Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / 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_enable_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 static bool enable_6lowpan;
59
60 /* We are listening incoming connections via this channel
61  */
62 static struct l2cap_chan *listen_chan;
63
64 struct lowpan_peer {
65         struct list_head list;
66         struct rcu_head rcu;
67         struct l2cap_chan *chan;
68
69         /* peer addresses in various formats */
70         unsigned char eui64_addr[EUI64_ADDR_LEN];
71         struct in6_addr peer_addr;
72 };
73
74 struct lowpan_dev {
75         struct list_head list;
76
77         struct hci_dev *hdev;
78         struct net_device *netdev;
79         struct list_head peers;
80         atomic_t peer_count; /* number of items in peers list */
81
82         struct work_struct delete_netdev;
83         struct delayed_work notify_peers;
84 };
85
86 static inline struct lowpan_dev *lowpan_dev(const struct net_device *netdev)
87 {
88         return netdev_priv(netdev);
89 }
90
91 static inline void peer_add(struct lowpan_dev *dev, 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_dev *dev, struct lowpan_peer *peer)
98 {
99         list_del_rcu(&peer->list);
100         kfree_rcu(peer, rcu);
101
102         module_put(THIS_MODULE);
103
104         if (atomic_dec_and_test(&dev->peer_count)) {
105                 BT_DBG("last peer");
106                 return true;
107         }
108
109         return false;
110 }
111
112 static inline struct lowpan_peer *peer_lookup_ba(struct lowpan_dev *dev,
113                                                  bdaddr_t *ba, __u8 type)
114 {
115         struct lowpan_peer *peer;
116
117         BT_DBG("peers %d addr %pMR type %d", atomic_read(&dev->peer_count),
118                ba, type);
119
120         rcu_read_lock();
121
122         list_for_each_entry_rcu(peer, &dev->peers, list) {
123                 BT_DBG("dst addr %pMR dst type %d",
124                        &peer->chan->dst, peer->chan->dst_type);
125
126                 if (bacmp(&peer->chan->dst, ba))
127                         continue;
128
129                 if (type == peer->chan->dst_type) {
130                         rcu_read_unlock();
131                         return peer;
132                 }
133         }
134
135         rcu_read_unlock();
136
137         return NULL;
138 }
139
140 static inline struct lowpan_peer *__peer_lookup_chan(struct lowpan_dev *dev,
141                                                      struct l2cap_chan *chan)
142 {
143         struct lowpan_peer *peer;
144
145         list_for_each_entry_rcu(peer, &dev->peers, list) {
146                 if (peer->chan == chan)
147                         return peer;
148         }
149
150         return NULL;
151 }
152
153 static inline struct lowpan_peer *__peer_lookup_conn(struct lowpan_dev *dev,
154                                                      struct l2cap_conn *conn)
155 {
156         struct lowpan_peer *peer;
157
158         list_for_each_entry_rcu(peer, &dev->peers, list) {
159                 if (peer->chan->conn == conn)
160                         return peer;
161         }
162
163         return NULL;
164 }
165
166 static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_dev *dev,
167                                                   struct in6_addr *daddr,
168                                                   struct sk_buff *skb)
169 {
170         struct lowpan_peer *peer;
171         struct in6_addr *nexthop;
172         struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
173         int count = atomic_read(&dev->peer_count);
174
175         BT_DBG("peers %d addr %pI6c rt %p", count, daddr, rt);
176
177         /* If we have multiple 6lowpan peers, then check where we should
178          * send the packet. If only one peer exists, then we can send the
179          * packet right away.
180          */
181         if (count == 1) {
182                 rcu_read_lock();
183                 peer = list_first_or_null_rcu(&dev->peers, struct lowpan_peer,
184                                               list);
185                 rcu_read_unlock();
186                 return peer;
187         }
188
189         if (!rt) {
190                 nexthop = &lowpan_cb(skb)->gw;
191
192                 if (ipv6_addr_any(nexthop))
193                         return NULL;
194         } else {
195                 nexthop = rt6_nexthop(rt);
196
197                 /* We need to remember the address because it is needed
198                  * by bt_xmit() when sending the packet. In bt_xmit(), the
199                  * destination routing info is not set.
200                  */
201                 memcpy(&lowpan_cb(skb)->gw, nexthop, sizeof(struct in6_addr));
202         }
203
204         BT_DBG("gw %pI6c", nexthop);
205
206         rcu_read_lock();
207
208         list_for_each_entry_rcu(peer, &dev->peers, list) {
209                 BT_DBG("dst addr %pMR dst type %d ip %pI6c",
210                        &peer->chan->dst, peer->chan->dst_type,
211                        &peer->peer_addr);
212
213                 if (!ipv6_addr_cmp(&peer->peer_addr, nexthop)) {
214                         rcu_read_unlock();
215                         return peer;
216                 }
217         }
218
219         rcu_read_unlock();
220
221         return NULL;
222 }
223
224 static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn)
225 {
226         struct lowpan_dev *entry;
227         struct lowpan_peer *peer = NULL;
228
229         rcu_read_lock();
230
231         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
232                 peer = __peer_lookup_conn(entry, conn);
233                 if (peer)
234                         break;
235         }
236
237         rcu_read_unlock();
238
239         return peer;
240 }
241
242 static struct lowpan_dev *lookup_dev(struct l2cap_conn *conn)
243 {
244         struct lowpan_dev *entry;
245         struct lowpan_dev *dev = NULL;
246
247         rcu_read_lock();
248
249         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
250                 if (conn->hcon->hdev == entry->hdev) {
251                         dev = entry;
252                         break;
253                 }
254         }
255
256         rcu_read_unlock();
257
258         return dev;
259 }
260
261 static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev)
262 {
263         struct sk_buff *skb_cp;
264
265         skb_cp = skb_copy(skb, GFP_ATOMIC);
266         if (!skb_cp)
267                 return NET_RX_DROP;
268
269         return netif_rx(skb_cp);
270 }
271
272 static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev,
273                            struct l2cap_chan *chan)
274 {
275         const u8 *saddr, *daddr;
276         u8 iphc0, iphc1;
277         struct lowpan_dev *dev;
278         struct lowpan_peer *peer;
279
280         dev = lowpan_dev(netdev);
281
282         rcu_read_lock();
283         peer = __peer_lookup_chan(dev, chan);
284         rcu_read_unlock();
285         if (!peer)
286                 return -EINVAL;
287
288         saddr = peer->eui64_addr;
289         daddr = dev->netdev->dev_addr;
290
291         /* at least two bytes will be used for the encoding */
292         if (skb->len < 2)
293                 return -EINVAL;
294
295         if (lowpan_fetch_skb_u8(skb, &iphc0))
296                 return -EINVAL;
297
298         if (lowpan_fetch_skb_u8(skb, &iphc1))
299                 return -EINVAL;
300
301         return lowpan_header_decompress(skb, netdev,
302                                         saddr, IEEE802154_ADDR_LONG,
303                                         EUI64_ADDR_LEN, daddr,
304                                         IEEE802154_ADDR_LONG, EUI64_ADDR_LEN,
305                                         iphc0, iphc1);
306
307 }
308
309 static int recv_pkt(struct sk_buff *skb, struct net_device *dev,
310                     struct l2cap_chan *chan)
311 {
312         struct sk_buff *local_skb;
313         int ret;
314
315         if (!netif_running(dev))
316                 goto drop;
317
318         if (dev->type != ARPHRD_6LOWPAN)
319                 goto drop;
320
321         skb = skb_share_check(skb, GFP_ATOMIC);
322         if (!skb)
323                 goto drop;
324
325         /* check that it's our buffer */
326         if (skb->data[0] == LOWPAN_DISPATCH_IPV6) {
327                 /* Copy the packet so that the IPv6 header is
328                  * properly aligned.
329                  */
330                 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
331                                             skb_tailroom(skb), GFP_ATOMIC);
332                 if (!local_skb)
333                         goto drop;
334
335                 local_skb->protocol = htons(ETH_P_IPV6);
336                 local_skb->pkt_type = PACKET_HOST;
337
338                 skb_reset_network_header(local_skb);
339                 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
340
341                 if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) {
342                         kfree_skb(local_skb);
343                         goto drop;
344                 }
345
346                 dev->stats.rx_bytes += skb->len;
347                 dev->stats.rx_packets++;
348
349                 consume_skb(local_skb);
350                 consume_skb(skb);
351         } else {
352                 switch (skb->data[0] & 0xe0) {
353                 case LOWPAN_DISPATCH_IPHC:      /* ipv6 datagram */
354                         local_skb = skb_clone(skb, GFP_ATOMIC);
355                         if (!local_skb)
356                                 goto drop;
357
358                         ret = iphc_decompress(local_skb, dev, chan);
359                         if (ret < 0) {
360                                 kfree_skb(local_skb);
361                                 goto drop;
362                         }
363
364                         local_skb->protocol = htons(ETH_P_IPV6);
365                         local_skb->pkt_type = PACKET_HOST;
366                         local_skb->dev = dev;
367
368                         if (give_skb_to_upper(local_skb, dev)
369                                         != NET_RX_SUCCESS) {
370                                 kfree_skb(local_skb);
371                                 goto drop;
372                         }
373
374                         dev->stats.rx_bytes += skb->len;
375                         dev->stats.rx_packets++;
376
377                         consume_skb(local_skb);
378                         consume_skb(skb);
379                         break;
380                 default:
381                         break;
382                 }
383         }
384
385         return NET_RX_SUCCESS;
386
387 drop:
388         dev->stats.rx_dropped++;
389         return NET_RX_DROP;
390 }
391
392 /* Packet from BT LE device */
393 static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
394 {
395         struct lowpan_dev *dev;
396         struct lowpan_peer *peer;
397         int err;
398
399         peer = lookup_peer(chan->conn);
400         if (!peer)
401                 return -ENOENT;
402
403         dev = lookup_dev(chan->conn);
404         if (!dev || !dev->netdev)
405                 return -ENOENT;
406
407         err = recv_pkt(skb, dev->netdev, chan);
408         if (err) {
409                 BT_DBG("recv pkt %d", err);
410                 err = -EAGAIN;
411         }
412
413         return err;
414 }
415
416 static u8 get_addr_type_from_eui64(u8 byte)
417 {
418         /* Is universal(0) or local(1) bit */
419         return ((byte & 0x02) ? BDADDR_LE_RANDOM : BDADDR_LE_PUBLIC);
420 }
421
422 static void copy_to_bdaddr(struct in6_addr *ip6_daddr, bdaddr_t *addr)
423 {
424         u8 *eui64 = ip6_daddr->s6_addr + 8;
425
426         addr->b[0] = eui64[7];
427         addr->b[1] = eui64[6];
428         addr->b[2] = eui64[5];
429         addr->b[3] = eui64[2];
430         addr->b[4] = eui64[1];
431         addr->b[5] = eui64[0];
432 }
433
434 static void convert_dest_bdaddr(struct in6_addr *ip6_daddr,
435                                 bdaddr_t *addr, u8 *addr_type)
436 {
437         copy_to_bdaddr(ip6_daddr, addr);
438
439         /* We need to toggle the U/L bit that we got from IPv6 address
440          * so that we get the proper address and type of the BD address.
441          */
442         addr->b[5] ^= 0x02;
443
444         *addr_type = get_addr_type_from_eui64(addr->b[5]);
445 }
446
447 static int setup_header(struct sk_buff *skb, struct net_device *netdev,
448                         bdaddr_t *peer_addr, u8 *peer_addr_type)
449 {
450         struct in6_addr ipv6_daddr;
451         struct lowpan_dev *dev;
452         struct lowpan_peer *peer;
453         bdaddr_t addr, *any = BDADDR_ANY;
454         u8 *daddr = any->b;
455         int err, status = 0;
456
457         dev = lowpan_dev(netdev);
458
459         memcpy(&ipv6_daddr, &lowpan_cb(skb)->addr, sizeof(ipv6_daddr));
460
461         if (ipv6_addr_is_multicast(&ipv6_daddr)) {
462                 lowpan_cb(skb)->chan = NULL;
463         } else {
464                 u8 addr_type;
465
466                 /* Get destination BT device from skb.
467                  * If there is no such peer then discard the packet.
468                  */
469                 convert_dest_bdaddr(&ipv6_daddr, &addr, &addr_type);
470
471                 BT_DBG("dest addr %pMR type %d IP %pI6c", &addr,
472                        addr_type, &ipv6_daddr);
473
474                 peer = peer_lookup_ba(dev, &addr, addr_type);
475                 if (!peer) {
476                         /* The packet might be sent to 6lowpan interface
477                          * because of routing (either via default route
478                          * or user set route) so get peer according to
479                          * the destination address.
480                          */
481                         peer = peer_lookup_dst(dev, &ipv6_daddr, skb);
482                         if (!peer) {
483                                 BT_DBG("no such peer %pMR found", &addr);
484                                 return -ENOENT;
485                         }
486                 }
487
488                 daddr = peer->eui64_addr;
489                 *peer_addr = addr;
490                 *peer_addr_type = addr_type;
491                 lowpan_cb(skb)->chan = peer->chan;
492
493                 status = 1;
494         }
495
496         lowpan_header_compress(skb, netdev, ETH_P_IPV6, daddr,
497                                dev->netdev->dev_addr, skb->len);
498
499         err = dev_hard_header(skb, netdev, ETH_P_IPV6, NULL, NULL, 0);
500         if (err < 0)
501                 return err;
502
503         return status;
504 }
505
506 static int header_create(struct sk_buff *skb, struct net_device *netdev,
507                          unsigned short type, const void *_daddr,
508                          const void *_saddr, unsigned int len)
509 {
510         struct ipv6hdr *hdr;
511
512         if (type != ETH_P_IPV6)
513                 return -EINVAL;
514
515         hdr = ipv6_hdr(skb);
516
517         memcpy(&lowpan_cb(skb)->addr, &hdr->daddr, sizeof(struct in6_addr));
518
519         return 0;
520 }
521
522 /* Packet to BT LE device */
523 static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb,
524                     struct net_device *netdev)
525 {
526         struct msghdr msg;
527         struct kvec iv;
528         int err;
529
530         /* Remember the skb so that we can send EAGAIN to the caller if
531          * we run out of credits.
532          */
533         chan->data = skb;
534
535         iv.iov_base = skb->data;
536         iv.iov_len = skb->len;
537
538         memset(&msg, 0, sizeof(msg));
539         iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, &iv, 1, skb->len);
540
541         err = l2cap_chan_send(chan, &msg, skb->len);
542         if (err > 0) {
543                 netdev->stats.tx_bytes += err;
544                 netdev->stats.tx_packets++;
545                 return 0;
546         }
547
548         if (!err)
549                 err = lowpan_cb(skb)->status;
550
551         if (err < 0) {
552                 if (err == -EAGAIN)
553                         netdev->stats.tx_dropped++;
554                 else
555                         netdev->stats.tx_errors++;
556         }
557
558         return err;
559 }
560
561 static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev)
562 {
563         struct sk_buff *local_skb;
564         struct lowpan_dev *entry;
565         int err = 0;
566
567         rcu_read_lock();
568
569         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
570                 struct lowpan_peer *pentry;
571                 struct lowpan_dev *dev;
572
573                 if (entry->netdev != netdev)
574                         continue;
575
576                 dev = lowpan_dev(entry->netdev);
577
578                 list_for_each_entry_rcu(pentry, &dev->peers, list) {
579                         int ret;
580
581                         local_skb = skb_clone(skb, GFP_ATOMIC);
582
583                         BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
584                                netdev->name,
585                                &pentry->chan->dst, pentry->chan->dst_type,
586                                &pentry->peer_addr, pentry->chan);
587                         ret = send_pkt(pentry->chan, local_skb, netdev);
588                         if (ret < 0)
589                                 err = ret;
590
591                         kfree_skb(local_skb);
592                 }
593         }
594
595         rcu_read_unlock();
596
597         return err;
598 }
599
600 static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev)
601 {
602         int err = 0;
603         bdaddr_t addr;
604         u8 addr_type;
605
606         /* We must take a copy of the skb before we modify/replace the ipv6
607          * header as the header could be used elsewhere
608          */
609         skb = skb_unshare(skb, GFP_ATOMIC);
610         if (!skb)
611                 return NET_XMIT_DROP;
612
613         /* Return values from setup_header()
614          *  <0 - error, packet is dropped
615          *   0 - this is a multicast packet
616          *   1 - this is unicast packet
617          */
618         err = setup_header(skb, netdev, &addr, &addr_type);
619         if (err < 0) {
620                 kfree_skb(skb);
621                 return NET_XMIT_DROP;
622         }
623
624         if (err) {
625                 if (lowpan_cb(skb)->chan) {
626                         BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
627                                netdev->name, &addr, addr_type,
628                                &lowpan_cb(skb)->addr, lowpan_cb(skb)->chan);
629                         err = send_pkt(lowpan_cb(skb)->chan, skb, netdev);
630                 } else {
631                         err = -ENOENT;
632                 }
633         } else {
634                 /* We need to send the packet to every device behind this
635                  * interface.
636                  */
637                 err = send_mcast_pkt(skb, netdev);
638         }
639
640         dev_kfree_skb(skb);
641
642         if (err)
643                 BT_DBG("ERROR: xmit failed (%d)", err);
644
645         return err < 0 ? NET_XMIT_DROP : err;
646 }
647
648 static struct lock_class_key bt_tx_busylock;
649 static struct lock_class_key bt_netdev_xmit_lock_key;
650
651 static void bt_set_lockdep_class_one(struct net_device *dev,
652                                      struct netdev_queue *txq,
653                                      void *_unused)
654 {
655         lockdep_set_class(&txq->_xmit_lock, &bt_netdev_xmit_lock_key);
656 }
657
658 static int bt_dev_init(struct net_device *dev)
659 {
660         netdev_for_each_tx_queue(dev, bt_set_lockdep_class_one, NULL);
661         dev->qdisc_tx_busylock = &bt_tx_busylock;
662
663         return 0;
664 }
665
666 static const struct net_device_ops netdev_ops = {
667         .ndo_init               = bt_dev_init,
668         .ndo_start_xmit         = bt_xmit,
669 };
670
671 static struct header_ops header_ops = {
672         .create = header_create,
673 };
674
675 static void netdev_setup(struct net_device *dev)
676 {
677         dev->addr_len           = EUI64_ADDR_LEN;
678         dev->type               = ARPHRD_6LOWPAN;
679
680         dev->hard_header_len    = 0;
681         dev->needed_tailroom    = 0;
682         dev->mtu                = IPV6_MIN_MTU;
683         dev->tx_queue_len       = 0;
684         dev->flags              = IFF_RUNNING | IFF_POINTOPOINT |
685                                   IFF_MULTICAST;
686         dev->watchdog_timeo     = 0;
687
688         dev->netdev_ops         = &netdev_ops;
689         dev->header_ops         = &header_ops;
690         dev->destructor         = free_netdev;
691 }
692
693 static struct device_type bt_type = {
694         .name   = "bluetooth",
695 };
696
697 static void set_addr(u8 *eui, u8 *addr, u8 addr_type)
698 {
699         /* addr is the BT address in little-endian format */
700         eui[0] = addr[5];
701         eui[1] = addr[4];
702         eui[2] = addr[3];
703         eui[3] = 0xFF;
704         eui[4] = 0xFE;
705         eui[5] = addr[2];
706         eui[6] = addr[1];
707         eui[7] = addr[0];
708
709         /* Universal/local bit set, BT 6lowpan draft ch. 3.2.1 */
710         if (addr_type == BDADDR_LE_PUBLIC)
711                 eui[0] &= ~0x02;
712         else
713                 eui[0] |= 0x02;
714
715         BT_DBG("type %d addr %*phC", addr_type, 8, eui);
716 }
717
718 static void set_dev_addr(struct net_device *netdev, bdaddr_t *addr,
719                          u8 addr_type)
720 {
721         netdev->addr_assign_type = NET_ADDR_PERM;
722         set_addr(netdev->dev_addr, addr->b, addr_type);
723 }
724
725 static void ifup(struct net_device *netdev)
726 {
727         int err;
728
729         rtnl_lock();
730         err = dev_open(netdev);
731         if (err < 0)
732                 BT_INFO("iface %s cannot be opened (%d)", netdev->name, err);
733         rtnl_unlock();
734 }
735
736 static void ifdown(struct net_device *netdev)
737 {
738         int err;
739
740         rtnl_lock();
741         err = dev_close(netdev);
742         if (err < 0)
743                 BT_INFO("iface %s cannot be closed (%d)", netdev->name, err);
744         rtnl_unlock();
745 }
746
747 static void do_notify_peers(struct work_struct *work)
748 {
749         struct lowpan_dev *dev = container_of(work, struct lowpan_dev,
750                                               notify_peers.work);
751
752         netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */
753 }
754
755 static bool is_bt_6lowpan(struct hci_conn *hcon)
756 {
757         if (hcon->type != LE_LINK)
758                 return false;
759
760         if (!enable_6lowpan)
761                 return false;
762
763         return true;
764 }
765
766 static struct l2cap_chan *chan_create(void)
767 {
768         struct l2cap_chan *chan;
769
770         chan = l2cap_chan_create();
771         if (!chan)
772                 return NULL;
773
774         l2cap_chan_set_defaults(chan);
775
776         chan->chan_type = L2CAP_CHAN_CONN_ORIENTED;
777         chan->mode = L2CAP_MODE_LE_FLOWCTL;
778         chan->omtu = 65535;
779         chan->imtu = chan->omtu;
780
781         return chan;
782 }
783
784 static struct l2cap_chan *chan_open(struct l2cap_chan *pchan)
785 {
786         struct l2cap_chan *chan;
787
788         chan = chan_create();
789         if (!chan)
790                 return NULL;
791
792         chan->remote_mps = chan->omtu;
793         chan->mps = chan->omtu;
794
795         chan->state = BT_CONNECTED;
796
797         return chan;
798 }
799
800 static void set_ip_addr_bits(u8 addr_type, u8 *addr)
801 {
802         if (addr_type == BDADDR_LE_PUBLIC)
803                 *addr |= 0x02;
804         else
805                 *addr &= ~0x02;
806 }
807
808 static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan,
809                                         struct lowpan_dev *dev)
810 {
811         struct lowpan_peer *peer;
812
813         peer = kzalloc(sizeof(*peer), GFP_ATOMIC);
814         if (!peer)
815                 return NULL;
816
817         peer->chan = chan;
818         memset(&peer->peer_addr, 0, sizeof(struct in6_addr));
819
820         /* RFC 2464 ch. 5 */
821         peer->peer_addr.s6_addr[0] = 0xFE;
822         peer->peer_addr.s6_addr[1] = 0x80;
823         set_addr((u8 *)&peer->peer_addr.s6_addr + 8, chan->dst.b,
824                  chan->dst_type);
825
826         memcpy(&peer->eui64_addr, (u8 *)&peer->peer_addr.s6_addr + 8,
827                EUI64_ADDR_LEN);
828
829         /* IPv6 address needs to have the U/L bit set properly so toggle
830          * it back here.
831          */
832         set_ip_addr_bits(chan->dst_type, (u8 *)&peer->peer_addr.s6_addr + 8);
833
834         spin_lock(&devices_lock);
835         INIT_LIST_HEAD(&peer->list);
836         peer_add(dev, peer);
837         spin_unlock(&devices_lock);
838
839         /* Notifying peers about us needs to be done without locks held */
840         INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers);
841         schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100));
842
843         return peer->chan;
844 }
845
846 static int setup_netdev(struct l2cap_chan *chan, struct lowpan_dev **dev)
847 {
848         struct net_device *netdev;
849         int err = 0;
850
851         netdev = alloc_netdev(sizeof(struct lowpan_dev), IFACE_NAME_TEMPLATE,
852                               NET_NAME_UNKNOWN, netdev_setup);
853         if (!netdev)
854                 return -ENOMEM;
855
856         set_dev_addr(netdev, &chan->src, chan->src_type);
857
858         netdev->netdev_ops = &netdev_ops;
859         SET_NETDEV_DEV(netdev, &chan->conn->hcon->dev);
860         SET_NETDEV_DEVTYPE(netdev, &bt_type);
861
862         err = register_netdev(netdev);
863         if (err < 0) {
864                 BT_INFO("register_netdev failed %d", err);
865                 free_netdev(netdev);
866                 goto out;
867         }
868
869         BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d",
870                netdev->ifindex, &chan->dst, chan->dst_type,
871                &chan->src, chan->src_type);
872         set_bit(__LINK_STATE_PRESENT, &netdev->state);
873
874         *dev = netdev_priv(netdev);
875         (*dev)->netdev = netdev;
876         (*dev)->hdev = chan->conn->hcon->hdev;
877         INIT_LIST_HEAD(&(*dev)->peers);
878
879         spin_lock(&devices_lock);
880         INIT_LIST_HEAD(&(*dev)->list);
881         list_add_rcu(&(*dev)->list, &bt_6lowpan_devices);
882         spin_unlock(&devices_lock);
883
884         return 0;
885
886 out:
887         return err;
888 }
889
890 static inline void chan_ready_cb(struct l2cap_chan *chan)
891 {
892         struct lowpan_dev *dev;
893
894         dev = lookup_dev(chan->conn);
895
896         BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev);
897
898         if (!dev) {
899                 if (setup_netdev(chan, &dev) < 0) {
900                         l2cap_chan_del(chan, -ENOENT);
901                         return;
902                 }
903         }
904
905         if (!try_module_get(THIS_MODULE))
906                 return;
907
908         add_peer_chan(chan, dev);
909         ifup(dev->netdev);
910 }
911
912 static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan)
913 {
914         struct l2cap_chan *chan;
915
916         chan = chan_open(pchan);
917         chan->ops = pchan->ops;
918
919         BT_DBG("chan %p pchan %p", chan, pchan);
920
921         return chan;
922 }
923
924 static void delete_netdev(struct work_struct *work)
925 {
926         struct lowpan_dev *entry = container_of(work, struct lowpan_dev,
927                                                 delete_netdev);
928
929         unregister_netdev(entry->netdev);
930
931         /* The entry pointer is deleted in device_event() */
932 }
933
934 static void chan_close_cb(struct l2cap_chan *chan)
935 {
936         struct lowpan_dev *entry;
937         struct lowpan_dev *dev = NULL;
938         struct lowpan_peer *peer;
939         int err = -ENOENT;
940         bool last = false, removed = true;
941
942         BT_DBG("chan %p conn %p", chan, chan->conn);
943
944         if (chan->conn && chan->conn->hcon) {
945                 if (!is_bt_6lowpan(chan->conn->hcon))
946                         return;
947
948                 /* If conn is set, then the netdev is also there and we should
949                  * not remove it.
950                  */
951                 removed = false;
952         }
953
954         spin_lock(&devices_lock);
955
956         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
957                 dev = lowpan_dev(entry->netdev);
958                 peer = __peer_lookup_chan(dev, chan);
959                 if (peer) {
960                         last = peer_del(dev, peer);
961                         err = 0;
962
963                         BT_DBG("dev %p removing %speer %p", dev,
964                                last ? "last " : "1 ", peer);
965                         BT_DBG("chan %p orig refcnt %d", chan,
966                                atomic_read(&chan->kref.refcount));
967
968                         l2cap_chan_put(chan);
969                         break;
970                 }
971         }
972
973         if (!err && last && dev && !atomic_read(&dev->peer_count)) {
974                 spin_unlock(&devices_lock);
975
976                 cancel_delayed_work_sync(&dev->notify_peers);
977
978                 ifdown(dev->netdev);
979
980                 if (!removed) {
981                         INIT_WORK(&entry->delete_netdev, delete_netdev);
982                         schedule_work(&entry->delete_netdev);
983                 }
984         } else {
985                 spin_unlock(&devices_lock);
986         }
987
988         return;
989 }
990
991 static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err)
992 {
993         BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn,
994                state_to_string(state), err);
995 }
996
997 static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan,
998                                          unsigned long hdr_len,
999                                          unsigned long len, int nb)
1000 {
1001         /* Note that we must allocate using GFP_ATOMIC here as
1002          * this function is called originally from netdev hard xmit
1003          * function in atomic context.
1004          */
1005         return bt_skb_alloc(hdr_len + len, GFP_ATOMIC);
1006 }
1007
1008 static void chan_suspend_cb(struct l2cap_chan *chan)
1009 {
1010         struct sk_buff *skb = chan->data;
1011
1012         BT_DBG("chan %p conn %p skb %p", chan, chan->conn, skb);
1013
1014         if (!skb)
1015                 return;
1016
1017         lowpan_cb(skb)->status = -EAGAIN;
1018 }
1019
1020 static void chan_resume_cb(struct l2cap_chan *chan)
1021 {
1022         struct sk_buff *skb = chan->data;
1023
1024         BT_DBG("chan %p conn %p skb %p", chan, chan->conn, skb);
1025
1026         if (!skb)
1027                 return;
1028
1029         lowpan_cb(skb)->status = 0;
1030 }
1031
1032 static long chan_get_sndtimeo_cb(struct l2cap_chan *chan)
1033 {
1034         return L2CAP_CONN_TIMEOUT;
1035 }
1036
1037 static const struct l2cap_ops bt_6lowpan_chan_ops = {
1038         .name                   = "L2CAP 6LoWPAN channel",
1039         .new_connection         = chan_new_conn_cb,
1040         .recv                   = chan_recv_cb,
1041         .close                  = chan_close_cb,
1042         .state_change           = chan_state_change_cb,
1043         .ready                  = chan_ready_cb,
1044         .resume                 = chan_resume_cb,
1045         .suspend                = chan_suspend_cb,
1046         .get_sndtimeo           = chan_get_sndtimeo_cb,
1047         .alloc_skb              = chan_alloc_skb_cb,
1048
1049         .teardown               = l2cap_chan_no_teardown,
1050         .defer                  = l2cap_chan_no_defer,
1051         .set_shutdown           = l2cap_chan_no_set_shutdown,
1052 };
1053
1054 static inline __u8 bdaddr_type(__u8 type)
1055 {
1056         if (type == ADDR_LE_DEV_PUBLIC)
1057                 return BDADDR_LE_PUBLIC;
1058         else
1059                 return BDADDR_LE_RANDOM;
1060 }
1061
1062 static struct l2cap_chan *chan_get(void)
1063 {
1064         struct l2cap_chan *pchan;
1065
1066         pchan = chan_create();
1067         if (!pchan)
1068                 return NULL;
1069
1070         pchan->ops = &bt_6lowpan_chan_ops;
1071
1072         return pchan;
1073 }
1074
1075 static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type)
1076 {
1077         struct l2cap_chan *pchan;
1078         int err;
1079
1080         pchan = chan_get();
1081         if (!pchan)
1082                 return -EINVAL;
1083
1084         err = l2cap_chan_connect(pchan, cpu_to_le16(L2CAP_PSM_IPSP), 0,
1085                                  addr, dst_type);
1086
1087         BT_DBG("chan %p err %d", pchan, err);
1088         if (err < 0)
1089                 l2cap_chan_put(pchan);
1090
1091         return err;
1092 }
1093
1094 static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type)
1095 {
1096         struct lowpan_peer *peer;
1097
1098         BT_DBG("conn %p dst type %d", conn, dst_type);
1099
1100         peer = lookup_peer(conn);
1101         if (!peer)
1102                 return -ENOENT;
1103
1104         BT_DBG("peer %p chan %p", peer, peer->chan);
1105
1106         l2cap_chan_close(peer->chan, ENOENT);
1107
1108         return 0;
1109 }
1110
1111 static struct l2cap_chan *bt_6lowpan_listen(void)
1112 {
1113         bdaddr_t *addr = BDADDR_ANY;
1114         struct l2cap_chan *pchan;
1115         int err;
1116
1117         if (!enable_6lowpan)
1118                 return NULL;
1119
1120         pchan = chan_get();
1121         if (!pchan)
1122                 return NULL;
1123
1124         pchan->state = BT_LISTEN;
1125         pchan->src_type = BDADDR_LE_PUBLIC;
1126
1127         atomic_set(&pchan->nesting, L2CAP_NESTING_PARENT);
1128
1129         BT_DBG("chan %p src type %d", pchan, pchan->src_type);
1130
1131         err = l2cap_add_psm(pchan, addr, cpu_to_le16(L2CAP_PSM_IPSP));
1132         if (err) {
1133                 l2cap_chan_put(pchan);
1134                 BT_ERR("psm cannot be added err %d", err);
1135                 return NULL;
1136         }
1137
1138         return pchan;
1139 }
1140
1141 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type,
1142                           struct l2cap_conn **conn)
1143 {
1144         struct hci_conn *hcon;
1145         struct hci_dev *hdev;
1146         bdaddr_t *src = BDADDR_ANY;
1147         int n;
1148
1149         n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu",
1150                    &addr->b[5], &addr->b[4], &addr->b[3],
1151                    &addr->b[2], &addr->b[1], &addr->b[0],
1152                    addr_type);
1153
1154         if (n < 7)
1155                 return -EINVAL;
1156
1157         hdev = hci_get_route(addr, src);
1158         if (!hdev)
1159                 return -ENOENT;
1160
1161         hci_dev_lock(hdev);
1162         hcon = hci_conn_hash_lookup_ba(hdev, LE_LINK, addr);
1163         hci_dev_unlock(hdev);
1164
1165         if (!hcon)
1166                 return -ENOENT;
1167
1168         *conn = (struct l2cap_conn *)hcon->l2cap_data;
1169
1170         BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type);
1171
1172         return 0;
1173 }
1174
1175 static void disconnect_all_peers(void)
1176 {
1177         struct lowpan_dev *entry;
1178         struct lowpan_peer *peer, *tmp_peer, *new_peer;
1179         struct list_head peers;
1180
1181         INIT_LIST_HEAD(&peers);
1182
1183         /* We make a separate list of peers as the close_cb() will
1184          * modify the device peers list so it is better not to mess
1185          * with the same list at the same time.
1186          */
1187
1188         rcu_read_lock();
1189
1190         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1191                 list_for_each_entry_rcu(peer, &entry->peers, list) {
1192                         new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC);
1193                         if (!new_peer)
1194                                 break;
1195
1196                         new_peer->chan = peer->chan;
1197                         INIT_LIST_HEAD(&new_peer->list);
1198
1199                         list_add(&new_peer->list, &peers);
1200                 }
1201         }
1202
1203         rcu_read_unlock();
1204
1205         spin_lock(&devices_lock);
1206         list_for_each_entry_safe(peer, tmp_peer, &peers, list) {
1207                 l2cap_chan_close(peer->chan, ENOENT);
1208
1209                 list_del_rcu(&peer->list);
1210                 kfree_rcu(peer, rcu);
1211
1212                 module_put(THIS_MODULE);
1213         }
1214         spin_unlock(&devices_lock);
1215 }
1216
1217 struct set_enable {
1218         struct work_struct work;
1219         bool flag;
1220 };
1221
1222 static void do_enable_set(struct work_struct *work)
1223 {
1224         struct set_enable *set_enable = container_of(work,
1225                                                      struct set_enable, work);
1226
1227         if (!set_enable->flag || enable_6lowpan != set_enable->flag)
1228                 /* Disconnect existing connections if 6lowpan is
1229                  * disabled
1230                  */
1231                 disconnect_all_peers();
1232
1233         enable_6lowpan = set_enable->flag;
1234
1235         if (listen_chan) {
1236                 l2cap_chan_close(listen_chan, 0);
1237                 l2cap_chan_put(listen_chan);
1238         }
1239
1240         listen_chan = bt_6lowpan_listen();
1241
1242         kfree(set_enable);
1243 }
1244
1245 static int lowpan_enable_set(void *data, u64 val)
1246 {
1247         struct set_enable *set_enable;
1248
1249         set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL);
1250         if (!set_enable)
1251                 return -ENOMEM;
1252
1253         set_enable->flag = !!val;
1254         INIT_WORK(&set_enable->work, do_enable_set);
1255
1256         schedule_work(&set_enable->work);
1257
1258         return 0;
1259 }
1260
1261 static int lowpan_enable_get(void *data, u64 *val)
1262 {
1263         *val = enable_6lowpan;
1264         return 0;
1265 }
1266
1267 DEFINE_SIMPLE_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get,
1268                         lowpan_enable_set, "%llu\n");
1269
1270 static ssize_t lowpan_control_write(struct file *fp,
1271                                     const char __user *user_buffer,
1272                                     size_t count,
1273                                     loff_t *position)
1274 {
1275         char buf[32];
1276         size_t buf_size = min(count, sizeof(buf) - 1);
1277         int ret;
1278         bdaddr_t addr;
1279         u8 addr_type;
1280         struct l2cap_conn *conn = NULL;
1281
1282         if (copy_from_user(buf, user_buffer, buf_size))
1283                 return -EFAULT;
1284
1285         buf[buf_size] = '\0';
1286
1287         if (memcmp(buf, "connect ", 8) == 0) {
1288                 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn);
1289                 if (ret == -EINVAL)
1290                         return ret;
1291
1292                 if (listen_chan) {
1293                         l2cap_chan_close(listen_chan, 0);
1294                         l2cap_chan_put(listen_chan);
1295                         listen_chan = NULL;
1296                 }
1297
1298                 if (conn) {
1299                         struct lowpan_peer *peer;
1300
1301                         if (!is_bt_6lowpan(conn->hcon))
1302                                 return -EINVAL;
1303
1304                         peer = lookup_peer(conn);
1305                         if (peer) {
1306                                 BT_DBG("6LoWPAN connection already exists");
1307                                 return -EALREADY;
1308                         }
1309
1310                         BT_DBG("conn %p dst %pMR type %d user %d", conn,
1311                                &conn->hcon->dst, conn->hcon->dst_type,
1312                                addr_type);
1313                 }
1314
1315                 ret = bt_6lowpan_connect(&addr, addr_type);
1316                 if (ret < 0)
1317                         return ret;
1318
1319                 return count;
1320         }
1321
1322         if (memcmp(buf, "disconnect ", 11) == 0) {
1323                 ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn);
1324                 if (ret < 0)
1325                         return ret;
1326
1327                 ret = bt_6lowpan_disconnect(conn, addr_type);
1328                 if (ret < 0)
1329                         return ret;
1330
1331                 return count;
1332         }
1333
1334         return count;
1335 }
1336
1337 static int lowpan_control_show(struct seq_file *f, void *ptr)
1338 {
1339         struct lowpan_dev *entry;
1340         struct lowpan_peer *peer;
1341
1342         spin_lock(&devices_lock);
1343
1344         list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1345                 list_for_each_entry(peer, &entry->peers, list)
1346                         seq_printf(f, "%pMR (type %u)\n",
1347                                    &peer->chan->dst, peer->chan->dst_type);
1348         }
1349
1350         spin_unlock(&devices_lock);
1351
1352         return 0;
1353 }
1354
1355 static int lowpan_control_open(struct inode *inode, struct file *file)
1356 {
1357         return single_open(file, lowpan_control_show, inode->i_private);
1358 }
1359
1360 static const struct file_operations lowpan_control_fops = {
1361         .open           = lowpan_control_open,
1362         .read           = seq_read,
1363         .write          = lowpan_control_write,
1364         .llseek         = seq_lseek,
1365         .release        = single_release,
1366 };
1367
1368 static void disconnect_devices(void)
1369 {
1370         struct lowpan_dev *entry, *tmp, *new_dev;
1371         struct list_head devices;
1372
1373         INIT_LIST_HEAD(&devices);
1374
1375         /* We make a separate list of devices because the unregister_netdev()
1376          * will call device_event() which will also want to modify the same
1377          * devices list.
1378          */
1379
1380         rcu_read_lock();
1381
1382         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1383                 new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC);
1384                 if (!new_dev)
1385                         break;
1386
1387                 new_dev->netdev = entry->netdev;
1388                 INIT_LIST_HEAD(&new_dev->list);
1389
1390                 list_add_rcu(&new_dev->list, &devices);
1391         }
1392
1393         rcu_read_unlock();
1394
1395         list_for_each_entry_safe(entry, tmp, &devices, list) {
1396                 ifdown(entry->netdev);
1397                 BT_DBG("Unregistering netdev %s %p",
1398                        entry->netdev->name, entry->netdev);
1399                 unregister_netdev(entry->netdev);
1400                 kfree(entry);
1401         }
1402 }
1403
1404 static int device_event(struct notifier_block *unused,
1405                         unsigned long event, void *ptr)
1406 {
1407         struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
1408         struct lowpan_dev *entry;
1409
1410         if (netdev->type != ARPHRD_6LOWPAN)
1411                 return NOTIFY_DONE;
1412
1413         switch (event) {
1414         case NETDEV_UNREGISTER:
1415                 spin_lock(&devices_lock);
1416                 list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1417                         if (entry->netdev == netdev) {
1418                                 BT_DBG("Unregistered netdev %s %p",
1419                                        netdev->name, netdev);
1420                                 list_del(&entry->list);
1421                                 kfree(entry);
1422                                 break;
1423                         }
1424                 }
1425                 spin_unlock(&devices_lock);
1426                 break;
1427         }
1428
1429         return NOTIFY_DONE;
1430 }
1431
1432 static struct notifier_block bt_6lowpan_dev_notifier = {
1433         .notifier_call = device_event,
1434 };
1435
1436 static int __init bt_6lowpan_init(void)
1437 {
1438         lowpan_enable_debugfs = debugfs_create_file("6lowpan_enable", 0644,
1439                                                     bt_debugfs, NULL,
1440                                                     &lowpan_enable_fops);
1441         lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644,
1442                                                      bt_debugfs, NULL,
1443                                                      &lowpan_control_fops);
1444
1445         return register_netdevice_notifier(&bt_6lowpan_dev_notifier);
1446 }
1447
1448 static void __exit bt_6lowpan_exit(void)
1449 {
1450         debugfs_remove(lowpan_enable_debugfs);
1451         debugfs_remove(lowpan_control_debugfs);
1452
1453         if (listen_chan) {
1454                 l2cap_chan_close(listen_chan, 0);
1455                 l2cap_chan_put(listen_chan);
1456         }
1457
1458         disconnect_devices();
1459
1460         unregister_netdevice_notifier(&bt_6lowpan_dev_notifier);
1461 }
1462
1463 module_init(bt_6lowpan_init);
1464 module_exit(bt_6lowpan_exit);
1465
1466 MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>");
1467 MODULE_DESCRIPTION("Bluetooth 6LoWPAN");
1468 MODULE_VERSION(VERSION);
1469 MODULE_LICENSE("GPL");