Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
1da177e4 LT |
2 | * Copyright (C) 1991, 1992 Linus Torvalds |
3 | * | |
4 | * Added support for a Unix98-style ptmx device. | |
5 | * -- C. Scott Ananian <cananian@alumni.princeton.edu>, 14-Jan-1998 | |
1da177e4 | 6 | * |
fe9cd962 AC |
7 | * When reading this code see also fs/devpts. In particular note that the |
8 | * driver_data field is used by the devpts side as a binding to the devpts | |
9 | * inode. | |
1da177e4 LT |
10 | */ |
11 | ||
fe9cd962 | 12 | #include <linux/module.h> |
1da177e4 LT |
13 | |
14 | #include <linux/errno.h> | |
1da177e4 LT |
15 | #include <linux/interrupt.h> |
16 | #include <linux/tty.h> | |
17 | #include <linux/tty_flip.h> | |
18 | #include <linux/fcntl.h> | |
d43c36dc | 19 | #include <linux/sched.h> |
1da177e4 LT |
20 | #include <linux/string.h> |
21 | #include <linux/major.h> | |
22 | #include <linux/mm.h> | |
23 | #include <linux/init.h> | |
d81ed103 | 24 | #include <linux/device.h> |
fe9cd962 | 25 | #include <linux/uaccess.h> |
1da177e4 LT |
26 | #include <linux/bitops.h> |
27 | #include <linux/devpts_fs.h> | |
5a0e3ad6 | 28 | #include <linux/slab.h> |
d739e65b | 29 | #include <linux/mutex.h> |
1da177e4 | 30 | |
fe9cd962 | 31 | |
1da177e4 | 32 | #ifdef CONFIG_UNIX98_PTYS |
da2bdf9a | 33 | static struct tty_driver *ptm_driver; |
1da177e4 | 34 | static struct tty_driver *pts_driver; |
d739e65b | 35 | static DEFINE_MUTEX(devpts_mutex); |
1da177e4 LT |
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; | |
d29f3ef3 | 50 | /* Review - krefs on tty_link ?? */ |
1da177e4 LT |
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); | |
ce1000dd | 59 | #ifdef CONFIG_UNIX98_PTYS |
d739e65b AC |
60 | if (tty->driver == ptm_driver) { |
61 | mutex_lock(&devpts_mutex); | |
ce1000dd | 62 | devpts_pty_kill(tty->link); |
d739e65b AC |
63 | mutex_unlock(&devpts_mutex); |
64 | } | |
ce1000dd | 65 | #endif |
b1d679af | 66 | tty_unlock(tty); |
11dbf203 | 67 | tty_vhangup(tty->link); |
b1d679af | 68 | tty_lock(tty); |
1da177e4 LT |
69 | } |
70 | } | |
71 | ||
72 | /* | |
73 | * The unthrottle routine is called by the line discipline to signal | |
74 | * that it can receive more characters. For PTY's, the TTY_THROTTLED | |
75 | * flag is always set, to force the line discipline to always call the | |
fe9cd962 | 76 | * unthrottle routine when there are fewer than TTY_THRESHOLD_UNTHROTTLE |
1da177e4 LT |
77 | * characters in the queue. This is necessary since each time this |
78 | * happens, we need to wake up any sleeping processes that could be | |
79 | * (1) trying to send data to the pty, or (2) waiting in wait_until_sent() | |
80 | * for the pty buffer to be drained. | |
81 | */ | |
fe9cd962 | 82 | static void pty_unthrottle(struct tty_struct *tty) |
1da177e4 | 83 | { |
d945cb9c | 84 | tty_wakeup(tty->link); |
1da177e4 LT |
85 | set_bit(TTY_THROTTLED, &tty->flags); |
86 | } | |
87 | ||
d945cb9c AC |
88 | /** |
89 | * pty_space - report space left for writing | |
90 | * @to: tty we are writing into | |
1da177e4 | 91 | * |
d945cb9c AC |
92 | * The tty buffers allow 64K but we sneak a peak and clip at 8K this |
93 | * allows a lot of overspill room for echo and other fun messes to | |
94 | * be handled properly | |
95 | */ | |
96 | ||
97 | static int pty_space(struct tty_struct *to) | |
98 | { | |
99 | int n = 8192 - to->buf.memory_used; | |
100 | if (n < 0) | |
101 | return 0; | |
102 | return n; | |
103 | } | |
104 | ||
105 | /** | |
106 | * pty_write - write to a pty | |
107 | * @tty: the tty we write from | |
108 | * @buf: kernel buffer of data | |
109 | * @count: bytes to write | |
762faaed | 110 | * |
d945cb9c AC |
111 | * Our "hardware" write method. Data is coming from the ldisc which |
112 | * may be in a non sleeping state. We simply throw this at the other | |
113 | * end of the link as if we were an IRQ handler receiving stuff for | |
114 | * the other side of the pty/tty pair. | |
1da177e4 | 115 | */ |
d945cb9c | 116 | |
ac89a917 | 117 | static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c) |
1da177e4 LT |
118 | { |
119 | struct tty_struct *to = tty->link; | |
1da177e4 | 120 | |
d945cb9c | 121 | if (tty->stopped) |
1da177e4 | 122 | return 0; |
d945cb9c | 123 | |
d945cb9c AC |
124 | if (c > 0) { |
125 | /* Stuff the data into the input queue of the other end */ | |
126 | c = tty_insert_flip_string(to, buf, c); | |
127 | /* And shovel */ | |
202c4675 LT |
128 | if (c) { |
129 | tty_flip_buffer_push(to); | |
130 | tty_wakeup(tty); | |
131 | } | |
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 | { | |
85dfd81d LT |
146 | if (tty->stopped) |
147 | return 0; | |
d945cb9c | 148 | return pty_space(tty->link); |
1da177e4 LT |
149 | } |
150 | ||
d945cb9c AC |
151 | /** |
152 | * pty_chars_in_buffer - characters currently in our tx queue | |
153 | * @tty: our tty | |
fe9cd962 | 154 | * |
d945cb9c AC |
155 | * Report how much we have in the transmit queue. As everything is |
156 | * instantly at the other end this is easy to implement. | |
1da177e4 | 157 | */ |
d945cb9c | 158 | |
1da177e4 LT |
159 | static int pty_chars_in_buffer(struct tty_struct *tty) |
160 | { | |
d945cb9c | 161 | return 0; |
1da177e4 LT |
162 | } |
163 | ||
164 | /* Set the lock flag on a pty */ | |
fe9cd962 | 165 | static int pty_set_lock(struct tty_struct *tty, int __user *arg) |
1da177e4 LT |
166 | { |
167 | int val; | |
fe9cd962 | 168 | if (get_user(val, arg)) |
1da177e4 LT |
169 | return -EFAULT; |
170 | if (val) | |
171 | set_bit(TTY_PTY_LOCK, &tty->flags); | |
172 | else | |
173 | clear_bit(TTY_PTY_LOCK, &tty->flags); | |
174 | return 0; | |
175 | } | |
176 | ||
26df6d13 | 177 | /* Send a signal to the slave */ |
178 | static int pty_signal(struct tty_struct *tty, int sig) | |
179 | { | |
180 | unsigned long flags; | |
181 | struct pid *pgrp; | |
182 | ||
183 | if (tty->link) { | |
184 | spin_lock_irqsave(&tty->link->ctrl_lock, flags); | |
185 | pgrp = get_pid(tty->link->pgrp); | |
186 | spin_unlock_irqrestore(&tty->link->ctrl_lock, flags); | |
187 | ||
188 | kill_pgrp(pgrp, sig, 1); | |
189 | put_pid(pgrp); | |
190 | } | |
191 | return 0; | |
192 | } | |
193 | ||
1da177e4 LT |
194 | static void pty_flush_buffer(struct tty_struct *tty) |
195 | { | |
196 | struct tty_struct *to = tty->link; | |
04f378b1 | 197 | unsigned long flags; |
fe9cd962 | 198 | |
1da177e4 LT |
199 | if (!to) |
200 | return; | |
d945cb9c | 201 | /* tty_buffer_flush(to); FIXME */ |
1da177e4 | 202 | if (to->packet) { |
04f378b1 | 203 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
1da177e4 LT |
204 | tty->ctrl_status |= TIOCPKT_FLUSHWRITE; |
205 | wake_up_interruptible(&to->read_wait); | |
04f378b1 | 206 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
1da177e4 LT |
207 | } |
208 | } | |
209 | ||
fe9cd962 | 210 | static int pty_open(struct tty_struct *tty, struct file *filp) |
1da177e4 LT |
211 | { |
212 | int retval = -ENODEV; | |
213 | ||
214 | if (!tty || !tty->link) | |
215 | goto out; | |
216 | ||
217 | retval = -EIO; | |
218 | if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) | |
219 | goto out; | |
220 | if (test_bit(TTY_PTY_LOCK, &tty->link->flags)) | |
221 | goto out; | |
222 | if (tty->link->count != 1) | |
223 | goto out; | |
224 | ||
225 | clear_bit(TTY_OTHER_CLOSED, &tty->link->flags); | |
226 | set_bit(TTY_THROTTLED, &tty->flags); | |
1da177e4 LT |
227 | retval = 0; |
228 | out: | |
229 | return retval; | |
230 | } | |
231 | ||
fe9cd962 AC |
232 | static void pty_set_termios(struct tty_struct *tty, |
233 | struct ktermios *old_termios) | |
1da177e4 | 234 | { |
fe9cd962 AC |
235 | tty->termios->c_cflag &= ~(CSIZE | PARENB); |
236 | tty->termios->c_cflag |= (CS8 | CREAD); | |
1da177e4 LT |
237 | } |
238 | ||
fc6f6238 AC |
239 | /** |
240 | * pty_do_resize - resize event | |
241 | * @tty: tty being resized | |
c774bda2 | 242 | * @ws: window size being set. |
fc6f6238 | 243 | * |
3ad2f3fb | 244 | * Update the termios variables and send the necessary signals to |
fc6f6238 AC |
245 | * peform a terminal resize correctly |
246 | */ | |
247 | ||
248 | int pty_resize(struct tty_struct *tty, struct winsize *ws) | |
249 | { | |
250 | struct pid *pgrp, *rpgrp; | |
251 | unsigned long flags; | |
252 | struct tty_struct *pty = tty->link; | |
253 | ||
254 | /* For a PTY we need to lock the tty side */ | |
255 | mutex_lock(&tty->termios_mutex); | |
256 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) | |
257 | goto done; | |
258 | ||
259 | /* Get the PID values and reference them so we can | |
260 | avoid holding the tty ctrl lock while sending signals. | |
261 | We need to lock these individually however. */ | |
262 | ||
263 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
264 | pgrp = get_pid(tty->pgrp); | |
265 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
266 | ||
267 | spin_lock_irqsave(&pty->ctrl_lock, flags); | |
268 | rpgrp = get_pid(pty->pgrp); | |
269 | spin_unlock_irqrestore(&pty->ctrl_lock, flags); | |
270 | ||
271 | if (pgrp) | |
272 | kill_pgrp(pgrp, SIGWINCH, 1); | |
273 | if (rpgrp != pgrp && rpgrp) | |
274 | kill_pgrp(rpgrp, SIGWINCH, 1); | |
275 | ||
276 | put_pid(pgrp); | |
277 | put_pid(rpgrp); | |
278 | ||
279 | tty->winsize = *ws; | |
280 | pty->winsize = *ws; /* Never used so will go away soon */ | |
281 | done: | |
282 | mutex_unlock(&tty->termios_mutex); | |
283 | return 0; | |
284 | } | |
285 | ||
342a5971 LT |
286 | /* Traditional BSD devices */ |
287 | #ifdef CONFIG_LEGACY_PTYS | |
288 | ||
bf970ee4 AC |
289 | static int pty_install(struct tty_driver *driver, struct tty_struct *tty) |
290 | { | |
291 | struct tty_struct *o_tty; | |
292 | int idx = tty->index; | |
293 | int retval; | |
294 | ||
295 | o_tty = alloc_tty_struct(); | |
296 | if (!o_tty) | |
297 | return -ENOMEM; | |
298 | if (!try_module_get(driver->other->owner)) { | |
299 | /* This cannot in fact currently happen */ | |
8a1b8d70 JS |
300 | retval = -ENOMEM; |
301 | goto err_free_tty; | |
bf970ee4 AC |
302 | } |
303 | initialize_tty_struct(o_tty, driver->other, idx); | |
304 | ||
305 | /* We always use new tty termios data so we can do this | |
306 | the easy way .. */ | |
307 | retval = tty_init_termios(tty); | |
308 | if (retval) | |
a9dccddb | 309 | goto err_deinit_tty; |
bf970ee4 AC |
310 | |
311 | retval = tty_init_termios(o_tty); | |
8a1b8d70 JS |
312 | if (retval) |
313 | goto err_free_termios; | |
fe9cd962 | 314 | |
bf970ee4 AC |
315 | /* |
316 | * Everything allocated ... set up the o_tty structure. | |
317 | */ | |
318 | driver->other->ttys[idx] = o_tty; | |
319 | tty_driver_kref_get(driver->other); | |
320 | if (driver->subtype == PTY_TYPE_MASTER) | |
321 | o_tty->count++; | |
322 | /* Establish the links in both directions */ | |
323 | tty->link = o_tty; | |
324 | o_tty->link = tty; | |
325 | ||
326 | tty_driver_kref_get(driver); | |
327 | tty->count++; | |
328 | driver->ttys[idx] = tty; | |
329 | return 0; | |
8a1b8d70 JS |
330 | err_free_termios: |
331 | tty_free_termios(tty); | |
a9dccddb JS |
332 | err_deinit_tty: |
333 | deinitialize_tty_struct(o_tty); | |
bf970ee4 | 334 | module_put(o_tty->driver->owner); |
8a1b8d70 | 335 | err_free_tty: |
bf970ee4 | 336 | free_tty_struct(o_tty); |
8a1b8d70 | 337 | return retval; |
bf970ee4 AC |
338 | } |
339 | ||
6caa76b7 | 340 | static int pty_bsd_ioctl(struct tty_struct *tty, |
1da177e4 LT |
341 | unsigned int cmd, unsigned long arg) |
342 | { | |
343 | switch (cmd) { | |
344 | case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */ | |
345 | return pty_set_lock(tty, (int __user *) arg); | |
26df6d13 | 346 | case TIOCSIG: /* Send signal to other side of pty */ |
347 | return pty_signal(tty, (int) arg); | |
1da177e4 LT |
348 | } |
349 | return -ENOIOCTLCMD; | |
350 | } | |
351 | ||
dc8c8587 KS |
352 | static int legacy_count = CONFIG_LEGACY_PTY_COUNT; |
353 | module_param(legacy_count, int, 0); | |
354 | ||
342a5971 LT |
355 | /* |
356 | * The master side of a pty can do TIOCSPTLCK and thus | |
357 | * has pty_bsd_ioctl. | |
358 | */ | |
359 | static const struct tty_operations master_pty_ops_bsd = { | |
360 | .install = pty_install, | |
3e8e88ca AC |
361 | .open = pty_open, |
362 | .close = pty_close, | |
363 | .write = pty_write, | |
364 | .write_room = pty_write_room, | |
365 | .flush_buffer = pty_flush_buffer, | |
366 | .chars_in_buffer = pty_chars_in_buffer, | |
367 | .unthrottle = pty_unthrottle, | |
368 | .set_termios = pty_set_termios, | |
369 | .ioctl = pty_bsd_ioctl, | |
fc6f6238 | 370 | .resize = pty_resize |
3e8e88ca AC |
371 | }; |
372 | ||
342a5971 LT |
373 | static const struct tty_operations slave_pty_ops_bsd = { |
374 | .install = pty_install, | |
375 | .open = pty_open, | |
376 | .close = pty_close, | |
377 | .write = pty_write, | |
378 | .write_room = pty_write_room, | |
379 | .flush_buffer = pty_flush_buffer, | |
380 | .chars_in_buffer = pty_chars_in_buffer, | |
381 | .unthrottle = pty_unthrottle, | |
382 | .set_termios = pty_set_termios, | |
383 | .resize = pty_resize | |
384 | }; | |
385 | ||
1da177e4 LT |
386 | static void __init legacy_pty_init(void) |
387 | { | |
342a5971 LT |
388 | struct tty_driver *pty_driver, *pty_slave_driver; |
389 | ||
dc8c8587 KS |
390 | if (legacy_count <= 0) |
391 | return; | |
1da177e4 | 392 | |
dc8c8587 | 393 | pty_driver = alloc_tty_driver(legacy_count); |
1da177e4 LT |
394 | if (!pty_driver) |
395 | panic("Couldn't allocate pty driver"); | |
396 | ||
dc8c8587 | 397 | pty_slave_driver = alloc_tty_driver(legacy_count); |
1da177e4 LT |
398 | if (!pty_slave_driver) |
399 | panic("Couldn't allocate pty slave driver"); | |
400 | ||
1da177e4 LT |
401 | pty_driver->driver_name = "pty_master"; |
402 | pty_driver->name = "pty"; | |
1da177e4 LT |
403 | pty_driver->major = PTY_MASTER_MAJOR; |
404 | pty_driver->minor_start = 0; | |
405 | pty_driver->type = TTY_DRIVER_TYPE_PTY; | |
406 | pty_driver->subtype = PTY_TYPE_MASTER; | |
407 | pty_driver->init_termios = tty_std_termios; | |
408 | pty_driver->init_termios.c_iflag = 0; | |
409 | pty_driver->init_termios.c_oflag = 0; | |
410 | pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
411 | pty_driver->init_termios.c_lflag = 0; | |
606d099c AC |
412 | pty_driver->init_termios.c_ispeed = 38400; |
413 | pty_driver->init_termios.c_ospeed = 38400; | |
1da177e4 LT |
414 | pty_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW; |
415 | pty_driver->other = pty_slave_driver; | |
342a5971 | 416 | tty_set_operations(pty_driver, &master_pty_ops_bsd); |
1da177e4 | 417 | |
1da177e4 LT |
418 | pty_slave_driver->driver_name = "pty_slave"; |
419 | pty_slave_driver->name = "ttyp"; | |
1da177e4 LT |
420 | pty_slave_driver->major = PTY_SLAVE_MAJOR; |
421 | pty_slave_driver->minor_start = 0; | |
422 | pty_slave_driver->type = TTY_DRIVER_TYPE_PTY; | |
423 | pty_slave_driver->subtype = PTY_TYPE_SLAVE; | |
424 | pty_slave_driver->init_termios = tty_std_termios; | |
425 | pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
606d099c AC |
426 | pty_slave_driver->init_termios.c_ispeed = 38400; |
427 | pty_slave_driver->init_termios.c_ospeed = 38400; | |
1da177e4 LT |
428 | pty_slave_driver->flags = TTY_DRIVER_RESET_TERMIOS | |
429 | TTY_DRIVER_REAL_RAW; | |
430 | pty_slave_driver->other = pty_driver; | |
342a5971 | 431 | tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd); |
1da177e4 LT |
432 | |
433 | if (tty_register_driver(pty_driver)) | |
434 | panic("Couldn't register pty driver"); | |
435 | if (tty_register_driver(pty_slave_driver)) | |
436 | panic("Couldn't register pty slave driver"); | |
437 | } | |
438 | #else | |
439 | static inline void legacy_pty_init(void) { } | |
440 | #endif | |
441 | ||
442 | /* Unix98 devices */ | |
443 | #ifdef CONFIG_UNIX98_PTYS | |
1da177e4 | 444 | |
d81ed103 AC |
445 | static struct cdev ptmx_cdev; |
446 | ||
6caa76b7 | 447 | static int pty_unix98_ioctl(struct tty_struct *tty, |
1da177e4 LT |
448 | unsigned int cmd, unsigned long arg) |
449 | { | |
450 | switch (cmd) { | |
451 | case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */ | |
452 | return pty_set_lock(tty, (int __user *)arg); | |
453 | case TIOCGPTN: /* Get PT Number */ | |
454 | return put_user(tty->index, (unsigned int __user *)arg); | |
26df6d13 | 455 | case TIOCSIG: /* Send signal to other side of pty */ |
456 | return pty_signal(tty, (int) arg); | |
1da177e4 LT |
457 | } |
458 | ||
459 | return -ENOIOCTLCMD; | |
460 | } | |
461 | ||
99f1fe18 AC |
462 | /** |
463 | * ptm_unix98_lookup - find a pty master | |
464 | * @driver: ptm driver | |
465 | * @idx: tty index | |
466 | * | |
467 | * Look up a pty master device. Called under the tty_mutex for now. | |
468 | * This provides our locking. | |
469 | */ | |
470 | ||
15f1a633 SB |
471 | static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver, |
472 | struct inode *ptm_inode, int idx) | |
99f1fe18 | 473 | { |
593a27c4 KK |
474 | /* Master must be open via /dev/ptmx */ |
475 | return ERR_PTR(-EIO); | |
99f1fe18 AC |
476 | } |
477 | ||
478 | /** | |
479 | * pts_unix98_lookup - find a pty slave | |
480 | * @driver: pts driver | |
481 | * @idx: tty index | |
482 | * | |
483 | * Look up a pty master device. Called under the tty_mutex for now. | |
d739e65b | 484 | * This provides our locking for the tty pointer. |
99f1fe18 AC |
485 | */ |
486 | ||
15f1a633 SB |
487 | static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver, |
488 | struct inode *pts_inode, int idx) | |
99f1fe18 | 489 | { |
d739e65b AC |
490 | struct tty_struct *tty; |
491 | ||
492 | mutex_lock(&devpts_mutex); | |
493 | tty = devpts_get_tty(pts_inode, idx); | |
494 | mutex_unlock(&devpts_mutex); | |
99f1fe18 AC |
495 | /* Master must be open before slave */ |
496 | if (!tty) | |
497 | return ERR_PTR(-EIO); | |
498 | return tty; | |
499 | } | |
500 | ||
bf970ee4 | 501 | static void pty_unix98_shutdown(struct tty_struct *tty) |
feebed65 | 502 | { |
24d406a6 | 503 | tty_driver_remove_tty(tty->driver, tty); |
feebed65 AC |
504 | /* We have our own method as we don't use the tty index */ |
505 | kfree(tty->termios); | |
feebed65 AC |
506 | } |
507 | ||
8b0a88d5 AC |
508 | /* We have no need to install and remove our tty objects as devpts does all |
509 | the work for us */ | |
510 | ||
bf970ee4 | 511 | static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 | 512 | { |
bf970ee4 AC |
513 | struct tty_struct *o_tty; |
514 | int idx = tty->index; | |
515 | ||
516 | o_tty = alloc_tty_struct(); | |
517 | if (!o_tty) | |
518 | return -ENOMEM; | |
519 | if (!try_module_get(driver->other->owner)) { | |
520 | /* This cannot in fact currently happen */ | |
c18d77aa | 521 | goto err_free_tty; |
bf970ee4 AC |
522 | } |
523 | initialize_tty_struct(o_tty, driver->other, idx); | |
524 | ||
8dff04ea | 525 | tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL); |
bf970ee4 | 526 | if (tty->termios == NULL) |
c18d77aa | 527 | goto err_free_mem; |
bf970ee4 | 528 | *tty->termios = driver->init_termios; |
8dff04ea AC |
529 | tty->termios_locked = tty->termios + 1; |
530 | ||
531 | o_tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL); | |
bf970ee4 | 532 | if (o_tty->termios == NULL) |
c18d77aa | 533 | goto err_free_mem; |
bf970ee4 | 534 | *o_tty->termios = driver->other->init_termios; |
8dff04ea | 535 | o_tty->termios_locked = o_tty->termios + 1; |
bf970ee4 AC |
536 | |
537 | tty_driver_kref_get(driver->other); | |
538 | if (driver->subtype == PTY_TYPE_MASTER) | |
539 | o_tty->count++; | |
540 | /* Establish the links in both directions */ | |
541 | tty->link = o_tty; | |
542 | o_tty->link = tty; | |
543 | /* | |
544 | * All structures have been allocated, so now we install them. | |
545 | * Failures after this point use release_tty to clean up, so | |
546 | * there's no need to null out the local pointers. | |
547 | */ | |
548 | tty_driver_kref_get(driver); | |
549 | tty->count++; | |
8b0a88d5 | 550 | return 0; |
c18d77aa | 551 | err_free_mem: |
a9dccddb | 552 | deinitialize_tty_struct(o_tty); |
8dff04ea | 553 | kfree(o_tty->termios); |
c18d77aa | 554 | kfree(tty->termios); |
bf970ee4 | 555 | module_put(o_tty->driver->owner); |
c18d77aa | 556 | err_free_tty: |
bf970ee4 | 557 | free_tty_struct(o_tty); |
bf970ee4 | 558 | return -ENOMEM; |
8b0a88d5 AC |
559 | } |
560 | ||
484af54d JS |
561 | static void ptm_unix98_remove(struct tty_driver *driver, struct tty_struct *tty) |
562 | { | |
484af54d JS |
563 | } |
564 | ||
565 | static void pts_unix98_remove(struct tty_driver *driver, struct tty_struct *tty) | |
8b0a88d5 AC |
566 | { |
567 | } | |
568 | ||
feebed65 | 569 | static const struct tty_operations ptm_unix98_ops = { |
99f1fe18 | 570 | .lookup = ptm_unix98_lookup, |
bf970ee4 | 571 | .install = pty_unix98_install, |
484af54d | 572 | .remove = ptm_unix98_remove, |
3e8e88ca AC |
573 | .open = pty_open, |
574 | .close = pty_close, | |
575 | .write = pty_write, | |
576 | .write_room = pty_write_room, | |
577 | .flush_buffer = pty_flush_buffer, | |
578 | .chars_in_buffer = pty_chars_in_buffer, | |
579 | .unthrottle = pty_unthrottle, | |
580 | .set_termios = pty_set_termios, | |
feebed65 | 581 | .ioctl = pty_unix98_ioctl, |
fc6f6238 AC |
582 | .shutdown = pty_unix98_shutdown, |
583 | .resize = pty_resize | |
3e8e88ca AC |
584 | }; |
585 | ||
99f1fe18 AC |
586 | static const struct tty_operations pty_unix98_ops = { |
587 | .lookup = pts_unix98_lookup, | |
bf970ee4 | 588 | .install = pty_unix98_install, |
484af54d | 589 | .remove = pts_unix98_remove, |
99f1fe18 AC |
590 | .open = pty_open, |
591 | .close = pty_close, | |
592 | .write = pty_write, | |
593 | .write_room = pty_write_room, | |
594 | .flush_buffer = pty_flush_buffer, | |
595 | .chars_in_buffer = pty_chars_in_buffer, | |
596 | .unthrottle = pty_unthrottle, | |
597 | .set_termios = pty_set_termios, | |
bf970ee4 | 598 | .shutdown = pty_unix98_shutdown |
99f1fe18 | 599 | }; |
d81ed103 AC |
600 | |
601 | /** | |
602 | * ptmx_open - open a unix 98 pty master | |
603 | * @inode: inode of device file | |
604 | * @filp: file pointer to tty | |
605 | * | |
606 | * Allocate a unix98 pty master device from the ptmx driver. | |
607 | * | |
608 | * Locking: tty_mutex protects the init_dev work. tty->count should | |
609 | * protect the rest. | |
610 | * allocated_ptys_lock handles the list of free pty numbers | |
611 | */ | |
612 | ||
64ba3dc3 | 613 | static int ptmx_open(struct inode *inode, struct file *filp) |
d81ed103 AC |
614 | { |
615 | struct tty_struct *tty; | |
616 | int retval; | |
617 | int index; | |
618 | ||
619 | nonseekable_open(inode, filp); | |
620 | ||
fa90e1c9 JS |
621 | retval = tty_alloc_file(filp); |
622 | if (retval) | |
623 | return retval; | |
624 | ||
d81ed103 | 625 | /* find a device that is not in use. */ |
d29f3ef3 | 626 | mutex_lock(&devpts_mutex); |
15f1a633 | 627 | index = devpts_new_index(inode); |
fa90e1c9 JS |
628 | if (index < 0) { |
629 | retval = index; | |
630 | goto err_file; | |
631 | } | |
d81ed103 | 632 | |
d29f3ef3 AC |
633 | mutex_unlock(&devpts_mutex); |
634 | ||
d81ed103 | 635 | mutex_lock(&tty_mutex); |
d739e65b | 636 | mutex_lock(&devpts_mutex); |
593a27c4 | 637 | tty = tty_init_dev(ptm_driver, index); |
d81ed103 | 638 | |
73ec06fc AC |
639 | if (IS_ERR(tty)) { |
640 | retval = PTR_ERR(tty); | |
d81ed103 | 641 | goto out; |
73ec06fc | 642 | } |
d81ed103 | 643 | |
d29f3ef3 AC |
644 | /* The tty returned here is locked so we can safely |
645 | drop the mutex */ | |
646 | mutex_unlock(&devpts_mutex); | |
647 | mutex_unlock(&tty_mutex); | |
648 | ||
d81ed103 | 649 | set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ |
ee2ffa0d | 650 | |
fa90e1c9 | 651 | tty_add_file(tty, filp); |
d81ed103 | 652 | |
15f1a633 | 653 | retval = devpts_pty_new(inode, tty->link); |
d81ed103 | 654 | if (retval) |
1177c0ef | 655 | goto err_release; |
d81ed103 AC |
656 | |
657 | retval = ptm_driver->ops->open(tty, filp); | |
64ba3dc3 | 658 | if (retval) |
1177c0ef JS |
659 | goto err_release; |
660 | ||
d29f3ef3 | 661 | tty_unlock(tty); |
1177c0ef JS |
662 | return 0; |
663 | err_release: | |
d29f3ef3 | 664 | tty_unlock(tty); |
eeb89d91 | 665 | tty_release(inode, filp); |
d81ed103 AC |
666 | return retval; |
667 | out: | |
d29f3ef3 | 668 | mutex_unlock(&tty_mutex); |
d3bda529 | 669 | devpts_kill_index(inode, index); |
fa90e1c9 | 670 | err_file: |
d29f3ef3 | 671 | mutex_unlock(&devpts_mutex); |
fa90e1c9 | 672 | tty_free_file(filp); |
64ba3dc3 | 673 | return retval; |
d81ed103 AC |
674 | } |
675 | ||
676 | static struct file_operations ptmx_fops; | |
677 | ||
1da177e4 LT |
678 | static void __init unix98_pty_init(void) |
679 | { | |
1da177e4 LT |
680 | ptm_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX); |
681 | if (!ptm_driver) | |
682 | panic("Couldn't allocate Unix98 ptm driver"); | |
683 | pts_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX); | |
684 | if (!pts_driver) | |
685 | panic("Couldn't allocate Unix98 pts driver"); | |
686 | ||
1da177e4 LT |
687 | ptm_driver->driver_name = "pty_master"; |
688 | ptm_driver->name = "ptm"; | |
689 | ptm_driver->major = UNIX98_PTY_MASTER_MAJOR; | |
690 | ptm_driver->minor_start = 0; | |
691 | ptm_driver->type = TTY_DRIVER_TYPE_PTY; | |
692 | ptm_driver->subtype = PTY_TYPE_MASTER; | |
693 | ptm_driver->init_termios = tty_std_termios; | |
694 | ptm_driver->init_termios.c_iflag = 0; | |
695 | ptm_driver->init_termios.c_oflag = 0; | |
696 | ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
697 | ptm_driver->init_termios.c_lflag = 0; | |
606d099c AC |
698 | ptm_driver->init_termios.c_ispeed = 38400; |
699 | ptm_driver->init_termios.c_ospeed = 38400; | |
1da177e4 | 700 | ptm_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | |
331b8319 | 701 | TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM; |
1da177e4 | 702 | ptm_driver->other = pts_driver; |
feebed65 | 703 | tty_set_operations(ptm_driver, &ptm_unix98_ops); |
1da177e4 | 704 | |
1da177e4 LT |
705 | pts_driver->driver_name = "pty_slave"; |
706 | pts_driver->name = "pts"; | |
707 | pts_driver->major = UNIX98_PTY_SLAVE_MAJOR; | |
708 | pts_driver->minor_start = 0; | |
709 | pts_driver->type = TTY_DRIVER_TYPE_PTY; | |
710 | pts_driver->subtype = PTY_TYPE_SLAVE; | |
711 | pts_driver->init_termios = tty_std_termios; | |
712 | pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
606d099c AC |
713 | pts_driver->init_termios.c_ispeed = 38400; |
714 | pts_driver->init_termios.c_ospeed = 38400; | |
1da177e4 | 715 | pts_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | |
331b8319 | 716 | TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM; |
1da177e4 | 717 | pts_driver->other = ptm_driver; |
99f1fe18 | 718 | tty_set_operations(pts_driver, &pty_unix98_ops); |
fe9cd962 | 719 | |
1da177e4 LT |
720 | if (tty_register_driver(ptm_driver)) |
721 | panic("Couldn't register Unix98 ptm driver"); | |
722 | if (tty_register_driver(pts_driver)) | |
723 | panic("Couldn't register Unix98 pts driver"); | |
724 | ||
d81ed103 AC |
725 | /* Now create the /dev/ptmx special device */ |
726 | tty_default_fops(&ptmx_fops); | |
727 | ptmx_fops.open = ptmx_open; | |
728 | ||
729 | cdev_init(&ptmx_cdev, &ptmx_fops); | |
730 | if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) || | |
731 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0) | |
732 | panic("Couldn't register /dev/ptmx driver\n"); | |
733 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx"); | |
1da177e4 | 734 | } |
d81ed103 | 735 | |
1da177e4 LT |
736 | #else |
737 | static inline void unix98_pty_init(void) { } | |
738 | #endif | |
739 | ||
740 | static int __init pty_init(void) | |
741 | { | |
742 | legacy_pty_init(); | |
743 | unix98_pty_init(); | |
744 | return 0; | |
745 | } | |
746 | module_init(pty_init); |