Poiché il codice del blog MSDN si basa su una trasmissione e IPv6 non ne ha uno, non so se funzioni con IPv6.
ho finito con questi metodi (grazie a nu everest). È possibile ottenere la sottorete e la maschera da una notazione CIDR ("1.2.3.4/5") e verificare se un indirizzo si trova all'interno di questa rete oppure no.
Questo funziona per IPv4 e IPv6: l'utilizzo
public static class IpAddresses
{
public static Tuple<IPAddress, IPAddress> GetSubnetAndMaskFromCidr(string cidr)
{
var delimiterIndex = cidr.IndexOf('/');
string ipSubnet = cidr.Substring(0, delimiterIndex);
string mask = cidr.Substring(delimiterIndex + 1);
var subnetAddress = IPAddress.Parse(ipSubnet);
if (subnetAddress.AddressFamily == AddressFamily.InterNetworkV6)
{
// ipv6
var ip = BigInteger.Parse("00FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF", NumberStyles.HexNumber) << (128 - int.Parse(mask));
var maskBytes = new[]
{
(byte)((ip & BigInteger.Parse("00FF000000000000000000000000000000", NumberStyles.HexNumber)) >> 120),
(byte)((ip & BigInteger.Parse("0000FF0000000000000000000000000000", NumberStyles.HexNumber)) >> 112),
(byte)((ip & BigInteger.Parse("000000FF00000000000000000000000000", NumberStyles.HexNumber)) >> 104),
(byte)((ip & BigInteger.Parse("00000000FF000000000000000000000000", NumberStyles.HexNumber)) >> 96),
(byte)((ip & BigInteger.Parse("0000000000FF0000000000000000000000", NumberStyles.HexNumber)) >> 88),
(byte)((ip & BigInteger.Parse("000000000000FF00000000000000000000", NumberStyles.HexNumber)) >> 80),
(byte)((ip & BigInteger.Parse("00000000000000FF000000000000000000", NumberStyles.HexNumber)) >> 72),
(byte)((ip & BigInteger.Parse("0000000000000000FF0000000000000000", NumberStyles.HexNumber)) >> 64),
(byte)((ip & BigInteger.Parse("000000000000000000FF00000000000000", NumberStyles.HexNumber)) >> 56),
(byte)((ip & BigInteger.Parse("00000000000000000000FF000000000000", NumberStyles.HexNumber)) >> 48),
(byte)((ip & BigInteger.Parse("0000000000000000000000FF0000000000", NumberStyles.HexNumber)) >> 40),
(byte)((ip & BigInteger.Parse("000000000000000000000000FF00000000", NumberStyles.HexNumber)) >> 32),
(byte)((ip & BigInteger.Parse("00000000000000000000000000FF000000", NumberStyles.HexNumber)) >> 24),
(byte)((ip & BigInteger.Parse("0000000000000000000000000000FF0000", NumberStyles.HexNumber)) >> 16),
(byte)((ip & BigInteger.Parse("000000000000000000000000000000FF00", NumberStyles.HexNumber)) >> 8),
(byte)((ip & BigInteger.Parse("00000000000000000000000000000000FF", NumberStyles.HexNumber)) >> 0),
};
return Tuple.Create(subnetAddress, new IPAddress(maskBytes));
}
else
{
// ipv4
uint ip = 0xFFFFFFFF << (32 - int.Parse(mask));
var maskBytes = new[]
{
(byte)((ip & 0xFF000000) >> 24),
(byte)((ip & 0x00FF0000) >> 16),
(byte)((ip & 0x0000FF00) >> 8),
(byte)((ip & 0x000000FF) >> 0),
};
return Tuple.Create(subnetAddress, new IPAddress(maskBytes));
}
}
public static bool IsAddressOnSubnet(IPAddress address, IPAddress subnet, IPAddress mask)
{
byte[] addressOctets = address.GetAddressBytes();
byte[] subnetOctets = mask.GetAddressBytes();
byte[] networkOctets = subnet.GetAddressBytes();
// ensure that IPv4 isn't mixed with IPv6
if (addressOctets.Length != subnetOctets.Length
|| addressOctets.Length != networkOctets.Length)
{
return false;
}
for (int i = 0; i < addressOctets.Length; i += 1)
{
var addressOctet = addressOctets[i];
var subnetOctet = subnetOctets[i];
var networkOctet = networkOctets[i];
if (networkOctet != (addressOctet & subnetOctet))
{
return false;
}
}
return true;
}
}
Esempio:
var subnetAndMask = IpAddresses.GetSubnetAndMaskFromCidr("10.132.0.0/20");
bool result = IpAddresses.IsAddressOnSubnet(
IPAddress.Parse("10.132.12.34"),
subnetAndMask.Item1,
subnetAndMask.Item2);
Che dire degli indirizzi IPv6? – ageroh
@ageroh GitHub sembra avere alcune librerie C# in grado di gestire gli indirizzi IPv6. IPNetwork, ad esempio https://github.com/lduchosal/ipnetwork –