src/govpn/cmd/govpn-client/main.go

   1 /*
   2 GoVPN -- simple secure free software virtual private network daemon
   3 Copyright (C) 2014-2015 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 // Simple secure free software virtual private network daemon client.
  20 package main
  21
  22 import (
  23         "flag"
  24         "io"
  25         "log"
  26         "net"
  27         "os"
  28         "os/signal"
  29         "time"
  30
  31         "govpn"
  32 )
  33
  34 var (
  35         remoteAddr = flag.String("remote", "", "Remote server address")
  36         proto      = flag.String("proto", "udp", "Protocol to use: udp or tcp")
  37         ifaceName  = flag.String("iface", "tap0", "TAP network interface")
  38         IDRaw      = flag.String("id", "", "Client identification")
  39         keyPath    = flag.String("key", "", "Path to passphrase file")
  40         upPath     = flag.String("up", "", "Path to up-script")
  41         downPath   = flag.String("down", "", "Path to down-script")
  42         stats      = flag.String("stats", "", "Enable stats retrieving on host:port")
  43         mtu        = flag.Int("mtu", 1452, "MTU for outgoing packets")
  44         timeoutP   = flag.Int("timeout", 60, "Timeout seconds")
  45         noisy      = flag.Bool("noise", false, "Enable noise appending")
  46         cpr        = flag.Int("cpr", 0, "Enable constant KiB/sec out traffic rate")
  47         egdPath    = flag.String("egd", "", "Optional path to EGD socket")
  48 )
  49
  50 func main() {
  51         flag.Parse()
  52         timeout := *timeoutP
  53         var err error
  54         log.SetFlags(log.Ldate | log.Lmicroseconds | log.Lshortfile)
  55
  56         govpn.MTU = *mtu
  57
  58         id, err := govpn.IDDecode(*IDRaw)
  59         if err != nil {
  60                 log.Fatalln(err)
  61         }
  62
  63         if *egdPath != "" {
  64                 log.Println("Using", *egdPath, "EGD")
  65                 govpn.EGDInit(*egdPath)
  66         }
  67
  68         pub, priv := govpn.NewVerifier(id, govpn.StringFromFile(*keyPath))
  69         conf := &govpn.PeerConf{
  70                 Id:          id,
  71                 Timeout:     time.Second * time.Duration(timeout),
  72                 NoiseEnable: *noisy,
  73                 CPR:         *cpr,
  74                 DSAPub:      pub,
  75                 DSAPriv:     priv,
  76         }
  77         govpn.PeersInitDummy(id, conf)
  78
  79         var conn io.Writer
  80         var sink chan []byte
  81         var ready chan struct{}
  82         switch *proto {
  83         case "udp":
  84                 conn, sink, ready = startUDP()
  85         case "tcp":
  86                 conn, sink, ready = startTCP()
  87         default:
  88                 log.Fatalln("Unknown protocol specified")
  89         }
  90
  91         tap, ethSink, ethReady, _, err := govpn.TAPListen(
  92                 *ifaceName,
  93                 time.Second*time.Duration(timeout),
  94                 *cpr,
  95         )
  96         if err != nil {
  97                 log.Fatalln("Can not listen on TAP interface:", err)
  98         }
  99
 100         timeouts := 0
 101         firstUpCall := true
 102         var peer *govpn.Peer
 103         var ethPkt []byte
 104         var pkt []byte
 105         knownPeers := govpn.KnownPeers(map[string]**govpn.Peer{*remoteAddr: &peer})
 106
 107         log.Println(govpn.VersionGet())
 108         log.Println("Connected to", *proto, *remoteAddr)
 109         log.Println("Max MTU on TAP interface:", govpn.TAPMaxMTU())
 110         if *stats != "" {
 111                 log.Println("Stats are going to listen on", *stats)
 112                 statsPort, err := net.Listen("tcp", *stats)
 113                 if err != nil {
 114                         log.Fatalln("Can not listen on stats port:", err)
 115                 }
 116                 go govpn.StatsProcessor(statsPort, &knownPeers)
 117         }
 118
 119         termSignal := make(chan os.Signal, 1)
 120         signal.Notify(termSignal, os.Interrupt, os.Kill)
 121
 122         log.Println("Starting handshake")
 123         handshake := govpn.HandshakeStart(*remoteAddr, conn, conf)
 124
 125 MainCycle:
 126         for {
 127                 if peer != nil && (peer.BytesIn+peer.BytesOut) > govpn.MaxBytesPerKey {
 128                         peer.Zero()
 129                         peer = nil
 130                         handshake = govpn.HandshakeStart(*remoteAddr, conn, conf)
 131                         log.Println("Rehandshaking")
 132                 }
 133                 select {
 134                 case <-termSignal:
 135                         break MainCycle
 136                 case ethPkt = <-ethSink:
 137                         if peer == nil {
 138                                 if len(ethPkt) > 0 {
 139                                         ethReady <- struct{}{}
 140                                 }
 141                                 continue
 142                         }
 143                         peer.EthProcess(ethPkt, ethReady)
 144                 case pkt = <-sink:
 145                         timeouts++
 146                         if timeouts >= timeout {
 147                                 break MainCycle
 148                         }
 149                         if pkt == nil {
 150                                 ready <- struct{}{}
 151                                 continue
 152                         }
 153
 154                         if peer == nil {
 155                                 if govpn.IDsCache.Find(pkt) == nil {
 156                                         log.Println("Invalid identity in handshake packet")
 157                                         ready <- struct{}{}
 158                                         continue
 159                                 }
 160                                 if p := handshake.Client(pkt); p != nil {
 161                                         log.Println("Handshake completed")
 162                                         if firstUpCall {
 163                                                 go govpn.ScriptCall(*upPath, *ifaceName)
 164                                                 firstUpCall = false
 165                                         }
 166                                         peer = p
 167                                         handshake.Zero()
 168                                         handshake = nil
 169                                 }
 170                                 ready <- struct{}{}
 171                                 continue
 172                         }
 173                         if peer == nil {
 174                                 ready <- struct{}{}
 175                                 continue
 176                         }
 177                         if peer.PktProcess(pkt, tap, ready) {
 178                                 timeouts = 0
 179                         }
 180                 }
 181         }
 182         govpn.ScriptCall(*downPath, *ifaceName)
 183 }