rust-ethernet-ip-protocol

EtherNet/IP wire-protocol codecs for the rust-ethernet-ip ecosystem.

Pure encode/decode boundary for the EtherNet/IP encapsulation header, CIP framing, CPF items, and PLC value serialization. Operates only on bytes::BytesMut / &[u8] — no I/O, no async, no client state.

Submodules:

• encap — EtherNet/IP encapsulation header (SendRRData, RegisterSession, ListIdentity, etc.)
• cip — CIP Connection Manager framing (CipRequest, CipResponse, SendDataRequest, CpfItem)
• values — PlcValue encode/decode and BOOL-array DWORD packing helpers

Public traits:

• Encode — infallible fn encode(&self, &mut BytesMut)
• Decode — fn decode(buf: &mut impl Buf) -> Result<Self>

Who should use this crate

Most consumers want the top-level rust-ethernet-ip crate.

Depend on rust-ethernet-ip-protocol directly only if you are building an alternative network layer (UDP discovery, custom connection management, packet replay tooling, etc.) and want the wire codecs without the rest of the client.

Hardened against silent failures

• CipRequest::encode returns Result and validates empty paths, odd-length paths, and paths beyond the 510-byte CIP limit before writing any bytes
• Pinned-byte tests cover AB STRING padding, UDT type-tag synthesis, CIP error responses, and route-path encoding

License

MIT. Part of the rust-ethernet-ip workspace.