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