6lowpan: Fix IID format for Bluetooth

According to RFC 7668 U/L bit shall not be used:

https://wiki.tools.ietf.org/html/rfc7668#section-3.2.2 [Page 10]:

In the figure, letter 'b' represents a bit from the
Bluetooth device address, copied as is without any changes on any
bit. This means that no bit in the IID indicates whether the
underlying Bluetooth device address is public or random.

|0 1|1 3|3 4|4 6|
|0 5|6 1|2 7|8 3|
+----------------+----------------+----------------+----------------+
|bbbbbbbbbbbbbbbb|bbbbbbbb11111111|11111110bbbbbbbb|bbbbbbbbbbbbbbbb|
+----------------+----------------+----------------+----------------+

Because of this the code cannot figure out the address type from the IP
address anymore thus it makes no sense to use peer_lookup_ba as it needs
the peer address type.

Signed-off-by: Luiz Augusto von Dentz <[e-mail]>
Reviewed-by: Stefan Schmidt <[e-mail]>
Acked-by: Jukka Rissanen <[e-mail]>
Signed-off-by: Marcel Holtmann <[e-mail]>

include/net/6lowpan.h

···
 	ipaddr->s6_addr[11] = 0xFF;
 	ipaddr->s6_addr[12] = 0xFE;
 	memcpy(&ipaddr->s6_addr[13], lladdr + 3, 3);
-	/* second bit-flip (Universe/Local)
-	 * is done according RFC2464
-	 */
-	ipaddr->s6_addr[8] ^= 0x02;
 }
 
 #ifdef DEBUG

net/bluetooth/6lowpan.c

···
 	return err;
 }
 
-static u8 get_addr_type_from_eui64(u8 byte)
-{
-	/* Is universal(0) or local(1) bit */
-	return ((byte & 0x02) ? BDADDR_LE_RANDOM : BDADDR_LE_PUBLIC);
-}
-
-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];
-	addr->b[2] = eui64[5];
-	addr->b[3] = eui64[2];
-	addr->b[4] = eui64[1];
-	addr->b[5] = eui64[0];
-}
-
-static void convert_dest_bdaddr(struct in6_addr *ip6_daddr,
-				bdaddr_t *addr, u8 *addr_type)
-{
-	copy_to_bdaddr(ip6_daddr, addr);
-
-	/* 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 setup_header(struct sk_buff *skb, struct net_device *netdev,
 			bdaddr_t *peer_addr, u8 *peer_addr_type)
 {
···
 	struct ipv6hdr *hdr;
 	struct lowpan_btle_dev *dev;
 	struct lowpan_peer *peer;
-	bdaddr_t addr, *any = BDADDR_ANY;
-	u8 *daddr = any->b;
+	u8 *daddr;
 	int err, status = 0;
 
 	hdr = ipv6_hdr(skb);
···
 
 	if (ipv6_addr_is_multicast(&ipv6_daddr)) {
 		lowpan_cb(skb)->chan = NULL;
+		daddr = NULL;
 	} else {
-		u8 addr_type;
+		BT_DBG("dest IP %pI6c", &ipv6_daddr);
 
-		/* Get destination BT device from skb.
-		 * If there is no such peer then discard the packet.
+		/* The packet might be sent to 6lowpan interface
+		 * because of routing (either via default route
+		 * or user set route) so get peer according to
+		 * the destination address.
 		 */
-		convert_dest_bdaddr(&ipv6_daddr, &addr, &addr_type);
-
-		BT_DBG("dest addr %pMR type %d IP %pI6c", &addr,
-		       addr_type, &ipv6_daddr);
-
-		peer = peer_lookup_ba(dev, &addr, addr_type);
+		peer = peer_lookup_dst(dev, &ipv6_daddr, skb);
 		if (!peer) {
-			/* The packet might be sent to 6lowpan interface
-			 * because of routing (either via default route
-			 * or user set route) so get peer according to
-			 * the destination address.
-			 */
-			peer = peer_lookup_dst(dev, &ipv6_daddr, skb);
-			if (!peer) {
-				BT_DBG("no such peer %pMR found", &addr);
-				return -ENOENT;
-			}
+			BT_DBG("no such peer");
+			return -ENOENT;
 		}
 
 		daddr = peer->lladdr;
-		*peer_addr = addr;
-		*peer_addr_type = addr_type;
+		peer_addr = &peer->chan->dst;
+		*peer_addr_type = peer->chan->dst_type;
 		lowpan_cb(skb)->chan = peer->chan;
 
 		status = 1;
···
 	return chan;
 }
 
-static void set_ip_addr_bits(u8 addr_type, u8 *addr)
-{
-	if (addr_type == BDADDR_LE_PUBLIC)
-		*addr |= 0x02;
-	else
-		*addr &= ~0x02;
-}
-
 static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan,
 					struct lowpan_btle_dev *dev)
 {
···
 	baswap((void *)peer->lladdr, &chan->dst);
 
 	lowpan_iphc_uncompress_eui48_lladdr(&peer->peer_addr, peer->lladdr);
-
-	/* IPv6 address needs to have the U/L bit set properly so toggle
-	 * it back here.
-	 */
-	set_ip_addr_bits(chan->dst_type, (u8 *)&peer->peer_addr.s6_addr + 8);
 
 	spin_lock(&devices_lock);
 	INIT_LIST_HEAD(&peer->list);

net/ipv6/addrconf.c

···
 {
 	switch (dev->addr_len) {
 	case ETH_ALEN:
-		return addrconf_ifid_eui48(eui, dev);
+		memcpy(eui, dev->dev_addr, 3);
+		eui[3] = 0xFF;
+		eui[4] = 0xFE;
+		memcpy(eui + 5, dev->dev_addr + 3, 3);
+		break;
 	case EUI64_ADDR_LEN:
 		memcpy(eui, dev->dev_addr, EUI64_ADDR_LEN);
 		eui[0] ^= 2;