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1/*
2 Copyright (c) 2013-2014 Intel Corp.
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License version 2 and
6 only version 2 as published by the Free Software Foundation.
7
8 This program is distributed in the hope that it will be useful,
9 but WITHOUT ANY WARRANTY; without even the implied warranty of
10 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 GNU General Public License for more details.
12*/
13
14#include <linux/if_arp.h>
15#include <linux/netdevice.h>
16#include <linux/etherdevice.h>
17#include <linux/module.h>
18#include <linux/debugfs.h>
19
20#include <net/ipv6.h>
21#include <net/ip6_route.h>
22#include <net/addrconf.h>
23
24#include <net/bluetooth/bluetooth.h>
25#include <net/bluetooth/hci_core.h>
26#include <net/bluetooth/l2cap.h>
27
28#include <net/6lowpan.h> /* for the compression support */
29
30#define VERSION "0.1"
31
32static struct dentry *lowpan_enable_debugfs;
33static struct dentry *lowpan_control_debugfs;
34
35#define IFACE_NAME_TEMPLATE "bt%d"
36
37struct skb_cb {
38 struct in6_addr addr;
39 struct in6_addr gw;
40 struct l2cap_chan *chan;
41 int status;
42};
43#define lowpan_cb(skb) ((struct skb_cb *)((skb)->cb))
44
45/* The devices list contains those devices that we are acting
46 * as a proxy. The BT 6LoWPAN device is a virtual device that
47 * connects to the Bluetooth LE device. The real connection to
48 * BT device is done via l2cap layer. There exists one
49 * virtual device / one BT 6LoWPAN network (=hciX device).
50 * The list contains struct lowpan_dev elements.
51 */
52static LIST_HEAD(bt_6lowpan_devices);
53static DEFINE_SPINLOCK(devices_lock);
54
55static bool enable_6lowpan;
56
57/* We are listening incoming connections via this channel
58 */
59static struct l2cap_chan *listen_chan;
60
61struct lowpan_peer {
62 struct list_head list;
63 struct rcu_head rcu;
64 struct l2cap_chan *chan;
65
66 /* peer addresses in various formats */
67 unsigned char eui64_addr[EUI64_ADDR_LEN];
68 struct in6_addr peer_addr;
69};
70
71struct lowpan_dev {
72 struct list_head list;
73
74 struct hci_dev *hdev;
75 struct net_device *netdev;
76 struct list_head peers;
77 atomic_t peer_count; /* number of items in peers list */
78
79 struct work_struct delete_netdev;
80 struct delayed_work notify_peers;
81};
82
83static inline struct lowpan_dev *lowpan_dev(const struct net_device *netdev)
84{
85 return (struct lowpan_dev *)lowpan_priv(netdev)->priv;
86}
87
88static inline void peer_add(struct lowpan_dev *dev, struct lowpan_peer *peer)
89{
90 list_add_rcu(&peer->list, &dev->peers);
91 atomic_inc(&dev->peer_count);
92}
93
94static inline bool peer_del(struct lowpan_dev *dev, struct lowpan_peer *peer)
95{
96 list_del_rcu(&peer->list);
97 kfree_rcu(peer, rcu);
98
99 module_put(THIS_MODULE);
100
101 if (atomic_dec_and_test(&dev->peer_count)) {
102 BT_DBG("last peer");
103 return true;
104 }
105
106 return false;
107}
108
109static inline struct lowpan_peer *peer_lookup_ba(struct lowpan_dev *dev,
110 bdaddr_t *ba, __u8 type)
111{
112 struct lowpan_peer *peer;
113
114 BT_DBG("peers %d addr %pMR type %d", atomic_read(&dev->peer_count),
115 ba, type);
116
117 rcu_read_lock();
118
119 list_for_each_entry_rcu(peer, &dev->peers, list) {
120 BT_DBG("dst addr %pMR dst type %d",
121 &peer->chan->dst, peer->chan->dst_type);
122
123 if (bacmp(&peer->chan->dst, ba))
124 continue;
125
126 if (type == peer->chan->dst_type) {
127 rcu_read_unlock();
128 return peer;
129 }
130 }
131
132 rcu_read_unlock();
133
134 return NULL;
135}
136
137static inline struct lowpan_peer *__peer_lookup_chan(struct lowpan_dev *dev,
138 struct l2cap_chan *chan)
139{
140 struct lowpan_peer *peer;
141
142 list_for_each_entry_rcu(peer, &dev->peers, list) {
143 if (peer->chan == chan)
144 return peer;
145 }
146
147 return NULL;
148}
149
150static inline struct lowpan_peer *__peer_lookup_conn(struct lowpan_dev *dev,
151 struct l2cap_conn *conn)
152{
153 struct lowpan_peer *peer;
154
155 list_for_each_entry_rcu(peer, &dev->peers, list) {
156 if (peer->chan->conn == conn)
157 return peer;
158 }
159
160 return NULL;
161}
162
163static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_dev *dev,
164 struct in6_addr *daddr,
165 struct sk_buff *skb)
166{
167 struct lowpan_peer *peer;
168 struct in6_addr *nexthop;
169 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
170 int count = atomic_read(&dev->peer_count);
171
172 BT_DBG("peers %d addr %pI6c rt %p", count, daddr, rt);
173
174 /* If we have multiple 6lowpan peers, then check where we should
175 * send the packet. If only one peer exists, then we can send the
176 * packet right away.
177 */
178 if (count == 1) {
179 rcu_read_lock();
180 peer = list_first_or_null_rcu(&dev->peers, struct lowpan_peer,
181 list);
182 rcu_read_unlock();
183 return peer;
184 }
185
186 if (!rt) {
187 nexthop = &lowpan_cb(skb)->gw;
188
189 if (ipv6_addr_any(nexthop))
190 return NULL;
191 } else {
192 nexthop = rt6_nexthop(rt, daddr);
193
194 /* We need to remember the address because it is needed
195 * by bt_xmit() when sending the packet. In bt_xmit(), the
196 * destination routing info is not set.
197 */
198 memcpy(&lowpan_cb(skb)->gw, nexthop, sizeof(struct in6_addr));
199 }
200
201 BT_DBG("gw %pI6c", nexthop);
202
203 rcu_read_lock();
204
205 list_for_each_entry_rcu(peer, &dev->peers, list) {
206 BT_DBG("dst addr %pMR dst type %d ip %pI6c",
207 &peer->chan->dst, peer->chan->dst_type,
208 &peer->peer_addr);
209
210 if (!ipv6_addr_cmp(&peer->peer_addr, nexthop)) {
211 rcu_read_unlock();
212 return peer;
213 }
214 }
215
216 rcu_read_unlock();
217
218 return NULL;
219}
220
221static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn)
222{
223 struct lowpan_dev *entry;
224 struct lowpan_peer *peer = NULL;
225
226 rcu_read_lock();
227
228 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
229 peer = __peer_lookup_conn(entry, conn);
230 if (peer)
231 break;
232 }
233
234 rcu_read_unlock();
235
236 return peer;
237}
238
239static struct lowpan_dev *lookup_dev(struct l2cap_conn *conn)
240{
241 struct lowpan_dev *entry;
242 struct lowpan_dev *dev = NULL;
243
244 rcu_read_lock();
245
246 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
247 if (conn->hcon->hdev == entry->hdev) {
248 dev = entry;
249 break;
250 }
251 }
252
253 rcu_read_unlock();
254
255 return dev;
256}
257
258static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev)
259{
260 struct sk_buff *skb_cp;
261
262 skb_cp = skb_copy(skb, GFP_ATOMIC);
263 if (!skb_cp)
264 return NET_RX_DROP;
265
266 return netif_rx_ni(skb_cp);
267}
268
269static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev,
270 struct l2cap_chan *chan)
271{
272 const u8 *saddr, *daddr;
273 struct lowpan_dev *dev;
274 struct lowpan_peer *peer;
275
276 dev = lowpan_dev(netdev);
277
278 rcu_read_lock();
279 peer = __peer_lookup_chan(dev, chan);
280 rcu_read_unlock();
281 if (!peer)
282 return -EINVAL;
283
284 saddr = peer->eui64_addr;
285 daddr = dev->netdev->dev_addr;
286
287 return lowpan_header_decompress(skb, netdev, daddr, saddr);
288}
289
290static int recv_pkt(struct sk_buff *skb, struct net_device *dev,
291 struct l2cap_chan *chan)
292{
293 struct sk_buff *local_skb;
294 int ret;
295
296 if (!netif_running(dev))
297 goto drop;
298
299 if (dev->type != ARPHRD_6LOWPAN || !skb->len)
300 goto drop;
301
302 skb_reset_network_header(skb);
303
304 skb = skb_share_check(skb, GFP_ATOMIC);
305 if (!skb)
306 goto drop;
307
308 /* check that it's our buffer */
309 if (lowpan_is_ipv6(*skb_network_header(skb))) {
310 /* Pull off the 1-byte of 6lowpan header. */
311 skb_pull(skb, 1);
312
313 /* Copy the packet so that the IPv6 header is
314 * properly aligned.
315 */
316 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
317 skb_tailroom(skb), GFP_ATOMIC);
318 if (!local_skb)
319 goto drop;
320
321 local_skb->protocol = htons(ETH_P_IPV6);
322 local_skb->pkt_type = PACKET_HOST;
323 local_skb->dev = dev;
324
325 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
326
327 if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) {
328 kfree_skb(local_skb);
329 goto drop;
330 }
331
332 dev->stats.rx_bytes += skb->len;
333 dev->stats.rx_packets++;
334
335 consume_skb(local_skb);
336 consume_skb(skb);
337 } else if (lowpan_is_iphc(*skb_network_header(skb))) {
338 local_skb = skb_clone(skb, GFP_ATOMIC);
339 if (!local_skb)
340 goto drop;
341
342 local_skb->dev = dev;
343
344 ret = iphc_decompress(local_skb, dev, chan);
345 if (ret < 0) {
346 kfree_skb(local_skb);
347 goto drop;
348 }
349
350 local_skb->protocol = htons(ETH_P_IPV6);
351 local_skb->pkt_type = PACKET_HOST;
352
353 if (give_skb_to_upper(local_skb, dev)
354 != NET_RX_SUCCESS) {
355 kfree_skb(local_skb);
356 goto drop;
357 }
358
359 dev->stats.rx_bytes += skb->len;
360 dev->stats.rx_packets++;
361
362 consume_skb(local_skb);
363 consume_skb(skb);
364 } else {
365 goto drop;
366 }
367
368 return NET_RX_SUCCESS;
369
370drop:
371 dev->stats.rx_dropped++;
372 return NET_RX_DROP;
373}
374
375/* Packet from BT LE device */
376static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
377{
378 struct lowpan_dev *dev;
379 struct lowpan_peer *peer;
380 int err;
381
382 peer = lookup_peer(chan->conn);
383 if (!peer)
384 return -ENOENT;
385
386 dev = lookup_dev(chan->conn);
387 if (!dev || !dev->netdev)
388 return -ENOENT;
389
390 err = recv_pkt(skb, dev->netdev, chan);
391 if (err) {
392 BT_DBG("recv pkt %d", err);
393 err = -EAGAIN;
394 }
395
396 return err;
397}
398
399static u8 get_addr_type_from_eui64(u8 byte)
400{
401 /* Is universal(0) or local(1) bit */
402 return ((byte & 0x02) ? BDADDR_LE_RANDOM : BDADDR_LE_PUBLIC);
403}
404
405static void copy_to_bdaddr(struct in6_addr *ip6_daddr, bdaddr_t *addr)
406{
407 u8 *eui64 = ip6_daddr->s6_addr + 8;
408
409 addr->b[0] = eui64[7];
410 addr->b[1] = eui64[6];
411 addr->b[2] = eui64[5];
412 addr->b[3] = eui64[2];
413 addr->b[4] = eui64[1];
414 addr->b[5] = eui64[0];
415}
416
417static void convert_dest_bdaddr(struct in6_addr *ip6_daddr,
418 bdaddr_t *addr, u8 *addr_type)
419{
420 copy_to_bdaddr(ip6_daddr, addr);
421
422 /* We need to toggle the U/L bit that we got from IPv6 address
423 * so that we get the proper address and type of the BD address.
424 */
425 addr->b[5] ^= 0x02;
426
427 *addr_type = get_addr_type_from_eui64(addr->b[5]);
428}
429
430static int setup_header(struct sk_buff *skb, struct net_device *netdev,
431 bdaddr_t *peer_addr, u8 *peer_addr_type)
432{
433 struct in6_addr ipv6_daddr;
434 struct lowpan_dev *dev;
435 struct lowpan_peer *peer;
436 bdaddr_t addr, *any = BDADDR_ANY;
437 u8 *daddr = any->b;
438 int err, status = 0;
439
440 dev = lowpan_dev(netdev);
441
442 memcpy(&ipv6_daddr, &lowpan_cb(skb)->addr, sizeof(ipv6_daddr));
443
444 if (ipv6_addr_is_multicast(&ipv6_daddr)) {
445 lowpan_cb(skb)->chan = NULL;
446 } else {
447 u8 addr_type;
448
449 /* Get destination BT device from skb.
450 * If there is no such peer then discard the packet.
451 */
452 convert_dest_bdaddr(&ipv6_daddr, &addr, &addr_type);
453
454 BT_DBG("dest addr %pMR type %d IP %pI6c", &addr,
455 addr_type, &ipv6_daddr);
456
457 peer = peer_lookup_ba(dev, &addr, addr_type);
458 if (!peer) {
459 /* The packet might be sent to 6lowpan interface
460 * because of routing (either via default route
461 * or user set route) so get peer according to
462 * the destination address.
463 */
464 peer = peer_lookup_dst(dev, &ipv6_daddr, skb);
465 if (!peer) {
466 BT_DBG("no such peer %pMR found", &addr);
467 return -ENOENT;
468 }
469 }
470
471 daddr = peer->eui64_addr;
472 *peer_addr = addr;
473 *peer_addr_type = addr_type;
474 lowpan_cb(skb)->chan = peer->chan;
475
476 status = 1;
477 }
478
479 lowpan_header_compress(skb, netdev, daddr, dev->netdev->dev_addr);
480
481 err = dev_hard_header(skb, netdev, ETH_P_IPV6, NULL, NULL, 0);
482 if (err < 0)
483 return err;
484
485 return status;
486}
487
488static int header_create(struct sk_buff *skb, struct net_device *netdev,
489 unsigned short type, const void *_daddr,
490 const void *_saddr, unsigned int len)
491{
492 struct ipv6hdr *hdr;
493
494 if (type != ETH_P_IPV6)
495 return -EINVAL;
496
497 hdr = ipv6_hdr(skb);
498
499 memcpy(&lowpan_cb(skb)->addr, &hdr->daddr, sizeof(struct in6_addr));
500
501 return 0;
502}
503
504/* Packet to BT LE device */
505static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb,
506 struct net_device *netdev)
507{
508 struct msghdr msg;
509 struct kvec iv;
510 int err;
511
512 /* Remember the skb so that we can send EAGAIN to the caller if
513 * we run out of credits.
514 */
515 chan->data = skb;
516
517 iv.iov_base = skb->data;
518 iv.iov_len = skb->len;
519
520 memset(&msg, 0, sizeof(msg));
521 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, &iv, 1, skb->len);
522
523 err = l2cap_chan_send(chan, &msg, skb->len);
524 if (err > 0) {
525 netdev->stats.tx_bytes += err;
526 netdev->stats.tx_packets++;
527 return 0;
528 }
529
530 if (!err)
531 err = lowpan_cb(skb)->status;
532
533 if (err < 0) {
534 if (err == -EAGAIN)
535 netdev->stats.tx_dropped++;
536 else
537 netdev->stats.tx_errors++;
538 }
539
540 return err;
541}
542
543static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev)
544{
545 struct sk_buff *local_skb;
546 struct lowpan_dev *entry;
547 int err = 0;
548
549 rcu_read_lock();
550
551 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
552 struct lowpan_peer *pentry;
553 struct lowpan_dev *dev;
554
555 if (entry->netdev != netdev)
556 continue;
557
558 dev = lowpan_dev(entry->netdev);
559
560 list_for_each_entry_rcu(pentry, &dev->peers, list) {
561 int ret;
562
563 local_skb = skb_clone(skb, GFP_ATOMIC);
564
565 BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
566 netdev->name,
567 &pentry->chan->dst, pentry->chan->dst_type,
568 &pentry->peer_addr, pentry->chan);
569 ret = send_pkt(pentry->chan, local_skb, netdev);
570 if (ret < 0)
571 err = ret;
572
573 kfree_skb(local_skb);
574 }
575 }
576
577 rcu_read_unlock();
578
579 return err;
580}
581
582static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev)
583{
584 int err = 0;
585 bdaddr_t addr;
586 u8 addr_type;
587
588 /* We must take a copy of the skb before we modify/replace the ipv6
589 * header as the header could be used elsewhere
590 */
591 skb = skb_unshare(skb, GFP_ATOMIC);
592 if (!skb)
593 return NET_XMIT_DROP;
594
595 /* Return values from setup_header()
596 * <0 - error, packet is dropped
597 * 0 - this is a multicast packet
598 * 1 - this is unicast packet
599 */
600 err = setup_header(skb, netdev, &addr, &addr_type);
601 if (err < 0) {
602 kfree_skb(skb);
603 return NET_XMIT_DROP;
604 }
605
606 if (err) {
607 if (lowpan_cb(skb)->chan) {
608 BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
609 netdev->name, &addr, addr_type,
610 &lowpan_cb(skb)->addr, lowpan_cb(skb)->chan);
611 err = send_pkt(lowpan_cb(skb)->chan, skb, netdev);
612 } else {
613 err = -ENOENT;
614 }
615 } else {
616 /* We need to send the packet to every device behind this
617 * interface.
618 */
619 err = send_mcast_pkt(skb, netdev);
620 }
621
622 dev_kfree_skb(skb);
623
624 if (err)
625 BT_DBG("ERROR: xmit failed (%d)", err);
626
627 return err < 0 ? NET_XMIT_DROP : err;
628}
629
630static struct lock_class_key bt_tx_busylock;
631static struct lock_class_key bt_netdev_xmit_lock_key;
632
633static void bt_set_lockdep_class_one(struct net_device *dev,
634 struct netdev_queue *txq,
635 void *_unused)
636{
637 lockdep_set_class(&txq->_xmit_lock, &bt_netdev_xmit_lock_key);
638}
639
640static int bt_dev_init(struct net_device *dev)
641{
642 netdev_for_each_tx_queue(dev, bt_set_lockdep_class_one, NULL);
643 dev->qdisc_tx_busylock = &bt_tx_busylock;
644
645 return 0;
646}
647
648static const struct net_device_ops netdev_ops = {
649 .ndo_init = bt_dev_init,
650 .ndo_start_xmit = bt_xmit,
651};
652
653static struct header_ops header_ops = {
654 .create = header_create,
655};
656
657static void netdev_setup(struct net_device *dev)
658{
659 dev->hard_header_len = 0;
660 dev->needed_tailroom = 0;
661 dev->flags = IFF_RUNNING | IFF_POINTOPOINT |
662 IFF_MULTICAST;
663 dev->watchdog_timeo = 0;
664
665 dev->netdev_ops = &netdev_ops;
666 dev->header_ops = &header_ops;
667 dev->destructor = free_netdev;
668}
669
670static struct device_type bt_type = {
671 .name = "bluetooth",
672};
673
674static void set_addr(u8 *eui, u8 *addr, u8 addr_type)
675{
676 /* addr is the BT address in little-endian format */
677 eui[0] = addr[5];
678 eui[1] = addr[4];
679 eui[2] = addr[3];
680 eui[3] = 0xFF;
681 eui[4] = 0xFE;
682 eui[5] = addr[2];
683 eui[6] = addr[1];
684 eui[7] = addr[0];
685
686 /* Universal/local bit set, BT 6lowpan draft ch. 3.2.1 */
687 if (addr_type == BDADDR_LE_PUBLIC)
688 eui[0] &= ~0x02;
689 else
690 eui[0] |= 0x02;
691
692 BT_DBG("type %d addr %*phC", addr_type, 8, eui);
693}
694
695static void set_dev_addr(struct net_device *netdev, bdaddr_t *addr,
696 u8 addr_type)
697{
698 netdev->addr_assign_type = NET_ADDR_PERM;
699 set_addr(netdev->dev_addr, addr->b, addr_type);
700}
701
702static void ifup(struct net_device *netdev)
703{
704 int err;
705
706 rtnl_lock();
707 err = dev_open(netdev);
708 if (err < 0)
709 BT_INFO("iface %s cannot be opened (%d)", netdev->name, err);
710 rtnl_unlock();
711}
712
713static void ifdown(struct net_device *netdev)
714{
715 int err;
716
717 rtnl_lock();
718 err = dev_close(netdev);
719 if (err < 0)
720 BT_INFO("iface %s cannot be closed (%d)", netdev->name, err);
721 rtnl_unlock();
722}
723
724static void do_notify_peers(struct work_struct *work)
725{
726 struct lowpan_dev *dev = container_of(work, struct lowpan_dev,
727 notify_peers.work);
728
729 netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */
730}
731
732static bool is_bt_6lowpan(struct hci_conn *hcon)
733{
734 if (hcon->type != LE_LINK)
735 return false;
736
737 if (!enable_6lowpan)
738 return false;
739
740 return true;
741}
742
743static struct l2cap_chan *chan_create(void)
744{
745 struct l2cap_chan *chan;
746
747 chan = l2cap_chan_create();
748 if (!chan)
749 return NULL;
750
751 l2cap_chan_set_defaults(chan);
752
753 chan->chan_type = L2CAP_CHAN_CONN_ORIENTED;
754 chan->mode = L2CAP_MODE_LE_FLOWCTL;
755 chan->imtu = 1280;
756
757 return chan;
758}
759
760static void set_ip_addr_bits(u8 addr_type, u8 *addr)
761{
762 if (addr_type == BDADDR_LE_PUBLIC)
763 *addr |= 0x02;
764 else
765 *addr &= ~0x02;
766}
767
768static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan,
769 struct lowpan_dev *dev)
770{
771 struct lowpan_peer *peer;
772
773 peer = kzalloc(sizeof(*peer), GFP_ATOMIC);
774 if (!peer)
775 return NULL;
776
777 peer->chan = chan;
778 memset(&peer->peer_addr, 0, sizeof(struct in6_addr));
779
780 /* RFC 2464 ch. 5 */
781 peer->peer_addr.s6_addr[0] = 0xFE;
782 peer->peer_addr.s6_addr[1] = 0x80;
783 set_addr((u8 *)&peer->peer_addr.s6_addr + 8, chan->dst.b,
784 chan->dst_type);
785
786 memcpy(&peer->eui64_addr, (u8 *)&peer->peer_addr.s6_addr + 8,
787 EUI64_ADDR_LEN);
788
789 /* IPv6 address needs to have the U/L bit set properly so toggle
790 * it back here.
791 */
792 set_ip_addr_bits(chan->dst_type, (u8 *)&peer->peer_addr.s6_addr + 8);
793
794 spin_lock(&devices_lock);
795 INIT_LIST_HEAD(&peer->list);
796 peer_add(dev, peer);
797 spin_unlock(&devices_lock);
798
799 /* Notifying peers about us needs to be done without locks held */
800 INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers);
801 schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100));
802
803 return peer->chan;
804}
805
806static int setup_netdev(struct l2cap_chan *chan, struct lowpan_dev **dev)
807{
808 struct net_device *netdev;
809 int err = 0;
810
811 netdev = alloc_netdev(LOWPAN_PRIV_SIZE(sizeof(struct lowpan_dev)),
812 IFACE_NAME_TEMPLATE, NET_NAME_UNKNOWN,
813 netdev_setup);
814 if (!netdev)
815 return -ENOMEM;
816
817 set_dev_addr(netdev, &chan->src, chan->src_type);
818
819 netdev->netdev_ops = &netdev_ops;
820 SET_NETDEV_DEV(netdev, &chan->conn->hcon->hdev->dev);
821 SET_NETDEV_DEVTYPE(netdev, &bt_type);
822
823 *dev = lowpan_dev(netdev);
824 (*dev)->netdev = netdev;
825 (*dev)->hdev = chan->conn->hcon->hdev;
826 INIT_LIST_HEAD(&(*dev)->peers);
827
828 spin_lock(&devices_lock);
829 INIT_LIST_HEAD(&(*dev)->list);
830 list_add_rcu(&(*dev)->list, &bt_6lowpan_devices);
831 spin_unlock(&devices_lock);
832
833 err = lowpan_register_netdev(netdev, LOWPAN_LLTYPE_BTLE);
834 if (err < 0) {
835 BT_INFO("register_netdev failed %d", err);
836 spin_lock(&devices_lock);
837 list_del_rcu(&(*dev)->list);
838 spin_unlock(&devices_lock);
839 free_netdev(netdev);
840 goto out;
841 }
842
843 BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d",
844 netdev->ifindex, &chan->dst, chan->dst_type,
845 &chan->src, chan->src_type);
846 set_bit(__LINK_STATE_PRESENT, &netdev->state);
847
848 return 0;
849
850out:
851 return err;
852}
853
854static inline void chan_ready_cb(struct l2cap_chan *chan)
855{
856 struct lowpan_dev *dev;
857
858 dev = lookup_dev(chan->conn);
859
860 BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev);
861
862 if (!dev) {
863 if (setup_netdev(chan, &dev) < 0) {
864 l2cap_chan_del(chan, -ENOENT);
865 return;
866 }
867 }
868
869 if (!try_module_get(THIS_MODULE))
870 return;
871
872 add_peer_chan(chan, dev);
873 ifup(dev->netdev);
874}
875
876static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan)
877{
878 struct l2cap_chan *chan;
879
880 chan = chan_create();
881 if (!chan)
882 return NULL;
883
884 chan->ops = pchan->ops;
885
886 BT_DBG("chan %p pchan %p", chan, pchan);
887
888 return chan;
889}
890
891static void delete_netdev(struct work_struct *work)
892{
893 struct lowpan_dev *entry = container_of(work, struct lowpan_dev,
894 delete_netdev);
895
896 lowpan_unregister_netdev(entry->netdev);
897
898 /* The entry pointer is deleted by the netdev destructor. */
899}
900
901static void chan_close_cb(struct l2cap_chan *chan)
902{
903 struct lowpan_dev *entry;
904 struct lowpan_dev *dev = NULL;
905 struct lowpan_peer *peer;
906 int err = -ENOENT;
907 bool last = false, remove = true;
908
909 BT_DBG("chan %p conn %p", chan, chan->conn);
910
911 if (chan->conn && chan->conn->hcon) {
912 if (!is_bt_6lowpan(chan->conn->hcon))
913 return;
914
915 /* If conn is set, then the netdev is also there and we should
916 * not remove it.
917 */
918 remove = false;
919 }
920
921 spin_lock(&devices_lock);
922
923 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
924 dev = lowpan_dev(entry->netdev);
925 peer = __peer_lookup_chan(dev, chan);
926 if (peer) {
927 last = peer_del(dev, peer);
928 err = 0;
929
930 BT_DBG("dev %p removing %speer %p", dev,
931 last ? "last " : "1 ", peer);
932 BT_DBG("chan %p orig refcnt %d", chan,
933 atomic_read(&chan->kref.refcount));
934
935 l2cap_chan_put(chan);
936 break;
937 }
938 }
939
940 if (!err && last && dev && !atomic_read(&dev->peer_count)) {
941 spin_unlock(&devices_lock);
942
943 cancel_delayed_work_sync(&dev->notify_peers);
944
945 ifdown(dev->netdev);
946
947 if (remove) {
948 INIT_WORK(&entry->delete_netdev, delete_netdev);
949 schedule_work(&entry->delete_netdev);
950 }
951 } else {
952 spin_unlock(&devices_lock);
953 }
954
955 return;
956}
957
958static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err)
959{
960 BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn,
961 state_to_string(state), err);
962}
963
964static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan,
965 unsigned long hdr_len,
966 unsigned long len, int nb)
967{
968 /* Note that we must allocate using GFP_ATOMIC here as
969 * this function is called originally from netdev hard xmit
970 * function in atomic context.
971 */
972 return bt_skb_alloc(hdr_len + len, GFP_ATOMIC);
973}
974
975static void chan_suspend_cb(struct l2cap_chan *chan)
976{
977 struct sk_buff *skb = chan->data;
978
979 BT_DBG("chan %p conn %p skb %p", chan, chan->conn, skb);
980
981 if (!skb)
982 return;
983
984 lowpan_cb(skb)->status = -EAGAIN;
985}
986
987static void chan_resume_cb(struct l2cap_chan *chan)
988{
989 struct sk_buff *skb = chan->data;
990
991 BT_DBG("chan %p conn %p skb %p", chan, chan->conn, skb);
992
993 if (!skb)
994 return;
995
996 lowpan_cb(skb)->status = 0;
997}
998
999static long chan_get_sndtimeo_cb(struct l2cap_chan *chan)
1000{
1001 return L2CAP_CONN_TIMEOUT;
1002}
1003
1004static const struct l2cap_ops bt_6lowpan_chan_ops = {
1005 .name = "L2CAP 6LoWPAN channel",
1006 .new_connection = chan_new_conn_cb,
1007 .recv = chan_recv_cb,
1008 .close = chan_close_cb,
1009 .state_change = chan_state_change_cb,
1010 .ready = chan_ready_cb,
1011 .resume = chan_resume_cb,
1012 .suspend = chan_suspend_cb,
1013 .get_sndtimeo = chan_get_sndtimeo_cb,
1014 .alloc_skb = chan_alloc_skb_cb,
1015
1016 .teardown = l2cap_chan_no_teardown,
1017 .defer = l2cap_chan_no_defer,
1018 .set_shutdown = l2cap_chan_no_set_shutdown,
1019};
1020
1021static inline __u8 bdaddr_type(__u8 type)
1022{
1023 if (type == ADDR_LE_DEV_PUBLIC)
1024 return BDADDR_LE_PUBLIC;
1025 else
1026 return BDADDR_LE_RANDOM;
1027}
1028
1029static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type)
1030{
1031 struct l2cap_chan *chan;
1032 int err;
1033
1034 chan = chan_create();
1035 if (!chan)
1036 return -EINVAL;
1037
1038 chan->ops = &bt_6lowpan_chan_ops;
1039
1040 err = l2cap_chan_connect(chan, cpu_to_le16(L2CAP_PSM_IPSP), 0,
1041 addr, dst_type);
1042
1043 BT_DBG("chan %p err %d", chan, err);
1044 if (err < 0)
1045 l2cap_chan_put(chan);
1046
1047 return err;
1048}
1049
1050static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type)
1051{
1052 struct lowpan_peer *peer;
1053
1054 BT_DBG("conn %p dst type %d", conn, dst_type);
1055
1056 peer = lookup_peer(conn);
1057 if (!peer)
1058 return -ENOENT;
1059
1060 BT_DBG("peer %p chan %p", peer, peer->chan);
1061
1062 l2cap_chan_close(peer->chan, ENOENT);
1063
1064 return 0;
1065}
1066
1067static struct l2cap_chan *bt_6lowpan_listen(void)
1068{
1069 bdaddr_t *addr = BDADDR_ANY;
1070 struct l2cap_chan *chan;
1071 int err;
1072
1073 if (!enable_6lowpan)
1074 return NULL;
1075
1076 chan = chan_create();
1077 if (!chan)
1078 return NULL;
1079
1080 chan->ops = &bt_6lowpan_chan_ops;
1081 chan->state = BT_LISTEN;
1082 chan->src_type = BDADDR_LE_PUBLIC;
1083
1084 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
1085
1086 BT_DBG("chan %p src type %d", chan, chan->src_type);
1087
1088 err = l2cap_add_psm(chan, addr, cpu_to_le16(L2CAP_PSM_IPSP));
1089 if (err) {
1090 l2cap_chan_put(chan);
1091 BT_ERR("psm cannot be added err %d", err);
1092 return NULL;
1093 }
1094
1095 return chan;
1096}
1097
1098static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type,
1099 struct l2cap_conn **conn)
1100{
1101 struct hci_conn *hcon;
1102 struct hci_dev *hdev;
1103 bdaddr_t *src = BDADDR_ANY;
1104 int n;
1105
1106 n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu",
1107 &addr->b[5], &addr->b[4], &addr->b[3],
1108 &addr->b[2], &addr->b[1], &addr->b[0],
1109 addr_type);
1110
1111 if (n < 7)
1112 return -EINVAL;
1113
1114 hdev = hci_get_route(addr, src);
1115 if (!hdev)
1116 return -ENOENT;
1117
1118 hci_dev_lock(hdev);
1119 hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type);
1120 hci_dev_unlock(hdev);
1121
1122 if (!hcon)
1123 return -ENOENT;
1124
1125 *conn = (struct l2cap_conn *)hcon->l2cap_data;
1126
1127 BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type);
1128
1129 return 0;
1130}
1131
1132static void disconnect_all_peers(void)
1133{
1134 struct lowpan_dev *entry;
1135 struct lowpan_peer *peer, *tmp_peer, *new_peer;
1136 struct list_head peers;
1137
1138 INIT_LIST_HEAD(&peers);
1139
1140 /* We make a separate list of peers as the close_cb() will
1141 * modify the device peers list so it is better not to mess
1142 * with the same list at the same time.
1143 */
1144
1145 rcu_read_lock();
1146
1147 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1148 list_for_each_entry_rcu(peer, &entry->peers, list) {
1149 new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC);
1150 if (!new_peer)
1151 break;
1152
1153 new_peer->chan = peer->chan;
1154 INIT_LIST_HEAD(&new_peer->list);
1155
1156 list_add(&new_peer->list, &peers);
1157 }
1158 }
1159
1160 rcu_read_unlock();
1161
1162 spin_lock(&devices_lock);
1163 list_for_each_entry_safe(peer, tmp_peer, &peers, list) {
1164 l2cap_chan_close(peer->chan, ENOENT);
1165
1166 list_del_rcu(&peer->list);
1167 kfree_rcu(peer, rcu);
1168 }
1169 spin_unlock(&devices_lock);
1170}
1171
1172struct set_enable {
1173 struct work_struct work;
1174 bool flag;
1175};
1176
1177static void do_enable_set(struct work_struct *work)
1178{
1179 struct set_enable *set_enable = container_of(work,
1180 struct set_enable, work);
1181
1182 if (!set_enable->flag || enable_6lowpan != set_enable->flag)
1183 /* Disconnect existing connections if 6lowpan is
1184 * disabled
1185 */
1186 disconnect_all_peers();
1187
1188 enable_6lowpan = set_enable->flag;
1189
1190 if (listen_chan) {
1191 l2cap_chan_close(listen_chan, 0);
1192 l2cap_chan_put(listen_chan);
1193 }
1194
1195 listen_chan = bt_6lowpan_listen();
1196
1197 kfree(set_enable);
1198}
1199
1200static int lowpan_enable_set(void *data, u64 val)
1201{
1202 struct set_enable *set_enable;
1203
1204 set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL);
1205 if (!set_enable)
1206 return -ENOMEM;
1207
1208 set_enable->flag = !!val;
1209 INIT_WORK(&set_enable->work, do_enable_set);
1210
1211 schedule_work(&set_enable->work);
1212
1213 return 0;
1214}
1215
1216static int lowpan_enable_get(void *data, u64 *val)
1217{
1218 *val = enable_6lowpan;
1219 return 0;
1220}
1221
1222DEFINE_SIMPLE_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get,
1223 lowpan_enable_set, "%llu\n");
1224
1225static ssize_t lowpan_control_write(struct file *fp,
1226 const char __user *user_buffer,
1227 size_t count,
1228 loff_t *position)
1229{
1230 char buf[32];
1231 size_t buf_size = min(count, sizeof(buf) - 1);
1232 int ret;
1233 bdaddr_t addr;
1234 u8 addr_type;
1235 struct l2cap_conn *conn = NULL;
1236
1237 if (copy_from_user(buf, user_buffer, buf_size))
1238 return -EFAULT;
1239
1240 buf[buf_size] = '\0';
1241
1242 if (memcmp(buf, "connect ", 8) == 0) {
1243 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn);
1244 if (ret == -EINVAL)
1245 return ret;
1246
1247 if (listen_chan) {
1248 l2cap_chan_close(listen_chan, 0);
1249 l2cap_chan_put(listen_chan);
1250 listen_chan = NULL;
1251 }
1252
1253 if (conn) {
1254 struct lowpan_peer *peer;
1255
1256 if (!is_bt_6lowpan(conn->hcon))
1257 return -EINVAL;
1258
1259 peer = lookup_peer(conn);
1260 if (peer) {
1261 BT_DBG("6LoWPAN connection already exists");
1262 return -EALREADY;
1263 }
1264
1265 BT_DBG("conn %p dst %pMR type %d user %d", conn,
1266 &conn->hcon->dst, conn->hcon->dst_type,
1267 addr_type);
1268 }
1269
1270 ret = bt_6lowpan_connect(&addr, addr_type);
1271 if (ret < 0)
1272 return ret;
1273
1274 return count;
1275 }
1276
1277 if (memcmp(buf, "disconnect ", 11) == 0) {
1278 ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn);
1279 if (ret < 0)
1280 return ret;
1281
1282 ret = bt_6lowpan_disconnect(conn, addr_type);
1283 if (ret < 0)
1284 return ret;
1285
1286 return count;
1287 }
1288
1289 return count;
1290}
1291
1292static int lowpan_control_show(struct seq_file *f, void *ptr)
1293{
1294 struct lowpan_dev *entry;
1295 struct lowpan_peer *peer;
1296
1297 spin_lock(&devices_lock);
1298
1299 list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1300 list_for_each_entry(peer, &entry->peers, list)
1301 seq_printf(f, "%pMR (type %u)\n",
1302 &peer->chan->dst, peer->chan->dst_type);
1303 }
1304
1305 spin_unlock(&devices_lock);
1306
1307 return 0;
1308}
1309
1310static int lowpan_control_open(struct inode *inode, struct file *file)
1311{
1312 return single_open(file, lowpan_control_show, inode->i_private);
1313}
1314
1315static const struct file_operations lowpan_control_fops = {
1316 .open = lowpan_control_open,
1317 .read = seq_read,
1318 .write = lowpan_control_write,
1319 .llseek = seq_lseek,
1320 .release = single_release,
1321};
1322
1323static void disconnect_devices(void)
1324{
1325 struct lowpan_dev *entry, *tmp, *new_dev;
1326 struct list_head devices;
1327
1328 INIT_LIST_HEAD(&devices);
1329
1330 /* We make a separate list of devices because the unregister_netdev()
1331 * will call device_event() which will also want to modify the same
1332 * devices list.
1333 */
1334
1335 rcu_read_lock();
1336
1337 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1338 new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC);
1339 if (!new_dev)
1340 break;
1341
1342 new_dev->netdev = entry->netdev;
1343 INIT_LIST_HEAD(&new_dev->list);
1344
1345 list_add_rcu(&new_dev->list, &devices);
1346 }
1347
1348 rcu_read_unlock();
1349
1350 list_for_each_entry_safe(entry, tmp, &devices, list) {
1351 ifdown(entry->netdev);
1352 BT_DBG("Unregistering netdev %s %p",
1353 entry->netdev->name, entry->netdev);
1354 lowpan_unregister_netdev(entry->netdev);
1355 kfree(entry);
1356 }
1357}
1358
1359static int device_event(struct notifier_block *unused,
1360 unsigned long event, void *ptr)
1361{
1362 struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
1363 struct lowpan_dev *entry;
1364
1365 if (netdev->type != ARPHRD_6LOWPAN)
1366 return NOTIFY_DONE;
1367
1368 switch (event) {
1369 case NETDEV_UNREGISTER:
1370 spin_lock(&devices_lock);
1371 list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1372 if (entry->netdev == netdev) {
1373 BT_DBG("Unregistered netdev %s %p",
1374 netdev->name, netdev);
1375 list_del(&entry->list);
1376 break;
1377 }
1378 }
1379 spin_unlock(&devices_lock);
1380 break;
1381 }
1382
1383 return NOTIFY_DONE;
1384}
1385
1386static struct notifier_block bt_6lowpan_dev_notifier = {
1387 .notifier_call = device_event,
1388};
1389
1390static int __init bt_6lowpan_init(void)
1391{
1392 lowpan_enable_debugfs = debugfs_create_file("6lowpan_enable", 0644,
1393 bt_debugfs, NULL,
1394 &lowpan_enable_fops);
1395 lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644,
1396 bt_debugfs, NULL,
1397 &lowpan_control_fops);
1398
1399 return register_netdevice_notifier(&bt_6lowpan_dev_notifier);
1400}
1401
1402static void __exit bt_6lowpan_exit(void)
1403{
1404 debugfs_remove(lowpan_enable_debugfs);
1405 debugfs_remove(lowpan_control_debugfs);
1406
1407 if (listen_chan) {
1408 l2cap_chan_close(listen_chan, 0);
1409 l2cap_chan_put(listen_chan);
1410 }
1411
1412 disconnect_devices();
1413
1414 unregister_netdevice_notifier(&bt_6lowpan_dev_notifier);
1415}
1416
1417module_init(bt_6lowpan_init);
1418module_exit(bt_6lowpan_exit);
1419
1420MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>");
1421MODULE_DESCRIPTION("Bluetooth 6LoWPAN");
1422MODULE_VERSION(VERSION);
1423MODULE_LICENSE("GPL");
1/*
2 Copyright (c) 2013 Intel Corp.
3
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License version 2 and
6 only version 2 as published by the Free Software Foundation.
7
8 This program is distributed in the hope that it will be useful,
9 but WITHOUT ANY WARRANTY; without even the implied warranty of
10 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 GNU General Public License for more details.
12*/
13
14#include <linux/if_arp.h>
15#include <linux/netdevice.h>
16#include <linux/etherdevice.h>
17
18#include <net/ipv6.h>
19#include <net/ip6_route.h>
20#include <net/addrconf.h>
21
22#include <net/af_ieee802154.h> /* to get the address type */
23
24#include <net/bluetooth/bluetooth.h>
25#include <net/bluetooth/hci_core.h>
26#include <net/bluetooth/l2cap.h>
27
28#include "6lowpan.h"
29
30#include <net/6lowpan.h> /* for the compression support */
31
32#define IFACE_NAME_TEMPLATE "bt%d"
33#define EUI64_ADDR_LEN 8
34
35struct skb_cb {
36 struct in6_addr addr;
37 struct l2cap_conn *conn;
38};
39#define lowpan_cb(skb) ((struct skb_cb *)((skb)->cb))
40
41/* The devices list contains those devices that we are acting
42 * as a proxy. The BT 6LoWPAN device is a virtual device that
43 * connects to the Bluetooth LE device. The real connection to
44 * BT device is done via l2cap layer. There exists one
45 * virtual device / one BT 6LoWPAN network (=hciX device).
46 * The list contains struct lowpan_dev elements.
47 */
48static LIST_HEAD(bt_6lowpan_devices);
49static DEFINE_RWLOCK(devices_lock);
50
51struct lowpan_peer {
52 struct list_head list;
53 struct l2cap_conn *conn;
54
55 /* peer addresses in various formats */
56 unsigned char eui64_addr[EUI64_ADDR_LEN];
57 struct in6_addr peer_addr;
58};
59
60struct lowpan_dev {
61 struct list_head list;
62
63 struct hci_dev *hdev;
64 struct net_device *netdev;
65 struct list_head peers;
66 atomic_t peer_count; /* number of items in peers list */
67
68 struct work_struct delete_netdev;
69 struct delayed_work notify_peers;
70};
71
72static inline struct lowpan_dev *lowpan_dev(const struct net_device *netdev)
73{
74 return netdev_priv(netdev);
75}
76
77static inline void peer_add(struct lowpan_dev *dev, struct lowpan_peer *peer)
78{
79 list_add(&peer->list, &dev->peers);
80 atomic_inc(&dev->peer_count);
81}
82
83static inline bool peer_del(struct lowpan_dev *dev, struct lowpan_peer *peer)
84{
85 list_del(&peer->list);
86
87 if (atomic_dec_and_test(&dev->peer_count)) {
88 BT_DBG("last peer");
89 return true;
90 }
91
92 return false;
93}
94
95static inline struct lowpan_peer *peer_lookup_ba(struct lowpan_dev *dev,
96 bdaddr_t *ba, __u8 type)
97{
98 struct lowpan_peer *peer, *tmp;
99
100 BT_DBG("peers %d addr %pMR type %d", atomic_read(&dev->peer_count),
101 ba, type);
102
103 list_for_each_entry_safe(peer, tmp, &dev->peers, list) {
104 BT_DBG("addr %pMR type %d",
105 &peer->conn->hcon->dst, peer->conn->hcon->dst_type);
106
107 if (bacmp(&peer->conn->hcon->dst, ba))
108 continue;
109
110 if (type == peer->conn->hcon->dst_type)
111 return peer;
112 }
113
114 return NULL;
115}
116
117static inline struct lowpan_peer *peer_lookup_conn(struct lowpan_dev *dev,
118 struct l2cap_conn *conn)
119{
120 struct lowpan_peer *peer, *tmp;
121
122 list_for_each_entry_safe(peer, tmp, &dev->peers, list) {
123 if (peer->conn == conn)
124 return peer;
125 }
126
127 return NULL;
128}
129
130static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn)
131{
132 struct lowpan_dev *entry, *tmp;
133 struct lowpan_peer *peer = NULL;
134 unsigned long flags;
135
136 read_lock_irqsave(&devices_lock, flags);
137
138 list_for_each_entry_safe(entry, tmp, &bt_6lowpan_devices, list) {
139 peer = peer_lookup_conn(entry, conn);
140 if (peer)
141 break;
142 }
143
144 read_unlock_irqrestore(&devices_lock, flags);
145
146 return peer;
147}
148
149static struct lowpan_dev *lookup_dev(struct l2cap_conn *conn)
150{
151 struct lowpan_dev *entry, *tmp;
152 struct lowpan_dev *dev = NULL;
153 unsigned long flags;
154
155 read_lock_irqsave(&devices_lock, flags);
156
157 list_for_each_entry_safe(entry, tmp, &bt_6lowpan_devices, list) {
158 if (conn->hcon->hdev == entry->hdev) {
159 dev = entry;
160 break;
161 }
162 }
163
164 read_unlock_irqrestore(&devices_lock, flags);
165
166 return dev;
167}
168
169static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev)
170{
171 struct sk_buff *skb_cp;
172 int ret;
173
174 skb_cp = skb_copy(skb, GFP_ATOMIC);
175 if (!skb_cp)
176 return -ENOMEM;
177
178 ret = netif_rx(skb_cp);
179
180 BT_DBG("receive skb %d", ret);
181 if (ret < 0)
182 return NET_RX_DROP;
183
184 return ret;
185}
186
187static int process_data(struct sk_buff *skb, struct net_device *netdev,
188 struct l2cap_conn *conn)
189{
190 const u8 *saddr, *daddr;
191 u8 iphc0, iphc1;
192 struct lowpan_dev *dev;
193 struct lowpan_peer *peer;
194 unsigned long flags;
195
196 dev = lowpan_dev(netdev);
197
198 read_lock_irqsave(&devices_lock, flags);
199 peer = peer_lookup_conn(dev, conn);
200 read_unlock_irqrestore(&devices_lock, flags);
201 if (!peer)
202 goto drop;
203
204 saddr = peer->eui64_addr;
205 daddr = dev->netdev->dev_addr;
206
207 /* at least two bytes will be used for the encoding */
208 if (skb->len < 2)
209 goto drop;
210
211 if (lowpan_fetch_skb_u8(skb, &iphc0))
212 goto drop;
213
214 if (lowpan_fetch_skb_u8(skb, &iphc1))
215 goto drop;
216
217 return lowpan_process_data(skb, netdev,
218 saddr, IEEE802154_ADDR_LONG, EUI64_ADDR_LEN,
219 daddr, IEEE802154_ADDR_LONG, EUI64_ADDR_LEN,
220 iphc0, iphc1, give_skb_to_upper);
221
222drop:
223 kfree_skb(skb);
224 return -EINVAL;
225}
226
227static int recv_pkt(struct sk_buff *skb, struct net_device *dev,
228 struct l2cap_conn *conn)
229{
230 struct sk_buff *local_skb;
231 int ret;
232
233 if (!netif_running(dev))
234 goto drop;
235
236 if (dev->type != ARPHRD_6LOWPAN)
237 goto drop;
238
239 /* check that it's our buffer */
240 if (skb->data[0] == LOWPAN_DISPATCH_IPV6) {
241 /* Copy the packet so that the IPv6 header is
242 * properly aligned.
243 */
244 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
245 skb_tailroom(skb), GFP_ATOMIC);
246 if (!local_skb)
247 goto drop;
248
249 local_skb->protocol = htons(ETH_P_IPV6);
250 local_skb->pkt_type = PACKET_HOST;
251
252 skb_reset_network_header(local_skb);
253 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
254
255 if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) {
256 kfree_skb(local_skb);
257 goto drop;
258 }
259
260 dev->stats.rx_bytes += skb->len;
261 dev->stats.rx_packets++;
262
263 kfree_skb(local_skb);
264 kfree_skb(skb);
265 } else {
266 switch (skb->data[0] & 0xe0) {
267 case LOWPAN_DISPATCH_IPHC: /* ipv6 datagram */
268 local_skb = skb_clone(skb, GFP_ATOMIC);
269 if (!local_skb)
270 goto drop;
271
272 ret = process_data(local_skb, dev, conn);
273 if (ret != NET_RX_SUCCESS)
274 goto drop;
275
276 dev->stats.rx_bytes += skb->len;
277 dev->stats.rx_packets++;
278
279 kfree_skb(skb);
280 break;
281 default:
282 break;
283 }
284 }
285
286 return NET_RX_SUCCESS;
287
288drop:
289 kfree_skb(skb);
290 return NET_RX_DROP;
291}
292
293/* Packet from BT LE device */
294int bt_6lowpan_recv(struct l2cap_conn *conn, struct sk_buff *skb)
295{
296 struct lowpan_dev *dev;
297 struct lowpan_peer *peer;
298 int err;
299
300 peer = lookup_peer(conn);
301 if (!peer)
302 return -ENOENT;
303
304 dev = lookup_dev(conn);
305 if (!dev || !dev->netdev)
306 return -ENOENT;
307
308 err = recv_pkt(skb, dev->netdev, conn);
309 BT_DBG("recv pkt %d", err);
310
311 return err;
312}
313
314static inline int skbuff_copy(void *msg, int len, int count, int mtu,
315 struct sk_buff *skb, struct net_device *dev)
316{
317 struct sk_buff **frag;
318 int sent = 0;
319
320 memcpy(skb_put(skb, count), msg, count);
321
322 sent += count;
323 msg += count;
324 len -= count;
325
326 dev->stats.tx_bytes += count;
327 dev->stats.tx_packets++;
328
329 raw_dump_table(__func__, "Sending", skb->data, skb->len);
330
331 /* Continuation fragments (no L2CAP header) */
332 frag = &skb_shinfo(skb)->frag_list;
333 while (len > 0) {
334 struct sk_buff *tmp;
335
336 count = min_t(unsigned int, mtu, len);
337
338 tmp = bt_skb_alloc(count, GFP_ATOMIC);
339 if (!tmp)
340 return -ENOMEM;
341
342 *frag = tmp;
343
344 memcpy(skb_put(*frag, count), msg, count);
345
346 raw_dump_table(__func__, "Sending fragment",
347 (*frag)->data, count);
348
349 (*frag)->priority = skb->priority;
350
351 sent += count;
352 msg += count;
353 len -= count;
354
355 skb->len += (*frag)->len;
356 skb->data_len += (*frag)->len;
357
358 frag = &(*frag)->next;
359
360 dev->stats.tx_bytes += count;
361 dev->stats.tx_packets++;
362 }
363
364 return sent;
365}
366
367static struct sk_buff *create_pdu(struct l2cap_conn *conn, void *msg,
368 size_t len, u32 priority,
369 struct net_device *dev)
370{
371 struct sk_buff *skb;
372 int err, count;
373 struct l2cap_hdr *lh;
374
375 /* FIXME: This mtu check should be not needed and atm is only used for
376 * testing purposes
377 */
378 if (conn->mtu > (L2CAP_LE_MIN_MTU + L2CAP_HDR_SIZE))
379 conn->mtu = L2CAP_LE_MIN_MTU + L2CAP_HDR_SIZE;
380
381 count = min_t(unsigned int, (conn->mtu - L2CAP_HDR_SIZE), len);
382
383 BT_DBG("conn %p len %zu mtu %d count %d", conn, len, conn->mtu, count);
384
385 skb = bt_skb_alloc(count + L2CAP_HDR_SIZE, GFP_ATOMIC);
386 if (!skb)
387 return ERR_PTR(-ENOMEM);
388
389 skb->priority = priority;
390
391 lh = (struct l2cap_hdr *)skb_put(skb, L2CAP_HDR_SIZE);
392 lh->cid = cpu_to_le16(L2CAP_FC_6LOWPAN);
393 lh->len = cpu_to_le16(len);
394
395 err = skbuff_copy(msg, len, count, conn->mtu, skb, dev);
396 if (unlikely(err < 0)) {
397 kfree_skb(skb);
398 BT_DBG("skbuff copy %d failed", err);
399 return ERR_PTR(err);
400 }
401
402 return skb;
403}
404
405static int conn_send(struct l2cap_conn *conn,
406 void *msg, size_t len, u32 priority,
407 struct net_device *dev)
408{
409 struct sk_buff *skb;
410
411 skb = create_pdu(conn, msg, len, priority, dev);
412 if (IS_ERR(skb))
413 return -EINVAL;
414
415 BT_DBG("conn %p skb %p len %d priority %u", conn, skb, skb->len,
416 skb->priority);
417
418 hci_send_acl(conn->hchan, skb, ACL_START);
419
420 return 0;
421}
422
423static void get_dest_bdaddr(struct in6_addr *ip6_daddr,
424 bdaddr_t *addr, u8 *addr_type)
425{
426 u8 *eui64;
427
428 eui64 = ip6_daddr->s6_addr + 8;
429
430 addr->b[0] = eui64[7];
431 addr->b[1] = eui64[6];
432 addr->b[2] = eui64[5];
433 addr->b[3] = eui64[2];
434 addr->b[4] = eui64[1];
435 addr->b[5] = eui64[0];
436
437 addr->b[5] ^= 2;
438
439 /* Set universal/local bit to 0 */
440 if (addr->b[5] & 1) {
441 addr->b[5] &= ~1;
442 *addr_type = ADDR_LE_DEV_PUBLIC;
443 } else {
444 *addr_type = ADDR_LE_DEV_RANDOM;
445 }
446}
447
448static int header_create(struct sk_buff *skb, struct net_device *netdev,
449 unsigned short type, const void *_daddr,
450 const void *_saddr, unsigned int len)
451{
452 struct ipv6hdr *hdr;
453 struct lowpan_dev *dev;
454 struct lowpan_peer *peer;
455 bdaddr_t addr, *any = BDADDR_ANY;
456 u8 *saddr, *daddr = any->b;
457 u8 addr_type;
458
459 if (type != ETH_P_IPV6)
460 return -EINVAL;
461
462 hdr = ipv6_hdr(skb);
463
464 dev = lowpan_dev(netdev);
465
466 if (ipv6_addr_is_multicast(&hdr->daddr)) {
467 memcpy(&lowpan_cb(skb)->addr, &hdr->daddr,
468 sizeof(struct in6_addr));
469 lowpan_cb(skb)->conn = NULL;
470 } else {
471 unsigned long flags;
472
473 /* Get destination BT device from skb.
474 * If there is no such peer then discard the packet.
475 */
476 get_dest_bdaddr(&hdr->daddr, &addr, &addr_type);
477
478 BT_DBG("dest addr %pMR type %d", &addr, addr_type);
479
480 read_lock_irqsave(&devices_lock, flags);
481 peer = peer_lookup_ba(dev, &addr, addr_type);
482 read_unlock_irqrestore(&devices_lock, flags);
483
484 if (!peer) {
485 BT_DBG("no such peer %pMR found", &addr);
486 return -ENOENT;
487 }
488
489 daddr = peer->eui64_addr;
490
491 memcpy(&lowpan_cb(skb)->addr, &hdr->daddr,
492 sizeof(struct in6_addr));
493 lowpan_cb(skb)->conn = peer->conn;
494 }
495
496 saddr = dev->netdev->dev_addr;
497
498 return lowpan_header_compress(skb, netdev, type, daddr, saddr, len);
499}
500
501/* Packet to BT LE device */
502static int send_pkt(struct l2cap_conn *conn, const void *saddr,
503 const void *daddr, struct sk_buff *skb,
504 struct net_device *netdev)
505{
506 raw_dump_table(__func__, "raw skb data dump before fragmentation",
507 skb->data, skb->len);
508
509 return conn_send(conn, skb->data, skb->len, 0, netdev);
510}
511
512static void send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev)
513{
514 struct sk_buff *local_skb;
515 struct lowpan_dev *entry, *tmp;
516 unsigned long flags;
517
518 read_lock_irqsave(&devices_lock, flags);
519
520 list_for_each_entry_safe(entry, tmp, &bt_6lowpan_devices, list) {
521 struct lowpan_peer *pentry, *ptmp;
522 struct lowpan_dev *dev;
523
524 if (entry->netdev != netdev)
525 continue;
526
527 dev = lowpan_dev(entry->netdev);
528
529 list_for_each_entry_safe(pentry, ptmp, &dev->peers, list) {
530 local_skb = skb_clone(skb, GFP_ATOMIC);
531
532 send_pkt(pentry->conn, netdev->dev_addr,
533 pentry->eui64_addr, local_skb, netdev);
534
535 kfree_skb(local_skb);
536 }
537 }
538
539 read_unlock_irqrestore(&devices_lock, flags);
540}
541
542static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev)
543{
544 int err = 0;
545 unsigned char *eui64_addr;
546 struct lowpan_dev *dev;
547 struct lowpan_peer *peer;
548 bdaddr_t addr;
549 u8 addr_type;
550
551 if (ipv6_addr_is_multicast(&lowpan_cb(skb)->addr)) {
552 /* We need to send the packet to every device
553 * behind this interface.
554 */
555 send_mcast_pkt(skb, netdev);
556 } else {
557 unsigned long flags;
558
559 get_dest_bdaddr(&lowpan_cb(skb)->addr, &addr, &addr_type);
560 eui64_addr = lowpan_cb(skb)->addr.s6_addr + 8;
561 dev = lowpan_dev(netdev);
562
563 read_lock_irqsave(&devices_lock, flags);
564 peer = peer_lookup_ba(dev, &addr, addr_type);
565 read_unlock_irqrestore(&devices_lock, flags);
566
567 BT_DBG("xmit from %s to %pMR (%pI6c) peer %p", netdev->name,
568 &addr, &lowpan_cb(skb)->addr, peer);
569
570 if (peer && peer->conn)
571 err = send_pkt(peer->conn, netdev->dev_addr,
572 eui64_addr, skb, netdev);
573 }
574 dev_kfree_skb(skb);
575
576 if (err)
577 BT_DBG("ERROR: xmit failed (%d)", err);
578
579 return (err < 0) ? NET_XMIT_DROP : err;
580}
581
582static const struct net_device_ops netdev_ops = {
583 .ndo_start_xmit = bt_xmit,
584};
585
586static struct header_ops header_ops = {
587 .create = header_create,
588};
589
590static void netdev_setup(struct net_device *dev)
591{
592 dev->addr_len = EUI64_ADDR_LEN;
593 dev->type = ARPHRD_6LOWPAN;
594
595 dev->hard_header_len = 0;
596 dev->needed_tailroom = 0;
597 dev->mtu = IPV6_MIN_MTU;
598 dev->tx_queue_len = 0;
599 dev->flags = IFF_RUNNING | IFF_POINTOPOINT;
600 dev->watchdog_timeo = 0;
601
602 dev->netdev_ops = &netdev_ops;
603 dev->header_ops = &header_ops;
604 dev->destructor = free_netdev;
605}
606
607static struct device_type bt_type = {
608 .name = "bluetooth",
609};
610
611static void set_addr(u8 *eui, u8 *addr, u8 addr_type)
612{
613 /* addr is the BT address in little-endian format */
614 eui[0] = addr[5];
615 eui[1] = addr[4];
616 eui[2] = addr[3];
617 eui[3] = 0xFF;
618 eui[4] = 0xFE;
619 eui[5] = addr[2];
620 eui[6] = addr[1];
621 eui[7] = addr[0];
622
623 eui[0] ^= 2;
624
625 /* Universal/local bit set, RFC 4291 */
626 if (addr_type == ADDR_LE_DEV_PUBLIC)
627 eui[0] |= 1;
628 else
629 eui[0] &= ~1;
630}
631
632static void set_dev_addr(struct net_device *netdev, bdaddr_t *addr,
633 u8 addr_type)
634{
635 netdev->addr_assign_type = NET_ADDR_PERM;
636 set_addr(netdev->dev_addr, addr->b, addr_type);
637 netdev->dev_addr[0] ^= 2;
638}
639
640static void ifup(struct net_device *netdev)
641{
642 int err;
643
644 rtnl_lock();
645 err = dev_open(netdev);
646 if (err < 0)
647 BT_INFO("iface %s cannot be opened (%d)", netdev->name, err);
648 rtnl_unlock();
649}
650
651static void do_notify_peers(struct work_struct *work)
652{
653 struct lowpan_dev *dev = container_of(work, struct lowpan_dev,
654 notify_peers.work);
655
656 netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */
657}
658
659static bool is_bt_6lowpan(struct hci_conn *hcon)
660{
661 if (hcon->type != LE_LINK)
662 return false;
663
664 return test_bit(HCI_CONN_6LOWPAN, &hcon->flags);
665}
666
667static int add_peer_conn(struct l2cap_conn *conn, struct lowpan_dev *dev)
668{
669 struct lowpan_peer *peer;
670 unsigned long flags;
671
672 peer = kzalloc(sizeof(*peer), GFP_ATOMIC);
673 if (!peer)
674 return -ENOMEM;
675
676 peer->conn = conn;
677 memset(&peer->peer_addr, 0, sizeof(struct in6_addr));
678
679 /* RFC 2464 ch. 5 */
680 peer->peer_addr.s6_addr[0] = 0xFE;
681 peer->peer_addr.s6_addr[1] = 0x80;
682 set_addr((u8 *)&peer->peer_addr.s6_addr + 8, conn->hcon->dst.b,
683 conn->hcon->dst_type);
684
685 memcpy(&peer->eui64_addr, (u8 *)&peer->peer_addr.s6_addr + 8,
686 EUI64_ADDR_LEN);
687 peer->eui64_addr[0] ^= 2; /* second bit-flip (Universe/Local)
688 * is done according RFC2464
689 */
690
691 raw_dump_inline(__func__, "peer IPv6 address",
692 (unsigned char *)&peer->peer_addr, 16);
693 raw_dump_inline(__func__, "peer EUI64 address", peer->eui64_addr, 8);
694
695 write_lock_irqsave(&devices_lock, flags);
696 INIT_LIST_HEAD(&peer->list);
697 peer_add(dev, peer);
698 write_unlock_irqrestore(&devices_lock, flags);
699
700 /* Notifying peers about us needs to be done without locks held */
701 INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers);
702 schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100));
703
704 return 0;
705}
706
707/* This gets called when BT LE 6LoWPAN device is connected. We then
708 * create network device that acts as a proxy between BT LE device
709 * and kernel network stack.
710 */
711int bt_6lowpan_add_conn(struct l2cap_conn *conn)
712{
713 struct lowpan_peer *peer = NULL;
714 struct lowpan_dev *dev;
715 struct net_device *netdev;
716 int err = 0;
717 unsigned long flags;
718
719 if (!is_bt_6lowpan(conn->hcon))
720 return 0;
721
722 peer = lookup_peer(conn);
723 if (peer)
724 return -EEXIST;
725
726 dev = lookup_dev(conn);
727 if (dev)
728 return add_peer_conn(conn, dev);
729
730 netdev = alloc_netdev(sizeof(*dev), IFACE_NAME_TEMPLATE, netdev_setup);
731 if (!netdev)
732 return -ENOMEM;
733
734 set_dev_addr(netdev, &conn->hcon->src, conn->hcon->src_type);
735
736 netdev->netdev_ops = &netdev_ops;
737 SET_NETDEV_DEV(netdev, &conn->hcon->dev);
738 SET_NETDEV_DEVTYPE(netdev, &bt_type);
739
740 err = register_netdev(netdev);
741 if (err < 0) {
742 BT_INFO("register_netdev failed %d", err);
743 free_netdev(netdev);
744 goto out;
745 }
746
747 BT_DBG("ifindex %d peer bdaddr %pMR my addr %pMR",
748 netdev->ifindex, &conn->hcon->dst, &conn->hcon->src);
749 set_bit(__LINK_STATE_PRESENT, &netdev->state);
750
751 dev = netdev_priv(netdev);
752 dev->netdev = netdev;
753 dev->hdev = conn->hcon->hdev;
754 INIT_LIST_HEAD(&dev->peers);
755
756 write_lock_irqsave(&devices_lock, flags);
757 INIT_LIST_HEAD(&dev->list);
758 list_add(&dev->list, &bt_6lowpan_devices);
759 write_unlock_irqrestore(&devices_lock, flags);
760
761 ifup(netdev);
762
763 return add_peer_conn(conn, dev);
764
765out:
766 return err;
767}
768
769static void delete_netdev(struct work_struct *work)
770{
771 struct lowpan_dev *entry = container_of(work, struct lowpan_dev,
772 delete_netdev);
773
774 unregister_netdev(entry->netdev);
775
776 /* The entry pointer is deleted in device_event() */
777}
778
779int bt_6lowpan_del_conn(struct l2cap_conn *conn)
780{
781 struct lowpan_dev *entry, *tmp;
782 struct lowpan_dev *dev = NULL;
783 struct lowpan_peer *peer;
784 int err = -ENOENT;
785 unsigned long flags;
786 bool last = false;
787
788 if (!conn || !is_bt_6lowpan(conn->hcon))
789 return 0;
790
791 write_lock_irqsave(&devices_lock, flags);
792
793 list_for_each_entry_safe(entry, tmp, &bt_6lowpan_devices, list) {
794 dev = lowpan_dev(entry->netdev);
795 peer = peer_lookup_conn(dev, conn);
796 if (peer) {
797 last = peer_del(dev, peer);
798 err = 0;
799 break;
800 }
801 }
802
803 if (!err && last && dev && !atomic_read(&dev->peer_count)) {
804 write_unlock_irqrestore(&devices_lock, flags);
805
806 cancel_delayed_work_sync(&dev->notify_peers);
807
808 /* bt_6lowpan_del_conn() is called with hci dev lock held which
809 * means that we must delete the netdevice in worker thread.
810 */
811 INIT_WORK(&entry->delete_netdev, delete_netdev);
812 schedule_work(&entry->delete_netdev);
813 } else {
814 write_unlock_irqrestore(&devices_lock, flags);
815 }
816
817 return err;
818}
819
820static int device_event(struct notifier_block *unused,
821 unsigned long event, void *ptr)
822{
823 struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
824 struct lowpan_dev *entry, *tmp;
825 unsigned long flags;
826
827 if (netdev->type != ARPHRD_6LOWPAN)
828 return NOTIFY_DONE;
829
830 switch (event) {
831 case NETDEV_UNREGISTER:
832 write_lock_irqsave(&devices_lock, flags);
833 list_for_each_entry_safe(entry, tmp, &bt_6lowpan_devices,
834 list) {
835 if (entry->netdev == netdev) {
836 list_del(&entry->list);
837 kfree(entry);
838 break;
839 }
840 }
841 write_unlock_irqrestore(&devices_lock, flags);
842 break;
843 }
844
845 return NOTIFY_DONE;
846}
847
848static struct notifier_block bt_6lowpan_dev_notifier = {
849 .notifier_call = device_event,
850};
851
852int bt_6lowpan_init(void)
853{
854 return register_netdevice_notifier(&bt_6lowpan_dev_notifier);
855}
856
857void bt_6lowpan_cleanup(void)
858{
859 unregister_netdevice_notifier(&bt_6lowpan_dev_notifier);
860}