tnet.go - tordam - A library for peer discovery inside the Tor network
HTML git clone https://git.parazyd.org/tordam
DIR Log
DIR Files
DIR Refs
DIR README
DIR LICENSE
---
tnet.go (1291B)
---
1 // Copyright (c) 2017-2021 Ivan Jelincic <parazyd@dyne.org>
2 //
3 // This file is part of tordam
4 //
5 // This program is free software: you can redistribute it and/or modify
6 // it under the terms of the GNU Affero 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.
9 //
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 Affero General Public License for more details.
14 //
15 // You should have received a copy of the GNU Affero General Public License
16 // along with this program. If not, see <https://www.gnu.org/licenses/>.
17
18 package tordam
19
20 import "net"
21
22 // GetAvailableListener is a helper function to return a *net.TCPAddr on some
23 // port that is available for listening on the system. It uses the :0 port
24 // which the kernel utilizes to return a random available port.
25 func GetAvailableListener() (*net.TCPAddr, error) {
26 addr, err := net.ResolveTCPAddr("tcp4", "localhost:0")
27 if err != nil {
28 return nil, err
29 }
30
31 l, err := net.ListenTCP("tcp4", addr)
32 if err != nil {
33 return nil, err
34 }
35 defer l.Close()
36 return l.Addr().(*net.TCPAddr), nil
37 }