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(ctx *nncp.Ctx, 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.PktTypeTrns:
  72                 payloadType = "transitional"
  73         case nncp.PktTypeExecFat:
  74                 payloadType = "exec uncompressed"
  75         case nncp.PktTypeArea:
  76                 payloadType = "area"
  77         }
  78         var path string
  79         switch pkt.Type {
  80         case nncp.PktTypeExec, nncp.PktTypeExecFat:
  81                 path = string(bytes.Replace(
  82                         pkt.Path[:pkt.PathLen], []byte{0}, []byte(" "), -1,
  83                 ))
  84         case nncp.PktTypeTrns:
  85                 path = nncp.Base32Codec.EncodeToString(pkt.Path[:pkt.PathLen])
  86                 node, err := ctx.FindNode(path)
  87                 if err != nil {
  88                         path = fmt.Sprintf("%s (%s)", path, node.Name)
  89                 }
  90         case nncp.PktTypeArea:
  91                 path = nncp.Base32Codec.EncodeToString(pkt.Path[:pkt.PathLen])
  92                 if areaId, err := nncp.AreaIdFromString(path); err == nil {
  93                         path = fmt.Sprintf("%s (%s)", path, ctx.AreaName(areaId))
  94                 }
  95         default:
  96                 path = string(pkt.Path[:pkt.PathLen])
  97         }
  98         fmt.Printf(
  99                 "Packet type: plain\nPayload type: %s\nNiceness: %s (%d)\nPath: %s\n",
 100                 payloadType, nncp.NicenessFmt(pkt.Nice), pkt.Nice, path,
 101         )
 102         return
 103 }
 104
 105 func doEncrypted(
 106         ctx *nncp.Ctx,
 107         pktEnc nncp.PktEnc,
 108         dump bool,
 109         beginning []byte,
 110 ) {
 111         senderName := "unknown"
 112         senderNode := ctx.Neigh[*pktEnc.Sender]
 113         if senderNode != nil {
 114                 senderName = senderNode.Name
 115         }
 116
 117         recipientName := "unknown"
 118         var area *nncp.Area
 119         recipientNode := ctx.Neigh[*pktEnc.Recipient]
 120         if recipientNode == nil {
 121                 area = ctx.AreaId2Area[nncp.AreaId(*pktEnc.Recipient)]
 122                 recipientName = "area " + area.Name
 123         } else {
 124                 recipientName = recipientNode.Name
 125         }
 126
 127         if !dump {
 128                 fmt.Printf(`Packet type: encrypted
 129 Niceness: %s (%d)
 130 Sender: %s (%s)
 131 Recipient: %s (%s)
 132 `,
 133                         nncp.NicenessFmt(pktEnc.Nice), pktEnc.Nice,
 134                         pktEnc.Sender, senderName,
 135                         pktEnc.Recipient, recipientName,
 136                 )
 137                 return
 138         }
 139         if ctx.Self == nil {
 140                 log.Fatalln("Config lacks private keys")
 141         }
 142         bufW := bufio.NewWriter(os.Stdout)
 143         var err error
 144         if area == nil {
 145                 _, _, _, err = nncp.PktEncRead(
 146                         ctx.Self, ctx.Neigh,
 147                         io.MultiReader(bytes.NewReader(beginning), bufio.NewReader(os.Stdin)),
 148                         bufW, senderNode != nil, nil,
 149                 )
 150         } else {
 151                 areaNode := nncp.NodeOur{Id: new(nncp.NodeId), ExchPrv: new([32]byte)}
 152                 copy(areaNode.Id[:], area.Id[:])
 153                 copy(areaNode.ExchPrv[:], area.Prv[:])
 154                 _, _, _, err = nncp.PktEncRead(
 155                         &areaNode, ctx.Neigh,
 156                         io.MultiReader(bytes.NewReader(beginning), bufio.NewReader(os.Stdin)),
 157                         bufW, senderNode != nil, nil,
 158                 )
 159         }
 160         if err != nil {
 161                 log.Fatalln(err)
 162         }
 163         if err = bufW.Flush(); err != nil {
 164                 log.Fatalln(err)
 165         }
 166 }
 167
 168 func main() {
 169         var (
 170                 overheads  = flag.Bool("overheads", false, "Print packet overheads")
 171                 dump       = flag.Bool("dump", false, "Write decrypted/parsed payload to stdout")
 172                 decompress = flag.Bool("decompress", false, "Try to zstd decompress dumped data")
 173                 cfgPath    = flag.String("cfg", nncp.DefaultCfgPath, "Path to configuration file")
 174                 version    = flag.Bool("version", false, "Print version information")
 175                 warranty   = flag.Bool("warranty", false, "Print warranty information")
 176         )
 177         log.SetFlags(log.Lshortfile)
 178         flag.Usage = usage
 179         flag.Parse()
 180         if *warranty {
 181                 fmt.Println(nncp.Warranty)
 182                 return
 183         }
 184         if *version {
 185                 fmt.Println(nncp.VersionGet())
 186                 return
 187         }
 188
 189         ctx, err := nncp.CtxFromCmdline(*cfgPath, "", "", false, false, false, false)
 190         if err != nil {
 191                 log.Fatalln("Error during initialization:", err)
 192         }
 193
 194         if *overheads {
 195                 fmt.Printf(
 196                         "Plain: %d\nEncrypted: %d\nSize: %d\n",
 197                         nncp.PktOverhead,
 198                         nncp.PktEncOverhead,
 199                         nncp.PktSizeOverhead,
 200                 )
 201                 return
 202         }
 203
 204         beginning := make([]byte, nncp.PktOverhead)
 205         if _, err := io.ReadFull(os.Stdin, beginning[:nncp.PktEncOverhead]); err != nil {
 206                 log.Fatalln("Not enough data to read")
 207         }
 208         var pktEnc nncp.PktEnc
 209         if _, err := xdr.Unmarshal(bytes.NewReader(beginning), &pktEnc); err == nil {
 210                 switch pktEnc.Magic {
 211                 case nncp.MagicNNCPEv1.B:
 212                         log.Fatalln(nncp.MagicNNCPEv1.TooOld())
 213                 case nncp.MagicNNCPEv2.B:
 214                         log.Fatalln(nncp.MagicNNCPEv2.TooOld())
 215                 case nncp.MagicNNCPEv3.B:
 216                         log.Fatalln(nncp.MagicNNCPEv3.TooOld())
 217                 case nncp.MagicNNCPEv4.B:
 218                         log.Fatalln(nncp.MagicNNCPEv4.TooOld())
 219                 case nncp.MagicNNCPEv5.B:
 220                         doEncrypted(ctx, pktEnc, *dump, beginning[:nncp.PktEncOverhead])
 221                         return
 222                 }
 223         }
 224
 225         if _, err := io.ReadFull(os.Stdin, beginning[nncp.PktEncOverhead:]); err != nil {
 226                 log.Fatalln("Not enough data to read")
 227         }
 228         var pkt nncp.Pkt
 229         if _, err := xdr.Unmarshal(bytes.NewReader(beginning), &pkt); err == nil {
 230                 switch pkt.Magic {
 231                 case nncp.MagicNNCPPv1.B:
 232                         log.Fatalln(nncp.MagicNNCPPv1.TooOld())
 233                 case nncp.MagicNNCPPv2.B:
 234                         log.Fatalln(nncp.MagicNNCPPv2.TooOld())
 235                 case nncp.MagicNNCPPv3.B:
 236                         doPlain(ctx, pkt, *dump, *decompress)
 237                         return
 238                 }
 239         }
 240         log.Fatalln("Unable to determine packet type")
 241 }