How do I iterate through a range of IP addresses provided by the user?
I'm flexible on the format, provided it allows all ranges to be specified. Perhaps something like the nmap-style:
'192.0.2.1' # one IP address
'192.0.2.0-31' # one block with 32 IP addresses.
'192.0.2-3.1-254' # two blocks with 254 IP addresses.
'0-255.0-255.0-255.0-255' # the whole IPv4 address space
For example, if the user entered 192.0.2-3.1-254
, I would like to know how to generate a list of all the valid IP addresses in this range so that I could iterate through them.
For example:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Net;
using System.Text.RegularExpressions;
namespace IpRanges
{
public class IPRange
{
public IPRange(string ipRange)
{
if (ipRange == null)
throw new ArgumentNullException();
if (!TryParseCIDRNotation(ipRange) && !TryParseSimpleRange(ipRange))
throw new ArgumentException();
}
public IEnumerable<IPAddress> GetAllIP()
{
int capacity = 1;
for (int i = 0; i < 4; i++)
capacity *= endIP[i] - beginIP[i] + 1;
List<IPAddress> ips = new List<IPAddress>(capacity);
for (int i0 = beginIP[0]; i0 <= endIP[0]; i0++)
{
for (int i1 = beginIP[1]; i1 <= endIP[1]; i1++)
{
for (int i2 = beginIP[2]; i2 <= endIP[2]; i2++)
{
for (int i3 = beginIP[3]; i3 <= endIP[3]; i3++)
{
ips.Add(new IPAddress(new byte[] { (byte)i0, (byte)i1, (byte)i2, (byte)i3 }));
}
}
}
}
return ips;
}
/// <summary>
/// Parse IP-range string in CIDR notation.
/// For example "12.15.0.0/16".
/// </summary>
/// <param name="ipRange"></param>
/// <returns></returns>
private bool TryParseCIDRNotation(string ipRange)
{
string[] x = ipRange.Split('/');
if (x.Length != 2)
return false;
byte bits = byte.Parse(x[1]);
uint ip = 0;
String[] ipParts0 = x[0].Split('.');
for (int i = 0; i < 4; i++)
{
ip = ip << 8;
ip += uint.Parse(ipParts0[i]);
}
byte shiftBits = (byte)(32 - bits);
uint ip1 = (ip >> shiftBits) << shiftBits;
if (ip1 != ip) // Check correct subnet address
return false;
uint ip2 = ip1 >> shiftBits;
for (int k = 0; k < shiftBits; k++)
{
ip2 = (ip2 << 1) + 1;
}
beginIP = new byte[4];
endIP = new byte[4];
for (int i = 0; i < 4; i++)
{
beginIP[i] = (byte) ((ip1 >> (3 - i) * 8) & 255);
endIP[i] = (byte)((ip2 >> (3 - i) * 8) & 255);
}
return true;
}
/// <summary>
/// Parse IP-range string "12.15-16.1-30.10-255"
/// </summary>
/// <param name="ipRange"></param>
/// <returns></returns>
private bool TryParseSimpleRange(string ipRange)
{
String[] ipParts = ipRange.Split('.');
beginIP = new byte[4];
endIP = new byte[4];
for (int i = 0; i < 4; i++)
{
string[] rangeParts = ipParts[i].Split('-');
if (rangeParts.Length < 1 || rangeParts.Length > 2)
return false;
beginIP[i] = byte.Parse(rangeParts[0]);
endIP[i] = (rangeParts.Length == 1) ? beginIP[i] : byte.Parse(rangeParts[1]);
}
return true;
}
private byte [] beginIP;
private byte [] endIP;
}
}
Check out the snippet here. Keep the credits in place if you use this please.
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Net;
/* ====================================================================================
C# IP address range finder helper class (C) Nahum Bazes
* Free for private & commercial use - no restriction applied, please leave credits.
* DO NOT REMOVE THIS COMMENT
* ==================================================================================== */
namespace IPAddressTools
{
public class RangeFinder
{
public IEnumerable<string> GetIPRange(IPAddress startIP,
IPAddress endIP)
{
uint sIP = ipToUint(startIP.GetAddressBytes());
uint eIP = ipToUint(endIP.GetAddressBytes());
while (sIP <= eIP)
{
yield return new IPAddress(reverseBytesArray(sIP)).ToString();
sIP++;
}
}
/* reverse byte order in array */
protected uint reverseBytesArray(uint ip)
{
byte[] bytes = BitConverter.GetBytes(ip);
bytes = bytes.Reverse().ToArray();
return (uint)BitConverter.ToInt32(bytes, 0);
}
/* Convert bytes array to 32 bit long value */
protected uint ipToUint(byte[] ipBytes)
{
ByteConverter bConvert = new ByteConverter();
uint ipUint = 0;
int shift = 24; // indicates number of bits left for shifting
foreach (byte b in ipBytes)
{
if (ipUint == 0)
{
ipUint = (uint)bConvert.ConvertTo(b, typeof(uint)) << shift;
shift -= 8;
continue;
}
if (shift >= 8)
ipUint += (uint)bConvert.ConvertTo(b, typeof(uint)) << shift;
else
ipUint += (uint)bConvert.ConvertTo(b, typeof(uint));
shift -= 8;
}
return ipUint;
}
}
}
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