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 static DEFINE_MUTEX(set_lock);
  61
  62 struct lowpan_peer {
  63         struct list_head list;
  64         struct rcu_head rcu;
  65         struct l2cap_chan *chan;
  66
  67         /* peer addresses in various formats */
  68         unsigned char lladdr[ETH_ALEN];
  69         struct in6_addr peer_addr;
  70 };
  71
  72 struct lowpan_btle_dev {
  73         struct list_head list;
  74
  75         struct hci_dev *hdev;
  76         struct net_device *netdev;
  77         struct list_head peers;
  78         atomic_t peer_count; /* number of items in peers list */
  79
  80         struct work_struct delete_netdev;
  81         struct delayed_work notify_peers;
  82 };
  83
  84 static inline struct lowpan_btle_dev *
  85 lowpan_btle_dev(const struct net_device *netdev)
  86 {
  87         return (struct lowpan_btle_dev *)lowpan_dev(netdev)->priv;
  88 }
  89
  90 static inline void peer_add(struct lowpan_btle_dev *dev,
  91                             struct lowpan_peer *peer)
  92 {
  93         list_add_rcu(&peer->list, &dev->peers);
  94         atomic_inc(&dev->peer_count);
  95 }
  96
  97 static inline bool peer_del(struct lowpan_btle_dev *dev,
  98                             struct lowpan_peer *peer)
  99 {
 100         list_del_rcu(&peer->list);
 101         kfree_rcu(peer, rcu);
 102
 103         module_put(THIS_MODULE);
 104
 105         if (atomic_dec_and_test(&dev->peer_count)) {
 106                 BT_DBG("last peer");
 107                 return true;
 108         }
 109
 110         return false;
 111 }
 112
 113 static inline struct lowpan_peer *peer_lookup_ba(struct lowpan_btle_dev *dev,
 114                                                  bdaddr_t *ba, __u8 type)
 115 {
 116         struct lowpan_peer *peer;
 117
 118         BT_DBG("peers %d addr %pMR type %d", atomic_read(&dev->peer_count),
 119                ba, type);
 120
 121         rcu_read_lock();
 122
 123         list_for_each_entry_rcu(peer, &dev->peers, list) {
 124                 BT_DBG("dst addr %pMR dst type %d",
 125                        &peer->chan->dst, peer->chan->dst_type);
 126
 127                 if (bacmp(&peer->chan->dst, ba))
 128                         continue;
 129
 130                 if (type == peer->chan->dst_type) {
 131                         rcu_read_unlock();
 132                         return peer;
 133                 }
 134         }
 135
 136         rcu_read_unlock();
 137
 138         return NULL;
 139 }
 140
 141 static inline struct lowpan_peer *
 142 __peer_lookup_chan(struct lowpan_btle_dev *dev, struct l2cap_chan *chan)
 143 {
 144         struct lowpan_peer *peer;
 145
 146         list_for_each_entry_rcu(peer, &dev->peers, list) {
 147                 if (peer->chan == chan)
 148                         return peer;
 149         }
 150
 151         return NULL;
 152 }
 153
 154 static inline struct lowpan_peer *
 155 __peer_lookup_conn(struct lowpan_btle_dev *dev, struct l2cap_conn *conn)
 156 {
 157         struct lowpan_peer *peer;
 158
 159         list_for_each_entry_rcu(peer, &dev->peers, list) {
 160                 if (peer->chan->conn == conn)
 161                         return peer;
 162         }
 163
 164         return NULL;
 165 }
 166
 167 static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_btle_dev *dev,
 168                                                   struct in6_addr *daddr,
 169                                                   struct sk_buff *skb)
 170 {
 171         struct lowpan_peer *peer;
 172         struct in6_addr *nexthop;
 173         struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
 174         int count = atomic_read(&dev->peer_count);
 175
 176         BT_DBG("peers %d addr %pI6c rt %p", count, daddr, rt);
 177
 178         /* If we have multiple 6lowpan peers, then check where we should
 179          * send the packet. If only one peer exists, then we can send the
 180          * packet right away.
 181          */
 182         if (count == 1) {
 183                 rcu_read_lock();
 184                 peer = list_first_or_null_rcu(&dev->peers, struct lowpan_peer,
 185                                               list);
 186                 rcu_read_unlock();
 187                 return peer;
 188         }
 189
 190         if (!rt) {
 191                 if (ipv6_addr_any(&lowpan_cb(skb)->gw)) {
 192                         /* There is neither route nor gateway,
 193                          * probably the destination is a direct peer.
 194                          */
 195                         nexthop = daddr;
 196                 } else {
 197                         /* There is a known gateway
 198                          */
 199                         nexthop = &lowpan_cb(skb)->gw;
 200                 }
 201         } else {
 202                 nexthop = rt6_nexthop(rt, daddr);
 203
 204                 /* We need to remember the address because it is needed
 205                  * by bt_xmit() when sending the packet. In bt_xmit(), the
 206                  * destination routing info is not set.
 207                  */
 208                 memcpy(&lowpan_cb(skb)->gw, nexthop, sizeof(struct in6_addr));
 209         }
 210
 211         BT_DBG("gw %pI6c", nexthop);
 212
 213         rcu_read_lock();
 214
 215         list_for_each_entry_rcu(peer, &dev->peers, list) {
 216                 BT_DBG("dst addr %pMR dst type %d ip %pI6c",
 217                        &peer->chan->dst, peer->chan->dst_type,
 218                        &peer->peer_addr);
 219
 220                 if (!ipv6_addr_cmp(&peer->peer_addr, nexthop)) {
 221                         rcu_read_unlock();
 222                         return peer;
 223                 }
 224         }
 225
 226         rcu_read_unlock();
 227
 228         return NULL;
 229 }
 230
 231 static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn)
 232 {
 233         struct lowpan_btle_dev *entry;
 234         struct lowpan_peer *peer = NULL;
 235
 236         rcu_read_lock();
 237
 238         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 239                 peer = __peer_lookup_conn(entry, conn);
 240                 if (peer)
 241                         break;
 242         }
 243
 244         rcu_read_unlock();
 245
 246         return peer;
 247 }
 248
 249 static struct lowpan_btle_dev *lookup_dev(struct l2cap_conn *conn)
 250 {
 251         struct lowpan_btle_dev *entry;
 252         struct lowpan_btle_dev *dev = NULL;
 253
 254         rcu_read_lock();
 255
 256         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 257                 if (conn->hcon->hdev == entry->hdev) {
 258                         dev = entry;
 259                         break;
 260                 }
 261         }
 262
 263         rcu_read_unlock();
 264
 265         return dev;
 266 }
 267
 268 static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev)
 269 {
 270         struct sk_buff *skb_cp;
 271
 272         skb_cp = skb_copy(skb, GFP_ATOMIC);
 273         if (!skb_cp)
 274                 return NET_RX_DROP;
 275
 276         return netif_rx_ni(skb_cp);
 277 }
 278
 279 static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev,
 280                            struct lowpan_peer *peer)
 281 {
 282         const u8 *saddr;
 283
 284         saddr = peer->lladdr;
 285
 286         return lowpan_header_decompress(skb, netdev, netdev->dev_addr, saddr);
 287 }
 288
 289 static int recv_pkt(struct sk_buff *skb, struct net_device *dev,
 290                     struct lowpan_peer *peer)
 291 {
 292         struct sk_buff *local_skb;
 293         int ret;
 294
 295         if (!netif_running(dev))
 296                 goto drop;
 297
 298         if (dev->type != ARPHRD_6LOWPAN || !skb->len)
 299                 goto drop;
 300
 301         skb_reset_network_header(skb);
 302
 303         skb = skb_share_check(skb, GFP_ATOMIC);
 304         if (!skb)
 305                 goto drop;
 306
 307         /* check that it's our buffer */
 308         if (lowpan_is_ipv6(*skb_network_header(skb))) {
 309                 /* Pull off the 1-byte of 6lowpan header. */
 310                 skb_pull(skb, 1);
 311
 312                 /* Copy the packet so that the IPv6 header is
 313                  * properly aligned.
 314                  */
 315                 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
 316                                             skb_tailroom(skb), GFP_ATOMIC);
 317                 if (!local_skb)
 318                         goto drop;
 319
 320                 local_skb->protocol = htons(ETH_P_IPV6);
 321                 local_skb->pkt_type = PACKET_HOST;
 322                 local_skb->dev = dev;
 323
 324                 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
 325
 326                 if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) {
 327                         kfree_skb(local_skb);
 328                         goto drop;
 329                 }
 330
 331                 dev->stats.rx_bytes += skb->len;
 332                 dev->stats.rx_packets++;
 333
 334                 consume_skb(local_skb);
 335                 consume_skb(skb);
 336         } else if (lowpan_is_iphc(*skb_network_header(skb))) {
 337                 local_skb = skb_clone(skb, GFP_ATOMIC);
 338                 if (!local_skb)
 339                         goto drop;
 340
 341                 local_skb->dev = dev;
 342
 343                 ret = iphc_decompress(local_skb, dev, peer);
 344                 if (ret < 0) {
 345                         BT_DBG("iphc_decompress failed: %d", ret);
 346                         kfree_skb(local_skb);
 347                         goto drop;
 348                 }
 349
 350                 local_skb->protocol = htons(ETH_P_IPV6);
 351                 local_skb->pkt_type = PACKET_HOST;
 352
 353                 if (give_skb_to_upper(local_skb, dev)
 354                                 != NET_RX_SUCCESS) {
 355                         kfree_skb(local_skb);
 356                         goto drop;
 357                 }
 358
 359                 dev->stats.rx_bytes += skb->len;
 360                 dev->stats.rx_packets++;
 361
 362                 consume_skb(local_skb);
 363                 consume_skb(skb);
 364         } else {
 365                 BT_DBG("unknown packet type");
 366                 goto drop;
 367         }
 368
 369         return NET_RX_SUCCESS;
 370
 371 drop:
 372         dev->stats.rx_dropped++;
 373         return NET_RX_DROP;
 374 }
 375
 376 /* Packet from BT LE device */
 377 static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
 378 {
 379         struct lowpan_btle_dev *dev;
 380         struct lowpan_peer *peer;
 381         int err;
 382
 383         peer = lookup_peer(chan->conn);
 384         if (!peer)
 385                 return -ENOENT;
 386
 387         dev = lookup_dev(chan->conn);
 388         if (!dev || !dev->netdev)
 389                 return -ENOENT;
 390
 391         err = recv_pkt(skb, dev->netdev, peer);
 392         if (err) {
 393                 BT_DBG("recv pkt %d", err);
 394                 err = -EAGAIN;
 395         }
 396
 397         return err;
 398 }
 399
 400 static int setup_header(struct sk_buff *skb, struct net_device *netdev,
 401                         bdaddr_t *peer_addr, u8 *peer_addr_type)
 402 {
 403         struct in6_addr ipv6_daddr;
 404         struct ipv6hdr *hdr;
 405         struct lowpan_btle_dev *dev;
 406         struct lowpan_peer *peer;
 407         u8 *daddr;
 408         int err, status = 0;
 409
 410         hdr = ipv6_hdr(skb);
 411
 412         dev = lowpan_btle_dev(netdev);
 413
 414         memcpy(&ipv6_daddr, &hdr->daddr, sizeof(ipv6_daddr));
 415
 416         if (ipv6_addr_is_multicast(&ipv6_daddr)) {
 417                 lowpan_cb(skb)->chan = NULL;
 418                 daddr = NULL;
 419         } else {
 420                 BT_DBG("dest IP %pI6c", &ipv6_daddr);
 421
 422                 /* The packet might be sent to 6lowpan interface
 423                  * because of routing (either via default route
 424                  * or user set route) so get peer according to
 425                  * the destination address.
 426                  */
 427                 peer = peer_lookup_dst(dev, &ipv6_daddr, skb);
 428                 if (!peer) {
 429                         BT_DBG("no such peer");
 430                         return -ENOENT;
 431                 }
 432
 433                 daddr = peer->lladdr;
 434                 *peer_addr = peer->chan->dst;
 435                 *peer_addr_type = peer->chan->dst_type;
 436                 lowpan_cb(skb)->chan = peer->chan;
 437
 438                 status = 1;
 439         }
 440
 441         lowpan_header_compress(skb, netdev, daddr, dev->netdev->dev_addr);
 442
 443         err = dev_hard_header(skb, netdev, ETH_P_IPV6, NULL, NULL, 0);
 444         if (err < 0)
 445                 return err;
 446
 447         return status;
 448 }
 449
 450 static int header_create(struct sk_buff *skb, struct net_device *netdev,
 451                          unsigned short type, const void *_daddr,
 452                          const void *_saddr, unsigned int len)
 453 {
 454         if (type != ETH_P_IPV6)
 455                 return -EINVAL;
 456
 457         return 0;
 458 }
 459
 460 /* Packet to BT LE device */
 461 static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb,
 462                     struct net_device *netdev)
 463 {
 464         struct msghdr msg;
 465         struct kvec iv;
 466         int err;
 467
 468         /* Remember the skb so that we can send EAGAIN to the caller if
 469          * we run out of credits.
 470          */
 471         chan->data = skb;
 472
 473         iv.iov_base = skb->data;
 474         iv.iov_len = skb->len;
 475
 476         memset(&msg, 0, sizeof(msg));
 477         iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, &iv, 1, skb->len);
 478
 479         err = l2cap_chan_send(chan, &msg, skb->len);
 480         if (err > 0) {
 481                 netdev->stats.tx_bytes += err;
 482                 netdev->stats.tx_packets++;
 483                 return 0;
 484         }
 485
 486         if (err < 0)
 487                 netdev->stats.tx_errors++;
 488
 489         return err;
 490 }
 491
 492 static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev)
 493 {
 494         struct sk_buff *local_skb;
 495         struct lowpan_btle_dev *entry;
 496         int err = 0;
 497
 498         rcu_read_lock();
 499
 500         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 501                 struct lowpan_peer *pentry;
 502                 struct lowpan_btle_dev *dev;
 503
 504                 if (entry->netdev != netdev)
 505                         continue;
 506
 507                 dev = lowpan_btle_dev(entry->netdev);
 508
 509                 list_for_each_entry_rcu(pentry, &dev->peers, list) {
 510                         int ret;
 511
 512                         local_skb = skb_clone(skb, GFP_ATOMIC);
 513
 514                         BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
 515                                netdev->name,
 516                                &pentry->chan->dst, pentry->chan->dst_type,
 517                                &pentry->peer_addr, pentry->chan);
 518                         ret = send_pkt(pentry->chan, local_skb, netdev);
 519                         if (ret < 0)
 520                                 err = ret;
 521
 522                         kfree_skb(local_skb);
 523                 }
 524         }
 525
 526         rcu_read_unlock();
 527
 528         return err;
 529 }
 530
 531 static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev)
 532 {
 533         int err = 0;
 534         bdaddr_t addr;
 535         u8 addr_type;
 536
 537         /* We must take a copy of the skb before we modify/replace the ipv6
 538          * header as the header could be used elsewhere
 539          */
 540         skb = skb_unshare(skb, GFP_ATOMIC);
 541         if (!skb)
 542                 return NET_XMIT_DROP;
 543
 544         /* Return values from setup_header()
 545          *  <0 - error, packet is dropped
 546          *   0 - this is a multicast packet
 547          *   1 - this is unicast packet
 548          */
 549         err = setup_header(skb, netdev, &addr, &addr_type);
 550         if (err < 0) {
 551                 kfree_skb(skb);
 552                 return NET_XMIT_DROP;
 553         }
 554
 555         if (err) {
 556                 if (lowpan_cb(skb)->chan) {
 557                         BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
 558                                netdev->name, &addr, addr_type,
 559                                &lowpan_cb(skb)->addr, lowpan_cb(skb)->chan);
 560                         err = send_pkt(lowpan_cb(skb)->chan, skb, netdev);
 561                 } else {
 562                         err = -ENOENT;
 563                 }
 564         } else {
 565                 /* We need to send the packet to every device behind this
 566                  * interface.
 567                  */
 568                 err = send_mcast_pkt(skb, netdev);
 569         }
 570
 571         dev_kfree_skb(skb);
 572
 573         if (err)
 574                 BT_DBG("ERROR: xmit failed (%d)", err);
 575
 576         return err < 0 ? NET_XMIT_DROP : err;
 577 }
 578
 579 static int bt_dev_init(struct net_device *dev)
 580 {
 581         netdev_lockdep_set_classes(dev);
 582
 583         return 0;
 584 }
 585
 586 static const struct net_device_ops netdev_ops = {
 587         .ndo_init               = bt_dev_init,
 588         .ndo_start_xmit         = bt_xmit,
 589 };
 590
 591 static struct header_ops header_ops = {
 592         .create = header_create,
 593 };
 594
 595 static void netdev_setup(struct net_device *dev)
 596 {
 597         dev->hard_header_len    = 0;
 598         dev->needed_tailroom    = 0;
 599         dev->flags              = IFF_RUNNING | IFF_MULTICAST;
 600         dev->watchdog_timeo     = 0;
 601         dev->tx_queue_len       = DEFAULT_TX_QUEUE_LEN;
 602
 603         dev->netdev_ops         = &netdev_ops;
 604         dev->header_ops         = &header_ops;
 605         dev->needs_free_netdev  = true;
 606 }
 607
 608 static struct device_type bt_type = {
 609         .name   = "bluetooth",
 610 };
 611
 612 static void ifup(struct net_device *netdev)
 613 {
 614         int err;
 615
 616         rtnl_lock();
 617         err = dev_open(netdev);
 618         if (err < 0)
 619                 BT_INFO("iface %s cannot be opened (%d)", netdev->name, err);
 620         rtnl_unlock();
 621 }
 622
 623 static void ifdown(struct net_device *netdev)
 624 {
 625         rtnl_lock();
 626         dev_close(netdev);
 627         rtnl_unlock();
 628 }
 629
 630 static void do_notify_peers(struct work_struct *work)
 631 {
 632         struct lowpan_btle_dev *dev = container_of(work, struct lowpan_btle_dev,
 633                                                    notify_peers.work);
 634
 635         netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */
 636 }
 637
 638 static bool is_bt_6lowpan(struct hci_conn *hcon)
 639 {
 640         if (hcon->type != LE_LINK)
 641                 return false;
 642
 643         if (!enable_6lowpan)
 644                 return false;
 645
 646         return true;
 647 }
 648
 649 static struct l2cap_chan *chan_create(void)
 650 {
 651         struct l2cap_chan *chan;
 652
 653         chan = l2cap_chan_create();
 654         if (!chan)
 655                 return NULL;
 656
 657         l2cap_chan_set_defaults(chan);
 658
 659         chan->chan_type = L2CAP_CHAN_CONN_ORIENTED;
 660         chan->mode = L2CAP_MODE_LE_FLOWCTL;
 661         chan->imtu = 1280;
 662
 663         return chan;
 664 }
 665
 666 static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan,
 667                                         struct lowpan_btle_dev *dev,
 668                                         bool new_netdev)
 669 {
 670         struct lowpan_peer *peer;
 671
 672         peer = kzalloc(sizeof(*peer), GFP_ATOMIC);
 673         if (!peer)
 674                 return NULL;
 675
 676         peer->chan = chan;
 677         memset(&peer->peer_addr, 0, sizeof(struct in6_addr));
 678
 679         baswap((void *)peer->lladdr, &chan->dst);
 680
 681         lowpan_iphc_uncompress_eui48_lladdr(&peer->peer_addr, peer->lladdr);
 682
 683         spin_lock(&devices_lock);
 684         INIT_LIST_HEAD(&peer->list);
 685         peer_add(dev, peer);
 686         spin_unlock(&devices_lock);
 687
 688         /* Notifying peers about us needs to be done without locks held */
 689         if (new_netdev)
 690                 INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers);
 691         schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100));
 692
 693         return peer->chan;
 694 }
 695
 696 static int setup_netdev(struct l2cap_chan *chan, struct lowpan_btle_dev **dev)
 697 {
 698         struct net_device *netdev;
 699         int err = 0;
 700
 701         netdev = alloc_netdev(LOWPAN_PRIV_SIZE(sizeof(struct lowpan_btle_dev)),
 702                               IFACE_NAME_TEMPLATE, NET_NAME_UNKNOWN,
 703                               netdev_setup);
 704         if (!netdev)
 705                 return -ENOMEM;
 706
 707         netdev->addr_assign_type = NET_ADDR_PERM;
 708         baswap((void *)netdev->dev_addr, &chan->src);
 709
 710         netdev->netdev_ops = &netdev_ops;
 711         SET_NETDEV_DEV(netdev, &chan->conn->hcon->hdev->dev);
 712         SET_NETDEV_DEVTYPE(netdev, &bt_type);
 713
 714         *dev = lowpan_btle_dev(netdev);
 715         (*dev)->netdev = netdev;
 716         (*dev)->hdev = chan->conn->hcon->hdev;
 717         INIT_LIST_HEAD(&(*dev)->peers);
 718
 719         spin_lock(&devices_lock);
 720         INIT_LIST_HEAD(&(*dev)->list);
 721         list_add_rcu(&(*dev)->list, &bt_6lowpan_devices);
 722         spin_unlock(&devices_lock);
 723
 724         err = lowpan_register_netdev(netdev, LOWPAN_LLTYPE_BTLE);
 725         if (err < 0) {
 726                 BT_INFO("register_netdev failed %d", err);
 727                 spin_lock(&devices_lock);
 728                 list_del_rcu(&(*dev)->list);
 729                 spin_unlock(&devices_lock);
 730                 free_netdev(netdev);
 731                 goto out;
 732         }
 733
 734         BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d",
 735                netdev->ifindex, &chan->dst, chan->dst_type,
 736                &chan->src, chan->src_type);
 737         set_bit(__LINK_STATE_PRESENT, &netdev->state);
 738
 739         return 0;
 740
 741 out:
 742         return err;
 743 }
 744
 745 static inline void chan_ready_cb(struct l2cap_chan *chan)
 746 {
 747         struct lowpan_btle_dev *dev;
 748         bool new_netdev = false;
 749
 750         dev = lookup_dev(chan->conn);
 751
 752         BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev);
 753
 754         if (!dev) {
 755                 if (setup_netdev(chan, &dev) < 0) {
 756                         l2cap_chan_del(chan, -ENOENT);
 757                         return;
 758                 }
 759                 new_netdev = true;
 760         }
 761
 762         if (!try_module_get(THIS_MODULE))
 763                 return;
 764
 765         add_peer_chan(chan, dev, new_netdev);
 766         ifup(dev->netdev);
 767 }
 768
 769 static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan)
 770 {
 771         struct l2cap_chan *chan;
 772
 773         chan = chan_create();
 774         if (!chan)
 775                 return NULL;
 776
 777         chan->ops = pchan->ops;
 778
 779         BT_DBG("chan %p pchan %p", chan, pchan);
 780
 781         return chan;
 782 }
 783
 784 static void delete_netdev(struct work_struct *work)
 785 {
 786         struct lowpan_btle_dev *entry = container_of(work,
 787                                                      struct lowpan_btle_dev,
 788                                                      delete_netdev);
 789
 790         lowpan_unregister_netdev(entry->netdev);
 791
 792         /* The entry pointer is deleted by the netdev destructor. */
 793 }
 794
 795 static void chan_close_cb(struct l2cap_chan *chan)
 796 {
 797         struct lowpan_btle_dev *entry;
 798         struct lowpan_btle_dev *dev = NULL;
 799         struct lowpan_peer *peer;
 800         int err = -ENOENT;
 801         bool last = false, remove = true;
 802
 803         BT_DBG("chan %p conn %p", chan, chan->conn);
 804
 805         if (chan->conn && chan->conn->hcon) {
 806                 if (!is_bt_6lowpan(chan->conn->hcon))
 807                         return;
 808
 809                 /* If conn is set, then the netdev is also there and we should
 810                  * not remove it.
 811                  */
 812                 remove = false;
 813         }
 814
 815         spin_lock(&devices_lock);
 816
 817         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 818                 dev = lowpan_btle_dev(entry->netdev);
 819                 peer = __peer_lookup_chan(dev, chan);
 820                 if (peer) {
 821                         last = peer_del(dev, peer);
 822                         err = 0;
 823
 824                         BT_DBG("dev %p removing %speer %p", dev,
 825                                last ? "last " : "1 ", peer);
 826                         BT_DBG("chan %p orig refcnt %d", chan,
 827                                kref_read(&chan->kref));
 828
 829                         l2cap_chan_put(chan);
 830                         break;
 831                 }
 832         }
 833
 834         if (!err && last && dev && !atomic_read(&dev->peer_count)) {
 835                 spin_unlock(&devices_lock);
 836
 837                 cancel_delayed_work_sync(&dev->notify_peers);
 838
 839                 ifdown(dev->netdev);
 840
 841                 if (remove) {
 842                         INIT_WORK(&entry->delete_netdev, delete_netdev);
 843                         schedule_work(&entry->delete_netdev);
 844                 }
 845         } else {
 846                 spin_unlock(&devices_lock);
 847         }
 848
 849         return;
 850 }
 851
 852 static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err)
 853 {
 854         BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn,
 855                state_to_string(state), err);
 856 }
 857
 858 static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan,
 859                                          unsigned long hdr_len,
 860                                          unsigned long len, int nb)
 861 {
 862         /* Note that we must allocate using GFP_ATOMIC here as
 863          * this function is called originally from netdev hard xmit
 864          * function in atomic context.
 865          */
 866         return bt_skb_alloc(hdr_len + len, GFP_ATOMIC);
 867 }
 868
 869 static void chan_suspend_cb(struct l2cap_chan *chan)
 870 {
 871         struct lowpan_btle_dev *dev;
 872
 873         BT_DBG("chan %p suspend", chan);
 874
 875         dev = lookup_dev(chan->conn);
 876         if (!dev || !dev->netdev)
 877                 return;
 878
 879         netif_stop_queue(dev->netdev);
 880 }
 881
 882 static void chan_resume_cb(struct l2cap_chan *chan)
 883 {
 884         struct lowpan_btle_dev *dev;
 885
 886         BT_DBG("chan %p resume", chan);
 887
 888         dev = lookup_dev(chan->conn);
 889         if (!dev || !dev->netdev)
 890                 return;
 891
 892         netif_wake_queue(dev->netdev);
 893 }
 894
 895 static long chan_get_sndtimeo_cb(struct l2cap_chan *chan)
 896 {
 897         return L2CAP_CONN_TIMEOUT;
 898 }
 899
 900 static const struct l2cap_ops bt_6lowpan_chan_ops = {
 901         .name                   = "L2CAP 6LoWPAN channel",
 902         .new_connection         = chan_new_conn_cb,
 903         .recv                   = chan_recv_cb,
 904         .close                  = chan_close_cb,
 905         .state_change           = chan_state_change_cb,
 906         .ready                  = chan_ready_cb,
 907         .resume                 = chan_resume_cb,
 908         .suspend                = chan_suspend_cb,
 909         .get_sndtimeo           = chan_get_sndtimeo_cb,
 910         .alloc_skb              = chan_alloc_skb_cb,
 911
 912         .teardown               = l2cap_chan_no_teardown,
 913         .defer                  = l2cap_chan_no_defer,
 914         .set_shutdown           = l2cap_chan_no_set_shutdown,
 915 };
 916
 917 static inline __u8 bdaddr_type(__u8 type)
 918 {
 919         if (type == ADDR_LE_DEV_PUBLIC)
 920                 return BDADDR_LE_PUBLIC;
 921         else
 922                 return BDADDR_LE_RANDOM;
 923 }
 924
 925 static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type)
 926 {
 927         struct l2cap_chan *chan;
 928         int err;
 929
 930         chan = chan_create();
 931         if (!chan)
 932                 return -EINVAL;
 933
 934         chan->ops = &bt_6lowpan_chan_ops;
 935
 936         err = l2cap_chan_connect(chan, cpu_to_le16(L2CAP_PSM_IPSP), 0,
 937                                  addr, dst_type);
 938
 939         BT_DBG("chan %p err %d", chan, err);
 940         if (err < 0)
 941                 l2cap_chan_put(chan);
 942
 943         return err;
 944 }
 945
 946 static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type)
 947 {
 948         struct lowpan_peer *peer;
 949
 950         BT_DBG("conn %p dst type %d", conn, dst_type);
 951
 952         peer = lookup_peer(conn);
 953         if (!peer)
 954                 return -ENOENT;
 955
 956         BT_DBG("peer %p chan %p", peer, peer->chan);
 957
 958         l2cap_chan_close(peer->chan, ENOENT);
 959
 960         return 0;
 961 }
 962
 963 static struct l2cap_chan *bt_6lowpan_listen(void)
 964 {
 965         bdaddr_t *addr = BDADDR_ANY;
 966         struct l2cap_chan *chan;
 967         int err;
 968
 969         if (!enable_6lowpan)
 970                 return NULL;
 971
 972         chan = chan_create();
 973         if (!chan)
 974                 return NULL;
 975
 976         chan->ops = &bt_6lowpan_chan_ops;
 977         chan->state = BT_LISTEN;
 978         chan->src_type = BDADDR_LE_PUBLIC;
 979
 980         atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
 981
 982         BT_DBG("chan %p src type %d", chan, chan->src_type);
 983
 984         err = l2cap_add_psm(chan, addr, cpu_to_le16(L2CAP_PSM_IPSP));
 985         if (err) {
 986                 l2cap_chan_put(chan);
 987                 BT_ERR("psm cannot be added err %d", err);
 988                 return NULL;
 989         }
 990
 991         return chan;
 992 }
 993
 994 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type,
 995                           struct l2cap_conn **conn)
 996 {
 997         struct hci_conn *hcon;
 998         struct hci_dev *hdev;
 999         int n;
1000
1001         n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu",
1002                    &addr->b[5], &addr->b[4], &addr->b[3],
1003                    &addr->b[2], &addr->b[1], &addr->b[0],
1004                    addr_type);
1005
1006         if (n < 7)
1007                 return -EINVAL;
1008
1009         /* The LE_PUBLIC address type is ignored because of BDADDR_ANY */
1010         hdev = hci_get_route(addr, BDADDR_ANY, BDADDR_LE_PUBLIC);
1011         if (!hdev)
1012                 return -ENOENT;
1013
1014         hci_dev_lock(hdev);
1015         hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type);
1016         hci_dev_unlock(hdev);
1017
1018         if (!hcon)
1019                 return -ENOENT;
1020
1021         *conn = (struct l2cap_conn *)hcon->l2cap_data;
1022
1023         BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type);
1024
1025         return 0;
1026 }
1027
1028 static void disconnect_all_peers(void)
1029 {
1030         struct lowpan_btle_dev *entry;
1031         struct lowpan_peer *peer, *tmp_peer, *new_peer;
1032         struct list_head peers;
1033
1034         INIT_LIST_HEAD(&peers);
1035
1036         /* We make a separate list of peers as the close_cb() will
1037          * modify the device peers list so it is better not to mess
1038          * with the same list at the same time.
1039          */
1040
1041         rcu_read_lock();
1042
1043         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1044                 list_for_each_entry_rcu(peer, &entry->peers, list) {
1045                         new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC);
1046                         if (!new_peer)
1047                                 break;
1048
1049                         new_peer->chan = peer->chan;
1050                         INIT_LIST_HEAD(&new_peer->list);
1051
1052                         list_add(&new_peer->list, &peers);
1053                 }
1054         }
1055
1056         rcu_read_unlock();
1057
1058         spin_lock(&devices_lock);
1059         list_for_each_entry_safe(peer, tmp_peer, &peers, list) {
1060                 l2cap_chan_close(peer->chan, ENOENT);
1061
1062                 list_del_rcu(&peer->list);
1063                 kfree_rcu(peer, rcu);
1064         }
1065         spin_unlock(&devices_lock);
1066 }
1067
1068 struct set_enable {
1069         struct work_struct work;
1070         bool flag;
1071 };
1072
1073 static void do_enable_set(struct work_struct *work)
1074 {
1075         struct set_enable *set_enable = container_of(work,
1076                                                      struct set_enable, work);
1077
1078         if (!set_enable->flag || enable_6lowpan != set_enable->flag)
1079                 /* Disconnect existing connections if 6lowpan is
1080                  * disabled
1081                  */
1082                 disconnect_all_peers();
1083
1084         enable_6lowpan = set_enable->flag;
1085
1086         mutex_lock(&set_lock);
1087         if (listen_chan) {
1088                 l2cap_chan_close(listen_chan, 0);
1089                 l2cap_chan_put(listen_chan);
1090         }
1091
1092         listen_chan = bt_6lowpan_listen();
1093         mutex_unlock(&set_lock);
1094
1095         kfree(set_enable);
1096 }
1097
1098 static int lowpan_enable_set(void *data, u64 val)
1099 {
1100         struct set_enable *set_enable;
1101
1102         set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL);
1103         if (!set_enable)
1104                 return -ENOMEM;
1105
1106         set_enable->flag = !!val;
1107         INIT_WORK(&set_enable->work, do_enable_set);
1108
1109         schedule_work(&set_enable->work);
1110
1111         return 0;
1112 }
1113
1114 static int lowpan_enable_get(void *data, u64 *val)
1115 {
1116         *val = enable_6lowpan;
1117         return 0;
1118 }
1119
1120 DEFINE_SIMPLE_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get,
1121                         lowpan_enable_set, "%llu\n");
1122
1123 static ssize_t lowpan_control_write(struct file *fp,
1124                                     const char __user *user_buffer,
1125                                     size_t count,
1126                                     loff_t *position)
1127 {
1128         char buf[32];
1129         size_t buf_size = min(count, sizeof(buf) - 1);
1130         int ret;
1131         bdaddr_t addr;
1132         u8 addr_type;
1133         struct l2cap_conn *conn = NULL;
1134
1135         if (copy_from_user(buf, user_buffer, buf_size))
1136                 return -EFAULT;
1137
1138         buf[buf_size] = '\0';
1139
1140         if (memcmp(buf, "connect ", 8) == 0) {
1141                 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn);
1142                 if (ret == -EINVAL)
1143                         return ret;
1144
1145                 mutex_lock(&set_lock);
1146                 if (listen_chan) {
1147                         l2cap_chan_close(listen_chan, 0);
1148                         l2cap_chan_put(listen_chan);
1149                         listen_chan = NULL;
1150                 }
1151                 mutex_unlock(&set_lock);
1152
1153                 if (conn) {
1154                         struct lowpan_peer *peer;
1155
1156                         if (!is_bt_6lowpan(conn->hcon))
1157                                 return -EINVAL;
1158
1159                         peer = lookup_peer(conn);
1160                         if (peer) {
1161                                 BT_DBG("6LoWPAN connection already exists");
1162                                 return -EALREADY;
1163                         }
1164
1165                         BT_DBG("conn %p dst %pMR type %d user %d", conn,
1166                                &conn->hcon->dst, conn->hcon->dst_type,
1167                                addr_type);
1168                 }
1169
1170                 ret = bt_6lowpan_connect(&addr, addr_type);
1171                 if (ret < 0)
1172                         return ret;
1173
1174                 return count;
1175         }
1176
1177         if (memcmp(buf, "disconnect ", 11) == 0) {
1178                 ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn);
1179                 if (ret < 0)
1180                         return ret;
1181
1182                 ret = bt_6lowpan_disconnect(conn, addr_type);
1183                 if (ret < 0)
1184                         return ret;
1185
1186                 return count;
1187         }
1188
1189         return count;
1190 }
1191
1192 static int lowpan_control_show(struct seq_file *f, void *ptr)
1193 {
1194         struct lowpan_btle_dev *entry;
1195         struct lowpan_peer *peer;
1196
1197         spin_lock(&devices_lock);
1198
1199         list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1200                 list_for_each_entry(peer, &entry->peers, list)
1201                         seq_printf(f, "%pMR (type %u)\n",
1202                                    &peer->chan->dst, peer->chan->dst_type);
1203         }
1204
1205         spin_unlock(&devices_lock);
1206
1207         return 0;
1208 }
1209
1210 static int lowpan_control_open(struct inode *inode, struct file *file)
1211 {
1212         return single_open(file, lowpan_control_show, inode->i_private);
1213 }
1214
1215 static const struct file_operations lowpan_control_fops = {
1216         .open           = lowpan_control_open,
1217         .read           = seq_read,
1218         .write          = lowpan_control_write,
1219         .llseek         = seq_lseek,
1220         .release        = single_release,
1221 };
1222
1223 static void disconnect_devices(void)
1224 {
1225         struct lowpan_btle_dev *entry, *tmp, *new_dev;
1226         struct list_head devices;
1227
1228         INIT_LIST_HEAD(&devices);
1229
1230         /* We make a separate list of devices because the unregister_netdev()
1231          * will call device_event() which will also want to modify the same
1232          * devices list.
1233          */
1234
1235         rcu_read_lock();
1236
1237         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1238                 new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC);
1239                 if (!new_dev)
1240                         break;
1241
1242                 new_dev->netdev = entry->netdev;
1243                 INIT_LIST_HEAD(&new_dev->list);
1244
1245                 list_add_rcu(&new_dev->list, &devices);
1246         }
1247
1248         rcu_read_unlock();
1249
1250         list_for_each_entry_safe(entry, tmp, &devices, list) {
1251                 ifdown(entry->netdev);
1252                 BT_DBG("Unregistering netdev %s %p",
1253                        entry->netdev->name, entry->netdev);
1254                 lowpan_unregister_netdev(entry->netdev);
1255                 kfree(entry);
1256         }
1257 }
1258
1259 static int device_event(struct notifier_block *unused,
1260                         unsigned long event, void *ptr)
1261 {
1262         struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
1263         struct lowpan_btle_dev *entry;
1264
1265         if (netdev->type != ARPHRD_6LOWPAN)
1266                 return NOTIFY_DONE;
1267
1268         switch (event) {
1269         case NETDEV_UNREGISTER:
1270                 spin_lock(&devices_lock);
1271                 list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1272                         if (entry->netdev == netdev) {
1273                                 BT_DBG("Unregistered netdev %s %p",
1274                                        netdev->name, netdev);
1275                                 list_del(&entry->list);
1276                                 break;
1277                         }
1278                 }
1279                 spin_unlock(&devices_lock);
1280                 break;
1281         }
1282
1283         return NOTIFY_DONE;
1284 }
1285
1286 static struct notifier_block bt_6lowpan_dev_notifier = {
1287         .notifier_call = device_event,
1288 };
1289
1290 static int __init bt_6lowpan_init(void)
1291 {
1292         lowpan_enable_debugfs = debugfs_create_file("6lowpan_enable", 0644,
1293                                                     bt_debugfs, NULL,
1294                                                     &lowpan_enable_fops);
1295         lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644,
1296                                                      bt_debugfs, NULL,
1297                                                      &lowpan_control_fops);
1298
1299         return register_netdevice_notifier(&bt_6lowpan_dev_notifier);
1300 }
1301
1302 static void __exit bt_6lowpan_exit(void)
1303 {
1304         debugfs_remove(lowpan_enable_debugfs);
1305         debugfs_remove(lowpan_control_debugfs);
1306
1307         if (listen_chan) {
1308                 l2cap_chan_close(listen_chan, 0);
1309                 l2cap_chan_put(listen_chan);
1310         }
1311
1312         disconnect_devices();
1313
1314         unregister_netdevice_notifier(&bt_6lowpan_dev_notifier);
1315 }
1316
1317 module_init(bt_6lowpan_init);
1318 module_exit(bt_6lowpan_exit);
1319
1320 MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>");
1321 MODULE_DESCRIPTION("Bluetooth 6LoWPAN");
1322 MODULE_VERSION(VERSION);
1323 MODULE_LICENSE("GPL");