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