blob: a82b39939a9cab4fc02a6d6d0be13607284d68ce [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * 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
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 *
Alan Coxfe9cd962008-10-13 10:43:38 +01007 * 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.
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 */
11
Alan Coxfe9cd962008-10-13 10:43:38 +010012#include <linux/module.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013
14#include <linux/errno.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/interrupt.h>
16#include <linux/tty.h>
17#include <linux/tty_flip.h>
18#include <linux/fcntl.h>
Alexey Dobriyand43c36d2009-10-07 17:09:06 +040019#include <linux/sched.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <linux/string.h>
21#include <linux/major.h>
22#include <linux/mm.h>
23#include <linux/init.h>
Alan Coxd81ed102008-10-13 10:41:42 +010024#include <linux/device.h>
Alan Coxfe9cd962008-10-13 10:43:38 +010025#include <linux/uaccess.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026#include <linux/bitops.h>
27#include <linux/devpts_fs.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090028#include <linux/slab.h>
Alan Coxd739e652012-05-03 22:22:09 +010029#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030
Alan Coxfe9cd962008-10-13 10:43:38 +010031
Linus Torvalds1da177e2005-04-16 15:20:36 -070032#ifdef CONFIG_UNIX98_PTYS
Roel Kluinda2bdf92009-01-07 18:09:15 -080033static struct tty_driver *ptm_driver;
Linus Torvalds1da177e2005-04-16 15:20:36 -070034static struct tty_driver *pts_driver;
Alan Coxd739e652012-05-03 22:22:09 +010035static DEFINE_MUTEX(devpts_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070036#endif
37
Alan Coxfe9cd962008-10-13 10:43:38 +010038static void pty_close(struct tty_struct *tty, struct file *filp)
Linus Torvalds1da177e2005-04-16 15:20:36 -070039{
Alan Coxfe9cd962008-10-13 10:43:38 +010040 BUG_ON(!tty);
41 if (tty->driver->subtype == PTY_TYPE_MASTER)
42 WARN_ON(tty->count > 1);
43 else {
Linus Torvalds1da177e2005-04-16 15:20:36 -070044 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;
Alan Cox89c8d912012-08-08 16:30:13 +010050 /* Review - krefs on tty_link ?? */
Linus Torvalds1da177e2005-04-16 15:20:36 -070051 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);
Greg Kroah-Hartmance1000d2012-02-24 13:56:36 -080059#ifdef CONFIG_UNIX98_PTYS
Alan Coxd739e652012-05-03 22:22:09 +010060 if (tty->driver == ptm_driver) {
61 mutex_lock(&devpts_mutex);
Greg Kroah-Hartmance1000d2012-02-24 13:56:36 -080062 devpts_pty_kill(tty->link);
Alan Coxd739e652012-05-03 22:22:09 +010063 mutex_unlock(&devpts_mutex);
64 }
Greg Kroah-Hartmance1000d2012-02-24 13:56:36 -080065#endif
Alan Cox89c8d912012-08-08 16:30:13 +010066 tty_unlock(tty);
Arnd Bergmann11dbf202010-06-18 14:58:07 +020067 tty_vhangup(tty->link);
Alan Cox89c8d912012-08-08 16:30:13 +010068 tty_lock(tty);
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 }
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
Alan Coxfe9cd962008-10-13 10:43:38 +010076 * unthrottle routine when there are fewer than TTY_THRESHOLD_UNTHROTTLE
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 * 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 */
Alan Coxfe9cd962008-10-13 10:43:38 +010082static void pty_unthrottle(struct tty_struct *tty)
Linus Torvalds1da177e2005-04-16 15:20:36 -070083{
Alan Coxd945cb92009-07-07 16:39:41 +010084 tty_wakeup(tty->link);
Linus Torvalds1da177e2005-04-16 15:20:36 -070085 set_bit(TTY_THROTTLED, &tty->flags);
86}
87
Alan Coxd945cb92009-07-07 16:39:41 +010088/**
89 * pty_space - report space left for writing
90 * @to: tty we are writing into
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 *
Alan Coxd945cb92009-07-07 16:39:41 +010092 * 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070095 */
Alan Coxd945cb92009-07-07 16:39:41 +010096
97static 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
110 *
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.
115 */
116
Linus Torvaldsac89a912009-09-05 13:27:10 -0700117static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118{
119 struct tty_struct *to = tty->link;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120
Alan Coxd945cb92009-07-07 16:39:41 +0100121 if (tty->stopped)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 return 0;
123
Alan Coxd945cb92009-07-07 16:39:41 +0100124 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 */
Linus Torvalds202c4672009-09-18 07:05:58 -0700128 if (c) {
129 tty_flip_buffer_push(to);
130 tty_wakeup(tty);
131 }
Alan Cox762faae2009-06-16 17:01:13 +0100132 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 return c;
134}
135
Alan Coxd945cb92009-07-07 16:39:41 +0100136/**
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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144static int pty_write_room(struct tty_struct *tty)
145{
Linus Torvalds85dfd812009-08-10 13:21:19 -0700146 if (tty->stopped)
147 return 0;
Alan Coxd945cb92009-07-07 16:39:41 +0100148 return pty_space(tty->link);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149}
150
Alan Coxd945cb92009-07-07 16:39:41 +0100151/**
152 * pty_chars_in_buffer - characters currently in our tx queue
153 * @tty: our tty
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 *
Alan Coxd945cb92009-07-07 16:39:41 +0100155 * Report how much we have in the transmit queue. As everything is
156 * instantly at the other end this is easy to implement.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 */
Alan Coxd945cb92009-07-07 16:39:41 +0100158
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159static int pty_chars_in_buffer(struct tty_struct *tty)
160{
Alan Coxd945cb92009-07-07 16:39:41 +0100161 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162}
163
164/* Set the lock flag on a pty */
Alan Coxfe9cd962008-10-13 10:43:38 +0100165static int pty_set_lock(struct tty_struct *tty, int __user *arg)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166{
167 int val;
Alan Coxfe9cd962008-10-13 10:43:38 +0100168 if (get_user(val, arg))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 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
hyc@symas.com26df6d12010-06-22 10:14:49 -0700177/* Send a signal to the slave */
178static 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194static void pty_flush_buffer(struct tty_struct *tty)
195{
196 struct tty_struct *to = tty->link;
Alan Cox04f378b2008-04-30 00:53:29 -0700197 unsigned long flags;
Alan Coxfe9cd962008-10-13 10:43:38 +0100198
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 if (!to)
200 return;
Alan Coxd945cb92009-07-07 16:39:41 +0100201 /* tty_buffer_flush(to); FIXME */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 if (to->packet) {
Alan Cox04f378b2008-04-30 00:53:29 -0700203 spin_lock_irqsave(&tty->ctrl_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 tty->ctrl_status |= TIOCPKT_FLUSHWRITE;
205 wake_up_interruptible(&to->read_wait);
Alan Cox04f378b2008-04-30 00:53:29 -0700206 spin_unlock_irqrestore(&tty->ctrl_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207 }
208}
209
Alan Coxfe9cd962008-10-13 10:43:38 +0100210static int pty_open(struct tty_struct *tty, struct file *filp)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211{
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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227 retval = 0;
228out:
229 return retval;
230}
231
Alan Coxfe9cd962008-10-13 10:43:38 +0100232static void pty_set_termios(struct tty_struct *tty,
233 struct ktermios *old_termios)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234{
Alan Coxadc8d742012-07-14 15:31:47 +0100235 tty->termios.c_cflag &= ~(CSIZE | PARENB);
236 tty->termios.c_cflag |= (CS8 | CREAD);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237}
238
Alan Coxfc6f6232009-01-02 13:43:17 +0000239/**
240 * pty_do_resize - resize event
241 * @tty: tty being resized
Alan Coxc774bda2009-01-11 19:46:49 +0000242 * @ws: window size being set.
Alan Coxfc6f6232009-01-02 13:43:17 +0000243 *
Daniel Mack3ad2f3f2010-02-03 08:01:28 +0800244 * Update the termios variables and send the necessary signals to
Alan Coxfc6f6232009-01-02 13:43:17 +0000245 * peform a terminal resize correctly
246 */
247
248int 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 */
281done:
282 mutex_unlock(&tty->termios_mutex);
283 return 0;
284}
285
Alan Coxd1552552012-07-27 18:02:54 +0100286/**
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 */
Jiri Slaby5d249bc2012-06-04 13:35:29 +0200297static int pty_common_install(struct tty_driver *driver, struct tty_struct *tty,
298 bool legacy)
Alan Coxbf970ee2008-10-13 10:42:39 +0100299{
300 struct tty_struct *o_tty;
Jiri Slabyd03702a2012-06-04 13:35:30 +0200301 struct tty_port *ports[2];
Alan Coxbf970ee2008-10-13 10:42:39 +0100302 int idx = tty->index;
Jiri Slaby5d249bc2012-06-04 13:35:29 +0200303 int retval = -ENOMEM;
Alan Coxbf970ee2008-10-13 10:42:39 +0100304
305 o_tty = alloc_tty_struct();
Jiri Slaby6f9ea7a2012-08-07 21:47:26 +0200306 if (!o_tty)
307 goto err;
Jiri Slabyd03702a2012-06-04 13:35:30 +0200308 ports[0] = kmalloc(sizeof **ports, GFP_KERNEL);
309 ports[1] = kmalloc(sizeof **ports, GFP_KERNEL);
Jiri Slaby6f9ea7a2012-08-07 21:47:26 +0200310 if (!ports[0] || !ports[1])
Jiri Slabyd03702a2012-06-04 13:35:30 +0200311 goto err_free_tty;
Alan Coxbf970ee2008-10-13 10:42:39 +0100312 if (!try_module_get(driver->other->owner)) {
313 /* This cannot in fact currently happen */
Jiri Slaby8a1b8d72011-03-23 10:48:33 +0100314 goto err_free_tty;
Alan Coxbf970ee2008-10-13 10:42:39 +0100315 }
316 initialize_tty_struct(o_tty, driver->other, idx);
317
Jiri Slaby5d249bc2012-06-04 13:35:29 +0200318 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;
Alan Coxbf970ee2008-10-13 10:42:39 +0100324
Jiri Slaby5d249bc2012-06-04 13:35:29 +0200325 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 {
Alan Coxadc8d742012-07-14 15:31:47 +0100332 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;
Jiri Slaby5d249bc2012-06-04 13:35:29 +0200336 }
Alan Coxfe9cd962008-10-13 10:43:38 +0100337
Alan Coxbf970ee2008-10-13 10:42:39 +0100338 /*
339 * Everything allocated ... set up the o_tty structure.
340 */
Alan Coxbf970ee2008-10-13 10:42:39 +0100341 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;
Jiri Slabyd03702a2012-06-04 13:35:30 +0200347 tty_port_init(ports[0]);
348 tty_port_init(ports[1]);
349 o_tty->port = ports[0];
350 tty->port = ports[1];
Alan Coxbf970ee2008-10-13 10:42:39 +0100351
352 tty_driver_kref_get(driver);
353 tty->count++;
Alan Coxbf970ee2008-10-13 10:42:39 +0100354 return 0;
Jiri Slaby8a1b8d72011-03-23 10:48:33 +0100355err_free_termios:
Jiri Slaby5d249bc2012-06-04 13:35:29 +0200356 if (legacy)
357 tty_free_termios(tty);
Jiri Slabya9dccdd2011-03-23 10:48:36 +0100358err_deinit_tty:
359 deinitialize_tty_struct(o_tty);
Alan Coxbf970ee2008-10-13 10:42:39 +0100360 module_put(o_tty->driver->owner);
Jiri Slaby8a1b8d72011-03-23 10:48:33 +0100361err_free_tty:
Jiri Slabyd03702a2012-06-04 13:35:30 +0200362 kfree(ports[0]);
363 kfree(ports[1]);
Alan Coxbf970ee2008-10-13 10:42:39 +0100364 free_tty_struct(o_tty);
Jiri Slaby6f9ea7a2012-08-07 21:47:26 +0200365err:
Jiri Slaby8a1b8d72011-03-23 10:48:33 +0100366 return retval;
Alan Coxbf970ee2008-10-13 10:42:39 +0100367}
368
Jiri Slabyd03702a2012-06-04 13:35:30 +0200369static void pty_cleanup(struct tty_struct *tty)
370{
371 kfree(tty->port);
372}
373
Jiri Slaby5d249bc2012-06-04 13:35:29 +0200374/* Traditional BSD devices */
375#ifdef CONFIG_LEGACY_PTYS
376
377static int pty_install(struct tty_driver *driver, struct tty_struct *tty)
378{
379 return pty_common_install(driver, tty, true);
380}
381
Alan Coxd1552552012-07-27 18:02:54 +0100382static 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
Alan Cox6caa76b2011-02-14 16:27:22 +0000390static int pty_bsd_ioctl(struct tty_struct *tty,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 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);
hyc@symas.com26df6d12010-06-22 10:14:49 -0700396 case TIOCSIG: /* Send signal to other side of pty */
397 return pty_signal(tty, (int) arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 }
399 return -ENOIOCTLCMD;
400}
401
Kay Sieversdc8c8582007-08-15 12:25:38 +0200402static int legacy_count = CONFIG_LEGACY_PTY_COUNT;
403module_param(legacy_count, int, 0);
404
Linus Torvalds342a5972009-09-30 07:49:40 -0700405/*
406 * The master side of a pty can do TIOCSPTLCK and thus
407 * has pty_bsd_ioctl.
408 */
409static const struct tty_operations master_pty_ops_bsd = {
410 .install = pty_install,
Alan Cox3e8e88c2008-04-30 00:54:10 -0700411 .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,
Jiri Slabyd03702a2012-06-04 13:35:30 +0200420 .cleanup = pty_cleanup,
Alan Coxd1552552012-07-27 18:02:54 +0100421 .resize = pty_resize,
422 .remove = pty_remove
Alan Cox3e8e88c2008-04-30 00:54:10 -0700423};
424
Linus Torvalds342a5972009-09-30 07:49:40 -0700425static 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,
Jiri Slabyd03702a2012-06-04 13:35:30 +0200435 .cleanup = pty_cleanup,
Alan Coxd1552552012-07-27 18:02:54 +0100436 .resize = pty_resize,
437 .remove = pty_remove
Linus Torvalds342a5972009-09-30 07:49:40 -0700438};
439
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440static void __init legacy_pty_init(void)
441{
Linus Torvalds342a5972009-09-30 07:49:40 -0700442 struct tty_driver *pty_driver, *pty_slave_driver;
443
Kay Sieversdc8c8582007-08-15 12:25:38 +0200444 if (legacy_count <= 0)
445 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446
Jiri Slaby21aca2f2012-08-08 22:26:41 +0200447 pty_driver = tty_alloc_driver(legacy_count,
448 TTY_DRIVER_RESET_TERMIOS |
449 TTY_DRIVER_REAL_RAW |
450 TTY_DRIVER_DYNAMIC_ALLOC);
Dan Carpenterc3a63442012-08-16 16:16:56 +0300451 if (IS_ERR(pty_driver))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452 panic("Couldn't allocate pty driver");
453
Jiri Slaby21aca2f2012-08-08 22:26:41 +0200454 pty_slave_driver = tty_alloc_driver(legacy_count,
455 TTY_DRIVER_RESET_TERMIOS |
456 TTY_DRIVER_REAL_RAW |
457 TTY_DRIVER_DYNAMIC_ALLOC);
Dan Carpenterc3a63442012-08-16 16:16:56 +0300458 if (IS_ERR(pty_slave_driver))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700459 panic("Couldn't allocate pty slave driver");
460
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 pty_driver->driver_name = "pty_master";
462 pty_driver->name = "pty";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463 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;
Alan Cox606d0992006-12-08 02:38:45 -0800472 pty_driver->init_termios.c_ispeed = 38400;
473 pty_driver->init_termios.c_ospeed = 38400;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 pty_driver->other = pty_slave_driver;
Linus Torvalds342a5972009-09-30 07:49:40 -0700475 tty_set_operations(pty_driver, &master_pty_ops_bsd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476
Linus Torvalds1da177e2005-04-16 15:20:36 -0700477 pty_slave_driver->driver_name = "pty_slave";
478 pty_slave_driver->name = "ttyp";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479 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;
Alan Cox606d0992006-12-08 02:38:45 -0800485 pty_slave_driver->init_termios.c_ispeed = 38400;
486 pty_slave_driver->init_termios.c_ospeed = 38400;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 pty_slave_driver->other = pty_driver;
Linus Torvalds342a5972009-09-30 07:49:40 -0700488 tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489
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
496static inline void legacy_pty_init(void) { }
497#endif
498
499/* Unix98 devices */
500#ifdef CONFIG_UNIX98_PTYS
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501
Alan Coxd81ed102008-10-13 10:41:42 +0100502static struct cdev ptmx_cdev;
503
Alan Cox6caa76b2011-02-14 16:27:22 +0000504static int pty_unix98_ioctl(struct tty_struct *tty,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505 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);
hyc@symas.com26df6d12010-06-22 10:14:49 -0700512 case TIOCSIG: /* Send signal to other side of pty */
513 return pty_signal(tty, (int) arg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 }
515
516 return -ENOIOCTLCMD;
517}
518
Alan Cox99f1fe12008-10-13 10:42:00 +0100519/**
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
Sukadev Bhattiprolu15f1a632008-10-13 10:42:59 +0100528static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver,
529 struct inode *ptm_inode, int idx)
Alan Cox99f1fe12008-10-13 10:42:00 +0100530{
Konstantin Khlebnikov593a27c2012-01-05 13:04:21 +0400531 /* Master must be open via /dev/ptmx */
532 return ERR_PTR(-EIO);
Alan Cox99f1fe12008-10-13 10:42:00 +0100533}
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.
Alan Coxd739e652012-05-03 22:22:09 +0100541 * This provides our locking for the tty pointer.
Alan Cox99f1fe12008-10-13 10:42:00 +0100542 */
543
Sukadev Bhattiprolu15f1a632008-10-13 10:42:59 +0100544static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver,
545 struct inode *pts_inode, int idx)
Alan Cox99f1fe12008-10-13 10:42:00 +0100546{
Alan Coxd739e652012-05-03 22:22:09 +0100547 struct tty_struct *tty;
548
549 mutex_lock(&devpts_mutex);
550 tty = devpts_get_tty(pts_inode, idx);
551 mutex_unlock(&devpts_mutex);
Alan Cox99f1fe12008-10-13 10:42:00 +0100552 /* Master must be open before slave */
553 if (!tty)
554 return ERR_PTR(-EIO);
555 return tty;
556}
557
Alan Cox8b0a88d2008-10-13 10:42:19 +0100558/* We have no need to install and remove our tty objects as devpts does all
559 the work for us */
560
Alan Coxbf970ee2008-10-13 10:42:39 +0100561static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty)
Alan Cox8b0a88d2008-10-13 10:42:19 +0100562{
Jiri Slaby5d249bc2012-06-04 13:35:29 +0200563 return pty_common_install(driver, tty, false);
Alan Cox8b0a88d2008-10-13 10:42:19 +0100564}
565
Jiri Slaby71716042012-06-04 13:35:28 +0200566static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty)
Jiri Slaby484af542011-11-16 16:27:11 +0100567{
Alan Cox8b0a88d2008-10-13 10:42:19 +0100568}
569
Alan Coxfeebed62008-10-13 10:41:30 +0100570static const struct tty_operations ptm_unix98_ops = {
Alan Cox99f1fe12008-10-13 10:42:00 +0100571 .lookup = ptm_unix98_lookup,
Alan Coxbf970ee2008-10-13 10:42:39 +0100572 .install = pty_unix98_install,
Jiri Slaby71716042012-06-04 13:35:28 +0200573 .remove = pty_unix98_remove,
Alan Cox3e8e88c2008-04-30 00:54:10 -0700574 .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,
Alan Coxfeebed62008-10-13 10:41:30 +0100582 .ioctl = pty_unix98_ioctl,
Alan Cox36b3c072012-07-17 17:06:57 +0100583 .resize = pty_resize,
584 .cleanup = pty_cleanup
Alan Cox3e8e88c2008-04-30 00:54:10 -0700585};
586
Alan Cox99f1fe12008-10-13 10:42:00 +0100587static const struct tty_operations pty_unix98_ops = {
588 .lookup = pts_unix98_lookup,
Alan Coxbf970ee2008-10-13 10:42:39 +0100589 .install = pty_unix98_install,
Jiri Slaby71716042012-06-04 13:35:28 +0200590 .remove = pty_unix98_remove,
Alan Cox99f1fe12008-10-13 10:42:00 +0100591 .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,
Jiri Slabyd03702a2012-06-04 13:35:30 +0200599 .cleanup = pty_cleanup,
Alan Cox99f1fe12008-10-13 10:42:00 +0100600};
Alan Coxd81ed102008-10-13 10:41:42 +0100601
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
Arnd Bergmann64ba3dc2010-06-01 22:53:02 +0200614static int ptmx_open(struct inode *inode, struct file *filp)
Alan Coxd81ed102008-10-13 10:41:42 +0100615{
616 struct tty_struct *tty;
617 int retval;
618 int index;
619
620 nonseekable_open(inode, filp);
621
Jiri Slabyfa90e1c2011-10-12 11:32:43 +0200622 retval = tty_alloc_file(filp);
623 if (retval)
624 return retval;
625
Alan Coxd81ed102008-10-13 10:41:42 +0100626 /* find a device that is not in use. */
Alan Cox89c8d912012-08-08 16:30:13 +0100627 mutex_lock(&devpts_mutex);
Sukadev Bhattiprolu15f1a632008-10-13 10:42:59 +0100628 index = devpts_new_index(inode);
Jiri Slabyfa90e1c2011-10-12 11:32:43 +0200629 if (index < 0) {
630 retval = index;
Alan Cox05fb79e2012-09-19 15:34:47 +0100631 mutex_unlock(&devpts_mutex);
Jiri Slabyfa90e1c2011-10-12 11:32:43 +0200632 goto err_file;
633 }
Alan Coxd81ed102008-10-13 10:41:42 +0100634
Alan Cox6d31a882012-07-14 15:31:27 +0100635 mutex_unlock(&devpts_mutex);
Alan Cox89c8d912012-08-08 16:30:13 +0100636
637 mutex_lock(&tty_mutex);
638 tty = tty_init_dev(ptm_driver, index);
Alan Coxd81ed102008-10-13 10:41:42 +0100639
Alan Cox73ec06f2008-10-13 10:42:29 +0100640 if (IS_ERR(tty)) {
641 retval = PTR_ERR(tty);
Alan Coxd81ed102008-10-13 10:41:42 +0100642 goto out;
Alan Cox73ec06f2008-10-13 10:42:29 +0100643 }
Alan Coxd81ed102008-10-13 10:41:42 +0100644
Alan Cox89c8d912012-08-08 16:30:13 +0100645 /* The tty returned here is locked so we can safely
646 drop the mutex */
647 mutex_unlock(&tty_mutex);
648
Alan Coxd81ed102008-10-13 10:41:42 +0100649 set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */
Nick Pigginee2ffa02010-08-18 04:37:35 +1000650
Jiri Slabyfa90e1c2011-10-12 11:32:43 +0200651 tty_add_file(tty, filp);
Alan Coxd81ed102008-10-13 10:41:42 +0100652
Sukadev Bhattiprolu15f1a632008-10-13 10:42:59 +0100653 retval = devpts_pty_new(inode, tty->link);
Alan Coxd81ed102008-10-13 10:41:42 +0100654 if (retval)
Jiri Slaby1177c0e2011-10-12 11:32:44 +0200655 goto err_release;
Alan Coxd81ed102008-10-13 10:41:42 +0100656
657 retval = ptm_driver->ops->open(tty, filp);
Arnd Bergmann64ba3dc2010-06-01 22:53:02 +0200658 if (retval)
Jiri Slaby1177c0e2011-10-12 11:32:44 +0200659 goto err_release;
660
Alan Cox89c8d912012-08-08 16:30:13 +0100661 tty_unlock(tty);
Jiri Slaby1177c0e2011-10-12 11:32:44 +0200662 return 0;
663err_release:
Alan Cox89c8d912012-08-08 16:30:13 +0100664 tty_unlock(tty);
Alan Coxeeb89d92009-11-30 13:18:29 +0000665 tty_release(inode, filp);
Alan Coxd81ed102008-10-13 10:41:42 +0100666 return retval;
667out:
Alan Cox89c8d912012-08-08 16:30:13 +0100668 mutex_unlock(&tty_mutex);
Jiri Slabyd3bda522012-01-30 21:14:32 +0100669 devpts_kill_index(inode, index);
Jiri Slabyfa90e1c2011-10-12 11:32:43 +0200670err_file:
671 tty_free_file(filp);
Arnd Bergmann64ba3dc2010-06-01 22:53:02 +0200672 return retval;
Alan Coxd81ed102008-10-13 10:41:42 +0100673}
674
675static struct file_operations ptmx_fops;
676
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677static void __init unix98_pty_init(void)
678{
Jiri Slaby21aca2f2012-08-08 22:26:41 +0200679 ptm_driver = tty_alloc_driver(NR_UNIX98_PTY_MAX,
680 TTY_DRIVER_RESET_TERMIOS |
681 TTY_DRIVER_REAL_RAW |
682 TTY_DRIVER_DYNAMIC_DEV |
683 TTY_DRIVER_DEVPTS_MEM |
684 TTY_DRIVER_DYNAMIC_ALLOC);
Dan Carpenterc3a63442012-08-16 16:16:56 +0300685 if (IS_ERR(ptm_driver))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686 panic("Couldn't allocate Unix98 ptm driver");
Jiri Slaby21aca2f2012-08-08 22:26:41 +0200687 pts_driver = tty_alloc_driver(NR_UNIX98_PTY_MAX,
688 TTY_DRIVER_RESET_TERMIOS |
689 TTY_DRIVER_REAL_RAW |
690 TTY_DRIVER_DYNAMIC_DEV |
691 TTY_DRIVER_DEVPTS_MEM |
692 TTY_DRIVER_DYNAMIC_ALLOC);
Dan Carpenterc3a63442012-08-16 16:16:56 +0300693 if (IS_ERR(pts_driver))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694 panic("Couldn't allocate Unix98 pts driver");
695
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696 ptm_driver->driver_name = "pty_master";
697 ptm_driver->name = "ptm";
698 ptm_driver->major = UNIX98_PTY_MASTER_MAJOR;
699 ptm_driver->minor_start = 0;
700 ptm_driver->type = TTY_DRIVER_TYPE_PTY;
701 ptm_driver->subtype = PTY_TYPE_MASTER;
702 ptm_driver->init_termios = tty_std_termios;
703 ptm_driver->init_termios.c_iflag = 0;
704 ptm_driver->init_termios.c_oflag = 0;
705 ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
706 ptm_driver->init_termios.c_lflag = 0;
Alan Cox606d0992006-12-08 02:38:45 -0800707 ptm_driver->init_termios.c_ispeed = 38400;
708 ptm_driver->init_termios.c_ospeed = 38400;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709 ptm_driver->other = pts_driver;
Alan Coxfeebed62008-10-13 10:41:30 +0100710 tty_set_operations(ptm_driver, &ptm_unix98_ops);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712 pts_driver->driver_name = "pty_slave";
713 pts_driver->name = "pts";
714 pts_driver->major = UNIX98_PTY_SLAVE_MAJOR;
715 pts_driver->minor_start = 0;
716 pts_driver->type = TTY_DRIVER_TYPE_PTY;
717 pts_driver->subtype = PTY_TYPE_SLAVE;
718 pts_driver->init_termios = tty_std_termios;
719 pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD;
Alan Cox606d0992006-12-08 02:38:45 -0800720 pts_driver->init_termios.c_ispeed = 38400;
721 pts_driver->init_termios.c_ospeed = 38400;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722 pts_driver->other = ptm_driver;
Alan Cox99f1fe12008-10-13 10:42:00 +0100723 tty_set_operations(pts_driver, &pty_unix98_ops);
Alan Coxfe9cd962008-10-13 10:43:38 +0100724
Linus Torvalds1da177e2005-04-16 15:20:36 -0700725 if (tty_register_driver(ptm_driver))
726 panic("Couldn't register Unix98 ptm driver");
727 if (tty_register_driver(pts_driver))
728 panic("Couldn't register Unix98 pts driver");
729
Alan Coxd81ed102008-10-13 10:41:42 +0100730 /* Now create the /dev/ptmx special device */
731 tty_default_fops(&ptmx_fops);
732 ptmx_fops.open = ptmx_open;
733
734 cdev_init(&ptmx_cdev, &ptmx_fops);
735 if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) ||
736 register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0)
737 panic("Couldn't register /dev/ptmx driver\n");
738 device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700739}
Alan Coxd81ed102008-10-13 10:41:42 +0100740
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741#else
742static inline void unix98_pty_init(void) { }
743#endif
744
745static int __init pty_init(void)
746{
747 legacy_pty_init();
748 unix98_pty_init();
749 return 0;
750}
751module_init(pty_init);