package helper import ( "log" "net" "os" "regexp" "strconv" ) const ( // TODO: this is the nameserver for tcp, but for udp is 10.42.0.1 // the nameserver pick up should be dependent on the proto being used nameserver = "10.41.0.1" ) var ( fixedArgs = []string{ "--nobind", "--client", "--dev", "tun", "--tls-client", "--remote-cert-tls", "server", "--dhcp-option", "DNS", nameserver, "--log", LogFolder + "openvpn.log", "--tls-version-min", "1.0", } allowendArgs = map[string][]string{ "--remote": []string{"IP", "NUMBER", "PROTO"}, "--tls-cipher": []string{"CIPHER"}, "--cipher": []string{"CIPHER"}, "--auth": []string{"CIPHER"}, "--management-client": []string{}, "--management": []string{"IP", "NUMBER"}, "--cert": []string{"FILE"}, "--key": []string{"FILE"}, "--ca": []string{"FILE"}, "--fragment": []string{"NUMBER"}, "--keepalive": []string{"NUMBER", "NUMBER"}, "--verb": []string{"NUMBER"}, "--tun-ipv6": []string{}, } cipher = regexp.MustCompile("^[A-Z0-9-]+$") formats = map[string]func(s string) bool{ "NUMBER": isNumber, "PROTO": isProto, "IP": isIP, "CIPHER": cipher.MatchString, "FILE": isFile, } ) func parseOpenvpnArgs(args []string) []string { newArgs := fixedArgs newArgs = append(newArgs, platformOpenvpnFlags...) for i := 0; i < len(args); i++ { params, ok := allowendArgs[args[i]] if !ok { log.Printf("Invalid openvpn arg: %s", args[i]) continue } for j, arg := range args[i+1 : i+len(params)+1] { if !formats[params[j]](arg) { ok = false break } } if ok { newArgs = append(newArgs, args[i:i+len(params)+1]...) i = i + len(params) } else { log.Printf("Invalid openvpn arg params: %v", args[i:i+len(params)+1]) } } return newArgs } func isNumber(s string) bool { _, err := strconv.Atoi(s) return err == nil } func isProto(s string) bool { for _, proto := range []string{"tcp", "udp", "tcp4", "udp4", "tcp6", "udp6"} { if s == proto { return true } } return false } func isIP(s string) bool { return net.ParseIP(s) != nil } func isFile(s string) bool { info, err := os.Stat(s) if err != nil { return false } return !info.IsDir() }