// the find
cloudwu/mptun
Multi-path Tunnel
A minimal peer-to-peer UDP VPN tunnel that bonds multiple network paths between two endpoints. Useful if you have two ISP connections and want to use both simultaneously for a single tunnel — a real problem for people in China with split routing needs. The author describes it as quick-and-dirty personal tooling, which is accurate.
Single C file (mptun.c) — the entire implementation is readable in one sitting. Multi-path bonding over UDP is genuinely useful and not something most VPN tools handle at all. The authentication via shared secret, while simple, covers the basic threat model for personal use. cloudwu is the author of skynet, so the C is at least written by someone who knows what they're doing.
Dead since December 2015 — ten years of no commits means no security patches, no IPv6, no fixes for whatever edge cases exist. The author openly calls the code ugly and untested in the README itself, which is honest but not reassuring for anything carrying real traffic. No traffic shaping, no load balancing strategy documentation — unclear whether it round-robins, picks fastest path, or just floods all paths. 1,242 stars but 311 forks suggests people copy it and move on rather than use it in production, which tracks.