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], []byte{0}, []byte(" "), -1,
  81                 ))
  82         case nncp.PktTypeTrns:
  83                 path = nncp.Base32Codec.EncodeToString(pkt.Path[:pkt.PathLen])
  84         default:
  85                 path = string(pkt.Path[:pkt.PathLen])
  86         }
  87         fmt.Printf(
  88                 "Packet type: plain\nPayload type: %s\nNiceness: %s (%d)\nPath: %s\n",
  89                 payloadType, nncp.NicenessFmt(pkt.Nice), pkt.Nice, path,
  90         )
  91         return
  92 }
  93
  94 func doEncrypted(pktEnc nncp.PktEnc, dump bool, cfgPath string, beginning []byte) {
  95         ctx, err := nncp.CtxFromCmdline(cfgPath, "", "", false, false, false, false)
  96         if err != nil {
  97                 log.Fatalln("Error during initialization:", err)
  98         }
  99         if !dump {
 100                 senderS := "unknown"
 101                 recipientS := "unknown"
 102                 if n, ok := ctx.Neigh[*pktEnc.Sender]; ok {
 103                         senderS = n.Name
 104                 }
 105                 if n, ok := ctx.Neigh[*pktEnc.Recipient]; ok {
 106                         recipientS = n.Name
 107                 }
 108                 fmt.Printf(
 109                         "Packet type: encrypted\nNiceness: %s (%d)\nSender: %s (%s)\nRecipient: %s (%s)\n",
 110                         nncp.NicenessFmt(pktEnc.Nice), pktEnc.Nice,
 111                         pktEnc.Sender, senderS,
 112                         pktEnc.Recipient, recipientS,
 113                 )
 114                 return
 115         }
 116         if ctx.Self == nil {
 117                 log.Fatalln("Config lacks private keys")
 118         }
 119         bufW := bufio.NewWriter(os.Stdout)
 120         if _, _, err = nncp.PktEncRead(
 121                 ctx.Self,
 122                 ctx.Neigh,
 123                 io.MultiReader(
 124                         bytes.NewReader(beginning),
 125                         bufio.NewReader(os.Stdin),
 126                 ),
 127                 bufW,
 128         ); err != nil {
 129                 log.Fatalln(err)
 130         }
 131         if err = bufW.Flush(); err != nil {
 132                 log.Fatalln(err)
 133         }
 134 }
 135
 136 func main() {
 137         var (
 138                 overheads  = flag.Bool("overheads", false, "Print packet overheads")
 139                 dump       = flag.Bool("dump", false, "Write decrypted/parsed payload to stdout")
 140                 decompress = flag.Bool("decompress", false, "Try to zstd decompress dumped data")
 141                 cfgPath    = flag.String("cfg", nncp.DefaultCfgPath, "Path to configuration file")
 142                 version    = flag.Bool("version", false, "Print version information")
 143                 warranty   = flag.Bool("warranty", false, "Print warranty information")
 144         )
 145         log.SetFlags(log.Lshortfile)
 146         flag.Usage = usage
 147         flag.Parse()
 148         if *warranty {
 149                 fmt.Println(nncp.Warranty)
 150                 return
 151         }
 152         if *version {
 153                 fmt.Println(nncp.VersionGet())
 154                 return
 155         }
 156
 157         if *overheads {
 158                 fmt.Printf(
 159                         "Plain: %d\nEncrypted: %d\nSize: %d\n",
 160                         nncp.PktOverhead,
 161                         nncp.PktEncOverhead,
 162                         nncp.PktSizeOverhead,
 163                 )
 164                 return
 165         }
 166
 167         beginning := make([]byte, nncp.PktOverhead)
 168         if _, err := io.ReadFull(os.Stdin, beginning[:nncp.PktEncOverhead]); err != nil {
 169                 log.Fatalln("Not enough data to read")
 170         }
 171         var pktEnc nncp.PktEnc
 172         if _, err := xdr.Unmarshal(bytes.NewReader(beginning), &pktEnc); err == nil {
 173                 switch pktEnc.Magic {
 174                 case nncp.MagicNNCPEv1.B:
 175                         log.Fatalln(nncp.MagicNNCPEv1.TooOld())
 176                 case nncp.MagicNNCPEv2.B:
 177                         log.Fatalln(nncp.MagicNNCPEv2.TooOld())
 178                 case nncp.MagicNNCPEv3.B:
 179                         log.Fatalln(nncp.MagicNNCPEv3.TooOld())
 180                 case nncp.MagicNNCPEv4.B:
 181                         log.Fatalln(nncp.MagicNNCPEv4.TooOld())
 182                 case nncp.MagicNNCPEv5.B:
 183                         doEncrypted(pktEnc, *dump, *cfgPath, beginning[:nncp.PktEncOverhead])
 184                         return
 185                 }
 186         }
 187
 188         if _, err := io.ReadFull(os.Stdin, beginning[nncp.PktEncOverhead:]); err != nil {
 189                 log.Fatalln("Not enough data to read")
 190         }
 191         var pkt nncp.Pkt
 192         if _, err := xdr.Unmarshal(bytes.NewReader(beginning), &pkt); err == nil {
 193                 switch pkt.Magic {
 194                 case nncp.MagicNNCPPv1.B:
 195                         log.Fatalln(nncp.MagicNNCPPv1.TooOld())
 196                 case nncp.MagicNNCPPv2.B:
 197                         log.Fatalln(nncp.MagicNNCPPv2.TooOld())
 198                 case nncp.MagicNNCPPv3.B:
 199                         doPlain(pkt, *dump, *decompress)
 200                         return
 201                 }
 202         }
 203         log.Fatalln("Unable to determine packet type")
 204 }