1 /* 2 Copyright (c) 2013-2014 Intel Corp. 3 4 This program is free software; you can redistribute it and/or modify 5 it under the terms of the GNU General Public License version 2 and 6 only version 2 as published by the Free Software Foundation. 7 8 This program is distributed in the hope that it will be useful, 9 but WITHOUT ANY WARRANTY; without even the implied warranty of 10 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 GNU General Public License for more details. 12 */ 13 14 #include <linux/if_arp.h> 15 #include <linux/netdevice.h> 16 #include <linux/etherdevice.h> 17 #include <linux/module.h> 18 #include <linux/debugfs.h> 19 20 #include <net/ipv6.h> 21 #include <net/ip6_route.h> 22 #include <net/addrconf.h> 23 #include <net/pkt_sched.h> 24 25 #include <net/bluetooth/bluetooth.h> 26 #include <net/bluetooth/hci_core.h> 27 #include <net/bluetooth/l2cap.h> 28 29 #include <net/6lowpan.h> /* for the compression support */ 30 31 #define VERSION "0.1" 32 33 static struct dentry *lowpan_enable_debugfs; 34 static struct dentry *lowpan_control_debugfs; 35 36 #define IFACE_NAME_TEMPLATE "bt%d" 37 38 struct skb_cb { 39 struct in6_addr addr; 40 struct in6_addr gw; 41 struct l2cap_chan *chan; 42 }; 43 #define lowpan_cb(skb) ((struct skb_cb *)((skb)->cb)) 44 45 /* The devices list contains those devices that we are acting 46 * as a proxy. The BT 6LoWPAN device is a virtual device that 47 * connects to the Bluetooth LE device. The real connection to 48 * BT device is done via l2cap layer. There exists one 49 * virtual device / one BT 6LoWPAN network (=hciX device). 50 * The list contains struct lowpan_dev elements. 51 */ 52 static LIST_HEAD(bt_6lowpan_devices); 53 static DEFINE_SPINLOCK(devices_lock); 54 55 static bool enable_6lowpan; 56 57 /* We are listening incoming connections via this channel 58 */ 59 static struct l2cap_chan *listen_chan; 60 61 struct lowpan_peer { 62 struct list_head list; 63 struct rcu_head rcu; 64 struct l2cap_chan *chan; 65 66 /* peer addresses in various formats */ 67 unsigned char lladdr[ETH_ALEN]; 68 struct in6_addr peer_addr; 69 }; 70 71 struct lowpan_btle_dev { 72 struct list_head list; 73 74 struct hci_dev *hdev; 75 struct net_device *netdev; 76 struct list_head peers; 77 atomic_t peer_count; /* number of items in peers list */ 78 79 struct work_struct delete_netdev; 80 struct delayed_work notify_peers; 81 }; 82 83 static inline struct lowpan_btle_dev * 84 lowpan_btle_dev(const struct net_device *netdev) 85 { 86 return (struct lowpan_btle_dev *)lowpan_dev(netdev)->priv; 87 } 88 89 static inline void peer_add(struct lowpan_btle_dev *dev, 90 struct lowpan_peer *peer) 91 { 92 list_add_rcu(&peer->list, &dev->peers); 93 atomic_inc(&dev->peer_count); 94 } 95 96 static inline bool peer_del(struct lowpan_btle_dev *dev, 97 struct lowpan_peer *peer) 98 { 99 list_del_rcu(&peer->list); 100 kfree_rcu(peer, rcu); 101 102 module_put(THIS_MODULE); 103 104 if (atomic_dec_and_test(&dev->peer_count)) { 105 BT_DBG("last peer"); 106 return true; 107 } 108 109 return false; 110 } 111 112 static inline struct lowpan_peer *peer_lookup_ba(struct lowpan_btle_dev *dev, 113 bdaddr_t *ba, __u8 type) 114 { 115 struct lowpan_peer *peer; 116 117 BT_DBG("peers %d addr %pMR type %d", atomic_read(&dev->peer_count), 118 ba, type); 119 120 rcu_read_lock(); 121 122 list_for_each_entry_rcu(peer, &dev->peers, list) { 123 BT_DBG("dst addr %pMR dst type %d", 124 &peer->chan->dst, peer->chan->dst_type); 125 126 if (bacmp(&peer->chan->dst, ba)) 127 continue; 128 129 if (type == peer->chan->dst_type) { 130 rcu_read_unlock(); 131 return peer; 132 } 133 } 134 135 rcu_read_unlock(); 136 137 return NULL; 138 } 139 140 static inline struct lowpan_peer * 141 __peer_lookup_chan(struct lowpan_btle_dev *dev, struct l2cap_chan *chan) 142 { 143 struct lowpan_peer *peer; 144 145 list_for_each_entry_rcu(peer, &dev->peers, list) { 146 if (peer->chan == chan) 147 return peer; 148 } 149 150 return NULL; 151 } 152 153 static inline struct lowpan_peer * 154 __peer_lookup_conn(struct lowpan_btle_dev *dev, struct l2cap_conn *conn) 155 { 156 struct lowpan_peer *peer; 157 158 list_for_each_entry_rcu(peer, &dev->peers, list) { 159 if (peer->chan->conn == conn) 160 return peer; 161 } 162 163 return NULL; 164 } 165 166 static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_btle_dev *dev, 167 struct in6_addr *daddr, 168 struct sk_buff *skb) 169 { 170 struct lowpan_peer *peer; 171 struct in6_addr *nexthop; 172 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb); 173 int count = atomic_read(&dev->peer_count); 174 175 BT_DBG("peers %d addr %pI6c rt %p", count, daddr, rt); 176 177 /* If we have multiple 6lowpan peers, then check where we should 178 * send the packet. If only one peer exists, then we can send the 179 * packet right away. 180 */ 181 if (count == 1) { 182 rcu_read_lock(); 183 peer = list_first_or_null_rcu(&dev->peers, struct lowpan_peer, 184 list); 185 rcu_read_unlock(); 186 return peer; 187 } 188 189 if (!rt) { 190 nexthop = &lowpan_cb(skb)->gw; 191 192 if (ipv6_addr_any(nexthop)) 193 return NULL; 194 } else { 195 nexthop = rt6_nexthop(rt, daddr); 196 197 /* We need to remember the address because it is needed 198 * by bt_xmit() when sending the packet. In bt_xmit(), the 199 * destination routing info is not set. 200 */ 201 memcpy(&lowpan_cb(skb)->gw, nexthop, sizeof(struct in6_addr)); 202 } 203 204 BT_DBG("gw %pI6c", nexthop); 205 206 rcu_read_lock(); 207 208 list_for_each_entry_rcu(peer, &dev->peers, list) { 209 BT_DBG("dst addr %pMR dst type %d ip %pI6c", 210 &peer->chan->dst, peer->chan->dst_type, 211 &peer->peer_addr); 212 213 if (!ipv6_addr_cmp(&peer->peer_addr, nexthop)) { 214 rcu_read_unlock(); 215 return peer; 216 } 217 } 218 219 rcu_read_unlock(); 220 221 return NULL; 222 } 223 224 static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn) 225 { 226 struct lowpan_btle_dev *entry; 227 struct lowpan_peer *peer = NULL; 228 229 rcu_read_lock(); 230 231 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 232 peer = __peer_lookup_conn(entry, conn); 233 if (peer) 234 break; 235 } 236 237 rcu_read_unlock(); 238 239 return peer; 240 } 241 242 static struct lowpan_btle_dev *lookup_dev(struct l2cap_conn *conn) 243 { 244 struct lowpan_btle_dev *entry; 245 struct lowpan_btle_dev *dev = NULL; 246 247 rcu_read_lock(); 248 249 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 250 if (conn->hcon->hdev == entry->hdev) { 251 dev = entry; 252 break; 253 } 254 } 255 256 rcu_read_unlock(); 257 258 return dev; 259 } 260 261 static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev) 262 { 263 struct sk_buff *skb_cp; 264 265 skb_cp = skb_copy(skb, GFP_ATOMIC); 266 if (!skb_cp) 267 return NET_RX_DROP; 268 269 return netif_rx_ni(skb_cp); 270 } 271 272 static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev, 273 struct lowpan_peer *peer) 274 { 275 const u8 *saddr; 276 277 saddr = peer->lladdr; 278 279 return lowpan_header_decompress(skb, netdev, netdev->dev_addr, saddr); 280 } 281 282 static int recv_pkt(struct sk_buff *skb, struct net_device *dev, 283 struct lowpan_peer *peer) 284 { 285 struct sk_buff *local_skb; 286 int ret; 287 288 if (!netif_running(dev)) 289 goto drop; 290 291 if (dev->type != ARPHRD_6LOWPAN || !skb->len) 292 goto drop; 293 294 skb_reset_network_header(skb); 295 296 skb = skb_share_check(skb, GFP_ATOMIC); 297 if (!skb) 298 goto drop; 299 300 /* check that it's our buffer */ 301 if (lowpan_is_ipv6(*skb_network_header(skb))) { 302 /* Pull off the 1-byte of 6lowpan header. */ 303 skb_pull(skb, 1); 304 305 /* Copy the packet so that the IPv6 header is 306 * properly aligned. 307 */ 308 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1, 309 skb_tailroom(skb), GFP_ATOMIC); 310 if (!local_skb) 311 goto drop; 312 313 local_skb->protocol = htons(ETH_P_IPV6); 314 local_skb->pkt_type = PACKET_HOST; 315 local_skb->dev = dev; 316 317 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr)); 318 319 if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) { 320 kfree_skb(local_skb); 321 goto drop; 322 } 323 324 dev->stats.rx_bytes += skb->len; 325 dev->stats.rx_packets++; 326 327 consume_skb(local_skb); 328 consume_skb(skb); 329 } else if (lowpan_is_iphc(*skb_network_header(skb))) { 330 local_skb = skb_clone(skb, GFP_ATOMIC); 331 if (!local_skb) 332 goto drop; 333 334 local_skb->dev = dev; 335 336 ret = iphc_decompress(local_skb, dev, peer); 337 if (ret < 0) { 338 BT_DBG("iphc_decompress failed: %d", ret); 339 kfree_skb(local_skb); 340 goto drop; 341 } 342 343 local_skb->protocol = htons(ETH_P_IPV6); 344 local_skb->pkt_type = PACKET_HOST; 345 346 if (give_skb_to_upper(local_skb, dev) 347 != NET_RX_SUCCESS) { 348 kfree_skb(local_skb); 349 goto drop; 350 } 351 352 dev->stats.rx_bytes += skb->len; 353 dev->stats.rx_packets++; 354 355 consume_skb(local_skb); 356 consume_skb(skb); 357 } else { 358 BT_DBG("unknown packet type"); 359 goto drop; 360 } 361 362 return NET_RX_SUCCESS; 363 364 drop: 365 dev->stats.rx_dropped++; 366 return NET_RX_DROP; 367 } 368 369 /* Packet from BT LE device */ 370 static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) 371 { 372 struct lowpan_btle_dev *dev; 373 struct lowpan_peer *peer; 374 int err; 375 376 peer = lookup_peer(chan->conn); 377 if (!peer) 378 return -ENOENT; 379 380 dev = lookup_dev(chan->conn); 381 if (!dev || !dev->netdev) 382 return -ENOENT; 383 384 err = recv_pkt(skb, dev->netdev, peer); 385 if (err) { 386 BT_DBG("recv pkt %d", err); 387 err = -EAGAIN; 388 } 389 390 return err; 391 } 392 393 static int setup_header(struct sk_buff *skb, struct net_device *netdev, 394 bdaddr_t *peer_addr, u8 *peer_addr_type) 395 { 396 struct in6_addr ipv6_daddr; 397 struct ipv6hdr *hdr; 398 struct lowpan_btle_dev *dev; 399 struct lowpan_peer *peer; 400 u8 *daddr; 401 int err, status = 0; 402 403 hdr = ipv6_hdr(skb); 404 405 dev = lowpan_btle_dev(netdev); 406 407 memcpy(&ipv6_daddr, &hdr->daddr, sizeof(ipv6_daddr)); 408 409 if (ipv6_addr_is_multicast(&ipv6_daddr)) { 410 lowpan_cb(skb)->chan = NULL; 411 daddr = NULL; 412 } else { 413 BT_DBG("dest IP %pI6c", &ipv6_daddr); 414 415 /* The packet might be sent to 6lowpan interface 416 * because of routing (either via default route 417 * or user set route) so get peer according to 418 * the destination address. 419 */ 420 peer = peer_lookup_dst(dev, &ipv6_daddr, skb); 421 if (!peer) { 422 BT_DBG("no such peer"); 423 return -ENOENT; 424 } 425 426 daddr = peer->lladdr; 427 *peer_addr = peer->chan->dst; 428 *peer_addr_type = peer->chan->dst_type; 429 lowpan_cb(skb)->chan = peer->chan; 430 431 status = 1; 432 } 433 434 lowpan_header_compress(skb, netdev, daddr, dev->netdev->dev_addr); 435 436 err = dev_hard_header(skb, netdev, ETH_P_IPV6, NULL, NULL, 0); 437 if (err < 0) 438 return err; 439 440 return status; 441 } 442 443 static int header_create(struct sk_buff *skb, struct net_device *netdev, 444 unsigned short type, const void *_daddr, 445 const void *_saddr, unsigned int len) 446 { 447 if (type != ETH_P_IPV6) 448 return -EINVAL; 449 450 return 0; 451 } 452 453 /* Packet to BT LE device */ 454 static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb, 455 struct net_device *netdev) 456 { 457 struct msghdr msg; 458 struct kvec iv; 459 int err; 460 461 /* Remember the skb so that we can send EAGAIN to the caller if 462 * we run out of credits. 463 */ 464 chan->data = skb; 465 466 iv.iov_base = skb->data; 467 iv.iov_len = skb->len; 468 469 memset(&msg, 0, sizeof(msg)); 470 iov_iter_kvec(&msg.msg_iter, WRITE, &iv, 1, skb->len); 471 472 err = l2cap_chan_send(chan, &msg, skb->len); 473 if (err > 0) { 474 netdev->stats.tx_bytes += err; 475 netdev->stats.tx_packets++; 476 return 0; 477 } 478 479 if (err < 0) 480 netdev->stats.tx_errors++; 481 482 return err; 483 } 484 485 static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev) 486 { 487 struct sk_buff *local_skb; 488 struct lowpan_btle_dev *entry; 489 int err = 0; 490 491 rcu_read_lock(); 492 493 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 494 struct lowpan_peer *pentry; 495 struct lowpan_btle_dev *dev; 496 497 if (entry->netdev != netdev) 498 continue; 499 500 dev = lowpan_btle_dev(entry->netdev); 501 502 list_for_each_entry_rcu(pentry, &dev->peers, list) { 503 int ret; 504 505 local_skb = skb_clone(skb, GFP_ATOMIC); 506 507 BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p", 508 netdev->name, 509 &pentry->chan->dst, pentry->chan->dst_type, 510 &pentry->peer_addr, pentry->chan); 511 ret = send_pkt(pentry->chan, local_skb, netdev); 512 if (ret < 0) 513 err = ret; 514 515 kfree_skb(local_skb); 516 } 517 } 518 519 rcu_read_unlock(); 520 521 return err; 522 } 523 524 static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev) 525 { 526 int err = 0; 527 bdaddr_t addr; 528 u8 addr_type; 529 530 /* We must take a copy of the skb before we modify/replace the ipv6 531 * header as the header could be used elsewhere 532 */ 533 skb = skb_unshare(skb, GFP_ATOMIC); 534 if (!skb) 535 return NET_XMIT_DROP; 536 537 /* Return values from setup_header() 538 * <0 - error, packet is dropped 539 * 0 - this is a multicast packet 540 * 1 - this is unicast packet 541 */ 542 err = setup_header(skb, netdev, &addr, &addr_type); 543 if (err < 0) { 544 kfree_skb(skb); 545 return NET_XMIT_DROP; 546 } 547 548 if (err) { 549 if (lowpan_cb(skb)->chan) { 550 BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p", 551 netdev->name, &addr, addr_type, 552 &lowpan_cb(skb)->addr, lowpan_cb(skb)->chan); 553 err = send_pkt(lowpan_cb(skb)->chan, skb, netdev); 554 } else { 555 err = -ENOENT; 556 } 557 } else { 558 /* We need to send the packet to every device behind this 559 * interface. 560 */ 561 err = send_mcast_pkt(skb, netdev); 562 } 563 564 dev_kfree_skb(skb); 565 566 if (err) 567 BT_DBG("ERROR: xmit failed (%d)", err); 568 569 return err < 0 ? NET_XMIT_DROP : err; 570 } 571 572 static int bt_dev_init(struct net_device *dev) 573 { 574 netdev_lockdep_set_classes(dev); 575 576 return 0; 577 } 578 579 static const struct net_device_ops netdev_ops = { 580 .ndo_init = bt_dev_init, 581 .ndo_start_xmit = bt_xmit, 582 }; 583 584 static struct header_ops header_ops = { 585 .create = header_create, 586 }; 587 588 static void netdev_setup(struct net_device *dev) 589 { 590 dev->hard_header_len = 0; 591 dev->needed_tailroom = 0; 592 dev->flags = IFF_RUNNING | IFF_MULTICAST; 593 dev->watchdog_timeo = 0; 594 dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN; 595 596 dev->netdev_ops = &netdev_ops; 597 dev->header_ops = &header_ops; 598 dev->needs_free_netdev = true; 599 } 600 601 static struct device_type bt_type = { 602 .name = "bluetooth", 603 }; 604 605 static void ifup(struct net_device *netdev) 606 { 607 int err; 608 609 rtnl_lock(); 610 err = dev_open(netdev, NULL); 611 if (err < 0) 612 BT_INFO("iface %s cannot be opened (%d)", netdev->name, err); 613 rtnl_unlock(); 614 } 615 616 static void ifdown(struct net_device *netdev) 617 { 618 rtnl_lock(); 619 dev_close(netdev); 620 rtnl_unlock(); 621 } 622 623 static void do_notify_peers(struct work_struct *work) 624 { 625 struct lowpan_btle_dev *dev = container_of(work, struct lowpan_btle_dev, 626 notify_peers.work); 627 628 netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */ 629 } 630 631 static bool is_bt_6lowpan(struct hci_conn *hcon) 632 { 633 if (hcon->type != LE_LINK) 634 return false; 635 636 if (!enable_6lowpan) 637 return false; 638 639 return true; 640 } 641 642 static struct l2cap_chan *chan_create(void) 643 { 644 struct l2cap_chan *chan; 645 646 chan = l2cap_chan_create(); 647 if (!chan) 648 return NULL; 649 650 l2cap_chan_set_defaults(chan); 651 652 chan->chan_type = L2CAP_CHAN_CONN_ORIENTED; 653 chan->mode = L2CAP_MODE_LE_FLOWCTL; 654 chan->imtu = 1280; 655 656 return chan; 657 } 658 659 static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan, 660 struct lowpan_btle_dev *dev, 661 bool new_netdev) 662 { 663 struct lowpan_peer *peer; 664 665 peer = kzalloc(sizeof(*peer), GFP_ATOMIC); 666 if (!peer) 667 return NULL; 668 669 peer->chan = chan; 670 memset(&peer->peer_addr, 0, sizeof(struct in6_addr)); 671 672 baswap((void *)peer->lladdr, &chan->dst); 673 674 lowpan_iphc_uncompress_eui48_lladdr(&peer->peer_addr, peer->lladdr); 675 676 spin_lock(&devices_lock); 677 INIT_LIST_HEAD(&peer->list); 678 peer_add(dev, peer); 679 spin_unlock(&devices_lock); 680 681 /* Notifying peers about us needs to be done without locks held */ 682 if (new_netdev) 683 INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers); 684 schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100)); 685 686 return peer->chan; 687 } 688 689 static int setup_netdev(struct l2cap_chan *chan, struct lowpan_btle_dev **dev) 690 { 691 struct net_device *netdev; 692 int err = 0; 693 694 netdev = alloc_netdev(LOWPAN_PRIV_SIZE(sizeof(struct lowpan_btle_dev)), 695 IFACE_NAME_TEMPLATE, NET_NAME_UNKNOWN, 696 netdev_setup); 697 if (!netdev) 698 return -ENOMEM; 699 700 netdev->addr_assign_type = NET_ADDR_PERM; 701 baswap((void *)netdev->dev_addr, &chan->src); 702 703 netdev->netdev_ops = &netdev_ops; 704 SET_NETDEV_DEV(netdev, &chan->conn->hcon->hdev->dev); 705 SET_NETDEV_DEVTYPE(netdev, &bt_type); 706 707 *dev = lowpan_btle_dev(netdev); 708 (*dev)->netdev = netdev; 709 (*dev)->hdev = chan->conn->hcon->hdev; 710 INIT_LIST_HEAD(&(*dev)->peers); 711 712 spin_lock(&devices_lock); 713 INIT_LIST_HEAD(&(*dev)->list); 714 list_add_rcu(&(*dev)->list, &bt_6lowpan_devices); 715 spin_unlock(&devices_lock); 716 717 err = lowpan_register_netdev(netdev, LOWPAN_LLTYPE_BTLE); 718 if (err < 0) { 719 BT_INFO("register_netdev failed %d", err); 720 spin_lock(&devices_lock); 721 list_del_rcu(&(*dev)->list); 722 spin_unlock(&devices_lock); 723 free_netdev(netdev); 724 goto out; 725 } 726 727 BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d", 728 netdev->ifindex, &chan->dst, chan->dst_type, 729 &chan->src, chan->src_type); 730 set_bit(__LINK_STATE_PRESENT, &netdev->state); 731 732 return 0; 733 734 out: 735 return err; 736 } 737 738 static inline void chan_ready_cb(struct l2cap_chan *chan) 739 { 740 struct lowpan_btle_dev *dev; 741 bool new_netdev = false; 742 743 dev = lookup_dev(chan->conn); 744 745 BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev); 746 747 if (!dev) { 748 if (setup_netdev(chan, &dev) < 0) { 749 l2cap_chan_del(chan, -ENOENT); 750 return; 751 } 752 new_netdev = true; 753 } 754 755 if (!try_module_get(THIS_MODULE)) 756 return; 757 758 add_peer_chan(chan, dev, new_netdev); 759 ifup(dev->netdev); 760 } 761 762 static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan) 763 { 764 struct l2cap_chan *chan; 765 766 chan = chan_create(); 767 if (!chan) 768 return NULL; 769 770 chan->ops = pchan->ops; 771 772 BT_DBG("chan %p pchan %p", chan, pchan); 773 774 return chan; 775 } 776 777 static void delete_netdev(struct work_struct *work) 778 { 779 struct lowpan_btle_dev *entry = container_of(work, 780 struct lowpan_btle_dev, 781 delete_netdev); 782 783 lowpan_unregister_netdev(entry->netdev); 784 785 /* The entry pointer is deleted by the netdev destructor. */ 786 } 787 788 static void chan_close_cb(struct l2cap_chan *chan) 789 { 790 struct lowpan_btle_dev *entry; 791 struct lowpan_btle_dev *dev = NULL; 792 struct lowpan_peer *peer; 793 int err = -ENOENT; 794 bool last = false, remove = true; 795 796 BT_DBG("chan %p conn %p", chan, chan->conn); 797 798 if (chan->conn && chan->conn->hcon) { 799 if (!is_bt_6lowpan(chan->conn->hcon)) 800 return; 801 802 /* If conn is set, then the netdev is also there and we should 803 * not remove it. 804 */ 805 remove = false; 806 } 807 808 spin_lock(&devices_lock); 809 810 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 811 dev = lowpan_btle_dev(entry->netdev); 812 peer = __peer_lookup_chan(dev, chan); 813 if (peer) { 814 last = peer_del(dev, peer); 815 err = 0; 816 817 BT_DBG("dev %p removing %speer %p", dev, 818 last ? "last " : "1 ", peer); 819 BT_DBG("chan %p orig refcnt %d", chan, 820 kref_read(&chan->kref)); 821 822 l2cap_chan_put(chan); 823 break; 824 } 825 } 826 827 if (!err && last && dev && !atomic_read(&dev->peer_count)) { 828 spin_unlock(&devices_lock); 829 830 cancel_delayed_work_sync(&dev->notify_peers); 831 832 ifdown(dev->netdev); 833 834 if (remove) { 835 INIT_WORK(&entry->delete_netdev, delete_netdev); 836 schedule_work(&entry->delete_netdev); 837 } 838 } else { 839 spin_unlock(&devices_lock); 840 } 841 842 return; 843 } 844 845 static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err) 846 { 847 BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn, 848 state_to_string(state), err); 849 } 850 851 static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan, 852 unsigned long hdr_len, 853 unsigned long len, int nb) 854 { 855 /* Note that we must allocate using GFP_ATOMIC here as 856 * this function is called originally from netdev hard xmit 857 * function in atomic context. 858 */ 859 return bt_skb_alloc(hdr_len + len, GFP_ATOMIC); 860 } 861 862 static void chan_suspend_cb(struct l2cap_chan *chan) 863 { 864 struct lowpan_btle_dev *dev; 865 866 BT_DBG("chan %p suspend", chan); 867 868 dev = lookup_dev(chan->conn); 869 if (!dev || !dev->netdev) 870 return; 871 872 netif_stop_queue(dev->netdev); 873 } 874 875 static void chan_resume_cb(struct l2cap_chan *chan) 876 { 877 struct lowpan_btle_dev *dev; 878 879 BT_DBG("chan %p resume", chan); 880 881 dev = lookup_dev(chan->conn); 882 if (!dev || !dev->netdev) 883 return; 884 885 netif_wake_queue(dev->netdev); 886 } 887 888 static long chan_get_sndtimeo_cb(struct l2cap_chan *chan) 889 { 890 return L2CAP_CONN_TIMEOUT; 891 } 892 893 static const struct l2cap_ops bt_6lowpan_chan_ops = { 894 .name = "L2CAP 6LoWPAN channel", 895 .new_connection = chan_new_conn_cb, 896 .recv = chan_recv_cb, 897 .close = chan_close_cb, 898 .state_change = chan_state_change_cb, 899 .ready = chan_ready_cb, 900 .resume = chan_resume_cb, 901 .suspend = chan_suspend_cb, 902 .get_sndtimeo = chan_get_sndtimeo_cb, 903 .alloc_skb = chan_alloc_skb_cb, 904 905 .teardown = l2cap_chan_no_teardown, 906 .defer = l2cap_chan_no_defer, 907 .set_shutdown = l2cap_chan_no_set_shutdown, 908 }; 909 910 static inline __u8 bdaddr_type(__u8 type) 911 { 912 if (type == ADDR_LE_DEV_PUBLIC) 913 return BDADDR_LE_PUBLIC; 914 else 915 return BDADDR_LE_RANDOM; 916 } 917 918 static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type) 919 { 920 struct l2cap_chan *chan; 921 int err; 922 923 chan = chan_create(); 924 if (!chan) 925 return -EINVAL; 926 927 chan->ops = &bt_6lowpan_chan_ops; 928 929 err = l2cap_chan_connect(chan, cpu_to_le16(L2CAP_PSM_IPSP), 0, 930 addr, dst_type); 931 932 BT_DBG("chan %p err %d", chan, err); 933 if (err < 0) 934 l2cap_chan_put(chan); 935 936 return err; 937 } 938 939 static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type) 940 { 941 struct lowpan_peer *peer; 942 943 BT_DBG("conn %p dst type %d", conn, dst_type); 944 945 peer = lookup_peer(conn); 946 if (!peer) 947 return -ENOENT; 948 949 BT_DBG("peer %p chan %p", peer, peer->chan); 950 951 l2cap_chan_close(peer->chan, ENOENT); 952 953 return 0; 954 } 955 956 static struct l2cap_chan *bt_6lowpan_listen(void) 957 { 958 bdaddr_t *addr = BDADDR_ANY; 959 struct l2cap_chan *chan; 960 int err; 961 962 if (!enable_6lowpan) 963 return NULL; 964 965 chan = chan_create(); 966 if (!chan) 967 return NULL; 968 969 chan->ops = &bt_6lowpan_chan_ops; 970 chan->state = BT_LISTEN; 971 chan->src_type = BDADDR_LE_PUBLIC; 972 973 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT); 974 975 BT_DBG("chan %p src type %d", chan, chan->src_type); 976 977 err = l2cap_add_psm(chan, addr, cpu_to_le16(L2CAP_PSM_IPSP)); 978 if (err) { 979 l2cap_chan_put(chan); 980 BT_ERR("psm cannot be added err %d", err); 981 return NULL; 982 } 983 984 return chan; 985 } 986 987 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type, 988 struct l2cap_conn **conn) 989 { 990 struct hci_conn *hcon; 991 struct hci_dev *hdev; 992 int n; 993 994 n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu", 995 &addr->b[5], &addr->b[4], &addr->b[3], 996 &addr->b[2], &addr->b[1], &addr->b[0], 997 addr_type); 998 999 if (n < 7) 1000 return -EINVAL; 1001 1002 /* The LE_PUBLIC address type is ignored because of BDADDR_ANY */ 1003 hdev = hci_get_route(addr, BDADDR_ANY, BDADDR_LE_PUBLIC); 1004 if (!hdev) 1005 return -ENOENT; 1006 1007 hci_dev_lock(hdev); 1008 hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type); 1009 hci_dev_unlock(hdev); 1010 1011 if (!hcon) 1012 return -ENOENT; 1013 1014 *conn = (struct l2cap_conn *)hcon->l2cap_data; 1015 1016 BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type); 1017 1018 return 0; 1019 } 1020 1021 static void disconnect_all_peers(void) 1022 { 1023 struct lowpan_btle_dev *entry; 1024 struct lowpan_peer *peer, *tmp_peer, *new_peer; 1025 struct list_head peers; 1026 1027 INIT_LIST_HEAD(&peers); 1028 1029 /* We make a separate list of peers as the close_cb() will 1030 * modify the device peers list so it is better not to mess 1031 * with the same list at the same time. 1032 */ 1033 1034 rcu_read_lock(); 1035 1036 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 1037 list_for_each_entry_rcu(peer, &entry->peers, list) { 1038 new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC); 1039 if (!new_peer) 1040 break; 1041 1042 new_peer->chan = peer->chan; 1043 INIT_LIST_HEAD(&new_peer->list); 1044 1045 list_add(&new_peer->list, &peers); 1046 } 1047 } 1048 1049 rcu_read_unlock(); 1050 1051 spin_lock(&devices_lock); 1052 list_for_each_entry_safe(peer, tmp_peer, &peers, list) { 1053 l2cap_chan_close(peer->chan, ENOENT); 1054 1055 list_del_rcu(&peer->list); 1056 kfree_rcu(peer, rcu); 1057 } 1058 spin_unlock(&devices_lock); 1059 } 1060 1061 struct set_enable { 1062 struct work_struct work; 1063 bool flag; 1064 }; 1065 1066 static void do_enable_set(struct work_struct *work) 1067 { 1068 struct set_enable *set_enable = container_of(work, 1069 struct set_enable, work); 1070 1071 if (!set_enable->flag || enable_6lowpan != set_enable->flag) 1072 /* Disconnect existing connections if 6lowpan is 1073 * disabled 1074 */ 1075 disconnect_all_peers(); 1076 1077 enable_6lowpan = set_enable->flag; 1078 1079 if (listen_chan) { 1080 l2cap_chan_close(listen_chan, 0); 1081 l2cap_chan_put(listen_chan); 1082 } 1083 1084 listen_chan = bt_6lowpan_listen(); 1085 1086 kfree(set_enable); 1087 } 1088 1089 static int lowpan_enable_set(void *data, u64 val) 1090 { 1091 struct set_enable *set_enable; 1092 1093 set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL); 1094 if (!set_enable) 1095 return -ENOMEM; 1096 1097 set_enable->flag = !!val; 1098 INIT_WORK(&set_enable->work, do_enable_set); 1099 1100 schedule_work(&set_enable->work); 1101 1102 return 0; 1103 } 1104 1105 static int lowpan_enable_get(void *data, u64 *val) 1106 { 1107 *val = enable_6lowpan; 1108 return 0; 1109 } 1110 1111 DEFINE_DEBUGFS_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get, 1112 lowpan_enable_set, "%llu\n"); 1113 1114 static ssize_t lowpan_control_write(struct file *fp, 1115 const char __user *user_buffer, 1116 size_t count, 1117 loff_t *position) 1118 { 1119 char buf[32]; 1120 size_t buf_size = min(count, sizeof(buf) - 1); 1121 int ret; 1122 bdaddr_t addr; 1123 u8 addr_type; 1124 struct l2cap_conn *conn = NULL; 1125 1126 if (copy_from_user(buf, user_buffer, buf_size)) 1127 return -EFAULT; 1128 1129 buf[buf_size] = '\0'; 1130 1131 if (memcmp(buf, "connect ", 8) == 0) { 1132 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn); 1133 if (ret == -EINVAL) 1134 return ret; 1135 1136 if (listen_chan) { 1137 l2cap_chan_close(listen_chan, 0); 1138 l2cap_chan_put(listen_chan); 1139 listen_chan = NULL; 1140 } 1141 1142 if (conn) { 1143 struct lowpan_peer *peer; 1144 1145 if (!is_bt_6lowpan(conn->hcon)) 1146 return -EINVAL; 1147 1148 peer = lookup_peer(conn); 1149 if (peer) { 1150 BT_DBG("6LoWPAN connection already exists"); 1151 return -EALREADY; 1152 } 1153 1154 BT_DBG("conn %p dst %pMR type %d user %d", conn, 1155 &conn->hcon->dst, conn->hcon->dst_type, 1156 addr_type); 1157 } 1158 1159 ret = bt_6lowpan_connect(&addr, addr_type); 1160 if (ret < 0) 1161 return ret; 1162 1163 return count; 1164 } 1165 1166 if (memcmp(buf, "disconnect ", 11) == 0) { 1167 ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn); 1168 if (ret < 0) 1169 return ret; 1170 1171 ret = bt_6lowpan_disconnect(conn, addr_type); 1172 if (ret < 0) 1173 return ret; 1174 1175 return count; 1176 } 1177 1178 return count; 1179 } 1180 1181 static int lowpan_control_show(struct seq_file *f, void *ptr) 1182 { 1183 struct lowpan_btle_dev *entry; 1184 struct lowpan_peer *peer; 1185 1186 spin_lock(&devices_lock); 1187 1188 list_for_each_entry(entry, &bt_6lowpan_devices, list) { 1189 list_for_each_entry(peer, &entry->peers, list) 1190 seq_printf(f, "%pMR (type %u)\n", 1191 &peer->chan->dst, peer->chan->dst_type); 1192 } 1193 1194 spin_unlock(&devices_lock); 1195 1196 return 0; 1197 } 1198 1199 static int lowpan_control_open(struct inode *inode, struct file *file) 1200 { 1201 return single_open(file, lowpan_control_show, inode->i_private); 1202 } 1203 1204 static const struct file_operations lowpan_control_fops = { 1205 .open = lowpan_control_open, 1206 .read = seq_read, 1207 .write = lowpan_control_write, 1208 .llseek = seq_lseek, 1209 .release = single_release, 1210 }; 1211 1212 static void disconnect_devices(void) 1213 { 1214 struct lowpan_btle_dev *entry, *tmp, *new_dev; 1215 struct list_head devices; 1216 1217 INIT_LIST_HEAD(&devices); 1218 1219 /* We make a separate list of devices because the unregister_netdev() 1220 * will call device_event() which will also want to modify the same 1221 * devices list. 1222 */ 1223 1224 rcu_read_lock(); 1225 1226 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 1227 new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC); 1228 if (!new_dev) 1229 break; 1230 1231 new_dev->netdev = entry->netdev; 1232 INIT_LIST_HEAD(&new_dev->list); 1233 1234 list_add_rcu(&new_dev->list, &devices); 1235 } 1236 1237 rcu_read_unlock(); 1238 1239 list_for_each_entry_safe(entry, tmp, &devices, list) { 1240 ifdown(entry->netdev); 1241 BT_DBG("Unregistering netdev %s %p", 1242 entry->netdev->name, entry->netdev); 1243 lowpan_unregister_netdev(entry->netdev); 1244 kfree(entry); 1245 } 1246 } 1247 1248 static int device_event(struct notifier_block *unused, 1249 unsigned long event, void *ptr) 1250 { 1251 struct net_device *netdev = netdev_notifier_info_to_dev(ptr); 1252 struct lowpan_btle_dev *entry; 1253 1254 if (netdev->type != ARPHRD_6LOWPAN) 1255 return NOTIFY_DONE; 1256 1257 switch (event) { 1258 case NETDEV_UNREGISTER: 1259 spin_lock(&devices_lock); 1260 list_for_each_entry(entry, &bt_6lowpan_devices, list) { 1261 if (entry->netdev == netdev) { 1262 BT_DBG("Unregistered netdev %s %p", 1263 netdev->name, netdev); 1264 list_del(&entry->list); 1265 break; 1266 } 1267 } 1268 spin_unlock(&devices_lock); 1269 break; 1270 } 1271 1272 return NOTIFY_DONE; 1273 } 1274 1275 static struct notifier_block bt_6lowpan_dev_notifier = { 1276 .notifier_call = device_event, 1277 }; 1278 1279 static int __init bt_6lowpan_init(void) 1280 { 1281 lowpan_enable_debugfs = debugfs_create_file_unsafe("6lowpan_enable", 1282 0644, bt_debugfs, 1283 NULL, 1284 &lowpan_enable_fops); 1285 lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644, 1286 bt_debugfs, NULL, 1287 &lowpan_control_fops); 1288 1289 return register_netdevice_notifier(&bt_6lowpan_dev_notifier); 1290 } 1291 1292 static void __exit bt_6lowpan_exit(void) 1293 { 1294 debugfs_remove(lowpan_enable_debugfs); 1295 debugfs_remove(lowpan_control_debugfs); 1296 1297 if (listen_chan) { 1298 l2cap_chan_close(listen_chan, 0); 1299 l2cap_chan_put(listen_chan); 1300 } 1301 1302 disconnect_devices(); 1303 1304 unregister_netdevice_notifier(&bt_6lowpan_dev_notifier); 1305 } 1306 1307 module_init(bt_6lowpan_init); 1308 module_exit(bt_6lowpan_exit); 1309 1310 MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>"); 1311 MODULE_DESCRIPTION("Bluetooth 6LoWPAN"); 1312 MODULE_VERSION(VERSION); 1313 MODULE_LICENSE("GPL"); 1314