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", 1500, "MTU")
  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         if *stats != "" {
 125                 log.Println("Stats are going to listen on", *stats)
 126                 statsPort, err := net.Listen("tcp", *stats)
 127                 if err != nil {
 128                         panic(err)
 129                 }
 130                 go govpn.StatsProcessor(statsPort, &knownPeers)
 131         }
 132         log.Println("Server started")
 133
 134 MainCycle:
 135         for {
 136                 select {
 137                 case <-termSignal:
 138                         break MainCycle
 139                 case <-hsHeartbeat:
 140                         now := time.Now()
 141                         for addr, hs := range states {
 142                                 if hs.LastPing.Add(timeout).Before(now) {
 143                                         log.Println("Deleting handshake state", addr)
 144                                         hs.Zero()
 145                                         delete(states, addr)
 146                                 }
 147                         }
 148                         for addr, state := range peers {
 149                                 if state.peer.LastPing.Add(timeout).Before(now) {
 150                                         log.Println("Deleting peer", state.peer)
 151                                         delete(peers, addr)
 152                                         delete(knownPeers, addr)
 153                                         downPath := path.Join(
 154                                                 govpn.PeersPath,
 155                                                 state.peer.Id.String(),
 156                                                 "down.sh",
 157                                         )
 158                                         go govpn.ScriptCall(downPath, state.tap.Name)
 159                                         state.terminate <- struct{}{}
 160                                         state.peer.Zero()
 161                                 }
 162                         }
 163                 case peerReady = <-peerReadySink:
 164                         for addr, state := range peers {
 165                                 if state.tap.Name != peerReady.iface {
 166                                         continue
 167                                 }
 168                                 delete(peers, addr)
 169                                 delete(knownPeers, addr)
 170                                 state.terminate <- struct{}{}
 171                                 state.peer.Zero()
 172                                 break
 173                         }
 174                         addr = peerReady.peer.Addr.String()
 175                         state := NewPeerState(peerReady.peer, peerReady.iface)
 176                         if state == nil {
 177                                 continue
 178                         }
 179                         peers[addr] = state
 180                         knownPeers[addr] = &peerReady.peer
 181                         states[addr].Zero()
 182                         delete(states, addr)
 183                         log.Println("Registered interface", peerReady.iface, "with peer", peer)
 184                         go func(state *PeerState) {
 185                                 for data := range state.sink {
 186                                         ethSink <- EthEvent{
 187                                                 peer:  state.peer,
 188                                                 data:  data,
 189                                                 ready: state.ready,
 190                                         }
 191                                 }
 192                         }(state)
 193                 case ethEvent = <-ethSink:
 194                         if s, exists := peers[ethEvent.peer.Addr.String()]; !exists || s.peer != ethEvent.peer {
 195                                 continue
 196                         }
 197                         ethEvent.peer.EthProcess(ethEvent.data, conn, ethEvent.ready)
 198                 case udpPkt = <-udpSink:
 199                         if udpPkt == nil {
 200                                 udpReady <- struct{}{}
 201                                 continue
 202                         }
 203                         udpPktData = udpBuf[:udpPkt.Size]
 204                         addr = udpPkt.Addr.String()
 205                         handshakeProcessForce = false
 206                 HandshakeProcess:
 207                         if _, exists = peers[addr]; handshakeProcessForce || !exists {
 208                                 peerId = govpn.IDsCache.Find(udpPktData)
 209                                 if peerId == nil {
 210                                         log.Println("Unknown identity from", addr)
 211                                         udpReady <- struct{}{}
 212                                         continue
 213                                 }
 214                                 state, exists = states[addr]
 215                                 if !exists {
 216                                         state = govpn.HandshakeNew(udpPkt.Addr)
 217                                         states[addr] = state
 218                                 }
 219                                 peer = state.Server(peerId, conn, udpPktData)
 220                                 if peer != nil {
 221                                         log.Println("Peer handshake finished", peer)
 222                                         if _, exists = peers[addr]; exists {
 223                                                 go func() {
 224                                                         peerReadySink <- PeerReadyEvent{peer, peers[addr].tap.Name}
 225                                                 }()
 226                                         } else {
 227                                                 go func() {
 228                                                         upPath := path.Join(govpn.PeersPath, peer.Id.String(), "up.sh")
 229                                                         result, err := govpn.ScriptCall(upPath, "")
 230                                                         if err != nil {
 231                                                                 return
 232                                                         }
 233                                                         sepIndex := bytes.Index(result, []byte{'\n'})
 234                                                         if sepIndex < 0 {
 235                                                                 sepIndex = len(result)
 236                                                         }
 237                                                         ifaceName := string(result[:sepIndex])
 238                                                         peerReadySink <- PeerReadyEvent{peer, ifaceName}
 239                                                 }()
 240                                         }
 241                                 }
 242                                 if !handshakeProcessForce {
 243                                         udpReady <- struct{}{}
 244                                 }
 245                                 continue
 246                         }
 247                         peerState, exists = peers[addr]
 248                         if !exists {
 249                                 udpReady <- struct{}{}
 250                                 continue
 251                         }
 252                         // If it fails during processing, then try to work with it
 253                         // as with handshake packet
 254                         if !peerState.peer.UDPProcess(udpPktData, peerState.tap, udpReady) {
 255                                 handshakeProcessForce = true
 256                                 goto HandshakeProcess
 257                         }
 258                 }
 259         }
 260 }