public int GetPrefixLength()
{
byte[] byteBegin = Begin.GetAddressBytes();
// Handle single IP
if (Begin.Equals(End))
{
return(byteBegin.Length * 8);
}
int length = byteBegin.Length * 8;
for (int i = 0; i < length; i++)
{
byte[] mask = Bits.GetBitMask(byteBegin.Length, i);
if (new IPAddress(Bits.And(byteBegin, mask)).Equals(Begin))
{
if (new IPAddress(Bits.Or(byteBegin, Bits.Not(mask))).Equals(End))
{
return(i);
}
}
}
throw new FormatException(string.Format("{0} is not a CIDR Subnet", ToString()));
}
public void AndTest()
{
Bits.And(
new byte[] { 0xD6, 0x5E, 0xD6 },
new byte[] { 0x00, 0xFF, 0x72 })
.Is(new byte[] { 0x00, 0x5E, 0x52 });
}
/// <summary>
/// Determines whether an IP address is within the subnet.
/// </summary>
/// <param name="address">The IP address.</param>
/// <returns><c>true</c> if the address is within the subnet.</returns>
/// <exception cref="NotSupportedException">Thrown if for IPv6 addresses.</exception>
public bool Contains(IPAddress address)
{
if (address.AddressFamily != AddressFamily.InterNetwork)
{
throw new NotSupportedException("Only IPv4 addresses are supported.");
}
var maskBits = new Bits(Mask.GetAddressBytes());
var subnetBits = new Bits(Address.GetAddressBytes());
subnetBits = subnetBits.And(maskBits); // Zero any address bits to the right of the prefix
var addressBits = new Bits(address.GetAddressBytes());
addressBits = addressBits.And(maskBits); // Zero any address bits to the right of the prefix
for (int i = 0; i < addressBits.Length; i++)
{
if (addressBits[i] != subnetBits[i])
{
return(false);
}
}
return(true);
}
public void TestAndByte()
{
// fuzz testing
for (var i = 0; i < FuzzTestIterations; ++i)
{
var randomValue1 = this.GetRandomByte();
var randomValue2 = this.GetRandomByte();
Assert.AreEqual((byte)(randomValue1 & randomValue2), Bits.And(randomValue1, randomValue2));
}
}
/// <summary>
/// Creates a range from a base address and mask bits.
/// This can also be used with <see cref="SubnetMaskLength"/> to create a
/// range based on a subnet mask.
/// </summary>
/// <param name="baseAddress"></param>
/// <param name="maskLength"></param>
public IPAddressRange(IPAddress baseAddress, int maskLength)
{
if (baseAddress is null)
{
throw new ArgumentNullException(nameof(baseAddress));
}
var baseAdrBytes = baseAddress.GetAddressBytes();
if (baseAdrBytes.Length * 8 < maskLength)
{
throw new FormatException();
}
var maskBytes = Bits.GetBitMask(baseAdrBytes.Length, maskLength);
baseAdrBytes = Bits.And(baseAdrBytes, maskBytes);
Begin = new IPAddress(baseAdrBytes);
End = new IPAddress(Bits.Or(baseAdrBytes, Bits.Not(maskBytes)));
}
public static IPAddressRange Parse(string ipRangeString)
{
if (ipRangeString is null)
{
throw new ArgumentNullException(nameof(ipRangeString));
}
// trim white spaces.
ipRangeString = ipRangeString.Trim();
// define local funtion to strip scope id in ip address string.
string stripScopeId(string ipaddressString) => ipaddressString.Split('%')[0];
// Pattern 1. CIDR range: "192.168.0.0/24", "fe80::/10%eth0"
var m1 = m1_regex.Match(ipRangeString);
if (m1.Success)
{
var baseAdrBytes = IPAddress.Parse(stripScopeId(m1.Groups["adr"].Value)).GetAddressBytes();
var maskLen = int.Parse(m1.Groups["maskLen"].Value);
if (baseAdrBytes.Length * 8 < maskLen)
{
throw new FormatException();
}
var maskBytes = Bits.GetBitMask(baseAdrBytes.Length, maskLen);
baseAdrBytes = Bits.And(baseAdrBytes, maskBytes);
return(new IPAddressRange(new IPAddress(baseAdrBytes), new IPAddress(Bits.Or(baseAdrBytes, Bits.Not(maskBytes)))));
}
// Pattern 2. Uni address: "127.0.0.1", ":;1"
var m2 = m2_regex.Match(ipRangeString);
if (m2.Success)
{
return(new IPAddressRange(IPAddress.Parse(stripScopeId(ipRangeString))));
}
// Pattern 3. Begin end range: "169.258.0.0-169.258.0.255"
var m3 = m3_regex.Match(ipRangeString);
if (m3.Success)
{
// if the left part contains dot, but the right one does not, we treat it as a shortuct notation
// and simply copy the part before last dot from the left part as the prefix to the right one
var begin = m3.Groups["begin"].Value;
var end = m3.Groups["end"].Value;
if (begin.Contains('.') && !end.Contains('.'))
{
if (end.Contains('%'))
{
throw new FormatException("The end of IPv4 range shortcut notation contains scope id.");
}
var lastDotAt = begin.LastIndexOf('.');
end = begin.Substring(0, lastDotAt + 1) + end;
}
return(new IPAddressRange(
begin: IPAddress.Parse(stripScopeId(begin)),
end: IPAddress.Parse(stripScopeId(end))));
}
// Pattern 4. Bit mask range: "192.168.0.0/255.255.255.0"
var m4 = m4_regex.Match(ipRangeString);
if (m4.Success)
{
var baseAdrBytes = IPAddress.Parse(stripScopeId(m4.Groups["adr"].Value)).GetAddressBytes();
var maskBytes = IPAddress.Parse(m4.Groups["bitmask"].Value).GetAddressBytes();
baseAdrBytes = Bits.And(baseAdrBytes, maskBytes);
return(new IPAddressRange(new IPAddress(baseAdrBytes), new IPAddress(Bits.Or(baseAdrBytes, Bits.Not(maskBytes)))));
}
throw new FormatException("Unknown IP range string.");
}
/* */
public static Bits AND(Bits x, Bits y)
{
return(x.And(y));
}