shadowsocks/shadowsocks-rust · error

udp datagram requires IP address target

Error message

udp datagram requires IP address target

What it means

ManagerServerSendTo::send_to was called on a UDP-datagram manager socket with a ManagerSocketAddr::UnixSocketAddr target. UDP sockets can only send to IP:port addresses, so the method refuses the call with ErrorKind::InvalidInput instead of attempting an impossible send.

Solutions

1. Use a SocketAddr (IP:port) target when the manager transport is UDP
2. Switch the manager transport to unix datagram if the manager listens on a unix socket path
3. Validate the ManagerAddr type before choosing which transport/datagram to build

Example fix

// before
udp_conn.send_to(buf, &ManagerSocketAddr::UnixSocketAddr(path)).await?;
// after
let target = ManagerSocketAddr::SocketAddr("127.0.0.1:6010".parse()?);
udp_conn.send_to(buf, &target).await?;

if let ManagerSocketAddr::UnixSocketAddr(_) = target {
    return Err(anyhow!("UDP transport cannot send to unix socket target"));
}

When it happens

Trigger: Calling send_to on a manager connection opened over UDP (ManagerDatagram::UdpDatagram) while passing a target created from a unix socket path (e.g. /path/to/manager.sock).

Common situations: Configuration where the manager address and the transport are mismatched — the client connects to the manager over UDP but the config specifies a unix-socket address, or code copied from the unix-socket variant is reused with a UDP transport.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

• target address must not be unnamed
• unix datagram requires path address target
• AES-128 init
• AES-256 init
• balancer.max_server_rtt must be > 0

AI-assisted analysis of shadowsocks/shadowsocks-rust@8eb0f0a65b (2026-09-09). Data as JSON: /api/errors/1a45b54270f77211. Report an issue: GitHub.

Appendix: source

Thrown at crates/shadowsocks/src/manager/datagram.rs:148

    }

    /// Sends data to the socket
    pub async fn send(&mut self, buf: &[u8]) -> io::Result<usize> {
        match *self {
            Self::UdpDatagram(ref mut udp) => udp.send(buf).await,
            #[cfg(unix)]
            Self::UnixDatagram(ref mut unix) => unix.send(buf).await,
        }
    }

    /// Sends data to the socket to the specified address.
    pub async fn send_to(&mut self, buf: &[u8], target: &ManagerSocketAddr) -> io::Result<usize> {
        match *self {
            Self::UdpDatagram(ref mut udp) => match *target {
                ManagerSocketAddr::SocketAddr(ref saddr) => udp.send_to(buf, saddr).await,
                #[cfg(unix)]
                ManagerSocketAddr::UnixSocketAddr(..) => {
                    let err = io::Error::new(ErrorKind::InvalidInput, "udp datagram requires IP address target");
                    Err(err)
                }
            },
            #[cfg(unix)]
            Self::UnixDatagram(ref mut unix) => match *target {
                ManagerSocketAddr::UnixSocketAddr(ref saddr) => match saddr.as_pathname() {
                    Some(paddr) => unix.send_to(buf, paddr).await,
                    None => {
                        let err = io::Error::new(ErrorKind::InvalidInput, "target address must not be unnamed");
                        Err(err)
                    }
                },
                ManagerSocketAddr::SocketAddr(..) => {
                    let err = io::Error::new(ErrorKind::InvalidInput, "unix datagram requires path address target");
                    Err(err)
                }
            },
        }

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