Add mac address as connection for matter device

[MrEbbinghaus]

Proposed change

This PR adds a mac address connection for matter devices that have a mac address, so that they can be matched with existing devices in the registry.

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• Dependency upgrade
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• This PR fixes or closes issue: fixes #
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[marcelveldt]

Nice work!

[agners]

So this PR seems to cause a bit of headache here. I see devices with many MAC addresses, and things merging weirdly on dev

[MrEbbinghaus]

@agners Oh no, that doesn't look right.
Can you send the matter diagnostics?

I suspect the devices all share the invalid 00:00:00:00:00:00 address.
I knew this could happen (see #121257 (comment)), but this is a HA core level issue, so I removed the check for invalid mac addresses.

[agners]

I suspect the devices all share the invalid 00:00:00:00:00:00 address.

Yeah I have at least two devices which return 00:00:00:00:00:00.

I guess technically, this is a valid MAC address. But these devices don't use this as physical address (according to my AP). Technically, the Matter standard says NetworkInterface hardwareAddress field is mandatory and should contain "a" MAC address. I guess very strictly speaking, this is "a" MAC address, just not the valid/used one for that device 🙈

Anyhow, given that Matter devices return such addresses, this is more a Matter problem. I'd suggest to filter them out on Matter integration side.

[agners]

Btw, what is the exact use case/motivation behind this PR? Do you have a device where this connects up with other integrations or something?

I am a bit worried since MAC address privacy extensions become more and more commonplace. The Matter standard also mentions that when it comes to host name generation. It seems we have to expect that devices rotate MAC addresses:

For DNS‐SD a target host name is required, in addition to the instance name. The target host name
SHALL be constructed using one of the available link-layer addresses, such as a 48-bit device MAC
address (for Ethernet and Wi‐Fi) or a 64-bit MAC Extended Address (for Thread) expressed as a
fixed-length twelve-character (or sixteen-character) hexadecimal string, encoded as ASCII (UTF-8)
text using capital letters, e.g., B75AFB458ECD.. In the event that a device performs MAC
address randomization for privacy, then the target host name SHALL use the privacy-preserving
randomized version and the hostname SHALL be updated in the record every time the underlying
link-layer address rotates. Note that it is legal to reuse the same hostname on more than one inter­
face, even if the underlying link-layer address does not match the hostname on that interface, since
the goal of using a link-layer address is to ensure local uniqueness of the generated hostname. If
future link layers are supported by Matter that do not use 48-bit MAC addresses or 64-bit MAC
Extended Address identifiers, then a similar rule will be defined for those technologies.

[MrEbbinghaus]

Unfortunately, I can't work on this today.
@marcelveldt Should this PR be reverted and put on hold until there is a patch for the core code to validate mac addresses?
Or should I add the checks for now, and maybe it gets fixed later in the core?

---

@agners 00:00:00:xx:xx:xx (and a bunch of other addresses) are not valid identifiers.
'Values based on a zero-valued OUI [...] shall not be used as identifiers.'
See: https://standards.ieee.org/wp-content/uploads/import/documents/tutorials/eui.pdf

---

I still have the checks that I removed here:

https://github.com/MrEbbinghaus/core/blob/e3f84fd007d08b060b4a5c478427df94fa82dcb5/homeassistant/components/matter/adapter.py#L50-L67

    def is_NULL(self) -> bool:
        """Check if the address is NULL value/should not be used.

        See: https://standards.ieee.org/wp-content/uploads/import/documents/tutorials/eui.pdf
        'Values based on a zero-valued OUI [...] shall not be used as identifiers.'
        """
        return self.address[:3] == b"\x00\x00\x00"

    def is_individual(self) -> bool:
        """Check if the address is an individual address, not a group address."""
        return self.address[0] & 0x01 == 0

    def _valid_connection(self) -> bool:
        return self.is_individual() and not self.is_NULL()

[agners]

@agners 00:00:00:xx:xx:xx (and a bunch of other addresses) are not valid identifiers.
'Values based on a zero-valued OUI [...] shall not be used as identifiers.'
See: https://standards.ieee.org/wp-content/uploads/import/documents/tutorials/eui.pdf

Oh I see. I just looked up OUI, and with 00:00:00 Xerox came up, so assumed it is valid.

[MrEbbinghaus]

Btw, what is the exact use case/motivation behind this PR? Do you have a device where this connects up with other integrations or something?

@agners I have a matter device that wants to connect to the manufacturer to make auto-updates, which I don't want.

My router integration adds a switch for every connected device to block its internet access.

And it annoys me that I regularly have duplicate devices in my list.

[MrEbbinghaus]

@agners You are right to point out that there will be more devices with address rotation in the future, which could be an issue for mac addresses to be used as unique device identifiers. However, this should not cause any severe problems in HA.
In the worst case, two integrations would have two different Mac addresses for the same device and the devices can't be merged automatically. But this is the status quo, so no UX degradation.
It is unlikely that 'randomly' generated Mac addresses for privacy will collide, and it would not only be a problem for HA alone but possibly for the entire network.

Also, as I understand it, the addresses are only stored until the integration that provides the entity reloads. So even when the addresses rotate, it wouldn't spam the device registry with addresses.

(Also, I guess that most Matter devices won't move from network to network regularly, and therefore manufacturers won't bother with implementing privacy enhancing rotating addresses.)