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/>.
32 bind, err := net.ResolveTCPAddr("tcp", *bindAddr)
34 log.Fatalln("Can not resolve bind address:", err)
36 listener, err := net.ListenTCP("tcp", bind)
38 log.Fatalln("Can not listen on TCP:", err)
40 log.Println("Listening on TCP:" + *bindAddr)
43 conn, err := listener.AcceptTCP()
45 log.Println("Error accepting TCP:", err)
53 func handleTCP(conn net.Conn) {
54 addr := conn.RemoteAddr().String()
55 buf := make([]byte, govpn.MTU)
59 var hs *govpn.Handshake
63 var conf *govpn.PeerConf
65 if prev == govpn.MTU {
68 conn.SetReadDeadline(time.Now().Add(time.Duration(govpn.TimeoutDefault) * time.Second))
69 n, err = conn.Read(buf[prev:])
71 // Either EOFed or timeouted
75 peerId := govpn.IDsCache.Find(buf[:prev])
82 log.Println("Can not get peer configuration:", peerId.String())
85 hs = govpn.NewHandshake(addr, conn, conf)
87 peer = hs.Server(buf[:prev])
93 log.Println("Peer handshake finished:", addr, peer.Id.String())
95 addrPrev, exists := peersById[*peer.Id]
96 peersByIdLock.RUnlock()
99 peers[addrPrev].terminator <- struct{}{}
100 tap = peers[addrPrev].tap
104 terminator: make(chan struct{}),
109 delete(peers, addrPrev)
110 delete(knownPeers, addrPrev)
112 knownPeers[addr] = &peer
113 peersById[*peer.Id] = addr
115 peersByIdLock.Unlock()
117 log.Println("Rehandshake processed:", peer.Id.String())
119 ifaceName, err := callUp(peer.Id)
123 tap, err = govpn.TAPListen(ifaceName)
125 log.Println("Unable to create TAP:", err)
131 terminator: make(chan struct{}, 1),
138 peersById[*peer.Id] = addr
139 knownPeers[addr] = &peer
141 peersByIdLock.Unlock()
143 log.Println("Peer created:", peer.Id.String())
154 nonceExpectation := make([]byte, govpn.NonceSize)
155 binary.BigEndian.PutUint64(nonceExpectation, peer.NonceExpect)
156 peer.NonceCipher.Encrypt(nonceExpectation, nonceExpectation)
160 if prev == govpn.MTU {
163 conn.SetReadDeadline(time.Now().Add(conf.Timeout))
164 n, err = conn.Read(buf[prev:])
166 // Either EOFed or timeouted
171 if prev < govpn.MinPktLength {
174 i = bytes.Index(buf[:prev], nonceExpectation)
178 if !peer.PktProcess(buf[:i+govpn.NonceSize], tap, false) {
180 "Unauthenticated packet, dropping connection",
181 addr, peer.Id.String(),
185 binary.BigEndian.PutUint64(nonceExpectation, peer.NonceExpect)
186 peer.NonceCipher.Encrypt(nonceExpectation, nonceExpectation)
187 copy(buf, buf[i+govpn.NonceSize:prev])
188 prev = prev - i - govpn.NonceSize