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