1 /* $NetBSD: tty_pty.c,v 1.149 2021/10/11 01:07:36 thorpej Exp $ */
2
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. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 *
31 * @(#)tty_pty.c 8.4 (Berkeley) 2/20/95
32 */
33
34 /*
35 * Pseudo-teletype Driver
36 * (Actually two drivers, requiring two entries in 'cdevsw')
37 */
38
39 #include <sys/cdefs.h>
40 __KERNEL_RCSID(0, "$NetBSD: tty_pty.c,v 1.149 2021/10/11 01:07:36 thorpej Exp $");
41
42 #include "opt_ptm.h"
43
44 #define TTY_ALLOW_PRIVATE
45
46 #include <sys/param.h>
47 #include <sys/systm.h>
48 #include <sys/ioctl.h>
49 #include <sys/ioctl_compat.h>
50 #include <sys/proc.h>
51 #include <sys/tty.h>
52 #include <sys/stat.h>
53 #include <sys/file.h>
54 #include <sys/kernel.h>
55 #include <sys/vnode.h>
56 #include <sys/namei.h>
57 #include <sys/signalvar.h>
58 #include <sys/uio.h>
59 #include <sys/filedesc.h>
60 #include <sys/conf.h>
61 #include <sys/poll.h>
62 #include <sys/pty.h>
63 #include <sys/kauth.h>
64
65 #include "ioconf.h"
66
67 #define DEFAULT_NPTYS 16 /* default number of initial ptys */
68 #define DEFAULT_MAXPTYS 992 /* default maximum number of ptys */
69
70 #define BUFSIZ 100 /* Chunk size iomoved to/from user */
71
72 struct pt_softc {
73 struct tty *pt_tty;
74 int pt_flags;
75 struct selinfo pt_selr, pt_selw;
76 u_char pt_send;
77 u_char pt_ucntl;
78 };
79
80 static struct pt_softc **pt_softc = NULL; /* pty array */
81 static int maxptys = DEFAULT_MAXPTYS; /* maximum number of ptys (sysctable) */
82 kmutex_t pt_softc_mutex;
83 int npty = 0; /* for pstat -t */
84
85 #define PF_PKT 0x08 /* packet mode */
86 #define PF_STOPPED 0x10 /* user told stopped */
87 #define PF_REMOTE 0x20 /* remote and flow controlled input */
88 #define PF_NOSTOP 0x40
89 #define PF_UCNTL 0x80 /* user control mode */
90
91 void ptcwakeup(struct tty *, int);
92 void ptsstart(struct tty *);
93 int pty_maxptys(int, int);
94
95 static struct pt_softc **ptyarralloc(int);
96
97 dev_type_open(ptcopen);
98 dev_type_close(ptcclose);
99 dev_type_read(ptcread);
100 dev_type_write(ptcwrite);
101 dev_type_poll(ptcpoll);
102 dev_type_kqfilter(ptckqfilter);
103
104 dev_type_open(ptsopen);
105 dev_type_close(ptsclose);
106 dev_type_read(ptsread);
107 dev_type_write(ptswrite);
108 dev_type_stop(ptsstop);
109 dev_type_poll(ptspoll);
110
111 dev_type_ioctl(ptyioctl);
112 dev_type_tty(ptytty);
113
114 const struct cdevsw ptc_cdevsw = {
115 .d_open = ptcopen,
116 .d_close = ptcclose,
117 .d_read = ptcread,
118 .d_write = ptcwrite,
119 .d_ioctl = ptyioctl,
120 .d_stop = nullstop,
121 .d_tty = ptytty,
122 .d_poll = ptcpoll,
123 .d_mmap = nommap,
124 .d_kqfilter = ptckqfilter,
125 .d_discard = nodiscard,
126 .d_flag = D_TTY
127 };
128
129 const struct cdevsw pts_cdevsw = {
130 .d_open = ptsopen,
131 .d_close = ptsclose,
132 .d_read = ptsread,
133 .d_write = ptswrite,
134 .d_ioctl = ptyioctl,
135 .d_stop = ptsstop,
136 .d_tty = ptytty,
137 .d_poll = ptspoll,
138 .d_mmap = nommap,
139 .d_kqfilter = ttykqfilter,
140 .d_discard = nodiscard,
141 .d_flag = D_TTY
142 };
143
144 #if defined(pmax)
145 /*
146 * Used by arch/pmax/conf/majors.pmax, which needs a second copy as it
147 * needs to map this stuff to two pairs of majors.
148 */
149
150 const struct cdevsw ptc_ultrix_cdevsw = {
151 .d_open = ptcopen,
152 .d_close = ptcclose,
153 .d_read = ptcread,
154 .d_write = ptcwrite,
155 .d_ioctl = ptyioctl,
156 .d_stop = nullstop,
157 .d_tty = ptytty,
158 .d_poll = ptcpoll,
159 .d_mmap = nommap,
160 .d_kqfilter = ptckqfilter,
161 .d_discard = nodiscard,
162 .d_flag = D_TTY
163 };
164
165 const struct cdevsw pts_ultrix_cdevsw = {
166 .d_open = ptsopen,
167 .d_close = ptsclose,
168 .d_read = ptsread,
169 .d_write = ptswrite,
170 .d_ioctl = ptyioctl,
171 .d_stop = ptsstop,
172 .d_tty = ptytty,
173 .d_poll = ptspoll,
174 .d_mmap = nommap,
175 .d_kqfilter = ttykqfilter,
176 .d_discard = nodiscard,
177 .d_flag = D_TTY
178 };
179 #endif /* defined(pmax) */
180
181 /*
182 * Check if a pty is free to use.
183 */
184 int
pty_isfree(int minor,int lock)185 pty_isfree(int minor, int lock)
186 {
187 struct pt_softc *pt = pt_softc[minor];
188 if (lock)
189 mutex_enter(&pt_softc_mutex);
190 minor = pt == NULL || pt->pt_tty == NULL ||
191 pt->pt_tty->t_oproc == NULL;
192 if (lock)
193 mutex_exit(&pt_softc_mutex);
194 return minor;
195 }
196
197 /*
198 * Allocate and zero array of nelem elements.
199 */
200 static struct pt_softc **
ptyarralloc(int nelem)201 ptyarralloc(int nelem)
202 {
203 struct pt_softc **pt;
204 nelem += 10;
205 pt = kmem_zalloc(nelem * sizeof(*pt), KM_SLEEP);
206 return pt;
207 }
208
209 static void
ptyarrfree(struct pt_softc ** pt,int nelem)210 ptyarrfree(struct pt_softc **pt, int nelem)
211 {
212
213 nelem += 10;
214 kmem_free(pt, nelem * sizeof(*pt));
215 }
216
217 /*
218 * Check if the minor is correct and ensure necessary structures
219 * are properly allocated.
220 */
221 int
pty_check(int ptn)222 pty_check(int ptn)
223 {
224 struct pt_softc *pti;
225
226 if (ptn >= npty) {
227 struct pt_softc **newpt, **oldpt;
228 int newnpty;
229 int oldnpty;
230
231 /* check if the requested pty can be granted */
232 if (ptn >= maxptys) {
233 limit_reached:
234 tablefull("pty", "increase kern.maxptys");
235 return ENXIO;
236 }
237
238 /* Allocate a larger pty array */
239 for (newnpty = npty; newnpty <= ptn;)
240 newnpty *= 2;
241 if (newnpty > maxptys)
242 newnpty = maxptys;
243 newpt = ptyarralloc(newnpty);
244
245 /*
246 * Now grab the pty array mutex - we need to ensure
247 * that the pty array is consistent while copying its
248 * content to newly allocated, larger space; we also
249 * need to be safe against pty_maxptys().
250 */
251 mutex_enter(&pt_softc_mutex);
252
253 if (newnpty >= maxptys) {
254 /* limit cut away beneath us... */
255 if (ptn >= maxptys) {
256 mutex_exit(&pt_softc_mutex);
257 ptyarrfree(newpt, newnpty);
258 goto limit_reached;
259 }
260 newnpty = maxptys;
261 }
262
263 /*
264 * If the pty array was not enlarged while we were waiting
265 * for mutex, copy current contents of pt_softc[] to newly
266 * allocated array and start using the new bigger array.
267 */
268 if (newnpty > npty) {
269 memcpy(newpt, pt_softc, npty*sizeof(struct pt_softc *));
270 oldpt = pt_softc;
271 oldnpty = npty;
272 pt_softc = newpt;
273 npty = newnpty;
274 } else {
275 /* was enlarged when waited for lock, free new space */
276 oldpt = newpt;
277 oldnpty = newnpty;
278 }
279
280 mutex_exit(&pt_softc_mutex);
281 ptyarrfree(oldpt, oldnpty);
282 }
283
284 /*
285 * If the entry is not yet allocated, allocate one. The mutex is
286 * needed so that the state of pt_softc[] array is consistant
287 * in case it has been lengthened above.
288 */
289 if (!pt_softc[ptn]) {
290 pti = kmem_zalloc(sizeof(*pti), KM_SLEEP);
291
292 selinit(&pti->pt_selr);
293 selinit(&pti->pt_selw);
294 pti->pt_tty = tty_alloc();
295
296 mutex_enter(&pt_softc_mutex);
297
298 /*
299 * Check the entry again - it might have been
300 * added while we were waiting for mutex.
301 */
302 if (pt_softc[ptn]) {
303 mutex_exit(&pt_softc_mutex);
304 tty_free(pti->pt_tty);
305 seldestroy(&pti->pt_selr);
306 seldestroy(&pti->pt_selw);
307 kmem_free(pti, sizeof(*pti));
308 return 0;
309 }
310 tty_attach(pti->pt_tty);
311 pt_softc[ptn] = pti;
312
313 mutex_exit(&pt_softc_mutex);
314 }
315
316 return 0;
317 }
318
319 /*
320 * Set maxpty in thread-safe way. Returns 0 in case of error, otherwise
321 * new value of maxptys.
322 */
323 int
pty_maxptys(int newmax,int set)324 pty_maxptys(int newmax, int set)
325 {
326 if (!set)
327 return maxptys;
328
329 /*
330 * We have to grab the pt_softc lock, so that we would pick correct
331 * value of npty (might be modified in pty_check()).
332 */
333 mutex_enter(&pt_softc_mutex);
334
335 /*
336 * The value cannot be set to value lower than the highest pty
337 * number ever allocated.
338 */
339 if (newmax >= npty)
340 maxptys = newmax;
341 else
342 newmax = 0;
343
344 mutex_exit(&pt_softc_mutex);
345
346 return newmax;
347 }
348
349 /*
350 * Establish n (or default if n is 1) ptys in the system.
351 */
352 void
ptyattach(int n)353 ptyattach(int n)
354 {
355
356 mutex_init(&pt_softc_mutex, MUTEX_DEFAULT, IPL_NONE);
357
358 /* maybe should allow 0 => none? */
359 if (n <= 1)
360 n = DEFAULT_NPTYS;
361 pt_softc = ptyarralloc(n);
362 npty = n;
363 #ifndef NO_DEV_PTM
364 ptmattach(1);
365 #endif
366 }
367
368 /*ARGSUSED*/
369 int
ptsopen(dev_t dev,int flag,int devtype,struct lwp * l)370 ptsopen(dev_t dev, int flag, int devtype, struct lwp *l)
371 {
372 struct pt_softc *pti;
373 struct tty *tp;
374 int error;
375 int ptn = minor(dev);
376
377 if ((error = pty_check(ptn)) != 0)
378 return error;
379
380 mutex_spin_enter(&tty_lock);
381 pti = pt_softc[ptn];
382 tp = pti->pt_tty;
383 if (!ISSET(tp->t_state, TS_ISOPEN)) {
384 tp->t_dev = dev;
385 ttychars(tp); /* Set up default chars */
386 tp->t_iflag = TTYDEF_IFLAG;
387 tp->t_oflag = TTYDEF_OFLAG;
388 tp->t_lflag = TTYDEF_LFLAG;
389 tp->t_cflag = TTYDEF_CFLAG;
390 tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
391 ttsetwater(tp); /* would be done in xxparam() */
392 } else if (kauth_authorize_device_tty(l->l_cred, KAUTH_DEVICE_TTY_OPEN,
393 tp) != 0) {
394 mutex_spin_exit(&tty_lock);
395 return EBUSY;
396 }
397 if (tp->t_oproc) /* Ctrlr still around. */
398 SET(tp->t_state, TS_CARR_ON);
399 if (!ISSET(flag, O_NONBLOCK)) {
400 while (!ISSET(tp->t_state, TS_CARR_ON)) {
401 tp->t_wopen++;
402 error = ttysleep(tp, &tp->t_rawcv, true, 0);
403 tp->t_wopen--;
404 if (error != 0) {
405 mutex_spin_exit(&tty_lock);
406 return error;
407 }
408 }
409 }
410 mutex_spin_exit(&tty_lock);
411 error = (*tp->t_linesw->l_open)(dev, tp);
412 ptcwakeup(tp, FREAD|FWRITE);
413 return error;
414 }
415
416 int
ptsclose(dev_t dev,int flag,int mode,struct lwp * l)417 ptsclose(dev_t dev, int flag, int mode, struct lwp *l)
418 {
419 struct pt_softc *pti = pt_softc[minor(dev)];
420 struct tty *tp = pti->pt_tty;
421 int error;
422
423 error = (*tp->t_linesw->l_close)(tp, flag);
424 error |= ttyclose(tp);
425 ptcwakeup(tp, FREAD|FWRITE);
426 return error;
427 }
428
429 int
ptsread(dev_t dev,struct uio * uio,int flag)430 ptsread(dev_t dev, struct uio *uio, int flag)
431 {
432 struct proc *p = curproc;
433 struct pt_softc *pti = pt_softc[minor(dev)];
434 struct tty *tp = pti->pt_tty;
435 int error = 0;
436 int cc, c;
437
438 again:
439 if (pti->pt_flags & PF_REMOTE) {
440 mutex_spin_enter(&tty_lock);
441 while (isbackground(p, tp)) { /* XXXSMP */
442 if (sigismasked(curlwp, SIGTTIN) ||
443 p->p_pgrp->pg_jobc == 0 ||
444 p->p_lflag & PL_PPWAIT) {
445 mutex_spin_exit(&tty_lock);
446 return EIO;
447 }
448 ttysig(tp, TTYSIG_PG1, SIGTTIN);
449 error = ttypause(tp, hz);
450 if (error != 0) {
451 mutex_spin_exit(&tty_lock);
452 return error;
453 }
454 }
455 if (tp->t_canq.c_cc == 0) {
456 if (flag & IO_NDELAY) {
457 mutex_spin_exit(&tty_lock);
458 return EWOULDBLOCK;
459 }
460 error = ttysleep(tp, &tp->t_cancv, true, 0);
461 mutex_spin_exit(&tty_lock);
462 if (error != 0)
463 return error;
464 goto again;
465 }
466 while(error == 0 && tp->t_canq.c_cc > 1 && uio->uio_resid > 0) {
467 c = getc(&tp->t_canq);
468 mutex_spin_exit(&tty_lock);
469 error = ureadc(c, uio);
470 mutex_spin_enter(&tty_lock);
471 /* Re-check terminal state here? */
472 }
473 if (tp->t_canq.c_cc == 1)
474 (void) getc(&tp->t_canq);
475 cc = tp->t_canq.c_cc;
476 mutex_spin_exit(&tty_lock);
477 if (cc)
478 return error;
479 } else if (tp->t_oproc)
480 error = (*tp->t_linesw->l_read)(tp, uio, flag);
481 ptcwakeup(tp, FWRITE);
482 return error;
483 }
484
485 /*
486 * Write to pseudo-tty.
487 * Wakeups of controlling tty will happen
488 * indirectly, when tty driver calls ptsstart.
489 */
490 int
ptswrite(dev_t dev,struct uio * uio,int flag)491 ptswrite(dev_t dev, struct uio *uio, int flag)
492 {
493 struct pt_softc *pti = pt_softc[minor(dev)];
494 struct tty *tp = pti->pt_tty;
495
496 if (tp->t_oproc == NULL)
497 return EIO;
498 return (*tp->t_linesw->l_write)(tp, uio, flag);
499 }
500
501 /*
502 * Poll pseudo-tty.
503 */
504 int
ptspoll(dev_t dev,int events,struct lwp * l)505 ptspoll(dev_t dev, int events, struct lwp *l)
506 {
507 struct pt_softc *pti = pt_softc[minor(dev)];
508 struct tty *tp = pti->pt_tty;
509
510 if (tp->t_oproc == NULL)
511 return POLLHUP;
512
513 return (*tp->t_linesw->l_poll)(tp, events, l);
514 }
515
516 /*
517 * Start output on pseudo-tty.
518 * Wake up process polling or sleeping for input from controlling tty.
519 */
520 void
ptsstart(struct tty * tp)521 ptsstart(struct tty *tp)
522 {
523 struct pt_softc *pti;
524
525 KASSERT(tp->t_dev != NODEV);
526 pti = pt_softc[minor(tp->t_dev)];
527
528 KASSERT(mutex_owned(&tty_lock));
529
530 if (ISSET(tp->t_state, TS_TTSTOP))
531 return;
532 if (pti->pt_flags & PF_STOPPED) {
533 pti->pt_flags &= ~PF_STOPPED;
534 pti->pt_send = TIOCPKT_START;
535 }
536
537 selnotify(&pti->pt_selr, 0, NOTE_SUBMIT);
538 cv_broadcast(&tp->t_outcvf);
539 }
540
541 /*
542 * Stop output.
543 */
544 void
ptsstop(struct tty * tp,int flush)545 ptsstop(struct tty *tp, int flush)
546 {
547 struct pt_softc *pti;
548
549 KASSERT(tp->t_dev != NODEV);
550 pti = pt_softc[minor(tp->t_dev)];
551
552 KASSERT(mutex_owned(&tty_lock));
553
554 /* note: FLUSHREAD and FLUSHWRITE already ok */
555 CTASSERT(TIOCPKT_FLUSHREAD == FREAD);
556 CTASSERT(TIOCPKT_FLUSHWRITE == FWRITE);
557 if (flush == 0) {
558 flush = TIOCPKT_STOP;
559 pti->pt_flags |= PF_STOPPED;
560 } else
561 pti->pt_flags &= ~PF_STOPPED;
562 pti->pt_send |= flush;
563
564 /* change of perspective */
565 if (flush & FREAD) {
566 selnotify(&pti->pt_selw, 0, NOTE_SUBMIT);
567 cv_broadcast(&tp->t_rawcvf);
568 }
569 if (flush & FWRITE) {
570 selnotify(&pti->pt_selr, 0, NOTE_SUBMIT);
571 cv_broadcast(&tp->t_outcvf);
572 }
573 }
574
575 void
ptcwakeup(struct tty * tp,int flag)576 ptcwakeup(struct tty *tp, int flag)
577 {
578 struct pt_softc *pti;
579
580 if (tp->t_dev == NODEV)
581 return; /* client side not open yet */
582
583 pti = pt_softc[minor(tp->t_dev)];
584 KASSERT(pti != NULL);
585
586 mutex_spin_enter(&tty_lock);
587 if (flag & FREAD) {
588 selnotify(&pti->pt_selr, 0, NOTE_SUBMIT);
589 cv_broadcast(&tp->t_outcvf);
590 }
591 if (flag & FWRITE) {
592 selnotify(&pti->pt_selw, 0, NOTE_SUBMIT);
593 cv_broadcast(&tp->t_rawcvf);
594 }
595 mutex_spin_exit(&tty_lock);
596 }
597
598 /*ARGSUSED*/
599 int
ptcopen(dev_t dev,int flag,int devtype,struct lwp * l)600 ptcopen(dev_t dev, int flag, int devtype, struct lwp *l)
601 {
602 struct pt_softc *pti;
603 struct tty *tp;
604 int error;
605 int ptn = minor(dev);
606
607 if ((error = pty_check(ptn)) != 0)
608 return error;
609
610 pti = pt_softc[ptn];
611 tp = pti->pt_tty;
612
613 mutex_spin_enter(&tty_lock);
614 if (tp->t_oproc) {
615 mutex_spin_exit(&tty_lock);
616 return EIO;
617 }
618 tp->t_dev = dev;
619 tp->t_oproc = ptsstart;
620 mutex_spin_exit(&tty_lock);
621 (void)(*tp->t_linesw->l_modem)(tp, 1);
622 CLR(tp->t_lflag, EXTPROC);
623 pti->pt_flags = 0;
624 pti->pt_send = 0;
625 pti->pt_ucntl = 0;
626 return 0;
627 }
628
629 /*ARGSUSED*/
630 int
ptcclose(dev_t dev,int flag,int devtype,struct lwp * l)631 ptcclose(dev_t dev, int flag, int devtype, struct lwp *l)
632 {
633 struct pt_softc *pti = pt_softc[minor(dev)];
634 struct tty *tp = pti->pt_tty;
635
636 (void)(*tp->t_linesw->l_modem)(tp, 0);
637 mutex_spin_enter(&tty_lock);
638 CLR(tp->t_state, TS_CARR_ON);
639 tp->t_oproc = NULL; /* mark closed */
640 mutex_spin_exit(&tty_lock);
641 return 0;
642 }
643
644 int
ptcread(dev_t dev,struct uio * uio,int flag)645 ptcread(dev_t dev, struct uio *uio, int flag)
646 {
647 struct pt_softc *pti = pt_softc[minor(dev)];
648 struct tty *tp = pti->pt_tty;
649 u_char bf[BUFSIZ];
650 int error = 0, cc;
651 int c;
652
653 if (uio->uio_resid <= 0)
654 return EINVAL;
655
656 /*
657 * We want to block until the slave
658 * is open, and there's something to read;
659 * but if we lost the slave or we're NBIO,
660 * then return the appropriate error instead.
661 */
662 mutex_spin_enter(&tty_lock);
663 for (;;) {
664 if (ISSET(tp->t_state, TS_ISOPEN)) {
665 if (pti->pt_flags & PF_PKT && (c = pti->pt_send)) {
666 pti->pt_send = 0;
667 mutex_spin_exit(&tty_lock);
668 error = ureadc(c, uio);
669 if (error != 0)
670 return error;
671 /*
672 * Since we don't have the tty locked, there's
673 * a risk of messing up `t_termios'. This is
674 * relevant only if the tty got closed and then
675 * opened again while we were out uiomoving.
676 */
677 if (c & TIOCPKT_IOCTL) {
678 cc = uimin(uio->uio_resid,
679 sizeof(tp->t_termios));
680 uiomove((void *) &tp->t_termios,
681 cc, uio);
682 }
683 return 0;
684 }
685 if (pti->pt_flags & PF_UCNTL && (c = pti->pt_ucntl)) {
686 pti->pt_ucntl = 0;
687 mutex_spin_exit(&tty_lock);
688 error = ureadc(c, uio);
689 if (error != 0)
690 return error;
691 return 0;
692 }
693 if (tp->t_outq.c_cc && !ISSET(tp->t_state, TS_TTSTOP))
694 break;
695 }
696 if (!ISSET(tp->t_state, TS_CARR_ON)) {
697 error = 0; /* EOF */
698 goto out;
699 }
700 if (flag & IO_NDELAY) {
701 error = EWOULDBLOCK;
702 goto out;
703 }
704 error = cv_wait_sig(&tp->t_outcvf, &tty_lock);
705 if (error != 0)
706 goto out;
707 }
708
709 if (pti->pt_flags & (PF_PKT|PF_UCNTL)) {
710 mutex_spin_exit(&tty_lock);
711 error = ureadc(0, uio);
712 mutex_spin_enter(&tty_lock);
713 if (error == 0 && !ISSET(tp->t_state, TS_ISOPEN))
714 error = EIO;
715 }
716 while (uio->uio_resid > 0 && error == 0) {
717 cc = q_to_b(&tp->t_outq, bf, uimin(uio->uio_resid, BUFSIZ));
718 if (cc <= 0)
719 break;
720 mutex_spin_exit(&tty_lock);
721 error = uiomove(bf, cc, uio);
722 mutex_spin_enter(&tty_lock);
723 if (error == 0 && !ISSET(tp->t_state, TS_ISOPEN))
724 error = EIO;
725 }
726 ttypull(tp);
727 out:
728 mutex_spin_exit(&tty_lock);
729 return error;
730 }
731
732
733 int
ptcwrite(dev_t dev,struct uio * uio,int flag)734 ptcwrite(dev_t dev, struct uio *uio, int flag)
735 {
736 struct pt_softc *pti = pt_softc[minor(dev)];
737 struct tty *tp = pti->pt_tty;
738 u_char *cp = NULL;
739 int cc = 0;
740 u_char locbuf[BUFSIZ];
741 int cnt = 0;
742 int error = 0;
743
744 again:
745 mutex_spin_enter(&tty_lock);
746 if (!ISSET(tp->t_state, TS_ISOPEN))
747 goto block;
748 if (pti->pt_flags & PF_REMOTE) {
749 if (tp->t_canq.c_cc)
750 goto block;
751 while (uio->uio_resid > 0 && tp->t_canq.c_cc < TTYHOG) {
752 if (cc == 0) {
753 cc = uimin(uio->uio_resid, BUFSIZ);
754 cc = uimin(cc, TTYHOG - tp->t_canq.c_cc);
755 cp = locbuf;
756 mutex_spin_exit(&tty_lock);
757 error = uiomove(cp, cc, uio);
758 if (error != 0)
759 return error;
760 mutex_spin_enter(&tty_lock);
761 /* check again for safety */
762 if (!ISSET(tp->t_state, TS_ISOPEN)) {
763 /*
764 * adjust for data copied in but not
765 * written
766 */
767 uio->uio_resid += cc;
768 error = EIO;
769 goto out;
770 }
771 }
772 if (cc) {
773 cc = b_to_q(cp, cc, &tp->t_outq);
774 if (cc > 0)
775 goto block;
776 }
777 }
778 (void) putc(0, &tp->t_canq);
779 ttwakeup(tp);
780 cv_broadcast(&tp->t_cancv);
781 error = 0;
782 goto out;
783 }
784 while (uio->uio_resid > 0) {
785 if (cc == 0) {
786 cc = uimin(uio->uio_resid, BUFSIZ);
787 cp = locbuf;
788 mutex_spin_exit(&tty_lock);
789 error = uiomove(cp, cc, uio);
790 if (error != 0)
791 return error;
792 mutex_spin_enter(&tty_lock);
793 /* check again for safety */
794 if (!ISSET(tp->t_state, TS_ISOPEN)) {
795 /* adjust for data copied in but not written */
796 uio->uio_resid += cc;
797 error = EIO;
798 goto out;
799 }
800 }
801 while (cc > 0) {
802 int used = tp->t_rawq.c_cc + tp->t_canq.c_cc;
803 int canon = ISSET(tp->t_lflag, ICANON) ? 1 : 0;
804 /*
805 * We need space for 2 characters if canonical
806 * because we might need to print ^C
807 */
808 if (used >= (TTYHOG - canon) &&
809 (tp->t_canq.c_cc > 0 || !canon)) {
810 cv_broadcast(&tp->t_rawcv);
811 goto block;
812 }
813 /*
814 * XXX - should change l_rint to be called with lock
815 * see also tty.c:ttyinput_wlock()
816 */
817 mutex_spin_exit(&tty_lock);
818 (*tp->t_linesw->l_rint)(*cp++, tp);
819 mutex_spin_enter(&tty_lock);
820 cnt++;
821 cc--;
822 }
823 }
824 error = 0;
825 goto out;
826
827 block:
828 /*
829 * Come here to wait for slave to open, for space
830 * in outq, or space in rawq.
831 */
832 if (!ISSET(tp->t_state, TS_CARR_ON)) {
833 /* adjust for data copied in but not written */
834 uio->uio_resid += cc;
835 error = EIO;
836 goto out;
837 }
838 if (flag & IO_NDELAY) {
839 /* adjust for data copied in but not written */
840 uio->uio_resid += cc;
841 error = cnt == 0 ? EWOULDBLOCK : 0;
842 goto out;
843 }
844 error = cv_wait_sig(&tp->t_rawcvf, &tty_lock);
845 mutex_spin_exit(&tty_lock);
846 if (error != 0) {
847 /* adjust for data copied in but not written */
848 uio->uio_resid += cc;
849 return error;
850 }
851 goto again;
852
853 out:
854 mutex_spin_exit(&tty_lock);
855 return error;
856 }
857
858 int
ptcpoll(dev_t dev,int events,struct lwp * l)859 ptcpoll(dev_t dev, int events, struct lwp *l)
860 {
861 struct pt_softc *pti = pt_softc[minor(dev)];
862 struct tty *tp = pti->pt_tty;
863 int revents = 0;
864
865 mutex_spin_enter(&tty_lock);
866
867 if (events & (POLLIN | POLLRDNORM))
868 if (ISSET(tp->t_state, TS_ISOPEN) &&
869 ((tp->t_outq.c_cc > 0 && !ISSET(tp->t_state, TS_TTSTOP)) ||
870 ((pti->pt_flags & PF_PKT) && pti->pt_send) ||
871 ((pti->pt_flags & PF_UCNTL) && pti->pt_ucntl)))
872 revents |= events & (POLLIN | POLLRDNORM);
873
874 if (events & (POLLOUT | POLLWRNORM))
875 if (ISSET(tp->t_state, TS_ISOPEN) &&
876 ((pti->pt_flags & PF_REMOTE) ?
877 (tp->t_canq.c_cc == 0) :
878 ((tp->t_rawq.c_cc + tp->t_canq.c_cc < TTYHOG-2) ||
879 (tp->t_canq.c_cc == 0 && ISSET(tp->t_lflag, ICANON)))))
880 revents |= events & (POLLOUT | POLLWRNORM);
881
882 if (events & POLLHUP)
883 if (!ISSET(tp->t_state, TS_CARR_ON))
884 revents |= POLLHUP;
885
886 if (revents == 0) {
887 if (events & (POLLIN | POLLHUP | POLLRDNORM))
888 selrecord(l, &pti->pt_selr);
889
890 if (events & (POLLOUT | POLLWRNORM))
891 selrecord(l, &pti->pt_selw);
892 }
893
894 mutex_spin_exit(&tty_lock);
895
896 return revents;
897 }
898
899 static void
filt_ptcrdetach(struct knote * kn)900 filt_ptcrdetach(struct knote *kn)
901 {
902 struct pt_softc *pti;
903
904 pti = kn->kn_hook;
905
906 mutex_spin_enter(&tty_lock);
907 selremove_knote(&pti->pt_selr, kn);
908 mutex_spin_exit(&tty_lock);
909 }
910
911 static int
filt_ptcread(struct knote * kn,long hint)912 filt_ptcread(struct knote *kn, long hint)
913 {
914 struct pt_softc *pti;
915 struct tty *tp;
916 int canread;
917
918 pti = kn->kn_hook;
919 tp = pti->pt_tty;
920
921 if ((hint & NOTE_SUBMIT) == 0) {
922 mutex_spin_enter(&tty_lock);
923 }
924
925 canread = (ISSET(tp->t_state, TS_ISOPEN) &&
926 ((tp->t_outq.c_cc > 0 && !ISSET(tp->t_state, TS_TTSTOP)) ||
927 ((pti->pt_flags & PF_PKT) && pti->pt_send) ||
928 ((pti->pt_flags & PF_UCNTL) && pti->pt_ucntl)));
929
930 if (canread) {
931 /*
932 * c_cc is number of characters after output post-processing;
933 * the amount of data actually read(2) depends on
934 * setting of input flags for the terminal.
935 */
936 kn->kn_data = tp->t_outq.c_cc;
937 if (((pti->pt_flags & PF_PKT) && pti->pt_send) ||
938 ((pti->pt_flags & PF_UCNTL) && pti->pt_ucntl))
939 kn->kn_data++;
940 }
941 if (!ISSET(tp->t_state, TS_CARR_ON)) {
942 knote_set_eof(kn, 0);
943 canread = 1;
944 }
945
946 if ((hint & NOTE_SUBMIT) == 0) {
947 mutex_spin_exit(&tty_lock);
948 }
949
950 return canread;
951 }
952
953 static void
filt_ptcwdetach(struct knote * kn)954 filt_ptcwdetach(struct knote *kn)
955 {
956 struct pt_softc *pti;
957
958 pti = kn->kn_hook;
959
960 mutex_spin_enter(&tty_lock);
961 selremove_knote(&pti->pt_selw, kn);
962 mutex_spin_exit(&tty_lock);
963 }
964
965 static int
filt_ptcwrite(struct knote * kn,long hint)966 filt_ptcwrite(struct knote *kn, long hint)
967 {
968 struct pt_softc *pti;
969 struct tty *tp;
970 int canwrite;
971 int nwrite;
972
973 pti = kn->kn_hook;
974 tp = pti->pt_tty;
975
976 if ((hint & NOTE_SUBMIT) == 0) {
977 mutex_spin_enter(&tty_lock);
978 }
979
980 canwrite = (ISSET(tp->t_state, TS_ISOPEN) &&
981 ((pti->pt_flags & PF_REMOTE) ?
982 (tp->t_canq.c_cc == 0) :
983 ((tp->t_rawq.c_cc + tp->t_canq.c_cc < TTYHOG-2) ||
984 (tp->t_canq.c_cc == 0 && ISSET(tp->t_lflag, ICANON)))));
985
986 if (canwrite) {
987 if (pti->pt_flags & PF_REMOTE)
988 nwrite = tp->t_canq.c_cn;
989 else {
990 /* this is guaranteed to be > 0 due to above check */
991 nwrite = tp->t_canq.c_cn
992 - (tp->t_rawq.c_cc + tp->t_canq.c_cc);
993 }
994 kn->kn_data = nwrite;
995 }
996
997 if ((hint & NOTE_SUBMIT) == 0) {
998 mutex_spin_exit(&tty_lock);
999 }
1000
1001 return canwrite;
1002 }
1003
1004 static const struct filterops ptcread_filtops = {
1005 .f_flags = FILTEROP_ISFD | FILTEROP_MPSAFE,
1006 .f_attach = NULL,
1007 .f_detach = filt_ptcrdetach,
1008 .f_event = filt_ptcread,
1009 };
1010
1011 static const struct filterops ptcwrite_filtops = {
1012 .f_flags = FILTEROP_ISFD | FILTEROP_MPSAFE,
1013 .f_attach = NULL,
1014 .f_detach = filt_ptcwdetach,
1015 .f_event = filt_ptcwrite,
1016 };
1017
1018 int
ptckqfilter(dev_t dev,struct knote * kn)1019 ptckqfilter(dev_t dev, struct knote *kn)
1020 {
1021 struct pt_softc *pti = pt_softc[minor(dev)];
1022 struct selinfo *sip;
1023
1024 switch (kn->kn_filter) {
1025 case EVFILT_READ:
1026 sip = &pti->pt_selr;
1027 kn->kn_fop = &ptcread_filtops;
1028 break;
1029 case EVFILT_WRITE:
1030 sip = &pti->pt_selw;
1031 kn->kn_fop = &ptcwrite_filtops;
1032 break;
1033 default:
1034 return EINVAL;
1035 }
1036
1037 kn->kn_hook = pti;
1038
1039 mutex_spin_enter(&tty_lock);
1040 selrecord_knote(sip, kn);
1041 mutex_spin_exit(&tty_lock);
1042
1043 return 0;
1044 }
1045
1046 struct tty *
ptytty(dev_t dev)1047 ptytty(dev_t dev)
1048 {
1049 struct pt_softc *pti = pt_softc[minor(dev)];
1050 struct tty *tp = pti->pt_tty;
1051
1052 return tp;
1053 }
1054
1055 /*ARGSUSED*/
1056 int
ptyioctl(dev_t dev,u_long cmd,void * data,int flag,struct lwp * l)1057 ptyioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *l)
1058 {
1059 struct pt_softc *pti = pt_softc[minor(dev)];
1060 struct tty *tp = pti->pt_tty;
1061 const struct cdevsw *cdev;
1062 u_char *cc = tp->t_cc;
1063 int stop, error, sig;
1064 #ifndef NO_DEV_PTM
1065 struct mount *mp;
1066 #endif
1067
1068 /*
1069 * IF CONTROLLER STTY THEN MUST FLUSH TO PREVENT A HANG.
1070 * ttywflush(tp) will hang if there are characters in the outq.
1071 */
1072 if (cmd == TIOCEXT) {
1073 /*
1074 * When the EXTPROC bit is being toggled, we need
1075 * to send an TIOCPKT_IOCTL if the packet driver
1076 * is turned on.
1077 */
1078 if (*(int *)data) {
1079 if (pti->pt_flags & PF_PKT) {
1080 pti->pt_send |= TIOCPKT_IOCTL;
1081 ptcwakeup(tp, FREAD);
1082 }
1083 SET(tp->t_lflag, EXTPROC);
1084 } else {
1085 if (ISSET(tp->t_lflag, EXTPROC) &&
1086 (pti->pt_flags & PF_PKT)) {
1087 pti->pt_send |= TIOCPKT_IOCTL;
1088 ptcwakeup(tp, FREAD);
1089 }
1090 CLR(tp->t_lflag, EXTPROC);
1091 }
1092 return(0);
1093 }
1094
1095 #ifndef NO_DEV_PTM
1096 /* Allow getting the name from either the master or the slave */
1097 if (cmd == TIOCPTSNAME) {
1098 if ((error = pty_getmp(l, &mp)) != 0)
1099 return error;
1100 return pty_fill_ptmget(l, dev, -1, -1, data, mp);
1101 }
1102 #endif
1103
1104 cdev = cdevsw_lookup(dev);
1105 if (cdev != NULL && cdev->d_open == ptcopen)
1106 switch (cmd) {
1107 #ifndef NO_DEV_PTM
1108 case TIOCGRANTPT:
1109 if ((error = pty_getmp(l, &mp)) != 0)
1110 return error;
1111 return pty_grant_slave(l, dev, mp);
1112 #endif
1113
1114 case TIOCGPGRP:
1115 /*
1116 * We avoid calling ttioctl on the controller since,
1117 * in that case, tp must be the controlling terminal.
1118 */
1119 *(int *)data = tp->t_pgrp ? tp->t_pgrp->pg_id : 0;
1120 return 0;
1121
1122 case TIOCPKT:
1123 if (*(int *)data) {
1124 if (pti->pt_flags & PF_UCNTL)
1125 return EINVAL;
1126 pti->pt_flags |= PF_PKT;
1127 } else
1128 pti->pt_flags &= ~PF_PKT;
1129 return 0;
1130
1131 case TIOCUCNTL:
1132 if (*(int *)data) {
1133 if (pti->pt_flags & PF_PKT)
1134 return EINVAL;
1135 pti->pt_flags |= PF_UCNTL;
1136 } else
1137 pti->pt_flags &= ~PF_UCNTL;
1138 return 0;
1139
1140 case TIOCREMOTE:
1141 if (*(int *)data)
1142 pti->pt_flags |= PF_REMOTE;
1143 else
1144 pti->pt_flags &= ~PF_REMOTE;
1145 mutex_spin_enter(&tty_lock);
1146 ttyflush(tp, FREAD|FWRITE);
1147 mutex_spin_exit(&tty_lock);
1148 return 0;
1149
1150 case TIOCSETP:
1151 case TIOCSETN:
1152 case TIOCSETD:
1153 case TIOCSETA:
1154 case TIOCSETAW:
1155 case TIOCSETAF:
1156 mutex_spin_enter(&tty_lock);
1157 ndflush(&tp->t_outq, tp->t_outq.c_cc);
1158 mutex_spin_exit(&tty_lock);
1159 break;
1160
1161 case TIOCSIG:
1162 sig = (int)(long)*(void **)data;
1163 if (sig <= 0 || sig >= NSIG)
1164 return EINVAL;
1165 mutex_spin_enter(&tty_lock);
1166 if (!ISSET(tp->t_lflag, NOFLSH))
1167 ttyflush(tp, FREAD|FWRITE);
1168 tp->t_state |= TS_SIGINFO;
1169 ttysig(tp, TTYSIG_PG1, sig);
1170 mutex_spin_exit(&tty_lock);
1171 return 0;
1172
1173 case FIONREAD:
1174 mutex_spin_enter(&tty_lock);
1175 *(int *)data = tp->t_outq.c_cc;
1176 mutex_spin_exit(&tty_lock);
1177 return 0;
1178 }
1179
1180 error = (*tp->t_linesw->l_ioctl)(tp, cmd, data, flag, l);
1181 if (error == EPASSTHROUGH)
1182 error = ttioctl(tp, cmd, data, flag, l);
1183 if (error == EPASSTHROUGH) {
1184 if (pti->pt_flags & PF_UCNTL &&
1185 (cmd & ~0xff) == UIOCCMD(0)) {
1186 if (cmd & 0xff) {
1187 pti->pt_ucntl = (u_char)cmd;
1188 ptcwakeup(tp, FREAD);
1189 }
1190 return 0;
1191 }
1192 }
1193 /*
1194 * If external processing and packet mode send ioctl packet.
1195 */
1196 if (ISSET(tp->t_lflag, EXTPROC) && (pti->pt_flags & PF_PKT)) {
1197 switch(cmd) {
1198 case TIOCSETA:
1199 case TIOCSETAW:
1200 case TIOCSETAF:
1201 case TIOCSETP:
1202 case TIOCSETN:
1203 case TIOCSETC:
1204 case TIOCSLTC:
1205 case TIOCLBIS:
1206 case TIOCLBIC:
1207 case TIOCLSET:
1208 pti->pt_send |= TIOCPKT_IOCTL;
1209 ptcwakeup(tp, FREAD);
1210 default:
1211 break;
1212 }
1213 }
1214 stop = ISSET(tp->t_iflag, IXON) && CCEQ(cc[VSTOP], CTRL('s'))
1215 && CCEQ(cc[VSTART], CTRL('q'));
1216 if (pti->pt_flags & PF_NOSTOP) {
1217 if (stop) {
1218 pti->pt_send &= ~TIOCPKT_NOSTOP;
1219 pti->pt_send |= TIOCPKT_DOSTOP;
1220 pti->pt_flags &= ~PF_NOSTOP;
1221 ptcwakeup(tp, FREAD);
1222 }
1223 } else {
1224 if (!stop) {
1225 pti->pt_send &= ~TIOCPKT_DOSTOP;
1226 pti->pt_send |= TIOCPKT_NOSTOP;
1227 pti->pt_flags |= PF_NOSTOP;
1228 ptcwakeup(tp, FREAD);
1229 }
1230 }
1231 return error;
1232 }
1233