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/af_ieee802154.h> /* to get the address type */ 25 26 #include <net/bluetooth/bluetooth.h> 27 #include <net/bluetooth/hci_core.h> 28 #include <net/bluetooth/l2cap.h> 29 30 #include <net/6lowpan.h> /* for the compression support */ 31 32 #define VERSION "0.1" 33 34 static struct dentry *lowpan_enable_debugfs; 35 static struct dentry *lowpan_control_debugfs; 36 37 #define IFACE_NAME_TEMPLATE "bt%d" 38 #define EUI64_ADDR_LEN 8 39 40 struct skb_cb { 41 struct in6_addr addr; 42 struct in6_addr gw; 43 struct l2cap_chan *chan; 44 int status; 45 }; 46 #define lowpan_cb(skb) ((struct skb_cb *)((skb)->cb)) 47 48 /* The devices list contains those devices that we are acting 49 * as a proxy. The BT 6LoWPAN device is a virtual device that 50 * connects to the Bluetooth LE device. The real connection to 51 * BT device is done via l2cap layer. There exists one 52 * virtual device / one BT 6LoWPAN network (=hciX device). 53 * The list contains struct lowpan_dev elements. 54 */ 55 static LIST_HEAD(bt_6lowpan_devices); 56 static DEFINE_SPINLOCK(devices_lock); 57 58 static bool enable_6lowpan; 59 60 /* We are listening incoming connections via this channel 61 */ 62 static struct l2cap_chan *listen_chan; 63 64 struct lowpan_peer { 65 struct list_head list; 66 struct rcu_head rcu; 67 struct l2cap_chan *chan; 68 69 /* peer addresses in various formats */ 70 unsigned char eui64_addr[EUI64_ADDR_LEN]; 71 struct in6_addr peer_addr; 72 }; 73 74 struct lowpan_dev { 75 struct list_head list; 76 77 struct hci_dev *hdev; 78 struct net_device *netdev; 79 struct list_head peers; 80 atomic_t peer_count; /* number of items in peers list */ 81 82 struct work_struct delete_netdev; 83 struct delayed_work notify_peers; 84 }; 85 86 static inline struct lowpan_dev *lowpan_dev(const struct net_device *netdev) 87 { 88 return netdev_priv(netdev); 89 } 90 91 static inline void peer_add(struct lowpan_dev *dev, struct lowpan_peer *peer) 92 { 93 list_add_rcu(&peer->list, &dev->peers); 94 atomic_inc(&dev->peer_count); 95 } 96 97 static inline bool peer_del(struct lowpan_dev *dev, 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_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 *__peer_lookup_chan(struct lowpan_dev *dev, 141 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 *__peer_lookup_conn(struct lowpan_dev *dev, 154 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_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_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_dev *lookup_dev(struct l2cap_conn *conn) 243 { 244 struct lowpan_dev *entry; 245 struct lowpan_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(skb_cp); 270 } 271 272 static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev, 273 struct l2cap_chan *chan) 274 { 275 const u8 *saddr, *daddr; 276 u8 iphc0, iphc1; 277 struct lowpan_dev *dev; 278 struct lowpan_peer *peer; 279 280 dev = lowpan_dev(netdev); 281 282 rcu_read_lock(); 283 peer = __peer_lookup_chan(dev, chan); 284 rcu_read_unlock(); 285 if (!peer) 286 return -EINVAL; 287 288 saddr = peer->eui64_addr; 289 daddr = dev->netdev->dev_addr; 290 291 /* at least two bytes will be used for the encoding */ 292 if (skb->len < 2) 293 return -EINVAL; 294 295 if (lowpan_fetch_skb_u8(skb, &iphc0)) 296 return -EINVAL; 297 298 if (lowpan_fetch_skb_u8(skb, &iphc1)) 299 return -EINVAL; 300 301 return lowpan_header_decompress(skb, netdev, 302 saddr, IEEE802154_ADDR_LONG, 303 EUI64_ADDR_LEN, daddr, 304 IEEE802154_ADDR_LONG, EUI64_ADDR_LEN, 305 iphc0, iphc1); 306 307 } 308 309 static int recv_pkt(struct sk_buff *skb, struct net_device *dev, 310 struct l2cap_chan *chan) 311 { 312 struct sk_buff *local_skb; 313 int ret; 314 315 if (!netif_running(dev)) 316 goto drop; 317 318 if (dev->type != ARPHRD_6LOWPAN) 319 goto drop; 320 321 skb = skb_share_check(skb, GFP_ATOMIC); 322 if (!skb) 323 goto drop; 324 325 /* check that it's our buffer */ 326 if (skb->data[0] == LOWPAN_DISPATCH_IPV6) { 327 /* Copy the packet so that the IPv6 header is 328 * properly aligned. 329 */ 330 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1, 331 skb_tailroom(skb), GFP_ATOMIC); 332 if (!local_skb) 333 goto drop; 334 335 local_skb->protocol = htons(ETH_P_IPV6); 336 local_skb->pkt_type = PACKET_HOST; 337 338 skb_reset_network_header(local_skb); 339 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr)); 340 341 if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) { 342 kfree_skb(local_skb); 343 goto drop; 344 } 345 346 dev->stats.rx_bytes += skb->len; 347 dev->stats.rx_packets++; 348 349 consume_skb(local_skb); 350 consume_skb(skb); 351 } else { 352 switch (skb->data[0] & 0xe0) { 353 case LOWPAN_DISPATCH_IPHC: /* ipv6 datagram */ 354 local_skb = skb_clone(skb, GFP_ATOMIC); 355 if (!local_skb) 356 goto drop; 357 358 ret = iphc_decompress(local_skb, dev, chan); 359 if (ret < 0) { 360 kfree_skb(local_skb); 361 goto drop; 362 } 363 364 local_skb->protocol = htons(ETH_P_IPV6); 365 local_skb->pkt_type = PACKET_HOST; 366 local_skb->dev = dev; 367 368 if (give_skb_to_upper(local_skb, dev) 369 != NET_RX_SUCCESS) { 370 kfree_skb(local_skb); 371 goto drop; 372 } 373 374 dev->stats.rx_bytes += skb->len; 375 dev->stats.rx_packets++; 376 377 consume_skb(local_skb); 378 consume_skb(skb); 379 break; 380 default: 381 break; 382 } 383 } 384 385 return NET_RX_SUCCESS; 386 387 drop: 388 dev->stats.rx_dropped++; 389 return NET_RX_DROP; 390 } 391 392 /* Packet from BT LE device */ 393 static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb) 394 { 395 struct lowpan_dev *dev; 396 struct lowpan_peer *peer; 397 int err; 398 399 peer = lookup_peer(chan->conn); 400 if (!peer) 401 return -ENOENT; 402 403 dev = lookup_dev(chan->conn); 404 if (!dev || !dev->netdev) 405 return -ENOENT; 406 407 err = recv_pkt(skb, dev->netdev, chan); 408 if (err) { 409 BT_DBG("recv pkt %d", err); 410 err = -EAGAIN; 411 } 412 413 return err; 414 } 415 416 static u8 get_addr_type_from_eui64(u8 byte) 417 { 418 /* Is universal(0) or local(1) bit */ 419 return ((byte & 0x02) ? BDADDR_LE_RANDOM : BDADDR_LE_PUBLIC); 420 } 421 422 static void copy_to_bdaddr(struct in6_addr *ip6_daddr, bdaddr_t *addr) 423 { 424 u8 *eui64 = ip6_daddr->s6_addr + 8; 425 426 addr->b[0] = eui64[7]; 427 addr->b[1] = eui64[6]; 428 addr->b[2] = eui64[5]; 429 addr->b[3] = eui64[2]; 430 addr->b[4] = eui64[1]; 431 addr->b[5] = eui64[0]; 432 } 433 434 static void convert_dest_bdaddr(struct in6_addr *ip6_daddr, 435 bdaddr_t *addr, u8 *addr_type) 436 { 437 copy_to_bdaddr(ip6_daddr, addr); 438 439 /* We need to toggle the U/L bit that we got from IPv6 address 440 * so that we get the proper address and type of the BD address. 441 */ 442 addr->b[5] ^= 0x02; 443 444 *addr_type = get_addr_type_from_eui64(addr->b[5]); 445 } 446 447 static int setup_header(struct sk_buff *skb, struct net_device *netdev, 448 bdaddr_t *peer_addr, u8 *peer_addr_type) 449 { 450 struct in6_addr ipv6_daddr; 451 struct lowpan_dev *dev; 452 struct lowpan_peer *peer; 453 bdaddr_t addr, *any = BDADDR_ANY; 454 u8 *daddr = any->b; 455 int err, status = 0; 456 457 dev = lowpan_dev(netdev); 458 459 memcpy(&ipv6_daddr, &lowpan_cb(skb)->addr, sizeof(ipv6_daddr)); 460 461 if (ipv6_addr_is_multicast(&ipv6_daddr)) { 462 lowpan_cb(skb)->chan = NULL; 463 } else { 464 u8 addr_type; 465 466 /* Get destination BT device from skb. 467 * If there is no such peer then discard the packet. 468 */ 469 convert_dest_bdaddr(&ipv6_daddr, &addr, &addr_type); 470 471 BT_DBG("dest addr %pMR type %d IP %pI6c", &addr, 472 addr_type, &ipv6_daddr); 473 474 peer = peer_lookup_ba(dev, &addr, addr_type); 475 if (!peer) { 476 /* The packet might be sent to 6lowpan interface 477 * because of routing (either via default route 478 * or user set route) so get peer according to 479 * the destination address. 480 */ 481 peer = peer_lookup_dst(dev, &ipv6_daddr, skb); 482 if (!peer) { 483 BT_DBG("no such peer %pMR found", &addr); 484 return -ENOENT; 485 } 486 } 487 488 daddr = peer->eui64_addr; 489 *peer_addr = addr; 490 *peer_addr_type = addr_type; 491 lowpan_cb(skb)->chan = peer->chan; 492 493 status = 1; 494 } 495 496 lowpan_header_compress(skb, netdev, ETH_P_IPV6, daddr, 497 dev->netdev->dev_addr, skb->len); 498 499 err = dev_hard_header(skb, netdev, ETH_P_IPV6, NULL, NULL, 0); 500 if (err < 0) 501 return err; 502 503 return status; 504 } 505 506 static int header_create(struct sk_buff *skb, struct net_device *netdev, 507 unsigned short type, const void *_daddr, 508 const void *_saddr, unsigned int len) 509 { 510 struct ipv6hdr *hdr; 511 512 if (type != ETH_P_IPV6) 513 return -EINVAL; 514 515 hdr = ipv6_hdr(skb); 516 517 memcpy(&lowpan_cb(skb)->addr, &hdr->daddr, sizeof(struct in6_addr)); 518 519 return 0; 520 } 521 522 /* Packet to BT LE device */ 523 static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb, 524 struct net_device *netdev) 525 { 526 struct msghdr msg; 527 struct kvec iv; 528 int err; 529 530 /* Remember the skb so that we can send EAGAIN to the caller if 531 * we run out of credits. 532 */ 533 chan->data = skb; 534 535 iv.iov_base = skb->data; 536 iv.iov_len = skb->len; 537 538 memset(&msg, 0, sizeof(msg)); 539 iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, &iv, 1, skb->len); 540 541 err = l2cap_chan_send(chan, &msg, skb->len); 542 if (err > 0) { 543 netdev->stats.tx_bytes += err; 544 netdev->stats.tx_packets++; 545 return 0; 546 } 547 548 if (!err) 549 err = lowpan_cb(skb)->status; 550 551 if (err < 0) { 552 if (err == -EAGAIN) 553 netdev->stats.tx_dropped++; 554 else 555 netdev->stats.tx_errors++; 556 } 557 558 return err; 559 } 560 561 static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev) 562 { 563 struct sk_buff *local_skb; 564 struct lowpan_dev *entry; 565 int err = 0; 566 567 rcu_read_lock(); 568 569 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 570 struct lowpan_peer *pentry; 571 struct lowpan_dev *dev; 572 573 if (entry->netdev != netdev) 574 continue; 575 576 dev = lowpan_dev(entry->netdev); 577 578 list_for_each_entry_rcu(pentry, &dev->peers, list) { 579 int ret; 580 581 local_skb = skb_clone(skb, GFP_ATOMIC); 582 583 BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p", 584 netdev->name, 585 &pentry->chan->dst, pentry->chan->dst_type, 586 &pentry->peer_addr, pentry->chan); 587 ret = send_pkt(pentry->chan, local_skb, netdev); 588 if (ret < 0) 589 err = ret; 590 591 kfree_skb(local_skb); 592 } 593 } 594 595 rcu_read_unlock(); 596 597 return err; 598 } 599 600 static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev) 601 { 602 int err = 0; 603 bdaddr_t addr; 604 u8 addr_type; 605 606 /* We must take a copy of the skb before we modify/replace the ipv6 607 * header as the header could be used elsewhere 608 */ 609 skb = skb_unshare(skb, GFP_ATOMIC); 610 if (!skb) 611 return NET_XMIT_DROP; 612 613 /* Return values from setup_header() 614 * <0 - error, packet is dropped 615 * 0 - this is a multicast packet 616 * 1 - this is unicast packet 617 */ 618 err = setup_header(skb, netdev, &addr, &addr_type); 619 if (err < 0) { 620 kfree_skb(skb); 621 return NET_XMIT_DROP; 622 } 623 624 if (err) { 625 if (lowpan_cb(skb)->chan) { 626 BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p", 627 netdev->name, &addr, addr_type, 628 &lowpan_cb(skb)->addr, lowpan_cb(skb)->chan); 629 err = send_pkt(lowpan_cb(skb)->chan, skb, netdev); 630 } else { 631 err = -ENOENT; 632 } 633 } else { 634 /* We need to send the packet to every device behind this 635 * interface. 636 */ 637 err = send_mcast_pkt(skb, netdev); 638 } 639 640 dev_kfree_skb(skb); 641 642 if (err) 643 BT_DBG("ERROR: xmit failed (%d)", err); 644 645 return err < 0 ? NET_XMIT_DROP : err; 646 } 647 648 static struct lock_class_key bt_tx_busylock; 649 static struct lock_class_key bt_netdev_xmit_lock_key; 650 651 static void bt_set_lockdep_class_one(struct net_device *dev, 652 struct netdev_queue *txq, 653 void *_unused) 654 { 655 lockdep_set_class(&txq->_xmit_lock, &bt_netdev_xmit_lock_key); 656 } 657 658 static int bt_dev_init(struct net_device *dev) 659 { 660 netdev_for_each_tx_queue(dev, bt_set_lockdep_class_one, NULL); 661 dev->qdisc_tx_busylock = &bt_tx_busylock; 662 663 return 0; 664 } 665 666 static const struct net_device_ops netdev_ops = { 667 .ndo_init = bt_dev_init, 668 .ndo_start_xmit = bt_xmit, 669 }; 670 671 static struct header_ops header_ops = { 672 .create = header_create, 673 }; 674 675 static void netdev_setup(struct net_device *dev) 676 { 677 dev->addr_len = EUI64_ADDR_LEN; 678 dev->type = ARPHRD_6LOWPAN; 679 680 dev->hard_header_len = 0; 681 dev->needed_tailroom = 0; 682 dev->mtu = IPV6_MIN_MTU; 683 dev->tx_queue_len = 0; 684 dev->flags = IFF_RUNNING | IFF_POINTOPOINT | 685 IFF_MULTICAST; 686 dev->watchdog_timeo = 0; 687 688 dev->netdev_ops = &netdev_ops; 689 dev->header_ops = &header_ops; 690 dev->destructor = free_netdev; 691 } 692 693 static struct device_type bt_type = { 694 .name = "bluetooth", 695 }; 696 697 static void set_addr(u8 *eui, u8 *addr, u8 addr_type) 698 { 699 /* addr is the BT address in little-endian format */ 700 eui[0] = addr[5]; 701 eui[1] = addr[4]; 702 eui[2] = addr[3]; 703 eui[3] = 0xFF; 704 eui[4] = 0xFE; 705 eui[5] = addr[2]; 706 eui[6] = addr[1]; 707 eui[7] = addr[0]; 708 709 /* Universal/local bit set, BT 6lowpan draft ch. 3.2.1 */ 710 if (addr_type == BDADDR_LE_PUBLIC) 711 eui[0] &= ~0x02; 712 else 713 eui[0] |= 0x02; 714 715 BT_DBG("type %d addr %*phC", addr_type, 8, eui); 716 } 717 718 static void set_dev_addr(struct net_device *netdev, bdaddr_t *addr, 719 u8 addr_type) 720 { 721 netdev->addr_assign_type = NET_ADDR_PERM; 722 set_addr(netdev->dev_addr, addr->b, addr_type); 723 } 724 725 static void ifup(struct net_device *netdev) 726 { 727 int err; 728 729 rtnl_lock(); 730 err = dev_open(netdev); 731 if (err < 0) 732 BT_INFO("iface %s cannot be opened (%d)", netdev->name, err); 733 rtnl_unlock(); 734 } 735 736 static void ifdown(struct net_device *netdev) 737 { 738 int err; 739 740 rtnl_lock(); 741 err = dev_close(netdev); 742 if (err < 0) 743 BT_INFO("iface %s cannot be closed (%d)", netdev->name, err); 744 rtnl_unlock(); 745 } 746 747 static void do_notify_peers(struct work_struct *work) 748 { 749 struct lowpan_dev *dev = container_of(work, struct lowpan_dev, 750 notify_peers.work); 751 752 netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */ 753 } 754 755 static bool is_bt_6lowpan(struct hci_conn *hcon) 756 { 757 if (hcon->type != LE_LINK) 758 return false; 759 760 if (!enable_6lowpan) 761 return false; 762 763 return true; 764 } 765 766 static struct l2cap_chan *chan_create(void) 767 { 768 struct l2cap_chan *chan; 769 770 chan = l2cap_chan_create(); 771 if (!chan) 772 return NULL; 773 774 l2cap_chan_set_defaults(chan); 775 776 chan->chan_type = L2CAP_CHAN_CONN_ORIENTED; 777 chan->mode = L2CAP_MODE_LE_FLOWCTL; 778 chan->omtu = 65535; 779 chan->imtu = chan->omtu; 780 781 return chan; 782 } 783 784 static struct l2cap_chan *chan_open(struct l2cap_chan *pchan) 785 { 786 struct l2cap_chan *chan; 787 788 chan = chan_create(); 789 if (!chan) 790 return NULL; 791 792 chan->remote_mps = chan->omtu; 793 chan->mps = chan->omtu; 794 795 chan->state = BT_CONNECTED; 796 797 return chan; 798 } 799 800 static void set_ip_addr_bits(u8 addr_type, u8 *addr) 801 { 802 if (addr_type == BDADDR_LE_PUBLIC) 803 *addr |= 0x02; 804 else 805 *addr &= ~0x02; 806 } 807 808 static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan, 809 struct lowpan_dev *dev) 810 { 811 struct lowpan_peer *peer; 812 813 peer = kzalloc(sizeof(*peer), GFP_ATOMIC); 814 if (!peer) 815 return NULL; 816 817 peer->chan = chan; 818 memset(&peer->peer_addr, 0, sizeof(struct in6_addr)); 819 820 /* RFC 2464 ch. 5 */ 821 peer->peer_addr.s6_addr[0] = 0xFE; 822 peer->peer_addr.s6_addr[1] = 0x80; 823 set_addr((u8 *)&peer->peer_addr.s6_addr + 8, chan->dst.b, 824 chan->dst_type); 825 826 memcpy(&peer->eui64_addr, (u8 *)&peer->peer_addr.s6_addr + 8, 827 EUI64_ADDR_LEN); 828 829 /* IPv6 address needs to have the U/L bit set properly so toggle 830 * it back here. 831 */ 832 set_ip_addr_bits(chan->dst_type, (u8 *)&peer->peer_addr.s6_addr + 8); 833 834 spin_lock(&devices_lock); 835 INIT_LIST_HEAD(&peer->list); 836 peer_add(dev, peer); 837 spin_unlock(&devices_lock); 838 839 /* Notifying peers about us needs to be done without locks held */ 840 INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers); 841 schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100)); 842 843 return peer->chan; 844 } 845 846 static int setup_netdev(struct l2cap_chan *chan, struct lowpan_dev **dev) 847 { 848 struct net_device *netdev; 849 int err = 0; 850 851 netdev = alloc_netdev(sizeof(struct lowpan_dev), IFACE_NAME_TEMPLATE, 852 NET_NAME_UNKNOWN, netdev_setup); 853 if (!netdev) 854 return -ENOMEM; 855 856 set_dev_addr(netdev, &chan->src, chan->src_type); 857 858 netdev->netdev_ops = &netdev_ops; 859 SET_NETDEV_DEV(netdev, &chan->conn->hcon->hdev->dev); 860 SET_NETDEV_DEVTYPE(netdev, &bt_type); 861 862 err = register_netdev(netdev); 863 if (err < 0) { 864 BT_INFO("register_netdev failed %d", err); 865 free_netdev(netdev); 866 goto out; 867 } 868 869 BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d", 870 netdev->ifindex, &chan->dst, chan->dst_type, 871 &chan->src, chan->src_type); 872 set_bit(__LINK_STATE_PRESENT, &netdev->state); 873 874 *dev = netdev_priv(netdev); 875 (*dev)->netdev = netdev; 876 (*dev)->hdev = chan->conn->hcon->hdev; 877 INIT_LIST_HEAD(&(*dev)->peers); 878 879 spin_lock(&devices_lock); 880 INIT_LIST_HEAD(&(*dev)->list); 881 list_add_rcu(&(*dev)->list, &bt_6lowpan_devices); 882 spin_unlock(&devices_lock); 883 884 return 0; 885 886 out: 887 return err; 888 } 889 890 static inline void chan_ready_cb(struct l2cap_chan *chan) 891 { 892 struct lowpan_dev *dev; 893 894 dev = lookup_dev(chan->conn); 895 896 BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev); 897 898 if (!dev) { 899 if (setup_netdev(chan, &dev) < 0) { 900 l2cap_chan_del(chan, -ENOENT); 901 return; 902 } 903 } 904 905 if (!try_module_get(THIS_MODULE)) 906 return; 907 908 add_peer_chan(chan, dev); 909 ifup(dev->netdev); 910 } 911 912 static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan) 913 { 914 struct l2cap_chan *chan; 915 916 chan = chan_open(pchan); 917 chan->ops = pchan->ops; 918 919 BT_DBG("chan %p pchan %p", chan, pchan); 920 921 return chan; 922 } 923 924 static void delete_netdev(struct work_struct *work) 925 { 926 struct lowpan_dev *entry = container_of(work, struct lowpan_dev, 927 delete_netdev); 928 929 unregister_netdev(entry->netdev); 930 931 /* The entry pointer is deleted by the netdev destructor. */ 932 } 933 934 static void chan_close_cb(struct l2cap_chan *chan) 935 { 936 struct lowpan_dev *entry; 937 struct lowpan_dev *dev = NULL; 938 struct lowpan_peer *peer; 939 int err = -ENOENT; 940 bool last = false, remove = true; 941 942 BT_DBG("chan %p conn %p", chan, chan->conn); 943 944 if (chan->conn && chan->conn->hcon) { 945 if (!is_bt_6lowpan(chan->conn->hcon)) 946 return; 947 948 /* If conn is set, then the netdev is also there and we should 949 * not remove it. 950 */ 951 remove = false; 952 } 953 954 spin_lock(&devices_lock); 955 956 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 957 dev = lowpan_dev(entry->netdev); 958 peer = __peer_lookup_chan(dev, chan); 959 if (peer) { 960 last = peer_del(dev, peer); 961 err = 0; 962 963 BT_DBG("dev %p removing %speer %p", dev, 964 last ? "last " : "1 ", peer); 965 BT_DBG("chan %p orig refcnt %d", chan, 966 atomic_read(&chan->kref.refcount)); 967 968 l2cap_chan_put(chan); 969 break; 970 } 971 } 972 973 if (!err && last && dev && !atomic_read(&dev->peer_count)) { 974 spin_unlock(&devices_lock); 975 976 cancel_delayed_work_sync(&dev->notify_peers); 977 978 ifdown(dev->netdev); 979 980 if (remove) { 981 INIT_WORK(&entry->delete_netdev, delete_netdev); 982 schedule_work(&entry->delete_netdev); 983 } 984 } else { 985 spin_unlock(&devices_lock); 986 } 987 988 return; 989 } 990 991 static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err) 992 { 993 BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn, 994 state_to_string(state), err); 995 } 996 997 static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan, 998 unsigned long hdr_len, 999 unsigned long len, int nb) 1000 { 1001 /* Note that we must allocate using GFP_ATOMIC here as 1002 * this function is called originally from netdev hard xmit 1003 * function in atomic context. 1004 */ 1005 return bt_skb_alloc(hdr_len + len, GFP_ATOMIC); 1006 } 1007 1008 static void chan_suspend_cb(struct l2cap_chan *chan) 1009 { 1010 struct sk_buff *skb = chan->data; 1011 1012 BT_DBG("chan %p conn %p skb %p", chan, chan->conn, skb); 1013 1014 if (!skb) 1015 return; 1016 1017 lowpan_cb(skb)->status = -EAGAIN; 1018 } 1019 1020 static void chan_resume_cb(struct l2cap_chan *chan) 1021 { 1022 struct sk_buff *skb = chan->data; 1023 1024 BT_DBG("chan %p conn %p skb %p", chan, chan->conn, skb); 1025 1026 if (!skb) 1027 return; 1028 1029 lowpan_cb(skb)->status = 0; 1030 } 1031 1032 static long chan_get_sndtimeo_cb(struct l2cap_chan *chan) 1033 { 1034 return L2CAP_CONN_TIMEOUT; 1035 } 1036 1037 static const struct l2cap_ops bt_6lowpan_chan_ops = { 1038 .name = "L2CAP 6LoWPAN channel", 1039 .new_connection = chan_new_conn_cb, 1040 .recv = chan_recv_cb, 1041 .close = chan_close_cb, 1042 .state_change = chan_state_change_cb, 1043 .ready = chan_ready_cb, 1044 .resume = chan_resume_cb, 1045 .suspend = chan_suspend_cb, 1046 .get_sndtimeo = chan_get_sndtimeo_cb, 1047 .alloc_skb = chan_alloc_skb_cb, 1048 1049 .teardown = l2cap_chan_no_teardown, 1050 .defer = l2cap_chan_no_defer, 1051 .set_shutdown = l2cap_chan_no_set_shutdown, 1052 }; 1053 1054 static inline __u8 bdaddr_type(__u8 type) 1055 { 1056 if (type == ADDR_LE_DEV_PUBLIC) 1057 return BDADDR_LE_PUBLIC; 1058 else 1059 return BDADDR_LE_RANDOM; 1060 } 1061 1062 static struct l2cap_chan *chan_get(void) 1063 { 1064 struct l2cap_chan *pchan; 1065 1066 pchan = chan_create(); 1067 if (!pchan) 1068 return NULL; 1069 1070 pchan->ops = &bt_6lowpan_chan_ops; 1071 1072 return pchan; 1073 } 1074 1075 static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type) 1076 { 1077 struct l2cap_chan *pchan; 1078 int err; 1079 1080 pchan = chan_get(); 1081 if (!pchan) 1082 return -EINVAL; 1083 1084 err = l2cap_chan_connect(pchan, cpu_to_le16(L2CAP_PSM_IPSP), 0, 1085 addr, dst_type); 1086 1087 BT_DBG("chan %p err %d", pchan, err); 1088 if (err < 0) 1089 l2cap_chan_put(pchan); 1090 1091 return err; 1092 } 1093 1094 static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type) 1095 { 1096 struct lowpan_peer *peer; 1097 1098 BT_DBG("conn %p dst type %d", conn, dst_type); 1099 1100 peer = lookup_peer(conn); 1101 if (!peer) 1102 return -ENOENT; 1103 1104 BT_DBG("peer %p chan %p", peer, peer->chan); 1105 1106 l2cap_chan_close(peer->chan, ENOENT); 1107 1108 return 0; 1109 } 1110 1111 static struct l2cap_chan *bt_6lowpan_listen(void) 1112 { 1113 bdaddr_t *addr = BDADDR_ANY; 1114 struct l2cap_chan *pchan; 1115 int err; 1116 1117 if (!enable_6lowpan) 1118 return NULL; 1119 1120 pchan = chan_get(); 1121 if (!pchan) 1122 return NULL; 1123 1124 pchan->state = BT_LISTEN; 1125 pchan->src_type = BDADDR_LE_PUBLIC; 1126 1127 atomic_set(&pchan->nesting, L2CAP_NESTING_PARENT); 1128 1129 BT_DBG("chan %p src type %d", pchan, pchan->src_type); 1130 1131 err = l2cap_add_psm(pchan, addr, cpu_to_le16(L2CAP_PSM_IPSP)); 1132 if (err) { 1133 l2cap_chan_put(pchan); 1134 BT_ERR("psm cannot be added err %d", err); 1135 return NULL; 1136 } 1137 1138 return pchan; 1139 } 1140 1141 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type, 1142 struct l2cap_conn **conn) 1143 { 1144 struct hci_conn *hcon; 1145 struct hci_dev *hdev; 1146 bdaddr_t *src = BDADDR_ANY; 1147 int n; 1148 1149 n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu", 1150 &addr->b[5], &addr->b[4], &addr->b[3], 1151 &addr->b[2], &addr->b[1], &addr->b[0], 1152 addr_type); 1153 1154 if (n < 7) 1155 return -EINVAL; 1156 1157 hdev = hci_get_route(addr, src); 1158 if (!hdev) 1159 return -ENOENT; 1160 1161 hci_dev_lock(hdev); 1162 hcon = hci_conn_hash_lookup_ba(hdev, LE_LINK, addr); 1163 hci_dev_unlock(hdev); 1164 1165 if (!hcon) 1166 return -ENOENT; 1167 1168 *conn = (struct l2cap_conn *)hcon->l2cap_data; 1169 1170 BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type); 1171 1172 return 0; 1173 } 1174 1175 static void disconnect_all_peers(void) 1176 { 1177 struct lowpan_dev *entry; 1178 struct lowpan_peer *peer, *tmp_peer, *new_peer; 1179 struct list_head peers; 1180 1181 INIT_LIST_HEAD(&peers); 1182 1183 /* We make a separate list of peers as the close_cb() will 1184 * modify the device peers list so it is better not to mess 1185 * with the same list at the same time. 1186 */ 1187 1188 rcu_read_lock(); 1189 1190 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 1191 list_for_each_entry_rcu(peer, &entry->peers, list) { 1192 new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC); 1193 if (!new_peer) 1194 break; 1195 1196 new_peer->chan = peer->chan; 1197 INIT_LIST_HEAD(&new_peer->list); 1198 1199 list_add(&new_peer->list, &peers); 1200 } 1201 } 1202 1203 rcu_read_unlock(); 1204 1205 spin_lock(&devices_lock); 1206 list_for_each_entry_safe(peer, tmp_peer, &peers, list) { 1207 l2cap_chan_close(peer->chan, ENOENT); 1208 1209 list_del_rcu(&peer->list); 1210 kfree_rcu(peer, rcu); 1211 } 1212 spin_unlock(&devices_lock); 1213 } 1214 1215 struct set_enable { 1216 struct work_struct work; 1217 bool flag; 1218 }; 1219 1220 static void do_enable_set(struct work_struct *work) 1221 { 1222 struct set_enable *set_enable = container_of(work, 1223 struct set_enable, work); 1224 1225 if (!set_enable->flag || enable_6lowpan != set_enable->flag) 1226 /* Disconnect existing connections if 6lowpan is 1227 * disabled 1228 */ 1229 disconnect_all_peers(); 1230 1231 enable_6lowpan = set_enable->flag; 1232 1233 if (listen_chan) { 1234 l2cap_chan_close(listen_chan, 0); 1235 l2cap_chan_put(listen_chan); 1236 } 1237 1238 listen_chan = bt_6lowpan_listen(); 1239 1240 kfree(set_enable); 1241 } 1242 1243 static int lowpan_enable_set(void *data, u64 val) 1244 { 1245 struct set_enable *set_enable; 1246 1247 set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL); 1248 if (!set_enable) 1249 return -ENOMEM; 1250 1251 set_enable->flag = !!val; 1252 INIT_WORK(&set_enable->work, do_enable_set); 1253 1254 schedule_work(&set_enable->work); 1255 1256 return 0; 1257 } 1258 1259 static int lowpan_enable_get(void *data, u64 *val) 1260 { 1261 *val = enable_6lowpan; 1262 return 0; 1263 } 1264 1265 DEFINE_SIMPLE_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get, 1266 lowpan_enable_set, "%llu\n"); 1267 1268 static ssize_t lowpan_control_write(struct file *fp, 1269 const char __user *user_buffer, 1270 size_t count, 1271 loff_t *position) 1272 { 1273 char buf[32]; 1274 size_t buf_size = min(count, sizeof(buf) - 1); 1275 int ret; 1276 bdaddr_t addr; 1277 u8 addr_type; 1278 struct l2cap_conn *conn = NULL; 1279 1280 if (copy_from_user(buf, user_buffer, buf_size)) 1281 return -EFAULT; 1282 1283 buf[buf_size] = '\0'; 1284 1285 if (memcmp(buf, "connect ", 8) == 0) { 1286 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn); 1287 if (ret == -EINVAL) 1288 return ret; 1289 1290 if (listen_chan) { 1291 l2cap_chan_close(listen_chan, 0); 1292 l2cap_chan_put(listen_chan); 1293 listen_chan = NULL; 1294 } 1295 1296 if (conn) { 1297 struct lowpan_peer *peer; 1298 1299 if (!is_bt_6lowpan(conn->hcon)) 1300 return -EINVAL; 1301 1302 peer = lookup_peer(conn); 1303 if (peer) { 1304 BT_DBG("6LoWPAN connection already exists"); 1305 return -EALREADY; 1306 } 1307 1308 BT_DBG("conn %p dst %pMR type %d user %d", conn, 1309 &conn->hcon->dst, conn->hcon->dst_type, 1310 addr_type); 1311 } 1312 1313 ret = bt_6lowpan_connect(&addr, addr_type); 1314 if (ret < 0) 1315 return ret; 1316 1317 return count; 1318 } 1319 1320 if (memcmp(buf, "disconnect ", 11) == 0) { 1321 ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn); 1322 if (ret < 0) 1323 return ret; 1324 1325 ret = bt_6lowpan_disconnect(conn, addr_type); 1326 if (ret < 0) 1327 return ret; 1328 1329 return count; 1330 } 1331 1332 return count; 1333 } 1334 1335 static int lowpan_control_show(struct seq_file *f, void *ptr) 1336 { 1337 struct lowpan_dev *entry; 1338 struct lowpan_peer *peer; 1339 1340 spin_lock(&devices_lock); 1341 1342 list_for_each_entry(entry, &bt_6lowpan_devices, list) { 1343 list_for_each_entry(peer, &entry->peers, list) 1344 seq_printf(f, "%pMR (type %u)\n", 1345 &peer->chan->dst, peer->chan->dst_type); 1346 } 1347 1348 spin_unlock(&devices_lock); 1349 1350 return 0; 1351 } 1352 1353 static int lowpan_control_open(struct inode *inode, struct file *file) 1354 { 1355 return single_open(file, lowpan_control_show, inode->i_private); 1356 } 1357 1358 static const struct file_operations lowpan_control_fops = { 1359 .open = lowpan_control_open, 1360 .read = seq_read, 1361 .write = lowpan_control_write, 1362 .llseek = seq_lseek, 1363 .release = single_release, 1364 }; 1365 1366 static void disconnect_devices(void) 1367 { 1368 struct lowpan_dev *entry, *tmp, *new_dev; 1369 struct list_head devices; 1370 1371 INIT_LIST_HEAD(&devices); 1372 1373 /* We make a separate list of devices because the unregister_netdev() 1374 * will call device_event() which will also want to modify the same 1375 * devices list. 1376 */ 1377 1378 rcu_read_lock(); 1379 1380 list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) { 1381 new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC); 1382 if (!new_dev) 1383 break; 1384 1385 new_dev->netdev = entry->netdev; 1386 INIT_LIST_HEAD(&new_dev->list); 1387 1388 list_add_rcu(&new_dev->list, &devices); 1389 } 1390 1391 rcu_read_unlock(); 1392 1393 list_for_each_entry_safe(entry, tmp, &devices, list) { 1394 ifdown(entry->netdev); 1395 BT_DBG("Unregistering netdev %s %p", 1396 entry->netdev->name, entry->netdev); 1397 unregister_netdev(entry->netdev); 1398 kfree(entry); 1399 } 1400 } 1401 1402 static int device_event(struct notifier_block *unused, 1403 unsigned long event, void *ptr) 1404 { 1405 struct net_device *netdev = netdev_notifier_info_to_dev(ptr); 1406 struct lowpan_dev *entry; 1407 1408 if (netdev->type != ARPHRD_6LOWPAN) 1409 return NOTIFY_DONE; 1410 1411 switch (event) { 1412 case NETDEV_UNREGISTER: 1413 spin_lock(&devices_lock); 1414 list_for_each_entry(entry, &bt_6lowpan_devices, list) { 1415 if (entry->netdev == netdev) { 1416 BT_DBG("Unregistered netdev %s %p", 1417 netdev->name, netdev); 1418 list_del(&entry->list); 1419 break; 1420 } 1421 } 1422 spin_unlock(&devices_lock); 1423 break; 1424 } 1425 1426 return NOTIFY_DONE; 1427 } 1428 1429 static struct notifier_block bt_6lowpan_dev_notifier = { 1430 .notifier_call = device_event, 1431 }; 1432 1433 static int __init bt_6lowpan_init(void) 1434 { 1435 lowpan_enable_debugfs = debugfs_create_file("6lowpan_enable", 0644, 1436 bt_debugfs, NULL, 1437 &lowpan_enable_fops); 1438 lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644, 1439 bt_debugfs, NULL, 1440 &lowpan_control_fops); 1441 1442 return register_netdevice_notifier(&bt_6lowpan_dev_notifier); 1443 } 1444 1445 static void __exit bt_6lowpan_exit(void) 1446 { 1447 debugfs_remove(lowpan_enable_debugfs); 1448 debugfs_remove(lowpan_control_debugfs); 1449 1450 if (listen_chan) { 1451 l2cap_chan_close(listen_chan, 0); 1452 l2cap_chan_put(listen_chan); 1453 } 1454 1455 disconnect_devices(); 1456 1457 unregister_netdevice_notifier(&bt_6lowpan_dev_notifier); 1458 } 1459 1460 module_init(bt_6lowpan_init); 1461 module_exit(bt_6lowpan_exit); 1462 1463 MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>"); 1464 MODULE_DESCRIPTION("Bluetooth 6LoWPAN"); 1465 MODULE_VERSION(VERSION); 1466 MODULE_LICENSE("GPL"); 1467