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 = (struct 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, WRITE, &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 /* Note that we must allocate using GFP_ATOMIC here as 829 * this function is called originally from netdev hard xmit 830 * function in atomic context. 831 */ 832 return bt_skb_alloc(hdr_len + len, GFP_ATOMIC); 833 } 834 835 static void chan_suspend_cb(struct l2cap_chan *chan) 836 { 837 struct lowpan_btle_dev *dev; 838 839 BT_DBG("chan %p suspend", chan); 840 841 dev = lookup_dev(chan->conn); 842 if (!dev || !dev->netdev) 843 return; 844 845 netif_stop_queue(dev->netdev); 846 } 847 848 static void chan_resume_cb(struct l2cap_chan *chan) 849 { 850 struct lowpan_btle_dev *dev; 851 852 BT_DBG("chan %p resume", chan); 853 854 dev = lookup_dev(chan->conn); 855 if (!dev || !dev->netdev) 856 return; 857 858 netif_wake_queue(dev->netdev); 859 } 860 861 static long chan_get_sndtimeo_cb(struct l2cap_chan *chan) 862 { 863 return L2CAP_CONN_TIMEOUT; 864 } 865 866 static const struct l2cap_ops bt_6lowpan_chan_ops = { 867 .name = "L2CAP 6LoWPAN channel", 868 .new_connection = chan_new_conn_cb, 869 .recv = chan_recv_cb, 870 .close = chan_close_cb, 871 .state_change = chan_state_change_cb, 872 .ready = chan_ready_cb, 873 .resume = chan_resume_cb, 874 .suspend = chan_suspend_cb, 875 .get_sndtimeo = chan_get_sndtimeo_cb, 876 .alloc_skb = chan_alloc_skb_cb, 877 878 .teardown = l2cap_chan_no_teardown, 879 .defer = l2cap_chan_no_defer, 880 .set_shutdown = l2cap_chan_no_set_shutdown, 881 }; 882 883 static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type) 884 { 885 struct l2cap_chan *chan; 886 int err; 887 888 chan = chan_create(); 889 if (!chan) 890 return -EINVAL; 891 892 chan->ops = &bt_6lowpan_chan_ops; 893 894 err = l2cap_chan_connect(chan, cpu_to_le16(L2CAP_PSM_IPSP), 0, 895 addr, dst_type); 896 897 BT_DBG("chan %p err %d", chan, err); 898 if (err < 0) 899 l2cap_chan_put(chan); 900 901 return err; 902 } 903 904 static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type) 905 { 906 struct lowpan_peer *peer; 907 908 BT_DBG("conn %p dst type %u", conn, dst_type); 909 910 peer = lookup_peer(conn); 911 if (!peer) 912 return -ENOENT; 913 914 BT_DBG("peer %p chan %p", peer, peer->chan); 915 916 l2cap_chan_close(peer->chan, ENOENT); 917 918 return 0; 919 } 920 921 static struct l2cap_chan *bt_6lowpan_listen(void) 922 { 923 bdaddr_t *addr = BDADDR_ANY; 924 struct l2cap_chan *chan; 925 int err; 926 927 if (!enable_6lowpan) 928 return NULL; 929 930 chan = chan_create(); 931 if (!chan) 932 return NULL; 933 934 chan->ops = &bt_6lowpan_chan_ops; 935 chan->state = BT_LISTEN; 936 chan->src_type = BDADDR_LE_PUBLIC; 937 938 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT); 939 940 BT_DBG("chan %p src type %u", chan, chan->src_type); 941 942 err = l2cap_add_psm(chan, addr, cpu_to_le16(L2CAP_PSM_IPSP)); 943 if (err) { 944 l2cap_chan_put(chan); 945 BT_ERR("psm cannot be added err %d", err); 946 return NULL; 947 } 948 949 return chan; 950 } 951 952 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type, 953 struct l2cap_conn **conn) 954 { 955 struct hci_conn *hcon; 956 struct hci_dev *hdev; 957 int n; 958 959 n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu", 960 &addr->b[5], &addr->b[4], &addr->b[3], 961 &addr->b[2], &addr->b[1], &addr->b[0], 962 addr_type); 963 964 if (n < 7) 965 return -EINVAL; 966 967 /* The LE_PUBLIC address type is ignored because of BDADDR_ANY */ 968 hdev = hci_get_route(addr, BDADDR_ANY, BDADDR_LE_PUBLIC); 969 if (!hdev) 970 return -ENOENT; 971 972 hci_dev_lock(hdev); 973 hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type); 974 hci_dev_unlock(hdev); 975 976 if (!hcon) 977 return -ENOENT; 978 979 *conn = (struct l2cap_conn *)hcon->l2cap_data; 980 981 BT_DBG("conn %p dst %pMR type %u", *conn, &hcon->dst, hcon->dst_type); 982 983 return 0; 984 } 985 986 static void disconnect_all_peers(void) 987 { 988 struct lowpan_btle_dev *entry; 989 struct lowpan_peer *peer, *tmp_peer, *new_peer; 990 struct list_head peers; 991 992 INIT_LIST_HEAD(&peers); 993 994 /* We make a separate list of peers as the close_cb() will 995 * modify the device peers list so it is better not to mess 996 * with the same list at the same time. 997 */ 998 999 rcu_read_lock(); 1000 1001 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 1002 list_for_each_entry_rcu(peer, &entry->peers, list) { 1003 new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC); 1004 if (!new_peer) 1005 break; 1006 1007 new_peer->chan = peer->chan; 1008 INIT_LIST_HEAD(&new_peer->list); 1009 1010 list_add(&new_peer->list, &peers); 1011 } 1012 } 1013 1014 rcu_read_unlock(); 1015 1016 spin_lock(&devices_lock); 1017 list_for_each_entry_safe(peer, tmp_peer, &peers, list) { 1018 l2cap_chan_close(peer->chan, ENOENT); 1019 1020 list_del_rcu(&peer->list); 1021 kfree_rcu(peer, rcu); 1022 } 1023 spin_unlock(&devices_lock); 1024 } 1025 1026 struct set_enable { 1027 struct work_struct work; 1028 bool flag; 1029 }; 1030 1031 static void do_enable_set(struct work_struct *work) 1032 { 1033 struct set_enable *set_enable = container_of(work, 1034 struct set_enable, work); 1035 1036 if (!set_enable->flag || enable_6lowpan != set_enable->flag) 1037 /* Disconnect existing connections if 6lowpan is 1038 * disabled 1039 */ 1040 disconnect_all_peers(); 1041 1042 enable_6lowpan = set_enable->flag; 1043 1044 mutex_lock(&set_lock); 1045 if (listen_chan) { 1046 l2cap_chan_close(listen_chan, 0); 1047 l2cap_chan_put(listen_chan); 1048 } 1049 1050 listen_chan = bt_6lowpan_listen(); 1051 mutex_unlock(&set_lock); 1052 1053 kfree(set_enable); 1054 } 1055 1056 static int lowpan_enable_set(void *data, u64 val) 1057 { 1058 struct set_enable *set_enable; 1059 1060 set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL); 1061 if (!set_enable) 1062 return -ENOMEM; 1063 1064 set_enable->flag = !!val; 1065 INIT_WORK(&set_enable->work, do_enable_set); 1066 1067 schedule_work(&set_enable->work); 1068 1069 return 0; 1070 } 1071 1072 static int lowpan_enable_get(void *data, u64 *val) 1073 { 1074 *val = enable_6lowpan; 1075 return 0; 1076 } 1077 1078 DEFINE_DEBUGFS_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get, 1079 lowpan_enable_set, "%llu\n"); 1080 1081 static ssize_t lowpan_control_write(struct file *fp, 1082 const char __user *user_buffer, 1083 size_t count, 1084 loff_t *position) 1085 { 1086 char buf[32]; 1087 size_t buf_size = min(count, sizeof(buf) - 1); 1088 int ret; 1089 bdaddr_t addr; 1090 u8 addr_type; 1091 struct l2cap_conn *conn = NULL; 1092 1093 if (copy_from_user(buf, user_buffer, buf_size)) 1094 return -EFAULT; 1095 1096 buf[buf_size] = '\0'; 1097 1098 if (memcmp(buf, "connect ", 8) == 0) { 1099 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn); 1100 if (ret == -EINVAL) 1101 return ret; 1102 1103 mutex_lock(&set_lock); 1104 if (listen_chan) { 1105 l2cap_chan_close(listen_chan, 0); 1106 l2cap_chan_put(listen_chan); 1107 listen_chan = NULL; 1108 } 1109 mutex_unlock(&set_lock); 1110 1111 if (conn) { 1112 struct lowpan_peer *peer; 1113 1114 if (!is_bt_6lowpan(conn->hcon)) 1115 return -EINVAL; 1116 1117 peer = lookup_peer(conn); 1118 if (peer) { 1119 BT_DBG("6LoWPAN connection already exists"); 1120 return -EALREADY; 1121 } 1122 1123 BT_DBG("conn %p dst %pMR type %d user %u", conn, 1124 &conn->hcon->dst, conn->hcon->dst_type, 1125 addr_type); 1126 } 1127 1128 ret = bt_6lowpan_connect(&addr, addr_type); 1129 if (ret < 0) 1130 return ret; 1131 1132 return count; 1133 } 1134 1135 if (memcmp(buf, "disconnect ", 11) == 0) { 1136 ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn); 1137 if (ret < 0) 1138 return ret; 1139 1140 ret = bt_6lowpan_disconnect(conn, addr_type); 1141 if (ret < 0) 1142 return ret; 1143 1144 return count; 1145 } 1146 1147 return count; 1148 } 1149 1150 static int lowpan_control_show(struct seq_file *f, void *ptr) 1151 { 1152 struct lowpan_btle_dev *entry; 1153 struct lowpan_peer *peer; 1154 1155 spin_lock(&devices_lock); 1156 1157 list_for_each_entry(entry, &bt_6lowpan_devices, list) { 1158 list_for_each_entry(peer, &entry->peers, list) 1159 seq_printf(f, "%pMR (type %u)\n", 1160 &peer->chan->dst, peer->chan->dst_type); 1161 } 1162 1163 spin_unlock(&devices_lock); 1164 1165 return 0; 1166 } 1167 1168 static int lowpan_control_open(struct inode *inode, struct file *file) 1169 { 1170 return single_open(file, lowpan_control_show, inode->i_private); 1171 } 1172 1173 static const struct file_operations lowpan_control_fops = { 1174 .open = lowpan_control_open, 1175 .read = seq_read, 1176 .write = lowpan_control_write, 1177 .llseek = seq_lseek, 1178 .release = single_release, 1179 }; 1180 1181 static void disconnect_devices(void) 1182 { 1183 struct lowpan_btle_dev *entry, *tmp, *new_dev; 1184 struct list_head devices; 1185 1186 INIT_LIST_HEAD(&devices); 1187 1188 /* We make a separate list of devices because the unregister_netdev() 1189 * will call device_event() which will also want to modify the same 1190 * devices list. 1191 */ 1192 1193 rcu_read_lock(); 1194 1195 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 1196 new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC); 1197 if (!new_dev) 1198 break; 1199 1200 new_dev->netdev = entry->netdev; 1201 INIT_LIST_HEAD(&new_dev->list); 1202 1203 list_add_rcu(&new_dev->list, &devices); 1204 } 1205 1206 rcu_read_unlock(); 1207 1208 list_for_each_entry_safe(entry, tmp, &devices, list) { 1209 ifdown(entry->netdev); 1210 BT_DBG("Unregistering netdev %s %p", 1211 entry->netdev->name, entry->netdev); 1212 lowpan_unregister_netdev(entry->netdev); 1213 kfree(entry); 1214 } 1215 } 1216 1217 static int device_event(struct notifier_block *unused, 1218 unsigned long event, void *ptr) 1219 { 1220 struct net_device *netdev = netdev_notifier_info_to_dev(ptr); 1221 struct lowpan_btle_dev *entry; 1222 1223 if (netdev->type != ARPHRD_6LOWPAN) 1224 return NOTIFY_DONE; 1225 1226 switch (event) { 1227 case NETDEV_UNREGISTER: 1228 spin_lock(&devices_lock); 1229 list_for_each_entry(entry, &bt_6lowpan_devices, list) { 1230 if (entry->netdev == netdev) { 1231 BT_DBG("Unregistered netdev %s %p", 1232 netdev->name, netdev); 1233 list_del(&entry->list); 1234 break; 1235 } 1236 } 1237 spin_unlock(&devices_lock); 1238 break; 1239 } 1240 1241 return NOTIFY_DONE; 1242 } 1243 1244 static struct notifier_block bt_6lowpan_dev_notifier = { 1245 .notifier_call = device_event, 1246 }; 1247 1248 static int __init bt_6lowpan_init(void) 1249 { 1250 lowpan_enable_debugfs = debugfs_create_file_unsafe("6lowpan_enable", 1251 0644, bt_debugfs, 1252 NULL, 1253 &lowpan_enable_fops); 1254 lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644, 1255 bt_debugfs, NULL, 1256 &lowpan_control_fops); 1257 1258 return register_netdevice_notifier(&bt_6lowpan_dev_notifier); 1259 } 1260 1261 static void __exit bt_6lowpan_exit(void) 1262 { 1263 debugfs_remove(lowpan_enable_debugfs); 1264 debugfs_remove(lowpan_control_debugfs); 1265 1266 if (listen_chan) { 1267 l2cap_chan_close(listen_chan, 0); 1268 l2cap_chan_put(listen_chan); 1269 } 1270 1271 disconnect_devices(); 1272 1273 unregister_netdevice_notifier(&bt_6lowpan_dev_notifier); 1274 } 1275 1276 module_init(bt_6lowpan_init); 1277 module_exit(bt_6lowpan_exit); 1278 1279 MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>"); 1280 MODULE_DESCRIPTION("Bluetooth 6LoWPAN"); 1281 MODULE_VERSION(VERSION); 1282 MODULE_LICENSE("GPL"); 1283