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         ethSink := make(chan EthEvent)
 118
 119         log.Println("Server version", govpn.Version)
 120         log.Println("Server started")
 121
 122 MainCycle:
 123         for {
 124                 select {
 125                 case <-termSignal:
 126                         break MainCycle
 127                 case <-hsHeartbeat:
 128                         now := time.Now()
 129                         for addr, hs := range states {
 130                                 if hs.LastPing.Add(timeout).Before(now) {
 131                                         log.Println("Deleting handshake state", addr)
 132                                         delete(states, addr)
 133                                 }
 134                         }
 135                         for addr, state := range peers {
 136                                 if state.peer.LastPing.Add(timeout).Before(now) {
 137                                         log.Println("Deleting peer", state.peer)
 138                                         delete(peers, addr)
 139                                         downPath := path.Join(
 140                                                 govpn.PeersPath,
 141                                                 state.peer.Id.String(),
 142                                                 "down.sh",
 143                                         )
 144                                         go govpn.ScriptCall(downPath, state.tap.Name)
 145                                         state.terminate <- struct{}{}
 146                                 }
 147                         }
 148                 case peerReady = <-peerReadySink:
 149                         for addr, state := range peers {
 150                                 if state.tap.Name != peerReady.iface {
 151                                         continue
 152                                 }
 153                                 delete(peers, addr)
 154                                 state.terminate <- struct{}{}
 155                                 break
 156                         }
 157                         addr = peerReady.peer.Addr.String()
 158                         state := NewPeerState(peerReady.peer, peerReady.iface)
 159                         if state == nil {
 160                                 continue
 161                         }
 162                         peers[addr] = state
 163                         delete(states, addr)
 164                         log.Println("Registered interface", peerReady.iface, "with peer", peer)
 165                         go func(state *PeerState) {
 166                                 for data := range state.sink {
 167                                         ethSink <- EthEvent{
 168                                                 peer:  state.peer,
 169                                                 data:  data,
 170                                                 ready: state.ready,
 171                                         }
 172                                 }
 173                         }(state)
 174                 case ethEvent = <-ethSink:
 175                         if _, exists := peers[ethEvent.peer.Addr.String()]; !exists {
 176                                 continue
 177                         }
 178                         ethEvent.peer.EthProcess(ethEvent.data, conn, ethEvent.ready)
 179                 case udpPkt = <-udpSink:
 180                         if udpPkt == nil {
 181                                 udpReady <- struct{}{}
 182                                 continue
 183                         }
 184                         udpPktData = udpBuf[:udpPkt.Size]
 185                         addr = udpPkt.Addr.String()
 186                         if govpn.IsValidHandshakePkt(udpPktData) {
 187                                 state, exists = states[addr]
 188                                 if !exists {
 189                                         state = govpn.HandshakeNew(udpPkt.Addr)
 190                                         states[addr] = state
 191                                 }
 192                                 peer = state.Server(conn, udpPktData)
 193                                 if peer != nil {
 194                                         log.Println("Peer handshake finished", peer)
 195                                         if _, exists = peers[addr]; exists {
 196                                                 go func() {
 197                                                         peerReadySink <- PeerReadyEvent{peer, peers[addr].tap.Name}
 198                                                 }()
 199                                         } else {
 200                                                 go func() {
 201                                                         upPath := path.Join(govpn.PeersPath, peer.Id.String(), "up.sh")
 202                                                         result, err := govpn.ScriptCall(upPath, "")
 203                                                         if err != nil {
 204                                                                 return
 205                                                         }
 206                                                         sepIndex := bytes.Index(result, []byte{'\n'})
 207                                                         if sepIndex < 0 {
 208                                                                 sepIndex = len(result)
 209                                                         }
 210                                                         ifaceName := string(result[:sepIndex])
 211                                                         peerReadySink <- PeerReadyEvent{peer, ifaceName}
 212                                                 }()
 213                                         }
 214                                 }
 215                                 udpReady <- struct{}{}
 216                                 continue
 217                         }
 218                         peerState, exists = peers[addr]
 219                         if !exists {
 220                                 udpReady <- struct{}{}
 221                                 continue
 222                         }
 223                         peerState.peer.UDPProcess(udpPktData, peerState.tap, udpReady)
 224                 }
 225         }
 226 }