usr/src/sys/kern/tty_pty.c

/*	tty_pty.c	4.24	82/08/22	*/

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

#if NPTY > 0
#include "../h/param.h"
#include "../h/systm.h"
#include "../h/tty.h"
#include "../h/dir.h"
#include "../h/user.h"
#include "../h/conf.h"
#include "../h/file.h"
#include "../h/proc.h"
#include "../h/uio.h"

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

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

/*
 * pts == /dev/tty[pP]?
 * ptc == /dev/ptp[pP]?
 */
struct	tty pt_tty[NPTY];
struct	pt_ioctl {
	int	pt_flags;
	int	pt_gensym;
	struct	proc *pt_selr, *pt_selw;
	int	pt_send;
} pt_ioctl[NPTY];

#define	PF_RCOLL	0x01
#define	PF_WCOLL	0x02
#define	PF_NBIO		0x04
#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

/*ARGSUSED*/
ptsopen(dev, flag)
	dev_t dev;
{
	register struct tty *tp;

	if (minor(dev) >= NPTY) {
		u.u_error = ENXIO;
		return;
	}
	tp = &pt_tty[minor(dev)];
	if ((tp->t_state & TS_ISOPEN) == 0) {
		ttychars(tp);		/* Set up default chars */
		tp->t_flags = 0;	/* No features (nor raw mode) */
	} else if (tp->t_state&TS_XCLUDE && u.u_uid != 0) {
		u.u_error = EBUSY;
		return;
	}
	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;
		sleep((caddr_t)&tp->t_rawq, TTIPRI);
	}
	(*linesw[tp->t_line].l_open)(dev, tp);
}

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

	tp = &pt_tty[minor(dev)];
	(*linesw[tp->t_line].l_close)(tp);
	ttyclose(tp);
}

ptsread(dev, uio)
	dev_t dev;
	struct uio *uio;
{
	register struct tty *tp = &pt_tty[minor(dev)];
	register struct pt_ioctl *pti = &pt_ioctl[minor(dev)];

again:
	if (pti->pt_flags & PF_REMOTE) {
		while (tp == u.u_ttyp && u.u_procp->p_pgrp != tp->t_pgrp) {
			if (u.u_signal[SIGTTIN] == SIG_IGN ||
			    u.u_signal[SIGTTIN] == SIG_HOLD ||
	/*
			    (u.u_procp->p_flag&SDETACH) ||
	*/
			    u.u_procp->p_flag&SVFORK)
				return;
			gsignal(u.u_procp->p_pgrp, SIGTTIN);
			sleep((caddr_t)&lbolt, TTIPRI);
		}
		if (tp->t_rawq.c_cc == 0) {
			if (tp->t_state & TS_NBIO) {
				u.u_error = EWOULDBLOCK;
				return;
			}
			sleep((caddr_t)&tp->t_rawq, TTIPRI);
			goto again;
		}
		while (tp->t_rawq.c_cc > 1 && uio->uio_resid > 0)
			if (ureadc(getc(&tp->t_rawq), uio) < 0) {
				u.u_error = EFAULT;
				break;
			}
		if (tp->t_rawq.c_cc == 1)
			(void) getc(&tp->t_rawq);
		if (tp->t_rawq.c_cc)
			return;
	} else
		if (tp->t_oproc)
			(*linesw[tp->t_line].l_read)(tp, uio);
	wakeup((caddr_t)&tp->t_rawq.c_cf);
	if (pti->pt_selw) {
		selwakeup(pti->pt_selw, pti->pt_flags & PF_WCOLL);
		pti->pt_selw = 0;
		pti->pt_flags &= ~PF_WCOLL;
	}
}

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

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

/*
 * Start output on pseudo-tty.
 * Wake up process selecting or sleeping for input from controlling tty.
 */
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);
}

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

	if (pti->pt_selr) {
		selwakeup(pti->pt_selr, pti->pt_flags & PF_RCOLL);
		pti->pt_selr = 0;
		pti->pt_flags &= ~PF_RCOLL;
	}
	wakeup((caddr_t)&tp->t_outq.c_cf);
}

/*ARGSUSED*/
ptcopen(dev, flag)
	dev_t dev;
	int flag;
{
	register struct tty *tp;
	struct pt_ioctl *pti;

	if (minor(dev) >= NPTY) {
		u.u_error = ENXIO;
		return;
	}
	tp = &pt_tty[minor(dev)];
	if (tp->t_oproc) {
		u.u_error = EIO;
		return;
	}
	tp->t_oproc = ptsstart;
	if (tp->t_state & TS_WOPEN)
		wakeup((caddr_t)&tp->t_rawq);
	tp->t_state |= TS_CARR_ON;
	pti = &pt_ioctl[minor(dev)];
	pti->pt_flags = 0;
	pti->pt_send = 0;
}

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

	tp = &pt_tty[minor(dev)];
	if (tp->t_state & TS_ISOPEN)
		gsignal(tp->t_pgrp, SIGHUP);
	tp->t_state &= ~TS_CARR_ON;	/* virtual carrier gone */
	flushtty(tp, FREAD|FWRITE);
	tp->t_oproc = 0;		/* mark closed */
}

ptcread(dev, uio)
	dev_t dev;
	struct uio *uio;
{
	register struct tty *tp;
	struct pt_ioctl *pti;

	tp = &pt_tty[minor(dev)];
	if ((tp->t_state&(TS_CARR_ON|TS_ISOPEN)) == 0)
		return;
	pti = &pt_ioctl[minor(dev)];
	if (pti->pt_flags & PF_PKT) {
		if (pti->pt_send) {
			(void) ureadc(pti->pt_send, uio);
			pti->pt_send = 0;
			return;
		}
		(void) ureadc(0, uio);
	}
	while (tp->t_outq.c_cc == 0 || (tp->t_state&TS_TTSTOP)) {
		if (pti->pt_flags&PF_NBIO) {
			u.u_error = EWOULDBLOCK;
			return;
		}
		sleep((caddr_t)&tp->t_outq.c_cf, TTIPRI);
	}
	while (tp->t_outq.c_cc && uio->uio_resid > 0)
		if (ureadc(getc(&tp->t_outq), uio) < 0) {
			u.u_error = EFAULT;
			break;
		}
	if (tp->t_outq.c_cc <= TTLOWAT(tp)) {
		if (tp->t_state&TS_ASLEEP) {
			tp->t_state &= ~TS_ASLEEP;
			wakeup((caddr_t)&tp->t_outq);
		}
		if (tp->t_wsel) {
			selwakeup(tp->t_wsel, tp->t_state & TS_WCOLL);
			tp->t_wsel = 0;
			tp->t_state &= ~TS_WCOLL;
		}
	}
}

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

	/* note: FLUSHREAD and FLUSHWRITE already ok */
	if (flush == 0) {
		flush = TIOCPKT_STOP;
		pti->pt_flags |= PF_STOPPED;
	} else {
		pti->pt_flags &= ~PF_STOPPED;
	}
	pti->pt_send |= flush;
	ptcwakeup(tp);
}

ptcselect(dev, rw)
	dev_t dev;
	int rw;
{
	register struct tty *tp = &pt_tty[minor(dev)];
	struct pt_ioctl *pti = &pt_ioctl[minor(dev)];
	struct proc *p;
	int s;

	if ((tp->t_state&(TS_CARR_ON|TS_ISOPEN)) == 0)
		return (1);
	s = spl5();
	switch (rw) {

	case FREAD:
		if (tp->t_outq.c_cc && (tp->t_state&TS_TTSTOP) == 0) {
			splx(s);
			return (1);
		}
		if ((p = pti->pt_selr) && p->p_wchan == (caddr_t)&selwait)
			pti->pt_flags |= PF_RCOLL;
		else
			pti->pt_selr = u.u_procp;
		break;

	case FWRITE:
		if ((pti->pt_flags & PF_REMOTE) == 0 || tp->t_rawq.c_cc == 0) {
			splx(s);
			return (1);
		}
		if ((p = pti->pt_selw) && p->p_wchan == (caddr_t)&selwait)
			pti->pt_flags |= PF_WCOLL;
		else
			pti->pt_selw = u.u_procp;
		break;
	}
	splx(s);
	return (0);
}

ptcwrite(dev, uio)
	dev_t dev;
	struct uio *uio;
{
	register struct tty *tp;
	register char *cp, *ce;
	register int cc;
	char locbuf[BUFSIZ];
	int cnt = 0;
	struct pt_ioctl *pti = &pt_ioctl[minor(dev)];

	tp = &pt_tty[minor(dev)];
	if ((tp->t_state&(TS_CARR_ON|TS_ISOPEN)) == 0)
		return;
	do {
		register struct iovec *iov;

		if (uio->uio_iovcnt == 0)
			break;
		iov = uio->uio_iov;
		if (iov->iov_len == 0) {
			uio->uio_iovcnt--;
			uio->uio_iov++;
			if (uio->uio_iovcnt < 0)
				panic("ptcwrite");
			continue;
		}
		cc = MIN(iov->iov_len, BUFSIZ);
		cp = locbuf;
		u.u_error = uiomove(cp, cc, UIO_WRITE, uio);
		if (u.u_error)
			break;
		ce = cp + cc;
again:
		if (pti->pt_flags & PF_REMOTE) {
			if (tp->t_rawq.c_cc) {
				if (pti->pt_flags & PF_NBIO) {
					iov->iov_base -= ce - cp;
					iov->iov_len += ce - cp;
					uio->uio_resid += ce - cp;
					uio->uio_offset -= ce - cp;
					u.u_error = EWOULDBLOCK;
					return;
				}
				sleep((caddr_t)&tp->t_rawq.c_cf, TTOPRI);
				goto again;
			}
			(void) b_to_q(cp, cc, &tp->t_rawq);
			(void) putc(0, &tp->t_rawq);
			wakeup((caddr_t)&tp->t_rawq);
			return;
		}
		while (cp < ce) {
			while (tp->t_delct && tp->t_rawq.c_cc >= TTYHOG - 2) {
				wakeup((caddr_t)&tp->t_rawq);
				if (tp->t_state & TS_NBIO) {
					iov->iov_base -= ce - cp;
					iov->iov_len += ce - cp;
					uio->uio_resid += ce - cp;
					uio->uio_offset -= ce - cp;
					if (cnt == 0)
						u.u_error = EWOULDBLOCK;
					return;
				}
				/* Better than just flushing it! */
				/* Wait for something to be read */
				sleep((caddr_t)&tp->t_rawq.c_cf, TTOPRI);
				goto again;
			}
			(*linesw[tp->t_line].l_rint)(*cp++, tp);
			cnt++;
		}
	} while (uio->uio_resid);
}

/*ARGSUSED*/
ptyioctl(dev, cmd, data, flag)
	caddr_t data;
	dev_t dev;
{
	register struct tty *tp = &pt_tty[minor(dev)];
	register struct pt_ioctl *pti = &pt_ioctl[minor(dev)];

	/* IF CONTROLLER STTY THEN MUST FLUSH TO PREVENT A HANG ??? */
	if (cdevsw[major(dev)].d_open == ptcopen)
		switch (cmd) {

		case TIOCPKT:
			if (*(int *)data)
				pti->pt_flags |= PF_PKT;
			else
				pti->pt_flags &= ~PF_PKT;
			return;

		case TIOCREMOTE:
			if (*(int *)data)
				pti->pt_flags |= PF_REMOTE;
			else
				pti->pt_flags &= ~PF_REMOTE;
			flushtty(tp, FREAD|FWRITE);
			return;

		case FIONBIO:
			if (*(int *)data)
				pti->pt_flags |= PF_NBIO;
			else
				pti->pt_flags &= ~PF_NBIO;
			return;

		case TIOCSETP:
			while (getc(&tp->t_outq) >= 0)
				;
			break;
		}
	if (ttioctl(tp, cmd, data, dev) == 0)
		u.u_error = ENOTTY;
	{ int stop = (tp->t_un.t_chr.t_stopc == ('s'&037) &&
		      tp->t_un.t_chr.t_startc == ('q'&037));
	if (pti->pt_flags & PF_NOSTOP) {
		if (stop) {
			pti->pt_send &= TIOCPKT_NOSTOP;
			pti->pt_send |= TIOCPKT_DOSTOP;
			pti->pt_flags &= ~PF_NOSTOP;
			ptcwakeup(tp);
		}
	} else {
		if (stop == 0) {
			pti->pt_send &= ~TIOCPKT_DOSTOP;
			pti->pt_send |= TIOCPKT_NOSTOP;
			pti->pt_flags |= PF_NOSTOP;
			ptcwakeup(tp);
		}
	}
	}
}
#endif
Commit	Line	Data
	1	/* tty_pty.c 4.24 82/08/22 */
	2
	3	/*
	4	* Pseudo-teletype Driver
	5	* (Actually two drivers, requiring two entries in 'cdevsw')
	6	*/
	7	#include "pty.h"
	8
	9	#if NPTY > 0
	10	#include "../h/param.h"
	11	#include "../h/systm.h"
	12	#include "../h/tty.h"
	13	#include "../h/dir.h"
	14	#include "../h/user.h"
	15	#include "../h/conf.h"
	16	#include "../h/file.h"
	17	#include "../h/proc.h"
	18	#include "../h/uio.h"
	19
	20	#if NPTY == 1
	21	#undef NPTY
	22	#define NPTY 32 /* crude XXX */
	23	#endif
	24
	25	#define BUFSIZ 100 /* Chunk size iomoved from user */
	26
	27	/*
	28	* pts == /dev/tty[pP]?
	29	* ptc == /dev/ptp[pP]?
	30	*/
	31	struct tty pt_tty[NPTY];
	32	struct pt_ioctl {
	33	int pt_flags;
	34	int pt_gensym;
	35	struct proc pt_selr, pt_selw;
	36	int pt_send;
	37	} pt_ioctl[NPTY];
	38
	39	#define PF_RCOLL 0x01
	40	#define PF_WCOLL 0x02
	41	#define PF_NBIO 0x04
	42	#define PF_PKT 0x08 /* packet mode */
	43	#define PF_STOPPED 0x10 /* user told stopped */
	44	#define PF_REMOTE 0x20 /* remote and flow controlled input */
	45	#define PF_NOSTOP 0x40
	46
	47	/ARGSUSED/
	48	ptsopen(dev, flag)
	49	dev_t dev;
	50	{
	51	register struct tty *tp;
	52
	53	if (minor(dev) >= NPTY) {
	54	u.u_error = ENXIO;
	55	return;
	56	}
	57	tp = &pt_tty[minor(dev)];
	58	if ((tp->t_state & TS_ISOPEN) == 0) {
	59	ttychars(tp); /* Set up default chars */
	60	tp->t_flags = 0; /* No features (nor raw mode) */
	61	} else if (tp->t_state&TS_XCLUDE && u.u_uid != 0) {
	62	u.u_error = EBUSY;
	63	return;
	64	}
	65	if (tp->t_oproc) /* Ctrlr still around. */
	66	tp->t_state \|= TS_CARR_ON;
	67	while ((tp->t_state & TS_CARR_ON) == 0) {
	68	tp->t_state \|= TS_WOPEN;
	69	sleep((caddr_t)&tp->t_rawq, TTIPRI);
	70	}
	71	(*linesw[tp->t_line].l_open)(dev, tp);
	72	}
	73
	74	ptsclose(dev)
	75	dev_t dev;
	76	{
	77	register struct tty *tp;
	78
	79	tp = &pt_tty[minor(dev)];
	80	(*linesw[tp->t_line].l_close)(tp);
	81	ttyclose(tp);
	82	}
	83
	84	ptsread(dev, uio)
	85	dev_t dev;
	86	struct uio *uio;
	87	{
	88	register struct tty *tp = &pt_tty[minor(dev)];
	89	register struct pt_ioctl *pti = &pt_ioctl[minor(dev)];
	90
	91	again:
	92	if (pti->pt_flags & PF_REMOTE) {
	93	while (tp == u.u_ttyp && u.u_procp->p_pgrp != tp->t_pgrp) {
	94	if (u.u_signal[SIGTTIN] == SIG_IGN \|\|
	95	u.u_signal[SIGTTIN] == SIG_HOLD \|\|
	96	/*
	97	(u.u_procp->p_flag&SDETACH) \|\|
	98	*/
	99	u.u_procp->p_flag&SVFORK)
	100	return;
	101	gsignal(u.u_procp->p_pgrp, SIGTTIN);
	102	sleep((caddr_t)&lbolt, TTIPRI);
	103	}
	104	if (tp->t_rawq.c_cc == 0) {
	105	if (tp->t_state & TS_NBIO) {
	106	u.u_error = EWOULDBLOCK;
	107	return;
	108	}
	109	sleep((caddr_t)&tp->t_rawq, TTIPRI);
	110	goto again;
	111	}
	112	while (tp->t_rawq.c_cc > 1 && uio->uio_resid > 0)
	113	if (ureadc(getc(&tp->t_rawq), uio) < 0) {
	114	u.u_error = EFAULT;
	115	break;
	116	}
	117	if (tp->t_rawq.c_cc == 1)
	118	(void) getc(&tp->t_rawq);
	119	if (tp->t_rawq.c_cc)
	120	return;
	121	} else
	122	if (tp->t_oproc)
	123	(*linesw[tp->t_line].l_read)(tp, uio);
	124	wakeup((caddr_t)&tp->t_rawq.c_cf);
	125	if (pti->pt_selw) {
	126	selwakeup(pti->pt_selw, pti->pt_flags & PF_WCOLL);
	127	pti->pt_selw = 0;
	128	pti->pt_flags &= ~PF_WCOLL;
	129	}
	130	}
	131
	132	/*
	133	* Write to pseudo-tty.
	134	* Wakeups of controlling tty will happen
	135	* indirectly, when tty driver calls ptsstart.
	136	*/
	137	ptswrite(dev, uio)
	138	dev_t dev;
	139	struct uio *uio;
	140	{
	141	register struct tty *tp;
	142
	143	tp = &pt_tty[minor(dev)];
	144	if (tp->t_oproc)
	145	(*linesw[tp->t_line].l_write)(tp, uio);
	146	}
	147
	148	/*
	149	* Start output on pseudo-tty.
	150	* Wake up process selecting or sleeping for input from controlling tty.
	151	*/
	152	ptsstart(tp)
	153	struct tty *tp;
	154	{
	155	register struct pt_ioctl *pti = &pt_ioctl[minor(tp->t_dev)];
	156
	157	if (tp->t_state & TS_TTSTOP)
	158	return;
	159	if (pti->pt_flags & PF_STOPPED) {
	160	pti->pt_flags &= ~PF_STOPPED;
	161	pti->pt_send = TIOCPKT_START;
	162	}
	163	ptcwakeup(tp);
	164	}
	165
	166	ptcwakeup(tp)
	167	struct tty *tp;
	168	{
	169	struct pt_ioctl *pti = &pt_ioctl[minor(tp->t_dev)];
	170
	171	if (pti->pt_selr) {
	172	selwakeup(pti->pt_selr, pti->pt_flags & PF_RCOLL);
	173	pti->pt_selr = 0;
	174	pti->pt_flags &= ~PF_RCOLL;
	175	}
	176	wakeup((caddr_t)&tp->t_outq.c_cf);
	177	}
	178
	179	/ARGSUSED/
	180	ptcopen(dev, flag)
	181	dev_t dev;
	182	int flag;
	183	{
	184	register struct tty *tp;
	185	struct pt_ioctl *pti;
	186
	187	if (minor(dev) >= NPTY) {
	188	u.u_error = ENXIO;
	189	return;
	190	}
	191	tp = &pt_tty[minor(dev)];
	192	if (tp->t_oproc) {
	193	u.u_error = EIO;
	194	return;
	195	}
	196	tp->t_oproc = ptsstart;
	197	if (tp->t_state & TS_WOPEN)
	198	wakeup((caddr_t)&tp->t_rawq);
	199	tp->t_state \|= TS_CARR_ON;
	200	pti = &pt_ioctl[minor(dev)];
	201	pti->pt_flags = 0;
	202	pti->pt_send = 0;
	203	}
	204
	205	ptcclose(dev)
	206	dev_t dev;
	207	{
	208	register struct tty *tp;
	209
	210	tp = &pt_tty[minor(dev)];
	211	if (tp->t_state & TS_ISOPEN)
	212	gsignal(tp->t_pgrp, SIGHUP);
	213	tp->t_state &= ~TS_CARR_ON; /* virtual carrier gone */
	214	flushtty(tp, FREAD\|FWRITE);
	215	tp->t_oproc = 0; /* mark closed */
	216	}
	217
	218	ptcread(dev, uio)
	219	dev_t dev;
	220	struct uio *uio;
	221	{
	222	register struct tty *tp;
	223	struct pt_ioctl *pti;
	224
	225	tp = &pt_tty[minor(dev)];
	226	if ((tp->t_state&(TS_CARR_ON\|TS_ISOPEN)) == 0)
	227	return;
	228	pti = &pt_ioctl[minor(dev)];
	229	if (pti->pt_flags & PF_PKT) {
	230	if (pti->pt_send) {
	231	(void) ureadc(pti->pt_send, uio);
	232	pti->pt_send = 0;
	233	return;
	234	}
	235	(void) ureadc(0, uio);
	236	}
	237	while (tp->t_outq.c_cc == 0 \|\| (tp->t_state&TS_TTSTOP)) {
	238	if (pti->pt_flags&PF_NBIO) {
	239	u.u_error = EWOULDBLOCK;
	240	return;
	241	}
	242	sleep((caddr_t)&tp->t_outq.c_cf, TTIPRI);
	243	}
	244	while (tp->t_outq.c_cc && uio->uio_resid > 0)
	245	if (ureadc(getc(&tp->t_outq), uio) < 0) {
	246	u.u_error = EFAULT;
	247	break;
	248	}
	249	if (tp->t_outq.c_cc <= TTLOWAT(tp)) {
	250	if (tp->t_state&TS_ASLEEP) {
	251	tp->t_state &= ~TS_ASLEEP;
	252	wakeup((caddr_t)&tp->t_outq);
	253	}
	254	if (tp->t_wsel) {
	255	selwakeup(tp->t_wsel, tp->t_state & TS_WCOLL);
	256	tp->t_wsel = 0;
	257	tp->t_state &= ~TS_WCOLL;
	258	}
	259	}
	260	}
	261
	262	ptsstop(tp, flush)
	263	register struct tty *tp;
	264	int flush;
	265	{
	266	struct pt_ioctl *pti = &pt_ioctl[minor(tp->t_dev)];
	267
	268	/* note: FLUSHREAD and FLUSHWRITE already ok */
	269	if (flush == 0) {
	270	flush = TIOCPKT_STOP;
	271	pti->pt_flags \|= PF_STOPPED;
	272	} else {
	273	pti->pt_flags &= ~PF_STOPPED;
	274	}
	275	pti->pt_send \|= flush;
	276	ptcwakeup(tp);
	277	}
	278
	279	ptcselect(dev, rw)
	280	dev_t dev;
	281	int rw;
	282	{
	283	register struct tty *tp = &pt_tty[minor(dev)];
	284	struct pt_ioctl *pti = &pt_ioctl[minor(dev)];
	285	struct proc *p;
	286	int s;
	287
	288	if ((tp->t_state&(TS_CARR_ON\|TS_ISOPEN)) == 0)
	289	return (1);
	290	s = spl5();
	291	switch (rw) {
	292
	293	case FREAD:
	294	if (tp->t_outq.c_cc && (tp->t_state&TS_TTSTOP) == 0) {
	295	splx(s);
	296	return (1);
	297	}
	298	if ((p = pti->pt_selr) && p->p_wchan == (caddr_t)&selwait)
	299	pti->pt_flags \|= PF_RCOLL;
	300	else
	301	pti->pt_selr = u.u_procp;
	302	break;
	303
	304	case FWRITE:
	305	if ((pti->pt_flags & PF_REMOTE) == 0 \|\| tp->t_rawq.c_cc == 0) {
	306	splx(s);
	307	return (1);
	308	}
	309	if ((p = pti->pt_selw) && p->p_wchan == (caddr_t)&selwait)
	310	pti->pt_flags \|= PF_WCOLL;
	311	else
	312	pti->pt_selw = u.u_procp;
	313	break;
	314	}
	315	splx(s);
	316	return (0);
	317	}
	318
	319	ptcwrite(dev, uio)
	320	dev_t dev;
	321	struct uio *uio;
	322	{
	323	register struct tty *tp;
	324	register char cp, ce;
	325	register int cc;
	326	char locbuf[BUFSIZ];
	327	int cnt = 0;
	328	struct pt_ioctl *pti = &pt_ioctl[minor(dev)];
	329
	330	tp = &pt_tty[minor(dev)];
	331	if ((tp->t_state&(TS_CARR_ON\|TS_ISOPEN)) == 0)
	332	return;
	333	do {
	334	register struct iovec *iov;
	335
	336	if (uio->uio_iovcnt == 0)
	337	break;
	338	iov = uio->uio_iov;
	339	if (iov->iov_len == 0) {
	340	uio->uio_iovcnt--;
	341	uio->uio_iov++;
	342	if (uio->uio_iovcnt < 0)
	343	panic("ptcwrite");
	344	continue;
	345	}
	346	cc = MIN(iov->iov_len, BUFSIZ);
	347	cp = locbuf;
	348	u.u_error = uiomove(cp, cc, UIO_WRITE, uio);
	349	if (u.u_error)
	350	break;
	351	ce = cp + cc;
	352	again:
	353	if (pti->pt_flags & PF_REMOTE) {
	354	if (tp->t_rawq.c_cc) {
	355	if (pti->pt_flags & PF_NBIO) {
	356	iov->iov_base -= ce - cp;
	357	iov->iov_len += ce - cp;
	358	uio->uio_resid += ce - cp;
	359	uio->uio_offset -= ce - cp;
	360	u.u_error = EWOULDBLOCK;
	361	return;
	362	}
	363	sleep((caddr_t)&tp->t_rawq.c_cf, TTOPRI);
	364	goto again;
	365	}
	366	(void) b_to_q(cp, cc, &tp->t_rawq);
	367	(void) putc(0, &tp->t_rawq);
	368	wakeup((caddr_t)&tp->t_rawq);
	369	return;
	370	}
	371	while (cp < ce) {
	372	while (tp->t_delct && tp->t_rawq.c_cc >= TTYHOG - 2) {
	373	wakeup((caddr_t)&tp->t_rawq);
	374	if (tp->t_state & TS_NBIO) {
	375	iov->iov_base -= ce - cp;
	376	iov->iov_len += ce - cp;
	377	uio->uio_resid += ce - cp;
	378	uio->uio_offset -= ce - cp;
	379	if (cnt == 0)
	380	u.u_error = EWOULDBLOCK;
	381	return;
	382	}
	383	/* Better than just flushing it! */
	384	/* Wait for something to be read */
	385	sleep((caddr_t)&tp->t_rawq.c_cf, TTOPRI);
	386	goto again;
	387	}
	388	(linesw[tp->t_line].l_rint)(cp++, tp);
	389	cnt++;
	390	}
	391	} while (uio->uio_resid);
	392	}
	393
	394	/ARGSUSED/
	395	ptyioctl(dev, cmd, data, flag)
	396	caddr_t data;
	397	dev_t dev;
	398	{
	399	register struct tty *tp = &pt_tty[minor(dev)];
	400	register struct pt_ioctl *pti = &pt_ioctl[minor(dev)];
	401
	402	/* IF CONTROLLER STTY THEN MUST FLUSH TO PREVENT A HANG ??? */
	403	if (cdevsw[major(dev)].d_open == ptcopen)
	404	switch (cmd) {
	405
	406	case TIOCPKT:
	407	if ((int )data)
	408	pti->pt_flags \|= PF_PKT;
	409	else
	410	pti->pt_flags &= ~PF_PKT;
	411	return;
	412
	413	case TIOCREMOTE:
	414	if ((int )data)
	415	pti->pt_flags \|= PF_REMOTE;
	416	else
	417	pti->pt_flags &= ~PF_REMOTE;
	418	flushtty(tp, FREAD\|FWRITE);
	419	return;
	420
	421	case FIONBIO:
	422	if ((int )data)
	423	pti->pt_flags \|= PF_NBIO;
	424	else
	425	pti->pt_flags &= ~PF_NBIO;
	426	return;
	427
	428	case TIOCSETP:
	429	while (getc(&tp->t_outq) >= 0)
	430	;
	431	break;
	432	}
	433	if (ttioctl(tp, cmd, data, dev) == 0)
	434	u.u_error = ENOTTY;
	435	{ int stop = (tp->t_un.t_chr.t_stopc == ('s'&037) &&
	436	tp->t_un.t_chr.t_startc == ('q'&037));
	437	if (pti->pt_flags & PF_NOSTOP) {
	438	if (stop) {
	439	pti->pt_send &= TIOCPKT_NOSTOP;
	440	pti->pt_send \|= TIOCPKT_DOSTOP;
	441	pti->pt_flags &= ~PF_NOSTOP;
	442	ptcwakeup(tp);
	443	}
	444	} else {
	445	if (stop == 0) {
	446	pti->pt_send &= ~TIOCPKT_DOSTOP;
	447	pti->pt_send \|= TIOCPKT_NOSTOP;
	448	pti->pt_flags \|= PF_NOSTOP;
	449	ptcwakeup(tp);
	450	}
	451	}
	452	}
	453	}
	454	#endif