News
The story of my life. As told by me. For more amusing anecdotes, please visit the archive.
Ironic vandalism
February 12, 2010 11:31:43 AM UTC
Those of you familiar with the London Underground will no doubt be aware of the variety of adverts that you get to enjoy as you are ferried up and down escalators. I never really pay them that much attention, but I spotted an amusing thing this morning. There are a number of posters advertising cosmetic surgery, which in themselves are fairly harmless. However, some people appear to have taken offense to these and have reacted by sticking various labels over the top of these ads saying things like "Don't buy this sexist shit" and "You are beautiful. You don't need this". I always thought it fairly amusing that a group of people should use the medium of impersonal and social pressure to rile against an industry that appears to profit from other people's susceptibility to impersonal and social pressure. I'm not sure if it's genius or stupid.
I was idly thinking if there was some sort of concise yet witty retort that could also be stuck up alongside the original stickers. Something like "Ignore the stickers! Be yourself!" written on a sticker and stuck to a poster would be suitably contradictory. As I was musing this, I noticed on the next poster up the escalator that someone had been thinking along the same lines. Their sticker? "It worked for Michael Jackson". Tasteless? Almost certainly. Funny? Yes.
On a different note, this site is now fully IPv6'd up! Hurrah. I mean fully in the actual literal sense, in that all the DNS responses from the root server downwards contain AAAA records. The IPv6 DNS glue is in place and working marvellously.
When things work better than expected.
February 1, 2010 10:46:46 AM UTC
Since my last post, I've been running a slightly experimental spam filter. The idea being to stop most spam before it gets to spamassassin, which is relatively expensive to run (in terms of resources).
It's been far too effective. As can be seen on SpamWatch, processed spam has basically dropped to zero. It's so idle, it's given up reporting altogether.
Don't panic, because I'm currently devising a brand new way of generating pretty graphs out of the vast array of data generated by millions of malware-infested Windows XP desktops which repeatedly attempt to connect to my mailserver in the hope that they might actually put some gibberish in front of my face that may entice me into spending some money on Viagra. I've a plan!
Spammage. More of it. Loads of it! Yay!
January 19, 2010 10:50:36 AM UTC
For some reason, my ongoing battle against spam isn't yet fully won. Whilst the current combination of MTAs, counter-measures and cluster-bombs are effective, there's still a few problems.
Actually, there's one specific problem: I don't have enough resources (specifically, memory) to run my spamassassin bayesian filter any more. I'm getting a mail from cron pretty much every day detailing the times at which spamassassin fell over the previous day, mostly due to running out of room in which to manoeuvre. Yesterday, it fell over 5 times.
I've always been interested in the idea of greytrapping and tarpitting mail. Simply put, this is a fairly simple way of detecting spam that assumes that most spammers don't obey the SMTP RFC standard. The greytrapping bit works by initially rejecting all unrecognised From/To/IP Address tuples with a "Try again later" message. Proper mailservers obey this and when they reconnect a bit later get allowed through. Spamming botnets have an aim to deliver as much mail as fast as possible, so tend to ignore this and not bother reconnecting.
The tarpitting bit takes a blacklist and slows down the connection of any blacklisted IP address, basically only allowing something silly like one byte every hour. The idea of this is to use up the resources of the evil mailserver by holding the connection open as long as possible.
The obvious way to do this is to use spamd on OpenBSD. Rather than being an MTA in its own right, this basically sits in front of the MTA and does the above cleverness. It's also meant to be quite efficient, because it doesn't care about the mail body.
Now, I hear you ask, what if the spammer does obey the SMTP RFC and delivers a mail later? Won't they get whitelisted? Well, yes. But this is why spamd on its own isn't a good idea. So I'll be keeping my existing content filtering thingie in place. The nice thing is that the expensive process of looking through the mail content won't happen on every single mail that drops into my mailserver, but only those that get past spamd. This should (in theory) stop it from falling over.
The main problem I have now, is that if I implement this, my spamwatch stats will go all screwy, because there's no real way to know how many spams that spamd rejects (you can deliver multiple mails over a single SMTP session). I'll keep it going, and hopefully there'll be a huge dropoff in the number of spams rejected by spamassassin, because they'll be caught by the spamd filter. It'll be interesting finding out.
Down, then up again.
January 4, 2010 12:27:14 PM UTC
It's weird how the new year has brought lots of broken things. My internet broke at home, the bike wouldn't start this morning, glassfish crashed, the database server ran out of memory, my phone stopped sending texts etc. etc.
Doom and gloom.
Anyway, I've fixed most of these things by kicking them. For the rest, I'll plough on with the niggling thought in my mind that somewhere in my small corner of the world, something isn't working properly.
At least we've not had any earthquakes.
My life is complete(-ish)
December 11, 2009 12:54:37 PM UTC
Now, Chopin.
P.S. as the piano mover was hauling it into the room, I mentioned that it was of a particular attachment, given that it was the piano I leant on. He casually mentioned that "his mate, Tim Minchin, had been trying to get him to learn for the past 4 years". Seriously? Tim Minchin?! Not sure if I was being had on. If I were, it's a fairly obscure joke to make...