src/cmd/nncp-pkt/main.go

   1 /*
   2 NNCP -- Node to Node copy, utilities for store-and-forward data exchange
   3 Copyright (C) 2016-2021 Sergey Matveev <stargrave@stargrave.org>
   4
   5 This program is free software: you can redistribute it and/or modify
   6 it under the terms of the GNU General Public License as published by
   7 the Free Software Foundation, version 3 of the License.
   8
   9 This program is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 GNU General Public License for more details.
  13
  14 You should have received a copy of the GNU General Public License
  15 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16 */
  17
  18 // Parse raw NNCP packet.
  19 package main
  20
  21 import (
  22         "bufio"
  23         "bytes"
  24         "flag"
  25         "fmt"
  26         "io"
  27         "log"
  28         "os"
  29
  30         xdr "github.com/davecgh/go-xdr/xdr2"
  31         "github.com/klauspost/compress/zstd"
  32         "go.cypherpunks.ru/nncp/v7"
  33 )
  34
  35 func usage() {
  36         fmt.Fprintf(os.Stderr, nncp.UsageHeader())
  37         fmt.Fprintf(os.Stderr, "nncp-pkt -- parse raw packet\n\n")
  38         fmt.Fprintf(os.Stderr, "Usage: %s [options]\nOptions:\n", os.Args[0])
  39         flag.PrintDefaults()
  40         fmt.Fprintln(os.Stderr, "Packet is read from stdin.")
  41 }
  42
  43 func doPlain(pkt nncp.Pkt, dump, decompress bool) {
  44         if dump {
  45                 bufW := bufio.NewWriter(os.Stdout)
  46                 var r io.Reader
  47                 r = bufio.NewReader(os.Stdin)
  48                 if decompress {
  49                         decompressor, err := zstd.NewReader(r)
  50                         if err != nil {
  51                                 log.Fatalln(err)
  52                         }
  53                         r = decompressor
  54                 }
  55                 if _, err := io.Copy(bufW, r); err != nil {
  56                         log.Fatalln(err)
  57                 }
  58                 if err := bufW.Flush(); err != nil {
  59                         log.Fatalln(err)
  60                 }
  61                 return
  62         }
  63         payloadType := "unknown"
  64         switch pkt.Type {
  65         case nncp.PktTypeFile:
  66                 payloadType = "file"
  67         case nncp.PktTypeFreq:
  68                 payloadType = "file request"
  69         case nncp.PktTypeExec:
  70                 payloadType = "exec compressed"
  71         case nncp.PktTypeExecFat:
  72                 payloadType = "exec uncompressed"
  73         case nncp.PktTypeTrns:
  74                 payloadType = "transitional"
  75         }
  76         var path string
  77         switch pkt.Type {
  78         case nncp.PktTypeExec, nncp.PktTypeExecFat:
  79                 path = string(bytes.Replace(
  80                         pkt.Path[:pkt.PathLen],
  81                         []byte{0},
  82                         []byte(" "),
  83                         -1,
  84                 ))
  85         case nncp.PktTypeTrns:
  86                 path = nncp.Base32Codec.EncodeToString(pkt.Path[:pkt.PathLen])
  87         default:
  88                 path = string(pkt.Path[:pkt.PathLen])
  89         }
  90         fmt.Printf(
  91                 "Packet type: plain\nPayload type: %s\nNiceness: %s (%d)\nPath: %s\n",
  92                 payloadType, nncp.NicenessFmt(pkt.Nice), pkt.Nice, path,
  93         )
  94         return
  95 }
  96
  97 func doEncrypted(pktEnc nncp.PktEnc, dump bool, cfgPath string, beginning []byte) {
  98         if !dump {
  99                 fmt.Printf(
 100                         "Packet type: encrypted\nNiceness: %s (%d)\nSender: %s\nRecipient: %s\n",
 101                         nncp.NicenessFmt(pktEnc.Nice), pktEnc.Nice, pktEnc.Sender, pktEnc.Recipient,
 102                 )
 103                 return
 104         }
 105         ctx, err := nncp.CtxFromCmdline(cfgPath, "", "", false, false, false, false)
 106         if err != nil {
 107                 log.Fatalln("Error during initialization:", err)
 108         }
 109         if ctx.Self == nil {
 110                 log.Fatalln("Config lacks private keys")
 111         }
 112         bufW := bufio.NewWriter(os.Stdout)
 113         if _, _, err = nncp.PktEncRead(
 114                 ctx.Self,
 115                 ctx.Neigh,
 116                 io.MultiReader(
 117                         bytes.NewReader(beginning),
 118                         bufio.NewReader(os.Stdin),
 119                 ),
 120                 bufW,
 121         ); err != nil {
 122                 log.Fatalln(err)
 123         }
 124         if err = bufW.Flush(); err != nil {
 125                 log.Fatalln(err)
 126         }
 127 }
 128
 129 func main() {
 130         var (
 131                 overheads  = flag.Bool("overheads", false, "Print packet overheads")
 132                 dump       = flag.Bool("dump", false, "Write decrypted/parsed payload to stdout")
 133                 decompress = flag.Bool("decompress", false, "Try to zstd decompress dumped data")
 134                 cfgPath    = flag.String("cfg", nncp.DefaultCfgPath, "Path to configuration file")
 135                 version    = flag.Bool("version", false, "Print version information")
 136                 warranty   = flag.Bool("warranty", false, "Print warranty information")
 137         )
 138         log.SetFlags(log.Lshortfile)
 139         flag.Usage = usage
 140         flag.Parse()
 141         if *warranty {
 142                 fmt.Println(nncp.Warranty)
 143                 return
 144         }
 145         if *version {
 146                 fmt.Println(nncp.VersionGet())
 147                 return
 148         }
 149
 150         if *overheads {
 151                 fmt.Printf(
 152                         "Plain: %d\nEncrypted: %d\nSize: %d\n",
 153                         nncp.PktOverhead,
 154                         nncp.PktEncOverhead,
 155                         nncp.PktSizeOverhead,
 156                 )
 157                 return
 158         }
 159
 160         beginning := make([]byte, nncp.PktOverhead)
 161         if _, err := io.ReadFull(os.Stdin, beginning); err != nil {
 162                 log.Fatalln("Not enough data to read")
 163         }
 164         var pkt nncp.Pkt
 165         if _, err := xdr.Unmarshal(bytes.NewReader(beginning), &pkt); err == nil {
 166                 switch pkt.Magic {
 167                 case nncp.MagicNNCPPv1.B:
 168                         log.Fatalln(nncp.MagicNNCPPv1.TooOld())
 169                 case nncp.MagicNNCPPv2.B:
 170                         log.Fatalln(nncp.MagicNNCPPv2.TooOld())
 171                 case nncp.MagicNNCPPv3.B:
 172                         doPlain(pkt, *dump, *decompress)
 173                         return
 174                 }
 175         }
 176         var pktEnc nncp.PktEnc
 177         if _, err := xdr.Unmarshal(bytes.NewReader(beginning), &pktEnc); err == nil {
 178                 switch pkt.Magic {
 179                 case nncp.MagicNNCPEv1.B:
 180                         log.Fatalln(nncp.MagicNNCPEv1.TooOld())
 181                 case nncp.MagicNNCPEv2.B:
 182                         log.Fatalln(nncp.MagicNNCPEv2.TooOld())
 183                 case nncp.MagicNNCPEv3.B:
 184                         log.Fatalln(nncp.MagicNNCPEv3.TooOld())
 185                 case nncp.MagicNNCPEv4.B:
 186                         log.Fatalln(nncp.MagicNNCPEv4.TooOld())
 187                 case nncp.MagicNNCPEv5.B:
 188                         doEncrypted(pktEnc, *dump, *cfgPath, beginning)
 189                         return
 190                 }
 191         }
 192         log.Fatalln("Unable to determine packet type")
 193 }