Optimize lwkt_rwlock.c a bit
[dragonfly.git] / sys / dev / misc / nmdm / nmdm.c
CommitLineData
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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: src/sys/dev/nmdm/nmdm.c,v 1.5.2.1 2001/08/11 00:54:14 mp Exp $
1de703da 34 * $DragonFly: src/sys/dev/misc/nmdm/nmdm.c,v 1.2 2003/06/17 04:28:28 dillon Exp $
984263bc
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35 */
36
37/*
38 * Pseudo-nulmodem Driver
39 */
40#include "opt_compat.h"
41#include <sys/param.h>
42#include <sys/systm.h>
43#if defined(COMPAT_43) || defined(COMPAT_SUNOS)
44#include <sys/ioctl_compat.h>
45#endif
46#include <sys/proc.h>
47#include <sys/tty.h>
48#include <sys/conf.h>
49#include <sys/fcntl.h>
50#include <sys/poll.h>
51#include <sys/kernel.h>
52#include <sys/vnode.h>
53#include <sys/signalvar.h>
54#include <sys/malloc.h>
55
56MALLOC_DEFINE(M_NLMDM, "nullmodem", "nullmodem data structures");
57
58static void nmdmstart __P((struct tty *tp));
59static void nmdmstop __P((struct tty *tp, int rw));
60static void wakeup_other __P((struct tty *tp, int flag));
61static void nmdminit __P((int n));
62
63static d_open_t nmdmopen;
64static d_close_t nmdmclose;
65static d_read_t nmdmread;
66static d_write_t nmdmwrite;
67static d_ioctl_t nmdmioctl;
68
69#define CDEV_MAJOR 18
70static struct cdevsw nmdm_cdevsw = {
71 /* open */ nmdmopen,
72 /* close */ nmdmclose,
73 /* read */ nmdmread,
74 /* write */ nmdmwrite,
75 /* ioctl */ nmdmioctl,
76 /* poll */ ttypoll,
77 /* mmap */ nommap,
78 /* strategy */ nostrategy,
79 /* name */ "pts",
80 /* maj */ CDEV_MAJOR,
81 /* dump */ nodump,
82 /* psize */ nopsize,
83 /* flags */ D_TTY,
84 /* bmaj */ -1
85};
86
87#define BUFSIZ 100 /* Chunk size iomoved to/from user */
88
89struct softpart {
90 struct tty nm_tty;
91 dev_t dev;
92 int modemsignals; /* bits defined in sys/ttycom.h */
93 int gotbreak;
94};
95
96struct nm_softc {
97 int pt_flags;
98 struct softpart part1, part2;
99 struct prison *pt_prison;
100};
101
102#define PF_STOPPED 0x10 /* user told stopped */
103
104static void
105nmdm_crossover(struct nm_softc *pti,
106 struct softpart *ourpart,
107 struct softpart *otherpart);
108
109#define GETPARTS(tp, ourpart, otherpart) \
110do { \
111 struct nm_softc *pti = tp->t_dev->si_drv1; \
112 if (tp == &pti->part1.nm_tty) { \
113 ourpart = &pti->part1; \
114 otherpart = &pti->part2; \
115 } else { \
116 ourpart = &pti->part2; \
117 otherpart = &pti->part1; \
118 } \
119} while (0)
120
121/*
122 * This function creates and initializes a pair of ttys.
123 */
124static void
125nmdminit(n)
126 int n;
127{
128 dev_t dev1, dev2;
129 struct nm_softc *pt;
130
131 /* For now we only map the lower 8 bits of the minor */
132 if (n & ~0xff)
133 return;
134
135 pt = malloc(sizeof(*pt), M_NLMDM, M_WAITOK);
136 bzero(pt, sizeof(*pt));
137 pt->part1.dev = dev1 = make_dev(&nmdm_cdevsw, n+n,
138 0, 0, 0666, "nmdm%dA", n);
139 pt->part2.dev = dev2 = make_dev(&nmdm_cdevsw, n+n+1,
140 0, 0, 0666, "nmdm%dB", n);
141
142 dev1->si_drv1 = dev2->si_drv1 = pt;
143 dev1->si_tty = &pt->part1.nm_tty;
144 dev2->si_tty = &pt->part2.nm_tty;
145 ttyregister(&pt->part1.nm_tty);
146 ttyregister(&pt->part2.nm_tty);
147 pt->part1.nm_tty.t_oproc = nmdmstart;
148 pt->part2.nm_tty.t_oproc = nmdmstart;
149 pt->part1.nm_tty.t_stop = nmdmstop;
150 pt->part2.nm_tty.t_dev = dev1;
151 pt->part1.nm_tty.t_dev = dev2;
152 pt->part2.nm_tty.t_stop = nmdmstop;
153}
154
155/*ARGSUSED*/
156static int
157nmdmopen(dev, flag, devtype, p)
158 dev_t dev;
159 int flag, devtype;
160 struct proc *p;
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 = lminor(dev);
177 pair = minr >> 1;
178 is_b = minr & 1;
179
180 if (pair < 127) {
181 nextdev = makedev(major(dev), (pair+pair) + 1);
182 if (!nextdev->si_drv1) {
183 nmdminit(pair + 1);
184 }
185 }
186 if (!dev->si_drv1)
187 nmdminit(pair);
188
189 if (!dev->si_drv1)
190 return(ENXIO);
191
192 pti = dev->si_drv1;
193 if (is_b)
194 tp = &pti->part2.nm_tty;
195 else
196 tp = &pti->part1.nm_tty;
197 GETPARTS(tp, ourpart, otherpart);
198 tp2 = &otherpart->nm_tty;
199 ourpart->modemsignals |= TIOCM_LE;
200
201 if ((tp->t_state & TS_ISOPEN) == 0) {
202 ttychars(tp); /* Set up default chars */
203 tp->t_iflag = TTYDEF_IFLAG;
204 tp->t_oflag = TTYDEF_OFLAG;
205 tp->t_lflag = TTYDEF_LFLAG;
206 tp->t_cflag = TTYDEF_CFLAG;
207 tp->t_ispeed = tp->t_ospeed = TTYDEF_SPEED;
208 } else if (tp->t_state & TS_XCLUDE && suser(p)) {
209 return (EBUSY);
210 } else if (pti->pt_prison != p->p_prison) {
211 return (EBUSY);
212 }
213
214 /*
215 * If the other side is open we have carrier
216 */
217 if (tp2->t_state & TS_ISOPEN) {
218 (void)(*linesw[tp->t_line].l_modem)(tp, 1);
219 }
220
221 /*
222 * And the other side gets carrier as we are now open.
223 */
224 (void)(*linesw[tp2->t_line].l_modem)(tp2, 1);
225
226 /* External processing makes no sense here */
227 tp->t_lflag &= ~EXTPROC;
228
229 /*
230 * Wait here if we don't have carrier.
231 */
232#if 0
233 while ((tp->t_state & TS_CARR_ON) == 0) {
234 if (flag & FNONBLOCK)
235 break;
236 error = ttysleep(tp, TSA_CARR_ON(tp), TTIPRI | PCATCH,
237 "nmdopn", 0);
238 if (error)
239 return (error);
240 }
241#endif
242
243 /*
244 * Give the line disciplin a chance to set this end up.
245 */
246 error = (*linesw[tp->t_line].l_open)(dev, tp);
247
248 /*
249 * Wake up the other side.
250 * Theoretically not needed.
251 */
252 ourpart->modemsignals |= TIOCM_DTR;
253 nmdm_crossover(pti, ourpart, otherpart);
254 if (error == 0)
255 wakeup_other(tp, FREAD|FWRITE); /* XXX */
256 return (error);
257}
258
259static int
260nmdmclose(dev, flag, mode, p)
261 dev_t dev;
262 int flag, mode;
263 struct proc *p;
264{
265 register struct tty *tp, *tp2;
266 int err;
267 struct softpart *ourpart, *otherpart;
268
269 /*
270 * let the other end know that the game is up
271 */
272 tp = dev->si_tty;
273 GETPARTS(tp, ourpart, otherpart);
274 tp2 = &otherpart->nm_tty;
275 (void)(*linesw[tp2->t_line].l_modem)(tp2, 0);
276
277 /*
278 * XXX MDMBUF makes no sense for nmdms but would inhibit the above
279 * l_modem(). CLOCAL makes sense but isn't supported. Special
280 * l_modem()s that ignore carrier drop make no sense for nmdms but
281 * may be in use because other parts of the line discipline make
282 * sense for nmdms. Recover by doing everything that a normal
283 * ttymodem() would have done except for sending a SIGHUP.
284 */
285 if (tp2->t_state & TS_ISOPEN) {
286 tp2->t_state &= ~(TS_CARR_ON | TS_CONNECTED);
287 tp2->t_state |= TS_ZOMBIE;
288 ttyflush(tp2, FREAD | FWRITE);
289 }
290
291 err = (*linesw[tp->t_line].l_close)(tp, flag);
292 ourpart->modemsignals &= ~TIOCM_DTR;
293 nmdm_crossover(dev->si_drv1, ourpart, otherpart);
294 nmdmstop(tp, FREAD|FWRITE);
295 (void) ttyclose(tp);
296 return (err);
297}
298
299static int
300nmdmread(dev, uio, flag)
301 dev_t dev;
302 struct uio *uio;
303 int flag;
304{
305 int error = 0;
306 struct tty *tp, *tp2;
307 struct softpart *ourpart, *otherpart;
308
309 tp = dev->si_tty;
310 GETPARTS(tp, ourpart, otherpart);
311 tp2 = &otherpart->nm_tty;
312
313#if 0
314 if (tp2->t_state & TS_ISOPEN) {
315 error = (*linesw[tp->t_line].l_read)(tp, uio, flag);
316 wakeup_other(tp, FWRITE);
317 } else {
318 if (flag & IO_NDELAY) {
319 return (EWOULDBLOCK);
320 }
321 error = tsleep(TSA_PTC_READ(tp),
322 TTIPRI | PCATCH, "nmdout", 0);
323 }
324 }
325#else
326 if ((error = (*linesw[tp->t_line].l_read)(tp, uio, flag)) == 0)
327 wakeup_other(tp, FWRITE);
328#endif
329 return (error);
330}
331
332/*
333 * Write to pseudo-tty.
334 * Wakeups of controlling tty will happen
335 * indirectly, when tty driver calls nmdmstart.
336 */
337static int
338nmdmwrite(dev, uio, flag)
339 dev_t dev;
340 struct uio *uio;
341 int flag;
342{
343 register u_char *cp = 0;
344 register int cc = 0;
345 u_char locbuf[BUFSIZ];
346 int cnt = 0;
347 int error = 0;
348 struct tty *tp1, *tp;
349 struct softpart *ourpart, *otherpart;
350
351 tp1 = dev->si_tty;
352 /*
353 * Get the other tty struct.
354 * basically we are writing into the INPUT side of the other device.
355 */
356 GETPARTS(tp1, ourpart, otherpart);
357 tp = &otherpart->nm_tty;
358
359again:
360 if ((tp->t_state & TS_ISOPEN) == 0)
361 return (EIO);
362 while (uio->uio_resid > 0 || cc > 0) {
363 /*
364 * Fill up the buffer if it's empty
365 */
366 if (cc == 0) {
367 cc = min(uio->uio_resid, BUFSIZ);
368 cp = locbuf;
369 error = uiomove((caddr_t)cp, cc, uio);
370 if (error)
371 return (error);
372 /* check again for safety */
373 if ((tp->t_state & TS_ISOPEN) == 0) {
374 /* adjust for data copied in but not written */
375 uio->uio_resid += cc;
376 return (EIO);
377 }
378 }
379 while (cc > 0) {
380 if (((tp->t_rawq.c_cc + tp->t_canq.c_cc) >= (TTYHOG-2))
381 && ((tp->t_canq.c_cc > 0) || !(tp->t_iflag&ICANON))) {
382 /*
383 * Come here to wait for space in outq,
384 * or space in rawq, or an empty canq.
385 */
386 wakeup(TSA_HUP_OR_INPUT(tp));
387 if ((tp->t_state & TS_CONNECTED) == 0) {
388 /*
389 * Data piled up because not connected.
390 * Adjust for data copied in but
391 * not written.
392 */
393 uio->uio_resid += cc;
394 return (EIO);
395 }
396 if (flag & IO_NDELAY) {
397 /*
398 * Don't wait if asked not to.
399 * Adjust for data copied in but
400 * not written.
401 */
402 uio->uio_resid += cc;
403 if (cnt == 0)
404 return (EWOULDBLOCK);
405 return (0);
406 }
407 error = tsleep(TSA_PTC_WRITE(tp),
408 TTOPRI | PCATCH, "nmdout", 0);
409 if (error) {
410 /*
411 * Tsleep returned (signal?).
412 * Go find out what the user wants.
413 * adjust for data copied in but
414 * not written
415 */
416 uio->uio_resid += cc;
417 return (error);
418 }
419 goto again;
420 }
421 (*linesw[tp->t_line].l_rint)(*cp++, tp);
422 cnt++;
423 cc--;
424 }
425 cc = 0;
426 }
427 return (0);
428}
429
430/*
431 * Start output on pseudo-tty.
432 * Wake up process selecting or sleeping for input from controlling tty.
433 */
434static void
435nmdmstart(tp)
436 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(tp, flag)
449 struct tty *tp;
450 int flag;
451{
452 struct softpart *ourpart, *otherpart;
453
454 GETPARTS(tp, ourpart, otherpart);
455 if (flag & FREAD) {
456 selwakeup(&otherpart->nm_tty.t_rsel);
457 wakeup(TSA_PTC_READ((&otherpart->nm_tty)));
458 }
459 if (flag & FWRITE) {
460 selwakeup(&otherpart->nm_tty.t_wsel);
461 wakeup(TSA_PTC_WRITE((&otherpart->nm_tty)));
462 }
463}
464
465static void
466nmdmstop(tp, flush)
467 register struct tty *tp;
468 int flush;
469{
470 struct nm_softc *pti = tp->t_dev->si_drv1;
471 int flag;
472
473 /* note: FLUSHREAD and FLUSHWRITE already ok */
474 if (flush == 0) {
475 flush = TIOCPKT_STOP;
476 pti->pt_flags |= PF_STOPPED;
477 } else
478 pti->pt_flags &= ~PF_STOPPED;
479 /* change of perspective */
480 flag = 0;
481 if (flush & FREAD)
482 flag |= FWRITE;
483 if (flush & FWRITE)
484 flag |= FREAD;
485 wakeup_other(tp, flag);
486}
487
488/*ARGSUSED*/
489static int
490nmdmioctl(dev, cmd, data, flag, p)
491 dev_t dev;
492 u_long cmd;
493 caddr_t data;
494 int flag;
495 struct proc *p;
496{
497 register struct tty *tp = dev->si_tty;
498 struct nm_softc *pti = dev->si_drv1;
499 int error, s;
500 register struct tty *tp2;
501 struct softpart *ourpart, *otherpart;
502
503 s = spltty();
504 GETPARTS(tp, ourpart, otherpart);
505 tp2 = &otherpart->nm_tty;
506
507 error = (*linesw[tp->t_line].l_ioctl)(tp, cmd, data, flag, p);
508 if (error == ENOIOCTL)
509 error = ttioctl(tp, cmd, data, flag);
510 if (error == ENOIOCTL) {
511 switch (cmd) {
512 case TIOCSBRK:
513 otherpart->gotbreak = 1;
514 break;
515 case TIOCCBRK:
516 break;
517 case TIOCSDTR:
518 ourpart->modemsignals |= TIOCM_DTR;
519 break;
520 case TIOCCDTR:
521 ourpart->modemsignals &= TIOCM_DTR;
522 break;
523 case TIOCMSET:
524 ourpart->modemsignals = *(int *)data;
525 otherpart->modemsignals = *(int *)data;
526 break;
527 case TIOCMBIS:
528 ourpart->modemsignals |= *(int *)data;
529 break;
530 case TIOCMBIC:
531 ourpart->modemsignals &= ~(*(int *)data);
532 otherpart->modemsignals &= ~(*(int *)data);
533 break;
534 case TIOCMGET:
535 *(int *)data = ourpart->modemsignals;
536 break;
537 case TIOCMSDTRWAIT:
538 break;
539 case TIOCMGDTRWAIT:
540 *(int *)data = 0;
541 break;
542 case TIOCTIMESTAMP:
543 case TIOCDCDTIMESTAMP:
544 default:
545 splx(s);
546 error = ENOTTY;
547 return (error);
548 }
549 error = 0;
550 nmdm_crossover(pti, ourpart, otherpart);
551 }
552 splx(s);
553 return (error);
554}
555
556static void
557nmdm_crossover(struct nm_softc *pti,
558 struct softpart *ourpart,
559 struct softpart *otherpart)
560{
561 otherpart->modemsignals &= ~(TIOCM_CTS|TIOCM_CAR);
562 if (ourpart->modemsignals & TIOCM_RTS)
563 otherpart->modemsignals |= TIOCM_CTS;
564 if (ourpart->modemsignals & TIOCM_DTR)
565 otherpart->modemsignals |= TIOCM_CAR;
566}
567
568
569
570static void nmdm_drvinit __P((void *unused));
571
572static void
573nmdm_drvinit(unused)
574 void *unused;
575{
576 cdevsw_add(&nmdm_cdevsw);
577 /* XXX: Gross hack for DEVFS */
578 nmdminit(0);
579}
580
581SYSINIT(nmdmdev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,nmdm_drvinit,NULL)