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  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  			}
    66  			// For now we need to infer link-layer service
    67  			// capabilities from media types.
    68  			// TODO: use MIB_IF_ROW2.AccessType now that we no longer support
    69  			// Windows XP.
    70  			switch aa.IfType {
    71  			case windows.IF_TYPE_ETHERNET_CSMACD, windows.IF_TYPE_ISO88025_TOKENRING, windows.IF_TYPE_IEEE80211, windows.IF_TYPE_IEEE1394:
    72  				ifi.Flags |= FlagBroadcast | FlagMulticast
    73  			case windows.IF_TYPE_PPP, windows.IF_TYPE_TUNNEL:
    74  				ifi.Flags |= FlagPointToPoint | FlagMulticast
    75  			case windows.IF_TYPE_SOFTWARE_LOOPBACK:
    76  				ifi.Flags |= FlagLoopback | FlagMulticast
    77  			case windows.IF_TYPE_ATM:
    78  				ifi.Flags |= FlagBroadcast | FlagPointToPoint | FlagMulticast // assume all services available; LANE, point-to-point and point-to-multipoint
    79  			}
    80  			if aa.Mtu == 0xffffffff {
    81  				ifi.MTU = -1
    82  			} else {
    83  				ifi.MTU = int(aa.Mtu)
    84  			}
    85  			if aa.PhysicalAddressLength > 0 {
    86  				ifi.HardwareAddr = make(HardwareAddr, aa.PhysicalAddressLength)
    87  				copy(ifi.HardwareAddr, aa.PhysicalAddress[:])
    88  			}
    89  			ift = append(ift, ifi)
    90  			if ifindex == ifi.Index {
    91  				break
    92  			}
    93  		}
    94  	}
    95  	return ift, nil
    96  }
    97  
    98  // If the ifi is nil, interfaceAddrTable returns addresses for all
    99  // network interfaces. Otherwise it returns addresses for a specific
   100  // interface.
   101  func interfaceAddrTable(ifi *Interface) ([]Addr, error) {
   102  	aas, err := adapterAddresses()
   103  	if err != nil {
   104  		return nil, err
   105  	}
   106  	var ifat []Addr
   107  	for _, aa := range aas {
   108  		index := aa.IfIndex
   109  		if index == 0 { // ipv6IfIndex is a substitute for ifIndex
   110  			index = aa.Ipv6IfIndex
   111  		}
   112  		if ifi == nil || ifi.Index == int(index) {
   113  			for puni := aa.FirstUnicastAddress; puni != nil; puni = puni.Next {
   114  				sa, err := puni.Address.Sockaddr.Sockaddr()
   115  				if err != nil {
   116  					return nil, os.NewSyscallError("sockaddr", err)
   117  				}
   118  				switch sa := sa.(type) {
   119  				case *syscall.SockaddrInet4:
   120  					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)})
   121  				case *syscall.SockaddrInet6:
   122  					ifa := &IPNet{IP: make(IP, IPv6len), Mask: CIDRMask(int(puni.OnLinkPrefixLength), 8*IPv6len)}
   123  					copy(ifa.IP, sa.Addr[:])
   124  					ifat = append(ifat, ifa)
   125  				}
   126  			}
   127  			for pany := aa.FirstAnycastAddress; pany != nil; pany = pany.Next {
   128  				sa, err := pany.Address.Sockaddr.Sockaddr()
   129  				if err != nil {
   130  					return nil, os.NewSyscallError("sockaddr", err)
   131  				}
   132  				switch sa := sa.(type) {
   133  				case *syscall.SockaddrInet4:
   134  					ifat = append(ifat, &IPAddr{IP: IPv4(sa.Addr[0], sa.Addr[1], sa.Addr[2], sa.Addr[3])})
   135  				case *syscall.SockaddrInet6:
   136  					ifa := &IPAddr{IP: make(IP, IPv6len)}
   137  					copy(ifa.IP, sa.Addr[:])
   138  					ifat = append(ifat, ifa)
   139  				}
   140  			}
   141  		}
   142  	}
   143  	return ifat, nil
   144  }
   145  
   146  // interfaceMulticastAddrTable returns addresses for a specific
   147  // interface.
   148  func interfaceMulticastAddrTable(ifi *Interface) ([]Addr, error) {
   149  	aas, err := adapterAddresses()
   150  	if err != nil {
   151  		return nil, err
   152  	}
   153  	var ifat []Addr
   154  	for _, aa := range aas {
   155  		index := aa.IfIndex
   156  		if index == 0 { // ipv6IfIndex is a substitute for ifIndex
   157  			index = aa.Ipv6IfIndex
   158  		}
   159  		if ifi == nil || ifi.Index == int(index) {
   160  			for pmul := aa.FirstMulticastAddress; pmul != nil; pmul = pmul.Next {
   161  				sa, err := pmul.Address.Sockaddr.Sockaddr()
   162  				if err != nil {
   163  					return nil, os.NewSyscallError("sockaddr", err)
   164  				}
   165  				switch sa := sa.(type) {
   166  				case *syscall.SockaddrInet4:
   167  					ifat = append(ifat, &IPAddr{IP: IPv4(sa.Addr[0], sa.Addr[1], sa.Addr[2], sa.Addr[3])})
   168  				case *syscall.SockaddrInet6:
   169  					ifa := &IPAddr{IP: make(IP, IPv6len)}
   170  					copy(ifa.IP, sa.Addr[:])
   171  					ifat = append(ifat, ifa)
   172  				}
   173  			}
   174  		}
   175  	}
   176  	return ifat, nil
   177  }
   178
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