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 | |
8 | * Added TTY_DO_WRITE_WAKEUP to enable n_tty to send POLL_OUT to | |
9 | * waiting writers -- Sapan Bhatia <sapan@corewars.org> | |
10 | * | |
fe9cd962 AC |
11 | * When reading this code see also fs/devpts. In particular note that the |
12 | * driver_data field is used by the devpts side as a binding to the devpts | |
13 | * inode. | |
1da177e4 LT |
14 | */ |
15 | ||
fe9cd962 | 16 | #include <linux/module.h> |
1da177e4 LT |
17 | |
18 | #include <linux/errno.h> | |
1da177e4 LT |
19 | #include <linux/interrupt.h> |
20 | #include <linux/tty.h> | |
21 | #include <linux/tty_flip.h> | |
22 | #include <linux/fcntl.h> | |
23 | #include <linux/string.h> | |
24 | #include <linux/major.h> | |
25 | #include <linux/mm.h> | |
26 | #include <linux/init.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> | |
32 | ||
fe9cd962 AC |
33 | #include <asm/system.h> |
34 | ||
1da177e4 LT |
35 | /* These are global because they are accessed in tty_io.c */ |
36 | #ifdef CONFIG_UNIX98_PTYS | |
37 | struct tty_driver *ptm_driver; | |
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 LT |
80 | { |
81 | struct tty_struct *o_tty = tty->link; | |
82 | ||
83 | if (!o_tty) | |
84 | return; | |
85 | ||
86 | tty_wakeup(o_tty); | |
87 | set_bit(TTY_THROTTLED, &tty->flags); | |
88 | } | |
89 | ||
90 | /* | |
fe9cd962 | 91 | * WSH 05/24/97: modified to |
1da177e4 LT |
92 | * (1) use space in tty->flip instead of a shared temp buffer |
93 | * The flip buffers aren't being used for a pty, so there's lots | |
94 | * of space available. The buffer is protected by a per-pty | |
95 | * semaphore that should almost never come under contention. | |
96 | * (2) avoid redundant copying for cases where count >> receive_room | |
97 | * N.B. Calls from user space may now return an error code instead of | |
98 | * a count. | |
99 | * | |
100 | * FIXME: Our pty_write method is called with our ldisc lock held but | |
101 | * not our partners. We can't just take the other one blindly without | |
817d6d3b | 102 | * risking deadlocks. |
1da177e4 | 103 | */ |
fe9cd962 AC |
104 | static int pty_write(struct tty_struct *tty, const unsigned char *buf, |
105 | int count) | |
1da177e4 LT |
106 | { |
107 | struct tty_struct *to = tty->link; | |
108 | int c; | |
109 | ||
110 | if (!to || tty->stopped) | |
111 | return 0; | |
112 | ||
33f0f88f | 113 | c = to->receive_room; |
1da177e4 LT |
114 | if (c > count) |
115 | c = count; | |
a352def2 | 116 | to->ldisc.ops->receive_buf(to, buf, NULL, c); |
fe9cd962 | 117 | |
1da177e4 LT |
118 | return c; |
119 | } | |
120 | ||
121 | static int pty_write_room(struct tty_struct *tty) | |
122 | { | |
123 | struct tty_struct *to = tty->link; | |
124 | ||
125 | if (!to || tty->stopped) | |
126 | return 0; | |
127 | ||
33f0f88f | 128 | return to->receive_room; |
1da177e4 LT |
129 | } |
130 | ||
131 | /* | |
132 | * WSH 05/24/97: Modified for asymmetric MASTER/SLAVE behavior | |
fe9cd962 | 133 | * The chars_in_buffer() value is used by the ldisc select() function |
1da177e4 LT |
134 | * to hold off writing when chars_in_buffer > WAKEUP_CHARS (== 256). |
135 | * The pty driver chars_in_buffer() Master/Slave must behave differently: | |
136 | * | |
137 | * The Master side needs to allow typed-ahead commands to accumulate | |
138 | * while being canonicalized, so we report "our buffer" as empty until | |
139 | * some threshold is reached, and then report the count. (Any count > | |
fe9cd962 AC |
140 | * WAKEUP_CHARS is regarded by select() as "full".) To avoid deadlock |
141 | * the count returned must be 0 if no canonical data is available to be | |
1da177e4 | 142 | * read. (The N_TTY ldisc.chars_in_buffer now knows this.) |
fe9cd962 | 143 | * |
1da177e4 LT |
144 | * The Slave side passes all characters in raw mode to the Master side's |
145 | * buffer where they can be read immediately, so in this case we can | |
146 | * return the true count in the buffer. | |
147 | */ | |
148 | static int pty_chars_in_buffer(struct tty_struct *tty) | |
149 | { | |
150 | struct tty_struct *to = tty->link; | |
1da177e4 LT |
151 | int count; |
152 | ||
153 | /* We should get the line discipline lock for "tty->link" */ | |
a352def2 | 154 | if (!to || !to->ldisc.ops->chars_in_buffer) |
1da177e4 LT |
155 | return 0; |
156 | ||
157 | /* The ldisc must report 0 if no characters available to be read */ | |
a352def2 | 158 | count = to->ldisc.ops->chars_in_buffer(to); |
1da177e4 | 159 | |
fe9cd962 AC |
160 | if (tty->driver->subtype == PTY_TYPE_SLAVE) |
161 | return count; | |
1da177e4 | 162 | |
fe9cd962 | 163 | /* Master side driver ... if the other side's read buffer is less than |
1da177e4 | 164 | * half full, return 0 to allow writers to proceed; otherwise return |
fe9cd962 | 165 | * the count. This leaves a comfortable margin to avoid overflow, |
1da177e4 LT |
166 | * and still allows half a buffer's worth of typed-ahead commands. |
167 | */ | |
fe9cd962 | 168 | return (count < N_TTY_BUF_SIZE/2) ? 0 : count; |
1da177e4 LT |
169 | } |
170 | ||
171 | /* Set the lock flag on a pty */ | |
fe9cd962 | 172 | static int pty_set_lock(struct tty_struct *tty, int __user *arg) |
1da177e4 LT |
173 | { |
174 | int val; | |
fe9cd962 | 175 | if (get_user(val, arg)) |
1da177e4 LT |
176 | return -EFAULT; |
177 | if (val) | |
178 | set_bit(TTY_PTY_LOCK, &tty->flags); | |
179 | else | |
180 | clear_bit(TTY_PTY_LOCK, &tty->flags); | |
181 | return 0; | |
182 | } | |
183 | ||
184 | static void pty_flush_buffer(struct tty_struct *tty) | |
185 | { | |
186 | struct tty_struct *to = tty->link; | |
04f378b1 | 187 | unsigned long flags; |
fe9cd962 | 188 | |
1da177e4 LT |
189 | if (!to) |
190 | return; | |
fe9cd962 | 191 | |
a352def2 AC |
192 | if (to->ldisc.ops->flush_buffer) |
193 | to->ldisc.ops->flush_buffer(to); | |
fe9cd962 | 194 | |
1da177e4 | 195 | if (to->packet) { |
04f378b1 | 196 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
1da177e4 LT |
197 | tty->ctrl_status |= TIOCPKT_FLUSHWRITE; |
198 | wake_up_interruptible(&to->read_wait); | |
04f378b1 | 199 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
1da177e4 LT |
200 | } |
201 | } | |
202 | ||
fe9cd962 | 203 | static int pty_open(struct tty_struct *tty, struct file *filp) |
1da177e4 LT |
204 | { |
205 | int retval = -ENODEV; | |
206 | ||
207 | if (!tty || !tty->link) | |
208 | goto out; | |
209 | ||
210 | retval = -EIO; | |
211 | if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) | |
212 | goto out; | |
213 | if (test_bit(TTY_PTY_LOCK, &tty->link->flags)) | |
214 | goto out; | |
215 | if (tty->link->count != 1) | |
216 | goto out; | |
217 | ||
218 | clear_bit(TTY_OTHER_CLOSED, &tty->link->flags); | |
219 | set_bit(TTY_THROTTLED, &tty->flags); | |
220 | set_bit(TTY_DO_WRITE_WAKEUP, &tty->flags); | |
221 | retval = 0; | |
222 | out: | |
223 | return retval; | |
224 | } | |
225 | ||
fe9cd962 AC |
226 | static void pty_set_termios(struct tty_struct *tty, |
227 | struct ktermios *old_termios) | |
1da177e4 | 228 | { |
fe9cd962 AC |
229 | tty->termios->c_cflag &= ~(CSIZE | PARENB); |
230 | tty->termios->c_cflag |= (CS8 | CREAD); | |
1da177e4 LT |
231 | } |
232 | ||
bf970ee4 AC |
233 | static int pty_install(struct tty_driver *driver, struct tty_struct *tty) |
234 | { | |
235 | struct tty_struct *o_tty; | |
236 | int idx = tty->index; | |
237 | int retval; | |
238 | ||
239 | o_tty = alloc_tty_struct(); | |
240 | if (!o_tty) | |
241 | return -ENOMEM; | |
242 | if (!try_module_get(driver->other->owner)) { | |
243 | /* This cannot in fact currently happen */ | |
244 | free_tty_struct(o_tty); | |
245 | return -ENOMEM; | |
246 | } | |
247 | initialize_tty_struct(o_tty, driver->other, idx); | |
248 | ||
249 | /* We always use new tty termios data so we can do this | |
250 | the easy way .. */ | |
251 | retval = tty_init_termios(tty); | |
252 | if (retval) | |
253 | goto free_mem_out; | |
254 | ||
255 | retval = tty_init_termios(o_tty); | |
256 | if (retval) { | |
257 | tty_free_termios(tty); | |
258 | goto free_mem_out; | |
259 | } | |
fe9cd962 | 260 | |
bf970ee4 AC |
261 | /* |
262 | * Everything allocated ... set up the o_tty structure. | |
263 | */ | |
264 | driver->other->ttys[idx] = o_tty; | |
265 | tty_driver_kref_get(driver->other); | |
266 | if (driver->subtype == PTY_TYPE_MASTER) | |
267 | o_tty->count++; | |
268 | /* Establish the links in both directions */ | |
269 | tty->link = o_tty; | |
270 | o_tty->link = tty; | |
271 | ||
272 | tty_driver_kref_get(driver); | |
273 | tty->count++; | |
274 | driver->ttys[idx] = tty; | |
275 | return 0; | |
276 | free_mem_out: | |
277 | module_put(o_tty->driver->owner); | |
278 | free_tty_struct(o_tty); | |
279 | return -ENOMEM; | |
280 | } | |
281 | ||
282 | ||
b68e31d0 | 283 | static const struct tty_operations pty_ops = { |
bf970ee4 | 284 | .install = pty_install, |
1da177e4 LT |
285 | .open = pty_open, |
286 | .close = pty_close, | |
287 | .write = pty_write, | |
288 | .write_room = pty_write_room, | |
289 | .flush_buffer = pty_flush_buffer, | |
290 | .chars_in_buffer = pty_chars_in_buffer, | |
291 | .unthrottle = pty_unthrottle, | |
292 | .set_termios = pty_set_termios, | |
293 | }; | |
294 | ||
295 | /* Traditional BSD devices */ | |
296 | #ifdef CONFIG_LEGACY_PTYS | |
297 | static struct tty_driver *pty_driver, *pty_slave_driver; | |
298 | ||
299 | static int pty_bsd_ioctl(struct tty_struct *tty, struct file *file, | |
300 | unsigned int cmd, unsigned long arg) | |
301 | { | |
302 | switch (cmd) { | |
303 | case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */ | |
304 | return pty_set_lock(tty, (int __user *) arg); | |
305 | } | |
306 | return -ENOIOCTLCMD; | |
307 | } | |
308 | ||
dc8c8587 KS |
309 | static int legacy_count = CONFIG_LEGACY_PTY_COUNT; |
310 | module_param(legacy_count, int, 0); | |
311 | ||
3e8e88ca AC |
312 | static const struct tty_operations pty_ops_bsd = { |
313 | .open = pty_open, | |
314 | .close = pty_close, | |
315 | .write = pty_write, | |
316 | .write_room = pty_write_room, | |
317 | .flush_buffer = pty_flush_buffer, | |
318 | .chars_in_buffer = pty_chars_in_buffer, | |
319 | .unthrottle = pty_unthrottle, | |
320 | .set_termios = pty_set_termios, | |
321 | .ioctl = pty_bsd_ioctl, | |
322 | }; | |
323 | ||
1da177e4 LT |
324 | static void __init legacy_pty_init(void) |
325 | { | |
dc8c8587 KS |
326 | if (legacy_count <= 0) |
327 | return; | |
1da177e4 | 328 | |
dc8c8587 | 329 | pty_driver = alloc_tty_driver(legacy_count); |
1da177e4 LT |
330 | if (!pty_driver) |
331 | panic("Couldn't allocate pty driver"); | |
332 | ||
dc8c8587 | 333 | pty_slave_driver = alloc_tty_driver(legacy_count); |
1da177e4 LT |
334 | if (!pty_slave_driver) |
335 | panic("Couldn't allocate pty slave driver"); | |
336 | ||
337 | pty_driver->owner = THIS_MODULE; | |
338 | pty_driver->driver_name = "pty_master"; | |
339 | pty_driver->name = "pty"; | |
1da177e4 LT |
340 | pty_driver->major = PTY_MASTER_MAJOR; |
341 | pty_driver->minor_start = 0; | |
342 | pty_driver->type = TTY_DRIVER_TYPE_PTY; | |
343 | pty_driver->subtype = PTY_TYPE_MASTER; | |
344 | pty_driver->init_termios = tty_std_termios; | |
345 | pty_driver->init_termios.c_iflag = 0; | |
346 | pty_driver->init_termios.c_oflag = 0; | |
347 | pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
348 | pty_driver->init_termios.c_lflag = 0; | |
606d099c AC |
349 | pty_driver->init_termios.c_ispeed = 38400; |
350 | pty_driver->init_termios.c_ospeed = 38400; | |
1da177e4 LT |
351 | pty_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW; |
352 | pty_driver->other = pty_slave_driver; | |
353 | tty_set_operations(pty_driver, &pty_ops); | |
1da177e4 LT |
354 | |
355 | pty_slave_driver->owner = THIS_MODULE; | |
356 | pty_slave_driver->driver_name = "pty_slave"; | |
357 | pty_slave_driver->name = "ttyp"; | |
1da177e4 LT |
358 | pty_slave_driver->major = PTY_SLAVE_MAJOR; |
359 | pty_slave_driver->minor_start = 0; | |
360 | pty_slave_driver->type = TTY_DRIVER_TYPE_PTY; | |
361 | pty_slave_driver->subtype = PTY_TYPE_SLAVE; | |
362 | pty_slave_driver->init_termios = tty_std_termios; | |
363 | pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
606d099c AC |
364 | pty_slave_driver->init_termios.c_ispeed = 38400; |
365 | pty_slave_driver->init_termios.c_ospeed = 38400; | |
1da177e4 LT |
366 | pty_slave_driver->flags = TTY_DRIVER_RESET_TERMIOS | |
367 | TTY_DRIVER_REAL_RAW; | |
368 | pty_slave_driver->other = pty_driver; | |
369 | tty_set_operations(pty_slave_driver, &pty_ops); | |
370 | ||
371 | if (tty_register_driver(pty_driver)) | |
372 | panic("Couldn't register pty driver"); | |
373 | if (tty_register_driver(pty_slave_driver)) | |
374 | panic("Couldn't register pty slave driver"); | |
375 | } | |
376 | #else | |
377 | static inline void legacy_pty_init(void) { } | |
378 | #endif | |
379 | ||
380 | /* Unix98 devices */ | |
381 | #ifdef CONFIG_UNIX98_PTYS | |
382 | /* | |
383 | * sysctl support for setting limits on the number of Unix98 ptys allocated. | |
384 | * Otherwise one can eat up all kernel memory by opening /dev/ptmx repeatedly. | |
385 | */ | |
386 | int pty_limit = NR_UNIX98_PTY_DEFAULT; | |
fe9cd962 | 387 | static int pty_limit_min; |
1da177e4 | 388 | static int pty_limit_max = NR_UNIX98_PTY_MAX; |
fe9cd962 | 389 | static int pty_count; |
1da177e4 | 390 | |
d81ed103 AC |
391 | static struct cdev ptmx_cdev; |
392 | ||
35834ca1 | 393 | static struct ctl_table pty_table[] = { |
1da177e4 LT |
394 | { |
395 | .ctl_name = PTY_MAX, | |
396 | .procname = "max", | |
397 | .maxlen = sizeof(int), | |
398 | .mode = 0644, | |
399 | .data = &pty_limit, | |
400 | .proc_handler = &proc_dointvec_minmax, | |
401 | .strategy = &sysctl_intvec, | |
402 | .extra1 = &pty_limit_min, | |
403 | .extra2 = &pty_limit_max, | |
404 | }, { | |
405 | .ctl_name = PTY_NR, | |
406 | .procname = "nr", | |
407 | .maxlen = sizeof(int), | |
408 | .mode = 0444, | |
bf970ee4 | 409 | .data = &pty_count, |
1da177e4 LT |
410 | .proc_handler = &proc_dointvec, |
411 | }, { | |
412 | .ctl_name = 0 | |
413 | } | |
414 | }; | |
415 | ||
35834ca1 EB |
416 | static struct ctl_table pty_kern_table[] = { |
417 | { | |
418 | .ctl_name = KERN_PTY, | |
419 | .procname = "pty", | |
420 | .mode = 0555, | |
421 | .child = pty_table, | |
422 | }, | |
423 | {} | |
424 | }; | |
425 | ||
426 | static struct ctl_table pty_root_table[] = { | |
427 | { | |
428 | .ctl_name = CTL_KERN, | |
429 | .procname = "kernel", | |
430 | .mode = 0555, | |
431 | .child = pty_kern_table, | |
432 | }, | |
433 | {} | |
434 | }; | |
435 | ||
436 | ||
1da177e4 LT |
437 | static int pty_unix98_ioctl(struct tty_struct *tty, struct file *file, |
438 | unsigned int cmd, unsigned long arg) | |
439 | { | |
440 | switch (cmd) { | |
441 | case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */ | |
442 | return pty_set_lock(tty, (int __user *)arg); | |
443 | case TIOCGPTN: /* Get PT Number */ | |
444 | return put_user(tty->index, (unsigned int __user *)arg); | |
445 | } | |
446 | ||
447 | return -ENOIOCTLCMD; | |
448 | } | |
449 | ||
99f1fe18 AC |
450 | /** |
451 | * ptm_unix98_lookup - find a pty master | |
452 | * @driver: ptm driver | |
453 | * @idx: tty index | |
454 | * | |
455 | * Look up a pty master device. Called under the tty_mutex for now. | |
456 | * This provides our locking. | |
457 | */ | |
458 | ||
15f1a633 SB |
459 | static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver, |
460 | struct inode *ptm_inode, int idx) | |
99f1fe18 | 461 | { |
15f1a633 | 462 | struct tty_struct *tty = devpts_get_tty(ptm_inode, idx); |
99f1fe18 AC |
463 | if (tty) |
464 | tty = tty->link; | |
465 | return tty; | |
466 | } | |
467 | ||
468 | /** | |
469 | * pts_unix98_lookup - find a pty slave | |
470 | * @driver: pts driver | |
471 | * @idx: tty index | |
472 | * | |
473 | * Look up a pty master device. Called under the tty_mutex for now. | |
474 | * This provides our locking. | |
475 | */ | |
476 | ||
15f1a633 SB |
477 | static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver, |
478 | struct inode *pts_inode, int idx) | |
99f1fe18 | 479 | { |
15f1a633 | 480 | struct tty_struct *tty = devpts_get_tty(pts_inode, idx); |
99f1fe18 AC |
481 | /* Master must be open before slave */ |
482 | if (!tty) | |
483 | return ERR_PTR(-EIO); | |
484 | return tty; | |
485 | } | |
486 | ||
bf970ee4 | 487 | static void pty_unix98_shutdown(struct tty_struct *tty) |
feebed65 AC |
488 | { |
489 | /* We have our own method as we don't use the tty index */ | |
490 | kfree(tty->termios); | |
491 | kfree(tty->termios_locked); | |
492 | } | |
493 | ||
8b0a88d5 AC |
494 | /* We have no need to install and remove our tty objects as devpts does all |
495 | the work for us */ | |
496 | ||
bf970ee4 | 497 | static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 | 498 | { |
bf970ee4 AC |
499 | struct tty_struct *o_tty; |
500 | int idx = tty->index; | |
501 | ||
502 | o_tty = alloc_tty_struct(); | |
503 | if (!o_tty) | |
504 | return -ENOMEM; | |
505 | if (!try_module_get(driver->other->owner)) { | |
506 | /* This cannot in fact currently happen */ | |
507 | free_tty_struct(o_tty); | |
508 | return -ENOMEM; | |
509 | } | |
510 | initialize_tty_struct(o_tty, driver->other, idx); | |
511 | ||
512 | tty->termios = kmalloc(sizeof(struct ktermios), GFP_KERNEL); | |
513 | if (tty->termios == NULL) | |
514 | goto free_mem_out; | |
515 | *tty->termios = driver->init_termios; | |
516 | tty->termios_locked = kzalloc(sizeof(struct ktermios), GFP_KERNEL); | |
517 | if (tty->termios_locked == NULL) | |
518 | goto free_mem_out; | |
519 | o_tty->termios = kmalloc(sizeof(struct ktermios), GFP_KERNEL); | |
520 | if (o_tty->termios == NULL) | |
521 | goto free_mem_out; | |
522 | *o_tty->termios = driver->other->init_termios; | |
523 | o_tty->termios_locked = kzalloc(sizeof(struct ktermios), GFP_KERNEL); | |
524 | if (o_tty->termios_locked == NULL) | |
525 | goto free_mem_out; | |
526 | ||
527 | tty_driver_kref_get(driver->other); | |
528 | if (driver->subtype == PTY_TYPE_MASTER) | |
529 | o_tty->count++; | |
530 | /* Establish the links in both directions */ | |
531 | tty->link = o_tty; | |
532 | o_tty->link = tty; | |
533 | /* | |
534 | * All structures have been allocated, so now we install them. | |
535 | * Failures after this point use release_tty to clean up, so | |
536 | * there's no need to null out the local pointers. | |
537 | */ | |
538 | tty_driver_kref_get(driver); | |
539 | tty->count++; | |
540 | pty_count++; | |
8b0a88d5 | 541 | return 0; |
bf970ee4 | 542 | free_mem_out: |
fe9cd962 | 543 | pty_unix98_shutdown(o_tty); |
bf970ee4 AC |
544 | module_put(o_tty->driver->owner); |
545 | free_tty_struct(o_tty); | |
fe9cd962 | 546 | pty_unix98_shutdown(tty); |
bf970ee4 | 547 | return -ENOMEM; |
8b0a88d5 AC |
548 | } |
549 | ||
bf970ee4 | 550 | static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 | 551 | { |
bf970ee4 | 552 | pty_count--; |
8b0a88d5 AC |
553 | } |
554 | ||
feebed65 | 555 | static const struct tty_operations ptm_unix98_ops = { |
99f1fe18 | 556 | .lookup = ptm_unix98_lookup, |
bf970ee4 AC |
557 | .install = pty_unix98_install, |
558 | .remove = pty_unix98_remove, | |
3e8e88ca AC |
559 | .open = pty_open, |
560 | .close = pty_close, | |
561 | .write = pty_write, | |
562 | .write_room = pty_write_room, | |
563 | .flush_buffer = pty_flush_buffer, | |
564 | .chars_in_buffer = pty_chars_in_buffer, | |
565 | .unthrottle = pty_unthrottle, | |
566 | .set_termios = pty_set_termios, | |
feebed65 | 567 | .ioctl = pty_unix98_ioctl, |
bf970ee4 | 568 | .shutdown = pty_unix98_shutdown |
3e8e88ca AC |
569 | }; |
570 | ||
99f1fe18 AC |
571 | static const struct tty_operations pty_unix98_ops = { |
572 | .lookup = pts_unix98_lookup, | |
bf970ee4 AC |
573 | .install = pty_unix98_install, |
574 | .remove = pty_unix98_remove, | |
99f1fe18 AC |
575 | .open = pty_open, |
576 | .close = pty_close, | |
577 | .write = pty_write, | |
578 | .write_room = pty_write_room, | |
579 | .flush_buffer = pty_flush_buffer, | |
580 | .chars_in_buffer = pty_chars_in_buffer, | |
581 | .unthrottle = pty_unthrottle, | |
582 | .set_termios = pty_set_termios, | |
bf970ee4 | 583 | .shutdown = pty_unix98_shutdown |
99f1fe18 | 584 | }; |
d81ed103 AC |
585 | |
586 | /** | |
587 | * ptmx_open - open a unix 98 pty master | |
588 | * @inode: inode of device file | |
589 | * @filp: file pointer to tty | |
590 | * | |
591 | * Allocate a unix98 pty master device from the ptmx driver. | |
592 | * | |
593 | * Locking: tty_mutex protects the init_dev work. tty->count should | |
594 | * protect the rest. | |
595 | * allocated_ptys_lock handles the list of free pty numbers | |
596 | */ | |
597 | ||
598 | static int __ptmx_open(struct inode *inode, struct file *filp) | |
599 | { | |
600 | struct tty_struct *tty; | |
601 | int retval; | |
602 | int index; | |
603 | ||
604 | nonseekable_open(inode, filp); | |
605 | ||
606 | /* find a device that is not in use. */ | |
15f1a633 | 607 | index = devpts_new_index(inode); |
d81ed103 AC |
608 | if (index < 0) |
609 | return index; | |
610 | ||
611 | mutex_lock(&tty_mutex); | |
73ec06fc | 612 | tty = tty_init_dev(ptm_driver, index, 1); |
d81ed103 AC |
613 | mutex_unlock(&tty_mutex); |
614 | ||
73ec06fc AC |
615 | if (IS_ERR(tty)) { |
616 | retval = PTR_ERR(tty); | |
d81ed103 | 617 | goto out; |
73ec06fc | 618 | } |
d81ed103 AC |
619 | |
620 | set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ | |
621 | filp->private_data = tty; | |
622 | file_move(filp, &tty->tty_files); | |
623 | ||
15f1a633 | 624 | retval = devpts_pty_new(inode, tty->link); |
d81ed103 AC |
625 | if (retval) |
626 | goto out1; | |
627 | ||
628 | retval = ptm_driver->ops->open(tty, filp); | |
629 | if (!retval) | |
630 | return 0; | |
631 | out1: | |
632 | tty_release_dev(filp); | |
633 | return retval; | |
634 | out: | |
15f1a633 | 635 | devpts_kill_index(inode, index); |
d81ed103 AC |
636 | return retval; |
637 | } | |
638 | ||
639 | static int ptmx_open(struct inode *inode, struct file *filp) | |
640 | { | |
641 | int ret; | |
642 | ||
643 | lock_kernel(); | |
644 | ret = __ptmx_open(inode, filp); | |
645 | unlock_kernel(); | |
646 | return ret; | |
647 | } | |
648 | ||
649 | static struct file_operations ptmx_fops; | |
650 | ||
1da177e4 LT |
651 | static void __init unix98_pty_init(void) |
652 | { | |
1da177e4 LT |
653 | ptm_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX); |
654 | if (!ptm_driver) | |
655 | panic("Couldn't allocate Unix98 ptm driver"); | |
656 | pts_driver = alloc_tty_driver(NR_UNIX98_PTY_MAX); | |
657 | if (!pts_driver) | |
658 | panic("Couldn't allocate Unix98 pts driver"); | |
659 | ||
660 | ptm_driver->owner = THIS_MODULE; | |
661 | ptm_driver->driver_name = "pty_master"; | |
662 | ptm_driver->name = "ptm"; | |
663 | ptm_driver->major = UNIX98_PTY_MASTER_MAJOR; | |
664 | ptm_driver->minor_start = 0; | |
665 | ptm_driver->type = TTY_DRIVER_TYPE_PTY; | |
666 | ptm_driver->subtype = PTY_TYPE_MASTER; | |
667 | ptm_driver->init_termios = tty_std_termios; | |
668 | ptm_driver->init_termios.c_iflag = 0; | |
669 | ptm_driver->init_termios.c_oflag = 0; | |
670 | ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
671 | ptm_driver->init_termios.c_lflag = 0; | |
606d099c AC |
672 | ptm_driver->init_termios.c_ispeed = 38400; |
673 | ptm_driver->init_termios.c_ospeed = 38400; | |
1da177e4 | 674 | ptm_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | |
331b8319 | 675 | TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM; |
1da177e4 | 676 | ptm_driver->other = pts_driver; |
feebed65 | 677 | tty_set_operations(ptm_driver, &ptm_unix98_ops); |
1da177e4 LT |
678 | |
679 | pts_driver->owner = THIS_MODULE; | |
680 | pts_driver->driver_name = "pty_slave"; | |
681 | pts_driver->name = "pts"; | |
682 | pts_driver->major = UNIX98_PTY_SLAVE_MAJOR; | |
683 | pts_driver->minor_start = 0; | |
684 | pts_driver->type = TTY_DRIVER_TYPE_PTY; | |
685 | pts_driver->subtype = PTY_TYPE_SLAVE; | |
686 | pts_driver->init_termios = tty_std_termios; | |
687 | pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
606d099c AC |
688 | pts_driver->init_termios.c_ispeed = 38400; |
689 | pts_driver->init_termios.c_ospeed = 38400; | |
1da177e4 | 690 | pts_driver->flags = TTY_DRIVER_RESET_TERMIOS | TTY_DRIVER_REAL_RAW | |
331b8319 | 691 | TTY_DRIVER_DYNAMIC_DEV | TTY_DRIVER_DEVPTS_MEM; |
1da177e4 | 692 | pts_driver->other = ptm_driver; |
99f1fe18 | 693 | tty_set_operations(pts_driver, &pty_unix98_ops); |
fe9cd962 | 694 | |
1da177e4 LT |
695 | if (tty_register_driver(ptm_driver)) |
696 | panic("Couldn't register Unix98 ptm driver"); | |
697 | if (tty_register_driver(pts_driver)) | |
698 | panic("Couldn't register Unix98 pts driver"); | |
699 | ||
fe9cd962 | 700 | register_sysctl_table(pty_root_table); |
d81ed103 AC |
701 | |
702 | /* Now create the /dev/ptmx special device */ | |
703 | tty_default_fops(&ptmx_fops); | |
704 | ptmx_fops.open = ptmx_open; | |
705 | ||
706 | cdev_init(&ptmx_cdev, &ptmx_fops); | |
707 | if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) || | |
708 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0) | |
709 | panic("Couldn't register /dev/ptmx driver\n"); | |
710 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx"); | |
1da177e4 | 711 | } |
d81ed103 | 712 | |
1da177e4 LT |
713 | #else |
714 | static inline void unix98_pty_init(void) { } | |
715 | #endif | |
716 | ||
717 | static int __init pty_init(void) | |
718 | { | |
719 | legacy_pty_init(); | |
720 | unix98_pty_init(); | |
721 | return 0; | |
722 | } | |
723 | module_init(pty_init); |