Mike Meredith

An Awesome Window Manager ECC Widget

Apr 012018

This is a continuation of an earlier post regarding ECC memory under Linux, and is how I added a little widget to display the current ECC memory status. Because I don’t really know lua, most of the work is carried out with a shell script that is run via cron on a frequent basis.

The shell script simply runs edac-util to obtain the number of correctable errors and uncorrectable errors, and formats the numbers in a way suitable for setting the text of a widget :-

#!/bin/zsh
#
# Use edac-util to report some numbers to display ...

correctables=$(edac-util --report=ce | awk '{print $NF}')
uncorrectables=$(edac-util --report=ue | awk '{print $NF}')

c="chartreuse"
if [[ "$correctables" != "0" ]]
then 
  c="orange"
fi
if [[ "$uncorrectables" != "0" ]]
then
  c="red"
fi

echo "ECC: $correctables/$uncorrectables "

This is run with a crontab entry :-

*/7 * * * * /site/scripts/gen-ecc-wtext > /home/mike/lib/awesome/widget-texts/ecc-status

Once the file is being generated, the Awesome configuration can take effect :-

-- The following function does what it says and is used in a number of dumb widgets
-- to gather strings from shell scripts
function readfiletostring (filename)
  file = io.open(filename, "r")
  io.input(file)
  s = io.read()
  io.close(file)
  return s
end

eccstatus = wibox.widget.textbox()
eccstatus:set_markup(readfiletostring(homedir .. "/lib/awesome/widget-texts/ecc-status"))
eccstatustimer = timer({ timeout = 60 })
eccstatustimer:connect_signal("timeout",
  function()
      eccstatus:set_markup(readfiletostring(homedir .. "/lib/awesome/widget-texts/ecc-status"))
  end
)
eccstatustimer:start()
...
layout = wibox.layout.fixed.horizontal, ... eccstatus, ...

There plenty of ways this could be improved – there’s nothing really that requires a separate shell script, but this works which is good enough for now.

Exploitation in History

History No Responses »

Mar 312018

If you read any history at all, you will encounter many incidents of exploitation – the English exploiting the Irish, the Irish exploiting the Scottish (see Dál Riata), the English exploiting the Scottish, the Scottish exploiting the English, everyone exploiting the Welsh, etc.

As an example of how it wasn’t as simple as sometimes claimed, there is a small sliver of Anglo-Irish ancestry in my family history. Undoubtedly they exploited the Irish back in the 18th century and before, but whilst they started as English, in every generation they married into the Irish aristocracy; so in at least one case the exploiters of the Irish were half or more Irish themselves.

And that is just one small corner of the world – it was happening just about everywhere.

Take another example – slavery. Everybody immediately thinks of the Atlantic slave trade, but those who look closer are in for a surprise – firstly that most slaves were made slaves by African slavemasters. And secondly the African slave trade had been going on uninterrupted since the Roman era – chiefly to the east.

At the same time the Atlantic slave trade was going on (16th-19th centuries), the Barbary pirates were also taking slaves – European slaves. It is estimated that 1-1.5 million were taken, although these figures are disputed, it is also the case that the Barbary slave raiding caused many small towns and villages to be deserted along the coastlines of Spain, Italy, and other places with a Mediterranean coastline.

And the early history of Europe is awash with slavery – Romans, Vikings, Angles, Saxons, and others, all participates in raiding for slaves – for local use, to Rome (in the early days), and to Byzantium (later on).

It is easy to look at one historical incident, and see the English exploiting the Irish, the Europeans exploiting Africans, etc. And there is an element of truth in that.

But it can also be seen not as the members of a nation exploiting the members of another nation, but as a type of person exploiting another type of person. The pure Marxist would claim it is the rich exploiting the poor, and there is an element of truth to that, but it is overly simplistic.

It is really more that the exploiter is the kind of person willing to do almost anything to enrich themselves including exploiting others. There isn’t anything wrong with getting rich or being rich as long as it is done honestly and reasonably.

There is a certain kind of person who does not care what level of suffering they cause to another person. For convenience let us call these people “sociopaths”.

In every example of exploitation in history, no matter what we label those responsible I am sure that the exploiters were sociopaths.

Now this is all very intellectually interesting, but perhaps the real question here is what should we do about the invisible sociopaths in today’s society? Because there are plenty – we might call them bankers, or slum landlords, or Russian oligarchs, or other things, but in the end what they all have in common is that they are sociopaths.

Giving The Sky The Finger

Fixing Wireshark’s Interpretation of RADIUS Operator_Name

Computing, Working Notes No Responses »

Mar 292018

For some reason when I look at RADIUS packet captures using Wireshark, the attribute Operator_Name is instead interpreted as Multi-Link-Flag (an integer rather than a string). I’m not sure what this is, but it is much more useful to me to be able to see the Operator_Name properly – and for example, filter on it.

It turns out this is easy to “fix” (if it is a fix) :-

Find the file radius/dictionary.usr (mine was /usr/share/wireshark/radius/dictionary.usr)
Edit that file, and comment out three lines containing “Multi-Link-Flag” which in my case appeared like :-
1. ATTRIBUTE Multi-Link-Flag 126 integer
2. VALUE Multi-Link-Flag True 1
3. VALUE Multi-Link-Flag False 0
Save the modified file.

After a restart, Wireshark now understands it.

It is possible that later versions of Wireshark have fixed this, or not – it is possible that the bug is down to whoever assigned RADIUS attribute codes!

Is Cambridge Analytica The Future?

Computing, General, Security No Responses »

Mar 252018

It seems likely that the company Cambridge Analytica paid Facebook for access to data and using it’s access, downloaded as much data as possible for nefarious purposes. Nobody should be that surprised at this.

Facebook does not host an enormously expensive social network just because it is fun; it does it to make money. It probably does this primarily through advertising, but selling access to social network data is always going to take place.

And from time to time, scandals when companies like Cambridge Analytica are going to take place. At which point Facebook will protest saying that it didn’t realise that the associated firm was doing such naughty things. And once the story drops out of the news, Facebook will carry on leaking data.

As the saying goes: “If you are not paying for it, you are the product.”

In the end, the only solution to something like this, is to produce some kind of peer-to-peer application that is as easy to use as Facebook, uses strong end-to-end encryption, and keeps our data private to those people and groups we choose to share it with.

The Hole

Invading Russia: Just Don’t

History, Politics No Responses »

Mar 182018

I recently scanned a blog entry claiming that Russia’s nerve agent attack on two people in Britain (plus the innocent bystander) wasn’t that big a deal, and that the reaction to it has been excessive. Well, perhaps.

But that blog went on to claim that militarily Russia is a bit of a pushover :-

It’s less than a third the size of the Soviet Red Army. Perhaps but it still has 1 million active personnel and 2.5 million reservists. Not a size you can discount!
It’s weaponry is obsolete. I can’t point to anything other than Russia spending $70 billion a year on defence to say otherwise, but “modernisation” crops up regularly in an discussion of the Russian military. And not in the sense of something that is required, but in the sense of something that is happening.

Lastly there was a reference to something that makes any student of history stare in amazement, and students of military history fall about the floor laughing. That is that Russia’s territory is flat and indefensible – ideal territory for mass tank battles (and indeed previously mass cavalry battles).

The Russian military knows this.

The last successful invasion of Russia whose territory has always been “ripe for invasion” was in the 13th century by the Mongol hordes.

There have been four major invasion attempts that failed to a greater or lesser extent :-

The Swedish military genius Charles XII tried in 1707, and was sounded beaten by the Russians assisted by the Russian winter.

Napoleon gave it a go in 1812, and the Russians inflicted a military disaster on him, again aided by a Russian winter.

Germany fought Russia during WWI, and managed to capture a considerable amount of Russian territory aided by the Russian revolution. But no major Russian cities were lost.

Again Germany tried in WWII, and Russia inflicted a major military defeat on them, with the assistance of the Russian winter.

The notion that anyone will try invading Russia is a bit ridiculous anyway (at least whilst Trump is Putin’s puppet).

So the threat from Russia is supposed “only” from cyberwar; which could be a damp squib or far more exciting than we believed possible. The fact is, we haven’t seen a full scale cyber attack against the UK, and don’t know what the results might be. Given the example of attacks against the Ukraine, we could expect wide-spread power blackouts, but it could be a great deal worse.

To be fair, I think the term “cyberwar” is a bit deceptive; attacking a nation’s connected technology is a tactic in a more widespread scheme of disruption and even war. There again, calling it “cyberwar” is a legitimate means to get funding for defences against such attacks.

The Window

Older Entries Newer Entries