/
sniff.go
250 lines (225 loc) · 7.02 KB
/
sniff.go
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package sniff
import (
"time"
"context"
"sync"
"bytes"
"encoding/json"
"reflect"
"github.com/sirupsen/logrus"
"github.com/google/gopacket"
"github.com/google/gopacket/layers"
"github.com/google/gopacket/pcap"
"github.com/elastic/go-elasticsearch/v8"
"github.com/elastic/go-elasticsearch/v8/esutil"
)
type PacketDocument struct {
Link LinkLayerDoc `json:"link_layer"`
Network NetworkLayerDoc `json:"network_layer"`
Transport TransportLayerDoc `json:"transport_layer"`
App ApplicationLayerDoc `json:"application_layer"`
}
type LinkLayerDoc struct {
LayerType string `json:"layer_type"`
SrcMAC string `json:"src_mac"`
DstMAC string `json:"dst_mac"`
}
func parseLinkLayer(packet gopacket.Packet) LinkLayerDoc {
out := new(LinkLayerDoc)
if layer := packet.LinkLayer(); layer != nil {
out.LayerType = layer.LayerType().String()
lType := layer.LayerType()
switch {
case lType == layers.LayerTypeEthernet:
out.SrcMAC = layer.LinkFlow().Src().String()
out.DstMAC = layer.LinkFlow().Dst().String()
case lType == layers.LayerTypeARP:
logrus.Debug(layer)
}
}
return *out
}
type NetworkLayerDoc struct {
LayerType string `json:"layer_type"`
SrcIP string `json:"src_ip"`
DstIP string `json:"dst_ip"`
Operation uint16 `json:"operation"`
}
func parseNetworkLayer(packet gopacket.Packet) NetworkLayerDoc {
out := new(NetworkLayerDoc)
if layer := packet.NetworkLayer(); layer != nil {
out.LayerType = layer.LayerType().String()
lType := layer.LayerType()
switch {
case lType == layers.LayerTypeIPv6:
out.SrcIP = layer.NetworkFlow().Src().String()
out.DstIP = layer.NetworkFlow().Dst().String()
case lType == layers.LayerTypeIPv4:
out.SrcIP = layer.NetworkFlow().Src().String()
out.DstIP = layer.NetworkFlow().Dst().String()
}
}
return *out
}
type TransportLayerDoc struct {
LayerType string `json:"layer_type"`
SrcPort string `json:"src_port"`
DstPort string `json:"dst_port"`
}
func parseTransportLayer(packet gopacket.Packet) TransportLayerDoc {
out := new(TransportLayerDoc)
if layer := packet.TransportLayer(); layer != nil {
out.LayerType = layer.LayerType().String()
lType := layer.LayerType()
switch {
case lType == layers.LayerTypeTCP:
out.SrcPort = layer.TransportFlow().Src().String()
out.DstPort = layer.TransportFlow().Dst().String()
case lType == layers.LayerTypeUDP:
out.SrcPort = layer.TransportFlow().Src().String()
out.DstPort = layer.TransportFlow().Dst().String()
}
}
return *out
}
type ApplicationLayerDoc struct {
Payload string `json:"payload"`
}
func parseApplicationLayer(packet gopacket.Packet) ApplicationLayerDoc {
out := new(ApplicationLayerDoc)
if app := packet.ApplicationLayer(); app != nil {
logrus.Debug(string(app.Payload()))
out.Payload = string(app.Payload())
}
return *out
}
func handleArpPacket(packet gopacket.Packet) {
arpLayer := packet.Layer(layers.LayerTypeARP)
arp := arpLayer.(*layers.ARP)
out := new(NetworkLayerDoc)
out.LayerType = arp.LayerType().String()
out.Operation = arp.Operation
//out.SrcIP = string()
logrus.Debug(reflect.TypeOf(arp.SourceProtAddress))
logrus.Debug(arp.SourceProtAddress)
logrus.Debug(reflect.TypeOf(arp.SourceHwAddress))
logrus.Debug(arp.SourceHwAddress)
logrus.Debug(out.Operation)
//parseLinkLayer(packet)
}
func handleTCPUDPPacket(packet gopacket.Packet) PacketDocument {
out := new(PacketDocument)
link := parseLinkLayer(packet)
net := parseNetworkLayer(packet)
trans := parseTransportLayer(packet)
app := parseApplicationLayer(packet)
out.Link = link
out.Network = net
out.Transport = trans
out.App = app
return *out
}
func handlePacket(packet gopacket.Packet) PacketDocument {
out := new(PacketDocument)
arpLayer := packet.Layer(layers.LayerTypeARP)
switch {
case arpLayer != nil:
//handleArpPacket(packet)
logrus.Debug("Arp packet")
default:
logrus.Debug("TCP/UDP packet")
out := handleTCPUDPPacket(packet)
return out
}
return *out
}
func insertPackets(packetsIn chan PacketDocument, done chan struct{}, wg *sync.WaitGroup) {
defer wg.Done()
es, err := elasticsearch.NewDefaultClient()
if err != nil {
logrus.Fatal("Error creating the client: %s", err)
panic(err)
}
res, err := es.Info()
if err != nil {
logrus.Fatal("Error getting response: %s", err)
panic(err)
}
logrus.Debug(res)
bi, err := esutil.NewBulkIndexer(esutil.BulkIndexerConfig{
Index: "packet", // The default index name
Client: es, // The Elasticsearch client
NumWorkers: 20, // The number of worker goroutines
FlushBytes: int(5e+6), // The flush threshold in bytes
FlushInterval: 30 * time.Second, // The periodic flush interval
})
if err != nil {
logrus.Fatal("Error creating the indexer: %s", err)
panic(err)
}
for {
select {
case <-done:
return
case data := <-packetsIn:
bytesData, err := json.Marshal(data)
if err != nil {
logrus.Fatal("Cannot encode article %d: %s", err)
}
err = bi.Add(
context.Background(),
esutil.BulkIndexerItem{
// Action field configures the operation to perform (index, create, delete, update)
Action: "index",
// Body is an `io.Reader` with the payload
Body: bytes.NewReader(bytesData),
// OnSuccess is called for each successful operation
OnSuccess: func(ctx context.Context, item esutil.BulkIndexerItem, res esutil.BulkIndexerResponseItem) {
logrus.Debug("Bulk insert success")
},
// OnFailure is called for each failed operation
OnFailure: func(ctx context.Context, item esutil.BulkIndexerItem, res esutil.BulkIndexerResponseItem, err error) {
if err != nil {
logrus.Fatal("ERROR: %s", err)
} else {
logrus.Fatal("ERROR: %s: %s", res.Error.Type, res.Error.Reason)
}
},
},
)
if err != nil {
logrus.Fatal("Unexpected error: %s", err)
}
}
}
}
func iterPackets(packetSource *gopacket.PacketSource) {
var wg sync.WaitGroup
packetsOut := make(chan PacketDocument)
done := make(chan struct{})
wg.Add(1)
go func() {
defer wg.Done()
for packet := range packetSource.Packets() {
packetOut := handlePacket(packet)
packetsOut <- packetOut
}
}()
wg.Add(1)
insertPackets(packetsOut, done, &wg)
}
//Sniff takes ifname and filter string as parameter.
//Packets are decoded and inserted to ES in handlePacket()
func Sniff(ifname, filter string) {
logrus.Debug("Initializing libpcap")
if handle, err := pcap.OpenLive(ifname, 1600, true, pcap.BlockForever); err != nil {
panic(err)
} else if err := handle.SetBPFFilter(filter); err != nil { // optional
logrus.Debug("No filter set or failed to set filter.")
panic(err)
} else {
packetSource := gopacket.NewPacketSource(handle, handle.LinkType())
logrus.Debug("New packet source initialized.")
iterPackets(packetSource)
}
}