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 // +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         if operr != nil {
  28                 return n, operr
  29         }
  30         return n, nil
  31 }
  32
  33 func writeRawConn(c syscall.RawConn, b []byte) error {
  34         var operr error
  35         err := c.Write(func(s uintptr) bool {
  36                 _, operr = syscall.Write(int(s), b)
  37                 if operr == syscall.EAGAIN {
  38                         return false
  39                 }
  40                 return true
  41         })
  42         if err != nil {
  43                 return err
  44         }
  45         if operr != nil {
  46                 return operr
  47         }
  48         return nil
  49 }
  50
  51 func controlRawConn(c syscall.RawConn, addr Addr) error {
  52         var operr error
  53         fn := func(s uintptr) {
  54                 _, operr = syscall.GetsockoptInt(int(s), syscall.SOL_SOCKET, syscall.SO_REUSEADDR)
  55                 if operr != nil {
  56                         return
  57                 }
  58                 switch addr := addr.(type) {
  59                 case *TCPAddr:
  60                         // There's no guarantee that IP-level socket
  61                         // options work well with dual stack sockets.
  62                         // A simple solution would be to take a look
  63                         // at the bound address to the raw connection
  64                         // and to classify the address family of the
  65                         // underlying socket by the bound address:
  66                         //
  67                         // - When IP.To16() != nil and IP.To4() == nil,
  68                         //   we can assume that the raw connection
  69                         //   consists of an IPv6 socket using only
  70                         //   IPv6 addresses.
  71                         //
  72                         // - When IP.To16() == nil and IP.To4() != nil,
  73                         //   the raw connection consists of an IPv4
  74                         //   socket using only IPv4 addresses.
  75                         //
  76                         // - Otherwise, the raw connection is a dual
  77                         //   stack socket, an IPv6 socket using IPv6
  78                         //   addresses including IPv4-mapped or
  79                         //   IPv4-embedded IPv6 addresses.
  80                         if addr.IP.To16() != nil && addr.IP.To4() == nil {
  81                                 operr = syscall.SetsockoptInt(int(s), syscall.IPPROTO_IPV6, syscall.IPV6_UNICAST_HOPS, 1)
  82                         } else if addr.IP.To16() == nil && addr.IP.To4() != nil {
  83                                 operr = syscall.SetsockoptInt(int(s), syscall.IPPROTO_IP, syscall.IP_TTL, 1)
  84                         }
  85                 }
  86         }
  87         if err := c.Control(fn); err != nil {
  88                 return err
  89         }
  90         if operr != nil {
  91                 return operr
  92         }
  93         return nil
  94 }
  95
  96 func controlOnConnSetup(network string, address string, c syscall.RawConn) error {
  97         var operr error
  98         var fn func(uintptr)
  99         switch network {
 100         case "tcp", "udp", "ip":
 101                 return errors.New("ambiguous network: " + network)
 102         case "unix", "unixpacket", "unixgram":
 103                 fn = func(s uintptr) {
 104                         _, operr = syscall.GetsockoptInt(int(s), syscall.SOL_SOCKET, syscall.SO_ERROR)
 105                 }
 106         default:
 107                 switch network[len(network)-1] {
 108                 case '4':
 109                         fn = func(s uintptr) {
 110                                 operr = syscall.SetsockoptInt(int(s), syscall.IPPROTO_IP, syscall.IP_TTL, 1)
 111                         }
 112                 case '6':
 113                         fn = func(s uintptr) {
 114                                 operr = syscall.SetsockoptInt(int(s), syscall.IPPROTO_IPV6, syscall.IPV6_UNICAST_HOPS, 1)
 115                         }
 116                 default:
 117                         return errors.New("unknown network: " + network)
 118                 }
 119         }
 120         if err := c.Control(fn); err != nil {
 121                 return err
 122         }
 123         if operr != nil {
 124                 return operr
 125         }
 126         return nil
 127 }