2 GoVPN -- simple secure free software virtual private network daemon
3 Copyright (C) 2014-2015 Sergey Matveev <stargrave@stargrave.org>
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.
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.
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/>.
28 type UDPSender struct {
33 func (c UDPSender) Write(data []byte) (int, error) {
34 return c.conn.WriteToUDP(data, c.addr)
38 // Buffers for UDP parallel processing
39 udpBufs chan []byte = make(chan []byte, 1<<8)
43 bind, err := net.ResolveUDPAddr("udp", *bindAddr)
45 log.Fatalln("Can not resolve bind address:", err)
47 conn, err := net.ListenUDP("udp", bind)
49 log.Fatalln("Can not listen on UDP:", err)
51 log.Println("Listening on UDP:" + *bindAddr)
53 udpBufs <- make([]byte, govpn.MTU)
56 var raddr *net.UDPAddr
61 var hs *govpn.Handshake
64 var peerId *govpn.PeerId
66 var conf *govpn.PeerConf
69 n, raddr, err = conn.ReadFromUDP(buf)
71 log.Println("Unexpected error when receiving", err)
77 ps, exists = peers[addr]
82 go func(ps *govpn.Peer, tap *govpn.TAP, buf []byte, n int) {
83 peer.PktProcess(buf[:n], tap, true)
85 }(ps.peer, ps.tap, buf, n)
89 hs, exists = handshakes[addr]
94 peer = hs.Server(buf[:n])
99 log.Println("Peer handshake finished:", addr, peer.Id.String())
102 delete(handshakes, addr)
106 udpBufs <- make([]byte, govpn.MTU)
107 udpBufs <- make([]byte, govpn.MTU)
109 peersByIdLock.RLock()
110 addrPrev, exists = peersById[*peer.Id]
111 peersByIdLock.RUnlock()
114 peers[addrPrev].terminator <- struct{}{}
117 tap: peers[addrPrev].tap,
118 terminator: make(chan struct{}),
120 go func(ps PeerState) {
127 delete(peers, addrPrev)
128 delete(knownPeers, addrPrev)
130 knownPeers[addr] = &peer
131 peersById[*peer.Id] = addr
133 peersByIdLock.Unlock()
135 log.Println("Rehandshake processed:", peer.Id.String())
137 go func(addr string, peer *govpn.Peer) {
138 ifaceName, err := callUp(peer.Id)
142 tap, err := govpn.TAPListen(ifaceName)
144 log.Println("Unable to create TAP:", err)
150 terminator: make(chan struct{}),
152 go func(ps PeerState) {
161 knownPeers[addr] = &peer
162 peersById[*peer.Id] = addr
164 peersByIdLock.Unlock()
166 log.Println("Peer created:", peer.Id.String())
171 peerId = govpn.IDsCache.Find(buf[:n])
173 log.Println("Unknown identity from:", addr)
178 log.Println("Unable to get peer configuration:", peerId.String())
181 hs = govpn.NewHandshake(
183 UDPSender{conn: conn, addr: raddr},
188 handshakes[addr] = hs