// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
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*
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* Modified by Fred N. van Kempen, 01/29/93, to add line disciplines
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* which can be dynamically activated and de-activated by the line
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* discipline handling modules (like SLIP).
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*/
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#include <linux/types.h>
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#include <linux/termios.h>
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#include <linux/errno.h>
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#include <linux/sched/signal.h>
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#include <linux/kernel.h>
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#include <linux/major.h>
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#include <linux/tty.h>
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#include <linux/fcntl.h>
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#include <linux/string.h>
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#include <linux/mm.h>
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#include <linux/module.h>
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#include <linux/bitops.h>
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#include <linux/mutex.h>
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#include <linux/compat.h>
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#include "tty.h"
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#include <asm/io.h>
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#include <linux/uaccess.h>
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#undef TTY_DEBUG_WAIT_UNTIL_SENT
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#ifdef TTY_DEBUG_WAIT_UNTIL_SENT
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# define tty_debug_wait_until_sent(tty, f, args...) tty_debug(tty, f, ##args)
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#else
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# define tty_debug_wait_until_sent(tty, f, args...) do {} while (0)
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#endif
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#undef DEBUG
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/*
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* Internal flag options for termios setting behavior
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*/
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#define TERMIOS_FLUSH 1
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#define TERMIOS_WAIT 2
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#define TERMIOS_TERMIO 4
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#define TERMIOS_OLD 8
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|
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/**
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* tty_chars_in_buffer - characters pending
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* @tty: terminal
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*
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* Return the number of bytes of data in the device private
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* output queue. If no private method is supplied there is assumed
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* to be no queue on the device.
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*/
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int tty_chars_in_buffer(struct tty_struct *tty)
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{
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if (tty->ops->chars_in_buffer)
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return tty->ops->chars_in_buffer(tty);
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else
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return 0;
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}
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EXPORT_SYMBOL(tty_chars_in_buffer);
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/**
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* tty_write_room - write queue space
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* @tty: terminal
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*
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* Return the number of bytes that can be queued to this device
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* at the present time. The result should be treated as a guarantee
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* and the driver cannot offer a value it later shrinks by more than
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* the number of bytes written. If no method is provided 2K is always
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* returned and data may be lost as there will be no flow control.
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*/
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int tty_write_room(struct tty_struct *tty)
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{
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if (tty->ops->write_room)
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return tty->ops->write_room(tty);
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return 2048;
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}
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EXPORT_SYMBOL(tty_write_room);
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/**
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* tty_driver_flush_buffer - discard internal buffer
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* @tty: terminal
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*
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* Discard the internal output buffer for this device. If no method
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* is provided then either the buffer cannot be hardware flushed or
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* there is no buffer driver side.
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*/
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void tty_driver_flush_buffer(struct tty_struct *tty)
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{
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if (tty->ops->flush_buffer)
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tty->ops->flush_buffer(tty);
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}
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EXPORT_SYMBOL(tty_driver_flush_buffer);
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/**
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* tty_throttle - flow control
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* @tty: terminal
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*
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* Indicate that a tty should stop transmitting data down the stack.
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* Takes the termios rwsem to protect against parallel throttle/unthrottle
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* and also to ensure the driver can consistently reference its own
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* termios data at this point when implementing software flow control.
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*/
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void tty_throttle(struct tty_struct *tty)
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{
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down_write(&tty->termios_rwsem);
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/* check TTY_THROTTLED first so it indicates our state */
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if (!test_and_set_bit(TTY_THROTTLED, &tty->flags) &&
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tty->ops->throttle)
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tty->ops->throttle(tty);
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tty->flow_change = 0;
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up_write(&tty->termios_rwsem);
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}
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EXPORT_SYMBOL(tty_throttle);
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/**
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* tty_unthrottle - flow control
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* @tty: terminal
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*
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* Indicate that a tty may continue transmitting data down the stack.
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* Takes the termios rwsem to protect against parallel throttle/unthrottle
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* and also to ensure the driver can consistently reference its own
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* termios data at this point when implementing software flow control.
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*
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* Drivers should however remember that the stack can issue a throttle,
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* then change flow control method, then unthrottle.
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*/
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|
void tty_unthrottle(struct tty_struct *tty)
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{
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down_write(&tty->termios_rwsem);
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if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) &&
|
tty->ops->unthrottle)
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tty->ops->unthrottle(tty);
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tty->flow_change = 0;
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up_write(&tty->termios_rwsem);
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}
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EXPORT_SYMBOL(tty_unthrottle);
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|
/**
|
* tty_throttle_safe - flow control
|
* @tty: terminal
|
*
|
* Similar to tty_throttle() but will only attempt throttle
|
* if tty->flow_change is TTY_THROTTLE_SAFE. Prevents an accidental
|
* throttle due to race conditions when throttling is conditional
|
* on factors evaluated prior to throttling.
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*
|
* Returns 0 if tty is throttled (or was already throttled)
|
*/
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int tty_throttle_safe(struct tty_struct *tty)
|
{
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int ret = 0;
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|
mutex_lock(&tty->throttle_mutex);
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if (!tty_throttled(tty)) {
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if (tty->flow_change != TTY_THROTTLE_SAFE)
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ret = 1;
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else {
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set_bit(TTY_THROTTLED, &tty->flags);
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if (tty->ops->throttle)
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tty->ops->throttle(tty);
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}
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}
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mutex_unlock(&tty->throttle_mutex);
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|
return ret;
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}
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/**
|
* tty_unthrottle_safe - flow control
|
* @tty: terminal
|
*
|
* Similar to tty_unthrottle() but will only attempt unthrottle
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* if tty->flow_change is TTY_UNTHROTTLE_SAFE. Prevents an accidental
|
* unthrottle due to race conditions when unthrottling is conditional
|
* on factors evaluated prior to unthrottling.
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*
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* Returns 0 if tty is unthrottled (or was already unthrottled)
|
*/
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|
int tty_unthrottle_safe(struct tty_struct *tty)
|
{
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int ret = 0;
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|
mutex_lock(&tty->throttle_mutex);
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if (tty_throttled(tty)) {
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if (tty->flow_change != TTY_UNTHROTTLE_SAFE)
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ret = 1;
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else {
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clear_bit(TTY_THROTTLED, &tty->flags);
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if (tty->ops->unthrottle)
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tty->ops->unthrottle(tty);
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}
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}
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mutex_unlock(&tty->throttle_mutex);
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return ret;
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}
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/**
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* tty_wait_until_sent - wait for I/O to finish
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* @tty: tty we are waiting for
|
* @timeout: how long we will wait
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*
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* Wait for characters pending in a tty driver to hit the wire, or
|
* for a timeout to occur (eg due to flow control)
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*
|
* Locking: none
|
*/
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void tty_wait_until_sent(struct tty_struct *tty, long timeout)
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{
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tty_debug_wait_until_sent(tty, "wait until sent, timeout=%ld\n", timeout);
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if (!timeout)
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timeout = MAX_SCHEDULE_TIMEOUT;
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|
timeout = wait_event_interruptible_timeout(tty->write_wait,
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!tty_chars_in_buffer(tty), timeout);
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if (timeout <= 0)
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return;
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if (timeout == MAX_SCHEDULE_TIMEOUT)
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timeout = 0;
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if (tty->ops->wait_until_sent)
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tty->ops->wait_until_sent(tty, timeout);
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}
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EXPORT_SYMBOL(tty_wait_until_sent);
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|
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/*
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* Termios Helper Methods
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*/
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static void unset_locked_termios(struct tty_struct *tty, struct ktermios *old)
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{
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struct ktermios *termios = &tty->termios;
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struct ktermios *locked = &tty->termios_locked;
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int i;
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|
#define NOSET_MASK(x, y, z) (x = ((x) & ~(z)) | ((y) & (z)))
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|
NOSET_MASK(termios->c_iflag, old->c_iflag, locked->c_iflag);
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NOSET_MASK(termios->c_oflag, old->c_oflag, locked->c_oflag);
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NOSET_MASK(termios->c_cflag, old->c_cflag, locked->c_cflag);
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NOSET_MASK(termios->c_lflag, old->c_lflag, locked->c_lflag);
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termios->c_line = locked->c_line ? old->c_line : termios->c_line;
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for (i = 0; i < NCCS; i++)
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termios->c_cc[i] = locked->c_cc[i] ?
|
old->c_cc[i] : termios->c_cc[i];
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/* FIXME: What should we do for i/ospeed */
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}
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/**
|
* tty_termios_copy_hw - copy hardware settings
|
* @new: New termios
|
* @old: Old termios
|
*
|
* Propagate the hardware specific terminal setting bits from
|
* the old termios structure to the new one. This is used in cases
|
* where the hardware does not support reconfiguration or as a helper
|
* in some cases where only minimal reconfiguration is supported
|
*/
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|
void tty_termios_copy_hw(struct ktermios *new, struct ktermios *old)
|
{
|
/* The bits a dumb device handles in software. Smart devices need
|
to always provide a set_termios method */
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new->c_cflag &= HUPCL | CREAD | CLOCAL;
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new->c_cflag |= old->c_cflag & ~(HUPCL | CREAD | CLOCAL);
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new->c_ispeed = old->c_ispeed;
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new->c_ospeed = old->c_ospeed;
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}
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EXPORT_SYMBOL(tty_termios_copy_hw);
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/**
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* tty_termios_hw_change - check for setting change
|
* @a: termios
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* @b: termios to compare
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*
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* Check if any of the bits that affect a dumb device have changed
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* between the two termios structures, or a speed change is needed.
|
*/
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int tty_termios_hw_change(const struct ktermios *a, const struct ktermios *b)
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{
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if (a->c_ispeed != b->c_ispeed || a->c_ospeed != b->c_ospeed)
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return 1;
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if ((a->c_cflag ^ b->c_cflag) & ~(HUPCL | CREAD | CLOCAL))
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return 1;
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return 0;
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}
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EXPORT_SYMBOL(tty_termios_hw_change);
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/**
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* tty_set_termios - update termios values
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* @tty: tty to update
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* @new_termios: desired new value
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*
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* Perform updates to the termios values set on this terminal.
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* A master pty's termios should never be set.
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*
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* Locking: termios_rwsem
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*/
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int tty_set_termios(struct tty_struct *tty, struct ktermios *new_termios)
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{
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struct ktermios old_termios;
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struct tty_ldisc *ld;
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WARN_ON(tty->driver->type == TTY_DRIVER_TYPE_PTY &&
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tty->driver->subtype == PTY_TYPE_MASTER);
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/*
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* Perform the actual termios internal changes under lock.
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*/
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|
|
/* FIXME: we need to decide on some locking/ordering semantics
|
for the set_termios notification eventually */
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down_write(&tty->termios_rwsem);
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old_termios = tty->termios;
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tty->termios = *new_termios;
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unset_locked_termios(tty, &old_termios);
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if (tty->ops->set_termios)
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tty->ops->set_termios(tty, &old_termios);
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else
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tty_termios_copy_hw(&tty->termios, &old_termios);
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ld = tty_ldisc_ref(tty);
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if (ld != NULL) {
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if (ld->ops->set_termios)
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ld->ops->set_termios(tty, &old_termios);
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tty_ldisc_deref(ld);
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}
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up_write(&tty->termios_rwsem);
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return 0;
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}
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EXPORT_SYMBOL_GPL(tty_set_termios);
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/**
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* set_termios - set termios values for a tty
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* @tty: terminal device
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* @arg: user data
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* @opt: option information
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*
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* Helper function to prepare termios data and run necessary other
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* functions before using tty_set_termios to do the actual changes.
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*
|
* Locking:
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* Called functions take ldisc and termios_rwsem locks
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*/
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static int set_termios(struct tty_struct *tty, void __user *arg, int opt)
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{
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struct ktermios tmp_termios;
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struct tty_ldisc *ld;
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int retval = tty_check_change(tty);
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if (retval)
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return retval;
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down_read(&tty->termios_rwsem);
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tmp_termios = tty->termios;
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up_read(&tty->termios_rwsem);
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if (opt & TERMIOS_TERMIO) {
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if (user_termio_to_kernel_termios(&tmp_termios,
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(struct termio __user *)arg))
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return -EFAULT;
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#ifdef TCGETS2
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} else if (opt & TERMIOS_OLD) {
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if (user_termios_to_kernel_termios_1(&tmp_termios,
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(struct termios __user *)arg))
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return -EFAULT;
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} else {
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if (user_termios_to_kernel_termios(&tmp_termios,
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(struct termios2 __user *)arg))
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return -EFAULT;
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}
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#else
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} else if (user_termios_to_kernel_termios(&tmp_termios,
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(struct termios __user *)arg))
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return -EFAULT;
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#endif
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/* If old style Bfoo values are used then load c_ispeed/c_ospeed
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* with the real speed so its unconditionally usable */
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tmp_termios.c_ispeed = tty_termios_input_baud_rate(&tmp_termios);
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tmp_termios.c_ospeed = tty_termios_baud_rate(&tmp_termios);
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if (opt & (TERMIOS_FLUSH|TERMIOS_WAIT)) {
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retry_write_wait:
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retval = wait_event_interruptible(tty->write_wait, !tty_chars_in_buffer(tty));
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if (retval < 0)
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return retval;
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if (tty_write_lock(tty, 0) < 0)
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goto retry_write_wait;
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/* Racing writer? */
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if (tty_chars_in_buffer(tty)) {
|
tty_write_unlock(tty);
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goto retry_write_wait;
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}
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ld = tty_ldisc_ref(tty);
|
if (ld != NULL) {
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if ((opt & TERMIOS_FLUSH) && ld->ops->flush_buffer)
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ld->ops->flush_buffer(tty);
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tty_ldisc_deref(ld);
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}
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if ((opt & TERMIOS_WAIT) && tty->ops->wait_until_sent) {
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tty->ops->wait_until_sent(tty, 0);
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if (signal_pending(current)) {
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tty_write_unlock(tty);
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return -ERESTARTSYS;
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}
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}
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tty_set_termios(tty, &tmp_termios);
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tty_write_unlock(tty);
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} else {
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tty_set_termios(tty, &tmp_termios);
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}
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|
/* FIXME: Arguably if tmp_termios == tty->termios AND the
|
actual requested termios was not tmp_termios then we may
|
want to return an error as no user requested change has
|
succeeded */
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return 0;
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}
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static void copy_termios(struct tty_struct *tty, struct ktermios *kterm)
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{
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down_read(&tty->termios_rwsem);
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*kterm = tty->termios;
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up_read(&tty->termios_rwsem);
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}
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static void copy_termios_locked(struct tty_struct *tty, struct ktermios *kterm)
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{
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down_read(&tty->termios_rwsem);
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*kterm = tty->termios_locked;
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up_read(&tty->termios_rwsem);
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}
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static int get_termio(struct tty_struct *tty, struct termio __user *termio)
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{
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struct ktermios kterm;
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copy_termios(tty, &kterm);
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if (kernel_termios_to_user_termio(termio, &kterm))
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return -EFAULT;
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return 0;
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}
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|
#ifdef TIOCGETP
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/*
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* These are deprecated, but there is limited support..
|
*
|
* The "sg_flags" translation is a joke..
|
*/
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static int get_sgflags(struct tty_struct *tty)
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{
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int flags = 0;
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|
if (!L_ICANON(tty)) {
|
if (L_ISIG(tty))
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flags |= 0x02; /* cbreak */
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else
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flags |= 0x20; /* raw */
|
}
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if (L_ECHO(tty))
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flags |= 0x08; /* echo */
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if (O_OPOST(tty))
|
if (O_ONLCR(tty))
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flags |= 0x10; /* crmod */
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return flags;
|
}
|
|
static int get_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
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{
|
struct sgttyb tmp;
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|
down_read(&tty->termios_rwsem);
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tmp.sg_ispeed = tty->termios.c_ispeed;
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tmp.sg_ospeed = tty->termios.c_ospeed;
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tmp.sg_erase = tty->termios.c_cc[VERASE];
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tmp.sg_kill = tty->termios.c_cc[VKILL];
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tmp.sg_flags = get_sgflags(tty);
|
up_read(&tty->termios_rwsem);
|
|
return copy_to_user(sgttyb, &tmp, sizeof(tmp)) ? -EFAULT : 0;
|
}
|
|
static void set_sgflags(struct ktermios *termios, int flags)
|
{
|
termios->c_iflag = ICRNL | IXON;
|
termios->c_oflag = 0;
|
termios->c_lflag = ISIG | ICANON;
|
if (flags & 0x02) { /* cbreak */
|
termios->c_iflag = 0;
|
termios->c_lflag &= ~ICANON;
|
}
|
if (flags & 0x08) { /* echo */
|
termios->c_lflag |= ECHO | ECHOE | ECHOK |
|
ECHOCTL | ECHOKE | IEXTEN;
|
}
|
if (flags & 0x10) { /* crmod */
|
termios->c_oflag |= OPOST | ONLCR;
|
}
|
if (flags & 0x20) { /* raw */
|
termios->c_iflag = 0;
|
termios->c_lflag &= ~(ISIG | ICANON);
|
}
|
if (!(termios->c_lflag & ICANON)) {
|
termios->c_cc[VMIN] = 1;
|
termios->c_cc[VTIME] = 0;
|
}
|
}
|
|
/**
|
* set_sgttyb - set legacy terminal values
|
* @tty: tty structure
|
* @sgttyb: pointer to old style terminal structure
|
*
|
* Updates a terminal from the legacy BSD style terminal information
|
* structure.
|
*
|
* Locking: termios_rwsem
|
*/
|
|
static int set_sgttyb(struct tty_struct *tty, struct sgttyb __user *sgttyb)
|
{
|
int retval;
|
struct sgttyb tmp;
|
struct ktermios termios;
|
|
retval = tty_check_change(tty);
|
if (retval)
|
return retval;
|
|
if (copy_from_user(&tmp, sgttyb, sizeof(tmp)))
|
return -EFAULT;
|
|
down_write(&tty->termios_rwsem);
|
termios = tty->termios;
|
termios.c_cc[VERASE] = tmp.sg_erase;
|
termios.c_cc[VKILL] = tmp.sg_kill;
|
set_sgflags(&termios, tmp.sg_flags);
|
/* Try and encode into Bfoo format */
|
#ifdef BOTHER
|
tty_termios_encode_baud_rate(&termios, termios.c_ispeed,
|
termios.c_ospeed);
|
#endif
|
up_write(&tty->termios_rwsem);
|
tty_set_termios(tty, &termios);
|
return 0;
|
}
|
#endif
|
|
#ifdef TIOCGETC
|
static int get_tchars(struct tty_struct *tty, struct tchars __user *tchars)
|
{
|
struct tchars tmp;
|
|
down_read(&tty->termios_rwsem);
|
tmp.t_intrc = tty->termios.c_cc[VINTR];
|
tmp.t_quitc = tty->termios.c_cc[VQUIT];
|
tmp.t_startc = tty->termios.c_cc[VSTART];
|
tmp.t_stopc = tty->termios.c_cc[VSTOP];
|
tmp.t_eofc = tty->termios.c_cc[VEOF];
|
tmp.t_brkc = tty->termios.c_cc[VEOL2]; /* what is brkc anyway? */
|
up_read(&tty->termios_rwsem);
|
return copy_to_user(tchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
|
}
|
|
static int set_tchars(struct tty_struct *tty, struct tchars __user *tchars)
|
{
|
struct tchars tmp;
|
|
if (copy_from_user(&tmp, tchars, sizeof(tmp)))
|
return -EFAULT;
|
down_write(&tty->termios_rwsem);
|
tty->termios.c_cc[VINTR] = tmp.t_intrc;
|
tty->termios.c_cc[VQUIT] = tmp.t_quitc;
|
tty->termios.c_cc[VSTART] = tmp.t_startc;
|
tty->termios.c_cc[VSTOP] = tmp.t_stopc;
|
tty->termios.c_cc[VEOF] = tmp.t_eofc;
|
tty->termios.c_cc[VEOL2] = tmp.t_brkc; /* what is brkc anyway? */
|
up_write(&tty->termios_rwsem);
|
return 0;
|
}
|
#endif
|
|
#ifdef TIOCGLTC
|
static int get_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
|
{
|
struct ltchars tmp;
|
|
down_read(&tty->termios_rwsem);
|
tmp.t_suspc = tty->termios.c_cc[VSUSP];
|
/* what is dsuspc anyway? */
|
tmp.t_dsuspc = tty->termios.c_cc[VSUSP];
|
tmp.t_rprntc = tty->termios.c_cc[VREPRINT];
|
/* what is flushc anyway? */
|
tmp.t_flushc = tty->termios.c_cc[VEOL2];
|
tmp.t_werasc = tty->termios.c_cc[VWERASE];
|
tmp.t_lnextc = tty->termios.c_cc[VLNEXT];
|
up_read(&tty->termios_rwsem);
|
return copy_to_user(ltchars, &tmp, sizeof(tmp)) ? -EFAULT : 0;
|
}
|
|
static int set_ltchars(struct tty_struct *tty, struct ltchars __user *ltchars)
|
{
|
struct ltchars tmp;
|
|
if (copy_from_user(&tmp, ltchars, sizeof(tmp)))
|
return -EFAULT;
|
|
down_write(&tty->termios_rwsem);
|
tty->termios.c_cc[VSUSP] = tmp.t_suspc;
|
/* what is dsuspc anyway? */
|
tty->termios.c_cc[VEOL2] = tmp.t_dsuspc;
|
tty->termios.c_cc[VREPRINT] = tmp.t_rprntc;
|
/* what is flushc anyway? */
|
tty->termios.c_cc[VEOL2] = tmp.t_flushc;
|
tty->termios.c_cc[VWERASE] = tmp.t_werasc;
|
tty->termios.c_cc[VLNEXT] = tmp.t_lnextc;
|
up_write(&tty->termios_rwsem);
|
return 0;
|
}
|
#endif
|
|
/**
|
* tty_change_softcar - carrier change ioctl helper
|
* @tty: tty to update
|
* @arg: enable/disable CLOCAL
|
*
|
* Perform a change to the CLOCAL state and call into the driver
|
* layer to make it visible. All done with the termios rwsem
|
*/
|
|
static int tty_change_softcar(struct tty_struct *tty, int arg)
|
{
|
int ret = 0;
|
int bit = arg ? CLOCAL : 0;
|
struct ktermios old;
|
|
down_write(&tty->termios_rwsem);
|
old = tty->termios;
|
tty->termios.c_cflag &= ~CLOCAL;
|
tty->termios.c_cflag |= bit;
|
if (tty->ops->set_termios)
|
tty->ops->set_termios(tty, &old);
|
if (C_CLOCAL(tty) != bit)
|
ret = -EINVAL;
|
up_write(&tty->termios_rwsem);
|
return ret;
|
}
|
|
/**
|
* tty_mode_ioctl - mode related ioctls
|
* @tty: tty for the ioctl
|
* @file: file pointer for the tty
|
* @cmd: command
|
* @arg: ioctl argument
|
*
|
* Perform non line discipline specific mode control ioctls. This
|
* is designed to be called by line disciplines to ensure they provide
|
* consistent mode setting.
|
*/
|
|
int tty_mode_ioctl(struct tty_struct *tty, struct file *file,
|
unsigned int cmd, unsigned long arg)
|
{
|
struct tty_struct *real_tty;
|
void __user *p = (void __user *)arg;
|
int ret = 0;
|
struct ktermios kterm;
|
|
BUG_ON(file == NULL);
|
|
if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
|
tty->driver->subtype == PTY_TYPE_MASTER)
|
real_tty = tty->link;
|
else
|
real_tty = tty;
|
|
switch (cmd) {
|
#ifdef TIOCGETP
|
case TIOCGETP:
|
return get_sgttyb(real_tty, (struct sgttyb __user *) arg);
|
case TIOCSETP:
|
case TIOCSETN:
|
return set_sgttyb(real_tty, (struct sgttyb __user *) arg);
|
#endif
|
#ifdef TIOCGETC
|
case TIOCGETC:
|
return get_tchars(real_tty, p);
|
case TIOCSETC:
|
return set_tchars(real_tty, p);
|
#endif
|
#ifdef TIOCGLTC
|
case TIOCGLTC:
|
return get_ltchars(real_tty, p);
|
case TIOCSLTC:
|
return set_ltchars(real_tty, p);
|
#endif
|
case TCSETSF:
|
return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_OLD);
|
case TCSETSW:
|
return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_OLD);
|
case TCSETS:
|
return set_termios(real_tty, p, TERMIOS_OLD);
|
#ifndef TCGETS2
|
case TCGETS:
|
copy_termios(real_tty, &kterm);
|
if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
|
ret = -EFAULT;
|
return ret;
|
#else
|
case TCGETS:
|
copy_termios(real_tty, &kterm);
|
if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
|
ret = -EFAULT;
|
return ret;
|
case TCGETS2:
|
copy_termios(real_tty, &kterm);
|
if (kernel_termios_to_user_termios((struct termios2 __user *)arg, &kterm))
|
ret = -EFAULT;
|
return ret;
|
case TCSETSF2:
|
return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT);
|
case TCSETSW2:
|
return set_termios(real_tty, p, TERMIOS_WAIT);
|
case TCSETS2:
|
return set_termios(real_tty, p, 0);
|
#endif
|
case TCGETA:
|
return get_termio(real_tty, p);
|
case TCSETAF:
|
return set_termios(real_tty, p, TERMIOS_FLUSH | TERMIOS_WAIT | TERMIOS_TERMIO);
|
case TCSETAW:
|
return set_termios(real_tty, p, TERMIOS_WAIT | TERMIOS_TERMIO);
|
case TCSETA:
|
return set_termios(real_tty, p, TERMIOS_TERMIO);
|
#ifndef TCGETS2
|
case TIOCGLCKTRMIOS:
|
copy_termios_locked(real_tty, &kterm);
|
if (kernel_termios_to_user_termios((struct termios __user *)arg, &kterm))
|
ret = -EFAULT;
|
return ret;
|
case TIOCSLCKTRMIOS:
|
if (!capable(CAP_SYS_ADMIN))
|
return -EPERM;
|
copy_termios_locked(real_tty, &kterm);
|
if (user_termios_to_kernel_termios(&kterm,
|
(struct termios __user *) arg))
|
return -EFAULT;
|
down_write(&real_tty->termios_rwsem);
|
real_tty->termios_locked = kterm;
|
up_write(&real_tty->termios_rwsem);
|
return 0;
|
#else
|
case TIOCGLCKTRMIOS:
|
copy_termios_locked(real_tty, &kterm);
|
if (kernel_termios_to_user_termios_1((struct termios __user *)arg, &kterm))
|
ret = -EFAULT;
|
return ret;
|
case TIOCSLCKTRMIOS:
|
if (!capable(CAP_SYS_ADMIN))
|
return -EPERM;
|
copy_termios_locked(real_tty, &kterm);
|
if (user_termios_to_kernel_termios_1(&kterm,
|
(struct termios __user *) arg))
|
return -EFAULT;
|
down_write(&real_tty->termios_rwsem);
|
real_tty->termios_locked = kterm;
|
up_write(&real_tty->termios_rwsem);
|
return ret;
|
#endif
|
#ifdef TCGETX
|
case TCGETX:
|
case TCSETX:
|
case TCSETXW:
|
case TCSETXF:
|
return -ENOTTY;
|
#endif
|
case TIOCGSOFTCAR:
|
copy_termios(real_tty, &kterm);
|
ret = put_user((kterm.c_cflag & CLOCAL) ? 1 : 0,
|
(int __user *)arg);
|
return ret;
|
case TIOCSSOFTCAR:
|
if (get_user(arg, (unsigned int __user *) arg))
|
return -EFAULT;
|
return tty_change_softcar(real_tty, arg);
|
default:
|
return -ENOIOCTLCMD;
|
}
|
}
|
EXPORT_SYMBOL_GPL(tty_mode_ioctl);
|
|
|
/* Caller guarantees ldisc reference is held */
|
static int __tty_perform_flush(struct tty_struct *tty, unsigned long arg)
|
{
|
struct tty_ldisc *ld = tty->ldisc;
|
|
switch (arg) {
|
case TCIFLUSH:
|
if (ld && ld->ops->flush_buffer) {
|
ld->ops->flush_buffer(tty);
|
tty_unthrottle(tty);
|
}
|
break;
|
case TCIOFLUSH:
|
if (ld && ld->ops->flush_buffer) {
|
ld->ops->flush_buffer(tty);
|
tty_unthrottle(tty);
|
}
|
fallthrough;
|
case TCOFLUSH:
|
tty_driver_flush_buffer(tty);
|
break;
|
default:
|
return -EINVAL;
|
}
|
return 0;
|
}
|
|
int tty_perform_flush(struct tty_struct *tty, unsigned long arg)
|
{
|
struct tty_ldisc *ld;
|
int retval = tty_check_change(tty);
|
if (retval)
|
return retval;
|
|
ld = tty_ldisc_ref_wait(tty);
|
retval = __tty_perform_flush(tty, arg);
|
if (ld)
|
tty_ldisc_deref(ld);
|
return retval;
|
}
|
EXPORT_SYMBOL_GPL(tty_perform_flush);
|
|
int n_tty_ioctl_helper(struct tty_struct *tty, struct file *file,
|
unsigned int cmd, unsigned long arg)
|
{
|
int retval;
|
|
switch (cmd) {
|
case TCXONC:
|
retval = tty_check_change(tty);
|
if (retval)
|
return retval;
|
switch (arg) {
|
case TCOOFF:
|
spin_lock_irq(&tty->flow_lock);
|
if (!tty->flow_stopped) {
|
tty->flow_stopped = 1;
|
__stop_tty(tty);
|
}
|
spin_unlock_irq(&tty->flow_lock);
|
break;
|
case TCOON:
|
spin_lock_irq(&tty->flow_lock);
|
if (tty->flow_stopped) {
|
tty->flow_stopped = 0;
|
__start_tty(tty);
|
}
|
spin_unlock_irq(&tty->flow_lock);
|
break;
|
case TCIOFF:
|
if (STOP_CHAR(tty) != __DISABLED_CHAR)
|
retval = tty_send_xchar(tty, STOP_CHAR(tty));
|
break;
|
case TCION:
|
if (START_CHAR(tty) != __DISABLED_CHAR)
|
retval = tty_send_xchar(tty, START_CHAR(tty));
|
break;
|
default:
|
return -EINVAL;
|
}
|
return retval;
|
case TCFLSH:
|
retval = tty_check_change(tty);
|
if (retval)
|
return retval;
|
return __tty_perform_flush(tty, arg);
|
default:
|
/* Try the mode commands */
|
return tty_mode_ioctl(tty, file, cmd, arg);
|
}
|
}
|
EXPORT_SYMBOL(n_tty_ioctl_helper);
|
