interface_windows.go

Documentation: net

     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  package net
     6  
     7  import (
     8  	"internal/syscall/windows"
     9  	"os"
    10  	"syscall"
    11  	"unsafe"
    12  )
    13  
    14  // adapterAddresses returns a list of IP adapter and address
    15  // structures. The structure contains an IP adapter and flattened
    16  // multiple IP addresses including unicast, anycast and multicast
    17  // addresses.
    18  func adapterAddresses() ([]*windows.IpAdapterAddresses, error) {
    19  	var b []byte
    20  	l := uint32(15000) // recommended initial size
    21  	for {
    22  		b = make([]byte, l)
    23  		err := windows.GetAdaptersAddresses(syscall.AF_UNSPEC, windows.GAA_FLAG_INCLUDE_PREFIX, 0, (*windows.IpAdapterAddresses)(unsafe.Pointer(&b[0])), &l)
    24  		if err == nil {
    25  			if l == 0 {
    26  				return nil, nil
    27  			}
    28  			break
    29  		}
    30  		if err.(syscall.Errno) != syscall.ERROR_BUFFER_OVERFLOW {
    31  			return nil, os.NewSyscallError("getadaptersaddresses", err)
    32  		}
    33  		if l <= uint32(len(b)) {
    34  			return nil, os.NewSyscallError("getadaptersaddresses", err)
    35  		}
    36  	}
    37  	var aas []*windows.IpAdapterAddresses
    38  	for aa := (*windows.IpAdapterAddresses)(unsafe.Pointer(&b[0])); aa != nil; aa = aa.Next {
    39  		aas = append(aas, aa)
    40  	}
    41  	return aas, nil
    42  }
    43  
    44  // If the ifindex is zero, interfaceTable returns mappings of all
    45  // network interfaces. Otherwise it returns a mapping of a specific
    46  // interface.
    47  func interfaceTable(ifindex int) ([]Interface, error) {
    48  	aas, err := adapterAddresses()
    49  	if err != nil {
    50  		return nil, err
    51  	}
    52  	var ift []Interface
    53  	for _, aa := range aas {
    54  		index := aa.IfIndex
    55  		if index == 0 { // ipv6IfIndex is a substitute for ifIndex
    56  			index = aa.Ipv6IfIndex
    57  		}
    58  		if ifindex == 0 || ifindex == int(index) {
    59  			ifi := Interface{
    60  				Index: int(index),
    61  				Name:  windows.UTF16PtrToString(aa.FriendlyName),
    62  			}
    63  			if aa.OperStatus == windows.IfOperStatusUp {
    64  				ifi.Flags |= FlagUp
    65  				ifi.Flags |= FlagRunning
    66  			}
    67  			// For now we need to infer link-layer service
    68  			// capabilities from media types.
    69  			// TODO: use MIB_IF_ROW2.AccessType now that we no longer support
    70  			// Windows XP.
    71  			switch aa.IfType {
    72  			case windows.IF_TYPE_ETHERNET_CSMACD, windows.IF_TYPE_ISO88025_TOKENRING, windows.IF_TYPE_IEEE80211, windows.IF_TYPE_IEEE1394:
    73  				ifi.Flags |= FlagBroadcast | FlagMulticast
    74  			case windows.IF_TYPE_PPP, windows.IF_TYPE_TUNNEL:
    75  				ifi.Flags |= FlagPointToPoint | FlagMulticast
    76  			case windows.IF_TYPE_SOFTWARE_LOOPBACK:
    77  				ifi.Flags |= FlagLoopback | FlagMulticast
    78  			case windows.IF_TYPE_ATM:
    79  				ifi.Flags |= FlagBroadcast | FlagPointToPoint | FlagMulticast // assume all services available; LANE, point-to-point and point-to-multipoint
    80  			}
    81  			if aa.Mtu == 0xffffffff {
    82  				ifi.MTU = -1
    83  			} else {
    84  				ifi.MTU = int(aa.Mtu)
    85  			}
    86  			if aa.PhysicalAddressLength > 0 {
    87  				ifi.HardwareAddr = make(HardwareAddr, aa.PhysicalAddressLength)
    88  				copy(ifi.HardwareAddr, aa.PhysicalAddress[:])
    89  			}
    90  			ift = append(ift, ifi)
    91  			if ifindex == ifi.Index {
    92  				break
    93  			}
    94  		}
    95  	}
    96  	return ift, nil
    97  }
    98  
    99  // If the ifi is nil, interfaceAddrTable returns addresses for all
   100  // network interfaces. Otherwise it returns addresses for a specific
   101  // interface.
   102  func interfaceAddrTable(ifi *Interface) ([]Addr, error) {
   103  	aas, err := adapterAddresses()
   104  	if err != nil {
   105  		return nil, err
   106  	}
   107  	var ifat []Addr
   108  	for _, aa := range aas {
   109  		index := aa.IfIndex
   110  		if index == 0 { // ipv6IfIndex is a substitute for ifIndex
   111  			index = aa.Ipv6IfIndex
   112  		}
   113  		if ifi == nil || ifi.Index == int(index) {
   114  			for puni := aa.FirstUnicastAddress; puni != nil; puni = puni.Next {
   115  				sa, err := puni.Address.Sockaddr.Sockaddr()
   116  				if err != nil {
   117  					return nil, os.NewSyscallError("sockaddr", err)
   118  				}
   119  				switch sa := sa.(type) {
   120  				case *syscall.SockaddrInet4:
   121  					ifat = append(ifat, &IPNet{IP: IPv4(sa.Addr[0], sa.Addr[1], sa.Addr[2], sa.Addr[3]), Mask: CIDRMask(int(puni.OnLinkPrefixLength), 8*IPv4len)})
   122  				case *syscall.SockaddrInet6:
   123  					ifa := &IPNet{IP: make(IP, IPv6len), Mask: CIDRMask(int(puni.OnLinkPrefixLength), 8*IPv6len)}
   124  					copy(ifa.IP, sa.Addr[:])
   125  					ifat = append(ifat, ifa)
   126  				}
   127  			}
   128  			for pany := aa.FirstAnycastAddress; pany != nil; pany = pany.Next {
   129  				sa, err := pany.Address.Sockaddr.Sockaddr()
   130  				if err != nil {
   131  					return nil, os.NewSyscallError("sockaddr", err)
   132  				}
   133  				switch sa := sa.(type) {
   134  				case *syscall.SockaddrInet4:
   135  					ifat = append(ifat, &IPAddr{IP: IPv4(sa.Addr[0], sa.Addr[1], sa.Addr[2], sa.Addr[3])})
   136  				case *syscall.SockaddrInet6:
   137  					ifa := &IPAddr{IP: make(IP, IPv6len)}
   138  					copy(ifa.IP, sa.Addr[:])
   139  					ifat = append(ifat, ifa)
   140  				}
   141  			}
   142  		}
   143  	}
   144  	return ifat, nil
   145  }
   146  
   147  // interfaceMulticastAddrTable returns addresses for a specific
   148  // interface.
   149  func interfaceMulticastAddrTable(ifi *Interface) ([]Addr, error) {
   150  	aas, err := adapterAddresses()
   151  	if err != nil {
   152  		return nil, err
   153  	}
   154  	var ifat []Addr
   155  	for _, aa := range aas {
   156  		index := aa.IfIndex
   157  		if index == 0 { // ipv6IfIndex is a substitute for ifIndex
   158  			index = aa.Ipv6IfIndex
   159  		}
   160  		if ifi == nil || ifi.Index == int(index) {
   161  			for pmul := aa.FirstMulticastAddress; pmul != nil; pmul = pmul.Next {
   162  				sa, err := pmul.Address.Sockaddr.Sockaddr()
   163  				if err != nil {
   164  					return nil, os.NewSyscallError("sockaddr", err)
   165  				}
   166  				switch sa := sa.(type) {
   167  				case *syscall.SockaddrInet4:
   168  					ifat = append(ifat, &IPAddr{IP: IPv4(sa.Addr[0], sa.Addr[1], sa.Addr[2], sa.Addr[3])})
   169  				case *syscall.SockaddrInet6:
   170  					ifa := &IPAddr{IP: make(IP, IPv6len)}
   171  					copy(ifa.IP, sa.Addr[:])
   172  					ifat = append(ifat, ifa)
   173  				}
   174  			}
   175  		}
   176  	}
   177  	return ifat, nil
   178  }
   179
View as plain text