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 *proxyAddr != "" {
  82                 *proto = "tcp"
  83         }
  84         if !(*proto == "udp" || *proto == "tcp") {
  85                 log.Fatalln("Unknown protocol specified")
  86         }
  87         if *verifierRaw == "" {
  88                 log.Fatalln("No verifier specified")
  89         }
  90         verifier, err := govpn.VerifierFromString(*verifierRaw)
  91         if err != nil {
  92                 log.Fatalln(err)
  93         }
  94         key, err := govpn.KeyRead(*keyPath)
  95         if err != nil {
  96                 log.Fatalln("Unable to read the key", err)
  97         }
  98         priv := verifier.PasswordApply(key)
  99         if *encless {
 100                 if *proto != "tcp" {
 101                         log.Fatalln("Currently encryptionless mode works only with TCP")
 102                 }
 103                 *noisy = true
 104         }
 105         conf = &govpn.PeerConf{
 106                 Id:       verifier.Id,
 107                 Iface:    *ifaceName,
 108                 MTU:      *mtu,
 109                 Timeout:  time.Second * time.Duration(timeout),
 110                 TimeSync: *timeSync,
 111                 Noise:    *noisy,
 112                 CPR:      *cpr,
 113                 Encless:  *encless,
 114                 Verifier: verifier,
 115                 DSAPriv:  priv,
 116         }
 117         idsCache = govpn.NewMACCache()
 118         confs := map[govpn.PeerId]*govpn.PeerConf{*verifier.Id: conf}
 119         idsCache.Update(&confs)
 120         log.Println(govpn.VersionGet())
 121
 122         tap, err = govpn.TAPListen(*ifaceName, *mtu)
 123         if err != nil {
 124                 log.Fatalln("Can not listen on TAP interface:", err)
 125         }
 126
 127         if *stats != "" {
 128                 log.Println("Stats are going to listen on", *stats)
 129                 statsPort, err := net.Listen("tcp", *stats)
 130                 if err != nil {
 131                         log.Fatalln("Can not listen on stats port:", err)
 132                 }
 133                 go govpn.StatsProcessor(statsPort, &knownPeers)
 134         }
 135
 136         if *syslog {
 137                 govpn.SyslogEnable()
 138         }
 139
 140         termSignal := make(chan os.Signal, 1)
 141         signal.Notify(termSignal, os.Interrupt, os.Kill)
 142
 143 MainCycle:
 144         for {
 145                 timeouted := make(chan struct{})
 146                 rehandshaking := make(chan struct{})
 147                 termination := make(chan struct{})
 148                 switch *proto {
 149                 case "udp":
 150                         go startUDP(timeouted, rehandshaking, termination)
 151                 case "tcp":
 152                         if *proxyAddr != "" {
 153                                 go proxyTCP(timeouted, rehandshaking, termination)
 154                         } else {
 155                                 go startTCP(timeouted, rehandshaking, termination)
 156                         }
 157                 }
 158                 select {
 159                 case <-termSignal:
 160                         govpn.BothPrintf(`[finish remote="%s"]`, *remoteAddr)
 161                         termination <- struct{}{}
 162                         break MainCycle
 163                 case <-timeouted:
 164                         govpn.BothPrintf(`[sleep seconds="%d"]`, timeout)
 165                         time.Sleep(time.Second * time.Duration(timeout))
 166                 case <-rehandshaking:
 167                 }
 168                 close(timeouted)
 169                 close(rehandshaking)
 170                 close(termination)
 171         }
 172         govpn.ScriptCall(*downPath, *ifaceName, *remoteAddr)
 173 }