2 * Copyright (c) 1995 Ugen J.S.Antsilevich
4 * Redistribution and use in source forms, with and without modification,
5 * are permitted provided that this entire comment appears intact.
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.
11 * This software is provided ``AS IS'' without any warranties of any kind.
15 * $FreeBSD: src/sys/dev/snp/snp.c,v 1.69.2.2 2002/05/06 07:30:02 dd Exp $
18 #include <sys/param.h>
19 #include <sys/systm.h>
20 #include <sys/filio.h>
21 #include <sys/malloc.h>
25 #include <sys/kernel.h>
26 #include <sys/queue.h>
27 #include <sys/snoop.h>
28 #include <sys/vnode.h>
30 static l_close_t snplclose;
31 static l_write_t snplwrite;
32 static d_open_t snpopen;
33 static d_close_t snpclose;
34 static d_read_t snpread;
35 static d_write_t snpwrite;
36 static d_ioctl_t snpioctl;
37 static d_poll_t snppoll;
40 static struct cdevsw snp_cdevsw = {
48 /* strategy */ nostrategy,
57 static struct linesw snpdisc = {
58 ttyopen, snplclose, ttread, snplwrite,
59 l_nullioctl, ttyinput, ttstart, ttymodem
63 * This is the main snoop per-device structure.
66 LIST_ENTRY(snoop) snp_list; /* List glue. */
67 dev_t snp_target; /* Target tty device. */
68 struct tty *snp_tty; /* Target tty pointer. */
69 u_long snp_len; /* Possible length. */
70 u_long snp_base; /* Data base. */
71 u_long snp_blen; /* Used length. */
72 caddr_t snp_buf; /* Allocation pointer. */
73 int snp_flags; /* Flags. */
74 struct selinfo snp_sel; /* Select info. */
75 int snp_olddisc; /* Old line discipline. */
81 #define SNOOP_ASYNC 0x0002
82 #define SNOOP_OPEN 0x0004
83 #define SNOOP_RWAIT 0x0008
84 #define SNOOP_OFLOW 0x0010
85 #define SNOOP_DOWN 0x0020
90 #define SNOOP_MINLEN (4*1024) /* This should be power of 2.
91 * 4K tested to be the minimum
92 * for which on normal tty
93 * usage there is no need to
96 #define SNOOP_MAXLEN (64*1024) /* This one also,64K enough
97 * If we grow more,something
98 * really bad in this world..
101 static MALLOC_DEFINE(M_SNP, "snp", "Snoop device data");
103 * The number of the "snoop" line discipline. This gets determined at
106 static int snooplinedisc;
109 static LIST_HEAD(, snoop) snp_sclist = LIST_HEAD_INITIALIZER(&snp_sclist);
111 static struct tty *snpdevtotty __P((dev_t dev));
112 static int snp_detach __P((struct snoop *snp));
113 static int snp_down __P((struct snoop *snp));
114 static int snp_in __P((struct snoop *snp, char *buf, int n));
115 static int snp_modevent __P((module_t mod, int what, void *arg));
126 error = snp_down(snp);
129 error = ttylclose(tp, flag);
134 snplwrite(tp, uio, flag)
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);
154 snp_in(snp, ibuf, ilen);
155 /* Hackish, but probably the least of all evils. */
161 uio2.uio_resid = ilen;
162 uio2.uio_segflg = UIO_SYSSPACE;
163 uio2.uio_rw = UIO_WRITE;
164 uio2.uio_procp = uio->uio_procp;
165 error = ttwrite(tp, &uio2, flag);
183 if (cdp == NULL || (cdp->d_flags & D_TTY) == 0)
185 return (dev->si_tty);
188 #define SNP_INPUT_BUF 5 /* This is even too much, the maximal
189 * interactive mode write is 3 bytes
190 * length for function keys...
194 snpwrite(dev, uio, flag)
202 unsigned char c[SNP_INPUT_BUF];
208 if ((tp->t_sc == snp) && (tp->t_state & TS_SNOOP) &&
209 tp->t_line == snooplinedisc)
212 printf("Snoop: attempt to write to bad tty.\n");
216 if (!(tp->t_state & TS_ISOPEN))
219 while (uio->uio_resid > 0) {
220 len = imin(uio->uio_resid, SNP_INPUT_BUF);
221 if ((error = uiomove(c, len, uio)) != 0)
223 for (i=0; i < len; i++) {
224 if (ttyinput(c[i], tp))
233 snpread(dev, uio, flag)
239 int error, len, n, nblen, s;
244 KASSERT(snp->snp_len + snp->snp_base <= snp->snp_blen,
245 ("snoop buffer error"));
247 if (snp->snp_tty == NULL)
250 snp->snp_flags &= ~SNOOP_RWAIT;
253 if (snp->snp_len == 0) {
254 if (flag & IO_NDELAY)
255 return (EWOULDBLOCK);
256 snp->snp_flags |= SNOOP_RWAIT;
257 error = tsleep((caddr_t)snp, (PZERO + 1) | PCATCH,
262 } while (snp->snp_len == 0);
267 while (snp->snp_len > 0 && uio->uio_resid > 0 && error == 0) {
268 len = min((unsigned)uio->uio_resid, snp->snp_len);
269 from = (caddr_t)(snp->snp_buf + snp->snp_base);
273 error = uiomove(from, len, uio);
274 snp->snp_base += len;
277 if ((snp->snp_flags & SNOOP_OFLOW) && (n < snp->snp_len)) {
278 snp->snp_flags &= ~SNOOP_OFLOW;
281 nblen = snp->snp_blen;
282 if (((nblen / 2) >= SNOOP_MINLEN) && (nblen / 2) >= snp->snp_len) {
283 while (nblen / 2 >= snp->snp_len && nblen / 2 >= SNOOP_MINLEN)
285 if ((nbuf = malloc(nblen, M_SNP, M_NOWAIT)) != NULL) {
286 bcopy(snp->snp_buf + snp->snp_base, nbuf, snp->snp_len);
287 free(snp->snp_buf, M_SNP);
289 snp->snp_blen = nblen;
309 KASSERT(n >= 0, ("negative snoop char count"));
314 if (snp->snp_flags & SNOOP_DOWN) {
315 printf("Snoop: more data to down interface.\n");
319 if (snp->snp_flags & SNOOP_OFLOW) {
320 printf("Snoop: buffer overflow.\n");
322 * On overflow we just repeat the standart close
323 * procedure...yes , this is waste of space but.. Then next
324 * read from device will fail if one would recall he is
325 * snooping and retry...
328 return (snp_down(snp));
330 s_tail = snp->snp_blen - (snp->snp_len + snp->snp_base);
331 s_free = snp->snp_blen - snp->snp_len;
336 nblen = snp->snp_blen;
337 while ((n > s_free) && ((nblen * 2) <= SNOOP_MAXLEN)) {
338 nblen = snp->snp_blen * 2;
339 s_free = nblen - (snp->snp_len + snp->snp_base);
341 if ((n <= s_free) && (nbuf = malloc(nblen, M_SNP, M_NOWAIT))) {
342 bcopy(snp->snp_buf + snp->snp_base, nbuf, snp->snp_len);
343 free(snp->snp_buf, M_SNP);
345 snp->snp_blen = nblen;
348 snp->snp_flags |= SNOOP_OFLOW;
349 if (snp->snp_flags & SNOOP_RWAIT) {
350 snp->snp_flags &= ~SNOOP_RWAIT;
351 wakeup((caddr_t)snp);
359 from = (caddr_t)(snp->snp_buf + snp->snp_base);
360 to = (caddr_t)(snp->snp_buf);
362 bcopy(from, to, len);
365 to = (caddr_t)(snp->snp_buf + snp->snp_base + snp->snp_len);
369 if (snp->snp_flags & SNOOP_RWAIT) {
370 snp->snp_flags &= ~SNOOP_RWAIT;
371 wakeup((caddr_t)snp);
373 selwakeup(&snp->snp_sel);
374 snp->snp_sel.si_pid = 0;
380 snpopen(dev, flag, mode, p)
387 if (dev->si_drv1 == NULL) {
388 make_dev(&snp_cdevsw, minor(dev), UID_ROOT, GID_WHEEL,
389 0600, "snp%d", minor(dev));
390 dev->si_drv1 = snp = malloc(sizeof(*snp), M_SNP,
396 * We intentionally do not OR flags with SNOOP_OPEN, but set them so
397 * all previous settings (especially SNOOP_OFLOW) will be cleared.
399 snp->snp_flags = SNOOP_OPEN;
401 snp->snp_buf = malloc(SNOOP_MINLEN, M_SNP, M_WAITOK);
402 snp->snp_blen = SNOOP_MINLEN;
407 * snp_tty == NULL is for inactive snoop devices.
410 snp->snp_target = NODEV;
412 LIST_INSERT_HEAD(&snp_sclist, snp, snp_list);
427 * If line disc. changed we do not touch this pointer, SLIP/PPP will
434 if (tp && (tp->t_sc == snp) && (tp->t_state & TS_SNOOP) &&
435 tp->t_line == snooplinedisc) {
437 tp->t_state &= ~TS_SNOOP;
438 tp->t_line = snp->snp_olddisc;
440 printf("Snoop: bad attached tty data.\n");
443 snp->snp_target = NODEV;
446 selwakeup(&snp->snp_sel);
447 snp->snp_sel.si_pid = 0;
448 if ((snp->snp_flags & SNOOP_OPEN) == 0)
455 snpclose(dev, flags, fmt, p)
465 LIST_REMOVE(snp, snp_list);
466 free(snp->snp_buf, M_SNP);
467 snp->snp_flags &= ~SNOOP_OPEN;
470 return (snp_detach(snp));
478 if (snp->snp_blen != SNOOP_MINLEN) {
479 free(snp->snp_buf, M_SNP);
480 snp->snp_buf = malloc(SNOOP_MINLEN, M_SNP, M_WAITOK);
481 snp->snp_blen = SNOOP_MINLEN;
483 snp->snp_flags |= SNOOP_DOWN;
485 return (snp_detach(snp));
489 snpioctl(dev, cmd, data, flags, p)
497 struct tty *tp, *tpo;
504 tdev = udev2dev(*((udev_t *)data), 0);
506 return (snp_down(snp));
508 tp = snpdevtotty(tdev);
511 if (tp->t_state & TS_SNOOP)
516 if (snp->snp_target == NODEV) {
519 tpo->t_state &= ~TS_SNOOP;
522 tp->t_sc = (caddr_t)snp;
523 tp->t_state |= TS_SNOOP;
524 snp->snp_olddisc = tp->t_line;
525 tp->t_line = snooplinedisc;
527 snp->snp_target = tdev;
530 * Clean overflow and down flags -
531 * we'll have a chance to get them in the future :)))
533 snp->snp_flags &= ~SNOOP_OFLOW;
534 snp->snp_flags &= ~SNOOP_DOWN;
540 * We keep snp_target field specially to make
541 * SNPGTTY happy, else we can't know what is device
542 * major/minor for tty.
544 *((dev_t *)data) = snp->snp_target;
552 snp->snp_flags |= SNOOP_ASYNC;
554 snp->snp_flags &= ~SNOOP_ASYNC;
559 if (snp->snp_tty != NULL)
560 *(int *)data = snp->snp_len;
562 if (snp->snp_flags & SNOOP_DOWN) {
563 if (snp->snp_flags & SNOOP_OFLOW)
564 *(int *)data = SNP_OFLOW;
566 *(int *)data = SNP_TTYCLOSE;
568 *(int *)data = SNP_DETACH;
580 snppoll(dev, events, p)
591 * If snoop is down, we don't want to poll() forever so we return 1.
592 * Caller should see if we down via FIONREAD ioctl(). The last should
593 * return -1 to indicate down state.
595 if (events & (POLLIN | POLLRDNORM)) {
596 if (snp->snp_flags & SNOOP_DOWN || snp->snp_len > 0)
597 revents |= events & (POLLIN | POLLRDNORM);
599 selrecord(p, &snp->snp_sel);
605 snp_modevent(mod, type, data)
613 snooplinedisc = ldisc_register(LDISC_LOAD, &snpdisc);
614 cdevsw_add(&snp_cdevsw);
617 if (!LIST_EMPTY(&snp_sclist))
619 ldisc_deregister(snooplinedisc);
620 cdevsw_remove(&snp_cdevsw);
628 static moduledata_t snp_mod = {
633 DECLARE_MODULE(snp, snp_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE + CDEV_MAJOR);