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Based on kernel version 3.2. Page generated on 2012-01-05 23:29 EST.

1	
2			Linux IEEE 802.15.4 implementation
3	
4	
5	Introduction
6	============
7	
8	The Linux-ZigBee project goal is to provide complete implementation
9	of IEEE 802.15.4 / ZigBee / 6LoWPAN protocols. IEEE 802.15.4 is a stack
10	of protocols for organizing Low-Rate Wireless Personal Area Networks.
11	
12	Currently only IEEE 802.15.4 layer is implemented. We have chosen
13	to use plain Berkeley socket API, the generic Linux networking stack
14	to transfer IEEE 802.15.4 messages and a special protocol over genetlink
15	for configuration/management
16	
17	
18	Socket API
19	==========
20	
21	int sd = socket(PF_IEEE802154, SOCK_DGRAM, 0);
22	.....
23	
24	The address family, socket addresses etc. are defined in the
25	include/net/af_ieee802154.h header or in the special header
26	in our userspace package (see either linux-zigbee sourceforge download page
27	or git tree at git://linux-zigbee.git.sourceforge.net/gitroot/linux-zigbee).
28	
29	One can use SOCK_RAW for passing raw data towards device xmit function. YMMV.
30	
31	
32	MLME - MAC Level Management
33	============================
34	
35	Most of IEEE 802.15.4 MLME interfaces are directly mapped on netlink commands.
36	See the include/net/nl802154.h header. Our userspace tools package
37	(see above) provides CLI configuration utility for radio interfaces and simple
38	coordinator for IEEE 802.15.4 networks as an example users of MLME protocol.
39	
40	
41	Kernel side
42	=============
43	
44	Like with WiFi, there are several types of devices implementing IEEE 802.15.4.
45	1) 'HardMAC'. The MAC layer is implemented in the device itself, the device
46	   exports MLME and data API.
47	2) 'SoftMAC' or just radio. These types of devices are just radio transceivers
48	   possibly with some kinds of acceleration like automatic CRC computation and
49	   comparation, automagic ACK handling, address matching, etc.
50	
51	Those types of devices require different approach to be hooked into Linux kernel.
52	
53	
54	HardMAC
55	=======
56	
57	See the header include/net/ieee802154_netdev.h. You have to implement Linux
58	net_device, with .type = ARPHRD_IEEE802154. Data is exchanged with socket family
59	code via plain sk_buffs. On skb reception skb->cb must contain additional
60	info as described in the struct ieee802154_mac_cb. During packet transmission
61	the skb->cb is used to provide additional data to device's header_ops->create
62	function. Be aware, that this data can be overriden later (when socket code
63	submits skb to qdisc), so if you need something from that cb later, you should
64	store info in the skb->data on your own.
65	
66	To hook the MLME interface you have to populate the ml_priv field of your
67	net_device with a pointer to struct ieee802154_mlme_ops instance. All fields are
68	required.
69	
70	We provide an example of simple HardMAC driver at drivers/ieee802154/fakehard.c
71	
72	
73	SoftMAC
74	=======
75	
76	We are going to provide intermediate layer implementing IEEE 802.15.4 MAC
77	in software. This is currently WIP.
78	
79	See header include/net/mac802154.h and several drivers in drivers/ieee802154/.
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