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
  24 #include <net/bluetooth/bluetooth.h>
  25 #include <net/bluetooth/hci_core.h>
  26 #include <net/bluetooth/l2cap.h>
  27
  28 #include <net/6lowpan.h> /* for the compression support */
  29
  30 #define VERSION "0.1"
  31
  32 static struct dentry *lowpan_enable_debugfs;
  33 static struct dentry *lowpan_control_debugfs;
  34
  35 #define IFACE_NAME_TEMPLATE "bt%d"
  36
  37 struct skb_cb {
  38         struct in6_addr addr;
  39         struct in6_addr gw;
  40         struct l2cap_chan *chan;
  41         int status;
  42 };
  43 #define lowpan_cb(skb) ((struct skb_cb *)((skb)->cb))
  44
  45 /* The devices list contains those devices that we are acting
  46  * as a proxy. The BT 6LoWPAN device is a virtual device that
  47  * connects to the Bluetooth LE device. The real connection to
  48  * BT device is done via l2cap layer. There exists one
  49  * virtual device / one BT 6LoWPAN network (=hciX device).
  50  * The list contains struct lowpan_dev elements.
  51  */
  52 static LIST_HEAD(bt_6lowpan_devices);
  53 static DEFINE_SPINLOCK(devices_lock);
  54
  55 static bool enable_6lowpan;
  56
  57 /* We are listening incoming connections via this channel
  58  */
  59 static struct l2cap_chan *listen_chan;
  60
  61 struct lowpan_peer {
  62         struct list_head list;
  63         struct rcu_head rcu;
  64         struct l2cap_chan *chan;
  65
  66         /* peer addresses in various formats */
  67         unsigned char eui64_addr[EUI64_ADDR_LEN];
  68         struct in6_addr peer_addr;
  69 };
  70
  71 struct lowpan_dev {
  72         struct list_head list;
  73
  74         struct hci_dev *hdev;
  75         struct net_device *netdev;
  76         struct list_head peers;
  77         atomic_t peer_count; /* number of items in peers list */
  78
  79         struct work_struct delete_netdev;
  80         struct delayed_work notify_peers;
  81 };
  82
  83 static inline struct lowpan_dev *lowpan_dev(const struct net_device *netdev)
  84 {
  85         return (struct lowpan_dev *)lowpan_priv(netdev)->priv;
  86 }
  87
  88 static inline void peer_add(struct lowpan_dev *dev, struct lowpan_peer *peer)
  89 {
  90         list_add_rcu(&peer->list, &dev->peers);
  91         atomic_inc(&dev->peer_count);
  92 }
  93
  94 static inline bool peer_del(struct lowpan_dev *dev, struct lowpan_peer *peer)
  95 {
  96         list_del_rcu(&peer->list);
  97         kfree_rcu(peer, rcu);
  98
  99         module_put(THIS_MODULE);
 100
 101         if (atomic_dec_and_test(&dev->peer_count)) {
 102                 BT_DBG("last peer");
 103                 return true;
 104         }
 105
 106         return false;
 107 }
 108
 109 static inline struct lowpan_peer *peer_lookup_ba(struct lowpan_dev *dev,
 110                                                  bdaddr_t *ba, __u8 type)
 111 {
 112         struct lowpan_peer *peer;
 113
 114         BT_DBG("peers %d addr %pMR type %d", atomic_read(&dev->peer_count),
 115                ba, type);
 116
 117         rcu_read_lock();
 118
 119         list_for_each_entry_rcu(peer, &dev->peers, list) {
 120                 BT_DBG("dst addr %pMR dst type %d",
 121                        &peer->chan->dst, peer->chan->dst_type);
 122
 123                 if (bacmp(&peer->chan->dst, ba))
 124                         continue;
 125
 126                 if (type == peer->chan->dst_type) {
 127                         rcu_read_unlock();
 128                         return peer;
 129                 }
 130         }
 131
 132         rcu_read_unlock();
 133
 134         return NULL;
 135 }
 136
 137 static inline struct lowpan_peer *__peer_lookup_chan(struct lowpan_dev *dev,
 138                                                      struct l2cap_chan *chan)
 139 {
 140         struct lowpan_peer *peer;
 141
 142         list_for_each_entry_rcu(peer, &dev->peers, list) {
 143                 if (peer->chan == chan)
 144                         return peer;
 145         }
 146
 147         return NULL;
 148 }
 149
 150 static inline struct lowpan_peer *__peer_lookup_conn(struct lowpan_dev *dev,
 151                                                      struct l2cap_conn *conn)
 152 {
 153         struct lowpan_peer *peer;
 154
 155         list_for_each_entry_rcu(peer, &dev->peers, list) {
 156                 if (peer->chan->conn == conn)
 157                         return peer;
 158         }
 159
 160         return NULL;
 161 }
 162
 163 static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_dev *dev,
 164                                                   struct in6_addr *daddr,
 165                                                   struct sk_buff *skb)
 166 {
 167         struct lowpan_peer *peer;
 168         struct in6_addr *nexthop;
 169         struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
 170         int count = atomic_read(&dev->peer_count);
 171
 172         BT_DBG("peers %d addr %pI6c rt %p", count, daddr, rt);
 173
 174         /* If we have multiple 6lowpan peers, then check where we should
 175          * send the packet. If only one peer exists, then we can send the
 176          * packet right away.
 177          */
 178         if (count == 1) {
 179                 rcu_read_lock();
 180                 peer = list_first_or_null_rcu(&dev->peers, struct lowpan_peer,
 181                                               list);
 182                 rcu_read_unlock();
 183                 return peer;
 184         }
 185
 186         if (!rt) {
 187                 nexthop = &lowpan_cb(skb)->gw;
 188
 189                 if (ipv6_addr_any(nexthop))
 190                         return NULL;
 191         } else {
 192                 nexthop = rt6_nexthop(rt, daddr);
 193
 194                 /* We need to remember the address because it is needed
 195                  * by bt_xmit() when sending the packet. In bt_xmit(), the
 196                  * destination routing info is not set.
 197                  */
 198                 memcpy(&lowpan_cb(skb)->gw, nexthop, sizeof(struct in6_addr));
 199         }
 200
 201         BT_DBG("gw %pI6c", nexthop);
 202
 203         rcu_read_lock();
 204
 205         list_for_each_entry_rcu(peer, &dev->peers, list) {
 206                 BT_DBG("dst addr %pMR dst type %d ip %pI6c",
 207                        &peer->chan->dst, peer->chan->dst_type,
 208                        &peer->peer_addr);
 209
 210                 if (!ipv6_addr_cmp(&peer->peer_addr, nexthop)) {
 211                         rcu_read_unlock();
 212                         return peer;
 213                 }
 214         }
 215
 216         rcu_read_unlock();
 217
 218         return NULL;
 219 }
 220
 221 static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn)
 222 {
 223         struct lowpan_dev *entry;
 224         struct lowpan_peer *peer = NULL;
 225
 226         rcu_read_lock();
 227
 228         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 229                 peer = __peer_lookup_conn(entry, conn);
 230                 if (peer)
 231                         break;
 232         }
 233
 234         rcu_read_unlock();
 235
 236         return peer;
 237 }
 238
 239 static struct lowpan_dev *lookup_dev(struct l2cap_conn *conn)
 240 {
 241         struct lowpan_dev *entry;
 242         struct lowpan_dev *dev = NULL;
 243
 244         rcu_read_lock();
 245
 246         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 247                 if (conn->hcon->hdev == entry->hdev) {
 248                         dev = entry;
 249                         break;
 250                 }
 251         }
 252
 253         rcu_read_unlock();
 254
 255         return dev;
 256 }
 257
 258 static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev)
 259 {
 260         struct sk_buff *skb_cp;
 261
 262         skb_cp = skb_copy(skb, GFP_ATOMIC);
 263         if (!skb_cp)
 264                 return NET_RX_DROP;
 265
 266         return netif_rx_ni(skb_cp);
 267 }
 268
 269 static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev,
 270                            struct l2cap_chan *chan)
 271 {
 272         const u8 *saddr, *daddr;
 273         struct lowpan_dev *dev;
 274         struct lowpan_peer *peer;
 275
 276         dev = lowpan_dev(netdev);
 277
 278         rcu_read_lock();
 279         peer = __peer_lookup_chan(dev, chan);
 280         rcu_read_unlock();
 281         if (!peer)
 282                 return -EINVAL;
 283
 284         saddr = peer->eui64_addr;
 285         daddr = dev->netdev->dev_addr;
 286
 287         return lowpan_header_decompress(skb, netdev, daddr, saddr);
 288 }
 289
 290 static int recv_pkt(struct sk_buff *skb, struct net_device *dev,
 291                     struct l2cap_chan *chan)
 292 {
 293         struct sk_buff *local_skb;
 294         int ret;
 295
 296         if (!netif_running(dev))
 297                 goto drop;
 298
 299         if (dev->type != ARPHRD_6LOWPAN || !skb->len)
 300                 goto drop;
 301
 302         skb_reset_network_header(skb);
 303
 304         skb = skb_share_check(skb, GFP_ATOMIC);
 305         if (!skb)
 306                 goto drop;
 307
 308         /* check that it's our buffer */
 309         if (lowpan_is_ipv6(*skb_network_header(skb))) {
 310                 /* Pull off the 1-byte of 6lowpan header. */
 311                 skb_pull(skb, 1);
 312
 313                 /* Copy the packet so that the IPv6 header is
 314                  * properly aligned.
 315                  */
 316                 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
 317                                             skb_tailroom(skb), GFP_ATOMIC);
 318                 if (!local_skb)
 319                         goto drop;
 320
 321                 local_skb->protocol = htons(ETH_P_IPV6);
 322                 local_skb->pkt_type = PACKET_HOST;
 323                 local_skb->dev = dev;
 324
 325                 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
 326
 327                 if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) {
 328                         kfree_skb(local_skb);
 329                         goto drop;
 330                 }
 331
 332                 dev->stats.rx_bytes += skb->len;
 333                 dev->stats.rx_packets++;
 334
 335                 consume_skb(local_skb);
 336                 consume_skb(skb);
 337         } else if (lowpan_is_iphc(*skb_network_header(skb))) {
 338                 local_skb = skb_clone(skb, GFP_ATOMIC);
 339                 if (!local_skb)
 340                         goto drop;
 341
 342                 local_skb->dev = dev;
 343
 344                 ret = iphc_decompress(local_skb, dev, chan);
 345                 if (ret < 0) {
 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                 goto drop;
 366         }
 367
 368         return NET_RX_SUCCESS;
 369
 370 drop:
 371         dev->stats.rx_dropped++;
 372         return NET_RX_DROP;
 373 }
 374
 375 /* Packet from BT LE device */
 376 static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
 377 {
 378         struct lowpan_dev *dev;
 379         struct lowpan_peer *peer;
 380         int err;
 381
 382         peer = lookup_peer(chan->conn);
 383         if (!peer)
 384                 return -ENOENT;
 385
 386         dev = lookup_dev(chan->conn);
 387         if (!dev || !dev->netdev)
 388                 return -ENOENT;
 389
 390         err = recv_pkt(skb, dev->netdev, chan);
 391         if (err) {
 392                 BT_DBG("recv pkt %d", err);
 393                 err = -EAGAIN;
 394         }
 395
 396         return err;
 397 }
 398
 399 static u8 get_addr_type_from_eui64(u8 byte)
 400 {
 401         /* Is universal(0) or local(1) bit */
 402         return ((byte & 0x02) ? BDADDR_LE_RANDOM : BDADDR_LE_PUBLIC);
 403 }
 404
 405 static void copy_to_bdaddr(struct in6_addr *ip6_daddr, bdaddr_t *addr)
 406 {
 407         u8 *eui64 = ip6_daddr->s6_addr + 8;
 408
 409         addr->b[0] = eui64[7];
 410         addr->b[1] = eui64[6];
 411         addr->b[2] = eui64[5];
 412         addr->b[3] = eui64[2];
 413         addr->b[4] = eui64[1];
 414         addr->b[5] = eui64[0];
 415 }
 416
 417 static void convert_dest_bdaddr(struct in6_addr *ip6_daddr,
 418                                 bdaddr_t *addr, u8 *addr_type)
 419 {
 420         copy_to_bdaddr(ip6_daddr, addr);
 421
 422         /* We need to toggle the U/L bit that we got from IPv6 address
 423          * so that we get the proper address and type of the BD address.
 424          */
 425         addr->b[5] ^= 0x02;
 426
 427         *addr_type = get_addr_type_from_eui64(addr->b[5]);
 428 }
 429
 430 static int setup_header(struct sk_buff *skb, struct net_device *netdev,
 431                         bdaddr_t *peer_addr, u8 *peer_addr_type)
 432 {
 433         struct in6_addr ipv6_daddr;
 434         struct lowpan_dev *dev;
 435         struct lowpan_peer *peer;
 436         bdaddr_t addr, *any = BDADDR_ANY;
 437         u8 *daddr = any->b;
 438         int err, status = 0;
 439
 440         dev = lowpan_dev(netdev);
 441
 442         memcpy(&ipv6_daddr, &lowpan_cb(skb)->addr, sizeof(ipv6_daddr));
 443
 444         if (ipv6_addr_is_multicast(&ipv6_daddr)) {
 445                 lowpan_cb(skb)->chan = NULL;
 446         } else {
 447                 u8 addr_type;
 448
 449                 /* Get destination BT device from skb.
 450                  * If there is no such peer then discard the packet.
 451                  */
 452                 convert_dest_bdaddr(&ipv6_daddr, &addr, &addr_type);
 453
 454                 BT_DBG("dest addr %pMR type %d IP %pI6c", &addr,
 455                        addr_type, &ipv6_daddr);
 456
 457                 peer = peer_lookup_ba(dev, &addr, addr_type);
 458                 if (!peer) {
 459                         /* The packet might be sent to 6lowpan interface
 460                          * because of routing (either via default route
 461                          * or user set route) so get peer according to
 462                          * the destination address.
 463                          */
 464                         peer = peer_lookup_dst(dev, &ipv6_daddr, skb);
 465                         if (!peer) {
 466                                 BT_DBG("no such peer %pMR found", &addr);
 467                                 return -ENOENT;
 468                         }
 469                 }
 470
 471                 daddr = peer->eui64_addr;
 472                 *peer_addr = addr;
 473                 *peer_addr_type = addr_type;
 474                 lowpan_cb(skb)->chan = peer->chan;
 475
 476                 status = 1;
 477         }
 478
 479         lowpan_header_compress(skb, netdev, daddr, dev->netdev->dev_addr);
 480
 481         err = dev_hard_header(skb, netdev, ETH_P_IPV6, NULL, NULL, 0);
 482         if (err < 0)
 483                 return err;
 484
 485         return status;
 486 }
 487
 488 static int header_create(struct sk_buff *skb, struct net_device *netdev,
 489                          unsigned short type, const void *_daddr,
 490                          const void *_saddr, unsigned int len)
 491 {
 492         struct ipv6hdr *hdr;
 493
 494         if (type != ETH_P_IPV6)
 495                 return -EINVAL;
 496
 497         hdr = ipv6_hdr(skb);
 498
 499         memcpy(&lowpan_cb(skb)->addr, &hdr->daddr, sizeof(struct in6_addr));
 500
 501         return 0;
 502 }
 503
 504 /* Packet to BT LE device */
 505 static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb,
 506                     struct net_device *netdev)
 507 {
 508         struct msghdr msg;
 509         struct kvec iv;
 510         int err;
 511
 512         /* Remember the skb so that we can send EAGAIN to the caller if
 513          * we run out of credits.
 514          */
 515         chan->data = skb;
 516
 517         iv.iov_base = skb->data;
 518         iv.iov_len = skb->len;
 519
 520         memset(&msg, 0, sizeof(msg));
 521         iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, &iv, 1, skb->len);
 522
 523         err = l2cap_chan_send(chan, &msg, skb->len);
 524         if (err > 0) {
 525                 netdev->stats.tx_bytes += err;
 526                 netdev->stats.tx_packets++;
 527                 return 0;
 528         }
 529
 530         if (!err)
 531                 err = lowpan_cb(skb)->status;
 532
 533         if (err < 0) {
 534                 if (err == -EAGAIN)
 535                         netdev->stats.tx_dropped++;
 536                 else
 537                         netdev->stats.tx_errors++;
 538         }
 539
 540         return err;
 541 }
 542
 543 static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev)
 544 {
 545         struct sk_buff *local_skb;
 546         struct lowpan_dev *entry;
 547         int err = 0;
 548
 549         rcu_read_lock();
 550
 551         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 552                 struct lowpan_peer *pentry;
 553                 struct lowpan_dev *dev;
 554
 555                 if (entry->netdev != netdev)
 556                         continue;
 557
 558                 dev = lowpan_dev(entry->netdev);
 559
 560                 list_for_each_entry_rcu(pentry, &dev->peers, list) {
 561                         int ret;
 562
 563                         local_skb = skb_clone(skb, GFP_ATOMIC);
 564
 565                         BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
 566                                netdev->name,
 567                                &pentry->chan->dst, pentry->chan->dst_type,
 568                                &pentry->peer_addr, pentry->chan);
 569                         ret = send_pkt(pentry->chan, local_skb, netdev);
 570                         if (ret < 0)
 571                                 err = ret;
 572
 573                         kfree_skb(local_skb);
 574                 }
 575         }
 576
 577         rcu_read_unlock();
 578
 579         return err;
 580 }
 581
 582 static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev)
 583 {
 584         int err = 0;
 585         bdaddr_t addr;
 586         u8 addr_type;
 587
 588         /* We must take a copy of the skb before we modify/replace the ipv6
 589          * header as the header could be used elsewhere
 590          */
 591         skb = skb_unshare(skb, GFP_ATOMIC);
 592         if (!skb)
 593                 return NET_XMIT_DROP;
 594
 595         /* Return values from setup_header()
 596          *  <0 - error, packet is dropped
 597          *   0 - this is a multicast packet
 598          *   1 - this is unicast packet
 599          */
 600         err = setup_header(skb, netdev, &addr, &addr_type);
 601         if (err < 0) {
 602                 kfree_skb(skb);
 603                 return NET_XMIT_DROP;
 604         }
 605
 606         if (err) {
 607                 if (lowpan_cb(skb)->chan) {
 608                         BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
 609                                netdev->name, &addr, addr_type,
 610                                &lowpan_cb(skb)->addr, lowpan_cb(skb)->chan);
 611                         err = send_pkt(lowpan_cb(skb)->chan, skb, netdev);
 612                 } else {
 613                         err = -ENOENT;
 614                 }
 615         } else {
 616                 /* We need to send the packet to every device behind this
 617                  * interface.
 618                  */
 619                 err = send_mcast_pkt(skb, netdev);
 620         }
 621
 622         dev_kfree_skb(skb);
 623
 624         if (err)
 625                 BT_DBG("ERROR: xmit failed (%d)", err);
 626
 627         return err < 0 ? NET_XMIT_DROP : err;
 628 }
 629
 630 static struct lock_class_key bt_tx_busylock;
 631 static struct lock_class_key bt_netdev_xmit_lock_key;
 632
 633 static void bt_set_lockdep_class_one(struct net_device *dev,
 634                                      struct netdev_queue *txq,
 635                                      void *_unused)
 636 {
 637         lockdep_set_class(&txq->_xmit_lock, &bt_netdev_xmit_lock_key);
 638 }
 639
 640 static int bt_dev_init(struct net_device *dev)
 641 {
 642         netdev_for_each_tx_queue(dev, bt_set_lockdep_class_one, NULL);
 643         dev->qdisc_tx_busylock = &bt_tx_busylock;
 644
 645         return 0;
 646 }
 647
 648 static const struct net_device_ops netdev_ops = {
 649         .ndo_init               = bt_dev_init,
 650         .ndo_start_xmit         = bt_xmit,
 651 };
 652
 653 static struct header_ops header_ops = {
 654         .create = header_create,
 655 };
 656
 657 static void netdev_setup(struct net_device *dev)
 658 {
 659         dev->hard_header_len    = 0;
 660         dev->needed_tailroom    = 0;
 661         dev->flags              = IFF_RUNNING | IFF_POINTOPOINT |
 662                                   IFF_MULTICAST;
 663         dev->watchdog_timeo     = 0;
 664
 665         dev->netdev_ops         = &netdev_ops;
 666         dev->header_ops         = &header_ops;
 667         dev->destructor         = free_netdev;
 668 }
 669
 670 static struct device_type bt_type = {
 671         .name   = "bluetooth",
 672 };
 673
 674 static void set_addr(u8 *eui, u8 *addr, u8 addr_type)
 675 {
 676         /* addr is the BT address in little-endian format */
 677         eui[0] = addr[5];
 678         eui[1] = addr[4];
 679         eui[2] = addr[3];
 680         eui[3] = 0xFF;
 681         eui[4] = 0xFE;
 682         eui[5] = addr[2];
 683         eui[6] = addr[1];
 684         eui[7] = addr[0];
 685
 686         /* Universal/local bit set, BT 6lowpan draft ch. 3.2.1 */
 687         if (addr_type == BDADDR_LE_PUBLIC)
 688                 eui[0] &= ~0x02;
 689         else
 690                 eui[0] |= 0x02;
 691
 692         BT_DBG("type %d addr %*phC", addr_type, 8, eui);
 693 }
 694
 695 static void set_dev_addr(struct net_device *netdev, bdaddr_t *addr,
 696                          u8 addr_type)
 697 {
 698         netdev->addr_assign_type = NET_ADDR_PERM;
 699         set_addr(netdev->dev_addr, addr->b, addr_type);
 700 }
 701
 702 static void ifup(struct net_device *netdev)
 703 {
 704         int err;
 705
 706         rtnl_lock();
 707         err = dev_open(netdev);
 708         if (err < 0)
 709                 BT_INFO("iface %s cannot be opened (%d)", netdev->name, err);
 710         rtnl_unlock();
 711 }
 712
 713 static void ifdown(struct net_device *netdev)
 714 {
 715         int err;
 716
 717         rtnl_lock();
 718         err = dev_close(netdev);
 719         if (err < 0)
 720                 BT_INFO("iface %s cannot be closed (%d)", netdev->name, err);
 721         rtnl_unlock();
 722 }
 723
 724 static void do_notify_peers(struct work_struct *work)
 725 {
 726         struct lowpan_dev *dev = container_of(work, struct lowpan_dev,
 727                                               notify_peers.work);
 728
 729         netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */
 730 }
 731
 732 static bool is_bt_6lowpan(struct hci_conn *hcon)
 733 {
 734         if (hcon->type != LE_LINK)
 735                 return false;
 736
 737         if (!enable_6lowpan)
 738                 return false;
 739
 740         return true;
 741 }
 742
 743 static struct l2cap_chan *chan_create(void)
 744 {
 745         struct l2cap_chan *chan;
 746
 747         chan = l2cap_chan_create();
 748         if (!chan)
 749                 return NULL;
 750
 751         l2cap_chan_set_defaults(chan);
 752
 753         chan->chan_type = L2CAP_CHAN_CONN_ORIENTED;
 754         chan->mode = L2CAP_MODE_LE_FLOWCTL;
 755         chan->imtu = 1280;
 756
 757         return chan;
 758 }
 759
 760 static void set_ip_addr_bits(u8 addr_type, u8 *addr)
 761 {
 762         if (addr_type == BDADDR_LE_PUBLIC)
 763                 *addr |= 0x02;
 764         else
 765                 *addr &= ~0x02;
 766 }
 767
 768 static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan,
 769                                         struct lowpan_dev *dev)
 770 {
 771         struct lowpan_peer *peer;
 772
 773         peer = kzalloc(sizeof(*peer), GFP_ATOMIC);
 774         if (!peer)
 775                 return NULL;
 776
 777         peer->chan = chan;
 778         memset(&peer->peer_addr, 0, sizeof(struct in6_addr));
 779
 780         /* RFC 2464 ch. 5 */
 781         peer->peer_addr.s6_addr[0] = 0xFE;
 782         peer->peer_addr.s6_addr[1] = 0x80;
 783         set_addr((u8 *)&peer->peer_addr.s6_addr + 8, chan->dst.b,
 784                  chan->dst_type);
 785
 786         memcpy(&peer->eui64_addr, (u8 *)&peer->peer_addr.s6_addr + 8,
 787                EUI64_ADDR_LEN);
 788
 789         /* IPv6 address needs to have the U/L bit set properly so toggle
 790          * it back here.
 791          */
 792         set_ip_addr_bits(chan->dst_type, (u8 *)&peer->peer_addr.s6_addr + 8);
 793
 794         spin_lock(&devices_lock);
 795         INIT_LIST_HEAD(&peer->list);
 796         peer_add(dev, peer);
 797         spin_unlock(&devices_lock);
 798
 799         /* Notifying peers about us needs to be done without locks held */
 800         INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers);
 801         schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100));
 802
 803         return peer->chan;
 804 }
 805
 806 static int setup_netdev(struct l2cap_chan *chan, struct lowpan_dev **dev)
 807 {
 808         struct net_device *netdev;
 809         int err = 0;
 810
 811         netdev = alloc_netdev(LOWPAN_PRIV_SIZE(sizeof(struct lowpan_dev)),
 812                               IFACE_NAME_TEMPLATE, NET_NAME_UNKNOWN,
 813                               netdev_setup);
 814         if (!netdev)
 815                 return -ENOMEM;
 816
 817         set_dev_addr(netdev, &chan->src, chan->src_type);
 818
 819         netdev->netdev_ops = &netdev_ops;
 820         SET_NETDEV_DEV(netdev, &chan->conn->hcon->hdev->dev);
 821         SET_NETDEV_DEVTYPE(netdev, &bt_type);
 822
 823         *dev = lowpan_dev(netdev);
 824         (*dev)->netdev = netdev;
 825         (*dev)->hdev = chan->conn->hcon->hdev;
 826         INIT_LIST_HEAD(&(*dev)->peers);
 827
 828         spin_lock(&devices_lock);
 829         INIT_LIST_HEAD(&(*dev)->list);
 830         list_add_rcu(&(*dev)->list, &bt_6lowpan_devices);
 831         spin_unlock(&devices_lock);
 832
 833         err = lowpan_register_netdev(netdev, LOWPAN_LLTYPE_BTLE);
 834         if (err < 0) {
 835                 BT_INFO("register_netdev failed %d", err);
 836                 spin_lock(&devices_lock);
 837                 list_del_rcu(&(*dev)->list);
 838                 spin_unlock(&devices_lock);
 839                 free_netdev(netdev);
 840                 goto out;
 841         }
 842
 843         BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d",
 844                netdev->ifindex, &chan->dst, chan->dst_type,
 845                &chan->src, chan->src_type);
 846         set_bit(__LINK_STATE_PRESENT, &netdev->state);
 847
 848         return 0;
 849
 850 out:
 851         return err;
 852 }
 853
 854 static inline void chan_ready_cb(struct l2cap_chan *chan)
 855 {
 856         struct lowpan_dev *dev;
 857
 858         dev = lookup_dev(chan->conn);
 859
 860         BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev);
 861
 862         if (!dev) {
 863                 if (setup_netdev(chan, &dev) < 0) {
 864                         l2cap_chan_del(chan, -ENOENT);
 865                         return;
 866                 }
 867         }
 868
 869         if (!try_module_get(THIS_MODULE))
 870                 return;
 871
 872         add_peer_chan(chan, dev);
 873         ifup(dev->netdev);
 874 }
 875
 876 static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan)
 877 {
 878         struct l2cap_chan *chan;
 879
 880         chan = chan_create();
 881         if (!chan)
 882                 return NULL;
 883
 884         chan->ops = pchan->ops;
 885
 886         BT_DBG("chan %p pchan %p", chan, pchan);
 887
 888         return chan;
 889 }
 890
 891 static void delete_netdev(struct work_struct *work)
 892 {
 893         struct lowpan_dev *entry = container_of(work, struct lowpan_dev,
 894                                                 delete_netdev);
 895
 896         lowpan_unregister_netdev(entry->netdev);
 897
 898         /* The entry pointer is deleted by the netdev destructor. */
 899 }
 900
 901 static void chan_close_cb(struct l2cap_chan *chan)
 902 {
 903         struct lowpan_dev *entry;
 904         struct lowpan_dev *dev = NULL;
 905         struct lowpan_peer *peer;
 906         int err = -ENOENT;
 907         bool last = false, remove = true;
 908
 909         BT_DBG("chan %p conn %p", chan, chan->conn);
 910
 911         if (chan->conn && chan->conn->hcon) {
 912                 if (!is_bt_6lowpan(chan->conn->hcon))
 913                         return;
 914
 915                 /* If conn is set, then the netdev is also there and we should
 916                  * not remove it.
 917                  */
 918                 remove = false;
 919         }
 920
 921         spin_lock(&devices_lock);
 922
 923         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 924                 dev = lowpan_dev(entry->netdev);
 925                 peer = __peer_lookup_chan(dev, chan);
 926                 if (peer) {
 927                         last = peer_del(dev, peer);
 928                         err = 0;
 929
 930                         BT_DBG("dev %p removing %speer %p", dev,
 931                                last ? "last " : "1 ", peer);
 932                         BT_DBG("chan %p orig refcnt %d", chan,
 933                                atomic_read(&chan->kref.refcount));
 934
 935                         l2cap_chan_put(chan);
 936                         break;
 937                 }
 938         }
 939
 940         if (!err && last && dev && !atomic_read(&dev->peer_count)) {
 941                 spin_unlock(&devices_lock);
 942
 943                 cancel_delayed_work_sync(&dev->notify_peers);
 944
 945                 ifdown(dev->netdev);
 946
 947                 if (remove) {
 948                         INIT_WORK(&entry->delete_netdev, delete_netdev);
 949                         schedule_work(&entry->delete_netdev);
 950                 }
 951         } else {
 952                 spin_unlock(&devices_lock);
 953         }
 954
 955         return;
 956 }
 957
 958 static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err)
 959 {
 960         BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn,
 961                state_to_string(state), err);
 962 }
 963
 964 static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan,
 965                                          unsigned long hdr_len,
 966                                          unsigned long len, int nb)
 967 {
 968         /* Note that we must allocate using GFP_ATOMIC here as
 969          * this function is called originally from netdev hard xmit
 970          * function in atomic context.
 971          */
 972         return bt_skb_alloc(hdr_len + len, GFP_ATOMIC);
 973 }
 974
 975 static void chan_suspend_cb(struct l2cap_chan *chan)
 976 {
 977         struct sk_buff *skb = chan->data;
 978
 979         BT_DBG("chan %p conn %p skb %p", chan, chan->conn, skb);
 980
 981         if (!skb)
 982                 return;
 983
 984         lowpan_cb(skb)->status = -EAGAIN;
 985 }
 986
 987 static void chan_resume_cb(struct l2cap_chan *chan)
 988 {
 989         struct sk_buff *skb = chan->data;
 990
 991         BT_DBG("chan %p conn %p skb %p", chan, chan->conn, skb);
 992
 993         if (!skb)
 994                 return;
 995
 996         lowpan_cb(skb)->status = 0;
 997 }
 998
 999 static long chan_get_sndtimeo_cb(struct l2cap_chan *chan)
1000 {
1001         return L2CAP_CONN_TIMEOUT;
1002 }
1003
1004 static const struct l2cap_ops bt_6lowpan_chan_ops = {
1005         .name                   = "L2CAP 6LoWPAN channel",
1006         .new_connection         = chan_new_conn_cb,
1007         .recv                   = chan_recv_cb,
1008         .close                  = chan_close_cb,
1009         .state_change           = chan_state_change_cb,
1010         .ready                  = chan_ready_cb,
1011         .resume                 = chan_resume_cb,
1012         .suspend                = chan_suspend_cb,
1013         .get_sndtimeo           = chan_get_sndtimeo_cb,
1014         .alloc_skb              = chan_alloc_skb_cb,
1015
1016         .teardown               = l2cap_chan_no_teardown,
1017         .defer                  = l2cap_chan_no_defer,
1018         .set_shutdown           = l2cap_chan_no_set_shutdown,
1019 };
1020
1021 static inline __u8 bdaddr_type(__u8 type)
1022 {
1023         if (type == ADDR_LE_DEV_PUBLIC)
1024                 return BDADDR_LE_PUBLIC;
1025         else
1026                 return BDADDR_LE_RANDOM;
1027 }
1028
1029 static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type)
1030 {
1031         struct l2cap_chan *chan;
1032         int err;
1033
1034         chan = chan_create();
1035         if (!chan)
1036                 return -EINVAL;
1037
1038         chan->ops = &bt_6lowpan_chan_ops;
1039
1040         err = l2cap_chan_connect(chan, cpu_to_le16(L2CAP_PSM_IPSP), 0,
1041                                  addr, dst_type);
1042
1043         BT_DBG("chan %p err %d", chan, err);
1044         if (err < 0)
1045                 l2cap_chan_put(chan);
1046
1047         return err;
1048 }
1049
1050 static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type)
1051 {
1052         struct lowpan_peer *peer;
1053
1054         BT_DBG("conn %p dst type %d", conn, dst_type);
1055
1056         peer = lookup_peer(conn);
1057         if (!peer)
1058                 return -ENOENT;
1059
1060         BT_DBG("peer %p chan %p", peer, peer->chan);
1061
1062         l2cap_chan_close(peer->chan, ENOENT);
1063
1064         return 0;
1065 }
1066
1067 static struct l2cap_chan *bt_6lowpan_listen(void)
1068 {
1069         bdaddr_t *addr = BDADDR_ANY;
1070         struct l2cap_chan *chan;
1071         int err;
1072
1073         if (!enable_6lowpan)
1074                 return NULL;
1075
1076         chan = chan_create();
1077         if (!chan)
1078                 return NULL;
1079
1080         chan->ops = &bt_6lowpan_chan_ops;
1081         chan->state = BT_LISTEN;
1082         chan->src_type = BDADDR_LE_PUBLIC;
1083
1084         atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
1085
1086         BT_DBG("chan %p src type %d", chan, chan->src_type);
1087
1088         err = l2cap_add_psm(chan, addr, cpu_to_le16(L2CAP_PSM_IPSP));
1089         if (err) {
1090                 l2cap_chan_put(chan);
1091                 BT_ERR("psm cannot be added err %d", err);
1092                 return NULL;
1093         }
1094
1095         return chan;
1096 }
1097
1098 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type,
1099                           struct l2cap_conn **conn)
1100 {
1101         struct hci_conn *hcon;
1102         struct hci_dev *hdev;
1103         bdaddr_t *src = BDADDR_ANY;
1104         int n;
1105
1106         n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu",
1107                    &addr->b[5], &addr->b[4], &addr->b[3],
1108                    &addr->b[2], &addr->b[1], &addr->b[0],
1109                    addr_type);
1110
1111         if (n < 7)
1112                 return -EINVAL;
1113
1114         hdev = hci_get_route(addr, src);
1115         if (!hdev)
1116                 return -ENOENT;
1117
1118         hci_dev_lock(hdev);
1119         hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type);
1120         hci_dev_unlock(hdev);
1121
1122         if (!hcon)
1123                 return -ENOENT;
1124
1125         *conn = (struct l2cap_conn *)hcon->l2cap_data;
1126
1127         BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type);
1128
1129         return 0;
1130 }
1131
1132 static void disconnect_all_peers(void)
1133 {
1134         struct lowpan_dev *entry;
1135         struct lowpan_peer *peer, *tmp_peer, *new_peer;
1136         struct list_head peers;
1137
1138         INIT_LIST_HEAD(&peers);
1139
1140         /* We make a separate list of peers as the close_cb() will
1141          * modify the device peers list so it is better not to mess
1142          * with the same list at the same time.
1143          */
1144
1145         rcu_read_lock();
1146
1147         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1148                 list_for_each_entry_rcu(peer, &entry->peers, list) {
1149                         new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC);
1150                         if (!new_peer)
1151                                 break;
1152
1153                         new_peer->chan = peer->chan;
1154                         INIT_LIST_HEAD(&new_peer->list);
1155
1156                         list_add(&new_peer->list, &peers);
1157                 }
1158         }
1159
1160         rcu_read_unlock();
1161
1162         spin_lock(&devices_lock);
1163         list_for_each_entry_safe(peer, tmp_peer, &peers, list) {
1164                 l2cap_chan_close(peer->chan, ENOENT);
1165
1166                 list_del_rcu(&peer->list);
1167                 kfree_rcu(peer, rcu);
1168         }
1169         spin_unlock(&devices_lock);
1170 }
1171
1172 struct set_enable {
1173         struct work_struct work;
1174         bool flag;
1175 };
1176
1177 static void do_enable_set(struct work_struct *work)
1178 {
1179         struct set_enable *set_enable = container_of(work,
1180                                                      struct set_enable, work);
1181
1182         if (!set_enable->flag || enable_6lowpan != set_enable->flag)
1183                 /* Disconnect existing connections if 6lowpan is
1184                  * disabled
1185                  */
1186                 disconnect_all_peers();
1187
1188         enable_6lowpan = set_enable->flag;
1189
1190         if (listen_chan) {
1191                 l2cap_chan_close(listen_chan, 0);
1192                 l2cap_chan_put(listen_chan);
1193         }
1194
1195         listen_chan = bt_6lowpan_listen();
1196
1197         kfree(set_enable);
1198 }
1199
1200 static int lowpan_enable_set(void *data, u64 val)
1201 {
1202         struct set_enable *set_enable;
1203
1204         set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL);
1205         if (!set_enable)
1206                 return -ENOMEM;
1207
1208         set_enable->flag = !!val;
1209         INIT_WORK(&set_enable->work, do_enable_set);
1210
1211         schedule_work(&set_enable->work);
1212
1213         return 0;
1214 }
1215
1216 static int lowpan_enable_get(void *data, u64 *val)
1217 {
1218         *val = enable_6lowpan;
1219         return 0;
1220 }
1221
1222 DEFINE_SIMPLE_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get,
1223                         lowpan_enable_set, "%llu\n");
1224
1225 static ssize_t lowpan_control_write(struct file *fp,
1226                                     const char __user *user_buffer,
1227                                     size_t count,
1228                                     loff_t *position)
1229 {
1230         char buf[32];
1231         size_t buf_size = min(count, sizeof(buf) - 1);
1232         int ret;
1233         bdaddr_t addr;
1234         u8 addr_type;
1235         struct l2cap_conn *conn = NULL;
1236
1237         if (copy_from_user(buf, user_buffer, buf_size))
1238                 return -EFAULT;
1239
1240         buf[buf_size] = '\0';
1241
1242         if (memcmp(buf, "connect ", 8) == 0) {
1243                 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn);
1244                 if (ret == -EINVAL)
1245                         return ret;
1246
1247                 if (listen_chan) {
1248                         l2cap_chan_close(listen_chan, 0);
1249                         l2cap_chan_put(listen_chan);
1250                         listen_chan = NULL;
1251                 }
1252
1253                 if (conn) {
1254                         struct lowpan_peer *peer;
1255
1256                         if (!is_bt_6lowpan(conn->hcon))
1257                                 return -EINVAL;
1258
1259                         peer = lookup_peer(conn);
1260                         if (peer) {
1261                                 BT_DBG("6LoWPAN connection already exists");
1262                                 return -EALREADY;
1263                         }
1264
1265                         BT_DBG("conn %p dst %pMR type %d user %d", conn,
1266                                &conn->hcon->dst, conn->hcon->dst_type,
1267                                addr_type);
1268                 }
1269
1270                 ret = bt_6lowpan_connect(&addr, addr_type);
1271                 if (ret < 0)
1272                         return ret;
1273
1274                 return count;
1275         }
1276
1277         if (memcmp(buf, "disconnect ", 11) == 0) {
1278                 ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn);
1279                 if (ret < 0)
1280                         return ret;
1281
1282                 ret = bt_6lowpan_disconnect(conn, addr_type);
1283                 if (ret < 0)
1284                         return ret;
1285
1286                 return count;
1287         }
1288
1289         return count;
1290 }
1291
1292 static int lowpan_control_show(struct seq_file *f, void *ptr)
1293 {
1294         struct lowpan_dev *entry;
1295         struct lowpan_peer *peer;
1296
1297         spin_lock(&devices_lock);
1298
1299         list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1300                 list_for_each_entry(peer, &entry->peers, list)
1301                         seq_printf(f, "%pMR (type %u)\n",
1302                                    &peer->chan->dst, peer->chan->dst_type);
1303         }
1304
1305         spin_unlock(&devices_lock);
1306
1307         return 0;
1308 }
1309
1310 static int lowpan_control_open(struct inode *inode, struct file *file)
1311 {
1312         return single_open(file, lowpan_control_show, inode->i_private);
1313 }
1314
1315 static const struct file_operations lowpan_control_fops = {
1316         .open           = lowpan_control_open,
1317         .read           = seq_read,
1318         .write          = lowpan_control_write,
1319         .llseek         = seq_lseek,
1320         .release        = single_release,
1321 };
1322
1323 static void disconnect_devices(void)
1324 {
1325         struct lowpan_dev *entry, *tmp, *new_dev;
1326         struct list_head devices;
1327
1328         INIT_LIST_HEAD(&devices);
1329
1330         /* We make a separate list of devices because the unregister_netdev()
1331          * will call device_event() which will also want to modify the same
1332          * devices list.
1333          */
1334
1335         rcu_read_lock();
1336
1337         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1338                 new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC);
1339                 if (!new_dev)
1340                         break;
1341
1342                 new_dev->netdev = entry->netdev;
1343                 INIT_LIST_HEAD(&new_dev->list);
1344
1345                 list_add_rcu(&new_dev->list, &devices);
1346         }
1347
1348         rcu_read_unlock();
1349
1350         list_for_each_entry_safe(entry, tmp, &devices, list) {
1351                 ifdown(entry->netdev);
1352                 BT_DBG("Unregistering netdev %s %p",
1353                        entry->netdev->name, entry->netdev);
1354                 lowpan_unregister_netdev(entry->netdev);
1355                 kfree(entry);
1356         }
1357 }
1358
1359 static int device_event(struct notifier_block *unused,
1360                         unsigned long event, void *ptr)
1361 {
1362         struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
1363         struct lowpan_dev *entry;
1364
1365         if (netdev->type != ARPHRD_6LOWPAN)
1366                 return NOTIFY_DONE;
1367
1368         switch (event) {
1369         case NETDEV_UNREGISTER:
1370                 spin_lock(&devices_lock);
1371                 list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1372                         if (entry->netdev == netdev) {
1373                                 BT_DBG("Unregistered netdev %s %p",
1374                                        netdev->name, netdev);
1375                                 list_del(&entry->list);
1376                                 break;
1377                         }
1378                 }
1379                 spin_unlock(&devices_lock);
1380                 break;
1381         }
1382
1383         return NOTIFY_DONE;
1384 }
1385
1386 static struct notifier_block bt_6lowpan_dev_notifier = {
1387         .notifier_call = device_event,
1388 };
1389
1390 static int __init bt_6lowpan_init(void)
1391 {
1392         lowpan_enable_debugfs = debugfs_create_file("6lowpan_enable", 0644,
1393                                                     bt_debugfs, NULL,
1394                                                     &lowpan_enable_fops);
1395         lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644,
1396                                                      bt_debugfs, NULL,
1397                                                      &lowpan_control_fops);
1398
1399         return register_netdevice_notifier(&bt_6lowpan_dev_notifier);
1400 }
1401
1402 static void __exit bt_6lowpan_exit(void)
1403 {
1404         debugfs_remove(lowpan_enable_debugfs);
1405         debugfs_remove(lowpan_control_debugfs);
1406
1407         if (listen_chan) {
1408                 l2cap_chan_close(listen_chan, 0);
1409                 l2cap_chan_put(listen_chan);
1410         }
1411
1412         disconnect_devices();
1413
1414         unregister_netdevice_notifier(&bt_6lowpan_dev_notifier);
1415 }
1416
1417 module_init(bt_6lowpan_init);
1418 module_exit(bt_6lowpan_exit);
1419
1420 MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>");
1421 MODULE_DESCRIPTION("Bluetooth 6LoWPAN");
1422 MODULE_VERSION(VERSION);
1423 MODULE_LICENSE("GPL");