xref: /linux/net/bluetooth/bnep/core.c (revision f8343685643f2901fe11aa9d0358cafbeaf7b4c3) 
1 /*
2    BNEP implementation for Linux Bluetooth stack (BlueZ).
3    Copyright (C) 2001-2002 Inventel Systemes
4    Written 2001-2002 by
5 	Cl�ment Moreau <clement.moreau@inventel.fr>
6 	David Libault  <david.libault@inventel.fr>
7 
8    Copyright (C) 2002 Maxim Krasnyansky <maxk@qualcomm.com>
9 
10    This program is free software; you can redistribute it and/or modify
11    it under the terms of the GNU General Public License version 2 as
12    published by the Free Software Foundation;
13 
14    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
15    OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
17    IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
18    CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
19    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
20    ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
21    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
22 
23    ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
24    COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
25    SOFTWARE IS DISCLAIMED.
26 */
27 
28 /*
29  * $Id: core.c,v 1.20 2002/08/04 21:23:58 maxk Exp $
30  */
31 
32 #include <linux/module.h>
33 
34 #include <linux/kernel.h>
35 #include <linux/sched.h>
36 #include <linux/signal.h>
37 #include <linux/init.h>
38 #include <linux/wait.h>
39 #include <linux/errno.h>
40 #include <linux/net.h>
41 #include <net/sock.h>
42 
43 #include <linux/socket.h>
44 #include <linux/file.h>
45 
46 #include <linux/netdevice.h>
47 #include <linux/etherdevice.h>
48 #include <linux/skbuff.h>
49 
50 #include <asm/unaligned.h>
51 
52 #include <net/bluetooth/bluetooth.h>
53 #include <net/bluetooth/hci_core.h>
54 #include <net/bluetooth/l2cap.h>
55 
56 #include "bnep.h"
57 
58 #ifndef CONFIG_BT_BNEP_DEBUG
59 #undef  BT_DBG
60 #define BT_DBG(D...)
61 #endif
62 
63 #define VERSION "1.2"
64 
65 static LIST_HEAD(bnep_session_list);
66 static DECLARE_RWSEM(bnep_session_sem);
67 
68 static struct bnep_session *__bnep_get_session(u8 *dst)
69 {
70 	struct bnep_session *s;
71 	struct list_head *p;
72 
73 	BT_DBG("");
74 
75 	list_for_each(p, &bnep_session_list) {
76 		s = list_entry(p, struct bnep_session, list);
77 		if (!compare_ether_addr(dst, s->eh.h_source))
78 			return s;
79 	}
80 	return NULL;
81 }
82 
83 static void __bnep_link_session(struct bnep_session *s)
84 {
85 	/* It's safe to call __module_get() here because sessions are added
86 	   by the socket layer which has to hold the refference to this module.
87 	 */
88 	__module_get(THIS_MODULE);
89 	list_add(&s->list, &bnep_session_list);
90 }
91 
92 static void __bnep_unlink_session(struct bnep_session *s)
93 {
94 	list_del(&s->list);
95 	module_put(THIS_MODULE);
96 }
97 
98 static int bnep_send(struct bnep_session *s, void *data, size_t len)
99 {
100 	struct socket *sock = s->sock;
101 	struct kvec iv = { data, len };
102 
103 	return kernel_sendmsg(sock, &s->msg, &iv, 1, len);
104 }
105 
106 static int bnep_send_rsp(struct bnep_session *s, u8 ctrl, u16 resp)
107 {
108 	struct bnep_control_rsp rsp;
109 	rsp.type = BNEP_CONTROL;
110 	rsp.ctrl = ctrl;
111 	rsp.resp = htons(resp);
112 	return bnep_send(s, &rsp, sizeof(rsp));
113 }
114 
115 #ifdef CONFIG_BT_BNEP_PROTO_FILTER
116 static inline void bnep_set_default_proto_filter(struct bnep_session *s)
117 {
118 	/* (IPv4, ARP)  */
119 	s->proto_filter[0].start = ETH_P_IP;
120 	s->proto_filter[0].end   = ETH_P_ARP;
121 	/* (RARP, AppleTalk) */
122 	s->proto_filter[1].start = ETH_P_RARP;
123 	s->proto_filter[1].end   = ETH_P_AARP;
124 	/* (IPX, IPv6) */
125 	s->proto_filter[2].start = ETH_P_IPX;
126 	s->proto_filter[2].end   = ETH_P_IPV6;
127 }
128 #endif
129 
130 static int bnep_ctrl_set_netfilter(struct bnep_session *s, __be16 *data, int len)
131 {
132 	int n;
133 
134 	if (len < 2)
135 		return -EILSEQ;
136 
137 	n = ntohs(get_unaligned(data));
138 	data++; len -= 2;
139 
140 	if (len < n)
141 		return -EILSEQ;
142 
143 	BT_DBG("filter len %d", n);
144 
145 #ifdef CONFIG_BT_BNEP_PROTO_FILTER
146 	n /= 4;
147 	if (n <= BNEP_MAX_PROTO_FILTERS) {
148 		struct bnep_proto_filter *f = s->proto_filter;
149 		int i;
150 
151 		for (i = 0; i < n; i++) {
152 			f[i].start = ntohs(get_unaligned(data++));
153 			f[i].end   = ntohs(get_unaligned(data++));
154 
155 			BT_DBG("proto filter start %d end %d",
156 				f[i].start, f[i].end);
157 		}
158 
159 		if (i < BNEP_MAX_PROTO_FILTERS)
160 			memset(f + i, 0, sizeof(*f));
161 
162 		if (n == 0)
163 			bnep_set_default_proto_filter(s);
164 
165 		bnep_send_rsp(s, BNEP_FILTER_NET_TYPE_RSP, BNEP_SUCCESS);
166 	} else {
167 		bnep_send_rsp(s, BNEP_FILTER_NET_TYPE_RSP, BNEP_FILTER_LIMIT_REACHED);
168 	}
169 #else
170 	bnep_send_rsp(s, BNEP_FILTER_NET_TYPE_RSP, BNEP_FILTER_UNSUPPORTED_REQ);
171 #endif
172 	return 0;
173 }
174 
175 static int bnep_ctrl_set_mcfilter(struct bnep_session *s, u8 *data, int len)
176 {
177 	int n;
178 
179 	if (len < 2)
180 		return -EILSEQ;
181 
182 	n = ntohs(get_unaligned((__be16 *) data));
183 	data += 2; len -= 2;
184 
185 	if (len < n)
186 		return -EILSEQ;
187 
188 	BT_DBG("filter len %d", n);
189 
190 #ifdef CONFIG_BT_BNEP_MC_FILTER
191 	n /= (ETH_ALEN * 2);
192 
193 	if (n > 0) {
194 		s->mc_filter = 0;
195 
196 		/* Always send broadcast */
197 		set_bit(bnep_mc_hash(s->dev->broadcast), (ulong *) &s->mc_filter);
198 
199 		/* Add address ranges to the multicast hash */
200 		for (; n > 0; n--) {
201 			u8 a1[6], *a2;
202 
203 			memcpy(a1, data, ETH_ALEN); data += ETH_ALEN;
204 			a2 = data; data += ETH_ALEN;
205 
206 			BT_DBG("mc filter %s -> %s",
207 				batostr((void *) a1), batostr((void *) a2));
208 
209 			#define INCA(a) { int i = 5; while (i >=0 && ++a[i--] == 0); }
210 
211 			/* Iterate from a1 to a2 */
212 			set_bit(bnep_mc_hash(a1), (ulong *) &s->mc_filter);
213 			while (memcmp(a1, a2, 6) < 0 && s->mc_filter != ~0LL) {
214 				INCA(a1);
215 				set_bit(bnep_mc_hash(a1), (ulong *) &s->mc_filter);
216 			}
217 		}
218 	}
219 
220 	BT_DBG("mc filter hash 0x%llx", s->mc_filter);
221 
222 	bnep_send_rsp(s, BNEP_FILTER_MULTI_ADDR_RSP, BNEP_SUCCESS);
223 #else
224 	bnep_send_rsp(s, BNEP_FILTER_MULTI_ADDR_RSP, BNEP_FILTER_UNSUPPORTED_REQ);
225 #endif
226 	return 0;
227 }
228 
229 static int bnep_rx_control(struct bnep_session *s, void *data, int len)
230 {
231 	u8  cmd = *(u8 *)data;
232 	int err = 0;
233 
234 	data++; len--;
235 
236 	switch (cmd) {
237 	case BNEP_CMD_NOT_UNDERSTOOD:
238 	case BNEP_SETUP_CONN_REQ:
239 	case BNEP_SETUP_CONN_RSP:
240 	case BNEP_FILTER_NET_TYPE_RSP:
241 	case BNEP_FILTER_MULTI_ADDR_RSP:
242 		/* Ignore these for now */
243 		break;
244 
245 	case BNEP_FILTER_NET_TYPE_SET:
246 		err = bnep_ctrl_set_netfilter(s, data, len);
247 		break;
248 
249 	case BNEP_FILTER_MULTI_ADDR_SET:
250 		err = bnep_ctrl_set_mcfilter(s, data, len);
251 		break;
252 
253 	default: {
254 			u8 pkt[3];
255 			pkt[0] = BNEP_CONTROL;
256 			pkt[1] = BNEP_CMD_NOT_UNDERSTOOD;
257 			pkt[2] = cmd;
258 			bnep_send(s, pkt, sizeof(pkt));
259 		}
260 		break;
261 	}
262 
263 	return err;
264 }
265 
266 static int bnep_rx_extension(struct bnep_session *s, struct sk_buff *skb)
267 {
268 	struct bnep_ext_hdr *h;
269 	int err = 0;
270 
271 	do {
272 		h = (void *) skb->data;
273 		if (!skb_pull(skb, sizeof(*h))) {
274 			err = -EILSEQ;
275 			break;
276 		}
277 
278 		BT_DBG("type 0x%x len %d", h->type, h->len);
279 
280 		switch (h->type & BNEP_TYPE_MASK) {
281 		case BNEP_EXT_CONTROL:
282 			bnep_rx_control(s, skb->data, skb->len);
283 			break;
284 
285 		default:
286 			/* Unknown extension, skip it. */
287 			break;
288 		}
289 
290 		if (!skb_pull(skb, h->len)) {
291 			err = -EILSEQ;
292 			break;
293 		}
294 	} while (!err && (h->type & BNEP_EXT_HEADER));
295 
296 	return err;
297 }
298 
299 static u8 __bnep_rx_hlen[] = {
300 	ETH_HLEN,     /* BNEP_GENERAL */
301 	0,            /* BNEP_CONTROL */
302 	2,            /* BNEP_COMPRESSED */
303 	ETH_ALEN + 2, /* BNEP_COMPRESSED_SRC_ONLY */
304 	ETH_ALEN + 2  /* BNEP_COMPRESSED_DST_ONLY */
305 };
306 #define BNEP_RX_TYPES	(sizeof(__bnep_rx_hlen) - 1)
307 
308 static inline int bnep_rx_frame(struct bnep_session *s, struct sk_buff *skb)
309 {
310 	struct net_device *dev = s->dev;
311 	struct sk_buff *nskb;
312 	u8 type;
313 
314 	dev->last_rx = jiffies;
315 	s->stats.rx_bytes += skb->len;
316 
317 	type = *(u8 *) skb->data; skb_pull(skb, 1);
318 
319 	if ((type & BNEP_TYPE_MASK) > BNEP_RX_TYPES)
320 		goto badframe;
321 
322 	if ((type & BNEP_TYPE_MASK) == BNEP_CONTROL) {
323 		bnep_rx_control(s, skb->data, skb->len);
324 		kfree_skb(skb);
325 		return 0;
326 	}
327 
328 	skb_reset_mac_header(skb);
329 
330 	/* Verify and pull out header */
331 	if (!skb_pull(skb, __bnep_rx_hlen[type & BNEP_TYPE_MASK]))
332 		goto badframe;
333 
334 	s->eh.h_proto = get_unaligned((__be16 *) (skb->data - 2));
335 
336 	if (type & BNEP_EXT_HEADER) {
337 		if (bnep_rx_extension(s, skb) < 0)
338 			goto badframe;
339 	}
340 
341 	/* Strip 802.1p header */
342 	if (ntohs(s->eh.h_proto) == 0x8100) {
343 		if (!skb_pull(skb, 4))
344 			goto badframe;
345 		s->eh.h_proto = get_unaligned((__be16 *) (skb->data - 2));
346 	}
347 
348 	/* We have to alloc new skb and copy data here :(. Because original skb
349 	 * may not be modified and because of the alignment requirements. */
350 	nskb = alloc_skb(2 + ETH_HLEN + skb->len, GFP_KERNEL);
351 	if (!nskb) {
352 		s->stats.rx_dropped++;
353 		kfree_skb(skb);
354 		return -ENOMEM;
355 	}
356 	skb_reserve(nskb, 2);
357 
358 	/* Decompress header and construct ether frame */
359 	switch (type & BNEP_TYPE_MASK) {
360 	case BNEP_COMPRESSED:
361 		memcpy(__skb_put(nskb, ETH_HLEN), &s->eh, ETH_HLEN);
362 		break;
363 
364 	case BNEP_COMPRESSED_SRC_ONLY:
365 		memcpy(__skb_put(nskb, ETH_ALEN), s->eh.h_dest, ETH_ALEN);
366 		memcpy(__skb_put(nskb, ETH_ALEN), skb_mac_header(skb), ETH_ALEN);
367 		put_unaligned(s->eh.h_proto, (__be16 *) __skb_put(nskb, 2));
368 		break;
369 
370 	case BNEP_COMPRESSED_DST_ONLY:
371 		memcpy(__skb_put(nskb, ETH_ALEN), skb_mac_header(skb),
372 		       ETH_ALEN);
373 		memcpy(__skb_put(nskb, ETH_ALEN + 2), s->eh.h_source,
374 		       ETH_ALEN + 2);
375 		break;
376 
377 	case BNEP_GENERAL:
378 		memcpy(__skb_put(nskb, ETH_ALEN * 2), skb_mac_header(skb),
379 		       ETH_ALEN * 2);
380 		put_unaligned(s->eh.h_proto, (__be16 *) __skb_put(nskb, 2));
381 		break;
382 	}
383 
384 	skb_copy_from_linear_data(skb, __skb_put(nskb, skb->len), skb->len);
385 	kfree_skb(skb);
386 
387 	s->stats.rx_packets++;
388 	nskb->ip_summed = CHECKSUM_NONE;
389 	nskb->protocol  = eth_type_trans(nskb, dev);
390 	netif_rx_ni(nskb);
391 	return 0;
392 
393 badframe:
394 	s->stats.rx_errors++;
395 	kfree_skb(skb);
396 	return 0;
397 }
398 
399 static u8 __bnep_tx_types[] = {
400 	BNEP_GENERAL,
401 	BNEP_COMPRESSED_SRC_ONLY,
402 	BNEP_COMPRESSED_DST_ONLY,
403 	BNEP_COMPRESSED
404 };
405 
406 static inline int bnep_tx_frame(struct bnep_session *s, struct sk_buff *skb)
407 {
408 	struct ethhdr *eh = (void *) skb->data;
409 	struct socket *sock = s->sock;
410 	struct kvec iv[3];
411 	int len = 0, il = 0;
412 	u8 type = 0;
413 
414 	BT_DBG("skb %p dev %p type %d", skb, skb->dev, skb->pkt_type);
415 
416 	if (!skb->dev) {
417 		/* Control frame sent by us */
418 		goto send;
419 	}
420 
421 	iv[il++] = (struct kvec) { &type, 1 };
422 	len++;
423 
424 	if (!compare_ether_addr(eh->h_dest, s->eh.h_source))
425 		type |= 0x01;
426 
427 	if (!compare_ether_addr(eh->h_source, s->eh.h_dest))
428 		type |= 0x02;
429 
430 	if (type)
431 		skb_pull(skb, ETH_ALEN * 2);
432 
433 	type = __bnep_tx_types[type];
434 	switch (type) {
435 	case BNEP_COMPRESSED_SRC_ONLY:
436 		iv[il++] = (struct kvec) { eh->h_source, ETH_ALEN };
437 		len += ETH_ALEN;
438 		break;
439 
440 	case BNEP_COMPRESSED_DST_ONLY:
441 		iv[il++] = (struct kvec) { eh->h_dest, ETH_ALEN };
442 		len += ETH_ALEN;
443 		break;
444 	}
445 
446 send:
447 	iv[il++] = (struct kvec) { skb->data, skb->len };
448 	len += skb->len;
449 
450 	/* FIXME: linearize skb */
451 	{
452 		len = kernel_sendmsg(sock, &s->msg, iv, il, len);
453 	}
454 	kfree_skb(skb);
455 
456 	if (len > 0) {
457 		s->stats.tx_bytes += len;
458 		s->stats.tx_packets++;
459 		return 0;
460 	}
461 
462 	return len;
463 }
464 
465 static int bnep_session(void *arg)
466 {
467 	struct bnep_session *s = arg;
468 	struct net_device *dev = s->dev;
469 	struct sock *sk = s->sock->sk;
470 	struct sk_buff *skb;
471 	wait_queue_t wait;
472 
473 	BT_DBG("");
474 
475 	daemonize("kbnepd %s", dev->name);
476 	set_user_nice(current, -15);
477 	current->flags |= PF_NOFREEZE;
478 
479 	init_waitqueue_entry(&wait, current);
480 	add_wait_queue(sk->sk_sleep, &wait);
481 	while (!atomic_read(&s->killed)) {
482 		set_current_state(TASK_INTERRUPTIBLE);
483 
484 		// RX
485 		while ((skb = skb_dequeue(&sk->sk_receive_queue))) {
486 			skb_orphan(skb);
487 			bnep_rx_frame(s, skb);
488 		}
489 
490 		if (sk->sk_state != BT_CONNECTED)
491 			break;
492 
493 		// TX
494 		while ((skb = skb_dequeue(&sk->sk_write_queue)))
495 			if (bnep_tx_frame(s, skb))
496 				break;
497 		netif_wake_queue(dev);
498 
499 		schedule();
500 	}
501 	set_current_state(TASK_RUNNING);
502 	remove_wait_queue(sk->sk_sleep, &wait);
503 
504 	/* Cleanup session */
505 	down_write(&bnep_session_sem);
506 
507 	/* Delete network device */
508 	unregister_netdev(dev);
509 
510 	/* Release the socket */
511 	fput(s->sock->file);
512 
513 	__bnep_unlink_session(s);
514 
515 	up_write(&bnep_session_sem);
516 	free_netdev(dev);
517 	return 0;
518 }
519 
520 static struct device *bnep_get_device(struct bnep_session *session)
521 {
522 	bdaddr_t *src = &bt_sk(session->sock->sk)->src;
523 	bdaddr_t *dst = &bt_sk(session->sock->sk)->dst;
524 	struct hci_dev *hdev;
525 	struct hci_conn *conn;
526 
527 	hdev = hci_get_route(dst, src);
528 	if (!hdev)
529 		return NULL;
530 
531 	conn = hci_conn_hash_lookup_ba(hdev, ACL_LINK, dst);
532 
533 	hci_dev_put(hdev);
534 
535 	return conn ? &conn->dev : NULL;
536 }
537 
538 int bnep_add_connection(struct bnep_connadd_req *req, struct socket *sock)
539 {
540 	struct net_device *dev;
541 	struct bnep_session *s, *ss;
542 	u8 dst[ETH_ALEN], src[ETH_ALEN];
543 	int err;
544 
545 	BT_DBG("");
546 
547 	baswap((void *) dst, &bt_sk(sock->sk)->dst);
548 	baswap((void *) src, &bt_sk(sock->sk)->src);
549 
550 	/* session struct allocated as private part of net_device */
551 	dev = alloc_netdev(sizeof(struct bnep_session),
552 			   (*req->device) ? req->device : "bnep%d",
553 			   bnep_net_setup);
554 	if (!dev)
555 		return -ENOMEM;
556 
557 	down_write(&bnep_session_sem);
558 
559 	ss = __bnep_get_session(dst);
560 	if (ss && ss->state == BT_CONNECTED) {
561 		err = -EEXIST;
562 		goto failed;
563 	}
564 
565 	s = dev->priv;
566 
567 	/* This is rx header therefore addresses are swapped.
568 	 * ie eh.h_dest is our local address. */
569 	memcpy(s->eh.h_dest,   &src, ETH_ALEN);
570 	memcpy(s->eh.h_source, &dst, ETH_ALEN);
571 	memcpy(dev->dev_addr, s->eh.h_dest, ETH_ALEN);
572 
573 	s->dev   = dev;
574 	s->sock  = sock;
575 	s->role  = req->role;
576 	s->state = BT_CONNECTED;
577 
578 	s->msg.msg_flags = MSG_NOSIGNAL;
579 
580 #ifdef CONFIG_BT_BNEP_MC_FILTER
581 	/* Set default mc filter */
582 	set_bit(bnep_mc_hash(dev->broadcast), (ulong *) &s->mc_filter);
583 #endif
584 
585 #ifdef CONFIG_BT_BNEP_PROTO_FILTER
586 	/* Set default protocol filter */
587 	bnep_set_default_proto_filter(s);
588 #endif
589 
590 	SET_NETDEV_DEV(dev, bnep_get_device(s));
591 
592 	err = register_netdev(dev);
593 	if (err) {
594 		goto failed;
595 	}
596 
597 	__bnep_link_session(s);
598 
599 	err = kernel_thread(bnep_session, s, CLONE_KERNEL);
600 	if (err < 0) {
601 		/* Session thread start failed, gotta cleanup. */
602 		unregister_netdev(dev);
603 		__bnep_unlink_session(s);
604 		goto failed;
605 	}
606 
607 	up_write(&bnep_session_sem);
608 	strcpy(req->device, dev->name);
609 	return 0;
610 
611 failed:
612 	up_write(&bnep_session_sem);
613 	free_netdev(dev);
614 	return err;
615 }
616 
617 int bnep_del_connection(struct bnep_conndel_req *req)
618 {
619 	struct bnep_session *s;
620 	int  err = 0;
621 
622 	BT_DBG("");
623 
624 	down_read(&bnep_session_sem);
625 
626 	s = __bnep_get_session(req->dst);
627 	if (s) {
628 		/* Wakeup user-space which is polling for socket errors.
629 		 * This is temporary hack untill we have shutdown in L2CAP */
630 		s->sock->sk->sk_err = EUNATCH;
631 
632 		/* Kill session thread */
633 		atomic_inc(&s->killed);
634 		wake_up_interruptible(s->sock->sk->sk_sleep);
635 	} else
636 		err = -ENOENT;
637 
638 	up_read(&bnep_session_sem);
639 	return err;
640 }
641 
642 static void __bnep_copy_ci(struct bnep_conninfo *ci, struct bnep_session *s)
643 {
644 	memcpy(ci->dst, s->eh.h_source, ETH_ALEN);
645 	strcpy(ci->device, s->dev->name);
646 	ci->flags = s->flags;
647 	ci->state = s->state;
648 	ci->role  = s->role;
649 }
650 
651 int bnep_get_connlist(struct bnep_connlist_req *req)
652 {
653 	struct list_head *p;
654 	int err = 0, n = 0;
655 
656 	down_read(&bnep_session_sem);
657 
658 	list_for_each(p, &bnep_session_list) {
659 		struct bnep_session *s;
660 		struct bnep_conninfo ci;
661 
662 		s = list_entry(p, struct bnep_session, list);
663 
664 		__bnep_copy_ci(&ci, s);
665 
666 		if (copy_to_user(req->ci, &ci, sizeof(ci))) {
667 			err = -EFAULT;
668 			break;
669 		}
670 
671 		if (++n >= req->cnum)
672 			break;
673 
674 		req->ci++;
675 	}
676 	req->cnum = n;
677 
678 	up_read(&bnep_session_sem);
679 	return err;
680 }
681 
682 int bnep_get_conninfo(struct bnep_conninfo *ci)
683 {
684 	struct bnep_session *s;
685 	int err = 0;
686 
687 	down_read(&bnep_session_sem);
688 
689 	s = __bnep_get_session(ci->dst);
690 	if (s)
691 		__bnep_copy_ci(ci, s);
692 	else
693 		err = -ENOENT;
694 
695 	up_read(&bnep_session_sem);
696 	return err;
697 }
698 
699 static int __init bnep_init(void)
700 {
701 	char flt[50] = "";
702 
703 	l2cap_load();
704 
705 #ifdef CONFIG_BT_BNEP_PROTO_FILTER
706 	strcat(flt, "protocol ");
707 #endif
708 
709 #ifdef CONFIG_BT_BNEP_MC_FILTER
710 	strcat(flt, "multicast");
711 #endif
712 
713 	BT_INFO("BNEP (Ethernet Emulation) ver %s", VERSION);
714 	if (flt[0])
715 		BT_INFO("BNEP filters: %s", flt);
716 
717 	bnep_sock_init();
718 	return 0;
719 }
720 
721 static void __exit bnep_exit(void)
722 {
723 	bnep_sock_cleanup();
724 }
725 
726 module_init(bnep_init);
727 module_exit(bnep_exit);
728 
729 MODULE_AUTHOR("David Libault <david.libault@inventel.fr>, Maxim Krasnyansky <maxk@qualcomm.com>");
730 MODULE_DESCRIPTION("Bluetooth BNEP ver " VERSION);
731 MODULE_VERSION(VERSION);
732 MODULE_LICENSE("GPL");
733 MODULE_ALIAS("bt-proto-4");
734