func handleTCP(conn *net.TCPConn, timeouted, rehandshaking, termination chan struct{}) {
hs := govpn.HandshakeStart(*remoteAddr, conn, conf)
buf := make([]byte, govpn.MTU)
var n int
var err error
var prev int
var peer *govpn.Peer
var terminator chan struct{}
HandshakeCycle:
for {
select {
case <-termination:
break HandshakeCycle
default:
}
if prev == govpn.MTU {
log.Println("Timeouted waiting for the packet")
timeouted <- struct{}{}
break HandshakeCycle
}
conn.SetReadDeadline(time.Now().Add(time.Duration(timeout) * time.Second))
n, err = conn.Read(buf[prev:])
if err != nil {
log.Println("Connection timeouted")
timeouted <- struct{}{}
break HandshakeCycle
}
prev += n
peerId := idsCache.Find(buf[:prev])
if peerId == nil {
continue
}
peer = hs.Client(buf[:prev])
prev = 0
if peer == nil {
continue
}
log.Println("Handshake completed")
knownPeers = govpn.KnownPeers(map[string]**govpn.Peer{*remoteAddr: &peer})
if firstUpCall {
go govpn.ScriptCall(*upPath, *ifaceName)
firstUpCall = false
}
hs.Zero()
terminator = make(chan struct{})
go func() {
heartbeat := time.NewTicker(peer.Timeout)
var data []byte
Processor:
for {
select {
case <-heartbeat.C:
peer.EthProcess(nil)
case <-terminator:
break Processor
case data = <-tap.Sink:
peer.EthProcess(data)
}
}
heartbeat.Stop()
peer.Zero()
}()
break HandshakeCycle
}
if hs != nil {
hs.Zero()
}
if peer == nil {
return
}
nonceExpectation := make([]byte, govpn.NonceSize)
peer.NonceExpectation(nonceExpectation)
prev = 0
var i int
TransportCycle:
for {
select {
case <-termination:
break TransportCycle
default:
}
if prev == govpn.MTU {
log.Println("Timeouted waiting for the packet")
timeouted <- struct{}{}
break TransportCycle
}
conn.SetReadDeadline(time.Now().Add(time.Duration(timeout) * time.Second))
n, err = conn.Read(buf[prev:])
if err != nil {
log.Println("Connection timeouted")
timeouted <- struct{}{}
break TransportCycle
}
prev += n
CheckMore:
if prev < govpn.MinPktLength {
continue
}
i = bytes.Index(buf[:prev], nonceExpectation)
if i == -1 {
continue
}
if !peer.PktProcess(buf[:i+govpn.NonceSize], tap, false) {
log.Println("Unauthenticated packet, dropping connection")
timeouted <- struct{}{}
break TransportCycle
}
if atomic.LoadInt64(&peer.BytesIn)+atomic.LoadInt64(&peer.BytesOut) > govpn.MaxBytesPerKey {
log.Println("Need rehandshake")
rehandshaking <- struct{}{}
break TransportCycle
}
peer.NonceExpectation(nonceExpectation)
copy(buf, buf[i+govpn.NonceSize:prev])
prev = prev - i - govpn.NonceSize
goto CheckMore
}
if terminator != nil {
terminator <- struct{}{}
}
peer.Zero()
conn.Close()
}
func ServerStart(bindAddr, proto, confPath, stats, proxy, egdPath string, mtu int) {
timeout := time.Second * time.Duration(govpn.TimeoutDefault)
log.SetFlags(log.Ldate | log.Lmicroseconds | log.Lshortfile)
log.Println(govpn.VersionGet())
if len(bindAddr) <= 0 {
bindAddr = "[::]:1194"
}
if len(proto) <= 0 {
proto = "udp"
}
if len(confPath) <= 0 {
confPath = "peers.json"
}
if mtu <= 0 {
mtu = 1452
}
govpn.MTU = mtu
confInit(&confPath)
knownPeers = govpn.KnownPeers(make(map[string]**govpn.Peer))
if egdPath != "" {
log.Println("Using", egdPath, "EGD")
govpn.EGDInit(egdPath)
}
switch proto {
case "udp":
startUDP(&bindAddr)
case "tcp":
startTCP(&bindAddr)
case "all":
startUDP(&bindAddr)
startTCP(&bindAddr)
default:
log.Fatalln("Unknown protocol specified")
}
termSignal := make(chan os.Signal, 1)
signal.Notify(termSignal, os.Interrupt, os.Kill)
hsHeartbeat := time.Tick(timeout)
go func() { <-hsHeartbeat }()
log.Println("Max MTU on TAP interface:", govpn.TAPMaxMTU())
if stats != "" {
log.Println("Stats are going to listen on", stats)
statsPort, err := net.Listen("tcp", stats)
if err != nil {
log.Fatalln("Can not listen on stats port:", err)
}
go govpn.StatsProcessor(statsPort, &knownPeers)
}
if proxy != "" {
go proxyStart(&proxy)
}
log.Println("Server started")
var needsDeletion bool
MainCycle:
for {
select {
case <-termSignal:
break MainCycle
case <-hsHeartbeat:
now := time.Now()
hsLock.Lock()
for addr, hs := range handshakes {
if hs.LastPing.Add(timeout).Before(now) {
log.Println("Deleting handshake state", addr)
hs.Zero()
delete(handshakes, addr)
}
}
peersLock.Lock()
peersByIdLock.Lock()
kpLock.Lock()
for addr, ps := range peers {
ps.peer.BusyR.Lock()
needsDeletion = ps.peer.LastPing.Add(timeout).Before(now)
ps.peer.BusyR.Unlock()
if needsDeletion {
log.Println("Deleting peer", ps.peer)
delete(peers, addr)
delete(knownPeers, addr)
delete(peersById, *ps.peer.Id)
go govpn.ScriptCall(
confs[*ps.peer.Id].Down,
ps.tap.Name,
)
ps.terminator <- struct{}{}
}
}
hsLock.Unlock()
peersLock.Unlock()
peersByIdLock.Unlock()
kpLock.Unlock()
}
}
}
func startUDP(timeouted, rehandshaking, termination chan struct{}) {
remote, err := net.ResolveUDPAddr("udp", *remoteAddr)
if err != nil {
log.Fatalln("Can not resolve remote address:", err)
}
conn, err := net.DialUDP("udp", nil, remote)
if err != nil {
log.Fatalln("Can not listen on UDP:", err)
}
log.Println("Connected to UDP:" + *remoteAddr)
hs := govpn.HandshakeStart(*remoteAddr, conn, conf)
buf := make([]byte, govpn.MTU)
var n int
var timeouts int
var peer *govpn.Peer
var terminator chan struct{}
MainCycle:
for {
select {
case <-termination:
break MainCycle
default:
}
conn.SetReadDeadline(time.Now().Add(time.Second))
n, err = conn.Read(buf)
if timeouts == timeout {
log.Println("Timeouted")
timeouted <- struct{}{}
break
}
if err != nil {
timeouts++
continue
}
if peer != nil {
if peer.PktProcess(buf[:n], tap, true) {
timeouts = 0
} else {
log.Println("Unauthenticated packet")
timeouts++
}
if atomic.LoadInt64(&peer.BytesIn)+atomic.LoadInt64(&peer.BytesOut) > govpn.MaxBytesPerKey {
log.Println("Need rehandshake")
rehandshaking <- struct{}{}
break MainCycle
}
continue
}
if idsCache.Find(buf[:n]) == nil {
log.Println("Invalid identity in handshake packet")
continue
}
timeouts = 0
peer = hs.Client(buf[:n])
if peer == nil {
continue
}
log.Println("Handshake completed")
knownPeers = govpn.KnownPeers(map[string]**govpn.Peer{*remoteAddr: &peer})
if firstUpCall {
go govpn.ScriptCall(*upPath, *ifaceName)
firstUpCall = false
}
hs.Zero()
terminator = make(chan struct{})
go func() {
heartbeat := time.NewTicker(peer.Timeout)
var data []byte
Processor:
for {
select {
case <-heartbeat.C:
peer.EthProcess(nil)
case <-terminator:
break Processor
case data = <-tap.Sink:
peer.EthProcess(data)
}
}
heartbeat.Stop()
peer.Zero()
}()
}
if terminator != nil {
terminator <- struct{}{}
}
if hs != nil {
hs.Zero()
}
conn.Close()
}