done

Netch/3rd/DnsClient.NET/Protocol/PtrRecord.cs

@@ -0,0 +1,57 @@
+using System;
+
+namespace DnsClient.Protocol
+{
+    /* RFC 1035 (https://tools.ietf.org/html/rfc1035#section-3.3.12)
+    3.3.12. PTR RDATA format
+
+        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+        /                   PTRDNAME                    /
+        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+
+    where:
+
+    PTRDNAME        A <domain-name> which points to some location in the
+                domain name space.
+
+    PTR records cause no additional section processing.  These RRs are used
+    in special domains to point to some other location in the domain space.
+    These records are simple data, and don't imply any special processing
+    similar to that performed by CNAME, which identifies aliases.  See the
+    description of the IN-ADDR.ARPA domain for an example.
+    */
+
+    /// <summary>
+    /// A <see cref="DnsResourceRecord"/> represending a pointer. These RRs are used
+    /// in special domains to point to some other location in the domain space.
+    /// </summary>
+    /// <seealso cref="DnsClient.Protocol.DnsResourceRecord" />
+    /// <seealso href="https://tools.ietf.org/html/rfc1035#section-3.3.12">RFC 1035</seealso>
+    public class PtrRecord : DnsResourceRecord
+    {
+        /// <summary>
+        /// Gets the domain name which points to some location in the domain name space.
+        /// </summary>
+        /// <value>
+        /// The domain name.
+        /// </value>
+        public DnsString PtrDomainName { get; }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="PtrRecord"/> class.
+        /// </summary>
+        /// <param name="info">The information.</param>
+        /// <param name="ptrDomainName">The domain name.</param>
+        /// <exception cref="System.ArgumentNullException">If <paramref name="info"/> or <paramref name="ptrDomainName"/> is null.</exception>
+        public PtrRecord(ResourceRecordInfo info, DnsString ptrDomainName)
+            : base(info)
+        {
+            PtrDomainName = ptrDomainName ?? throw new ArgumentNullException(nameof(ptrDomainName));
+        }
+
+        private protected override string RecordToString()
+        {
+            return PtrDomainName.Value;
+        }
+    }
+}