Codeless Network Programming

FlowCODER is a WISIWYG network programming framework for rapid prototyping, debugging, validation, fuzzing as well as functional, load, and security testing of computer networks. It allows building and decoding packets for a variety of network protocols, sending them on the wire, receiving and analyzing incoming network traffic, matching requests with replies, keeping and changing the state and much more.

FlowCODER includes a visual network programming language, a WYSIWYG IDE and a packet processor. A FlowCODER program is a flowchart built from graphical blocks interconnected with software wires.

What is FlowCODER good for?

  • Cyberspace Protection and Coding
  • Network Health Check
  • Prototyping IoT Stacks
  • IPS development
  • MITM Modeling
  • Remote Network Probing
  • Custom Packet Processing
  • Pen Testing
  • Network Stack Fuzzing
  • Regression Testing
  • DoS and DDoS Simulation
  • Stress Testing

Local Execution

Local Execution is the simplest case. All packets sent by FlowCODER originate on a local host. Packets coming back in response are processed there as well.

Cloud Execution

Only FlowCODER IDE components run locally. A Flowchart, once created, is shipped for execution to a Cloud running multiple instances of Flowchart processor engine. Packets are originated and processed in a Cloud. Local user gets back diagnostics and statistical data.

on-the-fly deep packet Mods

Playing MITM in a Cloud. Flowchart sees the packets passing between a pair of network end-points, and could modify them at any stack layer.

Key Features
WYSIWYG Flow Definition

A finite-state machine built from graphical blocks connected with software wires. The machine sends, receives, analyzes packets and changes state based on the analysis.

WYSIWYG Packet Composer

Build any packet from scratch. Select the layers and the stacking order. Mandatory elements are added by default. Optional elements are added with a few clicks.

Pcap is a Template

Your Pcap is your template. Import a Pcap file into FlowCODER and get an executable Flowchart template right away. You'll be up and running in 5 mins.

Auto Decoding

The incoming packets are delivered to Flowchart fully pre-parsed. The packet received or any part of it can be saved into a local or global variable for further use.

Auto Encoding

Change a packet field on the fly by assigning a new value to a field. Encoding is performed automatically before the packet hits the wire.

MITM Proxy

FlowCODER can play a role of a MITM Proxy. The passing through packets are decoded, modified at any layer and re-encoded on the fly.

Transport Stacks

One Flowchart works with any combination of stacks/protocols. If a particular protocol runs over UDP and TCP, the same Flowchart will work for both.

Running in a Cloud

FlowCODER Flowchart processor can run locally or in a Linux VM inside the Cloud. The latter allows for unlimited scalability.

Graphical Debugger

Execute Flowchart step-by-step. Set/Clear breakpoints. View Execution Log for detailed debug output, Data Watch Pane for real time changes in variables' values.

Auto Parallelization

FlowCODER supports automatic parallelization. Run multiple independent calls, transactions, flows simultaneously.

Helper API

One can start an RTP session, call a crypto function and much more via an API call from a Flowchart block.

Calling Python

Flowchart blocks can call external Python scripts. That way a Flowchart can use host OS services.

Frequently Asked Questions

What is a simple use case for FlowCODER?

Suppose you have a Pcap file with a record of a stateful packet exchange between two parties. You want to simulate party A and see how B reacts if you change the way party A behaves slightly or not so slightly. This includes altering logic of the state machine Party A follows, and/or altering the messages it sends. And you want to do it quickly and with zero coding involved.

What is the main advantage of FlowCODER?

FlowCODER visualizes and speeds up development of packet driven finite-state machines and requires zero coding in many cases. One can start quickly by importing a Pcap file with the packet exchange of interest.

How FlowCODER compares to other packet generators?

Packet generators are often just Pcap file replayers. The best known example is tcpreplay. The fast ones usually are Intel DPDK based (CISCO T-Rex). Products of this category are either stateless, or support very simple states only (SYN/SYN ACK). Another category of the tools is targeted for testing networking state machines at higher stack layers. Those systems are usually configured via a set of static GUI tables, have no or limited programmability and support for a limited set of protocols. Then there is Scapy. It's programmable, but one has to know Python from the get-go, slow (it's Python after all), with a very limited set of L4-L7 protocols supported.

FlowCODER is fully stateful, WYSIWYG programmable at any stack layer, fast (coded in C++), scalable, with a huge and growing library of supported protocols. It allows on the fly editing of packets at any stack layer and importing of a Pcap file as a starting point of designing a networking state machine. No other tool has a full stack packet editor as powerful as SafePcap.

Do you translate Flowcharts into a scripting language?

No. We execute them directly. No scripting language is required.

At what stack layer can I build a flowchart state-machine?

Any layer from IP up, including binary encoded application layers.

Do I need to know Python?

Beginners and intermediate users are not. Scripting skills are useful for advanced data processing. Python will do. Perl as well. Even Javascript.

Do I have easy read/write access to packets' fields within a Flowchart?

Yes. You have full read/write access to *all* packet fields before pushing packets out to a wire, and when packets are received.

Can I save any field of a received packet into a variable?

Yes. An individual field, a whole PDU (networking stack layer data), or the whole packet. And you don't need to write any code to do that.

Can I run multiple flows in parallel on a single host?


Can I execute a Flowchart in a Cloud?

Yes. This is how the load is scaled.

Can I compose any standard or malformed packets on the fly?

Yes and yes. You can do packet fuzzing on the fly.