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