1 /*-
2  * (MPSAFE)
3  *
4  * Copyright (c) 2001-2002 Maksim Yevmenkin <m_evmenkin@yahoo.com>
5  * All rights reserved.
6  *
7  * ng_h4.c
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  *
30  * $Id: ng_h4.c,v 1.10 2005/10/31 17:57:43 max Exp $
31  * $FreeBSD: head/sys/netgraph/bluetooth/drivers/h4/ng_h4.c 243882 2012-12-05 08:04:20Z glebius $
32  *
33  * Based on:
34  * ---------
35  *
36  * FreeBSD: src/sys/netgraph/ng_tty.c
37  * Author: Archie Cobbs <archie@freebsd.org>
38  *
39  */
40 
41 #include <sys/param.h>
42 #include <sys/systm.h>
43 #include <sys/kernel.h>
44 #include <sys/conf.h>
45 #include <sys/endian.h>
46 #include <sys/errno.h>
47 #include <sys/fcntl.h>
48 #include <sys/malloc.h>
49 #include <sys/mbuf.h>
50 #include <sys/caps.h>
51 #include <sys/socket.h>
52 #include <sys/tty.h>
53 #include <sys/ttycom.h>
54 #include <net/if.h>
55 #include <net/if_var.h>
56 #include <netgraph7/ng_message.h>
57 #include <netgraph7/netgraph.h>
58 #include <netgraph7/ng_parse.h>
59 #include <netgraph7/bluetooth/include/ng_bluetooth.h>
60 #include <netgraph7/bluetooth/include/ng_hci.h>
61 #include <netgraph7/bluetooth/include/ng_h4.h>
62 #include <netgraph7/bluetooth/drivers/h4/ng_h4_var.h>
63 #include <netgraph7/bluetooth/drivers/h4/ng_h4_prse.h>
64 
65 /*****************************************************************************
66  *****************************************************************************
67  ** This node implements a Bluetooth HCI UART transport layer as per chapter
68  ** H4 of the Bluetooth Specification Book v1.1. It is a terminal line
69  ** discipline that is also a netgraph node. Installing this line discipline
70  ** on a terminal device instantiates a new netgraph node of this type, which
71  ** allows access to the device via the "hook" hook of the node.
72  **
73  ** Once the line discipline is installed, you can find out the name of the
74  ** corresponding netgraph node via a NGIOCGINFO ioctl().
75  *****************************************************************************
76  *****************************************************************************/
77 
78 /* MALLOC define */
79 #ifndef NG_SEPARATE_MALLOC
80 MALLOC_DEFINE(M_NETGRAPH_H4, "netgraph_h4", "Netgraph Bluetooth H4 node");
81 #else
82 #define M_NETGRAPH_H4 M_NETGRAPH
83 #endif /* NG_SEPARATE_MALLOC */
84 
85 /* Line discipline methods */
86 static int	ng_h4_open	(struct cdev *, struct tty *);
87 static int	ng_h4_close	(struct tty *, int);
88 static int	ng_h4_read	(struct tty *, struct uio *, int);
89 static int	ng_h4_write	(struct tty *, struct uio *, int);
90 static int	ng_h4_input	(int, struct tty *);
91 static int	ng_h4_start	(struct tty *);
92 static int	ng_h4_ioctl	(struct tty *, u_long, caddr_t,
93 					int, struct ucred *);
94 
95 /* Line discipline descriptor */
96 static struct linesw		ng_h4_disc = {
97 	ng_h4_open,		/* open */
98 	ng_h4_close,		/* close */
99 	ng_h4_read,		/* read */
100 	ng_h4_write,		/* write */
101 	ng_h4_ioctl,		/* ioctl */
102 	ng_h4_input,		/* input */
103 	ng_h4_start,		/* start */
104 	ttymodem		/* modem */
105 };
106 
107 /* Netgraph methods */
108 static ng_constructor_t		ng_h4_constructor;
109 static ng_rcvmsg_t		ng_h4_rcvmsg;
110 static ng_shutdown_t		ng_h4_shutdown;
111 static ng_newhook_t		ng_h4_newhook;
112 static ng_connect_t		ng_h4_connect;
113 static ng_rcvdata_t		ng_h4_rcvdata;
114 static ng_disconnect_t		ng_h4_disconnect;
115 
116 /* Other stuff */
117 static void	ng_h4_process_timeout	(node_p, hook_p, void *, int);
118 static int	ng_h4_mod_event		(module_t, int, void *);
119 
120 /* Netgraph node type descriptor */
121 static struct ng_type		typestruct = {
122 	.version =	NG_ABI_VERSION,
123 	.name =		NG_H4_NODE_TYPE,
124 	.mod_event =	ng_h4_mod_event,
125 	.constructor =	ng_h4_constructor,
126 	.rcvmsg =	ng_h4_rcvmsg,
127 	.shutdown =	ng_h4_shutdown,
128 	.newhook =	ng_h4_newhook,
129 	.connect =	ng_h4_connect,
130 	.rcvdata =	ng_h4_rcvdata,
131 	.disconnect =	ng_h4_disconnect,
132 	.cmdlist =	ng_h4_cmdlist
133 };
134 NETGRAPH_INIT(h4, &typestruct);
135 MODULE_VERSION(ng_h4, NG_BLUETOOTH_VERSION);
136 
137 static int	ng_h4_node = 0;
138 
139 /*****************************************************************************
140  *****************************************************************************
141  **			    Line discipline methods
142  *****************************************************************************
143  *****************************************************************************/
144 
145 /*
146  * Set our line discipline on the tty.
147  */
148 
149 static int
150 ng_h4_open(struct cdev *dev, struct tty *tp)
151 {
152 	char		 name[NG_NODESIZ];
153 	ng_h4_info_p	 sc = NULL;
154 	int		 error;
155 
156 	/* Super-user only */
157 	error = caps_priv_check_self(SYSCAP_NONET_NETGRAPH);
158 	if (error != 0)
159 		return (error);
160 
161 	/* Initialize private struct */
162 	sc = kmalloc(sizeof(*sc), M_NETGRAPH_H4, M_WAITOK | M_NULLOK | M_ZERO);
163 	if (sc == NULL)
164 		return (ENOMEM);
165 
166 	lwkt_gettoken(&tp->t_token);
167 	sc->tp = tp;
168 	sc->debug = NG_H4_WARN_LEVEL;
169 
170 	sc->state = NG_H4_W4_PKT_IND;
171 	sc->want = 1;
172 	sc->got = 0;
173 
174 	sc->outq.ifq_maxlen = NG_H4_DEFAULTQLEN;
175 	ng_callout_init(&sc->timo);
176 
177 	NG_H4_LOCK(sc);
178 
179 	/* Setup netgraph node */
180 	error = ng_make_node_common(&typestruct, &sc->node);
181 	if (error != 0) {
182 		NG_H4_UNLOCK(sc);
183 
184 		kprintf("%s: Unable to create new node!\n", __func__);
185 
186 		bzero(sc, sizeof(*sc));
187 		kfree(sc, M_NETGRAPH_H4);
188 
189 		lwkt_reltoken(&tp->t_token);
190 		return (error);
191 	}
192 
193 	/* Assign node its name */
194 	ksnprintf(name, sizeof(name), "%s%d", typestruct.name, ng_h4_node ++);
195 
196 	error = ng_name_node(sc->node, name);
197 	if (error != 0) {
198 		NG_H4_UNLOCK(sc);
199 
200 		kprintf("%s: %s - node name exists?\n", __func__, name);
201 
202 		NG_NODE_UNREF(sc->node);
203 		bzero(sc, sizeof(*sc));
204 		kfree(sc, M_NETGRAPH_H4);
205 
206 		lwkt_reltoken(&tp->t_token);
207 		return (error);
208 	}
209 
210 	/* Set back pointers */
211 	NG_NODE_SET_PRIVATE(sc->node, sc);
212 	tp->t_sc = (caddr_t) sc;
213 
214 	/* The node has to be a WRITER because data can change node status */
215 	NG_NODE_FORCE_WRITER(sc->node);
216 
217 	/*
218 	 * Pre-allocate cblocks to the an appropriate amount.
219 	 * I'm not sure what is appropriate.
220 	 */
221 
222 	ttyflush(tp, FREAD | FWRITE);
223 	clist_alloc_cblocks(&tp->t_canq, 0);
224 	clist_alloc_cblocks(&tp->t_rawq, 0);
225 	clist_alloc_cblocks(&tp->t_outq, MLEN + NG_H4_HIWATER);
226 
227 	NG_H4_UNLOCK(sc);
228 
229 	lwkt_reltoken(&tp->t_token);
230 	return (error);
231 } /* ng_h4_open */
232 
233 /*
234  * Line specific close routine, called from device close routine
235  * and from ttioctl. This causes the node to be destroyed as well.
236  */
237 
238 static int
239 ng_h4_close(struct tty *tp, int flag)
240 {
241 	ng_h4_info_p	sc = (ng_h4_info_p) tp->t_sc;
242 
243 	lwkt_gettoken(&tp->t_token);
244 	ttyflush(tp, FREAD | FWRITE);
245 	clist_free_cblocks(&tp->t_outq);
246 
247 	if (sc != NULL) {
248 		NG_H4_LOCK(sc);
249 
250 		if (callout_pending(&sc->timo))
251 			ng_uncallout(&sc->timo, sc->node);
252 
253 		tp->t_sc = NULL;
254 		sc->dying = 1;
255 
256 		NG_H4_UNLOCK(sc);
257 
258 		ng_rmnode_self(sc->node);
259 	}
260 
261 	lwkt_reltoken(&tp->t_token);
262 	return (0);
263 } /* ng_h4_close */
264 
265 /*
266  * Once the device has been turned into a node, we don't allow reading.
267  */
268 
269 static int
270 ng_h4_read(struct tty *tp, struct uio *uio, int flag)
271 {
272 	return (EIO);
273 } /* ng_h4_read */
274 
275 /*
276  * Once the device has been turned into a node, we don't allow writing.
277  */
278 
279 static int
280 ng_h4_write(struct tty *tp, struct uio *uio, int flag)
281 {
282 	return (EIO);
283 } /* ng_h4_write */
284 
285 /*
286  * We implement the NGIOCGINFO ioctl() defined in ng_message.h.
287  */
288 
289 static int
290 ng_h4_ioctl(struct tty *tp, u_long cmd, caddr_t data, int flag,
291     struct ucred *cred)
292 {
293 	ng_h4_info_p	sc = (ng_h4_info_p) tp->t_sc;
294 	int		error = 0;
295 
296 	if (sc == NULL)
297 		return (ENXIO);
298 
299 	lwkt_gettoken(&tp->t_token);
300 	NG_H4_LOCK(sc);
301 
302 	switch (cmd) {
303 	case NGIOCGINFO:
304 #undef	NI
305 #define NI(x)	((struct nodeinfo *)(x))
306 
307 		bzero(data, sizeof(*NI(data)));
308 
309 		if (NG_NODE_HAS_NAME(sc->node))
310 			strncpy(NI(data)->name, NG_NODE_NAME(sc->node),
311 				sizeof(NI(data)->name) - 1);
312 
313 		strncpy(NI(data)->type, sc->node->nd_type->name,
314 			sizeof(NI(data)->type) - 1);
315 
316 		NI(data)->id = (u_int32_t) ng_node2ID(sc->node);
317 		NI(data)->hooks = NG_NODE_NUMHOOKS(sc->node);
318 		break;
319 
320 	default:
321 		error = ENOIOCTL;
322 		break;
323 	}
324 
325 	NG_H4_UNLOCK(sc);
326 
327 	lwkt_reltoken(&tp->t_token);
328 	return (error);
329 } /* ng_h4_ioctl */
330 
331 /*
332  * Receive data coming from the device. We get one character at a time, which
333  * is kindof silly.
334  */
335 
336 static int
337 ng_h4_input(int c, struct tty *tp)
338 {
339 	ng_h4_info_p	sc = (ng_h4_info_p) tp->t_sc;
340 
341 	lwkt_gettoken(&tp->t_token);
342 	if (sc == NULL || tp != sc->tp ||
343 	    sc->node == NULL || NG_NODE_NOT_VALID(sc->node)) {
344 		lwkt_reltoken(&tp->t_token);
345 		return (0);
346 	}
347 
348 	NG_H4_LOCK(sc);
349 
350 	/* Check for error conditions */
351 	if ((tp->t_state & TS_CONNECTED) == 0) {
352 		NG_H4_INFO("%s: %s - no carrier\n", __func__,
353 			NG_NODE_NAME(sc->node));
354 
355 		sc->state = NG_H4_W4_PKT_IND;
356 		sc->want = 1;
357 		sc->got = 0;
358 
359 		NG_H4_UNLOCK(sc);
360 
361 		lwkt_reltoken(&tp->t_token);
362 		return (0); /* XXX Loss of synchronization here! */
363 	}
364 
365 	/* Check for framing error or overrun on this char */
366 	if (c & TTY_ERRORMASK) {
367 		NG_H4_ERR("%s: %s - line error %#x, c=%#x\n", __func__,
368 			NG_NODE_NAME(sc->node), c & TTY_ERRORMASK,
369 			c & TTY_CHARMASK);
370 
371 		NG_H4_STAT_IERROR(sc->stat);
372 
373 		sc->state = NG_H4_W4_PKT_IND;
374 		sc->want = 1;
375 		sc->got = 0;
376 
377 		NG_H4_UNLOCK(sc);
378 
379 		lwkt_reltoken(&tp->t_token);
380 		return (0); /* XXX Loss of synchronization here! */
381 	}
382 
383 	NG_H4_STAT_BYTES_RECV(sc->stat, 1);
384 
385 	/* Append char to mbuf */
386 	if (sc->got >= sizeof(sc->ibuf)) {
387 		NG_H4_ALERT("%s: %s - input buffer overflow, c=%#x, got=%d\n",
388 			__func__, NG_NODE_NAME(sc->node), c & TTY_CHARMASK,
389 			sc->got);
390 
391 		NG_H4_STAT_IERROR(sc->stat);
392 
393 		sc->state = NG_H4_W4_PKT_IND;
394 		sc->want = 1;
395 		sc->got = 0;
396 
397 		NG_H4_UNLOCK(sc);
398 
399 		lwkt_reltoken(&tp->t_token);
400 		return (0); /* XXX Loss of synchronization here! */
401 	}
402 
403 	sc->ibuf[sc->got ++] = (c & TTY_CHARMASK);
404 
405 	NG_H4_INFO("%s: %s - got char %#x, want=%d, got=%d\n", __func__,
406 		NG_NODE_NAME(sc->node), c, sc->want, sc->got);
407 
408 	if (sc->got < sc->want) {
409 		NG_H4_UNLOCK(sc);
410 
411 		lwkt_reltoken(&tp->t_token);
412 		return (0); /* Wait for more */
413 	}
414 
415 	switch (sc->state) {
416 	/* Got packet indicator */
417 	case NG_H4_W4_PKT_IND:
418 		NG_H4_INFO("%s: %s - got packet indicator %#x\n", __func__,
419 			NG_NODE_NAME(sc->node), sc->ibuf[0]);
420 
421 		sc->state = NG_H4_W4_PKT_HDR;
422 
423 		/*
424 		 * Since packet indicator included in the packet header
425 		 * just set sc->want to sizeof(packet header).
426 		 */
427 
428 		switch (sc->ibuf[0]) {
429 		case NG_HCI_ACL_DATA_PKT:
430 			sc->want = sizeof(ng_hci_acldata_pkt_t);
431 			break;
432 
433 		case NG_HCI_SCO_DATA_PKT:
434 			sc->want = sizeof(ng_hci_scodata_pkt_t);
435 			break;
436 
437 		case NG_HCI_EVENT_PKT:
438 			sc->want = sizeof(ng_hci_event_pkt_t);
439 			break;
440 
441 		default:
442 			NG_H4_WARN("%s: %s - ignoring unknown packet " \
443 				"type=%#x\n", __func__, NG_NODE_NAME(sc->node),
444 				sc->ibuf[0]);
445 
446 			NG_H4_STAT_IERROR(sc->stat);
447 
448 			sc->state = NG_H4_W4_PKT_IND;
449 			sc->want = 1;
450 			sc->got = 0;
451 			break;
452 		}
453 		break;
454 
455 	/* Got packet header */
456 	case NG_H4_W4_PKT_HDR:
457 		sc->state = NG_H4_W4_PKT_DATA;
458 
459 		switch (sc->ibuf[0]) {
460 		case NG_HCI_ACL_DATA_PKT:
461 			c = le16toh(((ng_hci_acldata_pkt_t *)
462 				(sc->ibuf))->length);
463 			break;
464 
465 		case NG_HCI_SCO_DATA_PKT:
466 			c = ((ng_hci_scodata_pkt_t *)(sc->ibuf))->length;
467 			break;
468 
469 		case NG_HCI_EVENT_PKT:
470 			c = ((ng_hci_event_pkt_t *)(sc->ibuf))->length;
471 			break;
472 
473 		default:
474 			KASSERT((0), ("Invalid packet type=%#x",
475 				sc->ibuf[0]));
476 			break;
477 		}
478 
479 		NG_H4_INFO("%s: %s - got packet header, packet type=%#x, " \
480 			"packet size=%d, payload size=%d\n", __func__,
481 			NG_NODE_NAME(sc->node), sc->ibuf[0], sc->got, c);
482 
483 		if (c > 0) {
484 			sc->want += c;
485 
486 			/*
487 			 * Try to prevent possible buffer overrun
488 			 *
489 			 * XXX I'm *really* confused here. It turns out
490 			 * that Xircom card sends us packets with length
491 			 * greater then 512 bytes! This is greater then
492 			 * our old receive buffer (ibuf) size. In the same
493 			 * time the card demands from us *not* to send
494 			 * packets greater then 192 bytes. Weird! How the
495 			 * hell i should know how big *receive* buffer
496 			 * should be? For now increase receiving buffer
497 			 * size to 1K and add the following check.
498 			 */
499 
500 			if (sc->want >= sizeof(sc->ibuf)) {
501 				int	b;
502 
503 				NG_H4_ALERT("%s: %s - packet too big for " \
504 					"buffer, type=%#x, got=%d, want=%d, " \
505 					"length=%d\n", __func__,
506 					NG_NODE_NAME(sc->node), sc->ibuf[0],
507 					sc->got, sc->want, c);
508 
509 				NG_H4_ALERT("Packet header:\n");
510 				for (b = 0; b < sc->got; b++)
511 					NG_H4_ALERT("%#x ", sc->ibuf[b]);
512 				NG_H4_ALERT("\n");
513 
514 				/* Reset state */
515 				NG_H4_STAT_IERROR(sc->stat);
516 
517 				sc->state = NG_H4_W4_PKT_IND;
518 				sc->want = 1;
519 				sc->got = 0;
520 			}
521 
522 			break;
523 		}
524 
525 		/* else FALLTHROUGH and deliver frame */
526 		/* XXX Is this true? Should we deliver empty frame? */
527 
528 	/* Got packet data */
529 	case NG_H4_W4_PKT_DATA:
530 		NG_H4_INFO("%s: %s - got full packet, packet type=%#x, " \
531 			"packet size=%d\n", __func__,
532 			NG_NODE_NAME(sc->node), sc->ibuf[0], sc->got);
533 
534 		if (sc->hook != NULL && NG_HOOK_IS_VALID(sc->hook)) {
535 			struct mbuf	*m = NULL;
536 
537 			MGETHDR(m, M_NOWAIT, MT_DATA);
538 			if (m != NULL) {
539 				m->m_pkthdr.len = 0;
540 
541 				/* XXX m_copyback() is stupid */
542 				m->m_len = min(MHLEN, sc->got);
543 
544 				m_copyback(m, 0, sc->got, sc->ibuf);
545 				NG_SEND_DATA_ONLY(c, sc->hook, m);
546 			} else {
547 				NG_H4_ERR("%s: %s - could not get mbuf\n",
548 					__func__, NG_NODE_NAME(sc->node));
549 
550 				NG_H4_STAT_IERROR(sc->stat);
551 			}
552 		}
553 
554 		sc->state = NG_H4_W4_PKT_IND;
555 		sc->want = 1;
556 		sc->got = 0;
557 
558 		NG_H4_STAT_PCKTS_RECV(sc->stat);
559 		break;
560 
561 	default:
562 		KASSERT((0), ("Invalid H4 node state=%d", sc->state));
563 		break;
564 	}
565 
566 	NG_H4_UNLOCK(sc);
567 
568 	lwkt_reltoken(&tp->t_token);
569 	return (0);
570 } /* ng_h4_input */
571 
572 /*
573  * This is called when the device driver is ready for more output. Called from
574  * tty system.
575  */
576 
577 static int
578 ng_h4_start(struct tty *tp)
579 {
580 	ng_h4_info_p	 sc = (ng_h4_info_p) tp->t_sc;
581 	struct mbuf	*m = NULL;
582 	int		 size;
583 
584 	lwkt_gettoken(&tp->t_token);
585 	if (sc == NULL || tp != sc->tp ||
586 	    sc->node == NULL || NG_NODE_NOT_VALID(sc->node)) {
587 		lwkt_reltoken(&tp->t_token);
588 		return (0);
589 	}
590 
591 #if 0
592 	while (tp->t_outq.c_cc < NG_H4_HIWATER) { /* XXX 2.2 specific ? */
593 #else
594 	while (1) {
595 #endif
596 		/* Remove first mbuf from queue */
597 		IF_DEQUEUE(&sc->outq, m);
598 		if (m == NULL)
599 			break;
600 
601 		/* Send as much of it as possible */
602 		while (m != NULL) {
603 			size = m->m_len - clist_btoq(mtod(m, u_char *),
604 						     m->m_len, &tp->t_outq);
605 
606 			NG_H4_LOCK(sc);
607 			NG_H4_STAT_BYTES_SENT(sc->stat, size);
608 			NG_H4_UNLOCK(sc);
609 
610 			m->m_data += size;
611 			m->m_len -= size;
612 			if (m->m_len > 0)
613 				break;	/* device can't take no more */
614 
615 			m = m_free(m);
616 		}
617 
618 		/* Put remainder of mbuf chain (if any) back on queue */
619 		if (m != NULL) {
620 			IF_PREPEND(&sc->outq, m);
621 			break;
622 		}
623 
624 		/* Full packet has been sent */
625 		NG_H4_LOCK(sc);
626 		NG_H4_STAT_PCKTS_SENT(sc->stat);
627 		NG_H4_UNLOCK(sc);
628 	}
629 
630 	/*
631 	 * Call output process whether or not there is any output. We are
632 	 * being called in lieu of ttstart and must do what it would.
633 	 */
634 
635 	if (tp->t_oproc != NULL)
636 		(*tp->t_oproc) (tp);
637 
638 	/*
639 	 * This timeout is needed for operation on a pseudo-tty, because the
640 	 * pty code doesn't call pppstart after it has drained the t_outq.
641 	 */
642 
643 	NG_H4_LOCK(sc);
644 
645 	if (!IF_QEMPTY(&sc->outq) && !callout_pending(&sc->timo))
646 		ng_callout(&sc->timo, sc->node, NULL, 1,
647 			ng_h4_process_timeout, NULL, 0);
648 
649 	NG_H4_UNLOCK(sc);
650 
651 	lwkt_reltoken(&tp->t_token);
652 	return (0);
653 } /* ng_h4_start */
654 
655 /*****************************************************************************
656  *****************************************************************************
657  **			    Netgraph node methods
658  *****************************************************************************
659  *****************************************************************************/
660 
661 /*
662  * Initialize a new node of this type. We only allow nodes to be created as
663  * a result of setting the line discipline on a tty, so always return an error
664  * if not.
665  */
666 
667 static int
668 ng_h4_constructor(node_p node)
669 {
670 	return (EOPNOTSUPP);
671 } /* ng_h4_constructor */
672 
673 /*
674  * Add a new hook. There can only be one.
675  */
676 
677 static int
678 ng_h4_newhook(node_p node, hook_p hook, const char *name)
679 {
680 	ng_h4_info_p	sc = (ng_h4_info_p) NG_NODE_PRIVATE(node);
681 
682 	if (strcmp(name, NG_H4_HOOK) != 0)
683 		return (EINVAL);
684 
685 	NG_H4_LOCK(sc);
686 
687 	if (sc->hook != NULL) {
688 		NG_H4_UNLOCK(sc);
689 		return (EISCONN);
690 	}
691 	sc->hook = hook;
692 
693 	NG_H4_UNLOCK(sc);
694 
695 	return (0);
696 } /* ng_h4_newhook */
697 
698 /*
699  * Connect hook. Just say yes.
700  */
701 
702 static int
703 ng_h4_connect(hook_p hook)
704 {
705 	ng_h4_info_p	sc = (ng_h4_info_p) NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
706 
707 	if (hook != sc->hook)
708 		panic("%s: hook != sc->hook", __func__);
709 
710 	NG_HOOK_FORCE_QUEUE(NG_HOOK_PEER(hook));
711 	NG_HOOK_FORCE_QUEUE(hook);
712 
713 	return (0);
714 } /* ng_h4_connect */
715 
716 /*
717  * Disconnect the hook
718  */
719 
720 static int
721 ng_h4_disconnect(hook_p hook)
722 {
723 	ng_h4_info_p	sc = (ng_h4_info_p) NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
724 
725 	/*
726 	 * We need to check for sc != NULL because we can be called from
727 	 * ng_h4_close() via ng_rmnode_self()
728 	 */
729 
730 	if (sc != NULL) {
731 		if (hook != sc->hook)
732 			panic("%s: hook != sc->hook", __func__);
733 
734 		NG_H4_LOCK(sc);
735 
736 		/* XXX do we have to untimeout and drain out queue? */
737 		if (callout_pending(&sc->timo))
738 			ng_uncallout(&sc->timo, sc->node);
739 
740 		IF_DRAIN(&sc->outq);
741 
742 		sc->state = NG_H4_W4_PKT_IND;
743 		sc->want = 1;
744 		sc->got = 0;
745 
746 		sc->hook = NULL;
747 
748 		NG_H4_UNLOCK(sc);
749 	}
750 
751 	return (0);
752 } /* ng_h4_disconnect */
753 
754 /*
755  * Remove this node. The does the netgraph portion of the shutdown.
756  * This should only be called indirectly from ng_h4_close().
757  */
758 
759 static int
760 ng_h4_shutdown(node_p node)
761 {
762 	ng_h4_info_p	sc = (ng_h4_info_p) NG_NODE_PRIVATE(node);
763 
764 	NG_H4_LOCK(sc);
765 
766 	if (!sc->dying) {
767 		NG_H4_UNLOCK(sc);
768 
769 		NG_NODE_REVIVE(node);	/* we will persist */
770 
771 		return (EOPNOTSUPP);
772 	}
773 
774 	NG_H4_UNLOCK(sc);
775 
776 	NG_NODE_SET_PRIVATE(node, NULL);
777 
778 	IF_DRAIN(&sc->outq);
779 
780 	NG_NODE_UNREF(node);
781 	bzero(sc, sizeof(*sc));
782 	kfree(sc, M_NETGRAPH_H4);
783 
784 	return (0);
785 } /* ng_h4_shutdown */
786 
787 /*
788  * Receive incoming data from Netgraph system. Put it on our
789  * output queue and start output if necessary.
790  */
791 
792 static int
793 ng_h4_rcvdata(hook_p hook, item_p item)
794 {
795 	ng_h4_info_p	 sc = (ng_h4_info_p)NG_NODE_PRIVATE(NG_HOOK_NODE(hook));
796 	struct mbuf	*m = NULL;
797 	int		 qlen;
798 
799 	if (sc == NULL)
800 		return (EHOSTDOWN);
801 
802 	if (hook != sc->hook)
803 		panic("%s: hook != sc->hook", __func__);
804 
805 	NGI_GET_M(item, m);
806 	NG_FREE_ITEM(item);
807 
808 	NG_H4_LOCK(sc);
809 
810 	if (IF_QFULL(&sc->outq)) {
811 		NG_H4_ERR("%s: %s - dropping mbuf, len=%d\n", __func__,
812 			NG_NODE_NAME(sc->node), m->m_pkthdr.len);
813 
814 		NG_H4_STAT_OERROR(sc->stat);
815 		IF_DROP(&sc->outq);
816 
817 		NG_H4_UNLOCK(sc);
818 
819 		NG_FREE_M(m);
820 
821 		return (ENOBUFS);
822 	}
823 
824 	NG_H4_INFO("%s: %s - queue mbuf, len=%d\n", __func__,
825 		NG_NODE_NAME(sc->node), m->m_pkthdr.len);
826 
827 	IF_ENQUEUE(&sc->outq, m);
828 	qlen = IF_QLEN(&sc->outq);
829 
830 	NG_H4_UNLOCK(sc);
831 
832 	/*
833 	 * If qlen > 1, then we should already have a scheduled callout
834 	 */
835 
836 	if (qlen == 1)
837 		ng_h4_start(sc->tp);
838 
839 	return (0);
840 } /* ng_h4_rcvdata */
841 
842 /*
843  * Receive control message
844  */
845 
846 static int
847 ng_h4_rcvmsg(node_p node, item_p item, hook_p lasthook)
848 {
849 	ng_h4_info_p	 sc = (ng_h4_info_p) NG_NODE_PRIVATE(node);
850 	struct ng_mesg	*msg = NULL, *resp = NULL;
851 	int		 error = 0;
852 
853 	if (sc == NULL)
854 		return (EHOSTDOWN);
855 
856 	NGI_GET_MSG(item, msg);
857 	NG_H4_LOCK(sc);
858 
859 	switch (msg->header.typecookie) {
860 	case NGM_GENERIC_COOKIE:
861 		switch (msg->header.cmd) {
862 		case NGM_TEXT_STATUS:
863 			NG_MKRESPONSE(resp, msg, NG_TEXTRESPONSE, M_WAITOK | M_NULLOK);
864 			if (resp == NULL)
865 				error = ENOMEM;
866 			else
867 				ksnprintf(resp->data, NG_TEXTRESPONSE,
868 					"Hook: %s\n"   \
869 					"Debug: %d\n"  \
870 					"State: %d\n"  \
871 					"Queue: [have:%d,max:%d]\n" \
872 					"Input: [got:%d,want:%d]",
873 					(sc->hook != NULL)? NG_H4_HOOK : "",
874 					sc->debug,
875 					sc->state,
876 					IF_QLEN(&sc->outq),
877 					sc->outq.ifq_maxlen,
878 					sc->got,
879 					sc->want);
880 			break;
881 
882 		default:
883 			error = EINVAL;
884 			break;
885 		}
886 		break;
887 
888 	case NGM_H4_COOKIE:
889 		switch (msg->header.cmd) {
890 		case NGM_H4_NODE_RESET:
891 			IF_DRAIN(&sc->outq);
892 			sc->state = NG_H4_W4_PKT_IND;
893 			sc->want = 1;
894 			sc->got = 0;
895 			break;
896 
897 		case NGM_H4_NODE_GET_STATE:
898 			NG_MKRESPONSE(resp, msg, sizeof(ng_h4_node_state_ep),
899 				M_WAITOK | M_NULLOK);
900 			if (resp == NULL)
901 				error = ENOMEM;
902 			else
903 				*((ng_h4_node_state_ep *)(resp->data)) =
904 					sc->state;
905 			break;
906 
907 		case NGM_H4_NODE_GET_DEBUG:
908 			NG_MKRESPONSE(resp, msg, sizeof(ng_h4_node_debug_ep),
909 				M_WAITOK | M_NULLOK);
910 			if (resp == NULL)
911 				error = ENOMEM;
912 			else
913 				*((ng_h4_node_debug_ep *)(resp->data)) =
914 					sc->debug;
915 			break;
916 
917 		case NGM_H4_NODE_SET_DEBUG:
918 			if (msg->header.arglen != sizeof(ng_h4_node_debug_ep))
919 				error = EMSGSIZE;
920 			else
921 				sc->debug =
922 					*((ng_h4_node_debug_ep *)(msg->data));
923 			break;
924 
925 		case NGM_H4_NODE_GET_QLEN:
926 			NG_MKRESPONSE(resp, msg, sizeof(ng_h4_node_qlen_ep),
927 				M_WAITOK | M_NULLOK);
928 			if (resp == NULL)
929 				error = ENOMEM;
930 			else
931 				*((ng_h4_node_qlen_ep *)(resp->data)) =
932 					sc->outq.ifq_maxlen;
933 			break;
934 
935 		case NGM_H4_NODE_SET_QLEN:
936 			if (msg->header.arglen != sizeof(ng_h4_node_qlen_ep))
937 				error = EMSGSIZE;
938 			else if (*((ng_h4_node_qlen_ep *)(msg->data)) <= 0)
939 				error = EINVAL;
940 			else
941 				sc->outq.ifq_maxlen =
942 					*((ng_h4_node_qlen_ep *)(msg->data));
943 			break;
944 
945 		case NGM_H4_NODE_GET_STAT:
946 			NG_MKRESPONSE(resp, msg, sizeof(ng_h4_node_stat_ep),
947 				M_WAITOK | M_NULLOK);
948 			if (resp == NULL)
949 				error = ENOMEM;
950 			else
951 				bcopy(&sc->stat, resp->data,
952 					sizeof(ng_h4_node_stat_ep));
953 			break;
954 
955 		case NGM_H4_NODE_RESET_STAT:
956 			NG_H4_STAT_RESET(sc->stat);
957 			break;
958 
959 		default:
960 			error = EINVAL;
961 			break;
962 		}
963 		break;
964 
965 	default:
966 		error = EINVAL;
967 		break;
968 	}
969 
970 	NG_H4_UNLOCK(sc);
971 
972 	NG_RESPOND_MSG(error, node, item, resp);
973 	NG_FREE_MSG(msg);
974 
975 	return (error);
976 } /* ng_h4_rcvmsg */
977 
978 /*
979  * Timeout processing function.
980  * We still have data to output to the device, so try sending more.
981  */
982 
983 static void
984 ng_h4_process_timeout(node_p node, hook_p hook, void *arg1, int arg2)
985 {
986 	ng_h4_info_p	sc = (ng_h4_info_p) NG_NODE_PRIVATE(node);
987 
988 	ng_h4_start(sc->tp);
989 } /* ng_h4_process_timeout */
990 
991 /*
992  * Handle loading and unloading for this node type
993  */
994 
995 static int
996 ng_h4_mod_event(module_t mod, int event, void *data)
997 {
998 	static int	ng_h4_ldisc;
999 	int		error = 0;
1000 
1001 	switch (event) {
1002 	case MOD_LOAD:
1003 		/* Register line discipline */
1004 		crit_enter();
1005 		ng_h4_ldisc = ldisc_register(BTUARTDISC, &ng_h4_disc);
1006 		crit_exit();
1007 
1008 		if (ng_h4_ldisc < 0) {
1009 			kprintf("%s: can't register H4 line discipline\n",
1010 				__func__);
1011 			error = EIO;
1012 		}
1013 		break;
1014 
1015 	case MOD_UNLOAD:
1016 		/* Unregister line discipline */
1017 		crit_enter();
1018 		ldisc_deregister(ng_h4_ldisc);
1019 		crit_exit();
1020 		break;
1021 
1022 	default:
1023 		error = EOPNOTSUPP;
1024 		break;
1025 	}
1026 
1027 	return (error);
1028 } /* ng_h4_mod_event */
1029 
1030