xref: /netbsd-src/sys/kern/tty_pty.c (revision 811e6386f8c5e4a3521c7003da29ec8673e344fa)
1 /*
2  * Copyright (c) 1982, 1986, 1989 The Regents of the University of California.
3  * 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  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *	@(#)tty_pty.c	7.21 (Berkeley) 5/30/91
34  *
35  * PATCHES MAGIC                LEVEL   PATCH THAT GOT US HERE
36  * --------------------         -----   ----------------------
37  * CURRENT PATCH LEVEL:         5       00094
38  * --------------------         -----   ----------------------
39  *
40  * 11 Dec 92	Williams Jolitz		Fixed tty handling
41  *
42  * 28 Nov 1991	Warren Toomey		Cleaned up the use of COMPAT_43
43  *					in the 386BSD kernel.
44  * 6 Oct 1992	Holger Veit		Fixed 'hanging console' bug
45  * 11 Jan 93	Julian Elischer		Fixes multiple processes on one
46  *					pty bug
47  * 27 Feb 93	Charles Hannum		Proper return values for ptsclose()
48  *					and ptcclose()
49  */
50 static char rcsid[] = "$Header: /cvsroot/src/sys/kern/tty_pty.c,v 1.2 1993/03/21 18:04:42 cgd Exp $";
51 
52 /*
53  * Pseudo-teletype Driver
54  * (Actually two drivers, requiring two entries in 'cdevsw')
55  */
56 #include "pty.h"
57 
58 #if NPTY > 0
59 #include "param.h"
60 #include "systm.h"
61 #include "ioctl.h"
62 #include "tty.h"
63 #include "conf.h"
64 #include "file.h"
65 #include "proc.h"
66 #include "uio.h"
67 #include "kernel.h"
68 #include "vnode.h"
69 
70 #if NPTY == 1
71 #undef NPTY
72 #define	NPTY	32		/* crude XXX */
73 #endif
74 
75 #define BUFSIZ 100		/* Chunk size iomoved to/from user */
76 
77 /*
78  * pts == /dev/tty[pqrs]?
79  * ptc == /dev/pty[pqrs]?
80  */
81 struct	tty pt_tty[NPTY];
82 struct	pt_ioctl {
83 	int	pt_flags;
84 	pid_t	pt_selr, pt_selw;
85 	u_char	pt_send;
86 	u_char	pt_ucntl;
87 } pt_ioctl[NPTY];
88 int	npty = NPTY;		/* for pstat -t */
89 
90 #define	PF_RCOLL	0x01
91 #define	PF_WCOLL	0x02
92 #define	PF_PKT		0x08		/* packet mode */
93 #define	PF_STOPPED	0x10		/* user told stopped */
94 #define	PF_REMOTE	0x20		/* remote and flow controlled input */
95 #define	PF_NOSTOP	0x40
96 #define PF_UCNTL	0x80		/* user control mode */
97 
98 /*ARGSUSED*/
99 ptsopen(dev, flag, devtype, p)
100 	dev_t dev;
101 	struct proc *p;
102 {
103 	register struct tty *tp;
104 	int error;
105 
106 #ifdef lint
107 	npty = npty;
108 #endif
109 	if (minor(dev) >= NPTY)
110 		return (ENXIO);
111 	tp = &pt_tty[minor(dev)];
112 	if ((tp->t_state & TS_ISOPEN) == 0) {
113 		tp->t_state |= TS_WOPEN;
114 		ttychars(tp);		/* Set up default chars */
115 		tp->t_iflag = TTYDEF_IFLAG;
116 		tp->t_oflag = TTYDEF_OFLAG;
117 		tp->t_lflag = TTYDEF_LFLAG;
118 		tp->t_cflag = TTYDEF_CFLAG;
119 		tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
120 		ttsetwater(tp);		/* would be done in xxparam() */
121 	} else if (tp->t_state&TS_XCLUDE && p->p_ucred->cr_uid != 0)
122 		return (EBUSY);
123 	if (tp->t_oproc)			/* Ctrlr still around. */
124 		tp->t_state |= TS_CARR_ON;
125 	while ((tp->t_state & TS_CARR_ON) == 0) {
126 		tp->t_state |= TS_WOPEN;
127 		if (flag&FNONBLOCK)
128 			break;
129 		if (error = ttysleep(tp, (caddr_t)&tp->t_raw, TTIPRI | PCATCH,
130 		    ttopen, 0))
131 			return (error);
132 	}
133 	error = (*linesw[tp->t_line].l_open)(dev, tp, flag);
134 	ptcwakeup(tp, FREAD|FWRITE);
135 	return (error);
136 }
137 
138 ptsclose(dev, flag, mode, p)
139 	dev_t dev;
140 	int flag, mode;
141 	struct proc *p;
142 {
143 	register struct tty *tp;
144 
145 	tp = &pt_tty[minor(dev)];
146 	(*linesw[tp->t_line].l_close)(tp, flag);
147 	ttyclose(tp);
148 	ptcwakeup(tp, FREAD|FWRITE);
149 	return(0);
150 }
151 
152 ptsread(dev, uio, flag)
153 	dev_t dev;
154 	struct uio *uio;
155 {
156 	struct proc *p = curproc;
157 	register struct tty *tp = &pt_tty[minor(dev)];
158 	register struct pt_ioctl *pti = &pt_ioctl[minor(dev)];
159 	int error = 0;
160 
161 again:
162 	if (pti->pt_flags & PF_REMOTE) {
163 		while (isbackground(p, tp)) {
164 			if ((p->p_sigignore & sigmask(SIGTTIN)) ||
165 			    (p->p_sigmask & sigmask(SIGTTIN)) ||
166 			    p->p_pgrp->pg_jobc == 0 ||
167 			    p->p_flag&SPPWAIT)
168 				return (EIO);
169 			pgsignal(p->p_pgrp, SIGTTIN, 1);
170 			if (error = ttysleep(tp, (caddr_t)&lbolt,
171 			    TTIPRI | PCATCH, ttybg, 0))
172 				return (error);
173 		}
174 		if (RB_LEN(&tp->t_can) == 0) {
175 			if (flag & IO_NDELAY)
176 				return (EWOULDBLOCK);
177 			if (error = ttysleep(tp, (caddr_t)&tp->t_can,
178 			    TTIPRI | PCATCH, ttyin, 0))
179 				return (error);
180 			goto again;
181 		}
182 		while (RB_LEN(&tp->t_can) > 1 && uio->uio_resid > 0)
183 			if (ureadc(getc(&tp->t_can), uio) < 0) {
184 				error = EFAULT;
185 				break;
186 			}
187 		if (RB_LEN(&tp->t_can) == 1)
188 			(void) getc(&tp->t_can);
189 		if (RB_LEN(&tp->t_can))
190 			return (error);
191 	} else
192 		if (tp->t_oproc)
193 			error = (*linesw[tp->t_line].l_read)(tp, uio, flag);
194 	ptcwakeup(tp, FWRITE);
195 	return (error);
196 }
197 
198 /*
199  * Write to pseudo-tty.
200  * Wakeups of controlling tty will happen
201  * indirectly, when tty driver calls ptsstart.
202  */
203 ptswrite(dev, uio, flag)
204 	dev_t dev;
205 	struct uio *uio;
206 {
207 	register struct tty *tp;
208 
209 	tp = &pt_tty[minor(dev)];
210 	if (tp->t_oproc == 0)
211 		return (EIO);
212 	return ((*linesw[tp->t_line].l_write)(tp, uio, flag));
213 }
214 
215 /*
216  * Start output on pseudo-tty.
217  * Wake up process selecting or sleeping for input from controlling tty.
218  */
219 ptsstart(tp)
220 	struct tty *tp;
221 {
222 	register struct pt_ioctl *pti = &pt_ioctl[minor(tp->t_dev)];
223 
224 	if (tp->t_state & TS_TTSTOP)
225 		return;
226 	if (pti->pt_flags & PF_STOPPED) {
227 		pti->pt_flags &= ~PF_STOPPED;
228 		pti->pt_send = TIOCPKT_START;
229 	}
230 	ptcwakeup(tp, FREAD);
231 }
232 
233 ptcwakeup(tp, flag)
234 	struct tty *tp;
235 {
236 	struct pt_ioctl *pti = &pt_ioctl[minor(tp->t_dev)];
237 
238 	if (flag & FREAD) {
239 		if (pti->pt_selr) {
240 			selwakeup(pti->pt_selr, pti->pt_flags & PF_RCOLL);
241 			pti->pt_selr = 0;
242 			pti->pt_flags &= ~PF_RCOLL;
243 		}
244 		wakeup((caddr_t)&tp->t_out.rb_tl);
245 	}
246 	if (flag & FWRITE) {
247 		if (pti->pt_selw) {
248 			selwakeup(pti->pt_selw, pti->pt_flags & PF_WCOLL);
249 			pti->pt_selw = 0;
250 			pti->pt_flags &= ~PF_WCOLL;
251 		}
252 		wakeup((caddr_t)&tp->t_raw.rb_hd);
253 	}
254 }
255 
256 /*ARGSUSED*/
257 #ifdef __STDC__
258 ptcopen(dev_t dev, int flag, int devtype, struct proc *p)
259 #else
260 ptcopen(dev, flag, devtype, p)
261 	dev_t dev;
262 	int flag, devtype;
263 	struct proc *p;
264 #endif
265 {
266 	register struct tty *tp;
267 	struct pt_ioctl *pti;
268 
269 	if (minor(dev) >= NPTY)
270 		return (ENXIO);
271 	tp = &pt_tty[minor(dev)];
272 	if (tp->t_oproc)
273 		return (EIO);
274 	tp->t_oproc = ptsstart;
275 	(void)(*linesw[tp->t_line].l_modem)(tp, 1);
276 	tp->t_lflag &= ~EXTPROC;
277 	pti = &pt_ioctl[minor(dev)];
278 	pti->pt_flags = 0;
279 	pti->pt_send = 0;
280 	pti->pt_ucntl = 0;
281 	return (0);
282 }
283 
284 extern struct tty *constty;	/* -hv- 06.Oct.92*/
285 ptcclose(dev)
286 	dev_t dev;
287 {
288 	register struct tty *tp;
289 
290 	tp = &pt_tty[minor(dev)];
291 	(void)(*linesw[tp->t_line].l_modem)(tp, 0);
292 	tp->t_state &= ~TS_CARR_ON;
293 	tp->t_oproc = 0;		/* mark closed */
294 	tp->t_session = 0;
295 
296 /* XXX -hv- 6.Oct.92 this prevents the "hanging console bug" with X11 */
297 	if (constty==tp)
298 		constty = 0;
299 
300 	return (0);
301 }
302 
303 ptcread(dev, uio, flag)
304 	dev_t dev;
305 	struct uio *uio;
306 {
307 	register struct tty *tp = &pt_tty[minor(dev)];
308 	struct pt_ioctl *pti = &pt_ioctl[minor(dev)];
309 	char buf[BUFSIZ];
310 	int error = 0, cc;
311 
312 	/*
313 	 * We want to block until the slave
314 	 * is open, and there's something to read;
315 	 * but if we lost the slave or we're NBIO,
316 	 * then return the appropriate error instead.
317 	 */
318 	for (;;) {
319 		if (tp->t_state&TS_ISOPEN) {
320 			if (pti->pt_flags&PF_PKT && pti->pt_send) {
321 				error = ureadc((int)pti->pt_send, uio);
322 				if (error)
323 					return (error);
324 				if (pti->pt_send & TIOCPKT_IOCTL) {
325 					cc = MIN(uio->uio_resid,
326 						sizeof(tp->t_termios));
327 					uiomove(&tp->t_termios, cc, uio);
328 				}
329 				pti->pt_send = 0;
330 				return (0);
331 			}
332 			if (pti->pt_flags&PF_UCNTL && pti->pt_ucntl) {
333 				error = ureadc((int)pti->pt_ucntl, uio);
334 				if (error)
335 					return (error);
336 				pti->pt_ucntl = 0;
337 				return (0);
338 			}
339 			if (RB_LEN(&tp->t_out) && (tp->t_state&TS_TTSTOP) == 0)
340 				break;
341 		}
342 		if ((tp->t_state&TS_CARR_ON) == 0)
343 			return (0);	/* EOF */
344 		if (flag & IO_NDELAY)
345 			return (EWOULDBLOCK);
346 		if (error = tsleep((caddr_t)&tp->t_out.rb_tl, TTIPRI | PCATCH,
347 		    ttyin, 0))
348 			return (error);
349 	}
350 	if (pti->pt_flags & (PF_PKT|PF_UCNTL))
351 		error = ureadc(0, uio);
352 	while (uio->uio_resid > 0 && error == 0) {
353 #ifdef was
354 		cc = q_to_b(&tp->t_outq, buf, MIN(uio->uio_resid, BUFSIZ));
355 #else
356 		cc = min(MIN(uio->uio_resid, BUFSIZ), RB_CONTIGGET(&tp->t_out));
357 		if (cc) {
358 			bcopy(tp->t_out.rb_hd, buf, cc);
359 			tp->t_out.rb_hd =
360 				RB_ROLLOVER(&tp->t_out, tp->t_out.rb_hd+cc);
361 		}
362 #endif
363 		if (cc <= 0)
364 			break;
365 		error = uiomove(buf, cc, uio);
366 	}
367 	if (RB_LEN(&tp->t_out) <= tp->t_lowat) {
368 		if (tp->t_state&TS_ASLEEP) {
369 			tp->t_state &= ~TS_ASLEEP;
370 			wakeup((caddr_t)&tp->t_out);
371 		}
372 		if (tp->t_wsel) {
373 			selwakeup(tp->t_wsel, tp->t_state & TS_WCOLL);
374 			tp->t_wsel = 0;
375 			tp->t_state &= ~TS_WCOLL;
376 		}
377 	}
378 	return (error);
379 }
380 
381 ptsstop(tp, flush)
382 	register struct tty *tp;
383 	int flush;
384 {
385 	struct pt_ioctl *pti = &pt_ioctl[minor(tp->t_dev)];
386 	int flag;
387 
388 	/* note: FLUSHREAD and FLUSHWRITE already ok */
389 	if (flush == 0) {
390 		flush = TIOCPKT_STOP;
391 		pti->pt_flags |= PF_STOPPED;
392 	} else
393 		pti->pt_flags &= ~PF_STOPPED;
394 	pti->pt_send |= flush;
395 	/* change of perspective */
396 	flag = 0;
397 	if (flush & FREAD)
398 		flag |= FWRITE;
399 	if (flush & FWRITE)
400 		flag |= FREAD;
401 	ptcwakeup(tp, flag);
402 }
403 
404 ptcselect(dev, rw, p)
405 	dev_t dev;
406 	int rw;
407 	struct proc *p;
408 {
409 	register struct tty *tp = &pt_tty[minor(dev)];
410 	struct pt_ioctl *pti = &pt_ioctl[minor(dev)];
411 	struct proc *prev;
412 	int s;
413 
414 	if ((tp->t_state&TS_CARR_ON) == 0)
415 		return (1);
416 	switch (rw) {
417 
418 	case FREAD:
419 		/*
420 		 * Need to block timeouts (ttrstart).
421 		 */
422 		s = spltty();
423 		if ((tp->t_state&TS_ISOPEN) &&
424 		     RB_LEN(&tp->t_out) && (tp->t_state&TS_TTSTOP) == 0) {
425 			splx(s);
426 			return (1);
427 		}
428 		splx(s);
429 		/* FALLTHROUGH */
430 
431 	case 0:					/* exceptional */
432 		if ((tp->t_state&TS_ISOPEN) &&
433 		    (pti->pt_flags&PF_PKT && pti->pt_send ||
434 		     pti->pt_flags&PF_UCNTL && pti->pt_ucntl))
435 			return (1);
436 		if (pti->pt_selr && (prev = pfind(pti->pt_selr)) && prev->p_wchan == (caddr_t)&selwait)
437 			pti->pt_flags |= PF_RCOLL;
438 		else
439 			pti->pt_selr = p->p_pid;
440 		break;
441 
442 
443 	case FWRITE:
444 		if (tp->t_state&TS_ISOPEN) {
445 			if (pti->pt_flags & PF_REMOTE) {
446 			    if (RB_LEN(&tp->t_can) == 0)
447 				return (1);
448 			} else {
449 			    if (RB_LEN(&tp->t_raw) + RB_LEN(&tp->t_can) < TTYHOG-2)
450 				    return (1);
451 			    if (RB_LEN(&tp->t_can) == 0 && (tp->t_iflag&ICANON))
452 				    return (1);
453 			}
454 		}
455 		if (pti->pt_selw && (prev = pfind(pti->pt_selw)) && prev->p_wchan == (caddr_t)&selwait)
456 			pti->pt_flags |= PF_WCOLL;
457 		else
458 			pti->pt_selw = p->p_pid;
459 		break;
460 
461 	}
462 	return (0);
463 }
464 
465 ptcwrite(dev, uio, flag)
466 	dev_t dev;
467 	register struct uio *uio;
468 {
469 	register struct tty *tp = &pt_tty[minor(dev)];
470 	register u_char *cp;
471 	register int cc = 0;
472 	u_char locbuf[BUFSIZ];
473 	int cnt = 0;
474 	struct pt_ioctl *pti = &pt_ioctl[minor(dev)];
475 	int error = 0;
476 
477 again:
478 	if ((tp->t_state&TS_ISOPEN) == 0)
479 		goto block;
480 	if (pti->pt_flags & PF_REMOTE) {
481 		if (RB_LEN(&tp->t_can))
482 			goto block;
483 		while (uio->uio_resid > 0 && RB_LEN(&tp->t_can) < TTYHOG - 1) {
484 			if (cc == 0) {
485 				cc = min(uio->uio_resid, BUFSIZ);
486 				cc = min(cc, TTYHOG - 1 - RB_CONTIGPUT(&tp->t_can));
487 				cp = locbuf;
488 				error = uiomove((caddr_t)cp, cc, uio);
489 				if (error)
490 					return (error);
491 				/* check again for safety */
492 				if ((tp->t_state&TS_ISOPEN) == 0)
493 					return (EIO);
494 			}
495 #ifdef was
496 			if (cc)
497 				(void) b_to_q((char *)cp, cc, &tp->t_canq);
498 #else
499 			if (cc) {
500 				bcopy(cp, tp->t_can.rb_tl, cc);
501 				tp->t_can.rb_tl =
502 				  RB_ROLLOVER(&tp->t_can, tp->t_can.rb_tl+cc);
503 			}
504 #endif
505 			cc = 0;
506 		}
507 		(void) putc(0, &tp->t_can);
508 		ttwakeup(tp);
509 		wakeup((caddr_t)&tp->t_can);
510 		return (0);
511 	}
512 	while (uio->uio_resid > 0) {
513 		if (cc == 0) {
514 			cc = min(uio->uio_resid, BUFSIZ);
515 			cp = locbuf;
516 			error = uiomove((caddr_t)cp, cc, uio);
517 			if (error)
518 				return (error);
519 			/* check again for safety */
520 			if ((tp->t_state&TS_ISOPEN) == 0)
521 				return (EIO);
522 		}
523 		while (cc > 0) {
524 			if ((RB_LEN(&tp->t_raw) + RB_LEN(&tp->t_can)) >= TTYHOG - 2 &&
525 			   (RB_LEN(&tp->t_can) > 0 || !(tp->t_iflag&ICANON))) {
526 				wakeup((caddr_t)&tp->t_raw);
527 				goto block;
528 			}
529 			(*linesw[tp->t_line].l_rint)(*cp++, tp);
530 			cnt++;
531 			cc--;
532 		}
533 		cc = 0;
534 	}
535 	return (0);
536 block:
537 	/*
538 	 * Come here to wait for slave to open, for space
539 	 * in outq, or space in rawq.
540 	 */
541 	if ((tp->t_state&TS_CARR_ON) == 0)
542 		return (EIO);
543 	if (flag & IO_NDELAY) {
544 		/* adjust for data copied in but not written */
545 		uio->uio_resid += cc;
546 		if (cnt == 0)
547 			return (EWOULDBLOCK);
548 		return (0);
549 	}
550 	if (error = tsleep((caddr_t)&tp->t_raw.rb_hd, TTOPRI | PCATCH,
551 	    ttyout, 0)) {
552 		/* adjust for data copied in but not written */
553 		uio->uio_resid += cc;
554 		return (error);
555 	}
556 	goto again;
557 }
558 
559 /*ARGSUSED*/
560 ptyioctl(dev, cmd, data, flag)
561 	caddr_t data;
562 	dev_t dev;
563 {
564 	register struct tty *tp = &pt_tty[minor(dev)];
565 	register struct pt_ioctl *pti = &pt_ioctl[minor(dev)];
566 	register u_char *cc = tp->t_cc;
567 	int stop, error;
568 	extern ttyinput();
569 
570 	/*
571 	 * IF CONTROLLER STTY THEN MUST FLUSH TO PREVENT A HANG.
572 	 * ttywflush(tp) will hang if there are characters in the outq.
573 	 */
574 	if (cmd == TIOCEXT) {
575 		/*
576 		 * When the EXTPROC bit is being toggled, we need
577 		 * to send an TIOCPKT_IOCTL if the packet driver
578 		 * is turned on.
579 		 */
580 		if (*(int *)data) {
581 			if (pti->pt_flags & PF_PKT) {
582 				pti->pt_send |= TIOCPKT_IOCTL;
583 				ptcwakeup(tp, FREAD);
584 			}
585 			tp->t_lflag |= EXTPROC;
586 		} else {
587 			if ((tp->t_state & EXTPROC) &&
588 			    (pti->pt_flags & PF_PKT)) {
589 				pti->pt_send |= TIOCPKT_IOCTL;
590 				ptcwakeup(tp, FREAD);
591 			}
592 			tp->t_lflag &= ~EXTPROC;
593 		}
594 		return(0);
595 	} else
596 	if (cdevsw[major(dev)].d_open == ptcopen)
597 		switch (cmd) {
598 
599 		case TIOCGPGRP:
600 			/*
601 			 * We aviod calling ttioctl on the controller since,
602 			 * in that case, tp must be the controlling terminal.
603 			 */
604 			*(int *)data = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
605 			return (0);
606 
607 		case TIOCPKT:
608 			if (*(int *)data) {
609 				if (pti->pt_flags & PF_UCNTL)
610 					return (EINVAL);
611 				pti->pt_flags |= PF_PKT;
612 			} else
613 				pti->pt_flags &= ~PF_PKT;
614 			return (0);
615 
616 		case TIOCUCNTL:
617 			if (*(int *)data) {
618 				if (pti->pt_flags & PF_PKT)
619 					return (EINVAL);
620 				pti->pt_flags |= PF_UCNTL;
621 			} else
622 				pti->pt_flags &= ~PF_UCNTL;
623 			return (0);
624 
625 		case TIOCREMOTE:
626 			if (*(int *)data)
627 				pti->pt_flags |= PF_REMOTE;
628 			else
629 				pti->pt_flags &= ~PF_REMOTE;
630 			ttyflush(tp, FREAD|FWRITE);
631 			return (0);
632 
633 #ifdef COMPAT_43
634 	/* wkt */
635 		case TIOCSETP:
636 		case TIOCSETN:
637 #endif
638 		case TIOCSETD:
639 		case TIOCSETA:
640 		case TIOCSETAW:
641 		case TIOCSETAF:
642 			while (getc(&tp->t_out) >= 0)
643 				;
644 			break;
645 
646 		case TIOCSIG:
647 			if (*(unsigned int *)data >= NSIG)
648 				return(EINVAL);
649 			if ((tp->t_lflag&NOFLSH) == 0)
650 				ttyflush(tp, FREAD|FWRITE);
651 			pgsignal(tp->t_pgrp, *(unsigned int *)data, 1);
652 			if ((*(unsigned int *)data == SIGINFO) &&
653 			    ((tp->t_lflag&NOKERNINFO) == 0))
654 				ttyinfo(tp);
655 			return(0);
656 		}
657 	error = (*linesw[tp->t_line].l_ioctl)(tp, cmd, data, flag);
658 	if (error < 0)
659 		 error = ttioctl(tp, cmd, data, flag);
660 	/*
661 	 * Since we use the tty queues internally,
662 	 * pty's can't be switched to disciplines which overwrite
663 	 * the queues.  We can't tell anything about the discipline
664 	 * from here...
665 	 */
666 	if (linesw[tp->t_line].l_rint != ttyinput) {
667 		(*linesw[tp->t_line].l_close)(tp, flag);
668 		tp->t_line = TTYDISC;
669 		(void)(*linesw[tp->t_line].l_open)(dev, tp, flag);
670 		error = ENOTTY;
671 	}
672 	if (error < 0) {
673 		if (pti->pt_flags & PF_UCNTL &&
674 		    (cmd & ~0xff) == UIOCCMD(0)) {
675 			if (cmd & 0xff) {
676 				pti->pt_ucntl = (u_char)cmd;
677 				ptcwakeup(tp, FREAD);
678 			}
679 			return (0);
680 		}
681 		error = ENOTTY;
682 	}
683 	/*
684 	 * If external processing and packet mode send ioctl packet.
685 	 */
686 	if ((tp->t_lflag&EXTPROC) && (pti->pt_flags & PF_PKT)) {
687 		switch(cmd) {
688 		case TIOCSETA:
689 		case TIOCSETAW:
690 		case TIOCSETAF:
691 #ifdef	COMPAT_43
692 	/* wkt */
693 		case TIOCSETP:
694 		case TIOCSETN:
695 		case TIOCSETC:
696 		case TIOCSLTC:
697 		case TIOCLBIS:
698 		case TIOCLBIC:
699 		case TIOCLSET:
700 #endif
701 			pti->pt_send |= TIOCPKT_IOCTL;
702 		default:
703 			break;
704 		}
705 	}
706 	stop = (tp->t_iflag & IXON) && CCEQ(cc[VSTOP], CTRL('s'))
707 		&& CCEQ(cc[VSTART], CTRL('q'));
708 	if (pti->pt_flags & PF_NOSTOP) {
709 		if (stop) {
710 			pti->pt_send &= ~TIOCPKT_NOSTOP;
711 			pti->pt_send |= TIOCPKT_DOSTOP;
712 			pti->pt_flags &= ~PF_NOSTOP;
713 			ptcwakeup(tp, FREAD);
714 		}
715 	} else {
716 		if (!stop) {
717 			pti->pt_send &= ~TIOCPKT_DOSTOP;
718 			pti->pt_send |= TIOCPKT_NOSTOP;
719 			pti->pt_flags |= PF_NOSTOP;
720 			ptcwakeup(tp, FREAD);
721 		}
722 	}
723 	return (error);
724 }
725 #endif
726