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.
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,
56 static struct linesw snpdisc = {
57 ttyopen, snplclose, ttread, snplwrite,
58 l_nullioctl, ttyinput, ttstart, ttymodem
62 * This is the main snoop per-device structure.
65 LIST_ENTRY(snoop) snp_list; /* List glue. */
66 int snp_unit; /* Device number. */
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;
107 static udev_t snpbasedev = NOUDEV;
110 static LIST_HEAD(, snoop) snp_sclist = LIST_HEAD_INITIALIZER(&snp_sclist);
112 static struct tty *snpdevtotty(dev_t dev);
113 static void snp_clone(void *arg, char *name,
114 int namelen, dev_t *dev);
115 static int snp_detach(struct snoop *snp);
116 static int snp_down(struct snoop *snp);
117 static int snp_in(struct snoop *snp, char *buf, int n);
118 static int snp_modevent(module_t mod, int what, void *arg);
129 error = snp_down(snp);
132 error = ttylclose(tp, flag);
137 snplwrite(tp, uio, flag)
151 while (uio->uio_resid > 0) {
152 ilen = imin(512, uio->uio_resid);
153 ibuf = malloc(ilen, M_SNP, M_WAITOK);
154 error = uiomove(ibuf, ilen, uio);
157 snp_in(snp, ibuf, ilen);
158 /* Hackish, but probably the least of all evils. */
164 uio2.uio_resid = ilen;
165 uio2.uio_segflg = UIO_SYSSPACE;
166 uio2.uio_rw = UIO_WRITE;
167 uio2.uio_td = uio->uio_td;
168 error = ttwrite(tp, &uio2, flag);
186 if (cdp == NULL || (cdp->d_flags & D_TTY) == 0)
188 return (dev->si_tty);
191 #define SNP_INPUT_BUF 5 /* This is even too much, the maximal
192 * interactive mode write is 3 bytes
193 * length for function keys...
197 snpwrite(dev, uio, flag)
205 unsigned char c[SNP_INPUT_BUF];
211 if ((tp->t_sc == snp) && (tp->t_state & TS_SNOOP) &&
212 tp->t_line == snooplinedisc)
215 printf("snp%d: attempt to write to bad tty\n", snp->snp_unit);
219 if (!(tp->t_state & TS_ISOPEN))
222 while (uio->uio_resid > 0) {
223 len = imin(uio->uio_resid, SNP_INPUT_BUF);
224 if ((error = uiomove(c, len, uio)) != 0)
226 for (i=0; i < len; i++) {
227 if (ttyinput(c[i], tp))
236 snpread(dev, uio, flag)
242 int error, len, n, nblen, s;
247 KASSERT(snp->snp_len + snp->snp_base <= snp->snp_blen,
248 ("snoop buffer error"));
250 if (snp->snp_tty == NULL)
253 snp->snp_flags &= ~SNOOP_RWAIT;
256 if (snp->snp_len == 0) {
257 if (flag & IO_NDELAY)
258 return (EWOULDBLOCK);
259 snp->snp_flags |= SNOOP_RWAIT;
260 error = tsleep((caddr_t)snp, (PZERO + 1) | PCATCH,
265 } while (snp->snp_len == 0);
270 while (snp->snp_len > 0 && uio->uio_resid > 0 && error == 0) {
271 len = min((unsigned)uio->uio_resid, snp->snp_len);
272 from = (caddr_t)(snp->snp_buf + snp->snp_base);
276 error = uiomove(from, len, uio);
277 snp->snp_base += len;
280 if ((snp->snp_flags & SNOOP_OFLOW) && (n < snp->snp_len)) {
281 snp->snp_flags &= ~SNOOP_OFLOW;
284 nblen = snp->snp_blen;
285 if (((nblen / 2) >= SNOOP_MINLEN) && (nblen / 2) >= snp->snp_len) {
286 while (nblen / 2 >= snp->snp_len && nblen / 2 >= SNOOP_MINLEN)
288 if ((nbuf = malloc(nblen, M_SNP, M_NOWAIT)) != NULL) {
289 bcopy(snp->snp_buf + snp->snp_base, nbuf, snp->snp_len);
290 free(snp->snp_buf, M_SNP);
292 snp->snp_blen = nblen;
312 KASSERT(n >= 0, ("negative snoop char count"));
317 if (snp->snp_flags & SNOOP_DOWN) {
318 printf("snp%d: more data to down interface\n", snp->snp_unit);
322 if (snp->snp_flags & SNOOP_OFLOW) {
323 printf("snp%d: buffer overflow\n", snp->snp_unit);
325 * On overflow we just repeat the standart close
326 * procedure...yes , this is waste of space but.. Then next
327 * read from device will fail if one would recall he is
328 * snooping and retry...
331 return (snp_down(snp));
333 s_tail = snp->snp_blen - (snp->snp_len + snp->snp_base);
334 s_free = snp->snp_blen - snp->snp_len;
339 nblen = snp->snp_blen;
340 while ((n > s_free) && ((nblen * 2) <= SNOOP_MAXLEN)) {
341 nblen = snp->snp_blen * 2;
342 s_free = nblen - (snp->snp_len + snp->snp_base);
344 if ((n <= s_free) && (nbuf = malloc(nblen, M_SNP, M_NOWAIT))) {
345 bcopy(snp->snp_buf + snp->snp_base, nbuf, snp->snp_len);
346 free(snp->snp_buf, M_SNP);
348 snp->snp_blen = nblen;
351 snp->snp_flags |= SNOOP_OFLOW;
352 if (snp->snp_flags & SNOOP_RWAIT) {
353 snp->snp_flags &= ~SNOOP_RWAIT;
354 wakeup((caddr_t)snp);
362 from = (caddr_t)(snp->snp_buf + snp->snp_base);
363 to = (caddr_t)(snp->snp_buf);
365 bcopy(from, to, len);
368 to = (caddr_t)(snp->snp_buf + snp->snp_base + snp->snp_len);
372 if (snp->snp_flags & SNOOP_RWAIT) {
373 snp->snp_flags &= ~SNOOP_RWAIT;
374 wakeup((caddr_t)snp);
376 selwakeup(&snp->snp_sel);
382 snpopen(dev, flag, mode, td)
389 if (dev->si_drv1 == NULL) {
390 if (!(dev->si_flags & SI_NAMED))
391 make_dev(&snp_cdevsw, minor(dev), UID_ROOT, GID_WHEEL,
392 0600, "snp%d", dev2unit(dev));
393 dev->si_drv1 = snp = malloc(sizeof(*snp), M_SNP,
395 snp->snp_unit = dev2unit(dev);
400 * We intentionally do not OR flags with SNOOP_OPEN, but set them so
401 * all previous settings (especially SNOOP_OFLOW) will be cleared.
403 snp->snp_flags = SNOOP_OPEN;
405 snp->snp_buf = malloc(SNOOP_MINLEN, M_SNP, M_WAITOK);
406 snp->snp_blen = SNOOP_MINLEN;
411 * snp_tty == NULL is for inactive snoop devices.
414 snp->snp_target = NODEV;
416 LIST_INSERT_HEAD(&snp_sclist, snp, snp_list);
431 * If line disc. changed we do not touch this pointer, SLIP/PPP will
438 if (tp && (tp->t_sc == snp) && (tp->t_state & TS_SNOOP) &&
439 tp->t_line == snooplinedisc) {
441 tp->t_state &= ~TS_SNOOP;
442 tp->t_line = snp->snp_olddisc;
444 printf("snp%d: bad attached tty data\n", snp->snp_unit);
447 snp->snp_target = NODEV;
450 selwakeup(&snp->snp_sel);
451 if ((snp->snp_flags & SNOOP_OPEN) == 0)
458 snpclose(dev, flags, fmt, td)
468 LIST_REMOVE(snp, snp_list);
469 free(snp->snp_buf, M_SNP);
470 snp->snp_flags &= ~SNOOP_OPEN;
473 return (snp_detach(snp));
481 if (snp->snp_blen != SNOOP_MINLEN) {
482 free(snp->snp_buf, M_SNP);
483 snp->snp_buf = malloc(SNOOP_MINLEN, M_SNP, M_WAITOK);
484 snp->snp_blen = SNOOP_MINLEN;
486 snp->snp_flags |= SNOOP_DOWN;
488 return (snp_detach(snp));
492 snpioctl(dev, cmd, data, flags, td)
500 struct tty *tp, *tpo;
507 tdev = udev2dev(*((udev_t *)data), 0);
509 return (snp_down(snp));
511 tp = snpdevtotty(tdev);
514 if (tp->t_state & TS_SNOOP)
519 if (snp->snp_target == NODEV) {
522 tpo->t_state &= ~TS_SNOOP;
525 tp->t_sc = (caddr_t)snp;
526 tp->t_state |= TS_SNOOP;
527 snp->snp_olddisc = tp->t_line;
528 tp->t_line = snooplinedisc;
530 snp->snp_target = tdev;
533 * Clean overflow and down flags -
534 * we'll have a chance to get them in the future :)))
536 snp->snp_flags &= ~SNOOP_OFLOW;
537 snp->snp_flags &= ~SNOOP_DOWN;
543 * We keep snp_target field specially to make
544 * SNPGTTY happy, else we can't know what is device
545 * major/minor for tty.
547 *((dev_t *)data) = snp->snp_target;
555 snp->snp_flags |= SNOOP_ASYNC;
557 snp->snp_flags &= ~SNOOP_ASYNC;
562 if (snp->snp_tty != NULL)
563 *(int *)data = snp->snp_len;
565 if (snp->snp_flags & SNOOP_DOWN) {
566 if (snp->snp_flags & SNOOP_OFLOW)
567 *(int *)data = SNP_OFLOW;
569 *(int *)data = SNP_TTYCLOSE;
571 *(int *)data = SNP_DETACH;
583 snppoll(dev, events, td)
594 * If snoop is down, we don't want to poll() forever so we return 1.
595 * Caller should see if we down via FIONREAD ioctl(). The last should
596 * return -1 to indicate down state.
598 if (events & (POLLIN | POLLRDNORM)) {
599 if (snp->snp_flags & SNOOP_DOWN || snp->snp_len > 0)
600 revents |= events & (POLLIN | POLLRDNORM);
602 selrecord(td, &snp->snp_sel);
608 snp_clone(arg, name, namelen, dev)
618 if (dev_stdclone(name, NULL, "snp", &u) != 1)
620 *dev = make_dev(&snp_cdevsw, unit2minor(u), UID_ROOT, GID_WHEEL, 0600,
622 if (snpbasedev == NOUDEV)
623 snpbasedev = (*dev)->si_udev;
625 (*dev)->si_flags |= SI_CHEAPCLONE;
626 dev_depends(udev2dev(snpbasedev, 0), *dev);
631 snp_modevent(mod, type, data)
636 static eventhandler_tag eh_tag;
640 /* XXX error checking. */
641 eh_tag = EVENTHANDLER_REGISTER(dev_clone, snp_clone, 0, 1000);
642 snooplinedisc = ldisc_register(LDISC_LOAD, &snpdisc);
643 cdevsw_add(&snp_cdevsw);
646 if (!LIST_EMPTY(&snp_sclist))
648 EVENTHANDLER_DEREGISTER(dev_clone, eh_tag);
649 if (snpbasedev != NOUDEV)
650 destroy_dev(udev2dev(snpbasedev, 0));
651 ldisc_deregister(snooplinedisc);
652 cdevsw_remove(&snp_cdevsw);
660 static moduledata_t snp_mod = {
665 DECLARE_MODULE(snp, snp_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE + CDEV_MAJOR);