prePolicyFilterpath: respect max routes config

pkg/server/peer.go

@@ -104,6 +104,7 @@ type peer struct {
 	policy            *table.RoutingPolicy
 	localRib          *table.TableManager
 	prefixLimitWarned map[bgp.RouteFamily]bool
+	dstRoutesCount    map[bgp.RouteFamily]map[string]uint8
 	llgrEndChs        []chan struct{}
 }
 
@@ -113,6 +114,7 @@ func newPeer(g *oc.Global, conf *oc.Neighbor, loc *table.TableManager, policy *t
 		policy:            policy,
 		fsm:               newFSM(g, conf, logger),
 		prefixLimitWarned: make(map[bgp.RouteFamily]bool),
+		dstRoutesCount:    make(map[bgp.RouteFamily]map[string]uint8),
 	}
 	if peer.isRouteServerClient() {
 		peer.tableId = conf.State.NeighborAddress
@@ -121,6 +123,11 @@ func newPeer(g *oc.Global, conf *oc.Neighbor, loc *table.TableManager, policy *t
 	}
 	rfs, _ := oc.AfiSafis(conf.AfiSafis).ToRfList()
 	peer.adjRibIn = table.NewAdjRib(peer.fsm.logger, rfs)
+	for _, f := range rfs {
+		if peer.isAddPathSendEnabled(f) {
+			peer.dstRoutesCount[f] = make(map[string]uint8)
+		}
+	}
 	return peer
 }
 
@@ -200,6 +207,20 @@ func (peer *peer) isAddPathSendEnabled(family bgp.RouteFamily) bool {
 	return (peer.getAddPathMode(family) & bgp.BGP_ADD_PATH_SEND) > 0
 }
 
+func (peer *peer) getAddPathSendMax(family bgp.RouteFamily) uint8 {
+	peer.fsm.lock.RLock()
+	defer peer.fsm.lock.RUnlock()
+	if !peer.isAddPathSendEnabled(family) {
+		return 0
+	}
+	for _, a := range peer.fsm.pConf.AfiSafis {
+		if a.State.Family == family {
+			return a.AddPaths.Config.SendMax
+		}
+	}
+	return 0
+}
+
 func (peer *peer) isDynamicNeighbor() bool {
 	peer.fsm.lock.RLock()
 	defer peer.fsm.lock.RUnlock()

pkg/server/server.go

@@ -717,6 +717,39 @@ func (s *BgpServer) prePolicyFilterpath(peer *peer, path, old *table.Path) (*tab
 		}
 	}
 
+	if path != nil {
+		family := path.GetRouteFamily()
+		f := func() bgp.RouteFamily {
+			if peerVrf != "" {
+				switch family {
+				case bgp.RF_IPv4_VPN:
+					return bgp.RF_IPv4_UC
+				case bgp.RF_IPv6_VPN:
+					return bgp.RF_IPv6_UC
+				case bgp.RF_FS_IPv4_VPN:
+					return bgp.RF_FS_IPv4_UC
+				case bgp.RF_FS_IPv6_VPN:
+					return bgp.RF_FS_IPv6_UC
+				}
+			}
+			return family
+		}()
+
+		sendMax := peer.getAddPathSendMax(f)
+		if sendMax > 0 {
+			dstPrefix := path.GetNlri().String()
+			dstRouteCount := peer.dstRoutesCount[f][dstPrefix]
+			if dstRouteCount > 0 && path.IsWithdraw {
+				dstRouteCount--
+			} else if dstRouteCount < sendMax && !path.IsWithdraw {
+				dstRouteCount++
+			} else if dstRouteCount >= sendMax {
+				return nil, nil, true
+			}
+			peer.dstRoutesCount[f][dstPrefix] = dstRouteCount
+		}
+	}
+
 	// replace-peer-as handling
 	peer.fsm.lock.RLock()
 	if path != nil && !path.IsWithdraw && peer.fsm.pConf.AsPathOptions.State.ReplacePeerAs {
@@ -760,6 +793,7 @@ func (s *BgpServer) postFilterpath(peer *peer, path *table.Path) *table.Path {
 	if path != nil && !peer.isIBGPPeer() && !peer.isRouteServerClient() {
 		path.RemoveLocalPref()
 	}
+
 	return path
 }
 
@@ -1132,7 +1166,6 @@ func (s *BgpServer) processOutgoingPaths(peer *peer, paths, olds []*table.Path)
 	}
 
 	outgoing := make([]*table.Path, 0, len(paths))
-
 	for idx, path := range paths {
 		var old *table.Path
 		if olds != nil {