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/af_ieee802154.h> /* to get the address type */
  25
  26 #include <net/bluetooth/bluetooth.h>
  27 #include <net/bluetooth/hci_core.h>
  28 #include <net/bluetooth/l2cap.h>
  29
  30 #include <net/6lowpan.h> /* for the compression support */
  31
  32 #define VERSION "0.1"
  33
  34 static struct dentry *lowpan_psm_debugfs;
  35 static struct dentry *lowpan_control_debugfs;
  36
  37 #define IFACE_NAME_TEMPLATE "bt%d"
  38 #define EUI64_ADDR_LEN 8
  39
  40 struct skb_cb {
  41         struct in6_addr addr;
  42         struct l2cap_chan *chan;
  43         int status;
  44 };
  45 #define lowpan_cb(skb) ((struct skb_cb *)((skb)->cb))
  46
  47 /* The devices list contains those devices that we are acting
  48  * as a proxy. The BT 6LoWPAN device is a virtual device that
  49  * connects to the Bluetooth LE device. The real connection to
  50  * BT device is done via l2cap layer. There exists one
  51  * virtual device / one BT 6LoWPAN network (=hciX device).
  52  * The list contains struct lowpan_dev elements.
  53  */
  54 static LIST_HEAD(bt_6lowpan_devices);
  55 static DEFINE_RWLOCK(devices_lock);
  56
  57 /* If psm is set to 0 (default value), then 6lowpan is disabled.
  58  * Other values are used to indicate a Protocol Service Multiplexer
  59  * value for 6lowpan.
  60  */
  61 static u16 psm_6lowpan;
  62
  63 /* We are listening incoming connections via this channel
  64  */
  65 static struct l2cap_chan *listen_chan;
  66
  67 struct lowpan_peer {
  68         struct list_head list;
  69         struct l2cap_chan *chan;
  70
  71         /* peer addresses in various formats */
  72         unsigned char eui64_addr[EUI64_ADDR_LEN];
  73         struct in6_addr peer_addr;
  74 };
  75
  76 struct lowpan_dev {
  77         struct list_head list;
  78
  79         struct hci_dev *hdev;
  80         struct net_device *netdev;
  81         struct list_head peers;
  82         atomic_t peer_count; /* number of items in peers list */
  83
  84         struct work_struct delete_netdev;
  85         struct delayed_work notify_peers;
  86 };
  87
  88 static inline struct lowpan_dev *lowpan_dev(const struct net_device *netdev)
  89 {
  90         return netdev_priv(netdev);
  91 }
  92
  93 static inline void peer_add(struct lowpan_dev *dev, struct lowpan_peer *peer)
  94 {
  95         list_add(&peer->list, &dev->peers);
  96         atomic_inc(&dev->peer_count);
  97 }
  98
  99 static inline bool peer_del(struct lowpan_dev *dev, struct lowpan_peer *peer)
 100 {
 101         list_del(&peer->list);
 102
 103         if (atomic_dec_and_test(&dev->peer_count)) {
 104                 BT_DBG("last peer");
 105                 return true;
 106         }
 107
 108         return false;
 109 }
 110
 111 static inline struct lowpan_peer *peer_lookup_ba(struct lowpan_dev *dev,
 112                                                  bdaddr_t *ba, __u8 type)
 113 {
 114         struct lowpan_peer *peer, *tmp;
 115
 116         BT_DBG("peers %d addr %pMR type %d", atomic_read(&dev->peer_count),
 117                ba, type);
 118
 119         list_for_each_entry_safe(peer, tmp, &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                         return peer;
 128         }
 129
 130         return NULL;
 131 }
 132
 133 static inline struct lowpan_peer *peer_lookup_chan(struct lowpan_dev *dev,
 134                                                    struct l2cap_chan *chan)
 135 {
 136         struct lowpan_peer *peer, *tmp;
 137
 138         list_for_each_entry_safe(peer, tmp, &dev->peers, list) {
 139                 if (peer->chan == chan)
 140                         return peer;
 141         }
 142
 143         return NULL;
 144 }
 145
 146 static inline struct lowpan_peer *peer_lookup_conn(struct lowpan_dev *dev,
 147                                                    struct l2cap_conn *conn)
 148 {
 149         struct lowpan_peer *peer, *tmp;
 150
 151         list_for_each_entry_safe(peer, tmp, &dev->peers, list) {
 152                 if (peer->chan->conn == conn)
 153                         return peer;
 154         }
 155
 156         return NULL;
 157 }
 158
 159 static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn)
 160 {
 161         struct lowpan_dev *entry, *tmp;
 162         struct lowpan_peer *peer = NULL;
 163         unsigned long flags;
 164
 165         read_lock_irqsave(&devices_lock, flags);
 166
 167         list_for_each_entry_safe(entry, tmp, &bt_6lowpan_devices, list) {
 168                 peer = peer_lookup_conn(entry, conn);
 169                 if (peer)
 170                         break;
 171         }
 172
 173         read_unlock_irqrestore(&devices_lock, flags);
 174
 175         return peer;
 176 }
 177
 178 static struct lowpan_dev *lookup_dev(struct l2cap_conn *conn)
 179 {
 180         struct lowpan_dev *entry, *tmp;
 181         struct lowpan_dev *dev = NULL;
 182         unsigned long flags;
 183
 184         read_lock_irqsave(&devices_lock, flags);
 185
 186         list_for_each_entry_safe(entry, tmp, &bt_6lowpan_devices, list) {
 187                 if (conn->hcon->hdev == entry->hdev) {
 188                         dev = entry;
 189                         break;
 190                 }
 191         }
 192
 193         read_unlock_irqrestore(&devices_lock, flags);
 194
 195         return dev;
 196 }
 197
 198 static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev)
 199 {
 200         struct sk_buff *skb_cp;
 201         int ret;
 202
 203         skb_cp = skb_copy(skb, GFP_ATOMIC);
 204         if (!skb_cp)
 205                 return -ENOMEM;
 206
 207         ret = netif_rx(skb_cp);
 208         if (ret < 0) {
 209                 BT_DBG("receive skb %d", ret);
 210                 return NET_RX_DROP;
 211         }
 212
 213         return ret;
 214 }
 215
 216 static int process_data(struct sk_buff *skb, struct net_device *netdev,
 217                         struct l2cap_chan *chan)
 218 {
 219         const u8 *saddr, *daddr;
 220         u8 iphc0, iphc1;
 221         struct lowpan_dev *dev;
 222         struct lowpan_peer *peer;
 223         unsigned long flags;
 224
 225         dev = lowpan_dev(netdev);
 226
 227         read_lock_irqsave(&devices_lock, flags);
 228         peer = peer_lookup_chan(dev, chan);
 229         read_unlock_irqrestore(&devices_lock, flags);
 230         if (!peer)
 231                 goto drop;
 232
 233         saddr = peer->eui64_addr;
 234         daddr = dev->netdev->dev_addr;
 235
 236         /* at least two bytes will be used for the encoding */
 237         if (skb->len < 2)
 238                 goto drop;
 239
 240         if (lowpan_fetch_skb_u8(skb, &iphc0))
 241                 goto drop;
 242
 243         if (lowpan_fetch_skb_u8(skb, &iphc1))
 244                 goto drop;
 245
 246         return lowpan_process_data(skb, netdev,
 247                                    saddr, IEEE802154_ADDR_LONG, EUI64_ADDR_LEN,
 248                                    daddr, IEEE802154_ADDR_LONG, EUI64_ADDR_LEN,
 249                                    iphc0, iphc1, give_skb_to_upper);
 250
 251 drop:
 252         kfree_skb(skb);
 253         return -EINVAL;
 254 }
 255
 256 static int recv_pkt(struct sk_buff *skb, struct net_device *dev,
 257                     struct l2cap_chan *chan)
 258 {
 259         struct sk_buff *local_skb;
 260         int ret;
 261
 262         if (!netif_running(dev))
 263                 goto drop;
 264
 265         if (dev->type != ARPHRD_6LOWPAN)
 266                 goto drop;
 267
 268         /* check that it's our buffer */
 269         if (skb->data[0] == LOWPAN_DISPATCH_IPV6) {
 270                 /* Copy the packet so that the IPv6 header is
 271                  * properly aligned.
 272                  */
 273                 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
 274                                             skb_tailroom(skb), GFP_ATOMIC);
 275                 if (!local_skb)
 276                         goto drop;
 277
 278                 local_skb->protocol = htons(ETH_P_IPV6);
 279                 local_skb->pkt_type = PACKET_HOST;
 280
 281                 skb_reset_network_header(local_skb);
 282                 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
 283
 284                 if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) {
 285                         kfree_skb(local_skb);
 286                         goto drop;
 287                 }
 288
 289                 dev->stats.rx_bytes += skb->len;
 290                 dev->stats.rx_packets++;
 291
 292                 kfree_skb(local_skb);
 293                 kfree_skb(skb);
 294         } else {
 295                 switch (skb->data[0] & 0xe0) {
 296                 case LOWPAN_DISPATCH_IPHC:      /* ipv6 datagram */
 297                         local_skb = skb_clone(skb, GFP_ATOMIC);
 298                         if (!local_skb)
 299                                 goto drop;
 300
 301                         ret = process_data(local_skb, dev, chan);
 302                         if (ret != NET_RX_SUCCESS)
 303                                 goto drop;
 304
 305                         dev->stats.rx_bytes += skb->len;
 306                         dev->stats.rx_packets++;
 307
 308                         kfree_skb(skb);
 309                         break;
 310                 default:
 311                         break;
 312                 }
 313         }
 314
 315         return NET_RX_SUCCESS;
 316
 317 drop:
 318         dev->stats.rx_dropped++;
 319         kfree_skb(skb);
 320         return NET_RX_DROP;
 321 }
 322
 323 /* Packet from BT LE device */
 324 static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
 325 {
 326         struct lowpan_dev *dev;
 327         struct lowpan_peer *peer;
 328         int err;
 329
 330         peer = lookup_peer(chan->conn);
 331         if (!peer)
 332                 return -ENOENT;
 333
 334         dev = lookup_dev(chan->conn);
 335         if (!dev || !dev->netdev)
 336                 return -ENOENT;
 337
 338         err = recv_pkt(skb, dev->netdev, chan);
 339         if (err) {
 340                 BT_DBG("recv pkt %d", err);
 341                 err = -EAGAIN;
 342         }
 343
 344         return err;
 345 }
 346
 347 static u8 get_addr_type_from_eui64(u8 byte)
 348 {
 349         /* Is universal(0) or local(1) bit */
 350         return ((byte & 0x02) ? BDADDR_LE_RANDOM : BDADDR_LE_PUBLIC);
 351 }
 352
 353 static void copy_to_bdaddr(struct in6_addr *ip6_daddr, bdaddr_t *addr)
 354 {
 355         u8 *eui64 = ip6_daddr->s6_addr + 8;
 356
 357         addr->b[0] = eui64[7];
 358         addr->b[1] = eui64[6];
 359         addr->b[2] = eui64[5];
 360         addr->b[3] = eui64[2];
 361         addr->b[4] = eui64[1];
 362         addr->b[5] = eui64[0];
 363 }
 364
 365 static void convert_dest_bdaddr(struct in6_addr *ip6_daddr,
 366                                 bdaddr_t *addr, u8 *addr_type)
 367 {
 368         copy_to_bdaddr(ip6_daddr, addr);
 369
 370         /* We need to toggle the U/L bit that we got from IPv6 address
 371          * so that we get the proper address and type of the BD address.
 372          */
 373         addr->b[5] ^= 0x02;
 374
 375         *addr_type = get_addr_type_from_eui64(addr->b[5]);
 376 }
 377
 378 static int header_create(struct sk_buff *skb, struct net_device *netdev,
 379                          unsigned short type, const void *_daddr,
 380                          const void *_saddr, unsigned int len)
 381 {
 382         struct ipv6hdr *hdr;
 383         struct lowpan_dev *dev;
 384         struct lowpan_peer *peer;
 385         bdaddr_t addr, *any = BDADDR_ANY;
 386         u8 *saddr, *daddr = any->b;
 387         u8 addr_type;
 388
 389         if (type != ETH_P_IPV6)
 390                 return -EINVAL;
 391
 392         hdr = ipv6_hdr(skb);
 393
 394         dev = lowpan_dev(netdev);
 395
 396         if (ipv6_addr_is_multicast(&hdr->daddr)) {
 397                 memcpy(&lowpan_cb(skb)->addr, &hdr->daddr,
 398                        sizeof(struct in6_addr));
 399                 lowpan_cb(skb)->chan = NULL;
 400         } else {
 401                 unsigned long flags;
 402
 403                 /* Get destination BT device from skb.
 404                  * If there is no such peer then discard the packet.
 405                  */
 406                 convert_dest_bdaddr(&hdr->daddr, &addr, &addr_type);
 407
 408                 BT_DBG("dest addr %pMR type %d IP %pI6c", &addr,
 409                        addr_type, &hdr->daddr);
 410
 411                 read_lock_irqsave(&devices_lock, flags);
 412                 peer = peer_lookup_ba(dev, &addr, addr_type);
 413                 read_unlock_irqrestore(&devices_lock, flags);
 414
 415                 if (!peer) {
 416                         BT_DBG("no such peer %pMR found", &addr);
 417                         return -ENOENT;
 418                 }
 419
 420                 daddr = peer->eui64_addr;
 421
 422                 memcpy(&lowpan_cb(skb)->addr, &hdr->daddr,
 423                        sizeof(struct in6_addr));
 424                 lowpan_cb(skb)->chan = peer->chan;
 425         }
 426
 427         saddr = dev->netdev->dev_addr;
 428
 429         return lowpan_header_compress(skb, netdev, type, daddr, saddr, len);
 430 }
 431
 432 /* Packet to BT LE device */
 433 static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb,
 434                     struct net_device *netdev)
 435 {
 436         struct msghdr msg;
 437         struct kvec iv;
 438         int err;
 439
 440         /* Remember the skb so that we can send EAGAIN to the caller if
 441          * we run out of credits.
 442          */
 443         chan->data = skb;
 444
 445         memset(&msg, 0, sizeof(msg));
 446         msg.msg_iov = (struct iovec *) &iv;
 447         msg.msg_iovlen = 1;
 448         iv.iov_base = skb->data;
 449         iv.iov_len = skb->len;
 450
 451         err = l2cap_chan_send(chan, &msg, skb->len);
 452         if (err > 0) {
 453                 netdev->stats.tx_bytes += err;
 454                 netdev->stats.tx_packets++;
 455                 return 0;
 456         }
 457
 458         if (!err)
 459                 err = lowpan_cb(skb)->status;
 460
 461         if (err < 0) {
 462                 if (err == -EAGAIN)
 463                         netdev->stats.tx_dropped++;
 464                 else
 465                         netdev->stats.tx_errors++;
 466         }
 467
 468         return err;
 469 }
 470
 471 static void send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev)
 472 {
 473         struct sk_buff *local_skb;
 474         struct lowpan_dev *entry, *tmp;
 475         unsigned long flags;
 476
 477         read_lock_irqsave(&devices_lock, flags);
 478
 479         list_for_each_entry_safe(entry, tmp, &bt_6lowpan_devices, list) {
 480                 struct lowpan_peer *pentry, *ptmp;
 481                 struct lowpan_dev *dev;
 482
 483                 if (entry->netdev != netdev)
 484                         continue;
 485
 486                 dev = lowpan_dev(entry->netdev);
 487
 488                 list_for_each_entry_safe(pentry, ptmp, &dev->peers, list) {
 489                         local_skb = skb_clone(skb, GFP_ATOMIC);
 490
 491                         send_pkt(pentry->chan, local_skb, netdev);
 492
 493                         kfree_skb(local_skb);
 494                 }
 495         }
 496
 497         read_unlock_irqrestore(&devices_lock, flags);
 498 }
 499
 500 static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev)
 501 {
 502         int err = 0;
 503         struct lowpan_dev *dev;
 504         struct lowpan_peer *peer;
 505         bdaddr_t addr;
 506         u8 addr_type;
 507
 508         if (ipv6_addr_is_multicast(&lowpan_cb(skb)->addr)) {
 509                 /* We need to send the packet to every device
 510                  * behind this interface.
 511                  */
 512                 send_mcast_pkt(skb, netdev);
 513         } else {
 514                 unsigned long flags;
 515
 516                 convert_dest_bdaddr(&lowpan_cb(skb)->addr, &addr, &addr_type);
 517                 dev = lowpan_dev(netdev);
 518
 519                 read_lock_irqsave(&devices_lock, flags);
 520                 peer = peer_lookup_ba(dev, &addr, addr_type);
 521                 read_unlock_irqrestore(&devices_lock, flags);
 522
 523                 BT_DBG("xmit %s to %pMR type %d IP %pI6c peer %p",
 524                        netdev->name, &addr, addr_type,
 525                        &lowpan_cb(skb)->addr, peer);
 526
 527                 if (peer && peer->chan)
 528                         err = send_pkt(peer->chan, skb, netdev);
 529                 else
 530                         err = -ENOENT;
 531         }
 532         dev_kfree_skb(skb);
 533
 534         if (err)
 535                 BT_DBG("ERROR: xmit failed (%d)", err);
 536
 537         return (err < 0) ? NET_XMIT_DROP : err;
 538 }
 539
 540 static const struct net_device_ops netdev_ops = {
 541         .ndo_start_xmit         = bt_xmit,
 542 };
 543
 544 static struct header_ops header_ops = {
 545         .create = header_create,
 546 };
 547
 548 static void netdev_setup(struct net_device *dev)
 549 {
 550         dev->addr_len           = EUI64_ADDR_LEN;
 551         dev->type               = ARPHRD_6LOWPAN;
 552
 553         dev->hard_header_len    = 0;
 554         dev->needed_tailroom    = 0;
 555         dev->mtu                = IPV6_MIN_MTU;
 556         dev->tx_queue_len       = 0;
 557         dev->flags              = IFF_RUNNING | IFF_POINTOPOINT;
 558         dev->watchdog_timeo     = 0;
 559
 560         dev->netdev_ops         = &netdev_ops;
 561         dev->header_ops         = &header_ops;
 562         dev->destructor         = free_netdev;
 563 }
 564
 565 static struct device_type bt_type = {
 566         .name   = "bluetooth",
 567 };
 568
 569 static void set_addr(u8 *eui, u8 *addr, u8 addr_type)
 570 {
 571         /* addr is the BT address in little-endian format */
 572         eui[0] = addr[5];
 573         eui[1] = addr[4];
 574         eui[2] = addr[3];
 575         eui[3] = 0xFF;
 576         eui[4] = 0xFE;
 577         eui[5] = addr[2];
 578         eui[6] = addr[1];
 579         eui[7] = addr[0];
 580
 581         /* Universal/local bit set, BT 6lowpan draft ch. 3.2.1 */
 582         if (addr_type == BDADDR_LE_PUBLIC)
 583                 eui[0] &= ~0x02;
 584         else
 585                 eui[0] |= 0x02;
 586
 587         BT_DBG("type %d addr %*phC", addr_type, 8, eui);
 588 }
 589
 590 static void set_dev_addr(struct net_device *netdev, bdaddr_t *addr,
 591                          u8 addr_type)
 592 {
 593         netdev->addr_assign_type = NET_ADDR_PERM;
 594         set_addr(netdev->dev_addr, addr->b, addr_type);
 595 }
 596
 597 static void ifup(struct net_device *netdev)
 598 {
 599         int err;
 600
 601         rtnl_lock();
 602         err = dev_open(netdev);
 603         if (err < 0)
 604                 BT_INFO("iface %s cannot be opened (%d)", netdev->name, err);
 605         rtnl_unlock();
 606 }
 607
 608 static void do_notify_peers(struct work_struct *work)
 609 {
 610         struct lowpan_dev *dev = container_of(work, struct lowpan_dev,
 611                                               notify_peers.work);
 612
 613         netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */
 614 }
 615
 616 static bool is_bt_6lowpan(struct hci_conn *hcon)
 617 {
 618         if (hcon->type != LE_LINK)
 619                 return false;
 620
 621         if (!psm_6lowpan)
 622                 return false;
 623
 624         return true;
 625 }
 626
 627 static struct l2cap_chan *chan_create(void)
 628 {
 629         struct l2cap_chan *chan;
 630
 631         chan = l2cap_chan_create();
 632         if (!chan)
 633                 return NULL;
 634
 635         l2cap_chan_set_defaults(chan);
 636
 637         chan->chan_type = L2CAP_CHAN_CONN_ORIENTED;
 638         chan->mode = L2CAP_MODE_LE_FLOWCTL;
 639         chan->omtu = 65535;
 640         chan->imtu = chan->omtu;
 641
 642         return chan;
 643 }
 644
 645 static struct l2cap_chan *chan_open(struct l2cap_chan *pchan)
 646 {
 647         struct l2cap_chan *chan;
 648
 649         chan = chan_create();
 650         if (!chan)
 651                 return NULL;
 652
 653         chan->remote_mps = chan->omtu;
 654         chan->mps = chan->omtu;
 655
 656         chan->state = BT_CONNECTED;
 657
 658         return chan;
 659 }
 660
 661 static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan,
 662                                         struct lowpan_dev *dev)
 663 {
 664         struct lowpan_peer *peer;
 665         unsigned long flags;
 666
 667         peer = kzalloc(sizeof(*peer), GFP_ATOMIC);
 668         if (!peer)
 669                 return NULL;
 670
 671         peer->chan = chan;
 672         memset(&peer->peer_addr, 0, sizeof(struct in6_addr));
 673
 674         /* RFC 2464 ch. 5 */
 675         peer->peer_addr.s6_addr[0] = 0xFE;
 676         peer->peer_addr.s6_addr[1] = 0x80;
 677         set_addr((u8 *)&peer->peer_addr.s6_addr + 8, chan->dst.b,
 678                  chan->dst_type);
 679
 680         memcpy(&peer->eui64_addr, (u8 *)&peer->peer_addr.s6_addr + 8,
 681                EUI64_ADDR_LEN);
 682
 683         write_lock_irqsave(&devices_lock, flags);
 684         INIT_LIST_HEAD(&peer->list);
 685         peer_add(dev, peer);
 686         write_unlock_irqrestore(&devices_lock, flags);
 687
 688         /* Notifying peers about us needs to be done without locks held */
 689         INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers);
 690         schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100));
 691
 692         return peer->chan;
 693 }
 694
 695 static int setup_netdev(struct l2cap_chan *chan, struct lowpan_dev **dev)
 696 {
 697         struct net_device *netdev;
 698         int err = 0;
 699         unsigned long flags;
 700
 701         netdev = alloc_netdev(sizeof(struct lowpan_dev), IFACE_NAME_TEMPLATE,
 702                               netdev_setup);
 703         if (!netdev)
 704                 return -ENOMEM;
 705
 706         set_dev_addr(netdev, &chan->src, chan->src_type);
 707
 708         netdev->netdev_ops = &netdev_ops;
 709         SET_NETDEV_DEV(netdev, &chan->conn->hcon->dev);
 710         SET_NETDEV_DEVTYPE(netdev, &bt_type);
 711
 712         err = register_netdev(netdev);
 713         if (err < 0) {
 714                 BT_INFO("register_netdev failed %d", err);
 715                 free_netdev(netdev);
 716                 goto out;
 717         }
 718
 719         BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d",
 720                netdev->ifindex, &chan->dst, chan->dst_type,
 721                &chan->src, chan->src_type);
 722         set_bit(__LINK_STATE_PRESENT, &netdev->state);
 723
 724         *dev = netdev_priv(netdev);
 725         (*dev)->netdev = netdev;
 726         (*dev)->hdev = chan->conn->hcon->hdev;
 727         INIT_LIST_HEAD(&(*dev)->peers);
 728
 729         write_lock_irqsave(&devices_lock, flags);
 730         INIT_LIST_HEAD(&(*dev)->list);
 731         list_add(&(*dev)->list, &bt_6lowpan_devices);
 732         write_unlock_irqrestore(&devices_lock, flags);
 733
 734         return 0;
 735
 736 out:
 737         return err;
 738 }
 739
 740 static inline void chan_ready_cb(struct l2cap_chan *chan)
 741 {
 742         struct lowpan_dev *dev;
 743
 744         dev = lookup_dev(chan->conn);
 745
 746         BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev);
 747
 748         if (!dev) {
 749                 if (setup_netdev(chan, &dev) < 0) {
 750                         l2cap_chan_del(chan, -ENOENT);
 751                         return;
 752                 }
 753         }
 754
 755         add_peer_chan(chan, dev);
 756         ifup(dev->netdev);
 757 }
 758
 759 static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *chan)
 760 {
 761         struct l2cap_chan *pchan;
 762
 763         pchan = chan_open(chan);
 764         pchan->ops = chan->ops;
 765
 766         BT_DBG("chan %p pchan %p", chan, pchan);
 767
 768         return pchan;
 769 }
 770
 771 static void delete_netdev(struct work_struct *work)
 772 {
 773         struct lowpan_dev *entry = container_of(work, struct lowpan_dev,
 774                                                 delete_netdev);
 775
 776         unregister_netdev(entry->netdev);
 777
 778         /* The entry pointer is deleted in device_event() */
 779 }
 780
 781 static void chan_close_cb(struct l2cap_chan *chan)
 782 {
 783         struct lowpan_dev *entry, *tmp;
 784         struct lowpan_dev *dev = NULL;
 785         struct lowpan_peer *peer;
 786         int err = -ENOENT;
 787         unsigned long flags;
 788         bool last = false, removed = true;
 789
 790         BT_DBG("chan %p conn %p", chan, chan->conn);
 791
 792         if (chan->conn && chan->conn->hcon) {
 793                 if (!is_bt_6lowpan(chan->conn->hcon))
 794                         return;
 795
 796                 /* If conn is set, then the netdev is also there and we should
 797                  * not remove it.
 798                  */
 799                 removed = false;
 800         }
 801
 802         write_lock_irqsave(&devices_lock, flags);
 803
 804         list_for_each_entry_safe(entry, tmp, &bt_6lowpan_devices, list) {
 805                 dev = lowpan_dev(entry->netdev);
 806                 peer = peer_lookup_chan(dev, chan);
 807                 if (peer) {
 808                         last = peer_del(dev, peer);
 809                         err = 0;
 810
 811                         BT_DBG("dev %p removing %speer %p", dev,
 812                                last ? "last " : "1 ", peer);
 813                         BT_DBG("chan %p orig refcnt %d", chan,
 814                                atomic_read(&chan->kref.refcount));
 815
 816                         l2cap_chan_put(chan);
 817                         kfree(peer);
 818                         break;
 819                 }
 820         }
 821
 822         if (!err && last && dev && !atomic_read(&dev->peer_count)) {
 823                 write_unlock_irqrestore(&devices_lock, flags);
 824
 825                 cancel_delayed_work_sync(&dev->notify_peers);
 826
 827                 if (!removed) {
 828                         INIT_WORK(&entry->delete_netdev, delete_netdev);
 829                         schedule_work(&entry->delete_netdev);
 830                 }
 831         } else {
 832                 write_unlock_irqrestore(&devices_lock, flags);
 833         }
 834
 835         return;
 836 }
 837
 838 static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err)
 839 {
 840         BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn,
 841                state_to_string(state), err);
 842 }
 843
 844 static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan,
 845                                          unsigned long hdr_len,
 846                                          unsigned long len, int nb)
 847 {
 848         /* Note that we must allocate using GFP_ATOMIC here as
 849          * this function is called originally from netdev hard xmit
 850          * function in atomic context.
 851          */
 852         return bt_skb_alloc(hdr_len + len, GFP_ATOMIC);
 853 }
 854
 855 static void chan_suspend_cb(struct l2cap_chan *chan)
 856 {
 857         struct sk_buff *skb = chan->data;
 858
 859         BT_DBG("chan %p conn %p skb %p", chan, chan->conn, skb);
 860
 861         lowpan_cb(skb)->status = -EAGAIN;
 862 }
 863
 864 static void chan_resume_cb(struct l2cap_chan *chan)
 865 {
 866         struct sk_buff *skb = chan->data;
 867
 868         BT_DBG("chan %p conn %p skb %p", chan, chan->conn, skb);
 869
 870         lowpan_cb(skb)->status = 0;
 871 }
 872
 873 static long chan_get_sndtimeo_cb(struct l2cap_chan *chan)
 874 {
 875         return msecs_to_jiffies(1000);
 876 }
 877
 878 static const struct l2cap_ops bt_6lowpan_chan_ops = {
 879         .name                   = "L2CAP 6LoWPAN channel",
 880         .new_connection         = chan_new_conn_cb,
 881         .recv                   = chan_recv_cb,
 882         .close                  = chan_close_cb,
 883         .state_change           = chan_state_change_cb,
 884         .ready                  = chan_ready_cb,
 885         .resume                 = chan_resume_cb,
 886         .suspend                = chan_suspend_cb,
 887         .get_sndtimeo           = chan_get_sndtimeo_cb,
 888         .alloc_skb              = chan_alloc_skb_cb,
 889         .memcpy_fromiovec       = l2cap_chan_no_memcpy_fromiovec,
 890
 891         .teardown               = l2cap_chan_no_teardown,
 892         .defer                  = l2cap_chan_no_defer,
 893         .set_shutdown           = l2cap_chan_no_set_shutdown,
 894 };
 895
 896 static inline __u8 bdaddr_type(__u8 type)
 897 {
 898         if (type == ADDR_LE_DEV_PUBLIC)
 899                 return BDADDR_LE_PUBLIC;
 900         else
 901                 return BDADDR_LE_RANDOM;
 902 }
 903
 904 static struct l2cap_chan *chan_get(void)
 905 {
 906         struct l2cap_chan *pchan;
 907
 908         pchan = chan_create();
 909         if (!pchan)
 910                 return NULL;
 911
 912         pchan->ops = &bt_6lowpan_chan_ops;
 913
 914         return pchan;
 915 }
 916
 917 static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type)
 918 {
 919         struct l2cap_chan *pchan;
 920         int err;
 921
 922         pchan = chan_get();
 923         if (!pchan)
 924                 return -EINVAL;
 925
 926         err = l2cap_chan_connect(pchan, cpu_to_le16(psm_6lowpan), 0,
 927                                  addr, dst_type);
 928
 929         BT_DBG("chan %p err %d", pchan, err);
 930         if (err < 0)
 931                 l2cap_chan_put(pchan);
 932
 933         return err;
 934 }
 935
 936 static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type)
 937 {
 938         struct lowpan_peer *peer;
 939
 940         BT_DBG("conn %p dst type %d", conn, dst_type);
 941
 942         peer = lookup_peer(conn);
 943         if (!peer)
 944                 return -ENOENT;
 945
 946         BT_DBG("peer %p chan %p", peer, peer->chan);
 947
 948         l2cap_chan_close(peer->chan, ENOENT);
 949
 950         return 0;
 951 }
 952
 953 static struct l2cap_chan *bt_6lowpan_listen(void)
 954 {
 955         bdaddr_t *addr = BDADDR_ANY;
 956         struct l2cap_chan *pchan;
 957         int err;
 958
 959         if (psm_6lowpan == 0)
 960                 return NULL;
 961
 962         pchan = chan_get();
 963         if (!pchan)
 964                 return NULL;
 965
 966         pchan->state = BT_LISTEN;
 967         pchan->src_type = BDADDR_LE_PUBLIC;
 968
 969         BT_DBG("psm 0x%04x chan %p src type %d", psm_6lowpan, pchan,
 970                pchan->src_type);
 971
 972         err = l2cap_add_psm(pchan, addr, cpu_to_le16(psm_6lowpan));
 973         if (err) {
 974                 l2cap_chan_put(pchan);
 975                 BT_ERR("psm cannot be added err %d", err);
 976                 return NULL;
 977         }
 978
 979         return pchan;
 980 }
 981
 982 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type,
 983                           struct l2cap_conn **conn)
 984 {
 985         struct hci_conn *hcon;
 986         struct hci_dev *hdev;
 987         bdaddr_t *src = BDADDR_ANY;
 988         int n;
 989
 990         n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu",
 991                    &addr->b[5], &addr->b[4], &addr->b[3],
 992                    &addr->b[2], &addr->b[1], &addr->b[0],
 993                    addr_type);
 994
 995         if (n < 7)
 996                 return -EINVAL;
 997
 998         hdev = hci_get_route(addr, src);
 999         if (!hdev)
1000                 return -ENOENT;
1001
1002         hci_dev_lock(hdev);
1003         hcon = hci_conn_hash_lookup_ba(hdev, LE_LINK, addr);
1004         hci_dev_unlock(hdev);
1005
1006         if (!hcon)
1007                 return -ENOENT;
1008
1009         *conn = (struct l2cap_conn *)hcon->l2cap_data;
1010
1011         BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type);
1012
1013         return 0;
1014 }
1015
1016 static void disconnect_all_peers(void)
1017 {
1018         struct lowpan_dev *entry, *tmp_dev;
1019         struct lowpan_peer *peer, *tmp_peer, *new_peer;
1020         struct list_head peers;
1021         unsigned long flags;
1022
1023         INIT_LIST_HEAD(&peers);
1024
1025         /* We make a separate list of peers as the close_cb() will
1026          * modify the device peers list so it is better not to mess
1027          * with the same list at the same time.
1028          */
1029
1030         read_lock_irqsave(&devices_lock, flags);
1031
1032         list_for_each_entry_safe(entry, tmp_dev, &bt_6lowpan_devices, list) {
1033                 list_for_each_entry_safe(peer, tmp_peer, &entry->peers, list) {
1034                         new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC);
1035                         if (!new_peer)
1036                                 break;
1037
1038                         new_peer->chan = peer->chan;
1039                         INIT_LIST_HEAD(&new_peer->list);
1040
1041                         list_add(&new_peer->list, &peers);
1042                 }
1043         }
1044
1045         read_unlock_irqrestore(&devices_lock, flags);
1046
1047         list_for_each_entry_safe(peer, tmp_peer, &peers, list) {
1048                 l2cap_chan_close(peer->chan, ENOENT);
1049                 kfree(peer);
1050         }
1051 }
1052
1053 static int lowpan_psm_set(void *data, u64 val)
1054 {
1055         u16 psm;
1056
1057         psm = val;
1058         if (psm == 0 || psm_6lowpan != psm)
1059                 /* Disconnect existing connections if 6lowpan is
1060                  * disabled (psm = 0), or if psm changes.
1061                  */
1062                 disconnect_all_peers();
1063
1064         psm_6lowpan = psm;
1065
1066         if (listen_chan) {
1067                 l2cap_chan_close(listen_chan, 0);
1068                 l2cap_chan_put(listen_chan);
1069         }
1070
1071         listen_chan = bt_6lowpan_listen();
1072
1073         return 0;
1074 }
1075
1076 static int lowpan_psm_get(void *data, u64 *val)
1077 {
1078         *val = psm_6lowpan;
1079         return 0;
1080 }
1081
1082 DEFINE_SIMPLE_ATTRIBUTE(lowpan_psm_fops, lowpan_psm_get,
1083                         lowpan_psm_set, "%llu\n");
1084
1085 static ssize_t lowpan_control_write(struct file *fp,
1086                                     const char __user *user_buffer,
1087                                     size_t count,
1088                                     loff_t *position)
1089 {
1090         char buf[32];
1091         size_t buf_size = min(count, sizeof(buf) - 1);
1092         int ret;
1093         bdaddr_t addr;
1094         u8 addr_type;
1095         struct l2cap_conn *conn = NULL;
1096
1097         if (copy_from_user(buf, user_buffer, buf_size))
1098                 return -EFAULT;
1099
1100         buf[buf_size] = '\0';
1101
1102         if (memcmp(buf, "connect ", 8) == 0) {
1103                 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn);
1104                 if (ret == -EINVAL)
1105                         return ret;
1106
1107                 if (listen_chan) {
1108                         l2cap_chan_close(listen_chan, 0);
1109                         l2cap_chan_put(listen_chan);
1110                         listen_chan = NULL;
1111                 }
1112
1113                 if (conn) {
1114                         struct lowpan_peer *peer;
1115
1116                         if (!is_bt_6lowpan(conn->hcon))
1117                                 return -EINVAL;
1118
1119                         peer = lookup_peer(conn);
1120                         if (peer) {
1121                                 BT_DBG("6LoWPAN connection already exists");
1122                                 return -EALREADY;
1123                         }
1124
1125                         BT_DBG("conn %p dst %pMR type %d user %d", conn,
1126                                &conn->hcon->dst, conn->hcon->dst_type,
1127                                addr_type);
1128                 }
1129
1130                 ret = bt_6lowpan_connect(&addr, addr_type);
1131                 if (ret < 0)
1132                         return ret;
1133
1134                 return count;
1135         }
1136
1137         if (memcmp(buf, "disconnect ", 11) == 0) {
1138                 ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn);
1139                 if (ret < 0)
1140                         return ret;
1141
1142                 ret = bt_6lowpan_disconnect(conn, addr_type);
1143                 if (ret < 0)
1144                         return ret;
1145
1146                 return count;
1147         }
1148
1149         return count;
1150 }
1151
1152 static int lowpan_control_show(struct seq_file *f, void *ptr)
1153 {
1154         struct lowpan_dev *entry, *tmp_dev;
1155         struct lowpan_peer *peer, *tmp_peer;
1156         unsigned long flags;
1157
1158         read_lock_irqsave(&devices_lock, flags);
1159
1160         list_for_each_entry_safe(entry, tmp_dev, &bt_6lowpan_devices, list) {
1161                 list_for_each_entry_safe(peer, tmp_peer, &entry->peers, list)
1162                         seq_printf(f, "%pMR (type %u)\n",
1163                                    &peer->chan->dst, peer->chan->dst_type);
1164         }
1165
1166         read_unlock_irqrestore(&devices_lock, flags);
1167
1168         return 0;
1169 }
1170
1171 static int lowpan_control_open(struct inode *inode, struct file *file)
1172 {
1173         return single_open(file, lowpan_control_show, inode->i_private);
1174 }
1175
1176 static const struct file_operations lowpan_control_fops = {
1177         .open           = lowpan_control_open,
1178         .read           = seq_read,
1179         .write          = lowpan_control_write,
1180         .llseek         = seq_lseek,
1181         .release        = single_release,
1182 };
1183
1184 static int device_event(struct notifier_block *unused,
1185                         unsigned long event, void *ptr)
1186 {
1187         struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
1188         struct lowpan_dev *entry, *tmp;
1189         unsigned long flags;
1190
1191         if (netdev->type != ARPHRD_6LOWPAN)
1192                 return NOTIFY_DONE;
1193
1194         switch (event) {
1195         case NETDEV_UNREGISTER:
1196                 write_lock_irqsave(&devices_lock, flags);
1197                 list_for_each_entry_safe(entry, tmp, &bt_6lowpan_devices,
1198                                          list) {
1199                         if (entry->netdev == netdev) {
1200                                 list_del(&entry->list);
1201                                 kfree(entry);
1202                                 break;
1203                         }
1204                 }
1205                 write_unlock_irqrestore(&devices_lock, flags);
1206                 break;
1207         }
1208
1209         return NOTIFY_DONE;
1210 }
1211
1212 static struct notifier_block bt_6lowpan_dev_notifier = {
1213         .notifier_call = device_event,
1214 };
1215
1216 static int __init bt_6lowpan_init(void)
1217 {
1218         lowpan_psm_debugfs = debugfs_create_file("6lowpan_psm", 0644,
1219                                                  bt_debugfs, NULL,
1220                                                  &lowpan_psm_fops);
1221         lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644,
1222                                                      bt_debugfs, NULL,
1223                                                      &lowpan_control_fops);
1224
1225         return register_netdevice_notifier(&bt_6lowpan_dev_notifier);
1226 }
1227
1228 static void __exit bt_6lowpan_exit(void)
1229 {
1230         debugfs_remove(lowpan_psm_debugfs);
1231         debugfs_remove(lowpan_control_debugfs);
1232
1233         if (listen_chan) {
1234                 l2cap_chan_close(listen_chan, 0);
1235                 l2cap_chan_put(listen_chan);
1236         }
1237
1238         unregister_netdevice_notifier(&bt_6lowpan_dev_notifier);
1239 }
1240
1241 module_init(bt_6lowpan_init);
1242 module_exit(bt_6lowpan_exit);
1243
1244 MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>");
1245 MODULE_DESCRIPTION("Bluetooth 6LoWPAN");
1246 MODULE_VERSION(VERSION);
1247 MODULE_LICENSE("GPL");