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) 2016-2017 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         "io/ioutil"
  30         "log"
  31         "os"
  32
  33         "cypherpunks.ru/nncp"
  34         "github.com/davecgh/go-xdr/xdr2"
  35         "golang.org/x/crypto/blake2b"
  36 )
  37
  38 func usage() {
  39         fmt.Fprintf(os.Stderr, nncp.UsageHeader())
  40         fmt.Fprintln(os.Stderr, "nncp-pkt -- parse raw packet\n")
  41         fmt.Fprintf(os.Stderr, "Usage: %s [options]\nOptions:\n", os.Args[0])
  42         flag.PrintDefaults()
  43         fmt.Fprintln(os.Stderr, "Packet is read from stdin.")
  44 }
  45
  46 func main() {
  47         var (
  48                 dump       = flag.Bool("dump", false, "Write decrypted/parsed payload to stdout")
  49                 decompress = flag.Bool("decompress", false, "Try to zlib decompress dumped data")
  50                 cfgPath    = flag.String("cfg", nncp.DefaultCfgPath, "Path to configuration file")
  51                 version    = flag.Bool("version", false, "Print version information")
  52                 warranty   = flag.Bool("warranty", false, "Print warranty information")
  53         )
  54         flag.Usage = usage
  55         flag.Parse()
  56         if *warranty {
  57                 fmt.Println(nncp.Warranty)
  58                 return
  59         }
  60         if *version {
  61                 fmt.Println(nncp.VersionGet())
  62                 return
  63         }
  64
  65         var err error
  66         beginning := make([]byte, nncp.PktOverhead-8-2*blake2b.Size256)
  67         if _, err = io.ReadFull(os.Stdin, beginning); err != nil {
  68                 log.Fatalln("Not enough data to read")
  69         }
  70         var pkt nncp.Pkt
  71         _, err = xdr.Unmarshal(bytes.NewReader(beginning), &pkt)
  72         if err == nil && pkt.Magic == nncp.MagicNNCPPv1 {
  73                 if *dump {
  74                         bufW := bufio.NewWriter(os.Stdout)
  75                         var r io.Reader
  76                         r = bufio.NewReader(os.Stdin)
  77                         if *decompress {
  78                                 decompressor, err := zlib.NewReader(r)
  79                                 if err != nil {
  80                                         log.Fatalln(err)
  81                                 }
  82                                 r = decompressor
  83                         }
  84                         if _, err = io.Copy(bufW, r); err != nil {
  85                                 log.Fatalln(err)
  86                         }
  87                         if err = bufW.Flush(); err != nil {
  88                                 log.Fatalln(err)
  89                         }
  90                         return
  91                 }
  92                 payloadType := "unknown"
  93                 switch pkt.Type {
  94                 case nncp.PktTypeFile:
  95                         payloadType = "file"
  96                 case nncp.PktTypeFreq:
  97                         payloadType = "file request"
  98                 case nncp.PktTypeMail:
  99                         payloadType = "mail"
 100                 case nncp.PktTypeTrns:
 101                         payloadType = "transitional"
 102                 }
 103                 var path string
 104                 switch pkt.Type {
 105                 case nncp.PktTypeTrns:
 106                         path = nncp.ToBase32(pkt.Path[:pkt.PathLen])
 107                 default:
 108                         path = string(pkt.Path[:pkt.PathLen])
 109                 }
 110                 fmt.Printf("Packet type: plain\nPayload type: %s\nPath: %s\n", payloadType, path)
 111                 return
 112         }
 113         var pktEnc nncp.PktEnc
 114         _, err = xdr.Unmarshal(bytes.NewReader(beginning), &pktEnc)
 115         if err == nil && pktEnc.Magic == nncp.MagicNNCPEv1 {
 116                 if *dump {
 117                         cfgRaw, err := ioutil.ReadFile(nncp.CfgPathFromEnv(cfgPath))
 118                         if err != nil {
 119                                 log.Fatalln("Can not read config:", err)
 120                         }
 121                         ctx, err := nncp.CfgParse(cfgRaw)
 122                         if err != nil {
 123                                 log.Fatalln("Can not parse config:", err)
 124                         }
 125                         bufW := bufio.NewWriter(os.Stdout)
 126                         if _, _, err = nncp.PktEncRead(
 127                                 ctx.Self,
 128                                 ctx.Neigh,
 129                                 io.MultiReader(
 130                                         bytes.NewReader(beginning),
 131                                         bufio.NewReader(os.Stdin),
 132                                 ),
 133                                 bufW,
 134                         ); err != nil {
 135                                 log.Fatalln(err)
 136                         }
 137                         if err = bufW.Flush(); err != nil {
 138                                 log.Fatalln(err)
 139                         }
 140                         return
 141                 }
 142                 fmt.Printf(
 143                         "Packet type: encrypted\nNiceness: %d\nSender: %s\n",
 144                         pktEnc.Nice, pktEnc.Sender,
 145                 )
 146                 return
 147         }
 148         log.Fatalln("Unable to determine packet type")
 149 }