func argsCheck() *tunnel.Options {
var options tunnel.Options
var tgw string
var rc4Key string
flag.BoolVar(&options.TunnelServer, "tunnel_server", false, "work as tunnel server or client")
flag.BoolVar(&options.Front, "front", false, "work as front door or back door")
flag.StringVar(&tgw, "tgw", "", "tgw header")
flag.StringVar(&rc4Key, "rc4", "the answer to life, the universe and everything", "rc4 key, disable if no key")
flag.StringVar(&options.FrontAddr, "front_addr", "0.0.0.0:8001", "front door address(0.0.0.0:8001)")
flag.StringVar(&options.TunnelAddr, "tunnel_addr", "0.0.0.0:8002", "tunnel door address(0.0.0.0:8002)")
flag.IntVar(&options.LogLevel, "log", 1, "larger value for detail log")
flag.Usage = usage
flag.Parse()
options.Capacity = 65535
options.Tgw = bytes.ToLower([]byte(tgw))
options.Rc4Key = []byte(rc4Key)
if len(options.Rc4Key) > 256 {
fmt.Println("rc4 key at most 256 bytes")
os.Exit(1)
}
if !options.Front {
args := flag.Args()
if len(args) < 1 {
usage()
} else {
options.ConfigFile = args[0]
}
}
return &options
}
