Crate umsh_core 

Core wire-format types and packet construction/parsing utilities for UMSH.

Note: This reference implementation is a work in progress and was developed with the assistance of an LLM. It should be considered experimental.

This crate stays focused on byte layout, typed header fields, and zero-copy parsing. It does not perform any cryptographic operations or I/O.

The main entry points are:

• PacketHeader::parse to inspect a received frame.
• PacketBuilder to construct outbound frames with typestate guards.
• feed_aad to stream canonical authenticated data into a MAC state.
• options::OptionEncoder and options::OptionDecoder for CoAP-style option blocks used throughout the protocol.

Example

use umsh_core::{MicSize, NodeHint, PacketBuilder, PacketHeader, PublicKey};

let mut buf = [0u8; 128];
let src = PublicKey([0x11; 32]);
let dst = NodeHint([0xAA, 0xBB, 0xCC]);

let packet = PacketBuilder::new(&mut buf)
    .unicast(dst)
    .source_full(&src)
    .frame_counter(7)
    .encrypted()
    .mic_size(MicSize::Mic16)
    .payload(b"hello")
    .build()
    .unwrap();

let header = PacketHeader::parse(packet.as_bytes()).unwrap();
assert_eq!(header.dst, Some(dst));
assert_eq!(header.body_range.len(), 5);

Modules

options

state

Typestate markers used by PacketBuilder and its specialized builders.

Structs

ChannelId

Two-byte multicast channel identifier.

ChannelKey

Raw 32-byte multicast channel secret.

Fcf

Frame-control field wrapper.

FloodHops

Combined remaining/accumulated flood-hop counters.

NodeHint

Three-byte node hint derived from a public key.

PacketBuilder

Entry point for typestate packet construction.

PacketHeader

Parsed packet header with borrowed ranges into the original frame.

ParsedOptions

PublicKey

Node public key, which also acts as the full network address.

RouterHint

Two-byte router hint used in learned routes.

Scf

Security-control field wrapper.

SecInfo

Decoded SECINFO structure.

UnsealedPacket

Enums

BuildError

Errors returned while assembling a full packet with crate::PacketBuilder.

EncodeError

Errors returned while encoding wire-format values into caller-provided buffers.

MicSize

Authenticator size carried by secured packets.

OptionNumber

Known packet-option numbers.

PacketType

Packet class encoded in the frame-control field.

ParseError

Errors returned while parsing on-wire UMSH structures.

PayloadType

Application payload type carried inside the MAC body.

SourceAddr

Source address supplied while constructing packets.

SourceAddrRef

Parsed source-address location used by zero-copy packet processing.

Constants

UMSH_VERSION

Current UMSH packet version encoded in the FCF high bits.

Functions

feed_aad

iter_options

Type Aliases

BlindUnicastBuilder

Blind-unicast packet builder alias.

BroadcastBuilder

Broadcast packet builder alias.

MacAckBuilder

MAC ACK packet builder alias.

MulticastBuilder

Multicast packet builder alias.

UnicastBuilder

Unicast packet builder alias.