record.go

package ndntdump

import (
	"io"

	"github.com/gopacket/gopacket"
	"github.com/usnistgov/ndn-dpdk/ndn"
)

// Direction indicates traffic direction.
type Direction string

// Direction values.
const (
	DirectionRX Direction = ">"
	DirectionTX Direction = "<"
)

// PktType indicates NDN packet type.
type PktType string

// PktType values.
const (
	PktTypeFragment PktType = "F"
	PktTypeInterest PktType = "I"
	PktTypeData     PktType = "D"
	PktTypeNack     PktType = "N"
)

// Record describes a parsed NDN packet.
type Record struct {
	Wire        []byte               `json:"-"`
	CaptureInfo gopacket.CaptureInfo `json:"-"`

	DirType   string `json:"t"`     // packet direction and type
	Timestamp int64  `json:"ts"`    // Unix epoch nanoseconds
	Flow      []byte `json:"flow"`  // flow key
	Size2     int    `json:"size2"` // packet size at NDNLPv2 layer

	Size3       int        `json:"size3,omitempty"`       // packet size at L3
	NackReason  int        `json:"nackReason,omitempty"`  // Nack reason
	Name        ndn.Name   `json:"name,omitempty"`        // packet name
	CanBePrefix bool       `json:"cbp,omitempty"`         // Interest CanBePrefix
	MustBeFresh bool       `json:"mbf,omitempty"`         // Interest MustBeFresh
	FwHint      []ndn.Name `json:"fwHint,omitempty"`      // Interest ForwardingHint
	Lifetime    int        `json:"lifetime,omitempty"`    // Interest InterestLifetime (ms)
	HopLimit    int        `json:"hopLimit,omitempty"`    // Interest HopLimit
	ContentType int        `json:"contentType,omitempty"` // Data ContentType
	Freshness   int        `json:"freshness,omitempty"`   // Data FreshnessPeriod (ms)
	FinalBlock  bool       `json:"finalBlock,omitempty"`  // Data is final block
}

// SaveInterest saves Interest/Nack fields on this Record.
func (rec *Record) SaveInterest(interest ndn.Interest, nackReason uint8) {
	rec.Name = interest.Name
	rec.CanBePrefix = interest.CanBePrefix
	rec.MustBeFresh = interest.MustBeFresh
	rec.FwHint = interest.ForwardingHint
	rec.Lifetime = int(interest.Lifetime.Milliseconds())
	rec.HopLimit = int(interest.HopLimit)
	rec.NackReason = int(nackReason)
}

// SaveData saves Data fields on this Record.
func (rec *Record) SaveData(data ndn.Data) {
	rec.Name = data.Name
	rec.ContentType = int(data.ContentType)
	rec.Freshness = int(data.Freshness.Milliseconds())
	rec.FinalBlock = data.IsFinalBlock()
}

// RecordOutput represents an output stream.
type RecordOutput interface {
	io.Closer
	Write(rec Record) error
}