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/netdev_lock.h> 17 #include <net/pkt_sched.h> 18 19 #include <net/bluetooth/bluetooth.h> 20 #include <net/bluetooth/hci_core.h> 21 #include <net/bluetooth/l2cap.h> 22 23 #include <net/6lowpan.h> /* for the compression support */ 24 25 #define VERSION "0.1" 26 27 static struct dentry *lowpan_enable_debugfs; 28 static struct dentry *lowpan_control_debugfs; 29 30 #define IFACE_NAME_TEMPLATE "bt%d" 31 32 struct skb_cb { 33 struct in6_addr addr; 34 struct in6_addr gw; 35 struct l2cap_chan *chan; 36 }; 37 #define lowpan_cb(skb) ((struct skb_cb *)((skb)->cb)) 38 39 /* The devices list contains those devices that we are acting 40 * as a proxy. The BT 6LoWPAN device is a virtual device that 41 * connects to the Bluetooth LE device. The real connection to 42 * BT device is done via l2cap layer. There exists one 43 * virtual device / one BT 6LoWPAN network (=hciX device). 44 * The list contains struct lowpan_dev elements. 45 */ 46 static LIST_HEAD(bt_6lowpan_devices); 47 static DEFINE_SPINLOCK(devices_lock); 48 49 static bool enable_6lowpan; 50 51 /* We are listening incoming connections via this channel 52 */ 53 static struct l2cap_chan *listen_chan; 54 static DEFINE_MUTEX(set_lock); 55 56 struct lowpan_peer { 57 struct list_head list; 58 struct rcu_head rcu; 59 struct l2cap_chan *chan; 60 61 /* peer addresses in various formats */ 62 unsigned char lladdr[ETH_ALEN]; 63 struct in6_addr peer_addr; 64 }; 65 66 struct lowpan_btle_dev { 67 struct list_head list; 68 69 struct hci_dev *hdev; 70 struct net_device *netdev; 71 struct list_head peers; 72 atomic_t peer_count; /* number of items in peers list */ 73 74 struct work_struct delete_netdev; 75 struct delayed_work notify_peers; 76 }; 77 78 static inline struct lowpan_btle_dev * 79 lowpan_btle_dev(const struct net_device *netdev) 80 { 81 return (struct lowpan_btle_dev *)lowpan_dev(netdev)->priv; 82 } 83 84 static inline void peer_add(struct lowpan_btle_dev *dev, 85 struct lowpan_peer *peer) 86 { 87 list_add_rcu(&peer->list, &dev->peers); 88 atomic_inc(&dev->peer_count); 89 } 90 91 static inline bool peer_del(struct lowpan_btle_dev *dev, 92 struct lowpan_peer *peer) 93 { 94 list_del_rcu(&peer->list); 95 kfree_rcu(peer, rcu); 96 97 module_put(THIS_MODULE); 98 99 if (atomic_dec_and_test(&dev->peer_count)) { 100 BT_DBG("last peer"); 101 return true; 102 } 103 104 return false; 105 } 106 107 static inline struct lowpan_peer * 108 __peer_lookup_chan(struct lowpan_btle_dev *dev, struct l2cap_chan *chan) 109 { 110 struct lowpan_peer *peer; 111 112 list_for_each_entry_rcu(peer, &dev->peers, list) { 113 if (peer->chan == chan) 114 return peer; 115 } 116 117 return NULL; 118 } 119 120 static inline struct lowpan_peer * 121 __peer_lookup_conn(struct lowpan_btle_dev *dev, struct l2cap_conn *conn) 122 { 123 struct lowpan_peer *peer; 124 125 list_for_each_entry_rcu(peer, &dev->peers, list) { 126 if (peer->chan->conn == conn) 127 return peer; 128 } 129 130 return NULL; 131 } 132 133 static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_btle_dev *dev, 134 struct in6_addr *daddr, 135 struct sk_buff *skb) 136 { 137 struct rt6_info *rt = dst_rt6_info(skb_dst(skb)); 138 int count = atomic_read(&dev->peer_count); 139 const struct in6_addr *nexthop; 140 struct lowpan_peer *peer; 141 struct neighbour *neigh; 142 143 BT_DBG("peers %d addr %pI6c rt %p", count, daddr, rt); 144 145 if (!rt) { 146 if (ipv6_addr_any(&lowpan_cb(skb)->gw)) { 147 /* There is neither route nor gateway, 148 * probably the destination is a direct peer. 149 */ 150 nexthop = daddr; 151 } else { 152 /* There is a known gateway 153 */ 154 nexthop = &lowpan_cb(skb)->gw; 155 } 156 } else { 157 nexthop = rt6_nexthop(rt, daddr); 158 159 /* We need to remember the address because it is needed 160 * by bt_xmit() when sending the packet. In bt_xmit(), the 161 * destination routing info is not set. 162 */ 163 memcpy(&lowpan_cb(skb)->gw, nexthop, sizeof(struct in6_addr)); 164 } 165 166 BT_DBG("gw %pI6c", nexthop); 167 168 rcu_read_lock(); 169 170 list_for_each_entry_rcu(peer, &dev->peers, list) { 171 BT_DBG("dst addr %pMR dst type %u ip %pI6c", 172 &peer->chan->dst, peer->chan->dst_type, 173 &peer->peer_addr); 174 175 if (!ipv6_addr_cmp(&peer->peer_addr, nexthop)) { 176 rcu_read_unlock(); 177 return peer; 178 } 179 } 180 181 /* use the neighbour cache for matching addresses assigned by SLAAC */ 182 neigh = __ipv6_neigh_lookup(dev->netdev, nexthop); 183 if (neigh) { 184 list_for_each_entry_rcu(peer, &dev->peers, list) { 185 if (!memcmp(neigh->ha, peer->lladdr, ETH_ALEN)) { 186 neigh_release(neigh); 187 rcu_read_unlock(); 188 return peer; 189 } 190 } 191 neigh_release(neigh); 192 } 193 194 rcu_read_unlock(); 195 196 return NULL; 197 } 198 199 static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn) 200 { 201 struct lowpan_btle_dev *entry; 202 struct lowpan_peer *peer = NULL; 203 204 rcu_read_lock(); 205 206 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 207 peer = __peer_lookup_conn(entry, conn); 208 if (peer) 209 break; 210 } 211 212 rcu_read_unlock(); 213 214 return peer; 215 } 216 217 static struct lowpan_btle_dev *lookup_dev(struct l2cap_conn *conn) 218 { 219 struct lowpan_btle_dev *entry; 220 struct lowpan_btle_dev *dev = NULL; 221 222 rcu_read_lock(); 223 224 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 225 if (conn->hcon->hdev == entry->hdev) { 226 dev = entry; 227 break; 228 } 229 } 230 231 rcu_read_unlock(); 232 233 return dev; 234 } 235 236 static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev) 237 { 238 struct sk_buff *skb_cp; 239 240 skb_cp = skb_copy(skb, GFP_ATOMIC); 241 if (!skb_cp) 242 return NET_RX_DROP; 243 244 return netif_rx(skb_cp); 245 } 246 247 static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev, 248 struct lowpan_peer *peer) 249 { 250 const u8 *saddr; 251 252 saddr = peer->lladdr; 253 254 return lowpan_header_decompress(skb, netdev, netdev->dev_addr, saddr); 255 } 256 257 static int recv_pkt(struct sk_buff *skb, struct net_device *dev, 258 struct lowpan_peer *peer) 259 { 260 struct sk_buff *local_skb; 261 int ret; 262 263 if (!netif_running(dev)) 264 goto drop; 265 266 if (dev->type != ARPHRD_6LOWPAN || !skb->len) 267 goto drop; 268 269 skb_reset_network_header(skb); 270 271 skb = skb_share_check(skb, GFP_ATOMIC); 272 if (!skb) 273 goto drop; 274 275 /* check that it's our buffer */ 276 if (lowpan_is_ipv6(*skb_network_header(skb))) { 277 /* Pull off the 1-byte of 6lowpan header. */ 278 skb_pull(skb, 1); 279 280 /* Copy the packet so that the IPv6 header is 281 * properly aligned. 282 */ 283 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1, 284 skb_tailroom(skb), GFP_ATOMIC); 285 if (!local_skb) 286 goto drop; 287 288 local_skb->protocol = htons(ETH_P_IPV6); 289 local_skb->pkt_type = PACKET_HOST; 290 local_skb->dev = dev; 291 292 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr)); 293 294 if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) { 295 kfree_skb(local_skb); 296 goto drop; 297 } 298 299 dev->stats.rx_bytes += skb->len; 300 dev->stats.rx_packets++; 301 302 consume_skb(local_skb); 303 consume_skb(skb); 304 } else if (lowpan_is_iphc(*skb_network_header(skb))) { 305 local_skb = skb_clone(skb, GFP_ATOMIC); 306 if (!local_skb) 307 goto drop; 308 309 local_skb->dev = dev; 310 311 ret = iphc_decompress(local_skb, dev, peer); 312 if (ret < 0) { 313 BT_DBG("iphc_decompress failed: %d", ret); 314 kfree_skb(local_skb); 315 goto drop; 316 } 317 318 local_skb->protocol = htons(ETH_P_IPV6); 319 local_skb->pkt_type = PACKET_HOST; 320 321 if (give_skb_to_upper(local_skb, dev) 322 != NET_RX_SUCCESS) { 323 kfree_skb(local_skb); 324 goto drop; 325 } 326 327 dev->stats.rx_bytes += skb->len; 328 dev->stats.rx_packets++; 329 330 consume_skb(local_skb); 331 consume_skb(skb); 332 } else { 333 BT_DBG("unknown packet type"); 334 goto drop; 335 } 336 337 return NET_RX_SUCCESS; 338 339 drop: 340 dev->stats.rx_dropped++; 341 return NET_RX_DROP; 342 } 343 344 /* Packet from BT LE device */ 345 static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) 346 { 347 struct lowpan_btle_dev *dev; 348 struct lowpan_peer *peer; 349 int err; 350 351 peer = lookup_peer(chan->conn); 352 if (!peer) 353 return -ENOENT; 354 355 dev = lookup_dev(chan->conn); 356 if (!dev || !dev->netdev) 357 return -ENOENT; 358 359 err = recv_pkt(skb, dev->netdev, peer); 360 if (err) { 361 BT_DBG("recv pkt %d", err); 362 err = -EAGAIN; 363 } 364 365 return err; 366 } 367 368 static int setup_header(struct sk_buff *skb, struct net_device *netdev, 369 bdaddr_t *peer_addr, u8 *peer_addr_type) 370 { 371 struct in6_addr ipv6_daddr; 372 struct ipv6hdr *hdr; 373 struct lowpan_btle_dev *dev; 374 struct lowpan_peer *peer; 375 u8 *daddr; 376 int err, status = 0; 377 378 hdr = ipv6_hdr(skb); 379 380 dev = lowpan_btle_dev(netdev); 381 382 memcpy(&ipv6_daddr, &hdr->daddr, sizeof(ipv6_daddr)); 383 384 if (ipv6_addr_is_multicast(&ipv6_daddr)) { 385 lowpan_cb(skb)->chan = NULL; 386 daddr = NULL; 387 } else { 388 BT_DBG("dest IP %pI6c", &ipv6_daddr); 389 390 /* The packet might be sent to 6lowpan interface 391 * because of routing (either via default route 392 * or user set route) so get peer according to 393 * the destination address. 394 */ 395 peer = peer_lookup_dst(dev, &ipv6_daddr, skb); 396 if (!peer) { 397 BT_DBG("no such peer"); 398 return -ENOENT; 399 } 400 401 daddr = peer->lladdr; 402 *peer_addr = peer->chan->dst; 403 *peer_addr_type = peer->chan->dst_type; 404 lowpan_cb(skb)->chan = peer->chan; 405 406 status = 1; 407 } 408 409 lowpan_header_compress(skb, netdev, daddr, dev->netdev->dev_addr); 410 411 err = dev_hard_header(skb, netdev, ETH_P_IPV6, NULL, NULL, 0); 412 if (err < 0) 413 return err; 414 415 return status; 416 } 417 418 static int header_create(struct sk_buff *skb, struct net_device *netdev, 419 unsigned short type, const void *_daddr, 420 const void *_saddr, unsigned int len) 421 { 422 if (type != ETH_P_IPV6) 423 return -EINVAL; 424 425 return 0; 426 } 427 428 /* Packet to BT LE device */ 429 static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb, 430 struct net_device *netdev) 431 { 432 struct msghdr msg; 433 struct kvec iv; 434 int err; 435 436 /* Remember the skb so that we can send EAGAIN to the caller if 437 * we run out of credits. 438 */ 439 chan->data = skb; 440 441 iv.iov_base = skb->data; 442 iv.iov_len = skb->len; 443 444 memset(&msg, 0, sizeof(msg)); 445 iov_iter_kvec(&msg.msg_iter, ITER_SOURCE, &iv, 1, skb->len); 446 447 err = l2cap_chan_send(chan, &msg, skb->len); 448 if (err > 0) { 449 netdev->stats.tx_bytes += err; 450 netdev->stats.tx_packets++; 451 return 0; 452 } 453 454 if (err < 0) 455 netdev->stats.tx_errors++; 456 457 return err; 458 } 459 460 static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev) 461 { 462 struct sk_buff *local_skb; 463 struct lowpan_btle_dev *entry; 464 int err = 0; 465 466 rcu_read_lock(); 467 468 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 469 struct lowpan_peer *pentry; 470 struct lowpan_btle_dev *dev; 471 472 if (entry->netdev != netdev) 473 continue; 474 475 dev = lowpan_btle_dev(entry->netdev); 476 477 list_for_each_entry_rcu(pentry, &dev->peers, list) { 478 int ret; 479 480 local_skb = skb_clone(skb, GFP_ATOMIC); 481 482 BT_DBG("xmit %s to %pMR type %u IP %pI6c chan %p", 483 netdev->name, 484 &pentry->chan->dst, pentry->chan->dst_type, 485 &pentry->peer_addr, pentry->chan); 486 ret = send_pkt(pentry->chan, local_skb, netdev); 487 if (ret < 0) 488 err = ret; 489 490 kfree_skb(local_skb); 491 } 492 } 493 494 rcu_read_unlock(); 495 496 return err; 497 } 498 499 static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev) 500 { 501 int err = 0; 502 bdaddr_t addr; 503 u8 addr_type; 504 505 /* We must take a copy of the skb before we modify/replace the ipv6 506 * header as the header could be used elsewhere 507 */ 508 skb = skb_unshare(skb, GFP_ATOMIC); 509 if (!skb) 510 return NET_XMIT_DROP; 511 512 /* Return values from setup_header() 513 * <0 - error, packet is dropped 514 * 0 - this is a multicast packet 515 * 1 - this is unicast packet 516 */ 517 err = setup_header(skb, netdev, &addr, &addr_type); 518 if (err < 0) { 519 kfree_skb(skb); 520 return NET_XMIT_DROP; 521 } 522 523 if (err) { 524 if (lowpan_cb(skb)->chan) { 525 BT_DBG("xmit %s to %pMR type %u IP %pI6c chan %p", 526 netdev->name, &addr, addr_type, 527 &lowpan_cb(skb)->addr, lowpan_cb(skb)->chan); 528 err = send_pkt(lowpan_cb(skb)->chan, skb, netdev); 529 } else { 530 err = -ENOENT; 531 } 532 } else { 533 /* We need to send the packet to every device behind this 534 * interface. 535 */ 536 err = send_mcast_pkt(skb, netdev); 537 } 538 539 dev_kfree_skb(skb); 540 541 if (err) 542 BT_DBG("ERROR: xmit failed (%d)", err); 543 544 return err < 0 ? NET_XMIT_DROP : err; 545 } 546 547 static int bt_dev_init(struct net_device *dev) 548 { 549 netdev_lockdep_set_classes(dev); 550 551 return 0; 552 } 553 554 static const struct net_device_ops netdev_ops = { 555 .ndo_init = bt_dev_init, 556 .ndo_start_xmit = bt_xmit, 557 }; 558 559 static const struct header_ops header_ops = { 560 .create = header_create, 561 }; 562 563 static void netdev_setup(struct net_device *dev) 564 { 565 dev->hard_header_len = 0; 566 dev->needed_tailroom = 0; 567 dev->flags = IFF_RUNNING | IFF_MULTICAST; 568 dev->watchdog_timeo = 0; 569 dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN; 570 571 dev->netdev_ops = &netdev_ops; 572 dev->header_ops = &header_ops; 573 dev->needs_free_netdev = true; 574 } 575 576 static const struct device_type bt_type = { 577 .name = "bluetooth", 578 }; 579 580 static void ifup(struct net_device *netdev) 581 { 582 int err; 583 584 rtnl_lock(); 585 err = dev_open(netdev, NULL); 586 if (err < 0) 587 BT_INFO("iface %s cannot be opened (%d)", netdev->name, err); 588 rtnl_unlock(); 589 } 590 591 static void ifdown(struct net_device *netdev) 592 { 593 rtnl_lock(); 594 dev_close(netdev); 595 rtnl_unlock(); 596 } 597 598 static void do_notify_peers(struct work_struct *work) 599 { 600 struct lowpan_btle_dev *dev = container_of(work, struct lowpan_btle_dev, 601 notify_peers.work); 602 603 netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */ 604 } 605 606 static bool is_bt_6lowpan(struct hci_conn *hcon) 607 { 608 if (hcon->type != LE_LINK) 609 return false; 610 611 if (!enable_6lowpan) 612 return false; 613 614 return true; 615 } 616 617 static struct l2cap_chan *chan_create(void) 618 { 619 struct l2cap_chan *chan; 620 621 chan = l2cap_chan_create(); 622 if (!chan) 623 return NULL; 624 625 l2cap_chan_set_defaults(chan); 626 627 chan->chan_type = L2CAP_CHAN_CONN_ORIENTED; 628 chan->mode = L2CAP_MODE_LE_FLOWCTL; 629 chan->imtu = 1280; 630 631 return chan; 632 } 633 634 static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan, 635 struct lowpan_btle_dev *dev, 636 bool new_netdev) 637 { 638 struct lowpan_peer *peer; 639 640 peer = kzalloc(sizeof(*peer), GFP_ATOMIC); 641 if (!peer) 642 return NULL; 643 644 peer->chan = chan; 645 646 baswap((void *)peer->lladdr, &chan->dst); 647 648 lowpan_iphc_uncompress_eui48_lladdr(&peer->peer_addr, peer->lladdr); 649 650 spin_lock(&devices_lock); 651 INIT_LIST_HEAD(&peer->list); 652 peer_add(dev, peer); 653 spin_unlock(&devices_lock); 654 655 /* Notifying peers about us needs to be done without locks held */ 656 if (new_netdev) 657 INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers); 658 schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100)); 659 660 return peer->chan; 661 } 662 663 static int setup_netdev(struct l2cap_chan *chan, struct lowpan_btle_dev **dev) 664 { 665 struct net_device *netdev; 666 bdaddr_t addr; 667 int err; 668 669 netdev = alloc_netdev(LOWPAN_PRIV_SIZE(sizeof(struct lowpan_btle_dev)), 670 IFACE_NAME_TEMPLATE, NET_NAME_UNKNOWN, 671 netdev_setup); 672 if (!netdev) 673 return -ENOMEM; 674 675 netdev->addr_assign_type = NET_ADDR_PERM; 676 baswap(&addr, &chan->src); 677 __dev_addr_set(netdev, &addr, sizeof(addr)); 678 679 netdev->netdev_ops = &netdev_ops; 680 SET_NETDEV_DEV(netdev, &chan->conn->hcon->hdev->dev); 681 SET_NETDEV_DEVTYPE(netdev, &bt_type); 682 683 *dev = lowpan_btle_dev(netdev); 684 (*dev)->netdev = netdev; 685 (*dev)->hdev = chan->conn->hcon->hdev; 686 INIT_LIST_HEAD(&(*dev)->peers); 687 688 spin_lock(&devices_lock); 689 INIT_LIST_HEAD(&(*dev)->list); 690 list_add_rcu(&(*dev)->list, &bt_6lowpan_devices); 691 spin_unlock(&devices_lock); 692 693 err = lowpan_register_netdev(netdev, LOWPAN_LLTYPE_BTLE); 694 if (err < 0) { 695 BT_INFO("register_netdev failed %d", err); 696 spin_lock(&devices_lock); 697 list_del_rcu(&(*dev)->list); 698 spin_unlock(&devices_lock); 699 free_netdev(netdev); 700 goto out; 701 } 702 703 BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d", 704 netdev->ifindex, &chan->dst, chan->dst_type, 705 &chan->src, chan->src_type); 706 set_bit(__LINK_STATE_PRESENT, &netdev->state); 707 708 return 0; 709 710 out: 711 return err; 712 } 713 714 static inline void chan_ready_cb(struct l2cap_chan *chan) 715 { 716 struct lowpan_btle_dev *dev; 717 bool new_netdev = false; 718 719 dev = lookup_dev(chan->conn); 720 721 BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev); 722 723 if (!dev) { 724 if (setup_netdev(chan, &dev) < 0) { 725 l2cap_chan_del(chan, -ENOENT); 726 return; 727 } 728 new_netdev = true; 729 } 730 731 if (!try_module_get(THIS_MODULE)) 732 return; 733 734 add_peer_chan(chan, dev, new_netdev); 735 ifup(dev->netdev); 736 } 737 738 static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan) 739 { 740 struct l2cap_chan *chan; 741 742 chan = chan_create(); 743 if (!chan) 744 return NULL; 745 746 chan->ops = pchan->ops; 747 748 BT_DBG("chan %p pchan %p", chan, pchan); 749 750 return chan; 751 } 752 753 static void delete_netdev(struct work_struct *work) 754 { 755 struct lowpan_btle_dev *entry = container_of(work, 756 struct lowpan_btle_dev, 757 delete_netdev); 758 759 lowpan_unregister_netdev(entry->netdev); 760 761 /* The entry pointer is deleted by the netdev destructor. */ 762 } 763 764 static void chan_close_cb(struct l2cap_chan *chan) 765 { 766 struct lowpan_btle_dev *entry; 767 struct lowpan_btle_dev *dev = NULL; 768 struct lowpan_peer *peer; 769 int err = -ENOENT; 770 bool last = false, remove = true; 771 772 BT_DBG("chan %p conn %p", chan, chan->conn); 773 774 if (chan->conn && chan->conn->hcon) { 775 if (!is_bt_6lowpan(chan->conn->hcon)) 776 return; 777 778 /* If conn is set, then the netdev is also there and we should 779 * not remove it. 780 */ 781 remove = false; 782 } 783 784 spin_lock(&devices_lock); 785 786 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 787 dev = lowpan_btle_dev(entry->netdev); 788 peer = __peer_lookup_chan(dev, chan); 789 if (peer) { 790 last = peer_del(dev, peer); 791 err = 0; 792 793 BT_DBG("dev %p removing %speer %p", dev, 794 last ? "last " : "1 ", peer); 795 BT_DBG("chan %p orig refcnt %u", chan, 796 kref_read(&chan->kref)); 797 798 l2cap_chan_put(chan); 799 break; 800 } 801 } 802 803 if (!err && last && dev && !atomic_read(&dev->peer_count)) { 804 spin_unlock(&devices_lock); 805 806 cancel_delayed_work_sync(&dev->notify_peers); 807 808 ifdown(dev->netdev); 809 810 if (remove) { 811 INIT_WORK(&entry->delete_netdev, delete_netdev); 812 schedule_work(&entry->delete_netdev); 813 } 814 } else { 815 spin_unlock(&devices_lock); 816 } 817 } 818 819 static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err) 820 { 821 BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn, 822 state_to_string(state), err); 823 } 824 825 static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan, 826 unsigned long hdr_len, 827 unsigned long len, int nb) 828 { 829 /* Note that we must allocate using GFP_ATOMIC here as 830 * this function is called originally from netdev hard xmit 831 * function in atomic context. 832 */ 833 return bt_skb_alloc(hdr_len + len, GFP_ATOMIC); 834 } 835 836 static void chan_suspend_cb(struct l2cap_chan *chan) 837 { 838 struct lowpan_btle_dev *dev; 839 840 BT_DBG("chan %p suspend", chan); 841 842 dev = lookup_dev(chan->conn); 843 if (!dev || !dev->netdev) 844 return; 845 846 netif_stop_queue(dev->netdev); 847 } 848 849 static void chan_resume_cb(struct l2cap_chan *chan) 850 { 851 struct lowpan_btle_dev *dev; 852 853 BT_DBG("chan %p resume", chan); 854 855 dev = lookup_dev(chan->conn); 856 if (!dev || !dev->netdev) 857 return; 858 859 netif_wake_queue(dev->netdev); 860 } 861 862 static long chan_get_sndtimeo_cb(struct l2cap_chan *chan) 863 { 864 return L2CAP_CONN_TIMEOUT; 865 } 866 867 static const struct l2cap_ops bt_6lowpan_chan_ops = { 868 .name = "L2CAP 6LoWPAN channel", 869 .new_connection = chan_new_conn_cb, 870 .recv = chan_recv_cb, 871 .close = chan_close_cb, 872 .state_change = chan_state_change_cb, 873 .ready = chan_ready_cb, 874 .resume = chan_resume_cb, 875 .suspend = chan_suspend_cb, 876 .get_sndtimeo = chan_get_sndtimeo_cb, 877 .alloc_skb = chan_alloc_skb_cb, 878 879 .teardown = l2cap_chan_no_teardown, 880 .defer = l2cap_chan_no_defer, 881 .set_shutdown = l2cap_chan_no_set_shutdown, 882 }; 883 884 static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type) 885 { 886 struct l2cap_chan *chan; 887 int err; 888 889 chan = chan_create(); 890 if (!chan) 891 return -EINVAL; 892 893 chan->ops = &bt_6lowpan_chan_ops; 894 895 err = l2cap_chan_connect(chan, cpu_to_le16(L2CAP_PSM_IPSP), 0, 896 addr, dst_type, L2CAP_CONN_TIMEOUT); 897 898 BT_DBG("chan %p err %d", chan, err); 899 if (err < 0) 900 l2cap_chan_put(chan); 901 902 return err; 903 } 904 905 static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type) 906 { 907 struct lowpan_peer *peer; 908 909 BT_DBG("conn %p dst type %u", conn, dst_type); 910 911 peer = lookup_peer(conn); 912 if (!peer) 913 return -ENOENT; 914 915 BT_DBG("peer %p chan %p", peer, peer->chan); 916 917 l2cap_chan_close(peer->chan, ENOENT); 918 919 return 0; 920 } 921 922 static struct l2cap_chan *bt_6lowpan_listen(void) 923 { 924 bdaddr_t *addr = BDADDR_ANY; 925 struct l2cap_chan *chan; 926 int err; 927 928 if (!enable_6lowpan) 929 return NULL; 930 931 chan = chan_create(); 932 if (!chan) 933 return NULL; 934 935 chan->ops = &bt_6lowpan_chan_ops; 936 chan->state = BT_LISTEN; 937 chan->src_type = BDADDR_LE_PUBLIC; 938 939 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT); 940 941 BT_DBG("chan %p src type %u", chan, chan->src_type); 942 943 err = l2cap_add_psm(chan, addr, cpu_to_le16(L2CAP_PSM_IPSP)); 944 if (err) { 945 l2cap_chan_put(chan); 946 BT_ERR("psm cannot be added err %d", err); 947 return NULL; 948 } 949 950 return chan; 951 } 952 953 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type, 954 struct l2cap_conn **conn) 955 { 956 struct hci_conn *hcon; 957 struct hci_dev *hdev; 958 int n; 959 960 n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu", 961 &addr->b[5], &addr->b[4], &addr->b[3], 962 &addr->b[2], &addr->b[1], &addr->b[0], 963 addr_type); 964 965 if (n < 7) 966 return -EINVAL; 967 968 /* The LE_PUBLIC address type is ignored because of BDADDR_ANY */ 969 hdev = hci_get_route(addr, BDADDR_ANY, BDADDR_LE_PUBLIC); 970 if (!hdev) 971 return -ENOENT; 972 973 hci_dev_lock(hdev); 974 hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type); 975 hci_dev_unlock(hdev); 976 hci_dev_put(hdev); 977 978 if (!hcon) 979 return -ENOENT; 980 981 *conn = (struct l2cap_conn *)hcon->l2cap_data; 982 983 BT_DBG("conn %p dst %pMR type %u", *conn, &hcon->dst, hcon->dst_type); 984 985 return 0; 986 } 987 988 static void disconnect_all_peers(void) 989 { 990 struct lowpan_btle_dev *entry; 991 struct lowpan_peer *peer, *tmp_peer, *new_peer; 992 struct list_head peers; 993 994 INIT_LIST_HEAD(&peers); 995 996 /* We make a separate list of peers as the close_cb() will 997 * modify the device peers list so it is better not to mess 998 * with the same list at the same time. 999 */ 1000 1001 rcu_read_lock(); 1002 1003 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 1004 list_for_each_entry_rcu(peer, &entry->peers, list) { 1005 new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC); 1006 if (!new_peer) 1007 break; 1008 1009 new_peer->chan = peer->chan; 1010 INIT_LIST_HEAD(&new_peer->list); 1011 1012 list_add(&new_peer->list, &peers); 1013 } 1014 } 1015 1016 rcu_read_unlock(); 1017 1018 spin_lock(&devices_lock); 1019 list_for_each_entry_safe(peer, tmp_peer, &peers, list) { 1020 l2cap_chan_close(peer->chan, ENOENT); 1021 1022 list_del_rcu(&peer->list); 1023 kfree_rcu(peer, rcu); 1024 } 1025 spin_unlock(&devices_lock); 1026 } 1027 1028 struct set_enable { 1029 struct work_struct work; 1030 bool flag; 1031 }; 1032 1033 static void do_enable_set(struct work_struct *work) 1034 { 1035 struct set_enable *set_enable = container_of(work, 1036 struct set_enable, work); 1037 1038 if (!set_enable->flag || enable_6lowpan != set_enable->flag) 1039 /* Disconnect existing connections if 6lowpan is 1040 * disabled 1041 */ 1042 disconnect_all_peers(); 1043 1044 enable_6lowpan = set_enable->flag; 1045 1046 mutex_lock(&set_lock); 1047 if (listen_chan) { 1048 l2cap_chan_close(listen_chan, 0); 1049 l2cap_chan_put(listen_chan); 1050 } 1051 1052 listen_chan = bt_6lowpan_listen(); 1053 mutex_unlock(&set_lock); 1054 1055 kfree(set_enable); 1056 } 1057 1058 static int lowpan_enable_set(void *data, u64 val) 1059 { 1060 struct set_enable *set_enable; 1061 1062 set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL); 1063 if (!set_enable) 1064 return -ENOMEM; 1065 1066 set_enable->flag = !!val; 1067 INIT_WORK(&set_enable->work, do_enable_set); 1068 1069 schedule_work(&set_enable->work); 1070 1071 return 0; 1072 } 1073 1074 static int lowpan_enable_get(void *data, u64 *val) 1075 { 1076 *val = enable_6lowpan; 1077 return 0; 1078 } 1079 1080 DEFINE_DEBUGFS_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get, 1081 lowpan_enable_set, "%llu\n"); 1082 1083 static ssize_t lowpan_control_write(struct file *fp, 1084 const char __user *user_buffer, 1085 size_t count, 1086 loff_t *position) 1087 { 1088 char buf[32]; 1089 size_t buf_size = min(count, sizeof(buf) - 1); 1090 int ret; 1091 bdaddr_t addr; 1092 u8 addr_type; 1093 struct l2cap_conn *conn = NULL; 1094 1095 if (copy_from_user(buf, user_buffer, buf_size)) 1096 return -EFAULT; 1097 1098 buf[buf_size] = '\0'; 1099 1100 if (memcmp(buf, "connect ", 8) == 0) { 1101 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn); 1102 if (ret == -EINVAL) 1103 return ret; 1104 1105 mutex_lock(&set_lock); 1106 if (listen_chan) { 1107 l2cap_chan_close(listen_chan, 0); 1108 l2cap_chan_put(listen_chan); 1109 listen_chan = NULL; 1110 } 1111 mutex_unlock(&set_lock); 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 %u", 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_btle_dev *entry; 1155 struct lowpan_peer *peer; 1156 1157 spin_lock(&devices_lock); 1158 1159 list_for_each_entry(entry, &bt_6lowpan_devices, list) { 1160 list_for_each_entry(peer, &entry->peers, list) 1161 seq_printf(f, "%pMR (type %u)\n", 1162 &peer->chan->dst, peer->chan->dst_type); 1163 } 1164 1165 spin_unlock(&devices_lock); 1166 1167 return 0; 1168 } 1169 1170 static int lowpan_control_open(struct inode *inode, struct file *file) 1171 { 1172 return single_open(file, lowpan_control_show, inode->i_private); 1173 } 1174 1175 static const struct file_operations lowpan_control_fops = { 1176 .open = lowpan_control_open, 1177 .read = seq_read, 1178 .write = lowpan_control_write, 1179 .llseek = seq_lseek, 1180 .release = single_release, 1181 }; 1182 1183 static void disconnect_devices(void) 1184 { 1185 struct lowpan_btle_dev *entry, *tmp, *new_dev; 1186 struct list_head devices; 1187 1188 INIT_LIST_HEAD(&devices); 1189 1190 /* We make a separate list of devices because the unregister_netdev() 1191 * will call device_event() which will also want to modify the same 1192 * devices list. 1193 */ 1194 1195 rcu_read_lock(); 1196 1197 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 1198 new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC); 1199 if (!new_dev) 1200 break; 1201 1202 new_dev->netdev = entry->netdev; 1203 INIT_LIST_HEAD(&new_dev->list); 1204 1205 list_add_rcu(&new_dev->list, &devices); 1206 } 1207 1208 rcu_read_unlock(); 1209 1210 list_for_each_entry_safe(entry, tmp, &devices, list) { 1211 ifdown(entry->netdev); 1212 BT_DBG("Unregistering netdev %s %p", 1213 entry->netdev->name, entry->netdev); 1214 lowpan_unregister_netdev(entry->netdev); 1215 kfree(entry); 1216 } 1217 } 1218 1219 static int device_event(struct notifier_block *unused, 1220 unsigned long event, void *ptr) 1221 { 1222 struct net_device *netdev = netdev_notifier_info_to_dev(ptr); 1223 struct lowpan_btle_dev *entry; 1224 1225 if (netdev->type != ARPHRD_6LOWPAN) 1226 return NOTIFY_DONE; 1227 1228 switch (event) { 1229 case NETDEV_UNREGISTER: 1230 spin_lock(&devices_lock); 1231 list_for_each_entry(entry, &bt_6lowpan_devices, list) { 1232 if (entry->netdev == netdev) { 1233 BT_DBG("Unregistered netdev %s %p", 1234 netdev->name, netdev); 1235 list_del(&entry->list); 1236 break; 1237 } 1238 } 1239 spin_unlock(&devices_lock); 1240 break; 1241 } 1242 1243 return NOTIFY_DONE; 1244 } 1245 1246 static struct notifier_block bt_6lowpan_dev_notifier = { 1247 .notifier_call = device_event, 1248 }; 1249 1250 static int __init bt_6lowpan_init(void) 1251 { 1252 lowpan_enable_debugfs = debugfs_create_file_unsafe("6lowpan_enable", 1253 0644, bt_debugfs, 1254 NULL, 1255 &lowpan_enable_fops); 1256 lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644, 1257 bt_debugfs, NULL, 1258 &lowpan_control_fops); 1259 1260 return register_netdevice_notifier(&bt_6lowpan_dev_notifier); 1261 } 1262 1263 static void __exit bt_6lowpan_exit(void) 1264 { 1265 debugfs_remove(lowpan_enable_debugfs); 1266 debugfs_remove(lowpan_control_debugfs); 1267 1268 if (listen_chan) { 1269 l2cap_chan_close(listen_chan, 0); 1270 l2cap_chan_put(listen_chan); 1271 } 1272 1273 disconnect_devices(); 1274 1275 unregister_netdevice_notifier(&bt_6lowpan_dev_notifier); 1276 } 1277 1278 module_init(bt_6lowpan_init); 1279 module_exit(bt_6lowpan_exit); 1280 1281 MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>"); 1282 MODULE_DESCRIPTION("Bluetooth 6LoWPAN"); 1283 MODULE_VERSION(VERSION); 1284 MODULE_LICENSE("GPL"); 1285