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Commit 62bbd5b3 authored by Jukka Rissanen's avatar Jukka Rissanen Committed by Marcel Holtmann
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Bluetooth: 6LoWPAN: Fix MAC address universal/local bit handling 



The universal/local bit handling was incorrectly done in the code.

So when setting EUI address from BD address we do this:
- If BD address type is PUBLIC, then we clear the universal bit
  in EUI address. If the address type is RANDOM, then the universal
  bit is set (BT 6lowpan draft chapter 3.2.2)
- After this we invert the universal/local bit according to RFC 2464

When figuring out BD address we do the reverse:
- Take EUI address from stateless IPv6 address, invert the
  universal/local bit according to RFC 2464
- If universal bit is 1 in this modified EUI address, then address
  type is set to RANDOM, otherwise it is PUBLIC

Note that 6lowpan_iphc.[ch] does the final toggling of U/L bit
before sending or receiving the network packet.

Signed-off-by: default avatarJukka Rissanen <jukka.rissanen@linux.intel.com>
Signed-off-by: default avatarMarcel Holtmann <marcel@holtmann.org>
Cc: stable@vger.kernel.org
parent 7e3691e1

net/bluetooth/6lowpan.c

+35 −30
Original line number Diff line number Diff line
@@ -420,12 +420,18 @@ static int conn_send(struct l2cap_conn *conn, 
	return 0;

}



static void get_dest_bdaddr(struct in6_addr *ip6_daddr,

			    bdaddr_t *addr, u8 *addr_type)

static u8 get_addr_type_from_eui64(u8 byte)

{

	u8 *eui64;

	/* Is universal(0) or local(1) bit,  */

	if (byte & 0x02)

		return ADDR_LE_DEV_RANDOM;



	return ADDR_LE_DEV_PUBLIC;

}



	eui64 = ip6_daddr->s6_addr + 8;

static void copy_to_bdaddr(struct in6_addr *ip6_daddr, bdaddr_t *addr)

{

	u8 *eui64 = ip6_daddr->s6_addr + 8;



	addr->b[0] = eui64[7];

	addr->b[1] = eui64[6];
@@ -433,16 +439,19 @@ static void get_dest_bdaddr(struct in6_addr *ip6_daddr, 
	addr->b[3] = eui64[2];

	addr->b[4] = eui64[1];

	addr->b[5] = eui64[0];

}



	addr->b[5] ^= 2;

static void convert_dest_bdaddr(struct in6_addr *ip6_daddr,

				bdaddr_t *addr, u8 *addr_type)

{

	copy_to_bdaddr(ip6_daddr, addr);



	/* Set universal/local bit to 0 */

	if (addr->b[5] & 1) {

		addr->b[5] &= ~1;

		*addr_type = ADDR_LE_DEV_PUBLIC;

	} else {

		*addr_type = ADDR_LE_DEV_RANDOM;

	}

	/* We need to toggle the U/L bit that we got from IPv6 address

	 * so that we get the proper address and type of the BD address.

	 */

	addr->b[5] ^= 0x02;



	*addr_type = get_addr_type_from_eui64(addr->b[5]);

}



static int header_create(struct sk_buff *skb, struct net_device *netdev,
@@ -473,9 +482,11 @@ static int header_create(struct sk_buff *skb, struct net_device *netdev, 
		/* Get destination BT device from skb.

		 * If there is no such peer then discard the packet.

		 */

		get_dest_bdaddr(&hdr->daddr, &addr, &addr_type);

		convert_dest_bdaddr(&hdr->daddr, &addr, &addr_type);



		BT_DBG("dest addr %pMR type %d", &addr, addr_type);

		BT_DBG("dest addr %pMR type %s IP %pI6c", &addr,

		       addr_type == ADDR_LE_DEV_PUBLIC ? "PUBLIC" : "RANDOM",

		       &hdr->daddr);



		read_lock_irqsave(&devices_lock, flags);

		peer = peer_lookup_ba(dev, &addr, addr_type);
@@ -556,7 +567,7 @@ static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev) 
	} else {

		unsigned long flags;



		get_dest_bdaddr(&lowpan_cb(skb)->addr, &addr, &addr_type);

		convert_dest_bdaddr(&lowpan_cb(skb)->addr, &addr, &addr_type);

		eui64_addr = lowpan_cb(skb)->addr.s6_addr + 8;

		dev = lowpan_dev(netdev);
@@ -564,8 +575,10 @@ static netdev_tx_t bt_xmit(struct sk_buff *skb, struct net_device *netdev) 
		peer = peer_lookup_ba(dev, &addr, addr_type);

		read_unlock_irqrestore(&devices_lock, flags);



		BT_DBG("xmit from %s to %pMR (%pI6c) peer %p", netdev->name,

		       &addr, &lowpan_cb(skb)->addr, peer);

		BT_DBG("xmit %s to %pMR type %s IP %pI6c peer %p",

		       netdev->name, &addr,

		       addr_type == ADDR_LE_DEV_PUBLIC ? "PUBLIC" : "RANDOM",

		       &lowpan_cb(skb)->addr, peer);



		if (peer && peer->conn)

			err = send_pkt(peer->conn, netdev->dev_addr,
@@ -620,13 +633,13 @@ static void set_addr(u8 *eui, u8 *addr, u8 addr_type) 
	eui[6] = addr[1];

	eui[7] = addr[0];



	eui[0] ^= 2;



	/* Universal/local bit set, RFC 4291 */

	/* Universal/local bit set, BT 6lowpan draft ch. 3.2.1 */

	if (addr_type == ADDR_LE_DEV_PUBLIC)

		eui[0] |= 1;

		eui[0] &= ~0x02;

	else

		eui[0] &= ~1;

		eui[0] |= 0x02;



	BT_DBG("type %d addr %*phC", addr_type, 8, eui);

}



static void set_dev_addr(struct net_device *netdev, bdaddr_t *addr,
@@ -634,7 +647,6 @@ static void set_dev_addr(struct net_device *netdev, bdaddr_t *addr, 
{

	netdev->addr_assign_type = NET_ADDR_PERM;

	set_addr(netdev->dev_addr, addr->b, addr_type);

	netdev->dev_addr[0] ^= 2;

}



static void ifup(struct net_device *netdev)
@@ -684,13 +696,6 @@ static int add_peer_conn(struct l2cap_conn *conn, struct lowpan_dev *dev) 


	memcpy(&peer->eui64_addr, (u8 *)&peer->peer_addr.s6_addr + 8,

	       EUI64_ADDR_LEN);

	peer->eui64_addr[0] ^= 2; /* second bit-flip (Universe/Local)

				   * is done according RFC2464

				   */



	raw_dump_inline(__func__, "peer IPv6 address",

			(unsigned char *)&peer->peer_addr, 16);

	raw_dump_inline(__func__, "peer EUI64 address", peer->eui64_addr, 8);



	write_lock_irqsave(&devices_lock, flags);

	INIT_LIST_HEAD(&peer->list);