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_ni(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 memset(&peer->peer_addr, 0, sizeof(struct in6_addr)); 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 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((void *)netdev->dev_addr, &chan->src); 676 677 netdev->netdev_ops = &netdev_ops; 678 SET_NETDEV_DEV(netdev, &chan->conn->hcon->hdev->dev); 679 SET_NETDEV_DEVTYPE(netdev, &bt_type); 680 681 *dev = lowpan_btle_dev(netdev); 682 (*dev)->netdev = netdev; 683 (*dev)->hdev = chan->conn->hcon->hdev; 684 INIT_LIST_HEAD(&(*dev)->peers); 685 686 spin_lock(&devices_lock); 687 INIT_LIST_HEAD(&(*dev)->list); 688 list_add_rcu(&(*dev)->list, &bt_6lowpan_devices); 689 spin_unlock(&devices_lock); 690 691 err = lowpan_register_netdev(netdev, LOWPAN_LLTYPE_BTLE); 692 if (err < 0) { 693 BT_INFO("register_netdev failed %d", err); 694 spin_lock(&devices_lock); 695 list_del_rcu(&(*dev)->list); 696 spin_unlock(&devices_lock); 697 free_netdev(netdev); 698 goto out; 699 } 700 701 BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d", 702 netdev->ifindex, &chan->dst, chan->dst_type, 703 &chan->src, chan->src_type); 704 set_bit(__LINK_STATE_PRESENT, &netdev->state); 705 706 return 0; 707 708 out: 709 return err; 710 } 711 712 static inline void chan_ready_cb(struct l2cap_chan *chan) 713 { 714 struct lowpan_btle_dev *dev; 715 bool new_netdev = false; 716 717 dev = lookup_dev(chan->conn); 718 719 BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev); 720 721 if (!dev) { 722 if (setup_netdev(chan, &dev) < 0) { 723 l2cap_chan_del(chan, -ENOENT); 724 return; 725 } 726 new_netdev = true; 727 } 728 729 if (!try_module_get(THIS_MODULE)) 730 return; 731 732 add_peer_chan(chan, dev, new_netdev); 733 ifup(dev->netdev); 734 } 735 736 static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan) 737 { 738 struct l2cap_chan *chan; 739 740 chan = chan_create(); 741 if (!chan) 742 return NULL; 743 744 chan->ops = pchan->ops; 745 746 BT_DBG("chan %p pchan %p", chan, pchan); 747 748 return chan; 749 } 750 751 static void delete_netdev(struct work_struct *work) 752 { 753 struct lowpan_btle_dev *entry = container_of(work, 754 struct lowpan_btle_dev, 755 delete_netdev); 756 757 lowpan_unregister_netdev(entry->netdev); 758 759 /* The entry pointer is deleted by the netdev destructor. */ 760 } 761 762 static void chan_close_cb(struct l2cap_chan *chan) 763 { 764 struct lowpan_btle_dev *entry; 765 struct lowpan_btle_dev *dev = NULL; 766 struct lowpan_peer *peer; 767 int err = -ENOENT; 768 bool last = false, remove = true; 769 770 BT_DBG("chan %p conn %p", chan, chan->conn); 771 772 if (chan->conn && chan->conn->hcon) { 773 if (!is_bt_6lowpan(chan->conn->hcon)) 774 return; 775 776 /* If conn is set, then the netdev is also there and we should 777 * not remove it. 778 */ 779 remove = false; 780 } 781 782 spin_lock(&devices_lock); 783 784 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 785 dev = lowpan_btle_dev(entry->netdev); 786 peer = __peer_lookup_chan(dev, chan); 787 if (peer) { 788 last = peer_del(dev, peer); 789 err = 0; 790 791 BT_DBG("dev %p removing %speer %p", dev, 792 last ? "last " : "1 ", peer); 793 BT_DBG("chan %p orig refcnt %u", chan, 794 kref_read(&chan->kref)); 795 796 l2cap_chan_put(chan); 797 break; 798 } 799 } 800 801 if (!err && last && dev && !atomic_read(&dev->peer_count)) { 802 spin_unlock(&devices_lock); 803 804 cancel_delayed_work_sync(&dev->notify_peers); 805 806 ifdown(dev->netdev); 807 808 if (remove) { 809 INIT_WORK(&entry->delete_netdev, delete_netdev); 810 schedule_work(&entry->delete_netdev); 811 } 812 } else { 813 spin_unlock(&devices_lock); 814 } 815 } 816 817 static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err) 818 { 819 BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn, 820 state_to_string(state), err); 821 } 822 823 static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan, 824 unsigned long hdr_len, 825 unsigned long len, int nb) 826 { 827 /* Note that we must allocate using GFP_ATOMIC here as 828 * this function is called originally from netdev hard xmit 829 * function in atomic context. 830 */ 831 return bt_skb_alloc(hdr_len + len, GFP_ATOMIC); 832 } 833 834 static void chan_suspend_cb(struct l2cap_chan *chan) 835 { 836 struct lowpan_btle_dev *dev; 837 838 BT_DBG("chan %p suspend", chan); 839 840 dev = lookup_dev(chan->conn); 841 if (!dev || !dev->netdev) 842 return; 843 844 netif_stop_queue(dev->netdev); 845 } 846 847 static void chan_resume_cb(struct l2cap_chan *chan) 848 { 849 struct lowpan_btle_dev *dev; 850 851 BT_DBG("chan %p resume", chan); 852 853 dev = lookup_dev(chan->conn); 854 if (!dev || !dev->netdev) 855 return; 856 857 netif_wake_queue(dev->netdev); 858 } 859 860 static long chan_get_sndtimeo_cb(struct l2cap_chan *chan) 861 { 862 return L2CAP_CONN_TIMEOUT; 863 } 864 865 static const struct l2cap_ops bt_6lowpan_chan_ops = { 866 .name = "L2CAP 6LoWPAN channel", 867 .new_connection = chan_new_conn_cb, 868 .recv = chan_recv_cb, 869 .close = chan_close_cb, 870 .state_change = chan_state_change_cb, 871 .ready = chan_ready_cb, 872 .resume = chan_resume_cb, 873 .suspend = chan_suspend_cb, 874 .get_sndtimeo = chan_get_sndtimeo_cb, 875 .alloc_skb = chan_alloc_skb_cb, 876 877 .teardown = l2cap_chan_no_teardown, 878 .defer = l2cap_chan_no_defer, 879 .set_shutdown = l2cap_chan_no_set_shutdown, 880 }; 881 882 static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type) 883 { 884 struct l2cap_chan *chan; 885 int err; 886 887 chan = chan_create(); 888 if (!chan) 889 return -EINVAL; 890 891 chan->ops = &bt_6lowpan_chan_ops; 892 893 err = l2cap_chan_connect(chan, cpu_to_le16(L2CAP_PSM_IPSP), 0, 894 addr, dst_type); 895 896 BT_DBG("chan %p err %d", chan, err); 897 if (err < 0) 898 l2cap_chan_put(chan); 899 900 return err; 901 } 902 903 static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type) 904 { 905 struct lowpan_peer *peer; 906 907 BT_DBG("conn %p dst type %u", conn, dst_type); 908 909 peer = lookup_peer(conn); 910 if (!peer) 911 return -ENOENT; 912 913 BT_DBG("peer %p chan %p", peer, peer->chan); 914 915 l2cap_chan_close(peer->chan, ENOENT); 916 917 return 0; 918 } 919 920 static struct l2cap_chan *bt_6lowpan_listen(void) 921 { 922 bdaddr_t *addr = BDADDR_ANY; 923 struct l2cap_chan *chan; 924 int err; 925 926 if (!enable_6lowpan) 927 return NULL; 928 929 chan = chan_create(); 930 if (!chan) 931 return NULL; 932 933 chan->ops = &bt_6lowpan_chan_ops; 934 chan->state = BT_LISTEN; 935 chan->src_type = BDADDR_LE_PUBLIC; 936 937 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT); 938 939 BT_DBG("chan %p src type %u", chan, chan->src_type); 940 941 err = l2cap_add_psm(chan, addr, cpu_to_le16(L2CAP_PSM_IPSP)); 942 if (err) { 943 l2cap_chan_put(chan); 944 BT_ERR("psm cannot be added err %d", err); 945 return NULL; 946 } 947 948 return chan; 949 } 950 951 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type, 952 struct l2cap_conn **conn) 953 { 954 struct hci_conn *hcon; 955 struct hci_dev *hdev; 956 int n; 957 958 n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu", 959 &addr->b[5], &addr->b[4], &addr->b[3], 960 &addr->b[2], &addr->b[1], &addr->b[0], 961 addr_type); 962 963 if (n < 7) 964 return -EINVAL; 965 966 /* The LE_PUBLIC address type is ignored because of BDADDR_ANY */ 967 hdev = hci_get_route(addr, BDADDR_ANY, BDADDR_LE_PUBLIC); 968 if (!hdev) 969 return -ENOENT; 970 971 hci_dev_lock(hdev); 972 hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type); 973 hci_dev_unlock(hdev); 974 975 if (!hcon) 976 return -ENOENT; 977 978 *conn = (struct l2cap_conn *)hcon->l2cap_data; 979 980 BT_DBG("conn %p dst %pMR type %u", *conn, &hcon->dst, hcon->dst_type); 981 982 return 0; 983 } 984 985 static void disconnect_all_peers(void) 986 { 987 struct lowpan_btle_dev *entry; 988 struct lowpan_peer *peer, *tmp_peer, *new_peer; 989 struct list_head peers; 990 991 INIT_LIST_HEAD(&peers); 992 993 /* We make a separate list of peers as the close_cb() will 994 * modify the device peers list so it is better not to mess 995 * with the same list at the same time. 996 */ 997 998 rcu_read_lock(); 999 1000 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 1001 list_for_each_entry_rcu(peer, &entry->peers, list) { 1002 new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC); 1003 if (!new_peer) 1004 break; 1005 1006 new_peer->chan = peer->chan; 1007 INIT_LIST_HEAD(&new_peer->list); 1008 1009 list_add(&new_peer->list, &peers); 1010 } 1011 } 1012 1013 rcu_read_unlock(); 1014 1015 spin_lock(&devices_lock); 1016 list_for_each_entry_safe(peer, tmp_peer, &peers, list) { 1017 l2cap_chan_close(peer->chan, ENOENT); 1018 1019 list_del_rcu(&peer->list); 1020 kfree_rcu(peer, rcu); 1021 } 1022 spin_unlock(&devices_lock); 1023 } 1024 1025 struct set_enable { 1026 struct work_struct work; 1027 bool flag; 1028 }; 1029 1030 static void do_enable_set(struct work_struct *work) 1031 { 1032 struct set_enable *set_enable = container_of(work, 1033 struct set_enable, work); 1034 1035 if (!set_enable->flag || enable_6lowpan != set_enable->flag) 1036 /* Disconnect existing connections if 6lowpan is 1037 * disabled 1038 */ 1039 disconnect_all_peers(); 1040 1041 enable_6lowpan = set_enable->flag; 1042 1043 mutex_lock(&set_lock); 1044 if (listen_chan) { 1045 l2cap_chan_close(listen_chan, 0); 1046 l2cap_chan_put(listen_chan); 1047 } 1048 1049 listen_chan = bt_6lowpan_listen(); 1050 mutex_unlock(&set_lock); 1051 1052 kfree(set_enable); 1053 } 1054 1055 static int lowpan_enable_set(void *data, u64 val) 1056 { 1057 struct set_enable *set_enable; 1058 1059 set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL); 1060 if (!set_enable) 1061 return -ENOMEM; 1062 1063 set_enable->flag = !!val; 1064 INIT_WORK(&set_enable->work, do_enable_set); 1065 1066 schedule_work(&set_enable->work); 1067 1068 return 0; 1069 } 1070 1071 static int lowpan_enable_get(void *data, u64 *val) 1072 { 1073 *val = enable_6lowpan; 1074 return 0; 1075 } 1076 1077 DEFINE_DEBUGFS_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get, 1078 lowpan_enable_set, "%llu\n"); 1079 1080 static ssize_t lowpan_control_write(struct file *fp, 1081 const char __user *user_buffer, 1082 size_t count, 1083 loff_t *position) 1084 { 1085 char buf[32]; 1086 size_t buf_size = min(count, sizeof(buf) - 1); 1087 int ret; 1088 bdaddr_t addr; 1089 u8 addr_type; 1090 struct l2cap_conn *conn = NULL; 1091 1092 if (copy_from_user(buf, user_buffer, buf_size)) 1093 return -EFAULT; 1094 1095 buf[buf_size] = '\0'; 1096 1097 if (memcmp(buf, "connect ", 8) == 0) { 1098 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn); 1099 if (ret == -EINVAL) 1100 return ret; 1101 1102 mutex_lock(&set_lock); 1103 if (listen_chan) { 1104 l2cap_chan_close(listen_chan, 0); 1105 l2cap_chan_put(listen_chan); 1106 listen_chan = NULL; 1107 } 1108 mutex_unlock(&set_lock); 1109 1110 if (conn) { 1111 struct lowpan_peer *peer; 1112 1113 if (!is_bt_6lowpan(conn->hcon)) 1114 return -EINVAL; 1115 1116 peer = lookup_peer(conn); 1117 if (peer) { 1118 BT_DBG("6LoWPAN connection already exists"); 1119 return -EALREADY; 1120 } 1121 1122 BT_DBG("conn %p dst %pMR type %d user %u", conn, 1123 &conn->hcon->dst, conn->hcon->dst_type, 1124 addr_type); 1125 } 1126 1127 ret = bt_6lowpan_connect(&addr, addr_type); 1128 if (ret < 0) 1129 return ret; 1130 1131 return count; 1132 } 1133 1134 if (memcmp(buf, "disconnect ", 11) == 0) { 1135 ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn); 1136 if (ret < 0) 1137 return ret; 1138 1139 ret = bt_6lowpan_disconnect(conn, addr_type); 1140 if (ret < 0) 1141 return ret; 1142 1143 return count; 1144 } 1145 1146 return count; 1147 } 1148 1149 static int lowpan_control_show(struct seq_file *f, void *ptr) 1150 { 1151 struct lowpan_btle_dev *entry; 1152 struct lowpan_peer *peer; 1153 1154 spin_lock(&devices_lock); 1155 1156 list_for_each_entry(entry, &bt_6lowpan_devices, list) { 1157 list_for_each_entry(peer, &entry->peers, list) 1158 seq_printf(f, "%pMR (type %u)\n", 1159 &peer->chan->dst, peer->chan->dst_type); 1160 } 1161 1162 spin_unlock(&devices_lock); 1163 1164 return 0; 1165 } 1166 1167 static int lowpan_control_open(struct inode *inode, struct file *file) 1168 { 1169 return single_open(file, lowpan_control_show, inode->i_private); 1170 } 1171 1172 static const struct file_operations lowpan_control_fops = { 1173 .open = lowpan_control_open, 1174 .read = seq_read, 1175 .write = lowpan_control_write, 1176 .llseek = seq_lseek, 1177 .release = single_release, 1178 }; 1179 1180 static void disconnect_devices(void) 1181 { 1182 struct lowpan_btle_dev *entry, *tmp, *new_dev; 1183 struct list_head devices; 1184 1185 INIT_LIST_HEAD(&devices); 1186 1187 /* We make a separate list of devices because the unregister_netdev() 1188 * will call device_event() which will also want to modify the same 1189 * devices list. 1190 */ 1191 1192 rcu_read_lock(); 1193 1194 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 1195 new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC); 1196 if (!new_dev) 1197 break; 1198 1199 new_dev->netdev = entry->netdev; 1200 INIT_LIST_HEAD(&new_dev->list); 1201 1202 list_add_rcu(&new_dev->list, &devices); 1203 } 1204 1205 rcu_read_unlock(); 1206 1207 list_for_each_entry_safe(entry, tmp, &devices, list) { 1208 ifdown(entry->netdev); 1209 BT_DBG("Unregistering netdev %s %p", 1210 entry->netdev->name, entry->netdev); 1211 lowpan_unregister_netdev(entry->netdev); 1212 kfree(entry); 1213 } 1214 } 1215 1216 static int device_event(struct notifier_block *unused, 1217 unsigned long event, void *ptr) 1218 { 1219 struct net_device *netdev = netdev_notifier_info_to_dev(ptr); 1220 struct lowpan_btle_dev *entry; 1221 1222 if (netdev->type != ARPHRD_6LOWPAN) 1223 return NOTIFY_DONE; 1224 1225 switch (event) { 1226 case NETDEV_UNREGISTER: 1227 spin_lock(&devices_lock); 1228 list_for_each_entry(entry, &bt_6lowpan_devices, list) { 1229 if (entry->netdev == netdev) { 1230 BT_DBG("Unregistered netdev %s %p", 1231 netdev->name, netdev); 1232 list_del(&entry->list); 1233 break; 1234 } 1235 } 1236 spin_unlock(&devices_lock); 1237 break; 1238 } 1239 1240 return NOTIFY_DONE; 1241 } 1242 1243 static struct notifier_block bt_6lowpan_dev_notifier = { 1244 .notifier_call = device_event, 1245 }; 1246 1247 static int __init bt_6lowpan_init(void) 1248 { 1249 lowpan_enable_debugfs = debugfs_create_file_unsafe("6lowpan_enable", 1250 0644, bt_debugfs, 1251 NULL, 1252 &lowpan_enable_fops); 1253 lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644, 1254 bt_debugfs, NULL, 1255 &lowpan_control_fops); 1256 1257 return register_netdevice_notifier(&bt_6lowpan_dev_notifier); 1258 } 1259 1260 static void __exit bt_6lowpan_exit(void) 1261 { 1262 debugfs_remove(lowpan_enable_debugfs); 1263 debugfs_remove(lowpan_control_debugfs); 1264 1265 if (listen_chan) { 1266 l2cap_chan_close(listen_chan, 0); 1267 l2cap_chan_put(listen_chan); 1268 } 1269 1270 disconnect_devices(); 1271 1272 unregister_netdevice_notifier(&bt_6lowpan_dev_notifier); 1273 } 1274 1275 module_init(bt_6lowpan_init); 1276 module_exit(bt_6lowpan_exit); 1277 1278 MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>"); 1279 MODULE_DESCRIPTION("Bluetooth 6LoWPAN"); 1280 MODULE_VERSION(VERSION); 1281 MODULE_LICENSE("GPL"); 1282