xref: /linux/net/bluetooth/bnep/core.c (revision fafb66e5903c2bcfc7b7e259042a8282f18a6faa) 
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3    BNEP implementation for Linux Bluetooth stack (BlueZ).
4    Copyright (C) 2001-2002 Inventel Systemes
5    Written 2001-2002 by
6 	Clément Moreau <clement.moreau@inventel.fr>
7 	David Libault  <david.libault@inventel.fr>
8 
9    Copyright (C) 2002 Maxim Krasnyansky <maxk@qualcomm.com>
10 
11    THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
12    OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
13    FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
14    IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) AND AUTHOR(S) BE LIABLE FOR ANY
15    CLAIM, OR ANY SPECIAL INDIRECT OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES
16    WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
17    ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
18    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
19 
20    ALL LIABILITY, INCLUDING LIABILITY FOR INFRINGEMENT OF ANY PATENTS,
21    COPYRIGHTS, TRADEMARKS OR OTHER RIGHTS, RELATING TO USE OF THIS
22    SOFTWARE IS DISCLAIMED.
23 */
24 
25 #include <linux/module.h>
26 #include <linux/kthread.h>
27 #include <linux/file.h>
28 #include <linux/etherdevice.h>
29 #include <linux/unaligned.h>
30 
31 #include <net/bluetooth/bluetooth.h>
32 #include <net/bluetooth/l2cap.h>
33 #include <net/bluetooth/hci_core.h>
34 
35 #include "bnep.h"
36 
37 #define VERSION "1.3"
38 
39 static bool compress_src = true;
40 static bool compress_dst = true;
41 
42 static LIST_HEAD(bnep_session_list);
43 static DECLARE_RWSEM(bnep_session_sem);
44 
45 static struct bnep_session *__bnep_get_session(u8 *dst)
46 {
47 	struct bnep_session *s;
48 
49 	BT_DBG("");
50 
51 	list_for_each_entry(s, &bnep_session_list, list)
52 		if (ether_addr_equal(dst, s->eh.h_source))
53 			return s;
54 
55 	return NULL;
56 }
57 
58 static void __bnep_link_session(struct bnep_session *s)
59 {
60 	list_add(&s->list, &bnep_session_list);
61 }
62 
63 static void __bnep_unlink_session(struct bnep_session *s)
64 {
65 	list_del(&s->list);
66 }
67 
68 static int bnep_send(struct bnep_session *s, void *data, size_t len)
69 {
70 	struct socket *sock = s->sock;
71 	struct kvec iv = { data, len };
72 
73 	return kernel_sendmsg(sock, &s->msg, &iv, 1, len);
74 }
75 
76 static int bnep_send_rsp(struct bnep_session *s, u8 ctrl, u16 resp)
77 {
78 	struct bnep_control_rsp rsp;
79 	rsp.type = BNEP_CONTROL;
80 	rsp.ctrl = ctrl;
81 	rsp.resp = htons(resp);
82 	return bnep_send(s, &rsp, sizeof(rsp));
83 }
84 
85 #ifdef CONFIG_BT_BNEP_PROTO_FILTER
86 static inline void bnep_set_default_proto_filter(struct bnep_session *s)
87 {
88 	/* (IPv4, ARP)  */
89 	s->proto_filter[0].start = ETH_P_IP;
90 	s->proto_filter[0].end   = ETH_P_ARP;
91 	/* (RARP, AppleTalk) */
92 	s->proto_filter[1].start = ETH_P_RARP;
93 	s->proto_filter[1].end   = ETH_P_AARP;
94 	/* (IPX, IPv6) */
95 	s->proto_filter[2].start = ETH_P_IPX;
96 	s->proto_filter[2].end   = ETH_P_IPV6;
97 }
98 #endif
99 
100 static int bnep_ctrl_set_netfilter(struct bnep_session *s, __be16 *data, int len)
101 {
102 	int n;
103 
104 	if (len < 2)
105 		return -EILSEQ;
106 
107 	n = get_unaligned_be16(data);
108 	data++;
109 	len -= 2;
110 
111 	if (len < n)
112 		return -EILSEQ;
113 
114 	BT_DBG("filter len %d", n);
115 
116 #ifdef CONFIG_BT_BNEP_PROTO_FILTER
117 	n /= 4;
118 	if (n <= BNEP_MAX_PROTO_FILTERS) {
119 		struct bnep_proto_filter *f = s->proto_filter;
120 		int i;
121 
122 		for (i = 0; i < n; i++) {
123 			f[i].start = get_unaligned_be16(data++);
124 			f[i].end   = get_unaligned_be16(data++);
125 
126 			BT_DBG("proto filter start %u end %u",
127 			       f[i].start, f[i].end);
128 		}
129 
130 		if (i < BNEP_MAX_PROTO_FILTERS)
131 			memset(f + i, 0, sizeof(*f));
132 
133 		if (n == 0)
134 			bnep_set_default_proto_filter(s);
135 
136 		bnep_send_rsp(s, BNEP_FILTER_NET_TYPE_RSP, BNEP_SUCCESS);
137 	} else {
138 		bnep_send_rsp(s, BNEP_FILTER_NET_TYPE_RSP, BNEP_FILTER_LIMIT_REACHED);
139 	}
140 #else
141 	bnep_send_rsp(s, BNEP_FILTER_NET_TYPE_RSP, BNEP_FILTER_UNSUPPORTED_REQ);
142 #endif
143 	return 0;
144 }
145 
146 static int bnep_ctrl_set_mcfilter(struct bnep_session *s, u8 *data, int len)
147 {
148 	int n;
149 
150 	if (len < 2)
151 		return -EILSEQ;
152 
153 	n = get_unaligned_be16(data);
154 	data += 2;
155 	len -= 2;
156 
157 	if (len < n)
158 		return -EILSEQ;
159 
160 	BT_DBG("filter len %d", n);
161 
162 #ifdef CONFIG_BT_BNEP_MC_FILTER
163 	n /= (ETH_ALEN * 2);
164 
165 	if (n > 0) {
166 		int i;
167 
168 		s->mc_filter = 0;
169 
170 		/* Always send broadcast */
171 		set_bit(bnep_mc_hash(s->dev->broadcast), (ulong *) &s->mc_filter);
172 
173 		/* Add address ranges to the multicast hash */
174 		for (; n > 0; n--) {
175 			u8 a1[6], *a2;
176 
177 			memcpy(a1, data, ETH_ALEN);
178 			data += ETH_ALEN;
179 			a2 = data;
180 			data += ETH_ALEN;
181 
182 			BT_DBG("mc filter %pMR -> %pMR", a1, a2);
183 
184 			/* Iterate from a1 to a2 */
185 			set_bit(bnep_mc_hash(a1), (ulong *) &s->mc_filter);
186 			while (memcmp(a1, a2, 6) < 0 && s->mc_filter != ~0LL) {
187 				/* Increment a1 */
188 				i = 5;
189 				while (i >= 0 && ++a1[i--] == 0)
190 					;
191 
192 				set_bit(bnep_mc_hash(a1), (ulong *) &s->mc_filter);
193 			}
194 		}
195 	}
196 
197 	BT_DBG("mc filter hash 0x%llx", s->mc_filter);
198 
199 	bnep_send_rsp(s, BNEP_FILTER_MULTI_ADDR_RSP, BNEP_SUCCESS);
200 #else
201 	bnep_send_rsp(s, BNEP_FILTER_MULTI_ADDR_RSP, BNEP_FILTER_UNSUPPORTED_REQ);
202 #endif
203 	return 0;
204 }
205 
206 static int bnep_rx_control_cmd(struct bnep_session *s, u8 cmd, void *data,
207 			       int len)
208 {
209 	int err = 0;
210 
211 	switch (cmd) {
212 	case BNEP_CMD_NOT_UNDERSTOOD:
213 	case BNEP_SETUP_CONN_RSP:
214 	case BNEP_FILTER_NET_TYPE_RSP:
215 	case BNEP_FILTER_MULTI_ADDR_RSP:
216 		/* Ignore these for now */
217 		break;
218 
219 	case BNEP_FILTER_NET_TYPE_SET:
220 		err = bnep_ctrl_set_netfilter(s, data, len);
221 		break;
222 
223 	case BNEP_FILTER_MULTI_ADDR_SET:
224 		err = bnep_ctrl_set_mcfilter(s, data, len);
225 		break;
226 
227 	case BNEP_SETUP_CONN_REQ:
228 		/* Successful response should be sent only once */
229 		if (test_bit(BNEP_SETUP_RESPONSE, &s->flags) &&
230 		    !test_and_set_bit(BNEP_SETUP_RSP_SENT, &s->flags))
231 			err = bnep_send_rsp(s, BNEP_SETUP_CONN_RSP,
232 					    BNEP_SUCCESS);
233 		else
234 			err = bnep_send_rsp(s, BNEP_SETUP_CONN_RSP,
235 					    BNEP_CONN_NOT_ALLOWED);
236 		break;
237 
238 	default: {
239 			u8 pkt[3];
240 			pkt[0] = BNEP_CONTROL;
241 			pkt[1] = BNEP_CMD_NOT_UNDERSTOOD;
242 			pkt[2] = cmd;
243 			err = bnep_send(s, pkt, sizeof(pkt));
244 		}
245 		break;
246 	}
247 
248 	return err;
249 }
250 
251 static int bnep_rx_control(struct bnep_session *s, void *data, int len)
252 {
253 	if (len < 1)
254 		return -EILSEQ;
255 
256 	return bnep_rx_control_cmd(s, *(u8 *)data, data + 1, len - 1);
257 }
258 
259 static int bnep_rx_extension(struct bnep_session *s, struct sk_buff *skb)
260 {
261 	struct bnep_ext_hdr *h;
262 	int err = 0;
263 
264 	do {
265 		h = (void *) skb->data;
266 		if (!skb_pull(skb, sizeof(*h))) {
267 			err = -EILSEQ;
268 			break;
269 		}
270 
271 		BT_DBG("type 0x%x len %u", h->type, h->len);
272 
273 		switch (h->type & BNEP_TYPE_MASK) {
274 		case BNEP_EXT_CONTROL:
275 			bnep_rx_control(s, skb->data, skb->len);
276 			break;
277 
278 		default:
279 			/* Unknown extension, skip it. */
280 			break;
281 		}
282 
283 		if (!skb_pull(skb, h->len)) {
284 			err = -EILSEQ;
285 			break;
286 		}
287 	} while (!err && (h->type & BNEP_EXT_HEADER));
288 
289 	return err;
290 }
291 
292 static u8 __bnep_rx_hlen[] = {
293 	ETH_HLEN,     /* BNEP_GENERAL */
294 	0,            /* BNEP_CONTROL */
295 	2,            /* BNEP_COMPRESSED */
296 	ETH_ALEN + 2, /* BNEP_COMPRESSED_SRC_ONLY */
297 	ETH_ALEN + 2  /* BNEP_COMPRESSED_DST_ONLY */
298 };
299 
300 static int bnep_rx_frame(struct bnep_session *s, struct sk_buff *skb)
301 {
302 	struct net_device *dev = s->dev;
303 	struct sk_buff *nskb;
304 	u8 *data;
305 	u8 type, ctrl_type;
306 
307 	dev->stats.rx_bytes += skb->len;
308 
309 	data = skb_pull_data(skb, sizeof(type));
310 	if (!data)
311 		goto badframe;
312 	type = *data;
313 
314 	if ((type & BNEP_TYPE_MASK) >= sizeof(__bnep_rx_hlen))
315 		goto badframe;
316 
317 	if ((type & BNEP_TYPE_MASK) == BNEP_CONTROL) {
318 		data = skb_pull_data(skb, sizeof(ctrl_type));
319 		if (!data)
320 			goto badframe;
321 		ctrl_type = *data;
322 
323 		if (bnep_rx_control_cmd(s, ctrl_type, skb->data, skb->len) < 0) {
324 			dev->stats.tx_errors++;
325 			kfree_skb(skb);
326 			return 0;
327 		}
328 
329 		if (!(type & BNEP_EXT_HEADER)) {
330 			kfree_skb(skb);
331 			return 0;
332 		}
333 
334 		/* Verify and pull ctrl message since it's already processed */
335 		switch (ctrl_type) {
336 		case BNEP_SETUP_CONN_REQ: {
337 			u8 uuid_size;
338 
339 			/* Pull uuid_size and the dst/src service UUIDs. */
340 			data = skb_pull_data(skb, sizeof(uuid_size));
341 			if (!data)
342 				goto badframe;
343 			uuid_size = *data;
344 			if (!skb_pull(skb, uuid_size + uuid_size))
345 				goto badframe;
346 			break;
347 		}
348 		case BNEP_FILTER_MULTI_ADDR_SET:
349 		case BNEP_FILTER_NET_TYPE_SET:
350 			/* Pull: len (2 b), data (len bytes) */
351 			data = skb_pull_data(skb, sizeof(u16));
352 			if (!data)
353 				goto badframe;
354 			if (!skb_pull(skb, get_unaligned_be16(data)))
355 				goto badframe;
356 			break;
357 		default:
358 			kfree_skb(skb);
359 			return 0;
360 		}
361 	} else {
362 		skb_reset_mac_header(skb);
363 
364 		/* Verify and pull out header */
365 		if (!skb_pull(skb, __bnep_rx_hlen[type & BNEP_TYPE_MASK]))
366 			goto badframe;
367 
368 		s->eh.h_proto = get_unaligned((__be16 *) (skb->data - 2));
369 	}
370 
371 	if (type & BNEP_EXT_HEADER) {
372 		if (bnep_rx_extension(s, skb) < 0)
373 			goto badframe;
374 	}
375 
376 	/* Strip 802.1p header */
377 	if (ntohs(s->eh.h_proto) == ETH_P_8021Q) {
378 		if (!skb_pull(skb, 4))
379 			goto badframe;
380 		s->eh.h_proto = get_unaligned((__be16 *) (skb->data - 2));
381 	}
382 
383 	/* We have to alloc new skb and copy data here :(. Because original skb
384 	 * may not be modified and because of the alignment requirements. */
385 	nskb = alloc_skb(2 + ETH_HLEN + skb->len, GFP_KERNEL);
386 	if (!nskb) {
387 		dev->stats.rx_dropped++;
388 		kfree_skb(skb);
389 		return -ENOMEM;
390 	}
391 	skb_reserve(nskb, 2);
392 
393 	/* Decompress header and construct ether frame */
394 	switch (type & BNEP_TYPE_MASK) {
395 	case BNEP_COMPRESSED:
396 		__skb_put_data(nskb, &s->eh, ETH_HLEN);
397 		break;
398 
399 	case BNEP_COMPRESSED_SRC_ONLY:
400 		__skb_put_data(nskb, s->eh.h_dest, ETH_ALEN);
401 		__skb_put_data(nskb, skb_mac_header(skb), ETH_ALEN);
402 		put_unaligned(s->eh.h_proto, (__be16 *) __skb_put(nskb, 2));
403 		break;
404 
405 	case BNEP_COMPRESSED_DST_ONLY:
406 		__skb_put_data(nskb, skb_mac_header(skb), ETH_ALEN);
407 		__skb_put_data(nskb, s->eh.h_source, ETH_ALEN);
408 		put_unaligned(s->eh.h_proto, (__be16 *)__skb_put(nskb, 2));
409 		break;
410 
411 	case BNEP_GENERAL:
412 		__skb_put_data(nskb, skb_mac_header(skb), ETH_ALEN * 2);
413 		put_unaligned(s->eh.h_proto, (__be16 *) __skb_put(nskb, 2));
414 		break;
415 	}
416 
417 	skb_copy_from_linear_data(skb, __skb_put(nskb, skb->len), skb->len);
418 	kfree_skb(skb);
419 
420 	dev->stats.rx_packets++;
421 	nskb->ip_summed = CHECKSUM_NONE;
422 	nskb->protocol  = eth_type_trans(nskb, dev);
423 	netif_rx(nskb);
424 	return 0;
425 
426 badframe:
427 	dev->stats.rx_errors++;
428 	kfree_skb(skb);
429 	return 0;
430 }
431 
432 static u8 __bnep_tx_types[] = {
433 	BNEP_GENERAL,
434 	BNEP_COMPRESSED_SRC_ONLY,
435 	BNEP_COMPRESSED_DST_ONLY,
436 	BNEP_COMPRESSED
437 };
438 
439 static int bnep_tx_frame(struct bnep_session *s, struct sk_buff *skb)
440 {
441 	struct ethhdr *eh = (void *) skb->data;
442 	struct socket *sock = s->sock;
443 	struct kvec iv[3];
444 	int len = 0, il = 0;
445 	u8 type = 0;
446 
447 	BT_DBG("skb %p dev %p type %u", skb, skb->dev, skb->pkt_type);
448 
449 	if (!skb->dev) {
450 		/* Control frame sent by us */
451 		goto send;
452 	}
453 
454 	iv[il++] = (struct kvec) { &type, 1 };
455 	len++;
456 
457 	if (compress_src && ether_addr_equal(eh->h_dest, s->eh.h_source))
458 		type |= 0x01;
459 
460 	if (compress_dst && ether_addr_equal(eh->h_source, s->eh.h_dest))
461 		type |= 0x02;
462 
463 	if (type)
464 		skb_pull(skb, ETH_ALEN * 2);
465 
466 	type = __bnep_tx_types[type];
467 	switch (type) {
468 	case BNEP_COMPRESSED_SRC_ONLY:
469 		iv[il++] = (struct kvec) { eh->h_source, ETH_ALEN };
470 		len += ETH_ALEN;
471 		break;
472 
473 	case BNEP_COMPRESSED_DST_ONLY:
474 		iv[il++] = (struct kvec) { eh->h_dest, ETH_ALEN };
475 		len += ETH_ALEN;
476 		break;
477 	}
478 
479 send:
480 	iv[il++] = (struct kvec) { skb->data, skb->len };
481 	len += skb->len;
482 
483 	/* FIXME: linearize skb */
484 	{
485 		len = kernel_sendmsg(sock, &s->msg, iv, il, len);
486 	}
487 	kfree_skb(skb);
488 
489 	if (len > 0) {
490 		s->dev->stats.tx_bytes += len;
491 		s->dev->stats.tx_packets++;
492 		return 0;
493 	}
494 
495 	return len;
496 }
497 
498 static int bnep_session(void *arg)
499 {
500 	struct bnep_session *s = arg;
501 	struct net_device *dev = s->dev;
502 	struct sock *sk = s->sock->sk;
503 	struct sk_buff *skb;
504 	DEFINE_WAIT_FUNC(wait, woken_wake_function);
505 
506 	BT_DBG("");
507 
508 	set_user_nice(current, -15);
509 
510 	add_wait_queue(sk_sleep(sk), &wait);
511 	while (1) {
512 		if (atomic_read(&s->terminate))
513 			break;
514 		/* RX */
515 		while ((skb = skb_dequeue(&sk->sk_receive_queue))) {
516 			skb_orphan(skb);
517 			if (!skb_linearize(skb))
518 				bnep_rx_frame(s, skb);
519 			else
520 				kfree_skb(skb);
521 		}
522 
523 		if (sk->sk_state != BT_CONNECTED)
524 			break;
525 
526 		/* TX */
527 		while ((skb = skb_dequeue(&sk->sk_write_queue)))
528 			if (bnep_tx_frame(s, skb))
529 				break;
530 		netif_wake_queue(dev);
531 
532 		/*
533 		 * wait_woken() performs the necessary memory barriers
534 		 * for us; see the header comment for this primitive.
535 		 */
536 		wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
537 	}
538 	remove_wait_queue(sk_sleep(sk), &wait);
539 
540 	/* Cleanup session */
541 	down_write(&bnep_session_sem);
542 
543 	/* Delete network device */
544 	unregister_netdev(dev);
545 
546 	/* Wakeup user-space polling for socket errors */
547 	s->sock->sk->sk_err = EUNATCH;
548 
549 	wake_up_interruptible(sk_sleep(s->sock->sk));
550 
551 	/* Release the socket */
552 	fput(s->sock->file);
553 
554 	__bnep_unlink_session(s);
555 
556 	up_write(&bnep_session_sem);
557 	free_netdev(dev);
558 	module_put_and_kthread_exit(0);
559 	return 0;
560 }
561 
562 static struct l2cap_conn *bnep_get_conn(struct bnep_session *session)
563 {
564 	struct l2cap_chan *chan = l2cap_pi(session->sock->sk)->chan;
565 	struct l2cap_conn *conn;
566 
567 	l2cap_chan_lock(chan);
568 	conn = chan->conn;
569 	if (conn)
570 		l2cap_conn_get(conn);
571 	l2cap_chan_unlock(chan);
572 
573 	return conn;
574 }
575 
576 static const struct device_type bnep_type = {
577 	.name	= "bluetooth",
578 };
579 
580 int bnep_add_connection(struct bnep_connadd_req *req, struct socket *sock)
581 {
582 	u32 valid_flags = BIT(BNEP_SETUP_RESPONSE);
583 	struct net_device *dev;
584 	struct bnep_session *s, *ss;
585 	struct l2cap_conn *conn = NULL;
586 	u8 dst[ETH_ALEN], src[ETH_ALEN];
587 	int err;
588 
589 	BT_DBG("");
590 
591 	if (!l2cap_is_socket(sock))
592 		return -EBADFD;
593 
594 	if (req->flags & ~valid_flags)
595 		return -EINVAL;
596 
597 	baswap((void *) dst, &l2cap_pi(sock->sk)->chan->dst);
598 	baswap((void *) src, &l2cap_pi(sock->sk)->chan->src);
599 
600 	/* session struct allocated as private part of net_device */
601 	dev = alloc_netdev(sizeof(struct bnep_session),
602 			   (*req->device) ? req->device : "bnep%d",
603 			   NET_NAME_UNKNOWN,
604 			   bnep_net_setup);
605 	if (!dev)
606 		return -ENOMEM;
607 
608 	down_write(&bnep_session_sem);
609 
610 	ss = __bnep_get_session(dst);
611 	if (ss && ss->state == BT_CONNECTED) {
612 		err = -EEXIST;
613 		goto failed;
614 	}
615 
616 	s = netdev_priv(dev);
617 
618 	/* This is rx header therefore addresses are swapped.
619 	 * ie. eh.h_dest is our local address. */
620 	memcpy(s->eh.h_dest,   &src, ETH_ALEN);
621 	memcpy(s->eh.h_source, &dst, ETH_ALEN);
622 	eth_hw_addr_set(dev, s->eh.h_dest);
623 
624 	s->dev   = dev;
625 	s->sock  = sock;
626 	s->role  = req->role;
627 	s->state = BT_CONNECTED;
628 	s->flags = req->flags;
629 
630 	s->msg.msg_flags = MSG_NOSIGNAL;
631 
632 #ifdef CONFIG_BT_BNEP_MC_FILTER
633 	/* Set default mc filter to not filter out any mc addresses
634 	 * as defined in the BNEP specification (revision 0.95a)
635 	 * http://grouper.ieee.org/groups/802/15/Bluetooth/BNEP.pdf
636 	 */
637 	s->mc_filter = ~0LL;
638 #endif
639 
640 #ifdef CONFIG_BT_BNEP_PROTO_FILTER
641 	/* Set default protocol filter */
642 	bnep_set_default_proto_filter(s);
643 #endif
644 
645 	conn = bnep_get_conn(s);
646 	if (!conn) {
647 		err = -ENOTCONN;
648 		goto failed;
649 	}
650 
651 	SET_NETDEV_DEV(dev, &conn->hcon->dev);
652 	SET_NETDEV_DEVTYPE(dev, &bnep_type);
653 
654 	err = register_netdev(dev);
655 	l2cap_conn_put(conn);
656 	conn = NULL;
657 	if (err)
658 		goto failed;
659 
660 	__bnep_link_session(s);
661 
662 	__module_get(THIS_MODULE);
663 	s->task = kthread_run(bnep_session, s, "kbnepd %s", dev->name);
664 	if (IS_ERR(s->task)) {
665 		/* Session thread start failed, gotta cleanup. */
666 		module_put(THIS_MODULE);
667 		unregister_netdev(dev);
668 		__bnep_unlink_session(s);
669 		err = PTR_ERR(s->task);
670 		goto failed;
671 	}
672 
673 	strcpy(req->device, dev->name);
674 	up_write(&bnep_session_sem);
675 	return 0;
676 
677 failed:
678 	if (conn)
679 		l2cap_conn_put(conn);
680 	up_write(&bnep_session_sem);
681 	free_netdev(dev);
682 	return err;
683 }
684 
685 int bnep_del_connection(struct bnep_conndel_req *req)
686 {
687 	u32 valid_flags = 0;
688 	struct bnep_session *s;
689 	int  err = 0;
690 
691 	BT_DBG("");
692 
693 	if (req->flags & ~valid_flags)
694 		return -EINVAL;
695 
696 	down_read(&bnep_session_sem);
697 
698 	s = __bnep_get_session(req->dst);
699 	if (s) {
700 		atomic_inc(&s->terminate);
701 		wake_up_interruptible(sk_sleep(s->sock->sk));
702 	} else
703 		err = -ENOENT;
704 
705 	up_read(&bnep_session_sem);
706 	return err;
707 }
708 
709 static void __bnep_copy_ci(struct bnep_conninfo *ci, struct bnep_session *s)
710 {
711 	u32 valid_flags = BIT(BNEP_SETUP_RESPONSE);
712 
713 	memset(ci, 0, sizeof(*ci));
714 	memcpy(ci->dst, s->eh.h_source, ETH_ALEN);
715 	strcpy(ci->device, s->dev->name);
716 	ci->flags = s->flags & valid_flags;
717 	ci->state = s->state;
718 	ci->role  = s->role;
719 }
720 
721 int bnep_get_connlist(struct bnep_connlist_req *req)
722 {
723 	struct bnep_session *s;
724 	int err = 0, n = 0;
725 
726 	down_read(&bnep_session_sem);
727 
728 	list_for_each_entry(s, &bnep_session_list, list) {
729 		struct bnep_conninfo ci;
730 
731 		__bnep_copy_ci(&ci, s);
732 
733 		if (copy_to_user(req->ci, &ci, sizeof(ci))) {
734 			err = -EFAULT;
735 			break;
736 		}
737 
738 		if (++n >= req->cnum)
739 			break;
740 
741 		req->ci++;
742 	}
743 	req->cnum = n;
744 
745 	up_read(&bnep_session_sem);
746 	return err;
747 }
748 
749 int bnep_get_conninfo(struct bnep_conninfo *ci)
750 {
751 	struct bnep_session *s;
752 	int err = 0;
753 
754 	down_read(&bnep_session_sem);
755 
756 	s = __bnep_get_session(ci->dst);
757 	if (s)
758 		__bnep_copy_ci(ci, s);
759 	else
760 		err = -ENOENT;
761 
762 	up_read(&bnep_session_sem);
763 	return err;
764 }
765 
766 static int __init bnep_init(void)
767 {
768 	char flt[50] = "";
769 
770 #ifdef CONFIG_BT_BNEP_PROTO_FILTER
771 	strcat(flt, "protocol ");
772 #endif
773 
774 #ifdef CONFIG_BT_BNEP_MC_FILTER
775 	strcat(flt, "multicast");
776 #endif
777 
778 	BT_INFO("BNEP (Ethernet Emulation) ver %s", VERSION);
779 	if (flt[0])
780 		BT_INFO("BNEP filters: %s", flt);
781 
782 	return bnep_sock_init();
783 }
784 
785 static void __exit bnep_exit(void)
786 {
787 	bnep_sock_cleanup();
788 }
789 
790 module_init(bnep_init);
791 module_exit(bnep_exit);
792 
793 module_param(compress_src, bool, 0644);
794 MODULE_PARM_DESC(compress_src, "Compress sources headers");
795 
796 module_param(compress_dst, bool, 0644);
797 MODULE_PARM_DESC(compress_dst, "Compress destination headers");
798 
799 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
800 MODULE_DESCRIPTION("Bluetooth BNEP ver " VERSION);
801 MODULE_VERSION(VERSION);
802 MODULE_LICENSE("GPL");
803 MODULE_ALIAS("bt-proto-4");
804