libgo/go/net/rawconn_unix_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 //go:build aix || darwin || dragonfly || freebsd || hurd || linux || netbsd || openbsd || solaris
   6
   7 package net
   8
   9 import (
  10         "errors"
  11         "syscall"
  12 )
  13
  14 func readRawConn(c syscall.RawConn, b []byte) (int, error) {
  15         var operr error
  16         var n int
  17         err := c.Read(func(s uintptr) bool {
  18                 n, operr = syscall.Read(int(s), b)
  19                 if operr == syscall.EAGAIN {
  20                         return false
  21                 }
  22                 return true
  23         })
  24         if err != nil {
  25                 return n, err
  26         }
  27         return n, operr
  28 }
  29
  30 func writeRawConn(c syscall.RawConn, b []byte) error {
  31         var operr error
  32         err := c.Write(func(s uintptr) bool {
  33                 _, operr = syscall.Write(int(s), b)
  34                 if operr == syscall.EAGAIN {
  35                         return false
  36                 }
  37                 return true
  38         })
  39         if err != nil {
  40                 return err
  41         }
  42         return operr
  43 }
  44
  45 func controlRawConn(c syscall.RawConn, addr Addr) error {
  46         var operr error
  47         fn := func(s uintptr) {
  48                 _, operr = syscall.GetsockoptInt(int(s), syscall.SOL_SOCKET, syscall.SO_REUSEADDR)
  49                 if operr != nil {
  50                         return
  51                 }
  52                 switch addr := addr.(type) {
  53                 case *TCPAddr:
  54                         // There's no guarantee that IP-level socket
  55                         // options work well with dual stack sockets.
  56                         // A simple solution would be to take a look
  57                         // at the bound address to the raw connection
  58                         // and to classify the address family of the
  59                         // underlying socket by the bound address:
  60                         //
  61                         // - When IP.To16() != nil and IP.To4() == nil,
  62                         //   we can assume that the raw connection
  63                         //   consists of an IPv6 socket using only
  64                         //   IPv6 addresses.
  65                         //
  66                         // - When IP.To16() == nil and IP.To4() != nil,
  67                         //   the raw connection consists of an IPv4
  68                         //   socket using only IPv4 addresses.
  69                         //
  70                         // - Otherwise, the raw connection is a dual
  71                         //   stack socket, an IPv6 socket using IPv6
  72                         //   addresses including IPv4-mapped or
  73                         //   IPv4-embedded IPv6 addresses.
  74                         if addr.IP.To16() != nil && addr.IP.To4() == nil {
  75                                 operr = syscall.SetsockoptInt(int(s), syscall.IPPROTO_IPV6, syscall.IPV6_UNICAST_HOPS, 1)
  76                         } else if addr.IP.To16() == nil && addr.IP.To4() != nil {
  77                                 operr = syscall.SetsockoptInt(int(s), syscall.IPPROTO_IP, syscall.IP_TTL, 1)
  78                         }
  79                 }
  80         }
  81         if err := c.Control(fn); err != nil {
  82                 return err
  83         }
  84         return operr
  85 }
  86
  87 func controlOnConnSetup(network string, address string, c syscall.RawConn) error {
  88         var operr error
  89         var fn func(uintptr)
  90         switch network {
  91         case "tcp", "udp", "ip":
  92                 return errors.New("ambiguous network: " + network)
  93         case "unix", "unixpacket", "unixgram":
  94                 fn = func(s uintptr) {
  95                         _, operr = syscall.GetsockoptInt(int(s), syscall.SOL_SOCKET, syscall.SO_ERROR)
  96                 }
  97         default:
  98                 switch network[len(network)-1] {
  99                 case '4':
 100                         fn = func(s uintptr) {
 101                                 operr = syscall.SetsockoptInt(int(s), syscall.IPPROTO_IP, syscall.IP_TTL, 1)
 102                         }
 103                 case '6':
 104                         fn = func(s uintptr) {
 105                                 operr = syscall.SetsockoptInt(int(s), syscall.IPPROTO_IPV6, syscall.IPV6_UNICAST_HOPS, 1)
 106                         }
 107                 default:
 108                         return errors.New("unknown network: " + network)
 109                 }
 110         }
 111         if err := c.Control(fn); err != nil {
 112                 return err
 113         }
 114         return operr
 115 }