/// <summary>
/// Attempts to parse a subnet from CIDR notation in the form of <i>ip-address</i>/<i>prefix</i>,
/// where <i>prefix</i> is the network prefix length in bits.
/// </summary>
/// <param name="input">The input string.</param>
/// <param name="cidr">The parsed <see cref="NetworkCidr"/>.</param>
/// <returns><c>true</c> if the operation was successful.</returns>
public static bool TryParse(string input, out NetworkCidr cidr)
{
cidr = null;
if (string.IsNullOrEmpty(input))
{
return(false);
}
var slashPos = input.IndexOf('/');
if (slashPos <= 0)
{
return(false);
}
if (!IPAddress.TryParse(input.Substring(0, slashPos), out var address))
{
return(false);
}
if (!int.TryParse(input.Substring(slashPos + 1), out var prefixLength) || prefixLength < 0 || prefixLength > 32)
{
return(false);
}
cidr = new NetworkCidr();
cidr.Initialize(address, prefixLength);
return(true);
}
/// <summary>
/// Parses a subnet from CIDR notation in the form of <i>ip-address</i>/<i>prefix</i>,
/// where <i>prefix</i> is the network prefix length in bits.
/// </summary>
/// <param name="input">The input string.</param>
/// <returns>The parsed <see cref="NetworkCidr"/>.</returns>
/// <exception cref="ArgumentException">Thrown if the input is not correctly formatted.</exception>
public static NetworkCidr Parse(string input)
{
Covenant.Requires <ArgumentNullException>(!string.IsNullOrEmpty(input));
var slashPos = input.IndexOf('/');
if (slashPos <= 0)
{
throw new ArgumentException($"Invalid CIDR [{input}].");
}
if (!IPAddress.TryParse(input.Substring(0, slashPos), out var address))
{
throw new ArgumentException($"Invalid CIDR [{input}].");
}
if (!int.TryParse(input.Substring(slashPos + 1), out var prefixLength) || prefixLength < 0 || prefixLength > 32)
{
throw new ArgumentException($"Invalid CIDR [{input}].");
}
var cidr = new NetworkCidr();
cidr.Initialize(address, prefixLength);
return(cidr);
}
/// <summary>
/// Determines whether this subnet overlaps another.
/// </summary>
/// <param name="subnet">The subnet being tested.</param>
/// <returns><c>true</c> if the subnets overlap.</returns>
/// <exception cref="ArgumentNullException">Thrown if <paramref name="subnet"/> is <c>null</c>.</exception>
public bool Overlaps(NetworkCidr subnet)
{
Covenant.Requires <ArgumentNullException>(subnet != null);
var first = NetHelper.AddressToUint(this.FirstAddress);
var last = NetHelper.AddressToUint(this.LastAddress);
var subnetFirst = NetHelper.AddressToUint(subnet.FirstAddress);
var subnetLast = NetHelper.AddressToUint(subnet.LastAddress);
if (last < subnetFirst)
{
return(false);
}
else if (first > subnetLast)
{
return(false);
}
else
{
return(true);
}
}
/// <summary>
/// Determines whether a subnet is completely contained within the current subnet.
/// </summary>
/// <param name="subnet">The subnet being tested.</param>
/// <returns><c>true</c> if <paramref name="subnet"/> is fully contained.</returns>
public bool Contains(NetworkCidr subnet)
{
Covenant.Requires <ArgumentNullException>(subnet != null);
return(Contains(subnet.FirstAddress) && Contains(subnet.LastAddress));
}
