packet_source.go

/*
 *    HoneyBadger core library for detecting TCP injection attacks
 *
 *    Copyright (C) 2014, 2015  David Stainton
 *
 *    This program is free software: you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation, either version 3 of the License, or
 *    (at your option) any later version.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package types

import (
	"bytes"
	"encoding/hex"
	"fmt"
	"time"

	"github.com/google/gopacket"
	"github.com/google/gopacket/layers"
)

type SnifferDriverOptions struct {
	DAQ          string
	Filename     string
	Device       string
	Snaplen      int32
	WireDuration time.Duration
	Filter       string
}

// PacketDataSource is an interface for some source of packet data.
type PacketDataSourceCloser interface {
	// ReadPacketData returns the next packet available from this data source.
	// It returns:
	//  data:  The bytes of an individual packet.
	//  ci:  Metadata about the capture
	//  err:  An error encountered while reading packet data.  If err != nil,
	//    then data/ci will be ignored.
	ReadPacketData() (data []byte, ci gopacket.CaptureInfo, err error)
	// Close closes the ethernet sniffer and returns nil if no error was found.
	Close() error
}

type Supervisor interface {
	Stopped()
	Run()
}

type PacketSource interface {
	Start()
	Stop()
	SetSupervisor(Supervisor)
	GetStartedChan() chan bool // used for unit tests
}

// PacketManifest is used to send parsed packets via channels to other goroutines
type PacketManifest struct {
	Timestamp time.Time
	Flow      *TcpIpFlow
	RawPacket []byte
	Ethernet  *layers.Ethernet
	IPv4      *layers.IPv4
	IPv6      *layers.IPv6
	TCP       *layers.TCP
	Payload   gopacket.Payload
}

func (p PacketManifest) String() string {
	var buffer bytes.Buffer
	buffer.WriteString(fmt.Sprintf("TCP Flow: %s\n", *p.Flow))
	buffer.WriteString(fmt.Sprintf("TCP Sequence %d\n", p.TCP.Seq))
	buffer.WriteString("Packet payload hex dump:\n")
	buffer.WriteString(hex.Dump(p.Payload))
	return buffer.String()
}