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         mtu       = flag.Int("mtu", 1500, "MTU")
  39         nonceDiff = flag.Int("noncediff", 1, "Allow nonce difference")
  40         timeoutP  = flag.Int("timeout", 60, "Timeout seconds")
  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)
  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(*timeoutP)
  81         var err error
  82         log.SetFlags(log.Ldate | log.Lmicroseconds | log.Lshortfile)
  83
  84         govpn.MTU = *mtu
  85         govpn.Timeout = *timeoutP
  86         govpn.Noncediff = *nonceDiff
  87         govpn.PeersInit(*peersPath)
  88
  89         bind, err := net.ResolveUDPAddr("udp", *bindAddr)
  90         if err != nil {
  91                 panic(err)
  92         }
  93         conn, err := net.ListenUDP("udp", bind)
  94         if err != nil {
  95                 panic(err)
  96         }
  97         udpSink, udpBuf, udpReady := govpn.ConnListen(conn)
  98
  99         termSignal := make(chan os.Signal, 1)
 100         signal.Notify(termSignal, os.Interrupt, os.Kill)
 101
 102         hsHeartbeat := time.Tick(timeout)
 103         go func() { <-hsHeartbeat }()
 104
 105         var addr string
 106         var state *govpn.Handshake
 107         var peerState *PeerState
 108         var peer *govpn.Peer
 109         var exists bool
 110         states := make(map[string]*govpn.Handshake)
 111         peers := make(map[string]*PeerState)
 112         peerReadySink := make(chan PeerReadyEvent)
 113         var peerReady PeerReadyEvent
 114         var udpPkt *govpn.UDPPkt
 115         var udpPktData []byte
 116         var ethEvent EthEvent
 117         var peerId *govpn.PeerId
 118         var handshakeProcessForce bool
 119         ethSink := make(chan EthEvent)
 120
 121         log.Println(govpn.VersionGet())
 122         log.Println("Server started")
 123
 124 MainCycle:
 125         for {
 126                 select {
 127                 case <-termSignal:
 128                         break MainCycle
 129                 case <-hsHeartbeat:
 130                         now := time.Now()
 131                         for addr, hs := range states {
 132                                 if hs.LastPing.Add(timeout).Before(now) {
 133                                         log.Println("Deleting handshake state", addr)
 134                                         hs.Zero()
 135                                         delete(states, addr)
 136                                 }
 137                         }
 138                         for addr, state := range peers {
 139                                 if state.peer.LastPing.Add(timeout).Before(now) {
 140                                         log.Println("Deleting peer", state.peer)
 141                                         delete(peers, addr)
 142                                         downPath := path.Join(
 143                                                 govpn.PeersPath,
 144                                                 state.peer.Id.String(),
 145                                                 "down.sh",
 146                                         )
 147                                         go govpn.ScriptCall(downPath, state.tap.Name)
 148                                         state.terminate <- struct{}{}
 149                                         state.peer.Zero()
 150                                 }
 151                         }
 152                 case peerReady = <-peerReadySink:
 153                         for addr, state := range peers {
 154                                 if state.tap.Name != peerReady.iface {
 155                                         continue
 156                                 }
 157                                 delete(peers, addr)
 158                                 state.terminate <- struct{}{}
 159                                 state.peer.Zero()
 160                                 break
 161                         }
 162                         addr = peerReady.peer.Addr.String()
 163                         state := NewPeerState(peerReady.peer, peerReady.iface)
 164                         if state == nil {
 165                                 continue
 166                         }
 167                         peers[addr] = state
 168                         states[addr].Zero()
 169                         delete(states, addr)
 170                         log.Println("Registered interface", peerReady.iface, "with peer", peer)
 171                         go func(state *PeerState) {
 172                                 for data := range state.sink {
 173                                         ethSink <- EthEvent{
 174                                                 peer:  state.peer,
 175                                                 data:  data,
 176                                                 ready: state.ready,
 177                                         }
 178                                 }
 179                         }(state)
 180                 case ethEvent = <-ethSink:
 181                         if s, exists := peers[ethEvent.peer.Addr.String()]; !exists || s.peer != ethEvent.peer {
 182                                 continue
 183                         }
 184                         ethEvent.peer.EthProcess(ethEvent.data, conn, ethEvent.ready)
 185                 case udpPkt = <-udpSink:
 186                         if udpPkt == nil {
 187                                 udpReady <- struct{}{}
 188                                 continue
 189                         }
 190                         udpPktData = udpBuf[:udpPkt.Size]
 191                         addr = udpPkt.Addr.String()
 192                         handshakeProcessForce = false
 193                 HandshakeProcess:
 194                         if _, exists = peers[addr]; handshakeProcessForce || !exists {
 195                                 peerId = govpn.IDsCache.Find(udpPktData)
 196                                 if peerId == nil {
 197                                         log.Println("Unknown identity from", addr)
 198                                         udpReady <- struct{}{}
 199                                         continue
 200                                 }
 201                                 state, exists = states[addr]
 202                                 if !exists {
 203                                         state = govpn.HandshakeNew(udpPkt.Addr)
 204                                         states[addr] = state
 205                                 }
 206                                 peer = state.Server(peerId, conn, udpPktData)
 207                                 if peer != nil {
 208                                         log.Println("Peer handshake finished", peer)
 209                                         if _, exists = peers[addr]; exists {
 210                                                 go func() {
 211                                                         peerReadySink <- PeerReadyEvent{peer, peers[addr].tap.Name}
 212                                                 }()
 213                                         } else {
 214                                                 go func() {
 215                                                         upPath := path.Join(govpn.PeersPath, peer.Id.String(), "up.sh")
 216                                                         result, err := govpn.ScriptCall(upPath, "")
 217                                                         if err != nil {
 218                                                                 return
 219                                                         }
 220                                                         sepIndex := bytes.Index(result, []byte{'\n'})
 221                                                         if sepIndex < 0 {
 222                                                                 sepIndex = len(result)
 223                                                         }
 224                                                         ifaceName := string(result[:sepIndex])
 225                                                         peerReadySink <- PeerReadyEvent{peer, ifaceName}
 226                                                 }()
 227                                         }
 228                                 }
 229                                 if !handshakeProcessForce {
 230                                         udpReady <- struct{}{}
 231                                 }
 232                                 continue
 233                         }
 234                         peerState, exists = peers[addr]
 235                         if !exists {
 236                                 udpReady <- struct{}{}
 237                                 continue
 238                         }
 239                         // If it fails during processing, then try to work with it
 240                         // as with handshake packet
 241                         if !peerState.peer.UDPProcess(udpPktData, peerState.tap, udpReady) {
 242                                 handshakeProcessForce = true
 243                                 goto HandshakeProcess
 244                         }
 245                 }
 246         }
 247 }