sk_buff structure

[rahul b jain cs student]

Hi,

I am trying to modify the kernel networking code and have a question
regarding the sk_buff structure which is used to store the details of a
packet.
In this structure there are pointers called headroom, data, tailroom and
end. Does anyone know what these are used for. Or can anyone point me to a
good explanation for these fields.

I wanted to know how exactly they are populated ? Whether the headroom
contains the different headers ? What does the tailroom contain ?

Thanks,
Rahul.