forked from 517888/oganization
/
main.go
442 lines (427 loc) · 13.6 KB
/
main.go
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package main
//test
import (
"bytes"
"encoding/binary"
"flag"
"fmt"
"github.com/google/gopacket"
"github.com/google/gopacket/ip4defrag"
"github.com/google/gopacket/layers"
"github.com/google/gopacket/pcap"
"github.com/google/gopacket/pcapgo"
"github.com/google/gopacket/tcpassembly"
"github.com/google/gopacket/tcpassembly/tcpreader"
// "github.com/miekg/dns"
"io"
"os"
"time"
)
/*
func writeData(w *pcapgo.Writer, source *gopacket.PacketSource) error {
defragger := ip4defrag.NewIPv4Defragmenter()
w.WriteFileHeader(65536, layers.LinkTypeEthernet)
for packet := range source.Packets() {
tcpLayer := packet.Layer(layers.LayerTypeTCP)
if tcpLayer != nil {
// do assemble
} else {
v6Layer := packet.Layer(layers.LayerTypeIPv6)
if v6Layer != nil {
// do v6 defrag
} else {
v4Layer := packet.Layer(layers.LayerTypeIPv4)
if v4Layer == nil {
continue
}
in, err := defragger.DefragIPv4(v4Layer)
if err != nil {
return err
} else if in == nil { //part of fragment continue
continue
} else {
err := w.WritePacket(packet.Metadata().CaptureInfo, in.LayerContents()) //write the header
if err != nil {
return err
}
err := w.WritePacket(packet.Metadata().CaptureInfo, in.LayerPayload()) // write the payload
if err != nil {
return err
}
}
}
}
}
return nil
}*/
func readSource(source *gopacket.PacketSource, tcpPack chan gopacket.Packet,
normalPack chan gopacket.Packet, fragV4Pack chan gopacket.Packet, fragv6Pack chan gopacket.Packet,
endNotification chan bool) {
for packet := range source.Packets() {
tcpLayer := packet.Layer(layers.LayerTypeTCP)
if tcpLayer != nil {
tcpPack <- packet
// send packet to tcp ASSEMBLER
} else {
v6Layer := packet.Layer(layers.LayerTypeIPv6)
if v6Layer != nil {
v6frag := packet.Layer(layers.LayerTypeIPv6Fragment)
if v6frag == nil {
ipv6 := v6Layer.(*layers.IPv6)
IPserializeBuffer := gopacket.NewSerializeBuffer()
buf, _ := IPserializeBuffer.PrependBytes(len(ipv6.Payload))
copy(buf, ipv6.Payload)
ops := gopacket.SerializeOptions{
FixLengths: true,
ComputeChecksums: true,
}
ipv6.SerializeTo(IPserializeBuffer, ops)
sendPack := gopacket.NewPacket(IPserializeBuffer.Bytes(), layers.LayerTypeIPv6, gopacket.Default)
err := sendPack.ErrorLayer()
if err != nil {
fmt.Println("Error decoding some part of the packet:", err)
normalPack <- packet
} else {
sendPack.Metadata().CaptureLength = len(sendPack.Data())
sendPack.Metadata().Length = len(sendPack.Data())
normalPack <- sendPack
}
} else {
fragv6Pack <- packet
}
// do v6 process
} else {
v4Layer := packet.Layer(layers.LayerTypeIPv4)
if v4Layer == nil {
continue
}
ip := v4Layer.(*layers.IPv4)
if notFraV4(ip) {
IPserializeBuffer := gopacket.NewSerializeBuffer()
buf, _ := IPserializeBuffer.PrependBytes(len(ip.Payload))
copy(buf, ip.Payload)
ops := gopacket.SerializeOptions{
FixLengths: true,
ComputeChecksums: true,
}
// ipBuffer, _ := IPserializeBuffer.PrependBytes(len(ip.Payload))
// copy(ipBuffer, ip.Payload)
ip.SerializeTo(IPserializeBuffer, ops)
sendPack := gopacket.NewPacket(IPserializeBuffer.Bytes(), layers.LayerTypeIPv4, gopacket.Default)
err := sendPack.ErrorLayer()
if err != nil {
fmt.Println("Error decoding some part of the packet:", err)
normalPack <- packet
} else {
sendPack.Metadata().CaptureLength = len(sendPack.Data())
sendPack.Metadata().Length = len(sendPack.Data())
normalPack <- sendPack
}
} else {
fragV4Pack <- packet
}
/*
in, err := defragger.DefragIPv4(v4Layer)
if err != nil {
return err
} else if in == nil { //part of fragment continue
continue
} else {
err := w.WritePacket(packet.Metadata().CaptureInfo, in.LayerContents()) //write the header
if err != nil {
return err
}
err := w.WritePacket(packet.Metadata().CaptureInfo, in.LayerPayload()) // write the payload
if err != nil {
return err
}
}*/
}
}
time.Sleep(time.Millisecond * 500)
}
fmt.Printf("done reading in readSource()\n")
// give a time to write file
endNotification <- true
}
func pcapWrite(w *pcapgo.Writer, pack chan gopacket.Packet) error {
var err error
for {
packet := <-pack
fmt.Println("receive a package in pcap Write")
err = w.WritePacket(packet.Metadata().CaptureInfo, packet.Data()) // write the payload
if err != nil {
fmt.Println("error in Write File: ", err)
continue
}
fmt.Println("susccessfully write a package")
}
return err
}
func v6Defrag(v6frag chan gopacket.Packet, normalPack chan gopacket.Packet) error {
defragger := NewIPv6Defragmenter()
for {
fragpack := <-v6frag
in, err := defragger.DefragIPv6(fragpack)
if err != nil {
return err
} else if in == nil {
continue
} else {
normalPack <- in
}
}
}
func v4Defrag(v4frag chan gopacket.Packet, normalPack chan gopacket.Packet) error {
defragger := ip4defrag.NewIPv4Defragmenter()
for {
fragpack := <-v4frag
layer := fragpack.Layer(layers.LayerTypeIPv4).(*layers.IPv4)
in, err := defragger.DefragIPv4(layer)
if err != nil {
return err //error handle
} else if in == nil { //part of fragment continue
continue
} else {
b := gopacket.NewSerializeBuffer()
ops := gopacket.SerializeOptions{
FixLengths: true,
ComputeChecksums: true,
}
// it should be remebered that you should copy the payload in when you use SerializeTo
ip_payload, _ := b.PrependBytes(len(in.Payload))
copy(ip_payload, in.Payload)
in.SerializeTo(b, ops)
resultPack := gopacket.NewPacket(b.Bytes(), layers.LayerTypeIPv4, gopacket.Default)
err := resultPack.ErrorLayer()
if err != nil {
fmt.Println("Error decoding some part of the packet:", err) //need error handle here
//return
continue
}
resultPack.Metadata().CaptureLength = len(resultPack.Data())
resultPack.Metadata().Length = len(resultPack.Data())
fmt.Println("defrag a package")
normalPack <- resultPack
}
}
return nil
}
func notFraV4(ip *layers.IPv4) bool {
// don't defrag packet with DF flag
if ip.Flags&layers.IPv4DontFragment != 0 {
return true
}
// don't defrag not fragmented ones
if ip.Flags&layers.IPv4MoreFragments == 0 && ip.FragOffset == 0 {
return true
}
return false
}
func tcpAssemble(tcpPack chan gopacket.Packet, assembler *tcpassembly.Assembler) {
for packet := range tcpPack {
tcp := packet.TransportLayer().(*layers.TCP)
assembler.AssembleWithTimestamp(packet.NetworkLayer().NetworkFlow(), tcp, packet.Metadata().Timestamp)
}
}
type DNSStreamFactory struct {
normal chan gopacket.Packet
}
// httpStream will handle the actual decoding of http requests.
type dnsStream struct {
net, transport gopacket.Flow
r tcpreader.ReaderStream
}
func (h *DNSStreamFactory) New(net, transport gopacket.Flow) tcpassembly.Stream {
hstream := &dnsStream{
net: net,
transport: transport,
r: tcpreader.NewReaderStream(),
}
go hstream.run(h.normal) // Important... we must guarantee that data from the reader stream is read.
// ReaderStream implements tcpassembly.Stream, so we can return a pointer to it.
return &hstream.r
}
func (h *dnsStream) run(nomalpack chan gopacket.Packet) {
//fmt.Printf("reading rebuilt TCP stream\n")
for {
len_buf := make([]byte, 2, 2)
nread, err := io.ReadFull(&h.r, len_buf)
//fmt.Printf("Read %d bytes\n", nread)
if nread < 2 || (err != nil && err != io.EOF) {
// needs error handle there
// fmt.Println("error in reading first two bytes: %s", err)
break
}
msg_len := uint(len_buf[0])<<8 | uint(len_buf[1])
// fmt.Printf("msg_len:%d\n", msg_len)
msg_buf := make([]byte, msg_len, msg_len)
nread, err = io.ReadFull(&h.r, msg_buf)
if err != nil {
// fmt.Println("error in reading full tcp data: %s", err)
break
}
h.creatPacket(msg_buf, nomalpack)
}
}
func (h *dnsStream) creatPacket(msg_buf []byte, nomalPack chan gopacket.Packet) {
var sourcePort, DesPort int16
//read the port from tranport flow
b_buf := bytes.NewBuffer(h.transport.Src().Raw())
binary.Read(b_buf, binary.BigEndian, &sourcePort)
b_buf = bytes.NewBuffer(h.transport.Dst().Raw())
binary.Read(b_buf, binary.BigEndian, &DesPort)
//new a UDP layer
udpLayer := layers.UDP{
BaseLayer: layers.BaseLayer{
Contents: []byte{},
Payload: msg_buf,
},
SrcPort: layers.UDPPort(sourcePort),
DstPort: layers.UDPPort(DesPort),
Length: 1024,
Checksum: 30026,
}
UDPNewSerializBuffer := gopacket.NewSerializeBuffer() // this buffer could be used as a payload of IP layer
udpBuffer, _ := UDPNewSerializBuffer.PrependBytes(len(msg_buf))
copy(udpBuffer, msg_buf)
ops := gopacket.SerializeOptions{
FixLengths: true,
ComputeChecksums: true,
}
if h.net.EndpointType() == layers.EndpointIPv4 {
ip_checksum := layers.IPv4{}
ip_checksum.Version = 4
ip_checksum.TTL = 0
ip_checksum.SrcIP = h.net.Src().Raw()
ip_checksum.DstIP = h.net.Dst().Raw()
udpLayer.SetNetworkLayerForChecksum(&ip_checksum)
} else {
ip6_checksum := layers.IPv6{}
ip6_checksum.Version = 6
ip6_checksum.NextHeader = layers.IPProtocolNoNextHeader
ip6_checksum.HopLimit = 0
ip6_checksum.SrcIP = h.net.Src().Raw()
ip6_checksum.DstIP = h.net.Dst().Raw()
udpLayer.SetNetworkLayerForChecksum(&ip6_checksum)
}
err := udpLayer.SerializeTo(UDPNewSerializBuffer, ops)
if err != nil {
fmt.Print("error in create udp Layer")
return
//err = nil
// need err handle there
}
fmt.Println("finished creat udplayer, the length is ", udpLayer.Length)
if h.net.EndpointType() == layers.EndpointIPv4 { // if it is from ipv4, construct a ipv4 layer
ip := layers.IPv4{
BaseLayer: layers.BaseLayer{
Contents: []byte{},
Payload: UDPNewSerializBuffer.Bytes(),
},
Version: 4,
IHL: 0,
TOS: 0,
Length: 0,
Id: 0,
Flags: 0,
FragOffset: 0,
TTL: 0,
Protocol: layers.IPProtocolUDP,
Checksum: 0,
SrcIP: h.net.Src().Raw(),
DstIP: h.net.Dst().Raw(),
Options: []layers.IPv4Option{},
Padding: []byte{},
}
//serialize it and use the serilize buffer to new packet
IPserializeBuffer := gopacket.NewSerializeBuffer()
ipBuffer, _ := IPserializeBuffer.PrependBytes(len(UDPNewSerializBuffer.Bytes()))
copy(ipBuffer, UDPNewSerializBuffer.Bytes())
err = ip.SerializeTo(IPserializeBuffer, ops)
if err != nil {
fmt.Print("error in create ipv4 Layer")
return
//err = nil
// need err handle there
}
fmt.Println("finished creat ip, the length is ", ip.Length)
resultPack := gopacket.NewPacket(IPserializeBuffer.Bytes(), layers.LayerTypeIPv4, gopacket.Default)
resultPack.Metadata().CaptureLength = len(resultPack.Data())
resultPack.Metadata().Length = len(resultPack.Data())
//seems the capture length is 0 so the pcapwrite cannot write it, try to give them a write value
nomalPack <- resultPack
return
} else if h.net.EndpointType() == layers.EndpointIPv6 {
// if it is in IPV6 contruct ipv6 packet
ip := layers.IPv6{
BaseLayer: layers.BaseLayer{
Contents: []byte{},
Payload: UDPNewSerializBuffer.Bytes(),
},
Version: 6,
TrafficClass: 0,
FlowLabel: 0,
Length: 0,
NextHeader: layers.IPProtocolNoNextHeader, //no sure what next header should be used there
HopLimit: 0,
SrcIP: h.net.Src().Raw(),
DstIP: h.net.Dst().Raw(),
HopByHop: nil,
// hbh will be pointed to by HopByHop if that layer exists.
}
IPserializeBuffer := gopacket.NewSerializeBuffer()
err := ip.SerializeTo(IPserializeBuffer, ops)
if err != nil {
fmt.Printf("error in creat IPV6 Layer")
return
}
fmt.Println("finished creat ip, the length is ", ip.Length)
resultPack := gopacket.NewPacket(IPserializeBuffer.Bytes(), layers.LayerTypeIPv6, gopacket.Default)
resultPack.Metadata().CaptureLength = len(resultPack.Data())
resultPack.Metadata().Length = len(resultPack.Data())
//seems the capture length is 0 so the pcapwrite cannot write it, try to give them a write value
nomalPack <- resultPack
return
} else {
return //unknown network just return?
}
}
func main() {
var FilePathInput string
var FilePathOutput string
flag.StringVar(&FilePathInput, "in", "", "the path of PCAP file")
flag.StringVar(&FilePathOutput, "out", "", "the output file")
flag.Parse() // in mind if we need to do search in file.
if FilePathInput == "" || FilePathOutput == "" {
fmt.Print("lack of parameters!")
return
}
handle, err := pcap.OpenOffline(FilePathInput)
if err != nil {
panic(err)
}
defer handle.Close()
packetSource := gopacket.NewPacketSource(handle, handle.LinkType())
//need to add tcp assemble and udp defrag here.
Output, err := os.Create(FilePathOutput)
w := pcapgo.NewWriter(Output)
w.WriteFileHeader(65536, layers.LinkTypeRaw)
defer Output.Close()
// need add function call here
tcpPack := make(chan gopacket.Packet, 5) // maybe need change buffersize for chan
nomalPack := make(chan gopacket.Packet, 5)
fragV4Pack := make(chan gopacket.Packet, 5)
fragV6Pack := make(chan gopacket.Packet, 5)
endNotification := make(chan bool)
go readSource(packetSource, tcpPack, nomalPack, fragV4Pack, fragV6Pack, endNotification)
go v6Defrag(fragV6Pack, nomalPack)
go v4Defrag(fragV4Pack, nomalPack)
go pcapWrite(w, nomalPack)
streamFactory := &DNSStreamFactory{normal: nomalPack}
streamPool := tcpassembly.NewStreamPool(streamFactory)
assembler := tcpassembly.NewAssembler(streamPool)
go tcpAssemble(tcpPack, assembler)
// wait for the reading to finish
<-endNotification
}