xref: /openbsd-src/sys/kern/tty_pty.c (revision 8500990981f885cbe5e6a4958549cacc238b5ae6)
1 /*	$OpenBSD: tty_pty.c,v 1.16 2003/10/03 16:44:51 miod Exp $	*/
2 /*	$NetBSD: tty_pty.c,v 1.33.4.1 1996/06/02 09:08:11 mrg Exp $	*/
3 
4 /*
5  * Copyright (c) 1982, 1986, 1989, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  *	@(#)tty_pty.c	8.4 (Berkeley) 2/20/95
33  */
34 
35 /*
36  * Pseudo-teletype Driver
37  * (Actually two drivers, requiring two entries in 'cdevsw')
38  */
39 
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/ioctl.h>
43 #include <sys/proc.h>
44 #include <sys/tty.h>
45 #include <sys/file.h>
46 #include <sys/uio.h>
47 #include <sys/kernel.h>
48 #include <sys/malloc.h>
49 #include <sys/vnode.h>
50 #include <sys/signalvar.h>
51 #include <sys/uio.h>
52 #include <sys/conf.h>
53 #include <sys/poll.h>
54 
55 #define BUFSIZ 100		/* Chunk size iomoved to/from user */
56 
57 /*
58  * pts == /dev/tty[pqrs]?
59  * ptc == /dev/pty[pqrs]?
60  */
61 struct	pt_softc {
62 	struct	tty *pt_tty;
63 	int	pt_flags;
64 	struct	selinfo pt_selr, pt_selw;
65 	u_char	pt_send;
66 	u_char	pt_ucntl;
67 } *pt_softc;
68 int	npty;
69 
70 #define	PF_PKT		0x08		/* packet mode */
71 #define	PF_STOPPED	0x10		/* user told stopped */
72 #define	PF_REMOTE	0x20		/* remote and flow controlled input */
73 #define	PF_NOSTOP	0x40
74 #define PF_UCNTL	0x80		/* user control mode */
75 
76 void	ptyattach(int);
77 void	ptcwakeup(struct tty *, int);
78 struct tty *ptytty(dev_t);
79 void	ptsstart(struct tty *);
80 
81 void	filt_ptcrdetach(struct knote *);
82 int	filt_ptcread(struct knote *, long);
83 void	filt_ptcwdetach(struct knote *);
84 int	filt_ptcwrite(struct knote *, long);
85 
86 /*
87  * Establish n (or default if n is 1) ptys in the system.
88  */
89 void
90 ptyattach(n)
91 	int n;
92 {
93 #define	DEFAULT_NPTY	32
94 
95 	/* maybe should allow 0 => none? */
96 	if (n <= 1)
97 		n = DEFAULT_NPTY;
98 	pt_softc = malloc(n * sizeof(struct pt_softc), M_DEVBUF, M_WAITOK);
99 	bzero(pt_softc, n * sizeof(struct pt_softc));
100 	npty = n;
101 }
102 
103 /*ARGSUSED*/
104 int
105 ptsopen(dev, flag, devtype, p)
106 	dev_t dev;
107 	int flag, devtype;
108 	struct proc *p;
109 {
110 	struct pt_softc *pti;
111 	register struct tty *tp;
112 	int error;
113 
114 	if (minor(dev) >= npty)
115 		return (ENXIO);
116 	pti = &pt_softc[minor(dev)];
117 	if (!pti->pt_tty) {
118 		tp = pti->pt_tty = ttymalloc();
119 	} else
120 		tp = pti->pt_tty;
121 	if ((tp->t_state & TS_ISOPEN) == 0) {
122 		tp->t_state |= TS_WOPEN;
123 		ttychars(tp);		/* Set up default chars */
124 		tp->t_iflag = TTYDEF_IFLAG;
125 		tp->t_oflag = TTYDEF_OFLAG;
126 		tp->t_lflag = TTYDEF_LFLAG;
127 		tp->t_cflag = TTYDEF_CFLAG;
128 		tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
129 		ttsetwater(tp);		/* would be done in xxparam() */
130 	} else if (tp->t_state&TS_XCLUDE && p->p_ucred->cr_uid != 0)
131 		return (EBUSY);
132 	if (tp->t_oproc)			/* Ctrlr still around. */
133 		tp->t_state |= TS_CARR_ON;
134 	while ((tp->t_state & TS_CARR_ON) == 0) {
135 		tp->t_state |= TS_WOPEN;
136 		if (flag&FNONBLOCK)
137 			break;
138 		error = ttysleep(tp, &tp->t_rawq, TTIPRI | PCATCH,
139 				 ttopen, 0);
140 		if (error)
141 			return (error);
142 	}
143 	error = (*linesw[tp->t_line].l_open)(dev, tp);
144 	ptcwakeup(tp, FREAD|FWRITE);
145 	return (error);
146 }
147 
148 int
149 ptsclose(dev, flag, mode, p)
150 	dev_t dev;
151 	int flag, mode;
152 	struct proc *p;
153 {
154 	register struct pt_softc *pti = &pt_softc[minor(dev)];
155 	register struct tty *tp = pti->pt_tty;
156 	int error;
157 
158 	error = (*linesw[tp->t_line].l_close)(tp, flag);
159 	error |= ttyclose(tp);
160 	ptcwakeup(tp, FREAD|FWRITE);
161 	return (error);
162 }
163 
164 int
165 ptsread(dev, uio, flag)
166 	dev_t dev;
167 	struct uio *uio;
168 	int flag;
169 {
170 	struct proc *p = curproc;
171 	register struct pt_softc *pti = &pt_softc[minor(dev)];
172 	register struct tty *tp = pti->pt_tty;
173 	int error = 0;
174 
175 again:
176 	if (pti->pt_flags & PF_REMOTE) {
177 		while (isbackground(p, tp)) {
178 			if ((p->p_sigignore & sigmask(SIGTTIN)) ||
179 			    (p->p_sigmask & sigmask(SIGTTIN)) ||
180 			    p->p_pgrp->pg_jobc == 0 ||
181 			    p->p_flag & P_PPWAIT)
182 				return (EIO);
183 			pgsignal(p->p_pgrp, SIGTTIN, 1);
184 			error = ttysleep(tp, &lbolt,
185 					 TTIPRI | PCATCH, ttybg, 0);
186 			if (error)
187 				return (error);
188 		}
189 		if (tp->t_canq.c_cc == 0) {
190 			if (flag & IO_NDELAY)
191 				return (EWOULDBLOCK);
192 			error = ttysleep(tp, &tp->t_canq,
193 					 TTIPRI | PCATCH, ttyin, 0);
194 			if (error)
195 				return (error);
196 			goto again;
197 		}
198 		while (tp->t_canq.c_cc > 1 && uio->uio_resid > 0)
199 			if (ureadc(getc(&tp->t_canq), uio) < 0) {
200 				error = EFAULT;
201 				break;
202 			}
203 		if (tp->t_canq.c_cc == 1)
204 			(void) getc(&tp->t_canq);
205 		if (tp->t_canq.c_cc)
206 			return (error);
207 	} else
208 		if (tp->t_oproc)
209 			error = (*linesw[tp->t_line].l_read)(tp, uio, flag);
210 	ptcwakeup(tp, FWRITE);
211 	return (error);
212 }
213 
214 /*
215  * Write to pseudo-tty.
216  * Wakeups of controlling tty will happen
217  * indirectly, when tty driver calls ptsstart.
218  */
219 int
220 ptswrite(dev, uio, flag)
221 	dev_t dev;
222 	struct uio *uio;
223 	int flag;
224 {
225 	register struct pt_softc *pti = &pt_softc[minor(dev)];
226 	register struct tty *tp = pti->pt_tty;
227 
228 	if (tp->t_oproc == 0)
229 		return (EIO);
230 	return ((*linesw[tp->t_line].l_write)(tp, uio, flag));
231 }
232 
233 /*
234  * Start output on pseudo-tty.
235  * Wake up process polling or sleeping for input from controlling tty.
236  */
237 void
238 ptsstart(tp)
239 	struct tty *tp;
240 {
241 	register struct pt_softc *pti = &pt_softc[minor(tp->t_dev)];
242 
243 	if (tp->t_state & TS_TTSTOP)
244 		return;
245 	if (pti->pt_flags & PF_STOPPED) {
246 		pti->pt_flags &= ~PF_STOPPED;
247 		pti->pt_send = TIOCPKT_START;
248 	}
249 	ptcwakeup(tp, FREAD);
250 }
251 
252 int
253 ptsstop(tp, flush)
254 	register struct tty *tp;
255 	int flush;
256 {
257 	struct pt_softc *pti = &pt_softc[minor(tp->t_dev)];
258 	int flag;
259 
260 	/* note: FLUSHREAD and FLUSHWRITE already ok */
261 	if (flush == 0) {
262 		flush = TIOCPKT_STOP;
263 		pti->pt_flags |= PF_STOPPED;
264 	} else
265 		pti->pt_flags &= ~PF_STOPPED;
266 	pti->pt_send |= flush;
267 	/* change of perspective */
268 	flag = 0;
269 	if (flush & FREAD)
270 		flag |= FWRITE;
271 	if (flush & FWRITE)
272 		flag |= FREAD;
273 	ptcwakeup(tp, flag);
274 	return 0;
275 }
276 
277 void
278 ptcwakeup(tp, flag)
279 	struct tty *tp;
280 	int flag;
281 {
282 	struct pt_softc *pti = &pt_softc[minor(tp->t_dev)];
283 
284 	if (flag & FREAD) {
285 		selwakeup(&pti->pt_selr);
286 		wakeup(&tp->t_outq.c_cf);
287 		KNOTE(&pti->pt_selr.si_note, 0);
288 	}
289 	if (flag & FWRITE) {
290 		selwakeup(&pti->pt_selw);
291 		wakeup(&tp->t_rawq.c_cf);
292 		KNOTE(&pti->pt_selw.si_note, 0);
293 	}
294 }
295 
296 int ptcopen(dev_t, int, int, struct proc *);
297 
298 /*ARGSUSED*/
299 int
300 ptcopen(dev, flag, devtype, p)
301 	dev_t dev;
302 	int flag, devtype;
303 	struct proc *p;
304 {
305 	struct pt_softc *pti;
306 	register struct tty *tp;
307 
308 	if (minor(dev) >= npty)
309 		return (ENXIO);
310 	pti = &pt_softc[minor(dev)];
311 	if (!pti->pt_tty) {
312 		tp = pti->pt_tty = ttymalloc();
313 	} else
314 		tp = pti->pt_tty;
315 	if (tp->t_oproc)
316 		return (EIO);
317 	tp->t_oproc = ptsstart;
318 	(void)(*linesw[tp->t_line].l_modem)(tp, 1);
319 	tp->t_lflag &= ~EXTPROC;
320 	pti->pt_flags = 0;
321 	pti->pt_send = 0;
322 	pti->pt_ucntl = 0;
323 	return (0);
324 }
325 
326 /*ARGSUSED*/
327 int
328 ptcclose(dev, flag, devtype, p)
329 	dev_t dev;
330 	int flag, devtype;
331 	struct proc *p;
332 {
333 	register struct pt_softc *pti = &pt_softc[minor(dev)];
334 	register struct tty *tp = pti->pt_tty;
335 
336 	(void)(*linesw[tp->t_line].l_modem)(tp, 0);
337 	tp->t_state &= ~TS_CARR_ON;
338 	tp->t_oproc = 0;		/* mark closed */
339 	return (0);
340 }
341 
342 int
343 ptcread(dev, uio, flag)
344 	dev_t dev;
345 	struct uio *uio;
346 	int flag;
347 {
348 	register struct pt_softc *pti = &pt_softc[minor(dev)];
349 	register struct tty *tp = pti->pt_tty;
350 	char buf[BUFSIZ];
351 	int error = 0, cc;
352 
353 	/*
354 	 * We want to block until the slave
355 	 * is open, and there's something to read;
356 	 * but if we lost the slave or we're NBIO,
357 	 * then return the appropriate error instead.
358 	 */
359 	for (;;) {
360 		if (tp->t_state&TS_ISOPEN) {
361 			if (pti->pt_flags&PF_PKT && pti->pt_send) {
362 				error = ureadc((int)pti->pt_send, uio);
363 				if (error)
364 					return (error);
365 				if (pti->pt_send & TIOCPKT_IOCTL) {
366 					cc = min(uio->uio_resid,
367 						sizeof(tp->t_termios));
368 					uiomove(&tp->t_termios, cc, uio);
369 				}
370 				pti->pt_send = 0;
371 				return (0);
372 			}
373 			if (pti->pt_flags&PF_UCNTL && pti->pt_ucntl) {
374 				error = ureadc((int)pti->pt_ucntl, uio);
375 				if (error)
376 					return (error);
377 				pti->pt_ucntl = 0;
378 				return (0);
379 			}
380 			if (tp->t_outq.c_cc && (tp->t_state&TS_TTSTOP) == 0)
381 				break;
382 		}
383 		if ((tp->t_state&TS_CARR_ON) == 0)
384 			return (0);	/* EOF */
385 		if (flag & IO_NDELAY)
386 			return (EWOULDBLOCK);
387 		error = tsleep(&tp->t_outq.c_cf, TTIPRI | PCATCH,
388 			       ttyin, 0);
389 		if (error)
390 			return (error);
391 	}
392 	if (pti->pt_flags & (PF_PKT|PF_UCNTL))
393 		error = ureadc(0, uio);
394 	while (uio->uio_resid > 0 && error == 0) {
395 		cc = q_to_b(&tp->t_outq, buf, min(uio->uio_resid, BUFSIZ));
396 		if (cc <= 0)
397 			break;
398 		error = uiomove(buf, cc, uio);
399 	}
400 	if (tp->t_outq.c_cc <= tp->t_lowat) {
401 		if (tp->t_state&TS_ASLEEP) {
402 			tp->t_state &= ~TS_ASLEEP;
403 			wakeup(&tp->t_outq);
404 		}
405 		selwakeup(&tp->t_wsel);
406 	}
407 	return (error);
408 }
409 
410 
411 int
412 ptcwrite(dev, uio, flag)
413 	dev_t dev;
414 	register struct uio *uio;
415 	int flag;
416 {
417 	register struct pt_softc *pti = &pt_softc[minor(dev)];
418 	register struct tty *tp = pti->pt_tty;
419 	register u_char *cp = NULL;
420 	register int cc = 0;
421 	u_char locbuf[BUFSIZ];
422 	int cnt = 0;
423 	int error = 0;
424 
425 again:
426 	if ((tp->t_state&TS_ISOPEN) == 0)
427 		goto block;
428 	if (pti->pt_flags & PF_REMOTE) {
429 		if (tp->t_canq.c_cc)
430 			goto block;
431 		while (uio->uio_resid > 0 && tp->t_canq.c_cc < TTYHOG - 1) {
432 			if (cc == 0) {
433 				cc = min(uio->uio_resid, BUFSIZ);
434 				cc = min(cc, TTYHOG - 1 - tp->t_canq.c_cc);
435 				cp = locbuf;
436 				error = uiomove(cp, cc, uio);
437 				if (error)
438 					return (error);
439 				/* check again for safety */
440 				if ((tp->t_state&TS_ISOPEN) == 0)
441 					return (EIO);
442 			}
443 			if (cc)
444 				(void) b_to_q((char *)cp, cc, &tp->t_canq);
445 			cc = 0;
446 		}
447 		(void) putc(0, &tp->t_canq);
448 		ttwakeup(tp);
449 		wakeup(&tp->t_canq);
450 		return (0);
451 	}
452 	while (uio->uio_resid > 0) {
453 		if (cc == 0) {
454 			cc = min(uio->uio_resid, BUFSIZ);
455 			cp = locbuf;
456 			error = uiomove(cp, cc, uio);
457 			if (error)
458 				return (error);
459 			/* check again for safety */
460 			if ((tp->t_state&TS_ISOPEN) == 0)
461 				return (EIO);
462 		}
463 		while (cc > 0) {
464 			if ((tp->t_rawq.c_cc + tp->t_canq.c_cc) >= TTYHOG - 2 &&
465 			   (tp->t_canq.c_cc > 0 || !ISSET(tp->t_lflag, ICANON))) {
466 				wakeup(&tp->t_rawq);
467 				goto block;
468 			}
469 			(*linesw[tp->t_line].l_rint)(*cp++, tp);
470 			cnt++;
471 			cc--;
472 		}
473 		cc = 0;
474 	}
475 	return (0);
476 block:
477 	/*
478 	 * Come here to wait for slave to open, for space
479 	 * in outq, or space in rawq.
480 	 */
481 	if ((tp->t_state&TS_CARR_ON) == 0)
482 		return (EIO);
483 	if (flag & IO_NDELAY) {
484 		/* adjust for data copied in but not written */
485 		uio->uio_resid += cc;
486 		if (cnt == 0)
487 			return (EWOULDBLOCK);
488 		return (0);
489 	}
490 	error = tsleep(&tp->t_rawq.c_cf, TTOPRI | PCATCH,
491 		       ttyout, 0);
492 	if (error) {
493 		/* adjust for data copied in but not written */
494 		uio->uio_resid += cc;
495 		return (error);
496 	}
497 	goto again;
498 }
499 
500 int
501 ptcpoll(dev_t dev, int events, struct proc *p)
502 {
503 	struct pt_softc *pti = &pt_softc[minor(dev)];
504 	struct tty *tp = pti->pt_tty;
505 	int revents = 0, s;
506 
507 	if (!ISSET(tp->t_state, TS_CARR_ON))
508 		return (POLLHUP);
509 
510 	if (!ISSET(tp->t_state, TS_ISOPEN))
511 		goto notopen;
512 
513 	if (events & (POLLIN | POLLRDNORM)) {
514 		/*
515 		 * Need to protect access to t_outq
516 		 */
517 		s = spltty();
518 		if ((tp->t_outq.c_cc && !ISSET(tp->t_state, TS_TTSTOP)) ||
519 		     ((pti->pt_flags & PF_PKT) && pti->pt_send) ||
520 		     ((pti->pt_flags & PF_UCNTL) && pti->pt_ucntl))
521 			revents |= events & (POLLIN | POLLRDNORM);
522 		splx(s);
523 	}
524 	if (events & (POLLOUT | POLLWRNORM)) {
525 		if ((pti->pt_flags & PF_REMOTE) ?
526 		     (tp->t_canq.c_cc == 0) :
527 		     ((tp->t_rawq.c_cc + tp->t_canq.c_cc < TTYHOG - 2) ||
528 		      (tp->t_canq.c_cc == 0 && ISSET(tp->t_lflag, ICANON))))
529 			revents |= events & (POLLOUT | POLLWRNORM);
530 	}
531 	if (events & (POLLPRI | POLLRDBAND)) {
532 		/* If in packet or user control mode, check for data. */
533 		if (((pti->pt_flags & PF_PKT) && pti->pt_send) ||
534 		     ((pti->pt_flags & PF_UCNTL) && pti->pt_ucntl))
535 			revents |= events & (POLLPRI | POLLRDBAND);
536 	}
537 
538 	if (revents == 0) {
539 notopen:
540 		if (events & (POLLIN | POLLPRI | POLLRDNORM | POLLRDBAND))
541 			selrecord(p, &pti->pt_selr);
542 		if (events & (POLLOUT | POLLWRNORM))
543 			selrecord(p, &pti->pt_selw);
544 	}
545 
546 	return (revents);
547 }
548 
549 void
550 filt_ptcrdetach(struct knote *kn)
551 {
552 	struct pt_softc *pti = (struct pt_softc *)kn->kn_hook;
553 	int s;
554 
555 	s = spltty();
556 	SLIST_REMOVE(&pti->pt_selr.si_note, kn, knote, kn_selnext);
557 	splx(s);
558 }
559 
560 int
561 filt_ptcread(struct knote *kn, long hint)
562 {
563 	struct pt_softc *pti = (struct pt_softc *)kn->kn_hook;
564 	struct tty *tp;
565 
566 	tp = pti->pt_tty;
567 	kn->kn_data = 0;
568 
569 	if (ISSET(tp->t_state, TS_ISOPEN)) {
570 		if (!ISSET(tp->t_state, TS_TTSTOP))
571 			kn->kn_data = tp->t_outq.c_cc;
572 		if (((pti->pt_flags & PF_PKT) && pti->pt_send) ||
573 		    ((pti->pt_flags & PF_UCNTL) && pti->pt_ucntl))
574 			kn->kn_data++;
575 	}
576 	return (kn->kn_data > 0);
577 }
578 
579 void
580 filt_ptcwdetach(struct knote *kn)
581 {
582 	struct pt_softc *pti = (struct pt_softc *)kn->kn_hook;
583 	int s;
584 
585 	s = spltty();
586 	SLIST_REMOVE(&pti->pt_selw.si_note, kn, knote, kn_selnext);
587 	splx(s);
588 }
589 
590 int
591 filt_ptcwrite(struct knote *kn, long hint)
592 {
593 	struct pt_softc *pti = (struct pt_softc *)kn->kn_hook;
594 	struct tty *tp;
595 
596 	tp = pti->pt_tty;
597 	kn->kn_data = 0;
598 
599 	if (ISSET(tp->t_state, TS_ISOPEN)) {
600 		if (ISSET(pti->pt_flags, PF_REMOTE)) {
601 			if (tp->t_canq.c_cc == 0)
602 				kn->kn_data = tp->t_canq.c_cn;
603 		} else if (tp->t_rawq.c_cc + tp->t_canq.c_cc < TTYHOG-2)
604 			kn->kn_data = tp->t_canq.c_cn -
605 			    (tp->t_rawq.c_cc + tp->t_canq.c_cc);
606 	}
607 
608 	return (kn->kn_data > 0);
609 }
610 
611 struct filterops ptcread_filtops =
612 	{ 1, NULL, filt_ptcrdetach, filt_ptcread };
613 struct filterops ptcwrite_filtops =
614 	{ 1, NULL, filt_ptcwdetach, filt_ptcwrite };
615 
616 int
617 ptckqfilter(dev_t dev, struct knote *kn)
618 {
619 	struct pt_softc *pti = &pt_softc[minor(dev)];
620 	struct klist *klist;
621 	int s;
622 
623 	switch (kn->kn_filter) {
624 	case EVFILT_READ:
625 		klist = &pti->pt_selr.si_note;
626 		kn->kn_fop = &ptcread_filtops;
627 		break;
628 	case EVFILT_WRITE:
629 		klist = &pti->pt_selw.si_note;
630 		kn->kn_fop = &ptcwrite_filtops;
631 		break;
632 	default:
633 		return (1);
634 	}
635 
636 	kn->kn_hook = (caddr_t)pti;
637 
638 	s = spltty();
639 	SLIST_INSERT_HEAD(klist, kn, kn_selnext);
640 	splx(s);
641 
642 	return (0);
643 }
644 
645 struct tty *
646 ptytty(dev)
647 	dev_t dev;
648 {
649 	register struct pt_softc *pti = &pt_softc[minor(dev)];
650 	register struct tty *tp = pti->pt_tty;
651 
652 	return (tp);
653 }
654 
655 /*ARGSUSED*/
656 int
657 ptyioctl(dev, cmd, data, flag, p)
658 	dev_t dev;
659 	u_long cmd;
660 	caddr_t data;
661 	int flag;
662 	struct proc *p;
663 {
664 	register struct pt_softc *pti = &pt_softc[minor(dev)];
665 	register struct tty *tp = pti->pt_tty;
666 	register u_char *cc = tp->t_cc;
667 	int stop, error;
668 
669 	/*
670 	 * IF CONTROLLER STTY THEN MUST FLUSH TO PREVENT A HANG.
671 	 * ttywflush(tp) will hang if there are characters in the outq.
672 	 */
673 	if (cmd == TIOCEXT) {
674 		/*
675 		 * When the EXTPROC bit is being toggled, we need
676 		 * to send an TIOCPKT_IOCTL if the packet driver
677 		 * is turned on.
678 		 */
679 		if (*(int *)data) {
680 			if (pti->pt_flags & PF_PKT) {
681 				pti->pt_send |= TIOCPKT_IOCTL;
682 				ptcwakeup(tp, FREAD);
683 			}
684 			tp->t_lflag |= EXTPROC;
685 		} else {
686 			if ((tp->t_lflag & EXTPROC) &&
687 			    (pti->pt_flags & PF_PKT)) {
688 				pti->pt_send |= TIOCPKT_IOCTL;
689 				ptcwakeup(tp, FREAD);
690 			}
691 			tp->t_lflag &= ~EXTPROC;
692 		}
693 		return(0);
694 	} else
695 	if (cdevsw[major(dev)].d_open == ptcopen)
696 		switch (cmd) {
697 
698 		case TIOCGPGRP:
699 #ifdef COMPAT_SUNOS
700 			{
701 			/*
702 			 * I'm not sure about SunOS TIOCGPGRP semantics
703 			 * on PTYs, but it's something like this:
704 			 */
705 			extern struct emul emul_sunos;
706 			if (p->p_emul == &emul_sunos && tp->t_pgrp == 0)
707 				return (EIO);
708 			*(int *)data = tp->t_pgrp->pg_id;
709 			return (0);
710 			}
711 #endif
712 			/*
713 			 * We aviod calling ttioctl on the controller since,
714 			 * in that case, tp must be the controlling terminal.
715 			 */
716 			*(int *)data = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
717 			return (0);
718 
719 		case TIOCPKT:
720 			if (*(int *)data) {
721 				if (pti->pt_flags & PF_UCNTL)
722 					return (EINVAL);
723 				pti->pt_flags |= PF_PKT;
724 			} else
725 				pti->pt_flags &= ~PF_PKT;
726 			return (0);
727 
728 		case TIOCUCNTL:
729 			if (*(int *)data) {
730 				if (pti->pt_flags & PF_PKT)
731 					return (EINVAL);
732 				pti->pt_flags |= PF_UCNTL;
733 			} else
734 				pti->pt_flags &= ~PF_UCNTL;
735 			return (0);
736 
737 		case TIOCREMOTE:
738 			if (*(int *)data)
739 				pti->pt_flags |= PF_REMOTE;
740 			else
741 				pti->pt_flags &= ~PF_REMOTE;
742 			ttyflush(tp, FREAD|FWRITE);
743 			return (0);
744 
745 #ifdef COMPAT_OLDTTY
746 		case TIOCSETP:
747 		case TIOCSETN:
748 #endif
749 		case TIOCSETD:
750 		case TIOCSETA:
751 		case TIOCSETAW:
752 		case TIOCSETAF:
753 			ndflush(&tp->t_outq, tp->t_outq.c_cc);
754 			break;
755 
756 		case TIOCSIG:
757 			if (*(unsigned int *)data >= NSIG)
758 				return(EINVAL);
759 			if ((tp->t_lflag&NOFLSH) == 0)
760 				ttyflush(tp, FREAD|FWRITE);
761 			pgsignal(tp->t_pgrp, *(unsigned int *)data, 1);
762 			if ((*(unsigned int *)data == SIGINFO) &&
763 			    ((tp->t_lflag&NOKERNINFO) == 0))
764 				ttyinfo(tp);
765 			return(0);
766 		}
767 	error = (*linesw[tp->t_line].l_ioctl)(tp, cmd, data, flag, p);
768 	if (error < 0)
769 		 error = ttioctl(tp, cmd, data, flag, p);
770 	if (error < 0) {
771 		if (pti->pt_flags & PF_UCNTL &&
772 		    (cmd & ~0xff) == UIOCCMD(0)) {
773 			if (cmd & 0xff) {
774 				pti->pt_ucntl = (u_char)cmd;
775 				ptcwakeup(tp, FREAD);
776 			}
777 			return (0);
778 		}
779 		error = ENOTTY;
780 	}
781 	/*
782 	 * If external processing and packet mode send ioctl packet.
783 	 */
784 	if ((tp->t_lflag&EXTPROC) && (pti->pt_flags & PF_PKT)) {
785 		switch(cmd) {
786 		case TIOCSETA:
787 		case TIOCSETAW:
788 		case TIOCSETAF:
789 #ifdef COMPAT_OLDTTY
790 		case TIOCSETP:
791 		case TIOCSETN:
792 		case TIOCSETC:
793 		case TIOCSLTC:
794 		case TIOCLBIS:
795 		case TIOCLBIC:
796 		case TIOCLSET:
797 #endif
798 			pti->pt_send |= TIOCPKT_IOCTL;
799 			ptcwakeup(tp, FREAD);
800 		default:
801 			break;
802 		}
803 	}
804 	stop = (tp->t_iflag & IXON) && CCEQ(cc[VSTOP], CTRL('s'))
805 		&& CCEQ(cc[VSTART], CTRL('q'));
806 	if (pti->pt_flags & PF_NOSTOP) {
807 		if (stop) {
808 			pti->pt_send &= ~TIOCPKT_NOSTOP;
809 			pti->pt_send |= TIOCPKT_DOSTOP;
810 			pti->pt_flags &= ~PF_NOSTOP;
811 			ptcwakeup(tp, FREAD);
812 		}
813 	} else {
814 		if (!stop) {
815 			pti->pt_send &= ~TIOCPKT_DOSTOP;
816 			pti->pt_send |= TIOCPKT_NOSTOP;
817 			pti->pt_flags |= PF_NOSTOP;
818 			ptcwakeup(tp, FREAD);
819 		}
820 	}
821 	return (error);
822 }
823