wpantund
is a user-space network interface driver/daemon that
provides a native IPv6 network interface to a low-power wireless
Network Co-Processor (or NCP). It was written and developed by
Nest Labs to make supporting Thread
connectivity on unix-like operating systems more straightforward.
wpantund
is designed to marshall all access to the NCP, ensuring
that it always remains in a consistent, well-defined state.
This is not an official Google product.
wpantund
provides:
- ...a native IPv6 interface to an NCP.
- ...a command line interface (
wpanctl
) for managing and configuring the NCP. - ...a DBus API for managing and configuring the NCP.
- ...a way to reliably manage the power state of the NCP.
- ...a uniform mechanism for handling NCP firmware updates.
The architecture and design of wpantund
has been motivated by the
following design goals (in no particular order):
- Portability across unix-like operating systems (Currently supports Linux and OS X. BSD support should be fairly trivial to add)
- Require few runtime dependencies (DBus, with boost needed when building)
- Single-threaded architecture, with heavy use of asynchronous I/O
- Power efficiency (0% CPU usage when idle)
- Allow management interface to be used by multiple independent applications simultaneously.
- Allow multiple instances of
wpantund
to gracefully co-exist on a single machine. - Modular, plugin-based architecture (All details for communicating with a specific NCP stack are implemented as plugins)
Currently, the following NCP plugins are included:
src/ncp-spinel
: Supports NCPs that communicate using the Spinel NCP Protocol, used by NCPs running OpenThread.src/ncp-dummy
: A dummy NCP plug-in implementation meant to be the starting point for implementing new NCP plug-ins.
wpantund
is open-source software, released under the Apache License,
Version 2.0. See the file LICENSE
for more information.
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
wpantund
is conceptually similar in purpose to the point-to-point
daemon (pppd
, commonly used on unix platforms to provide network
connectivity via a dial-up modems)---except that instead of
communicating with a dial-up modem, wpantund
is communicating with
an NCP.
wpantund
communicates with the NCP via an abstraction of a
asynchronous stream socket, which could be any of the following:
- A real serial port (UART) connected to the NCP (preferably with hardware flow control)
- The stdin and stdout from a subprocess (For supporting SPI interfaces using a translator program, or debugging virtual stacks)
- A TCP socket (For debugging, not recommended for production)
Unlike a dial-up modem, NCPs often have a rich management interface
for performing operations like forming a network, joining a network,
scanning for nearby networks, etc. To perform these operations,
wpantund
includes a command line utility called wpanctl
.
Applications that need to directly configure the network interface can
also communicate directly with wpantund
using its DBus API.
To expose a native IPv6 network interface to the host operating
system, wpantund
uses the tun
driver on Linux and the utun
driver on OS X. On Linux, the default name for this interface is
wpan0
. On OS X, the default name is utun0
.
The behavior of wpantund
is determined by its configuration
parameters, which may be specified in a configuration file (typically
/etc/wpantund.conf
) or at the command line. A typical configuration
file might look like this: (For a more thorough explanation of
available configuration parameters, see the included example).
# Try to name the network interface `wpan0`.
# If not possible, a different name will be used.
Config:TUN:InterfaceName "wpan0"
# The pathname of the socket used to communicate
# with the NCP.
Config:NCP:SocketPath "/dev/ttyUSB0"
# The name of the driver plugin to use. The chosen
# plugin must support the NCP you are trying to use.
Config:NCP:DriverName "spinel"
# Drop root privileges after opening all sockets
Config:Daemon:PrivDropToUser "nobody"
# Use a CCA Threshold of -70db
NCP:CCAThreshold "-70"
When up and running, wpanctl
can be used to check the status of the
interface and perform various management operations. For example, to
check the general status of an interface:
$ sudo wpanctl status
wpan0 => [
"NCP:State" => "offline"
"Daemon:Enabled" => true
"NCP:Version" => "OPENTHREAD/g1651a47; May 23 2016 17:23:24"
"Daemon:Version" => "0.07.00 (May 23 2016 12:58:54)"
"Config:NCP:DriverName" => "spinel"
"NCP:HardwareAddress" => [F1D92A82C8D8FE43]
]
Here we see that the NCP is in the offline
state, along with a few
additional bits of information like the version of the NCP and it's
hardware address. From here we can easily form a new network:
$ sudo wpanctl form "wpantund-testnet"
Forming WPAN "wpantund-testnet" as node type router
Successfully formed!
$
And now if we check the status, we will see a lot more information:
$ sudo wpanctl status
wpan0 => [
"NCP:State" => "associated"
"Daemon:Enabled" => true
"NCP:Version" => "OPENTHREAD/g1651a47; May 23 2016 17:23:24"
"Daemon:Version" => "0.07.00 (May 23 2016 12:58:54)"
"Config:NCP:DriverName" => "spinel"
"NCP:HardwareAddress" => [F1D92A82C8D8FE43]
"NCP:Channel" => 23
"Network:NodeType" => "leader"
"Network:Name" => "wpantund-testnet"
"Network:XPANID" => 0x09717AEF221F66FB
"Network:PANID" => 0xBFCD
"IPv6:LinkLocalAddress" => "fe80::f3d9:2a82:c8d8:fe43"
"IPv6:MeshLocalAddress" => "fd09:717a:ef22::9a5d:5d1e:5527:5fc8"
"IPv6:MeshLocalPrefix" => "fd09:717a:ef22::/64"
]
$ ifconfig wpan0
wpan0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1280
inet6 fe80::f3d9:2a82:c8d8:fe43%wpan0 prefixlen 10 scopeid 0x15
inet6 fd09:717a:ef22::9a5d:5d1e:5527:5fc8 prefixlen 64
If compiled with libreadline
or libedit
, wpanctl
supports an
interactive console, which is very convenient. All commands support
online help: simply type help
to get a list of supported commands,
or add -h
to a command to get help with that specific command.
See the wiki for more information: https://github.com/openthread/wpantund/wiki
Submit bugs and feature requests to issue tracker. We use the following mailing lists for discussion and announcements:
- wpantund-announce
- Official Anouncements About
wpantund
- wpantund-users
-
wpantund
User Discussion Group - wpantund-devel
-
wpantund
Developer Discussion Group
The following people have significantly contributed to the design
and development of wpantund
:
- Robert Quattlebaum
- Marcin Szczodrak
- Vaas Krishnamurthy
- Arjuna Siva
- Abtin Keshavarzian
If you would like to contribute to this project, please read CONTRIBUTING.md first.