From e84b4a3748e4a0feeafeb53d60f68303217f034c Mon Sep 17 00:00:00 2001
From: Shreyas Zare <shreyas@technitium.com>
Date: Sat, 14 Nov 2020 16:44:28 +0530
Subject: [PATCH] VendorSpecificInformationOption: added hex string parsing.

---
 .../VendorSpecificInformationOption.cs        | 55 ++++++++++++++++++-
 1 file changed, 54 insertions(+), 1 deletion(-)

diff --git a/DnsServerCore/Dhcp/Options/VendorSpecificInformationOption.cs b/DnsServerCore/Dhcp/Options/VendorSpecificInformationOption.cs
index a0ca2280..9280da42 100644
--- a/DnsServerCore/Dhcp/Options/VendorSpecificInformationOption.cs
+++ b/DnsServerCore/Dhcp/Options/VendorSpecificInformationOption.cs
@@ -17,12 +17,14 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 */
 
+using System;
+using System.Globalization;
 using System.IO;
 using TechnitiumLibrary.IO;
 
 namespace DnsServerCore.Dhcp.Options
 {
-    class VendorSpecificInformationOption : DhcpOption
+    public class VendorSpecificInformationOption : DhcpOption
     {
         #region variables
 
@@ -32,6 +34,12 @@ namespace DnsServerCore.Dhcp.Options
 
         #region constructor
 
+        public VendorSpecificInformationOption(string hexInfo)
+            : base(DhcpOptionCode.VendorSpecificInformation)
+        {
+            _information = ParseHexString(hexInfo);
+        }
+
         public VendorSpecificInformationOption(byte[] information)
             : base(DhcpOptionCode.VendorSpecificInformation)
         {
@@ -44,6 +52,42 @@ namespace DnsServerCore.Dhcp.Options
 
         #endregion
 
+        #region private
+
+        private static byte[] ParseHexString(string value)
+        {
+            int i;
+            int j = -1;
+            string strHex;
+            int b;
+
+            using (MemoryStream mS = new MemoryStream())
+            {
+                while (true)
+                {
+                    i = value.IndexOf(':', j + 1);
+                    if (i < 0)
+                        i = value.Length;
+
+                    strHex = value.Substring(j + 1, i - j - 1);
+
+                    if (!int.TryParse(strHex, NumberStyles.HexNumber, CultureInfo.InvariantCulture, out b) || (b < byte.MinValue) || (b > byte.MaxValue))
+                        throw new InvalidDataException("VendorSpecificInformation option data must be a colon (:) separated hex string.");
+
+                    mS.WriteByte((byte)b);
+
+                    if (i == value.Length)
+                        break;
+
+                    j = i;
+                }
+
+                return mS.ToArray();
+            }
+        }
+
+        #endregion
+
         #region protected
 
         protected override void ParseOptionValue(Stream s)
@@ -58,6 +102,15 @@ namespace DnsServerCore.Dhcp.Options
 
         #endregion
 
+        #region public
+
+        public override string ToString()
+        {
+            return BitConverter.ToString(_information).Replace("-", ":");
+        }
+
+        #endregion
+
         #region properties
 
         public byte[] Information