github.com/mysteriumnetwork/node@v0.0.0-20240516044423-365054f76801/core/port/availability.go (about)

     1  /*
     2   * Copyright (C) 2019 The "MysteriumNetwork/node" Authors.
     3   *
     4   * This program is free software: you can redistribute it and/or modify
     5   * it under the terms of the GNU General Public License as published by
     6   * the Free Software Foundation, either version 3 of the License, or
     7   * (at your option) any later version.
     8   *
     9   * This program is distributed in the hope that it will be useful,
    10   * but WITHOUT ANY WARRANTY; without even the implied warranty of
    11   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    12   * GNU General Public License for more details.
    13   *
    14   * You should have received a copy of the GNU General Public License
    15   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    16   */
    17  
    18  package port
    19  
    20  import (
    21  	"net"
    22  	"strconv"
    23  
    24  	"github.com/pkg/errors"
    25  	"github.com/rs/zerolog/log"
    26  )
    27  
    28  // Tests port by opening a UDP listener on given port number
    29  func available(port int) (bool, error) {
    30  	addr, err := net.ResolveUDPAddr("udp", ":"+strconv.Itoa(port))
    31  	if err != nil {
    32  		return false, errors.Wrap(err, "unable to resolve UDP address")
    33  	}
    34  
    35  	conn, err := net.ListenUDP("udp", addr)
    36  	if err != nil {
    37  		log.Trace().Err(err).Msgf("Cannot listen on UDP port %d", port)
    38  		return false, nil
    39  	}
    40  	defer conn.Close()
    41  
    42  	return true, nil
    43  }