Merge tag 'irqchip-urgent-3.19' of git://git.infradead.org/users/jcooper/linux into...
[firefly-linux-kernel-4.4.55.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
24 #include <net/af_ieee802154.h> /* to get the address type */
25
26 #include <net/bluetooth/bluetooth.h>
27 #include <net/bluetooth/hci_core.h>
28 #include <net/bluetooth/l2cap.h>
29
30 #include <net/6lowpan.h> /* for the compression support */
31
32 #define VERSION "0.1"
33
34 static struct dentry *lowpan_psm_debugfs;
35 static struct dentry *lowpan_control_debugfs;
36
37 #define IFACE_NAME_TEMPLATE "bt%d"
38 #define EUI64_ADDR_LEN 8
39
40 struct skb_cb {
41         struct in6_addr addr;
42         struct in6_addr gw;
43         struct l2cap_chan *chan;
44         int status;
45 };
46 #define lowpan_cb(skb) ((struct skb_cb *)((skb)->cb))
47
48 /* The devices list contains those devices that we are acting
49  * as a proxy. The BT 6LoWPAN device is a virtual device that
50  * connects to the Bluetooth LE device. The real connection to
51  * BT device is done via l2cap layer. There exists one
52  * virtual device / one BT 6LoWPAN network (=hciX device).
53  * The list contains struct lowpan_dev elements.
54  */
55 static LIST_HEAD(bt_6lowpan_devices);
56 static DEFINE_SPINLOCK(devices_lock);
57
58 /* If psm is set to 0 (default value), then 6lowpan is disabled.
59  * Other values are used to indicate a Protocol Service Multiplexer
60  * value for 6lowpan.
61  */
62 static u16 psm_6lowpan;
63
64 /* We are listening incoming connections via this channel
65  */
66 static struct l2cap_chan *listen_chan;
67
68 struct lowpan_peer {
69         struct list_head list;
70         struct rcu_head rcu;
71         struct l2cap_chan *chan;
72
73         /* peer addresses in various formats */
74         unsigned char eui64_addr[EUI64_ADDR_LEN];
75         struct in6_addr peer_addr;
76 };
77
78 struct lowpan_dev {
79         struct list_head list;
80
81         struct hci_dev *hdev;
82         struct net_device *netdev;
83         struct list_head peers;
84         atomic_t peer_count; /* number of items in peers list */
85
86         struct work_struct delete_netdev;
87         struct delayed_work notify_peers;
88 };
89
90 static inline struct lowpan_dev *lowpan_dev(const struct net_device *netdev)
91 {
92         return netdev_priv(netdev);
93 }
94
95 static inline void peer_add(struct lowpan_dev *dev, struct lowpan_peer *peer)
96 {
97         list_add_rcu(&peer->list, &dev->peers);
98         atomic_inc(&dev->peer_count);
99 }
100
101 static inline bool peer_del(struct lowpan_dev *dev, struct lowpan_peer *peer)
102 {
103         list_del_rcu(&peer->list);
104         kfree_rcu(peer, rcu);
105
106         module_put(THIS_MODULE);
107
108         if (atomic_dec_and_test(&dev->peer_count)) {
109                 BT_DBG("last peer");
110                 return true;
111         }
112
113         return false;
114 }
115
116 static inline struct lowpan_peer *peer_lookup_ba(struct lowpan_dev *dev,
117                                                  bdaddr_t *ba, __u8 type)
118 {
119         struct lowpan_peer *peer;
120
121         BT_DBG("peers %d addr %pMR type %d", atomic_read(&dev->peer_count),
122                ba, type);
123
124         rcu_read_lock();
125
126         list_for_each_entry_rcu(peer, &dev->peers, list) {
127                 BT_DBG("dst addr %pMR dst type %d",
128                        &peer->chan->dst, peer->chan->dst_type);
129
130                 if (bacmp(&peer->chan->dst, ba))
131                         continue;
132
133                 if (type == peer->chan->dst_type) {
134                         rcu_read_unlock();
135                         return peer;
136                 }
137         }
138
139         rcu_read_unlock();
140
141         return NULL;
142 }
143
144 static inline struct lowpan_peer *__peer_lookup_chan(struct lowpan_dev *dev,
145                                                      struct l2cap_chan *chan)
146 {
147         struct lowpan_peer *peer;
148
149         list_for_each_entry_rcu(peer, &dev->peers, list) {
150                 if (peer->chan == chan)
151                         return peer;
152         }
153
154         return NULL;
155 }
156
157 static inline struct lowpan_peer *__peer_lookup_conn(struct lowpan_dev *dev,
158                                                      struct l2cap_conn *conn)
159 {
160         struct lowpan_peer *peer;
161
162         list_for_each_entry_rcu(peer, &dev->peers, list) {
163                 if (peer->chan->conn == conn)
164                         return peer;
165         }
166
167         return NULL;
168 }
169
170 static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_dev *dev,
171                                                   struct in6_addr *daddr,
172                                                   struct sk_buff *skb)
173 {
174         struct lowpan_peer *peer;
175         struct in6_addr *nexthop;
176         struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
177         int count = atomic_read(&dev->peer_count);
178
179         BT_DBG("peers %d addr %pI6c rt %p", count, daddr, rt);
180
181         /* If we have multiple 6lowpan peers, then check where we should
182          * send the packet. If only one peer exists, then we can send the
183          * packet right away.
184          */
185         if (count == 1) {
186                 rcu_read_lock();
187                 peer = list_first_or_null_rcu(&dev->peers, struct lowpan_peer,
188                                               list);
189                 rcu_read_unlock();
190                 return peer;
191         }
192
193         if (!rt) {
194                 nexthop = &lowpan_cb(skb)->gw;
195
196                 if (ipv6_addr_any(nexthop))
197                         return NULL;
198         } else {
199                 nexthop = rt6_nexthop(rt);
200
201                 /* We need to remember the address because it is needed
202                  * by bt_xmit() when sending the packet. In bt_xmit(), the
203                  * destination routing info is not set.
204                  */
205                 memcpy(&lowpan_cb(skb)->gw, nexthop, sizeof(struct in6_addr));
206         }
207
208         BT_DBG("gw %pI6c", nexthop);
209
210         rcu_read_lock();
211
212         list_for_each_entry_rcu(peer, &dev->peers, list) {
213                 BT_DBG("dst addr %pMR dst type %d ip %pI6c",
214                        &peer->chan->dst, peer->chan->dst_type,
215                        &peer->peer_addr);
216
217                 if (!ipv6_addr_cmp(&peer->peer_addr, nexthop)) {
218                         rcu_read_unlock();
219                         return peer;
220                 }
221         }
222
223         rcu_read_unlock();
224
225         return NULL;
226 }
227
228 static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn)
229 {
230         struct lowpan_dev *entry;
231         struct lowpan_peer *peer = NULL;
232
233         rcu_read_lock();
234
235         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
236                 peer = __peer_lookup_conn(entry, conn);
237                 if (peer)
238                         break;
239         }
240
241         rcu_read_unlock();
242
243         return peer;
244 }
245
246 static struct lowpan_dev *lookup_dev(struct l2cap_conn *conn)
247 {
248         struct lowpan_dev *entry;
249         struct lowpan_dev *dev = NULL;
250
251         rcu_read_lock();
252
253         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
254                 if (conn->hcon->hdev == entry->hdev) {
255                         dev = entry;
256                         break;
257                 }
258         }
259
260         rcu_read_unlock();
261
262         return dev;
263 }
264
265 static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev)
266 {
267         struct sk_buff *skb_cp;
268
269         skb_cp = skb_copy(skb, GFP_ATOMIC);
270         if (!skb_cp)
271                 return NET_RX_DROP;
272
273         return netif_rx(skb_cp);
274 }
275
276 static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev,
277                            struct l2cap_chan *chan)
278 {
279         const u8 *saddr, *daddr;
280         u8 iphc0, iphc1;
281         struct lowpan_dev *dev;
282         struct lowpan_peer *peer;
283
284         dev = lowpan_dev(netdev);
285
286         rcu_read_lock();
287         peer = __peer_lookup_chan(dev, chan);
288         rcu_read_unlock();
289         if (!peer)
290                 return -EINVAL;
291
292         saddr = peer->eui64_addr;
293         daddr = dev->netdev->dev_addr;
294
295         /* at least two bytes will be used for the encoding */
296         if (skb->len < 2)
297                 return -EINVAL;
298
299         if (lowpan_fetch_skb_u8(skb, &iphc0))
300                 return -EINVAL;
301
302         if (lowpan_fetch_skb_u8(skb, &iphc1))
303                 return -EINVAL;
304
305         return lowpan_header_decompress(skb, netdev,
306                                         saddr, IEEE802154_ADDR_LONG,
307                                         EUI64_ADDR_LEN, daddr,
308                                         IEEE802154_ADDR_LONG, EUI64_ADDR_LEN,
309                                         iphc0, iphc1);
310
311 }
312
313 static int recv_pkt(struct sk_buff *skb, struct net_device *dev,
314                     struct l2cap_chan *chan)
315 {
316         struct sk_buff *local_skb;
317         int ret;
318
319         if (!netif_running(dev))
320                 goto drop;
321
322         if (dev->type != ARPHRD_6LOWPAN)
323                 goto drop;
324
325         skb = skb_share_check(skb, GFP_ATOMIC);
326         if (!skb)
327                 goto drop;
328
329         /* check that it's our buffer */
330         if (skb->data[0] == LOWPAN_DISPATCH_IPV6) {
331                 /* Copy the packet so that the IPv6 header is
332                  * properly aligned.
333                  */
334                 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
335                                             skb_tailroom(skb), GFP_ATOMIC);
336                 if (!local_skb)
337                         goto drop;
338
339                 local_skb->protocol = htons(ETH_P_IPV6);
340                 local_skb->pkt_type = PACKET_HOST;
341
342                 skb_reset_network_header(local_skb);
343                 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
344
345                 if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) {
346                         kfree_skb(local_skb);
347                         goto drop;
348                 }
349
350                 dev->stats.rx_bytes += skb->len;
351                 dev->stats.rx_packets++;
352
353                 consume_skb(local_skb);
354                 consume_skb(skb);
355         } else {
356                 switch (skb->data[0] & 0xe0) {
357                 case LOWPAN_DISPATCH_IPHC:      /* ipv6 datagram */
358                         local_skb = skb_clone(skb, GFP_ATOMIC);
359                         if (!local_skb)
360                                 goto drop;
361
362                         ret = iphc_decompress(local_skb, dev, chan);
363                         if (ret < 0) {
364                                 kfree_skb(local_skb);
365                                 goto drop;
366                         }
367
368                         local_skb->protocol = htons(ETH_P_IPV6);
369                         local_skb->pkt_type = PACKET_HOST;
370                         local_skb->dev = dev;
371
372                         if (give_skb_to_upper(local_skb, dev)
373                                         != NET_RX_SUCCESS) {
374                                 kfree_skb(local_skb);
375                                 goto drop;
376                         }
377
378                         dev->stats.rx_bytes += skb->len;
379                         dev->stats.rx_packets++;
380
381                         consume_skb(local_skb);
382                         consume_skb(skb);
383                         break;
384                 default:
385                         break;
386                 }
387         }
388
389         return NET_RX_SUCCESS;
390
391 drop:
392         dev->stats.rx_dropped++;
393         kfree_skb(skb);
394         return NET_RX_DROP;
395 }
396
397 /* Packet from BT LE device */
398 static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
399 {
400         struct lowpan_dev *dev;
401         struct lowpan_peer *peer;
402         int err;
403
404         peer = lookup_peer(chan->conn);
405         if (!peer)
406                 return -ENOENT;
407
408         dev = lookup_dev(chan->conn);
409         if (!dev || !dev->netdev)
410                 return -ENOENT;
411
412         err = recv_pkt(skb, dev->netdev, chan);
413         if (err) {
414                 BT_DBG("recv pkt %d", err);
415                 err = -EAGAIN;
416         }
417
418         return err;
419 }
420
421 static u8 get_addr_type_from_eui64(u8 byte)
422 {
423         /* Is universal(0) or local(1) bit */
424         return ((byte & 0x02) ? BDADDR_LE_RANDOM : BDADDR_LE_PUBLIC);
425 }
426
427 static void copy_to_bdaddr(struct in6_addr *ip6_daddr, bdaddr_t *addr)
428 {
429         u8 *eui64 = ip6_daddr->s6_addr + 8;
430
431         addr->b[0] = eui64[7];
432         addr->b[1] = eui64[6];
433         addr->b[2] = eui64[5];
434         addr->b[3] = eui64[2];
435         addr->b[4] = eui64[1];
436         addr->b[5] = eui64[0];
437 }
438
439 static void convert_dest_bdaddr(struct in6_addr *ip6_daddr,
440                                 bdaddr_t *addr, u8 *addr_type)
441 {
442         copy_to_bdaddr(ip6_daddr, addr);
443
444         /* We need to toggle the U/L bit that we got from IPv6 address
445          * so that we get the proper address and type of the BD address.
446          */
447         addr->b[5] ^= 0x02;
448
449         *addr_type = get_addr_type_from_eui64(addr->b[5]);
450 }
451
452 static int setup_header(struct sk_buff *skb, struct net_device *netdev,
453                         bdaddr_t *peer_addr, u8 *peer_addr_type)
454 {
455         struct in6_addr ipv6_daddr;
456         struct lowpan_dev *dev;
457         struct lowpan_peer *peer;
458         bdaddr_t addr, *any = BDADDR_ANY;
459         u8 *daddr = any->b;
460         int err, status = 0;
461
462         dev = lowpan_dev(netdev);
463
464         memcpy(&ipv6_daddr, &lowpan_cb(skb)->addr, sizeof(ipv6_daddr));
465
466         if (ipv6_addr_is_multicast(&ipv6_daddr)) {
467                 lowpan_cb(skb)->chan = NULL;
468         } else {
469                 u8 addr_type;
470
471                 /* Get destination BT device from skb.
472                  * If there is no such peer then discard the packet.
473                  */
474                 convert_dest_bdaddr(&ipv6_daddr, &addr, &addr_type);
475
476                 BT_DBG("dest addr %pMR type %d IP %pI6c", &addr,
477                        addr_type, &ipv6_daddr);
478
479                 peer = peer_lookup_ba(dev, &addr, addr_type);
480                 if (!peer) {
481                         /* The packet might be sent to 6lowpan interface
482                          * because of routing (either via default route
483                          * or user set route) so get peer according to
484                          * the destination address.
485                          */
486                         peer = peer_lookup_dst(dev, &ipv6_daddr, skb);
487                         if (!peer) {
488                                 BT_DBG("no such peer %pMR found", &addr);
489                                 return -ENOENT;
490                         }
491                 }
492
493                 daddr = peer->eui64_addr;
494                 *peer_addr = addr;
495                 *peer_addr_type = addr_type;
496                 lowpan_cb(skb)->chan = peer->chan;
497
498                 status = 1;
499         }
500
501         lowpan_header_compress(skb, netdev, ETH_P_IPV6, daddr,
502                                dev->netdev->dev_addr, skb->len);
503
504         err = dev_hard_header(skb, netdev, ETH_P_IPV6, NULL, NULL, 0);
505         if (err < 0)
506                 return err;
507
508         return status;
509 }
510
511 static int header_create(struct sk_buff *skb, struct net_device *netdev,
512                          unsigned short type, const void *_daddr,
513                          const void *_saddr, unsigned int len)
514 {
515         struct ipv6hdr *hdr;
516
517         if (type != ETH_P_IPV6)
518                 return -EINVAL;
519
520         hdr = ipv6_hdr(skb);
521
522         memcpy(&lowpan_cb(skb)->addr, &hdr->daddr, sizeof(struct in6_addr));
523
524         return 0;
525 }
526
527 /* Packet to BT LE device */
528 static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb,
529                     struct net_device *netdev)
530 {
531         struct msghdr msg;
532         struct kvec iv;
533         int err;
534
535         /* Remember the skb so that we can send EAGAIN to the caller if
536          * we run out of credits.
537          */
538         chan->data = skb;
539
540         iv.iov_base = skb->data;
541         iv.iov_len = skb->len;
542
543         memset(&msg, 0, sizeof(msg));
544         iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, &iv, 1, skb->len);
545
546         err = l2cap_chan_send(chan, &msg, skb->len);
547         if (err > 0) {
548                 netdev->stats.tx_bytes += err;
549                 netdev->stats.tx_packets++;
550                 return 0;
551         }
552
553         if (!err)
554                 err = lowpan_cb(skb)->status;
555
556         if (err < 0) {
557                 if (err == -EAGAIN)
558                         netdev->stats.tx_dropped++;
559                 else
560                         netdev->stats.tx_errors++;
561         }
562
563         return err;
564 }
565
566 static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev)
567 {
568         struct sk_buff *local_skb;
569         struct lowpan_dev *entry;
570         int err = 0;
571
572         rcu_read_lock();
573
574         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
575                 struct lowpan_peer *pentry;
576                 struct lowpan_dev *dev;
577
578                 if (entry->netdev != netdev)
579                         continue;
580
581                 dev = lowpan_dev(entry->netdev);
582
583                 list_for_each_entry_rcu(pentry, &dev->peers, list) {
584                         int ret;
585
586                         local_skb = skb_clone(skb, GFP_ATOMIC);
587
588                         BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
589                                netdev->name,
590                                &pentry->chan->dst, pentry->chan->dst_type,
591                                &pentry->peer_addr, pentry->chan);
592                         ret = send_pkt(pentry->chan, local_skb, netdev);
593                         if (ret < 0)
594                                 err = ret;
595
596                         kfree_skb(local_skb);
597                 }
598         }
599
600         rcu_read_unlock();
601
602         return err;
603 }
604
605 static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev)
606 {
607         int err = 0;
608         bdaddr_t addr;
609         u8 addr_type;
610
611         /* We must take a copy of the skb before we modify/replace the ipv6
612          * header as the header could be used elsewhere
613          */
614         skb = skb_unshare(skb, GFP_ATOMIC);
615         if (!skb)
616                 return NET_XMIT_DROP;
617
618         /* Return values from setup_header()
619          *  <0 - error, packet is dropped
620          *   0 - this is a multicast packet
621          *   1 - this is unicast packet
622          */
623         err = setup_header(skb, netdev, &addr, &addr_type);
624         if (err < 0) {
625                 kfree_skb(skb);
626                 return NET_XMIT_DROP;
627         }
628
629         if (err) {
630                 if (lowpan_cb(skb)->chan) {
631                         BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
632                                netdev->name, &addr, addr_type,
633                                &lowpan_cb(skb)->addr, lowpan_cb(skb)->chan);
634                         err = send_pkt(lowpan_cb(skb)->chan, skb, netdev);
635                 } else {
636                         err = -ENOENT;
637                 }
638         } else {
639                 /* We need to send the packet to every device behind this
640                  * interface.
641                  */
642                 err = send_mcast_pkt(skb, netdev);
643         }
644
645         dev_kfree_skb(skb);
646
647         if (err)
648                 BT_DBG("ERROR: xmit failed (%d)", err);
649
650         return err < 0 ? NET_XMIT_DROP : err;
651 }
652
653 static struct lock_class_key bt_tx_busylock;
654 static struct lock_class_key bt_netdev_xmit_lock_key;
655
656 static void bt_set_lockdep_class_one(struct net_device *dev,
657                                      struct netdev_queue *txq,
658                                      void *_unused)
659 {
660         lockdep_set_class(&txq->_xmit_lock, &bt_netdev_xmit_lock_key);
661 }
662
663 static int bt_dev_init(struct net_device *dev)
664 {
665         netdev_for_each_tx_queue(dev, bt_set_lockdep_class_one, NULL);
666         dev->qdisc_tx_busylock = &bt_tx_busylock;
667
668         return 0;
669 }
670
671 static const struct net_device_ops netdev_ops = {
672         .ndo_init               = bt_dev_init,
673         .ndo_start_xmit         = bt_xmit,
674 };
675
676 static struct header_ops header_ops = {
677         .create = header_create,
678 };
679
680 static void netdev_setup(struct net_device *dev)
681 {
682         dev->addr_len           = EUI64_ADDR_LEN;
683         dev->type               = ARPHRD_6LOWPAN;
684
685         dev->hard_header_len    = 0;
686         dev->needed_tailroom    = 0;
687         dev->mtu                = IPV6_MIN_MTU;
688         dev->tx_queue_len       = 0;
689         dev->flags              = IFF_RUNNING | IFF_POINTOPOINT |
690                                   IFF_MULTICAST;
691         dev->watchdog_timeo     = 0;
692
693         dev->netdev_ops         = &netdev_ops;
694         dev->header_ops         = &header_ops;
695         dev->destructor         = free_netdev;
696 }
697
698 static struct device_type bt_type = {
699         .name   = "bluetooth",
700 };
701
702 static void set_addr(u8 *eui, u8 *addr, u8 addr_type)
703 {
704         /* addr is the BT address in little-endian format */
705         eui[0] = addr[5];
706         eui[1] = addr[4];
707         eui[2] = addr[3];
708         eui[3] = 0xFF;
709         eui[4] = 0xFE;
710         eui[5] = addr[2];
711         eui[6] = addr[1];
712         eui[7] = addr[0];
713
714         /* Universal/local bit set, BT 6lowpan draft ch. 3.2.1 */
715         if (addr_type == BDADDR_LE_PUBLIC)
716                 eui[0] &= ~0x02;
717         else
718                 eui[0] |= 0x02;
719
720         BT_DBG("type %d addr %*phC", addr_type, 8, eui);
721 }
722
723 static void set_dev_addr(struct net_device *netdev, bdaddr_t *addr,
724                          u8 addr_type)
725 {
726         netdev->addr_assign_type = NET_ADDR_PERM;
727         set_addr(netdev->dev_addr, addr->b, addr_type);
728 }
729
730 static void ifup(struct net_device *netdev)
731 {
732         int err;
733
734         rtnl_lock();
735         err = dev_open(netdev);
736         if (err < 0)
737                 BT_INFO("iface %s cannot be opened (%d)", netdev->name, err);
738         rtnl_unlock();
739 }
740
741 static void ifdown(struct net_device *netdev)
742 {
743         int err;
744
745         rtnl_lock();
746         err = dev_close(netdev);
747         if (err < 0)
748                 BT_INFO("iface %s cannot be closed (%d)", netdev->name, err);
749         rtnl_unlock();
750 }
751
752 static void do_notify_peers(struct work_struct *work)
753 {
754         struct lowpan_dev *dev = container_of(work, struct lowpan_dev,
755                                               notify_peers.work);
756
757         netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */
758 }
759
760 static bool is_bt_6lowpan(struct hci_conn *hcon)
761 {
762         if (hcon->type != LE_LINK)
763                 return false;
764
765         if (!psm_6lowpan)
766                 return false;
767
768         return true;
769 }
770
771 static struct l2cap_chan *chan_create(void)
772 {
773         struct l2cap_chan *chan;
774
775         chan = l2cap_chan_create();
776         if (!chan)
777                 return NULL;
778
779         l2cap_chan_set_defaults(chan);
780
781         chan->chan_type = L2CAP_CHAN_CONN_ORIENTED;
782         chan->mode = L2CAP_MODE_LE_FLOWCTL;
783         chan->omtu = 65535;
784         chan->imtu = chan->omtu;
785
786         return chan;
787 }
788
789 static struct l2cap_chan *chan_open(struct l2cap_chan *pchan)
790 {
791         struct l2cap_chan *chan;
792
793         chan = chan_create();
794         if (!chan)
795                 return NULL;
796
797         chan->remote_mps = chan->omtu;
798         chan->mps = chan->omtu;
799
800         chan->state = BT_CONNECTED;
801
802         return chan;
803 }
804
805 static void set_ip_addr_bits(u8 addr_type, u8 *addr)
806 {
807         if (addr_type == BDADDR_LE_PUBLIC)
808                 *addr |= 0x02;
809         else
810                 *addr &= ~0x02;
811 }
812
813 static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan,
814                                         struct lowpan_dev *dev)
815 {
816         struct lowpan_peer *peer;
817
818         peer = kzalloc(sizeof(*peer), GFP_ATOMIC);
819         if (!peer)
820                 return NULL;
821
822         peer->chan = chan;
823         memset(&peer->peer_addr, 0, sizeof(struct in6_addr));
824
825         /* RFC 2464 ch. 5 */
826         peer->peer_addr.s6_addr[0] = 0xFE;
827         peer->peer_addr.s6_addr[1] = 0x80;
828         set_addr((u8 *)&peer->peer_addr.s6_addr + 8, chan->dst.b,
829                  chan->dst_type);
830
831         memcpy(&peer->eui64_addr, (u8 *)&peer->peer_addr.s6_addr + 8,
832                EUI64_ADDR_LEN);
833
834         /* IPv6 address needs to have the U/L bit set properly so toggle
835          * it back here.
836          */
837         set_ip_addr_bits(chan->dst_type, (u8 *)&peer->peer_addr.s6_addr + 8);
838
839         spin_lock(&devices_lock);
840         INIT_LIST_HEAD(&peer->list);
841         peer_add(dev, peer);
842         spin_unlock(&devices_lock);
843
844         /* Notifying peers about us needs to be done without locks held */
845         INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers);
846         schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100));
847
848         return peer->chan;
849 }
850
851 static int setup_netdev(struct l2cap_chan *chan, struct lowpan_dev **dev)
852 {
853         struct net_device *netdev;
854         int err = 0;
855
856         netdev = alloc_netdev(sizeof(struct lowpan_dev), IFACE_NAME_TEMPLATE,
857                               NET_NAME_UNKNOWN, netdev_setup);
858         if (!netdev)
859                 return -ENOMEM;
860
861         set_dev_addr(netdev, &chan->src, chan->src_type);
862
863         netdev->netdev_ops = &netdev_ops;
864         SET_NETDEV_DEV(netdev, &chan->conn->hcon->dev);
865         SET_NETDEV_DEVTYPE(netdev, &bt_type);
866
867         err = register_netdev(netdev);
868         if (err < 0) {
869                 BT_INFO("register_netdev failed %d", err);
870                 free_netdev(netdev);
871                 goto out;
872         }
873
874         BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d",
875                netdev->ifindex, &chan->dst, chan->dst_type,
876                &chan->src, chan->src_type);
877         set_bit(__LINK_STATE_PRESENT, &netdev->state);
878
879         *dev = netdev_priv(netdev);
880         (*dev)->netdev = netdev;
881         (*dev)->hdev = chan->conn->hcon->hdev;
882         INIT_LIST_HEAD(&(*dev)->peers);
883
884         spin_lock(&devices_lock);
885         INIT_LIST_HEAD(&(*dev)->list);
886         list_add_rcu(&(*dev)->list, &bt_6lowpan_devices);
887         spin_unlock(&devices_lock);
888
889         return 0;
890
891 out:
892         return err;
893 }
894
895 static inline void chan_ready_cb(struct l2cap_chan *chan)
896 {
897         struct lowpan_dev *dev;
898
899         dev = lookup_dev(chan->conn);
900
901         BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev);
902
903         if (!dev) {
904                 if (setup_netdev(chan, &dev) < 0) {
905                         l2cap_chan_del(chan, -ENOENT);
906                         return;
907                 }
908         }
909
910         if (!try_module_get(THIS_MODULE))
911                 return;
912
913         add_peer_chan(chan, dev);
914         ifup(dev->netdev);
915 }
916
917 static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan)
918 {
919         struct l2cap_chan *chan;
920
921         chan = chan_open(pchan);
922         chan->ops = pchan->ops;
923
924         BT_DBG("chan %p pchan %p", chan, pchan);
925
926         return chan;
927 }
928
929 static void delete_netdev(struct work_struct *work)
930 {
931         struct lowpan_dev *entry = container_of(work, struct lowpan_dev,
932                                                 delete_netdev);
933
934         unregister_netdev(entry->netdev);
935
936         /* The entry pointer is deleted in device_event() */
937 }
938
939 static void chan_close_cb(struct l2cap_chan *chan)
940 {
941         struct lowpan_dev *entry;
942         struct lowpan_dev *dev = NULL;
943         struct lowpan_peer *peer;
944         int err = -ENOENT;
945         bool last = false, removed = true;
946
947         BT_DBG("chan %p conn %p", chan, chan->conn);
948
949         if (chan->conn && chan->conn->hcon) {
950                 if (!is_bt_6lowpan(chan->conn->hcon))
951                         return;
952
953                 /* If conn is set, then the netdev is also there and we should
954                  * not remove it.
955                  */
956                 removed = false;
957         }
958
959         spin_lock(&devices_lock);
960
961         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
962                 dev = lowpan_dev(entry->netdev);
963                 peer = __peer_lookup_chan(dev, chan);
964                 if (peer) {
965                         last = peer_del(dev, peer);
966                         err = 0;
967
968                         BT_DBG("dev %p removing %speer %p", dev,
969                                last ? "last " : "1 ", peer);
970                         BT_DBG("chan %p orig refcnt %d", chan,
971                                atomic_read(&chan->kref.refcount));
972
973                         l2cap_chan_put(chan);
974                         break;
975                 }
976         }
977
978         if (!err && last && dev && !atomic_read(&dev->peer_count)) {
979                 spin_unlock(&devices_lock);
980
981                 cancel_delayed_work_sync(&dev->notify_peers);
982
983                 ifdown(dev->netdev);
984
985                 if (!removed) {
986                         INIT_WORK(&entry->delete_netdev, delete_netdev);
987                         schedule_work(&entry->delete_netdev);
988                 }
989         } else {
990                 spin_unlock(&devices_lock);
991         }
992
993         return;
994 }
995
996 static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err)
997 {
998         BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn,
999                state_to_string(state), err);
1000 }
1001
1002 static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan,
1003                                          unsigned long hdr_len,
1004                                          unsigned long len, int nb)
1005 {
1006         /* Note that we must allocate using GFP_ATOMIC here as
1007          * this function is called originally from netdev hard xmit
1008          * function in atomic context.
1009          */
1010         return bt_skb_alloc(hdr_len + len, GFP_ATOMIC);
1011 }
1012
1013 static void chan_suspend_cb(struct l2cap_chan *chan)
1014 {
1015         struct sk_buff *skb = chan->data;
1016
1017         BT_DBG("chan %p conn %p skb %p", chan, chan->conn, skb);
1018
1019         if (!skb)
1020                 return;
1021
1022         lowpan_cb(skb)->status = -EAGAIN;
1023 }
1024
1025 static void chan_resume_cb(struct l2cap_chan *chan)
1026 {
1027         struct sk_buff *skb = chan->data;
1028
1029         BT_DBG("chan %p conn %p skb %p", chan, chan->conn, skb);
1030
1031         if (!skb)
1032                 return;
1033
1034         lowpan_cb(skb)->status = 0;
1035 }
1036
1037 static long chan_get_sndtimeo_cb(struct l2cap_chan *chan)
1038 {
1039         return L2CAP_CONN_TIMEOUT;
1040 }
1041
1042 static const struct l2cap_ops bt_6lowpan_chan_ops = {
1043         .name                   = "L2CAP 6LoWPAN channel",
1044         .new_connection         = chan_new_conn_cb,
1045         .recv                   = chan_recv_cb,
1046         .close                  = chan_close_cb,
1047         .state_change           = chan_state_change_cb,
1048         .ready                  = chan_ready_cb,
1049         .resume                 = chan_resume_cb,
1050         .suspend                = chan_suspend_cb,
1051         .get_sndtimeo           = chan_get_sndtimeo_cb,
1052         .alloc_skb              = chan_alloc_skb_cb,
1053
1054         .teardown               = l2cap_chan_no_teardown,
1055         .defer                  = l2cap_chan_no_defer,
1056         .set_shutdown           = l2cap_chan_no_set_shutdown,
1057 };
1058
1059 static inline __u8 bdaddr_type(__u8 type)
1060 {
1061         if (type == ADDR_LE_DEV_PUBLIC)
1062                 return BDADDR_LE_PUBLIC;
1063         else
1064                 return BDADDR_LE_RANDOM;
1065 }
1066
1067 static struct l2cap_chan *chan_get(void)
1068 {
1069         struct l2cap_chan *pchan;
1070
1071         pchan = chan_create();
1072         if (!pchan)
1073                 return NULL;
1074
1075         pchan->ops = &bt_6lowpan_chan_ops;
1076
1077         return pchan;
1078 }
1079
1080 static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type)
1081 {
1082         struct l2cap_chan *pchan;
1083         int err;
1084
1085         pchan = chan_get();
1086         if (!pchan)
1087                 return -EINVAL;
1088
1089         err = l2cap_chan_connect(pchan, cpu_to_le16(psm_6lowpan), 0,
1090                                  addr, dst_type);
1091
1092         BT_DBG("chan %p err %d", pchan, err);
1093         if (err < 0)
1094                 l2cap_chan_put(pchan);
1095
1096         return err;
1097 }
1098
1099 static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type)
1100 {
1101         struct lowpan_peer *peer;
1102
1103         BT_DBG("conn %p dst type %d", conn, dst_type);
1104
1105         peer = lookup_peer(conn);
1106         if (!peer)
1107                 return -ENOENT;
1108
1109         BT_DBG("peer %p chan %p", peer, peer->chan);
1110
1111         l2cap_chan_close(peer->chan, ENOENT);
1112
1113         return 0;
1114 }
1115
1116 static struct l2cap_chan *bt_6lowpan_listen(void)
1117 {
1118         bdaddr_t *addr = BDADDR_ANY;
1119         struct l2cap_chan *pchan;
1120         int err;
1121
1122         if (psm_6lowpan == 0)
1123                 return NULL;
1124
1125         pchan = chan_get();
1126         if (!pchan)
1127                 return NULL;
1128
1129         pchan->state = BT_LISTEN;
1130         pchan->src_type = BDADDR_LE_PUBLIC;
1131
1132         atomic_set(&pchan->nesting, L2CAP_NESTING_PARENT);
1133
1134         BT_DBG("psm 0x%04x chan %p src type %d", psm_6lowpan, pchan,
1135                pchan->src_type);
1136
1137         err = l2cap_add_psm(pchan, addr, cpu_to_le16(psm_6lowpan));
1138         if (err) {
1139                 l2cap_chan_put(pchan);
1140                 BT_ERR("psm cannot be added err %d", err);
1141                 return NULL;
1142         }
1143
1144         return pchan;
1145 }
1146
1147 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type,
1148                           struct l2cap_conn **conn)
1149 {
1150         struct hci_conn *hcon;
1151         struct hci_dev *hdev;
1152         bdaddr_t *src = BDADDR_ANY;
1153         int n;
1154
1155         n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu",
1156                    &addr->b[5], &addr->b[4], &addr->b[3],
1157                    &addr->b[2], &addr->b[1], &addr->b[0],
1158                    addr_type);
1159
1160         if (n < 7)
1161                 return -EINVAL;
1162
1163         hdev = hci_get_route(addr, src);
1164         if (!hdev)
1165                 return -ENOENT;
1166
1167         hci_dev_lock(hdev);
1168         hcon = hci_conn_hash_lookup_ba(hdev, LE_LINK, addr);
1169         hci_dev_unlock(hdev);
1170
1171         if (!hcon)
1172                 return -ENOENT;
1173
1174         *conn = (struct l2cap_conn *)hcon->l2cap_data;
1175
1176         BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type);
1177
1178         return 0;
1179 }
1180
1181 static void disconnect_all_peers(void)
1182 {
1183         struct lowpan_dev *entry;
1184         struct lowpan_peer *peer, *tmp_peer, *new_peer;
1185         struct list_head peers;
1186
1187         INIT_LIST_HEAD(&peers);
1188
1189         /* We make a separate list of peers as the close_cb() will
1190          * modify the device peers list so it is better not to mess
1191          * with the same list at the same time.
1192          */
1193
1194         rcu_read_lock();
1195
1196         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1197                 list_for_each_entry_rcu(peer, &entry->peers, list) {
1198                         new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC);
1199                         if (!new_peer)
1200                                 break;
1201
1202                         new_peer->chan = peer->chan;
1203                         INIT_LIST_HEAD(&new_peer->list);
1204
1205                         list_add(&new_peer->list, &peers);
1206                 }
1207         }
1208
1209         rcu_read_unlock();
1210
1211         spin_lock(&devices_lock);
1212         list_for_each_entry_safe(peer, tmp_peer, &peers, list) {
1213                 l2cap_chan_close(peer->chan, ENOENT);
1214
1215                 list_del_rcu(&peer->list);
1216                 kfree_rcu(peer, rcu);
1217
1218                 module_put(THIS_MODULE);
1219         }
1220         spin_unlock(&devices_lock);
1221 }
1222
1223 struct set_psm {
1224         struct work_struct work;
1225         u16 psm;
1226 };
1227
1228 static void do_psm_set(struct work_struct *work)
1229 {
1230         struct set_psm *set_psm = container_of(work, struct set_psm, work);
1231
1232         if (set_psm->psm == 0 || psm_6lowpan != set_psm->psm)
1233                 /* Disconnect existing connections if 6lowpan is
1234                  * disabled (psm = 0), or if psm changes.
1235                  */
1236                 disconnect_all_peers();
1237
1238         psm_6lowpan = set_psm->psm;
1239
1240         if (listen_chan) {
1241                 l2cap_chan_close(listen_chan, 0);
1242                 l2cap_chan_put(listen_chan);
1243         }
1244
1245         listen_chan = bt_6lowpan_listen();
1246
1247         kfree(set_psm);
1248 }
1249
1250 static int lowpan_psm_set(void *data, u64 val)
1251 {
1252         struct set_psm *set_psm;
1253
1254         set_psm = kzalloc(sizeof(*set_psm), GFP_KERNEL);
1255         if (!set_psm)
1256                 return -ENOMEM;
1257
1258         set_psm->psm = val;
1259         INIT_WORK(&set_psm->work, do_psm_set);
1260
1261         schedule_work(&set_psm->work);
1262
1263         return 0;
1264 }
1265
1266 static int lowpan_psm_get(void *data, u64 *val)
1267 {
1268         *val = psm_6lowpan;
1269         return 0;
1270 }
1271
1272 DEFINE_SIMPLE_ATTRIBUTE(lowpan_psm_fops, lowpan_psm_get,
1273                         lowpan_psm_set, "%llu\n");
1274
1275 static ssize_t lowpan_control_write(struct file *fp,
1276                                     const char __user *user_buffer,
1277                                     size_t count,
1278                                     loff_t *position)
1279 {
1280         char buf[32];
1281         size_t buf_size = min(count, sizeof(buf) - 1);
1282         int ret;
1283         bdaddr_t addr;
1284         u8 addr_type;
1285         struct l2cap_conn *conn = NULL;
1286
1287         if (copy_from_user(buf, user_buffer, buf_size))
1288                 return -EFAULT;
1289
1290         buf[buf_size] = '\0';
1291
1292         if (memcmp(buf, "connect ", 8) == 0) {
1293                 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn);
1294                 if (ret == -EINVAL)
1295                         return ret;
1296
1297                 if (listen_chan) {
1298                         l2cap_chan_close(listen_chan, 0);
1299                         l2cap_chan_put(listen_chan);
1300                         listen_chan = NULL;
1301                 }
1302
1303                 if (conn) {
1304                         struct lowpan_peer *peer;
1305
1306                         if (!is_bt_6lowpan(conn->hcon))
1307                                 return -EINVAL;
1308
1309                         peer = lookup_peer(conn);
1310                         if (peer) {
1311                                 BT_DBG("6LoWPAN connection already exists");
1312                                 return -EALREADY;
1313                         }
1314
1315                         BT_DBG("conn %p dst %pMR type %d user %d", conn,
1316                                &conn->hcon->dst, conn->hcon->dst_type,
1317                                addr_type);
1318                 }
1319
1320                 ret = bt_6lowpan_connect(&addr, addr_type);
1321                 if (ret < 0)
1322                         return ret;
1323
1324                 return count;
1325         }
1326
1327         if (memcmp(buf, "disconnect ", 11) == 0) {
1328                 ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn);
1329                 if (ret < 0)
1330                         return ret;
1331
1332                 ret = bt_6lowpan_disconnect(conn, addr_type);
1333                 if (ret < 0)
1334                         return ret;
1335
1336                 return count;
1337         }
1338
1339         return count;
1340 }
1341
1342 static int lowpan_control_show(struct seq_file *f, void *ptr)
1343 {
1344         struct lowpan_dev *entry;
1345         struct lowpan_peer *peer;
1346
1347         spin_lock(&devices_lock);
1348
1349         list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1350                 list_for_each_entry(peer, &entry->peers, list)
1351                         seq_printf(f, "%pMR (type %u)\n",
1352                                    &peer->chan->dst, peer->chan->dst_type);
1353         }
1354
1355         spin_unlock(&devices_lock);
1356
1357         return 0;
1358 }
1359
1360 static int lowpan_control_open(struct inode *inode, struct file *file)
1361 {
1362         return single_open(file, lowpan_control_show, inode->i_private);
1363 }
1364
1365 static const struct file_operations lowpan_control_fops = {
1366         .open           = lowpan_control_open,
1367         .read           = seq_read,
1368         .write          = lowpan_control_write,
1369         .llseek         = seq_lseek,
1370         .release        = single_release,
1371 };
1372
1373 static void disconnect_devices(void)
1374 {
1375         struct lowpan_dev *entry, *tmp, *new_dev;
1376         struct list_head devices;
1377
1378         INIT_LIST_HEAD(&devices);
1379
1380         /* We make a separate list of devices because the unregister_netdev()
1381          * will call device_event() which will also want to modify the same
1382          * devices list.
1383          */
1384
1385         rcu_read_lock();
1386
1387         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1388                 new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC);
1389                 if (!new_dev)
1390                         break;
1391
1392                 new_dev->netdev = entry->netdev;
1393                 INIT_LIST_HEAD(&new_dev->list);
1394
1395                 list_add_rcu(&new_dev->list, &devices);
1396         }
1397
1398         rcu_read_unlock();
1399
1400         list_for_each_entry_safe(entry, tmp, &devices, list) {
1401                 ifdown(entry->netdev);
1402                 BT_DBG("Unregistering netdev %s %p",
1403                        entry->netdev->name, entry->netdev);
1404                 unregister_netdev(entry->netdev);
1405                 kfree(entry);
1406         }
1407 }
1408
1409 static int device_event(struct notifier_block *unused,
1410                         unsigned long event, void *ptr)
1411 {
1412         struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
1413         struct lowpan_dev *entry;
1414
1415         if (netdev->type != ARPHRD_6LOWPAN)
1416                 return NOTIFY_DONE;
1417
1418         switch (event) {
1419         case NETDEV_UNREGISTER:
1420                 spin_lock(&devices_lock);
1421                 list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1422                         if (entry->netdev == netdev) {
1423                                 BT_DBG("Unregistered netdev %s %p",
1424                                        netdev->name, netdev);
1425                                 list_del(&entry->list);
1426                                 kfree(entry);
1427                                 break;
1428                         }
1429                 }
1430                 spin_unlock(&devices_lock);
1431                 break;
1432         }
1433
1434         return NOTIFY_DONE;
1435 }
1436
1437 static struct notifier_block bt_6lowpan_dev_notifier = {
1438         .notifier_call = device_event,
1439 };
1440
1441 static int __init bt_6lowpan_init(void)
1442 {
1443         lowpan_psm_debugfs = debugfs_create_file("6lowpan_psm", 0644,
1444                                                  bt_debugfs, NULL,
1445                                                  &lowpan_psm_fops);
1446         lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644,
1447                                                      bt_debugfs, NULL,
1448                                                      &lowpan_control_fops);
1449
1450         return register_netdevice_notifier(&bt_6lowpan_dev_notifier);
1451 }
1452
1453 static void __exit bt_6lowpan_exit(void)
1454 {
1455         debugfs_remove(lowpan_psm_debugfs);
1456         debugfs_remove(lowpan_control_debugfs);
1457
1458         if (listen_chan) {
1459                 l2cap_chan_close(listen_chan, 0);
1460                 l2cap_chan_put(listen_chan);
1461         }
1462
1463         disconnect_devices();
1464
1465         unregister_netdevice_notifier(&bt_6lowpan_dev_notifier);
1466 }
1467
1468 module_init(bt_6lowpan_init);
1469 module_exit(bt_6lowpan_exit);
1470
1471 MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>");
1472 MODULE_DESCRIPTION("Bluetooth 6LoWPAN");
1473 MODULE_VERSION(VERSION);
1474 MODULE_LICENSE("GPL");