projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 02cf2286 SL |
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 choosen | |
| 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/ieee802154/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/ieee802154/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/netdevice.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. The control block of sk_buffs will contain additional | |
| 60 | info as described in the struct ieee802154_mac_cb. | |
| 61 | ||
| 62 | To hook the MLME interface you have to populate the ml_priv field of your | |
| 63 | net_device with a pointer to struct ieee802154_mlme_ops instance. All fields are | |
| 64 | required. | |
| 65 | ||
| 66 | We provide an example of simple HardMAC driver at drivers/ieee802154/fakehard.c | |
| 67 | ||
| 68 | ||
| 69 | SoftMAC | |
| 70 | ======= | |
| 71 | ||
| 72 | We are going to provide intermediate layer impelementing IEEE 802.15.4 MAC | |
| 73 | in software. This is currently WIP. | |
| 74 | ||
| 75 | See header include/net/ieee802154/mac802154.h and several drivers in | |
| 76 | drivers/ieee802154/ |