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 54 struct lowpan_peer { 55 struct list_head list; 56 struct rcu_head rcu; 57 struct l2cap_chan *chan; 58 59 /* peer addresses in various formats */ 60 unsigned char lladdr[ETH_ALEN]; 61 struct in6_addr peer_addr; 62 }; 63 64 struct lowpan_btle_dev { 65 struct list_head list; 66 67 struct hci_dev *hdev; 68 struct net_device *netdev; 69 struct list_head peers; 70 atomic_t peer_count; /* number of items in peers list */ 71 72 struct work_struct delete_netdev; 73 struct delayed_work notify_peers; 74 }; 75 76 static inline struct lowpan_btle_dev * 77 lowpan_btle_dev(const struct net_device *netdev) 78 { 79 return (struct lowpan_btle_dev *)lowpan_dev(netdev)->priv; 80 } 81 82 static inline void peer_add(struct lowpan_btle_dev *dev, 83 struct lowpan_peer *peer) 84 { 85 list_add_rcu(&peer->list, &dev->peers); 86 atomic_inc(&dev->peer_count); 87 } 88 89 static inline bool peer_del(struct lowpan_btle_dev *dev, 90 struct lowpan_peer *peer) 91 { 92 list_del_rcu(&peer->list); 93 kfree_rcu(peer, rcu); 94 95 module_put(THIS_MODULE); 96 97 if (atomic_dec_and_test(&dev->peer_count)) { 98 BT_DBG("last peer"); 99 return true; 100 } 101 102 return false; 103 } 104 105 static inline struct lowpan_peer *peer_lookup_ba(struct lowpan_btle_dev *dev, 106 bdaddr_t *ba, __u8 type) 107 { 108 struct lowpan_peer *peer; 109 110 BT_DBG("peers %d addr %pMR type %d", atomic_read(&dev->peer_count), 111 ba, type); 112 113 rcu_read_lock(); 114 115 list_for_each_entry_rcu(peer, &dev->peers, list) { 116 BT_DBG("dst addr %pMR dst type %d", 117 &peer->chan->dst, peer->chan->dst_type); 118 119 if (bacmp(&peer->chan->dst, ba)) 120 continue; 121 122 if (type == peer->chan->dst_type) { 123 rcu_read_unlock(); 124 return peer; 125 } 126 } 127 128 rcu_read_unlock(); 129 130 return NULL; 131 } 132 133 static inline struct lowpan_peer * 134 __peer_lookup_chan(struct lowpan_btle_dev *dev, struct l2cap_chan *chan) 135 { 136 struct lowpan_peer *peer; 137 138 list_for_each_entry_rcu(peer, &dev->peers, list) { 139 if (peer->chan == chan) 140 return peer; 141 } 142 143 return NULL; 144 } 145 146 static inline struct lowpan_peer * 147 __peer_lookup_conn(struct lowpan_btle_dev *dev, struct l2cap_conn *conn) 148 { 149 struct lowpan_peer *peer; 150 151 list_for_each_entry_rcu(peer, &dev->peers, list) { 152 if (peer->chan->conn == conn) 153 return peer; 154 } 155 156 return NULL; 157 } 158 159 static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_btle_dev *dev, 160 struct in6_addr *daddr, 161 struct sk_buff *skb) 162 { 163 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb); 164 int count = atomic_read(&dev->peer_count); 165 const struct in6_addr *nexthop; 166 struct lowpan_peer *peer; 167 struct neighbour *neigh; 168 169 BT_DBG("peers %d addr %pI6c rt %p", count, daddr, rt); 170 171 if (!rt) { 172 if (ipv6_addr_any(&lowpan_cb(skb)->gw)) { 173 /* There is neither route nor gateway, 174 * probably the destination is a direct peer. 175 */ 176 nexthop = daddr; 177 } else { 178 /* There is a known gateway 179 */ 180 nexthop = &lowpan_cb(skb)->gw; 181 } 182 } else { 183 nexthop = rt6_nexthop(rt, daddr); 184 185 /* We need to remember the address because it is needed 186 * by bt_xmit() when sending the packet. In bt_xmit(), the 187 * destination routing info is not set. 188 */ 189 memcpy(&lowpan_cb(skb)->gw, nexthop, sizeof(struct in6_addr)); 190 } 191 192 BT_DBG("gw %pI6c", nexthop); 193 194 rcu_read_lock(); 195 196 list_for_each_entry_rcu(peer, &dev->peers, list) { 197 BT_DBG("dst addr %pMR dst type %d ip %pI6c", 198 &peer->chan->dst, peer->chan->dst_type, 199 &peer->peer_addr); 200 201 if (!ipv6_addr_cmp(&peer->peer_addr, nexthop)) { 202 rcu_read_unlock(); 203 return peer; 204 } 205 } 206 207 /* use the neighbour cache for matching addresses assigned by SLAAC 208 */ 209 neigh = __ipv6_neigh_lookup(dev->netdev, nexthop); 210 if (neigh) { 211 list_for_each_entry_rcu(peer, &dev->peers, list) { 212 if (!memcmp(neigh->ha, peer->lladdr, ETH_ALEN)) { 213 neigh_release(neigh); 214 rcu_read_unlock(); 215 return peer; 216 } 217 } 218 neigh_release(neigh); 219 } 220 221 rcu_read_unlock(); 222 223 return NULL; 224 } 225 226 static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn) 227 { 228 struct lowpan_btle_dev *entry; 229 struct lowpan_peer *peer = NULL; 230 231 rcu_read_lock(); 232 233 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 234 peer = __peer_lookup_conn(entry, conn); 235 if (peer) 236 break; 237 } 238 239 rcu_read_unlock(); 240 241 return peer; 242 } 243 244 static struct lowpan_btle_dev *lookup_dev(struct l2cap_conn *conn) 245 { 246 struct lowpan_btle_dev *entry; 247 struct lowpan_btle_dev *dev = NULL; 248 249 rcu_read_lock(); 250 251 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 252 if (conn->hcon->hdev == entry->hdev) { 253 dev = entry; 254 break; 255 } 256 } 257 258 rcu_read_unlock(); 259 260 return dev; 261 } 262 263 static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev) 264 { 265 struct sk_buff *skb_cp; 266 267 skb_cp = skb_copy(skb, GFP_ATOMIC); 268 if (!skb_cp) 269 return NET_RX_DROP; 270 271 return netif_rx_ni(skb_cp); 272 } 273 274 static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev, 275 struct lowpan_peer *peer) 276 { 277 const u8 *saddr; 278 279 saddr = peer->lladdr; 280 281 return lowpan_header_decompress(skb, netdev, netdev->dev_addr, saddr); 282 } 283 284 static int recv_pkt(struct sk_buff *skb, struct net_device *dev, 285 struct lowpan_peer *peer) 286 { 287 struct sk_buff *local_skb; 288 int ret; 289 290 if (!netif_running(dev)) 291 goto drop; 292 293 if (dev->type != ARPHRD_6LOWPAN || !skb->len) 294 goto drop; 295 296 skb_reset_network_header(skb); 297 298 skb = skb_share_check(skb, GFP_ATOMIC); 299 if (!skb) 300 goto drop; 301 302 /* check that it's our buffer */ 303 if (lowpan_is_ipv6(*skb_network_header(skb))) { 304 /* Pull off the 1-byte of 6lowpan header. */ 305 skb_pull(skb, 1); 306 307 /* Copy the packet so that the IPv6 header is 308 * properly aligned. 309 */ 310 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1, 311 skb_tailroom(skb), GFP_ATOMIC); 312 if (!local_skb) 313 goto drop; 314 315 local_skb->protocol = htons(ETH_P_IPV6); 316 local_skb->pkt_type = PACKET_HOST; 317 local_skb->dev = dev; 318 319 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr)); 320 321 if (give_skb_to_upper(local_skb, dev) != 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 if (lowpan_is_iphc(*skb_network_header(skb))) { 332 local_skb = skb_clone(skb, GFP_ATOMIC); 333 if (!local_skb) 334 goto drop; 335 336 local_skb->dev = dev; 337 338 ret = iphc_decompress(local_skb, dev, peer); 339 if (ret < 0) { 340 BT_DBG("iphc_decompress failed: %d", ret); 341 kfree_skb(local_skb); 342 goto drop; 343 } 344 345 local_skb->protocol = htons(ETH_P_IPV6); 346 local_skb->pkt_type = PACKET_HOST; 347 348 if (give_skb_to_upper(local_skb, dev) 349 != NET_RX_SUCCESS) { 350 kfree_skb(local_skb); 351 goto drop; 352 } 353 354 dev->stats.rx_bytes += skb->len; 355 dev->stats.rx_packets++; 356 357 consume_skb(local_skb); 358 consume_skb(skb); 359 } else { 360 BT_DBG("unknown packet type"); 361 goto drop; 362 } 363 364 return NET_RX_SUCCESS; 365 366 drop: 367 dev->stats.rx_dropped++; 368 return NET_RX_DROP; 369 } 370 371 /* Packet from BT LE device */ 372 static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) 373 { 374 struct lowpan_btle_dev *dev; 375 struct lowpan_peer *peer; 376 int err; 377 378 peer = lookup_peer(chan->conn); 379 if (!peer) 380 return -ENOENT; 381 382 dev = lookup_dev(chan->conn); 383 if (!dev || !dev->netdev) 384 return -ENOENT; 385 386 err = recv_pkt(skb, dev->netdev, peer); 387 if (err) { 388 BT_DBG("recv pkt %d", err); 389 err = -EAGAIN; 390 } 391 392 return err; 393 } 394 395 static int setup_header(struct sk_buff *skb, struct net_device *netdev, 396 bdaddr_t *peer_addr, u8 *peer_addr_type) 397 { 398 struct in6_addr ipv6_daddr; 399 struct ipv6hdr *hdr; 400 struct lowpan_btle_dev *dev; 401 struct lowpan_peer *peer; 402 u8 *daddr; 403 int err, status = 0; 404 405 hdr = ipv6_hdr(skb); 406 407 dev = lowpan_btle_dev(netdev); 408 409 memcpy(&ipv6_daddr, &hdr->daddr, sizeof(ipv6_daddr)); 410 411 if (ipv6_addr_is_multicast(&ipv6_daddr)) { 412 lowpan_cb(skb)->chan = NULL; 413 daddr = NULL; 414 } else { 415 BT_DBG("dest IP %pI6c", &ipv6_daddr); 416 417 /* The packet might be sent to 6lowpan interface 418 * because of routing (either via default route 419 * or user set route) so get peer according to 420 * the destination address. 421 */ 422 peer = peer_lookup_dst(dev, &ipv6_daddr, skb); 423 if (!peer) { 424 BT_DBG("no such peer"); 425 return -ENOENT; 426 } 427 428 daddr = peer->lladdr; 429 *peer_addr = peer->chan->dst; 430 *peer_addr_type = peer->chan->dst_type; 431 lowpan_cb(skb)->chan = peer->chan; 432 433 status = 1; 434 } 435 436 lowpan_header_compress(skb, netdev, daddr, dev->netdev->dev_addr); 437 438 err = dev_hard_header(skb, netdev, ETH_P_IPV6, NULL, NULL, 0); 439 if (err < 0) 440 return err; 441 442 return status; 443 } 444 445 static int header_create(struct sk_buff *skb, struct net_device *netdev, 446 unsigned short type, const void *_daddr, 447 const void *_saddr, unsigned int len) 448 { 449 if (type != ETH_P_IPV6) 450 return -EINVAL; 451 452 return 0; 453 } 454 455 /* Packet to BT LE device */ 456 static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb, 457 struct net_device *netdev) 458 { 459 struct msghdr msg; 460 struct kvec iv; 461 int err; 462 463 /* Remember the skb so that we can send EAGAIN to the caller if 464 * we run out of credits. 465 */ 466 chan->data = skb; 467 468 iv.iov_base = skb->data; 469 iv.iov_len = skb->len; 470 471 memset(&msg, 0, sizeof(msg)); 472 iov_iter_kvec(&msg.msg_iter, WRITE, &iv, 1, skb->len); 473 474 err = l2cap_chan_send(chan, &msg, skb->len); 475 if (err > 0) { 476 netdev->stats.tx_bytes += err; 477 netdev->stats.tx_packets++; 478 return 0; 479 } 480 481 if (err < 0) 482 netdev->stats.tx_errors++; 483 484 return err; 485 } 486 487 static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev) 488 { 489 struct sk_buff *local_skb; 490 struct lowpan_btle_dev *entry; 491 int err = 0; 492 493 rcu_read_lock(); 494 495 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 496 struct lowpan_peer *pentry; 497 struct lowpan_btle_dev *dev; 498 499 if (entry->netdev != netdev) 500 continue; 501 502 dev = lowpan_btle_dev(entry->netdev); 503 504 list_for_each_entry_rcu(pentry, &dev->peers, list) { 505 int ret; 506 507 local_skb = skb_clone(skb, GFP_ATOMIC); 508 509 BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p", 510 netdev->name, 511 &pentry->chan->dst, pentry->chan->dst_type, 512 &pentry->peer_addr, pentry->chan); 513 ret = send_pkt(pentry->chan, local_skb, netdev); 514 if (ret < 0) 515 err = ret; 516 517 kfree_skb(local_skb); 518 } 519 } 520 521 rcu_read_unlock(); 522 523 return err; 524 } 525 526 static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev) 527 { 528 int err = 0; 529 bdaddr_t addr; 530 u8 addr_type; 531 532 /* We must take a copy of the skb before we modify/replace the ipv6 533 * header as the header could be used elsewhere 534 */ 535 skb = skb_unshare(skb, GFP_ATOMIC); 536 if (!skb) 537 return NET_XMIT_DROP; 538 539 /* Return values from setup_header() 540 * <0 - error, packet is dropped 541 * 0 - this is a multicast packet 542 * 1 - this is unicast packet 543 */ 544 err = setup_header(skb, netdev, &addr, &addr_type); 545 if (err < 0) { 546 kfree_skb(skb); 547 return NET_XMIT_DROP; 548 } 549 550 if (err) { 551 if (lowpan_cb(skb)->chan) { 552 BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p", 553 netdev->name, &addr, addr_type, 554 &lowpan_cb(skb)->addr, lowpan_cb(skb)->chan); 555 err = send_pkt(lowpan_cb(skb)->chan, skb, netdev); 556 } else { 557 err = -ENOENT; 558 } 559 } else { 560 /* We need to send the packet to every device behind this 561 * interface. 562 */ 563 err = send_mcast_pkt(skb, netdev); 564 } 565 566 dev_kfree_skb(skb); 567 568 if (err) 569 BT_DBG("ERROR: xmit failed (%d)", err); 570 571 return err < 0 ? NET_XMIT_DROP : err; 572 } 573 574 static int bt_dev_init(struct net_device *dev) 575 { 576 netdev_lockdep_set_classes(dev); 577 578 return 0; 579 } 580 581 static const struct net_device_ops netdev_ops = { 582 .ndo_init = bt_dev_init, 583 .ndo_start_xmit = bt_xmit, 584 }; 585 586 static struct header_ops header_ops = { 587 .create = header_create, 588 }; 589 590 static void netdev_setup(struct net_device *dev) 591 { 592 dev->hard_header_len = 0; 593 dev->needed_tailroom = 0; 594 dev->flags = IFF_RUNNING | IFF_MULTICAST; 595 dev->watchdog_timeo = 0; 596 dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN; 597 598 dev->netdev_ops = &netdev_ops; 599 dev->header_ops = &header_ops; 600 dev->needs_free_netdev = true; 601 } 602 603 static struct device_type bt_type = { 604 .name = "bluetooth", 605 }; 606 607 static void ifup(struct net_device *netdev) 608 { 609 int err; 610 611 rtnl_lock(); 612 err = dev_open(netdev, NULL); 613 if (err < 0) 614 BT_INFO("iface %s cannot be opened (%d)", netdev->name, err); 615 rtnl_unlock(); 616 } 617 618 static void ifdown(struct net_device *netdev) 619 { 620 rtnl_lock(); 621 dev_close(netdev); 622 rtnl_unlock(); 623 } 624 625 static void do_notify_peers(struct work_struct *work) 626 { 627 struct lowpan_btle_dev *dev = container_of(work, struct lowpan_btle_dev, 628 notify_peers.work); 629 630 netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */ 631 } 632 633 static bool is_bt_6lowpan(struct hci_conn *hcon) 634 { 635 if (hcon->type != LE_LINK) 636 return false; 637 638 if (!enable_6lowpan) 639 return false; 640 641 return true; 642 } 643 644 static struct l2cap_chan *chan_create(void) 645 { 646 struct l2cap_chan *chan; 647 648 chan = l2cap_chan_create(); 649 if (!chan) 650 return NULL; 651 652 l2cap_chan_set_defaults(chan); 653 654 chan->chan_type = L2CAP_CHAN_CONN_ORIENTED; 655 chan->mode = L2CAP_MODE_LE_FLOWCTL; 656 chan->imtu = 1280; 657 658 return chan; 659 } 660 661 static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan, 662 struct lowpan_btle_dev *dev, 663 bool new_netdev) 664 { 665 struct lowpan_peer *peer; 666 667 peer = kzalloc(sizeof(*peer), GFP_ATOMIC); 668 if (!peer) 669 return NULL; 670 671 peer->chan = chan; 672 memset(&peer->peer_addr, 0, sizeof(struct in6_addr)); 673 674 baswap((void *)peer->lladdr, &chan->dst); 675 676 lowpan_iphc_uncompress_eui48_lladdr(&peer->peer_addr, peer->lladdr); 677 678 spin_lock(&devices_lock); 679 INIT_LIST_HEAD(&peer->list); 680 peer_add(dev, peer); 681 spin_unlock(&devices_lock); 682 683 /* Notifying peers about us needs to be done without locks held */ 684 if (new_netdev) 685 INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers); 686 schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100)); 687 688 return peer->chan; 689 } 690 691 static int setup_netdev(struct l2cap_chan *chan, struct lowpan_btle_dev **dev) 692 { 693 struct net_device *netdev; 694 int err = 0; 695 696 netdev = alloc_netdev(LOWPAN_PRIV_SIZE(sizeof(struct lowpan_btle_dev)), 697 IFACE_NAME_TEMPLATE, NET_NAME_UNKNOWN, 698 netdev_setup); 699 if (!netdev) 700 return -ENOMEM; 701 702 netdev->addr_assign_type = NET_ADDR_PERM; 703 baswap((void *)netdev->dev_addr, &chan->src); 704 705 netdev->netdev_ops = &netdev_ops; 706 SET_NETDEV_DEV(netdev, &chan->conn->hcon->hdev->dev); 707 SET_NETDEV_DEVTYPE(netdev, &bt_type); 708 709 *dev = lowpan_btle_dev(netdev); 710 (*dev)->netdev = netdev; 711 (*dev)->hdev = chan->conn->hcon->hdev; 712 INIT_LIST_HEAD(&(*dev)->peers); 713 714 spin_lock(&devices_lock); 715 INIT_LIST_HEAD(&(*dev)->list); 716 list_add_rcu(&(*dev)->list, &bt_6lowpan_devices); 717 spin_unlock(&devices_lock); 718 719 err = lowpan_register_netdev(netdev, LOWPAN_LLTYPE_BTLE); 720 if (err < 0) { 721 BT_INFO("register_netdev failed %d", err); 722 spin_lock(&devices_lock); 723 list_del_rcu(&(*dev)->list); 724 spin_unlock(&devices_lock); 725 free_netdev(netdev); 726 goto out; 727 } 728 729 BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d", 730 netdev->ifindex, &chan->dst, chan->dst_type, 731 &chan->src, chan->src_type); 732 set_bit(__LINK_STATE_PRESENT, &netdev->state); 733 734 return 0; 735 736 out: 737 return err; 738 } 739 740 static inline void chan_ready_cb(struct l2cap_chan *chan) 741 { 742 struct lowpan_btle_dev *dev; 743 bool new_netdev = false; 744 745 dev = lookup_dev(chan->conn); 746 747 BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev); 748 749 if (!dev) { 750 if (setup_netdev(chan, &dev) < 0) { 751 l2cap_chan_del(chan, -ENOENT); 752 return; 753 } 754 new_netdev = true; 755 } 756 757 if (!try_module_get(THIS_MODULE)) 758 return; 759 760 add_peer_chan(chan, dev, new_netdev); 761 ifup(dev->netdev); 762 } 763 764 static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan) 765 { 766 struct l2cap_chan *chan; 767 768 chan = chan_create(); 769 if (!chan) 770 return NULL; 771 772 chan->ops = pchan->ops; 773 774 BT_DBG("chan %p pchan %p", chan, pchan); 775 776 return chan; 777 } 778 779 static void delete_netdev(struct work_struct *work) 780 { 781 struct lowpan_btle_dev *entry = container_of(work, 782 struct lowpan_btle_dev, 783 delete_netdev); 784 785 lowpan_unregister_netdev(entry->netdev); 786 787 /* The entry pointer is deleted by the netdev destructor. */ 788 } 789 790 static void chan_close_cb(struct l2cap_chan *chan) 791 { 792 struct lowpan_btle_dev *entry; 793 struct lowpan_btle_dev *dev = NULL; 794 struct lowpan_peer *peer; 795 int err = -ENOENT; 796 bool last = false, remove = true; 797 798 BT_DBG("chan %p conn %p", chan, chan->conn); 799 800 if (chan->conn && chan->conn->hcon) { 801 if (!is_bt_6lowpan(chan->conn->hcon)) 802 return; 803 804 /* If conn is set, then the netdev is also there and we should 805 * not remove it. 806 */ 807 remove = false; 808 } 809 810 spin_lock(&devices_lock); 811 812 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 813 dev = lowpan_btle_dev(entry->netdev); 814 peer = __peer_lookup_chan(dev, chan); 815 if (peer) { 816 last = peer_del(dev, peer); 817 err = 0; 818 819 BT_DBG("dev %p removing %speer %p", dev, 820 last ? "last " : "1 ", peer); 821 BT_DBG("chan %p orig refcnt %d", chan, 822 kref_read(&chan->kref)); 823 824 l2cap_chan_put(chan); 825 break; 826 } 827 } 828 829 if (!err && last && dev && !atomic_read(&dev->peer_count)) { 830 spin_unlock(&devices_lock); 831 832 cancel_delayed_work_sync(&dev->notify_peers); 833 834 ifdown(dev->netdev); 835 836 if (remove) { 837 INIT_WORK(&entry->delete_netdev, delete_netdev); 838 schedule_work(&entry->delete_netdev); 839 } 840 } else { 841 spin_unlock(&devices_lock); 842 } 843 844 return; 845 } 846 847 static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err) 848 { 849 BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn, 850 state_to_string(state), err); 851 } 852 853 static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan, 854 unsigned long hdr_len, 855 unsigned long len, int nb) 856 { 857 /* Note that we must allocate using GFP_ATOMIC here as 858 * this function is called originally from netdev hard xmit 859 * function in atomic context. 860 */ 861 return bt_skb_alloc(hdr_len + len, GFP_ATOMIC); 862 } 863 864 static void chan_suspend_cb(struct l2cap_chan *chan) 865 { 866 struct lowpan_btle_dev *dev; 867 868 BT_DBG("chan %p suspend", chan); 869 870 dev = lookup_dev(chan->conn); 871 if (!dev || !dev->netdev) 872 return; 873 874 netif_stop_queue(dev->netdev); 875 } 876 877 static void chan_resume_cb(struct l2cap_chan *chan) 878 { 879 struct lowpan_btle_dev *dev; 880 881 BT_DBG("chan %p resume", chan); 882 883 dev = lookup_dev(chan->conn); 884 if (!dev || !dev->netdev) 885 return; 886 887 netif_wake_queue(dev->netdev); 888 } 889 890 static long chan_get_sndtimeo_cb(struct l2cap_chan *chan) 891 { 892 return L2CAP_CONN_TIMEOUT; 893 } 894 895 static const struct l2cap_ops bt_6lowpan_chan_ops = { 896 .name = "L2CAP 6LoWPAN channel", 897 .new_connection = chan_new_conn_cb, 898 .recv = chan_recv_cb, 899 .close = chan_close_cb, 900 .state_change = chan_state_change_cb, 901 .ready = chan_ready_cb, 902 .resume = chan_resume_cb, 903 .suspend = chan_suspend_cb, 904 .get_sndtimeo = chan_get_sndtimeo_cb, 905 .alloc_skb = chan_alloc_skb_cb, 906 907 .teardown = l2cap_chan_no_teardown, 908 .defer = l2cap_chan_no_defer, 909 .set_shutdown = l2cap_chan_no_set_shutdown, 910 }; 911 912 static inline __u8 bdaddr_type(__u8 type) 913 { 914 if (type == ADDR_LE_DEV_PUBLIC) 915 return BDADDR_LE_PUBLIC; 916 else 917 return BDADDR_LE_RANDOM; 918 } 919 920 static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type) 921 { 922 struct l2cap_chan *chan; 923 int err; 924 925 chan = chan_create(); 926 if (!chan) 927 return -EINVAL; 928 929 chan->ops = &bt_6lowpan_chan_ops; 930 931 err = l2cap_chan_connect(chan, cpu_to_le16(L2CAP_PSM_IPSP), 0, 932 addr, dst_type); 933 934 BT_DBG("chan %p err %d", chan, err); 935 if (err < 0) 936 l2cap_chan_put(chan); 937 938 return err; 939 } 940 941 static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type) 942 { 943 struct lowpan_peer *peer; 944 945 BT_DBG("conn %p dst type %d", conn, dst_type); 946 947 peer = lookup_peer(conn); 948 if (!peer) 949 return -ENOENT; 950 951 BT_DBG("peer %p chan %p", peer, peer->chan); 952 953 l2cap_chan_close(peer->chan, ENOENT); 954 955 return 0; 956 } 957 958 static struct l2cap_chan *bt_6lowpan_listen(void) 959 { 960 bdaddr_t *addr = BDADDR_ANY; 961 struct l2cap_chan *chan; 962 int err; 963 964 if (!enable_6lowpan) 965 return NULL; 966 967 chan = chan_create(); 968 if (!chan) 969 return NULL; 970 971 chan->ops = &bt_6lowpan_chan_ops; 972 chan->state = BT_LISTEN; 973 chan->src_type = BDADDR_LE_PUBLIC; 974 975 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT); 976 977 BT_DBG("chan %p src type %d", chan, chan->src_type); 978 979 err = l2cap_add_psm(chan, addr, cpu_to_le16(L2CAP_PSM_IPSP)); 980 if (err) { 981 l2cap_chan_put(chan); 982 BT_ERR("psm cannot be added err %d", err); 983 return NULL; 984 } 985 986 return chan; 987 } 988 989 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type, 990 struct l2cap_conn **conn) 991 { 992 struct hci_conn *hcon; 993 struct hci_dev *hdev; 994 int n; 995 996 n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu", 997 &addr->b[5], &addr->b[4], &addr->b[3], 998 &addr->b[2], &addr->b[1], &addr->b[0], 999 addr_type); 1000 1001 if (n < 7) 1002 return -EINVAL; 1003 1004 /* The LE_PUBLIC address type is ignored because of BDADDR_ANY */ 1005 hdev = hci_get_route(addr, BDADDR_ANY, BDADDR_LE_PUBLIC); 1006 if (!hdev) 1007 return -ENOENT; 1008 1009 hci_dev_lock(hdev); 1010 hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type); 1011 hci_dev_unlock(hdev); 1012 1013 if (!hcon) 1014 return -ENOENT; 1015 1016 *conn = (struct l2cap_conn *)hcon->l2cap_data; 1017 1018 BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type); 1019 1020 return 0; 1021 } 1022 1023 static void disconnect_all_peers(void) 1024 { 1025 struct lowpan_btle_dev *entry; 1026 struct lowpan_peer *peer, *tmp_peer, *new_peer; 1027 struct list_head peers; 1028 1029 INIT_LIST_HEAD(&peers); 1030 1031 /* We make a separate list of peers as the close_cb() will 1032 * modify the device peers list so it is better not to mess 1033 * with the same list at the same time. 1034 */ 1035 1036 rcu_read_lock(); 1037 1038 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 1039 list_for_each_entry_rcu(peer, &entry->peers, list) { 1040 new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC); 1041 if (!new_peer) 1042 break; 1043 1044 new_peer->chan = peer->chan; 1045 INIT_LIST_HEAD(&new_peer->list); 1046 1047 list_add(&new_peer->list, &peers); 1048 } 1049 } 1050 1051 rcu_read_unlock(); 1052 1053 spin_lock(&devices_lock); 1054 list_for_each_entry_safe(peer, tmp_peer, &peers, list) { 1055 l2cap_chan_close(peer->chan, ENOENT); 1056 1057 list_del_rcu(&peer->list); 1058 kfree_rcu(peer, rcu); 1059 } 1060 spin_unlock(&devices_lock); 1061 } 1062 1063 struct set_enable { 1064 struct work_struct work; 1065 bool flag; 1066 }; 1067 1068 static void do_enable_set(struct work_struct *work) 1069 { 1070 struct set_enable *set_enable = container_of(work, 1071 struct set_enable, work); 1072 1073 if (!set_enable->flag || enable_6lowpan != set_enable->flag) 1074 /* Disconnect existing connections if 6lowpan is 1075 * disabled 1076 */ 1077 disconnect_all_peers(); 1078 1079 enable_6lowpan = set_enable->flag; 1080 1081 if (listen_chan) { 1082 l2cap_chan_close(listen_chan, 0); 1083 l2cap_chan_put(listen_chan); 1084 } 1085 1086 listen_chan = bt_6lowpan_listen(); 1087 1088 kfree(set_enable); 1089 } 1090 1091 static int lowpan_enable_set(void *data, u64 val) 1092 { 1093 struct set_enable *set_enable; 1094 1095 set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL); 1096 if (!set_enable) 1097 return -ENOMEM; 1098 1099 set_enable->flag = !!val; 1100 INIT_WORK(&set_enable->work, do_enable_set); 1101 1102 schedule_work(&set_enable->work); 1103 1104 return 0; 1105 } 1106 1107 static int lowpan_enable_get(void *data, u64 *val) 1108 { 1109 *val = enable_6lowpan; 1110 return 0; 1111 } 1112 1113 DEFINE_DEBUGFS_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get, 1114 lowpan_enable_set, "%llu\n"); 1115 1116 static ssize_t lowpan_control_write(struct file *fp, 1117 const char __user *user_buffer, 1118 size_t count, 1119 loff_t *position) 1120 { 1121 char buf[32]; 1122 size_t buf_size = min(count, sizeof(buf) - 1); 1123 int ret; 1124 bdaddr_t addr; 1125 u8 addr_type; 1126 struct l2cap_conn *conn = NULL; 1127 1128 if (copy_from_user(buf, user_buffer, buf_size)) 1129 return -EFAULT; 1130 1131 buf[buf_size] = '\0'; 1132 1133 if (memcmp(buf, "connect ", 8) == 0) { 1134 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn); 1135 if (ret == -EINVAL) 1136 return ret; 1137 1138 if (listen_chan) { 1139 l2cap_chan_close(listen_chan, 0); 1140 l2cap_chan_put(listen_chan); 1141 listen_chan = NULL; 1142 } 1143 1144 if (conn) { 1145 struct lowpan_peer *peer; 1146 1147 if (!is_bt_6lowpan(conn->hcon)) 1148 return -EINVAL; 1149 1150 peer = lookup_peer(conn); 1151 if (peer) { 1152 BT_DBG("6LoWPAN connection already exists"); 1153 return -EALREADY; 1154 } 1155 1156 BT_DBG("conn %p dst %pMR type %d user %d", conn, 1157 &conn->hcon->dst, conn->hcon->dst_type, 1158 addr_type); 1159 } 1160 1161 ret = bt_6lowpan_connect(&addr, addr_type); 1162 if (ret < 0) 1163 return ret; 1164 1165 return count; 1166 } 1167 1168 if (memcmp(buf, "disconnect ", 11) == 0) { 1169 ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn); 1170 if (ret < 0) 1171 return ret; 1172 1173 ret = bt_6lowpan_disconnect(conn, addr_type); 1174 if (ret < 0) 1175 return ret; 1176 1177 return count; 1178 } 1179 1180 return count; 1181 } 1182 1183 static int lowpan_control_show(struct seq_file *f, void *ptr) 1184 { 1185 struct lowpan_btle_dev *entry; 1186 struct lowpan_peer *peer; 1187 1188 spin_lock(&devices_lock); 1189 1190 list_for_each_entry(entry, &bt_6lowpan_devices, list) { 1191 list_for_each_entry(peer, &entry->peers, list) 1192 seq_printf(f, "%pMR (type %u)\n", 1193 &peer->chan->dst, peer->chan->dst_type); 1194 } 1195 1196 spin_unlock(&devices_lock); 1197 1198 return 0; 1199 } 1200 1201 static int lowpan_control_open(struct inode *inode, struct file *file) 1202 { 1203 return single_open(file, lowpan_control_show, inode->i_private); 1204 } 1205 1206 static const struct file_operations lowpan_control_fops = { 1207 .open = lowpan_control_open, 1208 .read = seq_read, 1209 .write = lowpan_control_write, 1210 .llseek = seq_lseek, 1211 .release = single_release, 1212 }; 1213 1214 static void disconnect_devices(void) 1215 { 1216 struct lowpan_btle_dev *entry, *tmp, *new_dev; 1217 struct list_head devices; 1218 1219 INIT_LIST_HEAD(&devices); 1220 1221 /* We make a separate list of devices because the unregister_netdev() 1222 * will call device_event() which will also want to modify the same 1223 * devices list. 1224 */ 1225 1226 rcu_read_lock(); 1227 1228 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 1229 new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC); 1230 if (!new_dev) 1231 break; 1232 1233 new_dev->netdev = entry->netdev; 1234 INIT_LIST_HEAD(&new_dev->list); 1235 1236 list_add_rcu(&new_dev->list, &devices); 1237 } 1238 1239 rcu_read_unlock(); 1240 1241 list_for_each_entry_safe(entry, tmp, &devices, list) { 1242 ifdown(entry->netdev); 1243 BT_DBG("Unregistering netdev %s %p", 1244 entry->netdev->name, entry->netdev); 1245 lowpan_unregister_netdev(entry->netdev); 1246 kfree(entry); 1247 } 1248 } 1249 1250 static int device_event(struct notifier_block *unused, 1251 unsigned long event, void *ptr) 1252 { 1253 struct net_device *netdev = netdev_notifier_info_to_dev(ptr); 1254 struct lowpan_btle_dev *entry; 1255 1256 if (netdev->type != ARPHRD_6LOWPAN) 1257 return NOTIFY_DONE; 1258 1259 switch (event) { 1260 case NETDEV_UNREGISTER: 1261 spin_lock(&devices_lock); 1262 list_for_each_entry(entry, &bt_6lowpan_devices, list) { 1263 if (entry->netdev == netdev) { 1264 BT_DBG("Unregistered netdev %s %p", 1265 netdev->name, netdev); 1266 list_del(&entry->list); 1267 break; 1268 } 1269 } 1270 spin_unlock(&devices_lock); 1271 break; 1272 } 1273 1274 return NOTIFY_DONE; 1275 } 1276 1277 static struct notifier_block bt_6lowpan_dev_notifier = { 1278 .notifier_call = device_event, 1279 }; 1280 1281 static int __init bt_6lowpan_init(void) 1282 { 1283 lowpan_enable_debugfs = debugfs_create_file_unsafe("6lowpan_enable", 1284 0644, bt_debugfs, 1285 NULL, 1286 &lowpan_enable_fops); 1287 lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644, 1288 bt_debugfs, NULL, 1289 &lowpan_control_fops); 1290 1291 return register_netdevice_notifier(&bt_6lowpan_dev_notifier); 1292 } 1293 1294 static void __exit bt_6lowpan_exit(void) 1295 { 1296 debugfs_remove(lowpan_enable_debugfs); 1297 debugfs_remove(lowpan_control_debugfs); 1298 1299 if (listen_chan) { 1300 l2cap_chan_close(listen_chan, 0); 1301 l2cap_chan_put(listen_chan); 1302 } 1303 1304 disconnect_devices(); 1305 1306 unregister_netdevice_notifier(&bt_6lowpan_dev_notifier); 1307 } 1308 1309 module_init(bt_6lowpan_init); 1310 module_exit(bt_6lowpan_exit); 1311 1312 MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>"); 1313 MODULE_DESCRIPTION("Bluetooth 6LoWPAN"); 1314 MODULE_VERSION(VERSION); 1315 MODULE_LICENSE("GPL"); 1316