4 * Copyright (c) 1995 Ugen J.S.Antsilevich
6 * Redistribution and use in source forms, with and without modification,
7 * are permitted provided that this entire comment appears intact.
9 * Redistribution in binary form may occur without any restrictions.
10 * Obviously, it would be nice if you gave credit where credit is due
11 * but requiring it would be too onerous.
13 * This software is provided ``AS IS'' without any warranties of any kind.
17 * $FreeBSD: src/sys/dev/snp/snp.c,v 1.69.2.2 2002/05/06 07:30:02 dd Exp $
21 #include <sys/param.h>
22 #include <sys/systm.h>
23 #include <sys/filio.h>
24 #include <sys/malloc.h>
27 #include <sys/event.h>
28 #include <sys/kernel.h>
29 #include <sys/queue.h>
30 #include <sys/snoop.h>
31 #include <sys/thread2.h>
32 #include <sys/vnode.h>
33 #include <sys/device.h>
34 #include <sys/devfs.h>
36 static l_close_t snplclose;
37 static l_write_t snplwrite;
38 static d_open_t snpopen;
39 static d_close_t snpclose;
40 static d_read_t snpread;
41 static d_write_t snpwrite;
42 static d_ioctl_t snpioctl;
43 static d_kqfilter_t snpkqfilter;
44 static d_clone_t snpclone;
45 DEVFS_DEFINE_CLONE_BITMAP(snp);
47 static void snpfilter_detach(struct knote *);
48 static int snpfilter_rd(struct knote *, long);
49 static int snpfilter_wr(struct knote *, long);
52 #define SNP_PREALLOCATED_UNITS 4
54 #define SNP_PREALLOCATED_UNITS NSNP
57 static struct dev_ops snp_ops = {
64 .d_kqfilter = snpkqfilter
67 static struct linesw snpdisc = {
68 ttyopen, snplclose, ttread, snplwrite,
69 l_nullioctl, ttyinput, ttstart, ttymodem
73 * This is the main snoop per-device structure.
76 LIST_ENTRY(snoop) snp_list; /* List glue. */
77 cdev_t snp_target; /* Target tty device. */
78 struct tty *snp_tty; /* Target tty pointer. */
79 u_long snp_len; /* Possible length. */
80 u_long snp_base; /* Data base. */
81 u_long snp_blen; /* Used length. */
82 caddr_t snp_buf; /* Allocation pointer. */
83 int snp_flags; /* Flags. */
84 struct kqinfo snp_kq; /* Kqueue info. */
85 int snp_olddisc; /* Old line discipline. */
91 #define SNOOP_ASYNC 0x0002
92 #define SNOOP_OPEN 0x0004
93 #define SNOOP_RWAIT 0x0008
94 #define SNOOP_OFLOW 0x0010
95 #define SNOOP_DOWN 0x0020
100 #define SNOOP_MINLEN (4*1024) /* This should be power of 2.
101 * 4K tested to be the minimum
102 * for which on normal tty
103 * usage there is no need to
106 #define SNOOP_MAXLEN (64*1024) /* This one also,64K enough
107 * If we grow more,something
108 * really bad in this world..
111 static MALLOC_DEFINE(M_SNP, "snp", "Snoop device data");
113 * The number of the "snoop" line discipline. This gets determined at
116 static int snooplinedisc;
119 static LIST_HEAD(, snoop) snp_sclist = LIST_HEAD_INITIALIZER(&snp_sclist);
120 static struct lwkt_token snp_token = LWKT_TOKEN_INITIALIZER(snp_token);
122 static struct tty *snpdevtotty (cdev_t dev);
123 static int snp_detach (struct snoop *snp);
124 static int snp_down (struct snoop *snp);
125 static int snp_in (struct snoop *snp, char *buf, int n);
126 static int snp_modevent (module_t mod, int what, void *arg);
129 snplclose(struct tty *tp, int flag)
134 lwkt_gettoken(&snp_token);
136 error = snp_down(snp);
138 lwkt_reltoken(&snp_token);
141 lwkt_gettoken(&tp->t_token);
142 error = ttylclose(tp, flag);
143 lwkt_reltoken(&tp->t_token);
144 lwkt_reltoken(&snp_token);
150 snplwrite(struct tty *tp, struct uio *uio, int flag)
158 lwkt_gettoken(&tp->t_token);
162 while (uio->uio_resid > 0) {
163 ilen = (int)szmin(512, uio->uio_resid);
164 ibuf = kmalloc(ilen, M_SNP, M_WAITOK);
165 error = uiomove(ibuf, (size_t)ilen, uio);
168 snp_in(snp, ibuf, ilen);
169 /* Hackish, but probably the least of all evils. */
175 uio2.uio_resid = ilen;
176 uio2.uio_segflg = UIO_SYSSPACE;
177 uio2.uio_rw = UIO_WRITE;
178 uio2.uio_td = uio->uio_td;
179 error = ttwrite(tp, &uio2, flag);
187 lwkt_reltoken(&tp->t_token);
192 snpdevtotty(cdev_t dev)
194 if ((dev_dflags(dev) & D_TTY) == 0)
196 return (dev->si_tty);
199 #define SNP_INPUT_BUF 5 /* This is even too much, the maximal
200 * interactive mode write is 3 bytes
201 * length for function keys...
205 snpwrite(struct dev_write_args *ap)
207 cdev_t dev = ap->a_head.a_dev;
208 struct uio *uio = ap->a_uio;
212 unsigned char c[SNP_INPUT_BUF];
216 lwkt_gettoken(&tp->t_token);
218 lwkt_reltoken(&tp->t_token);
221 if ((tp->t_sc == snp) && (tp->t_state & TS_SNOOP) &&
222 tp->t_line == snooplinedisc)
225 kprintf("Snoop: attempt to write to bad tty.\n");
226 lwkt_reltoken(&tp->t_token);
230 if (!(tp->t_state & TS_ISOPEN)) {
231 lwkt_reltoken(&tp->t_token);
235 while (uio->uio_resid > 0) {
236 len = (int)szmin(uio->uio_resid, SNP_INPUT_BUF);
237 if ((error = uiomove(c, (size_t)len, uio)) != 0) {
238 lwkt_reltoken(&tp->t_token);
241 for (i=0; i < len; i++) {
242 if (ttyinput(c[i], tp)) {
243 lwkt_reltoken(&tp->t_token);
248 lwkt_reltoken(&tp->t_token);
254 snpread(struct dev_read_args *ap)
256 cdev_t dev = ap->a_head.a_dev;
257 struct uio *uio = ap->a_uio;
260 int error, len, n, nblen;
266 lwkt_gettoken(&tp->t_token);
267 KASSERT(snp->snp_len + snp->snp_base <= snp->snp_blen,
268 ("snoop buffer error"));
270 if (snp->snp_tty == NULL) {
271 lwkt_reltoken(&tp->t_token);
275 snp->snp_flags &= ~SNOOP_RWAIT;
278 if (snp->snp_len == 0) {
279 if (ap->a_ioflag & IO_NDELAY) {
280 lwkt_reltoken(&tp->t_token);
281 return (EWOULDBLOCK);
283 snp->snp_flags |= SNOOP_RWAIT;
284 error = tsleep((caddr_t)snp, PCATCH, "snprd", 0);
286 lwkt_reltoken(&tp->t_token);
290 } while (snp->snp_len == 0);
295 while (snp->snp_len > 0 && uio->uio_resid > 0 && error == 0) {
296 len = (int)szmin(uio->uio_resid, snp->snp_len);
297 from = (caddr_t)(snp->snp_buf + snp->snp_base);
301 error = uiomove(from, (size_t)len, uio);
302 snp->snp_base += len;
305 if ((snp->snp_flags & SNOOP_OFLOW) && (n < snp->snp_len)) {
306 snp->snp_flags &= ~SNOOP_OFLOW;
308 nblen = snp->snp_blen;
309 if (((nblen / 2) >= SNOOP_MINLEN) && (nblen / 2) >= snp->snp_len) {
310 while (nblen / 2 >= snp->snp_len && nblen / 2 >= SNOOP_MINLEN)
312 if ((nbuf = kmalloc(nblen, M_SNP, M_NOWAIT)) != NULL) {
313 bcopy(snp->snp_buf + snp->snp_base, nbuf, snp->snp_len);
314 kfree(snp->snp_buf, M_SNP);
316 snp->snp_blen = nblen;
320 lwkt_reltoken(&tp->t_token);
326 * NOTE: Must be called with tp->t_token held
329 snp_in(struct snoop *snp, char *buf, int n)
336 KASSERT(n >= 0, ("negative snoop char count"));
341 if (snp->snp_flags & SNOOP_DOWN) {
342 kprintf("Snoop: more data to down interface.\n");
346 if (snp->snp_flags & SNOOP_OFLOW) {
347 kprintf("Snoop: buffer overflow.\n");
349 * On overflow we just repeat the standart close
350 * procedure...yes , this is waste of space but.. Then next
351 * read from device will fail if one would recall he is
352 * snooping and retry...
355 return (snp_down(snp));
357 s_tail = snp->snp_blen - (snp->snp_len + snp->snp_base);
358 s_free = snp->snp_blen - snp->snp_len;
362 nblen = snp->snp_blen;
363 while ((n > s_free) && ((nblen * 2) <= SNOOP_MAXLEN)) {
364 nblen = snp->snp_blen * 2;
365 s_free = nblen - (snp->snp_len + snp->snp_base);
367 if ((n <= s_free) && (nbuf = kmalloc(nblen, M_SNP, M_NOWAIT))) {
368 bcopy(snp->snp_buf + snp->snp_base, nbuf, snp->snp_len);
369 kfree(snp->snp_buf, M_SNP);
371 snp->snp_blen = nblen;
374 snp->snp_flags |= SNOOP_OFLOW;
375 if (snp->snp_flags & SNOOP_RWAIT) {
376 snp->snp_flags &= ~SNOOP_RWAIT;
377 wakeup((caddr_t)snp);
383 from = (caddr_t)(snp->snp_buf + snp->snp_base);
384 to = (caddr_t)(snp->snp_buf);
386 bcopy(from, to, len);
389 to = (caddr_t)(snp->snp_buf + snp->snp_base + snp->snp_len);
393 if (snp->snp_flags & SNOOP_RWAIT) {
394 snp->snp_flags &= ~SNOOP_RWAIT;
395 wakeup((caddr_t)snp);
397 KNOTE(&snp->snp_kq.ki_note, 0);
403 snpopen(struct dev_open_args *ap)
405 cdev_t dev = ap->a_head.a_dev;
408 lwkt_gettoken(&snp_token);
409 if (dev->si_drv1 == NULL) {
411 make_dev(&snp_ops, minor(dev), UID_ROOT, GID_WHEEL,
412 0600, "snp%d", minor(dev));
414 dev->si_drv1 = snp = kmalloc(sizeof(*snp), M_SNP,
417 lwkt_reltoken(&snp_token);
422 * We intentionally do not OR flags with SNOOP_OPEN, but set them so
423 * all previous settings (especially SNOOP_OFLOW) will be cleared.
425 snp->snp_flags = SNOOP_OPEN;
427 snp->snp_buf = kmalloc(SNOOP_MINLEN, M_SNP, M_WAITOK);
428 snp->snp_blen = SNOOP_MINLEN;
433 * snp_tty == NULL is for inactive snoop devices.
436 snp->snp_target = NULL;
438 LIST_INSERT_HEAD(&snp_sclist, snp, snp_list);
439 lwkt_reltoken(&snp_token);
444 * NOTE: Must be called with snp_token held
447 snp_detach(struct snoop *snp)
451 ASSERT_LWKT_TOKEN_HELD(&snp_token);
456 * If line disc. changed we do not touch this pointer, SLIP/PPP will
463 lwkt_gettoken(&tp->t_token);
464 if ((tp->t_sc == snp) && (tp->t_state & TS_SNOOP) &&
465 tp->t_line == snooplinedisc) {
467 tp->t_state &= ~TS_SNOOP;
468 tp->t_line = snp->snp_olddisc;
470 kprintf("Snoop: bad attached tty data.\n");
472 lwkt_reltoken(&tp->t_token);
475 snp->snp_target = NULL;
478 KNOTE(&snp->snp_kq.ki_note, 0);
479 if ((snp->snp_flags & SNOOP_OPEN) == 0)
486 snpclose(struct dev_close_args *ap)
488 cdev_t dev = ap->a_head.a_dev;
492 lwkt_gettoken(&snp_token);
495 LIST_REMOVE(snp, snp_list);
496 kfree(snp->snp_buf, M_SNP);
497 snp->snp_flags &= ~SNOOP_OPEN;
499 if (dev->si_uminor >= SNP_PREALLOCATED_UNITS) {
500 devfs_clone_bitmap_put(&DEVFS_CLONE_BITMAP(snp), dev->si_uminor);
503 ret = snp_detach(snp);
504 lwkt_reltoken(&snp_token);
509 * NOTE: Must be called with snp_token held
512 snp_down(struct snoop *snp)
514 ASSERT_LWKT_TOKEN_HELD(&snp_token);
515 if (snp->snp_blen != SNOOP_MINLEN) {
516 kfree(snp->snp_buf, M_SNP);
517 snp->snp_buf = kmalloc(SNOOP_MINLEN, M_SNP, M_WAITOK);
518 snp->snp_blen = SNOOP_MINLEN;
520 snp->snp_flags |= SNOOP_DOWN;
522 return (snp_detach(snp));
526 snpioctl(struct dev_ioctl_args *ap)
528 cdev_t dev = ap->a_head.a_dev;
530 struct tty *tp, *tpo;
534 lwkt_gettoken(&snp_token);
539 tdev = udev2dev(*((udev_t *)ap->a_data), 0);
541 lwkt_reltoken(&snp_token);
546 tp = snpdevtotty(tdev);
548 lwkt_reltoken(&snp_token);
551 lwkt_gettoken(&tp->t_token);
552 if (tp->t_state & TS_SNOOP) {
553 lwkt_reltoken(&tp->t_token);
554 lwkt_reltoken(&snp_token);
558 if (snp->snp_target == NULL) {
561 tpo->t_state &= ~TS_SNOOP;
564 tp->t_sc = (caddr_t)snp;
565 tp->t_state |= TS_SNOOP;
566 snp->snp_olddisc = tp->t_line;
567 tp->t_line = snooplinedisc;
569 snp->snp_target = tdev;
572 * Clean overflow and down flags -
573 * we'll have a chance to get them in the future :)))
575 snp->snp_flags &= ~SNOOP_OFLOW;
576 snp->snp_flags &= ~SNOOP_DOWN;
577 lwkt_reltoken(&tp->t_token);
582 * We keep snp_target field specially to make
583 * SNPGTTY happy, else we can't know what is device
584 * major/minor for tty.
586 *((cdev_t *)ap->a_data) = snp->snp_target;
590 if (*(int *)ap->a_data)
591 snp->snp_flags |= SNOOP_ASYNC;
593 snp->snp_flags &= ~SNOOP_ASYNC;
597 if (snp->snp_tty != NULL) {
598 *(int *)ap->a_data = snp->snp_len;
600 if (snp->snp_flags & SNOOP_DOWN) {
601 if (snp->snp_flags & SNOOP_OFLOW)
602 *(int *)ap->a_data = SNP_OFLOW;
604 *(int *)ap->a_data = SNP_TTYCLOSE;
606 *(int *)ap->a_data = SNP_DETACH;
612 lwkt_reltoken(&snp_token);
615 lwkt_reltoken(&snp_token);
620 static struct filterops snpfiltops_rd =
621 { FILTEROP_ISFD, NULL, snpfilter_detach, snpfilter_rd };
622 static struct filterops snpfiltops_wr =
623 { FILTEROP_ISFD, NULL, snpfilter_detach, snpfilter_wr };
626 snpkqfilter(struct dev_kqfilter_args *ap)
628 cdev_t dev = ap->a_head.a_dev;
629 struct snoop *snp = dev->si_drv1;
630 struct knote *kn = ap->a_kn;
632 struct tty *tp = snp->snp_tty;
634 lwkt_gettoken(&tp->t_token);
637 switch (kn->kn_filter) {
639 kn->kn_fop = &snpfiltops_rd;
640 kn->kn_hook = (caddr_t)snp;
643 kn->kn_fop = &snpfiltops_wr;
644 kn->kn_hook = (caddr_t)snp;
647 ap->a_result = EOPNOTSUPP;
648 lwkt_reltoken(&tp->t_token);
652 klist = &snp->snp_kq.ki_note;
653 knote_insert(klist, kn);
654 lwkt_reltoken(&tp->t_token);
660 snpfilter_detach(struct knote *kn)
662 struct snoop *snp = (struct snoop *)kn->kn_hook;
665 klist = &snp->snp_kq.ki_note;
666 knote_remove(klist, kn);
670 snpfilter_rd(struct knote *kn, long hint)
672 struct snoop *snp = (struct snoop *)kn->kn_hook;
673 struct tty *tp = snp->snp_tty;
676 lwkt_gettoken(&tp->t_token);
678 * If snoop is down, we don't want to poll forever so we return 1.
679 * Caller should see if we down via FIONREAD ioctl(). The last should
680 * return -1 to indicate down state.
682 if (snp->snp_flags & SNOOP_DOWN || snp->snp_len > 0)
684 lwkt_reltoken(&tp->t_token);
690 snpfilter_wr(struct knote *kn, long hint)
692 /* Writing is always OK */
697 snpclone(struct dev_clone_args *ap)
701 lwkt_gettoken(&snp_token);
702 unit = devfs_clone_bitmap_get(&DEVFS_CLONE_BITMAP(snp), 0);
703 ap->a_dev = make_only_dev(&snp_ops, unit, UID_ROOT, GID_WHEEL, 0600,
705 lwkt_reltoken(&snp_token);
711 snp_modevent(module_t mod, int type, void *data)
715 lwkt_gettoken(&snp_token);
719 snooplinedisc = ldisc_register(LDISC_LOAD, &snpdisc);
720 make_autoclone_dev(&snp_ops, &DEVFS_CLONE_BITMAP(snp),
721 snpclone, UID_ROOT, GID_WHEEL, 0600, "snp");
723 for (i = 0; i < SNP_PREALLOCATED_UNITS; i++) {
724 make_dev(&snp_ops, i, UID_ROOT, GID_WHEEL, 0600, "snp%d", i);
725 devfs_clone_bitmap_set(&DEVFS_CLONE_BITMAP(snp), i);
729 if (!LIST_EMPTY(&snp_sclist)) {
730 lwkt_reltoken(&snp_token);
733 ldisc_deregister(snooplinedisc);
734 devfs_clone_handler_del("snp");
735 dev_ops_remove_all(&snp_ops);
736 devfs_clone_bitmap_uninit(&DEVFS_CLONE_BITMAP(snp));
741 lwkt_reltoken(&snp_token);
746 static moduledata_t snp_mod = {
751 DECLARE_MODULE(snp, snp_mod, SI_SUB_DRIVERS, SI_ORDER_MIDDLE);