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-pkt -- parse raw packet\n\n")
  37         fmt.Fprintf(os.Stderr, "Usage: %s [options]\nOptions:\n", os.Args[0])
  38         flag.PrintDefaults()
  39         fmt.Fprintln(os.Stderr, "Packet is read from stdin.")
  40 }
  41
  42 func doPlain(ctx *nncp.Ctx, pkt nncp.Pkt, dump, decompress bool) {
  43         if dump {
  44                 bufW := bufio.NewWriter(os.Stdout)
  45                 var r io.Reader
  46                 r = bufio.NewReader(os.Stdin)
  47                 if decompress {
  48                         decompressor, err := zstd.NewReader(r)
  49                         if err != nil {
  50                                 log.Fatalln(err)
  51                         }
  52                         r = decompressor
  53                 }
  54                 if _, err := io.Copy(bufW, r); err != nil {
  55                         log.Fatalln(err)
  56                 }
  57                 if err := bufW.Flush(); err != nil {
  58                         log.Fatalln(err)
  59                 }
  60                 return
  61         }
  62         payloadType := "unknown"
  63         switch pkt.Type {
  64         case nncp.PktTypeFile:
  65                 payloadType = "file"
  66         case nncp.PktTypeFreq:
  67                 payloadType = "file request"
  68         case nncp.PktTypeExec:
  69                 payloadType = "exec compressed"
  70         case nncp.PktTypeTrns:
  71                 payloadType = "transitional"
  72         case nncp.PktTypeExecFat:
  73                 payloadType = "exec uncompressed"
  74         case nncp.PktTypeArea:
  75                 payloadType = "area"
  76         case nncp.PktTypeACK:
  77                 payloadType = "acknowledgement"
  78         }
  79         var path string
  80         switch pkt.Type {
  81         case nncp.PktTypeExec, nncp.PktTypeExecFat:
  82                 path = string(bytes.Replace(
  83                         pkt.Path[:pkt.PathLen], []byte{0}, []byte(" "), -1,
  84                 ))
  85         case nncp.PktTypeTrns:
  86                 path = nncp.Base32Codec.EncodeToString(pkt.Path[:pkt.PathLen])
  87                 node, err := ctx.FindNode(path)
  88                 if err == nil {
  89                         path = fmt.Sprintf("%s (%s)", path, node.Name)
  90                 }
  91         case nncp.PktTypeArea:
  92                 path = nncp.Base32Codec.EncodeToString(pkt.Path[:pkt.PathLen])
  93                 if areaId, err := nncp.AreaIdFromString(path); err == nil {
  94                         path = fmt.Sprintf("%s (%s)", path, ctx.AreaName(areaId))
  95                 }
  96         case nncp.PktTypeACK:
  97                 path = nncp.Base32Codec.EncodeToString(pkt.Path[:pkt.PathLen])
  98         default:
  99                 path = string(pkt.Path[:pkt.PathLen])
 100         }
 101         fmt.Printf(
 102                 "Packet type: plain\nPayload type: %s\nNiceness: %s (%d)\nPath: %s\n",
 103                 payloadType, nncp.NicenessFmt(pkt.Nice), pkt.Nice, path,
 104         )
 105 }
 106
 107 func doEncrypted(
 108         ctx *nncp.Ctx,
 109         pktEnc nncp.PktEnc,
 110         dump bool,
 111         beginning []byte,
 112 ) {
 113         senderName := "unknown"
 114         senderNode := ctx.Neigh[*pktEnc.Sender]
 115         if senderNode != nil {
 116                 senderName = senderNode.Name
 117         }
 118
 119         recipientName := "unknown"
 120         var area *nncp.Area
 121         recipientNode := ctx.Neigh[*pktEnc.Recipient]
 122         if recipientNode == nil {
 123                 area = ctx.AreaId2Area[nncp.AreaId(*pktEnc.Recipient)]
 124                 if area != nil {
 125                         recipientName = "area " + area.Name
 126                 }
 127         } else {
 128                 recipientName = recipientNode.Name
 129         }
 130
 131         if !dump {
 132                 fmt.Printf(`Packet type: encrypted
 133 Niceness: %s (%d)
 134 Sender: %s (%s)
 135 Recipient: %s (%s)
 136 `,
 137                         nncp.NicenessFmt(pktEnc.Nice), pktEnc.Nice,
 138                         pktEnc.Sender, senderName,
 139                         pktEnc.Recipient, recipientName,
 140                 )
 141                 return
 142         }
 143         if ctx.Self == nil {
 144                 log.Fatalln("Config lacks private keys")
 145         }
 146         bufW := bufio.NewWriter(os.Stdout)
 147         var err error
 148         if area == nil {
 149                 _, _, _, err = nncp.PktEncRead(
 150                         ctx.Self, ctx.Neigh,
 151                         io.MultiReader(bytes.NewReader(beginning), bufio.NewReader(os.Stdin)),
 152                         bufW, senderNode != nil, nil,
 153                 )
 154         } else {
 155                 areaNode := nncp.NodeOur{Id: new(nncp.NodeId), ExchPrv: new([32]byte)}
 156                 copy(areaNode.Id[:], area.Id[:])
 157                 copy(areaNode.ExchPrv[:], area.Prv[:])
 158                 _, _, _, err = nncp.PktEncRead(
 159                         &areaNode, ctx.Neigh,
 160                         io.MultiReader(bytes.NewReader(beginning), bufio.NewReader(os.Stdin)),
 161                         bufW, senderNode != nil, nil,
 162                 )
 163         }
 164         if err != nil {
 165                 log.Fatalln(err)
 166         }
 167         if err = bufW.Flush(); err != nil {
 168                 log.Fatalln(err)
 169         }
 170 }
 171
 172 func main() {
 173         var (
 174                 overheads  = flag.Bool("overheads", false, "Print packet overheads")
 175                 dump       = flag.Bool("dump", false, "Write decrypted/parsed payload to stdout")
 176                 decompress = flag.Bool("decompress", false, "Try to zstd decompress dumped data")
 177                 cfgPath    = flag.String("cfg", nncp.DefaultCfgPath, "Path to configuration file")
 178                 version    = flag.Bool("version", false, "Print version information")
 179                 warranty   = flag.Bool("warranty", false, "Print warranty information")
 180         )
 181         log.SetFlags(log.Lshortfile)
 182         flag.Usage = usage
 183         flag.Parse()
 184         if *warranty {
 185                 fmt.Println(nncp.Warranty)
 186                 return
 187         }
 188         if *version {
 189                 fmt.Println(nncp.VersionGet())
 190                 return
 191         }
 192
 193         ctx, err := nncp.CtxFromCmdline(*cfgPath, "", "", false, false, false, false)
 194         if err != nil {
 195                 log.Fatalln("Error during initialization:", err)
 196         }
 197
 198         if *overheads {
 199                 fmt.Printf(
 200                         "Plain: %d\nEncrypted: %d\nSize: %d\n",
 201                         nncp.PktOverhead,
 202                         nncp.PktEncOverhead,
 203                         nncp.PktSizeOverhead,
 204                 )
 205                 return
 206         }
 207
 208         beginning := make([]byte, nncp.PktOverhead)
 209         if _, err := io.ReadFull(os.Stdin, beginning[:nncp.PktEncOverhead]); err != nil {
 210                 log.Fatalln("Not enough data to read")
 211         }
 212         var pktEnc nncp.PktEnc
 213         if _, err := xdr.Unmarshal(bytes.NewReader(beginning), &pktEnc); err == nil {
 214                 switch pktEnc.Magic {
 215                 case nncp.MagicNNCPEv1.B:
 216                         log.Fatalln(nncp.MagicNNCPEv1.TooOld())
 217                 case nncp.MagicNNCPEv2.B:
 218                         log.Fatalln(nncp.MagicNNCPEv2.TooOld())
 219                 case nncp.MagicNNCPEv3.B:
 220                         log.Fatalln(nncp.MagicNNCPEv3.TooOld())
 221                 case nncp.MagicNNCPEv4.B:
 222                         log.Fatalln(nncp.MagicNNCPEv4.TooOld())
 223                 case nncp.MagicNNCPEv5.B:
 224                         log.Fatalln(nncp.MagicNNCPEv5.TooOld())
 225                 case nncp.MagicNNCPEv6.B:
 226                         doEncrypted(ctx, pktEnc, *dump, beginning[:nncp.PktEncOverhead])
 227                         return
 228                 }
 229         }
 230
 231         if _, err := io.ReadFull(os.Stdin, beginning[nncp.PktEncOverhead:]); err != nil {
 232                 log.Fatalln("Not enough data to read")
 233         }
 234         var pkt nncp.Pkt
 235         if _, err := xdr.Unmarshal(bytes.NewReader(beginning), &pkt); err == nil {
 236                 switch pkt.Magic {
 237                 case nncp.MagicNNCPPv1.B:
 238                         log.Fatalln(nncp.MagicNNCPPv1.TooOld())
 239                 case nncp.MagicNNCPPv2.B:
 240                         log.Fatalln(nncp.MagicNNCPPv2.TooOld())
 241                 case nncp.MagicNNCPPv3.B:
 242                         doPlain(ctx, pkt, *dump, *decompress)
 243                         return
 244                 }
 245         }
 246         log.Fatalln("Unable to determine packet type")
 247 }