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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");
v4.17
 
   1/*
   2   Copyright (c) 2013-2014 Intel Corp.
   3
   4   This program is free software; you can redistribute it and/or modify
   5   it under the terms of the GNU General Public License version 2 and
   6   only version 2 as published by the Free Software Foundation.
   7
   8   This program is distributed in the hope that it will be useful,
   9   but WITHOUT ANY WARRANTY; without even the implied warranty of
  10   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11   GNU General Public License for more details.
  12*/
  13
  14#include <linux/if_arp.h>
  15#include <linux/netdevice.h>
  16#include <linux/etherdevice.h>
  17#include <linux/module.h>
  18#include <linux/debugfs.h>
  19
  20#include <net/ipv6.h>
  21#include <net/ip6_route.h>
  22#include <net/addrconf.h>
  23#include <net/pkt_sched.h>
  24
  25#include <net/bluetooth/bluetooth.h>
  26#include <net/bluetooth/hci_core.h>
  27#include <net/bluetooth/l2cap.h>
  28
  29#include <net/6lowpan.h> /* for the compression support */
  30
  31#define VERSION "0.1"
  32
  33static struct dentry *lowpan_enable_debugfs;
  34static struct dentry *lowpan_control_debugfs;
  35
  36#define IFACE_NAME_TEMPLATE "bt%d"
  37
  38struct skb_cb {
  39	struct in6_addr addr;
  40	struct in6_addr gw;
  41	struct l2cap_chan *chan;
  42};
  43#define lowpan_cb(skb) ((struct skb_cb *)((skb)->cb))
  44
  45/* The devices list contains those devices that we are acting
  46 * as a proxy. The BT 6LoWPAN device is a virtual device that
  47 * connects to the Bluetooth LE device. The real connection to
  48 * BT device is done via l2cap layer. There exists one
  49 * virtual device / one BT 6LoWPAN network (=hciX device).
  50 * The list contains struct lowpan_dev elements.
  51 */
  52static LIST_HEAD(bt_6lowpan_devices);
  53static DEFINE_SPINLOCK(devices_lock);
  54
  55static bool enable_6lowpan;
  56
  57/* We are listening incoming connections via this channel
  58 */
  59static struct l2cap_chan *listen_chan;
  60
  61struct lowpan_peer {
  62	struct list_head list;
  63	struct rcu_head rcu;
  64	struct l2cap_chan *chan;
  65
  66	/* peer addresses in various formats */
  67	unsigned char lladdr[ETH_ALEN];
  68	struct in6_addr peer_addr;
  69};
  70
  71struct lowpan_btle_dev {
  72	struct list_head list;
  73
  74	struct hci_dev *hdev;
  75	struct net_device *netdev;
  76	struct list_head peers;
  77	atomic_t peer_count; /* number of items in peers list */
  78
  79	struct work_struct delete_netdev;
  80	struct delayed_work notify_peers;
  81};
  82
  83static inline struct lowpan_btle_dev *
  84lowpan_btle_dev(const struct net_device *netdev)
  85{
  86	return (struct lowpan_btle_dev *)lowpan_dev(netdev)->priv;
  87}
  88
  89static inline void peer_add(struct lowpan_btle_dev *dev,
  90			    struct lowpan_peer *peer)
  91{
  92	list_add_rcu(&peer->list, &dev->peers);
  93	atomic_inc(&dev->peer_count);
  94}
  95
  96static inline bool peer_del(struct lowpan_btle_dev *dev,
  97			    struct lowpan_peer *peer)
  98{
  99	list_del_rcu(&peer->list);
 100	kfree_rcu(peer, rcu);
 101
 102	module_put(THIS_MODULE);
 103
 104	if (atomic_dec_and_test(&dev->peer_count)) {
 105		BT_DBG("last peer");
 106		return true;
 107	}
 108
 109	return false;
 110}
 111
 112static inline struct lowpan_peer *peer_lookup_ba(struct lowpan_btle_dev *dev,
 113						 bdaddr_t *ba, __u8 type)
 114{
 115	struct lowpan_peer *peer;
 116
 117	BT_DBG("peers %d addr %pMR type %d", atomic_read(&dev->peer_count),
 118	       ba, type);
 119
 120	rcu_read_lock();
 121
 122	list_for_each_entry_rcu(peer, &dev->peers, list) {
 123		BT_DBG("dst addr %pMR dst type %d",
 124		       &peer->chan->dst, peer->chan->dst_type);
 125
 126		if (bacmp(&peer->chan->dst, ba))
 127			continue;
 128
 129		if (type == peer->chan->dst_type) {
 130			rcu_read_unlock();
 131			return peer;
 132		}
 133	}
 134
 135	rcu_read_unlock();
 136
 137	return NULL;
 138}
 139
 140static inline struct lowpan_peer *
 141__peer_lookup_chan(struct lowpan_btle_dev *dev, struct l2cap_chan *chan)
 142{
 143	struct lowpan_peer *peer;
 144
 145	list_for_each_entry_rcu(peer, &dev->peers, list) {
 146		if (peer->chan == chan)
 147			return peer;
 148	}
 149
 150	return NULL;
 151}
 152
 153static inline struct lowpan_peer *
 154__peer_lookup_conn(struct lowpan_btle_dev *dev, struct l2cap_conn *conn)
 155{
 156	struct lowpan_peer *peer;
 157
 158	list_for_each_entry_rcu(peer, &dev->peers, list) {
 159		if (peer->chan->conn == conn)
 160			return peer;
 161	}
 162
 163	return NULL;
 164}
 165
 166static inline struct lowpan_peer *peer_lookup_dst(struct lowpan_btle_dev *dev,
 167						  struct in6_addr *daddr,
 168						  struct sk_buff *skb)
 169{
 170	struct lowpan_peer *peer;
 171	struct in6_addr *nexthop;
 172	struct rt6_info *rt = (struct rt6_info *)skb_dst(skb);
 173	int count = atomic_read(&dev->peer_count);
 
 
 
 174
 175	BT_DBG("peers %d addr %pI6c rt %p", count, daddr, rt);
 176
 177	/* If we have multiple 6lowpan peers, then check where we should
 178	 * send the packet. If only one peer exists, then we can send the
 179	 * packet right away.
 180	 */
 181	if (count == 1) {
 182		rcu_read_lock();
 183		peer = list_first_or_null_rcu(&dev->peers, struct lowpan_peer,
 184					      list);
 185		rcu_read_unlock();
 186		return peer;
 187	}
 188
 189	if (!rt) {
 190		nexthop = &lowpan_cb(skb)->gw;
 191
 192		if (ipv6_addr_any(nexthop))
 193			return NULL;
 
 
 
 
 
 
 194	} else {
 195		nexthop = rt6_nexthop(rt, daddr);
 196
 197		/* We need to remember the address because it is needed
 198		 * by bt_xmit() when sending the packet. In bt_xmit(), the
 199		 * destination routing info is not set.
 200		 */
 201		memcpy(&lowpan_cb(skb)->gw, nexthop, sizeof(struct in6_addr));
 202	}
 203
 204	BT_DBG("gw %pI6c", nexthop);
 205
 206	rcu_read_lock();
 207
 208	list_for_each_entry_rcu(peer, &dev->peers, list) {
 209		BT_DBG("dst addr %pMR dst type %d ip %pI6c",
 210		       &peer->chan->dst, peer->chan->dst_type,
 211		       &peer->peer_addr);
 212
 213		if (!ipv6_addr_cmp(&peer->peer_addr, nexthop)) {
 214			rcu_read_unlock();
 215			return peer;
 216		}
 217	}
 218
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 219	rcu_read_unlock();
 220
 221	return NULL;
 222}
 223
 224static struct lowpan_peer *lookup_peer(struct l2cap_conn *conn)
 225{
 226	struct lowpan_btle_dev *entry;
 227	struct lowpan_peer *peer = NULL;
 228
 229	rcu_read_lock();
 230
 231	list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 232		peer = __peer_lookup_conn(entry, conn);
 233		if (peer)
 234			break;
 235	}
 236
 237	rcu_read_unlock();
 238
 239	return peer;
 240}
 241
 242static struct lowpan_btle_dev *lookup_dev(struct l2cap_conn *conn)
 243{
 244	struct lowpan_btle_dev *entry;
 245	struct lowpan_btle_dev *dev = NULL;
 246
 247	rcu_read_lock();
 248
 249	list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 250		if (conn->hcon->hdev == entry->hdev) {
 251			dev = entry;
 252			break;
 253		}
 254	}
 255
 256	rcu_read_unlock();
 257
 258	return dev;
 259}
 260
 261static int give_skb_to_upper(struct sk_buff *skb, struct net_device *dev)
 262{
 263	struct sk_buff *skb_cp;
 264
 265	skb_cp = skb_copy(skb, GFP_ATOMIC);
 266	if (!skb_cp)
 267		return NET_RX_DROP;
 268
 269	return netif_rx_ni(skb_cp);
 270}
 271
 272static int iphc_decompress(struct sk_buff *skb, struct net_device *netdev,
 273			   struct lowpan_peer *peer)
 274{
 275	const u8 *saddr;
 276
 277	saddr = peer->lladdr;
 278
 279	return lowpan_header_decompress(skb, netdev, netdev->dev_addr, saddr);
 280}
 281
 282static int recv_pkt(struct sk_buff *skb, struct net_device *dev,
 283		    struct lowpan_peer *peer)
 284{
 285	struct sk_buff *local_skb;
 286	int ret;
 287
 288	if (!netif_running(dev))
 289		goto drop;
 290
 291	if (dev->type != ARPHRD_6LOWPAN || !skb->len)
 292		goto drop;
 293
 294	skb_reset_network_header(skb);
 295
 296	skb = skb_share_check(skb, GFP_ATOMIC);
 297	if (!skb)
 298		goto drop;
 299
 300	/* check that it's our buffer */
 301	if (lowpan_is_ipv6(*skb_network_header(skb))) {
 302		/* Pull off the 1-byte of 6lowpan header. */
 303		skb_pull(skb, 1);
 304
 305		/* Copy the packet so that the IPv6 header is
 306		 * properly aligned.
 307		 */
 308		local_skb = skb_copy_expand(skb, NET_SKB_PAD - 1,
 309					    skb_tailroom(skb), GFP_ATOMIC);
 310		if (!local_skb)
 311			goto drop;
 312
 313		local_skb->protocol = htons(ETH_P_IPV6);
 314		local_skb->pkt_type = PACKET_HOST;
 315		local_skb->dev = dev;
 316
 317		skb_set_transport_header(local_skb, sizeof(struct ipv6hdr));
 318
 319		if (give_skb_to_upper(local_skb, dev) != NET_RX_SUCCESS) {
 320			kfree_skb(local_skb);
 321			goto drop;
 322		}
 323
 324		dev->stats.rx_bytes += skb->len;
 325		dev->stats.rx_packets++;
 326
 327		consume_skb(local_skb);
 328		consume_skb(skb);
 329	} else if (lowpan_is_iphc(*skb_network_header(skb))) {
 330		local_skb = skb_clone(skb, GFP_ATOMIC);
 331		if (!local_skb)
 332			goto drop;
 333
 334		local_skb->dev = dev;
 335
 336		ret = iphc_decompress(local_skb, dev, peer);
 337		if (ret < 0) {
 338			BT_DBG("iphc_decompress failed: %d", ret);
 339			kfree_skb(local_skb);
 340			goto drop;
 341		}
 342
 343		local_skb->protocol = htons(ETH_P_IPV6);
 344		local_skb->pkt_type = PACKET_HOST;
 345
 346		if (give_skb_to_upper(local_skb, dev)
 347				!= NET_RX_SUCCESS) {
 348			kfree_skb(local_skb);
 349			goto drop;
 350		}
 351
 352		dev->stats.rx_bytes += skb->len;
 353		dev->stats.rx_packets++;
 354
 355		consume_skb(local_skb);
 356		consume_skb(skb);
 357	} else {
 358		BT_DBG("unknown packet type");
 359		goto drop;
 360	}
 361
 362	return NET_RX_SUCCESS;
 363
 364drop:
 365	dev->stats.rx_dropped++;
 366	return NET_RX_DROP;
 367}
 368
 369/* Packet from BT LE device */
 370static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
 371{
 372	struct lowpan_btle_dev *dev;
 373	struct lowpan_peer *peer;
 374	int err;
 375
 376	peer = lookup_peer(chan->conn);
 377	if (!peer)
 378		return -ENOENT;
 379
 380	dev = lookup_dev(chan->conn);
 381	if (!dev || !dev->netdev)
 382		return -ENOENT;
 383
 384	err = recv_pkt(skb, dev->netdev, peer);
 385	if (err) {
 386		BT_DBG("recv pkt %d", err);
 387		err = -EAGAIN;
 388	}
 389
 390	return err;
 391}
 392
 393static int setup_header(struct sk_buff *skb, struct net_device *netdev,
 394			bdaddr_t *peer_addr, u8 *peer_addr_type)
 395{
 396	struct in6_addr ipv6_daddr;
 397	struct ipv6hdr *hdr;
 398	struct lowpan_btle_dev *dev;
 399	struct lowpan_peer *peer;
 400	u8 *daddr;
 401	int err, status = 0;
 402
 403	hdr = ipv6_hdr(skb);
 404
 405	dev = lowpan_btle_dev(netdev);
 406
 407	memcpy(&ipv6_daddr, &hdr->daddr, sizeof(ipv6_daddr));
 408
 409	if (ipv6_addr_is_multicast(&ipv6_daddr)) {
 410		lowpan_cb(skb)->chan = NULL;
 411		daddr = NULL;
 412	} else {
 413		BT_DBG("dest IP %pI6c", &ipv6_daddr);
 414
 415		/* The packet might be sent to 6lowpan interface
 416		 * because of routing (either via default route
 417		 * or user set route) so get peer according to
 418		 * the destination address.
 419		 */
 420		peer = peer_lookup_dst(dev, &ipv6_daddr, skb);
 421		if (!peer) {
 422			BT_DBG("no such peer");
 423			return -ENOENT;
 424		}
 425
 426		daddr = peer->lladdr;
 427		*peer_addr = peer->chan->dst;
 428		*peer_addr_type = peer->chan->dst_type;
 429		lowpan_cb(skb)->chan = peer->chan;
 430
 431		status = 1;
 432	}
 433
 434	lowpan_header_compress(skb, netdev, daddr, dev->netdev->dev_addr);
 435
 436	err = dev_hard_header(skb, netdev, ETH_P_IPV6, NULL, NULL, 0);
 437	if (err < 0)
 438		return err;
 439
 440	return status;
 441}
 442
 443static int header_create(struct sk_buff *skb, struct net_device *netdev,
 444			 unsigned short type, const void *_daddr,
 445			 const void *_saddr, unsigned int len)
 446{
 447	if (type != ETH_P_IPV6)
 448		return -EINVAL;
 449
 450	return 0;
 451}
 452
 453/* Packet to BT LE device */
 454static int send_pkt(struct l2cap_chan *chan, struct sk_buff *skb,
 455		    struct net_device *netdev)
 456{
 457	struct msghdr msg;
 458	struct kvec iv;
 459	int err;
 460
 461	/* Remember the skb so that we can send EAGAIN to the caller if
 462	 * we run out of credits.
 463	 */
 464	chan->data = skb;
 465
 466	iv.iov_base = skb->data;
 467	iv.iov_len = skb->len;
 468
 469	memset(&msg, 0, sizeof(msg));
 470	iov_iter_kvec(&msg.msg_iter, WRITE | ITER_KVEC, &iv, 1, skb->len);
 471
 472	err = l2cap_chan_send(chan, &msg, skb->len);
 473	if (err > 0) {
 474		netdev->stats.tx_bytes += err;
 475		netdev->stats.tx_packets++;
 476		return 0;
 477	}
 478
 479	if (err < 0)
 480		netdev->stats.tx_errors++;
 481
 482	return err;
 483}
 484
 485static int send_mcast_pkt(struct sk_buff *skb, struct net_device *netdev)
 486{
 487	struct sk_buff *local_skb;
 488	struct lowpan_btle_dev *entry;
 489	int err = 0;
 490
 491	rcu_read_lock();
 492
 493	list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 494		struct lowpan_peer *pentry;
 495		struct lowpan_btle_dev *dev;
 496
 497		if (entry->netdev != netdev)
 498			continue;
 499
 500		dev = lowpan_btle_dev(entry->netdev);
 501
 502		list_for_each_entry_rcu(pentry, &dev->peers, list) {
 503			int ret;
 504
 505			local_skb = skb_clone(skb, GFP_ATOMIC);
 506
 507			BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
 508			       netdev->name,
 509			       &pentry->chan->dst, pentry->chan->dst_type,
 510			       &pentry->peer_addr, pentry->chan);
 511			ret = send_pkt(pentry->chan, local_skb, netdev);
 512			if (ret < 0)
 513				err = ret;
 514
 515			kfree_skb(local_skb);
 516		}
 517	}
 518
 519	rcu_read_unlock();
 520
 521	return err;
 522}
 523
 524static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev)
 525{
 526	int err = 0;
 527	bdaddr_t addr;
 528	u8 addr_type;
 529
 530	/* We must take a copy of the skb before we modify/replace the ipv6
 531	 * header as the header could be used elsewhere
 532	 */
 533	skb = skb_unshare(skb, GFP_ATOMIC);
 534	if (!skb)
 535		return NET_XMIT_DROP;
 536
 537	/* Return values from setup_header()
 538	 *  <0 - error, packet is dropped
 539	 *   0 - this is a multicast packet
 540	 *   1 - this is unicast packet
 541	 */
 542	err = setup_header(skb, netdev, &addr, &addr_type);
 543	if (err < 0) {
 544		kfree_skb(skb);
 545		return NET_XMIT_DROP;
 546	}
 547
 548	if (err) {
 549		if (lowpan_cb(skb)->chan) {
 550			BT_DBG("xmit %s to %pMR type %d IP %pI6c chan %p",
 551			       netdev->name, &addr, addr_type,
 552			       &lowpan_cb(skb)->addr, lowpan_cb(skb)->chan);
 553			err = send_pkt(lowpan_cb(skb)->chan, skb, netdev);
 554		} else {
 555			err = -ENOENT;
 556		}
 557	} else {
 558		/* We need to send the packet to every device behind this
 559		 * interface.
 560		 */
 561		err = send_mcast_pkt(skb, netdev);
 562	}
 563
 564	dev_kfree_skb(skb);
 565
 566	if (err)
 567		BT_DBG("ERROR: xmit failed (%d)", err);
 568
 569	return err < 0 ? NET_XMIT_DROP : err;
 570}
 571
 572static int bt_dev_init(struct net_device *dev)
 573{
 574	netdev_lockdep_set_classes(dev);
 575
 576	return 0;
 577}
 578
 579static const struct net_device_ops netdev_ops = {
 580	.ndo_init		= bt_dev_init,
 581	.ndo_start_xmit		= bt_xmit,
 582};
 583
 584static struct header_ops header_ops = {
 585	.create	= header_create,
 586};
 587
 588static void netdev_setup(struct net_device *dev)
 589{
 590	dev->hard_header_len	= 0;
 591	dev->needed_tailroom	= 0;
 592	dev->flags		= IFF_RUNNING | IFF_MULTICAST;
 593	dev->watchdog_timeo	= 0;
 594	dev->tx_queue_len	= DEFAULT_TX_QUEUE_LEN;
 595
 596	dev->netdev_ops		= &netdev_ops;
 597	dev->header_ops		= &header_ops;
 598	dev->needs_free_netdev	= true;
 599}
 600
 601static struct device_type bt_type = {
 602	.name	= "bluetooth",
 603};
 604
 605static void ifup(struct net_device *netdev)
 606{
 607	int err;
 608
 609	rtnl_lock();
 610	err = dev_open(netdev);
 611	if (err < 0)
 612		BT_INFO("iface %s cannot be opened (%d)", netdev->name, err);
 613	rtnl_unlock();
 614}
 615
 616static void ifdown(struct net_device *netdev)
 617{
 618	rtnl_lock();
 619	dev_close(netdev);
 620	rtnl_unlock();
 621}
 622
 623static void do_notify_peers(struct work_struct *work)
 624{
 625	struct lowpan_btle_dev *dev = container_of(work, struct lowpan_btle_dev,
 626						   notify_peers.work);
 627
 628	netdev_notify_peers(dev->netdev); /* send neighbour adv at startup */
 629}
 630
 631static bool is_bt_6lowpan(struct hci_conn *hcon)
 632{
 633	if (hcon->type != LE_LINK)
 634		return false;
 635
 636	if (!enable_6lowpan)
 637		return false;
 638
 639	return true;
 640}
 641
 642static struct l2cap_chan *chan_create(void)
 643{
 644	struct l2cap_chan *chan;
 645
 646	chan = l2cap_chan_create();
 647	if (!chan)
 648		return NULL;
 649
 650	l2cap_chan_set_defaults(chan);
 651
 652	chan->chan_type = L2CAP_CHAN_CONN_ORIENTED;
 653	chan->mode = L2CAP_MODE_LE_FLOWCTL;
 654	chan->imtu = 1280;
 655
 656	return chan;
 657}
 658
 659static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan,
 660					struct lowpan_btle_dev *dev,
 661					bool new_netdev)
 662{
 663	struct lowpan_peer *peer;
 664
 665	peer = kzalloc(sizeof(*peer), GFP_ATOMIC);
 666	if (!peer)
 667		return NULL;
 668
 669	peer->chan = chan;
 670	memset(&peer->peer_addr, 0, sizeof(struct in6_addr));
 671
 672	baswap((void *)peer->lladdr, &chan->dst);
 673
 674	lowpan_iphc_uncompress_eui48_lladdr(&peer->peer_addr, peer->lladdr);
 675
 676	spin_lock(&devices_lock);
 677	INIT_LIST_HEAD(&peer->list);
 678	peer_add(dev, peer);
 679	spin_unlock(&devices_lock);
 680
 681	/* Notifying peers about us needs to be done without locks held */
 682	if (new_netdev)
 683		INIT_DELAYED_WORK(&dev->notify_peers, do_notify_peers);
 684	schedule_delayed_work(&dev->notify_peers, msecs_to_jiffies(100));
 685
 686	return peer->chan;
 687}
 688
 689static int setup_netdev(struct l2cap_chan *chan, struct lowpan_btle_dev **dev)
 690{
 691	struct net_device *netdev;
 692	int err = 0;
 693
 694	netdev = alloc_netdev(LOWPAN_PRIV_SIZE(sizeof(struct lowpan_btle_dev)),
 695			      IFACE_NAME_TEMPLATE, NET_NAME_UNKNOWN,
 696			      netdev_setup);
 697	if (!netdev)
 698		return -ENOMEM;
 699
 700	netdev->addr_assign_type = NET_ADDR_PERM;
 701	baswap((void *)netdev->dev_addr, &chan->src);
 702
 703	netdev->netdev_ops = &netdev_ops;
 704	SET_NETDEV_DEV(netdev, &chan->conn->hcon->hdev->dev);
 705	SET_NETDEV_DEVTYPE(netdev, &bt_type);
 706
 707	*dev = lowpan_btle_dev(netdev);
 708	(*dev)->netdev = netdev;
 709	(*dev)->hdev = chan->conn->hcon->hdev;
 710	INIT_LIST_HEAD(&(*dev)->peers);
 711
 712	spin_lock(&devices_lock);
 713	INIT_LIST_HEAD(&(*dev)->list);
 714	list_add_rcu(&(*dev)->list, &bt_6lowpan_devices);
 715	spin_unlock(&devices_lock);
 716
 717	err = lowpan_register_netdev(netdev, LOWPAN_LLTYPE_BTLE);
 718	if (err < 0) {
 719		BT_INFO("register_netdev failed %d", err);
 720		spin_lock(&devices_lock);
 721		list_del_rcu(&(*dev)->list);
 722		spin_unlock(&devices_lock);
 723		free_netdev(netdev);
 724		goto out;
 725	}
 726
 727	BT_DBG("ifindex %d peer bdaddr %pMR type %d my addr %pMR type %d",
 728	       netdev->ifindex, &chan->dst, chan->dst_type,
 729	       &chan->src, chan->src_type);
 730	set_bit(__LINK_STATE_PRESENT, &netdev->state);
 731
 732	return 0;
 733
 734out:
 735	return err;
 736}
 737
 738static inline void chan_ready_cb(struct l2cap_chan *chan)
 739{
 740	struct lowpan_btle_dev *dev;
 741	bool new_netdev = false;
 742
 743	dev = lookup_dev(chan->conn);
 744
 745	BT_DBG("chan %p conn %p dev %p", chan, chan->conn, dev);
 746
 747	if (!dev) {
 748		if (setup_netdev(chan, &dev) < 0) {
 749			l2cap_chan_del(chan, -ENOENT);
 750			return;
 751		}
 752		new_netdev = true;
 753	}
 754
 755	if (!try_module_get(THIS_MODULE))
 756		return;
 757
 758	add_peer_chan(chan, dev, new_netdev);
 759	ifup(dev->netdev);
 760}
 761
 762static inline struct l2cap_chan *chan_new_conn_cb(struct l2cap_chan *pchan)
 763{
 764	struct l2cap_chan *chan;
 765
 766	chan = chan_create();
 767	if (!chan)
 768		return NULL;
 769
 770	chan->ops = pchan->ops;
 771
 772	BT_DBG("chan %p pchan %p", chan, pchan);
 773
 774	return chan;
 775}
 776
 777static void delete_netdev(struct work_struct *work)
 778{
 779	struct lowpan_btle_dev *entry = container_of(work,
 780						     struct lowpan_btle_dev,
 781						     delete_netdev);
 782
 783	lowpan_unregister_netdev(entry->netdev);
 784
 785	/* The entry pointer is deleted by the netdev destructor. */
 786}
 787
 788static void chan_close_cb(struct l2cap_chan *chan)
 789{
 790	struct lowpan_btle_dev *entry;
 791	struct lowpan_btle_dev *dev = NULL;
 792	struct lowpan_peer *peer;
 793	int err = -ENOENT;
 794	bool last = false, remove = true;
 795
 796	BT_DBG("chan %p conn %p", chan, chan->conn);
 797
 798	if (chan->conn && chan->conn->hcon) {
 799		if (!is_bt_6lowpan(chan->conn->hcon))
 800			return;
 801
 802		/* If conn is set, then the netdev is also there and we should
 803		 * not remove it.
 804		 */
 805		remove = false;
 806	}
 807
 808	spin_lock(&devices_lock);
 809
 810	list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
 811		dev = lowpan_btle_dev(entry->netdev);
 812		peer = __peer_lookup_chan(dev, chan);
 813		if (peer) {
 814			last = peer_del(dev, peer);
 815			err = 0;
 816
 817			BT_DBG("dev %p removing %speer %p", dev,
 818			       last ? "last " : "1 ", peer);
 819			BT_DBG("chan %p orig refcnt %d", chan,
 820			       kref_read(&chan->kref));
 821
 822			l2cap_chan_put(chan);
 823			break;
 824		}
 825	}
 826
 827	if (!err && last && dev && !atomic_read(&dev->peer_count)) {
 828		spin_unlock(&devices_lock);
 829
 830		cancel_delayed_work_sync(&dev->notify_peers);
 831
 832		ifdown(dev->netdev);
 833
 834		if (remove) {
 835			INIT_WORK(&entry->delete_netdev, delete_netdev);
 836			schedule_work(&entry->delete_netdev);
 837		}
 838	} else {
 839		spin_unlock(&devices_lock);
 840	}
 841
 842	return;
 843}
 844
 845static void chan_state_change_cb(struct l2cap_chan *chan, int state, int err)
 846{
 847	BT_DBG("chan %p conn %p state %s err %d", chan, chan->conn,
 848	       state_to_string(state), err);
 849}
 850
 851static struct sk_buff *chan_alloc_skb_cb(struct l2cap_chan *chan,
 852					 unsigned long hdr_len,
 853					 unsigned long len, int nb)
 854{
 855	/* Note that we must allocate using GFP_ATOMIC here as
 856	 * this function is called originally from netdev hard xmit
 857	 * function in atomic context.
 858	 */
 859	return bt_skb_alloc(hdr_len + len, GFP_ATOMIC);
 860}
 861
 862static void chan_suspend_cb(struct l2cap_chan *chan)
 863{
 864	struct lowpan_btle_dev *dev;
 865
 866	BT_DBG("chan %p suspend", chan);
 867
 868	dev = lookup_dev(chan->conn);
 869	if (!dev || !dev->netdev)
 870		return;
 871
 872	netif_stop_queue(dev->netdev);
 873}
 874
 875static void chan_resume_cb(struct l2cap_chan *chan)
 876{
 877	struct lowpan_btle_dev *dev;
 878
 879	BT_DBG("chan %p resume", chan);
 880
 881	dev = lookup_dev(chan->conn);
 882	if (!dev || !dev->netdev)
 883		return;
 884
 885	netif_wake_queue(dev->netdev);
 886}
 887
 888static long chan_get_sndtimeo_cb(struct l2cap_chan *chan)
 889{
 890	return L2CAP_CONN_TIMEOUT;
 891}
 892
 893static const struct l2cap_ops bt_6lowpan_chan_ops = {
 894	.name			= "L2CAP 6LoWPAN channel",
 895	.new_connection		= chan_new_conn_cb,
 896	.recv			= chan_recv_cb,
 897	.close			= chan_close_cb,
 898	.state_change		= chan_state_change_cb,
 899	.ready			= chan_ready_cb,
 900	.resume			= chan_resume_cb,
 901	.suspend		= chan_suspend_cb,
 902	.get_sndtimeo		= chan_get_sndtimeo_cb,
 903	.alloc_skb		= chan_alloc_skb_cb,
 904
 905	.teardown		= l2cap_chan_no_teardown,
 906	.defer			= l2cap_chan_no_defer,
 907	.set_shutdown		= l2cap_chan_no_set_shutdown,
 908};
 909
 910static inline __u8 bdaddr_type(__u8 type)
 911{
 912	if (type == ADDR_LE_DEV_PUBLIC)
 913		return BDADDR_LE_PUBLIC;
 914	else
 915		return BDADDR_LE_RANDOM;
 916}
 917
 918static int bt_6lowpan_connect(bdaddr_t *addr, u8 dst_type)
 919{
 920	struct l2cap_chan *chan;
 921	int err;
 922
 923	chan = chan_create();
 924	if (!chan)
 925		return -EINVAL;
 926
 927	chan->ops = &bt_6lowpan_chan_ops;
 928
 929	err = l2cap_chan_connect(chan, cpu_to_le16(L2CAP_PSM_IPSP), 0,
 930				 addr, dst_type);
 931
 932	BT_DBG("chan %p err %d", chan, err);
 933	if (err < 0)
 934		l2cap_chan_put(chan);
 935
 936	return err;
 937}
 938
 939static int bt_6lowpan_disconnect(struct l2cap_conn *conn, u8 dst_type)
 940{
 941	struct lowpan_peer *peer;
 942
 943	BT_DBG("conn %p dst type %d", conn, dst_type);
 944
 945	peer = lookup_peer(conn);
 946	if (!peer)
 947		return -ENOENT;
 948
 949	BT_DBG("peer %p chan %p", peer, peer->chan);
 950
 951	l2cap_chan_close(peer->chan, ENOENT);
 952
 953	return 0;
 954}
 955
 956static struct l2cap_chan *bt_6lowpan_listen(void)
 957{
 958	bdaddr_t *addr = BDADDR_ANY;
 959	struct l2cap_chan *chan;
 960	int err;
 961
 962	if (!enable_6lowpan)
 963		return NULL;
 964
 965	chan = chan_create();
 966	if (!chan)
 967		return NULL;
 968
 969	chan->ops = &bt_6lowpan_chan_ops;
 970	chan->state = BT_LISTEN;
 971	chan->src_type = BDADDR_LE_PUBLIC;
 972
 973	atomic_set(&chan->nesting, L2CAP_NESTING_PARENT);
 974
 975	BT_DBG("chan %p src type %d", chan, chan->src_type);
 976
 977	err = l2cap_add_psm(chan, addr, cpu_to_le16(L2CAP_PSM_IPSP));
 978	if (err) {
 979		l2cap_chan_put(chan);
 980		BT_ERR("psm cannot be added err %d", err);
 981		return NULL;
 982	}
 983
 984	return chan;
 985}
 986
 987static int get_l2cap_conn(char *buf, bdaddr_t *addr, u8 *addr_type,
 988			  struct l2cap_conn **conn)
 989{
 990	struct hci_conn *hcon;
 991	struct hci_dev *hdev;
 992	int n;
 993
 994	n = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx %hhu",
 995		   &addr->b[5], &addr->b[4], &addr->b[3],
 996		   &addr->b[2], &addr->b[1], &addr->b[0],
 997		   addr_type);
 998
 999	if (n < 7)
1000		return -EINVAL;
1001
1002	/* The LE_PUBLIC address type is ignored because of BDADDR_ANY */
1003	hdev = hci_get_route(addr, BDADDR_ANY, BDADDR_LE_PUBLIC);
1004	if (!hdev)
1005		return -ENOENT;
1006
1007	hci_dev_lock(hdev);
1008	hcon = hci_conn_hash_lookup_le(hdev, addr, *addr_type);
1009	hci_dev_unlock(hdev);
1010
1011	if (!hcon)
1012		return -ENOENT;
1013
1014	*conn = (struct l2cap_conn *)hcon->l2cap_data;
1015
1016	BT_DBG("conn %p dst %pMR type %d", *conn, &hcon->dst, hcon->dst_type);
1017
1018	return 0;
1019}
1020
1021static void disconnect_all_peers(void)
1022{
1023	struct lowpan_btle_dev *entry;
1024	struct lowpan_peer *peer, *tmp_peer, *new_peer;
1025	struct list_head peers;
1026
1027	INIT_LIST_HEAD(&peers);
1028
1029	/* We make a separate list of peers as the close_cb() will
1030	 * modify the device peers list so it is better not to mess
1031	 * with the same list at the same time.
1032	 */
1033
1034	rcu_read_lock();
1035
1036	list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1037		list_for_each_entry_rcu(peer, &entry->peers, list) {
1038			new_peer = kmalloc(sizeof(*new_peer), GFP_ATOMIC);
1039			if (!new_peer)
1040				break;
1041
1042			new_peer->chan = peer->chan;
1043			INIT_LIST_HEAD(&new_peer->list);
1044
1045			list_add(&new_peer->list, &peers);
1046		}
1047	}
1048
1049	rcu_read_unlock();
1050
1051	spin_lock(&devices_lock);
1052	list_for_each_entry_safe(peer, tmp_peer, &peers, list) {
1053		l2cap_chan_close(peer->chan, ENOENT);
1054
1055		list_del_rcu(&peer->list);
1056		kfree_rcu(peer, rcu);
1057	}
1058	spin_unlock(&devices_lock);
1059}
1060
1061struct set_enable {
1062	struct work_struct work;
1063	bool flag;
1064};
1065
1066static void do_enable_set(struct work_struct *work)
1067{
1068	struct set_enable *set_enable = container_of(work,
1069						     struct set_enable, work);
1070
1071	if (!set_enable->flag || enable_6lowpan != set_enable->flag)
1072		/* Disconnect existing connections if 6lowpan is
1073		 * disabled
1074		 */
1075		disconnect_all_peers();
1076
1077	enable_6lowpan = set_enable->flag;
1078
1079	if (listen_chan) {
1080		l2cap_chan_close(listen_chan, 0);
1081		l2cap_chan_put(listen_chan);
1082	}
1083
1084	listen_chan = bt_6lowpan_listen();
1085
1086	kfree(set_enable);
1087}
1088
1089static int lowpan_enable_set(void *data, u64 val)
1090{
1091	struct set_enable *set_enable;
1092
1093	set_enable = kzalloc(sizeof(*set_enable), GFP_KERNEL);
1094	if (!set_enable)
1095		return -ENOMEM;
1096
1097	set_enable->flag = !!val;
1098	INIT_WORK(&set_enable->work, do_enable_set);
1099
1100	schedule_work(&set_enable->work);
1101
1102	return 0;
1103}
1104
1105static int lowpan_enable_get(void *data, u64 *val)
1106{
1107	*val = enable_6lowpan;
1108	return 0;
1109}
1110
1111DEFINE_SIMPLE_ATTRIBUTE(lowpan_enable_fops, lowpan_enable_get,
1112			lowpan_enable_set, "%llu\n");
1113
1114static ssize_t lowpan_control_write(struct file *fp,
1115				    const char __user *user_buffer,
1116				    size_t count,
1117				    loff_t *position)
1118{
1119	char buf[32];
1120	size_t buf_size = min(count, sizeof(buf) - 1);
1121	int ret;
1122	bdaddr_t addr;
1123	u8 addr_type;
1124	struct l2cap_conn *conn = NULL;
1125
1126	if (copy_from_user(buf, user_buffer, buf_size))
1127		return -EFAULT;
1128
1129	buf[buf_size] = '\0';
1130
1131	if (memcmp(buf, "connect ", 8) == 0) {
1132		ret = get_l2cap_conn(&buf[8], &addr, &addr_type, &conn);
1133		if (ret == -EINVAL)
1134			return ret;
1135
1136		if (listen_chan) {
1137			l2cap_chan_close(listen_chan, 0);
1138			l2cap_chan_put(listen_chan);
1139			listen_chan = NULL;
1140		}
1141
1142		if (conn) {
1143			struct lowpan_peer *peer;
1144
1145			if (!is_bt_6lowpan(conn->hcon))
1146				return -EINVAL;
1147
1148			peer = lookup_peer(conn);
1149			if (peer) {
1150				BT_DBG("6LoWPAN connection already exists");
1151				return -EALREADY;
1152			}
1153
1154			BT_DBG("conn %p dst %pMR type %d user %d", conn,
1155			       &conn->hcon->dst, conn->hcon->dst_type,
1156			       addr_type);
1157		}
1158
1159		ret = bt_6lowpan_connect(&addr, addr_type);
1160		if (ret < 0)
1161			return ret;
1162
1163		return count;
1164	}
1165
1166	if (memcmp(buf, "disconnect ", 11) == 0) {
1167		ret = get_l2cap_conn(&buf[11], &addr, &addr_type, &conn);
1168		if (ret < 0)
1169			return ret;
1170
1171		ret = bt_6lowpan_disconnect(conn, addr_type);
1172		if (ret < 0)
1173			return ret;
1174
1175		return count;
1176	}
1177
1178	return count;
1179}
1180
1181static int lowpan_control_show(struct seq_file *f, void *ptr)
1182{
1183	struct lowpan_btle_dev *entry;
1184	struct lowpan_peer *peer;
1185
1186	spin_lock(&devices_lock);
1187
1188	list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1189		list_for_each_entry(peer, &entry->peers, list)
1190			seq_printf(f, "%pMR (type %u)\n",
1191				   &peer->chan->dst, peer->chan->dst_type);
1192	}
1193
1194	spin_unlock(&devices_lock);
1195
1196	return 0;
1197}
1198
1199static int lowpan_control_open(struct inode *inode, struct file *file)
1200{
1201	return single_open(file, lowpan_control_show, inode->i_private);
1202}
1203
1204static const struct file_operations lowpan_control_fops = {
1205	.open		= lowpan_control_open,
1206	.read		= seq_read,
1207	.write		= lowpan_control_write,
1208	.llseek		= seq_lseek,
1209	.release	= single_release,
1210};
1211
1212static void disconnect_devices(void)
1213{
1214	struct lowpan_btle_dev *entry, *tmp, *new_dev;
1215	struct list_head devices;
1216
1217	INIT_LIST_HEAD(&devices);
1218
1219	/* We make a separate list of devices because the unregister_netdev()
1220	 * will call device_event() which will also want to modify the same
1221	 * devices list.
1222	 */
1223
1224	rcu_read_lock();
1225
1226	list_for_each_entry_rcu(entry, &bt_6lowpan_devices, list) {
1227		new_dev = kmalloc(sizeof(*new_dev), GFP_ATOMIC);
1228		if (!new_dev)
1229			break;
1230
1231		new_dev->netdev = entry->netdev;
1232		INIT_LIST_HEAD(&new_dev->list);
1233
1234		list_add_rcu(&new_dev->list, &devices);
1235	}
1236
1237	rcu_read_unlock();
1238
1239	list_for_each_entry_safe(entry, tmp, &devices, list) {
1240		ifdown(entry->netdev);
1241		BT_DBG("Unregistering netdev %s %p",
1242		       entry->netdev->name, entry->netdev);
1243		lowpan_unregister_netdev(entry->netdev);
1244		kfree(entry);
1245	}
1246}
1247
1248static int device_event(struct notifier_block *unused,
1249			unsigned long event, void *ptr)
1250{
1251	struct net_device *netdev = netdev_notifier_info_to_dev(ptr);
1252	struct lowpan_btle_dev *entry;
1253
1254	if (netdev->type != ARPHRD_6LOWPAN)
1255		return NOTIFY_DONE;
1256
1257	switch (event) {
1258	case NETDEV_UNREGISTER:
1259		spin_lock(&devices_lock);
1260		list_for_each_entry(entry, &bt_6lowpan_devices, list) {
1261			if (entry->netdev == netdev) {
1262				BT_DBG("Unregistered netdev %s %p",
1263				       netdev->name, netdev);
1264				list_del(&entry->list);
1265				break;
1266			}
1267		}
1268		spin_unlock(&devices_lock);
1269		break;
1270	}
1271
1272	return NOTIFY_DONE;
1273}
1274
1275static struct notifier_block bt_6lowpan_dev_notifier = {
1276	.notifier_call = device_event,
1277};
1278
1279static int __init bt_6lowpan_init(void)
1280{
1281	lowpan_enable_debugfs = debugfs_create_file("6lowpan_enable", 0644,
1282						    bt_debugfs, NULL,
1283						    &lowpan_enable_fops);
 
1284	lowpan_control_debugfs = debugfs_create_file("6lowpan_control", 0644,
1285						     bt_debugfs, NULL,
1286						     &lowpan_control_fops);
1287
1288	return register_netdevice_notifier(&bt_6lowpan_dev_notifier);
1289}
1290
1291static void __exit bt_6lowpan_exit(void)
1292{
1293	debugfs_remove(lowpan_enable_debugfs);
1294	debugfs_remove(lowpan_control_debugfs);
1295
1296	if (listen_chan) {
1297		l2cap_chan_close(listen_chan, 0);
1298		l2cap_chan_put(listen_chan);
1299	}
1300
1301	disconnect_devices();
1302
1303	unregister_netdevice_notifier(&bt_6lowpan_dev_notifier);
1304}
1305
1306module_init(bt_6lowpan_init);
1307module_exit(bt_6lowpan_exit);
1308
1309MODULE_AUTHOR("Jukka Rissanen <jukka.rissanen@linux.intel.com>");
1310MODULE_DESCRIPTION("Bluetooth 6LoWPAN");
1311MODULE_VERSION(VERSION);
1312MODULE_LICENSE("GPL");