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 struct lowpan_btle_dev *dev; 277 278 dev = lowpan_btle_dev(netdev); 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 | ITER_KVEC, &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 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); 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 int err; 622 623 rtnl_lock(); 624 err = dev_close(netdev); 625 if (err < 0) 626 BT_INFO("iface %s cannot be closed (%d)", netdev->name, err); 627 rtnl_unlock(); 628 } 629 630 static void do_notify_peers(struct work_struct *work) 631 { 632 struct lowpan_btle_dev *dev = container_of(work, struct lowpan_btle_dev, 633 notify_peers.work); 634 635 netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */ 636 } 637 638 static bool is_bt_6lowpan(struct hci_conn *hcon) 639 { 640 if (hcon->type != LE_LINK) 641 return false; 642 643 if (!enable_6lowpan) 644 return false; 645 646 return true; 647 } 648 649 static struct l2cap_chan *chan_create(void) 650 { 651 struct l2cap_chan *chan; 652 653 chan = l2cap_chan_create(); 654 if (!chan) 655 return NULL; 656 657 l2cap_chan_set_defaults(chan); 658 659 chan->chan_type = L2CAP_CHAN_CONN_ORIENTED; 660 chan->mode = L2CAP_MODE_LE_FLOWCTL; 661 chan->imtu = 1280; 662 663 return chan; 664 } 665 666 static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan, 667 struct lowpan_btle_dev *dev, 668 bool new_netdev) 669 { 670 struct lowpan_peer *peer; 671 672 peer = kzalloc(sizeof(*peer), GFP_ATOMIC); 673 if (!peer) 674 return NULL; 675 676 peer->chan = chan; 677 memset(&peer->peer_addr, 0, sizeof(struct in6_addr)); 678 679 baswap((void *)peer->lladdr, &chan->dst); 680 681 lowpan_iphc_uncompress_eui48_lladdr(&peer->peer_addr, peer->lladdr); 682 683 spin_lock(&devices_lock); 684 INIT_LIST_HEAD(&peer->list); 685 peer_add(dev, peer); 686 spin_unlock(&devices_lock); 687 688 /* Notifying peers about us needs to be done without locks held */ 689 if (new_netdev) 690 INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers); 691 schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100)); 692 693 return peer->chan; 694 } 695 696 static int setup_netdev(struct l2cap_chan *chan, struct lowpan_btle_dev **dev) 697 { 698 struct net_device *netdev; 699 int err = 0; 700 701 netdev = alloc_netdev(LOWPAN_PRIV_SIZE(sizeof(struct lowpan_btle_dev)), 702 IFACE_NAME_TEMPLATE, NET_NAME_UNKNOWN, 703 netdev_setup); 704 if (!netdev) 705 return -ENOMEM; 706 707 netdev->addr_assign_type = NET_ADDR_PERM; 708 baswap((void *)netdev->dev_addr, &chan->src); 709 710 netdev->netdev_ops = &netdev_ops; 711 SET_NETDEV_DEV(netdev, &chan->conn->hcon->hdev->dev); 712 SET_NETDEV_DEVTYPE(netdev, &bt_type); 713 714 *dev = lowpan_btle_dev(netdev); 715 (*dev)->netdev = netdev; 716 (*dev)->hdev = chan->conn->hcon->hdev; 717 INIT_LIST_HEAD(&(*dev)->peers); 718 719 spin_lock(&devices_lock); 720 INIT_LIST_HEAD(&(*dev)->list); 721 list_add_rcu(&(*dev)->list, &bt_6lowpan_devices); 722 spin_unlock(&devices_lock); 723 724 err = lowpan_register_netdev(netdev, LOWPAN_LLTYPE_BTLE); 725 if (err < 0) { 726 BT_INFO("register_netdev failed %d", err); 727 spin_lock(&devices_lock); 728 list_del_rcu(&(*dev)->list); 729 spin_unlock(&devices_lock); 730 free_netdev(netdev); 731 goto out; 732 } 733 734 BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d", 735 netdev->ifindex, &chan->dst, chan->dst_type, 736 &chan->src, chan->src_type); 737 set_bit(__LINK_STATE_PRESENT, &netdev->state); 738 739 return 0; 740 741 out: 742 return err; 743 } 744 745 static inline void chan_ready_cb(struct l2cap_chan *chan) 746 { 747 struct lowpan_btle_dev *dev; 748 bool new_netdev = false; 749 750 dev = lookup_dev(chan->conn); 751 752 BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev); 753 754 if (!dev) { 755 if (setup_netdev(chan, &dev) < 0) { 756 l2cap_chan_del(chan, -ENOENT); 757 return; 758 } 759 new_netdev = true; 760 } 761 762 if (!try_module_get(THIS_MODULE)) 763 return; 764 765 add_peer_chan(chan, dev, new_netdev); 766 ifup(dev->netdev); 767 } 768 769 static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan) 770 { 771 struct l2cap_chan *chan; 772 773 chan = chan_create(); 774 if (!chan) 775 return NULL; 776 777 chan->ops = pchan->ops; 778 779 BT_DBG("chan %p pchan %p", chan, pchan); 780 781 return chan; 782 } 783 784 static void delete_netdev(struct work_struct *work) 785 { 786 struct lowpan_btle_dev *entry = container_of(work, 787 struct lowpan_btle_dev, 788 delete_netdev); 789 790 lowpan_unregister_netdev(entry->netdev); 791 792 /* The entry pointer is deleted by the netdev destructor. */ 793 } 794 795 static void chan_close_cb(struct l2cap_chan *chan) 796 { 797 struct lowpan_btle_dev *entry; 798 struct lowpan_btle_dev *dev = NULL; 799 struct lowpan_peer *peer; 800 int err = -ENOENT; 801 bool last = false, remove = true; 802 803 BT_DBG("chan %p conn %p", chan, chan->conn); 804 805 if (chan->conn && chan->conn->hcon) { 806 if (!is_bt_6lowpan(chan->conn->hcon)) 807 return; 808 809 /* If conn is set, then the netdev is also there and we should 810 * not remove it. 811 */ 812 remove = false; 813 } 814 815 spin_lock(&devices_lock); 816 817 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 818 dev = lowpan_btle_dev(entry->netdev); 819 peer = __peer_lookup_chan(dev, chan); 820 if (peer) { 821 last = peer_del(dev, peer); 822 err = 0; 823 824 BT_DBG("dev %p removing %speer %p", dev, 825 last ? "last " : "1 ", peer); 826 BT_DBG("chan %p orig refcnt %d", chan, 827 kref_read(&chan->kref)); 828 829 l2cap_chan_put(chan); 830 break; 831 } 832 } 833 834 if (!err && last && dev && !atomic_read(&dev->peer_count)) { 835 spin_unlock(&devices_lock); 836 837 cancel_delayed_work_sync(&dev->notify_peers); 838 839 ifdown(dev->netdev); 840 841 if (remove) { 842 INIT_WORK(&entry->delete_netdev, delete_netdev); 843 schedule_work(&entry->delete_netdev); 844 } 845 } else { 846 spin_unlock(&devices_lock); 847 } 848 849 return; 850 } 851 852 static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err) 853 { 854 BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn, 855 state_to_string(state), err); 856 } 857 858 static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan, 859 unsigned long hdr_len, 860 unsigned long len, int nb) 861 { 862 /* Note that we must allocate using GFP_ATOMIC here as 863 * this function is called originally from netdev hard xmit 864 * function in atomic context. 865 */ 866 return bt_skb_alloc(hdr_len + len, GFP_ATOMIC); 867 } 868 869 static void chan_suspend_cb(struct l2cap_chan *chan) 870 { 871 struct lowpan_btle_dev *dev; 872 873 BT_DBG("chan %p suspend", chan); 874 875 dev = lookup_dev(chan->conn); 876 if (!dev || !dev->netdev) 877 return; 878 879 netif_stop_queue(dev->netdev); 880 } 881 882 static void chan_resume_cb(struct l2cap_chan *chan) 883 { 884 struct lowpan_btle_dev *dev; 885 886 BT_DBG("chan %p resume", chan); 887 888 dev = lookup_dev(chan->conn); 889 if (!dev || !dev->netdev) 890 return; 891 892 netif_wake_queue(dev->netdev); 893 } 894 895 static long chan_get_sndtimeo_cb(struct l2cap_chan *chan) 896 { 897 return L2CAP_CONN_TIMEOUT; 898 } 899 900 static const struct l2cap_ops bt_6lowpan_chan_ops = { 901 .name = "L2CAP 6LoWPAN channel", 902 .new_connection = chan_new_conn_cb, 903 .recv = chan_recv_cb, 904 .close = chan_close_cb, 905 .state_change = chan_state_change_cb, 906 .ready = chan_ready_cb, 907 .resume = chan_resume_cb, 908 .suspend = chan_suspend_cb, 909 .get_sndtimeo = chan_get_sndtimeo_cb, 910 .alloc_skb = chan_alloc_skb_cb, 911 912 .teardown = l2cap_chan_no_teardown, 913 .defer = l2cap_chan_no_defer, 914 .set_shutdown = l2cap_chan_no_set_shutdown, 915 }; 916 917 static inline __u8 bdaddr_type(__u8 type) 918 { 919 if (type == ADDR_LE_DEV_PUBLIC) 920 return BDADDR_LE_PUBLIC; 921 else 922 return BDADDR_LE_RANDOM; 923 } 924 925 static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type) 926 { 927 struct l2cap_chan *chan; 928 int err; 929 930 chan = chan_create(); 931 if (!chan) 932 return -EINVAL; 933 934 chan->ops = &bt_6lowpan_chan_ops; 935 936 err = l2cap_chan_connect(chan, cpu_to_le16(L2CAP_PSM_IPSP), 0, 937 addr, dst_type); 938 939 BT_DBG("chan %p err %d", chan, err); 940 if (err < 0) 941 l2cap_chan_put(chan); 942 943 return err; 944 } 945 946 static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type) 947 { 948 struct lowpan_peer *peer; 949 950 BT_DBG("conn %p dst type %d", conn, dst_type); 951 952 peer = lookup_peer(conn); 953 if (!peer) 954 return -ENOENT; 955 956 BT_DBG("peer %p chan %p", peer, peer->chan); 957 958 l2cap_chan_close(peer->chan, ENOENT); 959 960 return 0; 961 } 962 963 static struct l2cap_chan *bt_6lowpan_listen(void) 964 { 965 bdaddr_t *addr = BDADDR_ANY; 966 struct l2cap_chan *chan; 967 int err; 968 969 if (!enable_6lowpan) 970 return NULL; 971 972 chan = chan_create(); 973 if (!chan) 974 return NULL; 975 976 chan->ops = &bt_6lowpan_chan_ops; 977 chan->state = BT_LISTEN; 978 chan->src_type = BDADDR_LE_PUBLIC; 979 980 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT); 981 982 BT_DBG("chan %p src type %d", chan, chan->src_type); 983 984 err = l2cap_add_psm(chan, addr, cpu_to_le16(L2CAP_PSM_IPSP)); 985 if (err) { 986 l2cap_chan_put(chan); 987 BT_ERR("psm cannot be added err %d", err); 988 return NULL; 989 } 990 991 return chan; 992 } 993 994 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type, 995 struct l2cap_conn **conn) 996 { 997 struct hci_conn *hcon; 998 struct hci_dev *hdev; 999 int n; 1000 1001 n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu", 1002 &addr->b[5], &addr->b[4], &addr->b[3], 1003 &addr->b[2], &addr->b[1], &addr->b[0], 1004 addr_type); 1005 1006 if (n < 7) 1007 return -EINVAL; 1008 1009 /* The LE_PUBLIC address type is ignored because of BDADDR_ANY */ 1010 hdev = hci_get_route(addr, BDADDR_ANY, BDADDR_LE_PUBLIC); 1011 if (!hdev) 1012 return -ENOENT; 1013 1014 hci_dev_lock(hdev); 1015 hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type); 1016 hci_dev_unlock(hdev); 1017 1018 if (!hcon) 1019 return -ENOENT; 1020 1021 *conn = (struct l2cap_conn *)hcon->l2cap_data; 1022 1023 BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type); 1024 1025 return 0; 1026 } 1027 1028 static void disconnect_all_peers(void) 1029 { 1030 struct lowpan_btle_dev *entry; 1031 struct lowpan_peer *peer, *tmp_peer, *new_peer; 1032 struct list_head peers; 1033 1034 INIT_LIST_HEAD(&peers); 1035 1036 /* We make a separate list of peers as the close_cb() will 1037 * modify the device peers list so it is better not to mess 1038 * with the same list at the same time. 1039 */ 1040 1041 rcu_read_lock(); 1042 1043 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 1044 list_for_each_entry_rcu(peer, &entry->peers, list) { 1045 new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC); 1046 if (!new_peer) 1047 break; 1048 1049 new_peer->chan = peer->chan; 1050 INIT_LIST_HEAD(&new_peer->list); 1051 1052 list_add(&new_peer->list, &peers); 1053 } 1054 } 1055 1056 rcu_read_unlock(); 1057 1058 spin_lock(&devices_lock); 1059 list_for_each_entry_safe(peer, tmp_peer, &peers, list) { 1060 l2cap_chan_close(peer->chan, ENOENT); 1061 1062 list_del_rcu(&peer->list); 1063 kfree_rcu(peer, rcu); 1064 } 1065 spin_unlock(&devices_lock); 1066 } 1067 1068 struct set_enable { 1069 struct work_struct work; 1070 bool flag; 1071 }; 1072 1073 static void do_enable_set(struct work_struct *work) 1074 { 1075 struct set_enable *set_enable = container_of(work, 1076 struct set_enable, work); 1077 1078 if (!set_enable->flag || enable_6lowpan != set_enable->flag) 1079 /* Disconnect existing connections if 6lowpan is 1080 * disabled 1081 */ 1082 disconnect_all_peers(); 1083 1084 enable_6lowpan = set_enable->flag; 1085 1086 if (listen_chan) { 1087 l2cap_chan_close(listen_chan, 0); 1088 l2cap_chan_put(listen_chan); 1089 } 1090 1091 listen_chan = bt_6lowpan_listen(); 1092 1093 kfree(set_enable); 1094 } 1095 1096 static int lowpan_enable_set(void *data, u64 val) 1097 { 1098 struct set_enable *set_enable; 1099 1100 set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL); 1101 if (!set_enable) 1102 return -ENOMEM; 1103 1104 set_enable->flag = !!val; 1105 INIT_WORK(&set_enable->work, do_enable_set); 1106 1107 schedule_work(&set_enable->work); 1108 1109 return 0; 1110 } 1111 1112 static int lowpan_enable_get(void *data, u64 *val) 1113 { 1114 *val = enable_6lowpan; 1115 return 0; 1116 } 1117 1118 DEFINE_SIMPLE_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get, 1119 lowpan_enable_set, "%llu\n"); 1120 1121 static ssize_t lowpan_control_write(struct file *fp, 1122 const char __user *user_buffer, 1123 size_t count, 1124 loff_t *position) 1125 { 1126 char buf[32]; 1127 size_t buf_size = min(count, sizeof(buf) - 1); 1128 int ret; 1129 bdaddr_t addr; 1130 u8 addr_type; 1131 struct l2cap_conn *conn = NULL; 1132 1133 if (copy_from_user(buf, user_buffer, buf_size)) 1134 return -EFAULT; 1135 1136 buf[buf_size] = '\0'; 1137 1138 if (memcmp(buf, "connect ", 8) == 0) { 1139 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn); 1140 if (ret == -EINVAL) 1141 return ret; 1142 1143 if (listen_chan) { 1144 l2cap_chan_close(listen_chan, 0); 1145 l2cap_chan_put(listen_chan); 1146 listen_chan = NULL; 1147 } 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("6lowpan_enable", 0644, 1289 bt_debugfs, NULL, 1290 &lowpan_enable_fops); 1291 lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644, 1292 bt_debugfs, NULL, 1293 &lowpan_control_fops); 1294 1295 return register_netdevice_notifier(&bt_6lowpan_dev_notifier); 1296 } 1297 1298 static void __exit bt_6lowpan_exit(void) 1299 { 1300 debugfs_remove(lowpan_enable_debugfs); 1301 debugfs_remove(lowpan_control_debugfs); 1302 1303 if (listen_chan) { 1304 l2cap_chan_close(listen_chan, 0); 1305 l2cap_chan_put(listen_chan); 1306 } 1307 1308 disconnect_devices(); 1309 1310 unregister_netdevice_notifier(&bt_6lowpan_dev_notifier); 1311 } 1312 1313 module_init(bt_6lowpan_init); 1314 module_exit(bt_6lowpan_exit); 1315 1316 MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>"); 1317 MODULE_DESCRIPTION("Bluetooth 6LoWPAN"); 1318 MODULE_VERSION(VERSION); 1319 MODULE_LICENSE("GPL"); 1320