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-rw-r--r--vendor/github.com/google/gopacket/dumpcommand/tcpdump.go119
1 files changed, 119 insertions, 0 deletions
diff --git a/vendor/github.com/google/gopacket/dumpcommand/tcpdump.go b/vendor/github.com/google/gopacket/dumpcommand/tcpdump.go
new file mode 100644
index 0000000..2d35722
--- /dev/null
+++ b/vendor/github.com/google/gopacket/dumpcommand/tcpdump.go
@@ -0,0 +1,119 @@
+// Copyright 2012 Google, Inc. All rights reserved.
+//
+// Use of this source code is governed by a BSD-style license
+// that can be found in the LICENSE file in the root of the source
+// tree.
+
+// Package dumpcommand implements a run function for pfdump and pcapdump
+// with many similar flags/features to tcpdump. This code is split out seperate
+// from data sources (pcap/pfring) so it can be used by both.
+package dumpcommand
+
+import (
+ "flag"
+ "fmt"
+ "log"
+ "os"
+ "time"
+
+ "github.com/google/gopacket"
+ "github.com/google/gopacket/ip4defrag"
+ "github.com/google/gopacket/layers" // pulls in all layers decoders
+)
+
+var (
+ print = flag.Bool("print", true, "Print out packets, if false only prints out statistics")
+ maxcount = flag.Int("c", -1, "Only grab this many packets, then exit")
+ decoder = flag.String("decoder", "Ethernet", "Name of the decoder to use")
+ dump = flag.Bool("X", false, "If true, dump very verbose info on each packet")
+ statsevery = flag.Int("stats", 1000, "Output statistics every N packets")
+ printErrors = flag.Bool("errors", false, "Print out packet dumps of decode errors, useful for checking decoders against live traffic")
+ lazy = flag.Bool("lazy", false, "If true, do lazy decoding")
+ defrag = flag.Bool("defrag", false, "If true, do IPv4 defrag")
+)
+
+func Run(src gopacket.PacketDataSource) {
+ if !flag.Parsed() {
+ log.Fatalln("Run called without flags.Parse() being called")
+ }
+ var dec gopacket.Decoder
+ var ok bool
+ if dec, ok = gopacket.DecodersByLayerName[*decoder]; !ok {
+ log.Fatalln("No decoder named", *decoder)
+ }
+ source := gopacket.NewPacketSource(src, dec)
+ source.Lazy = *lazy
+ source.NoCopy = true
+ source.DecodeStreamsAsDatagrams = true
+ fmt.Fprintln(os.Stderr, "Starting to read packets")
+ count := 0
+ bytes := int64(0)
+ start := time.Now()
+ errors := 0
+ truncated := 0
+ layertypes := map[gopacket.LayerType]int{}
+ defragger := ip4defrag.NewIPv4Defragmenter()
+
+ for packet := range source.Packets() {
+ count++
+ bytes += int64(len(packet.Data()))
+
+ // defrag the IPv4 packet if required
+ if *defrag {
+ ip4Layer := packet.Layer(layers.LayerTypeIPv4)
+ if ip4Layer == nil {
+ continue
+ }
+ ip4 := ip4Layer.(*layers.IPv4)
+ l := ip4.Length
+
+ newip4, err := defragger.DefragIPv4(ip4)
+ if err != nil {
+ log.Fatalln("Error while de-fragmenting", err)
+ } else if newip4 == nil {
+ continue // packet fragment, we don't have whole packet yet.
+ }
+ if newip4.Length != l {
+ fmt.Printf("Decoding re-assembled packet: %s\n", newip4.NextLayerType())
+ pb, ok := packet.(gopacket.PacketBuilder)
+ if !ok {
+ panic("Not a PacketBuilder")
+ }
+ nextDecoder := newip4.NextLayerType()
+ nextDecoder.Decode(newip4.Payload, pb)
+ }
+ }
+
+ if *dump {
+ fmt.Println(packet.Dump())
+ } else if *print {
+ fmt.Println(packet)
+ }
+ if !*lazy || *print || *dump { // if we've already decoded all layers...
+ for _, layer := range packet.Layers() {
+ layertypes[layer.LayerType()]++
+ }
+ if packet.Metadata().Truncated {
+ truncated++
+ }
+ if errLayer := packet.ErrorLayer(); errLayer != nil {
+ errors++
+ if *printErrors {
+ fmt.Println("Error:", errLayer.Error())
+ fmt.Println("--- Packet ---")
+ fmt.Println(packet.Dump())
+ }
+ }
+ }
+ done := *maxcount > 0 && count >= *maxcount
+ if count%*statsevery == 0 || done {
+ fmt.Fprintf(os.Stderr, "Processed %v packets (%v bytes) in %v, %v errors and %v truncated packets\n", count, bytes, time.Since(start), errors, truncated)
+ if len(layertypes) > 0 {
+ fmt.Fprintf(os.Stderr, "Layer types seen: %+v\n", layertypes)
+ }
+ }
+ if done {
+ break
+ }
+ }
+}