internal/pkg/afrouter/source-router.go - voltha-api-server - Gitiles

 /*
  * Copyright 2018-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 afrouter

 /* Source-Router

    This router implements source routing where the caller identifies the
    component the message should be routed to. The `RouteField` should be
    configured with the gRPC field name to inspect to determine the
    destination. This field is assumed to be a string. That string will
    then be used to identify a particular connection on a particular
    backend.

    The source-router must be configured with a backend cluster, as all routers
    must identify a backend cluster. However, that backend cluster
    is merely a placeholder and is not used by the source-router. The
    source-router's Route() function will return whatever backend cluster is
    specified by the `RouteField`.
 */

 import (
 	"errors"
 	"fmt"
 	"github.com/golang/protobuf/proto"
 	"github.com/opencord/voltha-lib-go/v2/pkg/log"
 	"google.golang.org/grpc"
 	"regexp"
 	"strconv"
 )

 type SourceRouter struct {
 	name        string
 	grpcService string
 	methodMap   map[string]byte
 	cluster     *cluster
 }

 func newSourceRouter(rconf *RouterConfig, config *RouteConfig) (Router, error) {
 	var err error
 	var rtrn_err = false
 	var pkg_re = regexp.MustCompile(`^(\.[^.]+\.)(.+)$`)
 	// Validate the configuration

 	// A name must exist
 	if config.Name == "" {
 		log.Error("A router 'name' must be specified")
 		rtrn_err = true
 	}

 	if rconf.ProtoPackage == "" {
 		log.Error("A 'package' must be specified")
 		rtrn_err = true
 	}

 	if rconf.ProtoService == "" {
 		log.Error("A 'service' must be specified")
 		rtrn_err = true
 	}

 	if config.RouteField == "" {
 		log.Error("A 'routing_field' must be specified")
 		rtrn_err = true
 	}

 	// TODO The overrieds section is currently not being used
 	// so the router will route all methods based on the
 	// routing_field. This needs to be added so that methods
 	// can have different routing fields.
 	dr := SourceRouter{
 		name:        config.Name,
 		grpcService: rconf.ProtoService,
 		methodMap:   make(map[string]byte),
 	}

 	// Build the routing structure based on the loaded protobuf
 	// descriptor file and the config information.
 	type key struct {
 		method string
 		field  string
 	}
 	var fieldNumberLookup = make(map[key]byte)
 	for _, f := range rconf.protoDescriptor.File {
 		// Build a temporary map of message types by name.
 		for _, m := range f.MessageType {
 			for _, fld := range m.Field {
 				log.Debugf("Processing message '%s', field '%s'", *m.Name, *fld.Name)
 				fieldNumberLookup[key{*m.Name, *fld.Name}] = byte(*fld.Number)
 			}
 		}
 	}
 	for _, f := range rconf.protoDescriptor.File {
 		if *f.Package == rconf.ProtoPackage {
 			for _, s := range f.Service {
 				if *s.Name == rconf.ProtoService {
 					log.Debugf("Loading package data '%s' for service '%s' for router '%s'", *f.Package, *s.Name, dr.name)
 					// Now create a map keyed by method name with the value being the
 					// field number of the route selector.
 					var ok bool
 					for _, m := range s.Method {
 						// Find the input type in the messages and extract the
 						// field number and save it for future reference.
 						log.Debugf("Processing method '%s'", *m.Name)
 						// Determine if this is a method we're supposed to be processing.
 						if needMethod(*m.Name, config) {
 							log.Debugf("Enabling method '%s'", *m.Name)
 							pkg_methd := pkg_re.FindStringSubmatch(*m.InputType)
 							if pkg_methd == nil {
 								log.Errorf("Regular expression didn't match input type '%s'", *m.InputType)
 								rtrn_err = true
 							}
 							// The input type has the package name prepended to it. Remove it.
 							//in := (*m.InputType)[len(rconf.ProtoPackage)+2:]
 							in := pkg_methd[PKG_MTHD_MTHD]
 							dr.methodMap[*m.Name], ok = fieldNumberLookup[key{in, config.RouteField}]
 							if !ok {
 								log.Errorf("Method '%s' has no field named '%s' in it's parameter message '%s'",
 									*m.Name, config.RouteField, in)
 								rtrn_err = true
 							}
 						}
 					}
 				}
 			}
 		}
 	}

 	// We need to pick a cluster, because server will call cluster.handler. The choice we make doesn't
 	// matter, as we can return a different cluster from Route().
 	var ok bool
 	if dr.cluster, ok = clusters[config.backendCluster.Name]; !ok {
 		if dr.cluster, err = newBackendCluster(config.backendCluster); err != nil {
 			log.Errorf("Could not create a backend for router %s", config.Name)
 			rtrn_err = true
 		}
 	}

 	if rtrn_err {
 		return dr, fmt.Errorf("Failed to create a new router '%s'", dr.name)
 	}

 	return dr, nil
 }

 func (ar SourceRouter) Service() string {
 	return ar.grpcService
 }

 func (ar SourceRouter) Name() string {
 	return ar.name
 }

 func (ar SourceRouter) skipField(data *[]byte, idx *int) error {
 	switch (*data)[*idx] & 3 {
 	case 0: // Varint
 		// skip the field number/type
 		*idx++
 		// if the msb is set, then more bytes to follow
 		for (*data)[*idx] >= 128 {
 			*idx++
 		}
 		// the last byte doesn't have the msb set
 		*idx++
 	case 1: // 64 bit
 		*idx += 9
 	case 2: // Length delimited
 		// skip the field number / type
 		*idx++
 		// read a varint that tells length of string
 		b := proto.NewBuffer((*data)[*idx:])
 		t, _ := b.DecodeVarint()
 		// skip the length varint and the string bytes
 		// TODO: This assumes the varint was one byte long -- max string length is 127 bytes
 		*idx += int(t) + 1
 	case 3: // Deprecated
 	case 4: // Deprecated
 	case 5: // 32 bit
 		*idx += 5
 	}
 	return nil
 }

 func (ar SourceRouter) decodeProtoField(payload []byte, fieldId byte) (string, error) {
 	idx := 0
 	b := proto.NewBuffer([]byte{})
 	//b.DebugPrint("The Buffer", payload)
 	for { // Find the route selector field
 		if idx >= len(payload) {
 			err := fmt.Errorf("At end of message, attribute %d not found", fieldId)
 			return "", err
 		}

 		log.Debugf("Decoding source value attributeNumber: %d from %v at index %d", fieldId, payload, idx)
 		log.Debugf("Attempting match with payload: %d, methodTable: %d", payload[idx], fieldId)
 		if payload[idx]>>3 == fieldId {
 			log.Debugf("Method match with payload: %d, methodTable: %d", payload[idx], fieldId)
 			// TODO: Consider supporting other selector types.... Way, way in the future
 			// ok, the future is now, support strings as well... ugh.
 			var selector string
 			switch payload[idx] & 3 {
 			case 0: // Integer
 				b.SetBuf(payload[idx+1:])
 				v, e := b.DecodeVarint()
 				if e == nil {
 					log.Debugf("Decoded the ing field: %v", v)
 					selector = strconv.Itoa(int(v))
 				} else {
 					log.Errorf("Failed to decode varint %v", e)
 					return "", e
 				}
 			case 2: // Length delimited AKA string
 				b.SetBuf(payload[idx+1:])
 				v, e := b.DecodeStringBytes()
 				if e == nil {
 					log.Debugf("Decoded the string field: %v", v)
 					selector = v
 				} else {
 					log.Errorf("Failed to decode string %v", e)
 					return "", e
 				}
 			default:
 				err := errors.New("Only integer and string route selectors are permitted")
 				log.Error(err)
 				return "", err
 			}
 			return selector, nil
 		} else if err := ar.skipField(&payload, &idx); err != nil {
 			log.Errorf("Parsing message failed %v", err)
 			return "", err
 		}
 	}
 }

 func (ar SourceRouter) Route(sel interface{}) (*backend, *connection) {
 	log.Debugf("SourceRouter sel %v", sel)
 	switch sl := sel.(type) {
 	case *requestFrame:
 		log.Debugf("Route called for nbFrame with method %s", sl.methodInfo.method)
 		// Not a south affinity binding method, proceed with north affinity binding.
 		if selector, err := ar.decodeProtoField(sl.payload, ar.methodMap[sl.methodInfo.method]); err == nil {
 			// selector is

 			for _, cluster := range clusters {
 				for _, backend := range cluster.backends {
 					log.Debugf("Checking backend %s", backend.name)
 					for _, connection := range backend.connections {
 						log.Debugf("Checking connection %s", connection.name)
 						// caller specified a backend and a connection
 						if backend.name+"."+connection.name == selector {
 							return backend, connection
 						}
 					}
 					// caller specified just a backend
 					if backend.name == selector {
 						return backend, nil
 					}
 				}
 			}
 			sl.err = fmt.Errorf("Backend %s not found", selector)
 			return nil, nil
 		}
 	default:
 		log.Errorf("Internal: invalid data type in Route call %v", sel)
 		return nil, nil
 	}
 	log.Errorf("Bad routing in SourceRouter:Route")
 	return nil, nil
 }

 func (ar SourceRouter) GetMetaKeyVal(serverStream grpc.ServerStream) (string, string, error) {
 	return "", "", nil
 }

 func (ar SourceRouter) IsStreaming(_ string) (bool, bool) {
 	panic("not implemented")
 }

 func (ar SourceRouter) BackendCluster(mthd string, metaKey string) (*cluster, error) {
 	// unsupported?
 	return ar.cluster, nil
 }

 func (ar SourceRouter) FindBackendCluster(beName string) *cluster {
 	// unsupported?
 	if beName == ar.cluster.name {
 		return ar.cluster
 	}
 	return nil
 }

 func (rr SourceRouter) ReplyHandler(sel interface{}) error { // This is a no-op
 	return nil
 }
	/*
	* Copyright 2018-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 afrouter

	/* Source-Router

	This router implements source routing where the caller identifies the
	component the message should be routed to. The `RouteField` should be
	configured with the gRPC field name to inspect to determine the
	destination. This field is assumed to be a string. That string will
	then be used to identify a particular connection on a particular
	backend.

	The source-router must be configured with a backend cluster, as all routers
	must identify a backend cluster. However, that backend cluster
	is merely a placeholder and is not used by the source-router. The
	source-router's Route() function will return whatever backend cluster is
	specified by the `RouteField`.
	*/

	import (
	"errors"
	"fmt"
	"github.com/golang/protobuf/proto"
	"github.com/opencord/voltha-lib-go/v2/pkg/log"
	"google.golang.org/grpc"
	"regexp"
	"strconv"
	)

	type SourceRouter struct {
	name string
	grpcService string
	methodMap map[string]byte
	cluster *cluster
	}

	func newSourceRouter(rconf RouterConfig, config RouteConfig) (Router, error) {
	var err error
	var rtrn_err = false
	var pkg_re = regexp.MustCompile(`^(\.[^.]+\.)(.+)$`)
	// Validate the configuration

	// A name must exist
	if config.Name == "" {
	log.Error("A router 'name' must be specified")
	rtrn_err = true
	}

	if rconf.ProtoPackage == "" {
	log.Error("A 'package' must be specified")
	rtrn_err = true
	}

	if rconf.ProtoService == "" {
	log.Error("A 'service' must be specified")
	rtrn_err = true
	}

	if config.RouteField == "" {
	log.Error("A 'routing_field' must be specified")
	rtrn_err = true
	}

	// TODO The overrieds section is currently not being used
	// so the router will route all methods based on the
	// routing_field. This needs to be added so that methods
	// can have different routing fields.
	dr := SourceRouter{
	name: config.Name,
	grpcService: rconf.ProtoService,
	methodMap: make(map[string]byte),
	}

	// Build the routing structure based on the loaded protobuf
	// descriptor file and the config information.
	type key struct {
	method string
	field string
	}
	var fieldNumberLookup = make(map[key]byte)
	for _, f := range rconf.protoDescriptor.File {
	// Build a temporary map of message types by name.
	for _, m := range f.MessageType {
	for _, fld := range m.Field {
	log.Debugf("Processing message '%s', field '%s'", m.Name, fld.Name)
	fieldNumberLookup[key{m.Name, fld.Name}] = byte(*fld.Number)
	}
	}
	}
	for _, f := range rconf.protoDescriptor.File {
	if *f.Package == rconf.ProtoPackage {
	for _, s := range f.Service {
	if *s.Name == rconf.ProtoService {
	log.Debugf("Loading package data '%s' for service '%s' for router '%s'", f.Package, s.Name, dr.name)
	// Now create a map keyed by method name with the value being the
	// field number of the route selector.
	var ok bool
	for _, m := range s.Method {
	// Find the input type in the messages and extract the
	// field number and save it for future reference.
	log.Debugf("Processing method '%s'", *m.Name)
	// Determine if this is a method we're supposed to be processing.
	if needMethod(*m.Name, config) {
	log.Debugf("Enabling method '%s'", *m.Name)
	pkg_methd := pkg_re.FindStringSubmatch(*m.InputType)
	if pkg_methd == nil {
	log.Errorf("Regular expression didn't match input type '%s'", *m.InputType)
	rtrn_err = true
	}
	// The input type has the package name prepended to it. Remove it.
	//in := (*m.InputType)[len(rconf.ProtoPackage)+2:]
	in := pkg_methd[PKG_MTHD_MTHD]
	dr.methodMap[*m.Name], ok = fieldNumberLookup[key{in, config.RouteField}]
	if !ok {
	log.Errorf("Method '%s' has no field named '%s' in it's parameter message '%s'",
	*m.Name, config.RouteField, in)
	rtrn_err = true
	}
	}
	}
	}
	}
	}
	}

	// We need to pick a cluster, because server will call cluster.handler. The choice we make doesn't
	// matter, as we can return a different cluster from Route().
	var ok bool
	if dr.cluster, ok = clusters[config.backendCluster.Name]; !ok {
	if dr.cluster, err = newBackendCluster(config.backendCluster); err != nil {
	log.Errorf("Could not create a backend for router %s", config.Name)
	rtrn_err = true
	}
	}

	if rtrn_err {
	return dr, fmt.Errorf("Failed to create a new router '%s'", dr.name)
	}

	return dr, nil
	}

	func (ar SourceRouter) Service() string {
	return ar.grpcService
	}

	func (ar SourceRouter) Name() string {
	return ar.name
	}

	func (ar SourceRouter) skipField(data []byte, idx int) error {
	switch (data)[idx] & 3 {
	case 0: // Varint
	// skip the field number/type
	*idx++
	// if the msb is set, then more bytes to follow
	for (data)[idx] >= 128 {
	*idx++
	}
	// the last byte doesn't have the msb set
	*idx++
	case 1: // 64 bit
	*idx += 9
	case 2: // Length delimited
	// skip the field number / type
	*idx++
	// read a varint that tells length of string
	b := proto.NewBuffer((data)[idx:])
	t, _ := b.DecodeVarint()
	// skip the length varint and the string bytes
	// TODO: This assumes the varint was one byte long -- max string length is 127 bytes
	*idx += int(t) + 1
	case 3: // Deprecated
	case 4: // Deprecated
	case 5: // 32 bit
	*idx += 5
	}
	return nil
	}

	func (ar SourceRouter) decodeProtoField(payload []byte, fieldId byte) (string, error) {
	idx := 0
	b := proto.NewBuffer([]byte{})
	//b.DebugPrint("The Buffer", payload)
	for { // Find the route selector field
	if idx >= len(payload) {
	err := fmt.Errorf("At end of message, attribute %d not found", fieldId)
	return "", err
	}

	log.Debugf("Decoding source value attributeNumber: %d from %v at index %d", fieldId, payload, idx)
	log.Debugf("Attempting match with payload: %d, methodTable: %d", payload[idx], fieldId)
	if payload[idx]>>3 == fieldId {
	log.Debugf("Method match with payload: %d, methodTable: %d", payload[idx], fieldId)
	// TODO: Consider supporting other selector types.... Way, way in the future
	// ok, the future is now, support strings as well... ugh.
	var selector string
	switch payload[idx] & 3 {
	case 0: // Integer
	b.SetBuf(payload[idx+1:])
	v, e := b.DecodeVarint()
	if e == nil {
	log.Debugf("Decoded the ing field: %v", v)
	selector = strconv.Itoa(int(v))
	} else {
	log.Errorf("Failed to decode varint %v", e)
	return "", e
	}
	case 2: // Length delimited AKA string
	b.SetBuf(payload[idx+1:])
	v, e := b.DecodeStringBytes()
	if e == nil {
	log.Debugf("Decoded the string field: %v", v)
	selector = v
	} else {
	log.Errorf("Failed to decode string %v", e)
	return "", e
	}
	default:
	err := errors.New("Only integer and string route selectors are permitted")
	log.Error(err)
	return "", err
	}
	return selector, nil
	} else if err := ar.skipField(&payload, &idx); err != nil {
	log.Errorf("Parsing message failed %v", err)
	return "", err
	}
	}
	}

	func (ar SourceRouter) Route(sel interface{}) (backend, connection) {
	log.Debugf("SourceRouter sel %v", sel)
	switch sl := sel.(type) {
	case *requestFrame:
	log.Debugf("Route called for nbFrame with method %s", sl.methodInfo.method)
	// Not a south affinity binding method, proceed with north affinity binding.
	if selector, err := ar.decodeProtoField(sl.payload, ar.methodMap[sl.methodInfo.method]); err == nil {
	// selector is

	for _, cluster := range clusters {
	for _, backend := range cluster.backends {
	log.Debugf("Checking backend %s", backend.name)
	for _, connection := range backend.connections {
	log.Debugf("Checking connection %s", connection.name)
	// caller specified a backend and a connection
	if backend.name+"."+connection.name == selector {
	return backend, connection
	}
	}
	// caller specified just a backend
	if backend.name == selector {
	return backend, nil
	}
	}
	}
	sl.err = fmt.Errorf("Backend %s not found", selector)
	return nil, nil
	}
	default:
	log.Errorf("Internal: invalid data type in Route call %v", sel)
	return nil, nil
	}
	log.Errorf("Bad routing in SourceRouter:Route")
	return nil, nil
	}

	func (ar SourceRouter) GetMetaKeyVal(serverStream grpc.ServerStream) (string, string, error) {
	return "", "", nil
	}

	func (ar SourceRouter) IsStreaming(_ string) (bool, bool) {
	panic("not implemented")
	}

	func (ar SourceRouter) BackendCluster(mthd string, metaKey string) (*cluster, error) {
	// unsupported?
	return ar.cluster, nil
	}

	func (ar SourceRouter) FindBackendCluster(beName string) *cluster {
	// unsupported?
	if beName == ar.cluster.name {
	return ar.cluster
	}
	return nil
	}

	func (rr SourceRouter) ReplyHandler(sel interface{}) error { // This is a no-op
	return nil
	}