done

2026-04-23 21:29:49 +08:00 · 2019-12-02 19:51:12 +08:00
commit b2ea730984
229 changed files with 86605 additions and 0 deletions
--- a/Netch/3rd/DnsClient.NET/Protocol/MXRecord.cs
+++ b/Netch/3rd/DnsClient.NET/Protocol/MXRecord.cs
@@ -0,0 +1,67 @@
+using System;
+
+namespace DnsClient.Protocol
+{
+    /* https://tools.ietf.org/html/rfc1035#section-3.3.9
+    3.3.9. MX RDATA format
+
+        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+        |                  PREFERENCE                   |
+        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+        /                   EXCHANGE                    /
+        /                                               /
+        +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+
+    where:
+
+    PREFERENCE      A 16 bit integer which specifies the preference given to
+                    this RR among others at the same owner.  Lower values
+                    are preferred.
+
+    EXCHANGE        A <domain-name> which specifies a host willing to act as
+                    a mail exchange for the owner name.
+
+    MX records cause type A additional section processing for the host
+    specified by EXCHANGE.  The use of MX RRs is explained in detail in
+    [RFC-974].
+    */
+
+    /// <summary>
+    /// A <see cref="DnsResourceRecord"/> represending a mail exchange.
+    /// </summary>
+    /// <seealso href="https://tools.ietf.org/html/rfc1035#section-3.3.9">RFC 1035</seealso>
+    /// <seealso href="https://tools.ietf.org/html/rfc974">RFC 974</seealso>
+    public class MxRecord : DnsResourceRecord
+    {
+        /// <summary>
+        /// Gets a 16 bit integer which specifies the preference given to
+        /// this RR among others at the same owner.
+        /// Lower values are preferred.
+        /// </summary>
+        public ushort Preference { get; }
+
+        /// <summary>
+        /// A domain name which specifies a host willing to act as a mail exchange.
+        /// </summary>
+        public DnsString Exchange { get; }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="MxRecord"/> class.
+        /// </summary>
+        /// <param name="info">The information.</param>
+        /// <param name="preference">The preference.</param>
+        /// <param name="domainName">Name of the domain.</param>
+        /// <exception cref="System.ArgumentNullException">If <paramref name="domainName"/> or <paramref name="info"/> is null.</exception>
+        public MxRecord(ResourceRecordInfo info, ushort preference, DnsString domainName)
+            : base(info)
+        {
+            Preference = preference;
+            Exchange = domainName ?? throw new ArgumentNullException(nameof(domainName));
+        }
+
+        private protected override string RecordToString()
+        {
+            return string.Format("{0} {1}", Preference, Exchange);
+        }
+    }
+}