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 24 #include <net/bluetooth/bluetooth.h> 25 #include <net/bluetooth/hci_core.h> 26 #include <net/bluetooth/l2cap.h> 27 28 #include <net/6lowpan.h> /* for the compression support */ 29 30 #define VERSION "0.1" 31 32 static struct dentry *lowpan_enable_debugfs; 33 static struct dentry *lowpan_control_debugfs; 34 35 #define IFACE_NAME_TEMPLATE "bt%d" 36 37 struct skb_cb { 38 struct in6_addr addr; 39 struct in6_addr gw; 40 struct l2cap_chan *chan; 41 int status; 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 eui64_addr[EUI64_ADDR_LEN]; 68 struct in6_addr peer_addr; 69 }; 70 71 struct lowpan_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_dev *lowpan_dev(const struct net_device *netdev) 84 { 85 return (struct lowpan_dev *)lowpan_priv(netdev)->priv; 86 } 87 88 static inline void peer_add(struct lowpan_dev *dev, struct lowpan_peer *peer) 89 { 90 list_add_rcu(&peer->list, &dev->peers); 91 atomic_inc(&dev->peer_count); 92 } 93 94 static inline bool peer_del(struct lowpan_dev *dev, struct lowpan_peer *peer) 95 { 96 list_del_rcu(&peer->list); 97 kfree_rcu(peer, rcu); 98 99 module_put(THIS_MODULE); 100 101 if (atomic_dec_and_test(&dev->peer_count)) { 102 BT_DBG("last peer"); 103 return true; 104 } 105 106 return false; 107 } 108 109 static inline struct lowpan_peer *peer_lookup_ba(struct lowpan_dev *dev, 110 bdaddr_t *ba, __u8 type) 111 { 112 struct lowpan_peer *peer; 113 114 BT_DBG("peers %d addr %pMR type %d", atomic_read(&dev->peer_count), 115 ba, type); 116 117 rcu_read_lock(); 118 119 list_for_each_entry_rcu(peer, &dev->peers, list) { 120 BT_DBG("dst addr %pMR dst type %d", 121 &peer->chan->dst, peer->chan->dst_type); 122 123 if (bacmp(&peer->chan->dst, ba)) 124 continue; 125 126 if (type == peer->chan->dst_type) { 127 rcu_read_unlock(); 128 return peer; 129 } 130 } 131 132 rcu_read_unlock(); 133 134 return NULL; 135 } 136 137 static inline struct lowpan_peer *__peer_lookup_chan(struct lowpan_dev *dev, 138 struct l2cap_chan *chan) 139 { 140 struct lowpan_peer *peer; 141 142 list_for_each_entry_rcu(peer, &dev->peers, list) { 143 if (peer->chan == chan) 144 return peer; 145 } 146 147 return NULL; 148 } 149 150 static inline struct lowpan_peer *__peer_lookup_conn(struct lowpan_dev *dev, 151 struct l2cap_conn *conn) 152 { 153 struct lowpan_peer *peer; 154 155 list_for_each_entry_rcu(peer, &dev->peers, list) { 156 if (peer->chan->conn == conn) 157 return peer; 158 } 159 160 return NULL; 161 } 162 163 static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_dev *dev, 164 struct in6_addr *daddr, 165 struct sk_buff *skb) 166 { 167 struct lowpan_peer *peer; 168 struct in6_addr *nexthop; 169 struct rt6_info *rt = (struct rt6_info *)skb_dst(skb); 170 int count = atomic_read(&dev->peer_count); 171 172 BT_DBG("peers %d addr %pI6c rt %p", count, daddr, rt); 173 174 /* If we have multiple 6lowpan peers, then check where we should 175 * send the packet. If only one peer exists, then we can send the 176 * packet right away. 177 */ 178 if (count == 1) { 179 rcu_read_lock(); 180 peer = list_first_or_null_rcu(&dev->peers, struct lowpan_peer, 181 list); 182 rcu_read_unlock(); 183 return peer; 184 } 185 186 if (!rt) { 187 nexthop = &lowpan_cb(skb)->gw; 188 189 if (ipv6_addr_any(nexthop)) 190 return NULL; 191 } else { 192 nexthop = rt6_nexthop(rt, daddr); 193 194 /* We need to remember the address because it is needed 195 * by bt_xmit() when sending the packet. In bt_xmit(), the 196 * destination routing info is not set. 197 */ 198 memcpy(&lowpan_cb(skb)->gw, nexthop, sizeof(struct in6_addr)); 199 } 200 201 BT_DBG("gw %pI6c", nexthop); 202 203 rcu_read_lock(); 204 205 list_for_each_entry_rcu(peer, &dev->peers, list) { 206 BT_DBG("dst addr %pMR dst type %d ip %pI6c", 207 &peer->chan->dst, peer->chan->dst_type, 208 &peer->peer_addr); 209 210 if (!ipv6_addr_cmp(&peer->peer_addr, nexthop)) { 211 rcu_read_unlock(); 212 return peer; 213 } 214 } 215 216 rcu_read_unlock(); 217 218 return NULL; 219 } 220 221 static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn) 222 { 223 struct lowpan_dev *entry; 224 struct lowpan_peer *peer = NULL; 225 226 rcu_read_lock(); 227 228 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 229 peer = __peer_lookup_conn(entry, conn); 230 if (peer) 231 break; 232 } 233 234 rcu_read_unlock(); 235 236 return peer; 237 } 238 239 static struct lowpan_dev *lookup_dev(struct l2cap_conn *conn) 240 { 241 struct lowpan_dev *entry; 242 struct lowpan_dev *dev = NULL; 243 244 rcu_read_lock(); 245 246 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 247 if (conn->hcon->hdev == entry->hdev) { 248 dev = entry; 249 break; 250 } 251 } 252 253 rcu_read_unlock(); 254 255 return dev; 256 } 257 258 static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev) 259 { 260 struct sk_buff *skb_cp; 261 262 skb_cp = skb_copy(skb, GFP_ATOMIC); 263 if (!skb_cp) 264 return NET_RX_DROP; 265 266 return netif_rx_ni(skb_cp); 267 } 268 269 static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev, 270 struct l2cap_chan *chan) 271 { 272 const u8 *saddr, *daddr; 273 struct lowpan_dev *dev; 274 struct lowpan_peer *peer; 275 276 dev = lowpan_dev(netdev); 277 278 rcu_read_lock(); 279 peer = __peer_lookup_chan(dev, chan); 280 rcu_read_unlock(); 281 if (!peer) 282 return -EINVAL; 283 284 saddr = peer->eui64_addr; 285 daddr = dev->netdev->dev_addr; 286 287 return lowpan_header_decompress(skb, netdev, daddr, saddr); 288 } 289 290 static int recv_pkt(struct sk_buff *skb, struct net_device *dev, 291 struct l2cap_chan *chan) 292 { 293 struct sk_buff *local_skb; 294 int ret; 295 296 if (!netif_running(dev)) 297 goto drop; 298 299 if (dev->type != ARPHRD_6LOWPAN || !skb->len) 300 goto drop; 301 302 skb_reset_network_header(skb); 303 304 skb = skb_share_check(skb, GFP_ATOMIC); 305 if (!skb) 306 goto drop; 307 308 /* check that it's our buffer */ 309 if (lowpan_is_ipv6(*skb_network_header(skb))) { 310 /* Copy the packet so that the IPv6 header is 311 * properly aligned. 312 */ 313 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1, 314 skb_tailroom(skb), GFP_ATOMIC); 315 if (!local_skb) 316 goto drop; 317 318 local_skb->protocol = htons(ETH_P_IPV6); 319 local_skb->pkt_type = PACKET_HOST; 320 321 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr)); 322 323 if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) { 324 kfree_skb(local_skb); 325 goto drop; 326 } 327 328 dev->stats.rx_bytes += skb->len; 329 dev->stats.rx_packets++; 330 331 consume_skb(local_skb); 332 consume_skb(skb); 333 } else if (lowpan_is_iphc(*skb_network_header(skb))) { 334 local_skb = skb_clone(skb, GFP_ATOMIC); 335 if (!local_skb) 336 goto drop; 337 338 ret = iphc_decompress(local_skb, dev, chan); 339 if (ret < 0) { 340 kfree_skb(local_skb); 341 goto drop; 342 } 343 344 local_skb->protocol = htons(ETH_P_IPV6); 345 local_skb->pkt_type = PACKET_HOST; 346 local_skb->dev = dev; 347 348 if (give_skb_to_upper(local_skb, dev) 349 != NET_RX_SUCCESS) { 350 kfree_skb(local_skb); 351 goto drop; 352 } 353 354 dev->stats.rx_bytes += skb->len; 355 dev->stats.rx_packets++; 356 357 consume_skb(local_skb); 358 consume_skb(skb); 359 } else { 360 goto drop; 361 } 362 363 return NET_RX_SUCCESS; 364 365 drop: 366 dev->stats.rx_dropped++; 367 return NET_RX_DROP; 368 } 369 370 /* Packet from BT LE device */ 371 static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) 372 { 373 struct lowpan_dev *dev; 374 struct lowpan_peer *peer; 375 int err; 376 377 peer = lookup_peer(chan->conn); 378 if (!peer) 379 return -ENOENT; 380 381 dev = lookup_dev(chan->conn); 382 if (!dev || !dev->netdev) 383 return -ENOENT; 384 385 err = recv_pkt(skb, dev->netdev, chan); 386 if (err) { 387 BT_DBG("recv pkt %d", err); 388 err = -EAGAIN; 389 } 390 391 return err; 392 } 393 394 static u8 get_addr_type_from_eui64(u8 byte) 395 { 396 /* Is universal(0) or local(1) bit */ 397 return ((byte & 0x02) ? BDADDR_LE_RANDOM : BDADDR_LE_PUBLIC); 398 } 399 400 static void copy_to_bdaddr(struct in6_addr *ip6_daddr, bdaddr_t *addr) 401 { 402 u8 *eui64 = ip6_daddr->s6_addr + 8; 403 404 addr->b[0] = eui64[7]; 405 addr->b[1] = eui64[6]; 406 addr->b[2] = eui64[5]; 407 addr->b[3] = eui64[2]; 408 addr->b[4] = eui64[1]; 409 addr->b[5] = eui64[0]; 410 } 411 412 static void convert_dest_bdaddr(struct in6_addr *ip6_daddr, 413 bdaddr_t *addr, u8 *addr_type) 414 { 415 copy_to_bdaddr(ip6_daddr, addr); 416 417 /* We need to toggle the U/L bit that we got from IPv6 address 418 * so that we get the proper address and type of the BD address. 419 */ 420 addr->b[5] ^= 0x02; 421 422 *addr_type = get_addr_type_from_eui64(addr->b[5]); 423 } 424 425 static int setup_header(struct sk_buff *skb, struct net_device *netdev, 426 bdaddr_t *peer_addr, u8 *peer_addr_type) 427 { 428 struct in6_addr ipv6_daddr; 429 struct lowpan_dev *dev; 430 struct lowpan_peer *peer; 431 bdaddr_t addr, *any = BDADDR_ANY; 432 u8 *daddr = any->b; 433 int err, status = 0; 434 435 dev = lowpan_dev(netdev); 436 437 memcpy(&ipv6_daddr, &lowpan_cb(skb)->addr, sizeof(ipv6_daddr)); 438 439 if (ipv6_addr_is_multicast(&ipv6_daddr)) { 440 lowpan_cb(skb)->chan = NULL; 441 } else { 442 u8 addr_type; 443 444 /* Get destination BT device from skb. 445 * If there is no such peer then discard the packet. 446 */ 447 convert_dest_bdaddr(&ipv6_daddr, &addr, &addr_type); 448 449 BT_DBG("dest addr %pMR type %d IP %pI6c", &addr, 450 addr_type, &ipv6_daddr); 451 452 peer = peer_lookup_ba(dev, &addr, addr_type); 453 if (!peer) { 454 /* The packet might be sent to 6lowpan interface 455 * because of routing (either via default route 456 * or user set route) so get peer according to 457 * the destination address. 458 */ 459 peer = peer_lookup_dst(dev, &ipv6_daddr, skb); 460 if (!peer) { 461 BT_DBG("no such peer %pMR found", &addr); 462 return -ENOENT; 463 } 464 } 465 466 daddr = peer->eui64_addr; 467 *peer_addr = addr; 468 *peer_addr_type = addr_type; 469 lowpan_cb(skb)->chan = peer->chan; 470 471 status = 1; 472 } 473 474 lowpan_header_compress(skb, netdev, daddr, dev->netdev->dev_addr); 475 476 err = dev_hard_header(skb, netdev, ETH_P_IPV6, NULL, NULL, 0); 477 if (err < 0) 478 return err; 479 480 return status; 481 } 482 483 static int header_create(struct sk_buff *skb, struct net_device *netdev, 484 unsigned short type, const void *_daddr, 485 const void *_saddr, unsigned int len) 486 { 487 struct ipv6hdr *hdr; 488 489 if (type != ETH_P_IPV6) 490 return -EINVAL; 491 492 hdr = ipv6_hdr(skb); 493 494 memcpy(&lowpan_cb(skb)->addr, &hdr->daddr, sizeof(struct in6_addr)); 495 496 return 0; 497 } 498 499 /* Packet to BT LE device */ 500 static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb, 501 struct net_device *netdev) 502 { 503 struct msghdr msg; 504 struct kvec iv; 505 int err; 506 507 /* Remember the skb so that we can send EAGAIN to the caller if 508 * we run out of credits. 509 */ 510 chan->data = skb; 511 512 iv.iov_base = skb->data; 513 iv.iov_len = skb->len; 514 515 memset(&msg, 0, sizeof(msg)); 516 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, &iv, 1, skb->len); 517 518 err = l2cap_chan_send(chan, &msg, skb->len); 519 if (err > 0) { 520 netdev->stats.tx_bytes += err; 521 netdev->stats.tx_packets++; 522 return 0; 523 } 524 525 if (!err) 526 err = lowpan_cb(skb)->status; 527 528 if (err < 0) { 529 if (err == -EAGAIN) 530 netdev->stats.tx_dropped++; 531 else 532 netdev->stats.tx_errors++; 533 } 534 535 return err; 536 } 537 538 static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev) 539 { 540 struct sk_buff *local_skb; 541 struct lowpan_dev *entry; 542 int err = 0; 543 544 rcu_read_lock(); 545 546 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 547 struct lowpan_peer *pentry; 548 struct lowpan_dev *dev; 549 550 if (entry->netdev != netdev) 551 continue; 552 553 dev = lowpan_dev(entry->netdev); 554 555 list_for_each_entry_rcu(pentry, &dev->peers, list) { 556 int ret; 557 558 local_skb = skb_clone(skb, GFP_ATOMIC); 559 560 BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p", 561 netdev->name, 562 &pentry->chan->dst, pentry->chan->dst_type, 563 &pentry->peer_addr, pentry->chan); 564 ret = send_pkt(pentry->chan, local_skb, netdev); 565 if (ret < 0) 566 err = ret; 567 568 kfree_skb(local_skb); 569 } 570 } 571 572 rcu_read_unlock(); 573 574 return err; 575 } 576 577 static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev) 578 { 579 int err = 0; 580 bdaddr_t addr; 581 u8 addr_type; 582 583 /* We must take a copy of the skb before we modify/replace the ipv6 584 * header as the header could be used elsewhere 585 */ 586 skb = skb_unshare(skb, GFP_ATOMIC); 587 if (!skb) 588 return NET_XMIT_DROP; 589 590 /* Return values from setup_header() 591 * <0 - error, packet is dropped 592 * 0 - this is a multicast packet 593 * 1 - this is unicast packet 594 */ 595 err = setup_header(skb, netdev, &addr, &addr_type); 596 if (err < 0) { 597 kfree_skb(skb); 598 return NET_XMIT_DROP; 599 } 600 601 if (err) { 602 if (lowpan_cb(skb)->chan) { 603 BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p", 604 netdev->name, &addr, addr_type, 605 &lowpan_cb(skb)->addr, lowpan_cb(skb)->chan); 606 err = send_pkt(lowpan_cb(skb)->chan, skb, netdev); 607 } else { 608 err = -ENOENT; 609 } 610 } else { 611 /* We need to send the packet to every device behind this 612 * interface. 613 */ 614 err = send_mcast_pkt(skb, netdev); 615 } 616 617 dev_kfree_skb(skb); 618 619 if (err) 620 BT_DBG("ERROR: xmit failed (%d)", err); 621 622 return err < 0 ? NET_XMIT_DROP : err; 623 } 624 625 static struct lock_class_key bt_tx_busylock; 626 static struct lock_class_key bt_netdev_xmit_lock_key; 627 628 static void bt_set_lockdep_class_one(struct net_device *dev, 629 struct netdev_queue *txq, 630 void *_unused) 631 { 632 lockdep_set_class(&txq->_xmit_lock, &bt_netdev_xmit_lock_key); 633 } 634 635 static int bt_dev_init(struct net_device *dev) 636 { 637 netdev_for_each_tx_queue(dev, bt_set_lockdep_class_one, NULL); 638 dev->qdisc_tx_busylock = &bt_tx_busylock; 639 640 return 0; 641 } 642 643 static const struct net_device_ops netdev_ops = { 644 .ndo_init = bt_dev_init, 645 .ndo_start_xmit = bt_xmit, 646 }; 647 648 static struct header_ops header_ops = { 649 .create = header_create, 650 }; 651 652 static void netdev_setup(struct net_device *dev) 653 { 654 dev->hard_header_len = 0; 655 dev->needed_tailroom = 0; 656 dev->flags = IFF_RUNNING | IFF_POINTOPOINT | 657 IFF_MULTICAST; 658 dev->watchdog_timeo = 0; 659 660 dev->netdev_ops = &netdev_ops; 661 dev->header_ops = &header_ops; 662 dev->destructor = free_netdev; 663 } 664 665 static struct device_type bt_type = { 666 .name = "bluetooth", 667 }; 668 669 static void set_addr(u8 *eui, u8 *addr, u8 addr_type) 670 { 671 /* addr is the BT address in little-endian format */ 672 eui[0] = addr[5]; 673 eui[1] = addr[4]; 674 eui[2] = addr[3]; 675 eui[3] = 0xFF; 676 eui[4] = 0xFE; 677 eui[5] = addr[2]; 678 eui[6] = addr[1]; 679 eui[7] = addr[0]; 680 681 /* Universal/local bit set, BT 6lowpan draft ch. 3.2.1 */ 682 if (addr_type == BDADDR_LE_PUBLIC) 683 eui[0] &= ~0x02; 684 else 685 eui[0] |= 0x02; 686 687 BT_DBG("type %d addr %*phC", addr_type, 8, eui); 688 } 689 690 static void set_dev_addr(struct net_device *netdev, bdaddr_t *addr, 691 u8 addr_type) 692 { 693 netdev->addr_assign_type = NET_ADDR_PERM; 694 set_addr(netdev->dev_addr, addr->b, addr_type); 695 } 696 697 static void ifup(struct net_device *netdev) 698 { 699 int err; 700 701 rtnl_lock(); 702 err = dev_open(netdev); 703 if (err < 0) 704 BT_INFO("iface %s cannot be opened (%d)", netdev->name, err); 705 rtnl_unlock(); 706 } 707 708 static void ifdown(struct net_device *netdev) 709 { 710 int err; 711 712 rtnl_lock(); 713 err = dev_close(netdev); 714 if (err < 0) 715 BT_INFO("iface %s cannot be closed (%d)", netdev->name, err); 716 rtnl_unlock(); 717 } 718 719 static void do_notify_peers(struct work_struct *work) 720 { 721 struct lowpan_dev *dev = container_of(work, struct lowpan_dev, 722 notify_peers.work); 723 724 netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */ 725 } 726 727 static bool is_bt_6lowpan(struct hci_conn *hcon) 728 { 729 if (hcon->type != LE_LINK) 730 return false; 731 732 if (!enable_6lowpan) 733 return false; 734 735 return true; 736 } 737 738 static struct l2cap_chan *chan_create(void) 739 { 740 struct l2cap_chan *chan; 741 742 chan = l2cap_chan_create(); 743 if (!chan) 744 return NULL; 745 746 l2cap_chan_set_defaults(chan); 747 748 chan->chan_type = L2CAP_CHAN_CONN_ORIENTED; 749 chan->mode = L2CAP_MODE_LE_FLOWCTL; 750 chan->imtu = 1280; 751 752 return chan; 753 } 754 755 static void set_ip_addr_bits(u8 addr_type, u8 *addr) 756 { 757 if (addr_type == BDADDR_LE_PUBLIC) 758 *addr |= 0x02; 759 else 760 *addr &= ~0x02; 761 } 762 763 static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan, 764 struct lowpan_dev *dev) 765 { 766 struct lowpan_peer *peer; 767 768 peer = kzalloc(sizeof(*peer), GFP_ATOMIC); 769 if (!peer) 770 return NULL; 771 772 peer->chan = chan; 773 memset(&peer->peer_addr, 0, sizeof(struct in6_addr)); 774 775 /* RFC 2464 ch. 5 */ 776 peer->peer_addr.s6_addr[0] = 0xFE; 777 peer->peer_addr.s6_addr[1] = 0x80; 778 set_addr((u8 *)&peer->peer_addr.s6_addr + 8, chan->dst.b, 779 chan->dst_type); 780 781 memcpy(&peer->eui64_addr, (u8 *)&peer->peer_addr.s6_addr + 8, 782 EUI64_ADDR_LEN); 783 784 /* IPv6 address needs to have the U/L bit set properly so toggle 785 * it back here. 786 */ 787 set_ip_addr_bits(chan->dst_type, (u8 *)&peer->peer_addr.s6_addr + 8); 788 789 spin_lock(&devices_lock); 790 INIT_LIST_HEAD(&peer->list); 791 peer_add(dev, peer); 792 spin_unlock(&devices_lock); 793 794 /* Notifying peers about us needs to be done without locks held */ 795 INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers); 796 schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100)); 797 798 return peer->chan; 799 } 800 801 static int setup_netdev(struct l2cap_chan *chan, struct lowpan_dev **dev) 802 { 803 struct net_device *netdev; 804 int err = 0; 805 806 netdev = alloc_netdev(LOWPAN_PRIV_SIZE(sizeof(struct lowpan_dev)), 807 IFACE_NAME_TEMPLATE, NET_NAME_UNKNOWN, 808 netdev_setup); 809 if (!netdev) 810 return -ENOMEM; 811 812 set_dev_addr(netdev, &chan->src, chan->src_type); 813 814 netdev->netdev_ops = &netdev_ops; 815 SET_NETDEV_DEV(netdev, &chan->conn->hcon->hdev->dev); 816 SET_NETDEV_DEVTYPE(netdev, &bt_type); 817 818 *dev = lowpan_dev(netdev); 819 (*dev)->netdev = netdev; 820 (*dev)->hdev = chan->conn->hcon->hdev; 821 INIT_LIST_HEAD(&(*dev)->peers); 822 823 spin_lock(&devices_lock); 824 INIT_LIST_HEAD(&(*dev)->list); 825 list_add_rcu(&(*dev)->list, &bt_6lowpan_devices); 826 spin_unlock(&devices_lock); 827 828 lowpan_netdev_setup(netdev, LOWPAN_LLTYPE_BTLE); 829 830 err = register_netdev(netdev); 831 if (err < 0) { 832 BT_INFO("register_netdev failed %d", err); 833 spin_lock(&devices_lock); 834 list_del_rcu(&(*dev)->list); 835 spin_unlock(&devices_lock); 836 free_netdev(netdev); 837 goto out; 838 } 839 840 BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d", 841 netdev->ifindex, &chan->dst, chan->dst_type, 842 &chan->src, chan->src_type); 843 set_bit(__LINK_STATE_PRESENT, &netdev->state); 844 845 return 0; 846 847 out: 848 return err; 849 } 850 851 static inline void chan_ready_cb(struct l2cap_chan *chan) 852 { 853 struct lowpan_dev *dev; 854 855 dev = lookup_dev(chan->conn); 856 857 BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev); 858 859 if (!dev) { 860 if (setup_netdev(chan, &dev) < 0) { 861 l2cap_chan_del(chan, -ENOENT); 862 return; 863 } 864 } 865 866 if (!try_module_get(THIS_MODULE)) 867 return; 868 869 add_peer_chan(chan, dev); 870 ifup(dev->netdev); 871 } 872 873 static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan) 874 { 875 struct l2cap_chan *chan; 876 877 chan = chan_create(); 878 if (!chan) 879 return NULL; 880 881 chan->ops = pchan->ops; 882 883 BT_DBG("chan %p pchan %p", chan, pchan); 884 885 return chan; 886 } 887 888 static void delete_netdev(struct work_struct *work) 889 { 890 struct lowpan_dev *entry = container_of(work, struct lowpan_dev, 891 delete_netdev); 892 893 unregister_netdev(entry->netdev); 894 895 /* The entry pointer is deleted by the netdev destructor. */ 896 } 897 898 static void chan_close_cb(struct l2cap_chan *chan) 899 { 900 struct lowpan_dev *entry; 901 struct lowpan_dev *dev = NULL; 902 struct lowpan_peer *peer; 903 int err = -ENOENT; 904 bool last = false, remove = true; 905 906 BT_DBG("chan %p conn %p", chan, chan->conn); 907 908 if (chan->conn && chan->conn->hcon) { 909 if (!is_bt_6lowpan(chan->conn->hcon)) 910 return; 911 912 /* If conn is set, then the netdev is also there and we should 913 * not remove it. 914 */ 915 remove = false; 916 } 917 918 spin_lock(&devices_lock); 919 920 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 921 dev = lowpan_dev(entry->netdev); 922 peer = __peer_lookup_chan(dev, chan); 923 if (peer) { 924 last = peer_del(dev, peer); 925 err = 0; 926 927 BT_DBG("dev %p removing %speer %p", dev, 928 last ? "last " : "1 ", peer); 929 BT_DBG("chan %p orig refcnt %d", chan, 930 atomic_read(&chan->kref.refcount)); 931 932 l2cap_chan_put(chan); 933 break; 934 } 935 } 936 937 if (!err && last && dev && !atomic_read(&dev->peer_count)) { 938 spin_unlock(&devices_lock); 939 940 cancel_delayed_work_sync(&dev->notify_peers); 941 942 ifdown(dev->netdev); 943 944 if (remove) { 945 INIT_WORK(&entry->delete_netdev, delete_netdev); 946 schedule_work(&entry->delete_netdev); 947 } 948 } else { 949 spin_unlock(&devices_lock); 950 } 951 952 return; 953 } 954 955 static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err) 956 { 957 BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn, 958 state_to_string(state), err); 959 } 960 961 static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan, 962 unsigned long hdr_len, 963 unsigned long len, int nb) 964 { 965 /* Note that we must allocate using GFP_ATOMIC here as 966 * this function is called originally from netdev hard xmit 967 * function in atomic context. 968 */ 969 return bt_skb_alloc(hdr_len + len, GFP_ATOMIC); 970 } 971 972 static void chan_suspend_cb(struct l2cap_chan *chan) 973 { 974 struct sk_buff *skb = chan->data; 975 976 BT_DBG("chan %p conn %p skb %p", chan, chan->conn, skb); 977 978 if (!skb) 979 return; 980 981 lowpan_cb(skb)->status = -EAGAIN; 982 } 983 984 static void chan_resume_cb(struct l2cap_chan *chan) 985 { 986 struct sk_buff *skb = chan->data; 987 988 BT_DBG("chan %p conn %p skb %p", chan, chan->conn, skb); 989 990 if (!skb) 991 return; 992 993 lowpan_cb(skb)->status = 0; 994 } 995 996 static long chan_get_sndtimeo_cb(struct l2cap_chan *chan) 997 { 998 return L2CAP_CONN_TIMEOUT; 999 } 1000 1001 static const struct l2cap_ops bt_6lowpan_chan_ops = { 1002 .name = "L2CAP 6LoWPAN channel", 1003 .new_connection = chan_new_conn_cb, 1004 .recv = chan_recv_cb, 1005 .close = chan_close_cb, 1006 .state_change = chan_state_change_cb, 1007 .ready = chan_ready_cb, 1008 .resume = chan_resume_cb, 1009 .suspend = chan_suspend_cb, 1010 .get_sndtimeo = chan_get_sndtimeo_cb, 1011 .alloc_skb = chan_alloc_skb_cb, 1012 1013 .teardown = l2cap_chan_no_teardown, 1014 .defer = l2cap_chan_no_defer, 1015 .set_shutdown = l2cap_chan_no_set_shutdown, 1016 }; 1017 1018 static inline __u8 bdaddr_type(__u8 type) 1019 { 1020 if (type == ADDR_LE_DEV_PUBLIC) 1021 return BDADDR_LE_PUBLIC; 1022 else 1023 return BDADDR_LE_RANDOM; 1024 } 1025 1026 static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type) 1027 { 1028 struct l2cap_chan *chan; 1029 int err; 1030 1031 chan = chan_create(); 1032 if (!chan) 1033 return -EINVAL; 1034 1035 chan->ops = &bt_6lowpan_chan_ops; 1036 1037 err = l2cap_chan_connect(chan, cpu_to_le16(L2CAP_PSM_IPSP), 0, 1038 addr, dst_type); 1039 1040 BT_DBG("chan %p err %d", chan, err); 1041 if (err < 0) 1042 l2cap_chan_put(chan); 1043 1044 return err; 1045 } 1046 1047 static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type) 1048 { 1049 struct lowpan_peer *peer; 1050 1051 BT_DBG("conn %p dst type %d", conn, dst_type); 1052 1053 peer = lookup_peer(conn); 1054 if (!peer) 1055 return -ENOENT; 1056 1057 BT_DBG("peer %p chan %p", peer, peer->chan); 1058 1059 l2cap_chan_close(peer->chan, ENOENT); 1060 1061 return 0; 1062 } 1063 1064 static struct l2cap_chan *bt_6lowpan_listen(void) 1065 { 1066 bdaddr_t *addr = BDADDR_ANY; 1067 struct l2cap_chan *chan; 1068 int err; 1069 1070 if (!enable_6lowpan) 1071 return NULL; 1072 1073 chan = chan_create(); 1074 if (!chan) 1075 return NULL; 1076 1077 chan->ops = &bt_6lowpan_chan_ops; 1078 chan->state = BT_LISTEN; 1079 chan->src_type = BDADDR_LE_PUBLIC; 1080 1081 atomic_set(&chan->nesting, L2CAP_NESTING_PARENT); 1082 1083 BT_DBG("chan %p src type %d", chan, chan->src_type); 1084 1085 err = l2cap_add_psm(chan, addr, cpu_to_le16(L2CAP_PSM_IPSP)); 1086 if (err) { 1087 l2cap_chan_put(chan); 1088 BT_ERR("psm cannot be added err %d", err); 1089 return NULL; 1090 } 1091 1092 return chan; 1093 } 1094 1095 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type, 1096 struct l2cap_conn **conn) 1097 { 1098 struct hci_conn *hcon; 1099 struct hci_dev *hdev; 1100 bdaddr_t *src = BDADDR_ANY; 1101 int n; 1102 1103 n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu", 1104 &addr->b[5], &addr->b[4], &addr->b[3], 1105 &addr->b[2], &addr->b[1], &addr->b[0], 1106 addr_type); 1107 1108 if (n < 7) 1109 return -EINVAL; 1110 1111 hdev = hci_get_route(addr, src); 1112 if (!hdev) 1113 return -ENOENT; 1114 1115 hci_dev_lock(hdev); 1116 hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type); 1117 hci_dev_unlock(hdev); 1118 1119 if (!hcon) 1120 return -ENOENT; 1121 1122 *conn = (struct l2cap_conn *)hcon->l2cap_data; 1123 1124 BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type); 1125 1126 return 0; 1127 } 1128 1129 static void disconnect_all_peers(void) 1130 { 1131 struct lowpan_dev *entry; 1132 struct lowpan_peer *peer, *tmp_peer, *new_peer; 1133 struct list_head peers; 1134 1135 INIT_LIST_HEAD(&peers); 1136 1137 /* We make a separate list of peers as the close_cb() will 1138 * modify the device peers list so it is better not to mess 1139 * with the same list at the same time. 1140 */ 1141 1142 rcu_read_lock(); 1143 1144 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 1145 list_for_each_entry_rcu(peer, &entry->peers, list) { 1146 new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC); 1147 if (!new_peer) 1148 break; 1149 1150 new_peer->chan = peer->chan; 1151 INIT_LIST_HEAD(&new_peer->list); 1152 1153 list_add(&new_peer->list, &peers); 1154 } 1155 } 1156 1157 rcu_read_unlock(); 1158 1159 spin_lock(&devices_lock); 1160 list_for_each_entry_safe(peer, tmp_peer, &peers, list) { 1161 l2cap_chan_close(peer->chan, ENOENT); 1162 1163 list_del_rcu(&peer->list); 1164 kfree_rcu(peer, rcu); 1165 } 1166 spin_unlock(&devices_lock); 1167 } 1168 1169 struct set_enable { 1170 struct work_struct work; 1171 bool flag; 1172 }; 1173 1174 static void do_enable_set(struct work_struct *work) 1175 { 1176 struct set_enable *set_enable = container_of(work, 1177 struct set_enable, work); 1178 1179 if (!set_enable->flag || enable_6lowpan != set_enable->flag) 1180 /* Disconnect existing connections if 6lowpan is 1181 * disabled 1182 */ 1183 disconnect_all_peers(); 1184 1185 enable_6lowpan = set_enable->flag; 1186 1187 if (listen_chan) { 1188 l2cap_chan_close(listen_chan, 0); 1189 l2cap_chan_put(listen_chan); 1190 } 1191 1192 listen_chan = bt_6lowpan_listen(); 1193 1194 kfree(set_enable); 1195 } 1196 1197 static int lowpan_enable_set(void *data, u64 val) 1198 { 1199 struct set_enable *set_enable; 1200 1201 set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL); 1202 if (!set_enable) 1203 return -ENOMEM; 1204 1205 set_enable->flag = !!val; 1206 INIT_WORK(&set_enable->work, do_enable_set); 1207 1208 schedule_work(&set_enable->work); 1209 1210 return 0; 1211 } 1212 1213 static int lowpan_enable_get(void *data, u64 *val) 1214 { 1215 *val = enable_6lowpan; 1216 return 0; 1217 } 1218 1219 DEFINE_SIMPLE_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get, 1220 lowpan_enable_set, "%llu\n"); 1221 1222 static ssize_t lowpan_control_write(struct file *fp, 1223 const char __user *user_buffer, 1224 size_t count, 1225 loff_t *position) 1226 { 1227 char buf[32]; 1228 size_t buf_size = min(count, sizeof(buf) - 1); 1229 int ret; 1230 bdaddr_t addr; 1231 u8 addr_type; 1232 struct l2cap_conn *conn = NULL; 1233 1234 if (copy_from_user(buf, user_buffer, buf_size)) 1235 return -EFAULT; 1236 1237 buf[buf_size] = '\0'; 1238 1239 if (memcmp(buf, "connect ", 8) == 0) { 1240 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn); 1241 if (ret == -EINVAL) 1242 return ret; 1243 1244 if (listen_chan) { 1245 l2cap_chan_close(listen_chan, 0); 1246 l2cap_chan_put(listen_chan); 1247 listen_chan = NULL; 1248 } 1249 1250 if (conn) { 1251 struct lowpan_peer *peer; 1252 1253 if (!is_bt_6lowpan(conn->hcon)) 1254 return -EINVAL; 1255 1256 peer = lookup_peer(conn); 1257 if (peer) { 1258 BT_DBG("6LoWPAN connection already exists"); 1259 return -EALREADY; 1260 } 1261 1262 BT_DBG("conn %p dst %pMR type %d user %d", conn, 1263 &conn->hcon->dst, conn->hcon->dst_type, 1264 addr_type); 1265 } 1266 1267 ret = bt_6lowpan_connect(&addr, addr_type); 1268 if (ret < 0) 1269 return ret; 1270 1271 return count; 1272 } 1273 1274 if (memcmp(buf, "disconnect ", 11) == 0) { 1275 ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn); 1276 if (ret < 0) 1277 return ret; 1278 1279 ret = bt_6lowpan_disconnect(conn, addr_type); 1280 if (ret < 0) 1281 return ret; 1282 1283 return count; 1284 } 1285 1286 return count; 1287 } 1288 1289 static int lowpan_control_show(struct seq_file *f, void *ptr) 1290 { 1291 struct lowpan_dev *entry; 1292 struct lowpan_peer *peer; 1293 1294 spin_lock(&devices_lock); 1295 1296 list_for_each_entry(entry, &bt_6lowpan_devices, list) { 1297 list_for_each_entry(peer, &entry->peers, list) 1298 seq_printf(f, "%pMR (type %u)\n", 1299 &peer->chan->dst, peer->chan->dst_type); 1300 } 1301 1302 spin_unlock(&devices_lock); 1303 1304 return 0; 1305 } 1306 1307 static int lowpan_control_open(struct inode *inode, struct file *file) 1308 { 1309 return single_open(file, lowpan_control_show, inode->i_private); 1310 } 1311 1312 static const struct file_operations lowpan_control_fops = { 1313 .open = lowpan_control_open, 1314 .read = seq_read, 1315 .write = lowpan_control_write, 1316 .llseek = seq_lseek, 1317 .release = single_release, 1318 }; 1319 1320 static void disconnect_devices(void) 1321 { 1322 struct lowpan_dev *entry, *tmp, *new_dev; 1323 struct list_head devices; 1324 1325 INIT_LIST_HEAD(&devices); 1326 1327 /* We make a separate list of devices because the unregister_netdev() 1328 * will call device_event() which will also want to modify the same 1329 * devices list. 1330 */ 1331 1332 rcu_read_lock(); 1333 1334 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 1335 new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC); 1336 if (!new_dev) 1337 break; 1338 1339 new_dev->netdev = entry->netdev; 1340 INIT_LIST_HEAD(&new_dev->list); 1341 1342 list_add_rcu(&new_dev->list, &devices); 1343 } 1344 1345 rcu_read_unlock(); 1346 1347 list_for_each_entry_safe(entry, tmp, &devices, list) { 1348 ifdown(entry->netdev); 1349 BT_DBG("Unregistering netdev %s %p", 1350 entry->netdev->name, entry->netdev); 1351 unregister_netdev(entry->netdev); 1352 kfree(entry); 1353 } 1354 } 1355 1356 static int device_event(struct notifier_block *unused, 1357 unsigned long event, void *ptr) 1358 { 1359 struct net_device *netdev = netdev_notifier_info_to_dev(ptr); 1360 struct lowpan_dev *entry; 1361 1362 if (netdev->type != ARPHRD_6LOWPAN) 1363 return NOTIFY_DONE; 1364 1365 switch (event) { 1366 case NETDEV_UNREGISTER: 1367 spin_lock(&devices_lock); 1368 list_for_each_entry(entry, &bt_6lowpan_devices, list) { 1369 if (entry->netdev == netdev) { 1370 BT_DBG("Unregistered netdev %s %p", 1371 netdev->name, netdev); 1372 list_del(&entry->list); 1373 break; 1374 } 1375 } 1376 spin_unlock(&devices_lock); 1377 break; 1378 } 1379 1380 return NOTIFY_DONE; 1381 } 1382 1383 static struct notifier_block bt_6lowpan_dev_notifier = { 1384 .notifier_call = device_event, 1385 }; 1386 1387 static int __init bt_6lowpan_init(void) 1388 { 1389 lowpan_enable_debugfs = debugfs_create_file("6lowpan_enable", 0644, 1390 bt_debugfs, NULL, 1391 &lowpan_enable_fops); 1392 lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644, 1393 bt_debugfs, NULL, 1394 &lowpan_control_fops); 1395 1396 return register_netdevice_notifier(&bt_6lowpan_dev_notifier); 1397 } 1398 1399 static void __exit bt_6lowpan_exit(void) 1400 { 1401 debugfs_remove(lowpan_enable_debugfs); 1402 debugfs_remove(lowpan_control_debugfs); 1403 1404 if (listen_chan) { 1405 l2cap_chan_close(listen_chan, 0); 1406 l2cap_chan_put(listen_chan); 1407 } 1408 1409 disconnect_devices(); 1410 1411 unregister_netdevice_notifier(&bt_6lowpan_dev_notifier); 1412 } 1413 1414 module_init(bt_6lowpan_init); 1415 module_exit(bt_6lowpan_exit); 1416 1417 MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>"); 1418 MODULE_DESCRIPTION("Bluetooth 6LoWPAN"); 1419 MODULE_VERSION(VERSION); 1420 MODULE_LICENSE("GPL"); 1421