From d18a480dd203cfecb51c01e093f7adce79cc84da Mon Sep 17 00:00:00 2001
From: Shreyas Zare <shreyas@technitium.com>
Date: Sat, 12 Dec 2020 16:40:54 +0530
Subject: [PATCH] DomainTree: throwing InvalidDomainNameException instead of
 DnsServerException to allow returning format error response.

---
 DnsServerCore/Dns/Zones/DomainTree.cs         | 14 +++---
 .../Dns/Zones/InvalidDomainNameException.cs   | 46 +++++++++++++++++++
 2 files changed, 53 insertions(+), 7 deletions(-)
 create mode 100644 DnsServerCore/Dns/Zones/InvalidDomainNameException.cs

diff --git a/DnsServerCore/Dns/Zones/DomainTree.cs b/DnsServerCore/Dns/Zones/DomainTree.cs
index e909f25e..a1b48a45 100644
--- a/DnsServerCore/Dns/Zones/DomainTree.cs
+++ b/DnsServerCore/Dns/Zones/DomainTree.cs
@@ -97,7 +97,7 @@ namespace DnsServerCore.Dns.Zones
                 return Array.Empty<byte>();
 
             if (domain.Length > 255)
-                throw new DnsServerException("Invalid domain name [" + domain + "]: length cannot exceed 255 bytes.");
+                throw new InvalidDomainNameException("Invalid domain name [" + domain + "]: length cannot exceed 255 bytes.");
 
             byte[] key = new byte[domain.Length + 1];
             int keyOffset = 0;
@@ -117,16 +117,16 @@ namespace DnsServerCore.Dns.Zones
                 labelLength = labelEnd - labelStart;
 
                 if (labelLength == 0)
-                    throw new DnsServerException("Invalid domain name [" + domain + "]: label length cannot be 0 byte.");
+                    throw new InvalidDomainNameException("Invalid domain name [" + domain + "]: label length cannot be 0 byte.");
 
                 if (labelLength > 63)
-                    throw new DnsServerException("Invalid domain name [" + domain + "]: label length cannot exceed 63 bytes.");
+                    throw new InvalidDomainNameException("Invalid domain name [" + domain + "]: label length cannot exceed 63 bytes.");
 
                 if (domain[labelStart + 1] == '-')
-                    throw new DnsServerException("Invalid domain name [" + domain + "]: label cannot start with hyphen.");
+                    throw new InvalidDomainNameException("Invalid domain name [" + domain + "]: label cannot start with hyphen.");
 
                 if (domain[labelEnd] == '-')
-                    throw new DnsServerException("Invalid domain name [" + domain + "]: label cannot end with hyphen.");
+                    throw new InvalidDomainNameException("Invalid domain name [" + domain + "]: label cannot end with hyphen.");
 
                 if ((labelLength == 1) && (domain[labelStart + 1] == '*'))
                 {
@@ -138,11 +138,11 @@ namespace DnsServerCore.Dns.Zones
                     {
                         labelChar = domain[i];
                         if (labelChar >= _keyMap.Length)
-                            throw new DnsServerException("Invalid domain name [" + domain + "]: invalid character [" + labelChar + "] was found.");
+                            throw new InvalidDomainNameException("Invalid domain name [" + domain + "]: invalid character [" + labelChar + "] was found.");
 
                         labelKeyCode = _keyMap[labelChar];
                         if (labelKeyCode == 0xff)
-                            throw new DnsServerException("Invalid domain name [" + domain + "]: invalid character [" + labelChar + "] was found.");
+                            throw new InvalidDomainNameException("Invalid domain name [" + domain + "]: invalid character [" + labelChar + "] was found.");
 
                         key[keyOffset++] = labelKeyCode;
                     }
diff --git a/DnsServerCore/Dns/Zones/InvalidDomainNameException.cs b/DnsServerCore/Dns/Zones/InvalidDomainNameException.cs
new file mode 100644
index 00000000..64f17c10
--- /dev/null
+++ b/DnsServerCore/Dns/Zones/InvalidDomainNameException.cs
@@ -0,0 +1,46 @@
+/*
+Technitium DNS Server
+Copyright (C) 2020  Shreyas Zare (shreyas@technitium.com)
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+using System;
+
+namespace DnsServerCore.Dns.Zones
+{
+    public class InvalidDomainNameException : DnsServerException
+    {
+        #region constructors
+
+        public InvalidDomainNameException()
+            : base()
+        { }
+
+        public InvalidDomainNameException(string message)
+            : base(message)
+        { }
+
+        public InvalidDomainNameException(string message, Exception innerException)
+            : base(message, innerException)
+        { }
+
+        protected InvalidDomainNameException(System.Runtime.Serialization.SerializationInfo info, System.Runtime.Serialization.StreamingContext context)
+            : base(info, context)
+        { }
+
+        #endregion
+    }
+}