Fix a minor bug that prevented compilation.
[dragonfly.git] / sys / dev / misc / snp / snp.c
CommitLineData
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1/*
2 * Copyright (c) 1995 Ugen J.S.Antsilevich
3 *
4 * Redistribution and use in source forms, with and without modification,
5 * are permitted provided that this entire comment appears intact.
6 *
7 * Redistribution in binary form may occur without any restrictions.
8 * Obviously, it would be nice if you gave credit where credit is due
9 * but requiring it would be too onerous.
10 *
11 * This software is provided ``AS IS'' without any warranties of any kind.
12 *
13 * Snoop stuff.
14 *
15 * $FreeBSD: src/sys/dev/snp/snp.c,v 1.69.2.2 2002/05/06 07:30:02 dd Exp $
9ba76b73 16 * $DragonFly: src/sys/dev/misc/snp/snp.c,v 1.13 2006/06/13 08:12:02 dillon Exp $
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17 */
18
19#include <sys/param.h>
20#include <sys/systm.h>
21#include <sys/filio.h>
22#include <sys/malloc.h>
23#include <sys/tty.h>
24#include <sys/conf.h>
25#include <sys/poll.h>
26#include <sys/kernel.h>
27#include <sys/queue.h>
28#include <sys/snoop.h>
12cc2857 29#include <sys/thread2.h>
984263bc 30#include <sys/vnode.h>
f15db79e 31#include <sys/device.h>
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32
33static l_close_t snplclose;
34static l_write_t snplwrite;
35static d_open_t snpopen;
36static d_close_t snpclose;
37static d_read_t snpread;
38static d_write_t snpwrite;
39static d_ioctl_t snpioctl;
40static d_poll_t snppoll;
41
42#define CDEV_MAJOR 53
43static struct cdevsw snp_cdevsw = {
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44 /* name */ "snp",
45 /* maj */ CDEV_MAJOR,
46 /* flags */ 0,
47 /* port */ NULL,
455fcd7e 48 /* clone */ NULL,
fabb8ceb 49
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50 /* open */ snpopen,
51 /* close */ snpclose,
52 /* read */ snpread,
53 /* write */ snpwrite,
54 /* ioctl */ snpioctl,
55 /* poll */ snppoll,
56 /* mmap */ nommap,
57 /* strategy */ nostrategy,
984263bc 58 /* dump */ nodump,
fabb8ceb 59 /* psize */ nopsize
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60};
61
62static struct linesw snpdisc = {
63 ttyopen, snplclose, ttread, snplwrite,
64 l_nullioctl, ttyinput, ttstart, ttymodem
65};
66
67/*
68 * This is the main snoop per-device structure.
69 */
70struct snoop {
71 LIST_ENTRY(snoop) snp_list; /* List glue. */
72 dev_t snp_target; /* Target tty device. */
73 struct tty *snp_tty; /* Target tty pointer. */
74 u_long snp_len; /* Possible length. */
75 u_long snp_base; /* Data base. */
76 u_long snp_blen; /* Used length. */
77 caddr_t snp_buf; /* Allocation pointer. */
78 int snp_flags; /* Flags. */
79 struct selinfo snp_sel; /* Select info. */
80 int snp_olddisc; /* Old line discipline. */
81};
82
83/*
84 * Possible flags.
85 */
86#define SNOOP_ASYNC 0x0002
87#define SNOOP_OPEN 0x0004
88#define SNOOP_RWAIT 0x0008
89#define SNOOP_OFLOW 0x0010
90#define SNOOP_DOWN 0x0020
91
92/*
93 * Other constants.
94 */
95#define SNOOP_MINLEN (4*1024) /* This should be power of 2.
96 * 4K tested to be the minimum
97 * for which on normal tty
98 * usage there is no need to
99 * allocate more.
100 */
101#define SNOOP_MAXLEN (64*1024) /* This one also,64K enough
102 * If we grow more,something
103 * really bad in this world..
104 */
105
106static MALLOC_DEFINE(M_SNP, "snp", "Snoop device data");
107/*
108 * The number of the "snoop" line discipline. This gets determined at
109 * module load time.
110 */
111static int snooplinedisc;
112
113
114static LIST_HEAD(, snoop) snp_sclist = LIST_HEAD_INITIALIZER(&snp_sclist);
115
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116static struct tty *snpdevtotty (dev_t dev);
117static int snp_detach (struct snoop *snp);
118static int snp_down (struct snoop *snp);
119static int snp_in (struct snoop *snp, char *buf, int n);
120static int snp_modevent (module_t mod, int what, void *arg);
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121
122static int
c436375a 123snplclose(struct tty *tp, int flag)
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124{
125 struct snoop *snp;
126 int error;
127
128 snp = tp->t_sc;
129 error = snp_down(snp);
130 if (error != 0)
131 return (error);
132 error = ttylclose(tp, flag);
133 return (error);
134}
135
136static int
c436375a 137snplwrite(struct tty *tp, struct uio *uio, int flag)
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138{
139 struct iovec iov;
140 struct uio uio2;
141 struct snoop *snp;
142 int error, ilen;
143 char *ibuf;
144
145 error = 0;
146 ibuf = NULL;
147 snp = tp->t_sc;
148 while (uio->uio_resid > 0) {
149 ilen = imin(512, uio->uio_resid);
150 ibuf = malloc(ilen, M_SNP, M_WAITOK);
151 error = uiomove(ibuf, ilen, uio);
152 if (error != 0)
153 break;
154 snp_in(snp, ibuf, ilen);
155 /* Hackish, but probably the least of all evils. */
156 iov.iov_base = ibuf;
157 iov.iov_len = ilen;
158 uio2.uio_iov = &iov;
159 uio2.uio_iovcnt = 1;
160 uio2.uio_offset = 0;
161 uio2.uio_resid = ilen;
162 uio2.uio_segflg = UIO_SYSSPACE;
163 uio2.uio_rw = UIO_WRITE;
dadab5e9 164 uio2.uio_td = uio->uio_td;
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165 error = ttwrite(tp, &uio2, flag);
166 if (error != 0)
167 break;
168 free(ibuf, M_SNP);
169 ibuf = NULL;
170 }
171 if (ibuf != NULL)
172 free(ibuf, M_SNP);
173 return (error);
174}
175
176static struct tty *
c436375a 177snpdevtotty(dev_t dev)
984263bc 178{
f15db79e 179 if ((dev_dflags(dev) & D_TTY) == 0)
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180 return (NULL);
181 return (dev->si_tty);
182}
183
184#define SNP_INPUT_BUF 5 /* This is even too much, the maximal
185 * interactive mode write is 3 bytes
186 * length for function keys...
187 */
188
189static int
c436375a 190snpwrite(dev_t dev, struct uio *uio, int flag)
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191{
192 struct snoop *snp;
193 struct tty *tp;
194 int error, i, len;
195 unsigned char c[SNP_INPUT_BUF];
196
197 snp = dev->si_drv1;
198 tp = snp->snp_tty;
199 if (tp == NULL)
200 return (EIO);
201 if ((tp->t_sc == snp) && (tp->t_state & TS_SNOOP) &&
202 tp->t_line == snooplinedisc)
203 goto tty_input;
204
205 printf("Snoop: attempt to write to bad tty.\n");
206 return (EIO);
207
208tty_input:
209 if (!(tp->t_state & TS_ISOPEN))
210 return (EIO);
211
212 while (uio->uio_resid > 0) {
213 len = imin(uio->uio_resid, SNP_INPUT_BUF);
214 if ((error = uiomove(c, len, uio)) != 0)
215 return (error);
216 for (i=0; i < len; i++) {
217 if (ttyinput(c[i], tp))
218 return (EIO);
219 }
220 }
221 return (0);
222}
223
224
225static int
c436375a 226snpread(dev_t dev, struct uio *uio, int flag)
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227{
228 struct snoop *snp;
12cc2857 229 int error, len, n, nblen;
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230 caddr_t from;
231 char *nbuf;
232
233 snp = dev->si_drv1;
234 KASSERT(snp->snp_len + snp->snp_base <= snp->snp_blen,
235 ("snoop buffer error"));
236
237 if (snp->snp_tty == NULL)
238 return (EIO);
239
240 snp->snp_flags &= ~SNOOP_RWAIT;
241
242 do {
243 if (snp->snp_len == 0) {
244 if (flag & IO_NDELAY)
245 return (EWOULDBLOCK);
246 snp->snp_flags |= SNOOP_RWAIT;
377d4740 247 error = tsleep((caddr_t)snp, PCATCH, "snprd", 0);
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248 if (error != 0)
249 return (error);
250 }
251 } while (snp->snp_len == 0);
252
253 n = snp->snp_len;
254
255 error = 0;
256 while (snp->snp_len > 0 && uio->uio_resid > 0 && error == 0) {
257 len = min((unsigned)uio->uio_resid, snp->snp_len);
258 from = (caddr_t)(snp->snp_buf + snp->snp_base);
259 if (len == 0)
260 break;
261
262 error = uiomove(from, len, uio);
263 snp->snp_base += len;
264 snp->snp_len -= len;
265 }
266 if ((snp->snp_flags & SNOOP_OFLOW) && (n < snp->snp_len)) {
267 snp->snp_flags &= ~SNOOP_OFLOW;
268 }
12cc2857 269 crit_enter();
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270 nblen = snp->snp_blen;
271 if (((nblen / 2) >= SNOOP_MINLEN) && (nblen / 2) >= snp->snp_len) {
272 while (nblen / 2 >= snp->snp_len && nblen / 2 >= SNOOP_MINLEN)
273 nblen = nblen / 2;
274 if ((nbuf = malloc(nblen, M_SNP, M_NOWAIT)) != NULL) {
275 bcopy(snp->snp_buf + snp->snp_base, nbuf, snp->snp_len);
276 free(snp->snp_buf, M_SNP);
277 snp->snp_buf = nbuf;
278 snp->snp_blen = nblen;
279 snp->snp_base = 0;
280 }
281 }
12cc2857 282 crit_exit();
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283
284 return (error);
285}
286
287static int
c436375a 288snp_in(struct snoop *snp, char *buf, int n)
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289{
290 int s_free, s_tail;
12cc2857 291 int len, nblen;
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292 caddr_t from, to;
293 char *nbuf;
294
295 KASSERT(n >= 0, ("negative snoop char count"));
296
297 if (n == 0)
298 return (0);
299
300 if (snp->snp_flags & SNOOP_DOWN) {
301 printf("Snoop: more data to down interface.\n");
302 return (0);
303 }
304
305 if (snp->snp_flags & SNOOP_OFLOW) {
306 printf("Snoop: buffer overflow.\n");
307 /*
308 * On overflow we just repeat the standart close
309 * procedure...yes , this is waste of space but.. Then next
310 * read from device will fail if one would recall he is
311 * snooping and retry...
312 */
313
314 return (snp_down(snp));
315 }
316 s_tail = snp->snp_blen - (snp->snp_len + snp->snp_base);
317 s_free = snp->snp_blen - snp->snp_len;
318
319
320 if (n > s_free) {
12cc2857 321 crit_enter();
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322 nblen = snp->snp_blen;
323 while ((n > s_free) && ((nblen * 2) <= SNOOP_MAXLEN)) {
324 nblen = snp->snp_blen * 2;
325 s_free = nblen - (snp->snp_len + snp->snp_base);
326 }
327 if ((n <= s_free) && (nbuf = malloc(nblen, M_SNP, M_NOWAIT))) {
328 bcopy(snp->snp_buf + snp->snp_base, nbuf, snp->snp_len);
329 free(snp->snp_buf, M_SNP);
330 snp->snp_buf = nbuf;
331 snp->snp_blen = nblen;
332 snp->snp_base = 0;
333 } else {
334 snp->snp_flags |= SNOOP_OFLOW;
335 if (snp->snp_flags & SNOOP_RWAIT) {
336 snp->snp_flags &= ~SNOOP_RWAIT;
337 wakeup((caddr_t)snp);
338 }
12cc2857 339 crit_exit();
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340 return (0);
341 }
12cc2857 342 crit_exit();
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343 }
344 if (n > s_tail) {
345 from = (caddr_t)(snp->snp_buf + snp->snp_base);
346 to = (caddr_t)(snp->snp_buf);
347 len = snp->snp_len;
348 bcopy(from, to, len);
349 snp->snp_base = 0;
350 }
351 to = (caddr_t)(snp->snp_buf + snp->snp_base + snp->snp_len);
352 bcopy(buf, to, n);
353 snp->snp_len += n;
354
355 if (snp->snp_flags & SNOOP_RWAIT) {
356 snp->snp_flags &= ~SNOOP_RWAIT;
357 wakeup((caddr_t)snp);
358 }
359 selwakeup(&snp->snp_sel);
360 snp->snp_sel.si_pid = 0;
361
362 return (n);
363}
364
365static int
41c20dac 366snpopen(dev_t dev, int flag, int mode, d_thread_t *td)
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367{
368 struct snoop *snp;
369
370 if (dev->si_drv1 == NULL) {
371 make_dev(&snp_cdevsw, minor(dev), UID_ROOT, GID_WHEEL,
372 0600, "snp%d", minor(dev));
373 dev->si_drv1 = snp = malloc(sizeof(*snp), M_SNP,
374 M_WAITOK | M_ZERO);
e4c9c0c8 375 } else {
984263bc 376 return (EBUSY);
e4c9c0c8 377 }
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378
379 /*
380 * We intentionally do not OR flags with SNOOP_OPEN, but set them so
381 * all previous settings (especially SNOOP_OFLOW) will be cleared.
382 */
383 snp->snp_flags = SNOOP_OPEN;
384
385 snp->snp_buf = malloc(SNOOP_MINLEN, M_SNP, M_WAITOK);
386 snp->snp_blen = SNOOP_MINLEN;
387 snp->snp_base = 0;
388 snp->snp_len = 0;
389
390 /*
391 * snp_tty == NULL is for inactive snoop devices.
392 */
393 snp->snp_tty = NULL;
394 snp->snp_target = NODEV;
395
396 LIST_INSERT_HEAD(&snp_sclist, snp, snp_list);
397 return (0);
398}
399
400
401static int
c436375a 402snp_detach(struct snoop *snp)
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403{
404 struct tty *tp;
405
406 snp->snp_base = 0;
407 snp->snp_len = 0;
408
409 /*
410 * If line disc. changed we do not touch this pointer, SLIP/PPP will
411 * change it anyway.
412 */
413 tp = snp->snp_tty;
414 if (tp == NULL)
415 goto detach_notty;
416
417 if (tp && (tp->t_sc == snp) && (tp->t_state & TS_SNOOP) &&
418 tp->t_line == snooplinedisc) {
419 tp->t_sc = NULL;
420 tp->t_state &= ~TS_SNOOP;
421 tp->t_line = snp->snp_olddisc;
422 } else
423 printf("Snoop: bad attached tty data.\n");
424
425 snp->snp_tty = NULL;
426 snp->snp_target = NODEV;
427
428detach_notty:
429 selwakeup(&snp->snp_sel);
430 snp->snp_sel.si_pid = 0;
431 if ((snp->snp_flags & SNOOP_OPEN) == 0)
432 free(snp, M_SNP);
433
434 return (0);
435}
436
437static int
41c20dac 438snpclose(dev_t dev, int flags, int fmt, d_thread_t *td)
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439{
440 struct snoop *snp;
441
442 snp = dev->si_drv1;
443 snp->snp_blen = 0;
444 LIST_REMOVE(snp, snp_list);
445 free(snp->snp_buf, M_SNP);
446 snp->snp_flags &= ~SNOOP_OPEN;
447 dev->si_drv1 = NULL;
448
449 return (snp_detach(snp));
450}
451
452static int
c436375a 453snp_down(struct snoop *snp)
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454{
455
456 if (snp->snp_blen != SNOOP_MINLEN) {
457 free(snp->snp_buf, M_SNP);
458 snp->snp_buf = malloc(SNOOP_MINLEN, M_SNP, M_WAITOK);
459 snp->snp_blen = SNOOP_MINLEN;
460 }
461 snp->snp_flags |= SNOOP_DOWN;
462
463 return (snp_detach(snp));
464}
465
466static int
41c20dac 467snpioctl(dev_t dev, u_long cmd, caddr_t data, int flags, d_thread_t *td)
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468{
469 struct snoop *snp;
470 struct tty *tp, *tpo;
471 dev_t tdev;
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472
473 snp = dev->si_drv1;
474 switch (cmd) {
475 case SNPSTTY:
476 tdev = udev2dev(*((udev_t *)data), 0);
477 if (tdev == NODEV)
478 return (snp_down(snp));
479
480 tp = snpdevtotty(tdev);
481 if (!tp)
482 return (EINVAL);
483 if (tp->t_state & TS_SNOOP)
484 return (EBUSY);
485
12cc2857 486 crit_enter();
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487
488 if (snp->snp_target == NODEV) {
489 tpo = snp->snp_tty;
490 if (tpo)
491 tpo->t_state &= ~TS_SNOOP;
492 }
493
494 tp->t_sc = (caddr_t)snp;
495 tp->t_state |= TS_SNOOP;
496 snp->snp_olddisc = tp->t_line;
497 tp->t_line = snooplinedisc;
498 snp->snp_tty = tp;
499 snp->snp_target = tdev;
500
501 /*
502 * Clean overflow and down flags -
503 * we'll have a chance to get them in the future :)))
504 */
505 snp->snp_flags &= ~SNOOP_OFLOW;
506 snp->snp_flags &= ~SNOOP_DOWN;
12cc2857 507 crit_exit();
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508 break;
509
510 case SNPGTTY:
511 /*
512 * We keep snp_target field specially to make
513 * SNPGTTY happy, else we can't know what is device
514 * major/minor for tty.
515 */
516 *((dev_t *)data) = snp->snp_target;
517 break;
518
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519 case FIOASYNC:
520 if (*(int *)data)
521 snp->snp_flags |= SNOOP_ASYNC;
522 else
523 snp->snp_flags &= ~SNOOP_ASYNC;
524 break;
525
526 case FIONREAD:
12cc2857 527 crit_enter();
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528 if (snp->snp_tty != NULL)
529 *(int *)data = snp->snp_len;
530 else
531 if (snp->snp_flags & SNOOP_DOWN) {
532 if (snp->snp_flags & SNOOP_OFLOW)
533 *(int *)data = SNP_OFLOW;
534 else
535 *(int *)data = SNP_TTYCLOSE;
536 } else {
537 *(int *)data = SNP_DETACH;
538 }
12cc2857 539 crit_exit();
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540 break;
541
542 default:
543 return (ENOTTY);
544 }
545 return (0);
546}
547
548static int
41c20dac 549snppoll(dev_t dev, int events, d_thread_t *td)
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550{
551 struct snoop *snp;
552 int revents;
553
554 snp = dev->si_drv1;
555 revents = 0;
556 /*
557 * If snoop is down, we don't want to poll() forever so we return 1.
558 * Caller should see if we down via FIONREAD ioctl(). The last should
559 * return -1 to indicate down state.
560 */
561 if (events & (POLLIN | POLLRDNORM)) {
562 if (snp->snp_flags & SNOOP_DOWN || snp->snp_len > 0)
563 revents |= events & (POLLIN | POLLRDNORM);
564 else
41c20dac 565 selrecord(td, &snp->snp_sel);
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566 }
567 return (revents);
568}
569
570static int
c436375a 571snp_modevent(module_t mod, int type, void *data)
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572{
573
574 switch (type) {
575 case MOD_LOAD:
576 snooplinedisc = ldisc_register(LDISC_LOAD, &snpdisc);
e4c9c0c8 577 cdevsw_add(&snp_cdevsw, 0, 0);
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578 break;
579 case MOD_UNLOAD:
580 if (!LIST_EMPTY(&snp_sclist))
581 return (EBUSY);
582 ldisc_deregister(snooplinedisc);
e4c9c0c8 583 cdevsw_remove(&snp_cdevsw, 0, 0);
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584 break;
585 default:
586 break;
587 }
588 return (0);
589}
590
591static moduledata_t snp_mod = {
592 "snp",
593 snp_modevent,
594 NULL
595};
596DECLARE_MODULE(snp, snp_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE + CDEV_MAJOR);