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// Copyright 2011 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package net
import (
"internal/syscall/windows"
"os"
"syscall"
"unsafe"
)
// supportsVistaIP reports whether the platform implements new IP
// stack and ABIs supported on Windows Vista and above.
var supportsVistaIP bool
func init() {
supportsVistaIP = probeWindowsIPStack()
}
func probeWindowsIPStack() (supportsVistaIP bool) {
v, err := syscall.GetVersion()
if err != nil {
return true // Windows 10 and above will deprecate this API
}
return byte(v) >= 6 // major version of Windows Vista is 6
}
// adapterAddresses returns a list of IP adapter and address
// structures. The structure contains an IP adapter and flattened
// multiple IP addresses including unicast, anycast and multicast
// addresses.
func adapterAddresses() ([]*windows.IpAdapterAddresses, error) {
var b []byte
l := uint32(15000) // recommended initial size
for {
b = make([]byte, l)
err := windows.GetAdaptersAddresses(syscall.AF_UNSPEC, windows.GAA_FLAG_INCLUDE_PREFIX, 0, (*windows.IpAdapterAddresses)(unsafe.Pointer(&b[0])), &l)
if err == nil {
if l == 0 {
return nil, nil
}
break
}
if err.(syscall.Errno) != syscall.ERROR_BUFFER_OVERFLOW {
return nil, os.NewSyscallError("getadaptersaddresses", err)
}
if l <= uint32(len(b)) {
return nil, os.NewSyscallError("getadaptersaddresses", err)
}
}
var aas []*windows.IpAdapterAddresses
for aa := (*windows.IpAdapterAddresses)(unsafe.Pointer(&b[0])); aa != nil; aa = aa.Next {
aas = append(aas, aa)
}
return aas, nil
}
// If the ifindex is zero, interfaceTable returns mappings of all
// network interfaces. Otherwise it returns a mapping of a specific
// interface.
func interfaceTable(ifindex int) ([]Interface, error) {
aas, err := adapterAddresses()
if err != nil {
return nil, err
}
var ift []Interface
for _, aa := range aas {
index := aa.IfIndex
if index == 0 { // ipv6IfIndex is a substitute for ifIndex
index = aa.Ipv6IfIndex
}
if ifindex == 0 || ifindex == int(index) {
ifi := Interface{
Index: int(index),
Name: syscall.UTF16ToString((*(*[10000]uint16)(unsafe.Pointer(aa.FriendlyName)))[:]),
}
if aa.OperStatus == windows.IfOperStatusUp {
ifi.Flags |= FlagUp
}
// For now we need to infer link-layer service
// capabilities from media types.
// We will be able to use
// MIB_IF_ROW2.AccessType once we drop support
// for Windows XP.
switch aa.IfType {
case windows.IF_TYPE_ETHERNET_CSMACD, windows.IF_TYPE_ISO88025_TOKENRING, windows.IF_TYPE_IEEE80211, windows.IF_TYPE_IEEE1394:
ifi.Flags |= FlagBroadcast | FlagMulticast
case windows.IF_TYPE_PPP, windows.IF_TYPE_TUNNEL:
ifi.Flags |= FlagPointToPoint | FlagMulticast
case windows.IF_TYPE_SOFTWARE_LOOPBACK:
ifi.Flags |= FlagLoopback | FlagMulticast
case windows.IF_TYPE_ATM:
ifi.Flags |= FlagBroadcast | FlagPointToPoint | FlagMulticast // assume all services available; LANE, point-to-point and point-to-multipoint
}
if aa.Mtu == 0xffffffff {
ifi.MTU = -1
} else {
ifi.MTU = int(aa.Mtu)
}
if aa.PhysicalAddressLength > 0 {
ifi.HardwareAddr = make(HardwareAddr, aa.PhysicalAddressLength)
copy(ifi.HardwareAddr, aa.PhysicalAddress[:])
}
ift = append(ift, ifi)
if ifindex == ifi.Index {
break
}
}
}
return ift, nil
}
// If the ifi is nil, interfaceAddrTable returns addresses for all
// network interfaces. Otherwise it returns addresses for a specific
// interface.
func interfaceAddrTable(ifi *Interface) ([]Addr, error) {
aas, err := adapterAddresses()
if err != nil {
return nil, err
}
var ifat []Addr
for _, aa := range aas {
index := aa.IfIndex
if index == 0 { // ipv6IfIndex is a substitute for ifIndex
index = aa.Ipv6IfIndex
}
var pfx4, pfx6 []IPNet
if !supportsVistaIP {
pfx4, pfx6, err = addrPrefixTable(aa)
if err != nil {
return nil, err
}
}
if ifi == nil || ifi.Index == int(index) {
for puni := aa.FirstUnicastAddress; puni != nil; puni = puni.Next {
sa, err := puni.Address.Sockaddr.Sockaddr()
if err != nil {
return nil, os.NewSyscallError("sockaddr", err)
}
var l int
switch sa := sa.(type) {
case *syscall.SockaddrInet4:
if supportsVistaIP {
l = int(puni.OnLinkPrefixLength)
} else {
l = addrPrefixLen(pfx4, IP(sa.Addr[:]))
}
ifat = append(ifat, &IPNet{IP: IPv4(sa.Addr[0], sa.Addr[1], sa.Addr[2], sa.Addr[3]), Mask: CIDRMask(l, 8*IPv4len)})
case *syscall.SockaddrInet6:
if supportsVistaIP {
l = int(puni.OnLinkPrefixLength)
} else {
l = addrPrefixLen(pfx6, IP(sa.Addr[:]))
}
ifa := &IPNet{IP: make(IP, IPv6len), Mask: CIDRMask(l, 8*IPv6len)}
copy(ifa.IP, sa.Addr[:])
ifat = append(ifat, ifa)
}
}
for pany := aa.FirstAnycastAddress; pany != nil; pany = pany.Next {
sa, err := pany.Address.Sockaddr.Sockaddr()
if err != nil {
return nil, os.NewSyscallError("sockaddr", err)
}
switch sa := sa.(type) {
case *syscall.SockaddrInet4:
ifat = append(ifat, &IPAddr{IP: IPv4(sa.Addr[0], sa.Addr[1], sa.Addr[2], sa.Addr[3])})
case *syscall.SockaddrInet6:
ifa := &IPAddr{IP: make(IP, IPv6len)}
copy(ifa.IP, sa.Addr[:])
ifat = append(ifat, ifa)
}
}
}
}
return ifat, nil
}
func addrPrefixTable(aa *windows.IpAdapterAddresses) (pfx4, pfx6 []IPNet, err error) {
for p := aa.FirstPrefix; p != nil; p = p.Next {
sa, err := p.Address.Sockaddr.Sockaddr()
if err != nil {
return nil, nil, os.NewSyscallError("sockaddr", err)
}
switch sa := sa.(type) {
case *syscall.SockaddrInet4:
pfx := IPNet{IP: IP(sa.Addr[:]), Mask: CIDRMask(int(p.PrefixLength), 8*IPv4len)}
pfx4 = append(pfx4, pfx)
case *syscall.SockaddrInet6:
pfx := IPNet{IP: IP(sa.Addr[:]), Mask: CIDRMask(int(p.PrefixLength), 8*IPv6len)}
pfx6 = append(pfx6, pfx)
}
}
return
}
// addrPrefixLen returns an appropriate prefix length in bits for ip
// from pfxs. It returns 32 or 128 when no appropriate on-link address
// prefix found.
//
// NOTE: This is pretty naive implementation that contains many
// allocations and non-effective linear search, and should not be used
// freely.
func addrPrefixLen(pfxs []IPNet, ip IP) int {
var l int
var cand *IPNet
for i := range pfxs {
if !pfxs[i].Contains(ip) {
continue
}
if cand == nil {
l, _ = pfxs[i].Mask.Size()
cand = &pfxs[i]
continue
}
m, _ := pfxs[i].Mask.Size()
if m > l {
l = m
cand = &pfxs[i]
continue
}
}
if l > 0 {
return l
}
if ip.To4() != nil {
return 8 * IPv4len
}
return 8 * IPv6len
}
// interfaceMulticastAddrTable returns addresses for a specific
// interface.
func interfaceMulticastAddrTable(ifi *Interface) ([]Addr, error) {
aas, err := adapterAddresses()
if err != nil {
return nil, err
}
var ifat []Addr
for _, aa := range aas {
index := aa.IfIndex
if index == 0 { // ipv6IfIndex is a substitute for ifIndex
index = aa.Ipv6IfIndex
}
if ifi == nil || ifi.Index == int(index) {
for pmul := aa.FirstMulticastAddress; pmul != nil; pmul = pmul.Next {
sa, err := pmul.Address.Sockaddr.Sockaddr()
if err != nil {
return nil, os.NewSyscallError("sockaddr", err)
}
switch sa := sa.(type) {
case *syscall.SockaddrInet4:
ifat = append(ifat, &IPAddr{IP: IPv4(sa.Addr[0], sa.Addr[1], sa.Addr[2], sa.Addr[3])})
case *syscall.SockaddrInet6:
ifa := &IPAddr{IP: make(IP, IPv6len)}
copy(ifa.IP, sa.Addr[:])
ifat = append(ifat, ifa)
}
}
}
}
return ifat, nil
}