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

Decoded SFrame header fields.

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.