[PATCH] Bluetooth: 6lowpan: Fix handling of uncompressed IPv6 packets

[PATCH] Bluetooth: 6lowpan: Fix handling of uncompressed IPv6 packets

[Lukasz Duda]

This patch fixes incorrect handling of the 6lowpan packets that contain
uncompressed IPv6 header.

RFC4944 specifies a special dispatch for 6lowpan to carry uncompressed
IPv6 header. This dispatch (1 byte long) has to be removed during
reception and skb data pointer has to be moved. To correctly point in
the beginning of the IPv6 header the dispatch byte has to be pulled off
before packet can be processed by netif_rx_in().

Test scenario: IPv6 packets are not correctly interpreted by the network
layer when IPv6 header is not compressed (e.g. ICMPv6 Echo Reply is not
propagated correctly to the ICMPv6 layer because the extra byte will make
the header look corrupted).

Similar approach is done for IEEE 802.15.4.

Signed-off-by: Lukasz Duda <lukasz.duda@nordicsemi.no>
Signed-off-by: Glenn Ruben Bakke <glenn.ruben.bakke@nordicsemi.no>
---
 net/bluetooth/6lowpan.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
index d040365..350f379 100644
--- a/net/bluetooth/6lowpan.c
+++ b/net/bluetooth/6lowpan.c
@@ -307,6 +307,9 @@ static int recv_pkt(struct sk_buff *skb, struct net_device *dev,
 
 	/* check that it's our buffer */
 	if (lowpan_is_ipv6(*skb_network_header(skb))) {
+		/* Pull off the 1-byte of 6lowpan header. */
+		skb_pull(skb, 1);
+
 		/* Copy the packet so that the IPv6 header is
 		 * properly aligned.
 		 */
-- 
2.5.0

Re: [PATCH] Bluetooth: 6lowpan: Fix handling of uncompressed IPv6 packets

[Jukka Rissanen]

Hi,

good catch.

Acked-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>


On Wed, 2016-01-13 at 16:57 +0100, Lukasz Duda wrote:
> This patch fixes incorrect handling of the 6lowpan packets that
> contain
> uncompressed IPv6 header.
> 
> RFC4944 specifies a special dispatch for 6lowpan to carry
> uncompressed
> IPv6 header. This dispatch (1 byte long) has to be removed during
> reception and skb data pointer has to be moved. To correctly point in
> the beginning of the IPv6 header the dispatch byte has to be pulled
> off
> before packet can be processed by netif_rx_in().
> 
> Test scenario: IPv6 packets are not correctly interpreted by the
> network
> layer when IPv6 header is not compressed (e.g. ICMPv6 Echo Reply is
> not
> propagated correctly to the ICMPv6 layer because the extra byte will
> make
> the header look corrupted).
> 
> Similar approach is done for IEEE 802.15.4.
> 
> Signed-off-by: Lukasz Duda <lukasz.duda@nordicsemi.no>
> Signed-off-by: Glenn Ruben Bakke <glenn.ruben.bakke@nordicsemi.no>
> ---
>  net/bluetooth/6lowpan.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/net/bluetooth/6lowpan.c b/net/bluetooth/6lowpan.c
> index d040365..350f379 100644
> --- a/net/bluetooth/6lowpan.c
> +++ b/net/bluetooth/6lowpan.c
> @@ -307,6 +307,9 @@ static int recv_pkt(struct sk_buff *skb, struct
> net_device *dev,
>  
>  	/* check that it's our buffer */
>  	if (lowpan_is_ipv6(*skb_network_header(skb))) {
> +		/* Pull off the 1-byte of 6lowpan header. */
> +		skb_pull(skb, 1);
> +
>  		/* Copy the packet so that the IPv6 header is
>  		 * properly aligned.
>  		 */


Cheers,
Jukka

Re: [PATCH] Bluetooth: 6lowpan: Fix handling of uncompressed IPv6 packets

[Johan Hedberg]

Hi Lukasz,

On Wed, Jan 13, 2016, Lukasz Duda wrote:
> This patch fixes incorrect handling of the 6lowpan packets that contain
> uncompressed IPv6 header.
> 
> RFC4944 specifies a special dispatch for 6lowpan to carry uncompressed
> IPv6 header. This dispatch (1 byte long) has to be removed during
> reception and skb data pointer has to be moved. To correctly point in
> the beginning of the IPv6 header the dispatch byte has to be pulled off
> before packet can be processed by netif_rx_in().
> 
> Test scenario: IPv6 packets are not correctly interpreted by the network
> layer when IPv6 header is not compressed (e.g. ICMPv6 Echo Reply is not
> propagated correctly to the ICMPv6 layer because the extra byte will make
> the header look corrupted).
> 
> Similar approach is done for IEEE 802.15.4.
> 
> Signed-off-by: Lukasz Duda <lukasz.duda@nordicsemi.no>
> Signed-off-by: Glenn Ruben Bakke <glenn.ruben.bakke@nordicsemi.no>
> ---
>  net/bluetooth/6lowpan.c | 3 +++
>  1 file changed, 3 insertions(+)

Applied to bluetooth.git. Thanks.

Johan