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         noreconnect = flag.Bool("noreconnect", false, "Disable reconnection after timeout")
  49         noisy       = flag.Bool("noise", false, "Enable noise appending")
  50         encless     = flag.Bool("encless", false, "Encryptionless mode")
  51         cpr         = flag.Int("cpr", 0, "Enable constant KiB/sec out traffic rate")
  52         egdPath     = flag.String("egd", "", "Optional path to EGD socket")
  53         syslog      = flag.Bool("syslog", false, "Enable logging to syslog")
  54         warranty    = flag.Bool("warranty", false, "Print warranty information")
  55
  56         conf        *govpn.PeerConf
  57         tap         *govpn.TAP
  58         timeout     int
  59         firstUpCall bool = true
  60         knownPeers  govpn.KnownPeers
  61         idsCache    *govpn.MACCache
  62 )
  63
  64 func main() {
  65         flag.Parse()
  66         if *warranty {
  67                 fmt.Println(govpn.Warranty)
  68                 return
  69         }
  70         timeout = *timeoutP
  71         var err error
  72         log.SetFlags(log.Ldate | log.Lmicroseconds | log.Lshortfile)
  73
  74         if *mtu > govpn.MTUMax {
  75                 log.Fatalln("Maximum allowable MTU is", govpn.MTUMax)
  76         }
  77         if *egdPath != "" {
  78                 log.Println("Using", *egdPath, "EGD")
  79                 govpn.EGDInit(*egdPath)
  80         }
  81
  82         if *proxyAddr != "" {
  83                 *proto = "tcp"
  84         }
  85         if !(*proto == "udp" || *proto == "tcp") {
  86                 log.Fatalln("Unknown protocol specified")
  87         }
  88         if *verifierRaw == "" {
  89                 log.Fatalln("No verifier specified")
  90         }
  91         verifier, err := govpn.VerifierFromString(*verifierRaw)
  92         if err != nil {
  93                 log.Fatalln(err)
  94         }
  95         key, err := govpn.KeyRead(*keyPath)
  96         if err != nil {
  97                 log.Fatalln("Unable to read the key", err)
  98         }
  99         priv := verifier.PasswordApply(key)
 100         if *encless {
 101                 if *proto != "tcp" {
 102                         log.Fatalln("Currently encryptionless mode works only with TCP")
 103                 }
 104                 *noisy = true
 105         }
 106         conf = &govpn.PeerConf{
 107                 Id:       verifier.Id,
 108                 Iface:    *ifaceName,
 109                 MTU:      *mtu,
 110                 Timeout:  time.Second * time.Duration(timeout),
 111                 TimeSync: *timeSync,
 112                 Noise:    *noisy,
 113                 CPR:      *cpr,
 114                 Encless:  *encless,
 115                 Verifier: verifier,
 116                 DSAPriv:  priv,
 117         }
 118         idsCache = govpn.NewMACCache()
 119         confs := map[govpn.PeerId]*govpn.PeerConf{*verifier.Id: conf}
 120         idsCache.Update(&confs)
 121         log.Println(govpn.VersionGet())
 122
 123         tap, err = govpn.TAPListen(*ifaceName, *mtu)
 124         if err != nil {
 125                 log.Fatalln("Can not listen on TAP interface:", err)
 126         }
 127
 128         if *stats != "" {
 129                 log.Println("Stats are going to listen on", *stats)
 130                 statsPort, err := net.Listen("tcp", *stats)
 131                 if err != nil {
 132                         log.Fatalln("Can not listen on stats port:", err)
 133                 }
 134                 go govpn.StatsProcessor(statsPort, &knownPeers)
 135         }
 136
 137         if *syslog {
 138                 govpn.SyslogEnable()
 139         }
 140
 141         termSignal := make(chan os.Signal, 1)
 142         signal.Notify(termSignal, os.Interrupt, os.Kill)
 143
 144 MainCycle:
 145         for {
 146                 timeouted := make(chan struct{})
 147                 rehandshaking := make(chan struct{})
 148                 termination := make(chan struct{})
 149                 switch *proto {
 150                 case "udp":
 151                         go startUDP(timeouted, rehandshaking, termination)
 152                 case "tcp":
 153                         if *proxyAddr != "" {
 154                                 go proxyTCP(timeouted, rehandshaking, termination)
 155                         } else {
 156                                 go startTCP(timeouted, rehandshaking, termination)
 157                         }
 158                 }
 159                 select {
 160                 case <-termSignal:
 161                         govpn.BothPrintf(`[finish remote="%s"]`, *remoteAddr)
 162                         termination <- struct{}{}
 163                         break MainCycle
 164                 case <-timeouted:
 165                         if *noreconnect {
 166                                 break MainCycle
 167                         }
 168                         govpn.BothPrintf(`[sleep seconds="%d"]`, timeout)
 169                         time.Sleep(time.Second * time.Duration(timeout))
 170                 case <-rehandshaking:
 171                 }
 172                 close(timeouted)
 173                 close(rehandshaking)
 174                 close(termination)
 175         }
 176         govpn.ScriptCall(*downPath, *ifaceName, *remoteAddr)
 177 }