1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 Copyright (c) 2013-2014 Intel Corp. 4 5 */ 6 7 #include <linux/if_arp.h> 8 #include <linux/netdevice.h> 9 #include <linux/etherdevice.h> 10 #include <linux/module.h> 11 #include <linux/debugfs.h> 12 13 #include <net/ipv6.h> 14 #include <net/ip6_route.h> 15 #include <net/addrconf.h> 16 #include <net/pkt_sched.h> 17 18 #include <net/bluetooth/bluetooth.h> 19 #include <net/bluetooth/hci_core.h> 20 #include <net/bluetooth/l2cap.h> 21 22 #include <net/6lowpan.h> /* for the compression support */ 23 24 #define VERSION "0.1" 25 26 static struct dentry *lowpan_enable_debugfs; 27 static struct dentry *lowpan_control_debugfs; 28 29 #define IFACE_NAME_TEMPLATE "bt%d" 30 31 struct skb_cb { 32 struct in6_addr addr; 33 struct in6_addr gw; 34 struct l2cap_chan *chan; 35 }; 36 #define lowpan_cb(skb) ((struct skb_cb *)((skb)->cb)) 37 38 /* The devices list contains those devices that we are acting 39 * as a proxy. The BT 6LoWPAN device is a virtual device that 40 * connects to the Bluetooth LE device. The real connection to 41 * BT device is done via l2cap layer. There exists one 42 * virtual device / one BT 6LoWPAN network (=hciX device). 43 * The list contains struct lowpan_dev elements. 44 */ 45 static LIST_HEAD(bt_6lowpan_devices); 46 static DEFINE_SPINLOCK(devices_lock); 47 48 static bool enable_6lowpan; 49 50 /* We are listening incoming connections via this channel 51 */ 52 static struct l2cap_chan *listen_chan; 53 static DEFINE_MUTEX(set_lock); 54 55 struct lowpan_peer { 56 struct list_head list; 57 struct rcu_head rcu; 58 struct l2cap_chan *chan; 59 60 /* peer addresses in various formats */ 61 unsigned char lladdr[ETH_ALEN]; 62 struct in6_addr peer_addr; 63 }; 64 65 struct lowpan_btle_dev { 66 struct list_head list; 67 68 struct hci_dev *hdev; 69 struct net_device *netdev; 70 struct list_head peers; 71 atomic_t peer_count; /* number of items in peers list */ 72 73 struct work_struct delete_netdev; 74 struct delayed_work notify_peers; 75 }; 76 77 static inline struct lowpan_btle_dev * 78 lowpan_btle_dev(const struct net_device *netdev) 79 { 80 return (struct lowpan_btle_dev *)lowpan_dev(netdev)->priv; 81 } 82 83 static inline void peer_add(struct lowpan_btle_dev *dev, 84 struct lowpan_peer *peer) 85 { 86 list_add_rcu(&peer->list, &dev->peers); 87 atomic_inc(&dev->peer_count); 88 } 89 90 static inline bool peer_del(struct lowpan_btle_dev *dev, 91 struct lowpan_peer *peer) 92 { 93 list_del_rcu(&peer->list); 94 kfree_rcu(peer, rcu); 95 96 module_put(THIS_MODULE); 97 98 if (atomic_dec_and_test(&dev->peer_count)) { 99 BT_DBG("last peer"); 100 return true; 101 } 102 103 return false; 104 } 105 106 static inline struct lowpan_peer * 107 __peer_lookup_chan(struct lowpan_btle_dev *dev, struct l2cap_chan *chan) 108 { 109 struct lowpan_peer *peer; 110 111 list_for_each_entry_rcu(peer, &dev->peers, list) { 112 if (peer->chan == chan) 113 return peer; 114 } 115 116 return NULL; 117 } 118 119 static inline struct lowpan_peer * 120 __peer_lookup_conn(struct lowpan_btle_dev *dev, struct l2cap_conn *conn) 121 { 122 struct lowpan_peer *peer; 123 124 list_for_each_entry_rcu(peer, &dev->peers, list) { 125 if (peer->chan->conn == conn) 126 return peer; 127 } 128 129 return NULL; 130 } 131 132 static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_btle_dev *dev, 133 struct in6_addr *daddr, 134 struct sk_buff *skb) 135 { 136 struct rt6_info *rt = dst_rt6_info(skb_dst(skb)); 137 int count = atomic_read(&dev->peer_count); 138 const struct in6_addr *nexthop; 139 struct lowpan_peer *peer; 140 struct neighbour *neigh; 141 142 BT_DBG("peers %d addr %pI6c rt %p", count, daddr, rt); 143 144 if (!rt) { 145 if (ipv6_addr_any(&lowpan_cb(skb)->gw)) { 146 /* There is neither route nor gateway, 147 * probably the destination is a direct peer. 148 */ 149 nexthop = daddr; 150 } else { 151 /* There is a known gateway 152 */ 153 nexthop = &lowpan_cb(skb)->gw; 154 } 155 } else { 156 nexthop = rt6_nexthop(rt, daddr); 157 158 /* We need to remember the address because it is needed 159 * by bt_xmit() when sending the packet. In bt_xmit(), the 160 * destination routing info is not set. 161 */ 162 memcpy(&lowpan_cb(skb)->gw, nexthop, sizeof(struct in6_addr)); 163 } 164 165 BT_DBG("gw %pI6c", nexthop); 166 167 rcu_read_lock(); 168 169 list_for_each_entry_rcu(peer, &dev->peers, list) { 170 BT_DBG("dst addr %pMR dst type %u ip %pI6c", 171 &peer->chan->dst, peer->chan->dst_type, 172 &peer->peer_addr); 173 174 if (!ipv6_addr_cmp(&peer->peer_addr, nexthop)) { 175 rcu_read_unlock(); 176 return peer; 177 } 178 } 179 180 /* use the neighbour cache for matching addresses assigned by SLAAC */ 181 neigh = __ipv6_neigh_lookup(dev->netdev, nexthop); 182 if (neigh) { 183 list_for_each_entry_rcu(peer, &dev->peers, list) { 184 if (!memcmp(neigh->ha, peer->lladdr, ETH_ALEN)) { 185 neigh_release(neigh); 186 rcu_read_unlock(); 187 return peer; 188 } 189 } 190 neigh_release(neigh); 191 } 192 193 rcu_read_unlock(); 194 195 return NULL; 196 } 197 198 static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn) 199 { 200 struct lowpan_btle_dev *entry; 201 struct lowpan_peer *peer = NULL; 202 203 rcu_read_lock(); 204 205 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 206 peer = __peer_lookup_conn(entry, conn); 207 if (peer) 208 break; 209 } 210 211 rcu_read_unlock(); 212 213 return peer; 214 } 215 216 static struct lowpan_btle_dev *lookup_dev(struct l2cap_conn *conn) 217 { 218 struct lowpan_btle_dev *entry; 219 struct lowpan_btle_dev *dev = NULL; 220 221 rcu_read_lock(); 222 223 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 224 if (conn->hcon->hdev == entry->hdev) { 225 dev = entry; 226 break; 227 } 228 } 229 230 rcu_read_unlock(); 231 232 return dev; 233 } 234 235 static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev) 236 { 237 struct sk_buff *skb_cp; 238 239 skb_cp = skb_copy(skb, GFP_ATOMIC); 240 if (!skb_cp) 241 return NET_RX_DROP; 242 243 return netif_rx(skb_cp); 244 } 245 246 static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev, 247 struct lowpan_peer *peer) 248 { 249 const u8 *saddr; 250 251 saddr = peer->lladdr; 252 253 return lowpan_header_decompress(skb, netdev, netdev->dev_addr, saddr); 254 } 255 256 static int recv_pkt(struct sk_buff *skb, struct net_device *dev, 257 struct lowpan_peer *peer) 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 || !skb->len) 266 goto drop; 267 268 skb_reset_network_header(skb); 269 270 skb = skb_share_check(skb, GFP_ATOMIC); 271 if (!skb) 272 goto drop; 273 274 /* check that it's our buffer */ 275 if (lowpan_is_ipv6(*skb_network_header(skb))) { 276 /* Pull off the 1-byte of 6lowpan header. */ 277 skb_pull(skb, 1); 278 279 /* Copy the packet so that the IPv6 header is 280 * properly aligned. 281 */ 282 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1, 283 skb_tailroom(skb), GFP_ATOMIC); 284 if (!local_skb) 285 goto drop; 286 287 local_skb->protocol = htons(ETH_P_IPV6); 288 local_skb->pkt_type = PACKET_HOST; 289 local_skb->dev = dev; 290 291 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr)); 292 293 if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) { 294 kfree_skb(local_skb); 295 goto drop; 296 } 297 298 dev->stats.rx_bytes += skb->len; 299 dev->stats.rx_packets++; 300 301 consume_skb(local_skb); 302 consume_skb(skb); 303 } else if (lowpan_is_iphc(*skb_network_header(skb))) { 304 local_skb = skb_clone(skb, GFP_ATOMIC); 305 if (!local_skb) 306 goto drop; 307 308 local_skb->dev = dev; 309 310 ret = iphc_decompress(local_skb, dev, peer); 311 if (ret < 0) { 312 BT_DBG("iphc_decompress failed: %d", ret); 313 kfree_skb(local_skb); 314 goto drop; 315 } 316 317 local_skb->protocol = htons(ETH_P_IPV6); 318 local_skb->pkt_type = PACKET_HOST; 319 320 if (give_skb_to_upper(local_skb, dev) 321 != NET_RX_SUCCESS) { 322 kfree_skb(local_skb); 323 goto drop; 324 } 325 326 dev->stats.rx_bytes += skb->len; 327 dev->stats.rx_packets++; 328 329 consume_skb(local_skb); 330 consume_skb(skb); 331 } else { 332 BT_DBG("unknown packet type"); 333 goto drop; 334 } 335 336 return NET_RX_SUCCESS; 337 338 drop: 339 dev->stats.rx_dropped++; 340 return NET_RX_DROP; 341 } 342 343 /* Packet from BT LE device */ 344 static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) 345 { 346 struct lowpan_btle_dev *dev; 347 struct lowpan_peer *peer; 348 int err; 349 350 peer = lookup_peer(chan->conn); 351 if (!peer) 352 return -ENOENT; 353 354 dev = lookup_dev(chan->conn); 355 if (!dev || !dev->netdev) 356 return -ENOENT; 357 358 err = recv_pkt(skb, dev->netdev, peer); 359 if (err) { 360 BT_DBG("recv pkt %d", err); 361 err = -EAGAIN; 362 } 363 364 return err; 365 } 366 367 static int setup_header(struct sk_buff *skb, struct net_device *netdev, 368 bdaddr_t *peer_addr, u8 *peer_addr_type) 369 { 370 struct in6_addr ipv6_daddr; 371 struct ipv6hdr *hdr; 372 struct lowpan_btle_dev *dev; 373 struct lowpan_peer *peer; 374 u8 *daddr; 375 int err, status = 0; 376 377 hdr = ipv6_hdr(skb); 378 379 dev = lowpan_btle_dev(netdev); 380 381 memcpy(&ipv6_daddr, &hdr->daddr, sizeof(ipv6_daddr)); 382 383 if (ipv6_addr_is_multicast(&ipv6_daddr)) { 384 lowpan_cb(skb)->chan = NULL; 385 daddr = NULL; 386 } else { 387 BT_DBG("dest IP %pI6c", &ipv6_daddr); 388 389 /* The packet might be sent to 6lowpan interface 390 * because of routing (either via default route 391 * or user set route) so get peer according to 392 * the destination address. 393 */ 394 peer = peer_lookup_dst(dev, &ipv6_daddr, skb); 395 if (!peer) { 396 BT_DBG("no such peer"); 397 return -ENOENT; 398 } 399 400 daddr = peer->lladdr; 401 *peer_addr = peer->chan->dst; 402 *peer_addr_type = peer->chan->dst_type; 403 lowpan_cb(skb)->chan = peer->chan; 404 405 status = 1; 406 } 407 408 lowpan_header_compress(skb, netdev, daddr, dev->netdev->dev_addr); 409 410 err = dev_hard_header(skb, netdev, ETH_P_IPV6, NULL, NULL, 0); 411 if (err < 0) 412 return err; 413 414 return status; 415 } 416 417 static int header_create(struct sk_buff *skb, struct net_device *netdev, 418 unsigned short type, const void *_daddr, 419 const void *_saddr, unsigned int len) 420 { 421 if (type != ETH_P_IPV6) 422 return -EINVAL; 423 424 return 0; 425 } 426 427 /* Packet to BT LE device */ 428 static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb, 429 struct net_device *netdev) 430 { 431 struct msghdr msg; 432 struct kvec iv; 433 int err; 434 435 /* Remember the skb so that we can send EAGAIN to the caller if 436 * we run out of credits. 437 */ 438 chan->data = skb; 439 440 iv.iov_base = skb->data; 441 iv.iov_len = skb->len; 442 443 memset(&msg, 0, sizeof(msg)); 444 iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, &iv, 1, skb->len); 445 446 err = l2cap_chan_send(chan, &msg, skb->len); 447 if (err > 0) { 448 netdev->stats.tx_bytes += err; 449 netdev->stats.tx_packets++; 450 return 0; 451 } 452 453 if (err < 0) 454 netdev->stats.tx_errors++; 455 456 return err; 457 } 458 459 static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev) 460 { 461 struct sk_buff *local_skb; 462 struct lowpan_btle_dev *entry; 463 int err = 0; 464 465 rcu_read_lock(); 466 467 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 468 struct lowpan_peer *pentry; 469 struct lowpan_btle_dev *dev; 470 471 if (entry->netdev != netdev) 472 continue; 473 474 dev = lowpan_btle_dev(entry->netdev); 475 476 list_for_each_entry_rcu(pentry, &dev->peers, list) { 477 int ret; 478 479 local_skb = skb_clone(skb, GFP_ATOMIC); 480 481 BT_DBG("xmit %s to %pMR type %u IP %pI6c chan %p", 482 netdev->name, 483 &pentry->chan->dst, pentry->chan->dst_type, 484 &pentry->peer_addr, pentry->chan); 485 ret = send_pkt(pentry->chan, local_skb, netdev); 486 if (ret < 0) 487 err = ret; 488 489 kfree_skb(local_skb); 490 } 491 } 492 493 rcu_read_unlock(); 494 495 return err; 496 } 497 498 static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev) 499 { 500 int err = 0; 501 bdaddr_t addr; 502 u8 addr_type; 503 504 /* We must take a copy of the skb before we modify/replace the ipv6 505 * header as the header could be used elsewhere 506 */ 507 skb = skb_unshare(skb, GFP_ATOMIC); 508 if (!skb) 509 return NET_XMIT_DROP; 510 511 /* Return values from setup_header() 512 * <0 - error, packet is dropped 513 * 0 - this is a multicast packet 514 * 1 - this is unicast packet 515 */ 516 err = setup_header(skb, netdev, &addr, &addr_type); 517 if (err < 0) { 518 kfree_skb(skb); 519 return NET_XMIT_DROP; 520 } 521 522 if (err) { 523 if (lowpan_cb(skb)->chan) { 524 BT_DBG("xmit %s to %pMR type %u IP %pI6c chan %p", 525 netdev->name, &addr, addr_type, 526 &lowpan_cb(skb)->addr, lowpan_cb(skb)->chan); 527 err = send_pkt(lowpan_cb(skb)->chan, skb, netdev); 528 } else { 529 err = -ENOENT; 530 } 531 } else { 532 /* We need to send the packet to every device behind this 533 * interface. 534 */ 535 err = send_mcast_pkt(skb, netdev); 536 } 537 538 dev_kfree_skb(skb); 539 540 if (err) 541 BT_DBG("ERROR: xmit failed (%d)", err); 542 543 return err < 0 ? NET_XMIT_DROP : err; 544 } 545 546 static int bt_dev_init(struct net_device *dev) 547 { 548 netdev_lockdep_set_classes(dev); 549 550 return 0; 551 } 552 553 static const struct net_device_ops netdev_ops = { 554 .ndo_init = bt_dev_init, 555 .ndo_start_xmit = bt_xmit, 556 }; 557 558 static const struct header_ops header_ops = { 559 .create = header_create, 560 }; 561 562 static void netdev_setup(struct net_device *dev) 563 { 564 dev->hard_header_len = 0; 565 dev->needed_tailroom = 0; 566 dev->flags = IFF_RUNNING | IFF_MULTICAST; 567 dev->watchdog_timeo = 0; 568 dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN; 569 570 dev->netdev_ops = &netdev_ops; 571 dev->header_ops = &header_ops; 572 dev->needs_free_netdev = true; 573 } 574 575 static struct device_type bt_type = { 576 .name = "bluetooth", 577 }; 578 579 static void ifup(struct net_device *netdev) 580 { 581 int err; 582 583 rtnl_lock(); 584 err = dev_open(netdev, NULL); 585 if (err < 0) 586 BT_INFO("iface %s cannot be opened (%d)", netdev->name, err); 587 rtnl_unlock(); 588 } 589 590 static void ifdown(struct net_device *netdev) 591 { 592 rtnl_lock(); 593 dev_close(netdev); 594 rtnl_unlock(); 595 } 596 597 static void do_notify_peers(struct work_struct *work) 598 { 599 struct lowpan_btle_dev *dev = container_of(work, struct lowpan_btle_dev, 600 notify_peers.work); 601 602 netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */ 603 } 604 605 static bool is_bt_6lowpan(struct hci_conn *hcon) 606 { 607 if (hcon->type != LE_LINK) 608 return false; 609 610 if (!enable_6lowpan) 611 return false; 612 613 return true; 614 } 615 616 static struct l2cap_chan *chan_create(void) 617 { 618 struct l2cap_chan *chan; 619 620 chan = l2cap_chan_create(); 621 if (!chan) 622 return NULL; 623 624 l2cap_chan_set_defaults(chan); 625 626 chan->chan_type = L2CAP_CHAN_CONN_ORIENTED; 627 chan->mode = L2CAP_MODE_LE_FLOWCTL; 628 chan->imtu = 1280; 629 630 return chan; 631 } 632 633 static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan, 634 struct lowpan_btle_dev *dev, 635 bool new_netdev) 636 { 637 struct lowpan_peer *peer; 638 639 peer = kzalloc(sizeof(*peer), GFP_ATOMIC); 640 if (!peer) 641 return NULL; 642 643 peer->chan = chan; 644 645 baswap((void *)peer->lladdr, &chan->dst); 646 647 lowpan_iphc_uncompress_eui48_lladdr(&peer->peer_addr, peer->lladdr); 648 649 spin_lock(&devices_lock); 650 INIT_LIST_HEAD(&peer->list); 651 peer_add(dev, peer); 652 spin_unlock(&devices_lock); 653 654 /* Notifying peers about us needs to be done without locks held */ 655 if (new_netdev) 656 INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers); 657 schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100)); 658 659 return peer->chan; 660 } 661 662 static int setup_netdev(struct l2cap_chan *chan, struct lowpan_btle_dev **dev) 663 { 664 struct net_device *netdev; 665 bdaddr_t addr; 666 int err; 667 668 netdev = alloc_netdev(LOWPAN_PRIV_SIZE(sizeof(struct lowpan_btle_dev)), 669 IFACE_NAME_TEMPLATE, NET_NAME_UNKNOWN, 670 netdev_setup); 671 if (!netdev) 672 return -ENOMEM; 673 674 netdev->addr_assign_type = NET_ADDR_PERM; 675 baswap(&addr, &chan->src); 676 __dev_addr_set(netdev, &addr, sizeof(addr)); 677 678 netdev->netdev_ops = &netdev_ops; 679 SET_NETDEV_DEV(netdev, &chan->conn->hcon->hdev->dev); 680 SET_NETDEV_DEVTYPE(netdev, &bt_type); 681 682 *dev = lowpan_btle_dev(netdev); 683 (*dev)->netdev = netdev; 684 (*dev)->hdev = chan->conn->hcon->hdev; 685 INIT_LIST_HEAD(&(*dev)->peers); 686 687 spin_lock(&devices_lock); 688 INIT_LIST_HEAD(&(*dev)->list); 689 list_add_rcu(&(*dev)->list, &bt_6lowpan_devices); 690 spin_unlock(&devices_lock); 691 692 err = lowpan_register_netdev(netdev, LOWPAN_LLTYPE_BTLE); 693 if (err < 0) { 694 BT_INFO("register_netdev failed %d", err); 695 spin_lock(&devices_lock); 696 list_del_rcu(&(*dev)->list); 697 spin_unlock(&devices_lock); 698 free_netdev(netdev); 699 goto out; 700 } 701 702 BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d", 703 netdev->ifindex, &chan->dst, chan->dst_type, 704 &chan->src, chan->src_type); 705 set_bit(__LINK_STATE_PRESENT, &netdev->state); 706 707 return 0; 708 709 out: 710 return err; 711 } 712 713 static inline void chan_ready_cb(struct l2cap_chan *chan) 714 { 715 struct lowpan_btle_dev *dev; 716 bool new_netdev = false; 717 718 dev = lookup_dev(chan->conn); 719 720 BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev); 721 722 if (!dev) { 723 if (setup_netdev(chan, &dev) < 0) { 724 l2cap_chan_del(chan, -ENOENT); 725 return; 726 } 727 new_netdev = true; 728 } 729 730 if (!try_module_get(THIS_MODULE)) 731 return; 732 733 add_peer_chan(chan, dev, new_netdev); 734 ifup(dev->netdev); 735 } 736 737 static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan) 738 { 739 struct l2cap_chan *chan; 740 741 chan = chan_create(); 742 if (!chan) 743 return NULL; 744 745 chan->ops = pchan->ops; 746 747 BT_DBG("chan %p pchan %p", chan, pchan); 748 749 return chan; 750 } 751 752 static void delete_netdev(struct work_struct *work) 753 { 754 struct lowpan_btle_dev *entry = container_of(work, 755 struct lowpan_btle_dev, 756 delete_netdev); 757 758 lowpan_unregister_netdev(entry->netdev); 759 760 /* The entry pointer is deleted by the netdev destructor. */ 761 } 762 763 static void chan_close_cb(struct l2cap_chan *chan) 764 { 765 struct lowpan_btle_dev *entry; 766 struct lowpan_btle_dev *dev = NULL; 767 struct lowpan_peer *peer; 768 int err = -ENOENT; 769 bool last = false, remove = true; 770 771 BT_DBG("chan %p conn %p", chan, chan->conn); 772 773 if (chan->conn && chan->conn->hcon) { 774 if (!is_bt_6lowpan(chan->conn->hcon)) 775 return; 776 777 /* If conn is set, then the netdev is also there and we should 778 * not remove it. 779 */ 780 remove = false; 781 } 782 783 spin_lock(&devices_lock); 784 785 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 786 dev = lowpan_btle_dev(entry->netdev); 787 peer = __peer_lookup_chan(dev, chan); 788 if (peer) { 789 last = peer_del(dev, peer); 790 err = 0; 791 792 BT_DBG("dev %p removing %speer %p", dev, 793 last ? "last " : "1 ", peer); 794 BT_DBG("chan %p orig refcnt %u", chan, 795 kref_read(&chan->kref)); 796 797 l2cap_chan_put(chan); 798 break; 799 } 800 } 801 802 if (!err && last && dev && !atomic_read(&dev->peer_count)) { 803 spin_unlock(&devices_lock); 804 805 cancel_delayed_work_sync(&dev->notify_peers); 806 807 ifdown(dev->netdev); 808 809 if (remove) { 810 INIT_WORK(&entry->delete_netdev, delete_netdev); 811 schedule_work(&entry->delete_netdev); 812 } 813 } else { 814 spin_unlock(&devices_lock); 815 } 816 } 817 818 static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err) 819 { 820 BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn, 821 state_to_string(state), err); 822 } 823 824 static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan, 825 unsigned long hdr_len, 826 unsigned long len, int nb) 827 { 828 struct sk_buff *skb; 829 830 /* Note that we must allocate using GFP_ATOMIC here as 831 * this function is called originally from netdev hard xmit 832 * function in atomic context. 833 */ 834 skb = bt_skb_alloc(hdr_len + len, GFP_ATOMIC); 835 if (!skb) 836 return ERR_PTR(-ENOMEM); 837 return skb; 838 } 839 840 static void chan_suspend_cb(struct l2cap_chan *chan) 841 { 842 struct lowpan_btle_dev *dev; 843 844 BT_DBG("chan %p suspend", chan); 845 846 dev = lookup_dev(chan->conn); 847 if (!dev || !dev->netdev) 848 return; 849 850 netif_stop_queue(dev->netdev); 851 } 852 853 static void chan_resume_cb(struct l2cap_chan *chan) 854 { 855 struct lowpan_btle_dev *dev; 856 857 BT_DBG("chan %p resume", chan); 858 859 dev = lookup_dev(chan->conn); 860 if (!dev || !dev->netdev) 861 return; 862 863 netif_wake_queue(dev->netdev); 864 } 865 866 static long chan_get_sndtimeo_cb(struct l2cap_chan *chan) 867 { 868 return L2CAP_CONN_TIMEOUT; 869 } 870 871 static const struct l2cap_ops bt_6lowpan_chan_ops = { 872 .name = "L2CAP 6LoWPAN channel", 873 .new_connection = chan_new_conn_cb, 874 .recv = chan_recv_cb, 875 .close = chan_close_cb, 876 .state_change = chan_state_change_cb, 877 .ready = chan_ready_cb, 878 .resume = chan_resume_cb, 879 .suspend = chan_suspend_cb, 880 .get_sndtimeo = chan_get_sndtimeo_cb, 881 .alloc_skb = chan_alloc_skb_cb, 882 883 .teardown = l2cap_chan_no_teardown, 884 .defer = l2cap_chan_no_defer, 885 .set_shutdown = l2cap_chan_no_set_shutdown, 886 }; 887 888 static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type) 889 { 890 struct l2cap_chan *chan; 891 int err; 892 893 chan = chan_create(); 894 if (!chan) 895 return -EINVAL; 896 897 chan->ops = &bt_6lowpan_chan_ops; 898 899 err = l2cap_chan_connect(chan, cpu_to_le16(L2CAP_PSM_IPSP), 0, 900 addr, dst_type); 901 902 BT_DBG("chan %p err %d", chan, err); 903 if (err < 0) 904 l2cap_chan_put(chan); 905 906 return err; 907 } 908 909 static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type) 910 { 911 struct lowpan_peer *peer; 912 913 BT_DBG("conn %p dst type %u", conn, dst_type); 914 915 peer = lookup_peer(conn); 916 if (!peer) 917 return -ENOENT; 918 919 BT_DBG("peer %p chan %p", peer, peer->chan); 920 921 l2cap_chan_close(peer->chan, ENOENT); 922 923 return 0; 924 } 925 926 static struct l2cap_chan *bt_6lowpan_listen(void) 927 { 928 bdaddr_t *addr = BDADDR_ANY; 929 struct l2cap_chan *chan; 930 int err; 931 932 if (!enable_6lowpan) 933 return NULL; 934 935 chan = chan_create(); 936 if (!chan) 937 return NULL; 938 939 chan->ops = &bt_6lowpan_chan_ops; 940 chan->state = BT_LISTEN; 941 chan->src_type = BDADDR_LE_PUBLIC; 942 943 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT); 944 945 BT_DBG("chan %p src type %u", chan, chan->src_type); 946 947 err = l2cap_add_psm(chan, addr, cpu_to_le16(L2CAP_PSM_IPSP)); 948 if (err) { 949 l2cap_chan_put(chan); 950 BT_ERR("psm cannot be added err %d", err); 951 return NULL; 952 } 953 954 return chan; 955 } 956 957 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type, 958 struct l2cap_conn **conn) 959 { 960 struct hci_conn *hcon; 961 struct hci_dev *hdev; 962 int n; 963 964 n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu", 965 &addr->b[5], &addr->b[4], &addr->b[3], 966 &addr->b[2], &addr->b[1], &addr->b[0], 967 addr_type); 968 969 if (n < 7) 970 return -EINVAL; 971 972 /* The LE_PUBLIC address type is ignored because of BDADDR_ANY */ 973 hdev = hci_get_route(addr, BDADDR_ANY, BDADDR_LE_PUBLIC); 974 if (!hdev) 975 return -ENOENT; 976 977 hci_dev_lock(hdev); 978 hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type); 979 hci_dev_unlock(hdev); 980 hci_dev_put(hdev); 981 982 if (!hcon) 983 return -ENOENT; 984 985 *conn = (struct l2cap_conn *)hcon->l2cap_data; 986 987 BT_DBG("conn %p dst %pMR type %u", *conn, &hcon->dst, hcon->dst_type); 988 989 return 0; 990 } 991 992 static void disconnect_all_peers(void) 993 { 994 struct lowpan_btle_dev *entry; 995 struct lowpan_peer *peer, *tmp_peer, *new_peer; 996 struct list_head peers; 997 998 INIT_LIST_HEAD(&peers); 999 1000 /* We make a separate list of peers as the close_cb() will 1001 * modify the device peers list so it is better not to mess 1002 * with the same list at the same time. 1003 */ 1004 1005 rcu_read_lock(); 1006 1007 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 1008 list_for_each_entry_rcu(peer, &entry->peers, list) { 1009 new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC); 1010 if (!new_peer) 1011 break; 1012 1013 new_peer->chan = peer->chan; 1014 INIT_LIST_HEAD(&new_peer->list); 1015 1016 list_add(&new_peer->list, &peers); 1017 } 1018 } 1019 1020 rcu_read_unlock(); 1021 1022 spin_lock(&devices_lock); 1023 list_for_each_entry_safe(peer, tmp_peer, &peers, list) { 1024 l2cap_chan_close(peer->chan, ENOENT); 1025 1026 list_del_rcu(&peer->list); 1027 kfree_rcu(peer, rcu); 1028 } 1029 spin_unlock(&devices_lock); 1030 } 1031 1032 struct set_enable { 1033 struct work_struct work; 1034 bool flag; 1035 }; 1036 1037 static void do_enable_set(struct work_struct *work) 1038 { 1039 struct set_enable *set_enable = container_of(work, 1040 struct set_enable, work); 1041 1042 if (!set_enable->flag || enable_6lowpan != set_enable->flag) 1043 /* Disconnect existing connections if 6lowpan is 1044 * disabled 1045 */ 1046 disconnect_all_peers(); 1047 1048 enable_6lowpan = set_enable->flag; 1049 1050 mutex_lock(&set_lock); 1051 if (listen_chan) { 1052 l2cap_chan_close(listen_chan, 0); 1053 l2cap_chan_put(listen_chan); 1054 } 1055 1056 listen_chan = bt_6lowpan_listen(); 1057 mutex_unlock(&set_lock); 1058 1059 kfree(set_enable); 1060 } 1061 1062 static int lowpan_enable_set(void *data, u64 val) 1063 { 1064 struct set_enable *set_enable; 1065 1066 set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL); 1067 if (!set_enable) 1068 return -ENOMEM; 1069 1070 set_enable->flag = !!val; 1071 INIT_WORK(&set_enable->work, do_enable_set); 1072 1073 schedule_work(&set_enable->work); 1074 1075 return 0; 1076 } 1077 1078 static int lowpan_enable_get(void *data, u64 *val) 1079 { 1080 *val = enable_6lowpan; 1081 return 0; 1082 } 1083 1084 DEFINE_DEBUGFS_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get, 1085 lowpan_enable_set, "%llu\n"); 1086 1087 static ssize_t lowpan_control_write(struct file *fp, 1088 const char __user *user_buffer, 1089 size_t count, 1090 loff_t *position) 1091 { 1092 char buf[32]; 1093 size_t buf_size = min(count, sizeof(buf) - 1); 1094 int ret; 1095 bdaddr_t addr; 1096 u8 addr_type; 1097 struct l2cap_conn *conn = NULL; 1098 1099 if (copy_from_user(buf, user_buffer, buf_size)) 1100 return -EFAULT; 1101 1102 buf[buf_size] = '\0'; 1103 1104 if (memcmp(buf, "connect ", 8) == 0) { 1105 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn); 1106 if (ret == -EINVAL) 1107 return ret; 1108 1109 mutex_lock(&set_lock); 1110 if (listen_chan) { 1111 l2cap_chan_close(listen_chan, 0); 1112 l2cap_chan_put(listen_chan); 1113 listen_chan = NULL; 1114 } 1115 mutex_unlock(&set_lock); 1116 1117 if (conn) { 1118 struct lowpan_peer *peer; 1119 1120 if (!is_bt_6lowpan(conn->hcon)) 1121 return -EINVAL; 1122 1123 peer = lookup_peer(conn); 1124 if (peer) { 1125 BT_DBG("6LoWPAN connection already exists"); 1126 return -EALREADY; 1127 } 1128 1129 BT_DBG("conn %p dst %pMR type %d user %u", conn, 1130 &conn->hcon->dst, conn->hcon->dst_type, 1131 addr_type); 1132 } 1133 1134 ret = bt_6lowpan_connect(&addr, addr_type); 1135 if (ret < 0) 1136 return ret; 1137 1138 return count; 1139 } 1140 1141 if (memcmp(buf, "disconnect ", 11) == 0) { 1142 ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn); 1143 if (ret < 0) 1144 return ret; 1145 1146 ret = bt_6lowpan_disconnect(conn, addr_type); 1147 if (ret < 0) 1148 return ret; 1149 1150 return count; 1151 } 1152 1153 return count; 1154 } 1155 1156 static int lowpan_control_show(struct seq_file *f, void *ptr) 1157 { 1158 struct lowpan_btle_dev *entry; 1159 struct lowpan_peer *peer; 1160 1161 spin_lock(&devices_lock); 1162 1163 list_for_each_entry(entry, &bt_6lowpan_devices, list) { 1164 list_for_each_entry(peer, &entry->peers, list) 1165 seq_printf(f, "%pMR (type %u)\n", 1166 &peer->chan->dst, peer->chan->dst_type); 1167 } 1168 1169 spin_unlock(&devices_lock); 1170 1171 return 0; 1172 } 1173 1174 static int lowpan_control_open(struct inode *inode, struct file *file) 1175 { 1176 return single_open(file, lowpan_control_show, inode->i_private); 1177 } 1178 1179 static const struct file_operations lowpan_control_fops = { 1180 .open = lowpan_control_open, 1181 .read = seq_read, 1182 .write = lowpan_control_write, 1183 .llseek = seq_lseek, 1184 .release = single_release, 1185 }; 1186 1187 static void disconnect_devices(void) 1188 { 1189 struct lowpan_btle_dev *entry, *tmp, *new_dev; 1190 struct list_head devices; 1191 1192 INIT_LIST_HEAD(&devices); 1193 1194 /* We make a separate list of devices because the unregister_netdev() 1195 * will call device_event() which will also want to modify the same 1196 * devices list. 1197 */ 1198 1199 rcu_read_lock(); 1200 1201 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 1202 new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC); 1203 if (!new_dev) 1204 break; 1205 1206 new_dev->netdev = entry->netdev; 1207 INIT_LIST_HEAD(&new_dev->list); 1208 1209 list_add_rcu(&new_dev->list, &devices); 1210 } 1211 1212 rcu_read_unlock(); 1213 1214 list_for_each_entry_safe(entry, tmp, &devices, list) { 1215 ifdown(entry->netdev); 1216 BT_DBG("Unregistering netdev %s %p", 1217 entry->netdev->name, entry->netdev); 1218 lowpan_unregister_netdev(entry->netdev); 1219 kfree(entry); 1220 } 1221 } 1222 1223 static int device_event(struct notifier_block *unused, 1224 unsigned long event, void *ptr) 1225 { 1226 struct net_device *netdev = netdev_notifier_info_to_dev(ptr); 1227 struct lowpan_btle_dev *entry; 1228 1229 if (netdev->type != ARPHRD_6LOWPAN) 1230 return NOTIFY_DONE; 1231 1232 switch (event) { 1233 case NETDEV_UNREGISTER: 1234 spin_lock(&devices_lock); 1235 list_for_each_entry(entry, &bt_6lowpan_devices, list) { 1236 if (entry->netdev == netdev) { 1237 BT_DBG("Unregistered netdev %s %p", 1238 netdev->name, netdev); 1239 list_del(&entry->list); 1240 break; 1241 } 1242 } 1243 spin_unlock(&devices_lock); 1244 break; 1245 } 1246 1247 return NOTIFY_DONE; 1248 } 1249 1250 static struct notifier_block bt_6lowpan_dev_notifier = { 1251 .notifier_call = device_event, 1252 }; 1253 1254 static int __init bt_6lowpan_init(void) 1255 { 1256 lowpan_enable_debugfs = debugfs_create_file_unsafe("6lowpan_enable", 1257 0644, bt_debugfs, 1258 NULL, 1259 &lowpan_enable_fops); 1260 lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644, 1261 bt_debugfs, NULL, 1262 &lowpan_control_fops); 1263 1264 return register_netdevice_notifier(&bt_6lowpan_dev_notifier); 1265 } 1266 1267 static void __exit bt_6lowpan_exit(void) 1268 { 1269 debugfs_remove(lowpan_enable_debugfs); 1270 debugfs_remove(lowpan_control_debugfs); 1271 1272 if (listen_chan) { 1273 l2cap_chan_close(listen_chan, 0); 1274 l2cap_chan_put(listen_chan); 1275 } 1276 1277 disconnect_devices(); 1278 1279 unregister_netdevice_notifier(&bt_6lowpan_dev_notifier); 1280 } 1281 1282 module_init(bt_6lowpan_init); 1283 module_exit(bt_6lowpan_exit); 1284 1285 MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>"); 1286 MODULE_DESCRIPTION("Bluetooth 6LoWPAN"); 1287 MODULE_VERSION(VERSION); 1288 MODULE_LICENSE("GPL"); 1289