# s5p -- Project

## Purpose

A lightweight SOCKS5 proxy server that chains connections through Tor and/or
arbitrary proxy hops (SOCKS4, SOCKS5, HTTP CONNECT).

## Motivation

Existing solutions (`proxychains-ng`) rely on `LD_PRELOAD` hacks, only work
on Linux, and intercept at the library level. s5p is a proper SOCKS5 server
that any application can use natively -- no injection required.

## Architecture

```
                  TCP          tunnel        tunnel
Client -------> s5p -------> Hop 1 -------> Hop 2 -------> Target
        SOCKS5       proto1         proto2         protoN
```

- **server.py** -- asyncio SOCKS5 server, chain builder, bidirectional relay
- **proto.py** -- protocol handshake implementations (SOCKS5, SOCKS4/4a, HTTP CONNECT)
- **config.py** -- YAML config loading, proxy URL parsing
- **cli.py** -- argparse CLI, logging setup

## Dependencies

| Package | Purpose |
|---------|---------|
| pyyaml  | Config file parsing |

All other functionality uses Python stdlib (`asyncio`, `socket`, `struct`).

## Design Decisions

- **No LD_PRELOAD** -- clean SOCKS5 server, works with any client
- **asyncio** -- single-threaded event loop, efficient for I/O-bound proxying
- **Domain passthrough** -- never resolve DNS locally to prevent leaks
- **Tor as a hop** -- no special Tor handling; it's just `socks5://127.0.0.1:9050`