syntax = "proto3";

package bgp.server;

// Top level BGP Server configuration.
message BgpConfig {
  // The router ID, written as a dotted-quad IPv4 address (e.g. "192.0.2.1").
  // Required even on IPv6-only routers per RFC 4271.
  string router_id = 1;

  // The local 4-byte AS number (RFC 6793).
  uint32 local_asn = 2;

  // Endpoints to accept incoming BGP connections on.
  // Defaults to 0.0.0.0:179 and [::]:179 when empty.
  repeated TcpEndpoint listen_endpoints = 3;

  // Peers configured on this server.
  repeated Peer peers = 4;

  // Limits on routes originated locally (e.g. via the demo UI).
  LocalRoutePolicy local_route_policy = 5;

  // Where to serve the HTTP API, status page and metrics. The port is
  // required. Unset disables the HTTP server.
  TcpEndpoint http_endpoint = 6;

  // Initial delay between attempts to connect to a configured peer, in
  // seconds. Doubles after each failure up to two minutes. Defaults to 5.
  uint32 connect_retry_seconds = 7;

  // Connection collisions (RFC 4271 §6.8) against a session that is already
  // Established are, by default, resolved by closing the new connection.
  // When true they are resolved like any other collision: the connection
  // initiated by the higher BGP Identifier survives, and a second connection
  // opened by the same side replaces the first. This lets a peer that
  // restarted take over from a session we have not yet noticed is dead,
  // instead of being refused until the hold timer expires.
  bool collision_detect_established_state = 8;

  // Watch for pings (ICMPv6 echo requests) sent to the lab prefixes and show
  // them on the status page. Unset disables it.
  PingMonitor ping_monitor = 9;
}

// Shows who is pinging addresses that this host answers for.
//
// The host must already own the addresses, e.g. through an AnyIP route
// ("ip -6 route add local 2001:db8::/40 dev lo"); the kernel keeps answering
// the pings and we only receive a copy. Opening the raw ICMPv6 socket this
// needs takes CAP_NET_RAW on Linux. IPv6 only.
message PingMonitor {
  // Only pings to destinations inside these prefixes are shown. Defaults to
  // the IPv6 prefixes in local_route_policy.allowed_prefixes.
  repeated string prefixes = 1;
}

// Limits on locally originated routes.
message LocalRoutePolicy {
  // A locally originated route is accepted only if it is covered by one of
  // these prefixes, written in CIDR notation (e.g. "10.100.0.0/16").
  // Empty means any prefix may be announced.
  repeated string allowed_prefixes = 1;

  // Maximum number of routes a single owner may announce. 0 means unlimited.
  uint32 max_routes_per_owner = 2;
}

// An IP address and port pair.
message TcpEndpoint {
  // IP address (V4 or V6).
  string address = 1;
  // TCP port. Defaults to 179 for BGP when unset.
  uint32 port = 2;
}

// Configuration of a BGP peer.
message Peer {
  // Human-readable name for logging and diagnostics.
  string name = 1;

  // Address and port to connect to for this peer.
  TcpEndpoint endpoint = 2;

  // The peer's 4-byte AS number (RFC 6793).
  uint32 remote_asn = 3;

  // Hold time to advertise in the OPEN message, in seconds (RFC 4271 §4.2).
  // Must be 0 or >= 3. Defaults to 90 when unset.
  uint32 hold_time_seconds = 4;

  // Source IP address for connections we open to this peer. It is also the
  // next hop of the routes we send it. Required when the peer identifies us
  // by address and the host has several, e.g. when both speakers run on the
  // same machine. Must be the same address family as the endpoint. Unset
  // lets the operating system choose.
  string local_address = 5;
}