github.com/gidoBOSSftw5731/go/src@v0.0.0-20210226122457-d24b0edbf019/net/rawconn_windows_test.go (about) 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 }