Skip to content

Add protocol and transport documentation #663

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
Jan 22, 2024
Merged

Add protocol and transport documentation #663

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
f1d86c6
Add protocol and transport documentation
sdb9696 Jan 20, 2024
8dbeadf
Update post review
sdb9696 Jan 22, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
83 changes: 83 additions & 0 deletions docs/source/design.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,6 @@
.. py:module:: kasa.modules


.. _library_design:

Library Design & Modules
Expand Down Expand Up @@ -46,6 +47,7 @@ While the properties are designed to provide a nice API to use for common use ca
you may sometimes want to access the raw, cached data as returned by the device.
This can be done using the :attr:`~kasa.SmartDevice.internal_state` property.


.. _modules:

Modules
Expand All @@ -61,6 +63,42 @@ You can get the list of supported modules for a given device instance using :att
If you only need some module-specific information,
you can call the wanted method on the module to avoid using :meth:`~kasa.SmartDevice.update`.

Protocols and Transports
************************

The library supports two different TP-Link protocols, ``IOT`` and ``SMART``.
``IOT`` is the original Kasa protocol and ``SMART`` is the newer protocol supported by TAPO devices and newer KASA devices.
The original protocol has a ``target``, ``command``, ``args`` interface whereas the new protocol uses a different set of
commands and has a ``method``, ``parameters`` interface.
Confusingly TP-Link originally called the Kasa line "Kasa Smart" and hence this library used "Smart" in a lot of the
module and class names but actually they were built to work with the ``IOT`` protocol.

In 2021 TP-Link started updating the underlying communication transport used by Kasa devices to make them more secure.
It switched from a TCP connection with static XOR type of encryption to a transport called ``KLAP`` which communicates
over http and uses handshakes to negotiate a dynamic encryption cipher.
This automatic update was put on hold and only seemed to affect UK HS100 models.

In 2023 TP-Link started updating the underlying communication transport used by Tapo devices to make them more secure.
It switched from AES encryption via public key exchange to use ``KLAP`` encryption and negotiation due to concerns
around impersonation with AES.
The encryption cipher is the same as for Kasa KLAP but the handshake seeds are slightly different.
Also in 2023 TP-Link started releasing newer Kasa branded devices using the ``SMART`` protocol.
This appears to be driven by hardware version rather than firmware.


In order to support these different configurations the library migrated from a single :class:`TPLinkSmartHomeProtocol <kasa.protocol.TPLinkSmartHomeProtocol>`
to support pluggable transports and protocols.
The classes providing this functionality are:

- :class:`BaseProtocol <kasa.protocol.BaseProtocol>`
- :class:`IotProtocol <kasa.iotprotocol.IotProtocol>`
- :class:`SmartProtocol <kasa.smartprotocol.SmartProtocol>`

- :class:`BaseTransport <kasa.protocol.BaseTransport>`
- :class:`AesTransport <kasa.aestransport.AesTransport>`
- :class:`KlapTransport <kasa.klaptransport.KlapTransport>`
- :class:`KlapTransportV2 <kasa.klaptransport.KlapTransportV2>`


API documentation for modules
*****************************
Expand All @@ -70,3 +108,48 @@ API documentation for modules
:members:
:inherited-members:
:undoc-members:



API documentation for protocols and transports
**********************************************

.. autoclass:: kasa.protocol.BaseProtocol
:members:
:inherited-members:
:undoc-members:

.. autoclass:: kasa.iotprotocol.IotProtocol
:members:
:inherited-members:
:undoc-members:

.. autoclass:: kasa.smartprotocol.SmartProtocol
:members:
:inherited-members:
:undoc-members:

.. autoclass:: kasa.protocol.BaseTransport
:members:
:inherited-members:
:undoc-members:

.. autoclass:: kasa.klaptransport.KlapTransport
:members:
:inherited-members:
:undoc-members:

.. autoclass:: kasa.klaptransport.KlapTransportV2
:members:
:inherited-members:
:undoc-members:

.. autoclass:: kasa.aestransport.AesTransport
:members:
:inherited-members:
:undoc-members:

.. autoclass:: kasa.protocol.TPLinkSmartHomeProtocol
:members:
:inherited-members:
:undoc-members:
2 changes: 1 addition & 1 deletion kasa/protocol.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -168,7 +168,7 @@ async def query(self, request: Union[str, Dict], retry_count: int = 3) -> Dict:

:param str host: host name or ip address of the device
:param request: command to send to the device (can be either dict or
json string)
json string)
:param retry_count: how many retries to do in case of failure
:return: response dict
"""
Expand Down