ieee802154: add documentation about our stack

		Linux IEEE 802.15.4 implementation

Introduction

============

The Linux-ZigBee project goal is to provide complete implementation

of IEEE 802.15.4 / ZigBee / 6LoWPAN protocols. IEEE 802.15.4 is a stack

of protocols for organizing Low-Rate Wireless Personal Area Networks.

Currently only IEEE 802.15.4 layer is implemented. We have choosen

to use plain Berkeley socket API, the generic Linux networking stack

to transfer IEEE 802.15.4 messages and a special protocol over genetlink

for configuration/management

Socket API

==========

int sd = socket(PF_IEEE802154, SOCK_DGRAM, 0);

.....

The address family, socket addresses etc. are defined in the

include/net/ieee802154/af_ieee802154.h header or in the special header

in our userspace package (see either linux-zigbee sourceforge download page

or git tree at git://linux-zigbee.git.sourceforge.net/gitroot/linux-zigbee).

One can use SOCK_RAW for passing raw data towards device xmit function. YMMV.

MLME - MAC Level Management

============================

Most of IEEE 802.15.4 MLME interfaces are directly mapped on netlink commands.

See the include/net/ieee802154/nl802154.h header. Our userspace tools package

(see above) provides CLI configuration utility for radio interfaces and simple

coordinator for IEEE 802.15.4 networks as an example users of MLME protocol.

Kernel side

=============

Like with WiFi, there are several types of devices implementing IEEE 802.15.4.

1) 'HardMAC'. The MAC layer is implemented in the device itself, the device

   exports MLME and data API.

2) 'SoftMAC' or just radio. These types of devices are just radio transceivers

   possibly with some kinds of acceleration like automatic CRC computation and

   comparation, automagic ACK handling, address matching, etc.

Those types of devices require different approach to be hooked into Linux kernel.

HardMAC

=======

See the header include/net/ieee802154/netdevice.h. You have to implement Linux

net_device, with .type = ARPHRD_IEEE802154. Data is exchanged with socket family

code via plain sk_buffs. The control block of sk_buffs will contain additional

info as described in the struct ieee802154_mac_cb.

To hook the MLME interface you have to populate the ml_priv field of your

net_device with a pointer to struct ieee802154_mlme_ops instance. All fields are

required.

We provide an example of simple HardMAC driver at drivers/ieee802154/fakehard.c

SoftMAC

=======

We are going to provide intermediate layer impelementing IEEE 802.15.4 MAC

in software. This is currently WIP.

See header include/net/ieee802154/mac802154.h and several drivers in

drivers/ieee802154/

S:	Maintained

F:	drivers/ieee1394/raw1394*

IEEE 802.15.4 SUBSYSTEM

P:	Dmitry Eremin-Solenikov

M:	dbaryshkov@gmail.com

P:	Sergey Lapin

M:	slapin@ossfans.org

L:	linux-zigbee-devel@lists.sourceforge.net

W:	http://apps.sourceforge.net/trac/linux-zigbee

T:	git git://git.kernel.org/pub/scm/linux/kernel/git/lumag/lowpan.git

S:	Maintained

F:	net/ieee802154/

F:	drivers/ieee801254/

INTEGRITY MEASUREMENT ARCHITECTURE (IMA)

P:	Mimi Zohar

M:	zohar@us.ibm.com