"encoding/hex"
"flag"
"fmt"
+ "io"
"log"
"net"
"time"
"code.google.com/p/go.crypto/poly1305"
"code.google.com/p/go.crypto/salsa20"
- "github.com/chon219/water"
+)
+
+var (
+ remoteAddr = flag.String("remote", "", "Remote server address")
+ bindAddr = flag.String("bind", "", "Bind to address")
+ ifaceName = flag.String("iface", "tap0", "TAP network interface")
+ keyHex = flag.String("key", "", "Authentication key")
+ mtu = flag.Int("mtu", 1500, "MTU")
+ timeout = flag.Int("timeout", 60, "Timeout seconds")
+ verbose = flag.Bool("v", false, "Increase verbosity")
)
const (
- NonceSize = 8
- AliveTimeout = time.Second * 90
- KeySize = 32
+ NonceSize = 8
+ KeySize = 32
// S20BS is Salsa20's internal blocksize in bytes
S20BS = 64
)
+type TAP interface {
+ io.Reader
+ io.Writer
+}
+
type Peer struct {
addr *net.UDPAddr
- lastPing time.Time
key *[KeySize]byte // encryption key
- nonceOur uint64 // nonce for our messages
- nonceRecv uint64 // latest received nonce from remote peer
-}
-
-func (p *Peer) IsAlive() bool {
- if (p == nil) || (p.lastPing.Add(AliveTimeout).Before(time.Now())) {
- return false
- }
- return true
-}
-
-func (p *Peer) SetAlive() {
- p.lastPing = time.Now()
+ nonceOur uint64 // nonce for our messages
+ nonceRecv uint64 // latest received nonce from remote peer
}
type UDPPkt struct {
size int
}
-var (
- remoteAddr = flag.String("remote", "", "Remote server address")
- bindAddr = flag.String("bind", "", "Bind to address")
- ifaceName = flag.String("iface", "tap0", "TAP network interface")
- keyHex = flag.String("key", "", "Authentication key")
- mtu = flag.Int("mtu", 1500, "MTU")
- verbose = flag.Bool("v", false, "Increase verbosity")
-)
-
func main() {
flag.Parse()
log.SetFlags(log.Ldate | log.Lmicroseconds | log.Lshortfile)
// Interface listening
maxIfacePktSize := *mtu - poly1305.TagSize - NonceSize
log.Println("Max MTU", maxIfacePktSize, "on interface", *ifaceName)
- iface, err := water.NewTAP(*ifaceName)
- if err != nil {
- panic(err)
- }
+ iface := NewTAP(*ifaceName)
ethBuf := make([]byte, maxIfacePktSize)
ethSink := make(chan int)
ethSinkReady := make(chan bool)
go func() {
for {
- <- ethSinkReady
+ <-ethSinkReady
n, err := iface.Read(ethBuf)
if err != nil {
panic(err)
}
udpBuf := make([]byte, *mtu)
- udpSink := make(chan UDPPkt)
+ udpSink := make(chan *UDPPkt)
udpSinkReady := make(chan bool)
go func(conn *net.UDPConn) {
for {
- <- udpSinkReady
+ <-udpSinkReady
+ conn.SetReadDeadline(time.Now().Add(time.Second))
n, addr, err := conn.ReadFromUDP(udpBuf)
if err != nil {
- fmt.Print("B")
+ if *verbose {
+ fmt.Print("B")
+ }
+ udpSink <- nil
+ } else {
+ udpSink <- &UDPPkt{addr, n}
}
- udpSink <- UDPPkt{addr, n}
}
}(conn)
udpSinkReady <- true
// Process packets
- var udpPkt UDPPkt
+ var udpPkt *UDPPkt
var udpPktData []byte
var ethPktSize int
var addr string
- var peer Peer
+ var peer *Peer
var p *Peer
+ timeouts := 0
states := make(map[string]*Handshake)
nonce := make([]byte, NonceSize)
keyAuth := new([KeySize]byte)
udpPktDataBuf := make([]byte, *mtu)
if !serverMode {
- log.Println("starting handshake with", *remoteAddr)
states[remote.String()] = HandshakeStart(conn, remote, key)
}
+ finished := false
for {
+ if finished {
+ break
+ }
select {
case udpPkt = <-udpSink:
+ timeouts++
+ if !serverMode && timeouts >= *timeout {
+ finished = true
+ }
+ if udpPkt == nil {
+ udpSinkReady <- true
+ continue
+ }
copy(udpPktDataBuf, udpBuf[:udpPkt.size])
udpSinkReady <- true
udpPktData = udpPktDataBuf[:udpPkt.size]
}
if p != nil {
fmt.Print("[HS-OK]")
- peer = *p
+ peer = p
delete(states, addr)
}
continue
}
- if !peer.IsAlive() {
+ if peer == nil {
continue
}
nonceRecv, _ := binary.Uvarint(udpPktData[:8])
continue
}
peer.nonceRecv = nonceRecv
- peer.SetAlive()
+ timeouts = 0
if _, err := iface.Write(buf[S20BS : S20BS+udpPkt.size-NonceSize-poly1305.TagSize]); err != nil {
- log.Println("Error writing to iface")
+ log.Println("Error writing to iface: ", err)
}
if *verbose {
fmt.Print("r")
if ethPktSize > maxIfacePktSize {
panic("Too large packet on interface")
}
- if !peer.IsAlive() {
+ if peer == nil {
ethSinkReady <- true
continue
}