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v5.4
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3   Copyright (c) 2013-2014 Intel Corp.
   4
   5*/
   6
   7#include <linux/if_arp.h>
   8#include <linux/netdevice.h>
   9#include <linux/etherdevice.h>
  10#include <linux/module.h>
  11#include <linux/debugfs.h>
  12
  13#include <net/ipv6.h>
  14#include <net/ip6_route.h>
  15#include <net/addrconf.h>
  16#include <net/pkt_sched.h>
  17
  18#include <net/bluetooth/bluetooth.h>
  19#include <net/bluetooth/hci_core.h>
  20#include <net/bluetooth/l2cap.h>
  21
  22#include <net/6lowpan.h> /* for the compression support */
  23
  24#define VERSION "0.1"
  25
  26static struct dentry *lowpan_enable_debugfs;
  27static struct dentry *lowpan_control_debugfs;
  28
  29#define IFACE_NAME_TEMPLATE "bt%d"
  30
  31struct skb_cb {
  32	struct in6_addr addr;
  33	struct in6_addr gw;
  34	struct l2cap_chan *chan;
  35};
  36#define lowpan_cb(skb) ((struct skb_cb *)((skb)->cb))
  37
  38/* The devices list contains those devices that we are acting
  39 * as a proxy. The BT 6LoWPAN device is a virtual device that
  40 * connects to the Bluetooth LE device. The real connection to
  41 * BT device is done via l2cap layer. There exists one
  42 * virtual device / one BT 6LoWPAN network (=hciX device).
  43 * The list contains struct lowpan_dev elements.
  44 */
  45static LIST_HEAD(bt_6lowpan_devices);
  46static DEFINE_SPINLOCK(devices_lock);
  47
  48static bool enable_6lowpan;
  49
  50/* We are listening incoming connections via this channel
  51 */
  52static struct l2cap_chan *listen_chan;
 
  53
  54struct lowpan_peer {
  55	struct list_head list;
  56	struct rcu_head rcu;
  57	struct l2cap_chan *chan;
  58
  59	/* peer addresses in various formats */
  60	unsigned char lladdr[ETH_ALEN];
  61	struct in6_addr peer_addr;
  62};
  63
  64struct lowpan_btle_dev {
  65	struct list_head list;
  66
  67	struct hci_dev *hdev;
  68	struct net_device *netdev;
  69	struct list_head peers;
  70	atomic_t peer_count; /* number of items in peers list */
  71
  72	struct work_struct delete_netdev;
  73	struct delayed_work notify_peers;
  74};
  75
  76static inline struct lowpan_btle_dev *
  77lowpan_btle_dev(const struct net_device *netdev)
  78{
  79	return (struct lowpan_btle_dev *)lowpan_dev(netdev)->priv;
  80}
  81
  82static inline void peer_add(struct lowpan_btle_dev *dev,
  83			    struct lowpan_peer *peer)
  84{
  85	list_add_rcu(&peer->list, &dev->peers);
  86	atomic_inc(&dev->peer_count);
  87}
  88
  89static inline bool peer_del(struct lowpan_btle_dev *dev,
  90			    struct lowpan_peer *peer)
  91{
  92	list_del_rcu(&peer->list);
  93	kfree_rcu(peer, rcu);
  94
  95	module_put(THIS_MODULE);
  96
  97	if (atomic_dec_and_test(&dev->peer_count)) {
  98		BT_DBG("last peer");
  99		return true;
 100	}
 101
 102	return false;
 103}
 104
 105static inline struct lowpan_peer *peer_lookup_ba(struct lowpan_btle_dev *dev,
 106						 bdaddr_t *ba, __u8 type)
 107{
 108	struct lowpan_peer *peer;
 109
 110	BT_DBG("peers %d addr %pMR type %d", atomic_read(&dev->peer_count),
 111	       ba, type);
 112
 113	rcu_read_lock();
 114
 115	list_for_each_entry_rcu(peer, &dev->peers, list) {
 116		BT_DBG("dst addr %pMR dst type %d",
 117		       &peer->chan->dst, peer->chan->dst_type);
 118
 119		if (bacmp(&peer->chan->dst, ba))
 120			continue;
 121
 122		if (type == peer->chan->dst_type) {
 123			rcu_read_unlock();
 124			return peer;
 125		}
 126	}
 127
 128	rcu_read_unlock();
 129
 130	return NULL;
 131}
 132
 133static inline struct lowpan_peer *
 134__peer_lookup_chan(struct lowpan_btle_dev *dev, struct l2cap_chan *chan)
 135{
 136	struct lowpan_peer *peer;
 137
 138	list_for_each_entry_rcu(peer, &dev->peers, list) {
 139		if (peer->chan == chan)
 140			return peer;
 141	}
 142
 143	return NULL;
 144}
 145
 146static inline struct lowpan_peer *
 147__peer_lookup_conn(struct lowpan_btle_dev *dev, struct l2cap_conn *conn)
 148{
 149	struct lowpan_peer *peer;
 150
 151	list_for_each_entry_rcu(peer, &dev->peers, list) {
 152		if (peer->chan->conn == conn)
 153			return peer;
 154	}
 155
 156	return NULL;
 157}
 158
 159static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_btle_dev *dev,
 160						  struct in6_addr *daddr,
 161						  struct sk_buff *skb)
 162{
 163	struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
 164	int count = atomic_read(&dev->peer_count);
 165	const struct in6_addr *nexthop;
 166	struct lowpan_peer *peer;
 167	struct neighbour *neigh;
 168
 169	BT_DBG("peers %d addr %pI6c rt %p", count, daddr, rt);
 170
 171	if (!rt) {
 172		if (ipv6_addr_any(&lowpan_cb(skb)->gw)) {
 173			/* There is neither route nor gateway,
 174			 * probably the destination is a direct peer.
 175			 */
 176			nexthop = daddr;
 177		} else {
 178			/* There is a known gateway
 179			 */
 180			nexthop = &lowpan_cb(skb)->gw;
 181		}
 182	} else {
 183		nexthop = rt6_nexthop(rt, daddr);
 184
 185		/* We need to remember the address because it is needed
 186		 * by bt_xmit() when sending the packet. In bt_xmit(), the
 187		 * destination routing info is not set.
 188		 */
 189		memcpy(&lowpan_cb(skb)->gw, nexthop, sizeof(struct in6_addr));
 190	}
 191
 192	BT_DBG("gw %pI6c", nexthop);
 193
 194	rcu_read_lock();
 195
 196	list_for_each_entry_rcu(peer, &dev->peers, list) {
 197		BT_DBG("dst addr %pMR dst type %d ip %pI6c",
 198		       &peer->chan->dst, peer->chan->dst_type,
 199		       &peer->peer_addr);
 200
 201		if (!ipv6_addr_cmp(&peer->peer_addr, nexthop)) {
 202			rcu_read_unlock();
 203			return peer;
 204		}
 205	}
 206
 207	/* use the neighbour cache for matching addresses assigned by SLAAC
 208	*/
 209	neigh = __ipv6_neigh_lookup(dev->netdev, nexthop);
 210	if (neigh) {
 211		list_for_each_entry_rcu(peer, &dev->peers, list) {
 212			if (!memcmp(neigh->ha, peer->lladdr, ETH_ALEN)) {
 213				neigh_release(neigh);
 214				rcu_read_unlock();
 215				return peer;
 216			}
 217		}
 218		neigh_release(neigh);
 219	}
 220
 221	rcu_read_unlock();
 222
 223	return NULL;
 224}
 225
 226static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn)
 227{
 228	struct lowpan_btle_dev *entry;
 229	struct lowpan_peer *peer = NULL;
 230
 231	rcu_read_lock();
 232
 233	list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 234		peer = __peer_lookup_conn(entry, conn);
 235		if (peer)
 236			break;
 237	}
 238
 239	rcu_read_unlock();
 240
 241	return peer;
 242}
 243
 244static struct lowpan_btle_dev *lookup_dev(struct l2cap_conn *conn)
 245{
 246	struct lowpan_btle_dev *entry;
 247	struct lowpan_btle_dev *dev = NULL;
 248
 249	rcu_read_lock();
 250
 251	list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 252		if (conn->hcon->hdev == entry->hdev) {
 253			dev = entry;
 254			break;
 255		}
 256	}
 257
 258	rcu_read_unlock();
 259
 260	return dev;
 261}
 262
 263static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev)
 264{
 265	struct sk_buff *skb_cp;
 266
 267	skb_cp = skb_copy(skb, GFP_ATOMIC);
 268	if (!skb_cp)
 269		return NET_RX_DROP;
 270
 271	return netif_rx_ni(skb_cp);
 272}
 273
 274static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev,
 275			   struct lowpan_peer *peer)
 276{
 277	const u8 *saddr;
 278
 279	saddr = peer->lladdr;
 280
 281	return lowpan_header_decompress(skb, netdev, netdev->dev_addr, saddr);
 282}
 283
 284static int recv_pkt(struct sk_buff *skb, struct net_device *dev,
 285		    struct lowpan_peer *peer)
 286{
 287	struct sk_buff *local_skb;
 288	int ret;
 289
 290	if (!netif_running(dev))
 291		goto drop;
 292
 293	if (dev->type != ARPHRD_6LOWPAN || !skb->len)
 294		goto drop;
 295
 296	skb_reset_network_header(skb);
 297
 298	skb = skb_share_check(skb, GFP_ATOMIC);
 299	if (!skb)
 300		goto drop;
 301
 302	/* check that it's our buffer */
 303	if (lowpan_is_ipv6(*skb_network_header(skb))) {
 304		/* Pull off the 1-byte of 6lowpan header. */
 305		skb_pull(skb, 1);
 306
 307		/* Copy the packet so that the IPv6 header is
 308		 * properly aligned.
 309		 */
 310		local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
 311					    skb_tailroom(skb), GFP_ATOMIC);
 312		if (!local_skb)
 313			goto drop;
 314
 315		local_skb->protocol = htons(ETH_P_IPV6);
 316		local_skb->pkt_type = PACKET_HOST;
 317		local_skb->dev = dev;
 318
 319		skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
 320
 321		if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) {
 322			kfree_skb(local_skb);
 323			goto drop;
 324		}
 325
 326		dev->stats.rx_bytes += skb->len;
 327		dev->stats.rx_packets++;
 328
 329		consume_skb(local_skb);
 330		consume_skb(skb);
 331	} else if (lowpan_is_iphc(*skb_network_header(skb))) {
 332		local_skb = skb_clone(skb, GFP_ATOMIC);
 333		if (!local_skb)
 334			goto drop;
 335
 336		local_skb->dev = dev;
 337
 338		ret = iphc_decompress(local_skb, dev, peer);
 339		if (ret < 0) {
 340			BT_DBG("iphc_decompress failed: %d", ret);
 341			kfree_skb(local_skb);
 342			goto drop;
 343		}
 344
 345		local_skb->protocol = htons(ETH_P_IPV6);
 346		local_skb->pkt_type = PACKET_HOST;
 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		BT_DBG("unknown packet type");
 361		goto drop;
 362	}
 363
 364	return NET_RX_SUCCESS;
 365
 366drop:
 367	dev->stats.rx_dropped++;
 368	return NET_RX_DROP;
 369}
 370
 371/* Packet from BT LE device */
 372static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
 373{
 374	struct lowpan_btle_dev *dev;
 375	struct lowpan_peer *peer;
 376	int err;
 377
 378	peer = lookup_peer(chan->conn);
 379	if (!peer)
 380		return -ENOENT;
 381
 382	dev = lookup_dev(chan->conn);
 383	if (!dev || !dev->netdev)
 384		return -ENOENT;
 385
 386	err = recv_pkt(skb, dev->netdev, peer);
 387	if (err) {
 388		BT_DBG("recv pkt %d", err);
 389		err = -EAGAIN;
 390	}
 391
 392	return err;
 393}
 394
 395static int setup_header(struct sk_buff *skb, struct net_device *netdev,
 396			bdaddr_t *peer_addr, u8 *peer_addr_type)
 397{
 398	struct in6_addr ipv6_daddr;
 399	struct ipv6hdr *hdr;
 400	struct lowpan_btle_dev *dev;
 401	struct lowpan_peer *peer;
 402	u8 *daddr;
 403	int err, status = 0;
 404
 405	hdr = ipv6_hdr(skb);
 406
 407	dev = lowpan_btle_dev(netdev);
 408
 409	memcpy(&ipv6_daddr, &hdr->daddr, sizeof(ipv6_daddr));
 410
 411	if (ipv6_addr_is_multicast(&ipv6_daddr)) {
 412		lowpan_cb(skb)->chan = NULL;
 413		daddr = NULL;
 414	} else {
 415		BT_DBG("dest IP %pI6c", &ipv6_daddr);
 416
 417		/* The packet might be sent to 6lowpan interface
 418		 * because of routing (either via default route
 419		 * or user set route) so get peer according to
 420		 * the destination address.
 421		 */
 422		peer = peer_lookup_dst(dev, &ipv6_daddr, skb);
 423		if (!peer) {
 424			BT_DBG("no such peer");
 425			return -ENOENT;
 426		}
 427
 428		daddr = peer->lladdr;
 429		*peer_addr = peer->chan->dst;
 430		*peer_addr_type = peer->chan->dst_type;
 431		lowpan_cb(skb)->chan = peer->chan;
 432
 433		status = 1;
 434	}
 435
 436	lowpan_header_compress(skb, netdev, daddr, dev->netdev->dev_addr);
 437
 438	err = dev_hard_header(skb, netdev, ETH_P_IPV6, NULL, NULL, 0);
 439	if (err < 0)
 440		return err;
 441
 442	return status;
 443}
 444
 445static int header_create(struct sk_buff *skb, struct net_device *netdev,
 446			 unsigned short type, const void *_daddr,
 447			 const void *_saddr, unsigned int len)
 448{
 449	if (type != ETH_P_IPV6)
 450		return -EINVAL;
 451
 452	return 0;
 453}
 454
 455/* Packet to BT LE device */
 456static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb,
 457		    struct net_device *netdev)
 458{
 459	struct msghdr msg;
 460	struct kvec iv;
 461	int err;
 462
 463	/* Remember the skb so that we can send EAGAIN to the caller if
 464	 * we run out of credits.
 465	 */
 466	chan->data = skb;
 467
 468	iv.iov_base = skb->data;
 469	iv.iov_len = skb->len;
 470
 471	memset(&msg, 0, sizeof(msg));
 472	iov_iter_kvec(&msg.msg_iter, WRITE, &iv, 1, skb->len);
 473
 474	err = l2cap_chan_send(chan, &msg, skb->len);
 475	if (err > 0) {
 476		netdev->stats.tx_bytes += err;
 477		netdev->stats.tx_packets++;
 478		return 0;
 479	}
 480
 481	if (err < 0)
 482		netdev->stats.tx_errors++;
 483
 484	return err;
 485}
 486
 487static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev)
 488{
 489	struct sk_buff *local_skb;
 490	struct lowpan_btle_dev *entry;
 491	int err = 0;
 492
 493	rcu_read_lock();
 494
 495	list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 496		struct lowpan_peer *pentry;
 497		struct lowpan_btle_dev *dev;
 498
 499		if (entry->netdev != netdev)
 500			continue;
 501
 502		dev = lowpan_btle_dev(entry->netdev);
 503
 504		list_for_each_entry_rcu(pentry, &dev->peers, list) {
 505			int ret;
 506
 507			local_skb = skb_clone(skb, GFP_ATOMIC);
 508
 509			BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
 510			       netdev->name,
 511			       &pentry->chan->dst, pentry->chan->dst_type,
 512			       &pentry->peer_addr, pentry->chan);
 513			ret = send_pkt(pentry->chan, local_skb, netdev);
 514			if (ret < 0)
 515				err = ret;
 516
 517			kfree_skb(local_skb);
 518		}
 519	}
 520
 521	rcu_read_unlock();
 522
 523	return err;
 524}
 525
 526static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev)
 527{
 528	int err = 0;
 529	bdaddr_t addr;
 530	u8 addr_type;
 531
 532	/* We must take a copy of the skb before we modify/replace the ipv6
 533	 * header as the header could be used elsewhere
 534	 */
 535	skb = skb_unshare(skb, GFP_ATOMIC);
 536	if (!skb)
 537		return NET_XMIT_DROP;
 538
 539	/* Return values from setup_header()
 540	 *  <0 - error, packet is dropped
 541	 *   0 - this is a multicast packet
 542	 *   1 - this is unicast packet
 543	 */
 544	err = setup_header(skb, netdev, &addr, &addr_type);
 545	if (err < 0) {
 546		kfree_skb(skb);
 547		return NET_XMIT_DROP;
 548	}
 549
 550	if (err) {
 551		if (lowpan_cb(skb)->chan) {
 552			BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
 553			       netdev->name, &addr, addr_type,
 554			       &lowpan_cb(skb)->addr, lowpan_cb(skb)->chan);
 555			err = send_pkt(lowpan_cb(skb)->chan, skb, netdev);
 556		} else {
 557			err = -ENOENT;
 558		}
 559	} else {
 560		/* We need to send the packet to every device behind this
 561		 * interface.
 562		 */
 563		err = send_mcast_pkt(skb, netdev);
 564	}
 565
 566	dev_kfree_skb(skb);
 567
 568	if (err)
 569		BT_DBG("ERROR: xmit failed (%d)", err);
 570
 571	return err < 0 ? NET_XMIT_DROP : err;
 572}
 573
 
 
 
 
 
 
 
 574static const struct net_device_ops netdev_ops = {
 
 575	.ndo_start_xmit		= bt_xmit,
 576};
 577
 578static const struct header_ops header_ops = {
 579	.create	= header_create,
 580};
 581
 582static void netdev_setup(struct net_device *dev)
 583{
 584	dev->hard_header_len	= 0;
 585	dev->needed_tailroom	= 0;
 586	dev->flags		= IFF_RUNNING | IFF_MULTICAST;
 587	dev->watchdog_timeo	= 0;
 588	dev->tx_queue_len	= DEFAULT_TX_QUEUE_LEN;
 589
 590	dev->netdev_ops		= &netdev_ops;
 591	dev->header_ops		= &header_ops;
 592	dev->needs_free_netdev	= true;
 593}
 594
 595static struct device_type bt_type = {
 596	.name	= "bluetooth",
 597};
 598
 599static void ifup(struct net_device *netdev)
 600{
 601	int err;
 602
 603	rtnl_lock();
 604	err = dev_open(netdev, NULL);
 605	if (err < 0)
 606		BT_INFO("iface %s cannot be opened (%d)", netdev->name, err);
 607	rtnl_unlock();
 608}
 609
 610static void ifdown(struct net_device *netdev)
 611{
 612	rtnl_lock();
 613	dev_close(netdev);
 614	rtnl_unlock();
 615}
 616
 617static void do_notify_peers(struct work_struct *work)
 618{
 619	struct lowpan_btle_dev *dev = container_of(work, struct lowpan_btle_dev,
 620						   notify_peers.work);
 621
 622	netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */
 623}
 624
 625static bool is_bt_6lowpan(struct hci_conn *hcon)
 626{
 627	if (hcon->type != LE_LINK)
 628		return false;
 629
 630	if (!enable_6lowpan)
 631		return false;
 632
 633	return true;
 634}
 635
 636static struct l2cap_chan *chan_create(void)
 637{
 638	struct l2cap_chan *chan;
 639
 640	chan = l2cap_chan_create();
 641	if (!chan)
 642		return NULL;
 643
 644	l2cap_chan_set_defaults(chan);
 645
 646	chan->chan_type = L2CAP_CHAN_CONN_ORIENTED;
 647	chan->mode = L2CAP_MODE_LE_FLOWCTL;
 648	chan->imtu = 1280;
 649
 650	return chan;
 651}
 652
 653static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan,
 654					struct lowpan_btle_dev *dev,
 655					bool new_netdev)
 656{
 657	struct lowpan_peer *peer;
 658
 659	peer = kzalloc(sizeof(*peer), GFP_ATOMIC);
 660	if (!peer)
 661		return NULL;
 662
 663	peer->chan = chan;
 664	memset(&peer->peer_addr, 0, sizeof(struct in6_addr));
 665
 666	baswap((void *)peer->lladdr, &chan->dst);
 667
 668	lowpan_iphc_uncompress_eui48_lladdr(&peer->peer_addr, peer->lladdr);
 669
 670	spin_lock(&devices_lock);
 671	INIT_LIST_HEAD(&peer->list);
 672	peer_add(dev, peer);
 673	spin_unlock(&devices_lock);
 674
 675	/* Notifying peers about us needs to be done without locks held */
 676	if (new_netdev)
 677		INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers);
 678	schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100));
 679
 680	return peer->chan;
 681}
 682
 683static int setup_netdev(struct l2cap_chan *chan, struct lowpan_btle_dev **dev)
 684{
 685	struct net_device *netdev;
 686	int err = 0;
 687
 688	netdev = alloc_netdev(LOWPAN_PRIV_SIZE(sizeof(struct lowpan_btle_dev)),
 689			      IFACE_NAME_TEMPLATE, NET_NAME_UNKNOWN,
 690			      netdev_setup);
 691	if (!netdev)
 692		return -ENOMEM;
 693
 694	netdev->addr_assign_type = NET_ADDR_PERM;
 695	baswap((void *)netdev->dev_addr, &chan->src);
 696
 697	netdev->netdev_ops = &netdev_ops;
 698	SET_NETDEV_DEV(netdev, &chan->conn->hcon->hdev->dev);
 699	SET_NETDEV_DEVTYPE(netdev, &bt_type);
 700
 701	*dev = lowpan_btle_dev(netdev);
 702	(*dev)->netdev = netdev;
 703	(*dev)->hdev = chan->conn->hcon->hdev;
 704	INIT_LIST_HEAD(&(*dev)->peers);
 705
 706	spin_lock(&devices_lock);
 707	INIT_LIST_HEAD(&(*dev)->list);
 708	list_add_rcu(&(*dev)->list, &bt_6lowpan_devices);
 709	spin_unlock(&devices_lock);
 710
 711	err = lowpan_register_netdev(netdev, LOWPAN_LLTYPE_BTLE);
 712	if (err < 0) {
 713		BT_INFO("register_netdev failed %d", err);
 714		spin_lock(&devices_lock);
 715		list_del_rcu(&(*dev)->list);
 716		spin_unlock(&devices_lock);
 717		free_netdev(netdev);
 718		goto out;
 719	}
 720
 721	BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d",
 722	       netdev->ifindex, &chan->dst, chan->dst_type,
 723	       &chan->src, chan->src_type);
 724	set_bit(__LINK_STATE_PRESENT, &netdev->state);
 725
 726	return 0;
 727
 728out:
 729	return err;
 730}
 731
 732static inline void chan_ready_cb(struct l2cap_chan *chan)
 733{
 734	struct lowpan_btle_dev *dev;
 735	bool new_netdev = false;
 736
 737	dev = lookup_dev(chan->conn);
 738
 739	BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev);
 740
 741	if (!dev) {
 742		if (setup_netdev(chan, &dev) < 0) {
 743			l2cap_chan_del(chan, -ENOENT);
 744			return;
 745		}
 746		new_netdev = true;
 747	}
 748
 749	if (!try_module_get(THIS_MODULE))
 750		return;
 751
 752	add_peer_chan(chan, dev, new_netdev);
 753	ifup(dev->netdev);
 754}
 755
 756static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan)
 757{
 758	struct l2cap_chan *chan;
 759
 760	chan = chan_create();
 761	if (!chan)
 762		return NULL;
 763
 764	chan->ops = pchan->ops;
 765
 766	BT_DBG("chan %p pchan %p", chan, pchan);
 767
 768	return chan;
 769}
 770
 771static void delete_netdev(struct work_struct *work)
 772{
 773	struct lowpan_btle_dev *entry = container_of(work,
 774						     struct lowpan_btle_dev,
 775						     delete_netdev);
 776
 777	lowpan_unregister_netdev(entry->netdev);
 778
 779	/* The entry pointer is deleted by the netdev destructor. */
 780}
 781
 782static void chan_close_cb(struct l2cap_chan *chan)
 783{
 784	struct lowpan_btle_dev *entry;
 785	struct lowpan_btle_dev *dev = NULL;
 786	struct lowpan_peer *peer;
 787	int err = -ENOENT;
 788	bool last = false, remove = true;
 789
 790	BT_DBG("chan %p conn %p", chan, chan->conn);
 791
 792	if (chan->conn && chan->conn->hcon) {
 793		if (!is_bt_6lowpan(chan->conn->hcon))
 794			return;
 795
 796		/* If conn is set, then the netdev is also there and we should
 797		 * not remove it.
 798		 */
 799		remove = false;
 800	}
 801
 802	spin_lock(&devices_lock);
 803
 804	list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 805		dev = lowpan_btle_dev(entry->netdev);
 806		peer = __peer_lookup_chan(dev, chan);
 807		if (peer) {
 808			last = peer_del(dev, peer);
 809			err = 0;
 810
 811			BT_DBG("dev %p removing %speer %p", dev,
 812			       last ? "last " : "1 ", peer);
 813			BT_DBG("chan %p orig refcnt %d", chan,
 814			       kref_read(&chan->kref));
 815
 816			l2cap_chan_put(chan);
 817			break;
 818		}
 819	}
 820
 821	if (!err && last && dev && !atomic_read(&dev->peer_count)) {
 822		spin_unlock(&devices_lock);
 823
 824		cancel_delayed_work_sync(&dev->notify_peers);
 825
 826		ifdown(dev->netdev);
 827
 828		if (remove) {
 829			INIT_WORK(&entry->delete_netdev, delete_netdev);
 830			schedule_work(&entry->delete_netdev);
 831		}
 832	} else {
 833		spin_unlock(&devices_lock);
 834	}
 835
 836	return;
 837}
 838
 839static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err)
 840{
 841	BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn,
 842	       state_to_string(state), err);
 843}
 844
 845static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan,
 846					 unsigned long hdr_len,
 847					 unsigned long len, int nb)
 848{
 849	/* Note that we must allocate using GFP_ATOMIC here as
 850	 * this function is called originally from netdev hard xmit
 851	 * function in atomic context.
 852	 */
 853	return bt_skb_alloc(hdr_len + len, GFP_ATOMIC);
 854}
 855
 856static void chan_suspend_cb(struct l2cap_chan *chan)
 857{
 858	struct lowpan_btle_dev *dev;
 859
 860	BT_DBG("chan %p suspend", chan);
 861
 862	dev = lookup_dev(chan->conn);
 863	if (!dev || !dev->netdev)
 864		return;
 865
 866	netif_stop_queue(dev->netdev);
 867}
 868
 869static void chan_resume_cb(struct l2cap_chan *chan)
 870{
 871	struct lowpan_btle_dev *dev;
 872
 873	BT_DBG("chan %p resume", chan);
 874
 875	dev = lookup_dev(chan->conn);
 876	if (!dev || !dev->netdev)
 877		return;
 878
 879	netif_wake_queue(dev->netdev);
 880}
 881
 882static long chan_get_sndtimeo_cb(struct l2cap_chan *chan)
 883{
 884	return L2CAP_CONN_TIMEOUT;
 885}
 886
 887static const struct l2cap_ops bt_6lowpan_chan_ops = {
 888	.name			= "L2CAP 6LoWPAN channel",
 889	.new_connection		= chan_new_conn_cb,
 890	.recv			= chan_recv_cb,
 891	.close			= chan_close_cb,
 892	.state_change		= chan_state_change_cb,
 893	.ready			= chan_ready_cb,
 894	.resume			= chan_resume_cb,
 895	.suspend		= chan_suspend_cb,
 896	.get_sndtimeo		= chan_get_sndtimeo_cb,
 897	.alloc_skb		= chan_alloc_skb_cb,
 898
 899	.teardown		= l2cap_chan_no_teardown,
 900	.defer			= l2cap_chan_no_defer,
 901	.set_shutdown		= l2cap_chan_no_set_shutdown,
 902};
 903
 904static inline __u8 bdaddr_type(__u8 type)
 905{
 906	if (type == ADDR_LE_DEV_PUBLIC)
 907		return BDADDR_LE_PUBLIC;
 908	else
 909		return BDADDR_LE_RANDOM;
 910}
 911
 912static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type)
 913{
 914	struct l2cap_chan *chan;
 915	int err;
 916
 917	chan = chan_create();
 918	if (!chan)
 919		return -EINVAL;
 920
 921	chan->ops = &bt_6lowpan_chan_ops;
 922
 923	err = l2cap_chan_connect(chan, cpu_to_le16(L2CAP_PSM_IPSP), 0,
 924				 addr, dst_type);
 925
 926	BT_DBG("chan %p err %d", chan, err);
 927	if (err < 0)
 928		l2cap_chan_put(chan);
 929
 930	return err;
 931}
 932
 933static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type)
 934{
 935	struct lowpan_peer *peer;
 936
 937	BT_DBG("conn %p dst type %d", conn, dst_type);
 938
 939	peer = lookup_peer(conn);
 940	if (!peer)
 941		return -ENOENT;
 942
 943	BT_DBG("peer %p chan %p", peer, peer->chan);
 944
 945	l2cap_chan_close(peer->chan, ENOENT);
 946
 947	return 0;
 948}
 949
 950static struct l2cap_chan *bt_6lowpan_listen(void)
 951{
 952	bdaddr_t *addr = BDADDR_ANY;
 953	struct l2cap_chan *chan;
 954	int err;
 955
 956	if (!enable_6lowpan)
 957		return NULL;
 958
 959	chan = chan_create();
 960	if (!chan)
 961		return NULL;
 962
 963	chan->ops = &bt_6lowpan_chan_ops;
 964	chan->state = BT_LISTEN;
 965	chan->src_type = BDADDR_LE_PUBLIC;
 966
 967	atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
 968
 969	BT_DBG("chan %p src type %d", chan, chan->src_type);
 970
 971	err = l2cap_add_psm(chan, addr, cpu_to_le16(L2CAP_PSM_IPSP));
 972	if (err) {
 973		l2cap_chan_put(chan);
 974		BT_ERR("psm cannot be added err %d", err);
 975		return NULL;
 976	}
 977
 978	return chan;
 979}
 980
 981static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type,
 982			  struct l2cap_conn **conn)
 983{
 984	struct hci_conn *hcon;
 985	struct hci_dev *hdev;
 986	int n;
 987
 988	n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu",
 989		   &addr->b[5], &addr->b[4], &addr->b[3],
 990		   &addr->b[2], &addr->b[1], &addr->b[0],
 991		   addr_type);
 992
 993	if (n < 7)
 994		return -EINVAL;
 995
 996	/* The LE_PUBLIC address type is ignored because of BDADDR_ANY */
 997	hdev = hci_get_route(addr, BDADDR_ANY, BDADDR_LE_PUBLIC);
 998	if (!hdev)
 999		return -ENOENT;
1000
1001	hci_dev_lock(hdev);
1002	hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type);
1003	hci_dev_unlock(hdev);
1004
1005	if (!hcon)
1006		return -ENOENT;
1007
1008	*conn = (struct l2cap_conn *)hcon->l2cap_data;
1009
1010	BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type);
1011
1012	return 0;
1013}
1014
1015static void disconnect_all_peers(void)
1016{
1017	struct lowpan_btle_dev *entry;
1018	struct lowpan_peer *peer, *tmp_peer, *new_peer;
1019	struct list_head peers;
1020
1021	INIT_LIST_HEAD(&peers);
1022
1023	/* We make a separate list of peers as the close_cb() will
1024	 * modify the device peers list so it is better not to mess
1025	 * with the same list at the same time.
1026	 */
1027
1028	rcu_read_lock();
1029
1030	list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1031		list_for_each_entry_rcu(peer, &entry->peers, list) {
1032			new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC);
1033			if (!new_peer)
1034				break;
1035
1036			new_peer->chan = peer->chan;
1037			INIT_LIST_HEAD(&new_peer->list);
1038
1039			list_add(&new_peer->list, &peers);
1040		}
1041	}
1042
1043	rcu_read_unlock();
1044
1045	spin_lock(&devices_lock);
1046	list_for_each_entry_safe(peer, tmp_peer, &peers, list) {
1047		l2cap_chan_close(peer->chan, ENOENT);
1048
1049		list_del_rcu(&peer->list);
1050		kfree_rcu(peer, rcu);
1051	}
1052	spin_unlock(&devices_lock);
1053}
1054
1055struct set_enable {
1056	struct work_struct work;
1057	bool flag;
1058};
1059
1060static void do_enable_set(struct work_struct *work)
1061{
1062	struct set_enable *set_enable = container_of(work,
1063						     struct set_enable, work);
1064
1065	if (!set_enable->flag || enable_6lowpan != set_enable->flag)
1066		/* Disconnect existing connections if 6lowpan is
1067		 * disabled
1068		 */
1069		disconnect_all_peers();
1070
1071	enable_6lowpan = set_enable->flag;
1072
 
1073	if (listen_chan) {
1074		l2cap_chan_close(listen_chan, 0);
1075		l2cap_chan_put(listen_chan);
1076	}
1077
1078	listen_chan = bt_6lowpan_listen();
 
1079
1080	kfree(set_enable);
1081}
1082
1083static int lowpan_enable_set(void *data, u64 val)
1084{
1085	struct set_enable *set_enable;
1086
1087	set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL);
1088	if (!set_enable)
1089		return -ENOMEM;
1090
1091	set_enable->flag = !!val;
1092	INIT_WORK(&set_enable->work, do_enable_set);
1093
1094	schedule_work(&set_enable->work);
1095
1096	return 0;
1097}
1098
1099static int lowpan_enable_get(void *data, u64 *val)
1100{
1101	*val = enable_6lowpan;
1102	return 0;
1103}
1104
1105DEFINE_DEBUGFS_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get,
1106			 lowpan_enable_set, "%llu\n");
1107
1108static ssize_t lowpan_control_write(struct file *fp,
1109				    const char __user *user_buffer,
1110				    size_t count,
1111				    loff_t *position)
1112{
1113	char buf[32];
1114	size_t buf_size = min(count, sizeof(buf) - 1);
1115	int ret;
1116	bdaddr_t addr;
1117	u8 addr_type;
1118	struct l2cap_conn *conn = NULL;
1119
1120	if (copy_from_user(buf, user_buffer, buf_size))
1121		return -EFAULT;
1122
1123	buf[buf_size] = '\0';
1124
1125	if (memcmp(buf, "connect ", 8) == 0) {
1126		ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn);
1127		if (ret == -EINVAL)
1128			return ret;
1129
 
1130		if (listen_chan) {
1131			l2cap_chan_close(listen_chan, 0);
1132			l2cap_chan_put(listen_chan);
1133			listen_chan = NULL;
1134		}
 
1135
1136		if (conn) {
1137			struct lowpan_peer *peer;
1138
1139			if (!is_bt_6lowpan(conn->hcon))
1140				return -EINVAL;
1141
1142			peer = lookup_peer(conn);
1143			if (peer) {
1144				BT_DBG("6LoWPAN connection already exists");
1145				return -EALREADY;
1146			}
1147
1148			BT_DBG("conn %p dst %pMR type %d user %d", conn,
1149			       &conn->hcon->dst, conn->hcon->dst_type,
1150			       addr_type);
1151		}
1152
1153		ret = bt_6lowpan_connect(&addr, addr_type);
1154		if (ret < 0)
1155			return ret;
1156
1157		return count;
1158	}
1159
1160	if (memcmp(buf, "disconnect ", 11) == 0) {
1161		ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn);
1162		if (ret < 0)
1163			return ret;
1164
1165		ret = bt_6lowpan_disconnect(conn, addr_type);
1166		if (ret < 0)
1167			return ret;
1168
1169		return count;
1170	}
1171
1172	return count;
1173}
1174
1175static int lowpan_control_show(struct seq_file *f, void *ptr)
1176{
1177	struct lowpan_btle_dev *entry;
1178	struct lowpan_peer *peer;
1179
1180	spin_lock(&devices_lock);
1181
1182	list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1183		list_for_each_entry(peer, &entry->peers, list)
1184			seq_printf(f, "%pMR (type %u)\n",
1185				   &peer->chan->dst, peer->chan->dst_type);
1186	}
1187
1188	spin_unlock(&devices_lock);
1189
1190	return 0;
1191}
1192
1193static int lowpan_control_open(struct inode *inode, struct file *file)
1194{
1195	return single_open(file, lowpan_control_show, inode->i_private);
1196}
1197
1198static const struct file_operations lowpan_control_fops = {
1199	.open		= lowpan_control_open,
1200	.read		= seq_read,
1201	.write		= lowpan_control_write,
1202	.llseek		= seq_lseek,
1203	.release	= single_release,
1204};
1205
1206static void disconnect_devices(void)
1207{
1208	struct lowpan_btle_dev *entry, *tmp, *new_dev;
1209	struct list_head devices;
1210
1211	INIT_LIST_HEAD(&devices);
1212
1213	/* We make a separate list of devices because the unregister_netdev()
1214	 * will call device_event() which will also want to modify the same
1215	 * devices list.
1216	 */
1217
1218	rcu_read_lock();
1219
1220	list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1221		new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC);
1222		if (!new_dev)
1223			break;
1224
1225		new_dev->netdev = entry->netdev;
1226		INIT_LIST_HEAD(&new_dev->list);
1227
1228		list_add_rcu(&new_dev->list, &devices);
1229	}
1230
1231	rcu_read_unlock();
1232
1233	list_for_each_entry_safe(entry, tmp, &devices, list) {
1234		ifdown(entry->netdev);
1235		BT_DBG("Unregistering netdev %s %p",
1236		       entry->netdev->name, entry->netdev);
1237		lowpan_unregister_netdev(entry->netdev);
1238		kfree(entry);
1239	}
1240}
1241
1242static int device_event(struct notifier_block *unused,
1243			unsigned long event, void *ptr)
1244{
1245	struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
1246	struct lowpan_btle_dev *entry;
1247
1248	if (netdev->type != ARPHRD_6LOWPAN)
1249		return NOTIFY_DONE;
1250
1251	switch (event) {
1252	case NETDEV_UNREGISTER:
1253		spin_lock(&devices_lock);
1254		list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1255			if (entry->netdev == netdev) {
1256				BT_DBG("Unregistered netdev %s %p",
1257				       netdev->name, netdev);
1258				list_del(&entry->list);
1259				break;
1260			}
1261		}
1262		spin_unlock(&devices_lock);
1263		break;
1264	}
1265
1266	return NOTIFY_DONE;
1267}
1268
1269static struct notifier_block bt_6lowpan_dev_notifier = {
1270	.notifier_call = device_event,
1271};
1272
1273static int __init bt_6lowpan_init(void)
1274{
1275	lowpan_enable_debugfs = debugfs_create_file_unsafe("6lowpan_enable",
1276							   0644, bt_debugfs,
1277							   NULL,
1278							   &lowpan_enable_fops);
1279	lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644,
1280						     bt_debugfs, NULL,
1281						     &lowpan_control_fops);
1282
1283	return register_netdevice_notifier(&bt_6lowpan_dev_notifier);
1284}
1285
1286static void __exit bt_6lowpan_exit(void)
1287{
1288	debugfs_remove(lowpan_enable_debugfs);
1289	debugfs_remove(lowpan_control_debugfs);
1290
1291	if (listen_chan) {
1292		l2cap_chan_close(listen_chan, 0);
1293		l2cap_chan_put(listen_chan);
1294	}
1295
1296	disconnect_devices();
1297
1298	unregister_netdevice_notifier(&bt_6lowpan_dev_notifier);
1299}
1300
1301module_init(bt_6lowpan_init);
1302module_exit(bt_6lowpan_exit);
1303
1304MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>");
1305MODULE_DESCRIPTION("Bluetooth 6LoWPAN");
1306MODULE_VERSION(VERSION);
1307MODULE_LICENSE("GPL");
v5.9
   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3   Copyright (c) 2013-2014 Intel Corp.
   4
   5*/
   6
   7#include <linux/if_arp.h>
   8#include <linux/netdevice.h>
   9#include <linux/etherdevice.h>
  10#include <linux/module.h>
  11#include <linux/debugfs.h>
  12
  13#include <net/ipv6.h>
  14#include <net/ip6_route.h>
  15#include <net/addrconf.h>
  16#include <net/pkt_sched.h>
  17
  18#include <net/bluetooth/bluetooth.h>
  19#include <net/bluetooth/hci_core.h>
  20#include <net/bluetooth/l2cap.h>
  21
  22#include <net/6lowpan.h> /* for the compression support */
  23
  24#define VERSION "0.1"
  25
  26static struct dentry *lowpan_enable_debugfs;
  27static struct dentry *lowpan_control_debugfs;
  28
  29#define IFACE_NAME_TEMPLATE "bt%d"
  30
  31struct skb_cb {
  32	struct in6_addr addr;
  33	struct in6_addr gw;
  34	struct l2cap_chan *chan;
  35};
  36#define lowpan_cb(skb) ((struct skb_cb *)((skb)->cb))
  37
  38/* The devices list contains those devices that we are acting
  39 * as a proxy. The BT 6LoWPAN device is a virtual device that
  40 * connects to the Bluetooth LE device. The real connection to
  41 * BT device is done via l2cap layer. There exists one
  42 * virtual device / one BT 6LoWPAN network (=hciX device).
  43 * The list contains struct lowpan_dev elements.
  44 */
  45static LIST_HEAD(bt_6lowpan_devices);
  46static DEFINE_SPINLOCK(devices_lock);
  47
  48static bool enable_6lowpan;
  49
  50/* We are listening incoming connections via this channel
  51 */
  52static struct l2cap_chan *listen_chan;
  53static DEFINE_MUTEX(set_lock);
  54
  55struct lowpan_peer {
  56	struct list_head list;
  57	struct rcu_head rcu;
  58	struct l2cap_chan *chan;
  59
  60	/* peer addresses in various formats */
  61	unsigned char lladdr[ETH_ALEN];
  62	struct in6_addr peer_addr;
  63};
  64
  65struct lowpan_btle_dev {
  66	struct list_head list;
  67
  68	struct hci_dev *hdev;
  69	struct net_device *netdev;
  70	struct list_head peers;
  71	atomic_t peer_count; /* number of items in peers list */
  72
  73	struct work_struct delete_netdev;
  74	struct delayed_work notify_peers;
  75};
  76
  77static inline struct lowpan_btle_dev *
  78lowpan_btle_dev(const struct net_device *netdev)
  79{
  80	return (struct lowpan_btle_dev *)lowpan_dev(netdev)->priv;
  81}
  82
  83static inline void peer_add(struct lowpan_btle_dev *dev,
  84			    struct lowpan_peer *peer)
  85{
  86	list_add_rcu(&peer->list, &dev->peers);
  87	atomic_inc(&dev->peer_count);
  88}
  89
  90static inline bool peer_del(struct lowpan_btle_dev *dev,
  91			    struct lowpan_peer *peer)
  92{
  93	list_del_rcu(&peer->list);
  94	kfree_rcu(peer, rcu);
  95
  96	module_put(THIS_MODULE);
  97
  98	if (atomic_dec_and_test(&dev->peer_count)) {
  99		BT_DBG("last peer");
 100		return true;
 101	}
 102
 103	return false;
 104}
 105
 106static inline struct lowpan_peer *peer_lookup_ba(struct lowpan_btle_dev *dev,
 107						 bdaddr_t *ba, __u8 type)
 108{
 109	struct lowpan_peer *peer;
 110
 111	BT_DBG("peers %d addr %pMR type %d", atomic_read(&dev->peer_count),
 112	       ba, type);
 113
 114	rcu_read_lock();
 115
 116	list_for_each_entry_rcu(peer, &dev->peers, list) {
 117		BT_DBG("dst addr %pMR dst type %d",
 118		       &peer->chan->dst, peer->chan->dst_type);
 119
 120		if (bacmp(&peer->chan->dst, ba))
 121			continue;
 122
 123		if (type == peer->chan->dst_type) {
 124			rcu_read_unlock();
 125			return peer;
 126		}
 127	}
 128
 129	rcu_read_unlock();
 130
 131	return NULL;
 132}
 133
 134static inline struct lowpan_peer *
 135__peer_lookup_chan(struct lowpan_btle_dev *dev, struct l2cap_chan *chan)
 136{
 137	struct lowpan_peer *peer;
 138
 139	list_for_each_entry_rcu(peer, &dev->peers, list) {
 140		if (peer->chan == chan)
 141			return peer;
 142	}
 143
 144	return NULL;
 145}
 146
 147static inline struct lowpan_peer *
 148__peer_lookup_conn(struct lowpan_btle_dev *dev, struct l2cap_conn *conn)
 149{
 150	struct lowpan_peer *peer;
 151
 152	list_for_each_entry_rcu(peer, &dev->peers, list) {
 153		if (peer->chan->conn == conn)
 154			return peer;
 155	}
 156
 157	return NULL;
 158}
 159
 160static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_btle_dev *dev,
 161						  struct in6_addr *daddr,
 162						  struct sk_buff *skb)
 163{
 164	struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
 165	int count = atomic_read(&dev->peer_count);
 166	const struct in6_addr *nexthop;
 167	struct lowpan_peer *peer;
 168	struct neighbour *neigh;
 169
 170	BT_DBG("peers %d addr %pI6c rt %p", count, daddr, rt);
 171
 172	if (!rt) {
 173		if (ipv6_addr_any(&lowpan_cb(skb)->gw)) {
 174			/* There is neither route nor gateway,
 175			 * probably the destination is a direct peer.
 176			 */
 177			nexthop = daddr;
 178		} else {
 179			/* There is a known gateway
 180			 */
 181			nexthop = &lowpan_cb(skb)->gw;
 182		}
 183	} else {
 184		nexthop = rt6_nexthop(rt, daddr);
 185
 186		/* We need to remember the address because it is needed
 187		 * by bt_xmit() when sending the packet. In bt_xmit(), the
 188		 * destination routing info is not set.
 189		 */
 190		memcpy(&lowpan_cb(skb)->gw, nexthop, sizeof(struct in6_addr));
 191	}
 192
 193	BT_DBG("gw %pI6c", nexthop);
 194
 195	rcu_read_lock();
 196
 197	list_for_each_entry_rcu(peer, &dev->peers, list) {
 198		BT_DBG("dst addr %pMR dst type %d ip %pI6c",
 199		       &peer->chan->dst, peer->chan->dst_type,
 200		       &peer->peer_addr);
 201
 202		if (!ipv6_addr_cmp(&peer->peer_addr, nexthop)) {
 203			rcu_read_unlock();
 204			return peer;
 205		}
 206	}
 207
 208	/* use the neighbour cache for matching addresses assigned by SLAAC
 209	*/
 210	neigh = __ipv6_neigh_lookup(dev->netdev, nexthop);
 211	if (neigh) {
 212		list_for_each_entry_rcu(peer, &dev->peers, list) {
 213			if (!memcmp(neigh->ha, peer->lladdr, ETH_ALEN)) {
 214				neigh_release(neigh);
 215				rcu_read_unlock();
 216				return peer;
 217			}
 218		}
 219		neigh_release(neigh);
 220	}
 221
 222	rcu_read_unlock();
 223
 224	return NULL;
 225}
 226
 227static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn)
 228{
 229	struct lowpan_btle_dev *entry;
 230	struct lowpan_peer *peer = NULL;
 231
 232	rcu_read_lock();
 233
 234	list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 235		peer = __peer_lookup_conn(entry, conn);
 236		if (peer)
 237			break;
 238	}
 239
 240	rcu_read_unlock();
 241
 242	return peer;
 243}
 244
 245static struct lowpan_btle_dev *lookup_dev(struct l2cap_conn *conn)
 246{
 247	struct lowpan_btle_dev *entry;
 248	struct lowpan_btle_dev *dev = NULL;
 249
 250	rcu_read_lock();
 251
 252	list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 253		if (conn->hcon->hdev == entry->hdev) {
 254			dev = entry;
 255			break;
 256		}
 257	}
 258
 259	rcu_read_unlock();
 260
 261	return dev;
 262}
 263
 264static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev)
 265{
 266	struct sk_buff *skb_cp;
 267
 268	skb_cp = skb_copy(skb, GFP_ATOMIC);
 269	if (!skb_cp)
 270		return NET_RX_DROP;
 271
 272	return netif_rx_ni(skb_cp);
 273}
 274
 275static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev,
 276			   struct lowpan_peer *peer)
 277{
 278	const u8 *saddr;
 279
 280	saddr = peer->lladdr;
 281
 282	return lowpan_header_decompress(skb, netdev, netdev->dev_addr, saddr);
 283}
 284
 285static int recv_pkt(struct sk_buff *skb, struct net_device *dev,
 286		    struct lowpan_peer *peer)
 287{
 288	struct sk_buff *local_skb;
 289	int ret;
 290
 291	if (!netif_running(dev))
 292		goto drop;
 293
 294	if (dev->type != ARPHRD_6LOWPAN || !skb->len)
 295		goto drop;
 296
 297	skb_reset_network_header(skb);
 298
 299	skb = skb_share_check(skb, GFP_ATOMIC);
 300	if (!skb)
 301		goto drop;
 302
 303	/* check that it's our buffer */
 304	if (lowpan_is_ipv6(*skb_network_header(skb))) {
 305		/* Pull off the 1-byte of 6lowpan header. */
 306		skb_pull(skb, 1);
 307
 308		/* Copy the packet so that the IPv6 header is
 309		 * properly aligned.
 310		 */
 311		local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
 312					    skb_tailroom(skb), GFP_ATOMIC);
 313		if (!local_skb)
 314			goto drop;
 315
 316		local_skb->protocol = htons(ETH_P_IPV6);
 317		local_skb->pkt_type = PACKET_HOST;
 318		local_skb->dev = dev;
 319
 320		skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
 321
 322		if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) {
 323			kfree_skb(local_skb);
 324			goto drop;
 325		}
 326
 327		dev->stats.rx_bytes += skb->len;
 328		dev->stats.rx_packets++;
 329
 330		consume_skb(local_skb);
 331		consume_skb(skb);
 332	} else if (lowpan_is_iphc(*skb_network_header(skb))) {
 333		local_skb = skb_clone(skb, GFP_ATOMIC);
 334		if (!local_skb)
 335			goto drop;
 336
 337		local_skb->dev = dev;
 338
 339		ret = iphc_decompress(local_skb, dev, peer);
 340		if (ret < 0) {
 341			BT_DBG("iphc_decompress failed: %d", ret);
 342			kfree_skb(local_skb);
 343			goto drop;
 344		}
 345
 346		local_skb->protocol = htons(ETH_P_IPV6);
 347		local_skb->pkt_type = PACKET_HOST;
 348
 349		if (give_skb_to_upper(local_skb, dev)
 350				!= NET_RX_SUCCESS) {
 351			kfree_skb(local_skb);
 352			goto drop;
 353		}
 354
 355		dev->stats.rx_bytes += skb->len;
 356		dev->stats.rx_packets++;
 357
 358		consume_skb(local_skb);
 359		consume_skb(skb);
 360	} else {
 361		BT_DBG("unknown packet type");
 362		goto drop;
 363	}
 364
 365	return NET_RX_SUCCESS;
 366
 367drop:
 368	dev->stats.rx_dropped++;
 369	return NET_RX_DROP;
 370}
 371
 372/* Packet from BT LE device */
 373static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
 374{
 375	struct lowpan_btle_dev *dev;
 376	struct lowpan_peer *peer;
 377	int err;
 378
 379	peer = lookup_peer(chan->conn);
 380	if (!peer)
 381		return -ENOENT;
 382
 383	dev = lookup_dev(chan->conn);
 384	if (!dev || !dev->netdev)
 385		return -ENOENT;
 386
 387	err = recv_pkt(skb, dev->netdev, peer);
 388	if (err) {
 389		BT_DBG("recv pkt %d", err);
 390		err = -EAGAIN;
 391	}
 392
 393	return err;
 394}
 395
 396static int setup_header(struct sk_buff *skb, struct net_device *netdev,
 397			bdaddr_t *peer_addr, u8 *peer_addr_type)
 398{
 399	struct in6_addr ipv6_daddr;
 400	struct ipv6hdr *hdr;
 401	struct lowpan_btle_dev *dev;
 402	struct lowpan_peer *peer;
 403	u8 *daddr;
 404	int err, status = 0;
 405
 406	hdr = ipv6_hdr(skb);
 407
 408	dev = lowpan_btle_dev(netdev);
 409
 410	memcpy(&ipv6_daddr, &hdr->daddr, sizeof(ipv6_daddr));
 411
 412	if (ipv6_addr_is_multicast(&ipv6_daddr)) {
 413		lowpan_cb(skb)->chan = NULL;
 414		daddr = NULL;
 415	} else {
 416		BT_DBG("dest IP %pI6c", &ipv6_daddr);
 417
 418		/* The packet might be sent to 6lowpan interface
 419		 * because of routing (either via default route
 420		 * or user set route) so get peer according to
 421		 * the destination address.
 422		 */
 423		peer = peer_lookup_dst(dev, &ipv6_daddr, skb);
 424		if (!peer) {
 425			BT_DBG("no such peer");
 426			return -ENOENT;
 427		}
 428
 429		daddr = peer->lladdr;
 430		*peer_addr = peer->chan->dst;
 431		*peer_addr_type = peer->chan->dst_type;
 432		lowpan_cb(skb)->chan = peer->chan;
 433
 434		status = 1;
 435	}
 436
 437	lowpan_header_compress(skb, netdev, daddr, dev->netdev->dev_addr);
 438
 439	err = dev_hard_header(skb, netdev, ETH_P_IPV6, NULL, NULL, 0);
 440	if (err < 0)
 441		return err;
 442
 443	return status;
 444}
 445
 446static int header_create(struct sk_buff *skb, struct net_device *netdev,
 447			 unsigned short type, const void *_daddr,
 448			 const void *_saddr, unsigned int len)
 449{
 450	if (type != ETH_P_IPV6)
 451		return -EINVAL;
 452
 453	return 0;
 454}
 455
 456/* Packet to BT LE device */
 457static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb,
 458		    struct net_device *netdev)
 459{
 460	struct msghdr msg;
 461	struct kvec iv;
 462	int err;
 463
 464	/* Remember the skb so that we can send EAGAIN to the caller if
 465	 * we run out of credits.
 466	 */
 467	chan->data = skb;
 468
 469	iv.iov_base = skb->data;
 470	iv.iov_len = skb->len;
 471
 472	memset(&msg, 0, sizeof(msg));
 473	iov_iter_kvec(&msg.msg_iter, WRITE, &iv, 1, skb->len);
 474
 475	err = l2cap_chan_send(chan, &msg, skb->len);
 476	if (err > 0) {
 477		netdev->stats.tx_bytes += err;
 478		netdev->stats.tx_packets++;
 479		return 0;
 480	}
 481
 482	if (err < 0)
 483		netdev->stats.tx_errors++;
 484
 485	return err;
 486}
 487
 488static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev)
 489{
 490	struct sk_buff *local_skb;
 491	struct lowpan_btle_dev *entry;
 492	int err = 0;
 493
 494	rcu_read_lock();
 495
 496	list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 497		struct lowpan_peer *pentry;
 498		struct lowpan_btle_dev *dev;
 499
 500		if (entry->netdev != netdev)
 501			continue;
 502
 503		dev = lowpan_btle_dev(entry->netdev);
 504
 505		list_for_each_entry_rcu(pentry, &dev->peers, list) {
 506			int ret;
 507
 508			local_skb = skb_clone(skb, GFP_ATOMIC);
 509
 510			BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
 511			       netdev->name,
 512			       &pentry->chan->dst, pentry->chan->dst_type,
 513			       &pentry->peer_addr, pentry->chan);
 514			ret = send_pkt(pentry->chan, local_skb, netdev);
 515			if (ret < 0)
 516				err = ret;
 517
 518			kfree_skb(local_skb);
 519		}
 520	}
 521
 522	rcu_read_unlock();
 523
 524	return err;
 525}
 526
 527static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev)
 528{
 529	int err = 0;
 530	bdaddr_t addr;
 531	u8 addr_type;
 532
 533	/* We must take a copy of the skb before we modify/replace the ipv6
 534	 * header as the header could be used elsewhere
 535	 */
 536	skb = skb_unshare(skb, GFP_ATOMIC);
 537	if (!skb)
 538		return NET_XMIT_DROP;
 539
 540	/* Return values from setup_header()
 541	 *  <0 - error, packet is dropped
 542	 *   0 - this is a multicast packet
 543	 *   1 - this is unicast packet
 544	 */
 545	err = setup_header(skb, netdev, &addr, &addr_type);
 546	if (err < 0) {
 547		kfree_skb(skb);
 548		return NET_XMIT_DROP;
 549	}
 550
 551	if (err) {
 552		if (lowpan_cb(skb)->chan) {
 553			BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
 554			       netdev->name, &addr, addr_type,
 555			       &lowpan_cb(skb)->addr, lowpan_cb(skb)->chan);
 556			err = send_pkt(lowpan_cb(skb)->chan, skb, netdev);
 557		} else {
 558			err = -ENOENT;
 559		}
 560	} else {
 561		/* We need to send the packet to every device behind this
 562		 * interface.
 563		 */
 564		err = send_mcast_pkt(skb, netdev);
 565	}
 566
 567	dev_kfree_skb(skb);
 568
 569	if (err)
 570		BT_DBG("ERROR: xmit failed (%d)", err);
 571
 572	return err < 0 ? NET_XMIT_DROP : err;
 573}
 574
 575static int bt_dev_init(struct net_device *dev)
 576{
 577	netdev_lockdep_set_classes(dev);
 578
 579	return 0;
 580}
 581
 582static const struct net_device_ops netdev_ops = {
 583	.ndo_init		= bt_dev_init,
 584	.ndo_start_xmit		= bt_xmit,
 585};
 586
 587static const struct header_ops header_ops = {
 588	.create	= header_create,
 589};
 590
 591static void netdev_setup(struct net_device *dev)
 592{
 593	dev->hard_header_len	= 0;
 594	dev->needed_tailroom	= 0;
 595	dev->flags		= IFF_RUNNING | IFF_MULTICAST;
 596	dev->watchdog_timeo	= 0;
 597	dev->tx_queue_len	= DEFAULT_TX_QUEUE_LEN;
 598
 599	dev->netdev_ops		= &netdev_ops;
 600	dev->header_ops		= &header_ops;
 601	dev->needs_free_netdev	= true;
 602}
 603
 604static struct device_type bt_type = {
 605	.name	= "bluetooth",
 606};
 607
 608static void ifup(struct net_device *netdev)
 609{
 610	int err;
 611
 612	rtnl_lock();
 613	err = dev_open(netdev, NULL);
 614	if (err < 0)
 615		BT_INFO("iface %s cannot be opened (%d)", netdev->name, err);
 616	rtnl_unlock();
 617}
 618
 619static void ifdown(struct net_device *netdev)
 620{
 621	rtnl_lock();
 622	dev_close(netdev);
 623	rtnl_unlock();
 624}
 625
 626static void do_notify_peers(struct work_struct *work)
 627{
 628	struct lowpan_btle_dev *dev = container_of(work, struct lowpan_btle_dev,
 629						   notify_peers.work);
 630
 631	netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */
 632}
 633
 634static bool is_bt_6lowpan(struct hci_conn *hcon)
 635{
 636	if (hcon->type != LE_LINK)
 637		return false;
 638
 639	if (!enable_6lowpan)
 640		return false;
 641
 642	return true;
 643}
 644
 645static struct l2cap_chan *chan_create(void)
 646{
 647	struct l2cap_chan *chan;
 648
 649	chan = l2cap_chan_create();
 650	if (!chan)
 651		return NULL;
 652
 653	l2cap_chan_set_defaults(chan);
 654
 655	chan->chan_type = L2CAP_CHAN_CONN_ORIENTED;
 656	chan->mode = L2CAP_MODE_LE_FLOWCTL;
 657	chan->imtu = 1280;
 658
 659	return chan;
 660}
 661
 662static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan,
 663					struct lowpan_btle_dev *dev,
 664					bool new_netdev)
 665{
 666	struct lowpan_peer *peer;
 667
 668	peer = kzalloc(sizeof(*peer), GFP_ATOMIC);
 669	if (!peer)
 670		return NULL;
 671
 672	peer->chan = chan;
 673	memset(&peer->peer_addr, 0, sizeof(struct in6_addr));
 674
 675	baswap((void *)peer->lladdr, &chan->dst);
 676
 677	lowpan_iphc_uncompress_eui48_lladdr(&peer->peer_addr, peer->lladdr);
 678
 679	spin_lock(&devices_lock);
 680	INIT_LIST_HEAD(&peer->list);
 681	peer_add(dev, peer);
 682	spin_unlock(&devices_lock);
 683
 684	/* Notifying peers about us needs to be done without locks held */
 685	if (new_netdev)
 686		INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers);
 687	schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100));
 688
 689	return peer->chan;
 690}
 691
 692static int setup_netdev(struct l2cap_chan *chan, struct lowpan_btle_dev **dev)
 693{
 694	struct net_device *netdev;
 695	int err = 0;
 696
 697	netdev = alloc_netdev(LOWPAN_PRIV_SIZE(sizeof(struct lowpan_btle_dev)),
 698			      IFACE_NAME_TEMPLATE, NET_NAME_UNKNOWN,
 699			      netdev_setup);
 700	if (!netdev)
 701		return -ENOMEM;
 702
 703	netdev->addr_assign_type = NET_ADDR_PERM;
 704	baswap((void *)netdev->dev_addr, &chan->src);
 705
 706	netdev->netdev_ops = &netdev_ops;
 707	SET_NETDEV_DEV(netdev, &chan->conn->hcon->hdev->dev);
 708	SET_NETDEV_DEVTYPE(netdev, &bt_type);
 709
 710	*dev = lowpan_btle_dev(netdev);
 711	(*dev)->netdev = netdev;
 712	(*dev)->hdev = chan->conn->hcon->hdev;
 713	INIT_LIST_HEAD(&(*dev)->peers);
 714
 715	spin_lock(&devices_lock);
 716	INIT_LIST_HEAD(&(*dev)->list);
 717	list_add_rcu(&(*dev)->list, &bt_6lowpan_devices);
 718	spin_unlock(&devices_lock);
 719
 720	err = lowpan_register_netdev(netdev, LOWPAN_LLTYPE_BTLE);
 721	if (err < 0) {
 722		BT_INFO("register_netdev failed %d", err);
 723		spin_lock(&devices_lock);
 724		list_del_rcu(&(*dev)->list);
 725		spin_unlock(&devices_lock);
 726		free_netdev(netdev);
 727		goto out;
 728	}
 729
 730	BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d",
 731	       netdev->ifindex, &chan->dst, chan->dst_type,
 732	       &chan->src, chan->src_type);
 733	set_bit(__LINK_STATE_PRESENT, &netdev->state);
 734
 735	return 0;
 736
 737out:
 738	return err;
 739}
 740
 741static inline void chan_ready_cb(struct l2cap_chan *chan)
 742{
 743	struct lowpan_btle_dev *dev;
 744	bool new_netdev = false;
 745
 746	dev = lookup_dev(chan->conn);
 747
 748	BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev);
 749
 750	if (!dev) {
 751		if (setup_netdev(chan, &dev) < 0) {
 752			l2cap_chan_del(chan, -ENOENT);
 753			return;
 754		}
 755		new_netdev = true;
 756	}
 757
 758	if (!try_module_get(THIS_MODULE))
 759		return;
 760
 761	add_peer_chan(chan, dev, new_netdev);
 762	ifup(dev->netdev);
 763}
 764
 765static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan)
 766{
 767	struct l2cap_chan *chan;
 768
 769	chan = chan_create();
 770	if (!chan)
 771		return NULL;
 772
 773	chan->ops = pchan->ops;
 774
 775	BT_DBG("chan %p pchan %p", chan, pchan);
 776
 777	return chan;
 778}
 779
 780static void delete_netdev(struct work_struct *work)
 781{
 782	struct lowpan_btle_dev *entry = container_of(work,
 783						     struct lowpan_btle_dev,
 784						     delete_netdev);
 785
 786	lowpan_unregister_netdev(entry->netdev);
 787
 788	/* The entry pointer is deleted by the netdev destructor. */
 789}
 790
 791static void chan_close_cb(struct l2cap_chan *chan)
 792{
 793	struct lowpan_btle_dev *entry;
 794	struct lowpan_btle_dev *dev = NULL;
 795	struct lowpan_peer *peer;
 796	int err = -ENOENT;
 797	bool last = false, remove = true;
 798
 799	BT_DBG("chan %p conn %p", chan, chan->conn);
 800
 801	if (chan->conn && chan->conn->hcon) {
 802		if (!is_bt_6lowpan(chan->conn->hcon))
 803			return;
 804
 805		/* If conn is set, then the netdev is also there and we should
 806		 * not remove it.
 807		 */
 808		remove = false;
 809	}
 810
 811	spin_lock(&devices_lock);
 812
 813	list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 814		dev = lowpan_btle_dev(entry->netdev);
 815		peer = __peer_lookup_chan(dev, chan);
 816		if (peer) {
 817			last = peer_del(dev, peer);
 818			err = 0;
 819
 820			BT_DBG("dev %p removing %speer %p", dev,
 821			       last ? "last " : "1 ", peer);
 822			BT_DBG("chan %p orig refcnt %d", chan,
 823			       kref_read(&chan->kref));
 824
 825			l2cap_chan_put(chan);
 826			break;
 827		}
 828	}
 829
 830	if (!err && last && dev && !atomic_read(&dev->peer_count)) {
 831		spin_unlock(&devices_lock);
 832
 833		cancel_delayed_work_sync(&dev->notify_peers);
 834
 835		ifdown(dev->netdev);
 836
 837		if (remove) {
 838			INIT_WORK(&entry->delete_netdev, delete_netdev);
 839			schedule_work(&entry->delete_netdev);
 840		}
 841	} else {
 842		spin_unlock(&devices_lock);
 843	}
 844
 845	return;
 846}
 847
 848static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err)
 849{
 850	BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn,
 851	       state_to_string(state), err);
 852}
 853
 854static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan,
 855					 unsigned long hdr_len,
 856					 unsigned long len, int nb)
 857{
 858	/* Note that we must allocate using GFP_ATOMIC here as
 859	 * this function is called originally from netdev hard xmit
 860	 * function in atomic context.
 861	 */
 862	return bt_skb_alloc(hdr_len + len, GFP_ATOMIC);
 863}
 864
 865static void chan_suspend_cb(struct l2cap_chan *chan)
 866{
 867	struct lowpan_btle_dev *dev;
 868
 869	BT_DBG("chan %p suspend", chan);
 870
 871	dev = lookup_dev(chan->conn);
 872	if (!dev || !dev->netdev)
 873		return;
 874
 875	netif_stop_queue(dev->netdev);
 876}
 877
 878static void chan_resume_cb(struct l2cap_chan *chan)
 879{
 880	struct lowpan_btle_dev *dev;
 881
 882	BT_DBG("chan %p resume", chan);
 883
 884	dev = lookup_dev(chan->conn);
 885	if (!dev || !dev->netdev)
 886		return;
 887
 888	netif_wake_queue(dev->netdev);
 889}
 890
 891static long chan_get_sndtimeo_cb(struct l2cap_chan *chan)
 892{
 893	return L2CAP_CONN_TIMEOUT;
 894}
 895
 896static const struct l2cap_ops bt_6lowpan_chan_ops = {
 897	.name			= "L2CAP 6LoWPAN channel",
 898	.new_connection		= chan_new_conn_cb,
 899	.recv			= chan_recv_cb,
 900	.close			= chan_close_cb,
 901	.state_change		= chan_state_change_cb,
 902	.ready			= chan_ready_cb,
 903	.resume			= chan_resume_cb,
 904	.suspend		= chan_suspend_cb,
 905	.get_sndtimeo		= chan_get_sndtimeo_cb,
 906	.alloc_skb		= chan_alloc_skb_cb,
 907
 908	.teardown		= l2cap_chan_no_teardown,
 909	.defer			= l2cap_chan_no_defer,
 910	.set_shutdown		= l2cap_chan_no_set_shutdown,
 911};
 912
 913static inline __u8 bdaddr_type(__u8 type)
 914{
 915	if (type == ADDR_LE_DEV_PUBLIC)
 916		return BDADDR_LE_PUBLIC;
 917	else
 918		return BDADDR_LE_RANDOM;
 919}
 920
 921static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type)
 922{
 923	struct l2cap_chan *chan;
 924	int err;
 925
 926	chan = chan_create();
 927	if (!chan)
 928		return -EINVAL;
 929
 930	chan->ops = &bt_6lowpan_chan_ops;
 931
 932	err = l2cap_chan_connect(chan, cpu_to_le16(L2CAP_PSM_IPSP), 0,
 933				 addr, dst_type);
 934
 935	BT_DBG("chan %p err %d", chan, err);
 936	if (err < 0)
 937		l2cap_chan_put(chan);
 938
 939	return err;
 940}
 941
 942static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type)
 943{
 944	struct lowpan_peer *peer;
 945
 946	BT_DBG("conn %p dst type %d", conn, dst_type);
 947
 948	peer = lookup_peer(conn);
 949	if (!peer)
 950		return -ENOENT;
 951
 952	BT_DBG("peer %p chan %p", peer, peer->chan);
 953
 954	l2cap_chan_close(peer->chan, ENOENT);
 955
 956	return 0;
 957}
 958
 959static struct l2cap_chan *bt_6lowpan_listen(void)
 960{
 961	bdaddr_t *addr = BDADDR_ANY;
 962	struct l2cap_chan *chan;
 963	int err;
 964
 965	if (!enable_6lowpan)
 966		return NULL;
 967
 968	chan = chan_create();
 969	if (!chan)
 970		return NULL;
 971
 972	chan->ops = &bt_6lowpan_chan_ops;
 973	chan->state = BT_LISTEN;
 974	chan->src_type = BDADDR_LE_PUBLIC;
 975
 976	atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
 977
 978	BT_DBG("chan %p src type %d", chan, chan->src_type);
 979
 980	err = l2cap_add_psm(chan, addr, cpu_to_le16(L2CAP_PSM_IPSP));
 981	if (err) {
 982		l2cap_chan_put(chan);
 983		BT_ERR("psm cannot be added err %d", err);
 984		return NULL;
 985	}
 986
 987	return chan;
 988}
 989
 990static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type,
 991			  struct l2cap_conn **conn)
 992{
 993	struct hci_conn *hcon;
 994	struct hci_dev *hdev;
 995	int n;
 996
 997	n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu",
 998		   &addr->b[5], &addr->b[4], &addr->b[3],
 999		   &addr->b[2], &addr->b[1], &addr->b[0],
1000		   addr_type);
1001
1002	if (n < 7)
1003		return -EINVAL;
1004
1005	/* The LE_PUBLIC address type is ignored because of BDADDR_ANY */
1006	hdev = hci_get_route(addr, BDADDR_ANY, BDADDR_LE_PUBLIC);
1007	if (!hdev)
1008		return -ENOENT;
1009
1010	hci_dev_lock(hdev);
1011	hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type);
1012	hci_dev_unlock(hdev);
1013
1014	if (!hcon)
1015		return -ENOENT;
1016
1017	*conn = (struct l2cap_conn *)hcon->l2cap_data;
1018
1019	BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type);
1020
1021	return 0;
1022}
1023
1024static void disconnect_all_peers(void)
1025{
1026	struct lowpan_btle_dev *entry;
1027	struct lowpan_peer *peer, *tmp_peer, *new_peer;
1028	struct list_head peers;
1029
1030	INIT_LIST_HEAD(&peers);
1031
1032	/* We make a separate list of peers as the close_cb() will
1033	 * modify the device peers list so it is better not to mess
1034	 * with the same list at the same time.
1035	 */
1036
1037	rcu_read_lock();
1038
1039	list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1040		list_for_each_entry_rcu(peer, &entry->peers, list) {
1041			new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC);
1042			if (!new_peer)
1043				break;
1044
1045			new_peer->chan = peer->chan;
1046			INIT_LIST_HEAD(&new_peer->list);
1047
1048			list_add(&new_peer->list, &peers);
1049		}
1050	}
1051
1052	rcu_read_unlock();
1053
1054	spin_lock(&devices_lock);
1055	list_for_each_entry_safe(peer, tmp_peer, &peers, list) {
1056		l2cap_chan_close(peer->chan, ENOENT);
1057
1058		list_del_rcu(&peer->list);
1059		kfree_rcu(peer, rcu);
1060	}
1061	spin_unlock(&devices_lock);
1062}
1063
1064struct set_enable {
1065	struct work_struct work;
1066	bool flag;
1067};
1068
1069static void do_enable_set(struct work_struct *work)
1070{
1071	struct set_enable *set_enable = container_of(work,
1072						     struct set_enable, work);
1073
1074	if (!set_enable->flag || enable_6lowpan != set_enable->flag)
1075		/* Disconnect existing connections if 6lowpan is
1076		 * disabled
1077		 */
1078		disconnect_all_peers();
1079
1080	enable_6lowpan = set_enable->flag;
1081
1082	mutex_lock(&set_lock);
1083	if (listen_chan) {
1084		l2cap_chan_close(listen_chan, 0);
1085		l2cap_chan_put(listen_chan);
1086	}
1087
1088	listen_chan = bt_6lowpan_listen();
1089	mutex_unlock(&set_lock);
1090
1091	kfree(set_enable);
1092}
1093
1094static int lowpan_enable_set(void *data, u64 val)
1095{
1096	struct set_enable *set_enable;
1097
1098	set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL);
1099	if (!set_enable)
1100		return -ENOMEM;
1101
1102	set_enable->flag = !!val;
1103	INIT_WORK(&set_enable->work, do_enable_set);
1104
1105	schedule_work(&set_enable->work);
1106
1107	return 0;
1108}
1109
1110static int lowpan_enable_get(void *data, u64 *val)
1111{
1112	*val = enable_6lowpan;
1113	return 0;
1114}
1115
1116DEFINE_DEBUGFS_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get,
1117			 lowpan_enable_set, "%llu\n");
1118
1119static ssize_t lowpan_control_write(struct file *fp,
1120				    const char __user *user_buffer,
1121				    size_t count,
1122				    loff_t *position)
1123{
1124	char buf[32];
1125	size_t buf_size = min(count, sizeof(buf) - 1);
1126	int ret;
1127	bdaddr_t addr;
1128	u8 addr_type;
1129	struct l2cap_conn *conn = NULL;
1130
1131	if (copy_from_user(buf, user_buffer, buf_size))
1132		return -EFAULT;
1133
1134	buf[buf_size] = '\0';
1135
1136	if (memcmp(buf, "connect ", 8) == 0) {
1137		ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn);
1138		if (ret == -EINVAL)
1139			return ret;
1140
1141		mutex_lock(&set_lock);
1142		if (listen_chan) {
1143			l2cap_chan_close(listen_chan, 0);
1144			l2cap_chan_put(listen_chan);
1145			listen_chan = NULL;
1146		}
1147		mutex_unlock(&set_lock);
1148
1149		if (conn) {
1150			struct lowpan_peer *peer;
1151
1152			if (!is_bt_6lowpan(conn->hcon))
1153				return -EINVAL;
1154
1155			peer = lookup_peer(conn);
1156			if (peer) {
1157				BT_DBG("6LoWPAN connection already exists");
1158				return -EALREADY;
1159			}
1160
1161			BT_DBG("conn %p dst %pMR type %d user %d", conn,
1162			       &conn->hcon->dst, conn->hcon->dst_type,
1163			       addr_type);
1164		}
1165
1166		ret = bt_6lowpan_connect(&addr, addr_type);
1167		if (ret < 0)
1168			return ret;
1169
1170		return count;
1171	}
1172
1173	if (memcmp(buf, "disconnect ", 11) == 0) {
1174		ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn);
1175		if (ret < 0)
1176			return ret;
1177
1178		ret = bt_6lowpan_disconnect(conn, addr_type);
1179		if (ret < 0)
1180			return ret;
1181
1182		return count;
1183	}
1184
1185	return count;
1186}
1187
1188static int lowpan_control_show(struct seq_file *f, void *ptr)
1189{
1190	struct lowpan_btle_dev *entry;
1191	struct lowpan_peer *peer;
1192
1193	spin_lock(&devices_lock);
1194
1195	list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1196		list_for_each_entry(peer, &entry->peers, list)
1197			seq_printf(f, "%pMR (type %u)\n",
1198				   &peer->chan->dst, peer->chan->dst_type);
1199	}
1200
1201	spin_unlock(&devices_lock);
1202
1203	return 0;
1204}
1205
1206static int lowpan_control_open(struct inode *inode, struct file *file)
1207{
1208	return single_open(file, lowpan_control_show, inode->i_private);
1209}
1210
1211static const struct file_operations lowpan_control_fops = {
1212	.open		= lowpan_control_open,
1213	.read		= seq_read,
1214	.write		= lowpan_control_write,
1215	.llseek		= seq_lseek,
1216	.release	= single_release,
1217};
1218
1219static void disconnect_devices(void)
1220{
1221	struct lowpan_btle_dev *entry, *tmp, *new_dev;
1222	struct list_head devices;
1223
1224	INIT_LIST_HEAD(&devices);
1225
1226	/* We make a separate list of devices because the unregister_netdev()
1227	 * will call device_event() which will also want to modify the same
1228	 * devices list.
1229	 */
1230
1231	rcu_read_lock();
1232
1233	list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1234		new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC);
1235		if (!new_dev)
1236			break;
1237
1238		new_dev->netdev = entry->netdev;
1239		INIT_LIST_HEAD(&new_dev->list);
1240
1241		list_add_rcu(&new_dev->list, &devices);
1242	}
1243
1244	rcu_read_unlock();
1245
1246	list_for_each_entry_safe(entry, tmp, &devices, list) {
1247		ifdown(entry->netdev);
1248		BT_DBG("Unregistering netdev %s %p",
1249		       entry->netdev->name, entry->netdev);
1250		lowpan_unregister_netdev(entry->netdev);
1251		kfree(entry);
1252	}
1253}
1254
1255static int device_event(struct notifier_block *unused,
1256			unsigned long event, void *ptr)
1257{
1258	struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
1259	struct lowpan_btle_dev *entry;
1260
1261	if (netdev->type != ARPHRD_6LOWPAN)
1262		return NOTIFY_DONE;
1263
1264	switch (event) {
1265	case NETDEV_UNREGISTER:
1266		spin_lock(&devices_lock);
1267		list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1268			if (entry->netdev == netdev) {
1269				BT_DBG("Unregistered netdev %s %p",
1270				       netdev->name, netdev);
1271				list_del(&entry->list);
1272				break;
1273			}
1274		}
1275		spin_unlock(&devices_lock);
1276		break;
1277	}
1278
1279	return NOTIFY_DONE;
1280}
1281
1282static struct notifier_block bt_6lowpan_dev_notifier = {
1283	.notifier_call = device_event,
1284};
1285
1286static int __init bt_6lowpan_init(void)
1287{
1288	lowpan_enable_debugfs = debugfs_create_file_unsafe("6lowpan_enable",
1289							   0644, bt_debugfs,
1290							   NULL,
1291							   &lowpan_enable_fops);
1292	lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644,
1293						     bt_debugfs, NULL,
1294						     &lowpan_control_fops);
1295
1296	return register_netdevice_notifier(&bt_6lowpan_dev_notifier);
1297}
1298
1299static void __exit bt_6lowpan_exit(void)
1300{
1301	debugfs_remove(lowpan_enable_debugfs);
1302	debugfs_remove(lowpan_control_debugfs);
1303
1304	if (listen_chan) {
1305		l2cap_chan_close(listen_chan, 0);
1306		l2cap_chan_put(listen_chan);
1307	}
1308
1309	disconnect_devices();
1310
1311	unregister_netdevice_notifier(&bt_6lowpan_dev_notifier);
1312}
1313
1314module_init(bt_6lowpan_init);
1315module_exit(bt_6lowpan_exit);
1316
1317MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>");
1318MODULE_DESCRIPTION("Bluetooth 6LoWPAN");
1319MODULE_VERSION(VERSION);
1320MODULE_LICENSE("GPL");