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_btle_dev {
  72         struct list_head list;
  73
  74         struct hci_dev *hdev;
  75         struct net_device *netdev;
  76         struct list_head peers;
  77         atomic_t peer_count; /* number of items in peers list */
  78
  79         struct work_struct delete_netdev;
  80         struct delayed_work notify_peers;
  81 };
  82
  83 static inline struct lowpan_btle_dev *
  84 lowpan_btle_dev(const struct net_device *netdev)
  85 {
  86         return (struct lowpan_btle_dev *)lowpan_dev(netdev)->priv;
  87 }
  88
  89 static inline void peer_add(struct lowpan_btle_dev *dev,
  90                             struct lowpan_peer *peer)
  91 {
  92         list_add_rcu(&peer->list, &dev->peers);
  93         atomic_inc(&dev->peer_count);
  94 }
  95
  96 static inline bool peer_del(struct lowpan_btle_dev *dev,
  97                             struct lowpan_peer *peer)
  98 {
  99         list_del_rcu(&peer->list);
 100         kfree_rcu(peer, rcu);
 101
 102         module_put(THIS_MODULE);
 103
 104         if (atomic_dec_and_test(&dev->peer_count)) {
 105                 BT_DBG("last peer");
 106                 return true;
 107         }
 108
 109         return false;
 110 }
 111
 112 static inline struct lowpan_peer *peer_lookup_ba(struct lowpan_btle_dev *dev,
 113                                                  bdaddr_t *ba, __u8 type)
 114 {
 115         struct lowpan_peer *peer;
 116
 117         BT_DBG("peers %d addr %pMR type %d", atomic_read(&dev->peer_count),
 118                ba, type);
 119
 120         rcu_read_lock();
 121
 122         list_for_each_entry_rcu(peer, &dev->peers, list) {
 123                 BT_DBG("dst addr %pMR dst type %d",
 124                        &peer->chan->dst, peer->chan->dst_type);
 125
 126                 if (bacmp(&peer->chan->dst, ba))
 127                         continue;
 128
 129                 if (type == peer->chan->dst_type) {
 130                         rcu_read_unlock();
 131                         return peer;
 132                 }
 133         }
 134
 135         rcu_read_unlock();
 136
 137         return NULL;
 138 }
 139
 140 static inline struct lowpan_peer *
 141 __peer_lookup_chan(struct lowpan_btle_dev *dev, struct l2cap_chan *chan)
 142 {
 143         struct lowpan_peer *peer;
 144
 145         list_for_each_entry_rcu(peer, &dev->peers, list) {
 146                 if (peer->chan == chan)
 147                         return peer;
 148         }
 149
 150         return NULL;
 151 }
 152
 153 static inline struct lowpan_peer *
 154 __peer_lookup_conn(struct lowpan_btle_dev *dev, struct l2cap_conn *conn)
 155 {
 156         struct lowpan_peer *peer;
 157
 158         list_for_each_entry_rcu(peer, &dev->peers, list) {
 159                 if (peer->chan->conn == conn)
 160                         return peer;
 161         }
 162
 163         return NULL;
 164 }
 165
 166 static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_btle_dev *dev,
 167                                                   struct in6_addr *daddr,
 168                                                   struct sk_buff *skb)
 169 {
 170         struct lowpan_peer *peer;
 171         struct in6_addr *nexthop;
 172         struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
 173         int count = atomic_read(&dev->peer_count);
 174
 175         BT_DBG("peers %d addr %pI6c rt %p", count, daddr, rt);
 176
 177         /* If we have multiple 6lowpan peers, then check where we should
 178          * send the packet. If only one peer exists, then we can send the
 179          * packet right away.
 180          */
 181         if (count == 1) {
 182                 rcu_read_lock();
 183                 peer = list_first_or_null_rcu(&dev->peers, struct lowpan_peer,
 184                                               list);
 185                 rcu_read_unlock();
 186                 return peer;
 187         }
 188
 189         if (!rt) {
 190                 nexthop = &lowpan_cb(skb)->gw;
 191
 192                 if (ipv6_addr_any(nexthop))
 193                         return NULL;
 194         } else {
 195                 nexthop = rt6_nexthop(rt, daddr);
 196
 197                 /* We need to remember the address because it is needed
 198                  * by bt_xmit() when sending the packet. In bt_xmit(), the
 199                  * destination routing info is not set.
 200                  */
 201                 memcpy(&lowpan_cb(skb)->gw, nexthop, sizeof(struct in6_addr));
 202         }
 203
 204         BT_DBG("gw %pI6c", nexthop);
 205
 206         rcu_read_lock();
 207
 208         list_for_each_entry_rcu(peer, &dev->peers, list) {
 209                 BT_DBG("dst addr %pMR dst type %d ip %pI6c",
 210                        &peer->chan->dst, peer->chan->dst_type,
 211                        &peer->peer_addr);
 212
 213                 if (!ipv6_addr_cmp(&peer->peer_addr, nexthop)) {
 214                         rcu_read_unlock();
 215                         return peer;
 216                 }
 217         }
 218
 219         rcu_read_unlock();
 220
 221         return NULL;
 222 }
 223
 224 static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn)
 225 {
 226         struct lowpan_btle_dev *entry;
 227         struct lowpan_peer *peer = NULL;
 228
 229         rcu_read_lock();
 230
 231         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 232                 peer = __peer_lookup_conn(entry, conn);
 233                 if (peer)
 234                         break;
 235         }
 236
 237         rcu_read_unlock();
 238
 239         return peer;
 240 }
 241
 242 static struct lowpan_btle_dev *lookup_dev(struct l2cap_conn *conn)
 243 {
 244         struct lowpan_btle_dev *entry;
 245         struct lowpan_btle_dev *dev = NULL;
 246
 247         rcu_read_lock();
 248
 249         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 250                 if (conn->hcon->hdev == entry->hdev) {
 251                         dev = entry;
 252                         break;
 253                 }
 254         }
 255
 256         rcu_read_unlock();
 257
 258         return dev;
 259 }
 260
 261 static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev)
 262 {
 263         struct sk_buff *skb_cp;
 264
 265         skb_cp = skb_copy(skb, GFP_ATOMIC);
 266         if (!skb_cp)
 267                 return NET_RX_DROP;
 268
 269         return netif_rx_ni(skb_cp);
 270 }
 271
 272 static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev,
 273                            struct l2cap_chan *chan)
 274 {
 275         const u8 *saddr, *daddr;
 276         struct lowpan_btle_dev *dev;
 277         struct lowpan_peer *peer;
 278
 279         dev = lowpan_btle_dev(netdev);
 280
 281         rcu_read_lock();
 282         peer = __peer_lookup_chan(dev, chan);
 283         rcu_read_unlock();
 284         if (!peer)
 285                 return -EINVAL;
 286
 287         saddr = peer->eui64_addr;
 288         daddr = dev->netdev->dev_addr;
 289
 290         return lowpan_header_decompress(skb, netdev, daddr, saddr);
 291 }
 292
 293 static int recv_pkt(struct sk_buff *skb, struct net_device *dev,
 294                     struct l2cap_chan *chan)
 295 {
 296         struct sk_buff *local_skb;
 297         int ret;
 298
 299         if (!netif_running(dev))
 300                 goto drop;
 301
 302         if (dev->type != ARPHRD_6LOWPAN || !skb->len)
 303                 goto drop;
 304
 305         skb_reset_network_header(skb);
 306
 307         skb = skb_share_check(skb, GFP_ATOMIC);
 308         if (!skb)
 309                 goto drop;
 310
 311         /* check that it's our buffer */
 312         if (lowpan_is_ipv6(*skb_network_header(skb))) {
 313                 /* Pull off the 1-byte of 6lowpan header. */
 314                 skb_pull(skb, 1);
 315
 316                 /* Copy the packet so that the IPv6 header is
 317                  * properly aligned.
 318                  */
 319                 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
 320                                             skb_tailroom(skb), GFP_ATOMIC);
 321                 if (!local_skb)
 322                         goto drop;
 323
 324                 local_skb->protocol = htons(ETH_P_IPV6);
 325                 local_skb->pkt_type = PACKET_HOST;
 326                 local_skb->dev = dev;
 327
 328                 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
 329
 330                 if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) {
 331                         kfree_skb(local_skb);
 332                         goto drop;
 333                 }
 334
 335                 dev->stats.rx_bytes += skb->len;
 336                 dev->stats.rx_packets++;
 337
 338                 consume_skb(local_skb);
 339                 consume_skb(skb);
 340         } else if (lowpan_is_iphc(*skb_network_header(skb))) {
 341                 local_skb = skb_clone(skb, GFP_ATOMIC);
 342                 if (!local_skb)
 343                         goto drop;
 344
 345                 local_skb->dev = dev;
 346
 347                 ret = iphc_decompress(local_skb, dev, chan);
 348                 if (ret < 0) {
 349                         kfree_skb(local_skb);
 350                         goto drop;
 351                 }
 352
 353                 local_skb->protocol = htons(ETH_P_IPV6);
 354                 local_skb->pkt_type = PACKET_HOST;
 355
 356                 if (give_skb_to_upper(local_skb, dev)
 357                                 != NET_RX_SUCCESS) {
 358                         kfree_skb(local_skb);
 359                         goto drop;
 360                 }
 361
 362                 dev->stats.rx_bytes += skb->len;
 363                 dev->stats.rx_packets++;
 364
 365                 consume_skb(local_skb);
 366                 consume_skb(skb);
 367         } else {
 368                 goto drop;
 369         }
 370
 371         return NET_RX_SUCCESS;
 372
 373 drop:
 374         dev->stats.rx_dropped++;
 375         return NET_RX_DROP;
 376 }
 377
 378 /* Packet from BT LE device */
 379 static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
 380 {
 381         struct lowpan_btle_dev *dev;
 382         struct lowpan_peer *peer;
 383         int err;
 384
 385         peer = lookup_peer(chan->conn);
 386         if (!peer)
 387                 return -ENOENT;
 388
 389         dev = lookup_dev(chan->conn);
 390         if (!dev || !dev->netdev)
 391                 return -ENOENT;
 392
 393         err = recv_pkt(skb, dev->netdev, chan);
 394         if (err) {
 395                 BT_DBG("recv pkt %d", err);
 396                 err = -EAGAIN;
 397         }
 398
 399         return err;
 400 }
 401
 402 static u8 get_addr_type_from_eui64(u8 byte)
 403 {
 404         /* Is universal(0) or local(1) bit */
 405         return ((byte & 0x02) ? BDADDR_LE_RANDOM : BDADDR_LE_PUBLIC);
 406 }
 407
 408 static void copy_to_bdaddr(struct in6_addr *ip6_daddr, bdaddr_t *addr)
 409 {
 410         u8 *eui64 = ip6_daddr->s6_addr + 8;
 411
 412         addr->b[0] = eui64[7];
 413         addr->b[1] = eui64[6];
 414         addr->b[2] = eui64[5];
 415         addr->b[3] = eui64[2];
 416         addr->b[4] = eui64[1];
 417         addr->b[5] = eui64[0];
 418 }
 419
 420 static void convert_dest_bdaddr(struct in6_addr *ip6_daddr,
 421                                 bdaddr_t *addr, u8 *addr_type)
 422 {
 423         copy_to_bdaddr(ip6_daddr, addr);
 424
 425         /* We need to toggle the U/L bit that we got from IPv6 address
 426          * so that we get the proper address and type of the BD address.
 427          */
 428         addr->b[5] ^= 0x02;
 429
 430         *addr_type = get_addr_type_from_eui64(addr->b[5]);
 431 }
 432
 433 static int setup_header(struct sk_buff *skb, struct net_device *netdev,
 434                         bdaddr_t *peer_addr, u8 *peer_addr_type)
 435 {
 436         struct in6_addr ipv6_daddr;
 437         struct ipv6hdr *hdr;
 438         struct lowpan_btle_dev *dev;
 439         struct lowpan_peer *peer;
 440         bdaddr_t addr, *any = BDADDR_ANY;
 441         u8 *daddr = any->b;
 442         int err, status = 0;
 443
 444         hdr = ipv6_hdr(skb);
 445
 446         dev = lowpan_btle_dev(netdev);
 447
 448         memcpy(&ipv6_daddr, &hdr->daddr, sizeof(ipv6_daddr));
 449
 450         if (ipv6_addr_is_multicast(&ipv6_daddr)) {
 451                 lowpan_cb(skb)->chan = NULL;
 452         } else {
 453                 u8 addr_type;
 454
 455                 /* Get destination BT device from skb.
 456                  * If there is no such peer then discard the packet.
 457                  */
 458                 convert_dest_bdaddr(&ipv6_daddr, &addr, &addr_type);
 459
 460                 BT_DBG("dest addr %pMR type %d IP %pI6c", &addr,
 461                        addr_type, &ipv6_daddr);
 462
 463                 peer = peer_lookup_ba(dev, &addr, addr_type);
 464                 if (!peer) {
 465                         /* The packet might be sent to 6lowpan interface
 466                          * because of routing (either via default route
 467                          * or user set route) so get peer according to
 468                          * the destination address.
 469                          */
 470                         peer = peer_lookup_dst(dev, &ipv6_daddr, skb);
 471                         if (!peer) {
 472                                 BT_DBG("no such peer %pMR found", &addr);
 473                                 return -ENOENT;
 474                         }
 475                 }
 476
 477                 daddr = peer->eui64_addr;
 478                 *peer_addr = addr;
 479                 *peer_addr_type = addr_type;
 480                 lowpan_cb(skb)->chan = peer->chan;
 481
 482                 status = 1;
 483         }
 484
 485         lowpan_header_compress(skb, netdev, daddr, dev->netdev->dev_addr);
 486
 487         err = dev_hard_header(skb, netdev, ETH_P_IPV6, NULL, NULL, 0);
 488         if (err < 0)
 489                 return err;
 490
 491         return status;
 492 }
 493
 494 static int header_create(struct sk_buff *skb, struct net_device *netdev,
 495                          unsigned short type, const void *_daddr,
 496                          const void *_saddr, unsigned int len)
 497 {
 498         if (type != ETH_P_IPV6)
 499                 return -EINVAL;
 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_btle_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_btle_dev *dev;
 554
 555                 if (entry->netdev != netdev)
 556                         continue;
 557
 558                 dev = lowpan_btle_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 int bt_dev_init(struct net_device *dev)
 631 {
 632         netdev_lockdep_set_classes(dev);
 633
 634         return 0;
 635 }
 636
 637 static const struct net_device_ops netdev_ops = {
 638         .ndo_init               = bt_dev_init,
 639         .ndo_start_xmit         = bt_xmit,
 640 };
 641
 642 static struct header_ops header_ops = {
 643         .create = header_create,
 644 };
 645
 646 static void netdev_setup(struct net_device *dev)
 647 {
 648         dev->hard_header_len    = 0;
 649         dev->needed_tailroom    = 0;
 650         dev->flags              = IFF_RUNNING | IFF_POINTOPOINT |
 651                                   IFF_MULTICAST;
 652         dev->watchdog_timeo     = 0;
 653
 654         dev->netdev_ops         = &netdev_ops;
 655         dev->header_ops         = &header_ops;
 656         dev->destructor         = free_netdev;
 657 }
 658
 659 static struct device_type bt_type = {
 660         .name   = "bluetooth",
 661 };
 662
 663 static void set_addr(u8 *eui, u8 *addr, u8 addr_type)
 664 {
 665         /* addr is the BT address in little-endian format */
 666         eui[0] = addr[5];
 667         eui[1] = addr[4];
 668         eui[2] = addr[3];
 669         eui[3] = 0xFF;
 670         eui[4] = 0xFE;
 671         eui[5] = addr[2];
 672         eui[6] = addr[1];
 673         eui[7] = addr[0];
 674
 675         /* Universal/local bit set, BT 6lowpan draft ch. 3.2.1 */
 676         if (addr_type == BDADDR_LE_PUBLIC)
 677                 eui[0] &= ~0x02;
 678         else
 679                 eui[0] |= 0x02;
 680
 681         BT_DBG("type %d addr %*phC", addr_type, 8, eui);
 682 }
 683
 684 static void set_dev_addr(struct net_device *netdev, bdaddr_t *addr,
 685                          u8 addr_type)
 686 {
 687         netdev->addr_assign_type = NET_ADDR_PERM;
 688         set_addr(netdev->dev_addr, addr->b, addr_type);
 689 }
 690
 691 static void ifup(struct net_device *netdev)
 692 {
 693         int err;
 694
 695         rtnl_lock();
 696         err = dev_open(netdev);
 697         if (err < 0)
 698                 BT_INFO("iface %s cannot be opened (%d)", netdev->name, err);
 699         rtnl_unlock();
 700 }
 701
 702 static void ifdown(struct net_device *netdev)
 703 {
 704         int err;
 705
 706         rtnl_lock();
 707         err = dev_close(netdev);
 708         if (err < 0)
 709                 BT_INFO("iface %s cannot be closed (%d)", netdev->name, err);
 710         rtnl_unlock();
 711 }
 712
 713 static void do_notify_peers(struct work_struct *work)
 714 {
 715         struct lowpan_btle_dev *dev = container_of(work, struct lowpan_btle_dev,
 716                                                    notify_peers.work);
 717
 718         netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */
 719 }
 720
 721 static bool is_bt_6lowpan(struct hci_conn *hcon)
 722 {
 723         if (hcon->type != LE_LINK)
 724                 return false;
 725
 726         if (!enable_6lowpan)
 727                 return false;
 728
 729         return true;
 730 }
 731
 732 static struct l2cap_chan *chan_create(void)
 733 {
 734         struct l2cap_chan *chan;
 735
 736         chan = l2cap_chan_create();
 737         if (!chan)
 738                 return NULL;
 739
 740         l2cap_chan_set_defaults(chan);
 741
 742         chan->chan_type = L2CAP_CHAN_CONN_ORIENTED;
 743         chan->mode = L2CAP_MODE_LE_FLOWCTL;
 744         chan->imtu = 1280;
 745
 746         return chan;
 747 }
 748
 749 static void set_ip_addr_bits(u8 addr_type, u8 *addr)
 750 {
 751         if (addr_type == BDADDR_LE_PUBLIC)
 752                 *addr |= 0x02;
 753         else
 754                 *addr &= ~0x02;
 755 }
 756
 757 static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan,
 758                                         struct lowpan_btle_dev *dev)
 759 {
 760         struct lowpan_peer *peer;
 761
 762         peer = kzalloc(sizeof(*peer), GFP_ATOMIC);
 763         if (!peer)
 764                 return NULL;
 765
 766         peer->chan = chan;
 767         memset(&peer->peer_addr, 0, sizeof(struct in6_addr));
 768
 769         /* RFC 2464 ch. 5 */
 770         peer->peer_addr.s6_addr[0] = 0xFE;
 771         peer->peer_addr.s6_addr[1] = 0x80;
 772         set_addr((u8 *)&peer->peer_addr.s6_addr + 8, chan->dst.b,
 773                  chan->dst_type);
 774
 775         memcpy(&peer->eui64_addr, (u8 *)&peer->peer_addr.s6_addr + 8,
 776                EUI64_ADDR_LEN);
 777
 778         /* IPv6 address needs to have the U/L bit set properly so toggle
 779          * it back here.
 780          */
 781         set_ip_addr_bits(chan->dst_type, (u8 *)&peer->peer_addr.s6_addr + 8);
 782
 783         spin_lock(&devices_lock);
 784         INIT_LIST_HEAD(&peer->list);
 785         peer_add(dev, peer);
 786         spin_unlock(&devices_lock);
 787
 788         /* Notifying peers about us needs to be done without locks held */
 789         INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers);
 790         schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100));
 791
 792         return peer->chan;
 793 }
 794
 795 static int setup_netdev(struct l2cap_chan *chan, struct lowpan_btle_dev **dev)
 796 {
 797         struct net_device *netdev;
 798         int err = 0;
 799
 800         netdev = alloc_netdev(LOWPAN_PRIV_SIZE(sizeof(struct lowpan_btle_dev)),
 801                               IFACE_NAME_TEMPLATE, NET_NAME_UNKNOWN,
 802                               netdev_setup);
 803         if (!netdev)
 804                 return -ENOMEM;
 805
 806         set_dev_addr(netdev, &chan->src, chan->src_type);
 807
 808         netdev->netdev_ops = &netdev_ops;
 809         SET_NETDEV_DEV(netdev, &chan->conn->hcon->hdev->dev);
 810         SET_NETDEV_DEVTYPE(netdev, &bt_type);
 811
 812         *dev = lowpan_btle_dev(netdev);
 813         (*dev)->netdev = netdev;
 814         (*dev)->hdev = chan->conn->hcon->hdev;
 815         INIT_LIST_HEAD(&(*dev)->peers);
 816
 817         spin_lock(&devices_lock);
 818         INIT_LIST_HEAD(&(*dev)->list);
 819         list_add_rcu(&(*dev)->list, &bt_6lowpan_devices);
 820         spin_unlock(&devices_lock);
 821
 822         err = lowpan_register_netdev(netdev, LOWPAN_LLTYPE_BTLE);
 823         if (err < 0) {
 824                 BT_INFO("register_netdev failed %d", err);
 825                 spin_lock(&devices_lock);
 826                 list_del_rcu(&(*dev)->list);
 827                 spin_unlock(&devices_lock);
 828                 free_netdev(netdev);
 829                 goto out;
 830         }
 831
 832         BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d",
 833                netdev->ifindex, &chan->dst, chan->dst_type,
 834                &chan->src, chan->src_type);
 835         set_bit(__LINK_STATE_PRESENT, &netdev->state);
 836
 837         return 0;
 838
 839 out:
 840         return err;
 841 }
 842
 843 static inline void chan_ready_cb(struct l2cap_chan *chan)
 844 {
 845         struct lowpan_btle_dev *dev;
 846
 847         dev = lookup_dev(chan->conn);
 848
 849         BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev);
 850
 851         if (!dev) {
 852                 if (setup_netdev(chan, &dev) < 0) {
 853                         l2cap_chan_del(chan, -ENOENT);
 854                         return;
 855                 }
 856         }
 857
 858         if (!try_module_get(THIS_MODULE))
 859                 return;
 860
 861         add_peer_chan(chan, dev);
 862         ifup(dev->netdev);
 863 }
 864
 865 static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan)
 866 {
 867         struct l2cap_chan *chan;
 868
 869         chan = chan_create();
 870         if (!chan)
 871                 return NULL;
 872
 873         chan->ops = pchan->ops;
 874
 875         BT_DBG("chan %p pchan %p", chan, pchan);
 876
 877         return chan;
 878 }
 879
 880 static void delete_netdev(struct work_struct *work)
 881 {
 882         struct lowpan_btle_dev *entry = container_of(work,
 883                                                      struct lowpan_btle_dev,
 884                                                      delete_netdev);
 885
 886         lowpan_unregister_netdev(entry->netdev);
 887
 888         /* The entry pointer is deleted by the netdev destructor. */
 889 }
 890
 891 static void chan_close_cb(struct l2cap_chan *chan)
 892 {
 893         struct lowpan_btle_dev *entry;
 894         struct lowpan_btle_dev *dev = NULL;
 895         struct lowpan_peer *peer;
 896         int err = -ENOENT;
 897         bool last = false, remove = true;
 898
 899         BT_DBG("chan %p conn %p", chan, chan->conn);
 900
 901         if (chan->conn && chan->conn->hcon) {
 902                 if (!is_bt_6lowpan(chan->conn->hcon))
 903                         return;
 904
 905                 /* If conn is set, then the netdev is also there and we should
 906                  * not remove it.
 907                  */
 908                 remove = false;
 909         }
 910
 911         spin_lock(&devices_lock);
 912
 913         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 914                 dev = lowpan_btle_dev(entry->netdev);
 915                 peer = __peer_lookup_chan(dev, chan);
 916                 if (peer) {
 917                         last = peer_del(dev, peer);
 918                         err = 0;
 919
 920                         BT_DBG("dev %p removing %speer %p", dev,
 921                                last ? "last " : "1 ", peer);
 922                         BT_DBG("chan %p orig refcnt %d", chan,
 923                                atomic_read(&chan->kref.refcount));
 924
 925                         l2cap_chan_put(chan);
 926                         break;
 927                 }
 928         }
 929
 930         if (!err && last && dev && !atomic_read(&dev->peer_count)) {
 931                 spin_unlock(&devices_lock);
 932
 933                 cancel_delayed_work_sync(&dev->notify_peers);
 934
 935                 ifdown(dev->netdev);
 936
 937                 if (remove) {
 938                         INIT_WORK(&entry->delete_netdev, delete_netdev);
 939                         schedule_work(&entry->delete_netdev);
 940                 }
 941         } else {
 942                 spin_unlock(&devices_lock);
 943         }
 944
 945         return;
 946 }
 947
 948 static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err)
 949 {
 950         BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn,
 951                state_to_string(state), err);
 952 }
 953
 954 static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan,
 955                                          unsigned long hdr_len,
 956                                          unsigned long len, int nb)
 957 {
 958         /* Note that we must allocate using GFP_ATOMIC here as
 959          * this function is called originally from netdev hard xmit
 960          * function in atomic context.
 961          */
 962         return bt_skb_alloc(hdr_len + len, GFP_ATOMIC);
 963 }
 964
 965 static void chan_suspend_cb(struct l2cap_chan *chan)
 966 {
 967         struct sk_buff *skb = chan->data;
 968
 969         BT_DBG("chan %p conn %p skb %p", chan, chan->conn, skb);
 970
 971         if (!skb)
 972                 return;
 973
 974         lowpan_cb(skb)->status = -EAGAIN;
 975 }
 976
 977 static void chan_resume_cb(struct l2cap_chan *chan)
 978 {
 979         struct sk_buff *skb = chan->data;
 980
 981         BT_DBG("chan %p conn %p skb %p", chan, chan->conn, skb);
 982
 983         if (!skb)
 984                 return;
 985
 986         lowpan_cb(skb)->status = 0;
 987 }
 988
 989 static long chan_get_sndtimeo_cb(struct l2cap_chan *chan)
 990 {
 991         return L2CAP_CONN_TIMEOUT;
 992 }
 993
 994 static const struct l2cap_ops bt_6lowpan_chan_ops = {
 995         .name                   = "L2CAP 6LoWPAN channel",
 996         .new_connection         = chan_new_conn_cb,
 997         .recv                   = chan_recv_cb,
 998         .close                  = chan_close_cb,
 999         .state_change           = chan_state_change_cb,
1000         .ready                  = chan_ready_cb,
1001         .resume                 = chan_resume_cb,
1002         .suspend                = chan_suspend_cb,
1003         .get_sndtimeo           = chan_get_sndtimeo_cb,
1004         .alloc_skb              = chan_alloc_skb_cb,
1005
1006         .teardown               = l2cap_chan_no_teardown,
1007         .defer                  = l2cap_chan_no_defer,
1008         .set_shutdown           = l2cap_chan_no_set_shutdown,
1009 };
1010
1011 static inline __u8 bdaddr_type(__u8 type)
1012 {
1013         if (type == ADDR_LE_DEV_PUBLIC)
1014                 return BDADDR_LE_PUBLIC;
1015         else
1016                 return BDADDR_LE_RANDOM;
1017 }
1018
1019 static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type)
1020 {
1021         struct l2cap_chan *chan;
1022         int err;
1023
1024         chan = chan_create();
1025         if (!chan)
1026                 return -EINVAL;
1027
1028         chan->ops = &bt_6lowpan_chan_ops;
1029
1030         err = l2cap_chan_connect(chan, cpu_to_le16(L2CAP_PSM_IPSP), 0,
1031                                  addr, dst_type);
1032
1033         BT_DBG("chan %p err %d", chan, err);
1034         if (err < 0)
1035                 l2cap_chan_put(chan);
1036
1037         return err;
1038 }
1039
1040 static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type)
1041 {
1042         struct lowpan_peer *peer;
1043
1044         BT_DBG("conn %p dst type %d", conn, dst_type);
1045
1046         peer = lookup_peer(conn);
1047         if (!peer)
1048                 return -ENOENT;
1049
1050         BT_DBG("peer %p chan %p", peer, peer->chan);
1051
1052         l2cap_chan_close(peer->chan, ENOENT);
1053
1054         return 0;
1055 }
1056
1057 static struct l2cap_chan *bt_6lowpan_listen(void)
1058 {
1059         bdaddr_t *addr = BDADDR_ANY;
1060         struct l2cap_chan *chan;
1061         int err;
1062
1063         if (!enable_6lowpan)
1064                 return NULL;
1065
1066         chan = chan_create();
1067         if (!chan)
1068                 return NULL;
1069
1070         chan->ops = &bt_6lowpan_chan_ops;
1071         chan->state = BT_LISTEN;
1072         chan->src_type = BDADDR_LE_PUBLIC;
1073
1074         atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
1075
1076         BT_DBG("chan %p src type %d", chan, chan->src_type);
1077
1078         err = l2cap_add_psm(chan, addr, cpu_to_le16(L2CAP_PSM_IPSP));
1079         if (err) {
1080                 l2cap_chan_put(chan);
1081                 BT_ERR("psm cannot be added err %d", err);
1082                 return NULL;
1083         }
1084
1085         return chan;
1086 }
1087
1088 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type,
1089                           struct l2cap_conn **conn)
1090 {
1091         struct hci_conn *hcon;
1092         struct hci_dev *hdev;
1093         bdaddr_t *src = BDADDR_ANY;
1094         int n;
1095
1096         n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu",
1097                    &addr->b[5], &addr->b[4], &addr->b[3],
1098                    &addr->b[2], &addr->b[1], &addr->b[0],
1099                    addr_type);
1100
1101         if (n < 7)
1102                 return -EINVAL;
1103
1104         hdev = hci_get_route(addr, src);
1105         if (!hdev)
1106                 return -ENOENT;
1107
1108         hci_dev_lock(hdev);
1109         hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type);
1110         hci_dev_unlock(hdev);
1111
1112         if (!hcon)
1113                 return -ENOENT;
1114
1115         *conn = (struct l2cap_conn *)hcon->l2cap_data;
1116
1117         BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type);
1118
1119         return 0;
1120 }
1121
1122 static void disconnect_all_peers(void)
1123 {
1124         struct lowpan_btle_dev *entry;
1125         struct lowpan_peer *peer, *tmp_peer, *new_peer;
1126         struct list_head peers;
1127
1128         INIT_LIST_HEAD(&peers);
1129
1130         /* We make a separate list of peers as the close_cb() will
1131          * modify the device peers list so it is better not to mess
1132          * with the same list at the same time.
1133          */
1134
1135         rcu_read_lock();
1136
1137         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1138                 list_for_each_entry_rcu(peer, &entry->peers, list) {
1139                         new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC);
1140                         if (!new_peer)
1141                                 break;
1142
1143                         new_peer->chan = peer->chan;
1144                         INIT_LIST_HEAD(&new_peer->list);
1145
1146                         list_add(&new_peer->list, &peers);
1147                 }
1148         }
1149
1150         rcu_read_unlock();
1151
1152         spin_lock(&devices_lock);
1153         list_for_each_entry_safe(peer, tmp_peer, &peers, list) {
1154                 l2cap_chan_close(peer->chan, ENOENT);
1155
1156                 list_del_rcu(&peer->list);
1157                 kfree_rcu(peer, rcu);
1158         }
1159         spin_unlock(&devices_lock);
1160 }
1161
1162 struct set_enable {
1163         struct work_struct work;
1164         bool flag;
1165 };
1166
1167 static void do_enable_set(struct work_struct *work)
1168 {
1169         struct set_enable *set_enable = container_of(work,
1170                                                      struct set_enable, work);
1171
1172         if (!set_enable->flag || enable_6lowpan != set_enable->flag)
1173                 /* Disconnect existing connections if 6lowpan is
1174                  * disabled
1175                  */
1176                 disconnect_all_peers();
1177
1178         enable_6lowpan = set_enable->flag;
1179
1180         if (listen_chan) {
1181                 l2cap_chan_close(listen_chan, 0);
1182                 l2cap_chan_put(listen_chan);
1183         }
1184
1185         listen_chan = bt_6lowpan_listen();
1186
1187         kfree(set_enable);
1188 }
1189
1190 static int lowpan_enable_set(void *data, u64 val)
1191 {
1192         struct set_enable *set_enable;
1193
1194         set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL);
1195         if (!set_enable)
1196                 return -ENOMEM;
1197
1198         set_enable->flag = !!val;
1199         INIT_WORK(&set_enable->work, do_enable_set);
1200
1201         schedule_work(&set_enable->work);
1202
1203         return 0;
1204 }
1205
1206 static int lowpan_enable_get(void *data, u64 *val)
1207 {
1208         *val = enable_6lowpan;
1209         return 0;
1210 }
1211
1212 DEFINE_SIMPLE_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get,
1213                         lowpan_enable_set, "%llu\n");
1214
1215 static ssize_t lowpan_control_write(struct file *fp,
1216                                     const char __user *user_buffer,
1217                                     size_t count,
1218                                     loff_t *position)
1219 {
1220         char buf[32];
1221         size_t buf_size = min(count, sizeof(buf) - 1);
1222         int ret;
1223         bdaddr_t addr;
1224         u8 addr_type;
1225         struct l2cap_conn *conn = NULL;
1226
1227         if (copy_from_user(buf, user_buffer, buf_size))
1228                 return -EFAULT;
1229
1230         buf[buf_size] = '\0';
1231
1232         if (memcmp(buf, "connect ", 8) == 0) {
1233                 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn);
1234                 if (ret == -EINVAL)
1235                         return ret;
1236
1237                 if (listen_chan) {
1238                         l2cap_chan_close(listen_chan, 0);
1239                         l2cap_chan_put(listen_chan);
1240                         listen_chan = NULL;
1241                 }
1242
1243                 if (conn) {
1244                         struct lowpan_peer *peer;
1245
1246                         if (!is_bt_6lowpan(conn->hcon))
1247                                 return -EINVAL;
1248
1249                         peer = lookup_peer(conn);
1250                         if (peer) {
1251                                 BT_DBG("6LoWPAN connection already exists");
1252                                 return -EALREADY;
1253                         }
1254
1255                         BT_DBG("conn %p dst %pMR type %d user %d", conn,
1256                                &conn->hcon->dst, conn->hcon->dst_type,
1257                                addr_type);
1258                 }
1259
1260                 ret = bt_6lowpan_connect(&addr, addr_type);
1261                 if (ret < 0)
1262                         return ret;
1263
1264                 return count;
1265         }
1266
1267         if (memcmp(buf, "disconnect ", 11) == 0) {
1268                 ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn);
1269                 if (ret < 0)
1270                         return ret;
1271
1272                 ret = bt_6lowpan_disconnect(conn, addr_type);
1273                 if (ret < 0)
1274                         return ret;
1275
1276                 return count;
1277         }
1278
1279         return count;
1280 }
1281
1282 static int lowpan_control_show(struct seq_file *f, void *ptr)
1283 {
1284         struct lowpan_btle_dev *entry;
1285         struct lowpan_peer *peer;
1286
1287         spin_lock(&devices_lock);
1288
1289         list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1290                 list_for_each_entry(peer, &entry->peers, list)
1291                         seq_printf(f, "%pMR (type %u)\n",
1292                                    &peer->chan->dst, peer->chan->dst_type);
1293         }
1294
1295         spin_unlock(&devices_lock);
1296
1297         return 0;
1298 }
1299
1300 static int lowpan_control_open(struct inode *inode, struct file *file)
1301 {
1302         return single_open(file, lowpan_control_show, inode->i_private);
1303 }
1304
1305 static const struct file_operations lowpan_control_fops = {
1306         .open           = lowpan_control_open,
1307         .read           = seq_read,
1308         .write          = lowpan_control_write,
1309         .llseek         = seq_lseek,
1310         .release        = single_release,
1311 };
1312
1313 static void disconnect_devices(void)
1314 {
1315         struct lowpan_btle_dev *entry, *tmp, *new_dev;
1316         struct list_head devices;
1317
1318         INIT_LIST_HEAD(&devices);
1319
1320         /* We make a separate list of devices because the unregister_netdev()
1321          * will call device_event() which will also want to modify the same
1322          * devices list.
1323          */
1324
1325         rcu_read_lock();
1326
1327         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1328                 new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC);
1329                 if (!new_dev)
1330                         break;
1331
1332                 new_dev->netdev = entry->netdev;
1333                 INIT_LIST_HEAD(&new_dev->list);
1334
1335                 list_add_rcu(&new_dev->list, &devices);
1336         }
1337
1338         rcu_read_unlock();
1339
1340         list_for_each_entry_safe(entry, tmp, &devices, list) {
1341                 ifdown(entry->netdev);
1342                 BT_DBG("Unregistering netdev %s %p",
1343                        entry->netdev->name, entry->netdev);
1344                 lowpan_unregister_netdev(entry->netdev);
1345                 kfree(entry);
1346         }
1347 }
1348
1349 static int device_event(struct notifier_block *unused,
1350                         unsigned long event, void *ptr)
1351 {
1352         struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
1353         struct lowpan_btle_dev *entry;
1354
1355         if (netdev->type != ARPHRD_6LOWPAN)
1356                 return NOTIFY_DONE;
1357
1358         switch (event) {
1359         case NETDEV_UNREGISTER:
1360                 spin_lock(&devices_lock);
1361                 list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1362                         if (entry->netdev == netdev) {
1363                                 BT_DBG("Unregistered netdev %s %p",
1364                                        netdev->name, netdev);
1365                                 list_del(&entry->list);
1366                                 break;
1367                         }
1368                 }
1369                 spin_unlock(&devices_lock);
1370                 break;
1371         }
1372
1373         return NOTIFY_DONE;
1374 }
1375
1376 static struct notifier_block bt_6lowpan_dev_notifier = {
1377         .notifier_call = device_event,
1378 };
1379
1380 static int __init bt_6lowpan_init(void)
1381 {
1382         lowpan_enable_debugfs = debugfs_create_file("6lowpan_enable", 0644,
1383                                                     bt_debugfs, NULL,
1384                                                     &lowpan_enable_fops);
1385         lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644,
1386                                                      bt_debugfs, NULL,
1387                                                      &lowpan_control_fops);
1388
1389         return register_netdevice_notifier(&bt_6lowpan_dev_notifier);
1390 }
1391
1392 static void __exit bt_6lowpan_exit(void)
1393 {
1394         debugfs_remove(lowpan_enable_debugfs);
1395         debugfs_remove(lowpan_control_debugfs);
1396
1397         if (listen_chan) {
1398                 l2cap_chan_close(listen_chan, 0);
1399                 l2cap_chan_put(listen_chan);
1400         }
1401
1402         disconnect_devices();
1403
1404         unregister_netdevice_notifier(&bt_6lowpan_dev_notifier);
1405 }
1406
1407 module_init(bt_6lowpan_init);
1408 module_exit(bt_6lowpan_exit);
1409
1410 MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>");
1411 MODULE_DESCRIPTION("Bluetooth 6LoWPAN");
1412 MODULE_VERSION(VERSION);
1413 MODULE_LICENSE("GPL");