IP addresses print CIDR of /? if it is not a real CIDR approved subnet mask. For example, a subnet mask of .250 gives a /?, but .252 gives /30. While this is not real-life (real life does not tell us when we use a foolish subnet), it helps considerably when testing things.

This commit is contained in:
Tim Young 2017-06-27 15:37:33 -05:00
parent a1a7d10a56
commit 9c764c4f90
2 changed files with 45 additions and 15 deletions

View File

@ -6,7 +6,7 @@ using System.Threading.Tasks;
using System.Globalization;
using System.Xml;
using System.Windows.Forms;
using System.Text.RegularExpressions;
namespace EduNetworkBuilder
{
@ -141,18 +141,23 @@ namespace EduNetworkBuilder
}
else
{
UInt32 tInt = 0;
int cdr;
int.TryParse(mySplitVal[1], out cdr);
for (int loop = 0; loop < 32; loop++)
{
tInt = (tInt << 1);
if (loop < cdr) tInt++;
}
_mask = tInt;
_mask = MaskNumFromCIDRString(mySplitVal[1]);
}
}
static UInt32 MaskNumFromCIDRString(string cidr)
{
UInt32 tInt = 0;
int cdr;
int.TryParse(cidr, out cdr);
for (int loop = 0; loop < 32; loop++)
{
tInt = (tInt << 1);
if (loop < cdr) tInt++;
}
return tInt;
}
public bool Equals(UInt32 IP)
{
@ -228,6 +233,31 @@ namespace EduNetworkBuilder
PadIt(_ip.ToIpString()), PadIt(_mask.ToIpString()), PadIt(gw));
return tstring;
}
/// <summary>
/// Return the CIDR number for this address. This is the number of 1s before the first 0
/// </summary>
/// <returns></returns>
public int CIDRNumber()
{
string mask = GetMask.ToBitString();
mask = Regex.Replace(mask, "0", "");
return mask.Length;
}
/// <summary>
/// Return true if the subnet mask is really a true CIDR string /8, /16, etc.
/// It is false if the subnet mask creates a mask that does not map to CIDR. For
/// example, 255.255.255.250 is not a real subnet mask. 252 is.
/// </summary>
/// <returns>True if there are no 1s after the first 0</returns>
public bool ValidCIDR()
{
int cidr = CIDRNumber();
UInt32 tMask = MaskNumFromCIDRString(cidr.ToString());
if (tMask == _mask) return true;
return false;
}
}
public static class IpHelpers

View File

@ -151,10 +151,10 @@ namespace EduNetworkBuilder
}
else
{
string mask = myIP.GetMask.ToBitString();
mask = Regex.Replace(mask, "0", "");
int count = mask.Length;
tstring += "/" + count.ToString();
int cidr = myIP.CIDRNumber();
string answer = cidr.ToString();
if (!myIP.ValidCIDR()) answer = "?";
tstring += "/" + answer;
}
return tstring;
}