net/bluetooth/6lowpan.c

   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 static DEFINE_MUTEX(set_lock);
  61
  62 struct lowpan_peer {
  63         struct list_head list;
  64         struct rcu_head rcu;
  65         struct l2cap_chan *chan;
  66
  67         /* peer addresses in various formats */
  68         unsigned char eui64_addr[EUI64_ADDR_LEN];
  69         struct in6_addr peer_addr;
  70 };
  71
  72 struct lowpan_dev {
  73         struct list_head list;
  74
  75         struct hci_dev *hdev;
  76         struct net_device *netdev;
  77         struct list_head peers;
  78         atomic_t peer_count; /* number of items in peers list */
  79
  80         struct work_struct delete_netdev;
  81         struct delayed_work notify_peers;
  82 };
  83
  84 static inline struct lowpan_dev *lowpan_dev(const struct net_device *netdev)
  85 {
  86         return (struct lowpan_dev *)lowpan_priv(netdev)->priv;
  87 }
  88
  89 static inline void peer_add(struct lowpan_dev *dev, struct lowpan_peer *peer)
  90 {
  91         list_add_rcu(&peer->list, &dev->peers);
  92         atomic_inc(&dev->peer_count);
  93 }
  94
  95 static inline bool peer_del(struct lowpan_dev *dev, struct lowpan_peer *peer)
  96 {
  97         list_del_rcu(&peer->list);
  98         kfree_rcu(peer, rcu);
  99
 100         module_put(THIS_MODULE);
 101
 102         if (atomic_dec_and_test(&dev->peer_count)) {
 103                 BT_DBG("last peer");
 104                 return true;
 105         }
 106
 107         return false;
 108 }
 109
 110 static inline struct lowpan_peer *peer_lookup_ba(struct lowpan_dev *dev,
 111                                                  bdaddr_t *ba, __u8 type)
 112 {
 113         struct lowpan_peer *peer;
 114
 115         BT_DBG("peers %d addr %pMR type %d", atomic_read(&dev->peer_count),
 116                ba, type);
 117
 118         rcu_read_lock();
 119
 120         list_for_each_entry_rcu(peer, &dev->peers, list) {
 121                 BT_DBG("dst addr %pMR dst type %d",
 122                        &peer->chan->dst, peer->chan->dst_type);
 123
 124                 if (bacmp(&peer->chan->dst, ba))
 125                         continue;
 126
 127                 if (type == peer->chan->dst_type) {
 128                         rcu_read_unlock();
 129                         return peer;
 130                 }
 131         }
 132
 133         rcu_read_unlock();
 134
 135         return NULL;
 136 }
 137
 138 static inline struct lowpan_peer *__peer_lookup_chan(struct lowpan_dev *dev,
 139                                                      struct l2cap_chan *chan)
 140 {
 141         struct lowpan_peer *peer;
 142
 143         list_for_each_entry_rcu(peer, &dev->peers, list) {
 144                 if (peer->chan == chan)
 145                         return peer;
 146         }
 147
 148         return NULL;
 149 }
 150
 151 static inline struct lowpan_peer *__peer_lookup_conn(struct lowpan_dev *dev,
 152                                                      struct l2cap_conn *conn)
 153 {
 154         struct lowpan_peer *peer;
 155
 156         list_for_each_entry_rcu(peer, &dev->peers, list) {
 157                 if (peer->chan->conn == conn)
 158                         return peer;
 159         }
 160
 161         return NULL;
 162 }
 163
 164 static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_dev *dev,
 165                                                   struct in6_addr *daddr,
 166                                                   struct sk_buff *skb)
 167 {
 168         struct lowpan_peer *peer;
 169         struct in6_addr *nexthop;
 170         struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
 171         int count = atomic_read(&dev->peer_count);
 172
 173         BT_DBG("peers %d addr %pI6c rt %p", count, daddr, rt);
 174
 175         /* If we have multiple 6lowpan peers, then check where we should
 176          * send the packet. If only one peer exists, then we can send the
 177          * packet right away.
 178          */
 179         if (count == 1) {
 180                 rcu_read_lock();
 181                 peer = list_first_or_null_rcu(&dev->peers, struct lowpan_peer,
 182                                               list);
 183                 rcu_read_unlock();
 184                 return peer;
 185         }
 186
 187         if (!rt) {
 188                 if (ipv6_addr_any(&lowpan_cb(skb)->gw)) {
 189                         /* There is neither route nor gateway,
 190                          * probably the destination is a direct peer.
 191                          */
 192                         nexthop = daddr;
 193                 } else {
 194                         /* There is a known gateway
 195                          */
 196                         nexthop = &lowpan_cb(skb)->gw;
 197                 }
 198         } else {
 199                 nexthop = rt6_nexthop(rt, daddr);
 200
 201                 /* We need to remember the address because it is needed
 202                  * by bt_xmit() when sending the packet. In bt_xmit(), the
 203                  * destination routing info is not set.
 204                  */
 205                 memcpy(&lowpan_cb(skb)->gw, nexthop, sizeof(struct in6_addr));
 206         }
 207
 208         BT_DBG("gw %pI6c", nexthop);
 209
 210         rcu_read_lock();
 211
 212         list_for_each_entry_rcu(peer, &dev->peers, list) {
 213                 BT_DBG("dst addr %pMR dst type %d ip %pI6c",
 214                        &peer->chan->dst, peer->chan->dst_type,
 215                        &peer->peer_addr);
 216
 217                 if (!ipv6_addr_cmp(&peer->peer_addr, nexthop)) {
 218                         rcu_read_unlock();
 219                         return peer;
 220                 }
 221         }
 222
 223         rcu_read_unlock();
 224
 225         return NULL;
 226 }
 227
 228 static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn)
 229 {
 230         struct lowpan_dev *entry;
 231         struct lowpan_peer *peer = NULL;
 232
 233         rcu_read_lock();
 234
 235         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 236                 peer = __peer_lookup_conn(entry, conn);
 237                 if (peer)
 238                         break;
 239         }
 240
 241         rcu_read_unlock();
 242
 243         return peer;
 244 }
 245
 246 static struct lowpan_dev *lookup_dev(struct l2cap_conn *conn)
 247 {
 248         struct lowpan_dev *entry;
 249         struct lowpan_dev *dev = NULL;
 250
 251         rcu_read_lock();
 252
 253         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 254                 if (conn->hcon->hdev == entry->hdev) {
 255                         dev = entry;
 256                         break;
 257                 }
 258         }
 259
 260         rcu_read_unlock();
 261
 262         return dev;
 263 }
 264
 265 static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev)
 266 {
 267         struct sk_buff *skb_cp;
 268
 269         skb_cp = skb_copy(skb, GFP_ATOMIC);
 270         if (!skb_cp)
 271                 return NET_RX_DROP;
 272
 273         return netif_rx_ni(skb_cp);
 274 }
 275
 276 static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev,
 277                            struct l2cap_chan *chan)
 278 {
 279         const u8 *saddr, *daddr;
 280         struct lowpan_dev *dev;
 281         struct lowpan_peer *peer;
 282
 283         dev = lowpan_dev(netdev);
 284
 285         rcu_read_lock();
 286         peer = __peer_lookup_chan(dev, chan);
 287         rcu_read_unlock();
 288         if (!peer)
 289                 return -EINVAL;
 290
 291         saddr = peer->eui64_addr;
 292         daddr = dev->netdev->dev_addr;
 293
 294         return lowpan_header_decompress(skb, netdev, daddr, saddr);
 295 }
 296
 297 static int recv_pkt(struct sk_buff *skb, struct net_device *dev,
 298                     struct l2cap_chan *chan)
 299 {
 300         struct sk_buff *local_skb;
 301         int ret;
 302
 303         if (!netif_running(dev))
 304                 goto drop;
 305
 306         if (dev->type != ARPHRD_6LOWPAN || !skb->len)
 307                 goto drop;
 308
 309         skb_reset_network_header(skb);
 310
 311         skb = skb_share_check(skb, GFP_ATOMIC);
 312         if (!skb)
 313                 goto drop;
 314
 315         /* check that it's our buffer */
 316         if (lowpan_is_ipv6(*skb_network_header(skb))) {
 317                 /* Pull off the 1-byte of 6lowpan header. */
 318                 skb_pull(skb, 1);
 319
 320                 /* Copy the packet so that the IPv6 header is
 321                  * properly aligned.
 322                  */
 323                 local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
 324                                             skb_tailroom(skb), GFP_ATOMIC);
 325                 if (!local_skb)
 326                         goto drop;
 327
 328                 local_skb->protocol = htons(ETH_P_IPV6);
 329                 local_skb->pkt_type = PACKET_HOST;
 330                 local_skb->dev = dev;
 331
 332                 skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
 333
 334                 if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) {
 335                         kfree_skb(local_skb);
 336                         goto drop;
 337                 }
 338
 339                 dev->stats.rx_bytes += skb->len;
 340                 dev->stats.rx_packets++;
 341
 342                 consume_skb(local_skb);
 343                 consume_skb(skb);
 344         } else if (lowpan_is_iphc(*skb_network_header(skb))) {
 345                 local_skb = skb_clone(skb, GFP_ATOMIC);
 346                 if (!local_skb)
 347                         goto drop;
 348
 349                 local_skb->dev = dev;
 350
 351                 ret = iphc_decompress(local_skb, dev, chan);
 352                 if (ret < 0) {
 353                         kfree_skb(local_skb);
 354                         goto drop;
 355                 }
 356
 357                 local_skb->protocol = htons(ETH_P_IPV6);
 358                 local_skb->pkt_type = PACKET_HOST;
 359
 360                 if (give_skb_to_upper(local_skb, dev)
 361                                 != NET_RX_SUCCESS) {
 362                         kfree_skb(local_skb);
 363                         goto drop;
 364                 }
 365
 366                 dev->stats.rx_bytes += skb->len;
 367                 dev->stats.rx_packets++;
 368
 369                 consume_skb(local_skb);
 370                 consume_skb(skb);
 371         } else {
 372                 goto drop;
 373         }
 374
 375         return NET_RX_SUCCESS;
 376
 377 drop:
 378         dev->stats.rx_dropped++;
 379         return NET_RX_DROP;
 380 }
 381
 382 /* Packet from BT LE device */
 383 static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
 384 {
 385         struct lowpan_dev *dev;
 386         struct lowpan_peer *peer;
 387         int err;
 388
 389         peer = lookup_peer(chan->conn);
 390         if (!peer)
 391                 return -ENOENT;
 392
 393         dev = lookup_dev(chan->conn);
 394         if (!dev || !dev->netdev)
 395                 return -ENOENT;
 396
 397         err = recv_pkt(skb, dev->netdev, chan);
 398         if (err) {
 399                 BT_DBG("recv pkt %d", err);
 400                 err = -EAGAIN;
 401         }
 402
 403         return err;
 404 }
 405
 406 static u8 get_addr_type_from_eui64(u8 byte)
 407 {
 408         /* Is universal(0) or local(1) bit */
 409         return ((byte & 0x02) ? BDADDR_LE_RANDOM : BDADDR_LE_PUBLIC);
 410 }
 411
 412 static void copy_to_bdaddr(struct in6_addr *ip6_daddr, bdaddr_t *addr)
 413 {
 414         u8 *eui64 = ip6_daddr->s6_addr + 8;
 415
 416         addr->b[0] = eui64[7];
 417         addr->b[1] = eui64[6];
 418         addr->b[2] = eui64[5];
 419         addr->b[3] = eui64[2];
 420         addr->b[4] = eui64[1];
 421         addr->b[5] = eui64[0];
 422 }
 423
 424 static void convert_dest_bdaddr(struct in6_addr *ip6_daddr,
 425                                 bdaddr_t *addr, u8 *addr_type)
 426 {
 427         copy_to_bdaddr(ip6_daddr, addr);
 428
 429         /* We need to toggle the U/L bit that we got from IPv6 address
 430          * so that we get the proper address and type of the BD address.
 431          */
 432         addr->b[5] ^= 0x02;
 433
 434         *addr_type = get_addr_type_from_eui64(addr->b[5]);
 435 }
 436
 437 static int setup_header(struct sk_buff *skb, struct net_device *netdev,
 438                         bdaddr_t *peer_addr, u8 *peer_addr_type)
 439 {
 440         struct in6_addr ipv6_daddr;
 441         struct lowpan_dev *dev;
 442         struct lowpan_peer *peer;
 443         bdaddr_t addr, *any = BDADDR_ANY;
 444         u8 *daddr = any->b;
 445         int err, status = 0;
 446
 447         dev = lowpan_dev(netdev);
 448
 449         memcpy(&ipv6_daddr, &lowpan_cb(skb)->addr, sizeof(ipv6_daddr));
 450
 451         if (ipv6_addr_is_multicast(&ipv6_daddr)) {
 452                 lowpan_cb(skb)->chan = NULL;
 453         } else {
 454                 u8 addr_type;
 455
 456                 /* Get destination BT device from skb.
 457                  * If there is no such peer then discard the packet.
 458                  */
 459                 convert_dest_bdaddr(&ipv6_daddr, &addr, &addr_type);
 460
 461                 BT_DBG("dest addr %pMR type %d IP %pI6c", &addr,
 462                        addr_type, &ipv6_daddr);
 463
 464                 peer = peer_lookup_ba(dev, &addr, addr_type);
 465                 if (!peer) {
 466                         /* The packet might be sent to 6lowpan interface
 467                          * because of routing (either via default route
 468                          * or user set route) so get peer according to
 469                          * the destination address.
 470                          */
 471                         peer = peer_lookup_dst(dev, &ipv6_daddr, skb);
 472                         if (!peer) {
 473                                 BT_DBG("no such peer %pMR found", &addr);
 474                                 return -ENOENT;
 475                         }
 476                 }
 477
 478                 daddr = peer->eui64_addr;
 479                 *peer_addr = addr;
 480                 *peer_addr_type = addr_type;
 481                 lowpan_cb(skb)->chan = peer->chan;
 482
 483                 status = 1;
 484         }
 485
 486         lowpan_header_compress(skb, netdev, daddr, dev->netdev->dev_addr);
 487
 488         err = dev_hard_header(skb, netdev, ETH_P_IPV6, NULL, NULL, 0);
 489         if (err < 0)
 490                 return err;
 491
 492         return status;
 493 }
 494
 495 static int header_create(struct sk_buff *skb, struct net_device *netdev,
 496                          unsigned short type, const void *_daddr,
 497                          const void *_saddr, unsigned int len)
 498 {
 499         struct ipv6hdr *hdr;
 500
 501         if (type != ETH_P_IPV6)
 502                 return -EINVAL;
 503
 504         hdr = ipv6_hdr(skb);
 505
 506         memcpy(&lowpan_cb(skb)->addr, &hdr->daddr, sizeof(struct in6_addr));
 507
 508         return 0;
 509 }
 510
 511 /* Packet to BT LE device */
 512 static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb,
 513                     struct net_device *netdev)
 514 {
 515         struct msghdr msg;
 516         struct kvec iv;
 517         int err;
 518
 519         /* Remember the skb so that we can send EAGAIN to the caller if
 520          * we run out of credits.
 521          */
 522         chan->data = skb;
 523
 524         iv.iov_base = skb->data;
 525         iv.iov_len = skb->len;
 526
 527         memset(&msg, 0, sizeof(msg));
 528         iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, &iv, 1, skb->len);
 529
 530         err = l2cap_chan_send(chan, &msg, skb->len);
 531         if (err > 0) {
 532                 netdev->stats.tx_bytes += err;
 533                 netdev->stats.tx_packets++;
 534                 return 0;
 535         }
 536
 537         if (!err)
 538                 err = lowpan_cb(skb)->status;
 539
 540         if (err < 0) {
 541                 if (err == -EAGAIN)
 542                         netdev->stats.tx_dropped++;
 543                 else
 544                         netdev->stats.tx_errors++;
 545         }
 546
 547         return err;
 548 }
 549
 550 static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev)
 551 {
 552         struct sk_buff *local_skb;
 553         struct lowpan_dev *entry;
 554         int err = 0;
 555
 556         rcu_read_lock();
 557
 558         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 559                 struct lowpan_peer *pentry;
 560                 struct lowpan_dev *dev;
 561
 562                 if (entry->netdev != netdev)
 563                         continue;
 564
 565                 dev = lowpan_dev(entry->netdev);
 566
 567                 list_for_each_entry_rcu(pentry, &dev->peers, list) {
 568                         int ret;
 569
 570                         local_skb = skb_clone(skb, GFP_ATOMIC);
 571
 572                         BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
 573                                netdev->name,
 574                                &pentry->chan->dst, pentry->chan->dst_type,
 575                                &pentry->peer_addr, pentry->chan);
 576                         ret = send_pkt(pentry->chan, local_skb, netdev);
 577                         if (ret < 0)
 578                                 err = ret;
 579
 580                         kfree_skb(local_skb);
 581                 }
 582         }
 583
 584         rcu_read_unlock();
 585
 586         return err;
 587 }
 588
 589 static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev)
 590 {
 591         int err = 0;
 592         bdaddr_t addr;
 593         u8 addr_type;
 594
 595         /* We must take a copy of the skb before we modify/replace the ipv6
 596          * header as the header could be used elsewhere
 597          */
 598         skb = skb_unshare(skb, GFP_ATOMIC);
 599         if (!skb)
 600                 return NET_XMIT_DROP;
 601
 602         /* Return values from setup_header()
 603          *  <0 - error, packet is dropped
 604          *   0 - this is a multicast packet
 605          *   1 - this is unicast packet
 606          */
 607         err = setup_header(skb, netdev, &addr, &addr_type);
 608         if (err < 0) {
 609                 kfree_skb(skb);
 610                 return NET_XMIT_DROP;
 611         }
 612
 613         if (err) {
 614                 if (lowpan_cb(skb)->chan) {
 615                         BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
 616                                netdev->name, &addr, addr_type,
 617                                &lowpan_cb(skb)->addr, lowpan_cb(skb)->chan);
 618                         err = send_pkt(lowpan_cb(skb)->chan, skb, netdev);
 619                 } else {
 620                         err = -ENOENT;
 621                 }
 622         } else {
 623                 /* We need to send the packet to every device behind this
 624                  * interface.
 625                  */
 626                 err = send_mcast_pkt(skb, netdev);
 627         }
 628
 629         dev_kfree_skb(skb);
 630
 631         if (err)
 632                 BT_DBG("ERROR: xmit failed (%d)", err);
 633
 634         return err < 0 ? NET_XMIT_DROP : err;
 635 }
 636
 637 static struct lock_class_key bt_tx_busylock;
 638 static struct lock_class_key bt_netdev_xmit_lock_key;
 639
 640 static void bt_set_lockdep_class_one(struct net_device *dev,
 641                                      struct netdev_queue *txq,
 642                                      void *_unused)
 643 {
 644         lockdep_set_class(&txq->_xmit_lock, &bt_netdev_xmit_lock_key);
 645 }
 646
 647 static int bt_dev_init(struct net_device *dev)
 648 {
 649         netdev_for_each_tx_queue(dev, bt_set_lockdep_class_one, NULL);
 650         dev->qdisc_tx_busylock = &bt_tx_busylock;
 651
 652         return 0;
 653 }
 654
 655 static const struct net_device_ops netdev_ops = {
 656         .ndo_init               = bt_dev_init,
 657         .ndo_start_xmit         = bt_xmit,
 658 };
 659
 660 static struct header_ops header_ops = {
 661         .create = header_create,
 662 };
 663
 664 static void netdev_setup(struct net_device *dev)
 665 {
 666         dev->hard_header_len    = 0;
 667         dev->needed_tailroom    = 0;
 668         dev->flags              = IFF_RUNNING | IFF_POINTOPOINT |
 669                                   IFF_MULTICAST;
 670         dev->watchdog_timeo     = 0;
 671
 672         dev->netdev_ops         = &netdev_ops;
 673         dev->header_ops         = &header_ops;
 674         dev->destructor         = free_netdev;
 675 }
 676
 677 static struct device_type bt_type = {
 678         .name   = "bluetooth",
 679 };
 680
 681 static void set_addr(u8 *eui, u8 *addr, u8 addr_type)
 682 {
 683         /* addr is the BT address in little-endian format */
 684         eui[0] = addr[5];
 685         eui[1] = addr[4];
 686         eui[2] = addr[3];
 687         eui[3] = 0xFF;
 688         eui[4] = 0xFE;
 689         eui[5] = addr[2];
 690         eui[6] = addr[1];
 691         eui[7] = addr[0];
 692
 693         /* Universal/local bit set, BT 6lowpan draft ch. 3.2.1 */
 694         if (addr_type == BDADDR_LE_PUBLIC)
 695                 eui[0] &= ~0x02;
 696         else
 697                 eui[0] |= 0x02;
 698
 699         BT_DBG("type %d addr %*phC", addr_type, 8, eui);
 700 }
 701
 702 static void set_dev_addr(struct net_device *netdev, bdaddr_t *addr,
 703                          u8 addr_type)
 704 {
 705         netdev->addr_assign_type = NET_ADDR_PERM;
 706         set_addr(netdev->dev_addr, addr->b, addr_type);
 707 }
 708
 709 static void ifup(struct net_device *netdev)
 710 {
 711         int err;
 712
 713         rtnl_lock();
 714         err = dev_open(netdev);
 715         if (err < 0)
 716                 BT_INFO("iface %s cannot be opened (%d)", netdev->name, err);
 717         rtnl_unlock();
 718 }
 719
 720 static void ifdown(struct net_device *netdev)
 721 {
 722         int err;
 723
 724         rtnl_lock();
 725         err = dev_close(netdev);
 726         if (err < 0)
 727                 BT_INFO("iface %s cannot be closed (%d)", netdev->name, err);
 728         rtnl_unlock();
 729 }
 730
 731 static void do_notify_peers(struct work_struct *work)
 732 {
 733         struct lowpan_dev *dev = container_of(work, struct lowpan_dev,
 734                                               notify_peers.work);
 735
 736         netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */
 737 }
 738
 739 static bool is_bt_6lowpan(struct hci_conn *hcon)
 740 {
 741         if (hcon->type != LE_LINK)
 742                 return false;
 743
 744         if (!enable_6lowpan)
 745                 return false;
 746
 747         return true;
 748 }
 749
 750 static struct l2cap_chan *chan_create(void)
 751 {
 752         struct l2cap_chan *chan;
 753
 754         chan = l2cap_chan_create();
 755         if (!chan)
 756                 return NULL;
 757
 758         l2cap_chan_set_defaults(chan);
 759
 760         chan->chan_type = L2CAP_CHAN_CONN_ORIENTED;
 761         chan->mode = L2CAP_MODE_LE_FLOWCTL;
 762         chan->imtu = 1280;
 763
 764         return chan;
 765 }
 766
 767 static void set_ip_addr_bits(u8 addr_type, u8 *addr)
 768 {
 769         if (addr_type == BDADDR_LE_PUBLIC)
 770                 *addr |= 0x02;
 771         else
 772                 *addr &= ~0x02;
 773 }
 774
 775 static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan,
 776                                         struct lowpan_dev *dev)
 777 {
 778         struct lowpan_peer *peer;
 779
 780         peer = kzalloc(sizeof(*peer), GFP_ATOMIC);
 781         if (!peer)
 782                 return NULL;
 783
 784         peer->chan = chan;
 785         memset(&peer->peer_addr, 0, sizeof(struct in6_addr));
 786
 787         /* RFC 2464 ch. 5 */
 788         peer->peer_addr.s6_addr[0] = 0xFE;
 789         peer->peer_addr.s6_addr[1] = 0x80;
 790         set_addr((u8 *)&peer->peer_addr.s6_addr + 8, chan->dst.b,
 791                  chan->dst_type);
 792
 793         memcpy(&peer->eui64_addr, (u8 *)&peer->peer_addr.s6_addr + 8,
 794                EUI64_ADDR_LEN);
 795
 796         /* IPv6 address needs to have the U/L bit set properly so toggle
 797          * it back here.
 798          */
 799         set_ip_addr_bits(chan->dst_type, (u8 *)&peer->peer_addr.s6_addr + 8);
 800
 801         spin_lock(&devices_lock);
 802         INIT_LIST_HEAD(&peer->list);
 803         peer_add(dev, peer);
 804         spin_unlock(&devices_lock);
 805
 806         /* Notifying peers about us needs to be done without locks held */
 807         INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers);
 808         schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100));
 809
 810         return peer->chan;
 811 }
 812
 813 static int setup_netdev(struct l2cap_chan *chan, struct lowpan_dev **dev)
 814 {
 815         struct net_device *netdev;
 816         int err = 0;
 817
 818         netdev = alloc_netdev(LOWPAN_PRIV_SIZE(sizeof(struct lowpan_dev)),
 819                               IFACE_NAME_TEMPLATE, NET_NAME_UNKNOWN,
 820                               netdev_setup);
 821         if (!netdev)
 822                 return -ENOMEM;
 823
 824         set_dev_addr(netdev, &chan->src, chan->src_type);
 825
 826         netdev->netdev_ops = &netdev_ops;
 827         SET_NETDEV_DEV(netdev, &chan->conn->hcon->hdev->dev);
 828         SET_NETDEV_DEVTYPE(netdev, &bt_type);
 829
 830         *dev = lowpan_dev(netdev);
 831         (*dev)->netdev = netdev;
 832         (*dev)->hdev = chan->conn->hcon->hdev;
 833         INIT_LIST_HEAD(&(*dev)->peers);
 834
 835         spin_lock(&devices_lock);
 836         INIT_LIST_HEAD(&(*dev)->list);
 837         list_add_rcu(&(*dev)->list, &bt_6lowpan_devices);
 838         spin_unlock(&devices_lock);
 839
 840         lowpan_netdev_setup(netdev, LOWPAN_LLTYPE_BTLE);
 841
 842         err = register_netdev(netdev);
 843         if (err < 0) {
 844                 BT_INFO("register_netdev failed %d", err);
 845                 spin_lock(&devices_lock);
 846                 list_del_rcu(&(*dev)->list);
 847                 spin_unlock(&devices_lock);
 848                 free_netdev(netdev);
 849                 goto out;
 850         }
 851
 852         BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d",
 853                netdev->ifindex, &chan->dst, chan->dst_type,
 854                &chan->src, chan->src_type);
 855         set_bit(__LINK_STATE_PRESENT, &netdev->state);
 856
 857         return 0;
 858
 859 out:
 860         return err;
 861 }
 862
 863 static inline void chan_ready_cb(struct l2cap_chan *chan)
 864 {
 865         struct lowpan_dev *dev;
 866
 867         dev = lookup_dev(chan->conn);
 868
 869         BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev);
 870
 871         if (!dev) {
 872                 if (setup_netdev(chan, &dev) < 0) {
 873                         l2cap_chan_del(chan, -ENOENT);
 874                         return;
 875                 }
 876         }
 877
 878         if (!try_module_get(THIS_MODULE))
 879                 return;
 880
 881         add_peer_chan(chan, dev);
 882         ifup(dev->netdev);
 883 }
 884
 885 static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan)
 886 {
 887         struct l2cap_chan *chan;
 888
 889         chan = chan_create();
 890         if (!chan)
 891                 return NULL;
 892
 893         chan->ops = pchan->ops;
 894
 895         BT_DBG("chan %p pchan %p", chan, pchan);
 896
 897         return chan;
 898 }
 899
 900 static void delete_netdev(struct work_struct *work)
 901 {
 902         struct lowpan_dev *entry = container_of(work, struct lowpan_dev,
 903                                                 delete_netdev);
 904
 905         unregister_netdev(entry->netdev);
 906
 907         /* The entry pointer is deleted by the netdev destructor. */
 908 }
 909
 910 static void chan_close_cb(struct l2cap_chan *chan)
 911 {
 912         struct lowpan_dev *entry;
 913         struct lowpan_dev *dev = NULL;
 914         struct lowpan_peer *peer;
 915         int err = -ENOENT;
 916         bool last = false, remove = true;
 917
 918         BT_DBG("chan %p conn %p", chan, chan->conn);
 919
 920         if (chan->conn && chan->conn->hcon) {
 921                 if (!is_bt_6lowpan(chan->conn->hcon))
 922                         return;
 923
 924                 /* If conn is set, then the netdev is also there and we should
 925                  * not remove it.
 926                  */
 927                 remove = false;
 928         }
 929
 930         spin_lock(&devices_lock);
 931
 932         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 933                 dev = lowpan_dev(entry->netdev);
 934                 peer = __peer_lookup_chan(dev, chan);
 935                 if (peer) {
 936                         last = peer_del(dev, peer);
 937                         err = 0;
 938
 939                         BT_DBG("dev %p removing %speer %p", dev,
 940                                last ? "last " : "1 ", peer);
 941                         BT_DBG("chan %p orig refcnt %d", chan,
 942                                atomic_read(&chan->kref.refcount));
 943
 944                         l2cap_chan_put(chan);
 945                         break;
 946                 }
 947         }
 948
 949         if (!err && last && dev && !atomic_read(&dev->peer_count)) {
 950                 spin_unlock(&devices_lock);
 951
 952                 cancel_delayed_work_sync(&dev->notify_peers);
 953
 954                 ifdown(dev->netdev);
 955
 956                 if (remove) {
 957                         INIT_WORK(&entry->delete_netdev, delete_netdev);
 958                         schedule_work(&entry->delete_netdev);
 959                 }
 960         } else {
 961                 spin_unlock(&devices_lock);
 962         }
 963
 964         return;
 965 }
 966
 967 static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err)
 968 {
 969         BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn,
 970                state_to_string(state), err);
 971 }
 972
 973 static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan,
 974                                          unsigned long hdr_len,
 975                                          unsigned long len, int nb)
 976 {
 977         /* Note that we must allocate using GFP_ATOMIC here as
 978          * this function is called originally from netdev hard xmit
 979          * function in atomic context.
 980          */
 981         return bt_skb_alloc(hdr_len + len, GFP_ATOMIC);
 982 }
 983
 984 static void chan_suspend_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 = -EAGAIN;
 994 }
 995
 996 static void chan_resume_cb(struct l2cap_chan *chan)
 997 {
 998         struct sk_buff *skb = chan->data;
 999
1000         BT_DBG("chan %p conn %p skb %p", chan, chan->conn, skb);
1001
1002         if (!skb)
1003                 return;
1004
1005         lowpan_cb(skb)->status = 0;
1006 }
1007
1008 static long chan_get_sndtimeo_cb(struct l2cap_chan *chan)
1009 {
1010         return L2CAP_CONN_TIMEOUT;
1011 }
1012
1013 static const struct l2cap_ops bt_6lowpan_chan_ops = {
1014         .name                   = "L2CAP 6LoWPAN channel",
1015         .new_connection         = chan_new_conn_cb,
1016         .recv                   = chan_recv_cb,
1017         .close                  = chan_close_cb,
1018         .state_change           = chan_state_change_cb,
1019         .ready                  = chan_ready_cb,
1020         .resume                 = chan_resume_cb,
1021         .suspend                = chan_suspend_cb,
1022         .get_sndtimeo           = chan_get_sndtimeo_cb,
1023         .alloc_skb              = chan_alloc_skb_cb,
1024
1025         .teardown               = l2cap_chan_no_teardown,
1026         .defer                  = l2cap_chan_no_defer,
1027         .set_shutdown           = l2cap_chan_no_set_shutdown,
1028 };
1029
1030 static inline __u8 bdaddr_type(__u8 type)
1031 {
1032         if (type == ADDR_LE_DEV_PUBLIC)
1033                 return BDADDR_LE_PUBLIC;
1034         else
1035                 return BDADDR_LE_RANDOM;
1036 }
1037
1038 static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type)
1039 {
1040         struct l2cap_chan *chan;
1041         int err;
1042
1043         chan = chan_create();
1044         if (!chan)
1045                 return -EINVAL;
1046
1047         chan->ops = &bt_6lowpan_chan_ops;
1048
1049         err = l2cap_chan_connect(chan, cpu_to_le16(L2CAP_PSM_IPSP), 0,
1050                                  addr, dst_type);
1051
1052         BT_DBG("chan %p err %d", chan, err);
1053         if (err < 0)
1054                 l2cap_chan_put(chan);
1055
1056         return err;
1057 }
1058
1059 static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type)
1060 {
1061         struct lowpan_peer *peer;
1062
1063         BT_DBG("conn %p dst type %d", conn, dst_type);
1064
1065         peer = lookup_peer(conn);
1066         if (!peer)
1067                 return -ENOENT;
1068
1069         BT_DBG("peer %p chan %p", peer, peer->chan);
1070
1071         l2cap_chan_close(peer->chan, ENOENT);
1072
1073         return 0;
1074 }
1075
1076 static struct l2cap_chan *bt_6lowpan_listen(void)
1077 {
1078         bdaddr_t *addr = BDADDR_ANY;
1079         struct l2cap_chan *chan;
1080         int err;
1081
1082         if (!enable_6lowpan)
1083                 return NULL;
1084
1085         chan = chan_create();
1086         if (!chan)
1087                 return NULL;
1088
1089         chan->ops = &bt_6lowpan_chan_ops;
1090         chan->state = BT_LISTEN;
1091         chan->src_type = BDADDR_LE_PUBLIC;
1092
1093         atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
1094
1095         BT_DBG("chan %p src type %d", chan, chan->src_type);
1096
1097         err = l2cap_add_psm(chan, addr, cpu_to_le16(L2CAP_PSM_IPSP));
1098         if (err) {
1099                 l2cap_chan_put(chan);
1100                 BT_ERR("psm cannot be added err %d", err);
1101                 return NULL;
1102         }
1103
1104         return chan;
1105 }
1106
1107 static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type,
1108                           struct l2cap_conn **conn)
1109 {
1110         struct hci_conn *hcon;
1111         struct hci_dev *hdev;
1112         bdaddr_t *src = BDADDR_ANY;
1113         int n;
1114
1115         n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu",
1116                    &addr->b[5], &addr->b[4], &addr->b[3],
1117                    &addr->b[2], &addr->b[1], &addr->b[0],
1118                    addr_type);
1119
1120         if (n < 7)
1121                 return -EINVAL;
1122
1123         hdev = hci_get_route(addr, src);
1124         if (!hdev)
1125                 return -ENOENT;
1126
1127         hci_dev_lock(hdev);
1128         hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type);
1129         hci_dev_unlock(hdev);
1130
1131         if (!hcon)
1132                 return -ENOENT;
1133
1134         *conn = (struct l2cap_conn *)hcon->l2cap_data;
1135
1136         BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type);
1137
1138         return 0;
1139 }
1140
1141 static void disconnect_all_peers(void)
1142 {
1143         struct lowpan_dev *entry;
1144         struct lowpan_peer *peer, *tmp_peer, *new_peer;
1145         struct list_head peers;
1146
1147         INIT_LIST_HEAD(&peers);
1148
1149         /* We make a separate list of peers as the close_cb() will
1150          * modify the device peers list so it is better not to mess
1151          * with the same list at the same time.
1152          */
1153
1154         rcu_read_lock();
1155
1156         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1157                 list_for_each_entry_rcu(peer, &entry->peers, list) {
1158                         new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC);
1159                         if (!new_peer)
1160                                 break;
1161
1162                         new_peer->chan = peer->chan;
1163                         INIT_LIST_HEAD(&new_peer->list);
1164
1165                         list_add(&new_peer->list, &peers);
1166                 }
1167         }
1168
1169         rcu_read_unlock();
1170
1171         spin_lock(&devices_lock);
1172         list_for_each_entry_safe(peer, tmp_peer, &peers, list) {
1173                 l2cap_chan_close(peer->chan, ENOENT);
1174
1175                 list_del_rcu(&peer->list);
1176                 kfree_rcu(peer, rcu);
1177         }
1178         spin_unlock(&devices_lock);
1179 }
1180
1181 struct set_enable {
1182         struct work_struct work;
1183         bool flag;
1184 };
1185
1186 static void do_enable_set(struct work_struct *work)
1187 {
1188         struct set_enable *set_enable = container_of(work,
1189                                                      struct set_enable, work);
1190
1191         if (!set_enable->flag || enable_6lowpan != set_enable->flag)
1192                 /* Disconnect existing connections if 6lowpan is
1193                  * disabled
1194                  */
1195                 disconnect_all_peers();
1196
1197         enable_6lowpan = set_enable->flag;
1198
1199         mutex_lock(&set_lock);
1200         if (listen_chan) {
1201                 l2cap_chan_close(listen_chan, 0);
1202                 l2cap_chan_put(listen_chan);
1203         }
1204
1205         listen_chan = bt_6lowpan_listen();
1206         mutex_unlock(&set_lock);
1207
1208         kfree(set_enable);
1209 }
1210
1211 static int lowpan_enable_set(void *data, u64 val)
1212 {
1213         struct set_enable *set_enable;
1214
1215         set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL);
1216         if (!set_enable)
1217                 return -ENOMEM;
1218
1219         set_enable->flag = !!val;
1220         INIT_WORK(&set_enable->work, do_enable_set);
1221
1222         schedule_work(&set_enable->work);
1223
1224         return 0;
1225 }
1226
1227 static int lowpan_enable_get(void *data, u64 *val)
1228 {
1229         *val = enable_6lowpan;
1230         return 0;
1231 }
1232
1233 DEFINE_SIMPLE_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get,
1234                         lowpan_enable_set, "%llu\n");
1235
1236 static ssize_t lowpan_control_write(struct file *fp,
1237                                     const char __user *user_buffer,
1238                                     size_t count,
1239                                     loff_t *position)
1240 {
1241         char buf[32];
1242         size_t buf_size = min(count, sizeof(buf) - 1);
1243         int ret;
1244         bdaddr_t addr;
1245         u8 addr_type;
1246         struct l2cap_conn *conn = NULL;
1247
1248         if (copy_from_user(buf, user_buffer, buf_size))
1249                 return -EFAULT;
1250
1251         buf[buf_size] = '\0';
1252
1253         if (memcmp(buf, "connect ", 8) == 0) {
1254                 ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn);
1255                 if (ret == -EINVAL)
1256                         return ret;
1257
1258                 mutex_lock(&set_lock);
1259                 if (listen_chan) {
1260                         l2cap_chan_close(listen_chan, 0);
1261                         l2cap_chan_put(listen_chan);
1262                         listen_chan = NULL;
1263                 }
1264                 mutex_unlock(&set_lock);
1265
1266                 if (conn) {
1267                         struct lowpan_peer *peer;
1268
1269                         if (!is_bt_6lowpan(conn->hcon))
1270                                 return -EINVAL;
1271
1272                         peer = lookup_peer(conn);
1273                         if (peer) {
1274                                 BT_DBG("6LoWPAN connection already exists");
1275                                 return -EALREADY;
1276                         }
1277
1278                         BT_DBG("conn %p dst %pMR type %d user %d", conn,
1279                                &conn->hcon->dst, conn->hcon->dst_type,
1280                                addr_type);
1281                 }
1282
1283                 ret = bt_6lowpan_connect(&addr, addr_type);
1284                 if (ret < 0)
1285                         return ret;
1286
1287                 return count;
1288         }
1289
1290         if (memcmp(buf, "disconnect ", 11) == 0) {
1291                 ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn);
1292                 if (ret < 0)
1293                         return ret;
1294
1295                 ret = bt_6lowpan_disconnect(conn, addr_type);
1296                 if (ret < 0)
1297                         return ret;
1298
1299                 return count;
1300         }
1301
1302         return count;
1303 }
1304
1305 static int lowpan_control_show(struct seq_file *f, void *ptr)
1306 {
1307         struct lowpan_dev *entry;
1308         struct lowpan_peer *peer;
1309
1310         spin_lock(&devices_lock);
1311
1312         list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1313                 list_for_each_entry(peer, &entry->peers, list)
1314                         seq_printf(f, "%pMR (type %u)\n",
1315                                    &peer->chan->dst, peer->chan->dst_type);
1316         }
1317
1318         spin_unlock(&devices_lock);
1319
1320         return 0;
1321 }
1322
1323 static int lowpan_control_open(struct inode *inode, struct file *file)
1324 {
1325         return single_open(file, lowpan_control_show, inode->i_private);
1326 }
1327
1328 static const struct file_operations lowpan_control_fops = {
1329         .open           = lowpan_control_open,
1330         .read           = seq_read,
1331         .write          = lowpan_control_write,
1332         .llseek         = seq_lseek,
1333         .release        = single_release,
1334 };
1335
1336 static void disconnect_devices(void)
1337 {
1338         struct lowpan_dev *entry, *tmp, *new_dev;
1339         struct list_head devices;
1340
1341         INIT_LIST_HEAD(&devices);
1342
1343         /* We make a separate list of devices because the unregister_netdev()
1344          * will call device_event() which will also want to modify the same
1345          * devices list.
1346          */
1347
1348         rcu_read_lock();
1349
1350         list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1351                 new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC);
1352                 if (!new_dev)
1353                         break;
1354
1355                 new_dev->netdev = entry->netdev;
1356                 INIT_LIST_HEAD(&new_dev->list);
1357
1358                 list_add_rcu(&new_dev->list, &devices);
1359         }
1360
1361         rcu_read_unlock();
1362
1363         list_for_each_entry_safe(entry, tmp, &devices, list) {
1364                 ifdown(entry->netdev);
1365                 BT_DBG("Unregistering netdev %s %p",
1366                        entry->netdev->name, entry->netdev);
1367                 unregister_netdev(entry->netdev);
1368                 kfree(entry);
1369         }
1370 }
1371
1372 static int device_event(struct notifier_block *unused,
1373                         unsigned long event, void *ptr)
1374 {
1375         struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
1376         struct lowpan_dev *entry;
1377
1378         if (netdev->type != ARPHRD_6LOWPAN)
1379                 return NOTIFY_DONE;
1380
1381         switch (event) {
1382         case NETDEV_UNREGISTER:
1383                 spin_lock(&devices_lock);
1384                 list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1385                         if (entry->netdev == netdev) {
1386                                 BT_DBG("Unregistered netdev %s %p",
1387                                        netdev->name, netdev);
1388                                 list_del(&entry->list);
1389                                 break;
1390                         }
1391                 }
1392                 spin_unlock(&devices_lock);
1393                 break;
1394         }
1395
1396         return NOTIFY_DONE;
1397 }
1398
1399 static struct notifier_block bt_6lowpan_dev_notifier = {
1400         .notifier_call = device_event,
1401 };
1402
1403 static int __init bt_6lowpan_init(void)
1404 {
1405         lowpan_enable_debugfs = debugfs_create_file("6lowpan_enable", 0644,
1406                                                     bt_debugfs, NULL,
1407                                                     &lowpan_enable_fops);
1408         lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644,
1409                                                      bt_debugfs, NULL,
1410                                                      &lowpan_control_fops);
1411
1412         return register_netdevice_notifier(&bt_6lowpan_dev_notifier);
1413 }
1414
1415 static void __exit bt_6lowpan_exit(void)
1416 {
1417         debugfs_remove(lowpan_enable_debugfs);
1418         debugfs_remove(lowpan_control_debugfs);
1419
1420         if (listen_chan) {
1421                 l2cap_chan_close(listen_chan, 0);
1422                 l2cap_chan_put(listen_chan);
1423         }
1424
1425         disconnect_devices();
1426
1427         unregister_netdevice_notifier(&bt_6lowpan_dev_notifier);
1428 }
1429
1430 module_init(bt_6lowpan_init);
1431 module_exit(bt_6lowpan_exit);
1432
1433 MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>");
1434 MODULE_DESCRIPTION("Bluetooth 6LoWPAN");
1435 MODULE_VERSION(VERSION);
1436 MODULE_LICENSE("GPL");