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

   1 /*
   2 GoVPN -- simple secure free software virtual private network daemon
   3 Copyright (C) 2014-2016 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, DPI/censorship-resistant free software VPN daemon client.
  20 package main
  21
  22 import (
  23         "flag"
  24         "log"
  25         "net"
  26         "os"
  27         "os/signal"
  28         "time"
  29
  30         "govpn"
  31 )
  32
  33 var (
  34         remoteAddr  = flag.String("remote", "", "Remote server address")
  35         proto       = flag.String("proto", "udp", "Protocol to use: udp or tcp")
  36         ifaceName   = flag.String("iface", "tap0", "TAP network interface")
  37         verifierRaw = flag.String("verifier", "", "Verifier")
  38         keyPath     = flag.String("key", "", "Path to passphrase file")
  39         upPath      = flag.String("up", "", "Path to up-script")
  40         downPath    = flag.String("down", "", "Path to down-script")
  41         stats       = flag.String("stats", "", "Enable stats retrieving on host:port")
  42         proxyAddr   = flag.String("proxy", "", "Use HTTP proxy on host:port")
  43         proxyAuth   = flag.String("proxy-auth", "", "user:password Basic proxy auth")
  44         mtu         = flag.Int("mtu", govpn.MTUDefault, "MTU of TAP interface")
  45         timeoutP    = flag.Int("timeout", 60, "Timeout seconds")
  46         noisy       = flag.Bool("noise", false, "Enable noise appending")
  47         encless     = flag.Bool("encless", false, "Encryptionless mode")
  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         conf        *govpn.PeerConf
  52         tap         *govpn.TAP
  53         timeout     int
  54         firstUpCall bool = true
  55         knownPeers  govpn.KnownPeers
  56         idsCache    *govpn.CipherCache
  57 )
  58
  59 func main() {
  60         flag.Parse()
  61         timeout = *timeoutP
  62         var err error
  63         log.SetFlags(log.Ldate | log.Lmicroseconds | log.Lshortfile)
  64
  65         if *mtu > govpn.MTUMax {
  66                 log.Fatalln("Maximum allowable MTU is", govpn.MTUMax)
  67         }
  68         if *egdPath != "" {
  69                 log.Println("Using", *egdPath, "EGD")
  70                 govpn.EGDInit(*egdPath)
  71         }
  72
  73         verifier, err := govpn.VerifierFromString(*verifierRaw)
  74         if err != nil {
  75                 log.Fatalln(err)
  76         }
  77         priv := verifier.PasswordApply(govpn.StringFromFile(*keyPath))
  78         if *encless {
  79                 if *proto != "tcp" {
  80                         log.Fatalln("Currently encryptionless mode works only with TCP")
  81                 }
  82                 *noisy = true
  83         }
  84         conf = &govpn.PeerConf{
  85                 Id:       verifier.Id,
  86                 Iface:    *ifaceName,
  87                 MTU:      *mtu,
  88                 Timeout:  time.Second * time.Duration(timeout),
  89                 Noise:    *noisy,
  90                 CPR:      *cpr,
  91                 Encless:  *encless,
  92                 Verifier: verifier,
  93                 DSAPriv:  priv,
  94         }
  95         idsCache = govpn.NewCipherCache([]govpn.PeerId{*verifier.Id})
  96         log.Println(govpn.VersionGet())
  97
  98         tap, err = govpn.TAPListen(*ifaceName, *mtu)
  99         if err != nil {
 100                 log.Fatalln("Can not listen on TAP interface:", err)
 101         }
 102
 103         if *stats != "" {
 104                 log.Println("Stats are going to listen on", *stats)
 105                 statsPort, err := net.Listen("tcp", *stats)
 106                 if err != nil {
 107                         log.Fatalln("Can not listen on stats port:", err)
 108                 }
 109                 go govpn.StatsProcessor(statsPort, &knownPeers)
 110         }
 111
 112         termSignal := make(chan os.Signal, 1)
 113         signal.Notify(termSignal, os.Interrupt, os.Kill)
 114
 115 MainCycle:
 116         for {
 117                 timeouted := make(chan struct{})
 118                 rehandshaking := make(chan struct{})
 119                 termination := make(chan struct{})
 120                 if *proxyAddr != "" {
 121                         *proto = "tcp"
 122                 }
 123                 switch *proto {
 124                 case "udp":
 125                         go startUDP(timeouted, rehandshaking, termination)
 126                 case "tcp":
 127                         if *proxyAddr != "" {
 128                                 go proxyTCP(timeouted, rehandshaking, termination)
 129                         } else {
 130                                 go startTCP(timeouted, rehandshaking, termination)
 131                         }
 132                 default:
 133                         log.Fatalln("Unknown protocol specified")
 134                 }
 135                 select {
 136                 case <-termSignal:
 137                         log.Fatalln("Finishing")
 138                         termination <- struct{}{}
 139                         break MainCycle
 140                 case <-timeouted:
 141                         break MainCycle
 142                 case <-rehandshaking:
 143                 }
 144                 close(timeouted)
 145                 close(rehandshaking)
 146                 close(termination)
 147         }
 148         govpn.ScriptCall(*downPath, *ifaceName)
 149 }