Simon Morgan

MikroTik hEX S (2025) AAISP Configuration

Sat, 16 May 2026 17:17:08 +0100

In my never-ending quest to screw up my Internet connection, I bought a MikroTik hEX S (2025), otherwise known by the slightly less catchy “E60iUGS”.

I used to have a RB2011UiAS-2HnD-IN which generally served me well, except the WiFi on it was well past its prime, so I bought some TP-Link Deco X55s. When they work, they’re alright; the trouble is they don’t work a lot more often than I’d like. they went through a phase where they’d constantly lose connection to each other, but that seems to have been fixed (I assume) with a firmware upgrade. Speaking of firmware upgrades, upgrading the firmware on them was always a nerve-racking experience as they’d always display the red-blinking-light-of-doom for a few minutes afterwards, even though eventually things would settle down. Combined with the fact that the settings are also extremely limited and you have to manage them via an app, I am not a fan of them. They’ve now been relegated to access points, and the hEX S is doing all the good stuff.

Goodbye Aquiss

Fri, 01 May 2026 23:05:12 +0100

By my reckoning I’ve been using Aquiss as my ISP for over 10 years. Needless to say, I’ve been pretty happy with them.

I like small ISPs because I like to think they give a shit about their customers. At the other end of the spectrum, you have Big Tech™ companies like Google and Cloudflare whose only motivation seems to be to get as rich and powerful as possible by exploiting their customers and users to the maximum extent they can get away with (and sometimes beyond).

Diagnosing DbContext disposed InvalidOperationException

Wed, 19 Feb 2025 19:37:58 +0000

While working on a large project that uses the unit of work pattern (and other things that generally make it harder to debug), I was getting an InvalidOperationException with an error about the DbContext being disposed.

It wasn’t obvious where this was happening, so I came up with the following:

using System.Diagnostics;

namespace My.Cool.Project
{
    internal class CustomDbContext : MyActualDbContext
    {
        protected override void Dispose(bool disposing)
        {
            if (disposing)
            {
                Debug.WriteLine("Disposing CustomDbContext");
            }
            base.Dispose(disposing);
        }
    }
}

Replace your DbContext with the above like this:

ELEGOO UNO R3 Notes

Sun, 09 Feb 2025 18:25:29 +0000

I’ve been farting around with an ELEGOO UNO R3 (that came as part of their Basic Starter Kit), today. I think it’s a pretty old-hat device at this point, but I thought I’d put some notes here, mainly for my future self, but also in case anybody else might find them useful.

Documentation

The tutorials and documentation distributed by ELEGOO is quite old at this point, and not very well written or presented. Fortunately, there isn’t much need to use it, as the device seems to be exactly the same as the Adafruit UNO R3, so all of their UNO R3 documentation should apply. No need to run any of their software either; just download the latest version of Arduino IDE and it should work out-of-the-box. If you’re using Windows, it’s probably best to install Arduino IDE before connecting the UNO to your PC because Arduino IDE installs a bunch of drivers that you’ll need for it to work.

Google Play Notifications Bug

Wed, 22 Mar 2023 20:50:24 +0000

In Google Play, the bell icon next to the search box was saying I have 1 unread notification. However, when I tap the icon, there are no notifications listed, and nothing in the “Offers” tab either.

I tried force stopping the app, clearing the cache and restarting, as well as restarting my phone, but neither made any difference.

After speaking to Google support, the “solution” turned out to be uninstalling all Google Play app updates. This got rid of the phantom notifications, even after Google Play was updated to the latest version.

Useful SQL Scripts

Fri, 16 Sep 2022 23:05:07 +0100

I’ve had these SQL Server scripts kicking around on my hard drive for a while now, so thought I’d post them here for posterity.

Find Duplicate Foreign-keys

For some reason SQL Server allows duplicate foreign keys. This script finds them for you.

WITH FKData
AS (
    SELECT fk.parent_object_id
        ,fkc.parent_column_id
        ,fk.referenced_object_id
        ,fkc.referenced_column_id
        ,FKCount = COUNT(*)
    FROM sys.foreign_keys fk
    INNER JOIN sys.foreign_key_columns fkc ON fkc.constraint_object_id = fk.object_id
    GROUP BY fk.parent_object_id
        ,fkc.parent_column_id
        ,fk.referenced_object_id
        ,fkc.referenced_column_id
    HAVING COUNT(*) > 1
    )
    ,DuplicateFK
AS (
    SELECT FKName = fk.Name
        ,ParentSchema = s1.Name
        ,ParentTable = t1.Name
        ,ParentColumn = c1.Name
        ,ReferencedTable = t2.Name
        ,ReferencedColumn = c2.Name
    FROM sys.foreign_keys fk
    INNER JOIN sys.foreign_key_columns fkc ON fkc.constraint_object_id = fk.object_id
    INNER JOIN FKData f ON fk.parent_object_id = f.parent_object_id
        AND fk.referenced_object_id = f.referenced_object_id
        AND fkc.parent_column_id = f.parent_column_id
        AND fkc.referenced_column_id = f.referenced_column_id
    INNER JOIN sys.tables t1 ON f.parent_object_id = t1.object_id
    INNER JOIN sys.columns c1 ON f.parent_object_id = c1.object_id
        AND f.parent_column_id = c1.column_id
    INNER JOIN sys.schemas s1 ON t1.schema_id = s1.schema_id
    INNER JOIN sys.tables t2 ON f.referenced_object_id = t2.object_id
    INNER JOIN sys.columns c2 ON f.referenced_object_id = c2.object_id
        AND f.referenced_column_id = c2.column_id
    )
SELECT FKName
    ,ParentSchema
    ,ParentTable
    ,ParentColumn
    ,ReferencedTable
    ,ReferencedColumn
    ,DropStmt = 'ALTER TABLE ' + ParentSchema + '.' + ParentTable + ' DROP CONSTRAINT ' + FKName
FROM DuplicateFK
ORDER BY ParentTable
    ,FKName

Find Auto-generated Key Names

When creating foreign-keys, SQL Server allows you to neglect to specify a name for them, and instead generated a name for you. This script finds them for you so you can give them a better one.

.NET Console App User Secrets

Wed, 20 Apr 2022 19:35:35 +0100

When scaffolding an EF Core .NET 6 console app recently, I discovered the it doesn’t support sourcing connection strings from the user secrets store unless you’re scaffolding an ASP.NET project. A lot of the documentation on the web, both from Microsoft and third-parties, also seems to assume that you’re using ASP.NET.

Here’s how I got it working with the minimum of fuss.

Create a user secrets store and add your secrets to it:

DrayTek Vigor 130 and MikroTik RB2011UiAS-2HnD-IN

Sat, 05 Mar 2022 11:43:01 +0000

If you just want to get the damn thing working as a modem (referred to as “bridge mode” in the DrayTek documentation) with your router, but don’t want to read about the ballache I had to go through

Select “Enable” on the “MPoA / Static or dynamic IP” page
Select “1483 Bridged IP VC-Mux” from the “Encapsulation” drop-down on the same page
Click “OK” to save and restart the “modem”

If you want to hear me have a good moan about the device, read on.

Wayback Machine Bookmarklet

Thu, 21 Oct 2021 18:42:48 +0100

I’ve come up with the following bookmarklet for searching the Internet Archive’s fantastic Wayback Machine for the current URL and thought I’d share it.

I found an existing bookmarklet that purported to do this, but it included the protocol scheme (the e.g. http:// part) in the lookup string, which meant it didn’t work. I’m not a fan of the regular expressions, but this was more succinct than constructing the lookup string via the Location object provided by the browser.

SDL2 on Windows with MSVC without Visual Studio

Mon, 18 Oct 2021 18:31:45 +0100

I’ve been interested in learning some low-level graphics programming and so figured a good way to do it would be via SDL and C.

I already had Microsoft’s C compiler available as I had a minimal (as much as anything to do with Microsoft or Visual Studio can be called minimal) Visual Studio Build Tools installation for Rust development, but I didn’t want to have to install the bloated mess that is Visual Studio.

ASP.NET Web Forms web site assembly definition errors

Fri, 13 Nov 2020 00:00:00 +0000

I have the unfortunate task of having to work with an ASP.NET Web Forms web site and have frequently had to deal with errors like the following:

Could not load file or assembly 'Newtonsoft.Json, Version=4.5.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)

This usually happens when switching from one branch to another in Git. Copying the correct assembly into the Bin directory didn’t help because it would just get replaced on build.

sp_MSforeachtable Table Filtering

Wed, 05 Aug 2020 00:00:00 +0000

SQL Server provides the handy sp_MSforeachtable stored procedure for executing the specified T-SQL for each table in a database. But what if you only want to run it for certain tables? I found myself in this boat but a bunch of the recommendations I came across didn’t work. The whereand parameter was clearly what I wanted. However, say we wanted to filter out all tables whos names didn’t start with “Foo”:

WiFi Calling and the Billion 8800NL R2

Sun, 03 May 2020 00:00:00 +0000

I have a Moto G7 Power (XT1955-4) and recently switched to EE because they support WiFi calling with that model. The trouble is, I could not for the life of me get it working. The WiFi calling setting was enabled but whenever I’d go to make a call, I’d get an error telling me to connect to a wireless network. Needless to say I was connected to my WiFi and had no connectivity issues.

Verifying RSA signatures using .NET and C#

Sat, 29 Feb 2020 00:00:00 +0000

I recently found myself wanting a system to cryptographically sign and verify files. I came up with the following method which uses a combination of the OpenSSL command-line utility and the .NET RSA class. I used the version that’s part of .NET Core 3.1.

This post assumes some familiarity with encryption, specifically public/private key encryption.

First we generate the public and private keys and sign the file:

# Generate the private key.
openssl genpkey -algorithm rsa -out privkey.pem -pkeyopt rsa_keygen_bits:4096
# Generate the corresponding public key
openssl rsa -in privkey.pem -outform PEM -pubout -out pubkey.pem
# Sign important.zip, storing the signature in important.zip.sig
openssl dgst -sha256 -sign privkey.pem -out important.zip.sig important.zip

The code for verifying the file signature should be fairly straightforward. By default OpenSSL stores the keys in PEM format. The .NET cryptography library doesn’t seem to support loading these directly and so I had to write some supporting code for wrangling the PEM file into a format that the RSA class would like, specifically a byte array.

Windows Services, Named Pipes and UnauthorizedAccessException

Fri, 14 Feb 2020 00:00:00 +0000

I was working on some proof-of-concept code whereby an unpriviledged client would communicate with a Windows service using protocol buffer serialization over a named pipe. I was doing this using .NET Core 3.1 and the Microsoft.Windows.Compatibility package.

The transmission of the data between the processes worked great when I was just using two unpriviledged console apps. I started running into issues when I made the switch to a Windows service. Sending data from an unpriviledged process to a Windows service doesn’t seem to work by default as Windows services run with elevated priviledges. When trying to send data from the client I’d get the following exception:

Swashbuckle generates incorrect Swagger API URL

Thu, 16 Jan 2020 00:00:00 +0000

I recently encountered an issue while using Swashbuckle whereby everything would work fine when running it locally but the deployed version would use incorrect API URLs.

https://server.example.net/app/foo/bar?a=123

would become

https://server.example.net/foo/bar?a=123

The issue seems to be caused by the fact that server.example.net is an API gateway. This seems to prevent Swashbuckle from correctly inferring the URL of the ASP.NET Core app and so it doesn’t generate the server part of the schema. This results in API requests (i.e. /foo/bar?a=123) getting sent to the root of the server.

Compound primary keys and NHibernate event listeners

Thu, 07 Nov 2019 19:44:41 +0000

Recently I had to write some code to log CUD operations done via NHibernate. The requirement was to log the following:

The type of operation (insert, update, delete)
The primary key property name(s) and value(s) of the entity being operated on
For updates, the property name(s) and the old and new values

It was pretty straightforward apart from retrieving the primary key. If the key is a scalar then it’s pretty straightforward:

HashSet, IEquatable and Contains

Thu, 05 Sep 2019 18:47:41 +0100

I recently came across some unintuitive and confusing (but understandable) behaviour when dealing with HashSet<T> where T : IEquatable. I’d written a class that implemented IEquatable based purely on the ID of the object. The trouble was that HashSet.Contains was saying that it didn’t contain the object I was passing it even though it contained an object with the same ID.

Here’s a trimmed-down example that exhibits the same behaviour:

Windows Store Error Code 0x80070005

Sat, 13 Jul 2019 11:44:50 +0100

I recently starting an issue where none of the programs I’ve installed via the Windows Store would update. Specifically they’d fail during the installation with an error code of 0x80070005 with no actual description of what the problem is (Microsoft still erroring like it’s 1989).

I searched all over the place but either I wasn’t willing to try the solutions because they were unreasonable, such as wiping my user profile because it might be corrupted with no way of checking whether this was actually the case, or they simply didn’t work.

ASUS RT-N66U IPv6 with Merlin

Sun, 09 Jun 2019 18:28:57 +0100

In a previous post I described how to get IPv6 working on the ASUS RT-N66U using the stock firmware. I’ve since switched to using the unofficial Merlin firmware.

While the settings in the previous article still apply, Merlin has more settings exposed and, at least in my case, failing to change the Prefix Length from the default 64 to 56 left IPv6 in a broken state. This led to various network issues such as avatars in the Twitter app taking forever to load, Steam being dog-slow on my Ubuntu 18.10 laptop etc.

Amazon Fire HD 8 System Apps on Home Screen

Mon, 26 Nov 2018 18:42:53 +0000

I recently got an Amazon Fire HD 8 tablet and for the most part it’s been running fine. However, I encountered a weird and annoying issue where, all of a sudden, I had what seem to be system/hidden apps showing up on my Home screen.

The apps in question were, IIRC, Device Setup, Downloads, Music, Kindle Store and maybe one more that I can’t find/remember.

The solution was to go to Settings → Apps & Notifications → Manage All Application → Home Pages → Storage. When there, tap Force Stop and Clear Data. That should get rid of the stray icons.

The Forgotten Ideas in Computer Science Notes

Tue, 20 Mar 2018 14:14:36 +0000

I recently watched Joe Armstrong’s Code BEAM keynote talk about forgotten ideas in computer science and thought it would be useful to make some notes. They’re mostly in the form of links to things that he mentions in his talk.

The Talk

The Tweets

I’m interested in the forgotten ideas of computer science. Needed for a talk.

Can you post examples of great CS ideas that have been largely forgotten.

Examples: Linda tuple spaces, Boyer-Moore algorithm

ASUS RT-N66U IPv6

Tue, 17 Oct 2017 16:32:45 +0100

I’m using an ASUS RT-N66U and my ISP is Aquiss (an Entanet reseller). I wanted to get IPv6 working.

After a little bit of fiddling, the following settings seem to have done the trick:

Connection type: Native
Interface: PPP
DHCP-PD: Enable

Auto Configuration Setting: Stateless

Connect to DNS Server automatically: Enable

Enable Router Advertisement: Enable

Hope this helps anybody else in the same situation.

WHMCS Smarty {include} Not Working

Mon, 11 Sep 2017 16:54:49 +0100

I’ve been using Smarty templates a bit recently while working with WHMCS and ran into an issue. When trying to do {include 'some_template.tpl'}, I was getting no output. Smarty seemed to just stop all processing at that point. The fix was maddeningly simple, especially as I’d tried a bunch of different variations of absolute and relative paths.

If your template is in a file called some_template.tpl, you need to use:

{include './some_template.tpl'}

In the case of WHMCS, templates are stored in a directory called templates, but you don’t need to specify that as part of the path.

WHMCS 500 Error

Fri, 01 Sep 2017 15:47:33 +0100

While working on an addon module for WHMCS I kept getting a generic 500 error code and a blank page. I was pretty sure it was a problem in my code but there was nothing in the XAMPP error.log or the WHMCS admin dashboards so I had no way of tracking down the cause.

I managed to finally track down the cause by enabling the Display Errors option under Setup → General Settings → Other.

OAuth for the Confused

Mon, 28 Aug 2017 12:13:41 +0100

While working on some code recently I ended up learning far more about OAuth than I ever wanted to know and so I thought I’d share my pain with the Internet.

This guide will cover OAuth 1.0a as that’s what I’ve been working with.

OAuth is an open standard for access delegation, commonly used as a way for Internet users to grant websites or applications access to their information on other websites but without giving them the passwords.

JavaScript Prototypes for the Confused

Tue, 30 May 2017 12:09:04 +0100

Objects can have a prototype and a prototype is just another object. We can get an object’s prototype using the Object.getPrototypeOf method.

Object.getPrototypeOf({}); // → {}

Yes, JavaScript really loves objects. It’s objects all the way down. Actually that’s not completely true:

Object.getPrototypeOf(Object.getPrototypeOf({})); // → null

The first call to Object.getPrototypeOf gave us the prototypical object—the one that acts as the prototype for practically all objects—and calling Object.getPrototypeOf on that gives us null. You’ve got to stop somewhere, right?

JavaScript Properties for the Confused

Mon, 08 May 2017 16:35:03 +0100

Like a lot of things related to JavaScript, the syntax and semantics of properties can be a little tricky to wrap your head around. Hopefully this article will serve to simplify and clarify things.

Our first step is to do away with the idea of arrays. But wait, arrays are important, surely? Yes, but they’re just conceptual baggage when it comes to understanding properties because arrays are also objects. And don’t call me Shirley.