func main() {
ifce, err := water.NewTAP("tap0")
fmt.Printf("%v, %v\n\n", err, ifce)
buffer := make([]byte, BUFFERSIZE)
for {
_, err = ifce.Read(buffer)
if err != nil {
fmt.Printf("err = %v\n", err)
break
}
ethertype := waterutil.MACEthertype(buffer)
fmt.Printf("ethertype = %#v\n", ethertype)
if ethertype == waterutil.IPv4 {
packet := waterutil.MACPayload(buffer)
if waterutil.IsIPv4(packet) {
fmt.Printf("IPv4 Source: %v [%v]\n", waterutil.MACSource(buffer), waterutil.IPv4Source(packet))
fmt.Printf("IPv4 Destination: %v [%v]\n", waterutil.MACDestination(buffer), waterutil.IPv4Destination(packet))
fmt.Printf("IPv4 Protocol: %v\n\n", waterutil.IPv4Protocol(packet))
} else if waterutil.IsIPv6(packet) {
fmt.Printf("IPv6 Source: %v\n", waterutil.MACSource(buffer))
fmt.Printf("IPv6 Destination: %v\n\n", waterutil.MACDestination(buffer))
} else {
fmt.Printf("unknow Source: %v\n", waterutil.MACSource(buffer))
fmt.Printf("unknow Destination: %v\n\n", waterutil.MACDestination(buffer))
}
}
}
}
func updateChecksum(datagram []byte) {
ipv4_hdr_len := 4 * (datagram[0] & 0x0F)
datagram[ipv4_hdr_len+16] = 0
datagram[ipv4_hdr_len+17] = 0
csum := Csum(datagram[ipv4_hdr_len:],
IPTo4le(waterutil.IPv4Source(datagram)),
IPTo4le(waterutil.IPv4Destination(datagram)))
datagram[ipv4_hdr_len+16] = (byte)(csum >> 8)
datagram[ipv4_hdr_len+17] = (byte)(csum & 0xFF)
}
func TestBroadcast(t *testing.T) {
var (
self = net.IPv4(10, 0, 42, 1)
mask = net.IPv4Mask(255, 255, 255, 0)
brd = net.IPv4(10, 0, 42, 255)
)
ifce, err := NewTAP("test")
if err != nil {
t.Fatalf("creating TAP error: %v\n", err)
}
setupIfce(t, net.IPNet{IP: self, Mask: mask}, ifce.Name())
startBroadcast(t, brd)
dataCh := make(chan []byte, 8)
startRead(dataCh, ifce)
timeout := time.NewTimer(8 * time.Second).C
readFrame:
for {
select {
case buffer := <-dataCh:
ethertype := waterutil.MACEthertype(buffer)
if ethertype != waterutil.IPv4 {
continue readFrame
}
if !waterutil.IsBroadcast(waterutil.MACDestination(buffer)) {
continue readFrame
}
packet := waterutil.MACPayload(buffer)
if !waterutil.IsIPv4(packet) {
continue readFrame
}
if !waterutil.IPv4Source(packet).Equal(self) {
continue readFrame
}
if !waterutil.IPv4Destination(packet).Equal(brd) {
continue readFrame
}
if waterutil.IPv4Protocol(packet) != waterutil.ICMP {
continue readFrame
}
t.Logf("received broadcast frame: %#v\n", buffer)
break readFrame
case <-timeout:
t.Fatal("Waiting for broadcast packet timeout")
}
}
}
func HostProxy() {
file, e := ioutil.ReadFile(*config_path)
if e != nil {
l_err.Printf("Config file open error: %v\n", e)
os.Exit(1)
}
var config Config
e_parse := json.Unmarshal(file, &config)
if e_parse != nil {
l_err.Printf("Config parse error: %v\n", e_parse)
os.Exit(1)
}
// Get interface IP
config_interface_ip := config.Proxy.SourceIP
raw_sock, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_RAW, syscall.IPPROTO_RAW)
if err != nil {
panic(err)
}
err = syscall.SetsockoptInt(raw_sock, syscall.IPPROTO_IP, syscall.IP_HDRINCL, 1)
if err != nil {
panic(err)
}
// Length byte order
cmd_stdoutQueue := make(chan interface{}, 10)
cmd_stdinQueue := make(chan interface{}, 10)
SpawnNodeSubprocess(*config_path, cmd_stdoutQueue, cmd_stdinQueue)
proxy := NewProxyState()
go proxy.doListen(syscall.IPPROTO_TCP)
go proxy.doListen(syscall.IPPROTO_UDP)
go func() {
for {
datagram := <-proxy.messages_to_send
waterutil.SetIPv4Source(datagram, config_interface_ip)
updateChecksum(datagram)
destinationIP := waterutil.IPv4Destination(datagram)
// Reverse byte order of IP for host byte order
destinationIP4 := destinationIP.To4()
dstAddrHost := [4]byte{destinationIP4[3], destinationIP4[2], destinationIP4[1], destinationIP4[0]}
dstAddr := syscall.SockaddrInet4{Addr: dstAddrHost}
// Swap header length byte order, for host byte order
{
x := datagram[2]
datagram[2] = datagram[3]
datagram[3] = x
}
err = syscall.Sendto(raw_sock, datagram, 0, &dstAddr)
if err != nil {
fmt.Fprintf(os.Stderr, "Error on sendto(): %v\n", err)
}
}
}()
// Process messages coming from node
for {
select {
case datagram := <-proxy.messages_received:
{
local_port := LocalPort{
binary.BigEndian.Uint32(waterutil.IPv4Destination(datagram)),
waterutil.IPv4DestinationPort(datagram),
// TODO: UDP
waterutil.TCP,
}
fmt.Fprintf(os.Stderr, "Main loop recvd from %v: %v\n", local_port, datagram)
if source_port, exists := proxy.source_ports_by_local_ports[local_port]; exists {
fmt.Fprintf(os.Stderr, "--- Exists\n")
cmd_stdinQueue <- Stdin_SendBack{mesh.MeshMessage{source_port.SendId, source_port.ConnectedPeer, []byte{}}, datagram}
}
}
case msg_out := <-cmd_stdoutQueue:
{
if reflect.TypeOf(msg_out) == reflect.TypeOf(Stdout_RecvMessage{}) {
recv_msg := msg_out.(Stdout_RecvMessage)
datagram := recv_msg.Contents
protocol := waterutil.IPv4Protocol(datagram)
if protocol == waterutil.TCP || protocol == waterutil.UDP {
source := SourcePort{
recv_msg.SendId,
recv_msg.ConnectedPeer,
waterutil.IPv4SourcePort(datagram),
binary.BigEndian.Uint32(waterutil.IPv4Source(datagram)),
protocol,
}
port := proxy.portForSource(source)
destinationIP := waterutil.IPv4Destination(datagram)
fmt.Fprintf(os.Stderr, "\n<<<<<<<<<<< recv from source: %v use port %v dst %s\n", source, port, destinationIP)
waterutil.SetIPv4SourcePort(datagram, port.Port)
srcIP := make([]byte, 4)
binary.LittleEndian.PutUint32(srcIP, port.IP)
waterutil.SetIPv4Source(datagram, srcIP)
waterutil.ZeroIPv4Checksum(datagram)
proxy.messages_to_send <- datagram
}
}
}
}
}
}