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, NULL); 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 struct sk_buff *skb; 830 831 /* Note that we must allocate using GFP_ATOMIC here as 832 * this function is called originally from netdev hard xmit 833 * function in atomic context. 834 */ 835 skb = bt_skb_alloc(hdr_len + len, GFP_ATOMIC); 836 if (!skb) 837 return ERR_PTR(-ENOMEM); 838 return skb; 839 } 840 841 static void chan_suspend_cb(struct l2cap_chan *chan) 842 { 843 struct lowpan_btle_dev *dev; 844 845 BT_DBG("chan %p suspend", chan); 846 847 dev = lookup_dev(chan->conn); 848 if (!dev || !dev->netdev) 849 return; 850 851 netif_stop_queue(dev->netdev); 852 } 853 854 static void chan_resume_cb(struct l2cap_chan *chan) 855 { 856 struct lowpan_btle_dev *dev; 857 858 BT_DBG("chan %p resume", chan); 859 860 dev = lookup_dev(chan->conn); 861 if (!dev || !dev->netdev) 862 return; 863 864 netif_wake_queue(dev->netdev); 865 } 866 867 static long chan_get_sndtimeo_cb(struct l2cap_chan *chan) 868 { 869 return L2CAP_CONN_TIMEOUT; 870 } 871 872 static const struct l2cap_ops bt_6lowpan_chan_ops = { 873 .name = "L2CAP 6LoWPAN channel", 874 .new_connection = chan_new_conn_cb, 875 .recv = chan_recv_cb, 876 .close = chan_close_cb, 877 .state_change = chan_state_change_cb, 878 .ready = chan_ready_cb, 879 .resume = chan_resume_cb, 880 .suspend = chan_suspend_cb, 881 .get_sndtimeo = chan_get_sndtimeo_cb, 882 .alloc_skb = chan_alloc_skb_cb, 883 884 .teardown = l2cap_chan_no_teardown, 885 .defer = l2cap_chan_no_defer, 886 .set_shutdown = l2cap_chan_no_set_shutdown, 887 }; 888 889 static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type) 890 { 891 struct l2cap_chan *chan; 892 int err; 893 894 chan = chan_create(); 895 if (!chan) 896 return -EINVAL; 897 898 chan->ops = &bt_6lowpan_chan_ops; 899 900 err = l2cap_chan_connect(chan, cpu_to_le16(L2CAP_PSM_IPSP), 0, 901 addr, dst_type, L2CAP_CONN_TIMEOUT); 902 903 BT_DBG("chan %p err %d", chan, err); 904 if (err < 0) 905 l2cap_chan_put(chan); 906 907 return err; 908 } 909 910 static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type) 911 { 912 struct lowpan_peer *peer; 913 914 BT_DBG("conn %p dst type %u", conn, dst_type); 915 916 peer = lookup_peer(conn); 917 if (!peer) 918 return -ENOENT; 919 920 BT_DBG("peer %p chan %p", peer, peer->chan); 921 922 l2cap_chan_close(peer->chan, ENOENT); 923 924 return 0; 925 } 926 927 static struct l2cap_chan *bt_6lowpan_listen(void) 928 { 929 bdaddr_t *addr = BDADDR_ANY; 930 struct l2cap_chan *chan; 931 int err; 932 933 if (!enable_6lowpan) 934 return NULL; 935 936 chan = chan_create(); 937 if (!chan) 938 return NULL; 939 940 chan->ops = &bt_6lowpan_chan_ops; 941 chan->state = BT_LISTEN; 942 chan->src_type = BDADDR_LE_PUBLIC; 943 944 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT); 945 946 BT_DBG("chan %p src type %u", chan, chan->src_type); 947 948 err = l2cap_add_psm(chan, addr, cpu_to_le16(L2CAP_PSM_IPSP)); 949 if (err) { 950 l2cap_chan_put(chan); 951 BT_ERR("psm cannot be added err %d", err); 952 return NULL; 953 } 954 955 return chan; 956 } 957 958 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type, 959 struct l2cap_conn **conn) 960 { 961 struct hci_conn *hcon; 962 struct hci_dev *hdev; 963 int n; 964 965 n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu", 966 &addr->b[5], &addr->b[4], &addr->b[3], 967 &addr->b[2], &addr->b[1], &addr->b[0], 968 addr_type); 969 970 if (n < 7) 971 return -EINVAL; 972 973 /* The LE_PUBLIC address type is ignored because of BDADDR_ANY */ 974 hdev = hci_get_route(addr, BDADDR_ANY, BDADDR_LE_PUBLIC); 975 if (!hdev) 976 return -ENOENT; 977 978 hci_dev_lock(hdev); 979 hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type); 980 hci_dev_unlock(hdev); 981 hci_dev_put(hdev); 982 983 if (!hcon) 984 return -ENOENT; 985 986 *conn = (struct l2cap_conn *)hcon->l2cap_data; 987 988 BT_DBG("conn %p dst %pMR type %u", *conn, &hcon->dst, hcon->dst_type); 989 990 return 0; 991 } 992 993 static void disconnect_all_peers(void) 994 { 995 struct lowpan_btle_dev *entry; 996 struct lowpan_peer *peer, *tmp_peer, *new_peer; 997 struct list_head peers; 998 999 INIT_LIST_HEAD(&peers); 1000 1001 /* We make a separate list of peers as the close_cb() will 1002 * modify the device peers list so it is better not to mess 1003 * with the same list at the same time. 1004 */ 1005 1006 rcu_read_lock(); 1007 1008 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 1009 list_for_each_entry_rcu(peer, &entry->peers, list) { 1010 new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC); 1011 if (!new_peer) 1012 break; 1013 1014 new_peer->chan = peer->chan; 1015 INIT_LIST_HEAD(&new_peer->list); 1016 1017 list_add(&new_peer->list, &peers); 1018 } 1019 } 1020 1021 rcu_read_unlock(); 1022 1023 spin_lock(&devices_lock); 1024 list_for_each_entry_safe(peer, tmp_peer, &peers, list) { 1025 l2cap_chan_close(peer->chan, ENOENT); 1026 1027 list_del_rcu(&peer->list); 1028 kfree_rcu(peer, rcu); 1029 } 1030 spin_unlock(&devices_lock); 1031 } 1032 1033 struct set_enable { 1034 struct work_struct work; 1035 bool flag; 1036 }; 1037 1038 static void do_enable_set(struct work_struct *work) 1039 { 1040 struct set_enable *set_enable = container_of(work, 1041 struct set_enable, work); 1042 1043 if (!set_enable->flag || enable_6lowpan != set_enable->flag) 1044 /* Disconnect existing connections if 6lowpan is 1045 * disabled 1046 */ 1047 disconnect_all_peers(); 1048 1049 enable_6lowpan = set_enable->flag; 1050 1051 mutex_lock(&set_lock); 1052 if (listen_chan) { 1053 l2cap_chan_close(listen_chan, 0); 1054 l2cap_chan_put(listen_chan); 1055 } 1056 1057 listen_chan = bt_6lowpan_listen(); 1058 mutex_unlock(&set_lock); 1059 1060 kfree(set_enable); 1061 } 1062 1063 static int lowpan_enable_set(void *data, u64 val) 1064 { 1065 struct set_enable *set_enable; 1066 1067 set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL); 1068 if (!set_enable) 1069 return -ENOMEM; 1070 1071 set_enable->flag = !!val; 1072 INIT_WORK(&set_enable->work, do_enable_set); 1073 1074 schedule_work(&set_enable->work); 1075 1076 return 0; 1077 } 1078 1079 static int lowpan_enable_get(void *data, u64 *val) 1080 { 1081 *val = enable_6lowpan; 1082 return 0; 1083 } 1084 1085 DEFINE_DEBUGFS_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get, 1086 lowpan_enable_set, "%llu\n"); 1087 1088 static ssize_t lowpan_control_write(struct file *fp, 1089 const char __user *user_buffer, 1090 size_t count, 1091 loff_t *position) 1092 { 1093 char buf[32]; 1094 size_t buf_size = min(count, sizeof(buf) - 1); 1095 int ret; 1096 bdaddr_t addr; 1097 u8 addr_type; 1098 struct l2cap_conn *conn = NULL; 1099 1100 if (copy_from_user(buf, user_buffer, buf_size)) 1101 return -EFAULT; 1102 1103 buf[buf_size] = '\0'; 1104 1105 if (memcmp(buf, "connect ", 8) == 0) { 1106 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn); 1107 if (ret == -EINVAL) 1108 return ret; 1109 1110 mutex_lock(&set_lock); 1111 if (listen_chan) { 1112 l2cap_chan_close(listen_chan, 0); 1113 l2cap_chan_put(listen_chan); 1114 listen_chan = NULL; 1115 } 1116 mutex_unlock(&set_lock); 1117 1118 if (conn) { 1119 struct lowpan_peer *peer; 1120 1121 if (!is_bt_6lowpan(conn->hcon)) 1122 return -EINVAL; 1123 1124 peer = lookup_peer(conn); 1125 if (peer) { 1126 BT_DBG("6LoWPAN connection already exists"); 1127 return -EALREADY; 1128 } 1129 1130 BT_DBG("conn %p dst %pMR type %d user %u", conn, 1131 &conn->hcon->dst, conn->hcon->dst_type, 1132 addr_type); 1133 } 1134 1135 ret = bt_6lowpan_connect(&addr, addr_type); 1136 if (ret < 0) 1137 return ret; 1138 1139 return count; 1140 } 1141 1142 if (memcmp(buf, "disconnect ", 11) == 0) { 1143 ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn); 1144 if (ret < 0) 1145 return ret; 1146 1147 ret = bt_6lowpan_disconnect(conn, addr_type); 1148 if (ret < 0) 1149 return ret; 1150 1151 return count; 1152 } 1153 1154 return count; 1155 } 1156 1157 static int lowpan_control_show(struct seq_file *f, void *ptr) 1158 { 1159 struct lowpan_btle_dev *entry; 1160 struct lowpan_peer *peer; 1161 1162 spin_lock(&devices_lock); 1163 1164 list_for_each_entry(entry, &bt_6lowpan_devices, list) { 1165 list_for_each_entry(peer, &entry->peers, list) 1166 seq_printf(f, "%pMR (type %u)\n", 1167 &peer->chan->dst, peer->chan->dst_type); 1168 } 1169 1170 spin_unlock(&devices_lock); 1171 1172 return 0; 1173 } 1174 1175 static int lowpan_control_open(struct inode *inode, struct file *file) 1176 { 1177 return single_open(file, lowpan_control_show, inode->i_private); 1178 } 1179 1180 static const struct file_operations lowpan_control_fops = { 1181 .open = lowpan_control_open, 1182 .read = seq_read, 1183 .write = lowpan_control_write, 1184 .llseek = seq_lseek, 1185 .release = single_release, 1186 }; 1187 1188 static void disconnect_devices(void) 1189 { 1190 struct lowpan_btle_dev *entry, *tmp, *new_dev; 1191 struct list_head devices; 1192 1193 INIT_LIST_HEAD(&devices); 1194 1195 /* We make a separate list of devices because the unregister_netdev() 1196 * will call device_event() which will also want to modify the same 1197 * devices list. 1198 */ 1199 1200 rcu_read_lock(); 1201 1202 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 1203 new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC); 1204 if (!new_dev) 1205 break; 1206 1207 new_dev->netdev = entry->netdev; 1208 INIT_LIST_HEAD(&new_dev->list); 1209 1210 list_add_rcu(&new_dev->list, &devices); 1211 } 1212 1213 rcu_read_unlock(); 1214 1215 list_for_each_entry_safe(entry, tmp, &devices, list) { 1216 ifdown(entry->netdev); 1217 BT_DBG("Unregistering netdev %s %p", 1218 entry->netdev->name, entry->netdev); 1219 lowpan_unregister_netdev(entry->netdev); 1220 kfree(entry); 1221 } 1222 } 1223 1224 static int device_event(struct notifier_block *unused, 1225 unsigned long event, void *ptr) 1226 { 1227 struct net_device *netdev = netdev_notifier_info_to_dev(ptr); 1228 struct lowpan_btle_dev *entry; 1229 1230 if (netdev->type != ARPHRD_6LOWPAN) 1231 return NOTIFY_DONE; 1232 1233 switch (event) { 1234 case NETDEV_UNREGISTER: 1235 spin_lock(&devices_lock); 1236 list_for_each_entry(entry, &bt_6lowpan_devices, list) { 1237 if (entry->netdev == netdev) { 1238 BT_DBG("Unregistered netdev %s %p", 1239 netdev->name, netdev); 1240 list_del(&entry->list); 1241 break; 1242 } 1243 } 1244 spin_unlock(&devices_lock); 1245 break; 1246 } 1247 1248 return NOTIFY_DONE; 1249 } 1250 1251 static struct notifier_block bt_6lowpan_dev_notifier = { 1252 .notifier_call = device_event, 1253 }; 1254 1255 static int __init bt_6lowpan_init(void) 1256 { 1257 lowpan_enable_debugfs = debugfs_create_file_unsafe("6lowpan_enable", 1258 0644, bt_debugfs, 1259 NULL, 1260 &lowpan_enable_fops); 1261 lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644, 1262 bt_debugfs, NULL, 1263 &lowpan_control_fops); 1264 1265 return register_netdevice_notifier(&bt_6lowpan_dev_notifier); 1266 } 1267 1268 static void __exit bt_6lowpan_exit(void) 1269 { 1270 debugfs_remove(lowpan_enable_debugfs); 1271 debugfs_remove(lowpan_control_debugfs); 1272 1273 if (listen_chan) { 1274 l2cap_chan_close(listen_chan, 0); 1275 l2cap_chan_put(listen_chan); 1276 } 1277 1278 disconnect_devices(); 1279 1280 unregister_netdevice_notifier(&bt_6lowpan_dev_notifier); 1281 } 1282 1283 module_init(bt_6lowpan_init); 1284 module_exit(bt_6lowpan_exit); 1285 1286 MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>"); 1287 MODULE_DESCRIPTION("Bluetooth 6LoWPAN"); 1288 MODULE_VERSION(VERSION); 1289 MODULE_LICENSE("GPL"); 1290