done

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

@@ -0,0 +1,62 @@
+using System;
+
+namespace DnsClient.Protocol
+{
+    /*
+    https://tools.ietf.org/html/rfc1035#section-3.3.11:
+    NS RDATA format
+
+        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+        /                   NSDNAME                     /
+        /                                               /
+        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+
+    where:
+
+    NSDNAME         A <domain-name> which specifies a host which should be
+                authoritative for the specified class and domain.
+
+    NS records cause both the usual additional section processing to locate
+    a type A record, and, when used in a referral, a special search of the
+    zone in which they reside for glue information.
+
+    The NS RR states that the named host should be expected to have a zone
+    starting at owner name of the specified class.  Note that the class may
+    not indicate the protocol family which should be used to communicate
+    with the host, although it is typically a strong hint.  For example,
+    hosts which are name servers for either Internet (IN) or Hesiod (HS)
+    class information are normally queried using IN class protocols.
+     */
+
+    /// <summary>
+    /// A <see cref="DnsResourceRecord"/> represending an authoritative name server.
+    /// </summary>
+    /// <seealso href="https://tools.ietf.org/html/rfc1035#section-3.3.11">RFC 1035</seealso>
+    public class NsRecord : DnsResourceRecord
+    {
+        /// <summary>
+        /// Gets the domain name which specifies a host which should be authoritative for the specified class and domain.
+        /// </summary>
+        /// <value>
+        /// The domain name.
+        /// </value>
+        public DnsString NSDName { get; }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="NsRecord"/> class.
+        /// </summary>
+        /// <param name="info">The information.</param>
+        /// <param name="name">The name.</param>
+        /// <exception cref="System.ArgumentNullException">If <paramref name="name"/> or <paramref name="info"/> is null.</exception>
+        public NsRecord(ResourceRecordInfo info, DnsString name)
+            : base(info)
+        {
+            NSDName = name ?? throw new ArgumentNullException(nameof(name));
+        }
+
+        private protected override string RecordToString()
+        {
+            return NSDName.Value;
+        }
+    }
+}