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         "fmt"
  25         "log"
  26         "net"
  27         "os"
  28         "os/signal"
  29         "time"
  30
  31         "cypherpunks.ru/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         verifierRaw = flag.String("verifier", "", "Verifier")
  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", govpn.MTUDefault, "MTU of TAP interface")
  46         timeoutP    = flag.Int("timeout", 60, "Timeout seconds")
  47         timeSync    = flag.Int("timesync", 0, "Time synchronization requirement")
  48         noisy       = flag.Bool("noise", false, "Enable noise appending")
  49         encless     = flag.Bool("encless", false, "Encryptionless mode")
  50         cpr         = flag.Int("cpr", 0, "Enable constant KiB/sec out traffic rate")
  51         egdPath     = flag.String("egd", "", "Optional path to EGD socket")
  52         syslog      = flag.Bool("syslog", false, "Enable logging to syslog")
  53         warranty    = flag.Bool("warranty", false, "Print warranty information")
  54
  55         conf        *govpn.PeerConf
  56         tap         *govpn.TAP
  57         timeout     int
  58         firstUpCall bool = true
  59         knownPeers  govpn.KnownPeers
  60         idsCache    *govpn.MACCache
  61 )
  62
  63 func main() {
  64         flag.Parse()
  65         if *warranty {
  66                 fmt.Println(govpn.Warranty)
  67                 return
  68         }
  69         timeout = *timeoutP
  70         var err error
  71         log.SetFlags(log.Ldate | log.Lmicroseconds | log.Lshortfile)
  72
  73         if *mtu > govpn.MTUMax {
  74                 log.Fatalln("Maximum allowable MTU is", govpn.MTUMax)
  75         }
  76         if *egdPath != "" {
  77                 log.Println("Using", *egdPath, "EGD")
  78                 govpn.EGDInit(*egdPath)
  79         }
  80
  81         if *verifierRaw == "" {
  82                 log.Fatalln("No verifier specified")
  83         }
  84         verifier, err := govpn.VerifierFromString(*verifierRaw)
  85         if err != nil {
  86                 log.Fatalln(err)
  87         }
  88         key, err := govpn.KeyRead(*keyPath)
  89         if err != nil {
  90                 log.Fatalln("Unable to read the key", err)
  91         }
  92         priv := verifier.PasswordApply(key)
  93         if *encless {
  94                 if *proto != "tcp" {
  95                         log.Fatalln("Currently encryptionless mode works only with TCP")
  96                 }
  97                 *noisy = true
  98         }
  99         conf = &govpn.PeerConf{
 100                 Id:       verifier.Id,
 101                 Iface:    *ifaceName,
 102                 MTU:      *mtu,
 103                 Timeout:  time.Second * time.Duration(timeout),
 104                 TimeSync: *timeSync,
 105                 Noise:    *noisy,
 106                 CPR:      *cpr,
 107                 Encless:  *encless,
 108                 Verifier: verifier,
 109                 DSAPriv:  priv,
 110         }
 111         idsCache = govpn.NewMACCache()
 112         confs := map[govpn.PeerId]*govpn.PeerConf{*verifier.Id: conf}
 113         idsCache.Update(&confs)
 114         log.Println(govpn.VersionGet())
 115
 116         tap, err = govpn.TAPListen(*ifaceName, *mtu)
 117         if err != nil {
 118                 log.Fatalln("Can not listen on TAP interface:", err)
 119         }
 120
 121         if *stats != "" {
 122                 log.Println("Stats are going to listen on", *stats)
 123                 statsPort, err := net.Listen("tcp", *stats)
 124                 if err != nil {
 125                         log.Fatalln("Can not listen on stats port:", err)
 126                 }
 127                 go govpn.StatsProcessor(statsPort, &knownPeers)
 128         }
 129
 130         if *syslog {
 131                 govpn.SyslogEnable()
 132         }
 133
 134         termSignal := make(chan os.Signal, 1)
 135         signal.Notify(termSignal, os.Interrupt, os.Kill)
 136
 137 MainCycle:
 138         for {
 139                 timeouted := make(chan struct{})
 140                 rehandshaking := make(chan struct{})
 141                 termination := make(chan struct{})
 142                 if *proxyAddr != "" {
 143                         *proto = "tcp"
 144                 }
 145                 switch *proto {
 146                 case "udp":
 147                         go startUDP(timeouted, rehandshaking, termination)
 148                 case "tcp":
 149                         if *proxyAddr != "" {
 150                                 go proxyTCP(timeouted, rehandshaking, termination)
 151                         } else {
 152                                 go startTCP(timeouted, rehandshaking, termination)
 153                         }
 154                 default:
 155                         log.Fatalln("Unknown protocol specified")
 156                 }
 157                 select {
 158                 case <-termSignal:
 159                         govpn.BothPrintf(`[finish remote="%s"]`, *remoteAddr)
 160                         termination <- struct{}{}
 161                         break MainCycle
 162                 case <-timeouted:
 163                         break MainCycle
 164                 case <-rehandshaking:
 165                 }
 166                 close(timeouted)
 167                 close(rehandshaking)
 168                 close(termination)
 169         }
 170         govpn.ScriptCall(*downPath, *ifaceName, *remoteAddr)
 171 }