From 849369d6c66d3054688672f97d31fceb8e8230fb Mon Sep 17 00:00:00 2001 From: root Date: Fri, 25 Dec 2015 04:40:36 +0000 Subject: initial_commit --- Documentation/networking/ieee802154.txt | 80 +++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+) create mode 100644 Documentation/networking/ieee802154.txt (limited to 'Documentation/networking/ieee802154.txt') diff --git a/Documentation/networking/ieee802154.txt b/Documentation/networking/ieee802154.txt new file mode 100644 index 00000000..f41ea240 --- /dev/null +++ b/Documentation/networking/ieee802154.txt @@ -0,0 +1,80 @@ + + 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 chosen +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/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/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_netdev.h. You have to implement Linux +net_device, with .type = ARPHRD_IEEE802154. Data is exchanged with socket family +code via plain sk_buffs. On skb reception skb->cb must contain additional +info as described in the struct ieee802154_mac_cb. During packet transmission +the skb->cb is used to provide additional data to device's header_ops->create +function. Be aware, that this data can be overriden later (when socket code +submits skb to qdisc), so if you need something from that cb later, you should +store info in the skb->data on your own. + +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 implementing IEEE 802.15.4 MAC +in software. This is currently WIP. + +See header include/net/mac802154.h and several drivers in drivers/ieee802154/. + -- cgit v1.2.3