net/bluetooth/6lowpan.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3    Copyright (c) 2013-2014 Intel Corp.
   4
   5 */
   6
   7 #include <linux/if_arp.h>
   8 #include <linux/netdevice.h>
   9 #include <linux/etherdevice.h>
  10 #include <linux/module.h>
  11 #include <linux/debugfs.h>
  12
  13 #include <net/ipv6.h>
  14 #include <net/ip6_route.h>
  15 #include <net/addrconf.h>
  16 #include <net/pkt_sched.h>
  17
  18 #include <net/bluetooth/bluetooth.h>
  19 #include <net/bluetooth/hci_core.h>
  20 #include <net/bluetooth/l2cap.h>
  21
  22 #include <net/6lowpan.h> /* for the compression support */
  23
  24 #define VERSION "0.1"
  25
  26 static struct dentry *lowpan_enable_debugfs;
  27 static struct dentry *lowpan_control_debugfs;
  28
  29 #define IFACE_NAME_TEMPLATE "bt%d"
  30
  31 struct skb_cb {
  32         struct in6_addr addr;
  33         struct in6_addr gw;
  34         struct l2cap_chan *chan;
  35 };
  36 #define lowpan_cb(skb) ((struct skb_cb *)((skb)->cb))
  37
  38 /* The devices list contains those devices that we are acting
  39  * as a proxy. The BT 6LoWPAN device is a virtual device that
  40  * connects to the Bluetooth LE device. The real connection to
  41  * BT device is done via l2cap layer. There exists one
  42  * virtual device / one BT 6LoWPAN network (=hciX device).
  43  * The list contains struct lowpan_dev elements.
  44  */
  45 static LIST_HEAD(bt_6lowpan_devices);
  46 static DEFINE_SPINLOCK(devices_lock);
  47
  48 static bool enable_6lowpan;
  49
  50 /* We are listening incoming connections via this channel
  51  */
  52 static struct l2cap_chan *listen_chan;
  53 static DEFINE_MUTEX(set_lock);
  54
  55 struct lowpan_peer {
  56         struct list_head list;
  57         struct rcu_head rcu;
  58         struct l2cap_chan *chan;
  59
  60         /* peer addresses in various formats */
  61         unsigned char lladdr[ETH_ALEN];
  62         struct in6_addr peer_addr;
  63 };
  64
  65 struct lowpan_btle_dev {
  66         struct list_head list;
  67
  68         struct hci_dev *hdev;
  69         struct net_device *netdev;
  70         struct list_head peers;
  71         atomic_t peer_count; /* number of items in peers list */
  72
  73         struct work_struct delete_netdev;
  74         struct delayed_work notify_peers;
  75 };
  76
  77 static inline struct lowpan_btle_dev *
  78 lowpan_btle_dev(const struct net_device *netdev)
  79 {
  80         return (struct lowpan_btle_dev *)lowpan_dev(netdev)->priv;
  81 }
  82
  83 static inline void peer_add(struct lowpan_btle_dev *dev,
  84                             struct lowpan_peer *peer)
  85 {
  86         list_add_rcu(&peer->list, &dev->peers);
  87         atomic_inc(&dev->peer_count);
  88 }
  89
  90 static inline bool peer_del(struct lowpan_btle_dev *dev,
  91                             struct lowpan_peer *peer)
  92 {
  93         list_del_rcu(&peer->list);
  94         kfree_rcu(peer, rcu);
  95
  96         module_put(THIS_MODULE);
  97
  98         if (atomic_dec_and_test(&dev->peer_count)) {
  99                 BT_DBG("last peer");
 100                 return true;
 101         }
 102
 103         return false;
 104 }
 105
 106 static inline struct lowpan_peer *peer_lookup_ba(struct lowpan_btle_dev *dev,
 107                                                  bdaddr_t *ba, __u8 type)
 108 {
 109         struct lowpan_peer *peer;
 110
 111         BT_DBG("peers %d addr %pMR type %d", atomic_read(&dev->peer_count),
 112                ba, type);
 113
 114         rcu_read_lock();
 115
 116         list_for_each_entry_rcu(peer, &dev->peers, list) {
 117                 BT_DBG("dst addr %pMR dst type %d",
 118                        &peer->chan->dst, peer->chan->dst_type);
 119
 120                 if (bacmp(&peer->chan->dst, ba))
 121                         continue;
 122
 123                 if (type == peer->chan->dst_type) {
 124                         rcu_read_unlock();
 125                         return peer;
 126                 }
 127         }
 128
 129         rcu_read_unlock();
 130
 131         return NULL;
 132 }
 133
 134 static inline struct lowpan_peer *
 135 __peer_lookup_chan(struct lowpan_btle_dev *dev, struct l2cap_chan *chan)
 136 {
 137         struct lowpan_peer *peer;
 138
 139         list_for_each_entry_rcu(peer, &dev->peers, list) {
 140                 if (peer->chan == chan)
 141                         return peer;
 142         }
 143
 144         return NULL;
 145 }
 146
 147 static inline struct lowpan_peer *
 148 __peer_lookup_conn(struct lowpan_btle_dev *dev, struct l2cap_conn *conn)
 149 {
 150         struct lowpan_peer *peer;
 151
 152         list_for_each_entry_rcu(peer, &dev->peers, list) {
 153                 if (peer->chan->conn == conn)
 154                         return peer;
 155         }
 156
 157         return NULL;
 158 }
 159
 160 static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_btle_dev *dev,
 161                                                   struct in6_addr *daddr,
 162                                                   struct sk_buff *skb)
 163 {
 164         struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
 165         int count = atomic_read(&dev->peer_count);
 166         const struct in6_addr *nexthop;
 167         struct lowpan_peer *peer;
 168         struct neighbour *neigh;
 169
 170         BT_DBG("peers %d addr %pI6c rt %p", count, daddr, rt);
 171
 172         if (!rt) {
 173                 if (ipv6_addr_any(&lowpan_cb(skb)->gw)) {
 174                         /* There is neither route nor gateway,
 175                          * probably the destination is a direct peer.
 176                          */
 177                         nexthop = daddr;
 178                 } else {
 179                         /* There is a known gateway
 180                          */
 181                         nexthop = &lowpan_cb(skb)->gw;
 182                 }
 183         } else {
 184                 nexthop = rt6_nexthop(rt, daddr);
 185
 186                 /* We need to remember the address because it is needed
 187                  * by bt_xmit() when sending the packet. In bt_xmit(), the
 188                  * destination routing info is not set.
 189                  */
 190                 memcpy(&lowpan_cb(skb)->gw, nexthop, sizeof(struct in6_addr));
 191         }
 192
 193         BT_DBG("gw %pI6c", nexthop);
 194
 195         rcu_read_lock();
 196
 197         list_for_each_entry_rcu(peer, &dev->peers, list) {
 198                 BT_DBG("dst addr %pMR dst type %d ip %pI6c",
 199                        &peer->chan->dst, peer->chan->dst_type,
 200                        &peer->peer_addr);
 201
 202                 if (!ipv6_addr_cmp(&peer->peer_addr, nexthop)) {
 203                         rcu_read_unlock();
 204                         return peer;
 205                 }
 206         }
 207
 208         /* use the neighbour cache for matching addresses assigned by SLAAC
 209         */
 210         neigh = __ipv6_neigh_lookup(dev->netdev, nexthop);
 211         if (neigh) {
 212                 list_for_each_entry_rcu(peer, &dev->peers, list) {
 213                         if (!memcmp(neigh->ha, peer->lladdr, ETH_ALEN)) {
 214                                 neigh_release(neigh);
 215                                 rcu_read_unlock();
 216                                 return peer;
 217                         }
 218                 }
 219                 neigh_release(neigh);
 220         }
 221
 222         rcu_read_unlock();
 223
 224         return NULL;
 225 }
 226
 227 static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn)
 228 {
 229         struct lowpan_btle_dev *entry;
 230         struct lowpan_peer *peer = NULL;
 231
 232         rcu_read_lock();
 233
 234         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 235                 peer = __peer_lookup_conn(entry, conn);
 236                 if (peer)
 237                         break;
 238         }
 239
 240         rcu_read_unlock();
 241
 242         return peer;
 243 }
 244
 245 static struct lowpan_btle_dev *lookup_dev(struct l2cap_conn *conn)
 246 {
 247         struct lowpan_btle_dev *entry;
 248         struct lowpan_btle_dev *dev = NULL;
 249
 250         rcu_read_lock();
 251
 252         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 253                 if (conn->hcon->hdev == entry->hdev) {
 254                         dev = entry;
 255                         break;
 256                 }
 257         }
 258
 259         rcu_read_unlock();
 260
 261         return dev;
 262 }
 263
 264 static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev)
 265 {
 266         struct sk_buff *skb_cp;
 267
 268         skb_cp = skb_copy(skb, GFP_ATOMIC);
 269         if (!skb_cp)
 270                 return NET_RX_DROP;
 271
 272         return netif_rx_ni(skb_cp);
 273 }
 274
 275 static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev,
 276                            struct lowpan_peer *peer)
 277 {
 278         const u8 *saddr;
 279
 280         saddr = peer->lladdr;
 281
 282         return lowpan_header_decompress(skb, netdev, netdev->dev_addr, saddr);
 283 }
 284
 285 static int recv_pkt(struct sk_buff *skb, struct net_device *dev,
 286                     struct lowpan_peer *peer)
 287 {
 288         struct sk_buff *local_skb;
 289         int ret;
 290
 291         if (!netif_running(dev))
 292                 goto drop;
 293
 294         if (dev->type != ARPHRD_6LOWPAN || !skb->len)
 295                 goto drop;
 296
 297         skb_reset_network_header(skb);
 298
 299         skb = skb_share_check(skb, GFP_ATOMIC);
 300         if (!skb)
 301                 goto drop;
 302
 303         /* check that it's our buffer */
 304         if (lowpan_is_ipv6(*skb_network_header(skb))) {
 305                 /* Pull off the 1-byte of 6lowpan header. */
 306                 skb_pull(skb, 1);
 307
 308                 /* Copy the packet so that the IPv6 header is
 309                  * properly aligned.
 310                  */
 311                 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
 312                                             skb_tailroom(skb), GFP_ATOMIC);
 313                 if (!local_skb)
 314                         goto drop;
 315
 316                 local_skb->protocol = htons(ETH_P_IPV6);
 317                 local_skb->pkt_type = PACKET_HOST;
 318                 local_skb->dev = dev;
 319
 320                 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
 321
 322                 if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) {
 323                         kfree_skb(local_skb);
 324                         goto drop;
 325                 }
 326
 327                 dev->stats.rx_bytes += skb->len;
 328                 dev->stats.rx_packets++;
 329
 330                 consume_skb(local_skb);
 331                 consume_skb(skb);
 332         } else if (lowpan_is_iphc(*skb_network_header(skb))) {
 333                 local_skb = skb_clone(skb, GFP_ATOMIC);
 334                 if (!local_skb)
 335                         goto drop;
 336
 337                 local_skb->dev = dev;
 338
 339                 ret = iphc_decompress(local_skb, dev, peer);
 340                 if (ret < 0) {
 341                         BT_DBG("iphc_decompress failed: %d", ret);
 342                         kfree_skb(local_skb);
 343                         goto drop;
 344                 }
 345
 346                 local_skb->protocol = htons(ETH_P_IPV6);
 347                 local_skb->pkt_type = PACKET_HOST;
 348
 349                 if (give_skb_to_upper(local_skb, dev)
 350                                 != NET_RX_SUCCESS) {
 351                         kfree_skb(local_skb);
 352                         goto drop;
 353                 }
 354
 355                 dev->stats.rx_bytes += skb->len;
 356                 dev->stats.rx_packets++;
 357
 358                 consume_skb(local_skb);
 359                 consume_skb(skb);
 360         } else {
 361                 BT_DBG("unknown packet type");
 362                 goto drop;
 363         }
 364
 365         return NET_RX_SUCCESS;
 366
 367 drop:
 368         dev->stats.rx_dropped++;
 369         return NET_RX_DROP;
 370 }
 371
 372 /* Packet from BT LE device */
 373 static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
 374 {
 375         struct lowpan_btle_dev *dev;
 376         struct lowpan_peer *peer;
 377         int err;
 378
 379         peer = lookup_peer(chan->conn);
 380         if (!peer)
 381                 return -ENOENT;
 382
 383         dev = lookup_dev(chan->conn);
 384         if (!dev || !dev->netdev)
 385                 return -ENOENT;
 386
 387         err = recv_pkt(skb, dev->netdev, peer);
 388         if (err) {
 389                 BT_DBG("recv pkt %d", err);
 390                 err = -EAGAIN;
 391         }
 392
 393         return err;
 394 }
 395
 396 static int setup_header(struct sk_buff *skb, struct net_device *netdev,
 397                         bdaddr_t *peer_addr, u8 *peer_addr_type)
 398 {
 399         struct in6_addr ipv6_daddr;
 400         struct ipv6hdr *hdr;
 401         struct lowpan_btle_dev *dev;
 402         struct lowpan_peer *peer;
 403         u8 *daddr;
 404         int err, status = 0;
 405
 406         hdr = ipv6_hdr(skb);
 407
 408         dev = lowpan_btle_dev(netdev);
 409
 410         memcpy(&ipv6_daddr, &hdr->daddr, sizeof(ipv6_daddr));
 411
 412         if (ipv6_addr_is_multicast(&ipv6_daddr)) {
 413                 lowpan_cb(skb)->chan = NULL;
 414                 daddr = NULL;
 415         } else {
 416                 BT_DBG("dest IP %pI6c", &ipv6_daddr);
 417
 418                 /* The packet might be sent to 6lowpan interface
 419                  * because of routing (either via default route
 420                  * or user set route) so get peer according to
 421                  * the destination address.
 422                  */
 423                 peer = peer_lookup_dst(dev, &ipv6_daddr, skb);
 424                 if (!peer) {
 425                         BT_DBG("no such peer");
 426                         return -ENOENT;
 427                 }
 428
 429                 daddr = peer->lladdr;
 430                 *peer_addr = peer->chan->dst;
 431                 *peer_addr_type = peer->chan->dst_type;
 432                 lowpan_cb(skb)->chan = peer->chan;
 433
 434                 status = 1;
 435         }
 436
 437         lowpan_header_compress(skb, netdev, daddr, dev->netdev->dev_addr);
 438
 439         err = dev_hard_header(skb, netdev, ETH_P_IPV6, NULL, NULL, 0);
 440         if (err < 0)
 441                 return err;
 442
 443         return status;
 444 }
 445
 446 static int header_create(struct sk_buff *skb, struct net_device *netdev,
 447                          unsigned short type, const void *_daddr,
 448                          const void *_saddr, unsigned int len)
 449 {
 450         if (type != ETH_P_IPV6)
 451                 return -EINVAL;
 452
 453         return 0;
 454 }
 455
 456 /* Packet to BT LE device */
 457 static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb,
 458                     struct net_device *netdev)
 459 {
 460         struct msghdr msg;
 461         struct kvec iv;
 462         int err;
 463
 464         /* Remember the skb so that we can send EAGAIN to the caller if
 465          * we run out of credits.
 466          */
 467         chan->data = skb;
 468
 469         iv.iov_base = skb->data;
 470         iv.iov_len = skb->len;
 471
 472         memset(&msg, 0, sizeof(msg));
 473         iov_iter_kvec(&msg.msg_iter, WRITE, &iv, 1, skb->len);
 474
 475         err = l2cap_chan_send(chan, &msg, skb->len);
 476         if (err > 0) {
 477                 netdev->stats.tx_bytes += err;
 478                 netdev->stats.tx_packets++;
 479                 return 0;
 480         }
 481
 482         if (err < 0)
 483                 netdev->stats.tx_errors++;
 484
 485         return err;
 486 }
 487
 488 static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev)
 489 {
 490         struct sk_buff *local_skb;
 491         struct lowpan_btle_dev *entry;
 492         int err = 0;
 493
 494         rcu_read_lock();
 495
 496         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 497                 struct lowpan_peer *pentry;
 498                 struct lowpan_btle_dev *dev;
 499
 500                 if (entry->netdev != netdev)
 501                         continue;
 502
 503                 dev = lowpan_btle_dev(entry->netdev);
 504
 505                 list_for_each_entry_rcu(pentry, &dev->peers, list) {
 506                         int ret;
 507
 508                         local_skb = skb_clone(skb, GFP_ATOMIC);
 509
 510                         BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
 511                                netdev->name,
 512                                &pentry->chan->dst, pentry->chan->dst_type,
 513                                &pentry->peer_addr, pentry->chan);
 514                         ret = send_pkt(pentry->chan, local_skb, netdev);
 515                         if (ret < 0)
 516                                 err = ret;
 517
 518                         kfree_skb(local_skb);
 519                 }
 520         }
 521
 522         rcu_read_unlock();
 523
 524         return err;
 525 }
 526
 527 static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev)
 528 {
 529         int err = 0;
 530         bdaddr_t addr;
 531         u8 addr_type;
 532
 533         /* We must take a copy of the skb before we modify/replace the ipv6
 534          * header as the header could be used elsewhere
 535          */
 536         skb = skb_unshare(skb, GFP_ATOMIC);
 537         if (!skb)
 538                 return NET_XMIT_DROP;
 539
 540         /* Return values from setup_header()
 541          *  <0 - error, packet is dropped
 542          *   0 - this is a multicast packet
 543          *   1 - this is unicast packet
 544          */
 545         err = setup_header(skb, netdev, &addr, &addr_type);
 546         if (err < 0) {
 547                 kfree_skb(skb);
 548                 return NET_XMIT_DROP;
 549         }
 550
 551         if (err) {
 552                 if (lowpan_cb(skb)->chan) {
 553                         BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
 554                                netdev->name, &addr, addr_type,
 555                                &lowpan_cb(skb)->addr, lowpan_cb(skb)->chan);
 556                         err = send_pkt(lowpan_cb(skb)->chan, skb, netdev);
 557                 } else {
 558                         err = -ENOENT;
 559                 }
 560         } else {
 561                 /* We need to send the packet to every device behind this
 562                  * interface.
 563                  */
 564                 err = send_mcast_pkt(skb, netdev);
 565         }
 566
 567         dev_kfree_skb(skb);
 568
 569         if (err)
 570                 BT_DBG("ERROR: xmit failed (%d)", err);
 571
 572         return err < 0 ? NET_XMIT_DROP : err;
 573 }
 574
 575 static int bt_dev_init(struct net_device *dev)
 576 {
 577         netdev_lockdep_set_classes(dev);
 578
 579         return 0;
 580 }
 581
 582 static const struct net_device_ops netdev_ops = {
 583         .ndo_init               = bt_dev_init,
 584         .ndo_start_xmit         = bt_xmit,
 585 };
 586
 587 static const struct header_ops header_ops = {
 588         .create = header_create,
 589 };
 590
 591 static void netdev_setup(struct net_device *dev)
 592 {
 593         dev->hard_header_len    = 0;
 594         dev->needed_tailroom    = 0;
 595         dev->flags              = IFF_RUNNING | IFF_MULTICAST;
 596         dev->watchdog_timeo     = 0;
 597         dev->tx_queue_len       = DEFAULT_TX_QUEUE_LEN;
 598
 599         dev->netdev_ops         = &netdev_ops;
 600         dev->header_ops         = &header_ops;
 601         dev->needs_free_netdev  = true;
 602 }
 603
 604 static struct device_type bt_type = {
 605         .name   = "bluetooth",
 606 };
 607
 608 static void ifup(struct net_device *netdev)
 609 {
 610         int err;
 611
 612         rtnl_lock();
 613         err = dev_open(netdev, NULL);
 614         if (err < 0)
 615                 BT_INFO("iface %s cannot be opened (%d)", netdev->name, err);
 616         rtnl_unlock();
 617 }
 618
 619 static void ifdown(struct net_device *netdev)
 620 {
 621         rtnl_lock();
 622         dev_close(netdev);
 623         rtnl_unlock();
 624 }
 625
 626 static void do_notify_peers(struct work_struct *work)
 627 {
 628         struct lowpan_btle_dev *dev = container_of(work, struct lowpan_btle_dev,
 629                                                    notify_peers.work);
 630
 631         netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */
 632 }
 633
 634 static bool is_bt_6lowpan(struct hci_conn *hcon)
 635 {
 636         if (hcon->type != LE_LINK)
 637                 return false;
 638
 639         if (!enable_6lowpan)
 640                 return false;
 641
 642         return true;
 643 }
 644
 645 static struct l2cap_chan *chan_create(void)
 646 {
 647         struct l2cap_chan *chan;
 648
 649         chan = l2cap_chan_create();
 650         if (!chan)
 651                 return NULL;
 652
 653         l2cap_chan_set_defaults(chan);
 654
 655         chan->chan_type = L2CAP_CHAN_CONN_ORIENTED;
 656         chan->mode = L2CAP_MODE_LE_FLOWCTL;
 657         chan->imtu = 1280;
 658
 659         return chan;
 660 }
 661
 662 static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan,
 663                                         struct lowpan_btle_dev *dev,
 664                                         bool new_netdev)
 665 {
 666         struct lowpan_peer *peer;
 667
 668         peer = kzalloc(sizeof(*peer), GFP_ATOMIC);
 669         if (!peer)
 670                 return NULL;
 671
 672         peer->chan = chan;
 673         memset(&peer->peer_addr, 0, sizeof(struct in6_addr));
 674
 675         baswap((void *)peer->lladdr, &chan->dst);
 676
 677         lowpan_iphc_uncompress_eui48_lladdr(&peer->peer_addr, peer->lladdr);
 678
 679         spin_lock(&devices_lock);
 680         INIT_LIST_HEAD(&peer->list);
 681         peer_add(dev, peer);
 682         spin_unlock(&devices_lock);
 683
 684         /* Notifying peers about us needs to be done without locks held */
 685         if (new_netdev)
 686                 INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers);
 687         schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100));
 688
 689         return peer->chan;
 690 }
 691
 692 static int setup_netdev(struct l2cap_chan *chan, struct lowpan_btle_dev **dev)
 693 {
 694         struct net_device *netdev;
 695         int err = 0;
 696
 697         netdev = alloc_netdev(LOWPAN_PRIV_SIZE(sizeof(struct lowpan_btle_dev)),
 698                               IFACE_NAME_TEMPLATE, NET_NAME_UNKNOWN,
 699                               netdev_setup);
 700         if (!netdev)
 701                 return -ENOMEM;
 702
 703         netdev->addr_assign_type = NET_ADDR_PERM;
 704         baswap((void *)netdev->dev_addr, &chan->src);
 705
 706         netdev->netdev_ops = &netdev_ops;
 707         SET_NETDEV_DEV(netdev, &chan->conn->hcon->hdev->dev);
 708         SET_NETDEV_DEVTYPE(netdev, &bt_type);
 709
 710         *dev = lowpan_btle_dev(netdev);
 711         (*dev)->netdev = netdev;
 712         (*dev)->hdev = chan->conn->hcon->hdev;
 713         INIT_LIST_HEAD(&(*dev)->peers);
 714
 715         spin_lock(&devices_lock);
 716         INIT_LIST_HEAD(&(*dev)->list);
 717         list_add_rcu(&(*dev)->list, &bt_6lowpan_devices);
 718         spin_unlock(&devices_lock);
 719
 720         err = lowpan_register_netdev(netdev, LOWPAN_LLTYPE_BTLE);
 721         if (err < 0) {
 722                 BT_INFO("register_netdev failed %d", err);
 723                 spin_lock(&devices_lock);
 724                 list_del_rcu(&(*dev)->list);
 725                 spin_unlock(&devices_lock);
 726                 free_netdev(netdev);
 727                 goto out;
 728         }
 729
 730         BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d",
 731                netdev->ifindex, &chan->dst, chan->dst_type,
 732                &chan->src, chan->src_type);
 733         set_bit(__LINK_STATE_PRESENT, &netdev->state);
 734
 735         return 0;
 736
 737 out:
 738         return err;
 739 }
 740
 741 static inline void chan_ready_cb(struct l2cap_chan *chan)
 742 {
 743         struct lowpan_btle_dev *dev;
 744         bool new_netdev = false;
 745
 746         dev = lookup_dev(chan->conn);
 747
 748         BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev);
 749
 750         if (!dev) {
 751                 if (setup_netdev(chan, &dev) < 0) {
 752                         l2cap_chan_del(chan, -ENOENT);
 753                         return;
 754                 }
 755                 new_netdev = true;
 756         }
 757
 758         if (!try_module_get(THIS_MODULE))
 759                 return;
 760
 761         add_peer_chan(chan, dev, new_netdev);
 762         ifup(dev->netdev);
 763 }
 764
 765 static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan)
 766 {
 767         struct l2cap_chan *chan;
 768
 769         chan = chan_create();
 770         if (!chan)
 771                 return NULL;
 772
 773         chan->ops = pchan->ops;
 774
 775         BT_DBG("chan %p pchan %p", chan, pchan);
 776
 777         return chan;
 778 }
 779
 780 static void delete_netdev(struct work_struct *work)
 781 {
 782         struct lowpan_btle_dev *entry = container_of(work,
 783                                                      struct lowpan_btle_dev,
 784                                                      delete_netdev);
 785
 786         lowpan_unregister_netdev(entry->netdev);
 787
 788         /* The entry pointer is deleted by the netdev destructor. */
 789 }
 790
 791 static void chan_close_cb(struct l2cap_chan *chan)
 792 {
 793         struct lowpan_btle_dev *entry;
 794         struct lowpan_btle_dev *dev = NULL;
 795         struct lowpan_peer *peer;
 796         int err = -ENOENT;
 797         bool last = false, remove = true;
 798
 799         BT_DBG("chan %p conn %p", chan, chan->conn);
 800
 801         if (chan->conn && chan->conn->hcon) {
 802                 if (!is_bt_6lowpan(chan->conn->hcon))
 803                         return;
 804
 805                 /* If conn is set, then the netdev is also there and we should
 806                  * not remove it.
 807                  */
 808                 remove = false;
 809         }
 810
 811         spin_lock(&devices_lock);
 812
 813         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 814                 dev = lowpan_btle_dev(entry->netdev);
 815                 peer = __peer_lookup_chan(dev, chan);
 816                 if (peer) {
 817                         last = peer_del(dev, peer);
 818                         err = 0;
 819
 820                         BT_DBG("dev %p removing %speer %p", dev,
 821                                last ? "last " : "1 ", peer);
 822                         BT_DBG("chan %p orig refcnt %d", chan,
 823                                kref_read(&chan->kref));
 824
 825                         l2cap_chan_put(chan);
 826                         break;
 827                 }
 828         }
 829
 830         if (!err && last && dev && !atomic_read(&dev->peer_count)) {
 831                 spin_unlock(&devices_lock);
 832
 833                 cancel_delayed_work_sync(&dev->notify_peers);
 834
 835                 ifdown(dev->netdev);
 836
 837                 if (remove) {
 838                         INIT_WORK(&entry->delete_netdev, delete_netdev);
 839                         schedule_work(&entry->delete_netdev);
 840                 }
 841         } else {
 842                 spin_unlock(&devices_lock);
 843         }
 844
 845         return;
 846 }
 847
 848 static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err)
 849 {
 850         BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn,
 851                state_to_string(state), err);
 852 }
 853
 854 static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan,
 855                                          unsigned long hdr_len,
 856                                          unsigned long len, int nb)
 857 {
 858         /* Note that we must allocate using GFP_ATOMIC here as
 859          * this function is called originally from netdev hard xmit
 860          * function in atomic context.
 861          */
 862         return bt_skb_alloc(hdr_len + len, GFP_ATOMIC);
 863 }
 864
 865 static void chan_suspend_cb(struct l2cap_chan *chan)
 866 {
 867         struct lowpan_btle_dev *dev;
 868
 869         BT_DBG("chan %p suspend", chan);
 870
 871         dev = lookup_dev(chan->conn);
 872         if (!dev || !dev->netdev)
 873                 return;
 874
 875         netif_stop_queue(dev->netdev);
 876 }
 877
 878 static void chan_resume_cb(struct l2cap_chan *chan)
 879 {
 880         struct lowpan_btle_dev *dev;
 881
 882         BT_DBG("chan %p resume", chan);
 883
 884         dev = lookup_dev(chan->conn);
 885         if (!dev || !dev->netdev)
 886                 return;
 887
 888         netif_wake_queue(dev->netdev);
 889 }
 890
 891 static long chan_get_sndtimeo_cb(struct l2cap_chan *chan)
 892 {
 893         return L2CAP_CONN_TIMEOUT;
 894 }
 895
 896 static const struct l2cap_ops bt_6lowpan_chan_ops = {
 897         .name                   = "L2CAP 6LoWPAN channel",
 898         .new_connection         = chan_new_conn_cb,
 899         .recv                   = chan_recv_cb,
 900         .close                  = chan_close_cb,
 901         .state_change           = chan_state_change_cb,
 902         .ready                  = chan_ready_cb,
 903         .resume                 = chan_resume_cb,
 904         .suspend                = chan_suspend_cb,
 905         .get_sndtimeo           = chan_get_sndtimeo_cb,
 906         .alloc_skb              = chan_alloc_skb_cb,
 907
 908         .teardown               = l2cap_chan_no_teardown,
 909         .defer                  = l2cap_chan_no_defer,
 910         .set_shutdown           = l2cap_chan_no_set_shutdown,
 911 };
 912
 913 static inline __u8 bdaddr_type(__u8 type)
 914 {
 915         if (type == ADDR_LE_DEV_PUBLIC)
 916                 return BDADDR_LE_PUBLIC;
 917         else
 918                 return BDADDR_LE_RANDOM;
 919 }
 920
 921 static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type)
 922 {
 923         struct l2cap_chan *chan;
 924         int err;
 925
 926         chan = chan_create();
 927         if (!chan)
 928                 return -EINVAL;
 929
 930         chan->ops = &bt_6lowpan_chan_ops;
 931
 932         err = l2cap_chan_connect(chan, cpu_to_le16(L2CAP_PSM_IPSP), 0,
 933                                  addr, dst_type);
 934
 935         BT_DBG("chan %p err %d", chan, err);
 936         if (err < 0)
 937                 l2cap_chan_put(chan);
 938
 939         return err;
 940 }
 941
 942 static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type)
 943 {
 944         struct lowpan_peer *peer;
 945
 946         BT_DBG("conn %p dst type %d", conn, dst_type);
 947
 948         peer = lookup_peer(conn);
 949         if (!peer)
 950                 return -ENOENT;
 951
 952         BT_DBG("peer %p chan %p", peer, peer->chan);
 953
 954         l2cap_chan_close(peer->chan, ENOENT);
 955
 956         return 0;
 957 }
 958
 959 static struct l2cap_chan *bt_6lowpan_listen(void)
 960 {
 961         bdaddr_t *addr = BDADDR_ANY;
 962         struct l2cap_chan *chan;
 963         int err;
 964
 965         if (!enable_6lowpan)
 966                 return NULL;
 967
 968         chan = chan_create();
 969         if (!chan)
 970                 return NULL;
 971
 972         chan->ops = &bt_6lowpan_chan_ops;
 973         chan->state = BT_LISTEN;
 974         chan->src_type = BDADDR_LE_PUBLIC;
 975
 976         atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
 977
 978         BT_DBG("chan %p src type %d", chan, chan->src_type);
 979
 980         err = l2cap_add_psm(chan, addr, cpu_to_le16(L2CAP_PSM_IPSP));
 981         if (err) {
 982                 l2cap_chan_put(chan);
 983                 BT_ERR("psm cannot be added err %d", err);
 984                 return NULL;
 985         }
 986
 987         return chan;
 988 }
 989
 990 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type,
 991                           struct l2cap_conn **conn)
 992 {
 993         struct hci_conn *hcon;
 994         struct hci_dev *hdev;
 995         int n;
 996
 997         n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu",
 998                    &addr->b[5], &addr->b[4], &addr->b[3],
 999                    &addr->b[2], &addr->b[1], &addr->b[0],
1000                    addr_type);
1001
1002         if (n < 7)
1003                 return -EINVAL;
1004
1005         /* The LE_PUBLIC address type is ignored because of BDADDR_ANY */
1006         hdev = hci_get_route(addr, BDADDR_ANY, BDADDR_LE_PUBLIC);
1007         if (!hdev)
1008                 return -ENOENT;
1009
1010         hci_dev_lock(hdev);
1011         hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type);
1012         hci_dev_unlock(hdev);
1013
1014         if (!hcon)
1015                 return -ENOENT;
1016
1017         *conn = (struct l2cap_conn *)hcon->l2cap_data;
1018
1019         BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type);
1020
1021         return 0;
1022 }
1023
1024 static void disconnect_all_peers(void)
1025 {
1026         struct lowpan_btle_dev *entry;
1027         struct lowpan_peer *peer, *tmp_peer, *new_peer;
1028         struct list_head peers;
1029
1030         INIT_LIST_HEAD(&peers);
1031
1032         /* We make a separate list of peers as the close_cb() will
1033          * modify the device peers list so it is better not to mess
1034          * with the same list at the same time.
1035          */
1036
1037         rcu_read_lock();
1038
1039         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1040                 list_for_each_entry_rcu(peer, &entry->peers, list) {
1041                         new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC);
1042                         if (!new_peer)
1043                                 break;
1044
1045                         new_peer->chan = peer->chan;
1046                         INIT_LIST_HEAD(&new_peer->list);
1047
1048                         list_add(&new_peer->list, &peers);
1049                 }
1050         }
1051
1052         rcu_read_unlock();
1053
1054         spin_lock(&devices_lock);
1055         list_for_each_entry_safe(peer, tmp_peer, &peers, list) {
1056                 l2cap_chan_close(peer->chan, ENOENT);
1057
1058                 list_del_rcu(&peer->list);
1059                 kfree_rcu(peer, rcu);
1060         }
1061         spin_unlock(&devices_lock);
1062 }
1063
1064 struct set_enable {
1065         struct work_struct work;
1066         bool flag;
1067 };
1068
1069 static void do_enable_set(struct work_struct *work)
1070 {
1071         struct set_enable *set_enable = container_of(work,
1072                                                      struct set_enable, work);
1073
1074         if (!set_enable->flag || enable_6lowpan != set_enable->flag)
1075                 /* Disconnect existing connections if 6lowpan is
1076                  * disabled
1077                  */
1078                 disconnect_all_peers();
1079
1080         enable_6lowpan = set_enable->flag;
1081
1082         mutex_lock(&set_lock);
1083         if (listen_chan) {
1084                 l2cap_chan_close(listen_chan, 0);
1085                 l2cap_chan_put(listen_chan);
1086         }
1087
1088         listen_chan = bt_6lowpan_listen();
1089         mutex_unlock(&set_lock);
1090
1091         kfree(set_enable);
1092 }
1093
1094 static int lowpan_enable_set(void *data, u64 val)
1095 {
1096         struct set_enable *set_enable;
1097
1098         set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL);
1099         if (!set_enable)
1100                 return -ENOMEM;
1101
1102         set_enable->flag = !!val;
1103         INIT_WORK(&set_enable->work, do_enable_set);
1104
1105         schedule_work(&set_enable->work);
1106
1107         return 0;
1108 }
1109
1110 static int lowpan_enable_get(void *data, u64 *val)
1111 {
1112         *val = enable_6lowpan;
1113         return 0;
1114 }
1115
1116 DEFINE_DEBUGFS_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get,
1117                          lowpan_enable_set, "%llu\n");
1118
1119 static ssize_t lowpan_control_write(struct file *fp,
1120                                     const char __user *user_buffer,
1121                                     size_t count,
1122                                     loff_t *position)
1123 {
1124         char buf[32];
1125         size_t buf_size = min(count, sizeof(buf) - 1);
1126         int ret;
1127         bdaddr_t addr;
1128         u8 addr_type;
1129         struct l2cap_conn *conn = NULL;
1130
1131         if (copy_from_user(buf, user_buffer, buf_size))
1132                 return -EFAULT;
1133
1134         buf[buf_size] = '\0';
1135
1136         if (memcmp(buf, "connect ", 8) == 0) {
1137                 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn);
1138                 if (ret == -EINVAL)
1139                         return ret;
1140
1141                 mutex_lock(&set_lock);
1142                 if (listen_chan) {
1143                         l2cap_chan_close(listen_chan, 0);
1144                         l2cap_chan_put(listen_chan);
1145                         listen_chan = NULL;
1146                 }
1147                 mutex_unlock(&set_lock);
1148
1149                 if (conn) {
1150                         struct lowpan_peer *peer;
1151
1152                         if (!is_bt_6lowpan(conn->hcon))
1153                                 return -EINVAL;
1154
1155                         peer = lookup_peer(conn);
1156                         if (peer) {
1157                                 BT_DBG("6LoWPAN connection already exists");
1158                                 return -EALREADY;
1159                         }
1160
1161                         BT_DBG("conn %p dst %pMR type %d user %d", conn,
1162                                &conn->hcon->dst, conn->hcon->dst_type,
1163                                addr_type);
1164                 }
1165
1166                 ret = bt_6lowpan_connect(&addr, addr_type);
1167                 if (ret < 0)
1168                         return ret;
1169
1170                 return count;
1171         }
1172
1173         if (memcmp(buf, "disconnect ", 11) == 0) {
1174                 ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn);
1175                 if (ret < 0)
1176                         return ret;
1177
1178                 ret = bt_6lowpan_disconnect(conn, addr_type);
1179                 if (ret < 0)
1180                         return ret;
1181
1182                 return count;
1183         }
1184
1185         return count;
1186 }
1187
1188 static int lowpan_control_show(struct seq_file *f, void *ptr)
1189 {
1190         struct lowpan_btle_dev *entry;
1191         struct lowpan_peer *peer;
1192
1193         spin_lock(&devices_lock);
1194
1195         list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1196                 list_for_each_entry(peer, &entry->peers, list)
1197                         seq_printf(f, "%pMR (type %u)\n",
1198                                    &peer->chan->dst, peer->chan->dst_type);
1199         }
1200
1201         spin_unlock(&devices_lock);
1202
1203         return 0;
1204 }
1205
1206 static int lowpan_control_open(struct inode *inode, struct file *file)
1207 {
1208         return single_open(file, lowpan_control_show, inode->i_private);
1209 }
1210
1211 static const struct file_operations lowpan_control_fops = {
1212         .open           = lowpan_control_open,
1213         .read           = seq_read,
1214         .write          = lowpan_control_write,
1215         .llseek         = seq_lseek,
1216         .release        = single_release,
1217 };
1218
1219 static void disconnect_devices(void)
1220 {
1221         struct lowpan_btle_dev *entry, *tmp, *new_dev;
1222         struct list_head devices;
1223
1224         INIT_LIST_HEAD(&devices);
1225
1226         /* We make a separate list of devices because the unregister_netdev()
1227          * will call device_event() which will also want to modify the same
1228          * devices list.
1229          */
1230
1231         rcu_read_lock();
1232
1233         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1234                 new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC);
1235                 if (!new_dev)
1236                         break;
1237
1238                 new_dev->netdev = entry->netdev;
1239                 INIT_LIST_HEAD(&new_dev->list);
1240
1241                 list_add_rcu(&new_dev->list, &devices);
1242         }
1243
1244         rcu_read_unlock();
1245
1246         list_for_each_entry_safe(entry, tmp, &devices, list) {
1247                 ifdown(entry->netdev);
1248                 BT_DBG("Unregistering netdev %s %p",
1249                        entry->netdev->name, entry->netdev);
1250                 lowpan_unregister_netdev(entry->netdev);
1251                 kfree(entry);
1252         }
1253 }
1254
1255 static int device_event(struct notifier_block *unused,
1256                         unsigned long event, void *ptr)
1257 {
1258         struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
1259         struct lowpan_btle_dev *entry;
1260
1261         if (netdev->type != ARPHRD_6LOWPAN)
1262                 return NOTIFY_DONE;
1263
1264         switch (event) {
1265         case NETDEV_UNREGISTER:
1266                 spin_lock(&devices_lock);
1267                 list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1268                         if (entry->netdev == netdev) {
1269                                 BT_DBG("Unregistered netdev %s %p",
1270                                        netdev->name, netdev);
1271                                 list_del(&entry->list);
1272                                 break;
1273                         }
1274                 }
1275                 spin_unlock(&devices_lock);
1276                 break;
1277         }
1278
1279         return NOTIFY_DONE;
1280 }
1281
1282 static struct notifier_block bt_6lowpan_dev_notifier = {
1283         .notifier_call = device_event,
1284 };
1285
1286 static int __init bt_6lowpan_init(void)
1287 {
1288         lowpan_enable_debugfs = debugfs_create_file_unsafe("6lowpan_enable",
1289                                                            0644, bt_debugfs,
1290                                                            NULL,
1291                                                            &lowpan_enable_fops);
1292         lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644,
1293                                                      bt_debugfs, NULL,
1294                                                      &lowpan_control_fops);
1295
1296         return register_netdevice_notifier(&bt_6lowpan_dev_notifier);
1297 }
1298
1299 static void __exit bt_6lowpan_exit(void)
1300 {
1301         debugfs_remove(lowpan_enable_debugfs);
1302         debugfs_remove(lowpan_control_debugfs);
1303
1304         if (listen_chan) {
1305                 l2cap_chan_close(listen_chan, 0);
1306                 l2cap_chan_put(listen_chan);
1307         }
1308
1309         disconnect_devices();
1310
1311         unregister_netdevice_notifier(&bt_6lowpan_dev_notifier);
1312 }
1313
1314 module_init(bt_6lowpan_init);
1315 module_exit(bt_6lowpan_exit);
1316
1317 MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>");
1318 MODULE_DESCRIPTION("Bluetooth 6LoWPAN");
1319 MODULE_VERSION(VERSION);
1320 MODULE_LICENSE("GPL");