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         proxyAddr  = flag.String("proxy", "", "Use HTTP proxy on host:port")
  44         proxyAuth  = flag.String("proxy-auth", "", "user:password Basic proxy auth")
  45         mtu        = flag.Int("mtu", 1452, "MTU for outgoing packets")
  46         timeoutP   = flag.Int("timeout", 60, "Timeout seconds")
  47         noisy      = flag.Bool("noise", false, "Enable noise appending")
  48         cpr        = flag.Int("cpr", 0, "Enable constant KiB/sec out traffic rate")
  49         egdPath    = flag.String("egd", "", "Optional path to EGD socket")
  50 )
  51
  52 func main() {
  53         flag.Parse()
  54         timeout := *timeoutP
  55         var err error
  56         log.SetFlags(log.Ldate | log.Lmicroseconds | log.Lshortfile)
  57
  58         govpn.MTU = *mtu
  59
  60         id, err := govpn.IDDecode(*IDRaw)
  61         if err != nil {
  62                 log.Fatalln(err)
  63         }
  64
  65         if *egdPath != "" {
  66                 log.Println("Using", *egdPath, "EGD")
  67                 govpn.EGDInit(*egdPath)
  68         }
  69
  70         pub, priv := govpn.NewVerifier(id, govpn.StringFromFile(*keyPath))
  71         conf := &govpn.PeerConf{
  72                 Id:          id,
  73                 Timeout:     time.Second * time.Duration(timeout),
  74                 NoiseEnable: *noisy,
  75                 CPR:         *cpr,
  76                 DSAPub:      pub,
  77                 DSAPriv:     priv,
  78         }
  79         govpn.PeersInitDummy(id, conf)
  80
  81         var conn io.Writer
  82         var sink chan []byte
  83         var ready chan struct{}
  84         switch *proto {
  85         case "udp":
  86                 conn, sink, ready = startUDP()
  87         case "tcp":
  88                 if *proxyAddr != "" {
  89                         conn, sink, ready = proxyTCP()
  90                 } else {
  91                         conn, sink, ready = startTCP()
  92                 }
  93         default:
  94                 log.Fatalln("Unknown protocol specified")
  95         }
  96
  97         tap, ethSink, ethReady, _, err := govpn.TAPListen(
  98                 *ifaceName,
  99                 time.Second*time.Duration(timeout),
 100                 *cpr,
 101         )
 102         if err != nil {
 103                 log.Fatalln("Can not listen on TAP interface:", err)
 104         }
 105
 106         timeouts := 0
 107         firstUpCall := true
 108         var peer *govpn.Peer
 109         var ethPkt []byte
 110         var pkt []byte
 111         knownPeers := govpn.KnownPeers(map[string]**govpn.Peer{*remoteAddr: &peer})
 112
 113         log.Println(govpn.VersionGet())
 114         log.Println("Connected to", *proto, *remoteAddr)
 115         log.Println("Max MTU on TAP interface:", govpn.TAPMaxMTU())
 116         if *stats != "" {
 117                 log.Println("Stats are going to listen on", *stats)
 118                 statsPort, err := net.Listen("tcp", *stats)
 119                 if err != nil {
 120                         log.Fatalln("Can not listen on stats port:", err)
 121                 }
 122                 go govpn.StatsProcessor(statsPort, &knownPeers)
 123         }
 124
 125         termSignal := make(chan os.Signal, 1)
 126         signal.Notify(termSignal, os.Interrupt, os.Kill)
 127
 128         log.Println("Starting handshake")
 129         handshake := govpn.HandshakeStart(*remoteAddr, conn, conf)
 130
 131 MainCycle:
 132         for {
 133                 if peer != nil && (peer.BytesIn+peer.BytesOut) > govpn.MaxBytesPerKey {
 134                         peer.Zero()
 135                         peer = nil
 136                         handshake = govpn.HandshakeStart(*remoteAddr, conn, conf)
 137                         log.Println("Rehandshaking")
 138                 }
 139                 select {
 140                 case <-termSignal:
 141                         break MainCycle
 142                 case ethPkt = <-ethSink:
 143                         if peer == nil {
 144                                 if len(ethPkt) > 0 {
 145                                         ethReady <- struct{}{}
 146                                 }
 147                                 continue
 148                         }
 149                         peer.EthProcess(ethPkt, ethReady)
 150                 case pkt = <-sink:
 151                         timeouts++
 152                         if timeouts >= timeout {
 153                                 break MainCycle
 154                         }
 155                         if pkt == nil {
 156                                 ready <- struct{}{}
 157                                 continue
 158                         }
 159
 160                         if peer == nil {
 161                                 if govpn.IDsCache.Find(pkt) == nil {
 162                                         log.Println("Invalid identity in handshake packet")
 163                                         ready <- struct{}{}
 164                                         continue
 165                                 }
 166                                 if p := handshake.Client(pkt); p != nil {
 167                                         log.Println("Handshake completed")
 168                                         if firstUpCall {
 169                                                 go govpn.ScriptCall(*upPath, *ifaceName)
 170                                                 firstUpCall = false
 171                                         }
 172                                         peer = p
 173                                         handshake.Zero()
 174                                         handshake = nil
 175                                 }
 176                                 ready <- struct{}{}
 177                                 continue
 178                         }
 179                         if peer == nil {
 180                                 ready <- struct{}{}
 181                                 continue
 182                         }
 183                         if peer.PktProcess(pkt, tap, ready) {
 184                                 timeouts = 0
 185                         }
 186                 }
 187         }
 188         govpn.ScriptCall(*downPath, *ifaceName)
 189 }