rw_core/route/device_route.go - voltha-go - Gitiles

 /*
  * Copyright 2020-present Open Networking Foundation
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  * http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */

 package route

 import (
 	"context"
 	"fmt"
 	"github.com/opencord/voltha-lib-go/v3/pkg/log"
 	"github.com/opencord/voltha-protos/v3/go/voltha"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 	"sync"
 )

 func init() {
 	_, err := log.AddPackage(log.JSON, log.WarnLevel, nil)
 	if err != nil {
 		log.Fatalw("unable-to-register-package-to-the-log-map", log.Fields{"error": err})
 	}
 }

 // Hop represent a route hop
 type Hop struct {
 	DeviceID string
 	Ingress  uint32
 	Egress   uint32
 }

 // PathID is the identification of a route between two logical ports
 type PathID struct {
 	Ingress uint32
 	Egress  uint32
 }

 type OFPortLink struct {
 	Ingress uint32
 	Egress  uint32
 }

 // GetDeviceFunc returns device function
 type GetDeviceFunc func(ctx context.Context, id string) (*voltha.Device, error)

 // DeviceRoutes represent the set of routes between logical ports of a logical device
 type DeviceRoutes struct {
 	logicalDeviceID     string
 	getDeviceFromModel  GetDeviceFunc
 	logicalPorts        []*voltha.LogicalPort
 	RootPorts           map[uint32]uint32
 	rootPortsLock       sync.RWMutex
 	Routes              map[PathID][]Hop
 	routeBuildLock      sync.RWMutex
 	devicesPonPorts     map[string][]*voltha.Port
 	devicesPonPortsLock sync.RWMutex
 }

 // NewDeviceRoutes creates device graph instance
 func NewDeviceRoutes(logicalDeviceID string, getDevice GetDeviceFunc) *DeviceRoutes {
 	var dr DeviceRoutes
 	dr.logicalDeviceID = logicalDeviceID
 	dr.getDeviceFromModel = getDevice
 	dr.RootPorts = make(map[uint32]uint32)
 	dr.Routes = make(map[PathID][]Hop)
 	dr.devicesPonPorts = make(map[string][]*voltha.Port)
 	log.Debug("new device routes created ...")
 	return &dr
 }

 //IsRootPort returns true if the port is a root port on a logical device
 func (dr *DeviceRoutes) IsRootPort(port uint32) bool {
 	dr.rootPortsLock.RLock()
 	defer dr.rootPortsLock.RUnlock()
 	_, exist := dr.RootPorts[port]
 	return exist
 }

 //ComputeRoutes calculates all the routes between the logical ports.  This will clear up any existing route
 func (dr *DeviceRoutes) ComputeRoutes(ctx context.Context, lps []*voltha.LogicalPort) error {
 	dr.routeBuildLock.Lock()
 	defer dr.routeBuildLock.Unlock()

 	log.Debugw("computing-all-routes", log.Fields{"len-logical-ports": len(lps)})
 	var err error
 	defer func() {
 		// On error, clear the routes - any flow request or a port add/delete will trigger the rebuild
 		if err != nil {
 			dr.reset()
 		}
 	}()

 	if len(lps) < 2 {
 		return status.Error(codes.FailedPrecondition, "not-enough-logical-ports")
 	}

 	dr.reset()
 	dr.logicalPorts = append(dr.logicalPorts, lps...)

 	// Setup the physical ports to logical ports map, the nni ports as well as the root ports map
 	physPortToLogicalPortMap := make(map[string]uint32)
 	nniPorts := make([]*voltha.LogicalPort, 0)
 	for _, lp := range lps {
 		physPortToLogicalPortMap[concatDeviceIDPortID(lp.DeviceId, lp.DevicePortNo)] = lp.OfpPort.PortNo
 		if lp.RootPort {
 			nniPorts = append(nniPorts, lp)
 			dr.RootPorts[lp.OfpPort.PortNo] = lp.OfpPort.PortNo
 		}
 	}
 	if len(nniPorts) == 0 {
 		err = status.Error(codes.FailedPrecondition, "no nni port")
 		return err
 	}
 	var rootDevice *voltha.Device
 	var childDevice *voltha.Device
 	var copyFromNNIPort *voltha.LogicalPort
 	for idx, nniPort := range nniPorts {
 		if idx == 0 {
 			copyFromNNIPort = nniPort
 		} else if len(dr.Routes) > 0 {
 			dr.copyFromExistingNNIRoutes(nniPort, copyFromNNIPort)
 			return nil
 		}
 		// Get root device
 		rootDevice, err = dr.getDevice(ctx, nniPort.DeviceId)
 		if err != nil {
 			return err
 		}
 		if len(rootDevice.Ports) == 0 {
 			err = status.Errorf(codes.FailedPrecondition, "no-port-%s", rootDevice.Id)
 			return err
 		}
 		for _, rootDevicePort := range rootDevice.Ports {
 			if rootDevicePort.Type == voltha.Port_PON_OLT {
 				log.Debugw("peers", log.Fields{"root-device-id": rootDevice.Id, "port-no": rootDevicePort.PortNo, "len-peers": len(rootDevicePort.Peers)})
 				for _, rootDevicePeer := range rootDevicePort.Peers {
 					childDevice, err = dr.getDevice(ctx, rootDevicePeer.DeviceId)
 					if err != nil {
 						return err
 					}
 					childPonPorts := dr.getDevicePonPorts(childDevice.Id, nniPort.DeviceId)
 					if len(childPonPorts) < 1 {
 						err = status.Errorf(codes.Aborted, "no-child-pon-port-%s", childDevice.Id)
 						return err
 					}
 					// We use the first PON port on the ONU whose parent is the root device.
 					childPonPort := childPonPorts[0].PortNo
 					for _, childDevicePort := range childDevice.Ports {
 						if childDevicePort.Type == voltha.Port_ETHERNET_UNI {
 							childLogicalPort, exist := physPortToLogicalPortMap[concatDeviceIDPortID(childDevice.Id, childDevicePort.PortNo)]
 							if !exist {
 								// This can happen if this logical port has not been created yet for that device
 								continue
 							}
 							dr.Routes[PathID{Ingress: nniPort.OfpPort.PortNo, Egress: childLogicalPort}] = []Hop{
 								{DeviceID: rootDevice.Id, Ingress: nniPort.DevicePortNo, Egress: rootDevicePort.PortNo},
 								{DeviceID: childDevice.Id, Ingress: childPonPort, Egress: childDevicePort.PortNo},
 							}
 							dr.Routes[PathID{Ingress: childLogicalPort, Egress: nniPort.OfpPort.PortNo}] = getReverseRoute(
 								dr.Routes[PathID{Ingress: nniPort.OfpPort.PortNo, Egress: childLogicalPort}])
 						}
 					}
 				}
 			}
 		}
 	}
 	return nil
 }

 // verifyPrecondition verify whether the preconditions are met to proceed with addition of the new logical port
 func (dr *DeviceRoutes) addPortAndVerifyPrecondition(lp *voltha.LogicalPort) error {
 	var exist, nniLogicalPortExist, uniLogicalPortExist bool
 	for _, existingLogicalPort := range dr.logicalPorts {
 		nniLogicalPortExist = nniLogicalPortExist || existingLogicalPort.RootPort
 		uniLogicalPortExist = uniLogicalPortExist || !existingLogicalPort.RootPort
 		exist = exist || existingLogicalPort.OfpPort.PortNo == lp.OfpPort.PortNo
 		if nniLogicalPortExist && uniLogicalPortExist && exist {
 			break
 		}
 	}
 	if !exist {
 		dr.logicalPorts = append(dr.logicalPorts, lp)
 		nniLogicalPortExist = nniLogicalPortExist || lp.RootPort
 		uniLogicalPortExist = uniLogicalPortExist || !lp.RootPort
 	}

 	// If we do not have both NNI and UNI ports then return an error
 	if !(nniLogicalPortExist && uniLogicalPortExist) {
 		fmt.Println("errors", nniLogicalPortExist, uniLogicalPortExist)
 		return status.Error(codes.FailedPrecondition, "no-uni-and-nni-ports-combination")
 	}
 	return nil
 }

 // AddPort augments the current set of routes with new routes corresponding to the logical port "lp".  If the routes have
 // not been built yet then use logical port "lps" to compute all current routes (lps includes lp)
 func (dr *DeviceRoutes) AddPort(ctx context.Context, lp *voltha.LogicalPort, lps []*voltha.LogicalPort) error {
 	log.Debugw("add-port-to-routes", log.Fields{"port": lp, "len-logical-ports": len(lps)})

 	dr.routeBuildLock.Lock()
 	if len(dr.Routes) == 0 {
 		dr.routeBuildLock.Unlock()
 		return dr.ComputeRoutes(ctx, lps)
 	}

 	// A set of routes exists
 	if err := dr.addPortAndVerifyPrecondition(lp); err != nil {
 		dr.reset()
 		dr.routeBuildLock.Unlock()
 		return err
 	}

 	defer dr.routeBuildLock.Unlock()
 	// Update the set of root ports, if applicable
 	if lp.RootPort {
 		dr.RootPorts[lp.OfpPort.PortNo] = lp.OfpPort.PortNo
 	}

 	var copyFromNNIPort *voltha.LogicalPort
 	// Setup the physical ports to logical ports map
 	nniPorts := make([]*voltha.LogicalPort, 0)
 	for _, lport := range dr.logicalPorts {
 		if lport.RootPort {
 			nniPorts = append(nniPorts, lport)
 			if copyFromNNIPort == nil && lport.OfpPort.PortNo != lp.OfpPort.PortNo {
 				copyFromNNIPort = lport
 			}
 		}
 	}

 	if copyFromNNIPort == nil {
 		// Trying to add the same NNI port.  Just return
 		return nil
 	}

 	// Adding NNI Port?   If we are here we already have an NNI port with a set of routes.  Just copy the existing
 	// routes using an existing NNI port
 	if lp.RootPort {
 		dr.copyFromExistingNNIRoutes(lp, copyFromNNIPort)
 		return nil
 	}

 	// Adding a UNI port
 	for _, nniPort := range nniPorts {
 		childPonPorts := dr.getDevicePonPorts(lp.DeviceId, nniPort.DeviceId)
 		if len(childPonPorts) == 0 || len(childPonPorts[0].Peers) == 0 {
 			// Ports may not have been cached yet - get the device info which sets the PON port cache
 			if _, err := dr.getDevice(ctx, lp.DeviceId); err != nil {
 				dr.reset()
 				return err
 			}
 			childPonPorts = dr.getDevicePonPorts(lp.DeviceId, nniPort.DeviceId)
 			if len(childPonPorts) == 0 || len(childPonPorts[0].Peers) == 0 {
 				dr.reset()
 				return status.Errorf(codes.FailedPrecondition, "no-pon-ports-%s", lp.DeviceId)
 			}
 		}
 		// We use the first PON port on the child device
 		childPonPort := childPonPorts[0]
 		dr.Routes[PathID{Ingress: nniPort.OfpPort.PortNo, Egress: lp.OfpPort.PortNo}] = []Hop{
 			{DeviceID: nniPort.DeviceId, Ingress: nniPort.DevicePortNo, Egress: childPonPort.Peers[0].PortNo},
 			{DeviceID: lp.DeviceId, Ingress: childPonPort.PortNo, Egress: lp.DevicePortNo},
 		}
 		dr.Routes[PathID{Ingress: lp.OfpPort.PortNo, Egress: nniPort.OfpPort.PortNo}] = getReverseRoute(
 			dr.Routes[PathID{Ingress: nniPort.OfpPort.PortNo, Egress: lp.OfpPort.PortNo}])
 	}
 	return nil
 }

 // Print prints routes
 func (dr *DeviceRoutes) Print() error {
 	log.Debugw("Print", log.Fields{"logical-device-id": dr.logicalDeviceID, "logical-ports": dr.logicalPorts})
 	if log.V(log.DebugLevel) {
 		output := ""
 		routeNumber := 1
 		for k, v := range dr.Routes {
 			key := fmt.Sprintf("LP:%d->LP:%d", k.Ingress, k.Egress)
 			val := ""
 			for _, i := range v {
 				val += fmt.Sprintf("{%d->%s->%d},", i.Ingress, i.DeviceID, i.Egress)
 			}
 			val = val[:len(val)-1]
 			output += fmt.Sprintf("%d:{%s=>%s}   ", routeNumber, key, fmt.Sprintf("[%s]", val))
 			routeNumber++
 		}
 		if len(dr.Routes) == 0 {
 			log.Debugw("no-routes-found", log.Fields{"logical-device-id": dr.logicalDeviceID})
 		} else {
 			log.Debugw("graph_routes", log.Fields{"lDeviceId": dr.logicalDeviceID, "Routes": output})
 		}
 	}
 	return nil
 }

 // IsUpToDate returns true if device is up to date
 func (dr *DeviceRoutes) IsUpToDate(ld *voltha.LogicalDevice) bool {
 	dr.routeBuildLock.Lock()
 	defer dr.routeBuildLock.Unlock()
 	numNNI, numUNI := 0, 0
 	if ld != nil {
 		if len(dr.logicalPorts) != len(ld.Ports) {
 			return false
 		}
 		numNNI = len(dr.RootPorts)
 		numUNI = len(ld.Ports) - numNNI
 	}
 	return len(dr.Routes) == numNNI*numUNI*2
 }

 // getDevicePonPorts returns all the PON ports of a device whose peer device ID is peerDeviceID
 func (dr *DeviceRoutes) getDevicePonPorts(deviceID string, peerDeviceID string) []*voltha.Port {
 	dr.devicesPonPortsLock.RLock()
 	defer dr.devicesPonPortsLock.RUnlock()
 	ponPorts := make([]*voltha.Port, 0)
 	ports, exist := dr.devicesPonPorts[deviceID]
 	if !exist {
 		return ponPorts
 	}
 	//fmt.Println("getDevicePonPorts", deviceID, peerDeviceID, ports)
 	for _, port := range ports {
 		for _, peer := range port.Peers {
 			if peer.DeviceId == peerDeviceID {
 				ponPorts = append(ponPorts, port)
 			}
 		}
 	}
 	return ponPorts
 }

 //getDevice returns the from the model and updates the PON ports map of that device.
 func (dr *DeviceRoutes) getDevice(ctx context.Context, deviceID string) (*voltha.Device, error) {
 	device, err := dr.getDeviceFromModel(ctx, deviceID)
 	if err != nil {
 		log.Errorw("device-not-found", log.Fields{"deviceId": deviceID, "error": err})
 		return nil, err
 	}
 	dr.devicesPonPortsLock.Lock()
 	defer dr.devicesPonPortsLock.Unlock()
 	for _, port := range device.Ports {
 		if port.Type == voltha.Port_PON_ONU || port.Type == voltha.Port_PON_OLT {
 			dr.devicesPonPorts[device.Id] = append(dr.devicesPonPorts[device.Id], port)
 		}
 	}
 	return device, nil
 }

 //copyFromExistingNNIRoutes copies routes from an existing set of NNI routes
 func (dr *DeviceRoutes) copyFromExistingNNIRoutes(newNNIPort *voltha.LogicalPort, copyFromNNIPort *voltha.LogicalPort) {
 	updatedRoutes := make(map[PathID][]Hop)
 	for key, val := range dr.Routes {
 		if key.Ingress == copyFromNNIPort.OfpPort.PortNo {
 			updatedRoutes[PathID{Ingress: newNNIPort.OfpPort.PortNo, Egress: key.Egress}] = []Hop{
 				{DeviceID: newNNIPort.DeviceId, Ingress: newNNIPort.DevicePortNo, Egress: val[0].Egress},
 				val[1],
 			}
 		}
 		if key.Egress == copyFromNNIPort.OfpPort.PortNo {
 			updatedRoutes[PathID{Ingress: key.Ingress, Egress: newNNIPort.OfpPort.PortNo}] = []Hop{
 				val[0],
 				{DeviceID: newNNIPort.DeviceId, Ingress: val[1].Ingress, Egress: newNNIPort.DevicePortNo},
 			}
 		}
 		updatedRoutes[key] = val
 	}
 	dr.Routes = updatedRoutes
 }

 // reset cleans up the device graph
 func (dr *DeviceRoutes) reset() {
 	dr.rootPortsLock.Lock()
 	dr.RootPorts = make(map[uint32]uint32)
 	dr.rootPortsLock.Unlock()
 	// Do not numGetDeviceCalledLock Routes, logicalPorts  as the callee function already holds its numGetDeviceCalledLock.
 	dr.Routes = make(map[PathID][]Hop)
 	dr.logicalPorts = make([]*voltha.LogicalPort, 0)
 	dr.devicesPonPortsLock.Lock()
 	dr.devicesPonPorts = make(map[string][]*voltha.Port)
 	dr.devicesPonPortsLock.Unlock()
 }

 //concatDeviceIdPortId formats a portid using the device id and the port number
 func concatDeviceIDPortID(deviceID string, portNo uint32) string {
 	return fmt.Sprintf("%s:%d", deviceID, portNo)
 }

 //getReverseRoute returns the reverse of the route
 func getReverseRoute(route []Hop) []Hop {
 	reverse := make([]Hop, len(route))
 	for i, j := 0, len(route)-1; j >= 0; i, j = i+1, j-1 {
 		reverse[i].DeviceID, reverse[i].Ingress, reverse[i].Egress = route[j].DeviceID, route[j].Egress, route[j].Ingress
 	}
 	return reverse
 }
	/*
	* Copyright 2020-present Open Networking Foundation
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package route

	import (
	"context"
	"fmt"
	"github.com/opencord/voltha-lib-go/v3/pkg/log"
	"github.com/opencord/voltha-protos/v3/go/voltha"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"
	"sync"
	)

	func init() {
	_, err := log.AddPackage(log.JSON, log.WarnLevel, nil)
	if err != nil {
	log.Fatalw("unable-to-register-package-to-the-log-map", log.Fields{"error": err})
	}
	}

	// Hop represent a route hop
	type Hop struct {
	DeviceID string
	Ingress uint32
	Egress uint32
	}

	// PathID is the identification of a route between two logical ports
	type PathID struct {
	Ingress uint32
	Egress uint32
	}

	type OFPortLink struct {
	Ingress uint32
	Egress uint32
	}

	// GetDeviceFunc returns device function
	type GetDeviceFunc func(ctx context.Context, id string) (*voltha.Device, error)

	// DeviceRoutes represent the set of routes between logical ports of a logical device
	type DeviceRoutes struct {
	logicalDeviceID string
	getDeviceFromModel GetDeviceFunc
	logicalPorts []*voltha.LogicalPort
	RootPorts map[uint32]uint32
	rootPortsLock sync.RWMutex
	Routes map[PathID][]Hop
	routeBuildLock sync.RWMutex
	devicesPonPorts map[string][]*voltha.Port
	devicesPonPortsLock sync.RWMutex
	}

	// NewDeviceRoutes creates device graph instance
	func NewDeviceRoutes(logicalDeviceID string, getDevice GetDeviceFunc) *DeviceRoutes {
	var dr DeviceRoutes
	dr.logicalDeviceID = logicalDeviceID
	dr.getDeviceFromModel = getDevice
	dr.RootPorts = make(map[uint32]uint32)
	dr.Routes = make(map[PathID][]Hop)
	dr.devicesPonPorts = make(map[string][]*voltha.Port)
	log.Debug("new device routes created ...")
	return &dr
	}

	//IsRootPort returns true if the port is a root port on a logical device
	func (dr *DeviceRoutes) IsRootPort(port uint32) bool {
	dr.rootPortsLock.RLock()
	defer dr.rootPortsLock.RUnlock()
	_, exist := dr.RootPorts[port]
	return exist
	}

	//ComputeRoutes calculates all the routes between the logical ports. This will clear up any existing route
	func (dr DeviceRoutes) ComputeRoutes(ctx context.Context, lps []voltha.LogicalPort) error {
	dr.routeBuildLock.Lock()
	defer dr.routeBuildLock.Unlock()

	log.Debugw("computing-all-routes", log.Fields{"len-logical-ports": len(lps)})
	var err error
	defer func() {
	// On error, clear the routes - any flow request or a port add/delete will trigger the rebuild
	if err != nil {
	dr.reset()
	}
	}()

	if len(lps) < 2 {
	return status.Error(codes.FailedPrecondition, "not-enough-logical-ports")
	}

	dr.reset()
	dr.logicalPorts = append(dr.logicalPorts, lps...)

	// Setup the physical ports to logical ports map, the nni ports as well as the root ports map
	physPortToLogicalPortMap := make(map[string]uint32)
	nniPorts := make([]*voltha.LogicalPort, 0)
	for _, lp := range lps {
	physPortToLogicalPortMap[concatDeviceIDPortID(lp.DeviceId, lp.DevicePortNo)] = lp.OfpPort.PortNo
	if lp.RootPort {
	nniPorts = append(nniPorts, lp)
	dr.RootPorts[lp.OfpPort.PortNo] = lp.OfpPort.PortNo
	}
	}
	if len(nniPorts) == 0 {
	err = status.Error(codes.FailedPrecondition, "no nni port")
	return err
	}
	var rootDevice *voltha.Device
	var childDevice *voltha.Device
	var copyFromNNIPort *voltha.LogicalPort
	for idx, nniPort := range nniPorts {
	if idx == 0 {
	copyFromNNIPort = nniPort
	} else if len(dr.Routes) > 0 {
	dr.copyFromExistingNNIRoutes(nniPort, copyFromNNIPort)
	return nil
	}
	// Get root device
	rootDevice, err = dr.getDevice(ctx, nniPort.DeviceId)
	if err != nil {
	return err
	}
	if len(rootDevice.Ports) == 0 {
	err = status.Errorf(codes.FailedPrecondition, "no-port-%s", rootDevice.Id)
	return err
	}
	for _, rootDevicePort := range rootDevice.Ports {
	if rootDevicePort.Type == voltha.Port_PON_OLT {
	log.Debugw("peers", log.Fields{"root-device-id": rootDevice.Id, "port-no": rootDevicePort.PortNo, "len-peers": len(rootDevicePort.Peers)})
	for _, rootDevicePeer := range rootDevicePort.Peers {
	childDevice, err = dr.getDevice(ctx, rootDevicePeer.DeviceId)
	if err != nil {
	return err
	}
	childPonPorts := dr.getDevicePonPorts(childDevice.Id, nniPort.DeviceId)
	if len(childPonPorts) < 1 {
	err = status.Errorf(codes.Aborted, "no-child-pon-port-%s", childDevice.Id)
	return err
	}
	// We use the first PON port on the ONU whose parent is the root device.
	childPonPort := childPonPorts[0].PortNo
	for _, childDevicePort := range childDevice.Ports {
	if childDevicePort.Type == voltha.Port_ETHERNET_UNI {
	childLogicalPort, exist := physPortToLogicalPortMap[concatDeviceIDPortID(childDevice.Id, childDevicePort.PortNo)]
	if !exist {
	// This can happen if this logical port has not been created yet for that device
	continue
	}
	dr.Routes[PathID{Ingress: nniPort.OfpPort.PortNo, Egress: childLogicalPort}] = []Hop{
	{DeviceID: rootDevice.Id, Ingress: nniPort.DevicePortNo, Egress: rootDevicePort.PortNo},
	{DeviceID: childDevice.Id, Ingress: childPonPort, Egress: childDevicePort.PortNo},
	}
	dr.Routes[PathID{Ingress: childLogicalPort, Egress: nniPort.OfpPort.PortNo}] = getReverseRoute(
	dr.Routes[PathID{Ingress: nniPort.OfpPort.PortNo, Egress: childLogicalPort}])
	}
	}
	}
	}
	}
	}
	return nil
	}

	// verifyPrecondition verify whether the preconditions are met to proceed with addition of the new logical port
	func (dr DeviceRoutes) addPortAndVerifyPrecondition(lp voltha.LogicalPort) error {
	var exist, nniLogicalPortExist, uniLogicalPortExist bool
	for _, existingLogicalPort := range dr.logicalPorts {
	nniLogicalPortExist = nniLogicalPortExist \|\| existingLogicalPort.RootPort
	uniLogicalPortExist = uniLogicalPortExist \|\| !existingLogicalPort.RootPort
	exist = exist \|\| existingLogicalPort.OfpPort.PortNo == lp.OfpPort.PortNo
	if nniLogicalPortExist && uniLogicalPortExist && exist {
	break
	}
	}
	if !exist {
	dr.logicalPorts = append(dr.logicalPorts, lp)
	nniLogicalPortExist = nniLogicalPortExist \|\| lp.RootPort
	uniLogicalPortExist = uniLogicalPortExist \|\| !lp.RootPort
	}

	// If we do not have both NNI and UNI ports then return an error
	if !(nniLogicalPortExist && uniLogicalPortExist) {
	fmt.Println("errors", nniLogicalPortExist, uniLogicalPortExist)
	return status.Error(codes.FailedPrecondition, "no-uni-and-nni-ports-combination")
	}
	return nil
	}

	// AddPort augments the current set of routes with new routes corresponding to the logical port "lp". If the routes have
	// not been built yet then use logical port "lps" to compute all current routes (lps includes lp)
	func (dr DeviceRoutes) AddPort(ctx context.Context, lp voltha.LogicalPort, lps []*voltha.LogicalPort) error {
	log.Debugw("add-port-to-routes", log.Fields{"port": lp, "len-logical-ports": len(lps)})

	dr.routeBuildLock.Lock()
	if len(dr.Routes) == 0 {
	dr.routeBuildLock.Unlock()
	return dr.ComputeRoutes(ctx, lps)
	}

	// A set of routes exists
	if err := dr.addPortAndVerifyPrecondition(lp); err != nil {
	dr.reset()
	dr.routeBuildLock.Unlock()
	return err
	}

	defer dr.routeBuildLock.Unlock()
	// Update the set of root ports, if applicable
	if lp.RootPort {
	dr.RootPorts[lp.OfpPort.PortNo] = lp.OfpPort.PortNo
	}

	var copyFromNNIPort *voltha.LogicalPort
	// Setup the physical ports to logical ports map
	nniPorts := make([]*voltha.LogicalPort, 0)
	for _, lport := range dr.logicalPorts {
	if lport.RootPort {
	nniPorts = append(nniPorts, lport)
	if copyFromNNIPort == nil && lport.OfpPort.PortNo != lp.OfpPort.PortNo {
	copyFromNNIPort = lport
	}
	}
	}

	if copyFromNNIPort == nil {
	// Trying to add the same NNI port. Just return
	return nil
	}

	// Adding NNI Port? If we are here we already have an NNI port with a set of routes. Just copy the existing
	// routes using an existing NNI port
	if lp.RootPort {
	dr.copyFromExistingNNIRoutes(lp, copyFromNNIPort)
	return nil
	}

	// Adding a UNI port
	for _, nniPort := range nniPorts {
	childPonPorts := dr.getDevicePonPorts(lp.DeviceId, nniPort.DeviceId)
	if len(childPonPorts) == 0 \|\| len(childPonPorts[0].Peers) == 0 {
	// Ports may not have been cached yet - get the device info which sets the PON port cache
	if _, err := dr.getDevice(ctx, lp.DeviceId); err != nil {
	dr.reset()
	return err
	}
	childPonPorts = dr.getDevicePonPorts(lp.DeviceId, nniPort.DeviceId)
	if len(childPonPorts) == 0 \|\| len(childPonPorts[0].Peers) == 0 {
	dr.reset()
	return status.Errorf(codes.FailedPrecondition, "no-pon-ports-%s", lp.DeviceId)
	}
	}
	// We use the first PON port on the child device
	childPonPort := childPonPorts[0]
	dr.Routes[PathID{Ingress: nniPort.OfpPort.PortNo, Egress: lp.OfpPort.PortNo}] = []Hop{
	{DeviceID: nniPort.DeviceId, Ingress: nniPort.DevicePortNo, Egress: childPonPort.Peers[0].PortNo},
	{DeviceID: lp.DeviceId, Ingress: childPonPort.PortNo, Egress: lp.DevicePortNo},
	}
	dr.Routes[PathID{Ingress: lp.OfpPort.PortNo, Egress: nniPort.OfpPort.PortNo}] = getReverseRoute(
	dr.Routes[PathID{Ingress: nniPort.OfpPort.PortNo, Egress: lp.OfpPort.PortNo}])
	}
	return nil
	}

	// Print prints routes
	func (dr *DeviceRoutes) Print() error {
	log.Debugw("Print", log.Fields{"logical-device-id": dr.logicalDeviceID, "logical-ports": dr.logicalPorts})
	if log.V(log.DebugLevel) {
	output := ""
	routeNumber := 1
	for k, v := range dr.Routes {
	key := fmt.Sprintf("LP:%d->LP:%d", k.Ingress, k.Egress)
	val := ""
	for _, i := range v {
	val += fmt.Sprintf("{%d->%s->%d},", i.Ingress, i.DeviceID, i.Egress)
	}
	val = val[:len(val)-1]
	output += fmt.Sprintf("%d:{%s=>%s} ", routeNumber, key, fmt.Sprintf("[%s]", val))
	routeNumber++
	}
	if len(dr.Routes) == 0 {
	log.Debugw("no-routes-found", log.Fields{"logical-device-id": dr.logicalDeviceID})
	} else {
	log.Debugw("graph_routes", log.Fields{"lDeviceId": dr.logicalDeviceID, "Routes": output})
	}
	}
	return nil
	}

	// IsUpToDate returns true if device is up to date
	func (dr DeviceRoutes) IsUpToDate(ld voltha.LogicalDevice) bool {
	dr.routeBuildLock.Lock()
	defer dr.routeBuildLock.Unlock()
	numNNI, numUNI := 0, 0
	if ld != nil {
	if len(dr.logicalPorts) != len(ld.Ports) {
	return false
	}
	numNNI = len(dr.RootPorts)
	numUNI = len(ld.Ports) - numNNI
	}
	return len(dr.Routes) == numNNInumUNI2
	}

	// getDevicePonPorts returns all the PON ports of a device whose peer device ID is peerDeviceID
	func (dr DeviceRoutes) getDevicePonPorts(deviceID string, peerDeviceID string) []voltha.Port {
	dr.devicesPonPortsLock.RLock()
	defer dr.devicesPonPortsLock.RUnlock()
	ponPorts := make([]*voltha.Port, 0)
	ports, exist := dr.devicesPonPorts[deviceID]
	if !exist {
	return ponPorts
	}
	//fmt.Println("getDevicePonPorts", deviceID, peerDeviceID, ports)
	for _, port := range ports {
	for _, peer := range port.Peers {
	if peer.DeviceId == peerDeviceID {
	ponPorts = append(ponPorts, port)
	}
	}
	}
	return ponPorts
	}

	//getDevice returns the from the model and updates the PON ports map of that device.
	func (dr DeviceRoutes) getDevice(ctx context.Context, deviceID string) (voltha.Device, error) {
	device, err := dr.getDeviceFromModel(ctx, deviceID)
	if err != nil {
	log.Errorw("device-not-found", log.Fields{"deviceId": deviceID, "error": err})
	return nil, err
	}
	dr.devicesPonPortsLock.Lock()
	defer dr.devicesPonPortsLock.Unlock()
	for _, port := range device.Ports {
	if port.Type == voltha.Port_PON_ONU \|\| port.Type == voltha.Port_PON_OLT {
	dr.devicesPonPorts[device.Id] = append(dr.devicesPonPorts[device.Id], port)
	}
	}
	return device, nil
	}

	//copyFromExistingNNIRoutes copies routes from an existing set of NNI routes
	func (dr DeviceRoutes) copyFromExistingNNIRoutes(newNNIPort voltha.LogicalPort, copyFromNNIPort *voltha.LogicalPort) {
	updatedRoutes := make(map[PathID][]Hop)
	for key, val := range dr.Routes {
	if key.Ingress == copyFromNNIPort.OfpPort.PortNo {
	updatedRoutes[PathID{Ingress: newNNIPort.OfpPort.PortNo, Egress: key.Egress}] = []Hop{
	{DeviceID: newNNIPort.DeviceId, Ingress: newNNIPort.DevicePortNo, Egress: val[0].Egress},
	val[1],
	}
	}
	if key.Egress == copyFromNNIPort.OfpPort.PortNo {
	updatedRoutes[PathID{Ingress: key.Ingress, Egress: newNNIPort.OfpPort.PortNo}] = []Hop{
	val[0],
	{DeviceID: newNNIPort.DeviceId, Ingress: val[1].Ingress, Egress: newNNIPort.DevicePortNo},
	}
	}
	updatedRoutes[key] = val
	}
	dr.Routes = updatedRoutes
	}

	// reset cleans up the device graph
	func (dr *DeviceRoutes) reset() {
	dr.rootPortsLock.Lock()
	dr.RootPorts = make(map[uint32]uint32)
	dr.rootPortsLock.Unlock()
	// Do not numGetDeviceCalledLock Routes, logicalPorts as the callee function already holds its numGetDeviceCalledLock.
	dr.Routes = make(map[PathID][]Hop)
	dr.logicalPorts = make([]*voltha.LogicalPort, 0)
	dr.devicesPonPortsLock.Lock()
	dr.devicesPonPorts = make(map[string][]*voltha.Port)
	dr.devicesPonPortsLock.Unlock()
	}

	//concatDeviceIdPortId formats a portid using the device id and the port number
	func concatDeviceIDPortID(deviceID string, portNo uint32) string {
	return fmt.Sprintf("%s:%d", deviceID, portNo)
	}

	//getReverseRoute returns the reverse of the route
	func getReverseRoute(route []Hop) []Hop {
	reverse := make([]Hop, len(route))
	for i, j := 0, len(route)-1; j >= 0; i, j = i+1, j-1 {
	reverse[i].DeviceID, reverse[i].Ingress, reverse[i].Egress = route[j].DeviceID, route[j].Egress, route[j].Ingress
	}
	return reverse
	}