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; | |
89c8d91e | 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 |
89c8d91e | 66 | tty_unlock(tty); |
11dbf203 | 67 | tty_vhangup(tty->link); |
89c8d91e | 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 | { |
adc8d746 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 | ||
d155255a AC |
286 | /** |
287 | * pty_common_install - set up the pty pair | |
288 | * @driver: the pty driver | |
289 | * @tty: the tty being instantiated | |
290 | * @bool: legacy, true if this is BSD style | |
291 | * | |
292 | * Perform the initial set up for the tty/pty pair. Called from the | |
293 | * tty layer when the port is first opened. | |
294 | * | |
295 | * Locking: the caller must hold the tty_mutex | |
296 | */ | |
5d249bc6 JS |
297 | static int pty_common_install(struct tty_driver *driver, struct tty_struct *tty, |
298 | bool legacy) | |
bf970ee4 AC |
299 | { |
300 | struct tty_struct *o_tty; | |
d03702a2 | 301 | struct tty_port *ports[2]; |
bf970ee4 | 302 | int idx = tty->index; |
5d249bc6 | 303 | int retval = -ENOMEM; |
bf970ee4 AC |
304 | |
305 | o_tty = alloc_tty_struct(); | |
6f9ea7ad JS |
306 | if (!o_tty) |
307 | goto err; | |
d03702a2 JS |
308 | ports[0] = kmalloc(sizeof **ports, GFP_KERNEL); |
309 | ports[1] = kmalloc(sizeof **ports, GFP_KERNEL); | |
6f9ea7ad | 310 | if (!ports[0] || !ports[1]) |
d03702a2 | 311 | goto err_free_tty; |
bf970ee4 AC |
312 | if (!try_module_get(driver->other->owner)) { |
313 | /* This cannot in fact currently happen */ | |
8a1b8d70 | 314 | goto err_free_tty; |
bf970ee4 AC |
315 | } |
316 | initialize_tty_struct(o_tty, driver->other, idx); | |
317 | ||
5d249bc6 JS |
318 | if (legacy) { |
319 | /* We always use new tty termios data so we can do this | |
320 | the easy way .. */ | |
321 | retval = tty_init_termios(tty); | |
322 | if (retval) | |
323 | goto err_deinit_tty; | |
324 | ||
325 | retval = tty_init_termios(o_tty); | |
326 | if (retval) | |
327 | goto err_free_termios; | |
328 | ||
329 | driver->other->ttys[idx] = o_tty; | |
330 | driver->ttys[idx] = tty; | |
331 | } else { | |
adc8d746 AC |
332 | memset(&tty->termios_locked, 0, sizeof(tty->termios_locked)); |
333 | tty->termios = driver->init_termios; | |
334 | memset(&o_tty->termios_locked, 0, sizeof(tty->termios_locked)); | |
335 | o_tty->termios = driver->other->init_termios; | |
5d249bc6 | 336 | } |
fe9cd962 | 337 | |
bf970ee4 AC |
338 | /* |
339 | * Everything allocated ... set up the o_tty structure. | |
340 | */ | |
bf970ee4 AC |
341 | tty_driver_kref_get(driver->other); |
342 | if (driver->subtype == PTY_TYPE_MASTER) | |
343 | o_tty->count++; | |
344 | /* Establish the links in both directions */ | |
345 | tty->link = o_tty; | |
346 | o_tty->link = tty; | |
d03702a2 JS |
347 | tty_port_init(ports[0]); |
348 | tty_port_init(ports[1]); | |
349 | o_tty->port = ports[0]; | |
350 | tty->port = ports[1]; | |
bf970ee4 AC |
351 | |
352 | tty_driver_kref_get(driver); | |
353 | tty->count++; | |
bf970ee4 | 354 | return 0; |
8a1b8d70 | 355 | err_free_termios: |
5d249bc6 JS |
356 | if (legacy) |
357 | tty_free_termios(tty); | |
a9dccddb JS |
358 | err_deinit_tty: |
359 | deinitialize_tty_struct(o_tty); | |
bf970ee4 | 360 | module_put(o_tty->driver->owner); |
8a1b8d70 | 361 | err_free_tty: |
d03702a2 JS |
362 | kfree(ports[0]); |
363 | kfree(ports[1]); | |
bf970ee4 | 364 | free_tty_struct(o_tty); |
6f9ea7ad | 365 | err: |
8a1b8d70 | 366 | return retval; |
bf970ee4 AC |
367 | } |
368 | ||
d03702a2 JS |
369 | static void pty_cleanup(struct tty_struct *tty) |
370 | { | |
371 | kfree(tty->port); | |
372 | } | |
373 | ||
5d249bc6 JS |
374 | /* Traditional BSD devices */ |
375 | #ifdef CONFIG_LEGACY_PTYS | |
376 | ||
377 | static int pty_install(struct tty_driver *driver, struct tty_struct *tty) | |
378 | { | |
379 | return pty_common_install(driver, tty, true); | |
380 | } | |
381 | ||
d155255a AC |
382 | static void pty_remove(struct tty_driver *driver, struct tty_struct *tty) |
383 | { | |
384 | struct tty_struct *pair = tty->link; | |
385 | driver->ttys[tty->index] = NULL; | |
386 | if (pair) | |
387 | pair->driver->ttys[pair->index] = NULL; | |
388 | } | |
389 | ||
6caa76b7 | 390 | static int pty_bsd_ioctl(struct tty_struct *tty, |
1da177e4 LT |
391 | unsigned int cmd, unsigned long arg) |
392 | { | |
393 | switch (cmd) { | |
394 | case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */ | |
395 | return pty_set_lock(tty, (int __user *) arg); | |
26df6d13 | 396 | case TIOCSIG: /* Send signal to other side of pty */ |
397 | return pty_signal(tty, (int) arg); | |
1da177e4 LT |
398 | } |
399 | return -ENOIOCTLCMD; | |
400 | } | |
401 | ||
dc8c8587 KS |
402 | static int legacy_count = CONFIG_LEGACY_PTY_COUNT; |
403 | module_param(legacy_count, int, 0); | |
404 | ||
342a5971 LT |
405 | /* |
406 | * The master side of a pty can do TIOCSPTLCK and thus | |
407 | * has pty_bsd_ioctl. | |
408 | */ | |
409 | static const struct tty_operations master_pty_ops_bsd = { | |
410 | .install = pty_install, | |
3e8e88ca AC |
411 | .open = pty_open, |
412 | .close = pty_close, | |
413 | .write = pty_write, | |
414 | .write_room = pty_write_room, | |
415 | .flush_buffer = pty_flush_buffer, | |
416 | .chars_in_buffer = pty_chars_in_buffer, | |
417 | .unthrottle = pty_unthrottle, | |
418 | .set_termios = pty_set_termios, | |
419 | .ioctl = pty_bsd_ioctl, | |
d03702a2 | 420 | .cleanup = pty_cleanup, |
d155255a AC |
421 | .resize = pty_resize, |
422 | .remove = pty_remove | |
3e8e88ca AC |
423 | }; |
424 | ||
342a5971 LT |
425 | static const struct tty_operations slave_pty_ops_bsd = { |
426 | .install = pty_install, | |
427 | .open = pty_open, | |
428 | .close = pty_close, | |
429 | .write = pty_write, | |
430 | .write_room = pty_write_room, | |
431 | .flush_buffer = pty_flush_buffer, | |
432 | .chars_in_buffer = pty_chars_in_buffer, | |
433 | .unthrottle = pty_unthrottle, | |
434 | .set_termios = pty_set_termios, | |
d03702a2 | 435 | .cleanup = pty_cleanup, |
d155255a AC |
436 | .resize = pty_resize, |
437 | .remove = pty_remove | |
342a5971 LT |
438 | }; |
439 | ||
1da177e4 LT |
440 | static void __init legacy_pty_init(void) |
441 | { | |
342a5971 LT |
442 | struct tty_driver *pty_driver, *pty_slave_driver; |
443 | ||
dc8c8587 KS |
444 | if (legacy_count <= 0) |
445 | return; | |
1da177e4 | 446 | |
21aca2fa JS |
447 | pty_driver = tty_alloc_driver(legacy_count, |
448 | TTY_DRIVER_RESET_TERMIOS | | |
449 | TTY_DRIVER_REAL_RAW | | |
450 | TTY_DRIVER_DYNAMIC_ALLOC); | |
c3a6344a | 451 | if (IS_ERR(pty_driver)) |
1da177e4 LT |
452 | panic("Couldn't allocate pty driver"); |
453 | ||
21aca2fa JS |
454 | pty_slave_driver = tty_alloc_driver(legacy_count, |
455 | TTY_DRIVER_RESET_TERMIOS | | |
456 | TTY_DRIVER_REAL_RAW | | |
457 | TTY_DRIVER_DYNAMIC_ALLOC); | |
c3a6344a | 458 | if (IS_ERR(pty_slave_driver)) |
1da177e4 LT |
459 | panic("Couldn't allocate pty slave driver"); |
460 | ||
1da177e4 LT |
461 | pty_driver->driver_name = "pty_master"; |
462 | pty_driver->name = "pty"; | |
1da177e4 LT |
463 | pty_driver->major = PTY_MASTER_MAJOR; |
464 | pty_driver->minor_start = 0; | |
465 | pty_driver->type = TTY_DRIVER_TYPE_PTY; | |
466 | pty_driver->subtype = PTY_TYPE_MASTER; | |
467 | pty_driver->init_termios = tty_std_termios; | |
468 | pty_driver->init_termios.c_iflag = 0; | |
469 | pty_driver->init_termios.c_oflag = 0; | |
470 | pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
471 | pty_driver->init_termios.c_lflag = 0; | |
606d099c AC |
472 | pty_driver->init_termios.c_ispeed = 38400; |
473 | pty_driver->init_termios.c_ospeed = 38400; | |
1da177e4 | 474 | pty_driver->other = pty_slave_driver; |
342a5971 | 475 | tty_set_operations(pty_driver, &master_pty_ops_bsd); |
1da177e4 | 476 | |
1da177e4 LT |
477 | pty_slave_driver->driver_name = "pty_slave"; |
478 | pty_slave_driver->name = "ttyp"; | |
1da177e4 LT |
479 | pty_slave_driver->major = PTY_SLAVE_MAJOR; |
480 | pty_slave_driver->minor_start = 0; | |
481 | pty_slave_driver->type = TTY_DRIVER_TYPE_PTY; | |
482 | pty_slave_driver->subtype = PTY_TYPE_SLAVE; | |
483 | pty_slave_driver->init_termios = tty_std_termios; | |
484 | pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
606d099c AC |
485 | pty_slave_driver->init_termios.c_ispeed = 38400; |
486 | pty_slave_driver->init_termios.c_ospeed = 38400; | |
1da177e4 | 487 | pty_slave_driver->other = pty_driver; |
342a5971 | 488 | tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd); |
1da177e4 LT |
489 | |
490 | if (tty_register_driver(pty_driver)) | |
491 | panic("Couldn't register pty driver"); | |
492 | if (tty_register_driver(pty_slave_driver)) | |
493 | panic("Couldn't register pty slave driver"); | |
494 | } | |
495 | #else | |
496 | static inline void legacy_pty_init(void) { } | |
497 | #endif | |
498 | ||
499 | /* Unix98 devices */ | |
500 | #ifdef CONFIG_UNIX98_PTYS | |
1da177e4 | 501 | |
d81ed103 AC |
502 | static struct cdev ptmx_cdev; |
503 | ||
6caa76b7 | 504 | static int pty_unix98_ioctl(struct tty_struct *tty, |
1da177e4 LT |
505 | unsigned int cmd, unsigned long arg) |
506 | { | |
507 | switch (cmd) { | |
508 | case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */ | |
509 | return pty_set_lock(tty, (int __user *)arg); | |
510 | case TIOCGPTN: /* Get PT Number */ | |
511 | return put_user(tty->index, (unsigned int __user *)arg); | |
26df6d13 | 512 | case TIOCSIG: /* Send signal to other side of pty */ |
513 | return pty_signal(tty, (int) arg); | |
1da177e4 LT |
514 | } |
515 | ||
516 | return -ENOIOCTLCMD; | |
517 | } | |
518 | ||
99f1fe18 AC |
519 | /** |
520 | * ptm_unix98_lookup - find a pty master | |
521 | * @driver: ptm driver | |
522 | * @idx: tty index | |
523 | * | |
524 | * Look up a pty master device. Called under the tty_mutex for now. | |
525 | * This provides our locking. | |
526 | */ | |
527 | ||
15f1a633 SB |
528 | static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver, |
529 | struct inode *ptm_inode, int idx) | |
99f1fe18 | 530 | { |
593a27c4 KK |
531 | /* Master must be open via /dev/ptmx */ |
532 | return ERR_PTR(-EIO); | |
99f1fe18 AC |
533 | } |
534 | ||
535 | /** | |
536 | * pts_unix98_lookup - find a pty slave | |
537 | * @driver: pts driver | |
538 | * @idx: tty index | |
539 | * | |
540 | * Look up a pty master device. Called under the tty_mutex for now. | |
d739e65b | 541 | * This provides our locking for the tty pointer. |
99f1fe18 AC |
542 | */ |
543 | ||
15f1a633 SB |
544 | static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver, |
545 | struct inode *pts_inode, int idx) | |
99f1fe18 | 546 | { |
d739e65b AC |
547 | struct tty_struct *tty; |
548 | ||
549 | mutex_lock(&devpts_mutex); | |
8fcbaa2b | 550 | tty = devpts_get_priv(pts_inode); |
d739e65b | 551 | mutex_unlock(&devpts_mutex); |
99f1fe18 AC |
552 | /* Master must be open before slave */ |
553 | if (!tty) | |
554 | return ERR_PTR(-EIO); | |
555 | return tty; | |
556 | } | |
557 | ||
8b0a88d5 AC |
558 | /* We have no need to install and remove our tty objects as devpts does all |
559 | the work for us */ | |
560 | ||
bf970ee4 | 561 | static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 | 562 | { |
5d249bc6 | 563 | return pty_common_install(driver, tty, false); |
8b0a88d5 AC |
564 | } |
565 | ||
7171604a | 566 | static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 AC |
567 | { |
568 | } | |
569 | ||
feebed65 | 570 | static const struct tty_operations ptm_unix98_ops = { |
99f1fe18 | 571 | .lookup = ptm_unix98_lookup, |
bf970ee4 | 572 | .install = pty_unix98_install, |
7171604a | 573 | .remove = pty_unix98_remove, |
3e8e88ca AC |
574 | .open = pty_open, |
575 | .close = pty_close, | |
576 | .write = pty_write, | |
577 | .write_room = pty_write_room, | |
578 | .flush_buffer = pty_flush_buffer, | |
579 | .chars_in_buffer = pty_chars_in_buffer, | |
580 | .unthrottle = pty_unthrottle, | |
581 | .set_termios = pty_set_termios, | |
feebed65 | 582 | .ioctl = pty_unix98_ioctl, |
36b3c070 AC |
583 | .resize = pty_resize, |
584 | .cleanup = pty_cleanup | |
3e8e88ca AC |
585 | }; |
586 | ||
99f1fe18 AC |
587 | static const struct tty_operations pty_unix98_ops = { |
588 | .lookup = pts_unix98_lookup, | |
bf970ee4 | 589 | .install = pty_unix98_install, |
7171604a | 590 | .remove = pty_unix98_remove, |
99f1fe18 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, | |
d03702a2 | 599 | .cleanup = pty_cleanup, |
99f1fe18 | 600 | }; |
d81ed103 AC |
601 | |
602 | /** | |
603 | * ptmx_open - open a unix 98 pty master | |
604 | * @inode: inode of device file | |
605 | * @filp: file pointer to tty | |
606 | * | |
607 | * Allocate a unix98 pty master device from the ptmx driver. | |
608 | * | |
609 | * Locking: tty_mutex protects the init_dev work. tty->count should | |
610 | * protect the rest. | |
611 | * allocated_ptys_lock handles the list of free pty numbers | |
612 | */ | |
613 | ||
64ba3dc3 | 614 | static int ptmx_open(struct inode *inode, struct file *filp) |
d81ed103 AC |
615 | { |
616 | struct tty_struct *tty; | |
162b97cf | 617 | struct inode *slave_inode; |
d81ed103 AC |
618 | int retval; |
619 | int index; | |
620 | ||
621 | nonseekable_open(inode, filp); | |
622 | ||
fa90e1c9 JS |
623 | retval = tty_alloc_file(filp); |
624 | if (retval) | |
625 | return retval; | |
626 | ||
d81ed103 | 627 | /* find a device that is not in use. */ |
89c8d91e | 628 | mutex_lock(&devpts_mutex); |
15f1a633 | 629 | index = devpts_new_index(inode); |
fa90e1c9 JS |
630 | if (index < 0) { |
631 | retval = index; | |
05fb79e4 | 632 | mutex_unlock(&devpts_mutex); |
fa90e1c9 JS |
633 | goto err_file; |
634 | } | |
d81ed103 | 635 | |
89c8d91e AC |
636 | mutex_unlock(&devpts_mutex); |
637 | ||
d81ed103 | 638 | mutex_lock(&tty_mutex); |
593a27c4 | 639 | tty = tty_init_dev(ptm_driver, index); |
d81ed103 | 640 | |
73ec06fc AC |
641 | if (IS_ERR(tty)) { |
642 | retval = PTR_ERR(tty); | |
d81ed103 | 643 | goto out; |
73ec06fc | 644 | } |
d81ed103 | 645 | |
89c8d91e AC |
646 | /* The tty returned here is locked so we can safely |
647 | drop the mutex */ | |
648 | mutex_unlock(&tty_mutex); | |
649 | ||
d81ed103 | 650 | set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ |
ee2ffa0d | 651 | |
fa90e1c9 | 652 | tty_add_file(tty, filp); |
d81ed103 | 653 | |
162b97cf JS |
654 | slave_inode = devpts_pty_new(inode, tty->link); |
655 | if (IS_ERR(slave_inode)) { | |
656 | retval = PTR_ERR(slave_inode); | |
1177c0ef | 657 | goto err_release; |
162b97cf | 658 | } |
d81ed103 AC |
659 | |
660 | retval = ptm_driver->ops->open(tty, filp); | |
64ba3dc3 | 661 | if (retval) |
1177c0ef JS |
662 | goto err_release; |
663 | ||
89c8d91e | 664 | tty_unlock(tty); |
1177c0ef JS |
665 | return 0; |
666 | err_release: | |
89c8d91e | 667 | tty_unlock(tty); |
eeb89d91 | 668 | tty_release(inode, filp); |
d81ed103 AC |
669 | return retval; |
670 | out: | |
89c8d91e | 671 | mutex_unlock(&tty_mutex); |
d3bda529 | 672 | devpts_kill_index(inode, index); |
fa90e1c9 JS |
673 | err_file: |
674 | tty_free_file(filp); | |
64ba3dc3 | 675 | return retval; |
d81ed103 AC |
676 | } |
677 | ||
678 | static struct file_operations ptmx_fops; | |
679 | ||
1da177e4 LT |
680 | static void __init unix98_pty_init(void) |
681 | { | |
21aca2fa JS |
682 | ptm_driver = tty_alloc_driver(NR_UNIX98_PTY_MAX, |
683 | TTY_DRIVER_RESET_TERMIOS | | |
684 | TTY_DRIVER_REAL_RAW | | |
685 | TTY_DRIVER_DYNAMIC_DEV | | |
686 | TTY_DRIVER_DEVPTS_MEM | | |
687 | TTY_DRIVER_DYNAMIC_ALLOC); | |
c3a6344a | 688 | if (IS_ERR(ptm_driver)) |
1da177e4 | 689 | panic("Couldn't allocate Unix98 ptm driver"); |
21aca2fa JS |
690 | pts_driver = tty_alloc_driver(NR_UNIX98_PTY_MAX, |
691 | TTY_DRIVER_RESET_TERMIOS | | |
692 | TTY_DRIVER_REAL_RAW | | |
693 | TTY_DRIVER_DYNAMIC_DEV | | |
694 | TTY_DRIVER_DEVPTS_MEM | | |
695 | TTY_DRIVER_DYNAMIC_ALLOC); | |
c3a6344a | 696 | if (IS_ERR(pts_driver)) |
1da177e4 LT |
697 | panic("Couldn't allocate Unix98 pts driver"); |
698 | ||
1da177e4 LT |
699 | ptm_driver->driver_name = "pty_master"; |
700 | ptm_driver->name = "ptm"; | |
701 | ptm_driver->major = UNIX98_PTY_MASTER_MAJOR; | |
702 | ptm_driver->minor_start = 0; | |
703 | ptm_driver->type = TTY_DRIVER_TYPE_PTY; | |
704 | ptm_driver->subtype = PTY_TYPE_MASTER; | |
705 | ptm_driver->init_termios = tty_std_termios; | |
706 | ptm_driver->init_termios.c_iflag = 0; | |
707 | ptm_driver->init_termios.c_oflag = 0; | |
708 | ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
709 | ptm_driver->init_termios.c_lflag = 0; | |
606d099c AC |
710 | ptm_driver->init_termios.c_ispeed = 38400; |
711 | ptm_driver->init_termios.c_ospeed = 38400; | |
1da177e4 | 712 | ptm_driver->other = pts_driver; |
feebed65 | 713 | tty_set_operations(ptm_driver, &ptm_unix98_ops); |
1da177e4 | 714 | |
1da177e4 LT |
715 | pts_driver->driver_name = "pty_slave"; |
716 | pts_driver->name = "pts"; | |
717 | pts_driver->major = UNIX98_PTY_SLAVE_MAJOR; | |
718 | pts_driver->minor_start = 0; | |
719 | pts_driver->type = TTY_DRIVER_TYPE_PTY; | |
720 | pts_driver->subtype = PTY_TYPE_SLAVE; | |
721 | pts_driver->init_termios = tty_std_termios; | |
722 | pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
606d099c AC |
723 | pts_driver->init_termios.c_ispeed = 38400; |
724 | pts_driver->init_termios.c_ospeed = 38400; | |
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 | ||
d81ed103 AC |
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); |