5G Proxy Client

Android SOCKS5 TUN tunnel client — routes the device's entire network traffic through a remote SOCKS5 server using a TUN virtual interface. No root required.

Features:
- User-space TCP state machine forwarded via SOCKS5 CONNECT
- UDP / DNS / QUIC relay via SOCKS5 UDP ASSOCIATE (UDP-in-UDP or UDP-in-TCP 0x04)
- Remote DNS (fakedns) with fake IPv4 (198.18.0.0/15) and fake IPv6
- IPv4 + IPv6 dual-stack support
- Per-App routing modes: Global, Allowlist, or Exclusion
- Auto-reconnect with exponential backoff on connection drop
- Live traffic statistics (up/down bytes & session count) in persistent notification
- Custom primary & secondary DNS servers
- Start tunnel on boot
- Quick Settings tile for one-tap tunnel toggle
- Multiple profile management with JSON export/import via clipboard
- Native C (epoll) engine + JNI + Kotlin UI

Privacy notes:
- While the tunnel is up, the proxy server's hostname is re-resolved outside the tunnel (needed to follow DDNS / IP changes without tearing the TUN interface down). That lookup is sent to the DNS servers of the network the tunnel actually runs over. The custom DNS servers above are used only as a fallback when that resolver gives no answer, and the fallback is written to the log.
- With Remote DNS enabled, DNS queries from apps are relayed to the proxy exit instead of being answered locally.

Open source (MIT), reproducible builds.