func main() {
defer util.Run()()
var ring *pfring.Ring
var err error
if ring, err = pfring.NewRing(*iface, uint32(*snaplen), pfring.FlagPromisc); err != nil {
log.Fatalln("pfring ring creation error:", err)
}
if len(flag.Args()) > 0 {
bpffilter := strings.Join(flag.Args(), " ")
fmt.Fprintf(os.Stderr, "Using BPF filter %q\n", bpffilter)
if err = ring.SetBPFFilter(bpffilter); err != nil {
log.Fatalln("BPF filter error:", err)
}
}
if *cluster >= 0 {
if err = ring.SetCluster(*cluster, pfring.ClusterType(*clustertype)); err != nil {
log.Fatalln("pfring SetCluster error:", err)
}
}
if err = ring.SetSocketMode(pfring.ReadOnly); err != nil {
log.Fatalln("pfring SetSocketMode error:", err)
} else if err = ring.Enable(); err != nil {
log.Fatalln("pfring Enable error:", err)
}
dumpcommand.Run(ring)
}
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))
}
}
}
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)
}
func main() {
defer util.Run()()
log.Printf("starting capture on interface %q", *iface)
// Set up pcap packet capture
handle, err := pcap.OpenLive(*iface, int32(*snaplen), true, pcap.BlockForever)
if err != nil {
panic(err)
}
if err := handle.SetBPFFilter(*filter); err != nil {
panic(err)
}
// Set up assembly
streamFactory := &myFactory{bidiMap: make(map[key]*bidi)}
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(timeout / 4)
for {
select {
case packet := <-packets:
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 minute.
log.Println("---- FLUSHING ----")
assembler.FlushOlderThan(time.Now().Add(-timeout))
streamFactory.collectOldStreams()
}
}
}
func main() {
defer util.Run()()
flushDuration, err := time.ParseDuration(*flushAfter)
if err != nil {
log.Fatal("invalid flush duration: ", *flushAfter)
}
log.Printf("starting capture on interface %q", *iface)
// Set up pcap packet capture
handle, err := pcap.OpenLive(*iface, int32(*snaplen), true, flushDuration/2)
if err != nil {
log.Fatal("error opening pcap handle: ", err)
}
if err := handle.SetBPFFilter(*filter); err != nil {
log.Fatal("error setting BPF filter: ", err)
}
// Set up assembly
streamFactory := &statsStreamFactory{}
streamPool := tcpassembly.NewStreamPool(streamFactory)
assembler := tcpassembly.NewAssembler(streamPool)
assembler.MaxBufferedPagesPerConnection = *bufferedPerConnection
assembler.MaxBufferedPagesTotal = *bufferedTotal
log.Println("reading in packets")
// We use a DecodingLayerParser here instead of a simpler PacketSource.
// This approach should be measurably faster, but is also more rigid.
// PacketSource will handle any known type of packet safely and easily,
// but DecodingLayerParser will only handle those packet types we
// specifically pass in. This trade-off can be quite useful, though, in
// high-throughput situations.
var eth layers.Ethernet
var dot1q layers.Dot1Q
var ip4 layers.IPv4
var ip6 layers.IPv6
var ip6extensions layers.IPv6ExtensionSkipper
var tcp layers.TCP
var payload gopacket.Payload
parser := gopacket.NewDecodingLayerParser(layers.LayerTypeEthernet,
ð, &dot1q, &ip4, &ip6, &ip6extensions, &tcp, &payload)
decoded := make([]gopacket.LayerType, 0, 4)
nextFlush := time.Now().Add(flushDuration / 2)
var byteCount int64
start := time.Now()
loop:
for ; *packetCount != 0; *packetCount-- {
// Check to see if we should flush the streams we have
// that haven't seen any new data in a while. Note we set a
// timeout on our PCAP handle, so this should happen even if we
// never see packet data.
if time.Now().After(nextFlush) {
stats, _ := handle.Stats()
log.Printf("flushing all streams that haven't seen packets in the last 2 minutes, pcap stats: %+v", stats)
assembler.FlushOlderThan(time.Now().Add(flushDuration))
nextFlush = time.Now().Add(flushDuration / 2)
}
// To speed things up, we're also using the ZeroCopy method for
// reading packet data. This method is faster than the normal
// ReadPacketData, but the returned bytes in 'data' are
// invalidated by any subsequent ZeroCopyReadPacketData call.
// Note that tcpassembly is entirely compatible with this packet
// reading method. This is another trade-off which might be
// appropriate for high-throughput sniffing: it avoids a packet
// copy, but its cost is much more careful handling of the
// resulting byte slice.
data, ci, err := handle.ZeroCopyReadPacketData()
if err != nil {
log.Printf("error getting packet: %v", err)
continue
}
err = parser.DecodeLayers(data, &decoded)
if err != nil {
log.Printf("error decoding packet: %v", err)
continue
}
if *logAllPackets {
log.Printf("decoded the following layers: %v", decoded)
}
byteCount += int64(len(data))
// Find either the IPv4 or IPv6 address to use as our network
// layer.
foundNetLayer := false
var netFlow gopacket.Flow
for _, typ := range decoded {
switch typ {
case layers.LayerTypeIPv4:
netFlow = ip4.NetworkFlow()
foundNetLayer = true
case layers.LayerTypeIPv6:
netFlow = ip6.NetworkFlow()
foundNetLayer = true
case layers.LayerTypeTCP:
if foundNetLayer {
assembler.AssembleWithTimestamp(netFlow, &tcp, ci.Timestamp)
} else {
log.Println("could not find IPv4 or IPv6 layer, inoring")
}
continue loop
}
}
log.Println("could not find TCP layer")
}
assembler.FlushAll()
log.Printf("processed %d bytes in %v", byteCount, time.Since(start))
}