src/cypherpunks.ru/nncp/cmd/nncp-pkt/main.go

   1 /*
   2 NNCP -- Node to Node copy, utilities for store-and-forward data exchange
   3 Copyright (C) 2016-2019 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         "compress/zlib"
  25         "flag"
  26         "fmt"
  27         "io"
  28         "log"
  29         "os"
  30
  31         "cypherpunks.ru/nncp"
  32         "github.com/davecgh/go-xdr/xdr2"
  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 main() {
  44         var (
  45                 overheads  = flag.Bool("overheads", false, "Print packet overheads")
  46                 dump       = flag.Bool("dump", false, "Write decrypted/parsed payload to stdout")
  47                 decompress = flag.Bool("decompress", false, "Try to zlib decompress dumped data")
  48                 cfgPath    = flag.String("cfg", nncp.DefaultCfgPath, "Path to configuration file")
  49                 version    = flag.Bool("version", false, "Print version information")
  50                 warranty   = flag.Bool("warranty", false, "Print warranty information")
  51         )
  52         flag.Usage = usage
  53         flag.Parse()
  54         if *warranty {
  55                 fmt.Println(nncp.Warranty)
  56                 return
  57         }
  58         if *version {
  59                 fmt.Println(nncp.VersionGet())
  60                 return
  61         }
  62
  63         if *overheads {
  64                 fmt.Printf(
  65                         "Plain: %d\nEncrypted: %d\nSize: %d\n",
  66                         nncp.PktOverhead,
  67                         nncp.PktEncOverhead,
  68                         nncp.PktSizeOverhead,
  69                 )
  70                 return
  71         }
  72
  73         var err error
  74         beginning := make([]byte, nncp.PktOverhead)
  75         if _, err = io.ReadFull(os.Stdin, beginning); err != nil {
  76                 log.Fatalln("Not enough data to read")
  77         }
  78         var pkt nncp.Pkt
  79         _, err = xdr.Unmarshal(bytes.NewReader(beginning), &pkt)
  80         if err == nil && pkt.Magic == nncp.MagicNNCPPv2 {
  81                 if *dump {
  82                         bufW := bufio.NewWriter(os.Stdout)
  83                         var r io.Reader
  84                         r = bufio.NewReader(os.Stdin)
  85                         if *decompress {
  86                                 decompressor, err := zlib.NewReader(r)
  87                                 if err != nil {
  88                                         log.Fatalln(err)
  89                                 }
  90                                 r = decompressor
  91                         }
  92                         if _, err = io.Copy(bufW, r); err != nil {
  93                                 log.Fatalln(err)
  94                         }
  95                         if err = bufW.Flush(); err != nil {
  96                                 log.Fatalln(err)
  97                         }
  98                         return
  99                 }
 100                 payloadType := "unknown"
 101                 switch pkt.Type {
 102                 case nncp.PktTypeFile:
 103                         payloadType = "file"
 104                 case nncp.PktTypeFreq:
 105                         payloadType = "file request"
 106                 case nncp.PktTypeExec:
 107                         payloadType = "exec"
 108                 case nncp.PktTypeTrns:
 109                         payloadType = "transitional"
 110                 }
 111                 var path string
 112                 switch pkt.Type {
 113                 case nncp.PktTypeExec:
 114                         path = string(bytes.Replace(
 115                                 pkt.Path[:pkt.PathLen],
 116                                 []byte{0},
 117                                 []byte(" "),
 118                                 -1,
 119                         ))
 120                 case nncp.PktTypeTrns:
 121                         path = nncp.ToBase32(pkt.Path[:pkt.PathLen])
 122                 default:
 123                         path = string(pkt.Path[:pkt.PathLen])
 124                 }
 125                 fmt.Printf(
 126                         "Packet type: plain\nPayload type: %s\nNiceness: %s (%d)\nPath: %s\n",
 127                         payloadType, nncp.NicenessFmt(pkt.Nice), pkt.Nice, path,
 128                 )
 129                 return
 130         }
 131         var pktEnc nncp.PktEnc
 132         _, err = xdr.Unmarshal(bytes.NewReader(beginning), &pktEnc)
 133         if err == nil && pktEnc.Magic == nncp.MagicNNCPEv4 {
 134                 if *dump {
 135                         ctx, err := nncp.CtxFromCmdline(*cfgPath, "", "", false, false)
 136                         if err != nil {
 137                                 log.Fatalln("Error during initialization:", err)
 138                         }
 139                         if ctx.Self == nil {
 140                                 log.Fatalln("Config lacks private keys")
 141                         }
 142                         bufW := bufio.NewWriter(os.Stdout)
 143                         if _, _, err = nncp.PktEncRead(
 144                                 ctx.Self,
 145                                 ctx.Neigh,
 146                                 io.MultiReader(
 147                                         bytes.NewReader(beginning),
 148                                         bufio.NewReader(os.Stdin),
 149                                 ),
 150                                 bufW,
 151                         ); err != nil {
 152                                 log.Fatalln(err)
 153                         }
 154                         if err = bufW.Flush(); err != nil {
 155                                 log.Fatalln(err)
 156                         }
 157                         return
 158                 }
 159                 fmt.Printf(
 160                         "Packet type: encrypted\nNiceness: %s (%d)\nSender: %s\nRecipient: %s\n",
 161                         nncp.NicenessFmt(pktEnc.Nice), pktEnc.Nice, pktEnc.Sender, pktEnc.Recipient,
 162                 )
 163                 return
 164         }
 165         log.Fatalln("Unable to determine packet type")
 166 }