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Linux 5.7.7
[linux/fpc-iii.git] / net / bluetooth / 6lowpan.c
blob4febc82a7c7613244125696cfd464099e10991dc
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
54 struct lowpan_peer {
55 struct list_head list;
56 struct rcu_head rcu;
57 struct l2cap_chan *chan;
58
59 /* peer addresses in various formats */
60 unsigned char lladdr[ETH_ALEN];
61 struct in6_addr peer_addr;
62 };
63
64 struct lowpan_btle_dev {
65 struct list_head list;
66
67 struct hci_dev *hdev;
68 struct net_device *netdev;
69 struct list_head peers;
70 atomic_t peer_count; /* number of items in peers list */
71
72 struct work_struct delete_netdev;
73 struct delayed_work notify_peers;
74 };
75
76 static inline struct lowpan_btle_dev *
77 lowpan_btle_dev(const struct net_device *netdev)
78 {
79 return (struct lowpan_btle_dev *)lowpan_dev(netdev)->priv;
80 }
81
82 static inline void peer_add(struct lowpan_btle_dev *dev,
83 struct lowpan_peer *peer)
84 {
85 list_add_rcu(&peer->list, &dev->peers);
86 atomic_inc(&dev->peer_count);
87 }
88
89 static inline bool peer_del(struct lowpan_btle_dev *dev,
90 struct lowpan_peer *peer)
91 {
92 list_del_rcu(&peer->list);
93 kfree_rcu(peer, rcu);
94
95 module_put(THIS_MODULE);
96
97 if (atomic_dec_and_test(&dev->peer_count)) {
98 BT_DBG("last peer");
99 return true;
100 }
101
102 return false;
103 }
104
105 static inline struct lowpan_peer *peer_lookup_ba(struct lowpan_btle_dev *dev,
106 bdaddr_t *ba, __u8 type)
107 {
108 struct lowpan_peer *peer;
109
110 BT_DBG("peers %d addr %pMR type %d", atomic_read(&dev->peer_count),
111 ba, type);
112
113 rcu_read_lock();
114
115 list_for_each_entry_rcu(peer, &dev->peers, list) {
116 BT_DBG("dst addr %pMR dst type %d",
117 &peer->chan->dst, peer->chan->dst_type);
118
119 if (bacmp(&peer->chan->dst, ba))
120 continue;
121
122 if (type == peer->chan->dst_type) {
123 rcu_read_unlock();
124 return peer;
125 }
126 }
127
128 rcu_read_unlock();
129
130 return NULL;
131 }
132
133 static inline struct lowpan_peer *
134 __peer_lookup_chan(struct lowpan_btle_dev *dev, struct l2cap_chan *chan)
135 {
136 struct lowpan_peer *peer;
137
138 list_for_each_entry_rcu(peer, &dev->peers, list) {
139 if (peer->chan == chan)
140 return peer;
141 }
142
143 return NULL;
144 }
145
146 static inline struct lowpan_peer *
147 __peer_lookup_conn(struct lowpan_btle_dev *dev, struct l2cap_conn *conn)
148 {
149 struct lowpan_peer *peer;
150
151 list_for_each_entry_rcu(peer, &dev->peers, list) {
152 if (peer->chan->conn == conn)
153 return peer;
154 }
155
156 return NULL;
157 }
158
159 static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_btle_dev *dev,
160 struct in6_addr *daddr,
161 struct sk_buff *skb)
162 {
163 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
164 int count = atomic_read(&dev->peer_count);
165 const struct in6_addr *nexthop;
166 struct lowpan_peer *peer;
167 struct neighbour *neigh;
168
169 BT_DBG("peers %d addr %pI6c rt %p", count, daddr, rt);
170
171 if (!rt) {
172 if (ipv6_addr_any(&lowpan_cb(skb)->gw)) {
173 /* There is neither route nor gateway,
174 * probably the destination is a direct peer.
175 */
176 nexthop = daddr;
177 } else {
178 /* There is a known gateway
179 */
180 nexthop = &lowpan_cb(skb)->gw;
181 }
182 } else {
183 nexthop = rt6_nexthop(rt, daddr);
184
185 /* We need to remember the address because it is needed
186 * by bt_xmit() when sending the packet. In bt_xmit(), the
187 * destination routing info is not set.
188 */
189 memcpy(&lowpan_cb(skb)->gw, nexthop, sizeof(struct in6_addr));
190 }
191
192 BT_DBG("gw %pI6c", nexthop);
193
194 rcu_read_lock();
195
196 list_for_each_entry_rcu(peer, &dev->peers, list) {
197 BT_DBG("dst addr %pMR dst type %d ip %pI6c",
198 &peer->chan->dst, peer->chan->dst_type,
199 &peer->peer_addr);
200
201 if (!ipv6_addr_cmp(&peer->peer_addr, nexthop)) {
202 rcu_read_unlock();
203 return peer;
204 }
205 }
206
207 /* use the neighbour cache for matching addresses assigned by SLAAC
208 */
209 neigh = __ipv6_neigh_lookup(dev->netdev, nexthop);
210 if (neigh) {
211 list_for_each_entry_rcu(peer, &dev->peers, list) {
212 if (!memcmp(neigh->ha, peer->lladdr, ETH_ALEN)) {
213 neigh_release(neigh);
214 rcu_read_unlock();
215 return peer;
216 }
217 }
218 neigh_release(neigh);
219 }
220
221 rcu_read_unlock();
222
223 return NULL;
224 }
225
226 static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn)
227 {
228 struct lowpan_btle_dev *entry;
229 struct lowpan_peer *peer = NULL;
230
231 rcu_read_lock();
232
233 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
234 peer = __peer_lookup_conn(entry, conn);
235 if (peer)
236 break;
237 }
238
239 rcu_read_unlock();
240
241 return peer;
242 }
243
244 static struct lowpan_btle_dev *lookup_dev(struct l2cap_conn *conn)
245 {
246 struct lowpan_btle_dev *entry;
247 struct lowpan_btle_dev *dev = NULL;
248
249 rcu_read_lock();
250
251 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
252 if (conn->hcon->hdev == entry->hdev) {
253 dev = entry;
254 break;
255 }
256 }
257
258 rcu_read_unlock();
259
260 return dev;
261 }
262
263 static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev)
264 {
265 struct sk_buff *skb_cp;
266
267 skb_cp = skb_copy(skb, GFP_ATOMIC);
268 if (!skb_cp)
269 return NET_RX_DROP;
270
271 return netif_rx_ni(skb_cp);
272 }
273
274 static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev,
275 struct lowpan_peer *peer)
276 {
277 const u8 *saddr;
278
279 saddr = peer->lladdr;
280
281 return lowpan_header_decompress(skb, netdev, netdev->dev_addr, saddr);
282 }
283
284 static int recv_pkt(struct sk_buff *skb, struct net_device *dev,
285 struct lowpan_peer *peer)
286 {
287 struct sk_buff *local_skb;
288 int ret;
289
290 if (!netif_running(dev))
291 goto drop;
292
293 if (dev->type != ARPHRD_6LOWPAN || !skb->len)
294 goto drop;
295
296 skb_reset_network_header(skb);
297
298 skb = skb_share_check(skb, GFP_ATOMIC);
299 if (!skb)
300 goto drop;
301
302 /* check that it's our buffer */
303 if (lowpan_is_ipv6(*skb_network_header(skb))) {
304 /* Pull off the 1-byte of 6lowpan header. */
305 skb_pull(skb, 1);
306
307 /* Copy the packet so that the IPv6 header is
308 * properly aligned.
309 */
310 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
311 skb_tailroom(skb), GFP_ATOMIC);
312 if (!local_skb)
313 goto drop;
314
315 local_skb->protocol = htons(ETH_P_IPV6);
316 local_skb->pkt_type = PACKET_HOST;
317 local_skb->dev = dev;
318
319 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
320
321 if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) {
322 kfree_skb(local_skb);
323 goto drop;
324 }
325
326 dev->stats.rx_bytes += skb->len;
327 dev->stats.rx_packets++;
328
329 consume_skb(local_skb);
330 consume_skb(skb);
331 } else if (lowpan_is_iphc(*skb_network_header(skb))) {
332 local_skb = skb_clone(skb, GFP_ATOMIC);
333 if (!local_skb)
334 goto drop;
335
336 local_skb->dev = dev;
337
338 ret = iphc_decompress(local_skb, dev, peer);
339 if (ret < 0) {
340 BT_DBG("iphc_decompress failed: %d", ret);
341 kfree_skb(local_skb);
342 goto drop;
343 }
344
345 local_skb->protocol = htons(ETH_P_IPV6);
346 local_skb->pkt_type = PACKET_HOST;
347
348 if (give_skb_to_upper(local_skb, dev)
349 != NET_RX_SUCCESS) {
350 kfree_skb(local_skb);
351 goto drop;
352 }
353
354 dev->stats.rx_bytes += skb->len;
355 dev->stats.rx_packets++;
356
357 consume_skb(local_skb);
358 consume_skb(skb);
359 } else {
360 BT_DBG("unknown packet type");
361 goto drop;
362 }
363
364 return NET_RX_SUCCESS;
365
366 drop:
367 dev->stats.rx_dropped++;
368 return NET_RX_DROP;
369 }
370
371 /* Packet from BT LE device */
372 static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
373 {
374 struct lowpan_btle_dev *dev;
375 struct lowpan_peer *peer;
376 int err;
377
378 peer = lookup_peer(chan->conn);
379 if (!peer)
380 return -ENOENT;
381
382 dev = lookup_dev(chan->conn);
383 if (!dev || !dev->netdev)
384 return -ENOENT;
385
386 err = recv_pkt(skb, dev->netdev, peer);
387 if (err) {
388 BT_DBG("recv pkt %d", err);
389 err = -EAGAIN;
390 }
391
392 return err;
393 }
394
395 static int setup_header(struct sk_buff *skb, struct net_device *netdev,
396 bdaddr_t *peer_addr, u8 *peer_addr_type)
397 {
398 struct in6_addr ipv6_daddr;
399 struct ipv6hdr *hdr;
400 struct lowpan_btle_dev *dev;
401 struct lowpan_peer *peer;
402 u8 *daddr;
403 int err, status = 0;
404
405 hdr = ipv6_hdr(skb);
406
407 dev = lowpan_btle_dev(netdev);
408
409 memcpy(&ipv6_daddr, &hdr->daddr, sizeof(ipv6_daddr));
410
411 if (ipv6_addr_is_multicast(&ipv6_daddr)) {
412 lowpan_cb(skb)->chan = NULL;
413 daddr = NULL;
414 } else {
415 BT_DBG("dest IP %pI6c", &ipv6_daddr);
416
417 /* The packet might be sent to 6lowpan interface
418 * because of routing (either via default route
419 * or user set route) so get peer according to
420 * the destination address.
421 */
422 peer = peer_lookup_dst(dev, &ipv6_daddr, skb);
423 if (!peer) {
424 BT_DBG("no such peer");
425 return -ENOENT;
426 }
427
428 daddr = peer->lladdr;
429 *peer_addr = peer->chan->dst;
430 *peer_addr_type = peer->chan->dst_type;
431 lowpan_cb(skb)->chan = peer->chan;
432
433 status = 1;
434 }
435
436 lowpan_header_compress(skb, netdev, daddr, dev->netdev->dev_addr);
437
438 err = dev_hard_header(skb, netdev, ETH_P_IPV6, NULL, NULL, 0);
439 if (err < 0)
440 return err;
441
442 return status;
443 }
444
445 static int header_create(struct sk_buff *skb, struct net_device *netdev,
446 unsigned short type, const void *_daddr,
447 const void *_saddr, unsigned int len)
448 {
449 if (type != ETH_P_IPV6)
450 return -EINVAL;
451
452 return 0;
453 }
454
455 /* Packet to BT LE device */
456 static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb,
457 struct net_device *netdev)
458 {
459 struct msghdr msg;
460 struct kvec iv;
461 int err;
462
463 /* Remember the skb so that we can send EAGAIN to the caller if
464 * we run out of credits.
465 */
466 chan->data = skb;
467
468 iv.iov_base = skb->data;
469 iv.iov_len = skb->len;
470
471 memset(&msg, 0, sizeof(msg));
472 iov_iter_kvec(&msg.msg_iter, WRITE, &iv, 1, skb->len);
473
474 err = l2cap_chan_send(chan, &msg, skb->len);
475 if (err > 0) {
476 netdev->stats.tx_bytes += err;
477 netdev->stats.tx_packets++;
478 return 0;
479 }
480
481 if (err < 0)
482 netdev->stats.tx_errors++;
483
484 return err;
485 }
486
487 static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev)
488 {
489 struct sk_buff *local_skb;
490 struct lowpan_btle_dev *entry;
491 int err = 0;
492
493 rcu_read_lock();
494
495 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
496 struct lowpan_peer *pentry;
497 struct lowpan_btle_dev *dev;
498
499 if (entry->netdev != netdev)
500 continue;
501
502 dev = lowpan_btle_dev(entry->netdev);
503
504 list_for_each_entry_rcu(pentry, &dev->peers, list) {
505 int ret;
506
507 local_skb = skb_clone(skb, GFP_ATOMIC);
508
509 BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
510 netdev->name,
511 &pentry->chan->dst, pentry->chan->dst_type,
512 &pentry->peer_addr, pentry->chan);
513 ret = send_pkt(pentry->chan, local_skb, netdev);
514 if (ret < 0)
515 err = ret;
516
517 kfree_skb(local_skb);
518 }
519 }
520
521 rcu_read_unlock();
522
523 return err;
524 }
525
526 static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev)
527 {
528 int err = 0;
529 bdaddr_t addr;
530 u8 addr_type;
531
532 /* We must take a copy of the skb before we modify/replace the ipv6
533 * header as the header could be used elsewhere
534 */
535 skb = skb_unshare(skb, GFP_ATOMIC);
536 if (!skb)
537 return NET_XMIT_DROP;
538
539 /* Return values from setup_header()
540 * <0 - error, packet is dropped
541 * 0 - this is a multicast packet
542 * 1 - this is unicast packet
543 */
544 err = setup_header(skb, netdev, &addr, &addr_type);
545 if (err < 0) {
546 kfree_skb(skb);
547 return NET_XMIT_DROP;
548 }
549
550 if (err) {
551 if (lowpan_cb(skb)->chan) {
552 BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
553 netdev->name, &addr, addr_type,
554 &lowpan_cb(skb)->addr, lowpan_cb(skb)->chan);
555 err = send_pkt(lowpan_cb(skb)->chan, skb, netdev);
556 } else {
557 err = -ENOENT;
558 }
559 } else {
560 /* We need to send the packet to every device behind this
561 * interface.
562 */
563 err = send_mcast_pkt(skb, netdev);
564 }
565
566 dev_kfree_skb(skb);
567
568 if (err)
569 BT_DBG("ERROR: xmit failed (%d)", err);
570
571 return err < 0 ? NET_XMIT_DROP : err;
572 }
573
574 static const struct net_device_ops netdev_ops = {
575 .ndo_start_xmit = bt_xmit,
576 };
577
578 static const struct header_ops header_ops = {
579 .create = header_create,
580 };
581
582 static void netdev_setup(struct net_device *dev)
583 {
584 dev->hard_header_len = 0;
585 dev->needed_tailroom = 0;
586 dev->flags = IFF_RUNNING | IFF_MULTICAST;
587 dev->watchdog_timeo = 0;
588 dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
589
590 dev->netdev_ops = &netdev_ops;
591 dev->header_ops = &header_ops;
592 dev->needs_free_netdev = true;
593 }
594
595 static struct device_type bt_type = {
596 .name = "bluetooth",
597 };
598
599 static void ifup(struct net_device *netdev)
600 {
601 int err;
602
603 rtnl_lock();
604 err = dev_open(netdev, NULL);
605 if (err < 0)
606 BT_INFO("iface %s cannot be opened (%d)", netdev->name, err);
607 rtnl_unlock();
608 }
609
610 static void ifdown(struct net_device *netdev)
611 {
612 rtnl_lock();
613 dev_close(netdev);
614 rtnl_unlock();
615 }
616
617 static void do_notify_peers(struct work_struct *work)
618 {
619 struct lowpan_btle_dev *dev = container_of(work, struct lowpan_btle_dev,
620 notify_peers.work);
621
622 netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */
623 }
624
625 static bool is_bt_6lowpan(struct hci_conn *hcon)
626 {
627 if (hcon->type != LE_LINK)
628 return false;
629
630 if (!enable_6lowpan)
631 return false;
632
633 return true;
634 }
635
636 static struct l2cap_chan *chan_create(void)
637 {
638 struct l2cap_chan *chan;
639
640 chan = l2cap_chan_create();
641 if (!chan)
642 return NULL;
643
644 l2cap_chan_set_defaults(chan);
645
646 chan->chan_type = L2CAP_CHAN_CONN_ORIENTED;
647 chan->mode = L2CAP_MODE_LE_FLOWCTL;
648 chan->imtu = 1280;
649
650 return chan;
651 }
652
653 static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan,
654 struct lowpan_btle_dev *dev,
655 bool new_netdev)
656 {
657 struct lowpan_peer *peer;
658
659 peer = kzalloc(sizeof(*peer), GFP_ATOMIC);
660 if (!peer)
661 return NULL;
662
663 peer->chan = chan;
664 memset(&peer->peer_addr, 0, sizeof(struct in6_addr));
665
666 baswap((void *)peer->lladdr, &chan->dst);
667
668 lowpan_iphc_uncompress_eui48_lladdr(&peer->peer_addr, peer->lladdr);
669
670 spin_lock(&devices_lock);
671 INIT_LIST_HEAD(&peer->list);
672 peer_add(dev, peer);
673 spin_unlock(&devices_lock);
674
675 /* Notifying peers about us needs to be done without locks held */
676 if (new_netdev)
677 INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers);
678 schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100));
679
680 return peer->chan;
681 }
682
683 static int setup_netdev(struct l2cap_chan *chan, struct lowpan_btle_dev **dev)
684 {
685 struct net_device *netdev;
686 int err = 0;
687
688 netdev = alloc_netdev(LOWPAN_PRIV_SIZE(sizeof(struct lowpan_btle_dev)),
689 IFACE_NAME_TEMPLATE, NET_NAME_UNKNOWN,
690 netdev_setup);
691 if (!netdev)
692 return -ENOMEM;
693
694 netdev->addr_assign_type = NET_ADDR_PERM;
695 baswap((void *)netdev->dev_addr, &chan->src);
696
697 netdev->netdev_ops = &netdev_ops;
698 SET_NETDEV_DEV(netdev, &chan->conn->hcon->hdev->dev);
699 SET_NETDEV_DEVTYPE(netdev, &bt_type);
700
701 *dev = lowpan_btle_dev(netdev);
702 (*dev)->netdev = netdev;
703 (*dev)->hdev = chan->conn->hcon->hdev;
704 INIT_LIST_HEAD(&(*dev)->peers);
705
706 spin_lock(&devices_lock);
707 INIT_LIST_HEAD(&(*dev)->list);
708 list_add_rcu(&(*dev)->list, &bt_6lowpan_devices);
709 spin_unlock(&devices_lock);
710
711 err = lowpan_register_netdev(netdev, LOWPAN_LLTYPE_BTLE);
712 if (err < 0) {
713 BT_INFO("register_netdev failed %d", err);
714 spin_lock(&devices_lock);
715 list_del_rcu(&(*dev)->list);
716 spin_unlock(&devices_lock);
717 free_netdev(netdev);
718 goto out;
719 }
720
721 BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d",
722 netdev->ifindex, &chan->dst, chan->dst_type,
723 &chan->src, chan->src_type);
724 set_bit(__LINK_STATE_PRESENT, &netdev->state);
725
726 return 0;
727
728 out:
729 return err;
730 }
731
732 static inline void chan_ready_cb(struct l2cap_chan *chan)
733 {
734 struct lowpan_btle_dev *dev;
735 bool new_netdev = false;
736
737 dev = lookup_dev(chan->conn);
738
739 BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev);
740
741 if (!dev) {
742 if (setup_netdev(chan, &dev) < 0) {
743 l2cap_chan_del(chan, -ENOENT);
744 return;
745 }
746 new_netdev = true;
747 }
748
749 if (!try_module_get(THIS_MODULE))
750 return;
751
752 add_peer_chan(chan, dev, new_netdev);
753 ifup(dev->netdev);
754 }
755
756 static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan)
757 {
758 struct l2cap_chan *chan;
759
760 chan = chan_create();
761 if (!chan)
762 return NULL;
763
764 chan->ops = pchan->ops;
765
766 BT_DBG("chan %p pchan %p", chan, pchan);
767
768 return chan;
769 }
770
771 static void delete_netdev(struct work_struct *work)
772 {
773 struct lowpan_btle_dev *entry = container_of(work,
774 struct lowpan_btle_dev,
775 delete_netdev);
776
777 lowpan_unregister_netdev(entry->netdev);
778
779 /* The entry pointer is deleted by the netdev destructor. */
780 }
781
782 static void chan_close_cb(struct l2cap_chan *chan)
783 {
784 struct lowpan_btle_dev *entry;
785 struct lowpan_btle_dev *dev = NULL;
786 struct lowpan_peer *peer;
787 int err = -ENOENT;
788 bool last = false, remove = true;
789
790 BT_DBG("chan %p conn %p", chan, chan->conn);
791
792 if (chan->conn && chan->conn->hcon) {
793 if (!is_bt_6lowpan(chan->conn->hcon))
794 return;
795
796 /* If conn is set, then the netdev is also there and we should
797 * not remove it.
798 */
799 remove = false;
800 }
801
802 spin_lock(&devices_lock);
803
804 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
805 dev = lowpan_btle_dev(entry->netdev);
806 peer = __peer_lookup_chan(dev, chan);
807 if (peer) {
808 last = peer_del(dev, peer);
809 err = 0;
810
811 BT_DBG("dev %p removing %speer %p", dev,
812 last ? "last " : "1 ", peer);
813 BT_DBG("chan %p orig refcnt %d", chan,
814 kref_read(&chan->kref));
815
816 l2cap_chan_put(chan);
817 break;
818 }
819 }
820
821 if (!err && last && dev && !atomic_read(&dev->peer_count)) {
822 spin_unlock(&devices_lock);
823
824 cancel_delayed_work_sync(&dev->notify_peers);
825
826 ifdown(dev->netdev);
827
828 if (remove) {
829 INIT_WORK(&entry->delete_netdev, delete_netdev);
830 schedule_work(&entry->delete_netdev);
831 }
832 } else {
833 spin_unlock(&devices_lock);
834 }
835
836 return;
837 }
838
839 static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err)
840 {
841 BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn,
842 state_to_string(state), err);
843 }
844
845 static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan,
846 unsigned long hdr_len,
847 unsigned long len, int nb)
848 {
849 /* Note that we must allocate using GFP_ATOMIC here as
850 * this function is called originally from netdev hard xmit
851 * function in atomic context.
852 */
853 return bt_skb_alloc(hdr_len + len, GFP_ATOMIC);
854 }
855
856 static void chan_suspend_cb(struct l2cap_chan *chan)
857 {
858 struct lowpan_btle_dev *dev;
859
860 BT_DBG("chan %p suspend", chan);
861
862 dev = lookup_dev(chan->conn);
863 if (!dev || !dev->netdev)
864 return;
865
866 netif_stop_queue(dev->netdev);
867 }
868
869 static void chan_resume_cb(struct l2cap_chan *chan)
870 {
871 struct lowpan_btle_dev *dev;
872
873 BT_DBG("chan %p resume", chan);
874
875 dev = lookup_dev(chan->conn);
876 if (!dev || !dev->netdev)
877 return;
878
879 netif_wake_queue(dev->netdev);
880 }
881
882 static long chan_get_sndtimeo_cb(struct l2cap_chan *chan)
883 {
884 return L2CAP_CONN_TIMEOUT;
885 }
886
887 static const struct l2cap_ops bt_6lowpan_chan_ops = {
888 .name = "L2CAP 6LoWPAN channel",
889 .new_connection = chan_new_conn_cb,
890 .recv = chan_recv_cb,
891 .close = chan_close_cb,
892 .state_change = chan_state_change_cb,
893 .ready = chan_ready_cb,
894 .resume = chan_resume_cb,
895 .suspend = chan_suspend_cb,
896 .get_sndtimeo = chan_get_sndtimeo_cb,
897 .alloc_skb = chan_alloc_skb_cb,
898
899 .teardown = l2cap_chan_no_teardown,
900 .defer = l2cap_chan_no_defer,
901 .set_shutdown = l2cap_chan_no_set_shutdown,
902 };
903
904 static inline __u8 bdaddr_type(__u8 type)
905 {
906 if (type == ADDR_LE_DEV_PUBLIC)
907 return BDADDR_LE_PUBLIC;
908 else
909 return BDADDR_LE_RANDOM;
910 }
911
912 static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type)
913 {
914 struct l2cap_chan *chan;
915 int err;
916
917 chan = chan_create();
918 if (!chan)
919 return -EINVAL;
920
921 chan->ops = &bt_6lowpan_chan_ops;
922
923 err = l2cap_chan_connect(chan, cpu_to_le16(L2CAP_PSM_IPSP), 0,
924 addr, dst_type);
925
926 BT_DBG("chan %p err %d", chan, err);
927 if (err < 0)
928 l2cap_chan_put(chan);
929
930 return err;
931 }
932
933 static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type)
934 {
935 struct lowpan_peer *peer;
936
937 BT_DBG("conn %p dst type %d", conn, dst_type);
938
939 peer = lookup_peer(conn);
940 if (!peer)
941 return -ENOENT;
942
943 BT_DBG("peer %p chan %p", peer, peer->chan);
944
945 l2cap_chan_close(peer->chan, ENOENT);
946
947 return 0;
948 }
949
950 static struct l2cap_chan *bt_6lowpan_listen(void)
951 {
952 bdaddr_t *addr = BDADDR_ANY;
953 struct l2cap_chan *chan;
954 int err;
955
956 if (!enable_6lowpan)
957 return NULL;
958
959 chan = chan_create();
960 if (!chan)
961 return NULL;
962
963 chan->ops = &bt_6lowpan_chan_ops;
964 chan->state = BT_LISTEN;
965 chan->src_type = BDADDR_LE_PUBLIC;
966
967 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
968
969 BT_DBG("chan %p src type %d", chan, chan->src_type);
970
971 err = l2cap_add_psm(chan, addr, cpu_to_le16(L2CAP_PSM_IPSP));
972 if (err) {
973 l2cap_chan_put(chan);
974 BT_ERR("psm cannot be added err %d", err);
975 return NULL;
976 }
977
978 return chan;
979 }
980
981 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type,
982 struct l2cap_conn **conn)
983 {
984 struct hci_conn *hcon;
985 struct hci_dev *hdev;
986 int n;
987
988 n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu",
989 &addr->b[5], &addr->b[4], &addr->b[3],
990 &addr->b[2], &addr->b[1], &addr->b[0],
991 addr_type);
992
993 if (n < 7)
994 return -EINVAL;
995
996 /* The LE_PUBLIC address type is ignored because of BDADDR_ANY */
997 hdev = hci_get_route(addr, BDADDR_ANY, BDADDR_LE_PUBLIC);
998 if (!hdev)
999 return -ENOENT;
1000
1001 hci_dev_lock(hdev);
1002 hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type);
1003 hci_dev_unlock(hdev);
1004
1005 if (!hcon)
1006 return -ENOENT;
1007
1008 *conn = (struct l2cap_conn *)hcon->l2cap_data;
1009
1010 BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type);
1011
1012 return 0;
1013 }
1014
1015 static void disconnect_all_peers(void)
1016 {
1017 struct lowpan_btle_dev *entry;
1018 struct lowpan_peer *peer, *tmp_peer, *new_peer;
1019 struct list_head peers;
1020
1021 INIT_LIST_HEAD(&peers);
1022
1023 /* We make a separate list of peers as the close_cb() will
1024 * modify the device peers list so it is better not to mess
1025 * with the same list at the same time.
1026 */
1027
1028 rcu_read_lock();
1029
1030 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1031 list_for_each_entry_rcu(peer, &entry->peers, list) {
1032 new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC);
1033 if (!new_peer)
1034 break;
1035
1036 new_peer->chan = peer->chan;
1037 INIT_LIST_HEAD(&new_peer->list);
1038
1039 list_add(&new_peer->list, &peers);
1040 }
1041 }
1042
1043 rcu_read_unlock();
1044
1045 spin_lock(&devices_lock);
1046 list_for_each_entry_safe(peer, tmp_peer, &peers, list) {
1047 l2cap_chan_close(peer->chan, ENOENT);
1048
1049 list_del_rcu(&peer->list);
1050 kfree_rcu(peer, rcu);
1051 }
1052 spin_unlock(&devices_lock);
1053 }
1054
1055 struct set_enable {
1056 struct work_struct work;
1057 bool flag;
1058 };
1059
1060 static void do_enable_set(struct work_struct *work)
1061 {
1062 struct set_enable *set_enable = container_of(work,
1063 struct set_enable, work);
1064
1065 if (!set_enable->flag || enable_6lowpan != set_enable->flag)
1066 /* Disconnect existing connections if 6lowpan is
1067 * disabled
1068 */
1069 disconnect_all_peers();
1070
1071 enable_6lowpan = set_enable->flag;
1072
1073 if (listen_chan) {
1074 l2cap_chan_close(listen_chan, 0);
1075 l2cap_chan_put(listen_chan);
1076 }
1077
1078 listen_chan = bt_6lowpan_listen();
1079
1080 kfree(set_enable);
1081 }
1082
1083 static int lowpan_enable_set(void *data, u64 val)
1084 {
1085 struct set_enable *set_enable;
1086
1087 set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL);
1088 if (!set_enable)
1089 return -ENOMEM;
1090
1091 set_enable->flag = !!val;
1092 INIT_WORK(&set_enable->work, do_enable_set);
1093
1094 schedule_work(&set_enable->work);
1095
1096 return 0;
1097 }
1098
1099 static int lowpan_enable_get(void *data, u64 *val)
1100 {
1101 *val = enable_6lowpan;
1102 return 0;
1103 }
1104
1105 DEFINE_DEBUGFS_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get,
1106 lowpan_enable_set, "%llu\n");
1107
1108 static ssize_t lowpan_control_write(struct file *fp,
1109 const char __user *user_buffer,
1110 size_t count,
1111 loff_t *position)
1112 {
1113 char buf[32];
1114 size_t buf_size = min(count, sizeof(buf) - 1);
1115 int ret;
1116 bdaddr_t addr;
1117 u8 addr_type;
1118 struct l2cap_conn *conn = NULL;
1119
1120 if (copy_from_user(buf, user_buffer, buf_size))
1121 return -EFAULT;
1122
1123 buf[buf_size] = '\0';
1124
1125 if (memcmp(buf, "connect ", 8) == 0) {
1126 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn);
1127 if (ret == -EINVAL)
1128 return ret;
1129
1130 if (listen_chan) {
1131 l2cap_chan_close(listen_chan, 0);
1132 l2cap_chan_put(listen_chan);
1133 listen_chan = NULL;
1134 }
1135
1136 if (conn) {
1137 struct lowpan_peer *peer;
1138
1139 if (!is_bt_6lowpan(conn->hcon))
1140 return -EINVAL;
1141
1142 peer = lookup_peer(conn);
1143 if (peer) {
1144 BT_DBG("6LoWPAN connection already exists");
1145 return -EALREADY;
1146 }
1147
1148 BT_DBG("conn %p dst %pMR type %d user %d", conn,
1149 &conn->hcon->dst, conn->hcon->dst_type,
1150 addr_type);
1151 }
1152
1153 ret = bt_6lowpan_connect(&addr, addr_type);
1154 if (ret < 0)
1155 return ret;
1156
1157 return count;
1158 }
1159
1160 if (memcmp(buf, "disconnect ", 11) == 0) {
1161 ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn);
1162 if (ret < 0)
1163 return ret;
1164
1165 ret = bt_6lowpan_disconnect(conn, addr_type);
1166 if (ret < 0)
1167 return ret;
1168
1169 return count;
1170 }
1171
1172 return count;
1173 }
1174
1175 static int lowpan_control_show(struct seq_file *f, void *ptr)
1176 {
1177 struct lowpan_btle_dev *entry;
1178 struct lowpan_peer *peer;
1179
1180 spin_lock(&devices_lock);
1181
1182 list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1183 list_for_each_entry(peer, &entry->peers, list)
1184 seq_printf(f, "%pMR (type %u)\n",
1185 &peer->chan->dst, peer->chan->dst_type);
1186 }
1187
1188 spin_unlock(&devices_lock);
1189
1190 return 0;
1191 }
1192
1193 static int lowpan_control_open(struct inode *inode, struct file *file)
1194 {
1195 return single_open(file, lowpan_control_show, inode->i_private);
1196 }
1197
1198 static const struct file_operations lowpan_control_fops = {
1199 .open = lowpan_control_open,
1200 .read = seq_read,
1201 .write = lowpan_control_write,
1202 .llseek = seq_lseek,
1203 .release = single_release,
1204 };
1205
1206 static void disconnect_devices(void)
1207 {
1208 struct lowpan_btle_dev *entry, *tmp, *new_dev;
1209 struct list_head devices;
1210
1211 INIT_LIST_HEAD(&devices);
1212
1213 /* We make a separate list of devices because the unregister_netdev()
1214 * will call device_event() which will also want to modify the same
1215 * devices list.
1216 */
1217
1218 rcu_read_lock();
1219
1220 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1221 new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC);
1222 if (!new_dev)
1223 break;
1224
1225 new_dev->netdev = entry->netdev;
1226 INIT_LIST_HEAD(&new_dev->list);
1227
1228 list_add_rcu(&new_dev->list, &devices);
1229 }
1230
1231 rcu_read_unlock();
1232
1233 list_for_each_entry_safe(entry, tmp, &devices, list) {
1234 ifdown(entry->netdev);
1235 BT_DBG("Unregistering netdev %s %p",
1236 entry->netdev->name, entry->netdev);
1237 lowpan_unregister_netdev(entry->netdev);
1238 kfree(entry);
1239 }
1240 }
1241
1242 static int device_event(struct notifier_block *unused,
1243 unsigned long event, void *ptr)
1244 {
1245 struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
1246 struct lowpan_btle_dev *entry;
1247
1248 if (netdev->type != ARPHRD_6LOWPAN)
1249 return NOTIFY_DONE;
1250
1251 switch (event) {
1252 case NETDEV_UNREGISTER:
1253 spin_lock(&devices_lock);
1254 list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1255 if (entry->netdev == netdev) {
1256 BT_DBG("Unregistered netdev %s %p",
1257 netdev->name, netdev);
1258 list_del(&entry->list);
1259 break;
1260 }
1261 }
1262 spin_unlock(&devices_lock);
1263 break;
1264 }
1265
1266 return NOTIFY_DONE;
1267 }
1268
1269 static struct notifier_block bt_6lowpan_dev_notifier = {
1270 .notifier_call = device_event,
1271 };
1272
1273 static int __init bt_6lowpan_init(void)
1274 {
1275 lowpan_enable_debugfs = debugfs_create_file_unsafe("6lowpan_enable",
1276 0644, bt_debugfs,
1277 NULL,
1278 &lowpan_enable_fops);
1279 lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644,
1280 bt_debugfs, NULL,
1281 &lowpan_control_fops);
1282
1283 return register_netdevice_notifier(&bt_6lowpan_dev_notifier);
1284 }
1285
1286 static void __exit bt_6lowpan_exit(void)
1287 {
1288 debugfs_remove(lowpan_enable_debugfs);
1289 debugfs_remove(lowpan_control_debugfs);
1290
1291 if (listen_chan) {
1292 l2cap_chan_close(listen_chan, 0);
1293 l2cap_chan_put(listen_chan);
1294 }
1295
1296 disconnect_devices();
1297
1298 unregister_netdevice_notifier(&bt_6lowpan_dev_notifier);
1299 }
1300
1301 module_init(bt_6lowpan_init);
1302 module_exit(bt_6lowpan_exit);
1303
1304 MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>");
1305 MODULE_DESCRIPTION("Bluetooth 6LoWPAN");
1306 MODULE_VERSION(VERSION);
1307 MODULE_LICENSE("GPL");
Linux with added FPC-III support