Crate srt_runtime 

srt-runtime — SRT (Secure Reliable Transport) packet codecs.

Spec grounding: draft-sharabayko-srt-01 (free, redistributable IETF Internet-Draft), vendored at specs/ietf_draft_sharabayko_srt_01.txt; the curated field tables this crate implements against live in specs/rules/srt-rules.md.

Scope of this release

This is the packet codec deliverable only: typed, byte-exact parse/serialize for every packet type in §3 (Packet Structure) — the 16-byte SRT header, the data packet (§3.1), and every control packet type (§3.2): Handshake (with its extension messages: Handshake Extension, §3.2.1.1; Key Material, §3.2.1.2/§3.2.2; Stream ID, §3.2.1.3; Group Membership, §3.2.1.4), Keep-Alive, ACK, NAK, Congestion Warning, Shutdown, ACKACK, Message Drop Request, and Peer Error.

Explicit follow-ups, not attempted here:

• The handshake state machine (caller/listener/rendezvous exchange, §4.3) — this crate parses/builds handshake packets, not a connection.
• ARQ / loss handling, TSBPD, congestion control (§4-§5).
• Actual AES key-wrap/unwrap crypto (§6) — packet::KeyMaterial carries the wrapped-key bytes opaquely.
• A tokio socket adapter (mirroring rtsp-runtime’s io module).

The sans-IO contract

No sockets, no state machine: packet::SrtPacket::parse takes the bytes of one UDP datagram and returns a typed packet; the packet’s serialize_into writes it back out. Everything here is a pure, allocating (but not I/O-performing) parse/serialize pair.

Reserved-bit policy

Fields the spec documents as fixed-value or reserved-for-future-use (Subtype on every Control Type except User-Defined; the header Type-specific Information word where a packet type does not use it; the Key Material message’s S/V/PT/Sign/Resv1/Resv2/Resv3 fields) are validated against their spec-mandated value on parse and are not stored in the typed structs — they are reconstructed on serialize. A non-compliant value is a structured error::Error, never a panic.

Module map

• packet — packet::SrtPacket, the data/control packet types, and their sub-structures (handshake extensions, Key Material, ACK variants, NAK loss-list coding).
• error — the Error enum and Result alias.

Re-exports

pub use error::Error;

pub use error::Result;

pub use packet::SrtPacket;

Modules

error

Error type for SRT packet parsing and serialization.

packet

SRT packet structure — draft-sharabayko-srt-01 §3 (Packet Structure).

Constants

SPEC

The Internet-Draft this crate implements packet structure from.