UDP over TCP
It's a proprietary protocol created by SagerNet, not part of shadowsocks.
The UDP over TCP protocol is used to transmit UDP packets in TCP.
Structure
The structure can be replaced with a boolean value when the version is not specified.
Fields
enabled
Enable the UDP over TCP protocol.
version
The protocol version, 1 or 2.
2 is used by default.
Application support
| Project | UoT v1 | UoT v2 |
|---|---|---|
| sing-box | v0 (2022/08/11) | v1.2-beta9 |
| Xray-core | v1.5.7 (2022/06/05) | f57ec13 (Not released) |
| Clash.Meta | v1.12.0 (2022/07/02) | 8cb67b6 (Not released) |
| Shadowrocket | v2.2.12 (2022/08/13) | / |
Protocol details
Protocol version 1
The client requests the magic address to the upper layer proxy protocol to indicate the request: sp.udp-over-tcp.arpa
Stream format
| ATYP | address | port | length | data |
|---|---|---|---|---|
| u8 | variable | u16be | u16be | variable |
ATYP / address / port: Uses the SOCKS address format.
Protocol version 2
Protocol version 2 uses a new magic address: sp.v2.udp-over-tcp.arpa
Request format
| isConnect | ATYP | address | port |
|---|---|---|---|
| u8 | u8 | variable | u16be |
isConnect: Set to 1 to indicates that the stream uses the connect format, 0 to disable.
ATYP / address / port: Request destination, uses the SOCKS address format.
Connect stream format
| length | data |
|---|---|
| u16be | variable |
Non-connect stream format
As the same as the stream format in protocol version 1.