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authorDavid S. Miller <davem@davemloft.net>2019-03-01 17:03:00 -0800
committerDavid S. Miller <davem@davemloft.net>2019-03-01 17:03:00 -0800
commit9bfc445e0eece65b51305c47d7c84d8f34c2f7c1 (patch)
tree4b3a92fde9a824d948a57061495a39e4df87f670 /Documentation
parenteeaadd8285bf51722817807a720a2d150d1d6fc9 (diff)
parent8a42eda2582ada073d7320ca703fb5fa49600e87 (diff)
Merge branch 'doc-net-ieee802154-move-from-plain-text-to-rst'
Stefan Schmidt says: ==================== doc: net: ieee802154: move from plain text to rst The ieee802154 subsystem doc was still in plain text. With the networking book taking shape I thought it was time to do the first step and move it over to rst. This really is only the minimal conversion. I need to take some time to update and extend the docs. The patches are based on net-next, but they only touch the networking book so I would not expect and trouble. From what I have seen they would go through Jonathan's tree after being acked by Dave? If you want this patches against a different tree let me know. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/networking/ieee802154.rst (renamed from Documentation/networking/ieee802154.txt)193
-rw-r--r--Documentation/networking/index.rst1
2 files changed, 99 insertions, 95 deletions
diff --git a/Documentation/networking/ieee802154.txt b/Documentation/networking/ieee802154.rst
index e74d8e1da0e2..36ca823a1122 100644
--- a/Documentation/networking/ieee802154.txt
+++ b/Documentation/networking/ieee802154.rst
@@ -1,54 +1,79 @@
-
- Linux IEEE 802.15.4 implementation
-
+===============================
+IEEE 802.15.4 Developer's Guide
+===============================
Introduction
============
The IEEE 802.15.4 working group focuses on standardization of the bottom
two layers: Medium Access Control (MAC) and Physical access (PHY). And there
are mainly two options available for upper layers:
- - ZigBee - proprietary protocol from the ZigBee Alliance
- - 6LoWPAN - IPv6 networking over low rate personal area networks
+
+- ZigBee - proprietary protocol from the ZigBee Alliance
+- 6LoWPAN - IPv6 networking over low rate personal area networks
The goal of the Linux-wpan is to provide a complete implementation
of the IEEE 802.15.4 and 6LoWPAN protocols. IEEE 802.15.4 is a stack
of protocols for organizing Low-Rate Wireless Personal Area Networks.
The stack is composed of three main parts:
- - IEEE 802.15.4 layer; We have chosen to use plain Berkeley socket API,
- the generic Linux networking stack to transfer IEEE 802.15.4 data
- messages and a special protocol over netlink for configuration/management
- - MAC - provides access to shared channel and reliable data delivery
- - PHY - represents device drivers
+- IEEE 802.15.4 layer; We have chosen to use plain Berkeley socket API,
+ the generic Linux networking stack to transfer IEEE 802.15.4 data
+ messages and a special protocol over netlink for configuration/management
+- MAC - provides access to shared channel and reliable data delivery
+- PHY - represents device drivers
Socket API
==========
-int sd = socket(PF_IEEE802154, SOCK_DGRAM, 0);
-.....
+.. c:function:: 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 the userspace package (see either http://wpan.cakelab.org/ or the
git tree at https://github.com/linux-wpan/wpan-tools).
+6LoWPAN Linux implementation
+============================
+
+The IEEE 802.15.4 standard specifies an MTU of 127 bytes, yielding about 80
+octets of actual MAC payload once security is turned on, on a wireless link
+with a link throughput of 250 kbps or less. The 6LoWPAN adaptation format
+[RFC4944] was specified to carry IPv6 datagrams over such constrained links,
+taking into account limited bandwidth, memory, or energy resources that are
+expected in applications such as wireless Sensor Networks. [RFC4944] defines
+a Mesh Addressing header to support sub-IP forwarding, a Fragmentation header
+to support the IPv6 minimum MTU requirement [RFC2460], and stateless header
+compression for IPv6 datagrams (LOWPAN_HC1 and LOWPAN_HC2) to reduce the
+relatively large IPv6 and UDP headers down to (in the best case) several bytes.
+
+In September 2011 the standard update was published - [RFC6282].
+It deprecates HC1 and HC2 compression and defines IPHC encoding format which is
+used in this Linux implementation.
+
+All the code related to 6lowpan you may find in files: net/6lowpan/*
+and net/ieee802154/6lowpan/*
+
+To setup a 6LoWPAN interface you need:
+1. Add IEEE802.15.4 interface and set channel and PAN ID;
+2. Add 6lowpan interface by command like:
+# ip link add link wpan0 name lowpan0 type lowpan
+3. Bring up 'lowpan0' interface
-Kernel side
-=============
+Drivers
+=======
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 a management (e.g. MLME) and data API.
+exports a management (e.g. 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.
+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
@@ -64,9 +89,8 @@ net_device with a pointer to struct ieee802154_mlme_ops instance. The fields
assoc_req, assoc_resp, disassoc_req, start_req, and scan_req are optional.
All other fields are required.
-
SoftMAC
-=======
+-------
The MAC is the middle layer in the IEEE 802.15.4 Linux stack. This moment it
provides interface for drivers registration and management of slave interfaces.
@@ -79,99 +103,78 @@ This layer is going to be extended soon.
See header include/net/mac802154.h and several drivers in
drivers/net/ieee802154/.
+Fake drivers
+------------
+
+In addition there is a driver available which simulates a real device with
+SoftMAC (fakelb - IEEE 802.15.4 loopback driver) interface. This option
+provides a possibility to test and debug the stack without usage of real hardware.
Device drivers API
==================
The include/net/mac802154.h defines following functions:
- - struct ieee802154_hw *
- ieee802154_alloc_hw(size_t priv_data_len, const struct ieee802154_ops *ops):
- allocation of IEEE 802.15.4 compatible hardware device
- - void ieee802154_free_hw(struct ieee802154_hw *hw):
- freeing allocated hardware device
+.. c:function:: struct ieee802154_dev *ieee802154_alloc_device (size_t priv_size, struct ieee802154_ops *ops)
- - int ieee802154_register_hw(struct ieee802154_hw *hw):
- register PHY which is the allocated hardware device, in the system
+Allocation of IEEE 802.15.4 compatible device.
- - void ieee802154_unregister_hw(struct ieee802154_hw *hw):
- freeing registered PHY
+.. c:function:: void ieee802154_free_device(struct ieee802154_dev *dev)
- - void ieee802154_rx_irqsafe(struct ieee802154_hw *hw, struct sk_buff *skb,
- u8 lqi):
- telling 802.15.4 module there is a new received frame in the skb with
- the RF Link Quality Indicator (LQI) from the hardware device
+Freeing allocated device.
- - void ieee802154_xmit_complete(struct ieee802154_hw *hw, struct sk_buff *skb,
- bool ifs_handling):
- telling 802.15.4 module the frame in the skb is or going to be
- transmitted through the hardware device
+.. c:function:: int ieee802154_register_device(struct ieee802154_dev *dev)
+
+Register PHY in the system.
+
+.. c:function:: void ieee802154_unregister_device(struct ieee802154_dev *dev)
+
+Freeing registered PHY.
+
+.. c:function:: void ieee802154_rx_irqsafe(struct ieee802154_hw *hw, struct sk_buff *skb, u8 lqi):
+
+Telling 802.15.4 module there is a new received frame in the skb with
+the RF Link Quality Indicator (LQI) from the hardware device.
+
+.. c:function:: void ieee802154_xmit_complete(struct ieee802154_hw *hw, struct sk_buff *skb, bool ifs_handling):
+
+Telling 802.15.4 module the frame in the skb is or going to be
+transmitted through the hardware device
The device driver must implement the following callbacks in the IEEE 802.15.4
-operations structure at least:
-struct ieee802154_ops {
- ...
- int (*start)(struct ieee802154_hw *hw);
- void (*stop)(struct ieee802154_hw *hw);
- ...
- int (*xmit_async)(struct ieee802154_hw *hw, struct sk_buff *skb);
- int (*ed)(struct ieee802154_hw *hw, u8 *level);
- int (*set_channel)(struct ieee802154_hw *hw, u8 page, u8 channel);
- ...
-};
-
- - int start(struct ieee802154_hw *hw):
- handler that 802.15.4 module calls for the hardware device initialization.
-
- - void stop(struct ieee802154_hw *hw):
- handler that 802.15.4 module calls for the hardware device cleanup.
-
- - int xmit_async(struct ieee802154_hw *hw, struct sk_buff *skb):
- handler that 802.15.4 module calls for each frame in the skb going to be
- transmitted through the hardware device.
-
- - int ed(struct ieee802154_hw *hw, u8 *level):
- handler that 802.15.4 module calls for Energy Detection from the hardware
- device.
-
- - int set_channel(struct ieee802154_hw *hw, u8 page, u8 channel):
- set radio for listening on specific channel of the hardware device.
+operations structure at least::
-Moreover IEEE 802.15.4 device operations structure should be filled.
+ struct ieee802154_ops {
+ ...
+ int (*start)(struct ieee802154_hw *hw);
+ void (*stop)(struct ieee802154_hw *hw);
+ ...
+ int (*xmit_async)(struct ieee802154_hw *hw, struct sk_buff *skb);
+ int (*ed)(struct ieee802154_hw *hw, u8 *level);
+ int (*set_channel)(struct ieee802154_hw *hw, u8 page, u8 channel);
+ ...
+ };
-Fake drivers
-============
+.. c:function:: int start(struct ieee802154_hw *hw):
-In addition there is a driver available which simulates a real device with
-SoftMAC (fakelb - IEEE 802.15.4 loopback driver) interface. This option
-provides a possibility to test and debug the stack without usage of real hardware.
+Handler that 802.15.4 module calls for the hardware device initialization.
-See sources in drivers/net/ieee802154 folder for more details.
+.. c:function:: void stop(struct ieee802154_hw *hw):
+Handler that 802.15.4 module calls for the hardware device cleanup.
-6LoWPAN Linux implementation
-============================
+.. c:function:: int xmit_async(struct ieee802154_hw *hw, struct sk_buff *skb):
-The IEEE 802.15.4 standard specifies an MTU of 127 bytes, yielding about 80
-octets of actual MAC payload once security is turned on, on a wireless link
-with a link throughput of 250 kbps or less. The 6LoWPAN adaptation format
-[RFC4944] was specified to carry IPv6 datagrams over such constrained links,
-taking into account limited bandwidth, memory, or energy resources that are
-expected in applications such as wireless Sensor Networks. [RFC4944] defines
-a Mesh Addressing header to support sub-IP forwarding, a Fragmentation header
-to support the IPv6 minimum MTU requirement [RFC2460], and stateless header
-compression for IPv6 datagrams (LOWPAN_HC1 and LOWPAN_HC2) to reduce the
-relatively large IPv6 and UDP headers down to (in the best case) several bytes.
+Handler that 802.15.4 module calls for each frame in the skb going to be
+transmitted through the hardware device.
-In September 2011 the standard update was published - [RFC6282].
-It deprecates HC1 and HC2 compression and defines IPHC encoding format which is
-used in this Linux implementation.
+.. c:function:: int ed(struct ieee802154_hw *hw, u8 *level):
-All the code related to 6lowpan you may find in files: net/6lowpan/*
-and net/ieee802154/6lowpan/*
+Handler that 802.15.4 module calls for Energy Detection from the hardware
+device.
-To setup a 6LoWPAN interface you need:
-1. Add IEEE802.15.4 interface and set channel and PAN ID;
-2. Add 6lowpan interface by command like:
- # ip link add link wpan0 name lowpan0 type lowpan
-3. Bring up 'lowpan0' interface
+.. c:function:: int set_channel(struct ieee802154_hw *hw, u8 page, u8 channel):
+
+Set radio for listening on specific channel of the hardware device.
+
+Moreover IEEE 802.15.4 device operations structure should be filled.
diff --git a/Documentation/networking/index.rst b/Documentation/networking/index.rst
index b08cf145d5eb..f0da1b001514 100644
--- a/Documentation/networking/index.rst
+++ b/Documentation/networking/index.rst
@@ -25,6 +25,7 @@ Contents:
device_drivers/intel/iavf
device_drivers/intel/ice
devlink-info-versions
+ ieee802154
kapi
z8530book
msg_zerocopy