src/govpn/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         "io"
  26         "log"
  27         "net"
  28         "os"
  29         "os/signal"
  30         "path"
  31         "time"
  32
  33         "govpn"
  34 )
  35
  36 var (
  37         bindAddr  = flag.String("bind", "[::]:1194", "Bind to address")
  38         proto     = flag.String("proto", "udp", "Protocol to use: udp or tcp")
  39         peersPath = flag.String("peers", "peers", "Path to peers keys directory")
  40         stats     = flag.String("stats", "", "Enable stats retrieving on host:port")
  41         mtu       = flag.Int("mtu", 1452, "MTU for outgoing packets")
  42         egdPath   = flag.String("egd", "", "Optional path to EGD socket")
  43 )
  44
  45 type Pkt struct {
  46         addr  string
  47         conn  io.Writer
  48         data  []byte
  49         ready chan struct{}
  50 }
  51
  52 type PeerReadyEvent struct {
  53         peer  *govpn.Peer
  54         iface string
  55 }
  56
  57 type PeerState struct {
  58         peer      *govpn.Peer
  59         tap       *govpn.TAP
  60         sink      chan []byte
  61         ready     chan struct{}
  62         terminate chan struct{}
  63 }
  64
  65 func NewPeerState(peer *govpn.Peer, iface string) *PeerState {
  66         tap, sink, ready, terminate, err := govpn.TAPListen(iface, peer.Timeout, peer.CPR)
  67         if err != nil {
  68                 log.Println("Unable to create Eth", err)
  69                 return nil
  70         }
  71         state := PeerState{
  72                 peer:      peer,
  73                 tap:       tap,
  74                 sink:      sink,
  75                 ready:     ready,
  76                 terminate: terminate,
  77         }
  78         return &state
  79 }
  80
  81 type EthEvent struct {
  82         peer  *govpn.Peer
  83         data  []byte
  84         ready chan struct{}
  85 }
  86
  87 func main() {
  88         flag.Parse()
  89         timeout := time.Second * time.Duration(govpn.TimeoutDefault)
  90         log.SetFlags(log.Ldate | log.Lmicroseconds | log.Lshortfile)
  91
  92         govpn.MTU = *mtu
  93         govpn.PeersInit(*peersPath)
  94
  95         if *egdPath != "" {
  96                 log.Println("Using", *egdPath, "EGD")
  97                 govpn.EGDInit(*egdPath)
  98         }
  99
 100         var sink chan Pkt
 101         switch *proto {
 102         case "udp":
 103                 sink = startUDP()
 104         case "tcp":
 105                 sink = startTCP()
 106         default:
 107                 log.Fatalln("Unknown protocol specified")
 108         }
 109
 110         termSignal := make(chan os.Signal, 1)
 111         signal.Notify(termSignal, os.Interrupt, os.Kill)
 112
 113         hsHeartbeat := time.Tick(timeout)
 114         go func() { <-hsHeartbeat }()
 115
 116         var state *govpn.Handshake
 117         var peerState *PeerState
 118         var peer *govpn.Peer
 119         var exists bool
 120         states := make(map[string]*govpn.Handshake)
 121         peers := make(map[string]*PeerState)
 122         peerReadySink := make(chan PeerReadyEvent)
 123         knownPeers := govpn.KnownPeers(make(map[string]**govpn.Peer))
 124         var peerReady PeerReadyEvent
 125         var pkt Pkt
 126         var ethEvent EthEvent
 127         var peerId *govpn.PeerId
 128         var peerConf *govpn.PeerConf
 129         var handshakeProcessForce bool
 130         ethSink := make(chan EthEvent)
 131
 132         log.Println(govpn.VersionGet())
 133         log.Println("Listening on", *proto, *bindAddr)
 134         log.Println("Max MTU on TAP interface:", govpn.TAPMaxMTU())
 135         if *stats != "" {
 136                 log.Println("Stats are going to listen on", *stats)
 137                 statsPort, err := net.Listen("tcp", *stats)
 138                 if err != nil {
 139                         log.Fatalln("Can not listen on stats port:", err)
 140                 }
 141                 go govpn.StatsProcessor(statsPort, &knownPeers)
 142         }
 143         log.Println("Server started")
 144
 145 MainCycle:
 146         for {
 147                 select {
 148                 case <-termSignal:
 149                         break MainCycle
 150                 case <-hsHeartbeat:
 151                         now := time.Now()
 152                         for addr, hs := range states {
 153                                 if hs.LastPing.Add(timeout).Before(now) {
 154                                         log.Println("Deleting handshake state", addr)
 155                                         hs.Zero()
 156                                         delete(states, addr)
 157                                 }
 158                         }
 159                         for addr, state := range peers {
 160                                 if state.peer.LastPing.Add(timeout).Before(now) {
 161                                         log.Println("Deleting peer", state.peer)
 162                                         delete(peers, addr)
 163                                         delete(knownPeers, addr)
 164                                         downPath := path.Join(
 165                                                 govpn.PeersPath,
 166                                                 state.peer.Id.String(),
 167                                                 "down.sh",
 168                                         )
 169                                         go govpn.ScriptCall(downPath, state.tap.Name)
 170                                         state.terminate <- struct{}{}
 171                                         state.peer.Zero()
 172                                 }
 173                         }
 174                 case peerReady = <-peerReadySink:
 175                         for addr, state := range peers {
 176                                 if state.tap.Name != peerReady.iface {
 177                                         continue
 178                                 }
 179                                 delete(peers, addr)
 180                                 delete(knownPeers, addr)
 181                                 state.terminate <- struct{}{}
 182                                 state.peer.Zero()
 183                                 break
 184                         }
 185                         state := NewPeerState(peerReady.peer, peerReady.iface)
 186                         if state == nil {
 187                                 continue
 188                         }
 189                         peers[peerReady.peer.Addr] = state
 190                         knownPeers[peerReady.peer.Addr] = &peerReady.peer
 191                         states[peerReady.peer.Addr].Zero()
 192                         delete(states, peerReady.peer.Addr)
 193                         log.Println("Registered interface", peerReady.iface, "with peer", peer)
 194                         go func(state *PeerState) {
 195                                 for data := range state.sink {
 196                                         ethSink <- EthEvent{
 197                                                 peer:  state.peer,
 198                                                 data:  data,
 199                                                 ready: state.ready,
 200                                         }
 201                                 }
 202                         }(state)
 203                 case ethEvent = <-ethSink:
 204                         if s, exists := peers[ethEvent.peer.Addr]; !exists || s.peer != ethEvent.peer {
 205                                 continue
 206                         }
 207                         ethEvent.peer.EthProcess(ethEvent.data, ethEvent.ready)
 208                 case pkt = <-sink:
 209                         if pkt.data == nil {
 210                                 pkt.ready <- struct{}{}
 211                                 continue
 212                         }
 213                         handshakeProcessForce = false
 214                 HandshakeProcess:
 215                         if _, exists = peers[pkt.addr]; handshakeProcessForce || !exists {
 216                                 peerId = govpn.IDsCache.Find(pkt.data)
 217                                 if peerId == nil {
 218                                         log.Println("Unknown identity from", pkt.addr)
 219                                         pkt.ready <- struct{}{}
 220                                         continue
 221                                 }
 222                                 peerConf = peerId.Conf()
 223                                 if peerConf == nil {
 224                                         log.Println("Can not get peer configuration", peerId.String())
 225                                         pkt.ready <- struct{}{}
 226                                         continue
 227                                 }
 228                                 state, exists = states[pkt.addr]
 229                                 if !exists {
 230                                         state = govpn.HandshakeNew(pkt.addr, pkt.conn, peerConf)
 231                                         states[pkt.addr] = state
 232                                 }
 233                                 peer = state.Server(pkt.data)
 234                                 if peer != nil {
 235                                         log.Println("Peer handshake finished", peer)
 236                                         if _, exists = peers[pkt.addr]; exists {
 237                                                 go func() {
 238                                                         peerReadySink <- PeerReadyEvent{
 239                                                                 peer, peers[pkt.addr].tap.Name,
 240                                                         }
 241                                                 }()
 242                                         } else {
 243                                                 go func() {
 244                                                         upPath := path.Join(govpn.PeersPath, peer.Id.String(), "up.sh")
 245                                                         result, err := govpn.ScriptCall(upPath, "")
 246                                                         if err != nil {
 247                                                                 return
 248                                                         }
 249                                                         sepIndex := bytes.Index(result, []byte{'\n'})
 250                                                         if sepIndex < 0 {
 251                                                                 sepIndex = len(result)
 252                                                         }
 253                                                         ifaceName := string(result[:sepIndex])
 254                                                         peerReadySink <- PeerReadyEvent{peer, ifaceName}
 255                                                 }()
 256                                         }
 257                                 }
 258                                 if !handshakeProcessForce {
 259                                         pkt.ready <- struct{}{}
 260                                 }
 261                                 continue
 262                         }
 263                         peerState, exists = peers[pkt.addr]
 264                         if !exists {
 265                                 pkt.ready <- struct{}{}
 266                                 continue
 267                         }
 268                         // If it fails during processing, then try to work with it
 269                         // as with handshake packet
 270                         if !peerState.peer.PktProcess(pkt.data, peerState.tap, pkt.ready) {
 271                                 handshakeProcessForce = true
 272                                 goto HandshakeProcess
 273                         }
 274                 }
 275         }
 276 }