xref: /dflybsd-src/sys/kern/tty_pty.c (revision 330d3c4b487f3fc5d0eb023645b0b2a569f7048e)
1 /*
2  * (MPSAFE)
3  *
4  * Copyright (c) 1982, 1986, 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  *	@(#)tty_pty.c	8.4 (Berkeley) 2/20/95
36  * $FreeBSD: src/sys/kern/tty_pty.c,v 1.74.2.4 2002/02/20 19:58:13 dillon Exp $
37  * $DragonFly: src/sys/kern/tty_pty.c,v 1.21 2008/08/13 10:29:38 swildner Exp $
38  */
39 
40 /*
41  * MPSAFE NOTE:
42  * Most functions here could use a separate lock to deal with concurrent
43  * access to the 'pt's.
44  *
45  * Right now the tty_token must be held for all this.
46  */
47 
48 /*
49  * Pseudo-teletype Driver
50  * (Actually two drivers, requiring two dev_ops structures)
51  */
52 #include "use_pty.h"		/* XXX */
53 #include "opt_compat.h"
54 
55 #include <sys/param.h>
56 #include <sys/systm.h>
57 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
58 #include <sys/ioctl_compat.h>
59 #endif
60 #include <sys/proc.h>
61 #include <sys/priv.h>
62 #include <sys/tty.h>
63 #include <sys/conf.h>
64 #include <sys/fcntl.h>
65 #include <sys/kernel.h>
66 #include <sys/vnode.h>
67 #include <sys/signalvar.h>
68 #include <sys/malloc.h>
69 #include <sys/device.h>
70 #include <sys/thread2.h>
71 #include <sys/devfs.h>
72 #include <sys/stat.h>
73 #include <sys/sysctl.h>
74 
75 #define	UNIX98_PTYS	1
76 
77 MALLOC_DEFINE(M_PTY, "ptys", "pty data structures");
78 
79 static void ptsstart (struct tty *tp);
80 static void ptsstop (struct tty *tp, int rw);
81 static void ptsunhold (struct tty *tp);
82 static void ptcwakeup (struct tty *tp, int flag);
83 static void ptyinit (int n);
84 static int  filt_ptcread (struct knote *kn, long hint);
85 static void filt_ptcrdetach (struct knote *kn);
86 static int  filt_ptcwrite (struct knote *kn, long hint);
87 static void filt_ptcwdetach (struct knote *kn);
88 
89 static	d_open_t	ptsopen;
90 static	d_close_t	ptsclose;
91 static	d_read_t	ptsread;
92 static	d_write_t	ptswrite;
93 static	d_ioctl_t	ptyioctl;
94 static	d_open_t	ptcopen;
95 static	d_close_t	ptcclose;
96 static	d_read_t	ptcread;
97 static	d_write_t	ptcwrite;
98 static	d_kqfilter_t	ptckqfilter;
99 
100 #ifdef UNIX98_PTYS
101 DEVFS_DECLARE_CLONE_BITMAP(pty);
102 
103 static	d_clone_t 	ptyclone;
104 
105 static int	pty_debug_level = 0;
106 
107 static struct dev_ops pts98_ops = {
108 	{ "pts98", 0, D_TTY },
109 	.d_open =	ptsopen,
110 	.d_close =	ptsclose,
111 	.d_read =	ptsread,
112 	.d_write =	ptswrite,
113 	.d_ioctl =	ptyioctl,
114 	.d_kqfilter =	ttykqfilter,
115 	.d_revoke =	ttyrevoke
116 };
117 
118 static struct dev_ops ptc98_ops = {
119 	{ "ptc98", 0, D_TTY | D_MASTER },
120 	.d_open =	ptcopen,
121 	.d_close =	ptcclose,
122 	.d_read =	ptcread,
123 	.d_write =	ptcwrite,
124 	.d_ioctl =	ptyioctl,
125 	.d_kqfilter =	ptckqfilter,
126 	.d_revoke =	ttyrevoke
127 };
128 #endif
129 
130 #define	CDEV_MAJOR_S	5
131 static struct dev_ops pts_ops = {
132 	{ "pts", CDEV_MAJOR_S, D_TTY },
133 	.d_open =	ptsopen,
134 	.d_close =	ptsclose,
135 	.d_read =	ptsread,
136 	.d_write =	ptswrite,
137 	.d_ioctl =	ptyioctl,
138 	.d_kqfilter =	ttykqfilter,
139 	.d_revoke =	ttyrevoke
140 };
141 
142 #define	CDEV_MAJOR_C	6
143 static struct dev_ops ptc_ops = {
144 	{ "ptc", CDEV_MAJOR_C, D_TTY | D_MASTER },
145 	.d_open =	ptcopen,
146 	.d_close =	ptcclose,
147 	.d_read =	ptcread,
148 	.d_write =	ptcwrite,
149 	.d_ioctl =	ptyioctl,
150 	.d_kqfilter =	ptckqfilter,
151 	.d_revoke =	ttyrevoke
152 };
153 
154 #define BUFSIZ 100		/* Chunk size iomoved to/from user */
155 
156 struct	pt_ioctl {
157 	int	pt_flags;
158 	int	pt_refs;	/* Structural references interlock S/MOPEN */
159 	int	pt_uminor;
160 	struct	kqinfo pt_kqr, pt_kqw;
161 	u_char	pt_send;
162 	u_char	pt_ucntl;
163 	struct tty pt_tty;
164 	cdev_t	devs, devc;
165 	struct	prison *pt_prison;
166 };
167 
168 /*
169  * pt_flags ptc state
170  */
171 #define	PF_PKT		0x0008		/* packet mode */
172 #define	PF_STOPPED	0x0010		/* user told stopped */
173 #define	PF_REMOTE	0x0020		/* remote and flow controlled input */
174 #define	PF_NOSTOP	0x0040
175 #define PF_UCNTL	0x0080		/* user control mode */
176 
177 #define PF_PTCSTATEMASK	0x00FF
178 
179 /*
180  * pt_flags open state.  Note that PF_SCLOSED is used to activate
181  * read EOF on the ptc so it is only set after the slave has been
182  * opened and then closed, and cleared again if the slave is opened
183  * again.
184  */
185 #define	PF_UNIX98	0x0100
186 #define	PF_SOPEN	0x0200
187 #define	PF_MOPEN	0x0400
188 #define PF_SCLOSED	0x0800
189 #define PF_TERMINATED	0x8000
190 
191 /*
192  * This function creates and initializes a pts/ptc pair
193  *
194  * pts == /dev/tty[pqrsPQRS][0123456789abcdefghijklmnopqrstuv]
195  * ptc == /dev/pty[pqrsPQRS][0123456789abcdefghijklmnopqrstuv]
196  *
197  * XXX: define and add mapping of upper minor bits to allow more
198  *      than 256 ptys.
199  */
200 static void
201 ptyinit(int n)
202 {
203 	cdev_t devs, devc;
204 	char *names = "pqrsPQRS";
205 	struct pt_ioctl *pt;
206 
207 	/* For now we only map the lower 8 bits of the minor */
208 	if (n & ~0xff)
209 		return;
210 
211 	pt = kmalloc(sizeof(*pt), M_PTY, M_WAITOK | M_ZERO);
212 	pt->devs = devs = make_dev(&pts_ops, n,
213 	    0, 0, 0666, "tty%c%r", names[n / 32], n % 32);
214 	pt->devc = devc = make_dev(&ptc_ops, n,
215 	    0, 0, 0666, "pty%c%r", names[n / 32], n % 32);
216 
217 	pt->pt_tty.t_dev = devs;
218 	pt->pt_uminor = n;
219 	devs->si_drv1 = devc->si_drv1 = pt;
220 	devs->si_tty = devc->si_tty = &pt->pt_tty;
221 	devs->si_flags |= SI_OVERRIDE;	/* uid, gid, perms from dev */
222 	devc->si_flags |= SI_OVERRIDE;	/* uid, gid, perms from dev */
223 	ttyregister(&pt->pt_tty);
224 }
225 
226 #ifdef UNIX98_PTYS
227 static int
228 ptyclone(struct dev_clone_args *ap)
229 {
230 	int unit;
231 	struct pt_ioctl *pt;
232 
233 	/*
234 	 * Limit the number of unix98 pty (slave) devices to 1000, as
235 	 * the utmp(5) format only allows for 8 bytes for the tty,
236 	 * "pts/XXX".
237 	 * If this limit is reached, we don't clone and return error
238 	 * to devfs.
239 	 */
240 	unit = devfs_clone_bitmap_get(&DEVFS_CLONE_BITMAP(pty), 1000);
241 
242 	if (unit < 0) {
243 		ap->a_dev = NULL;
244 		return 1;
245 	}
246 
247 	pt = kmalloc(sizeof(*pt), M_PTY, M_WAITOK | M_ZERO);
248 
249 	pt->devc = make_only_dev(&ptc98_ops, unit,
250 				 ap->a_cred->cr_ruid,
251 				 0, 0600, "ptm/%d", unit);
252 	pt->devs = make_dev(&pts98_ops, unit,
253 			    ap->a_cred->cr_ruid,
254 			    GID_TTY, 0620, "pts/%d", unit);
255 	ap->a_dev = pt->devc;
256 
257 	pt->devs->si_flags |= SI_OVERRIDE;	/* uid, gid, perms from dev */
258 	pt->devc->si_flags |= SI_OVERRIDE;	/* uid, gid, perms from dev */
259 
260 	pt->pt_tty.t_dev = pt->devs;
261 	pt->pt_flags |= PF_UNIX98;
262 	pt->pt_uminor = unit;
263 	pt->devs->si_drv1 = pt->devc->si_drv1 = pt;
264 	pt->devs->si_tty = pt->devc->si_tty = &pt->pt_tty;
265 
266 	ttyregister(&pt->pt_tty);
267 
268 	return 0;
269 }
270 #endif
271 
272 /*
273  * pti_hold() prevents the pti from being destroyed due to a termination
274  * while a pt*open() is blocked.
275  *
276  * This function returns non-zero if we cannot hold due to a termination
277  * interlock.
278  *
279  * NOTE: Must be called with tty_token held
280  */
281 static int
282 pti_hold(struct pt_ioctl *pti)
283 {
284 	if (pti->pt_flags & PF_TERMINATED)
285 		return(ENXIO);
286 	++pti->pt_refs;
287 	return(0);
288 }
289 
290 /*
291  * pti_done() releases the reference and checks to see if both sides have
292  * been closed on a unix98 pty, allowing us to destroy the device and
293  * release resources.
294  *
295  * We do not release resources on non-unix98 ptys.  Those are left
296  * statically allocated.
297  */
298 static void
299 pti_done(struct pt_ioctl *pti)
300 {
301 	lwkt_gettoken(&tty_token);
302 	if (--pti->pt_refs == 0) {
303 #ifdef UNIX98_PTYS
304 		cdev_t dev;
305 		int uminor_no;
306 
307 		/*
308 		 * Only unix09 ptys are freed up
309 		 */
310 		if ((pti->pt_flags & PF_UNIX98) == 0) {
311 			lwkt_reltoken(&tty_token);
312 			return;
313 		}
314 
315 		/*
316 		 * Interlock open attempts against termination by setting
317 		 * PF_TERMINATED.  This allows us to block while cleaning
318 		 * out the device infrastructure.
319 		 *
320 		 * Do not terminate the tty if it still has a session
321 		 * association (t_refs).
322 		 */
323 		if ((pti->pt_flags & (PF_SOPEN|PF_MOPEN)) == 0 &&
324 		    pti->pt_tty.t_refs == 0) {
325 			pti->pt_flags |= PF_TERMINATED;
326 			uminor_no = pti->pt_uminor;
327 
328 			if ((dev = pti->devs) != NULL) {
329 				dev->si_drv1 = NULL;
330 				pti->devs = NULL;
331 				destroy_dev(dev);
332 			}
333 			if ((dev = pti->devc) != NULL) {
334 				dev->si_drv1 = NULL;
335 				pti->devc = NULL;
336 				destroy_dev(dev);
337 			}
338 			ttyunregister(&pti->pt_tty);
339 			devfs_clone_bitmap_put(&DEVFS_CLONE_BITMAP(pty),
340 					       uminor_no);
341 			kfree(pti, M_PTY);
342 		}
343 #endif
344 	}
345 	lwkt_reltoken(&tty_token);
346 }
347 
348 /*ARGSUSED*/
349 static	int
350 ptsopen(struct dev_open_args *ap)
351 {
352 	cdev_t dev = ap->a_head.a_dev;
353 	struct tty *tp;
354 	int error;
355 	struct pt_ioctl *pti;
356 
357 	/*
358 	 * The pti will already be assigned by the clone code or
359 	 * pre-created if a non-unix 98 pty.  If si_drv1 is NULL
360 	 * we are somehow racing a unix98 termination.
361 	 */
362 	if (dev->si_drv1 == NULL)
363 		return(ENXIO);
364 	pti = dev->si_drv1;
365 
366 	lwkt_gettoken(&tty_token);
367 	if (pti_hold(pti)) {
368 		lwkt_reltoken(&tty_token);
369 		return(ENXIO);
370 	}
371 
372 	tp = dev->si_tty;
373 
374 	/*
375 	 * Reinit most of the tty state if it isn't open.  Handle
376 	 * exclusive access.
377 	 */
378 	if ((tp->t_state & TS_ISOPEN) == 0) {
379 		ttychars(tp);		/* Set up default chars */
380 		tp->t_iflag = TTYDEF_IFLAG;
381 		tp->t_oflag = TTYDEF_OFLAG;
382 		tp->t_lflag = TTYDEF_LFLAG;
383 		tp->t_cflag = TTYDEF_CFLAG;
384 		tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
385 	} else if ((tp->t_state & TS_XCLUDE) &&
386 		   priv_check_cred(ap->a_cred, PRIV_ROOT, 0)) {
387 		pti_done(pti);
388 		lwkt_reltoken(&tty_token);
389 		return (EBUSY);
390 	} else if (pti->pt_prison != ap->a_cred->cr_prison) {
391 		pti_done(pti);
392 		lwkt_reltoken(&tty_token);
393 		return (EBUSY);
394 	}
395 
396 	/*
397 	 * If the ptc is already present this will connect us up.  It
398 	 * is unclear if this is actually needed.
399 	 *
400 	 * If neither side is open be sure to clear any left over
401 	 * ZOMBIE state before continuing.
402 	 */
403 	if (tp->t_oproc)
404 		(void)(*linesw[tp->t_line].l_modem)(tp, 1);
405 	else if ((pti->pt_flags & PF_SOPEN) == 0)
406 		tp->t_state &= ~TS_ZOMBIE;
407 
408 	/*
409 	 * Wait for the carrier (ptc side)
410 	 */
411 	while ((tp->t_state & TS_CARR_ON) == 0) {
412 		if (ap->a_oflags & FNONBLOCK)
413 			break;
414 		error = ttysleep(tp, TSA_CARR_ON(tp), PCATCH, "ptsopn", 0);
415 		if (error) {
416 			pti_done(pti);
417 			lwkt_reltoken(&tty_token);
418 			return (error);
419 		}
420 	}
421 
422 	/*
423 	 * Mark the tty open and mark the slave side as being open.
424 	 */
425 	error = (*linesw[tp->t_line].l_open)(dev, tp);
426 
427 	if (error == 0) {
428 		pti->pt_flags |= PF_SOPEN;
429 		pti->pt_flags &= ~PF_SCLOSED;
430 		ptcwakeup(tp, FREAD|FWRITE);
431 	}
432 	pti_done(pti);
433 
434 	lwkt_reltoken(&tty_token);
435 	return (error);
436 }
437 
438 static	int
439 ptsclose(struct dev_close_args *ap)
440 {
441 	cdev_t dev = ap->a_head.a_dev;
442 	struct tty *tp;
443 	struct pt_ioctl *pti = dev->si_drv1;
444 	int err;
445 
446 	lwkt_gettoken(&tty_token);
447 	if (pti_hold(pti))
448 		panic("ptsclose on terminated pti");
449 
450 	/*
451 	 * Disconnect the slave side
452 	 */
453 	tp = dev->si_tty;
454 	err = (*linesw[tp->t_line].l_close)(tp, ap->a_fflag);
455 	ptsstop(tp, FREAD|FWRITE);
456 	ttyclose(tp);			/* clears t_state */
457 
458 	/*
459 	 * Mark the pts side closed and signal the ptc.  Do not mark the
460 	 * tty a zombie... that is, allow the tty to be re-opened as long
461 	 * as the ptc is still open.  The ptc will read() EOFs until the
462 	 * pts side is reopened or the ptc is closed.
463 	 *
464 	 * xterm() depends on this behavior as it will revoke() the pts
465 	 * and then reopen it after the (unnecessary old code) chmod.
466 	 */
467 	pti->pt_flags &= ~PF_SOPEN;
468 	pti->pt_flags |= PF_SCLOSED;
469 	if (tp->t_oproc)
470 		ptcwakeup(tp, FREAD);
471 	pti_done(pti);
472 	lwkt_reltoken(&tty_token);
473 	return (err);
474 }
475 
476 static	int
477 ptsread(struct dev_read_args *ap)
478 {
479 	cdev_t dev = ap->a_head.a_dev;
480 	struct proc *p = curproc;
481 	struct tty *tp = dev->si_tty;
482 	struct pt_ioctl *pti = dev->si_drv1;
483 	struct lwp *lp;
484 
485 	int error = 0;
486 
487 	lp = curthread->td_lwp;
488 
489 	lwkt_gettoken(&tty_token);
490 again:
491 	if (pti->pt_flags & PF_REMOTE) {
492 		while (isbackground(p, tp)) {
493 			if (SIGISMEMBER(p->p_sigignore, SIGTTIN) ||
494 			    SIGISMEMBER(lp->lwp_sigmask, SIGTTIN) ||
495 			    p->p_pgrp->pg_jobc == 0 || p->p_flag & P_PPWAIT) {
496 				lwkt_reltoken(&tty_token);
497 				return (EIO);
498 			}
499 			pgsignal(p->p_pgrp, SIGTTIN, 1);
500 			error = ttysleep(tp, &lbolt, PCATCH, "ptsbg", 0);
501 			if (error) {
502 				lwkt_reltoken(&tty_token);
503 				return (error);
504 			}
505 		}
506 		if (tp->t_canq.c_cc == 0) {
507 			if (ap->a_ioflag & IO_NDELAY) {
508 				lwkt_reltoken(&tty_token);
509 				return (EWOULDBLOCK);
510 			}
511 			error = ttysleep(tp, TSA_PTS_READ(tp), PCATCH,
512 					 "ptsin", 0);
513 			if (error) {
514 				lwkt_reltoken(&tty_token);
515 				return (error);
516 			}
517 			goto again;
518 		}
519 		while (tp->t_canq.c_cc > 1 && ap->a_uio->uio_resid > 0)
520 			if (ureadc(clist_getc(&tp->t_canq), ap->a_uio) < 0) {
521 				error = EFAULT;
522 				break;
523 			}
524 		if (tp->t_canq.c_cc == 1)
525 			clist_getc(&tp->t_canq);
526 		if (tp->t_canq.c_cc) {
527 			lwkt_reltoken(&tty_token);
528 			return (error);
529 		}
530 	} else
531 		if (tp->t_oproc)
532 			error = (*linesw[tp->t_line].l_read)(tp, ap->a_uio, ap->a_ioflag);
533 	ptcwakeup(tp, FWRITE);
534 	lwkt_reltoken(&tty_token);
535 	return (error);
536 }
537 
538 /*
539  * Write to pseudo-tty.
540  * Wakeups of controlling tty will happen
541  * indirectly, when tty driver calls ptsstart.
542  */
543 static	int
544 ptswrite(struct dev_write_args *ap)
545 {
546 	cdev_t dev = ap->a_head.a_dev;
547 	struct tty *tp;
548 	int ret;
549 
550 	lwkt_gettoken(&tty_token);
551 	tp = dev->si_tty;
552 	if (tp->t_oproc == 0) {
553 		lwkt_reltoken(&tty_token);
554 		return (EIO);
555 	}
556 	ret = ((*linesw[tp->t_line].l_write)(tp, ap->a_uio, ap->a_ioflag));
557 	lwkt_reltoken(&tty_token);
558 	return ret;
559 }
560 
561 /*
562  * Start output on pseudo-tty.
563  * Wake up process selecting or sleeping for input from controlling tty.
564  */
565 static void
566 ptsstart(struct tty *tp)
567 {
568 	lwkt_gettoken(&tty_token);
569 	struct pt_ioctl *pti = tp->t_dev->si_drv1;
570 
571 	if (tp->t_state & TS_TTSTOP) {
572 		lwkt_reltoken(&tty_token);
573 		return;
574 	}
575 	if (pti) {
576 		if (pti->pt_flags & PF_STOPPED) {
577 			pti->pt_flags &= ~PF_STOPPED;
578 			pti->pt_send = TIOCPKT_START;
579 		}
580 	}
581 	ptcwakeup(tp, FREAD);
582 	lwkt_reltoken(&tty_token);
583 }
584 
585 /*
586  * NOTE: Must be called with tty_token held
587  */
588 static void
589 ptcwakeup(struct tty *tp, int flag)
590 {
591 	ASSERT_LWKT_TOKEN_HELD(&tty_token);
592 
593 	if (flag & FREAD) {
594 		wakeup(TSA_PTC_READ(tp));
595 		KNOTE(&tp->t_rkq.ki_note, 0);
596 	}
597 	if (flag & FWRITE) {
598 		wakeup(TSA_PTC_WRITE(tp));
599 		KNOTE(&tp->t_wkq.ki_note, 0);
600 	}
601 }
602 
603 static	int
604 ptcopen(struct dev_open_args *ap)
605 {
606 	cdev_t dev = ap->a_head.a_dev;
607 	struct tty *tp;
608 	struct pt_ioctl *pti;
609 
610 	/*
611 	 * The pti will already be assigned by the clone code or
612 	 * pre-created if a non-unix 98 pty.  If si_drv1 is NULL
613 	 * we are somehow racing a unix98 termination.
614 	 */
615 	if (dev->si_drv1 == NULL)
616 		return(ENXIO);
617 
618 	lwkt_gettoken(&tty_token);
619 	pti = dev->si_drv1;
620 	if (pti_hold(pti)) {
621 		lwkt_reltoken(&tty_token);
622 		return(ENXIO);
623 	}
624 	if (pti->pt_prison && pti->pt_prison != ap->a_cred->cr_prison) {
625 		pti_done(pti);
626 		lwkt_reltoken(&tty_token);
627 		return(EBUSY);
628 	}
629 	tp = dev->si_tty;
630 	if (tp->t_oproc) {
631 		pti_done(pti);
632 		lwkt_reltoken(&tty_token);
633 		return (EIO);
634 	}
635 
636 	/*
637 	 * If the slave side is not yet open clear any left over zombie
638 	 * state before doing our modem control.
639 	 */
640 	if ((pti->pt_flags & PF_SOPEN) == 0)
641 		tp->t_state &= ~TS_ZOMBIE;
642 
643 	tp->t_oproc = ptsstart;
644 	tp->t_stop = ptsstop;
645 	tp->t_unhold = ptsunhold;
646 
647 	/*
648 	 * Carrier on!
649 	 */
650 	(void)(*linesw[tp->t_line].l_modem)(tp, 1);
651 
652 	tp->t_lflag &= ~EXTPROC;
653 	pti->pt_prison = ap->a_cred->cr_prison;
654 	pti->pt_flags &= ~PF_PTCSTATEMASK;
655 	pti->pt_send = 0;
656 	pti->pt_ucntl = 0;
657 
658 	pti->devs->si_uid = ap->a_cred->cr_uid;
659 	pti->devs->si_gid = 0;
660 	pti->devs->si_perms = 0600;
661 	pti->devc->si_uid = ap->a_cred->cr_uid;
662 	pti->devc->si_gid = 0;
663 	pti->devc->si_perms = 0600;
664 
665 	/*
666 	 * Mark master side open.  This does not cause any events
667 	 * on the slave side.
668 	 */
669 	pti->pt_flags |= PF_MOPEN;
670 	pti_done(pti);
671 
672 	lwkt_reltoken(&tty_token);
673 	return (0);
674 }
675 
676 static	int
677 ptcclose(struct dev_close_args *ap)
678 {
679 	cdev_t dev = ap->a_head.a_dev;
680 	struct tty *tp;
681 	struct pt_ioctl *pti = dev->si_drv1;
682 
683 	lwkt_gettoken(&tty_token);
684 	if (pti_hold(pti))
685 		panic("ptcclose on terminated pti");
686 
687 	tp = dev->si_tty;
688 	(void)(*linesw[tp->t_line].l_modem)(tp, 0);
689 
690 	/*
691 	 * Mark the master side closed.  If the slave is still open
692 	 * mark the tty ZOMBIE, preventing any new action until both
693 	 * sides have closed.
694 	 *
695 	 * NOTE: The ttyflush() will wake up the slave once we've
696 	 *	 set appropriate flags.  The ZOMBIE flag will be
697 	 *	 cleared when the slave side is closed.
698 	 */
699 	pti->pt_flags &= ~PF_MOPEN;
700 	if (pti->pt_flags & PF_SOPEN)
701 		tp->t_state |= TS_ZOMBIE;
702 
703 	/*
704 	 * Turn off the carrier and disconnect.  This will notify the slave
705 	 * side.
706 	 */
707 	if (tp->t_state & TS_ISOPEN) {
708 		tp->t_state &= ~(TS_CARR_ON | TS_CONNECTED);
709 		ttyflush(tp, FREAD | FWRITE);
710 	}
711 	tp->t_oproc = NULL;		/* mark closed */
712 
713 	pti->pt_prison = NULL;
714 	pti->devs->si_uid = 0;
715 	pti->devs->si_gid = 0;
716 	pti->devs->si_perms = 0666;
717 	pti->devc->si_uid = 0;
718 	pti->devc->si_gid = 0;
719 	pti->devc->si_perms = 0666;
720 
721 	pti_done(pti);
722 
723 	lwkt_reltoken(&tty_token);
724 	return (0);
725 }
726 
727 static	int
728 ptcread(struct dev_read_args *ap)
729 {
730 	cdev_t dev = ap->a_head.a_dev;
731 	struct tty *tp = dev->si_tty;
732 	struct pt_ioctl *pti = dev->si_drv1;
733 	char buf[BUFSIZ];
734 	int error = 0, cc;
735 
736 	lwkt_gettoken(&tty_token);
737 	/*
738 	 * We want to block until the slave
739 	 * is open, and there's something to read;
740 	 * but if we lost the slave or we're NBIO,
741 	 * then return the appropriate error instead.
742 	 */
743 	for (;;) {
744 		if (tp->t_state&TS_ISOPEN) {
745 			if ((pti->pt_flags & PF_PKT) && pti->pt_send) {
746 				error = ureadc((int)pti->pt_send, ap->a_uio);
747 				if (error) {
748 					lwkt_reltoken(&tty_token);
749 					return (error);
750 				}
751 				if (pti->pt_send & TIOCPKT_IOCTL) {
752 					cc = (int)szmin(ap->a_uio->uio_resid,
753 							sizeof(tp->t_termios));
754 					uiomove((caddr_t)&tp->t_termios, cc,
755 						ap->a_uio);
756 				}
757 				pti->pt_send = 0;
758 				lwkt_reltoken(&tty_token);
759 				return (0);
760 			}
761 			if ((pti->pt_flags & PF_UCNTL) && pti->pt_ucntl) {
762 				error = ureadc((int)pti->pt_ucntl, ap->a_uio);
763 				if (error) {
764 					lwkt_reltoken(&tty_token);
765 					return (error);
766 				}
767 				pti->pt_ucntl = 0;
768 				lwkt_reltoken(&tty_token);
769 				return (0);
770 			}
771 			if (tp->t_outq.c_cc && (tp->t_state&TS_TTSTOP) == 0)
772 				break;
773 		}
774 		if ((tp->t_state & TS_CONNECTED) == 0) {
775 			lwkt_reltoken(&tty_token);
776 			return (0);	/* EOF */
777 		}
778 		if (ap->a_ioflag & IO_NDELAY) {
779 			lwkt_reltoken(&tty_token);
780 			return (EWOULDBLOCK);
781 		}
782 		error = tsleep(TSA_PTC_READ(tp), PCATCH, "ptcin", 0);
783 		if (error) {
784 			lwkt_reltoken(&tty_token);
785 			return (error);
786 		}
787 	}
788 	if (pti->pt_flags & (PF_PKT|PF_UCNTL))
789 		error = ureadc(0, ap->a_uio);
790 	while (ap->a_uio->uio_resid > 0 && error == 0) {
791 		cc = q_to_b(&tp->t_outq, buf,
792 			    (int)szmin(ap->a_uio->uio_resid, BUFSIZ));
793 		if (cc <= 0)
794 			break;
795 		error = uiomove(buf, (size_t)cc, ap->a_uio);
796 	}
797 	ttwwakeup(tp);
798 	lwkt_reltoken(&tty_token);
799 	return (error);
800 }
801 
802 static	void
803 ptsstop(struct tty *tp, int flush)
804 {
805 	struct pt_ioctl *pti = tp->t_dev->si_drv1;
806 	int flag;
807 
808 	lwkt_gettoken(&tty_token);
809 	/* note: FLUSHREAD and FLUSHWRITE already ok */
810 	if (pti) {
811 		if (flush == 0) {
812 			flush = TIOCPKT_STOP;
813 			pti->pt_flags |= PF_STOPPED;
814 		} else {
815 			pti->pt_flags &= ~PF_STOPPED;
816 		}
817 		pti->pt_send |= flush;
818 		/* change of perspective */
819 	}
820 	flag = 0;
821 	if (flush & FREAD)
822 		flag |= FWRITE;
823 	if (flush & FWRITE)
824 		flag |= FREAD;
825 	ptcwakeup(tp, flag);
826 
827 	lwkt_reltoken(&tty_token);
828 }
829 
830 /*
831  * ttyunhold() calls us instead of just decrementing tp->t_refs.  This
832  * is needed because a session can hold onto a pts (half closed state)
833  * even if there are no live file descriptors.  Without the callback
834  * we can't clean up.
835  */
836 static	void
837 ptsunhold(struct tty *tp)
838 {
839 	struct pt_ioctl *pti = tp->t_dev->si_drv1;
840 
841 	lwkt_gettoken(&tty_token);
842 	pti_hold(pti);
843 	--tp->t_refs;
844 	pti_done(pti);
845 	lwkt_reltoken(&tty_token);
846 }
847 
848 /*
849  * kqueue ops for pseudo-terminals.
850  */
851 static struct filterops ptcread_filtops =
852 	{ FILTEROP_ISFD, NULL, filt_ptcrdetach, filt_ptcread };
853 static struct filterops ptcwrite_filtops =
854 	{ FILTEROP_ISFD, NULL, filt_ptcwdetach, filt_ptcwrite };
855 
856 static	int
857 ptckqfilter(struct dev_kqfilter_args *ap)
858 {
859 	cdev_t dev = ap->a_head.a_dev;
860 	struct knote *kn = ap->a_kn;
861 	struct tty *tp = dev->si_tty;
862 	struct klist *klist;
863 
864 	lwkt_gettoken(&tty_token);
865 	ap->a_result = 0;
866 	switch (kn->kn_filter) {
867 	case EVFILT_READ:
868 		klist = &tp->t_rkq.ki_note;
869 		kn->kn_fop = &ptcread_filtops;
870 		break;
871 	case EVFILT_WRITE:
872 		klist = &tp->t_wkq.ki_note;
873 		kn->kn_fop = &ptcwrite_filtops;
874 		break;
875 	default:
876 		ap->a_result = EOPNOTSUPP;
877 		lwkt_reltoken(&tty_token);
878 		return (0);
879 	}
880 
881 	kn->kn_hook = (caddr_t)dev;
882 	knote_insert(klist, kn);
883 	lwkt_reltoken(&tty_token);
884 	return (0);
885 }
886 
887 static int
888 filt_ptcread (struct knote *kn, long hint)
889 {
890 	struct tty *tp = ((cdev_t)kn->kn_hook)->si_tty;
891 	struct pt_ioctl *pti = ((cdev_t)kn->kn_hook)->si_drv1;
892 
893 	lwkt_gettoken(&tty_token);
894 	if ((tp->t_state & TS_ZOMBIE) || (pti->pt_flags & PF_SCLOSED)) {
895 		kn->kn_flags |= EV_EOF;
896 		lwkt_reltoken(&tty_token);
897 		return (1);
898 	}
899 
900 	if ((tp->t_state & TS_ISOPEN) &&
901 	    ((tp->t_outq.c_cc && (tp->t_state & TS_TTSTOP) == 0) ||
902 	     ((pti->pt_flags & PF_PKT) && pti->pt_send) ||
903 	     ((pti->pt_flags & PF_UCNTL) && pti->pt_ucntl))) {
904 		kn->kn_data = tp->t_outq.c_cc;
905 		lwkt_reltoken(&tty_token);
906 		return(1);
907 	} else {
908 		lwkt_reltoken(&tty_token);
909 		return(0);
910 	}
911 }
912 
913 static int
914 filt_ptcwrite (struct knote *kn, long hint)
915 {
916 	struct tty *tp = ((cdev_t)kn->kn_hook)->si_tty;
917 	struct pt_ioctl *pti = ((cdev_t)kn->kn_hook)->si_drv1;
918 
919 	lwkt_gettoken(&tty_token);
920 	if (tp->t_state & TS_ZOMBIE) {
921 		kn->kn_flags |= EV_EOF;
922 		lwkt_reltoken(&tty_token);
923 		return (1);
924 	}
925 
926 	if (tp->t_state & TS_ISOPEN &&
927 	    ((pti->pt_flags & PF_REMOTE) ?
928 	     (tp->t_canq.c_cc == 0) :
929 	     ((tp->t_rawq.c_cc + tp->t_canq.c_cc < TTYHOG - 2) ||
930 	      (tp->t_canq.c_cc == 0 && (tp->t_lflag & ICANON))))) {
931 		kn->kn_data = tp->t_canq.c_cc + tp->t_rawq.c_cc;
932 		lwkt_reltoken(&tty_token);
933 		return(1);
934 	} else {
935 		lwkt_reltoken(&tty_token);
936 		return(0);
937 	}
938 	/* NOTREACHED */
939 }
940 
941 static void
942 filt_ptcrdetach (struct knote *kn)
943 {
944 	struct tty *tp = ((cdev_t)kn->kn_hook)->si_tty;
945 
946 	knote_remove(&tp->t_rkq.ki_note, kn);
947 }
948 
949 static void
950 filt_ptcwdetach (struct knote *kn)
951 {
952 	struct tty *tp = ((cdev_t)kn->kn_hook)->si_tty;
953 
954 	knote_remove(&tp->t_wkq.ki_note, kn);
955 }
956 
957 /*
958  * I/O ops
959  */
960 static	int
961 ptcwrite(struct dev_write_args *ap)
962 {
963 	cdev_t dev = ap->a_head.a_dev;
964 	struct tty *tp = dev->si_tty;
965 	u_char *cp = 0;
966 	int cc = 0;
967 	u_char locbuf[BUFSIZ];
968 	int cnt = 0;
969 	struct pt_ioctl *pti = dev->si_drv1;
970 	int error = 0;
971 
972 	lwkt_gettoken(&tty_token);
973 again:
974 	if ((tp->t_state&TS_ISOPEN) == 0)
975 		goto block;
976 	if (pti->pt_flags & PF_REMOTE) {
977 		if (tp->t_canq.c_cc)
978 			goto block;
979 		while ((ap->a_uio->uio_resid > 0 || cc > 0) &&
980 		       tp->t_canq.c_cc < TTYHOG - 1) {
981 			if (cc == 0) {
982 				cc = (int)szmin(ap->a_uio->uio_resid, BUFSIZ);
983 				cc = imin(cc, TTYHOG - 1 - tp->t_canq.c_cc);
984 				cp = locbuf;
985 				error = uiomove(cp, (size_t)cc, ap->a_uio);
986 				if (error) {
987 					lwkt_reltoken(&tty_token);
988 					return (error);
989 				}
990 				/* check again for safety */
991 				if ((tp->t_state & TS_ISOPEN) == 0) {
992 					/* adjust as usual */
993 					ap->a_uio->uio_resid += cc;
994 					lwkt_reltoken(&tty_token);
995 					return (EIO);
996 				}
997 			}
998 			if (cc > 0) {
999 				cc = b_to_q((char *)cp, cc, &tp->t_canq);
1000 				/*
1001 				 * XXX we don't guarantee that the canq size
1002 				 * is >= TTYHOG, so the above b_to_q() may
1003 				 * leave some bytes uncopied.  However, space
1004 				 * is guaranteed for the null terminator if
1005 				 * we don't fail here since (TTYHOG - 1) is
1006 				 * not a multiple of CBSIZE.
1007 				 */
1008 				if (cc > 0)
1009 					break;
1010 			}
1011 		}
1012 		/* adjust for data copied in but not written */
1013 		ap->a_uio->uio_resid += cc;
1014 		clist_putc(0, &tp->t_canq);
1015 		ttwakeup(tp);
1016 		wakeup(TSA_PTS_READ(tp));
1017 		lwkt_reltoken(&tty_token);
1018 		return (0);
1019 	}
1020 	while (ap->a_uio->uio_resid > 0 || cc > 0) {
1021 		if (cc == 0) {
1022 			cc = (int)szmin(ap->a_uio->uio_resid, BUFSIZ);
1023 			cp = locbuf;
1024 			error = uiomove(cp, (size_t)cc, ap->a_uio);
1025 			if (error) {
1026 				lwkt_reltoken(&tty_token);
1027 				return (error);
1028 			}
1029 			/* check again for safety */
1030 			if ((tp->t_state & TS_ISOPEN) == 0) {
1031 				/* adjust for data copied in but not written */
1032 				ap->a_uio->uio_resid += cc;
1033 				lwkt_reltoken(&tty_token);
1034 				return (EIO);
1035 			}
1036 		}
1037 		while (cc > 0) {
1038 			if ((tp->t_rawq.c_cc + tp->t_canq.c_cc) >= TTYHOG - 2 &&
1039 			   (tp->t_canq.c_cc > 0 || !(tp->t_lflag&ICANON))) {
1040 				wakeup(TSA_HUP_OR_INPUT(tp));
1041 				goto block;
1042 			}
1043 			(*linesw[tp->t_line].l_rint)(*cp++, tp);
1044 			cnt++;
1045 			cc--;
1046 		}
1047 		cc = 0;
1048 	}
1049 	lwkt_reltoken(&tty_token);
1050 	return (0);
1051 block:
1052 	/*
1053 	 * Come here to wait for slave to open, for space
1054 	 * in outq, or space in rawq, or an empty canq.
1055 	 */
1056 	if ((tp->t_state & TS_CONNECTED) == 0) {
1057 		/* adjust for data copied in but not written */
1058 		ap->a_uio->uio_resid += cc;
1059 		lwkt_reltoken(&tty_token);
1060 		return (EIO);
1061 	}
1062 	if (ap->a_ioflag & IO_NDELAY) {
1063 		/* adjust for data copied in but not written */
1064 		ap->a_uio->uio_resid += cc;
1065 		if (cnt == 0) {
1066 			lwkt_reltoken(&tty_token);
1067 			return (EWOULDBLOCK);
1068 		}
1069 		lwkt_reltoken(&tty_token);
1070 		return (0);
1071 	}
1072 	error = tsleep(TSA_PTC_WRITE(tp), PCATCH, "ptcout", 0);
1073 	if (error) {
1074 		/* adjust for data copied in but not written */
1075 		ap->a_uio->uio_resid += cc;
1076 		lwkt_reltoken(&tty_token);
1077 		return (error);
1078 	}
1079 	goto again;
1080 }
1081 
1082 /*ARGSUSED*/
1083 static	int
1084 ptyioctl(struct dev_ioctl_args *ap)
1085 {
1086 	cdev_t dev = ap->a_head.a_dev;
1087 	struct tty *tp = dev->si_tty;
1088 	struct pt_ioctl *pti = dev->si_drv1;
1089 	u_char *cc = tp->t_cc;
1090 	int stop, error;
1091 
1092 	lwkt_gettoken(&tty_token);
1093 	if (dev_dflags(dev) & D_MASTER) {
1094 		switch (ap->a_cmd) {
1095 
1096 		case TIOCGPGRP:
1097 			/*
1098 			 * We avoid calling ttioctl on the controller since,
1099 			 * in that case, tp must be the controlling terminal.
1100 			 */
1101 			*(int *)ap->a_data = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
1102 			lwkt_reltoken(&tty_token);
1103 			return (0);
1104 
1105 		case TIOCPKT:
1106 			if (*(int *)ap->a_data) {
1107 				if (pti->pt_flags & PF_UCNTL) {
1108 					lwkt_reltoken(&tty_token);
1109 					return (EINVAL);
1110 				}
1111 				pti->pt_flags |= PF_PKT;
1112 			} else {
1113 				pti->pt_flags &= ~PF_PKT;
1114 			}
1115 			lwkt_reltoken(&tty_token);
1116 			return (0);
1117 
1118 		case TIOCUCNTL:
1119 			if (*(int *)ap->a_data) {
1120 				if (pti->pt_flags & PF_PKT) {
1121 					lwkt_reltoken(&tty_token);
1122 					return (EINVAL);
1123 				}
1124 				pti->pt_flags |= PF_UCNTL;
1125 			} else {
1126 				pti->pt_flags &= ~PF_UCNTL;
1127 			}
1128 			lwkt_reltoken(&tty_token);
1129 			return (0);
1130 
1131 		case TIOCREMOTE:
1132 			if (*(int *)ap->a_data)
1133 				pti->pt_flags |= PF_REMOTE;
1134 			else
1135 				pti->pt_flags &= ~PF_REMOTE;
1136 			ttyflush(tp, FREAD|FWRITE);
1137 			lwkt_reltoken(&tty_token);
1138 			return (0);
1139 
1140 #ifdef UNIX98_PTYS
1141 		case TIOCISPTMASTER:
1142 			if ((pti->pt_flags & PF_UNIX98) &&
1143 			    (pti->devc == dev)) {
1144 				lwkt_reltoken(&tty_token);
1145 				return (0);
1146 			} else {
1147 				lwkt_reltoken(&tty_token);
1148 				return (EINVAL);
1149 			}
1150 		}
1151 #endif
1152 
1153 		/*
1154 		 * The rest of the ioctls shouldn't be called until
1155 		 * the slave is open.
1156 		 */
1157 		if ((tp->t_state & TS_ISOPEN) == 0) {
1158 			lwkt_reltoken(&tty_token);
1159 			return (EAGAIN);
1160 		}
1161 
1162 		switch (ap->a_cmd) {
1163 #ifdef COMPAT_43
1164 		case TIOCSETP:
1165 		case TIOCSETN:
1166 #endif
1167 		case TIOCSETD:
1168 		case TIOCSETA:
1169 		case TIOCSETAW:
1170 		case TIOCSETAF:
1171 			/*
1172 			 * IF CONTROLLER STTY THEN MUST FLUSH TO PREVENT A HANG.
1173 			 * ttywflush(tp) will hang if there are characters in
1174 			 * the outq.
1175 			 */
1176 			ndflush(&tp->t_outq, tp->t_outq.c_cc);
1177 			break;
1178 
1179 		case TIOCSIG:
1180 			if (*(unsigned int *)ap->a_data >= NSIG ||
1181 			    *(unsigned int *)ap->a_data == 0) {
1182 				lwkt_reltoken(&tty_token);
1183 				return(EINVAL);
1184 			}
1185 			if ((tp->t_lflag&NOFLSH) == 0)
1186 				ttyflush(tp, FREAD|FWRITE);
1187 			pgsignal(tp->t_pgrp, *(unsigned int *)ap->a_data, 1);
1188 			if ((*(unsigned int *)ap->a_data == SIGINFO) &&
1189 			    ((tp->t_lflag&NOKERNINFO) == 0))
1190 				ttyinfo(tp);
1191 			lwkt_reltoken(&tty_token);
1192 			return(0);
1193 		}
1194 	}
1195 	if (ap->a_cmd == TIOCEXT) {
1196 		/*
1197 		 * When the EXTPROC bit is being toggled, we need
1198 		 * to send an TIOCPKT_IOCTL if the packet driver
1199 		 * is turned on.
1200 		 */
1201 		if (*(int *)ap->a_data) {
1202 			if (pti->pt_flags & PF_PKT) {
1203 				pti->pt_send |= TIOCPKT_IOCTL;
1204 				ptcwakeup(tp, FREAD);
1205 			}
1206 			tp->t_lflag |= EXTPROC;
1207 		} else {
1208 			if ((tp->t_lflag & EXTPROC) &&
1209 			    (pti->pt_flags & PF_PKT)) {
1210 				pti->pt_send |= TIOCPKT_IOCTL;
1211 				ptcwakeup(tp, FREAD);
1212 			}
1213 			tp->t_lflag &= ~EXTPROC;
1214 		}
1215 		lwkt_reltoken(&tty_token);
1216 		return(0);
1217 	}
1218 	error = (*linesw[tp->t_line].l_ioctl)(tp, ap->a_cmd, ap->a_data,
1219 					      ap->a_fflag, ap->a_cred);
1220 	if (error == ENOIOCTL)
1221 		 error = ttioctl(tp, ap->a_cmd, ap->a_data, ap->a_fflag);
1222 	if (error == ENOIOCTL) {
1223 		if (pti->pt_flags & PF_UCNTL &&
1224 		    (ap->a_cmd & ~0xff) == UIOCCMD(0)) {
1225 			if (ap->a_cmd & 0xff) {
1226 				pti->pt_ucntl = (u_char)ap->a_cmd;
1227 				ptcwakeup(tp, FREAD);
1228 			}
1229 			lwkt_reltoken(&tty_token);
1230 			return (0);
1231 		}
1232 		error = ENOTTY;
1233 	}
1234 	/*
1235 	 * If external processing and packet mode send ioctl packet.
1236 	 */
1237 	if ((tp->t_lflag&EXTPROC) && (pti->pt_flags & PF_PKT)) {
1238 		switch(ap->a_cmd) {
1239 		case TIOCSETA:
1240 		case TIOCSETAW:
1241 		case TIOCSETAF:
1242 #ifdef COMPAT_43
1243 		case TIOCSETP:
1244 		case TIOCSETN:
1245 #endif
1246 #if defined(COMPAT_43) || defined(COMPAT_SUNOS)
1247 		case TIOCSETC:
1248 		case TIOCSLTC:
1249 		case TIOCLBIS:
1250 		case TIOCLBIC:
1251 		case TIOCLSET:
1252 #endif
1253 			pti->pt_send |= TIOCPKT_IOCTL;
1254 			ptcwakeup(tp, FREAD);
1255 		default:
1256 			break;
1257 		}
1258 	}
1259 	stop = (tp->t_iflag & IXON) && CCEQ(cc[VSTOP], CTRL('s'))
1260 		&& CCEQ(cc[VSTART], CTRL('q'));
1261 	if (pti->pt_flags & PF_NOSTOP) {
1262 		if (stop) {
1263 			pti->pt_send &= ~TIOCPKT_NOSTOP;
1264 			pti->pt_send |= TIOCPKT_DOSTOP;
1265 			pti->pt_flags &= ~PF_NOSTOP;
1266 			ptcwakeup(tp, FREAD);
1267 		}
1268 	} else {
1269 		if (!stop) {
1270 			pti->pt_send &= ~TIOCPKT_DOSTOP;
1271 			pti->pt_send |= TIOCPKT_NOSTOP;
1272 			pti->pt_flags |= PF_NOSTOP;
1273 			ptcwakeup(tp, FREAD);
1274 		}
1275 	}
1276 	lwkt_reltoken(&tty_token);
1277 	return (error);
1278 }
1279 
1280 
1281 static void ptc_drvinit (void *unused);
1282 
1283 #ifdef UNIX98_PTYS
1284 SYSCTL_INT(_kern, OID_AUTO, pty_debug, CTLFLAG_RW, &pty_debug_level,
1285 		0, "Change pty debug level");
1286 #endif
1287 
1288 static void
1289 ptc_drvinit(void *unused)
1290 {
1291 	int i;
1292 
1293 #ifdef UNIX98_PTYS
1294 	/*
1295 	 * Unix98 pty stuff.
1296 	 * Create the clonable base device.
1297 	 */
1298 	make_autoclone_dev(&ptc_ops, &DEVFS_CLONE_BITMAP(pty), ptyclone,
1299 	    0, 0, 0666, "ptmx");
1300 #endif
1301 
1302 	for (i = 0; i < 256; i++) {
1303 		ptyinit(i);
1304 	}
1305 }
1306 
1307 SYSINIT(ptcdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR_C,ptc_drvinit,NULL)
1308