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TOMOYO Linux Cross Reference
Linux/net/bluetooth/6lowpan.c

Version: ~ [ linux-5.5 ] ~ [ linux-5.4.15 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.98 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.167 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.211 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.211 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.81 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
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  1 /*
  2    Copyright (c) 2013-2014 Intel Corp.
  3 
  4    This program is free software; you can redistribute it and/or modify
  5    it under the terms of the GNU General Public License version 2 and
  6    only version 2 as published by the Free Software Foundation.
  7 
  8    This program is distributed in the hope that it will be useful,
  9    but WITHOUT ANY WARRANTY; without even the implied warranty of
 10    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 11    GNU General Public License for more details.
 12 */
 13 
 14 #include <linux/if_arp.h>
 15 #include <linux/netdevice.h>
 16 #include <linux/etherdevice.h>
 17 #include <linux/module.h>
 18 #include <linux/debugfs.h>
 19 
 20 #include <net/ipv6.h>
 21 #include <net/ip6_route.h>
 22 #include <net/addrconf.h>
 23 #include <net/pkt_sched.h>
 24 
 25 #include <net/bluetooth/bluetooth.h>
 26 #include <net/bluetooth/hci_core.h>
 27 #include <net/bluetooth/l2cap.h>
 28 
 29 #include <net/6lowpan.h> /* for the compression support */
 30 
 31 #define VERSION "0.1"
 32 
 33 static struct dentry *lowpan_enable_debugfs;
 34 static struct dentry *lowpan_control_debugfs;
 35 
 36 #define IFACE_NAME_TEMPLATE "bt%d"
 37 
 38 struct skb_cb {
 39         struct in6_addr addr;
 40         struct in6_addr gw;
 41         struct l2cap_chan *chan;
 42 };
 43 #define lowpan_cb(skb) ((struct skb_cb *)((skb)->cb))
 44 
 45 /* The devices list contains those devices that we are acting
 46  * as a proxy. The BT 6LoWPAN device is a virtual device that
 47  * connects to the Bluetooth LE device. The real connection to
 48  * BT device is done via l2cap layer. There exists one
 49  * virtual device / one BT 6LoWPAN network (=hciX device).
 50  * The list contains struct lowpan_dev elements.
 51  */
 52 static LIST_HEAD(bt_6lowpan_devices);
 53 static DEFINE_SPINLOCK(devices_lock);
 54 
 55 static bool enable_6lowpan;
 56 
 57 /* We are listening incoming connections via this channel
 58  */
 59 static struct l2cap_chan *listen_chan;
 60 
 61 struct lowpan_peer {
 62         struct list_head list;
 63         struct rcu_head rcu;
 64         struct l2cap_chan *chan;
 65 
 66         /* peer addresses in various formats */
 67         unsigned char lladdr[ETH_ALEN];
 68         struct in6_addr peer_addr;
 69 };
 70 
 71 struct lowpan_btle_dev {
 72         struct list_head list;
 73 
 74         struct hci_dev *hdev;
 75         struct net_device *netdev;
 76         struct list_head peers;
 77         atomic_t peer_count; /* number of items in peers list */
 78 
 79         struct work_struct delete_netdev;
 80         struct delayed_work notify_peers;
 81 };
 82 
 83 static inline struct lowpan_btle_dev *
 84 lowpan_btle_dev(const struct net_device *netdev)
 85 {
 86         return (struct lowpan_btle_dev *)lowpan_dev(netdev)->priv;
 87 }
 88 
 89 static inline void peer_add(struct lowpan_btle_dev *dev,
 90                             struct lowpan_peer *peer)
 91 {
 92         list_add_rcu(&peer->list, &dev->peers);
 93         atomic_inc(&dev->peer_count);
 94 }
 95 
 96 static inline bool peer_del(struct lowpan_btle_dev *dev,
 97                             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_btle_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 *
141 __peer_lookup_chan(struct lowpan_btle_dev *dev, 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 *
154 __peer_lookup_conn(struct lowpan_btle_dev *dev, 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_btle_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, daddr);
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_btle_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_btle_dev *lookup_dev(struct l2cap_conn *conn)
243 {
244         struct lowpan_btle_dev *entry;
245         struct lowpan_btle_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_ni(skb_cp);
270 }
271 
272 static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev,
273                            struct lowpan_peer *peer)
274 {
275         const u8 *saddr;
276 
277         saddr = peer->lladdr;
278 
279         return lowpan_header_decompress(skb, netdev, netdev->dev_addr, saddr);
280 }
281 
282 static int recv_pkt(struct sk_buff *skb, struct net_device *dev,
283                     struct lowpan_peer *peer)
284 {
285         struct sk_buff *local_skb;
286         int ret;
287 
288         if (!netif_running(dev))
289                 goto drop;
290 
291         if (dev->type != ARPHRD_6LOWPAN || !skb->len)
292                 goto drop;
293 
294         skb_reset_network_header(skb);
295 
296         skb = skb_share_check(skb, GFP_ATOMIC);
297         if (!skb)
298                 goto drop;
299 
300         /* check that it's our buffer */
301         if (lowpan_is_ipv6(*skb_network_header(skb))) {
302                 /* Pull off the 1-byte of 6lowpan header. */
303                 skb_pull(skb, 1);
304 
305                 /* Copy the packet so that the IPv6 header is
306                  * properly aligned.
307                  */
308                 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
309                                             skb_tailroom(skb), GFP_ATOMIC);
310                 if (!local_skb)
311                         goto drop;
312 
313                 local_skb->protocol = htons(ETH_P_IPV6);
314                 local_skb->pkt_type = PACKET_HOST;
315                 local_skb->dev = dev;
316 
317                 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
318 
319                 if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) {
320                         kfree_skb(local_skb);
321                         goto drop;
322                 }
323 
324                 dev->stats.rx_bytes += skb->len;
325                 dev->stats.rx_packets++;
326 
327                 consume_skb(local_skb);
328                 consume_skb(skb);
329         } else if (lowpan_is_iphc(*skb_network_header(skb))) {
330                 local_skb = skb_clone(skb, GFP_ATOMIC);
331                 if (!local_skb)
332                         goto drop;
333 
334                 local_skb->dev = dev;
335 
336                 ret = iphc_decompress(local_skb, dev, peer);
337                 if (ret < 0) {
338                         BT_DBG("iphc_decompress failed: %d", ret);
339                         kfree_skb(local_skb);
340                         goto drop;
341                 }
342 
343                 local_skb->protocol = htons(ETH_P_IPV6);
344                 local_skb->pkt_type = PACKET_HOST;
345 
346                 if (give_skb_to_upper(local_skb, dev)
347                                 != NET_RX_SUCCESS) {
348                         kfree_skb(local_skb);
349                         goto drop;
350                 }
351 
352                 dev->stats.rx_bytes += skb->len;
353                 dev->stats.rx_packets++;
354 
355                 consume_skb(local_skb);
356                 consume_skb(skb);
357         } else {
358                 BT_DBG("unknown packet type");
359                 goto drop;
360         }
361 
362         return NET_RX_SUCCESS;
363 
364 drop:
365         dev->stats.rx_dropped++;
366         return NET_RX_DROP;
367 }
368 
369 /* Packet from BT LE device */
370 static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
371 {
372         struct lowpan_btle_dev *dev;
373         struct lowpan_peer *peer;
374         int err;
375 
376         peer = lookup_peer(chan->conn);
377         if (!peer)
378                 return -ENOENT;
379 
380         dev = lookup_dev(chan->conn);
381         if (!dev || !dev->netdev)
382                 return -ENOENT;
383 
384         err = recv_pkt(skb, dev->netdev, peer);
385         if (err) {
386                 BT_DBG("recv pkt %d", err);
387                 err = -EAGAIN;
388         }
389 
390         return err;
391 }
392 
393 static int setup_header(struct sk_buff *skb, struct net_device *netdev,
394                         bdaddr_t *peer_addr, u8 *peer_addr_type)
395 {
396         struct in6_addr ipv6_daddr;
397         struct ipv6hdr *hdr;
398         struct lowpan_btle_dev *dev;
399         struct lowpan_peer *peer;
400         u8 *daddr;
401         int err, status = 0;
402 
403         hdr = ipv6_hdr(skb);
404 
405         dev = lowpan_btle_dev(netdev);
406 
407         memcpy(&ipv6_daddr, &hdr->daddr, sizeof(ipv6_daddr));
408 
409         if (ipv6_addr_is_multicast(&ipv6_daddr)) {
410                 lowpan_cb(skb)->chan = NULL;
411                 daddr = NULL;
412         } else {
413                 BT_DBG("dest IP %pI6c", &ipv6_daddr);
414 
415                 /* The packet might be sent to 6lowpan interface
416                  * because of routing (either via default route
417                  * or user set route) so get peer according to
418                  * the destination address.
419                  */
420                 peer = peer_lookup_dst(dev, &ipv6_daddr, skb);
421                 if (!peer) {
422                         BT_DBG("no such peer");
423                         return -ENOENT;
424                 }
425 
426                 daddr = peer->lladdr;
427                 *peer_addr = peer->chan->dst;
428                 *peer_addr_type = peer->chan->dst_type;
429                 lowpan_cb(skb)->chan = peer->chan;
430 
431                 status = 1;
432         }
433 
434         lowpan_header_compress(skb, netdev, daddr, dev->netdev->dev_addr);
435 
436         err = dev_hard_header(skb, netdev, ETH_P_IPV6, NULL, NULL, 0);
437         if (err < 0)
438                 return err;
439 
440         return status;
441 }
442 
443 static int header_create(struct sk_buff *skb, struct net_device *netdev,
444                          unsigned short type, const void *_daddr,
445                          const void *_saddr, unsigned int len)
446 {
447         if (type != ETH_P_IPV6)
448                 return -EINVAL;
449 
450         return 0;
451 }
452 
453 /* Packet to BT LE device */
454 static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb,
455                     struct net_device *netdev)
456 {
457         struct msghdr msg;
458         struct kvec iv;
459         int err;
460 
461         /* Remember the skb so that we can send EAGAIN to the caller if
462          * we run out of credits.
463          */
464         chan->data = skb;
465 
466         iv.iov_base = skb->data;
467         iv.iov_len = skb->len;
468 
469         memset(&msg, 0, sizeof(msg));
470         iov_iter_kvec(&msg.msg_iter, WRITE, &iv, 1, skb->len);
471 
472         err = l2cap_chan_send(chan, &msg, skb->len);
473         if (err > 0) {
474                 netdev->stats.tx_bytes += err;
475                 netdev->stats.tx_packets++;
476                 return 0;
477         }
478 
479         if (err < 0)
480                 netdev->stats.tx_errors++;
481 
482         return err;
483 }
484 
485 static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev)
486 {
487         struct sk_buff *local_skb;
488         struct lowpan_btle_dev *entry;
489         int err = 0;
490 
491         rcu_read_lock();
492 
493         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
494                 struct lowpan_peer *pentry;
495                 struct lowpan_btle_dev *dev;
496 
497                 if (entry->netdev != netdev)
498                         continue;
499 
500                 dev = lowpan_btle_dev(entry->netdev);
501 
502                 list_for_each_entry_rcu(pentry, &dev->peers, list) {
503                         int ret;
504 
505                         local_skb = skb_clone(skb, GFP_ATOMIC);
506 
507                         BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
508                                netdev->name,
509                                &pentry->chan->dst, pentry->chan->dst_type,
510                                &pentry->peer_addr, pentry->chan);
511                         ret = send_pkt(pentry->chan, local_skb, netdev);
512                         if (ret < 0)
513                                 err = ret;
514 
515                         kfree_skb(local_skb);
516                 }
517         }
518 
519         rcu_read_unlock();
520 
521         return err;
522 }
523 
524 static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev)
525 {
526         int err = 0;
527         bdaddr_t addr;
528         u8 addr_type;
529 
530         /* We must take a copy of the skb before we modify/replace the ipv6
531          * header as the header could be used elsewhere
532          */
533         skb = skb_unshare(skb, GFP_ATOMIC);
534         if (!skb)
535                 return NET_XMIT_DROP;
536 
537         /* Return values from setup_header()
538          *  <0 - error, packet is dropped
539          *   0 - this is a multicast packet
540          *   1 - this is unicast packet
541          */
542         err = setup_header(skb, netdev, &addr, &addr_type);
543         if (err < 0) {
544                 kfree_skb(skb);
545                 return NET_XMIT_DROP;
546         }
547 
548         if (err) {
549                 if (lowpan_cb(skb)->chan) {
550                         BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
551                                netdev->name, &addr, addr_type,
552                                &lowpan_cb(skb)->addr, lowpan_cb(skb)->chan);
553                         err = send_pkt(lowpan_cb(skb)->chan, skb, netdev);
554                 } else {
555                         err = -ENOENT;
556                 }
557         } else {
558                 /* We need to send the packet to every device behind this
559                  * interface.
560                  */
561                 err = send_mcast_pkt(skb, netdev);
562         }
563 
564         dev_kfree_skb(skb);
565 
566         if (err)
567                 BT_DBG("ERROR: xmit failed (%d)", err);
568 
569         return err < 0 ? NET_XMIT_DROP : err;
570 }
571 
572 static int bt_dev_init(struct net_device *dev)
573 {
574         netdev_lockdep_set_classes(dev);
575 
576         return 0;
577 }
578 
579 static const struct net_device_ops netdev_ops = {
580         .ndo_init               = bt_dev_init,
581         .ndo_start_xmit         = bt_xmit,
582 };
583 
584 static struct header_ops header_ops = {
585         .create = header_create,
586 };
587 
588 static void netdev_setup(struct net_device *dev)
589 {
590         dev->hard_header_len    = 0;
591         dev->needed_tailroom    = 0;
592         dev->flags              = IFF_RUNNING | IFF_MULTICAST;
593         dev->watchdog_timeo     = 0;
594         dev->tx_queue_len       = DEFAULT_TX_QUEUE_LEN;
595 
596         dev->netdev_ops         = &netdev_ops;
597         dev->header_ops         = &header_ops;
598         dev->needs_free_netdev  = true;
599 }
600 
601 static struct device_type bt_type = {
602         .name   = "bluetooth",
603 };
604 
605 static void ifup(struct net_device *netdev)
606 {
607         int err;
608 
609         rtnl_lock();
610         err = dev_open(netdev);
611         if (err < 0)
612                 BT_INFO("iface %s cannot be opened (%d)", netdev->name, err);
613         rtnl_unlock();
614 }
615 
616 static void ifdown(struct net_device *netdev)
617 {
618         rtnl_lock();
619         dev_close(netdev);
620         rtnl_unlock();
621 }
622 
623 static void do_notify_peers(struct work_struct *work)
624 {
625         struct lowpan_btle_dev *dev = container_of(work, struct lowpan_btle_dev,
626                                                    notify_peers.work);
627 
628         netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */
629 }
630 
631 static bool is_bt_6lowpan(struct hci_conn *hcon)
632 {
633         if (hcon->type != LE_LINK)
634                 return false;
635 
636         if (!enable_6lowpan)
637                 return false;
638 
639         return true;
640 }
641 
642 static struct l2cap_chan *chan_create(void)
643 {
644         struct l2cap_chan *chan;
645 
646         chan = l2cap_chan_create();
647         if (!chan)
648                 return NULL;
649 
650         l2cap_chan_set_defaults(chan);
651 
652         chan->chan_type = L2CAP_CHAN_CONN_ORIENTED;
653         chan->mode = L2CAP_MODE_LE_FLOWCTL;
654         chan->imtu = 1280;
655 
656         return chan;
657 }
658 
659 static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan,
660                                         struct lowpan_btle_dev *dev,
661                                         bool new_netdev)
662 {
663         struct lowpan_peer *peer;
664 
665         peer = kzalloc(sizeof(*peer), GFP_ATOMIC);
666         if (!peer)
667                 return NULL;
668 
669         peer->chan = chan;
670         memset(&peer->peer_addr, 0, sizeof(struct in6_addr));
671 
672         baswap((void *)peer->lladdr, &chan->dst);
673 
674         lowpan_iphc_uncompress_eui48_lladdr(&peer->peer_addr, peer->lladdr);
675 
676         spin_lock(&devices_lock);
677         INIT_LIST_HEAD(&peer->list);
678         peer_add(dev, peer);
679         spin_unlock(&devices_lock);
680 
681         /* Notifying peers about us needs to be done without locks held */
682         if (new_netdev)
683                 INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers);
684         schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100));
685 
686         return peer->chan;
687 }
688 
689 static int setup_netdev(struct l2cap_chan *chan, struct lowpan_btle_dev **dev)
690 {
691         struct net_device *netdev;
692         int err = 0;
693 
694         netdev = alloc_netdev(LOWPAN_PRIV_SIZE(sizeof(struct lowpan_btle_dev)),
695                               IFACE_NAME_TEMPLATE, NET_NAME_UNKNOWN,
696                               netdev_setup);
697         if (!netdev)
698                 return -ENOMEM;
699 
700         netdev->addr_assign_type = NET_ADDR_PERM;
701         baswap((void *)netdev->dev_addr, &chan->src);
702 
703         netdev->netdev_ops = &netdev_ops;
704         SET_NETDEV_DEV(netdev, &chan->conn->hcon->hdev->dev);
705         SET_NETDEV_DEVTYPE(netdev, &bt_type);
706 
707         *dev = lowpan_btle_dev(netdev);
708         (*dev)->netdev = netdev;
709         (*dev)->hdev = chan->conn->hcon->hdev;
710         INIT_LIST_HEAD(&(*dev)->peers);
711 
712         spin_lock(&devices_lock);
713         INIT_LIST_HEAD(&(*dev)->list);
714         list_add_rcu(&(*dev)->list, &bt_6lowpan_devices);
715         spin_unlock(&devices_lock);
716 
717         err = lowpan_register_netdev(netdev, LOWPAN_LLTYPE_BTLE);
718         if (err < 0) {
719                 BT_INFO("register_netdev failed %d", err);
720                 spin_lock(&devices_lock);
721                 list_del_rcu(&(*dev)->list);
722                 spin_unlock(&devices_lock);
723                 free_netdev(netdev);
724                 goto out;
725         }
726 
727         BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d",
728                netdev->ifindex, &chan->dst, chan->dst_type,
729                &chan->src, chan->src_type);
730         set_bit(__LINK_STATE_PRESENT, &netdev->state);
731 
732         return 0;
733 
734 out:
735         return err;
736 }
737 
738 static inline void chan_ready_cb(struct l2cap_chan *chan)
739 {
740         struct lowpan_btle_dev *dev;
741         bool new_netdev = false;
742 
743         dev = lookup_dev(chan->conn);
744 
745         BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev);
746 
747         if (!dev) {
748                 if (setup_netdev(chan, &dev) < 0) {
749                         l2cap_chan_del(chan, -ENOENT);
750                         return;
751                 }
752                 new_netdev = true;
753         }
754 
755         if (!try_module_get(THIS_MODULE))
756                 return;
757 
758         add_peer_chan(chan, dev, new_netdev);
759         ifup(dev->netdev);
760 }
761 
762 static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan)
763 {
764         struct l2cap_chan *chan;
765 
766         chan = chan_create();
767         if (!chan)
768                 return NULL;
769 
770         chan->ops = pchan->ops;
771 
772         BT_DBG("chan %p pchan %p", chan, pchan);
773 
774         return chan;
775 }
776 
777 static void delete_netdev(struct work_struct *work)
778 {
779         struct lowpan_btle_dev *entry = container_of(work,
780                                                      struct lowpan_btle_dev,
781                                                      delete_netdev);
782 
783         lowpan_unregister_netdev(entry->netdev);
784 
785         /* The entry pointer is deleted by the netdev destructor. */
786 }
787 
788 static void chan_close_cb(struct l2cap_chan *chan)
789 {
790         struct lowpan_btle_dev *entry;
791         struct lowpan_btle_dev *dev = NULL;
792         struct lowpan_peer *peer;
793         int err = -ENOENT;
794         bool last = false, remove = true;
795 
796         BT_DBG("chan %p conn %p", chan, chan->conn);
797 
798         if (chan->conn && chan->conn->hcon) {
799                 if (!is_bt_6lowpan(chan->conn->hcon))
800                         return;
801 
802                 /* If conn is set, then the netdev is also there and we should
803                  * not remove it.
804                  */
805                 remove = false;
806         }
807 
808         spin_lock(&devices_lock);
809 
810         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
811                 dev = lowpan_btle_dev(entry->netdev);
812                 peer = __peer_lookup_chan(dev, chan);
813                 if (peer) {
814                         last = peer_del(dev, peer);
815                         err = 0;
816 
817                         BT_DBG("dev %p removing %speer %p", dev,
818                                last ? "last " : "1 ", peer);
819                         BT_DBG("chan %p orig refcnt %d", chan,
820                                kref_read(&chan->kref));
821 
822                         l2cap_chan_put(chan);
823                         break;
824                 }
825         }
826 
827         if (!err && last && dev && !atomic_read(&dev->peer_count)) {
828                 spin_unlock(&devices_lock);
829 
830                 cancel_delayed_work_sync(&dev->notify_peers);
831 
832                 ifdown(dev->netdev);
833 
834                 if (remove) {
835                         INIT_WORK(&entry->delete_netdev, delete_netdev);
836                         schedule_work(&entry->delete_netdev);
837                 }
838         } else {
839                 spin_unlock(&devices_lock);
840         }
841 
842         return;
843 }
844 
845 static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err)
846 {
847         BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn,
848                state_to_string(state), err);
849 }
850 
851 static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan,
852                                          unsigned long hdr_len,
853                                          unsigned long len, int nb)
854 {
855         /* Note that we must allocate using GFP_ATOMIC here as
856          * this function is called originally from netdev hard xmit
857          * function in atomic context.
858          */
859         return bt_skb_alloc(hdr_len + len, GFP_ATOMIC);
860 }
861 
862 static void chan_suspend_cb(struct l2cap_chan *chan)
863 {
864         struct lowpan_btle_dev *dev;
865 
866         BT_DBG("chan %p suspend", chan);
867 
868         dev = lookup_dev(chan->conn);
869         if (!dev || !dev->netdev)
870                 return;
871 
872         netif_stop_queue(dev->netdev);
873 }
874 
875 static void chan_resume_cb(struct l2cap_chan *chan)
876 {
877         struct lowpan_btle_dev *dev;
878 
879         BT_DBG("chan %p resume", chan);
880 
881         dev = lookup_dev(chan->conn);
882         if (!dev || !dev->netdev)
883                 return;
884 
885         netif_wake_queue(dev->netdev);
886 }
887 
888 static long chan_get_sndtimeo_cb(struct l2cap_chan *chan)
889 {
890         return L2CAP_CONN_TIMEOUT;
891 }
892 
893 static const struct l2cap_ops bt_6lowpan_chan_ops = {
894         .name                   = "L2CAP 6LoWPAN channel",
895         .new_connection         = chan_new_conn_cb,
896         .recv                   = chan_recv_cb,
897         .close                  = chan_close_cb,
898         .state_change           = chan_state_change_cb,
899         .ready                  = chan_ready_cb,
900         .resume                 = chan_resume_cb,
901         .suspend                = chan_suspend_cb,
902         .get_sndtimeo           = chan_get_sndtimeo_cb,
903         .alloc_skb              = chan_alloc_skb_cb,
904 
905         .teardown               = l2cap_chan_no_teardown,
906         .defer                  = l2cap_chan_no_defer,
907         .set_shutdown           = l2cap_chan_no_set_shutdown,
908 };
909 
910 static inline __u8 bdaddr_type(__u8 type)
911 {
912         if (type == ADDR_LE_DEV_PUBLIC)
913                 return BDADDR_LE_PUBLIC;
914         else
915                 return BDADDR_LE_RANDOM;
916 }
917 
918 static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type)
919 {
920         struct l2cap_chan *chan;
921         int err;
922 
923         chan = chan_create();
924         if (!chan)
925                 return -EINVAL;
926 
927         chan->ops = &bt_6lowpan_chan_ops;
928 
929         err = l2cap_chan_connect(chan, cpu_to_le16(L2CAP_PSM_IPSP), 0,
930                                  addr, dst_type);
931 
932         BT_DBG("chan %p err %d", chan, err);
933         if (err < 0)
934                 l2cap_chan_put(chan);
935 
936         return err;
937 }
938 
939 static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type)
940 {
941         struct lowpan_peer *peer;
942 
943         BT_DBG("conn %p dst type %d", conn, dst_type);
944 
945         peer = lookup_peer(conn);
946         if (!peer)
947                 return -ENOENT;
948 
949         BT_DBG("peer %p chan %p", peer, peer->chan);
950 
951         l2cap_chan_close(peer->chan, ENOENT);
952 
953         return 0;
954 }
955 
956 static struct l2cap_chan *bt_6lowpan_listen(void)
957 {
958         bdaddr_t *addr = BDADDR_ANY;
959         struct l2cap_chan *chan;
960         int err;
961 
962         if (!enable_6lowpan)
963                 return NULL;
964 
965         chan = chan_create();
966         if (!chan)
967                 return NULL;
968 
969         chan->ops = &bt_6lowpan_chan_ops;
970         chan->state = BT_LISTEN;
971         chan->src_type = BDADDR_LE_PUBLIC;
972 
973         atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
974 
975         BT_DBG("chan %p src type %d", chan, chan->src_type);
976 
977         err = l2cap_add_psm(chan, addr, cpu_to_le16(L2CAP_PSM_IPSP));
978         if (err) {
979                 l2cap_chan_put(chan);
980                 BT_ERR("psm cannot be added err %d", err);
981                 return NULL;
982         }
983 
984         return chan;
985 }
986 
987 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type,
988                           struct l2cap_conn **conn)
989 {
990         struct hci_conn *hcon;
991         struct hci_dev *hdev;
992         int n;
993 
994         n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu",
995                    &addr->b[5], &addr->b[4], &addr->b[3],
996                    &addr->b[2], &addr->b[1], &addr->b[0],
997                    addr_type);
998 
999         if (n < 7)
1000                 return -EINVAL;
1001 
1002         /* The LE_PUBLIC address type is ignored because of BDADDR_ANY */
1003         hdev = hci_get_route(addr, BDADDR_ANY, BDADDR_LE_PUBLIC);
1004         if (!hdev)
1005                 return -ENOENT;
1006 
1007         hci_dev_lock(hdev);
1008         hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type);
1009         hci_dev_unlock(hdev);
1010 
1011         if (!hcon)
1012                 return -ENOENT;
1013 
1014         *conn = (struct l2cap_conn *)hcon->l2cap_data;
1015 
1016         BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type);
1017 
1018         return 0;
1019 }
1020 
1021 static void disconnect_all_peers(void)
1022 {
1023         struct lowpan_btle_dev *entry;
1024         struct lowpan_peer *peer, *tmp_peer, *new_peer;
1025         struct list_head peers;
1026 
1027         INIT_LIST_HEAD(&peers);
1028 
1029         /* We make a separate list of peers as the close_cb() will
1030          * modify the device peers list so it is better not to mess
1031          * with the same list at the same time.
1032          */
1033 
1034         rcu_read_lock();
1035 
1036         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1037                 list_for_each_entry_rcu(peer, &entry->peers, list) {
1038                         new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC);
1039                         if (!new_peer)
1040                                 break;
1041 
1042                         new_peer->chan = peer->chan;
1043                         INIT_LIST_HEAD(&new_peer->list);
1044 
1045                         list_add(&new_peer->list, &peers);
1046                 }
1047         }
1048 
1049         rcu_read_unlock();
1050 
1051         spin_lock(&devices_lock);
1052         list_for_each_entry_safe(peer, tmp_peer, &peers, list) {
1053                 l2cap_chan_close(peer->chan, ENOENT);
1054 
1055                 list_del_rcu(&peer->list);
1056                 kfree_rcu(peer, rcu);
1057         }
1058         spin_unlock(&devices_lock);
1059 }
1060 
1061 struct set_enable {
1062         struct work_struct work;
1063         bool flag;
1064 };
1065 
1066 static void do_enable_set(struct work_struct *work)
1067 {
1068         struct set_enable *set_enable = container_of(work,
1069                                                      struct set_enable, work);
1070 
1071         if (!set_enable->flag || enable_6lowpan != set_enable->flag)
1072                 /* Disconnect existing connections if 6lowpan is
1073                  * disabled
1074                  */
1075                 disconnect_all_peers();
1076 
1077         enable_6lowpan = set_enable->flag;
1078 
1079         if (listen_chan) {
1080                 l2cap_chan_close(listen_chan, 0);
1081                 l2cap_chan_put(listen_chan);
1082         }
1083 
1084         listen_chan = bt_6lowpan_listen();
1085 
1086         kfree(set_enable);
1087 }
1088 
1089 static int lowpan_enable_set(void *data, u64 val)
1090 {
1091         struct set_enable *set_enable;
1092 
1093         set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL);
1094         if (!set_enable)
1095                 return -ENOMEM;
1096 
1097         set_enable->flag = !!val;
1098         INIT_WORK(&set_enable->work, do_enable_set);
1099 
1100         schedule_work(&set_enable->work);
1101 
1102         return 0;
1103 }
1104 
1105 static int lowpan_enable_get(void *data, u64 *val)
1106 {
1107         *val = enable_6lowpan;
1108         return 0;
1109 }
1110 
1111 DEFINE_SIMPLE_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get,
1112                         lowpan_enable_set, "%llu\n");
1113 
1114 static ssize_t lowpan_control_write(struct file *fp,
1115                                     const char __user *user_buffer,
1116                                     size_t count,
1117                                     loff_t *position)
1118 {
1119         char buf[32];
1120         size_t buf_size = min(count, sizeof(buf) - 1);
1121         int ret;
1122         bdaddr_t addr;
1123         u8 addr_type;
1124         struct l2cap_conn *conn = NULL;
1125 
1126         if (copy_from_user(buf, user_buffer, buf_size))
1127                 return -EFAULT;
1128 
1129         buf[buf_size] = '\0';
1130 
1131         if (memcmp(buf, "connect ", 8) == 0) {
1132                 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn);
1133                 if (ret == -EINVAL)
1134                         return ret;
1135 
1136                 if (listen_chan) {
1137                         l2cap_chan_close(listen_chan, 0);
1138                         l2cap_chan_put(listen_chan);
1139                         listen_chan = NULL;
1140                 }
1141 
1142                 if (conn) {
1143                         struct lowpan_peer *peer;
1144 
1145                         if (!is_bt_6lowpan(conn->hcon))
1146                                 return -EINVAL;
1147 
1148                         peer = lookup_peer(conn);
1149                         if (peer) {
1150                                 BT_DBG("6LoWPAN connection already exists");
1151                                 return -EALREADY;
1152                         }
1153 
1154                         BT_DBG("conn %p dst %pMR type %d user %d", conn,
1155                                &conn->hcon->dst, conn->hcon->dst_type,
1156                                addr_type);
1157                 }
1158 
1159                 ret = bt_6lowpan_connect(&addr, addr_type);
1160                 if (ret < 0)
1161                         return ret;
1162 
1163                 return count;
1164         }
1165 
1166         if (memcmp(buf, "disconnect ", 11) == 0) {
1167                 ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn);
1168                 if (ret < 0)
1169                         return ret;
1170 
1171                 ret = bt_6lowpan_disconnect(conn, addr_type);
1172                 if (ret < 0)
1173                         return ret;
1174 
1175                 return count;
1176         }
1177 
1178         return count;
1179 }
1180 
1181 static int lowpan_control_show(struct seq_file *f, void *ptr)
1182 {
1183         struct lowpan_btle_dev *entry;
1184         struct lowpan_peer *peer;
1185 
1186         spin_lock(&devices_lock);
1187 
1188         list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1189                 list_for_each_entry(peer, &entry->peers, list)
1190                         seq_printf(f, "%pMR (type %u)\n",
1191                                    &peer->chan->dst, peer->chan->dst_type);
1192         }
1193 
1194         spin_unlock(&devices_lock);
1195 
1196         return 0;
1197 }
1198 
1199 static int lowpan_control_open(struct inode *inode, struct file *file)
1200 {
1201         return single_open(file, lowpan_control_show, inode->i_private);
1202 }
1203 
1204 static const struct file_operations lowpan_control_fops = {
1205         .open           = lowpan_control_open,
1206         .read           = seq_read,
1207         .write          = lowpan_control_write,
1208         .llseek         = seq_lseek,
1209         .release        = single_release,
1210 };
1211 
1212 static void disconnect_devices(void)
1213 {
1214         struct lowpan_btle_dev *entry, *tmp, *new_dev;
1215         struct list_head devices;
1216 
1217         INIT_LIST_HEAD(&devices);
1218 
1219         /* We make a separate list of devices because the unregister_netdev()
1220          * will call device_event() which will also want to modify the same
1221          * devices list.
1222          */
1223 
1224         rcu_read_lock();
1225 
1226         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1227                 new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC);
1228                 if (!new_dev)
1229                         break;
1230 
1231                 new_dev->netdev = entry->netdev;
1232                 INIT_LIST_HEAD(&new_dev->list);
1233 
1234                 list_add_rcu(&new_dev->list, &devices);
1235         }
1236 
1237         rcu_read_unlock();
1238 
1239         list_for_each_entry_safe(entry, tmp, &devices, list) {
1240                 ifdown(entry->netdev);
1241                 BT_DBG("Unregistering netdev %s %p",
1242                        entry->netdev->name, entry->netdev);
1243                 lowpan_unregister_netdev(entry->netdev);
1244                 kfree(entry);
1245         }
1246 }
1247 
1248 static int device_event(struct notifier_block *unused,
1249                         unsigned long event, void *ptr)
1250 {
1251         struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
1252         struct lowpan_btle_dev *entry;
1253 
1254         if (netdev->type != ARPHRD_6LOWPAN)
1255                 return NOTIFY_DONE;
1256 
1257         switch (event) {
1258         case NETDEV_UNREGISTER:
1259                 spin_lock(&devices_lock);
1260                 list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1261                         if (entry->netdev == netdev) {
1262                                 BT_DBG("Unregistered netdev %s %p",
1263                                        netdev->name, netdev);
1264                                 list_del(&entry->list);
1265                                 break;
1266                         }
1267                 }
1268                 spin_unlock(&devices_lock);
1269                 break;
1270         }
1271 
1272         return NOTIFY_DONE;
1273 }
1274 
1275 static struct notifier_block bt_6lowpan_dev_notifier = {
1276         .notifier_call = device_event,
1277 };
1278 
1279 static int __init bt_6lowpan_init(void)
1280 {
1281         lowpan_enable_debugfs = debugfs_create_file("6lowpan_enable", 0644,
1282                                                     bt_debugfs, NULL,
1283                                                     &lowpan_enable_fops);
1284         lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644,
1285                                                      bt_debugfs, NULL,
1286                                                      &lowpan_control_fops);
1287 
1288         return register_netdevice_notifier(&bt_6lowpan_dev_notifier);
1289 }
1290 
1291 static void __exit bt_6lowpan_exit(void)
1292 {
1293         debugfs_remove(lowpan_enable_debugfs);
1294         debugfs_remove(lowpan_control_debugfs);
1295 
1296         if (listen_chan) {
1297                 l2cap_chan_close(listen_chan, 0);
1298                 l2cap_chan_put(listen_chan);
1299         }
1300 
1301         disconnect_devices();
1302 
1303         unregister_netdevice_notifier(&bt_6lowpan_dev_notifier);
1304 }
1305 
1306 module_init(bt_6lowpan_init);
1307 module_exit(bt_6lowpan_exit);
1308 
1309 MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>");
1310 MODULE_DESCRIPTION("Bluetooth 6LoWPAN");
1311 MODULE_VERSION(VERSION);
1312 MODULE_LICENSE("GPL");
1313 

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