1/*
2 * Copyright (c) 1982, 1986, 1989, 1993
3 * The Regents of the University of California. 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 * $FreeBSD: head/sys/dev/nmdm/nmdm.c 111119 2003-02-19 05:47:46Z imp $
34 */
35
36/*
37 * Pseudo-nulmodem driver
38 * Mighty handy for use with serial console in Vmware
39 */
40
41#include "opt_compat.h"
42#include <sys/param.h>
43#include <sys/systm.h>
44#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
45#include <sys/ioctl_compat.h>
46#endif
47#include <sys/proc.h>
48#include <sys/tty.h>
49#include <sys/conf.h>
50#include <sys/fcntl.h>
51#include <sys/poll.h>
52#include <sys/kernel.h>
53#include <sys/vnode.h>
54#include <sys/signalvar.h>
55#include <sys/malloc.h>
56
57MALLOC_DEFINE(M_NLMDM, "nullmodem", "nullmodem data structures");
58
59static void nmdmstart(struct tty *tp);
60static void nmdmstop(struct tty *tp, int rw);
61static void wakeup_other(struct tty *tp, int flag);
62static void nmdminit(int);
63static int nmdmshutdown(void);
64
65static d_open_t nmdmopen;
66static d_close_t nmdmclose;
67static d_read_t nmdmread;
68static d_write_t nmdmwrite;
69static d_ioctl_t nmdmioctl;
70
71#define CDEV_MAJOR 18
72static struct cdevsw nmdm_cdevsw = {
73 /* open */ nmdmopen,
74 /* close */ nmdmclose,
75 /* read */ nmdmread,
76 /* write */ nmdmwrite,
77 /* ioctl */ nmdmioctl,
78 /* poll */ ttypoll,
79 /* mmap */ nommap,
80 /* strategy */ nostrategy,
81 /* name */ "pts",
82 /* maj */ CDEV_MAJOR,
83 /* dump */ nodump,
84 /* psize */ nopsize,
85 /* flags */ D_TTY,
86};
87
88#define BUFSIZ 100 /* Chunk size iomoved to/from user */
89#define NMDM_MAX_NUM 128 /* Artificially limit # devices. */
90#define PF_STOPPED 0x10 /* user told stopped */
91
92struct softpart {
93 struct tty nm_tty;
94 dev_t dev;
95 int modemsignals; /* bits defined in sys/ttycom.h */
96 int gotbreak;
97};
98
99struct nm_softc {
100 int pt_flags;
101 struct softpart part1, part2;
102 struct prison *pt_prison;
103};
104
105static void
106nmdm_crossover(struct nm_softc *pti,
107 struct softpart *ourpart,
108 struct softpart *otherpart);
109
110#define GETPARTS(tp, ourpart, otherpart) \
111do { \
112 struct nm_softc *pti = tp->t_dev->si_drv1; \
113 if (tp == &pti->part1.nm_tty) { \
114 ourpart = &pti->part1; \
115 otherpart = &pti->part2; \
116 } else { \
117 ourpart = &pti->part2; \
118 otherpart = &pti->part1; \
119 } \
120} while (0)
121
122/*
123 * This function creates and initializes a pair of ttys.
124 */
125static void
126nmdminit(n)
127 int n;
128{
129 dev_t dev1, dev2;
130 struct nm_softc *pt;
131
132 /* For now we only map the lower 8 bits of the minor */
133 if (n & ~0xff)
134 return;
135
136 pt = malloc(sizeof(*pt), M_NLMDM, M_WAITOK);
137 bzero(pt, sizeof(*pt));
138 pt->part1.dev = dev1 = make_dev(&nmdm_cdevsw, n+n,
139 0, 0, 0666, "nmdm%dA", n);
140 pt->part2.dev = dev2 = make_dev(&nmdm_cdevsw, n+n+1,
141 0, 0, 0666, "nmdm%dB", n);
142
143 dev1->si_drv1 = dev2->si_drv1 = pt;
144 dev1->si_tty = &pt->part1.nm_tty;
145 dev2->si_tty = &pt->part2.nm_tty;
146 ttyregister(&pt->part1.nm_tty);
147 ttyregister(&pt->part2.nm_tty);
148 pt->part1.nm_tty.t_oproc = nmdmstart;
149 pt->part2.nm_tty.t_oproc = nmdmstart;
150 pt->part1.nm_tty.t_stop = nmdmstop;
151 pt->part2.nm_tty.t_dev = dev1;
152 pt->part1.nm_tty.t_dev = dev2;
153 pt->part2.nm_tty.t_stop = nmdmstop;
154}
155
156/*
157 * Device opened from userland
158 */
159static int
160nmdmopen(dev_t dev, int flag, int devtype, struct thread *td)
161{
162 register struct tty *tp, *tp2;
163 int error;
164 int minr;
165 dev_t nextdev;
166 struct nm_softc *pti;
167 int is_b;
168 int pair;
169 struct softpart *ourpart, *otherpart;
170
171 /*
172 * XXX: Gross hack for DEVFS:
173 * If we openned this device, ensure we have the
174 * next one too, so people can open it.
175 */
176 minr = dev2unit(dev);
177 pair = minr >> 1;
178 is_b = minr & 1;
179
180 if (pair < (NMDM_MAX_NUM - 1)) {
181 nextdev = makedev(major(dev), minr + 2);
182 if (!nextdev->si_drv1) {
183 nmdminit(pair + 1);
184 }
185 } else { /* Limit ourselves to 128 of them for now */
186 if (pair > (NMDM_MAX_NUM - 1))
187 return (ENXIO);
188 }
189 if (!dev->si_drv1)
190 nmdminit(pair);
191
192 if (!dev->si_drv1)
193 return(ENXIO);
194
195 pti = dev->si_drv1;
196 if (is_b)
197 tp = &pti->part2.nm_tty;
198 else
199 tp = &pti->part1.nm_tty;
200 GETPARTS(tp, ourpart, otherpart);
201
202 tp2 = &otherpart->nm_tty;
203 ourpart->modemsignals |= TIOCM_LE;
204
205 if ((tp->t_state & TS_ISOPEN) == 0) {
206 ttychars(tp); /* Set up default chars */
207 tp->t_iflag = TTYDEF_IFLAG;
208 tp->t_oflag = TTYDEF_OFLAG;
209 tp->t_lflag = TTYDEF_LFLAG;
210 tp->t_cflag = TTYDEF_CFLAG;
211 tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
212 } else if (tp->t_state & TS_XCLUDE && suser(td)) {
213 return (EBUSY);
214 } else if (pti->pt_prison != td->td_ucred->cr_prison) {
215 return (EBUSY);
216 }
217
218 /*
219 * If the other side is open we have carrier
220 */
221 if (tp2->t_state & TS_ISOPEN) {
222 (void)(*linesw[tp->t_line].l_modem)(tp, 1);
223 }
224
225 /*
226 * And the other side gets carrier as we are now open.
227 */
228 (void)(*linesw[tp2->t_line].l_modem)(tp2, 1);
229
230 /* External processing makes no sense here */
231 tp->t_lflag &= ~EXTPROC;
232
233 /*
234 * Wait here if we don't have carrier.
235 */
236#if 0
237 while ((tp->t_state & TS_CARR_ON) == 0) {
238 if (flag & FNONBLOCK)
239 break;
240 error = ttysleep(tp, TSA_CARR_ON(tp), TTIPRI | PCATCH,
241 "nmdopn", 0);
242 if (error)
243 return (error);
244 }
245#endif
246
247 /*
248 * Give the line disciplin a chance to set this end up.
249 */
250 error = (*linesw[tp->t_line].l_open)(dev, tp);
251
252 /*
253 * Wake up the other side.
254 * Theoretically not needed.
255 */
256 ourpart->modemsignals |= TIOCM_DTR;
257 nmdm_crossover(pti, ourpart, otherpart);
258 if (error == 0)
259 wakeup_other(tp, FREAD|FWRITE); /* XXX */
260 return (error);
261}
262
263/*
264 * Device closed again
265 */
266static int
267nmdmclose(dev_t dev, int flag, int mode, struct thread *td)
268{
269 register struct tty *tp, *tp2;
270 int err;
271 struct softpart *ourpart, *otherpart;
272
273 /*
274 * let the other end know that the game is up
275 */
276 tp = dev->si_tty;
277 GETPARTS(tp, ourpart, otherpart);
278 tp2 = &otherpart->nm_tty;
279 (void)(*linesw[tp2->t_line].l_modem)(tp2, 0);
280
281 /*
282 * XXX MDMBUF makes no sense for nmdms but would inhibit the above
283 * l_modem(). CLOCAL makes sense but isn't supported. Special
284 * l_modem()s that ignore carrier drop make no sense for nmdms but
285 * may be in use because other parts of the line discipline make
286 * sense for nmdms. Recover by doing everything that a normal
287 * ttymodem() would have done except for sending a SIGHUP.
288 */
289 if (tp2->t_state & TS_ISOPEN) {
290 tp2->t_state &= ~(TS_CARR_ON | TS_CONNECTED);
291 tp2->t_state |= TS_ZOMBIE;
292 ttyflush(tp2, FREAD | FWRITE);
293 }
294
295 err = (*linesw[tp->t_line].l_close)(tp, flag);
296 ourpart->modemsignals &= ~TIOCM_DTR;
297 nmdm_crossover(dev->si_drv1, ourpart, otherpart);
298 nmdmstop(tp, FREAD|FWRITE);
299 (void) ttyclose(tp);
300 return (err);
301}
302
303/*
304 * handle read(2) request from userland
305 */
306static int
307nmdmread(dev_t dev, struct uio *uio, int flag)
308{
309 int error = 0;
310 struct tty *tp, *tp2;
311 struct softpart *ourpart, *otherpart;
312
313 tp = dev->si_tty;
314 GETPARTS(tp, ourpart, otherpart);
315 tp2 = &otherpart->nm_tty;
316
317#if 0
318 if (tp2->t_state & TS_ISOPEN) {
319 error = (*linesw[tp->t_line].l_read)(tp, uio, flag);
320 wakeup_other(tp, FWRITE);
321 } else {
322 if (flag & IO_NDELAY) {
323 return (EWOULDBLOCK);
324 }
325 error = tsleep(TSA_PTC_READ(tp),
326 TTIPRI | PCATCH, "nmdout", 0);
327 }
328 }
329#else
330 if ((error = (*linesw[tp->t_line].l_read)(tp, uio, flag)) == 0)
331 wakeup_other(tp, FWRITE);
332#endif
333 return (error);
334}
335
336/*
337 * Write to pseudo-tty.
338 * Wakeups of controlling tty will happen
339 * indirectly, when tty driver calls nmdmstart.
340 */
341static int
342nmdmwrite(dev_t dev, struct uio *uio, int flag)
343{
344 register u_char *cp = 0;
345 register int cc = 0;
346 u_char locbuf[BUFSIZ];
347 int cnt = 0;
348 int error = 0;
349 struct tty *tp1, *tp;
350 struct softpart *ourpart, *otherpart;
351
352 tp1 = dev->si_tty;
353 /*
354 * Get the other tty struct.
355 * basically we are writing into the INPUT side of the other device.
356 */
357 GETPARTS(tp1, ourpart, otherpart);
358 tp = &otherpart->nm_tty;
359
360again:
361 if ((tp->t_state & TS_ISOPEN) == 0)
362 return (EIO);
363 while (uio->uio_resid > 0 || cc > 0) {
364 /*
365 * Fill up the buffer if it's empty
366 */
367 if (cc == 0) {
368 cc = min(uio->uio_resid, BUFSIZ);
369 cp = locbuf;
370 error = uiomove((caddr_t)cp, cc, uio);
371 if (error)
372 return (error);
373 /* check again for safety */
374 if ((tp->t_state & TS_ISOPEN) == 0) {
375 /* adjust for data copied in but not written */
376 uio->uio_resid += cc;
377 return (EIO);
378 }
379 }
380 while (cc > 0) {
381 if (((tp->t_rawq.c_cc + tp->t_canq.c_cc) >= (TTYHOG-2))
382 && ((tp->t_canq.c_cc > 0) || !(tp->t_iflag&ICANON))) {
383 /*
384 * Come here to wait for space in outq,
385 * or space in rawq, or an empty canq.
386 */
387 wakeup(TSA_HUP_OR_INPUT(tp));
388 if ((tp->t_state & TS_CONNECTED) == 0) {
389 /*
390 * Data piled up because not connected.
391 * Adjust for data copied in but
392 * not written.
393 */
394 uio->uio_resid += cc;
395 return (EIO);
396 }
397 if (flag & IO_NDELAY) {
398 /*
399 * Don't wait if asked not to.
400 * Adjust for data copied in but
401 * not written.
402 */
403 uio->uio_resid += cc;
404 if (cnt == 0)
405 return (EWOULDBLOCK);
406 return (0);
407 }
408 error = tsleep(TSA_PTC_WRITE(tp),
409 TTOPRI | PCATCH, "nmdout", 0);
410 if (error) {
411 /*
412 * Tsleep returned (signal?).
413 * Go find out what the user wants.
414 * adjust for data copied in but
415 * not written
416 */
417 uio->uio_resid += cc;
418 return (error);
419 }
420 goto again;
421 }
422 (*linesw[tp->t_line].l_rint)(*cp++, tp);
423 cnt++;
424 cc--;
425 }
426 cc = 0;
427 }
428 return (0);
429}
430
431/*
432 * Start output on pseudo-tty.
433 * Wake up process selecting or sleeping for input from controlling tty.
434 */
435static void
436nmdmstart(struct tty *tp)
437{
438 register struct nm_softc *pti = tp->t_dev->si_drv1;
439
440 if (tp->t_state & TS_TTSTOP)
441 return;
442 pti->pt_flags &= ~PF_STOPPED;
443 wakeup_other(tp, FREAD);
444}
445
446/* Wakes up the OTHER tty;*/
447static void
448wakeup_other(struct tty *tp, int flag)
449{
450 struct softpart *ourpart, *otherpart;
451
452 GETPARTS(tp, ourpart, otherpart);
453 if (flag & FREAD) {
454 selwakeup(&otherpart->nm_tty.t_rsel);
455 wakeup(TSA_PTC_READ((&otherpart->nm_tty)));
456 }
457 if (flag & FWRITE) {
458 selwakeup(&otherpart->nm_tty.t_wsel);
459 wakeup(TSA_PTC_WRITE((&otherpart->nm_tty)));
460 }
461}
462
463/*
464 * stopped output on tty, called when device is closed
465 */
466static void
467nmdmstop(register struct tty *tp, int flush)
468{
469 struct nm_softc *pti = tp->t_dev->si_drv1;
470 int flag;
471
472 /* note: FLUSHREAD and FLUSHWRITE already ok */
473 if (flush == 0) {
474 flush = TIOCPKT_STOP;
475 pti->pt_flags |= PF_STOPPED;
476 } else
477 pti->pt_flags &= ~PF_STOPPED;
478 /* change of perspective */
479 flag = 0;
480 if (flush & FREAD)
481 flag |= FWRITE;
482 if (flush & FWRITE)
483 flag |= FREAD;
484 wakeup_other(tp, flag);
485}
486
487/*
488 * handle ioctl(2) request from userland
489 */
490static int
491nmdmioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct thread *td)
492{
493 register struct tty *tp = dev->si_tty;
494 struct nm_softc *pti = dev->si_drv1;
495 int error, s;
496 register struct tty *tp2;
497 struct softpart *ourpart, *otherpart;
498
499 s = spltty();
500 GETPARTS(tp, ourpart, otherpart);
501 tp2 = &otherpart->nm_tty;
502
503 error = (*linesw[tp->t_line].l_ioctl)(tp, cmd, data, flag, td);
504 if (error == ENOIOCTL)
505 error = ttioctl(tp, cmd, data, flag);
506 if (error == ENOIOCTL) {
507 switch (cmd) {
508 case TIOCSBRK:
509 otherpart->gotbreak = 1;
510 break;
511 case TIOCCBRK:
512 break;
513 case TIOCSDTR:
514 ourpart->modemsignals |= TIOCM_DTR;
515 break;
516 case TIOCCDTR:
517 ourpart->modemsignals &= TIOCM_DTR;
518 break;
519 case TIOCMSET:
520 ourpart->modemsignals = *(int *)data;
521 otherpart->modemsignals = *(int *)data;
522 break;
523 case TIOCMBIS:
524 ourpart->modemsignals |= *(int *)data;
525 break;
526 case TIOCMBIC:
527 ourpart->modemsignals &= ~(*(int *)data);
528 otherpart->modemsignals &= ~(*(int *)data);
529 break;
530 case TIOCMGET:
531 *(int *)data = ourpart->modemsignals;
532 break;
533 case TIOCMSDTRWAIT:
534 break;
535 case TIOCMGDTRWAIT:
536 *(int *)data = 0;
537 break;
538 case TIOCTIMESTAMP:
539 /* FALLTHROUGH */
540 case TIOCDCDTIMESTAMP:
541 default:
542 splx(s);
543 error = ENOTTY;
544 return (error);
545 }
546 error = 0;
547 nmdm_crossover(pti, ourpart, otherpart);
548 }
549 splx(s);
550 return (error);
551}
552
553static void
554nmdm_crossover(struct nm_softc *pti, struct softpart *ourpart,
555 struct softpart *otherpart)
556{
557 otherpart->modemsignals &= ~(TIOCM_CTS|TIOCM_CAR);
558 if (ourpart->modemsignals & TIOCM_RTS)
559 otherpart->modemsignals |= TIOCM_CTS;
560 if (ourpart->modemsignals & TIOCM_DTR)
561 otherpart->modemsignals |= TIOCM_CAR;
562}
563
564/*
565 * Module handling
566 */
567static int
568nmdm_modevent(module_t mod, int type, void *data)
569{
570 int error = 0;
571
572 switch(type) {
573 case MOD_LOAD: /* start with 4 of them */
574 nmdminit(0);
575 nmdminit(1);
576 nmdminit(2);
577 nmdminit(3);
578 break;
579
580 case MOD_SHUTDOWN:
581 /* FALLTHROUGH */
582 case MOD_UNLOAD:
583 nmdmshutdown();
584 break;
585 default:
586 error = EOPNOTSUPP;
587 }
588 return (error);
589}
590
591/*
592 * Handle teardown of device
593 */
594static int
595nmdmshutdown(void)
596{
597 int i;
598 dev_t nextdev1;
599 dev_t nextdev2;
600 void * ptr1;
601
602 for(i = 0;( i < NMDM_MAX_NUM) ;i++) {
603 nextdev1 = makedev(CDEV_MAJOR, (i+i) );
604 nextdev2 = makedev(CDEV_MAJOR, (i+i) + 1);
605 ptr1 = nextdev1->si_drv1;
606 if (ptr1) {
607 revoke_and_destroy_dev(nextdev1);
608 revoke_and_destroy_dev(nextdev2);
609 free(ptr1, M_NLMDM);
610 } else {
611 freedev(nextdev1);
612 freedev(nextdev2);
613 }
614 }
615 return(0);
616}
617
618DEV_MODULE(nmdm, nmdm_modevent, NULL);