aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-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 @@
1 1===============================
2 Linux IEEE 802.15.4 implementation 2IEEE 802.15.4 Developer's Guide
3 3===============================
4 4
5Introduction 5Introduction
6============ 6============
7The IEEE 802.15.4 working group focuses on standardization of the bottom 7The IEEE 802.15.4 working group focuses on standardization of the bottom
8two layers: Medium Access Control (MAC) and Physical access (PHY). And there 8two layers: Medium Access Control (MAC) and Physical access (PHY). And there
9are mainly two options available for upper layers: 9are mainly two options available for upper layers:
10 - ZigBee - proprietary protocol from the ZigBee Alliance 10
11 - 6LoWPAN - IPv6 networking over low rate personal area networks 11- ZigBee - proprietary protocol from the ZigBee Alliance
12- 6LoWPAN - IPv6 networking over low rate personal area networks
12 13
13The goal of the Linux-wpan is to provide a complete implementation 14The goal of the Linux-wpan is to provide a complete implementation
14of the IEEE 802.15.4 and 6LoWPAN protocols. IEEE 802.15.4 is a stack 15of the IEEE 802.15.4 and 6LoWPAN protocols. IEEE 802.15.4 is a stack
15of protocols for organizing Low-Rate Wireless Personal Area Networks. 16of protocols for organizing Low-Rate Wireless Personal Area Networks.
16 17
17The stack is composed of three main parts: 18The stack is composed of three main parts:
18 - IEEE 802.15.4 layer; We have chosen to use plain Berkeley socket API,
19 the generic Linux networking stack to transfer IEEE 802.15.4 data
20 messages and a special protocol over netlink for configuration/management
21 - MAC - provides access to shared channel and reliable data delivery
22 - PHY - represents device drivers
23 19
20- IEEE 802.15.4 layer; We have chosen to use plain Berkeley socket API,
21 the generic Linux networking stack to transfer IEEE 802.15.4 data
22 messages and a special protocol over netlink for configuration/management
23- MAC - provides access to shared channel and reliable data delivery
24- PHY - represents device drivers
24 25
25Socket API 26Socket API
26========== 27==========
27 28
28int sd = socket(PF_IEEE802154, SOCK_DGRAM, 0); 29.. c:function:: int sd = socket(PF_IEEE802154, SOCK_DGRAM, 0);
29.....
30 30
31The address family, socket addresses etc. are defined in the 31The address family, socket addresses etc. are defined in the
32include/net/af_ieee802154.h header or in the special header 32include/net/af_ieee802154.h header or in the special header
33in the userspace package (see either http://wpan.cakelab.org/ or the 33in the userspace package (see either http://wpan.cakelab.org/ or the
34git tree at https://github.com/linux-wpan/wpan-tools). 34git tree at https://github.com/linux-wpan/wpan-tools).
35 35
366LoWPAN Linux implementation
37============================
38
39The IEEE 802.15.4 standard specifies an MTU of 127 bytes, yielding about 80
40octets of actual MAC payload once security is turned on, on a wireless link
41with a link throughput of 250 kbps or less. The 6LoWPAN adaptation format
42[RFC4944] was specified to carry IPv6 datagrams over such constrained links,
43taking into account limited bandwidth, memory, or energy resources that are
44expected in applications such as wireless Sensor Networks. [RFC4944] defines
45a Mesh Addressing header to support sub-IP forwarding, a Fragmentation header
46to support the IPv6 minimum MTU requirement [RFC2460], and stateless header
47compression for IPv6 datagrams (LOWPAN_HC1 and LOWPAN_HC2) to reduce the
48relatively large IPv6 and UDP headers down to (in the best case) several bytes.
49
50In September 2011 the standard update was published - [RFC6282].
51It deprecates HC1 and HC2 compression and defines IPHC encoding format which is
52used in this Linux implementation.
53
54All the code related to 6lowpan you may find in files: net/6lowpan/*
55and net/ieee802154/6lowpan/*
56
57To setup a 6LoWPAN interface you need:
581. Add IEEE802.15.4 interface and set channel and PAN ID;
592. Add 6lowpan interface by command like:
60# ip link add link wpan0 name lowpan0 type lowpan
613. Bring up 'lowpan0' interface
36 62
37Kernel side 63Drivers
38============= 64=======
39 65
40Like with WiFi, there are several types of devices implementing IEEE 802.15.4. 66Like with WiFi, there are several types of devices implementing IEEE 802.15.4.
411) 'HardMAC'. The MAC layer is implemented in the device itself, the device 671) 'HardMAC'. The MAC layer is implemented in the device itself, the device
42 exports a management (e.g. MLME) and data API. 68exports a management (e.g. MLME) and data API.
432) 'SoftMAC' or just radio. These types of devices are just radio transceivers 692) 'SoftMAC' or just radio. These types of devices are just radio transceivers
44 possibly with some kinds of acceleration like automatic CRC computation and 70possibly with some kinds of acceleration like automatic CRC computation and
45 comparation, automagic ACK handling, address matching, etc. 71comparation, automagic ACK handling, address matching, etc.
46 72
47Those types of devices require different approach to be hooked into Linux kernel. 73Those types of devices require different approach to be hooked into Linux kernel.
48 74
49
50HardMAC 75HardMAC
51======= 76-------
52 77
53See the header include/net/ieee802154_netdev.h. You have to implement Linux 78See the header include/net/ieee802154_netdev.h. You have to implement Linux
54net_device, with .type = ARPHRD_IEEE802154. Data is exchanged with socket family 79net_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
64assoc_req, assoc_resp, disassoc_req, start_req, and scan_req are optional. 89assoc_req, assoc_resp, disassoc_req, start_req, and scan_req are optional.
65All other fields are required. 90All other fields are required.
66 91
67
68SoftMAC 92SoftMAC
69======= 93-------
70 94
71The MAC is the middle layer in the IEEE 802.15.4 Linux stack. This moment it 95The MAC is the middle layer in the IEEE 802.15.4 Linux stack. This moment it
72provides interface for drivers registration and management of slave interfaces. 96provides interface for drivers registration and management of slave interfaces.
@@ -79,99 +103,78 @@ This layer is going to be extended soon.
79See header include/net/mac802154.h and several drivers in 103See header include/net/mac802154.h and several drivers in
80drivers/net/ieee802154/. 104drivers/net/ieee802154/.
81 105
106Fake drivers
107------------
108
109In addition there is a driver available which simulates a real device with
110SoftMAC (fakelb - IEEE 802.15.4 loopback driver) interface. This option
111provides a possibility to test and debug the stack without usage of real hardware.
82 112
83Device drivers API 113Device drivers API
84================== 114==================
85 115
86The include/net/mac802154.h defines following functions: 116The include/net/mac802154.h defines following functions:
87 - struct ieee802154_hw *
88 ieee802154_alloc_hw(size_t priv_data_len, const struct ieee802154_ops *ops):
89 allocation of IEEE 802.15.4 compatible hardware device
90 117
91 - void ieee802154_free_hw(struct ieee802154_hw *hw): 118.. c:function:: struct ieee802154_dev *ieee802154_alloc_device (size_t priv_size, struct ieee802154_ops *ops)
92 freeing allocated hardware device
93 119
94 - int ieee802154_register_hw(struct ieee802154_hw *hw): 120Allocation of IEEE 802.15.4 compatible device.
95 register PHY which is the allocated hardware device, in the system
96 121
97 - void ieee802154_unregister_hw(struct ieee802154_hw *hw): 122.. c:function:: void ieee802154_free_device(struct ieee802154_dev *dev)
98 freeing registered PHY
99 123
100 - void ieee802154_rx_irqsafe(struct ieee802154_hw *hw, struct sk_buff *skb, 124Freeing allocated device.
101 u8 lqi):
102 telling 802.15.4 module there is a new received frame in the skb with
103 the RF Link Quality Indicator (LQI) from the hardware device
104 125
105 - void ieee802154_xmit_complete(struct ieee802154_hw *hw, struct sk_buff *skb, 126.. c:function:: int ieee802154_register_device(struct ieee802154_dev *dev)
106 bool ifs_handling): 127
107 telling 802.15.4 module the frame in the skb is or going to be 128Register PHY in the system.
108 transmitted through the hardware device 129
130.. c:function:: void ieee802154_unregister_device(struct ieee802154_dev *dev)
131
132Freeing registered PHY.
133
134.. c:function:: void ieee802154_rx_irqsafe(struct ieee802154_hw *hw, struct sk_buff *skb, u8 lqi):
135
136Telling 802.15.4 module there is a new received frame in the skb with
137the RF Link Quality Indicator (LQI) from the hardware device.
138
139.. c:function:: void ieee802154_xmit_complete(struct ieee802154_hw *hw, struct sk_buff *skb, bool ifs_handling):
140
141Telling 802.15.4 module the frame in the skb is or going to be
142transmitted through the hardware device
109 143
110The device driver must implement the following callbacks in the IEEE 802.15.4 144The device driver must implement the following callbacks in the IEEE 802.15.4
111operations structure at least: 145operations structure at least::
112struct ieee802154_ops {
113 ...
114 int (*start)(struct ieee802154_hw *hw);
115 void (*stop)(struct ieee802154_hw *hw);
116 ...
117 int (*xmit_async)(struct ieee802154_hw *hw, struct sk_buff *skb);
118 int (*ed)(struct ieee802154_hw *hw, u8 *level);
119 int (*set_channel)(struct ieee802154_hw *hw, u8 page, u8 channel);
120 ...
121};
122
123 - int start(struct ieee802154_hw *hw):
124 handler that 802.15.4 module calls for the hardware device initialization.
125
126 - void stop(struct ieee802154_hw *hw):
127 handler that 802.15.4 module calls for the hardware device cleanup.
128
129 - int xmit_async(struct ieee802154_hw *hw, struct sk_buff *skb):
130 handler that 802.15.4 module calls for each frame in the skb going to be
131 transmitted through the hardware device.
132
133 - int ed(struct ieee802154_hw *hw, u8 *level):
134 handler that 802.15.4 module calls for Energy Detection from the hardware
135 device.
136
137 - int set_channel(struct ieee802154_hw *hw, u8 page, u8 channel):
138 set radio for listening on specific channel of the hardware device.
139 146
140Moreover IEEE 802.15.4 device operations structure should be filled. 147 struct ieee802154_ops {
148 ...
149 int (*start)(struct ieee802154_hw *hw);
150 void (*stop)(struct ieee802154_hw *hw);
151 ...
152 int (*xmit_async)(struct ieee802154_hw *hw, struct sk_buff *skb);
153 int (*ed)(struct ieee802154_hw *hw, u8 *level);
154 int (*set_channel)(struct ieee802154_hw *hw, u8 page, u8 channel);
155 ...
156 };
141 157
142Fake drivers 158.. c:function:: int start(struct ieee802154_hw *hw):
143============
144 159
145In addition there is a driver available which simulates a real device with 160Handler that 802.15.4 module calls for the hardware device initialization.
146SoftMAC (fakelb - IEEE 802.15.4 loopback driver) interface. This option
147provides a possibility to test and debug the stack without usage of real hardware.
148 161
149See sources in drivers/net/ieee802154 folder for more details. 162.. c:function:: void stop(struct ieee802154_hw *hw):
150 163
164Handler that 802.15.4 module calls for the hardware device cleanup.
151 165
1526LoWPAN Linux implementation 166.. c:function:: int xmit_async(struct ieee802154_hw *hw, struct sk_buff *skb):
153============================
154 167
155The IEEE 802.15.4 standard specifies an MTU of 127 bytes, yielding about 80 168Handler that 802.15.4 module calls for each frame in the skb going to be
156octets of actual MAC payload once security is turned on, on a wireless link 169transmitted through the hardware device.
157with a link throughput of 250 kbps or less. The 6LoWPAN adaptation format
158[RFC4944] was specified to carry IPv6 datagrams over such constrained links,
159taking into account limited bandwidth, memory, or energy resources that are
160expected in applications such as wireless Sensor Networks. [RFC4944] defines
161a Mesh Addressing header to support sub-IP forwarding, a Fragmentation header
162to support the IPv6 minimum MTU requirement [RFC2460], and stateless header
163compression for IPv6 datagrams (LOWPAN_HC1 and LOWPAN_HC2) to reduce the
164relatively large IPv6 and UDP headers down to (in the best case) several bytes.
165 170
166In September 2011 the standard update was published - [RFC6282]. 171.. c:function:: int ed(struct ieee802154_hw *hw, u8 *level):
167It deprecates HC1 and HC2 compression and defines IPHC encoding format which is
168used in this Linux implementation.
169 172
170All the code related to 6lowpan you may find in files: net/6lowpan/* 173Handler that 802.15.4 module calls for Energy Detection from the hardware
171and net/ieee802154/6lowpan/* 174device.
172 175
173To setup a 6LoWPAN interface you need: 176.. c:function:: int set_channel(struct ieee802154_hw *hw, u8 page, u8 channel):
1741. Add IEEE802.15.4 interface and set channel and PAN ID; 177
1752. Add 6lowpan interface by command like: 178Set radio for listening on specific channel of the hardware device.
176 # ip link add link wpan0 name lowpan0 type lowpan 179
1773. Bring up 'lowpan0' interface 180Moreover 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:
25 device_drivers/intel/iavf 25 device_drivers/intel/iavf
26 device_drivers/intel/ice 26 device_drivers/intel/ice
27 devlink-info-versions 27 devlink-info-versions
28 ieee802154
28 kapi 29 kapi
29 z8530book 30 z8530book
30 msg_zerocopy 31 msg_zerocopy