Implement Record HashCode and Wire Writing

SmartHomeOS · Aug 14, 2024 · ac6d2ea · ac6d2ea
1 parent b1ada88
commit ac6d2ea
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Showing 10 changed files with 181 additions and 9 deletions.
diff --git a/TinyDNS/Records/AAAARecord.cs b/TinyDNS/Records/AAAARecord.cs
@@ -38,6 +38,15 @@ public AAAARecord(ResourceRecordHeader header, string rdata) : base(header)
             Address = IPAddress.Parse(rdata);
         }
 
+        public override void Write(Span<byte> buffer, ref int pos)
+        {
+            base.Write(buffer, ref pos);
+            BinaryPrimitives.WriteUInt16BigEndian(buffer.Slice(pos, 2), 16);
+            pos += 2;
+            Address.TryWriteBytes(buffer.Slice(pos, 16), out _);
+            pos += 16;
+        }
+
         public override bool Equals(ResourceRecord? other)
         {
             if (other is AAAARecord otherAAAA)
@@ -47,7 +56,9 @@ public override bool Equals(ResourceRecord? other)
 
         public override int GetHashCode()
         {
-            return Address.GetHashCode() + (int)Type;
+            HashCode hc = GetBaseHash();
+            hc.Add(Address);
+            return hc.ToHashCode();
         }
 
         public override string ToString()

diff --git a/TinyDNS/Records/ARecord.cs b/TinyDNS/Records/ARecord.cs
@@ -38,6 +38,15 @@ public ARecord(ResourceRecordHeader header, string rdata) : base(header)
             Address = IPAddress.Parse(rdata);
         }
 
+        public override void Write(Span<byte> buffer, ref int pos)
+        {
+            base.Write(buffer, ref pos);
+            BinaryPrimitives.WriteUInt16BigEndian(buffer.Slice(pos, 2), 4);
+            pos += 2;
+            Address.TryWriteBytes(buffer.Slice(pos, 4), out _);
+            pos += 4;
+        }
+
         public override bool Equals(ResourceRecord? other)
         {
             if (other is ARecord otherA)
@@ -47,7 +56,9 @@ public override bool Equals(ResourceRecord? other)
 
         public override int GetHashCode()
         {
-            return Address.GetHashCode() + (int)Type;
+            HashCode hc = GetBaseHash();
+            hc.Add(Address);
+            return hc.ToHashCode();
         }
 
         public override string ToString()

diff --git a/TinyDNS/Records/CNameRecord.cs b/TinyDNS/Records/CNameRecord.cs
@@ -10,6 +10,8 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+using System.Buffers.Binary;
+using System.Net;
 using TinyDNS.Enums;
 
 namespace TinyDNS.Records
@@ -35,13 +37,30 @@ public CNameRecord(ResourceRecordHeader header, string rdata) : base(header)
             CNameLabels = DomainParser.Parse(rdata);
         }
 
+        public override void Write(Span<byte> buffer, ref int pos)
+        {
+            base.Write(buffer, ref pos);
+            pos += 2;
+            int start = pos;
+            DomainParser.Write(CNameLabels, buffer, ref pos);
+            BinaryPrimitives.WriteUInt16BigEndian(buffer.Slice(start - 2, 2), (ushort)(pos- start));
+        }
+
         public override bool Equals(ResourceRecord? other)
         {
             if (other is CNameRecord otherCName)
                 return base.Equals(other) && CNameLabels.SequenceEqual(otherCName.CNameLabels);
             return false;
         }
 
+        public override int GetHashCode()
+        {
+            HashCode hc = GetBaseHash();
+            foreach (string label in CNameLabels)
+                hc.Add(label);
+            return hc.ToHashCode();
+        }
+
         public override string ToString()
         {
             return base.ToString() + $"\t{CName}";

diff --git a/TinyDNS/Records/DNameRecord.cs b/TinyDNS/Records/DNameRecord.cs
@@ -10,6 +10,8 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+using System.Buffers.Binary;
+using System.Net;
 using TinyDNS.Enums;
 
 namespace TinyDNS.Records
@@ -35,13 +37,30 @@ public DNameRecord(ResourceRecordHeader header, string rdata) : base(header)
             DNameLabels = DomainParser.Parse(rdata);
         }
 
+        public override void Write(Span<byte> buffer, ref int pos)
+        {
+            base.Write(buffer, ref pos);
+            pos += 2;
+            int start = pos;
+            DomainParser.Write(DNameLabels, buffer, ref pos);
+            BinaryPrimitives.WriteUInt16BigEndian(buffer.Slice(start - 2, 2), (ushort)(pos- start));
+        }
+
         public override bool Equals(ResourceRecord? other)
         {
             if (other is DNameRecord otherDName)
                 return base.Equals(other) && DNameLabels.SequenceEqual(otherDName.DNameLabels);
             return false;
         }
 
+        public override int GetHashCode()
+        {
+            HashCode hc = GetBaseHash();
+            foreach (string label in DNameLabels)
+                hc.Add(label);
+            return hc.ToHashCode();
+        }
+
         public override string ToString()
         {
             return base.ToString() + $"\t{DName}";

diff --git a/TinyDNS/Records/PtrRecord.cs b/TinyDNS/Records/PtrRecord.cs
@@ -10,6 +10,8 @@
 // You should have received a copy of the GNU Affero General Public License
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+using System.Buffers.Binary;
+using System.Net;
 using TinyDNS.Enums;
 
 namespace TinyDNS.Records
@@ -35,13 +37,31 @@ public PtrRecord(ResourceRecordHeader header, string rdata) : base(header)
             DomainLabels = DomainParser.Parse(rdata);
         }
 
+        public override void Write(Span<byte> buffer, ref int pos)
+        {
+            base.Write(buffer, ref pos);
+            pos += 2;
+            int start = pos;
+            DomainParser.Write(DomainLabels, buffer, ref pos);
+            BinaryPrimitives.WriteUInt16BigEndian(buffer.Slice(start - 2, 2), (ushort)(pos- start));
+        }
+
         public override bool Equals(ResourceRecord? other)
         {
             if (other is PtrRecord otherPtr)
                 return base.Equals(other) && DomainLabels.SequenceEqual(otherPtr.DomainLabels);
             return false;
         }
 
+        public override int GetHashCode()
+        {
+            HashCode hc = GetBaseHash();
+            foreach (var label in DomainLabels)
+                hc.Add(label);
+            int code = hc.ToHashCode();
+            return code;
+        }
+
         public override string ToString()
         {
             return base.ToString() + $"\t{Domain}";

diff --git a/TinyDNS/Records/ResourceRecord.cs b/TinyDNS/Records/ResourceRecord.cs
@@ -19,6 +19,7 @@ public class ResourceRecord : IEquatable<ResourceRecord>
         public DNSClass Class { get { return header.Class; } set { header.Class = value; } }
         public DNSRecordType Type { get { return header.Type; } set { header.Type = value; } }
         public List<string> Labels { get { return header.Labels; } set { header.Labels = value; } }
+        public DateTime Created { get { return header.Created; } set { header.Created = value; } }
         public DateTime Expires { get { return header.Expires; } set { header.Expires = value; } }
         public bool CacheFlush { get { return header.CacheFlush; } set { header.CacheFlush = value; } }
         public string Name { get { return string.Join('.', header.Labels); } }
@@ -78,14 +79,37 @@ public static ResourceRecord Parse(Span<byte> buffer, ref int pos)
             return record;
         }
 
-        public void Write(Span<byte> buffer, ref int pos)
+        public virtual void Write(Span<byte> buffer, ref int pos)
         {
             header.Write(buffer, ref pos);
         }
 
+        public override bool Equals(object? obj)
+        {
+            if (obj is ResourceRecord record)
+                return Equals(record);
+            return false;
+        }
+
         public virtual bool Equals(ResourceRecord? other)
         {
-            return Type == other!.Type && Name.SequenceEqual(other!.Name);
+            if (other == null)
+                return false;
+            return Type == other!.Type && Labels.SequenceEqual(other!.Labels);
+        }
+
+        protected HashCode GetBaseHash()
+        {
+            HashCode hc = new HashCode();
+            hc.Add(Type);
+            foreach (var label in Labels)
+                hc.Add(label);
+            return hc;
+        }
+
+        public override int GetHashCode()
+        {
+            return GetBaseHash().ToHashCode();
         }
 
         internal static ResourceRecord Parse(string line)

diff --git a/TinyDNS/Records/ResourceRecordHeader.cs b/TinyDNS/Records/ResourceRecordHeader.cs
@@ -21,6 +21,7 @@ public class ResourceRecordHeader
         public DNSRecordType Type { get; set; }
         public List<string> Labels { get; set; }
         public DateTime Expires { get; set; }
+        public DateTime Created { get; set; }
         public bool CacheFlush { get; set; }
 
         public ResourceRecordHeader(Span<byte> buffer, ref int pos)
@@ -32,7 +33,8 @@ public ResourceRecordHeader(Span<byte> buffer, ref int pos)
             pos += 2;
             CacheFlush = (recordClass & 0x8000) == 0x8000;
             Class = (DNSClass)(recordClass & 0x7FFF);
-            Expires = DateTime.Now + TimeSpan.FromSeconds(BinaryPrimitives.ReadUInt32BigEndian(buffer.Slice(pos, 4)));
+            Created = DateTime.Now;
+            Expires = Created + TimeSpan.FromSeconds(BinaryPrimitives.ReadUInt32BigEndian(buffer.Slice(pos, 4)));
             pos += 4;
         }
 
@@ -42,15 +44,17 @@ public ResourceRecordHeader(string[] columns)
             Type = DNSRecordParser.Parse(columns[2]);
             uint ttl = uint.Parse(columns[1]);
             Class = DNSClass.IN;
-            Expires = DateTime.Now + TimeSpan.FromSeconds(ttl);
+            Created = DateTime.Now;
+            Expires = Created + TimeSpan.FromSeconds(ttl);
         }
 
         public ResourceRecordHeader(List<string> labels, DNSRecordType type, DNSClass @class, uint ttl)
         {
             this.Labels = labels;
             this.Type = type;
             this.Class = @class;
-            this.Expires = DateTime.Now + TimeSpan.FromSeconds(ttl);
+            Created = DateTime.Now;
+            Expires = Created + TimeSpan.FromSeconds(ttl);
         }
 
         public void Write(Span<byte> buffer, ref int pos)
@@ -62,6 +66,10 @@ public void Write(Span<byte> buffer, ref int pos)
             if (CacheFlush)
                 ClassVal |= 0x8000;
             BinaryPrimitives.WriteUInt16BigEndian(buffer.Slice(pos, 2), ClassVal);
+            pos += 2;
+            uint ttl = (uint)(Expires - DateTime.Now).TotalSeconds;
+            BinaryPrimitives.WriteUInt32BigEndian(buffer.Slice(pos, 4), ttl);
+            pos += 4;
         }
     }
 }
diff --git a/TinyDNS/Records/SRVRecord.cs b/TinyDNS/Records/SRVRecord.cs
@@ -11,6 +11,7 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 using System.Buffers.Binary;
+using System.Net;
 using TinyDNS.Enums;
 
 namespace TinyDNS.Records
@@ -43,13 +44,40 @@ public SRVRecord(string service, ushort priority, ushort port, ushort weight, Li
             Weight = weight;
         }
 
+        public override void Write(Span<byte> buffer, ref int pos)
+        {
+            base.Write(buffer, ref pos);
+            //Length
+            pos += 2;
+            int start = pos;
+            BinaryPrimitives.WriteUInt16BigEndian(buffer.Slice(pos, 2), Priority);
+            pos += 2;
+            BinaryPrimitives.WriteUInt16BigEndian(buffer.Slice(pos, 2), Weight);
+            pos += 2;
+            BinaryPrimitives.WriteUInt16BigEndian(buffer.Slice(pos, 2), Port);
+            pos += 2;
+            DomainParser.Write(TargetLabels, buffer, ref pos);
+            BinaryPrimitives.WriteUInt16BigEndian(buffer.Slice(start - 2, 2), (ushort)(pos- start));
+        }
+
         public override bool Equals(ResourceRecord? other)
         {
             if (other is SRVRecord otherSrv)
-                return base.Equals(other) && Port == otherSrv.Port && TargetLabels.Equals(otherSrv.TargetLabels);
+                return base.Equals(other) && Port == otherSrv.Port && TargetLabels.SequenceEqual(otherSrv.TargetLabels);
             return false;
         }
 
+        public override int GetHashCode()
+        {
+            HashCode hc = GetBaseHash();
+            hc.Add(Port);
+            hc.Add(Priority);
+            hc.Add(Weight);
+            foreach (string label in TargetLabels)
+                hc.Add(label);
+            return hc.ToHashCode();
+        }
+
         public override string ToString()
         {
             return base.ToString() + $"\t{Priority}\t{Weight}\t{Port}\t{Target}";

diff --git a/TinyDNS/Records/TxtRecord.cs b/TinyDNS/Records/TxtRecord.cs
@@ -11,6 +11,7 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 using System.Buffers.Binary;
+using System.Net;
 using System.Text;
 using TinyDNS.Enums;
 
@@ -46,13 +47,27 @@ public TxtRecord(List<string> strings, List<string> labels, DNSClass @class, uin
             Strings = strings;
         }
 
+        public override void Write(Span<byte> buffer, ref int pos)
+        {
+            base.Write(buffer, ref pos);
+            //TODO
+        }
+
         public override bool Equals(ResourceRecord? other)
         {
             if (other is TxtRecord otherTxt)
-                return base.Equals(other) && Strings.Equals(otherTxt.Strings);
+                return base.Equals(other) && Strings.SequenceEqual(otherTxt.Strings);
             return false;
         }
 
+        public override int GetHashCode()
+        {
+            HashCode hc = GetBaseHash();
+            foreach (string txtString in Strings)
+                hc.Add(txtString);
+            return hc.ToHashCode();
+        }
+
         public override string ToString()
         {
             return base.ToString() + $"\t{string.Join(',', Strings)}";

diff --git a/TinyDNS/Records/UnsupportedRecord.cs b/TinyDNS/Records/UnsupportedRecord.cs
@@ -11,6 +11,7 @@
 // along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 using System.Buffers.Binary;
+using System.Net;
 using System.Text;
 using TinyDNS.Enums;
 
@@ -42,13 +43,29 @@ public UnsupportedRecord(ResourceRecordHeader header, string rdata) : base(heade
             RData = Encoding.UTF8.GetBytes(rdata);
         }
 
+        public override void Write(Span<byte> buffer, ref int pos)
+        {
+            base.Write(buffer, ref pos);
+            BinaryPrimitives.WriteUInt16BigEndian(buffer.Slice(pos, 2), (ushort)RData.Length);
+            pos += 2;
+            RData.CopyTo(buffer.Slice(pos, RData.Length));
+            pos += RData.Length;
+        }
+
         public override bool Equals(ResourceRecord? other)
         {
             if (other is UnsupportedRecord unsupported)
                 return base.Equals(other) && RData.Equals(unsupported.RData);
             return false;
         }
 
+        public override int GetHashCode()
+        {
+            HashCode hc = GetBaseHash();
+            hc.Add(RData);
+            return hc.ToHashCode();
+        }
+
         public override string ToString()
         {
             return base.ToString() + $"\t{RData.Length} Bytes";