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 *peer_lookup_ba(struct lowpan_btle_dev *dev, 107 bdaddr_t *ba, __u8 type) 108 { 109 struct lowpan_peer *peer; 110 111 BT_DBG("peers %d addr %pMR type %d", atomic_read(&dev->peer_count), 112 ba, type); 113 114 rcu_read_lock(); 115 116 list_for_each_entry_rcu(peer, &dev->peers, list) { 117 BT_DBG("dst addr %pMR dst type %d", 118 &peer->chan->dst, peer->chan->dst_type); 119 120 if (bacmp(&peer->chan->dst, ba)) 121 continue; 122 123 if (type == peer->chan->dst_type) { 124 rcu_read_unlock(); 125 return peer; 126 } 127 } 128 129 rcu_read_unlock(); 130 131 return NULL; 132 } 133 134 static inline struct lowpan_peer * 135 __peer_lookup_chan(struct lowpan_btle_dev *dev, struct l2cap_chan *chan) 136 { 137 struct lowpan_peer *peer; 138 139 list_for_each_entry_rcu(peer, &dev->peers, list) { 140 if (peer->chan == chan) 141 return peer; 142 } 143 144 return NULL; 145 } 146 147 static inline struct lowpan_peer * 148 __peer_lookup_conn(struct lowpan_btle_dev *dev, struct l2cap_conn *conn) 149 { 150 struct lowpan_peer *peer; 151 152 list_for_each_entry_rcu(peer, &dev->peers, list) { 153 if (peer->chan->conn == conn) 154 return peer; 155 } 156 157 return NULL; 158 } 159 160 static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_btle_dev *dev, 161 struct in6_addr *daddr, 162 struct sk_buff *skb) 163 { 164 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb); 165 int count = atomic_read(&dev->peer_count); 166 const struct in6_addr *nexthop; 167 struct lowpan_peer *peer; 168 struct neighbour *neigh; 169 170 BT_DBG("peers %d addr %pI6c rt %p", count, daddr, rt); 171 172 if (!rt) { 173 if (ipv6_addr_any(&lowpan_cb(skb)->gw)) { 174 /* There is neither route nor gateway, 175 * probably the destination is a direct peer. 176 */ 177 nexthop = daddr; 178 } else { 179 /* There is a known gateway 180 */ 181 nexthop = &lowpan_cb(skb)->gw; 182 } 183 } else { 184 nexthop = rt6_nexthop(rt, daddr); 185 186 /* We need to remember the address because it is needed 187 * by bt_xmit() when sending the packet. In bt_xmit(), the 188 * destination routing info is not set. 189 */ 190 memcpy(&lowpan_cb(skb)->gw, nexthop, sizeof(struct in6_addr)); 191 } 192 193 BT_DBG("gw %pI6c", nexthop); 194 195 rcu_read_lock(); 196 197 list_for_each_entry_rcu(peer, &dev->peers, list) { 198 BT_DBG("dst addr %pMR dst type %d ip %pI6c", 199 &peer->chan->dst, peer->chan->dst_type, 200 &peer->peer_addr); 201 202 if (!ipv6_addr_cmp(&peer->peer_addr, nexthop)) { 203 rcu_read_unlock(); 204 return peer; 205 } 206 } 207 208 /* use the neighbour cache for matching addresses assigned by SLAAC 209 */ 210 neigh = __ipv6_neigh_lookup(dev->netdev, nexthop); 211 if (neigh) { 212 list_for_each_entry_rcu(peer, &dev->peers, list) { 213 if (!memcmp(neigh->ha, peer->lladdr, ETH_ALEN)) { 214 neigh_release(neigh); 215 rcu_read_unlock(); 216 return peer; 217 } 218 } 219 neigh_release(neigh); 220 } 221 222 rcu_read_unlock(); 223 224 return NULL; 225 } 226 227 static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn) 228 { 229 struct lowpan_btle_dev *entry; 230 struct lowpan_peer *peer = NULL; 231 232 rcu_read_lock(); 233 234 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 235 peer = __peer_lookup_conn(entry, conn); 236 if (peer) 237 break; 238 } 239 240 rcu_read_unlock(); 241 242 return peer; 243 } 244 245 static struct lowpan_btle_dev *lookup_dev(struct l2cap_conn *conn) 246 { 247 struct lowpan_btle_dev *entry; 248 struct lowpan_btle_dev *dev = NULL; 249 250 rcu_read_lock(); 251 252 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 253 if (conn->hcon->hdev == entry->hdev) { 254 dev = entry; 255 break; 256 } 257 } 258 259 rcu_read_unlock(); 260 261 return dev; 262 } 263 264 static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev) 265 { 266 struct sk_buff *skb_cp; 267 268 skb_cp = skb_copy(skb, GFP_ATOMIC); 269 if (!skb_cp) 270 return NET_RX_DROP; 271 272 return netif_rx_ni(skb_cp); 273 } 274 275 static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev, 276 struct lowpan_peer *peer) 277 { 278 const u8 *saddr; 279 280 saddr = peer->lladdr; 281 282 return lowpan_header_decompress(skb, netdev, netdev->dev_addr, saddr); 283 } 284 285 static int recv_pkt(struct sk_buff *skb, struct net_device *dev, 286 struct lowpan_peer *peer) 287 { 288 struct sk_buff *local_skb; 289 int ret; 290 291 if (!netif_running(dev)) 292 goto drop; 293 294 if (dev->type != ARPHRD_6LOWPAN || !skb->len) 295 goto drop; 296 297 skb_reset_network_header(skb); 298 299 skb = skb_share_check(skb, GFP_ATOMIC); 300 if (!skb) 301 goto drop; 302 303 /* check that it's our buffer */ 304 if (lowpan_is_ipv6(*skb_network_header(skb))) { 305 /* Pull off the 1-byte of 6lowpan header. */ 306 skb_pull(skb, 1); 307 308 /* Copy the packet so that the IPv6 header is 309 * properly aligned. 310 */ 311 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1, 312 skb_tailroom(skb), GFP_ATOMIC); 313 if (!local_skb) 314 goto drop; 315 316 local_skb->protocol = htons(ETH_P_IPV6); 317 local_skb->pkt_type = PACKET_HOST; 318 local_skb->dev = dev; 319 320 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr)); 321 322 if (give_skb_to_upper(local_skb, dev) != 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 if (lowpan_is_iphc(*skb_network_header(skb))) { 333 local_skb = skb_clone(skb, GFP_ATOMIC); 334 if (!local_skb) 335 goto drop; 336 337 local_skb->dev = dev; 338 339 ret = iphc_decompress(local_skb, dev, peer); 340 if (ret < 0) { 341 BT_DBG("iphc_decompress failed: %d", ret); 342 kfree_skb(local_skb); 343 goto drop; 344 } 345 346 local_skb->protocol = htons(ETH_P_IPV6); 347 local_skb->pkt_type = PACKET_HOST; 348 349 if (give_skb_to_upper(local_skb, dev) 350 != NET_RX_SUCCESS) { 351 kfree_skb(local_skb); 352 goto drop; 353 } 354 355 dev->stats.rx_bytes += skb->len; 356 dev->stats.rx_packets++; 357 358 consume_skb(local_skb); 359 consume_skb(skb); 360 } else { 361 BT_DBG("unknown packet type"); 362 goto drop; 363 } 364 365 return NET_RX_SUCCESS; 366 367 drop: 368 dev->stats.rx_dropped++; 369 return NET_RX_DROP; 370 } 371 372 /* Packet from BT LE device */ 373 static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) 374 { 375 struct lowpan_btle_dev *dev; 376 struct lowpan_peer *peer; 377 int err; 378 379 peer = lookup_peer(chan->conn); 380 if (!peer) 381 return -ENOENT; 382 383 dev = lookup_dev(chan->conn); 384 if (!dev || !dev->netdev) 385 return -ENOENT; 386 387 err = recv_pkt(skb, dev->netdev, peer); 388 if (err) { 389 BT_DBG("recv pkt %d", err); 390 err = -EAGAIN; 391 } 392 393 return err; 394 } 395 396 static int setup_header(struct sk_buff *skb, struct net_device *netdev, 397 bdaddr_t *peer_addr, u8 *peer_addr_type) 398 { 399 struct in6_addr ipv6_daddr; 400 struct ipv6hdr *hdr; 401 struct lowpan_btle_dev *dev; 402 struct lowpan_peer *peer; 403 u8 *daddr; 404 int err, status = 0; 405 406 hdr = ipv6_hdr(skb); 407 408 dev = lowpan_btle_dev(netdev); 409 410 memcpy(&ipv6_daddr, &hdr->daddr, sizeof(ipv6_daddr)); 411 412 if (ipv6_addr_is_multicast(&ipv6_daddr)) { 413 lowpan_cb(skb)->chan = NULL; 414 daddr = NULL; 415 } else { 416 BT_DBG("dest IP %pI6c", &ipv6_daddr); 417 418 /* The packet might be sent to 6lowpan interface 419 * because of routing (either via default route 420 * or user set route) so get peer according to 421 * the destination address. 422 */ 423 peer = peer_lookup_dst(dev, &ipv6_daddr, skb); 424 if (!peer) { 425 BT_DBG("no such peer"); 426 return -ENOENT; 427 } 428 429 daddr = peer->lladdr; 430 *peer_addr = peer->chan->dst; 431 *peer_addr_type = peer->chan->dst_type; 432 lowpan_cb(skb)->chan = peer->chan; 433 434 status = 1; 435 } 436 437 lowpan_header_compress(skb, netdev, daddr, dev->netdev->dev_addr); 438 439 err = dev_hard_header(skb, netdev, ETH_P_IPV6, NULL, NULL, 0); 440 if (err < 0) 441 return err; 442 443 return status; 444 } 445 446 static int header_create(struct sk_buff *skb, struct net_device *netdev, 447 unsigned short type, const void *_daddr, 448 const void *_saddr, unsigned int len) 449 { 450 if (type != ETH_P_IPV6) 451 return -EINVAL; 452 453 return 0; 454 } 455 456 /* Packet to BT LE device */ 457 static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb, 458 struct net_device *netdev) 459 { 460 struct msghdr msg; 461 struct kvec iv; 462 int err; 463 464 /* Remember the skb so that we can send EAGAIN to the caller if 465 * we run out of credits. 466 */ 467 chan->data = skb; 468 469 iv.iov_base = skb->data; 470 iv.iov_len = skb->len; 471 472 memset(&msg, 0, sizeof(msg)); 473 iov_iter_kvec(&msg.msg_iter, WRITE, &iv, 1, skb->len); 474 475 err = l2cap_chan_send(chan, &msg, skb->len); 476 if (err > 0) { 477 netdev->stats.tx_bytes += err; 478 netdev->stats.tx_packets++; 479 return 0; 480 } 481 482 if (err < 0) 483 netdev->stats.tx_errors++; 484 485 return err; 486 } 487 488 static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev) 489 { 490 struct sk_buff *local_skb; 491 struct lowpan_btle_dev *entry; 492 int err = 0; 493 494 rcu_read_lock(); 495 496 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 497 struct lowpan_peer *pentry; 498 struct lowpan_btle_dev *dev; 499 500 if (entry->netdev != netdev) 501 continue; 502 503 dev = lowpan_btle_dev(entry->netdev); 504 505 list_for_each_entry_rcu(pentry, &dev->peers, list) { 506 int ret; 507 508 local_skb = skb_clone(skb, GFP_ATOMIC); 509 510 BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p", 511 netdev->name, 512 &pentry->chan->dst, pentry->chan->dst_type, 513 &pentry->peer_addr, pentry->chan); 514 ret = send_pkt(pentry->chan, local_skb, netdev); 515 if (ret < 0) 516 err = ret; 517 518 kfree_skb(local_skb); 519 } 520 } 521 522 rcu_read_unlock(); 523 524 return err; 525 } 526 527 static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev) 528 { 529 int err = 0; 530 bdaddr_t addr; 531 u8 addr_type; 532 533 /* We must take a copy of the skb before we modify/replace the ipv6 534 * header as the header could be used elsewhere 535 */ 536 skb = skb_unshare(skb, GFP_ATOMIC); 537 if (!skb) 538 return NET_XMIT_DROP; 539 540 /* Return values from setup_header() 541 * <0 - error, packet is dropped 542 * 0 - this is a multicast packet 543 * 1 - this is unicast packet 544 */ 545 err = setup_header(skb, netdev, &addr, &addr_type); 546 if (err < 0) { 547 kfree_skb(skb); 548 return NET_XMIT_DROP; 549 } 550 551 if (err) { 552 if (lowpan_cb(skb)->chan) { 553 BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p", 554 netdev->name, &addr, addr_type, 555 &lowpan_cb(skb)->addr, lowpan_cb(skb)->chan); 556 err = send_pkt(lowpan_cb(skb)->chan, skb, netdev); 557 } else { 558 err = -ENOENT; 559 } 560 } else { 561 /* We need to send the packet to every device behind this 562 * interface. 563 */ 564 err = send_mcast_pkt(skb, netdev); 565 } 566 567 dev_kfree_skb(skb); 568 569 if (err) 570 BT_DBG("ERROR: xmit failed (%d)", err); 571 572 return err < 0 ? NET_XMIT_DROP : err; 573 } 574 575 static int bt_dev_init(struct net_device *dev) 576 { 577 netdev_lockdep_set_classes(dev); 578 579 return 0; 580 } 581 582 static const struct net_device_ops netdev_ops = { 583 .ndo_init = bt_dev_init, 584 .ndo_start_xmit = bt_xmit, 585 }; 586 587 static const struct header_ops header_ops = { 588 .create = header_create, 589 }; 590 591 static void netdev_setup(struct net_device *dev) 592 { 593 dev->hard_header_len = 0; 594 dev->needed_tailroom = 0; 595 dev->flags = IFF_RUNNING | IFF_MULTICAST; 596 dev->watchdog_timeo = 0; 597 dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN; 598 599 dev->netdev_ops = &netdev_ops; 600 dev->header_ops = &header_ops; 601 dev->needs_free_netdev = true; 602 } 603 604 static struct device_type bt_type = { 605 .name = "bluetooth", 606 }; 607 608 static void ifup(struct net_device *netdev) 609 { 610 int err; 611 612 rtnl_lock(); 613 err = dev_open(netdev, NULL); 614 if (err < 0) 615 BT_INFO("iface %s cannot be opened (%d)", netdev->name, err); 616 rtnl_unlock(); 617 } 618 619 static void ifdown(struct net_device *netdev) 620 { 621 rtnl_lock(); 622 dev_close(netdev); 623 rtnl_unlock(); 624 } 625 626 static void do_notify_peers(struct work_struct *work) 627 { 628 struct lowpan_btle_dev *dev = container_of(work, struct lowpan_btle_dev, 629 notify_peers.work); 630 631 netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */ 632 } 633 634 static bool is_bt_6lowpan(struct hci_conn *hcon) 635 { 636 if (hcon->type != LE_LINK) 637 return false; 638 639 if (!enable_6lowpan) 640 return false; 641 642 return true; 643 } 644 645 static struct l2cap_chan *chan_create(void) 646 { 647 struct l2cap_chan *chan; 648 649 chan = l2cap_chan_create(); 650 if (!chan) 651 return NULL; 652 653 l2cap_chan_set_defaults(chan); 654 655 chan->chan_type = L2CAP_CHAN_CONN_ORIENTED; 656 chan->mode = L2CAP_MODE_LE_FLOWCTL; 657 chan->imtu = 1280; 658 659 return chan; 660 } 661 662 static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan, 663 struct lowpan_btle_dev *dev, 664 bool new_netdev) 665 { 666 struct lowpan_peer *peer; 667 668 peer = kzalloc(sizeof(*peer), GFP_ATOMIC); 669 if (!peer) 670 return NULL; 671 672 peer->chan = chan; 673 memset(&peer->peer_addr, 0, sizeof(struct in6_addr)); 674 675 baswap((void *)peer->lladdr, &chan->dst); 676 677 lowpan_iphc_uncompress_eui48_lladdr(&peer->peer_addr, peer->lladdr); 678 679 spin_lock(&devices_lock); 680 INIT_LIST_HEAD(&peer->list); 681 peer_add(dev, peer); 682 spin_unlock(&devices_lock); 683 684 /* Notifying peers about us needs to be done without locks held */ 685 if (new_netdev) 686 INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers); 687 schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100)); 688 689 return peer->chan; 690 } 691 692 static int setup_netdev(struct l2cap_chan *chan, struct lowpan_btle_dev **dev) 693 { 694 struct net_device *netdev; 695 int err = 0; 696 697 netdev = alloc_netdev(LOWPAN_PRIV_SIZE(sizeof(struct lowpan_btle_dev)), 698 IFACE_NAME_TEMPLATE, NET_NAME_UNKNOWN, 699 netdev_setup); 700 if (!netdev) 701 return -ENOMEM; 702 703 netdev->addr_assign_type = NET_ADDR_PERM; 704 baswap((void *)netdev->dev_addr, &chan->src); 705 706 netdev->netdev_ops = &netdev_ops; 707 SET_NETDEV_DEV(netdev, &chan->conn->hcon->hdev->dev); 708 SET_NETDEV_DEVTYPE(netdev, &bt_type); 709 710 *dev = lowpan_btle_dev(netdev); 711 (*dev)->netdev = netdev; 712 (*dev)->hdev = chan->conn->hcon->hdev; 713 INIT_LIST_HEAD(&(*dev)->peers); 714 715 spin_lock(&devices_lock); 716 INIT_LIST_HEAD(&(*dev)->list); 717 list_add_rcu(&(*dev)->list, &bt_6lowpan_devices); 718 spin_unlock(&devices_lock); 719 720 err = lowpan_register_netdev(netdev, LOWPAN_LLTYPE_BTLE); 721 if (err < 0) { 722 BT_INFO("register_netdev failed %d", err); 723 spin_lock(&devices_lock); 724 list_del_rcu(&(*dev)->list); 725 spin_unlock(&devices_lock); 726 free_netdev(netdev); 727 goto out; 728 } 729 730 BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d", 731 netdev->ifindex, &chan->dst, chan->dst_type, 732 &chan->src, chan->src_type); 733 set_bit(__LINK_STATE_PRESENT, &netdev->state); 734 735 return 0; 736 737 out: 738 return err; 739 } 740 741 static inline void chan_ready_cb(struct l2cap_chan *chan) 742 { 743 struct lowpan_btle_dev *dev; 744 bool new_netdev = false; 745 746 dev = lookup_dev(chan->conn); 747 748 BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev); 749 750 if (!dev) { 751 if (setup_netdev(chan, &dev) < 0) { 752 l2cap_chan_del(chan, -ENOENT); 753 return; 754 } 755 new_netdev = true; 756 } 757 758 if (!try_module_get(THIS_MODULE)) 759 return; 760 761 add_peer_chan(chan, dev, new_netdev); 762 ifup(dev->netdev); 763 } 764 765 static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan) 766 { 767 struct l2cap_chan *chan; 768 769 chan = chan_create(); 770 if (!chan) 771 return NULL; 772 773 chan->ops = pchan->ops; 774 775 BT_DBG("chan %p pchan %p", chan, pchan); 776 777 return chan; 778 } 779 780 static void delete_netdev(struct work_struct *work) 781 { 782 struct lowpan_btle_dev *entry = container_of(work, 783 struct lowpan_btle_dev, 784 delete_netdev); 785 786 lowpan_unregister_netdev(entry->netdev); 787 788 /* The entry pointer is deleted by the netdev destructor. */ 789 } 790 791 static void chan_close_cb(struct l2cap_chan *chan) 792 { 793 struct lowpan_btle_dev *entry; 794 struct lowpan_btle_dev *dev = NULL; 795 struct lowpan_peer *peer; 796 int err = -ENOENT; 797 bool last = false, remove = true; 798 799 BT_DBG("chan %p conn %p", chan, chan->conn); 800 801 if (chan->conn && chan->conn->hcon) { 802 if (!is_bt_6lowpan(chan->conn->hcon)) 803 return; 804 805 /* If conn is set, then the netdev is also there and we should 806 * not remove it. 807 */ 808 remove = false; 809 } 810 811 spin_lock(&devices_lock); 812 813 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 814 dev = lowpan_btle_dev(entry->netdev); 815 peer = __peer_lookup_chan(dev, chan); 816 if (peer) { 817 last = peer_del(dev, peer); 818 err = 0; 819 820 BT_DBG("dev %p removing %speer %p", dev, 821 last ? "last " : "1 ", peer); 822 BT_DBG("chan %p orig refcnt %d", chan, 823 kref_read(&chan->kref)); 824 825 l2cap_chan_put(chan); 826 break; 827 } 828 } 829 830 if (!err && last && dev && !atomic_read(&dev->peer_count)) { 831 spin_unlock(&devices_lock); 832 833 cancel_delayed_work_sync(&dev->notify_peers); 834 835 ifdown(dev->netdev); 836 837 if (remove) { 838 INIT_WORK(&entry->delete_netdev, delete_netdev); 839 schedule_work(&entry->delete_netdev); 840 } 841 } else { 842 spin_unlock(&devices_lock); 843 } 844 845 return; 846 } 847 848 static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err) 849 { 850 BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn, 851 state_to_string(state), err); 852 } 853 854 static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan, 855 unsigned long hdr_len, 856 unsigned long len, int nb) 857 { 858 /* Note that we must allocate using GFP_ATOMIC here as 859 * this function is called originally from netdev hard xmit 860 * function in atomic context. 861 */ 862 return bt_skb_alloc(hdr_len + len, GFP_ATOMIC); 863 } 864 865 static void chan_suspend_cb(struct l2cap_chan *chan) 866 { 867 struct lowpan_btle_dev *dev; 868 869 BT_DBG("chan %p suspend", chan); 870 871 dev = lookup_dev(chan->conn); 872 if (!dev || !dev->netdev) 873 return; 874 875 netif_stop_queue(dev->netdev); 876 } 877 878 static void chan_resume_cb(struct l2cap_chan *chan) 879 { 880 struct lowpan_btle_dev *dev; 881 882 BT_DBG("chan %p resume", chan); 883 884 dev = lookup_dev(chan->conn); 885 if (!dev || !dev->netdev) 886 return; 887 888 netif_wake_queue(dev->netdev); 889 } 890 891 static long chan_get_sndtimeo_cb(struct l2cap_chan *chan) 892 { 893 return L2CAP_CONN_TIMEOUT; 894 } 895 896 static const struct l2cap_ops bt_6lowpan_chan_ops = { 897 .name = "L2CAP 6LoWPAN channel", 898 .new_connection = chan_new_conn_cb, 899 .recv = chan_recv_cb, 900 .close = chan_close_cb, 901 .state_change = chan_state_change_cb, 902 .ready = chan_ready_cb, 903 .resume = chan_resume_cb, 904 .suspend = chan_suspend_cb, 905 .get_sndtimeo = chan_get_sndtimeo_cb, 906 .alloc_skb = chan_alloc_skb_cb, 907 908 .teardown = l2cap_chan_no_teardown, 909 .defer = l2cap_chan_no_defer, 910 .set_shutdown = l2cap_chan_no_set_shutdown, 911 }; 912 913 static inline __u8 bdaddr_type(__u8 type) 914 { 915 if (type == ADDR_LE_DEV_PUBLIC) 916 return BDADDR_LE_PUBLIC; 917 else 918 return BDADDR_LE_RANDOM; 919 } 920 921 static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type) 922 { 923 struct l2cap_chan *chan; 924 int err; 925 926 chan = chan_create(); 927 if (!chan) 928 return -EINVAL; 929 930 chan->ops = &bt_6lowpan_chan_ops; 931 932 err = l2cap_chan_connect(chan, cpu_to_le16(L2CAP_PSM_IPSP), 0, 933 addr, dst_type); 934 935 BT_DBG("chan %p err %d", chan, err); 936 if (err < 0) 937 l2cap_chan_put(chan); 938 939 return err; 940 } 941 942 static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type) 943 { 944 struct lowpan_peer *peer; 945 946 BT_DBG("conn %p dst type %d", conn, dst_type); 947 948 peer = lookup_peer(conn); 949 if (!peer) 950 return -ENOENT; 951 952 BT_DBG("peer %p chan %p", peer, peer->chan); 953 954 l2cap_chan_close(peer->chan, ENOENT); 955 956 return 0; 957 } 958 959 static struct l2cap_chan *bt_6lowpan_listen(void) 960 { 961 bdaddr_t *addr = BDADDR_ANY; 962 struct l2cap_chan *chan; 963 int err; 964 965 if (!enable_6lowpan) 966 return NULL; 967 968 chan = chan_create(); 969 if (!chan) 970 return NULL; 971 972 chan->ops = &bt_6lowpan_chan_ops; 973 chan->state = BT_LISTEN; 974 chan->src_type = BDADDR_LE_PUBLIC; 975 976 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT); 977 978 BT_DBG("chan %p src type %d", chan, chan->src_type); 979 980 err = l2cap_add_psm(chan, addr, cpu_to_le16(L2CAP_PSM_IPSP)); 981 if (err) { 982 l2cap_chan_put(chan); 983 BT_ERR("psm cannot be added err %d", err); 984 return NULL; 985 } 986 987 return chan; 988 } 989 990 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type, 991 struct l2cap_conn **conn) 992 { 993 struct hci_conn *hcon; 994 struct hci_dev *hdev; 995 int n; 996 997 n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu", 998 &addr->b[5], &addr->b[4], &addr->b[3], 999 &addr->b[2], &addr->b[1], &addr->b[0], 1000 addr_type); 1001 1002 if (n < 7) 1003 return -EINVAL; 1004 1005 /* The LE_PUBLIC address type is ignored because of BDADDR_ANY */ 1006 hdev = hci_get_route(addr, BDADDR_ANY, BDADDR_LE_PUBLIC); 1007 if (!hdev) 1008 return -ENOENT; 1009 1010 hci_dev_lock(hdev); 1011 hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type); 1012 hci_dev_unlock(hdev); 1013 1014 if (!hcon) 1015 return -ENOENT; 1016 1017 *conn = (struct l2cap_conn *)hcon->l2cap_data; 1018 1019 BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type); 1020 1021 return 0; 1022 } 1023 1024 static void disconnect_all_peers(void) 1025 { 1026 struct lowpan_btle_dev *entry; 1027 struct lowpan_peer *peer, *tmp_peer, *new_peer; 1028 struct list_head peers; 1029 1030 INIT_LIST_HEAD(&peers); 1031 1032 /* We make a separate list of peers as the close_cb() will 1033 * modify the device peers list so it is better not to mess 1034 * with the same list at the same time. 1035 */ 1036 1037 rcu_read_lock(); 1038 1039 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 1040 list_for_each_entry_rcu(peer, &entry->peers, list) { 1041 new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC); 1042 if (!new_peer) 1043 break; 1044 1045 new_peer->chan = peer->chan; 1046 INIT_LIST_HEAD(&new_peer->list); 1047 1048 list_add(&new_peer->list, &peers); 1049 } 1050 } 1051 1052 rcu_read_unlock(); 1053 1054 spin_lock(&devices_lock); 1055 list_for_each_entry_safe(peer, tmp_peer, &peers, list) { 1056 l2cap_chan_close(peer->chan, ENOENT); 1057 1058 list_del_rcu(&peer->list); 1059 kfree_rcu(peer, rcu); 1060 } 1061 spin_unlock(&devices_lock); 1062 } 1063 1064 struct set_enable { 1065 struct work_struct work; 1066 bool flag; 1067 }; 1068 1069 static void do_enable_set(struct work_struct *work) 1070 { 1071 struct set_enable *set_enable = container_of(work, 1072 struct set_enable, work); 1073 1074 if (!set_enable->flag || enable_6lowpan != set_enable->flag) 1075 /* Disconnect existing connections if 6lowpan is 1076 * disabled 1077 */ 1078 disconnect_all_peers(); 1079 1080 enable_6lowpan = set_enable->flag; 1081 1082 mutex_lock(&set_lock); 1083 if (listen_chan) { 1084 l2cap_chan_close(listen_chan, 0); 1085 l2cap_chan_put(listen_chan); 1086 } 1087 1088 listen_chan = bt_6lowpan_listen(); 1089 mutex_unlock(&set_lock); 1090 1091 kfree(set_enable); 1092 } 1093 1094 static int lowpan_enable_set(void *data, u64 val) 1095 { 1096 struct set_enable *set_enable; 1097 1098 set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL); 1099 if (!set_enable) 1100 return -ENOMEM; 1101 1102 set_enable->flag = !!val; 1103 INIT_WORK(&set_enable->work, do_enable_set); 1104 1105 schedule_work(&set_enable->work); 1106 1107 return 0; 1108 } 1109 1110 static int lowpan_enable_get(void *data, u64 *val) 1111 { 1112 *val = enable_6lowpan; 1113 return 0; 1114 } 1115 1116 DEFINE_DEBUGFS_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get, 1117 lowpan_enable_set, "%llu\n"); 1118 1119 static ssize_t lowpan_control_write(struct file *fp, 1120 const char __user *user_buffer, 1121 size_t count, 1122 loff_t *position) 1123 { 1124 char buf[32]; 1125 size_t buf_size = min(count, sizeof(buf) - 1); 1126 int ret; 1127 bdaddr_t addr; 1128 u8 addr_type; 1129 struct l2cap_conn *conn = NULL; 1130 1131 if (copy_from_user(buf, user_buffer, buf_size)) 1132 return -EFAULT; 1133 1134 buf[buf_size] = '\0'; 1135 1136 if (memcmp(buf, "connect ", 8) == 0) { 1137 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn); 1138 if (ret == -EINVAL) 1139 return ret; 1140 1141 mutex_lock(&set_lock); 1142 if (listen_chan) { 1143 l2cap_chan_close(listen_chan, 0); 1144 l2cap_chan_put(listen_chan); 1145 listen_chan = NULL; 1146 } 1147 mutex_unlock(&set_lock); 1148 1149 if (conn) { 1150 struct lowpan_peer *peer; 1151 1152 if (!is_bt_6lowpan(conn->hcon)) 1153 return -EINVAL; 1154 1155 peer = lookup_peer(conn); 1156 if (peer) { 1157 BT_DBG("6LoWPAN connection already exists"); 1158 return -EALREADY; 1159 } 1160 1161 BT_DBG("conn %p dst %pMR type %d user %d", conn, 1162 &conn->hcon->dst, conn->hcon->dst_type, 1163 addr_type); 1164 } 1165 1166 ret = bt_6lowpan_connect(&addr, addr_type); 1167 if (ret < 0) 1168 return ret; 1169 1170 return count; 1171 } 1172 1173 if (memcmp(buf, "disconnect ", 11) == 0) { 1174 ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn); 1175 if (ret < 0) 1176 return ret; 1177 1178 ret = bt_6lowpan_disconnect(conn, addr_type); 1179 if (ret < 0) 1180 return ret; 1181 1182 return count; 1183 } 1184 1185 return count; 1186 } 1187 1188 static int lowpan_control_show(struct seq_file *f, void *ptr) 1189 { 1190 struct lowpan_btle_dev *entry; 1191 struct lowpan_peer *peer; 1192 1193 spin_lock(&devices_lock); 1194 1195 list_for_each_entry(entry, &bt_6lowpan_devices, list) { 1196 list_for_each_entry(peer, &entry->peers, list) 1197 seq_printf(f, "%pMR (type %u)\n", 1198 &peer->chan->dst, peer->chan->dst_type); 1199 } 1200 1201 spin_unlock(&devices_lock); 1202 1203 return 0; 1204 } 1205 1206 static int lowpan_control_open(struct inode *inode, struct file *file) 1207 { 1208 return single_open(file, lowpan_control_show, inode->i_private); 1209 } 1210 1211 static const struct file_operations lowpan_control_fops = { 1212 .open = lowpan_control_open, 1213 .read = seq_read, 1214 .write = lowpan_control_write, 1215 .llseek = seq_lseek, 1216 .release = single_release, 1217 }; 1218 1219 static void disconnect_devices(void) 1220 { 1221 struct lowpan_btle_dev *entry, *tmp, *new_dev; 1222 struct list_head devices; 1223 1224 INIT_LIST_HEAD(&devices); 1225 1226 /* We make a separate list of devices because the unregister_netdev() 1227 * will call device_event() which will also want to modify the same 1228 * devices list. 1229 */ 1230 1231 rcu_read_lock(); 1232 1233 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 1234 new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC); 1235 if (!new_dev) 1236 break; 1237 1238 new_dev->netdev = entry->netdev; 1239 INIT_LIST_HEAD(&new_dev->list); 1240 1241 list_add_rcu(&new_dev->list, &devices); 1242 } 1243 1244 rcu_read_unlock(); 1245 1246 list_for_each_entry_safe(entry, tmp, &devices, list) { 1247 ifdown(entry->netdev); 1248 BT_DBG("Unregistering netdev %s %p", 1249 entry->netdev->name, entry->netdev); 1250 lowpan_unregister_netdev(entry->netdev); 1251 kfree(entry); 1252 } 1253 } 1254 1255 static int device_event(struct notifier_block *unused, 1256 unsigned long event, void *ptr) 1257 { 1258 struct net_device *netdev = netdev_notifier_info_to_dev(ptr); 1259 struct lowpan_btle_dev *entry; 1260 1261 if (netdev->type != ARPHRD_6LOWPAN) 1262 return NOTIFY_DONE; 1263 1264 switch (event) { 1265 case NETDEV_UNREGISTER: 1266 spin_lock(&devices_lock); 1267 list_for_each_entry(entry, &bt_6lowpan_devices, list) { 1268 if (entry->netdev == netdev) { 1269 BT_DBG("Unregistered netdev %s %p", 1270 netdev->name, netdev); 1271 list_del(&entry->list); 1272 break; 1273 } 1274 } 1275 spin_unlock(&devices_lock); 1276 break; 1277 } 1278 1279 return NOTIFY_DONE; 1280 } 1281 1282 static struct notifier_block bt_6lowpan_dev_notifier = { 1283 .notifier_call = device_event, 1284 }; 1285 1286 static int __init bt_6lowpan_init(void) 1287 { 1288 lowpan_enable_debugfs = debugfs_create_file_unsafe("6lowpan_enable", 1289 0644, bt_debugfs, 1290 NULL, 1291 &lowpan_enable_fops); 1292 lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644, 1293 bt_debugfs, NULL, 1294 &lowpan_control_fops); 1295 1296 return register_netdevice_notifier(&bt_6lowpan_dev_notifier); 1297 } 1298 1299 static void __exit bt_6lowpan_exit(void) 1300 { 1301 debugfs_remove(lowpan_enable_debugfs); 1302 debugfs_remove(lowpan_control_debugfs); 1303 1304 if (listen_chan) { 1305 l2cap_chan_close(listen_chan, 0); 1306 l2cap_chan_put(listen_chan); 1307 } 1308 1309 disconnect_devices(); 1310 1311 unregister_netdevice_notifier(&bt_6lowpan_dev_notifier); 1312 } 1313 1314 module_init(bt_6lowpan_init); 1315 module_exit(bt_6lowpan_exit); 1316 1317 MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>"); 1318 MODULE_DESCRIPTION("Bluetooth 6LoWPAN"); 1319 MODULE_VERSION(VERSION); 1320 MODULE_LICENSE("GPL"); 1321