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, tcp or all")
  39         peersPath = flag.String("peers", "peers", "Path to peers keys directory")
  40         stats     = flag.String("stats", "", "Enable stats retrieving on host:port")
  41         proxy     = flag.String("proxy", "", "Enable HTTP proxy on host:port")
  42         mtu       = flag.Int("mtu", 1452, "MTU for outgoing packets")
  43         egdPath   = flag.String("egd", "", "Optional path to EGD socket")
  44 )
  45
  46 type Pkt struct {
  47         addr  string
  48         conn  io.Writer
  49         data  []byte
  50         ready chan struct{}
  51 }
  52
  53 type PeerReadyEvent struct {
  54         peer  *govpn.Peer
  55         iface string
  56 }
  57
  58 type PeerState struct {
  59         peer      *govpn.Peer
  60         tap       *govpn.TAP
  61         sink      chan []byte
  62         ready     chan struct{}
  63         terminate chan struct{}
  64 }
  65
  66 func NewPeerState(peer *govpn.Peer, iface string) *PeerState {
  67         tap, sink, ready, terminate, err := govpn.TAPListen(iface, peer.Timeout, peer.CPR)
  68         if err != nil {
  69                 log.Println("Unable to create Eth", err)
  70                 return nil
  71         }
  72         state := PeerState{
  73                 peer:      peer,
  74                 tap:       tap,
  75                 sink:      sink,
  76                 ready:     ready,
  77                 terminate: terminate,
  78         }
  79         return &state
  80 }
  81
  82 type EthEvent struct {
  83         peer  *govpn.Peer
  84         data  []byte
  85         ready chan struct{}
  86 }
  87
  88 func main() {
  89         flag.Parse()
  90         timeout := time.Second * time.Duration(govpn.TimeoutDefault)
  91         log.SetFlags(log.Ldate | log.Lmicroseconds | log.Lshortfile)
  92         log.Println(govpn.VersionGet())
  93
  94         govpn.MTU = *mtu
  95         govpn.PeersInit(*peersPath)
  96
  97         if *egdPath != "" {
  98                 log.Println("Using", *egdPath, "EGD")
  99                 govpn.EGDInit(*egdPath)
 100         }
 101
 102         sink := make(chan Pkt)
 103         switch *proto {
 104         case "udp":
 105                 startUDP(sink)
 106         case "tcp":
 107                 startTCP(sink)
 108         case "all":
 109                 startUDP(sink)
 110                 startTCP(sink)
 111         default:
 112                 log.Fatalln("Unknown protocol specified")
 113         }
 114
 115         termSignal := make(chan os.Signal, 1)
 116         signal.Notify(termSignal, os.Interrupt, os.Kill)
 117
 118         hsHeartbeat := time.Tick(timeout)
 119         go func() { <-hsHeartbeat }()
 120
 121         var state *govpn.Handshake
 122         var peerState *PeerState
 123         var peer *govpn.Peer
 124         var exists bool
 125         states := make(map[string]*govpn.Handshake)
 126         peers := make(map[string]*PeerState)
 127         peerReadySink := make(chan PeerReadyEvent)
 128         knownPeers := govpn.KnownPeers(make(map[string]**govpn.Peer))
 129         var peerReady PeerReadyEvent
 130         var pkt Pkt
 131         var ethEvent EthEvent
 132         var peerId *govpn.PeerId
 133         var peerConf *govpn.PeerConf
 134         var handshakeProcessForce bool
 135         ethSink := make(chan EthEvent)
 136
 137         log.Println("Max MTU on TAP interface:", govpn.TAPMaxMTU())
 138         if *stats != "" {
 139                 log.Println("Stats are going to listen on", *stats)
 140                 statsPort, err := net.Listen("tcp", *stats)
 141                 if err != nil {
 142                         log.Fatalln("Can not listen on stats port:", err)
 143                 }
 144                 go govpn.StatsProcessor(statsPort, &knownPeers)
 145         }
 146         if *proxy != "" {
 147                 go proxyStart(sink)
 148         }
 149         log.Println("Server started")
 150
 151 MainCycle:
 152         for {
 153                 select {
 154                 case <-termSignal:
 155                         break MainCycle
 156                 case <-hsHeartbeat:
 157                         now := time.Now()
 158                         for addr, hs := range states {
 159                                 if hs.LastPing.Add(timeout).Before(now) {
 160                                         log.Println("Deleting handshake state", addr)
 161                                         hs.Zero()
 162                                         delete(states, addr)
 163                                 }
 164                         }
 165                         for addr, state := range peers {
 166                                 if state.peer.LastPing.Add(timeout).Before(now) {
 167                                         log.Println("Deleting peer", state.peer)
 168                                         delete(peers, addr)
 169                                         delete(knownPeers, addr)
 170                                         downPath := path.Join(
 171                                                 govpn.PeersPath,
 172                                                 state.peer.Id.String(),
 173                                                 "down.sh",
 174                                         )
 175                                         go govpn.ScriptCall(downPath, state.tap.Name)
 176                                         state.terminate <- struct{}{}
 177                                         state.peer.Zero()
 178                                 }
 179                         }
 180                 case peerReady = <-peerReadySink:
 181                         for addr, state := range peers {
 182                                 if state.tap.Name != peerReady.iface {
 183                                         continue
 184                                 }
 185                                 delete(peers, addr)
 186                                 delete(knownPeers, addr)
 187                                 state.terminate <- struct{}{}
 188                                 state.peer.Zero()
 189                                 break
 190                         }
 191                         state := NewPeerState(peerReady.peer, peerReady.iface)
 192                         if state == nil {
 193                                 continue
 194                         }
 195                         peers[peerReady.peer.Addr] = state
 196                         knownPeers[peerReady.peer.Addr] = &peerReady.peer
 197                         states[peerReady.peer.Addr].Zero()
 198                         delete(states, peerReady.peer.Addr)
 199                         log.Println("Registered interface", peerReady.iface, "with peer", peer)
 200                         go func(state *PeerState) {
 201                                 for data := range state.sink {
 202                                         ethSink <- EthEvent{
 203                                                 peer:  state.peer,
 204                                                 data:  data,
 205                                                 ready: state.ready,
 206                                         }
 207                                 }
 208                         }(state)
 209                 case ethEvent = <-ethSink:
 210                         if s, exists := peers[ethEvent.peer.Addr]; !exists || s.peer != ethEvent.peer {
 211                                 continue
 212                         }
 213                         ethEvent.peer.EthProcess(ethEvent.data, ethEvent.ready)
 214                 case pkt = <-sink:
 215                         if pkt.data == nil {
 216                                 pkt.ready <- struct{}{}
 217                                 continue
 218                         }
 219                         handshakeProcessForce = false
 220                 HandshakeProcess:
 221                         if _, exists = peers[pkt.addr]; handshakeProcessForce || !exists {
 222                                 peerId = govpn.IDsCache.Find(pkt.data)
 223                                 if peerId == nil {
 224                                         log.Println("Unknown identity from", pkt.addr)
 225                                         pkt.ready <- struct{}{}
 226                                         continue
 227                                 }
 228                                 peerConf = peerId.Conf()
 229                                 if peerConf == nil {
 230                                         log.Println("Can not get peer configuration", peerId.String())
 231                                         pkt.ready <- struct{}{}
 232                                         continue
 233                                 }
 234                                 state, exists = states[pkt.addr]
 235                                 if !exists {
 236                                         state = govpn.HandshakeNew(pkt.addr, pkt.conn, peerConf)
 237                                         states[pkt.addr] = state
 238                                 }
 239                                 peer = state.Server(pkt.data)
 240                                 if peer != nil {
 241                                         log.Println("Peer handshake finished", peer)
 242                                         if _, exists = peers[pkt.addr]; exists {
 243                                                 go func() {
 244                                                         peerReadySink <- PeerReadyEvent{
 245                                                                 peer, peers[pkt.addr].tap.Name,
 246                                                         }
 247                                                 }()
 248                                         } else {
 249                                                 go func() {
 250                                                         upPath := path.Join(govpn.PeersPath, peer.Id.String(), "up.sh")
 251                                                         result, err := govpn.ScriptCall(upPath, "")
 252                                                         if err != nil {
 253                                                                 return
 254                                                         }
 255                                                         sepIndex := bytes.Index(result, []byte{'\n'})
 256                                                         if sepIndex < 0 {
 257                                                                 sepIndex = len(result)
 258                                                         }
 259                                                         ifaceName := string(result[:sepIndex])
 260                                                         peerReadySink <- PeerReadyEvent{peer, ifaceName}
 261                                                 }()
 262                                         }
 263                                 }
 264                                 if !handshakeProcessForce {
 265                                         pkt.ready <- struct{}{}
 266                                 }
 267                                 continue
 268                         }
 269                         peerState, exists = peers[pkt.addr]
 270                         if !exists {
 271                                 pkt.ready <- struct{}{}
 272                                 continue
 273                         }
 274                         // If it fails during processing, then try to work with it
 275                         // as with handshake packet
 276                         if !peerState.peer.PktProcess(pkt.data, peerState.tap, pkt.ready) {
 277                                 handshakeProcessForce = true
 278                                 goto HandshakeProcess
 279                         }
 280                 }
 281         }
 282 }