Rayhaan JaufeerallyandClaude Fable 5.1
630c175918
The work of the speaker-cleanup branch as one commit; the branch keeps the step-by-step history. Sessions - The state machine is a pure function from events to actions, driven by one task per connection. Idle, Connect and Active belong to a dialer that keeps configured peers up with backoff. - Capabilities are negotiated: address families, four-octet AS numbers with AS_TRANS and AS4_PATH, route refresh, ADD-PATH per family and direction. - Collision detection per RFC 4271 section 6.8, by address and identifier. - Connections are taken only from configured peers, a few per address. - A panic in a session is contained and answered with a Cease; a core task that stops shuts the server down with a Cease to every peer. - Writes that make no progress are given up (RFC 9687). Codec - Malformed UPDATEs are handled as RFC 7606 says: treat-as-withdraw, attribute discard, or session reset, with the NOTIFICATION to send. - Address families are open types; any can be named and ignored. - Prefixes are fixed-size values, normalised, with path identifiers. - Lengths are filled in after writing; one definition of each type code. - Property tests and fuzz targets for every decoder. Routing table - Adj-RIBs-In and Loc-RIB in one sharded table that sessions write to directly. Routes are sixteen bytes; attribute sets are interned in wire form. Best-path selection per RFC 4271 section 9.1.2.2 with deterministic MED. - A journal per shard lets followers read changes at their own pace; one that falls behind is resynchronised. - On a RIPE RIS dump of 148 peers and 39.3M routes: loaded in 2.0 s on 12 cores, about 52 bytes a route. Announcing - Originated routes come from the configuration. Each session has its own exporter with an Adj-RIB-Out, so a slow peer delays only itself. - Routes to a peer in our own AS have an empty path and a LOCAL_PREF. Operations - HTTP status page, JSON API, event stream and Prometheus metrics. - Benchmarks on synthetic and real tables. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2.6 KiB
BGP
This crate provides the bgp binary, which runs the Border Gateway Protocol
daemon together with its read-only HTTP status interface.
cargo run -- path/to/config.textpb
The configuration format is defined in crates/server/proto/config.proto;
testdata/server.textpb is a worked example. The daemon is configured
entirely through that file: peers, and the routes it originates
(originate { prefix: ... }). There is no way to change either at runtime.
When http_endpoint is set the binary also serves:
| Path | Purpose |
|---|---|
GET /statusz |
Status page: configuration, peers and session state, originated and received routes, live event log |
GET /api/status |
Router ID, ASN, uptime and table sizes |
GET /api/config |
The configuration file as read at startup |
GET /api/peers |
Configured peers and established sessions |
GET /api/routes/local |
Originated routes |
GET /api/routes/received |
Adj-RIB-In contents |
GET /api/events |
Server-sent events for session and route changes |
GET /metricz |
Prometheus metrics |
Everything under it is read-only and unauthenticated. Bind it to loopback or put it behind a reverse proxy.
What it does today
It establishes sessions (both dialling configured peers and accepting connections, with RFC 4271 collision detection), announces its originated routes to every peer with itself as next hop, and records what peers send in an Adj-RIB-In. It does not select best paths, re-advertise received routes or program a forwarding table, and it has no import or export policy.
Who may connect
Connections are taken only from the addresses of configured peers, and from
each of those only a few at a time. Anything else is closed unread and
counted in bgp_connections_refused_total. accept_unconfigured_peers: true
lets any host open a session as any AS; it exists for tests on a closed
network.
Trying it without a router
fake_peer is a minimal BGP speaker that connects to the daemon, announces a
prefix, prints every UPDATE it receives and, with --echo, re-announces each
received prefix back with its own ASN prepended (dropping NO_EXPORT routes).
That makes originated prefixes show up in the received table as if they had
travelled through a neighbouring AS:
cargo run -- testdata/server.textpb
cargo run -p bgp-integration-tests --example fake_peer -- \
--server 127.0.0.1:179 --asn 65001 --announce 203.0.113.0/24 --echo
Please refer to the other implementation crates in this repository where most of the actual implementation lives.
Warning: This is still very much a work in progress and is not yet ready for production use.