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Commit | Line | Data |
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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 | * |
1da177e4 LT |
7 | */ |
8 | ||
fe9cd962 | 9 | #include <linux/module.h> |
1da177e4 | 10 | #include <linux/errno.h> |
1da177e4 LT |
11 | #include <linux/interrupt.h> |
12 | #include <linux/tty.h> | |
13 | #include <linux/tty_flip.h> | |
14 | #include <linux/fcntl.h> | |
3f07c014 | 15 | #include <linux/sched/signal.h> |
1da177e4 LT |
16 | #include <linux/string.h> |
17 | #include <linux/major.h> | |
18 | #include <linux/mm.h> | |
19 | #include <linux/init.h> | |
d81ed103 | 20 | #include <linux/device.h> |
fe9cd962 | 21 | #include <linux/uaccess.h> |
1da177e4 LT |
22 | #include <linux/bitops.h> |
23 | #include <linux/devpts_fs.h> | |
5a0e3ad6 | 24 | #include <linux/slab.h> |
d739e65b | 25 | #include <linux/mutex.h> |
01adc807 | 26 | #include <linux/poll.h> |
1da177e4 | 27 | |
d6847793 PH |
28 | #undef TTY_DEBUG_HANGUP |
29 | #ifdef TTY_DEBUG_HANGUP | |
30 | # define tty_debug_hangup(tty, f, args...) tty_debug(tty, f, ##args) | |
31 | #else | |
32 | # define tty_debug_hangup(tty, f, args...) do {} while (0) | |
33 | #endif | |
fe9cd962 | 34 | |
1da177e4 | 35 | #ifdef CONFIG_UNIX98_PTYS |
da2bdf9a | 36 | static struct tty_driver *ptm_driver; |
1da177e4 | 37 | static struct tty_driver *pts_driver; |
d739e65b | 38 | static DEFINE_MUTEX(devpts_mutex); |
1da177e4 LT |
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 { | |
18900ca6 | 47 | if (tty_io_error(tty)) |
69939035 | 48 | return; |
1da177e4 LT |
49 | if (tty->count > 2) |
50 | return; | |
51 | } | |
69939035 | 52 | set_bit(TTY_IO_ERROR, &tty->flags); |
1da177e4 LT |
53 | wake_up_interruptible(&tty->read_wait); |
54 | wake_up_interruptible(&tty->write_wait); | |
4ed60fc2 | 55 | spin_lock_irq(&tty->ctrl_lock); |
1da177e4 | 56 | tty->packet = 0; |
4ed60fc2 | 57 | spin_unlock_irq(&tty->ctrl_lock); |
89c8d91e | 58 | /* Review - krefs on tty_link ?? */ |
1da177e4 LT |
59 | if (!tty->link) |
60 | return; | |
1da177e4 | 61 | set_bit(TTY_OTHER_CLOSED, &tty->link->flags); |
0f40fbbc | 62 | wake_up_interruptible(&tty->link->read_wait); |
1da177e4 LT |
63 | wake_up_interruptible(&tty->link->write_wait); |
64 | if (tty->driver->subtype == PTY_TYPE_MASTER) { | |
65 | set_bit(TTY_OTHER_CLOSED, &tty->flags); | |
ce1000dd | 66 | #ifdef CONFIG_UNIX98_PTYS |
d739e65b | 67 | if (tty->driver == ptm_driver) { |
b9f8033f | 68 | mutex_lock(&devpts_mutex); |
7acf6cd8 PH |
69 | if (tty->link->driver_data) |
70 | devpts_pty_kill(tty->link->driver_data); | |
b9f8033f | 71 | mutex_unlock(&devpts_mutex); |
d739e65b | 72 | } |
ce1000dd | 73 | #endif |
11dbf203 | 74 | tty_vhangup(tty->link); |
1da177e4 LT |
75 | } |
76 | } | |
77 | ||
78 | /* | |
79 | * The unthrottle routine is called by the line discipline to signal | |
80 | * that it can receive more characters. For PTY's, the TTY_THROTTLED | |
81 | * flag is always set, to force the line discipline to always call the | |
fe9cd962 | 82 | * unthrottle routine when there are fewer than TTY_THRESHOLD_UNTHROTTLE |
1da177e4 LT |
83 | * characters in the queue. This is necessary since each time this |
84 | * happens, we need to wake up any sleeping processes that could be | |
85 | * (1) trying to send data to the pty, or (2) waiting in wait_until_sent() | |
86 | * for the pty buffer to be drained. | |
87 | */ | |
fe9cd962 | 88 | static void pty_unthrottle(struct tty_struct *tty) |
1da177e4 | 89 | { |
d945cb9c | 90 | tty_wakeup(tty->link); |
1da177e4 LT |
91 | set_bit(TTY_THROTTLED, &tty->flags); |
92 | } | |
93 | ||
d945cb9c AC |
94 | /** |
95 | * pty_write - write to a pty | |
96 | * @tty: the tty we write from | |
97 | * @buf: kernel buffer of data | |
98 | * @count: bytes to write | |
762faaed | 99 | * |
d945cb9c AC |
100 | * Our "hardware" write method. Data is coming from the ldisc which |
101 | * may be in a non sleeping state. We simply throw this at the other | |
102 | * end of the link as if we were an IRQ handler receiving stuff for | |
103 | * the other side of the pty/tty pair. | |
1da177e4 | 104 | */ |
d945cb9c | 105 | |
ac89a917 | 106 | static int pty_write(struct tty_struct *tty, const unsigned char *buf, int c) |
1da177e4 LT |
107 | { |
108 | struct tty_struct *to = tty->link; | |
1da177e4 | 109 | |
d945cb9c | 110 | if (tty->stopped) |
1da177e4 | 111 | return 0; |
d945cb9c | 112 | |
d945cb9c AC |
113 | if (c > 0) { |
114 | /* Stuff the data into the input queue of the other end */ | |
05c7cd39 | 115 | c = tty_insert_flip_string(to->port, buf, c); |
d945cb9c | 116 | /* And shovel */ |
5ede5253 | 117 | if (c) |
2e124b4a | 118 | tty_flip_buffer_push(to->port); |
762faaed | 119 | } |
1da177e4 LT |
120 | return c; |
121 | } | |
122 | ||
d945cb9c AC |
123 | /** |
124 | * pty_write_room - write space | |
125 | * @tty: tty we are writing from | |
126 | * | |
127 | * Report how many bytes the ldisc can send into the queue for | |
128 | * the other device. | |
129 | */ | |
130 | ||
1da177e4 LT |
131 | static int pty_write_room(struct tty_struct *tty) |
132 | { | |
85dfd81d LT |
133 | if (tty->stopped) |
134 | return 0; | |
c81622ac | 135 | return tty_buffer_space_avail(tty->link->port); |
1da177e4 LT |
136 | } |
137 | ||
d945cb9c AC |
138 | /** |
139 | * pty_chars_in_buffer - characters currently in our tx queue | |
140 | * @tty: our tty | |
fe9cd962 | 141 | * |
d945cb9c AC |
142 | * Report how much we have in the transmit queue. As everything is |
143 | * instantly at the other end this is easy to implement. | |
1da177e4 | 144 | */ |
d945cb9c | 145 | |
1da177e4 LT |
146 | static int pty_chars_in_buffer(struct tty_struct *tty) |
147 | { | |
d945cb9c | 148 | return 0; |
1da177e4 LT |
149 | } |
150 | ||
151 | /* Set the lock flag on a pty */ | |
fe9cd962 | 152 | static int pty_set_lock(struct tty_struct *tty, int __user *arg) |
1da177e4 LT |
153 | { |
154 | int val; | |
fe9cd962 | 155 | if (get_user(val, arg)) |
1da177e4 LT |
156 | return -EFAULT; |
157 | if (val) | |
158 | set_bit(TTY_PTY_LOCK, &tty->flags); | |
159 | else | |
160 | clear_bit(TTY_PTY_LOCK, &tty->flags); | |
161 | return 0; | |
162 | } | |
163 | ||
84fd7bdf CG |
164 | static int pty_get_lock(struct tty_struct *tty, int __user *arg) |
165 | { | |
166 | int locked = test_bit(TTY_PTY_LOCK, &tty->flags); | |
167 | return put_user(locked, arg); | |
168 | } | |
169 | ||
06026d91 CG |
170 | /* Set the packet mode on a pty */ |
171 | static int pty_set_pktmode(struct tty_struct *tty, int __user *arg) | |
172 | { | |
06026d91 CG |
173 | int pktmode; |
174 | ||
175 | if (get_user(pktmode, arg)) | |
176 | return -EFAULT; | |
177 | ||
6054c16e | 178 | spin_lock_irq(&tty->ctrl_lock); |
06026d91 CG |
179 | if (pktmode) { |
180 | if (!tty->packet) { | |
06026d91 | 181 | tty->link->ctrl_status = 0; |
2622d73e PH |
182 | smp_mb(); |
183 | tty->packet = 1; | |
06026d91 CG |
184 | } |
185 | } else | |
186 | tty->packet = 0; | |
6054c16e | 187 | spin_unlock_irq(&tty->ctrl_lock); |
06026d91 CG |
188 | |
189 | return 0; | |
190 | } | |
191 | ||
84fd7bdf CG |
192 | /* Get the packet mode of a pty */ |
193 | static int pty_get_pktmode(struct tty_struct *tty, int __user *arg) | |
194 | { | |
195 | int pktmode = tty->packet; | |
196 | return put_user(pktmode, arg); | |
197 | } | |
198 | ||
26df6d13 | 199 | /* Send a signal to the slave */ |
200 | static int pty_signal(struct tty_struct *tty, int sig) | |
201 | { | |
26df6d13 | 202 | struct pid *pgrp; |
203 | ||
37480a05 PH |
204 | if (sig != SIGINT && sig != SIGQUIT && sig != SIGTSTP) |
205 | return -EINVAL; | |
206 | ||
26df6d13 | 207 | if (tty->link) { |
5b239542 PH |
208 | pgrp = tty_get_pgrp(tty->link); |
209 | if (pgrp) | |
210 | kill_pgrp(pgrp, sig, 1); | |
26df6d13 | 211 | put_pid(pgrp); |
212 | } | |
213 | return 0; | |
214 | } | |
215 | ||
1da177e4 LT |
216 | static void pty_flush_buffer(struct tty_struct *tty) |
217 | { | |
218 | struct tty_struct *to = tty->link; | |
fe9cd962 | 219 | |
1da177e4 LT |
220 | if (!to) |
221 | return; | |
1d1d14da | 222 | |
77dae613 | 223 | tty_buffer_flush(to, NULL); |
1da177e4 | 224 | if (to->packet) { |
6054c16e | 225 | spin_lock_irq(&tty->ctrl_lock); |
1da177e4 LT |
226 | tty->ctrl_status |= TIOCPKT_FLUSHWRITE; |
227 | wake_up_interruptible(&to->read_wait); | |
6054c16e | 228 | spin_unlock_irq(&tty->ctrl_lock); |
1da177e4 LT |
229 | } |
230 | } | |
231 | ||
fe9cd962 | 232 | static int pty_open(struct tty_struct *tty, struct file *filp) |
1da177e4 | 233 | { |
1da177e4 | 234 | if (!tty || !tty->link) |
7c61c3d8 | 235 | return -ENODEV; |
69939035 | 236 | |
1da177e4 LT |
237 | if (test_bit(TTY_OTHER_CLOSED, &tty->flags)) |
238 | goto out; | |
239 | if (test_bit(TTY_PTY_LOCK, &tty->link->flags)) | |
240 | goto out; | |
80cace72 | 241 | if (tty->driver->subtype == PTY_TYPE_SLAVE && tty->link->count != 1) |
1da177e4 LT |
242 | goto out; |
243 | ||
69939035 | 244 | clear_bit(TTY_IO_ERROR, &tty->flags); |
1da177e4 LT |
245 | clear_bit(TTY_OTHER_CLOSED, &tty->link->flags); |
246 | set_bit(TTY_THROTTLED, &tty->flags); | |
7c61c3d8 PH |
247 | return 0; |
248 | ||
1da177e4 | 249 | out: |
7c61c3d8 PH |
250 | set_bit(TTY_IO_ERROR, &tty->flags); |
251 | return -EIO; | |
1da177e4 LT |
252 | } |
253 | ||
fe9cd962 AC |
254 | static void pty_set_termios(struct tty_struct *tty, |
255 | struct ktermios *old_termios) | |
1da177e4 | 256 | { |
dbfcd851 PH |
257 | /* See if packet mode change of state. */ |
258 | if (tty->link && tty->link->packet) { | |
9db276f8 | 259 | int extproc = (old_termios->c_lflag & EXTPROC) | L_EXTPROC(tty); |
dbfcd851 PH |
260 | int old_flow = ((old_termios->c_iflag & IXON) && |
261 | (old_termios->c_cc[VSTOP] == '\023') && | |
262 | (old_termios->c_cc[VSTART] == '\021')); | |
263 | int new_flow = (I_IXON(tty) && | |
264 | STOP_CHAR(tty) == '\023' && | |
265 | START_CHAR(tty) == '\021'); | |
266 | if ((old_flow != new_flow) || extproc) { | |
4d8c1dff | 267 | spin_lock_irq(&tty->ctrl_lock); |
dbfcd851 PH |
268 | if (old_flow != new_flow) { |
269 | tty->ctrl_status &= ~(TIOCPKT_DOSTOP | TIOCPKT_NOSTOP); | |
270 | if (new_flow) | |
271 | tty->ctrl_status |= TIOCPKT_DOSTOP; | |
272 | else | |
273 | tty->ctrl_status |= TIOCPKT_NOSTOP; | |
274 | } | |
275 | if (extproc) | |
276 | tty->ctrl_status |= TIOCPKT_IOCTL; | |
4d8c1dff | 277 | spin_unlock_irq(&tty->ctrl_lock); |
dbfcd851 PH |
278 | wake_up_interruptible(&tty->link->read_wait); |
279 | } | |
280 | } | |
281 | ||
adc8d746 AC |
282 | tty->termios.c_cflag &= ~(CSIZE | PARENB); |
283 | tty->termios.c_cflag |= (CS8 | CREAD); | |
1da177e4 LT |
284 | } |
285 | ||
fc6f6238 AC |
286 | /** |
287 | * pty_do_resize - resize event | |
288 | * @tty: tty being resized | |
c774bda2 | 289 | * @ws: window size being set. |
fc6f6238 | 290 | * |
3ad2f3fb | 291 | * Update the termios variables and send the necessary signals to |
fc6f6238 AC |
292 | * peform a terminal resize correctly |
293 | */ | |
294 | ||
159a8e92 | 295 | static int pty_resize(struct tty_struct *tty, struct winsize *ws) |
fc6f6238 AC |
296 | { |
297 | struct pid *pgrp, *rpgrp; | |
fc6f6238 AC |
298 | struct tty_struct *pty = tty->link; |
299 | ||
300 | /* For a PTY we need to lock the tty side */ | |
dee4a0be | 301 | mutex_lock(&tty->winsize_mutex); |
fc6f6238 AC |
302 | if (!memcmp(ws, &tty->winsize, sizeof(*ws))) |
303 | goto done; | |
304 | ||
5b239542 PH |
305 | /* Signal the foreground process group of both ptys */ |
306 | pgrp = tty_get_pgrp(tty); | |
307 | rpgrp = tty_get_pgrp(pty); | |
fc6f6238 AC |
308 | |
309 | if (pgrp) | |
310 | kill_pgrp(pgrp, SIGWINCH, 1); | |
311 | if (rpgrp != pgrp && rpgrp) | |
312 | kill_pgrp(rpgrp, SIGWINCH, 1); | |
313 | ||
314 | put_pid(pgrp); | |
315 | put_pid(rpgrp); | |
316 | ||
317 | tty->winsize = *ws; | |
318 | pty->winsize = *ws; /* Never used so will go away soon */ | |
319 | done: | |
dee4a0be | 320 | mutex_unlock(&tty->winsize_mutex); |
fc6f6238 AC |
321 | return 0; |
322 | } | |
323 | ||
01adc807 PH |
324 | /** |
325 | * pty_start - start() handler | |
326 | * pty_stop - stop() handler | |
327 | * @tty: tty being flow-controlled | |
328 | * | |
329 | * Propagates the TIOCPKT status to the master pty. | |
330 | * | |
331 | * NB: only the master pty can be in packet mode so only the slave | |
332 | * needs start()/stop() handlers | |
333 | */ | |
334 | static void pty_start(struct tty_struct *tty) | |
335 | { | |
336 | unsigned long flags; | |
337 | ||
01adc807 | 338 | if (tty->link && tty->link->packet) { |
54e8e5fc | 339 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
01adc807 PH |
340 | tty->ctrl_status &= ~TIOCPKT_STOP; |
341 | tty->ctrl_status |= TIOCPKT_START; | |
54e8e5fc | 342 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
01adc807 PH |
343 | wake_up_interruptible_poll(&tty->link->read_wait, POLLIN); |
344 | } | |
01adc807 PH |
345 | } |
346 | ||
347 | static void pty_stop(struct tty_struct *tty) | |
348 | { | |
349 | unsigned long flags; | |
350 | ||
01adc807 | 351 | if (tty->link && tty->link->packet) { |
54e8e5fc | 352 | spin_lock_irqsave(&tty->ctrl_lock, flags); |
01adc807 PH |
353 | tty->ctrl_status &= ~TIOCPKT_START; |
354 | tty->ctrl_status |= TIOCPKT_STOP; | |
54e8e5fc | 355 | spin_unlock_irqrestore(&tty->ctrl_lock, flags); |
01adc807 PH |
356 | wake_up_interruptible_poll(&tty->link->read_wait, POLLIN); |
357 | } | |
01adc807 PH |
358 | } |
359 | ||
d155255a AC |
360 | /** |
361 | * pty_common_install - set up the pty pair | |
362 | * @driver: the pty driver | |
363 | * @tty: the tty being instantiated | |
2c964a2f | 364 | * @legacy: true if this is BSD style |
d155255a AC |
365 | * |
366 | * Perform the initial set up for the tty/pty pair. Called from the | |
367 | * tty layer when the port is first opened. | |
368 | * | |
369 | * Locking: the caller must hold the tty_mutex | |
370 | */ | |
5d249bc6 JS |
371 | static int pty_common_install(struct tty_driver *driver, struct tty_struct *tty, |
372 | bool legacy) | |
bf970ee4 AC |
373 | { |
374 | struct tty_struct *o_tty; | |
d03702a2 | 375 | struct tty_port *ports[2]; |
bf970ee4 | 376 | int idx = tty->index; |
5d249bc6 | 377 | int retval = -ENOMEM; |
bf970ee4 | 378 | |
55199ea3 PH |
379 | /* Opening the slave first has always returned -EIO */ |
380 | if (driver->subtype != PTY_TYPE_MASTER) | |
381 | return -EIO; | |
382 | ||
d03702a2 JS |
383 | ports[0] = kmalloc(sizeof **ports, GFP_KERNEL); |
384 | ports[1] = kmalloc(sizeof **ports, GFP_KERNEL); | |
6f9ea7ad | 385 | if (!ports[0] || !ports[1]) |
2c964a2f | 386 | goto err; |
bf970ee4 AC |
387 | if (!try_module_get(driver->other->owner)) { |
388 | /* This cannot in fact currently happen */ | |
2c964a2f | 389 | goto err; |
bf970ee4 | 390 | } |
2c964a2f RV |
391 | o_tty = alloc_tty_struct(driver->other, idx); |
392 | if (!o_tty) | |
393 | goto err_put_module; | |
bf970ee4 | 394 | |
2febdb63 | 395 | tty_set_lock_subclass(o_tty); |
d2b6f447 | 396 | lockdep_set_subclass(&o_tty->termios_rwsem, TTY_LOCK_SLAVE); |
2febdb63 | 397 | |
5d249bc6 JS |
398 | if (legacy) { |
399 | /* We always use new tty termios data so we can do this | |
400 | the easy way .. */ | |
a3123fd0 PH |
401 | tty_init_termios(tty); |
402 | tty_init_termios(o_tty); | |
5d249bc6 JS |
403 | |
404 | driver->other->ttys[idx] = o_tty; | |
405 | driver->ttys[idx] = tty; | |
406 | } else { | |
adc8d746 AC |
407 | memset(&tty->termios_locked, 0, sizeof(tty->termios_locked)); |
408 | tty->termios = driver->init_termios; | |
409 | memset(&o_tty->termios_locked, 0, sizeof(tty->termios_locked)); | |
410 | o_tty->termios = driver->other->init_termios; | |
5d249bc6 | 411 | } |
fe9cd962 | 412 | |
bf970ee4 AC |
413 | /* |
414 | * Everything allocated ... set up the o_tty structure. | |
415 | */ | |
bf970ee4 | 416 | tty_driver_kref_get(driver->other); |
bf970ee4 AC |
417 | /* Establish the links in both directions */ |
418 | tty->link = o_tty; | |
419 | o_tty->link = tty; | |
d03702a2 JS |
420 | tty_port_init(ports[0]); |
421 | tty_port_init(ports[1]); | |
c81622ac PH |
422 | tty_buffer_set_limit(ports[0], 8192); |
423 | tty_buffer_set_limit(ports[1], 8192); | |
d03702a2 JS |
424 | o_tty->port = ports[0]; |
425 | tty->port = ports[1]; | |
967fab69 | 426 | o_tty->port->itty = o_tty; |
bf970ee4 | 427 | |
1d1d14da PH |
428 | tty_buffer_set_lock_subclass(o_tty->port); |
429 | ||
bf970ee4 AC |
430 | tty_driver_kref_get(driver); |
431 | tty->count++; | |
55199ea3 | 432 | o_tty->count++; |
bf970ee4 | 433 | return 0; |
a3123fd0 | 434 | |
2c964a2f | 435 | err_put_module: |
07584d4a | 436 | module_put(driver->other->owner); |
2c964a2f | 437 | err: |
d03702a2 JS |
438 | kfree(ports[0]); |
439 | kfree(ports[1]); | |
8a1b8d70 | 440 | return retval; |
bf970ee4 AC |
441 | } |
442 | ||
d03702a2 JS |
443 | static void pty_cleanup(struct tty_struct *tty) |
444 | { | |
81c79838 | 445 | tty_port_put(tty->port); |
d03702a2 JS |
446 | } |
447 | ||
5d249bc6 JS |
448 | /* Traditional BSD devices */ |
449 | #ifdef CONFIG_LEGACY_PTYS | |
450 | ||
451 | static int pty_install(struct tty_driver *driver, struct tty_struct *tty) | |
452 | { | |
453 | return pty_common_install(driver, tty, true); | |
454 | } | |
455 | ||
d155255a AC |
456 | static void pty_remove(struct tty_driver *driver, struct tty_struct *tty) |
457 | { | |
458 | struct tty_struct *pair = tty->link; | |
459 | driver->ttys[tty->index] = NULL; | |
460 | if (pair) | |
461 | pair->driver->ttys[pair->index] = NULL; | |
462 | } | |
463 | ||
6caa76b7 | 464 | static int pty_bsd_ioctl(struct tty_struct *tty, |
1da177e4 LT |
465 | unsigned int cmd, unsigned long arg) |
466 | { | |
467 | switch (cmd) { | |
468 | case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */ | |
469 | return pty_set_lock(tty, (int __user *) arg); | |
84fd7bdf CG |
470 | case TIOCGPTLCK: /* Get PT Lock status */ |
471 | return pty_get_lock(tty, (int __user *)arg); | |
06026d91 CG |
472 | case TIOCPKT: /* Set PT packet mode */ |
473 | return pty_set_pktmode(tty, (int __user *)arg); | |
84fd7bdf CG |
474 | case TIOCGPKT: /* Get PT packet mode */ |
475 | return pty_get_pktmode(tty, (int __user *)arg); | |
26df6d13 | 476 | case TIOCSIG: /* Send signal to other side of pty */ |
477 | return pty_signal(tty, (int) arg); | |
ded2f295 JS |
478 | case TIOCGPTN: /* TTY returns ENOTTY, but glibc expects EINVAL here */ |
479 | return -EINVAL; | |
1da177e4 LT |
480 | } |
481 | return -ENOIOCTLCMD; | |
482 | } | |
483 | ||
dc8c8587 | 484 | static int legacy_count = CONFIG_LEGACY_PTY_COUNT; |
7154988f PG |
485 | /* |
486 | * not really modular, but the easiest way to keep compat with existing | |
487 | * bootargs behaviour is to continue using module_param here. | |
488 | */ | |
dc8c8587 KS |
489 | module_param(legacy_count, int, 0); |
490 | ||
342a5971 LT |
491 | /* |
492 | * The master side of a pty can do TIOCSPTLCK and thus | |
493 | * has pty_bsd_ioctl. | |
494 | */ | |
495 | static const struct tty_operations master_pty_ops_bsd = { | |
496 | .install = pty_install, | |
3e8e88ca AC |
497 | .open = pty_open, |
498 | .close = pty_close, | |
499 | .write = pty_write, | |
500 | .write_room = pty_write_room, | |
501 | .flush_buffer = pty_flush_buffer, | |
502 | .chars_in_buffer = pty_chars_in_buffer, | |
503 | .unthrottle = pty_unthrottle, | |
3e8e88ca | 504 | .ioctl = pty_bsd_ioctl, |
d03702a2 | 505 | .cleanup = pty_cleanup, |
d155255a AC |
506 | .resize = pty_resize, |
507 | .remove = pty_remove | |
3e8e88ca AC |
508 | }; |
509 | ||
342a5971 LT |
510 | static const struct tty_operations slave_pty_ops_bsd = { |
511 | .install = pty_install, | |
512 | .open = pty_open, | |
513 | .close = pty_close, | |
514 | .write = pty_write, | |
515 | .write_room = pty_write_room, | |
516 | .flush_buffer = pty_flush_buffer, | |
517 | .chars_in_buffer = pty_chars_in_buffer, | |
518 | .unthrottle = pty_unthrottle, | |
519 | .set_termios = pty_set_termios, | |
d03702a2 | 520 | .cleanup = pty_cleanup, |
d155255a | 521 | .resize = pty_resize, |
01adc807 PH |
522 | .start = pty_start, |
523 | .stop = pty_stop, | |
d155255a | 524 | .remove = pty_remove |
342a5971 LT |
525 | }; |
526 | ||
1da177e4 LT |
527 | static void __init legacy_pty_init(void) |
528 | { | |
342a5971 LT |
529 | struct tty_driver *pty_driver, *pty_slave_driver; |
530 | ||
dc8c8587 KS |
531 | if (legacy_count <= 0) |
532 | return; | |
1da177e4 | 533 | |
21aca2fa JS |
534 | pty_driver = tty_alloc_driver(legacy_count, |
535 | TTY_DRIVER_RESET_TERMIOS | | |
536 | TTY_DRIVER_REAL_RAW | | |
537 | TTY_DRIVER_DYNAMIC_ALLOC); | |
c3a6344a | 538 | if (IS_ERR(pty_driver)) |
1da177e4 LT |
539 | panic("Couldn't allocate pty driver"); |
540 | ||
21aca2fa JS |
541 | pty_slave_driver = tty_alloc_driver(legacy_count, |
542 | TTY_DRIVER_RESET_TERMIOS | | |
543 | TTY_DRIVER_REAL_RAW | | |
544 | TTY_DRIVER_DYNAMIC_ALLOC); | |
c3a6344a | 545 | if (IS_ERR(pty_slave_driver)) |
1da177e4 LT |
546 | panic("Couldn't allocate pty slave driver"); |
547 | ||
1da177e4 LT |
548 | pty_driver->driver_name = "pty_master"; |
549 | pty_driver->name = "pty"; | |
1da177e4 LT |
550 | pty_driver->major = PTY_MASTER_MAJOR; |
551 | pty_driver->minor_start = 0; | |
552 | pty_driver->type = TTY_DRIVER_TYPE_PTY; | |
553 | pty_driver->subtype = PTY_TYPE_MASTER; | |
554 | pty_driver->init_termios = tty_std_termios; | |
555 | pty_driver->init_termios.c_iflag = 0; | |
556 | pty_driver->init_termios.c_oflag = 0; | |
557 | pty_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
558 | pty_driver->init_termios.c_lflag = 0; | |
606d099c AC |
559 | pty_driver->init_termios.c_ispeed = 38400; |
560 | pty_driver->init_termios.c_ospeed = 38400; | |
1da177e4 | 561 | pty_driver->other = pty_slave_driver; |
342a5971 | 562 | tty_set_operations(pty_driver, &master_pty_ops_bsd); |
1da177e4 | 563 | |
1da177e4 LT |
564 | pty_slave_driver->driver_name = "pty_slave"; |
565 | pty_slave_driver->name = "ttyp"; | |
1da177e4 LT |
566 | pty_slave_driver->major = PTY_SLAVE_MAJOR; |
567 | pty_slave_driver->minor_start = 0; | |
568 | pty_slave_driver->type = TTY_DRIVER_TYPE_PTY; | |
569 | pty_slave_driver->subtype = PTY_TYPE_SLAVE; | |
570 | pty_slave_driver->init_termios = tty_std_termios; | |
571 | pty_slave_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
606d099c AC |
572 | pty_slave_driver->init_termios.c_ispeed = 38400; |
573 | pty_slave_driver->init_termios.c_ospeed = 38400; | |
1da177e4 | 574 | pty_slave_driver->other = pty_driver; |
342a5971 | 575 | tty_set_operations(pty_slave_driver, &slave_pty_ops_bsd); |
1da177e4 LT |
576 | |
577 | if (tty_register_driver(pty_driver)) | |
578 | panic("Couldn't register pty driver"); | |
579 | if (tty_register_driver(pty_slave_driver)) | |
580 | panic("Couldn't register pty slave driver"); | |
581 | } | |
582 | #else | |
583 | static inline void legacy_pty_init(void) { } | |
584 | #endif | |
585 | ||
586 | /* Unix98 devices */ | |
587 | #ifdef CONFIG_UNIX98_PTYS | |
1da177e4 | 588 | |
d81ed103 AC |
589 | static struct cdev ptmx_cdev; |
590 | ||
6caa76b7 | 591 | static int pty_unix98_ioctl(struct tty_struct *tty, |
1da177e4 LT |
592 | unsigned int cmd, unsigned long arg) |
593 | { | |
594 | switch (cmd) { | |
595 | case TIOCSPTLCK: /* Set PT Lock (disallow slave open) */ | |
596 | return pty_set_lock(tty, (int __user *)arg); | |
84fd7bdf CG |
597 | case TIOCGPTLCK: /* Get PT Lock status */ |
598 | return pty_get_lock(tty, (int __user *)arg); | |
06026d91 CG |
599 | case TIOCPKT: /* Set PT packet mode */ |
600 | return pty_set_pktmode(tty, (int __user *)arg); | |
84fd7bdf CG |
601 | case TIOCGPKT: /* Get PT packet mode */ |
602 | return pty_get_pktmode(tty, (int __user *)arg); | |
1da177e4 LT |
603 | case TIOCGPTN: /* Get PT Number */ |
604 | return put_user(tty->index, (unsigned int __user *)arg); | |
26df6d13 | 605 | case TIOCSIG: /* Send signal to other side of pty */ |
606 | return pty_signal(tty, (int) arg); | |
1da177e4 LT |
607 | } |
608 | ||
609 | return -ENOIOCTLCMD; | |
610 | } | |
611 | ||
99f1fe18 AC |
612 | /** |
613 | * ptm_unix98_lookup - find a pty master | |
614 | * @driver: ptm driver | |
615 | * @idx: tty index | |
616 | * | |
617 | * Look up a pty master device. Called under the tty_mutex for now. | |
618 | * This provides our locking. | |
619 | */ | |
620 | ||
15f1a633 | 621 | static struct tty_struct *ptm_unix98_lookup(struct tty_driver *driver, |
8ead9dd5 | 622 | struct file *file, int idx) |
99f1fe18 | 623 | { |
593a27c4 KK |
624 | /* Master must be open via /dev/ptmx */ |
625 | return ERR_PTR(-EIO); | |
99f1fe18 AC |
626 | } |
627 | ||
628 | /** | |
629 | * pts_unix98_lookup - find a pty slave | |
630 | * @driver: pts driver | |
631 | * @idx: tty index | |
632 | * | |
633 | * Look up a pty master device. Called under the tty_mutex for now. | |
d739e65b | 634 | * This provides our locking for the tty pointer. |
99f1fe18 AC |
635 | */ |
636 | ||
15f1a633 | 637 | static struct tty_struct *pts_unix98_lookup(struct tty_driver *driver, |
8ead9dd5 | 638 | struct file *file, int idx) |
99f1fe18 | 639 | { |
d739e65b AC |
640 | struct tty_struct *tty; |
641 | ||
642 | mutex_lock(&devpts_mutex); | |
8ead9dd5 | 643 | tty = devpts_get_priv(file->f_path.dentry); |
d739e65b | 644 | mutex_unlock(&devpts_mutex); |
99f1fe18 AC |
645 | /* Master must be open before slave */ |
646 | if (!tty) | |
647 | return ERR_PTR(-EIO); | |
648 | return tty; | |
649 | } | |
650 | ||
bf970ee4 | 651 | static int pty_unix98_install(struct tty_driver *driver, struct tty_struct *tty) |
8b0a88d5 | 652 | { |
5d249bc6 | 653 | return pty_common_install(driver, tty, false); |
8b0a88d5 AC |
654 | } |
655 | ||
f4b208eb | 656 | /* this is called once with whichever end is closed last */ |
c1e33af1 | 657 | static void pty_unix98_remove(struct tty_driver *driver, struct tty_struct *tty) |
f4b208eb | 658 | { |
67245ff3 | 659 | struct pts_fs_info *fsi; |
2831c89f HK |
660 | |
661 | if (tty->driver->subtype == PTY_TYPE_MASTER) | |
67245ff3 | 662 | fsi = tty->driver_data; |
2831c89f | 663 | else |
67245ff3 | 664 | fsi = tty->link->driver_data; |
5353ed8d CIK |
665 | |
666 | if (fsi) { | |
667 | devpts_kill_index(fsi, tty->index); | |
668 | devpts_release(fsi); | |
669 | } | |
f4b208eb JS |
670 | } |
671 | ||
feebed65 | 672 | static const struct tty_operations ptm_unix98_ops = { |
99f1fe18 | 673 | .lookup = ptm_unix98_lookup, |
bf970ee4 | 674 | .install = pty_unix98_install, |
7171604a | 675 | .remove = pty_unix98_remove, |
3e8e88ca AC |
676 | .open = pty_open, |
677 | .close = pty_close, | |
678 | .write = pty_write, | |
679 | .write_room = pty_write_room, | |
680 | .flush_buffer = pty_flush_buffer, | |
681 | .chars_in_buffer = pty_chars_in_buffer, | |
682 | .unthrottle = pty_unthrottle, | |
feebed65 | 683 | .ioctl = pty_unix98_ioctl, |
36b3c070 AC |
684 | .resize = pty_resize, |
685 | .cleanup = pty_cleanup | |
3e8e88ca AC |
686 | }; |
687 | ||
99f1fe18 AC |
688 | static const struct tty_operations pty_unix98_ops = { |
689 | .lookup = pts_unix98_lookup, | |
bf970ee4 | 690 | .install = pty_unix98_install, |
7171604a | 691 | .remove = pty_unix98_remove, |
99f1fe18 AC |
692 | .open = pty_open, |
693 | .close = pty_close, | |
694 | .write = pty_write, | |
695 | .write_room = pty_write_room, | |
696 | .flush_buffer = pty_flush_buffer, | |
697 | .chars_in_buffer = pty_chars_in_buffer, | |
698 | .unthrottle = pty_unthrottle, | |
699 | .set_termios = pty_set_termios, | |
01adc807 PH |
700 | .start = pty_start, |
701 | .stop = pty_stop, | |
d03702a2 | 702 | .cleanup = pty_cleanup, |
99f1fe18 | 703 | }; |
d81ed103 AC |
704 | |
705 | /** | |
706 | * ptmx_open - open a unix 98 pty master | |
707 | * @inode: inode of device file | |
708 | * @filp: file pointer to tty | |
709 | * | |
710 | * Allocate a unix98 pty master device from the ptmx driver. | |
711 | * | |
712 | * Locking: tty_mutex protects the init_dev work. tty->count should | |
b9f8033f | 713 | * protect the rest. |
d81ed103 AC |
714 | * allocated_ptys_lock handles the list of free pty numbers |
715 | */ | |
716 | ||
64ba3dc3 | 717 | static int ptmx_open(struct inode *inode, struct file *filp) |
d81ed103 | 718 | { |
67245ff3 | 719 | struct pts_fs_info *fsi; |
d81ed103 | 720 | struct tty_struct *tty; |
8ead9dd5 | 721 | struct dentry *dentry; |
d81ed103 AC |
722 | int retval; |
723 | int index; | |
724 | ||
725 | nonseekable_open(inode, filp); | |
726 | ||
b0b88565 LT |
727 | /* We refuse fsnotify events on ptmx, since it's a shared resource */ |
728 | filp->f_mode |= FMODE_NONOTIFY; | |
729 | ||
fa90e1c9 JS |
730 | retval = tty_alloc_file(filp); |
731 | if (retval) | |
732 | return retval; | |
733 | ||
eedf265a EB |
734 | fsi = devpts_acquire(filp); |
735 | if (IS_ERR(fsi)) { | |
736 | retval = PTR_ERR(fsi); | |
67245ff3 | 737 | goto out_free_file; |
eedf265a | 738 | } |
67245ff3 | 739 | |
d81ed103 | 740 | /* find a device that is not in use. */ |
89c8d91e | 741 | mutex_lock(&devpts_mutex); |
67245ff3 | 742 | index = devpts_new_index(fsi); |
89c8d91e AC |
743 | mutex_unlock(&devpts_mutex); |
744 | ||
67245ff3 LT |
745 | retval = index; |
746 | if (index < 0) | |
eedf265a | 747 | goto out_put_fsi; |
d81ed103 | 748 | |
d81ed103 | 749 | |
67245ff3 LT |
750 | mutex_lock(&tty_mutex); |
751 | tty = tty_init_dev(ptm_driver, index); | |
89c8d91e AC |
752 | /* The tty returned here is locked so we can safely |
753 | drop the mutex */ | |
754 | mutex_unlock(&tty_mutex); | |
755 | ||
67245ff3 LT |
756 | retval = PTR_ERR(tty); |
757 | if (IS_ERR(tty)) | |
758 | goto out; | |
ee2ffa0d | 759 | |
2831c89f | 760 | /* |
67245ff3 LT |
761 | * From here on out, the tty is "live", and the index and |
762 | * fsi will be killed/put by the tty_release() | |
2831c89f | 763 | */ |
67245ff3 LT |
764 | set_bit(TTY_PTY_LOCK, &tty->flags); /* LOCK THE SLAVE */ |
765 | tty->driver_data = fsi; | |
2831c89f | 766 | |
fa90e1c9 | 767 | tty_add_file(tty, filp); |
d81ed103 | 768 | |
8ead9dd5 LT |
769 | dentry = devpts_pty_new(fsi, index, tty->link); |
770 | if (IS_ERR(dentry)) { | |
771 | retval = PTR_ERR(dentry); | |
1177c0ef | 772 | goto err_release; |
162b97cf | 773 | } |
8ead9dd5 | 774 | tty->link->driver_data = dentry; |
d81ed103 AC |
775 | |
776 | retval = ptm_driver->ops->open(tty, filp); | |
64ba3dc3 | 777 | if (retval) |
1177c0ef JS |
778 | goto err_release; |
779 | ||
d435cefe | 780 | tty_debug_hangup(tty, "opening (count=%d)\n", tty->count); |
d6847793 | 781 | |
89c8d91e | 782 | tty_unlock(tty); |
1177c0ef JS |
783 | return 0; |
784 | err_release: | |
89c8d91e | 785 | tty_unlock(tty); |
67245ff3 | 786 | // This will also put-ref the fsi |
eeb89d91 | 787 | tty_release(inode, filp); |
d81ed103 AC |
788 | return retval; |
789 | out: | |
67245ff3 | 790 | devpts_kill_index(fsi, index); |
eedf265a EB |
791 | out_put_fsi: |
792 | devpts_release(fsi); | |
67245ff3 | 793 | out_free_file: |
fa90e1c9 | 794 | tty_free_file(filp); |
64ba3dc3 | 795 | return retval; |
d81ed103 AC |
796 | } |
797 | ||
d2ec3f77 | 798 | static struct file_operations ptmx_fops __ro_after_init; |
d81ed103 | 799 | |
1da177e4 LT |
800 | static void __init unix98_pty_init(void) |
801 | { | |
21aca2fa JS |
802 | ptm_driver = tty_alloc_driver(NR_UNIX98_PTY_MAX, |
803 | TTY_DRIVER_RESET_TERMIOS | | |
804 | TTY_DRIVER_REAL_RAW | | |
805 | TTY_DRIVER_DYNAMIC_DEV | | |
806 | TTY_DRIVER_DEVPTS_MEM | | |
807 | TTY_DRIVER_DYNAMIC_ALLOC); | |
c3a6344a | 808 | if (IS_ERR(ptm_driver)) |
1da177e4 | 809 | panic("Couldn't allocate Unix98 ptm driver"); |
21aca2fa JS |
810 | pts_driver = tty_alloc_driver(NR_UNIX98_PTY_MAX, |
811 | TTY_DRIVER_RESET_TERMIOS | | |
812 | TTY_DRIVER_REAL_RAW | | |
813 | TTY_DRIVER_DYNAMIC_DEV | | |
814 | TTY_DRIVER_DEVPTS_MEM | | |
815 | TTY_DRIVER_DYNAMIC_ALLOC); | |
c3a6344a | 816 | if (IS_ERR(pts_driver)) |
1da177e4 LT |
817 | panic("Couldn't allocate Unix98 pts driver"); |
818 | ||
1da177e4 LT |
819 | ptm_driver->driver_name = "pty_master"; |
820 | ptm_driver->name = "ptm"; | |
821 | ptm_driver->major = UNIX98_PTY_MASTER_MAJOR; | |
822 | ptm_driver->minor_start = 0; | |
823 | ptm_driver->type = TTY_DRIVER_TYPE_PTY; | |
824 | ptm_driver->subtype = PTY_TYPE_MASTER; | |
825 | ptm_driver->init_termios = tty_std_termios; | |
826 | ptm_driver->init_termios.c_iflag = 0; | |
827 | ptm_driver->init_termios.c_oflag = 0; | |
828 | ptm_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
829 | ptm_driver->init_termios.c_lflag = 0; | |
606d099c AC |
830 | ptm_driver->init_termios.c_ispeed = 38400; |
831 | ptm_driver->init_termios.c_ospeed = 38400; | |
1da177e4 | 832 | ptm_driver->other = pts_driver; |
feebed65 | 833 | tty_set_operations(ptm_driver, &ptm_unix98_ops); |
1da177e4 | 834 | |
1da177e4 LT |
835 | pts_driver->driver_name = "pty_slave"; |
836 | pts_driver->name = "pts"; | |
837 | pts_driver->major = UNIX98_PTY_SLAVE_MAJOR; | |
838 | pts_driver->minor_start = 0; | |
839 | pts_driver->type = TTY_DRIVER_TYPE_PTY; | |
840 | pts_driver->subtype = PTY_TYPE_SLAVE; | |
841 | pts_driver->init_termios = tty_std_termios; | |
842 | pts_driver->init_termios.c_cflag = B38400 | CS8 | CREAD; | |
606d099c AC |
843 | pts_driver->init_termios.c_ispeed = 38400; |
844 | pts_driver->init_termios.c_ospeed = 38400; | |
1da177e4 | 845 | pts_driver->other = ptm_driver; |
99f1fe18 | 846 | tty_set_operations(pts_driver, &pty_unix98_ops); |
fe9cd962 | 847 | |
1da177e4 LT |
848 | if (tty_register_driver(ptm_driver)) |
849 | panic("Couldn't register Unix98 ptm driver"); | |
850 | if (tty_register_driver(pts_driver)) | |
851 | panic("Couldn't register Unix98 pts driver"); | |
852 | ||
d81ed103 AC |
853 | /* Now create the /dev/ptmx special device */ |
854 | tty_default_fops(&ptmx_fops); | |
855 | ptmx_fops.open = ptmx_open; | |
856 | ||
857 | cdev_init(&ptmx_cdev, &ptmx_fops); | |
858 | if (cdev_add(&ptmx_cdev, MKDEV(TTYAUX_MAJOR, 2), 1) || | |
859 | register_chrdev_region(MKDEV(TTYAUX_MAJOR, 2), 1, "/dev/ptmx") < 0) | |
82f8c35f | 860 | panic("Couldn't register /dev/ptmx driver"); |
d81ed103 | 861 | device_create(tty_class, NULL, MKDEV(TTYAUX_MAJOR, 2), NULL, "ptmx"); |
1da177e4 | 862 | } |
d81ed103 | 863 | |
1da177e4 LT |
864 | #else |
865 | static inline void unix98_pty_init(void) { } | |
866 | #endif | |
867 | ||
868 | static int __init pty_init(void) | |
869 | { | |
870 | legacy_pty_init(); | |
871 | unix98_pty_init(); | |
872 | return 0; | |
873 | } | |
7154988f | 874 | device_initcall(pty_init); |