rawconn_windows_test.go

     1  // Copyright 2017 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package net
     6  
     7  import (
     8  	"errors"
     9  	"syscall"
    10  	"unsafe"
    11  )
    12  
    13  func readRawConn(c syscall.RawConn, b []byte) (int, error) {
    14  	var operr error
    15  	var n int
    16  	err := c.Read(func(s uintptr) bool {
    17  		var read uint32
    18  		var flags uint32
    19  		var buf syscall.WSABuf
    20  		buf.Buf = &b[0]
    21  		buf.Len = uint32(len(b))
    22  		operr = syscall.WSARecv(syscall.Handle(s), &buf, 1, &read, &flags, nil, nil)
    23  		n = int(read)
    24  		return true
    25  	})
    26  	if err != nil {
    27  		return n, err
    28  	}
    29  	return n, operr
    30  }
    31  
    32  func writeRawConn(c syscall.RawConn, b []byte) error {
    33  	var operr error
    34  	err := c.Write(func(s uintptr) bool {
    35  		var written uint32
    36  		var buf syscall.WSABuf
    37  		buf.Buf = &b[0]
    38  		buf.Len = uint32(len(b))
    39  		operr = syscall.WSASend(syscall.Handle(s), &buf, 1, &written, 0, nil, nil)
    40  		return true
    41  	})
    42  	if err != nil {
    43  		return err
    44  	}
    45  	return operr
    46  }
    47  
    48  func controlRawConn(c syscall.RawConn, addr Addr) error {
    49  	var operr error
    50  	fn := func(s uintptr) {
    51  		var v, l int32
    52  		l = int32(unsafe.Sizeof(v))
    53  		operr = syscall.Getsockopt(syscall.Handle(s), syscall.SOL_SOCKET, syscall.SO_REUSEADDR, (*byte)(unsafe.Pointer(&v)), &l)
    54  		if operr != nil {
    55  			return
    56  		}
    57  		switch addr := addr.(type) {
    58  		case *TCPAddr:
    59  			// There's no guarantee that IP-level socket
    60  			// options work well with dual stack sockets.
    61  			// A simple solution would be to take a look
    62  			// at the bound address to the raw connection
    63  			// and to classify the address family of the
    64  			// underlying socket by the bound address:
    65  			//
    66  			// - When IP.To16() != nil and IP.To4() == nil,
    67  			//   we can assume that the raw connection
    68  			//   consists of an IPv6 socket using only
    69  			//   IPv6 addresses.
    70  			//
    71  			// - When IP.To16() == nil and IP.To4() != nil,
    72  			//   the raw connection consists of an IPv4
    73  			//   socket using only IPv4 addresses.
    74  			//
    75  			// - Otherwise, the raw connection is a dual
    76  			//   stack socket, an IPv6 socket using IPv6
    77  			//   addresses including IPv4-mapped or
    78  			//   IPv4-embedded IPv6 addresses.
    79  			if addr.IP.To16() != nil && addr.IP.To4() == nil {
    80  				operr = syscall.SetsockoptInt(syscall.Handle(s), syscall.IPPROTO_IPV6, syscall.IPV6_UNICAST_HOPS, 1)
    81  			} else if addr.IP.To16() == nil && addr.IP.To4() != nil {
    82  				operr = syscall.SetsockoptInt(syscall.Handle(s), syscall.IPPROTO_IP, syscall.IP_TTL, 1)
    83  			}
    84  		}
    85  	}
    86  	if err := c.Control(fn); err != nil {
    87  		return err
    88  	}
    89  	return operr
    90  }
    91  
    92  func controlOnConnSetup(network string, address string, c syscall.RawConn) error {
    93  	var operr error
    94  	var fn func(uintptr)
    95  	switch network {
    96  	case "tcp", "udp", "ip":
    97  		return errors.New("ambiguous network: " + network)
    98  	default:
    99  		switch network[len(network)-1] {
   100  		case '4':
   101  			fn = func(s uintptr) {
   102  				operr = syscall.SetsockoptInt(syscall.Handle(s), syscall.IPPROTO_IP, syscall.IP_TTL, 1)
   103  			}
   104  		case '6':
   105  			fn = func(s uintptr) {
   106  				operr = syscall.SetsockoptInt(syscall.Handle(s), syscall.IPPROTO_IPV6, syscall.IPV6_UNICAST_HOPS, 1)
   107  			}
   108  		default:
   109  			return errors.New("unknown network: " + network)
   110  		}
   111  	}
   112  	if err := c.Control(fn); err != nil {
   113  		return err
   114  	}
   115  	return operr
   116  }
   117
View as plain text