package yggdrasil // This manages the tun driver to send/recv packets to/from applications import water "github.com/songgao/water" const IPv6_HEADER_LENGTH = 40 type tunDevice struct { core *Core send chan<- []byte recv <-chan []byte mtu int iface *water.Interface } func (tun *tunDevice) init(core *Core) { tun.core = core } func (tun *tunDevice) write() error { for { data := <-tun.recv if _, err := tun.iface.Write(data); err != nil { return err } util_putBytes(data) } } func (tun *tunDevice) read() error { buf := make([]byte, tun.mtu) for { n, err := tun.iface.Read(buf) if err != nil { return err } if buf[0]&0xf0 != 0x60 || n != 256*int(buf[4])+int(buf[5])+IPv6_HEADER_LENGTH { // Either not an IPv6 packet or not the complete packet for some reason //panic("Should not happen in testing") continue } packet := append(util_getBytes(), buf[:n]...) tun.send <- packet } } func (tun *tunDevice) close() error { return tun.iface.Close() }