xref: /freebsd/usr.sbin/bluetooth/btpand/bnep.c (revision b740c88bfb6453416926271c089262e7164dace3)
1 /*	$NetBSD: bnep.c,v 1.1 2008/08/17 13:20:57 plunky Exp $	*/
2 
3 /*-
4  * Copyright (c) 2008 Iain Hibbert
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 /* $FreeBSD$ */
29 
30 #include <sys/cdefs.h>
31 __RCSID("$NetBSD: bnep.c,v 1.1 2008/08/17 13:20:57 plunky Exp $");
32 
33 #include <sys/uio.h>
34 #define L2CAP_SOCKET_CHECKED
35 #include <bluetooth.h>
36 #include <sdp.h>
37 #include <stdarg.h>
38 #include <string.h>
39 #include <unistd.h>
40 
41 #include "btpand.h"
42 #include "bnep.h"
43 
44 static bool bnep_recv_extension(packet_t *);
45 static size_t bnep_recv_control(channel_t *, uint8_t *, size_t, bool);
46 static size_t bnep_recv_control_command_not_understood(channel_t *, uint8_t *, size_t);
47 static size_t bnep_recv_setup_connection_req(channel_t *, uint8_t *, size_t);
48 static size_t bnep_recv_setup_connection_rsp(channel_t *, uint8_t *, size_t);
49 static size_t bnep_recv_filter_net_type_set(channel_t *, uint8_t *, size_t);
50 static size_t bnep_recv_filter_net_type_rsp(channel_t *, uint8_t *, size_t);
51 static size_t bnep_recv_filter_multi_addr_set(channel_t *, uint8_t *, size_t);
52 static size_t bnep_recv_filter_multi_addr_rsp(channel_t *, uint8_t *, size_t);
53 
54 static bool bnep_pfilter(channel_t *, packet_t *);
55 static bool bnep_mfilter(channel_t *, packet_t *);
56 
57 static uint8_t NAP_UUID[] = {
58 	0x00, 0x00, 0x11, 0x16,
59 	0x00, 0x00,
60 	0x10, 0x00,
61 	0x80, 0x00,
62 	0x00, 0x80, 0x5f, 0x9b, 0x34, 0xfb
63 };
64 
65 static uint8_t GN_UUID[] = {
66 	0x00, 0x00, 0x11, 0x17,
67 	0x00, 0x00,
68 	0x10, 0x00,
69 	0x80, 0x00,
70 	0x00, 0x80, 0x5f, 0x9b, 0x34, 0xfb,
71 };
72 
73 static uint8_t PANU_UUID[] = {
74 	0x00, 0x00, 0x11, 0x15,
75 	0x00, 0x00,
76 	0x10, 0x00,
77 	0x80, 0x00,
78 	0x00, 0x80, 0x5f, 0x9b, 0x34, 0xfb
79 };
80 
81 /*
82  * receive BNEP packet
83  * return true if packet is to be forwarded
84  */
85 bool
86 bnep_recv(packet_t *pkt)
87 {
88 	size_t len;
89 	uint8_t type;
90 
91 	if (pkt->len < 1)
92 		return false;
93 
94 	type = pkt->ptr[0];
95 	packet_adj(pkt, 1);
96 
97 	switch (BNEP_TYPE(type)) {
98 	case BNEP_GENERAL_ETHERNET:
99 		if (pkt->len < (ETHER_ADDR_LEN * 2) + ETHER_TYPE_LEN) {
100 			log_debug("dropped short packet (type 0x%2.2x)", type);
101 			return false;
102 		}
103 
104 		pkt->dst = pkt->ptr;
105 		packet_adj(pkt, ETHER_ADDR_LEN);
106 		pkt->src = pkt->ptr;
107 		packet_adj(pkt, ETHER_ADDR_LEN);
108 		pkt->type = pkt->ptr;
109 		packet_adj(pkt, ETHER_TYPE_LEN);
110 		break;
111 
112 	case BNEP_CONTROL:
113 		len = bnep_recv_control(pkt->chan, pkt->ptr, pkt->len, false);
114 		if (len == 0)
115 			return false;
116 
117 		packet_adj(pkt, len);
118 		break;
119 
120 	case BNEP_COMPRESSED_ETHERNET:
121 		if (pkt->len < ETHER_TYPE_LEN) {
122 			log_debug("dropped short packet (type 0x%2.2x)", type);
123 			return false;
124 		}
125 
126 		pkt->dst = pkt->chan->laddr;
127 		pkt->src = pkt->chan->raddr;
128 		pkt->type = pkt->ptr;
129 		packet_adj(pkt, ETHER_TYPE_LEN);
130 		break;
131 
132 	case BNEP_COMPRESSED_ETHERNET_SRC_ONLY:
133 		if (pkt->len < ETHER_ADDR_LEN + ETHER_TYPE_LEN) {
134 			log_debug("dropped short packet (type 0x%2.2x)", type);
135 			return false;
136 		}
137 
138 		pkt->dst = pkt->chan->laddr;
139 		pkt->src = pkt->ptr;
140 		packet_adj(pkt, ETHER_ADDR_LEN);
141 		pkt->type = pkt->ptr;
142 		packet_adj(pkt, ETHER_TYPE_LEN);
143 		break;
144 
145 	case BNEP_COMPRESSED_ETHERNET_DST_ONLY:
146 		if (pkt->len < ETHER_ADDR_LEN + ETHER_TYPE_LEN) {
147 			log_debug("dropped short packet (type 0x%2.2x)", type);
148 			return false;
149 		}
150 
151 		pkt->dst = pkt->ptr;
152 		packet_adj(pkt, ETHER_ADDR_LEN);
153 		pkt->src = pkt->chan->raddr;
154 		pkt->type = pkt->ptr;
155 		packet_adj(pkt, ETHER_TYPE_LEN);
156 		break;
157 
158 	default:
159 		/*
160 		 * Any packet containing a reserved BNEP
161 		 * header packet type SHALL be dropped.
162 		 */
163 
164 		log_debug("dropped packet with reserved type 0x%2.2x", type);
165 		return false;
166 	}
167 
168 	if (BNEP_TYPE_EXT(type)
169 	    && !bnep_recv_extension(pkt))
170 		return false;	/* invalid extensions */
171 
172 	if (BNEP_TYPE(type) == BNEP_CONTROL
173 	    || pkt->chan->state != CHANNEL_OPEN)
174 		return false;	/* no forwarding */
175 
176 	return true;
177 }
178 
179 static bool
180 bnep_recv_extension(packet_t *pkt)
181 {
182 	exthdr_t *eh;
183 	size_t len, size;
184 	uint8_t type;
185 
186 	do {
187 		if (pkt->len < 2)
188 			return false;
189 
190 		type = pkt->ptr[0];
191 		size = pkt->ptr[1];
192 
193 		if (pkt->len < size + 2)
194 			return false;
195 
196 		switch (type) {
197 		case BNEP_EXTENSION_CONTROL:
198 			len = bnep_recv_control(pkt->chan, pkt->ptr + 2, size, true);
199 			if (len != size)
200 				log_err("ignored spurious data in exthdr");
201 
202 			break;
203 
204 		default:
205 			/* Unknown extension headers in data packets	 */
206 			/* SHALL be forwarded irrespective of any	 */
207 			/* network protocol or multicast filter settings */
208 			/* and any local filtering policy.		 */
209 
210 			eh = malloc(sizeof(exthdr_t));
211 			if (eh == NULL) {
212 				log_err("exthdr malloc() failed: %m");
213 				break;
214 			}
215 
216 			eh->ptr = pkt->ptr;
217 			eh->len = size;
218 			STAILQ_INSERT_TAIL(&pkt->extlist, eh, next);
219 			break;
220 		}
221 
222 		packet_adj(pkt, size + 2);
223 	} while (BNEP_TYPE_EXT(type));
224 
225 	return true;
226 }
227 
228 static size_t
229 bnep_recv_control(channel_t *chan, uint8_t *ptr, size_t size, bool isext)
230 {
231 	uint8_t type;
232 	size_t len;
233 
234 	if (size-- < 1)
235 		return 0;
236 
237 	type = *ptr++;
238 
239 	switch (type) {
240 	case BNEP_CONTROL_COMMAND_NOT_UNDERSTOOD:
241 		len = bnep_recv_control_command_not_understood(chan, ptr, size);
242 		break;
243 
244 	case BNEP_SETUP_CONNECTION_REQUEST:
245 		if (isext)
246 			return 0;	/* not allowed in extension headers */
247 
248 		len = bnep_recv_setup_connection_req(chan, ptr, size);
249 		break;
250 
251 	case BNEP_SETUP_CONNECTION_RESPONSE:
252 		if (isext)
253 			return 0;	/* not allowed in extension headers */
254 
255 		len = bnep_recv_setup_connection_rsp(chan, ptr, size);
256 		break;
257 
258 	case BNEP_FILTER_NET_TYPE_SET:
259 		len = bnep_recv_filter_net_type_set(chan, ptr, size);
260 		break;
261 
262 	case BNEP_FILTER_NET_TYPE_RESPONSE:
263 		len = bnep_recv_filter_net_type_rsp(chan, ptr, size);
264 		break;
265 
266 	case BNEP_FILTER_MULTI_ADDR_SET:
267 		len = bnep_recv_filter_multi_addr_set(chan, ptr, size);
268 		break;
269 
270 	case BNEP_FILTER_MULTI_ADDR_RESPONSE:
271 		len = bnep_recv_filter_multi_addr_rsp(chan, ptr, size);
272 		break;
273 
274 	default:
275 		len = 0;
276 		break;
277 	}
278 
279 	if (len == 0)
280 		bnep_send_control(chan, BNEP_CONTROL_COMMAND_NOT_UNDERSTOOD, type);
281 
282 	return len;
283 }
284 
285 static size_t
286 bnep_recv_control_command_not_understood(channel_t *chan, uint8_t *ptr, size_t size)
287 {
288 	uint8_t type;
289 
290 	if (size < 1)
291 		return 0;
292 
293 	type = *ptr++;
294 	log_err("received Control Command Not Understood (0x%2.2x)", type);
295 
296 	/* we didn't send any reserved commands, just cut them off */
297 	channel_close(chan);
298 
299 	return 1;
300 }
301 
302 static size_t
303 bnep_recv_setup_connection_req(channel_t *chan, uint8_t *ptr, size_t size)
304 {
305 	uint8_t off;
306 	int src, dst, rsp;
307 	size_t len;
308 
309 	if (size < 1)
310 		return 0;
311 
312 	len = *ptr++;
313 	if (size < (len * 2 + 1))
314 		return 0;
315 
316 	if (chan->state != CHANNEL_WAIT_CONNECT_REQ
317 	    && chan->state != CHANNEL_OPEN) {
318 		log_debug("ignored");
319 		return (len * 2 + 1);
320 	}
321 
322 	if (len == 2)
323 		off = 2;
324 	else if (len == 4)
325 		off = 0;
326 	else if (len == 16)
327 		off = 0;
328 	else {
329 		rsp = BNEP_SETUP_INVALID_UUID_SIZE;
330 		goto done;
331 	}
332 
333 	if (memcmp(ptr, NAP_UUID + off, len) == 0)
334 		dst = SDP_SERVICE_CLASS_NAP;
335 	else if (memcmp(ptr, GN_UUID + off, len) == 0)
336 		dst = SDP_SERVICE_CLASS_GN;
337 	else if (memcmp(ptr, PANU_UUID + off, len) == 0)
338 		dst = SDP_SERVICE_CLASS_PANU;
339 	else
340 		dst = 0;
341 
342 	if (dst != service_class) {
343 		rsp = BNEP_SETUP_INVALID_DST_UUID;
344 		goto done;
345 	}
346 
347 	ptr += len;
348 
349 	if (memcmp(ptr, NAP_UUID + off, len) == 0)
350 		src = SDP_SERVICE_CLASS_NAP;
351 	else if (memcmp(ptr, GN_UUID + off, len) == 0)
352 		src = SDP_SERVICE_CLASS_GN;
353 	else if (memcmp(ptr, PANU_UUID + off, len) == 0)
354 		src = SDP_SERVICE_CLASS_PANU;
355 	else
356 		src = 0;
357 
358 	if ((dst != SDP_SERVICE_CLASS_PANU && src != SDP_SERVICE_CLASS_PANU)
359 	    || src == 0) {
360 		rsp = BNEP_SETUP_INVALID_SRC_UUID;
361 		goto done;
362 	}
363 
364 	rsp = BNEP_SETUP_SUCCESS;
365 	chan->state = CHANNEL_OPEN;
366 	channel_timeout(chan, 0);
367 
368 done:
369 	log_debug("addr %s response 0x%2.2x",
370 	    ether_ntoa((struct ether_addr *)chan->raddr), rsp);
371 
372 	bnep_send_control(chan, BNEP_SETUP_CONNECTION_RESPONSE, rsp);
373 	return (len * 2 + 1);
374 }
375 
376 static size_t
377 bnep_recv_setup_connection_rsp(channel_t *chan, uint8_t *ptr, size_t size)
378 {
379 	int rsp;
380 
381 	if (size < 2)
382 		return 0;
383 
384 	rsp = be16dec(ptr);
385 
386 	if (chan->state != CHANNEL_WAIT_CONNECT_RSP) {
387 		log_debug("ignored");
388 		return 2;
389 	}
390 
391 	log_debug("addr %s response 0x%2.2x",
392 	    ether_ntoa((struct ether_addr *)chan->raddr), rsp);
393 
394 	if (rsp == BNEP_SETUP_SUCCESS) {
395 		chan->state = CHANNEL_OPEN;
396 		channel_timeout(chan, 0);
397 	} else {
398 		channel_close(chan);
399 	}
400 
401 	return 2;
402 }
403 
404 static size_t
405 bnep_recv_filter_net_type_set(channel_t *chan, uint8_t *ptr, size_t size)
406 {
407 	pfilter_t *pf;
408 	int i, nf, rsp;
409 	size_t len;
410 
411 	if (size < 2)
412 		return 0;
413 
414 	len = be16dec(ptr);
415 	ptr += 2;
416 
417 	if (size < (len + 2))
418 		return 0;
419 
420 	if (chan->state != CHANNEL_OPEN) {
421 		log_debug("ignored");
422 		return (len + 2);
423 	}
424 
425 	nf = len / 4;
426 	pf = malloc(nf * sizeof(pfilter_t));
427 	if (pf == NULL) {
428 		rsp = BNEP_FILTER_TOO_MANY_FILTERS;
429 		goto done;
430 	}
431 
432 	log_debug("nf = %d", nf);
433 
434 	for (i = 0; i < nf; i++) {
435 		pf[i].start = be16dec(ptr);
436 		ptr += 2;
437 		pf[i].end = be16dec(ptr);
438 		ptr += 2;
439 
440 		if (pf[i].start > pf[i].end) {
441 			free(pf);
442 			rsp = BNEP_FILTER_INVALID_RANGE;
443 			goto done;
444 		}
445 
446 		log_debug("pf[%d] = %#4.4x, %#4.4x", i, pf[i].start, pf[i].end);
447 	}
448 
449 	if (chan->pfilter)
450 		free(chan->pfilter);
451 
452 	chan->pfilter = pf;
453 	chan->npfilter = nf;
454 
455 	rsp = BNEP_FILTER_SUCCESS;
456 
457 done:
458 	log_debug("addr %s response 0x%2.2x",
459 	    ether_ntoa((struct ether_addr *)chan->raddr), rsp);
460 
461 	bnep_send_control(chan, BNEP_FILTER_NET_TYPE_RESPONSE, rsp);
462 	return (len + 2);
463 }
464 
465 static size_t
466 bnep_recv_filter_net_type_rsp(channel_t *chan, uint8_t *ptr, size_t size)
467 {
468 	int rsp;
469 
470 	if (size < 2)
471 		return 0;
472 
473 	if (chan->state != CHANNEL_OPEN) {
474 		log_debug("ignored");
475 		return 2;
476 	}
477 
478 	rsp = be16dec(ptr);
479 
480 	log_debug("addr %s response 0x%2.2x",
481 	    ether_ntoa((struct ether_addr *)chan->raddr), rsp);
482 
483 	/* we did not send any filter_net_type_set message */
484 	return 2;
485 }
486 
487 static size_t
488 bnep_recv_filter_multi_addr_set(channel_t *chan, uint8_t *ptr, size_t size)
489 {
490 	mfilter_t *mf;
491 	int i, nf, rsp;
492 	size_t len;
493 
494 	if (size < 2)
495 		return 0;
496 
497 	len = be16dec(ptr);
498 	ptr += 2;
499 
500 	if (size < (len + 2))
501 		return 0;
502 
503 	if (chan->state != CHANNEL_OPEN) {
504 		log_debug("ignored");
505 		return (len + 2);
506 	}
507 
508 	nf = len / (ETHER_ADDR_LEN * 2);
509 	mf = malloc(nf * sizeof(mfilter_t));
510 	if (mf == NULL) {
511 		rsp = BNEP_FILTER_TOO_MANY_FILTERS;
512 		goto done;
513 	}
514 
515 	log_debug("nf = %d", nf);
516 
517 	for (i = 0; i < nf; i++) {
518 		memcpy(mf[i].start, ptr, ETHER_ADDR_LEN);
519 		ptr += ETHER_ADDR_LEN;
520 
521 		memcpy(mf[i].end, ptr, ETHER_ADDR_LEN);
522 		ptr += ETHER_ADDR_LEN;
523 
524 		if (memcmp(mf[i].start, mf[i].end, ETHER_ADDR_LEN) > 0) {
525 			free(mf);
526 			rsp = BNEP_FILTER_INVALID_RANGE;
527 			goto done;
528 		}
529 
530 		log_debug("pf[%d] = "
531 		    "%2.2x:%2.2x:%2.2x:%2.2x:%2.2x:%2.2x, "
532 		    "%2.2x:%2.2x:%2.2x:%2.2x:%2.2x:%2.2x", i,
533 		    mf[i].start[0], mf[i].start[1], mf[i].start[2],
534 		    mf[i].start[3], mf[i].start[4], mf[i].start[5],
535 		    mf[i].end[0], mf[i].end[1], mf[i].end[2],
536 		    mf[i].end[3], mf[i].end[4], mf[i].end[5]);
537 	}
538 
539 	if (chan->mfilter)
540 		free(chan->mfilter);
541 
542 	chan->mfilter = mf;
543 	chan->nmfilter = nf;
544 
545 	rsp = BNEP_FILTER_SUCCESS;
546 
547 done:
548 	log_debug("addr %s response 0x%2.2x",
549 	    ether_ntoa((struct ether_addr *)chan->raddr), rsp);
550 
551 	bnep_send_control(chan, BNEP_FILTER_MULTI_ADDR_RESPONSE, rsp);
552 	return (len + 2);
553 }
554 
555 static size_t
556 bnep_recv_filter_multi_addr_rsp(channel_t *chan, uint8_t *ptr, size_t size)
557 {
558 	int rsp;
559 
560 	if (size < 2)
561 		return false;
562 
563 	if (chan->state != CHANNEL_OPEN) {
564 		log_debug("ignored");
565 		return 2;
566 	}
567 
568 	rsp = be16dec(ptr);
569 	log_debug("addr %s response 0x%2.2x",
570 	    ether_ntoa((struct ether_addr *)chan->raddr), rsp);
571 
572 	/* we did not send any filter_multi_addr_set message */
573 	return 2;
574 }
575 
576 void
577 bnep_send_control(channel_t *chan, uint8_t type, ...)
578 {
579 	packet_t *pkt;
580 	uint8_t *p;
581 	va_list ap;
582 
583 	assert(chan->state != CHANNEL_CLOSED);
584 
585 	pkt = packet_alloc(chan);
586 	if (pkt == NULL)
587 		return;
588 
589 	p = pkt->ptr;
590 	va_start(ap, type);
591 
592 	*p++ = BNEP_CONTROL;
593 	*p++ = type;
594 
595 	switch(type) {
596 	case BNEP_CONTROL_COMMAND_NOT_UNDERSTOOD:
597 		*p++ = va_arg(ap, int);
598 		break;
599 
600 	case BNEP_SETUP_CONNECTION_REQUEST:
601 		*p++ = va_arg(ap, int);
602 		be16enc(p, va_arg(ap, int));
603 		p += 2;
604 		be16enc(p, va_arg(ap, int));
605 		p += 2;
606 		break;
607 
608 	case BNEP_SETUP_CONNECTION_RESPONSE:
609 	case BNEP_FILTER_NET_TYPE_RESPONSE:
610 	case BNEP_FILTER_MULTI_ADDR_RESPONSE:
611 		be16enc(p, va_arg(ap, int));
612 		p += 2;
613 		break;
614 
615 	case BNEP_FILTER_NET_TYPE_SET:		/* TODO */
616 	case BNEP_FILTER_MULTI_ADDR_SET:	/* TODO */
617 	default:
618 		log_err("Can't send control type 0x%2.2x", type);
619 		break;
620 	}
621 
622 	va_end(ap);
623 	pkt->len = p - pkt->ptr;
624 
625 	channel_put(chan, pkt);
626 	packet_free(pkt);
627 }
628 
629 /*
630  * BNEP send packet routine
631  * return true if packet can be removed from queue
632  */
633 bool
634 bnep_send(channel_t *chan, packet_t *pkt)
635 {
636 	struct iovec iov[2];
637 	uint8_t *p, *type, *proto;
638 	exthdr_t *eh;
639 	bool src, dst;
640 	size_t nw;
641 
642 	if (pkt->type == NULL) {
643 		iov[0].iov_base = pkt->ptr;
644 		iov[0].iov_len = pkt->len;
645 		iov[1].iov_base = NULL;
646 		iov[1].iov_len = 0;
647 	} else {
648 		p = chan->sendbuf;
649 
650 		dst = (memcmp(pkt->dst, chan->raddr, ETHER_ADDR_LEN) != 0);
651 		src = (memcmp(pkt->src, chan->laddr, ETHER_ADDR_LEN) != 0);
652 
653 		type = p;
654 		p += 1;
655 
656 		if (dst && src)
657 			*type = BNEP_GENERAL_ETHERNET;
658 		else if (dst && !src)
659 			*type = BNEP_COMPRESSED_ETHERNET_DST_ONLY;
660 		else if (!dst && src)
661 			*type = BNEP_COMPRESSED_ETHERNET_SRC_ONLY;
662 		else /* (!dst && !src) */
663 			*type = BNEP_COMPRESSED_ETHERNET;
664 
665 		if (dst) {
666 			memcpy(p, pkt->dst, ETHER_ADDR_LEN);
667 			p += ETHER_ADDR_LEN;
668 		}
669 
670 		if (src) {
671 			memcpy(p, pkt->src, ETHER_ADDR_LEN);
672 			p += ETHER_ADDR_LEN;
673 		}
674 
675 		proto = p;
676 		memcpy(p, pkt->type, ETHER_TYPE_LEN);
677 		p += ETHER_TYPE_LEN;
678 
679 		STAILQ_FOREACH(eh, &pkt->extlist, next) {
680 			if (p + eh->len > chan->sendbuf + chan->mtu)
681 				break;
682 
683 			*type |= BNEP_EXT;
684 			type = p;
685 
686 			memcpy(p, eh->ptr, eh->len);
687 			p += eh->len;
688 		}
689 
690 		*type &= ~BNEP_EXT;
691 
692 		iov[0].iov_base = chan->sendbuf;
693 		iov[0].iov_len = (p - chan->sendbuf);
694 
695 		if ((chan->npfilter == 0 || bnep_pfilter(chan, pkt))
696 		    && (chan->nmfilter == 0 || bnep_mfilter(chan, pkt))) {
697 			iov[1].iov_base = pkt->ptr;
698 			iov[1].iov_len = pkt->len;
699 		} else if (be16dec(proto) == ETHERTYPE_VLAN
700 		    && pkt->len >= ETHER_VLAN_ENCAP_LEN) {
701 			iov[1].iov_base = pkt->ptr;
702 			iov[1].iov_len = ETHER_VLAN_ENCAP_LEN;
703 		} else {
704 			iov[1].iov_base = NULL;
705 			iov[1].iov_len = 0;
706 			memset(proto, 0, ETHER_TYPE_LEN);
707 		}
708 	}
709 
710 	if (iov[0].iov_len + iov[1].iov_len > chan->mtu) {
711 		log_err("packet exceeded MTU (dropped)");
712 		return false;
713 	}
714 
715 	nw = writev(chan->fd, iov, __arraycount(iov));
716 	return (nw > 0);
717 }
718 
719 static bool
720 bnep_pfilter(channel_t *chan, packet_t *pkt)
721 {
722 	int proto, i;
723 
724 	proto = be16dec(pkt->type);
725 	if (proto == ETHERTYPE_VLAN) {	/* IEEE 802.1Q tag header */
726 		if (pkt->len < 4)
727 			return false;
728 
729 		proto = be16dec(pkt->ptr + 2);
730 	}
731 
732 	for (i = 0; i < chan->npfilter; i++) {
733 		if (chan->pfilter[i].start <= proto
734 		    && chan->pfilter[i].end >=proto)
735 			return true;
736 	}
737 
738 	return false;
739 }
740 
741 static bool
742 bnep_mfilter(channel_t *chan, packet_t *pkt)
743 {
744 	int i;
745 
746 	if (!ETHER_IS_MULTICAST(pkt->dst))
747 		return true;
748 
749 	for (i = 0; i < chan->nmfilter; i++) {
750 		if (memcmp(pkt->dst, chan->mfilter[i].start, ETHER_ADDR_LEN) >= 0
751 		    && memcmp(pkt->dst, chan->mfilter[i].end, ETHER_ADDR_LEN) <= 0)
752 			return true;
753 	}
754 
755 	return false;
756 }
757