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Date: Fri, 24 Feb 2017 15:00:12 +0100
From: Stefan Schmidt <stefan@....samsung.com>
To: Luiz Augusto von Dentz <luiz.dentz@...il.com>,
linux-bluetooth@...r.kernel.org
Cc: patrik.flykt@...ux.intel.com, jukka.rissanen@...ux.intel.com,
aar@...gutronix.de, linux-wpan@...r.kernel.org,
netdev@...r.kernel.org
Subject: Re: [PATCH v5 6/6] 6lowpan: Fix IID format for Bluetooth
Hello.
On 02/24/2017 01:14 PM, Luiz Augusto von Dentz wrote:
> From: Luiz Augusto von Dentz <luiz.von.dentz@...el.com>
>
> Accourding 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 <luiz.von.dentz@...el.com>
> ---
> include/net/6lowpan.h | 4 ---
> net/bluetooth/6lowpan.c | 79 ++++++++-----------------------------------------
> 2 files changed, 12 insertions(+), 71 deletions(-)
>
> diff --git a/include/net/6lowpan.h b/include/net/6lowpan.h
> index c5792cb..a713780 100644
> --- a/include/net/6lowpan.h
> +++ b/include/net/6lowpan.h
> @@ -211,10 +211,6 @@ static inline void lowpan_iphc_uncompress_eui48_lladdr(struct in6_addr *ipaddr,
> 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
> diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
> index 0b68cfc..ec89c55 100644
> --- a/net/bluetooth/6lowpan.c
> +++ b/net/bluetooth/6lowpan.c
> @@ -398,37 +398,6 @@ static int chan_recv_cb(struct l2cap_chan *chan, struct sk_buff *skb)
> 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)
> {
> @@ -436,8 +405,7 @@ static int setup_header(struct sk_buff *skb, struct net_device *netdev,
> 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);
> @@ -448,34 +416,24 @@ static int setup_header(struct sk_buff *skb, struct net_device *netdev,
>
> 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;
> @@ -717,14 +675,6 @@ static struct l2cap_chan *chan_create(void)
> 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)
> {
> @@ -741,11 +691,6 @@ static struct l2cap_chan *add_peer_chan(struct l2cap_chan *chan,
>
> 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);
> peer_add(dev, peer);
>
Reviewed-by: Stefan Schmidt <stefan@....samsung.com>
regards
Stefan Schmidt
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