pty.c revision 131114
1/*
2 * Copyright (c) 1982, 1986, 1989, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 4. Neither the name of the University nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 *	@(#)tty_pty.c	8.4 (Berkeley) 2/20/95
30 */
31
32#include <sys/cdefs.h>
33__FBSDID("$FreeBSD: head/sys/kern/tty_pty.c 131114 2004-06-25 21:54:49Z phk $");
34
35/*
36 * Pseudo-teletype Driver
37 * (Actually two drivers, requiring two entries in 'cdevsw')
38 */
39#include "opt_compat.h"
40#include "opt_tty.h"
41#include <sys/param.h>
42#include <sys/systm.h>
43#include <sys/lock.h>
44#include <sys/mutex.h>
45#include <sys/sx.h>
46#ifndef BURN_BRIDGES
47#if defined(COMPAT_43)
48#include <sys/ioctl_compat.h>
49#endif
50#endif
51#include <sys/proc.h>
52#include <sys/tty.h>
53#include <sys/conf.h>
54#include <sys/fcntl.h>
55#include <sys/poll.h>
56#include <sys/kernel.h>
57#include <sys/vnode.h>
58#include <sys/signalvar.h>
59#include <sys/malloc.h>
60
61static MALLOC_DEFINE(M_PTY, "ptys", "pty data structures");
62
63static void ptsstart(struct tty *tp);
64static void ptsstop(struct tty *tp, int rw);
65static void ptcwakeup(struct tty *tp, int flag);
66static struct cdev *ptyinit(struct cdev *cdev);
67
68static	d_open_t	ptsopen;
69static	d_close_t	ptsclose;
70static	d_read_t	ptsread;
71static	d_write_t	ptswrite;
72static	d_ioctl_t	ptyioctl;
73static	d_open_t	ptcopen;
74static	d_close_t	ptcclose;
75static	d_read_t	ptcread;
76static	d_write_t	ptcwrite;
77static	d_poll_t	ptcpoll;
78
79#define	CDEV_MAJOR_S	5
80static struct cdevsw pts_cdevsw = {
81	.d_version =	D_VERSION,
82	.d_open =	ptsopen,
83	.d_close =	ptsclose,
84	.d_read =	ptsread,
85	.d_write =	ptswrite,
86	.d_ioctl =	ptyioctl,
87	.d_name =	"pts",
88	.d_maj =	CDEV_MAJOR_S,
89	.d_flags =	D_TTY | D_NEEDGIANT,
90};
91
92#define	CDEV_MAJOR_C	6
93static struct cdevsw ptc_cdevsw = {
94	.d_version =	D_VERSION,
95	.d_open =	ptcopen,
96	.d_close =	ptcclose,
97	.d_read =	ptcread,
98	.d_write =	ptcwrite,
99	.d_ioctl =	ptyioctl,
100	.d_poll =	ptcpoll,
101	.d_name =	"ptc",
102	.d_maj =	CDEV_MAJOR_C,
103	.d_flags =	D_TTY | D_NEEDGIANT,
104};
105
106#define BUFSIZ 100		/* Chunk size iomoved to/from user */
107
108struct	ptsc {
109	int	pt_flags;
110	struct	selinfo pt_selr, pt_selw;
111	u_char	pt_send;
112	u_char	pt_ucntl;
113	struct tty *pt_tty;
114	struct cdev *devs, *devc;
115	struct	prison *pt_prison;
116};
117
118#define	PF_PKT		0x08		/* packet mode */
119#define	PF_STOPPED	0x10		/* user told stopped */
120#define	PF_NOSTOP	0x40
121#define PF_UCNTL	0x80		/* user control mode */
122
123#define	TSA_PTC_READ(tp)	((void *)&(tp)->t_outq.c_cf)
124#define	TSA_PTC_WRITE(tp)	((void *)&(tp)->t_rawq.c_cl)
125#define	TSA_PTS_READ(tp)	((void *)&(tp)->t_canq)
126
127static char *names = "pqrsPQRS";
128/*
129 * This function creates and initializes a pts/ptc pair
130 *
131 * pts == /dev/tty[pqrsPQRS][0123456789abcdefghijklmnopqrstuv]
132 * ptc == /dev/pty[pqrsPQRS][0123456789abcdefghijklmnopqrstuv]
133 *
134 * XXX: define and add mapping of upper minor bits to allow more
135 *      than 256 ptys.
136 */
137static struct cdev *
138ptyinit(struct cdev *devc)
139{
140	struct cdev *devs;
141	struct ptsc *pt;
142	int n;
143
144	n = minor(devc);
145	/* For now we only map the lower 8 bits of the minor */
146	if (n & ~0xff)
147		return (NULL);
148
149	devc->si_flags &= ~SI_CHEAPCLONE;
150
151	pt = malloc(sizeof(*pt), M_PTY, M_WAITOK | M_ZERO);
152	pt->devs = devs = make_dev(&pts_cdevsw, n,
153	    UID_ROOT, GID_WHEEL, 0666, "tty%c%r", names[n / 32], n % 32);
154	pt->devc = devc;
155
156	pt->pt_tty = ttymalloc(pt->pt_tty);
157	devs->si_drv1 = devc->si_drv1 = pt;
158	devs->si_tty = devc->si_tty = pt->pt_tty;
159	pt->pt_tty->t_dev = devs;
160	return (devc);
161}
162
163/*ARGSUSED*/
164static	int
165ptsopen(struct cdev *dev, int flag, int devtype, struct thread *td)
166{
167	struct tty *tp;
168	int error;
169	struct ptsc *pt;
170
171	if (!dev->si_drv1)
172		return(ENXIO);
173	pt = dev->si_drv1;
174	tp = dev->si_tty;
175	if ((tp->t_state & TS_ISOPEN) == 0) {
176		ttychars(tp);		/* Set up default chars */
177		tp->t_iflag = TTYDEF_IFLAG;
178		tp->t_oflag = TTYDEF_OFLAG;
179		tp->t_lflag = TTYDEF_LFLAG;
180		tp->t_cflag = TTYDEF_CFLAG;
181		tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
182	} else if (tp->t_state & TS_XCLUDE && suser(td))
183		return (EBUSY);
184	else if (pt->pt_prison != td->td_ucred->cr_prison)
185		return (EBUSY);
186	if (tp->t_oproc)			/* Ctrlr still around. */
187		(void)ttyld_modem(tp, 1);
188	while ((tp->t_state & TS_CARR_ON) == 0) {
189		if (flag&FNONBLOCK)
190			break;
191		error = ttysleep(tp, TSA_CARR_ON(tp), TTIPRI | PCATCH,
192				 "ptsopn", 0);
193		if (error)
194			return (error);
195	}
196	error = ttyld_open(tp, dev);
197	if (error == 0)
198		ptcwakeup(tp, FREAD|FWRITE);
199	return (error);
200}
201
202static	int
203ptsclose(struct cdev *dev, int flag, int mode, struct thread *td)
204{
205	struct tty *tp;
206	int err;
207
208	tp = dev->si_tty;
209	err = ttyld_close(tp, flag);
210	(void) ttyclose(tp);
211	return (err);
212}
213
214static	int
215ptsread(struct cdev *dev, struct uio *uio, int flag)
216{
217	struct thread *td = curthread;
218	struct proc *p = td->td_proc;
219	struct tty *tp = dev->si_tty;
220	struct ptsc *pt = dev->si_drv1;
221	struct pgrp *pg;
222	int error = 0;
223
224again:
225	if (tp->t_oproc)
226		error = ttyld_read(tp, uio, flag);
227	ptcwakeup(tp, FWRITE);
228	return (error);
229}
230
231/*
232 * Write to pseudo-tty.
233 * Wakeups of controlling tty will happen
234 * indirectly, when tty driver calls ptsstart.
235 */
236static	int
237ptswrite(struct cdev *dev, struct uio *uio, int flag)
238{
239	struct tty *tp;
240
241	tp = dev->si_tty;
242	if (tp->t_oproc == 0)
243		return (EIO);
244	return (ttyld_write(tp, uio, flag));
245}
246
247/*
248 * Start output on pseudo-tty.
249 * Wake up process selecting or sleeping for input from controlling tty.
250 */
251static void
252ptsstart(struct tty *tp)
253{
254	struct ptsc *pt = tp->t_dev->si_drv1;
255
256	if (tp->t_state & TS_TTSTOP)
257		return;
258	if (pt->pt_flags & PF_STOPPED) {
259		pt->pt_flags &= ~PF_STOPPED;
260		pt->pt_send = TIOCPKT_START;
261	}
262	ptcwakeup(tp, FREAD);
263}
264
265static void
266ptcwakeup(struct tty *tp, int flag)
267{
268	struct ptsc *pt = tp->t_dev->si_drv1;
269
270	if (flag & FREAD) {
271		selwakeuppri(&pt->pt_selr, TTIPRI);
272		wakeup(TSA_PTC_READ(tp));
273	}
274	if (flag & FWRITE) {
275		selwakeuppri(&pt->pt_selw, TTOPRI);
276		wakeup(TSA_PTC_WRITE(tp));
277	}
278}
279
280static	int
281ptcopen(struct cdev *dev, int flag, int devtype, struct thread *td)
282{
283	struct tty *tp;
284	struct ptsc *pt;
285
286	if (!dev->si_drv1)
287		ptyinit(dev);
288	if (!dev->si_drv1)
289		return(ENXIO);
290	tp = dev->si_tty;
291	if (tp->t_oproc)
292		return (EIO);
293	tp->t_timeout = -1;
294	tp->t_oproc = ptsstart;
295	tp->t_stop = ptsstop;
296	(void)ttyld_modem(tp, 1);
297	tp->t_lflag &= ~EXTPROC;
298	pt = dev->si_drv1;
299	pt->pt_prison = td->td_ucred->cr_prison;
300	pt->pt_flags = 0;
301	pt->pt_send = 0;
302	pt->pt_ucntl = 0;
303	return (0);
304}
305
306static	int
307ptcclose(struct cdev *dev, int flags, int fmt, struct thread *td)
308{
309	struct tty *tp;
310
311	tp = dev->si_tty;
312	(void)ttyld_modem(tp, 0);
313
314	/*
315	 * XXX MDMBUF makes no sense for ptys but would inhibit the above
316	 * l_modem().  CLOCAL makes sense but isn't supported.   Special
317	 * l_modem()s that ignore carrier drop make no sense for ptys but
318	 * may be in use because other parts of the line discipline make
319	 * sense for ptys.  Recover by doing everything that a normal
320	 * ttymodem() would have done except for sending a SIGHUP.
321	 */
322	if (tp->t_state & TS_ISOPEN) {
323		tp->t_state &= ~(TS_CARR_ON | TS_CONNECTED);
324		tp->t_state |= TS_ZOMBIE;
325		ttyflush(tp, FREAD | FWRITE);
326	}
327
328	tp->t_oproc = 0;		/* mark closed */
329	return (0);
330}
331
332static	int
333ptcread(struct cdev *dev, struct uio *uio, int flag)
334{
335	struct tty *tp = dev->si_tty;
336	struct ptsc *pt = dev->si_drv1;
337	char buf[BUFSIZ];
338	int error = 0, cc;
339
340	/*
341	 * We want to block until the slave
342	 * is open, and there's something to read;
343	 * but if we lost the slave or we're NBIO,
344	 * then return the appropriate error instead.
345	 */
346	for (;;) {
347		if (tp->t_state&TS_ISOPEN) {
348			if (pt->pt_flags&PF_PKT && pt->pt_send) {
349				error = ureadc((int)pt->pt_send, uio);
350				if (error)
351					return (error);
352				if (pt->pt_send & TIOCPKT_IOCTL) {
353					cc = min(uio->uio_resid,
354						sizeof(tp->t_termios));
355					uiomove(&tp->t_termios, cc, uio);
356				}
357				pt->pt_send = 0;
358				return (0);
359			}
360			if (pt->pt_flags&PF_UCNTL && pt->pt_ucntl) {
361				error = ureadc((int)pt->pt_ucntl, uio);
362				if (error)
363					return (error);
364				pt->pt_ucntl = 0;
365				return (0);
366			}
367			if (tp->t_outq.c_cc && (tp->t_state&TS_TTSTOP) == 0)
368				break;
369		}
370		if ((tp->t_state & TS_CONNECTED) == 0)
371			return (0);	/* EOF */
372		if (flag & IO_NDELAY)
373			return (EWOULDBLOCK);
374		error = tsleep(TSA_PTC_READ(tp), TTIPRI | PCATCH, "ptcin", 0);
375		if (error)
376			return (error);
377	}
378	if (pt->pt_flags & (PF_PKT|PF_UCNTL))
379		error = ureadc(0, uio);
380	while (uio->uio_resid > 0 && error == 0) {
381		cc = q_to_b(&tp->t_outq, buf, min(uio->uio_resid, BUFSIZ));
382		if (cc <= 0)
383			break;
384		error = uiomove(buf, cc, uio);
385	}
386	ttwwakeup(tp);
387	return (error);
388}
389
390static	void
391ptsstop(struct tty *tp, int flush)
392{
393	struct ptsc *pt = tp->t_dev->si_drv1;
394	int flag;
395
396	/* note: FLUSHREAD and FLUSHWRITE already ok */
397	if (flush == 0) {
398		flush = TIOCPKT_STOP;
399		pt->pt_flags |= PF_STOPPED;
400	} else
401		pt->pt_flags &= ~PF_STOPPED;
402	pt->pt_send |= flush;
403	/* change of perspective */
404	flag = 0;
405	if (flush & FREAD)
406		flag |= FWRITE;
407	if (flush & FWRITE)
408		flag |= FREAD;
409	ptcwakeup(tp, flag);
410}
411
412static	int
413ptcpoll(struct cdev *dev, int events, struct thread *td)
414{
415	struct tty *tp = dev->si_tty;
416	struct ptsc *pt = dev->si_drv1;
417	int revents = 0;
418	int s;
419
420	if ((tp->t_state & TS_CONNECTED) == 0)
421		return (events &
422		   (POLLHUP | POLLIN | POLLRDNORM | POLLOUT | POLLWRNORM));
423
424	/*
425	 * Need to block timeouts (ttrstart).
426	 */
427	s = spltty();
428
429	if (events & (POLLIN | POLLRDNORM))
430		if ((tp->t_state & TS_ISOPEN) &&
431		    ((tp->t_outq.c_cc && (tp->t_state & TS_TTSTOP) == 0) ||
432		     ((pt->pt_flags & PF_PKT) && pt->pt_send) ||
433		     ((pt->pt_flags & PF_UCNTL) && pt->pt_ucntl)))
434			revents |= events & (POLLIN | POLLRDNORM);
435
436	if (events & (POLLOUT | POLLWRNORM))
437		if (tp->t_state & TS_ISOPEN &&
438		    (((tp->t_rawq.c_cc + tp->t_canq.c_cc < TTYHOG - 2) ||
439		      (tp->t_canq.c_cc == 0 && (tp->t_lflag & ICANON)))))
440			revents |= events & (POLLOUT | POLLWRNORM);
441
442	if (events & POLLHUP)
443		if ((tp->t_state & TS_CARR_ON) == 0)
444			revents |= POLLHUP;
445
446	if (revents == 0) {
447		if (events & (POLLIN | POLLRDNORM))
448			selrecord(td, &pt->pt_selr);
449
450		if (events & (POLLOUT | POLLWRNORM))
451			selrecord(td, &pt->pt_selw);
452	}
453	splx(s);
454
455	return (revents);
456}
457
458static	int
459ptcwrite(struct cdev *dev, struct uio *uio, int flag)
460{
461	struct tty *tp = dev->si_tty;
462	u_char *cp = 0;
463	int cc = 0;
464	u_char locbuf[BUFSIZ];
465	int cnt = 0;
466	struct ptsc *pt = dev->si_drv1;
467	int error = 0;
468
469again:
470	if ((tp->t_state&TS_ISOPEN) == 0)
471		goto block;
472	while (uio->uio_resid > 0 || cc > 0) {
473		if (cc == 0) {
474			cc = min(uio->uio_resid, BUFSIZ);
475			cp = locbuf;
476			error = uiomove(cp, cc, uio);
477			if (error)
478				return (error);
479			/* check again for safety */
480			if ((tp->t_state & TS_ISOPEN) == 0) {
481				/* adjust for data copied in but not written */
482				uio->uio_resid += cc;
483				return (EIO);
484			}
485		}
486		while (cc > 0) {
487			if ((tp->t_rawq.c_cc + tp->t_canq.c_cc) >= TTYHOG - 2 &&
488			   (tp->t_canq.c_cc > 0 || !(tp->t_lflag&ICANON))) {
489				wakeup(TSA_HUP_OR_INPUT(tp));
490				goto block;
491			}
492			ttyld_rint(tp, *cp++);
493			cnt++;
494			cc--;
495		}
496		cc = 0;
497	}
498	return (0);
499block:
500	/*
501	 * Come here to wait for slave to open, for space
502	 * in outq, or space in rawq, or an empty canq.
503	 */
504	if ((tp->t_state & TS_CONNECTED) == 0) {
505		/* adjust for data copied in but not written */
506		uio->uio_resid += cc;
507		return (EIO);
508	}
509	if (flag & IO_NDELAY) {
510		/* adjust for data copied in but not written */
511		uio->uio_resid += cc;
512		if (cnt == 0)
513			return (EWOULDBLOCK);
514		return (0);
515	}
516	error = tsleep(TSA_PTC_WRITE(tp), TTOPRI | PCATCH, "ptcout", 0);
517	if (error) {
518		/* adjust for data copied in but not written */
519		uio->uio_resid += cc;
520		return (error);
521	}
522	goto again;
523}
524
525/*ARGSUSED*/
526static	int
527ptyioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag, struct thread *td)
528{
529	struct tty *tp = dev->si_tty;
530	struct ptsc *pt = dev->si_drv1;
531	u_char *cc = tp->t_cc;
532	int stop, error;
533
534	if (devsw(dev)->d_open == ptcopen) {
535		switch (cmd) {
536
537		case TIOCGPGRP:
538			/*
539			 * We avoid calling ttioctl on the controller since,
540			 * in that case, tp must be the controlling terminal.
541			 */
542			*(int *)data = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
543			return (0);
544
545		case TIOCPKT:
546			if (*(int *)data) {
547				if (pt->pt_flags & PF_UCNTL)
548					return (EINVAL);
549				pt->pt_flags |= PF_PKT;
550			} else
551				pt->pt_flags &= ~PF_PKT;
552			return (0);
553
554		case TIOCUCNTL:
555			if (*(int *)data) {
556				if (pt->pt_flags & PF_PKT)
557					return (EINVAL);
558				pt->pt_flags |= PF_UCNTL;
559			} else
560				pt->pt_flags &= ~PF_UCNTL;
561			return (0);
562		}
563
564		/*
565		 * The rest of the ioctls shouldn't be called until
566		 * the slave is open.
567		 */
568		if ((tp->t_state & TS_ISOPEN) == 0)
569			return (EAGAIN);
570
571		switch (cmd) {
572#ifndef BURN_BRIDGES
573#ifdef COMPAT_43
574		case TIOCSETP:
575		case TIOCSETN:
576#endif
577#endif
578		case TIOCSETD:
579		case TIOCSETA:
580		case TIOCSETAW:
581		case TIOCSETAF:
582			/*
583			 * IF CONTROLLER STTY THEN MUST FLUSH TO PREVENT A HANG.
584			 * ttywflush(tp) will hang if there are characters in
585			 * the outq.
586			 */
587			ndflush(&tp->t_outq, tp->t_outq.c_cc);
588			break;
589
590		case TIOCSIG:
591			if (*(unsigned int *)data >= NSIG ||
592			    *(unsigned int *)data == 0)
593				return(EINVAL);
594			if ((tp->t_lflag&NOFLSH) == 0)
595				ttyflush(tp, FREAD|FWRITE);
596			if (tp->t_pgrp != NULL) {
597				PGRP_LOCK(tp->t_pgrp);
598				pgsignal(tp->t_pgrp, *(unsigned int *)data, 1);
599				PGRP_UNLOCK(tp->t_pgrp);
600			}
601			if ((*(unsigned int *)data == SIGINFO) &&
602			    ((tp->t_lflag&NOKERNINFO) == 0))
603				ttyinfo(tp);
604			return(0);
605		}
606	}
607	if (cmd == TIOCEXT) {
608		/*
609		 * When the EXTPROC bit is being toggled, we need
610		 * to send an TIOCPKT_IOCTL if the packet driver
611		 * is turned on.
612		 */
613		if (*(int *)data) {
614			if (pt->pt_flags & PF_PKT) {
615				pt->pt_send |= TIOCPKT_IOCTL;
616				ptcwakeup(tp, FREAD);
617			}
618			tp->t_lflag |= EXTPROC;
619		} else {
620			if ((tp->t_lflag & EXTPROC) &&
621			    (pt->pt_flags & PF_PKT)) {
622				pt->pt_send |= TIOCPKT_IOCTL;
623				ptcwakeup(tp, FREAD);
624			}
625			tp->t_lflag &= ~EXTPROC;
626		}
627		return(0);
628	}
629	error = ttyioctl(dev, cmd, data, flag, td);
630	if (error == ENOTTY) {
631		if (pt->pt_flags & PF_UCNTL &&
632		    (cmd & ~0xff) == UIOCCMD(0)) {
633			if (cmd & 0xff) {
634				pt->pt_ucntl = (u_char)cmd;
635				ptcwakeup(tp, FREAD);
636			}
637			return (0);
638		}
639		error = ENOTTY;
640	}
641	/*
642	 * If external processing and packet mode send ioctl packet.
643	 */
644	if ((tp->t_lflag&EXTPROC) && (pt->pt_flags & PF_PKT)) {
645		switch(cmd) {
646		case TIOCSETA:
647		case TIOCSETAW:
648		case TIOCSETAF:
649#ifndef BURN_BRIDGES
650#ifdef COMPAT_43
651		case TIOCSETP:
652		case TIOCSETN:
653		case TIOCSETC:
654		case TIOCSLTC:
655		case TIOCLBIS:
656		case TIOCLBIC:
657		case TIOCLSET:
658#endif
659#endif
660			pt->pt_send |= TIOCPKT_IOCTL;
661			ptcwakeup(tp, FREAD);
662			break;
663		default:
664			break;
665		}
666	}
667	stop = (tp->t_iflag & IXON) && CCEQ(cc[VSTOP], CTRL('s'))
668		&& CCEQ(cc[VSTART], CTRL('q'));
669	if (pt->pt_flags & PF_NOSTOP) {
670		if (stop) {
671			pt->pt_send &= ~TIOCPKT_NOSTOP;
672			pt->pt_send |= TIOCPKT_DOSTOP;
673			pt->pt_flags &= ~PF_NOSTOP;
674			ptcwakeup(tp, FREAD);
675		}
676	} else {
677		if (!stop) {
678			pt->pt_send &= ~TIOCPKT_DOSTOP;
679			pt->pt_send |= TIOCPKT_NOSTOP;
680			pt->pt_flags |= PF_NOSTOP;
681			ptcwakeup(tp, FREAD);
682		}
683	}
684	return (error);
685}
686
687static void
688pty_clone(void *arg, char *name, int namelen, struct cdev **dev)
689{
690	int u;
691
692	if (*dev != NULL)
693		return;
694	if (bcmp(name, "pty", 3) != 0)
695		return;
696	if (name[5] != '\0')
697		return;
698	switch (name[3]) {
699	case 'p': u =   0; break;
700	case 'q': u =  32; break;
701	case 'r': u =  64; break;
702	case 's': u =  96; break;
703	case 'P': u = 128; break;
704	case 'Q': u = 160; break;
705	case 'R': u = 192; break;
706	case 'S': u = 224; break;
707	default: return;
708	}
709	if (name[4] >= '0' && name[4] <= '9')
710		u += name[4] - '0';
711	else if (name[4] >= 'a' && name[4] <= 'v')
712		u += name[4] - 'a' + 10;
713	else
714		return;
715	*dev = make_dev(&ptc_cdevsw, u,
716	    UID_ROOT, GID_WHEEL, 0666, "pty%c%r", names[u / 32], u % 32);
717	(*dev)->si_flags |= SI_CHEAPCLONE;
718	return;
719}
720
721static void
722ptc_drvinit(void *unused)
723{
724
725	EVENTHANDLER_REGISTER(dev_clone, pty_clone, 0, 1000);
726}
727
728SYSINIT(ptcdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR_C,ptc_drvinit,NULL)
729