Beispiel #1
0
func main() {
	defer util.Run()()
	var handle *pcap.Handle
	var err error

	// Set up pcap packet capture
	if *fname != "" {
		log.Printf("Reading from pcap dump %q", *fname)
		handle, err = pcap.OpenOffline(*fname)
	} else {
		log.Printf("Starting capture on interface %q", *iface)
		handle, err = pcap.OpenLive(*iface, int32(*snaplen), true, pcap.BlockForever)
	}
	if err != nil {
		log.Fatal(err)
	}

	if err := handle.SetBPFFilter(*filter); err != nil {
		log.Fatal(err)
	}

	// Set up assembly
	streamFactory := &httpStreamFactory{}
	streamPool := tcpassembly.NewStreamPool(streamFactory)
	assembler := tcpassembly.NewAssembler(streamPool)

	log.Println("reading in packets")
	// Read in packets, pass to assembler.
	packetSource := gopacket.NewPacketSource(handle, handle.LinkType())
	packets := packetSource.Packets()
	ticker := time.Tick(time.Minute)
	for {
		select {
		case packet := <-packets:
			// A nil packet indicates the end of a pcap file.
			if packet == nil {
				return
			}
			if *logAllPackets {
				log.Println(packet)
			}
			if packet.NetworkLayer() == nil || packet.TransportLayer() == nil || packet.TransportLayer().LayerType() != layers.LayerTypeTCP {
				log.Println("Unusable packet")
				continue
			}
			tcp := packet.TransportLayer().(*layers.TCP)
			assembler.AssembleWithTimestamp(packet.NetworkLayer().NetworkFlow(), tcp, packet.Metadata().Timestamp)

		case <-ticker:
			// Every minute, flush connections that haven't seen activity in the past 2 minutes.
			assembler.FlushOlderThan(time.Now().Add(time.Minute * -2))
		}
	}
}
Beispiel #2
0
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)
			}
		}
	}
	dumpcommand.Run(handle)
}
Beispiel #3
0
func main() {
	flag.Parse()
	filename := os.TempDir() + string(os.PathSeparator) + "gopacket_benchmark.pcap"
	if _, err := os.Stat(filename); err != nil {
		// This URL points to a publicly available packet data set from a DARPA
		// intrusion detection evaluation.  See
		// http://www.ll.mit.edu/mission/communications/cyber/CSTcorpora/ideval/data/1999/training/week1/index.html
		// for more details.
		fmt.Println("Local pcap file", filename, "doesn't exist, reading from", *url)
		if resp, err := http.Get(*url); err != nil {
			panic(err)
		} else if out, err := os.Create(filename); err != nil {
			panic(err)
		} else if gz, err := gzip.NewReader(resp.Body); err != nil {
			panic(err)
		} else if n, err := io.Copy(out, gz); err != nil {
			panic(err)
		} else if err := gz.Close(); err != nil {
			panic(err)
		} else if err := out.Close(); err != nil {
			panic(err)
		} else {
			fmt.Println("Successfully read", n, "bytes from url, unzipped to local storage")
		}
	}
	fmt.Println("Reading file once through to hopefully cache most of it")
	if f, err := os.Open(filename); err != nil {
		panic(err)
	} else if n, err := io.Copy(ioutil.Discard, f); err != nil {
		panic(err)
	} else if err := f.Close(); err != nil {
		panic(err)
	} else {
		fmt.Println("Read in file", filename, ", total of", n, "bytes")
	}
	if *cpuProfile != "" {
		if cpu, err := os.Create(*cpuProfile); err != nil {
			panic(err)
		} else if err := pprof.StartCPUProfile(cpu); err != nil {
			panic(err)
		} else {
			defer func() {
				pprof.StopCPUProfile()
				cpu.Close()
			}()
		}
	}
	var packetDataSource *BufferPacketSource
	var packetSource *gopacket.PacketSource
	fmt.Printf("Opening file %q for read\n", filename)
	if h, err := pcap.OpenOffline(filename); err != nil {
		panic(err)
	} else {
		fmt.Println("Reading all packets into memory with BufferPacketSource.")
		start := time.Now()
		packetDataSource = NewBufferPacketSource(h)
		duration := time.Since(start)
		fmt.Printf("Time to read packet data into memory from file: %v\n", duration)
		packetSource = gopacket.NewPacketSource(packetDataSource, h.LinkType())
		packetSource.DecodeOptions.Lazy = *decodeLazy
		packetSource.DecodeOptions.NoCopy = *decodeNoCopy
	}
	fmt.Println()
	for i := 0; i < *repeat; i++ {
		packetDataSource.Reset()
		fmt.Printf("Benchmarking decode %d/%d\n", i+1, *repeat)
		benchmarkPacketDecode(packetSource)
	}
	fmt.Println()
	for i := 0; i < *repeat; i++ {
		packetDataSource.Reset()
		fmt.Printf("Benchmarking decoding layer parser %d/%d\n", i+1, *repeat)
		benchmarkLayerDecode(packetDataSource, false)
	}
	fmt.Println()
	for i := 0; i < *repeat; i++ {
		packetDataSource.Reset()
		fmt.Printf("Benchmarking decoding layer parser with assembly %d/%d\n", i+1, *repeat)
		benchmarkLayerDecode(packetDataSource, true)
	}
}