libgo/go/net/interface_darwin.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 Darwin
   6
   7 package net
   8
   9 import (
  10         "os"
  11         "syscall"
  12 )
  13
  14 // If the ifindex is zero, interfaceMulticastAddrTable returns
  15 // addresses for all network interfaces.  Otherwise it returns
  16 // addresses for a specific interface.
  17 func interfaceMulticastAddrTable(ifindex int) ([]Addr, error) {
  18         tab, err := syscall.RouteRIB(syscall.NET_RT_IFLIST2, ifindex)
  19         if err != nil {
  20                 return nil, os.NewSyscallError("route rib", err)
  21         }
  22
  23         msgs, err := syscall.ParseRoutingMessage(tab)
  24         if err != nil {
  25                 return nil, os.NewSyscallError("route message", err)
  26         }
  27
  28         var ifmat []Addr
  29         for _, m := range msgs {
  30                 switch v := m.(type) {
  31                 case *syscall.InterfaceMulticastAddrMessage:
  32                         if ifindex == 0 || ifindex == int(v.Header.Index) {
  33                                 ifma, err := newMulticastAddr(v)
  34                                 if err != nil {
  35                                         return nil, err
  36                                 }
  37                                 ifmat = append(ifmat, ifma...)
  38                         }
  39                 }
  40         }
  41         return ifmat, nil
  42 }
  43
  44 func newMulticastAddr(m *syscall.InterfaceMulticastAddrMessage) ([]Addr, error) {
  45         sas, err := syscall.ParseRoutingSockaddr(m)
  46         if err != nil {
  47                 return nil, os.NewSyscallError("route sockaddr", err)
  48         }
  49
  50         var ifmat []Addr
  51         for _, s := range sas {
  52                 switch v := s.(type) {
  53                 case *syscall.SockaddrInet4:
  54                         ifma := &IPAddr{IP: IPv4(v.Addr[0], v.Addr[1], v.Addr[2], v.Addr[3])}
  55                         ifmat = append(ifmat, ifma.toAddr())
  56                 case *syscall.SockaddrInet6:
  57                         ifma := &IPAddr{IP: make(IP, IPv6len)}
  58                         copy(ifma.IP, v.Addr[:])
  59                         // NOTE: KAME based IPv6 protcol stack usually embeds
  60                         // the interface index in the interface-local or link-
  61                         // local address as the kernel-internal form.
  62                         if ifma.IP.IsInterfaceLocalMulticast() ||
  63                                 ifma.IP.IsLinkLocalMulticast() {
  64                                 // remove embedded scope zone ID
  65                                 ifma.IP[2], ifma.IP[3] = 0, 0
  66                         }
  67                         ifmat = append(ifmat, ifma.toAddr())
  68                 }
  69         }
  70         return ifmat, nil
  71 }