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         module_put(THIS_MODULE);
 104
 105         if (atomic_dec_and_test(&dev->peer_count)) {
 106                 BT_DBG("last peer");
 107                 return true;
 108         }
 109
 110         return false;
 111 }
 112
 113 static inline struct lowpan_peer *peer_lookup_ba(struct lowpan_dev *dev,
 114                                                  bdaddr_t *ba, __u8 type)
 115 {
 116         struct lowpan_peer *peer, *tmp;
 117
 118         BT_DBG("peers %d addr %pMR type %d", atomic_read(&dev->peer_count),
 119                ba, type);
 120
 121         list_for_each_entry_safe(peer, tmp, &dev->peers, list) {
 122                 BT_DBG("dst addr %pMR dst type %d",
 123                        &peer->chan->dst, peer->chan->dst_type);
 124
 125                 if (bacmp(&peer->chan->dst, ba))
 126                         continue;
 127
 128                 if (type == peer->chan->dst_type)
 129                         return peer;
 130         }
 131
 132         return NULL;
 133 }
 134
 135 static inline struct lowpan_peer *peer_lookup_chan(struct lowpan_dev *dev,
 136                                                    struct l2cap_chan *chan)
 137 {
 138         struct lowpan_peer *peer, *tmp;
 139
 140         list_for_each_entry_safe(peer, tmp, &dev->peers, list) {
 141                 if (peer->chan == chan)
 142                         return peer;
 143         }
 144
 145         return NULL;
 146 }
 147
 148 static inline struct lowpan_peer *peer_lookup_conn(struct lowpan_dev *dev,
 149                                                    struct l2cap_conn *conn)
 150 {
 151         struct lowpan_peer *peer, *tmp;
 152
 153         list_for_each_entry_safe(peer, tmp, &dev->peers, list) {
 154                 if (peer->chan->conn == conn)
 155                         return peer;
 156         }
 157
 158         return NULL;
 159 }
 160
 161 static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn)
 162 {
 163         struct lowpan_dev *entry, *tmp;
 164         struct lowpan_peer *peer = NULL;
 165         unsigned long flags;
 166
 167         read_lock_irqsave(&devices_lock, flags);
 168
 169         list_for_each_entry_safe(entry, tmp, &bt_6lowpan_devices, list) {
 170                 peer = peer_lookup_conn(entry, conn);
 171                 if (peer)
 172                         break;
 173         }
 174
 175         read_unlock_irqrestore(&devices_lock, flags);
 176
 177         return peer;
 178 }
 179
 180 static struct lowpan_dev *lookup_dev(struct l2cap_conn *conn)
 181 {
 182         struct lowpan_dev *entry, *tmp;
 183         struct lowpan_dev *dev = NULL;
 184         unsigned long flags;
 185
 186         read_lock_irqsave(&devices_lock, flags);
 187
 188         list_for_each_entry_safe(entry, tmp, &bt_6lowpan_devices, list) {
 189                 if (conn->hcon->hdev == entry->hdev) {
 190                         dev = entry;
 191                         break;
 192                 }
 193         }
 194
 195         read_unlock_irqrestore(&devices_lock, flags);
 196
 197         return dev;
 198 }
 199
 200 static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev)
 201 {
 202         struct sk_buff *skb_cp;
 203         int ret;
 204
 205         skb_cp = skb_copy(skb, GFP_ATOMIC);
 206         if (!skb_cp)
 207                 return -ENOMEM;
 208
 209         ret = netif_rx(skb_cp);
 210         if (ret < 0) {
 211                 BT_DBG("receive skb %d", ret);
 212                 return NET_RX_DROP;
 213         }
 214
 215         return ret;
 216 }
 217
 218 static int process_data(struct sk_buff *skb, struct net_device *netdev,
 219                         struct l2cap_chan *chan)
 220 {
 221         const u8 *saddr, *daddr;
 222         u8 iphc0, iphc1;
 223         struct lowpan_dev *dev;
 224         struct lowpan_peer *peer;
 225         unsigned long flags;
 226
 227         dev = lowpan_dev(netdev);
 228
 229         read_lock_irqsave(&devices_lock, flags);
 230         peer = peer_lookup_chan(dev, chan);
 231         read_unlock_irqrestore(&devices_lock, flags);
 232         if (!peer)
 233                 goto drop;
 234
 235         saddr = peer->eui64_addr;
 236         daddr = dev->netdev->dev_addr;
 237
 238         /* at least two bytes will be used for the encoding */
 239         if (skb->len < 2)
 240                 goto drop;
 241
 242         if (lowpan_fetch_skb_u8(skb, &iphc0))
 243                 goto drop;
 244
 245         if (lowpan_fetch_skb_u8(skb, &iphc1))
 246                 goto drop;
 247
 248         return lowpan_process_data(skb, netdev,
 249                                    saddr, IEEE802154_ADDR_LONG, EUI64_ADDR_LEN,
 250                                    daddr, IEEE802154_ADDR_LONG, EUI64_ADDR_LEN,
 251                                    iphc0, iphc1, give_skb_to_upper);
 252
 253 drop:
 254         kfree_skb(skb);
 255         return -EINVAL;
 256 }
 257
 258 static int recv_pkt(struct sk_buff *skb, struct net_device *dev,
 259                     struct l2cap_chan *chan)
 260 {
 261         struct sk_buff *local_skb;
 262         int ret;
 263
 264         if (!netif_running(dev))
 265                 goto drop;
 266
 267         if (dev->type != ARPHRD_6LOWPAN)
 268                 goto drop;
 269
 270         /* check that it's our buffer */
 271         if (skb->data[0] == LOWPAN_DISPATCH_IPV6) {
 272                 /* Copy the packet so that the IPv6 header is
 273                  * properly aligned.
 274                  */
 275                 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
 276                                             skb_tailroom(skb), GFP_ATOMIC);
 277                 if (!local_skb)
 278                         goto drop;
 279
 280                 local_skb->protocol = htons(ETH_P_IPV6);
 281                 local_skb->pkt_type = PACKET_HOST;
 282
 283                 skb_reset_network_header(local_skb);
 284                 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
 285
 286                 if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) {
 287                         kfree_skb(local_skb);
 288                         goto drop;
 289                 }
 290
 291                 dev->stats.rx_bytes += skb->len;
 292                 dev->stats.rx_packets++;
 293
 294                 kfree_skb(local_skb);
 295                 kfree_skb(skb);
 296         } else {
 297                 switch (skb->data[0] & 0xe0) {
 298                 case LOWPAN_DISPATCH_IPHC:      /* ipv6 datagram */
 299                         local_skb = skb_clone(skb, GFP_ATOMIC);
 300                         if (!local_skb)
 301                                 goto drop;
 302
 303                         ret = process_data(local_skb, dev, chan);
 304                         if (ret != NET_RX_SUCCESS)
 305                                 goto drop;
 306
 307                         dev->stats.rx_bytes += skb->len;
 308                         dev->stats.rx_packets++;
 309
 310                         kfree_skb(skb);
 311                         break;
 312                 default:
 313                         break;
 314                 }
 315         }
 316
 317         return NET_RX_SUCCESS;
 318
 319 drop:
 320         dev->stats.rx_dropped++;
 321         kfree_skb(skb);
 322         return NET_RX_DROP;
 323 }
 324
 325 /* Packet from BT LE device */
 326 static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
 327 {
 328         struct lowpan_dev *dev;
 329         struct lowpan_peer *peer;
 330         int err;
 331
 332         peer = lookup_peer(chan->conn);
 333         if (!peer)
 334                 return -ENOENT;
 335
 336         dev = lookup_dev(chan->conn);
 337         if (!dev || !dev->netdev)
 338                 return -ENOENT;
 339
 340         err = recv_pkt(skb, dev->netdev, chan);
 341         if (err) {
 342                 BT_DBG("recv pkt %d", err);
 343                 err = -EAGAIN;
 344         }
 345
 346         return err;
 347 }
 348
 349 static u8 get_addr_type_from_eui64(u8 byte)
 350 {
 351         /* Is universal(0) or local(1) bit */
 352         return ((byte & 0x02) ? BDADDR_LE_RANDOM : BDADDR_LE_PUBLIC);
 353 }
 354
 355 static void copy_to_bdaddr(struct in6_addr *ip6_daddr, bdaddr_t *addr)
 356 {
 357         u8 *eui64 = ip6_daddr->s6_addr + 8;
 358
 359         addr->b[0] = eui64[7];
 360         addr->b[1] = eui64[6];
 361         addr->b[2] = eui64[5];
 362         addr->b[3] = eui64[2];
 363         addr->b[4] = eui64[1];
 364         addr->b[5] = eui64[0];
 365 }
 366
 367 static void convert_dest_bdaddr(struct in6_addr *ip6_daddr,
 368                                 bdaddr_t *addr, u8 *addr_type)
 369 {
 370         copy_to_bdaddr(ip6_daddr, addr);
 371
 372         /* We need to toggle the U/L bit that we got from IPv6 address
 373          * so that we get the proper address and type of the BD address.
 374          */
 375         addr->b[5] ^= 0x02;
 376
 377         *addr_type = get_addr_type_from_eui64(addr->b[5]);
 378 }
 379
 380 static int header_create(struct sk_buff *skb, struct net_device *netdev,
 381                          unsigned short type, const void *_daddr,
 382                          const void *_saddr, unsigned int len)
 383 {
 384         struct ipv6hdr *hdr;
 385         struct lowpan_dev *dev;
 386         struct lowpan_peer *peer;
 387         bdaddr_t addr, *any = BDADDR_ANY;
 388         u8 *saddr, *daddr = any->b;
 389         u8 addr_type;
 390
 391         if (type != ETH_P_IPV6)
 392                 return -EINVAL;
 393
 394         hdr = ipv6_hdr(skb);
 395
 396         dev = lowpan_dev(netdev);
 397
 398         if (ipv6_addr_is_multicast(&hdr->daddr)) {
 399                 memcpy(&lowpan_cb(skb)->addr, &hdr->daddr,
 400                        sizeof(struct in6_addr));
 401                 lowpan_cb(skb)->chan = NULL;
 402         } else {
 403                 unsigned long flags;
 404
 405                 /* Get destination BT device from skb.
 406                  * If there is no such peer then discard the packet.
 407                  */
 408                 convert_dest_bdaddr(&hdr->daddr, &addr, &addr_type);
 409
 410                 BT_DBG("dest addr %pMR type %d IP %pI6c", &addr,
 411                        addr_type, &hdr->daddr);
 412
 413                 read_lock_irqsave(&devices_lock, flags);
 414                 peer = peer_lookup_ba(dev, &addr, addr_type);
 415                 read_unlock_irqrestore(&devices_lock, flags);
 416
 417                 if (!peer) {
 418                         BT_DBG("no such peer %pMR found", &addr);
 419                         return -ENOENT;
 420                 }
 421
 422                 daddr = peer->eui64_addr;
 423
 424                 memcpy(&lowpan_cb(skb)->addr, &hdr->daddr,
 425                        sizeof(struct in6_addr));
 426                 lowpan_cb(skb)->chan = peer->chan;
 427         }
 428
 429         saddr = dev->netdev->dev_addr;
 430
 431         return lowpan_header_compress(skb, netdev, type, daddr, saddr, len);
 432 }
 433
 434 /* Packet to BT LE device */
 435 static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb,
 436                     struct net_device *netdev)
 437 {
 438         struct msghdr msg;
 439         struct kvec iv;
 440         int err;
 441
 442         /* Remember the skb so that we can send EAGAIN to the caller if
 443          * we run out of credits.
 444          */
 445         chan->data = skb;
 446
 447         memset(&msg, 0, sizeof(msg));
 448         msg.msg_iov = (struct iovec *) &iv;
 449         msg.msg_iovlen = 1;
 450         iv.iov_base = skb->data;
 451         iv.iov_len = skb->len;
 452
 453         err = l2cap_chan_send(chan, &msg, skb->len);
 454         if (err > 0) {
 455                 netdev->stats.tx_bytes += err;
 456                 netdev->stats.tx_packets++;
 457                 return 0;
 458         }
 459
 460         if (!err)
 461                 err = lowpan_cb(skb)->status;
 462
 463         if (err < 0) {
 464                 if (err == -EAGAIN)
 465                         netdev->stats.tx_dropped++;
 466                 else
 467                         netdev->stats.tx_errors++;
 468         }
 469
 470         return err;
 471 }
 472
 473 static void send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev)
 474 {
 475         struct sk_buff *local_skb;
 476         struct lowpan_dev *entry, *tmp;
 477         unsigned long flags;
 478
 479         read_lock_irqsave(&devices_lock, flags);
 480
 481         list_for_each_entry_safe(entry, tmp, &bt_6lowpan_devices, list) {
 482                 struct lowpan_peer *pentry, *ptmp;
 483                 struct lowpan_dev *dev;
 484
 485                 if (entry->netdev != netdev)
 486                         continue;
 487
 488                 dev = lowpan_dev(entry->netdev);
 489
 490                 list_for_each_entry_safe(pentry, ptmp, &dev->peers, list) {
 491                         local_skb = skb_clone(skb, GFP_ATOMIC);
 492
 493                         send_pkt(pentry->chan, local_skb, netdev);
 494
 495                         kfree_skb(local_skb);
 496                 }
 497         }
 498
 499         read_unlock_irqrestore(&devices_lock, flags);
 500 }
 501
 502 static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev)
 503 {
 504         int err = 0;
 505         struct lowpan_dev *dev;
 506         struct lowpan_peer *peer;
 507         bdaddr_t addr;
 508         u8 addr_type;
 509
 510         if (ipv6_addr_is_multicast(&lowpan_cb(skb)->addr)) {
 511                 /* We need to send the packet to every device
 512                  * behind this interface.
 513                  */
 514                 send_mcast_pkt(skb, netdev);
 515         } else {
 516                 unsigned long flags;
 517
 518                 convert_dest_bdaddr(&lowpan_cb(skb)->addr, &addr, &addr_type);
 519                 dev = lowpan_dev(netdev);
 520
 521                 read_lock_irqsave(&devices_lock, flags);
 522                 peer = peer_lookup_ba(dev, &addr, addr_type);
 523                 read_unlock_irqrestore(&devices_lock, flags);
 524
 525                 BT_DBG("xmit %s to %pMR type %d IP %pI6c peer %p",
 526                        netdev->name, &addr, addr_type,
 527                        &lowpan_cb(skb)->addr, peer);
 528
 529                 if (peer && peer->chan)
 530                         err = send_pkt(peer->chan, skb, netdev);
 531                 else
 532                         err = -ENOENT;
 533         }
 534         dev_kfree_skb(skb);
 535
 536         if (err)
 537                 BT_DBG("ERROR: xmit failed (%d)", err);
 538
 539         return (err < 0) ? NET_XMIT_DROP : err;
 540 }
 541
 542 static const struct net_device_ops netdev_ops = {
 543         .ndo_start_xmit         = bt_xmit,
 544 };
 545
 546 static struct header_ops header_ops = {
 547         .create = header_create,
 548 };
 549
 550 static void netdev_setup(struct net_device *dev)
 551 {
 552         dev->addr_len           = EUI64_ADDR_LEN;
 553         dev->type               = ARPHRD_6LOWPAN;
 554
 555         dev->hard_header_len    = 0;
 556         dev->needed_tailroom    = 0;
 557         dev->mtu                = IPV6_MIN_MTU;
 558         dev->tx_queue_len       = 0;
 559         dev->flags              = IFF_RUNNING | IFF_POINTOPOINT;
 560         dev->watchdog_timeo     = 0;
 561
 562         dev->netdev_ops         = &netdev_ops;
 563         dev->header_ops         = &header_ops;
 564         dev->destructor         = free_netdev;
 565 }
 566
 567 static struct device_type bt_type = {
 568         .name   = "bluetooth",
 569 };
 570
 571 static void set_addr(u8 *eui, u8 *addr, u8 addr_type)
 572 {
 573         /* addr is the BT address in little-endian format */
 574         eui[0] = addr[5];
 575         eui[1] = addr[4];
 576         eui[2] = addr[3];
 577         eui[3] = 0xFF;
 578         eui[4] = 0xFE;
 579         eui[5] = addr[2];
 580         eui[6] = addr[1];
 581         eui[7] = addr[0];
 582
 583         /* Universal/local bit set, BT 6lowpan draft ch. 3.2.1 */
 584         if (addr_type == BDADDR_LE_PUBLIC)
 585                 eui[0] &= ~0x02;
 586         else
 587                 eui[0] |= 0x02;
 588
 589         BT_DBG("type %d addr %*phC", addr_type, 8, eui);
 590 }
 591
 592 static void set_dev_addr(struct net_device *netdev, bdaddr_t *addr,
 593                          u8 addr_type)
 594 {
 595         netdev->addr_assign_type = NET_ADDR_PERM;
 596         set_addr(netdev->dev_addr, addr->b, addr_type);
 597 }
 598
 599 static void ifup(struct net_device *netdev)
 600 {
 601         int err;
 602
 603         rtnl_lock();
 604         err = dev_open(netdev);
 605         if (err < 0)
 606                 BT_INFO("iface %s cannot be opened (%d)", netdev->name, err);
 607         rtnl_unlock();
 608 }
 609
 610 static void do_notify_peers(struct work_struct *work)
 611 {
 612         struct lowpan_dev *dev = container_of(work, struct lowpan_dev,
 613                                               notify_peers.work);
 614
 615         netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */
 616 }
 617
 618 static bool is_bt_6lowpan(struct hci_conn *hcon)
 619 {
 620         if (hcon->type != LE_LINK)
 621                 return false;
 622
 623         if (!psm_6lowpan)
 624                 return false;
 625
 626         return true;
 627 }
 628
 629 static struct l2cap_chan *chan_create(void)
 630 {
 631         struct l2cap_chan *chan;
 632
 633         chan = l2cap_chan_create();
 634         if (!chan)
 635                 return NULL;
 636
 637         l2cap_chan_set_defaults(chan);
 638
 639         chan->chan_type = L2CAP_CHAN_CONN_ORIENTED;
 640         chan->mode = L2CAP_MODE_LE_FLOWCTL;
 641         chan->omtu = 65535;
 642         chan->imtu = chan->omtu;
 643
 644         return chan;
 645 }
 646
 647 static struct l2cap_chan *chan_open(struct l2cap_chan *pchan)
 648 {
 649         struct l2cap_chan *chan;
 650
 651         chan = chan_create();
 652         if (!chan)
 653                 return NULL;
 654
 655         chan->remote_mps = chan->omtu;
 656         chan->mps = chan->omtu;
 657
 658         chan->state = BT_CONNECTED;
 659
 660         return chan;
 661 }
 662
 663 static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan,
 664                                         struct lowpan_dev *dev)
 665 {
 666         struct lowpan_peer *peer;
 667         unsigned long flags;
 668
 669         peer = kzalloc(sizeof(*peer), GFP_ATOMIC);
 670         if (!peer)
 671                 return NULL;
 672
 673         peer->chan = chan;
 674         memset(&peer->peer_addr, 0, sizeof(struct in6_addr));
 675
 676         /* RFC 2464 ch. 5 */
 677         peer->peer_addr.s6_addr[0] = 0xFE;
 678         peer->peer_addr.s6_addr[1] = 0x80;
 679         set_addr((u8 *)&peer->peer_addr.s6_addr + 8, chan->dst.b,
 680                  chan->dst_type);
 681
 682         memcpy(&peer->eui64_addr, (u8 *)&peer->peer_addr.s6_addr + 8,
 683                EUI64_ADDR_LEN);
 684
 685         write_lock_irqsave(&devices_lock, flags);
 686         INIT_LIST_HEAD(&peer->list);
 687         peer_add(dev, peer);
 688         write_unlock_irqrestore(&devices_lock, flags);
 689
 690         /* Notifying peers about us needs to be done without locks held */
 691         INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers);
 692         schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100));
 693
 694         return peer->chan;
 695 }
 696
 697 static int setup_netdev(struct l2cap_chan *chan, struct lowpan_dev **dev)
 698 {
 699         struct net_device *netdev;
 700         int err = 0;
 701         unsigned long flags;
 702
 703         netdev = alloc_netdev(sizeof(struct lowpan_dev), IFACE_NAME_TEMPLATE,
 704                               netdev_setup);
 705         if (!netdev)
 706                 return -ENOMEM;
 707
 708         set_dev_addr(netdev, &chan->src, chan->src_type);
 709
 710         netdev->netdev_ops = &netdev_ops;
 711         SET_NETDEV_DEV(netdev, &chan->conn->hcon->dev);
 712         SET_NETDEV_DEVTYPE(netdev, &bt_type);
 713
 714         err = register_netdev(netdev);
 715         if (err < 0) {
 716                 BT_INFO("register_netdev failed %d", err);
 717                 free_netdev(netdev);
 718                 goto out;
 719         }
 720
 721         BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d",
 722                netdev->ifindex, &chan->dst, chan->dst_type,
 723                &chan->src, chan->src_type);
 724         set_bit(__LINK_STATE_PRESENT, &netdev->state);
 725
 726         *dev = netdev_priv(netdev);
 727         (*dev)->netdev = netdev;
 728         (*dev)->hdev = chan->conn->hcon->hdev;
 729         INIT_LIST_HEAD(&(*dev)->peers);
 730
 731         write_lock_irqsave(&devices_lock, flags);
 732         INIT_LIST_HEAD(&(*dev)->list);
 733         list_add(&(*dev)->list, &bt_6lowpan_devices);
 734         write_unlock_irqrestore(&devices_lock, flags);
 735
 736         return 0;
 737
 738 out:
 739         return err;
 740 }
 741
 742 static inline void chan_ready_cb(struct l2cap_chan *chan)
 743 {
 744         struct lowpan_dev *dev;
 745
 746         dev = lookup_dev(chan->conn);
 747
 748         BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev);
 749
 750         if (!dev) {
 751                 if (setup_netdev(chan, &dev) < 0) {
 752                         l2cap_chan_del(chan, -ENOENT);
 753                         return;
 754                 }
 755         }
 756
 757         if (!try_module_get(THIS_MODULE))
 758                 return;
 759
 760         add_peer_chan(chan, dev);
 761         ifup(dev->netdev);
 762 }
 763
 764 static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *chan)
 765 {
 766         struct l2cap_chan *pchan;
 767
 768         pchan = chan_open(chan);
 769         pchan->ops = chan->ops;
 770
 771         BT_DBG("chan %p pchan %p", chan, pchan);
 772
 773         return pchan;
 774 }
 775
 776 static void delete_netdev(struct work_struct *work)
 777 {
 778         struct lowpan_dev *entry = container_of(work, struct lowpan_dev,
 779                                                 delete_netdev);
 780
 781         unregister_netdev(entry->netdev);
 782
 783         /* The entry pointer is deleted in device_event() */
 784 }
 785
 786 static void chan_close_cb(struct l2cap_chan *chan)
 787 {
 788         struct lowpan_dev *entry, *tmp;
 789         struct lowpan_dev *dev = NULL;
 790         struct lowpan_peer *peer;
 791         int err = -ENOENT;
 792         unsigned long flags;
 793         bool last = false, removed = true;
 794
 795         BT_DBG("chan %p conn %p", chan, chan->conn);
 796
 797         if (chan->conn && chan->conn->hcon) {
 798                 if (!is_bt_6lowpan(chan->conn->hcon))
 799                         return;
 800
 801                 /* If conn is set, then the netdev is also there and we should
 802                  * not remove it.
 803                  */
 804                 removed = false;
 805         }
 806
 807         write_lock_irqsave(&devices_lock, flags);
 808
 809         list_for_each_entry_safe(entry, tmp, &bt_6lowpan_devices, list) {
 810                 dev = lowpan_dev(entry->netdev);
 811                 peer = peer_lookup_chan(dev, chan);
 812                 if (peer) {
 813                         last = peer_del(dev, peer);
 814                         err = 0;
 815
 816                         BT_DBG("dev %p removing %speer %p", dev,
 817                                last ? "last " : "1 ", peer);
 818                         BT_DBG("chan %p orig refcnt %d", chan,
 819                                atomic_read(&chan->kref.refcount));
 820
 821                         l2cap_chan_put(chan);
 822                         kfree(peer);
 823                         break;
 824                 }
 825         }
 826
 827         if (!err && last && dev && !atomic_read(&dev->peer_count)) {
 828                 write_unlock_irqrestore(&devices_lock, flags);
 829
 830                 cancel_delayed_work_sync(&dev->notify_peers);
 831
 832                 if (!removed) {
 833                         INIT_WORK(&entry->delete_netdev, delete_netdev);
 834                         schedule_work(&entry->delete_netdev);
 835                 }
 836         } else {
 837                 write_unlock_irqrestore(&devices_lock, flags);
 838         }
 839
 840         return;
 841 }
 842
 843 static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err)
 844 {
 845         BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn,
 846                state_to_string(state), err);
 847 }
 848
 849 static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan,
 850                                          unsigned long hdr_len,
 851                                          unsigned long len, int nb)
 852 {
 853         /* Note that we must allocate using GFP_ATOMIC here as
 854          * this function is called originally from netdev hard xmit
 855          * function in atomic context.
 856          */
 857         return bt_skb_alloc(hdr_len + len, GFP_ATOMIC);
 858 }
 859
 860 static void chan_suspend_cb(struct l2cap_chan *chan)
 861 {
 862         struct sk_buff *skb = chan->data;
 863
 864         BT_DBG("chan %p conn %p skb %p", chan, chan->conn, skb);
 865
 866         lowpan_cb(skb)->status = -EAGAIN;
 867 }
 868
 869 static void chan_resume_cb(struct l2cap_chan *chan)
 870 {
 871         struct sk_buff *skb = chan->data;
 872
 873         BT_DBG("chan %p conn %p skb %p", chan, chan->conn, skb);
 874
 875         lowpan_cb(skb)->status = 0;
 876 }
 877
 878 static long chan_get_sndtimeo_cb(struct l2cap_chan *chan)
 879 {
 880         return msecs_to_jiffies(1000);
 881 }
 882
 883 static const struct l2cap_ops bt_6lowpan_chan_ops = {
 884         .name                   = "L2CAP 6LoWPAN channel",
 885         .new_connection         = chan_new_conn_cb,
 886         .recv                   = chan_recv_cb,
 887         .close                  = chan_close_cb,
 888         .state_change           = chan_state_change_cb,
 889         .ready                  = chan_ready_cb,
 890         .resume                 = chan_resume_cb,
 891         .suspend                = chan_suspend_cb,
 892         .get_sndtimeo           = chan_get_sndtimeo_cb,
 893         .alloc_skb              = chan_alloc_skb_cb,
 894         .memcpy_fromiovec       = l2cap_chan_no_memcpy_fromiovec,
 895
 896         .teardown               = l2cap_chan_no_teardown,
 897         .defer                  = l2cap_chan_no_defer,
 898         .set_shutdown           = l2cap_chan_no_set_shutdown,
 899 };
 900
 901 static inline __u8 bdaddr_type(__u8 type)
 902 {
 903         if (type == ADDR_LE_DEV_PUBLIC)
 904                 return BDADDR_LE_PUBLIC;
 905         else
 906                 return BDADDR_LE_RANDOM;
 907 }
 908
 909 static struct l2cap_chan *chan_get(void)
 910 {
 911         struct l2cap_chan *pchan;
 912
 913         pchan = chan_create();
 914         if (!pchan)
 915                 return NULL;
 916
 917         pchan->ops = &bt_6lowpan_chan_ops;
 918
 919         return pchan;
 920 }
 921
 922 static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type)
 923 {
 924         struct l2cap_chan *pchan;
 925         int err;
 926
 927         pchan = chan_get();
 928         if (!pchan)
 929                 return -EINVAL;
 930
 931         err = l2cap_chan_connect(pchan, cpu_to_le16(psm_6lowpan), 0,
 932                                  addr, dst_type);
 933
 934         BT_DBG("chan %p err %d", pchan, err);
 935         if (err < 0)
 936                 l2cap_chan_put(pchan);
 937
 938         return err;
 939 }
 940
 941 static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type)
 942 {
 943         struct lowpan_peer *peer;
 944
 945         BT_DBG("conn %p dst type %d", conn, dst_type);
 946
 947         peer = lookup_peer(conn);
 948         if (!peer)
 949                 return -ENOENT;
 950
 951         BT_DBG("peer %p chan %p", peer, peer->chan);
 952
 953         l2cap_chan_close(peer->chan, ENOENT);
 954
 955         return 0;
 956 }
 957
 958 static struct l2cap_chan *bt_6lowpan_listen(void)
 959 {
 960         bdaddr_t *addr = BDADDR_ANY;
 961         struct l2cap_chan *pchan;
 962         int err;
 963
 964         if (psm_6lowpan == 0)
 965                 return NULL;
 966
 967         pchan = chan_get();
 968         if (!pchan)
 969                 return NULL;
 970
 971         pchan->state = BT_LISTEN;
 972         pchan->src_type = BDADDR_LE_PUBLIC;
 973
 974         BT_DBG("psm 0x%04x chan %p src type %d", psm_6lowpan, pchan,
 975                pchan->src_type);
 976
 977         err = l2cap_add_psm(pchan, addr, cpu_to_le16(psm_6lowpan));
 978         if (err) {
 979                 l2cap_chan_put(pchan);
 980                 BT_ERR("psm cannot be added err %d", err);
 981                 return NULL;
 982         }
 983
 984         return pchan;
 985 }
 986
 987 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type,
 988                           struct l2cap_conn **conn)
 989 {
 990         struct hci_conn *hcon;
 991         struct hci_dev *hdev;
 992         bdaddr_t *src = BDADDR_ANY;
 993         int n;
 994
 995         n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu",
 996                    &addr->b[5], &addr->b[4], &addr->b[3],
 997                    &addr->b[2], &addr->b[1], &addr->b[0],
 998                    addr_type);
 999
1000         if (n < 7)
1001                 return -EINVAL;
1002
1003         hdev = hci_get_route(addr, src);
1004         if (!hdev)
1005                 return -ENOENT;
1006
1007         hci_dev_lock(hdev);
1008         hcon = hci_conn_hash_lookup_ba(hdev, LE_LINK, addr);
1009         hci_dev_unlock(hdev);
1010
1011         if (!hcon)
1012                 return -ENOENT;
1013
1014         *conn = (struct l2cap_conn *)hcon->l2cap_data;
1015
1016         BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type);
1017
1018         return 0;
1019 }
1020
1021 static void disconnect_all_peers(void)
1022 {
1023         struct lowpan_dev *entry, *tmp_dev;
1024         struct lowpan_peer *peer, *tmp_peer, *new_peer;
1025         struct list_head peers;
1026         unsigned long flags;
1027
1028         INIT_LIST_HEAD(&peers);
1029
1030         /* We make a separate list of peers as the close_cb() will
1031          * modify the device peers list so it is better not to mess
1032          * with the same list at the same time.
1033          */
1034
1035         read_lock_irqsave(&devices_lock, flags);
1036
1037         list_for_each_entry_safe(entry, tmp_dev, &bt_6lowpan_devices, list) {
1038                 list_for_each_entry_safe(peer, tmp_peer, &entry->peers, list) {
1039                         new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC);
1040                         if (!new_peer)
1041                                 break;
1042
1043                         new_peer->chan = peer->chan;
1044                         INIT_LIST_HEAD(&new_peer->list);
1045
1046                         list_add(&new_peer->list, &peers);
1047                 }
1048         }
1049
1050         read_unlock_irqrestore(&devices_lock, flags);
1051
1052         list_for_each_entry_safe(peer, tmp_peer, &peers, list) {
1053                 l2cap_chan_close(peer->chan, ENOENT);
1054                 kfree(peer);
1055         }
1056 }
1057
1058 static int lowpan_psm_set(void *data, u64 val)
1059 {
1060         u16 psm;
1061
1062         psm = val;
1063         if (psm == 0 || psm_6lowpan != psm)
1064                 /* Disconnect existing connections if 6lowpan is
1065                  * disabled (psm = 0), or if psm changes.
1066                  */
1067                 disconnect_all_peers();
1068
1069         psm_6lowpan = psm;
1070
1071         if (listen_chan) {
1072                 l2cap_chan_close(listen_chan, 0);
1073                 l2cap_chan_put(listen_chan);
1074         }
1075
1076         listen_chan = bt_6lowpan_listen();
1077
1078         return 0;
1079 }
1080
1081 static int lowpan_psm_get(void *data, u64 *val)
1082 {
1083         *val = psm_6lowpan;
1084         return 0;
1085 }
1086
1087 DEFINE_SIMPLE_ATTRIBUTE(lowpan_psm_fops, lowpan_psm_get,
1088                         lowpan_psm_set, "%llu\n");
1089
1090 static ssize_t lowpan_control_write(struct file *fp,
1091                                     const char __user *user_buffer,
1092                                     size_t count,
1093                                     loff_t *position)
1094 {
1095         char buf[32];
1096         size_t buf_size = min(count, sizeof(buf) - 1);
1097         int ret;
1098         bdaddr_t addr;
1099         u8 addr_type;
1100         struct l2cap_conn *conn = NULL;
1101
1102         if (copy_from_user(buf, user_buffer, buf_size))
1103                 return -EFAULT;
1104
1105         buf[buf_size] = '\0';
1106
1107         if (memcmp(buf, "connect ", 8) == 0) {
1108                 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn);
1109                 if (ret == -EINVAL)
1110                         return ret;
1111
1112                 if (listen_chan) {
1113                         l2cap_chan_close(listen_chan, 0);
1114                         l2cap_chan_put(listen_chan);
1115                         listen_chan = NULL;
1116                 }
1117
1118                 if (conn) {
1119                         struct lowpan_peer *peer;
1120
1121                         if (!is_bt_6lowpan(conn->hcon))
1122                                 return -EINVAL;
1123
1124                         peer = lookup_peer(conn);
1125                         if (peer) {
1126                                 BT_DBG("6LoWPAN connection already exists");
1127                                 return -EALREADY;
1128                         }
1129
1130                         BT_DBG("conn %p dst %pMR type %d user %d", conn,
1131                                &conn->hcon->dst, conn->hcon->dst_type,
1132                                addr_type);
1133                 }
1134
1135                 ret = bt_6lowpan_connect(&addr, addr_type);
1136                 if (ret < 0)
1137                         return ret;
1138
1139                 return count;
1140         }
1141
1142         if (memcmp(buf, "disconnect ", 11) == 0) {
1143                 ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn);
1144                 if (ret < 0)
1145                         return ret;
1146
1147                 ret = bt_6lowpan_disconnect(conn, addr_type);
1148                 if (ret < 0)
1149                         return ret;
1150
1151                 return count;
1152         }
1153
1154         return count;
1155 }
1156
1157 static int lowpan_control_show(struct seq_file *f, void *ptr)
1158 {
1159         struct lowpan_dev *entry, *tmp_dev;
1160         struct lowpan_peer *peer, *tmp_peer;
1161         unsigned long flags;
1162
1163         read_lock_irqsave(&devices_lock, flags);
1164
1165         list_for_each_entry_safe(entry, tmp_dev, &bt_6lowpan_devices, list) {
1166                 list_for_each_entry_safe(peer, tmp_peer, &entry->peers, list)
1167                         seq_printf(f, "%pMR (type %u)\n",
1168                                    &peer->chan->dst, peer->chan->dst_type);
1169         }
1170
1171         read_unlock_irqrestore(&devices_lock, flags);
1172
1173         return 0;
1174 }
1175
1176 static int lowpan_control_open(struct inode *inode, struct file *file)
1177 {
1178         return single_open(file, lowpan_control_show, inode->i_private);
1179 }
1180
1181 static const struct file_operations lowpan_control_fops = {
1182         .open           = lowpan_control_open,
1183         .read           = seq_read,
1184         .write          = lowpan_control_write,
1185         .llseek         = seq_lseek,
1186         .release        = single_release,
1187 };
1188
1189 static int device_event(struct notifier_block *unused,
1190                         unsigned long event, void *ptr)
1191 {
1192         struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
1193         struct lowpan_dev *entry, *tmp;
1194         unsigned long flags;
1195
1196         if (netdev->type != ARPHRD_6LOWPAN)
1197                 return NOTIFY_DONE;
1198
1199         switch (event) {
1200         case NETDEV_UNREGISTER:
1201                 write_lock_irqsave(&devices_lock, flags);
1202                 list_for_each_entry_safe(entry, tmp, &bt_6lowpan_devices,
1203                                          list) {
1204                         if (entry->netdev == netdev) {
1205                                 list_del(&entry->list);
1206                                 kfree(entry);
1207                                 break;
1208                         }
1209                 }
1210                 write_unlock_irqrestore(&devices_lock, flags);
1211                 break;
1212         }
1213
1214         return NOTIFY_DONE;
1215 }
1216
1217 static struct notifier_block bt_6lowpan_dev_notifier = {
1218         .notifier_call = device_event,
1219 };
1220
1221 static int __init bt_6lowpan_init(void)
1222 {
1223         lowpan_psm_debugfs = debugfs_create_file("6lowpan_psm", 0644,
1224                                                  bt_debugfs, NULL,
1225                                                  &lowpan_psm_fops);
1226         lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644,
1227                                                      bt_debugfs, NULL,
1228                                                      &lowpan_control_fops);
1229
1230         return register_netdevice_notifier(&bt_6lowpan_dev_notifier);
1231 }
1232
1233 static void __exit bt_6lowpan_exit(void)
1234 {
1235         debugfs_remove(lowpan_psm_debugfs);
1236         debugfs_remove(lowpan_control_debugfs);
1237
1238         if (listen_chan) {
1239                 l2cap_chan_close(listen_chan, 0);
1240                 l2cap_chan_put(listen_chan);
1241         }
1242
1243         unregister_netdevice_notifier(&bt_6lowpan_dev_notifier);
1244 }
1245
1246 module_init(bt_6lowpan_init);
1247 module_exit(bt_6lowpan_exit);
1248
1249 MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>");
1250 MODULE_DESCRIPTION("Bluetooth 6LoWPAN");
1251 MODULE_VERSION(VERSION);
1252 MODULE_LICENSE("GPL");