The Network Protocol Tool (npt)

Overview

The source code contained in the npt directory is broadly split into three categories:

• input parsers (parser_*.py), that take a protocol described in a given format, and generate the intermediate representation;

• helper classes (rfc.py, protocol.py, util.py, and helpers.py), that are used to construct and inspect the intermediate representation; and

• output formatters (formatter_*.py), that take the intermediate representation, and produce output in a given format.

Additionally, there is a directory of examples (/examples), containing a number of protocol definitions in each of the input parsers, and a helper script that performs the end-to-end process of taking a protocol description, and generating output in a specified format.

Getting started

The project uses Pipenv for dependency management. To begin, run:

pipenv install --dev -e .

to create a Python virtual environment with appropriate packages installed, and the npt tool installed in editable mode ready for development. Then, run:

pipenv shell

to start the virtual environment, within which you can run the scripts.

To run the project's test suite, run:

pipenv run tests

Generating a protocol description

npt can be executed as follows:

python npt -d <output-dir> -f <output-format> <document>

where:

• is the name of the document to be processed. This is either a local filename, an RFC name, or an internet-draft name.

• -d output_dir, --dir output_dir is the directory in which to place results

• -f formats, --outformat formats : List of outputs to generate from parsing the draft/rfc specification. formats is a comma separated string. In generating the output, the script performs a depth-first search of the intermediate representation, to determine the order in which the necessary functions of the specified formatter are called.

  Currently supported output formats are :

  • simple : a textual representation of the parsed IETF specification
  • rust : a rust protocol parser.

Example Usage

   python npt -d foo -f simple examples/draft-mcquistin-quic-augmented-diagrams-03.xml
   python npt -d foo -f simple examples/draft-mcquistin-augmented-ascii-diagrams-07.xml
   python npt -d foo -f rust examples/draft-mcquistin-augmented-udp-example-00.xml
   python npt -d foo -f rust examples/draft-mcquistin-augmented-tcp-example-00.xml

Acknowledgements

This work is funded by the UK Engineering and Physical Sciences Research Council, under grant EP/R04144X/1. See more information about the project.