Re: [RFCv3 bluetooth-next 2/6] ieee802154: add helpers for frame control checks

[Stefan Schmidt <stefan@osg.samsung.com>]

Hello.

On 04/08/15 20:47, Alexander Aring wrote:
> On Tue, Aug 04, 2015 at 08:35:33PM +0200, Stefan Schmidt wrote:
> ...
>>> right it doesn't manipulate the skb. For the "problems like we did with
>>> the 6lowpan" you need to decide which problems, I see several:
>>>
>>>   - running skb_pull (which removes) buffer and we don't have the room to
>>>     pull out the bytes of skb, example: skb->len = 3, skb_pull size is 4
>>>     which ends in a BUG(), we need to check it with skb_may_pull before.
>> Sorry, I should have been a bit more verbose here to make it clearer. I
>> meant the above.
>>
> This doesn't happend here. It's just dereferencing frame control field
> which should be always at beginning of skb_mac_header. We need the
> unaligned access, because we cannot assume that the address is at an
> aligned address.
>
> And the frame control field is in little endian byte order, we simple
> use the byte order which we also transmit (everywhere).

Thanks for explaining it again.

regards
Stefan Schmidt