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/>.
31 bind, err := net.ResolveTCPAddr("tcp", *bindAddr)
33 log.Fatalln("Can not resolve bind address:", err)
35 listener, err := net.ListenTCP("tcp", bind)
37 log.Fatalln("Can not listen on TCP:", err)
39 log.Println("Listening on TCP:" + *bindAddr)
42 conn, err := listener.AcceptTCP()
44 log.Println("Error accepting TCP:", err)
52 func handleTCP(conn net.Conn) {
53 addr := conn.RemoteAddr().String()
54 buf := make([]byte, govpn.MTU)
58 var hs *govpn.Handshake
62 var conf *govpn.PeerConf
64 if prev == govpn.MTU {
67 conn.SetReadDeadline(time.Now().Add(time.Duration(govpn.TimeoutDefault) * time.Second))
68 n, err = conn.Read(buf[prev:])
70 // Either EOFed or timeouted
74 peerId := idsCache.Find(buf[:prev])
81 log.Println("Can not get peer configuration:", peerId.String())
84 hs = govpn.NewHandshake(addr, conn, conf)
86 peer = hs.Server(buf[:prev])
92 log.Println("Peer handshake finished:", addr, peer.Id.String())
94 addrPrev, exists := peersById[*peer.Id]
95 peersByIdLock.RUnlock()
98 peers[addrPrev].terminator <- struct{}{}
99 tap = peers[addrPrev].tap
103 terminator: make(chan struct{}),
108 delete(peers, addrPrev)
109 delete(knownPeers, addrPrev)
111 knownPeers[addr] = &peer
112 peersById[*peer.Id] = addr
114 peersByIdLock.Unlock()
116 log.Println("Rehandshake processed:", peer.Id.String())
118 ifaceName, err := callUp(peer.Id)
122 tap, err = govpn.TAPListen(ifaceName)
124 log.Println("Unable to create TAP:", err)
130 terminator: make(chan struct{}, 1),
137 peersById[*peer.Id] = addr
138 knownPeers[addr] = &peer
140 peersByIdLock.Unlock()
142 log.Println("Peer created:", peer.Id.String())
153 nonceExpectation := make([]byte, govpn.NonceSize)
154 peer.NonceExpectation(nonceExpectation)
158 if prev == govpn.MTU {
161 conn.SetReadDeadline(time.Now().Add(conf.Timeout))
162 n, err = conn.Read(buf[prev:])
164 // Either EOFed or timeouted
169 if prev < govpn.MinPktLength {
172 i = bytes.Index(buf[:prev], nonceExpectation)
176 if !peer.PktProcess(buf[:i+govpn.NonceSize], tap, false) {
178 "Unauthenticated packet, dropping connection",
179 addr, peer.Id.String(),
183 peer.NonceExpectation(nonceExpectation)
184 copy(buf, buf[i+govpn.NonceSize:prev])
185 prev = prev - i - govpn.NonceSize