indradhanush

Source: https://web.archive.org/web/20141216073338/https://gkbrk.com/blog/read?name=reverse_engineering_the_speedtest_net_protocol Author: Gökberk Yaltıraklı

Reverse Engineering the Speedtest.net Protocol

After finishing my command line speed tester written in Rust, I didn't have a proper blog to document this process. A few days ago I wrapped up a simple blogging script in Python so hopefully it works good enough to explain how everything works.

By now I have already figured out the whole protocol for performing a speed test but I will write all the steps that I took so you can learn how to reverse engineer a simple protocol.

The code that I wrote can be found at https://github.com/gkbrk/speedtest-rust.

indradhanush

minikube start --kubernetes-version=v1.11.0 --extra-config=apiserver.authorization-mode=RBAC -v 10

kubectl create clusterrolebinding add-on-cluster-admin --clusterrole=cluster-admin --serviceaccount=kube-system:default

minikube dashboard

indradhanush

1. Close slack
2. Open this file /Applications/Slack.app/Contents/Resources/app.asar.unpacked/src/static/ssb-interop.js
3. Append this to it

document.addEventListener('DOMContentLoaded', function() {
 $.ajax({
   url: 'https://cdn.rawgit.com/laCour/slack-night-mode/master/css/raw/black.css',
   success: function(css) {
 $("").appendTo('head').html(css);

indradhanush

## based on the blogpost here: http://blog.sjas.de/posts/colored-iptables-output.html

iptables --line-numbers -vnL |\
  sed -E 's/^Chain.*$/\x1b[4m&\x1b[0m/' |\
  sed -E 's/^num.*/\x1b[33m&\x1b[0m/' |\
  sed -E '/([^y] )((REJECT|DROP))/s//\1\x1b[31m\3\x1b[0m/' |\
  sed -E '/([^y] )(ACCEPT)/s//\1\x1b[32m\2\x1b[0m/' |\
  sed -E '/([ds]pt[s]?:)([[:digit:]]+(:[[:digit:]]+)?)/s//\1\x1b[33;1m\2\x1b[0m/' |\
  sed -E '/([[:digit:]]{1,3}\.){3}[[:digit:]]{1,3}(\/([[:digit:]]){1,3}){0,1}/s//\x1b[36;1m&\x1b[0m/g' |\
  sed -E '/([^n] )(LOGDROP)/s//\1\x1b[33;1m\2\x1b[0m/'|\

indradhanush

A collection of The Morning Paper posts relating to containers, operating systems etc.

In order of first appearance in The Morning Paper.

• On the duality of operating system structures
• Why threads are a bad idea
• Why events are a bad idea
• Unikernels: library operating systems for the cloud
• The scalable commutativity rule: designing scalable software for multicore processors
• Jitsu: just-in time summoning of unikernels

indradhanush

#!/bin/bash -eux
ARCH=${ARCH:-linux}
K8S_VER=${K8S_URL:-v1.1.8}
K8S_URL=https://storage.googleapis.com/kubernetes-release/release 
curl -Lo /usr/local/bin/kubectl ${K8S_URL}/${K8S_VER}/bin/$ARCH/amd64/kubectl
chmod +x /usr/local/bin/kubectl

indradhanush

tmux shortcuts & cheatsheet

start new:

tmux

start new with session name:

tmux new -s myname

indradhanush

• checkbox is done with the two brackets next to the P key
• checkbox is done with the two brackets next to the P key
• checkbox is done with the two brackets next to the P key
• checkbox is done with the two brackets next to the P key

indradhanush

If you are getting this in gdb on OSX while trying to run a program:

Unable to find Mach task port for process-id 57573: (os/kern) failure (0x5).
 (please check gdb is codesigned - see taskgated(8))

1. Open Keychain Access
2. In menu, open Keychain Access > Certificate Assistant > Create a certificate
3. Give it a name (e.g. gdbc)

indradhanush

Latency Comparison Numbers
--------------------------
L1 cache reference                           0.5 ns
Branch mispredict                            5   ns
L2 cache reference                           7   ns                      14x L1 cache
Mutex lock/unlock                           25   ns
Main memory reference                      100   ns                      20x L2 cache, 200x L1 cache
Compress 1K bytes with Zippy             3,000   ns        3 us
Send 1K bytes over 1 Gbps network       10,000   ns       10 us
Read 4K randomly from SSD*             150,000   ns      150 us          ~1GB/sec SSD