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