Nikanos Polykarpou nikanos

The netfilter hooks in the kernel and where they hook in the packet flow

The figure below calls out

The netfilter hooks
The order of table traversal

Understanding the Memory Layout of Linux Executables

Required tools for playing around with memory:

hexdump
objdump
readelf
xxd
gcore

Common Options

-#, --progress-bar Make curl display a simple progress bar instead of the more informational standard meter.

-b, --cookie <name=data> Supply cookie with request. If no =, then specifies the cookie file to use (see -c).

-c, --cookie-jar <file name> File to save response cookies to.

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

Clarify and agree on the scope of the system

User cases (description of sequences of events that, taken together, lead to a system doing something useful)
- Who is going to use it?
- How are they going to use it?

Option 1: Command-line download extension as zip and extract

extension_id=jifpbeccnghkjeaalbbjmodiffmgedin   # change this ID
curl -L -o "$extension_id.zip" "https://clients2.google.com/service/update2/crx?response=redirect&os=mac&arch=x86-64&nacl_arch=x86-64&prod=chromecrx&prodchannel=stable&prodversion=44.0.2403.130&x=id%3D$extension_id%26uc" 
unzip -d "$extension_id-source" "$extension_id.zip"

Thx to crxviewer for the magic download URL.

Typing vagrant from the command line will display a list of all available commands.

Be sure that you are in the same directory as the Vagrantfile when running these commands!

Creating a VM

vagrant init -- Initialize Vagrant with a Vagrantfile and ./.vagrant directory, using no specified base image. Before you can do vagrant up, you'll need to specify a base image in the Vagrantfile.
vagrant init <boxpath> -- Initialize Vagrant with a specific box. To find a box, go to the public Vagrant box catalog. When you find one you like, just replace it's name with boxpath. For example, vagrant init ubuntu/trusty64.

Starting a VM

vagrant up -- starts vagrant environment (also provisions only on the FIRST vagrant up)

The Ultimate Unit Testing Cheat-sheet

Sinon Chai
Chai
Sinon

Git Cheat Sheet

Commands

Getting Started

git init

or

	import android.os.Build;

	import java.lang.reflect.Method;

	public class Device {
	/**
	* @return The device's serial number, visible to the user in {@code Settings > About phone/tablet/device > Status
	* > Serial number}, or {@code null} if the serial number couldn't be found
	*/
	public static String getSerialNumber() {

	Hi All!

	I've recently launched a tool that wraps many of the commands here with a user interface. This desktop application is currently available for macOS. There's a roadmap outlining planned features for the near future.
	Feel free to request any features you'd like to see, and I'll prioritize them accordingly.
	One of the most important aspects of this application is that every command executed behind the scenes is displayed in a special log section. This allows you to see exactly what’s happening and learn from it.

	Here's the link to the repository: https://github.com/Pulimet/ADBugger

	App Description:
	ADBugger is a desktop tool designed for debugging and QA of Android devices and emulators. It simplifies testing, debugging, and performance analysis by offering device management, automated testing, log analysis, and remote control capabilities. This ensures smooth app performance across various setups.