src/cmd/nncp-pkt/main.go

   1 /*
   2 NNCP -- Node to Node copy, utilities for store-and-forward data exchange
   3 Copyright (C) 2016-2023 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/v8"
  33 )
  34
  35 func usage() {
  36         fmt.Fprint(os.Stderr, nncp.UsageHeader())
  37         fmt.Fprint(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         case nncp.PktTypeACK:
  78                 payloadType = "acknowledgement"
  79         }
  80         var path string
  81         switch pkt.Type {
  82         case nncp.PktTypeExec, nncp.PktTypeExecFat:
  83                 path = string(bytes.Replace(
  84                         pkt.Path[:pkt.PathLen], []byte{0}, []byte(" "), -1,
  85                 ))
  86         case nncp.PktTypeTrns:
  87                 path = nncp.Base32Codec.EncodeToString(pkt.Path[:pkt.PathLen])
  88                 node, err := ctx.FindNode(path)
  89                 if err == nil {
  90                         path = fmt.Sprintf("%s (%s)", path, node.Name)
  91                 }
  92         case nncp.PktTypeArea:
  93                 path = nncp.Base32Codec.EncodeToString(pkt.Path[:pkt.PathLen])
  94                 if areaId, err := nncp.AreaIdFromString(path); err == nil {
  95                         path = fmt.Sprintf("%s (%s)", path, ctx.AreaName(areaId))
  96                 }
  97         case nncp.PktTypeACK:
  98                 path = nncp.Base32Codec.EncodeToString(pkt.Path[:pkt.PathLen])
  99         default:
 100                 path = string(pkt.Path[:pkt.PathLen])
 101         }
 102         fmt.Printf(
 103                 "Packet type: plain\nPayload type: %s\nNiceness: %s (%d)\nPath: %s\n",
 104                 payloadType, nncp.NicenessFmt(pkt.Nice), pkt.Nice, path,
 105         )
 106 }
 107
 108 func doEncrypted(
 109         ctx *nncp.Ctx,
 110         pktEnc nncp.PktEnc,
 111         dump bool,
 112         beginning []byte,
 113 ) {
 114         senderName := "unknown"
 115         senderNode := ctx.Neigh[*pktEnc.Sender]
 116         if senderNode != nil {
 117                 senderName = senderNode.Name
 118         }
 119
 120         recipientName := "unknown"
 121         var area *nncp.Area
 122         recipientNode := ctx.Neigh[*pktEnc.Recipient]
 123         if recipientNode == nil {
 124                 area = ctx.AreaId2Area[nncp.AreaId(*pktEnc.Recipient)]
 125                 if area != nil {
 126                         recipientName = "area " + area.Name
 127                 }
 128         } else {
 129                 recipientName = recipientNode.Name
 130         }
 131
 132         if !dump {
 133                 fmt.Printf(`Packet type: encrypted
 134 Niceness: %s (%d)
 135 Sender: %s (%s)
 136 Recipient: %s (%s)
 137 `,
 138                         nncp.NicenessFmt(pktEnc.Nice), pktEnc.Nice,
 139                         pktEnc.Sender, senderName,
 140                         pktEnc.Recipient, recipientName,
 141                 )
 142                 return
 143         }
 144         if ctx.Self == nil {
 145                 log.Fatalln("Config lacks private keys")
 146         }
 147         bufW := bufio.NewWriter(os.Stdout)
 148         var err error
 149         if area == nil {
 150                 _, _, _, err = nncp.PktEncRead(
 151                         ctx.Self, ctx.Neigh,
 152                         io.MultiReader(bytes.NewReader(beginning), bufio.NewReader(os.Stdin)),
 153                         bufW, senderNode != nil, nil,
 154                 )
 155         } else {
 156                 areaNode := nncp.NodeOur{Id: new(nncp.NodeId), ExchPrv: new([32]byte)}
 157                 copy(areaNode.Id[:], area.Id[:])
 158                 copy(areaNode.ExchPrv[:], area.Prv[:])
 159                 _, _, _, err = nncp.PktEncRead(
 160                         &areaNode, ctx.Neigh,
 161                         io.MultiReader(bytes.NewReader(beginning), bufio.NewReader(os.Stdin)),
 162                         bufW, senderNode != nil, nil,
 163                 )
 164         }
 165         if err != nil {
 166                 log.Fatalln(err)
 167         }
 168         if err = bufW.Flush(); err != nil {
 169                 log.Fatalln(err)
 170         }
 171 }
 172
 173 func main() {
 174         var (
 175                 overheads  = flag.Bool("overheads", false, "Print packet overheads")
 176                 dump       = flag.Bool("dump", false, "Write decrypted/parsed payload to stdout")
 177                 decompress = flag.Bool("decompress", false, "Try to zstd decompress dumped data")
 178                 cfgPath    = flag.String("cfg", nncp.DefaultCfgPath, "Path to configuration file")
 179                 version    = flag.Bool("version", false, "Print version information")
 180                 warranty   = flag.Bool("warranty", false, "Print warranty information")
 181         )
 182         log.SetFlags(log.Lshortfile)
 183         flag.Usage = usage
 184         flag.Parse()
 185         if *warranty {
 186                 fmt.Println(nncp.Warranty)
 187                 return
 188         }
 189         if *version {
 190                 fmt.Println(nncp.VersionGet())
 191                 return
 192         }
 193
 194         ctx, err := nncp.CtxFromCmdline(*cfgPath, "", "", false, false, false, false)
 195         if err != nil {
 196                 log.Fatalln("Error during initialization:", err)
 197         }
 198
 199         if *overheads {
 200                 fmt.Printf(
 201                         "Plain: %d\nEncrypted: %d\nSize: %d\n",
 202                         nncp.PktOverhead,
 203                         nncp.PktEncOverhead,
 204                         nncp.PktSizeOverhead,
 205                 )
 206                 return
 207         }
 208
 209         beginning := make([]byte, nncp.PktOverhead)
 210         if _, err := io.ReadFull(os.Stdin, beginning[:nncp.PktEncOverhead]); err != nil {
 211                 log.Fatalln("Not enough data to read")
 212         }
 213         var pktEnc nncp.PktEnc
 214         if _, err := xdr.Unmarshal(bytes.NewReader(beginning), &pktEnc); err == nil {
 215                 switch pktEnc.Magic {
 216                 case nncp.MagicNNCPEv1.B:
 217                         log.Fatalln(nncp.MagicNNCPEv1.TooOld())
 218                 case nncp.MagicNNCPEv2.B:
 219                         log.Fatalln(nncp.MagicNNCPEv2.TooOld())
 220                 case nncp.MagicNNCPEv3.B:
 221                         log.Fatalln(nncp.MagicNNCPEv3.TooOld())
 222                 case nncp.MagicNNCPEv4.B:
 223                         log.Fatalln(nncp.MagicNNCPEv4.TooOld())
 224                 case nncp.MagicNNCPEv5.B:
 225                         log.Fatalln(nncp.MagicNNCPEv5.TooOld())
 226                 case nncp.MagicNNCPEv6.B:
 227                         doEncrypted(ctx, pktEnc, *dump, beginning[:nncp.PktEncOverhead])
 228                         return
 229                 }
 230         }
 231
 232         if _, err := io.ReadFull(os.Stdin, beginning[nncp.PktEncOverhead:]); err != nil {
 233                 log.Fatalln("Not enough data to read")
 234         }
 235         var pkt nncp.Pkt
 236         if _, err := xdr.Unmarshal(bytes.NewReader(beginning), &pkt); err == nil {
 237                 switch pkt.Magic {
 238                 case nncp.MagicNNCPPv1.B:
 239                         log.Fatalln(nncp.MagicNNCPPv1.TooOld())
 240                 case nncp.MagicNNCPPv2.B:
 241                         log.Fatalln(nncp.MagicNNCPPv2.TooOld())
 242                 case nncp.MagicNNCPPv3.B:
 243                         doPlain(ctx, pkt, *dump, *decompress)
 244                         return
 245                 }
 246         }
 247         log.Fatalln("Unable to determine packet type")
 248 }