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

   1 /*
   2 GoVPN -- simple secure free software virtual private network daemon
   3 Copyright (C) 2014-2015 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 free software virtual private network 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         ifaceName  = flag.String("iface", "tap0", "TAP network interface")
  36         IDRaw      = flag.String("id", "", "Client identification")
  37         keyPath    = flag.String("key", "", "Path to passphrase file")
  38         upPath     = flag.String("up", "", "Path to up-script")
  39         downPath   = flag.String("down", "", "Path to down-script")
  40         stats      = flag.String("stats", "", "Enable stats retrieving on host:port")
  41         mtu        = flag.Int("mtu", 1452, "MTU for outgoing packets")
  42         timeoutP   = flag.Int("timeout", 60, "Timeout seconds")
  43         noisy      = flag.Bool("noise", false, "Enable noise appending")
  44         cpr        = flag.Int("cpr", 0, "Enable constant KiB/sec out traffic rate")
  45         egdPath    = flag.String("egd", "", "Optional path to EGD socket")
  46 )
  47
  48 func main() {
  49         flag.Parse()
  50         timeout := *timeoutP
  51         var err error
  52         log.SetFlags(log.Ldate | log.Lmicroseconds | log.Lshortfile)
  53
  54         govpn.MTU = *mtu
  55
  56         id, err := govpn.IDDecode(*IDRaw)
  57         if err != nil {
  58                 log.Fatalln(err)
  59         }
  60
  61         if *egdPath != "" {
  62                 log.Println("Using", *egdPath, "EGD")
  63                 govpn.EGDInit(*egdPath)
  64         }
  65
  66         pub, priv := govpn.NewVerifier(id, govpn.StringFromFile(*keyPath))
  67         conf := &govpn.PeerConf{
  68                 Id:          id,
  69                 Timeout:     time.Second * time.Duration(timeout),
  70                 NoiseEnable: *noisy,
  71                 CPR:         *cpr,
  72                 DSAPub:      pub,
  73                 DSAPriv:     priv,
  74         }
  75         govpn.PeersInitDummy(id, conf)
  76
  77         bind, err := net.ResolveUDPAddr("udp", "0.0.0.0:0")
  78         if err != nil {
  79                 log.Fatalln("Can not resolve address:", err)
  80         }
  81         conn, err := net.DialUDP("udp", bind, remote)
  82         if err != nil {
  83                 log.Fatalln("Can not listen on UDP:", err)
  84         }
  85         remote, err := net.ResolveUDPAddr("udp", *remoteAddr)
  86         if err != nil {
  87                 log.Fatalln("Can not resolve remote address:", err)
  88         }
  89
  90         sink := make(chan []byte)
  91         ready := make(chan struct{})
  92         go func() {
  93                 buf := make([]byte, govpn.MTU)
  94                 var n int
  95                 var err error
  96                 for {
  97                         <-ready
  98                         conn.SetReadDeadline(time.Now().Add(time.Second))
  99                         n, err = conn.Read(buf)
 100                         if err != nil {
 101                                 // This is needed for ticking the timeouts counter outside
 102                                 sink <- nil
 103                                 continue
 104                         }
 105                         sink <- buf[:n]
 106                 }
 107         }()
 108         ready <- struct{}{}
 109
 110         tap, ethSink, ethReady, _, err := govpn.TAPListen(
 111                 *ifaceName,
 112                 time.Second*time.Duration(timeout),
 113                 *cpr,
 114         )
 115         if err != nil {
 116                 log.Fatalln("Can not listen on TAP interface:", err)
 117         }
 118
 119         timeouts := 0
 120         firstUpCall := true
 121         var peer *govpn.Peer
 122         var ethPkt []byte
 123         var pkt []byte
 124         knownPeers := govpn.KnownPeers(map[string]**govpn.Peer{remote.String(): &peer})
 125
 126         log.Println(govpn.VersionGet())
 127         log.Println("Max MTU on TAP interface:", govpn.TAPMaxMTU())
 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         termSignal := make(chan os.Signal, 1)
 138         signal.Notify(termSignal, os.Interrupt, os.Kill)
 139
 140         log.Println("Starting handshake")
 141         handshake := govpn.HandshakeStart(remote.String(), conn, conf)
 142
 143 MainCycle:
 144         for {
 145                 if peer != nil && (peer.BytesIn+peer.BytesOut) > govpn.MaxBytesPerKey {
 146                         peer.Zero()
 147                         peer = nil
 148                         handshake = govpn.HandshakeStart(remote.String(), conn, conf)
 149                         log.Println("Rehandshaking")
 150                 }
 151                 select {
 152                 case <-termSignal:
 153                         break MainCycle
 154                 case ethPkt = <-ethSink:
 155                         if peer == nil {
 156                                 if len(ethPkt) > 0 {
 157                                         ethReady <- struct{}{}
 158                                 }
 159                                 continue
 160                         }
 161                         peer.EthProcess(ethPkt, ethReady)
 162                 case pkt = <-sink:
 163                         timeouts++
 164                         if timeouts >= timeout {
 165                                 break MainCycle
 166                         }
 167                         if pkt == nil {
 168                                 ready <- struct{}{}
 169                                 continue
 170                         }
 171
 172                         if peer == nil {
 173                                 if govpn.IDsCache.Find(pkt) == nil {
 174                                         log.Println("Invalid identity in handshake packet")
 175                                         ready <- struct{}{}
 176                                         continue
 177                                 }
 178                                 if p := handshake.Client(pkt); p != nil {
 179                                         log.Println("Handshake completed")
 180                                         if firstUpCall {
 181                                                 go govpn.ScriptCall(*upPath, *ifaceName)
 182                                                 firstUpCall = false
 183                                         }
 184                                         peer = p
 185                                         handshake.Zero()
 186                                         handshake = nil
 187                                 }
 188                                 ready <- struct{}{}
 189                                 continue
 190                         }
 191                         if peer == nil {
 192                                 ready <- struct{}{}
 193                                 continue
 194                         }
 195                         if peer.PktProcess(pkt, tap, ready) {
 196                                 timeouts = 0
 197                         }
 198                 }
 199         }
 200         govpn.ScriptCall(*downPath, *ifaceName)
 201 }