Linux 4.19-rc7
[linux-2.6/btrfs-unstable.git] / net / bluetooth / bnep / core.c
blob7b3965861013c4ed85f818efaff54336a3dc84fe
1 /*
2 BNEP implementation for Linux Bluetooth stack (BlueZ).
3 Copyright (C) 2001-2002 Inventel Systemes
4 Written 2001-2002 by
5 Clément Moreau <clement.moreau@inventel.fr>
6 David Libault <david.libault@inventel.fr>
8 Copyright (C) 2002 Maxim Krasnyansky <maxk@qualcomm.com>
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;
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.
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.
28 #include <linux/module.h>
29 #include <linux/kthread.h>
30 #include <linux/file.h>
31 #include <linux/etherdevice.h>
32 #include <asm/unaligned.h>
34 #include <net/bluetooth/bluetooth.h>
35 #include <net/bluetooth/l2cap.h>
36 #include <net/bluetooth/hci_core.h>
38 #include "bnep.h"
40 #define VERSION "1.3"
42 static bool compress_src = true;
43 static bool compress_dst = true;
45 static LIST_HEAD(bnep_session_list);
46 static DECLARE_RWSEM(bnep_session_sem);
48 static struct bnep_session *__bnep_get_session(u8 *dst)
50 struct bnep_session *s;
52 BT_DBG("");
54 list_for_each_entry(s, &bnep_session_list, list)
55 if (ether_addr_equal(dst, s->eh.h_source))
56 return s;
58 return NULL;
61 static void __bnep_link_session(struct bnep_session *s)
63 list_add(&s->list, &bnep_session_list);
66 static void __bnep_unlink_session(struct bnep_session *s)
68 list_del(&s->list);
71 static int bnep_send(struct bnep_session *s, void *data, size_t len)
73 struct socket *sock = s->sock;
74 struct kvec iv = { data, len };
76 return kernel_sendmsg(sock, &s->msg, &iv, 1, len);
79 static int bnep_send_rsp(struct bnep_session *s, u8 ctrl, u16 resp)
81 struct bnep_control_rsp rsp;
82 rsp.type = BNEP_CONTROL;
83 rsp.ctrl = ctrl;
84 rsp.resp = htons(resp);
85 return bnep_send(s, &rsp, sizeof(rsp));
88 #ifdef CONFIG_BT_BNEP_PROTO_FILTER
89 static inline void bnep_set_default_proto_filter(struct bnep_session *s)
91 /* (IPv4, ARP) */
92 s->proto_filter[0].start = ETH_P_IP;
93 s->proto_filter[0].end = ETH_P_ARP;
94 /* (RARP, AppleTalk) */
95 s->proto_filter[1].start = ETH_P_RARP;
96 s->proto_filter[1].end = ETH_P_AARP;
97 /* (IPX, IPv6) */
98 s->proto_filter[2].start = ETH_P_IPX;
99 s->proto_filter[2].end = ETH_P_IPV6;
101 #endif
103 static int bnep_ctrl_set_netfilter(struct bnep_session *s, __be16 *data, int len)
105 int n;
107 if (len < 2)
108 return -EILSEQ;
110 n = get_unaligned_be16(data);
111 data++;
112 len -= 2;
114 if (len < n)
115 return -EILSEQ;
117 BT_DBG("filter len %d", n);
119 #ifdef CONFIG_BT_BNEP_PROTO_FILTER
120 n /= 4;
121 if (n <= BNEP_MAX_PROTO_FILTERS) {
122 struct bnep_proto_filter *f = s->proto_filter;
123 int i;
125 for (i = 0; i < n; i++) {
126 f[i].start = get_unaligned_be16(data++);
127 f[i].end = get_unaligned_be16(data++);
129 BT_DBG("proto filter start %d end %d",
130 f[i].start, f[i].end);
133 if (i < BNEP_MAX_PROTO_FILTERS)
134 memset(f + i, 0, sizeof(*f));
136 if (n == 0)
137 bnep_set_default_proto_filter(s);
139 bnep_send_rsp(s, BNEP_FILTER_NET_TYPE_RSP, BNEP_SUCCESS);
140 } else {
141 bnep_send_rsp(s, BNEP_FILTER_NET_TYPE_RSP, BNEP_FILTER_LIMIT_REACHED);
143 #else
144 bnep_send_rsp(s, BNEP_FILTER_NET_TYPE_RSP, BNEP_FILTER_UNSUPPORTED_REQ);
145 #endif
146 return 0;
149 static int bnep_ctrl_set_mcfilter(struct bnep_session *s, u8 *data, int len)
151 int n;
153 if (len < 2)
154 return -EILSEQ;
156 n = get_unaligned_be16(data);
157 data += 2;
158 len -= 2;
160 if (len < n)
161 return -EILSEQ;
163 BT_DBG("filter len %d", n);
165 #ifdef CONFIG_BT_BNEP_MC_FILTER
166 n /= (ETH_ALEN * 2);
168 if (n > 0) {
169 int i;
171 s->mc_filter = 0;
173 /* Always send broadcast */
174 set_bit(bnep_mc_hash(s->dev->broadcast), (ulong *) &s->mc_filter);
176 /* Add address ranges to the multicast hash */
177 for (; n > 0; n--) {
178 u8 a1[6], *a2;
180 memcpy(a1, data, ETH_ALEN);
181 data += ETH_ALEN;
182 a2 = data;
183 data += ETH_ALEN;
185 BT_DBG("mc filter %pMR -> %pMR", a1, a2);
187 /* Iterate from a1 to a2 */
188 set_bit(bnep_mc_hash(a1), (ulong *) &s->mc_filter);
189 while (memcmp(a1, a2, 6) < 0 && s->mc_filter != ~0LL) {
190 /* Increment a1 */
191 i = 5;
192 while (i >= 0 && ++a1[i--] == 0)
195 set_bit(bnep_mc_hash(a1), (ulong *) &s->mc_filter);
200 BT_DBG("mc filter hash 0x%llx", s->mc_filter);
202 bnep_send_rsp(s, BNEP_FILTER_MULTI_ADDR_RSP, BNEP_SUCCESS);
203 #else
204 bnep_send_rsp(s, BNEP_FILTER_MULTI_ADDR_RSP, BNEP_FILTER_UNSUPPORTED_REQ);
205 #endif
206 return 0;
209 static int bnep_rx_control(struct bnep_session *s, void *data, int len)
211 u8 cmd = *(u8 *)data;
212 int err = 0;
214 data++;
215 len--;
217 switch (cmd) {
218 case BNEP_CMD_NOT_UNDERSTOOD:
219 case BNEP_SETUP_CONN_RSP:
220 case BNEP_FILTER_NET_TYPE_RSP:
221 case BNEP_FILTER_MULTI_ADDR_RSP:
222 /* Ignore these for now */
223 break;
225 case BNEP_FILTER_NET_TYPE_SET:
226 err = bnep_ctrl_set_netfilter(s, data, len);
227 break;
229 case BNEP_FILTER_MULTI_ADDR_SET:
230 err = bnep_ctrl_set_mcfilter(s, data, len);
231 break;
233 case BNEP_SETUP_CONN_REQ:
234 /* Successful response should be sent only once */
235 if (test_bit(BNEP_SETUP_RESPONSE, &s->flags) &&
236 !test_and_set_bit(BNEP_SETUP_RSP_SENT, &s->flags))
237 err = bnep_send_rsp(s, BNEP_SETUP_CONN_RSP,
238 BNEP_SUCCESS);
239 else
240 err = bnep_send_rsp(s, BNEP_SETUP_CONN_RSP,
241 BNEP_CONN_NOT_ALLOWED);
242 break;
244 default: {
245 u8 pkt[3];
246 pkt[0] = BNEP_CONTROL;
247 pkt[1] = BNEP_CMD_NOT_UNDERSTOOD;
248 pkt[2] = cmd;
249 err = bnep_send(s, pkt, sizeof(pkt));
251 break;
254 return err;
257 static int bnep_rx_extension(struct bnep_session *s, struct sk_buff *skb)
259 struct bnep_ext_hdr *h;
260 int err = 0;
262 do {
263 h = (void *) skb->data;
264 if (!skb_pull(skb, sizeof(*h))) {
265 err = -EILSEQ;
266 break;
269 BT_DBG("type 0x%x len %d", h->type, h->len);
271 switch (h->type & BNEP_TYPE_MASK) {
272 case BNEP_EXT_CONTROL:
273 bnep_rx_control(s, skb->data, skb->len);
274 break;
276 default:
277 /* Unknown extension, skip it. */
278 break;
281 if (!skb_pull(skb, h->len)) {
282 err = -EILSEQ;
283 break;
285 } while (!err && (h->type & BNEP_EXT_HEADER));
287 return err;
290 static u8 __bnep_rx_hlen[] = {
291 ETH_HLEN, /* BNEP_GENERAL */
292 0, /* BNEP_CONTROL */
293 2, /* BNEP_COMPRESSED */
294 ETH_ALEN + 2, /* BNEP_COMPRESSED_SRC_ONLY */
295 ETH_ALEN + 2 /* BNEP_COMPRESSED_DST_ONLY */
298 static int bnep_rx_frame(struct bnep_session *s, struct sk_buff *skb)
300 struct net_device *dev = s->dev;
301 struct sk_buff *nskb;
302 u8 type, ctrl_type;
304 dev->stats.rx_bytes += skb->len;
306 type = *(u8 *) skb->data;
307 skb_pull(skb, 1);
308 ctrl_type = *(u8 *)skb->data;
310 if ((type & BNEP_TYPE_MASK) >= sizeof(__bnep_rx_hlen))
311 goto badframe;
313 if ((type & BNEP_TYPE_MASK) == BNEP_CONTROL) {
314 if (bnep_rx_control(s, skb->data, skb->len) < 0) {
315 dev->stats.tx_errors++;
316 kfree_skb(skb);
317 return 0;
320 if (!(type & BNEP_EXT_HEADER)) {
321 kfree_skb(skb);
322 return 0;
325 /* Verify and pull ctrl message since it's already processed */
326 switch (ctrl_type) {
327 case BNEP_SETUP_CONN_REQ:
328 /* Pull: ctrl type (1 b), len (1 b), data (len bytes) */
329 if (!skb_pull(skb, 2 + *(u8 *)(skb->data + 1) * 2))
330 goto badframe;
331 break;
332 case BNEP_FILTER_MULTI_ADDR_SET:
333 case BNEP_FILTER_NET_TYPE_SET:
334 /* Pull: ctrl type (1 b), len (2 b), data (len bytes) */
335 if (!skb_pull(skb, 3 + *(u16 *)(skb->data + 1) * 2))
336 goto badframe;
337 break;
338 default:
339 kfree_skb(skb);
340 return 0;
342 } else {
343 skb_reset_mac_header(skb);
345 /* Verify and pull out header */
346 if (!skb_pull(skb, __bnep_rx_hlen[type & BNEP_TYPE_MASK]))
347 goto badframe;
349 s->eh.h_proto = get_unaligned((__be16 *) (skb->data - 2));
352 if (type & BNEP_EXT_HEADER) {
353 if (bnep_rx_extension(s, skb) < 0)
354 goto badframe;
357 /* Strip 802.1p header */
358 if (ntohs(s->eh.h_proto) == ETH_P_8021Q) {
359 if (!skb_pull(skb, 4))
360 goto badframe;
361 s->eh.h_proto = get_unaligned((__be16 *) (skb->data - 2));
364 /* We have to alloc new skb and copy data here :(. Because original skb
365 * may not be modified and because of the alignment requirements. */
366 nskb = alloc_skb(2 + ETH_HLEN + skb->len, GFP_KERNEL);
367 if (!nskb) {
368 dev->stats.rx_dropped++;
369 kfree_skb(skb);
370 return -ENOMEM;
372 skb_reserve(nskb, 2);
374 /* Decompress header and construct ether frame */
375 switch (type & BNEP_TYPE_MASK) {
376 case BNEP_COMPRESSED:
377 __skb_put_data(nskb, &s->eh, ETH_HLEN);
378 break;
380 case BNEP_COMPRESSED_SRC_ONLY:
381 __skb_put_data(nskb, s->eh.h_dest, ETH_ALEN);
382 __skb_put_data(nskb, skb_mac_header(skb), ETH_ALEN);
383 put_unaligned(s->eh.h_proto, (__be16 *) __skb_put(nskb, 2));
384 break;
386 case BNEP_COMPRESSED_DST_ONLY:
387 __skb_put_data(nskb, skb_mac_header(skb), ETH_ALEN);
388 __skb_put_data(nskb, s->eh.h_source, ETH_ALEN + 2);
389 break;
391 case BNEP_GENERAL:
392 __skb_put_data(nskb, skb_mac_header(skb), ETH_ALEN * 2);
393 put_unaligned(s->eh.h_proto, (__be16 *) __skb_put(nskb, 2));
394 break;
397 skb_copy_from_linear_data(skb, __skb_put(nskb, skb->len), skb->len);
398 kfree_skb(skb);
400 dev->stats.rx_packets++;
401 nskb->ip_summed = CHECKSUM_NONE;
402 nskb->protocol = eth_type_trans(nskb, dev);
403 netif_rx_ni(nskb);
404 return 0;
406 badframe:
407 dev->stats.rx_errors++;
408 kfree_skb(skb);
409 return 0;
412 static u8 __bnep_tx_types[] = {
413 BNEP_GENERAL,
414 BNEP_COMPRESSED_SRC_ONLY,
415 BNEP_COMPRESSED_DST_ONLY,
416 BNEP_COMPRESSED
419 static int bnep_tx_frame(struct bnep_session *s, struct sk_buff *skb)
421 struct ethhdr *eh = (void *) skb->data;
422 struct socket *sock = s->sock;
423 struct kvec iv[3];
424 int len = 0, il = 0;
425 u8 type = 0;
427 BT_DBG("skb %p dev %p type %d", skb, skb->dev, skb->pkt_type);
429 if (!skb->dev) {
430 /* Control frame sent by us */
431 goto send;
434 iv[il++] = (struct kvec) { &type, 1 };
435 len++;
437 if (compress_src && ether_addr_equal(eh->h_dest, s->eh.h_source))
438 type |= 0x01;
440 if (compress_dst && ether_addr_equal(eh->h_source, s->eh.h_dest))
441 type |= 0x02;
443 if (type)
444 skb_pull(skb, ETH_ALEN * 2);
446 type = __bnep_tx_types[type];
447 switch (type) {
448 case BNEP_COMPRESSED_SRC_ONLY:
449 iv[il++] = (struct kvec) { eh->h_source, ETH_ALEN };
450 len += ETH_ALEN;
451 break;
453 case BNEP_COMPRESSED_DST_ONLY:
454 iv[il++] = (struct kvec) { eh->h_dest, ETH_ALEN };
455 len += ETH_ALEN;
456 break;
459 send:
460 iv[il++] = (struct kvec) { skb->data, skb->len };
461 len += skb->len;
463 /* FIXME: linearize skb */
465 len = kernel_sendmsg(sock, &s->msg, iv, il, len);
467 kfree_skb(skb);
469 if (len > 0) {
470 s->dev->stats.tx_bytes += len;
471 s->dev->stats.tx_packets++;
472 return 0;
475 return len;
478 static int bnep_session(void *arg)
480 struct bnep_session *s = arg;
481 struct net_device *dev = s->dev;
482 struct sock *sk = s->sock->sk;
483 struct sk_buff *skb;
484 DEFINE_WAIT_FUNC(wait, woken_wake_function);
486 BT_DBG("");
488 set_user_nice(current, -15);
490 add_wait_queue(sk_sleep(sk), &wait);
491 while (1) {
492 /* Ensure session->terminate is updated */
493 smp_mb__before_atomic();
495 if (atomic_read(&s->terminate))
496 break;
497 /* RX */
498 while ((skb = skb_dequeue(&sk->sk_receive_queue))) {
499 skb_orphan(skb);
500 if (!skb_linearize(skb))
501 bnep_rx_frame(s, skb);
502 else
503 kfree_skb(skb);
506 if (sk->sk_state != BT_CONNECTED)
507 break;
509 /* TX */
510 while ((skb = skb_dequeue(&sk->sk_write_queue)))
511 if (bnep_tx_frame(s, skb))
512 break;
513 netif_wake_queue(dev);
515 wait_woken(&wait, TASK_INTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
517 remove_wait_queue(sk_sleep(sk), &wait);
519 /* Cleanup session */
520 down_write(&bnep_session_sem);
522 /* Delete network device */
523 unregister_netdev(dev);
525 /* Wakeup user-space polling for socket errors */
526 s->sock->sk->sk_err = EUNATCH;
528 wake_up_interruptible(sk_sleep(s->sock->sk));
530 /* Release the socket */
531 fput(s->sock->file);
533 __bnep_unlink_session(s);
535 up_write(&bnep_session_sem);
536 free_netdev(dev);
537 module_put_and_exit(0);
538 return 0;
541 static struct device *bnep_get_device(struct bnep_session *session)
543 struct l2cap_conn *conn = l2cap_pi(session->sock->sk)->chan->conn;
545 if (!conn || !conn->hcon)
546 return NULL;
548 return &conn->hcon->dev;
551 static struct device_type bnep_type = {
552 .name = "bluetooth",
555 int bnep_add_connection(struct bnep_connadd_req *req, struct socket *sock)
557 u32 valid_flags = BIT(BNEP_SETUP_RESPONSE);
558 struct net_device *dev;
559 struct bnep_session *s, *ss;
560 u8 dst[ETH_ALEN], src[ETH_ALEN];
561 int err;
563 BT_DBG("");
565 if (!l2cap_is_socket(sock))
566 return -EBADFD;
568 if (req->flags & ~valid_flags)
569 return -EINVAL;
571 baswap((void *) dst, &l2cap_pi(sock->sk)->chan->dst);
572 baswap((void *) src, &l2cap_pi(sock->sk)->chan->src);
574 /* session struct allocated as private part of net_device */
575 dev = alloc_netdev(sizeof(struct bnep_session),
576 (*req->device) ? req->device : "bnep%d",
577 NET_NAME_UNKNOWN,
578 bnep_net_setup);
579 if (!dev)
580 return -ENOMEM;
582 down_write(&bnep_session_sem);
584 ss = __bnep_get_session(dst);
585 if (ss && ss->state == BT_CONNECTED) {
586 err = -EEXIST;
587 goto failed;
590 s = netdev_priv(dev);
592 /* This is rx header therefore addresses are swapped.
593 * ie. eh.h_dest is our local address. */
594 memcpy(s->eh.h_dest, &src, ETH_ALEN);
595 memcpy(s->eh.h_source, &dst, ETH_ALEN);
596 memcpy(dev->dev_addr, s->eh.h_dest, ETH_ALEN);
598 s->dev = dev;
599 s->sock = sock;
600 s->role = req->role;
601 s->state = BT_CONNECTED;
602 s->flags = req->flags;
604 s->msg.msg_flags = MSG_NOSIGNAL;
606 #ifdef CONFIG_BT_BNEP_MC_FILTER
607 /* Set default mc filter to not filter out any mc addresses
608 * as defined in the BNEP specification (revision 0.95a)
609 * http://grouper.ieee.org/groups/802/15/Bluetooth/BNEP.pdf
611 s->mc_filter = ~0LL;
612 #endif
614 #ifdef CONFIG_BT_BNEP_PROTO_FILTER
615 /* Set default protocol filter */
616 bnep_set_default_proto_filter(s);
617 #endif
619 SET_NETDEV_DEV(dev, bnep_get_device(s));
620 SET_NETDEV_DEVTYPE(dev, &bnep_type);
622 err = register_netdev(dev);
623 if (err)
624 goto failed;
626 __bnep_link_session(s);
628 __module_get(THIS_MODULE);
629 s->task = kthread_run(bnep_session, s, "kbnepd %s", dev->name);
630 if (IS_ERR(s->task)) {
631 /* Session thread start failed, gotta cleanup. */
632 module_put(THIS_MODULE);
633 unregister_netdev(dev);
634 __bnep_unlink_session(s);
635 err = PTR_ERR(s->task);
636 goto failed;
639 up_write(&bnep_session_sem);
640 strcpy(req->device, dev->name);
641 return 0;
643 failed:
644 up_write(&bnep_session_sem);
645 free_netdev(dev);
646 return err;
649 int bnep_del_connection(struct bnep_conndel_req *req)
651 u32 valid_flags = 0;
652 struct bnep_session *s;
653 int err = 0;
655 BT_DBG("");
657 if (req->flags & ~valid_flags)
658 return -EINVAL;
660 down_read(&bnep_session_sem);
662 s = __bnep_get_session(req->dst);
663 if (s) {
664 atomic_inc(&s->terminate);
665 wake_up_interruptible(sk_sleep(s->sock->sk));
666 } else
667 err = -ENOENT;
669 up_read(&bnep_session_sem);
670 return err;
673 static void __bnep_copy_ci(struct bnep_conninfo *ci, struct bnep_session *s)
675 u32 valid_flags = BIT(BNEP_SETUP_RESPONSE);
677 memset(ci, 0, sizeof(*ci));
678 memcpy(ci->dst, s->eh.h_source, ETH_ALEN);
679 strcpy(ci->device, s->dev->name);
680 ci->flags = s->flags & valid_flags;
681 ci->state = s->state;
682 ci->role = s->role;
685 int bnep_get_connlist(struct bnep_connlist_req *req)
687 struct bnep_session *s;
688 int err = 0, n = 0;
690 down_read(&bnep_session_sem);
692 list_for_each_entry(s, &bnep_session_list, list) {
693 struct bnep_conninfo ci;
695 __bnep_copy_ci(&ci, s);
697 if (copy_to_user(req->ci, &ci, sizeof(ci))) {
698 err = -EFAULT;
699 break;
702 if (++n >= req->cnum)
703 break;
705 req->ci++;
707 req->cnum = n;
709 up_read(&bnep_session_sem);
710 return err;
713 int bnep_get_conninfo(struct bnep_conninfo *ci)
715 struct bnep_session *s;
716 int err = 0;
718 down_read(&bnep_session_sem);
720 s = __bnep_get_session(ci->dst);
721 if (s)
722 __bnep_copy_ci(ci, s);
723 else
724 err = -ENOENT;
726 up_read(&bnep_session_sem);
727 return err;
730 static int __init bnep_init(void)
732 char flt[50] = "";
734 #ifdef CONFIG_BT_BNEP_PROTO_FILTER
735 strcat(flt, "protocol ");
736 #endif
738 #ifdef CONFIG_BT_BNEP_MC_FILTER
739 strcat(flt, "multicast");
740 #endif
742 BT_INFO("BNEP (Ethernet Emulation) ver %s", VERSION);
743 if (flt[0])
744 BT_INFO("BNEP filters: %s", flt);
746 bnep_sock_init();
747 return 0;
750 static void __exit bnep_exit(void)
752 bnep_sock_cleanup();
755 module_init(bnep_init);
756 module_exit(bnep_exit);
758 module_param(compress_src, bool, 0644);
759 MODULE_PARM_DESC(compress_src, "Compress sources headers");
761 module_param(compress_dst, bool, 0644);
762 MODULE_PARM_DESC(compress_dst, "Compress destination headers");
764 MODULE_AUTHOR("Marcel Holtmann <marcel@holtmann.org>");
765 MODULE_DESCRIPTION("Bluetooth BNEP ver " VERSION);
766 MODULE_VERSION(VERSION);
767 MODULE_LICENSE("GPL");
768 MODULE_ALIAS("bt-proto-4");