Packet Panic

A high performance network proxy written in Go that emulates bad network conditions to verify the fault-tolerance of distributed systems in adverse conditions.

Capable of transparently and bidirectionally intercepting 15+ Gb/s of layer 3 packets using the TUN kernel virtual interface.

Table of Contents

• How it works
  • Overview
  • Packet interception
• Requirements
• Installation
• Usage
• Configuration

How It Works

Overview

• Coroutines are dispatched to handle requests concurrently, apply packet loss/corruption/delay, forward to destination
  • Filter stages such as packet loss/corruption/delay are applied using probablistic models
• Each request is then forwarded to the original destination with a spoofed source address so that replies can also be intercepted and processed.

Packet interception

• The TUN Kernel Virtual Interface is brought up and configured by a user-supplied yaml (see pp.example.yaml)
• Configuration summary:
  • IP Range CIDR to intercept packets on, specified by config -> net_iface_cidr (example: 69.69.69.1/24) to intercept packets on Layer 3
  • An interface name (example: ppanic) set in config->interface_name)
  • An IP to output packets on, specified by config -> net_iface_cidr (example: 127.0.0.1/24 for loopback output)

Requirements

• go version >= 1.21.1
• Linux based OS (Windows is not supported due to the application fundamentally relying on Linux networking features)

Installation

Assuming you have Go installed and up to date, you can build the executable binary main with:

$ go build main.go

Usage

• If you want to intercept interactions with a device on localhost or loopback at a certain port (example: 8081), simply replace the destination IP address localhost or 172.0.0.1 (loopback) with an address in the IP CIDR range such as 69.69.69.7 assuming the example CIDR (69.69.69.1/24) was used.
• If you want to intercept interactions with an external device, you need to configure your DNS to use the IP range net_iface_cidr or manually change your application code to target an IP in that range, and set the net_oface_cidr to the actual target IP your application is reaching out to.
• Run the program using:

$ sudo ./main --config your/config/here.yaml

(replace your/config/here.yaml with the path to your configuration yaml file)

Configuration

Example configuration yaml, the path to which is a required argument of the program:

net_iface_cidr: "69.69.69.1/24" # TUN interface network CIDR
net_oface_cidr: "127.0.0.1/24" # outgoing packet network CIDR - choose where to route packets to
net_return_addr: "69.69.69.2" # IP to set the spoofed src address to - must be in the `net_iface_cidr` range.
interface_name: "ppanic" # name of the TUN interface brought up by packet panic
debug: true # debug mode
log-cli: true # log CLI to output or /var/log/ppanic