net/bluetooth/6lowpan.c

   1 /*
   2    Copyright (c) 2013-2014 Intel Corp.
   3
   4    This program is free software; you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License version 2 and
   6    only version 2 as published by the Free Software Foundation.
   7
   8    This program is distributed in the hope that it will be useful,
   9    but WITHOUT ANY WARRANTY; without even the implied warranty of
  10    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11    GNU General Public License for more details.
  12 */
  13
  14 #include <linux/if_arp.h>
  15 #include <linux/netdevice.h>
  16 #include <linux/etherdevice.h>
  17 #include <linux/module.h>
  18 #include <linux/debugfs.h>
  19
  20 #include <net/ipv6.h>
  21 #include <net/ip6_route.h>
  22 #include <net/addrconf.h>
  23 #include <net/pkt_sched.h>
  24
  25 #include <net/bluetooth/bluetooth.h>
  26 #include <net/bluetooth/hci_core.h>
  27 #include <net/bluetooth/l2cap.h>
  28
  29 #include <net/6lowpan.h> /* for the compression support */
  30
  31 #define VERSION "0.1"
  32
  33 static struct dentry *lowpan_enable_debugfs;
  34 static struct dentry *lowpan_control_debugfs;
  35
  36 #define IFACE_NAME_TEMPLATE "bt%d"
  37
  38 struct skb_cb {
  39         struct in6_addr addr;
  40         struct in6_addr gw;
  41         struct l2cap_chan *chan;
  42 };
  43 #define lowpan_cb(skb) ((struct skb_cb *)((skb)->cb))
  44
  45 /* The devices list contains those devices that we are acting
  46  * as a proxy. The BT 6LoWPAN device is a virtual device that
  47  * connects to the Bluetooth LE device. The real connection to
  48  * BT device is done via l2cap layer. There exists one
  49  * virtual device / one BT 6LoWPAN network (=hciX device).
  50  * The list contains struct lowpan_dev elements.
  51  */
  52 static LIST_HEAD(bt_6lowpan_devices);
  53 static DEFINE_SPINLOCK(devices_lock);
  54
  55 static bool enable_6lowpan;
  56
  57 /* We are listening incoming connections via this channel
  58  */
  59 static struct l2cap_chan *listen_chan;
  60
  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 | ITER_KVEC, &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");