StructLayoutToolkitModel

StructLayoutToolkitModel (distribution name sltmodel) is a standalone, GUI-independent model library that handles StructLayout definitions and binary decoding. It provides the structure engine used by StructLayoutToolkitGui and is intended for reuse by other clients such as a CLI.

Installation

python -m pip install sltmodel

API

from sltmodel import CaptureDocument, PayloadStructDef
from sltmodel.resources import load_pcap_layout

capture = CaptureDocument.from_bytes(capture_bytes)
pcap_layout = load_pcap_layout()

The package provides capture parsing and IP fragment reassembly, conditional payload StructLayout definitions, StructInstance value helpers, InfoSize conversion helpers, bundled PCAP/PCAPNG/PE/ELF layouts, and Lua plugin hooks. It does not import or depend on Tkinter.

Built-in layouts

from sltmodel.resources import (load_elf_layout, load_pcap_layout,
                                load_pcapng_layout, load_pe_layout)

pe_layout = load_pe_layout()
elf_layout = load_elf_layout()

Lua plugins

LuaPluginManager loads *.lua files from a caller-supplied directory and applies their optional decode(instance) and encode(instance) hooks to StructInstance values. The manager has no GUI dependency; it requires Lupa when Lua plugins are loaded.

from sltmodel.lua_plugins import LuaPluginManager

plugins = LuaPluginManager(plugin_directory)
display_instance = plugins.apply_decode(decoded_instance)
encoded_instance = plugins.apply_encode(display_instance)

Development

uv sync
uv run pytest -q
uv run pytest --cov=sltmodel --cov-branch --cov-report=term-missing -q
uv build

Generate a browsable HTML coverage report in htmlcov/:

uv run pytest --cov=sltmodel --cov-branch --cov-report=html -q

Open htmlcov/index.html to inspect uncovered lines and branches.

To bump the package version, run one of these scripts from the repository root. Each script resolves pyproject.toml and uv.lock relative to its own location.

.\bump_major.ps1
.\bump_minor.ps1
.\bump_patch.ps1

The scripts update the sltmodel version in both pyproject.toml and uv.lock.