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> | |
d43c36dc | 21 | #include <linux/sched.h> |
1da177e4 LT |
22 | #include <linux/string.h> |
23 | #include <linux/major.h> | |
24 | #include <linux/mm.h> | |
25 | #include <linux/init.h> | |
405f5571 | 26 | #include <linux/smp_lock.h> |
1da177e4 | 27 | #include <linux/sysctl.h> |
d81ed103 | 28 | #include <linux/device.h> |
fe9cd962 | 29 | #include <linux/uaccess.h> |
1da177e4 LT |
30 | #include <linux/bitops.h> |
31 | #include <linux/devpts_fs.h> | |
5a0e3ad6 | 32 | #include <linux/slab.h> |
1da177e4 | 33 | |
fe9cd962 AC |
34 | #include <asm/system.h> |
35 | ||
1da177e4 | 36 | #ifdef CONFIG_UNIX98_PTYS |
da2bdf9a | 37 | static struct tty_driver *ptm_driver; |
1da177e4 LT |
38 | static struct tty_driver *pts_driver; |
39 | #endif | |
40 | ||
fe9cd962 | 41 | static void pty_close(struct tty_struct *tty, struct file *filp) |
1da177e4 | 42 | { |
fe9cd962 AC |
43 | BUG_ON(!tty); |
44 | if (tty->driver->subtype == PTY_TYPE_MASTER) | |
45 | WARN_ON(tty->count > 1); | |
46 | else { | |
1da177e4 LT |
47 | if (tty->count > 2) |
48 | return; | |
49 | } | |
50 | wake_up_interruptible(&tty->read_wait); | |
51 | wake_up_interruptible(&tty->write_wait); | |
52 | tty->packet = 0; | |
53 | if (!tty->link) | |
54 | return; | |
55 | tty->link->packet = 0; | |
56 | set_bit(TTY_OTHER_CLOSED, &tty->link->flags); | |
57 | wake_up_interruptible(&tty->link->read_wait); | |
58 | wake_up_interruptible(&tty->link->write_wait); | |
59 | if (tty->driver->subtype == PTY_TYPE_MASTER) { | |
60 | set_bit(TTY_OTHER_CLOSED, &tty->flags); | |
61 | #ifdef CONFIG_UNIX98_PTYS | |
62 | if (tty->driver == ptm_driver) | |
15f1a633 | 63 | devpts_pty_kill(tty->link); |
1da177e4 LT |
64 | #endif |
65 | tty_vhangup(tty->link); | |
66 | } | |
67 | } | |
68 | ||
69 | /* | |
70 | * The unthrottle routine is called by the line discipline to signal | |
71 | * that it can receive more characters. For PTY's, the TTY_THROTTLED | |
72 | * flag is always set, to force the line discipline to always call the | |
fe9cd962 | 73 | * unthrottle routine when there are fewer than TTY_THRESHOLD_UNTHROTTLE |
1da177e4 LT |
74 | * characters in the queue. This is necessary since each time this |
75 | * happens, we need to wake up any sleeping processes that could be | |
76 | * (1) trying to send data to the pty, or (2) waiting in wait_until_sent() | |
77 | * for the pty buffer to be drained. | |
78 | */ | |
fe9cd962 | 79 | static void pty_unthrottle(struct tty_struct *tty) |
1da177e4 | 80 | { |
d945cb9c | 81 | tty_wakeup(tty->link); |
1da177e4 LT |
82 | set_bit(TTY_THROTTLED, &tty->flags); |
83 | } | |
84 | ||
d945cb9c AC |
85 | /** |
86 | * pty_space - report space left for writing | |
87 | * @to: tty we are writing into | |
1da177e4 | 88 | * |
d945cb9c AC |
89 | * The tty buffers allow 64K but we sneak a peak and clip at 8K this |
90 | * allows a lot of overspill room for echo and other fun messes to | |
91 | * be handled properly | |
92 | */ | |
93 | ||
94 | static int pty_space(struct tty_struct *to) | |
95 | { | |
96 | int n = 8192 - to->buf.memory_used; | |
97 | if (n < 0) | |
98 | return 0; | |
99 | return n; | |
100 | } | |
101 | ||
102 | /** | |
103 | * pty_write - write to a pty | |
104 | * @tty: the tty we write from | |
105 | * @buf: kernel buffer of data | |
106 | * @count: bytes to write | |
762faaed | 107 | * |
d945cb9c AC |
108 | * Our "hardware" write method. Data is coming from the ldisc which |
109 | * may be in a non sleeping state. We simply throw this at the other | |
110 | * end of the link as if we were an IRQ handler receiving stuff for | |
111 | * the other side of the pty/tty pair. | |
1da177e4 | 112 | */ |
d945cb9c | 113 | |
ac89a917 | 114 | static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c) |
1da177e4 LT |
115 | { |
116 | struct tty_struct *to = tty->link; | |
1da177e4 | 117 | |
d945cb9c | 118 | if (tty->stopped) |
1da177e4 | 119 | return 0; |
d945cb9c | 120 | |
d945cb9c AC |
121 | if (c > 0) { |
122 | /* Stuff the data into the input queue of the other end */ | |
123 | c = tty_insert_flip_string(to, buf, c); | |
124 | /* And shovel */ | |
202c4675 LT |
125 | if (c) { |
126 | tty_flip_buffer_push(to); | |
127 | tty_wakeup(tty); | |
128 | } | |
762faaed | 129 | } |
1da177e4 LT |
130 | return c; |
131 | } | |
132 | ||
d945cb9c AC |
133 | /** |
134 | * pty_write_room - write space | |
135 | * @tty: tty we are writing from | |
136 | * | |
137 | * Report how many bytes the ldisc can send into the queue for | |
138 | * the other device. | |
139 | */ | |
140 | ||
1da177e4 LT |
141 | static int pty_write_room(struct tty_struct *tty) |
142 | { | |
85dfd81d LT |
143 | if (tty->stopped) |
144 | return 0; | |
d945cb9c | 145 | return pty_space(tty->link); |
1da177e4 LT |
146 | } |
147 | ||
d945cb9c AC |
148 | /** |
149 | * pty_chars_in_buffer - characters currently in our tx queue | |
150 | * @tty: our tty | |
fe9cd962 | 151 | * |
d945cb9c AC |
152 | * Report how much we have in the transmit queue. As everything is |
153 | * instantly at the other end this is easy to implement. | |
1da177e4 | 154 | */ |
d945cb9c | 155 | |
1da177e4 LT |
156 | static int pty_chars_in_buffer(struct tty_struct *tty) |
157 | { | |
d945cb9c | 158 | return 0; |
1da177e4 LT |
159 | } |
160 | ||
161 | /* Set the lock flag on a pty */ | |
fe9cd962 | 162 | static int pty_set_lock(struct tty_struct *tty, int __user *arg) |
1da177e4 LT |
163 | { |
164 | int val; | |
fe9cd962 | 165 | if (get_user(val, arg)) |
1da177e4 LT |
166 | return -EFAULT; |
167 | if (val) | |
168 | set_bit(TTY_PTY_LOCK, &tty->flags); | |
169 | else | |
170 | clear_bit(TTY_PTY_LOCK, &tty->flags); | |
171 | return 0; | |
172 | } | |
173 | ||
26df6d13 | 174 | /* Send a signal to the slave */ |
175 | static int pty_signal(struct tty_struct *tty, int sig) | |
176 | { | |
177 | unsigned long flags; | |
178 | struct pid *pgrp; | |
179 | ||
180 | if (tty->link) { | |
181 | spin_lock_irqsave(&tty->link->ctrl_lock, flags); | |
182 | pgrp = get_pid(tty->link->pgrp); | |
183 | spin_unlock_irqrestore(&tty->link->ctrl_lock, flags); | |
184 | ||
185 | kill_pgrp(pgrp, sig, 1); | |
186 | put_pid(pgrp); | |
187 | } | |
188 | return 0; | |
189 | } | |
190 | ||
1da177e4 LT |
191 | static void pty_flush_buffer(struct tty_struct *tty) |
192 | { | |
193 | struct tty_struct *to = tty->link; | |
04f378b1 | 194 | unsigned long flags; |
fe9cd962 | 195 | |
1da177e4 LT |
196 | if (!to) |
197 | return; | |
d945cb9c | 198 | /* tty_buffer_flush(to); FIXME */ |
1da177e4 | 199 | if (to->packet) { |
04f378b1 | 200 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
1da177e4 LT |
201 | tty->ctrl_status |= TIOCPKT_FLUSHWRITE; |
202 | wake_up_interruptible(&to->read_wait); | |
04f378b1 | 203 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
1da177e4 LT |
204 | } |
205 | } | |
206 | ||
fe9cd962 | 207 | static int pty_open(struct tty_struct *tty, struct file *filp) |
1da177e4 LT |
208 | { |
209 | int retval = -ENODEV; | |
210 | ||
211 | if (!tty || !tty->link) | |
212 | goto out; | |
213 | ||
214 | retval = -EIO; | |
215 | if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) | |
216 | goto out; | |
217 | if (test_bit(TTY_PTY_LOCK, &tty->link->flags)) | |
218 | goto out; | |
219 | if (tty->link->count != 1) | |
220 | goto out; | |
221 | ||
222 | clear_bit(TTY_OTHER_CLOSED, &tty->link->flags); | |
223 | set_bit(TTY_THROTTLED, &tty->flags); | |
1da177e4 LT |
224 | retval = 0; |
225 | out: | |
226 | return retval; | |
227 | } | |
228 | ||
fe9cd962 AC |
229 | static void pty_set_termios(struct tty_struct *tty, |
230 | struct ktermios *old_termios) | |
1da177e4 | 231 | { |
fe9cd962 AC |
232 | tty->termios->c_cflag &= ~(CSIZE | PARENB); |
233 | tty->termios->c_cflag |= (CS8 | CREAD); | |
1da177e4 LT |
234 | } |
235 | ||
fc6f6238 AC |
236 | /** |
237 | * pty_do_resize - resize event | |
238 | * @tty: tty being resized | |
c774bda2 | 239 | * @ws: window size being set. |
fc6f6238 | 240 | * |
3ad2f3fb | 241 | * Update the termios variables and send the necessary signals to |
fc6f6238 AC |
242 | * peform a terminal resize correctly |
243 | */ | |
244 | ||
245 | int pty_resize(struct tty_struct *tty, struct winsize *ws) | |
246 | { | |
247 | struct pid *pgrp, *rpgrp; | |
248 | unsigned long flags; | |
249 | struct tty_struct *pty = tty->link; | |
250 | ||
251 | /* For a PTY we need to lock the tty side */ | |
252 | mutex_lock(&tty->termios_mutex); | |
253 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) | |
254 | goto done; | |
255 | ||
256 | /* Get the PID values and reference them so we can | |
257 | avoid holding the tty ctrl lock while sending signals. | |
258 | We need to lock these individually however. */ | |
259 | ||
260 | spin_lock_irqsave(&tty->ctrl_lock, flags); | |
261 | pgrp = get_pid(tty->pgrp); | |
262 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); | |
263 | ||
264 | spin_lock_irqsave(&pty->ctrl_lock, flags); | |
265 | rpgrp = get_pid(pty->pgrp); | |
266 | spin_unlock_irqrestore(&pty->ctrl_lock, flags); | |
267 | ||
268 | if (pgrp) | |
269 | kill_pgrp(pgrp, SIGWINCH, 1); | |
270 | if (rpgrp != pgrp && rpgrp) | |
271 | kill_pgrp(rpgrp, SIGWINCH, 1); | |
272 | ||
273 | put_pid(pgrp); | |
274 | put_pid(rpgrp); | |
275 | ||
276 | tty->winsize = *ws; | |
277 | pty->winsize = *ws; /* Never used so will go away soon */ | |
278 | done: | |
279 | mutex_unlock(&tty->termios_mutex); | |
280 | return 0; | |
281 | } | |
282 | ||
342a5971 LT |
283 | /* Traditional BSD devices */ |
284 | #ifdef CONFIG_LEGACY_PTYS | |
285 | ||
bf970ee4 AC |
286 | static int pty_install(struct tty_driver *driver, struct tty_struct *tty) |
287 | { | |
288 | struct tty_struct *o_tty; | |
289 | int idx = tty->index; | |
290 | int retval; | |
291 | ||
292 | o_tty = alloc_tty_struct(); | |
293 | if (!o_tty) | |
294 | return -ENOMEM; | |
295 | if (!try_module_get(driver->other->owner)) { | |
296 | /* This cannot in fact currently happen */ | |
297 | free_tty_struct(o_tty); | |
298 | return -ENOMEM; | |
299 | } | |
300 | initialize_tty_struct(o_tty, driver->other, idx); | |
301 | ||
302 | /* We always use new tty termios data so we can do this | |
303 | the easy way .. */ | |
304 | retval = tty_init_termios(tty); | |
305 | if (retval) | |
306 | goto free_mem_out; | |
307 | ||
308 | retval = tty_init_termios(o_tty); | |
309 | if (retval) { | |
310 | tty_free_termios(tty); | |
311 | goto free_mem_out; | |
312 | } | |
fe9cd962 | 313 | |
bf970ee4 AC |
314 | /* |
315 | * Everything allocated ... set up the o_tty structure. | |
316 | */ | |
317 | driver->other->ttys[idx] = o_tty; | |
318 | tty_driver_kref_get(driver->other); | |
319 | if (driver->subtype == PTY_TYPE_MASTER) | |
320 | o_tty->count++; | |
321 | /* Establish the links in both directions */ | |
322 | tty->link = o_tty; | |
323 | o_tty->link = tty; | |
324 | ||
325 | tty_driver_kref_get(driver); | |
326 | tty->count++; | |
327 | driver->ttys[idx] = tty; | |
328 | return 0; | |
329 | free_mem_out: | |
330 | module_put(o_tty->driver->owner); | |
331 | free_tty_struct(o_tty); | |
332 | return -ENOMEM; | |
333 | } | |
334 | ||
1da177e4 LT |
335 | static int pty_bsd_ioctl(struct tty_struct *tty, struct file *file, |
336 | unsigned int cmd, unsigned long arg) | |
337 | { | |
338 | switch (cmd) { | |
339 | case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */ | |
340 | return pty_set_lock(tty, (int __user *) arg); | |
26df6d13 | 341 | case TIOCSIG: /* Send signal to other side of pty */ |
342 | return pty_signal(tty, (int) arg); | |
1da177e4 LT |
343 | } |
344 | return -ENOIOCTLCMD; | |
345 | } | |
346 | ||
dc8c8587 KS |
347 | static int legacy_count = CONFIG_LEGACY_PTY_COUNT; |
348 | module_param(legacy_count, int, 0); | |
349 | ||
342a5971 LT |
350 | /* |
351 | * The master side of a pty can do TIOCSPTLCK and thus | |
352 | * has pty_bsd_ioctl. | |
353 | */ | |
354 | static const struct tty_operations master_pty_ops_bsd = { | |
355 | .install = pty_install, | |
3e8e88ca AC |
356 | .open = pty_open, |
357 | .close = pty_close, | |
358 | .write = pty_write, | |
359 | .write_room = pty_write_room, | |
360 | .flush_buffer = pty_flush_buffer, | |
361 | .chars_in_buffer = pty_chars_in_buffer, | |
362 | .unthrottle = pty_unthrottle, | |
363 | .set_termios = pty_set_termios, | |
364 | .ioctl = pty_bsd_ioctl, | |
fc6f6238 | 365 | .resize = pty_resize |
3e8e88ca AC |
366 | }; |
367 | ||
342a5971 LT |
368 | static const struct tty_operations slave_pty_ops_bsd = { |
369 | .install = pty_install, | |
370 | .open = pty_open, | |
371 | .close = pty_close, | |
372 | .write = pty_write, | |
373 | .write_room = pty_write_room, | |
374 | .flush_buffer = pty_flush_buffer, | |
375 | .chars_in_buffer = pty_chars_in_buffer, | |
376 | .unthrottle = pty_unthrottle, | |
377 | .set_termios = pty_set_termios, | |
378 | .resize = pty_resize | |
379 | }; | |
380 | ||
1da177e4 LT |
381 | static void __init legacy_pty_init(void) |
382 | { | |
342a5971 LT |
383 | struct tty_driver *pty_driver, *pty_slave_driver; |
384 | ||
dc8c8587 KS |
385 | if (legacy_count <= 0) |
386 | return; | |
1da177e4 | 387 | |
dc8c8587 | 388 | pty_driver = alloc_tty_driver(legacy_count); |
1da177e4 LT |
389 | if (!pty_driver) |
390 | panic("Couldn't allocate pty driver"); | |
391 | ||
dc8c8587 | 392 | pty_slave_driver = alloc_tty_driver(legacy_count); |
1da177e4 LT |
393 | if (!pty_slave_driver) |
394 | panic("Couldn't allocate pty slave driver"); | |
395 | ||
396 | pty_driver->owner = THIS_MODULE; | |
397 | pty_driver->driver_name = "pty_master"; | |
398 | pty_driver->name = "pty"; | |
1da177e4 LT |
399 | pty_driver->major = PTY_MASTER_MAJOR; |
400 | pty_driver->minor_start = 0; | |
401 | pty_driver->type = TTY_DRIVER_TYPE_PTY; | |
402 | pty_driver->subtype = PTY_TYPE_MASTER; | |
403 | pty_driver->init_termios = tty_std_termios; | |
404 | pty_driver->init_termios.c_iflag = 0; | |
405 | pty_driver->init_termios.c_oflag = 0; | |
406 | pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
407 | pty_driver->init_termios.c_lflag = 0; | |
606d099c AC |
408 | pty_driver->init_termios.c_ispeed = 38400; |
409 | pty_driver->init_termios.c_ospeed = 38400; | |
1da177e4 LT |
410 | pty_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW; |
411 | pty_driver->other = pty_slave_driver; | |
342a5971 | 412 | tty_set_operations(pty_driver, &master_pty_ops_bsd); |
1da177e4 LT |
413 | |
414 | pty_slave_driver->owner = THIS_MODULE; | |
415 | pty_slave_driver->driver_name = "pty_slave"; | |
416 | pty_slave_driver->name = "ttyp"; | |
1da177e4 LT |
417 | pty_slave_driver->major = PTY_SLAVE_MAJOR; |
418 | pty_slave_driver->minor_start = 0; | |
419 | pty_slave_driver->type = TTY_DRIVER_TYPE_PTY; | |
420 | pty_slave_driver->subtype = PTY_TYPE_SLAVE; | |
421 | pty_slave_driver->init_termios = tty_std_termios; | |
422 | pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
606d099c AC |
423 | pty_slave_driver->init_termios.c_ispeed = 38400; |
424 | pty_slave_driver->init_termios.c_ospeed = 38400; | |
1da177e4 LT |
425 | pty_slave_driver->flags = TTY_DRIVER_RESET_TERMIOS | |
426 | TTY_DRIVER_REAL_RAW; | |
427 | pty_slave_driver->other = pty_driver; | |
342a5971 | 428 | tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd); |
1da177e4 LT |
429 | |
430 | if (tty_register_driver(pty_driver)) | |
431 | panic("Couldn't register pty driver"); | |
432 | if (tty_register_driver(pty_slave_driver)) | |
433 | panic("Couldn't register pty slave driver"); | |
434 | } | |
435 | #else | |
436 | static inline void legacy_pty_init(void) { } | |
437 | #endif | |
438 | ||
439 | /* Unix98 devices */ | |
440 | #ifdef CONFIG_UNIX98_PTYS | |
441 | /* | |
442 | * sysctl support for setting limits on the number of Unix98 ptys allocated. | |
443 | * Otherwise one can eat up all kernel memory by opening /dev/ptmx repeatedly. | |
444 | */ | |
445 | int pty_limit = NR_UNIX98_PTY_DEFAULT; | |
fe9cd962 | 446 | static int pty_limit_min; |
1da177e4 | 447 | static int pty_limit_max = NR_UNIX98_PTY_MAX; |
fe9cd962 | 448 | static int pty_count; |
1da177e4 | 449 | |
d81ed103 AC |
450 | static struct cdev ptmx_cdev; |
451 | ||
35834ca1 | 452 | static struct ctl_table pty_table[] = { |
1da177e4 | 453 | { |
1da177e4 LT |
454 | .procname = "max", |
455 | .maxlen = sizeof(int), | |
456 | .mode = 0644, | |
457 | .data = &pty_limit, | |
6d456111 | 458 | .proc_handler = proc_dointvec_minmax, |
1da177e4 LT |
459 | .extra1 = &pty_limit_min, |
460 | .extra2 = &pty_limit_max, | |
461 | }, { | |
1da177e4 LT |
462 | .procname = "nr", |
463 | .maxlen = sizeof(int), | |
464 | .mode = 0444, | |
bf970ee4 | 465 | .data = &pty_count, |
6d456111 | 466 | .proc_handler = proc_dointvec, |
894d2491 EB |
467 | }, |
468 | {} | |
1da177e4 LT |
469 | }; |
470 | ||
35834ca1 EB |
471 | static struct ctl_table pty_kern_table[] = { |
472 | { | |
35834ca1 EB |
473 | .procname = "pty", |
474 | .mode = 0555, | |
475 | .child = pty_table, | |
476 | }, | |
477 | {} | |
478 | }; | |
479 | ||
480 | static struct ctl_table pty_root_table[] = { | |
481 | { | |
35834ca1 EB |
482 | .procname = "kernel", |
483 | .mode = 0555, | |
484 | .child = pty_kern_table, | |
485 | }, | |
486 | {} | |
487 | }; | |
488 | ||
489 | ||
1da177e4 LT |
490 | static int pty_unix98_ioctl(struct tty_struct *tty, struct file *file, |
491 | unsigned int cmd, unsigned long arg) | |
492 | { | |
493 | switch (cmd) { | |
494 | case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */ | |
495 | return pty_set_lock(tty, (int __user *)arg); | |
496 | case TIOCGPTN: /* Get PT Number */ | |
497 | return put_user(tty->index, (unsigned int __user *)arg); | |
26df6d13 | 498 | case TIOCSIG: /* Send signal to other side of pty */ |
499 | return pty_signal(tty, (int) arg); | |
1da177e4 LT |
500 | } |
501 | ||
502 | return -ENOIOCTLCMD; | |
503 | } | |
504 | ||
99f1fe18 AC |
505 | /** |
506 | * ptm_unix98_lookup - find a pty master | |
507 | * @driver: ptm driver | |
508 | * @idx: tty index | |
509 | * | |
510 | * Look up a pty master device. Called under the tty_mutex for now. | |
511 | * This provides our locking. | |
512 | */ | |
513 | ||
15f1a633 SB |
514 | static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver, |
515 | struct inode *ptm_inode, int idx) | |
99f1fe18 | 516 | { |
15f1a633 | 517 | struct tty_struct *tty = devpts_get_tty(ptm_inode, idx); |
99f1fe18 AC |
518 | if (tty) |
519 | tty = tty->link; | |
520 | return tty; | |
521 | } | |
522 | ||
523 | /** | |
524 | * pts_unix98_lookup - find a pty slave | |
525 | * @driver: pts driver | |
526 | * @idx: tty index | |
527 | * | |
528 | * Look up a pty master device. Called under the tty_mutex for now. | |
529 | * This provides our locking. | |
530 | */ | |
531 | ||
15f1a633 SB |
532 | static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver, |
533 | struct inode *pts_inode, int idx) | |
99f1fe18 | 534 | { |
15f1a633 | 535 | struct tty_struct *tty = devpts_get_tty(pts_inode, idx); |
99f1fe18 AC |
536 | /* Master must be open before slave */ |
537 | if (!tty) | |
538 | return ERR_PTR(-EIO); | |
539 | return tty; | |
540 | } | |
541 | ||
bf970ee4 | 542 | static void pty_unix98_shutdown(struct tty_struct *tty) |
feebed65 AC |
543 | { |
544 | /* We have our own method as we don't use the tty index */ | |
545 | kfree(tty->termios); | |
feebed65 AC |
546 | } |
547 | ||
8b0a88d5 AC |
548 | /* We have no need to install and remove our tty objects as devpts does all |
549 | the work for us */ | |
550 | ||
bf970ee4 | 551 | static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 | 552 | { |
bf970ee4 AC |
553 | struct tty_struct *o_tty; |
554 | int idx = tty->index; | |
555 | ||
556 | o_tty = alloc_tty_struct(); | |
557 | if (!o_tty) | |
558 | return -ENOMEM; | |
559 | if (!try_module_get(driver->other->owner)) { | |
560 | /* This cannot in fact currently happen */ | |
561 | free_tty_struct(o_tty); | |
562 | return -ENOMEM; | |
563 | } | |
564 | initialize_tty_struct(o_tty, driver->other, idx); | |
565 | ||
8dff04ea | 566 | tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL); |
bf970ee4 AC |
567 | if (tty->termios == NULL) |
568 | goto free_mem_out; | |
569 | *tty->termios = driver->init_termios; | |
8dff04ea AC |
570 | tty->termios_locked = tty->termios + 1; |
571 | ||
572 | o_tty->termios = kzalloc(sizeof(struct ktermios[2]), GFP_KERNEL); | |
bf970ee4 AC |
573 | if (o_tty->termios == NULL) |
574 | goto free_mem_out; | |
575 | *o_tty->termios = driver->other->init_termios; | |
8dff04ea | 576 | o_tty->termios_locked = o_tty->termios + 1; |
bf970ee4 AC |
577 | |
578 | tty_driver_kref_get(driver->other); | |
579 | if (driver->subtype == PTY_TYPE_MASTER) | |
580 | o_tty->count++; | |
581 | /* Establish the links in both directions */ | |
582 | tty->link = o_tty; | |
583 | o_tty->link = tty; | |
584 | /* | |
585 | * All structures have been allocated, so now we install them. | |
586 | * Failures after this point use release_tty to clean up, so | |
587 | * there's no need to null out the local pointers. | |
588 | */ | |
589 | tty_driver_kref_get(driver); | |
590 | tty->count++; | |
591 | pty_count++; | |
8b0a88d5 | 592 | return 0; |
bf970ee4 | 593 | free_mem_out: |
8dff04ea | 594 | kfree(o_tty->termios); |
bf970ee4 AC |
595 | module_put(o_tty->driver->owner); |
596 | free_tty_struct(o_tty); | |
8dff04ea | 597 | kfree(tty->termios); |
bf970ee4 | 598 | return -ENOMEM; |
8b0a88d5 AC |
599 | } |
600 | ||
bf970ee4 | 601 | static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 | 602 | { |
bf970ee4 | 603 | pty_count--; |
8b0a88d5 AC |
604 | } |
605 | ||
feebed65 | 606 | static const struct tty_operations ptm_unix98_ops = { |
99f1fe18 | 607 | .lookup = ptm_unix98_lookup, |
bf970ee4 AC |
608 | .install = pty_unix98_install, |
609 | .remove = pty_unix98_remove, | |
3e8e88ca AC |
610 | .open = pty_open, |
611 | .close = pty_close, | |
612 | .write = pty_write, | |
613 | .write_room = pty_write_room, | |
614 | .flush_buffer = pty_flush_buffer, | |
615 | .chars_in_buffer = pty_chars_in_buffer, | |
616 | .unthrottle = pty_unthrottle, | |
617 | .set_termios = pty_set_termios, | |
feebed65 | 618 | .ioctl = pty_unix98_ioctl, |
fc6f6238 AC |
619 | .shutdown = pty_unix98_shutdown, |
620 | .resize = pty_resize | |
3e8e88ca AC |
621 | }; |
622 | ||
99f1fe18 AC |
623 | static const struct tty_operations pty_unix98_ops = { |
624 | .lookup = pts_unix98_lookup, | |
bf970ee4 AC |
625 | .install = pty_unix98_install, |
626 | .remove = pty_unix98_remove, | |
99f1fe18 AC |
627 | .open = pty_open, |
628 | .close = pty_close, | |
629 | .write = pty_write, | |
630 | .write_room = pty_write_room, | |
631 | .flush_buffer = pty_flush_buffer, | |
632 | .chars_in_buffer = pty_chars_in_buffer, | |
633 | .unthrottle = pty_unthrottle, | |
634 | .set_termios = pty_set_termios, | |
bf970ee4 | 635 | .shutdown = pty_unix98_shutdown |
99f1fe18 | 636 | }; |
d81ed103 AC |
637 | |
638 | /** | |
639 | * ptmx_open - open a unix 98 pty master | |
640 | * @inode: inode of device file | |
641 | * @filp: file pointer to tty | |
642 | * | |
643 | * Allocate a unix98 pty master device from the ptmx driver. | |
644 | * | |
645 | * Locking: tty_mutex protects the init_dev work. tty->count should | |
646 | * protect the rest. | |
647 | * allocated_ptys_lock handles the list of free pty numbers | |
648 | */ | |
649 | ||
64ba3dc3 | 650 | static int ptmx_open(struct inode *inode, struct file *filp) |
d81ed103 AC |
651 | { |
652 | struct tty_struct *tty; | |
653 | int retval; | |
654 | int index; | |
655 | ||
656 | nonseekable_open(inode, filp); | |
657 | ||
658 | /* find a device that is not in use. */ | |
64ba3dc3 | 659 | tty_lock(); |
15f1a633 | 660 | index = devpts_new_index(inode); |
64ba3dc3 | 661 | tty_unlock(); |
d81ed103 AC |
662 | if (index < 0) |
663 | return index; | |
664 | ||
665 | mutex_lock(&tty_mutex); | |
64ba3dc3 | 666 | tty_lock(); |
73ec06fc | 667 | tty = tty_init_dev(ptm_driver, index, 1); |
d81ed103 AC |
668 | mutex_unlock(&tty_mutex); |
669 | ||
73ec06fc AC |
670 | if (IS_ERR(tty)) { |
671 | retval = PTR_ERR(tty); | |
d81ed103 | 672 | goto out; |
73ec06fc | 673 | } |
d81ed103 AC |
674 | |
675 | set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ | |
676 | filp->private_data = tty; | |
677 | file_move(filp, &tty->tty_files); | |
678 | ||
15f1a633 | 679 | retval = devpts_pty_new(inode, tty->link); |
d81ed103 AC |
680 | if (retval) |
681 | goto out1; | |
682 | ||
683 | retval = ptm_driver->ops->open(tty, filp); | |
64ba3dc3 AB |
684 | if (retval) |
685 | goto out2; | |
d81ed103 | 686 | out1: |
64ba3dc3 AB |
687 | tty_unlock(); |
688 | return retval; | |
689 | out2: | |
690 | tty_unlock(); | |
eeb89d91 | 691 | tty_release(inode, filp); |
d81ed103 AC |
692 | return retval; |
693 | out: | |
15f1a633 | 694 | devpts_kill_index(inode, index); |
ec79d605 | 695 | tty_unlock(); |
64ba3dc3 | 696 | return retval; |
d81ed103 AC |
697 | } |
698 | ||
699 | static struct file_operations ptmx_fops; | |
700 | ||
1da177e4 LT |
701 | static void __init unix98_pty_init(void) |
702 | { | |
1da177e4 LT |
703 | ptm_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX); |
704 | if (!ptm_driver) | |
705 | panic("Couldn't allocate Unix98 ptm driver"); | |
706 | pts_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX); | |
707 | if (!pts_driver) | |
708 | panic("Couldn't allocate Unix98 pts driver"); | |
709 | ||
710 | ptm_driver->owner = THIS_MODULE; | |
711 | ptm_driver->driver_name = "pty_master"; | |
712 | ptm_driver->name = "ptm"; | |
713 | ptm_driver->major = UNIX98_PTY_MASTER_MAJOR; | |
714 | ptm_driver->minor_start = 0; | |
715 | ptm_driver->type = TTY_DRIVER_TYPE_PTY; | |
716 | ptm_driver->subtype = PTY_TYPE_MASTER; | |
717 | ptm_driver->init_termios = tty_std_termios; | |
718 | ptm_driver->init_termios.c_iflag = 0; | |
719 | ptm_driver->init_termios.c_oflag = 0; | |
720 | ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
721 | ptm_driver->init_termios.c_lflag = 0; | |
606d099c AC |
722 | ptm_driver->init_termios.c_ispeed = 38400; |
723 | ptm_driver->init_termios.c_ospeed = 38400; | |
1da177e4 | 724 | ptm_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | |
331b8319 | 725 | TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM; |
1da177e4 | 726 | ptm_driver->other = pts_driver; |
feebed65 | 727 | tty_set_operations(ptm_driver, &ptm_unix98_ops); |
1da177e4 LT |
728 | |
729 | pts_driver->owner = THIS_MODULE; | |
730 | pts_driver->driver_name = "pty_slave"; | |
731 | pts_driver->name = "pts"; | |
732 | pts_driver->major = UNIX98_PTY_SLAVE_MAJOR; | |
733 | pts_driver->minor_start = 0; | |
734 | pts_driver->type = TTY_DRIVER_TYPE_PTY; | |
735 | pts_driver->subtype = PTY_TYPE_SLAVE; | |
736 | pts_driver->init_termios = tty_std_termios; | |
737 | pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
606d099c AC |
738 | pts_driver->init_termios.c_ispeed = 38400; |
739 | pts_driver->init_termios.c_ospeed = 38400; | |
1da177e4 | 740 | pts_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | |
331b8319 | 741 | TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM; |
1da177e4 | 742 | pts_driver->other = ptm_driver; |
99f1fe18 | 743 | tty_set_operations(pts_driver, &pty_unix98_ops); |
fe9cd962 | 744 | |
1da177e4 LT |
745 | if (tty_register_driver(ptm_driver)) |
746 | panic("Couldn't register Unix98 ptm driver"); | |
747 | if (tty_register_driver(pts_driver)) | |
748 | panic("Couldn't register Unix98 pts driver"); | |
749 | ||
fe9cd962 | 750 | register_sysctl_table(pty_root_table); |
d81ed103 AC |
751 | |
752 | /* Now create the /dev/ptmx special device */ | |
753 | tty_default_fops(&ptmx_fops); | |
754 | ptmx_fops.open = ptmx_open; | |
755 | ||
756 | cdev_init(&ptmx_cdev, &ptmx_fops); | |
757 | if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) || | |
758 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0) | |
759 | panic("Couldn't register /dev/ptmx driver\n"); | |
760 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx"); | |
1da177e4 | 761 | } |
d81ed103 | 762 | |
1da177e4 LT |
763 | #else |
764 | static inline void unix98_pty_init(void) { } | |
765 | #endif | |
766 | ||
767 | static int __init pty_init(void) | |
768 | { | |
769 | legacy_pty_init(); | |
770 | unix98_pty_init(); | |
771 | return 0; | |
772 | } | |
773 | module_init(pty_init); |