tty_pty.c

早期freebsd实现

/*
 * Copyright (c) 1982, 1986, 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)tty_pty.c	8.2 (Berkeley) 9/23/93
 */

/*
 * Pseudo-teletype Driver
 * (Actually two drivers, requiring two entries in 'cdevsw')
 */
#include "pty.h"		/* XXX */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/ioctl.h>
#include <sys/proc.h>
#include <sys/tty.h>
#include <sys/conf.h>
#include <sys/file.h>
#include <sys/uio.h>
#include <sys/kernel.h>
#include <sys/vnode.h>

#if NPTY == 1
#undef NPTY
#define	NPTY	32		/* crude XXX */
#endif

#define BUFSIZ 100		/* Chunk size iomoved to/from user */

/*
 * pts == /dev/tty[pqrs]?
 * ptc == /dev/pty[pqrs]?
 */
struct	tty pt_tty[NPTY];	/* XXX */
struct	pt_ioctl {
	int	pt_flags;
	struct	selinfo pt_selr, pt_selw;
	u_char	pt_send;
	u_char	pt_ucntl;
} pt_ioctl[NPTY];		/* XXX */
int	npty = NPTY;		/* for pstat -t */

#define	PF_PKT		0x08		/* packet mode */
#define	PF_STOPPED	0x10		/* user told stopped */
#define	PF_REMOTE	0x20		/* remote and flow controlled input */
#define	PF_NOSTOP	0x40
#define PF_UCNTL	0x80		/* user control mode */

void	ptsstop __P((struct tty *, int));

/*
 * Establish n (or default if n is 1) ptys in the system.
 *
 * XXX cdevsw & pstat require the array `pty[]' to be an array
 */
void
ptyattach(n)
	int n;
{
#ifdef notyet
	char *mem;
	register u_long ntb;
#define	DEFAULT_NPTY	32

	/* maybe should allow 0 => none? */
	if (n <= 1)
		n = DEFAULT_NPTY;
	ntb = n * sizeof(struct tty);
	mem = malloc(ntb + ALIGNBYTES + n * sizeof(struct pt_ioctl),
	    M_DEVBUF, M_WAITOK);
	pt_tty = (struct tty *)mem;
	mem = (char *)ALIGN(mem + ntb);
	pt_ioctl = (struct pt_ioctl *)mem;
	npty = n;
#endif
}

/*ARGSUSED*/
ptsopen(dev, flag, devtype, p)
	dev_t dev;
	int flag, devtype;
	struct proc *p;
{
	register struct tty *tp;
	int error;

	if (minor(dev) >= npty)
		return (ENXIO);
	tp = &pt_tty[minor(dev)];
	if ((tp->t_state & TS_ISOPEN) == 0) {
		tp->t_state |= TS_WOPEN;
		ttychars(tp);		/* Set up default chars */
		tp->t_iflag = TTYDEF_IFLAG;
		tp->t_oflag = TTYDEF_OFLAG;
		tp->t_lflag = TTYDEF_LFLAG;
		tp->t_cflag = TTYDEF_CFLAG;
		tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
		ttsetwater(tp);		/* would be done in xxparam() */
	} else if (tp->t_state&TS_XCLUDE && p->p_ucred->cr_uid != 0)
		return (EBUSY);
	if (tp->t_oproc)			/* Ctrlr still around. */
		tp->t_state |= TS_CARR_ON;
	while ((tp->t_state & TS_CARR_ON) == 0) {
		tp->t_state |= TS_WOPEN;
		if (flag&FNONBLOCK)
			break;
		if (error = ttysleep(tp, (caddr_t)&tp->t_rawq, TTIPRI | PCATCH,
		    ttopen, 0))
			return (error);
	}
	error = (*linesw[tp->t_line].l_open)(dev, tp);
	ptcwakeup(tp, FREAD|FWRITE);
	return (error);
}

ptsclose(dev, flag, mode, p)
	dev_t dev;
	int flag, mode;
	struct proc *p;
{
	register struct tty *tp;
	int err;

	tp = &pt_tty[minor(dev)];
	err = (*linesw[tp->t_line].l_close)(tp, flag);
	err |= ttyclose(tp);
	ptcwakeup(tp, FREAD|FWRITE);
	return (err);
}

ptsread(dev, uio, flag)
	dev_t dev;
	struct uio *uio;
	int flag;
{
	struct proc *p = curproc;
	register struct tty *tp = &pt_tty[minor(dev)];
	register struct pt_ioctl *pti = &pt_ioctl[minor(dev)];
	int error = 0;

again:
	if (pti->pt_flags & PF_REMOTE) {
		while (isbackground(p, tp)) {
			if ((p->p_sigignore & sigmask(SIGTTIN)) ||
			    (p->p_sigmask & sigmask(SIGTTIN)) ||
			    p->p_pgrp->pg_jobc == 0 ||
			    p->p_flag & P_PPWAIT)
				return (EIO);
			pgsignal(p->p_pgrp, SIGTTIN, 1);
			if (error = ttysleep(tp, (caddr_t)&lbolt, 
			    TTIPRI | PCATCH, ttybg, 0))
				return (error);
		}
		if (tp->t_canq.c_cc == 0) {
			if (flag & IO_NDELAY)
				return (EWOULDBLOCK);
			if (error = ttysleep(tp, (caddr_t)&tp->t_canq,
			    TTIPRI | PCATCH, ttyin, 0))
				return (error);
			goto again;
		}
		while (tp->t_canq.c_cc > 1 && uio->uio_resid > 0)
			if (ureadc(getc(&tp->t_canq), uio) < 0) {
				error = EFAULT;
				break;
			}
		if (tp->t_canq.c_cc == 1)
			(void) getc(&tp->t_canq);
		if (tp->t_canq.c_cc)
			return (error);
	} else
		if (tp->t_oproc)
			error = (*linesw[tp->t_line].l_read)(tp, uio, flag);
	ptcwakeup(tp, FWRITE);
	return (error);
}

/*
 * Write to pseudo-tty.
 * Wakeups of controlling tty will happen
 * indirectly, when tty driver calls ptsstart.
 */
ptswrite(dev, uio, flag)
	dev_t dev;
	struct uio *uio;
	int flag;
{
	register struct tty *tp;

	tp = &pt_tty[minor(dev)];
	if (tp->t_oproc == 0)
		return (EIO);
	return ((*linesw[tp->t_line].l_write)(tp, uio, flag));
}

/*
 * Start output on pseudo-tty.
 * Wake up process selecting or sleeping for input from controlling tty.
 */
void
ptsstart(tp)
	struct tty *tp;
{
	register struct pt_ioctl *pti = &pt_ioctl[minor(tp->t_dev)];

	if (tp->t_state & TS_TTSTOP)
		return;
	if (pti->pt_flags & PF_STOPPED) {
		pti->pt_flags &= ~PF_STOPPED;
		pti->pt_send = TIOCPKT_START;
	}
	ptcwakeup(tp, FREAD);
}

ptcwakeup(tp, flag)
	struct tty *tp;
	int flag;
{
	struct pt_ioctl *pti = &pt_ioctl[minor(tp->t_dev)];

	if (flag & FREAD) {
		selwakeup(&pti->pt_selr);
		wakeup((caddr_t)&tp->t_outq.c_cf);
	}
	if (flag & FWRITE) {
		selwakeup(&pti->pt_selw);
		wakeup((caddr_t)&tp->t_rawq.c_cf);
	}
}

/*ARGSUSED*/
#ifdef __STDC__
ptcopen(dev_t dev, int flag, int devtype, struct proc *p)
#else
ptcopen(dev, flag, devtype, p)
	dev_t dev;
	int flag, devtype;
	struct proc *p;
#endif
{
	register struct tty *tp;
	struct pt_ioctl *pti;

	if (minor(dev) >= npty)
		return (ENXIO);
	tp = &pt_tty[minor(dev)];
	if (tp->t_oproc)
		return (EIO);
	tp->t_oproc = ptsstart;
#ifdef sun4c
	tp->t_stop = ptsstop;
#endif
	(void)(*linesw[tp->t_line].l_modem)(tp, 1);
	tp->t_lflag &= ~EXTPROC;
	pti = &pt_ioctl[minor(dev)];
	pti->pt_flags = 0;
	pti->pt_send = 0;
	pti->pt_ucntl = 0;
	return (0);
}

ptcclose(dev)
	dev_t dev;
{
	register struct tty *tp;

	tp = &pt_tty[minor(dev)];
	(void)(*linesw[tp->t_line].l_modem)(tp, 0);
	tp->t_state &= ~TS_CARR_ON;
	tp->t_oproc = 0;		/* mark closed */
	tp->t_session = 0;
	return (0);
}

ptcread(dev, uio, flag)
	dev_t dev;
	struct uio *uio;
	int flag;
{
	register struct tty *tp = &pt_tty[minor(dev)];
	struct pt_ioctl *pti = &pt_ioctl[minor(dev)];
	char buf[BUFSIZ];
	int error = 0, cc;

	/*
	 * We want to block until the slave
	 * is open, and there's something to read;
	 * but if we lost the slave or we're NBIO,
	 * then return the appropriate error instead.
	 */
	for (;;) {
		if (tp->t_state&TS_ISOPEN) {
			if (pti->pt_flags&PF_PKT && pti->pt_send) {
				error = ureadc((int)pti->pt_send, uio);
				if (error)
					return (error);
				if (pti->pt_send & TIOCPKT_IOCTL) {
					cc = min(uio->uio_resid,
						sizeof(tp->t_termios));
					uiomove(&tp->t_termios, cc, uio);
				}
				pti->pt_send = 0;
				return (0);
			}
			if (pti->pt_flags&PF_UCNTL && pti->pt_ucntl) {
				error = ureadc((int)pti->pt_ucntl, uio);
				if (error)
					return (error);
				pti->pt_ucntl = 0;
				return (0);
			}
			if (tp->t_outq.c_cc && (tp->t_state&TS_TTSTOP) == 0)
				break;
		}
		if ((tp->t_state&TS_CARR_ON) == 0)
			return (0);	/* EOF */