GNU/Linux

OTRS 5 - Unable to fetch email from external accounts

A few weeks back I got a call from a customer who complained that OTRS had been idle for a day without creating any new tickets. After some initial troubleshooting it became clear that OTRS was simply no longer able to retrieve mail.

Gentoo kernel upgrade checklist

These steps are partly dependent on my personal Gentoo installation and should not be viewed as a general recipe. Please refer to the official Gentoo wiki on the topic instead. I’m using genkernel to generate an initramfs and GRUB2 as my boot loader.

The Internet of Things are flooding my website

Most people have probably heard about the Internet of Things (IoT) by now and how these devices are constantly drafted for your friendly neighborhood botnet. My little place on the interweb is currently gaining popularity among my DVR based visitors. You know the type: running a public telnet service, using hard coded accounts and may occasionally be seen sporting an additional backdoor on port 31337.

These bots are posing as Googlebot, but they are effortless to identify due to their use of the old and largely abandoned HTTP 1.0 protocol.

How to build your own kernel on Slackware Linux

With all the noise lately about Dirty COW (CVE-2016-5195) and the lack of patched kernels from Slackware’s “Benevolent Dictator for Life”, I decided it was time to roll up the sleeves and get it done. Since Slackware doesn’t have a “sophisticated” build system and all that grease, it’s a trivial matter to step up to the plate and take responsibility for your own system. I’ll be using “vanilla-kernelversion” as my tag for the kernel and initrd. Also notice that I build my kernels as a normal user.

Dovecot Panic: file mail-transaction-log.c

I got a call last week from a client that was having some issues with retrieving email from a Dovecot IMAP server. The client was connecting over TLS and was using an Apple mail client. Upon checking the mailserver log, I was greeted with a flood of rather vicious looking errors. I’m not gonna post the entire backtrace since its rather long, but you’ll get the idea.