tty_ioctl.c

来自「linux 内核源代码」· C语言 代码 · 共 983 行 · 第 1/2 页

	} else {
		if (user_termios_to_kernel_termios(&tmp_termios,
						(struct termios2 __user *)arg))
			return -EFAULT;
	}
#else
	} else if (user_termios_to_kernel_termios(&tmp_termios,
					(struct termios __user *)arg))
		return -EFAULT;
#endif

	/* If old style Bfoo values are used then load c_ispeed/c_ospeed with the real speed
	   so its unconditionally usable */
	tmp_termios.c_ispeed = tty_termios_input_baud_rate(&tmp_termios);
	tmp_termios.c_ospeed = tty_termios_baud_rate(&tmp_termios);

	ld = tty_ldisc_ref(tty);
	
	if (ld != NULL) {
		if ((opt & TERMIOS_FLUSH) && ld->flush_buffer)
			ld->flush_buffer(tty);
		tty_ldisc_deref(ld);
	}
	
	if (opt & TERMIOS_WAIT) {
		tty_wait_until_sent(tty, 0);
		if (signal_pending(current))
			return -EINTR;
	}

	change_termios(tty, &tmp_termios);

	/* 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 */
	return 0;
}

static int get_termio(struct tty_struct * tty, struct termio __user * termio)
{
	if (kernel_termios_to_user_termio(termio, tty->termios))
		return -EFAULT;
	return 0;
}

static unsigned long inq_canon(struct tty_struct * tty)
{
	int nr, head, tail;

	if (!tty->canon_data || !tty->read_buf)
		return 0;
	head = tty->canon_head;
	tail = tty->read_tail;
	nr = (head - tail) & (N_TTY_BUF_SIZE-1);
	/* Skip EOF-chars.. */
	while (head != tail) {
		if (test_bit(tail, tty->read_flags) &&
		    tty->read_buf[tail] == __DISABLED_CHAR)
			nr--;
		tail = (tail+1) & (N_TTY_BUF_SIZE-1);
	}
	return nr;
}

#ifdef TIOCGETP
/*
 * These are deprecated, but there is limited support..
 *
 * The "sg_flags" translation is a joke..
 */
static int get_sgflags(struct tty_struct * tty)
{
	int flags = 0;

	if (!(tty->termios->c_lflag & ICANON)) {
		if (tty->termios->c_lflag & ISIG)
			flags |= 0x02;		/* cbreak */
		else
			flags |= 0x20;		/* raw */
	}
	if (tty->termios->c_lflag & ECHO)
		flags |= 0x08;			/* echo */
	if (tty->termios->c_oflag & OPOST)
		if (tty->termios->c_oflag & ONLCR)
			flags |= 0x10;		/* crmod */
	return flags;
}

static int get_sgttyb(struct tty_struct * tty, struct sgttyb __user * sgttyb)
{
	struct sgttyb tmp;

	mutex_lock(&tty->termios_mutex);
	tmp.sg_ispeed = tty->termios->c_ispeed;
	tmp.sg_ospeed = tty->termios->c_ospeed;
	tmp.sg_erase = tty->termios->c_cc[VERASE];
	tmp.sg_kill = tty->termios->c_cc[VKILL];
	tmp.sg_flags = get_sgflags(tty);
	mutex_unlock(&tty->termios_mutex);
	
	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_sem
 */

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;

	mutex_lock(&tty->termios_mutex);
	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
	mutex_unlock(&tty->termios_mutex);
	change_termios(tty, &termios);
	return 0;
}
#endif

#ifdef TIOCGETC
static int get_tchars(struct tty_struct * tty, struct tchars __user * tchars)
{
	struct tchars tmp;

	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? */
	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;
	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? */
	return 0;
}
#endif

#ifdef TIOCGLTC
static int get_ltchars(struct tty_struct * tty, struct ltchars __user * ltchars)
{
	struct ltchars tmp;

	tmp.t_suspc = tty->termios->c_cc[VSUSP];
	tmp.t_dsuspc = tty->termios->c_cc[VSUSP];	/* what is dsuspc anyway? */
	tmp.t_rprntc = tty->termios->c_cc[VREPRINT];
	tmp.t_flushc = tty->termios->c_cc[VEOL2];	/* what is flushc anyway? */
	tmp.t_werasc = tty->termios->c_cc[VWERASE];
	tmp.t_lnextc = tty->termios->c_cc[VLNEXT];
	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;

	tty->termios->c_cc[VSUSP] = tmp.t_suspc;
	tty->termios->c_cc[VEOL2] = tmp.t_dsuspc;	/* what is dsuspc anyway? */
	tty->termios->c_cc[VREPRINT] = tmp.t_rprntc;
	tty->termios->c_cc[VEOL2] = tmp.t_flushc;	/* what is flushc anyway? */
	tty->termios->c_cc[VWERASE] = tmp.t_werasc;
	tty->termios->c_cc[VLNEXT] = tmp.t_lnextc;
	return 0;
}
#endif

/**
 *	send_prio_char		-	send priority character
 *
 *	Send a high priority character to the tty even if stopped
 *
 *	Locking: none for xchar method, write ordering for write method.
 */

static int send_prio_char(struct tty_struct *tty, char ch)
{
	int	was_stopped = tty->stopped;

	if (tty->driver->send_xchar) {
		tty->driver->send_xchar(tty, ch);
		return 0;
	}

	if (tty_write_lock(tty, 0) < 0)
		return -ERESTARTSYS;

	if (was_stopped)
		start_tty(tty);
	tty->driver->write(tty, &ch, 1);
	if (was_stopped)
		stop_tty(tty);
	tty_write_unlock(tty);
	return 0;
}

/**
 *	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;

	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:
			if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios))
				return -EFAULT;
			return 0;
#else
		case TCGETS:
			if (kernel_termios_to_user_termios_1((struct termios __user *)arg, real_tty->termios))
				return -EFAULT;
			return 0;
		case TCGETS2:
			if (kernel_termios_to_user_termios((struct termios2 __user *)arg, real_tty->termios))
				return -EFAULT;
			return 0;
		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:
			if (kernel_termios_to_user_termios((struct termios __user *)arg, real_tty->termios_locked))
				return -EFAULT;
			return 0;

		case TIOCSLCKTRMIOS:
			if (!capable(CAP_SYS_ADMIN))
				return -EPERM;
			if (user_termios_to_kernel_termios(real_tty->termios_locked, (struct termios __user *) arg))
				return -EFAULT;
			return 0;
#else
		case TIOCGLCKTRMIOS:
			if (kernel_termios_to_user_termios_1((struct termios __user *)arg, real_tty->termios_locked))
				return -EFAULT;
			return 0;

		case TIOCSLCKTRMIOS:
			if (!capable(CAP_SYS_ADMIN))
				return -EPERM;
			if (user_termios_to_kernel_termios_1(real_tty->termios_locked, (struct termios __user *) arg))
				return -EFAULT;
			return 0;
#endif
		case TIOCGSOFTCAR:
			return put_user(C_CLOCAL(tty) ? 1 : 0, (int __user *)arg);
		case TIOCSSOFTCAR:
			if (get_user(arg, (unsigned int __user *) arg))
				return -EFAULT;
			mutex_lock(&tty->termios_mutex);
			tty->termios->c_cflag =
				((tty->termios->c_cflag & ~CLOCAL) |
				 (arg ? CLOCAL : 0));
			mutex_unlock(&tty->termios_mutex);
			return 0;
		default:
			return -ENOIOCTLCMD;
	}
}

EXPORT_SYMBOL_GPL(tty_mode_ioctl);

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(tty);
	switch (arg) {
	case TCIFLUSH:
		if (ld && ld->flush_buffer)
			ld->flush_buffer(tty);
		break;
	case TCIOFLUSH:
		if (ld && ld->flush_buffer)
			ld->flush_buffer(tty);
		/* fall through */
	case TCOFLUSH:
		if (tty->driver->flush_buffer)
			tty->driver->flush_buffer(tty);
		break;
	default:
		tty_ldisc_deref(ld);
		return -EINVAL;
	}
	tty_ldisc_deref(ld);
	return 0;
}

EXPORT_SYMBOL_GPL(tty_perform_flush);

int n_tty_ioctl(struct tty_struct * tty, struct file * file,
		       unsigned int cmd, unsigned long arg)
{
	struct tty_struct * real_tty;
	int retval;

	if (tty->driver->type == TTY_DRIVER_TYPE_PTY &&
	    tty->driver->subtype == PTY_TYPE_MASTER)
		real_tty = tty->link;
	else
		real_tty = tty;

	switch (cmd) {
		case TCXONC:
			retval = tty_check_change(tty);
			if (retval)
				return retval;
			switch (arg) {
			case TCOOFF:
				if (!tty->flow_stopped) {
					tty->flow_stopped = 1;
					stop_tty(tty);
				}
				break;
			case TCOON:
				if (tty->flow_stopped) {
					tty->flow_stopped = 0;
					start_tty(tty);
				}
				break;
			case TCIOFF:
				if (STOP_CHAR(tty) != __DISABLED_CHAR)
					return send_prio_char(tty, STOP_CHAR(tty));
				break;
			case TCION:
				if (START_CHAR(tty) != __DISABLED_CHAR)
					return send_prio_char(tty, START_CHAR(tty));
				break;
			default:
				return -EINVAL;
			}
			return 0;
		case TCFLSH:
			return tty_perform_flush(tty, arg);
		case TIOCOUTQ:
			return put_user(tty->driver->chars_in_buffer ?
					tty->driver->chars_in_buffer(tty) : 0,
					(int __user *) arg);
		case TIOCINQ:
			retval = tty->read_cnt;
			if (L_ICANON(tty))
				retval = inq_canon(tty);
			return put_user(retval, (unsigned int __user *) arg);
		case TIOCPKT:
		{
			int pktmode;

			if (tty->driver->type != TTY_DRIVER_TYPE_PTY ||
			    tty->driver->subtype != PTY_TYPE_MASTER)
				return -ENOTTY;
			if (get_user(pktmode, (int __user *) arg))
				return -EFAULT;
			if (pktmode) {
				if (!tty->packet) {
					tty->packet = 1;
					tty->link->ctrl_status = 0;
				}
			} else
				tty->packet = 0;
			return 0;
		}
		default:
			/* Try the mode commands */
			return tty_mode_ioctl(tty, file, cmd, arg);
		}
}

EXPORT_SYMBOL(n_tty_ioctl);