github.com/psiphon-labs/psiphon-tunnel-core@v2.0.28+incompatible/psiphon/net_windows.go (about)

     1  //go:build windows
     2  // +build windows
     3  
     4  /*
     5   * Copyright (c) 2022, Psiphon Inc.
     6   * All rights reserved.
     7   *
     8   * This program is free software: you can redistribute it and/or modify
     9   * it under the terms of the GNU General Public License as published by
    10   * the Free Software Foundation, either version 3 of the License, or
    11   * (at your option) any later version.
    12   *
    13   * This program is distributed in the hope that it will be useful,
    14   * but WITHOUT ANY WARRANTY; without even the implied warranty of
    15   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    16   * GNU General Public License for more details.
    17   *
    18   * You should have received a copy of the GNU General Public License
    19   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    20   *
    21   */
    22  
    23  package psiphon
    24  
    25  import (
    26  	"context"
    27  	"net"
    28  	"strconv"
    29  	"syscall"
    30  
    31  	"github.com/Psiphon-Labs/psiphon-tunnel-core/psiphon/common/errors"
    32  	"golang.org/x/net/bpf"
    33  )
    34  
    35  func ClientBPFEnabled() bool {
    36  	return false
    37  }
    38  
    39  func setSocketBPF(_ []bpf.RawInstruction, _ int) error {
    40  	return errors.TraceNew("BPF not supported")
    41  }
    42  
    43  func setAdditionalSocketOptions(_ int) {
    44  }
    45  
    46  func makeLocalProxyListener(listenIP string, port int) (net.Listener, bool, error) {
    47  	listenConfig := net.ListenConfig{
    48  		Control: func(_, _ string, c syscall.RawConn) error {
    49  			var controlErr error
    50  			err := c.Control(func(fd uintptr) {
    51  
    52  				if listenIP != "0.0.0.0" && listenIP != "::" {
    53  					return
    54  				}
    55  
    56  				// When binding to a wildcard IP address, 0.0.0.0 or ::, set
    57  				// SO_EXCLUSIVEADDRUSE since Windows, in this case, otherwise
    58  				// allows other programs to bind to a specific IP address
    59  				// (e.g., 127.0.0.1) with the same port number and we'll
    60  				// unexpectedly lose our port binding.
    61  				//
    62  				// SO_EXCLUSIVEADDRUSE is not necessary in the non-wildcard
    63  				// case, as Windows will cause conflicting bind calls to
    64  				// fail.
    65  
    66  				// SO_EXCLUSIVEADDRUSE isn't defined in syscall. This is the
    67  				// definition from Winsock2.h.
    68  				SO_EXCLUSIVEADDRUSE := ^syscall.SO_REUSEADDR
    69  
    70  				controlErr = syscall.SetsockoptInt(
    71  					syscall.Handle(fd),
    72  					syscall.SOL_SOCKET,
    73  					SO_EXCLUSIVEADDRUSE,
    74  					1)
    75  			})
    76  			if controlErr != nil {
    77  				return errors.Trace(controlErr)
    78  			}
    79  			return errors.Trace(err)
    80  		},
    81  	}
    82  	listener, err := listenConfig.Listen(
    83  		context.Background(), "tcp", net.JoinHostPort(listenIP, strconv.Itoa(port)))
    84  	if err != nil {
    85  		return nil, IsAddressInUseError(err), errors.Trace(err)
    86  	}
    87  	return listener, false, nil
    88  }