Crate gbp_stack 

Top-level facade for the Group Protocol Stack.

Most users should depend on this single crate; the layered architecture is an implementation detail that is exposed for users who only need a subset of the stack.

Layers

  ┌────────────────────────────────────────────────────────┐
  │  Layer 4 — orchestration                               │
  │      gbp-node  →  gbp-stack  →  gbp-stack-ffi          │
  ├────────────────────────────────────────────────────────┤
  │  Layer 3 — security & transport                        │
  │      gbp-mls  ·  gbp-transport  ·  gbp-sframe          │
  ├────────────────────────────────────────────────────────┤
  │  Layer 2 — sub-protocols on top of GBP                 │
  │      gtp-protocol · gap-protocol · gsp-protocol        │
  ├────────────────────────────────────────────────────────┤
  │  Layer 1 — base protocol                               │
  │      gbp-protocol (GbpFrame, ControlMessage, …)        │
  ├────────────────────────────────────────────────────────┤
  │  Layer 0 — vocabulary                                  │
  │      gbp-core (StreamType, Flags, FSM, codes)          │
  └────────────────────────────────────────────────────────┘

Re-exports

pub use gap;

pub use gbp;

pub use gbp_core as core;

pub use gbp_mls as mls;

pub use gbp_node as node;

pub use gbp_transport as transport;

pub use gsp;

pub use gtp;

pub use gbp_sframe;

Modules

codes

All canonical error codes.

timeouts

Timeout defaults normative for interoperable deployments (gbp-state-machine §6).

Structs

BoundedSeen

A set with a bounded capacity that evicts the oldest entry on overflow.

CapabilitiesNegotiator

Per-member set of advertised capability tokens.

ControlMessage

Control plane message that travels on Stream 0.

DeliveredPayload

Information about a payload delivered by GBP to a sub-protocol.

ErrorObject

Wire-serialisable error object.

GapClient

Stateful GAP client.

GapPayload

Audio frame payload.

GbpFlags

Bit set on top of u16. Hand-rolled to keep gbp-core free of any dependency tree.

GbpFrame

CBOR-encoded GBP frame.

GroupNode

GBP-layer node.

GspAccept

Accepted signal: decoded fields plus the local state effects already applied by the client.

GspClient

Stateful GSP client.

GspSignal

GSP signal envelope. args carries opcode-specific CBOR bytes.

GtpClient

Stateful GTP client.

GtpMessage

GTP message envelope. Eight CBOR keys.

MlsContext

MLS context for a single group member.

OutboundFrame

A wire-ready outbound frame: the recipient and its serialised CBOR bytes.

SFrameDecryptor

Multi-sender SFrame decryptor for one epoch.

SFrameEncryptor

Stateful per-sender SFrame encryptor.

SFrameHeader

SFrame Key ID helper, backed by sframe’s MlsKeyId (RFC 9605 §5.2).

SFrameSession

An SFrame session bound to one MLS epoch.

Enums

CipherSuite

SFrame ciphersuite selection.

ControlOpcode

Control plane opcode. Width: u16.

ErrorClass

Coarse classification of an error. Single byte on the wire.

Event

Events surfaced by the GBP layer.

GapAccept

Outcome of accepting a GAP payload.

GapError

Errors returned by GapClient.

GspError

Errors returned by GspClient.

GtpAccept

Outcome of accepting a GTP payload.

GtpError

Errors returned by GtpClient.

NodeError

Errors raised by GroupNode.

NodeState

Group node FSM.

PayloadCodec

Codec used to encode the sub-protocol payload inside a GbpFrame.

ProcessedKind

Categorises an MLS message processed via MlsContext::process_message.

SFrameError

Errors that can occur in the SFrame layer.

SignalType

Signal opcode. Allocation: 1xx — membership, 2xx — media permissions, 3xx — stream, 4xx — config.

StreamLabel

Exporter label that binds the AEAD key to a stream class.

StreamType

Stream class. Each StreamType is a separate sub-protocol with its own delivery and reliability policy (see the GBP interop profile).

TransitionState

Epoch transition FSM.

WireError

Errors raised by the transport layer.

Constants

MAX_FRAME

Maximum size of a single on-the-wire message (1 MiB).

Traits

Sealer

Trait abstracting the AEAD seal / open operations.

Functions

label_for

Maps a StreamType to the corresponding StreamLabel.

read_blob

Reads an opaque length-prefixed blob.

read_frame

Reads a GbpFrame using length-prefix + CBOR framing.

write_blob

Writes an opaque length-prefixed blob (e.g. a serialised MLS Welcome or KeyPackage).

write_frame

Writes a GbpFrame using CBOR + length-prefix framing.

Type Aliases

GroupId

Group identifier. On the wire, a 16-byte big-endian unsigned integer.

MemberId

Application-level group member identifier.