func (c *Client) handleUDP(err_chan chan error) {
defer c.serverConnection.Close()
for {
buf := make([]byte, 1600)
n, err := c.serverConnection.Read(buf)
log.Printf("%s -> %s", c.serverConnection.RemoteAddr().String(), c.device.String())
if err != nil {
err_chan <- err
return
}
buf, err = crypto.Decrypt(c.secretKey, buf[:n])
if err != nil {
err_chan <- err
return
}
msg := &message.Message{}
err = proto.Unmarshal(buf, msg)
if err != nil {
err_chan <- err
return
}
if *msg.Kind != message.Message_DATA {
err = errors.New("Unexpected message type.")
err_chan <- err
return
}
err = c.device.Write(msg.Data)
if err != nil {
err_chan <- err
return
}
}
}
func (s *Server) handleUDP(err_chan chan error) {
defer s.listenerConnection.Close()
for {
buf := make([]byte, 2000)
n, addr, err := s.listenerConnection.ReadFromUDP(buf)
if err != nil {
err_chan <- err
return
}
buf = buf[:n]
buf, err = crypto.Decrypt(s.secretKey, buf)
if err != nil {
err_chan <- err
return
}
msg := &message.Message{}
err = proto.Unmarshal(buf, msg)
if err != nil {
err_chan <- err
return
}
switch *msg.Kind {
case message.Message_REQUEST:
ip := s.sessionTable.NewClient(addr)
data := make([]byte, 4)
binary.BigEndian.PutUint32(data, ip)
msg = &message.Message{
Kind: message.Message_ACCEPT.Enum(),
Data: data,
}
data, err = proto.Marshal(msg)
if err != nil {
err_chan <- err
return
}
data, err = crypto.Encrypt(s.secretKey, data)
if err != nil {
err_chan <- err
return
}
_, err = s.listenerConnection.WriteToUDP(data, addr)
if err != nil {
err_chan <- err
return
}
case message.Message_DATA:
pkt := msg.Data
err = s.device.Write(pkt)
if err != nil {
err_chan <- err
return
}
default:
err_chan <- errors.New("Unknown message type.")
return
}
}
}
func (c *Client) init() error {
msg := &message.Message{
Kind: message.Message_REQUEST.Enum(),
}
log.Printf("Sending request to %s.", c.serverConnection.RemoteAddr().String())
data, err := proto.Marshal(msg)
if err != nil {
return err
}
data, err = crypto.Encrypt(c.secretKey, data)
if err != nil {
return err
}
success := false
buf := make([]byte, 1600)
for !success {
_, err = c.serverConnection.Write(data)
if err != nil {
return err
}
c.serverConnection.SetReadDeadline(time.Now().Add(5 * time.Second))
n, err := c.serverConnection.Read(buf)
c.serverConnection.SetReadDeadline(time.Time{})
if err != nil {
log.Printf("Read error: %v. Reconnecting...", err)
continue
}
buf = buf[:n]
success = true
}
buf, err = crypto.Decrypt(c.secretKey, buf)
if err != nil {
return err
}
msg = &message.Message{}
err = proto.Unmarshal(buf, msg)
if *msg.Kind != message.Message_ACCEPT {
return errors.New("Unexpected message type.")
}
var local_ip net.IP
local_ip = msg.Data
log.Printf("Client IP %s assigned.", local_ip.String())
c.device, err = tun.NewTun(DeviceNameClient, local_ip.String())
if err != nil {
return err
}
local_ip[3] = 0x1
c.gatewayAddress, err = util.DefaultGateway()
if err != nil {
return err
}
err = util.SetGatewayForHost(c.gatewayAddress, c.serverAddress)
if err != nil {
return err
}
err = util.ClearGateway()
if err != nil {
return err
}
err = util.SetDefaultGateway(local_ip.String())
if err != nil {
return err
}
return nil
}