/
nexthop.go
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/
nexthop.go
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/*
* Copyright (C) 2018 Red Hat, Inc.
*
* 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 ofthe 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 specificlanguage governing permissions and
* limitations under the License.
*
*/
package traversal
import (
"encoding/json"
"errors"
"fmt"
"net"
"github.com/skydive-project/skydive/graffiti/graph/traversal"
"github.com/skydive-project/skydive/topology"
)
// NextHopTraversalExtension describes a new extension to enhance the topology
type NextHopTraversalExtension struct {
NextHopToken traversal.Token
}
// NextHopGremlinTraversalStep nexthops step
type NextHopGremlinTraversalStep struct {
context traversal.GremlinTraversalContext
ip net.IP
}
// NewNextHopTraversalExtension returns a new graph traversal extension
func NewNextHopTraversalExtension() *NextHopTraversalExtension {
return &NextHopTraversalExtension{
NextHopToken: traversalNextHopToken,
}
}
// ScanIdent returns an associated graph token
func (e *NextHopTraversalExtension) ScanIdent(s string) (traversal.Token, bool) {
switch s {
case "NEXTHOP":
return e.NextHopToken, true
}
return traversal.IDENT, false
}
// ParseStep parses nexthops step
func (e *NextHopTraversalExtension) ParseStep(t traversal.Token, p traversal.GremlinTraversalContext) (traversal.GremlinTraversalStep, error) {
switch t {
case e.NextHopToken:
default:
return nil, nil
}
if len(p.Params) != 1 {
return nil, fmt.Errorf("NextHop accepts one parameter : %v", p.Params)
}
ipStr, ok := p.Params[0].(string)
if !ok {
return nil, errors.New("NextHop parameter have to be a string")
}
ip := net.ParseIP(ipStr)
if ip == nil {
return nil, errors.New("NextHop parameter have to be a valid IP address")
}
return &NextHopGremlinTraversalStep{context: p, ip: ip}, nil
}
// Exec NextHop step
func (nh *NextHopGremlinTraversalStep) Exec(last traversal.GraphTraversalStep) (traversal.GraphTraversalStep, error) {
switch tv := last.(type) {
case *traversal.GraphTraversalV:
nextHops := make(map[string]*topology.NextHop)
tv.GraphTraversal.RLock()
for _, node := range tv.GetNodes() {
if nextHop, err := topology.GetNextHop(node, nh.ip); err == nil {
nextHops[string(node.ID)] = nextHop
}
}
tv.GraphTraversal.RUnlock()
return NewNextHopTraversalStep(tv.GraphTraversal, nextHops), nil
}
return nil, traversal.ErrExecutionError
}
// Reduce nexthop step
func (nh *NextHopGremlinTraversalStep) Reduce(next traversal.GremlinTraversalStep) (traversal.GremlinTraversalStep, error) {
return next, nil
}
// Context NextHop step
func (nh *NextHopGremlinTraversalStep) Context() *traversal.GremlinTraversalContext {
return &nh.context
}
// NextHopTraversalStep traversal step of nexthop
type NextHopTraversalStep struct {
GraphTraversal *traversal.GraphTraversal
nexthops map[string]*topology.NextHop
error error
}
// NewNextHopTraversalStep creates a new traversal nexthop step
func NewNextHopTraversalStep(gt *traversal.GraphTraversal, value map[string]*topology.NextHop) *NextHopTraversalStep {
tv := &NextHopTraversalStep{
GraphTraversal: gt,
nexthops: value,
}
return tv
}
// NewNextHopTraversalStepFromError creates a new traversal nexthop step
func NewNextHopTraversalStepFromError(err ...error) *NextHopTraversalStep {
tv := &NextHopTraversalStep{}
if len(err) > 0 {
tv.error = err[0]
}
return tv
}
// Values return the nexthops
func (t *NextHopTraversalStep) Values() []interface{} {
if len(t.nexthops) == 0 {
return []interface{}{}
}
return []interface{}{t.nexthops}
}
// MarshalJSON serialize in JSON
func (t *NextHopTraversalStep) MarshalJSON() ([]byte, error) {
values := t.Values()
t.GraphTraversal.RLock()
defer t.GraphTraversal.RUnlock()
return json.Marshal(values)
}
func (t *NextHopTraversalStep) Error() error {
return t.error
}