C#: Enumerate IP addresses in a range

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'       开发者_运维问答          #   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;
        }
    }
}

I'm late to the game, but your question was mentioned in duplicate, so I just add the answer here. Using the IPAddressRange library, you can enumerate your IPs like that:

var start = IPAddress.Parse("192.168.0.2");
var end = IPAddress.Parse("192.168.0.254");

var range = new IPAddressRange(start, end);

foreach (var ip in range)
{
    Console.WriteLine(ip);
}

The library also supports CIDR notation and range strings

I think this should do it.

static void TestFunc()
{
    byte[,] range = ParseRange("192.0.2-5.14-28");

    foreach (IPAddress addr in Enumerate(range))
    {
        Console.WriteLine(addr);
    }
}

static byte[,] ParseRange(string str)
{
    if (string.IsNullOrEmpty(str)) throw new ArgumentException("str");

    string[] partStr = str.Split('.');
    if (partStr.Length != 4) throw new FormatException();

    byte[,] range = new byte[4, 2];
    for (int i = 0; i < 4; i++)
    {
        string[] rangeStr = partStr[i].Split('-');
        if (rangeStr.Length > 2) throw new FormatException();

        range[i, 0] = byte.Parse(rangeStr[0]);
        range[i, 1] = byte.Parse(rangeStr[Math.Min(rangeStr.Length - 1, 1)]);

        // Remove this to allow ranges to wrap around.
        // For example: 254-4 = 254, 255, 0, 1, 2, 3, 4
        if (range[i, 1] < range[i, 0]) throw new FormatException();
    }

    return range;
}

static IEnumerable<IPAddress> Enumerate(byte[,] range)
{
    if (range.GetLength(0) != 4) throw new ArgumentException("range");
    if (range.GetLength(1) != 2) throw new ArgumentException("range");

    for (byte a = range[0, 0]; a != (byte)(range[0, 1] + 1); a++)
    {
        for (byte b = range[1, 0]; b != (byte)(range[1, 1] + 1); b++)
        {
            for (byte c = range[2, 0]; c != (byte)(range[2, 1] + 1); c++)
            {
                for (byte d = range[3, 0]; d != (byte)(range[3, 1] + 1); d++)
                {
                    yield return new IPAddress(new byte[] { a, b, c, d });
                }
            }
        }
    }
}