From 4770c95ed6b7f0d675473586b6712ca03f20aca7 Mon Sep 17 00:00:00 2001
From: Sebastian Lohff <seba@someserver.de>
Date: Sun, 24 May 2020 18:53:00 +0200
Subject: [PATCH] Add method to get BMP Neighbors as API Session objects

This method can be used to expose a BGPServer-like API with a BMP server
as backend.
---
 protocols/bgp/server/bmp_router.go | 43 ++++++++++++++++++++++++++++++
 protocols/bgp/server/fsm.go        | 22 +++++++++++++++
 2 files changed, 65 insertions(+)

diff --git a/protocols/bgp/server/bmp_router.go b/protocols/bgp/server/bmp_router.go
index 490c8b01..330b6b87 100644
--- a/protocols/bgp/server/bmp_router.go
+++ b/protocols/bgp/server/bmp_router.go
@@ -12,6 +12,7 @@ import (
 	log "github.com/sirupsen/logrus"
 
 	bnet "github.com/bio-routing/bio-rd/net"
+	"github.com/bio-routing/bio-rd/protocols/bgp/api"
 	"github.com/bio-routing/bio-rd/protocols/bgp/packet"
 	bmppkt "github.com/bio-routing/bio-rd/protocols/bmp/packet"
 	"github.com/bio-routing/bio-rd/routingtable"
@@ -128,6 +129,48 @@ func (r *Router) serve(con net.Conn) {
 	}
 }
 
+// GetNeighborSessions returns all neighbors as API session objects
+func (r *Router) GetNeighborSessions() []*api.Session {
+	sessions := make([]*api.Session, 0)
+
+	for _, neigh := range r.neighborManager.list() {
+		estSince := neigh.fsm.establishedTime.Unix()
+		if estSince < 0 {
+			estSince = 0
+		}
+
+		// for now get this from adjRibIn/adjRibOut, can be replaced when we
+		// bmp gets its own bgpSrv or Router gets the bmpMetricsService
+		var routesReceived, routesSent uint64
+		for _, afi := range []uint16{packet.IPv4AFI, packet.IPv6AFI} {
+			ribIn, err1 := r.GetNeighborRIBIn(neigh.fsm.peer.addr, afi, packet.UnicastSAFI)
+			if err1 == nil {
+				routesReceived += uint64(ribIn.RouteCount())
+			}
+
+			// adjRIBOut might not work properly with BMP, keeping it here for when it will
+			ribOut, err2 := r.GetNeighborRIBOut(neigh.fsm.peer.addr, afi, packet.UnicastSAFI)
+			if err2 == nil {
+				routesSent += uint64(ribOut.RouteCount())
+			}
+		}
+		session := &api.Session{
+			LocalAddress:    neigh.fsm.peer.localAddr.ToProto(),
+			NeighborAddress: neigh.fsm.peer.addr.ToProto(),
+			LocalAsn:        neigh.localAS,
+			PeerAsn:         neigh.peerAS,
+			Status:          stateToProto(neigh.fsm.state),
+			Stats: &api.SessionStats{
+				RoutesReceived: routesReceived,
+				RoutesExported: routesSent,
+			},
+			EstablishedSince: uint64(estSince),
+		}
+		sessions = append(sessions, session)
+	}
+	return sessions
+}
+
 func (r *Router) processMsg(msg []byte) {
 	bmpMsg, err := bmppkt.Decode(msg)
 	if err != nil {
diff --git a/protocols/bgp/server/fsm.go b/protocols/bgp/server/fsm.go
index 18017bbb..26f5daff 100644
--- a/protocols/bgp/server/fsm.go
+++ b/protocols/bgp/server/fsm.go
@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"github.com/bio-routing/bio-rd/net/tcp"
+	"github.com/bio-routing/bio-rd/protocols/bgp/api"
 	"github.com/bio-routing/bio-rd/protocols/bgp/packet"
 	"github.com/bio-routing/bio-rd/routingtable/filter"
 	"github.com/pkg/errors"
@@ -239,6 +240,27 @@ func stateName(s state) string {
 	}
 }
 
+func stateToProto(s state) api.Session_State {
+	switch s.(type) {
+	case *idleState:
+		return api.Session_Idle
+	case *connectState:
+		return api.Session_Connect
+	case *activeState:
+		return api.Session_Active
+	case *openSentState:
+		return api.Session_OpenSent
+	case *openConfirmState:
+		return api.Session_OpenConfirmed
+	case *establishedState:
+		return api.Session_Established
+	case *ceaseState:
+		return api.Session_Active // substitution
+	default:
+		panic(fmt.Sprintf("Unknown state: %v", s))
+	}
+}
+
 func (fsm *FSM) cease() {
 	fsm.eventCh <- Cease
 }