen = sizeof(int), | |
434 | .mode = 0644, | |
435 | .data = &pty_limit, | |
436 | .proc_handler = &proc_dointvec_minmax, | |
437 | .strategy = &sysctl_intvec, | |
438 | .extra1 = &pty_limit_min, | |
439 | .extra2 = &pty_limit_max, | |
440 | }, { | |
441 | .ctl_name = PTY_NR, | |
442 | .procname = "nr", | |
443 | .maxlen = sizeof(int), | |
444 | .mode = 0444, | |
bf970ee4 | 445 | .data = &pty_count, |
1da177e4 LT |
446 | .proc_handler = &proc_dointvec, |
447 | }, { | |
448 | .ctl_name = 0 | |
449 | } | |
450 | }; | |
451 | ||
35834ca1 EB |
452 | static struct ctl_table pty_kern_table[] = { |
453 | { | |
454 | .ctl_name = KERN_PTY, | |
455 | .procname = "pty", | |
456 | .mode = 0555, | |
457 | .child = pty_table, | |
458 | }, | |
459 | {} | |
460 | }; | |
461 | ||
462 | static struct ctl_table pty_root_table[] = { | |
463 | { | |
464 | .ctl_name = CTL_KERN, | |
465 | .procname = "kernel", | |
466 | .mode = 0555, | |
467 | .child = pty_kern_table, | |
468 | }, | |
469 | {} | |
470 | }; | |
471 | ||
472 | ||
1da177e4 LT |
473 | static int pty_unix98_ioctl(struct tty_struct *tty, struct file *file, |
474 | unsigned int cmd, unsigned long arg) | |
475 | { | |
476 | switch (cmd) { | |
477 | case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */ | |
478 | return pty_set_lock(tty, (int __user *)arg); | |
479 | case TIOCGPTN: /* Get PT Number */ | |
480 | return put_user(tty->index, (unsigned int __user *)arg); | |
481 | } | |
482 | ||
483 | return -ENOIOCTLCMD; | |
484 | } | |
485 | ||
99f1fe18 AC |
486 | /** |
487 | * ptm_unix98_lookup - find a pty master | |
488 | * @driver: ptm driver | |
489 | * @idx: tty index | |
490 | * | |
491 | * Look up a pty master device. Called under the tty_mutex for now. | |
492 | * This provides our locking. | |
493 | */ | |
494 | ||
15f1a633 SB |
495 | static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver, |
496 | struct inode *ptm_inode, int idx) | |
99f1fe18 | 497 | { |
15f1a633 | 498 | struct tty_struct *tty = devpts_get_tty(ptm_inode, idx); |
99f1fe18 AC |
499 | if (tty) |
500 | tty = tty->link; | |
501 | return tty; | |
502 | } | |
503 | ||
504 | /** | |
505 | * pts_unix98_lookup - find a pty slave | |
506 | * @driver: pts driver | |
507 | * @idx: tty index | |
508 | * | |
509 | * Look up a pty master device. Called under the tty_mutex for now. | |
510 | * This provides our locking. | |
511 | */ | |
512 | ||
15f1a633 SB |
513 | static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver, |
514 | struct inode *pts_inode, int idx) | |
99f1fe18 | 515 | { |
15f1a633 | 516 | struct tty_struct *tty = devpts_get_tty(pts_inode, idx); |
99f1fe18 AC |
517 | /* Master must be open before slave */ |
518 | if (!tty) | |
519 | return ERR_PTR(-EIO); | |
520 | return tty; | |
521 | } | |
522 | ||
bf970ee4 | 523 | static void pty_unix98_shutdown(struct tty_struct *tty) |
feebed65 AC |
524 | { |
525 | /* We have our own method as we don't use the tty index */ | |
526 | kfree(tty->termios); | |
feebed65 AC |
527 | } |
528 | ||
8b0a88d5 AC |
529 | /* We have no need to install and remove our tty objects as devpts does all |
530 | the work for us */ | |
531 | ||
bf970ee4 | 532 | static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 | 533 | { |
bf970ee4 AC |
534 | struct tty_struct *o_tty; |
535 | int idx = tty->index; | |
536 | ||
537 | o_tty = alloc_tty_struct(); | |
538 | if (!o_tty) | |
539 | return -ENOMEM; | |
540 | if (!try_module_get(driver->other->owner)) { | |
541 | /* This cannot in fact currently happen */ | |
542 | free_tty_struct(o_tty); | |
543 | return -ENOMEM; | |
544 | } | |
545 | initialize_tty_struct(o_tty, driver->other, idx); | |
546 | ||
8dff04ea | 547 | tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL); |
bf970ee4 AC |
548 | if (tty->termios == NULL) |
549 | goto free_mem_out; | |
550 | *tty->termios = driver->init_termios; | |
8dff04ea AC |
551 | tty->termios_locked = tty->termios + 1; |
552 | ||
553 | o_tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL); | |
bf970ee4 AC |
554 | if (o_tty->termios == NULL) |
555 | goto free_mem_out; | |
556 | *o_tty->termios = driver->other->init_termios; | |
8dff04ea | 557 | o_tty->termios_locked = o_tty->termios + 1; |
bf970ee4 AC |
558 | |
559 | tty_driver_kref_get(driver->other); | |
560 | if (driver->subtype == PTY_TYPE_MASTER) | |
561 | o_tty->count++; | |
562 | /* Establish the links in both directions */ | |
563 | tty->link = o_tty; | |
564 | o_tty->link = tty; | |
565 | /* | |
566 | * All structures have been allocated, so now we install them. | |
567 | * Failures after this point use release_tty to clean up, so | |
568 | * there's no need to null out the local pointers. | |
569 | */ | |
570 | tty_driver_kref_get(driver); | |
571 | tty->count++; | |
572 | pty_count++; | |
8b0a88d5 | 573 | return 0; |
bf970ee4 | 574 | free_mem_out: |
8dff04ea | 575 | kfree(o_tty->termios); |
bf970ee4 AC |
576 | module_put(o_tty->driver->owner); |
577 | free_tty_struct(o_tty); | |
8dff04ea | 578 | kfree(tty->termios); |
bf970ee4 | 579 | return -ENOMEM; |
8b0a88d5 AC |
580 | } |
581 | ||
bf970ee4 | 582 | static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 | 583 | { |
bf970ee4 | 584 | pty_count--; |
8b0a88d5 AC |
585 | } |
586 | ||
feebed65 | 587 | static const struct tty_operations ptm_unix98_ops = { |
99f1fe18 | 588 | .lookup = ptm_unix98_lookup, |
bf970ee4 AC |
589 | .install = pty_unix98_install, |
590 | .remove = pty_unix98_remove, | |
3e8e88ca AC |
591 | .open = pty_open, |
592 | .close = pty_close, | |
593 | .write = pty_write, | |
594 | .write_room = pty_write_room, | |
595 | .flush_buffer = pty_flush_buffer, | |
596 | .chars_in_buffer = pty_chars_in_buffer, | |
597 | .unthrottle = pty_unthrottle, | |
598 | .set_termios = pty_set_termios, | |
feebed65 | 599 | .ioctl = pty_unix98_ioctl, |
fc6f6238 AC |
600 | .shutdown = pty_unix98_shutdown, |
601 | .resize = pty_resize | |
3e8e88ca AC |
602 | }; |
603 | ||
99f1fe18 AC |
604 | static const struct tty_operations pty_unix98_ops = { |
605 | .lookup = pts_unix98_lookup, | |
bf970ee4 AC |
606 | .install = pty_unix98_install, |
607 | .remove = pty_unix98_remove, | |
99f1fe18 AC |
608 | .open = pty_open, |
609 | .close = pty_close, | |
610 | .write = pty_write, | |
611 | .write_room = pty_write_room, | |
612 | .flush_buffer = pty_flush_buffer, | |
613 | .chars_in_buffer = pty_chars_in_buffer, | |
614 | .unthrottle = pty_unthrottle, | |
615 | .set_termios = pty_set_termios, | |
bf970ee4 | 616 | .shutdown = pty_unix98_shutdown |
99f1fe18 | 617 | }; |
d81ed103 AC |
618 | |
619 | /** | |
620 | * ptmx_open - open a unix 98 pty master | |
621 | * @inode: inode of device file | |
622 | * @filp: file pointer to tty | |
623 | * | |
624 | * Allocate a unix98 pty master device from the ptmx driver. | |
625 | * | |
626 | * Locking: tty_mutex protects the init_dev work. tty->count should | |
627 | * protect the rest. | |
628 | * allocated_ptys_lock handles the list of free pty numbers | |
629 | */ | |
630 | ||
631 | static int __ptmx_open(struct inode *inode, struct file *filp) | |
632 | { | |
633 | struct tty_struct *tty; | |
634 | int retval; | |
635 | int index; | |
636 | ||
637 | nonseekable_open(inode, filp); | |
638 | ||
639 | /* find a device that is not in use. */ | |
15f1a633 | 640 | index = devpts_new_index(inode); |
d81ed103 AC |
641 | if (index < 0) |
642 | return index; | |
643 | ||
644 | mutex_lock(&tty_mutex); | |
73ec06fc | 645 | tty = tty_init_dev(ptm_driver, index, 1); |
d81ed103 AC |
646 | mutex_unlock(&tty_mutex); |
647 | ||
73ec06fc AC |
648 | if (IS_ERR(tty)) { |
649 | retval = PTR_ERR(tty); | |
d81ed103 | 650 | goto out; |
73ec06fc | 651 | } |
d81ed103 AC |
652 | |
653 | set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ | |
654 | filp->private_data = tty; | |
655 | file_move(filp, &tty->tty_files); | |
656 | ||
15f1a633 | 657 | retval = devpts_pty_new(inode, tty->link); |
d81ed103 AC |
658 | if (retval) |
659 | goto out1; | |
660 | ||
661 | retval = ptm_driver->ops->open(tty, filp); | |
662 | if (!retval) | |
663 | return 0; | |
664 | out1: | |
665 | tty_release_dev(filp); | |
666 | return retval; | |
667 | out: | |
15f1a633 | 668 | devpts_kill_index(inode, index); |
d81ed103 AC |
669 | return retval; |
670 | } | |
671 | ||
672 | static int ptmx_open(struct inode *inode, struct file *filp) | |
673 | { | |
674 | int ret; | |
675 | ||
676 | lock_kernel(); | |
677 | ret = __ptmx_open(inode, filp); | |
678 | unlock_kernel(); | |
679 | return ret; | |
680 | } | |
681 | ||
682 | static struct file_operations ptmx_fops; | |
683 | ||
1da177e4 LT |
684 | static void __init unix98_pty_init(void) |
685 | { | |
1da177e4 LT |
686 | ptm_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX); |
687 | if (!ptm_driver) | |
688 | panic("Couldn't allocate Unix98 ptm driver"); | |
689 | pts_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX); | |
690 | if (!pts_driver) | |
691 | panic("Couldn't allocate Unix98 pts driver"); | |
692 | ||
693 | ptm_driver->owner = THIS_MODULE; | |
694 | ptm_driver->driver_name = "pty_master"; | |
695 | ptm_driver->name = "ptm"; | |
696 | ptm_driver->major = UNIX98_PTY_MASTER_MAJOR; | |
697 | ptm_driver->minor_start = 0; | |
698 | ptm_driver->type = TTY_DRIVER_TYPE_PTY; | |
699 | ptm_driver->subtype = PTY_TYPE_MASTER; | |
700 | ptm_driver->init_termios = tty_std_termios; | |
701 | ptm_driver->init_termios.c_iflag = 0; | |
702 | ptm_driver->init_termios.c_oflag = 0; | |
703 | ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
704 | ptm_driver->init_termios.c_lflag = 0; | |
606d099c AC |
705 | ptm_driver->init_termios.c_ispeed = 38400; |
706 | ptm_driver->init_termios.c_ospeed = 38400; | |
1da177e4 | 707 | ptm_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | |
331b8319 | 708 | TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM; |
1da177e4 | 709 | ptm_driver->other = pts_driver; |
feebed65 | 710 | tty_set_operations(ptm_driver, &ptm_unix98_ops); |
1da177e4 LT |
711 | |
712 | pts_driver->owner = THIS_MODULE; | |
713 | pts_driver->driver_name = "pty_slave"; | |
714 | pts_driver->name = "pts"; | |
715 | pts_driver->major = UNIX98_PTY_SLAVE_MAJOR; | |
716 | pts_driver->minor_start = 0; | |
717 | pts_driver->type = TTY_DRIVER_TYPE_PTY; | |
718 | pts_driver->subtype = PTY_TYPE_SLAVE; | |
719 | pts_driver->init_termios = tty_std_termios; | |
720 | pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
606d099c AC |
721 | pts_driver->init_termios.c_ispeed = 38400; |
722 | pts_driver->init_termios.c_ospeed = 38400; | |
1da177e4 | 723 | pts_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | |
331b8319 | 724 | TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM; |
1da177e4 | 725 | pts_driver->other = ptm_driver; |
99f1fe18 | 726 | tty_set_operations(pts_driver, &pty_unix98_ops); |
fe9cd962 | 727 | |
1da177e4 LT |
728 | if (tty_register_driver(ptm_driver)) |
729 | panic("Couldn't register Unix98 ptm driver"); | |
730 | if (tty_register_driver(pts_driver)) | |
731 | panic("Couldn't register Unix98 pts driver"); | |
732 | ||
fe9cd962 | 733 | register_sysctl_table(pty_root_table); |
d81ed103 AC |
734 | |
735 | /* Now create the /dev/ptmx special device */ | |
736 | tty_default_fops(&ptmx_fops); | |
737 | ptmx_fops.open = ptmx_open; | |
738 | ||
739 | cdev_init(&ptmx_cdev, &ptmx_fops); | |
740 | if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) || | |
741 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0) | |
742 | panic("Couldn't register /dev/ptmx driver\n"); | |
743 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx"); | |
1da177e4 | 744 | } |
d81ed103 | 745 | |
1da177e4 LT |
746 | #else |
747 | static inline void unix98_pty_init(void) { } | |
748 | #endif | |
749 | ||
750 | static int __init pty_init(void) | |
751 | { | |
752 | legacy_pty_init(); | |
753 | unix98_pty_init(); | |
754 | return 0; | |
755 | } | |
756 | module_init(pty_init); |