Re: [PATCH 1/9] batman-adv: add UNICAST_4ADDR packet type

From: Antonio Quartulli <redacted>
Date: Sat,  3 Nov 2012 19:48:26 +0100

The current unicast packet type does not contain the orig source address. This
patches add a new unicast packet (called UNICAST_4ADDR) which provides two new
fields: the originator source address and the subtype (the type of the data
contained in the packet payload). The former is useful to identify the node
which injected the packet into the network and the latter is useful to avoid
creating new unicast packet types in the future: a macro defining a new subtype
will be enough.

Signed-off-by: Antonio Quartulli <redacted>

Your packet layouts are very poorly designed and I want you to stop
and think seriously about things before extending things further.

All of this __packed stuff is a serious problem.

It means that on RISC system, fields such as your 32-bit sequence
number, will be read and written using byte loads and stores.

This is terrible.

Instead, design the structures so that they are full filled out to
at least 4 byte boundaries, so that they and the contents after
them, are 4 byte aligned too.

Then you won't need to mark all of your packet header structs
with __packed, and therefore the compiler can use full 32-bit
loads and stores to access 32-bit fields.

I'm not applying this series, sorry, it just continues a major
problem that the batman-adv code already has.