GNU Linux-libre 4.19.211-gnu1
[releases.git] / net / bluetooth / 6lowpan.c
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 #include <net/pkt_sched.h>
24
25 #include <net/bluetooth/bluetooth.h>
26 #include <net/bluetooth/hci_core.h>
27 #include <net/bluetooth/l2cap.h>
28
29 #include <net/6lowpan.h> /* for the compression support */
30
31 #define VERSION "0.1"
32
33 static struct dentry *lowpan_enable_debugfs;
34 static struct dentry *lowpan_control_debugfs;
35
36 #define IFACE_NAME_TEMPLATE "bt%d"
37
38 struct skb_cb {
39         struct in6_addr addr;
40         struct in6_addr gw;
41         struct l2cap_chan *chan;
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  */
52 static LIST_HEAD(bt_6lowpan_devices);
53 static DEFINE_SPINLOCK(devices_lock);
54
55 static bool enable_6lowpan;
56
57 /* We are listening incoming connections via this channel
58  */
59 static struct l2cap_chan *listen_chan;
60 static DEFINE_MUTEX(set_lock);
61
62 struct lowpan_peer {
63         struct list_head list;
64         struct rcu_head rcu;
65         struct l2cap_chan *chan;
66
67         /* peer addresses in various formats */
68         unsigned char lladdr[ETH_ALEN];
69         struct in6_addr peer_addr;
70 };
71
72 struct lowpan_btle_dev {
73         struct list_head list;
74
75         struct hci_dev *hdev;
76         struct net_device *netdev;
77         struct list_head peers;
78         atomic_t peer_count; /* number of items in peers list */
79
80         struct work_struct delete_netdev;
81         struct delayed_work notify_peers;
82 };
83
84 static inline struct lowpan_btle_dev *
85 lowpan_btle_dev(const struct net_device *netdev)
86 {
87         return (struct lowpan_btle_dev *)lowpan_dev(netdev)->priv;
88 }
89
90 static inline void peer_add(struct lowpan_btle_dev *dev,
91                             struct lowpan_peer *peer)
92 {
93         list_add_rcu(&peer->list, &dev->peers);
94         atomic_inc(&dev->peer_count);
95 }
96
97 static inline bool peer_del(struct lowpan_btle_dev *dev,
98                             struct lowpan_peer *peer)
99 {
100         list_del_rcu(&peer->list);
101         kfree_rcu(peer, rcu);
102
103         module_put(THIS_MODULE);
104
105         if (atomic_dec_and_test(&dev->peer_count)) {
106                 BT_DBG("last peer");
107                 return true;
108         }
109
110         return false;
111 }
112
113 static inline struct lowpan_peer *peer_lookup_ba(struct lowpan_btle_dev *dev,
114                                                  bdaddr_t *ba, __u8 type)
115 {
116         struct lowpan_peer *peer;
117
118         BT_DBG("peers %d addr %pMR type %d", atomic_read(&dev->peer_count),
119                ba, type);
120
121         rcu_read_lock();
122
123         list_for_each_entry_rcu(peer, &dev->peers, list) {
124                 BT_DBG("dst addr %pMR dst type %d",
125                        &peer->chan->dst, peer->chan->dst_type);
126
127                 if (bacmp(&peer->chan->dst, ba))
128                         continue;
129
130                 if (type == peer->chan->dst_type) {
131                         rcu_read_unlock();
132                         return peer;
133                 }
134         }
135
136         rcu_read_unlock();
137
138         return NULL;
139 }
140
141 static inline struct lowpan_peer *
142 __peer_lookup_chan(struct lowpan_btle_dev *dev, struct l2cap_chan *chan)
143 {
144         struct lowpan_peer *peer;
145
146         list_for_each_entry_rcu(peer, &dev->peers, list) {
147                 if (peer->chan == chan)
148                         return peer;
149         }
150
151         return NULL;
152 }
153
154 static inline struct lowpan_peer *
155 __peer_lookup_conn(struct lowpan_btle_dev *dev, struct l2cap_conn *conn)
156 {
157         struct lowpan_peer *peer;
158
159         list_for_each_entry_rcu(peer, &dev->peers, list) {
160                 if (peer->chan->conn == conn)
161                         return peer;
162         }
163
164         return NULL;
165 }
166
167 static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_btle_dev *dev,
168                                                   struct in6_addr *daddr,
169                                                   struct sk_buff *skb)
170 {
171         struct lowpan_peer *peer;
172         struct in6_addr *nexthop;
173         struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
174         int count = atomic_read(&dev->peer_count);
175
176         BT_DBG("peers %d addr %pI6c rt %p", count, daddr, rt);
177
178         /* If we have multiple 6lowpan peers, then check where we should
179          * send the packet. If only one peer exists, then we can send the
180          * packet right away.
181          */
182         if (count == 1) {
183                 rcu_read_lock();
184                 peer = list_first_or_null_rcu(&dev->peers, struct lowpan_peer,
185                                               list);
186                 rcu_read_unlock();
187                 return peer;
188         }
189
190         if (!rt) {
191                 if (ipv6_addr_any(&lowpan_cb(skb)->gw)) {
192                         /* There is neither route nor gateway,
193                          * probably the destination is a direct peer.
194                          */
195                         nexthop = daddr;
196                 } else {
197                         /* There is a known gateway
198                          */
199                         nexthop = &lowpan_cb(skb)->gw;
200                 }
201         } else {
202                 nexthop = rt6_nexthop(rt, daddr);
203
204                 /* We need to remember the address because it is needed
205                  * by bt_xmit() when sending the packet. In bt_xmit(), the
206                  * destination routing info is not set.
207                  */
208                 memcpy(&lowpan_cb(skb)->gw, nexthop, sizeof(struct in6_addr));
209         }
210
211         BT_DBG("gw %pI6c", nexthop);
212
213         rcu_read_lock();
214
215         list_for_each_entry_rcu(peer, &dev->peers, list) {
216                 BT_DBG("dst addr %pMR dst type %d ip %pI6c",
217                        &peer->chan->dst, peer->chan->dst_type,
218                        &peer->peer_addr);
219
220                 if (!ipv6_addr_cmp(&peer->peer_addr, nexthop)) {
221                         rcu_read_unlock();
222                         return peer;
223                 }
224         }
225
226         rcu_read_unlock();
227
228         return NULL;
229 }
230
231 static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn)
232 {
233         struct lowpan_btle_dev *entry;
234         struct lowpan_peer *peer = NULL;
235
236         rcu_read_lock();
237
238         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
239                 peer = __peer_lookup_conn(entry, conn);
240                 if (peer)
241                         break;
242         }
243
244         rcu_read_unlock();
245
246         return peer;
247 }
248
249 static struct lowpan_btle_dev *lookup_dev(struct l2cap_conn *conn)
250 {
251         struct lowpan_btle_dev *entry;
252         struct lowpan_btle_dev *dev = NULL;
253
254         rcu_read_lock();
255
256         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
257                 if (conn->hcon->hdev == entry->hdev) {
258                         dev = entry;
259                         break;
260                 }
261         }
262
263         rcu_read_unlock();
264
265         return dev;
266 }
267
268 static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev)
269 {
270         struct sk_buff *skb_cp;
271
272         skb_cp = skb_copy(skb, GFP_ATOMIC);
273         if (!skb_cp)
274                 return NET_RX_DROP;
275
276         return netif_rx_ni(skb_cp);
277 }
278
279 static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev,
280                            struct lowpan_peer *peer)
281 {
282         const u8 *saddr;
283
284         saddr = peer->lladdr;
285
286         return lowpan_header_decompress(skb, netdev, netdev->dev_addr, saddr);
287 }
288
289 static int recv_pkt(struct sk_buff *skb, struct net_device *dev,
290                     struct lowpan_peer *peer)
291 {
292         struct sk_buff *local_skb;
293         int ret;
294
295         if (!netif_running(dev))
296                 goto drop;
297
298         if (dev->type != ARPHRD_6LOWPAN || !skb->len)
299                 goto drop;
300
301         skb_reset_network_header(skb);
302
303         skb = skb_share_check(skb, GFP_ATOMIC);
304         if (!skb)
305                 goto drop;
306
307         /* check that it's our buffer */
308         if (lowpan_is_ipv6(*skb_network_header(skb))) {
309                 /* Pull off the 1-byte of 6lowpan header. */
310                 skb_pull(skb, 1);
311
312                 /* Copy the packet so that the IPv6 header is
313                  * properly aligned.
314                  */
315                 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
316                                             skb_tailroom(skb), GFP_ATOMIC);
317                 if (!local_skb)
318                         goto drop;
319
320                 local_skb->protocol = htons(ETH_P_IPV6);
321                 local_skb->pkt_type = PACKET_HOST;
322                 local_skb->dev = dev;
323
324                 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
325
326                 if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) {
327                         kfree_skb(local_skb);
328                         goto drop;
329                 }
330
331                 dev->stats.rx_bytes += skb->len;
332                 dev->stats.rx_packets++;
333
334                 consume_skb(local_skb);
335                 consume_skb(skb);
336         } else if (lowpan_is_iphc(*skb_network_header(skb))) {
337                 local_skb = skb_clone(skb, GFP_ATOMIC);
338                 if (!local_skb)
339                         goto drop;
340
341                 local_skb->dev = dev;
342
343                 ret = iphc_decompress(local_skb, dev, peer);
344                 if (ret < 0) {
345                         BT_DBG("iphc_decompress failed: %d", ret);
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                 BT_DBG("unknown packet type");
366                 goto drop;
367         }
368
369         return NET_RX_SUCCESS;
370
371 drop:
372         dev->stats.rx_dropped++;
373         return NET_RX_DROP;
374 }
375
376 /* Packet from BT LE device */
377 static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
378 {
379         struct lowpan_btle_dev *dev;
380         struct lowpan_peer *peer;
381         int err;
382
383         peer = lookup_peer(chan->conn);
384         if (!peer)
385                 return -ENOENT;
386
387         dev = lookup_dev(chan->conn);
388         if (!dev || !dev->netdev)
389                 return -ENOENT;
390
391         err = recv_pkt(skb, dev->netdev, peer);
392         if (err) {
393                 BT_DBG("recv pkt %d", err);
394                 err = -EAGAIN;
395         }
396
397         return err;
398 }
399
400 static int setup_header(struct sk_buff *skb, struct net_device *netdev,
401                         bdaddr_t *peer_addr, u8 *peer_addr_type)
402 {
403         struct in6_addr ipv6_daddr;
404         struct ipv6hdr *hdr;
405         struct lowpan_btle_dev *dev;
406         struct lowpan_peer *peer;
407         u8 *daddr;
408         int err, status = 0;
409
410         hdr = ipv6_hdr(skb);
411
412         dev = lowpan_btle_dev(netdev);
413
414         memcpy(&ipv6_daddr, &hdr->daddr, sizeof(ipv6_daddr));
415
416         if (ipv6_addr_is_multicast(&ipv6_daddr)) {
417                 lowpan_cb(skb)->chan = NULL;
418                 daddr = NULL;
419         } else {
420                 BT_DBG("dest IP %pI6c", &ipv6_daddr);
421
422                 /* The packet might be sent to 6lowpan interface
423                  * because of routing (either via default route
424                  * or user set route) so get peer according to
425                  * the destination address.
426                  */
427                 peer = peer_lookup_dst(dev, &ipv6_daddr, skb);
428                 if (!peer) {
429                         BT_DBG("no such peer");
430                         return -ENOENT;
431                 }
432
433                 daddr = peer->lladdr;
434                 *peer_addr = peer->chan->dst;
435                 *peer_addr_type = peer->chan->dst_type;
436                 lowpan_cb(skb)->chan = peer->chan;
437
438                 status = 1;
439         }
440
441         lowpan_header_compress(skb, netdev, daddr, dev->netdev->dev_addr);
442
443         err = dev_hard_header(skb, netdev, ETH_P_IPV6, NULL, NULL, 0);
444         if (err < 0)
445                 return err;
446
447         return status;
448 }
449
450 static int header_create(struct sk_buff *skb, struct net_device *netdev,
451                          unsigned short type, const void *_daddr,
452                          const void *_saddr, unsigned int len)
453 {
454         if (type != ETH_P_IPV6)
455                 return -EINVAL;
456
457         return 0;
458 }
459
460 /* Packet to BT LE device */
461 static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb,
462                     struct net_device *netdev)
463 {
464         struct msghdr msg;
465         struct kvec iv;
466         int err;
467
468         /* Remember the skb so that we can send EAGAIN to the caller if
469          * we run out of credits.
470          */
471         chan->data = skb;
472
473         iv.iov_base = skb->data;
474         iv.iov_len = skb->len;
475
476         memset(&msg, 0, sizeof(msg));
477         iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, &iv, 1, skb->len);
478
479         err = l2cap_chan_send(chan, &msg, skb->len);
480         if (err > 0) {
481                 netdev->stats.tx_bytes += err;
482                 netdev->stats.tx_packets++;
483                 return 0;
484         }
485
486         if (err < 0)
487                 netdev->stats.tx_errors++;
488
489         return err;
490 }
491
492 static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev)
493 {
494         struct sk_buff *local_skb;
495         struct lowpan_btle_dev *entry;
496         int err = 0;
497
498         rcu_read_lock();
499
500         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
501                 struct lowpan_peer *pentry;
502                 struct lowpan_btle_dev *dev;
503
504                 if (entry->netdev != netdev)
505                         continue;
506
507                 dev = lowpan_btle_dev(entry->netdev);
508
509                 list_for_each_entry_rcu(pentry, &dev->peers, list) {
510                         int ret;
511
512                         local_skb = skb_clone(skb, GFP_ATOMIC);
513
514                         BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
515                                netdev->name,
516                                &pentry->chan->dst, pentry->chan->dst_type,
517                                &pentry->peer_addr, pentry->chan);
518                         ret = send_pkt(pentry->chan, local_skb, netdev);
519                         if (ret < 0)
520                                 err = ret;
521
522                         kfree_skb(local_skb);
523                 }
524         }
525
526         rcu_read_unlock();
527
528         return err;
529 }
530
531 static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev)
532 {
533         int err = 0;
534         bdaddr_t addr;
535         u8 addr_type;
536
537         /* We must take a copy of the skb before we modify/replace the ipv6
538          * header as the header could be used elsewhere
539          */
540         skb = skb_unshare(skb, GFP_ATOMIC);
541         if (!skb)
542                 return NET_XMIT_DROP;
543
544         /* Return values from setup_header()
545          *  <0 - error, packet is dropped
546          *   0 - this is a multicast packet
547          *   1 - this is unicast packet
548          */
549         err = setup_header(skb, netdev, &addr, &addr_type);
550         if (err < 0) {
551                 kfree_skb(skb);
552                 return NET_XMIT_DROP;
553         }
554
555         if (err) {
556                 if (lowpan_cb(skb)->chan) {
557                         BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
558                                netdev->name, &addr, addr_type,
559                                &lowpan_cb(skb)->addr, lowpan_cb(skb)->chan);
560                         err = send_pkt(lowpan_cb(skb)->chan, skb, netdev);
561                 } else {
562                         err = -ENOENT;
563                 }
564         } else {
565                 /* We need to send the packet to every device behind this
566                  * interface.
567                  */
568                 err = send_mcast_pkt(skb, netdev);
569         }
570
571         dev_kfree_skb(skb);
572
573         if (err)
574                 BT_DBG("ERROR: xmit failed (%d)", err);
575
576         return err < 0 ? NET_XMIT_DROP : err;
577 }
578
579 static int bt_dev_init(struct net_device *dev)
580 {
581         netdev_lockdep_set_classes(dev);
582
583         return 0;
584 }
585
586 static const struct net_device_ops netdev_ops = {
587         .ndo_init               = bt_dev_init,
588         .ndo_start_xmit         = bt_xmit,
589 };
590
591 static struct header_ops header_ops = {
592         .create = header_create,
593 };
594
595 static void netdev_setup(struct net_device *dev)
596 {
597         dev->hard_header_len    = 0;
598         dev->needed_tailroom    = 0;
599         dev->flags              = IFF_RUNNING | IFF_MULTICAST;
600         dev->watchdog_timeo     = 0;
601         dev->tx_queue_len       = DEFAULT_TX_QUEUE_LEN;
602
603         dev->netdev_ops         = &netdev_ops;
604         dev->header_ops         = &header_ops;
605         dev->needs_free_netdev  = true;
606 }
607
608 static struct device_type bt_type = {
609         .name   = "bluetooth",
610 };
611
612 static void ifup(struct net_device *netdev)
613 {
614         int err;
615
616         rtnl_lock();
617         err = dev_open(netdev);
618         if (err < 0)
619                 BT_INFO("iface %s cannot be opened (%d)", netdev->name, err);
620         rtnl_unlock();
621 }
622
623 static void ifdown(struct net_device *netdev)
624 {
625         rtnl_lock();
626         dev_close(netdev);
627         rtnl_unlock();
628 }
629
630 static void do_notify_peers(struct work_struct *work)
631 {
632         struct lowpan_btle_dev *dev = container_of(work, struct lowpan_btle_dev,
633                                                    notify_peers.work);
634
635         netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */
636 }
637
638 static bool is_bt_6lowpan(struct hci_conn *hcon)
639 {
640         if (hcon->type != LE_LINK)
641                 return false;
642
643         if (!enable_6lowpan)
644                 return false;
645
646         return true;
647 }
648
649 static struct l2cap_chan *chan_create(void)
650 {
651         struct l2cap_chan *chan;
652
653         chan = l2cap_chan_create();
654         if (!chan)
655                 return NULL;
656
657         l2cap_chan_set_defaults(chan);
658
659         chan->chan_type = L2CAP_CHAN_CONN_ORIENTED;
660         chan->mode = L2CAP_MODE_LE_FLOWCTL;
661         chan->imtu = 1280;
662
663         return chan;
664 }
665
666 static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan,
667                                         struct lowpan_btle_dev *dev,
668                                         bool new_netdev)
669 {
670         struct lowpan_peer *peer;
671
672         peer = kzalloc(sizeof(*peer), GFP_ATOMIC);
673         if (!peer)
674                 return NULL;
675
676         peer->chan = chan;
677         memset(&peer->peer_addr, 0, sizeof(struct in6_addr));
678
679         baswap((void *)peer->lladdr, &chan->dst);
680
681         lowpan_iphc_uncompress_eui48_lladdr(&peer->peer_addr, peer->lladdr);
682
683         spin_lock(&devices_lock);
684         INIT_LIST_HEAD(&peer->list);
685         peer_add(dev, peer);
686         spin_unlock(&devices_lock);
687
688         /* Notifying peers about us needs to be done without locks held */
689         if (new_netdev)
690                 INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers);
691         schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100));
692
693         return peer->chan;
694 }
695
696 static int setup_netdev(struct l2cap_chan *chan, struct lowpan_btle_dev **dev)
697 {
698         struct net_device *netdev;
699         int err = 0;
700
701         netdev = alloc_netdev(LOWPAN_PRIV_SIZE(sizeof(struct lowpan_btle_dev)),
702                               IFACE_NAME_TEMPLATE, NET_NAME_UNKNOWN,
703                               netdev_setup);
704         if (!netdev)
705                 return -ENOMEM;
706
707         netdev->addr_assign_type = NET_ADDR_PERM;
708         baswap((void *)netdev->dev_addr, &chan->src);
709
710         netdev->netdev_ops = &netdev_ops;
711         SET_NETDEV_DEV(netdev, &chan->conn->hcon->hdev->dev);
712         SET_NETDEV_DEVTYPE(netdev, &bt_type);
713
714         *dev = lowpan_btle_dev(netdev);
715         (*dev)->netdev = netdev;
716         (*dev)->hdev = chan->conn->hcon->hdev;
717         INIT_LIST_HEAD(&(*dev)->peers);
718
719         spin_lock(&devices_lock);
720         INIT_LIST_HEAD(&(*dev)->list);
721         list_add_rcu(&(*dev)->list, &bt_6lowpan_devices);
722         spin_unlock(&devices_lock);
723
724         err = lowpan_register_netdev(netdev, LOWPAN_LLTYPE_BTLE);
725         if (err < 0) {
726                 BT_INFO("register_netdev failed %d", err);
727                 spin_lock(&devices_lock);
728                 list_del_rcu(&(*dev)->list);
729                 spin_unlock(&devices_lock);
730                 free_netdev(netdev);
731                 goto out;
732         }
733
734         BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d",
735                netdev->ifindex, &chan->dst, chan->dst_type,
736                &chan->src, chan->src_type);
737         set_bit(__LINK_STATE_PRESENT, &netdev->state);
738
739         return 0;
740
741 out:
742         return err;
743 }
744
745 static inline void chan_ready_cb(struct l2cap_chan *chan)
746 {
747         struct lowpan_btle_dev *dev;
748         bool new_netdev = false;
749
750         dev = lookup_dev(chan->conn);
751
752         BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev);
753
754         if (!dev) {
755                 if (setup_netdev(chan, &dev) < 0) {
756                         l2cap_chan_del(chan, -ENOENT);
757                         return;
758                 }
759                 new_netdev = true;
760         }
761
762         if (!try_module_get(THIS_MODULE))
763                 return;
764
765         add_peer_chan(chan, dev, new_netdev);
766         ifup(dev->netdev);
767 }
768
769 static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan)
770 {
771         struct l2cap_chan *chan;
772
773         chan = chan_create();
774         if (!chan)
775                 return NULL;
776
777         chan->ops = pchan->ops;
778
779         BT_DBG("chan %p pchan %p", chan, pchan);
780
781         return chan;
782 }
783
784 static void delete_netdev(struct work_struct *work)
785 {
786         struct lowpan_btle_dev *entry = container_of(work,
787                                                      struct lowpan_btle_dev,
788                                                      delete_netdev);
789
790         lowpan_unregister_netdev(entry->netdev);
791
792         /* The entry pointer is deleted by the netdev destructor. */
793 }
794
795 static void chan_close_cb(struct l2cap_chan *chan)
796 {
797         struct lowpan_btle_dev *entry;
798         struct lowpan_btle_dev *dev = NULL;
799         struct lowpan_peer *peer;
800         int err = -ENOENT;
801         bool last = false, remove = true;
802
803         BT_DBG("chan %p conn %p", chan, chan->conn);
804
805         if (chan->conn && chan->conn->hcon) {
806                 if (!is_bt_6lowpan(chan->conn->hcon))
807                         return;
808
809                 /* If conn is set, then the netdev is also there and we should
810                  * not remove it.
811                  */
812                 remove = false;
813         }
814
815         spin_lock(&devices_lock);
816
817         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
818                 dev = lowpan_btle_dev(entry->netdev);
819                 peer = __peer_lookup_chan(dev, chan);
820                 if (peer) {
821                         last = peer_del(dev, peer);
822                         err = 0;
823
824                         BT_DBG("dev %p removing %speer %p", dev,
825                                last ? "last " : "1 ", peer);
826                         BT_DBG("chan %p orig refcnt %d", chan,
827                                kref_read(&chan->kref));
828
829                         l2cap_chan_put(chan);
830                         break;
831                 }
832         }
833
834         if (!err && last && dev && !atomic_read(&dev->peer_count)) {
835                 spin_unlock(&devices_lock);
836
837                 cancel_delayed_work_sync(&dev->notify_peers);
838
839                 ifdown(dev->netdev);
840
841                 if (remove) {
842                         INIT_WORK(&entry->delete_netdev, delete_netdev);
843                         schedule_work(&entry->delete_netdev);
844                 }
845         } else {
846                 spin_unlock(&devices_lock);
847         }
848
849         return;
850 }
851
852 static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err)
853 {
854         BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn,
855                state_to_string(state), err);
856 }
857
858 static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan,
859                                          unsigned long hdr_len,
860                                          unsigned long len, int nb)
861 {
862         /* Note that we must allocate using GFP_ATOMIC here as
863          * this function is called originally from netdev hard xmit
864          * function in atomic context.
865          */
866         return bt_skb_alloc(hdr_len + len, GFP_ATOMIC);
867 }
868
869 static void chan_suspend_cb(struct l2cap_chan *chan)
870 {
871         struct lowpan_btle_dev *dev;
872
873         BT_DBG("chan %p suspend", chan);
874
875         dev = lookup_dev(chan->conn);
876         if (!dev || !dev->netdev)
877                 return;
878
879         netif_stop_queue(dev->netdev);
880 }
881
882 static void chan_resume_cb(struct l2cap_chan *chan)
883 {
884         struct lowpan_btle_dev *dev;
885
886         BT_DBG("chan %p resume", chan);
887
888         dev = lookup_dev(chan->conn);
889         if (!dev || !dev->netdev)
890                 return;
891
892         netif_wake_queue(dev->netdev);
893 }
894
895 static long chan_get_sndtimeo_cb(struct l2cap_chan *chan)
896 {
897         return L2CAP_CONN_TIMEOUT;
898 }
899
900 static const struct l2cap_ops bt_6lowpan_chan_ops = {
901         .name                   = "L2CAP 6LoWPAN channel",
902         .new_connection         = chan_new_conn_cb,
903         .recv                   = chan_recv_cb,
904         .close                  = chan_close_cb,
905         .state_change           = chan_state_change_cb,
906         .ready                  = chan_ready_cb,
907         .resume                 = chan_resume_cb,
908         .suspend                = chan_suspend_cb,
909         .get_sndtimeo           = chan_get_sndtimeo_cb,
910         .alloc_skb              = chan_alloc_skb_cb,
911
912         .teardown               = l2cap_chan_no_teardown,
913         .defer                  = l2cap_chan_no_defer,
914         .set_shutdown           = l2cap_chan_no_set_shutdown,
915 };
916
917 static inline __u8 bdaddr_type(__u8 type)
918 {
919         if (type == ADDR_LE_DEV_PUBLIC)
920                 return BDADDR_LE_PUBLIC;
921         else
922                 return BDADDR_LE_RANDOM;
923 }
924
925 static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type)
926 {
927         struct l2cap_chan *chan;
928         int err;
929
930         chan = chan_create();
931         if (!chan)
932                 return -EINVAL;
933
934         chan->ops = &bt_6lowpan_chan_ops;
935
936         err = l2cap_chan_connect(chan, cpu_to_le16(L2CAP_PSM_IPSP), 0,
937                                  addr, dst_type);
938
939         BT_DBG("chan %p err %d", chan, err);
940         if (err < 0)
941                 l2cap_chan_put(chan);
942
943         return err;
944 }
945
946 static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type)
947 {
948         struct lowpan_peer *peer;
949
950         BT_DBG("conn %p dst type %d", conn, dst_type);
951
952         peer = lookup_peer(conn);
953         if (!peer)
954                 return -ENOENT;
955
956         BT_DBG("peer %p chan %p", peer, peer->chan);
957
958         l2cap_chan_close(peer->chan, ENOENT);
959
960         return 0;
961 }
962
963 static struct l2cap_chan *bt_6lowpan_listen(void)
964 {
965         bdaddr_t *addr = BDADDR_ANY;
966         struct l2cap_chan *chan;
967         int err;
968
969         if (!enable_6lowpan)
970                 return NULL;
971
972         chan = chan_create();
973         if (!chan)
974                 return NULL;
975
976         chan->ops = &bt_6lowpan_chan_ops;
977         chan->state = BT_LISTEN;
978         chan->src_type = BDADDR_LE_PUBLIC;
979
980         atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
981
982         BT_DBG("chan %p src type %d", chan, chan->src_type);
983
984         err = l2cap_add_psm(chan, addr, cpu_to_le16(L2CAP_PSM_IPSP));
985         if (err) {
986                 l2cap_chan_put(chan);
987                 BT_ERR("psm cannot be added err %d", err);
988                 return NULL;
989         }
990
991         return chan;
992 }
993
994 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type,
995                           struct l2cap_conn **conn)
996 {
997         struct hci_conn *hcon;
998         struct hci_dev *hdev;
999         int n;
1000
1001         n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu",
1002                    &addr->b[5], &addr->b[4], &addr->b[3],
1003                    &addr->b[2], &addr->b[1], &addr->b[0],
1004                    addr_type);
1005
1006         if (n < 7)
1007                 return -EINVAL;
1008
1009         /* The LE_PUBLIC address type is ignored because of BDADDR_ANY */
1010         hdev = hci_get_route(addr, BDADDR_ANY, BDADDR_LE_PUBLIC);
1011         if (!hdev)
1012                 return -ENOENT;
1013
1014         hci_dev_lock(hdev);
1015         hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type);
1016         hci_dev_unlock(hdev);
1017
1018         if (!hcon)
1019                 return -ENOENT;
1020
1021         *conn = (struct l2cap_conn *)hcon->l2cap_data;
1022
1023         BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type);
1024
1025         return 0;
1026 }
1027
1028 static void disconnect_all_peers(void)
1029 {
1030         struct lowpan_btle_dev *entry;
1031         struct lowpan_peer *peer, *tmp_peer, *new_peer;
1032         struct list_head peers;
1033
1034         INIT_LIST_HEAD(&peers);
1035
1036         /* We make a separate list of peers as the close_cb() will
1037          * modify the device peers list so it is better not to mess
1038          * with the same list at the same time.
1039          */
1040
1041         rcu_read_lock();
1042
1043         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1044                 list_for_each_entry_rcu(peer, &entry->peers, list) {
1045                         new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC);
1046                         if (!new_peer)
1047                                 break;
1048
1049                         new_peer->chan = peer->chan;
1050                         INIT_LIST_HEAD(&new_peer->list);
1051
1052                         list_add(&new_peer->list, &peers);
1053                 }
1054         }
1055
1056         rcu_read_unlock();
1057
1058         spin_lock(&devices_lock);
1059         list_for_each_entry_safe(peer, tmp_peer, &peers, list) {
1060                 l2cap_chan_close(peer->chan, ENOENT);
1061
1062                 list_del_rcu(&peer->list);
1063                 kfree_rcu(peer, rcu);
1064         }
1065         spin_unlock(&devices_lock);
1066 }
1067
1068 struct set_enable {
1069         struct work_struct work;
1070         bool flag;
1071 };
1072
1073 static void do_enable_set(struct work_struct *work)
1074 {
1075         struct set_enable *set_enable = container_of(work,
1076                                                      struct set_enable, work);
1077
1078         if (!set_enable->flag || enable_6lowpan != set_enable->flag)
1079                 /* Disconnect existing connections if 6lowpan is
1080                  * disabled
1081                  */
1082                 disconnect_all_peers();
1083
1084         enable_6lowpan = set_enable->flag;
1085
1086         mutex_lock(&set_lock);
1087         if (listen_chan) {
1088                 l2cap_chan_close(listen_chan, 0);
1089                 l2cap_chan_put(listen_chan);
1090         }
1091
1092         listen_chan = bt_6lowpan_listen();
1093         mutex_unlock(&set_lock);
1094
1095         kfree(set_enable);
1096 }
1097
1098 static int lowpan_enable_set(void *data, u64 val)
1099 {
1100         struct set_enable *set_enable;
1101
1102         set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL);
1103         if (!set_enable)
1104                 return -ENOMEM;
1105
1106         set_enable->flag = !!val;
1107         INIT_WORK(&set_enable->work, do_enable_set);
1108
1109         schedule_work(&set_enable->work);
1110
1111         return 0;
1112 }
1113
1114 static int lowpan_enable_get(void *data, u64 *val)
1115 {
1116         *val = enable_6lowpan;
1117         return 0;
1118 }
1119
1120 DEFINE_SIMPLE_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get,
1121                         lowpan_enable_set, "%llu\n");
1122
1123 static ssize_t lowpan_control_write(struct file *fp,
1124                                     const char __user *user_buffer,
1125                                     size_t count,
1126                                     loff_t *position)
1127 {
1128         char buf[32];
1129         size_t buf_size = min(count, sizeof(buf) - 1);
1130         int ret;
1131         bdaddr_t addr;
1132         u8 addr_type;
1133         struct l2cap_conn *conn = NULL;
1134
1135         if (copy_from_user(buf, user_buffer, buf_size))
1136                 return -EFAULT;
1137
1138         buf[buf_size] = '\0';
1139
1140         if (memcmp(buf, "connect ", 8) == 0) {
1141                 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn);
1142                 if (ret == -EINVAL)
1143                         return ret;
1144
1145                 mutex_lock(&set_lock);
1146                 if (listen_chan) {
1147                         l2cap_chan_close(listen_chan, 0);
1148                         l2cap_chan_put(listen_chan);
1149                         listen_chan = NULL;
1150                 }
1151                 mutex_unlock(&set_lock);
1152
1153                 if (conn) {
1154                         struct lowpan_peer *peer;
1155
1156                         if (!is_bt_6lowpan(conn->hcon))
1157                                 return -EINVAL;
1158
1159                         peer = lookup_peer(conn);
1160                         if (peer) {
1161                                 BT_DBG("6LoWPAN connection already exists");
1162                                 return -EALREADY;
1163                         }
1164
1165                         BT_DBG("conn %p dst %pMR type %d user %d", conn,
1166                                &conn->hcon->dst, conn->hcon->dst_type,
1167                                addr_type);
1168                 }
1169
1170                 ret = bt_6lowpan_connect(&addr, addr_type);
1171                 if (ret < 0)
1172                         return ret;
1173
1174                 return count;
1175         }
1176
1177         if (memcmp(buf, "disconnect ", 11) == 0) {
1178                 ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn);
1179                 if (ret < 0)
1180                         return ret;
1181
1182                 ret = bt_6lowpan_disconnect(conn, addr_type);
1183                 if (ret < 0)
1184                         return ret;
1185
1186                 return count;
1187         }
1188
1189         return count;
1190 }
1191
1192 static int lowpan_control_show(struct seq_file *f, void *ptr)
1193 {
1194         struct lowpan_btle_dev *entry;
1195         struct lowpan_peer *peer;
1196
1197         spin_lock(&devices_lock);
1198
1199         list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1200                 list_for_each_entry(peer, &entry->peers, list)
1201                         seq_printf(f, "%pMR (type %u)\n",
1202                                    &peer->chan->dst, peer->chan->dst_type);
1203         }
1204
1205         spin_unlock(&devices_lock);
1206
1207         return 0;
1208 }
1209
1210 static int lowpan_control_open(struct inode *inode, struct file *file)
1211 {
1212         return single_open(file, lowpan_control_show, inode->i_private);
1213 }
1214
1215 static const struct file_operations lowpan_control_fops = {
1216         .open           = lowpan_control_open,
1217         .read           = seq_read,
1218         .write          = lowpan_control_write,
1219         .llseek         = seq_lseek,
1220         .release        = single_release,
1221 };
1222
1223 static void disconnect_devices(void)
1224 {
1225         struct lowpan_btle_dev *entry, *tmp, *new_dev;
1226         struct list_head devices;
1227
1228         INIT_LIST_HEAD(&devices);
1229
1230         /* We make a separate list of devices because the unregister_netdev()
1231          * will call device_event() which will also want to modify the same
1232          * devices list.
1233          */
1234
1235         rcu_read_lock();
1236
1237         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1238                 new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC);
1239                 if (!new_dev)
1240                         break;
1241
1242                 new_dev->netdev = entry->netdev;
1243                 INIT_LIST_HEAD(&new_dev->list);
1244
1245                 list_add_rcu(&new_dev->list, &devices);
1246         }
1247
1248         rcu_read_unlock();
1249
1250         list_for_each_entry_safe(entry, tmp, &devices, list) {
1251                 ifdown(entry->netdev);
1252                 BT_DBG("Unregistering netdev %s %p",
1253                        entry->netdev->name, entry->netdev);
1254                 lowpan_unregister_netdev(entry->netdev);
1255                 kfree(entry);
1256         }
1257 }
1258
1259 static int device_event(struct notifier_block *unused,
1260                         unsigned long event, void *ptr)
1261 {
1262         struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
1263         struct lowpan_btle_dev *entry;
1264
1265         if (netdev->type != ARPHRD_6LOWPAN)
1266                 return NOTIFY_DONE;
1267
1268         switch (event) {
1269         case NETDEV_UNREGISTER:
1270                 spin_lock(&devices_lock);
1271                 list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1272                         if (entry->netdev == netdev) {
1273                                 BT_DBG("Unregistered netdev %s %p",
1274                                        netdev->name, netdev);
1275                                 list_del(&entry->list);
1276                                 break;
1277                         }
1278                 }
1279                 spin_unlock(&devices_lock);
1280                 break;
1281         }
1282
1283         return NOTIFY_DONE;
1284 }
1285
1286 static struct notifier_block bt_6lowpan_dev_notifier = {
1287         .notifier_call = device_event,
1288 };
1289
1290 static int __init bt_6lowpan_init(void)
1291 {
1292         lowpan_enable_debugfs = debugfs_create_file("6lowpan_enable", 0644,
1293                                                     bt_debugfs, NULL,
1294                                                     &lowpan_enable_fops);
1295         lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644,
1296                                                      bt_debugfs, NULL,
1297                                                      &lowpan_control_fops);
1298
1299         return register_netdevice_notifier(&bt_6lowpan_dev_notifier);
1300 }
1301
1302 static void __exit bt_6lowpan_exit(void)
1303 {
1304         debugfs_remove(lowpan_enable_debugfs);
1305         debugfs_remove(lowpan_control_debugfs);
1306
1307         if (listen_chan) {
1308                 l2cap_chan_close(listen_chan, 0);
1309                 l2cap_chan_put(listen_chan);
1310         }
1311
1312         disconnect_devices();
1313
1314         unregister_netdevice_notifier(&bt_6lowpan_dev_notifier);
1315 }
1316
1317 module_init(bt_6lowpan_init);
1318 module_exit(bt_6lowpan_exit);
1319
1320 MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>");
1321 MODULE_DESCRIPTION("Bluetooth 6LoWPAN");
1322 MODULE_VERSION(VERSION);
1323 MODULE_LICENSE("GPL");