Categories
Hardware

Xiaomi purifier hack with NFC tags

It’s been over two years since my last rant.

I can now happily say this NFC tag hack works. No need to hack your purifier like with their previous kit (I almost purchased the kit — but eventually decided against it; was it worth the trouble?).

But these NFC tags are significantly easier to use. After ignoring the “your filter is at 0%” for the past ~6 months, it’s back at 100% with this. Remember to dust off and clean it once in a while (but even if you don’t, the air coming out is still cleaner).

So, entirely, worth it!

Speaking of which — Ikea has a whole new range of cool purifiers (including built-in a table). Quite cool (and sad that it’s come to this with all the pollution)!

Categories
Apple Hardware Linux Misc Networking Software Windows www

Remote desktop and Wake-on-LAN

Shan uses her iPad a lot, but a lot of the more serious (interior design) work needs to happen on AutoCAD or Photoshop. That is just not going to work on an iPad.

When we’re travelling (read: holiday) she’s carrying an old Lenovo ThinkPad 13 (great device!) just “in case” she needs to open AutoCAD and edit something minor or read the drawings/dimensions. But honestly, most of the time that device is turned off and dead weight.

But all the above is just an excuse to “I was bored, and I wanted to test something”: can I use an old Raspberry Pi (zero W) to remotely wake her Intel NUC, and then use Tailscale to use RD on her iPad? Well, yes I can.

I completed this using:

  • Tailscale to remote desktop from anywhere to home
  • Cloudflare Tunnels, Access and DNS to have a web interface to wake the desktop
  • A Linux device that’s always on and in the same LAN, and that’ll run a PHP script.

Prep work: enable WOL

First off: enable Wake-on-LAN (WOL) in the BIOS and in your Windows settings. This article explains it for Intel NUCs, but would be similar enough for most devices. The Device Manager pane looked different on our i5 NUC, but was close enough.

On Mac, you just need to enable it in the Energy preference pane, for Linux I have no clue. 🤷‍♂️

Second step: have a working Raspberry Pi (or any Linux device) in the same LAN. This device needs to be turned on 24/7, so use something that uses very little power.

I do have a more powerful RPi4 I wish I could've reused (running Docker and some other "serious" stuff; however it's currently in a different VLAN, and it's quite crucial the Linux device is in the same LAN as the device(s) you want to wake up), so I went with an old Raspberry Pi Zero W that was collecting dust (it used to run pwnagotchi).

On the Linux device, install etherwake. The command to run is quite simply etherwake aa:bb:cc:11:22:33 (= the ethernet MAC address of your device).

If this doesn’t wake your desktop, something is wrong and there’s no point continuing. Go and troubleshoot.

Install Tailscale and RD

On the (Windows) desktop and your iPad, install Tailscale. Login, and make sure it works by pinging from one to the other.

Then set up Remote Desktop on both (Windows, iPad). You should test and make sure you can properly connect using the LAN IP address and then the Tailscale IP address.

Fun fact: I create a DNS record for all my devices using Cloudflare DNS with the syntax of device-name.ts.yeri.be, so I don't need to ever remember IPs, and can easily ssh or ping devices without having to look up IPs. 
Cloudflare DNS screenshot, filtered on “ts”. I add both A and AAAA records (not shown in the screenshot)
Fun fact side track: I actually have a dynamic script that runs (on Linux) and creates hostname.ts.yeri.be for the Tailscale IP, hostname.wg.yeri.be based on the Wireguard IP, hostname.lan.yeri.be based on the LAN IP. This dyndns script runs every so often and updates IPs if needed. All this is running using Cloudflare DNS and their API. Super convenient.

Nginx, php and etherwake

I'm a 80s kid, so I'll use dirty PHP to run this script. I'm sure I'll go straight to hell for this, but yolo.

Install nginx and PHP (no need for MySQL and other stuff).

etherwake requires root to run (because it needs root access to create a weird magic ethernet packet). Create a file in /etc/sudoers.d/etherwake and add this line:

www-data ALL=(ALL) NOPASSWD: /usr/sbin/etherwake

This will allow www-data (nginx/php) to run /usr/sbin/etherwake using sudo, without password.

In /var/www/html/ create an index.php file with:

<html>
<head><title>Wake on Lan</title></head>
<body>
<p>Wake up <a href="mycooldesktop.php">My Cool Desktop</a>
</body>
</html>

And a mycooldesktop.php (or whatever) file with:

<?php
$output = shell_exec('sudo /usr/sbin/etherwake aa:bb:cc:11:22:33 2>&1');
echo "<pre>$output</pre>";
?>
<p><a href="..">Back</a></p>
It ain't pretty -- but it gets the job done. 

And be sure to edit the MAC address to match your desktop’s ethernet MAC address.

Cloudflare tunnels

Install Cloudflare Tunnel (via Zero Trust dashboard).

When creating a new tunnel, the dashboard will give you all needed commands to install the tunnel on your RPi — but be sure to select the right OS/architecture (arm64? arm? armhf?).

Easy.

And then point the tunnel to http://localhost. No need to mess around with SSL certs.

Lastly, set up Cloudflare Access (via the same Zero Trust dashboard): create a new application, and make sure only approved users can sign in (i.e.: using a pin code emailed to only approved emails).

I only allow access to my own emails, and my family, by using groups.

You can try it yourself via wol.superuser.one. You won’t get in. 🙂

Optionally, but recommended: lock down Nginx to only allow connections from localhost (127.0.0.0/8 and ::1) if using Cloudflare Tunnels, or Cloudflare IPs if using port forwarding with Cloudflare Access in front. 
Love my design skills… But it gets the job done: click that link, and it’ll execute etherwake.

To recap

  • We used Tailscale to create a VPN network between the desktop and the iPad. The big benefit is that Tailscale works effortlessly across NAT networks without having to open ports,
  • We used Cloudflare DNS so we don’t need to remember hostnames :),
  • We used Cloudflare Tunnels to make sure the RPi web interface is accessible across NAT (without port forwarding) and from anywhere,
  • We used Cloudflare Acces and locked down access to the right people using ACLs,
  • We used etherwake running on a RPi to wake up devices that are hibernating or turned off.

And that’s it really.

PS: technically WoL works with WiFi, but when I enabled WoL on the WiFi adapter, the NUC refused to hibernate/sleep for more than a minute, and kept waking itself up. So, there seems to be some kind of trigger in my network that keeps waking it up. Also, not sure if WoL via WiFi would work if the device is turned off (as opposed to sleep or hibernate). I just ended up using ethernet. 

PPS: both Cloudflare Tunnels and Tailscale use Wireguard tech in the background, so that's really cool. 
Categories
Hardware Networking Software

Xiaomi Phone Shipped With Censorship List

This summer, the Lithuanian government went public with an astounding finding. A Xiaomi phone sold in Europe — the Mi 10T 5G — could censor approximately 450 words and phrases, it said. The blocklist wasn’t active, but could be activated remotely. It was filled with political terms, including “Democratic Movement” and “Long live Taiwan’s independence.”

[…]

The accusations, which Xiaomi disputes, clarified just how fraught the West’s relationship is with China’s growing technology power. As China-based tech companies like Xiaomi and TikTok flourish, there’s still no playbook in North America or Europe to deal with their potential to censor or steer culture via algorithms.

“Western countries,” Abukevicius said, “are more and more reliant on technologies, and a big part of those technologies comes from countries which are not friendly, which we don’t trust, and it poses risks.

Source.

Categories
Errors Hardware

Bitflip

Categories
Apple Google Hardware

Custom CPUs

Google developing own CPUs for Chromebook laptops“.

Interesting to see that many years after Apple started creating their CPUs for the iPhone (and now laptops/desktops), so many companies are following. Google is not new to building their chips (TPU, Titan (used in security keys and as encryption module for servers/Pixel phones), and likely more), but quite new to more generalised computing CPU for phones and laptops.

And it makes sense — a lot of the generic CPUs were too generalist and not that great at their job (and are plagued with bugs). It came with heavy power usage. Having a ML/AI chip, a GPU chip, a generalist CPU chip (or two, one focussing on high performance, and one on efficiency, like the M1), one for security/encryption (Titan/T2), etc.

Curious to see how much of a head start Apple really has, and very eager to finally see some real innovation in the CPU space (sorry AMD with Ryzen: too little, too late).

Let’s see if Intel and AMD will be able to adapt and reinvent themselves and what it means for ARM (and the ARM IP issue in China), and if other architectures like MIPS are making a chance.