src/cypherpunks.ru/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         "cypherpunks.ru/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         timeSync    = flag.Int("timesync", 0, "Time synchronization requirement")
  47         noisy       = flag.Bool("noise", false, "Enable noise appending")
  48         encless     = flag.Bool("encless", false, "Encryptionless mode")
  49         cpr         = flag.Int("cpr", 0, "Enable constant KiB/sec out traffic rate")
  50         egdPath     = flag.String("egd", "", "Optional path to EGD socket")
  51
  52         conf        *govpn.PeerConf
  53         tap         *govpn.TAP
  54         timeout     int
  55         firstUpCall bool = true
  56         knownPeers  govpn.KnownPeers
  57         idsCache    *govpn.CipherCache
  58 )
  59
  60 func main() {
  61         flag.Parse()
  62         timeout = *timeoutP
  63         var err error
  64         log.SetFlags(log.Ldate | log.Lmicroseconds | log.Lshortfile)
  65
  66         if *mtu > govpn.MTUMax {
  67                 log.Fatalln("Maximum allowable MTU is", govpn.MTUMax)
  68         }
  69         if *egdPath != "" {
  70                 log.Println("Using", *egdPath, "EGD")
  71                 govpn.EGDInit(*egdPath)
  72         }
  73
  74         if *verifierRaw == "" {
  75                 log.Fatalln("No verifier specified")
  76         }
  77         verifier, err := govpn.VerifierFromString(*verifierRaw)
  78         if err != nil {
  79                 log.Fatalln(err)
  80         }
  81         key, err := govpn.KeyRead(*keyPath)
  82         if err != nil {
  83                 log.Fatalln("Unable to read the key", err)
  84         }
  85         priv := verifier.PasswordApply(key)
  86         if *encless {
  87                 if *proto != "tcp" {
  88                         log.Fatalln("Currently encryptionless mode works only with TCP")
  89                 }
  90                 *noisy = true
  91         }
  92         conf = &govpn.PeerConf{
  93                 Id:       verifier.Id,
  94                 Iface:    *ifaceName,
  95                 MTU:      *mtu,
  96                 Timeout:  time.Second * time.Duration(timeout),
  97                 TimeSync: *timeSync,
  98                 Noise:    *noisy,
  99                 CPR:      *cpr,
 100                 Encless:  *encless,
 101                 Verifier: verifier,
 102                 DSAPriv:  priv,
 103         }
 104         idsCache = govpn.NewCipherCache()
 105         confs := map[govpn.PeerId]*govpn.PeerConf{*verifier.Id: conf}
 106         idsCache.Update(&confs)
 107         log.Println(govpn.VersionGet())
 108
 109         tap, err = govpn.TAPListen(*ifaceName, *mtu)
 110         if err != nil {
 111                 log.Fatalln("Can not listen on TAP interface:", err)
 112         }
 113
 114         if *stats != "" {
 115                 log.Println("Stats are going to listen on", *stats)
 116                 statsPort, err := net.Listen("tcp", *stats)
 117                 if err != nil {
 118                         log.Fatalln("Can not listen on stats port:", err)
 119                 }
 120                 go govpn.StatsProcessor(statsPort, &knownPeers)
 121         }
 122
 123         termSignal := make(chan os.Signal, 1)
 124         signal.Notify(termSignal, os.Interrupt, os.Kill)
 125
 126 MainCycle:
 127         for {
 128                 timeouted := make(chan struct{})
 129                 rehandshaking := make(chan struct{})
 130                 termination := make(chan struct{})
 131                 if *proxyAddr != "" {
 132                         *proto = "tcp"
 133                 }
 134                 switch *proto {
 135                 case "udp":
 136                         go startUDP(timeouted, rehandshaking, termination)
 137                 case "tcp":
 138                         if *proxyAddr != "" {
 139                                 go proxyTCP(timeouted, rehandshaking, termination)
 140                         } else {
 141                                 go startTCP(timeouted, rehandshaking, termination)
 142                         }
 143                 default:
 144                         log.Fatalln("Unknown protocol specified")
 145                 }
 146                 select {
 147                 case <-termSignal:
 148                         log.Fatalln("Finishing")
 149                         termination <- struct{}{}
 150                         break MainCycle
 151                 case <-timeouted:
 152                         break MainCycle
 153                 case <-rehandshaking:
 154                 }
 155                 close(timeouted)
 156                 close(rehandshaking)
 157                 close(termination)
 158         }
 159         govpn.ScriptCall(*downPath, *ifaceName)
 160 }