Re: [PATCH net-next 0/7] Allow to monitor multicast cache event via rtnetlink

On 12/07/12 at 10:38am, David Laight wrote:

What are you going to align the data with respect to?
I doubt you can assume that the start of the netlink
message itself is 8 byte aligned - so any attempt
to 8 byte align an item is probably doomed to failure.

Correct me if I'm wrong but skb->head will be aligned to
SKB_DATA_ALIGN() which as I understand is guaranted to
be 8 bytse aligned. So we can just add needed padding if
skb->data would not be aligned correctly after the next
netlink attribute header was added.

All user space needs to do is use a receive buffer that
is 8 byte aligned as well and we are good to go.