src/cmd/nncp-pkt/main.go

   1 /*
   2 NNCP -- Node to Node copy, utilities for store-and-forward data exchange
   3 Copyright (C) 2016-2022 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.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         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         return
 107 }
 108
 109 func doEncrypted(
 110         ctx *nncp.Ctx,
 111         pktEnc nncp.PktEnc,
 112         dump bool,
 113         beginning []byte,
 114 ) {
 115         senderName := "unknown"
 116         senderNode := ctx.Neigh[*pktEnc.Sender]
 117         if senderNode != nil {
 118                 senderName = senderNode.Name
 119         }
 120
 121         recipientName := "unknown"
 122         var area *nncp.Area
 123         recipientNode := ctx.Neigh[*pktEnc.Recipient]
 124         if recipientNode == nil {
 125                 area = ctx.AreaId2Area[nncp.AreaId(*pktEnc.Recipient)]
 126                 if area != nil {
 127                         recipientName = "area " + area.Name
 128                 }
 129         } else {
 130                 recipientName = recipientNode.Name
 131         }
 132
 133         if !dump {
 134                 fmt.Printf(`Packet type: encrypted
 135 Niceness: %s (%d)
 136 Sender: %s (%s)
 137 Recipient: %s (%s)
 138 `,
 139                         nncp.NicenessFmt(pktEnc.Nice), pktEnc.Nice,
 140                         pktEnc.Sender, senderName,
 141                         pktEnc.Recipient, recipientName,
 142                 )
 143                 return
 144         }
 145         if ctx.Self == nil {
 146                 log.Fatalln("Config lacks private keys")
 147         }
 148         bufW := bufio.NewWriter(os.Stdout)
 149         var err error
 150         if area == nil {
 151                 _, _, _, err = nncp.PktEncRead(
 152                         ctx.Self, ctx.Neigh,
 153                         io.MultiReader(bytes.NewReader(beginning), bufio.NewReader(os.Stdin)),
 154                         bufW, senderNode != nil, nil,
 155                 )
 156         } else {
 157                 areaNode := nncp.NodeOur{Id: new(nncp.NodeId), ExchPrv: new([32]byte)}
 158                 copy(areaNode.Id[:], area.Id[:])
 159                 copy(areaNode.ExchPrv[:], area.Prv[:])
 160                 _, _, _, err = nncp.PktEncRead(
 161                         &areaNode, ctx.Neigh,
 162                         io.MultiReader(bytes.NewReader(beginning), bufio.NewReader(os.Stdin)),
 163                         bufW, senderNode != nil, nil,
 164                 )
 165         }
 166         if err != nil {
 167                 log.Fatalln(err)
 168         }
 169         if err = bufW.Flush(); err != nil {
 170                 log.Fatalln(err)
 171         }
 172 }
 173
 174 func main() {
 175         var (
 176                 overheads  = flag.Bool("overheads", false, "Print packet overheads")
 177                 dump       = flag.Bool("dump", false, "Write decrypted/parsed payload to stdout")
 178                 decompress = flag.Bool("decompress", false, "Try to zstd decompress dumped data")
 179                 cfgPath    = flag.String("cfg", nncp.DefaultCfgPath, "Path to configuration file")
 180                 version    = flag.Bool("version", false, "Print version information")
 181                 warranty   = flag.Bool("warranty", false, "Print warranty information")
 182         )
 183         log.SetFlags(log.Lshortfile)
 184         flag.Usage = usage
 185         flag.Parse()
 186         if *warranty {
 187                 fmt.Println(nncp.Warranty)
 188                 return
 189         }
 190         if *version {
 191                 fmt.Println(nncp.VersionGet())
 192                 return
 193         }
 194
 195         ctx, err := nncp.CtxFromCmdline(*cfgPath, "", "", false, false, false, false)
 196         if err != nil {
 197                 log.Fatalln("Error during initialization:", err)
 198         }
 199
 200         if *overheads {
 201                 fmt.Printf(
 202                         "Plain: %d\nEncrypted: %d\nSize: %d\n",
 203                         nncp.PktOverhead,
 204                         nncp.PktEncOverhead,
 205                         nncp.PktSizeOverhead,
 206                 )
 207                 return
 208         }
 209
 210         beginning := make([]byte, nncp.PktOverhead)
 211         if _, err := io.ReadFull(os.Stdin, beginning[:nncp.PktEncOverhead]); err != nil {
 212                 log.Fatalln("Not enough data to read")
 213         }
 214         var pktEnc nncp.PktEnc
 215         if _, err := xdr.Unmarshal(bytes.NewReader(beginning), &pktEnc); err == nil {
 216                 switch pktEnc.Magic {
 217                 case nncp.MagicNNCPEv1.B:
 218                         log.Fatalln(nncp.MagicNNCPEv1.TooOld())
 219                 case nncp.MagicNNCPEv2.B:
 220                         log.Fatalln(nncp.MagicNNCPEv2.TooOld())
 221                 case nncp.MagicNNCPEv3.B:
 222                         log.Fatalln(nncp.MagicNNCPEv3.TooOld())
 223                 case nncp.MagicNNCPEv4.B:
 224                         log.Fatalln(nncp.MagicNNCPEv4.TooOld())
 225                 case nncp.MagicNNCPEv5.B:
 226                         log.Fatalln(nncp.MagicNNCPEv5.TooOld())
 227                 case nncp.MagicNNCPEv6.B:
 228                         doEncrypted(ctx, pktEnc, *dump, beginning[:nncp.PktEncOverhead])
 229                         return
 230                 }
 231         }
 232
 233         if _, err := io.ReadFull(os.Stdin, beginning[nncp.PktEncOverhead:]); err != nil {
 234                 log.Fatalln("Not enough data to read")
 235         }
 236         var pkt nncp.Pkt
 237         if _, err := xdr.Unmarshal(bytes.NewReader(beginning), &pkt); err == nil {
 238                 switch pkt.Magic {
 239                 case nncp.MagicNNCPPv1.B:
 240                         log.Fatalln(nncp.MagicNNCPPv1.TooOld())
 241                 case nncp.MagicNNCPPv2.B:
 242                         log.Fatalln(nncp.MagicNNCPPv2.TooOld())
 243                 case nncp.MagicNNCPPv3.B:
 244                         doPlain(ctx, pkt, *dump, *decompress)
 245                         return
 246                 }
 247         }
 248         log.Fatalln("Unable to determine packet type")
 249 }