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; | |
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); | |
ce1000dd | 58 | #ifdef CONFIG_UNIX98_PTYS |
d739e65b AC |
59 | if (tty->driver == ptm_driver) { |
60 | mutex_lock(&devpts_mutex); | |
ce1000dd | 61 | devpts_pty_kill(tty->link); |
d739e65b AC |
62 | mutex_unlock(&devpts_mutex); |
63 | } | |
ce1000dd | 64 | #endif |
6d31a88c | 65 | tty_unlock(); |
11dbf203 | 66 | tty_vhangup(tty->link); |
6d31a88c | 67 | tty_lock(); |
1da177e4 LT |
68 | } |
69 | } | |
70 | ||
71 | /* | |
72 | * The unthrottle routine is called by the line discipline to signal | |
73 | * that it can receive more characters. For PTY's, the TTY_THROTTLED | |
74 | * flag is always set, to force the line discipline to always call the | |
fe9cd962 | 75 | * unthrottle routine when there are fewer than TTY_THRESHOLD_UNTHROTTLE |
1da177e4 LT |
76 | * characters in the queue. This is necessary since each time this |
77 | * happens, we need to wake up any sleeping processes that could be | |
78 | * (1) trying to send data to the pty, or (2) waiting in wait_until_sent() | |
79 | * for the pty buffer to be drained. | |
80 | */ | |
fe9cd962 | 81 | static void pty_unthrottle(struct tty_struct *tty) |
1da177e4 | 82 | { |
d945cb9c | 83 | tty_wakeup(tty->link); |
1da177e4 LT |
84 | set_bit(TTY_THROTTLED, &tty->flags); |
85 | } | |
86 | ||
d945cb9c AC |
87 | /** |
88 | * pty_space - report space left for writing | |
89 | * @to: tty we are writing into | |
1da177e4 | 90 | * |
d945cb9c AC |
91 | * The tty buffers allow 64K but we sneak a peak and clip at 8K this |
92 | * allows a lot of overspill room for echo and other fun messes to | |
93 | * be handled properly | |
94 | */ | |
95 | ||
96 | static int pty_space(struct tty_struct *to) | |
97 | { | |
98 | int n = 8192 - to->buf.memory_used; | |
99 | if (n < 0) | |
100 | return 0; | |
101 | return n; | |
102 | } | |
103 | ||
104 | /** | |
105 | * pty_write - write to a pty | |
106 | * @tty: the tty we write from | |
107 | * @buf: kernel buffer of data | |
108 | * @count: bytes to write | |
762faaed | 109 | * |
d945cb9c AC |
110 | * Our "hardware" write method. Data is coming from the ldisc which |
111 | * may be in a non sleeping state. We simply throw this at the other | |
112 | * end of the link as if we were an IRQ handler receiving stuff for | |
113 | * the other side of the pty/tty pair. | |
1da177e4 | 114 | */ |
d945cb9c | 115 | |
ac89a917 | 116 | static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c) |
1da177e4 LT |
117 | { |
118 | struct tty_struct *to = tty->link; | |
1da177e4 | 119 | |
d945cb9c | 120 | if (tty->stopped) |
1da177e4 | 121 | return 0; |
d945cb9c | 122 | |
d945cb9c AC |
123 | if (c > 0) { |
124 | /* Stuff the data into the input queue of the other end */ | |
125 | c = tty_insert_flip_string(to, buf, c); | |
126 | /* And shovel */ | |
202c4675 LT |
127 | if (c) { |
128 | tty_flip_buffer_push(to); | |
129 | tty_wakeup(tty); | |
130 | } | |
762faaed | 131 | } |
1da177e4 LT |
132 | return c; |
133 | } | |
134 | ||
d945cb9c AC |
135 | /** |
136 | * pty_write_room - write space | |
137 | * @tty: tty we are writing from | |
138 | * | |
139 | * Report how many bytes the ldisc can send into the queue for | |
140 | * the other device. | |
141 | */ | |
142 | ||
1da177e4 LT |
143 | static int pty_write_room(struct tty_struct *tty) |
144 | { | |
85dfd81d LT |
145 | if (tty->stopped) |
146 | return 0; | |
d945cb9c | 147 | return pty_space(tty->link); |
1da177e4 LT |
148 | } |
149 | ||
d945cb9c AC |
150 | /** |
151 | * pty_chars_in_buffer - characters currently in our tx queue | |
152 | * @tty: our tty | |
fe9cd962 | 153 | * |
d945cb9c AC |
154 | * Report how much we have in the transmit queue. As everything is |
155 | * instantly at the other end this is easy to implement. | |
1da177e4 | 156 | */ |
d945cb9c | 157 | |
1da177e4 LT |
158 | static int pty_chars_in_buffer(struct tty_struct *tty) |
159 | { | |
d945cb9c | 160 | return 0; |
1da177e4 LT |
161 | } |
162 | ||
163 | /* Set the lock flag on a pty */ | |
fe9cd962 | 164 | static int pty_set_lock(struct tty_struct *tty, int __user *arg) |
1da177e4 LT |
165 | { |
166 | int val; | |
fe9cd962 | 167 | if (get_user(val, arg)) |
1da177e4 LT |
168 | return -EFAULT; |
169 | if (val) | |
170 | set_bit(TTY_PTY_LOCK, &tty->flags); | |
171 | else | |
172 | clear_bit(TTY_PTY_LOCK, &tty->flags); | |
173 | return 0; | |
174 | } | |
175 | ||
26df6d13 | 176 | /* Send a signal to the slave */ |
177 | static int pty_signal(struct tty_struct *tty, int sig) | |
178 | { | |
179 | unsigned long flags; | |
180 | struct pid *pgrp; | |
181 | ||
182 | if (tty->link) { | |
183 | spin_lock_irqsave(&tty->link->ctrl_lock, flags); | |
184 | pgrp = get_pid(tty->link->pgrp); | |
185 | spin_unlock_irqrestore(&tty->link->ctrl_lock, flags); | |
186 | ||
187 | kill_pgrp(pgrp, sig, 1); | |
188 | put_pid(pgrp); | |
189 | } | |
190 | return 0; | |
191 | } | |
192 | ||
1da177e4 LT |
193 | static void pty_flush_buffer(struct tty_struct *tty) |
194 | { | |
195 | struct tty_struct *to = tty->link; | |
04f378b1 | 196 | unsigned long flags; |
fe9cd962 | 197 | |
1da177e4 LT |
198 | if (!to) |
199 | return; | |
d945cb9c | 200 | /* tty_buffer_flush(to); FIXME */ |
1da177e4 | 201 | if (to->packet) { |
04f378b1 | 202 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
1da177e4 LT |
203 | tty->ctrl_status |= TIOCPKT_FLUSHWRITE; |
204 | wake_up_interruptible(&to->read_wait); | |
04f378b1 | 205 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
1da177e4 LT |
206 | } |
207 | } | |
208 | ||
fe9cd962 | 209 | static int pty_open(struct tty_struct *tty, struct file *filp) |
1da177e4 LT |
210 | { |
211 | int retval = -ENODEV; | |
212 | ||
213 | if (!tty || !tty->link) | |
214 | goto out; | |
215 | ||
216 | retval = -EIO; | |
217 | if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) | |
218 | goto out; | |
219 | if (test_bit(TTY_PTY_LOCK, &tty->link->flags)) | |
220 | goto out; | |
221 | if (tty->link->count != 1) | |
222 | goto out; | |
223 | ||
224 | clear_bit(TTY_OTHER_CLOSED, &tty->link->flags); | |
225 | set_bit(TTY_THROTTLED, &tty->flags); | |
1da177e4 LT |
226 | retval = 0; |
227 | out: | |
228 | return retval; | |
229 | } | |
230 | ||
fe9cd962 AC |
231 | static void pty_set_termios(struct tty_struct *tty, |
232 | struct ktermios *old_termios) | |
1da177e4 | 233 | { |
adc8d746 AC |
234 | tty->termios.c_cflag &= ~(CSIZE | PARENB); |
235 | tty->termios.c_cflag |= (CS8 | CREAD); | |
1da177e4 LT |
236 | } |
237 | ||
fc6f6238 AC |
238 | /** |
239 | * pty_do_resize - resize event | |
240 | * @tty: tty being resized | |
c774bda2 | 241 | * @ws: window size being set. |
fc6f6238 | 242 | * |
3ad2f3fb | 243 | * Update the termios variables and send the necessary signals to |
fc6f6238 AC |
244 | * peform a terminal resize correctly |
245 | */ | |
246 | ||
247 | int pty_resize(struct tty_struct *tty, struct winsize *ws) | |
248 | { | |
249 | struct pid *pgrp, *rpgrp; | |
250 | unsigned long flags; | |
251 | struct tty_struct *pty = tty->link; | |
252 | ||
253 | /* For a PTY we need to lock the tty side */ | |
254 | mutex_lock(&tty->termios_mutex); | |
255 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) | |
256 | goto done; | |
257 | ||
258 | /* Get the PID values and reference them so we can | |
259 | avoid holding the tty ctrl lock while sending signals. | |
260 | We need to lock these individually however. */ | |
261 | ||
262 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
263 | pgrp = get_pid(tty->pgrp); | |
264 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
265 | ||
266 | spin_lock_irqsave(&pty->ctrl_lock, flags); | |
267 | rpgrp = get_pid(pty->pgrp); | |
268 | spin_unlock_irqrestore(&pty->ctrl_lock, flags); | |
269 | ||
270 | if (pgrp) | |
271 | kill_pgrp(pgrp, SIGWINCH, 1); | |
272 | if (rpgrp != pgrp && rpgrp) | |
273 | kill_pgrp(rpgrp, SIGWINCH, 1); | |
274 | ||
275 | put_pid(pgrp); | |
276 | put_pid(rpgrp); | |
277 | ||
278 | tty->winsize = *ws; | |
279 | pty->winsize = *ws; /* Never used so will go away soon */ | |
280 | done: | |
281 | mutex_unlock(&tty->termios_mutex); | |
282 | return 0; | |
283 | } | |
284 | ||
5d249bc6 JS |
285 | static int pty_common_install(struct tty_driver *driver, struct tty_struct *tty, |
286 | bool legacy) | |
bf970ee4 AC |
287 | { |
288 | struct tty_struct *o_tty; | |
d03702a2 | 289 | struct tty_port *ports[2]; |
bf970ee4 | 290 | int idx = tty->index; |
5d249bc6 | 291 | int retval = -ENOMEM; |
bf970ee4 AC |
292 | |
293 | o_tty = alloc_tty_struct(); | |
d03702a2 JS |
294 | ports[0] = kmalloc(sizeof **ports, GFP_KERNEL); |
295 | ports[1] = kmalloc(sizeof **ports, GFP_KERNEL); | |
296 | if (!o_tty || !ports[0] || !ports[1]) | |
297 | goto err_free_tty; | |
bf970ee4 AC |
298 | if (!try_module_get(driver->other->owner)) { |
299 | /* This cannot in fact currently happen */ | |
8a1b8d70 | 300 | goto err_free_tty; |
bf970ee4 AC |
301 | } |
302 | initialize_tty_struct(o_tty, driver->other, idx); | |
303 | ||
5d249bc6 JS |
304 | if (legacy) { |
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) | |
309 | goto err_deinit_tty; | |
310 | ||
311 | retval = tty_init_termios(o_tty); | |
312 | if (retval) | |
313 | goto err_free_termios; | |
314 | ||
315 | driver->other->ttys[idx] = o_tty; | |
316 | driver->ttys[idx] = tty; | |
317 | } else { | |
adc8d746 AC |
318 | memset(&tty->termios_locked, 0, sizeof(tty->termios_locked)); |
319 | tty->termios = driver->init_termios; | |
320 | memset(&o_tty->termios_locked, 0, sizeof(tty->termios_locked)); | |
321 | o_tty->termios = driver->other->init_termios; | |
5d249bc6 | 322 | } |
fe9cd962 | 323 | |
bf970ee4 AC |
324 | /* |
325 | * Everything allocated ... set up the o_tty structure. | |
326 | */ | |
bf970ee4 AC |
327 | tty_driver_kref_get(driver->other); |
328 | if (driver->subtype == PTY_TYPE_MASTER) | |
329 | o_tty->count++; | |
330 | /* Establish the links in both directions */ | |
331 | tty->link = o_tty; | |
332 | o_tty->link = tty; | |
d03702a2 JS |
333 | tty_port_init(ports[0]); |
334 | tty_port_init(ports[1]); | |
335 | o_tty->port = ports[0]; | |
336 | tty->port = ports[1]; | |
bf970ee4 AC |
337 | |
338 | tty_driver_kref_get(driver); | |
339 | tty->count++; | |
bf970ee4 | 340 | return 0; |
8a1b8d70 | 341 | err_free_termios: |
5d249bc6 JS |
342 | if (legacy) |
343 | tty_free_termios(tty); | |
a9dccddb JS |
344 | err_deinit_tty: |
345 | deinitialize_tty_struct(o_tty); | |
bf970ee4 | 346 | module_put(o_tty->driver->owner); |
8a1b8d70 | 347 | err_free_tty: |
d03702a2 JS |
348 | kfree(ports[0]); |
349 | kfree(ports[1]); | |
bf970ee4 | 350 | free_tty_struct(o_tty); |
8a1b8d70 | 351 | return retval; |
bf970ee4 AC |
352 | } |
353 | ||
d03702a2 JS |
354 | static void pty_cleanup(struct tty_struct *tty) |
355 | { | |
356 | kfree(tty->port); | |
357 | } | |
358 | ||
5d249bc6 JS |
359 | /* Traditional BSD devices */ |
360 | #ifdef CONFIG_LEGACY_PTYS | |
361 | ||
362 | static int pty_install(struct tty_driver *driver, struct tty_struct *tty) | |
363 | { | |
364 | return pty_common_install(driver, tty, true); | |
365 | } | |
366 | ||
6caa76b7 | 367 | static int pty_bsd_ioctl(struct tty_struct *tty, |
1da177e4 LT |
368 | unsigned int cmd, unsigned long arg) |
369 | { | |
370 | switch (cmd) { | |
371 | case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */ | |
372 | return pty_set_lock(tty, (int __user *) arg); | |
26df6d13 | 373 | case TIOCSIG: /* Send signal to other side of pty */ |
374 | return pty_signal(tty, (int) arg); | |
1da177e4 LT |
375 | } |
376 | return -ENOIOCTLCMD; | |
377 | } | |
378 | ||
dc8c8587 KS |
379 | static int legacy_count = CONFIG_LEGACY_PTY_COUNT; |
380 | module_param(legacy_count, int, 0); | |
381 | ||
342a5971 LT |
382 | /* |
383 | * The master side of a pty can do TIOCSPTLCK and thus | |
384 | * has pty_bsd_ioctl. | |
385 | */ | |
386 | static const struct tty_operations master_pty_ops_bsd = { | |
387 | .install = pty_install, | |
3e8e88ca AC |
388 | .open = pty_open, |
389 | .close = pty_close, | |
390 | .write = pty_write, | |
391 | .write_room = pty_write_room, | |
392 | .flush_buffer = pty_flush_buffer, | |
393 | .chars_in_buffer = pty_chars_in_buffer, | |
394 | .unthrottle = pty_unthrottle, | |
395 | .set_termios = pty_set_termios, | |
396 | .ioctl = pty_bsd_ioctl, | |
d03702a2 | 397 | .cleanup = pty_cleanup, |
fc6f6238 | 398 | .resize = pty_resize |
3e8e88ca AC |
399 | }; |
400 | ||
342a5971 LT |
401 | static const struct tty_operations slave_pty_ops_bsd = { |
402 | .install = pty_install, | |
403 | .open = pty_open, | |
404 | .close = pty_close, | |
405 | .write = pty_write, | |
406 | .write_room = pty_write_room, | |
407 | .flush_buffer = pty_flush_buffer, | |
408 | .chars_in_buffer = pty_chars_in_buffer, | |
409 | .unthrottle = pty_unthrottle, | |
410 | .set_termios = pty_set_termios, | |
d03702a2 | 411 | .cleanup = pty_cleanup, |
342a5971 LT |
412 | .resize = pty_resize |
413 | }; | |
414 | ||
1da177e4 LT |
415 | static void __init legacy_pty_init(void) |
416 | { | |
342a5971 LT |
417 | struct tty_driver *pty_driver, *pty_slave_driver; |
418 | ||
dc8c8587 KS |
419 | if (legacy_count <= 0) |
420 | return; | |
1da177e4 | 421 | |
dc8c8587 | 422 | pty_driver = alloc_tty_driver(legacy_count); |
1da177e4 LT |
423 | if (!pty_driver) |
424 | panic("Couldn't allocate pty driver"); | |
425 | ||
dc8c8587 | 426 | pty_slave_driver = alloc_tty_driver(legacy_count); |
1da177e4 LT |
427 | if (!pty_slave_driver) |
428 | panic("Couldn't allocate pty slave driver"); | |
429 | ||
1da177e4 LT |
430 | pty_driver->driver_name = "pty_master"; |
431 | pty_driver->name = "pty"; | |
1da177e4 LT |
432 | pty_driver->major = PTY_MASTER_MAJOR; |
433 | pty_driver->minor_start = 0; | |
434 | pty_driver->type = TTY_DRIVER_TYPE_PTY; | |
435 | pty_driver->subtype = PTY_TYPE_MASTER; | |
436 | pty_driver->init_termios = tty_std_termios; | |
437 | pty_driver->init_termios.c_iflag = 0; | |
438 | pty_driver->init_termios.c_oflag = 0; | |
439 | pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
440 | pty_driver->init_termios.c_lflag = 0; | |
606d099c AC |
441 | pty_driver->init_termios.c_ispeed = 38400; |
442 | pty_driver->init_termios.c_ospeed = 38400; | |
1da177e4 LT |
443 | pty_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW; |
444 | pty_driver->other = pty_slave_driver; | |
342a5971 | 445 | tty_set_operations(pty_driver, &master_pty_ops_bsd); |
1da177e4 | 446 | |
1da177e4 LT |
447 | pty_slave_driver->driver_name = "pty_slave"; |
448 | pty_slave_driver->name = "ttyp"; | |
1da177e4 LT |
449 | pty_slave_driver->major = PTY_SLAVE_MAJOR; |
450 | pty_slave_driver->minor_start = 0; | |
451 | pty_slave_driver->type = TTY_DRIVER_TYPE_PTY; | |
452 | pty_slave_driver->subtype = PTY_TYPE_SLAVE; | |
453 | pty_slave_driver->init_termios = tty_std_termios; | |
454 | pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
606d099c AC |
455 | pty_slave_driver->init_termios.c_ispeed = 38400; |
456 | pty_slave_driver->init_termios.c_ospeed = 38400; | |
1da177e4 LT |
457 | pty_slave_driver->flags = TTY_DRIVER_RESET_TERMIOS | |
458 | TTY_DRIVER_REAL_RAW; | |
459 | pty_slave_driver->other = pty_driver; | |
342a5971 | 460 | tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd); |
1da177e4 LT |
461 | |
462 | if (tty_register_driver(pty_driver)) | |
463 | panic("Couldn't register pty driver"); | |
464 | if (tty_register_driver(pty_slave_driver)) | |
465 | panic("Couldn't register pty slave driver"); | |
466 | } | |
467 | #else | |
468 | static inline void legacy_pty_init(void) { } | |
469 | #endif | |
470 | ||
471 | /* Unix98 devices */ | |
472 | #ifdef CONFIG_UNIX98_PTYS | |
1da177e4 | 473 | |
d81ed103 AC |
474 | static struct cdev ptmx_cdev; |
475 | ||
6caa76b7 | 476 | static int pty_unix98_ioctl(struct tty_struct *tty, |
1da177e4 LT |
477 | unsigned int cmd, unsigned long arg) |
478 | { | |
479 | switch (cmd) { | |
480 | case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */ | |
481 | return pty_set_lock(tty, (int __user *)arg); | |
482 | case TIOCGPTN: /* Get PT Number */ | |
483 | return put_user(tty->index, (unsigned int __user *)arg); | |
26df6d13 | 484 | case TIOCSIG: /* Send signal to other side of pty */ |
485 | return pty_signal(tty, (int) arg); | |
1da177e4 LT |
486 | } |
487 | ||
488 | return -ENOIOCTLCMD; | |
489 | } | |
490 | ||
99f1fe18 AC |
491 | /** |
492 | * ptm_unix98_lookup - find a pty master | |
493 | * @driver: ptm driver | |
494 | * @idx: tty index | |
495 | * | |
496 | * Look up a pty master device. Called under the tty_mutex for now. | |
497 | * This provides our locking. | |
498 | */ | |
499 | ||
15f1a633 SB |
500 | static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver, |
501 | struct inode *ptm_inode, int idx) | |
99f1fe18 | 502 | { |
593a27c4 KK |
503 | /* Master must be open via /dev/ptmx */ |
504 | return ERR_PTR(-EIO); | |
99f1fe18 AC |
505 | } |
506 | ||
507 | /** | |
508 | * pts_unix98_lookup - find a pty slave | |
509 | * @driver: pts driver | |
510 | * @idx: tty index | |
511 | * | |
512 | * Look up a pty master device. Called under the tty_mutex for now. | |
d739e65b | 513 | * This provides our locking for the tty pointer. |
99f1fe18 AC |
514 | */ |
515 | ||
15f1a633 SB |
516 | static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver, |
517 | struct inode *pts_inode, int idx) | |
99f1fe18 | 518 | { |
d739e65b AC |
519 | struct tty_struct *tty; |
520 | ||
521 | mutex_lock(&devpts_mutex); | |
522 | tty = devpts_get_tty(pts_inode, idx); | |
523 | mutex_unlock(&devpts_mutex); | |
99f1fe18 AC |
524 | /* Master must be open before slave */ |
525 | if (!tty) | |
526 | return ERR_PTR(-EIO); | |
527 | return tty; | |
528 | } | |
529 | ||
8b0a88d5 AC |
530 | /* We have no need to install and remove our tty objects as devpts does all |
531 | the work for us */ | |
532 | ||
bf970ee4 | 533 | static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 | 534 | { |
5d249bc6 | 535 | return pty_common_install(driver, tty, false); |
8b0a88d5 AC |
536 | } |
537 | ||
7171604a | 538 | static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 AC |
539 | { |
540 | } | |
541 | ||
feebed65 | 542 | static const struct tty_operations ptm_unix98_ops = { |
99f1fe18 | 543 | .lookup = ptm_unix98_lookup, |
bf970ee4 | 544 | .install = pty_unix98_install, |
7171604a | 545 | .remove = pty_unix98_remove, |
3e8e88ca AC |
546 | .open = pty_open, |
547 | .close = pty_close, | |
548 | .write = pty_write, | |
549 | .write_room = pty_write_room, | |
550 | .flush_buffer = pty_flush_buffer, | |
551 | .chars_in_buffer = pty_chars_in_buffer, | |
552 | .unthrottle = pty_unthrottle, | |
553 | .set_termios = pty_set_termios, | |
feebed65 | 554 | .ioctl = pty_unix98_ioctl, |
36b3c070 AC |
555 | .resize = pty_resize, |
556 | .cleanup = pty_cleanup | |
3e8e88ca AC |
557 | }; |
558 | ||
99f1fe18 AC |
559 | static const struct tty_operations pty_unix98_ops = { |
560 | .lookup = pts_unix98_lookup, | |
bf970ee4 | 561 | .install = pty_unix98_install, |
7171604a | 562 | .remove = pty_unix98_remove, |
99f1fe18 AC |
563 | .open = pty_open, |
564 | .close = pty_close, | |
565 | .write = pty_write, | |
566 | .write_room = pty_write_room, | |
567 | .flush_buffer = pty_flush_buffer, | |
568 | .chars_in_buffer = pty_chars_in_buffer, | |
569 | .unthrottle = pty_unthrottle, | |
570 | .set_termios = pty_set_termios, | |
d03702a2 | 571 | .cleanup = pty_cleanup, |
99f1fe18 | 572 | }; |
d81ed103 AC |
573 | |
574 | /** | |
575 | * ptmx_open - open a unix 98 pty master | |
576 | * @inode: inode of device file | |
577 | * @filp: file pointer to tty | |
578 | * | |
579 | * Allocate a unix98 pty master device from the ptmx driver. | |
580 | * | |
581 | * Locking: tty_mutex protects the init_dev work. tty->count should | |
582 | * protect the rest. | |
583 | * allocated_ptys_lock handles the list of free pty numbers | |
584 | */ | |
585 | ||
64ba3dc3 | 586 | static int ptmx_open(struct inode *inode, struct file *filp) |
d81ed103 AC |
587 | { |
588 | struct tty_struct *tty; | |
589 | int retval; | |
590 | int index; | |
591 | ||
592 | nonseekable_open(inode, filp); | |
593 | ||
fa90e1c9 JS |
594 | retval = tty_alloc_file(filp); |
595 | if (retval) | |
596 | return retval; | |
597 | ||
d81ed103 | 598 | /* find a device that is not in use. */ |
6d31a88c | 599 | tty_lock(); |
15f1a633 | 600 | index = devpts_new_index(inode); |
6d31a88c | 601 | tty_unlock(); |
fa90e1c9 JS |
602 | if (index < 0) { |
603 | retval = index; | |
604 | goto err_file; | |
605 | } | |
d81ed103 AC |
606 | |
607 | mutex_lock(&tty_mutex); | |
6d31a88c | 608 | mutex_lock(&devpts_mutex); |
593a27c4 | 609 | tty = tty_init_dev(ptm_driver, index); |
6d31a88c AC |
610 | mutex_unlock(&devpts_mutex); |
611 | tty_lock(); | |
612 | mutex_unlock(&tty_mutex); | |
d81ed103 | 613 | |
73ec06fc AC |
614 | if (IS_ERR(tty)) { |
615 | retval = PTR_ERR(tty); | |
d81ed103 | 616 | goto out; |
73ec06fc | 617 | } |
d81ed103 AC |
618 | |
619 | set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ | |
ee2ffa0d | 620 | |
fa90e1c9 | 621 | tty_add_file(tty, filp); |
d81ed103 | 622 | |
15f1a633 | 623 | retval = devpts_pty_new(inode, tty->link); |
d81ed103 | 624 | if (retval) |
1177c0ef | 625 | goto err_release; |
d81ed103 AC |
626 | |
627 | retval = ptm_driver->ops->open(tty, filp); | |
64ba3dc3 | 628 | if (retval) |
1177c0ef JS |
629 | goto err_release; |
630 | ||
6d31a88c | 631 | tty_unlock(); |
1177c0ef JS |
632 | return 0; |
633 | err_release: | |
6d31a88c | 634 | tty_unlock(); |
eeb89d91 | 635 | tty_release(inode, filp); |
d81ed103 AC |
636 | return retval; |
637 | out: | |
d3bda529 | 638 | devpts_kill_index(inode, index); |
6d31a88c | 639 | tty_unlock(); |
fa90e1c9 JS |
640 | err_file: |
641 | tty_free_file(filp); | |
64ba3dc3 | 642 | return retval; |
d81ed103 AC |
643 | } |
644 | ||
645 | static struct file_operations ptmx_fops; | |
646 | ||
1da177e4 LT |
647 | static void __init unix98_pty_init(void) |
648 | { | |
1da177e4 LT |
649 | ptm_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX); |
650 | if (!ptm_driver) | |
651 | panic("Couldn't allocate Unix98 ptm driver"); | |
652 | pts_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX); | |
653 | if (!pts_driver) | |
654 | panic("Couldn't allocate Unix98 pts driver"); | |
655 | ||
1da177e4 LT |
656 | ptm_driver->driver_name = "pty_master"; |
657 | ptm_driver->name = "ptm"; | |
658 | ptm_driver->major = UNIX98_PTY_MASTER_MAJOR; | |
659 | ptm_driver->minor_start = 0; | |
660 | ptm_driver->type = TTY_DRIVER_TYPE_PTY; | |
661 | ptm_driver->subtype = PTY_TYPE_MASTER; | |
662 | ptm_driver->init_termios = tty_std_termios; | |
663 | ptm_driver->init_termios.c_iflag = 0; | |
664 | ptm_driver->init_termios.c_oflag = 0; | |
665 | ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
666 | ptm_driver->init_termios.c_lflag = 0; | |
606d099c AC |
667 | ptm_driver->init_termios.c_ispeed = 38400; |
668 | ptm_driver->init_termios.c_ospeed = 38400; | |
1da177e4 | 669 | ptm_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | |
331b8319 | 670 | TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM; |
1da177e4 | 671 | ptm_driver->other = pts_driver; |
feebed65 | 672 | tty_set_operations(ptm_driver, &ptm_unix98_ops); |
1da177e4 | 673 | |
1da177e4 LT |
674 | pts_driver->driver_name = "pty_slave"; |
675 | pts_driver->name = "pts"; | |
676 | pts_driver->major = UNIX98_PTY_SLAVE_MAJOR; | |
677 | pts_driver->minor_start = 0; | |
678 | pts_driver->type = TTY_DRIVER_TYPE_PTY; | |
679 | pts_driver->subtype = PTY_TYPE_SLAVE; | |
680 | pts_driver->init_termios = tty_std_termios; | |
681 | pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
606d099c AC |
682 | pts_driver->init_termios.c_ispeed = 38400; |
683 | pts_driver->init_termios.c_ospeed = 38400; | |
1da177e4 | 684 | pts_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | |
331b8319 | 685 | TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM; |
1da177e4 | 686 | pts_driver->other = ptm_driver; |
99f1fe18 | 687 | tty_set_operations(pts_driver, &pty_unix98_ops); |
fe9cd962 | 688 | |
1da177e4 LT |
689 | if (tty_register_driver(ptm_driver)) |
690 | panic("Couldn't register Unix98 ptm driver"); | |
691 | if (tty_register_driver(pts_driver)) | |
692 | panic("Couldn't register Unix98 pts driver"); | |
693 | ||
d81ed103 AC |
694 | /* Now create the /dev/ptmx special device */ |
695 | tty_default_fops(&ptmx_fops); | |
696 | ptmx_fops.open = ptmx_open; | |
697 | ||
698 | cdev_init(&ptmx_cdev, &ptmx_fops); | |
699 | if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) || | |
700 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0) | |
701 | panic("Couldn't register /dev/ptmx driver\n"); | |
702 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx"); | |
1da177e4 | 703 | } |
d81ed103 | 704 | |
1da177e4 LT |
705 | #else |
706 | static inline void unix98_pty_init(void) { } | |
707 | #endif | |
708 | ||
709 | static int __init pty_init(void) | |
710 | { | |
711 | legacy_pty_init(); | |
712 | unix98_pty_init(); | |
713 | return 0; | |
714 | } | |
715 | module_init(pty_init); |