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Merge tag 'iommu-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
[linux/fpc-iii.git] / net / bluetooth / 6lowpan.c
blobcff4944d5b6637d18388321023d55c07b19e2d38
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 Copyright (c) 2013-2014 Intel Corp.
4
5 */
6
7 #include <linux/if_arp.h>
8 #include <linux/netdevice.h>
9 #include <linux/etherdevice.h>
10 #include <linux/module.h>
11 #include <linux/debugfs.h>
12
13 #include <net/ipv6.h>
14 #include <net/ip6_route.h>
15 #include <net/addrconf.h>
16 #include <net/pkt_sched.h>
17
18 #include <net/bluetooth/bluetooth.h>
19 #include <net/bluetooth/hci_core.h>
20 #include <net/bluetooth/l2cap.h>
21
22 #include <net/6lowpan.h> /* for the compression support */
23
24 #define VERSION "0.1"
25
26 static struct dentry *lowpan_enable_debugfs;
27 static struct dentry *lowpan_control_debugfs;
28
29 #define IFACE_NAME_TEMPLATE "bt%d"
30
31 struct skb_cb {
32 struct in6_addr addr;
33 struct in6_addr gw;
34 struct l2cap_chan *chan;
35 };
36 #define lowpan_cb(skb) ((struct skb_cb *)((skb)->cb))
37
38 /* The devices list contains those devices that we are acting
39 * as a proxy. The BT 6LoWPAN device is a virtual device that
40 * connects to the Bluetooth LE device. The real connection to
41 * BT device is done via l2cap layer. There exists one
42 * virtual device / one BT 6LoWPAN network (=hciX device).
43 * The list contains struct lowpan_dev elements.
44 */
45 static LIST_HEAD(bt_6lowpan_devices);
46 static DEFINE_SPINLOCK(devices_lock);
47
48 static bool enable_6lowpan;
49
50 /* We are listening incoming connections via this channel
51 */
52 static struct l2cap_chan *listen_chan;
53 static DEFINE_MUTEX(set_lock);
54
55 struct lowpan_peer {
56 struct list_head list;
57 struct rcu_head rcu;
58 struct l2cap_chan *chan;
59
60 /* peer addresses in various formats */
61 unsigned char lladdr[ETH_ALEN];
62 struct in6_addr peer_addr;
63 };
64
65 struct lowpan_btle_dev {
66 struct list_head list;
67
68 struct hci_dev *hdev;
69 struct net_device *netdev;
70 struct list_head peers;
71 atomic_t peer_count; /* number of items in peers list */
72
73 struct work_struct delete_netdev;
74 struct delayed_work notify_peers;
75 };
76
77 static inline struct lowpan_btle_dev *
78 lowpan_btle_dev(const struct net_device *netdev)
79 {
80 return (struct lowpan_btle_dev *)lowpan_dev(netdev)->priv;
81 }
82
83 static inline void peer_add(struct lowpan_btle_dev *dev,
84 struct lowpan_peer *peer)
85 {
86 list_add_rcu(&peer->list, &dev->peers);
87 atomic_inc(&dev->peer_count);
88 }
89
90 static inline bool peer_del(struct lowpan_btle_dev *dev,
91 struct lowpan_peer *peer)
92 {
93 list_del_rcu(&peer->list);
94 kfree_rcu(peer, rcu);
95
96 module_put(THIS_MODULE);
97
98 if (atomic_dec_and_test(&dev->peer_count)) {
99 BT_DBG("last peer");
100 return true;
101 }
102
103 return false;
104 }
105
106 static inline struct lowpan_peer *peer_lookup_ba(struct lowpan_btle_dev *dev,
107 bdaddr_t *ba, __u8 type)
108 {
109 struct lowpan_peer *peer;
110
111 BT_DBG("peers %d addr %pMR type %d", atomic_read(&dev->peer_count),
112 ba, type);
113
114 rcu_read_lock();
115
116 list_for_each_entry_rcu(peer, &dev->peers, list) {
117 BT_DBG("dst addr %pMR dst type %d",
118 &peer->chan->dst, peer->chan->dst_type);
119
120 if (bacmp(&peer->chan->dst, ba))
121 continue;
122
123 if (type == peer->chan->dst_type) {
124 rcu_read_unlock();
125 return peer;
126 }
127 }
128
129 rcu_read_unlock();
130
131 return NULL;
132 }
133
134 static inline struct lowpan_peer *
135 __peer_lookup_chan(struct lowpan_btle_dev *dev, struct l2cap_chan *chan)
136 {
137 struct lowpan_peer *peer;
138
139 list_for_each_entry_rcu(peer, &dev->peers, list) {
140 if (peer->chan == chan)
141 return peer;
142 }
143
144 return NULL;
145 }
146
147 static inline struct lowpan_peer *
148 __peer_lookup_conn(struct lowpan_btle_dev *dev, struct l2cap_conn *conn)
149 {
150 struct lowpan_peer *peer;
151
152 list_for_each_entry_rcu(peer, &dev->peers, list) {
153 if (peer->chan->conn == conn)
154 return peer;
155 }
156
157 return NULL;
158 }
159
160 static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_btle_dev *dev,
161 struct in6_addr *daddr,
162 struct sk_buff *skb)
163 {
164 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
165 int count = atomic_read(&dev->peer_count);
166 const struct in6_addr *nexthop;
167 struct lowpan_peer *peer;
168 struct neighbour *neigh;
169
170 BT_DBG("peers %d addr %pI6c rt %p", count, daddr, rt);
171
172 if (!rt) {
173 if (ipv6_addr_any(&lowpan_cb(skb)->gw)) {
174 /* There is neither route nor gateway,
175 * probably the destination is a direct peer.
176 */
177 nexthop = daddr;
178 } else {
179 /* There is a known gateway
180 */
181 nexthop = &lowpan_cb(skb)->gw;
182 }
183 } else {
184 nexthop = rt6_nexthop(rt, daddr);
185
186 /* We need to remember the address because it is needed
187 * by bt_xmit() when sending the packet. In bt_xmit(), the
188 * destination routing info is not set.
189 */
190 memcpy(&lowpan_cb(skb)->gw, nexthop, sizeof(struct in6_addr));
191 }
192
193 BT_DBG("gw %pI6c", nexthop);
194
195 rcu_read_lock();
196
197 list_for_each_entry_rcu(peer, &dev->peers, list) {
198 BT_DBG("dst addr %pMR dst type %d ip %pI6c",
199 &peer->chan->dst, peer->chan->dst_type,
200 &peer->peer_addr);
201
202 if (!ipv6_addr_cmp(&peer->peer_addr, nexthop)) {
203 rcu_read_unlock();
204 return peer;
205 }
206 }
207
208 /* use the neighbour cache for matching addresses assigned by SLAAC
209 */
210 neigh = __ipv6_neigh_lookup(dev->netdev, nexthop);
211 if (neigh) {
212 list_for_each_entry_rcu(peer, &dev->peers, list) {
213 if (!memcmp(neigh->ha, peer->lladdr, ETH_ALEN)) {
214 neigh_release(neigh);
215 rcu_read_unlock();
216 return peer;
217 }
218 }
219 neigh_release(neigh);
220 }
221
222 rcu_read_unlock();
223
224 return NULL;
225 }
226
227 static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn)
228 {
229 struct lowpan_btle_dev *entry;
230 struct lowpan_peer *peer = NULL;
231
232 rcu_read_lock();
233
234 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
235 peer = __peer_lookup_conn(entry, conn);
236 if (peer)
237 break;
238 }
239
240 rcu_read_unlock();
241
242 return peer;
243 }
244
245 static struct lowpan_btle_dev *lookup_dev(struct l2cap_conn *conn)
246 {
247 struct lowpan_btle_dev *entry;
248 struct lowpan_btle_dev *dev = NULL;
249
250 rcu_read_lock();
251
252 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
253 if (conn->hcon->hdev == entry->hdev) {
254 dev = entry;
255 break;
256 }
257 }
258
259 rcu_read_unlock();
260
261 return dev;
262 }
263
264 static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev)
265 {
266 struct sk_buff *skb_cp;
267
268 skb_cp = skb_copy(skb, GFP_ATOMIC);
269 if (!skb_cp)
270 return NET_RX_DROP;
271
272 return netif_rx_ni(skb_cp);
273 }
274
275 static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev,
276 struct lowpan_peer *peer)
277 {
278 const u8 *saddr;
279
280 saddr = peer->lladdr;
281
282 return lowpan_header_decompress(skb, netdev, netdev->dev_addr, saddr);
283 }
284
285 static int recv_pkt(struct sk_buff *skb, struct net_device *dev,
286 struct lowpan_peer *peer)
287 {
288 struct sk_buff *local_skb;
289 int ret;
290
291 if (!netif_running(dev))
292 goto drop;
293
294 if (dev->type != ARPHRD_6LOWPAN || !skb->len)
295 goto drop;
296
297 skb_reset_network_header(skb);
298
299 skb = skb_share_check(skb, GFP_ATOMIC);
300 if (!skb)
301 goto drop;
302
303 /* check that it's our buffer */
304 if (lowpan_is_ipv6(*skb_network_header(skb))) {
305 /* Pull off the 1-byte of 6lowpan header. */
306 skb_pull(skb, 1);
307
308 /* Copy the packet so that the IPv6 header is
309 * properly aligned.
310 */
311 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
312 skb_tailroom(skb), GFP_ATOMIC);
313 if (!local_skb)
314 goto drop;
315
316 local_skb->protocol = htons(ETH_P_IPV6);
317 local_skb->pkt_type = PACKET_HOST;
318 local_skb->dev = dev;
319
320 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
321
322 if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) {
323 kfree_skb(local_skb);
324 goto drop;
325 }
326
327 dev->stats.rx_bytes += skb->len;
328 dev->stats.rx_packets++;
329
330 consume_skb(local_skb);
331 consume_skb(skb);
332 } else if (lowpan_is_iphc(*skb_network_header(skb))) {
333 local_skb = skb_clone(skb, GFP_ATOMIC);
334 if (!local_skb)
335 goto drop;
336
337 local_skb->dev = dev;
338
339 ret = iphc_decompress(local_skb, dev, peer);
340 if (ret < 0) {
341 BT_DBG("iphc_decompress failed: %d", ret);
342 kfree_skb(local_skb);
343 goto drop;
344 }
345
346 local_skb->protocol = htons(ETH_P_IPV6);
347 local_skb->pkt_type = PACKET_HOST;
348
349 if (give_skb_to_upper(local_skb, dev)
350 != NET_RX_SUCCESS) {
351 kfree_skb(local_skb);
352 goto drop;
353 }
354
355 dev->stats.rx_bytes += skb->len;
356 dev->stats.rx_packets++;
357
358 consume_skb(local_skb);
359 consume_skb(skb);
360 } else {
361 BT_DBG("unknown packet type");
362 goto drop;
363 }
364
365 return NET_RX_SUCCESS;
366
367 drop:
368 dev->stats.rx_dropped++;
369 return NET_RX_DROP;
370 }
371
372 /* Packet from BT LE device */
373 static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
374 {
375 struct lowpan_btle_dev *dev;
376 struct lowpan_peer *peer;
377 int err;
378
379 peer = lookup_peer(chan->conn);
380 if (!peer)
381 return -ENOENT;
382
383 dev = lookup_dev(chan->conn);
384 if (!dev || !dev->netdev)
385 return -ENOENT;
386
387 err = recv_pkt(skb, dev->netdev, peer);
388 if (err) {
389 BT_DBG("recv pkt %d", err);
390 err = -EAGAIN;
391 }
392
393 return err;
394 }
395
396 static int setup_header(struct sk_buff *skb, struct net_device *netdev,
397 bdaddr_t *peer_addr, u8 *peer_addr_type)
398 {
399 struct in6_addr ipv6_daddr;
400 struct ipv6hdr *hdr;
401 struct lowpan_btle_dev *dev;
402 struct lowpan_peer *peer;
403 u8 *daddr;
404 int err, status = 0;
405
406 hdr = ipv6_hdr(skb);
407
408 dev = lowpan_btle_dev(netdev);
409
410 memcpy(&ipv6_daddr, &hdr->daddr, sizeof(ipv6_daddr));
411
412 if (ipv6_addr_is_multicast(&ipv6_daddr)) {
413 lowpan_cb(skb)->chan = NULL;
414 daddr = NULL;
415 } else {
416 BT_DBG("dest IP %pI6c", &ipv6_daddr);
417
418 /* The packet might be sent to 6lowpan interface
419 * because of routing (either via default route
420 * or user set route) so get peer according to
421 * the destination address.
422 */
423 peer = peer_lookup_dst(dev, &ipv6_daddr, skb);
424 if (!peer) {
425 BT_DBG("no such peer");
426 return -ENOENT;
427 }
428
429 daddr = peer->lladdr;
430 *peer_addr = peer->chan->dst;
431 *peer_addr_type = peer->chan->dst_type;
432 lowpan_cb(skb)->chan = peer->chan;
433
434 status = 1;
435 }
436
437 lowpan_header_compress(skb, netdev, daddr, dev->netdev->dev_addr);
438
439 err = dev_hard_header(skb, netdev, ETH_P_IPV6, NULL, NULL, 0);
440 if (err < 0)
441 return err;
442
443 return status;
444 }
445
446 static int header_create(struct sk_buff *skb, struct net_device *netdev,
447 unsigned short type, const void *_daddr,
448 const void *_saddr, unsigned int len)
449 {
450 if (type != ETH_P_IPV6)
451 return -EINVAL;
452
453 return 0;
454 }
455
456 /* Packet to BT LE device */
457 static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb,
458 struct net_device *netdev)
459 {
460 struct msghdr msg;
461 struct kvec iv;
462 int err;
463
464 /* Remember the skb so that we can send EAGAIN to the caller if
465 * we run out of credits.
466 */
467 chan->data = skb;
468
469 iv.iov_base = skb->data;
470 iv.iov_len = skb->len;
471
472 memset(&msg, 0, sizeof(msg));
473 iov_iter_kvec(&msg.msg_iter, WRITE, &iv, 1, skb->len);
474
475 err = l2cap_chan_send(chan, &msg, skb->len);
476 if (err > 0) {
477 netdev->stats.tx_bytes += err;
478 netdev->stats.tx_packets++;
479 return 0;
480 }
481
482 if (err < 0)
483 netdev->stats.tx_errors++;
484
485 return err;
486 }
487
488 static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev)
489 {
490 struct sk_buff *local_skb;
491 struct lowpan_btle_dev *entry;
492 int err = 0;
493
494 rcu_read_lock();
495
496 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
497 struct lowpan_peer *pentry;
498 struct lowpan_btle_dev *dev;
499
500 if (entry->netdev != netdev)
501 continue;
502
503 dev = lowpan_btle_dev(entry->netdev);
504
505 list_for_each_entry_rcu(pentry, &dev->peers, list) {
506 int ret;
507
508 local_skb = skb_clone(skb, GFP_ATOMIC);
509
510 BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
511 netdev->name,
512 &pentry->chan->dst, pentry->chan->dst_type,
513 &pentry->peer_addr, pentry->chan);
514 ret = send_pkt(pentry->chan, local_skb, netdev);
515 if (ret < 0)
516 err = ret;
517
518 kfree_skb(local_skb);
519 }
520 }
521
522 rcu_read_unlock();
523
524 return err;
525 }
526
527 static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev)
528 {
529 int err = 0;
530 bdaddr_t addr;
531 u8 addr_type;
532
533 /* We must take a copy of the skb before we modify/replace the ipv6
534 * header as the header could be used elsewhere
535 */
536 skb = skb_unshare(skb, GFP_ATOMIC);
537 if (!skb)
538 return NET_XMIT_DROP;
539
540 /* Return values from setup_header()
541 * <0 - error, packet is dropped
542 * 0 - this is a multicast packet
543 * 1 - this is unicast packet
544 */
545 err = setup_header(skb, netdev, &addr, &addr_type);
546 if (err < 0) {
547 kfree_skb(skb);
548 return NET_XMIT_DROP;
549 }
550
551 if (err) {
552 if (lowpan_cb(skb)->chan) {
553 BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
554 netdev->name, &addr, addr_type,
555 &lowpan_cb(skb)->addr, lowpan_cb(skb)->chan);
556 err = send_pkt(lowpan_cb(skb)->chan, skb, netdev);
557 } else {
558 err = -ENOENT;
559 }
560 } else {
561 /* We need to send the packet to every device behind this
562 * interface.
563 */
564 err = send_mcast_pkt(skb, netdev);
565 }
566
567 dev_kfree_skb(skb);
568
569 if (err)
570 BT_DBG("ERROR: xmit failed (%d)", err);
571
572 return err < 0 ? NET_XMIT_DROP : err;
573 }
574
575 static int bt_dev_init(struct net_device *dev)
576 {
577 netdev_lockdep_set_classes(dev);
578
579 return 0;
580 }
581
582 static const struct net_device_ops netdev_ops = {
583 .ndo_init = bt_dev_init,
584 .ndo_start_xmit = bt_xmit,
585 };
586
587 static const struct header_ops header_ops = {
588 .create = header_create,
589 };
590
591 static void netdev_setup(struct net_device *dev)
592 {
593 dev->hard_header_len = 0;
594 dev->needed_tailroom = 0;
595 dev->flags = IFF_RUNNING | IFF_MULTICAST;
596 dev->watchdog_timeo = 0;
597 dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
598
599 dev->netdev_ops = &netdev_ops;
600 dev->header_ops = &header_ops;
601 dev->needs_free_netdev = true;
602 }
603
604 static struct device_type bt_type = {
605 .name = "bluetooth",
606 };
607
608 static void ifup(struct net_device *netdev)
609 {
610 int err;
611
612 rtnl_lock();
613 err = dev_open(netdev, NULL);
614 if (err < 0)
615 BT_INFO("iface %s cannot be opened (%d)", netdev->name, err);
616 rtnl_unlock();
617 }
618
619 static void ifdown(struct net_device *netdev)
620 {
621 rtnl_lock();
622 dev_close(netdev);
623 rtnl_unlock();
624 }
625
626 static void do_notify_peers(struct work_struct *work)
627 {
628 struct lowpan_btle_dev *dev = container_of(work, struct lowpan_btle_dev,
629 notify_peers.work);
630
631 netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */
632 }
633
634 static bool is_bt_6lowpan(struct hci_conn *hcon)
635 {
636 if (hcon->type != LE_LINK)
637 return false;
638
639 if (!enable_6lowpan)
640 return false;
641
642 return true;
643 }
644
645 static struct l2cap_chan *chan_create(void)
646 {
647 struct l2cap_chan *chan;
648
649 chan = l2cap_chan_create();
650 if (!chan)
651 return NULL;
652
653 l2cap_chan_set_defaults(chan);
654
655 chan->chan_type = L2CAP_CHAN_CONN_ORIENTED;
656 chan->mode = L2CAP_MODE_LE_FLOWCTL;
657 chan->imtu = 1280;
658
659 return chan;
660 }
661
662 static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan,
663 struct lowpan_btle_dev *dev,
664 bool new_netdev)
665 {
666 struct lowpan_peer *peer;
667
668 peer = kzalloc(sizeof(*peer), GFP_ATOMIC);
669 if (!peer)
670 return NULL;
671
672 peer->chan = chan;
673 memset(&peer->peer_addr, 0, sizeof(struct in6_addr));
674
675 baswap((void *)peer->lladdr, &chan->dst);
676
677 lowpan_iphc_uncompress_eui48_lladdr(&peer->peer_addr, peer->lladdr);
678
679 spin_lock(&devices_lock);
680 INIT_LIST_HEAD(&peer->list);
681 peer_add(dev, peer);
682 spin_unlock(&devices_lock);
683
684 /* Notifying peers about us needs to be done without locks held */
685 if (new_netdev)
686 INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers);
687 schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100));
688
689 return peer->chan;
690 }
691
692 static int setup_netdev(struct l2cap_chan *chan, struct lowpan_btle_dev **dev)
693 {
694 struct net_device *netdev;
695 int err = 0;
696
697 netdev = alloc_netdev(LOWPAN_PRIV_SIZE(sizeof(struct lowpan_btle_dev)),
698 IFACE_NAME_TEMPLATE, NET_NAME_UNKNOWN,
699 netdev_setup);
700 if (!netdev)
701 return -ENOMEM;
702
703 netdev->addr_assign_type = NET_ADDR_PERM;
704 baswap((void *)netdev->dev_addr, &chan->src);
705
706 netdev->netdev_ops = &netdev_ops;
707 SET_NETDEV_DEV(netdev, &chan->conn->hcon->hdev->dev);
708 SET_NETDEV_DEVTYPE(netdev, &bt_type);
709
710 *dev = lowpan_btle_dev(netdev);
711 (*dev)->netdev = netdev;
712 (*dev)->hdev = chan->conn->hcon->hdev;
713 INIT_LIST_HEAD(&(*dev)->peers);
714
715 spin_lock(&devices_lock);
716 INIT_LIST_HEAD(&(*dev)->list);
717 list_add_rcu(&(*dev)->list, &bt_6lowpan_devices);
718 spin_unlock(&devices_lock);
719
720 err = lowpan_register_netdev(netdev, LOWPAN_LLTYPE_BTLE);
721 if (err < 0) {
722 BT_INFO("register_netdev failed %d", err);
723 spin_lock(&devices_lock);
724 list_del_rcu(&(*dev)->list);
725 spin_unlock(&devices_lock);
726 free_netdev(netdev);
727 goto out;
728 }
729
730 BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d",
731 netdev->ifindex, &chan->dst, chan->dst_type,
732 &chan->src, chan->src_type);
733 set_bit(__LINK_STATE_PRESENT, &netdev->state);
734
735 return 0;
736
737 out:
738 return err;
739 }
740
741 static inline void chan_ready_cb(struct l2cap_chan *chan)
742 {
743 struct lowpan_btle_dev *dev;
744 bool new_netdev = false;
745
746 dev = lookup_dev(chan->conn);
747
748 BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev);
749
750 if (!dev) {
751 if (setup_netdev(chan, &dev) < 0) {
752 l2cap_chan_del(chan, -ENOENT);
753 return;
754 }
755 new_netdev = true;
756 }
757
758 if (!try_module_get(THIS_MODULE))
759 return;
760
761 add_peer_chan(chan, dev, new_netdev);
762 ifup(dev->netdev);
763 }
764
765 static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan)
766 {
767 struct l2cap_chan *chan;
768
769 chan = chan_create();
770 if (!chan)
771 return NULL;
772
773 chan->ops = pchan->ops;
774
775 BT_DBG("chan %p pchan %p", chan, pchan);
776
777 return chan;
778 }
779
780 static void delete_netdev(struct work_struct *work)
781 {
782 struct lowpan_btle_dev *entry = container_of(work,
783 struct lowpan_btle_dev,
784 delete_netdev);
785
786 lowpan_unregister_netdev(entry->netdev);
787
788 /* The entry pointer is deleted by the netdev destructor. */
789 }
790
791 static void chan_close_cb(struct l2cap_chan *chan)
792 {
793 struct lowpan_btle_dev *entry;
794 struct lowpan_btle_dev *dev = NULL;
795 struct lowpan_peer *peer;
796 int err = -ENOENT;
797 bool last = false, remove = true;
798
799 BT_DBG("chan %p conn %p", chan, chan->conn);
800
801 if (chan->conn && chan->conn->hcon) {
802 if (!is_bt_6lowpan(chan->conn->hcon))
803 return;
804
805 /* If conn is set, then the netdev is also there and we should
806 * not remove it.
807 */
808 remove = false;
809 }
810
811 spin_lock(&devices_lock);
812
813 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
814 dev = lowpan_btle_dev(entry->netdev);
815 peer = __peer_lookup_chan(dev, chan);
816 if (peer) {
817 last = peer_del(dev, peer);
818 err = 0;
819
820 BT_DBG("dev %p removing %speer %p", dev,
821 last ? "last " : "1 ", peer);
822 BT_DBG("chan %p orig refcnt %d", chan,
823 kref_read(&chan->kref));
824
825 l2cap_chan_put(chan);
826 break;
827 }
828 }
829
830 if (!err && last && dev && !atomic_read(&dev->peer_count)) {
831 spin_unlock(&devices_lock);
832
833 cancel_delayed_work_sync(&dev->notify_peers);
834
835 ifdown(dev->netdev);
836
837 if (remove) {
838 INIT_WORK(&entry->delete_netdev, delete_netdev);
839 schedule_work(&entry->delete_netdev);
840 }
841 } else {
842 spin_unlock(&devices_lock);
843 }
844
845 return;
846 }
847
848 static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err)
849 {
850 BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn,
851 state_to_string(state), err);
852 }
853
854 static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan,
855 unsigned long hdr_len,
856 unsigned long len, int nb)
857 {
858 /* Note that we must allocate using GFP_ATOMIC here as
859 * this function is called originally from netdev hard xmit
860 * function in atomic context.
861 */
862 return bt_skb_alloc(hdr_len + len, GFP_ATOMIC);
863 }
864
865 static void chan_suspend_cb(struct l2cap_chan *chan)
866 {
867 struct lowpan_btle_dev *dev;
868
869 BT_DBG("chan %p suspend", chan);
870
871 dev = lookup_dev(chan->conn);
872 if (!dev || !dev->netdev)
873 return;
874
875 netif_stop_queue(dev->netdev);
876 }
877
878 static void chan_resume_cb(struct l2cap_chan *chan)
879 {
880 struct lowpan_btle_dev *dev;
881
882 BT_DBG("chan %p resume", chan);
883
884 dev = lookup_dev(chan->conn);
885 if (!dev || !dev->netdev)
886 return;
887
888 netif_wake_queue(dev->netdev);
889 }
890
891 static long chan_get_sndtimeo_cb(struct l2cap_chan *chan)
892 {
893 return L2CAP_CONN_TIMEOUT;
894 }
895
896 static const struct l2cap_ops bt_6lowpan_chan_ops = {
897 .name = "L2CAP 6LoWPAN channel",
898 .new_connection = chan_new_conn_cb,
899 .recv = chan_recv_cb,
900 .close = chan_close_cb,
901 .state_change = chan_state_change_cb,
902 .ready = chan_ready_cb,
903 .resume = chan_resume_cb,
904 .suspend = chan_suspend_cb,
905 .get_sndtimeo = chan_get_sndtimeo_cb,
906 .alloc_skb = chan_alloc_skb_cb,
907
908 .teardown = l2cap_chan_no_teardown,
909 .defer = l2cap_chan_no_defer,
910 .set_shutdown = l2cap_chan_no_set_shutdown,
911 };
912
913 static inline __u8 bdaddr_type(__u8 type)
914 {
915 if (type == ADDR_LE_DEV_PUBLIC)
916 return BDADDR_LE_PUBLIC;
917 else
918 return BDADDR_LE_RANDOM;
919 }
920
921 static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type)
922 {
923 struct l2cap_chan *chan;
924 int err;
925
926 chan = chan_create();
927 if (!chan)
928 return -EINVAL;
929
930 chan->ops = &bt_6lowpan_chan_ops;
931
932 err = l2cap_chan_connect(chan, cpu_to_le16(L2CAP_PSM_IPSP), 0,
933 addr, dst_type);
934
935 BT_DBG("chan %p err %d", chan, err);
936 if (err < 0)
937 l2cap_chan_put(chan);
938
939 return err;
940 }
941
942 static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type)
943 {
944 struct lowpan_peer *peer;
945
946 BT_DBG("conn %p dst type %d", conn, dst_type);
947
948 peer = lookup_peer(conn);
949 if (!peer)
950 return -ENOENT;
951
952 BT_DBG("peer %p chan %p", peer, peer->chan);
953
954 l2cap_chan_close(peer->chan, ENOENT);
955
956 return 0;
957 }
958
959 static struct l2cap_chan *bt_6lowpan_listen(void)
960 {
961 bdaddr_t *addr = BDADDR_ANY;
962 struct l2cap_chan *chan;
963 int err;
964
965 if (!enable_6lowpan)
966 return NULL;
967
968 chan = chan_create();
969 if (!chan)
970 return NULL;
971
972 chan->ops = &bt_6lowpan_chan_ops;
973 chan->state = BT_LISTEN;
974 chan->src_type = BDADDR_LE_PUBLIC;
975
976 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
977
978 BT_DBG("chan %p src type %d", chan, chan->src_type);
979
980 err = l2cap_add_psm(chan, addr, cpu_to_le16(L2CAP_PSM_IPSP));
981 if (err) {
982 l2cap_chan_put(chan);
983 BT_ERR("psm cannot be added err %d", err);
984 return NULL;
985 }
986
987 return chan;
988 }
989
990 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type,
991 struct l2cap_conn **conn)
992 {
993 struct hci_conn *hcon;
994 struct hci_dev *hdev;
995 int n;
996
997 n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu",
998 &addr->b[5], &addr->b[4], &addr->b[3],
999 &addr->b[2], &addr->b[1], &addr->b[0],
1000 addr_type);
1001
1002 if (n < 7)
1003 return -EINVAL;
1004
1005 /* The LE_PUBLIC address type is ignored because of BDADDR_ANY */
1006 hdev = hci_get_route(addr, BDADDR_ANY, BDADDR_LE_PUBLIC);
1007 if (!hdev)
1008 return -ENOENT;
1009
1010 hci_dev_lock(hdev);
1011 hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type);
1012 hci_dev_unlock(hdev);
1013
1014 if (!hcon)
1015 return -ENOENT;
1016
1017 *conn = (struct l2cap_conn *)hcon->l2cap_data;
1018
1019 BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type);
1020
1021 return 0;
1022 }
1023
1024 static void disconnect_all_peers(void)
1025 {
1026 struct lowpan_btle_dev *entry;
1027 struct lowpan_peer *peer, *tmp_peer, *new_peer;
1028 struct list_head peers;
1029
1030 INIT_LIST_HEAD(&peers);
1031
1032 /* We make a separate list of peers as the close_cb() will
1033 * modify the device peers list so it is better not to mess
1034 * with the same list at the same time.
1035 */
1036
1037 rcu_read_lock();
1038
1039 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1040 list_for_each_entry_rcu(peer, &entry->peers, list) {
1041 new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC);
1042 if (!new_peer)
1043 break;
1044
1045 new_peer->chan = peer->chan;
1046 INIT_LIST_HEAD(&new_peer->list);
1047
1048 list_add(&new_peer->list, &peers);
1049 }
1050 }
1051
1052 rcu_read_unlock();
1053
1054 spin_lock(&devices_lock);
1055 list_for_each_entry_safe(peer, tmp_peer, &peers, list) {
1056 l2cap_chan_close(peer->chan, ENOENT);
1057
1058 list_del_rcu(&peer->list);
1059 kfree_rcu(peer, rcu);
1060 }
1061 spin_unlock(&devices_lock);
1062 }
1063
1064 struct set_enable {
1065 struct work_struct work;
1066 bool flag;
1067 };
1068
1069 static void do_enable_set(struct work_struct *work)
1070 {
1071 struct set_enable *set_enable = container_of(work,
1072 struct set_enable, work);
1073
1074 if (!set_enable->flag || enable_6lowpan != set_enable->flag)
1075 /* Disconnect existing connections if 6lowpan is
1076 * disabled
1077 */
1078 disconnect_all_peers();
1079
1080 enable_6lowpan = set_enable->flag;
1081
1082 mutex_lock(&set_lock);
1083 if (listen_chan) {
1084 l2cap_chan_close(listen_chan, 0);
1085 l2cap_chan_put(listen_chan);
1086 }
1087
1088 listen_chan = bt_6lowpan_listen();
1089 mutex_unlock(&set_lock);
1090
1091 kfree(set_enable);
1092 }
1093
1094 static int lowpan_enable_set(void *data, u64 val)
1095 {
1096 struct set_enable *set_enable;
1097
1098 set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL);
1099 if (!set_enable)
1100 return -ENOMEM;
1101
1102 set_enable->flag = !!val;
1103 INIT_WORK(&set_enable->work, do_enable_set);
1104
1105 schedule_work(&set_enable->work);
1106
1107 return 0;
1108 }
1109
1110 static int lowpan_enable_get(void *data, u64 *val)
1111 {
1112 *val = enable_6lowpan;
1113 return 0;
1114 }
1115
1116 DEFINE_DEBUGFS_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get,
1117 lowpan_enable_set, "%llu\n");
1118
1119 static ssize_t lowpan_control_write(struct file *fp,
1120 const char __user *user_buffer,
1121 size_t count,
1122 loff_t *position)
1123 {
1124 char buf[32];
1125 size_t buf_size = min(count, sizeof(buf) - 1);
1126 int ret;
1127 bdaddr_t addr;
1128 u8 addr_type;
1129 struct l2cap_conn *conn = NULL;
1130
1131 if (copy_from_user(buf, user_buffer, buf_size))
1132 return -EFAULT;
1133
1134 buf[buf_size] = '\0';
1135
1136 if (memcmp(buf, "connect ", 8) == 0) {
1137 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn);
1138 if (ret == -EINVAL)
1139 return ret;
1140
1141 mutex_lock(&set_lock);
1142 if (listen_chan) {
1143 l2cap_chan_close(listen_chan, 0);
1144 l2cap_chan_put(listen_chan);
1145 listen_chan = NULL;
1146 }
1147 mutex_unlock(&set_lock);
1148
1149 if (conn) {
1150 struct lowpan_peer *peer;
1151
1152 if (!is_bt_6lowpan(conn->hcon))
1153 return -EINVAL;
1154
1155 peer = lookup_peer(conn);
1156 if (peer) {
1157 BT_DBG("6LoWPAN connection already exists");
1158 return -EALREADY;
1159 }
1160
1161 BT_DBG("conn %p dst %pMR type %d user %d", conn,
1162 &conn->hcon->dst, conn->hcon->dst_type,
1163 addr_type);
1164 }
1165
1166 ret = bt_6lowpan_connect(&addr, addr_type);
1167 if (ret < 0)
1168 return ret;
1169
1170 return count;
1171 }
1172
1173 if (memcmp(buf, "disconnect ", 11) == 0) {
1174 ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn);
1175 if (ret < 0)
1176 return ret;
1177
1178 ret = bt_6lowpan_disconnect(conn, addr_type);
1179 if (ret < 0)
1180 return ret;
1181
1182 return count;
1183 }
1184
1185 return count;
1186 }
1187
1188 static int lowpan_control_show(struct seq_file *f, void *ptr)
1189 {
1190 struct lowpan_btle_dev *entry;
1191 struct lowpan_peer *peer;
1192
1193 spin_lock(&devices_lock);
1194
1195 list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1196 list_for_each_entry(peer, &entry->peers, list)
1197 seq_printf(f, "%pMR (type %u)\n",
1198 &peer->chan->dst, peer->chan->dst_type);
1199 }
1200
1201 spin_unlock(&devices_lock);
1202
1203 return 0;
1204 }
1205
1206 static int lowpan_control_open(struct inode *inode, struct file *file)
1207 {
1208 return single_open(file, lowpan_control_show, inode->i_private);
1209 }
1210
1211 static const struct file_operations lowpan_control_fops = {
1212 .open = lowpan_control_open,
1213 .read = seq_read,
1214 .write = lowpan_control_write,
1215 .llseek = seq_lseek,
1216 .release = single_release,
1217 };
1218
1219 static void disconnect_devices(void)
1220 {
1221 struct lowpan_btle_dev *entry, *tmp, *new_dev;
1222 struct list_head devices;
1223
1224 INIT_LIST_HEAD(&devices);
1225
1226 /* We make a separate list of devices because the unregister_netdev()
1227 * will call device_event() which will also want to modify the same
1228 * devices list.
1229 */
1230
1231 rcu_read_lock();
1232
1233 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1234 new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC);
1235 if (!new_dev)
1236 break;
1237
1238 new_dev->netdev = entry->netdev;
1239 INIT_LIST_HEAD(&new_dev->list);
1240
1241 list_add_rcu(&new_dev->list, &devices);
1242 }
1243
1244 rcu_read_unlock();
1245
1246 list_for_each_entry_safe(entry, tmp, &devices, list) {
1247 ifdown(entry->netdev);
1248 BT_DBG("Unregistering netdev %s %p",
1249 entry->netdev->name, entry->netdev);
1250 lowpan_unregister_netdev(entry->netdev);
1251 kfree(entry);
1252 }
1253 }
1254
1255 static int device_event(struct notifier_block *unused,
1256 unsigned long event, void *ptr)
1257 {
1258 struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
1259 struct lowpan_btle_dev *entry;
1260
1261 if (netdev->type != ARPHRD_6LOWPAN)
1262 return NOTIFY_DONE;
1263
1264 switch (event) {
1265 case NETDEV_UNREGISTER:
1266 spin_lock(&devices_lock);
1267 list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1268 if (entry->netdev == netdev) {
1269 BT_DBG("Unregistered netdev %s %p",
1270 netdev->name, netdev);
1271 list_del(&entry->list);
1272 break;
1273 }
1274 }
1275 spin_unlock(&devices_lock);
1276 break;
1277 }
1278
1279 return NOTIFY_DONE;
1280 }
1281
1282 static struct notifier_block bt_6lowpan_dev_notifier = {
1283 .notifier_call = device_event,
1284 };
1285
1286 static int __init bt_6lowpan_init(void)
1287 {
1288 lowpan_enable_debugfs = debugfs_create_file_unsafe("6lowpan_enable",
1289 0644, bt_debugfs,
1290 NULL,
1291 &lowpan_enable_fops);
1292 lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644,
1293 bt_debugfs, NULL,
1294 &lowpan_control_fops);
1295
1296 return register_netdevice_notifier(&bt_6lowpan_dev_notifier);
1297 }
1298
1299 static void __exit bt_6lowpan_exit(void)
1300 {
1301 debugfs_remove(lowpan_enable_debugfs);
1302 debugfs_remove(lowpan_control_debugfs);
1303
1304 if (listen_chan) {
1305 l2cap_chan_close(listen_chan, 0);
1306 l2cap_chan_put(listen_chan);
1307 }
1308
1309 disconnect_devices();
1310
1311 unregister_netdevice_notifier(&bt_6lowpan_dev_notifier);
1312 }
1313
1314 module_init(bt_6lowpan_init);
1315 module_exit(bt_6lowpan_exit);
1316
1317 MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>");
1318 MODULE_DESCRIPTION("Bluetooth 6LoWPAN");
1319 MODULE_VERSION(VERSION);
1320 MODULE_LICENSE("GPL");
Linux with added FPC-III support