libgo/go/net/interface_windows.go

   1 // Copyright 2011 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 // Network interface identification for Windows
   6
   7 package net
   8
   9 import (
  10         "os"
  11         "syscall"
  12         "unsafe"
  13 )
  14
  15 func bytePtrToString(p *uint8) string {
  16         a := (*[10000]uint8)(unsafe.Pointer(p))
  17         i := 0
  18         for a[i] != 0 {
  19                 i++
  20         }
  21         return string(a[:i])
  22 }
  23
  24 func getAdapterList() (*syscall.IpAdapterInfo, error) {
  25         b := make([]byte, 1000)
  26         l := uint32(len(b))
  27         a := (*syscall.IpAdapterInfo)(unsafe.Pointer(&b[0]))
  28         err := syscall.GetAdaptersInfo(a, &l)
  29         if err == syscall.ERROR_BUFFER_OVERFLOW {
  30                 b = make([]byte, l)
  31                 a = (*syscall.IpAdapterInfo)(unsafe.Pointer(&b[0]))
  32                 err = syscall.GetAdaptersInfo(a, &l)
  33         }
  34         if err != nil {
  35                 return nil, os.NewSyscallError("GetAdaptersInfo", err)
  36         }
  37         return a, nil
  38 }
  39
  40 func getInterfaceList() ([]syscall.InterfaceInfo, error) {
  41         s, err := syscall.Socket(syscall.AF_INET, syscall.SOCK_DGRAM, syscall.IPPROTO_UDP)
  42         if err != nil {
  43                 return nil, os.NewSyscallError("Socket", err)
  44         }
  45         defer syscall.Closesocket(s)
  46
  47         ii := [20]syscall.InterfaceInfo{}
  48         ret := uint32(0)
  49         size := uint32(unsafe.Sizeof(ii))
  50         err = syscall.WSAIoctl(s, syscall.SIO_GET_INTERFACE_LIST, nil, 0, (*byte)(unsafe.Pointer(&ii[0])), size, &ret, nil, 0)
  51         if err != nil {
  52                 return nil, os.NewSyscallError("WSAIoctl", err)
  53         }
  54         c := ret / uint32(unsafe.Sizeof(ii[0]))
  55         return ii[:c-1], nil
  56 }
  57
  58 // If the ifindex is zero, interfaceTable returns mappings of all
  59 // network interfaces.  Otheriwse it returns a mapping of a specific
  60 // interface.
  61 func interfaceTable(ifindex int) ([]Interface, error) {
  62         ai, err := getAdapterList()
  63         if err != nil {
  64                 return nil, err
  65         }
  66
  67         ii, err := getInterfaceList()
  68         if err != nil {
  69                 return nil, err
  70         }
  71
  72         var ift []Interface
  73         for ; ai != nil; ai = ai.Next {
  74                 index := ai.Index
  75                 if ifindex == 0 || ifindex == int(index) {
  76                         var flags Flags
  77
  78                         row := syscall.MibIfRow{Index: index}
  79                         e := syscall.GetIfEntry(&row)
  80                         if e != nil {
  81                                 return nil, os.NewSyscallError("GetIfEntry", e)
  82                         }
  83
  84                         for _, ii := range ii {
  85                                 ip := (*syscall.RawSockaddrInet4)(unsafe.Pointer(&ii.Address)).Addr
  86                                 ipv4 := IPv4(ip[0], ip[1], ip[2], ip[3])
  87                                 ipl := &ai.IpAddressList
  88                                 for ipl != nil {
  89                                         ips := bytePtrToString(&ipl.IpAddress.String[0])
  90                                         if ipv4.Equal(parseIPv4(ips)) {
  91                                                 break
  92                                         }
  93                                         ipl = ipl.Next
  94                                 }
  95                                 if ipl == nil {
  96                                         continue
  97                                 }
  98                                 if ii.Flags&syscall.IFF_UP != 0 {
  99                                         flags |= FlagUp
 100                                 }
 101                                 if ii.Flags&syscall.IFF_LOOPBACK != 0 {
 102                                         flags |= FlagLoopback
 103                                 }
 104                                 if ii.Flags&syscall.IFF_BROADCAST != 0 {
 105                                         flags |= FlagBroadcast
 106                                 }
 107                                 if ii.Flags&syscall.IFF_POINTTOPOINT != 0 {
 108                                         flags |= FlagPointToPoint
 109                                 }
 110                                 if ii.Flags&syscall.IFF_MULTICAST != 0 {
 111                                         flags |= FlagMulticast
 112                                 }
 113                         }
 114
 115                         name := bytePtrToString(&ai.AdapterName[0])
 116
 117                         ifi := Interface{
 118                                 Index:        int(index),
 119                                 MTU:          int(row.Mtu),
 120                                 Name:         name,
 121                                 HardwareAddr: HardwareAddr(row.PhysAddr[:row.PhysAddrLen]),
 122                                 Flags:        flags}
 123                         ift = append(ift, ifi)
 124                 }
 125         }
 126         return ift, nil
 127 }
 128
 129 // If the ifindex is zero, interfaceAddrTable returns addresses
 130 // for all network interfaces.  Otherwise it returns addresses
 131 // for a specific interface.
 132 func interfaceAddrTable(ifindex int) ([]Addr, error) {
 133         ai, err := getAdapterList()
 134         if err != nil {
 135                 return nil, err
 136         }
 137
 138         var ifat []Addr
 139         for ; ai != nil; ai = ai.Next {
 140                 index := ai.Index
 141                 if ifindex == 0 || ifindex == int(index) {
 142                         ipl := &ai.IpAddressList
 143                         for ; ipl != nil; ipl = ipl.Next {
 144                                 ifa := IPAddr{}
 145                                 ifa.IP = parseIPv4(bytePtrToString(&ipl.IpAddress.String[0]))
 146                                 ifat = append(ifat, ifa.toAddr())
 147                         }
 148                 }
 149         }
 150         return ifat, nil
 151 }
 152
 153 // If the ifindex is zero, interfaceMulticastAddrTable returns
 154 // addresses for all network interfaces.  Otherwise it returns
 155 // addresses for a specific interface.
 156 func interfaceMulticastAddrTable(ifindex int) ([]Addr, error) {
 157         return nil, nil
 158 }