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) 2016-2018 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, either version 3 of the License, or
   8 (at your option) any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17 */
  18
  19 // Parse raw NNCP packet
  20 package main
  21
  22 import (
  23         "bufio"
  24         "bytes"
  25         "compress/zlib"
  26         "flag"
  27         "fmt"
  28         "io"
  29         "log"
  30         "os"
  31
  32         "cypherpunks.ru/nncp"
  33         "github.com/davecgh/go-xdr/xdr2"
  34         "golang.org/x/crypto/blake2b"
  35 )
  36
  37 func usage() {
  38         fmt.Fprintf(os.Stderr, nncp.UsageHeader())
  39         fmt.Fprintf(os.Stderr, "nncp-pkt -- parse raw packet\n\n")
  40         fmt.Fprintf(os.Stderr, "Usage: %s [options]\nOptions:\n", os.Args[0])
  41         flag.PrintDefaults()
  42         fmt.Fprintln(os.Stderr, "Packet is read from stdin.")
  43 }
  44
  45 func main() {
  46         var (
  47                 dump       = flag.Bool("dump", false, "Write decrypted/parsed payload to stdout")
  48                 decompress = flag.Bool("decompress", false, "Try to zlib decompress dumped data")
  49                 cfgPath    = flag.String("cfg", nncp.DefaultCfgPath, "Path to configuration file")
  50                 version    = flag.Bool("version", false, "Print version information")
  51                 warranty   = flag.Bool("warranty", false, "Print warranty information")
  52         )
  53         flag.Usage = usage
  54         flag.Parse()
  55         if *warranty {
  56                 fmt.Println(nncp.Warranty)
  57                 return
  58         }
  59         if *version {
  60                 fmt.Println(nncp.VersionGet())
  61                 return
  62         }
  63
  64         var err error
  65         beginning := make([]byte, nncp.PktOverhead-8-2*blake2b.Size256)
  66         if _, err = io.ReadFull(os.Stdin, beginning); err != nil {
  67                 log.Fatalln("Not enough data to read")
  68         }
  69         var pkt nncp.Pkt
  70         _, err = xdr.Unmarshal(bytes.NewReader(beginning), &pkt)
  71         if err == nil && pkt.Magic == nncp.MagicNNCPPv2 {
  72                 if *dump {
  73                         bufW := bufio.NewWriter(os.Stdout)
  74                         var r io.Reader
  75                         r = bufio.NewReader(os.Stdin)
  76                         if *decompress {
  77                                 decompressor, err := zlib.NewReader(r)
  78                                 if err != nil {
  79                                         log.Fatalln(err)
  80                                 }
  81                                 r = decompressor
  82                         }
  83                         if _, err = io.Copy(bufW, r); err != nil {
  84                                 log.Fatalln(err)
  85                         }
  86                         if err = bufW.Flush(); err != nil {
  87                                 log.Fatalln(err)
  88                         }
  89                         return
  90                 }
  91                 payloadType := "unknown"
  92                 switch pkt.Type {
  93                 case nncp.PktTypeFile:
  94                         payloadType = "file"
  95                 case nncp.PktTypeFreq:
  96                         payloadType = "file request"
  97                 case nncp.PktTypeExec:
  98                         payloadType = "exec"
  99                 case nncp.PktTypeTrns:
 100                         payloadType = "transitional"
 101                 }
 102                 var path string
 103                 switch pkt.Type {
 104                 case nncp.PktTypeExec:
 105                         path = string(bytes.Replace(
 106                                 pkt.Path[:pkt.PathLen],
 107                                 []byte{0},
 108                                 []byte(" "),
 109                                 -1,
 110                         ))
 111                 case nncp.PktTypeTrns:
 112                         path = nncp.ToBase32(pkt.Path[:pkt.PathLen])
 113                 default:
 114                         path = string(pkt.Path[:pkt.PathLen])
 115                 }
 116                 fmt.Printf(
 117                         "Packet type: plain\nPayload type: %s\nNiceness: %d\nPath: %s\n",
 118                         payloadType, pkt.Nice, path,
 119                 )
 120                 return
 121         }
 122         var pktEnc nncp.PktEnc
 123         _, err = xdr.Unmarshal(bytes.NewReader(beginning), &pktEnc)
 124         if err == nil && pktEnc.Magic == nncp.MagicNNCPEv3 {
 125                 if *dump {
 126                         ctx, err := nncp.CtxFromCmdline(*cfgPath, "", "", false, false)
 127                         if err != nil {
 128                                 log.Fatalln("Error during initialization:", err)
 129                         }
 130                         if ctx.Self == nil {
 131                                 log.Fatalln("Config lacks private keys")
 132                         }
 133                         bufW := bufio.NewWriter(os.Stdout)
 134                         if _, _, err = nncp.PktEncRead(
 135                                 ctx.Self,
 136                                 ctx.Neigh,
 137                                 io.MultiReader(
 138                                         bytes.NewReader(beginning),
 139                                         bufio.NewReader(os.Stdin),
 140                                 ),
 141                                 bufW,
 142                         ); err != nil {
 143                                 log.Fatalln(err)
 144                         }
 145                         if err = bufW.Flush(); err != nil {
 146                                 log.Fatalln(err)
 147                         }
 148                         return
 149                 }
 150                 fmt.Printf(
 151                         "Packet type: encrypted\nNiceness: %d\nSender: %s\nRecipient: %s\n",
 152                         pktEnc.Nice, pktEnc.Sender, pktEnc.Recipient,
 153                 )
 154                 return
 155         }
 156         log.Fatalln("Unable to determine packet type")
 157 }