1 /*-
2 * Copyright (c) 2008 Ed Schouten <ed@FreeBSD.org>
3 * All rights reserved.
4 *
5 * Portions of this software were developed under sponsorship from Snow
6 * B.V., the Netherlands.
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 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32
33 /* Add compatibility bits for FreeBSD. */
34 #define PTS_COMPAT
35 /* Add pty(4) compat bits. */
36 #define PTS_EXTERNAL
37 /* Add bits to make Linux binaries work. */
38 #define PTS_LINUX
39
40 #include <sys/param.h>
41 #include <sys/lock.h>
42 #include <sys/condvar.h>
43 #include <sys/conf.h>
44 #include <sys/fcntl.h>
45 #include <sys/file.h>
46 #include <sys/filedesc.h>
47 #include <sys/filio.h>
48 #include <sys/kernel.h>
49 #include <sys/limits.h>
50 #include <sys/malloc.h>
51 #include <sys/poll.h>
52 #include <sys/proc.h>
53 #include <sys/racct.h>
54 #include <sys/resourcevar.h>
55 #include <sys/serial.h>
56 #include <sys/stat.h>
57 #include <sys/syscall.h>
58 #include <sys/syscallsubr.h>
59 #include <sys/sysctl.h>
60 #include <sys/sysent.h>
61 #include <sys/sysproto.h>
62 #include <sys/systm.h>
63 #include <sys/tty.h>
64 #include <sys/ttycom.h>
65
66 #include <machine/stdarg.h>
67
68 /*
69 * Our utmp(5) format is limited to 8-byte TTY line names. This means
70 * we can at most allocate 1000 pseudo-terminals ("pts/999"). Allow
71 * users to increase this number, assuming they have manually increased
72 * UT_LINESIZE.
73 */
74 static struct unrhdr *pts_pool;
75
76 static MALLOC_DEFINE(M_PTS, "pts", "pseudo tty device");
77
78 /*
79 * Per-PTS structure.
80 *
81 * List of locks
82 * (t) locked by tty_lock()
83 * (c) const until freeing
84 */
85 struct pts_softc {
86 int pts_unit; /* (c) Device unit number. */
87 unsigned int pts_flags; /* (t) Device flags. */
88 #define PTS_PKT 0x1 /* Packet mode. */
89 #define PTS_FINISHED 0x2 /* Return errors on read()/write(). */
90 char pts_pkt; /* (t) Unread packet mode data. */
91
92 struct cv pts_inwait; /* (t) Blocking write() on master. */
93 struct selinfo pts_inpoll; /* (t) Select queue for write(). */
94 struct cv pts_outwait; /* (t) Blocking read() on master. */
95 struct selinfo pts_outpoll; /* (t) Select queue for read(). */
96
97 #ifdef PTS_EXTERNAL
98 struct cdev *pts_cdev; /* (c) Master device node. */
99 #endif /* PTS_EXTERNAL */
100
101 struct ucred *pts_cred; /* (c) Resource limit. */
102 };
103
104 /*
105 * Controller-side file operations.
106 */
107
108 static int
ptsdev_read(struct file * fp,struct uio * uio,struct ucred * active_cred,int flags,struct thread * td)109 ptsdev_read(struct file *fp, struct uio *uio, struct ucred *active_cred,
110 int flags, struct thread *td)
111 {
112 struct tty *tp = fp->f_data;
113 struct pts_softc *psc = tty_softc(tp);
114 int error = 0;
115 char pkt;
116
117 if (uio->uio_resid == 0)
118 return (0);
119
120 tty_lock(tp);
121
122 for (;;) {
123 /*
124 * Implement packet mode. When packet mode is turned on,
125 * the first byte contains a bitmask of events that
126 * occured (start, stop, flush, window size, etc).
127 */
128 if (psc->pts_flags & PTS_PKT && psc->pts_pkt) {
129 pkt = psc->pts_pkt;
130 psc->pts_pkt = 0;
131 tty_unlock(tp);
132
133 error = ureadc(pkt, uio);
134 return (error);
135 }
136
137 /*
138 * Transmit regular data.
139 *
140 * XXX: We shouldn't use ttydisc_getc_poll()! Even
141 * though in this implementation, there is likely going
142 * to be data, we should just call ttydisc_getc_uio()
143 * and use its return value to sleep.
144 */
145 if (ttydisc_getc_poll(tp)) {
146 if (psc->pts_flags & PTS_PKT) {
147 /*
148 * XXX: Small race. Fortunately PTY
149 * consumers aren't multithreaded.
150 */
151
152 tty_unlock(tp);
153 error = ureadc(TIOCPKT_DATA, uio);
154 if (error)
155 return (error);
156 tty_lock(tp);
157 }
158
159 error = ttydisc_getc_uio(tp, uio);
160 break;
161 }
162
163 /* Maybe the device isn't used anyway. */
164 if (psc->pts_flags & PTS_FINISHED)
165 break;
166
167 /* Wait for more data. */
168 if (fp->f_flag & O_NONBLOCK) {
169 error = EWOULDBLOCK;
170 break;
171 }
172 error = cv_wait_sig(&psc->pts_outwait, tp->t_mtx);
173 if (error != 0)
174 break;
175 }
176
177 tty_unlock(tp);
178
179 return (error);
180 }
181
182 static int
ptsdev_write(struct file * fp,struct uio * uio,struct ucred * active_cred,int flags,struct thread * td)183 ptsdev_write(struct file *fp, struct uio *uio, struct ucred *active_cred,
184 int flags, struct thread *td)
185 {
186 struct tty *tp = fp->f_data;
187 struct pts_softc *psc = tty_softc(tp);
188 char ib[256], *ibstart;
189 size_t iblen, rintlen;
190 int error = 0;
191
192 if (uio->uio_resid == 0)
193 return (0);
194
195 for (;;) {
196 ibstart = ib;
197 iblen = MIN(uio->uio_resid, sizeof ib);
198 error = uiomove(ib, iblen, uio);
199
200 tty_lock(tp);
201 if (error != 0) {
202 iblen = 0;
203 goto done;
204 }
205
206 /*
207 * When possible, avoid the slow path. rint_bypass()
208 * copies all input to the input queue at once.
209 */
210 MPASS(iblen > 0);
211 do {
212 rintlen = ttydisc_rint_simple(tp, ibstart, iblen);
213 ibstart += rintlen;
214 iblen -= rintlen;
215 if (iblen == 0) {
216 /* All data written. */
217 break;
218 }
219
220 /* Maybe the device isn't used anyway. */
221 if (psc->pts_flags & PTS_FINISHED) {
222 error = EIO;
223 goto done;
224 }
225
226 /* Wait for more data. */
227 if (fp->f_flag & O_NONBLOCK) {
228 error = EWOULDBLOCK;
229 goto done;
230 }
231
232 /* Wake up users on the slave side. */
233 ttydisc_rint_done(tp);
234 error = cv_wait_sig(&psc->pts_inwait, tp->t_mtx);
235 if (error != 0)
236 goto done;
237 } while (iblen > 0);
238
239 if (uio->uio_resid == 0)
240 break;
241 tty_unlock(tp);
242 }
243
244 done: ttydisc_rint_done(tp);
245 tty_unlock(tp);
246
247 /*
248 * Don't account for the part of the buffer that we couldn't
249 * pass to the TTY.
250 */
251 uio->uio_resid += iblen;
252 return (error);
253 }
254
255 static int
ptsdev_truncate(struct file * fp,off_t length,struct ucred * active_cred,struct thread * td)256 ptsdev_truncate(struct file *fp, off_t length, struct ucred *active_cred,
257 struct thread *td)
258 {
259
260 return (EINVAL);
261 }
262
263 static int
ptsdev_ioctl(struct file * fp,u_long cmd,void * data,struct ucred * active_cred,struct thread * td)264 ptsdev_ioctl(struct file *fp, u_long cmd, void *data,
265 struct ucred *active_cred, struct thread *td)
266 {
267 struct tty *tp = fp->f_data;
268 struct pts_softc *psc = tty_softc(tp);
269 int error = 0, sig;
270
271 switch (cmd) {
272 case FIODTYPE:
273 *(int *)data = D_TTY;
274 return (0);
275 case FIONBIO:
276 /* This device supports non-blocking operation. */
277 return (0);
278 case FIONREAD:
279 tty_lock(tp);
280 if (psc->pts_flags & PTS_FINISHED) {
281 /* Force read() to be called. */
282 *(int *)data = 1;
283 } else {
284 *(int *)data = ttydisc_getc_poll(tp);
285 }
286 tty_unlock(tp);
287 return (0);
288 case FIODGNAME: {
289 struct fiodgname_arg *fgn;
290 const char *p;
291 int i;
292
293 /* Reverse device name lookups, for ptsname() and ttyname(). */
294 fgn = data;
295 p = tty_devname(tp);
296 i = strlen(p) + 1;
297 if (i > fgn->len)
298 return (EINVAL);
299 return copyout(p, fgn->buf, i);
300 }
301
302 /*
303 * We need to implement TIOCGPGRP and TIOCGSID here again. When
304 * called on the pseudo-terminal master, it should not check if
305 * the terminal is the foreground terminal of the calling
306 * process.
307 *
308 * TIOCGETA is also implemented here. Various Linux PTY routines
309 * often call isatty(), which is implemented by tcgetattr().
310 */
311 #ifdef PTS_LINUX
312 case TIOCGETA:
313 /* Obtain terminal flags through tcgetattr(). */
314 tty_lock(tp);
315 *(struct termios*)data = tp->t_termios;
316 tty_unlock(tp);
317 return (0);
318 #endif /* PTS_LINUX */
319 case TIOCSETAF:
320 case TIOCSETAW:
321 /*
322 * We must make sure we turn tcsetattr() calls of TCSAFLUSH and
323 * TCSADRAIN into something different. If an application would
324 * call TCSAFLUSH or TCSADRAIN on the master descriptor, it may
325 * deadlock waiting for all data to be read.
326 */
327 cmd = TIOCSETA;
328 break;
329 #if defined(PTS_COMPAT) || defined(PTS_LINUX)
330 case TIOCGPTN:
331 /*
332 * Get the device unit number.
333 */
334 if (psc->pts_unit < 0)
335 return (ENOTTY);
336 *(unsigned int *)data = psc->pts_unit;
337 return (0);
338 #endif /* PTS_COMPAT || PTS_LINUX */
339 case TIOCGPGRP:
340 /* Get the foreground process group ID. */
341 tty_lock(tp);
342 if (tp->t_pgrp != NULL)
343 *(int *)data = tp->t_pgrp->pg_id;
344 else
345 *(int *)data = NO_PID;
346 tty_unlock(tp);
347 return (0);
348 case TIOCGSID:
349 /* Get the session leader process ID. */
350 tty_lock(tp);
351 if (tp->t_session == NULL)
352 error = ENOTTY;
353 else
354 *(int *)data = tp->t_session->s_sid;
355 tty_unlock(tp);
356 return (error);
357 case TIOCPTMASTER:
358 /* Yes, we are a pseudo-terminal master. */
359 return (0);
360 case TIOCSIG:
361 /* Signal the foreground process group. */
362 sig = *(int *)data;
363 if (sig < 1 || sig >= NSIG)
364 return (EINVAL);
365
366 tty_lock(tp);
367 tty_signal_pgrp(tp, sig);
368 tty_unlock(tp);
369 return (0);
370 case TIOCPKT:
371 /* Enable/disable packet mode. */
372 tty_lock(tp);
373 if (*(int *)data)
374 psc->pts_flags |= PTS_PKT;
375 else
376 psc->pts_flags &= ~PTS_PKT;
377 tty_unlock(tp);
378 return (0);
379 }
380
381 /* Just redirect this ioctl to the slave device. */
382 tty_lock(tp);
383 error = tty_ioctl(tp, cmd, data, fp->f_flag, td);
384 tty_unlock(tp);
385 if (error == ENOIOCTL)
386 error = ENOTTY;
387
388 return (error);
389 }
390
391 static int
ptsdev_poll(struct file * fp,int events,struct ucred * active_cred,struct thread * td)392 ptsdev_poll(struct file *fp, int events, struct ucred *active_cred,
393 struct thread *td)
394 {
395 struct tty *tp = fp->f_data;
396 struct pts_softc *psc = tty_softc(tp);
397 int revents = 0;
398
399 tty_lock(tp);
400
401 if (psc->pts_flags & PTS_FINISHED) {
402 /* Slave device is not opened. */
403 tty_unlock(tp);
404 return ((events & (POLLIN|POLLRDNORM)) | POLLHUP);
405 }
406
407 if (events & (POLLIN|POLLRDNORM)) {
408 /* See if we can getc something. */
409 if (ttydisc_getc_poll(tp) ||
410 (psc->pts_flags & PTS_PKT && psc->pts_pkt))
411 revents |= events & (POLLIN|POLLRDNORM);
412 }
413 if (events & (POLLOUT|POLLWRNORM)) {
414 /* See if we can rint something. */
415 if (ttydisc_rint_poll(tp))
416 revents |= events & (POLLOUT|POLLWRNORM);
417 }
418
419 /*
420 * No need to check for POLLHUP here. This device cannot be used
421 * as a callout device, which means we always have a carrier,
422 * because the master is.
423 */
424
425 if (revents == 0) {
426 /*
427 * This code might look misleading, but the naming of
428 * poll events on this side is the opposite of the slave
429 * device.
430 */
431 if (events & (POLLIN|POLLRDNORM))
432 selrecord(td, &psc->pts_outpoll);
433 if (events & (POLLOUT|POLLWRNORM))
434 selrecord(td, &psc->pts_inpoll);
435 }
436
437 tty_unlock(tp);
438
439 return (revents);
440 }
441
442 /*
443 * kqueue support.
444 */
445
446 static void
pts_kqops_read_detach(struct knote * kn)447 pts_kqops_read_detach(struct knote *kn)
448 {
449 struct file *fp = kn->kn_fp;
450 struct tty *tp = fp->f_data;
451 struct pts_softc *psc = tty_softc(tp);
452
453 knlist_remove(&psc->pts_outpoll.si_note, kn, 0);
454 }
455
456 static int
pts_kqops_read_event(struct knote * kn,long hint)457 pts_kqops_read_event(struct knote *kn, long hint)
458 {
459 struct file *fp = kn->kn_fp;
460 struct tty *tp = fp->f_data;
461 struct pts_softc *psc = tty_softc(tp);
462
463 if (psc->pts_flags & PTS_FINISHED) {
464 kn->kn_flags |= EV_EOF;
465 return (1);
466 } else {
467 kn->kn_data = ttydisc_getc_poll(tp);
468 return (kn->kn_data > 0);
469 }
470 }
471
472 static void
pts_kqops_write_detach(struct knote * kn)473 pts_kqops_write_detach(struct knote *kn)
474 {
475 struct file *fp = kn->kn_fp;
476 struct tty *tp = fp->f_data;
477 struct pts_softc *psc = tty_softc(tp);
478
479 knlist_remove(&psc->pts_inpoll.si_note, kn, 0);
480 }
481
482 static int
pts_kqops_write_event(struct knote * kn,long hint)483 pts_kqops_write_event(struct knote *kn, long hint)
484 {
485 struct file *fp = kn->kn_fp;
486 struct tty *tp = fp->f_data;
487 struct pts_softc *psc = tty_softc(tp);
488
489 if (psc->pts_flags & PTS_FINISHED) {
490 kn->kn_flags |= EV_EOF;
491 return (1);
492 } else {
493 kn->kn_data = ttydisc_rint_poll(tp);
494 return (kn->kn_data > 0);
495 }
496 }
497
498 static struct filterops pts_kqops_read = {
499 .f_isfd = 1,
500 .f_detach = pts_kqops_read_detach,
501 .f_event = pts_kqops_read_event,
502 };
503 static struct filterops pts_kqops_write = {
504 .f_isfd = 1,
505 .f_detach = pts_kqops_write_detach,
506 .f_event = pts_kqops_write_event,
507 };
508
509 static int
ptsdev_kqfilter(struct file * fp,struct knote * kn)510 ptsdev_kqfilter(struct file *fp, struct knote *kn)
511 {
512 struct tty *tp = fp->f_data;
513 struct pts_softc *psc = tty_softc(tp);
514 int error = 0;
515
516 tty_lock(tp);
517
518 switch (kn->kn_filter) {
519 case EVFILT_READ:
520 kn->kn_fop = &pts_kqops_read;
521 knlist_add(&psc->pts_outpoll.si_note, kn, 1);
522 break;
523 case EVFILT_WRITE:
524 kn->kn_fop = &pts_kqops_write;
525 knlist_add(&psc->pts_inpoll.si_note, kn, 1);
526 break;
527 default:
528 error = EINVAL;
529 break;
530 }
531
532 tty_unlock(tp);
533 return (error);
534 }
535
536 static int
ptsdev_stat(struct file * fp,struct stat * sb,struct ucred * active_cred,struct thread * td)537 ptsdev_stat(struct file *fp, struct stat *sb, struct ucred *active_cred,
538 struct thread *td)
539 {
540 struct tty *tp = fp->f_data;
541 #ifdef PTS_EXTERNAL
542 struct pts_softc *psc = tty_softc(tp);
543 #endif /* PTS_EXTERNAL */
544 struct cdev *dev = tp->t_dev;
545
546 /*
547 * According to POSIX, we must implement an fstat(). This also
548 * makes this implementation compatible with Linux binaries,
549 * because Linux calls fstat() on the pseudo-terminal master to
550 * obtain st_rdev.
551 *
552 * XXX: POSIX also mentions we must fill in st_dev, but how?
553 */
554
555 bzero(sb, sizeof *sb);
556 #ifdef PTS_EXTERNAL
557 if (psc->pts_cdev != NULL)
558 sb->st_ino = sb->st_rdev = dev2udev(psc->pts_cdev);
559 else
560 #endif /* PTS_EXTERNAL */
561 sb->st_ino = sb->st_rdev = tty_udev(tp);
562
563 sb->st_atim = dev->si_atime;
564 sb->st_ctim = dev->si_ctime;
565 sb->st_mtim = dev->si_mtime;
566 sb->st_uid = dev->si_uid;
567 sb->st_gid = dev->si_gid;
568 sb->st_mode = dev->si_mode | S_IFCHR;
569
570 return (0);
571 }
572
573 static int
ptsdev_close(struct file * fp,struct thread * td)574 ptsdev_close(struct file *fp, struct thread *td)
575 {
576 struct tty *tp = fp->f_data;
577
578 /* Deallocate TTY device. */
579 tty_lock(tp);
580 tty_rel_gone(tp);
581
582 /*
583 * Open of /dev/ptmx or /dev/ptyXX changes the type of file
584 * from DTYPE_VNODE to DTYPE_PTS. vn_open() increases vnode
585 * use count, we need to decrement it, and possibly do other
586 * required cleanup.
587 */
588 if (fp->f_vnode != NULL)
589 return (vnops.fo_close(fp, td));
590
591 return (0);
592 }
593
594 static struct fileops ptsdev_ops = {
595 .fo_read = ptsdev_read,
596 .fo_write = ptsdev_write,
597 .fo_truncate = ptsdev_truncate,
598 .fo_ioctl = ptsdev_ioctl,
599 .fo_poll = ptsdev_poll,
600 .fo_kqfilter = ptsdev_kqfilter,
601 .fo_stat = ptsdev_stat,
602 .fo_close = ptsdev_close,
603 .fo_chmod = invfo_chmod,
604 .fo_chown = invfo_chown,
605 .fo_sendfile = invfo_sendfile,
606 .fo_flags = DFLAG_PASSABLE,
607 };
608
609 /*
610 * Driver-side hooks.
611 */
612
613 static void
ptsdrv_outwakeup(struct tty * tp)614 ptsdrv_outwakeup(struct tty *tp)
615 {
616 struct pts_softc *psc = tty_softc(tp);
617
618 cv_broadcast(&psc->pts_outwait);
619 selwakeup(&psc->pts_outpoll);
620 KNOTE_LOCKED(&psc->pts_outpoll.si_note, 0);
621 }
622
623 static void
ptsdrv_inwakeup(struct tty * tp)624 ptsdrv_inwakeup(struct tty *tp)
625 {
626 struct pts_softc *psc = tty_softc(tp);
627
628 cv_broadcast(&psc->pts_inwait);
629 selwakeup(&psc->pts_inpoll);
630 KNOTE_LOCKED(&psc->pts_inpoll.si_note, 0);
631 }
632
633 static int
ptsdrv_open(struct tty * tp)634 ptsdrv_open(struct tty *tp)
635 {
636 struct pts_softc *psc = tty_softc(tp);
637
638 psc->pts_flags &= ~PTS_FINISHED;
639
640 return (0);
641 }
642
643 static void
ptsdrv_close(struct tty * tp)644 ptsdrv_close(struct tty *tp)
645 {
646 struct pts_softc *psc = tty_softc(tp);
647
648 /* Wake up any blocked readers/writers. */
649 psc->pts_flags |= PTS_FINISHED;
650 ptsdrv_outwakeup(tp);
651 ptsdrv_inwakeup(tp);
652 }
653
654 static void
ptsdrv_pktnotify(struct tty * tp,char event)655 ptsdrv_pktnotify(struct tty *tp, char event)
656 {
657 struct pts_softc *psc = tty_softc(tp);
658
659 /*
660 * Clear conflicting flags.
661 */
662
663 switch (event) {
664 case TIOCPKT_STOP:
665 psc->pts_pkt &= ~TIOCPKT_START;
666 break;
667 case TIOCPKT_START:
668 psc->pts_pkt &= ~TIOCPKT_STOP;
669 break;
670 case TIOCPKT_NOSTOP:
671 psc->pts_pkt &= ~TIOCPKT_DOSTOP;
672 break;
673 case TIOCPKT_DOSTOP:
674 psc->pts_pkt &= ~TIOCPKT_NOSTOP;
675 break;
676 }
677
678 psc->pts_pkt |= event;
679 ptsdrv_outwakeup(tp);
680 }
681
682 static void
ptsdrv_free(void * softc)683 ptsdrv_free(void *softc)
684 {
685 struct pts_softc *psc = softc;
686
687 /* Make device number available again. */
688 if (psc->pts_unit >= 0)
689 free_unr(pts_pool, psc->pts_unit);
690
691 chgptscnt(psc->pts_cred->cr_ruidinfo, -1, 0);
692 racct_sub_cred(psc->pts_cred, RACCT_NPTS, 1);
693 crfree(psc->pts_cred);
694
695 seldrain(&psc->pts_inpoll);
696 seldrain(&psc->pts_outpoll);
697 knlist_destroy(&psc->pts_inpoll.si_note);
698 knlist_destroy(&psc->pts_outpoll.si_note);
699
700 #ifdef PTS_EXTERNAL
701 /* Destroy master device as well. */
702 if (psc->pts_cdev != NULL)
703 destroy_dev_sched(psc->pts_cdev);
704 #endif /* PTS_EXTERNAL */
705
706 free(psc, M_PTS);
707 }
708
709 static struct ttydevsw pts_class = {
710 .tsw_flags = TF_NOPREFIX,
711 .tsw_outwakeup = ptsdrv_outwakeup,
712 .tsw_inwakeup = ptsdrv_inwakeup,
713 .tsw_open = ptsdrv_open,
714 .tsw_close = ptsdrv_close,
715 .tsw_pktnotify = ptsdrv_pktnotify,
716 .tsw_free = ptsdrv_free,
717 };
718
719 #ifndef PTS_EXTERNAL
720 static
721 #endif /* !PTS_EXTERNAL */
722 int
pts_alloc(int fflags,struct thread * td,struct file * fp)723 pts_alloc(int fflags, struct thread *td, struct file *fp)
724 {
725 int unit, ok, error;
726 struct tty *tp;
727 struct pts_softc *psc;
728 struct proc *p = td->td_proc;
729 struct ucred *cred = td->td_ucred;
730
731 /* Resource limiting. */
732 PROC_LOCK(p);
733 error = racct_add(p, RACCT_NPTS, 1);
734 if (error != 0) {
735 PROC_UNLOCK(p);
736 return (EAGAIN);
737 }
738 ok = chgptscnt(cred->cr_ruidinfo, 1, lim_cur(p, RLIMIT_NPTS));
739 if (!ok) {
740 racct_sub(p, RACCT_NPTS, 1);
741 PROC_UNLOCK(p);
742 return (EAGAIN);
743 }
744 PROC_UNLOCK(p);
745
746 /* Try to allocate a new pts unit number. */
747 unit = alloc_unr(pts_pool);
748 if (unit < 0) {
749 racct_sub(p, RACCT_NPTS, 1);
750 chgptscnt(cred->cr_ruidinfo, -1, 0);
751 return (EAGAIN);
752 }
753
754 /* Allocate TTY and softc. */
755 psc = malloc(sizeof(struct pts_softc), M_PTS, M_WAITOK|M_ZERO);
756 cv_init(&psc->pts_inwait, "ptsin");
757 cv_init(&psc->pts_outwait, "ptsout");
758
759 psc->pts_unit = unit;
760 psc->pts_cred = crhold(cred);
761
762 tp = tty_alloc(&pts_class, psc);
763 knlist_init_mtx(&psc->pts_inpoll.si_note, tp->t_mtx);
764 knlist_init_mtx(&psc->pts_outpoll.si_note, tp->t_mtx);
765
766 /* Expose the slave device as well. */
767 tty_makedev(tp, td->td_ucred, "pts/%u", psc->pts_unit);
768
769 finit(fp, fflags, DTYPE_PTS, tp, &ptsdev_ops);
770
771 return (0);
772 }
773
774 #ifdef PTS_EXTERNAL
775 int
pts_alloc_external(int fflags,struct thread * td,struct file * fp,struct cdev * dev,const char * name)776 pts_alloc_external(int fflags, struct thread *td, struct file *fp,
777 struct cdev *dev, const char *name)
778 {
779 int ok, error;
780 struct tty *tp;
781 struct pts_softc *psc;
782 struct proc *p = td->td_proc;
783 struct ucred *cred = td->td_ucred;
784
785 /* Resource limiting. */
786 PROC_LOCK(p);
787 error = racct_add(p, RACCT_NPTS, 1);
788 if (error != 0) {
789 PROC_UNLOCK(p);
790 return (EAGAIN);
791 }
792 ok = chgptscnt(cred->cr_ruidinfo, 1, lim_cur(p, RLIMIT_NPTS));
793 if (!ok) {
794 racct_sub(p, RACCT_NPTS, 1);
795 PROC_UNLOCK(p);
796 return (EAGAIN);
797 }
798 PROC_UNLOCK(p);
799
800 /* Allocate TTY and softc. */
801 psc = malloc(sizeof(struct pts_softc), M_PTS, M_WAITOK|M_ZERO);
802 cv_init(&psc->pts_inwait, "ptsin");
803 cv_init(&psc->pts_outwait, "ptsout");
804
805 psc->pts_unit = -1;
806 psc->pts_cdev = dev;
807 psc->pts_cred = crhold(cred);
808
809 tp = tty_alloc(&pts_class, psc);
810 knlist_init_mtx(&psc->pts_inpoll.si_note, tp->t_mtx);
811 knlist_init_mtx(&psc->pts_outpoll.si_note, tp->t_mtx);
812
813 /* Expose the slave device as well. */
814 tty_makedev(tp, td->td_ucred, "%s", name);
815
816 finit(fp, fflags, DTYPE_PTS, tp, &ptsdev_ops);
817
818 return (0);
819 }
820 #endif /* PTS_EXTERNAL */
821
822 int
sys_posix_openpt(struct thread * td,struct posix_openpt_args * uap)823 sys_posix_openpt(struct thread *td, struct posix_openpt_args *uap)
824 {
825 int error, fd;
826 struct file *fp;
827
828 /*
829 * POSIX states it's unspecified when other flags are passed. We
830 * don't allow this.
831 */
832 if (uap->flags & ~(O_RDWR|O_NOCTTY|O_CLOEXEC))
833 return (EINVAL);
834
835 error = falloc(td, &fp, &fd, uap->flags);
836 if (error)
837 return (error);
838
839 /* Allocate the actual pseudo-TTY. */
840 error = pts_alloc(FFLAGS(uap->flags & O_ACCMODE), td, fp);
841 if (error != 0) {
842 fdclose(td->td_proc->p_fd, fp, fd, td);
843 fdrop(fp, td);
844 return (error);
845 }
846
847 /* Pass it back to userspace. */
848 td->td_retval[0] = fd;
849 fdrop(fp, td);
850
851 return (0);
852 }
853
854 static void
pts_init(void * unused)855 pts_init(void *unused)
856 {
857
858 pts_pool = new_unrhdr(0, INT_MAX, NULL);
859 }
860
861 SYSINIT(pts, SI_SUB_DRIVERS, SI_ORDER_MIDDLE, pts_init, NULL);
862