// 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
}
func getAdapters() (*windows.IpAdapterAddresses, error) {
block := uint32(unsafe.Sizeof(windows.IpAdapterAddresses{}))
// pre-allocate a 15KB working buffer pointed to by the AdapterAddresses
// parameter.
// https://msdn.microsoft.com/en-us/library/windows/desktop/aa365915(v=vs.85).aspx
size := uint32(15000)
var addrs []windows.IpAdapterAddresses
for {
addrs = make([]windows.IpAdapterAddresses, size/block+1)
err := windows.GetAdaptersAddresses(syscall.AF_UNSPEC, windows.GAA_FLAG_INCLUDE_PREFIX, 0, &addrs[0], &size)
if err == nil {
break
}
if err.(syscall.Errno) != syscall.ERROR_BUFFER_OVERFLOW {
return nil, os.NewSyscallError("GetAdaptersAddresses", err)
}
}
return &addrs[0], nil
}