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                 if (ipv6_addr_any(&lowpan_cb(skb)->gw)) {
 191                         /* There is neither route nor gateway,
 192                          * probably the destination is a direct peer.
 193                          */
 194                         nexthop = daddr;
 195                 } else {
 196                         /* There is a known gateway
 197                          */
 198                         nexthop = &lowpan_cb(skb)->gw;
 199                 }
 200         } else {
 201                 nexthop = rt6_nexthop(rt, daddr);
 202
 203                 /* We need to remember the address because it is needed
 204                  * by bt_xmit() when sending the packet. In bt_xmit(), the
 205                  * destination routing info is not set.
 206                  */
 207                 memcpy(&lowpan_cb(skb)->gw, nexthop, sizeof(struct in6_addr));
 208         }
 209
 210         BT_DBG("gw %pI6c", nexthop);
 211
 212         rcu_read_lock();
 213
 214         list_for_each_entry_rcu(peer, &dev->peers, list) {
 215                 BT_DBG("dst addr %pMR dst type %d ip %pI6c",
 216                        &peer->chan->dst, peer->chan->dst_type,
 217                        &peer->peer_addr);
 218
 219                 if (!ipv6_addr_cmp(&peer->peer_addr, nexthop)) {
 220                         rcu_read_unlock();
 221                         return peer;
 222                 }
 223         }
 224
 225         rcu_read_unlock();
 226
 227         return NULL;
 228 }
 229
 230 static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn)
 231 {
 232         struct lowpan_btle_dev *entry;
 233         struct lowpan_peer *peer = NULL;
 234
 235         rcu_read_lock();
 236
 237         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 238                 peer = __peer_lookup_conn(entry, conn);
 239                 if (peer)
 240                         break;
 241         }
 242
 243         rcu_read_unlock();
 244
 245         return peer;
 246 }
 247
 248 static struct lowpan_btle_dev *lookup_dev(struct l2cap_conn *conn)
 249 {
 250         struct lowpan_btle_dev *entry;
 251         struct lowpan_btle_dev *dev = NULL;
 252
 253         rcu_read_lock();
 254
 255         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 256                 if (conn->hcon->hdev == entry->hdev) {
 257                         dev = entry;
 258                         break;
 259                 }
 260         }
 261
 262         rcu_read_unlock();
 263
 264         return dev;
 265 }
 266
 267 static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev)
 268 {
 269         struct sk_buff *skb_cp;
 270
 271         skb_cp = skb_copy(skb, GFP_ATOMIC);
 272         if (!skb_cp)
 273                 return NET_RX_DROP;
 274
 275         return netif_rx_ni(skb_cp);
 276 }
 277
 278 static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev,
 279                            struct lowpan_peer *peer)
 280 {
 281         const u8 *saddr;
 282
 283         saddr = peer->lladdr;
 284
 285         return lowpan_header_decompress(skb, netdev, netdev->dev_addr, saddr);
 286 }
 287
 288 static int recv_pkt(struct sk_buff *skb, struct net_device *dev,
 289                     struct lowpan_peer *peer)
 290 {
 291         struct sk_buff *local_skb;
 292         int ret;
 293
 294         if (!netif_running(dev))
 295                 goto drop;
 296
 297         if (dev->type != ARPHRD_6LOWPAN || !skb->len)
 298                 goto drop;
 299
 300         skb_reset_network_header(skb);
 301
 302         skb = skb_share_check(skb, GFP_ATOMIC);
 303         if (!skb)
 304                 goto drop;
 305
 306         /* check that it's our buffer */
 307         if (lowpan_is_ipv6(*skb_network_header(skb))) {
 308                 /* Pull off the 1-byte of 6lowpan header. */
 309                 skb_pull(skb, 1);
 310
 311                 /* Copy the packet so that the IPv6 header is
 312                  * properly aligned.
 313                  */
 314                 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
 315                                             skb_tailroom(skb), GFP_ATOMIC);
 316                 if (!local_skb)
 317                         goto drop;
 318
 319                 local_skb->protocol = htons(ETH_P_IPV6);
 320                 local_skb->pkt_type = PACKET_HOST;
 321                 local_skb->dev = dev;
 322
 323                 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
 324
 325                 if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) {
 326                         kfree_skb(local_skb);
 327                         goto drop;
 328                 }
 329
 330                 dev->stats.rx_bytes += skb->len;
 331                 dev->stats.rx_packets++;
 332
 333                 consume_skb(local_skb);
 334                 consume_skb(skb);
 335         } else if (lowpan_is_iphc(*skb_network_header(skb))) {
 336                 local_skb = skb_clone(skb, GFP_ATOMIC);
 337                 if (!local_skb)
 338                         goto drop;
 339
 340                 local_skb->dev = dev;
 341
 342                 ret = iphc_decompress(local_skb, dev, peer);
 343                 if (ret < 0) {
 344                         BT_DBG("iphc_decompress failed: %d", ret);
 345                         kfree_skb(local_skb);
 346                         goto drop;
 347                 }
 348
 349                 local_skb->protocol = htons(ETH_P_IPV6);
 350                 local_skb->pkt_type = PACKET_HOST;
 351
 352                 if (give_skb_to_upper(local_skb, dev)
 353                                 != NET_RX_SUCCESS) {
 354                         kfree_skb(local_skb);
 355                         goto drop;
 356                 }
 357
 358                 dev->stats.rx_bytes += skb->len;
 359                 dev->stats.rx_packets++;
 360
 361                 consume_skb(local_skb);
 362                 consume_skb(skb);
 363         } else {
 364                 BT_DBG("unknown packet type");
 365                 goto drop;
 366         }
 367
 368         return NET_RX_SUCCESS;
 369
 370 drop:
 371         dev->stats.rx_dropped++;
 372         return NET_RX_DROP;
 373 }
 374
 375 /* Packet from BT LE device */
 376 static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
 377 {
 378         struct lowpan_btle_dev *dev;
 379         struct lowpan_peer *peer;
 380         int err;
 381
 382         peer = lookup_peer(chan->conn);
 383         if (!peer)
 384                 return -ENOENT;
 385
 386         dev = lookup_dev(chan->conn);
 387         if (!dev || !dev->netdev)
 388                 return -ENOENT;
 389
 390         err = recv_pkt(skb, dev->netdev, peer);
 391         if (err) {
 392                 BT_DBG("recv pkt %d", err);
 393                 err = -EAGAIN;
 394         }
 395
 396         return err;
 397 }
 398
 399 static int setup_header(struct sk_buff *skb, struct net_device *netdev,
 400                         bdaddr_t *peer_addr, u8 *peer_addr_type)
 401 {
 402         struct in6_addr ipv6_daddr;
 403         struct ipv6hdr *hdr;
 404         struct lowpan_btle_dev *dev;
 405         struct lowpan_peer *peer;
 406         u8 *daddr;
 407         int err, status = 0;
 408
 409         hdr = ipv6_hdr(skb);
 410
 411         dev = lowpan_btle_dev(netdev);
 412
 413         memcpy(&ipv6_daddr, &hdr->daddr, sizeof(ipv6_daddr));
 414
 415         if (ipv6_addr_is_multicast(&ipv6_daddr)) {
 416                 lowpan_cb(skb)->chan = NULL;
 417                 daddr = NULL;
 418         } else {
 419                 BT_DBG("dest IP %pI6c", &ipv6_daddr);
 420
 421                 /* The packet might be sent to 6lowpan interface
 422                  * because of routing (either via default route
 423                  * or user set route) so get peer according to
 424                  * the destination address.
 425                  */
 426                 peer = peer_lookup_dst(dev, &ipv6_daddr, skb);
 427                 if (!peer) {
 428                         BT_DBG("no such peer");
 429                         return -ENOENT;
 430                 }
 431
 432                 daddr = peer->lladdr;
 433                 *peer_addr = peer->chan->dst;
 434                 *peer_addr_type = peer->chan->dst_type;
 435                 lowpan_cb(skb)->chan = peer->chan;
 436
 437                 status = 1;
 438         }
 439
 440         lowpan_header_compress(skb, netdev, daddr, dev->netdev->dev_addr);
 441
 442         err = dev_hard_header(skb, netdev, ETH_P_IPV6, NULL, NULL, 0);
 443         if (err < 0)
 444                 return err;
 445
 446         return status;
 447 }
 448
 449 static int header_create(struct sk_buff *skb, struct net_device *netdev,
 450                          unsigned short type, const void *_daddr,
 451                          const void *_saddr, unsigned int len)
 452 {
 453         if (type != ETH_P_IPV6)
 454                 return -EINVAL;
 455
 456         return 0;
 457 }
 458
 459 /* Packet to BT LE device */
 460 static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb,
 461                     struct net_device *netdev)
 462 {
 463         struct msghdr msg;
 464         struct kvec iv;
 465         int err;
 466
 467         /* Remember the skb so that we can send EAGAIN to the caller if
 468          * we run out of credits.
 469          */
 470         chan->data = skb;
 471
 472         iv.iov_base = skb->data;
 473         iv.iov_len = skb->len;
 474
 475         memset(&msg, 0, sizeof(msg));
 476         iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, &iv, 1, skb->len);
 477
 478         err = l2cap_chan_send(chan, &msg, skb->len);
 479         if (err > 0) {
 480                 netdev->stats.tx_bytes += err;
 481                 netdev->stats.tx_packets++;
 482                 return 0;
 483         }
 484
 485         if (err < 0)
 486                 netdev->stats.tx_errors++;
 487
 488         return err;
 489 }
 490
 491 static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev)
 492 {
 493         struct sk_buff *local_skb;
 494         struct lowpan_btle_dev *entry;
 495         int err = 0;
 496
 497         rcu_read_lock();
 498
 499         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 500                 struct lowpan_peer *pentry;
 501                 struct lowpan_btle_dev *dev;
 502
 503                 if (entry->netdev != netdev)
 504                         continue;
 505
 506                 dev = lowpan_btle_dev(entry->netdev);
 507
 508                 list_for_each_entry_rcu(pentry, &dev->peers, list) {
 509                         int ret;
 510
 511                         local_skb = skb_clone(skb, GFP_ATOMIC);
 512
 513                         BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
 514                                netdev->name,
 515                                &pentry->chan->dst, pentry->chan->dst_type,
 516                                &pentry->peer_addr, pentry->chan);
 517                         ret = send_pkt(pentry->chan, local_skb, netdev);
 518                         if (ret < 0)
 519                                 err = ret;
 520
 521                         kfree_skb(local_skb);
 522                 }
 523         }
 524
 525         rcu_read_unlock();
 526
 527         return err;
 528 }
 529
 530 static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev)
 531 {
 532         int err = 0;
 533         bdaddr_t addr;
 534         u8 addr_type;
 535
 536         /* We must take a copy of the skb before we modify/replace the ipv6
 537          * header as the header could be used elsewhere
 538          */
 539         skb = skb_unshare(skb, GFP_ATOMIC);
 540         if (!skb)
 541                 return NET_XMIT_DROP;
 542
 543         /* Return values from setup_header()
 544          *  <0 - error, packet is dropped
 545          *   0 - this is a multicast packet
 546          *   1 - this is unicast packet
 547          */
 548         err = setup_header(skb, netdev, &addr, &addr_type);
 549         if (err < 0) {
 550                 kfree_skb(skb);
 551                 return NET_XMIT_DROP;
 552         }
 553
 554         if (err) {
 555                 if (lowpan_cb(skb)->chan) {
 556                         BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
 557                                netdev->name, &addr, addr_type,
 558                                &lowpan_cb(skb)->addr, lowpan_cb(skb)->chan);
 559                         err = send_pkt(lowpan_cb(skb)->chan, skb, netdev);
 560                 } else {
 561                         err = -ENOENT;
 562                 }
 563         } else {
 564                 /* We need to send the packet to every device behind this
 565                  * interface.
 566                  */
 567                 err = send_mcast_pkt(skb, netdev);
 568         }
 569
 570         dev_kfree_skb(skb);
 571
 572         if (err)
 573                 BT_DBG("ERROR: xmit failed (%d)", err);
 574
 575         return err < 0 ? NET_XMIT_DROP : err;
 576 }
 577
 578 static int bt_dev_init(struct net_device *dev)
 579 {
 580         netdev_lockdep_set_classes(dev);
 581
 582         return 0;
 583 }
 584
 585 static const struct net_device_ops netdev_ops = {
 586         .ndo_init               = bt_dev_init,
 587         .ndo_start_xmit         = bt_xmit,
 588 };
 589
 590 static struct header_ops header_ops = {
 591         .create = header_create,
 592 };
 593
 594 static void netdev_setup(struct net_device *dev)
 595 {
 596         dev->hard_header_len    = 0;
 597         dev->needed_tailroom    = 0;
 598         dev->flags              = IFF_RUNNING | IFF_MULTICAST;
 599         dev->watchdog_timeo     = 0;
 600         dev->tx_queue_len       = DEFAULT_TX_QUEUE_LEN;
 601
 602         dev->netdev_ops         = &netdev_ops;
 603         dev->header_ops         = &header_ops;
 604         dev->needs_free_netdev  = true;
 605 }
 606
 607 static struct device_type bt_type = {
 608         .name   = "bluetooth",
 609 };
 610
 611 static void ifup(struct net_device *netdev)
 612 {
 613         int err;
 614
 615         rtnl_lock();
 616         err = dev_open(netdev);
 617         if (err < 0)
 618                 BT_INFO("iface %s cannot be opened (%d)", netdev->name, err);
 619         rtnl_unlock();
 620 }
 621
 622 static void ifdown(struct net_device *netdev)
 623 {
 624         rtnl_lock();
 625         dev_close(netdev);
 626         rtnl_unlock();
 627 }
 628
 629 static void do_notify_peers(struct work_struct *work)
 630 {
 631         struct lowpan_btle_dev *dev = container_of(work, struct lowpan_btle_dev,
 632                                                    notify_peers.work);
 633
 634         netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */
 635 }
 636
 637 static bool is_bt_6lowpan(struct hci_conn *hcon)
 638 {
 639         if (hcon->type != LE_LINK)
 640                 return false;
 641
 642         if (!enable_6lowpan)
 643                 return false;
 644
 645         return true;
 646 }
 647
 648 static struct l2cap_chan *chan_create(void)
 649 {
 650         struct l2cap_chan *chan;
 651
 652         chan = l2cap_chan_create();
 653         if (!chan)
 654                 return NULL;
 655
 656         l2cap_chan_set_defaults(chan);
 657
 658         chan->chan_type = L2CAP_CHAN_CONN_ORIENTED;
 659         chan->mode = L2CAP_MODE_LE_FLOWCTL;
 660         chan->imtu = 1280;
 661
 662         return chan;
 663 }
 664
 665 static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan,
 666                                         struct lowpan_btle_dev *dev,
 667                                         bool new_netdev)
 668 {
 669         struct lowpan_peer *peer;
 670
 671         peer = kzalloc(sizeof(*peer), GFP_ATOMIC);
 672         if (!peer)
 673                 return NULL;
 674
 675         peer->chan = chan;
 676         memset(&peer->peer_addr, 0, sizeof(struct in6_addr));
 677
 678         baswap((void *)peer->lladdr, &chan->dst);
 679
 680         lowpan_iphc_uncompress_eui48_lladdr(&peer->peer_addr, peer->lladdr);
 681
 682         spin_lock(&devices_lock);
 683         INIT_LIST_HEAD(&peer->list);
 684         peer_add(dev, peer);
 685         spin_unlock(&devices_lock);
 686
 687         /* Notifying peers about us needs to be done without locks held */
 688         if (new_netdev)
 689                 INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers);
 690         schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100));
 691
 692         return peer->chan;
 693 }
 694
 695 static int setup_netdev(struct l2cap_chan *chan, struct lowpan_btle_dev **dev)
 696 {
 697         struct net_device *netdev;
 698         int err = 0;
 699
 700         netdev = alloc_netdev(LOWPAN_PRIV_SIZE(sizeof(struct lowpan_btle_dev)),
 701                               IFACE_NAME_TEMPLATE, NET_NAME_UNKNOWN,
 702                               netdev_setup);
 703         if (!netdev)
 704                 return -ENOMEM;
 705
 706         netdev->addr_assign_type = NET_ADDR_PERM;
 707         baswap((void *)netdev->dev_addr, &chan->src);
 708
 709         netdev->netdev_ops = &netdev_ops;
 710         SET_NETDEV_DEV(netdev, &chan->conn->hcon->hdev->dev);
 711         SET_NETDEV_DEVTYPE(netdev, &bt_type);
 712
 713         *dev = lowpan_btle_dev(netdev);
 714         (*dev)->netdev = netdev;
 715         (*dev)->hdev = chan->conn->hcon->hdev;
 716         INIT_LIST_HEAD(&(*dev)->peers);
 717
 718         spin_lock(&devices_lock);
 719         INIT_LIST_HEAD(&(*dev)->list);
 720         list_add_rcu(&(*dev)->list, &bt_6lowpan_devices);
 721         spin_unlock(&devices_lock);
 722
 723         err = lowpan_register_netdev(netdev, LOWPAN_LLTYPE_BTLE);
 724         if (err < 0) {
 725                 BT_INFO("register_netdev failed %d", err);
 726                 spin_lock(&devices_lock);
 727                 list_del_rcu(&(*dev)->list);
 728                 spin_unlock(&devices_lock);
 729                 free_netdev(netdev);
 730                 goto out;
 731         }
 732
 733         BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d",
 734                netdev->ifindex, &chan->dst, chan->dst_type,
 735                &chan->src, chan->src_type);
 736         set_bit(__LINK_STATE_PRESENT, &netdev->state);
 737
 738         return 0;
 739
 740 out:
 741         return err;
 742 }
 743
 744 static inline void chan_ready_cb(struct l2cap_chan *chan)
 745 {
 746         struct lowpan_btle_dev *dev;
 747         bool new_netdev = false;
 748
 749         dev = lookup_dev(chan->conn);
 750
 751         BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev);
 752
 753         if (!dev) {
 754                 if (setup_netdev(chan, &dev) < 0) {
 755                         l2cap_chan_del(chan, -ENOENT);
 756                         return;
 757                 }
 758                 new_netdev = true;
 759         }
 760
 761         if (!try_module_get(THIS_MODULE))
 762                 return;
 763
 764         add_peer_chan(chan, dev, new_netdev);
 765         ifup(dev->netdev);
 766 }
 767
 768 static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan)
 769 {
 770         struct l2cap_chan *chan;
 771
 772         chan = chan_create();
 773         if (!chan)
 774                 return NULL;
 775
 776         chan->ops = pchan->ops;
 777
 778         BT_DBG("chan %p pchan %p", chan, pchan);
 779
 780         return chan;
 781 }
 782
 783 static void delete_netdev(struct work_struct *work)
 784 {
 785         struct lowpan_btle_dev *entry = container_of(work,
 786                                                      struct lowpan_btle_dev,
 787                                                      delete_netdev);
 788
 789         lowpan_unregister_netdev(entry->netdev);
 790
 791         /* The entry pointer is deleted by the netdev destructor. */
 792 }
 793
 794 static void chan_close_cb(struct l2cap_chan *chan)
 795 {
 796         struct lowpan_btle_dev *entry;
 797         struct lowpan_btle_dev *dev = NULL;
 798         struct lowpan_peer *peer;
 799         int err = -ENOENT;
 800         bool last = false, remove = true;
 801
 802         BT_DBG("chan %p conn %p", chan, chan->conn);
 803
 804         if (chan->conn && chan->conn->hcon) {
 805                 if (!is_bt_6lowpan(chan->conn->hcon))
 806                         return;
 807
 808                 /* If conn is set, then the netdev is also there and we should
 809                  * not remove it.
 810                  */
 811                 remove = false;
 812         }
 813
 814         spin_lock(&devices_lock);
 815
 816         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 817                 dev = lowpan_btle_dev(entry->netdev);
 818                 peer = __peer_lookup_chan(dev, chan);
 819                 if (peer) {
 820                         last = peer_del(dev, peer);
 821                         err = 0;
 822
 823                         BT_DBG("dev %p removing %speer %p", dev,
 824                                last ? "last " : "1 ", peer);
 825                         BT_DBG("chan %p orig refcnt %d", chan,
 826                                kref_read(&chan->kref));
 827
 828                         l2cap_chan_put(chan);
 829                         break;
 830                 }
 831         }
 832
 833         if (!err && last && dev && !atomic_read(&dev->peer_count)) {
 834                 spin_unlock(&devices_lock);
 835
 836                 cancel_delayed_work_sync(&dev->notify_peers);
 837
 838                 ifdown(dev->netdev);
 839
 840                 if (remove) {
 841                         INIT_WORK(&entry->delete_netdev, delete_netdev);
 842                         schedule_work(&entry->delete_netdev);
 843                 }
 844         } else {
 845                 spin_unlock(&devices_lock);
 846         }
 847
 848         return;
 849 }
 850
 851 static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err)
 852 {
 853         BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn,
 854                state_to_string(state), err);
 855 }
 856
 857 static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan,
 858                                          unsigned long hdr_len,
 859                                          unsigned long len, int nb)
 860 {
 861         /* Note that we must allocate using GFP_ATOMIC here as
 862          * this function is called originally from netdev hard xmit
 863          * function in atomic context.
 864          */
 865         return bt_skb_alloc(hdr_len + len, GFP_ATOMIC);
 866 }
 867
 868 static void chan_suspend_cb(struct l2cap_chan *chan)
 869 {
 870         struct lowpan_btle_dev *dev;
 871
 872         BT_DBG("chan %p suspend", chan);
 873
 874         dev = lookup_dev(chan->conn);
 875         if (!dev || !dev->netdev)
 876                 return;
 877
 878         netif_stop_queue(dev->netdev);
 879 }
 880
 881 static void chan_resume_cb(struct l2cap_chan *chan)
 882 {
 883         struct lowpan_btle_dev *dev;
 884
 885         BT_DBG("chan %p resume", chan);
 886
 887         dev = lookup_dev(chan->conn);
 888         if (!dev || !dev->netdev)
 889                 return;
 890
 891         netif_wake_queue(dev->netdev);
 892 }
 893
 894 static long chan_get_sndtimeo_cb(struct l2cap_chan *chan)
 895 {
 896         return L2CAP_CONN_TIMEOUT;
 897 }
 898
 899 static const struct l2cap_ops bt_6lowpan_chan_ops = {
 900         .name                   = "L2CAP 6LoWPAN channel",
 901         .new_connection         = chan_new_conn_cb,
 902         .recv                   = chan_recv_cb,
 903         .close                  = chan_close_cb,
 904         .state_change           = chan_state_change_cb,
 905         .ready                  = chan_ready_cb,
 906         .resume                 = chan_resume_cb,
 907         .suspend                = chan_suspend_cb,
 908         .get_sndtimeo           = chan_get_sndtimeo_cb,
 909         .alloc_skb              = chan_alloc_skb_cb,
 910
 911         .teardown               = l2cap_chan_no_teardown,
 912         .defer                  = l2cap_chan_no_defer,
 913         .set_shutdown           = l2cap_chan_no_set_shutdown,
 914 };
 915
 916 static inline __u8 bdaddr_type(__u8 type)
 917 {
 918         if (type == ADDR_LE_DEV_PUBLIC)
 919                 return BDADDR_LE_PUBLIC;
 920         else
 921                 return BDADDR_LE_RANDOM;
 922 }
 923
 924 static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type)
 925 {
 926         struct l2cap_chan *chan;
 927         int err;
 928
 929         chan = chan_create();
 930         if (!chan)
 931                 return -EINVAL;
 932
 933         chan->ops = &bt_6lowpan_chan_ops;
 934
 935         err = l2cap_chan_connect(chan, cpu_to_le16(L2CAP_PSM_IPSP), 0,
 936                                  addr, dst_type);
 937
 938         BT_DBG("chan %p err %d", chan, err);
 939         if (err < 0)
 940                 l2cap_chan_put(chan);
 941
 942         return err;
 943 }
 944
 945 static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type)
 946 {
 947         struct lowpan_peer *peer;
 948
 949         BT_DBG("conn %p dst type %d", conn, dst_type);
 950
 951         peer = lookup_peer(conn);
 952         if (!peer)
 953                 return -ENOENT;
 954
 955         BT_DBG("peer %p chan %p", peer, peer->chan);
 956
 957         l2cap_chan_close(peer->chan, ENOENT);
 958
 959         return 0;
 960 }
 961
 962 static struct l2cap_chan *bt_6lowpan_listen(void)
 963 {
 964         bdaddr_t *addr = BDADDR_ANY;
 965         struct l2cap_chan *chan;
 966         int err;
 967
 968         if (!enable_6lowpan)
 969                 return NULL;
 970
 971         chan = chan_create();
 972         if (!chan)
 973                 return NULL;
 974
 975         chan->ops = &bt_6lowpan_chan_ops;
 976         chan->state = BT_LISTEN;
 977         chan->src_type = BDADDR_LE_PUBLIC;
 978
 979         atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
 980
 981         BT_DBG("chan %p src type %d", chan, chan->src_type);
 982
 983         err = l2cap_add_psm(chan, addr, cpu_to_le16(L2CAP_PSM_IPSP));
 984         if (err) {
 985                 l2cap_chan_put(chan);
 986                 BT_ERR("psm cannot be added err %d", err);
 987                 return NULL;
 988         }
 989
 990         return chan;
 991 }
 992
 993 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type,
 994                           struct l2cap_conn **conn)
 995 {
 996         struct hci_conn *hcon;
 997         struct hci_dev *hdev;
 998         int n;
 999
1000         n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu",
1001                    &addr->b[5], &addr->b[4], &addr->b[3],
1002                    &addr->b[2], &addr->b[1], &addr->b[0],
1003                    addr_type);
1004
1005         if (n < 7)
1006                 return -EINVAL;
1007
1008         /* The LE_PUBLIC address type is ignored because of BDADDR_ANY */
1009         hdev = hci_get_route(addr, BDADDR_ANY, BDADDR_LE_PUBLIC);
1010         if (!hdev)
1011                 return -ENOENT;
1012
1013         hci_dev_lock(hdev);
1014         hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type);
1015         hci_dev_unlock(hdev);
1016
1017         if (!hcon)
1018                 return -ENOENT;
1019
1020         *conn = (struct l2cap_conn *)hcon->l2cap_data;
1021
1022         BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type);
1023
1024         return 0;
1025 }
1026
1027 static void disconnect_all_peers(void)
1028 {
1029         struct lowpan_btle_dev *entry;
1030         struct lowpan_peer *peer, *tmp_peer, *new_peer;
1031         struct list_head peers;
1032
1033         INIT_LIST_HEAD(&peers);
1034
1035         /* We make a separate list of peers as the close_cb() will
1036          * modify the device peers list so it is better not to mess
1037          * with the same list at the same time.
1038          */
1039
1040         rcu_read_lock();
1041
1042         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1043                 list_for_each_entry_rcu(peer, &entry->peers, list) {
1044                         new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC);
1045                         if (!new_peer)
1046                                 break;
1047
1048                         new_peer->chan = peer->chan;
1049                         INIT_LIST_HEAD(&new_peer->list);
1050
1051                         list_add(&new_peer->list, &peers);
1052                 }
1053         }
1054
1055         rcu_read_unlock();
1056
1057         spin_lock(&devices_lock);
1058         list_for_each_entry_safe(peer, tmp_peer, &peers, list) {
1059                 l2cap_chan_close(peer->chan, ENOENT);
1060
1061                 list_del_rcu(&peer->list);
1062                 kfree_rcu(peer, rcu);
1063         }
1064         spin_unlock(&devices_lock);
1065 }
1066
1067 struct set_enable {
1068         struct work_struct work;
1069         bool flag;
1070 };
1071
1072 static void do_enable_set(struct work_struct *work)
1073 {
1074         struct set_enable *set_enable = container_of(work,
1075                                                      struct set_enable, work);
1076
1077         if (!set_enable->flag || enable_6lowpan != set_enable->flag)
1078                 /* Disconnect existing connections if 6lowpan is
1079                  * disabled
1080                  */
1081                 disconnect_all_peers();
1082
1083         enable_6lowpan = set_enable->flag;
1084
1085         if (listen_chan) {
1086                 l2cap_chan_close(listen_chan, 0);
1087                 l2cap_chan_put(listen_chan);
1088         }
1089
1090         listen_chan = bt_6lowpan_listen();
1091
1092         kfree(set_enable);
1093 }
1094
1095 static int lowpan_enable_set(void *data, u64 val)
1096 {
1097         struct set_enable *set_enable;
1098
1099         set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL);
1100         if (!set_enable)
1101                 return -ENOMEM;
1102
1103         set_enable->flag = !!val;
1104         INIT_WORK(&set_enable->work, do_enable_set);
1105
1106         schedule_work(&set_enable->work);
1107
1108         return 0;
1109 }
1110
1111 static int lowpan_enable_get(void *data, u64 *val)
1112 {
1113         *val = enable_6lowpan;
1114         return 0;
1115 }
1116
1117 DEFINE_SIMPLE_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get,
1118                         lowpan_enable_set, "%llu\n");
1119
1120 static ssize_t lowpan_control_write(struct file *fp,
1121                                     const char __user *user_buffer,
1122                                     size_t count,
1123                                     loff_t *position)
1124 {
1125         char buf[32];
1126         size_t buf_size = min(count, sizeof(buf) - 1);
1127         int ret;
1128         bdaddr_t addr;
1129         u8 addr_type;
1130         struct l2cap_conn *conn = NULL;
1131
1132         if (copy_from_user(buf, user_buffer, buf_size))
1133                 return -EFAULT;
1134
1135         buf[buf_size] = '\0';
1136
1137         if (memcmp(buf, "connect ", 8) == 0) {
1138                 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn);
1139                 if (ret == -EINVAL)
1140                         return ret;
1141
1142                 if (listen_chan) {
1143                         l2cap_chan_close(listen_chan, 0);
1144                         l2cap_chan_put(listen_chan);
1145                         listen_chan = NULL;
1146                 }
1147
1148                 if (conn) {
1149                         struct lowpan_peer *peer;
1150
1151                         if (!is_bt_6lowpan(conn->hcon))
1152                                 return -EINVAL;
1153
1154                         peer = lookup_peer(conn);
1155                         if (peer) {
1156                                 BT_DBG("6LoWPAN connection already exists");
1157                                 return -EALREADY;
1158                         }
1159
1160                         BT_DBG("conn %p dst %pMR type %d user %d", conn,
1161                                &conn->hcon->dst, conn->hcon->dst_type,
1162                                addr_type);
1163                 }
1164
1165                 ret = bt_6lowpan_connect(&addr, addr_type);
1166                 if (ret < 0)
1167                         return ret;
1168
1169                 return count;
1170         }
1171
1172         if (memcmp(buf, "disconnect ", 11) == 0) {
1173                 ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn);
1174                 if (ret < 0)
1175                         return ret;
1176
1177                 ret = bt_6lowpan_disconnect(conn, addr_type);
1178                 if (ret < 0)
1179                         return ret;
1180
1181                 return count;
1182         }
1183
1184         return count;
1185 }
1186
1187 static int lowpan_control_show(struct seq_file *f, void *ptr)
1188 {
1189         struct lowpan_btle_dev *entry;
1190         struct lowpan_peer *peer;
1191
1192         spin_lock(&devices_lock);
1193
1194         list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1195                 list_for_each_entry(peer, &entry->peers, list)
1196                         seq_printf(f, "%pMR (type %u)\n",
1197                                    &peer->chan->dst, peer->chan->dst_type);
1198         }
1199
1200         spin_unlock(&devices_lock);
1201
1202         return 0;
1203 }
1204
1205 static int lowpan_control_open(struct inode *inode, struct file *file)
1206 {
1207         return single_open(file, lowpan_control_show, inode->i_private);
1208 }
1209
1210 static const struct file_operations lowpan_control_fops = {
1211         .open           = lowpan_control_open,
1212         .read           = seq_read,
1213         .write          = lowpan_control_write,
1214         .llseek         = seq_lseek,
1215         .release        = single_release,
1216 };
1217
1218 static void disconnect_devices(void)
1219 {
1220         struct lowpan_btle_dev *entry, *tmp, *new_dev;
1221         struct list_head devices;
1222
1223         INIT_LIST_HEAD(&devices);
1224
1225         /* We make a separate list of devices because the unregister_netdev()
1226          * will call device_event() which will also want to modify the same
1227          * devices list.
1228          */
1229
1230         rcu_read_lock();
1231
1232         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1233                 new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC);
1234                 if (!new_dev)
1235                         break;
1236
1237                 new_dev->netdev = entry->netdev;
1238                 INIT_LIST_HEAD(&new_dev->list);
1239
1240                 list_add_rcu(&new_dev->list, &devices);
1241         }
1242
1243         rcu_read_unlock();
1244
1245         list_for_each_entry_safe(entry, tmp, &devices, list) {
1246                 ifdown(entry->netdev);
1247                 BT_DBG("Unregistering netdev %s %p",
1248                        entry->netdev->name, entry->netdev);
1249                 lowpan_unregister_netdev(entry->netdev);
1250                 kfree(entry);
1251         }
1252 }
1253
1254 static int device_event(struct notifier_block *unused,
1255                         unsigned long event, void *ptr)
1256 {
1257         struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
1258         struct lowpan_btle_dev *entry;
1259
1260         if (netdev->type != ARPHRD_6LOWPAN)
1261                 return NOTIFY_DONE;
1262
1263         switch (event) {
1264         case NETDEV_UNREGISTER:
1265                 spin_lock(&devices_lock);
1266                 list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1267                         if (entry->netdev == netdev) {
1268                                 BT_DBG("Unregistered netdev %s %p",
1269                                        netdev->name, netdev);
1270                                 list_del(&entry->list);
1271                                 break;
1272                         }
1273                 }
1274                 spin_unlock(&devices_lock);
1275                 break;
1276         }
1277
1278         return NOTIFY_DONE;
1279 }
1280
1281 static struct notifier_block bt_6lowpan_dev_notifier = {
1282         .notifier_call = device_event,
1283 };
1284
1285 static int __init bt_6lowpan_init(void)
1286 {
1287         lowpan_enable_debugfs = debugfs_create_file("6lowpan_enable", 0644,
1288                                                     bt_debugfs, NULL,
1289                                                     &lowpan_enable_fops);
1290         lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644,
1291                                                      bt_debugfs, NULL,
1292                                                      &lowpan_control_fops);
1293
1294         return register_netdevice_notifier(&bt_6lowpan_dev_notifier);
1295 }
1296
1297 static void __exit bt_6lowpan_exit(void)
1298 {
1299         debugfs_remove(lowpan_enable_debugfs);
1300         debugfs_remove(lowpan_control_debugfs);
1301
1302         if (listen_chan) {
1303                 l2cap_chan_close(listen_chan, 0);
1304                 l2cap_chan_put(listen_chan);
1305         }
1306
1307         disconnect_devices();
1308
1309         unregister_netdevice_notifier(&bt_6lowpan_dev_notifier);
1310 }
1311
1312 module_init(bt_6lowpan_init);
1313 module_exit(bt_6lowpan_exit);
1314
1315 MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>");
1316 MODULE_DESCRIPTION("Bluetooth 6LoWPAN");
1317 MODULE_VERSION(VERSION);
1318 MODULE_LICENSE("GPL");