2 GoVPN -- simple secure free software virtual private network daemon
3 Copyright (C) 2014-2016 Sergey Matveev <stargrave@stargrave.org>
5 This program is free software: you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation, either version 3 of the License, or
8 (at your option) any later version.
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
32 MTUDefault = 1500 + 14
39 // Call external program/script.
40 // You have to specify path to it and (inteface name as a rule) something
41 // that will be the first argument when calling it. Function will return
42 // it's output and possible error.
43 func ScriptCall(path, ifaceName string) ([]byte, error) {
47 if _, err := os.Stat(path); err != nil && os.IsNotExist(err) {
50 out, err := exec.Command(path, ifaceName).CombinedOutput()
52 log.Println("Script error", path, err, string(out))
58 func SliceZero(data []byte) {
59 for i := 0; i < len(data); i++ {
64 func VersionGet() string {
65 return "GoVPN version " + Version + " built with " + runtime.Version()
68 func cprCycleCalculate(rate int) time.Duration {
70 return time.Duration(0)
72 return time.Second / time.Duration(rate*(1<<10)/MTUMax)