rustbgpd-wire

BGP message codec for Rust. Encode and decode OPEN, UPDATE, KEEPALIVE, NOTIFICATION, and ROUTE-REFRESH messages per RFC 4271, with extensions for MP-BGP, EVPN, FlowSpec, Add-Path, Extended Messages, and more.

This crate is the wire-protocol foundation of rustbgpd but is designed for standalone use in any Rust project that needs to parse or build BGP messages — monitors, analyzers, test harnesses, MRT readers, etc.

Supported RFCs

RFC	Feature
1997	Standard communities (4-byte)
2545	IPv6 link-local next-hop in `MP_REACH_NLRI` (32-byte form)
2918	Route Refresh capability
4271	BGP-4 core: OPEN, UPDATE, NOTIFICATION, KEEPALIVE
4360	Extended communities (route target, route origin, 4-byte AS)
4456	Route reflector: ORIGINATOR_ID, CLUSTER_LIST
4486	NOTIFICATION subcodes
4724	Graceful restart capability
4760	MP-BGP: `MP_REACH_NLRI` / `MP_UNREACH_NLRI`
5492	BGP capabilities
6793	4-octet AS numbers
7313	Enhanced Route Refresh (BoRR / EoRR markers)
7432	EVPN: Types 1–4 (EAD, MAC/IP, IMET, Ethernet Segment)
7674	Clarification of MP_REACH_NLRI next-hop encoding
7911	Add-Path: path ID in NLRI encode/decode
8092	Large communities (3× u32)
8203	Admin shutdown communication
8365	EVPN over VXLAN encapsulation
8538	Notification GR (N-bit)
8654	Extended messages (up to 65535 bytes)
8950	Extended next hop (IPv4 NLRI over IPv6 NH)
8955/8956	FlowSpec: 13 component types, numeric/bitmask operators; §6.1-compliant `NEXT_HOP` validation (the irrelevant-next-hop case is accepted, not rejected)
9012	Tunnel Encapsulation attribute
9135	EVPN integrated routing for IRB
9136	EVPN Type 5: IP Prefix advertisement
9494	Long-lived graceful restart capability

Usage

Parse an UPDATE from raw bytes:

use bytes::Bytes;
use rustbgpd_wire::{UpdateMessage, Afi, Safi};

let raw = Bytes::from(update_bytes);
let update = UpdateMessage::decode(&mut raw.clone(), raw.len())?;
let parsed = update.parse(
    true,   // 4-octet AS numbers
    false,  // no Add-Path on body NLRI
    &[],    // no Add-Path families for MP NLRI
)?;

for route in &parsed.announced {
    println!("announced: {}", route.prefix);
}
for attr in &parsed.attributes {
    println!("attribute: {:?}", attr);
}

Build and encode an OPEN message:

use rustbgpd_wire::{Message, open::OpenMessage, capability::Capability};

let open = OpenMessage {
    version: 4,
    my_as: 65000,
    hold_time: 90,
    bgp_id: [10, 0, 0, 1],
    capabilities: vec![
        Capability::FourOctetAs(65000),
        Capability::MultiProtocol { afi: 1, safi: 1 },
    ],
};
let msg = Message::Open(open);
let bytes = rustbgpd_wire::encode_message(&msg);

Key types

Message — top-level enum: Open, Update, Keepalive, Notification, RouteRefresh
UpdateMessage / ParsedUpdate — raw wire form and parsed routes + attributes
PathAttribute — 18+ attribute types including AsPath, NextHop, Communities, MpReachNlri, LargeCommunities
Prefix — V4(Ipv4Prefix) / V6(Ipv6Prefix) enum
Capability — OPEN capabilities: multi-protocol, 4-octet AS, Add-Path, graceful restart, etc.
FlowSpecRule / FlowSpecComponent — FlowSpec NLRI with all 13 match types
EvpnRoute / EvpnRouteKey — typed EVPN routes (Types 1–5) with full payloads (RFC 7432, RFC 9136)
DecodeError / EncodeError — structured error types via thiserror

Fuzz tested

Three fuzz targets exercise the decode paths continuously in CI:

decode_message — full BGP message framing
decode_update — UPDATE parsing with Add-Path and MP-BGP variants
decode_flowspec — FlowSpec NLRI component decoding

License