cmd/govpn-server/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.
  20 package main
  21
  22 import (
  23         "bytes"
  24         "flag"
  25         "log"
  26         "net"
  27         "os"
  28         "os/signal"
  29         "path"
  30         "time"
  31
  32         "govpn"
  33 )
  34
  35 var (
  36         bindAddr  = flag.String("bind", "[::]:1194", "Bind to address")
  37         peersPath = flag.String("peers", "peers", "Path to peers keys directory")
  38         stats     = flag.String("stats", "", "Enable stats retrieving on host:port")
  39         mtu       = flag.Int("mtu", 1452, "MTU for outgoing packets")
  40         nonceDiff = flag.Int("noncediff", 1, "Allow nonce difference")
  41         timeoutP  = flag.Int("timeout", 60, "Timeout seconds")
  42         noisy     = flag.Bool("noise", false, "Enable noise appending")
  43         cpr        = flag.Int("cpr", 0, "Enable constant KiB/s out traffic rate")
  44 )
  45
  46 type PeerReadyEvent struct {
  47         peer  *govpn.Peer
  48         iface string
  49 }
  50
  51 type PeerState struct {
  52         peer      *govpn.Peer
  53         tap       *govpn.TAP
  54         sink      chan []byte
  55         ready     chan struct{}
  56         terminate chan struct{}
  57 }
  58
  59 func NewPeerState(peer *govpn.Peer, iface string) *PeerState {
  60         tap, sink, ready, terminate, err := govpn.TAPListen(iface)
  61         if err != nil {
  62                 log.Println("Unable to create Eth", err)
  63                 return nil
  64         }
  65         state := PeerState{
  66                 peer:      peer,
  67                 tap:       tap,
  68                 sink:      sink,
  69                 ready:     ready,
  70                 terminate: terminate,
  71         }
  72         return &state
  73 }
  74
  75 type EthEvent struct {
  76         peer  *govpn.Peer
  77         data  []byte
  78         ready chan struct{}
  79 }
  80
  81 func main() {
  82         flag.Parse()
  83         timeout := time.Second * time.Duration(*timeoutP)
  84         var err error
  85         log.SetFlags(log.Ldate | log.Lmicroseconds | log.Lshortfile)
  86
  87         govpn.MTU = *mtu
  88         govpn.Timeout = timeout
  89         govpn.Noncediff = *nonceDiff
  90         govpn.NoiseEnable = *noisy
  91         govpn.CPRInit(*cpr)
  92         govpn.PeersInit(*peersPath)
  93
  94         bind, err := net.ResolveUDPAddr("udp", *bindAddr)
  95         if err != nil {
  96                 panic(err)
  97         }
  98         conn, err := net.ListenUDP("udp", bind)
  99         if err != nil {
 100                 panic(err)
 101         }
 102         udpSink, udpBuf, udpReady := govpn.ConnListen(conn)
 103
 104         termSignal := make(chan os.Signal, 1)
 105         signal.Notify(termSignal, os.Interrupt, os.Kill)
 106
 107         hsHeartbeat := time.Tick(timeout)
 108         go func() { <-hsHeartbeat }()
 109
 110         var addr string
 111         var state *govpn.Handshake
 112         var peerState *PeerState
 113         var peer *govpn.Peer
 114         var exists bool
 115         states := make(map[string]*govpn.Handshake)
 116         peers := make(map[string]*PeerState)
 117         peerReadySink := make(chan PeerReadyEvent)
 118         knownPeers := govpn.KnownPeers(make(map[string]**govpn.Peer))
 119         var peerReady PeerReadyEvent
 120         var udpPkt govpn.UDPPkt
 121         var udpPktData []byte
 122         var ethEvent EthEvent
 123         var peerId *govpn.PeerId
 124         var handshakeProcessForce bool
 125         ethSink := make(chan EthEvent)
 126
 127         log.Println(govpn.VersionGet())
 128         log.Println("Max MTU on TAP interface:", govpn.TAPMaxMTU())
 129         if *stats != "" {
 130                 log.Println("Stats are going to listen on", *stats)
 131                 statsPort, err := net.Listen("tcp", *stats)
 132                 if err != nil {
 133                         panic(err)
 134                 }
 135                 go govpn.StatsProcessor(statsPort, &knownPeers)
 136         }
 137         log.Println("Server started")
 138
 139 MainCycle:
 140         for {
 141                 select {
 142                 case <-termSignal:
 143                         break MainCycle
 144                 case <-hsHeartbeat:
 145                         now := time.Now()
 146                         for addr, hs := range states {
 147                                 if hs.LastPing.Add(timeout).Before(now) {
 148                                         log.Println("Deleting handshake state", addr)
 149                                         hs.Zero()
 150                                         delete(states, addr)
 151                                 }
 152                         }
 153                         for addr, state := range peers {
 154                                 if state.peer.LastPing.Add(timeout).Before(now) {
 155                                         log.Println("Deleting peer", state.peer)
 156                                         delete(peers, addr)
 157                                         delete(knownPeers, addr)
 158                                         downPath := path.Join(
 159                                                 govpn.PeersPath,
 160                                                 state.peer.Id.String(),
 161                                                 "down.sh",
 162                                         )
 163                                         go govpn.ScriptCall(downPath, state.tap.Name)
 164                                         state.terminate <- struct{}{}
 165                                         state.peer.Zero()
 166                                 }
 167                         }
 168                 case peerReady = <-peerReadySink:
 169                         for addr, state := range peers {
 170                                 if state.tap.Name != peerReady.iface {
 171                                         continue
 172                                 }
 173                                 delete(peers, addr)
 174                                 delete(knownPeers, addr)
 175                                 state.terminate <- struct{}{}
 176                                 state.peer.Zero()
 177                                 break
 178                         }
 179                         addr = peerReady.peer.Addr.String()
 180                         state := NewPeerState(peerReady.peer, peerReady.iface)
 181                         if state == nil {
 182                                 continue
 183                         }
 184                         peers[addr] = state
 185                         knownPeers[addr] = &peerReady.peer
 186                         states[addr].Zero()
 187                         delete(states, addr)
 188                         log.Println("Registered interface", peerReady.iface, "with peer", peer)
 189                         go func(state *PeerState) {
 190                                 for data := range state.sink {
 191                                         ethSink <- EthEvent{
 192                                                 peer:  state.peer,
 193                                                 data:  data,
 194                                                 ready: state.ready,
 195                                         }
 196                                 }
 197                         }(state)
 198                 case ethEvent = <-ethSink:
 199                         if s, exists := peers[ethEvent.peer.Addr.String()]; !exists || s.peer != ethEvent.peer {
 200                                 continue
 201                         }
 202                         ethEvent.peer.EthProcess(ethEvent.data, conn, ethEvent.ready)
 203                 case udpPkt = <-udpSink:
 204                         if udpPkt.Addr == nil {
 205                                 udpReady <- struct{}{}
 206                                 continue
 207                         }
 208                         udpPktData = udpBuf[:udpPkt.Size]
 209                         addr = udpPkt.Addr.String()
 210                         handshakeProcessForce = false
 211                 HandshakeProcess:
 212                         if _, exists = peers[addr]; handshakeProcessForce || !exists {
 213                                 peerId = govpn.IDsCache.Find(udpPktData)
 214                                 if peerId == nil {
 215                                         log.Println("Unknown identity from", addr)
 216                                         udpReady <- struct{}{}
 217                                         continue
 218                                 }
 219                                 state, exists = states[addr]
 220                                 if !exists {
 221                                         state = govpn.HandshakeNew(udpPkt.Addr)
 222                                         states[addr] = state
 223                                 }
 224                                 peer = state.Server(peerId, conn, udpPktData)
 225                                 if peer != nil {
 226                                         log.Println("Peer handshake finished", peer)
 227                                         if _, exists = peers[addr]; exists {
 228                                                 go func() {
 229                                                         peerReadySink <- PeerReadyEvent{peer, peers[addr].tap.Name}
 230                                                 }()
 231                                         } else {
 232                                                 go func() {
 233                                                         upPath := path.Join(govpn.PeersPath, peer.Id.String(), "up.sh")
 234                                                         result, err := govpn.ScriptCall(upPath, "")
 235                                                         if err != nil {
 236                                                                 return
 237                                                         }
 238                                                         sepIndex := bytes.Index(result, []byte{'\n'})
 239                                                         if sepIndex < 0 {
 240                                                                 sepIndex = len(result)
 241                                                         }
 242                                                         ifaceName := string(result[:sepIndex])
 243                                                         peerReadySink <- PeerReadyEvent{peer, ifaceName}
 244                                                 }()
 245                                         }
 246                                 }
 247                                 if !handshakeProcessForce {
 248                                         udpReady <- struct{}{}
 249                                 }
 250                                 continue
 251                         }
 252                         peerState, exists = peers[addr]
 253                         if !exists {
 254                                 udpReady <- struct{}{}
 255                                 continue
 256                         }
 257                         // If it fails during processing, then try to work with it
 258                         // as with handshake packet
 259                         if !peerState.peer.UDPProcess(udpPktData, peerState.tap, udpReady) {
 260                                 handshakeProcessForce = true
 261                                 goto HandshakeProcess
 262                         }
 263                 }
 264         }
 265 }